1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 12
6 * "info breakpoints" now displays enabled breakpoint locations of
7 disabled breakpoints as in the "y-" state. For example:
10 Num Type Disp Enb Address What
11 1 breakpoint keep n <MULTIPLE>
12 1.1 y- 0x00000000000011b6 in ...
13 1.2 y- 0x00000000000011c2 in ...
14 1.3 n 0x00000000000011ce in ...
16 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
17 aarch64 architectures.
19 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
21 * Remove support for building against Python 2, it is now only possible to
22 build GDB against Python 3.
24 * DBX mode has been removed.
26 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
27 emit to indicate where a breakpoint should be placed to break in a function
30 * Completion now also offers "NUMBER" for "set" commands that accept
31 a numeric argument and the "unlimited" keyword. For example:
38 (gdb) complete set width
42 * Disassembler styling using libopcodes. GDB now supports
43 disassembler styling using libopcodes. This is only available for
44 some targets (currently x86 and RISC-V). For unsupported targets
45 Python Pygments is still used. For supported targets, libopcodes
46 styling is used by default.
50 maintenance set ignore-prologue-end-flag on|off
51 maintenance show ignore-prologue-end-flag
52 This setting, which is off by default, controls whether GDB ignores the
53 PROLOGUE-END flag from the line-table when skipping prologue. This can be
54 used to force GDB to use prologue analyzers if the line-table is constructed
55 from erroneous debug information.
57 set print nibbles [on|off]
59 This controls whether the 'print/t' command will display binary values
60 in groups of four bits, known as "nibbles". The default is 'off'.
62 maintenance set libopcodes-styling on|off
63 maintenance show libopcodes-styling
64 These can be used to force off libopcodes based styling, the Python
65 Pygments styling will then be used instead.
67 set style disassembler comment
68 show style disassembler comment
69 set style disassembler immediate
70 show style disassembler immediate
71 set style disassembler mnemonic
72 show style disassembler mnemonic
73 set style disassembler register
74 show style disassembler register
75 set style disassembler address
76 show style disassembler address
77 set style disassembler symbol
78 show style disassembler symbol
79 For targets that support libopcodes based styling, these settings
80 control how various aspects of the disassembler output are styled.
81 The 'disassembler address' and 'disassembler symbol' styles are
82 aliases for the 'address' and 'function' styles respectively.
86 maintenance info line-table
87 Add a PROLOGUE-END column to the output which indicates that an
88 entry corresponds to an address where a breakpoint should be placed
89 to be at the first instruction past a function's prologue.
93 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
97 ** GDB will now reformat the doc string for gdb.Command and
98 gdb.Parameter sub-classes to remove unnecessary leading
99 whitespace from each line before using the string as the help
102 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
103 that formats ADDRESS as 'address <symbol+offset>', where symbol is
104 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
105 This is the same format that GDB uses when printing address, symbol,
106 and offset information from the disassembler.
108 ** New function gdb.current_language that returns the name of the
109 current language. Unlike gdb.parameter('language'), this will
112 ** New method gdb.Frame.language that returns the name of the
115 ** New Python API for wrapping GDB's disassembler:
117 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
118 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
119 ARCH is either None or a string containing a bfd architecture
120 name. DISASSEMBLER is registered as a disassembler for
121 architecture ARCH, or for all architectures if ARCH is None.
122 The previous disassembler registered for ARCH is returned, this
123 can be None if no previous disassembler was registered.
125 - gdb.disassembler.Disassembler is the class from which all
126 disassemblers should inherit. Its constructor takes a string,
127 a name for the disassembler, which is currently only used in
128 some debug output. Sub-classes should override the __call__
129 method to perform disassembly, invoking __call__ on this base
130 class will raise an exception.
132 - gdb.disassembler.DisassembleInfo is the class used to describe
133 a single disassembly request from GDB. An instance of this
134 class is passed to the __call__ method of
135 gdb.disassembler.Disassembler and has the following read-only
136 attributes: 'address', and 'architecture', as well as the
137 following method: 'read_memory'.
139 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
140 calls GDB's builtin disassembler on INFO, which is a
141 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
142 optional, its default value is None. If MEMORY_SOURCE is not
143 None then it must be an object that has a 'read_memory' method.
145 - gdb.disassembler.DisassemblerResult is a class that can be used
146 to wrap the result of a call to a Disassembler. It has
147 read-only attributes 'length' and 'string'.
149 ** gdb.Objfile now has an attribute named "is_file". This is True
150 if the objfile comes from a file, and False otherwise.
152 * New features in the GDB remote stub, GDBserver
154 ** GDBserver is now supported on LoongArch GNU/Linux.
156 * LoongArch floating-point support
158 GDB now supports floating-point on LoongArch GNU/Linux.
160 *** Changes in GDB 12
162 * DBX mode is deprecated, and will be removed in GDB 13
164 * GDB 12 is the last release of GDB that will support building against
165 Python 2. From GDB 13, it will only be possible to build GDB itself
166 with Python 3 support.
168 * The disable-randomization setting now works on Windows.
170 * Improved C++ template support
172 GDB now treats functions/types involving C++ templates like it does function
173 overloads. Users may omit parameter lists to set breakpoints on families of
174 template functions, including types/functions composed of multiple template types:
176 (gdb) break template_func(template_1, int)
178 The above will set breakpoints at every function `template_func' where
179 the first function parameter is any template type named `template_1' and
180 the second function parameter is `int'.
182 TAB completion also gains similar improvements.
184 * The FreeBSD native target now supports async mode.
190 Enable or disable multithreaded symbol loading. This is enabled
191 by default, but passing --disable-threading or --enable-threading=no
192 to configure will disable it.
194 Disabling this can cause a performance penalty when there are a lot of
195 symbols to load, but is useful for debugging purposes.
199 maint set backtrace-on-fatal-signal on|off
200 maint show backtrace-on-fatal-signal
201 This setting is 'on' by default. When 'on' GDB will print a limited
202 backtrace to stderr in the situation where GDB terminates with a
203 fatal signal. This only supported on some platforms where the
204 backtrace and backtrace_symbols_fd functions are available.
206 set source open on|off
208 This setting, which is on by default, controls whether GDB will try
209 to open source code files. Switching this off will stop GDB trying
210 to open and read source code files, which can be useful if the files
211 are located over a slow network connection.
215 These are now deprecated aliases for "set max-value-size" and
216 "show max-value-size".
218 task apply [all | TASK-IDS...] [FLAG]... COMMAND
219 Like "thread apply", but applies COMMAND to Ada tasks.
222 Watchpoints can now be restricted to a specific Ada task.
224 maint set internal-error backtrace on|off
225 maint show internal-error backtrace
226 maint set internal-warning backtrace on|off
227 maint show internal-warning backtrace
228 GDB can now print a backtrace of itself when it encounters either an
229 internal-error, or an internal-warning. This is on by default for
230 internal-error and off by default for internal-warning.
233 Deprecated and replaced by "set logging enabled on|off".
235 set logging enabled on|off
237 These commands set or show whether logging is enabled or disabled.
240 You can now exit GDB by using the new command "exit", in addition to
241 the existing "quit" command.
243 set debug threads on|off
245 Print additional debug messages about thread creation and deletion.
247 set debug linux-nat on|off
249 These new commands replaced the old 'set debug lin-lwp' and 'show
250 debug lin-lwp' respectively. Turning this setting on prints debug
251 messages relating to GDB's handling of native Linux inferiors.
253 maint flush source-cache
254 Flush the contents of the source code cache.
256 maint set gnu-source-highlight enabled on|off
257 maint show gnu-source-highlight enabled
258 Whether GDB should use the GNU Source Highlight library for adding
259 styling to source code. When off, the library will not be used, even
260 when available. When GNU Source Highlight isn't used, or can't add
261 styling to a particular source file, then the Python Pygments
262 library will be used instead.
264 set suppress-cli-notifications (on|off)
265 show suppress-cli-notifications
266 This controls whether printing the notifications is suppressed for CLI.
267 CLI notifications occur when you change the selected context
268 (i.e., the current inferior, thread and/or the frame), or when
269 the program being debugged stops (e.g., because of hitting a
270 breakpoint, completing source-stepping, an interrupt, etc.).
272 set style disassembler enabled on|off
273 show style disassembler enabled
274 If GDB is compiled with Python support, and the Python Pygments
275 package is available, then, when this setting is on, disassembler
276 output will have styling applied.
278 set ada source-charset
279 show ada source-charset
280 Set the character set encoding that is assumed for Ada symbols. Valid
281 values for this follow the values that can be passed to the GNAT
282 compiler via the '-gnati' option. The default is ISO-8859-1.
288 These are the new names for the old 'layout', 'focus', 'refresh',
289 and 'winheight' tui commands respectively. The old names still
290 exist as aliases to these new commands.
294 The new command 'tui window width', and the alias 'winwidth' allow
295 the width of a tui window to be adjusted when windows are laid out
300 Control the display of debug output about GDB's tui.
305 Printing of floating-point values with base-modifying formats like
306 /x has been changed to display the underlying bytes of the value in
307 the desired base. This was GDB's documented behavior, but was never
308 implemented correctly.
311 This command can now print a reply, if the reply includes
312 non-printable characters. Any non-printable characters are printed
313 as escaped hex, e.g. \x?? where '??' is replaces with the value of
314 the non-printable character.
317 The clone-inferior command now ensures that the TTY, CMD and ARGS
318 settings are copied from the original inferior to the new one.
319 All modifications to the environment variables done using the 'set
320 environment' or 'unset environment' commands are also copied to the new
323 set debug lin-lwp on|off
325 These commands have been removed from GDB. The new command 'set
326 debug linux-nat' and 'show debug linux-nat' should be used
330 This command now includes information about the width of the tui
331 windows in its output.
337 These commands are now aliases for the 'tui layout', 'tui focus',
338 'tui refresh', and 'tui window height' commands respectively.
340 * GDB's Ada parser now supports an extension for specifying the exact
341 byte contents of a floating-point literal. This can be useful for
342 setting floating-point registers to a precise value without loss of
343 precision. The syntax is an extension of the based literal syntax.
344 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
345 of the floating-point type, and the "f" is the marker for floating
350 ** The '-add-inferior' with no option flags now inherits the
351 connection of the current inferior, this restores the behaviour of
352 GDB as it was prior to GDB 10.
354 ** The '-add-inferior' command now accepts a '--no-connection'
355 option, which causes the new inferior to start without a
360 GNU/Linux/LoongArch loongarch*-*-linux*
368 ** New function gdb.add_history(), which takes a gdb.Value object
369 and adds the value it represents to GDB's history list. An
370 integer, the index of the new item in the history list, is
373 ** New function gdb.history_count(), which returns the number of
374 values in GDB's value history.
376 ** New gdb.events.gdb_exiting event. This event is called with a
377 gdb.GdbExitingEvent object which has the read-only attribute
378 'exit_code', which contains the value of the GDB exit code. This
379 event is triggered once GDB decides it is going to exit, but
380 before GDB starts to clean up its internal state.
382 ** New function gdb.architecture_names(), which returns a list
383 containing all of the possible Architecture.name() values. Each
386 ** New function gdb.Architecture.integer_type(), which returns an
387 integer type given a size and a signed-ness.
389 ** New gdb.TargetConnection object type that represents a connection
390 (as displayed by the 'info connections' command). A sub-class,
391 gdb.RemoteTargetConnection, is used to represent 'remote' and
392 'extended-remote' connections.
394 ** The gdb.Inferior type now has a 'connection' property which is an
395 instance of gdb.TargetConnection, the connection used by this
396 inferior. This can be None if the inferior has no connection.
398 ** New 'gdb.events.connection_removed' event registry, which emits a
399 'gdb.ConnectionEvent' when a connection is removed from GDB.
400 This event has a 'connection' property, a gdb.TargetConnection
401 object for the connection being removed.
403 ** New gdb.connections() function that returns a list of all
404 currently active connections.
406 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
407 is equivalent to the existing 'maint packet' CLI command; it
408 allows a user specified packet to be sent to the remote target.
410 ** New function gdb.host_charset(), returns a string, which is the
411 name of the current host charset.
413 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
416 ** New gdb.with_parameter(NAME, VALUE). This returns a context
417 manager that temporarily sets the gdb parameter NAME to VALUE,
418 then resets it when the context is exited.
420 ** The gdb.Value.format_string method now takes a 'styling'
421 argument, which is a boolean. When true, the returned string can
422 include escape sequences to apply styling. The styling will only
423 be present if styling is otherwise turned on in GDB (see 'help
424 set styling'). When false, which is the default if the argument
425 is not given, then no styling is applied to the returned string.
427 ** New read-only attribute gdb.InferiorThread.details, which is
428 either a string, containing additional, target specific thread
429 state information, or None, if there is no such additional
432 ** New read-only attribute gdb.Type.is_scalar, which is True for
433 scalar types, and False for all other types.
435 ** New read-only attribute gdb.Type.is_signed. This attribute
436 should only be read when Type.is_scalar is True, and will be True
437 for signed types, and False for all other types. Attempting to
438 read this attribute for non-scalar types will raise a ValueError.
440 ** It is now possible to add GDB/MI commands implemented in Python.
442 * New features in the GDB remote stub, GDBserver
444 ** GDBserver is now supported on OpenRISC GNU/Linux.
446 * New native configurations
448 GNU/Linux/OpenRISC or1k*-*-linux*
450 *** Changes in GDB 11
452 * The 'set disassembler-options' command now supports specifying options
455 * GDB now supports general memory tagging functionality if the underlying
456 architecture supports the proper primitives and hooks. Currently this is
457 enabled only for AArch64 MTE.
461 - Additional information when the inferior crashes with a SIGSEGV caused by
462 a memory tag violation.
464 - A new modifier 'm' for the "x" command, which displays allocation tags for a
465 particular memory range.
467 - Display of memory tag mismatches by "print", for addresses and
468 pointers, if memory tagging is supported by the architecture.
470 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
475 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
477 The MI -break-insert and -dprintf-insert commands now support a
478 new "--qualified" option that makes GDB interpret a specified
479 function name as a complete fully-qualified name. This is the
480 equivalent of the CLI's "break -qualified" and "dprintf
483 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
485 The MI -break-insert and -dprintf-insert commands now support a
486 '--force-condition' flag to forcibly define a condition even when
487 the condition is invalid at all locations of the breakpoint. This
488 is equivalent to the '-force-condition' flag of the CLI's "break"
491 ** '-break-condition --force'
493 The MI -break-condition command now supports a '--force' flag to
494 forcibly define a condition even when the condition is invalid at
495 all locations of the selected breakpoint. This is equivalent to
496 the '-force' flag of the CLI's "cond" command.
498 ** '-file-list-exec-source-files [--group-by-objfile]
499 [--basename | --dirname]
502 The existing -file-list-exec-source-files command now takes an
503 optional REGEXP which is used to filter the source files that are
504 included in the results.
506 By default REGEXP is matched against the full filename of the
507 source file. When one of --basename or --dirname is given then
508 REGEXP is only matched against the specified part of the full
511 When the optional --group-by-objfile flag is used the output
512 format is changed, the results are now a list of object files
513 (executable and libraries) with the source files that are
514 associated with each object file.
516 The results from -file-list-exec-source-files now include a
517 'debug-fully-read' field which takes the value 'true' or 'false'.
518 A 'true' value indicates the source file is from a compilation
519 unit that has had its debug information fully read in by GDB, a
520 value of 'false' indicates GDB has only performed a partial scan
521 of the debug information so far.
523 * GDB now supports core file debugging for x86_64 Cygwin programs.
525 * GDB will now look for the .gdbinit file in a config directory before
526 looking for ~/.gdbinit. The file is searched for in the following
527 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
528 $HOME/.gdbinit. On Apple hosts the search order is instead:
529 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
531 * GDB now supports fixed point types which are described in DWARF
532 as base types with a fixed-point encoding. Additionally, support
533 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
536 For Ada, this allows support for fixed point types without requiring
537 the use of the GNAT encoding (based on information added to the type's
538 name following a GNAT-specific format).
540 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
541 or ~/.gdbearlyinit if these files are present. These files are
542 processed earlier than any of the other initialization files and
543 can affect parts of GDB's startup that previously had already been
544 completed before the initialization files were read, for example
545 styling of the initial GDB greeting.
547 * GDB now has two new options "--early-init-command" and
548 "--early-init-eval-command" with corresponding short options "-eix"
549 and "-eiex" that allow options (that would normally appear in a
550 gdbearlyinit file) to be passed on the command line.
552 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
553 now understood by GDB, and can be used to describe the vector
554 registers of a target. The precise requirements of this register
555 feature are documented in the GDB manual.
557 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
558 supported by GDB and describes a new VPR register from the ARM MVE
559 (Helium) extension. See the GDB manual for more information.
563 ** TUI windows now support mouse actions. The mouse wheel scrolls
564 the appropriate window.
566 ** Key combinations that do not have a specific action on the
567 focused window are passed to GDB. For example, you now can use
568 Ctrl-Left/Ctrl-Right to move between words in the command window
569 regardless of which window is in focus. Previously you would
570 need to focus on the command window for such key combinations to
576 show debug event-loop
577 Control the display of debug output about GDB's event loop.
579 set print memory-tag-violations
580 show print memory-tag-violations
581 Control whether to display additional information about memory tag violations
582 when printing pointers and addresses. Architecture support for memory
583 tagging is required for this option to have an effect.
585 maintenance flush symbol-cache
586 maintenance flush register-cache
587 These new commands are equivalent to the already existing commands
588 'maintenance flush-symbol-cache' and 'flushregs' respectively.
590 maintenance flush dcache
591 A new command to flush the dcache.
593 maintenance info target-sections
594 Print GDB's internal target sections table.
597 Print the JIT code objects in the inferior known to GDB.
599 memory-tag show-logical-tag POINTER
600 Print the logical tag for POINTER.
601 memory-tag with-logical-tag POINTER TAG
602 Print POINTER with logical tag TAG.
603 memory-tag show-allocation-tag ADDRESS
604 Print the allocation tag for ADDRESS.
605 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
606 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
607 memory-tag check POINTER
608 Validate that POINTER's logical tag matches the allocation tag.
610 set startup-quietly on|off
612 When 'on', this causes GDB to act as if "-silent" were passed on the
613 command line. This command needs to be added to an early
614 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
617 set print type hex on|off
619 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
620 and offsets of struct members. When 'off', decimal notation is used.
622 set python ignore-environment on|off
623 show python ignore-environment
624 When 'on', this causes GDB's builtin Python to ignore any
625 environment variables that would otherwise affect how Python
626 behaves. This command needs to be added to an early initialization
627 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
629 set python dont-write-bytecode auto|on|off
630 show python dont-write-bytecode
631 When 'on', this causes GDB's builtin Python to not write any
632 byte-code (.pyc files) to disk. This command needs to be added to
633 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
634 order to affect GDB. When 'off' byte-code will always be written.
635 When set to 'auto' (the default) Python will check the
636 PYTHONDONTWRITEBYTECODE environment variable.
640 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
641 [-force-condition] [if CONDITION]
642 This command would previously refuse setting a breakpoint if the
643 CONDITION expression is invalid at a location. It now accepts and
644 defines the breakpoint if there is at least one location at which
645 the CONDITION is valid. The locations for which the CONDITION is
646 invalid, are automatically disabled. If CONDITION is invalid at all
647 of the locations, setting the breakpoint is still rejected. However,
648 the '-force-condition' flag can be used in this case for forcing GDB to
649 define the breakpoint, making all the current locations automatically
650 disabled. This may be useful if the user knows the condition will
651 become meaningful at a future location, e.g. due to a shared library
654 condition [-force] N COND
655 The behavior of this command is changed the same way for the 'break'
656 command as explained above. The '-force' flag can be used to force
657 GDB into defining the condition even when COND is invalid for all the
658 current locations of breakpoint N.
661 maintenance flush-symbol-cache
662 These commands are deprecated in favor of the new commands
663 'maintenance flush register-cache' and 'maintenance flush
664 symbol-cache' respectively.
666 set style version foreground COLOR
667 set style version background COLOR
668 set style version intensity VALUE
669 Control the styling of GDB's version number text.
672 When the ID parameter is omitted, then this command prints information
673 about the current inferior. When the ID parameter is present, the
674 behavior of the command is unchanged and have the inferior ID become
675 the current inferior.
677 maintenance info sections
678 The ALLOBJ keyword has been replaced with an -all-objects command
679 line flag. It is now possible to filter which sections are printed
680 even when -all-objects is passed.
682 ptype[/FLAGS] TYPE | EXPRESSION
683 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
684 notation is used when printing sizes and offsets of struct members.
685 When '/d' is set, decimal notation is used when printing sizes and
686 offsets of struct members. Default behavior is given by 'show print
690 The info sources command output has been restructured. The results
691 are now based around a list of objfiles (executable and libraries),
692 and for each objfile the source files that are part of that objfile
695 * Removed targets and native configurations
697 ARM Symbian arm*-*-symbianelf*
702 Request the remote to send allocation tags for a particular memory range.
704 Request the remote to store the specified allocation tags to the requested
709 ** Improved support for rvalue reference values:
710 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
711 value-referenced-value procedure now handles rvalue reference
714 ** New procedures for obtaining value variants:
715 value-reference-value, value-rvalue-reference-value and
718 ** Temporary breakpoints can now be created with make-breakpoint and
719 tested for using breakpoint-temporary?.
723 ** Inferior objects now contain a read-only 'connection_num' attribute that
724 gives the connection number as seen in 'info connections' and
727 ** New method gdb.Frame.level() which returns the stack level of the
730 ** New method gdb.PendingFrame.level() which returns the stack level
733 ** When hitting a catchpoint, the Python API will now emit a
734 gdb.BreakpointEvent rather than a gdb.StopEvent. The
735 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
737 ** Python TUI windows can now receive mouse click events. If the
738 Window object implements the click method, it is called for each
739 mouse click event in this window.
741 *** Changes in GDB 10
743 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
744 and "org.gnu.gdb.arc.aux". The old names are still supported but
745 must be considered obsolete. They will be deprecated after some
748 * Help and apropos commands will now show the documentation of a
749 command only once, even if that command has one or more aliases.
750 These commands now show the command name, then all of its aliases,
751 and finally the description of the command.
753 * 'help aliases' now shows only the user defined aliases. GDB predefined
754 aliases are shown together with their aliased command.
756 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
757 debugging information as well as source code.
759 When built with debuginfod, GDB can automatically query debuginfod
760 servers for the separate debug files and source code of the executable
763 To build GDB with debuginfod, pass --with-debuginfod to configure (this
764 requires libdebuginfod, the debuginfod client library).
766 debuginfod is distributed with elfutils, starting with version 0.178.
768 You can get the latest version from https://sourceware.org/elfutils.
770 * Multi-target debugging support
772 GDB now supports debugging multiple target connections
773 simultaneously. For example, you can now have each inferior
774 connected to different remote servers running in different machines,
775 or have one inferior debugging a local native process, an inferior
776 debugging a core dump, etc.
778 This support is experimental and comes with some limitations -- you
779 can only resume multiple targets simultaneously if all targets
780 support non-stop mode, and all remote stubs or servers must support
781 the same set of remote protocol features exactly. See also "info
782 connections" and "add-inferior -no-connection" below, and "maint set
783 target-non-stop" in the user manual.
785 * New features in the GDB remote stub, GDBserver
787 ** GDBserver is now supported on ARC GNU/Linux.
789 ** GDBserver is now supported on RISC-V GNU/Linux.
791 ** GDBserver no longer supports these host triplets:
802 i[34567]86-*-mingw32ce*
804 * Debugging MS-Windows processes now sets $_exitsignal when the
805 inferior is terminated by a signal, instead of setting $_exitcode.
807 * Multithreaded symbol loading has now been enabled by default on systems
808 that support it (see entry for GDB 9, below), providing faster
809 performance for programs with many symbols.
811 * The $_siginfo convenience variable now also works on Windows targets,
812 and will display the EXCEPTION_RECORD of the last handled exception.
814 * TUI windows can now be arranged horizontally.
816 * The command history filename can now be set to the empty string
817 either using 'set history filename' or by setting 'GDBHISTFILE=' in
818 the environment. The effect of setting this filename to the empty
819 string is that GDB will not try to load any previous command
822 * On Windows targets, it is now possible to debug 32-bit programs with a
827 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
828 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
829 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
830 running process, this new option indicates whether to detect
831 a mismatch between the current executable file loaded by GDB and the
832 executable file used to start the process. If 'ask', the default,
833 display a warning and ask the user whether to load the process
834 executable file; if 'warn', just display a warning; if 'off', don't
835 attempt to detect a mismatch.
837 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
838 Define a new TUI layout, specifying its name and the windows that
841 maintenance print xml-tdesc [FILE]
842 Prints the current target description as an XML document. If the
843 optional FILE is provided (which is an XML target description) then
844 the target description is read from FILE into GDB, and then
847 maintenance print core-file-backed-mappings
848 Prints file-backed mappings loaded from a core file's note section.
849 Output is expected to be similar to that of "info proc mappings".
851 set debug fortran-array-slicing on|off
852 show debug fortran-array-slicing
853 Print debugging when taking slices of Fortran arrays.
855 set fortran repack-array-slices on|off
856 show fortran repack-array-slices
857 When taking slices from Fortran arrays and strings, if the slice is
858 non-contiguous within the original value then, when this option is
859 on, the new value will be repacked into a single contiguous value.
860 When this option is off, then the value returned will consist of a
861 descriptor that describes the slice within the memory of the
862 original parent value.
866 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
867 The alias command can now specify default args for an alias.
868 GDB automatically prepends the alias default args to the argument list
869 provided explicitly by the user.
870 For example, to have a backtrace with full details, you can define
872 'alias bt_ALL = backtrace -entry-values both -frame-arg all
873 -past-main -past-entry -full'.
874 Alias default arguments can also use a set of nested 'with' commands,
875 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
876 defines the alias pp10 that will pretty print a maximum of 10 elements
877 of the given expression (if the expression is an array).
881 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
887 ** gdb.register_window_type can be used to implement new TUI windows
890 ** Dynamic types can now be queried. gdb.Type has a new attribute,
891 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
892 field of a dynamic type may have None for its "bitpos" attribute
895 ** Commands written in Python can be in the "TUI" help class by
896 registering with the new constant gdb.COMMAND_TUI.
898 ** New method gdb.PendingFrame.architecture () to retrieve the
899 architecture of the pending frame.
901 ** New gdb.Architecture.registers method that returns a
902 gdb.RegisterDescriptorIterator object, an iterator that returns
903 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
904 way to query the registers available for an architecture.
906 ** New gdb.Architecture.register_groups method that returns a
907 gdb.RegisterGroupIterator object, an iterator that returns
908 gdb.RegisterGroup objects. The new RegisterGroup is a way to
909 discover the available register groups.
913 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
915 ** Procedures 'memory-port-read-buffer-size',
916 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
917 and 'set-memory-port-write-buffer-size!' are deprecated. When
918 using Guile 2.2 and later, users who need to control the size of
919 a memory port's internal buffer can use the 'setvbuf' procedure.
923 * 'thread-exited' event is now available in the annotations interface.
925 * New built-in convenience variables $_gdb_major and $_gdb_minor
926 provide the GDB version. They are handy for conditionally using
927 features available only in or since specific GDB versions, in
928 scripts that should work error-free with many different versions,
929 such as in system-wide init files.
931 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
932 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
933 of the GDB settings and the GDB maintenance settings. They are handy
934 for changing the logic of user defined commands depending on the
935 current GDB settings.
937 * GDB now supports Thread Local Storage (TLS) variables on several
938 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
939 architectures require kernel changes. TLS is not yet supported for
940 amd64 and i386 process core dumps.
942 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
943 addresses that required unmasking are shown in the backtrace with the
946 * Two new convenience functions $_cimag and $_creal that extract the
947 imaginary and real parts respectively from complex numbers.
949 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
950 provide the exitcode or exit status of the shell commands launched by
951 GDB commands such as "shell", "pipe" and "make".
953 * The command define-prefix can now define user defined prefix commands.
954 User defined commands can now be defined using these user defined prefix
957 * Command names can now use the . character.
959 * The RX port now supports XML target descriptions.
961 * GDB now shows the Ada task names at more places, e.g. in task switching
964 * GDB can now be compiled with Python 3 on Windows.
966 * New convenience variable $_ada_exception holds the address of the
967 Ada exception being thrown. This is set by Ada-related catchpoints.
969 * GDB can now place breakpoints on nested functions and subroutines in
970 Fortran code. The '::' operator can be used between parent and
971 child scopes when placing breakpoints, for example:
973 (gdb) break outer_function::inner_function
975 The 'outer_function::' prefix is only needed if 'inner_function' is
976 not visible in the current scope.
978 * In addition to the system-wide gdbinit file, if configured with
979 --with-system-gdbinit-dir, GDB will now also load files in that directory
980 as system gdbinit files, unless the -nx or -n flag is provided. Files
981 with extensions .gdb, .py and .scm are supported as long as GDB was
982 compiled with support for that language.
984 * GDB now supports multithreaded symbol loading for higher performance.
985 This feature is still in testing, so it is disabled by default. You
986 can turn it on using 'maint set worker-threads unlimited'.
990 ** The gdb.Value type has a new method 'format_string' which returns a
991 string representing the value. The formatting is controlled by the
992 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
993 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
994 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
996 ** gdb.Type has a new property 'objfile' which returns the objfile the
999 ** The frame information printed by the python frame filtering code
1000 is now consistent with what the 'backtrace' command prints when
1001 there are no filters, or when the 'backtrace' '-no-filters' option
1004 ** The new function gdb.lookup_static_symbol can be used to look up
1005 symbols with static linkage.
1007 ** The new function gdb.lookup_static_symbols can be used to look up
1008 all static symbols with static linkage.
1010 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1011 'lookup_static_symbol' to lookup a symbol from this objfile only.
1013 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1014 this block (e.g. block['local_variable']).
1018 | [COMMAND] | SHELL_COMMAND
1019 | -d DELIM COMMAND DELIM SHELL_COMMAND
1020 pipe [COMMAND] | SHELL_COMMAND
1021 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1022 Executes COMMAND and sends its output to SHELL_COMMAND.
1023 With no COMMAND, repeat the last executed command
1024 and send its output to SHELL_COMMAND.
1026 define-prefix COMMAND
1027 Define or mark a command as a user-defined prefix command.
1029 with SETTING [VALUE] [-- COMMAND]
1030 w SETTING [VALUE] [-- COMMAND]
1031 Temporarily set SETTING, run COMMAND, and restore SETTING.
1032 Usage: with SETTING -- COMMAND
1033 With no COMMAND, repeats the last executed command.
1034 SETTING is any GDB setting you can change with the "set"
1035 subcommands. For example, 'with language c -- print someobj'
1036 temporarily switches to the C language in order to print someobj.
1037 Settings can be combined: 'w lang c -- w print elements unlimited --
1038 usercmd' switches to the C language and runs usercmd with no limit
1039 of array elements to print.
1041 maint with SETTING [VALUE] [-- COMMAND]
1042 Like "with", but works with "maintenance set" settings.
1044 set may-call-functions [on|off]
1045 show may-call-functions
1046 This controls whether GDB will attempt to call functions in
1047 the program, such as with expressions in the print command. It
1048 defaults to on. Calling functions in the program being debugged
1049 can have undesired side effects. It is now possible to forbid
1050 such function calls. If function calls are forbidden, GDB will throw
1051 an error when a command (such as print expression) calls a function
1054 set print finish [on|off]
1056 This controls whether the `finish' command will display the value
1057 that is returned by the current function. When `off', the value is
1058 still entered into the value history, but it is not printed. The
1062 show print max-depth
1063 Allows deeply nested structures to be simplified when printing by
1064 replacing deeply nested parts (beyond the max-depth) with ellipses.
1065 The default max-depth is 20, but this can be set to unlimited to get
1066 the old behavior back.
1068 set print raw-values [on|off]
1069 show print raw-values
1070 By default, GDB applies the enabled pretty printers when printing a
1071 value. This allows to ignore the enabled pretty printers for a series
1072 of commands. The default is 'off'.
1074 set logging debugredirect [on|off]
1075 By default, GDB debug output will go to both the terminal and the logfile.
1076 Set if you want debug output to go only to the log file.
1078 set style title foreground COLOR
1079 set style title background COLOR
1080 set style title intensity VALUE
1081 Control the styling of titles.
1083 set style highlight foreground COLOR
1084 set style highlight background COLOR
1085 set style highlight intensity VALUE
1086 Control the styling of highlightings.
1088 maint set worker-threads
1089 maint show worker-threads
1090 Control the number of worker threads that can be used by GDB. The
1091 default is 0. "unlimited" lets GDB choose a number that is
1092 reasonable. Currently worker threads are only used when demangling
1093 the names of linker symbols.
