1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 12
6 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
7 reading memory tag data for AArch64 MTE from core files generated by
8 the gcore command or the Linux kernel.
10 When a process uses memory-mapped pages protected by memory tags (for
11 example, AArch64 MTE), this additional information will be recorded in
12 the core file in the event of a crash or if GDB generates a core file
13 from the current process state. GDB will show this additional information
14 automatically, or through one of the memory-tag subcommands.
16 * "info breakpoints" now displays enabled breakpoint locations of
17 disabled breakpoints as in the "y-" state. For example:
19 (gdb) info breakpoints
20 Num Type Disp Enb Address What
21 1 breakpoint keep n <MULTIPLE>
22 1.1 y- 0x00000000000011b6 in ...
23 1.2 y- 0x00000000000011c2 in ...
24 1.3 n 0x00000000000011ce in ...
26 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
27 aarch64 architectures.
29 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
31 * Remove support for building against Python 2, it is now only possible to
32 build GDB against Python 3.
34 * DBX mode has been removed.
36 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
37 emit to indicate where a breakpoint should be placed to break in a function
40 * Completion now also offers "NUMBER" for "set" commands that accept
41 a numeric argument and the "unlimited" keyword. For example:
48 (gdb) complete set width
52 * Disassembler styling using libopcodes. GDB now supports
53 disassembler styling using libopcodes. This is only available for
54 some targets (currently x86 and RISC-V). For unsupported targets
55 Python Pygments is still used. For supported targets, libopcodes
56 styling is used by default.
60 maintenance set ignore-prologue-end-flag on|off
61 maintenance show ignore-prologue-end-flag
62 This setting, which is off by default, controls whether GDB ignores the
63 PROLOGUE-END flag from the line-table when skipping prologue. This can be
64 used to force GDB to use prologue analyzers if the line-table is constructed
65 from erroneous debug information.
67 set print nibbles [on|off]
69 This controls whether the 'print/t' command will display binary values
70 in groups of four bits, known as "nibbles". The default is 'off'.
72 maintenance set libopcodes-styling on|off
73 maintenance show libopcodes-styling
74 These can be used to force off libopcodes based styling, the Python
75 Pygments styling will then be used instead.
77 set style disassembler comment
78 show style disassembler comment
79 set style disassembler immediate
80 show style disassembler immediate
81 set style disassembler mnemonic
82 show style disassembler mnemonic
83 set style disassembler register
84 show style disassembler register
85 set style disassembler address
86 show style disassembler address
87 set style disassembler symbol
88 show style disassembler symbol
89 For targets that support libopcodes based styling, these settings
90 control how various aspects of the disassembler output are styled.
91 The 'disassembler address' and 'disassembler symbol' styles are
92 aliases for the 'address' and 'function' styles respectively.
96 maintenance info line-table
97 Add a PROLOGUE-END column to the output which indicates that an
98 entry corresponds to an address where a breakpoint should be placed
99 to be at the first instruction past a function's prologue.
103 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
107 ** GDB will now reformat the doc string for gdb.Command and
108 gdb.Parameter sub-classes to remove unnecessary leading
109 whitespace from each line before using the string as the help
112 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
113 that formats ADDRESS as 'address <symbol+offset>', where symbol is
114 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
115 This is the same format that GDB uses when printing address, symbol,
116 and offset information from the disassembler.
118 ** New function gdb.current_language that returns the name of the
119 current language. Unlike gdb.parameter('language'), this will
122 ** New method gdb.Frame.language that returns the name of the
125 ** New Python API for wrapping GDB's disassembler:
127 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
128 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
129 ARCH is either None or a string containing a bfd architecture
130 name. DISASSEMBLER is registered as a disassembler for
131 architecture ARCH, or for all architectures if ARCH is None.
132 The previous disassembler registered for ARCH is returned, this
133 can be None if no previous disassembler was registered.
135 - gdb.disassembler.Disassembler is the class from which all
136 disassemblers should inherit. Its constructor takes a string,
137 a name for the disassembler, which is currently only used in
138 some debug output. Sub-classes should override the __call__
139 method to perform disassembly, invoking __call__ on this base
140 class will raise an exception.
142 - gdb.disassembler.DisassembleInfo is the class used to describe
143 a single disassembly request from GDB. An instance of this
144 class is passed to the __call__ method of
145 gdb.disassembler.Disassembler and has the following read-only
146 attributes: 'address', and 'architecture', as well as the
147 following method: 'read_memory'.
149 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
150 calls GDB's builtin disassembler on INFO, which is a
151 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
152 optional, its default value is None. If MEMORY_SOURCE is not
153 None then it must be an object that has a 'read_memory' method.
155 - gdb.disassembler.DisassemblerResult is a class that can be used
156 to wrap the result of a call to a Disassembler. It has
157 read-only attributes 'length' and 'string'.
159 ** gdb.Objfile now has an attribute named "is_file". This is True
160 if the objfile comes from a file, and False otherwise.
162 ** New function gdb.print_options that returns a dictionary of the
163 prevailing print options, in the form accepted by
164 gdb.Value.format_string.
166 ** gdb.Value.format_string now uses the format provided by 'print',
167 if it is called during a 'print' or other similar operation.
169 ** gdb.Value.format_string now accepts the 'summary' keyword. This
170 can be used to request a shorter representation of a value, the
171 way that 'set print frame-arguments scalars' does.
173 * New features in the GDB remote stub, GDBserver
175 ** GDBserver is now supported on LoongArch GNU/Linux.
177 * LoongArch floating-point support
179 GDB now supports floating-point on LoongArch GNU/Linux.
181 *** Changes in GDB 12
183 * DBX mode is deprecated, and will be removed in GDB 13
185 * GDB 12 is the last release of GDB that will support building against
186 Python 2. From GDB 13, it will only be possible to build GDB itself
187 with Python 3 support.
189 * The disable-randomization setting now works on Windows.
191 * Improved C++ template support
193 GDB now treats functions/types involving C++ templates like it does function
194 overloads. Users may omit parameter lists to set breakpoints on families of
195 template functions, including types/functions composed of multiple template types:
197 (gdb) break template_func(template_1, int)
199 The above will set breakpoints at every function `template_func' where
200 the first function parameter is any template type named `template_1' and
201 the second function parameter is `int'.
203 TAB completion also gains similar improvements.
205 * The FreeBSD native target now supports async mode.
211 Enable or disable multithreaded symbol loading. This is enabled
212 by default, but passing --disable-threading or --enable-threading=no
213 to configure will disable it.
215 Disabling this can cause a performance penalty when there are a lot of
216 symbols to load, but is useful for debugging purposes.
220 maint set backtrace-on-fatal-signal on|off
221 maint show backtrace-on-fatal-signal
222 This setting is 'on' by default. When 'on' GDB will print a limited
223 backtrace to stderr in the situation where GDB terminates with a
224 fatal signal. This only supported on some platforms where the
225 backtrace and backtrace_symbols_fd functions are available.
227 set source open on|off
229 This setting, which is on by default, controls whether GDB will try
230 to open source code files. Switching this off will stop GDB trying
231 to open and read source code files, which can be useful if the files
232 are located over a slow network connection.
236 These are now deprecated aliases for "set max-value-size" and
237 "show max-value-size".
239 task apply [all | TASK-IDS...] [FLAG]... COMMAND
240 Like "thread apply", but applies COMMAND to Ada tasks.
243 Watchpoints can now be restricted to a specific Ada task.
245 maint set internal-error backtrace on|off
246 maint show internal-error backtrace
247 maint set internal-warning backtrace on|off
248 maint show internal-warning backtrace
249 GDB can now print a backtrace of itself when it encounters either an
250 internal-error, or an internal-warning. This is on by default for
251 internal-error and off by default for internal-warning.
254 Deprecated and replaced by "set logging enabled on|off".
256 set logging enabled on|off
258 These commands set or show whether logging is enabled or disabled.
261 You can now exit GDB by using the new command "exit", in addition to
262 the existing "quit" command.
264 set debug threads on|off
266 Print additional debug messages about thread creation and deletion.
268 set debug linux-nat on|off
270 These new commands replaced the old 'set debug lin-lwp' and 'show
271 debug lin-lwp' respectively. Turning this setting on prints debug
272 messages relating to GDB's handling of native Linux inferiors.
274 maint flush source-cache
275 Flush the contents of the source code cache.
277 maint set gnu-source-highlight enabled on|off
278 maint show gnu-source-highlight enabled
279 Whether GDB should use the GNU Source Highlight library for adding
280 styling to source code. When off, the library will not be used, even
281 when available. When GNU Source Highlight isn't used, or can't add
282 styling to a particular source file, then the Python Pygments
283 library will be used instead.
285 set suppress-cli-notifications (on|off)
286 show suppress-cli-notifications
287 This controls whether printing the notifications is suppressed for CLI.
288 CLI notifications occur when you change the selected context
289 (i.e., the current inferior, thread and/or the frame), or when
290 the program being debugged stops (e.g., because of hitting a
291 breakpoint, completing source-stepping, an interrupt, etc.).
293 set style disassembler enabled on|off
294 show style disassembler enabled
295 If GDB is compiled with Python support, and the Python Pygments
296 package is available, then, when this setting is on, disassembler
297 output will have styling applied.
299 set ada source-charset
300 show ada source-charset
301 Set the character set encoding that is assumed for Ada symbols. Valid
302 values for this follow the values that can be passed to the GNAT
303 compiler via the '-gnati' option. The default is ISO-8859-1.
309 These are the new names for the old 'layout', 'focus', 'refresh',
310 and 'winheight' tui commands respectively. The old names still
311 exist as aliases to these new commands.
315 The new command 'tui window width', and the alias 'winwidth' allow
316 the width of a tui window to be adjusted when windows are laid out
321 Control the display of debug output about GDB's tui.
326 Printing of floating-point values with base-modifying formats like
327 /x has been changed to display the underlying bytes of the value in
328 the desired base. This was GDB's documented behavior, but was never
329 implemented correctly.
332 This command can now print a reply, if the reply includes
333 non-printable characters. Any non-printable characters are printed
334 as escaped hex, e.g. \x?? where '??' is replaces with the value of
335 the non-printable character.
338 The clone-inferior command now ensures that the TTY, CMD and ARGS
339 settings are copied from the original inferior to the new one.
340 All modifications to the environment variables done using the 'set
341 environment' or 'unset environment' commands are also copied to the new
344 set debug lin-lwp on|off
346 These commands have been removed from GDB. The new command 'set
347 debug linux-nat' and 'show debug linux-nat' should be used
351 This command now includes information about the width of the tui
352 windows in its output.
358 These commands are now aliases for the 'tui layout', 'tui focus',
359 'tui refresh', and 'tui window height' commands respectively.
361 * GDB's Ada parser now supports an extension for specifying the exact
362 byte contents of a floating-point literal. This can be useful for
363 setting floating-point registers to a precise value without loss of
364 precision. The syntax is an extension of the based literal syntax.
365 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
366 of the floating-point type, and the "f" is the marker for floating
371 ** The '-add-inferior' with no option flags now inherits the
372 connection of the current inferior, this restores the behaviour of
373 GDB as it was prior to GDB 10.
375 ** The '-add-inferior' command now accepts a '--no-connection'
376 option, which causes the new inferior to start without a
381 GNU/Linux/LoongArch loongarch*-*-linux*
389 ** New function gdb.add_history(), which takes a gdb.Value object
390 and adds the value it represents to GDB's history list. An
391 integer, the index of the new item in the history list, is
394 ** New function gdb.history_count(), which returns the number of
395 values in GDB's value history.
397 ** New gdb.events.gdb_exiting event. This event is called with a
398 gdb.GdbExitingEvent object which has the read-only attribute
399 'exit_code', which contains the value of the GDB exit code. This
400 event is triggered once GDB decides it is going to exit, but
401 before GDB starts to clean up its internal state.
403 ** New function gdb.architecture_names(), which returns a list
404 containing all of the possible Architecture.name() values. Each
407 ** New function gdb.Architecture.integer_type(), which returns an
408 integer type given a size and a signed-ness.
410 ** New gdb.TargetConnection object type that represents a connection
411 (as displayed by the 'info connections' command). A sub-class,
412 gdb.RemoteTargetConnection, is used to represent 'remote' and
413 'extended-remote' connections.
415 ** The gdb.Inferior type now has a 'connection' property which is an
416 instance of gdb.TargetConnection, the connection used by this
417 inferior. This can be None if the inferior has no connection.
419 ** New 'gdb.events.connection_removed' event registry, which emits a
420 'gdb.ConnectionEvent' when a connection is removed from GDB.
421 This event has a 'connection' property, a gdb.TargetConnection
422 object for the connection being removed.
424 ** New gdb.connections() function that returns a list of all
425 currently active connections.
427 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
428 is equivalent to the existing 'maint packet' CLI command; it
429 allows a user specified packet to be sent to the remote target.
431 ** New function gdb.host_charset(), returns a string, which is the
432 name of the current host charset.
434 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
437 ** New gdb.with_parameter(NAME, VALUE). This returns a context
438 manager that temporarily sets the gdb parameter NAME to VALUE,
439 then resets it when the context is exited.
441 ** The gdb.Value.format_string method now takes a 'styling'
442 argument, which is a boolean. When true, the returned string can
443 include escape sequences to apply styling. The styling will only
444 be present if styling is otherwise turned on in GDB (see 'help
445 set styling'). When false, which is the default if the argument
446 is not given, then no styling is applied to the returned string.
448 ** New read-only attribute gdb.InferiorThread.details, which is
449 either a string, containing additional, target specific thread
450 state information, or None, if there is no such additional
453 ** New read-only attribute gdb.Type.is_scalar, which is True for
454 scalar types, and False for all other types.
456 ** New read-only attribute gdb.Type.is_signed. This attribute
457 should only be read when Type.is_scalar is True, and will be True
458 for signed types, and False for all other types. Attempting to
459 read this attribute for non-scalar types will raise a ValueError.
461 ** It is now possible to add GDB/MI commands implemented in Python.
463 * New features in the GDB remote stub, GDBserver
465 ** GDBserver is now supported on OpenRISC GNU/Linux.
467 * New native configurations
469 GNU/Linux/OpenRISC or1k*-*-linux*
471 *** Changes in GDB 11
473 * The 'set disassembler-options' command now supports specifying options
476 * GDB now supports general memory tagging functionality if the underlying
477 architecture supports the proper primitives and hooks. Currently this is
478 enabled only for AArch64 MTE.
482 - Additional information when the inferior crashes with a SIGSEGV caused by
483 a memory tag violation.
485 - A new modifier 'm' for the "x" command, which displays allocation tags for a
486 particular memory range.
488 - Display of memory tag mismatches by "print", for addresses and
489 pointers, if memory tagging is supported by the architecture.
491 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
496 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
498 The MI -break-insert and -dprintf-insert commands now support a
499 new "--qualified" option that makes GDB interpret a specified
500 function name as a complete fully-qualified name. This is the
501 equivalent of the CLI's "break -qualified" and "dprintf
504 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
506 The MI -break-insert and -dprintf-insert commands now support a
507 '--force-condition' flag to forcibly define a condition even when
508 the condition is invalid at all locations of the breakpoint. This
509 is equivalent to the '-force-condition' flag of the CLI's "break"
512 ** '-break-condition --force'
514 The MI -break-condition command now supports a '--force' flag to
515 forcibly define a condition even when the condition is invalid at
516 all locations of the selected breakpoint. This is equivalent to
517 the '-force' flag of the CLI's "cond" command.
519 ** '-file-list-exec-source-files [--group-by-objfile]
520 [--basename | --dirname]
523 The existing -file-list-exec-source-files command now takes an
524 optional REGEXP which is used to filter the source files that are
525 included in the results.
527 By default REGEXP is matched against the full filename of the
528 source file. When one of --basename or --dirname is given then
529 REGEXP is only matched against the specified part of the full
532 When the optional --group-by-objfile flag is used the output
533 format is changed, the results are now a list of object files
534 (executable and libraries) with the source files that are
535 associated with each object file.
537 The results from -file-list-exec-source-files now include a
538 'debug-fully-read' field which takes the value 'true' or 'false'.
539 A 'true' value indicates the source file is from a compilation
540 unit that has had its debug information fully read in by GDB, a
541 value of 'false' indicates GDB has only performed a partial scan
542 of the debug information so far.
544 * GDB now supports core file debugging for x86_64 Cygwin programs.
546 * GDB will now look for the .gdbinit file in a config directory before
547 looking for ~/.gdbinit. The file is searched for in the following
548 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
549 $HOME/.gdbinit. On Apple hosts the search order is instead:
550 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
552 * GDB now supports fixed point types which are described in DWARF
553 as base types with a fixed-point encoding. Additionally, support
554 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
557 For Ada, this allows support for fixed point types without requiring
558 the use of the GNAT encoding (based on information added to the type's
559 name following a GNAT-specific format).
561 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
562 or ~/.gdbearlyinit if these files are present. These files are
563 processed earlier than any of the other initialization files and
564 can affect parts of GDB's startup that previously had already been
565 completed before the initialization files were read, for example
566 styling of the initial GDB greeting.
568 * GDB now has two new options "--early-init-command" and
569 "--early-init-eval-command" with corresponding short options "-eix"
570 and "-eiex" that allow options (that would normally appear in a
571 gdbearlyinit file) to be passed on the command line.
573 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
574 now understood by GDB, and can be used to describe the vector
575 registers of a target. The precise requirements of this register
576 feature are documented in the GDB manual.
578 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
579 supported by GDB and describes a new VPR register from the ARM MVE
580 (Helium) extension. See the GDB manual for more information.
584 ** TUI windows now support mouse actions. The mouse wheel scrolls
585 the appropriate window.
587 ** Key combinations that do not have a specific action on the
588 focused window are passed to GDB. For example, you now can use
589 Ctrl-Left/Ctrl-Right to move between words in the command window
590 regardless of which window is in focus. Previously you would
591 need to focus on the command window for such key combinations to
597 show debug event-loop
598 Control the display of debug output about GDB's event loop.
600 set print memory-tag-violations
601 show print memory-tag-violations
602 Control whether to display additional information about memory tag violations
603 when printing pointers and addresses. Architecture support for memory
604 tagging is required for this option to have an effect.
606 maintenance flush symbol-cache
607 maintenance flush register-cache
608 These new commands are equivalent to the already existing commands
609 'maintenance flush-symbol-cache' and 'flushregs' respectively.
611 maintenance flush dcache
612 A new command to flush the dcache.
614 maintenance info target-sections
615 Print GDB's internal target sections table.
618 Print the JIT code objects in the inferior known to GDB.
620 memory-tag show-logical-tag POINTER
621 Print the logical tag for POINTER.
622 memory-tag with-logical-tag POINTER TAG
623 Print POINTER with logical tag TAG.
624 memory-tag show-allocation-tag ADDRESS
625 Print the allocation tag for ADDRESS.
626 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
627 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
628 memory-tag check POINTER
629 Validate that POINTER's logical tag matches the allocation tag.
631 set startup-quietly on|off
633 When 'on', this causes GDB to act as if "-silent" were passed on the
634 command line. This command needs to be added to an early
635 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
638 set print type hex on|off
640 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
641 and offsets of struct members. When 'off', decimal notation is used.
643 set python ignore-environment on|off
644 show python ignore-environment
645 When 'on', this causes GDB's builtin Python to ignore any
646 environment variables that would otherwise affect how Python
647 behaves. This command needs to be added to an early initialization
648 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
650 set python dont-write-bytecode auto|on|off
651 show python dont-write-bytecode
652 When 'on', this causes GDB's builtin Python to not write any
653 byte-code (.pyc files) to disk. This command needs to be added to
654 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
655 order to affect GDB. When 'off' byte-code will always be written.
656 When set to 'auto' (the default) Python will check the
657 PYTHONDONTWRITEBYTECODE environment variable.
661 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
662 [-force-condition] [if CONDITION]
663 This command would previously refuse setting a breakpoint if the
664 CONDITION expression is invalid at a location. It now accepts and
665 defines the breakpoint if there is at least one location at which
666 the CONDITION is valid. The locations for which the CONDITION is
667 invalid, are automatically disabled. If CONDITION is invalid at all
668 of the locations, setting the breakpoint is still rejected. However,
669 the '-force-condition' flag can be used in this case for forcing GDB to
670 define the breakpoint, making all the current locations automatically
671 disabled. This may be useful if the user knows the condition will
672 become meaningful at a future location, e.g. due to a shared library
675 condition [-force] N COND
676 The behavior of this command is changed the same way for the 'break'
677 command as explained above. The '-force' flag can be used to force
678 GDB into defining the condition even when COND is invalid for all the
679 current locations of breakpoint N.
682 maintenance flush-symbol-cache
683 These commands are deprecated in favor of the new commands
684 'maintenance flush register-cache' and 'maintenance flush
685 symbol-cache' respectively.
687 set style version foreground COLOR
688 set style version background COLOR
689 set style version intensity VALUE
690 Control the styling of GDB's version number text.
693 When the ID parameter is omitted, then this command prints information
694 about the current inferior. When the ID parameter is present, the
695 behavior of the command is unchanged and have the inferior ID become
696 the current inferior.
698 maintenance info sections
699 The ALLOBJ keyword has been replaced with an -all-objects command
700 line flag. It is now possible to filter which sections are printed
701 even when -all-objects is passed.
703 ptype[/FLAGS] TYPE | EXPRESSION
704 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
705 notation is used when printing sizes and offsets of struct members.
706 When '/d' is set, decimal notation is used when printing sizes and
707 offsets of struct members. Default behavior is given by 'show print
711 The info sources command output has been restructured. The results
712 are now based around a list of objfiles (executable and libraries),
713 and for each objfile the source files that are part of that objfile
716 * Removed targets and native configurations
718 ARM Symbian arm*-*-symbianelf*
723 Request the remote to send allocation tags for a particular memory range.
725 Request the remote to store the specified allocation tags to the requested
730 ** Improved support for rvalue reference values:
731 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
732 value-referenced-value procedure now handles rvalue reference
735 ** New procedures for obtaining value variants:
736 value-reference-value, value-rvalue-reference-value and
739 ** Temporary breakpoints can now be created with make-breakpoint and
740 tested for using breakpoint-temporary?.
744 ** Inferior objects now contain a read-only 'connection_num' attribute that
745 gives the connection number as seen in 'info connections' and
748 ** New method gdb.Frame.level() which returns the stack level of the
751 ** New method gdb.PendingFrame.level() which returns the stack level
754 ** When hitting a catchpoint, the Python API will now emit a
755 gdb.BreakpointEvent rather than a gdb.StopEvent. The
756 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
758 ** Python TUI windows can now receive mouse click events. If the
759 Window object implements the click method, it is called for each
760 mouse click event in this window.
762 *** Changes in GDB 10
764 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
765 and "org.gnu.gdb.arc.aux". The old names are still supported but
766 must be considered obsolete. They will be deprecated after some
769 * Help and apropos commands will now show the documentation of a
770 command only once, even if that command has one or more aliases.
771 These commands now show the command name, then all of its aliases,
772 and finally the description of the command.
774 * 'help aliases' now shows only the user defined aliases. GDB predefined
775 aliases are shown together with their aliased command.
777 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
778 debugging information as well as source code.
780 When built with debuginfod, GDB can automatically query debuginfod
781 servers for the separate debug files and source code of the executable
784 To build GDB with debuginfod, pass --with-debuginfod to configure (this
785 requires libdebuginfod, the debuginfod client library).
787 debuginfod is distributed with elfutils, starting with version 0.178.
789 You can get the latest version from https://sourceware.org/elfutils.
791 * Multi-target debugging support
793 GDB now supports debugging multiple target connections
794 simultaneously. For example, you can now have each inferior
795 connected to different remote servers running in different machines,
796 or have one inferior debugging a local native process, an inferior
797 debugging a core dump, etc.
799 This support is experimental and comes with some limitations -- you
800 can only resume multiple targets simultaneously if all targets
801 support non-stop mode, and all remote stubs or servers must support
802 the same set of remote protocol features exactly. See also "info
803 connections" and "add-inferior -no-connection" below, and "maint set
804 target-non-stop" in the user manual.
806 * New features in the GDB remote stub, GDBserver
808 ** GDBserver is now supported on ARC GNU/Linux.
810 ** GDBserver is now supported on RISC-V GNU/Linux.
812 ** GDBserver no longer supports these host triplets:
823 i[34567]86-*-mingw32ce*
825 * Debugging MS-Windows processes now sets $_exitsignal when the
826 inferior is terminated by a signal, instead of setting $_exitcode.
828 * Multithreaded symbol loading has now been enabled by default on systems
829 that support it (see entry for GDB 9, below), providing faster
830 performance for programs with many symbols.
832 * The $_siginfo convenience variable now also works on Windows targets,
833 and will display the EXCEPTION_RECORD of the last handled exception.
835 * TUI windows can now be arranged horizontally.
837 * The command history filename can now be set to the empty string
838 either using 'set history filename' or by setting 'GDBHISTFILE=' in
839 the environment. The effect of setting this filename to the empty
840 string is that GDB will not try to load any previous command
843 * On Windows targets, it is now possible to debug 32-bit programs with a
848 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
849 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
850 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
851 running process, this new option indicates whether to detect
852 a mismatch between the current executable file loaded by GDB and the
853 executable file used to start the process. If 'ask', the default,
854 display a warning and ask the user whether to load the process
855 executable file; if 'warn', just display a warning; if 'off', don't
856 attempt to detect a mismatch.
858 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
859 Define a new TUI layout, specifying its name and the windows that
862 maintenance print xml-tdesc [FILE]
863 Prints the current target description as an XML document. If the
864 optional FILE is provided (which is an XML target description) then
865 the target description is read from FILE into GDB, and then
868 maintenance print core-file-backed-mappings
869 Prints file-backed mappings loaded from a core file's note section.
870 Output is expected to be similar to that of "info proc mappings".
872 set debug fortran-array-slicing on|off
873 show debug fortran-array-slicing
874 Print debugging when taking slices of Fortran arrays.
876 set fortran repack-array-slices on|off
877 show fortran repack-array-slices
878 When taking slices from Fortran arrays and strings, if the slice is
879 non-contiguous within the original value then, when this option is
880 on, the new value will be repacked into a single contiguous value.
881 When this option is off, then the value returned will consist of a
882 descriptor that describes the slice within the memory of the
883 original parent value.
887 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
888 The alias command can now specify default args for an alias.
889 GDB automatically prepends the alias default args to the argument list
890 provided explicitly by the user.
891 For example, to have a backtrace with full details, you can define
893 'alias bt_ALL = backtrace -entry-values both -frame-arg all
894 -past-main -past-entry -full'.
895 Alias default arguments can also use a set of nested 'with' commands,
896 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
897 defines the alias pp10 that will pretty print a maximum of 10 elements
898 of the given expression (if the expression is an array).
902 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
908 ** gdb.register_window_type can be used to implement new TUI windows
911 ** Dynamic types can now be queried. gdb.Type has a new attribute,
912 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
913 field of a dynamic type may have None for its "bitpos" attribute
916 ** Commands written in Python can be in the "TUI" help class by
917 registering with the new constant gdb.COMMAND_TUI.
919 ** New method gdb.PendingFrame.architecture () to retrieve the
920 architecture of the pending frame.
922 ** New gdb.Architecture.registers method that returns a
923 gdb.RegisterDescriptorIterator object, an iterator that returns
924 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
925 way to query the registers available for an architecture.
927 ** New gdb.Architecture.register_groups method that returns a
928 gdb.RegisterGroupIterator object, an iterator that returns
929 gdb.RegisterGroup objects. The new RegisterGroup is a way to
930 discover the available register groups.
934 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
936 ** Procedures 'memory-port-read-buffer-size',
937 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
938 and 'set-memory-port-write-buffer-size!' are deprecated. When
939 using Guile 2.2 and later, users who need to control the size of
940 a memory port's internal buffer can use the 'setvbuf' procedure.
944 * 'thread-exited' event is now available in the annotations interface.
946 * New built-in convenience variables $_gdb_major and $_gdb_minor
947 provide the GDB version. They are handy for conditionally using
948 features available only in or since specific GDB versions, in
949 scripts that should work error-free with many different versions,
950 such as in system-wide init files.
952 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
953 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
954 of the GDB settings and the GDB maintenance settings. They are handy
955 for changing the logic of user defined commands depending on the
956 current GDB settings.
958 * GDB now supports Thread Local Storage (TLS) variables on several
959 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
960 architectures require kernel changes. TLS is not yet supported for
961 amd64 and i386 process core dumps.
963 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
964 addresses that required unmasking are shown in the backtrace with the
967 * Two new convenience functions $_cimag and $_creal that extract the
968 imaginary and real parts respectively from complex numbers.
970 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
971 provide the exitcode or exit status of the shell commands launched by
972 GDB commands such as "shell", "pipe" and "make".
974 * The command define-prefix can now define user defined prefix commands.
975 User defined commands can now be defined using these user defined prefix
978 * Command names can now use the . character.
980 * The RX port now supports XML target descriptions.
982 * GDB now shows the Ada task names at more places, e.g. in task switching
985 * GDB can now be compiled with Python 3 on Windows.
987 * New convenience variable $_ada_exception holds the address of the
988 Ada exception being thrown. This is set by Ada-related catchpoints.
990 * GDB can now place breakpoints on nested functions and subroutines in
991 Fortran code. The '::' operator can be used between parent and
992 child scopes when placing breakpoints, for example:
994 (gdb) break outer_function::inner_function
996 The 'outer_function::' prefix is only needed if 'inner_function' is
997 not visible in the current scope.
999 * In addition to the system-wide gdbinit file, if configured with
1000 --with-system-gdbinit-dir, GDB will now also load files in that directory
1001 as system gdbinit files, unless the -nx or -n flag is provided. Files
1002 with extensions .gdb, .py and .scm are supported as long as GDB was
1003 compiled with support for that language.
1005 * GDB now supports multithreaded symbol loading for higher performance.
1006 This feature is still in testing, so it is disabled by default. You
1007 can turn it on using 'maint set worker-threads unlimited'.
1011 ** The gdb.Value type has a new method 'format_string' which returns a
1012 string representing the value. The formatting is controlled by the
1013 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1014 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1015 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1017 ** gdb.Type has a new property 'objfile' which returns the objfile the
1018 type was defined in.
1020 ** The frame information printed by the python frame filtering code
1021 is now consistent with what the 'backtrace' command prints when
1022 there are no filters, or when the 'backtrace' '-no-filters' option
1025 ** The new function gdb.lookup_static_symbol can be used to look up
1026 symbols with static linkage.
1028 ** The new function gdb.lookup_static_symbols can be used to look up
1029 all static symbols with static linkage.
1031 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1032 'lookup_static_symbol' to lookup a symbol from this objfile only.
1034 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1035 this block (e.g. block['local_variable']).
1039 | [COMMAND] | SHELL_COMMAND
1040 | -d DELIM COMMAND DELIM SHELL_COMMAND
1041 pipe [COMMAND] | SHELL_COMMAND
1042 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1043 Executes COMMAND and sends its output to SHELL_COMMAND.
1044 With no COMMAND, repeat the last executed command
1045 and send its output to SHELL_COMMAND.
1047 define-prefix COMMAND
1048 Define or mark a command as a user-defined prefix command.
1050 with SETTING [VALUE] [-- COMMAND]
1051 w SETTING [VALUE] [-- COMMAND]
1052 Temporarily set SETTING, run COMMAND, and restore SETTING.
1053 Usage: with SETTING -- COMMAND
1054 With no COMMAND, repeats the last executed command.
1055 SETTING is any GDB setting you can change with the "set"
1056 subcommands. For example, 'with language c -- print someobj'
1057 temporarily switches to the C language in order to print someobj.
1058 Settings can be combined: 'w lang c -- w print elements unlimited --
1059 usercmd' switches to the C language and runs usercmd with no limit
1060 of array elements to print.
1062 maint with SETTING [VALUE] [-- COMMAND]
1063 Like "with", but works with "maintenance set" settings.
1065 set may-call-functions [on|off]
1066 show may-call-functions
1067 This controls whether GDB will attempt to call functions in
1068 the program, such as with expressions in the print command. It
1069 defaults to on. Calling functions in the program being debugged
1070 can have undesired side effects. It is now possible to forbid
1071 such function calls. If function calls are forbidden, GDB will throw
1072 an error when a command (such as print expression) calls a function
1075 set print finish [on|off]
1077 This controls whether the `finish' command will display the value
1078 that is returned by the current function. When `off', the value is
1079 still entered into the value history, but it is not printed. The
1083 show print max-depth
1084 Allows deeply nested structures to be simplified when printing by
1085 replacing deeply nested parts (beyond the max-depth) with ellipses.
1086 The default max-depth is 20, but this can be set to unlimited to get
1087 the old behavior back.
