1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 13
6 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
7 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
10 * GDB now has some support for integer types larger than 64 bits.
12 * Removed targets and native configurations
14 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
15 AIX version is now AIX 7.1.
17 * Multi-target feature configuration
19 GDB now supports the individual configuration of remote targets' feature
20 sets. Based on the current selection of a target, the commands 'set remote
21 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
22 configure a target's feature packet and to display its configuration,
25 The individual packet sizes can be configured and shown using the commands
26 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
27 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
28 ** 'show remote memory-read-packet-size'
29 ** 'show remote memory-write-packet-size'.
31 The configuration of the packet itself, as well as the size of a memory-read
32 or memory-write packet applies to the currently selected target (if
33 available). If no target is selected, it applies to future remote
34 connections. Similarly, the show commands print the configuration of the
35 currently selected target. If no remote target is selected, the default
36 configuration for future connections is shown.
38 * MI version 1 has been removed.
40 * GDB has initial built-in support for the Debugger Adapter Protocol.
41 This support requires that GDB be built with Python scripting
44 * For the break command, multiple uses of the 'thread' or 'task'
45 keywords will now give an error instead of just using the thread or
46 task id from the last instance of the keyword. E.g.:
47 break foo thread 1 thread 2
48 will now give an error rather than using 'thread 2'.
50 * For the watch command, multiple uses of the 'task' keyword will now
51 give an error instead of just using the task id from the last
52 instance of the keyword. E.g.:
53 watch my_var task 1 task 2
54 will now give an error rather than using 'task 2'. The 'thread'
55 keyword already gave an error when used multiple times with the
56 watch command, this remains unchanged.
58 * The 'set print elements' setting now helps when printing large arrays.
59 If an array would otherwise exceed max-value-size, but 'print elements'
60 is set such that the size of elements to print is less than or equal
61 to 'max-value-size', GDB will now still print the array, however only
62 'max-value-size' worth of data will be added into the value history.
64 * For both the break and watch commands, it is now invalid to use both
65 the 'thread' and 'task' keywords within the same command. For
66 example the following commnds will now give an error:
67 break foo thread 1 task 1
68 watch var thread 2 task 3
70 * The printf command now accepts a '%V' output format which will
71 format an expression just as the 'print' command would. Print
72 options can be placed withing '[...]' after the '%V' to modify how
73 the value is printed. E.g:
74 printf "%V", some_array
75 printf "%V[-array-indexes on]", some_array
76 will print the array without, or with array indexes included, just
77 as the array would be printed by the 'print' command. This
78 functionality is also available for dprintf when dprintf-style is
81 * When the printf command requires a string to be fetched from the
82 inferior, GDB now uses the existing 'max-value-size' setting to the
83 limit the memory allocated within GDB. The default 'max-value-size'
84 is 64k. To print longer strings you should increase
87 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
89 * The Ada 2022 target name symbol ('@') is now supported by the Ada
92 * The 'list' command now accepts '.' as an argument, which tells GDB to
93 print the location where the inferior is stopped. If the inferior hasn't
94 started yet, the command will print around the main function.
96 * Using the 'list' command with no arguments in a situation where the
97 command would attempt to list past the end of the file now warns the
98 user that the end of file has been reached, refers the user to the
99 newly added '.' argument
101 * Breakpoints can now be inferior-specific. This is similar to the
102 existing thread-specific breakpoint support. Breakpoint conditions
103 can include the 'inferior' keyword followed by an inferior id (as
104 displayed in the 'info inferiors' output). It is invalid to use the
105 'inferior' keyword with either the 'thread' or 'task' keywords when
106 creating a breakpoint.
110 set debug breakpoint on|off
111 show debug breakpoint
112 Print additional debug messages about breakpoint insertion and removal.
114 maintenance print record-instruction [ N ]
115 Print the recorded information for a given instruction. If N is not given
116 prints how GDB would undo the last instruction executed. If N is negative,
117 prints how GDB would undo the N-th previous instruction, and if N is
118 positive, it prints how GDB will redo the N-th following instruction.
120 maintenance info frame-unwinders
121 List the frame unwinders currently in effect, starting with the highest
124 maintenance wait-for-index-cache
125 Wait until all pending writes to the index cache have completed.
127 set always-read-ctf on|off
129 When off, CTF is only read if DWARF is not present. When on, CTF is
130 read regardless of whether DWARF is present. Off by default.
133 Get main symbol to identify entry point into program.
135 * New convenience function "$_shell", to execute a shell command and
136 return the result. This lets you run shell commands in expressions.
139 (gdb) p $_shell("true")
141 (gdb) p $_shell("false")
143 (gdb) break func if $_shell("some command") == 0
147 ** mi now reports 'no-history' as a stop reason when hitting the end of the
148 reverse execution history.
150 ** When creating a thread-specific breakpoint using the '-p' option,
151 the -break-insert command would report the 'thread' field twice in
152 the reply. The content of both fields was always identical. This
153 has now been fixed; the 'thread' field will be reported just once
154 for thread-specific breakpoints, or not at all for breakpoints
155 without a thread restriction. The same is also true for the 'task'
156 field of an Ada task-specific breakpoint.
158 ** It is no longer possible to create a thread-specific breakpoint for
159 a thread that doesn't exist using '-break-insert -p ID'. Creating
160 breakpoints for non-existent threads is not allowed when using the
161 CLI, that the MI allowed it was a long standing bug, which has now
164 ** The '--simple-values' argument to the '-stack-list-arguments',
165 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
166 commands now takes reference types into account: that is, a value is now
167 considered simple if it is neither an array, structure, or union, nor a
168 reference to an array, structure, or union. (Previously all references were
169 considered simple.) Support for this feature can be verified by using the
170 '-list-features' command, which should contain "simple-values-ref-types".
172 ** The -break-insert command now accepts a '-g thread-group-id' option
173 to allow for the creation of inferior-specific breakpoints.
175 ** The bkpt tuple, which appears in breakpoint-created notifications,
176 and in the result of the -break-insert command can now include an
177 optional 'inferior' field for both the main breakpoint, and each
178 location, when the breakpoint is inferior-specific.
182 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
184 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
186 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
187 now be of type 'str' otherwise a TypeError will be raised.
189 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
190 values of type 'bool'. Changing this attribute will now
191 invalidate GDB's frame-cache, which means GDB will need to
192 rebuild its frame-cache when next required - either with, or
193 without the particular unwinder, depending on how 'enabled' was
196 ** New methods added to the gdb.PendingFrame class. These methods
197 have the same behaviour as the corresponding methods on
198 gdb.Frame. The new methods are:
200 - gdb.PendingFrame.name: Return the name for the frame's
202 - gdb.PendingFrame.is_valid: Return True if the pending frame
204 - gdb.PendingFrame.pc: Return the $pc register value for this
206 - gdb.PendingFrame.language: Return a string containing the
207 language for this frame, or None.
208 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
209 object for the current location within the pending frame, or
211 - gdb.PendingFrame.block: Return a gdb.Block for the current
212 pending frame, or None.
213 - gdb.PendingFrame.function: Return a gdb.Symbol for the
214 current pending frame, or None.
216 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
217 now use either an integer or a gdb.Value object for each of its
218 'sp', 'pc', and 'special' attributes.
220 ** A new class gdb.unwinder.FrameId has been added. Instances of
221 this class are constructed with 'sp' (stack-pointer) and 'pc'
222 (program-counter) values, and can be used as the frame-id when
223 calling gdb.PendingFrame.create_unwind_info.
225 ** It is now no longer possible to sub-class the
226 gdb.disassembler.DisassemblerResult type.
228 ** The Disassembler API from the gdb.disassembler module has been
229 extended to include styling support:
231 - The DisassemblerResult class can now be initialized with a list
232 of parts. Each part represents part of the disassembled
233 instruction along with the associated style information. This
234 list of parts can be accessed with the new
235 DisassemblerResult.parts property.
237 - New constants gdb.disassembler.STYLE_* representing all the
238 different styles part of an instruction might have.
240 - New methods DisassembleInfo.text_part and
241 DisassembleInfo.address_part which are used to create the new
242 styled parts of a disassembled instruction.
244 - Changes are backwards compatible, the older API can still be
245 used to disassemble instructions without styling.
247 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
248 GDB/MI command and returns the output as a Python dictionary.
250 ** New function gdb.block_signals(). This returns a context manager
251 that blocks any signals that GDB needs to handle itself.
253 ** New class gdb.Thread. This is a subclass of threading.Thread
254 that calls gdb.block_signals in its "start" method.
256 ** gdb.parse_and_eval now has a new "global_context" parameter.
257 This can be used to request that the parse only examine global
260 ** gdb.Inferior now has a new "arguments" attribute. This holds the
261 command-line arguments to the inferior, if known.
263 ** gdb.Inferior now has a new "main_name" attribute. This holds the
264 name of the inferior's "main", if known.
266 ** gdb.Inferior now has new methods "clear_env", "set_env", and
267 "unset_env". These can be used to modify the inferior's
268 environment before it is started.
270 ** gdb.Value now has the 'assign' method.
272 ** gdb.Progspace now has the new method "objfile_for_address". This
273 returns the gdb.Objfile, if any, that covers a given address.
275 ** gdb.Breakpoint now has an "inferior" attribute. If the
276 Breakpoint object is inferior specific then this attribute holds
277 the inferior-id (an integer). If the Breakpoint object is not
278 inferior specific, then this field contains None. This field can
281 *** Changes in GDB 13
283 * MI version 1 is deprecated, and will be removed in GDB 14.
285 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
286 reading memory tag data for AArch64 MTE from core files generated by
287 the gcore command or the Linux kernel.
289 When a process uses memory-mapped pages protected by memory tags (for
290 example, AArch64 MTE), this additional information will be recorded in
291 the core file in the event of a crash or if GDB generates a core file
292 from the current process state. GDB will show this additional information
293 automatically, or through one of the memory-tag subcommands.
295 * "info breakpoints" now displays enabled breakpoint locations of
296 disabled breakpoints as in the "y-" state. For example:
298 (gdb) info breakpoints
299 Num Type Disp Enb Address What
300 1 breakpoint keep n <MULTIPLE>
301 1.1 y- 0x00000000000011b6 in ...
302 1.2 y- 0x00000000000011c2 in ...
303 1.3 n 0x00000000000011ce in ...
305 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
306 aarch64 architectures.
308 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
310 * Remove support for building against Python 2, it is now only possible to
311 build GDB against Python 3.
313 * DBX mode has been removed.
315 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
316 emit to indicate where a breakpoint should be placed to break in a function
319 * Completion now also offers "NUMBER" for "set" commands that accept
320 a numeric argument and the "unlimited" keyword. For example:
322 (gdb) set width <TAB>
327 (gdb) complete set width
331 * Disassembler styling using libopcodes. GDB now supports
332 disassembler styling using libopcodes. This is only available for
333 some targets (currently x86 and RISC-V). For unsupported targets
334 Python Pygments is still used. For supported targets, libopcodes
335 styling is used by default.
337 * The Windows native target now supports target async.
339 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
341 * The format of 'disassemble /r' and 'record instruction-history /r'
342 has changed. The instruction bytes could now be grouped together,
343 and displayed in the endianness of the instruction. This is the
344 same layout as used by GNU objdump when disassembling.
346 There is now 'disassemble /b' and 'record instruction-history /b'
347 which will always display the instructions bytes one at a time in
348 memory order, that is, the byte at the lowest address first.
350 For both /r and /b GDB is now better at using whitespace in order to
351 align the disassembled instruction text.
353 * The TUI no longer styles the source and assembly code highlighted by
354 the current position indicator by default. You can however
355 re-enable styling using the new "set style tui-current-position"
358 * New convenience variable $_inferior_thread_count contains the number
359 of live threads in the current inferior.
361 * When a breakpoint with multiple code locations is hit, GDB now prints
362 the code location using the syntax <breakpoint_number>.<location_number>
364 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
366 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
367 and $_hit_locno to the hit breakpoint number and code location number.
368 This allows to disable the last hit breakpoint using
369 (gdb) disable $_hit_bpnum
370 or disable only the specific breakpoint code location using
371 (gdb) disable $_hit_bpnum.$_hit_locno
372 These commands can be used inside the command list of a breakpoint to
373 automatically disable the just encountered breakpoint (or the just
374 encountered specific breakpoint code location).
375 When a breakpoint has only one location, $_hit_locno is set to 1 so that
376 (gdb) disable $_hit_bpnum.$_hit_locno
378 (gdb) disable $_hit_bpnum
379 are both disabling the breakpoint.
383 maintenance set ignore-prologue-end-flag on|off
384 maintenance show ignore-prologue-end-flag
385 This setting, which is off by default, controls whether GDB ignores the
386 PROLOGUE-END flag from the line-table when skipping prologue. This can be
387 used to force GDB to use prologue analyzers if the line-table is constructed
388 from erroneous debug information.
390 set print nibbles [on|off]
392 This controls whether the 'print/t' command will display binary values
393 in groups of four bits, known as "nibbles". The default is 'off'.
395 maintenance set libopcodes-styling on|off
396 maintenance show libopcodes-styling
397 These can be used to force off libopcodes based styling, the Python
398 Pygments styling will then be used instead.
400 set style disassembler comment
401 show style disassembler comment
402 set style disassembler immediate
403 show style disassembler immediate
404 set style disassembler mnemonic
405 show style disassembler mnemonic
406 set style disassembler register
407 show style disassembler register
408 set style disassembler address
409 show style disassembler address
410 set style disassembler symbol
411 show style disassembler symbol
412 For targets that support libopcodes based styling, these settings
413 control how various aspects of the disassembler output are styled.
414 The 'disassembler address' and 'disassembler symbol' styles are
415 aliases for the 'address' and 'function' styles respectively.
417 maintenance print frame-id [ LEVEL ]
418 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
419 not given, then print the frame-id for the currently selected frame.
421 set debug infcall on|off
423 Print additional debug messages about inferior function calls.
425 set debug solib on|off
427 Print additional debug messages about shared library handling.
429 set style tui-current-position [on|off]
430 Whether to style the source and assembly code highlighted by the
431 TUI's current position indicator. The default is off.
433 set print characters LIMIT
434 show print characters
435 This new setting is like 'set print elements', but controls how many
436 characters of a string are printed. This functionality used to be
437 covered by 'set print elements', but it can be controlled separately
438 now. LIMIT can be set to a numerical value to request that particular
439 character count, to 'unlimited' to print all characters of a string,
440 or to 'elements', which is also the default, to follow the setting of
441 'set print elements' as it used to be.
443 print -characters LIMIT
444 This new option to the 'print' command has the same effect as a temporary
445 use of 'set print characters'.
449 document user-defined
450 It is now possible to document user-defined aliases.
451 When a user-defined alias is documented, the help and apropos commands
452 use the provided documentation instead of the documentation of the
454 Documenting a user-defined alias is particularly useful when the alias
455 is a set of nested 'with' commands to avoid showing the help of
456 the with command for an alias that will in fact launch the
457 last command given in the nested commands.
459 maintenance info line-table
460 Add a PROLOGUE-END column to the output which indicates that an
461 entry corresponds to an address where a breakpoint should be placed
462 to be at the first instruction past a function's prologue.
466 set debug aix-solib on|off
468 set debug solib-frv on|off
470 Removed in favor of "set/show debug solib".
472 maintenance info program-spaces
473 This command now includes a 'Core File' column which indicates the
474 name of the core file associated with each program space.
478 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
480 GNU/Linux/CSKY (gdbserver) csky*-*linux*
486 ** The async record stating the stopped reason 'breakpoint-hit' now
487 contains an optional field locno giving the code location number
488 when the breakpoint has multiple code locations.
492 ** GDB will now reformat the doc string for gdb.Command and
493 gdb.Parameter sub-classes to remove unnecessary leading
494 whitespace from each line before using the string as the help
497 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
498 that formats ADDRESS as 'address <symbol+offset>', where symbol is
499 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
500 This is the same format that GDB uses when printing address, symbol,
501 and offset information from the disassembler.
503 ** New function gdb.current_language that returns the name of the
504 current language. Unlike gdb.parameter('language'), this will
507 ** New method gdb.Frame.language that returns the name of the
510 ** New Python API for wrapping GDB's disassembler:
512 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
513 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
514 ARCH is either None or a string containing a bfd architecture
515 name. DISASSEMBLER is registered as a disassembler for
516 architecture ARCH, or for all architectures if ARCH is None.
517 The previous disassembler registered for ARCH is returned, this
518 can be None if no previous disassembler was registered.
520 - gdb.disassembler.Disassembler is the class from which all
521 disassemblers should inherit. Its constructor takes a string,
522 a name for the disassembler, which is currently only used in
523 some debug output. Sub-classes should override the __call__
524 method to perform disassembly, invoking __call__ on this base
525 class will raise an exception.
527 - gdb.disassembler.DisassembleInfo is the class used to describe
528 a single disassembly request from GDB. An instance of this
529 class is passed to the __call__ method of
530 gdb.disassembler.Disassembler and has the following read-only
531 attributes: 'address', and 'architecture', as well as the
532 following method: 'read_memory'.
534 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
535 calls GDB's builtin disassembler on INFO, which is a
536 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
537 optional, its default value is None. If MEMORY_SOURCE is not
538 None then it must be an object that has a 'read_memory' method.
540 - gdb.disassembler.DisassemblerResult is a class that can be used
541 to wrap the result of a call to a Disassembler. It has
542 read-only attributes 'length' and 'string'.
544 ** gdb.Objfile now has an attribute named "is_file". This is True
545 if the objfile comes from a file, and False otherwise.
547 ** New function gdb.print_options that returns a dictionary of the
548 prevailing print options, in the form accepted by
549 gdb.Value.format_string.
551 ** gdb.Value.format_string now uses the format provided by 'print',
552 if it is called during a 'print' or other similar operation.
554 ** gdb.Value.format_string now accepts the 'summary' keyword. This
555 can be used to request a shorter representation of a value, the
556 way that 'set print frame-arguments scalars' does.
558 ** New Python type gdb.BreakpointLocation.
559 The new attribute 'locations' of gdb.Breakpoint returns a list of
560 gdb.BreakpointLocation objects specifying the locations where the
561 breakpoint is inserted into the debuggee.
563 ** The gdb.register_window_type method now restricts the set of
564 acceptable window names. The first character of a window's name
565 must start with a character in the set [a-zA-Z], every subsequent
566 character of a window's name must be in the set [-_.a-zA-Z0-9].
568 * New features in the GDB remote stub, GDBserver
570 ** GDBserver is now supported on LoongArch GNU/Linux.
572 ** GDBserver is now supported on CSKY GNU/Linux.
574 * LoongArch floating-point support
576 GDB now supports floating-point on LoongArch GNU/Linux.
578 * AMD GPU ROCm debugging support
580 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
583 *** Changes in GDB 12
585 * DBX mode is deprecated, and will be removed in GDB 13
587 * GDB 12 is the last release of GDB that will support building against
588 Python 2. From GDB 13, it will only be possible to build GDB itself
589 with Python 3 support.
591 * The disable-randomization setting now works on Windows.
593 * Improved C++ template support
595 GDB now treats functions/types involving C++ templates like it does function
596 overloads. Users may omit parameter lists to set breakpoints on families of
597 template functions, including types/functions composed of multiple template types:
599 (gdb) break template_func(template_1, int)
601 The above will set breakpoints at every function `template_func' where
602 the first function parameter is any template type named `template_1' and
603 the second function parameter is `int'.
605 TAB completion also gains similar improvements.
607 * The FreeBSD native target now supports async mode.
613 Enable or disable multithreaded symbol loading. This is enabled
614 by default, but passing --disable-threading or --enable-threading=no
615 to configure will disable it.
617 Disabling this can cause a performance penalty when there are a lot of
618 symbols to load, but is useful for debugging purposes.
622 maint set backtrace-on-fatal-signal on|off
623 maint show backtrace-on-fatal-signal
624 This setting is 'on' by default. When 'on' GDB will print a limited
625 backtrace to stderr in the situation where GDB terminates with a
626 fatal signal. This only supported on some platforms where the
627 backtrace and backtrace_symbols_fd functions are available.
629 set source open on|off
631 This setting, which is on by default, controls whether GDB will try
632 to open source code files. Switching this off will stop GDB trying
633 to open and read source code files, which can be useful if the files
634 are located over a slow network connection.
638 These are now deprecated aliases for "set max-value-size" and
639 "show max-value-size".
641 task apply [all | TASK-IDS...] [FLAG]... COMMAND
642 Like "thread apply", but applies COMMAND to Ada tasks.
645 Watchpoints can now be restricted to a specific Ada task.
647 maint set internal-error backtrace on|off
648 maint show internal-error backtrace
649 maint set internal-warning backtrace on|off
650 maint show internal-warning backtrace
651 GDB can now print a backtrace of itself when it encounters either an
652 internal-error, or an internal-warning. This is on by default for
653 internal-error and off by default for internal-warning.
656 Deprecated and replaced by "set logging enabled on|off".
658 set logging enabled on|off
660 These commands set or show whether logging is enabled or disabled.
663 You can now exit GDB by using the new command "exit", in addition to
664 the existing "quit" command.
666 set debug threads on|off
668 Print additional debug messages about thread creation and deletion.
670 set debug linux-nat on|off
672 These new commands replaced the old 'set debug lin-lwp' and 'show
673 debug lin-lwp' respectively. Turning this setting on prints debug
674 messages relating to GDB's handling of native Linux inferiors.
676 maint flush source-cache
677 Flush the contents of the source code cache.
679 maint set gnu-source-highlight enabled on|off
680 maint show gnu-source-highlight enabled
681 Whether GDB should use the GNU Source Highlight library for adding
682 styling to source code. When off, the library will not be used, even
683 when available. When GNU Source Highlight isn't used, or can't add
684 styling to a particular source file, then the Python Pygments
685 library will be used instead.
687 set suppress-cli-notifications (on|off)
688 show suppress-cli-notifications
689 This controls whether printing the notifications is suppressed for CLI.
690 CLI notifications occur when you change the selected context
691 (i.e., the current inferior, thread and/or the frame), or when
692 the program being debugged stops (e.g., because of hitting a
693 breakpoint, completing source-stepping, an interrupt, etc.).
695 set style disassembler enabled on|off
696 show style disassembler enabled
697 If GDB is compiled with Python support, and the Python Pygments
698 package is available, then, when this setting is on, disassembler
699 output will have styling applied.
701 set ada source-charset
702 show ada source-charset
703 Set the character set encoding that is assumed for Ada symbols. Valid
704 values for this follow the values that can be passed to the GNAT
705 compiler via the '-gnati' option. The default is ISO-8859-1.
711 These are the new names for the old 'layout', 'focus', 'refresh',
712 and 'winheight' tui commands respectively. The old names still
713 exist as aliases to these new commands.
717 The new command 'tui window width', and the alias 'winwidth' allow
718 the width of a tui window to be adjusted when windows are laid out
723 Control the display of debug output about GDB's tui.
728 Printing of floating-point values with base-modifying formats like
729 /x has been changed to display the underlying bytes of the value in
730 the desired base. This was GDB's documented behavior, but was never
731 implemented correctly.
734 This command can now print a reply, if the reply includes
735 non-printable characters. Any non-printable characters are printed
736 as escaped hex, e.g. \x?? where '??' is replaces with the value of
737 the non-printable character.
740 The clone-inferior command now ensures that the TTY, CMD and ARGS
741 settings are copied from the original inferior to the new one.
742 All modifications to the environment variables done using the 'set
743 environment' or 'unset environment' commands are also copied to the new
746 set debug lin-lwp on|off
748 These commands have been removed from GDB. The new command 'set
749 debug linux-nat' and 'show debug linux-nat' should be used
753 This command now includes information about the width of the tui
754 windows in its output.
760 These commands are now aliases for the 'tui layout', 'tui focus',
761 'tui refresh', and 'tui window height' commands respectively.
763 * GDB's Ada parser now supports an extension for specifying the exact
764 byte contents of a floating-point literal. This can be useful for
765 setting floating-point registers to a precise value without loss of
766 precision. The syntax is an extension of the based literal syntax.
767 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
768 of the floating-point type, and the "f" is the marker for floating
773 ** The '-add-inferior' with no option flags now inherits the
774 connection of the current inferior, this restores the behaviour of
775 GDB as it was prior to GDB 10.
777 ** The '-add-inferior' command now accepts a '--no-connection'
778 option, which causes the new inferior to start without a
781 ** The default version of the MI interpreter is now 4 (-i=mi4).
783 ** The "script" field in breakpoint output (which is syntactically
784 incorrect in MI 3 and below) has changed in MI 4 to become a list.
785 This affects the following commands and events:
789 - =breakpoint-created
790 - =breakpoint-modified
792 The -fix-breakpoint-script-output command can be used to enable
793 this behavior with previous MI versions.
797 GNU/Linux/LoongArch loongarch*-*-linux*
805 ** New function gdb.add_history(), which takes a gdb.Value object
806 and adds the value it represents to GDB's history list. An
807 integer, the index of the new item in the history list, is
810 ** New function gdb.history_count(), which returns the number of
811 values in GDB's value history.
813 ** New gdb.events.gdb_exiting event. This event is called with a
814 gdb.GdbExitingEvent object which has the read-only attribute
815 'exit_code', which contains the value of the GDB exit code. This
816 event is triggered once GDB decides it is going to exit, but
817 before GDB starts to clean up its internal state.
819 ** New function gdb.architecture_names(), which returns a list
820 containing all of the possible Architecture.name() values. Each
823 ** New function gdb.Architecture.integer_type(), which returns an
824 integer type given a size and a signed-ness.
826 ** New gdb.TargetConnection object type that represents a connection
827 (as displayed by the 'info connections' command). A sub-class,
828 gdb.RemoteTargetConnection, is used to represent 'remote' and
829 'extended-remote' connections.
831 ** The gdb.Inferior type now has a 'connection' property which is an
832 instance of gdb.TargetConnection, the connection used by this
833 inferior. This can be None if the inferior has no connection.
835 ** New 'gdb.events.connection_removed' event registry, which emits a
836 'gdb.ConnectionEvent' when a connection is removed from GDB.
837 This event has a 'connection' property, a gdb.TargetConnection
838 object for the connection being removed.
840 ** New gdb.connections() function that returns a list of all
841 currently active connections.
843 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
844 is equivalent to the existing 'maint packet' CLI command; it
845 allows a user specified packet to be sent to the remote target.
847 ** New function gdb.host_charset(), returns a string, which is the
848 name of the current host charset.
850 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
853 ** New gdb.with_parameter(NAME, VALUE). This returns a context
854 manager that temporarily sets the gdb parameter NAME to VALUE,
855 then resets it when the context is exited.
857 ** The gdb.Value.format_string method now takes a 'styling'
858 argument, which is a boolean. When true, the returned string can
859 include escape sequences to apply styling. The styling will only
860 be present if styling is otherwise turned on in GDB (see 'help
861 set styling'). When false, which is the default if the argument
862 is not given, then no styling is applied to the returned string.
864 ** New read-only attribute gdb.InferiorThread.details, which is
865 either a string, containing additional, target specific thread
866 state information, or None, if there is no such additional
869 ** New read-only attribute gdb.Type.is_scalar, which is True for
870 scalar types, and False for all other types.
872 ** New read-only attribute gdb.Type.is_signed. This attribute
873 should only be read when Type.is_scalar is True, and will be True
874 for signed types, and False for all other types. Attempting to
875 read this attribute for non-scalar types will raise a ValueError.
877 ** It is now possible to add GDB/MI commands implemented in Python.
879 * New features in the GDB remote stub, GDBserver
881 ** GDBserver is now supported on OpenRISC GNU/Linux.
883 * New native configurations
885 GNU/Linux/OpenRISC or1k*-*-linux*
887 *** Changes in GDB 11
889 * The 'set disassembler-options' command now supports specifying options
892 * GDB now supports general memory tagging functionality if the underlying
893 architecture supports the proper primitives and hooks. Currently this is
894 enabled only for AArch64 MTE.
898 - Additional information when the inferior crashes with a SIGSEGV caused by
899 a memory tag violation.
901 - A new modifier 'm' for the "x" command, which displays allocation tags for a
902 particular memory range.
904 - Display of memory tag mismatches by "print", for addresses and
905 pointers, if memory tagging is supported by the architecture.
907 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
912 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
914 The MI -break-insert and -dprintf-insert commands now support a
915 new "--qualified" option that makes GDB interpret a specified
916 function name as a complete fully-qualified name. This is the
917 equivalent of the CLI's "break -qualified" and "dprintf
920 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
922 The MI -break-insert and -dprintf-insert commands now support a
923 '--force-condition' flag to forcibly define a condition even when
924 the condition is invalid at all locations of the breakpoint. This
925 is equivalent to the '-force-condition' flag of the CLI's "break"
928 ** '-break-condition --force'
930 The MI -break-condition command now supports a '--force' flag to
931 forcibly define a condition even when the condition is invalid at
932 all locations of the selected breakpoint. This is equivalent to
933 the '-force' flag of the CLI's "cond" command.
935 ** '-file-list-exec-source-files [--group-by-objfile]
936 [--basename | --dirname]
939 The existing -file-list-exec-source-files command now takes an
940 optional REGEXP which is used to filter the source files that are
941 included in the results.
943 By default REGEXP is matched against the full filename of the
944 source file. When one of --basename or --dirname is given then
945 REGEXP is only matched against the specified part of the full
948 When the optional --group-by-objfile flag is used the output
949 format is changed, the results are now a list of object files
950 (executable and libraries) with the source files that are
951 associated with each object file.
953 The results from -file-list-exec-source-files now include a
954 'debug-fully-read' field which takes the value 'true' or 'false'.
955 A 'true' value indicates the source file is from a compilation
956 unit that has had its debug information fully read in by GDB, a
957 value of 'false' indicates GDB has only performed a partial scan
958 of the debug information so far.
960 * GDB now supports core file debugging for x86_64 Cygwin programs.
962 * GDB will now look for the .gdbinit file in a config directory before
963 looking for ~/.gdbinit. The file is searched for in the following
964 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
965 $HOME/.gdbinit. On Apple hosts the search order is instead:
966 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
968 * GDB now supports fixed point types which are described in DWARF
969 as base types with a fixed-point encoding. Additionally, support
970 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
973 For Ada, this allows support for fixed point types without requiring
974 the use of the GNAT encoding (based on information added to the type's
975 name following a GNAT-specific format).
977 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
978 or ~/.gdbearlyinit if these files are present. These files are
979 processed earlier than any of the other initialization files and
980 can affect parts of GDB's startup that previously had already been
981 completed before the initialization files were read, for example
982 styling of the initial GDB greeting.
984 * GDB now has two new options "--early-init-command" and
985 "--early-init-eval-command" with corresponding short options "-eix"
986 and "-eiex" that allow options (that would normally appear in a
987 gdbearlyinit file) to be passed on the command line.
989 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
990 now understood by GDB, and can be used to describe the vector
991 registers of a target. The precise requirements of this register
992 feature are documented in the GDB manual.
994 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
995 supported by GDB and describes a new VPR register from the ARM MVE
996 (Helium) extension. See the GDB manual for more information.
1000 ** TUI windows now support mouse actions. The mouse wheel scrolls
1001 the appropriate window.
1003 ** Key combinations that do not have a specific action on the
1004 focused window are passed to GDB. For example, you now can use
1005 Ctrl-Left/Ctrl-Right to move between words in the command window
1006 regardless of which window is in focus. Previously you would
1007 need to focus on the command window for such key combinations to
1012 set debug event-loop
1013 show debug event-loop
1014 Control the display of debug output about GDB's event loop.
1016 set print memory-tag-violations
1017 show print memory-tag-violations
1018 Control whether to display additional information about memory tag violations
1019 when printing pointers and addresses. Architecture support for memory
1020 tagging is required for this option to have an effect.
1022 maintenance flush symbol-cache
1023 maintenance flush register-cache
1024 These new commands are equivalent to the already existing commands
1025 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1027 maintenance flush dcache
1028 A new command to flush the dcache.
1030 maintenance info target-sections
1031 Print GDB's internal target sections table.
1033 maintenance info jit
1034 Print the JIT code objects in the inferior known to GDB.
1036 memory-tag show-logical-tag POINTER
1037 Print the logical tag for POINTER.
1038 memory-tag with-logical-tag POINTER TAG
1039 Print POINTER with logical tag TAG.
1040 memory-tag show-allocation-tag ADDRESS
1041 Print the allocation tag for ADDRESS.
1042 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1043 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1044 memory-tag check POINTER
1045 Validate that POINTER's logical tag matches the allocation tag.
1047 set startup-quietly on|off
1048 show startup-quietly
1049 When 'on', this causes GDB to act as if "-silent" were passed on the
1050 command line. This command needs to be added to an early
1051 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1054 set print type hex on|off
1056 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1057 and offsets of struct members. When 'off', decimal notation is used.
1059 set python ignore-environment on|off
1060 show python ignore-environment
1061 When 'on', this causes GDB's builtin Python to ignore any
1062 environment variables that would otherwise affect how Python
1063 behaves. This command needs to be added to an early initialization
1064 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1066 set python dont-write-bytecode auto|on|off
1067 show python dont-write-bytecode
1068 When 'on', this causes GDB's builtin Python to not write any
1069 byte-code (.pyc files) to disk. This command needs to be added to
1070 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1071 order to affect GDB. When 'off' byte-code will always be written.
1072 When set to 'auto' (the default) Python will check the
1073 PYTHONDONTWRITEBYTECODE environment variable.
1077 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1078 [-force-condition] [if CONDITION]
1079 This command would previously refuse setting a breakpoint if the
1080 CONDITION expression is invalid at a location. It now accepts and
1081 defines the breakpoint if there is at least one location at which
1082 the CONDITION is valid. The locations for which the CONDITION is
1083 invalid, are automatically disabled. If CONDITION is invalid at all
1084 of the locations, setting the breakpoint is still rejected. However,
1085 the '-force-condition' flag can be used in this case for forcing GDB to
1086 define the breakpoint, making all the current locations automatically
1087 disabled. This may be useful if the user knows the condition will
1088 become meaningful at a future location, e.g. due to a shared library
1091 condition [-force] N COND
1092 The behavior of this command is changed the same way for the 'break'
1093 command as explained above. The '-force' flag can be used to force
1094 GDB into defining the condition even when COND is invalid for all the
1095 current locations of breakpoint N.
