1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 12
6 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
8 * Remove support for building against Python 2, it is now only possible to
9 build GDB against Python 3.
11 * DBX mode has been removed.
15 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
16 that formats ADDRESS as 'address <symbol+offset>', where symbol is
17 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
18 This is the same format that GDB uses when printing address, symbol,
19 and offset information from the disassembler.
23 * DBX mode is deprecated, and will be removed in GDB 13
25 * GDB 12 is the last release of GDB that will support building against
26 Python 2. From GDB 13, it will only be possible to build GDB itself
27 with Python 3 support.
29 * Improved C++ template support
31 GDB now treats functions/types involving C++ templates like it does function
32 overloads. Users may omit parameter lists to set breakpoints on families of
33 template functions, including types/functions composed of multiple template types:
35 (gdb) break template_func(template_1, int)
37 The above will set breakpoints at every function `template_func' where
38 the first function parameter is any template type named `template_1' and
39 the second function parameter is `int'.
41 TAB completion also gains similar improvements.
43 * The FreeBSD native target now supports async mode.
49 Enable or disable multithreaded symbol loading. This is enabled
50 by default, but passing --disable-threading or --enable-threading=no
51 to configure will disable it.
53 Disabling this can cause a performance penalty when there are a lot of
54 symbols to load, but is useful for debugging purposes.
58 maint set backtrace-on-fatal-signal on|off
59 maint show backtrace-on-fatal-signal
60 This setting is 'on' by default. When 'on' GDB will print a limited
61 backtrace to stderr in the situation where GDB terminates with a
62 fatal signal. This only supported on some platforms where the
63 backtrace and backtrace_symbols_fd functions are available.
65 set source open on|off
67 This setting, which is on by default, controls whether GDB will try
68 to open source code files. Switching this off will stop GDB trying
69 to open and read source code files, which can be useful if the files
70 are located over a slow network connection.
74 These are now deprecated aliases for "set max-value-size" and
75 "show max-value-size".
77 task apply [all | TASK-IDS...] [FLAG]... COMMAND
78 Like "thread apply", but applies COMMAND to Ada tasks.
81 Watchpoints can now be restricted to a specific Ada task.
83 maint set internal-error backtrace on|off
84 maint show internal-error backtrace
85 maint set internal-warning backtrace on|off
86 maint show internal-warning backtrace
87 GDB can now print a backtrace of itself when it encounters either an
88 internal-error, or an internal-warning. This is on by default for
89 internal-error and off by default for internal-warning.
92 Deprecated and replaced by "set logging enabled on|off".
94 set logging enabled on|off
96 These commands set or show whether logging is enabled or disabled.
99 You can now exit GDB by using the new command "exit", in addition to
100 the existing "quit" command.
102 set debug threads on|off
104 Print additional debug messages about thread creation and deletion.
106 set debug linux-nat on|off
108 These new commands replaced the old 'set debug lin-lwp' and 'show
109 debug lin-lwp' respectively. Turning this setting on prints debug
110 messages relating to GDB's handling of native Linux inferiors.
112 maint flush source-cache
113 Flush the contents of the source code cache.
115 maint set gnu-source-highlight enabled on|off
116 maint show gnu-source-highlight enabled
117 Whether GDB should use the GNU Source Highlight library for adding
118 styling to source code. When off, the library will not be used, even
119 when available. When GNU Source Highlight isn't used, or can't add
120 styling to a particular source file, then the Python Pygments
121 library will be used instead.
123 set suppress-cli-notifications (on|off)
124 show suppress-cli-notifications
125 This controls whether printing the notifications is suppressed for CLI.
126 CLI notifications occur when you change the selected context
127 (i.e., the current inferior, thread and/or the frame), or when
128 the program being debugged stops (e.g., because of hitting a
129 breakpoint, completing source-stepping, an interrupt, etc.).
131 set style disassembler enabled on|off
132 show style disassembler enabled
133 If GDB is compiled with Python support, and the Python Pygments
134 package is available, then, when this setting is on, disassembler
135 output will have styling applied.
137 set ada source-charset
138 show ada source-charset
139 Set the character set encoding that is assumed for Ada symbols. Valid
140 values for this follow the values that can be passed to the GNAT
141 compiler via the '-gnati' option. The default is ISO-8859-1.
147 These are the new names for the old 'layout', 'focus', 'refresh',
148 and 'winheight' tui commands respectively. The old names still
149 exist as aliases to these new commands.
153 The new command 'tui window width', and the alias 'winwidth' allow
154 the width of a tui window to be adjusted when windows are laid out
159 Control the display of debug output about GDB's tui.
164 Printing of floating-point values with base-modifying formats like
165 /x has been changed to display the underlying bytes of the value in
166 the desired base. This was GDB's documented behavior, but was never
167 implemented correctly.
170 This command can now print a reply, if the reply includes
171 non-printable characters. Any non-printable characters are printed
172 as escaped hex, e.g. \x?? where '??' is replaces with the value of
173 the non-printable character.
176 The clone-inferior command now ensures that the TTY, CMD and ARGS
177 settings are copied from the original inferior to the new one.
178 All modifications to the environment variables done using the 'set
179 environment' or 'unset environment' commands are also copied to the new
182 set debug lin-lwp on|off
184 These commands have been removed from GDB. The new command 'set
185 debug linux-nat' and 'show debug linux-nat' should be used
189 This command now includes information about the width of the tui
190 windows in its output.
196 These commands are now aliases for the 'tui layout', 'tui focus',
197 'tui refresh', and 'tui window height' commands respectively.
199 * GDB's Ada parser now supports an extension for specifying the exact
200 byte contents of a floating-point literal. This can be useful for
201 setting floating-point registers to a precise value without loss of
202 precision. The syntax is an extension of the based literal syntax.
203 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
204 of the floating-point type, and the "f" is the marker for floating
209 ** The '-add-inferior' with no option flags now inherits the
210 connection of the current inferior, this restores the behaviour of
211 GDB as it was prior to GDB 10.
213 ** The '-add-inferior' command now accepts a '--no-connection'
214 option, which causes the new inferior to start without a
219 GNU/Linux/LoongArch loongarch*-*-linux*
227 ** New function gdb.add_history(), which takes a gdb.Value object
228 and adds the value it represents to GDB's history list. An
229 integer, the index of the new item in the history list, is
232 ** New function gdb.history_count(), which returns the number of
233 values in GDB's value history.
235 ** New gdb.events.gdb_exiting event. This event is called with a
236 gdb.GdbExitingEvent object which has the read-only attribute
237 'exit_code', which contains the value of the GDB exit code. This
238 event is triggered once GDB decides it is going to exit, but
239 before GDB starts to clean up its internal state.
241 ** New function gdb.architecture_names(), which returns a list
242 containing all of the possible Architecture.name() values. Each
245 ** New function gdb.Architecture.integer_type(), which returns an
246 integer type given a size and a signed-ness.
248 ** New gdb.TargetConnection object type that represents a connection
249 (as displayed by the 'info connections' command). A sub-class,
250 gdb.RemoteTargetConnection, is used to represent 'remote' and
251 'extended-remote' connections.
253 ** The gdb.Inferior type now has a 'connection' property which is an
254 instance of gdb.TargetConnection, the connection used by this
255 inferior. This can be None if the inferior has no connection.
257 ** New 'gdb.events.connection_removed' event registry, which emits a
258 'gdb.ConnectionEvent' when a connection is removed from GDB.
259 This event has a 'connection' property, a gdb.TargetConnection
260 object for the connection being removed.
262 ** New gdb.connections() function that returns a list of all
263 currently active connections.
265 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
266 is equivalent to the existing 'maint packet' CLI command; it
267 allows a user specified packet to be sent to the remote target.
269 ** New function gdb.host_charset(), returns a string, which is the
270 name of the current host charset.
272 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
275 ** New gdb.with_parameter(NAME, VALUE). This returns a context
276 manager that temporarily sets the gdb parameter NAME to VALUE,
277 then resets it when the context is exited.
279 ** The gdb.Value.format_string method now takes a 'styling'
280 argument, which is a boolean. When true, the returned string can
281 include escape sequences to apply styling. The styling will only
282 be present if styling is otherwise turned on in GDB (see 'help
283 set styling'). When false, which is the default if the argument
284 is not given, then no styling is applied to the returned string.
286 ** New read-only attribute gdb.InferiorThread.details, which is
287 either a string, containing additional, target specific thread
288 state information, or None, if there is no such additional
291 ** New read-only attribute gdb.Type.is_scalar, which is True for
292 scalar types, and False for all other types.
294 ** New read-only attribute gdb.Type.is_signed. This attribute
295 should only be read when Type.is_scalar is True, and will be True
296 for signed types, and False for all other types. Attempting to
297 read this attribute for non-scalar types will raise a ValueError.
299 ** It is now possible to add GDB/MI commands implemented in Python.
301 * New features in the GDB remote stub, GDBserver
303 ** GDBserver is now supported on OpenRISC GNU/Linux.
305 * New native configurations
307 GNU/Linux/OpenRISC or1k*-*-linux*
309 *** Changes in GDB 11
311 * The 'set disassembler-options' command now supports specifying options
314 * GDB now supports general memory tagging functionality if the underlying
315 architecture supports the proper primitives and hooks. Currently this is
316 enabled only for AArch64 MTE.
320 - Additional information when the inferior crashes with a SIGSEGV caused by
321 a memory tag violation.
323 - A new modifier 'm' for the "x" command, which displays allocation tags for a
324 particular memory range.
326 - Display of memory tag mismatches by "print", for addresses and
327 pointers, if memory tagging is supported by the architecture.
329 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
334 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
336 The MI -break-insert and -dprintf-insert commands now support a
337 new "--qualified" option that makes GDB interpret a specified
338 function name as a complete fully-qualified name. This is the
339 equivalent of the CLI's "break -qualified" and "dprintf
342 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
344 The MI -break-insert and -dprintf-insert commands now support a
345 '--force-condition' flag to forcibly define a condition even when
346 the condition is invalid at all locations of the breakpoint. This
347 is equivalent to the '-force-condition' flag of the CLI's "break"
350 ** '-break-condition --force'
352 The MI -break-condition command now supports a '--force' flag to
353 forcibly define a condition even when the condition is invalid at
354 all locations of the selected breakpoint. This is equivalent to
355 the '-force' flag of the CLI's "cond" command.
357 ** '-file-list-exec-source-files [--group-by-objfile]
358 [--basename | --dirname]
361 The existing -file-list-exec-source-files command now takes an
362 optional REGEXP which is used to filter the source files that are
363 included in the results.
365 By default REGEXP is matched against the full filename of the
366 source file. When one of --basename or --dirname is given then
367 REGEXP is only matched against the specified part of the full
370 When the optional --group-by-objfile flag is used the output
371 format is changed, the results are now a list of object files
372 (executable and libraries) with the source files that are
373 associated with each object file.
375 The results from -file-list-exec-source-files now include a
376 'debug-fully-read' field which takes the value 'true' or 'false'.
377 A 'true' value indicates the source file is from a compilation
378 unit that has had its debug information fully read in by GDB, a
379 value of 'false' indicates GDB has only performed a partial scan
380 of the debug information so far.
382 * GDB now supports core file debugging for x86_64 Cygwin programs.
384 * GDB will now look for the .gdbinit file in a config directory before
385 looking for ~/.gdbinit. The file is searched for in the following
386 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
387 $HOME/.gdbinit. On Apple hosts the search order is instead:
388 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
390 * GDB now supports fixed point types which are described in DWARF
391 as base types with a fixed-point encoding. Additionally, support
392 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
395 For Ada, this allows support for fixed point types without requiring
396 the use of the GNAT encoding (based on information added to the type's
397 name following a GNAT-specific format).
399 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
400 or ~/.gdbearlyinit if these files are present. These files are
401 processed earlier than any of the other initialization files and
402 can affect parts of GDB's startup that previously had already been
403 completed before the initialization files were read, for example
404 styling of the initial GDB greeting.
406 * GDB now has two new options "--early-init-command" and
407 "--early-init-eval-command" with corresponding short options "-eix"
408 and "-eiex" that allow options (that would normally appear in a
409 gdbearlyinit file) to be passed on the command line.
411 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
412 now understood by GDB, and can be used to describe the vector
413 registers of a target. The precise requirements of this register
414 feature are documented in the GDB manual.
416 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
417 supported by GDB and describes a new VPR register from the ARM MVE
418 (Helium) extension. See the GDB manual for more information.
422 ** TUI windows now support mouse actions. The mouse wheel scrolls
423 the appropriate window.
425 ** Key combinations that do not have a specific action on the
426 focused window are passed to GDB. For example, you now can use
427 Ctrl-Left/Ctrl-Right to move between words in the command window
428 regardless of which window is in focus. Previously you would
429 need to focus on the command window for such key combinations to
435 show debug event-loop
436 Control the display of debug output about GDB's event loop.
438 set print memory-tag-violations
439 show print memory-tag-violations
440 Control whether to display additional information about memory tag violations
441 when printing pointers and addresses. Architecture support for memory
442 tagging is required for this option to have an effect.
444 maintenance flush symbol-cache
445 maintenance flush register-cache
446 These new commands are equivalent to the already existing commands
447 'maintenance flush-symbol-cache' and 'flushregs' respectively.
449 maintenance flush dcache
450 A new command to flush the dcache.
452 maintenance info target-sections
453 Print GDB's internal target sections table.
456 Print the JIT code objects in the inferior known to GDB.
458 memory-tag show-logical-tag POINTER
459 Print the logical tag for POINTER.
460 memory-tag with-logical-tag POINTER TAG
461 Print POINTER with logical tag TAG.
462 memory-tag show-allocation-tag ADDRESS
463 Print the allocation tag for ADDRESS.
464 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
465 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
466 memory-tag check POINTER
467 Validate that POINTER's logical tag matches the allocation tag.
469 set startup-quietly on|off
471 When 'on', this causes GDB to act as if "-silent" were passed on the
472 command line. This command needs to be added to an early
473 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
476 set print type hex on|off
478 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
479 and offsets of struct members. When 'off', decimal notation is used.