1089 set print raw-values [on|off]
1090 show print raw-values
1091 By default, GDB applies the enabled pretty printers when printing a
1092 value. This allows to ignore the enabled pretty printers for a series
1093 of commands. The default is 'off'.
1095 set logging debugredirect [on|off]
1096 By default, GDB debug output will go to both the terminal and the logfile.
1097 Set if you want debug output to go only to the log file.
1099 set style title foreground COLOR
1100 set style title background COLOR
1101 set style title intensity VALUE
1102 Control the styling of titles.
1104 set style highlight foreground COLOR
1105 set style highlight background COLOR
1106 set style highlight intensity VALUE
1107 Control the styling of highlightings.
1109 maint set worker-threads
1110 maint show worker-threads
1111 Control the number of worker threads that can be used by GDB. The
1112 default is 0. "unlimited" lets GDB choose a number that is
1113 reasonable. Currently worker threads are only used when demangling
1114 the names of linker symbols.
1116 set style tui-border foreground COLOR
1117 set style tui-border background COLOR
1118 Control the styling of TUI borders.
1120 set style tui-active-border foreground COLOR
1121 set style tui-active-border background COLOR
1122 Control the styling of the active TUI border.
1124 maint set test-settings KIND
1125 maint show test-settings KIND
1126 A set of commands used by the testsuite for exercising the settings
1129 maint set tui-resize-message [on|off]
1130 maint show tui-resize-message
1131 Control whether GDB prints a message each time the terminal is
1132 resized when in TUI mode. This is primarily useful for testing the
1135 set print frame-info [short-location|location|location-and-address
1136 |source-and-location|source-line|auto]
1137 show print frame-info
1138 This controls what frame information is printed by the commands printing
1139 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1140 'frame', 'stepi'. The python frame filtering also respect this setting.
1141 The 'backtrace' '-frame-info' option can override this global setting.
1143 set tui compact-source
1144 show tui compact-source
1146 Enable the "compact" display mode for the TUI source window. The
1147 compact display uses only as much space as is needed for the line
1148 numbers in the current file, and only a single space to separate the
1149 line numbers from the source.
1151 info modules [-q] [REGEXP]
1152 Return a list of Fortran modules matching REGEXP, or all modules if
1155 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1156 Return a list of functions within all modules, grouped by module.
1157 The list of functions can be restricted with the optional regular
1158 expressions. MODULE_REGEXP matches against the module name,
1159 TYPE_REGEXP matches against the function type signature, and REGEXP
1160 matches against the function name.
1162 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1163 Return a list of variables within all modules, grouped by module.
1164 The list of variables can be restricted with the optional regular
1165 expressions. MODULE_REGEXP matches against the module name,
1166 TYPE_REGEXP matches against the variable type, and REGEXP matches
1167 against the variable name.
1169 set debug remote-packet-max-chars
1170 show debug remote-packet-max-chars
1171 Controls the number of characters to output in a remote packet when using
1173 The default is 512 bytes.
1176 Lists the target connections currently in use.
1181 The "help" command uses the title style to enhance the
1182 readibility of its output by styling the classes and
1186 Similarly to "help", the "apropos" command also uses the
1187 title style for the command names. "apropos" accepts now
1188 a flag "-v" (verbose) to show the full documentation
1189 of matching commands and to use the highlight style to mark
1190 the documentation parts matching REGEXP.
1194 The GDB printf and eval commands can now print C-style and Ada-style
1195 string convenience variables without calling functions in the program.
1196 This allows to do formatted printing of strings without having
1197 a running inferior, or when debugging a core dump.
1199 info sources [-dirname | -basename] [--] [REGEXP]
1200 This command has now optional arguments to only print the files
1201 whose names match REGEXP. The arguments -dirname and -basename
1202 allow to restrict matching respectively to the dirname and basename
1206 The "show style" and its subcommands are now styling
1207 a style name in their output using its own style, to help
1208 the user visualize the different styles.
1210 set print frame-arguments
1211 The new value 'presence' indicates to only indicate the presence of
1212 arguments using ..., instead of printing argument names and values.
1214 set print raw-frame-arguments
1215 show print raw-frame-arguments
1217 These commands replace the similarly-named "set/show print raw
1218 frame-arguments" commands (now with a dash instead of a space). The
1219 old commands are now deprecated and may be removed in a future
1222 add-inferior [-no-connection]
1223 The add-inferior command now supports a "-no-connection" flag that
1224 makes the new inferior start with no target connection associated.
1225 By default, the new inferior inherits the target connection of the
1226 current inferior. See also "info connections".
1229 This command's output now includes a new "Connection" column
1230 indicating which target connection an inferior is bound to. See
1231 "info connections" above.
1233 maint test-options require-delimiter
1234 maint test-options unknown-is-error
1235 maint test-options unknown-is-operand
1236 maint show test-options-completion-result
1237 Commands used by the testsuite to validate the command options
1240 focus, winheight, +, -, >, <
1241 These commands are now case-sensitive.
1243 * New command options, command completion
1245 GDB now has a standard infrastructure to support dash-style command
1246 options ('-OPT'). One benefit is that commands that use it can
1247 easily support completion of command line arguments. Try "CMD
1248 -[TAB]" or "help CMD" to find options supported by a command. Over
1249 time, we intend to migrate most commands to this infrastructure. A
1250 number of commands got support for new command options in this
1253 ** The "print" and "compile print" commands now support a number of
1254 options that allow overriding relevant global print settings as
1255 set by "set print" subcommands:
1259 -array-indexes [on|off]
1260 -elements NUMBER|unlimited
1264 -raw-values [on|off]
1265 -repeats NUMBER|unlimited
1266 -static-members [on|off]
1271 Note that because the "print"/"compile print" commands accept
1272 arbitrary expressions which may look like options (including
1273 abbreviations), if you specify any command option, then you must
1274 use a double dash ("--") to mark the end of argument processing.
1276 ** The "backtrace" command now supports a number of options that
1277 allow overriding relevant global print settings as set by "set
1278 backtrace" and "set print" subcommands:
1280 -entry-values no|only|preferred|if-needed|both|compact|default
1281 -frame-arguments all|scalars|none
1282 -raw-frame-arguments [on|off]
1283 -frame-info auto|source-line|location|source-and-location
1284 |location-and-address|short-location
1286 -past-entry [on|off]
1288 In addition, the full/no-filters/hide qualifiers are now also
1289 exposed as command options too:
1295 ** The "frame apply", "tfaas" and "faas" commands similarly now
1296 support the following options:
1299 -past-entry [on|off]
1301 ** The new "info sources" options -dirname and -basename options
1302 are using the standard '-OPT' infrastructure.
1304 All options above can also be abbreviated. The argument of boolean
1305 (on/off) options can be 0/1 too, and also the argument is assumed
1306 "on" if omitted. This allows writing compact command invocations,
1309 (gdb) p -ra -p -o 0 -- *myptr
1311 The above is equivalent to:
1313 (gdb) print -raw-values -pretty -object off -- *myptr
1315 ** The "info types" command now supports the '-q' flag to disable
1316 printing of some header information in a similar fashion to "info
1317 variables" and "info functions".
1319 ** The "info variables", "info functions", and "whereis" commands
1320 now take a '-n' flag that excludes non-debug symbols (symbols
1321 from the symbol table, not from the debug info such as DWARF)
1324 * Completion improvements
1326 ** GDB can now complete the options of the "thread apply all" and
1327 "taas" commands, and their "-ascending" option can now be
1330 ** GDB can now complete the options of the "info threads", "info
1331 functions", "info variables", "info locals", and "info args"
1334 ** GDB can now complete the options of the "compile file" and
1335 "compile code" commands. The "compile file" command now
1336 completes on filenames.
1338 ** GDB can now complete the backtrace command's
1339 "full/no-filters/hide" qualifiers.
1341 * In settings, you can now abbreviate "unlimited".
1343 E.g., "set print elements u" is now equivalent to "set print
1344 elements unlimited".
1349 This lists all the possible completions for the rest of the line, if it
1350 were to be given as a command itself. This is intended for use by MI
1351 frontends in cases when separate CLI and MI channels cannot be used.
1353 -catch-throw, -catch-rethrow, and -catch-catch
1354 These can be used to catch C++ exceptions in a similar fashion to
1355 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1357 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1358 These commands are the MI equivalent of the CLI commands 'info
1359 functions', 'info types', and 'info variables' respectively.
1361 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1364 -symbol-info-module-functions and -symbol-info-module-variables.
1365 These commands are the MI equivalent of the CLI commands 'info
1366 module functions' and 'info module variables'.
1370 ** The default version of the MI interpreter is now 3 (-i=mi3).
1372 ** The output of information about multi-location breakpoints (which is
1373 syntactically incorrect in MI 2) has changed in MI 3. This affects
1374 the following commands and events:
1378 - =breakpoint-created
1379 - =breakpoint-modified
1381 The -fix-multi-location-breakpoint-output command can be used to enable
1382 this behavior with previous MI versions.
1384 ** Backtraces and frames include a new optional field addr_flags which is
1385 given after the addr field. On AArch64 this contains PAC if the address
1386 has been masked in the frame. On all other targets the field is not
1391 The testsuite now creates the files gdb.cmd (containing the arguments
1392 used to launch GDB) and gdb.in (containing all the commands sent to
1393 GDB) in the output directory for each test script. Multiple invocations
1394 are appended with .1, .2, .3 etc.
1396 * Building GDB and GDBserver now requires GNU make >= 3.82.
1398 Using another implementation of the make program or an earlier version of
1399 GNU make to build GDB or GDBserver is not supported.
1401 * Building GDB now requires GNU readline >= 7.0.
1403 GDB now bundles GNU readline 8.0, but if you choose to use
1404 --with-system-readline, only readline >= 7.0 can be used.
1406 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1407 from .inputrc to bind keys in this keymap. This feature is only
1408 available when gdb is built against GNU readline 8.0 or later.
1410 * Removed targets and native configurations
1412 GDB no longer supports debugging the Cell Broadband Engine. This includes
1413 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1414 of Cell/B.E. applications that use both the PPU and SPU architectures.
1420 * Removed targets and native configurations
1422 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1423 sparc*-*-solaris2.10
1425 *** Changes in GDB 8.3
1427 * GDB and GDBserver now support access to additional registers on
1428 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1431 * GDB now has experimental support for the compilation and injection of
1432 C++ source code into the inferior. This beta release does not include
1433 support for several language features, such as templates, constructors,
1436 This feature requires GCC 7.1 or higher built with libcp1.so
1439 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1440 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1441 'ADDRESS:PORT' method.
1443 * DWARF index cache: GDB can now automatically save indices of DWARF
1444 symbols on disk to speed up further loading of the same binaries.
1446 * Ada task switching is now supported on aarch64-elf targets when
1447 debugging a program using the Ravenscar Profile. For more information,
1448 see the "Tasking Support when using the Ravenscar Profile" section
1449 in the GDB user manual.
1451 * GDB in batch mode now exits with status 1 if the last command to be
1454 * The RISC-V target now supports target descriptions.
1456 * System call catchpoints now support system call aliases on FreeBSD.
1457 When the ABI of a system call changes in FreeBSD, this is
1458 implemented by leaving a compatibility system call using the old ABI
1459 at the existing number and allocating a new system call number for
1460 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1461 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1462 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1463 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1464 so that a system call catchpoint for the 'kevent' system call will
1465 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1466 binaries. This ensures that 'kevent' system calls are caught for
1467 binaries using either the old or new ABIs.
1469 * Terminal styling is now available for the CLI and the TUI. GNU
1470 Source Highlight can additionally be used to provide styling of
1471 source code snippets. See the "set style" commands, below, for more
1474 * Removed support for old demangling styles arm, edg, gnu, hp and
1479 set debug compile-cplus-types
1480 show debug compile-cplus-types
1481 Control the display of debug output about type conversion in the
1482 C++ compile feature. Commands have no effect while compiling
1483 for other languages.
1487 Control whether debug output about files/functions skipping is
1490 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1491 Apply a command to some frames.
1492 FLAG arguments allow to control what output to produce and how to handle
1493 errors raised when applying COMMAND to a frame.
1496 Apply a command to all threads (ignoring errors and empty output).
1497 Shortcut for 'thread apply all -s COMMAND'.
1500 Apply a command to all frames (ignoring errors and empty output).
1501 Shortcut for 'frame apply all -s COMMAND'.
1504 Apply a command to all frames of all threads (ignoring errors and empty
1506 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1508 maint set dwarf unwinders (on|off)
1509 maint show dwarf unwinders
1510 Control whether DWARF unwinders can be used.
1513 Display a list of open files for a process.
1517 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1518 These commands all now take a frame specification which
1519 is either a frame level, or one of the keywords 'level', 'address',
1520 'function', or 'view' followed by a parameter. Selecting a frame by
1521 address, or viewing a frame outside the current backtrace now
1522 requires the use of a keyword. Selecting a frame by level is
1523 unchanged. The MI comment "-stack-select-frame" is unchanged.
1525 target remote FILENAME
1526 target extended-remote FILENAME
1527 If FILENAME is a Unix domain socket, GDB will attempt to connect
1528 to this socket instead of opening FILENAME as a character device.
1530 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1531 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1532 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1533 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1534 These commands can now print only the searched entities
1535 matching the provided regexp(s), giving a condition
1536 on the entity names or entity types. The flag -q disables
1537 printing headers or informations messages.
1543 These commands now determine the syntax for the shown entities
1544 according to the language chosen by `set language'. In particular,
1545 `set language auto' means to automatically choose the language of
1548 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1549 The 'thread apply' command accepts new FLAG arguments.
1550 FLAG arguments allow to control what output to produce and how to handle
1551 errors raised when applying COMMAND to a thread.
1553 set tui tab-width NCHARS
1554 show tui tab-width NCHARS
1555 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1557 set style enabled [on|off]
1559 Enable or disable terminal styling. Styling is enabled by default
1560 on most hosts, but disabled by default when in batch mode.
1562 set style sources [on|off]
1564 Enable or disable source code styling. Source code styling is
1565 enabled by default, but only takes effect if styling in general is
1566 enabled, and if GDB was linked with GNU Source Highlight.
1568 set style filename foreground COLOR
1569 set style filename background COLOR
1570 set style filename intensity VALUE
1571 Control the styling of file names.
1573 set style function foreground COLOR
1574 set style function background COLOR
1575 set style function intensity VALUE
1576 Control the styling of function names.
1578 set style variable foreground COLOR
1579 set style variable background COLOR
1580 set style variable intensity VALUE
1581 Control the styling of variable names.
1583 set style address foreground COLOR
1584 set style address background COLOR
1585 set style address intensity VALUE
1586 Control the styling of addresses.
1590 ** The '-data-disassemble' MI command now accepts an '-a' option to
1591 disassemble the whole function surrounding the given program
1592 counter value or function name. Support for this feature can be
1593 verified by using the "-list-features" command, which should
1594 contain "data-disassemble-a-option".
1596 ** Command responses and notifications that include a frame now include
1597 the frame's architecture in a new "arch" attribute.
1599 * New native configurations
1601 GNU/Linux/RISC-V riscv*-*-linux*
1602 FreeBSD/riscv riscv*-*-freebsd*
1606 GNU/Linux/RISC-V riscv*-*-linux*
1607 CSKY ELF csky*-*-elf
1608 CSKY GNU/LINUX csky*-*-linux
1609 FreeBSD/riscv riscv*-*-freebsd*
1611 GNU/Linux/OpenRISC or1k*-*-linux*
1615 GDB no longer supports native debugging on versions of MS-Windows
1620 ** GDB no longer supports Python versions less than 2.6.
1622 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1623 space associated to that inferior.
1625 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1626 of objfiles associated to that program space.
1628 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1629 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1632 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1633 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1634 correct and did not work properly.
1636 ** The gdb.Value type has a new constructor, which is used to construct a
1637 gdb.Value from a Python buffer object and a gdb.Type.
1643 Enable or disable the undefined behavior sanitizer. This is
1644 disabled by default, but passing --enable-ubsan=yes or
1645 --enable-ubsan=auto to configure will enable it. Enabling this can
1646 cause a performance penalty. The undefined behavior sanitizer was
1647 first introduced in GCC 4.9.
1649 *** Changes in GDB 8.2
1651 * The 'set disassembler-options' command now supports specifying options
1652 for the MIPS target.
1654 * The 'symbol-file' command now accepts an '-o' option to add a relative
1655 offset to all sections.
1657 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1658 a relative offset to all sections, but it allows to override the load
1659 address of individual sections using '-s'.
1661 * The 'add-symbol-file' command no longer requires the second argument
1662 (address of the text section).
1664 * The endianness used with the 'set endian auto' mode in the absence of
1665 an executable selected for debugging is now the last endianness chosen
1666 either by one of the 'set endian big' and 'set endian little' commands
1667 or by inferring from the last executable used, rather than the startup
1670 * The pager now allows a "c" response, meaning to disable the pager
1671 for the rest of the current command.
1673 * The commands 'info variables/functions/types' now show the source line
1674 numbers of symbol definitions when available.
1676 * 'info proc' now works on running processes on FreeBSD systems and core
1677 files created on FreeBSD systems.
1679 * C expressions can now use _Alignof, and C++ expressions can now use
1682 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1683 the vector length while the process is running.
1689 Control display of debugging info regarding the FreeBSD native target.
1691 set|show varsize-limit
1692 This new setting allows the user to control the maximum size of Ada
1693 objects being printed when those objects have a variable type,
1694 instead of that maximum size being hardcoded to 65536 bytes.
1696 set|show record btrace cpu
1697 Controls the processor to be used for enabling errata workarounds for
1698 branch trace decode.
1700 maint check libthread-db
1701 Run integrity checks on the current inferior's thread debugging
1704 maint set check-libthread-db (on|off)
1705 maint show check-libthread-db
1706 Control whether to run integrity checks on inferior specific thread
1707 debugging libraries as they are loaded. The default is not to
1708 perform such checks.
1712 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1714 ** The commands attached to a breakpoint can be set by assigning to
1715 the breakpoint's "commands" field.
1717 ** gdb.execute can now execute multi-line gdb commands.
1719 ** The new functions gdb.convenience_variable and
1720 gdb.set_convenience_variable can be used to get and set the value
1721 of convenience variables.
1723 ** A gdb.Parameter will no longer print the "set" help text on an
1724 ordinary "set"; instead by default a "set" will be silent unless
1725 the get_set_string method returns a non-empty string.
1729 RiscV ELF riscv*-*-elf
1731 * Removed targets and native configurations
1733 m88k running OpenBSD m88*-*-openbsd*
1734 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1735 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1736 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1738 * Aarch64/Linux hardware watchpoints improvements
1740 Hardware watchpoints on unaligned addresses are now properly
1741 supported when running Linux kernel 4.10 or higher: read and access
1742 watchpoints are no longer spuriously missed, and all watchpoints
1743 lengths between 1 and 8 bytes are supported. On older kernels,
1744 watchpoints set on unaligned addresses are no longer missed, with
1745 the tradeoff that there is a possibility of false hits being
1750 --enable-codesign=CERT
1751 This can be used to invoke "codesign -s CERT" after building gdb.
1752 This option is useful on macOS, where code signing is required for
1753 gdb to work properly.
1755 --disable-gdbcli has been removed
1756 This is now silently accepted, but does nothing.
1758 *** Changes in GDB 8.1
1760 * GDB now supports dynamically creating arbitrary register groups specified
1761 in XML target descriptions. This allows for finer grain grouping of
1762 registers on systems with a large amount of registers.
1764 * The 'ptype' command now accepts a '/o' flag, which prints the
1765 offsets and sizes of fields in a struct, like the pahole(1) tool.
1767 * New "--readnever" command line option instructs GDB to not read each
1768 symbol file's symbolic debug information. This makes startup faster
1769 but at the expense of not being able to perform symbolic debugging.
1770 This option is intended for use cases where symbolic debugging will
1771 not be used, e.g., when you only need to dump the debuggee's core.
1773 * GDB now uses the GNU MPFR library, if available, to emulate target
1774 floating-point arithmetic during expression evaluation when the target
1775 uses different floating-point formats than the host. At least version
1776 3.1 of GNU MPFR is required.
1778 * GDB now supports access to the guarded-storage-control registers and the
1779 software-based guarded-storage broadcast control registers on IBM z14.
1781 * On Unix systems, GDB now supports transmitting environment variables
1782 that are to be set or unset to GDBserver. These variables will
1783 affect the environment to be passed to the remote inferior.
1785 To inform GDB of environment variables that are to be transmitted to
1786 GDBserver, use the "set environment" command. Only user set
1787 environment variables are sent to GDBserver.
1789 To inform GDB of environment variables that are to be unset before
1790 the remote inferior is started by the GDBserver, use the "unset
1791 environment" command.
1793 * Completion improvements
1795 ** GDB can now complete function parameters in linespecs and
1796 explicit locations without quoting. When setting breakpoints,
1797 quoting around functions names to help with TAB-completion is
1798 generally no longer necessary. For example, this now completes
1801 (gdb) b function(in[TAB]
1802 (gdb) b function(int)
1804 Related, GDB is no longer confused with completing functions in
1805 C++ anonymous namespaces:
1808 (gdb) b (anonymous namespace)::[TAB][TAB]
1809 (anonymous namespace)::a_function()
1810 (anonymous namespace)::b_function()
1812 ** GDB now has much improved linespec and explicit locations TAB
1813 completion support, that better understands what you're
1814 completing and offers better suggestions. For example, GDB no
1815 longer offers data symbols as possible completions when you're
1816 setting a breakpoint.
1818 ** GDB now TAB-completes label symbol names.
1820 ** The "complete" command now mimics TAB completion accurately.
1822 * New command line options (gcore)
1825 Dump all memory mappings.
1827 * Breakpoints on C++ functions are now set on all scopes by default
1829 By default, breakpoints on functions/methods are now interpreted as
1830 specifying all functions with the given name ignoring missing
1831 leading scopes (namespaces and classes).
1833 For example, assuming a C++ program with symbols named:
1838 both commands "break func()" and "break B::func()" set a breakpoint
1841 You can use the new flag "-qualified" to override this. This makes
1842 GDB interpret the specified function name as a complete
1843 fully-qualified name instead. For example, using the same C++
1844 program, the "break -q B::func" command sets a breakpoint on
1845 "B::func", only. A parameter has been added to the Python
1846 gdb.Breakpoint constructor to achieve the same result when creating
1847 a breakpoint from Python.
1849 * Breakpoints on functions marked with C++ ABI tags
1851 GDB can now set breakpoints on functions marked with C++ ABI tags
1852 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1853 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1855 Functions with a C++11 abi tag are demangled/displayed like this:
1857 function[abi:cxx11](int)
1860 You can now set a breakpoint on such functions simply as if they had
1863 (gdb) b function(int)
1865 Or if you need to disambiguate between tags, like:
1867 (gdb) b function[abi:other_tag](int)
1869 Tab completion was adjusted accordingly as well.
1873 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1874 gdb.new_thread are emitted. See the manual for further
1875 description of these.
1877 ** A new function, "gdb.rbreak" has been added to the Python API.
1878 This function allows the setting of a large number of breakpoints
1879 via a regex pattern in Python. See the manual for further details.
1881 ** Python breakpoints can now accept explicit locations. See the
1882 manual for a further description of this feature.
1885 * New features in the GDB remote stub, GDBserver
1887 ** GDBserver is now able to start inferior processes with a
1888 specified initial working directory.
1890 The user can set the desired working directory to be used from
1891 GDB using the new "set cwd" command.
1893 ** New "--selftest" command line option runs some GDBserver self
1894 tests. These self tests are disabled in releases.
1896 ** On Unix systems, GDBserver now does globbing expansion and variable
1897 substitution in inferior command line arguments.
1899 This is done by starting inferiors using a shell, like GDB does.
1900 See "set startup-with-shell" in the user manual for how to disable
1901 this from GDB when using "target extended-remote". When using
1902 "target remote", you can disable the startup with shell by using the
1903 new "--no-startup-with-shell" GDBserver command line option.
1905 ** On Unix systems, GDBserver now supports receiving environment
1906 variables that are to be set or unset from GDB. These variables
1907 will affect the environment to be passed to the inferior.
1909 * When catching an Ada exception raised with a message, GDB now prints
1910 the message in the catchpoint hit notification. In GDB/MI mode, that
1911 information is provided as an extra field named "exception-message"
1912 in the *stopped notification.
1914 * Trait objects can now be inspected When debugging Rust code. This
1915 requires compiler support which will appear in Rust 1.24.
1917 * New remote packets
1919 QEnvironmentHexEncoded
1920 Inform GDBserver of an environment variable that is to be passed to
1921 the inferior when starting it.
1924 Inform GDBserver of an environment variable that is to be unset
1925 before starting the remote inferior.
1928 Inform GDBserver that the environment should be reset (i.e.,
1929 user-set environment variables should be unset).
1932 Indicates whether the inferior must be started with a shell or not.
1935 Tell GDBserver that the inferior to be started should use a specific
1938 * The "maintenance print c-tdesc" command now takes an optional
1939 argument which is the file name of XML target description.
1941 * The "maintenance selftest" command now takes an optional argument to
1942 filter the tests to be run.
1944 * The "enable", and "disable" commands now accept a range of
1945 breakpoint locations, e.g. "enable 1.3-5".
1950 Set and show the current working directory for the inferior.
1952 set|show compile-gcc
1953 Set and show compilation command used for compiling and injecting code
1954 with the 'compile' commands.
1956 set debug separate-debug-file
1957 show debug separate-debug-file
1958 Control the display of debug output about separate debug file search.
1960 set dump-excluded-mappings
1961 show dump-excluded-mappings
1962 Control whether mappings marked with the VM_DONTDUMP flag should be
1963 dumped when generating a core file.
1965 maint info selftests
1966 List the registered selftests.
1969 Start the debugged program stopping at the first instruction.
1972 Control display of debugging messages related to OpenRISC targets.
1974 set|show print type nested-type-limit
1975 Set and show the limit of nesting level for nested types that the
1976 type printer will show.
1978 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1981 * Safer/improved support for debugging with no debug info
1983 GDB no longer assumes functions with no debug information return
1986 This means that GDB now refuses to call such functions unless you
1987 tell it the function's type, by either casting the call to the
1988 declared return type, or by casting the function to a function
1989 pointer of the right type, and calling that:
1991 (gdb) p getenv ("PATH")
1992 'getenv' has unknown return type; cast the call to its declared return type
1993 (gdb) p (char *) getenv ("PATH")
1994 $1 = 0x7fffffffe "/usr/local/bin:/"...
1995 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1996 $2 = 0x7fffffffe "/usr/local/bin:/"...
1998 Similarly, GDB no longer assumes that global variables with no debug
1999 info have type 'int', and refuses to print the variable's value
2000 unless you tell it the variable's type:
2003 'var' has unknown type; cast it to its declared type
2007 * New native configurations
2009 FreeBSD/aarch64 aarch64*-*-freebsd*
2010 FreeBSD/arm arm*-*-freebsd*
2014 FreeBSD/aarch64 aarch64*-*-freebsd*
2015 FreeBSD/arm arm*-*-freebsd*
2016 OpenRISC ELF or1k*-*-elf
2018 * Removed targets and native configurations
2020 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2022 *** Changes in GDB 8.0
2024 * GDB now supports access to the PKU register on GNU/Linux. The register is
2025 added by the Memory Protection Keys for Userspace feature which will be
2026 available in future Intel CPUs.
2028 * GDB now supports C++11 rvalue references.
2032 ** New functions to start, stop and access a running btrace recording.
2033 ** Rvalue references are now supported in gdb.Type.
2035 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2038 * Building GDB and GDBserver now requires a C++11 compiler.
2040 For example, GCC 4.8 or later.
2042 It is no longer possible to build GDB or GDBserver with a C
2043 compiler. The --disable-build-with-cxx configure option has been
2046 * Building GDB and GDBserver now requires GNU make >= 3.81.
2048 It is no longer supported to build GDB or GDBserver with another
2049 implementation of the make program or an earlier version of GNU make.
2051 * Native debugging on MS-Windows supports command-line redirection
2053 Command-line arguments used for starting programs on MS-Windows can
2054 now include redirection symbols supported by native Windows shells,
2055 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2056 as "run", "start", and "set args", as well as the corresponding MI
2059 * Support for thread names on MS-Windows.
2061 GDB now catches and handles the special exception that programs
2062 running on MS-Windows use to assign names to threads in the
2065 * Support for Java programs compiled with gcj has been removed.
2067 * User commands now accept an unlimited number of arguments.
2068 Previously, only up to 10 was accepted.
2070 * The "eval" command now expands user-defined command arguments.
2072 This makes it easier to process a variable number of arguments:
2077 eval "print $arg%d", $i
2082 * Target descriptions can now describe registers for sparc32 and sparc64.
2084 * GDB now supports DWARF version 5 (debug information format).
2085 Its .debug_names index is not yet supported.
2087 * New native configurations
2089 FreeBSD/mips mips*-*-freebsd
2093 Synopsys ARC arc*-*-elf32
2094 FreeBSD/mips mips*-*-freebsd
2096 * Removed targets and native configurations
2098 Alpha running FreeBSD alpha*-*-freebsd*
2099 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2104 Erases all the flash memory regions reported by the target.
2106 maint print arc arc-instruction address
2107 Print internal disassembler information about instruction at a given address.
2111 set disassembler-options
2112 show disassembler-options
2113 Controls the passing of target specific information to the disassembler.
2114 If it is necessary to specify more than one disassembler option then
2115 multiple options can be placed together into a comma separated list.
2116 The default value is the empty string. Currently, the only supported
2117 targets are ARM, PowerPC and S/390.
2122 Erases all the flash memory regions reported by the target. This is
2123 equivalent to the CLI command flash-erase.
2125 -file-list-shared-libraries
2126 List the shared libraries in the program. This is
2127 equivalent to the CLI command "info shared".
2130 Catchpoints stopping the program when Ada exceptions are
2131 handled. This is equivalent to the CLI command "catch handlers".
2133 *** Changes in GDB 7.12
2135 * GDB and GDBserver now build with a C++ compiler by default.
2137 The --enable-build-with-cxx configure option is now enabled by
2138 default. One must now explicitly configure with
2139 --disable-build-with-cxx in order to build with a C compiler. This
2140 option will be removed in a future release.
2142 * GDBserver now supports recording btrace without maintaining an active
2145 * GDB now supports a negative repeat count in the 'x' command to examine
2146 memory backward from the given address. For example:
2149 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2150 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2151 (gdb) x/-5i 0x0000000000400580
2152 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2153 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2154 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2155 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2156 0x40057b <main(int, char**)+25>:
2157 callq 0x400536 <Func1(int, char const*)>
2159 * Fortran: Support structures with fields of dynamic types and
2160 arrays of dynamic types.
2162 * The symbol dumping maintenance commands have new syntax.
2163 maint print symbols [-pc address] [--] [filename]
2164 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2165 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2166 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2167 maint print msymbols [-objfile objfile] [--] [filename]
2169 * GDB now supports multibit bitfields and enums in target register
2172 * New Python-based convenience function $_as_string(val), which returns
2173 the textual representation of a value. This function is especially
2174 useful to obtain the text label of an enum value.
2176 * Intel MPX bound violation handling.
2178 Segmentation faults caused by a Intel MPX boundary violation
2179 now display the kind of violation (upper or lower), the memory
2180 address accessed and the memory bounds, along with the usual
2181 signal received and code location.
2185 Program received signal SIGSEGV, Segmentation fault
2186 Upper bound violation while accessing address 0x7fffffffc3b3
2187 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2188 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2190 * Rust language support.
2191 GDB now supports debugging programs written in the Rust programming
2192 language. See https://www.rust-lang.org/ for more information about
2195 * Support for running interpreters on specified input/output devices
2197 GDB now supports a new mechanism that allows frontends to provide
2198 fully featured GDB console views, as a better alternative to
2199 building such views on top of the "-interpreter-exec console"
2200 command. See the new "new-ui" command below. With that command,
2201 frontends can now start GDB in the traditional command-line mode
2202 running in an embedded terminal emulator widget, and create a
2203 separate MI interpreter running on a specified i/o device. In this
2204 way, GDB handles line editing, history, tab completion, etc. in the
2205 console all by itself, and the GUI uses the separate MI interpreter
2206 for its own control and synchronization, invisible to the command
2209 * The "catch syscall" command catches groups of related syscalls.
2211 The "catch syscall" command now supports catching a group of related
2212 syscalls using the 'group:' or 'g:' prefix.
2217 skip -gfile file-glob-pattern
2218 skip -function function
2219 skip -rfunction regular-expression
2220 A generalized form of the skip command, with new support for
2221 glob-style file names and regular expressions for function names.