1095 set style tui-border foreground COLOR
1096 set style tui-border background COLOR
1097 Control the styling of TUI borders.
1099 set style tui-active-border foreground COLOR
1100 set style tui-active-border background COLOR
1101 Control the styling of the active TUI border.
1103 maint set test-settings KIND
1104 maint show test-settings KIND
1105 A set of commands used by the testsuite for exercising the settings
1108 maint set tui-resize-message [on|off]
1109 maint show tui-resize-message
1110 Control whether GDB prints a message each time the terminal is
1111 resized when in TUI mode. This is primarily useful for testing the
1114 set print frame-info [short-location|location|location-and-address
1115 |source-and-location|source-line|auto]
1116 show print frame-info
1117 This controls what frame information is printed by the commands printing
1118 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1119 'frame', 'stepi'. The python frame filtering also respect this setting.
1120 The 'backtrace' '-frame-info' option can override this global setting.
1122 set tui compact-source
1123 show tui compact-source
1125 Enable the "compact" display mode for the TUI source window. The
1126 compact display uses only as much space as is needed for the line
1127 numbers in the current file, and only a single space to separate the
1128 line numbers from the source.
1130 info modules [-q] [REGEXP]
1131 Return a list of Fortran modules matching REGEXP, or all modules if
1134 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1135 Return a list of functions within all modules, grouped by module.
1136 The list of functions can be restricted with the optional regular
1137 expressions. MODULE_REGEXP matches against the module name,
1138 TYPE_REGEXP matches against the function type signature, and REGEXP
1139 matches against the function name.
1141 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1142 Return a list of variables within all modules, grouped by module.
1143 The list of variables can be restricted with the optional regular
1144 expressions. MODULE_REGEXP matches against the module name,
1145 TYPE_REGEXP matches against the variable type, and REGEXP matches
1146 against the variable name.
1148 set debug remote-packet-max-chars
1149 show debug remote-packet-max-chars
1150 Controls the number of characters to output in a remote packet when using
1152 The default is 512 bytes.
1155 Lists the target connections currently in use.
1160 The "help" command uses the title style to enhance the
1161 readibility of its output by styling the classes and
1165 Similarly to "help", the "apropos" command also uses the
1166 title style for the command names. "apropos" accepts now
1167 a flag "-v" (verbose) to show the full documentation
1168 of matching commands and to use the highlight style to mark
1169 the documentation parts matching REGEXP.
1173 The GDB printf and eval commands can now print C-style and Ada-style
1174 string convenience variables without calling functions in the program.
1175 This allows to do formatted printing of strings without having
1176 a running inferior, or when debugging a core dump.
1178 info sources [-dirname | -basename] [--] [REGEXP]
1179 This command has now optional arguments to only print the files
1180 whose names match REGEXP. The arguments -dirname and -basename
1181 allow to restrict matching respectively to the dirname and basename
1185 The "show style" and its subcommands are now styling
1186 a style name in their output using its own style, to help
1187 the user visualize the different styles.
1189 set print frame-arguments
1190 The new value 'presence' indicates to only indicate the presence of
1191 arguments using ..., instead of printing argument names and values.
1193 set print raw-frame-arguments
1194 show print raw-frame-arguments
1196 These commands replace the similarly-named "set/show print raw
1197 frame-arguments" commands (now with a dash instead of a space). The
1198 old commands are now deprecated and may be removed in a future
1201 add-inferior [-no-connection]
1202 The add-inferior command now supports a "-no-connection" flag that
1203 makes the new inferior start with no target connection associated.
1204 By default, the new inferior inherits the target connection of the
1205 current inferior. See also "info connections".
1208 This command's output now includes a new "Connection" column
1209 indicating which target connection an inferior is bound to. See
1210 "info connections" above.
1212 maint test-options require-delimiter
1213 maint test-options unknown-is-error
1214 maint test-options unknown-is-operand
1215 maint show test-options-completion-result
1216 Commands used by the testsuite to validate the command options
1219 focus, winheight, +, -, >, <
1220 These commands are now case-sensitive.
1222 * New command options, command completion
1224 GDB now has a standard infrastructure to support dash-style command
1225 options ('-OPT'). One benefit is that commands that use it can
1226 easily support completion of command line arguments. Try "CMD
1227 -[TAB]" or "help CMD" to find options supported by a command. Over
1228 time, we intend to migrate most commands to this infrastructure. A
1229 number of commands got support for new command options in this
1232 ** The "print" and "compile print" commands now support a number of
1233 options that allow overriding relevant global print settings as
1234 set by "set print" subcommands:
1238 -array-indexes [on|off]
1239 -elements NUMBER|unlimited
1243 -raw-values [on|off]
1244 -repeats NUMBER|unlimited
1245 -static-members [on|off]
1250 Note that because the "print"/"compile print" commands accept
1251 arbitrary expressions which may look like options (including
1252 abbreviations), if you specify any command option, then you must
1253 use a double dash ("--") to mark the end of argument processing.
1255 ** The "backtrace" command now supports a number of options that
1256 allow overriding relevant global print settings as set by "set
1257 backtrace" and "set print" subcommands:
1259 -entry-values no|only|preferred|if-needed|both|compact|default
1260 -frame-arguments all|scalars|none
1261 -raw-frame-arguments [on|off]
1262 -frame-info auto|source-line|location|source-and-location
1263 |location-and-address|short-location
1265 -past-entry [on|off]
1267 In addition, the full/no-filters/hide qualifiers are now also
1268 exposed as command options too:
1274 ** The "frame apply", "tfaas" and "faas" commands similarly now
1275 support the following options:
1278 -past-entry [on|off]
1280 ** The new "info sources" options -dirname and -basename options
1281 are using the standard '-OPT' infrastructure.
1283 All options above can also be abbreviated. The argument of boolean
1284 (on/off) options can be 0/1 too, and also the argument is assumed
1285 "on" if omitted. This allows writing compact command invocations,
1288 (gdb) p -ra -p -o 0 -- *myptr
1290 The above is equivalent to:
1292 (gdb) print -raw-values -pretty -object off -- *myptr
1294 ** The "info types" command now supports the '-q' flag to disable
1295 printing of some header information in a similar fashion to "info
1296 variables" and "info functions".
1298 ** The "info variables", "info functions", and "whereis" commands
1299 now take a '-n' flag that excludes non-debug symbols (symbols
1300 from the symbol table, not from the debug info such as DWARF)
1303 * Completion improvements
1305 ** GDB can now complete the options of the "thread apply all" and
1306 "taas" commands, and their "-ascending" option can now be
1309 ** GDB can now complete the options of the "info threads", "info
1310 functions", "info variables", "info locals", and "info args"
1313 ** GDB can now complete the options of the "compile file" and
1314 "compile code" commands. The "compile file" command now
1315 completes on filenames.
1317 ** GDB can now complete the backtrace command's
1318 "full/no-filters/hide" qualifiers.
1320 * In settings, you can now abbreviate "unlimited".
1322 E.g., "set print elements u" is now equivalent to "set print
1323 elements unlimited".
1328 This lists all the possible completions for the rest of the line, if it
1329 were to be given as a command itself. This is intended for use by MI
1330 frontends in cases when separate CLI and MI channels cannot be used.
1332 -catch-throw, -catch-rethrow, and -catch-catch
1333 These can be used to catch C++ exceptions in a similar fashion to
1334 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1336 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1337 These commands are the MI equivalent of the CLI commands 'info
1338 functions', 'info types', and 'info variables' respectively.
1340 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1343 -symbol-info-module-functions and -symbol-info-module-variables.
1344 These commands are the MI equivalent of the CLI commands 'info
1345 module functions' and 'info module variables'.
1349 ** The default version of the MI interpreter is now 3 (-i=mi3).
1351 ** The output of information about multi-location breakpoints (which is
1352 syntactically incorrect in MI 2) has changed in MI 3. This affects
1353 the following commands and events:
1357 - =breakpoint-created
1358 - =breakpoint-modified
1360 The -fix-multi-location-breakpoint-output command can be used to enable
1361 this behavior with previous MI versions.
1363 ** Backtraces and frames include a new optional field addr_flags which is
1364 given after the addr field. On AArch64 this contains PAC if the address
1365 has been masked in the frame. On all other targets the field is not
1370 The testsuite now creates the files gdb.cmd (containing the arguments
1371 used to launch GDB) and gdb.in (containing all the commands sent to
1372 GDB) in the output directory for each test script. Multiple invocations
1373 are appended with .1, .2, .3 etc.
1375 * Building GDB and GDBserver now requires GNU make >= 3.82.
1377 Using another implementation of the make program or an earlier version of
1378 GNU make to build GDB or GDBserver is not supported.
1380 * Building GDB now requires GNU readline >= 7.0.
1382 GDB now bundles GNU readline 8.0, but if you choose to use
1383 --with-system-readline, only readline >= 7.0 can be used.
1385 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1386 from .inputrc to bind keys in this keymap. This feature is only
1387 available when gdb is built against GNU readline 8.0 or later.
1389 * Removed targets and native configurations
1391 GDB no longer supports debugging the Cell Broadband Engine. This includes
1392 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1393 of Cell/B.E. applications that use both the PPU and SPU architectures.
1399 * Removed targets and native configurations
1401 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1402 sparc*-*-solaris2.10
1404 *** Changes in GDB 8.3
1406 * GDB and GDBserver now support access to additional registers on
1407 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1410 * GDB now has experimental support for the compilation and injection of
1411 C++ source code into the inferior. This beta release does not include
1412 support for several language features, such as templates, constructors,
1415 This feature requires GCC 7.1 or higher built with libcp1.so
1418 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1419 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1420 'ADDRESS:PORT' method.
1422 * DWARF index cache: GDB can now automatically save indices of DWARF
1423 symbols on disk to speed up further loading of the same binaries.
1425 * Ada task switching is now supported on aarch64-elf targets when
1426 debugging a program using the Ravenscar Profile. For more information,
1427 see the "Tasking Support when using the Ravenscar Profile" section
1428 in the GDB user manual.
1430 * GDB in batch mode now exits with status 1 if the last command to be
1433 * The RISC-V target now supports target descriptions.
1435 * System call catchpoints now support system call aliases on FreeBSD.
1436 When the ABI of a system call changes in FreeBSD, this is
1437 implemented by leaving a compatibility system call using the old ABI
1438 at the existing number and allocating a new system call number for
1439 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1440 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1441 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1442 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1443 so that a system call catchpoint for the 'kevent' system call will
1444 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1445 binaries. This ensures that 'kevent' system calls are caught for
1446 binaries using either the old or new ABIs.
1448 * Terminal styling is now available for the CLI and the TUI. GNU
1449 Source Highlight can additionally be used to provide styling of
1450 source code snippets. See the "set style" commands, below, for more
1453 * Removed support for old demangling styles arm, edg, gnu, hp and
1458 set debug compile-cplus-types
1459 show debug compile-cplus-types
1460 Control the display of debug output about type conversion in the
1461 C++ compile feature. Commands have no effect while compiling
1462 for other languages.
1466 Control whether debug output about files/functions skipping is
1469 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1470 Apply a command to some frames.
1471 FLAG arguments allow to control what output to produce and how to handle
1472 errors raised when applying COMMAND to a frame.
1475 Apply a command to all threads (ignoring errors and empty output).
1476 Shortcut for 'thread apply all -s COMMAND'.
1479 Apply a command to all frames (ignoring errors and empty output).
1480 Shortcut for 'frame apply all -s COMMAND'.
1483 Apply a command to all frames of all threads (ignoring errors and empty
1485 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1487 maint set dwarf unwinders (on|off)
1488 maint show dwarf unwinders
1489 Control whether DWARF unwinders can be used.
1492 Display a list of open files for a process.
1496 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1497 These commands all now take a frame specification which
1498 is either a frame level, or one of the keywords 'level', 'address',
1499 'function', or 'view' followed by a parameter. Selecting a frame by
1500 address, or viewing a frame outside the current backtrace now
1501 requires the use of a keyword. Selecting a frame by level is
1502 unchanged. The MI comment "-stack-select-frame" is unchanged.
1504 target remote FILENAME
1505 target extended-remote FILENAME
1506 If FILENAME is a Unix domain socket, GDB will attempt to connect
1507 to this socket instead of opening FILENAME as a character device.
1509 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1510 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1511 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1512 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1513 These commands can now print only the searched entities
1514 matching the provided regexp(s), giving a condition
1515 on the entity names or entity types. The flag -q disables
1516 printing headers or informations messages.
1522 These commands now determine the syntax for the shown entities
1523 according to the language chosen by `set language'. In particular,
1524 `set language auto' means to automatically choose the language of
1527 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1528 The 'thread apply' command accepts new FLAG arguments.
1529 FLAG arguments allow to control what output to produce and how to handle
1530 errors raised when applying COMMAND to a thread.
1532 set tui tab-width NCHARS
1533 show tui tab-width NCHARS
1534 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1536 set style enabled [on|off]
1538 Enable or disable terminal styling. Styling is enabled by default
1539 on most hosts, but disabled by default when in batch mode.
1541 set style sources [on|off]
1543 Enable or disable source code styling. Source code styling is
1544 enabled by default, but only takes effect if styling in general is
1545 enabled, and if GDB was linked with GNU Source Highlight.
1547 set style filename foreground COLOR
1548 set style filename background COLOR
1549 set style filename intensity VALUE
1550 Control the styling of file names.
1552 set style function foreground COLOR
1553 set style function background COLOR
1554 set style function intensity VALUE
1555 Control the styling of function names.
1557 set style variable foreground COLOR
1558 set style variable background COLOR
1559 set style variable intensity VALUE
1560 Control the styling of variable names.
1562 set style address foreground COLOR
1563 set style address background COLOR
1564 set style address intensity VALUE
1565 Control the styling of addresses.
1569 ** The '-data-disassemble' MI command now accepts an '-a' option to
1570 disassemble the whole function surrounding the given program
1571 counter value or function name. Support for this feature can be
1572 verified by using the "-list-features" command, which should
1573 contain "data-disassemble-a-option".
1575 ** Command responses and notifications that include a frame now include
1576 the frame's architecture in a new "arch" attribute.
1578 * New native configurations
1580 GNU/Linux/RISC-V riscv*-*-linux*
1581 FreeBSD/riscv riscv*-*-freebsd*
1585 GNU/Linux/RISC-V riscv*-*-linux*
1586 CSKY ELF csky*-*-elf
1587 CSKY GNU/LINUX csky*-*-linux
1588 FreeBSD/riscv riscv*-*-freebsd*
1590 GNU/Linux/OpenRISC or1k*-*-linux*
1594 GDB no longer supports native debugging on versions of MS-Windows
1599 ** GDB no longer supports Python versions less than 2.6.
1601 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1602 space associated to that inferior.
1604 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1605 of objfiles associated to that program space.
1607 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1608 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1611 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1612 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1613 correct and did not work properly.
1615 ** The gdb.Value type has a new constructor, which is used to construct a
1616 gdb.Value from a Python buffer object and a gdb.Type.
1622 Enable or disable the undefined behavior sanitizer. This is
1623 disabled by default, but passing --enable-ubsan=yes or
1624 --enable-ubsan=auto to configure will enable it. Enabling this can
1625 cause a performance penalty. The undefined behavior sanitizer was
1626 first introduced in GCC 4.9.
1628 *** Changes in GDB 8.2
1630 * The 'set disassembler-options' command now supports specifying options
1631 for the MIPS target.
1633 * The 'symbol-file' command now accepts an '-o' option to add a relative
1634 offset to all sections.
1636 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1637 a relative offset to all sections, but it allows to override the load
1638 address of individual sections using '-s'.
1640 * The 'add-symbol-file' command no longer requires the second argument
1641 (address of the text section).
1643 * The endianness used with the 'set endian auto' mode in the absence of
1644 an executable selected for debugging is now the last endianness chosen
1645 either by one of the 'set endian big' and 'set endian little' commands
1646 or by inferring from the last executable used, rather than the startup
1649 * The pager now allows a "c" response, meaning to disable the pager
1650 for the rest of the current command.
1652 * The commands 'info variables/functions/types' now show the source line
1653 numbers of symbol definitions when available.
1655 * 'info proc' now works on running processes on FreeBSD systems and core
1656 files created on FreeBSD systems.
1658 * C expressions can now use _Alignof, and C++ expressions can now use
1661 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1662 the vector length while the process is running.
1668 Control display of debugging info regarding the FreeBSD native target.
1670 set|show varsize-limit
1671 This new setting allows the user to control the maximum size of Ada
1672 objects being printed when those objects have a variable type,
1673 instead of that maximum size being hardcoded to 65536 bytes.
1675 set|show record btrace cpu
1676 Controls the processor to be used for enabling errata workarounds for
1677 branch trace decode.
1679 maint check libthread-db
1680 Run integrity checks on the current inferior's thread debugging
1683 maint set check-libthread-db (on|off)
1684 maint show check-libthread-db
1685 Control whether to run integrity checks on inferior specific thread
1686 debugging libraries as they are loaded. The default is not to
1687 perform such checks.
1691 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1693 ** The commands attached to a breakpoint can be set by assigning to
1694 the breakpoint's "commands" field.
1696 ** gdb.execute can now execute multi-line gdb commands.
1698 ** The new functions gdb.convenience_variable and
1699 gdb.set_convenience_variable can be used to get and set the value
1700 of convenience variables.
1702 ** A gdb.Parameter will no longer print the "set" help text on an
1703 ordinary "set"; instead by default a "set" will be silent unless
1704 the get_set_string method returns a non-empty string.
1708 RiscV ELF riscv*-*-elf
1710 * Removed targets and native configurations
1712 m88k running OpenBSD m88*-*-openbsd*
1713 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1714 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1715 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1717 * Aarch64/Linux hardware watchpoints improvements
1719 Hardware watchpoints on unaligned addresses are now properly
1720 supported when running Linux kernel 4.10 or higher: read and access
1721 watchpoints are no longer spuriously missed, and all watchpoints
1722 lengths between 1 and 8 bytes are supported. On older kernels,
1723 watchpoints set on unaligned addresses are no longer missed, with
1724 the tradeoff that there is a possibility of false hits being
1729 --enable-codesign=CERT
1730 This can be used to invoke "codesign -s CERT" after building gdb.
1731 This option is useful on macOS, where code signing is required for
1732 gdb to work properly.
1734 --disable-gdbcli has been removed
1735 This is now silently accepted, but does nothing.
1737 *** Changes in GDB 8.1
1739 * GDB now supports dynamically creating arbitrary register groups specified
1740 in XML target descriptions. This allows for finer grain grouping of
1741 registers on systems with a large amount of registers.
1743 * The 'ptype' command now accepts a '/o' flag, which prints the
1744 offsets and sizes of fields in a struct, like the pahole(1) tool.
1746 * New "--readnever" command line option instructs GDB to not read each
1747 symbol file's symbolic debug information. This makes startup faster
1748 but at the expense of not being able to perform symbolic debugging.
1749 This option is intended for use cases where symbolic debugging will
1750 not be used, e.g., when you only need to dump the debuggee's core.
1752 * GDB now uses the GNU MPFR library, if available, to emulate target
1753 floating-point arithmetic during expression evaluation when the target
1754 uses different floating-point formats than the host. At least version
1755 3.1 of GNU MPFR is required.
1757 * GDB now supports access to the guarded-storage-control registers and the
1758 software-based guarded-storage broadcast control registers on IBM z14.
1760 * On Unix systems, GDB now supports transmitting environment variables
1761 that are to be set or unset to GDBserver. These variables will
1762 affect the environment to be passed to the remote inferior.
1764 To inform GDB of environment variables that are to be transmitted to
1765 GDBserver, use the "set environment" command. Only user set
1766 environment variables are sent to GDBserver.
1768 To inform GDB of environment variables that are to be unset before
1769 the remote inferior is started by the GDBserver, use the "unset
1770 environment" command.
1772 * Completion improvements
1774 ** GDB can now complete function parameters in linespecs and
1775 explicit locations without quoting. When setting breakpoints,
1776 quoting around functions names to help with TAB-completion is
1777 generally no longer necessary. For example, this now completes
1780 (gdb) b function(in[TAB]
1781 (gdb) b function(int)
1783 Related, GDB is no longer confused with completing functions in
1784 C++ anonymous namespaces:
1787 (gdb) b (anonymous namespace)::[TAB][TAB]
1788 (anonymous namespace)::a_function()
1789 (anonymous namespace)::b_function()
1791 ** GDB now has much improved linespec and explicit locations TAB
1792 completion support, that better understands what you're
1793 completing and offers better suggestions. For example, GDB no
1794 longer offers data symbols as possible completions when you're
1795 setting a breakpoint.
1797 ** GDB now TAB-completes label symbol names.
1799 ** The "complete" command now mimics TAB completion accurately.
1801 * New command line options (gcore)
1804 Dump all memory mappings.
1806 * Breakpoints on C++ functions are now set on all scopes by default
1808 By default, breakpoints on functions/methods are now interpreted as
1809 specifying all functions with the given name ignoring missing
1810 leading scopes (namespaces and classes).
1812 For example, assuming a C++ program with symbols named:
1817 both commands "break func()" and "break B::func()" set a breakpoint
1820 You can use the new flag "-qualified" to override this. This makes
1821 GDB interpret the specified function name as a complete
1822 fully-qualified name instead. For example, using the same C++
1823 program, the "break -q B::func" command sets a breakpoint on
1824 "B::func", only. A parameter has been added to the Python
1825 gdb.Breakpoint constructor to achieve the same result when creating
1826 a breakpoint from Python.
1828 * Breakpoints on functions marked with C++ ABI tags
1830 GDB can now set breakpoints on functions marked with C++ ABI tags
1831 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1832 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1834 Functions with a C++11 abi tag are demangled/displayed like this:
1836 function[abi:cxx11](int)
1839 You can now set a breakpoint on such functions simply as if they had
1842 (gdb) b function(int)
1844 Or if you need to disambiguate between tags, like:
1846 (gdb) b function[abi:other_tag](int)
1848 Tab completion was adjusted accordingly as well.
1852 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1853 gdb.new_thread are emitted. See the manual for further
1854 description of these.
1856 ** A new function, "gdb.rbreak" has been added to the Python API.
1857 This function allows the setting of a large number of breakpoints
1858 via a regex pattern in Python. See the manual for further details.
1860 ** Python breakpoints can now accept explicit locations. See the
1861 manual for a further description of this feature.
1864 * New features in the GDB remote stub, GDBserver
1866 ** GDBserver is now able to start inferior processes with a
1867 specified initial working directory.
1869 The user can set the desired working directory to be used from
1870 GDB using the new "set cwd" command.
1872 ** New "--selftest" command line option runs some GDBserver self
1873 tests. These self tests are disabled in releases.
1875 ** On Unix systems, GDBserver now does globbing expansion and variable
1876 substitution in inferior command line arguments.
1878 This is done by starting inferiors using a shell, like GDB does.
1879 See "set startup-with-shell" in the user manual for how to disable
1880 this from GDB when using "target extended-remote". When using
1881 "target remote", you can disable the startup with shell by using the
1882 new "--no-startup-with-shell" GDBserver command line option.
1884 ** On Unix systems, GDBserver now supports receiving environment
1885 variables that are to be set or unset from GDB. These variables
1886 will affect the environment to be passed to the inferior.
1888 * When catching an Ada exception raised with a message, GDB now prints
1889 the message in the catchpoint hit notification. In GDB/MI mode, that
1890 information is provided as an extra field named "exception-message"
1891 in the *stopped notification.
1893 * Trait objects can now be inspected When debugging Rust code. This
1894 requires compiler support which will appear in Rust 1.24.
1896 * New remote packets
1898 QEnvironmentHexEncoded
1899 Inform GDBserver of an environment variable that is to be passed to
1900 the inferior when starting it.
1903 Inform GDBserver of an environment variable that is to be unset
1904 before starting the remote inferior.
1907 Inform GDBserver that the environment should be reset (i.e.,
1908 user-set environment variables should be unset).
1911 Indicates whether the inferior must be started with a shell or not.
1914 Tell GDBserver that the inferior to be started should use a specific
1917 * The "maintenance print c-tdesc" command now takes an optional
1918 argument which is the file name of XML target description.
1920 * The "maintenance selftest" command now takes an optional argument to
1921 filter the tests to be run.
1923 * The "enable", and "disable" commands now accept a range of
1924 breakpoint locations, e.g. "enable 1.3-5".
1929 Set and show the current working directory for the inferior.
1931 set|show compile-gcc
1932 Set and show compilation command used for compiling and injecting code
1933 with the 'compile' commands.
1935 set debug separate-debug-file
1936 show debug separate-debug-file
1937 Control the display of debug output about separate debug file search.
1939 set dump-excluded-mappings
1940 show dump-excluded-mappings
1941 Control whether mappings marked with the VM_DONTDUMP flag should be
1942 dumped when generating a core file.
1944 maint info selftests
1945 List the registered selftests.
1948 Start the debugged program stopping at the first instruction.
1951 Control display of debugging messages related to OpenRISC targets.
1953 set|show print type nested-type-limit
1954 Set and show the limit of nesting level for nested types that the
1955 type printer will show.
1957 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1960 * Safer/improved support for debugging with no debug info
1962 GDB no longer assumes functions with no debug information return
1965 This means that GDB now refuses to call such functions unless you
1966 tell it the function's type, by either casting the call to the
1967 declared return type, or by casting the function to a function
1968 pointer of the right type, and calling that:
1970 (gdb) p getenv ("PATH")
1971 'getenv' has unknown return type; cast the call to its declared return type
1972 (gdb) p (char *) getenv ("PATH")
1973 $1 = 0x7fffffffe "/usr/local/bin:/"...
1974 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1975 $2 = 0x7fffffffe "/usr/local/bin:/"...
1977 Similarly, GDB no longer assumes that global variables with no debug
1978 info have type 'int', and refuses to print the variable's value
1979 unless you tell it the variable's type:
1982 'var' has unknown type; cast it to its declared type
1986 * New native configurations
1988 FreeBSD/aarch64 aarch64*-*-freebsd*
1989 FreeBSD/arm arm*-*-freebsd*
1993 FreeBSD/aarch64 aarch64*-*-freebsd*
1994 FreeBSD/arm arm*-*-freebsd*
1995 OpenRISC ELF or1k*-*-elf
1997 * Removed targets and native configurations
1999 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2001 *** Changes in GDB 8.0
2003 * GDB now supports access to the PKU register on GNU/Linux. The register is
2004 added by the Memory Protection Keys for Userspace feature which will be
2005 available in future Intel CPUs.
2007 * GDB now supports C++11 rvalue references.
2011 ** New functions to start, stop and access a running btrace recording.
2012 ** Rvalue references are now supported in gdb.Type.
2014 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2017 * Building GDB and GDBserver now requires a C++11 compiler.
2019 For example, GCC 4.8 or later.
2021 It is no longer possible to build GDB or GDBserver with a C
2022 compiler. The --disable-build-with-cxx configure option has been
2025 * Building GDB and GDBserver now requires GNU make >= 3.81.
2027 It is no longer supported to build GDB or GDBserver with another
2028 implementation of the make program or an earlier version of GNU make.
2030 * Native debugging on MS-Windows supports command-line redirection
2032 Command-line arguments used for starting programs on MS-Windows can
2033 now include redirection symbols supported by native Windows shells,
2034 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2035 as "run", "start", and "set args", as well as the corresponding MI
2038 * Support for thread names on MS-Windows.
2040 GDB now catches and handles the special exception that programs
2041 running on MS-Windows use to assign names to threads in the
2044 * Support for Java programs compiled with gcj has been removed.
2046 * User commands now accept an unlimited number of arguments.
2047 Previously, only up to 10 was accepted.
2049 * The "eval" command now expands user-defined command arguments.
2051 This makes it easier to process a variable number of arguments:
2056 eval "print $arg%d", $i
2061 * Target descriptions can now describe registers for sparc32 and sparc64.
2063 * GDB now supports DWARF version 5 (debug information format).
2064 Its .debug_names index is not yet supported.
2066 * New native configurations
2068 FreeBSD/mips mips*-*-freebsd
2072 Synopsys ARC arc*-*-elf32
2073 FreeBSD/mips mips*-*-freebsd
2075 * Removed targets and native configurations
2077 Alpha running FreeBSD alpha*-*-freebsd*
2078 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2083 Erases all the flash memory regions reported by the target.
2085 maint print arc arc-instruction address
2086 Print internal disassembler information about instruction at a given address.
2090 set disassembler-options
2091 show disassembler-options
2092 Controls the passing of target specific information to the disassembler.
2093 If it is necessary to specify more than one disassembler option then
2094 multiple options can be placed together into a comma separated list.
2095 The default value is the empty string. Currently, the only supported
2096 targets are ARM, PowerPC and S/390.
2101 Erases all the flash memory regions reported by the target. This is
2102 equivalent to the CLI command flash-erase.
2104 -file-list-shared-libraries
2105 List the shared libraries in the program. This is
2106 equivalent to the CLI command "info shared".
2109 Catchpoints stopping the program when Ada exceptions are
2110 handled. This is equivalent to the CLI command "catch handlers".
2112 *** Changes in GDB 7.12
2114 * GDB and GDBserver now build with a C++ compiler by default.
2116 The --enable-build-with-cxx configure option is now enabled by
2117 default. One must now explicitly configure with
2118 --disable-build-with-cxx in order to build with a C compiler. This
2119 option will be removed in a future release.
2121 * GDBserver now supports recording btrace without maintaining an active
2124 * GDB now supports a negative repeat count in the 'x' command to examine
2125 memory backward from the given address. For example:
2128 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2129 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2130 (gdb) x/-5i 0x0000000000400580
2131 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2132 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2133 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2134 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2135 0x40057b <main(int, char**)+25>:
2136 callq 0x400536 <Func1(int, char const*)>
2138 * Fortran: Support structures with fields of dynamic types and
2139 arrays of dynamic types.
2141 * The symbol dumping maintenance commands have new syntax.
2142 maint print symbols [-pc address] [--] [filename]
2143 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2144 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2145 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2146 maint print msymbols [-objfile objfile] [--] [filename]
2148 * GDB now supports multibit bitfields and enums in target register
2151 * New Python-based convenience function $_as_string(val), which returns
2152 the textual representation of a value. This function is especially
2153 useful to obtain the text label of an enum value.
2155 * Intel MPX bound violation handling.
2157 Segmentation faults caused by a Intel MPX boundary violation
2158 now display the kind of violation (upper or lower), the memory
2159 address accessed and the memory bounds, along with the usual
2160 signal received and code location.
2164 Program received signal SIGSEGV, Segmentation fault
2165 Upper bound violation while accessing address 0x7fffffffc3b3
2166 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2167 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2169 * Rust language support.
2170 GDB now supports debugging programs written in the Rust programming
2171 language. See https://www.rust-lang.org/ for more information about
2174 * Support for running interpreters on specified input/output devices
2176 GDB now supports a new mechanism that allows frontends to provide
2177 fully featured GDB console views, as a better alternative to
2178 building such views on top of the "-interpreter-exec console"
2179 command. See the new "new-ui" command below. With that command,
2180 frontends can now start GDB in the traditional command-line mode
2181 running in an embedded terminal emulator widget, and create a
2182 separate MI interpreter running on a specified i/o device. In this
2183 way, GDB handles line editing, history, tab completion, etc. in the
2184 console all by itself, and the GUI uses the separate MI interpreter
2185 for its own control and synchronization, invisible to the command
2188 * The "catch syscall" command catches groups of related syscalls.
2190 The "catch syscall" command now supports catching a group of related
2191 syscalls using the 'group:' or 'g:' prefix.
2196 skip -gfile file-glob-pattern
2197 skip -function function
2198 skip -rfunction regular-expression
2199 A generalized form of the skip command, with new support for
2200 glob-style file names and regular expressions for function names.
2201 Additionally, a file spec and a function spec may now be combined.
2203 maint info line-table REGEXP
2204 Display the contents of GDB's internal line table data structure.
2207 Run any GDB unit tests that were compiled in.
2210 Start a new user interface instance running INTERP as interpreter,
2211 using the TTY file for input/output.
2215 ** gdb.Breakpoint objects have a new attribute "pending", which
2216 indicates whether the breakpoint is pending.
2217 ** Three new breakpoint-related events have been added:
2218 gdb.breakpoint_created, gdb.breakpoint_modified, and
2219 gdb.breakpoint_deleted.