481 set python ignore-environment on|off
482 show python ignore-environment
483 When 'on', this causes GDB's builtin Python to ignore any
484 environment variables that would otherwise affect how Python
485 behaves. This command needs to be added to an early initialization
486 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
488 set python dont-write-bytecode auto|on|off
489 show python dont-write-bytecode
490 When 'on', this causes GDB's builtin Python to not write any
491 byte-code (.pyc files) to disk. This command needs to be added to
492 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
493 order to affect GDB. When 'off' byte-code will always be written.
494 When set to 'auto' (the default) Python will check the
495 PYTHONDONTWRITEBYTECODE environment variable.
499 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
500 [-force-condition] [if CONDITION]
501 This command would previously refuse setting a breakpoint if the
502 CONDITION expression is invalid at a location. It now accepts and
503 defines the breakpoint if there is at least one location at which
504 the CONDITION is valid. The locations for which the CONDITION is
505 invalid, are automatically disabled. If CONDITION is invalid at all
506 of the locations, setting the breakpoint is still rejected. However,
507 the '-force-condition' flag can be used in this case for forcing GDB to
508 define the breakpoint, making all the current locations automatically
509 disabled. This may be useful if the user knows the condition will
510 become meaningful at a future location, e.g. due to a shared library
513 condition [-force] N COND
514 The behavior of this command is changed the same way for the 'break'
515 command as explained above. The '-force' flag can be used to force
516 GDB into defining the condition even when COND is invalid for all the
517 current locations of breakpoint N.
520 maintenance flush-symbol-cache
521 These commands are deprecated in favor of the new commands
522 'maintenance flush register-cache' and 'maintenance flush
523 symbol-cache' respectively.
525 set style version foreground COLOR
526 set style version background COLOR
527 set style version intensity VALUE
528 Control the styling of GDB's version number text.
531 When the ID parameter is omitted, then this command prints information
532 about the current inferior. When the ID parameter is present, the
533 behavior of the command is unchanged and have the inferior ID become
534 the current inferior.
536 maintenance info sections
537 The ALLOBJ keyword has been replaced with an -all-objects command
538 line flag. It is now possible to filter which sections are printed
539 even when -all-objects is passed.
541 ptype[/FLAGS] TYPE | EXPRESSION
542 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
543 notation is used when printing sizes and offsets of struct members.
544 When '/d' is set, decimal notation is used when printing sizes and
545 offsets of struct members. Default behavior is given by 'show print
549 The info sources command output has been restructured. The results
550 are now based around a list of objfiles (executable and libraries),
551 and for each objfile the source files that are part of that objfile
554 * Removed targets and native configurations
556 ARM Symbian arm*-*-symbianelf*
561 Request the remote to send allocation tags for a particular memory range.
563 Request the remote to store the specified allocation tags to the requested
568 ** Improved support for rvalue reference values:
569 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
570 value-referenced-value procedure now handles rvalue reference
573 ** New procedures for obtaining value variants:
574 value-reference-value, value-rvalue-reference-value and
577 ** Temporary breakpoints can now be created with make-breakpoint and
578 tested for using breakpoint-temporary?.
582 ** Inferior objects now contain a read-only 'connection_num' attribute that
583 gives the connection number as seen in 'info connections' and
586 ** New method gdb.Frame.level() which returns the stack level of the
589 ** New method gdb.PendingFrame.level() which returns the stack level
592 ** When hitting a catchpoint, the Python API will now emit a
593 gdb.BreakpointEvent rather than a gdb.StopEvent. The
594 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
596 ** Python TUI windows can now receive mouse click events. If the
597 Window object implements the click method, it is called for each
598 mouse click event in this window.
600 *** Changes in GDB 10
602 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
603 and "org.gnu.gdb.arc.aux". The old names are still supported but
604 must be considered obsolete. They will be deprecated after some
607 * Help and apropos commands will now show the documentation of a
608 command only once, even if that command has one or more aliases.
609 These commands now show the command name, then all of its aliases,
610 and finally the description of the command.
612 * 'help aliases' now shows only the user defined aliases. GDB predefined
613 aliases are shown together with their aliased command.
615 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
616 debugging information as well as source code.
618 When built with debuginfod, GDB can automatically query debuginfod
619 servers for the separate debug files and source code of the executable
622 To build GDB with debuginfod, pass --with-debuginfod to configure (this
623 requires libdebuginfod, the debuginfod client library).
625 debuginfod is distributed with elfutils, starting with version 0.178.
627 You can get the latest version from https://sourceware.org/elfutils.
629 * Multi-target debugging support
631 GDB now supports debugging multiple target connections
632 simultaneously. For example, you can now have each inferior
633 connected to different remote servers running in different machines,
634 or have one inferior debugging a local native process, an inferior
635 debugging a core dump, etc.
637 This support is experimental and comes with some limitations -- you
638 can only resume multiple targets simultaneously if all targets
639 support non-stop mode, and all remote stubs or servers must support
640 the same set of remote protocol features exactly. See also "info
641 connections" and "add-inferior -no-connection" below, and "maint set
642 target-non-stop" in the user manual.
644 * New features in the GDB remote stub, GDBserver
646 ** GDBserver is now supported on ARC GNU/Linux.
648 ** GDBserver is now supported on RISC-V GNU/Linux.
650 ** GDBserver no longer supports these host triplets:
661 i[34567]86-*-mingw32ce*
663 * Debugging MS-Windows processes now sets $_exitsignal when the
664 inferior is terminated by a signal, instead of setting $_exitcode.
666 * Multithreaded symbol loading has now been enabled by default on systems
667 that support it (see entry for GDB 9, below), providing faster
668 performance for programs with many symbols.
670 * The $_siginfo convenience variable now also works on Windows targets,
671 and will display the EXCEPTION_RECORD of the last handled exception.
673 * TUI windows can now be arranged horizontally.
675 * The command history filename can now be set to the empty string
676 either using 'set history filename' or by setting 'GDBHISTFILE=' in
677 the environment. The effect of setting this filename to the empty
678 string is that GDB will not try to load any previous command
681 * On Windows targets, it is now possible to debug 32-bit programs with a
686 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
687 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
688 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
689 running process, this new option indicates whether to detect
690 a mismatch between the current executable file loaded by GDB and the
691 executable file used to start the process. If 'ask', the default,
692 display a warning and ask the user whether to load the process
693 executable file; if 'warn', just display a warning; if 'off', don't
694 attempt to detect a mismatch.
696 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
697 Define a new TUI layout, specifying its name and the windows that
700 maintenance print xml-tdesc [FILE]
701 Prints the current target description as an XML document. If the
702 optional FILE is provided (which is an XML target description) then
703 the target description is read from FILE into GDB, and then
706 maintenance print core-file-backed-mappings
707 Prints file-backed mappings loaded from a core file's note section.
708 Output is expected to be similar to that of "info proc mappings".
710 set debug fortran-array-slicing on|off
711 show debug fortran-array-slicing
712 Print debugging when taking slices of Fortran arrays.
714 set fortran repack-array-slices on|off
715 show fortran repack-array-slices
716 When taking slices from Fortran arrays and strings, if the slice is
717 non-contiguous within the original value then, when this option is
718 on, the new value will be repacked into a single contiguous value.
719 When this option is off, then the value returned will consist of a
720 descriptor that describes the slice within the memory of the
721 original parent value.
725 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
726 The alias command can now specify default args for an alias.
727 GDB automatically prepends the alias default args to the argument list
728 provided explicitly by the user.
729 For example, to have a backtrace with full details, you can define
731 'alias bt_ALL = backtrace -entry-values both -frame-arg all
732 -past-main -past-entry -full'.
733 Alias default arguments can also use a set of nested 'with' commands,
734 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
735 defines the alias pp10 that will pretty print a maximum of 10 elements
736 of the given expression (if the expression is an array).
740 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
746 ** gdb.register_window_type can be used to implement new TUI windows
749 ** Dynamic types can now be queried. gdb.Type has a new attribute,
750 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
751 field of a dynamic type may have None for its "bitpos" attribute
754 ** Commands written in Python can be in the "TUI" help class by
755 registering with the new constant gdb.COMMAND_TUI.
757 ** New method gdb.PendingFrame.architecture () to retrieve the
758 architecture of the pending frame.
760 ** New gdb.Architecture.registers method that returns a
761 gdb.RegisterDescriptorIterator object, an iterator that returns
762 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
763 way to query the registers available for an architecture.
765 ** New gdb.Architecture.register_groups method that returns a
766 gdb.RegisterGroupIterator object, an iterator that returns
767 gdb.RegisterGroup objects. The new RegisterGroup is a way to
768 discover the available register groups.
772 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
774 ** Procedures 'memory-port-read-buffer-size',
775 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
776 and 'set-memory-port-write-buffer-size!' are deprecated. When
777 using Guile 2.2 and later, users who need to control the size of
778 a memory port's internal buffer can use the 'setvbuf' procedure.
782 * 'thread-exited' event is now available in the annotations interface.
784 * New built-in convenience variables $_gdb_major and $_gdb_minor
785 provide the GDB version. They are handy for conditionally using
786 features available only in or since specific GDB versions, in
787 scripts that should work error-free with many different versions,
788 such as in system-wide init files.
790 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
791 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
792 of the GDB settings and the GDB maintenance settings. They are handy
793 for changing the logic of user defined commands depending on the
794 current GDB settings.
796 * GDB now supports Thread Local Storage (TLS) variables on several
797 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
798 architectures require kernel changes. TLS is not yet supported for
799 amd64 and i386 process core dumps.
801 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
802 addresses that required unmasking are shown in the backtrace with the
805 * Two new convenience functions $_cimag and $_creal that extract the
806 imaginary and real parts respectively from complex numbers.
808 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
809 provide the exitcode or exit status of the shell commands launched by
810 GDB commands such as "shell", "pipe" and "make".
812 * The command define-prefix can now define user defined prefix commands.
813 User defined commands can now be defined using these user defined prefix
816 * Command names can now use the . character.
818 * The RX port now supports XML target descriptions.
820 * GDB now shows the Ada task names at more places, e.g. in task switching
823 * GDB can now be compiled with Python 3 on Windows.
825 * New convenience variable $_ada_exception holds the address of the
826 Ada exception being thrown. This is set by Ada-related catchpoints.
828 * GDB can now place breakpoints on nested functions and subroutines in
829 Fortran code. The '::' operator can be used between parent and
830 child scopes when placing breakpoints, for example:
832 (gdb) break outer_function::inner_function
834 The 'outer_function::' prefix is only needed if 'inner_function' is
835 not visible in the current scope.
837 * In addition to the system-wide gdbinit file, if configured with
838 --with-system-gdbinit-dir, GDB will now also load files in that directory
839 as system gdbinit files, unless the -nx or -n flag is provided. Files
840 with extensions .gdb, .py and .scm are supported as long as GDB was
841 compiled with support for that language.
843 * GDB now supports multithreaded symbol loading for higher performance.
844 This feature is still in testing, so it is disabled by default. You
845 can turn it on using 'maint set worker-threads unlimited'.
849 ** The gdb.Value type has a new method 'format_string' which returns a
850 string representing the value. The formatting is controlled by the
851 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
852 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
853 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
855 ** gdb.Type has a new property 'objfile' which returns the objfile the
858 ** The frame information printed by the python frame filtering code
859 is now consistent with what the 'backtrace' command prints when
860 there are no filters, or when the 'backtrace' '-no-filters' option
863 ** The new function gdb.lookup_static_symbol can be used to look up
864 symbols with static linkage.
866 ** The new function gdb.lookup_static_symbols can be used to look up
867 all static symbols with static linkage.
869 ** gdb.Objfile has new methods 'lookup_global_symbol' and
870 'lookup_static_symbol' to lookup a symbol from this objfile only.
872 ** gdb.Block now supports the dictionary syntax for accessing symbols in
873 this block (e.g. block['local_variable']).
877 | [COMMAND] | SHELL_COMMAND
878 | -d DELIM COMMAND DELIM SHELL_COMMAND
879 pipe [COMMAND] | SHELL_COMMAND
880 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
881 Executes COMMAND and sends its output to SHELL_COMMAND.
882 With no COMMAND, repeat the last executed command
883 and send its output to SHELL_COMMAND.
885 define-prefix COMMAND
886 Define or mark a command as a user-defined prefix command.
888 with SETTING [VALUE] [-- COMMAND]
889 w SETTING [VALUE] [-- COMMAND]
890 Temporarily set SETTING, run COMMAND, and restore SETTING.
891 Usage: with SETTING -- COMMAND
892 With no COMMAND, repeats the last executed command.
893 SETTING is any GDB setting you can change with the "set"
894 subcommands. For example, 'with language c -- print someobj'
895 temporarily switches to the C language in order to print someobj.
896 Settings can be combined: 'w lang c -- w print elements unlimited --
897 usercmd' switches to the C language and runs usercmd with no limit
898 of array elements to print.
900 maint with SETTING [VALUE] [-- COMMAND]
901 Like "with", but works with "maintenance set" settings.
903 set may-call-functions [on|off]
904 show may-call-functions
905 This controls whether GDB will attempt to call functions in
906 the program, such as with expressions in the print command. It
907 defaults to on. Calling functions in the program being debugged
908 can have undesired side effects. It is now possible to forbid
909 such function calls. If function calls are forbidden, GDB will throw
910 an error when a command (such as print expression) calls a function
913 set print finish [on|off]
915 This controls whether the `finish' command will display the value
916 that is returned by the current function. When `off', the value is
917 still entered into the value history, but it is not printed. The
922 Allows deeply nested structures to be simplified when printing by
923 replacing deeply nested parts (beyond the max-depth) with ellipses.
924 The default max-depth is 20, but this can be set to unlimited to get
925 the old behavior back.