2222 Additionally, a file spec and a function spec may now be combined.
2224 maint info line-table REGEXP
2225 Display the contents of GDB's internal line table data structure.
2228 Run any GDB unit tests that were compiled in.
2231 Start a new user interface instance running INTERP as interpreter,
2232 using the TTY file for input/output.
2236 ** gdb.Breakpoint objects have a new attribute "pending", which
2237 indicates whether the breakpoint is pending.
2238 ** Three new breakpoint-related events have been added:
2239 gdb.breakpoint_created, gdb.breakpoint_modified, and
2240 gdb.breakpoint_deleted.
2242 signal-event EVENTID
2243 Signal ("set") the given MS-Windows event object. This is used in
2244 conjunction with the Windows JIT debugging (AeDebug) support, where
2245 the OS suspends a crashing process until a debugger can attach to
2246 it. Resuming the crashing process, in order to debug it, is done by
2247 signalling an event.
2249 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2250 was added in GDBserver, including JIT compiling fast tracepoint's
2251 conditional expression bytecode into native code.
2253 * Support for various remote target protocols and ROM monitors has
2256 target m32rsdi Remote M32R debugging over SDI
2257 target mips MIPS remote debugging protocol
2258 target pmon PMON ROM monitor
2259 target ddb NEC's DDB variant of PMON for Vr4300
2260 target rockhopper NEC RockHopper variant of PMON
2261 target lsi LSI variant of PMO
2263 * Support for tracepoints and fast tracepoints on powerpc-linux,
2264 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2265 including JIT compiling fast tracepoint's conditional expression
2266 bytecode into native code.
2268 * MI async record =record-started now includes the method and format used for
2269 recording. For example:
2271 =record-started,thread-group="i1",method="btrace",format="bts"
2273 * MI async record =thread-selected now includes the frame field. For example:
2275 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2279 Andes NDS32 nds32*-*-elf
2281 *** Changes in GDB 7.11
2283 * GDB now supports debugging kernel-based threads on FreeBSD.
2285 * Per-inferior thread numbers
2287 Thread numbers are now per inferior instead of global. If you're
2288 debugging multiple inferiors, GDB displays thread IDs using a
2289 qualified INF_NUM.THR_NUM form. For example:
2293 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2294 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2295 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2296 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2298 As consequence, thread numbers as visible in the $_thread
2299 convenience variable and in Python's InferiorThread.num attribute
2300 are no longer unique between inferiors.
2302 GDB now maintains a second thread ID per thread, referred to as the
2303 global thread ID, which is the new equivalent of thread numbers in
2304 previous releases. See also $_gthread below.
2306 For backwards compatibility, MI's thread IDs always refer to global
2309 * Commands that accept thread IDs now accept the qualified
2310 INF_NUM.THR_NUM form as well. For example:
2313 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2316 * In commands that accept a list of thread IDs, you can now refer to
2317 all threads of an inferior using a star wildcard. GDB accepts
2318 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2319 refer to all threads of the current inferior. For example, "info
2322 * You can use "info threads -gid" to display the global thread ID of
2325 * The new convenience variable $_gthread holds the global number of
2328 * The new convenience variable $_inferior holds the number of the
2331 * GDB now displays the ID and name of the thread that hit a breakpoint
2332 or received a signal, if your program is multi-threaded. For
2335 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2336 Thread 1 "main" received signal SIGINT, Interrupt.
2338 * Record btrace now supports non-stop mode.
2340 * Support for tracepoints on aarch64-linux was added in GDBserver.
2342 * The 'record instruction-history' command now indicates speculative execution
2343 when using the Intel Processor Trace recording format.
2345 * GDB now allows users to specify explicit locations, bypassing
2346 the linespec parser. This feature is also available to GDB/MI
2349 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2350 GDB now is able to debug both AArch64 applications and ARM applications
2353 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2354 including JIT compiling fast tracepoint's conditional expression bytecode
2357 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2359 * "info threads", "info inferiors", "info display", "info checkpoints"
2360 and "maint info program-spaces" now list the corresponding items in
2361 ascending ID order, for consistency with all other "info" commands.
2363 * In Ada, the overloads selection menu has been enhanced to display the
2364 parameter types and the return types for the matching overloaded subprograms.
2368 maint set target-non-stop (on|off|auto)
2369 maint show target-non-stop
2370 Control whether GDB targets always operate in non-stop mode even if
2371 "set non-stop" is "off". The default is "auto", meaning non-stop
2372 mode is enabled if supported by the target.
2374 maint set bfd-sharing
2375 maint show bfd-sharing
2376 Control the reuse of bfd objects.
2379 show debug bfd-cache
2380 Control display of debugging info regarding bfd caching.
2384 Control display of debugging info regarding FreeBSD threads.
2386 set remote multiprocess-extensions-packet
2387 show remote multiprocess-extensions-packet
2388 Set/show the use of the remote protocol multiprocess extensions.
2390 set remote thread-events
2391 show remote thread-events
2392 Set/show the use of thread create/exit events.
2394 set ada print-signatures on|off
2395 show ada print-signatures"
2396 Control whether parameter types and return types are displayed in overloads
2397 selection menus. It is activated (@code{on}) by default.
2401 Controls the maximum size of memory, in bytes, that GDB will
2402 allocate for value contents. Prevents incorrect programs from
2403 causing GDB to allocate overly large buffers. Default is 64k.
2405 * The "disassemble" command accepts a new modifier: /s.
2406 It prints mixed source+disassembly like /m with two differences:
2407 - disassembled instructions are now printed in program order, and
2408 - and source for all relevant files is now printed.
2409 The "/m" option is now considered deprecated: its "source-centric"
2410 output hasn't proved useful in practice.
2412 * The "record instruction-history" command accepts a new modifier: /s.
2413 It behaves exactly like /m and prints mixed source+disassembly.
2415 * The "set scheduler-locking" command supports a new mode "replay".
2416 It behaves like "off" in record mode and like "on" in replay mode.
2418 * Support for various ROM monitors has been removed:
2420 target dbug dBUG ROM monitor for Motorola ColdFire
2421 target picobug Motorola picobug monitor
2422 target dink32 DINK32 ROM monitor for PowerPC
2423 target m32r Renesas M32R/D ROM monitor
2424 target mon2000 mon2000 ROM monitor
2425 target ppcbug PPCBUG ROM monitor for PowerPC
2427 * Support for reading/writing memory and extracting values on architectures
2428 whose memory is addressable in units of any integral multiple of 8 bits.
2431 Allows to break when an Ada exception is handled.
2433 * New remote packets
2436 Indicates that an exec system call was executed.
2438 exec-events feature in qSupported
2439 The qSupported packet allows GDB to request support for exec
2440 events using the new 'gdbfeature' exec-event, and the qSupported
2441 response can contain the corresponding 'stubfeature'. Set and
2442 show commands can be used to display whether these features are enabled.
2445 Equivalent to interrupting with the ^C character, but works in
2448 thread created stop reason (T05 create:...)
2449 Indicates that the thread was just created and is stopped at entry.
2451 thread exit stop reply (w exitcode;tid)
2452 Indicates that the thread has terminated.
2455 Enables/disables thread create and exit event reporting. For
2456 example, this is used in non-stop mode when GDB stops a set of
2457 threads and synchronously waits for the their corresponding stop
2458 replies. Without exit events, if one of the threads exits, GDB
2459 would hang forever not knowing that it should no longer expect a
2460 stop for that same thread.
2463 Indicates that there are no resumed threads left in the target (all
2464 threads are stopped). The remote stub reports support for this stop
2465 reply to GDB's qSupported query.
2468 Enables/disables catching syscalls from the inferior process.
2469 The remote stub reports support for this packet to GDB's qSupported query.
2471 syscall_entry stop reason
2472 Indicates that a syscall was just called.
2474 syscall_return stop reason
2475 Indicates that a syscall just returned.
2477 * Extended-remote exec events
2479 ** GDB now has support for exec events on extended-remote Linux targets.
2480 For such targets with Linux kernels 2.5.46 and later, this enables
2481 follow-exec-mode and exec catchpoints.
2483 set remote exec-event-feature-packet
2484 show remote exec-event-feature-packet
2485 Set/show the use of the remote exec event feature.
2487 * Thread names in remote protocol
2489 The reply to qXfer:threads:read may now include a name attribute for each
2492 * Target remote mode fork and exec events
2494 ** GDB now has support for fork and exec events on target remote mode
2495 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2496 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2497 fork and exec catchpoints.
2499 * Remote syscall events
2501 ** GDB now has support for catch syscall on remote Linux targets,
2502 currently enabled on x86/x86_64 architectures.
2504 set remote catch-syscall-packet
2505 show remote catch-syscall-packet
2506 Set/show the use of the remote catch syscall feature.
2510 ** The -var-set-format command now accepts the zero-hexadecimal
2511 format. It outputs data in hexadecimal format with zero-padding on the
2516 ** gdb.InferiorThread objects have a new attribute "global_num",
2517 which refers to the thread's global thread ID. The existing
2518 "num" attribute now refers to the thread's per-inferior number.
2519 See "Per-inferior thread numbers" above.
2520 ** gdb.InferiorThread objects have a new attribute "inferior", which
2521 is the Inferior object the thread belongs to.
2523 *** Changes in GDB 7.10
2525 * Support for process record-replay and reverse debugging on aarch64*-linux*
2526 targets has been added. GDB now supports recording of A64 instruction set
2527 including advance SIMD instructions.
2529 * Support for Sun's version of the "stabs" debug file format has been removed.
2531 * GDB now honors the content of the file /proc/PID/coredump_filter
2532 (PID is the process ID) on GNU/Linux systems. This file can be used
2533 to specify the types of memory mappings that will be included in a
2534 corefile. For more information, please refer to the manual page of
2535 "core(5)". GDB also has a new command: "set use-coredump-filter
2536 on|off". It allows to set whether GDB will read the content of the
2537 /proc/PID/coredump_filter file when generating a corefile.
2539 * The "info os" command on GNU/Linux can now display information on
2541 "info os cpus" Listing of all cpus/cores on the system
2543 * GDB has two new commands: "set serial parity odd|even|none" and
2544 "show serial parity". These allows to set or show parity for the
2547 * The "info source" command now displays the producer string if it was
2548 present in the debug info. This typically includes the compiler version
2549 and may include things like its command line arguments.
2551 * The "info dll", an alias of the "info sharedlibrary" command,
2552 is now available on all platforms.
2554 * Directory names supplied to the "set sysroot" commands may be
2555 prefixed with "target:" to tell GDB to access shared libraries from
2556 the target system, be it local or remote. This replaces the prefix
2557 "remote:". The default sysroot has been changed from "" to
2558 "target:". "remote:" is automatically converted to "target:" for
2559 backward compatibility.
2561 * The system root specified by "set sysroot" will be prepended to the
2562 filename of the main executable (if reported to GDB as absolute by
2563 the operating system) when starting processes remotely, and when
2564 attaching to already-running local or remote processes.
2566 * GDB now supports automatic location and retrieval of executable
2567 files from remote targets. Remote debugging can now be initiated
2568 using only a "target remote" or "target extended-remote" command
2569 (no "set sysroot" or "file" commands are required). See "New remote
2572 * The "dump" command now supports verilog hex format.
2574 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2576 * On GNU/Linux, GDB and gdbserver are now able to access executable
2577 and shared library files without a "set sysroot" command when
2578 attaching to processes running in different mount namespaces from
2579 the debugger. This makes it possible to attach to processes in
2580 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2581 See "New remote packets" below.
2583 * The "tui reg" command now provides completion for all of the
2584 available register groups, including target specific groups.
2586 * The HISTSIZE environment variable is no longer read when determining
2587 the size of GDB's command history. GDB now instead reads the dedicated
2588 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2589 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2594 ** Memory ports can now be unbuffered.
2598 ** gdb.Objfile objects have a new attribute "username",
2599 which is the name of the objfile as specified by the user,
2600 without, for example, resolving symlinks.
2601 ** You can now write frame unwinders in Python.
2602 ** gdb.Type objects have a new method "optimized_out",
2603 returning optimized out gdb.Value instance of this type.
2604 ** gdb.Value objects have new methods "reference_value" and
2605 "const_value" which return a reference to the value and a
2606 "const" version of the value respectively.
2610 maint print symbol-cache
2611 Print the contents of the symbol cache.
2613 maint print symbol-cache-statistics
2614 Print statistics of symbol cache usage.
2616 maint flush-symbol-cache
2617 Flush the contents of the symbol cache.
2621 Start branch trace recording using Branch Trace Store (BTS) format.
2624 Evaluate expression by using the compiler and print result.
2628 Explicit commands for enabling and disabling tui mode.
2631 set mpx bound on i386 and amd64
2632 Support for bound table investigation on Intel MPX enabled applications.
2636 Start branch trace recording using Intel Processor Trace format.
2639 Print information about branch tracing internals.
2641 maint btrace packet-history
2642 Print the raw branch tracing data.
2644 maint btrace clear-packet-history
2645 Discard the stored raw branch tracing data.
2648 Discard all branch tracing data. It will be fetched and processed
2649 anew by the next "record" command.
2654 Renamed from "set debug dwarf2-die".
2655 show debug dwarf-die
2656 Renamed from "show debug dwarf2-die".
2658 set debug dwarf-read
2659 Renamed from "set debug dwarf2-read".
2660 show debug dwarf-read
2661 Renamed from "show debug dwarf2-read".
2663 maint set dwarf always-disassemble
2664 Renamed from "maint set dwarf2 always-disassemble".
2665 maint show dwarf always-disassemble
2666 Renamed from "maint show dwarf2 always-disassemble".
2668 maint set dwarf max-cache-age
2669 Renamed from "maint set dwarf2 max-cache-age".
2670 maint show dwarf max-cache-age
2671 Renamed from "maint show dwarf2 max-cache-age".
2673 set debug dwarf-line
2674 show debug dwarf-line
2675 Control display of debugging info regarding DWARF line processing.
2678 show max-completions
2679 Set the maximum number of candidates to be considered during
2680 completion. The default value is 200. This limit allows GDB
2681 to avoid generating large completion lists, the computation of
2682 which can cause the debugger to become temporarily unresponsive.
2684 set history remove-duplicates
2685 show history remove-duplicates
2686 Control the removal of duplicate history entries.
2688 maint set symbol-cache-size
2689 maint show symbol-cache-size
2690 Control the size of the symbol cache.
2692 set|show record btrace bts buffer-size
2693 Set and show the size of the ring buffer used for branch tracing in
2695 The obtained size may differ from the requested size. Use "info
2696 record" to see the obtained buffer size.
2698 set debug linux-namespaces
2699 show debug linux-namespaces
2700 Control display of debugging info regarding Linux namespaces.
2702 set|show record btrace pt buffer-size
2703 Set and show the size of the ring buffer used for branch tracing in
2704 Intel Processor Trace format.
2705 The obtained size may differ from the requested size. Use "info
2706 record" to see the obtained buffer size.
2708 maint set|show btrace pt skip-pad
2709 Set and show whether PAD packets are skipped when computing the
2712 * The command 'thread apply all' can now support new option '-ascending'
2713 to call its specified command for all threads in ascending order.
2715 * Python/Guile scripting
2717 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2718 special section named `.debug_gdb_scripts'.
2720 * New remote packets
2722 qXfer:btrace-conf:read
2723 Return the branch trace configuration for the current thread.
2725 Qbtrace-conf:bts:size
2726 Set the requested ring buffer size for branch tracing in BTS format.
2729 Enable Intel Processor Trace-based branch tracing for the current
2730 process. The remote stub reports support for this packet to GDB's
2733 Qbtrace-conf:pt:size
2734 Set the requested ring buffer size for branch tracing in Intel Processor
2738 Indicates a memory breakpoint instruction was executed, irrespective
2739 of whether it was GDB that planted the breakpoint or the breakpoint
2740 is hardcoded in the program. This is required for correct non-stop
2744 Indicates the target stopped for a hardware breakpoint. This is
2745 required for correct non-stop mode operation.
2748 Return information about files on the remote system.
2750 qXfer:exec-file:read
2751 Return the full absolute name of the file that was executed to
2752 create a process running on the remote system.
2755 Select the filesystem on which vFile: operations with filename
2756 arguments will operate. This is required for GDB to be able to
2757 access files on remote targets where the remote stub does not
2758 share a common filesystem with the inferior(s).
2761 Indicates that a fork system call was executed.
2764 Indicates that a vfork system call was executed.
2766 vforkdone stop reason
2767 Indicates that a vfork child of the specified process has executed
2768 an exec or exit, allowing the vfork parent to resume execution.
2770 fork-events and vfork-events features in qSupported
2771 The qSupported packet allows GDB to request support for fork and
2772 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2773 and the qSupported response can contain the corresponding
2774 'stubfeatures'. Set and show commands can be used to display
2775 whether these features are enabled.
2777 * Extended-remote fork events
2779 ** GDB now has support for fork events on extended-remote Linux
2780 targets. For targets with Linux kernels 2.5.60 and later, this
2781 enables follow-fork-mode and detach-on-fork for both fork and
2782 vfork, as well as fork and vfork catchpoints.
2784 * The info record command now shows the recording format and the
2785 branch tracing configuration for the current thread when using
2786 the btrace record target.
2787 For the BTS format, it shows the ring buffer size.
2789 * GDB now has support for DTrace USDT (Userland Static Defined
2790 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2792 * GDB now supports access to vector registers on S/390 GNU/Linux
2795 * Removed command line options
2797 -xdb HP-UX XDB compatibility mode.
2799 * Removed targets and native configurations
2801 HP/PA running HP-UX hppa*-*-hpux*
2802 Itanium running HP-UX ia64-*-hpux*
2804 * New configure options
2807 This configure option allows the user to build GDB with support for
2808 Intel Processor Trace (default: auto). This requires libipt.
2810 --with-libipt-prefix=PATH
2811 Specify the path to the version of libipt that GDB should use.
2812 $PATH/include should contain the intel-pt.h header and
2813 $PATH/lib should contain the libipt.so library.
2815 *** Changes in GDB 7.9.1
2819 ** Xmethods can now specify a result type.
2821 *** Changes in GDB 7.9
2823 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2827 ** You can now access frame registers from Python scripts.
2828 ** New attribute 'producer' for gdb.Symtab objects.
2829 ** gdb.Objfile objects have a new attribute "progspace",
2830 which is the gdb.Progspace object of the containing program space.
2831 ** gdb.Objfile objects have a new attribute "owner".
2832 ** gdb.Objfile objects have a new attribute "build_id",
2833 which is the build ID generated when the file was built.
2834 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2835 ** A new event "gdb.clear_objfiles" has been added, triggered when
2836 selecting a new file to debug.
2837 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2838 ** New function gdb.lookup_objfile.
2840 New events which are triggered when GDB modifies the state of the
2843 ** gdb.events.inferior_call_pre: Function call is about to be made.
2844 ** gdb.events.inferior_call_post: Function call has just been made.
2845 ** gdb.events.memory_changed: A memory location has been altered.
2846 ** gdb.events.register_changed: A register has been altered.
2848 * New Python-based convenience functions:
2850 ** $_caller_is(name [, number_of_frames])
2851 ** $_caller_matches(regexp [, number_of_frames])
2852 ** $_any_caller_is(name [, number_of_frames])
2853 ** $_any_caller_matches(regexp [, number_of_frames])
2855 * GDB now supports the compilation and injection of source code into
2856 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2857 to compile the source code to object code, and if successful, inject
2858 and execute that code within the current context of the inferior.
2859 Currently the C language is supported. The commands used to
2860 interface with this new feature are:
2862 compile code [-raw|-r] [--] [source code]
2863 compile file [-raw|-r] filename
2867 demangle [-l language] [--] name
2868 Demangle "name" in the specified language, or the current language
2869 if elided. This command is renamed from the "maint demangle" command.
2870 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2871 as "maint demangler-warning".
2873 queue-signal signal-name-or-number
2874 Queue a signal to be delivered to the thread when it is resumed.
2876 add-auto-load-scripts-directory directory
2877 Add entries to the list of directories from which to load auto-loaded
2880 maint print user-registers
2881 List all currently available "user" registers.
2883 compile code [-r|-raw] [--] [source code]
2884 Compile, inject, and execute in the inferior the executable object
2885 code produced by compiling the provided source code.
2887 compile file [-r|-raw] filename
2888 Compile and inject into the inferior the executable object code
2889 produced by compiling the source code stored in the filename
2892 * On resume, GDB now always passes the signal the program had stopped
2893 for to the thread the signal was sent to, even if the user changed
2894 threads before resuming. Previously GDB would often (but not
2895 always) deliver the signal to the thread that happens to be current
2898 * Conversely, the "signal" command now consistently delivers the
2899 requested signal to the current thread. GDB now asks for
2900 confirmation if the program had stopped for a signal and the user
2901 switched threads meanwhile.
2903 * "breakpoint always-inserted" modes "off" and "auto" merged.
2905 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2906 won't remove breakpoints from the target until all threads stop,
2907 even in non-stop mode. The "auto" mode has been removed, and "off"
2908 is now the default mode.
2912 set debug symbol-lookup
2913 show debug symbol-lookup
2914 Control display of debugging info regarding symbol lookup.
2918 ** The -list-thread-groups command outputs an exit-code field for
2919 inferiors that have exited.
2923 MIPS SDE mips*-sde*-elf*
2927 Support for these obsolete configurations has been removed.
2929 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2930 SGI Irix-5.x mips-*-irix5*
2931 SGI Irix-6.x mips-*-irix6*
2932 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2933 VAX running Ultrix vax-*-ultrix*
2935 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2936 and "assf"), have been removed. Use the "sharedlibrary" command, or
2937 its alias "share", instead.
2939 *** Changes in GDB 7.8
2941 * New command line options
2944 This is an alias for the --data-directory option.
2946 * GDB supports printing and modifying of variable length automatic arrays
2947 as specified in ISO C99.
2949 * The ARM simulator now supports instruction level tracing
2950 with or without disassembly.
2954 GDB now has support for scripting using Guile. Whether this is
2955 available is determined at configure time.
2956 Guile version 2.0 or greater is required.
2957 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2959 * New commands (for set/show, see "New options" below)
2963 Invoke CODE by passing it to the Guile interpreter.
2967 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2969 info auto-load guile-scripts [regexp]
2970 Print the list of automatically loaded Guile scripts.
2972 * The source command is now capable of sourcing Guile scripts.
2973 This feature is dependent on the debugger being built with Guile support.
2977 set print symbol-loading (off|brief|full)
2978 show print symbol-loading
2979 Control whether to print informational messages when loading symbol
2980 information for a file. The default is "full", but when debugging
2981 programs with large numbers of shared libraries the amount of output
2982 becomes less useful.
2984 set guile print-stack (none|message|full)
2985 show guile print-stack
2986 Show a stack trace when an error is encountered in a Guile script.
2988 set auto-load guile-scripts (on|off)
2989 show auto-load guile-scripts
2990 Control auto-loading of Guile script files.
2992 maint ada set ignore-descriptive-types (on|off)
2993 maint ada show ignore-descriptive-types
2994 Control whether the debugger should ignore descriptive types in Ada
2995 programs. The default is not to ignore the descriptive types. See
2996 the user manual for more details on descriptive types and the intended
2997 usage of this option.
2999 set auto-connect-native-target
3001 Control whether GDB is allowed to automatically connect to the
3002 native target for the run, attach, etc. commands when not connected
3003 to any target yet. See also "target native" below.
3005 set record btrace replay-memory-access (read-only|read-write)
3006 show record btrace replay-memory-access
3007 Control what memory accesses are allowed during replay.
3009 maint set target-async (on|off)
3010 maint show target-async
3011 This controls whether GDB targets operate in synchronous or
3012 asynchronous mode. Normally the default is asynchronous, if it is
3013 available; but this can be changed to more easily debug problems
3014 occurring only in synchronous mode.
3016 set mi-async (on|off)
3018 Control whether MI asynchronous mode is preferred. This supersedes
3019 "set target-async" of previous GDB versions.
3021 * "set target-async" is deprecated as a CLI option and is now an alias
3022 for "set mi-async" (only puts MI into async mode).
3024 * Background execution commands (e.g., "c&", "s&", etc.) are now
3025 possible ``out of the box'' if the target supports them. Previously
3026 the user would need to explicitly enable the possibility with the
3027 "set target-async on" command.
3029 * New features in the GDB remote stub, GDBserver
3031 ** New option --debug-format=option1[,option2,...] allows one to add
3032 additional text to each output. At present only timestamps
3033 are supported: --debug-format=timestamps.
3034 Timestamps can also be turned on with the
3035 "monitor set debug-format timestamps" command from GDB.
3037 * The 'record instruction-history' command now starts counting instructions
3038 at one. This also affects the instruction ranges reported by the
3039 'record function-call-history' command when given the /i modifier.
3041 * The command 'record function-call-history' supports a new modifier '/c' to
3042 indent the function names based on their call stack depth.
3043 The fields for the '/i' and '/l' modifier have been reordered.
3044 The source line range is now prefixed with 'at'.
3045 The instruction range is now prefixed with 'inst'.
3046 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3047 "record instruction-history" and "list" commands.
3049 * The ranges given as arguments to the 'record function-call-history' and
3050 'record instruction-history' commands are now inclusive.
3052 * The btrace record target now supports the 'record goto' command.
3053 For locations inside the execution trace, the back trace is computed
3054 based on the information stored in the execution trace.
3056 * The btrace record target supports limited reverse execution and replay.
3057 The target does not record data and therefore does not allow reading
3058 memory or registers.
3060 * The "catch syscall" command now works on s390*-linux* targets.
3062 * The "compare-sections" command is no longer specific to target
3063 remote. It now works with all targets.
3065 * All native targets are now consistently called "native".
3066 Consequently, the "target child", "target GNU", "target djgpp",
3067 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3068 commands have been replaced with "target native". The QNX/NTO port
3069 leaves the "procfs" target in place and adds a "native" target for
3070 consistency with other ports. The impact on users should be minimal
3071 as these commands previously either throwed an error, or were
3072 no-ops. The target's name is visible in the output of the following
3073 commands: "help target", "info target", "info files", "maint print
3076 * The "target native" command now connects to the native target. This
3077 can be used to launch native programs even when "set
3078 auto-connect-native-target" is set to off.
3080 * GDB now supports access to Intel MPX registers on GNU/Linux.
3082 * Support for Intel AVX-512 registers on GNU/Linux.
3083 Support displaying and modifying Intel AVX-512 registers
3084 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3086 * New remote packets
3088 qXfer:btrace:read's annex
3089 The qXfer:btrace:read packet supports a new annex 'delta' to read
3090 branch trace incrementally.
3094 ** Valid Python operations on gdb.Value objects representing
3095 structs/classes invoke the corresponding overloaded operators if
3097 ** New `Xmethods' feature in the Python API. Xmethods are
3098 additional methods or replacements for existing methods of a C++
3099 class. This feature is useful for those cases where a method
3100 defined in C++ source code could be inlined or optimized out by
3101 the compiler, making it unavailable to GDB.
3104 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3106 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3107 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3108 its alias "share", instead.
3110 * The commands "set remotebaud" and "show remotebaud" are no longer
3111 supported. Use "set serial baud" and "show serial baud" (respectively)
3116 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3117 target-async". The latter is left as a deprecated alias of the
3118 former for backward compatibility. If the target supports it,
3119 CLI background execution commands are now always possible by
3120 default, independently of whether the frontend stated a
3121 preference for asynchronous execution with "-gdb-set mi-async".
3122 Previously "-gdb-set target-async off" affected both MI execution
3123 commands and CLI execution commands.
3125 *** Changes in GDB 7.7
3127 * Improved support for process record-replay and reverse debugging on
3128 arm*-linux* targets. Support for thumb32 and syscall instruction
3129 recording has been added.
3131 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3133 * GDB now supports Fission DWP file format version 2.
3134 http://gcc.gnu.org/wiki/DebugFission
3136 * New convenience function "$_isvoid", to check whether an expression
3137 is void. A void expression is an expression where the type of the
3138 result is "void". For example, some convenience variables may be
3139 "void" when evaluated (e.g., "$_exitcode" before the execution of
3140 the program being debugged; or an undefined convenience variable).
3141 Another example, when calling a function whose return type is
3144 * The "maintenance print objfiles" command now takes an optional regexp.
3146 * The "catch syscall" command now works on arm*-linux* targets.
3148 * GDB now consistently shows "<not saved>" when printing values of
3149 registers the debug info indicates have not been saved in the frame
3150 and there's nowhere to retrieve them from
3151 (callee-saved/call-clobbered registers):
3156 (gdb) info registers rax
3159 Before, the former would print "<optimized out>", and the latter
3160 "*value not available*".
3162 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3167 ** Frame filters and frame decorators have been added.
3168 ** Temporary breakpoints are now supported.
3169 ** Line tables representation has been added.
3170 ** New attribute 'parent_type' for gdb.Field objects.
3171 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3172 ** New attribute 'name' for gdb.Type objects.
3176 Nios II ELF nios2*-*-elf
3177 Nios II GNU/Linux nios2*-*-linux
3178 Texas Instruments MSP430 msp430*-*-elf
3180 * Removed native configurations
3182 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3183 been removed. ELF variants of these configurations are kept supported.
3185 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3186 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3187 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3188 i[34567]86-*-openbsd3.[0-3]
3189 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3190 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3191 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3195 Like "catch throw", but catches a re-thrown exception.
3196 maint check-psymtabs
3197 Renamed from old "maint check-symtabs".
3199 Perform consistency checks on symtabs.
3200 maint expand-symtabs
3201 Expand symtabs matching an optional regexp.
3204 Display the details of GDB configure-time options.
3206 maint set|show per-command
3207 maint set|show per-command space
3208 maint set|show per-command time
3209 maint set|show per-command symtab
3210 Enable display of per-command gdb resource usage.
3212 remove-symbol-file FILENAME
3213 remove-symbol-file -a ADDRESS
3214 Remove a symbol file added via add-symbol-file. The file to remove
3215 can be identified by its filename or by an address that lies within
3216 the boundaries of this symbol file in memory.
3219 info exceptions REGEXP
3220 Display the list of Ada exceptions defined in the program being
3221 debugged. If provided, only the exceptions whose names match REGEXP
3226 set debug symfile off|on
3228 Control display of debugging info regarding reading symbol files and
3229 symbol tables within those files
3231 set print raw frame-arguments
3232 show print raw frame-arguments
3233 Set/show whether to print frame arguments in raw mode,
3234 disregarding any defined pretty-printers.
3236 set remote trace-status-packet
3237 show remote trace-status-packet
3238 Set/show the use of remote protocol qTStatus packet.
3242 Control display of debugging messages related to Nios II targets.
3246 Control whether target-assisted range stepping is enabled.
3248 set startup-with-shell
3249 show startup-with-shell
3250 Specifies whether Unix child processes are started via a shell or
3255 Use the target memory cache for accesses to the code segment. This
3256 improves performance of remote debugging (particularly disassembly).
3258 * You can now use a literal value 'unlimited' for options that
3259 interpret 0 or -1 as meaning "unlimited". E.g., "set
3260 trace-buffer-size unlimited" is now an alias for "set
3261 trace-buffer-size -1" and "set height unlimited" is now an alias for
3264 * The "set debug symtab-create" debugging option of GDB has been changed to
3265 accept a verbosity level. 0 means "off", 1 provides basic debugging
3266 output, and values of 2 or greater provides more verbose output.
3268 * New command-line options
3270 Display the details of GDB configure-time options.
3272 * The command 'tsave' can now support new option '-ctf' to save trace
3273 buffer in Common Trace Format.
3275 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3278 * GDB now implements the C++ 'typeid' operator.
3280 * The new convenience variable $_exception holds the exception being
3281 thrown or caught at an exception-related catchpoint.
3283 * The exception-related catchpoints, like "catch throw", now accept a
3284 regular expression which can be used to filter exceptions by type.
3286 * The new convenience variable $_exitsignal is automatically set to
3287 the terminating signal number when the program being debugged dies
3288 due to an uncaught signal.
3292 ** All MI commands now accept an optional "--language" option.
3293 Support for this feature can be verified by using the "-list-features"
3294 command, which should contain "language-option".
3296 ** The new command -info-gdb-mi-command allows the user to determine
3297 whether a GDB/MI command is supported or not.
3299 ** The "^error" result record returned when trying to execute an undefined
3300 GDB/MI command now provides a variable named "code" whose content is the
3301 "undefined-command" error code. Support for this feature can be verified
3302 by using the "-list-features" command, which should contain
3303 "undefined-command-error-code".
3305 ** The -trace-save MI command can optionally save trace buffer in Common
3308 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3310 ** The command -data-list-register-values now accepts an optional
3311 "--skip-unavailable" option. When used, only the available registers
3314 ** The new command -trace-frame-collected dumps collected variables,
3315 computed expressions, tvars, memory and registers in a traceframe.