2221 signal-event EVENTID
2222 Signal ("set") the given MS-Windows event object. This is used in
2223 conjunction with the Windows JIT debugging (AeDebug) support, where
2224 the OS suspends a crashing process until a debugger can attach to
2225 it. Resuming the crashing process, in order to debug it, is done by
2226 signalling an event.
2228 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2229 was added in GDBserver, including JIT compiling fast tracepoint's
2230 conditional expression bytecode into native code.
2232 * Support for various remote target protocols and ROM monitors has
2235 target m32rsdi Remote M32R debugging over SDI
2236 target mips MIPS remote debugging protocol
2237 target pmon PMON ROM monitor
2238 target ddb NEC's DDB variant of PMON for Vr4300
2239 target rockhopper NEC RockHopper variant of PMON
2240 target lsi LSI variant of PMO
2242 * Support for tracepoints and fast tracepoints on powerpc-linux,
2243 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2244 including JIT compiling fast tracepoint's conditional expression
2245 bytecode into native code.
2247 * MI async record =record-started now includes the method and format used for
2248 recording. For example:
2250 =record-started,thread-group="i1",method="btrace",format="bts"
2252 * MI async record =thread-selected now includes the frame field. For example:
2254 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2258 Andes NDS32 nds32*-*-elf
2260 *** Changes in GDB 7.11
2262 * GDB now supports debugging kernel-based threads on FreeBSD.
2264 * Per-inferior thread numbers
2266 Thread numbers are now per inferior instead of global. If you're
2267 debugging multiple inferiors, GDB displays thread IDs using a
2268 qualified INF_NUM.THR_NUM form. For example:
2272 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2273 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2274 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2275 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2277 As consequence, thread numbers as visible in the $_thread
2278 convenience variable and in Python's InferiorThread.num attribute
2279 are no longer unique between inferiors.
2281 GDB now maintains a second thread ID per thread, referred to as the
2282 global thread ID, which is the new equivalent of thread numbers in
2283 previous releases. See also $_gthread below.
2285 For backwards compatibility, MI's thread IDs always refer to global
2288 * Commands that accept thread IDs now accept the qualified
2289 INF_NUM.THR_NUM form as well. For example:
2292 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2295 * In commands that accept a list of thread IDs, you can now refer to
2296 all threads of an inferior using a star wildcard. GDB accepts
2297 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2298 refer to all threads of the current inferior. For example, "info
2301 * You can use "info threads -gid" to display the global thread ID of
2304 * The new convenience variable $_gthread holds the global number of
2307 * The new convenience variable $_inferior holds the number of the
2310 * GDB now displays the ID and name of the thread that hit a breakpoint
2311 or received a signal, if your program is multi-threaded. For
2314 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2315 Thread 1 "main" received signal SIGINT, Interrupt.
2317 * Record btrace now supports non-stop mode.
2319 * Support for tracepoints on aarch64-linux was added in GDBserver.
2321 * The 'record instruction-history' command now indicates speculative execution
2322 when using the Intel Processor Trace recording format.
2324 * GDB now allows users to specify explicit locations, bypassing
2325 the linespec parser. This feature is also available to GDB/MI
2328 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2329 GDB now is able to debug both AArch64 applications and ARM applications
2332 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2333 including JIT compiling fast tracepoint's conditional expression bytecode
2336 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2338 * "info threads", "info inferiors", "info display", "info checkpoints"
2339 and "maint info program-spaces" now list the corresponding items in
2340 ascending ID order, for consistency with all other "info" commands.
2342 * In Ada, the overloads selection menu has been enhanced to display the
2343 parameter types and the return types for the matching overloaded subprograms.
2347 maint set target-non-stop (on|off|auto)
2348 maint show target-non-stop
2349 Control whether GDB targets always operate in non-stop mode even if
2350 "set non-stop" is "off". The default is "auto", meaning non-stop
2351 mode is enabled if supported by the target.
2353 maint set bfd-sharing
2354 maint show bfd-sharing
2355 Control the reuse of bfd objects.
2358 show debug bfd-cache
2359 Control display of debugging info regarding bfd caching.
2363 Control display of debugging info regarding FreeBSD threads.
2365 set remote multiprocess-extensions-packet
2366 show remote multiprocess-extensions-packet
2367 Set/show the use of the remote protocol multiprocess extensions.
2369 set remote thread-events
2370 show remote thread-events
2371 Set/show the use of thread create/exit events.
2373 set ada print-signatures on|off
2374 show ada print-signatures"
2375 Control whether parameter types and return types are displayed in overloads
2376 selection menus. It is activated (@code{on}) by default.
2380 Controls the maximum size of memory, in bytes, that GDB will
2381 allocate for value contents. Prevents incorrect programs from
2382 causing GDB to allocate overly large buffers. Default is 64k.
2384 * The "disassemble" command accepts a new modifier: /s.
2385 It prints mixed source+disassembly like /m with two differences:
2386 - disassembled instructions are now printed in program order, and
2387 - and source for all relevant files is now printed.
2388 The "/m" option is now considered deprecated: its "source-centric"
2389 output hasn't proved useful in practice.
2391 * The "record instruction-history" command accepts a new modifier: /s.
2392 It behaves exactly like /m and prints mixed source+disassembly.
2394 * The "set scheduler-locking" command supports a new mode "replay".
2395 It behaves like "off" in record mode and like "on" in replay mode.
2397 * Support for various ROM monitors has been removed:
2399 target dbug dBUG ROM monitor for Motorola ColdFire
2400 target picobug Motorola picobug monitor
2401 target dink32 DINK32 ROM monitor for PowerPC
2402 target m32r Renesas M32R/D ROM monitor
2403 target mon2000 mon2000 ROM monitor
2404 target ppcbug PPCBUG ROM monitor for PowerPC
2406 * Support for reading/writing memory and extracting values on architectures
2407 whose memory is addressable in units of any integral multiple of 8 bits.
2410 Allows to break when an Ada exception is handled.
2412 * New remote packets
2415 Indicates that an exec system call was executed.
2417 exec-events feature in qSupported
2418 The qSupported packet allows GDB to request support for exec
2419 events using the new 'gdbfeature' exec-event, and the qSupported
2420 response can contain the corresponding 'stubfeature'. Set and
2421 show commands can be used to display whether these features are enabled.
2424 Equivalent to interrupting with the ^C character, but works in
2427 thread created stop reason (T05 create:...)
2428 Indicates that the thread was just created and is stopped at entry.
2430 thread exit stop reply (w exitcode;tid)
2431 Indicates that the thread has terminated.
2434 Enables/disables thread create and exit event reporting. For
2435 example, this is used in non-stop mode when GDB stops a set of
2436 threads and synchronously waits for the their corresponding stop
2437 replies. Without exit events, if one of the threads exits, GDB
2438 would hang forever not knowing that it should no longer expect a
2439 stop for that same thread.
2442 Indicates that there are no resumed threads left in the target (all
2443 threads are stopped). The remote stub reports support for this stop
2444 reply to GDB's qSupported query.
2447 Enables/disables catching syscalls from the inferior process.
2448 The remote stub reports support for this packet to GDB's qSupported query.
2450 syscall_entry stop reason
2451 Indicates that a syscall was just called.
2453 syscall_return stop reason
2454 Indicates that a syscall just returned.
2456 * Extended-remote exec events
2458 ** GDB now has support for exec events on extended-remote Linux targets.
2459 For such targets with Linux kernels 2.5.46 and later, this enables
2460 follow-exec-mode and exec catchpoints.
2462 set remote exec-event-feature-packet
2463 show remote exec-event-feature-packet
2464 Set/show the use of the remote exec event feature.
2466 * Thread names in remote protocol
2468 The reply to qXfer:threads:read may now include a name attribute for each
2471 * Target remote mode fork and exec events
2473 ** GDB now has support for fork and exec events on target remote mode
2474 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2475 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2476 fork and exec catchpoints.
2478 * Remote syscall events
2480 ** GDB now has support for catch syscall on remote Linux targets,
2481 currently enabled on x86/x86_64 architectures.
2483 set remote catch-syscall-packet
2484 show remote catch-syscall-packet
2485 Set/show the use of the remote catch syscall feature.
2489 ** The -var-set-format command now accepts the zero-hexadecimal
2490 format. It outputs data in hexadecimal format with zero-padding on the
2495 ** gdb.InferiorThread objects have a new attribute "global_num",
2496 which refers to the thread's global thread ID. The existing
2497 "num" attribute now refers to the thread's per-inferior number.
2498 See "Per-inferior thread numbers" above.
2499 ** gdb.InferiorThread objects have a new attribute "inferior", which
2500 is the Inferior object the thread belongs to.
2502 *** Changes in GDB 7.10
2504 * Support for process record-replay and reverse debugging on aarch64*-linux*
2505 targets has been added. GDB now supports recording of A64 instruction set
2506 including advance SIMD instructions.
2508 * Support for Sun's version of the "stabs" debug file format has been removed.
2510 * GDB now honors the content of the file /proc/PID/coredump_filter
2511 (PID is the process ID) on GNU/Linux systems. This file can be used
2512 to specify the types of memory mappings that will be included in a
2513 corefile. For more information, please refer to the manual page of
2514 "core(5)". GDB also has a new command: "set use-coredump-filter
2515 on|off". It allows to set whether GDB will read the content of the
2516 /proc/PID/coredump_filter file when generating a corefile.
2518 * The "info os" command on GNU/Linux can now display information on
2520 "info os cpus" Listing of all cpus/cores on the system
2522 * GDB has two new commands: "set serial parity odd|even|none" and
2523 "show serial parity". These allows to set or show parity for the
2526 * The "info source" command now displays the producer string if it was
2527 present in the debug info. This typically includes the compiler version
2528 and may include things like its command line arguments.
2530 * The "info dll", an alias of the "info sharedlibrary" command,
2531 is now available on all platforms.
2533 * Directory names supplied to the "set sysroot" commands may be
2534 prefixed with "target:" to tell GDB to access shared libraries from
2535 the target system, be it local or remote. This replaces the prefix
2536 "remote:". The default sysroot has been changed from "" to
2537 "target:". "remote:" is automatically converted to "target:" for
2538 backward compatibility.
2540 * The system root specified by "set sysroot" will be prepended to the
2541 filename of the main executable (if reported to GDB as absolute by
2542 the operating system) when starting processes remotely, and when
2543 attaching to already-running local or remote processes.
2545 * GDB now supports automatic location and retrieval of executable
2546 files from remote targets. Remote debugging can now be initiated
2547 using only a "target remote" or "target extended-remote" command
2548 (no "set sysroot" or "file" commands are required). See "New remote
2551 * The "dump" command now supports verilog hex format.
2553 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2555 * On GNU/Linux, GDB and gdbserver are now able to access executable
2556 and shared library files without a "set sysroot" command when
2557 attaching to processes running in different mount namespaces from
2558 the debugger. This makes it possible to attach to processes in
2559 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2560 See "New remote packets" below.
2562 * The "tui reg" command now provides completion for all of the
2563 available register groups, including target specific groups.
2565 * The HISTSIZE environment variable is no longer read when determining
2566 the size of GDB's command history. GDB now instead reads the dedicated
2567 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2568 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2573 ** Memory ports can now be unbuffered.
2577 ** gdb.Objfile objects have a new attribute "username",
2578 which is the name of the objfile as specified by the user,
2579 without, for example, resolving symlinks.
2580 ** You can now write frame unwinders in Python.
2581 ** gdb.Type objects have a new method "optimized_out",
2582 returning optimized out gdb.Value instance of this type.
2583 ** gdb.Value objects have new methods "reference_value" and
2584 "const_value" which return a reference to the value and a
2585 "const" version of the value respectively.
2589 maint print symbol-cache
2590 Print the contents of the symbol cache.
2592 maint print symbol-cache-statistics
2593 Print statistics of symbol cache usage.
2595 maint flush-symbol-cache
2596 Flush the contents of the symbol cache.
2600 Start branch trace recording using Branch Trace Store (BTS) format.
2603 Evaluate expression by using the compiler and print result.
2607 Explicit commands for enabling and disabling tui mode.
2610 set mpx bound on i386 and amd64
2611 Support for bound table investigation on Intel MPX enabled applications.
2615 Start branch trace recording using Intel Processor Trace format.
2618 Print information about branch tracing internals.
2620 maint btrace packet-history
2621 Print the raw branch tracing data.
2623 maint btrace clear-packet-history
2624 Discard the stored raw branch tracing data.
2627 Discard all branch tracing data. It will be fetched and processed
2628 anew by the next "record" command.
2633 Renamed from "set debug dwarf2-die".
2634 show debug dwarf-die
2635 Renamed from "show debug dwarf2-die".
2637 set debug dwarf-read
2638 Renamed from "set debug dwarf2-read".
2639 show debug dwarf-read
2640 Renamed from "show debug dwarf2-read".
2642 maint set dwarf always-disassemble
2643 Renamed from "maint set dwarf2 always-disassemble".
2644 maint show dwarf always-disassemble
2645 Renamed from "maint show dwarf2 always-disassemble".
2647 maint set dwarf max-cache-age
2648 Renamed from "maint set dwarf2 max-cache-age".
2649 maint show dwarf max-cache-age
2650 Renamed from "maint show dwarf2 max-cache-age".
2652 set debug dwarf-line
2653 show debug dwarf-line
2654 Control display of debugging info regarding DWARF line processing.
2657 show max-completions
2658 Set the maximum number of candidates to be considered during
2659 completion. The default value is 200. This limit allows GDB
2660 to avoid generating large completion lists, the computation of
2661 which can cause the debugger to become temporarily unresponsive.
2663 set history remove-duplicates
2664 show history remove-duplicates
2665 Control the removal of duplicate history entries.
2667 maint set symbol-cache-size
2668 maint show symbol-cache-size
2669 Control the size of the symbol cache.
2671 set|show record btrace bts buffer-size
2672 Set and show the size of the ring buffer used for branch tracing in
2674 The obtained size may differ from the requested size. Use "info
2675 record" to see the obtained buffer size.
2677 set debug linux-namespaces
2678 show debug linux-namespaces
2679 Control display of debugging info regarding Linux namespaces.
2681 set|show record btrace pt buffer-size
2682 Set and show the size of the ring buffer used for branch tracing in
2683 Intel Processor Trace format.
2684 The obtained size may differ from the requested size. Use "info
2685 record" to see the obtained buffer size.
2687 maint set|show btrace pt skip-pad
2688 Set and show whether PAD packets are skipped when computing the
2691 * The command 'thread apply all' can now support new option '-ascending'
2692 to call its specified command for all threads in ascending order.
2694 * Python/Guile scripting
2696 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2697 special section named `.debug_gdb_scripts'.
2699 * New remote packets
2701 qXfer:btrace-conf:read
2702 Return the branch trace configuration for the current thread.
2704 Qbtrace-conf:bts:size
2705 Set the requested ring buffer size for branch tracing in BTS format.
2708 Enable Intel Processor Trace-based branch tracing for the current
2709 process. The remote stub reports support for this packet to GDB's
2712 Qbtrace-conf:pt:size
2713 Set the requested ring buffer size for branch tracing in Intel Processor
2717 Indicates a memory breakpoint instruction was executed, irrespective
2718 of whether it was GDB that planted the breakpoint or the breakpoint
2719 is hardcoded in the program. This is required for correct non-stop
2723 Indicates the target stopped for a hardware breakpoint. This is
2724 required for correct non-stop mode operation.
2727 Return information about files on the remote system.
2729 qXfer:exec-file:read
2730 Return the full absolute name of the file that was executed to
2731 create a process running on the remote system.
2734 Select the filesystem on which vFile: operations with filename
2735 arguments will operate. This is required for GDB to be able to
2736 access files on remote targets where the remote stub does not
2737 share a common filesystem with the inferior(s).
2740 Indicates that a fork system call was executed.
2743 Indicates that a vfork system call was executed.
2745 vforkdone stop reason
2746 Indicates that a vfork child of the specified process has executed
2747 an exec or exit, allowing the vfork parent to resume execution.
2749 fork-events and vfork-events features in qSupported
2750 The qSupported packet allows GDB to request support for fork and
2751 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2752 and the qSupported response can contain the corresponding
2753 'stubfeatures'. Set and show commands can be used to display
2754 whether these features are enabled.
2756 * Extended-remote fork events
2758 ** GDB now has support for fork events on extended-remote Linux
2759 targets. For targets with Linux kernels 2.5.60 and later, this
2760 enables follow-fork-mode and detach-on-fork for both fork and
2761 vfork, as well as fork and vfork catchpoints.
2763 * The info record command now shows the recording format and the
2764 branch tracing configuration for the current thread when using
2765 the btrace record target.
2766 For the BTS format, it shows the ring buffer size.
2768 * GDB now has support for DTrace USDT (Userland Static Defined
2769 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2771 * GDB now supports access to vector registers on S/390 GNU/Linux
2774 * Removed command line options
2776 -xdb HP-UX XDB compatibility mode.
2778 * Removed targets and native configurations
2780 HP/PA running HP-UX hppa*-*-hpux*
2781 Itanium running HP-UX ia64-*-hpux*
2783 * New configure options
2786 This configure option allows the user to build GDB with support for
2787 Intel Processor Trace (default: auto). This requires libipt.
2789 --with-libipt-prefix=PATH
2790 Specify the path to the version of libipt that GDB should use.
2791 $PATH/include should contain the intel-pt.h header and
2792 $PATH/lib should contain the libipt.so library.
2794 *** Changes in GDB 7.9.1
2798 ** Xmethods can now specify a result type.
2800 *** Changes in GDB 7.9
2802 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2806 ** You can now access frame registers from Python scripts.
2807 ** New attribute 'producer' for gdb.Symtab objects.
2808 ** gdb.Objfile objects have a new attribute "progspace",
2809 which is the gdb.Progspace object of the containing program space.
2810 ** gdb.Objfile objects have a new attribute "owner".
2811 ** gdb.Objfile objects have a new attribute "build_id",
2812 which is the build ID generated when the file was built.
2813 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2814 ** A new event "gdb.clear_objfiles" has been added, triggered when
2815 selecting a new file to debug.
2816 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2817 ** New function gdb.lookup_objfile.
2819 New events which are triggered when GDB modifies the state of the
2822 ** gdb.events.inferior_call_pre: Function call is about to be made.
2823 ** gdb.events.inferior_call_post: Function call has just been made.
2824 ** gdb.events.memory_changed: A memory location has been altered.
2825 ** gdb.events.register_changed: A register has been altered.
2827 * New Python-based convenience functions:
2829 ** $_caller_is(name [, number_of_frames])
2830 ** $_caller_matches(regexp [, number_of_frames])
2831 ** $_any_caller_is(name [, number_of_frames])
2832 ** $_any_caller_matches(regexp [, number_of_frames])
2834 * GDB now supports the compilation and injection of source code into
2835 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2836 to compile the source code to object code, and if successful, inject
2837 and execute that code within the current context of the inferior.
2838 Currently the C language is supported. The commands used to
2839 interface with this new feature are:
2841 compile code [-raw|-r] [--] [source code]
2842 compile file [-raw|-r] filename
2846 demangle [-l language] [--] name
2847 Demangle "name" in the specified language, or the current language
2848 if elided. This command is renamed from the "maint demangle" command.
2849 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2850 as "maint demangler-warning".
2852 queue-signal signal-name-or-number
2853 Queue a signal to be delivered to the thread when it is resumed.
2855 add-auto-load-scripts-directory directory
2856 Add entries to the list of directories from which to load auto-loaded
2859 maint print user-registers
2860 List all currently available "user" registers.
2862 compile code [-r|-raw] [--] [source code]
2863 Compile, inject, and execute in the inferior the executable object
2864 code produced by compiling the provided source code.
2866 compile file [-r|-raw] filename
2867 Compile and inject into the inferior the executable object code
2868 produced by compiling the source code stored in the filename
2871 * On resume, GDB now always passes the signal the program had stopped
2872 for to the thread the signal was sent to, even if the user changed
2873 threads before resuming. Previously GDB would often (but not
2874 always) deliver the signal to the thread that happens to be current
2877 * Conversely, the "signal" command now consistently delivers the
2878 requested signal to the current thread. GDB now asks for
2879 confirmation if the program had stopped for a signal and the user
2880 switched threads meanwhile.
2882 * "breakpoint always-inserted" modes "off" and "auto" merged.
2884 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2885 won't remove breakpoints from the target until all threads stop,
2886 even in non-stop mode. The "auto" mode has been removed, and "off"
2887 is now the default mode.
2891 set debug symbol-lookup
2892 show debug symbol-lookup
2893 Control display of debugging info regarding symbol lookup.
2897 ** The -list-thread-groups command outputs an exit-code field for
2898 inferiors that have exited.
2902 MIPS SDE mips*-sde*-elf*
2906 Support for these obsolete configurations has been removed.
2908 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2909 SGI Irix-5.x mips-*-irix5*
2910 SGI Irix-6.x mips-*-irix6*
2911 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2912 VAX running Ultrix vax-*-ultrix*
2914 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2915 and "assf"), have been removed. Use the "sharedlibrary" command, or
2916 its alias "share", instead.
2918 *** Changes in GDB 7.8
2920 * New command line options
2923 This is an alias for the --data-directory option.
2925 * GDB supports printing and modifying of variable length automatic arrays
2926 as specified in ISO C99.
2928 * The ARM simulator now supports instruction level tracing
2929 with or without disassembly.
2933 GDB now has support for scripting using Guile. Whether this is
2934 available is determined at configure time.
2935 Guile version 2.0 or greater is required.
2936 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2938 * New commands (for set/show, see "New options" below)
2942 Invoke CODE by passing it to the Guile interpreter.
2946 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2948 info auto-load guile-scripts [regexp]
2949 Print the list of automatically loaded Guile scripts.
2951 * The source command is now capable of sourcing Guile scripts.
2952 This feature is dependent on the debugger being built with Guile support.
2956 set print symbol-loading (off|brief|full)
2957 show print symbol-loading
2958 Control whether to print informational messages when loading symbol
2959 information for a file. The default is "full", but when debugging
2960 programs with large numbers of shared libraries the amount of output
2961 becomes less useful.
2963 set guile print-stack (none|message|full)
2964 show guile print-stack
2965 Show a stack trace when an error is encountered in a Guile script.
2967 set auto-load guile-scripts (on|off)
2968 show auto-load guile-scripts
2969 Control auto-loading of Guile script files.
2971 maint ada set ignore-descriptive-types (on|off)
2972 maint ada show ignore-descriptive-types
2973 Control whether the debugger should ignore descriptive types in Ada
2974 programs. The default is not to ignore the descriptive types. See
2975 the user manual for more details on descriptive types and the intended
2976 usage of this option.
2978 set auto-connect-native-target
2980 Control whether GDB is allowed to automatically connect to the
2981 native target for the run, attach, etc. commands when not connected
2982 to any target yet. See also "target native" below.
2984 set record btrace replay-memory-access (read-only|read-write)
2985 show record btrace replay-memory-access
2986 Control what memory accesses are allowed during replay.
2988 maint set target-async (on|off)
2989 maint show target-async
2990 This controls whether GDB targets operate in synchronous or
2991 asynchronous mode. Normally the default is asynchronous, if it is
2992 available; but this can be changed to more easily debug problems
2993 occurring only in synchronous mode.
2995 set mi-async (on|off)
2997 Control whether MI asynchronous mode is preferred. This supersedes
2998 "set target-async" of previous GDB versions.
3000 * "set target-async" is deprecated as a CLI option and is now an alias
3001 for "set mi-async" (only puts MI into async mode).
3003 * Background execution commands (e.g., "c&", "s&", etc.) are now
3004 possible ``out of the box'' if the target supports them. Previously
3005 the user would need to explicitly enable the possibility with the
3006 "set target-async on" command.
3008 * New features in the GDB remote stub, GDBserver
3010 ** New option --debug-format=option1[,option2,...] allows one to add
3011 additional text to each output. At present only timestamps
3012 are supported: --debug-format=timestamps.
3013 Timestamps can also be turned on with the
3014 "monitor set debug-format timestamps" command from GDB.
3016 * The 'record instruction-history' command now starts counting instructions
3017 at one. This also affects the instruction ranges reported by the
3018 'record function-call-history' command when given the /i modifier.
3020 * The command 'record function-call-history' supports a new modifier '/c' to
3021 indent the function names based on their call stack depth.
3022 The fields for the '/i' and '/l' modifier have been reordered.
3023 The source line range is now prefixed with 'at'.
3024 The instruction range is now prefixed with 'inst'.
3025 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3026 "record instruction-history" and "list" commands.
3028 * The ranges given as arguments to the 'record function-call-history' and
3029 'record instruction-history' commands are now inclusive.
3031 * The btrace record target now supports the 'record goto' command.
3032 For locations inside the execution trace, the back trace is computed
3033 based on the information stored in the execution trace.
3035 * The btrace record target supports limited reverse execution and replay.
3036 The target does not record data and therefore does not allow reading
3037 memory or registers.
3039 * The "catch syscall" command now works on s390*-linux* targets.
3041 * The "compare-sections" command is no longer specific to target
3042 remote. It now works with all targets.
3044 * All native targets are now consistently called "native".
3045 Consequently, the "target child", "target GNU", "target djgpp",
3046 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3047 commands have been replaced with "target native". The QNX/NTO port
3048 leaves the "procfs" target in place and adds a "native" target for
3049 consistency with other ports. The impact on users should be minimal
3050 as these commands previously either throwed an error, or were
3051 no-ops. The target's name is visible in the output of the following
3052 commands: "help target", "info target", "info files", "maint print
3055 * The "target native" command now connects to the native target. This
3056 can be used to launch native programs even when "set
3057 auto-connect-native-target" is set to off.
3059 * GDB now supports access to Intel MPX registers on GNU/Linux.
3061 * Support for Intel AVX-512 registers on GNU/Linux.
3062 Support displaying and modifying Intel AVX-512 registers
3063 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3065 * New remote packets
3067 qXfer:btrace:read's annex
3068 The qXfer:btrace:read packet supports a new annex 'delta' to read
3069 branch trace incrementally.
3073 ** Valid Python operations on gdb.Value objects representing
3074 structs/classes invoke the corresponding overloaded operators if
3076 ** New `Xmethods' feature in the Python API. Xmethods are
3077 additional methods or replacements for existing methods of a C++
3078 class. This feature is useful for those cases where a method
3079 defined in C++ source code could be inlined or optimized out by
3080 the compiler, making it unavailable to GDB.
3083 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3085 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3086 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3087 its alias "share", instead.
3089 * The commands "set remotebaud" and "show remotebaud" are no longer
3090 supported. Use "set serial baud" and "show serial baud" (respectively)
3095 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3096 target-async". The latter is left as a deprecated alias of the
3097 former for backward compatibility. If the target supports it,
3098 CLI background execution commands are now always possible by
3099 default, independently of whether the frontend stated a
3100 preference for asynchronous execution with "-gdb-set mi-async".
3101 Previously "-gdb-set target-async off" affected both MI execution
3102 commands and CLI execution commands.
3104 *** Changes in GDB 7.7
3106 * Improved support for process record-replay and reverse debugging on
3107 arm*-linux* targets. Support for thumb32 and syscall instruction
3108 recording has been added.
3110 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3112 * GDB now supports Fission DWP file format version 2.
3113 http://gcc.gnu.org/wiki/DebugFission
3115 * New convenience function "$_isvoid", to check whether an expression
3116 is void. A void expression is an expression where the type of the
3117 result is "void". For example, some convenience variables may be
3118 "void" when evaluated (e.g., "$_exitcode" before the execution of
3119 the program being debugged; or an undefined convenience variable).
3120 Another example, when calling a function whose return type is
3123 * The "maintenance print objfiles" command now takes an optional regexp.
3125 * The "catch syscall" command now works on arm*-linux* targets.
3127 * GDB now consistently shows "<not saved>" when printing values of
3128 registers the debug info indicates have not been saved in the frame
3129 and there's nowhere to retrieve them from
3130 (callee-saved/call-clobbered registers):
3135 (gdb) info registers rax
3138 Before, the former would print "<optimized out>", and the latter
3139 "*value not available*".
3141 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3146 ** Frame filters and frame decorators have been added.
3147 ** Temporary breakpoints are now supported.
3148 ** Line tables representation has been added.
3149 ** New attribute 'parent_type' for gdb.Field objects.
3150 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3151 ** New attribute 'name' for gdb.Type objects.
3155 Nios II ELF nios2*-*-elf
3156 Nios II GNU/Linux nios2*-*-linux
3157 Texas Instruments MSP430 msp430*-*-elf
3159 * Removed native configurations
3161 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3162 been removed. ELF variants of these configurations are kept supported.
3164 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3165 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3166 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3167 i[34567]86-*-openbsd3.[0-3]
3168 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3169 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3170 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3174 Like "catch throw", but catches a re-thrown exception.
3175 maint check-psymtabs
3176 Renamed from old "maint check-symtabs".
3178 Perform consistency checks on symtabs.
3179 maint expand-symtabs
3180 Expand symtabs matching an optional regexp.
3183 Display the details of GDB configure-time options.
3185 maint set|show per-command
3186 maint set|show per-command space
3187 maint set|show per-command time
3188 maint set|show per-command symtab
3189 Enable display of per-command gdb resource usage.
3191 remove-symbol-file FILENAME
3192 remove-symbol-file -a ADDRESS
3193 Remove a symbol file added via add-symbol-file. The file to remove
3194 can be identified by its filename or by an address that lies within
3195 the boundaries of this symbol file in memory.
3198 info exceptions REGEXP
3199 Display the list of Ada exceptions defined in the program being
3200 debugged. If provided, only the exceptions whose names match REGEXP
3205 set debug symfile off|on
3207 Control display of debugging info regarding reading symbol files and
3208 symbol tables within those files
3210 set print raw frame-arguments
3211 show print raw frame-arguments
3212 Set/show whether to print frame arguments in raw mode,
3213 disregarding any defined pretty-printers.
3215 set remote trace-status-packet
3216 show remote trace-status-packet
3217 Set/show the use of remote protocol qTStatus packet.
3221 Control display of debugging messages related to Nios II targets.
3225 Control whether target-assisted range stepping is enabled.
3227 set startup-with-shell
3228 show startup-with-shell
3229 Specifies whether Unix child processes are started via a shell or
3234 Use the target memory cache for accesses to the code segment. This
3235 improves performance of remote debugging (particularly disassembly).
3237 * You can now use a literal value 'unlimited' for options that
3238 interpret 0 or -1 as meaning "unlimited". E.g., "set
3239 trace-buffer-size unlimited" is now an alias for "set
3240 trace-buffer-size -1" and "set height unlimited" is now an alias for
3243 * The "set debug symtab-create" debugging option of GDB has been changed to
3244 accept a verbosity level. 0 means "off", 1 provides basic debugging
3245 output, and values of 2 or greater provides more verbose output.
3247 * New command-line options
3249 Display the details of GDB configure-time options.
3251 * The command 'tsave' can now support new option '-ctf' to save trace
3252 buffer in Common Trace Format.
3254 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3257 * GDB now implements the C++ 'typeid' operator.
3259 * The new convenience variable $_exception holds the exception being
3260 thrown or caught at an exception-related catchpoint.
3262 * The exception-related catchpoints, like "catch throw", now accept a
3263 regular expression which can be used to filter exceptions by type.
3265 * The new convenience variable $_exitsignal is automatically set to
3266 the terminating signal number when the program being debugged dies
3267 due to an uncaught signal.
3271 ** All MI commands now accept an optional "--language" option.
3272 Support for this feature can be verified by using the "-list-features"
3273 command, which should contain "language-option".
3275 ** The new command -info-gdb-mi-command allows the user to determine
3276 whether a GDB/MI command is supported or not.
3278 ** The "^error" result record returned when trying to execute an undefined
3279 GDB/MI command now provides a variable named "code" whose content is the
3280 "undefined-command" error code. Support for this feature can be verified
3281 by using the "-list-features" command, which should contain
3282 "undefined-command-error-code".
3284 ** The -trace-save MI command can optionally save trace buffer in Common
3287 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3289 ** The command -data-list-register-values now accepts an optional
3290 "--skip-unavailable" option. When used, only the available registers
3293 ** The new command -trace-frame-collected dumps collected variables,
3294 computed expressions, tvars, memory and registers in a traceframe.
3296 ** The commands -stack-list-locals, -stack-list-arguments and
3297 -stack-list-variables now accept an option "--skip-unavailable".
3298 When used, only the available locals or arguments are displayed.
3300 ** The -exec-run command now accepts an optional "--start" option.
3301 When used, the command follows the same semantics as the "start"
3302 command, stopping the program's execution at the start of its
3303 main subprogram. Support for this feature can be verified using
3304 the "-list-features" command, which should contain
3305 "exec-run-start-option".