927 set print raw-values [on|off]
928 show print raw-values
929 By default, GDB applies the enabled pretty printers when printing a
930 value. This allows to ignore the enabled pretty printers for a series
931 of commands. The default is 'off'.
933 set logging debugredirect [on|off]
934 By default, GDB debug output will go to both the terminal and the logfile.
935 Set if you want debug output to go only to the log file.
937 set style title foreground COLOR
938 set style title background COLOR
939 set style title intensity VALUE
940 Control the styling of titles.
942 set style highlight foreground COLOR
943 set style highlight background COLOR
944 set style highlight intensity VALUE
945 Control the styling of highlightings.
947 maint set worker-threads
948 maint show worker-threads
949 Control the number of worker threads that can be used by GDB. The
950 default is 0. "unlimited" lets GDB choose a number that is
951 reasonable. Currently worker threads are only used when demangling
952 the names of linker symbols.
954 set style tui-border foreground COLOR
955 set style tui-border background COLOR
956 Control the styling of TUI borders.
958 set style tui-active-border foreground COLOR
959 set style tui-active-border background COLOR
960 Control the styling of the active TUI border.
962 maint set test-settings KIND
963 maint show test-settings KIND
964 A set of commands used by the testsuite for exercising the settings
967 maint set tui-resize-message [on|off]
968 maint show tui-resize-message
969 Control whether GDB prints a message each time the terminal is
970 resized when in TUI mode. This is primarily useful for testing the
973 set print frame-info [short-location|location|location-and-address
974 |source-and-location|source-line|auto]
975 show print frame-info
976 This controls what frame information is printed by the commands printing
977 a frame. This setting will e.g. influence the behaviour of 'backtrace',
978 'frame', 'stepi'. The python frame filtering also respect this setting.
979 The 'backtrace' '-frame-info' option can override this global setting.
981 set tui compact-source
982 show tui compact-source
984 Enable the "compact" display mode for the TUI source window. The
985 compact display uses only as much space as is needed for the line
986 numbers in the current file, and only a single space to separate the
987 line numbers from the source.
989 info modules [-q] [REGEXP]
990 Return a list of Fortran modules matching REGEXP, or all modules if
993 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
994 Return a list of functions within all modules, grouped by module.
995 The list of functions can be restricted with the optional regular
996 expressions. MODULE_REGEXP matches against the module name,
997 TYPE_REGEXP matches against the function type signature, and REGEXP
998 matches against the function name.
1000 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1001 Return a list of variables within all modules, grouped by module.
1002 The list of variables can be restricted with the optional regular
1003 expressions. MODULE_REGEXP matches against the module name,
1004 TYPE_REGEXP matches against the variable type, and REGEXP matches
1005 against the variable name.
1007 set debug remote-packet-max-chars
1008 show debug remote-packet-max-chars
1009 Controls the number of characters to output in a remote packet when using
1011 The default is 512 bytes.
1014 Lists the target connections currently in use.
1019 The "help" command uses the title style to enhance the
1020 readibility of its output by styling the classes and
1024 Similarly to "help", the "apropos" command also uses the
1025 title style for the command names. "apropos" accepts now
1026 a flag "-v" (verbose) to show the full documentation
1027 of matching commands and to use the highlight style to mark
1028 the documentation parts matching REGEXP.
1032 The GDB printf and eval commands can now print C-style and Ada-style
1033 string convenience variables without calling functions in the program.
1034 This allows to do formatted printing of strings without having
1035 a running inferior, or when debugging a core dump.
1037 info sources [-dirname | -basename] [--] [REGEXP]
1038 This command has now optional arguments to only print the files
1039 whose names match REGEXP. The arguments -dirname and -basename
1040 allow to restrict matching respectively to the dirname and basename
1044 The "show style" and its subcommands are now styling
1045 a style name in their output using its own style, to help
1046 the user visualize the different styles.
1048 set print frame-arguments
1049 The new value 'presence' indicates to only indicate the presence of
1050 arguments using ..., instead of printing argument names and values.
1052 set print raw-frame-arguments
1053 show print raw-frame-arguments
1055 These commands replace the similarly-named "set/show print raw
1056 frame-arguments" commands (now with a dash instead of a space). The
1057 old commands are now deprecated and may be removed in a future
1060 add-inferior [-no-connection]
1061 The add-inferior command now supports a "-no-connection" flag that
1062 makes the new inferior start with no target connection associated.
1063 By default, the new inferior inherits the target connection of the
1064 current inferior. See also "info connections".
1067 This command's output now includes a new "Connection" column
1068 indicating which target connection an inferior is bound to. See
1069 "info connections" above.
1071 maint test-options require-delimiter
1072 maint test-options unknown-is-error
1073 maint test-options unknown-is-operand
1074 maint show test-options-completion-result
1075 Commands used by the testsuite to validate the command options
1078 focus, winheight, +, -, >, <
1079 These commands are now case-sensitive.
1081 * New command options, command completion
1083 GDB now has a standard infrastructure to support dash-style command
1084 options ('-OPT'). One benefit is that commands that use it can
1085 easily support completion of command line arguments. Try "CMD
1086 -[TAB]" or "help CMD" to find options supported by a command. Over
1087 time, we intend to migrate most commands to this infrastructure. A
1088 number of commands got support for new command options in this
1091 ** The "print" and "compile print" commands now support a number of
1092 options that allow overriding relevant global print settings as
1093 set by "set print" subcommands:
1097 -array-indexes [on|off]
1098 -elements NUMBER|unlimited
1102 -raw-values [on|off]
1103 -repeats NUMBER|unlimited
1104 -static-members [on|off]
1109 Note that because the "print"/"compile print" commands accept
1110 arbitrary expressions which may look like options (including
1111 abbreviations), if you specify any command option, then you must
1112 use a double dash ("--") to mark the end of argument processing.
1114 ** The "backtrace" command now supports a number of options that
1115 allow overriding relevant global print settings as set by "set
1116 backtrace" and "set print" subcommands:
1118 -entry-values no|only|preferred|if-needed|both|compact|default
1119 -frame-arguments all|scalars|none
1120 -raw-frame-arguments [on|off]
1121 -frame-info auto|source-line|location|source-and-location
1122 |location-and-address|short-location
1124 -past-entry [on|off]
1126 In addition, the full/no-filters/hide qualifiers are now also
1127 exposed as command options too:
1133 ** The "frame apply", "tfaas" and "faas" commands similarly now
1134 support the following options:
1137 -past-entry [on|off]
1139 ** The new "info sources" options -dirname and -basename options
1140 are using the standard '-OPT' infrastructure.
1142 All options above can also be abbreviated. The argument of boolean
1143 (on/off) options can be 0/1 too, and also the argument is assumed
1144 "on" if omitted. This allows writing compact command invocations,
1147 (gdb) p -ra -p -o 0 -- *myptr
1149 The above is equivalent to:
1151 (gdb) print -raw-values -pretty -object off -- *myptr
1153 ** The "info types" command now supports the '-q' flag to disable
1154 printing of some header information in a similar fashion to "info
1155 variables" and "info functions".
1157 ** The "info variables", "info functions", and "whereis" commands
1158 now take a '-n' flag that excludes non-debug symbols (symbols
1159 from the symbol table, not from the debug info such as DWARF)
1162 * Completion improvements
1164 ** GDB can now complete the options of the "thread apply all" and
1165 "taas" commands, and their "-ascending" option can now be
1168 ** GDB can now complete the options of the "info threads", "info
1169 functions", "info variables", "info locals", and "info args"
1172 ** GDB can now complete the options of the "compile file" and
1173 "compile code" commands. The "compile file" command now
1174 completes on filenames.
1176 ** GDB can now complete the backtrace command's
1177 "full/no-filters/hide" qualifiers.
1179 * In settings, you can now abbreviate "unlimited".
1181 E.g., "set print elements u" is now equivalent to "set print
1182 elements unlimited".
1187 This lists all the possible completions for the rest of the line, if it
1188 were to be given as a command itself. This is intended for use by MI
1189 frontends in cases when separate CLI and MI channels cannot be used.
1191 -catch-throw, -catch-rethrow, and -catch-catch
1192 These can be used to catch C++ exceptions in a similar fashion to
1193 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1195 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1196 These commands are the MI equivalent of the CLI commands 'info
1197 functions', 'info types', and 'info variables' respectively.
1199 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1202 -symbol-info-module-functions and -symbol-info-module-variables.
1203 These commands are the MI equivalent of the CLI commands 'info
1204 module functions' and 'info module variables'.
1208 ** The default version of the MI interpreter is now 3 (-i=mi3).
1210 ** The output of information about multi-location breakpoints (which is
1211 syntactically incorrect in MI 2) has changed in MI 3. This affects
1212 the following commands and events:
1216 - =breakpoint-created
1217 - =breakpoint-modified
1219 The -fix-multi-location-breakpoint-output command can be used to enable
1220 this behavior with previous MI versions.
1222 ** Backtraces and frames include a new optional field addr_flags which is
1223 given after the addr field. On AArch64 this contains PAC if the address
1224 has been masked in the frame. On all other targets the field is not
1229 The testsuite now creates the files gdb.cmd (containing the arguments
1230 used to launch GDB) and gdb.in (containing all the commands sent to
1231 GDB) in the output directory for each test script. Multiple invocations
1232 are appended with .1, .2, .3 etc.
1234 * Building GDB and GDBserver now requires GNU make >= 3.82.
1236 Using another implementation of the make program or an earlier version of
1237 GNU make to build GDB or GDBserver is not supported.
1239 * Building GDB now requires GNU readline >= 7.0.
1241 GDB now bundles GNU readline 8.0, but if you choose to use
1242 --with-system-readline, only readline >= 7.0 can be used.
1244 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1245 from .inputrc to bind keys in this keymap. This feature is only
1246 available when gdb is built against GNU readline 8.0 or later.
1248 * Removed targets and native configurations
1250 GDB no longer supports debugging the Cell Broadband Engine. This includes
1251 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1252 of Cell/B.E. applications that use both the PPU and SPU architectures.
1258 * Removed targets and native configurations
1260 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1261 sparc*-*-solaris2.10
1263 *** Changes in GDB 8.3
1265 * GDB and GDBserver now support access to additional registers on
1266 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1269 * GDB now has experimental support for the compilation and injection of
1270 C++ source code into the inferior. This beta release does not include
1271 support for several language features, such as templates, constructors,
1274 This feature requires GCC 7.1 or higher built with libcp1.so
1277 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1278 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1279 'ADDRESS:PORT' method.
1281 * DWARF index cache: GDB can now automatically save indices of DWARF
1282 symbols on disk to speed up further loading of the same binaries.
1284 * Ada task switching is now supported on aarch64-elf targets when
1285 debugging a program using the Ravenscar Profile. For more information,
1286 see the "Tasking Support when using the Ravenscar Profile" section
1287 in the GDB user manual.
1289 * GDB in batch mode now exits with status 1 if the last command to be
1292 * The RISC-V target now supports target descriptions.
1294 * System call catchpoints now support system call aliases on FreeBSD.
1295 When the ABI of a system call changes in FreeBSD, this is
1296 implemented by leaving a compatibility system call using the old ABI
1297 at the existing number and allocating a new system call number for
1298 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1299 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1300 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1301 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1302 so that a system call catchpoint for the 'kevent' system call will
1303 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1304 binaries. This ensures that 'kevent' system calls are caught for
1305 binaries using either the old or new ABIs.
1307 * Terminal styling is now available for the CLI and the TUI. GNU
1308 Source Highlight can additionally be used to provide styling of
1309 source code snippets. See the "set style" commands, below, for more
1312 * Removed support for old demangling styles arm, edg, gnu, hp and
1317 set debug compile-cplus-types
1318 show debug compile-cplus-types
1319 Control the display of debug output about type conversion in the
1320 C++ compile feature. Commands have no effect while compiling
1321 for other languages.
1325 Control whether debug output about files/functions skipping is
1328 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1329 Apply a command to some frames.
1330 FLAG arguments allow to control what output to produce and how to handle
1331 errors raised when applying COMMAND to a frame.
1334 Apply a command to all threads (ignoring errors and empty output).
1335 Shortcut for 'thread apply all -s COMMAND'.
1338 Apply a command to all frames (ignoring errors and empty output).
1339 Shortcut for 'frame apply all -s COMMAND'.
1342 Apply a command to all frames of all threads (ignoring errors and empty
1344 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1346 maint set dwarf unwinders (on|off)
1347 maint show dwarf unwinders
1348 Control whether DWARF unwinders can be used.
1351 Display a list of open files for a process.
1355 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1356 These commands all now take a frame specification which
1357 is either a frame level, or one of the keywords 'level', 'address',
1358 'function', or 'view' followed by a parameter. Selecting a frame by
1359 address, or viewing a frame outside the current backtrace now
1360 requires the use of a keyword. Selecting a frame by level is
1361 unchanged. The MI comment "-stack-select-frame" is unchanged.
1363 target remote FILENAME
1364 target extended-remote FILENAME
1365 If FILENAME is a Unix domain socket, GDB will attempt to connect
1366 to this socket instead of opening FILENAME as a character device.
1368 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1369 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1370 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1371 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1372 These commands can now print only the searched entities
1373 matching the provided regexp(s), giving a condition
1374 on the entity names or entity types. The flag -q disables
1375 printing headers or informations messages.
1381 These commands now determine the syntax for the shown entities
1382 according to the language chosen by `set language'. In particular,
1383 `set language auto' means to automatically choose the language of
1386 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1387 The 'thread apply' command accepts new FLAG arguments.
1388 FLAG arguments allow to control what output to produce and how to handle
1389 errors raised when applying COMMAND to a thread.
1391 set tui tab-width NCHARS
1392 show tui tab-width NCHARS
1393 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1395 set style enabled [on|off]
1397 Enable or disable terminal styling. Styling is enabled by default
1398 on most hosts, but disabled by default when in batch mode.