3317 ** The commands -stack-list-locals, -stack-list-arguments and
3318 -stack-list-variables now accept an option "--skip-unavailable".
3319 When used, only the available locals or arguments are displayed.
3321 ** The -exec-run command now accepts an optional "--start" option.
3322 When used, the command follows the same semantics as the "start"
3323 command, stopping the program's execution at the start of its
3324 main subprogram. Support for this feature can be verified using
3325 the "-list-features" command, which should contain
3326 "exec-run-start-option".
3328 ** The new commands -catch-assert and -catch-exceptions insert
3329 catchpoints stopping the program when Ada exceptions are raised.
3331 ** The new command -info-ada-exceptions provides the equivalent of
3332 the new "info exceptions" command.
3334 * New system-wide configuration scripts
3335 A GDB installation now provides scripts suitable for use as system-wide
3336 configuration scripts for the following systems:
3340 * GDB now supports target-assigned range stepping with remote targets.
3341 This improves the performance of stepping source lines by reducing
3342 the number of control packets from/to GDB. See "New remote packets"
3345 * GDB now understands the element 'tvar' in the XML traceframe info.
3346 It has the id of the collected trace state variables.
3348 * On S/390 targets that provide the transactional-execution feature,
3349 the program interruption transaction diagnostic block (TDB) is now
3350 represented as a number of additional "registers" in GDB.
3352 * New remote packets
3356 The vCont packet supports a new 'r' action, that tells the remote
3357 stub to step through an address range itself, without GDB
3358 involvemement at each single-step.
3360 qXfer:libraries-svr4:read's annex
3361 The previously unused annex of the qXfer:libraries-svr4:read packet
3362 is now used to support passing an argument list. The remote stub
3363 reports support for this argument list to GDB's qSupported query.
3364 The defined arguments are "start" and "prev", used to reduce work
3365 necessary for library list updating, resulting in significant
3368 * New features in the GDB remote stub, GDBserver
3370 ** GDBserver now supports target-assisted range stepping. Currently
3371 enabled on x86/x86_64 GNU/Linux targets.
3373 ** GDBserver now adds element 'tvar' in the XML in the reply to
3374 'qXfer:traceframe-info:read'. It has the id of the collected
3375 trace state variables.
3377 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3380 * New 'z' formatter for printing and examining memory, this displays the
3381 value as hexadecimal zero padded on the left to the size of the type.
3383 * GDB can now use Windows x64 unwinding data.
3385 * The "set remotebaud" command has been replaced by "set serial baud".
3386 Similarly, "show remotebaud" has been replaced by "show serial baud".
3387 The "set remotebaud" and "show remotebaud" commands are still available
3388 to provide backward compatibility with older versions of GDB.
3390 *** Changes in GDB 7.6
3392 * Target record has been renamed to record-full.
3393 Record/replay is now enabled with the "record full" command.
3394 This also affects settings that are associated with full record/replay
3395 that have been moved from "set/show record" to "set/show record full":
3397 set|show record full insn-number-max
3398 set|show record full stop-at-limit
3399 set|show record full memory-query
3401 * A new record target "record-btrace" has been added. The new target
3402 uses hardware support to record the control-flow of a process. It
3403 does not support replaying the execution, but it implements the
3404 below new commands for investigating the recorded execution log.
3405 This new recording method can be enabled using:
3409 The "record-btrace" target is only available on Intel Atom processors
3410 and requires a Linux kernel 2.6.32 or later.
3412 * Two new commands have been added for record/replay to give information
3413 about the recorded execution without having to replay the execution.
3414 The commands are only supported by "record btrace".
3416 record instruction-history prints the execution history at
3417 instruction granularity
3419 record function-call-history prints the execution history at
3420 function granularity
3422 * New native configurations
3424 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3425 FreeBSD/powerpc powerpc*-*-freebsd
3426 x86_64/Cygwin x86_64-*-cygwin*
3427 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3431 ARM AArch64 aarch64*-*-elf
3432 ARM AArch64 GNU/Linux aarch64*-*-linux
3433 Lynx 178 PowerPC powerpc-*-lynx*178
3434 x86_64/Cygwin x86_64-*-cygwin*
3435 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3437 * If the configured location of system.gdbinit file (as given by the
3438 --with-system-gdbinit option at configure time) is in the
3439 data-directory (as specified by --with-gdb-datadir at configure
3440 time) or in one of its subdirectories, then GDB will look for the
3441 system-wide init file in the directory specified by the
3442 --data-directory command-line option.
3444 * New command line options:
3446 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3447 other initialization files, unlike -nx which disables all of them.
3449 * Removed command line options
3451 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3454 * The 'ptype' and 'whatis' commands now accept an argument to control
3457 * 'info proc' now works on some core files.
3461 ** Vectors can be created with gdb.Type.vector.
3463 ** Python's atexit.register now works in GDB.
3465 ** Types can be pretty-printed via a Python API.
3467 ** Python 3 is now supported (in addition to Python 2.4 or later)
3469 ** New class gdb.Architecture exposes GDB's internal representation
3470 of architecture in the Python API.
3472 ** New method Frame.architecture returns the gdb.Architecture object
3473 corresponding to the frame's architecture.
3475 * New Python-based convenience functions:
3477 ** $_memeq(buf1, buf2, length)
3478 ** $_streq(str1, str2)
3480 ** $_regex(str, regex)
3482 * The 'cd' command now defaults to using '~' (the home directory) if not
3485 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3486 default for GCC since November 2000.
3488 * The command 'forward-search' can now be abbreviated as 'fo'.
3490 * The command 'info tracepoints' can now display 'installed on target'
3491 or 'not installed on target' for each non-pending location of tracepoint.
3493 * New configure options
3495 --enable-libmcheck/--disable-libmcheck
3496 By default, development versions are built with -lmcheck on hosts
3497 that support it, in order to help track memory corruption issues.
3498 Release versions, on the other hand, are built without -lmcheck
3499 by default. The --enable-libmcheck/--disable-libmcheck configure
3500 options allow the user to override that default.
3501 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3502 This configure option allows the user to build GDB with
3503 libbabeltrace using which GDB can read Common Trace Format data.
3505 * New commands (for set/show, see "New options" below)
3508 Catch signals. This is similar to "handle", but allows commands and
3509 conditions to be attached.
3512 List the BFDs known to GDB.
3514 python-interactive [command]
3516 Start a Python interactive prompt, or evaluate the optional command
3517 and print the result of expressions.
3520 "py" is a new alias for "python".
3522 enable type-printer [name]...
3523 disable type-printer [name]...
3524 Enable or disable type printers.
3528 ** For the Renesas Super-H architecture, the "regs" command has been removed
3529 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3534 set print type methods (on|off)
3535 show print type methods
3536 Control whether method declarations are displayed by "ptype".
3537 The default is to show them.
3539 set print type typedefs (on|off)
3540 show print type typedefs
3541 Control whether typedef definitions are displayed by "ptype".
3542 The default is to show them.
3544 set filename-display basename|relative|absolute
3545 show filename-display
3546 Control the way in which filenames is displayed.
3547 The default is "relative", which preserves previous behavior.
3549 set trace-buffer-size
3550 show trace-buffer-size
3551 Request target to change the size of trace buffer.
3553 set remote trace-buffer-size-packet auto|on|off
3554 show remote trace-buffer-size-packet
3555 Control the use of the remote protocol `QTBuffer:size' packet.
3559 Control display of debugging messages related to ARM AArch64.
3562 set debug coff-pe-read
3563 show debug coff-pe-read
3564 Control display of debugging messages related to reading of COFF/PE
3569 Control display of debugging messages related to Mach-O symbols
3572 set debug notification
3573 show debug notification
3574 Control display of debugging info for async remote notification.
3578 ** Command parameter changes are now notified using new async record
3579 "=cmd-param-changed".
3580 ** Trace frame changes caused by command "tfind" are now notified using
3581 new async record "=traceframe-changed".
3582 ** The creation, deletion and modification of trace state variables
3583 are now notified using new async records "=tsv-created",
3584 "=tsv-deleted" and "=tsv-modified".
3585 ** The start and stop of process record are now notified using new
3586 async record "=record-started" and "=record-stopped".
3587 ** Memory changes are now notified using new async record
3589 ** The data-disassemble command response will include a "fullname" field
3590 containing the absolute file name when source has been requested.
3591 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3592 command, to allow pattern filling of memory areas.
3593 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3594 library load/unload events.
3595 ** The response to breakpoint commands and breakpoint async records
3596 includes an "installed" field containing a boolean state about each
3597 non-pending tracepoint location is whether installed on target or not.
3598 ** Output of the "-trace-status" command includes a "trace-file" field
3599 containing the name of the trace file being examined. This field is
3600 optional, and only present when examining a trace file.
3601 ** The "fullname" field is now always present along with the "file" field,
3602 even if the file cannot be found by GDB.
3604 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3605 You must have the LZMA library available when configuring GDB for this
3606 feature to be enabled. For more information, see:
3607 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3609 * New remote packets
3612 Set the size of trace buffer. The remote stub reports support for this
3613 packet to gdb's qSupported query.
3616 Enable Branch Trace Store (BTS)-based branch tracing for the current
3617 thread. The remote stub reports support for this packet to gdb's
3621 Disable branch tracing for the current thread. The remote stub reports
3622 support for this packet to gdb's qSupported query.
3625 Read the traced branches for the current thread. The remote stub
3626 reports support for this packet to gdb's qSupported query.
3628 *** Changes in GDB 7.5
3630 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3631 for more x32 ABI info.
3633 * GDB now supports access to MIPS DSP registers on Linux targets.
3635 * GDB now supports debugging microMIPS binaries.
3637 * The "info os" command on GNU/Linux can now display information on
3638 several new classes of objects managed by the operating system:
3639 "info os procgroups" lists process groups
3640 "info os files" lists file descriptors
3641 "info os sockets" lists internet-domain sockets
3642 "info os shm" lists shared-memory regions
3643 "info os semaphores" lists semaphores
3644 "info os msg" lists message queues
3645 "info os modules" lists loaded kernel modules
3647 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3648 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3649 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3650 options and inspect the probe arguments using the new $_probe_arg family
3651 of convenience variables. You can obtain more information about SystemTap
3652 in <http://sourceware.org/systemtap/>.
3654 * GDB now supports reversible debugging on ARM, it allows you to
3655 debug basic ARM and THUMB instructions, and provides
3656 record/replay support.
3658 * The option "symbol-reloading" has been deleted as it is no longer used.
3662 ** GDB commands implemented in Python can now be put in command class
3665 ** The "maint set python print-stack on|off" is now deleted.
3667 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3668 apply "flag enum"-style pretty-printing to any enum.
3670 ** gdb.lookup_symbol can now work when there is no current frame.
3672 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3673 the source at which the symbol was defined.
3675 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3676 method 'value'. The former indicates whether the symbol needs a
3677 frame in order to compute its value, and the latter computes the
3680 ** A new method 'referenced_value' on gdb.Value objects which can
3681 dereference pointer as well as C++ reference values.
3683 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3684 which return the global and static blocks (as gdb.Block objects),
3685 of the underlying symbol table, respectively.
3687 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3688 object associated with a PC value.
3690 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3691 of the address range occupied by code for the current source line.
3693 * Go language support.
3694 GDB now supports debugging programs written in the Go programming
3697 * GDBserver now supports stdio connections.
3698 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3700 * The binary "gdbtui" can no longer be built or installed.
3701 Use "gdb -tui" instead.
3703 * GDB will now print "flag" enums specially. A flag enum is one where
3704 all the enumerator values have no bits in common when pairwise
3705 "and"ed. When printing a value whose type is a flag enum, GDB will
3706 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3707 (gdb) print (enum E) 3
3710 * The filename part of a linespec will now match trailing components
3711 of a source file name. For example, "break gcc/expr.c:1000" will
3712 now set a breakpoint in build/gcc/expr.c, but not
3713 build/libcpp/expr.c.
3715 * The "info proc" and "generate-core-file" commands will now also
3716 work on remote targets connected to GDBserver on Linux.
3718 * The command "info catch" has been removed. It has been disabled
3719 since December 2007.
3721 * The "catch exception" and "catch assert" commands now accept
3722 a condition at the end of the command, much like the "break"
3723 command does. For instance:
3725 (gdb) catch exception Constraint_Error if Barrier = True
3727 Previously, it was possible to add a condition to such catchpoints,
3728 but it had to be done as a second step, after the catchpoint had been
3729 created, using the "condition" command.
3731 * The "info static-tracepoint-marker" command will now also work on
3732 native Linux targets with in-process agent.
3734 * GDB can now set breakpoints on inlined functions.
3736 * The .gdb_index section has been updated to include symbols for
3737 inlined functions. GDB will ignore older .gdb_index sections by
3738 default, which could cause symbol files to be loaded more slowly
3739 until their .gdb_index sections can be recreated. The new command
3740 "set use-deprecated-index-sections on" will cause GDB to use any older
3741 .gdb_index sections it finds. This will restore performance, but the
3742 ability to set breakpoints on inlined functions will be lost in symbol
3743 files with older .gdb_index sections.
3745 The .gdb_index section has also been updated to record more information
3746 about each symbol. This speeds up the "info variables", "info functions"
3747 and "info types" commands when used with programs having the .gdb_index
3748 section, as well as speeding up debugging with shared libraries using
3749 the .gdb_index section.
3751 * Ada support for GDB/MI Variable Objects has been added.
3753 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3758 ** New command -info-os is the MI equivalent of "info os".
3760 ** Output logs ("set logging" and related) now include MI output.
3764 ** "set use-deprecated-index-sections on|off"
3765 "show use-deprecated-index-sections on|off"
3766 Controls the use of deprecated .gdb_index sections.
3768 ** "catch load" and "catch unload" can be used to stop when a shared
3769 library is loaded or unloaded, respectively.
3771 ** "enable count" can be used to auto-disable a breakpoint after
3774 ** "info vtbl" can be used to show the virtual method tables for
3775 C++ and Java objects.
3777 ** "explore" and its sub commands "explore value" and "explore type"
3778 can be used to recursively explore values and types of
3779 expressions. These commands are available only if GDB is
3780 configured with '--with-python'.
3782 ** "info auto-load" shows status of all kinds of auto-loaded files,
3783 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3784 sequences of commands files, "info auto-load python-scripts"
3785 shows status of auto-loading Python script files,
3786 "info auto-load local-gdbinit" shows status of loading init file
3787 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3788 status of inferior specific thread debugging shared library loading.
3790 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3791 and "show auto-load-scripts" commands have been deprecated, use their
3792 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3793 and "show auto-load python-scripts" counterparts instead.
3795 ** "dprintf location,format,args..." creates a dynamic printf, which
3796 is basically a breakpoint that does a printf and immediately
3797 resumes your program's execution, so it is like a printf that you
3798 can insert dynamically at runtime instead of at compiletime.
3800 ** "set print symbol"
3802 Controls whether GDB attempts to display the symbol, if any,
3803 corresponding to addresses it prints. This defaults to "on", but
3804 you can set it to "off" to restore GDB's previous behavior.
3806 * Deprecated commands
3808 ** For the Renesas Super-H architecture, the "regs" command has been
3809 deprecated, and "info all-registers" should be used instead.
3813 Renesas RL78 rl78-*-elf
3814 HP OpenVMS ia64 ia64-hp-openvms*
3816 * GDBserver supports evaluation of breakpoint conditions. When
3817 support is advertised by GDBserver, GDB may be told to send the
3818 breakpoint conditions in bytecode form to GDBserver. GDBserver
3819 will only report the breakpoint trigger to GDB when its condition
3824 set mips compression
3825 show mips compression
3826 Select the compressed ISA encoding used in functions that have no symbol
3827 information available. The encoding can be set to either of:
3830 and is updated automatically from ELF file flags if available.
3832 set breakpoint condition-evaluation
3833 show breakpoint condition-evaluation
3834 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3835 GDBserver ("target"). Default option "auto" chooses the most efficient
3837 This option can improve debugger efficiency depending on the speed of the
3841 Disable auto-loading globally.
3844 Show auto-loading setting of all kinds of auto-loaded files.
3846 set auto-load gdb-scripts on|off
3847 show auto-load gdb-scripts
3848 Control auto-loading of GDB canned sequences of commands files.
3850 set auto-load python-scripts on|off
3851 show auto-load python-scripts
3852 Control auto-loading of Python script files.
3854 set auto-load local-gdbinit on|off
3855 show auto-load local-gdbinit
3856 Control loading of init file (.gdbinit) from current directory.
3858 set auto-load libthread-db on|off
3859 show auto-load libthread-db
3860 Control auto-loading of inferior specific thread debugging shared library.
3862 set auto-load scripts-directory <dir1>[:<dir2>...]
3863 show auto-load scripts-directory
3864 Set a list of directories from which to load auto-loaded scripts.
3865 Automatically loaded Python scripts and GDB scripts are located in one
3866 of the directories listed by this option.
3867 The delimiter (':' above) may differ according to the host platform.
3869 set auto-load safe-path <dir1>[:<dir2>...]
3870 show auto-load safe-path
3871 Set a list of directories from which it is safe to auto-load files.
3872 The delimiter (':' above) may differ according to the host platform.
3874 set debug auto-load on|off
3875 show debug auto-load
3876 Control display of debugging info for auto-loading the files above.
3878 set dprintf-style gdb|call|agent
3880 Control the way in which a dynamic printf is performed; "gdb"
3881 requests a GDB printf command, while "call" causes dprintf to call a
3882 function in the inferior. "agent" requests that the target agent
3883 (such as GDBserver) do the printing.
3885 set dprintf-function <expr>
3886 show dprintf-function
3887 set dprintf-channel <expr>
3888 show dprintf-channel
3889 Set the function and optional first argument to the call when using
3890 the "call" style of dynamic printf.
3892 set disconnected-dprintf on|off
3893 show disconnected-dprintf
3894 Control whether agent-style dynamic printfs continue to be in effect
3895 after GDB disconnects.
3897 * New configure options
3899 --with-auto-load-dir
3900 Configure default value for the 'set auto-load scripts-directory'
3901 setting above. It defaults to '$debugdir:$datadir/auto-load',
3902 $debugdir representing global debugging info directories (available
3903 via 'show debug-file-directory') and $datadir representing GDB's data
3904 directory (available via 'show data-directory').
3906 --with-auto-load-safe-path
3907 Configure default value for the 'set auto-load safe-path' setting
3908 above. It defaults to the --with-auto-load-dir setting.
3910 --without-auto-load-safe-path
3911 Set 'set auto-load safe-path' to '/', effectively disabling this
3914 * New remote packets
3916 z0/z1 conditional breakpoints extension
3918 The z0/z1 breakpoint insertion packets have been extended to carry
3919 a list of conditional expressions over to the remote stub depending on the
3920 condition evaluation mode. The use of this extension can be controlled
3921 via the "set remote conditional-breakpoints-packet" command.
3925 Specify the signals which the remote stub may pass to the debugged
3926 program without GDB involvement.
3928 * New command line options
3930 --init-command=FILE, -ix Like --command, -x but execute it
3931 before loading inferior.
3932 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3933 execute it before loading inferior.
3935 *** Changes in GDB 7.4
3937 * GDB now handles ambiguous linespecs more consistently; the existing
3938 FILE:LINE support has been expanded to other types of linespecs. A
3939 breakpoint will now be set on all matching locations in all
3940 inferiors, and locations will be added or removed according to
3943 * GDB now allows you to skip uninteresting functions and files when
3944 stepping with the "skip function" and "skip file" commands.
3946 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3947 and "show remote hardware-watchpoint-length-limit". These allows to
3948 set or show the maximum length limit (in bytes) of a remote
3949 target hardware watchpoint.
3951 This allows e.g. to use "unlimited" hardware watchpoints with the
3952 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3953 watchpoints are slower than real hardware watchpoints but are
3954 significantly faster than gdb software watchpoints.
3958 ** The register_pretty_printer function in module gdb.printing now takes
3959 an optional `replace' argument. If True, the new printer replaces any
3962 ** The "maint set python print-stack on|off" command has been
3963 deprecated and will be deleted in GDB 7.5.
3964 A new command: "set python print-stack none|full|message" has
3965 replaced it. Additionally, the default for "print-stack" is
3966 now "message", which just prints the error message without
3969 ** A prompt substitution hook (prompt_hook) is now available to the
3972 ** A new Python module, gdb.prompt has been added to the GDB Python
3973 modules library. This module provides functionality for
3974 escape sequences in prompts (used by set/show
3975 extended-prompt). These escape sequences are replaced by their
3976 corresponding value.
3978 ** Python commands and convenience-functions located in
3979 'data-directory'/python/gdb/command and
3980 'data-directory'/python/gdb/function are now automatically loaded
3983 ** Blocks now provide four new attributes. global_block and
3984 static_block will return the global and static blocks
3985 respectively. is_static and is_global are boolean attributes
3986 that indicate if the block is one of those two types.
3988 ** Symbols now provide the "type" attribute, the type of the symbol.
3990 ** The "gdb.breakpoint" function has been deprecated in favor of
3993 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3994 of a function. This class is based on the "finish" command
3995 available in the CLI.
3997 ** Type objects for struct and union types now allow access to
3998 the fields using standard Python dictionary (mapping) methods.
3999 For example, "some_type['myfield']" now works, as does
4000 "some_type.items()".
4002 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4005 ** A new function, "deep_items" has been added to the gdb.types
4006 module in the GDB Python modules library. This function returns
4007 an iterator over the fields of a struct or union type. Unlike
4008 the standard Python "iteritems" method, it will recursively traverse
4009 any anonymous fields.
4013 ** "*stopped" events can report several new "reason"s, such as
4016 ** Breakpoint changes are now notified using new async records, like
4017 "=breakpoint-modified".
4019 ** New command -ada-task-info.
4021 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4022 $sdir specifies the default system locations of shared libraries.
4023 $pdir specifies the directory where the libpthread used by the application
4026 GDB no longer looks in $sdir and $pdir after it has searched the directories
4027 mentioned in libthread-db-search-path. If you want to search those
4028 directories, they must be specified in libthread-db-search-path.
4029 The default value of libthread-db-search-path on GNU/Linux and Solaris
4030 systems is now "$sdir:$pdir".
4032 $pdir is not supported by gdbserver, it is currently ignored.
4033 $sdir is supported by gdbserver.
4035 * New configure option --with-iconv-bin.
4036 When using the internationalization support like the one in the GNU C
4037 library, GDB will invoke the "iconv" program to get a list of supported
4038 character sets. If this program lives in a non-standard location, one can
4039 use this option to specify where to find it.
4041 * When natively debugging programs on PowerPC BookE processors running
4042 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4043 watchpoints, which specify a mask in addition to an address to watch.
4044 The mask specifies that some bits of an address (the bits which are
4045 reset in the mask) should be ignored when matching the address accessed
4046 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4047 section in the user manual for more details.
4049 * The new option --once causes GDBserver to stop listening for connections once
4050 the first connection is made. The listening port used by GDBserver will
4051 become available after that.
4053 * New commands "info macros" and "alias" have been added.
4055 * New function parameters suffix @entry specifies value of function parameter
4056 at the time the function got called. Entry values are available only since
4062 "!" is now an alias of the "shell" command.
4063 Note that no space is needed between "!" and SHELL COMMAND.
4067 watch EXPRESSION mask MASK_VALUE
4068 The watch command now supports the mask argument which allows creation
4069 of masked watchpoints, if the current architecture supports this feature.
4071 info auto-load-scripts [REGEXP]
4072 This command was formerly named "maintenance print section-scripts".
4073 It is now generally useful and is no longer a maintenance-only command.
4075 info macro [-all] [--] MACRO
4076 The info macro command has new options `-all' and `--'. The first for
4077 printing all definitions of a macro. The second for explicitly specifying
4078 the end of arguments and the beginning of the macro name in case the macro
4079 name starts with a hyphen.
4081 collect[/s] EXPRESSIONS
4082 The tracepoint collect command now takes an optional modifier "/s"
4083 that directs it to dereference pointer-to-character types and
4084 collect the bytes of memory up to a zero byte. The behavior is
4085 similar to what you see when you use the regular print command on a
4086 string. An optional integer following the "/s" sets a bound on the
4087 number of bytes that will be collected.
4090 The trace start command now interprets any supplied arguments as a
4091 note to be recorded with the trace run, with an effect similar to
4092 setting the variable trace-notes.
4095 The trace stop command now interprets any arguments as a note to be
4096 mentioned along with the tstatus report that the trace was stopped
4097 with a command. The effect is similar to setting the variable
4100 * Tracepoints can now be enabled and disabled at any time after a trace
4101 experiment has been started using the standard "enable" and "disable"
4102 commands. It is now possible to start a trace experiment with no enabled
4103 tracepoints; GDB will display a warning, but will allow the experiment to
4104 begin, assuming that tracepoints will be enabled as needed while the trace
4107 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4108 locations with 4-byte instructions, when they were previously
4109 limited to locations with instructions of 5 bytes or longer.
4113 set debug dwarf2-read
4114 show debug dwarf2-read
4115 Turns on or off display of debugging messages related to reading
4116 DWARF debug info. The default is off.
4118 set debug symtab-create
4119 show debug symtab-create
4120 Turns on or off display of debugging messages related to symbol table
4121 creation. The default is off.
4124 show extended-prompt
4125 Set the GDB prompt, and allow escape sequences to be inserted to
4126 display miscellaneous information (see 'help set extended-prompt'
4127 for the list of sequences). This prompt (and any information
4128 accessed through the escape sequences) is updated every time the
4129 prompt is displayed.
4131 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4132 show print entry-values
4133 Set printing of frame argument values at function entry. In some cases
4134 GDB can determine the value of function argument which was passed by the
4135 function caller, even if the value was modified inside the called function.
4137 set debug entry-values
4138 show debug entry-values
4139 Control display of debugging info for determining frame argument values at
4140 function entry and virtual tail call frames.
4142 set basenames-may-differ
4143 show basenames-may-differ
4144 Set whether a source file may have multiple base names.
4145 (A "base name" is the name of a file with the directory part removed.
4146 Example: The base name of "/home/user/hello.c" is "hello.c".)
4147 If set, GDB will canonicalize file names (e.g., expand symlinks)
4148 before comparing them. Canonicalization is an expensive operation,
4149 but it allows the same file be known by more than one base name.
4150 If not set (the default), all source files are assumed to have just
4151 one base name, and gdb will do file name comparisons more efficiently.
4157 Set a user name and notes for the current and any future trace runs.
4158 This is useful for long-running and/or disconnected traces, to
4159 inform others (or yourself) as to who is running the trace, supply
4160 contact information, or otherwise explain what is going on.
4162 set trace-stop-notes
4163 show trace-stop-notes
4164 Set a note attached to the trace run, that is displayed when the
4165 trace has been stopped by a tstop command. This is useful for
4166 instance as an explanation, if you are stopping a trace run that was
4167 started by someone else.
4169 * New remote packets
4173 Dynamically enable a tracepoint in a started trace experiment.
4177 Dynamically disable a tracepoint in a started trace experiment.
4181 Set the user and notes of the trace run.
4185 Query the current status of a tracepoint.
4189 Query the minimum length of instruction at which a fast tracepoint may
4192 * Dcache size (number of lines) and line-size are now runtime-configurable
4193 via "set dcache line" and "set dcache line-size" commands.
4197 Texas Instruments TMS320C6x tic6x-*-*
4201 Renesas RL78 rl78-*-elf
4203 *** Changes in GDB 7.3.1
4205 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4207 *** Changes in GDB 7.3
4209 * GDB has a new command: "thread find [REGEXP]".
4210 It finds the thread id whose name, target id, or thread extra info
4211 matches the given regular expression.
4213 * The "catch syscall" command now works on mips*-linux* targets.
4215 * The -data-disassemble MI command now supports modes 2 and 3 for
4216 dumping the instruction opcodes.
4218 * New command line options
4220 -data-directory DIR Specify DIR as the "data-directory".
4221 This is mostly for testing purposes.
4223 * The "maint set python auto-load on|off" command has been renamed to
4224 "set auto-load-scripts on|off".
4226 * GDB has a new command: "set directories".
4227 It is like the "dir" command except that it replaces the
4228 source path list instead of augmenting it.
4230 * GDB now understands thread names.
4232 On GNU/Linux, "info threads" will display the thread name as set by
4233 prctl or pthread_setname_np.
4235 There is also a new command, "thread name", which can be used to
4236 assign a name internally for GDB to display.
4239 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4240 has been integrated into GDB.
4244 ** The function gdb.Write now accepts an optional keyword 'stream'.
4245 This keyword, when provided, will direct the output to either
4246 stdout, stderr, or GDB's logging output.
4248 ** Parameters can now be be sub-classed in Python, and in particular
4249 you may implement the get_set_doc and get_show_doc functions.
4250 This improves how Parameter set/show documentation is processed
4251 and allows for more dynamic content.
4253 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4254 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4255 have an is_valid method.
4257 ** Breakpoints can now be sub-classed in Python, and in particular
4258 you may implement a 'stop' function that is executed each time
4259 the inferior reaches that breakpoint.
4261 ** New function gdb.lookup_global_symbol looks up a global symbol.
4263 ** GDB values in Python are now callable if the value represents a
4264 function. For example, if 'some_value' represents a function that
4265 takes two integer parameters and returns a value, you can call
4266 that function like so:
4268 result = some_value (10,20)
4270 ** Module gdb.types has been added.
4271 It contains a collection of utilities for working with gdb.Types objects:
4272 get_basic_type, has_field, make_enum_dict.
4274 ** Module gdb.printing has been added.
4275 It contains utilities for writing and registering pretty-printers.
4276 New classes: PrettyPrinter, SubPrettyPrinter,
4277 RegexpCollectionPrettyPrinter.
4278 New function: register_pretty_printer.
4280 ** New commands "info pretty-printers", "enable pretty-printer" and
4281 "disable pretty-printer" have been added.
4283 ** gdb.parameter("directories") is now available.
4285 ** New function gdb.newest_frame returns the newest frame in the
4288 ** The gdb.InferiorThread class has a new "name" attribute. This
4289 holds the thread's name.
4291 ** Python Support for Inferior events.
4292 Python scripts can add observers to be notified of events
4293 occurring in the process being debugged.
4294 The following events are currently supported:
4295 - gdb.events.cont Continue event.
4296 - gdb.events.exited Inferior exited event.
4297 - gdb.events.stop Signal received, and Breakpoint hit events.
4301 ** GDB now puts template parameters in scope when debugging in an
4302 instantiation. For example, if you have:
4304 template<int X> int func (void) { return X; }
4306 then if you step into func<5>, "print X" will show "5". This
4307 feature requires proper debuginfo support from the compiler; it
4308 was added to GCC 4.5.
4310 ** The motion commands "next", "finish", "until", and "advance" now
4311 work better when exceptions are thrown. In particular, GDB will
4312 no longer lose control of the inferior; instead, the GDB will
4313 stop the inferior at the point at which the exception is caught.
4314 This functionality requires a change in the exception handling
4315 code that was introduced in GCC 4.5.
4317 * GDB now follows GCC's rules on accessing volatile objects when
4318 reading or writing target state during expression evaluation.
4319 One notable difference to prior behavior is that "print x = 0"
4320 no longer generates a read of x; the value of the assignment is
4321 now always taken directly from the value being assigned.
4323 * GDB now has some support for using labels in the program's source in
4324 linespecs. For instance, you can use "advance label" to continue
4325 execution to a label.
4327 * GDB now has support for reading and writing a new .gdb_index
4328 section. This section holds a fast index of DWARF debugging
4329 information and can be used to greatly speed up GDB startup and
4330 operation. See the documentation for `save gdb-index' for details.
4332 * The "watch" command now accepts an optional "-location" argument.
4333 When used, this causes GDB to watch the memory referred to by the
4334 expression. Such a watchpoint is never deleted due to it going out
4337 * GDB now supports thread debugging of core dumps on GNU/Linux.
4339 GDB now activates thread debugging using the libthread_db library
4340 when debugging GNU/Linux core dumps, similarly to when debugging
4341 live processes. As a result, when debugging a core dump file, GDB
4342 is now able to display pthread_t ids of threads. For example, "info
4343 threads" shows the same output as when debugging the process when it
4344 was live. In earlier releases, you'd see something like this:
4347 * 1 LWP 6780 main () at main.c:10
4349 While now you see this:
4352 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4354 It is also now possible to inspect TLS variables when debugging core
4357 When debugging a core dump generated on a machine other than the one
4358 used to run GDB, you may need to point GDB at the correct
4359 libthread_db library with the "set libthread-db-search-path"
4360 command. See the user manual for more details on this command.