1098 maintenance flush-symbol-cache
1099 These commands are deprecated in favor of the new commands
1100 'maintenance flush register-cache' and 'maintenance flush
1101 symbol-cache' respectively.
1103 set style version foreground COLOR
1104 set style version background COLOR
1105 set style version intensity VALUE
1106 Control the styling of GDB's version number text.
1109 When the ID parameter is omitted, then this command prints information
1110 about the current inferior. When the ID parameter is present, the
1111 behavior of the command is unchanged and have the inferior ID become
1112 the current inferior.
1114 maintenance info sections
1115 The ALLOBJ keyword has been replaced with an -all-objects command
1116 line flag. It is now possible to filter which sections are printed
1117 even when -all-objects is passed.
1119 ptype[/FLAGS] TYPE | EXPRESSION
1120 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1121 notation is used when printing sizes and offsets of struct members.
1122 When '/d' is set, decimal notation is used when printing sizes and
1123 offsets of struct members. Default behavior is given by 'show print
1127 The info sources command output has been restructured. The results
1128 are now based around a list of objfiles (executable and libraries),
1129 and for each objfile the source files that are part of that objfile
1132 * Removed targets and native configurations
1134 ARM Symbian arm*-*-symbianelf*
1136 * New remote packets
1139 Request the remote to send allocation tags for a particular memory range.
1141 Request the remote to store the specified allocation tags to the requested
1146 ** Improved support for rvalue reference values:
1147 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1148 value-referenced-value procedure now handles rvalue reference
1151 ** New procedures for obtaining value variants:
1152 value-reference-value, value-rvalue-reference-value and
1155 ** Temporary breakpoints can now be created with make-breakpoint and
1156 tested for using breakpoint-temporary?.
1160 ** Inferior objects now contain a read-only 'connection_num' attribute that
1161 gives the connection number as seen in 'info connections' and
1164 ** New method gdb.Frame.level() which returns the stack level of the
1167 ** New method gdb.PendingFrame.level() which returns the stack level
1168 of the frame object.
1170 ** When hitting a catchpoint, the Python API will now emit a
1171 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1172 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1174 ** Python TUI windows can now receive mouse click events. If the
1175 Window object implements the click method, it is called for each
1176 mouse click event in this window.
1178 *** Changes in GDB 10
1180 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1181 and "org.gnu.gdb.arc.aux". The old names are still supported but
1182 must be considered obsolete. They will be deprecated after some
1185 * Help and apropos commands will now show the documentation of a
1186 command only once, even if that command has one or more aliases.
1187 These commands now show the command name, then all of its aliases,
1188 and finally the description of the command.
1190 * 'help aliases' now shows only the user defined aliases. GDB predefined
1191 aliases are shown together with their aliased command.
1193 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1194 debugging information as well as source code.
1196 When built with debuginfod, GDB can automatically query debuginfod
1197 servers for the separate debug files and source code of the executable
1200 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1201 requires libdebuginfod, the debuginfod client library).
1203 debuginfod is distributed with elfutils, starting with version 0.178.
1205 You can get the latest version from https://sourceware.org/elfutils.
1207 * Multi-target debugging support
1209 GDB now supports debugging multiple target connections
1210 simultaneously. For example, you can now have each inferior
1211 connected to different remote servers running in different machines,
1212 or have one inferior debugging a local native process, an inferior
1213 debugging a core dump, etc.
1215 This support is experimental and comes with some limitations -- you
1216 can only resume multiple targets simultaneously if all targets
1217 support non-stop mode, and all remote stubs or servers must support
1218 the same set of remote protocol features exactly. See also "info
1219 connections" and "add-inferior -no-connection" below, and "maint set
1220 target-non-stop" in the user manual.
1222 * New features in the GDB remote stub, GDBserver
1224 ** GDBserver is now supported on ARC GNU/Linux.
1226 ** GDBserver is now supported on RISC-V GNU/Linux.
1228 ** GDBserver no longer supports these host triplets:
1230 i[34567]86-*-lynxos*
1239 i[34567]86-*-mingw32ce*
1241 * Debugging MS-Windows processes now sets $_exitsignal when the
1242 inferior is terminated by a signal, instead of setting $_exitcode.
1244 * Multithreaded symbol loading has now been enabled by default on systems
1245 that support it (see entry for GDB 9, below), providing faster
1246 performance for programs with many symbols.
1248 * The $_siginfo convenience variable now also works on Windows targets,
1249 and will display the EXCEPTION_RECORD of the last handled exception.
1251 * TUI windows can now be arranged horizontally.
1253 * The command history filename can now be set to the empty string
1254 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1255 the environment. The effect of setting this filename to the empty
1256 string is that GDB will not try to load any previous command
1259 * On Windows targets, it is now possible to debug 32-bit programs with a
1264 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1265 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1266 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1267 running process, this new option indicates whether to detect
1268 a mismatch between the current executable file loaded by GDB and the
1269 executable file used to start the process. If 'ask', the default,
1270 display a warning and ask the user whether to load the process
1271 executable file; if 'warn', just display a warning; if 'off', don't
1272 attempt to detect a mismatch.
1274 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1275 Define a new TUI layout, specifying its name and the windows that
1278 maintenance print xml-tdesc [FILE]
1279 Prints the current target description as an XML document. If the
1280 optional FILE is provided (which is an XML target description) then
1281 the target description is read from FILE into GDB, and then
1284 maintenance print core-file-backed-mappings
1285 Prints file-backed mappings loaded from a core file's note section.
1286 Output is expected to be similar to that of "info proc mappings".
1288 set debug fortran-array-slicing on|off
1289 show debug fortran-array-slicing
1290 Print debugging when taking slices of Fortran arrays.
1292 set fortran repack-array-slices on|off
1293 show fortran repack-array-slices
1294 When taking slices from Fortran arrays and strings, if the slice is
1295 non-contiguous within the original value then, when this option is
1296 on, the new value will be repacked into a single contiguous value.
1297 When this option is off, then the value returned will consist of a
1298 descriptor that describes the slice within the memory of the
1299 original parent value.
1303 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1304 The alias command can now specify default args for an alias.
1305 GDB automatically prepends the alias default args to the argument list
1306 provided explicitly by the user.
1307 For example, to have a backtrace with full details, you can define
1308 an alias 'bt_ALL' as
1309 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1310 -past-main -past-entry -full'.
1311 Alias default arguments can also use a set of nested 'with' commands,
1312 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1313 defines the alias pp10 that will pretty print a maximum of 10 elements
1314 of the given expression (if the expression is an array).
1318 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1319 BPF bpf-unknown-none
1324 ** gdb.register_window_type can be used to implement new TUI windows
1327 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1328 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1329 field of a dynamic type may have None for its "bitpos" attribute
1332 ** Commands written in Python can be in the "TUI" help class by
1333 registering with the new constant gdb.COMMAND_TUI.
1335 ** New method gdb.PendingFrame.architecture () to retrieve the
1336 architecture of the pending frame.
1338 ** New gdb.Architecture.registers method that returns a
1339 gdb.RegisterDescriptorIterator object, an iterator that returns
1340 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1341 way to query the registers available for an architecture.
1343 ** New gdb.Architecture.register_groups method that returns a
1344 gdb.RegisterGroupIterator object, an iterator that returns
1345 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1346 discover the available register groups.
1350 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1352 ** Procedures 'memory-port-read-buffer-size',
1353 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1354 and 'set-memory-port-write-buffer-size!' are deprecated. When
1355 using Guile 2.2 and later, users who need to control the size of
1356 a memory port's internal buffer can use the 'setvbuf' procedure.
1358 *** Changes in GDB 9
1360 * 'thread-exited' event is now available in the annotations interface.
1362 * New built-in convenience variables $_gdb_major and $_gdb_minor
1363 provide the GDB version. They are handy for conditionally using
1364 features available only in or since specific GDB versions, in
1365 scripts that should work error-free with many different versions,
1366 such as in system-wide init files.
1368 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1369 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1370 of the GDB settings and the GDB maintenance settings. They are handy
1371 for changing the logic of user defined commands depending on the
1372 current GDB settings.
1374 * GDB now supports Thread Local Storage (TLS) variables on several
1375 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1376 architectures require kernel changes. TLS is not yet supported for
1377 amd64 and i386 process core dumps.
1379 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1380 addresses that required unmasking are shown in the backtrace with the
1383 * Two new convenience functions $_cimag and $_creal that extract the
1384 imaginary and real parts respectively from complex numbers.
1386 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1387 provide the exitcode or exit status of the shell commands launched by
1388 GDB commands such as "shell", "pipe" and "make".
1390 * The command define-prefix can now define user defined prefix commands.
1391 User defined commands can now be defined using these user defined prefix
1394 * Command names can now use the . character.
1396 * The RX port now supports XML target descriptions.
1398 * GDB now shows the Ada task names at more places, e.g. in task switching
1401 * GDB can now be compiled with Python 3 on Windows.
1403 * New convenience variable $_ada_exception holds the address of the
1404 Ada exception being thrown. This is set by Ada-related catchpoints.
1406 * GDB can now place breakpoints on nested functions and subroutines in
1407 Fortran code. The '::' operator can be used between parent and
1408 child scopes when placing breakpoints, for example:
1410 (gdb) break outer_function::inner_function
1412 The 'outer_function::' prefix is only needed if 'inner_function' is
1413 not visible in the current scope.
1415 * In addition to the system-wide gdbinit file, if configured with
1416 --with-system-gdbinit-dir, GDB will now also load files in that directory
1417 as system gdbinit files, unless the -nx or -n flag is provided. Files
1418 with extensions .gdb, .py and .scm are supported as long as GDB was
1419 compiled with support for that language.
1421 * GDB now supports multithreaded symbol loading for higher performance.
1422 This feature is still in testing, so it is disabled by default. You
1423 can turn it on using 'maint set worker-threads unlimited'.
1427 ** The gdb.Value type has a new method 'format_string' which returns a
1428 string representing the value. The formatting is controlled by the
1429 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1430 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1431 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1433 ** gdb.Type has a new property 'objfile' which returns the objfile the
1434 type was defined in.
1436 ** The frame information printed by the python frame filtering code
1437 is now consistent with what the 'backtrace' command prints when
1438 there are no filters, or when the 'backtrace' '-no-filters' option
1441 ** The new function gdb.lookup_static_symbol can be used to look up
1442 symbols with static linkage.
1444 ** The new function gdb.lookup_static_symbols can be used to look up
1445 all static symbols with static linkage.
1447 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1448 'lookup_static_symbol' to lookup a symbol from this objfile only.
1450 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1451 this block (e.g. block['local_variable']).
1455 | [COMMAND] | SHELL_COMMAND
1456 | -d DELIM COMMAND DELIM SHELL_COMMAND
1457 pipe [COMMAND] | SHELL_COMMAND
1458 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1459 Executes COMMAND and sends its output to SHELL_COMMAND.
1460 With no COMMAND, repeat the last executed command
1461 and send its output to SHELL_COMMAND.
1463 define-prefix COMMAND
1464 Define or mark a command as a user-defined prefix command.
1466 with SETTING [VALUE] [-- COMMAND]
1467 w SETTING [VALUE] [-- COMMAND]
1468 Temporarily set SETTING, run COMMAND, and restore SETTING.
1469 Usage: with SETTING -- COMMAND
1470 With no COMMAND, repeats the last executed command.
1471 SETTING is any GDB setting you can change with the "set"
1472 subcommands. For example, 'with language c -- print someobj'
1473 temporarily switches to the C language in order to print someobj.
1474 Settings can be combined: 'w lang c -- w print elements unlimited --
1475 usercmd' switches to the C language and runs usercmd with no limit
1476 of array elements to print.
1478 maint with SETTING [VALUE] [-- COMMAND]
1479 Like "with", but works with "maintenance set" settings.
1481 set may-call-functions [on|off]
1482 show may-call-functions
1483 This controls whether GDB will attempt to call functions in
1484 the program, such as with expressions in the print command. It
1485 defaults to on. Calling functions in the program being debugged
1486 can have undesired side effects. It is now possible to forbid
1487 such function calls. If function calls are forbidden, GDB will throw
1488 an error when a command (such as print expression) calls a function
1491 set print finish [on|off]
1493 This controls whether the `finish' command will display the value
1494 that is returned by the current function. When `off', the value is
1495 still entered into the value history, but it is not printed. The
1499 show print max-depth
1500 Allows deeply nested structures to be simplified when printing by
1501 replacing deeply nested parts (beyond the max-depth) with ellipses.
1502 The default max-depth is 20, but this can be set to unlimited to get
1503 the old behavior back.
1505 set print raw-values [on|off]
1506 show print raw-values
1507 By default, GDB applies the enabled pretty printers when printing a
1508 value. This allows to ignore the enabled pretty printers for a series
1509 of commands. The default is 'off'.
1511 set logging debugredirect [on|off]
1512 By default, GDB debug output will go to both the terminal and the logfile.
1513 Set if you want debug output to go only to the log file.
1515 set style title foreground COLOR
1516 set style title background COLOR
1517 set style title intensity VALUE
1518 Control the styling of titles.
1520 set style highlight foreground COLOR
1521 set style highlight background COLOR
1522 set style highlight intensity VALUE
1523 Control the styling of highlightings.
1525 maint set worker-threads
1526 maint show worker-threads
1527 Control the number of worker threads that can be used by GDB. The
1528 default is 0. "unlimited" lets GDB choose a number that is
1529 reasonable. Currently worker threads are only used when demangling
1530 the names of linker symbols.
1532 set style tui-border foreground COLOR
1533 set style tui-border background COLOR
1534 Control the styling of TUI borders.
1536 set style tui-active-border foreground COLOR
1537 set style tui-active-border background COLOR
1538 Control the styling of the active TUI border.
1540 maint set test-settings KIND
1541 maint show test-settings KIND
1542 A set of commands used by the testsuite for exercising the settings
1545 maint set tui-resize-message [on|off]
1546 maint show tui-resize-message
1547 Control whether GDB prints a message each time the terminal is
1548 resized when in TUI mode. This is primarily useful for testing the
1551 set print frame-info [short-location|location|location-and-address
1552 |source-and-location|source-line|auto]
1553 show print frame-info
1554 This controls what frame information is printed by the commands printing
1555 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1556 'frame', 'stepi'. The python frame filtering also respect this setting.
1557 The 'backtrace' '-frame-info' option can override this global setting.
1559 set tui compact-source
1560 show tui compact-source
1562 Enable the "compact" display mode for the TUI source window. The
1563 compact display uses only as much space as is needed for the line
1564 numbers in the current file, and only a single space to separate the
1565 line numbers from the source.
1567 info modules [-q] [REGEXP]
1568 Return a list of Fortran modules matching REGEXP, or all modules if
1571 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1572 Return a list of functions within all modules, grouped by module.
1573 The list of functions can be restricted with the optional regular
1574 expressions. MODULE_REGEXP matches against the module name,
1575 TYPE_REGEXP matches against the function type signature, and REGEXP
1576 matches against the function name.
1578 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1579 Return a list of variables within all modules, grouped by module.
1580 The list of variables can be restricted with the optional regular
1581 expressions. MODULE_REGEXP matches against the module name,
1582 TYPE_REGEXP matches against the variable type, and REGEXP matches
1583 against the variable name.
1585 set debug remote-packet-max-chars
1586 show debug remote-packet-max-chars
1587 Controls the number of characters to output in a remote packet when using
1589 The default is 512 bytes.
1592 Lists the target connections currently in use.
1597 The "help" command uses the title style to enhance the
1598 readibility of its output by styling the classes and
1602 Similarly to "help", the "apropos" command also uses the
1603 title style for the command names. "apropos" accepts now
1604 a flag "-v" (verbose) to show the full documentation
1605 of matching commands and to use the highlight style to mark
1606 the documentation parts matching REGEXP.
1610 The GDB printf and eval commands can now print C-style and Ada-style
1611 string convenience variables without calling functions in the program.
1612 This allows to do formatted printing of strings without having
1613 a running inferior, or when debugging a core dump.
1615 info sources [-dirname | -basename] [--] [REGEXP]
1616 This command has now optional arguments to only print the files
1617 whose names match REGEXP. The arguments -dirname and -basename
1618 allow to restrict matching respectively to the dirname and basename
1622 The "show style" and its subcommands are now styling
1623 a style name in their output using its own style, to help
1624 the user visualize the different styles.
1626 set print frame-arguments
1627 The new value 'presence' indicates to only indicate the presence of
1628 arguments using ..., instead of printing argument names and values.
1630 set print raw-frame-arguments
1631 show print raw-frame-arguments
1633 These commands replace the similarly-named "set/show print raw
1634 frame-arguments" commands (now with a dash instead of a space). The
1635 old commands are now deprecated and may be removed in a future
1638 add-inferior [-no-connection]
1639 The add-inferior command now supports a "-no-connection" flag that
1640 makes the new inferior start with no target connection associated.
1641 By default, the new inferior inherits the target connection of the
1642 current inferior. See also "info connections".
1645 This command's output now includes a new "Connection" column
1646 indicating which target connection an inferior is bound to. See
1647 "info connections" above.
1649 maint test-options require-delimiter
1650 maint test-options unknown-is-error
1651 maint test-options unknown-is-operand
1652 maint show test-options-completion-result
1653 Commands used by the testsuite to validate the command options
1656 focus, winheight, +, -, >, <
1657 These commands are now case-sensitive.
1659 * New command options, command completion
1661 GDB now has a standard infrastructure to support dash-style command
1662 options ('-OPT'). One benefit is that commands that use it can
1663 easily support completion of command line arguments. Try "CMD
1664 -[TAB]" or "help CMD" to find options supported by a command. Over
1665 time, we intend to migrate most commands to this infrastructure. A
1666 number of commands got support for new command options in this
1669 ** The "print" and "compile print" commands now support a number of
1670 options that allow overriding relevant global print settings as
1671 set by "set print" subcommands:
1675 -array-indexes [on|off]
1676 -elements NUMBER|unlimited
1680 -raw-values [on|off]
1681 -repeats NUMBER|unlimited
1682 -static-members [on|off]
1687 Note that because the "print"/"compile print" commands accept
1688 arbitrary expressions which may look like options (including
1689 abbreviations), if you specify any command option, then you must
1690 use a double dash ("--") to mark the end of argument processing.
1692 ** The "backtrace" command now supports a number of options that
1693 allow overriding relevant global print settings as set by "set
1694 backtrace" and "set print" subcommands:
1696 -entry-values no|only|preferred|if-needed|both|compact|default
1697 -frame-arguments all|scalars|none
1698 -raw-frame-arguments [on|off]
1699 -frame-info auto|source-line|location|source-and-location
1700 |location-and-address|short-location
1702 -past-entry [on|off]
1704 In addition, the full/no-filters/hide qualifiers are now also
1705 exposed as command options too:
1711 ** The "frame apply", "tfaas" and "faas" commands similarly now
1712 support the following options:
1715 -past-entry [on|off]
1717 ** The new "info sources" options -dirname and -basename options
1718 are using the standard '-OPT' infrastructure.
1720 All options above can also be abbreviated. The argument of boolean
1721 (on/off) options can be 0/1 too, and also the argument is assumed
1722 "on" if omitted. This allows writing compact command invocations,
1725 (gdb) p -ra -p -o 0 -- *myptr
1727 The above is equivalent to:
1729 (gdb) print -raw-values -pretty -object off -- *myptr
1731 ** The "info types" command now supports the '-q' flag to disable
1732 printing of some header information in a similar fashion to "info
1733 variables" and "info functions".
1735 ** The "info variables", "info functions", and "whereis" commands
1736 now take a '-n' flag that excludes non-debug symbols (symbols
1737 from the symbol table, not from the debug info such as DWARF)
1740 * Completion improvements
1742 ** GDB can now complete the options of the "thread apply all" and
1743 "taas" commands, and their "-ascending" option can now be
1746 ** GDB can now complete the options of the "info threads", "info
1747 functions", "info variables", "info locals", and "info args"
1750 ** GDB can now complete the options of the "compile file" and
1751 "compile code" commands. The "compile file" command now
1752 completes on filenames.
1754 ** GDB can now complete the backtrace command's
1755 "full/no-filters/hide" qualifiers.
1757 * In settings, you can now abbreviate "unlimited".
1759 E.g., "set print elements u" is now equivalent to "set print
1760 elements unlimited".
1765 This lists all the possible completions for the rest of the line, if it
1766 were to be given as a command itself. This is intended for use by MI
1767 frontends in cases when separate CLI and MI channels cannot be used.
1769 -catch-throw, -catch-rethrow, and -catch-catch
1770 These can be used to catch C++ exceptions in a similar fashion to
1771 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1773 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1774 These commands are the MI equivalent of the CLI commands 'info
1775 functions', 'info types', and 'info variables' respectively.
1777 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1780 -symbol-info-module-functions and -symbol-info-module-variables.
1781 These commands are the MI equivalent of the CLI commands 'info
1782 module functions' and 'info module variables'.
1786 ** The default version of the MI interpreter is now 3 (-i=mi3).
1788 ** The output of information about multi-location breakpoints (which is
1789 syntactically incorrect in MI 2) has changed in MI 3. This affects
1790 the following commands and events:
1794 - =breakpoint-created
1795 - =breakpoint-modified
1797 The -fix-multi-location-breakpoint-output command can be used to enable
1798 this behavior with previous MI versions.
1800 ** Backtraces and frames include a new optional field addr_flags which is
1801 given after the addr field. On AArch64 this contains PAC if the address
1802 has been masked in the frame. On all other targets the field is not
1807 The testsuite now creates the files gdb.cmd (containing the arguments
1808 used to launch GDB) and gdb.in (containing all the commands sent to
1809 GDB) in the output directory for each test script. Multiple invocations
1810 are appended with .1, .2, .3 etc.
1812 * Building GDB and GDBserver now requires GNU make >= 3.82.
1814 Using another implementation of the make program or an earlier version of
1815 GNU make to build GDB or GDBserver is not supported.
1817 * Building GDB now requires GNU readline >= 7.0.
1819 GDB now bundles GNU readline 8.0, but if you choose to use
1820 --with-system-readline, only readline >= 7.0 can be used.
1822 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1823 from .inputrc to bind keys in this keymap. This feature is only
1824 available when gdb is built against GNU readline 8.0 or later.
1826 * Removed targets and native configurations
1828 GDB no longer supports debugging the Cell Broadband Engine. This includes
1829 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1830 of Cell/B.E. applications that use both the PPU and SPU architectures.
1836 * Removed targets and native configurations
1838 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1839 sparc*-*-solaris2.10
1841 *** Changes in GDB 8.3
1843 * GDB and GDBserver now support access to additional registers on
1844 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1847 * GDB now has experimental support for the compilation and injection of
1848 C++ source code into the inferior. This beta release does not include
1849 support for several language features, such as templates, constructors,
1852 This feature requires GCC 7.1 or higher built with libcp1.so
1855 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1856 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1857 'ADDRESS:PORT' method.
1859 * DWARF index cache: GDB can now automatically save indices of DWARF
1860 symbols on disk to speed up further loading of the same binaries.
1862 * Ada task switching is now supported on aarch64-elf targets when
1863 debugging a program using the Ravenscar Profile. For more information,
1864 see the "Tasking Support when using the Ravenscar Profile" section
1865 in the GDB user manual.
1867 * GDB in batch mode now exits with status 1 if the last command to be
1870 * The RISC-V target now supports target descriptions.
1872 * System call catchpoints now support system call aliases on FreeBSD.
1873 When the ABI of a system call changes in FreeBSD, this is
1874 implemented by leaving a compatibility system call using the old ABI
1875 at the existing number and allocating a new system call number for
1876 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1877 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1878 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1879 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1880 so that a system call catchpoint for the 'kevent' system call will
1881 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1882 binaries. This ensures that 'kevent' system calls are caught for
1883 binaries using either the old or new ABIs.
1885 * Terminal styling is now available for the CLI and the TUI. GNU
1886 Source Highlight can additionally be used to provide styling of
1887 source code snippets. See the "set style" commands, below, for more
1890 * Removed support for old demangling styles arm, edg, gnu, hp and
1895 set debug compile-cplus-types
1896 show debug compile-cplus-types
1897 Control the display of debug output about type conversion in the
1898 C++ compile feature. Commands have no effect while compiling
1899 for other languages.
1903 Control whether debug output about files/functions skipping is
1906 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1907 Apply a command to some frames.
1908 FLAG arguments allow to control what output to produce and how to handle
1909 errors raised when applying COMMAND to a frame.
1912 Apply a command to all threads (ignoring errors and empty output).
1913 Shortcut for 'thread apply all -s COMMAND'.
1916 Apply a command to all frames (ignoring errors and empty output).
1917 Shortcut for 'frame apply all -s COMMAND'.
1920 Apply a command to all frames of all threads (ignoring errors and empty
1922 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1924 maint set dwarf unwinders (on|off)
1925 maint show dwarf unwinders
1926 Control whether DWARF unwinders can be used.
1929 Display a list of open files for a process.
1933 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1934 These commands all now take a frame specification which
1935 is either a frame level, or one of the keywords 'level', 'address',
1936 'function', or 'view' followed by a parameter. Selecting a frame by
1937 address, or viewing a frame outside the current backtrace now
1938 requires the use of a keyword. Selecting a frame by level is
1939 unchanged. The MI comment "-stack-select-frame" is unchanged.
1941 target remote FILENAME
1942 target extended-remote FILENAME
1943 If FILENAME is a Unix domain socket, GDB will attempt to connect
1944 to this socket instead of opening FILENAME as a character device.
1946 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1947 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1948 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1949 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1950 These commands can now print only the searched entities
1951 matching the provided regexp(s), giving a condition
1952 on the entity names or entity types. The flag -q disables
1953 printing headers or informations messages.
1959 These commands now determine the syntax for the shown entities
1960 according to the language chosen by `set language'. In particular,
1961 `set language auto' means to automatically choose the language of
1964 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1965 The 'thread apply' command accepts new FLAG arguments.
1966 FLAG arguments allow to control what output to produce and how to handle
1967 errors raised when applying COMMAND to a thread.
1969 set tui tab-width NCHARS
1970 show tui tab-width NCHARS
1971 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1973 set style enabled [on|off]
1975 Enable or disable terminal styling. Styling is enabled by default
1976 on most hosts, but disabled by default when in batch mode.
1978 set style sources [on|off]
1980 Enable or disable source code styling. Source code styling is
1981 enabled by default, but only takes effect if styling in general is
1982 enabled, and if GDB was linked with GNU Source Highlight.
1984 set style filename foreground COLOR
1985 set style filename background COLOR
1986 set style filename intensity VALUE
1987 Control the styling of file names.
1989 set style function foreground COLOR
1990 set style function background COLOR
1991 set style function intensity VALUE
1992 Control the styling of function names.
1994 set style variable foreground COLOR
1995 set style variable background COLOR
1996 set style variable intensity VALUE
1997 Control the styling of variable names.
1999 set style address foreground COLOR
2000 set style address background COLOR
2001 set style address intensity VALUE
2002 Control the styling of addresses.
2006 ** The '-data-disassemble' MI command now accepts an '-a' option to
2007 disassemble the whole function surrounding the given program
2008 counter value or function name. Support for this feature can be
2009 verified by using the "-list-features" command, which should
2010 contain "data-disassemble-a-option".
2012 ** Command responses and notifications that include a frame now include
2013 the frame's architecture in a new "arch" attribute.
2015 * New native configurations
2017 GNU/Linux/RISC-V riscv*-*-linux*
2018 FreeBSD/riscv riscv*-*-freebsd*
2022 GNU/Linux/RISC-V riscv*-*-linux*
2023 CSKY ELF csky*-*-elf
2024 CSKY GNU/LINUX csky*-*-linux
2025 FreeBSD/riscv riscv*-*-freebsd*
2027 GNU/Linux/OpenRISC or1k*-*-linux*
2031 GDB no longer supports native debugging on versions of MS-Windows
2036 ** GDB no longer supports Python versions less than 2.6.
2038 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2039 space associated to that inferior.
2041 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2042 of objfiles associated to that program space.
2044 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2045 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2048 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2049 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2050 correct and did not work properly.
2052 ** The gdb.Value type has a new constructor, which is used to construct a
2053 gdb.Value from a Python buffer object and a gdb.Type.
2059 Enable or disable the undefined behavior sanitizer. This is
2060 disabled by default, but passing --enable-ubsan=yes or
2061 --enable-ubsan=auto to configure will enable it. Enabling this can
2062 cause a performance penalty. The undefined behavior sanitizer was
2063 first introduced in GCC 4.9.
2065 *** Changes in GDB 8.2
2067 * The 'set disassembler-options' command now supports specifying options
2068 for the MIPS target.
2070 * The 'symbol-file' command now accepts an '-o' option to add a relative
2071 offset to all sections.
2073 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2074 a relative offset to all sections, but it allows to override the load
2075 address of individual sections using '-s'.
2077 * The 'add-symbol-file' command no longer requires the second argument
2078 (address of the text section).
2080 * The endianness used with the 'set endian auto' mode in the absence of
2081 an executable selected for debugging is now the last endianness chosen
2082 either by one of the 'set endian big' and 'set endian little' commands
2083 or by inferring from the last executable used, rather than the startup
2086 * The pager now allows a "c" response, meaning to disable the pager
2087 for the rest of the current command.
2089 * The commands 'info variables/functions/types' now show the source line
2090 numbers of symbol definitions when available.
2092 * 'info proc' now works on running processes on FreeBSD systems and core
2093 files created on FreeBSD systems.
2095 * C expressions can now use _Alignof, and C++ expressions can now use
2098 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2099 the vector length while the process is running.
2105 Control display of debugging info regarding the FreeBSD native target.
2107 set|show varsize-limit
2108 This new setting allows the user to control the maximum size of Ada
2109 objects being printed when those objects have a variable type,
2110 instead of that maximum size being hardcoded to 65536 bytes.
2112 set|show record btrace cpu
2113 Controls the processor to be used for enabling errata workarounds for
2114 branch trace decode.
2116 maint check libthread-db
2117 Run integrity checks on the current inferior's thread debugging
2120 maint set check-libthread-db (on|off)
2121 maint show check-libthread-db
2122 Control whether to run integrity checks on inferior specific thread
2123 debugging libraries as they are loaded. The default is not to
2124 perform such checks.
2128 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2130 ** The commands attached to a breakpoint can be set by assigning to
2131 the breakpoint's "commands" field.
2133 ** gdb.execute can now execute multi-line gdb commands.
2135 ** The new functions gdb.convenience_variable and
2136 gdb.set_convenience_variable can be used to get and set the value
2137 of convenience variables.
2139 ** A gdb.Parameter will no longer print the "set" help text on an
2140 ordinary "set"; instead by default a "set" will be silent unless
2141 the get_set_string method returns a non-empty string.
2145 RiscV ELF riscv*-*-elf
2147 * Removed targets and native configurations
2149 m88k running OpenBSD m88*-*-openbsd*
2150 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2151 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2152 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2154 * Aarch64/Linux hardware watchpoints improvements
2156 Hardware watchpoints on unaligned addresses are now properly
2157 supported when running Linux kernel 4.10 or higher: read and access
2158 watchpoints are no longer spuriously missed, and all watchpoints
2159 lengths between 1 and 8 bytes are supported. On older kernels,
2160 watchpoints set on unaligned addresses are no longer missed, with
2161 the tradeoff that there is a possibility of false hits being
2166 --enable-codesign=CERT
2167 This can be used to invoke "codesign -s CERT" after building gdb.
2168 This option is useful on macOS, where code signing is required for
2169 gdb to work properly.
2171 --disable-gdbcli has been removed
2172 This is now silently accepted, but does nothing.
2174 *** Changes in GDB 8.1
2176 * GDB now supports dynamically creating arbitrary register groups specified
2177 in XML target descriptions. This allows for finer grain grouping of
2178 registers on systems with a large amount of registers.
2180 * The 'ptype' command now accepts a '/o' flag, which prints the
2181 offsets and sizes of fields in a struct, like the pahole(1) tool.
2183 * New "--readnever" command line option instructs GDB to not read each
2184 symbol file's symbolic debug information. This makes startup faster
2185 but at the expense of not being able to perform symbolic debugging.
2186 This option is intended for use cases where symbolic debugging will
2187 not be used, e.g., when you only need to dump the debuggee's core.
2189 * GDB now uses the GNU MPFR library, if available, to emulate target
2190 floating-point arithmetic during expression evaluation when the target
2191 uses different floating-point formats than the host. At least version
2192 3.1 of GNU MPFR is required.
2194 * GDB now supports access to the guarded-storage-control registers and the
2195 software-based guarded-storage broadcast control registers on IBM z14.
2197 * On Unix systems, GDB now supports transmitting environment variables
2198 that are to be set or unset to GDBserver. These variables will
2199 affect the environment to be passed to the remote inferior.
2201 To inform GDB of environment variables that are to be transmitted to
2202 GDBserver, use the "set environment" command. Only user set
2203 environment variables are sent to GDBserver.
2205 To inform GDB of environment variables that are to be unset before
2206 the remote inferior is started by the GDBserver, use the "unset
2207 environment" command.
2209 * Completion improvements
2211 ** GDB can now complete function parameters in linespecs and
2212 explicit locations without quoting. When setting breakpoints,
2213 quoting around functions names to help with TAB-completion is
2214 generally no longer necessary. For example, this now completes
2217 (gdb) b function(in[TAB]
2218 (gdb) b function(int)
2220 Related, GDB is no longer confused with completing functions in
2221 C++ anonymous namespaces:
2224 (gdb) b (anonymous namespace)::[TAB][TAB]
2225 (anonymous namespace)::a_function()
2226 (anonymous namespace)::b_function()
2228 ** GDB now has much improved linespec and explicit locations TAB
2229 completion support, that better understands what you're
2230 completing and offers better suggestions. For example, GDB no
2231 longer offers data symbols as possible completions when you're
2232 setting a breakpoint.
2234 ** GDB now TAB-completes label symbol names.
2236 ** The "complete" command now mimics TAB completion accurately.
2238 * New command line options (gcore)
2241 Dump all memory mappings.
2243 * Breakpoints on C++ functions are now set on all scopes by default
2245 By default, breakpoints on functions/methods are now interpreted as
2246 specifying all functions with the given name ignoring missing
2247 leading scopes (namespaces and classes).