1400 set style sources [on|off]
1402 Enable or disable source code styling. Source code styling is
1403 enabled by default, but only takes effect if styling in general is
1404 enabled, and if GDB was linked with GNU Source Highlight.
1406 set style filename foreground COLOR
1407 set style filename background COLOR
1408 set style filename intensity VALUE
1409 Control the styling of file names.
1411 set style function foreground COLOR
1412 set style function background COLOR
1413 set style function intensity VALUE
1414 Control the styling of function names.
1416 set style variable foreground COLOR
1417 set style variable background COLOR
1418 set style variable intensity VALUE
1419 Control the styling of variable names.
1421 set style address foreground COLOR
1422 set style address background COLOR
1423 set style address intensity VALUE
1424 Control the styling of addresses.
1428 ** The '-data-disassemble' MI command now accepts an '-a' option to
1429 disassemble the whole function surrounding the given program
1430 counter value or function name. Support for this feature can be
1431 verified by using the "-list-features" command, which should
1432 contain "data-disassemble-a-option".
1434 ** Command responses and notifications that include a frame now include
1435 the frame's architecture in a new "arch" attribute.
1437 * New native configurations
1439 GNU/Linux/RISC-V riscv*-*-linux*
1440 FreeBSD/riscv riscv*-*-freebsd*
1444 GNU/Linux/RISC-V riscv*-*-linux*
1445 CSKY ELF csky*-*-elf
1446 CSKY GNU/LINUX csky*-*-linux
1447 FreeBSD/riscv riscv*-*-freebsd*
1449 GNU/Linux/OpenRISC or1k*-*-linux*
1453 GDB no longer supports native debugging on versions of MS-Windows
1458 ** GDB no longer supports Python versions less than 2.6.
1460 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1461 space associated to that inferior.
1463 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1464 of objfiles associated to that program space.
1466 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1467 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1470 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1471 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1472 correct and did not work properly.
1474 ** The gdb.Value type has a new constructor, which is used to construct a
1475 gdb.Value from a Python buffer object and a gdb.Type.
1481 Enable or disable the undefined behavior sanitizer. This is
1482 disabled by default, but passing --enable-ubsan=yes or
1483 --enable-ubsan=auto to configure will enable it. Enabling this can
1484 cause a performance penalty. The undefined behavior sanitizer was
1485 first introduced in GCC 4.9.
1487 *** Changes in GDB 8.2
1489 * The 'set disassembler-options' command now supports specifying options
1490 for the MIPS target.
1492 * The 'symbol-file' command now accepts an '-o' option to add a relative
1493 offset to all sections.
1495 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1496 a relative offset to all sections, but it allows to override the load
1497 address of individual sections using '-s'.
1499 * The 'add-symbol-file' command no longer requires the second argument
1500 (address of the text section).
1502 * The endianness used with the 'set endian auto' mode in the absence of
1503 an executable selected for debugging is now the last endianness chosen
1504 either by one of the 'set endian big' and 'set endian little' commands
1505 or by inferring from the last executable used, rather than the startup
1508 * The pager now allows a "c" response, meaning to disable the pager
1509 for the rest of the current command.
1511 * The commands 'info variables/functions/types' now show the source line
1512 numbers of symbol definitions when available.
1514 * 'info proc' now works on running processes on FreeBSD systems and core
1515 files created on FreeBSD systems.
1517 * C expressions can now use _Alignof, and C++ expressions can now use
1520 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1521 the vector length while the process is running.
1527 Control display of debugging info regarding the FreeBSD native target.
1529 set|show varsize-limit
1530 This new setting allows the user to control the maximum size of Ada
1531 objects being printed when those objects have a variable type,
1532 instead of that maximum size being hardcoded to 65536 bytes.
1534 set|show record btrace cpu
1535 Controls the processor to be used for enabling errata workarounds for
1536 branch trace decode.
1538 maint check libthread-db
1539 Run integrity checks on the current inferior's thread debugging
1542 maint set check-libthread-db (on|off)
1543 maint show check-libthread-db
1544 Control whether to run integrity checks on inferior specific thread
1545 debugging libraries as they are loaded. The default is not to
1546 perform such checks.
1550 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1552 ** The commands attached to a breakpoint can be set by assigning to
1553 the breakpoint's "commands" field.
1555 ** gdb.execute can now execute multi-line gdb commands.
1557 ** The new functions gdb.convenience_variable and
1558 gdb.set_convenience_variable can be used to get and set the value
1559 of convenience variables.
1561 ** A gdb.Parameter will no longer print the "set" help text on an
1562 ordinary "set"; instead by default a "set" will be silent unless
1563 the get_set_string method returns a non-empty string.
1567 RiscV ELF riscv*-*-elf
1569 * Removed targets and native configurations
1571 m88k running OpenBSD m88*-*-openbsd*
1572 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1573 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1574 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1576 * Aarch64/Linux hardware watchpoints improvements
1578 Hardware watchpoints on unaligned addresses are now properly
1579 supported when running Linux kernel 4.10 or higher: read and access
1580 watchpoints are no longer spuriously missed, and all watchpoints
1581 lengths between 1 and 8 bytes are supported. On older kernels,
1582 watchpoints set on unaligned addresses are no longer missed, with
1583 the tradeoff that there is a possibility of false hits being
1588 --enable-codesign=CERT
1589 This can be used to invoke "codesign -s CERT" after building gdb.
1590 This option is useful on macOS, where code signing is required for
1591 gdb to work properly.
1593 --disable-gdbcli has been removed
1594 This is now silently accepted, but does nothing.
1596 *** Changes in GDB 8.1
1598 * GDB now supports dynamically creating arbitrary register groups specified
1599 in XML target descriptions. This allows for finer grain grouping of
1600 registers on systems with a large amount of registers.
1602 * The 'ptype' command now accepts a '/o' flag, which prints the
1603 offsets and sizes of fields in a struct, like the pahole(1) tool.
1605 * New "--readnever" command line option instructs GDB to not read each
1606 symbol file's symbolic debug information. This makes startup faster
1607 but at the expense of not being able to perform symbolic debugging.
1608 This option is intended for use cases where symbolic debugging will
1609 not be used, e.g., when you only need to dump the debuggee's core.
1611 * GDB now uses the GNU MPFR library, if available, to emulate target
1612 floating-point arithmetic during expression evaluation when the target
1613 uses different floating-point formats than the host. At least version
1614 3.1 of GNU MPFR is required.
1616 * GDB now supports access to the guarded-storage-control registers and the
1617 software-based guarded-storage broadcast control registers on IBM z14.
1619 * On Unix systems, GDB now supports transmitting environment variables
1620 that are to be set or unset to GDBserver. These variables will
1621 affect the environment to be passed to the remote inferior.
1623 To inform GDB of environment variables that are to be transmitted to
1624 GDBserver, use the "set environment" command. Only user set
1625 environment variables are sent to GDBserver.
1627 To inform GDB of environment variables that are to be unset before
1628 the remote inferior is started by the GDBserver, use the "unset
1629 environment" command.
1631 * Completion improvements
1633 ** GDB can now complete function parameters in linespecs and
1634 explicit locations without quoting. When setting breakpoints,
1635 quoting around functions names to help with TAB-completion is
1636 generally no longer necessary. For example, this now completes
1639 (gdb) b function(in[TAB]
1640 (gdb) b function(int)
1642 Related, GDB is no longer confused with completing functions in
1643 C++ anonymous namespaces:
1646 (gdb) b (anonymous namespace)::[TAB][TAB]
1647 (anonymous namespace)::a_function()
1648 (anonymous namespace)::b_function()
1650 ** GDB now has much improved linespec and explicit locations TAB
1651 completion support, that better understands what you're
1652 completing and offers better suggestions. For example, GDB no
1653 longer offers data symbols as possible completions when you're
1654 setting a breakpoint.
1656 ** GDB now TAB-completes label symbol names.
1658 ** The "complete" command now mimics TAB completion accurately.
1660 * New command line options (gcore)
1663 Dump all memory mappings.
1665 * Breakpoints on C++ functions are now set on all scopes by default
1667 By default, breakpoints on functions/methods are now interpreted as
1668 specifying all functions with the given name ignoring missing
1669 leading scopes (namespaces and classes).
1671 For example, assuming a C++ program with symbols named:
1676 both commands "break func()" and "break B::func()" set a breakpoint
1679 You can use the new flag "-qualified" to override this. This makes
1680 GDB interpret the specified function name as a complete
1681 fully-qualified name instead. For example, using the same C++
1682 program, the "break -q B::func" command sets a breakpoint on
1683 "B::func", only. A parameter has been added to the Python
1684 gdb.Breakpoint constructor to achieve the same result when creating
1685 a breakpoint from Python.
1687 * Breakpoints on functions marked with C++ ABI tags
1689 GDB can now set breakpoints on functions marked with C++ ABI tags
1690 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1691 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1693 Functions with a C++11 abi tag are demangled/displayed like this:
1695 function[abi:cxx11](int)
1698 You can now set a breakpoint on such functions simply as if they had
1701 (gdb) b function(int)
1703 Or if you need to disambiguate between tags, like:
1705 (gdb) b function[abi:other_tag](int)
1707 Tab completion was adjusted accordingly as well.
1711 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1712 gdb.new_thread are emitted. See the manual for further
1713 description of these.
1715 ** A new function, "gdb.rbreak" has been added to the Python API.
1716 This function allows the setting of a large number of breakpoints
1717 via a regex pattern in Python. See the manual for further details.
1719 ** Python breakpoints can now accept explicit locations. See the
1720 manual for a further description of this feature.
1723 * New features in the GDB remote stub, GDBserver
1725 ** GDBserver is now able to start inferior processes with a
1726 specified initial working directory.
1728 The user can set the desired working directory to be used from
1729 GDB using the new "set cwd" command.
1731 ** New "--selftest" command line option runs some GDBserver self
1732 tests. These self tests are disabled in releases.
1734 ** On Unix systems, GDBserver now does globbing expansion and variable
1735 substitution in inferior command line arguments.
1737 This is done by starting inferiors using a shell, like GDB does.
1738 See "set startup-with-shell" in the user manual for how to disable
1739 this from GDB when using "target extended-remote". When using
1740 "target remote", you can disable the startup with shell by using the
1741 new "--no-startup-with-shell" GDBserver command line option.
1743 ** On Unix systems, GDBserver now supports receiving environment
1744 variables that are to be set or unset from GDB. These variables
1745 will affect the environment to be passed to the inferior.
1747 * When catching an Ada exception raised with a message, GDB now prints
1748 the message in the catchpoint hit notification. In GDB/MI mode, that
1749 information is provided as an extra field named "exception-message"
1750 in the *stopped notification.
1752 * Trait objects can now be inspected When debugging Rust code. This
1753 requires compiler support which will appear in Rust 1.24.
1755 * New remote packets
1757 QEnvironmentHexEncoded
1758 Inform GDBserver of an environment variable that is to be passed to
1759 the inferior when starting it.
1762 Inform GDBserver of an environment variable that is to be unset
1763 before starting the remote inferior.
1766 Inform GDBserver that the environment should be reset (i.e.,
1767 user-set environment variables should be unset).
1770 Indicates whether the inferior must be started with a shell or not.
1773 Tell GDBserver that the inferior to be started should use a specific
1776 * The "maintenance print c-tdesc" command now takes an optional
1777 argument which is the file name of XML target description.
1779 * The "maintenance selftest" command now takes an optional argument to
1780 filter the tests to be run.
1782 * The "enable", and "disable" commands now accept a range of
1783 breakpoint locations, e.g. "enable 1.3-5".
1788 Set and show the current working directory for the inferior.
1790 set|show compile-gcc
1791 Set and show compilation command used for compiling and injecting code
1792 with the 'compile' commands.
1794 set debug separate-debug-file
1795 show debug separate-debug-file
1796 Control the display of debug output about separate debug file search.
1798 set dump-excluded-mappings
1799 show dump-excluded-mappings
1800 Control whether mappings marked with the VM_DONTDUMP flag should be
1801 dumped when generating a core file.
1803 maint info selftests
1804 List the registered selftests.
1807 Start the debugged program stopping at the first instruction.
1810 Control display of debugging messages related to OpenRISC targets.
1812 set|show print type nested-type-limit
1813 Set and show the limit of nesting level for nested types that the
1814 type printer will show.
1816 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1819 * Safer/improved support for debugging with no debug info
1821 GDB no longer assumes functions with no debug information return
1824 This means that GDB now refuses to call such functions unless you
1825 tell it the function's type, by either casting the call to the
1826 declared return type, or by casting the function to a function
1827 pointer of the right type, and calling that:
1829 (gdb) p getenv ("PATH")
1830 'getenv' has unknown return type; cast the call to its declared return type
1831 (gdb) p (char *) getenv ("PATH")
1832 $1 = 0x7fffffffe "/usr/local/bin:/"...
1833 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1834 $2 = 0x7fffffffe "/usr/local/bin:/"...
1836 Similarly, GDB no longer assumes that global variables with no debug
1837 info have type 'int', and refuses to print the variable's value
1838 unless you tell it the variable's type:
1841 'var' has unknown type; cast it to its declared type
1845 * New native configurations
1847 FreeBSD/aarch64 aarch64*-*-freebsd*
1848 FreeBSD/arm arm*-*-freebsd*
1852 FreeBSD/aarch64 aarch64*-*-freebsd*
1853 FreeBSD/arm arm*-*-freebsd*
1854 OpenRISC ELF or1k*-*-elf
1856 * Removed targets and native configurations
1858 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1860 *** Changes in GDB 8.0
1862 * GDB now supports access to the PKU register on GNU/Linux. The register is
1863 added by the Memory Protection Keys for Userspace feature which will be
1864 available in future Intel CPUs.
1866 * GDB now supports C++11 rvalue references.
1870 ** New functions to start, stop and access a running btrace recording.
1871 ** Rvalue references are now supported in gdb.Type.
1873 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1876 * Building GDB and GDBserver now requires a C++11 compiler.