4362 * When natively debugging programs on PowerPC BookE processors running
4363 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4364 which stop execution of the inferior whenever it executes an instruction
4365 at any address within the specified range. See the "PowerPC Embedded"
4366 section in the user manual for more details.
4368 * New features in the GDB remote stub, GDBserver
4370 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4371 and i686 LynxOS (version 5.x).
4373 ** GDBserver is now supported on Blackfin Linux.
4375 * New native configurations
4377 ia64 HP-UX ia64-*-hpux*
4381 Analog Devices, Inc. Blackfin Processor bfin-*
4383 * Ada task switching is now supported on sparc-elf targets when
4384 debugging a program using the Ravenscar Profile. For more information,
4385 see the "Tasking Support when using the Ravenscar Profile" section
4386 in the GDB user manual.
4388 * Guile support was removed.
4390 * New features in the GNU simulator
4392 ** The --map-info flag lists all known core mappings.
4394 ** CFI flashes may be simulated via the "cfi" device.
4396 *** Changes in GDB 7.2
4398 * Shared library support for remote targets by default
4400 When GDB is configured for a generic, non-OS specific target, like
4401 for example, --target=arm-eabi or one of the many *-*-elf targets,
4402 GDB now queries remote stubs for loaded shared libraries using the
4403 `qXfer:libraries:read' packet. Previously, shared library support
4404 was always disabled for such configurations.
4408 ** Argument Dependent Lookup (ADL)
4410 In C++ ADL lookup directs function search to the namespaces of its
4411 arguments even if the namespace has not been imported.
4421 Here the compiler will search for `foo' in the namespace of 'b'
4422 and find A::foo. GDB now supports this. This construct is commonly
4423 used in the Standard Template Library for operators.
4425 ** Improved User Defined Operator Support
4427 In addition to member operators, GDB now supports lookup of operators
4428 defined in a namespace and imported with a `using' directive, operators
4429 defined in the global scope, operators imported implicitly from an
4430 anonymous namespace, and the ADL operators mentioned in the previous
4432 GDB now also supports proper overload resolution for all the previously
4433 mentioned flavors of operators.
4435 ** static const class members
4437 Printing of static const class members that are initialized in the
4438 class definition has been fixed.
4440 * Windows Thread Information Block access.
4442 On Windows targets, GDB now supports displaying the Windows Thread
4443 Information Block (TIB) structure. This structure is visible either
4444 by using the new command `info w32 thread-information-block' or, by
4445 dereferencing the new convenience variable named `$_tlb', a
4446 thread-specific pointer to the TIB. This feature is also supported
4447 when remote debugging using GDBserver.
4449 * Static tracepoints
4451 Static tracepoints are calls in the user program into a tracing
4452 library. One such library is a port of the LTTng kernel tracer to
4453 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4454 When debugging with GDBserver, GDB now supports combining the GDB
4455 tracepoint machinery with such libraries. For example: the user can
4456 use GDB to probe a static tracepoint marker (a call from the user
4457 program into the tracing library) with the new "strace" command (see
4458 "New commands" below). This creates a "static tracepoint" in the
4459 breakpoint list, that can be manipulated with the same feature set
4460 as fast and regular tracepoints. E.g., collect registers, local and
4461 global variables, collect trace state variables, and define
4462 tracepoint conditions. In addition, the user can collect extra
4463 static tracepoint marker specific data, by collecting the new
4464 $_sdata internal variable. When analyzing the trace buffer, you can
4465 inspect $_sdata like any other variable available to GDB. For more
4466 information, see the "Tracepoints" chapter in GDB user manual. New
4467 remote packets have been defined to support static tracepoints, see
4468 the "New remote packets" section below.
4470 * Better reconstruction of tracepoints after disconnected tracing
4472 GDB will attempt to download the original source form of tracepoint
4473 definitions when starting a trace run, and then will upload these
4474 upon reconnection to the target, resulting in a more accurate
4475 reconstruction of the tracepoints that are in use on the target.
4479 You can now exercise direct control over the ways that GDB can
4480 affect your program. For instance, you can disallow the setting of
4481 breakpoints, so that the program can run continuously (assuming
4482 non-stop mode). In addition, the "observer" variable is available
4483 to switch all of the different controls; in observer mode, GDB
4484 cannot affect the target's behavior at all, which is useful for
4485 tasks like diagnosing live systems in the field.
4487 * The new convenience variable $_thread holds the number of the
4490 * New remote packets
4494 Return the address of the Windows Thread Information Block of a given thread.
4498 In response to several of the tracepoint packets, the target may now
4499 also respond with a number of intermediate `qRelocInsn' request
4500 packets before the final result packet, to have GDB handle
4501 relocating an instruction to execute at a different address. This
4502 is particularly useful for stubs that support fast tracepoints. GDB
4503 reports support for this feature in the qSupported packet.
4507 List static tracepoint markers in the target program.
4511 List static tracepoint markers at a given address in the target
4514 qXfer:statictrace:read
4516 Read the static trace data collected (by a `collect $_sdata'
4517 tracepoint action). The remote stub reports support for this packet
4518 to gdb's qSupported query.
4522 Send the current settings of GDB's permission flags.
4526 Send part of the source (textual) form of a tracepoint definition,
4527 which includes location, conditional, and action list.
4529 * The source command now accepts a -s option to force searching for the
4530 script in the source search path even if the script name specifies
4533 * New features in the GDB remote stub, GDBserver
4535 - GDBserver now support tracepoints (including fast tracepoints, and
4536 static tracepoints). The feature is currently supported by the
4537 i386-linux and amd64-linux builds. See the "Tracepoints support
4538 in gdbserver" section in the manual for more information.
4540 GDBserver JIT compiles the tracepoint's conditional agent
4541 expression bytecode into native code whenever possible for low
4542 overhead dynamic tracepoints conditionals. For such tracepoints,
4543 an expression that examines program state is evaluated when the
4544 tracepoint is reached, in order to determine whether to capture
4545 trace data. If the condition is simple and false, processing the
4546 tracepoint finishes very quickly and no data is gathered.
4548 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4549 for static tracepoints support.
4551 - GDBserver now supports x86_64 Windows 64-bit debugging.
4553 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4554 it understands register description.
4556 * The --batch flag now disables pagination and queries.
4558 * X86 general purpose registers
4560 GDB now supports reading/writing byte, word and double-word x86
4561 general purpose registers directly. This means you can use, say,
4562 $ah or $ax to refer, respectively, to the byte register AH and
4563 16-bit word register AX that are actually portions of the 32-bit
4564 register EAX or 64-bit register RAX.
4566 * The `commands' command now accepts a range of breakpoints to modify.
4567 A plain `commands' following a command that creates multiple
4568 breakpoints affects all the breakpoints set by that command. This
4569 applies to breakpoints set by `rbreak', and also applies when a
4570 single `break' command creates multiple breakpoints (e.g.,
4571 breakpoints on overloaded c++ functions).
4573 * The `rbreak' command now accepts a filename specification as part of
4574 its argument, limiting the functions selected by the regex to those
4575 in the specified file.
4577 * Support for remote debugging Windows and SymbianOS shared libraries
4578 from Unix hosts has been improved. Non Windows GDB builds now can
4579 understand target reported file names that follow MS-DOS based file
4580 system semantics, such as file names that include drive letters and
4581 use the backslash character as directory separator. This makes it
4582 possible to transparently use the "set sysroot" and "set
4583 solib-search-path" on Unix hosts to point as host copies of the
4584 target's shared libraries. See the new command "set
4585 target-file-system-kind" described below, and the "Commands to
4586 specify files" section in the user manual for more information.
4590 eval template, expressions...
4591 Convert the values of one or more expressions under the control
4592 of the string template to a command line, and call it.
4594 set target-file-system-kind unix|dos-based|auto
4595 show target-file-system-kind
4596 Set or show the assumed file system kind for target reported file
4599 save breakpoints <filename>
4600 Save all current breakpoint definitions to a file suitable for use
4601 in a later debugging session. To read the saved breakpoint
4602 definitions, use the `source' command.
4604 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4607 info static-tracepoint-markers
4608 Display information about static tracepoint markers in the target.
4610 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4611 Define a static tracepoint by probing a marker at the given
4612 function, line, address, or marker ID.
4616 Enable and disable observer mode.
4618 set may-write-registers on|off
4619 set may-write-memory on|off
4620 set may-insert-breakpoints on|off
4621 set may-insert-tracepoints on|off
4622 set may-insert-fast-tracepoints on|off
4623 set may-interrupt on|off
4624 Set individual permissions for GDB effects on the target. Note that
4625 some of these settings can have undesirable or surprising
4626 consequences, particularly when changed in the middle of a session.
4627 For instance, disabling the writing of memory can prevent
4628 breakpoints from being inserted, cause single-stepping to fail, or
4629 even crash your program, if you disable after breakpoints have been
4630 inserted. However, GDB should not crash.
4632 set record memory-query on|off
4633 show record memory-query
4634 Control whether to stop the inferior if memory changes caused
4635 by an instruction cannot be recorded.
4640 The disassemble command now supports "start,+length" form of two arguments.
4644 ** GDB now provides a new directory location, called the python directory,
4645 where Python scripts written for GDB can be installed. The location
4646 of that directory is <data-directory>/python, where <data-directory>
4647 is the GDB data directory. For more details, see section `Scripting
4648 GDB using Python' in the manual.
4650 ** The GDB Python API now has access to breakpoints, symbols, symbol
4651 tables, program spaces, inferiors, threads and frame's code blocks.
4652 Additionally, GDB Parameters can now be created from the API, and
4653 manipulated via set/show in the CLI.
4655 ** New functions gdb.target_charset, gdb.target_wide_charset,
4656 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4658 ** New exception gdb.GdbError.
4660 ** Pretty-printers are now also looked up in the current program space.
4662 ** Pretty-printers can now be individually enabled and disabled.
4664 ** GDB now looks for names of Python scripts to auto-load in a
4665 special section named `.debug_gdb_scripts', in addition to looking
4666 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4668 * Tracepoint actions were unified with breakpoint commands. In particular,
4669 there are no longer differences in "info break" output for breakpoints and
4670 tracepoints and the "commands" command can be used for both tracepoints and
4671 regular breakpoints.
4675 ARM Symbian arm*-*-symbianelf*
4677 * D language support.
4678 GDB now supports debugging programs written in the D programming
4681 * GDB now supports the extended ptrace interface for PowerPC which is
4682 available since Linux kernel version 2.6.34. This automatically enables
4683 any hardware breakpoints and additional hardware watchpoints available in
4684 the processor. The old ptrace interface exposes just one hardware
4685 watchpoint and no hardware breakpoints.
4687 * GDB is now able to use the Data Value Compare (DVC) register available on
4688 embedded PowerPC processors to implement in hardware simple watchpoint
4689 conditions of the form:
4691 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4693 This works in native GDB running on Linux kernels with the extended ptrace
4694 interface mentioned above.
4696 *** Changes in GDB 7.1
4700 ** Namespace Support
4702 GDB now supports importing of namespaces in C++. This enables the
4703 user to inspect variables from imported namespaces. Support for
4704 namepace aliasing has also been added. So, if a namespace is
4705 aliased in the current scope (e.g. namepace C=A; ) the user can
4706 print variables using the alias (e.g. (gdb) print C::x).
4710 All known bugs relating to the printing of virtual base class were
4711 fixed. It is now possible to call overloaded static methods using a
4716 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4717 and reinterpret_cast<> are now handled by the C++ expression parser.
4721 Xilinx MicroBlaze microblaze-*-*
4726 Xilinx MicroBlaze microblaze
4729 * Multi-program debugging.
4731 GDB now has support for multi-program (a.k.a. multi-executable or
4732 multi-exec) debugging. This allows for debugging multiple inferiors
4733 simultaneously each running a different program under the same GDB
4734 session. See "Debugging Multiple Inferiors and Programs" in the
4735 manual for more information. This implied some user visible changes
4736 in the multi-inferior support. For example, "info inferiors" now
4737 lists inferiors that are not running yet or that have exited
4738 already. See also "New commands" and "New options" below.
4740 * New tracing features
4742 GDB's tracepoint facility now includes several new features:
4744 ** Trace state variables
4746 GDB tracepoints now include support for trace state variables, which
4747 are variables managed by the target agent during a tracing
4748 experiment. They are useful for tracepoints that trigger each
4749 other, so for instance one tracepoint can count hits in a variable,
4750 and then a second tracepoint has a condition that is true when the
4751 count reaches a particular value. Trace state variables share the
4752 $-syntax of GDB convenience variables, and can appear in both
4753 tracepoint actions and condition expressions. Use the "tvariable"
4754 command to create, and "info tvariables" to view; see "Trace State
4755 Variables" in the manual for more detail.
4759 GDB now includes an option for defining fast tracepoints, which
4760 targets may implement more efficiently, such as by installing a jump
4761 into the target agent rather than a trap instruction. The resulting
4762 speedup can be by two orders of magnitude or more, although the
4763 tradeoff is that some program locations on some target architectures
4764 might not allow fast tracepoint installation, for instance if the
4765 instruction to be replaced is shorter than the jump. To request a
4766 fast tracepoint, use the "ftrace" command, with syntax identical to
4767 the regular trace command.
4769 ** Disconnected tracing
4771 It is now possible to detach GDB from the target while it is running
4772 a trace experiment, then reconnect later to see how the experiment
4773 is going. In addition, a new variable disconnected-tracing lets you
4774 tell the target agent whether to continue running a trace if the
4775 connection is lost unexpectedly.
4779 GDB now has the ability to save the trace buffer into a file, and
4780 then use that file as a target, similarly to you can do with
4781 corefiles. You can select trace frames, print data that was
4782 collected in them, and use tstatus to display the state of the
4783 tracing run at the moment that it was saved. To create a trace
4784 file, use "tsave <filename>", and to use it, do "target tfile
4787 ** Circular trace buffer
4789 You can ask the target agent to handle the trace buffer as a
4790 circular buffer, discarding the oldest trace frames to make room for
4791 newer ones, by setting circular-trace-buffer to on. This feature may
4792 not be available for all target agents.
4797 The disassemble command, when invoked with two arguments, now requires
4798 the arguments to be comma-separated.
4801 The info variables command now displays variable definitions. Files
4802 which only declare a variable are not shown.
4805 The source command is now capable of sourcing Python scripts.
4806 This feature is dependent on the debugger being build with Python
4809 Related to this enhancement is also the introduction of a new command
4810 "set script-extension" (see below).
4812 * New commands (for set/show, see "New options" below)
4814 record save [<FILENAME>]
4815 Save a file (in core file format) containing the process record
4816 execution log for replay debugging at a later time.
4818 record restore <FILENAME>
4819 Restore the process record execution log that was saved at an
4820 earlier time, for replay debugging.
4822 add-inferior [-copies <N>] [-exec <FILENAME>]
4825 clone-inferior [-copies <N>] [ID]
4826 Make a new inferior ready to execute the same program another
4827 inferior has loaded.
4832 maint info program-spaces
4833 List the program spaces loaded into GDB.
4835 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4836 show remote interrupt-sequence
4837 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4838 as the sequence to the remote target in order to interrupt the execution.
4839 Ctrl-C is a default. Some system prefers BREAK which is high level of
4840 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4841 Magic SysRq g. It is BREAK signal and character 'g'.
4843 set remote interrupt-on-connect [on | off]
4844 show remote interrupt-on-connect
4845 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4846 remote target when gdb connects to it. This is needed when you debug
4849 set remotebreak [on | off]
4851 Deprecated. Use "set/show remote interrupt-sequence" instead.
4853 tvariable $NAME [ = EXP ]
4854 Create or modify a trace state variable.
4857 List trace state variables and their values.
4859 delete tvariable $NAME ...
4860 Delete one or more trace state variables.
4863 Evaluate the given expressions without collecting anything into the
4864 trace buffer. (Valid in tracepoint actions only.)
4866 ftrace FN / FILE:LINE / *ADDR
4867 Define a fast tracepoint at the given function, line, or address.
4869 * New expression syntax
4871 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4872 GDB now parses 0b101010 identically with 42.
4876 set follow-exec-mode new|same
4877 show follow-exec-mode
4878 Control whether GDB reuses the same inferior across an exec call or
4879 creates a new one. This is useful to be able to restart the old
4880 executable after the inferior having done an exec call.
4882 set default-collect EXPR, ...
4883 show default-collect
4884 Define a list of expressions to be collected at each tracepoint.
4885 This is a useful way to ensure essential items are not overlooked,
4886 such as registers or a critical global variable.
4888 set disconnected-tracing
4889 show disconnected-tracing
4890 If set to 1, the target is instructed to continue tracing if it
4891 loses its connection to GDB. If 0, the target is to stop tracing
4894 set circular-trace-buffer
4895 show circular-trace-buffer
4896 If set to on, the target is instructed to use a circular trace buffer
4897 and discard the oldest trace frames instead of stopping the trace due
4898 to a full trace buffer. If set to off, the trace stops when the buffer
4899 fills up. Some targets may not support this.
4901 set script-extension off|soft|strict
4902 show script-extension
4903 If set to "off", the debugger does not perform any script language
4904 recognition, and all sourced files are assumed to be GDB scripts.
4905 If set to "soft" (the default), files are sourced according to
4906 filename extension, falling back to GDB scripts if the first
4908 If set to "strict", files are sourced according to filename extension.
4910 set ada trust-PAD-over-XVS on|off
4911 show ada trust-PAD-over-XVS
4912 If off, activate a workaround against a bug in the debugging information
4913 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4914 the GCC sources for more information about the GNAT encoding and
4915 PAD types in particular). It is always safe to set this option to
4916 off, but this introduces a slight performance penalty. The default
4919 * Python API Improvements
4921 ** GDB provides the new class gdb.LazyString. This is useful in
4922 some pretty-printing cases. The new method gdb.Value.lazy_string
4923 provides a simple way to create objects of this type.
4925 ** The fields returned by gdb.Type.fields now have an
4926 `is_base_class' attribute.
4928 ** The new method gdb.Type.range returns the range of an array type.
4930 ** The new method gdb.parse_and_eval can be used to parse and
4931 evaluate an expression.
4933 * New remote packets
4936 Define a trace state variable.
4939 Get the current value of a trace state variable.
4942 Set desired tracing behavior upon disconnection.
4945 Set the trace buffer to be linear or circular.
4948 Get data about the tracepoints currently in use.
4952 Process record now works correctly with hardware watchpoints.
4954 Multiple bug fixes have been made to the mips-irix port, making it
4955 much more reliable. In particular:
4956 - Debugging threaded applications is now possible again. Previously,
4957 GDB would hang while starting the program, or while waiting for
4958 the program to stop at a breakpoint.
4959 - Attaching to a running process no longer hangs.
4960 - An error occurring while loading a core file has been fixed.
4961 - Changing the value of the PC register now works again. This fixes
4962 problems observed when using the "jump" command, or when calling
4963 a function from GDB, or even when assigning a new value to $pc.
4964 - With the "finish" and "return" commands, the return value for functions
4965 returning a small array is now correctly printed.
4966 - It is now possible to break on shared library code which gets executed
4967 during a shared library init phase (code executed while executing
4968 their .init section). Previously, the breakpoint would have no effect.
4969 - GDB is now able to backtrace through the signal handler for
4970 non-threaded programs.
4972 PIE (Position Independent Executable) programs debugging is now supported.
4973 This includes debugging execution of PIC (Position Independent Code) shared
4974 libraries although for that, it should be possible to run such libraries as an
4977 *** Changes in GDB 7.0
4979 * GDB now has an interface for JIT compilation. Applications that
4980 dynamically generate code can create symbol files in memory and register
4981 them with GDB. For users, the feature should work transparently, and
4982 for JIT developers, the interface is documented in the GDB manual in the
4983 "JIT Compilation Interface" chapter.
4985 * Tracepoints may now be conditional. The syntax is as for
4986 breakpoints; either an "if" clause appended to the "trace" command,
4987 or the "condition" command is available. GDB sends the condition to
4988 the target for evaluation using the same bytecode format as is used
4989 for tracepoint actions.
4991 * The disassemble command now supports: an optional /r modifier, print the
4992 raw instructions in hex as well as in symbolic form, and an optional /m
4993 modifier to print mixed source+assembly.
4995 * Process record and replay
4997 In a architecture environment that supports ``process record and
4998 replay'', ``process record and replay'' target can record a log of
4999 the process execution, and replay it with both forward and reverse
5002 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5003 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5004 set execution-direction {forward|reverse}, for targets that support
5007 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5008 feature is available with a native GDB running on kernel version
5011 * GDB now has support for multi-byte and wide character sets on the
5012 target. Strings whose character type is wchar_t, char16_t, or
5013 char32_t are now correctly printed. GDB supports wide- and unicode-
5014 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5015 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5016 `printf'. This feature requires iconv to work properly; if your
5017 system does not have a working iconv, GDB can use GNU libiconv. See
5018 the installation instructions for more information.
5020 * GDB now supports automatic retrieval of shared library files from
5021 remote targets. To use this feature, specify a system root that begins
5022 with the `remote:' prefix, either via the `set sysroot' command or via
5023 the `--with-sysroot' configure-time option.
5025 * "info sharedlibrary" now takes an optional regex of libraries to show,
5026 and it now reports if a shared library has no debugging information.
5028 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5029 now complete on file names.
5031 * When completing in expressions, gdb will attempt to limit
5032 completions to allowable structure or union fields, where appropriate.
5033 For instance, consider:
5035 # struct example { int f1; double f2; };
5036 # struct example variable;
5039 If the user types TAB at the end of this command line, the available
5040 completions will be "f1" and "f2".
5042 * Inlined functions are now supported. They show up in backtraces, and
5043 the "step", "next", and "finish" commands handle them automatically.
5045 * GDB now supports the token-splicing (##) and stringification (#)
5046 operators when expanding macros. It also supports variable-arity
5049 * GDB now supports inspecting extra signal information, exported by
5050 the new $_siginfo convenience variable. The feature is currently
5051 implemented on linux ARM, i386 and amd64.
5053 * GDB can now display the VFP floating point registers and NEON vector
5054 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5055 can provide these registers (requires Linux 2.6.30 or later). Remote
5056 and simulator targets may also provide them.
5058 * New remote packets
5061 Search memory for a sequence of bytes.
5064 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5065 operation over reliable transport links. Use of this packet is
5066 controlled by the `set remote noack-packet' command.
5069 Kill the process with the specified process ID. Use this in preference
5070 to `k' when multiprocess protocol extensions are supported.
5073 Obtains additional operating system information
5077 Read or write additional signal information.
5079 * Removed remote protocol undocumented extension
5081 An undocumented extension to the remote protocol's `S' stop reply
5082 packet that permitted the stub to pass a process id was removed.
5083 Remote servers should use the `T' stop reply packet instead.
5085 * GDB now supports multiple function calling conventions according to the
5086 DWARF-2 DW_AT_calling_convention function attribute.
5088 * The SH target utilizes the aforementioned change to distinguish between gcc
5089 and Renesas calling convention. It also adds the new CLI commands
5090 `set/show sh calling-convention'.
5092 * GDB can now read compressed debug sections, as produced by GNU gold
5093 with the --compress-debug-sections=zlib flag.
5095 * 64-bit core files are now supported on AIX.
5097 * Thread switching is now supported on Tru64.
5099 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5100 which will be allocated using malloc later in program execution.
5102 * The qXfer:libraries:read remote protocol packet now allows passing a
5103 list of section offsets.
5105 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5106 conditions handling signals delivered during attach or thread creation
5107 have also been fixed.
5109 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5110 From the user's standpoint, all unqualified instances of True and False
5111 are treated as the standard definitions, regardless of context.
5113 * GDB now parses C++ symbol and type names more flexibly. For
5116 template<typename T> class C { };
5119 GDB will now correctly handle all of:
5121 ptype C<char const *>
5122 ptype C<char const*>
5123 ptype C<const char *>
5124 ptype C<const char*>
5126 * New features in the GDB remote stub, gdbserver
5128 - The "--wrapper" command-line argument tells gdbserver to use a
5129 wrapper program to launch programs for debugging.
5131 - On PowerPC and S/390 targets, it is now possible to use a single
5132 gdbserver executable to debug both 32-bit and 64-bit programs.
5133 (This requires gdbserver itself to be built as a 64-bit executable.)
5135 - gdbserver uses the new noack protocol mode for TCP connections to
5136 reduce communications latency, if also supported and enabled in GDB.
5138 - Support for the sparc64-linux-gnu target is now included in
5141 - The amd64-linux build of gdbserver now supports debugging both
5142 32-bit and 64-bit programs.
5144 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5145 now support hardware watchpoints, and will use them automatically
5150 GDB now has support for scripting using Python. Whether this is
5151 available is determined at configure time.
5153 New GDB commands can now be written in Python.
5155 * Ada tasking support
5157 Ada tasks can now be inspected in GDB. The following commands have
5161 Print the list of Ada tasks.
5163 Print detailed information about task number N.
5165 Print the task number of the current task.
5167 Switch the context of debugging to task number N.
5169 * Support for user-defined prefixed commands. The "define" command can
5170 add new commands to existing prefixes, e.g. "target".
5172 * Multi-inferior, multi-process debugging.
5174 GDB now has generalized support for multi-inferior debugging. See
5175 "Debugging Multiple Inferiors" in the manual for more information.
5176 Although availability still depends on target support, the command
5177 set is more uniform now. The GNU/Linux specific multi-forks support
5178 has been migrated to this new framework. This implied some user
5179 visible changes; see "New commands" and also "Removed commands"
5182 * Target descriptions can now describe the target OS ABI. See the
5183 "Target Description Format" section in the user manual for more
5186 * Target descriptions can now describe "compatible" architectures
5187 to indicate that the target can execute applications for a different
5188 architecture in addition to those for the main target architecture.
5189 See the "Target Description Format" section in the user manual for
5192 * Multi-architecture debugging.
5194 GDB now includes general supports for debugging applications on
5195 hybrid systems that use more than one single processor architecture
5196 at the same time. Each such hybrid architecture still requires
5197 specific support to be added. The only hybrid architecture supported
5198 in this version of GDB is the Cell Broadband Engine.
5200 * GDB now supports integrated debugging of Cell/B.E. applications that
5201 use both the PPU and SPU architectures. To enable support for hybrid
5202 Cell/B.E. debugging, you need to configure GDB to support both the
5203 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5204 --enable-targets configure option.
5206 * Non-stop mode debugging.
5208 For some targets, GDB now supports an optional mode of operation in
5209 which you can examine stopped threads while other threads continue
5210 to execute freely. This is referred to as non-stop mode, with the
5211 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5212 section in the user manual for more information.
5214 To be able to support remote non-stop debugging, a remote stub needs
5215 to implement the non-stop mode remote protocol extensions, as
5216 described in the "Remote Non-Stop" section of the user manual. The
5217 GDB remote stub, gdbserver, has been adjusted to support these
5218 extensions on linux targets.
5220 * New commands (for set/show, see "New options" below)
5222 catch syscall [NAME(S) | NUMBER(S)]
5223 Catch system calls. Arguments, which should be names of system
5224 calls or their numbers, mean catch only those syscalls. Without
5225 arguments, every syscall will be caught. When the inferior issues
5226 any of the specified syscalls, GDB will stop and announce the system
5227 call, both when it is called and when its call returns. This
5228 feature is currently available with a native GDB running on the
5229 Linux Kernel, under the following architectures: x86, x86_64,
5230 PowerPC and PowerPC64.
5232 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5234 Search memory for a sequence of bytes.
5236 maint set python print-stack
5237 maint show python print-stack
5238 Show a stack trace when an error is encountered in a Python script.
5241 Invoke CODE by passing it to the Python interpreter.
5246 These allow macros to be defined, undefined, and listed
5250 Show operating system information about processes.
5253 List the inferiors currently under GDB's control.
5256 Switch focus to inferior number NUM.
5259 Detach from inferior number NUM.
5262 Kill inferior number NUM.
5266 set spu stop-on-load
5267 show spu stop-on-load
5268 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5270 set spu auto-flush-cache
5271 show spu auto-flush-cache
5272 Control whether to automatically flush the software-managed cache
5273 during Cell/B.E. debugging.
5275 set sh calling-convention
5276 show sh calling-convention
5277 Control the calling convention used when calling SH target functions.
5280 show debug timestamp
5281 Control display of timestamps with GDB debugging output.
5283 set disassemble-next-line
5284 show disassemble-next-line
5285 Control display of disassembled source lines or instructions when
5288 set remote noack-packet
5289 show remote noack-packet
5290 Set/show the use of remote protocol QStartNoAckMode packet. See above
5291 under "New remote packets."
5293 set remote query-attached-packet
5294 show remote query-attached-packet
5295 Control use of remote protocol `qAttached' (query-attached) packet.
5297 set remote read-siginfo-object
5298 show remote read-siginfo-object
5299 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5302 set remote write-siginfo-object
5303 show remote write-siginfo-object
5304 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5307 set remote reverse-continue
5308 show remote reverse-continue
5309 Control use of remote protocol 'bc' (reverse-continue) packet.
5311 set remote reverse-step
5312 show remote reverse-step
5313 Control use of remote protocol 'bs' (reverse-step) packet.
5315 set displaced-stepping
5316 show displaced-stepping
5317 Control displaced stepping mode. Displaced stepping is a way to
5318 single-step over breakpoints without removing them from the debuggee.
5319 Also known as "out-of-line single-stepping".
5322 show debug displaced
5323 Control display of debugging info for displaced stepping.
5325 maint set internal-error
5326 maint show internal-error
5327 Control what GDB does when an internal error is detected.
5329 maint set internal-warning
5330 maint show internal-warning
5331 Control what GDB does when an internal warning is detected.
5336 Use a wrapper program to launch programs for debugging.
5338 set multiple-symbols (all|ask|cancel)
5339 show multiple-symbols
5340 The value of this variable can be changed to adjust the debugger behavior
5341 when an expression or a breakpoint location contains an ambiguous symbol
5342 name (an overloaded function name, for instance).
5344 set breakpoint always-inserted
5345 show breakpoint always-inserted
5346 Keep breakpoints always inserted in the target, as opposed to inserting
5347 them when resuming the target, and removing them when the target stops.
5348 This option can improve debugger performance on slow remote targets.
5350 set arm fallback-mode (arm|thumb|auto)
5351 show arm fallback-mode
5352 set arm force-mode (arm|thumb|auto)
5354 These commands control how ARM GDB determines whether instructions
5355 are ARM or Thumb. The default for both settings is auto, which uses
5356 the current CPSR value for instructions without symbols; previous
5357 versions of GDB behaved as if "set arm fallback-mode arm".
5359 set arm unwind-secure-frames
5360 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5362 This can trigger security exceptions when unwinding exception stacks.
5364 set disable-randomization
5365 show disable-randomization
5366 Standalone programs run with the virtual address space randomization enabled
5367 by default on some platforms. This option keeps the addresses stable across
5368 multiple debugging sessions.
5372 Control whether other threads are stopped or not when some thread hits
5377 Requests that asynchronous execution is enabled in the target, if available.
5378 In this case, it's possible to resume target in the background, and interact
5379 with GDB while the target is running. "show target-async" displays the
5380 current state of asynchronous execution of the target.
5382 set target-wide-charset
5383 show target-wide-charset
5384 The target-wide-charset is the name of the character set that GDB
5385 uses when printing characters whose type is wchar_t.
5387 set tcp auto-retry (on|off)
5389 set tcp connect-timeout
5390 show tcp connect-timeout
5391 These commands allow GDB to retry failed TCP connections to a remote stub
5392 with a specified timeout period; this is useful if the stub is launched
5393 in parallel with GDB but may not be ready to accept connections immediately.
5395 set libthread-db-search-path
5396 show libthread-db-search-path
5397 Control list of directories which GDB will search for appropriate
5400 set schedule-multiple (on|off)
5401 show schedule-multiple
5402 Allow GDB to resume all threads of all processes or only threads of
5403 the current process.
5407 Use more aggressive caching for accesses to the stack. This improves
5408 performance of remote debugging (particularly backtraces) without
5409 affecting correctness.
5411 set interactive-mode (on|off|auto)
5412 show interactive-mode
5413 Control whether GDB runs in interactive mode (on) or not (off).
5414 When in interactive mode, GDB waits for the user to answer all
5415 queries. Otherwise, GDB does not wait and assumes the default
5416 answer. When set to auto (the default), GDB determines which
5417 mode to use based on the stdin settings.
5422 For program forks, this is replaced by the new more generic `info
5423 inferiors' command. To list checkpoints, you can still use the
5424 `info checkpoints' command, which was an alias for the `info forks'
5428 Replaced by the new `inferior' command. To switch between
5429 checkpoints, you can still use the `restart' command, which was an
5430 alias for the `fork' command.