2249 For example, assuming a C++ program with symbols named:
2254 both commands "break func()" and "break B::func()" set a breakpoint
2257 You can use the new flag "-qualified" to override this. This makes
2258 GDB interpret the specified function name as a complete
2259 fully-qualified name instead. For example, using the same C++
2260 program, the "break -q B::func" command sets a breakpoint on
2261 "B::func", only. A parameter has been added to the Python
2262 gdb.Breakpoint constructor to achieve the same result when creating
2263 a breakpoint from Python.
2265 * Breakpoints on functions marked with C++ ABI tags
2267 GDB can now set breakpoints on functions marked with C++ ABI tags
2268 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2269 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2271 Functions with a C++11 abi tag are demangled/displayed like this:
2273 function[abi:cxx11](int)
2276 You can now set a breakpoint on such functions simply as if they had
2279 (gdb) b function(int)
2281 Or if you need to disambiguate between tags, like:
2283 (gdb) b function[abi:other_tag](int)
2285 Tab completion was adjusted accordingly as well.
2289 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2290 gdb.new_thread are emitted. See the manual for further
2291 description of these.
2293 ** A new function, "gdb.rbreak" has been added to the Python API.
2294 This function allows the setting of a large number of breakpoints
2295 via a regex pattern in Python. See the manual for further details.
2297 ** Python breakpoints can now accept explicit locations. See the
2298 manual for a further description of this feature.
2301 * New features in the GDB remote stub, GDBserver
2303 ** GDBserver is now able to start inferior processes with a
2304 specified initial working directory.
2306 The user can set the desired working directory to be used from
2307 GDB using the new "set cwd" command.
2309 ** New "--selftest" command line option runs some GDBserver self
2310 tests. These self tests are disabled in releases.
2312 ** On Unix systems, GDBserver now does globbing expansion and variable
2313 substitution in inferior command line arguments.
2315 This is done by starting inferiors using a shell, like GDB does.
2316 See "set startup-with-shell" in the user manual for how to disable
2317 this from GDB when using "target extended-remote". When using
2318 "target remote", you can disable the startup with shell by using the
2319 new "--no-startup-with-shell" GDBserver command line option.
2321 ** On Unix systems, GDBserver now supports receiving environment
2322 variables that are to be set or unset from GDB. These variables
2323 will affect the environment to be passed to the inferior.
2325 * When catching an Ada exception raised with a message, GDB now prints
2326 the message in the catchpoint hit notification. In GDB/MI mode, that
2327 information is provided as an extra field named "exception-message"
2328 in the *stopped notification.
2330 * Trait objects can now be inspected When debugging Rust code. This
2331 requires compiler support which will appear in Rust 1.24.
2333 * New remote packets
2335 QEnvironmentHexEncoded
2336 Inform GDBserver of an environment variable that is to be passed to
2337 the inferior when starting it.
2340 Inform GDBserver of an environment variable that is to be unset
2341 before starting the remote inferior.
2344 Inform GDBserver that the environment should be reset (i.e.,
2345 user-set environment variables should be unset).
2348 Indicates whether the inferior must be started with a shell or not.
2351 Tell GDBserver that the inferior to be started should use a specific
2354 * The "maintenance print c-tdesc" command now takes an optional
2355 argument which is the file name of XML target description.
2357 * The "maintenance selftest" command now takes an optional argument to
2358 filter the tests to be run.
2360 * The "enable", and "disable" commands now accept a range of
2361 breakpoint locations, e.g. "enable 1.3-5".
2366 Set and show the current working directory for the inferior.
2368 set|show compile-gcc
2369 Set and show compilation command used for compiling and injecting code
2370 with the 'compile' commands.
2372 set debug separate-debug-file
2373 show debug separate-debug-file
2374 Control the display of debug output about separate debug file search.
2376 set dump-excluded-mappings
2377 show dump-excluded-mappings
2378 Control whether mappings marked with the VM_DONTDUMP flag should be
2379 dumped when generating a core file.
2381 maint info selftests
2382 List the registered selftests.
2385 Start the debugged program stopping at the first instruction.
2388 Control display of debugging messages related to OpenRISC targets.
2390 set|show print type nested-type-limit
2391 Set and show the limit of nesting level for nested types that the
2392 type printer will show.
2394 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2397 * Safer/improved support for debugging with no debug info
2399 GDB no longer assumes functions with no debug information return
2402 This means that GDB now refuses to call such functions unless you
2403 tell it the function's type, by either casting the call to the
2404 declared return type, or by casting the function to a function
2405 pointer of the right type, and calling that:
2407 (gdb) p getenv ("PATH")
2408 'getenv' has unknown return type; cast the call to its declared return type
2409 (gdb) p (char *) getenv ("PATH")
2410 $1 = 0x7fffffffe "/usr/local/bin:/"...
2411 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2412 $2 = 0x7fffffffe "/usr/local/bin:/"...
2414 Similarly, GDB no longer assumes that global variables with no debug
2415 info have type 'int', and refuses to print the variable's value
2416 unless you tell it the variable's type:
2419 'var' has unknown type; cast it to its declared type
2423 * New native configurations
2425 FreeBSD/aarch64 aarch64*-*-freebsd*
2426 FreeBSD/arm arm*-*-freebsd*
2430 FreeBSD/aarch64 aarch64*-*-freebsd*
2431 FreeBSD/arm arm*-*-freebsd*
2432 OpenRISC ELF or1k*-*-elf
2434 * Removed targets and native configurations
2436 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2438 *** Changes in GDB 8.0
2440 * GDB now supports access to the PKU register on GNU/Linux. The register is
2441 added by the Memory Protection Keys for Userspace feature which will be
2442 available in future Intel CPUs.
2444 * GDB now supports C++11 rvalue references.
2448 ** New functions to start, stop and access a running btrace recording.
2449 ** Rvalue references are now supported in gdb.Type.
2451 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2454 * Building GDB and GDBserver now requires a C++11 compiler.
2456 For example, GCC 4.8 or later.
2458 It is no longer possible to build GDB or GDBserver with a C
2459 compiler. The --disable-build-with-cxx configure option has been
2462 * Building GDB and GDBserver now requires GNU make >= 3.81.
2464 It is no longer supported to build GDB or GDBserver with another
2465 implementation of the make program or an earlier version of GNU make.
2467 * Native debugging on MS-Windows supports command-line redirection
2469 Command-line arguments used for starting programs on MS-Windows can
2470 now include redirection symbols supported by native Windows shells,
2471 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2472 as "run", "start", and "set args", as well as the corresponding MI
2475 * Support for thread names on MS-Windows.
2477 GDB now catches and handles the special exception that programs
2478 running on MS-Windows use to assign names to threads in the
2481 * Support for Java programs compiled with gcj has been removed.
2483 * User commands now accept an unlimited number of arguments.
2484 Previously, only up to 10 was accepted.
2486 * The "eval" command now expands user-defined command arguments.
2488 This makes it easier to process a variable number of arguments:
2493 eval "print $arg%d", $i
2498 * Target descriptions can now describe registers for sparc32 and sparc64.
2500 * GDB now supports DWARF version 5 (debug information format).
2501 Its .debug_names index is not yet supported.
2503 * New native configurations
2505 FreeBSD/mips mips*-*-freebsd
2509 Synopsys ARC arc*-*-elf32
2510 FreeBSD/mips mips*-*-freebsd
2512 * Removed targets and native configurations
2514 Alpha running FreeBSD alpha*-*-freebsd*
2515 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2520 Erases all the flash memory regions reported by the target.
2522 maint print arc arc-instruction address
2523 Print internal disassembler information about instruction at a given address.
2527 set disassembler-options
2528 show disassembler-options
2529 Controls the passing of target specific information to the disassembler.
2530 If it is necessary to specify more than one disassembler option then
2531 multiple options can be placed together into a comma separated list.
2532 The default value is the empty string. Currently, the only supported
2533 targets are ARM, PowerPC and S/390.
2538 Erases all the flash memory regions reported by the target. This is
2539 equivalent to the CLI command flash-erase.
2541 -file-list-shared-libraries
2542 List the shared libraries in the program. This is
2543 equivalent to the CLI command "info shared".
2546 Catchpoints stopping the program when Ada exceptions are
2547 handled. This is equivalent to the CLI command "catch handlers".
2549 *** Changes in GDB 7.12
2551 * GDB and GDBserver now build with a C++ compiler by default.
2553 The --enable-build-with-cxx configure option is now enabled by
2554 default. One must now explicitly configure with
2555 --disable-build-with-cxx in order to build with a C compiler. This
2556 option will be removed in a future release.
2558 * GDBserver now supports recording btrace without maintaining an active
2561 * GDB now supports a negative repeat count in the 'x' command to examine
2562 memory backward from the given address. For example:
2565 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2566 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2567 (gdb) x/-5i 0x0000000000400580
2568 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2569 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2570 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2571 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2572 0x40057b <main(int, char**)+25>:
2573 callq 0x400536 <Func1(int, char const*)>
2575 * Fortran: Support structures with fields of dynamic types and
2576 arrays of dynamic types.
2578 * The symbol dumping maintenance commands have new syntax.
2579 maint print symbols [-pc address] [--] [filename]
2580 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2581 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2582 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2583 maint print msymbols [-objfile objfile] [--] [filename]
2585 * GDB now supports multibit bitfields and enums in target register
2588 * New Python-based convenience function $_as_string(val), which returns
2589 the textual representation of a value. This function is especially
2590 useful to obtain the text label of an enum value.
2592 * Intel MPX bound violation handling.
2594 Segmentation faults caused by a Intel MPX boundary violation
2595 now display the kind of violation (upper or lower), the memory
2596 address accessed and the memory bounds, along with the usual
2597 signal received and code location.
2601 Program received signal SIGSEGV, Segmentation fault
2602 Upper bound violation while accessing address 0x7fffffffc3b3
2603 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2604 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2606 * Rust language support.
2607 GDB now supports debugging programs written in the Rust programming
2608 language. See https://www.rust-lang.org/ for more information about
2611 * Support for running interpreters on specified input/output devices
2613 GDB now supports a new mechanism that allows frontends to provide
2614 fully featured GDB console views, as a better alternative to
2615 building such views on top of the "-interpreter-exec console"
2616 command. See the new "new-ui" command below. With that command,
2617 frontends can now start GDB in the traditional command-line mode
2618 running in an embedded terminal emulator widget, and create a
2619 separate MI interpreter running on a specified i/o device. In this
2620 way, GDB handles line editing, history, tab completion, etc. in the
2621 console all by itself, and the GUI uses the separate MI interpreter
2622 for its own control and synchronization, invisible to the command
2625 * The "catch syscall" command catches groups of related syscalls.
2627 The "catch syscall" command now supports catching a group of related
2628 syscalls using the 'group:' or 'g:' prefix.
2633 skip -gfile file-glob-pattern
2634 skip -function function
2635 skip -rfunction regular-expression
2636 A generalized form of the skip command, with new support for
2637 glob-style file names and regular expressions for function names.
2638 Additionally, a file spec and a function spec may now be combined.
2640 maint info line-table REGEXP
2641 Display the contents of GDB's internal line table data structure.
2644 Run any GDB unit tests that were compiled in.
2647 Start a new user interface instance running INTERP as interpreter,
2648 using the TTY file for input/output.
2652 ** gdb.Breakpoint objects have a new attribute "pending", which
2653 indicates whether the breakpoint is pending.
2654 ** Three new breakpoint-related events have been added:
2655 gdb.breakpoint_created, gdb.breakpoint_modified, and
2656 gdb.breakpoint_deleted.
2658 signal-event EVENTID
2659 Signal ("set") the given MS-Windows event object. This is used in
2660 conjunction with the Windows JIT debugging (AeDebug) support, where
2661 the OS suspends a crashing process until a debugger can attach to
2662 it. Resuming the crashing process, in order to debug it, is done by
2663 signalling an event.
2665 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2666 was added in GDBserver, including JIT compiling fast tracepoint's
2667 conditional expression bytecode into native code.
2669 * Support for various remote target protocols and ROM monitors has
2672 target m32rsdi Remote M32R debugging over SDI
2673 target mips MIPS remote debugging protocol
2674 target pmon PMON ROM monitor
2675 target ddb NEC's DDB variant of PMON for Vr4300
2676 target rockhopper NEC RockHopper variant of PMON
2677 target lsi LSI variant of PMO
2679 * Support for tracepoints and fast tracepoints on powerpc-linux,
2680 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2681 including JIT compiling fast tracepoint's conditional expression
2682 bytecode into native code.
2684 * MI async record =record-started now includes the method and format used for
2685 recording. For example:
2687 =record-started,thread-group="i1",method="btrace",format="bts"
2689 * MI async record =thread-selected now includes the frame field. For example:
2691 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2695 Andes NDS32 nds32*-*-elf
2697 *** Changes in GDB 7.11
2699 * GDB now supports debugging kernel-based threads on FreeBSD.
2701 * Per-inferior thread numbers
2703 Thread numbers are now per inferior instead of global. If you're
2704 debugging multiple inferiors, GDB displays thread IDs using a
2705 qualified INF_NUM.THR_NUM form. For example:
2709 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2710 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2711 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2712 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2714 As consequence, thread numbers as visible in the $_thread
2715 convenience variable and in Python's InferiorThread.num attribute
2716 are no longer unique between inferiors.
2718 GDB now maintains a second thread ID per thread, referred to as the
2719 global thread ID, which is the new equivalent of thread numbers in
2720 previous releases. See also $_gthread below.
2722 For backwards compatibility, MI's thread IDs always refer to global
2725 * Commands that accept thread IDs now accept the qualified
2726 INF_NUM.THR_NUM form as well. For example:
2729 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2732 * In commands that accept a list of thread IDs, you can now refer to
2733 all threads of an inferior using a star wildcard. GDB accepts
2734 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2735 refer to all threads of the current inferior. For example, "info
2738 * You can use "info threads -gid" to display the global thread ID of
2741 * The new convenience variable $_gthread holds the global number of
2744 * The new convenience variable $_inferior holds the number of the
2747 * GDB now displays the ID and name of the thread that hit a breakpoint
2748 or received a signal, if your program is multi-threaded. For
2751 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2752 Thread 1 "main" received signal SIGINT, Interrupt.
2754 * Record btrace now supports non-stop mode.
2756 * Support for tracepoints on aarch64-linux was added in GDBserver.
2758 * The 'record instruction-history' command now indicates speculative execution
2759 when using the Intel Processor Trace recording format.
2761 * GDB now allows users to specify explicit locations, bypassing
2762 the linespec parser. This feature is also available to GDB/MI
2765 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2766 GDB now is able to debug both AArch64 applications and ARM applications
2769 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2770 including JIT compiling fast tracepoint's conditional expression bytecode
2773 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2775 * "info threads", "info inferiors", "info display", "info checkpoints"
2776 and "maint info program-spaces" now list the corresponding items in
2777 ascending ID order, for consistency with all other "info" commands.
2779 * In Ada, the overloads selection menu has been enhanced to display the
2780 parameter types and the return types for the matching overloaded subprograms.
2784 maint set target-non-stop (on|off|auto)
2785 maint show target-non-stop
2786 Control whether GDB targets always operate in non-stop mode even if
2787 "set non-stop" is "off". The default is "auto", meaning non-stop
2788 mode is enabled if supported by the target.
2790 maint set bfd-sharing
2791 maint show bfd-sharing
2792 Control the reuse of bfd objects.
2795 show debug bfd-cache
2796 Control display of debugging info regarding bfd caching.
2800 Control display of debugging info regarding FreeBSD threads.
2802 set remote multiprocess-extensions-packet
2803 show remote multiprocess-extensions-packet
2804 Set/show the use of the remote protocol multiprocess extensions.
2806 set remote thread-events
2807 show remote thread-events
2808 Set/show the use of thread create/exit events.
2810 set ada print-signatures on|off
2811 show ada print-signatures"
2812 Control whether parameter types and return types are displayed in overloads
2813 selection menus. It is activated (@code{on}) by default.
2817 Controls the maximum size of memory, in bytes, that GDB will
2818 allocate for value contents. Prevents incorrect programs from
2819 causing GDB to allocate overly large buffers. Default is 64k.
2821 * The "disassemble" command accepts a new modifier: /s.
2822 It prints mixed source+disassembly like /m with two differences:
2823 - disassembled instructions are now printed in program order, and
2824 - and source for all relevant files is now printed.
2825 The "/m" option is now considered deprecated: its "source-centric"
2826 output hasn't proved useful in practice.
2828 * The "record instruction-history" command accepts a new modifier: /s.
2829 It behaves exactly like /m and prints mixed source+disassembly.
2831 * The "set scheduler-locking" command supports a new mode "replay".
2832 It behaves like "off" in record mode and like "on" in replay mode.
2834 * Support for various ROM monitors has been removed:
2836 target dbug dBUG ROM monitor for Motorola ColdFire
2837 target picobug Motorola picobug monitor
2838 target dink32 DINK32 ROM monitor for PowerPC
2839 target m32r Renesas M32R/D ROM monitor
2840 target mon2000 mon2000 ROM monitor
2841 target ppcbug PPCBUG ROM monitor for PowerPC
2843 * Support for reading/writing memory and extracting values on architectures
2844 whose memory is addressable in units of any integral multiple of 8 bits.
2847 Allows to break when an Ada exception is handled.
2849 * New remote packets
2852 Indicates that an exec system call was executed.
2854 exec-events feature in qSupported
2855 The qSupported packet allows GDB to request support for exec
2856 events using the new 'gdbfeature' exec-event, and the qSupported
2857 response can contain the corresponding 'stubfeature'. Set and
2858 show commands can be used to display whether these features are enabled.
2861 Equivalent to interrupting with the ^C character, but works in
2864 thread created stop reason (T05 create:...)
2865 Indicates that the thread was just created and is stopped at entry.
2867 thread exit stop reply (w exitcode;tid)
2868 Indicates that the thread has terminated.
2871 Enables/disables thread create and exit event reporting. For
2872 example, this is used in non-stop mode when GDB stops a set of
2873 threads and synchronously waits for the their corresponding stop
2874 replies. Without exit events, if one of the threads exits, GDB
2875 would hang forever not knowing that it should no longer expect a
2876 stop for that same thread.
2879 Indicates that there are no resumed threads left in the target (all
2880 threads are stopped). The remote stub reports support for this stop
2881 reply to GDB's qSupported query.
2884 Enables/disables catching syscalls from the inferior process.
2885 The remote stub reports support for this packet to GDB's qSupported query.
2887 syscall_entry stop reason
2888 Indicates that a syscall was just called.
2890 syscall_return stop reason
2891 Indicates that a syscall just returned.
2893 * Extended-remote exec events
2895 ** GDB now has support for exec events on extended-remote Linux targets.
2896 For such targets with Linux kernels 2.5.46 and later, this enables
2897 follow-exec-mode and exec catchpoints.
2899 set remote exec-event-feature-packet
2900 show remote exec-event-feature-packet
2901 Set/show the use of the remote exec event feature.
2903 * Thread names in remote protocol
2905 The reply to qXfer:threads:read may now include a name attribute for each
2908 * Target remote mode fork and exec events
2910 ** GDB now has support for fork and exec events on target remote mode
2911 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2912 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2913 fork and exec catchpoints.
2915 * Remote syscall events
2917 ** GDB now has support for catch syscall on remote Linux targets,
2918 currently enabled on x86/x86_64 architectures.
2920 set remote catch-syscall-packet
2921 show remote catch-syscall-packet
2922 Set/show the use of the remote catch syscall feature.
2926 ** The -var-set-format command now accepts the zero-hexadecimal
2927 format. It outputs data in hexadecimal format with zero-padding on the
2932 ** gdb.InferiorThread objects have a new attribute "global_num",
2933 which refers to the thread's global thread ID. The existing
2934 "num" attribute now refers to the thread's per-inferior number.
2935 See "Per-inferior thread numbers" above.
2936 ** gdb.InferiorThread objects have a new attribute "inferior", which
2937 is the Inferior object the thread belongs to.
2939 *** Changes in GDB 7.10
2941 * Support for process record-replay and reverse debugging on aarch64*-linux*
2942 targets has been added. GDB now supports recording of A64 instruction set
2943 including advance SIMD instructions.
2945 * Support for Sun's version of the "stabs" debug file format has been removed.
2947 * GDB now honors the content of the file /proc/PID/coredump_filter
2948 (PID is the process ID) on GNU/Linux systems. This file can be used
2949 to specify the types of memory mappings that will be included in a
2950 corefile. For more information, please refer to the manual page of
2951 "core(5)". GDB also has a new command: "set use-coredump-filter
2952 on|off". It allows to set whether GDB will read the content of the
2953 /proc/PID/coredump_filter file when generating a corefile.
2955 * The "info os" command on GNU/Linux can now display information on
2957 "info os cpus" Listing of all cpus/cores on the system
2959 * GDB has two new commands: "set serial parity odd|even|none" and
2960 "show serial parity". These allows to set or show parity for the
2963 * The "info source" command now displays the producer string if it was
2964 present in the debug info. This typically includes the compiler version
2965 and may include things like its command line arguments.
2967 * The "info dll", an alias of the "info sharedlibrary" command,
2968 is now available on all platforms.
2970 * Directory names supplied to the "set sysroot" commands may be
2971 prefixed with "target:" to tell GDB to access shared libraries from
2972 the target system, be it local or remote. This replaces the prefix
2973 "remote:". The default sysroot has been changed from "" to
2974 "target:". "remote:" is automatically converted to "target:" for
2975 backward compatibility.
2977 * The system root specified by "set sysroot" will be prepended to the
2978 filename of the main executable (if reported to GDB as absolute by
2979 the operating system) when starting processes remotely, and when
2980 attaching to already-running local or remote processes.
2982 * GDB now supports automatic location and retrieval of executable
2983 files from remote targets. Remote debugging can now be initiated
2984 using only a "target remote" or "target extended-remote" command
2985 (no "set sysroot" or "file" commands are required). See "New remote
2988 * The "dump" command now supports verilog hex format.
2990 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2992 * On GNU/Linux, GDB and gdbserver are now able to access executable
2993 and shared library files without a "set sysroot" command when
2994 attaching to processes running in different mount namespaces from
2995 the debugger. This makes it possible to attach to processes in
2996 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2997 See "New remote packets" below.
2999 * The "tui reg" command now provides completion for all of the
3000 available register groups, including target specific groups.
3002 * The HISTSIZE environment variable is no longer read when determining
3003 the size of GDB's command history. GDB now instead reads the dedicated
3004 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3005 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3010 ** Memory ports can now be unbuffered.
3014 ** gdb.Objfile objects have a new attribute "username",
3015 which is the name of the objfile as specified by the user,
3016 without, for example, resolving symlinks.
3017 ** You can now write frame unwinders in Python.
3018 ** gdb.Type objects have a new method "optimized_out",
3019 returning optimized out gdb.Value instance of this type.
3020 ** gdb.Value objects have new methods "reference_value" and
3021 "const_value" which return a reference to the value and a
3022 "const" version of the value respectively.
3026 maint print symbol-cache
3027 Print the contents of the symbol cache.
3029 maint print symbol-cache-statistics
3030 Print statistics of symbol cache usage.
3032 maint flush-symbol-cache
3033 Flush the contents of the symbol cache.
3037 Start branch trace recording using Branch Trace Store (BTS) format.
3040 Evaluate expression by using the compiler and print result.
3044 Explicit commands for enabling and disabling tui mode.
3047 set mpx bound on i386 and amd64
3048 Support for bound table investigation on Intel MPX enabled applications.
3052 Start branch trace recording using Intel Processor Trace format.
3055 Print information about branch tracing internals.
3057 maint btrace packet-history
3058 Print the raw branch tracing data.
3060 maint btrace clear-packet-history
3061 Discard the stored raw branch tracing data.
3064 Discard all branch tracing data. It will be fetched and processed
3065 anew by the next "record" command.
3070 Renamed from "set debug dwarf2-die".
3071 show debug dwarf-die
3072 Renamed from "show debug dwarf2-die".
3074 set debug dwarf-read
3075 Renamed from "set debug dwarf2-read".
3076 show debug dwarf-read
3077 Renamed from "show debug dwarf2-read".
3079 maint set dwarf always-disassemble
3080 Renamed from "maint set dwarf2 always-disassemble".
3081 maint show dwarf always-disassemble
3082 Renamed from "maint show dwarf2 always-disassemble".
3084 maint set dwarf max-cache-age
3085 Renamed from "maint set dwarf2 max-cache-age".
3086 maint show dwarf max-cache-age
3087 Renamed from "maint show dwarf2 max-cache-age".
3089 set debug dwarf-line
3090 show debug dwarf-line
3091 Control display of debugging info regarding DWARF line processing.
3094 show max-completions
3095 Set the maximum number of candidates to be considered during
3096 completion. The default value is 200. This limit allows GDB
3097 to avoid generating large completion lists, the computation of
3098 which can cause the debugger to become temporarily unresponsive.
3100 set history remove-duplicates
3101 show history remove-duplicates
3102 Control the removal of duplicate history entries.
3104 maint set symbol-cache-size
3105 maint show symbol-cache-size
3106 Control the size of the symbol cache.
3108 set|show record btrace bts buffer-size
3109 Set and show the size of the ring buffer used for branch tracing in
3111 The obtained size may differ from the requested size. Use "info
3112 record" to see the obtained buffer size.
3114 set debug linux-namespaces
3115 show debug linux-namespaces
3116 Control display of debugging info regarding Linux namespaces.
3118 set|show record btrace pt buffer-size
3119 Set and show the size of the ring buffer used for branch tracing in
3120 Intel Processor Trace format.
3121 The obtained size may differ from the requested size. Use "info
3122 record" to see the obtained buffer size.
3124 maint set|show btrace pt skip-pad
3125 Set and show whether PAD packets are skipped when computing the
3128 * The command 'thread apply all' can now support new option '-ascending'
3129 to call its specified command for all threads in ascending order.
3131 * Python/Guile scripting
3133 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3134 special section named `.debug_gdb_scripts'.
3136 * New remote packets
3138 qXfer:btrace-conf:read
3139 Return the branch trace configuration for the current thread.
3141 Qbtrace-conf:bts:size
3142 Set the requested ring buffer size for branch tracing in BTS format.
3145 Enable Intel Processor Trace-based branch tracing for the current
3146 process. The remote stub reports support for this packet to GDB's
3149 Qbtrace-conf:pt:size
3150 Set the requested ring buffer size for branch tracing in Intel Processor
3154 Indicates a memory breakpoint instruction was executed, irrespective
3155 of whether it was GDB that planted the breakpoint or the breakpoint
3156 is hardcoded in the program. This is required for correct non-stop
3160 Indicates the target stopped for a hardware breakpoint. This is
3161 required for correct non-stop mode operation.
3164 Return information about files on the remote system.
3166 qXfer:exec-file:read
3167 Return the full absolute name of the file that was executed to
3168 create a process running on the remote system.
3171 Select the filesystem on which vFile: operations with filename
3172 arguments will operate. This is required for GDB to be able to
3173 access files on remote targets where the remote stub does not
3174 share a common filesystem with the inferior(s).
3177 Indicates that a fork system call was executed.
3180 Indicates that a vfork system call was executed.
3182 vforkdone stop reason
3183 Indicates that a vfork child of the specified process has executed
3184 an exec or exit, allowing the vfork parent to resume execution.
3186 fork-events and vfork-events features in qSupported
3187 The qSupported packet allows GDB to request support for fork and
3188 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3189 and the qSupported response can contain the corresponding
3190 'stubfeatures'. Set and show commands can be used to display
3191 whether these features are enabled.
3193 * Extended-remote fork events
3195 ** GDB now has support for fork events on extended-remote Linux
3196 targets. For targets with Linux kernels 2.5.60 and later, this
3197 enables follow-fork-mode and detach-on-fork for both fork and
3198 vfork, as well as fork and vfork catchpoints.
3200 * The info record command now shows the recording format and the
3201 branch tracing configuration for the current thread when using
3202 the btrace record target.
3203 For the BTS format, it shows the ring buffer size.
3205 * GDB now has support for DTrace USDT (Userland Static Defined
3206 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3208 * GDB now supports access to vector registers on S/390 GNU/Linux
3211 * Removed command line options
3213 -xdb HP-UX XDB compatibility mode.
3215 * Removed targets and native configurations
3217 HP/PA running HP-UX hppa*-*-hpux*
3218 Itanium running HP-UX ia64-*-hpux*
3220 * New configure options
3223 This configure option allows the user to build GDB with support for
3224 Intel Processor Trace (default: auto). This requires libipt.
3226 --with-libipt-prefix=PATH
3227 Specify the path to the version of libipt that GDB should use.
3228 $PATH/include should contain the intel-pt.h header and
3229 $PATH/lib should contain the libipt.so library.
3231 *** Changes in GDB 7.9.1
3235 ** Xmethods can now specify a result type.
3237 *** Changes in GDB 7.9
3239 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3243 ** You can now access frame registers from Python scripts.
3244 ** New attribute 'producer' for gdb.Symtab objects.
3245 ** gdb.Objfile objects have a new attribute "progspace",
3246 which is the gdb.Progspace object of the containing program space.
3247 ** gdb.Objfile objects have a new attribute "owner".
3248 ** gdb.Objfile objects have a new attribute "build_id",
3249 which is the build ID generated when the file was built.
3250 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3251 ** A new event "gdb.clear_objfiles" has been added, triggered when
3252 selecting a new file to debug.
3253 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3254 ** New function gdb.lookup_objfile.
3256 New events which are triggered when GDB modifies the state of the
3259 ** gdb.events.inferior_call_pre: Function call is about to be made.
3260 ** gdb.events.inferior_call_post: Function call has just been made.
3261 ** gdb.events.memory_changed: A memory location has been altered.
3262 ** gdb.events.register_changed: A register has been altered.
3264 * New Python-based convenience functions:
3266 ** $_caller_is(name [, number_of_frames])
3267 ** $_caller_matches(regexp [, number_of_frames])
3268 ** $_any_caller_is(name [, number_of_frames])
3269 ** $_any_caller_matches(regexp [, number_of_frames])
3271 * GDB now supports the compilation and injection of source code into
3272 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3273 to compile the source code to object code, and if successful, inject
3274 and execute that code within the current context of the inferior.
3275 Currently the C language is supported. The commands used to
3276 interface with this new feature are:
3278 compile code [-raw|-r] [--] [source code]
3279 compile file [-raw|-r] filename
3283 demangle [-l language] [--] name
3284 Demangle "name" in the specified language, or the current language
3285 if elided. This command is renamed from the "maint demangle" command.
3286 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3287 as "maint demangler-warning".
3289 queue-signal signal-name-or-number
3290 Queue a signal to be delivered to the thread when it is resumed.
3292 add-auto-load-scripts-directory directory
3293 Add entries to the list of directories from which to load auto-loaded
3296 maint print user-registers
3297 List all currently available "user" registers.
3299 compile code [-r|-raw] [--] [source code]
3300 Compile, inject, and execute in the inferior the executable object
3301 code produced by compiling the provided source code.
3303 compile file [-r|-raw] filename
3304 Compile and inject into the inferior the executable object code
3305 produced by compiling the source code stored in the filename
3308 * On resume, GDB now always passes the signal the program had stopped
3309 for to the thread the signal was sent to, even if the user changed
3310 threads before resuming. Previously GDB would often (but not
3311 always) deliver the signal to the thread that happens to be current
3314 * Conversely, the "signal" command now consistently delivers the
3315 requested signal to the current thread. GDB now asks for
3316 confirmation if the program had stopped for a signal and the user
3317 switched threads meanwhile.
3319 * "breakpoint always-inserted" modes "off" and "auto" merged.
3321 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3322 won't remove breakpoints from the target until all threads stop,
3323 even in non-stop mode. The "auto" mode has been removed, and "off"
3324 is now the default mode.
3328 set debug symbol-lookup
3329 show debug symbol-lookup
3330 Control display of debugging info regarding symbol lookup.
3334 ** The -list-thread-groups command outputs an exit-code field for
3335 inferiors that have exited.
3339 MIPS SDE mips*-sde*-elf*
3343 Support for these obsolete configurations has been removed.
3345 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3346 SGI Irix-5.x mips-*-irix5*
3347 SGI Irix-6.x mips-*-irix6*
3348 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3349 VAX running Ultrix vax-*-ultrix*
3351 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3352 and "assf"), have been removed. Use the "sharedlibrary" command, or
3353 its alias "share", instead.
3355 *** Changes in GDB 7.8
3357 * New command line options
3360 This is an alias for the --data-directory option.
3362 * GDB supports printing and modifying of variable length automatic arrays
3363 as specified in ISO C99.
3365 * The ARM simulator now supports instruction level tracing
3366 with or without disassembly.
3370 GDB now has support for scripting using Guile. Whether this is
3371 available is determined at configure time.
3372 Guile version 2.0 or greater is required.
3373 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3375 * New commands (for set/show, see "New options" below)
3379 Invoke CODE by passing it to the Guile interpreter.
3383 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3385 info auto-load guile-scripts [regexp]
3386 Print the list of automatically loaded Guile scripts.
3388 * The source command is now capable of sourcing Guile scripts.
3389 This feature is dependent on the debugger being built with Guile support.
3393 set print symbol-loading (off|brief|full)
3394 show print symbol-loading
3395 Control whether to print informational messages when loading symbol
3396 information for a file. The default is "full", but when debugging
3397 programs with large numbers of shared libraries the amount of output
3398 becomes less useful.
3400 set guile print-stack (none|message|full)
3401 show guile print-stack
3402 Show a stack trace when an error is encountered in a Guile script.
3404 set auto-load guile-scripts (on|off)
3405 show auto-load guile-scripts
3406 Control auto-loading of Guile script files.
3408 maint ada set ignore-descriptive-types (on|off)
3409 maint ada show ignore-descriptive-types
3410 Control whether the debugger should ignore descriptive types in Ada
3411 programs. The default is not to ignore the descriptive types. See
3412 the user manual for more details on descriptive types and the intended
3413 usage of this option.
3415 set auto-connect-native-target
3417 Control whether GDB is allowed to automatically connect to the
3418 native target for the run, attach, etc. commands when not connected
3419 to any target yet. See also "target native" below.
3421 set record btrace replay-memory-access (read-only|read-write)
3422 show record btrace replay-memory-access
3423 Control what memory accesses are allowed during replay.
3425 maint set target-async (on|off)
3426 maint show target-async
3427 This controls whether GDB targets operate in synchronous or
3428 asynchronous mode. Normally the default is asynchronous, if it is
3429 available; but this can be changed to more easily debug problems
3430 occurring only in synchronous mode.