3307 ** The new commands -catch-assert and -catch-exceptions insert
3308 catchpoints stopping the program when Ada exceptions are raised.
3310 ** The new command -info-ada-exceptions provides the equivalent of
3311 the new "info exceptions" command.
3313 * New system-wide configuration scripts
3314 A GDB installation now provides scripts suitable for use as system-wide
3315 configuration scripts for the following systems:
3319 * GDB now supports target-assigned range stepping with remote targets.
3320 This improves the performance of stepping source lines by reducing
3321 the number of control packets from/to GDB. See "New remote packets"
3324 * GDB now understands the element 'tvar' in the XML traceframe info.
3325 It has the id of the collected trace state variables.
3327 * On S/390 targets that provide the transactional-execution feature,
3328 the program interruption transaction diagnostic block (TDB) is now
3329 represented as a number of additional "registers" in GDB.
3331 * New remote packets
3335 The vCont packet supports a new 'r' action, that tells the remote
3336 stub to step through an address range itself, without GDB
3337 involvemement at each single-step.
3339 qXfer:libraries-svr4:read's annex
3340 The previously unused annex of the qXfer:libraries-svr4:read packet
3341 is now used to support passing an argument list. The remote stub
3342 reports support for this argument list to GDB's qSupported query.
3343 The defined arguments are "start" and "prev", used to reduce work
3344 necessary for library list updating, resulting in significant
3347 * New features in the GDB remote stub, GDBserver
3349 ** GDBserver now supports target-assisted range stepping. Currently
3350 enabled on x86/x86_64 GNU/Linux targets.
3352 ** GDBserver now adds element 'tvar' in the XML in the reply to
3353 'qXfer:traceframe-info:read'. It has the id of the collected
3354 trace state variables.
3356 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3359 * New 'z' formatter for printing and examining memory, this displays the
3360 value as hexadecimal zero padded on the left to the size of the type.
3362 * GDB can now use Windows x64 unwinding data.
3364 * The "set remotebaud" command has been replaced by "set serial baud".
3365 Similarly, "show remotebaud" has been replaced by "show serial baud".
3366 The "set remotebaud" and "show remotebaud" commands are still available
3367 to provide backward compatibility with older versions of GDB.
3369 *** Changes in GDB 7.6
3371 * Target record has been renamed to record-full.
3372 Record/replay is now enabled with the "record full" command.
3373 This also affects settings that are associated with full record/replay
3374 that have been moved from "set/show record" to "set/show record full":
3376 set|show record full insn-number-max
3377 set|show record full stop-at-limit
3378 set|show record full memory-query
3380 * A new record target "record-btrace" has been added. The new target
3381 uses hardware support to record the control-flow of a process. It
3382 does not support replaying the execution, but it implements the
3383 below new commands for investigating the recorded execution log.
3384 This new recording method can be enabled using:
3388 The "record-btrace" target is only available on Intel Atom processors
3389 and requires a Linux kernel 2.6.32 or later.
3391 * Two new commands have been added for record/replay to give information
3392 about the recorded execution without having to replay the execution.
3393 The commands are only supported by "record btrace".
3395 record instruction-history prints the execution history at
3396 instruction granularity
3398 record function-call-history prints the execution history at
3399 function granularity
3401 * New native configurations
3403 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3404 FreeBSD/powerpc powerpc*-*-freebsd
3405 x86_64/Cygwin x86_64-*-cygwin*
3406 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3410 ARM AArch64 aarch64*-*-elf
3411 ARM AArch64 GNU/Linux aarch64*-*-linux
3412 Lynx 178 PowerPC powerpc-*-lynx*178
3413 x86_64/Cygwin x86_64-*-cygwin*
3414 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3416 * If the configured location of system.gdbinit file (as given by the
3417 --with-system-gdbinit option at configure time) is in the
3418 data-directory (as specified by --with-gdb-datadir at configure
3419 time) or in one of its subdirectories, then GDB will look for the
3420 system-wide init file in the directory specified by the
3421 --data-directory command-line option.
3423 * New command line options:
3425 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3426 other initialization files, unlike -nx which disables all of them.
3428 * Removed command line options
3430 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3433 * The 'ptype' and 'whatis' commands now accept an argument to control
3436 * 'info proc' now works on some core files.
3440 ** Vectors can be created with gdb.Type.vector.
3442 ** Python's atexit.register now works in GDB.
3444 ** Types can be pretty-printed via a Python API.
3446 ** Python 3 is now supported (in addition to Python 2.4 or later)
3448 ** New class gdb.Architecture exposes GDB's internal representation
3449 of architecture in the Python API.
3451 ** New method Frame.architecture returns the gdb.Architecture object
3452 corresponding to the frame's architecture.
3454 * New Python-based convenience functions:
3456 ** $_memeq(buf1, buf2, length)
3457 ** $_streq(str1, str2)
3459 ** $_regex(str, regex)
3461 * The 'cd' command now defaults to using '~' (the home directory) if not
3464 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3465 default for GCC since November 2000.
3467 * The command 'forward-search' can now be abbreviated as 'fo'.
3469 * The command 'info tracepoints' can now display 'installed on target'
3470 or 'not installed on target' for each non-pending location of tracepoint.
3472 * New configure options
3474 --enable-libmcheck/--disable-libmcheck
3475 By default, development versions are built with -lmcheck on hosts
3476 that support it, in order to help track memory corruption issues.
3477 Release versions, on the other hand, are built without -lmcheck
3478 by default. The --enable-libmcheck/--disable-libmcheck configure
3479 options allow the user to override that default.
3480 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3481 This configure option allows the user to build GDB with
3482 libbabeltrace using which GDB can read Common Trace Format data.
3484 * New commands (for set/show, see "New options" below)
3487 Catch signals. This is similar to "handle", but allows commands and
3488 conditions to be attached.
3491 List the BFDs known to GDB.
3493 python-interactive [command]
3495 Start a Python interactive prompt, or evaluate the optional command
3496 and print the result of expressions.
3499 "py" is a new alias for "python".
3501 enable type-printer [name]...
3502 disable type-printer [name]...
3503 Enable or disable type printers.
3507 ** For the Renesas Super-H architecture, the "regs" command has been removed
3508 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3513 set print type methods (on|off)
3514 show print type methods
3515 Control whether method declarations are displayed by "ptype".
3516 The default is to show them.
3518 set print type typedefs (on|off)
3519 show print type typedefs
3520 Control whether typedef definitions are displayed by "ptype".
3521 The default is to show them.
3523 set filename-display basename|relative|absolute
3524 show filename-display
3525 Control the way in which filenames is displayed.
3526 The default is "relative", which preserves previous behavior.
3528 set trace-buffer-size
3529 show trace-buffer-size
3530 Request target to change the size of trace buffer.
3532 set remote trace-buffer-size-packet auto|on|off
3533 show remote trace-buffer-size-packet
3534 Control the use of the remote protocol `QTBuffer:size' packet.
3538 Control display of debugging messages related to ARM AArch64.
3541 set debug coff-pe-read
3542 show debug coff-pe-read
3543 Control display of debugging messages related to reading of COFF/PE
3548 Control display of debugging messages related to Mach-O symbols
3551 set debug notification
3552 show debug notification
3553 Control display of debugging info for async remote notification.
3557 ** Command parameter changes are now notified using new async record
3558 "=cmd-param-changed".
3559 ** Trace frame changes caused by command "tfind" are now notified using
3560 new async record "=traceframe-changed".
3561 ** The creation, deletion and modification of trace state variables
3562 are now notified using new async records "=tsv-created",
3563 "=tsv-deleted" and "=tsv-modified".
3564 ** The start and stop of process record are now notified using new
3565 async record "=record-started" and "=record-stopped".
3566 ** Memory changes are now notified using new async record
3568 ** The data-disassemble command response will include a "fullname" field
3569 containing the absolute file name when source has been requested.
3570 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3571 command, to allow pattern filling of memory areas.
3572 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3573 library load/unload events.
3574 ** The response to breakpoint commands and breakpoint async records
3575 includes an "installed" field containing a boolean state about each
3576 non-pending tracepoint location is whether installed on target or not.
3577 ** Output of the "-trace-status" command includes a "trace-file" field
3578 containing the name of the trace file being examined. This field is
3579 optional, and only present when examining a trace file.
3580 ** The "fullname" field is now always present along with the "file" field,
3581 even if the file cannot be found by GDB.
3583 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3584 You must have the LZMA library available when configuring GDB for this
3585 feature to be enabled. For more information, see:
3586 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3588 * New remote packets
3591 Set the size of trace buffer. The remote stub reports support for this
3592 packet to gdb's qSupported query.
3595 Enable Branch Trace Store (BTS)-based branch tracing for the current
3596 thread. The remote stub reports support for this packet to gdb's
3600 Disable branch tracing for the current thread. The remote stub reports
3601 support for this packet to gdb's qSupported query.
3604 Read the traced branches for the current thread. The remote stub
3605 reports support for this packet to gdb's qSupported query.
3607 *** Changes in GDB 7.5
3609 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3610 for more x32 ABI info.
3612 * GDB now supports access to MIPS DSP registers on Linux targets.
3614 * GDB now supports debugging microMIPS binaries.
3616 * The "info os" command on GNU/Linux can now display information on
3617 several new classes of objects managed by the operating system:
3618 "info os procgroups" lists process groups
3619 "info os files" lists file descriptors
3620 "info os sockets" lists internet-domain sockets
3621 "info os shm" lists shared-memory regions
3622 "info os semaphores" lists semaphores
3623 "info os msg" lists message queues
3624 "info os modules" lists loaded kernel modules
3626 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3627 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3628 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3629 options and inspect the probe arguments using the new $_probe_arg family
3630 of convenience variables. You can obtain more information about SystemTap
3631 in <http://sourceware.org/systemtap/>.
3633 * GDB now supports reversible debugging on ARM, it allows you to
3634 debug basic ARM and THUMB instructions, and provides
3635 record/replay support.
3637 * The option "symbol-reloading" has been deleted as it is no longer used.
3641 ** GDB commands implemented in Python can now be put in command class
3644 ** The "maint set python print-stack on|off" is now deleted.
3646 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3647 apply "flag enum"-style pretty-printing to any enum.
3649 ** gdb.lookup_symbol can now work when there is no current frame.
3651 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3652 the source at which the symbol was defined.
3654 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3655 method 'value'. The former indicates whether the symbol needs a
3656 frame in order to compute its value, and the latter computes the
3659 ** A new method 'referenced_value' on gdb.Value objects which can
3660 dereference pointer as well as C++ reference values.
3662 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3663 which return the global and static blocks (as gdb.Block objects),
3664 of the underlying symbol table, respectively.
3666 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3667 object associated with a PC value.
3669 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3670 of the address range occupied by code for the current source line.
3672 * Go language support.
3673 GDB now supports debugging programs written in the Go programming
3676 * GDBserver now supports stdio connections.
3677 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3679 * The binary "gdbtui" can no longer be built or installed.
3680 Use "gdb -tui" instead.
3682 * GDB will now print "flag" enums specially. A flag enum is one where
3683 all the enumerator values have no bits in common when pairwise
3684 "and"ed. When printing a value whose type is a flag enum, GDB will
3685 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3686 (gdb) print (enum E) 3
3689 * The filename part of a linespec will now match trailing components
3690 of a source file name. For example, "break gcc/expr.c:1000" will
3691 now set a breakpoint in build/gcc/expr.c, but not
3692 build/libcpp/expr.c.
3694 * The "info proc" and "generate-core-file" commands will now also
3695 work on remote targets connected to GDBserver on Linux.
3697 * The command "info catch" has been removed. It has been disabled
3698 since December 2007.
3700 * The "catch exception" and "catch assert" commands now accept
3701 a condition at the end of the command, much like the "break"
3702 command does. For instance:
3704 (gdb) catch exception Constraint_Error if Barrier = True
3706 Previously, it was possible to add a condition to such catchpoints,
3707 but it had to be done as a second step, after the catchpoint had been
3708 created, using the "condition" command.
3710 * The "info static-tracepoint-marker" command will now also work on
3711 native Linux targets with in-process agent.
3713 * GDB can now set breakpoints on inlined functions.
3715 * The .gdb_index section has been updated to include symbols for
3716 inlined functions. GDB will ignore older .gdb_index sections by
3717 default, which could cause symbol files to be loaded more slowly
3718 until their .gdb_index sections can be recreated. The new command
3719 "set use-deprecated-index-sections on" will cause GDB to use any older
3720 .gdb_index sections it finds. This will restore performance, but the
3721 ability to set breakpoints on inlined functions will be lost in symbol
3722 files with older .gdb_index sections.
3724 The .gdb_index section has also been updated to record more information
3725 about each symbol. This speeds up the "info variables", "info functions"
3726 and "info types" commands when used with programs having the .gdb_index
3727 section, as well as speeding up debugging with shared libraries using
3728 the .gdb_index section.
3730 * Ada support for GDB/MI Variable Objects has been added.
3732 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3737 ** New command -info-os is the MI equivalent of "info os".
3739 ** Output logs ("set logging" and related) now include MI output.
3743 ** "set use-deprecated-index-sections on|off"
3744 "show use-deprecated-index-sections on|off"
3745 Controls the use of deprecated .gdb_index sections.
3747 ** "catch load" and "catch unload" can be used to stop when a shared
3748 library is loaded or unloaded, respectively.
3750 ** "enable count" can be used to auto-disable a breakpoint after
3753 ** "info vtbl" can be used to show the virtual method tables for
3754 C++ and Java objects.
3756 ** "explore" and its sub commands "explore value" and "explore type"
3757 can be used to recursively explore values and types of
3758 expressions. These commands are available only if GDB is
3759 configured with '--with-python'.
3761 ** "info auto-load" shows status of all kinds of auto-loaded files,
3762 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3763 sequences of commands files, "info auto-load python-scripts"
3764 shows status of auto-loading Python script files,
3765 "info auto-load local-gdbinit" shows status of loading init file
3766 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3767 status of inferior specific thread debugging shared library loading.
3769 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3770 and "show auto-load-scripts" commands have been deprecated, use their
3771 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3772 and "show auto-load python-scripts" counterparts instead.
3774 ** "dprintf location,format,args..." creates a dynamic printf, which
3775 is basically a breakpoint that does a printf and immediately
3776 resumes your program's execution, so it is like a printf that you
3777 can insert dynamically at runtime instead of at compiletime.
3779 ** "set print symbol"
3781 Controls whether GDB attempts to display the symbol, if any,
3782 corresponding to addresses it prints. This defaults to "on", but
3783 you can set it to "off" to restore GDB's previous behavior.
3785 * Deprecated commands
3787 ** For the Renesas Super-H architecture, the "regs" command has been
3788 deprecated, and "info all-registers" should be used instead.
3792 Renesas RL78 rl78-*-elf
3793 HP OpenVMS ia64 ia64-hp-openvms*
3795 * GDBserver supports evaluation of breakpoint conditions. When
3796 support is advertised by GDBserver, GDB may be told to send the
3797 breakpoint conditions in bytecode form to GDBserver. GDBserver
3798 will only report the breakpoint trigger to GDB when its condition
3803 set mips compression
3804 show mips compression
3805 Select the compressed ISA encoding used in functions that have no symbol
3806 information available. The encoding can be set to either of:
3809 and is updated automatically from ELF file flags if available.
3811 set breakpoint condition-evaluation
3812 show breakpoint condition-evaluation
3813 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3814 GDBserver ("target"). Default option "auto" chooses the most efficient
3816 This option can improve debugger efficiency depending on the speed of the
3820 Disable auto-loading globally.
3823 Show auto-loading setting of all kinds of auto-loaded files.
3825 set auto-load gdb-scripts on|off
3826 show auto-load gdb-scripts
3827 Control auto-loading of GDB canned sequences of commands files.
3829 set auto-load python-scripts on|off
3830 show auto-load python-scripts
3831 Control auto-loading of Python script files.
3833 set auto-load local-gdbinit on|off
3834 show auto-load local-gdbinit
3835 Control loading of init file (.gdbinit) from current directory.
3837 set auto-load libthread-db on|off
3838 show auto-load libthread-db
3839 Control auto-loading of inferior specific thread debugging shared library.
3841 set auto-load scripts-directory <dir1>[:<dir2>...]
3842 show auto-load scripts-directory
3843 Set a list of directories from which to load auto-loaded scripts.
3844 Automatically loaded Python scripts and GDB scripts are located in one
3845 of the directories listed by this option.
3846 The delimiter (':' above) may differ according to the host platform.
3848 set auto-load safe-path <dir1>[:<dir2>...]
3849 show auto-load safe-path
3850 Set a list of directories from which it is safe to auto-load files.
3851 The delimiter (':' above) may differ according to the host platform.
3853 set debug auto-load on|off
3854 show debug auto-load
3855 Control display of debugging info for auto-loading the files above.
3857 set dprintf-style gdb|call|agent
3859 Control the way in which a dynamic printf is performed; "gdb"
3860 requests a GDB printf command, while "call" causes dprintf to call a
3861 function in the inferior. "agent" requests that the target agent
3862 (such as GDBserver) do the printing.
3864 set dprintf-function <expr>
3865 show dprintf-function
3866 set dprintf-channel <expr>
3867 show dprintf-channel
3868 Set the function and optional first argument to the call when using
3869 the "call" style of dynamic printf.
3871 set disconnected-dprintf on|off
3872 show disconnected-dprintf
3873 Control whether agent-style dynamic printfs continue to be in effect
3874 after GDB disconnects.
3876 * New configure options
3878 --with-auto-load-dir
3879 Configure default value for the 'set auto-load scripts-directory'
3880 setting above. It defaults to '$debugdir:$datadir/auto-load',
3881 $debugdir representing global debugging info directories (available
3882 via 'show debug-file-directory') and $datadir representing GDB's data
3883 directory (available via 'show data-directory').
3885 --with-auto-load-safe-path
3886 Configure default value for the 'set auto-load safe-path' setting
3887 above. It defaults to the --with-auto-load-dir setting.
3889 --without-auto-load-safe-path
3890 Set 'set auto-load safe-path' to '/', effectively disabling this
3893 * New remote packets
3895 z0/z1 conditional breakpoints extension
3897 The z0/z1 breakpoint insertion packets have been extended to carry
3898 a list of conditional expressions over to the remote stub depending on the
3899 condition evaluation mode. The use of this extension can be controlled
3900 via the "set remote conditional-breakpoints-packet" command.
3904 Specify the signals which the remote stub may pass to the debugged
3905 program without GDB involvement.
3907 * New command line options
3909 --init-command=FILE, -ix Like --command, -x but execute it
3910 before loading inferior.
3911 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3912 execute it before loading inferior.
3914 *** Changes in GDB 7.4
3916 * GDB now handles ambiguous linespecs more consistently; the existing
3917 FILE:LINE support has been expanded to other types of linespecs. A
3918 breakpoint will now be set on all matching locations in all
3919 inferiors, and locations will be added or removed according to
3922 * GDB now allows you to skip uninteresting functions and files when
3923 stepping with the "skip function" and "skip file" commands.
3925 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3926 and "show remote hardware-watchpoint-length-limit". These allows to
3927 set or show the maximum length limit (in bytes) of a remote
3928 target hardware watchpoint.
3930 This allows e.g. to use "unlimited" hardware watchpoints with the
3931 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3932 watchpoints are slower than real hardware watchpoints but are
3933 significantly faster than gdb software watchpoints.
3937 ** The register_pretty_printer function in module gdb.printing now takes
3938 an optional `replace' argument. If True, the new printer replaces any
3941 ** The "maint set python print-stack on|off" command has been
3942 deprecated and will be deleted in GDB 7.5.
3943 A new command: "set python print-stack none|full|message" has
3944 replaced it. Additionally, the default for "print-stack" is
3945 now "message", which just prints the error message without
3948 ** A prompt substitution hook (prompt_hook) is now available to the
3951 ** A new Python module, gdb.prompt has been added to the GDB Python
3952 modules library. This module provides functionality for
3953 escape sequences in prompts (used by set/show
3954 extended-prompt). These escape sequences are replaced by their
3955 corresponding value.
3957 ** Python commands and convenience-functions located in
3958 'data-directory'/python/gdb/command and
3959 'data-directory'/python/gdb/function are now automatically loaded
3962 ** Blocks now provide four new attributes. global_block and
3963 static_block will return the global and static blocks
3964 respectively. is_static and is_global are boolean attributes
3965 that indicate if the block is one of those two types.
3967 ** Symbols now provide the "type" attribute, the type of the symbol.
3969 ** The "gdb.breakpoint" function has been deprecated in favor of
3972 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3973 of a function. This class is based on the "finish" command
3974 available in the CLI.
3976 ** Type objects for struct and union types now allow access to
3977 the fields using standard Python dictionary (mapping) methods.
3978 For example, "some_type['myfield']" now works, as does
3979 "some_type.items()".
3981 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3984 ** A new function, "deep_items" has been added to the gdb.types
3985 module in the GDB Python modules library. This function returns
3986 an iterator over the fields of a struct or union type. Unlike
3987 the standard Python "iteritems" method, it will recursively traverse
3988 any anonymous fields.
3992 ** "*stopped" events can report several new "reason"s, such as
3995 ** Breakpoint changes are now notified using new async records, like
3996 "=breakpoint-modified".
3998 ** New command -ada-task-info.
4000 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4001 $sdir specifies the default system locations of shared libraries.
4002 $pdir specifies the directory where the libpthread used by the application
4005 GDB no longer looks in $sdir and $pdir after it has searched the directories
4006 mentioned in libthread-db-search-path. If you want to search those
4007 directories, they must be specified in libthread-db-search-path.
4008 The default value of libthread-db-search-path on GNU/Linux and Solaris
4009 systems is now "$sdir:$pdir".
4011 $pdir is not supported by gdbserver, it is currently ignored.
4012 $sdir is supported by gdbserver.
4014 * New configure option --with-iconv-bin.
4015 When using the internationalization support like the one in the GNU C
4016 library, GDB will invoke the "iconv" program to get a list of supported
4017 character sets. If this program lives in a non-standard location, one can
4018 use this option to specify where to find it.
4020 * When natively debugging programs on PowerPC BookE processors running
4021 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4022 watchpoints, which specify a mask in addition to an address to watch.
4023 The mask specifies that some bits of an address (the bits which are
4024 reset in the mask) should be ignored when matching the address accessed
4025 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4026 section in the user manual for more details.
4028 * The new option --once causes GDBserver to stop listening for connections once
4029 the first connection is made. The listening port used by GDBserver will
4030 become available after that.
4032 * New commands "info macros" and "alias" have been added.
4034 * New function parameters suffix @entry specifies value of function parameter
4035 at the time the function got called. Entry values are available only since
4041 "!" is now an alias of the "shell" command.
4042 Note that no space is needed between "!" and SHELL COMMAND.
4046 watch EXPRESSION mask MASK_VALUE
4047 The watch command now supports the mask argument which allows creation
4048 of masked watchpoints, if the current architecture supports this feature.
4050 info auto-load-scripts [REGEXP]
4051 This command was formerly named "maintenance print section-scripts".
4052 It is now generally useful and is no longer a maintenance-only command.
4054 info macro [-all] [--] MACRO
4055 The info macro command has new options `-all' and `--'. The first for
4056 printing all definitions of a macro. The second for explicitly specifying
4057 the end of arguments and the beginning of the macro name in case the macro
4058 name starts with a hyphen.
4060 collect[/s] EXPRESSIONS
4061 The tracepoint collect command now takes an optional modifier "/s"
4062 that directs it to dereference pointer-to-character types and
4063 collect the bytes of memory up to a zero byte. The behavior is
4064 similar to what you see when you use the regular print command on a
4065 string. An optional integer following the "/s" sets a bound on the
4066 number of bytes that will be collected.
4069 The trace start command now interprets any supplied arguments as a
4070 note to be recorded with the trace run, with an effect similar to
4071 setting the variable trace-notes.
4074 The trace stop command now interprets any arguments as a note to be
4075 mentioned along with the tstatus report that the trace was stopped
4076 with a command. The effect is similar to setting the variable
4079 * Tracepoints can now be enabled and disabled at any time after a trace
4080 experiment has been started using the standard "enable" and "disable"
4081 commands. It is now possible to start a trace experiment with no enabled
4082 tracepoints; GDB will display a warning, but will allow the experiment to
4083 begin, assuming that tracepoints will be enabled as needed while the trace
4086 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4087 locations with 4-byte instructions, when they were previously
4088 limited to locations with instructions of 5 bytes or longer.
4092 set debug dwarf2-read
4093 show debug dwarf2-read
4094 Turns on or off display of debugging messages related to reading
4095 DWARF debug info. The default is off.
4097 set debug symtab-create
4098 show debug symtab-create
4099 Turns on or off display of debugging messages related to symbol table
4100 creation. The default is off.
4103 show extended-prompt
4104 Set the GDB prompt, and allow escape sequences to be inserted to
4105 display miscellaneous information (see 'help set extended-prompt'
4106 for the list of sequences). This prompt (and any information
4107 accessed through the escape sequences) is updated every time the
4108 prompt is displayed.
4110 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4111 show print entry-values
4112 Set printing of frame argument values at function entry. In some cases
4113 GDB can determine the value of function argument which was passed by the
4114 function caller, even if the value was modified inside the called function.
4116 set debug entry-values
4117 show debug entry-values
4118 Control display of debugging info for determining frame argument values at
4119 function entry and virtual tail call frames.
4121 set basenames-may-differ
4122 show basenames-may-differ
4123 Set whether a source file may have multiple base names.
4124 (A "base name" is the name of a file with the directory part removed.
4125 Example: The base name of "/home/user/hello.c" is "hello.c".)
4126 If set, GDB will canonicalize file names (e.g., expand symlinks)
4127 before comparing them. Canonicalization is an expensive operation,
4128 but it allows the same file be known by more than one base name.
4129 If not set (the default), all source files are assumed to have just
4130 one base name, and gdb will do file name comparisons more efficiently.
4136 Set a user name and notes for the current and any future trace runs.
4137 This is useful for long-running and/or disconnected traces, to
4138 inform others (or yourself) as to who is running the trace, supply
4139 contact information, or otherwise explain what is going on.
4141 set trace-stop-notes
4142 show trace-stop-notes
4143 Set a note attached to the trace run, that is displayed when the
4144 trace has been stopped by a tstop command. This is useful for
4145 instance as an explanation, if you are stopping a trace run that was
4146 started by someone else.
4148 * New remote packets
4152 Dynamically enable a tracepoint in a started trace experiment.
4156 Dynamically disable a tracepoint in a started trace experiment.
4160 Set the user and notes of the trace run.
4164 Query the current status of a tracepoint.
4168 Query the minimum length of instruction at which a fast tracepoint may
4171 * Dcache size (number of lines) and line-size are now runtime-configurable
4172 via "set dcache line" and "set dcache line-size" commands.
4176 Texas Instruments TMS320C6x tic6x-*-*
4180 Renesas RL78 rl78-*-elf
4182 *** Changes in GDB 7.3.1
4184 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4186 *** Changes in GDB 7.3
4188 * GDB has a new command: "thread find [REGEXP]".
4189 It finds the thread id whose name, target id, or thread extra info
4190 matches the given regular expression.
4192 * The "catch syscall" command now works on mips*-linux* targets.
4194 * The -data-disassemble MI command now supports modes 2 and 3 for
4195 dumping the instruction opcodes.
4197 * New command line options
4199 -data-directory DIR Specify DIR as the "data-directory".
4200 This is mostly for testing purposes.
4202 * The "maint set python auto-load on|off" command has been renamed to
4203 "set auto-load-scripts on|off".
4205 * GDB has a new command: "set directories".
4206 It is like the "dir" command except that it replaces the
4207 source path list instead of augmenting it.
4209 * GDB now understands thread names.
4211 On GNU/Linux, "info threads" will display the thread name as set by
4212 prctl or pthread_setname_np.
4214 There is also a new command, "thread name", which can be used to
4215 assign a name internally for GDB to display.
4218 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4219 has been integrated into GDB.
4223 ** The function gdb.Write now accepts an optional keyword 'stream'.
4224 This keyword, when provided, will direct the output to either
4225 stdout, stderr, or GDB's logging output.
4227 ** Parameters can now be be sub-classed in Python, and in particular
4228 you may implement the get_set_doc and get_show_doc functions.
4229 This improves how Parameter set/show documentation is processed
4230 and allows for more dynamic content.
4232 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4233 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4234 have an is_valid method.
4236 ** Breakpoints can now be sub-classed in Python, and in particular
4237 you may implement a 'stop' function that is executed each time
4238 the inferior reaches that breakpoint.
4240 ** New function gdb.lookup_global_symbol looks up a global symbol.
4242 ** GDB values in Python are now callable if the value represents a
4243 function. For example, if 'some_value' represents a function that
4244 takes two integer parameters and returns a value, you can call
4245 that function like so:
4247 result = some_value (10,20)
4249 ** Module gdb.types has been added.
4250 It contains a collection of utilities for working with gdb.Types objects:
4251 get_basic_type, has_field, make_enum_dict.
4253 ** Module gdb.printing has been added.
4254 It contains utilities for writing and registering pretty-printers.
4255 New classes: PrettyPrinter, SubPrettyPrinter,
4256 RegexpCollectionPrettyPrinter.
4257 New function: register_pretty_printer.
4259 ** New commands "info pretty-printers", "enable pretty-printer" and
4260 "disable pretty-printer" have been added.
4262 ** gdb.parameter("directories") is now available.
4264 ** New function gdb.newest_frame returns the newest frame in the
4267 ** The gdb.InferiorThread class has a new "name" attribute. This
4268 holds the thread's name.
4270 ** Python Support for Inferior events.
4271 Python scripts can add observers to be notified of events
4272 occurring in the process being debugged.
4273 The following events are currently supported:
4274 - gdb.events.cont Continue event.
4275 - gdb.events.exited Inferior exited event.
4276 - gdb.events.stop Signal received, and Breakpoint hit events.
4280 ** GDB now puts template parameters in scope when debugging in an
4281 instantiation. For example, if you have:
4283 template<int X> int func (void) { return X; }
4285 then if you step into func<5>, "print X" will show "5". This
4286 feature requires proper debuginfo support from the compiler; it
4287 was added to GCC 4.5.
4289 ** The motion commands "next", "finish", "until", and "advance" now
4290 work better when exceptions are thrown. In particular, GDB will
4291 no longer lose control of the inferior; instead, the GDB will
4292 stop the inferior at the point at which the exception is caught.
4293 This functionality requires a change in the exception handling
4294 code that was introduced in GCC 4.5.
4296 * GDB now follows GCC's rules on accessing volatile objects when
4297 reading or writing target state during expression evaluation.
4298 One notable difference to prior behavior is that "print x = 0"
4299 no longer generates a read of x; the value of the assignment is
4300 now always taken directly from the value being assigned.
4302 * GDB now has some support for using labels in the program's source in
4303 linespecs. For instance, you can use "advance label" to continue
4304 execution to a label.
4306 * GDB now has support for reading and writing a new .gdb_index
4307 section. This section holds a fast index of DWARF debugging
4308 information and can be used to greatly speed up GDB startup and
4309 operation. See the documentation for `save gdb-index' for details.
4311 * The "watch" command now accepts an optional "-location" argument.
4312 When used, this causes GDB to watch the memory referred to by the
4313 expression. Such a watchpoint is never deleted due to it going out
4316 * GDB now supports thread debugging of core dumps on GNU/Linux.
4318 GDB now activates thread debugging using the libthread_db library
4319 when debugging GNU/Linux core dumps, similarly to when debugging
4320 live processes. As a result, when debugging a core dump file, GDB
4321 is now able to display pthread_t ids of threads. For example, "info
4322 threads" shows the same output as when debugging the process when it
4323 was live. In earlier releases, you'd see something like this:
4326 * 1 LWP 6780 main () at main.c:10
4328 While now you see this:
4331 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4333 It is also now possible to inspect TLS variables when debugging core
4336 When debugging a core dump generated on a machine other than the one
4337 used to run GDB, you may need to point GDB at the correct
4338 libthread_db library with the "set libthread-db-search-path"
4339 command. See the user manual for more details on this command.
4341 * When natively debugging programs on PowerPC BookE processors running
4342 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4343 which stop execution of the inferior whenever it executes an instruction
4344 at any address within the specified range. See the "PowerPC Embedded"
4345 section in the user manual for more details.
4347 * New features in the GDB remote stub, GDBserver
4349 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4350 and i686 LynxOS (version 5.x).
4352 ** GDBserver is now supported on Blackfin Linux.