5433 This is removed, since some targets don't have a notion of
5434 processes. To switch between processes, you can still use the
5435 `inferior' command using GDB's own inferior number.
5438 For program forks, this is replaced by the new more generic `kill
5439 inferior' command. To delete a checkpoint, you can still use the
5440 `delete checkpoint' command, which was an alias for the `delete
5444 For program forks, this is replaced by the new more generic `detach
5445 inferior' command. To detach a checkpoint, you can still use the
5446 `detach checkpoint' command, which was an alias for the `detach
5449 * New native configurations
5451 x86/x86_64 Darwin i[34567]86-*-darwin*
5453 x86_64 MinGW x86_64-*-mingw*
5457 Lattice Mico32 lm32-*
5458 x86 DICOS i[34567]86-*-dicos*
5459 x86_64 DICOS x86_64-*-dicos*
5462 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5463 (mingw32ce) debugging.
5469 These commands were actually not implemented on any target.
5471 *** Changes in GDB 6.8
5473 * New native configurations
5475 NetBSD/hppa hppa*-*netbsd*
5476 Xtensa GNU/Linux xtensa*-*-linux*
5480 NetBSD/hppa hppa*-*-netbsd*
5481 Xtensa GNU/Linux xtensa*-*-linux*
5483 * Change in command line behavior -- corefiles vs. process ids.
5485 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5486 attaching to process NUMBER fails, GDB no longer attempts to open a
5487 core file named NUMBER. Attaching to a program using the -c option
5488 is no longer supported. Instead, use the '-p' or '--pid' options.
5490 * GDB can now be built as a native debugger for debugging Windows x86
5491 (mingw32) Portable Executable (PE) programs.
5493 * Pending breakpoints no longer change their number when their address
5496 * GDB now supports breakpoints with multiple locations,
5497 including breakpoints on C++ constructors, inside C++ templates,
5498 and in inlined functions.
5500 * GDB's ability to debug optimized code has been improved. GDB more
5501 accurately identifies function bodies and lexical blocks that occupy
5502 more than one contiguous range of addresses.
5504 * Target descriptions can now describe registers for PowerPC.
5506 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5507 registers on PowerPC targets.
5509 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5510 targets even when the libthread_db library is not available.
5512 * The GDB remote stub, gdbserver, now supports the new file transfer
5513 commands (remote put, remote get, and remote delete).
5515 * The GDB remote stub, gdbserver, now supports run and attach in
5516 extended-remote mode.
5518 * hppa*64*-*-hpux11* target broken
5519 The debugger is unable to start a program and fails with the following
5520 error: "Error trying to get information about dynamic linker".
5521 The gdb-6.7 release is also affected.
5523 * GDB now supports the --enable-targets= configure option to allow
5524 building a single GDB executable that supports multiple remote
5525 target architectures.
5527 * GDB now supports debugging C and C++ programs which use the
5528 Decimal Floating Point extension. In addition, the PowerPC target
5529 now has a set of pseudo-registers to inspect decimal float values
5530 stored in two consecutive float registers.
5532 * The -break-insert MI command can optionally create pending
5535 * Improved support for debugging Ada
5536 Many improvements to the Ada language support have been made. These
5538 - Better support for Ada2005 interface types
5539 - Improved handling of arrays and slices in general
5540 - Better support for Taft-amendment types
5541 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5543 - Improved command completion in Ada
5546 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5551 set print frame-arguments (all|scalars|none)
5552 show print frame-arguments
5553 The value of this variable can be changed to control which argument
5554 values should be printed by the debugger when displaying a frame.
5559 Transfer files to and from a remote target, and delete remote files.
5566 Transfer files to and from a remote target, and delete remote files.
5568 * New remote packets
5575 Open, close, read, write, and delete files on the remote system.
5578 Attach to an existing process on the remote system, in extended-remote
5582 Run a new process on the remote system, in extended-remote mode.
5584 *** Changes in GDB 6.7
5586 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5587 bfd, libiberty and opcodes, as revealed by static analysis donated by
5588 Coverity, Inc. (http://scan.coverity.com).
5590 * When looking up multiply-defined global symbols, GDB will now prefer the
5591 symbol definition in the current shared library if it was built using the
5592 -Bsymbolic linker option.
5594 * When the Text User Interface (TUI) is not configured, GDB will now
5595 recognize the -tui command-line option and print a message that the TUI
5598 * The GDB remote stub, gdbserver, now has lower overhead for high
5599 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5601 * GDB for MIPS targets now autodetects whether a remote target provides
5602 32-bit or 64-bit register values.
5604 * Support for C++ member pointers has been improved.
5606 * GDB now understands XML target descriptions, which specify the
5607 target's overall architecture. GDB can read a description from
5608 a local file or over the remote serial protocol.
5610 * Vectors of single-byte data use a new integer type which is not
5611 automatically displayed as character or string data.
5613 * The /s format now works with the print command. It displays
5614 arrays of single-byte integers and pointers to single-byte integers
5617 * Target descriptions can now describe target-specific registers,
5618 for architectures which have implemented the support (currently
5619 only ARM, M68K, and MIPS).
5621 * GDB and the GDB remote stub, gdbserver, now support the XScale
5624 * The GDB remote stub, gdbserver, has been updated to support
5625 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5626 has been rewritten to use the standard GDB remote protocol.
5628 * GDB can now step into C++ functions which are called through thunks.
5630 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5632 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5633 layout. It also supports a TextSeg= and DataSeg= response when only
5634 segment base addresses (rather than offsets) are available.
5636 * The /i format now outputs any trailing branch delay slot instructions
5637 immediately following the last instruction within the count specified.
5639 * The GDB remote protocol "T" stop reply packet now supports a
5640 "library" response. Combined with the new "qXfer:libraries:read"
5641 packet, this response allows GDB to debug shared libraries on targets
5642 where the operating system manages the list of loaded libraries (e.g.
5643 Windows and SymbianOS).
5645 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5646 (DLLs) on Windows and Windows CE targets.
5648 * GDB now supports a faster verification that a .debug file matches its binary
5649 according to its build-id signature, if the signature is present.
5655 Enable or disable hardware flow control (RTS/CTS) on the serial port
5656 when debugging using remote targets.
5658 set mem inaccessible-by-default
5659 show mem inaccessible-by-default
5660 If the target supplies a memory map, for instance via the remote
5661 protocol's "qXfer:memory-map:read" packet, setting this variable
5662 prevents GDB from accessing memory outside the memory map. This
5663 is useful for targets with memory mapped registers or which react
5664 badly to accesses of unmapped address space.
5666 set breakpoint auto-hw
5667 show breakpoint auto-hw
5668 If the target supplies a memory map, for instance via the remote
5669 protocol's "qXfer:memory-map:read" packet, setting this variable
5670 lets GDB use hardware breakpoints automatically for memory regions
5671 where it can not use software breakpoints. This covers both the
5672 "break" command and internal breakpoints used for other commands
5673 including "next" and "finish".
5676 catch exception unhandled
5677 Stop the program execution when Ada exceptions are raised.
5680 Stop the program execution when an Ada assertion failed.
5684 Set an alternate system root for target files. This is a more
5685 general version of "set solib-absolute-prefix", which is now
5686 an alias to "set sysroot".
5689 Provide extended SPU facility status information. This set of
5690 commands is available only when debugging the Cell/B.E. SPU
5693 * New native configurations
5695 OpenBSD/sh sh*-*openbsd*
5698 unset tdesc filename
5700 Use the specified local file as an XML target description, and do
5701 not query the target for its built-in description.
5705 OpenBSD/sh sh*-*-openbsd*
5706 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5707 Toshiba Media Processor mep-elf
5709 * New remote packets
5712 Ignore the specified signals; pass them directly to the debugged program
5713 without stopping other threads or reporting them to GDB.
5715 qXfer:features:read:
5716 Read an XML target description from the target, which describes its
5721 Read or write contents of an spufs file on the target system. These
5722 packets are available only on the Cell/B.E. SPU architecture.
5724 qXfer:libraries:read:
5725 Report the loaded shared libraries. Combined with new "T" packet
5726 response, this packet allows GDB to debug shared libraries on
5727 targets where the operating system manages the list of loaded
5728 libraries (e.g. Windows and SymbianOS).
5732 Support for these obsolete configurations has been removed.
5740 i[34567]86-*-lynxos*
5741 i[34567]86-*-netware*
5742 i[34567]86-*-sco3.2v5*
5743 i[34567]86-*-sco3.2v4*
5745 i[34567]86-*-sysv4.2*
5748 i[34567]86-*-unixware2*
5749 i[34567]86-*-unixware*
5758 * Other removed features
5765 Various m68k-only ROM monitors.
5772 Various Renesas ROM monitors and debugging interfaces for SH and
5777 Support for a Macraigor serial interface to on-chip debugging.
5778 GDB does not directly support the newer parallel or USB
5783 A debug information format. The predecessor to DWARF 2 and
5784 DWARF 3, which are still supported.
5786 Support for the HP aCC compiler on HP-UX/PA-RISC
5788 SOM-encapsulated symbolic debugging information, automatic
5789 invocation of pxdb, and the aCC custom C++ ABI. This does not
5790 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5791 with aCC can still be debugged on an assembly level.
5793 MIPS ".pdr" sections
5795 A MIPS-specific format used to describe stack frame layout
5796 in debugging information.
5800 GDB could work with an older version of Guile to debug
5801 the interpreter and Scheme programs running in it.
5803 set mips stack-arg-size
5804 set mips saved-gpreg-size
5806 Use "set mips abi" to control parameter passing for MIPS.
5808 *** Changes in GDB 6.6
5813 Cell Broadband Engine SPU spu-elf
5815 * GDB can now be configured as a cross-debugger targeting native Windows
5816 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5817 running on a Windows system over TCP/IP to debug Windows programs.
5819 * The GDB remote stub, gdbserver, has been updated to support Windows and
5820 Cygwin debugging. Both single-threaded and multi-threaded programs are
5823 * The "set trust-readonly-sections" command works again. This command was
5824 broken in GDB 6.3, 6.4, and 6.5.
5826 * The "load" command now supports writing to flash memory, if the remote
5827 stub provides the required support.
5829 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5830 longer requires symbolic debug information (e.g. DWARF-2).
5835 unset substitute-path
5836 show substitute-path
5837 Manage a list of substitution rules that GDB uses to rewrite the name
5838 of the directories where the sources are located. This can be useful
5839 for instance when the sources were moved to a different location
5840 between compilation and debugging.
5844 Print each CLI command as it is executed. Each command is prefixed with
5845 a number of `+' symbols representing the nesting depth.
5846 The source command now has a `-v' option to enable the same feature.
5850 The ARM Demon monitor support (RDP protocol, "target rdp").
5852 Kernel Object Display, an embedded debugging feature which only worked with
5853 an obsolete version of Cisco IOS.
5855 The 'set download-write-size' and 'show download-write-size' commands.
5857 * New remote packets
5860 Tell a stub about GDB client features, and request remote target features.
5861 The first feature implemented is PacketSize, which allows the target to
5862 specify the size of packets it can handle - to minimize the number of
5863 packets required and improve performance when connected to a remote
5867 Fetch an OS auxilliary vector from the remote stub. This packet is a
5868 more efficient replacement for qPart:auxv:read.
5870 qXfer:memory-map:read:
5871 Fetch a memory map from the remote stub, including information about
5872 RAM, ROM, and flash memory devices.
5877 Erase and program a flash memory device.
5879 * Removed remote packets
5882 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5883 used it, and only gdbserver implemented it.
5885 *** Changes in GDB 6.5
5889 Renesas M32C/M16C m32c-elf
5891 Morpho Technologies ms1 ms1-elf
5895 init-if-undefined Initialize a convenience variable, but
5896 only if it doesn't already have a value.
5898 The following commands are presently only implemented for native GNU/Linux:
5900 checkpoint Save a snapshot of the program state.
5902 restart <n> Return the program state to a
5903 previously saved state.
5905 info checkpoints List currently saved checkpoints.
5907 delete-checkpoint <n> Delete a previously saved checkpoint.
5909 set|show detach-on-fork Tell gdb whether to detach from a newly
5910 forked process, or to keep debugging it.
5912 info forks List forks of the user program that
5913 are available to be debugged.
5915 fork <n> Switch to debugging one of several
5916 forks of the user program that are
5917 available to be debugged.
5919 delete-fork <n> Delete a fork from the list of forks
5920 that are available to be debugged (and
5921 kill the forked process).
5923 detach-fork <n> Delete a fork from the list of forks
5924 that are available to be debugged (and
5925 allow the process to continue).
5929 Morpho Technologies ms2 ms1-elf
5931 * Improved Windows host support
5933 GDB now builds as a cross debugger hosted on i686-mingw32, including
5934 native console support, and remote communications using either
5935 network sockets or serial ports.
5937 * Improved Modula-2 language support
5939 GDB can now print most types in the Modula-2 syntax. This includes:
5940 basic types, set types, record types, enumerated types, range types,
5941 pointer types and ARRAY types. Procedure var parameters are correctly
5942 printed and hexadecimal addresses and character constants are also
5943 written in the Modula-2 syntax. Best results can be obtained by using
5944 GNU Modula-2 together with the -gdwarf-2 command line option.
5948 The ARM rdi-share module.
5950 The Netware NLM debug server.
5952 *** Changes in GDB 6.4
5954 * New native configurations
5956 OpenBSD/arm arm*-*-openbsd*
5957 OpenBSD/mips64 mips64-*-openbsd*
5961 Morpho Technologies ms1 ms1-elf
5963 * New command line options
5965 --batch-silent As for --batch, but totally silent.
5966 --return-child-result The debugger will exist with the same value
5967 the child (debugged) program exited with.
5968 --eval-command COMMAND, -ex COMMAND
5969 Execute a single GDB CLI command. This may be
5970 specified multiple times and in conjunction
5971 with the --command (-x) option.
5973 * Deprecated commands removed
5975 The following commands, that were deprecated in 2000, have been
5979 set|show arm disassembly-flavor set|show arm disassembler
5980 othernames set arm disassembler
5981 set|show remotedebug set|show debug remote
5982 set|show archdebug set|show debug arch
5983 set|show eventdebug set|show debug event
5986 * New BSD user-level threads support
5988 It is now possible to debug programs using the user-level threads
5989 library on OpenBSD and FreeBSD. Currently supported (target)
5992 FreeBSD/amd64 x86_64-*-freebsd*
5993 FreeBSD/i386 i386-*-freebsd*
5994 OpenBSD/i386 i386-*-openbsd*
5996 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5997 are not yet supported.
5999 * New support for Matsushita MN10300 w/sim added
6000 (Work in progress). mn10300-elf.
6002 * REMOVED configurations and files
6004 VxWorks and the XDR protocol *-*-vxworks
6005 Motorola MCORE mcore-*-*
6006 National Semiconductor NS32000 ns32k-*-*
6008 * New "set print array-indexes" command
6010 After turning this setting "on", GDB prints the index of each element
6011 when displaying arrays. The default is "off" to preserve the previous
6014 * VAX floating point support
6016 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6018 * User-defined command support
6020 In addition to using $arg0..$arg9 for argument passing, it is now possible
6021 to use $argc to determine now many arguments have been passed. See the
6022 section on user-defined commands in the user manual for more information.
6024 *** Changes in GDB 6.3:
6026 * New command line option
6028 GDB now accepts -l followed by a number to set the timeout for remote
6031 * GDB works with GCC -feliminate-dwarf2-dups
6033 GDB now supports a more compact representation of DWARF-2 debug
6034 information using DW_FORM_ref_addr references. These are produced
6035 by GCC with the option -feliminate-dwarf2-dups and also by some
6036 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6037 to use -feliminate-dwarf2-dups.
6039 * Internationalization
6041 When supported by the host system, GDB will be built with
6042 internationalization (libintl). The task of marking up the sources is
6043 continued, we're looking forward to our first translation.
6047 Initial support for debugging programs compiled with the GNAT
6048 implementation of the Ada programming language has been integrated
6049 into GDB. In this release, support is limited to expression evaluation.
6051 * New native configurations
6053 GNU/Linux/m32r m32r-*-linux-gnu
6057 GDB's remote protocol now includes support for the 'p' packet. This
6058 packet is used to fetch individual registers from a remote inferior.
6060 * END-OF-LIFE registers[] compatibility module
6062 GDB's internal register infrastructure has been completely rewritten.
6063 The new infrastructure making possible the implementation of key new
6064 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6067 GDB 6.3 will be the last release to include the registers[]
6068 compatibility module that allowed out-of-date configurations to
6069 continue to work. This change directly impacts the following
6079 powerpc bdm protocol
6081 Unless there is activity to revive these configurations, they will be
6082 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6084 * OBSOLETE configurations and files
6086 Configurations that have been declared obsolete in this release have
6087 been commented out. Unless there is activity to revive these
6088 configurations, the next release of GDB will have their sources
6089 permanently REMOVED.
6098 *** Changes in GDB 6.2.1:
6100 * MIPS `break main; run' gave an heuristic-fence-post warning
6102 When attempting to run even a simple program, a warning about
6103 heuristic-fence-post being hit would be reported. This problem has
6106 * MIPS IRIX 'long double' crashed GDB
6108 When examining a long double variable, GDB would get a segmentation
6109 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6110 IRIX long double values).
6114 A bug in the VAX stack code was causing problems with the "next"
6115 command. This problem has been fixed.
6117 *** Changes in GDB 6.2:
6119 * Fix for ``many threads''
6121 On GNU/Linux systems that use the NPTL threads library, a program
6122 rapidly creating and deleting threads would confuse GDB leading to the
6125 ptrace: No such process.
6126 thread_db_get_info: cannot get thread info: generic error
6128 This problem has been fixed.
6130 * "-async" and "-noasync" options removed.
6132 Support for the broken "-noasync" option has been removed (it caused
6135 * New ``start'' command.
6137 This command runs the program until the beginning of the main procedure.
6139 * New BSD Kernel Data Access Library (libkvm) interface
6141 Using ``target kvm'' it is now possible to debug kernel core dumps and
6142 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6143 platforms. Currently supported (native-only) configurations are:
6145 FreeBSD/amd64 x86_64-*-freebsd*
6146 FreeBSD/i386 i?86-*-freebsd*
6147 NetBSD/i386 i?86-*-netbsd*
6148 NetBSD/m68k m68*-*-netbsd*
6149 NetBSD/sparc sparc-*-netbsd*
6150 OpenBSD/amd64 x86_64-*-openbsd*
6151 OpenBSD/i386 i?86-*-openbsd*
6152 OpenBSD/m68k m68*-openbsd*
6153 OpenBSD/sparc sparc-*-openbsd*
6155 * Signal trampoline code overhauled
6157 Many generic problems with GDB's signal handling code have been fixed.
6158 These include: backtraces through non-contiguous stacks; recognition
6159 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6160 call; backtrace through a signal trampoline; step into and out of
6161 signal handlers; and single-stepping in the signal trampoline.
6163 Please note that kernel bugs are a limiting factor here. These
6164 features have been shown to work on an s390 GNU/Linux system that
6165 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6167 * Cygwin support for DWARF 2 added.
6169 * New native configurations
6171 GNU/Linux/hppa hppa*-*-linux*
6172 OpenBSD/hppa hppa*-*-openbsd*
6173 OpenBSD/m68k m68*-*-openbsd*
6174 OpenBSD/m88k m88*-*-openbsd*
6175 OpenBSD/powerpc powerpc-*-openbsd*
6176 NetBSD/vax vax-*-netbsd*
6177 OpenBSD/vax vax-*-openbsd*
6179 * END-OF-LIFE frame compatibility module
6181 GDB's internal frame infrastructure has been completely rewritten.
6182 The new infrastructure making it possible to support key new features
6183 including DWARF 2 Call Frame Information. To aid in the task of
6184 migrating old configurations to this new infrastructure, a
6185 compatibility module, that allowed old configurations to continue to
6186 work, was also included.
6188 GDB 6.2 will be the last release to include this frame compatibility
6189 module. This change directly impacts the following configurations:
6199 Unless there is activity to revive these configurations, they will be
6200 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6202 * REMOVED configurations and files
6204 Sun 3, running SunOS 3 m68*-*-sunos3*
6205 Sun 3, running SunOS 4 m68*-*-sunos4*
6206 Sun 2, running SunOS 3 m68000-*-sunos3*
6207 Sun 2, running SunOS 4 m68000-*-sunos4*
6208 Motorola 680x0 running LynxOS m68*-*-lynxos*
6209 AT&T 3b1/Unix pc m68*-att-*
6210 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6211 decstation mips-dec-* mips-little-*
6212 riscos mips-*-riscos* mips-*-sysv*
6213 sonymips mips-sony-*
6214 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6216 *** Changes in GDB 6.1.1:
6218 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6220 The TUI (Text-mode User Interface) is now built as part of a default
6221 GDB configuration. It is enabled by either selecting the TUI with the
6222 command line option "-i=tui" or by running the separate "gdbtui"
6223 program. For more information on the TUI, see the manual "Debugging
6226 * Pending breakpoint support (also included in GDB 6.1)
6228 Support has been added to allow you to specify breakpoints in shared
6229 libraries that have not yet been loaded. If a breakpoint location
6230 cannot be found, and the "breakpoint pending" option is set to auto,
6231 GDB queries you if you wish to make the breakpoint pending on a future
6232 shared-library load. If and when GDB resolves the breakpoint symbol,
6233 the pending breakpoint is removed as one or more regular breakpoints
6236 Pending breakpoints are very useful for GCJ Java debugging.
6238 * Fixed ISO-C build problems
6240 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6241 non ISO-C code that stopped them being built using a more strict ISO-C
6242 compiler (e.g., IBM's C compiler).
6244 * Fixed build problem on IRIX 5
6246 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6247 wasn't able to compile compile on an IRIX 5 system.
6249 * Added execute permission to gdb/gdbserver/configure
6251 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6252 permission. This bug would cause configure to fail on a number of
6253 systems (Solaris, IRIX). Ref: server/519.
6255 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6257 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6258 has been updated to use constant array sizes.
6260 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6262 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6263 its generated DWARF Call Frame Info. This encoding was causing GDB to
6264 panic, that panic has been fixed. Ref: gdb/1628.
6266 * Fixed a problem when examining parameters in shared library code.
6268 When examining parameters in optimized shared library code generated
6269 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6270 not available''. GDB now correctly displays the variable's value.
6272 *** Changes in GDB 6.1:
6274 * Removed --with-mmalloc
6276 Support for the mmalloc memory manager has been removed, as it
6277 conflicted with the internal gdb byte cache.
6279 * Changes in AMD64 configurations
6281 The AMD64 target now includes the %cs and %ss registers. As a result
6282 the AMD64 remote protocol has changed; this affects the floating-point
6283 and SSE registers. If you rely on those registers for your debugging,
6284 you should upgrade gdbserver on the remote side.
6286 * Revised SPARC target
6288 The SPARC target has been completely revised, incorporating the
6289 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6290 support for LynxOS and SunOS 4 has been dropped. Calling functions
6291 from within GDB on operating systems with a non-executable stack
6292 (Solaris, OpenBSD) now works.
6296 GDB has a new C++ demangler which does a better job on the mangled
6297 names generated by current versions of g++. It also runs faster, so
6298 with this and other changes gdb should now start faster on large C++
6301 * DWARF 2 Location Expressions
6303 GDB support for location expressions has been extended to support function
6304 arguments and frame bases. Older versions of GDB could crash when they
6307 * C++ nested types and namespaces
6309 GDB's support for nested types and namespaces in C++ has been
6310 improved, especially if you use the DWARF 2 debugging format. (This
6311 is the default for recent versions of GCC on most platforms.)
6312 Specifically, if you have a class "Inner" defined within a class or
6313 namespace "Outer", then GDB realizes that the class's name is
6314 "Outer::Inner", not simply "Inner". This should greatly reduce the
6315 frequency of complaints about not finding RTTI symbols. In addition,
6316 if you are stopped at inside of a function defined within a namespace,
6317 GDB modifies its name lookup accordingly.
6319 * New native configurations
6321 NetBSD/amd64 x86_64-*-netbsd*
6322 OpenBSD/amd64 x86_64-*-openbsd*
6323 OpenBSD/alpha alpha*-*-openbsd*
6324 OpenBSD/sparc sparc-*-openbsd*
6325 OpenBSD/sparc64 sparc64-*-openbsd*
6327 * New debugging protocols
6329 M32R with SDI protocol m32r-*-elf*
6331 * "set prompt-escape-char" command deleted.
6333 The command "set prompt-escape-char" has been deleted. This command,
6334 and its very obscure effect on GDB's prompt, was never documented,
6335 tested, nor mentioned in the NEWS file.
6337 * OBSOLETE configurations and files
6339 Configurations that have been declared obsolete in this release have
6340 been commented out. Unless there is activity to revive these
6341 configurations, the next release of GDB will have their sources
6342 permanently REMOVED.
6344 Sun 3, running SunOS 3 m68*-*-sunos3*
6345 Sun 3, running SunOS 4 m68*-*-sunos4*
6346 Sun 2, running SunOS 3 m68000-*-sunos3*
6347 Sun 2, running SunOS 4 m68000-*-sunos4*
6348 Motorola 680x0 running LynxOS m68*-*-lynxos*
6349 AT&T 3b1/Unix pc m68*-att-*
6350 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6351 decstation mips-dec-* mips-little-*
6352 riscos mips-*-riscos* mips-*-sysv*
6353 sonymips mips-sony-*
6354 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6356 * REMOVED configurations and files
6358 SGI Irix-4.x mips-sgi-irix4 or iris4
6359 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6360 Z8000 simulator z8k-zilog-none or z8ksim
6361 Matsushita MN10200 w/simulator mn10200-*-*
6362 H8/500 simulator h8500-hitachi-hms or h8500hms
6363 HP/PA running BSD hppa*-*-bsd*
6364 HP/PA running OSF/1 hppa*-*-osf*
6365 HP/PA Pro target hppa*-*-pro*
6366 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6367 386BSD i[3456]86-*-bsd*
6368 Sequent family i[3456]86-sequent-sysv4*
6369 i[3456]86-sequent-sysv*
6370 i[3456]86-sequent-bsd*
6371 SPARC running LynxOS sparc-*-lynxos*
6372 SPARC running SunOS 4 sparc-*-sunos4*
6373 Tsqware Sparclet sparclet-*-*
6374 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6376 *** Changes in GDB 6.0:
6380 Support for debugging the Objective-C programming language has been
6381 integrated into GDB.
6383 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6385 DWARF 2's Call Frame Information makes available compiler generated
6386 information that more exactly describes the program's run-time stack.
6387 By using this information, GDB is able to provide more robust stack
6390 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6391 have been updated to use a new backtrace mechanism which includes
6392 DWARF 2 CFI support.
6396 GDB's remote protocol has been extended to include support for hosted
6397 file I/O (where the remote target uses GDB's file system). See GDB's
6398 remote protocol documentation for details.
6400 * All targets using the new architecture framework.
6402 All of GDB's targets have been updated to use the new internal
6403 architecture framework. The way is now open for future GDB releases
6404 to include cross-architecture native debugging support (i386 on amd64,
6407 * GNU/Linux's Thread Local Storage (TLS)
6409 GDB now includes support for for the GNU/Linux implementation of
6410 per-thread variables.
6412 * GNU/Linux's Native POSIX Thread Library (NPTL)
6414 GDB's thread code has been updated to work with either the new
6415 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6417 * Separate debug info.
6419 GDB, in conjunction with BINUTILS, now supports a mechanism for
6420 automatically loading debug information from a separate file. Instead
6421 of shipping full debug and non-debug versions of system libraries,
6422 system integrators can now instead ship just the stripped libraries
6423 and optional debug files.
6425 * DWARF 2 Location Expressions
6427 DWARF 2 Location Expressions allow the compiler to more completely
6428 describe the location of variables (even in optimized code) to the
6431 GDB now includes preliminary support for location expressions (support
6432 for DW_OP_piece is still missing).
6436 A number of long standing bugs that caused GDB to die while starting a
6437 Java application have been fixed. GDB's Java support is now
6438 considered "useable".
6440 * GNU/Linux support for fork, vfork, and exec.
6442 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6443 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6446 * GDB supports logging output to a file
6448 There are two new commands, "set logging" and "show logging", which can be
6449 used to capture GDB's output to a file.
6451 * The meaning of "detach" has changed for gdbserver
6453 The "detach" command will now resume the application, as documented. To
6454 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6457 * d10v, m68hc11 `regs' command deprecated
6459 The `info registers' command has been updated so that it displays the
6460 registers using a format identical to the old `regs' command.
6464 A new command, "maint set profile on/off", has been added. This command can
6465 be used to enable or disable profiling while running GDB, to profile a
6466 session or a set of commands. In addition there is a new configure switch,
6467 "--enable-profiling", which will cause GDB to be compiled with profiling
6468 data, for more informative profiling results.
6470 * Default MI syntax changed to "mi2".
6472 The default MI (machine interface) syntax, enabled by the command line
6473 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6474 "mi1", can be enabled by specifying the option "-i=mi1".
6476 Support for the original "mi0" syntax (included in GDB 5.0) has been
6479 Fix for gdb/192: removed extraneous space when displaying frame level.
6480 Fix for gdb/672: update changelist is now output in mi list format.
6481 Fix for gdb/702: a -var-assign that updates the value now shows up
6482 in a subsequent -var-update.
6484 * New native configurations.
6486 FreeBSD/amd64 x86_64-*-freebsd*
6488 * Multi-arched targets.
6490 HP/PA HPUX11 hppa*-*-hpux*
6491 Renesas M32R/D w/simulator m32r-*-elf*
6493 * OBSOLETE configurations and files
6495 Configurations that have been declared obsolete in this release have
6496 been commented out. Unless there is activity to revive these
6497 configurations, the next release of GDB will have their sources
6498 permanently REMOVED.
6500 Z8000 simulator z8k-zilog-none or z8ksim
6501 Matsushita MN10200 w/simulator mn10200-*-*
6502 H8/500 simulator h8500-hitachi-hms or h8500hms
6503 HP/PA running BSD hppa*-*-bsd*
6504 HP/PA running OSF/1 hppa*-*-osf*
6505 HP/PA Pro target hppa*-*-pro*
6506 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6507 Sequent family i[3456]86-sequent-sysv4*
6508 i[3456]86-sequent-sysv*
6509 i[3456]86-sequent-bsd*
6510 Tsqware Sparclet sparclet-*-*
6511 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6513 * REMOVED configurations and files
6516 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6517 IBM AIX PS/2 i[3456]86-*-aix
6518 i386 running Mach 3.0 i[3456]86-*-mach3*
6519 i386 running Mach i[3456]86-*-mach*
6520 i386 running OSF/1 i[3456]86-*osf1mk*
6521 HP/Apollo 68k Family m68*-apollo*-sysv*,
6523 m68*-hp-bsd*, m68*-hp-hpux*
6524 Argonaut Risc Chip (ARC) arc-*-*
6525 Mitsubishi D30V d30v-*-*
6526 Fujitsu FR30 fr30-*-elf*
6527 OS/9000 i[34]86-*-os9k
6528 I960 with MON960 i960-*-coff
6530 * MIPS $fp behavior changed
6532 The convenience variable $fp, for the MIPS, now consistently returns
6533 the address of the current frame's base. Previously, depending on the
6534 context, $fp could refer to either $sp or the current frame's base
6535 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6536 The GNU Source-Level Debugger''.
6538 *** Changes in GDB 5.3:
6540 * GNU/Linux shared library multi-threaded performance improved.
6542 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6543 `/proc', in preference to `ptrace' for memory reads. This may result
6544 in an improvement in the start-up time of multi-threaded, shared
6545 library applications when run under GDB. One GDB user writes: ``loads
6546 shared libs like mad''.
6548 * ``gdbserver'' now supports multi-threaded applications on some targets
6550 Support for debugging multi-threaded applications which use
6551 the GNU/Linux LinuxThreads package has been added for
6552 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6553 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6555 * GDB now supports C/C++ preprocessor macros.
6557 GDB now expands preprocessor macro invocations in C/C++ expressions,
6558 and provides various commands for showing macro definitions and how
6561 The new command `macro expand EXPRESSION' expands any macro
6562 invocations in expression, and shows the result.
6564 The new command `show macro MACRO-NAME' shows the definition of the
6565 macro named MACRO-NAME, and where it was defined.
6567 Most compilers don't include information about macros in the debugging
6568 information by default. In GCC 3.1, for example, you need to compile
6569 your program with the options `-gdwarf-2 -g3'. If the macro
6570 information is present in the executable, GDB will read it.
6572 * Multi-arched targets.