1878 For example, GCC 4.8 or later.
1880 It is no longer possible to build GDB or GDBserver with a C
1881 compiler. The --disable-build-with-cxx configure option has been
1884 * Building GDB and GDBserver now requires GNU make >= 3.81.
1886 It is no longer supported to build GDB or GDBserver with another
1887 implementation of the make program or an earlier version of GNU make.
1889 * Native debugging on MS-Windows supports command-line redirection
1891 Command-line arguments used for starting programs on MS-Windows can
1892 now include redirection symbols supported by native Windows shells,
1893 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1894 as "run", "start", and "set args", as well as the corresponding MI
1897 * Support for thread names on MS-Windows.
1899 GDB now catches and handles the special exception that programs
1900 running on MS-Windows use to assign names to threads in the
1903 * Support for Java programs compiled with gcj has been removed.
1905 * User commands now accept an unlimited number of arguments.
1906 Previously, only up to 10 was accepted.
1908 * The "eval" command now expands user-defined command arguments.
1910 This makes it easier to process a variable number of arguments:
1915 eval "print $arg%d", $i
1920 * Target descriptions can now describe registers for sparc32 and sparc64.
1922 * GDB now supports DWARF version 5 (debug information format).
1923 Its .debug_names index is not yet supported.
1925 * New native configurations
1927 FreeBSD/mips mips*-*-freebsd
1931 Synopsys ARC arc*-*-elf32
1932 FreeBSD/mips mips*-*-freebsd
1934 * Removed targets and native configurations
1936 Alpha running FreeBSD alpha*-*-freebsd*
1937 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1942 Erases all the flash memory regions reported by the target.
1944 maint print arc arc-instruction address
1945 Print internal disassembler information about instruction at a given address.
1949 set disassembler-options
1950 show disassembler-options
1951 Controls the passing of target specific information to the disassembler.
1952 If it is necessary to specify more than one disassembler option then
1953 multiple options can be placed together into a comma separated list.
1954 The default value is the empty string. Currently, the only supported
1955 targets are ARM, PowerPC and S/390.
1960 Erases all the flash memory regions reported by the target. This is
1961 equivalent to the CLI command flash-erase.
1963 -file-list-shared-libraries
1964 List the shared libraries in the program. This is
1965 equivalent to the CLI command "info shared".
1968 Catchpoints stopping the program when Ada exceptions are
1969 handled. This is equivalent to the CLI command "catch handlers".
1971 *** Changes in GDB 7.12
1973 * GDB and GDBserver now build with a C++ compiler by default.
1975 The --enable-build-with-cxx configure option is now enabled by
1976 default. One must now explicitly configure with
1977 --disable-build-with-cxx in order to build with a C compiler. This
1978 option will be removed in a future release.
1980 * GDBserver now supports recording btrace without maintaining an active
1983 * GDB now supports a negative repeat count in the 'x' command to examine
1984 memory backward from the given address. For example:
1987 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1988 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1989 (gdb) x/-5i 0x0000000000400580
1990 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1991 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1992 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1993 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1994 0x40057b <main(int, char**)+25>:
1995 callq 0x400536 <Func1(int, char const*)>
1997 * Fortran: Support structures with fields of dynamic types and
1998 arrays of dynamic types.
2000 * The symbol dumping maintenance commands have new syntax.
2001 maint print symbols [-pc address] [--] [filename]
2002 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2003 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2004 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2005 maint print msymbols [-objfile objfile] [--] [filename]
2007 * GDB now supports multibit bitfields and enums in target register
2010 * New Python-based convenience function $_as_string(val), which returns
2011 the textual representation of a value. This function is especially
2012 useful to obtain the text label of an enum value.
2014 * Intel MPX bound violation handling.
2016 Segmentation faults caused by a Intel MPX boundary violation
2017 now display the kind of violation (upper or lower), the memory
2018 address accessed and the memory bounds, along with the usual
2019 signal received and code location.
2023 Program received signal SIGSEGV, Segmentation fault
2024 Upper bound violation while accessing address 0x7fffffffc3b3
2025 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2026 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2028 * Rust language support.
2029 GDB now supports debugging programs written in the Rust programming
2030 language. See https://www.rust-lang.org/ for more information about
2033 * Support for running interpreters on specified input/output devices
2035 GDB now supports a new mechanism that allows frontends to provide
2036 fully featured GDB console views, as a better alternative to
2037 building such views on top of the "-interpreter-exec console"
2038 command. See the new "new-ui" command below. With that command,
2039 frontends can now start GDB in the traditional command-line mode
2040 running in an embedded terminal emulator widget, and create a
2041 separate MI interpreter running on a specified i/o device. In this
2042 way, GDB handles line editing, history, tab completion, etc. in the
2043 console all by itself, and the GUI uses the separate MI interpreter
2044 for its own control and synchronization, invisible to the command
2047 * The "catch syscall" command catches groups of related syscalls.
2049 The "catch syscall" command now supports catching a group of related
2050 syscalls using the 'group:' or 'g:' prefix.
2055 skip -gfile file-glob-pattern
2056 skip -function function
2057 skip -rfunction regular-expression
2058 A generalized form of the skip command, with new support for
2059 glob-style file names and regular expressions for function names.
2060 Additionally, a file spec and a function spec may now be combined.
2062 maint info line-table REGEXP
2063 Display the contents of GDB's internal line table data structure.
2066 Run any GDB unit tests that were compiled in.
2069 Start a new user interface instance running INTERP as interpreter,
2070 using the TTY file for input/output.
2074 ** gdb.Breakpoint objects have a new attribute "pending", which
2075 indicates whether the breakpoint is pending.
2076 ** Three new breakpoint-related events have been added:
2077 gdb.breakpoint_created, gdb.breakpoint_modified, and
2078 gdb.breakpoint_deleted.
2080 signal-event EVENTID
2081 Signal ("set") the given MS-Windows event object. This is used in
2082 conjunction with the Windows JIT debugging (AeDebug) support, where
2083 the OS suspends a crashing process until a debugger can attach to
2084 it. Resuming the crashing process, in order to debug it, is done by
2085 signalling an event.
2087 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2088 was added in GDBserver, including JIT compiling fast tracepoint's
2089 conditional expression bytecode into native code.
2091 * Support for various remote target protocols and ROM monitors has
2094 target m32rsdi Remote M32R debugging over SDI
2095 target mips MIPS remote debugging protocol
2096 target pmon PMON ROM monitor
2097 target ddb NEC's DDB variant of PMON for Vr4300
2098 target rockhopper NEC RockHopper variant of PMON
2099 target lsi LSI variant of PMO
2101 * Support for tracepoints and fast tracepoints on powerpc-linux,
2102 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2103 including JIT compiling fast tracepoint's conditional expression
2104 bytecode into native code.
2106 * MI async record =record-started now includes the method and format used for
2107 recording. For example:
2109 =record-started,thread-group="i1",method="btrace",format="bts"
2111 * MI async record =thread-selected now includes the frame field. For example:
2113 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2117 Andes NDS32 nds32*-*-elf
2119 *** Changes in GDB 7.11
2121 * GDB now supports debugging kernel-based threads on FreeBSD.
2123 * Per-inferior thread numbers
2125 Thread numbers are now per inferior instead of global. If you're
2126 debugging multiple inferiors, GDB displays thread IDs using a
2127 qualified INF_NUM.THR_NUM form. For example:
2131 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2132 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2133 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2134 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2136 As consequence, thread numbers as visible in the $_thread
2137 convenience variable and in Python's InferiorThread.num attribute
2138 are no longer unique between inferiors.
2140 GDB now maintains a second thread ID per thread, referred to as the
2141 global thread ID, which is the new equivalent of thread numbers in
2142 previous releases. See also $_gthread below.
2144 For backwards compatibility, MI's thread IDs always refer to global
2147 * Commands that accept thread IDs now accept the qualified
2148 INF_NUM.THR_NUM form as well. For example:
2151 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2154 * In commands that accept a list of thread IDs, you can now refer to
2155 all threads of an inferior using a star wildcard. GDB accepts
2156 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2157 refer to all threads of the current inferior. For example, "info
2160 * You can use "info threads -gid" to display the global thread ID of
2163 * The new convenience variable $_gthread holds the global number of
2166 * The new convenience variable $_inferior holds the number of the
2169 * GDB now displays the ID and name of the thread that hit a breakpoint
2170 or received a signal, if your program is multi-threaded. For
2173 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2174 Thread 1 "main" received signal SIGINT, Interrupt.
2176 * Record btrace now supports non-stop mode.
2178 * Support for tracepoints on aarch64-linux was added in GDBserver.
2180 * The 'record instruction-history' command now indicates speculative execution
2181 when using the Intel Processor Trace recording format.
2183 * GDB now allows users to specify explicit locations, bypassing
2184 the linespec parser. This feature is also available to GDB/MI
2187 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2188 GDB now is able to debug both AArch64 applications and ARM applications
2191 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2192 including JIT compiling fast tracepoint's conditional expression bytecode
2195 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2197 * "info threads", "info inferiors", "info display", "info checkpoints"
2198 and "maint info program-spaces" now list the corresponding items in
2199 ascending ID order, for consistency with all other "info" commands.
2201 * In Ada, the overloads selection menu has been enhanced to display the
2202 parameter types and the return types for the matching overloaded subprograms.
2206 maint set target-non-stop (on|off|auto)
2207 maint show target-non-stop
2208 Control whether GDB targets always operate in non-stop mode even if
2209 "set non-stop" is "off". The default is "auto", meaning non-stop
2210 mode is enabled if supported by the target.
2212 maint set bfd-sharing
2213 maint show bfd-sharing
2214 Control the reuse of bfd objects.
2217 show debug bfd-cache
2218 Control display of debugging info regarding bfd caching.
2222 Control display of debugging info regarding FreeBSD threads.
2224 set remote multiprocess-extensions-packet
2225 show remote multiprocess-extensions-packet
2226 Set/show the use of the remote protocol multiprocess extensions.
2228 set remote thread-events
2229 show remote thread-events
2230 Set/show the use of thread create/exit events.
2232 set ada print-signatures on|off
2233 show ada print-signatures"
2234 Control whether parameter types and return types are displayed in overloads
2235 selection menus. It is activated (@code{on}) by default.
2239 Controls the maximum size of memory, in bytes, that GDB will
2240 allocate for value contents. Prevents incorrect programs from
2241 causing GDB to allocate overly large buffers. Default is 64k.
2243 * The "disassemble" command accepts a new modifier: /s.
2244 It prints mixed source+disassembly like /m with two differences:
2245 - disassembled instructions are now printed in program order, and
2246 - and source for all relevant files is now printed.
2247 The "/m" option is now considered deprecated: its "source-centric"
2248 output hasn't proved useful in practice.
2250 * The "record instruction-history" command accepts a new modifier: /s.
2251 It behaves exactly like /m and prints mixed source+disassembly.
2253 * The "set scheduler-locking" command supports a new mode "replay".
2254 It behaves like "off" in record mode and like "on" in replay mode.
2256 * Support for various ROM monitors has been removed:
2258 target dbug dBUG ROM monitor for Motorola ColdFire
2259 target picobug Motorola picobug monitor
2260 target dink32 DINK32 ROM monitor for PowerPC
2261 target m32r Renesas M32R/D ROM monitor
2262 target mon2000 mon2000 ROM monitor
2263 target ppcbug PPCBUG ROM monitor for PowerPC
2265 * Support for reading/writing memory and extracting values on architectures
2266 whose memory is addressable in units of any integral multiple of 8 bits.
2269 Allows to break when an Ada exception is handled.
2271 * New remote packets
2274 Indicates that an exec system call was executed.
2276 exec-events feature in qSupported
2277 The qSupported packet allows GDB to request support for exec
2278 events using the new 'gdbfeature' exec-event, and the qSupported
2279 response can contain the corresponding 'stubfeature'. Set and
2280 show commands can be used to display whether these features are enabled.
2283 Equivalent to interrupting with the ^C character, but works in
2286 thread created stop reason (T05 create:...)
2287 Indicates that the thread was just created and is stopped at entry.
2289 thread exit stop reply (w exitcode;tid)
2290 Indicates that the thread has terminated.
2293 Enables/disables thread create and exit event reporting. For
2294 example, this is used in non-stop mode when GDB stops a set of
2295 threads and synchronously waits for the their corresponding stop
2296 replies. Without exit events, if one of the threads exits, GDB
2297 would hang forever not knowing that it should no longer expect a
2298 stop for that same thread.
2301 Indicates that there are no resumed threads left in the target (all
2302 threads are stopped). The remote stub reports support for this stop
2303 reply to GDB's qSupported query.
2306 Enables/disables catching syscalls from the inferior process.
2307 The remote stub reports support for this packet to GDB's qSupported query.
2309 syscall_entry stop reason
2310 Indicates that a syscall was just called.
2312 syscall_return stop reason
2313 Indicates that a syscall just returned.
2315 * Extended-remote exec events
2317 ** GDB now has support for exec events on extended-remote Linux targets.
2318 For such targets with Linux kernels 2.5.46 and later, this enables
2319 follow-exec-mode and exec catchpoints.
2321 set remote exec-event-feature-packet
2322 show remote exec-event-feature-packet
2323 Set/show the use of the remote exec event feature.
2325 * Thread names in remote protocol
2327 The reply to qXfer:threads:read may now include a name attribute for each
2330 * Target remote mode fork and exec events
2332 ** GDB now has support for fork and exec events on target remote mode
2333 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2334 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2335 fork and exec catchpoints.
2337 * Remote syscall events
2339 ** GDB now has support for catch syscall on remote Linux targets,
2340 currently enabled on x86/x86_64 architectures.
2342 set remote catch-syscall-packet
2343 show remote catch-syscall-packet
2344 Set/show the use of the remote catch syscall feature.
2348 ** The -var-set-format command now accepts the zero-hexadecimal
2349 format. It outputs data in hexadecimal format with zero-padding on the
2354 ** gdb.InferiorThread objects have a new attribute "global_num",
2355 which refers to the thread's global thread ID. The existing
2356 "num" attribute now refers to the thread's per-inferior number.