4354 * New native configurations
4356 ia64 HP-UX ia64-*-hpux*
4360 Analog Devices, Inc. Blackfin Processor bfin-*
4362 * Ada task switching is now supported on sparc-elf targets when
4363 debugging a program using the Ravenscar Profile. For more information,
4364 see the "Tasking Support when using the Ravenscar Profile" section
4365 in the GDB user manual.
4367 * Guile support was removed.
4369 * New features in the GNU simulator
4371 ** The --map-info flag lists all known core mappings.
4373 ** CFI flashes may be simulated via the "cfi" device.
4375 *** Changes in GDB 7.2
4377 * Shared library support for remote targets by default
4379 When GDB is configured for a generic, non-OS specific target, like
4380 for example, --target=arm-eabi or one of the many *-*-elf targets,
4381 GDB now queries remote stubs for loaded shared libraries using the
4382 `qXfer:libraries:read' packet. Previously, shared library support
4383 was always disabled for such configurations.
4387 ** Argument Dependent Lookup (ADL)
4389 In C++ ADL lookup directs function search to the namespaces of its
4390 arguments even if the namespace has not been imported.
4400 Here the compiler will search for `foo' in the namespace of 'b'
4401 and find A::foo. GDB now supports this. This construct is commonly
4402 used in the Standard Template Library for operators.
4404 ** Improved User Defined Operator Support
4406 In addition to member operators, GDB now supports lookup of operators
4407 defined in a namespace and imported with a `using' directive, operators
4408 defined in the global scope, operators imported implicitly from an
4409 anonymous namespace, and the ADL operators mentioned in the previous
4411 GDB now also supports proper overload resolution for all the previously
4412 mentioned flavors of operators.
4414 ** static const class members
4416 Printing of static const class members that are initialized in the
4417 class definition has been fixed.
4419 * Windows Thread Information Block access.
4421 On Windows targets, GDB now supports displaying the Windows Thread
4422 Information Block (TIB) structure. This structure is visible either
4423 by using the new command `info w32 thread-information-block' or, by
4424 dereferencing the new convenience variable named `$_tlb', a
4425 thread-specific pointer to the TIB. This feature is also supported
4426 when remote debugging using GDBserver.
4428 * Static tracepoints
4430 Static tracepoints are calls in the user program into a tracing
4431 library. One such library is a port of the LTTng kernel tracer to
4432 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4433 When debugging with GDBserver, GDB now supports combining the GDB
4434 tracepoint machinery with such libraries. For example: the user can
4435 use GDB to probe a static tracepoint marker (a call from the user
4436 program into the tracing library) with the new "strace" command (see
4437 "New commands" below). This creates a "static tracepoint" in the
4438 breakpoint list, that can be manipulated with the same feature set
4439 as fast and regular tracepoints. E.g., collect registers, local and
4440 global variables, collect trace state variables, and define
4441 tracepoint conditions. In addition, the user can collect extra
4442 static tracepoint marker specific data, by collecting the new
4443 $_sdata internal variable. When analyzing the trace buffer, you can
4444 inspect $_sdata like any other variable available to GDB. For more
4445 information, see the "Tracepoints" chapter in GDB user manual. New
4446 remote packets have been defined to support static tracepoints, see
4447 the "New remote packets" section below.
4449 * Better reconstruction of tracepoints after disconnected tracing
4451 GDB will attempt to download the original source form of tracepoint
4452 definitions when starting a trace run, and then will upload these
4453 upon reconnection to the target, resulting in a more accurate
4454 reconstruction of the tracepoints that are in use on the target.
4458 You can now exercise direct control over the ways that GDB can
4459 affect your program. For instance, you can disallow the setting of
4460 breakpoints, so that the program can run continuously (assuming
4461 non-stop mode). In addition, the "observer" variable is available
4462 to switch all of the different controls; in observer mode, GDB
4463 cannot affect the target's behavior at all, which is useful for
4464 tasks like diagnosing live systems in the field.
4466 * The new convenience variable $_thread holds the number of the
4469 * New remote packets
4473 Return the address of the Windows Thread Information Block of a given thread.
4477 In response to several of the tracepoint packets, the target may now
4478 also respond with a number of intermediate `qRelocInsn' request
4479 packets before the final result packet, to have GDB handle
4480 relocating an instruction to execute at a different address. This
4481 is particularly useful for stubs that support fast tracepoints. GDB
4482 reports support for this feature in the qSupported packet.
4486 List static tracepoint markers in the target program.
4490 List static tracepoint markers at a given address in the target
4493 qXfer:statictrace:read
4495 Read the static trace data collected (by a `collect $_sdata'
4496 tracepoint action). The remote stub reports support for this packet
4497 to gdb's qSupported query.
4501 Send the current settings of GDB's permission flags.
4505 Send part of the source (textual) form of a tracepoint definition,
4506 which includes location, conditional, and action list.
4508 * The source command now accepts a -s option to force searching for the
4509 script in the source search path even if the script name specifies
4512 * New features in the GDB remote stub, GDBserver
4514 - GDBserver now support tracepoints (including fast tracepoints, and
4515 static tracepoints). The feature is currently supported by the
4516 i386-linux and amd64-linux builds. See the "Tracepoints support
4517 in gdbserver" section in the manual for more information.
4519 GDBserver JIT compiles the tracepoint's conditional agent
4520 expression bytecode into native code whenever possible for low
4521 overhead dynamic tracepoints conditionals. For such tracepoints,
4522 an expression that examines program state is evaluated when the
4523 tracepoint is reached, in order to determine whether to capture
4524 trace data. If the condition is simple and false, processing the
4525 tracepoint finishes very quickly and no data is gathered.
4527 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4528 for static tracepoints support.
4530 - GDBserver now supports x86_64 Windows 64-bit debugging.
4532 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4533 it understands register description.
4535 * The --batch flag now disables pagination and queries.
4537 * X86 general purpose registers
4539 GDB now supports reading/writing byte, word and double-word x86
4540 general purpose registers directly. This means you can use, say,
4541 $ah or $ax to refer, respectively, to the byte register AH and
4542 16-bit word register AX that are actually portions of the 32-bit
4543 register EAX or 64-bit register RAX.
4545 * The `commands' command now accepts a range of breakpoints to modify.
4546 A plain `commands' following a command that creates multiple
4547 breakpoints affects all the breakpoints set by that command. This
4548 applies to breakpoints set by `rbreak', and also applies when a
4549 single `break' command creates multiple breakpoints (e.g.,
4550 breakpoints on overloaded c++ functions).
4552 * The `rbreak' command now accepts a filename specification as part of
4553 its argument, limiting the functions selected by the regex to those
4554 in the specified file.
4556 * Support for remote debugging Windows and SymbianOS shared libraries
4557 from Unix hosts has been improved. Non Windows GDB builds now can
4558 understand target reported file names that follow MS-DOS based file
4559 system semantics, such as file names that include drive letters and
4560 use the backslash character as directory separator. This makes it
4561 possible to transparently use the "set sysroot" and "set
4562 solib-search-path" on Unix hosts to point as host copies of the
4563 target's shared libraries. See the new command "set
4564 target-file-system-kind" described below, and the "Commands to
4565 specify files" section in the user manual for more information.
4569 eval template, expressions...
4570 Convert the values of one or more expressions under the control
4571 of the string template to a command line, and call it.
4573 set target-file-system-kind unix|dos-based|auto
4574 show target-file-system-kind
4575 Set or show the assumed file system kind for target reported file
4578 save breakpoints <filename>
4579 Save all current breakpoint definitions to a file suitable for use
4580 in a later debugging session. To read the saved breakpoint
4581 definitions, use the `source' command.
4583 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4586 info static-tracepoint-markers
4587 Display information about static tracepoint markers in the target.
4589 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4590 Define a static tracepoint by probing a marker at the given
4591 function, line, address, or marker ID.
4595 Enable and disable observer mode.
4597 set may-write-registers on|off
4598 set may-write-memory on|off
4599 set may-insert-breakpoints on|off
4600 set may-insert-tracepoints on|off
4601 set may-insert-fast-tracepoints on|off
4602 set may-interrupt on|off
4603 Set individual permissions for GDB effects on the target. Note that
4604 some of these settings can have undesirable or surprising
4605 consequences, particularly when changed in the middle of a session.
4606 For instance, disabling the writing of memory can prevent
4607 breakpoints from being inserted, cause single-stepping to fail, or
4608 even crash your program, if you disable after breakpoints have been
4609 inserted. However, GDB should not crash.
4611 set record memory-query on|off
4612 show record memory-query
4613 Control whether to stop the inferior if memory changes caused
4614 by an instruction cannot be recorded.
4619 The disassemble command now supports "start,+length" form of two arguments.
4623 ** GDB now provides a new directory location, called the python directory,
4624 where Python scripts written for GDB can be installed. The location
4625 of that directory is <data-directory>/python, where <data-directory>
4626 is the GDB data directory. For more details, see section `Scripting
4627 GDB using Python' in the manual.
4629 ** The GDB Python API now has access to breakpoints, symbols, symbol
4630 tables, program spaces, inferiors, threads and frame's code blocks.
4631 Additionally, GDB Parameters can now be created from the API, and
4632 manipulated via set/show in the CLI.
4634 ** New functions gdb.target_charset, gdb.target_wide_charset,
4635 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4637 ** New exception gdb.GdbError.
4639 ** Pretty-printers are now also looked up in the current program space.
4641 ** Pretty-printers can now be individually enabled and disabled.
4643 ** GDB now looks for names of Python scripts to auto-load in a
4644 special section named `.debug_gdb_scripts', in addition to looking
4645 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4647 * Tracepoint actions were unified with breakpoint commands. In particular,
4648 there are no longer differences in "info break" output for breakpoints and
4649 tracepoints and the "commands" command can be used for both tracepoints and
4650 regular breakpoints.
4654 ARM Symbian arm*-*-symbianelf*
4656 * D language support.
4657 GDB now supports debugging programs written in the D programming
4660 * GDB now supports the extended ptrace interface for PowerPC which is
4661 available since Linux kernel version 2.6.34. This automatically enables
4662 any hardware breakpoints and additional hardware watchpoints available in
4663 the processor. The old ptrace interface exposes just one hardware
4664 watchpoint and no hardware breakpoints.
4666 * GDB is now able to use the Data Value Compare (DVC) register available on
4667 embedded PowerPC processors to implement in hardware simple watchpoint
4668 conditions of the form:
4670 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4672 This works in native GDB running on Linux kernels with the extended ptrace
4673 interface mentioned above.
4675 *** Changes in GDB 7.1
4679 ** Namespace Support
4681 GDB now supports importing of namespaces in C++. This enables the
4682 user to inspect variables from imported namespaces. Support for
4683 namepace aliasing has also been added. So, if a namespace is
4684 aliased in the current scope (e.g. namepace C=A; ) the user can
4685 print variables using the alias (e.g. (gdb) print C::x).
4689 All known bugs relating to the printing of virtual base class were
4690 fixed. It is now possible to call overloaded static methods using a
4695 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4696 and reinterpret_cast<> are now handled by the C++ expression parser.
4700 Xilinx MicroBlaze microblaze-*-*
4705 Xilinx MicroBlaze microblaze
4708 * Multi-program debugging.
4710 GDB now has support for multi-program (a.k.a. multi-executable or
4711 multi-exec) debugging. This allows for debugging multiple inferiors
4712 simultaneously each running a different program under the same GDB
4713 session. See "Debugging Multiple Inferiors and Programs" in the
4714 manual for more information. This implied some user visible changes
4715 in the multi-inferior support. For example, "info inferiors" now
4716 lists inferiors that are not running yet or that have exited
4717 already. See also "New commands" and "New options" below.
4719 * New tracing features
4721 GDB's tracepoint facility now includes several new features:
4723 ** Trace state variables
4725 GDB tracepoints now include support for trace state variables, which
4726 are variables managed by the target agent during a tracing
4727 experiment. They are useful for tracepoints that trigger each
4728 other, so for instance one tracepoint can count hits in a variable,
4729 and then a second tracepoint has a condition that is true when the
4730 count reaches a particular value. Trace state variables share the
4731 $-syntax of GDB convenience variables, and can appear in both
4732 tracepoint actions and condition expressions. Use the "tvariable"
4733 command to create, and "info tvariables" to view; see "Trace State
4734 Variables" in the manual for more detail.
4738 GDB now includes an option for defining fast tracepoints, which
4739 targets may implement more efficiently, such as by installing a jump
4740 into the target agent rather than a trap instruction. The resulting
4741 speedup can be by two orders of magnitude or more, although the
4742 tradeoff is that some program locations on some target architectures
4743 might not allow fast tracepoint installation, for instance if the
4744 instruction to be replaced is shorter than the jump. To request a
4745 fast tracepoint, use the "ftrace" command, with syntax identical to
4746 the regular trace command.
4748 ** Disconnected tracing
4750 It is now possible to detach GDB from the target while it is running
4751 a trace experiment, then reconnect later to see how the experiment
4752 is going. In addition, a new variable disconnected-tracing lets you
4753 tell the target agent whether to continue running a trace if the
4754 connection is lost unexpectedly.
4758 GDB now has the ability to save the trace buffer into a file, and
4759 then use that file as a target, similarly to you can do with
4760 corefiles. You can select trace frames, print data that was
4761 collected in them, and use tstatus to display the state of the
4762 tracing run at the moment that it was saved. To create a trace
4763 file, use "tsave <filename>", and to use it, do "target tfile
4766 ** Circular trace buffer
4768 You can ask the target agent to handle the trace buffer as a
4769 circular buffer, discarding the oldest trace frames to make room for
4770 newer ones, by setting circular-trace-buffer to on. This feature may
4771 not be available for all target agents.
4776 The disassemble command, when invoked with two arguments, now requires
4777 the arguments to be comma-separated.
4780 The info variables command now displays variable definitions. Files
4781 which only declare a variable are not shown.
4784 The source command is now capable of sourcing Python scripts.
4785 This feature is dependent on the debugger being build with Python
4788 Related to this enhancement is also the introduction of a new command
4789 "set script-extension" (see below).
4791 * New commands (for set/show, see "New options" below)
4793 record save [<FILENAME>]
4794 Save a file (in core file format) containing the process record
4795 execution log for replay debugging at a later time.
4797 record restore <FILENAME>
4798 Restore the process record execution log that was saved at an
4799 earlier time, for replay debugging.
4801 add-inferior [-copies <N>] [-exec <FILENAME>]
4804 clone-inferior [-copies <N>] [ID]
4805 Make a new inferior ready to execute the same program another
4806 inferior has loaded.
4811 maint info program-spaces
4812 List the program spaces loaded into GDB.
4814 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4815 show remote interrupt-sequence
4816 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4817 as the sequence to the remote target in order to interrupt the execution.
4818 Ctrl-C is a default. Some system prefers BREAK which is high level of
4819 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4820 Magic SysRq g. It is BREAK signal and character 'g'.
4822 set remote interrupt-on-connect [on | off]
4823 show remote interrupt-on-connect
4824 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4825 remote target when gdb connects to it. This is needed when you debug
4828 set remotebreak [on | off]
4830 Deprecated. Use "set/show remote interrupt-sequence" instead.
4832 tvariable $NAME [ = EXP ]
4833 Create or modify a trace state variable.
4836 List trace state variables and their values.
4838 delete tvariable $NAME ...
4839 Delete one or more trace state variables.
4842 Evaluate the given expressions without collecting anything into the
4843 trace buffer. (Valid in tracepoint actions only.)
4845 ftrace FN / FILE:LINE / *ADDR
4846 Define a fast tracepoint at the given function, line, or address.
4848 * New expression syntax
4850 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4851 GDB now parses 0b101010 identically with 42.
4855 set follow-exec-mode new|same
4856 show follow-exec-mode
4857 Control whether GDB reuses the same inferior across an exec call or
4858 creates a new one. This is useful to be able to restart the old
4859 executable after the inferior having done an exec call.
4861 set default-collect EXPR, ...
4862 show default-collect
4863 Define a list of expressions to be collected at each tracepoint.
4864 This is a useful way to ensure essential items are not overlooked,
4865 such as registers or a critical global variable.
4867 set disconnected-tracing
4868 show disconnected-tracing
4869 If set to 1, the target is instructed to continue tracing if it
4870 loses its connection to GDB. If 0, the target is to stop tracing
4873 set circular-trace-buffer
4874 show circular-trace-buffer
4875 If set to on, the target is instructed to use a circular trace buffer
4876 and discard the oldest trace frames instead of stopping the trace due
4877 to a full trace buffer. If set to off, the trace stops when the buffer
4878 fills up. Some targets may not support this.
4880 set script-extension off|soft|strict
4881 show script-extension
4882 If set to "off", the debugger does not perform any script language
4883 recognition, and all sourced files are assumed to be GDB scripts.
4884 If set to "soft" (the default), files are sourced according to
4885 filename extension, falling back to GDB scripts if the first
4887 If set to "strict", files are sourced according to filename extension.
4889 set ada trust-PAD-over-XVS on|off
4890 show ada trust-PAD-over-XVS
4891 If off, activate a workaround against a bug in the debugging information
4892 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4893 the GCC sources for more information about the GNAT encoding and
4894 PAD types in particular). It is always safe to set this option to
4895 off, but this introduces a slight performance penalty. The default
4898 * Python API Improvements
4900 ** GDB provides the new class gdb.LazyString. This is useful in
4901 some pretty-printing cases. The new method gdb.Value.lazy_string
4902 provides a simple way to create objects of this type.
4904 ** The fields returned by gdb.Type.fields now have an
4905 `is_base_class' attribute.
4907 ** The new method gdb.Type.range returns the range of an array type.
4909 ** The new method gdb.parse_and_eval can be used to parse and
4910 evaluate an expression.
4912 * New remote packets
4915 Define a trace state variable.
4918 Get the current value of a trace state variable.
4921 Set desired tracing behavior upon disconnection.
4924 Set the trace buffer to be linear or circular.
4927 Get data about the tracepoints currently in use.
4931 Process record now works correctly with hardware watchpoints.
4933 Multiple bug fixes have been made to the mips-irix port, making it
4934 much more reliable. In particular:
4935 - Debugging threaded applications is now possible again. Previously,
4936 GDB would hang while starting the program, or while waiting for
4937 the program to stop at a breakpoint.
4938 - Attaching to a running process no longer hangs.
4939 - An error occurring while loading a core file has been fixed.
4940 - Changing the value of the PC register now works again. This fixes
4941 problems observed when using the "jump" command, or when calling
4942 a function from GDB, or even when assigning a new value to $pc.
4943 - With the "finish" and "return" commands, the return value for functions
4944 returning a small array is now correctly printed.
4945 - It is now possible to break on shared library code which gets executed
4946 during a shared library init phase (code executed while executing
4947 their .init section). Previously, the breakpoint would have no effect.
4948 - GDB is now able to backtrace through the signal handler for
4949 non-threaded programs.
4951 PIE (Position Independent Executable) programs debugging is now supported.
4952 This includes debugging execution of PIC (Position Independent Code) shared
4953 libraries although for that, it should be possible to run such libraries as an
4956 *** Changes in GDB 7.0
4958 * GDB now has an interface for JIT compilation. Applications that
4959 dynamically generate code can create symbol files in memory and register
4960 them with GDB. For users, the feature should work transparently, and
4961 for JIT developers, the interface is documented in the GDB manual in the
4962 "JIT Compilation Interface" chapter.
4964 * Tracepoints may now be conditional. The syntax is as for
4965 breakpoints; either an "if" clause appended to the "trace" command,
4966 or the "condition" command is available. GDB sends the condition to
4967 the target for evaluation using the same bytecode format as is used
4968 for tracepoint actions.
4970 * The disassemble command now supports: an optional /r modifier, print the
4971 raw instructions in hex as well as in symbolic form, and an optional /m
4972 modifier to print mixed source+assembly.
4974 * Process record and replay
4976 In a architecture environment that supports ``process record and
4977 replay'', ``process record and replay'' target can record a log of
4978 the process execution, and replay it with both forward and reverse
4981 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4982 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4983 set execution-direction {forward|reverse}, for targets that support
4986 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4987 feature is available with a native GDB running on kernel version
4990 * GDB now has support for multi-byte and wide character sets on the
4991 target. Strings whose character type is wchar_t, char16_t, or
4992 char32_t are now correctly printed. GDB supports wide- and unicode-
4993 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4994 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4995 `printf'. This feature requires iconv to work properly; if your
4996 system does not have a working iconv, GDB can use GNU libiconv. See
4997 the installation instructions for more information.
4999 * GDB now supports automatic retrieval of shared library files from
5000 remote targets. To use this feature, specify a system root that begins
5001 with the `remote:' prefix, either via the `set sysroot' command or via
5002 the `--with-sysroot' configure-time option.
5004 * "info sharedlibrary" now takes an optional regex of libraries to show,
5005 and it now reports if a shared library has no debugging information.
5007 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5008 now complete on file names.
5010 * When completing in expressions, gdb will attempt to limit
5011 completions to allowable structure or union fields, where appropriate.
5012 For instance, consider:
5014 # struct example { int f1; double f2; };
5015 # struct example variable;
5018 If the user types TAB at the end of this command line, the available
5019 completions will be "f1" and "f2".
5021 * Inlined functions are now supported. They show up in backtraces, and
5022 the "step", "next", and "finish" commands handle them automatically.
5024 * GDB now supports the token-splicing (##) and stringification (#)
5025 operators when expanding macros. It also supports variable-arity
5028 * GDB now supports inspecting extra signal information, exported by
5029 the new $_siginfo convenience variable. The feature is currently
5030 implemented on linux ARM, i386 and amd64.
5032 * GDB can now display the VFP floating point registers and NEON vector
5033 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5034 can provide these registers (requires Linux 2.6.30 or later). Remote
5035 and simulator targets may also provide them.
5037 * New remote packets
5040 Search memory for a sequence of bytes.
5043 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5044 operation over reliable transport links. Use of this packet is
5045 controlled by the `set remote noack-packet' command.
5048 Kill the process with the specified process ID. Use this in preference
5049 to `k' when multiprocess protocol extensions are supported.
5052 Obtains additional operating system information
5056 Read or write additional signal information.
5058 * Removed remote protocol undocumented extension
5060 An undocumented extension to the remote protocol's `S' stop reply
5061 packet that permitted the stub to pass a process id was removed.
5062 Remote servers should use the `T' stop reply packet instead.
5064 * GDB now supports multiple function calling conventions according to the
5065 DWARF-2 DW_AT_calling_convention function attribute.
5067 * The SH target utilizes the aforementioned change to distinguish between gcc
5068 and Renesas calling convention. It also adds the new CLI commands
5069 `set/show sh calling-convention'.
5071 * GDB can now read compressed debug sections, as produced by GNU gold
5072 with the --compress-debug-sections=zlib flag.
5074 * 64-bit core files are now supported on AIX.
5076 * Thread switching is now supported on Tru64.
5078 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5079 which will be allocated using malloc later in program execution.
5081 * The qXfer:libraries:read remote protocol packet now allows passing a
5082 list of section offsets.
5084 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5085 conditions handling signals delivered during attach or thread creation
5086 have also been fixed.
5088 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5089 From the user's standpoint, all unqualified instances of True and False
5090 are treated as the standard definitions, regardless of context.
5092 * GDB now parses C++ symbol and type names more flexibly. For
5095 template<typename T> class C { };
5098 GDB will now correctly handle all of:
5100 ptype C<char const *>
5101 ptype C<char const*>
5102 ptype C<const char *>
5103 ptype C<const char*>
5105 * New features in the GDB remote stub, gdbserver
5107 - The "--wrapper" command-line argument tells gdbserver to use a
5108 wrapper program to launch programs for debugging.
5110 - On PowerPC and S/390 targets, it is now possible to use a single
5111 gdbserver executable to debug both 32-bit and 64-bit programs.
5112 (This requires gdbserver itself to be built as a 64-bit executable.)
5114 - gdbserver uses the new noack protocol mode for TCP connections to
5115 reduce communications latency, if also supported and enabled in GDB.
5117 - Support for the sparc64-linux-gnu target is now included in
5120 - The amd64-linux build of gdbserver now supports debugging both
5121 32-bit and 64-bit programs.
5123 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5124 now support hardware watchpoints, and will use them automatically
5129 GDB now has support for scripting using Python. Whether this is
5130 available is determined at configure time.
5132 New GDB commands can now be written in Python.
5134 * Ada tasking support
5136 Ada tasks can now be inspected in GDB. The following commands have
5140 Print the list of Ada tasks.
5142 Print detailed information about task number N.
5144 Print the task number of the current task.
5146 Switch the context of debugging to task number N.
5148 * Support for user-defined prefixed commands. The "define" command can
5149 add new commands to existing prefixes, e.g. "target".
5151 * Multi-inferior, multi-process debugging.
5153 GDB now has generalized support for multi-inferior debugging. See
5154 "Debugging Multiple Inferiors" in the manual for more information.
5155 Although availability still depends on target support, the command
5156 set is more uniform now. The GNU/Linux specific multi-forks support
5157 has been migrated to this new framework. This implied some user
5158 visible changes; see "New commands" and also "Removed commands"
5161 * Target descriptions can now describe the target OS ABI. See the
5162 "Target Description Format" section in the user manual for more
5165 * Target descriptions can now describe "compatible" architectures
5166 to indicate that the target can execute applications for a different
5167 architecture in addition to those for the main target architecture.
5168 See the "Target Description Format" section in the user manual for
5171 * Multi-architecture debugging.
5173 GDB now includes general supports for debugging applications on
5174 hybrid systems that use more than one single processor architecture
5175 at the same time. Each such hybrid architecture still requires
5176 specific support to be added. The only hybrid architecture supported
5177 in this version of GDB is the Cell Broadband Engine.
5179 * GDB now supports integrated debugging of Cell/B.E. applications that
5180 use both the PPU and SPU architectures. To enable support for hybrid
5181 Cell/B.E. debugging, you need to configure GDB to support both the
5182 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5183 --enable-targets configure option.
5185 * Non-stop mode debugging.
5187 For some targets, GDB now supports an optional mode of operation in
5188 which you can examine stopped threads while other threads continue
5189 to execute freely. This is referred to as non-stop mode, with the
5190 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5191 section in the user manual for more information.
5193 To be able to support remote non-stop debugging, a remote stub needs
5194 to implement the non-stop mode remote protocol extensions, as
5195 described in the "Remote Non-Stop" section of the user manual. The
5196 GDB remote stub, gdbserver, has been adjusted to support these
5197 extensions on linux targets.
5199 * New commands (for set/show, see "New options" below)
5201 catch syscall [NAME(S) | NUMBER(S)]
5202 Catch system calls. Arguments, which should be names of system
5203 calls or their numbers, mean catch only those syscalls. Without
5204 arguments, every syscall will be caught. When the inferior issues
5205 any of the specified syscalls, GDB will stop and announce the system
5206 call, both when it is called and when its call returns. This
5207 feature is currently available with a native GDB running on the
5208 Linux Kernel, under the following architectures: x86, x86_64,
5209 PowerPC and PowerPC64.
5211 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5213 Search memory for a sequence of bytes.
5215 maint set python print-stack
5216 maint show python print-stack
5217 Show a stack trace when an error is encountered in a Python script.
5220 Invoke CODE by passing it to the Python interpreter.
5225 These allow macros to be defined, undefined, and listed
5229 Show operating system information about processes.
5232 List the inferiors currently under GDB's control.
5235 Switch focus to inferior number NUM.
5238 Detach from inferior number NUM.
5241 Kill inferior number NUM.
5245 set spu stop-on-load
5246 show spu stop-on-load
5247 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5249 set spu auto-flush-cache
5250 show spu auto-flush-cache
5251 Control whether to automatically flush the software-managed cache
5252 during Cell/B.E. debugging.
5254 set sh calling-convention
5255 show sh calling-convention
5256 Control the calling convention used when calling SH target functions.
5259 show debug timestamp
5260 Control display of timestamps with GDB debugging output.
5262 set disassemble-next-line
5263 show disassemble-next-line
5264 Control display of disassembled source lines or instructions when
5267 set remote noack-packet
5268 show remote noack-packet
5269 Set/show the use of remote protocol QStartNoAckMode packet. See above
5270 under "New remote packets."
5272 set remote query-attached-packet
5273 show remote query-attached-packet
5274 Control use of remote protocol `qAttached' (query-attached) packet.
5276 set remote read-siginfo-object
5277 show remote read-siginfo-object
5278 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5281 set remote write-siginfo-object
5282 show remote write-siginfo-object
5283 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5286 set remote reverse-continue
5287 show remote reverse-continue
5288 Control use of remote protocol 'bc' (reverse-continue) packet.
5290 set remote reverse-step
5291 show remote reverse-step
5292 Control use of remote protocol 'bs' (reverse-step) packet.
5294 set displaced-stepping
5295 show displaced-stepping
5296 Control displaced stepping mode. Displaced stepping is a way to
5297 single-step over breakpoints without removing them from the debuggee.
5298 Also known as "out-of-line single-stepping".
5301 show debug displaced
5302 Control display of debugging info for displaced stepping.
5304 maint set internal-error
5305 maint show internal-error
5306 Control what GDB does when an internal error is detected.
5308 maint set internal-warning
5309 maint show internal-warning
5310 Control what GDB does when an internal warning is detected.
5315 Use a wrapper program to launch programs for debugging.
5317 set multiple-symbols (all|ask|cancel)
5318 show multiple-symbols
5319 The value of this variable can be changed to adjust the debugger behavior
5320 when an expression or a breakpoint location contains an ambiguous symbol
5321 name (an overloaded function name, for instance).
5323 set breakpoint always-inserted
5324 show breakpoint always-inserted
5325 Keep breakpoints always inserted in the target, as opposed to inserting
5326 them when resuming the target, and removing them when the target stops.
5327 This option can improve debugger performance on slow remote targets.
5329 set arm fallback-mode (arm|thumb|auto)
5330 show arm fallback-mode
5331 set arm force-mode (arm|thumb|auto)
5333 These commands control how ARM GDB determines whether instructions
5334 are ARM or Thumb. The default for both settings is auto, which uses
5335 the current CPSR value for instructions without symbols; previous
5336 versions of GDB behaved as if "set arm fallback-mode arm".
5338 set arm unwind-secure-frames
5339 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5341 This can trigger security exceptions when unwinding exception stacks.
5343 set disable-randomization
5344 show disable-randomization
5345 Standalone programs run with the virtual address space randomization enabled
5346 by default on some platforms. This option keeps the addresses stable across
5347 multiple debugging sessions.
5351 Control whether other threads are stopped or not when some thread hits
5356 Requests that asynchronous execution is enabled in the target, if available.
5357 In this case, it's possible to resume target in the background, and interact
5358 with GDB while the target is running. "show target-async" displays the
5359 current state of asynchronous execution of the target.
5361 set target-wide-charset
5362 show target-wide-charset
5363 The target-wide-charset is the name of the character set that GDB
5364 uses when printing characters whose type is wchar_t.
5366 set tcp auto-retry (on|off)
5368 set tcp connect-timeout
5369 show tcp connect-timeout
5370 These commands allow GDB to retry failed TCP connections to a remote stub
5371 with a specified timeout period; this is useful if the stub is launched
5372 in parallel with GDB but may not be ready to accept connections immediately.
5374 set libthread-db-search-path
5375 show libthread-db-search-path
5376 Control list of directories which GDB will search for appropriate
5379 set schedule-multiple (on|off)
5380 show schedule-multiple
5381 Allow GDB to resume all threads of all processes or only threads of
5382 the current process.
5386 Use more aggressive caching for accesses to the stack. This improves
5387 performance of remote debugging (particularly backtraces) without
5388 affecting correctness.
5390 set interactive-mode (on|off|auto)
5391 show interactive-mode
5392 Control whether GDB runs in interactive mode (on) or not (off).
5393 When in interactive mode, GDB waits for the user to answer all
5394 queries. Otherwise, GDB does not wait and assumes the default
5395 answer. When set to auto (the default), GDB determines which
5396 mode to use based on the stdin settings.
5401 For program forks, this is replaced by the new more generic `info
5402 inferiors' command. To list checkpoints, you can still use the
5403 `info checkpoints' command, which was an alias for the `info forks'
5407 Replaced by the new `inferior' command. To switch between
5408 checkpoints, you can still use the `restart' command, which was an
5409 alias for the `fork' command.
5412 This is removed, since some targets don't have a notion of
5413 processes. To switch between processes, you can still use the
5414 `inferior' command using GDB's own inferior number.