6574 DEC Alpha (partial) alpha*-*-*
6575 DEC VAX (partial) vax-*-*
6577 National Semiconductor NS32000 (partial) ns32k-*-*
6578 Motorola 68000 (partial) m68k-*-*
6579 Motorola MCORE mcore-*-*
6583 Fujitsu FRV architecture added by Red Hat frv*-*-*
6586 * New native configurations
6588 Alpha NetBSD alpha*-*-netbsd*
6589 SH NetBSD sh*-*-netbsdelf*
6590 MIPS NetBSD mips*-*-netbsd*
6591 UltraSPARC NetBSD sparc64-*-netbsd*
6593 * OBSOLETE configurations and files
6595 Configurations that have been declared obsolete in this release have
6596 been commented out. Unless there is activity to revive these
6597 configurations, the next release of GDB will have their sources
6598 permanently REMOVED.
6600 Mitsubishi D30V d30v-*-*
6601 OS/9000 i[34]86-*-os9k
6602 IBM AIX PS/2 i[3456]86-*-aix
6603 Fujitsu FR30 fr30-*-elf*
6604 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6605 Argonaut Risc Chip (ARC) arc-*-*
6606 i386 running Mach 3.0 i[3456]86-*-mach3*
6607 i386 running Mach i[3456]86-*-mach*
6608 i386 running OSF/1 i[3456]86-*osf1mk*
6609 HP/Apollo 68k Family m68*-apollo*-sysv*,
6611 m68*-hp-bsd*, m68*-hp-hpux*
6612 I960 with MON960 i960-*-coff
6614 * OBSOLETE languages
6616 CHILL, a Pascal like language used by telecommunications companies.
6618 * REMOVED configurations and files
6620 AMD 29k family via UDI a29k-amd-udi, udi29k
6621 A29K VxWorks a29k-*-vxworks
6622 AMD 29000 embedded, using EBMON a29k-none-none
6623 AMD 29000 embedded with COFF a29k-none-coff
6624 AMD 29000 embedded with a.out a29k-none-aout
6626 testsuite/gdb.hp/gdb.threads-hp/ directory
6628 * New command "set max-user-call-depth <nnn>"
6630 This command allows the user to limit the call depth of user-defined
6631 commands. The default is 1024.
6633 * Changes in FreeBSD/i386 native debugging.
6635 Support for the "generate-core-file" has been added.
6637 * New commands "dump", "append", and "restore".
6639 These commands allow data to be copied from target memory
6640 to a bfd-format or binary file (dump and append), and back
6641 from a file into memory (restore).
6643 * Improved "next/step" support on multi-processor Alpha Tru64.
6645 The previous single-step mechanism could cause unpredictable problems,
6646 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6647 of a software single-step mechanism prevents this.
6649 *** Changes in GDB 5.2.1:
6657 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6658 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6659 Fix, by Joel Brobecker imported from mainline.
6661 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6662 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6663 Fix, by Fred Fish, imported from mainline.
6665 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6666 Surprisingly enough, it works now.
6667 By Michal Ludvig, imported from mainline.
6669 i386 hardware watchpoint support:
6670 avoid misses on second run for some targets.
6671 By Pierre Muller, imported from mainline.
6673 *** Changes in GDB 5.2:
6675 * New command "set trust-readonly-sections on[off]".
6677 This command is a hint that tells gdb that read-only sections
6678 really are read-only (ie. that their contents will not change).
6679 In this mode, gdb will go to the object file rather than the
6680 target to read memory from read-only sections (such as ".text").
6681 This can be a significant performance improvement on some
6682 (notably embedded) targets.
6684 * New command "generate-core-file" (or "gcore").
6686 This new gdb command allows the user to drop a core file of the child
6687 process state at any time. So far it's been implemented only for
6688 GNU/Linux and Solaris, but should be relatively easily ported to other
6689 hosts. Argument is core file name (defaults to core.<pid>).
6691 * New command line option
6693 GDB now accepts --pid or -p followed by a process id.
6695 * Change in command line behavior -- corefiles vs. process ids.
6697 There is a subtle behavior in the way in which GDB handles
6698 command line arguments. The first non-flag argument is always
6699 a program to debug, but the second non-flag argument may either
6700 be a corefile or a process id. Previously, GDB would attempt to
6701 open the second argument as a corefile, and if that failed, would
6702 issue a superfluous error message and then attempt to attach it as
6703 a process. Now, if the second argument begins with a non-digit,
6704 it will be treated as a corefile. If it begins with a digit,
6705 GDB will attempt to attach it as a process, and if no such process
6706 is found, will then attempt to open it as a corefile.
6708 * Changes in ARM configurations.
6710 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6711 configuration is fully multi-arch.
6713 * New native configurations
6715 ARM NetBSD arm*-*-netbsd*
6716 x86 OpenBSD i[3456]86-*-openbsd*
6717 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6718 Sparc64 running FreeBSD sparc64-*-freebsd*
6722 Sanyo XStormy16 xstormy16-elf
6724 * OBSOLETE configurations and files
6726 Configurations that have been declared obsolete in this release have
6727 been commented out. Unless there is activity to revive these
6728 configurations, the next release of GDB will have their sources
6729 permanently REMOVED.
6731 AMD 29k family via UDI a29k-amd-udi, udi29k
6732 A29K VxWorks a29k-*-vxworks
6733 AMD 29000 embedded, using EBMON a29k-none-none
6734 AMD 29000 embedded with COFF a29k-none-coff
6735 AMD 29000 embedded with a.out a29k-none-aout
6737 testsuite/gdb.hp/gdb.threads-hp/ directory
6739 * REMOVED configurations and files
6741 TI TMS320C80 tic80-*-*
6743 PowerPC Solaris powerpcle-*-solaris*
6744 PowerPC Windows NT powerpcle-*-cygwin32
6745 PowerPC Netware powerpc-*-netware*
6746 Harris/CXUX m88k m88*-harris-cxux*
6747 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6748 ns32k-utek-sysv* ns32k-utek-*
6749 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6750 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6751 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6752 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6753 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6755 * Changes to command line processing
6757 The new `--args' feature can be used to specify command-line arguments
6758 for the inferior from gdb's command line.
6760 * Changes to key bindings
6762 There is a new `operate-and-get-next' function bound to `C-o'.
6764 *** Changes in GDB 5.1.1
6766 Fix compile problem on DJGPP.
6768 Fix a problem with floating-point registers on the i386 being
6771 Fix to stop GDB crashing on .debug_str debug info.
6773 Numerous documentation fixes.
6775 Numerous testsuite fixes.
6777 *** Changes in GDB 5.1:
6779 * New native configurations
6781 Alpha FreeBSD alpha*-*-freebsd*
6782 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6783 MIPS GNU/Linux mips*-*-linux*
6784 MIPS SGI Irix 6.x mips*-sgi-irix6*
6785 ia64 AIX ia64-*-aix*
6786 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6790 Motorola 68HC11 and 68HC12 m68hc11-elf
6792 UltraSparc running GNU/Linux sparc64-*-linux*
6794 * OBSOLETE configurations and files
6796 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6797 Harris/CXUX m88k m88*-harris-cxux*
6798 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6799 ns32k-utek-sysv* ns32k-utek-*
6800 TI TMS320C80 tic80-*-*
6802 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6803 PowerPC Solaris powerpcle-*-solaris*
6804 PowerPC Windows NT powerpcle-*-cygwin32
6805 PowerPC Netware powerpc-*-netware*
6806 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6807 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6808 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6809 Apple Macintosh (MPW) host N/A
6811 stuff.c (Program to stuff files into a specially prepared space in kdb)
6812 kdb-start.c (Main loop for the standalone kernel debugger)
6814 Configurations that have been declared obsolete in this release have
6815 been commented out. Unless there is activity to revive these
6816 configurations, the next release of GDB will have their sources
6817 permanently REMOVED.
6819 * REMOVED configurations and files
6821 Altos 3068 m68*-altos-*
6822 Convex c1-*-*, c2-*-*
6824 ARM RISCix arm-*-* (as host)
6828 * GDB has been converted to ISO C.
6830 GDB's source code has been converted to ISO C. In particular, the
6831 sources are fully protoized, and rely on standard headers being
6836 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6838 * The MI enabled by default.
6840 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6841 revised and enabled by default. Packages which use GDB as a debugging
6842 engine behind a UI or another front end are encouraged to switch to
6843 using the GDB/MI interface, instead of the old annotations interface
6844 which is now deprecated.
6846 * Support for debugging Pascal programs.
6848 GDB now includes support for debugging Pascal programs. The following
6849 main features are supported:
6851 - Pascal-specific data types such as sets;
6853 - automatic recognition of Pascal sources based on file-name
6856 - Pascal-style display of data types, variables, and functions;
6858 - a Pascal expression parser.
6860 However, some important features are not yet supported.
6862 - Pascal string operations are not supported at all;
6864 - there are some problems with boolean types;
6866 - Pascal type hexadecimal constants are not supported
6867 because they conflict with the internal variables format;
6869 - support for Pascal objects and classes is not full yet;
6871 - unlike Pascal, GDB is case-sensitive for symbol names.
6873 * Changes in completion.
6875 Commands such as `shell', `run' and `set args', which pass arguments
6876 to inferior programs, now complete on file names, similar to what
6877 users expect at the shell prompt.
6879 Commands which accept locations, such as `disassemble', `print',
6880 `breakpoint', `until', etc. now complete on filenames as well as
6881 program symbols. Thus, if you type "break foob TAB", and the source
6882 files linked into the programs include `foobar.c', that file name will
6883 be one of the candidates for completion. However, file names are not
6884 considered for completion after you typed a colon that delimits a file
6885 name from a name of a function in that file, as in "break foo.c:bar".
6887 `set demangle-style' completes on available demangling styles.
6889 * New platform-independent commands:
6891 It is now possible to define a post-hook for a command as well as a
6892 hook that runs before the command. For more details, see the
6893 documentation of `hookpost' in the GDB manual.
6895 * Changes in GNU/Linux native debugging.
6897 Support for debugging multi-threaded programs has been completely
6898 revised for all platforms except m68k and sparc. You can now debug as
6899 many threads as your system allows you to have.
6901 Attach/detach is supported for multi-threaded programs.
6903 Support for SSE registers was added for x86. This doesn't work for
6904 multi-threaded programs though.
6906 * Changes in MIPS configurations.
6908 Multi-arch support is enabled for all MIPS configurations.
6910 GDB can now be built as native debugger on SGI Irix 6.x systems for
6911 debugging n32 executables. (Debugging 64-bit executables is not yet
6914 * Unified support for hardware watchpoints in all x86 configurations.
6916 Most (if not all) native x86 configurations support hardware-assisted
6917 breakpoints and watchpoints in a unified manner. This support
6918 implements debug register sharing between watchpoints, which allows to
6919 put a virtually infinite number of watchpoints on the same address,
6920 and also supports watching regions up to 16 bytes with several debug
6923 The new maintenance command `maintenance show-debug-regs' toggles
6924 debugging print-outs in functions that insert, remove, and test
6925 watchpoints and hardware breakpoints.
6927 * Changes in the DJGPP native configuration.
6929 New command ``info dos sysinfo'' displays assorted information about
6930 the CPU, OS, memory, and DPMI server.
6932 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6933 display information about segment descriptors stored in GDT, LDT, and
6936 New commands ``info dos pde'' and ``info dos pte'' display entries
6937 from Page Directory and Page Tables (for now works with CWSDPMI only).
6938 New command ``info dos address-pte'' displays the Page Table entry for
6939 a given linear address.
6941 GDB can now pass command lines longer than 126 characters to the
6942 program being debugged (requires an update to the libdbg.a library
6943 which is part of the DJGPP development kit).
6945 DWARF2 debug info is now supported.
6947 It is now possible to `step' and `next' through calls to `longjmp'.
6949 * Changes in documentation.
6951 All GDB documentation was converted to GFDL, the GNU Free
6952 Documentation License.
6954 Tracepoints-related commands are now fully documented in the GDB
6957 TUI, the Text-mode User Interface, is now documented in the manual.
6959 Tracepoints-related commands are now fully documented in the GDB
6962 The "GDB Internals" manual now has an index. It also includes
6963 documentation of `ui_out' functions, GDB coding standards, x86
6964 hardware watchpoints, and memory region attributes.
6966 * GDB's version number moved to ``version.in''
6968 The Makefile variable VERSION has been replaced by the file
6969 ``version.in''. People creating GDB distributions should update the
6970 contents of this file.
6974 GUD support is now a standard part of the EMACS distribution.
6976 *** Changes in GDB 5.0:
6978 * Improved support for debugging FP programs on x86 targets
6980 Unified and much-improved support for debugging floating-point
6981 programs on all x86 targets. In particular, ``info float'' now
6982 displays the FP registers in the same format on all x86 targets, with
6983 greater level of detail.
6985 * Improvements and bugfixes in hardware-assisted watchpoints
6987 It is now possible to watch array elements, struct members, and
6988 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6989 on x86 targets no longer erroneously trigger when the address is
6992 * Improvements in the native DJGPP version of GDB
6994 The distribution now includes all the scripts and auxiliary files
6995 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6996 machines ``out of the box''.
6998 The DJGPP version can now debug programs that use signals. It is
6999 possible to catch signals that happened in the debuggee, deliver
7000 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7001 would kill the program being debugged.) Programs that hook hardware
7002 interrupts (keyboard, timer, etc.) can also be debugged.
7004 It is now possible to debug DJGPP programs that redirect their
7005 standard handles or switch them to raw (as opposed to cooked) mode, or
7006 even close them. The command ``run < foo > bar'' works as expected,
7007 and ``info terminal'' reports useful information about the debuggee's
7008 terminal, including raw/cooked mode, redirection, etc.
7010 The DJGPP version now uses termios functions for console I/O, which
7011 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7014 DOS-style file names with drive letters are now fully supported by
7017 It is now possible to debug DJGPP programs that switch their working
7018 directory. It is also possible to rerun the debuggee any number of
7019 times without restarting GDB; thus, you can use the same setup,
7020 breakpoints, etc. for many debugging sessions.
7022 * New native configurations
7024 ARM GNU/Linux arm*-*-linux*
7025 PowerPC GNU/Linux powerpc-*-linux*
7029 Motorola MCore mcore-*-*
7030 x86 VxWorks i[3456]86-*-vxworks*
7031 PowerPC VxWorks powerpc-*-vxworks*
7032 TI TMS320C80 tic80-*-*
7034 * OBSOLETE configurations
7036 Altos 3068 m68*-altos-*
7037 Convex c1-*-*, c2-*-*
7039 ARM RISCix arm-*-* (as host)
7042 Configurations that have been declared obsolete will be commented out,
7043 but the code will be left in place. If there is no activity to revive
7044 these configurations before the next release of GDB, the sources will
7045 be permanently REMOVED.
7047 * Gould support removed
7049 Support for the Gould PowerNode and NP1 has been removed.
7051 * New features for SVR4
7053 On SVR4 native platforms (such as Solaris), if you attach to a process
7054 without first loading a symbol file, GDB will now attempt to locate and
7055 load symbols from the running process's executable file.
7057 * Many C++ enhancements
7059 C++ support has been greatly improved. Overload resolution now works properly
7060 in almost all cases. RTTI support is on the way.
7062 * Remote targets can connect to a sub-program
7064 A popen(3) style serial-device has been added. This device starts a
7065 sub-process (such as a stand-alone simulator) and then communicates
7066 with that. The sub-program to run is specified using the syntax
7067 ``|<program> <args>'' vis:
7069 (gdb) set remotedebug 1
7070 (gdb) target extended-remote |mn10300-elf-sim program-args
7072 * MIPS 64 remote protocol
7074 A long standing bug in the mips64 remote protocol where by GDB
7075 expected certain 32 bit registers (ex SR) to be transfered as 32
7076 instead of 64 bits has been fixed.
7078 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7079 added to provide backward compatibility with older versions of GDB.
7081 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7083 The command ``set remotebinarydownload'' command has been replaced by
7084 ``set remote X-packet''. Other commands in ``set remote'' family
7085 include ``set remote P-packet''.
7087 * Breakpoint commands accept ranges.
7089 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7090 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7091 ``tracepoint passcount'' also accepts a range of tracepoints.
7093 * ``apropos'' command added.
7095 The ``apropos'' command searches through command names and
7096 documentation strings, printing out matches, making it much easier to
7097 try to find a command that does what you are looking for.
7101 A new machine oriented interface (MI) has been added to GDB. This
7102 interface is designed for debug environments running GDB as a separate
7103 process. This is part of the long term libGDB project. See the
7104 "GDB/MI" chapter of the GDB manual for further information. It can be
7105 enabled by configuring with:
7107 .../configure --enable-gdbmi
7109 *** Changes in GDB-4.18:
7111 * New native configurations
7113 HP-UX 10.20 hppa*-*-hpux10.20
7114 HP-UX 11.x hppa*-*-hpux11.0*
7115 M68K GNU/Linux m68*-*-linux*
7119 Fujitsu FR30 fr30-*-elf*
7120 Intel StrongARM strongarm-*-*
7121 Mitsubishi D30V d30v-*-*
7123 * OBSOLETE configurations
7125 Gould PowerNode, NP1 np1-*-*, pn-*-*
7127 Configurations that have been declared obsolete will be commented out,
7128 but the code will be left in place. If there is no activity to revive
7129 these configurations before the next release of GDB, the sources will
7130 be permanently REMOVED.
7134 As a compatibility experiment, GDB's source files buildsym.h and
7135 buildsym.c have been converted to pure standard C, no longer
7136 containing any K&R compatibility code. We believe that all systems in
7137 use today either come with a standard C compiler, or have a GCC port
7138 available. If this is not true, please report the affected
7139 configuration to bug-gdb@gnu.org immediately. See the README file for
7140 information about getting a standard C compiler if you don't have one
7145 GDB now uses readline 2.2.
7147 * set extension-language
7149 You can now control the mapping between filename extensions and source
7150 languages by using the `set extension-language' command. For instance,
7151 you can ask GDB to treat .c files as C++ by saying
7152 set extension-language .c c++
7153 The command `info extensions' lists all of the recognized extensions
7154 and their associated languages.
7156 * Setting processor type for PowerPC and RS/6000
7158 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7159 you can use the `set processor' command to specify what variant of the
7160 PowerPC family you are debugging. The command
7164 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7165 following PowerPC and RS6000 variants:
7167 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7168 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7170 403GC IBM PowerPC 403GC
7171 505 Motorola PowerPC 505
7172 860 Motorola PowerPC 860 or 850
7173 601 Motorola PowerPC 601
7174 602 Motorola PowerPC 602
7175 603 Motorola/IBM PowerPC 603 or 603e
7176 604 Motorola PowerPC 604 or 604e
7177 750 Motorola/IBM PowerPC 750 or 750
7179 At the moment, this command just tells GDB what to name the
7180 special-purpose processor registers. Since almost all the affected
7181 registers are inaccessible to user-level programs, this command is
7182 only useful for remote debugging in its present form.
7186 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7187 more extensive support for HP-UX. Added features include shared
7188 library support, kernel threads and hardware watchpoints for 11.00,
7189 support for HP's ANSI C and C++ compilers, and a compatibility mode
7190 for xdb and dbx commands.
7194 HP's donation includes the new concept of catchpoints, which is a
7195 generalization of the old catch command. On HP-UX, it is now possible
7196 to catch exec, fork, and vfork, as well as library loading.
7198 This means that the existing catch command has changed; its first
7199 argument now specifies the type of catch to be set up. See the
7200 output of "help catch" for a list of catchpoint types.
7202 * Debugging across forks
7204 On HP-UX, you can choose which process to debug when a fork() happens
7209 HP has donated a curses-based terminal user interface (TUI). To get
7210 it, build with --enable-tui. Although this can be enabled for any
7211 configuration, at present it only works for native HP debugging.
7213 * GDB remote protocol additions
7215 A new protocol packet 'X' that writes binary data is now available.
7216 Default behavior is to try 'X', then drop back to 'M' if the stub
7217 fails to respond. The settable variable `remotebinarydownload'
7218 allows explicit control over the use of 'X'.
7220 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7221 full 64-bit address. The command
7223 set remoteaddresssize 32
7225 can be used to revert to the old behaviour. For existing remote stubs
7226 the change should not be noticed, as the additional address information
7229 In order to assist in debugging stubs, you may use the maintenance
7230 command `packet' to send any text string to the stub. For instance,
7232 maint packet heythere
7234 sends the packet "$heythere#<checksum>". Note that it is very easy to
7235 disrupt a debugging session by sending the wrong packet at the wrong
7238 The compare-sections command allows you to compare section data on the
7239 target to what is in the executable file without uploading or
7240 downloading, by comparing CRC checksums.
7242 * Tracing can collect general expressions
7244 You may now collect general expressions at tracepoints. This requires
7245 further additions to the target-side stub; see tracepoint.c and
7246 doc/agentexpr.texi for further details.
7248 * mask-address variable for Mips
7250 For Mips targets, you may control the zeroing of the upper 32 bits of
7251 a 64-bit address by entering `set mask-address on'. This is mainly
7252 of interest to users of embedded R4xxx and R5xxx processors.
7254 * Higher serial baud rates
7256 GDB's serial code now allows you to specify baud rates 57600, 115200,
7257 230400, and 460800 baud. (Note that your host system may not be able
7258 to achieve all of these rates.)
7262 The i960 configuration now includes an initial implementation of a
7263 builtin simulator, contributed by Jim Wilson.
7266 *** Changes in GDB-4.17:
7268 * New native configurations
7270 Alpha GNU/Linux alpha*-*-linux*
7271 Unixware 2.x i[3456]86-unixware2*
7272 Irix 6.x mips*-sgi-irix6*
7273 PowerPC GNU/Linux powerpc-*-linux*
7274 PowerPC Solaris powerpcle-*-solaris*
7275 Sparc GNU/Linux sparc-*-linux*
7276 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7280 Argonaut Risc Chip (ARC) arc-*-*
7281 Hitachi H8/300S h8300*-*-*
7282 Matsushita MN10200 w/simulator mn10200-*-*
7283 Matsushita MN10300 w/simulator mn10300-*-*
7284 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7285 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7286 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7287 Mitsubishi D10V w/simulator d10v-*-*
7288 Mitsubishi M32R/D w/simulator m32r-*-elf*
7289 Tsqware Sparclet sparclet-*-*
7290 NEC V850 w/simulator v850-*-*
7292 * New debugging protocols
7294 ARM with RDI protocol arm*-*-*
7295 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7296 DDB and LSI variants of PMON protocol mips*-*-*
7297 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7298 PowerPC with SDS protocol powerpc{,le}-*-eabi
7299 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7303 All configurations can now understand and use the DWARF 2 debugging
7304 format. The choice is automatic, if the symbol file contains DWARF 2
7309 GDB now includes basic Java language support. This support is
7310 only useful with Java compilers that produce native machine code.
7312 * solib-absolute-prefix and solib-search-path
7314 For SunOS and SVR4 shared libraries, you may now set the prefix for
7315 loading absolute shared library symbol files, and the search path for
7316 locating non-absolute shared library symbol files.
7318 * Live range splitting
7320 GDB can now effectively debug code for which GCC has performed live
7321 range splitting as part of its optimization. See gdb/doc/LRS for
7322 more details on the expected format of the stabs information.
7326 GDB's support for the GNU Hurd, including thread debugging, has been
7327 updated to work with current versions of the Hurd.
7331 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7332 instruction set. ARM GDB automatically detects when Thumb
7333 instructions are in use, and adjusts disassembly and backtracing
7338 GDB's MIPS target configurations now handle the MIP16 16-bit
7343 GDB now includes support for overlays; if an executable has been
7344 linked such that multiple sections are based at the same address, GDB
7345 will decide which section to use for symbolic info. You can choose to
7346 control the decision manually, using overlay commands, or implement
7347 additional target-side support and use "overlay load-target" to bring
7348 in the overlay mapping. Do "help overlay" for more detail.
7352 The command "info symbol <address>" displays information about
7353 the symbol at the specified address.
7357 The standard remote protocol now includes an extension that allows
7358 asynchronous collection and display of trace data. This requires
7359 extensive support in the target-side debugging stub. Tracing mode
7360 includes a new interaction mode in GDB and new commands: see the
7361 file tracepoint.c for more details.
7365 Configurations for embedded MIPS now include a simulator contributed
7366 by Cygnus Solutions. The simulator supports the instruction sets
7367 of most MIPS variants.
7371 Sparc configurations may now include the ERC32 simulator contributed
7372 by the European Space Agency. The simulator is not built into
7373 Sparc targets by default; configure with --enable-sim to include it.
7377 For target configurations that may include multiple variants of a
7378 basic architecture (such as MIPS and SH), you may now set the
7379 architecture explicitly. "set arch" sets, "info arch" lists
7380 the possible architectures.
7382 *** Changes in GDB-4.16:
7384 * New native configurations
7386 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7387 M68K NetBSD m68k-*-netbsd*
7388 PowerPC AIX 4.x powerpc-*-aix*
7389 PowerPC MacOS powerpc-*-macos*
7390 PowerPC Windows NT powerpcle-*-cygwin32
7391 RS/6000 AIX 4.x rs6000-*-aix4*
7395 ARM with RDP protocol arm-*-*
7396 I960 with MON960 i960-*-coff
7397 MIPS VxWorks mips*-*-vxworks*
7398 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7399 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7401 Matra Sparclet sparclet-*-*
7405 The powerpc-eabi configuration now includes the PSIM simulator,
7406 contributed by Andrew Cagney, with assistance from Mike Meissner.
7407 PSIM is a very elaborate model of the PowerPC, including not only
7408 basic instruction set execution, but also details of execution unit
7409 performance and I/O hardware. See sim/ppc/README for more details.
7413 GDB now works with Solaris 2.5.
7415 * Windows 95/NT native
7417 GDB will now work as a native debugger on Windows 95 and Windows NT.
7418 To build it from source, you must use the "gnu-win32" environment,
7419 which uses a DLL to emulate enough of Unix to run the GNU tools.
7420 Further information, binaries, and sources are available at
7421 ftp.cygnus.com, under pub/gnu-win32.
7423 * dont-repeat command
7425 If a user-defined command includes the command `dont-repeat', then the
7426 command will not be repeated if the user just types return. This is
7427 useful if the command is time-consuming to run, so that accidental
7428 extra keystrokes don't run the same command many times.
7430 * Send break instead of ^C
7432 The standard remote protocol now includes an option to send a break
7433 rather than a ^C to the target in order to interrupt it. By default,
7434 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7436 * Remote protocol timeout
7438 The standard remote protocol includes a new variable `remotetimeout'
7439 that allows you to set the number of seconds before GDB gives up trying
7440 to read from the target. The default value is 2.
7442 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7444 By default GDB will automatically keep track of objects as they are
7445 loaded and unloaded by the dynamic linker. By using the command `set
7446 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7447 when shared library events occur, thus allowing you to set breakpoints
7448 in shared libraries which are explicitly loaded by the inferior.
7450 Note this feature does not work on hpux8. On hpux9 you must link
7451 /usr/lib/end.o into your program. This feature should work
7452 automatically on hpux10.
7454 * Irix 5.x hardware watchpoint support
7456 Irix 5 configurations now support the use of hardware watchpoints.
7458 * Mips protocol "SYN garbage limit"
7460 When debugging a Mips target using the `target mips' protocol, you
7461 may set the number of characters that GDB will ignore by setting
7462 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7463 every character. The default value is 1050.
7465 * Recording and replaying remote debug sessions
7467 If you set `remotelogfile' to the name of a file, gdb will write to it
7468 a recording of a remote debug session. This recording may then be
7469 replayed back to gdb using "gdbreplay". See gdbserver/README for
7470 details. This is useful when you have a problem with GDB while doing
7471 remote debugging; you can make a recording of the session and send it
7472 to someone else, who can then recreate the problem.
7474 * Speedups for remote debugging
7476 GDB includes speedups for downloading and stepping MIPS systems using
7477 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7478 and more efficient S-record downloading.
7480 * Memory use reductions and statistics collection
7482 GDB now uses less memory and reports statistics about memory usage.
7483 Try the `maint print statistics' command, for example.
7485 *** Changes in GDB-4.15:
7487 * Psymtabs for XCOFF
7489 The symbol reader for AIX GDB now uses partial symbol tables. This
7490 can greatly improve startup time, especially for large executables.
7492 * Remote targets use caching
7494 Remote targets now use a data cache to speed up communication with the
7495 remote side. The data cache could lead to incorrect results because
7496 it doesn't know about volatile variables, thus making it impossible to
7497 debug targets which use memory mapped I/O devices. `set remotecache
7498 off' turns the data cache off.
7500 * Remote targets may have threads
7502 The standard remote protocol now includes support for multiple threads
7503 in the target system, using new protocol commands 'H' and 'T'. See
7504 gdb/remote.c for details.
7508 If GDB is configured with `--enable-netrom', then it will include
7509 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7510 acts as though it is a bank of ROM on the target board, but you can
7511 write into it over the network. GDB's support consists only of
7512 support for fast loading into the emulated ROM; to debug, you must use
7513 another protocol, such as standard remote protocol. The usual
7514 sequence is something like
7516 target nrom <netrom-hostname>
7518 target remote <netrom-hostname>:1235
7522 GDB now includes support for the Apple Macintosh, as a host only. It
7523 may be run as either an MPW tool or as a standalone application, and
7524 it can debug through the serial port. All the usual GDB commands are
7525 available, but to the target command, you must supply "serial" as the
7526 device type instead of "/dev/ttyXX". See mpw-README in the main
7527 directory for more information on how to build. The MPW configuration
7528 scripts */mpw-config.in support only a few targets, and only the
7529 mips-idt-ecoff target has been tested.
7533 GDB configuration now uses autoconf. This is not user-visible,
7534 but does simplify configuration and building.
7538 GDB now supports hpux10.
7540 *** Changes in GDB-4.14:
7542 * New native configurations
7544 x86 FreeBSD i[345]86-*-freebsd
7545 x86 NetBSD i[345]86-*-netbsd
7546 NS32k NetBSD ns32k-*-netbsd
7547 Sparc NetBSD sparc-*-netbsd
7551 A29K VxWorks a29k-*-vxworks
7552 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7553 CPU32 EST-300 emulator m68*-*-est*
7554 PowerPC ELF powerpc-*-elf
7557 * Alpha OSF/1 support for procfs
7559 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7560 possible to attach to running processes. As the mounting of the /proc
7561 filesystem is optional on the Alpha, GDB automatically determines
7562 the availability of /proc during startup. This can lead to problems
7563 if /proc is unmounted after GDB has been started.
7565 * Arguments to user-defined commands
7567 User commands may accept up to 10 arguments separated by whitespace.
7568 Arguments are accessed within the user command via $arg0..$arg9. A
7571 print $arg0 + $arg1 + $arg2
7573 To execute the command use:
7576 Defines the command "adder" which prints the sum of its three arguments.
7577 Note the arguments are text substitutions, so they may reference variables,
7578 use complex expressions, or even perform inferior function calls.
7580 * New `if' and `while' commands
7582 This makes it possible to write more sophisticated user-defined
7583 commands. Both commands take a single argument, which is the
7584 expression to evaluate, and must be followed by the commands to
7585 execute, one per line, if the expression is nonzero, the list being
7586 terminated by the word `end'. The `if' command list may include an
7587 `else' word, which causes the following commands to be executed only
7588 if the expression is zero.
7590 * Fortran source language mode
7592 GDB now includes partial support for Fortran 77. It will recognize
7593 Fortran programs and can evaluate a subset of Fortran expressions, but
7594 variables and functions may not be handled correctly. GDB will work
7595 with G77, but does not yet know much about symbols emitted by other
7598 * Better HPUX support
7600 Most debugging facilities now work on dynamic executables for HPPAs
7601 running hpux9 or later. You can attach to running dynamically linked
7602 processes, but by default the dynamic libraries will be read-only, so
7603 for instance you won't be able to put breakpoints in them. To change
7604 that behavior do the following before running the program:
7610 This will cause the libraries to be mapped private and read-write.
7611 To revert to the normal behavior, do this:
7617 You cannot set breakpoints or examine data in the library until after
7618 the library is loaded if the function/data symbols do not have
7621 GDB can now also read debug symbols produced by the HP C compiler on
7622 HPPAs (sorry, no C++, Fortran or 68k support).
7624 * Target byte order now dynamically selectable
7626 You can choose which byte order to use with a target system, via the
7627 commands "set endian big" and "set endian little", and you can see the
7628 current setting by using "show endian". You can also give the command
7629 "set endian auto", in which case GDB will use the byte order
7630 associated with the executable. Currently, only embedded MIPS
7631 configurations support dynamic selection of target byte order.