2357 See "Per-inferior thread numbers" above.
2358 ** gdb.InferiorThread objects have a new attribute "inferior", which
2359 is the Inferior object the thread belongs to.
2361 *** Changes in GDB 7.10
2363 * Support for process record-replay and reverse debugging on aarch64*-linux*
2364 targets has been added. GDB now supports recording of A64 instruction set
2365 including advance SIMD instructions.
2367 * Support for Sun's version of the "stabs" debug file format has been removed.
2369 * GDB now honors the content of the file /proc/PID/coredump_filter
2370 (PID is the process ID) on GNU/Linux systems. This file can be used
2371 to specify the types of memory mappings that will be included in a
2372 corefile. For more information, please refer to the manual page of
2373 "core(5)". GDB also has a new command: "set use-coredump-filter
2374 on|off". It allows to set whether GDB will read the content of the
2375 /proc/PID/coredump_filter file when generating a corefile.
2377 * The "info os" command on GNU/Linux can now display information on
2379 "info os cpus" Listing of all cpus/cores on the system
2381 * GDB has two new commands: "set serial parity odd|even|none" and
2382 "show serial parity". These allows to set or show parity for the
2385 * The "info source" command now displays the producer string if it was
2386 present in the debug info. This typically includes the compiler version
2387 and may include things like its command line arguments.
2389 * The "info dll", an alias of the "info sharedlibrary" command,
2390 is now available on all platforms.
2392 * Directory names supplied to the "set sysroot" commands may be
2393 prefixed with "target:" to tell GDB to access shared libraries from
2394 the target system, be it local or remote. This replaces the prefix
2395 "remote:". The default sysroot has been changed from "" to
2396 "target:". "remote:" is automatically converted to "target:" for
2397 backward compatibility.
2399 * The system root specified by "set sysroot" will be prepended to the
2400 filename of the main executable (if reported to GDB as absolute by
2401 the operating system) when starting processes remotely, and when
2402 attaching to already-running local or remote processes.
2404 * GDB now supports automatic location and retrieval of executable
2405 files from remote targets. Remote debugging can now be initiated
2406 using only a "target remote" or "target extended-remote" command
2407 (no "set sysroot" or "file" commands are required). See "New remote
2410 * The "dump" command now supports verilog hex format.
2412 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2414 * On GNU/Linux, GDB and gdbserver are now able to access executable
2415 and shared library files without a "set sysroot" command when
2416 attaching to processes running in different mount namespaces from
2417 the debugger. This makes it possible to attach to processes in
2418 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2419 See "New remote packets" below.
2421 * The "tui reg" command now provides completion for all of the
2422 available register groups, including target specific groups.
2424 * The HISTSIZE environment variable is no longer read when determining
2425 the size of GDB's command history. GDB now instead reads the dedicated
2426 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2427 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2432 ** Memory ports can now be unbuffered.
2436 ** gdb.Objfile objects have a new attribute "username",
2437 which is the name of the objfile as specified by the user,
2438 without, for example, resolving symlinks.
2439 ** You can now write frame unwinders in Python.
2440 ** gdb.Type objects have a new method "optimized_out",
2441 returning optimized out gdb.Value instance of this type.
2442 ** gdb.Value objects have new methods "reference_value" and
2443 "const_value" which return a reference to the value and a
2444 "const" version of the value respectively.
2448 maint print symbol-cache
2449 Print the contents of the symbol cache.
2451 maint print symbol-cache-statistics
2452 Print statistics of symbol cache usage.
2454 maint flush-symbol-cache
2455 Flush the contents of the symbol cache.
2459 Start branch trace recording using Branch Trace Store (BTS) format.
2462 Evaluate expression by using the compiler and print result.
2466 Explicit commands for enabling and disabling tui mode.
2469 set mpx bound on i386 and amd64
2470 Support for bound table investigation on Intel MPX enabled applications.
2474 Start branch trace recording using Intel Processor Trace format.
2477 Print information about branch tracing internals.
2479 maint btrace packet-history
2480 Print the raw branch tracing data.
2482 maint btrace clear-packet-history
2483 Discard the stored raw branch tracing data.
2486 Discard all branch tracing data. It will be fetched and processed
2487 anew by the next "record" command.
2492 Renamed from "set debug dwarf2-die".
2493 show debug dwarf-die
2494 Renamed from "show debug dwarf2-die".
2496 set debug dwarf-read
2497 Renamed from "set debug dwarf2-read".
2498 show debug dwarf-read
2499 Renamed from "show debug dwarf2-read".
2501 maint set dwarf always-disassemble
2502 Renamed from "maint set dwarf2 always-disassemble".
2503 maint show dwarf always-disassemble
2504 Renamed from "maint show dwarf2 always-disassemble".
2506 maint set dwarf max-cache-age
2507 Renamed from "maint set dwarf2 max-cache-age".
2508 maint show dwarf max-cache-age
2509 Renamed from "maint show dwarf2 max-cache-age".
2511 set debug dwarf-line
2512 show debug dwarf-line
2513 Control display of debugging info regarding DWARF line processing.
2516 show max-completions
2517 Set the maximum number of candidates to be considered during
2518 completion. The default value is 200. This limit allows GDB
2519 to avoid generating large completion lists, the computation of
2520 which can cause the debugger to become temporarily unresponsive.
2522 set history remove-duplicates
2523 show history remove-duplicates
2524 Control the removal of duplicate history entries.
2526 maint set symbol-cache-size
2527 maint show symbol-cache-size
2528 Control the size of the symbol cache.
2530 set|show record btrace bts buffer-size
2531 Set and show the size of the ring buffer used for branch tracing in
2533 The obtained size may differ from the requested size. Use "info
2534 record" to see the obtained buffer size.
2536 set debug linux-namespaces
2537 show debug linux-namespaces
2538 Control display of debugging info regarding Linux namespaces.
2540 set|show record btrace pt buffer-size
2541 Set and show the size of the ring buffer used for branch tracing in
2542 Intel Processor Trace format.
2543 The obtained size may differ from the requested size. Use "info
2544 record" to see the obtained buffer size.
2546 maint set|show btrace pt skip-pad
2547 Set and show whether PAD packets are skipped when computing the
2550 * The command 'thread apply all' can now support new option '-ascending'
2551 to call its specified command for all threads in ascending order.
2553 * Python/Guile scripting
2555 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2556 special section named `.debug_gdb_scripts'.
2558 * New remote packets
2560 qXfer:btrace-conf:read
2561 Return the branch trace configuration for the current thread.
2563 Qbtrace-conf:bts:size
2564 Set the requested ring buffer size for branch tracing in BTS format.
2567 Enable Intel Processor Trace-based branch tracing for the current
2568 process. The remote stub reports support for this packet to GDB's
2571 Qbtrace-conf:pt:size
2572 Set the requested ring buffer size for branch tracing in Intel Processor
2576 Indicates a memory breakpoint instruction was executed, irrespective
2577 of whether it was GDB that planted the breakpoint or the breakpoint
2578 is hardcoded in the program. This is required for correct non-stop
2582 Indicates the target stopped for a hardware breakpoint. This is
2583 required for correct non-stop mode operation.
2586 Return information about files on the remote system.
2588 qXfer:exec-file:read
2589 Return the full absolute name of the file that was executed to
2590 create a process running on the remote system.
2593 Select the filesystem on which vFile: operations with filename
2594 arguments will operate. This is required for GDB to be able to
2595 access files on remote targets where the remote stub does not
2596 share a common filesystem with the inferior(s).
2599 Indicates that a fork system call was executed.
2602 Indicates that a vfork system call was executed.
2604 vforkdone stop reason
2605 Indicates that a vfork child of the specified process has executed
2606 an exec or exit, allowing the vfork parent to resume execution.
2608 fork-events and vfork-events features in qSupported
2609 The qSupported packet allows GDB to request support for fork and
2610 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2611 and the qSupported response can contain the corresponding
2612 'stubfeatures'. Set and show commands can be used to display
2613 whether these features are enabled.
2615 * Extended-remote fork events
2617 ** GDB now has support for fork events on extended-remote Linux
2618 targets. For targets with Linux kernels 2.5.60 and later, this
2619 enables follow-fork-mode and detach-on-fork for both fork and
2620 vfork, as well as fork and vfork catchpoints.
2622 * The info record command now shows the recording format and the
2623 branch tracing configuration for the current thread when using
2624 the btrace record target.
2625 For the BTS format, it shows the ring buffer size.
2627 * GDB now has support for DTrace USDT (Userland Static Defined
2628 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2630 * GDB now supports access to vector registers on S/390 GNU/Linux
2633 * Removed command line options
2635 -xdb HP-UX XDB compatibility mode.
2637 * Removed targets and native configurations
2639 HP/PA running HP-UX hppa*-*-hpux*
2640 Itanium running HP-UX ia64-*-hpux*
2642 * New configure options
2645 This configure option allows the user to build GDB with support for
2646 Intel Processor Trace (default: auto). This requires libipt.
2648 --with-libipt-prefix=PATH
2649 Specify the path to the version of libipt that GDB should use.
2650 $PATH/include should contain the intel-pt.h header and
2651 $PATH/lib should contain the libipt.so library.
2653 *** Changes in GDB 7.9.1
2657 ** Xmethods can now specify a result type.
2659 *** Changes in GDB 7.9
2661 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2665 ** You can now access frame registers from Python scripts.
2666 ** New attribute 'producer' for gdb.Symtab objects.
2667 ** gdb.Objfile objects have a new attribute "progspace",
2668 which is the gdb.Progspace object of the containing program space.
2669 ** gdb.Objfile objects have a new attribute "owner".
2670 ** gdb.Objfile objects have a new attribute "build_id",
2671 which is the build ID generated when the file was built.
2672 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2673 ** A new event "gdb.clear_objfiles" has been added, triggered when
2674 selecting a new file to debug.
2675 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2676 ** New function gdb.lookup_objfile.
2678 New events which are triggered when GDB modifies the state of the
2681 ** gdb.events.inferior_call_pre: Function call is about to be made.
2682 ** gdb.events.inferior_call_post: Function call has just been made.
2683 ** gdb.events.memory_changed: A memory location has been altered.
2684 ** gdb.events.register_changed: A register has been altered.
2686 * New Python-based convenience functions:
2688 ** $_caller_is(name [, number_of_frames])
2689 ** $_caller_matches(regexp [, number_of_frames])
2690 ** $_any_caller_is(name [, number_of_frames])
2691 ** $_any_caller_matches(regexp [, number_of_frames])
2693 * GDB now supports the compilation and injection of source code into
2694 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2695 to compile the source code to object code, and if successful, inject
2696 and execute that code within the current context of the inferior.
2697 Currently the C language is supported. The commands used to
2698 interface with this new feature are:
2700 compile code [-raw|-r] [--] [source code]
2701 compile file [-raw|-r] filename
2705 demangle [-l language] [--] name
2706 Demangle "name" in the specified language, or the current language
2707 if elided. This command is renamed from the "maint demangle" command.
2708 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2709 as "maint demangler-warning".
2711 queue-signal signal-name-or-number
2712 Queue a signal to be delivered to the thread when it is resumed.
2714 add-auto-load-scripts-directory directory
2715 Add entries to the list of directories from which to load auto-loaded
2718 maint print user-registers
2719 List all currently available "user" registers.
2721 compile code [-r|-raw] [--] [source code]
2722 Compile, inject, and execute in the inferior the executable object
2723 code produced by compiling the provided source code.
2725 compile file [-r|-raw] filename
2726 Compile and inject into the inferior the executable object code
2727 produced by compiling the source code stored in the filename
2730 * On resume, GDB now always passes the signal the program had stopped
2731 for to the thread the signal was sent to, even if the user changed
2732 threads before resuming. Previously GDB would often (but not
2733 always) deliver the signal to the thread that happens to be current
2736 * Conversely, the "signal" command now consistently delivers the
2737 requested signal to the current thread. GDB now asks for
2738 confirmation if the program had stopped for a signal and the user
2739 switched threads meanwhile.
2741 * "breakpoint always-inserted" modes "off" and "auto" merged.
2743 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2744 won't remove breakpoints from the target until all threads stop,
2745 even in non-stop mode. The "auto" mode has been removed, and "off"
2746 is now the default mode.
2750 set debug symbol-lookup
2751 show debug symbol-lookup
2752 Control display of debugging info regarding symbol lookup.
2756 ** The -list-thread-groups command outputs an exit-code field for
2757 inferiors that have exited.
2761 MIPS SDE mips*-sde*-elf*
2765 Support for these obsolete configurations has been removed.
2767 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2768 SGI Irix-5.x mips-*-irix5*
2769 SGI Irix-6.x mips-*-irix6*
2770 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2771 VAX running Ultrix vax-*-ultrix*
2773 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2774 and "assf"), have been removed. Use the "sharedlibrary" command, or
2775 its alias "share", instead.
2777 *** Changes in GDB 7.8
2779 * New command line options
2782 This is an alias for the --data-directory option.
2784 * GDB supports printing and modifying of variable length automatic arrays
2785 as specified in ISO C99.
2787 * The ARM simulator now supports instruction level tracing
2788 with or without disassembly.
2792 GDB now has support for scripting using Guile. Whether this is
2793 available is determined at configure time.
2794 Guile version 2.0 or greater is required.
2795 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2797 * New commands (for set/show, see "New options" below)
2801 Invoke CODE by passing it to the Guile interpreter.
2805 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2807 info auto-load guile-scripts [regexp]
2808 Print the list of automatically loaded Guile scripts.
2810 * The source command is now capable of sourcing Guile scripts.
2811 This feature is dependent on the debugger being built with Guile support.
2815 set print symbol-loading (off|brief|full)
2816 show print symbol-loading
2817 Control whether to print informational messages when loading symbol
2818 information for a file. The default is "full", but when debugging
2819 programs with large numbers of shared libraries the amount of output
2820 becomes less useful.