5417 For program forks, this is replaced by the new more generic `kill
5418 inferior' command. To delete a checkpoint, you can still use the
5419 `delete checkpoint' command, which was an alias for the `delete
5423 For program forks, this is replaced by the new more generic `detach
5424 inferior' command. To detach a checkpoint, you can still use the
5425 `detach checkpoint' command, which was an alias for the `detach
5428 * New native configurations
5430 x86/x86_64 Darwin i[34567]86-*-darwin*
5432 x86_64 MinGW x86_64-*-mingw*
5436 Lattice Mico32 lm32-*
5437 x86 DICOS i[34567]86-*-dicos*
5438 x86_64 DICOS x86_64-*-dicos*
5441 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5442 (mingw32ce) debugging.
5448 These commands were actually not implemented on any target.
5450 *** Changes in GDB 6.8
5452 * New native configurations
5454 NetBSD/hppa hppa*-*netbsd*
5455 Xtensa GNU/Linux xtensa*-*-linux*
5459 NetBSD/hppa hppa*-*-netbsd*
5460 Xtensa GNU/Linux xtensa*-*-linux*
5462 * Change in command line behavior -- corefiles vs. process ids.
5464 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5465 attaching to process NUMBER fails, GDB no longer attempts to open a
5466 core file named NUMBER. Attaching to a program using the -c option
5467 is no longer supported. Instead, use the '-p' or '--pid' options.
5469 * GDB can now be built as a native debugger for debugging Windows x86
5470 (mingw32) Portable Executable (PE) programs.
5472 * Pending breakpoints no longer change their number when their address
5475 * GDB now supports breakpoints with multiple locations,
5476 including breakpoints on C++ constructors, inside C++ templates,
5477 and in inlined functions.
5479 * GDB's ability to debug optimized code has been improved. GDB more
5480 accurately identifies function bodies and lexical blocks that occupy
5481 more than one contiguous range of addresses.
5483 * Target descriptions can now describe registers for PowerPC.
5485 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5486 registers on PowerPC targets.
5488 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5489 targets even when the libthread_db library is not available.
5491 * The GDB remote stub, gdbserver, now supports the new file transfer
5492 commands (remote put, remote get, and remote delete).
5494 * The GDB remote stub, gdbserver, now supports run and attach in
5495 extended-remote mode.
5497 * hppa*64*-*-hpux11* target broken
5498 The debugger is unable to start a program and fails with the following
5499 error: "Error trying to get information about dynamic linker".
5500 The gdb-6.7 release is also affected.
5502 * GDB now supports the --enable-targets= configure option to allow
5503 building a single GDB executable that supports multiple remote
5504 target architectures.
5506 * GDB now supports debugging C and C++ programs which use the
5507 Decimal Floating Point extension. In addition, the PowerPC target
5508 now has a set of pseudo-registers to inspect decimal float values
5509 stored in two consecutive float registers.
5511 * The -break-insert MI command can optionally create pending
5514 * Improved support for debugging Ada
5515 Many improvements to the Ada language support have been made. These
5517 - Better support for Ada2005 interface types
5518 - Improved handling of arrays and slices in general
5519 - Better support for Taft-amendment types
5520 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5522 - Improved command completion in Ada
5525 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5530 set print frame-arguments (all|scalars|none)
5531 show print frame-arguments
5532 The value of this variable can be changed to control which argument
5533 values should be printed by the debugger when displaying a frame.
5538 Transfer files to and from a remote target, and delete remote files.
5545 Transfer files to and from a remote target, and delete remote files.
5547 * New remote packets
5554 Open, close, read, write, and delete files on the remote system.
5557 Attach to an existing process on the remote system, in extended-remote
5561 Run a new process on the remote system, in extended-remote mode.
5563 *** Changes in GDB 6.7
5565 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5566 bfd, libiberty and opcodes, as revealed by static analysis donated by
5567 Coverity, Inc. (http://scan.coverity.com).
5569 * When looking up multiply-defined global symbols, GDB will now prefer the
5570 symbol definition in the current shared library if it was built using the
5571 -Bsymbolic linker option.
5573 * When the Text User Interface (TUI) is not configured, GDB will now
5574 recognize the -tui command-line option and print a message that the TUI
5577 * The GDB remote stub, gdbserver, now has lower overhead for high
5578 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5580 * GDB for MIPS targets now autodetects whether a remote target provides
5581 32-bit or 64-bit register values.
5583 * Support for C++ member pointers has been improved.
5585 * GDB now understands XML target descriptions, which specify the
5586 target's overall architecture. GDB can read a description from
5587 a local file or over the remote serial protocol.
5589 * Vectors of single-byte data use a new integer type which is not
5590 automatically displayed as character or string data.
5592 * The /s format now works with the print command. It displays
5593 arrays of single-byte integers and pointers to single-byte integers
5596 * Target descriptions can now describe target-specific registers,
5597 for architectures which have implemented the support (currently
5598 only ARM, M68K, and MIPS).
5600 * GDB and the GDB remote stub, gdbserver, now support the XScale
5603 * The GDB remote stub, gdbserver, has been updated to support
5604 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5605 has been rewritten to use the standard GDB remote protocol.
5607 * GDB can now step into C++ functions which are called through thunks.
5609 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5611 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5612 layout. It also supports a TextSeg= and DataSeg= response when only
5613 segment base addresses (rather than offsets) are available.
5615 * The /i format now outputs any trailing branch delay slot instructions
5616 immediately following the last instruction within the count specified.
5618 * The GDB remote protocol "T" stop reply packet now supports a
5619 "library" response. Combined with the new "qXfer:libraries:read"
5620 packet, this response allows GDB to debug shared libraries on targets
5621 where the operating system manages the list of loaded libraries (e.g.
5622 Windows and SymbianOS).
5624 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5625 (DLLs) on Windows and Windows CE targets.
5627 * GDB now supports a faster verification that a .debug file matches its binary
5628 according to its build-id signature, if the signature is present.
5634 Enable or disable hardware flow control (RTS/CTS) on the serial port
5635 when debugging using remote targets.
5637 set mem inaccessible-by-default
5638 show mem inaccessible-by-default
5639 If the target supplies a memory map, for instance via the remote
5640 protocol's "qXfer:memory-map:read" packet, setting this variable
5641 prevents GDB from accessing memory outside the memory map. This
5642 is useful for targets with memory mapped registers or which react
5643 badly to accesses of unmapped address space.
5645 set breakpoint auto-hw
5646 show breakpoint auto-hw
5647 If the target supplies a memory map, for instance via the remote
5648 protocol's "qXfer:memory-map:read" packet, setting this variable
5649 lets GDB use hardware breakpoints automatically for memory regions
5650 where it can not use software breakpoints. This covers both the
5651 "break" command and internal breakpoints used for other commands
5652 including "next" and "finish".
5655 catch exception unhandled
5656 Stop the program execution when Ada exceptions are raised.
5659 Stop the program execution when an Ada assertion failed.
5663 Set an alternate system root for target files. This is a more
5664 general version of "set solib-absolute-prefix", which is now
5665 an alias to "set sysroot".
5668 Provide extended SPU facility status information. This set of
5669 commands is available only when debugging the Cell/B.E. SPU
5672 * New native configurations
5674 OpenBSD/sh sh*-*openbsd*
5677 unset tdesc filename
5679 Use the specified local file as an XML target description, and do
5680 not query the target for its built-in description.
5684 OpenBSD/sh sh*-*-openbsd*
5685 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5686 Toshiba Media Processor mep-elf
5688 * New remote packets
5691 Ignore the specified signals; pass them directly to the debugged program
5692 without stopping other threads or reporting them to GDB.
5694 qXfer:features:read:
5695 Read an XML target description from the target, which describes its
5700 Read or write contents of an spufs file on the target system. These
5701 packets are available only on the Cell/B.E. SPU architecture.
5703 qXfer:libraries:read:
5704 Report the loaded shared libraries. Combined with new "T" packet
5705 response, this packet allows GDB to debug shared libraries on
5706 targets where the operating system manages the list of loaded
5707 libraries (e.g. Windows and SymbianOS).
5711 Support for these obsolete configurations has been removed.
5719 i[34567]86-*-lynxos*
5720 i[34567]86-*-netware*
5721 i[34567]86-*-sco3.2v5*
5722 i[34567]86-*-sco3.2v4*
5724 i[34567]86-*-sysv4.2*
5727 i[34567]86-*-unixware2*
5728 i[34567]86-*-unixware*
5737 * Other removed features
5744 Various m68k-only ROM monitors.
5751 Various Renesas ROM monitors and debugging interfaces for SH and
5756 Support for a Macraigor serial interface to on-chip debugging.
5757 GDB does not directly support the newer parallel or USB
5762 A debug information format. The predecessor to DWARF 2 and
5763 DWARF 3, which are still supported.
5765 Support for the HP aCC compiler on HP-UX/PA-RISC
5767 SOM-encapsulated symbolic debugging information, automatic
5768 invocation of pxdb, and the aCC custom C++ ABI. This does not
5769 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5770 with aCC can still be debugged on an assembly level.
5772 MIPS ".pdr" sections
5774 A MIPS-specific format used to describe stack frame layout
5775 in debugging information.
5779 GDB could work with an older version of Guile to debug
5780 the interpreter and Scheme programs running in it.
5782 set mips stack-arg-size
5783 set mips saved-gpreg-size
5785 Use "set mips abi" to control parameter passing for MIPS.
5787 *** Changes in GDB 6.6
5792 Cell Broadband Engine SPU spu-elf
5794 * GDB can now be configured as a cross-debugger targeting native Windows
5795 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5796 running on a Windows system over TCP/IP to debug Windows programs.
5798 * The GDB remote stub, gdbserver, has been updated to support Windows and
5799 Cygwin debugging. Both single-threaded and multi-threaded programs are
5802 * The "set trust-readonly-sections" command works again. This command was
5803 broken in GDB 6.3, 6.4, and 6.5.
5805 * The "load" command now supports writing to flash memory, if the remote
5806 stub provides the required support.
5808 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5809 longer requires symbolic debug information (e.g. DWARF-2).
5814 unset substitute-path
5815 show substitute-path
5816 Manage a list of substitution rules that GDB uses to rewrite the name
5817 of the directories where the sources are located. This can be useful
5818 for instance when the sources were moved to a different location
5819 between compilation and debugging.
5823 Print each CLI command as it is executed. Each command is prefixed with
5824 a number of `+' symbols representing the nesting depth.
5825 The source command now has a `-v' option to enable the same feature.
5829 The ARM Demon monitor support (RDP protocol, "target rdp").
5831 Kernel Object Display, an embedded debugging feature which only worked with
5832 an obsolete version of Cisco IOS.
5834 The 'set download-write-size' and 'show download-write-size' commands.
5836 * New remote packets
5839 Tell a stub about GDB client features, and request remote target features.
5840 The first feature implemented is PacketSize, which allows the target to
5841 specify the size of packets it can handle - to minimize the number of
5842 packets required and improve performance when connected to a remote
5846 Fetch an OS auxilliary vector from the remote stub. This packet is a
5847 more efficient replacement for qPart:auxv:read.
5849 qXfer:memory-map:read:
5850 Fetch a memory map from the remote stub, including information about
5851 RAM, ROM, and flash memory devices.
5856 Erase and program a flash memory device.
5858 * Removed remote packets
5861 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5862 used it, and only gdbserver implemented it.
5864 *** Changes in GDB 6.5
5868 Renesas M32C/M16C m32c-elf
5870 Morpho Technologies ms1 ms1-elf
5874 init-if-undefined Initialize a convenience variable, but
5875 only if it doesn't already have a value.
5877 The following commands are presently only implemented for native GNU/Linux:
5879 checkpoint Save a snapshot of the program state.
5881 restart <n> Return the program state to a
5882 previously saved state.
5884 info checkpoints List currently saved checkpoints.
5886 delete-checkpoint <n> Delete a previously saved checkpoint.
5888 set|show detach-on-fork Tell gdb whether to detach from a newly
5889 forked process, or to keep debugging it.
5891 info forks List forks of the user program that
5892 are available to be debugged.
5894 fork <n> Switch to debugging one of several
5895 forks of the user program that are
5896 available to be debugged.
5898 delete-fork <n> Delete a fork from the list of forks
5899 that are available to be debugged (and
5900 kill the forked process).
5902 detach-fork <n> Delete a fork from the list of forks
5903 that are available to be debugged (and
5904 allow the process to continue).
5908 Morpho Technologies ms2 ms1-elf
5910 * Improved Windows host support
5912 GDB now builds as a cross debugger hosted on i686-mingw32, including
5913 native console support, and remote communications using either
5914 network sockets or serial ports.
5916 * Improved Modula-2 language support
5918 GDB can now print most types in the Modula-2 syntax. This includes:
5919 basic types, set types, record types, enumerated types, range types,
5920 pointer types and ARRAY types. Procedure var parameters are correctly
5921 printed and hexadecimal addresses and character constants are also
5922 written in the Modula-2 syntax. Best results can be obtained by using
5923 GNU Modula-2 together with the -gdwarf-2 command line option.
5927 The ARM rdi-share module.
5929 The Netware NLM debug server.
5931 *** Changes in GDB 6.4
5933 * New native configurations
5935 OpenBSD/arm arm*-*-openbsd*
5936 OpenBSD/mips64 mips64-*-openbsd*
5940 Morpho Technologies ms1 ms1-elf
5942 * New command line options
5944 --batch-silent As for --batch, but totally silent.
5945 --return-child-result The debugger will exist with the same value
5946 the child (debugged) program exited with.
5947 --eval-command COMMAND, -ex COMMAND
5948 Execute a single GDB CLI command. This may be
5949 specified multiple times and in conjunction
5950 with the --command (-x) option.
5952 * Deprecated commands removed
5954 The following commands, that were deprecated in 2000, have been
5958 set|show arm disassembly-flavor set|show arm disassembler
5959 othernames set arm disassembler
5960 set|show remotedebug set|show debug remote
5961 set|show archdebug set|show debug arch
5962 set|show eventdebug set|show debug event
5965 * New BSD user-level threads support
5967 It is now possible to debug programs using the user-level threads
5968 library on OpenBSD and FreeBSD. Currently supported (target)
5971 FreeBSD/amd64 x86_64-*-freebsd*
5972 FreeBSD/i386 i386-*-freebsd*
5973 OpenBSD/i386 i386-*-openbsd*
5975 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5976 are not yet supported.
5978 * New support for Matsushita MN10300 w/sim added
5979 (Work in progress). mn10300-elf.
5981 * REMOVED configurations and files
5983 VxWorks and the XDR protocol *-*-vxworks
5984 Motorola MCORE mcore-*-*
5985 National Semiconductor NS32000 ns32k-*-*
5987 * New "set print array-indexes" command
5989 After turning this setting "on", GDB prints the index of each element
5990 when displaying arrays. The default is "off" to preserve the previous
5993 * VAX floating point support
5995 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5997 * User-defined command support
5999 In addition to using $arg0..$arg9 for argument passing, it is now possible
6000 to use $argc to determine now many arguments have been passed. See the
6001 section on user-defined commands in the user manual for more information.
6003 *** Changes in GDB 6.3:
6005 * New command line option
6007 GDB now accepts -l followed by a number to set the timeout for remote
6010 * GDB works with GCC -feliminate-dwarf2-dups
6012 GDB now supports a more compact representation of DWARF-2 debug
6013 information using DW_FORM_ref_addr references. These are produced
6014 by GCC with the option -feliminate-dwarf2-dups and also by some
6015 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6016 to use -feliminate-dwarf2-dups.
6018 * Internationalization
6020 When supported by the host system, GDB will be built with
6021 internationalization (libintl). The task of marking up the sources is
6022 continued, we're looking forward to our first translation.
6026 Initial support for debugging programs compiled with the GNAT
6027 implementation of the Ada programming language has been integrated
6028 into GDB. In this release, support is limited to expression evaluation.
6030 * New native configurations
6032 GNU/Linux/m32r m32r-*-linux-gnu
6036 GDB's remote protocol now includes support for the 'p' packet. This
6037 packet is used to fetch individual registers from a remote inferior.
6039 * END-OF-LIFE registers[] compatibility module
6041 GDB's internal register infrastructure has been completely rewritten.
6042 The new infrastructure making possible the implementation of key new
6043 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6046 GDB 6.3 will be the last release to include the registers[]
6047 compatibility module that allowed out-of-date configurations to
6048 continue to work. This change directly impacts the following
6058 powerpc bdm protocol
6060 Unless there is activity to revive these configurations, they will be
6061 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6063 * OBSOLETE configurations and files
6065 Configurations that have been declared obsolete in this release have
6066 been commented out. Unless there is activity to revive these
6067 configurations, the next release of GDB will have their sources
6068 permanently REMOVED.
6077 *** Changes in GDB 6.2.1:
6079 * MIPS `break main; run' gave an heuristic-fence-post warning
6081 When attempting to run even a simple program, a warning about
6082 heuristic-fence-post being hit would be reported. This problem has
6085 * MIPS IRIX 'long double' crashed GDB
6087 When examining a long double variable, GDB would get a segmentation
6088 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6089 IRIX long double values).
6093 A bug in the VAX stack code was causing problems with the "next"
6094 command. This problem has been fixed.
6096 *** Changes in GDB 6.2:
6098 * Fix for ``many threads''
6100 On GNU/Linux systems that use the NPTL threads library, a program
6101 rapidly creating and deleting threads would confuse GDB leading to the
6104 ptrace: No such process.
6105 thread_db_get_info: cannot get thread info: generic error
6107 This problem has been fixed.
6109 * "-async" and "-noasync" options removed.
6111 Support for the broken "-noasync" option has been removed (it caused
6114 * New ``start'' command.
6116 This command runs the program until the beginning of the main procedure.
6118 * New BSD Kernel Data Access Library (libkvm) interface
6120 Using ``target kvm'' it is now possible to debug kernel core dumps and
6121 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6122 platforms. Currently supported (native-only) configurations are:
6124 FreeBSD/amd64 x86_64-*-freebsd*
6125 FreeBSD/i386 i?86-*-freebsd*
6126 NetBSD/i386 i?86-*-netbsd*
6127 NetBSD/m68k m68*-*-netbsd*
6128 NetBSD/sparc sparc-*-netbsd*
6129 OpenBSD/amd64 x86_64-*-openbsd*
6130 OpenBSD/i386 i?86-*-openbsd*
6131 OpenBSD/m68k m68*-openbsd*
6132 OpenBSD/sparc sparc-*-openbsd*
6134 * Signal trampoline code overhauled
6136 Many generic problems with GDB's signal handling code have been fixed.
6137 These include: backtraces through non-contiguous stacks; recognition
6138 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6139 call; backtrace through a signal trampoline; step into and out of
6140 signal handlers; and single-stepping in the signal trampoline.
6142 Please note that kernel bugs are a limiting factor here. These
6143 features have been shown to work on an s390 GNU/Linux system that
6144 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6146 * Cygwin support for DWARF 2 added.
6148 * New native configurations
6150 GNU/Linux/hppa hppa*-*-linux*
6151 OpenBSD/hppa hppa*-*-openbsd*
6152 OpenBSD/m68k m68*-*-openbsd*
6153 OpenBSD/m88k m88*-*-openbsd*
6154 OpenBSD/powerpc powerpc-*-openbsd*
6155 NetBSD/vax vax-*-netbsd*
6156 OpenBSD/vax vax-*-openbsd*
6158 * END-OF-LIFE frame compatibility module
6160 GDB's internal frame infrastructure has been completely rewritten.
6161 The new infrastructure making it possible to support key new features
6162 including DWARF 2 Call Frame Information. To aid in the task of
6163 migrating old configurations to this new infrastructure, a
6164 compatibility module, that allowed old configurations to continue to
6165 work, was also included.
6167 GDB 6.2 will be the last release to include this frame compatibility
6168 module. This change directly impacts the following configurations:
6178 Unless there is activity to revive these configurations, they will be
6179 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6181 * REMOVED configurations and files
6183 Sun 3, running SunOS 3 m68*-*-sunos3*
6184 Sun 3, running SunOS 4 m68*-*-sunos4*
6185 Sun 2, running SunOS 3 m68000-*-sunos3*
6186 Sun 2, running SunOS 4 m68000-*-sunos4*
6187 Motorola 680x0 running LynxOS m68*-*-lynxos*
6188 AT&T 3b1/Unix pc m68*-att-*
6189 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6190 decstation mips-dec-* mips-little-*
6191 riscos mips-*-riscos* mips-*-sysv*
6192 sonymips mips-sony-*
6193 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6195 *** Changes in GDB 6.1.1:
6197 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6199 The TUI (Text-mode User Interface) is now built as part of a default
6200 GDB configuration. It is enabled by either selecting the TUI with the
6201 command line option "-i=tui" or by running the separate "gdbtui"
6202 program. For more information on the TUI, see the manual "Debugging
6205 * Pending breakpoint support (also included in GDB 6.1)
6207 Support has been added to allow you to specify breakpoints in shared
6208 libraries that have not yet been loaded. If a breakpoint location
6209 cannot be found, and the "breakpoint pending" option is set to auto,
6210 GDB queries you if you wish to make the breakpoint pending on a future
6211 shared-library load. If and when GDB resolves the breakpoint symbol,
6212 the pending breakpoint is removed as one or more regular breakpoints
6215 Pending breakpoints are very useful for GCJ Java debugging.
6217 * Fixed ISO-C build problems
6219 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6220 non ISO-C code that stopped them being built using a more strict ISO-C
6221 compiler (e.g., IBM's C compiler).
6223 * Fixed build problem on IRIX 5
6225 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6226 wasn't able to compile compile on an IRIX 5 system.
6228 * Added execute permission to gdb/gdbserver/configure
6230 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6231 permission. This bug would cause configure to fail on a number of
6232 systems (Solaris, IRIX). Ref: server/519.
6234 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6236 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6237 has been updated to use constant array sizes.
6239 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6241 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6242 its generated DWARF Call Frame Info. This encoding was causing GDB to
6243 panic, that panic has been fixed. Ref: gdb/1628.
6245 * Fixed a problem when examining parameters in shared library code.
6247 When examining parameters in optimized shared library code generated
6248 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6249 not available''. GDB now correctly displays the variable's value.
6251 *** Changes in GDB 6.1:
6253 * Removed --with-mmalloc
6255 Support for the mmalloc memory manager has been removed, as it
6256 conflicted with the internal gdb byte cache.
6258 * Changes in AMD64 configurations
6260 The AMD64 target now includes the %cs and %ss registers. As a result
6261 the AMD64 remote protocol has changed; this affects the floating-point
6262 and SSE registers. If you rely on those registers for your debugging,
6263 you should upgrade gdbserver on the remote side.
6265 * Revised SPARC target
6267 The SPARC target has been completely revised, incorporating the
6268 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6269 support for LynxOS and SunOS 4 has been dropped. Calling functions
6270 from within GDB on operating systems with a non-executable stack
6271 (Solaris, OpenBSD) now works.
6275 GDB has a new C++ demangler which does a better job on the mangled
6276 names generated by current versions of g++. It also runs faster, so
6277 with this and other changes gdb should now start faster on large C++
6280 * DWARF 2 Location Expressions
6282 GDB support for location expressions has been extended to support function
6283 arguments and frame bases. Older versions of GDB could crash when they
6286 * C++ nested types and namespaces
6288 GDB's support for nested types and namespaces in C++ has been
6289 improved, especially if you use the DWARF 2 debugging format. (This
6290 is the default for recent versions of GCC on most platforms.)
6291 Specifically, if you have a class "Inner" defined within a class or
6292 namespace "Outer", then GDB realizes that the class's name is
6293 "Outer::Inner", not simply "Inner". This should greatly reduce the
6294 frequency of complaints about not finding RTTI symbols. In addition,
6295 if you are stopped at inside of a function defined within a namespace,
6296 GDB modifies its name lookup accordingly.
6298 * New native configurations
6300 NetBSD/amd64 x86_64-*-netbsd*
6301 OpenBSD/amd64 x86_64-*-openbsd*
6302 OpenBSD/alpha alpha*-*-openbsd*
6303 OpenBSD/sparc sparc-*-openbsd*
6304 OpenBSD/sparc64 sparc64-*-openbsd*
6306 * New debugging protocols
6308 M32R with SDI protocol m32r-*-elf*
6310 * "set prompt-escape-char" command deleted.
6312 The command "set prompt-escape-char" has been deleted. This command,
6313 and its very obscure effect on GDB's prompt, was never documented,
6314 tested, nor mentioned in the NEWS file.
6316 * OBSOLETE configurations and files
6318 Configurations that have been declared obsolete in this release have
6319 been commented out. Unless there is activity to revive these
6320 configurations, the next release of GDB will have their sources
6321 permanently REMOVED.
6323 Sun 3, running SunOS 3 m68*-*-sunos3*
6324 Sun 3, running SunOS 4 m68*-*-sunos4*
6325 Sun 2, running SunOS 3 m68000-*-sunos3*
6326 Sun 2, running SunOS 4 m68000-*-sunos4*
6327 Motorola 680x0 running LynxOS m68*-*-lynxos*
6328 AT&T 3b1/Unix pc m68*-att-*
6329 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6330 decstation mips-dec-* mips-little-*
6331 riscos mips-*-riscos* mips-*-sysv*
6332 sonymips mips-sony-*
6333 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6335 * REMOVED configurations and files
6337 SGI Irix-4.x mips-sgi-irix4 or iris4
6338 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6339 Z8000 simulator z8k-zilog-none or z8ksim
6340 Matsushita MN10200 w/simulator mn10200-*-*
6341 H8/500 simulator h8500-hitachi-hms or h8500hms
6342 HP/PA running BSD hppa*-*-bsd*
6343 HP/PA running OSF/1 hppa*-*-osf*
6344 HP/PA Pro target hppa*-*-pro*
6345 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6346 386BSD i[3456]86-*-bsd*
6347 Sequent family i[3456]86-sequent-sysv4*
6348 i[3456]86-sequent-sysv*
6349 i[3456]86-sequent-bsd*
6350 SPARC running LynxOS sparc-*-lynxos*
6351 SPARC running SunOS 4 sparc-*-sunos4*
6352 Tsqware Sparclet sparclet-*-*
6353 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6355 *** Changes in GDB 6.0:
6359 Support for debugging the Objective-C programming language has been
6360 integrated into GDB.
6362 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6364 DWARF 2's Call Frame Information makes available compiler generated
6365 information that more exactly describes the program's run-time stack.
6366 By using this information, GDB is able to provide more robust stack
6369 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6370 have been updated to use a new backtrace mechanism which includes
6371 DWARF 2 CFI support.
6375 GDB's remote protocol has been extended to include support for hosted
6376 file I/O (where the remote target uses GDB's file system). See GDB's
6377 remote protocol documentation for details.
6379 * All targets using the new architecture framework.
6381 All of GDB's targets have been updated to use the new internal
6382 architecture framework. The way is now open for future GDB releases
6383 to include cross-architecture native debugging support (i386 on amd64,
6386 * GNU/Linux's Thread Local Storage (TLS)
6388 GDB now includes support for for the GNU/Linux implementation of
6389 per-thread variables.
6391 * GNU/Linux's Native POSIX Thread Library (NPTL)
6393 GDB's thread code has been updated to work with either the new
6394 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6396 * Separate debug info.
6398 GDB, in conjunction with BINUTILS, now supports a mechanism for
6399 automatically loading debug information from a separate file. Instead
6400 of shipping full debug and non-debug versions of system libraries,
6401 system integrators can now instead ship just the stripped libraries
6402 and optional debug files.
6404 * DWARF 2 Location Expressions
6406 DWARF 2 Location Expressions allow the compiler to more completely
6407 describe the location of variables (even in optimized code) to the
6410 GDB now includes preliminary support for location expressions (support
6411 for DW_OP_piece is still missing).
6415 A number of long standing bugs that caused GDB to die while starting a
6416 Java application have been fixed. GDB's Java support is now
6417 considered "useable".
6419 * GNU/Linux support for fork, vfork, and exec.
6421 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6422 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6425 * GDB supports logging output to a file
6427 There are two new commands, "set logging" and "show logging", which can be
6428 used to capture GDB's output to a file.
6430 * The meaning of "detach" has changed for gdbserver
6432 The "detach" command will now resume the application, as documented. To
6433 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6436 * d10v, m68hc11 `regs' command deprecated
6438 The `info registers' command has been updated so that it displays the
6439 registers using a format identical to the old `regs' command.
6443 A new command, "maint set profile on/off", has been added. This command can
6444 be used to enable or disable profiling while running GDB, to profile a
6445 session or a set of commands. In addition there is a new configure switch,
6446 "--enable-profiling", which will cause GDB to be compiled with profiling
6447 data, for more informative profiling results.
6449 * Default MI syntax changed to "mi2".
6451 The default MI (machine interface) syntax, enabled by the command line
6452 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6453 "mi1", can be enabled by specifying the option "-i=mi1".
6455 Support for the original "mi0" syntax (included in GDB 5.0) has been
6458 Fix for gdb/192: removed extraneous space when displaying frame level.
6459 Fix for gdb/672: update changelist is now output in mi list format.
6460 Fix for gdb/702: a -var-assign that updates the value now shows up
6461 in a subsequent -var-update.
6463 * New native configurations.
6465 FreeBSD/amd64 x86_64-*-freebsd*
6467 * Multi-arched targets.
6469 HP/PA HPUX11 hppa*-*-hpux*
6470 Renesas M32R/D w/simulator m32r-*-elf*
6472 * OBSOLETE configurations and files
6474 Configurations that have been declared obsolete in this release have
6475 been commented out. Unless there is activity to revive these
6476 configurations, the next release of GDB will have their sources
6477 permanently REMOVED.
6479 Z8000 simulator z8k-zilog-none or z8ksim
6480 Matsushita MN10200 w/simulator mn10200-*-*
6481 H8/500 simulator h8500-hitachi-hms or h8500hms
6482 HP/PA running BSD hppa*-*-bsd*
6483 HP/PA running OSF/1 hppa*-*-osf*
6484 HP/PA Pro target hppa*-*-pro*
6485 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6486 Sequent family i[3456]86-sequent-sysv4*
6487 i[3456]86-sequent-sysv*
6488 i[3456]86-sequent-bsd*
6489 Tsqware Sparclet sparclet-*-*
6490 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6492 * REMOVED configurations and files
6495 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6496 IBM AIX PS/2 i[3456]86-*-aix
6497 i386 running Mach 3.0 i[3456]86-*-mach3*
6498 i386 running Mach i[3456]86-*-mach*
6499 i386 running OSF/1 i[3456]86-*osf1mk*
6500 HP/Apollo 68k Family m68*-apollo*-sysv*,
6502 m68*-hp-bsd*, m68*-hp-hpux*
6503 Argonaut Risc Chip (ARC) arc-*-*
6504 Mitsubishi D30V d30v-*-*
6505 Fujitsu FR30 fr30-*-elf*
6506 OS/9000 i[34]86-*-os9k
6507 I960 with MON960 i960-*-coff
6509 * MIPS $fp behavior changed
6511 The convenience variable $fp, for the MIPS, now consistently returns
6512 the address of the current frame's base. Previously, depending on the
6513 context, $fp could refer to either $sp or the current frame's base
6514 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6515 The GNU Source-Level Debugger''.
6517 *** Changes in GDB 5.3:
6519 * GNU/Linux shared library multi-threaded performance improved.
6521 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6522 `/proc', in preference to `ptrace' for memory reads. This may result
6523 in an improvement in the start-up time of multi-threaded, shared
6524 library applications when run under GDB. One GDB user writes: ``loads
6525 shared libs like mad''.
6527 * ``gdbserver'' now supports multi-threaded applications on some targets
6529 Support for debugging multi-threaded applications which use
6530 the GNU/Linux LinuxThreads package has been added for
6531 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6532 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6534 * GDB now supports C/C++ preprocessor macros.
6536 GDB now expands preprocessor macro invocations in C/C++ expressions,
6537 and provides various commands for showing macro definitions and how
6540 The new command `macro expand EXPRESSION' expands any macro
6541 invocations in expression, and shows the result.
6543 The new command `show macro MACRO-NAME' shows the definition of the
6544 macro named MACRO-NAME, and where it was defined.
6546 Most compilers don't include information about macros in the debugging
6547 information by default. In GCC 3.1, for example, you need to compile
6548 your program with the options `-gdwarf-2 -g3'. If the macro
6549 information is present in the executable, GDB will read it.
6551 * Multi-arched targets.