7633 * New DOS host serial code
7635 This version uses DPMI interrupts to handle buffered I/O, so you
7636 no longer need to run asynctsr when debugging boards connected to
7639 *** Changes in GDB-4.13:
7641 * New "complete" command
7643 This lists all the possible completions for the rest of the line, if it
7644 were to be given as a command itself. This is intended for use by emacs.
7646 * Trailing space optional in prompt
7648 "set prompt" no longer adds a space for you after the prompt you set. This
7649 allows you to set a prompt which ends in a space or one that does not.
7651 * Breakpoint hit counts
7653 "info break" now displays a count of the number of times the breakpoint
7654 has been hit. This is especially useful in conjunction with "ignore"; you
7655 can ignore a large number of breakpoint hits, look at the breakpoint info
7656 to see how many times the breakpoint was hit, then run again, ignoring one
7657 less than that number, and this will get you quickly to the last hit of
7660 * Ability to stop printing at NULL character
7662 "set print null-stop" will cause GDB to stop printing the characters of
7663 an array when the first NULL is encountered. This is useful when large
7664 arrays actually contain only short strings.
7666 * Shared library breakpoints
7668 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7669 breakpoints in shared libraries before the executable is run.
7671 * Hardware watchpoints
7673 There is a new hardware breakpoint for the watch command for sparclite
7674 targets. See gdb/sparclite/hw_breakpoint.note.
7676 Hardware watchpoints are also now supported under GNU/Linux.
7680 Annotations have been added. These are for use with graphical interfaces,
7681 and are still experimental. Currently only gdba.el uses these.
7683 * Improved Irix 5 support
7685 GDB now works properly with Irix 5.2.
7687 * Improved HPPA support
7689 GDB now works properly with the latest GCC and GAS.
7691 * New native configurations
7693 Sequent PTX4 i[34]86-sequent-ptx4
7694 HPPA running OSF/1 hppa*-*-osf*
7695 Atari TT running SVR4 m68*-*-sysv4*
7696 RS/6000 LynxOS rs6000-*-lynxos*
7700 OS/9000 i[34]86-*-os9k
7701 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7704 * Hitachi SH7000 and E7000-PC ICE support
7706 There is now support for communicating with the Hitachi E7000-PC ICE.
7707 This is available automatically when GDB is configured for the SH.
7711 As usual, a variety of small fixes and improvements, both generic
7712 and configuration-specific. See the ChangeLog for more detail.
7714 *** Changes in GDB-4.12:
7716 * Irix 5 is now supported
7720 GDB-4.12 on the HPPA has a number of changes which make it unable
7721 to debug the output from the currently released versions of GCC and
7722 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7723 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7724 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7727 *** Changes in GDB-4.11:
7729 * User visible changes:
7733 The "set remotedebug" option is now consistent between the mips remote
7734 target, remote targets using the gdb-specific protocol, UDI (AMD's
7735 debug protocol for the 29k) and the 88k bug monitor. It is now an
7736 integer specifying a debug level (normally 0 or 1, but 2 means more
7737 debugging info for the mips target).
7739 * DEC Alpha native support
7741 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7742 debug info, but GDB works fairly well with the DEC compiler and should
7743 work with a future GCC release. See the README file for a few
7744 Alpha-specific notes.
7746 * Preliminary thread implementation
7748 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7750 * LynxOS native and target support for 386
7752 This release has been hosted on LynxOS 2.2, and also can be configured
7753 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7756 * Improvements in C++ mangling/demangling.
7758 This release has much better g++ debugging, specifically in name
7759 mangling/demangling, virtual function calls, print virtual table,
7760 call methods, ...etc.
7762 *** Changes in GDB-4.10:
7764 * User visible changes:
7766 Remote debugging using the GDB-specific (`target remote') protocol now
7767 supports the `load' command. This is only useful if you have some
7768 other way of getting the stub to the target system, and you can put it
7769 somewhere in memory where it won't get clobbered by the download.
7771 Filename completion now works.
7773 When run under emacs mode, the "info line" command now causes the
7774 arrow to point to the line specified. Also, "info line" prints
7775 addresses in symbolic form (as well as hex).
7777 All vxworks based targets now support a user settable option, called
7778 vxworks-timeout. This option represents the number of seconds gdb
7779 should wait for responses to rpc's. You might want to use this if
7780 your vxworks target is, perhaps, a slow software simulator or happens
7781 to be on the far side of a thin network line.
7785 This release contains support for using a DEC alpha as a GDB host for
7786 cross debugging. Native alpha debugging is not supported yet.
7789 *** Changes in GDB-4.9:
7793 This is the first GDB release which is accompanied by a matching testsuite.
7794 The testsuite requires installation of dejagnu, which should be available
7795 via ftp from most sites that carry GNU software.
7799 'Cfront' style demangling has had its name changed to 'ARM' style, to
7800 emphasize that it was written from the specifications in the C++ Annotated
7801 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7802 disclaimers, it still generated too much confusion with users attempting to
7803 use gdb with AT&T cfront.
7807 GDB now uses a standard remote interface to a simulator library.
7808 So far, the library contains simulators for the Zilog Z8001/2, the
7809 Hitachi H8/300, H8/500 and Super-H.
7811 * New targets supported
7813 H8/300 simulator h8300-hitachi-hms or h8300hms
7814 H8/500 simulator h8500-hitachi-hms or h8500hms
7815 SH simulator sh-hitachi-hms or sh
7816 Z8000 simulator z8k-zilog-none or z8ksim
7817 IDT MIPS board over serial line mips-idt-ecoff
7819 Cross-debugging to GO32 targets is supported. It requires a custom
7820 version of the i386-stub.c module which is integrated with the
7821 GO32 memory extender.
7823 * New remote protocols
7825 MIPS remote debugging protocol.
7827 * New source languages supported
7829 This version includes preliminary support for Chill, a Pascal like language
7830 used by telecommunications companies. Chill support is also being integrated
7831 into the GNU compiler, but we don't know when it will be publically available.
7834 *** Changes in GDB-4.8:
7836 * HP Precision Architecture supported
7838 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7839 version of this support was available as a set of patches from the
7840 University of Utah. GDB does not support debugging of programs
7841 compiled with the HP compiler, because HP will not document their file
7842 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7843 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7845 Many problems in the preliminary version have been fixed.
7847 * Faster and better demangling
7849 We have improved template demangling and fixed numerous bugs in the GNU style
7850 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7851 character types (wchar_t) are now supported. Demangling of each symbol is now
7852 only done once, and is cached when the symbol table for a file is read in.
7853 This results in a small increase in memory usage for C programs, a moderate
7854 increase in memory usage for C++ programs, and a fantastic speedup in
7857 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7858 from the specifications in the Annotated Reference Manual, which AT&T's
7859 compiler does not actually implement.
7861 * G++ multiple inheritance compiler problem
7863 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7864 inheritance lattices was reworked to properly discover ambiguities. We
7865 recently found an example which causes this new algorithm to fail in a
7866 very subtle way, producing bad debug information for those classes.
7867 The file 'gcc.patch' (in this directory) can be applied to gcc to
7868 circumvent the problem. A future GCC release will contain a complete
7871 The previous G++ debug info problem (mentioned below for the gdb-4.7
7872 release) is fixed in gcc version 2.3.2.
7874 * Improved configure script
7876 The `configure' script will now attempt to guess your system type if
7877 you don't supply a host system type. The old scheme of supplying a
7878 host system triplet is preferable over using this. All the magic is
7879 done in the new `config.guess' script. Examine it for details.
7881 We have also brought our configure script much more in line with the FSF's
7882 version. It now supports the --with-xxx options. In particular,
7883 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7884 The resulting GDB will not be able to read arbitrary object file formats --
7885 only the format ``expected'' to be used on the configured target system.
7886 We hope to make this the default in a future release.
7888 * Documentation improvements
7890 There's new internal documentation on how to modify GDB, and how to
7891 produce clean changes to the code. We implore people to read it
7892 before submitting changes.
7894 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7895 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7896 `info' files are also provided. To build `info' files from scratch,
7897 you will need the latest `makeinfo' release, which will be available in
7898 a future texinfo-X.Y release.
7900 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7901 We're not sure exactly which versions have this problem, but it has
7902 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7903 or better. If that isn't possible, there is a patch in
7904 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7905 around this problem.
7909 GDB now supports array constants that can be used in expressions typed in by
7910 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7911 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7914 The new directory `gdb/sparclite' contains a program that demonstrates
7915 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7917 * New native hosts supported
7919 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7920 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7922 * New targets supported
7924 AMD 29k family via UDI a29k-amd-udi or udi29k
7926 * New file formats supported
7928 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7929 HPUX core files, and SCO 3.2v2 core files.
7933 Attaching to processes now works again; thanks for the many bug reports.
7935 We have also stomped on a bunch of core dumps caused by
7936 printf_filtered("%s") problems.
7938 We eliminated a copyright problem on the rpc and ptrace header files
7939 for VxWorks, which was discovered at the last minute during the 4.7
7940 release. You should now be able to build a VxWorks GDB.
7942 You can now interrupt gdb while an attached process is running. This
7943 will cause the attached process to stop, and give control back to GDB.
7945 We fixed problems caused by using too many file descriptors
7946 for reading symbols from object files and libraries. This was
7947 especially a problem for programs that used many (~100) shared
7950 The `step' command now only enters a subroutine if there is line number
7951 information for the subroutine. Otherwise it acts like the `next'
7952 command. Previously, `step' would enter subroutines if there was
7953 any debugging information about the routine. This avoids problems
7954 when using `cc -g1' on MIPS machines.
7956 * Internal improvements
7958 GDB's internal interfaces have been improved to make it easier to support
7959 debugging of multiple languages in the future.
7961 GDB now uses a common structure for symbol information internally.
7962 Minimal symbols (derived from linkage symbols in object files), partial
7963 symbols (from a quick scan of debug information), and full symbols
7964 contain a common subset of information, making it easier to write
7965 shared code that handles any of them.
7967 * New command line options
7969 We now accept --silent as an alias for --quiet.
7973 The memory-mapped-malloc library is now licensed under the GNU Library
7974 General Public License.
7976 *** Changes in GDB-4.7:
7978 * Host/native/target split
7980 GDB has had some major internal surgery to untangle the support for
7981 hosts and remote targets. Now, when you configure GDB for a remote
7982 target, it will no longer load in all of the support for debugging
7983 local programs on the host. When fully completed and tested, this will
7984 ensure that arbitrary host/target combinations are possible.
7986 The primary conceptual shift is to separate the non-portable code in
7987 GDB into three categories. Host specific code is required any time GDB
7988 is compiled on that host, regardless of the target. Target specific
7989 code relates to the peculiarities of the target, but can be compiled on
7990 any host. Native specific code is everything else: it can only be
7991 built when the host and target are the same system. Child process
7992 handling and core file support are two common `native' examples.
7994 GDB's use of /proc for controlling Unix child processes is now cleaner.
7995 It has been split out into a single module under the `target_ops' vector,
7996 plus two native-dependent functions for each system that uses /proc.
7998 * New hosts supported
8000 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8001 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8002 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8004 * New targets supported
8006 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8007 68030 and CPU32 m68030-*-*, m68332-*-*
8009 * New native hosts supported
8011 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8012 (386bsd is not well tested yet)
8013 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8015 * New file formats supported
8017 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8018 supports reading of `a.out.adobe' object files, which are an a.out
8019 format extended with minimal information about multiple sections.
8023 `show copying' is the same as the old `info copying'.
8024 `show warranty' is the same as `info warrantee'.
8025 These were renamed for consistency. The old commands continue to work.
8027 `info handle' is a new alias for `info signals'.
8029 You can now define pre-command hooks, which attach arbitrary command
8030 scripts to any command. The commands in the hook will be executed
8031 prior to the user's command. You can also create a hook which will be
8032 executed whenever the program stops. See gdb.texinfo.
8036 We now deal with Cfront style name mangling, and can even extract type
8037 info from mangled symbols. GDB can automatically figure out which
8038 symbol mangling style your C++ compiler uses.
8040 Calling of methods and virtual functions has been improved as well.
8044 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8045 fixed. This was due to mishandling of the extra N_SO stabs output
8048 We also finally got Ultrix 4.2 running in house, and fixed core file
8049 support, with help from a dozen people on the net.
8051 John M. Farrell discovered that the reason that single-stepping was so
8052 slow on all of the Mips based platforms (primarily SGI and DEC) was
8053 that we were trying to demangle and lookup a symbol used for internal
8054 purposes on every instruction that was being stepped through. Changing
8055 the name of that symbol so that it couldn't be mistaken for a C++
8056 mangled symbol sped things up a great deal.
8058 Rich Pixley sped up symbol lookups in general by getting much smarter
8059 about when C++ symbol mangling is necessary. This should make symbol
8060 completion (TAB on the command line) much faster. It's not as fast as
8061 we'd like, but it's significantly faster than gdb-4.6.
8065 A new user controllable variable 'call_scratch_address' can
8066 specify the location of a scratch area to be used when GDB
8067 calls a function in the target. This is necessary because the
8068 usual method of putting the scratch area on the stack does not work
8069 in systems that have separate instruction and data spaces.
8071 We integrated changes to support the 29k UDI (Universal Debugger
8072 Interface), but discovered at the last minute that we didn't have all
8073 of the appropriate copyright paperwork. We are working with AMD to
8074 resolve this, and hope to have it available soon.
8078 We have sped up the remote serial line protocol, especially for targets
8079 with lots of registers. It now supports a new `expedited status' ('T')
8080 message which can be used in place of the existing 'S' status message.
8081 This allows the remote stub to send only the registers that GDB
8082 needs to make a quick decision about single-stepping or conditional
8083 breakpoints, eliminating the need to fetch the entire register set for
8084 each instruction being stepped through.
8086 The GDB remote serial protocol now implements a write-through cache for
8087 registers, only re-reading the registers if the target has run.
8089 There is also a new remote serial stub for SPARC processors. You can
8090 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8091 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8092 processor with a serial port.
8096 Configure.in files have become much easier to read and modify. A new
8097 `table driven' format makes it more obvious what configurations are
8098 supported, and what files each one uses.
8102 There is a new opcodes library which will eventually contain all of the
8103 disassembly routines and opcode tables. At present, it only contains
8104 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8105 disassembler (binutils/objdump) to share these routines.
8107 The libiberty library is now copylefted under the GNU Library General
8108 Public License. This allows more liberal use, and was done so libg++
8109 can use it. This makes no difference to GDB, since the Library License
8110 grants all the rights from the General Public License.
8114 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8115 reference to the stabs symbol info used by the debugger. It is (as far
8116 as we know) the only published document on this fascinating topic. We
8117 encourage you to read it, compare it to the stabs information on your
8118 system, and send improvements on the document in general (to
8119 bug-gdb@prep.ai.mit.edu).
8121 And, of course, many bugs have been fixed.
8124 *** Changes in GDB-4.6:
8126 * Better support for C++ function names
8128 GDB now accepts as input the "demangled form" of C++ overloaded function
8129 names and member function names, and can do command completion on such names
8130 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8131 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8132 Make use of command completion, it is your friend.
8134 GDB also now accepts a variety of C++ mangled symbol formats. They are
8135 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8136 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8137 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8138 for the list of formats.
8140 * G++ symbol mangling problem
8142 Recent versions of gcc have a bug in how they emit debugging information for
8143 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8144 directory) can be applied to gcc to fix the problem. Alternatively, if you
8145 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8146 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8147 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8150 * New 'maintenance' command
8152 All of the commands related to hacking GDB internals have been moved out of
8153 the main command set, and now live behind the 'maintenance' command. This
8154 can also be abbreviated as 'mt'. The following changes were made:
8156 dump-me -> maintenance dump-me
8157 info all-breakpoints -> maintenance info breakpoints
8158 printmsyms -> maintenance print msyms
8159 printobjfiles -> maintenance print objfiles
8160 printpsyms -> maintenance print psymbols
8161 printsyms -> maintenance print symbols
8163 The following commands are new:
8165 maintenance demangle Call internal GDB demangler routine to
8166 demangle a C++ link name and prints the result.
8167 maintenance print type Print a type chain for a given symbol
8169 * Change to .gdbinit file processing
8171 We now read the $HOME/.gdbinit file before processing the argv arguments
8172 (e.g. reading symbol files or core files). This allows global parameters to
8173 be set, which will apply during the symbol reading. The ./.gdbinit is still
8174 read after argv processing.
8176 * New hosts supported
8178 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8180 GNU/Linux support i386-unknown-linux or linux
8182 We are also including code to support the HP/PA running BSD and HPUX. This
8183 is almost guaranteed not to work, as we didn't have time to test or build it
8184 for this release. We are including it so that the more adventurous (or
8185 masochistic) of you can play with it. We also had major problems with the
8186 fact that the compiler that we got from HP doesn't support the -g option.
8189 * New targets supported
8191 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8193 * More smarts about finding #include files
8195 GDB now remembers the compilation directory for all include files, and for
8196 all files from which C is generated (like yacc and lex sources). This
8197 greatly improves GDB's ability to find yacc/lex sources, and include files,
8198 especially if you are debugging your program from a directory different from
8199 the one that contains your sources.
8201 We also fixed a bug which caused difficulty with listing and setting
8202 breakpoints in include files which contain C code. (In the past, you had to
8203 try twice in order to list an include file that you hadn't looked at before.)
8205 * Interesting infernals change
8207 GDB now deals with arbitrary numbers of sections, where the symbols for each
8208 section must be relocated relative to that section's landing place in the
8209 target's address space. This work was needed to support ELF with embedded
8210 stabs used by Solaris-2.0.
8212 * Bug fixes (of course!)
8214 There have been loads of fixes for the following things:
8215 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8216 i960, stabs, DOS(GO32), procfs, etc...
8218 See the ChangeLog for details.
8220 *** Changes in GDB-4.5:
8222 * New machines supported (host and target)
8224 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8226 SGI Irix-4.x mips-sgi-irix4 or iris4
8228 * New malloc package
8230 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8231 Mmalloc is capable of handling multiple heaps of memory. It is also
8232 capable of saving a heap to a file, and then mapping it back in later.
8233 This can be used to greatly speedup the startup of GDB by using a
8234 pre-parsed symbol table which lives in a mmalloc managed heap. For
8235 more details, please read mmalloc/mmalloc.texi.
8239 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8240 'help info proc' for details.
8242 * MIPS ecoff symbol table format
8244 The code that reads MIPS symbol table format is now supported on all hosts.
8245 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8248 * File name changes for MS-DOS
8250 Many files in the config directories have been renamed to make it easier to
8251 support GDB on MS-DOSe systems (which have very restrictive file name
8252 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8253 environment) is close to working but has some remaining problems. Note
8254 that debugging of DOS programs is not supported, due to limitations
8255 in the ``operating system'', but it can be used to host cross-debugging.
8257 * Cross byte order fixes
8259 Many fixes have been made to support cross debugging of Sparc and MIPS
8260 targets from hosts whose byte order differs.
8262 * New -mapped and -readnow options
8264 If memory-mapped files are available on your system through the 'mmap'
8265 system call, you can use the -mapped option on the `file' or
8266 `symbol-file' commands to cause GDB to write the symbols from your
8267 program into a reusable file. If the program you are debugging is
8268 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8269 Future GDB debugging sessions will notice the presence of this file,
8270 and will quickly map in symbol information from it, rather than reading
8271 the symbol table from the executable program. Using the '-mapped'
8272 option in a GDB `file' or `symbol-file' command has the same effect as
8273 starting GDB with the '-mapped' command-line option.
8275 You can cause GDB to read the entire symbol table immediately by using
8276 the '-readnow' option with any of the commands that load symbol table
8277 information (or on the GDB command line). This makes the command
8278 slower, but makes future operations faster.
8280 The -mapped and -readnow options are typically combined in order to
8281 build a `fred.syms' file that contains complete symbol information.
8282 A simple GDB invocation to do nothing but build a `.syms' file for future
8285 gdb -batch -nx -mapped -readnow programname
8287 The `.syms' file is specific to the host machine on which GDB is run.
8288 It holds an exact image of GDB's internal symbol table. It cannot be
8289 shared across multiple host platforms.
8291 * longjmp() handling
8293 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8294 siglongjmp() without losing control. This feature has not yet been ported to
8295 all systems. It currently works on many 386 platforms, all MIPS-based
8296 platforms (SGI, DECstation, etc), and Sun3/4.
8300 Preliminary work has been put in to support the new Solaris OS from Sun. At
8301 this time, it can control and debug processes, but it is not capable of
8306 As always, many many bug fixes. The major areas were with g++, and mipsread.
8307 People using the MIPS-based platforms should experience fewer mysterious
8308 crashes and trashed symbol tables.
8310 *** Changes in GDB-4.4:
8312 * New machines supported (host and target)
8314 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8316 BSD Reno on Vax vax-dec-bsd
8317 Ultrix on Vax vax-dec-ultrix
8319 * New machines supported (target)
8321 AMD 29000 embedded, using EBMON a29k-none-none
8325 GDB continues to improve its handling of C++. `References' work better.
8326 The demangler has also been improved, and now deals with symbols mangled as
8327 per the Annotated C++ Reference Guide.
8329 GDB also now handles `stabs' symbol information embedded in MIPS
8330 `ecoff' symbol tables. Since the ecoff format was not easily
8331 extensible to handle new languages such as C++, this appeared to be a
8332 good way to put C++ debugging info into MIPS binaries. This option
8333 will be supported in the GNU C compiler, version 2, when it is
8336 * New features for SVR4
8338 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8339 shared libraries. Debugging dynamically linked programs should present
8340 only minor differences from debugging statically linked programs.
8342 The `info proc' command will print out information about any process
8343 on an SVR4 system (including the one you are debugging). At the moment,
8344 it prints the address mappings of the process.
8346 If you bring up GDB on another SVR4 system, please send mail to
8347 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8349 * Better dynamic linking support in SunOS
8351 Reading symbols from shared libraries which contain debugging symbols
8352 now works properly. However, there remain issues such as automatic
8353 skipping of `transfer vector' code during function calls, which
8354 make it harder to debug code in a shared library, than to debug the
8355 same code linked statically.
8359 GDB is now using the latest `getopt' routines from the FSF. This
8360 version accepts the -- prefix for options with long names. GDB will
8361 continue to accept the old forms (-option and +option) as well.
8362 Various single letter abbreviations for options have been explicity
8363 added to the option table so that they won't get overshadowed in the
8364 future by other options that begin with the same letter.
8368 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8369 Many assorted bugs have been handled. Many more remain to be handled.
8370 See the various ChangeLog files (primarily in gdb and bfd) for details.
8373 *** Changes in GDB-4.3:
8375 * New machines supported (host and target)
8377 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8378 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8379 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8381 * Almost SCO Unix support
8383 We had hoped to support:
8384 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8385 (except for core file support), but we discovered very late in the release
8386 that it has problems with process groups that render gdb unusable. Sorry
8387 about that. I encourage people to fix it and post the fixes.
8389 * Preliminary ELF and DWARF support
8391 GDB can read ELF object files on System V Release 4, and can handle
8392 debugging records for C, in DWARF format, in ELF files. This support
8393 is preliminary. If you bring up GDB on another SVR4 system, please
8394 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8399 GDB now uses the latest `readline' library. One user-visible change
8400 is that two tabs will list possible command completions, which previously
8401 required typing M-? (meta-question mark, or ESC ?).
8405 The `stepi' bug that many of you noticed has been squashed.
8406 Many bugs in C++ have been handled. Many more remain to be handled.
8407 See the various ChangeLog files (primarily in gdb and bfd) for details.
8409 * State of the MIPS world (in case you wondered):
8411 GDB can understand the symbol tables emitted by the compilers
8412 supplied by most vendors of MIPS-based machines, including DEC. These
8413 symbol tables are in a format that essentially nobody else uses.
8415 Some versions of gcc come with an assembler post-processor called
8416 mips-tfile. This program is required if you want to do source-level
8417 debugging of gcc-compiled programs. I believe FSF does not ship
8418 mips-tfile with gcc version 1, but it will eventually come with gcc
8421 Debugging of g++ output remains a problem. g++ version 1.xx does not
8422 really support it at all. (If you're lucky, you should be able to get
8423 line numbers and stack traces to work, but no parameters or local
8424 variables.) With some work it should be possible to improve the
8427 When gcc version 2 is released, you will have somewhat better luck.
8428 However, even then you will get confusing results for inheritance and
8431 We will eventually provide full debugging of g++ output on
8432 DECstations. This will probably involve some kind of stabs-in-ecoff
8433 encapulation, but the details have not been worked out yet.
8436 *** Changes in GDB-4.2:
8438 * Improved configuration
8440 Only one copy of `configure' exists now, and it is not self-modifying.
8441 Porting BFD is simpler.
8445 The `step' and `next' commands now only stop at the first instruction
8446 of a source line. This prevents the multiple stops that used to occur
8447 in switch statements, for-loops, etc. `Step' continues to stop if a
8448 function that has debugging information is called within the line.
8452 Lots of small bugs fixed. More remain.
8454 * New host supported (not target)
8456 Intel 386 PC clone running Mach i386-none-mach
8459 *** Changes in GDB-4.1:
8461 * Multiple source language support
8463 GDB now has internal scaffolding to handle several source languages.
8464 It determines the type of each source file from its filename extension,
8465 and will switch expression parsing and number formatting to match the
8466 language of the function in the currently selected stack frame.
8467 You can also specifically set the language to be used, with
8468 `set language c' or `set language modula-2'.
8472 GDB now has preliminary support for the GNU Modula-2 compiler,
8473 currently under development at the State University of New York at
8474 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8475 continue through the fall of 1991 and into 1992.
8477 Other Modula-2 compilers are currently not supported, and attempting to
8478 debug programs compiled with them will likely result in an error as the
8479 symbol table is read. Feel free to work on it, though!
8481 There are hooks in GDB for strict type checking and range checking,
8482 in the `Modula-2 philosophy', but they do not currently work.
8486 GDB can now write to executable and core files (e.g. patch
8487 a variable's value). You must turn this switch on, specify
8488 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8489 by assigning a new value to a variable. Modifications take
8492 * Automatic SunOS shared library reading
8494 When you run your program, GDB automatically determines where its
8495 shared libraries (if any) have been loaded, and reads their symbols.
8496 The `share' command is no longer needed. This also works when
8497 examining core files.
8501 You can specify the number of lines that the `list' command shows.
8504 * New machines supported (host and target)
8506 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8507 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8508 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8510 * New hosts supported (not targets)
8512 IBM RT/PC: romp-ibm-aix or rtpc
8514 * New targets supported (not hosts)
8516 AMD 29000 embedded with COFF a29k-none-coff
8517 AMD 29000 embedded with a.out a29k-none-aout
8518 Ultracomputer remote kernel debug a29k-nyu-kern
8520 * New remote interfaces
8526 *** Changes in GDB-4.0:
8530 Wide output is wrapped at good places to make the output more readable.
8532 Gdb now supports cross-debugging from a host machine of one type to a
8533 target machine of another type. Communication with the target system
8534 is over serial lines. The ``target'' command handles connecting to the
8535 remote system; the ``load'' command will download a program into the
8536 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8537 also supports debugging of realtime processes running under VxWorks,
8538 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8539 stub on the target system.
8541 New CPUs supported include the AMD 29000 and Intel 960.
8543 GDB now reads object files and symbol tables via a ``binary file''
8544 library, which allows a single copy of GDB to debug programs of multiple
8545 object file types such as a.out and coff.
8547 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8548 refcard.dvi and refcard.ps are available to format it).
8551 * Control-Variable user interface simplified
8553 All variables that control the operation of the debugger can be set
8554 by the ``set'' command, and displayed by the ``show'' command.
8556 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8557 ``Show prompt'' produces the response:
8558 Gdb's prompt is new-gdb=>.
8560 What follows are the NEW set commands. The command ``help set'' will
8561 print a complete list of old and new set commands. ``help set FOO''
8562 will give a longer description of the variable FOO. ``show'' will show
8563 all of the variable descriptions and their current settings.
8565 confirm on/off: Enables warning questions for operations that are
8566 hard to recover from, e.g. rerunning the program while
8567 it is already running. Default is ON.
8569 editing on/off: Enables EMACS style command line editing
8570 of input. Previous lines can be recalled with
8571 control-P, the current line can be edited with control-B,
8572 you can search for commands with control-R, etc.
8575 history filename NAME: NAME is where the gdb command history
8576 will be stored. The default is .gdb_history,
8577 or the value of the environment variable
8580 history size N: The size, in commands, of the command history. The
8581 default is 256, or the value of the environment variable
8584 history save on/off: If this value is set to ON, the history file will
8585 be saved after exiting gdb. If set to OFF, the
8586 file will not be saved. The default is OFF.
8588 history expansion on/off: If this value is set to ON, then csh-like
8589 history expansion will be performed on
8590 command line input. The default is OFF.
8592 radix N: Sets the default radix for input and output. It can be set
8593 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8594 in the current radix, so "set radix 10" is always a no-op.
8596 height N: This integer value is the number of lines on a page. Default
8597 is 24, the current `stty rows'' setting, or the ``li#''
8598 setting from the termcap entry matching the environment
8601 width N: This integer value is the number of characters on a line.
8602 Default is 80, the current `stty cols'' setting, or the ``co#''
8603 setting from the termcap entry matching the environment
8606 Note: ``set screensize'' is obsolete. Use ``set height'' and
8607 ``set width'' instead.
8609 print address on/off: Print memory addresses in various command displays,
8610 such as stack traces and structure values. Gdb looks
8611 more ``symbolic'' if you turn this off; it looks more
8612 ``machine level'' with it on. Default is ON.
8614 print array on/off: Prettyprint arrays. New convenient format! Default
8617 print demangle on/off: Print C++ symbols in "source" form if on,
8620 print asm-demangle on/off: Same, for assembler level printouts
8623 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8626 * Support for Epoch Environment.
8628 The epoch environment is a version of Emacs v18 with windowing. One
8629 new command, ``inspect'', is identical to ``print'', except that if you
8630 are running in the epoch environment, the value is printed in its own
8634 * Support for Shared Libraries
8636 GDB can now debug programs and core files that use SunOS shared libraries.
8637 Symbols from a shared library cannot be referenced
8638 before the shared library has been linked with the program (this
8639 happens after you type ``run'' and before the function main() is entered).
8640 At any time after this linking (including when examining core files
8641 from dynamically linked programs), gdb reads the symbols from each
8642 shared library when you type the ``sharedlibrary'' command.
8643 It can be abbreviated ``share''.
8645 sharedlibrary REGEXP: Load shared object library symbols for files
8646 matching a unix regular expression. No argument
8647 indicates to load symbols for all shared libraries.
8649 info sharedlibrary: Status of loaded shared libraries.
8654 A watchpoint stops execution of a program whenever the value of an
8655 expression changes. Checking for this slows down execution
8656 tremendously whenever you are in the scope of the expression, but is
8657 quite useful for catching tough ``bit-spreader'' or pointer misuse
8658 problems. Some machines such as the 386 have hardware for doing this
8659 more quickly, and future versions of gdb will use this hardware.
8661 watch EXP: Set a watchpoint (breakpoint) for an expression.
8663 info watchpoints: Information about your watchpoints.
8665 delete N: Deletes watchpoint number N (same as breakpoints).
8666 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8667 enable N: Re-enables watchpoint number N (same as breakpoints).
8670 * C++ multiple inheritance
8672 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8675 * C++ exception handling
8677 Gdb now supports limited C++ exception handling. Besides the existing
8678 ability to breakpoint on an exception handler, gdb can breakpoint on
8679 the raising of an exception (before the stack is peeled back to the
8682 catch FOO: If there is a FOO exception handler in the dynamic scope,
8683 set a breakpoint to catch exceptions which may be raised there.
8684 Multiple exceptions (``catch foo bar baz'') may be caught.
8686 info catch: Lists all exceptions which may be caught in the
8687 current stack frame.
8690 * Minor command changes
8692 The command ``call func (arg, arg, ...)'' now acts like the print
8693 command, except it does not print or save a value if the function's result
8694 is void. This is similar to dbx usage.
8696 The ``up'' and ``down'' commands now always print the frame they end up
8697 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8698 frames without printing.
8700 * New directory command
8702 'dir' now adds directories to the FRONT of the source search path.
8703 The path starts off empty. Source files that contain debug information
8704 about the directory in which they were compiled can be found even
8705 with an empty path; Sun CC and GCC include this information. If GDB can't
8706 find your source file in the current directory, type "dir .".
8708 * Configuring GDB for compilation
8710 For normal use, type ``./configure host''. See README or gdb.texinfo
8713 GDB now handles cross debugging. If you are remotely debugging between
8714 two different machines, type ``./configure host -target=targ''.
8715 Host is the machine where GDB will run; targ is the machine
8716 where the program that you are debugging will run.