2822 set guile print-stack (none|message|full)
2823 show guile print-stack
2824 Show a stack trace when an error is encountered in a Guile script.
2826 set auto-load guile-scripts (on|off)
2827 show auto-load guile-scripts
2828 Control auto-loading of Guile script files.
2830 maint ada set ignore-descriptive-types (on|off)
2831 maint ada show ignore-descriptive-types
2832 Control whether the debugger should ignore descriptive types in Ada
2833 programs. The default is not to ignore the descriptive types. See
2834 the user manual for more details on descriptive types and the intended
2835 usage of this option.
2837 set auto-connect-native-target
2839 Control whether GDB is allowed to automatically connect to the
2840 native target for the run, attach, etc. commands when not connected
2841 to any target yet. See also "target native" below.
2843 set record btrace replay-memory-access (read-only|read-write)
2844 show record btrace replay-memory-access
2845 Control what memory accesses are allowed during replay.
2847 maint set target-async (on|off)
2848 maint show target-async
2849 This controls whether GDB targets operate in synchronous or
2850 asynchronous mode. Normally the default is asynchronous, if it is
2851 available; but this can be changed to more easily debug problems
2852 occurring only in synchronous mode.
2854 set mi-async (on|off)
2856 Control whether MI asynchronous mode is preferred. This supersedes
2857 "set target-async" of previous GDB versions.
2859 * "set target-async" is deprecated as a CLI option and is now an alias
2860 for "set mi-async" (only puts MI into async mode).
2862 * Background execution commands (e.g., "c&", "s&", etc.) are now
2863 possible ``out of the box'' if the target supports them. Previously
2864 the user would need to explicitly enable the possibility with the
2865 "set target-async on" command.
2867 * New features in the GDB remote stub, GDBserver
2869 ** New option --debug-format=option1[,option2,...] allows one to add
2870 additional text to each output. At present only timestamps
2871 are supported: --debug-format=timestamps.
2872 Timestamps can also be turned on with the
2873 "monitor set debug-format timestamps" command from GDB.
2875 * The 'record instruction-history' command now starts counting instructions
2876 at one. This also affects the instruction ranges reported by the
2877 'record function-call-history' command when given the /i modifier.
2879 * The command 'record function-call-history' supports a new modifier '/c' to
2880 indent the function names based on their call stack depth.
2881 The fields for the '/i' and '/l' modifier have been reordered.
2882 The source line range is now prefixed with 'at'.
2883 The instruction range is now prefixed with 'inst'.
2884 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2885 "record instruction-history" and "list" commands.
2887 * The ranges given as arguments to the 'record function-call-history' and
2888 'record instruction-history' commands are now inclusive.
2890 * The btrace record target now supports the 'record goto' command.
2891 For locations inside the execution trace, the back trace is computed
2892 based on the information stored in the execution trace.
2894 * The btrace record target supports limited reverse execution and replay.
2895 The target does not record data and therefore does not allow reading
2896 memory or registers.
2898 * The "catch syscall" command now works on s390*-linux* targets.
2900 * The "compare-sections" command is no longer specific to target
2901 remote. It now works with all targets.
2903 * All native targets are now consistently called "native".
2904 Consequently, the "target child", "target GNU", "target djgpp",
2905 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2906 commands have been replaced with "target native". The QNX/NTO port
2907 leaves the "procfs" target in place and adds a "native" target for
2908 consistency with other ports. The impact on users should be minimal
2909 as these commands previously either throwed an error, or were
2910 no-ops. The target's name is visible in the output of the following
2911 commands: "help target", "info target", "info files", "maint print
2914 * The "target native" command now connects to the native target. This
2915 can be used to launch native programs even when "set
2916 auto-connect-native-target" is set to off.
2918 * GDB now supports access to Intel MPX registers on GNU/Linux.
2920 * Support for Intel AVX-512 registers on GNU/Linux.
2921 Support displaying and modifying Intel AVX-512 registers
2922 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2924 * New remote packets
2926 qXfer:btrace:read's annex
2927 The qXfer:btrace:read packet supports a new annex 'delta' to read
2928 branch trace incrementally.
2932 ** Valid Python operations on gdb.Value objects representing
2933 structs/classes invoke the corresponding overloaded operators if
2935 ** New `Xmethods' feature in the Python API. Xmethods are
2936 additional methods or replacements for existing methods of a C++
2937 class. This feature is useful for those cases where a method
2938 defined in C++ source code could be inlined or optimized out by
2939 the compiler, making it unavailable to GDB.
2942 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2944 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2945 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2946 its alias "share", instead.
2948 * The commands "set remotebaud" and "show remotebaud" are no longer
2949 supported. Use "set serial baud" and "show serial baud" (respectively)
2954 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2955 target-async". The latter is left as a deprecated alias of the
2956 former for backward compatibility. If the target supports it,
2957 CLI background execution commands are now always possible by
2958 default, independently of whether the frontend stated a
2959 preference for asynchronous execution with "-gdb-set mi-async".
2960 Previously "-gdb-set target-async off" affected both MI execution
2961 commands and CLI execution commands.
2963 *** Changes in GDB 7.7
2965 * Improved support for process record-replay and reverse debugging on
2966 arm*-linux* targets. Support for thumb32 and syscall instruction
2967 recording has been added.
2969 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2971 * GDB now supports Fission DWP file format version 2.
2972 http://gcc.gnu.org/wiki/DebugFission
2974 * New convenience function "$_isvoid", to check whether an expression
2975 is void. A void expression is an expression where the type of the
2976 result is "void". For example, some convenience variables may be
2977 "void" when evaluated (e.g., "$_exitcode" before the execution of
2978 the program being debugged; or an undefined convenience variable).
2979 Another example, when calling a function whose return type is
2982 * The "maintenance print objfiles" command now takes an optional regexp.
2984 * The "catch syscall" command now works on arm*-linux* targets.
2986 * GDB now consistently shows "<not saved>" when printing values of
2987 registers the debug info indicates have not been saved in the frame
2988 and there's nowhere to retrieve them from
2989 (callee-saved/call-clobbered registers):
2994 (gdb) info registers rax
2997 Before, the former would print "<optimized out>", and the latter
2998 "*value not available*".
3000 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3005 ** Frame filters and frame decorators have been added.
3006 ** Temporary breakpoints are now supported.
3007 ** Line tables representation has been added.
3008 ** New attribute 'parent_type' for gdb.Field objects.
3009 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3010 ** New attribute 'name' for gdb.Type objects.
3014 Nios II ELF nios2*-*-elf
3015 Nios II GNU/Linux nios2*-*-linux
3016 Texas Instruments MSP430 msp430*-*-elf
3018 * Removed native configurations
3020 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3021 been removed. ELF variants of these configurations are kept supported.
3023 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3024 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3025 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3026 i[34567]86-*-openbsd3.[0-3]
3027 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3028 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3029 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3033 Like "catch throw", but catches a re-thrown exception.
3034 maint check-psymtabs
3035 Renamed from old "maint check-symtabs".
3037 Perform consistency checks on symtabs.
3038 maint expand-symtabs
3039 Expand symtabs matching an optional regexp.
3042 Display the details of GDB configure-time options.
3044 maint set|show per-command
3045 maint set|show per-command space
3046 maint set|show per-command time
3047 maint set|show per-command symtab
3048 Enable display of per-command gdb resource usage.
3050 remove-symbol-file FILENAME
3051 remove-symbol-file -a ADDRESS
3052 Remove a symbol file added via add-symbol-file. The file to remove
3053 can be identified by its filename or by an address that lies within
3054 the boundaries of this symbol file in memory.
3057 info exceptions REGEXP
3058 Display the list of Ada exceptions defined in the program being
3059 debugged. If provided, only the exceptions whose names match REGEXP
3064 set debug symfile off|on
3066 Control display of debugging info regarding reading symbol files and
3067 symbol tables within those files
3069 set print raw frame-arguments
3070 show print raw frame-arguments
3071 Set/show whether to print frame arguments in raw mode,
3072 disregarding any defined pretty-printers.
3074 set remote trace-status-packet
3075 show remote trace-status-packet
3076 Set/show the use of remote protocol qTStatus packet.
3080 Control display of debugging messages related to Nios II targets.
3084 Control whether target-assisted range stepping is enabled.
3086 set startup-with-shell
3087 show startup-with-shell
3088 Specifies whether Unix child processes are started via a shell or
3093 Use the target memory cache for accesses to the code segment. This
3094 improves performance of remote debugging (particularly disassembly).
3096 * You can now use a literal value 'unlimited' for options that
3097 interpret 0 or -1 as meaning "unlimited". E.g., "set
3098 trace-buffer-size unlimited" is now an alias for "set
3099 trace-buffer-size -1" and "set height unlimited" is now an alias for
3102 * The "set debug symtab-create" debugging option of GDB has been changed to
3103 accept a verbosity level. 0 means "off", 1 provides basic debugging
3104 output, and values of 2 or greater provides more verbose output.
3106 * New command-line options
3108 Display the details of GDB configure-time options.
3110 * The command 'tsave' can now support new option '-ctf' to save trace
3111 buffer in Common Trace Format.
3113 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3116 * GDB now implements the C++ 'typeid' operator.
3118 * The new convenience variable $_exception holds the exception being
3119 thrown or caught at an exception-related catchpoint.
3121 * The exception-related catchpoints, like "catch throw", now accept a
3122 regular expression which can be used to filter exceptions by type.
3124 * The new convenience variable $_exitsignal is automatically set to
3125 the terminating signal number when the program being debugged dies
3126 due to an uncaught signal.
3130 ** All MI commands now accept an optional "--language" option.
3131 Support for this feature can be verified by using the "-list-features"
3132 command, which should contain "language-option".
3134 ** The new command -info-gdb-mi-command allows the user to determine
3135 whether a GDB/MI command is supported or not.
3137 ** The "^error" result record returned when trying to execute an undefined
3138 GDB/MI command now provides a variable named "code" whose content is the
3139 "undefined-command" error code. Support for this feature can be verified
3140 by using the "-list-features" command, which should contain
3141 "undefined-command-error-code".
3143 ** The -trace-save MI command can optionally save trace buffer in Common
3146 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3148 ** The command -data-list-register-values now accepts an optional
3149 "--skip-unavailable" option. When used, only the available registers
3152 ** The new command -trace-frame-collected dumps collected variables,
3153 computed expressions, tvars, memory and registers in a traceframe.
3155 ** The commands -stack-list-locals, -stack-list-arguments and
3156 -stack-list-variables now accept an option "--skip-unavailable".
3157 When used, only the available locals or arguments are displayed.
3159 ** The -exec-run command now accepts an optional "--start" option.
3160 When used, the command follows the same semantics as the "start"
3161 command, stopping the program's execution at the start of its
3162 main subprogram. Support for this feature can be verified using
3163 the "-list-features" command, which should contain
3164 "exec-run-start-option".
3166 ** The new commands -catch-assert and -catch-exceptions insert
3167 catchpoints stopping the program when Ada exceptions are raised.
3169 ** The new command -info-ada-exceptions provides the equivalent of
3170 the new "info exceptions" command.
3172 * New system-wide configuration scripts
3173 A GDB installation now provides scripts suitable for use as system-wide
3174 configuration scripts for the following systems:
3178 * GDB now supports target-assigned range stepping with remote targets.
3179 This improves the performance of stepping source lines by reducing
3180 the number of control packets from/to GDB. See "New remote packets"
3183 * GDB now understands the element 'tvar' in the XML traceframe info.
3184 It has the id of the collected trace state variables.
3186 * On S/390 targets that provide the transactional-execution feature,
3187 the program interruption transaction diagnostic block (TDB) is now
3188 represented as a number of additional "registers" in GDB.
3190 * New remote packets
3194 The vCont packet supports a new 'r' action, that tells the remote
3195 stub to step through an address range itself, without GDB
3196 involvemement at each single-step.
3198 qXfer:libraries-svr4:read's annex
3199 The previously unused annex of the qXfer:libraries-svr4:read packet
3200 is now used to support passing an argument list. The remote stub
3201 reports support for this argument list to GDB's qSupported query.
3202 The defined arguments are "start" and "prev", used to reduce work
3203 necessary for library list updating, resulting in significant
3206 * New features in the GDB remote stub, GDBserver
3208 ** GDBserver now supports target-assisted range stepping. Currently
3209 enabled on x86/x86_64 GNU/Linux targets.
3211 ** GDBserver now adds element 'tvar' in the XML in the reply to
3212 'qXfer:traceframe-info:read'. It has the id of the collected
3213 trace state variables.
3215 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3218 * New 'z' formatter for printing and examining memory, this displays the
3219 value as hexadecimal zero padded on the left to the size of the type.
3221 * GDB can now use Windows x64 unwinding data.
3223 * The "set remotebaud" command has been replaced by "set serial baud".
3224 Similarly, "show remotebaud" has been replaced by "show serial baud".
3225 The "set remotebaud" and "show remotebaud" commands are still available
3226 to provide backward compatibility with older versions of GDB.
3228 *** Changes in GDB 7.6
3230 * Target record has been renamed to record-full.
3231 Record/replay is now enabled with the "record full" command.
3232 This also affects settings that are associated with full record/replay
3233 that have been moved from "set/show record" to "set/show record full":
3235 set|show record full insn-number-max
3236 set|show record full stop-at-limit
3237 set|show record full memory-query
3239 * A new record target "record-btrace" has been added. The new target
3240 uses hardware support to record the control-flow of a process. It
3241 does not support replaying the execution, but it implements the
3242 below new commands for investigating the recorded execution log.
3243 This new recording method can be enabled using:
3247 The "record-btrace" target is only available on Intel Atom processors
3248 and requires a Linux kernel 2.6.32 or later.
3250 * Two new commands have been added for record/replay to give information
3251 about the recorded execution without having to replay the execution.