3432 set mi-async (on|off)
3434 Control whether MI asynchronous mode is preferred. This supersedes
3435 "set target-async" of previous GDB versions.
3437 * "set target-async" is deprecated as a CLI option and is now an alias
3438 for "set mi-async" (only puts MI into async mode).
3440 * Background execution commands (e.g., "c&", "s&", etc.) are now
3441 possible ``out of the box'' if the target supports them. Previously
3442 the user would need to explicitly enable the possibility with the
3443 "set target-async on" command.
3445 * New features in the GDB remote stub, GDBserver
3447 ** New option --debug-format=option1[,option2,...] allows one to add
3448 additional text to each output. At present only timestamps
3449 are supported: --debug-format=timestamps.
3450 Timestamps can also be turned on with the
3451 "monitor set debug-format timestamps" command from GDB.
3453 * The 'record instruction-history' command now starts counting instructions
3454 at one. This also affects the instruction ranges reported by the
3455 'record function-call-history' command when given the /i modifier.
3457 * The command 'record function-call-history' supports a new modifier '/c' to
3458 indent the function names based on their call stack depth.
3459 The fields for the '/i' and '/l' modifier have been reordered.
3460 The source line range is now prefixed with 'at'.
3461 The instruction range is now prefixed with 'inst'.
3462 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3463 "record instruction-history" and "list" commands.
3465 * The ranges given as arguments to the 'record function-call-history' and
3466 'record instruction-history' commands are now inclusive.
3468 * The btrace record target now supports the 'record goto' command.
3469 For locations inside the execution trace, the back trace is computed
3470 based on the information stored in the execution trace.
3472 * The btrace record target supports limited reverse execution and replay.
3473 The target does not record data and therefore does not allow reading
3474 memory or registers.
3476 * The "catch syscall" command now works on s390*-linux* targets.
3478 * The "compare-sections" command is no longer specific to target
3479 remote. It now works with all targets.
3481 * All native targets are now consistently called "native".
3482 Consequently, the "target child", "target GNU", "target djgpp",
3483 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3484 commands have been replaced with "target native". The QNX/NTO port
3485 leaves the "procfs" target in place and adds a "native" target for
3486 consistency with other ports. The impact on users should be minimal
3487 as these commands previously either throwed an error, or were
3488 no-ops. The target's name is visible in the output of the following
3489 commands: "help target", "info target", "info files", "maint print
3492 * The "target native" command now connects to the native target. This
3493 can be used to launch native programs even when "set
3494 auto-connect-native-target" is set to off.
3496 * GDB now supports access to Intel MPX registers on GNU/Linux.
3498 * Support for Intel AVX-512 registers on GNU/Linux.
3499 Support displaying and modifying Intel AVX-512 registers
3500 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3502 * New remote packets
3504 qXfer:btrace:read's annex
3505 The qXfer:btrace:read packet supports a new annex 'delta' to read
3506 branch trace incrementally.
3510 ** Valid Python operations on gdb.Value objects representing
3511 structs/classes invoke the corresponding overloaded operators if
3513 ** New `Xmethods' feature in the Python API. Xmethods are
3514 additional methods or replacements for existing methods of a C++
3515 class. This feature is useful for those cases where a method
3516 defined in C++ source code could be inlined or optimized out by
3517 the compiler, making it unavailable to GDB.
3520 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3522 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3523 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3524 its alias "share", instead.
3526 * The commands "set remotebaud" and "show remotebaud" are no longer
3527 supported. Use "set serial baud" and "show serial baud" (respectively)
3532 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3533 target-async". The latter is left as a deprecated alias of the
3534 former for backward compatibility. If the target supports it,
3535 CLI background execution commands are now always possible by
3536 default, independently of whether the frontend stated a
3537 preference for asynchronous execution with "-gdb-set mi-async".
3538 Previously "-gdb-set target-async off" affected both MI execution
3539 commands and CLI execution commands.
3541 *** Changes in GDB 7.7
3543 * Improved support for process record-replay and reverse debugging on
3544 arm*-linux* targets. Support for thumb32 and syscall instruction
3545 recording has been added.
3547 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3549 * GDB now supports Fission DWP file format version 2.
3550 http://gcc.gnu.org/wiki/DebugFission
3552 * New convenience function "$_isvoid", to check whether an expression
3553 is void. A void expression is an expression where the type of the
3554 result is "void". For example, some convenience variables may be
3555 "void" when evaluated (e.g., "$_exitcode" before the execution of
3556 the program being debugged; or an undefined convenience variable).
3557 Another example, when calling a function whose return type is
3560 * The "maintenance print objfiles" command now takes an optional regexp.
3562 * The "catch syscall" command now works on arm*-linux* targets.
3564 * GDB now consistently shows "<not saved>" when printing values of
3565 registers the debug info indicates have not been saved in the frame
3566 and there's nowhere to retrieve them from
3567 (callee-saved/call-clobbered registers):
3572 (gdb) info registers rax
3575 Before, the former would print "<optimized out>", and the latter
3576 "*value not available*".
3578 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3583 ** Frame filters and frame decorators have been added.
3584 ** Temporary breakpoints are now supported.
3585 ** Line tables representation has been added.
3586 ** New attribute 'parent_type' for gdb.Field objects.
3587 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3588 ** New attribute 'name' for gdb.Type objects.
3592 Nios II ELF nios2*-*-elf
3593 Nios II GNU/Linux nios2*-*-linux
3594 Texas Instruments MSP430 msp430*-*-elf
3596 * Removed native configurations
3598 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3599 been removed. ELF variants of these configurations are kept supported.
3601 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3602 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3603 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3604 i[34567]86-*-openbsd3.[0-3]
3605 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3606 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3607 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3611 Like "catch throw", but catches a re-thrown exception.
3612 maint check-psymtabs
3613 Renamed from old "maint check-symtabs".
3615 Perform consistency checks on symtabs.
3616 maint expand-symtabs
3617 Expand symtabs matching an optional regexp.
3620 Display the details of GDB configure-time options.
3622 maint set|show per-command
3623 maint set|show per-command space
3624 maint set|show per-command time
3625 maint set|show per-command symtab
3626 Enable display of per-command gdb resource usage.
3628 remove-symbol-file FILENAME
3629 remove-symbol-file -a ADDRESS
3630 Remove a symbol file added via add-symbol-file. The file to remove
3631 can be identified by its filename or by an address that lies within
3632 the boundaries of this symbol file in memory.
3635 info exceptions REGEXP
3636 Display the list of Ada exceptions defined in the program being
3637 debugged. If provided, only the exceptions whose names match REGEXP
3642 set debug symfile off|on
3644 Control display of debugging info regarding reading symbol files and
3645 symbol tables within those files
3647 set print raw frame-arguments
3648 show print raw frame-arguments
3649 Set/show whether to print frame arguments in raw mode,
3650 disregarding any defined pretty-printers.
3652 set remote trace-status-packet
3653 show remote trace-status-packet
3654 Set/show the use of remote protocol qTStatus packet.
3658 Control display of debugging messages related to Nios II targets.
3662 Control whether target-assisted range stepping is enabled.
3664 set startup-with-shell
3665 show startup-with-shell
3666 Specifies whether Unix child processes are started via a shell or
3671 Use the target memory cache for accesses to the code segment. This
3672 improves performance of remote debugging (particularly disassembly).
3674 * You can now use a literal value 'unlimited' for options that
3675 interpret 0 or -1 as meaning "unlimited". E.g., "set
3676 trace-buffer-size unlimited" is now an alias for "set
3677 trace-buffer-size -1" and "set height unlimited" is now an alias for
3680 * The "set debug symtab-create" debugging option of GDB has been changed to
3681 accept a verbosity level. 0 means "off", 1 provides basic debugging
3682 output, and values of 2 or greater provides more verbose output.
3684 * New command-line options
3686 Display the details of GDB configure-time options.
3688 * The command 'tsave' can now support new option '-ctf' to save trace
3689 buffer in Common Trace Format.
3691 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3694 * GDB now implements the C++ 'typeid' operator.
3696 * The new convenience variable $_exception holds the exception being
3697 thrown or caught at an exception-related catchpoint.
3699 * The exception-related catchpoints, like "catch throw", now accept a
3700 regular expression which can be used to filter exceptions by type.
3702 * The new convenience variable $_exitsignal is automatically set to
3703 the terminating signal number when the program being debugged dies
3704 due to an uncaught signal.
3708 ** All MI commands now accept an optional "--language" option.
3709 Support for this feature can be verified by using the "-list-features"
3710 command, which should contain "language-option".
3712 ** The new command -info-gdb-mi-command allows the user to determine
3713 whether a GDB/MI command is supported or not.
3715 ** The "^error" result record returned when trying to execute an undefined
3716 GDB/MI command now provides a variable named "code" whose content is the
3717 "undefined-command" error code. Support for this feature can be verified
3718 by using the "-list-features" command, which should contain
3719 "undefined-command-error-code".
3721 ** The -trace-save MI command can optionally save trace buffer in Common
3724 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3726 ** The command -data-list-register-values now accepts an optional
3727 "--skip-unavailable" option. When used, only the available registers
3730 ** The new command -trace-frame-collected dumps collected variables,
3731 computed expressions, tvars, memory and registers in a traceframe.
3733 ** The commands -stack-list-locals, -stack-list-arguments and
3734 -stack-list-variables now accept an option "--skip-unavailable".
3735 When used, only the available locals or arguments are displayed.
3737 ** The -exec-run command now accepts an optional "--start" option.
3738 When used, the command follows the same semantics as the "start"
3739 command, stopping the program's execution at the start of its
3740 main subprogram. Support for this feature can be verified using
3741 the "-list-features" command, which should contain
3742 "exec-run-start-option".
3744 ** The new commands -catch-assert and -catch-exceptions insert
3745 catchpoints stopping the program when Ada exceptions are raised.
3747 ** The new command -info-ada-exceptions provides the equivalent of
3748 the new "info exceptions" command.
3750 * New system-wide configuration scripts
3751 A GDB installation now provides scripts suitable for use as system-wide
3752 configuration scripts for the following systems:
3756 * GDB now supports target-assigned range stepping with remote targets.
3757 This improves the performance of stepping source lines by reducing
3758 the number of control packets from/to GDB. See "New remote packets"
3761 * GDB now understands the element 'tvar' in the XML traceframe info.
3762 It has the id of the collected trace state variables.
3764 * On S/390 targets that provide the transactional-execution feature,
3765 the program interruption transaction diagnostic block (TDB) is now
3766 represented as a number of additional "registers" in GDB.
3768 * New remote packets
3772 The vCont packet supports a new 'r' action, that tells the remote
3773 stub to step through an address range itself, without GDB
3774 involvemement at each single-step.
3776 qXfer:libraries-svr4:read's annex
3777 The previously unused annex of the qXfer:libraries-svr4:read packet
3778 is now used to support passing an argument list. The remote stub
3779 reports support for this argument list to GDB's qSupported query.
3780 The defined arguments are "start" and "prev", used to reduce work
3781 necessary for library list updating, resulting in significant
3784 * New features in the GDB remote stub, GDBserver
3786 ** GDBserver now supports target-assisted range stepping. Currently
3787 enabled on x86/x86_64 GNU/Linux targets.
3789 ** GDBserver now adds element 'tvar' in the XML in the reply to
3790 'qXfer:traceframe-info:read'. It has the id of the collected
3791 trace state variables.
3793 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3796 * New 'z' formatter for printing and examining memory, this displays the
3797 value as hexadecimal zero padded on the left to the size of the type.
3799 * GDB can now use Windows x64 unwinding data.
3801 * The "set remotebaud" command has been replaced by "set serial baud".
3802 Similarly, "show remotebaud" has been replaced by "show serial baud".
3803 The "set remotebaud" and "show remotebaud" commands are still available
3804 to provide backward compatibility with older versions of GDB.
3806 *** Changes in GDB 7.6
3808 * Target record has been renamed to record-full.
3809 Record/replay is now enabled with the "record full" command.
3810 This also affects settings that are associated with full record/replay
3811 that have been moved from "set/show record" to "set/show record full":
3813 set|show record full insn-number-max
3814 set|show record full stop-at-limit
3815 set|show record full memory-query
3817 * A new record target "record-btrace" has been added. The new target
3818 uses hardware support to record the control-flow of a process. It
3819 does not support replaying the execution, but it implements the
3820 below new commands for investigating the recorded execution log.
3821 This new recording method can be enabled using:
3825 The "record-btrace" target is only available on Intel Atom processors
3826 and requires a Linux kernel 2.6.32 or later.
3828 * Two new commands have been added for record/replay to give information
3829 about the recorded execution without having to replay the execution.
3830 The commands are only supported by "record btrace".
3832 record instruction-history prints the execution history at
3833 instruction granularity
3835 record function-call-history prints the execution history at
3836 function granularity
3838 * New native configurations
3840 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3841 FreeBSD/powerpc powerpc*-*-freebsd
3842 x86_64/Cygwin x86_64-*-cygwin*
3843 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3847 ARM AArch64 aarch64*-*-elf
3848 ARM AArch64 GNU/Linux aarch64*-*-linux
3849 Lynx 178 PowerPC powerpc-*-lynx*178
3850 x86_64/Cygwin x86_64-*-cygwin*
3851 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3853 * If the configured location of system.gdbinit file (as given by the
3854 --with-system-gdbinit option at configure time) is in the
3855 data-directory (as specified by --with-gdb-datadir at configure
3856 time) or in one of its subdirectories, then GDB will look for the
3857 system-wide init file in the directory specified by the
3858 --data-directory command-line option.
3860 * New command line options:
3862 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3863 other initialization files, unlike -nx which disables all of them.
3865 * Removed command line options
3867 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3870 * The 'ptype' and 'whatis' commands now accept an argument to control
3873 * 'info proc' now works on some core files.
3877 ** Vectors can be created with gdb.Type.vector.
3879 ** Python's atexit.register now works in GDB.
3881 ** Types can be pretty-printed via a Python API.
3883 ** Python 3 is now supported (in addition to Python 2.4 or later)
3885 ** New class gdb.Architecture exposes GDB's internal representation
3886 of architecture in the Python API.
3888 ** New method Frame.architecture returns the gdb.Architecture object
3889 corresponding to the frame's architecture.
3891 * New Python-based convenience functions:
3893 ** $_memeq(buf1, buf2, length)
3894 ** $_streq(str1, str2)
3896 ** $_regex(str, regex)
3898 * The 'cd' command now defaults to using '~' (the home directory) if not
3901 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3902 default for GCC since November 2000.
3904 * The command 'forward-search' can now be abbreviated as 'fo'.
3906 * The command 'info tracepoints' can now display 'installed on target'
3907 or 'not installed on target' for each non-pending location of tracepoint.
3909 * New configure options
3911 --enable-libmcheck/--disable-libmcheck
3912 By default, development versions are built with -lmcheck on hosts
3913 that support it, in order to help track memory corruption issues.
3914 Release versions, on the other hand, are built without -lmcheck
3915 by default. The --enable-libmcheck/--disable-libmcheck configure
3916 options allow the user to override that default.
3917 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3918 This configure option allows the user to build GDB with
3919 libbabeltrace using which GDB can read Common Trace Format data.
3921 * New commands (for set/show, see "New options" below)
3924 Catch signals. This is similar to "handle", but allows commands and
3925 conditions to be attached.
3928 List the BFDs known to GDB.
3930 python-interactive [command]
3932 Start a Python interactive prompt, or evaluate the optional command
3933 and print the result of expressions.
3936 "py" is a new alias for "python".
3938 enable type-printer [name]...
3939 disable type-printer [name]...
3940 Enable or disable type printers.
3944 ** For the Renesas Super-H architecture, the "regs" command has been removed
3945 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3950 set print type methods (on|off)
3951 show print type methods
3952 Control whether method declarations are displayed by "ptype".
3953 The default is to show them.
3955 set print type typedefs (on|off)
3956 show print type typedefs
3957 Control whether typedef definitions are displayed by "ptype".
3958 The default is to show them.
3960 set filename-display basename|relative|absolute
3961 show filename-display
3962 Control the way in which filenames is displayed.
3963 The default is "relative", which preserves previous behavior.
3965 set trace-buffer-size
3966 show trace-buffer-size
3967 Request target to change the size of trace buffer.
3969 set remote trace-buffer-size-packet auto|on|off
3970 show remote trace-buffer-size-packet
3971 Control the use of the remote protocol `QTBuffer:size' packet.
3975 Control display of debugging messages related to ARM AArch64.
3978 set debug coff-pe-read
3979 show debug coff-pe-read
3980 Control display of debugging messages related to reading of COFF/PE
3985 Control display of debugging messages related to Mach-O symbols
3988 set debug notification
3989 show debug notification
3990 Control display of debugging info for async remote notification.
3994 ** Command parameter changes are now notified using new async record
3995 "=cmd-param-changed".
3996 ** Trace frame changes caused by command "tfind" are now notified using
3997 new async record "=traceframe-changed".
3998 ** The creation, deletion and modification of trace state variables
3999 are now notified using new async records "=tsv-created",
4000 "=tsv-deleted" and "=tsv-modified".
4001 ** The start and stop of process record are now notified using new
4002 async record "=record-started" and "=record-stopped".
4003 ** Memory changes are now notified using new async record
4005 ** The data-disassemble command response will include a "fullname" field
4006 containing the absolute file name when source has been requested.
4007 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4008 command, to allow pattern filling of memory areas.
4009 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4010 library load/unload events.
4011 ** The response to breakpoint commands and breakpoint async records
4012 includes an "installed" field containing a boolean state about each
4013 non-pending tracepoint location is whether installed on target or not.
4014 ** Output of the "-trace-status" command includes a "trace-file" field
4015 containing the name of the trace file being examined. This field is
4016 optional, and only present when examining a trace file.
4017 ** The "fullname" field is now always present along with the "file" field,
4018 even if the file cannot be found by GDB.
4020 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4021 You must have the LZMA library available when configuring GDB for this
4022 feature to be enabled. For more information, see:
4023 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4025 * New remote packets
4028 Set the size of trace buffer. The remote stub reports support for this
4029 packet to gdb's qSupported query.
4032 Enable Branch Trace Store (BTS)-based branch tracing for the current
4033 thread. The remote stub reports support for this packet to gdb's
4037 Disable branch tracing for the current thread. The remote stub reports
4038 support for this packet to gdb's qSupported query.
4041 Read the traced branches for the current thread. The remote stub
4042 reports support for this packet to gdb's qSupported query.
4044 *** Changes in GDB 7.5
4046 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4047 for more x32 ABI info.
4049 * GDB now supports access to MIPS DSP registers on Linux targets.
4051 * GDB now supports debugging microMIPS binaries.
4053 * The "info os" command on GNU/Linux can now display information on
4054 several new classes of objects managed by the operating system:
4055 "info os procgroups" lists process groups
4056 "info os files" lists file descriptors
4057 "info os sockets" lists internet-domain sockets
4058 "info os shm" lists shared-memory regions
4059 "info os semaphores" lists semaphores
4060 "info os msg" lists message queues
4061 "info os modules" lists loaded kernel modules
4063 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4064 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4065 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4066 options and inspect the probe arguments using the new $_probe_arg family
4067 of convenience variables. You can obtain more information about SystemTap
4068 in <http://sourceware.org/systemtap/>.
4070 * GDB now supports reversible debugging on ARM, it allows you to
4071 debug basic ARM and THUMB instructions, and provides
4072 record/replay support.
4074 * The option "symbol-reloading" has been deleted as it is no longer used.
4078 ** GDB commands implemented in Python can now be put in command class
4081 ** The "maint set python print-stack on|off" is now deleted.
4083 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4084 apply "flag enum"-style pretty-printing to any enum.
4086 ** gdb.lookup_symbol can now work when there is no current frame.
4088 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4089 the source at which the symbol was defined.
4091 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4092 method 'value'. The former indicates whether the symbol needs a
4093 frame in order to compute its value, and the latter computes the
4096 ** A new method 'referenced_value' on gdb.Value objects which can
4097 dereference pointer as well as C++ reference values.
4099 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4100 which return the global and static blocks (as gdb.Block objects),
4101 of the underlying symbol table, respectively.
4103 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4104 object associated with a PC value.
4106 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4107 of the address range occupied by code for the current source line.
4109 * Go language support.
4110 GDB now supports debugging programs written in the Go programming
4113 * GDBserver now supports stdio connections.
4114 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4116 * The binary "gdbtui" can no longer be built or installed.
4117 Use "gdb -tui" instead.
4119 * GDB will now print "flag" enums specially. A flag enum is one where
4120 all the enumerator values have no bits in common when pairwise
4121 "and"ed. When printing a value whose type is a flag enum, GDB will
4122 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4123 (gdb) print (enum E) 3
4126 * The filename part of a linespec will now match trailing components
4127 of a source file name. For example, "break gcc/expr.c:1000" will
4128 now set a breakpoint in build/gcc/expr.c, but not
4129 build/libcpp/expr.c.
4131 * The "info proc" and "generate-core-file" commands will now also
4132 work on remote targets connected to GDBserver on Linux.
4134 * The command "info catch" has been removed. It has been disabled
4135 since December 2007.
4137 * The "catch exception" and "catch assert" commands now accept
4138 a condition at the end of the command, much like the "break"
4139 command does. For instance:
4141 (gdb) catch exception Constraint_Error if Barrier = True
4143 Previously, it was possible to add a condition to such catchpoints,
4144 but it had to be done as a second step, after the catchpoint had been
4145 created, using the "condition" command.
4147 * The "info static-tracepoint-marker" command will now also work on
4148 native Linux targets with in-process agent.
4150 * GDB can now set breakpoints on inlined functions.
4152 * The .gdb_index section has been updated to include symbols for
4153 inlined functions. GDB will ignore older .gdb_index sections by
4154 default, which could cause symbol files to be loaded more slowly
4155 until their .gdb_index sections can be recreated. The new command
4156 "set use-deprecated-index-sections on" will cause GDB to use any older
4157 .gdb_index sections it finds. This will restore performance, but the
4158 ability to set breakpoints on inlined functions will be lost in symbol
4159 files with older .gdb_index sections.
4161 The .gdb_index section has also been updated to record more information
4162 about each symbol. This speeds up the "info variables", "info functions"
4163 and "info types" commands when used with programs having the .gdb_index
4164 section, as well as speeding up debugging with shared libraries using
4165 the .gdb_index section.
4167 * Ada support for GDB/MI Variable Objects has been added.
4169 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4174 ** New command -info-os is the MI equivalent of "info os".
4176 ** Output logs ("set logging" and related) now include MI output.
4180 ** "set use-deprecated-index-sections on|off"
4181 "show use-deprecated-index-sections on|off"
4182 Controls the use of deprecated .gdb_index sections.
4184 ** "catch load" and "catch unload" can be used to stop when a shared
4185 library is loaded or unloaded, respectively.
4187 ** "enable count" can be used to auto-disable a breakpoint after
4190 ** "info vtbl" can be used to show the virtual method tables for
4191 C++ and Java objects.
4193 ** "explore" and its sub commands "explore value" and "explore type"
4194 can be used to recursively explore values and types of
4195 expressions. These commands are available only if GDB is
4196 configured with '--with-python'.
4198 ** "info auto-load" shows status of all kinds of auto-loaded files,
4199 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4200 sequences of commands files, "info auto-load python-scripts"
4201 shows status of auto-loading Python script files,
4202 "info auto-load local-gdbinit" shows status of loading init file
4203 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4204 status of inferior specific thread debugging shared library loading.
4206 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4207 and "show auto-load-scripts" commands have been deprecated, use their
4208 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4209 and "show auto-load python-scripts" counterparts instead.
4211 ** "dprintf location,format,args..." creates a dynamic printf, which
4212 is basically a breakpoint that does a printf and immediately
4213 resumes your program's execution, so it is like a printf that you
4214 can insert dynamically at runtime instead of at compiletime.
4216 ** "set print symbol"
4218 Controls whether GDB attempts to display the symbol, if any,
4219 corresponding to addresses it prints. This defaults to "on", but
4220 you can set it to "off" to restore GDB's previous behavior.
4222 * Deprecated commands
4224 ** For the Renesas Super-H architecture, the "regs" command has been
4225 deprecated, and "info all-registers" should be used instead.
4229 Renesas RL78 rl78-*-elf
4230 HP OpenVMS ia64 ia64-hp-openvms*
4232 * GDBserver supports evaluation of breakpoint conditions. When
4233 support is advertised by GDBserver, GDB may be told to send the
4234 breakpoint conditions in bytecode form to GDBserver. GDBserver
4235 will only report the breakpoint trigger to GDB when its condition
4240 set mips compression
4241 show mips compression
4242 Select the compressed ISA encoding used in functions that have no symbol
4243 information available. The encoding can be set to either of:
4246 and is updated automatically from ELF file flags if available.
4248 set breakpoint condition-evaluation
4249 show breakpoint condition-evaluation
4250 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4251 GDBserver ("target"). Default option "auto" chooses the most efficient
4253 This option can improve debugger efficiency depending on the speed of the
4257 Disable auto-loading globally.
4260 Show auto-loading setting of all kinds of auto-loaded files.
4262 set auto-load gdb-scripts on|off
4263 show auto-load gdb-scripts
4264 Control auto-loading of GDB canned sequences of commands files.
4266 set auto-load python-scripts on|off
4267 show auto-load python-scripts
4268 Control auto-loading of Python script files.
4270 set auto-load local-gdbinit on|off
4271 show auto-load local-gdbinit
4272 Control loading of init file (.gdbinit) from current directory.
4274 set auto-load libthread-db on|off
4275 show auto-load libthread-db
4276 Control auto-loading of inferior specific thread debugging shared library.
4278 set auto-load scripts-directory <dir1>[:<dir2>...]
4279 show auto-load scripts-directory
4280 Set a list of directories from which to load auto-loaded scripts.
4281 Automatically loaded Python scripts and GDB scripts are located in one
4282 of the directories listed by this option.
4283 The delimiter (':' above) may differ according to the host platform.
4285 set auto-load safe-path <dir1>[:<dir2>...]
4286 show auto-load safe-path
4287 Set a list of directories from which it is safe to auto-load files.
4288 The delimiter (':' above) may differ according to the host platform.
4290 set debug auto-load on|off
4291 show debug auto-load
4292 Control display of debugging info for auto-loading the files above.
4294 set dprintf-style gdb|call|agent
4296 Control the way in which a dynamic printf is performed; "gdb"
4297 requests a GDB printf command, while "call" causes dprintf to call a
4298 function in the inferior. "agent" requests that the target agent
4299 (such as GDBserver) do the printing.
4301 set dprintf-function <expr>
4302 show dprintf-function
4303 set dprintf-channel <expr>
4304 show dprintf-channel
4305 Set the function and optional first argument to the call when using
4306 the "call" style of dynamic printf.
4308 set disconnected-dprintf on|off
4309 show disconnected-dprintf
4310 Control whether agent-style dynamic printfs continue to be in effect
4311 after GDB disconnects.
4313 * New configure options
4315 --with-auto-load-dir
4316 Configure default value for the 'set auto-load scripts-directory'
4317 setting above. It defaults to '$debugdir:$datadir/auto-load',
4318 $debugdir representing global debugging info directories (available
4319 via 'show debug-file-directory') and $datadir representing GDB's data
4320 directory (available via 'show data-directory').
4322 --with-auto-load-safe-path
4323 Configure default value for the 'set auto-load safe-path' setting
4324 above. It defaults to the --with-auto-load-dir setting.
4326 --without-auto-load-safe-path
4327 Set 'set auto-load safe-path' to '/', effectively disabling this
4330 * New remote packets
4332 z0/z1 conditional breakpoints extension
4334 The z0/z1 breakpoint insertion packets have been extended to carry
4335 a list of conditional expressions over to the remote stub depending on the
4336 condition evaluation mode. The use of this extension can be controlled
4337 via the "set remote conditional-breakpoints-packet" command.
4341 Specify the signals which the remote stub may pass to the debugged
4342 program without GDB involvement.
4344 * New command line options
4346 --init-command=FILE, -ix Like --command, -x but execute it
4347 before loading inferior.
4348 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4349 execute it before loading inferior.
4351 *** Changes in GDB 7.4
4353 * GDB now handles ambiguous linespecs more consistently; the existing
4354 FILE:LINE support has been expanded to other types of linespecs. A
4355 breakpoint will now be set on all matching locations in all
4356 inferiors, and locations will be added or removed according to
4359 * GDB now allows you to skip uninteresting functions and files when
4360 stepping with the "skip function" and "skip file" commands.
4362 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4363 and "show remote hardware-watchpoint-length-limit". These allows to
4364 set or show the maximum length limit (in bytes) of a remote
4365 target hardware watchpoint.
4367 This allows e.g. to use "unlimited" hardware watchpoints with the
4368 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4369 watchpoints are slower than real hardware watchpoints but are
4370 significantly faster than gdb software watchpoints.
4374 ** The register_pretty_printer function in module gdb.printing now takes
4375 an optional `replace' argument. If True, the new printer replaces any
4378 ** The "maint set python print-stack on|off" command has been
4379 deprecated and will be deleted in GDB 7.5.
4380 A new command: "set python print-stack none|full|message" has
4381 replaced it. Additionally, the default for "print-stack" is
4382 now "message", which just prints the error message without
4385 ** A prompt substitution hook (prompt_hook) is now available to the
4388 ** A new Python module, gdb.prompt has been added to the GDB Python
4389 modules library. This module provides functionality for
4390 escape sequences in prompts (used by set/show
4391 extended-prompt). These escape sequences are replaced by their
4392 corresponding value.
4394 ** Python commands and convenience-functions located in
4395 'data-directory'/python/gdb/command and
4396 'data-directory'/python/gdb/function are now automatically loaded
4399 ** Blocks now provide four new attributes. global_block and
4400 static_block will return the global and static blocks
4401 respectively. is_static and is_global are boolean attributes
4402 that indicate if the block is one of those two types.
4404 ** Symbols now provide the "type" attribute, the type of the symbol.
4406 ** The "gdb.breakpoint" function has been deprecated in favor of
4409 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4410 of a function. This class is based on the "finish" command
4411 available in the CLI.
4413 ** Type objects for struct and union types now allow access to
4414 the fields using standard Python dictionary (mapping) methods.
4415 For example, "some_type['myfield']" now works, as does
4416 "some_type.items()".
4418 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4421 ** A new function, "deep_items" has been added to the gdb.types
4422 module in the GDB Python modules library. This function returns
4423 an iterator over the fields of a struct or union type. Unlike
4424 the standard Python "iteritems" method, it will recursively traverse
4425 any anonymous fields.
4429 ** "*stopped" events can report several new "reason"s, such as
4432 ** Breakpoint changes are now notified using new async records, like
4433 "=breakpoint-modified".
4435 ** New command -ada-task-info.
4437 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4438 $sdir specifies the default system locations of shared libraries.
4439 $pdir specifies the directory where the libpthread used by the application
4442 GDB no longer looks in $sdir and $pdir after it has searched the directories
4443 mentioned in libthread-db-search-path. If you want to search those
4444 directories, they must be specified in libthread-db-search-path.
4445 The default value of libthread-db-search-path on GNU/Linux and Solaris
4446 systems is now "$sdir:$pdir".
4448 $pdir is not supported by gdbserver, it is currently ignored.
4449 $sdir is supported by gdbserver.
4451 * New configure option --with-iconv-bin.
4452 When using the internationalization support like the one in the GNU C
4453 library, GDB will invoke the "iconv" program to get a list of supported
4454 character sets. If this program lives in a non-standard location, one can
4455 use this option to specify where to find it.
4457 * When natively debugging programs on PowerPC BookE processors running
4458 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4459 watchpoints, which specify a mask in addition to an address to watch.
4460 The mask specifies that some bits of an address (the bits which are
4461 reset in the mask) should be ignored when matching the address accessed
4462 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4463 section in the user manual for more details.
4465 * The new option --once causes GDBserver to stop listening for connections once
4466 the first connection is made. The listening port used by GDBserver will
4467 become available after that.
4469 * New commands "info macros" and "alias" have been added.
4471 * New function parameters suffix @entry specifies value of function parameter
4472 at the time the function got called. Entry values are available only since
4478 "!" is now an alias of the "shell" command.
4479 Note that no space is needed between "!" and SHELL COMMAND.
4483 watch EXPRESSION mask MASK_VALUE
4484 The watch command now supports the mask argument which allows creation
4485 of masked watchpoints, if the current architecture supports this feature.
4487 info auto-load-scripts [REGEXP]
4488 This command was formerly named "maintenance print section-scripts".
4489 It is now generally useful and is no longer a maintenance-only command.
4491 info macro [-all] [--] MACRO
4492 The info macro command has new options `-all' and `--'. The first for
4493 printing all definitions of a macro. The second for explicitly specifying
4494 the end of arguments and the beginning of the macro name in case the macro
4495 name starts with a hyphen.
4497 collect[/s] EXPRESSIONS
4498 The tracepoint collect command now takes an optional modifier "/s"
4499 that directs it to dereference pointer-to-character types and
4500 collect the bytes of memory up to a zero byte. The behavior is
4501 similar to what you see when you use the regular print command on a
4502 string. An optional integer following the "/s" sets a bound on the
4503 number of bytes that will be collected.
4506 The trace start command now interprets any supplied arguments as a
4507 note to be recorded with the trace run, with an effect similar to
4508 setting the variable trace-notes.
4511 The trace stop command now interprets any arguments as a note to be
4512 mentioned along with the tstatus report that the trace was stopped
4513 with a command. The effect is similar to setting the variable
4516 * Tracepoints can now be enabled and disabled at any time after a trace
4517 experiment has been started using the standard "enable" and "disable"
4518 commands. It is now possible to start a trace experiment with no enabled
4519 tracepoints; GDB will display a warning, but will allow the experiment to
4520 begin, assuming that tracepoints will be enabled as needed while the trace
4523 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4524 locations with 4-byte instructions, when they were previously
4525 limited to locations with instructions of 5 bytes or longer.
4529 set debug dwarf2-read
4530 show debug dwarf2-read
4531 Turns on or off display of debugging messages related to reading
4532 DWARF debug info. The default is off.
4534 set debug symtab-create
4535 show debug symtab-create
4536 Turns on or off display of debugging messages related to symbol table
4537 creation. The default is off.
4540 show extended-prompt
4541 Set the GDB prompt, and allow escape sequences to be inserted to
4542 display miscellaneous information (see 'help set extended-prompt'
4543 for the list of sequences). This prompt (and any information
4544 accessed through the escape sequences) is updated every time the
4545 prompt is displayed.