6553 DEC Alpha (partial) alpha*-*-*
6554 DEC VAX (partial) vax-*-*
6556 National Semiconductor NS32000 (partial) ns32k-*-*
6557 Motorola 68000 (partial) m68k-*-*
6558 Motorola MCORE mcore-*-*
6562 Fujitsu FRV architecture added by Red Hat frv*-*-*
6565 * New native configurations
6567 Alpha NetBSD alpha*-*-netbsd*
6568 SH NetBSD sh*-*-netbsdelf*
6569 MIPS NetBSD mips*-*-netbsd*
6570 UltraSPARC NetBSD sparc64-*-netbsd*
6572 * OBSOLETE configurations and files
6574 Configurations that have been declared obsolete in this release have
6575 been commented out. Unless there is activity to revive these
6576 configurations, the next release of GDB will have their sources
6577 permanently REMOVED.
6579 Mitsubishi D30V d30v-*-*
6580 OS/9000 i[34]86-*-os9k
6581 IBM AIX PS/2 i[3456]86-*-aix
6582 Fujitsu FR30 fr30-*-elf*
6583 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6584 Argonaut Risc Chip (ARC) arc-*-*
6585 i386 running Mach 3.0 i[3456]86-*-mach3*
6586 i386 running Mach i[3456]86-*-mach*
6587 i386 running OSF/1 i[3456]86-*osf1mk*
6588 HP/Apollo 68k Family m68*-apollo*-sysv*,
6590 m68*-hp-bsd*, m68*-hp-hpux*
6591 I960 with MON960 i960-*-coff
6593 * OBSOLETE languages
6595 CHILL, a Pascal like language used by telecommunications companies.
6597 * REMOVED configurations and files
6599 AMD 29k family via UDI a29k-amd-udi, udi29k
6600 A29K VxWorks a29k-*-vxworks
6601 AMD 29000 embedded, using EBMON a29k-none-none
6602 AMD 29000 embedded with COFF a29k-none-coff
6603 AMD 29000 embedded with a.out a29k-none-aout
6605 testsuite/gdb.hp/gdb.threads-hp/ directory
6607 * New command "set max-user-call-depth <nnn>"
6609 This command allows the user to limit the call depth of user-defined
6610 commands. The default is 1024.
6612 * Changes in FreeBSD/i386 native debugging.
6614 Support for the "generate-core-file" has been added.
6616 * New commands "dump", "append", and "restore".
6618 These commands allow data to be copied from target memory
6619 to a bfd-format or binary file (dump and append), and back
6620 from a file into memory (restore).
6622 * Improved "next/step" support on multi-processor Alpha Tru64.
6624 The previous single-step mechanism could cause unpredictable problems,
6625 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6626 of a software single-step mechanism prevents this.
6628 *** Changes in GDB 5.2.1:
6636 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6637 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6638 Fix, by Joel Brobecker imported from mainline.
6640 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6641 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6642 Fix, by Fred Fish, imported from mainline.
6644 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6645 Surprisingly enough, it works now.
6646 By Michal Ludvig, imported from mainline.
6648 i386 hardware watchpoint support:
6649 avoid misses on second run for some targets.
6650 By Pierre Muller, imported from mainline.
6652 *** Changes in GDB 5.2:
6654 * New command "set trust-readonly-sections on[off]".
6656 This command is a hint that tells gdb that read-only sections
6657 really are read-only (ie. that their contents will not change).
6658 In this mode, gdb will go to the object file rather than the
6659 target to read memory from read-only sections (such as ".text").
6660 This can be a significant performance improvement on some
6661 (notably embedded) targets.
6663 * New command "generate-core-file" (or "gcore").
6665 This new gdb command allows the user to drop a core file of the child
6666 process state at any time. So far it's been implemented only for
6667 GNU/Linux and Solaris, but should be relatively easily ported to other
6668 hosts. Argument is core file name (defaults to core.<pid>).
6670 * New command line option
6672 GDB now accepts --pid or -p followed by a process id.
6674 * Change in command line behavior -- corefiles vs. process ids.
6676 There is a subtle behavior in the way in which GDB handles
6677 command line arguments. The first non-flag argument is always
6678 a program to debug, but the second non-flag argument may either
6679 be a corefile or a process id. Previously, GDB would attempt to
6680 open the second argument as a corefile, and if that failed, would
6681 issue a superfluous error message and then attempt to attach it as
6682 a process. Now, if the second argument begins with a non-digit,
6683 it will be treated as a corefile. If it begins with a digit,
6684 GDB will attempt to attach it as a process, and if no such process
6685 is found, will then attempt to open it as a corefile.
6687 * Changes in ARM configurations.
6689 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6690 configuration is fully multi-arch.
6692 * New native configurations
6694 ARM NetBSD arm*-*-netbsd*
6695 x86 OpenBSD i[3456]86-*-openbsd*
6696 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6697 Sparc64 running FreeBSD sparc64-*-freebsd*
6701 Sanyo XStormy16 xstormy16-elf
6703 * OBSOLETE configurations and files
6705 Configurations that have been declared obsolete in this release have
6706 been commented out. Unless there is activity to revive these
6707 configurations, the next release of GDB will have their sources
6708 permanently REMOVED.
6710 AMD 29k family via UDI a29k-amd-udi, udi29k
6711 A29K VxWorks a29k-*-vxworks
6712 AMD 29000 embedded, using EBMON a29k-none-none
6713 AMD 29000 embedded with COFF a29k-none-coff
6714 AMD 29000 embedded with a.out a29k-none-aout
6716 testsuite/gdb.hp/gdb.threads-hp/ directory
6718 * REMOVED configurations and files
6720 TI TMS320C80 tic80-*-*
6722 PowerPC Solaris powerpcle-*-solaris*
6723 PowerPC Windows NT powerpcle-*-cygwin32
6724 PowerPC Netware powerpc-*-netware*
6725 Harris/CXUX m88k m88*-harris-cxux*
6726 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6727 ns32k-utek-sysv* ns32k-utek-*
6728 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6729 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6730 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6731 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6732 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6734 * Changes to command line processing
6736 The new `--args' feature can be used to specify command-line arguments
6737 for the inferior from gdb's command line.
6739 * Changes to key bindings
6741 There is a new `operate-and-get-next' function bound to `C-o'.
6743 *** Changes in GDB 5.1.1
6745 Fix compile problem on DJGPP.
6747 Fix a problem with floating-point registers on the i386 being
6750 Fix to stop GDB crashing on .debug_str debug info.
6752 Numerous documentation fixes.
6754 Numerous testsuite fixes.
6756 *** Changes in GDB 5.1:
6758 * New native configurations
6760 Alpha FreeBSD alpha*-*-freebsd*
6761 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6762 MIPS GNU/Linux mips*-*-linux*
6763 MIPS SGI Irix 6.x mips*-sgi-irix6*
6764 ia64 AIX ia64-*-aix*
6765 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6769 Motorola 68HC11 and 68HC12 m68hc11-elf
6771 UltraSparc running GNU/Linux sparc64-*-linux*
6773 * OBSOLETE configurations and files
6775 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6776 Harris/CXUX m88k m88*-harris-cxux*
6777 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6778 ns32k-utek-sysv* ns32k-utek-*
6779 TI TMS320C80 tic80-*-*
6781 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6782 PowerPC Solaris powerpcle-*-solaris*
6783 PowerPC Windows NT powerpcle-*-cygwin32
6784 PowerPC Netware powerpc-*-netware*
6785 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6786 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6787 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6788 Apple Macintosh (MPW) host N/A
6790 stuff.c (Program to stuff files into a specially prepared space in kdb)
6791 kdb-start.c (Main loop for the standalone kernel debugger)
6793 Configurations that have been declared obsolete in this release have
6794 been commented out. Unless there is activity to revive these
6795 configurations, the next release of GDB will have their sources
6796 permanently REMOVED.
6798 * REMOVED configurations and files
6800 Altos 3068 m68*-altos-*
6801 Convex c1-*-*, c2-*-*
6803 ARM RISCix arm-*-* (as host)
6807 * GDB has been converted to ISO C.
6809 GDB's source code has been converted to ISO C. In particular, the
6810 sources are fully protoized, and rely on standard headers being
6815 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6817 * The MI enabled by default.
6819 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6820 revised and enabled by default. Packages which use GDB as a debugging
6821 engine behind a UI or another front end are encouraged to switch to
6822 using the GDB/MI interface, instead of the old annotations interface
6823 which is now deprecated.
6825 * Support for debugging Pascal programs.
6827 GDB now includes support for debugging Pascal programs. The following
6828 main features are supported:
6830 - Pascal-specific data types such as sets;
6832 - automatic recognition of Pascal sources based on file-name
6835 - Pascal-style display of data types, variables, and functions;
6837 - a Pascal expression parser.
6839 However, some important features are not yet supported.
6841 - Pascal string operations are not supported at all;
6843 - there are some problems with boolean types;
6845 - Pascal type hexadecimal constants are not supported
6846 because they conflict with the internal variables format;
6848 - support for Pascal objects and classes is not full yet;
6850 - unlike Pascal, GDB is case-sensitive for symbol names.
6852 * Changes in completion.
6854 Commands such as `shell', `run' and `set args', which pass arguments
6855 to inferior programs, now complete on file names, similar to what
6856 users expect at the shell prompt.
6858 Commands which accept locations, such as `disassemble', `print',
6859 `breakpoint', `until', etc. now complete on filenames as well as
6860 program symbols. Thus, if you type "break foob TAB", and the source
6861 files linked into the programs include `foobar.c', that file name will
6862 be one of the candidates for completion. However, file names are not
6863 considered for completion after you typed a colon that delimits a file
6864 name from a name of a function in that file, as in "break foo.c:bar".
6866 `set demangle-style' completes on available demangling styles.
6868 * New platform-independent commands:
6870 It is now possible to define a post-hook for a command as well as a
6871 hook that runs before the command. For more details, see the
6872 documentation of `hookpost' in the GDB manual.
6874 * Changes in GNU/Linux native debugging.
6876 Support for debugging multi-threaded programs has been completely
6877 revised for all platforms except m68k and sparc. You can now debug as
6878 many threads as your system allows you to have.
6880 Attach/detach is supported for multi-threaded programs.
6882 Support for SSE registers was added for x86. This doesn't work for
6883 multi-threaded programs though.
6885 * Changes in MIPS configurations.
6887 Multi-arch support is enabled for all MIPS configurations.
6889 GDB can now be built as native debugger on SGI Irix 6.x systems for
6890 debugging n32 executables. (Debugging 64-bit executables is not yet
6893 * Unified support for hardware watchpoints in all x86 configurations.
6895 Most (if not all) native x86 configurations support hardware-assisted
6896 breakpoints and watchpoints in a unified manner. This support
6897 implements debug register sharing between watchpoints, which allows to
6898 put a virtually infinite number of watchpoints on the same address,
6899 and also supports watching regions up to 16 bytes with several debug
6902 The new maintenance command `maintenance show-debug-regs' toggles
6903 debugging print-outs in functions that insert, remove, and test
6904 watchpoints and hardware breakpoints.
6906 * Changes in the DJGPP native configuration.
6908 New command ``info dos sysinfo'' displays assorted information about
6909 the CPU, OS, memory, and DPMI server.
6911 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6912 display information about segment descriptors stored in GDT, LDT, and
6915 New commands ``info dos pde'' and ``info dos pte'' display entries
6916 from Page Directory and Page Tables (for now works with CWSDPMI only).
6917 New command ``info dos address-pte'' displays the Page Table entry for
6918 a given linear address.
6920 GDB can now pass command lines longer than 126 characters to the
6921 program being debugged (requires an update to the libdbg.a library
6922 which is part of the DJGPP development kit).
6924 DWARF2 debug info is now supported.
6926 It is now possible to `step' and `next' through calls to `longjmp'.
6928 * Changes in documentation.
6930 All GDB documentation was converted to GFDL, the GNU Free
6931 Documentation License.
6933 Tracepoints-related commands are now fully documented in the GDB
6936 TUI, the Text-mode User Interface, is now documented in the manual.
6938 Tracepoints-related commands are now fully documented in the GDB
6941 The "GDB Internals" manual now has an index. It also includes
6942 documentation of `ui_out' functions, GDB coding standards, x86
6943 hardware watchpoints, and memory region attributes.
6945 * GDB's version number moved to ``version.in''
6947 The Makefile variable VERSION has been replaced by the file
6948 ``version.in''. People creating GDB distributions should update the
6949 contents of this file.
6953 GUD support is now a standard part of the EMACS distribution.
6955 *** Changes in GDB 5.0:
6957 * Improved support for debugging FP programs on x86 targets
6959 Unified and much-improved support for debugging floating-point
6960 programs on all x86 targets. In particular, ``info float'' now
6961 displays the FP registers in the same format on all x86 targets, with
6962 greater level of detail.
6964 * Improvements and bugfixes in hardware-assisted watchpoints
6966 It is now possible to watch array elements, struct members, and
6967 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6968 on x86 targets no longer erroneously trigger when the address is
6971 * Improvements in the native DJGPP version of GDB
6973 The distribution now includes all the scripts and auxiliary files
6974 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6975 machines ``out of the box''.
6977 The DJGPP version can now debug programs that use signals. It is
6978 possible to catch signals that happened in the debuggee, deliver
6979 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6980 would kill the program being debugged.) Programs that hook hardware
6981 interrupts (keyboard, timer, etc.) can also be debugged.
6983 It is now possible to debug DJGPP programs that redirect their
6984 standard handles or switch them to raw (as opposed to cooked) mode, or
6985 even close them. The command ``run < foo > bar'' works as expected,
6986 and ``info terminal'' reports useful information about the debuggee's
6987 terminal, including raw/cooked mode, redirection, etc.
6989 The DJGPP version now uses termios functions for console I/O, which
6990 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6993 DOS-style file names with drive letters are now fully supported by
6996 It is now possible to debug DJGPP programs that switch their working
6997 directory. It is also possible to rerun the debuggee any number of
6998 times without restarting GDB; thus, you can use the same setup,
6999 breakpoints, etc. for many debugging sessions.
7001 * New native configurations
7003 ARM GNU/Linux arm*-*-linux*
7004 PowerPC GNU/Linux powerpc-*-linux*
7008 Motorola MCore mcore-*-*
7009 x86 VxWorks i[3456]86-*-vxworks*
7010 PowerPC VxWorks powerpc-*-vxworks*
7011 TI TMS320C80 tic80-*-*
7013 * OBSOLETE configurations
7015 Altos 3068 m68*-altos-*
7016 Convex c1-*-*, c2-*-*
7018 ARM RISCix arm-*-* (as host)
7021 Configurations that have been declared obsolete will be commented out,
7022 but the code will be left in place. If there is no activity to revive
7023 these configurations before the next release of GDB, the sources will
7024 be permanently REMOVED.
7026 * Gould support removed
7028 Support for the Gould PowerNode and NP1 has been removed.
7030 * New features for SVR4
7032 On SVR4 native platforms (such as Solaris), if you attach to a process
7033 without first loading a symbol file, GDB will now attempt to locate and
7034 load symbols from the running process's executable file.
7036 * Many C++ enhancements
7038 C++ support has been greatly improved. Overload resolution now works properly
7039 in almost all cases. RTTI support is on the way.
7041 * Remote targets can connect to a sub-program
7043 A popen(3) style serial-device has been added. This device starts a
7044 sub-process (such as a stand-alone simulator) and then communicates
7045 with that. The sub-program to run is specified using the syntax
7046 ``|<program> <args>'' vis:
7048 (gdb) set remotedebug 1
7049 (gdb) target extended-remote |mn10300-elf-sim program-args
7051 * MIPS 64 remote protocol
7053 A long standing bug in the mips64 remote protocol where by GDB
7054 expected certain 32 bit registers (ex SR) to be transfered as 32
7055 instead of 64 bits has been fixed.
7057 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7058 added to provide backward compatibility with older versions of GDB.
7060 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7062 The command ``set remotebinarydownload'' command has been replaced by
7063 ``set remote X-packet''. Other commands in ``set remote'' family
7064 include ``set remote P-packet''.
7066 * Breakpoint commands accept ranges.
7068 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7069 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7070 ``tracepoint passcount'' also accepts a range of tracepoints.
7072 * ``apropos'' command added.
7074 The ``apropos'' command searches through command names and
7075 documentation strings, printing out matches, making it much easier to
7076 try to find a command that does what you are looking for.
7080 A new machine oriented interface (MI) has been added to GDB. This
7081 interface is designed for debug environments running GDB as a separate
7082 process. This is part of the long term libGDB project. See the
7083 "GDB/MI" chapter of the GDB manual for further information. It can be
7084 enabled by configuring with:
7086 .../configure --enable-gdbmi
7088 *** Changes in GDB-4.18:
7090 * New native configurations
7092 HP-UX 10.20 hppa*-*-hpux10.20
7093 HP-UX 11.x hppa*-*-hpux11.0*
7094 M68K GNU/Linux m68*-*-linux*
7098 Fujitsu FR30 fr30-*-elf*
7099 Intel StrongARM strongarm-*-*
7100 Mitsubishi D30V d30v-*-*
7102 * OBSOLETE configurations
7104 Gould PowerNode, NP1 np1-*-*, pn-*-*
7106 Configurations that have been declared obsolete will be commented out,
7107 but the code will be left in place. If there is no activity to revive
7108 these configurations before the next release of GDB, the sources will
7109 be permanently REMOVED.
7113 As a compatibility experiment, GDB's source files buildsym.h and
7114 buildsym.c have been converted to pure standard C, no longer
7115 containing any K&R compatibility code. We believe that all systems in
7116 use today either come with a standard C compiler, or have a GCC port
7117 available. If this is not true, please report the affected
7118 configuration to bug-gdb@gnu.org immediately. See the README file for
7119 information about getting a standard C compiler if you don't have one
7124 GDB now uses readline 2.2.
7126 * set extension-language
7128 You can now control the mapping between filename extensions and source
7129 languages by using the `set extension-language' command. For instance,
7130 you can ask GDB to treat .c files as C++ by saying
7131 set extension-language .c c++
7132 The command `info extensions' lists all of the recognized extensions
7133 and their associated languages.
7135 * Setting processor type for PowerPC and RS/6000
7137 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7138 you can use the `set processor' command to specify what variant of the
7139 PowerPC family you are debugging. The command
7143 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7144 following PowerPC and RS6000 variants:
7146 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7147 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7149 403GC IBM PowerPC 403GC
7150 505 Motorola PowerPC 505
7151 860 Motorola PowerPC 860 or 850
7152 601 Motorola PowerPC 601
7153 602 Motorola PowerPC 602
7154 603 Motorola/IBM PowerPC 603 or 603e
7155 604 Motorola PowerPC 604 or 604e
7156 750 Motorola/IBM PowerPC 750 or 750
7158 At the moment, this command just tells GDB what to name the
7159 special-purpose processor registers. Since almost all the affected
7160 registers are inaccessible to user-level programs, this command is
7161 only useful for remote debugging in its present form.
7165 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7166 more extensive support for HP-UX. Added features include shared
7167 library support, kernel threads and hardware watchpoints for 11.00,
7168 support for HP's ANSI C and C++ compilers, and a compatibility mode
7169 for xdb and dbx commands.
7173 HP's donation includes the new concept of catchpoints, which is a
7174 generalization of the old catch command. On HP-UX, it is now possible
7175 to catch exec, fork, and vfork, as well as library loading.
7177 This means that the existing catch command has changed; its first
7178 argument now specifies the type of catch to be set up. See the
7179 output of "help catch" for a list of catchpoint types.
7181 * Debugging across forks
7183 On HP-UX, you can choose which process to debug when a fork() happens
7188 HP has donated a curses-based terminal user interface (TUI). To get
7189 it, build with --enable-tui. Although this can be enabled for any
7190 configuration, at present it only works for native HP debugging.
7192 * GDB remote protocol additions
7194 A new protocol packet 'X' that writes binary data is now available.
7195 Default behavior is to try 'X', then drop back to 'M' if the stub
7196 fails to respond. The settable variable `remotebinarydownload'
7197 allows explicit control over the use of 'X'.
7199 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7200 full 64-bit address. The command
7202 set remoteaddresssize 32
7204 can be used to revert to the old behaviour. For existing remote stubs
7205 the change should not be noticed, as the additional address information
7208 In order to assist in debugging stubs, you may use the maintenance
7209 command `packet' to send any text string to the stub. For instance,
7211 maint packet heythere
7213 sends the packet "$heythere#<checksum>". Note that it is very easy to
7214 disrupt a debugging session by sending the wrong packet at the wrong
7217 The compare-sections command allows you to compare section data on the
7218 target to what is in the executable file without uploading or
7219 downloading, by comparing CRC checksums.
7221 * Tracing can collect general expressions
7223 You may now collect general expressions at tracepoints. This requires
7224 further additions to the target-side stub; see tracepoint.c and
7225 doc/agentexpr.texi for further details.
7227 * mask-address variable for Mips
7229 For Mips targets, you may control the zeroing of the upper 32 bits of
7230 a 64-bit address by entering `set mask-address on'. This is mainly
7231 of interest to users of embedded R4xxx and R5xxx processors.
7233 * Higher serial baud rates
7235 GDB's serial code now allows you to specify baud rates 57600, 115200,
7236 230400, and 460800 baud. (Note that your host system may not be able
7237 to achieve all of these rates.)
7241 The i960 configuration now includes an initial implementation of a
7242 builtin simulator, contributed by Jim Wilson.
7245 *** Changes in GDB-4.17:
7247 * New native configurations
7249 Alpha GNU/Linux alpha*-*-linux*
7250 Unixware 2.x i[3456]86-unixware2*
7251 Irix 6.x mips*-sgi-irix6*
7252 PowerPC GNU/Linux powerpc-*-linux*
7253 PowerPC Solaris powerpcle-*-solaris*
7254 Sparc GNU/Linux sparc-*-linux*
7255 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7259 Argonaut Risc Chip (ARC) arc-*-*
7260 Hitachi H8/300S h8300*-*-*
7261 Matsushita MN10200 w/simulator mn10200-*-*
7262 Matsushita MN10300 w/simulator mn10300-*-*
7263 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7264 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7265 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7266 Mitsubishi D10V w/simulator d10v-*-*
7267 Mitsubishi M32R/D w/simulator m32r-*-elf*
7268 Tsqware Sparclet sparclet-*-*
7269 NEC V850 w/simulator v850-*-*
7271 * New debugging protocols
7273 ARM with RDI protocol arm*-*-*
7274 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7275 DDB and LSI variants of PMON protocol mips*-*-*
7276 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7277 PowerPC with SDS protocol powerpc{,le}-*-eabi
7278 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7282 All configurations can now understand and use the DWARF 2 debugging
7283 format. The choice is automatic, if the symbol file contains DWARF 2
7288 GDB now includes basic Java language support. This support is
7289 only useful with Java compilers that produce native machine code.
7291 * solib-absolute-prefix and solib-search-path
7293 For SunOS and SVR4 shared libraries, you may now set the prefix for
7294 loading absolute shared library symbol files, and the search path for
7295 locating non-absolute shared library symbol files.
7297 * Live range splitting
7299 GDB can now effectively debug code for which GCC has performed live
7300 range splitting as part of its optimization. See gdb/doc/LRS for
7301 more details on the expected format of the stabs information.
7305 GDB's support for the GNU Hurd, including thread debugging, has been
7306 updated to work with current versions of the Hurd.
7310 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7311 instruction set. ARM GDB automatically detects when Thumb
7312 instructions are in use, and adjusts disassembly and backtracing
7317 GDB's MIPS target configurations now handle the MIP16 16-bit
7322 GDB now includes support for overlays; if an executable has been
7323 linked such that multiple sections are based at the same address, GDB
7324 will decide which section to use for symbolic info. You can choose to
7325 control the decision manually, using overlay commands, or implement
7326 additional target-side support and use "overlay load-target" to bring
7327 in the overlay mapping. Do "help overlay" for more detail.
7331 The command "info symbol <address>" displays information about
7332 the symbol at the specified address.
7336 The standard remote protocol now includes an extension that allows
7337 asynchronous collection and display of trace data. This requires
7338 extensive support in the target-side debugging stub. Tracing mode
7339 includes a new interaction mode in GDB and new commands: see the
7340 file tracepoint.c for more details.
7344 Configurations for embedded MIPS now include a simulator contributed
7345 by Cygnus Solutions. The simulator supports the instruction sets
7346 of most MIPS variants.
7350 Sparc configurations may now include the ERC32 simulator contributed
7351 by the European Space Agency. The simulator is not built into
7352 Sparc targets by default; configure with --enable-sim to include it.
7356 For target configurations that may include multiple variants of a
7357 basic architecture (such as MIPS and SH), you may now set the
7358 architecture explicitly. "set arch" sets, "info arch" lists
7359 the possible architectures.
7361 *** Changes in GDB-4.16:
7363 * New native configurations
7365 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7366 M68K NetBSD m68k-*-netbsd*
7367 PowerPC AIX 4.x powerpc-*-aix*
7368 PowerPC MacOS powerpc-*-macos*
7369 PowerPC Windows NT powerpcle-*-cygwin32
7370 RS/6000 AIX 4.x rs6000-*-aix4*
7374 ARM with RDP protocol arm-*-*
7375 I960 with MON960 i960-*-coff
7376 MIPS VxWorks mips*-*-vxworks*
7377 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7378 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7380 Matra Sparclet sparclet-*-*
7384 The powerpc-eabi configuration now includes the PSIM simulator,
7385 contributed by Andrew Cagney, with assistance from Mike Meissner.
7386 PSIM is a very elaborate model of the PowerPC, including not only
7387 basic instruction set execution, but also details of execution unit
7388 performance and I/O hardware. See sim/ppc/README for more details.
7392 GDB now works with Solaris 2.5.
7394 * Windows 95/NT native
7396 GDB will now work as a native debugger on Windows 95 and Windows NT.
7397 To build it from source, you must use the "gnu-win32" environment,
7398 which uses a DLL to emulate enough of Unix to run the GNU tools.
7399 Further information, binaries, and sources are available at
7400 ftp.cygnus.com, under pub/gnu-win32.
7402 * dont-repeat command
7404 If a user-defined command includes the command `dont-repeat', then the
7405 command will not be repeated if the user just types return. This is
7406 useful if the command is time-consuming to run, so that accidental
7407 extra keystrokes don't run the same command many times.
7409 * Send break instead of ^C
7411 The standard remote protocol now includes an option to send a break
7412 rather than a ^C to the target in order to interrupt it. By default,
7413 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7415 * Remote protocol timeout
7417 The standard remote protocol includes a new variable `remotetimeout'
7418 that allows you to set the number of seconds before GDB gives up trying
7419 to read from the target. The default value is 2.
7421 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7423 By default GDB will automatically keep track of objects as they are
7424 loaded and unloaded by the dynamic linker. By using the command `set
7425 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7426 when shared library events occur, thus allowing you to set breakpoints
7427 in shared libraries which are explicitly loaded by the inferior.
7429 Note this feature does not work on hpux8. On hpux9 you must link
7430 /usr/lib/end.o into your program. This feature should work
7431 automatically on hpux10.
7433 * Irix 5.x hardware watchpoint support
7435 Irix 5 configurations now support the use of hardware watchpoints.
7437 * Mips protocol "SYN garbage limit"
7439 When debugging a Mips target using the `target mips' protocol, you
7440 may set the number of characters that GDB will ignore by setting
7441 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7442 every character. The default value is 1050.
7444 * Recording and replaying remote debug sessions
7446 If you set `remotelogfile' to the name of a file, gdb will write to it
7447 a recording of a remote debug session. This recording may then be
7448 replayed back to gdb using "gdbreplay". See gdbserver/README for
7449 details. This is useful when you have a problem with GDB while doing
7450 remote debugging; you can make a recording of the session and send it
7451 to someone else, who can then recreate the problem.
7453 * Speedups for remote debugging
7455 GDB includes speedups for downloading and stepping MIPS systems using
7456 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7457 and more efficient S-record downloading.
7459 * Memory use reductions and statistics collection
7461 GDB now uses less memory and reports statistics about memory usage.
7462 Try the `maint print statistics' command, for example.
7464 *** Changes in GDB-4.15:
7466 * Psymtabs for XCOFF
7468 The symbol reader for AIX GDB now uses partial symbol tables. This
7469 can greatly improve startup time, especially for large executables.
7471 * Remote targets use caching
7473 Remote targets now use a data cache to speed up communication with the
7474 remote side. The data cache could lead to incorrect results because
7475 it doesn't know about volatile variables, thus making it impossible to
7476 debug targets which use memory mapped I/O devices. `set remotecache
7477 off' turns the data cache off.
7479 * Remote targets may have threads
7481 The standard remote protocol now includes support for multiple threads
7482 in the target system, using new protocol commands 'H' and 'T'. See
7483 gdb/remote.c for details.
7487 If GDB is configured with `--enable-netrom', then it will include
7488 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7489 acts as though it is a bank of ROM on the target board, but you can
7490 write into it over the network. GDB's support consists only of
7491 support for fast loading into the emulated ROM; to debug, you must use
7492 another protocol, such as standard remote protocol. The usual
7493 sequence is something like
7495 target nrom <netrom-hostname>
7497 target remote <netrom-hostname>:1235
7501 GDB now includes support for the Apple Macintosh, as a host only. It
7502 may be run as either an MPW tool or as a standalone application, and
7503 it can debug through the serial port. All the usual GDB commands are
7504 available, but to the target command, you must supply "serial" as the
7505 device type instead of "/dev/ttyXX". See mpw-README in the main
7506 directory for more information on how to build. The MPW configuration
7507 scripts */mpw-config.in support only a few targets, and only the
7508 mips-idt-ecoff target has been tested.
7512 GDB configuration now uses autoconf. This is not user-visible,
7513 but does simplify configuration and building.
7517 GDB now supports hpux10.
7519 *** Changes in GDB-4.14:
7521 * New native configurations
7523 x86 FreeBSD i[345]86-*-freebsd
7524 x86 NetBSD i[345]86-*-netbsd
7525 NS32k NetBSD ns32k-*-netbsd
7526 Sparc NetBSD sparc-*-netbsd
7530 A29K VxWorks a29k-*-vxworks
7531 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7532 CPU32 EST-300 emulator m68*-*-est*
7533 PowerPC ELF powerpc-*-elf
7536 * Alpha OSF/1 support for procfs
7538 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7539 possible to attach to running processes. As the mounting of the /proc
7540 filesystem is optional on the Alpha, GDB automatically determines
7541 the availability of /proc during startup. This can lead to problems
7542 if /proc is unmounted after GDB has been started.
7544 * Arguments to user-defined commands
7546 User commands may accept up to 10 arguments separated by whitespace.
7547 Arguments are accessed within the user command via $arg0..$arg9. A
7550 print $arg0 + $arg1 + $arg2
7552 To execute the command use:
7555 Defines the command "adder" which prints the sum of its three arguments.
7556 Note the arguments are text substitutions, so they may reference variables,
7557 use complex expressions, or even perform inferior function calls.
7559 * New `if' and `while' commands
7561 This makes it possible to write more sophisticated user-defined
7562 commands. Both commands take a single argument, which is the
7563 expression to evaluate, and must be followed by the commands to
7564 execute, one per line, if the expression is nonzero, the list being
7565 terminated by the word `end'. The `if' command list may include an
7566 `else' word, which causes the following commands to be executed only
7567 if the expression is zero.
7569 * Fortran source language mode
7571 GDB now includes partial support for Fortran 77. It will recognize
7572 Fortran programs and can evaluate a subset of Fortran expressions, but
7573 variables and functions may not be handled correctly. GDB will work
7574 with G77, but does not yet know much about symbols emitted by other
7577 * Better HPUX support
7579 Most debugging facilities now work on dynamic executables for HPPAs
7580 running hpux9 or later. You can attach to running dynamically linked
7581 processes, but by default the dynamic libraries will be read-only, so
7582 for instance you won't be able to put breakpoints in them. To change
7583 that behavior do the following before running the program:
7589 This will cause the libraries to be mapped private and read-write.
7590 To revert to the normal behavior, do this:
7596 You cannot set breakpoints or examine data in the library until after
7597 the library is loaded if the function/data symbols do not have
7600 GDB can now also read debug symbols produced by the HP C compiler on
7601 HPPAs (sorry, no C++, Fortran or 68k support).
7603 * Target byte order now dynamically selectable
7605 You can choose which byte order to use with a target system, via the
7606 commands "set endian big" and "set endian little", and you can see the
7607 current setting by using "show endian". You can also give the command
7608 "set endian auto", in which case GDB will use the byte order
7609 associated with the executable. Currently, only embedded MIPS
7610 configurations support dynamic selection of target byte order.
7612 * New DOS host serial code
7614 This version uses DPMI interrupts to handle buffered I/O, so you
7615 no longer need to run asynctsr when debugging boards connected to
7618 *** Changes in GDB-4.13:
7620 * New "complete" command
7622 This lists all the possible completions for the rest of the line, if it
7623 were to be given as a command itself. This is intended for use by emacs.