4547 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4548 show print entry-values
4549 Set printing of frame argument values at function entry. In some cases
4550 GDB can determine the value of function argument which was passed by the
4551 function caller, even if the value was modified inside the called function.
4553 set debug entry-values
4554 show debug entry-values
4555 Control display of debugging info for determining frame argument values at
4556 function entry and virtual tail call frames.
4558 set basenames-may-differ
4559 show basenames-may-differ
4560 Set whether a source file may have multiple base names.
4561 (A "base name" is the name of a file with the directory part removed.
4562 Example: The base name of "/home/user/hello.c" is "hello.c".)
4563 If set, GDB will canonicalize file names (e.g., expand symlinks)
4564 before comparing them. Canonicalization is an expensive operation,
4565 but it allows the same file be known by more than one base name.
4566 If not set (the default), all source files are assumed to have just
4567 one base name, and gdb will do file name comparisons more efficiently.
4573 Set a user name and notes for the current and any future trace runs.
4574 This is useful for long-running and/or disconnected traces, to
4575 inform others (or yourself) as to who is running the trace, supply
4576 contact information, or otherwise explain what is going on.
4578 set trace-stop-notes
4579 show trace-stop-notes
4580 Set a note attached to the trace run, that is displayed when the
4581 trace has been stopped by a tstop command. This is useful for
4582 instance as an explanation, if you are stopping a trace run that was
4583 started by someone else.
4585 * New remote packets
4589 Dynamically enable a tracepoint in a started trace experiment.
4593 Dynamically disable a tracepoint in a started trace experiment.
4597 Set the user and notes of the trace run.
4601 Query the current status of a tracepoint.
4605 Query the minimum length of instruction at which a fast tracepoint may
4608 * Dcache size (number of lines) and line-size are now runtime-configurable
4609 via "set dcache line" and "set dcache line-size" commands.
4613 Texas Instruments TMS320C6x tic6x-*-*
4617 Renesas RL78 rl78-*-elf
4619 *** Changes in GDB 7.3.1
4621 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4623 *** Changes in GDB 7.3
4625 * GDB has a new command: "thread find [REGEXP]".
4626 It finds the thread id whose name, target id, or thread extra info
4627 matches the given regular expression.
4629 * The "catch syscall" command now works on mips*-linux* targets.
4631 * The -data-disassemble MI command now supports modes 2 and 3 for
4632 dumping the instruction opcodes.
4634 * New command line options
4636 -data-directory DIR Specify DIR as the "data-directory".
4637 This is mostly for testing purposes.
4639 * The "maint set python auto-load on|off" command has been renamed to
4640 "set auto-load-scripts on|off".
4642 * GDB has a new command: "set directories".
4643 It is like the "dir" command except that it replaces the
4644 source path list instead of augmenting it.
4646 * GDB now understands thread names.
4648 On GNU/Linux, "info threads" will display the thread name as set by
4649 prctl or pthread_setname_np.
4651 There is also a new command, "thread name", which can be used to
4652 assign a name internally for GDB to display.
4655 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4656 has been integrated into GDB.
4660 ** The function gdb.Write now accepts an optional keyword 'stream'.
4661 This keyword, when provided, will direct the output to either
4662 stdout, stderr, or GDB's logging output.
4664 ** Parameters can now be be sub-classed in Python, and in particular
4665 you may implement the get_set_doc and get_show_doc functions.
4666 This improves how Parameter set/show documentation is processed
4667 and allows for more dynamic content.
4669 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4670 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4671 have an is_valid method.
4673 ** Breakpoints can now be sub-classed in Python, and in particular
4674 you may implement a 'stop' function that is executed each time
4675 the inferior reaches that breakpoint.
4677 ** New function gdb.lookup_global_symbol looks up a global symbol.
4679 ** GDB values in Python are now callable if the value represents a
4680 function. For example, if 'some_value' represents a function that
4681 takes two integer parameters and returns a value, you can call
4682 that function like so:
4684 result = some_value (10,20)
4686 ** Module gdb.types has been added.
4687 It contains a collection of utilities for working with gdb.Types objects:
4688 get_basic_type, has_field, make_enum_dict.
4690 ** Module gdb.printing has been added.
4691 It contains utilities for writing and registering pretty-printers.
4692 New classes: PrettyPrinter, SubPrettyPrinter,
4693 RegexpCollectionPrettyPrinter.
4694 New function: register_pretty_printer.
4696 ** New commands "info pretty-printers", "enable pretty-printer" and
4697 "disable pretty-printer" have been added.
4699 ** gdb.parameter("directories") is now available.
4701 ** New function gdb.newest_frame returns the newest frame in the
4704 ** The gdb.InferiorThread class has a new "name" attribute. This
4705 holds the thread's name.
4707 ** Python Support for Inferior events.
4708 Python scripts can add observers to be notified of events
4709 occurring in the process being debugged.
4710 The following events are currently supported:
4711 - gdb.events.cont Continue event.
4712 - gdb.events.exited Inferior exited event.
4713 - gdb.events.stop Signal received, and Breakpoint hit events.
4717 ** GDB now puts template parameters in scope when debugging in an
4718 instantiation. For example, if you have:
4720 template<int X> int func (void) { return X; }
4722 then if you step into func<5>, "print X" will show "5". This
4723 feature requires proper debuginfo support from the compiler; it
4724 was added to GCC 4.5.
4726 ** The motion commands "next", "finish", "until", and "advance" now
4727 work better when exceptions are thrown. In particular, GDB will
4728 no longer lose control of the inferior; instead, the GDB will
4729 stop the inferior at the point at which the exception is caught.
4730 This functionality requires a change in the exception handling
4731 code that was introduced in GCC 4.5.
4733 * GDB now follows GCC's rules on accessing volatile objects when
4734 reading or writing target state during expression evaluation.
4735 One notable difference to prior behavior is that "print x = 0"
4736 no longer generates a read of x; the value of the assignment is
4737 now always taken directly from the value being assigned.
4739 * GDB now has some support for using labels in the program's source in
4740 linespecs. For instance, you can use "advance label" to continue
4741 execution to a label.
4743 * GDB now has support for reading and writing a new .gdb_index
4744 section. This section holds a fast index of DWARF debugging
4745 information and can be used to greatly speed up GDB startup and
4746 operation. See the documentation for `save gdb-index' for details.
4748 * The "watch" command now accepts an optional "-location" argument.
4749 When used, this causes GDB to watch the memory referred to by the
4750 expression. Such a watchpoint is never deleted due to it going out
4753 * GDB now supports thread debugging of core dumps on GNU/Linux.
4755 GDB now activates thread debugging using the libthread_db library
4756 when debugging GNU/Linux core dumps, similarly to when debugging
4757 live processes. As a result, when debugging a core dump file, GDB
4758 is now able to display pthread_t ids of threads. For example, "info
4759 threads" shows the same output as when debugging the process when it
4760 was live. In earlier releases, you'd see something like this:
4763 * 1 LWP 6780 main () at main.c:10
4765 While now you see this:
4768 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4770 It is also now possible to inspect TLS variables when debugging core
4773 When debugging a core dump generated on a machine other than the one
4774 used to run GDB, you may need to point GDB at the correct
4775 libthread_db library with the "set libthread-db-search-path"
4776 command. See the user manual for more details on this command.
4778 * When natively debugging programs on PowerPC BookE processors running
4779 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4780 which stop execution of the inferior whenever it executes an instruction
4781 at any address within the specified range. See the "PowerPC Embedded"
4782 section in the user manual for more details.
4784 * New features in the GDB remote stub, GDBserver
4786 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4787 and i686 LynxOS (version 5.x).
4789 ** GDBserver is now supported on Blackfin Linux.
4791 * New native configurations
4793 ia64 HP-UX ia64-*-hpux*
4797 Analog Devices, Inc. Blackfin Processor bfin-*
4799 * Ada task switching is now supported on sparc-elf targets when
4800 debugging a program using the Ravenscar Profile. For more information,
4801 see the "Tasking Support when using the Ravenscar Profile" section
4802 in the GDB user manual.
4804 * Guile support was removed.
4806 * New features in the GNU simulator
4808 ** The --map-info flag lists all known core mappings.
4810 ** CFI flashes may be simulated via the "cfi" device.
4812 *** Changes in GDB 7.2
4814 * Shared library support for remote targets by default
4816 When GDB is configured for a generic, non-OS specific target, like
4817 for example, --target=arm-eabi or one of the many *-*-elf targets,
4818 GDB now queries remote stubs for loaded shared libraries using the
4819 `qXfer:libraries:read' packet. Previously, shared library support
4820 was always disabled for such configurations.
4824 ** Argument Dependent Lookup (ADL)
4826 In C++ ADL lookup directs function search to the namespaces of its
4827 arguments even if the namespace has not been imported.
4837 Here the compiler will search for `foo' in the namespace of 'b'
4838 and find A::foo. GDB now supports this. This construct is commonly
4839 used in the Standard Template Library for operators.
4841 ** Improved User Defined Operator Support
4843 In addition to member operators, GDB now supports lookup of operators
4844 defined in a namespace and imported with a `using' directive, operators
4845 defined in the global scope, operators imported implicitly from an
4846 anonymous namespace, and the ADL operators mentioned in the previous
4848 GDB now also supports proper overload resolution for all the previously
4849 mentioned flavors of operators.
4851 ** static const class members
4853 Printing of static const class members that are initialized in the
4854 class definition has been fixed.
4856 * Windows Thread Information Block access.
4858 On Windows targets, GDB now supports displaying the Windows Thread
4859 Information Block (TIB) structure. This structure is visible either
4860 by using the new command `info w32 thread-information-block' or, by
4861 dereferencing the new convenience variable named `$_tlb', a
4862 thread-specific pointer to the TIB. This feature is also supported
4863 when remote debugging using GDBserver.
4865 * Static tracepoints
4867 Static tracepoints are calls in the user program into a tracing
4868 library. One such library is a port of the LTTng kernel tracer to
4869 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4870 When debugging with GDBserver, GDB now supports combining the GDB
4871 tracepoint machinery with such libraries. For example: the user can
4872 use GDB to probe a static tracepoint marker (a call from the user
4873 program into the tracing library) with the new "strace" command (see
4874 "New commands" below). This creates a "static tracepoint" in the
4875 breakpoint list, that can be manipulated with the same feature set
4876 as fast and regular tracepoints. E.g., collect registers, local and
4877 global variables, collect trace state variables, and define
4878 tracepoint conditions. In addition, the user can collect extra
4879 static tracepoint marker specific data, by collecting the new
4880 $_sdata internal variable. When analyzing the trace buffer, you can
4881 inspect $_sdata like any other variable available to GDB. For more
4882 information, see the "Tracepoints" chapter in GDB user manual. New
4883 remote packets have been defined to support static tracepoints, see
4884 the "New remote packets" section below.
4886 * Better reconstruction of tracepoints after disconnected tracing
4888 GDB will attempt to download the original source form of tracepoint
4889 definitions when starting a trace run, and then will upload these
4890 upon reconnection to the target, resulting in a more accurate
4891 reconstruction of the tracepoints that are in use on the target.
4895 You can now exercise direct control over the ways that GDB can
4896 affect your program. For instance, you can disallow the setting of
4897 breakpoints, so that the program can run continuously (assuming
4898 non-stop mode). In addition, the "observer" variable is available
4899 to switch all of the different controls; in observer mode, GDB
4900 cannot affect the target's behavior at all, which is useful for
4901 tasks like diagnosing live systems in the field.
4903 * The new convenience variable $_thread holds the number of the
4906 * New remote packets
4910 Return the address of the Windows Thread Information Block of a given thread.
4914 In response to several of the tracepoint packets, the target may now
4915 also respond with a number of intermediate `qRelocInsn' request
4916 packets before the final result packet, to have GDB handle
4917 relocating an instruction to execute at a different address. This
4918 is particularly useful for stubs that support fast tracepoints. GDB
4919 reports support for this feature in the qSupported packet.
4923 List static tracepoint markers in the target program.
4927 List static tracepoint markers at a given address in the target
4930 qXfer:statictrace:read
4932 Read the static trace data collected (by a `collect $_sdata'
4933 tracepoint action). The remote stub reports support for this packet
4934 to gdb's qSupported query.
4938 Send the current settings of GDB's permission flags.
4942 Send part of the source (textual) form of a tracepoint definition,
4943 which includes location, conditional, and action list.
4945 * The source command now accepts a -s option to force searching for the
4946 script in the source search path even if the script name specifies
4949 * New features in the GDB remote stub, GDBserver
4951 - GDBserver now support tracepoints (including fast tracepoints, and
4952 static tracepoints). The feature is currently supported by the
4953 i386-linux and amd64-linux builds. See the "Tracepoints support
4954 in gdbserver" section in the manual for more information.
4956 GDBserver JIT compiles the tracepoint's conditional agent
4957 expression bytecode into native code whenever possible for low
4958 overhead dynamic tracepoints conditionals. For such tracepoints,
4959 an expression that examines program state is evaluated when the
4960 tracepoint is reached, in order to determine whether to capture
4961 trace data. If the condition is simple and false, processing the
4962 tracepoint finishes very quickly and no data is gathered.
4964 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4965 for static tracepoints support.
4967 - GDBserver now supports x86_64 Windows 64-bit debugging.
4969 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4970 it understands register description.
4972 * The --batch flag now disables pagination and queries.
4974 * X86 general purpose registers
4976 GDB now supports reading/writing byte, word and double-word x86
4977 general purpose registers directly. This means you can use, say,
4978 $ah or $ax to refer, respectively, to the byte register AH and
4979 16-bit word register AX that are actually portions of the 32-bit
4980 register EAX or 64-bit register RAX.
4982 * The `commands' command now accepts a range of breakpoints to modify.
4983 A plain `commands' following a command that creates multiple
4984 breakpoints affects all the breakpoints set by that command. This
4985 applies to breakpoints set by `rbreak', and also applies when a
4986 single `break' command creates multiple breakpoints (e.g.,
4987 breakpoints on overloaded c++ functions).
4989 * The `rbreak' command now accepts a filename specification as part of
4990 its argument, limiting the functions selected by the regex to those
4991 in the specified file.
4993 * Support for remote debugging Windows and SymbianOS shared libraries
4994 from Unix hosts has been improved. Non Windows GDB builds now can
4995 understand target reported file names that follow MS-DOS based file
4996 system semantics, such as file names that include drive letters and
4997 use the backslash character as directory separator. This makes it
4998 possible to transparently use the "set sysroot" and "set
4999 solib-search-path" on Unix hosts to point as host copies of the
5000 target's shared libraries. See the new command "set
5001 target-file-system-kind" described below, and the "Commands to
5002 specify files" section in the user manual for more information.
5006 eval template, expressions...
5007 Convert the values of one or more expressions under the control
5008 of the string template to a command line, and call it.
5010 set target-file-system-kind unix|dos-based|auto
5011 show target-file-system-kind
5012 Set or show the assumed file system kind for target reported file
5015 save breakpoints <filename>
5016 Save all current breakpoint definitions to a file suitable for use
5017 in a later debugging session. To read the saved breakpoint
5018 definitions, use the `source' command.
5020 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5023 info static-tracepoint-markers
5024 Display information about static tracepoint markers in the target.
5026 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5027 Define a static tracepoint by probing a marker at the given
5028 function, line, address, or marker ID.
5032 Enable and disable observer mode.
5034 set may-write-registers on|off
5035 set may-write-memory on|off
5036 set may-insert-breakpoints on|off
5037 set may-insert-tracepoints on|off
5038 set may-insert-fast-tracepoints on|off
5039 set may-interrupt on|off
5040 Set individual permissions for GDB effects on the target. Note that
5041 some of these settings can have undesirable or surprising
5042 consequences, particularly when changed in the middle of a session.
5043 For instance, disabling the writing of memory can prevent
5044 breakpoints from being inserted, cause single-stepping to fail, or
5045 even crash your program, if you disable after breakpoints have been
5046 inserted. However, GDB should not crash.
5048 set record memory-query on|off
5049 show record memory-query
5050 Control whether to stop the inferior if memory changes caused
5051 by an instruction cannot be recorded.
5056 The disassemble command now supports "start,+length" form of two arguments.
5060 ** GDB now provides a new directory location, called the python directory,
5061 where Python scripts written for GDB can be installed. The location
5062 of that directory is <data-directory>/python, where <data-directory>
5063 is the GDB data directory. For more details, see section `Scripting
5064 GDB using Python' in the manual.
5066 ** The GDB Python API now has access to breakpoints, symbols, symbol
5067 tables, program spaces, inferiors, threads and frame's code blocks.
5068 Additionally, GDB Parameters can now be created from the API, and
5069 manipulated via set/show in the CLI.
5071 ** New functions gdb.target_charset, gdb.target_wide_charset,
5072 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5074 ** New exception gdb.GdbError.
5076 ** Pretty-printers are now also looked up in the current program space.
5078 ** Pretty-printers can now be individually enabled and disabled.
5080 ** GDB now looks for names of Python scripts to auto-load in a
5081 special section named `.debug_gdb_scripts', in addition to looking
5082 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5084 * Tracepoint actions were unified with breakpoint commands. In particular,
5085 there are no longer differences in "info break" output for breakpoints and
5086 tracepoints and the "commands" command can be used for both tracepoints and
5087 regular breakpoints.
5091 ARM Symbian arm*-*-symbianelf*
5093 * D language support.
5094 GDB now supports debugging programs written in the D programming
5097 * GDB now supports the extended ptrace interface for PowerPC which is
5098 available since Linux kernel version 2.6.34. This automatically enables
5099 any hardware breakpoints and additional hardware watchpoints available in
5100 the processor. The old ptrace interface exposes just one hardware
5101 watchpoint and no hardware breakpoints.
5103 * GDB is now able to use the Data Value Compare (DVC) register available on
5104 embedded PowerPC processors to implement in hardware simple watchpoint
5105 conditions of the form:
5107 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5109 This works in native GDB running on Linux kernels with the extended ptrace
5110 interface mentioned above.
5112 *** Changes in GDB 7.1
5116 ** Namespace Support
5118 GDB now supports importing of namespaces in C++. This enables the
5119 user to inspect variables from imported namespaces. Support for
5120 namepace aliasing has also been added. So, if a namespace is
5121 aliased in the current scope (e.g. namepace C=A; ) the user can
5122 print variables using the alias (e.g. (gdb) print C::x).
5126 All known bugs relating to the printing of virtual base class were
5127 fixed. It is now possible to call overloaded static methods using a
5132 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5133 and reinterpret_cast<> are now handled by the C++ expression parser.
5137 Xilinx MicroBlaze microblaze-*-*
5142 Xilinx MicroBlaze microblaze
5145 * Multi-program debugging.
5147 GDB now has support for multi-program (a.k.a. multi-executable or
5148 multi-exec) debugging. This allows for debugging multiple inferiors
5149 simultaneously each running a different program under the same GDB
5150 session. See "Debugging Multiple Inferiors and Programs" in the
5151 manual for more information. This implied some user visible changes
5152 in the multi-inferior support. For example, "info inferiors" now
5153 lists inferiors that are not running yet or that have exited
5154 already. See also "New commands" and "New options" below.
5156 * New tracing features
5158 GDB's tracepoint facility now includes several new features:
5160 ** Trace state variables
5162 GDB tracepoints now include support for trace state variables, which
5163 are variables managed by the target agent during a tracing
5164 experiment. They are useful for tracepoints that trigger each
5165 other, so for instance one tracepoint can count hits in a variable,
5166 and then a second tracepoint has a condition that is true when the
5167 count reaches a particular value. Trace state variables share the
5168 $-syntax of GDB convenience variables, and can appear in both
5169 tracepoint actions and condition expressions. Use the "tvariable"
5170 command to create, and "info tvariables" to view; see "Trace State
5171 Variables" in the manual for more detail.
5175 GDB now includes an option for defining fast tracepoints, which
5176 targets may implement more efficiently, such as by installing a jump
5177 into the target agent rather than a trap instruction. The resulting
5178 speedup can be by two orders of magnitude or more, although the
5179 tradeoff is that some program locations on some target architectures
5180 might not allow fast tracepoint installation, for instance if the
5181 instruction to be replaced is shorter than the jump. To request a
5182 fast tracepoint, use the "ftrace" command, with syntax identical to
5183 the regular trace command.
5185 ** Disconnected tracing
5187 It is now possible to detach GDB from the target while it is running
5188 a trace experiment, then reconnect later to see how the experiment
5189 is going. In addition, a new variable disconnected-tracing lets you
5190 tell the target agent whether to continue running a trace if the
5191 connection is lost unexpectedly.
5195 GDB now has the ability to save the trace buffer into a file, and
5196 then use that file as a target, similarly to you can do with
5197 corefiles. You can select trace frames, print data that was
5198 collected in them, and use tstatus to display the state of the
5199 tracing run at the moment that it was saved. To create a trace
5200 file, use "tsave <filename>", and to use it, do "target tfile
5203 ** Circular trace buffer
5205 You can ask the target agent to handle the trace buffer as a
5206 circular buffer, discarding the oldest trace frames to make room for
5207 newer ones, by setting circular-trace-buffer to on. This feature may
5208 not be available for all target agents.
5213 The disassemble command, when invoked with two arguments, now requires
5214 the arguments to be comma-separated.
5217 The info variables command now displays variable definitions. Files
5218 which only declare a variable are not shown.
5221 The source command is now capable of sourcing Python scripts.
5222 This feature is dependent on the debugger being build with Python
5225 Related to this enhancement is also the introduction of a new command
5226 "set script-extension" (see below).
5228 * New commands (for set/show, see "New options" below)
5230 record save [<FILENAME>]
5231 Save a file (in core file format) containing the process record
5232 execution log for replay debugging at a later time.
5234 record restore <FILENAME>
5235 Restore the process record execution log that was saved at an
5236 earlier time, for replay debugging.
5238 add-inferior [-copies <N>] [-exec <FILENAME>]
5241 clone-inferior [-copies <N>] [ID]
5242 Make a new inferior ready to execute the same program another
5243 inferior has loaded.
5248 maint info program-spaces
5249 List the program spaces loaded into GDB.
5251 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5252 show remote interrupt-sequence
5253 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5254 as the sequence to the remote target in order to interrupt the execution.
5255 Ctrl-C is a default. Some system prefers BREAK which is high level of
5256 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5257 Magic SysRq g. It is BREAK signal and character 'g'.
5259 set remote interrupt-on-connect [on | off]
5260 show remote interrupt-on-connect
5261 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5262 remote target when gdb connects to it. This is needed when you debug
5265 set remotebreak [on | off]
5267 Deprecated. Use "set/show remote interrupt-sequence" instead.
5269 tvariable $NAME [ = EXP ]
5270 Create or modify a trace state variable.
5273 List trace state variables and their values.
5275 delete tvariable $NAME ...
5276 Delete one or more trace state variables.
5279 Evaluate the given expressions without collecting anything into the
5280 trace buffer. (Valid in tracepoint actions only.)
5282 ftrace FN / FILE:LINE / *ADDR
5283 Define a fast tracepoint at the given function, line, or address.
5285 * New expression syntax
5287 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5288 GDB now parses 0b101010 identically with 42.
5292 set follow-exec-mode new|same
5293 show follow-exec-mode
5294 Control whether GDB reuses the same inferior across an exec call or
5295 creates a new one. This is useful to be able to restart the old
5296 executable after the inferior having done an exec call.
5298 set default-collect EXPR, ...
5299 show default-collect
5300 Define a list of expressions to be collected at each tracepoint.
5301 This is a useful way to ensure essential items are not overlooked,
5302 such as registers or a critical global variable.
5304 set disconnected-tracing
5305 show disconnected-tracing
5306 If set to 1, the target is instructed to continue tracing if it
5307 loses its connection to GDB. If 0, the target is to stop tracing
5310 set circular-trace-buffer
5311 show circular-trace-buffer
5312 If set to on, the target is instructed to use a circular trace buffer
5313 and discard the oldest trace frames instead of stopping the trace due
5314 to a full trace buffer. If set to off, the trace stops when the buffer
5315 fills up. Some targets may not support this.
5317 set script-extension off|soft|strict
5318 show script-extension
5319 If set to "off", the debugger does not perform any script language
5320 recognition, and all sourced files are assumed to be GDB scripts.
5321 If set to "soft" (the default), files are sourced according to
5322 filename extension, falling back to GDB scripts if the first
5324 If set to "strict", files are sourced according to filename extension.
5326 set ada trust-PAD-over-XVS on|off
5327 show ada trust-PAD-over-XVS
5328 If off, activate a workaround against a bug in the debugging information
5329 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5330 the GCC sources for more information about the GNAT encoding and
5331 PAD types in particular). It is always safe to set this option to
5332 off, but this introduces a slight performance penalty. The default
5335 * Python API Improvements
5337 ** GDB provides the new class gdb.LazyString. This is useful in
5338 some pretty-printing cases. The new method gdb.Value.lazy_string
5339 provides a simple way to create objects of this type.
5341 ** The fields returned by gdb.Type.fields now have an
5342 `is_base_class' attribute.
5344 ** The new method gdb.Type.range returns the range of an array type.
5346 ** The new method gdb.parse_and_eval can be used to parse and
5347 evaluate an expression.
5349 * New remote packets
5352 Define a trace state variable.
5355 Get the current value of a trace state variable.
5358 Set desired tracing behavior upon disconnection.
5361 Set the trace buffer to be linear or circular.
5364 Get data about the tracepoints currently in use.
5368 Process record now works correctly with hardware watchpoints.
5370 Multiple bug fixes have been made to the mips-irix port, making it
5371 much more reliable. In particular:
5372 - Debugging threaded applications is now possible again. Previously,
5373 GDB would hang while starting the program, or while waiting for
5374 the program to stop at a breakpoint.
5375 - Attaching to a running process no longer hangs.
5376 - An error occurring while loading a core file has been fixed.
5377 - Changing the value of the PC register now works again. This fixes
5378 problems observed when using the "jump" command, or when calling
5379 a function from GDB, or even when assigning a new value to $pc.
5380 - With the "finish" and "return" commands, the return value for functions
5381 returning a small array is now correctly printed.
5382 - It is now possible to break on shared library code which gets executed
5383 during a shared library init phase (code executed while executing
5384 their .init section). Previously, the breakpoint would have no effect.
5385 - GDB is now able to backtrace through the signal handler for
5386 non-threaded programs.
5388 PIE (Position Independent Executable) programs debugging is now supported.
5389 This includes debugging execution of PIC (Position Independent Code) shared
5390 libraries although for that, it should be possible to run such libraries as an
5393 *** Changes in GDB 7.0
5395 * GDB now has an interface for JIT compilation. Applications that
5396 dynamically generate code can create symbol files in memory and register
5397 them with GDB. For users, the feature should work transparently, and
5398 for JIT developers, the interface is documented in the GDB manual in the
5399 "JIT Compilation Interface" chapter.
5401 * Tracepoints may now be conditional. The syntax is as for
5402 breakpoints; either an "if" clause appended to the "trace" command,
5403 or the "condition" command is available. GDB sends the condition to
5404 the target for evaluation using the same bytecode format as is used
5405 for tracepoint actions.
5407 * The disassemble command now supports: an optional /r modifier, print the
5408 raw instructions in hex as well as in symbolic form, and an optional /m
5409 modifier to print mixed source+assembly.
5411 * Process record and replay
5413 In a architecture environment that supports ``process record and
5414 replay'', ``process record and replay'' target can record a log of
5415 the process execution, and replay it with both forward and reverse
5418 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5419 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5420 set execution-direction {forward|reverse}, for targets that support
5423 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5424 feature is available with a native GDB running on kernel version
5427 * GDB now has support for multi-byte and wide character sets on the
5428 target. Strings whose character type is wchar_t, char16_t, or
5429 char32_t are now correctly printed. GDB supports wide- and unicode-
5430 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5431 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5432 `printf'. This feature requires iconv to work properly; if your
5433 system does not have a working iconv, GDB can use GNU libiconv. See
5434 the installation instructions for more information.
5436 * GDB now supports automatic retrieval of shared library files from
5437 remote targets. To use this feature, specify a system root that begins
5438 with the `remote:' prefix, either via the `set sysroot' command or via
5439 the `--with-sysroot' configure-time option.
5441 * "info sharedlibrary" now takes an optional regex of libraries to show,
5442 and it now reports if a shared library has no debugging information.
5444 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5445 now complete on file names.
5447 * When completing in expressions, gdb will attempt to limit
5448 completions to allowable structure or union fields, where appropriate.
5449 For instance, consider:
5451 # struct example { int f1; double f2; };
5452 # struct example variable;
5455 If the user types TAB at the end of this command line, the available
5456 completions will be "f1" and "f2".
5458 * Inlined functions are now supported. They show up in backtraces, and
5459 the "step", "next", and "finish" commands handle them automatically.
5461 * GDB now supports the token-splicing (##) and stringification (#)
5462 operators when expanding macros. It also supports variable-arity
5465 * GDB now supports inspecting extra signal information, exported by
5466 the new $_siginfo convenience variable. The feature is currently
5467 implemented on linux ARM, i386 and amd64.
5469 * GDB can now display the VFP floating point registers and NEON vector
5470 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5471 can provide these registers (requires Linux 2.6.30 or later). Remote
5472 and simulator targets may also provide them.
5474 * New remote packets
5477 Search memory for a sequence of bytes.
5480 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5481 operation over reliable transport links. Use of this packet is
5482 controlled by the `set remote noack-packet' command.
5485 Kill the process with the specified process ID. Use this in preference
5486 to `k' when multiprocess protocol extensions are supported.
5489 Obtains additional operating system information
5493 Read or write additional signal information.
5495 * Removed remote protocol undocumented extension
5497 An undocumented extension to the remote protocol's `S' stop reply
5498 packet that permitted the stub to pass a process id was removed.
5499 Remote servers should use the `T' stop reply packet instead.
5501 * GDB now supports multiple function calling conventions according to the
5502 DWARF-2 DW_AT_calling_convention function attribute.
5504 * The SH target utilizes the aforementioned change to distinguish between gcc
5505 and Renesas calling convention. It also adds the new CLI commands
5506 `set/show sh calling-convention'.
5508 * GDB can now read compressed debug sections, as produced by GNU gold
5509 with the --compress-debug-sections=zlib flag.
5511 * 64-bit core files are now supported on AIX.
5513 * Thread switching is now supported on Tru64.
5515 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5516 which will be allocated using malloc later in program execution.
5518 * The qXfer:libraries:read remote protocol packet now allows passing a
5519 list of section offsets.
5521 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5522 conditions handling signals delivered during attach or thread creation
5523 have also been fixed.
5525 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5526 From the user's standpoint, all unqualified instances of True and False
5527 are treated as the standard definitions, regardless of context.
5529 * GDB now parses C++ symbol and type names more flexibly. For
5532 template<typename T> class C { };
5535 GDB will now correctly handle all of:
5537 ptype C<char const *>
5538 ptype C<char const*>
5539 ptype C<const char *>
5540 ptype C<const char*>
5542 * New features in the GDB remote stub, gdbserver
5544 - The "--wrapper" command-line argument tells gdbserver to use a
5545 wrapper program to launch programs for debugging.
5547 - On PowerPC and S/390 targets, it is now possible to use a single
5548 gdbserver executable to debug both 32-bit and 64-bit programs.
5549 (This requires gdbserver itself to be built as a 64-bit executable.)
5551 - gdbserver uses the new noack protocol mode for TCP connections to
5552 reduce communications latency, if also supported and enabled in GDB.
5554 - Support for the sparc64-linux-gnu target is now included in
5557 - The amd64-linux build of gdbserver now supports debugging both
5558 32-bit and 64-bit programs.
5560 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5561 now support hardware watchpoints, and will use them automatically
5566 GDB now has support for scripting using Python. Whether this is
5567 available is determined at configure time.
5569 New GDB commands can now be written in Python.
5571 * Ada tasking support
5573 Ada tasks can now be inspected in GDB. The following commands have
5577 Print the list of Ada tasks.
5579 Print detailed information about task number N.
5581 Print the task number of the current task.
5583 Switch the context of debugging to task number N.
5585 * Support for user-defined prefixed commands. The "define" command can
5586 add new commands to existing prefixes, e.g. "target".
5588 * Multi-inferior, multi-process debugging.
5590 GDB now has generalized support for multi-inferior debugging. See
5591 "Debugging Multiple Inferiors" in the manual for more information.
5592 Although availability still depends on target support, the command
5593 set is more uniform now. The GNU/Linux specific multi-forks support
5594 has been migrated to this new framework. This implied some user
5595 visible changes; see "New commands" and also "Removed commands"
5598 * Target descriptions can now describe the target OS ABI. See the
5599 "Target Description Format" section in the user manual for more
5602 * Target descriptions can now describe "compatible" architectures
5603 to indicate that the target can execute applications for a different
5604 architecture in addition to those for the main target architecture.
5605 See the "Target Description Format" section in the user manual for
5608 * Multi-architecture debugging.
5610 GDB now includes general supports for debugging applications on
5611 hybrid systems that use more than one single processor architecture
5612 at the same time. Each such hybrid architecture still requires
5613 specific support to be added. The only hybrid architecture supported
5614 in this version of GDB is the Cell Broadband Engine.
5616 * GDB now supports integrated debugging of Cell/B.E. applications that
5617 use both the PPU and SPU architectures. To enable support for hybrid
5618 Cell/B.E. debugging, you need to configure GDB to support both the
5619 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5620 --enable-targets configure option.
5622 * Non-stop mode debugging.
5624 For some targets, GDB now supports an optional mode of operation in
5625 which you can examine stopped threads while other threads continue
5626 to execute freely. This is referred to as non-stop mode, with the
5627 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5628 section in the user manual for more information.
5630 To be able to support remote non-stop debugging, a remote stub needs
5631 to implement the non-stop mode remote protocol extensions, as
5632 described in the "Remote Non-Stop" section of the user manual. The
5633 GDB remote stub, gdbserver, has been adjusted to support these
5634 extensions on linux targets.
5636 * New commands (for set/show, see "New options" below)
5638 catch syscall [NAME(S) | NUMBER(S)]
5639 Catch system calls. Arguments, which should be names of system
5640 calls or their numbers, mean catch only those syscalls. Without
5641 arguments, every syscall will be caught. When the inferior issues
5642 any of the specified syscalls, GDB will stop and announce the system
5643 call, both when it is called and when its call returns. This
5644 feature is currently available with a native GDB running on the
5645 Linux Kernel, under the following architectures: x86, x86_64,
5646 PowerPC and PowerPC64.
5648 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5650 Search memory for a sequence of bytes.
5652 maint set python print-stack
5653 maint show python print-stack
5654 Show a stack trace when an error is encountered in a Python script.
5657 Invoke CODE by passing it to the Python interpreter.
5662 These allow macros to be defined, undefined, and listed
5666 Show operating system information about processes.
5669 List the inferiors currently under GDB's control.
5672 Switch focus to inferior number NUM.
5675 Detach from inferior number NUM.
5678 Kill inferior number NUM.
5682 set spu stop-on-load
5683 show spu stop-on-load
5684 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5686 set spu auto-flush-cache
5687 show spu auto-flush-cache
5688 Control whether to automatically flush the software-managed cache
5689 during Cell/B.E. debugging.
5691 set sh calling-convention
5692 show sh calling-convention
5693 Control the calling convention used when calling SH target functions.
5696 show debug timestamp
5697 Control display of timestamps with GDB debugging output.
5699 set disassemble-next-line
5700 show disassemble-next-line
5701 Control display of disassembled source lines or instructions when
5704 set remote noack-packet
5705 show remote noack-packet
5706 Set/show the use of remote protocol QStartNoAckMode packet. See above
5707 under "New remote packets."
5709 set remote query-attached-packet
5710 show remote query-attached-packet
5711 Control use of remote protocol `qAttached' (query-attached) packet.
5713 set remote read-siginfo-object
5714 show remote read-siginfo-object
5715 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5718 set remote write-siginfo-object
5719 show remote write-siginfo-object
5720 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5723 set remote reverse-continue
5724 show remote reverse-continue
5725 Control use of remote protocol 'bc' (reverse-continue) packet.
5727 set remote reverse-step
5728 show remote reverse-step
5729 Control use of remote protocol 'bs' (reverse-step) packet.
5731 set displaced-stepping
5732 show displaced-stepping
5733 Control displaced stepping mode. Displaced stepping is a way to
5734 single-step over breakpoints without removing them from the debuggee.
5735 Also known as "out-of-line single-stepping".
5738 show debug displaced
5739 Control display of debugging info for displaced stepping.
5741 maint set internal-error
5742 maint show internal-error
5743 Control what GDB does when an internal error is detected.
5745 maint set internal-warning
5746 maint show internal-warning
5747 Control what GDB does when an internal warning is detected.
5752 Use a wrapper program to launch programs for debugging.
5754 set multiple-symbols (all|ask|cancel)
5755 show multiple-symbols
5756 The value of this variable can be changed to adjust the debugger behavior
5757 when an expression or a breakpoint location contains an ambiguous symbol
5758 name (an overloaded function name, for instance).
5760 set breakpoint always-inserted
5761 show breakpoint always-inserted
5762 Keep breakpoints always inserted in the target, as opposed to inserting
5763 them when resuming the target, and removing them when the target stops.
5764 This option can improve debugger performance on slow remote targets.
5766 set arm fallback-mode (arm|thumb|auto)
5767 show arm fallback-mode
5768 set arm force-mode (arm|thumb|auto)
5770 These commands control how ARM GDB determines whether instructions
5771 are ARM or Thumb. The default for both settings is auto, which uses
5772 the current CPSR value for instructions without symbols; previous
5773 versions of GDB behaved as if "set arm fallback-mode arm".
5775 set arm unwind-secure-frames
5776 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5778 This can trigger security exceptions when unwinding exception stacks.
5780 set disable-randomization
5781 show disable-randomization
5782 Standalone programs run with the virtual address space randomization enabled
5783 by default on some platforms. This option keeps the addresses stable across
5784 multiple debugging sessions.
5788 Control whether other threads are stopped or not when some thread hits
5793 Requests that asynchronous execution is enabled in the target, if available.
5794 In this case, it's possible to resume target in the background, and interact
5795 with GDB while the target is running. "show target-async" displays the
5796 current state of asynchronous execution of the target.
5798 set target-wide-charset
5799 show target-wide-charset
5800 The target-wide-charset is the name of the character set that GDB
5801 uses when printing characters whose type is wchar_t.
5803 set tcp auto-retry (on|off)
5805 set tcp connect-timeout
5806 show tcp connect-timeout
5807 These commands allow GDB to retry failed TCP connections to a remote stub
5808 with a specified timeout period; this is useful if the stub is launched
5809 in parallel with GDB but may not be ready to accept connections immediately.
5811 set libthread-db-search-path
5812 show libthread-db-search-path
5813 Control list of directories which GDB will search for appropriate
5816 set schedule-multiple (on|off)
5817 show schedule-multiple
5818 Allow GDB to resume all threads of all processes or only threads of
5819 the current process.
5823 Use more aggressive caching for accesses to the stack. This improves
5824 performance of remote debugging (particularly backtraces) without
5825 affecting correctness.
5827 set interactive-mode (on|off|auto)
5828 show interactive-mode
5829 Control whether GDB runs in interactive mode (on) or not (off).
5830 When in interactive mode, GDB waits for the user to answer all
5831 queries. Otherwise, GDB does not wait and assumes the default
5832 answer. When set to auto (the default), GDB determines which
5833 mode to use based on the stdin settings.
5838 For program forks, this is replaced by the new more generic `info
5839 inferiors' command. To list checkpoints, you can still use the
5840 `info checkpoints' command, which was an alias for the `info forks'
5844 Replaced by the new `inferior' command. To switch between
5845 checkpoints, you can still use the `restart' command, which was an
5846 alias for the `fork' command.
5849 This is removed, since some targets don't have a notion of
5850 processes. To switch between processes, you can still use the
5851 `inferior' command using GDB's own inferior number.
5854 For program forks, this is replaced by the new more generic `kill
5855 inferior' command. To delete a checkpoint, you can still use the
5856 `delete checkpoint' command, which was an alias for the `delete
5860 For program forks, this is replaced by the new more generic `detach
5861 inferior' command. To detach a checkpoint, you can still use the
5862 `detach checkpoint' command, which was an alias for the `detach
5865 * New native configurations
5867 x86/x86_64 Darwin i[34567]86-*-darwin*
5869 x86_64 MinGW x86_64-*-mingw*
5873 Lattice Mico32 lm32-*
5874 x86 DICOS i[34567]86-*-dicos*
5875 x86_64 DICOS x86_64-*-dicos*
5878 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5879 (mingw32ce) debugging.
5885 These commands were actually not implemented on any target.
5887 *** Changes in GDB 6.8
5889 * New native configurations
5891 NetBSD/hppa hppa*-*netbsd*
5892 Xtensa GNU/Linux xtensa*-*-linux*
5896 NetBSD/hppa hppa*-*-netbsd*
5897 Xtensa GNU/Linux xtensa*-*-linux*
5899 * Change in command line behavior -- corefiles vs. process ids.
5901 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5902 attaching to process NUMBER fails, GDB no longer attempts to open a
5903 core file named NUMBER. Attaching to a program using the -c option
5904 is no longer supported. Instead, use the '-p' or '--pid' options.
5906 * GDB can now be built as a native debugger for debugging Windows x86
5907 (mingw32) Portable Executable (PE) programs.
5909 * Pending breakpoints no longer change their number when their address
5912 * GDB now supports breakpoints with multiple locations,
5913 including breakpoints on C++ constructors, inside C++ templates,
5914 and in inlined functions.
5916 * GDB's ability to debug optimized code has been improved. GDB more
5917 accurately identifies function bodies and lexical blocks that occupy
5918 more than one contiguous range of addresses.
5920 * Target descriptions can now describe registers for PowerPC.
5922 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5923 registers on PowerPC targets.
5925 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5926 targets even when the libthread_db library is not available.
5928 * The GDB remote stub, gdbserver, now supports the new file transfer
5929 commands (remote put, remote get, and remote delete).
5931 * The GDB remote stub, gdbserver, now supports run and attach in
5932 extended-remote mode.
5934 * hppa*64*-*-hpux11* target broken
5935 The debugger is unable to start a program and fails with the following
5936 error: "Error trying to get information about dynamic linker".
5937 The gdb-6.7 release is also affected.
5939 * GDB now supports the --enable-targets= configure option to allow
5940 building a single GDB executable that supports multiple remote
5941 target architectures.
5943 * GDB now supports debugging C and C++ programs which use the
5944 Decimal Floating Point extension. In addition, the PowerPC target
5945 now has a set of pseudo-registers to inspect decimal float values
5946 stored in two consecutive float registers.
5948 * The -break-insert MI command can optionally create pending
5951 * Improved support for debugging Ada
5952 Many improvements to the Ada language support have been made. These
5954 - Better support for Ada2005 interface types
5955 - Improved handling of arrays and slices in general
5956 - Better support for Taft-amendment types
5957 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5959 - Improved command completion in Ada
5962 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5967 set print frame-arguments (all|scalars|none)
5968 show print frame-arguments
5969 The value of this variable can be changed to control which argument
5970 values should be printed by the debugger when displaying a frame.
5975 Transfer files to and from a remote target, and delete remote files.
5982 Transfer files to and from a remote target, and delete remote files.
5984 * New remote packets
5991 Open, close, read, write, and delete files on the remote system.
5994 Attach to an existing process on the remote system, in extended-remote
5998 Run a new process on the remote system, in extended-remote mode.
6000 *** Changes in GDB 6.7
6002 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6003 bfd, libiberty and opcodes, as revealed by static analysis donated by
6004 Coverity, Inc. (http://scan.coverity.com).
6006 * When looking up multiply-defined global symbols, GDB will now prefer the
6007 symbol definition in the current shared library if it was built using the
6008 -Bsymbolic linker option.
6010 * When the Text User Interface (TUI) is not configured, GDB will now
6011 recognize the -tui command-line option and print a message that the TUI
6014 * The GDB remote stub, gdbserver, now has lower overhead for high
6015 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6017 * GDB for MIPS targets now autodetects whether a remote target provides
6018 32-bit or 64-bit register values.
6020 * Support for C++ member pointers has been improved.
6022 * GDB now understands XML target descriptions, which specify the
6023 target's overall architecture. GDB can read a description from
6024 a local file or over the remote serial protocol.
6026 * Vectors of single-byte data use a new integer type which is not
6027 automatically displayed as character or string data.
6029 * The /s format now works with the print command. It displays
6030 arrays of single-byte integers and pointers to single-byte integers
6033 * Target descriptions can now describe target-specific registers,
6034 for architectures which have implemented the support (currently
6035 only ARM, M68K, and MIPS).
6037 * GDB and the GDB remote stub, gdbserver, now support the XScale
6040 * The GDB remote stub, gdbserver, has been updated to support
6041 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6042 has been rewritten to use the standard GDB remote protocol.
6044 * GDB can now step into C++ functions which are called through thunks.
6046 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6048 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6049 layout. It also supports a TextSeg= and DataSeg= response when only
6050 segment base addresses (rather than offsets) are available.
6052 * The /i format now outputs any trailing branch delay slot instructions
6053 immediately following the last instruction within the count specified.
6055 * The GDB remote protocol "T" stop reply packet now supports a
6056 "library" response. Combined with the new "qXfer:libraries:read"
6057 packet, this response allows GDB to debug shared libraries on targets
6058 where the operating system manages the list of loaded libraries (e.g.
6059 Windows and SymbianOS).
6061 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6062 (DLLs) on Windows and Windows CE targets.
6064 * GDB now supports a faster verification that a .debug file matches its binary
6065 according to its build-id signature, if the signature is present.
6071 Enable or disable hardware flow control (RTS/CTS) on the serial port
6072 when debugging using remote targets.
6074 set mem inaccessible-by-default
6075 show mem inaccessible-by-default
6076 If the target supplies a memory map, for instance via the remote
6077 protocol's "qXfer:memory-map:read" packet, setting this variable
6078 prevents GDB from accessing memory outside the memory map. This
6079 is useful for targets with memory mapped registers or which react
6080 badly to accesses of unmapped address space.
6082 set breakpoint auto-hw
6083 show breakpoint auto-hw
6084 If the target supplies a memory map, for instance via the remote
6085 protocol's "qXfer:memory-map:read" packet, setting this variable
6086 lets GDB use hardware breakpoints automatically for memory regions
6087 where it can not use software breakpoints. This covers both the
6088 "break" command and internal breakpoints used for other commands
6089 including "next" and "finish".
6092 catch exception unhandled
6093 Stop the program execution when Ada exceptions are raised.
6096 Stop the program execution when an Ada assertion failed.
6100 Set an alternate system root for target files. This is a more
6101 general version of "set solib-absolute-prefix", which is now
6102 an alias to "set sysroot".
6105 Provide extended SPU facility status information. This set of
6106 commands is available only when debugging the Cell/B.E. SPU
6109 * New native configurations
6111 OpenBSD/sh sh*-*openbsd*
6114 unset tdesc filename
6116 Use the specified local file as an XML target description, and do
6117 not query the target for its built-in description.
6121 OpenBSD/sh sh*-*-openbsd*
6122 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6123 Toshiba Media Processor mep-elf
6125 * New remote packets
6128 Ignore the specified signals; pass them directly to the debugged program
6129 without stopping other threads or reporting them to GDB.
6131 qXfer:features:read:
6132 Read an XML target description from the target, which describes its
6137 Read or write contents of an spufs file on the target system. These
6138 packets are available only on the Cell/B.E. SPU architecture.
6140 qXfer:libraries:read:
6141 Report the loaded shared libraries. Combined with new "T" packet
6142 response, this packet allows GDB to debug shared libraries on
6143 targets where the operating system manages the list of loaded
6144 libraries (e.g. Windows and SymbianOS).
6148 Support for these obsolete configurations has been removed.
6156 i[34567]86-*-lynxos*
6157 i[34567]86-*-netware*
6158 i[34567]86-*-sco3.2v5*
6159 i[34567]86-*-sco3.2v4*
6161 i[34567]86-*-sysv4.2*
6164 i[34567]86-*-unixware2*
6165 i[34567]86-*-unixware*
6174 * Other removed features
6181 Various m68k-only ROM monitors.
6188 Various Renesas ROM monitors and debugging interfaces for SH and
6193 Support for a Macraigor serial interface to on-chip debugging.
6194 GDB does not directly support the newer parallel or USB
6199 A debug information format. The predecessor to DWARF 2 and
6200 DWARF 3, which are still supported.
6202 Support for the HP aCC compiler on HP-UX/PA-RISC
6204 SOM-encapsulated symbolic debugging information, automatic
6205 invocation of pxdb, and the aCC custom C++ ABI. This does not
6206 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6207 with aCC can still be debugged on an assembly level.
6209 MIPS ".pdr" sections
6211 A MIPS-specific format used to describe stack frame layout
6212 in debugging information.
6216 GDB could work with an older version of Guile to debug
6217 the interpreter and Scheme programs running in it.
6219 set mips stack-arg-size
6220 set mips saved-gpreg-size
6222 Use "set mips abi" to control parameter passing for MIPS.
6224 *** Changes in GDB 6.6
6229 Cell Broadband Engine SPU spu-elf
6231 * GDB can now be configured as a cross-debugger targeting native Windows
6232 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6233 running on a Windows system over TCP/IP to debug Windows programs.
6235 * The GDB remote stub, gdbserver, has been updated to support Windows and
6236 Cygwin debugging. Both single-threaded and multi-threaded programs are
6239 * The "set trust-readonly-sections" command works again. This command was
6240 broken in GDB 6.3, 6.4, and 6.5.
6242 * The "load" command now supports writing to flash memory, if the remote
6243 stub provides the required support.
6245 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6246 longer requires symbolic debug information (e.g. DWARF-2).
6251 unset substitute-path
6252 show substitute-path
6253 Manage a list of substitution rules that GDB uses to rewrite the name
6254 of the directories where the sources are located. This can be useful
6255 for instance when the sources were moved to a different location
6256 between compilation and debugging.
6260 Print each CLI command as it is executed. Each command is prefixed with
6261 a number of `+' symbols representing the nesting depth.
6262 The source command now has a `-v' option to enable the same feature.
6266 The ARM Demon monitor support (RDP protocol, "target rdp").
6268 Kernel Object Display, an embedded debugging feature which only worked with
6269 an obsolete version of Cisco IOS.
6271 The 'set download-write-size' and 'show download-write-size' commands.
6273 * New remote packets
6276 Tell a stub about GDB client features, and request remote target features.
6277 The first feature implemented is PacketSize, which allows the target to
6278 specify the size of packets it can handle - to minimize the number of
6279 packets required and improve performance when connected to a remote
6283 Fetch an OS auxilliary vector from the remote stub. This packet is a
6284 more efficient replacement for qPart:auxv:read.
6286 qXfer:memory-map:read:
6287 Fetch a memory map from the remote stub, including information about
6288 RAM, ROM, and flash memory devices.
6293 Erase and program a flash memory device.
6295 * Removed remote packets
6298 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6299 used it, and only gdbserver implemented it.
6301 *** Changes in GDB 6.5
6305 Renesas M32C/M16C m32c-elf
6307 Morpho Technologies ms1 ms1-elf
6311 init-if-undefined Initialize a convenience variable, but
6312 only if it doesn't already have a value.
6314 The following commands are presently only implemented for native GNU/Linux:
6316 checkpoint Save a snapshot of the program state.
6318 restart <n> Return the program state to a
6319 previously saved state.
6321 info checkpoints List currently saved checkpoints.
6323 delete-checkpoint <n> Delete a previously saved checkpoint.
6325 set|show detach-on-fork Tell gdb whether to detach from a newly
6326 forked process, or to keep debugging it.
6328 info forks List forks of the user program that
6329 are available to be debugged.
6331 fork <n> Switch to debugging one of several
6332 forks of the user program that are
6333 available to be debugged.
6335 delete-fork <n> Delete a fork from the list of forks
6336 that are available to be debugged (and
6337 kill the forked process).
6339 detach-fork <n> Delete a fork from the list of forks
6340 that are available to be debugged (and
6341 allow the process to continue).
6345 Morpho Technologies ms2 ms1-elf
6347 * Improved Windows host support
6349 GDB now builds as a cross debugger hosted on i686-mingw32, including
6350 native console support, and remote communications using either
6351 network sockets or serial ports.
6353 * Improved Modula-2 language support
6355 GDB can now print most types in the Modula-2 syntax. This includes:
6356 basic types, set types, record types, enumerated types, range types,
6357 pointer types and ARRAY types. Procedure var parameters are correctly
6358 printed and hexadecimal addresses and character constants are also
6359 written in the Modula-2 syntax. Best results can be obtained by using
6360 GNU Modula-2 together with the -gdwarf-2 command line option.
6364 The ARM rdi-share module.
6366 The Netware NLM debug server.
6368 *** Changes in GDB 6.4
6370 * New native configurations
6372 OpenBSD/arm arm*-*-openbsd*
6373 OpenBSD/mips64 mips64-*-openbsd*
6377 Morpho Technologies ms1 ms1-elf
6379 * New command line options
6381 --batch-silent As for --batch, but totally silent.
6382 --return-child-result The debugger will exist with the same value
6383 the child (debugged) program exited with.
6384 --eval-command COMMAND, -ex COMMAND
6385 Execute a single GDB CLI command. This may be
6386 specified multiple times and in conjunction
6387 with the --command (-x) option.
6389 * Deprecated commands removed
6391 The following commands, that were deprecated in 2000, have been
6395 set|show arm disassembly-flavor set|show arm disassembler
6396 othernames set arm disassembler
6397 set|show remotedebug set|show debug remote
6398 set|show archdebug set|show debug arch
6399 set|show eventdebug set|show debug event
6402 * New BSD user-level threads support
6404 It is now possible to debug programs using the user-level threads
6405 library on OpenBSD and FreeBSD. Currently supported (target)
6408 FreeBSD/amd64 x86_64-*-freebsd*
6409 FreeBSD/i386 i386-*-freebsd*
6410 OpenBSD/i386 i386-*-openbsd*
6412 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6413 are not yet supported.
6415 * New support for Matsushita MN10300 w/sim added
6416 (Work in progress). mn10300-elf.
6418 * REMOVED configurations and files
6420 VxWorks and the XDR protocol *-*-vxworks
6421 Motorola MCORE mcore-*-*
6422 National Semiconductor NS32000 ns32k-*-*
6424 * New "set print array-indexes" command
6426 After turning this setting "on", GDB prints the index of each element
6427 when displaying arrays. The default is "off" to preserve the previous
6430 * VAX floating point support
6432 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6434 * User-defined command support
6436 In addition to using $arg0..$arg9 for argument passing, it is now possible
6437 to use $argc to determine now many arguments have been passed. See the
6438 section on user-defined commands in the user manual for more information.
6440 *** Changes in GDB 6.3:
6442 * New command line option
6444 GDB now accepts -l followed by a number to set the timeout for remote
6447 * GDB works with GCC -feliminate-dwarf2-dups
6449 GDB now supports a more compact representation of DWARF-2 debug
6450 information using DW_FORM_ref_addr references. These are produced
6451 by GCC with the option -feliminate-dwarf2-dups and also by some
6452 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6453 to use -feliminate-dwarf2-dups.
6455 * Internationalization
6457 When supported by the host system, GDB will be built with
6458 internationalization (libintl). The task of marking up the sources is
6459 continued, we're looking forward to our first translation.
6463 Initial support for debugging programs compiled with the GNAT
6464 implementation of the Ada programming language has been integrated
6465 into GDB. In this release, support is limited to expression evaluation.
6467 * New native configurations
6469 GNU/Linux/m32r m32r-*-linux-gnu
6473 GDB's remote protocol now includes support for the 'p' packet. This
6474 packet is used to fetch individual registers from a remote inferior.
6476 * END-OF-LIFE registers[] compatibility module
6478 GDB's internal register infrastructure has been completely rewritten.
6479 The new infrastructure making possible the implementation of key new
6480 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6483 GDB 6.3 will be the last release to include the registers[]
6484 compatibility module that allowed out-of-date configurations to
6485 continue to work. This change directly impacts the following
6495 powerpc bdm protocol
6497 Unless there is activity to revive these configurations, they will be
6498 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6500 * OBSOLETE configurations and files
6502 Configurations that have been declared obsolete in this release have
6503 been commented out. Unless there is activity to revive these
6504 configurations, the next release of GDB will have their sources
6505 permanently REMOVED.
6514 *** Changes in GDB 6.2.1:
6516 * MIPS `break main; run' gave an heuristic-fence-post warning
6518 When attempting to run even a simple program, a warning about
6519 heuristic-fence-post being hit would be reported. This problem has
6522 * MIPS IRIX 'long double' crashed GDB
6524 When examining a long double variable, GDB would get a segmentation
6525 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6526 IRIX long double values).
6530 A bug in the VAX stack code was causing problems with the "next"
6531 command. This problem has been fixed.
6533 *** Changes in GDB 6.2:
6535 * Fix for ``many threads''
6537 On GNU/Linux systems that use the NPTL threads library, a program
6538 rapidly creating and deleting threads would confuse GDB leading to the
6541 ptrace: No such process.
6542 thread_db_get_info: cannot get thread info: generic error
6544 This problem has been fixed.
6546 * "-async" and "-noasync" options removed.
6548 Support for the broken "-noasync" option has been removed (it caused
6551 * New ``start'' command.
6553 This command runs the program until the beginning of the main procedure.
6555 * New BSD Kernel Data Access Library (libkvm) interface
6557 Using ``target kvm'' it is now possible to debug kernel core dumps and
6558 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6559 platforms. Currently supported (native-only) configurations are:
6561 FreeBSD/amd64 x86_64-*-freebsd*
6562 FreeBSD/i386 i?86-*-freebsd*
6563 NetBSD/i386 i?86-*-netbsd*
6564 NetBSD/m68k m68*-*-netbsd*
6565 NetBSD/sparc sparc-*-netbsd*
6566 OpenBSD/amd64 x86_64-*-openbsd*
6567 OpenBSD/i386 i?86-*-openbsd*
6568 OpenBSD/m68k m68*-openbsd*
6569 OpenBSD/sparc sparc-*-openbsd*
6571 * Signal trampoline code overhauled
6573 Many generic problems with GDB's signal handling code have been fixed.
6574 These include: backtraces through non-contiguous stacks; recognition
6575 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6576 call; backtrace through a signal trampoline; step into and out of
6577 signal handlers; and single-stepping in the signal trampoline.
6579 Please note that kernel bugs are a limiting factor here. These
6580 features have been shown to work on an s390 GNU/Linux system that
6581 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6583 * Cygwin support for DWARF 2 added.
6585 * New native configurations
6587 GNU/Linux/hppa hppa*-*-linux*
6588 OpenBSD/hppa hppa*-*-openbsd*
6589 OpenBSD/m68k m68*-*-openbsd*
6590 OpenBSD/m88k m88*-*-openbsd*
6591 OpenBSD/powerpc powerpc-*-openbsd*
6592 NetBSD/vax vax-*-netbsd*
6593 OpenBSD/vax vax-*-openbsd*
6595 * END-OF-LIFE frame compatibility module
6597 GDB's internal frame infrastructure has been completely rewritten.
6598 The new infrastructure making it possible to support key new features
6599 including DWARF 2 Call Frame Information. To aid in the task of
6600 migrating old configurations to this new infrastructure, a
6601 compatibility module, that allowed old configurations to continue to
6602 work, was also included.
6604 GDB 6.2 will be the last release to include this frame compatibility
6605 module. This change directly impacts the following configurations:
6615 Unless there is activity to revive these configurations, they will be
6616 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6618 * REMOVED configurations and files
6620 Sun 3, running SunOS 3 m68*-*-sunos3*
6621 Sun 3, running SunOS 4 m68*-*-sunos4*
6622 Sun 2, running SunOS 3 m68000-*-sunos3*
6623 Sun 2, running SunOS 4 m68000-*-sunos4*
6624 Motorola 680x0 running LynxOS m68*-*-lynxos*
6625 AT&T 3b1/Unix pc m68*-att-*
6626 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6627 decstation mips-dec-* mips-little-*
6628 riscos mips-*-riscos* mips-*-sysv*
6629 sonymips mips-sony-*
6630 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6632 *** Changes in GDB 6.1.1:
6634 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6636 The TUI (Text-mode User Interface) is now built as part of a default
6637 GDB configuration. It is enabled by either selecting the TUI with the
6638 command line option "-i=tui" or by running the separate "gdbtui"
6639 program. For more information on the TUI, see the manual "Debugging
6642 * Pending breakpoint support (also included in GDB 6.1)
6644 Support has been added to allow you to specify breakpoints in shared
6645 libraries that have not yet been loaded. If a breakpoint location
6646 cannot be found, and the "breakpoint pending" option is set to auto,
6647 GDB queries you if you wish to make the breakpoint pending on a future
6648 shared-library load. If and when GDB resolves the breakpoint symbol,
6649 the pending breakpoint is removed as one or more regular breakpoints
6652 Pending breakpoints are very useful for GCJ Java debugging.
6654 * Fixed ISO-C build problems
6656 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6657 non ISO-C code that stopped them being built using a more strict ISO-C
6658 compiler (e.g., IBM's C compiler).
6660 * Fixed build problem on IRIX 5
6662 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6663 wasn't able to compile compile on an IRIX 5 system.
6665 * Added execute permission to gdb/gdbserver/configure
6667 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6668 permission. This bug would cause configure to fail on a number of
6669 systems (Solaris, IRIX). Ref: server/519.
6671 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6673 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6674 has been updated to use constant array sizes.
6676 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6678 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6679 its generated DWARF Call Frame Info. This encoding was causing GDB to
6680 panic, that panic has been fixed. Ref: gdb/1628.
6682 * Fixed a problem when examining parameters in shared library code.
6684 When examining parameters in optimized shared library code generated
6685 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6686 not available''. GDB now correctly displays the variable's value.
6688 *** Changes in GDB 6.1:
6690 * Removed --with-mmalloc
6692 Support for the mmalloc memory manager has been removed, as it
6693 conflicted with the internal gdb byte cache.
6695 * Changes in AMD64 configurations
6697 The AMD64 target now includes the %cs and %ss registers. As a result
6698 the AMD64 remote protocol has changed; this affects the floating-point
6699 and SSE registers. If you rely on those registers for your debugging,
6700 you should upgrade gdbserver on the remote side.
6702 * Revised SPARC target
6704 The SPARC target has been completely revised, incorporating the
6705 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6706 support for LynxOS and SunOS 4 has been dropped. Calling functions
6707 from within GDB on operating systems with a non-executable stack
6708 (Solaris, OpenBSD) now works.
6712 GDB has a new C++ demangler which does a better job on the mangled
6713 names generated by current versions of g++. It also runs faster, so
6714 with this and other changes gdb should now start faster on large C++
6717 * DWARF 2 Location Expressions
6719 GDB support for location expressions has been extended to support function
6720 arguments and frame bases. Older versions of GDB could crash when they
6723 * C++ nested types and namespaces
6725 GDB's support for nested types and namespaces in C++ has been
6726 improved, especially if you use the DWARF 2 debugging format. (This
6727 is the default for recent versions of GCC on most platforms.)
6728 Specifically, if you have a class "Inner" defined within a class or
6729 namespace "Outer", then GDB realizes that the class's name is
6730 "Outer::Inner", not simply "Inner". This should greatly reduce the
6731 frequency of complaints about not finding RTTI symbols. In addition,
6732 if you are stopped at inside of a function defined within a namespace,
6733 GDB modifies its name lookup accordingly.
6735 * New native configurations
6737 NetBSD/amd64 x86_64-*-netbsd*
6738 OpenBSD/amd64 x86_64-*-openbsd*
6739 OpenBSD/alpha alpha*-*-openbsd*
6740 OpenBSD/sparc sparc-*-openbsd*
6741 OpenBSD/sparc64 sparc64-*-openbsd*
6743 * New debugging protocols
6745 M32R with SDI protocol m32r-*-elf*
6747 * "set prompt-escape-char" command deleted.
6749 The command "set prompt-escape-char" has been deleted. This command,
6750 and its very obscure effect on GDB's prompt, was never documented,
6751 tested, nor mentioned in the NEWS file.
6753 * OBSOLETE configurations and files
6755 Configurations that have been declared obsolete in this release have
6756 been commented out. Unless there is activity to revive these
6757 configurations, the next release of GDB will have their sources
6758 permanently REMOVED.
6760 Sun 3, running SunOS 3 m68*-*-sunos3*
6761 Sun 3, running SunOS 4 m68*-*-sunos4*
6762 Sun 2, running SunOS 3 m68000-*-sunos3*
6763 Sun 2, running SunOS 4 m68000-*-sunos4*
6764 Motorola 680x0 running LynxOS m68*-*-lynxos*
6765 AT&T 3b1/Unix pc m68*-att-*
6766 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6767 decstation mips-dec-* mips-little-*
6768 riscos mips-*-riscos* mips-*-sysv*
6769 sonymips mips-sony-*
6770 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6772 * REMOVED configurations and files
6774 SGI Irix-4.x mips-sgi-irix4 or iris4
6775 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6776 Z8000 simulator z8k-zilog-none or z8ksim
6777 Matsushita MN10200 w/simulator mn10200-*-*
6778 H8/500 simulator h8500-hitachi-hms or h8500hms
6779 HP/PA running BSD hppa*-*-bsd*
6780 HP/PA running OSF/1 hppa*-*-osf*
6781 HP/PA Pro target hppa*-*-pro*
6782 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6783 386BSD i[3456]86-*-bsd*
6784 Sequent family i[3456]86-sequent-sysv4*
6785 i[3456]86-sequent-sysv*
6786 i[3456]86-sequent-bsd*
6787 SPARC running LynxOS sparc-*-lynxos*
6788 SPARC running SunOS 4 sparc-*-sunos4*
6789 Tsqware Sparclet sparclet-*-*
6790 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6792 *** Changes in GDB 6.0:
6796 Support for debugging the Objective-C programming language has been
6797 integrated into GDB.
6799 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6801 DWARF 2's Call Frame Information makes available compiler generated
6802 information that more exactly describes the program's run-time stack.
6803 By using this information, GDB is able to provide more robust stack
6806 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6807 have been updated to use a new backtrace mechanism which includes
6808 DWARF 2 CFI support.
6812 GDB's remote protocol has been extended to include support for hosted
6813 file I/O (where the remote target uses GDB's file system). See GDB's
6814 remote protocol documentation for details.
6816 * All targets using the new architecture framework.
6818 All of GDB's targets have been updated to use the new internal
6819 architecture framework. The way is now open for future GDB releases
6820 to include cross-architecture native debugging support (i386 on amd64,
6823 * GNU/Linux's Thread Local Storage (TLS)
6825 GDB now includes support for for the GNU/Linux implementation of
6826 per-thread variables.
6828 * GNU/Linux's Native POSIX Thread Library (NPTL)
6830 GDB's thread code has been updated to work with either the new
6831 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6833 * Separate debug info.
6835 GDB, in conjunction with BINUTILS, now supports a mechanism for
6836 automatically loading debug information from a separate file. Instead
6837 of shipping full debug and non-debug versions of system libraries,
6838 system integrators can now instead ship just the stripped libraries
6839 and optional debug files.
6841 * DWARF 2 Location Expressions
6843 DWARF 2 Location Expressions allow the compiler to more completely
6844 describe the location of variables (even in optimized code) to the
6847 GDB now includes preliminary support for location expressions (support
6848 for DW_OP_piece is still missing).
6852 A number of long standing bugs that caused GDB to die while starting a
6853 Java application have been fixed. GDB's Java support is now
6854 considered "useable".
6856 * GNU/Linux support for fork, vfork, and exec.
6858 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6859 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6862 * GDB supports logging output to a file
6864 There are two new commands, "set logging" and "show logging", which can be
6865 used to capture GDB's output to a file.
6867 * The meaning of "detach" has changed for gdbserver
6869 The "detach" command will now resume the application, as documented. To
6870 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6873 * d10v, m68hc11 `regs' command deprecated
6875 The `info registers' command has been updated so that it displays the
6876 registers using a format identical to the old `regs' command.
6880 A new command, "maint set profile on/off", has been added. This command can
6881 be used to enable or disable profiling while running GDB, to profile a
6882 session or a set of commands. In addition there is a new configure switch,
6883 "--enable-profiling", which will cause GDB to be compiled with profiling
6884 data, for more informative profiling results.
6886 * Default MI syntax changed to "mi2".
6888 The default MI (machine interface) syntax, enabled by the command line
6889 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6890 "mi1", can be enabled by specifying the option "-i=mi1".