7625 * Trailing space optional in prompt
7627 "set prompt" no longer adds a space for you after the prompt you set. This
7628 allows you to set a prompt which ends in a space or one that does not.
7630 * Breakpoint hit counts
7632 "info break" now displays a count of the number of times the breakpoint
7633 has been hit. This is especially useful in conjunction with "ignore"; you
7634 can ignore a large number of breakpoint hits, look at the breakpoint info
7635 to see how many times the breakpoint was hit, then run again, ignoring one
7636 less than that number, and this will get you quickly to the last hit of
7639 * Ability to stop printing at NULL character
7641 "set print null-stop" will cause GDB to stop printing the characters of
7642 an array when the first NULL is encountered. This is useful when large
7643 arrays actually contain only short strings.
7645 * Shared library breakpoints
7647 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7648 breakpoints in shared libraries before the executable is run.
7650 * Hardware watchpoints
7652 There is a new hardware breakpoint for the watch command for sparclite
7653 targets. See gdb/sparclite/hw_breakpoint.note.
7655 Hardware watchpoints are also now supported under GNU/Linux.
7659 Annotations have been added. These are for use with graphical interfaces,
7660 and are still experimental. Currently only gdba.el uses these.
7662 * Improved Irix 5 support
7664 GDB now works properly with Irix 5.2.
7666 * Improved HPPA support
7668 GDB now works properly with the latest GCC and GAS.
7670 * New native configurations
7672 Sequent PTX4 i[34]86-sequent-ptx4
7673 HPPA running OSF/1 hppa*-*-osf*
7674 Atari TT running SVR4 m68*-*-sysv4*
7675 RS/6000 LynxOS rs6000-*-lynxos*
7679 OS/9000 i[34]86-*-os9k
7680 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7683 * Hitachi SH7000 and E7000-PC ICE support
7685 There is now support for communicating with the Hitachi E7000-PC ICE.
7686 This is available automatically when GDB is configured for the SH.
7690 As usual, a variety of small fixes and improvements, both generic
7691 and configuration-specific. See the ChangeLog for more detail.
7693 *** Changes in GDB-4.12:
7695 * Irix 5 is now supported
7699 GDB-4.12 on the HPPA has a number of changes which make it unable
7700 to debug the output from the currently released versions of GCC and
7701 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7702 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7703 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7706 *** Changes in GDB-4.11:
7708 * User visible changes:
7712 The "set remotedebug" option is now consistent between the mips remote
7713 target, remote targets using the gdb-specific protocol, UDI (AMD's
7714 debug protocol for the 29k) and the 88k bug monitor. It is now an
7715 integer specifying a debug level (normally 0 or 1, but 2 means more
7716 debugging info for the mips target).
7718 * DEC Alpha native support
7720 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7721 debug info, but GDB works fairly well with the DEC compiler and should
7722 work with a future GCC release. See the README file for a few
7723 Alpha-specific notes.
7725 * Preliminary thread implementation
7727 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7729 * LynxOS native and target support for 386
7731 This release has been hosted on LynxOS 2.2, and also can be configured
7732 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7735 * Improvements in C++ mangling/demangling.
7737 This release has much better g++ debugging, specifically in name
7738 mangling/demangling, virtual function calls, print virtual table,
7739 call methods, ...etc.
7741 *** Changes in GDB-4.10:
7743 * User visible changes:
7745 Remote debugging using the GDB-specific (`target remote') protocol now
7746 supports the `load' command. This is only useful if you have some
7747 other way of getting the stub to the target system, and you can put it
7748 somewhere in memory where it won't get clobbered by the download.
7750 Filename completion now works.
7752 When run under emacs mode, the "info line" command now causes the
7753 arrow to point to the line specified. Also, "info line" prints
7754 addresses in symbolic form (as well as hex).
7756 All vxworks based targets now support a user settable option, called
7757 vxworks-timeout. This option represents the number of seconds gdb
7758 should wait for responses to rpc's. You might want to use this if
7759 your vxworks target is, perhaps, a slow software simulator or happens
7760 to be on the far side of a thin network line.
7764 This release contains support for using a DEC alpha as a GDB host for
7765 cross debugging. Native alpha debugging is not supported yet.
7768 *** Changes in GDB-4.9:
7772 This is the first GDB release which is accompanied by a matching testsuite.
7773 The testsuite requires installation of dejagnu, which should be available
7774 via ftp from most sites that carry GNU software.
7778 'Cfront' style demangling has had its name changed to 'ARM' style, to
7779 emphasize that it was written from the specifications in the C++ Annotated
7780 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7781 disclaimers, it still generated too much confusion with users attempting to
7782 use gdb with AT&T cfront.
7786 GDB now uses a standard remote interface to a simulator library.
7787 So far, the library contains simulators for the Zilog Z8001/2, the
7788 Hitachi H8/300, H8/500 and Super-H.
7790 * New targets supported
7792 H8/300 simulator h8300-hitachi-hms or h8300hms
7793 H8/500 simulator h8500-hitachi-hms or h8500hms
7794 SH simulator sh-hitachi-hms or sh
7795 Z8000 simulator z8k-zilog-none or z8ksim
7796 IDT MIPS board over serial line mips-idt-ecoff
7798 Cross-debugging to GO32 targets is supported. It requires a custom
7799 version of the i386-stub.c module which is integrated with the
7800 GO32 memory extender.
7802 * New remote protocols
7804 MIPS remote debugging protocol.
7806 * New source languages supported
7808 This version includes preliminary support for Chill, a Pascal like language
7809 used by telecommunications companies. Chill support is also being integrated
7810 into the GNU compiler, but we don't know when it will be publically available.
7813 *** Changes in GDB-4.8:
7815 * HP Precision Architecture supported
7817 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7818 version of this support was available as a set of patches from the
7819 University of Utah. GDB does not support debugging of programs
7820 compiled with the HP compiler, because HP will not document their file
7821 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7822 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7824 Many problems in the preliminary version have been fixed.
7826 * Faster and better demangling
7828 We have improved template demangling and fixed numerous bugs in the GNU style
7829 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7830 character types (wchar_t) are now supported. Demangling of each symbol is now
7831 only done once, and is cached when the symbol table for a file is read in.
7832 This results in a small increase in memory usage for C programs, a moderate
7833 increase in memory usage for C++ programs, and a fantastic speedup in
7836 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7837 from the specifications in the Annotated Reference Manual, which AT&T's
7838 compiler does not actually implement.
7840 * G++ multiple inheritance compiler problem
7842 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7843 inheritance lattices was reworked to properly discover ambiguities. We
7844 recently found an example which causes this new algorithm to fail in a
7845 very subtle way, producing bad debug information for those classes.
7846 The file 'gcc.patch' (in this directory) can be applied to gcc to
7847 circumvent the problem. A future GCC release will contain a complete
7850 The previous G++ debug info problem (mentioned below for the gdb-4.7
7851 release) is fixed in gcc version 2.3.2.
7853 * Improved configure script
7855 The `configure' script will now attempt to guess your system type if
7856 you don't supply a host system type. The old scheme of supplying a
7857 host system triplet is preferable over using this. All the magic is
7858 done in the new `config.guess' script. Examine it for details.
7860 We have also brought our configure script much more in line with the FSF's
7861 version. It now supports the --with-xxx options. In particular,
7862 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7863 The resulting GDB will not be able to read arbitrary object file formats --
7864 only the format ``expected'' to be used on the configured target system.
7865 We hope to make this the default in a future release.
7867 * Documentation improvements
7869 There's new internal documentation on how to modify GDB, and how to
7870 produce clean changes to the code. We implore people to read it
7871 before submitting changes.
7873 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7874 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7875 `info' files are also provided. To build `info' files from scratch,
7876 you will need the latest `makeinfo' release, which will be available in
7877 a future texinfo-X.Y release.
7879 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7880 We're not sure exactly which versions have this problem, but it has
7881 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7882 or better. If that isn't possible, there is a patch in
7883 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7884 around this problem.
7888 GDB now supports array constants that can be used in expressions typed in by
7889 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7890 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7893 The new directory `gdb/sparclite' contains a program that demonstrates
7894 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7896 * New native hosts supported
7898 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7899 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7901 * New targets supported
7903 AMD 29k family via UDI a29k-amd-udi or udi29k
7905 * New file formats supported
7907 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7908 HPUX core files, and SCO 3.2v2 core files.
7912 Attaching to processes now works again; thanks for the many bug reports.
7914 We have also stomped on a bunch of core dumps caused by
7915 printf_filtered("%s") problems.
7917 We eliminated a copyright problem on the rpc and ptrace header files
7918 for VxWorks, which was discovered at the last minute during the 4.7
7919 release. You should now be able to build a VxWorks GDB.
7921 You can now interrupt gdb while an attached process is running. This
7922 will cause the attached process to stop, and give control back to GDB.
7924 We fixed problems caused by using too many file descriptors
7925 for reading symbols from object files and libraries. This was
7926 especially a problem for programs that used many (~100) shared
7929 The `step' command now only enters a subroutine if there is line number
7930 information for the subroutine. Otherwise it acts like the `next'
7931 command. Previously, `step' would enter subroutines if there was
7932 any debugging information about the routine. This avoids problems
7933 when using `cc -g1' on MIPS machines.
7935 * Internal improvements
7937 GDB's internal interfaces have been improved to make it easier to support
7938 debugging of multiple languages in the future.
7940 GDB now uses a common structure for symbol information internally.
7941 Minimal symbols (derived from linkage symbols in object files), partial
7942 symbols (from a quick scan of debug information), and full symbols
7943 contain a common subset of information, making it easier to write
7944 shared code that handles any of them.
7946 * New command line options
7948 We now accept --silent as an alias for --quiet.
7952 The memory-mapped-malloc library is now licensed under the GNU Library
7953 General Public License.
7955 *** Changes in GDB-4.7:
7957 * Host/native/target split
7959 GDB has had some major internal surgery to untangle the support for
7960 hosts and remote targets. Now, when you configure GDB for a remote
7961 target, it will no longer load in all of the support for debugging
7962 local programs on the host. When fully completed and tested, this will
7963 ensure that arbitrary host/target combinations are possible.
7965 The primary conceptual shift is to separate the non-portable code in
7966 GDB into three categories. Host specific code is required any time GDB
7967 is compiled on that host, regardless of the target. Target specific
7968 code relates to the peculiarities of the target, but can be compiled on
7969 any host. Native specific code is everything else: it can only be
7970 built when the host and target are the same system. Child process
7971 handling and core file support are two common `native' examples.
7973 GDB's use of /proc for controlling Unix child processes is now cleaner.
7974 It has been split out into a single module under the `target_ops' vector,
7975 plus two native-dependent functions for each system that uses /proc.
7977 * New hosts supported
7979 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7980 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7981 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7983 * New targets supported
7985 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7986 68030 and CPU32 m68030-*-*, m68332-*-*
7988 * New native hosts supported
7990 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7991 (386bsd is not well tested yet)
7992 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7994 * New file formats supported
7996 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7997 supports reading of `a.out.adobe' object files, which are an a.out
7998 format extended with minimal information about multiple sections.
8002 `show copying' is the same as the old `info copying'.
8003 `show warranty' is the same as `info warrantee'.
8004 These were renamed for consistency. The old commands continue to work.
8006 `info handle' is a new alias for `info signals'.
8008 You can now define pre-command hooks, which attach arbitrary command
8009 scripts to any command. The commands in the hook will be executed
8010 prior to the user's command. You can also create a hook which will be
8011 executed whenever the program stops. See gdb.texinfo.
8015 We now deal with Cfront style name mangling, and can even extract type
8016 info from mangled symbols. GDB can automatically figure out which
8017 symbol mangling style your C++ compiler uses.
8019 Calling of methods and virtual functions has been improved as well.
8023 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8024 fixed. This was due to mishandling of the extra N_SO stabs output
8027 We also finally got Ultrix 4.2 running in house, and fixed core file
8028 support, with help from a dozen people on the net.
8030 John M. Farrell discovered that the reason that single-stepping was so
8031 slow on all of the Mips based platforms (primarily SGI and DEC) was
8032 that we were trying to demangle and lookup a symbol used for internal
8033 purposes on every instruction that was being stepped through. Changing
8034 the name of that symbol so that it couldn't be mistaken for a C++
8035 mangled symbol sped things up a great deal.
8037 Rich Pixley sped up symbol lookups in general by getting much smarter
8038 about when C++ symbol mangling is necessary. This should make symbol
8039 completion (TAB on the command line) much faster. It's not as fast as
8040 we'd like, but it's significantly faster than gdb-4.6.
8044 A new user controllable variable 'call_scratch_address' can
8045 specify the location of a scratch area to be used when GDB
8046 calls a function in the target. This is necessary because the
8047 usual method of putting the scratch area on the stack does not work
8048 in systems that have separate instruction and data spaces.
8050 We integrated changes to support the 29k UDI (Universal Debugger
8051 Interface), but discovered at the last minute that we didn't have all
8052 of the appropriate copyright paperwork. We are working with AMD to
8053 resolve this, and hope to have it available soon.
8057 We have sped up the remote serial line protocol, especially for targets
8058 with lots of registers. It now supports a new `expedited status' ('T')
8059 message which can be used in place of the existing 'S' status message.
8060 This allows the remote stub to send only the registers that GDB
8061 needs to make a quick decision about single-stepping or conditional
8062 breakpoints, eliminating the need to fetch the entire register set for
8063 each instruction being stepped through.
8065 The GDB remote serial protocol now implements a write-through cache for
8066 registers, only re-reading the registers if the target has run.
8068 There is also a new remote serial stub for SPARC processors. You can
8069 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8070 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8071 processor with a serial port.
8075 Configure.in files have become much easier to read and modify. A new
8076 `table driven' format makes it more obvious what configurations are
8077 supported, and what files each one uses.
8081 There is a new opcodes library which will eventually contain all of the
8082 disassembly routines and opcode tables. At present, it only contains
8083 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8084 disassembler (binutils/objdump) to share these routines.
8086 The libiberty library is now copylefted under the GNU Library General
8087 Public License. This allows more liberal use, and was done so libg++
8088 can use it. This makes no difference to GDB, since the Library License
8089 grants all the rights from the General Public License.
8093 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8094 reference to the stabs symbol info used by the debugger. It is (as far
8095 as we know) the only published document on this fascinating topic. We
8096 encourage you to read it, compare it to the stabs information on your
8097 system, and send improvements on the document in general (to
8098 bug-gdb@prep.ai.mit.edu).
8100 And, of course, many bugs have been fixed.
8103 *** Changes in GDB-4.6:
8105 * Better support for C++ function names
8107 GDB now accepts as input the "demangled form" of C++ overloaded function
8108 names and member function names, and can do command completion on such names
8109 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8110 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8111 Make use of command completion, it is your friend.
8113 GDB also now accepts a variety of C++ mangled symbol formats. They are
8114 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8115 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8116 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8117 for the list of formats.
8119 * G++ symbol mangling problem
8121 Recent versions of gcc have a bug in how they emit debugging information for
8122 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8123 directory) can be applied to gcc to fix the problem. Alternatively, if you
8124 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8125 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8126 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8129 * New 'maintenance' command
8131 All of the commands related to hacking GDB internals have been moved out of
8132 the main command set, and now live behind the 'maintenance' command. This
8133 can also be abbreviated as 'mt'. The following changes were made:
8135 dump-me -> maintenance dump-me
8136 info all-breakpoints -> maintenance info breakpoints
8137 printmsyms -> maintenance print msyms
8138 printobjfiles -> maintenance print objfiles
8139 printpsyms -> maintenance print psymbols
8140 printsyms -> maintenance print symbols
8142 The following commands are new:
8144 maintenance demangle Call internal GDB demangler routine to
8145 demangle a C++ link name and prints the result.
8146 maintenance print type Print a type chain for a given symbol
8148 * Change to .gdbinit file processing
8150 We now read the $HOME/.gdbinit file before processing the argv arguments
8151 (e.g. reading symbol files or core files). This allows global parameters to
8152 be set, which will apply during the symbol reading. The ./.gdbinit is still
8153 read after argv processing.
8155 * New hosts supported
8157 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8159 GNU/Linux support i386-unknown-linux or linux
8161 We are also including code to support the HP/PA running BSD and HPUX. This
8162 is almost guaranteed not to work, as we didn't have time to test or build it
8163 for this release. We are including it so that the more adventurous (or
8164 masochistic) of you can play with it. We also had major problems with the
8165 fact that the compiler that we got from HP doesn't support the -g option.
8168 * New targets supported
8170 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8172 * More smarts about finding #include files
8174 GDB now remembers the compilation directory for all include files, and for
8175 all files from which C is generated (like yacc and lex sources). This
8176 greatly improves GDB's ability to find yacc/lex sources, and include files,
8177 especially if you are debugging your program from a directory different from
8178 the one that contains your sources.
8180 We also fixed a bug which caused difficulty with listing and setting
8181 breakpoints in include files which contain C code. (In the past, you had to
8182 try twice in order to list an include file that you hadn't looked at before.)
8184 * Interesting infernals change
8186 GDB now deals with arbitrary numbers of sections, where the symbols for each
8187 section must be relocated relative to that section's landing place in the
8188 target's address space. This work was needed to support ELF with embedded
8189 stabs used by Solaris-2.0.
8191 * Bug fixes (of course!)
8193 There have been loads of fixes for the following things:
8194 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8195 i960, stabs, DOS(GO32), procfs, etc...
8197 See the ChangeLog for details.
8199 *** Changes in GDB-4.5:
8201 * New machines supported (host and target)
8203 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8205 SGI Irix-4.x mips-sgi-irix4 or iris4
8207 * New malloc package
8209 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8210 Mmalloc is capable of handling multiple heaps of memory. It is also
8211 capable of saving a heap to a file, and then mapping it back in later.
8212 This can be used to greatly speedup the startup of GDB by using a
8213 pre-parsed symbol table which lives in a mmalloc managed heap. For
8214 more details, please read mmalloc/mmalloc.texi.
8218 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8219 'help info proc' for details.
8221 * MIPS ecoff symbol table format
8223 The code that reads MIPS symbol table format is now supported on all hosts.
8224 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8227 * File name changes for MS-DOS
8229 Many files in the config directories have been renamed to make it easier to
8230 support GDB on MS-DOSe systems (which have very restrictive file name
8231 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8232 environment) is close to working but has some remaining problems. Note
8233 that debugging of DOS programs is not supported, due to limitations
8234 in the ``operating system'', but it can be used to host cross-debugging.
8236 * Cross byte order fixes
8238 Many fixes have been made to support cross debugging of Sparc and MIPS
8239 targets from hosts whose byte order differs.
8241 * New -mapped and -readnow options
8243 If memory-mapped files are available on your system through the 'mmap'
8244 system call, you can use the -mapped option on the `file' or
8245 `symbol-file' commands to cause GDB to write the symbols from your
8246 program into a reusable file. If the program you are debugging is
8247 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8248 Future GDB debugging sessions will notice the presence of this file,
8249 and will quickly map in symbol information from it, rather than reading
8250 the symbol table from the executable program. Using the '-mapped'
8251 option in a GDB `file' or `symbol-file' command has the same effect as
8252 starting GDB with the '-mapped' command-line option.
8254 You can cause GDB to read the entire symbol table immediately by using
8255 the '-readnow' option with any of the commands that load symbol table
8256 information (or on the GDB command line). This makes the command
8257 slower, but makes future operations faster.
8259 The -mapped and -readnow options are typically combined in order to
8260 build a `fred.syms' file that contains complete symbol information.
8261 A simple GDB invocation to do nothing but build a `.syms' file for future
8264 gdb -batch -nx -mapped -readnow programname
8266 The `.syms' file is specific to the host machine on which GDB is run.
8267 It holds an exact image of GDB's internal symbol table. It cannot be
8268 shared across multiple host platforms.
8270 * longjmp() handling
8272 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8273 siglongjmp() without losing control. This feature has not yet been ported to
8274 all systems. It currently works on many 386 platforms, all MIPS-based
8275 platforms (SGI, DECstation, etc), and Sun3/4.
8279 Preliminary work has been put in to support the new Solaris OS from Sun. At
8280 this time, it can control and debug processes, but it is not capable of
8285 As always, many many bug fixes. The major areas were with g++, and mipsread.
8286 People using the MIPS-based platforms should experience fewer mysterious
8287 crashes and trashed symbol tables.
8289 *** Changes in GDB-4.4:
8291 * New machines supported (host and target)
8293 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8295 BSD Reno on Vax vax-dec-bsd
8296 Ultrix on Vax vax-dec-ultrix
8298 * New machines supported (target)
8300 AMD 29000 embedded, using EBMON a29k-none-none
8304 GDB continues to improve its handling of C++. `References' work better.
8305 The demangler has also been improved, and now deals with symbols mangled as
8306 per the Annotated C++ Reference Guide.
8308 GDB also now handles `stabs' symbol information embedded in MIPS
8309 `ecoff' symbol tables. Since the ecoff format was not easily
8310 extensible to handle new languages such as C++, this appeared to be a
8311 good way to put C++ debugging info into MIPS binaries. This option
8312 will be supported in the GNU C compiler, version 2, when it is
8315 * New features for SVR4
8317 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8318 shared libraries. Debugging dynamically linked programs should present
8319 only minor differences from debugging statically linked programs.
8321 The `info proc' command will print out information about any process
8322 on an SVR4 system (including the one you are debugging). At the moment,
8323 it prints the address mappings of the process.
8325 If you bring up GDB on another SVR4 system, please send mail to
8326 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8328 * Better dynamic linking support in SunOS
8330 Reading symbols from shared libraries which contain debugging symbols
8331 now works properly. However, there remain issues such as automatic
8332 skipping of `transfer vector' code during function calls, which
8333 make it harder to debug code in a shared library, than to debug the
8334 same code linked statically.
8338 GDB is now using the latest `getopt' routines from the FSF. This
8339 version accepts the -- prefix for options with long names. GDB will
8340 continue to accept the old forms (-option and +option) as well.
8341 Various single letter abbreviations for options have been explicity
8342 added to the option table so that they won't get overshadowed in the
8343 future by other options that begin with the same letter.
8347 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8348 Many assorted bugs have been handled. Many more remain to be handled.
8349 See the various ChangeLog files (primarily in gdb and bfd) for details.
8352 *** Changes in GDB-4.3:
8354 * New machines supported (host and target)
8356 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8357 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8358 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8360 * Almost SCO Unix support
8362 We had hoped to support:
8363 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8364 (except for core file support), but we discovered very late in the release
8365 that it has problems with process groups that render gdb unusable. Sorry
8366 about that. I encourage people to fix it and post the fixes.
8368 * Preliminary ELF and DWARF support
8370 GDB can read ELF object files on System V Release 4, and can handle
8371 debugging records for C, in DWARF format, in ELF files. This support
8372 is preliminary. If you bring up GDB on another SVR4 system, please
8373 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8378 GDB now uses the latest `readline' library. One user-visible change
8379 is that two tabs will list possible command completions, which previously
8380 required typing M-? (meta-question mark, or ESC ?).
8384 The `stepi' bug that many of you noticed has been squashed.
8385 Many bugs in C++ have been handled. Many more remain to be handled.
8386 See the various ChangeLog files (primarily in gdb and bfd) for details.
8388 * State of the MIPS world (in case you wondered):
8390 GDB can understand the symbol tables emitted by the compilers
8391 supplied by most vendors of MIPS-based machines, including DEC. These
8392 symbol tables are in a format that essentially nobody else uses.
8394 Some versions of gcc come with an assembler post-processor called
8395 mips-tfile. This program is required if you want to do source-level
8396 debugging of gcc-compiled programs. I believe FSF does not ship
8397 mips-tfile with gcc version 1, but it will eventually come with gcc
8400 Debugging of g++ output remains a problem. g++ version 1.xx does not
8401 really support it at all. (If you're lucky, you should be able to get
8402 line numbers and stack traces to work, but no parameters or local
8403 variables.) With some work it should be possible to improve the
8406 When gcc version 2 is released, you will have somewhat better luck.
8407 However, even then you will get confusing results for inheritance and
8410 We will eventually provide full debugging of g++ output on
8411 DECstations. This will probably involve some kind of stabs-in-ecoff
8412 encapulation, but the details have not been worked out yet.
8415 *** Changes in GDB-4.2:
8417 * Improved configuration
8419 Only one copy of `configure' exists now, and it is not self-modifying.
8420 Porting BFD is simpler.
8424 The `step' and `next' commands now only stop at the first instruction
8425 of a source line. This prevents the multiple stops that used to occur
8426 in switch statements, for-loops, etc. `Step' continues to stop if a
8427 function that has debugging information is called within the line.
8431 Lots of small bugs fixed. More remain.
8433 * New host supported (not target)
8435 Intel 386 PC clone running Mach i386-none-mach
8438 *** Changes in GDB-4.1:
8440 * Multiple source language support
8442 GDB now has internal scaffolding to handle several source languages.
8443 It determines the type of each source file from its filename extension,
8444 and will switch expression parsing and number formatting to match the
8445 language of the function in the currently selected stack frame.
8446 You can also specifically set the language to be used, with
8447 `set language c' or `set language modula-2'.
8451 GDB now has preliminary support for the GNU Modula-2 compiler,
8452 currently under development at the State University of New York at
8453 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8454 continue through the fall of 1991 and into 1992.
8456 Other Modula-2 compilers are currently not supported, and attempting to
8457 debug programs compiled with them will likely result in an error as the
8458 symbol table is read. Feel free to work on it, though!
8460 There are hooks in GDB for strict type checking and range checking,
8461 in the `Modula-2 philosophy', but they do not currently work.
8465 GDB can now write to executable and core files (e.g. patch
8466 a variable's value). You must turn this switch on, specify
8467 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8468 by assigning a new value to a variable. Modifications take
8471 * Automatic SunOS shared library reading
8473 When you run your program, GDB automatically determines where its
8474 shared libraries (if any) have been loaded, and reads their symbols.
8475 The `share' command is no longer needed. This also works when
8476 examining core files.
8480 You can specify the number of lines that the `list' command shows.
8483 * New machines supported (host and target)
8485 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8486 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8487 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8489 * New hosts supported (not targets)
8491 IBM RT/PC: romp-ibm-aix or rtpc
8493 * New targets supported (not hosts)
8495 AMD 29000 embedded with COFF a29k-none-coff
8496 AMD 29000 embedded with a.out a29k-none-aout
8497 Ultracomputer remote kernel debug a29k-nyu-kern
8499 * New remote interfaces
8505 *** Changes in GDB-4.0:
8509 Wide output is wrapped at good places to make the output more readable.
8511 Gdb now supports cross-debugging from a host machine of one type to a
8512 target machine of another type. Communication with the target system
8513 is over serial lines. The ``target'' command handles connecting to the
8514 remote system; the ``load'' command will download a program into the
8515 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8516 also supports debugging of realtime processes running under VxWorks,
8517 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8518 stub on the target system.
8520 New CPUs supported include the AMD 29000 and Intel 960.
8522 GDB now reads object files and symbol tables via a ``binary file''
8523 library, which allows a single copy of GDB to debug programs of multiple
8524 object file types such as a.out and coff.
8526 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8527 refcard.dvi and refcard.ps are available to format it).
8530 * Control-Variable user interface simplified
8532 All variables that control the operation of the debugger can be set
8533 by the ``set'' command, and displayed by the ``show'' command.
8535 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8536 ``Show prompt'' produces the response:
8537 Gdb's prompt is new-gdb=>.
8539 What follows are the NEW set commands. The command ``help set'' will
8540 print a complete list of old and new set commands. ``help set FOO''
8541 will give a longer description of the variable FOO. ``show'' will show
8542 all of the variable descriptions and their current settings.
8544 confirm on/off: Enables warning questions for operations that are
8545 hard to recover from, e.g. rerunning the program while
8546 it is already running. Default is ON.
8548 editing on/off: Enables EMACS style command line editing
8549 of input. Previous lines can be recalled with
8550 control-P, the current line can be edited with control-B,
8551 you can search for commands with control-R, etc.
8554 history filename NAME: NAME is where the gdb command history
8555 will be stored. The default is .gdb_history,
8556 or the value of the environment variable
8559 history size N: The size, in commands, of the command history. The
8560 default is 256, or the value of the environment variable
8563 history save on/off: If this value is set to ON, the history file will
8564 be saved after exiting gdb. If set to OFF, the
8565 file will not be saved. The default is OFF.
8567 history expansion on/off: If this value is set to ON, then csh-like
8568 history expansion will be performed on
8569 command line input. The default is OFF.
8571 radix N: Sets the default radix for input and output. It can be set
8572 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8573 in the current radix, so "set radix 10" is always a no-op.
8575 height N: This integer value is the number of lines on a page. Default
8576 is 24, the current `stty rows'' setting, or the ``li#''
8577 setting from the termcap entry matching the environment
8580 width N: This integer value is the number of characters on a line.
8581 Default is 80, the current `stty cols'' setting, or the ``co#''
8582 setting from the termcap entry matching the environment
8585 Note: ``set screensize'' is obsolete. Use ``set height'' and
8586 ``set width'' instead.
8588 print address on/off: Print memory addresses in various command displays,
8589 such as stack traces and structure values. Gdb looks
8590 more ``symbolic'' if you turn this off; it looks more
8591 ``machine level'' with it on. Default is ON.
8593 print array on/off: Prettyprint arrays. New convenient format! Default
8596 print demangle on/off: Print C++ symbols in "source" form if on,
8599 print asm-demangle on/off: Same, for assembler level printouts
8602 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8605 * Support for Epoch Environment.
8607 The epoch environment is a version of Emacs v18 with windowing. One
8608 new command, ``inspect'', is identical to ``print'', except that if you
8609 are running in the epoch environment, the value is printed in its own
8613 * Support for Shared Libraries
8615 GDB can now debug programs and core files that use SunOS shared libraries.
8616 Symbols from a shared library cannot be referenced
8617 before the shared library has been linked with the program (this
8618 happens after you type ``run'' and before the function main() is entered).
8619 At any time after this linking (including when examining core files
8620 from dynamically linked programs), gdb reads the symbols from each
8621 shared library when you type the ``sharedlibrary'' command.
8622 It can be abbreviated ``share''.
8624 sharedlibrary REGEXP: Load shared object library symbols for files
8625 matching a unix regular expression. No argument
8626 indicates to load symbols for all shared libraries.
8628 info sharedlibrary: Status of loaded shared libraries.
8633 A watchpoint stops execution of a program whenever the value of an
8634 expression changes. Checking for this slows down execution
8635 tremendously whenever you are in the scope of the expression, but is
8636 quite useful for catching tough ``bit-spreader'' or pointer misuse
8637 problems. Some machines such as the 386 have hardware for doing this
8638 more quickly, and future versions of gdb will use this hardware.
8640 watch EXP: Set a watchpoint (breakpoint) for an expression.
8642 info watchpoints: Information about your watchpoints.
8644 delete N: Deletes watchpoint number N (same as breakpoints).
8645 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8646 enable N: Re-enables watchpoint number N (same as breakpoints).
8649 * C++ multiple inheritance
8651 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8654 * C++ exception handling
8656 Gdb now supports limited C++ exception handling. Besides the existing
8657 ability to breakpoint on an exception handler, gdb can breakpoint on
8658 the raising of an exception (before the stack is peeled back to the
8661 catch FOO: If there is a FOO exception handler in the dynamic scope,
8662 set a breakpoint to catch exceptions which may be raised there.
8663 Multiple exceptions (``catch foo bar baz'') may be caught.
8665 info catch: Lists all exceptions which may be caught in the
8666 current stack frame.
8669 * Minor command changes
8671 The command ``call func (arg, arg, ...)'' now acts like the print
8672 command, except it does not print or save a value if the function's result
8673 is void. This is similar to dbx usage.
8675 The ``up'' and ``down'' commands now always print the frame they end up
8676 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8677 frames without printing.
8679 * New directory command
8681 'dir' now adds directories to the FRONT of the source search path.
8682 The path starts off empty. Source files that contain debug information
8683 about the directory in which they were compiled can be found even
8684 with an empty path; Sun CC and GCC include this information. If GDB can't
8685 find your source file in the current directory, type "dir .".
8687 * Configuring GDB for compilation
8689 For normal use, type ``./configure host''. See README or gdb.texinfo
8692 GDB now handles cross debugging. If you are remotely debugging between
8693 two different machines, type ``./configure host -target=targ''.
8694 Host is the machine where GDB will run; targ is the machine
8695 where the program that you are debugging will run.