6892 Support for the original "mi0" syntax (included in GDB 5.0) has been
6895 Fix for gdb/192: removed extraneous space when displaying frame level.
6896 Fix for gdb/672: update changelist is now output in mi list format.
6897 Fix for gdb/702: a -var-assign that updates the value now shows up
6898 in a subsequent -var-update.
6900 * New native configurations.
6902 FreeBSD/amd64 x86_64-*-freebsd*
6904 * Multi-arched targets.
6906 HP/PA HPUX11 hppa*-*-hpux*
6907 Renesas M32R/D w/simulator m32r-*-elf*
6909 * OBSOLETE configurations and files
6911 Configurations that have been declared obsolete in this release have
6912 been commented out. Unless there is activity to revive these
6913 configurations, the next release of GDB will have their sources
6914 permanently REMOVED.
6916 Z8000 simulator z8k-zilog-none or z8ksim
6917 Matsushita MN10200 w/simulator mn10200-*-*
6918 H8/500 simulator h8500-hitachi-hms or h8500hms
6919 HP/PA running BSD hppa*-*-bsd*
6920 HP/PA running OSF/1 hppa*-*-osf*
6921 HP/PA Pro target hppa*-*-pro*
6922 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6923 Sequent family i[3456]86-sequent-sysv4*
6924 i[3456]86-sequent-sysv*
6925 i[3456]86-sequent-bsd*
6926 Tsqware Sparclet sparclet-*-*
6927 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6929 * REMOVED configurations and files
6932 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6933 IBM AIX PS/2 i[3456]86-*-aix
6934 i386 running Mach 3.0 i[3456]86-*-mach3*
6935 i386 running Mach i[3456]86-*-mach*
6936 i386 running OSF/1 i[3456]86-*osf1mk*
6937 HP/Apollo 68k Family m68*-apollo*-sysv*,
6939 m68*-hp-bsd*, m68*-hp-hpux*
6940 Argonaut Risc Chip (ARC) arc-*-*
6941 Mitsubishi D30V d30v-*-*
6942 Fujitsu FR30 fr30-*-elf*
6943 OS/9000 i[34]86-*-os9k
6944 I960 with MON960 i960-*-coff
6946 * MIPS $fp behavior changed
6948 The convenience variable $fp, for the MIPS, now consistently returns
6949 the address of the current frame's base. Previously, depending on the
6950 context, $fp could refer to either $sp or the current frame's base
6951 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6952 The GNU Source-Level Debugger''.
6954 *** Changes in GDB 5.3:
6956 * GNU/Linux shared library multi-threaded performance improved.
6958 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6959 `/proc', in preference to `ptrace' for memory reads. This may result
6960 in an improvement in the start-up time of multi-threaded, shared
6961 library applications when run under GDB. One GDB user writes: ``loads
6962 shared libs like mad''.
6964 * ``gdbserver'' now supports multi-threaded applications on some targets
6966 Support for debugging multi-threaded applications which use
6967 the GNU/Linux LinuxThreads package has been added for
6968 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6969 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6971 * GDB now supports C/C++ preprocessor macros.
6973 GDB now expands preprocessor macro invocations in C/C++ expressions,
6974 and provides various commands for showing macro definitions and how
6977 The new command `macro expand EXPRESSION' expands any macro
6978 invocations in expression, and shows the result.
6980 The new command `show macro MACRO-NAME' shows the definition of the
6981 macro named MACRO-NAME, and where it was defined.
6983 Most compilers don't include information about macros in the debugging
6984 information by default. In GCC 3.1, for example, you need to compile
6985 your program with the options `-gdwarf-2 -g3'. If the macro
6986 information is present in the executable, GDB will read it.
6988 * Multi-arched targets.
6990 DEC Alpha (partial) alpha*-*-*
6991 DEC VAX (partial) vax-*-*
6993 National Semiconductor NS32000 (partial) ns32k-*-*
6994 Motorola 68000 (partial) m68k-*-*
6995 Motorola MCORE mcore-*-*
6999 Fujitsu FRV architecture added by Red Hat frv*-*-*
7002 * New native configurations
7004 Alpha NetBSD alpha*-*-netbsd*
7005 SH NetBSD sh*-*-netbsdelf*
7006 MIPS NetBSD mips*-*-netbsd*
7007 UltraSPARC NetBSD sparc64-*-netbsd*
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 Mitsubishi D30V d30v-*-*
7017 OS/9000 i[34]86-*-os9k
7018 IBM AIX PS/2 i[3456]86-*-aix
7019 Fujitsu FR30 fr30-*-elf*
7020 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7021 Argonaut Risc Chip (ARC) arc-*-*
7022 i386 running Mach 3.0 i[3456]86-*-mach3*
7023 i386 running Mach i[3456]86-*-mach*
7024 i386 running OSF/1 i[3456]86-*osf1mk*
7025 HP/Apollo 68k Family m68*-apollo*-sysv*,
7027 m68*-hp-bsd*, m68*-hp-hpux*
7028 I960 with MON960 i960-*-coff
7030 * OBSOLETE languages
7032 CHILL, a Pascal like language used by telecommunications companies.
7034 * REMOVED configurations and files
7036 AMD 29k family via UDI a29k-amd-udi, udi29k
7037 A29K VxWorks a29k-*-vxworks
7038 AMD 29000 embedded, using EBMON a29k-none-none
7039 AMD 29000 embedded with COFF a29k-none-coff
7040 AMD 29000 embedded with a.out a29k-none-aout
7042 testsuite/gdb.hp/gdb.threads-hp/ directory
7044 * New command "set max-user-call-depth <nnn>"
7046 This command allows the user to limit the call depth of user-defined
7047 commands. The default is 1024.
7049 * Changes in FreeBSD/i386 native debugging.
7051 Support for the "generate-core-file" has been added.
7053 * New commands "dump", "append", and "restore".
7055 These commands allow data to be copied from target memory
7056 to a bfd-format or binary file (dump and append), and back
7057 from a file into memory (restore).
7059 * Improved "next/step" support on multi-processor Alpha Tru64.
7061 The previous single-step mechanism could cause unpredictable problems,
7062 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7063 of a software single-step mechanism prevents this.
7065 *** Changes in GDB 5.2.1:
7073 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7074 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7075 Fix, by Joel Brobecker imported from mainline.
7077 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7078 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7079 Fix, by Fred Fish, imported from mainline.
7081 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7082 Surprisingly enough, it works now.
7083 By Michal Ludvig, imported from mainline.
7085 i386 hardware watchpoint support:
7086 avoid misses on second run for some targets.
7087 By Pierre Muller, imported from mainline.
7089 *** Changes in GDB 5.2:
7091 * New command "set trust-readonly-sections on[off]".
7093 This command is a hint that tells gdb that read-only sections
7094 really are read-only (ie. that their contents will not change).
7095 In this mode, gdb will go to the object file rather than the
7096 target to read memory from read-only sections (such as ".text").
7097 This can be a significant performance improvement on some
7098 (notably embedded) targets.
7100 * New command "generate-core-file" (or "gcore").
7102 This new gdb command allows the user to drop a core file of the child
7103 process state at any time. So far it's been implemented only for
7104 GNU/Linux and Solaris, but should be relatively easily ported to other
7105 hosts. Argument is core file name (defaults to core.<pid>).
7107 * New command line option
7109 GDB now accepts --pid or -p followed by a process id.
7111 * Change in command line behavior -- corefiles vs. process ids.
7113 There is a subtle behavior in the way in which GDB handles
7114 command line arguments. The first non-flag argument is always
7115 a program to debug, but the second non-flag argument may either
7116 be a corefile or a process id. Previously, GDB would attempt to
7117 open the second argument as a corefile, and if that failed, would
7118 issue a superfluous error message and then attempt to attach it as
7119 a process. Now, if the second argument begins with a non-digit,
7120 it will be treated as a corefile. If it begins with a digit,
7121 GDB will attempt to attach it as a process, and if no such process
7122 is found, will then attempt to open it as a corefile.
7124 * Changes in ARM configurations.
7126 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7127 configuration is fully multi-arch.
7129 * New native configurations
7131 ARM NetBSD arm*-*-netbsd*
7132 x86 OpenBSD i[3456]86-*-openbsd*
7133 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7134 Sparc64 running FreeBSD sparc64-*-freebsd*
7138 Sanyo XStormy16 xstormy16-elf
7140 * OBSOLETE configurations and files
7142 Configurations that have been declared obsolete in this release have
7143 been commented out. Unless there is activity to revive these
7144 configurations, the next release of GDB will have their sources
7145 permanently REMOVED.
7147 AMD 29k family via UDI a29k-amd-udi, udi29k
7148 A29K VxWorks a29k-*-vxworks
7149 AMD 29000 embedded, using EBMON a29k-none-none
7150 AMD 29000 embedded with COFF a29k-none-coff
7151 AMD 29000 embedded with a.out a29k-none-aout
7153 testsuite/gdb.hp/gdb.threads-hp/ directory
7155 * REMOVED configurations and files
7157 TI TMS320C80 tic80-*-*
7159 PowerPC Solaris powerpcle-*-solaris*
7160 PowerPC Windows NT powerpcle-*-cygwin32
7161 PowerPC Netware powerpc-*-netware*
7162 Harris/CXUX m88k m88*-harris-cxux*
7163 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7164 ns32k-utek-sysv* ns32k-utek-*
7165 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7166 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7167 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7168 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7169 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7171 * Changes to command line processing
7173 The new `--args' feature can be used to specify command-line arguments
7174 for the inferior from gdb's command line.
7176 * Changes to key bindings
7178 There is a new `operate-and-get-next' function bound to `C-o'.
7180 *** Changes in GDB 5.1.1
7182 Fix compile problem on DJGPP.
7184 Fix a problem with floating-point registers on the i386 being
7187 Fix to stop GDB crashing on .debug_str debug info.
7189 Numerous documentation fixes.
7191 Numerous testsuite fixes.
7193 *** Changes in GDB 5.1:
7195 * New native configurations
7197 Alpha FreeBSD alpha*-*-freebsd*
7198 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7199 MIPS GNU/Linux mips*-*-linux*
7200 MIPS SGI Irix 6.x mips*-sgi-irix6*
7201 ia64 AIX ia64-*-aix*
7202 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7206 Motorola 68HC11 and 68HC12 m68hc11-elf
7208 UltraSparc running GNU/Linux sparc64-*-linux*
7210 * OBSOLETE configurations and files
7212 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7213 Harris/CXUX m88k m88*-harris-cxux*
7214 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7215 ns32k-utek-sysv* ns32k-utek-*
7216 TI TMS320C80 tic80-*-*
7218 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7219 PowerPC Solaris powerpcle-*-solaris*
7220 PowerPC Windows NT powerpcle-*-cygwin32
7221 PowerPC Netware powerpc-*-netware*
7222 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7223 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7224 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7225 Apple Macintosh (MPW) host N/A
7227 stuff.c (Program to stuff files into a specially prepared space in kdb)
7228 kdb-start.c (Main loop for the standalone kernel debugger)
7230 Configurations that have been declared obsolete in this release have
7231 been commented out. Unless there is activity to revive these
7232 configurations, the next release of GDB will have their sources
7233 permanently REMOVED.
7235 * REMOVED configurations and files
7237 Altos 3068 m68*-altos-*
7238 Convex c1-*-*, c2-*-*
7240 ARM RISCix arm-*-* (as host)
7244 * GDB has been converted to ISO C.
7246 GDB's source code has been converted to ISO C. In particular, the
7247 sources are fully protoized, and rely on standard headers being
7252 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7254 * The MI enabled by default.
7256 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7257 revised and enabled by default. Packages which use GDB as a debugging
7258 engine behind a UI or another front end are encouraged to switch to
7259 using the GDB/MI interface, instead of the old annotations interface
7260 which is now deprecated.
7262 * Support for debugging Pascal programs.
7264 GDB now includes support for debugging Pascal programs. The following
7265 main features are supported:
7267 - Pascal-specific data types such as sets;
7269 - automatic recognition of Pascal sources based on file-name
7272 - Pascal-style display of data types, variables, and functions;
7274 - a Pascal expression parser.
7276 However, some important features are not yet supported.
7278 - Pascal string operations are not supported at all;
7280 - there are some problems with boolean types;
7282 - Pascal type hexadecimal constants are not supported
7283 because they conflict with the internal variables format;
7285 - support for Pascal objects and classes is not full yet;
7287 - unlike Pascal, GDB is case-sensitive for symbol names.
7289 * Changes in completion.
7291 Commands such as `shell', `run' and `set args', which pass arguments
7292 to inferior programs, now complete on file names, similar to what
7293 users expect at the shell prompt.
7295 Commands which accept locations, such as `disassemble', `print',
7296 `breakpoint', `until', etc. now complete on filenames as well as
7297 program symbols. Thus, if you type "break foob TAB", and the source
7298 files linked into the programs include `foobar.c', that file name will
7299 be one of the candidates for completion. However, file names are not
7300 considered for completion after you typed a colon that delimits a file
7301 name from a name of a function in that file, as in "break foo.c:bar".
7303 `set demangle-style' completes on available demangling styles.
7305 * New platform-independent commands:
7307 It is now possible to define a post-hook for a command as well as a
7308 hook that runs before the command. For more details, see the
7309 documentation of `hookpost' in the GDB manual.
7311 * Changes in GNU/Linux native debugging.
7313 Support for debugging multi-threaded programs has been completely
7314 revised for all platforms except m68k and sparc. You can now debug as
7315 many threads as your system allows you to have.
7317 Attach/detach is supported for multi-threaded programs.
7319 Support for SSE registers was added for x86. This doesn't work for
7320 multi-threaded programs though.
7322 * Changes in MIPS configurations.
7324 Multi-arch support is enabled for all MIPS configurations.
7326 GDB can now be built as native debugger on SGI Irix 6.x systems for
7327 debugging n32 executables. (Debugging 64-bit executables is not yet
7330 * Unified support for hardware watchpoints in all x86 configurations.
7332 Most (if not all) native x86 configurations support hardware-assisted
7333 breakpoints and watchpoints in a unified manner. This support
7334 implements debug register sharing between watchpoints, which allows to
7335 put a virtually infinite number of watchpoints on the same address,
7336 and also supports watching regions up to 16 bytes with several debug
7339 The new maintenance command `maintenance show-debug-regs' toggles
7340 debugging print-outs in functions that insert, remove, and test
7341 watchpoints and hardware breakpoints.
7343 * Changes in the DJGPP native configuration.
7345 New command ``info dos sysinfo'' displays assorted information about
7346 the CPU, OS, memory, and DPMI server.
7348 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7349 display information about segment descriptors stored in GDT, LDT, and
7352 New commands ``info dos pde'' and ``info dos pte'' display entries
7353 from Page Directory and Page Tables (for now works with CWSDPMI only).
7354 New command ``info dos address-pte'' displays the Page Table entry for
7355 a given linear address.
7357 GDB can now pass command lines longer than 126 characters to the
7358 program being debugged (requires an update to the libdbg.a library
7359 which is part of the DJGPP development kit).
7361 DWARF2 debug info is now supported.
7363 It is now possible to `step' and `next' through calls to `longjmp'.
7365 * Changes in documentation.
7367 All GDB documentation was converted to GFDL, the GNU Free
7368 Documentation License.
7370 Tracepoints-related commands are now fully documented in the GDB
7373 TUI, the Text-mode User Interface, is now documented in the manual.
7375 Tracepoints-related commands are now fully documented in the GDB
7378 The "GDB Internals" manual now has an index. It also includes
7379 documentation of `ui_out' functions, GDB coding standards, x86
7380 hardware watchpoints, and memory region attributes.
7382 * GDB's version number moved to ``version.in''
7384 The Makefile variable VERSION has been replaced by the file
7385 ``version.in''. People creating GDB distributions should update the
7386 contents of this file.
7390 GUD support is now a standard part of the EMACS distribution.
7392 *** Changes in GDB 5.0:
7394 * Improved support for debugging FP programs on x86 targets
7396 Unified and much-improved support for debugging floating-point
7397 programs on all x86 targets. In particular, ``info float'' now
7398 displays the FP registers in the same format on all x86 targets, with
7399 greater level of detail.
7401 * Improvements and bugfixes in hardware-assisted watchpoints
7403 It is now possible to watch array elements, struct members, and
7404 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7405 on x86 targets no longer erroneously trigger when the address is
7408 * Improvements in the native DJGPP version of GDB
7410 The distribution now includes all the scripts and auxiliary files
7411 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7412 machines ``out of the box''.
7414 The DJGPP version can now debug programs that use signals. It is
7415 possible to catch signals that happened in the debuggee, deliver
7416 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7417 would kill the program being debugged.) Programs that hook hardware
7418 interrupts (keyboard, timer, etc.) can also be debugged.
7420 It is now possible to debug DJGPP programs that redirect their
7421 standard handles or switch them to raw (as opposed to cooked) mode, or
7422 even close them. The command ``run < foo > bar'' works as expected,
7423 and ``info terminal'' reports useful information about the debuggee's
7424 terminal, including raw/cooked mode, redirection, etc.
7426 The DJGPP version now uses termios functions for console I/O, which
7427 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7430 DOS-style file names with drive letters are now fully supported by
7433 It is now possible to debug DJGPP programs that switch their working
7434 directory. It is also possible to rerun the debuggee any number of
7435 times without restarting GDB; thus, you can use the same setup,
7436 breakpoints, etc. for many debugging sessions.
7438 * New native configurations
7440 ARM GNU/Linux arm*-*-linux*
7441 PowerPC GNU/Linux powerpc-*-linux*
7445 Motorola MCore mcore-*-*
7446 x86 VxWorks i[3456]86-*-vxworks*
7447 PowerPC VxWorks powerpc-*-vxworks*
7448 TI TMS320C80 tic80-*-*
7450 * OBSOLETE configurations
7452 Altos 3068 m68*-altos-*
7453 Convex c1-*-*, c2-*-*
7455 ARM RISCix arm-*-* (as host)
7458 Configurations that have been declared obsolete will be commented out,
7459 but the code will be left in place. If there is no activity to revive
7460 these configurations before the next release of GDB, the sources will
7461 be permanently REMOVED.
7463 * Gould support removed
7465 Support for the Gould PowerNode and NP1 has been removed.
7467 * New features for SVR4
7469 On SVR4 native platforms (such as Solaris), if you attach to a process
7470 without first loading a symbol file, GDB will now attempt to locate and
7471 load symbols from the running process's executable file.
7473 * Many C++ enhancements
7475 C++ support has been greatly improved. Overload resolution now works properly
7476 in almost all cases. RTTI support is on the way.
7478 * Remote targets can connect to a sub-program
7480 A popen(3) style serial-device has been added. This device starts a
7481 sub-process (such as a stand-alone simulator) and then communicates
7482 with that. The sub-program to run is specified using the syntax
7483 ``|<program> <args>'' vis:
7485 (gdb) set remotedebug 1
7486 (gdb) target extended-remote |mn10300-elf-sim program-args
7488 * MIPS 64 remote protocol
7490 A long standing bug in the mips64 remote protocol where by GDB
7491 expected certain 32 bit registers (ex SR) to be transfered as 32
7492 instead of 64 bits has been fixed.
7494 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7495 added to provide backward compatibility with older versions of GDB.
7497 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7499 The command ``set remotebinarydownload'' command has been replaced by
7500 ``set remote X-packet''. Other commands in ``set remote'' family
7501 include ``set remote P-packet''.
7503 * Breakpoint commands accept ranges.
7505 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7506 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7507 ``tracepoint passcount'' also accepts a range of tracepoints.
7509 * ``apropos'' command added.
7511 The ``apropos'' command searches through command names and
7512 documentation strings, printing out matches, making it much easier to
7513 try to find a command that does what you are looking for.
7517 A new machine oriented interface (MI) has been added to GDB. This
7518 interface is designed for debug environments running GDB as a separate
7519 process. This is part of the long term libGDB project. See the
7520 "GDB/MI" chapter of the GDB manual for further information. It can be
7521 enabled by configuring with:
7523 .../configure --enable-gdbmi
7525 *** Changes in GDB-4.18:
7527 * New native configurations
7529 HP-UX 10.20 hppa*-*-hpux10.20
7530 HP-UX 11.x hppa*-*-hpux11.0*
7531 M68K GNU/Linux m68*-*-linux*
7535 Fujitsu FR30 fr30-*-elf*
7536 Intel StrongARM strongarm-*-*
7537 Mitsubishi D30V d30v-*-*
7539 * OBSOLETE configurations
7541 Gould PowerNode, NP1 np1-*-*, pn-*-*
7543 Configurations that have been declared obsolete will be commented out,
7544 but the code will be left in place. If there is no activity to revive
7545 these configurations before the next release of GDB, the sources will
7546 be permanently REMOVED.
7550 As a compatibility experiment, GDB's source files buildsym.h and
7551 buildsym.c have been converted to pure standard C, no longer
7552 containing any K&R compatibility code. We believe that all systems in
7553 use today either come with a standard C compiler, or have a GCC port
7554 available. If this is not true, please report the affected
7555 configuration to bug-gdb@gnu.org immediately. See the README file for
7556 information about getting a standard C compiler if you don't have one
7561 GDB now uses readline 2.2.
7563 * set extension-language
7565 You can now control the mapping between filename extensions and source
7566 languages by using the `set extension-language' command. For instance,
7567 you can ask GDB to treat .c files as C++ by saying
7568 set extension-language .c c++
7569 The command `info extensions' lists all of the recognized extensions
7570 and their associated languages.
7572 * Setting processor type for PowerPC and RS/6000
7574 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7575 you can use the `set processor' command to specify what variant of the
7576 PowerPC family you are debugging. The command
7580 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7581 following PowerPC and RS6000 variants:
7583 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7584 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7586 403GC IBM PowerPC 403GC
7587 505 Motorola PowerPC 505
7588 860 Motorola PowerPC 860 or 850
7589 601 Motorola PowerPC 601
7590 602 Motorola PowerPC 602
7591 603 Motorola/IBM PowerPC 603 or 603e
7592 604 Motorola PowerPC 604 or 604e
7593 750 Motorola/IBM PowerPC 750 or 750
7595 At the moment, this command just tells GDB what to name the
7596 special-purpose processor registers. Since almost all the affected
7597 registers are inaccessible to user-level programs, this command is
7598 only useful for remote debugging in its present form.
7602 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7603 more extensive support for HP-UX. Added features include shared
7604 library support, kernel threads and hardware watchpoints for 11.00,
7605 support for HP's ANSI C and C++ compilers, and a compatibility mode
7606 for xdb and dbx commands.
7610 HP's donation includes the new concept of catchpoints, which is a
7611 generalization of the old catch command. On HP-UX, it is now possible
7612 to catch exec, fork, and vfork, as well as library loading.
7614 This means that the existing catch command has changed; its first
7615 argument now specifies the type of catch to be set up. See the
7616 output of "help catch" for a list of catchpoint types.
7618 * Debugging across forks
7620 On HP-UX, you can choose which process to debug when a fork() happens
7625 HP has donated a curses-based terminal user interface (TUI). To get
7626 it, build with --enable-tui. Although this can be enabled for any
7627 configuration, at present it only works for native HP debugging.
7629 * GDB remote protocol additions
7631 A new protocol packet 'X' that writes binary data is now available.
7632 Default behavior is to try 'X', then drop back to 'M' if the stub
7633 fails to respond. The settable variable `remotebinarydownload'
7634 allows explicit control over the use of 'X'.
7636 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7637 full 64-bit address. The command
7639 set remoteaddresssize 32
7641 can be used to revert to the old behaviour. For existing remote stubs
7642 the change should not be noticed, as the additional address information
7645 In order to assist in debugging stubs, you may use the maintenance
7646 command `packet' to send any text string to the stub. For instance,
7648 maint packet heythere
7650 sends the packet "$heythere#<checksum>". Note that it is very easy to
7651 disrupt a debugging session by sending the wrong packet at the wrong
7654 The compare-sections command allows you to compare section data on the
7655 target to what is in the executable file without uploading or
7656 downloading, by comparing CRC checksums.
7658 * Tracing can collect general expressions
7660 You may now collect general expressions at tracepoints. This requires
7661 further additions to the target-side stub; see tracepoint.c and
7662 doc/agentexpr.texi for further details.
7664 * mask-address variable for Mips
7666 For Mips targets, you may control the zeroing of the upper 32 bits of
7667 a 64-bit address by entering `set mask-address on'. This is mainly
7668 of interest to users of embedded R4xxx and R5xxx processors.
7670 * Higher serial baud rates
7672 GDB's serial code now allows you to specify baud rates 57600, 115200,
7673 230400, and 460800 baud. (Note that your host system may not be able
7674 to achieve all of these rates.)
7678 The i960 configuration now includes an initial implementation of a
7679 builtin simulator, contributed by Jim Wilson.
7682 *** Changes in GDB-4.17:
7684 * New native configurations
7686 Alpha GNU/Linux alpha*-*-linux*
7687 Unixware 2.x i[3456]86-unixware2*
7688 Irix 6.x mips*-sgi-irix6*
7689 PowerPC GNU/Linux powerpc-*-linux*
7690 PowerPC Solaris powerpcle-*-solaris*
7691 Sparc GNU/Linux sparc-*-linux*
7692 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7696 Argonaut Risc Chip (ARC) arc-*-*
7697 Hitachi H8/300S h8300*-*-*
7698 Matsushita MN10200 w/simulator mn10200-*-*
7699 Matsushita MN10300 w/simulator mn10300-*-*
7700 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7701 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7702 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7703 Mitsubishi D10V w/simulator d10v-*-*
7704 Mitsubishi M32R/D w/simulator m32r-*-elf*
7705 Tsqware Sparclet sparclet-*-*
7706 NEC V850 w/simulator v850-*-*
7708 * New debugging protocols
7710 ARM with RDI protocol arm*-*-*
7711 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7712 DDB and LSI variants of PMON protocol mips*-*-*
7713 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7714 PowerPC with SDS protocol powerpc{,le}-*-eabi
7715 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7719 All configurations can now understand and use the DWARF 2 debugging
7720 format. The choice is automatic, if the symbol file contains DWARF 2
7725 GDB now includes basic Java language support. This support is
7726 only useful with Java compilers that produce native machine code.
7728 * solib-absolute-prefix and solib-search-path
7730 For SunOS and SVR4 shared libraries, you may now set the prefix for
7731 loading absolute shared library symbol files, and the search path for
7732 locating non-absolute shared library symbol files.
7734 * Live range splitting
7736 GDB can now effectively debug code for which GCC has performed live
7737 range splitting as part of its optimization. See gdb/doc/LRS for
7738 more details on the expected format of the stabs information.
7742 GDB's support for the GNU Hurd, including thread debugging, has been
7743 updated to work with current versions of the Hurd.
7747 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7748 instruction set. ARM GDB automatically detects when Thumb
7749 instructions are in use, and adjusts disassembly and backtracing
7754 GDB's MIPS target configurations now handle the MIP16 16-bit
7759 GDB now includes support for overlays; if an executable has been
7760 linked such that multiple sections are based at the same address, GDB
7761 will decide which section to use for symbolic info. You can choose to
7762 control the decision manually, using overlay commands, or implement
7763 additional target-side support and use "overlay load-target" to bring
7764 in the overlay mapping. Do "help overlay" for more detail.
7768 The command "info symbol <address>" displays information about
7769 the symbol at the specified address.
7773 The standard remote protocol now includes an extension that allows
7774 asynchronous collection and display of trace data. This requires
7775 extensive support in the target-side debugging stub. Tracing mode
7776 includes a new interaction mode in GDB and new commands: see the
7777 file tracepoint.c for more details.
7781 Configurations for embedded MIPS now include a simulator contributed
7782 by Cygnus Solutions. The simulator supports the instruction sets
7783 of most MIPS variants.
7787 Sparc configurations may now include the ERC32 simulator contributed
7788 by the European Space Agency. The simulator is not built into
7789 Sparc targets by default; configure with --enable-sim to include it.
7793 For target configurations that may include multiple variants of a
7794 basic architecture (such as MIPS and SH), you may now set the
7795 architecture explicitly. "set arch" sets, "info arch" lists
7796 the possible architectures.
7798 *** Changes in GDB-4.16:
7800 * New native configurations
7802 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7803 M68K NetBSD m68k-*-netbsd*
7804 PowerPC AIX 4.x powerpc-*-aix*
7805 PowerPC MacOS powerpc-*-macos*
7806 PowerPC Windows NT powerpcle-*-cygwin32
7807 RS/6000 AIX 4.x rs6000-*-aix4*
7811 ARM with RDP protocol arm-*-*
7812 I960 with MON960 i960-*-coff
7813 MIPS VxWorks mips*-*-vxworks*
7814 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7815 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7817 Matra Sparclet sparclet-*-*
7821 The powerpc-eabi configuration now includes the PSIM simulator,
7822 contributed by Andrew Cagney, with assistance from Mike Meissner.
7823 PSIM is a very elaborate model of the PowerPC, including not only
7824 basic instruction set execution, but also details of execution unit
7825 performance and I/O hardware. See sim/ppc/README for more details.
7829 GDB now works with Solaris 2.5.
7831 * Windows 95/NT native
7833 GDB will now work as a native debugger on Windows 95 and Windows NT.
7834 To build it from source, you must use the "gnu-win32" environment,
7835 which uses a DLL to emulate enough of Unix to run the GNU tools.
7836 Further information, binaries, and sources are available at
7837 ftp.cygnus.com, under pub/gnu-win32.
7839 * dont-repeat command
7841 If a user-defined command includes the command `dont-repeat', then the
7842 command will not be repeated if the user just types return. This is
7843 useful if the command is time-consuming to run, so that accidental
7844 extra keystrokes don't run the same command many times.
7846 * Send break instead of ^C
7848 The standard remote protocol now includes an option to send a break
7849 rather than a ^C to the target in order to interrupt it. By default,
7850 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7852 * Remote protocol timeout
7854 The standard remote protocol includes a new variable `remotetimeout'
7855 that allows you to set the number of seconds before GDB gives up trying
7856 to read from the target. The default value is 2.
7858 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7860 By default GDB will automatically keep track of objects as they are
7861 loaded and unloaded by the dynamic linker. By using the command `set
7862 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7863 when shared library events occur, thus allowing you to set breakpoints
7864 in shared libraries which are explicitly loaded by the inferior.
7866 Note this feature does not work on hpux8. On hpux9 you must link
7867 /usr/lib/end.o into your program. This feature should work
7868 automatically on hpux10.
7870 * Irix 5.x hardware watchpoint support
7872 Irix 5 configurations now support the use of hardware watchpoints.
7874 * Mips protocol "SYN garbage limit"
7876 When debugging a Mips target using the `target mips' protocol, you
7877 may set the number of characters that GDB will ignore by setting
7878 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7879 every character. The default value is 1050.
7881 * Recording and replaying remote debug sessions
7883 If you set `remotelogfile' to the name of a file, gdb will write to it
7884 a recording of a remote debug session. This recording may then be
7885 replayed back to gdb using "gdbreplay". See gdbserver/README for
7886 details. This is useful when you have a problem with GDB while doing
7887 remote debugging; you can make a recording of the session and send it
7888 to someone else, who can then recreate the problem.
7890 * Speedups for remote debugging
7892 GDB includes speedups for downloading and stepping MIPS systems using
7893 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7894 and more efficient S-record downloading.
7896 * Memory use reductions and statistics collection
7898 GDB now uses less memory and reports statistics about memory usage.
7899 Try the `maint print statistics' command, for example.
7901 *** Changes in GDB-4.15:
7903 * Psymtabs for XCOFF
7905 The symbol reader for AIX GDB now uses partial symbol tables. This
7906 can greatly improve startup time, especially for large executables.
7908 * Remote targets use caching
7910 Remote targets now use a data cache to speed up communication with the
7911 remote side. The data cache could lead to incorrect results because
7912 it doesn't know about volatile variables, thus making it impossible to
7913 debug targets which use memory mapped I/O devices. `set remotecache
7914 off' turns the data cache off.
7916 * Remote targets may have threads
7918 The standard remote protocol now includes support for multiple threads
7919 in the target system, using new protocol commands 'H' and 'T'. See
7920 gdb/remote.c for details.
7924 If GDB is configured with `--enable-netrom', then it will include
7925 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7926 acts as though it is a bank of ROM on the target board, but you can
7927 write into it over the network. GDB's support consists only of
7928 support for fast loading into the emulated ROM; to debug, you must use
7929 another protocol, such as standard remote protocol. The usual
7930 sequence is something like
7932 target nrom <netrom-hostname>
7934 target remote <netrom-hostname>:1235
7938 GDB now includes support for the Apple Macintosh, as a host only. It
7939 may be run as either an MPW tool or as a standalone application, and
7940 it can debug through the serial port. All the usual GDB commands are
7941 available, but to the target command, you must supply "serial" as the
7942 device type instead of "/dev/ttyXX". See mpw-README in the main
7943 directory for more information on how to build. The MPW configuration
7944 scripts */mpw-config.in support only a few targets, and only the
7945 mips-idt-ecoff target has been tested.
7949 GDB configuration now uses autoconf. This is not user-visible,
7950 but does simplify configuration and building.
7954 GDB now supports hpux10.
7956 *** Changes in GDB-4.14:
7958 * New native configurations
7960 x86 FreeBSD i[345]86-*-freebsd
7961 x86 NetBSD i[345]86-*-netbsd
7962 NS32k NetBSD ns32k-*-netbsd
7963 Sparc NetBSD sparc-*-netbsd
7967 A29K VxWorks a29k-*-vxworks
7968 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7969 CPU32 EST-300 emulator m68*-*-est*
7970 PowerPC ELF powerpc-*-elf
7973 * Alpha OSF/1 support for procfs
7975 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7976 possible to attach to running processes. As the mounting of the /proc
7977 filesystem is optional on the Alpha, GDB automatically determines
7978 the availability of /proc during startup. This can lead to problems
7979 if /proc is unmounted after GDB has been started.
7981 * Arguments to user-defined commands
7983 User commands may accept up to 10 arguments separated by whitespace.
7984 Arguments are accessed within the user command via $arg0..$arg9. A
7987 print $arg0 + $arg1 + $arg2
7989 To execute the command use:
7992 Defines the command "adder" which prints the sum of its three arguments.
7993 Note the arguments are text substitutions, so they may reference variables,
7994 use complex expressions, or even perform inferior function calls.
7996 * New `if' and `while' commands
7998 This makes it possible to write more sophisticated user-defined
7999 commands. Both commands take a single argument, which is the
8000 expression to evaluate, and must be followed by the commands to
8001 execute, one per line, if the expression is nonzero, the list being
8002 terminated by the word `end'. The `if' command list may include an
8003 `else' word, which causes the following commands to be executed only
8004 if the expression is zero.
8006 * Fortran source language mode
8008 GDB now includes partial support for Fortran 77. It will recognize
8009 Fortran programs and can evaluate a subset of Fortran expressions, but
8010 variables and functions may not be handled correctly. GDB will work
8011 with G77, but does not yet know much about symbols emitted by other
8014 * Better HPUX support
8016 Most debugging facilities now work on dynamic executables for HPPAs
8017 running hpux9 or later. You can attach to running dynamically linked
8018 processes, but by default the dynamic libraries will be read-only, so
8019 for instance you won't be able to put breakpoints in them. To change
8020 that behavior do the following before running the program:
8026 This will cause the libraries to be mapped private and read-write.
8027 To revert to the normal behavior, do this:
8033 You cannot set breakpoints or examine data in the library until after
8034 the library is loaded if the function/data symbols do not have
8037 GDB can now also read debug symbols produced by the HP C compiler on
8038 HPPAs (sorry, no C++, Fortran or 68k support).
8040 * Target byte order now dynamically selectable
8042 You can choose which byte order to use with a target system, via the
8043 commands "set endian big" and "set endian little", and you can see the
8044 current setting by using "show endian". You can also give the command
8045 "set endian auto", in which case GDB will use the byte order
8046 associated with the executable. Currently, only embedded MIPS
8047 configurations support dynamic selection of target byte order.
8049 * New DOS host serial code
8051 This version uses DPMI interrupts to handle buffered I/O, so you
8052 no longer need to run asynctsr when debugging boards connected to
8055 *** Changes in GDB-4.13:
8057 * New "complete" command
8059 This lists all the possible completions for the rest of the line, if it
8060 were to be given as a command itself. This is intended for use by emacs.
8062 * Trailing space optional in prompt
8064 "set prompt" no longer adds a space for you after the prompt you set. This
8065 allows you to set a prompt which ends in a space or one that does not.
8067 * Breakpoint hit counts
8069 "info break" now displays a count of the number of times the breakpoint
8070 has been hit. This is especially useful in conjunction with "ignore"; you
8071 can ignore a large number of breakpoint hits, look at the breakpoint info
8072 to see how many times the breakpoint was hit, then run again, ignoring one
8073 less than that number, and this will get you quickly to the last hit of
8076 * Ability to stop printing at NULL character
8078 "set print null-stop" will cause GDB to stop printing the characters of
8079 an array when the first NULL is encountered. This is useful when large
8080 arrays actually contain only short strings.
8082 * Shared library breakpoints
8084 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8085 breakpoints in shared libraries before the executable is run.
8087 * Hardware watchpoints
8089 There is a new hardware breakpoint for the watch command for sparclite
8090 targets. See gdb/sparclite/hw_breakpoint.note.
8092 Hardware watchpoints are also now supported under GNU/Linux.
8096 Annotations have been added. These are for use with graphical interfaces,
8097 and are still experimental. Currently only gdba.el uses these.
8099 * Improved Irix 5 support
8101 GDB now works properly with Irix 5.2.
8103 * Improved HPPA support
8105 GDB now works properly with the latest GCC and GAS.
8107 * New native configurations
8109 Sequent PTX4 i[34]86-sequent-ptx4
8110 HPPA running OSF/1 hppa*-*-osf*
8111 Atari TT running SVR4 m68*-*-sysv4*
8112 RS/6000 LynxOS rs6000-*-lynxos*
8116 OS/9000 i[34]86-*-os9k
8117 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8120 * Hitachi SH7000 and E7000-PC ICE support
8122 There is now support for communicating with the Hitachi E7000-PC ICE.
8123 This is available automatically when GDB is configured for the SH.
8127 As usual, a variety of small fixes and improvements, both generic
8128 and configuration-specific. See the ChangeLog for more detail.
8130 *** Changes in GDB-4.12:
8132 * Irix 5 is now supported
8136 GDB-4.12 on the HPPA has a number of changes which make it unable
8137 to debug the output from the currently released versions of GCC and
8138 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8139 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8140 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8143 *** Changes in GDB-4.11:
8145 * User visible changes:
8149 The "set remotedebug" option is now consistent between the mips remote
8150 target, remote targets using the gdb-specific protocol, UDI (AMD's
8151 debug protocol for the 29k) and the 88k bug monitor. It is now an
8152 integer specifying a debug level (normally 0 or 1, but 2 means more
8153 debugging info for the mips target).
8155 * DEC Alpha native support
8157 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8158 debug info, but GDB works fairly well with the DEC compiler and should
8159 work with a future GCC release. See the README file for a few
8160 Alpha-specific notes.
8162 * Preliminary thread implementation
8164 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8166 * LynxOS native and target support for 386
8168 This release has been hosted on LynxOS 2.2, and also can be configured
8169 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8172 * Improvements in C++ mangling/demangling.
8174 This release has much better g++ debugging, specifically in name
8175 mangling/demangling, virtual function calls, print virtual table,
8176 call methods, ...etc.
8178 *** Changes in GDB-4.10:
8180 * User visible changes:
8182 Remote debugging using the GDB-specific (`target remote') protocol now
8183 supports the `load' command. This is only useful if you have some
8184 other way of getting the stub to the target system, and you can put it
8185 somewhere in memory where it won't get clobbered by the download.
8187 Filename completion now works.
8189 When run under emacs mode, the "info line" command now causes the
8190 arrow to point to the line specified. Also, "info line" prints
8191 addresses in symbolic form (as well as hex).
8193 All vxworks based targets now support a user settable option, called
8194 vxworks-timeout. This option represents the number of seconds gdb
8195 should wait for responses to rpc's. You might want to use this if
8196 your vxworks target is, perhaps, a slow software simulator or happens
8197 to be on the far side of a thin network line.
8201 This release contains support for using a DEC alpha as a GDB host for
8202 cross debugging. Native alpha debugging is not supported yet.
8205 *** Changes in GDB-4.9:
8209 This is the first GDB release which is accompanied by a matching testsuite.
8210 The testsuite requires installation of dejagnu, which should be available
8211 via ftp from most sites that carry GNU software.
8215 'Cfront' style demangling has had its name changed to 'ARM' style, to
8216 emphasize that it was written from the specifications in the C++ Annotated
8217 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8218 disclaimers, it still generated too much confusion with users attempting to
8219 use gdb with AT&T cfront.
8223 GDB now uses a standard remote interface to a simulator library.
8224 So far, the library contains simulators for the Zilog Z8001/2, the
8225 Hitachi H8/300, H8/500 and Super-H.
8227 * New targets supported
8229 H8/300 simulator h8300-hitachi-hms or h8300hms
8230 H8/500 simulator h8500-hitachi-hms or h8500hms
8231 SH simulator sh-hitachi-hms or sh
8232 Z8000 simulator z8k-zilog-none or z8ksim
8233 IDT MIPS board over serial line mips-idt-ecoff
8235 Cross-debugging to GO32 targets is supported. It requires a custom
8236 version of the i386-stub.c module which is integrated with the
8237 GO32 memory extender.
8239 * New remote protocols
8241 MIPS remote debugging protocol.
8243 * New source languages supported
8245 This version includes preliminary support for Chill, a Pascal like language
8246 used by telecommunications companies. Chill support is also being integrated
8247 into the GNU compiler, but we don't know when it will be publically available.
8250 *** Changes in GDB-4.8:
8252 * HP Precision Architecture supported
8254 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8255 version of this support was available as a set of patches from the
8256 University of Utah. GDB does not support debugging of programs
8257 compiled with the HP compiler, because HP will not document their file
8258 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8259 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8261 Many problems in the preliminary version have been fixed.
8263 * Faster and better demangling
8265 We have improved template demangling and fixed numerous bugs in the GNU style
8266 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8267 character types (wchar_t) are now supported. Demangling of each symbol is now
8268 only done once, and is cached when the symbol table for a file is read in.
8269 This results in a small increase in memory usage for C programs, a moderate
8270 increase in memory usage for C++ programs, and a fantastic speedup in
8273 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8274 from the specifications in the Annotated Reference Manual, which AT&T's
8275 compiler does not actually implement.
8277 * G++ multiple inheritance compiler problem
8279 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8280 inheritance lattices was reworked to properly discover ambiguities. We
8281 recently found an example which causes this new algorithm to fail in a
8282 very subtle way, producing bad debug information for those classes.
8283 The file 'gcc.patch' (in this directory) can be applied to gcc to
8284 circumvent the problem. A future GCC release will contain a complete
8287 The previous G++ debug info problem (mentioned below for the gdb-4.7
8288 release) is fixed in gcc version 2.3.2.
8290 * Improved configure script
8292 The `configure' script will now attempt to guess your system type if
8293 you don't supply a host system type. The old scheme of supplying a
8294 host system triplet is preferable over using this. All the magic is
8295 done in the new `config.guess' script. Examine it for details.
8297 We have also brought our configure script much more in line with the FSF's
8298 version. It now supports the --with-xxx options. In particular,
8299 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8300 The resulting GDB will not be able to read arbitrary object file formats --
8301 only the format ``expected'' to be used on the configured target system.
8302 We hope to make this the default in a future release.
8304 * Documentation improvements
8306 There's new internal documentation on how to modify GDB, and how to
8307 produce clean changes to the code. We implore people to read it
8308 before submitting changes.
8310 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8311 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8312 `info' files are also provided. To build `info' files from scratch,
8313 you will need the latest `makeinfo' release, which will be available in
8314 a future texinfo-X.Y release.
8316 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8317 We're not sure exactly which versions have this problem, but it has
8318 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8319 or better. If that isn't possible, there is a patch in
8320 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8321 around this problem.
8325 GDB now supports array constants that can be used in expressions typed in by
8326 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8327 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8330 The new directory `gdb/sparclite' contains a program that demonstrates
8331 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8333 * New native hosts supported
8335 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8336 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8338 * New targets supported
8340 AMD 29k family via UDI a29k-amd-udi or udi29k
8342 * New file formats supported
8344 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8345 HPUX core files, and SCO 3.2v2 core files.
8349 Attaching to processes now works again; thanks for the many bug reports.
8351 We have also stomped on a bunch of core dumps caused by
8352 printf_filtered("%s") problems.
8354 We eliminated a copyright problem on the rpc and ptrace header files
8355 for VxWorks, which was discovered at the last minute during the 4.7
8356 release. You should now be able to build a VxWorks GDB.
8358 You can now interrupt gdb while an attached process is running. This
8359 will cause the attached process to stop, and give control back to GDB.
8361 We fixed problems caused by using too many file descriptors
8362 for reading symbols from object files and libraries. This was
8363 especially a problem for programs that used many (~100) shared
8366 The `step' command now only enters a subroutine if there is line number
8367 information for the subroutine. Otherwise it acts like the `next'
8368 command. Previously, `step' would enter subroutines if there was
8369 any debugging information about the routine. This avoids problems
8370 when using `cc -g1' on MIPS machines.
8372 * Internal improvements
8374 GDB's internal interfaces have been improved to make it easier to support
8375 debugging of multiple languages in the future.
8377 GDB now uses a common structure for symbol information internally.
8378 Minimal symbols (derived from linkage symbols in object files), partial
8379 symbols (from a quick scan of debug information), and full symbols
8380 contain a common subset of information, making it easier to write
8381 shared code that handles any of them.
8383 * New command line options
8385 We now accept --silent as an alias for --quiet.
8389 The memory-mapped-malloc library is now licensed under the GNU Library
8390 General Public License.
8392 *** Changes in GDB-4.7:
8394 * Host/native/target split
8396 GDB has had some major internal surgery to untangle the support for
8397 hosts and remote targets. Now, when you configure GDB for a remote
8398 target, it will no longer load in all of the support for debugging
8399 local programs on the host. When fully completed and tested, this will
8400 ensure that arbitrary host/target combinations are possible.
8402 The primary conceptual shift is to separate the non-portable code in
8403 GDB into three categories. Host specific code is required any time GDB
8404 is compiled on that host, regardless of the target. Target specific
8405 code relates to the peculiarities of the target, but can be compiled on
8406 any host. Native specific code is everything else: it can only be
8407 built when the host and target are the same system. Child process
8408 handling and core file support are two common `native' examples.
8410 GDB's use of /proc for controlling Unix child processes is now cleaner.
8411 It has been split out into a single module under the `target_ops' vector,
8412 plus two native-dependent functions for each system that uses /proc.
8414 * New hosts supported
8416 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8417 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8418 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8420 * New targets supported
8422 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8423 68030 and CPU32 m68030-*-*, m68332-*-*
8425 * New native hosts supported
8427 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8428 (386bsd is not well tested yet)
8429 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8431 * New file formats supported
8433 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8434 supports reading of `a.out.adobe' object files, which are an a.out
8435 format extended with minimal information about multiple sections.
8439 `show copying' is the same as the old `info copying'.
8440 `show warranty' is the same as `info warrantee'.
8441 These were renamed for consistency. The old commands continue to work.
8443 `info handle' is a new alias for `info signals'.
8445 You can now define pre-command hooks, which attach arbitrary command
8446 scripts to any command. The commands in the hook will be executed
8447 prior to the user's command. You can also create a hook which will be
8448 executed whenever the program stops. See gdb.texinfo.
8452 We now deal with Cfront style name mangling, and can even extract type
8453 info from mangled symbols. GDB can automatically figure out which
8454 symbol mangling style your C++ compiler uses.
8456 Calling of methods and virtual functions has been improved as well.
8460 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8461 fixed. This was due to mishandling of the extra N_SO stabs output
8464 We also finally got Ultrix 4.2 running in house, and fixed core file
8465 support, with help from a dozen people on the net.
8467 John M. Farrell discovered that the reason that single-stepping was so
8468 slow on all of the Mips based platforms (primarily SGI and DEC) was
8469 that we were trying to demangle and lookup a symbol used for internal
8470 purposes on every instruction that was being stepped through. Changing
8471 the name of that symbol so that it couldn't be mistaken for a C++
8472 mangled symbol sped things up a great deal.
8474 Rich Pixley sped up symbol lookups in general by getting much smarter
8475 about when C++ symbol mangling is necessary. This should make symbol
8476 completion (TAB on the command line) much faster. It's not as fast as
8477 we'd like, but it's significantly faster than gdb-4.6.
8481 A new user controllable variable 'call_scratch_address' can
8482 specify the location of a scratch area to be used when GDB
8483 calls a function in the target. This is necessary because the
8484 usual method of putting the scratch area on the stack does not work
8485 in systems that have separate instruction and data spaces.
8487 We integrated changes to support the 29k UDI (Universal Debugger
8488 Interface), but discovered at the last minute that we didn't have all
8489 of the appropriate copyright paperwork. We are working with AMD to
8490 resolve this, and hope to have it available soon.
8494 We have sped up the remote serial line protocol, especially for targets
8495 with lots of registers. It now supports a new `expedited status' ('T')
8496 message which can be used in place of the existing 'S' status message.
8497 This allows the remote stub to send only the registers that GDB
8498 needs to make a quick decision about single-stepping or conditional
8499 breakpoints, eliminating the need to fetch the entire register set for
8500 each instruction being stepped through.
8502 The GDB remote serial protocol now implements a write-through cache for
8503 registers, only re-reading the registers if the target has run.
8505 There is also a new remote serial stub for SPARC processors. You can
8506 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8507 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8508 processor with a serial port.
8512 Configure.in files have become much easier to read and modify. A new
8513 `table driven' format makes it more obvious what configurations are
8514 supported, and what files each one uses.
8518 There is a new opcodes library which will eventually contain all of the
8519 disassembly routines and opcode tables. At present, it only contains
8520 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8521 disassembler (binutils/objdump) to share these routines.
8523 The libiberty library is now copylefted under the GNU Library General
8524 Public License. This allows more liberal use, and was done so libg++
8525 can use it. This makes no difference to GDB, since the Library License
8526 grants all the rights from the General Public License.
8530 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8531 reference to the stabs symbol info used by the debugger. It is (as far
8532 as we know) the only published document on this fascinating topic. We
8533 encourage you to read it, compare it to the stabs information on your
8534 system, and send improvements on the document in general (to
8535 bug-gdb@prep.ai.mit.edu).
8537 And, of course, many bugs have been fixed.
8540 *** Changes in GDB-4.6:
8542 * Better support for C++ function names
8544 GDB now accepts as input the "demangled form" of C++ overloaded function
8545 names and member function names, and can do command completion on such names
8546 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8547 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8548 Make use of command completion, it is your friend.
8550 GDB also now accepts a variety of C++ mangled symbol formats. They are
8551 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8552 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8553 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8554 for the list of formats.
8556 * G++ symbol mangling problem
8558 Recent versions of gcc have a bug in how they emit debugging information for
8559 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8560 directory) can be applied to gcc to fix the problem. Alternatively, if you
8561 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8562 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8563 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8566 * New 'maintenance' command
8568 All of the commands related to hacking GDB internals have been moved out of
8569 the main command set, and now live behind the 'maintenance' command. This
8570 can also be abbreviated as 'mt'. The following changes were made:
8572 dump-me -> maintenance dump-me
8573 info all-breakpoints -> maintenance info breakpoints
8574 printmsyms -> maintenance print msyms
8575 printobjfiles -> maintenance print objfiles
8576 printpsyms -> maintenance print psymbols
8577 printsyms -> maintenance print symbols
8579 The following commands are new:
8581 maintenance demangle Call internal GDB demangler routine to
8582 demangle a C++ link name and prints the result.
8583 maintenance print type Print a type chain for a given symbol
8585 * Change to .gdbinit file processing
8587 We now read the $HOME/.gdbinit file before processing the argv arguments
8588 (e.g. reading symbol files or core files). This allows global parameters to
8589 be set, which will apply during the symbol reading. The ./.gdbinit is still
8590 read after argv processing.
8592 * New hosts supported
8594 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8596 GNU/Linux support i386-unknown-linux or linux
8598 We are also including code to support the HP/PA running BSD and HPUX. This
8599 is almost guaranteed not to work, as we didn't have time to test or build it
8600 for this release. We are including it so that the more adventurous (or
8601 masochistic) of you can play with it. We also had major problems with the
8602 fact that the compiler that we got from HP doesn't support the -g option.
8605 * New targets supported
8607 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8609 * More smarts about finding #include files
8611 GDB now remembers the compilation directory for all include files, and for
8612 all files from which C is generated (like yacc and lex sources). This
8613 greatly improves GDB's ability to find yacc/lex sources, and include files,
8614 especially if you are debugging your program from a directory different from
8615 the one that contains your sources.
8617 We also fixed a bug which caused difficulty with listing and setting
8618 breakpoints in include files which contain C code. (In the past, you had to
8619 try twice in order to list an include file that you hadn't looked at before.)
8621 * Interesting infernals change
8623 GDB now deals with arbitrary numbers of sections, where the symbols for each
8624 section must be relocated relative to that section's landing place in the
8625 target's address space. This work was needed to support ELF with embedded
8626 stabs used by Solaris-2.0.
8628 * Bug fixes (of course!)
8630 There have been loads of fixes for the following things:
8631 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8632 i960, stabs, DOS(GO32), procfs, etc...
8634 See the ChangeLog for details.
8636 *** Changes in GDB-4.5:
8638 * New machines supported (host and target)
8640 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8642 SGI Irix-4.x mips-sgi-irix4 or iris4
8644 * New malloc package
8646 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8647 Mmalloc is capable of handling multiple heaps of memory. It is also
8648 capable of saving a heap to a file, and then mapping it back in later.
8649 This can be used to greatly speedup the startup of GDB by using a
8650 pre-parsed symbol table which lives in a mmalloc managed heap. For
8651 more details, please read mmalloc/mmalloc.texi.
8655 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8656 'help info proc' for details.
8658 * MIPS ecoff symbol table format
8660 The code that reads MIPS symbol table format is now supported on all hosts.
8661 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8664 * File name changes for MS-DOS
8666 Many files in the config directories have been renamed to make it easier to
8667 support GDB on MS-DOSe systems (which have very restrictive file name
8668 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8669 environment) is close to working but has some remaining problems. Note
8670 that debugging of DOS programs is not supported, due to limitations
8671 in the ``operating system'', but it can be used to host cross-debugging.
8673 * Cross byte order fixes
8675 Many fixes have been made to support cross debugging of Sparc and MIPS
8676 targets from hosts whose byte order differs.
8678 * New -mapped and -readnow options
8680 If memory-mapped files are available on your system through the 'mmap'
8681 system call, you can use the -mapped option on the `file' or
8682 `symbol-file' commands to cause GDB to write the symbols from your
8683 program into a reusable file. If the program you are debugging is
8684 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8685 Future GDB debugging sessions will notice the presence of this file,
8686 and will quickly map in symbol information from it, rather than reading
8687 the symbol table from the executable program. Using the '-mapped'
8688 option in a GDB `file' or `symbol-file' command has the same effect as
8689 starting GDB with the '-mapped' command-line option.
8691 You can cause GDB to read the entire symbol table immediately by using
8692 the '-readnow' option with any of the commands that load symbol table
8693 information (or on the GDB command line). This makes the command
8694 slower, but makes future operations faster.
8696 The -mapped and -readnow options are typically combined in order to
8697 build a `fred.syms' file that contains complete symbol information.
8698 A simple GDB invocation to do nothing but build a `.syms' file for future
8701 gdb -batch -nx -mapped -readnow programname
8703 The `.syms' file is specific to the host machine on which GDB is run.
8704 It holds an exact image of GDB's internal symbol table. It cannot be
8705 shared across multiple host platforms.
8707 * longjmp() handling
8709 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8710 siglongjmp() without losing control. This feature has not yet been ported to
8711 all systems. It currently works on many 386 platforms, all MIPS-based
8712 platforms (SGI, DECstation, etc), and Sun3/4.
8716 Preliminary work has been put in to support the new Solaris OS from Sun. At
8717 this time, it can control and debug processes, but it is not capable of
8722 As always, many many bug fixes. The major areas were with g++, and mipsread.
8723 People using the MIPS-based platforms should experience fewer mysterious
8724 crashes and trashed symbol tables.
8726 *** Changes in GDB-4.4:
8728 * New machines supported (host and target)
8730 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8732 BSD Reno on Vax vax-dec-bsd
8733 Ultrix on Vax vax-dec-ultrix
8735 * New machines supported (target)
8737 AMD 29000 embedded, using EBMON a29k-none-none
8741 GDB continues to improve its handling of C++. `References' work better.
8742 The demangler has also been improved, and now deals with symbols mangled as
8743 per the Annotated C++ Reference Guide.
8745 GDB also now handles `stabs' symbol information embedded in MIPS
8746 `ecoff' symbol tables. Since the ecoff format was not easily
8747 extensible to handle new languages such as C++, this appeared to be a
8748 good way to put C++ debugging info into MIPS binaries. This option
8749 will be supported in the GNU C compiler, version 2, when it is
8752 * New features for SVR4
8754 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8755 shared libraries. Debugging dynamically linked programs should present
8756 only minor differences from debugging statically linked programs.
8758 The `info proc' command will print out information about any process
8759 on an SVR4 system (including the one you are debugging). At the moment,
8760 it prints the address mappings of the process.
8762 If you bring up GDB on another SVR4 system, please send mail to
8763 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8765 * Better dynamic linking support in SunOS
8767 Reading symbols from shared libraries which contain debugging symbols
8768 now works properly. However, there remain issues such as automatic
8769 skipping of `transfer vector' code during function calls, which
8770 make it harder to debug code in a shared library, than to debug the
8771 same code linked statically.
8775 GDB is now using the latest `getopt' routines from the FSF. This
8776 version accepts the -- prefix for options with long names. GDB will
8777 continue to accept the old forms (-option and +option) as well.
8778 Various single letter abbreviations for options have been explicity
8779 added to the option table so that they won't get overshadowed in the
8780 future by other options that begin with the same letter.
8784 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8785 Many assorted bugs have been handled. Many more remain to be handled.
8786 See the various ChangeLog files (primarily in gdb and bfd) for details.
8789 *** Changes in GDB-4.3:
8791 * New machines supported (host and target)
8793 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8794 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8795 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8797 * Almost SCO Unix support
8799 We had hoped to support:
8800 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8801 (except for core file support), but we discovered very late in the release
8802 that it has problems with process groups that render gdb unusable. Sorry
8803 about that. I encourage people to fix it and post the fixes.
8805 * Preliminary ELF and DWARF support
8807 GDB can read ELF object files on System V Release 4, and can handle
8808 debugging records for C, in DWARF format, in ELF files. This support
8809 is preliminary. If you bring up GDB on another SVR4 system, please
8810 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8815 GDB now uses the latest `readline' library. One user-visible change
8816 is that two tabs will list possible command completions, which previously
8817 required typing M-? (meta-question mark, or ESC ?).
8821 The `stepi' bug that many of you noticed has been squashed.
8822 Many bugs in C++ have been handled. Many more remain to be handled.
8823 See the various ChangeLog files (primarily in gdb and bfd) for details.
8825 * State of the MIPS world (in case you wondered):
8827 GDB can understand the symbol tables emitted by the compilers
8828 supplied by most vendors of MIPS-based machines, including DEC. These
8829 symbol tables are in a format that essentially nobody else uses.
8831 Some versions of gcc come with an assembler post-processor called
8832 mips-tfile. This program is required if you want to do source-level
8833 debugging of gcc-compiled programs. I believe FSF does not ship
8834 mips-tfile with gcc version 1, but it will eventually come with gcc
8837 Debugging of g++ output remains a problem. g++ version 1.xx does not
8838 really support it at all. (If you're lucky, you should be able to get
8839 line numbers and stack traces to work, but no parameters or local
8840 variables.) With some work it should be possible to improve the
8843 When gcc version 2 is released, you will have somewhat better luck.
8844 However, even then you will get confusing results for inheritance and
8847 We will eventually provide full debugging of g++ output on
8848 DECstations. This will probably involve some kind of stabs-in-ecoff
8849 encapulation, but the details have not been worked out yet.
8852 *** Changes in GDB-4.2:
8854 * Improved configuration
8856 Only one copy of `configure' exists now, and it is not self-modifying.
8857 Porting BFD is simpler.
8861 The `step' and `next' commands now only stop at the first instruction
8862 of a source line. This prevents the multiple stops that used to occur
8863 in switch statements, for-loops, etc. `Step' continues to stop if a
8864 function that has debugging information is called within the line.
8868 Lots of small bugs fixed. More remain.
8870 * New host supported (not target)
8872 Intel 386 PC clone running Mach i386-none-mach
8875 *** Changes in GDB-4.1:
8877 * Multiple source language support
8879 GDB now has internal scaffolding to handle several source languages.
8880 It determines the type of each source file from its filename extension,
8881 and will switch expression parsing and number formatting to match the
8882 language of the function in the currently selected stack frame.
8883 You can also specifically set the language to be used, with
8884 `set language c' or `set language modula-2'.
8888 GDB now has preliminary support for the GNU Modula-2 compiler,
8889 currently under development at the State University of New York at
8890 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8891 continue through the fall of 1991 and into 1992.
8893 Other Modula-2 compilers are currently not supported, and attempting to
8894 debug programs compiled with them will likely result in an error as the
8895 symbol table is read. Feel free to work on it, though!
8897 There are hooks in GDB for strict type checking and range checking,
8898 in the `Modula-2 philosophy', but they do not currently work.
8902 GDB can now write to executable and core files (e.g. patch
8903 a variable's value). You must turn this switch on, specify
8904 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8905 by assigning a new value to a variable. Modifications take
8908 * Automatic SunOS shared library reading
8910 When you run your program, GDB automatically determines where its
8911 shared libraries (if any) have been loaded, and reads their symbols.
8912 The `share' command is no longer needed. This also works when
8913 examining core files.
8917 You can specify the number of lines that the `list' command shows.
8920 * New machines supported (host and target)
8922 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8923 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8924 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8926 * New hosts supported (not targets)
8928 IBM RT/PC: romp-ibm-aix or rtpc
8930 * New targets supported (not hosts)
8932 AMD 29000 embedded with COFF a29k-none-coff
8933 AMD 29000 embedded with a.out a29k-none-aout
8934 Ultracomputer remote kernel debug a29k-nyu-kern
8936 * New remote interfaces
8942 *** Changes in GDB-4.0:
8946 Wide output is wrapped at good places to make the output more readable.
8948 Gdb now supports cross-debugging from a host machine of one type to a
8949 target machine of another type. Communication with the target system
8950 is over serial lines. The ``target'' command handles connecting to the
8951 remote system; the ``load'' command will download a program into the
8952 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8953 also supports debugging of realtime processes running under VxWorks,
8954 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8955 stub on the target system.
8957 New CPUs supported include the AMD 29000 and Intel 960.
8959 GDB now reads object files and symbol tables via a ``binary file''
8960 library, which allows a single copy of GDB to debug programs of multiple
8961 object file types such as a.out and coff.
8963 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8964 refcard.dvi and refcard.ps are available to format it).
8967 * Control-Variable user interface simplified
8969 All variables that control the operation of the debugger can be set
8970 by the ``set'' command, and displayed by the ``show'' command.
8972 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8973 ``Show prompt'' produces the response:
8974 Gdb's prompt is new-gdb=>.
8976 What follows are the NEW set commands. The command ``help set'' will
8977 print a complete list of old and new set commands. ``help set FOO''
8978 will give a longer description of the variable FOO. ``show'' will show
8979 all of the variable descriptions and their current settings.
8981 confirm on/off: Enables warning questions for operations that are
8982 hard to recover from, e.g. rerunning the program while
8983 it is already running. Default is ON.
8985 editing on/off: Enables EMACS style command line editing
8986 of input. Previous lines can be recalled with
8987 control-P, the current line can be edited with control-B,
8988 you can search for commands with control-R, etc.
8991 history filename NAME: NAME is where the gdb command history
8992 will be stored. The default is .gdb_history,
8993 or the value of the environment variable
8996 history size N: The size, in commands, of the command history. The
8997 default is 256, or the value of the environment variable
9000 history save on/off: If this value is set to ON, the history file will
9001 be saved after exiting gdb. If set to OFF, the
9002 file will not be saved. The default is OFF.
9004 history expansion on/off: If this value is set to ON, then csh-like
9005 history expansion will be performed on
9006 command line input. The default is OFF.
9008 radix N: Sets the default radix for input and output. It can be set
9009 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9010 in the current radix, so "set radix 10" is always a no-op.
9012 height N: This integer value is the number of lines on a page. Default
9013 is 24, the current `stty rows'' setting, or the ``li#''
9014 setting from the termcap entry matching the environment
9017 width N: This integer value is the number of characters on a line.
9018 Default is 80, the current `stty cols'' setting, or the ``co#''
9019 setting from the termcap entry matching the environment
9022 Note: ``set screensize'' is obsolete. Use ``set height'' and
9023 ``set width'' instead.
9025 print address on/off: Print memory addresses in various command displays,
9026 such as stack traces and structure values. Gdb looks
9027 more ``symbolic'' if you turn this off; it looks more
9028 ``machine level'' with it on. Default is ON.
9030 print array on/off: Prettyprint arrays. New convenient format! Default
9033 print demangle on/off: Print C++ symbols in "source" form if on,
9036 print asm-demangle on/off: Same, for assembler level printouts
9039 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9042 * Support for Epoch Environment.
9044 The epoch environment is a version of Emacs v18 with windowing. One
9045 new command, ``inspect'', is identical to ``print'', except that if you
9046 are running in the epoch environment, the value is printed in its own
9050 * Support for Shared Libraries
9052 GDB can now debug programs and core files that use SunOS shared libraries.
9053 Symbols from a shared library cannot be referenced
9054 before the shared library has been linked with the program (this
9055 happens after you type ``run'' and before the function main() is entered).
9056 At any time after this linking (including when examining core files
9057 from dynamically linked programs), gdb reads the symbols from each
9058 shared library when you type the ``sharedlibrary'' command.
9059 It can be abbreviated ``share''.
9061 sharedlibrary REGEXP: Load shared object library symbols for files
9062 matching a unix regular expression. No argument
9063 indicates to load symbols for all shared libraries.
9065 info sharedlibrary: Status of loaded shared libraries.
9070 A watchpoint stops execution of a program whenever the value of an
9071 expression changes. Checking for this slows down execution
9072 tremendously whenever you are in the scope of the expression, but is
9073 quite useful for catching tough ``bit-spreader'' or pointer misuse
9074 problems. Some machines such as the 386 have hardware for doing this
9075 more quickly, and future versions of gdb will use this hardware.
9077 watch EXP: Set a watchpoint (breakpoint) for an expression.
9079 info watchpoints: Information about your watchpoints.
9081 delete N: Deletes watchpoint number N (same as breakpoints).
9082 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9083 enable N: Re-enables watchpoint number N (same as breakpoints).
9086 * C++ multiple inheritance
9088 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9091 * C++ exception handling
9093 Gdb now supports limited C++ exception handling. Besides the existing
9094 ability to breakpoint on an exception handler, gdb can breakpoint on
9095 the raising of an exception (before the stack is peeled back to the
9098 catch FOO: If there is a FOO exception handler in the dynamic scope,
9099 set a breakpoint to catch exceptions which may be raised there.
9100 Multiple exceptions (``catch foo bar baz'') may be caught.
9102 info catch: Lists all exceptions which may be caught in the
9103 current stack frame.
9106 * Minor command changes
9108 The command ``call func (arg, arg, ...)'' now acts like the print
9109 command, except it does not print or save a value if the function's result
9110 is void. This is similar to dbx usage.
9112 The ``up'' and ``down'' commands now always print the frame they end up
9113 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9114 frames without printing.
9116 * New directory command
9118 'dir' now adds directories to the FRONT of the source search path.
9119 The path starts off empty. Source files that contain debug information
9120 about the directory in which they were compiled can be found even
9121 with an empty path; Sun CC and GCC include this information. If GDB can't
9122 find your source file in the current directory, type "dir .".
9124 * Configuring GDB for compilation
9126 For normal use, type ``./configure host''. See README or gdb.texinfo
9129 GDB now handles cross debugging. If you are remotely debugging between
9130 two different machines, type ``./configure host -target=targ''.
9131 Host is the machine where GDB will run; targ is the machine
9132 where the program that you are debugging will run.