3252 The commands are only supported by "record btrace".
3254 record instruction-history prints the execution history at
3255 instruction granularity
3257 record function-call-history prints the execution history at
3258 function granularity
3260 * New native configurations
3262 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3263 FreeBSD/powerpc powerpc*-*-freebsd
3264 x86_64/Cygwin x86_64-*-cygwin*
3265 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3269 ARM AArch64 aarch64*-*-elf
3270 ARM AArch64 GNU/Linux aarch64*-*-linux
3271 Lynx 178 PowerPC powerpc-*-lynx*178
3272 x86_64/Cygwin x86_64-*-cygwin*
3273 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3275 * If the configured location of system.gdbinit file (as given by the
3276 --with-system-gdbinit option at configure time) is in the
3277 data-directory (as specified by --with-gdb-datadir at configure
3278 time) or in one of its subdirectories, then GDB will look for the
3279 system-wide init file in the directory specified by the
3280 --data-directory command-line option.
3282 * New command line options:
3284 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3285 other initialization files, unlike -nx which disables all of them.
3287 * Removed command line options
3289 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3292 * The 'ptype' and 'whatis' commands now accept an argument to control
3295 * 'info proc' now works on some core files.
3299 ** Vectors can be created with gdb.Type.vector.
3301 ** Python's atexit.register now works in GDB.
3303 ** Types can be pretty-printed via a Python API.
3305 ** Python 3 is now supported (in addition to Python 2.4 or later)
3307 ** New class gdb.Architecture exposes GDB's internal representation
3308 of architecture in the Python API.
3310 ** New method Frame.architecture returns the gdb.Architecture object
3311 corresponding to the frame's architecture.
3313 * New Python-based convenience functions:
3315 ** $_memeq(buf1, buf2, length)
3316 ** $_streq(str1, str2)
3318 ** $_regex(str, regex)
3320 * The 'cd' command now defaults to using '~' (the home directory) if not
3323 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3324 default for GCC since November 2000.
3326 * The command 'forward-search' can now be abbreviated as 'fo'.
3328 * The command 'info tracepoints' can now display 'installed on target'
3329 or 'not installed on target' for each non-pending location of tracepoint.
3331 * New configure options
3333 --enable-libmcheck/--disable-libmcheck
3334 By default, development versions are built with -lmcheck on hosts
3335 that support it, in order to help track memory corruption issues.
3336 Release versions, on the other hand, are built without -lmcheck
3337 by default. The --enable-libmcheck/--disable-libmcheck configure
3338 options allow the user to override that default.
3339 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3340 This configure option allows the user to build GDB with
3341 libbabeltrace using which GDB can read Common Trace Format data.
3343 * New commands (for set/show, see "New options" below)
3346 Catch signals. This is similar to "handle", but allows commands and
3347 conditions to be attached.
3350 List the BFDs known to GDB.
3352 python-interactive [command]
3354 Start a Python interactive prompt, or evaluate the optional command
3355 and print the result of expressions.
3358 "py" is a new alias for "python".
3360 enable type-printer [name]...
3361 disable type-printer [name]...
3362 Enable or disable type printers.
3366 ** For the Renesas Super-H architecture, the "regs" command has been removed
3367 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3372 set print type methods (on|off)
3373 show print type methods
3374 Control whether method declarations are displayed by "ptype".
3375 The default is to show them.
3377 set print type typedefs (on|off)
3378 show print type typedefs
3379 Control whether typedef definitions are displayed by "ptype".
3380 The default is to show them.
3382 set filename-display basename|relative|absolute
3383 show filename-display
3384 Control the way in which filenames is displayed.
3385 The default is "relative", which preserves previous behavior.
3387 set trace-buffer-size
3388 show trace-buffer-size
3389 Request target to change the size of trace buffer.
3391 set remote trace-buffer-size-packet auto|on|off
3392 show remote trace-buffer-size-packet
3393 Control the use of the remote protocol `QTBuffer:size' packet.
3397 Control display of debugging messages related to ARM AArch64.
3400 set debug coff-pe-read
3401 show debug coff-pe-read
3402 Control display of debugging messages related to reading of COFF/PE
3407 Control display of debugging messages related to Mach-O symbols
3410 set debug notification
3411 show debug notification
3412 Control display of debugging info for async remote notification.
3416 ** Command parameter changes are now notified using new async record
3417 "=cmd-param-changed".
3418 ** Trace frame changes caused by command "tfind" are now notified using
3419 new async record "=traceframe-changed".
3420 ** The creation, deletion and modification of trace state variables
3421 are now notified using new async records "=tsv-created",
3422 "=tsv-deleted" and "=tsv-modified".
3423 ** The start and stop of process record are now notified using new
3424 async record "=record-started" and "=record-stopped".
3425 ** Memory changes are now notified using new async record
3427 ** The data-disassemble command response will include a "fullname" field
3428 containing the absolute file name when source has been requested.
3429 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3430 command, to allow pattern filling of memory areas.
3431 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3432 library load/unload events.
3433 ** The response to breakpoint commands and breakpoint async records
3434 includes an "installed" field containing a boolean state about each
3435 non-pending tracepoint location is whether installed on target or not.
3436 ** Output of the "-trace-status" command includes a "trace-file" field
3437 containing the name of the trace file being examined. This field is
3438 optional, and only present when examining a trace file.
3439 ** The "fullname" field is now always present along with the "file" field,
3440 even if the file cannot be found by GDB.
3442 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3443 You must have the LZMA library available when configuring GDB for this
3444 feature to be enabled. For more information, see:
3445 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3447 * New remote packets
3450 Set the size of trace buffer. The remote stub reports support for this
3451 packet to gdb's qSupported query.
3454 Enable Branch Trace Store (BTS)-based branch tracing for the current
3455 thread. The remote stub reports support for this packet to gdb's
3459 Disable branch tracing for the current thread. The remote stub reports
3460 support for this packet to gdb's qSupported query.
3463 Read the traced branches for the current thread. The remote stub
3464 reports support for this packet to gdb's qSupported query.
3466 *** Changes in GDB 7.5
3468 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3469 for more x32 ABI info.
3471 * GDB now supports access to MIPS DSP registers on Linux targets.
3473 * GDB now supports debugging microMIPS binaries.
3475 * The "info os" command on GNU/Linux can now display information on
3476 several new classes of objects managed by the operating system:
3477 "info os procgroups" lists process groups
3478 "info os files" lists file descriptors
3479 "info os sockets" lists internet-domain sockets
3480 "info os shm" lists shared-memory regions
3481 "info os semaphores" lists semaphores
3482 "info os msg" lists message queues
3483 "info os modules" lists loaded kernel modules
3485 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3486 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3487 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3488 options and inspect the probe arguments using the new $_probe_arg family
3489 of convenience variables. You can obtain more information about SystemTap
3490 in <http://sourceware.org/systemtap/>.
3492 * GDB now supports reversible debugging on ARM, it allows you to
3493 debug basic ARM and THUMB instructions, and provides
3494 record/replay support.
3496 * The option "symbol-reloading" has been deleted as it is no longer used.
3500 ** GDB commands implemented in Python can now be put in command class
3503 ** The "maint set python print-stack on|off" is now deleted.
3505 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3506 apply "flag enum"-style pretty-printing to any enum.
3508 ** gdb.lookup_symbol can now work when there is no current frame.
3510 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3511 the source at which the symbol was defined.
3513 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3514 method 'value'. The former indicates whether the symbol needs a
3515 frame in order to compute its value, and the latter computes the
3518 ** A new method 'referenced_value' on gdb.Value objects which can
3519 dereference pointer as well as C++ reference values.
3521 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3522 which return the global and static blocks (as gdb.Block objects),
3523 of the underlying symbol table, respectively.
3525 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3526 object associated with a PC value.
3528 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3529 of the address range occupied by code for the current source line.
3531 * Go language support.
3532 GDB now supports debugging programs written in the Go programming
3535 * GDBserver now supports stdio connections.
3536 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3538 * The binary "gdbtui" can no longer be built or installed.
3539 Use "gdb -tui" instead.
3541 * GDB will now print "flag" enums specially. A flag enum is one where
3542 all the enumerator values have no bits in common when pairwise
3543 "and"ed. When printing a value whose type is a flag enum, GDB will
3544 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3545 (gdb) print (enum E) 3
3548 * The filename part of a linespec will now match trailing components
3549 of a source file name. For example, "break gcc/expr.c:1000" will
3550 now set a breakpoint in build/gcc/expr.c, but not
3551 build/libcpp/expr.c.
3553 * The "info proc" and "generate-core-file" commands will now also
3554 work on remote targets connected to GDBserver on Linux.
3556 * The command "info catch" has been removed. It has been disabled
3557 since December 2007.
3559 * The "catch exception" and "catch assert" commands now accept
3560 a condition at the end of the command, much like the "break"
3561 command does. For instance:
3563 (gdb) catch exception Constraint_Error if Barrier = True
3565 Previously, it was possible to add a condition to such catchpoints,
3566 but it had to be done as a second step, after the catchpoint had been
3567 created, using the "condition" command.
3569 * The "info static-tracepoint-marker" command will now also work on
3570 native Linux targets with in-process agent.
3572 * GDB can now set breakpoints on inlined functions.
3574 * The .gdb_index section has been updated to include symbols for
3575 inlined functions. GDB will ignore older .gdb_index sections by
3576 default, which could cause symbol files to be loaded more slowly
3577 until their .gdb_index sections can be recreated. The new command
3578 "set use-deprecated-index-sections on" will cause GDB to use any older
3579 .gdb_index sections it finds. This will restore performance, but the
3580 ability to set breakpoints on inlined functions will be lost in symbol
3581 files with older .gdb_index sections.
3583 The .gdb_index section has also been updated to record more information
3584 about each symbol. This speeds up the "info variables", "info functions"
3585 and "info types" commands when used with programs having the .gdb_index
3586 section, as well as speeding up debugging with shared libraries using
3587 the .gdb_index section.
3589 * Ada support for GDB/MI Variable Objects has been added.
3591 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3596 ** New command -info-os is the MI equivalent of "info os".
3598 ** Output logs ("set logging" and related) now include MI output.
3602 ** "set use-deprecated-index-sections on|off"
3603 "show use-deprecated-index-sections on|off"
3604 Controls the use of deprecated .gdb_index sections.
3606 ** "catch load" and "catch unload" can be used to stop when a shared
3607 library is loaded or unloaded, respectively.
3609 ** "enable count" can be used to auto-disable a breakpoint after
3612 ** "info vtbl" can be used to show the virtual method tables for
3613 C++ and Java objects.
3615 ** "explore" and its sub commands "explore value" and "explore type"
3616 can be used to recursively explore values and types of
3617 expressions. These commands are available only if GDB is
3618 configured with '--with-python'.
3620 ** "info auto-load" shows status of all kinds of auto-loaded files,
3621 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3622 sequences of commands files, "info auto-load python-scripts"
3623 shows status of auto-loading Python script files,
3624 "info auto-load local-gdbinit" shows status of loading init file
3625 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3626 status of inferior specific thread debugging shared library loading.
3628 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3629 and "show auto-load-scripts" commands have been deprecated, use their
3630 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3631 and "show auto-load python-scripts" counterparts instead.
3633 ** "dprintf location,format,args..." creates a dynamic printf, which
3634 is basically a breakpoint that does a printf and immediately
3635 resumes your program's execution, so it is like a printf that you
3636 can insert dynamically at runtime instead of at compiletime.
3638 ** "set print symbol"
3640 Controls whether GDB attempts to display the symbol, if any,
3641 corresponding to addresses it prints. This defaults to "on", but
3642 you can set it to "off" to restore GDB's previous behavior.
3644 * Deprecated commands
3646 ** For the Renesas Super-H architecture, the "regs" command has been
3647 deprecated, and "info all-registers" should be used instead.
3651 Renesas RL78 rl78-*-elf
3652 HP OpenVMS ia64 ia64-hp-openvms*
3654 * GDBserver supports evaluation of breakpoint conditions. When
3655 support is advertised by GDBserver, GDB may be told to send the
3656 breakpoint conditions in bytecode form to GDBserver. GDBserver
3657 will only report the breakpoint trigger to GDB when its condition
3662 set mips compression
3663 show mips compression
3664 Select the compressed ISA encoding used in functions that have no symbol
3665 information available. The encoding can be set to either of:
3668 and is updated automatically from ELF file flags if available.
3670 set breakpoint condition-evaluation
3671 show breakpoint condition-evaluation
3672 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3673 GDBserver ("target"). Default option "auto" chooses the most efficient
3675 This option can improve debugger efficiency depending on the speed of the
3679 Disable auto-loading globally.
3682 Show auto-loading setting of all kinds of auto-loaded files.
3684 set auto-load gdb-scripts on|off
3685 show auto-load gdb-scripts
3686 Control auto-loading of GDB canned sequences of commands files.
3688 set auto-load python-scripts on|off
3689 show auto-load python-scripts
3690 Control auto-loading of Python script files.
3692 set auto-load local-gdbinit on|off
3693 show auto-load local-gdbinit
3694 Control loading of init file (.gdbinit) from current directory.
3696 set auto-load libthread-db on|off
3697 show auto-load libthread-db
3698 Control auto-loading of inferior specific thread debugging shared library.
3700 set auto-load scripts-directory <dir1>[:<dir2>...]
3701 show auto-load scripts-directory
3702 Set a list of directories from which to load auto-loaded scripts.
3703 Automatically loaded Python scripts and GDB scripts are located in one
3704 of the directories listed by this option.
3705 The delimiter (':' above) may differ according to the host platform.
3707 set auto-load safe-path <dir1>[:<dir2>...]
3708 show auto-load safe-path
3709 Set a list of directories from which it is safe to auto-load files.
3710 The delimiter (':' above) may differ according to the host platform.
3712 set debug auto-load on|off
3713 show debug auto-load
3714 Control display of debugging info for auto-loading the files above.
3716 set dprintf-style gdb|call|agent
3718 Control the way in which a dynamic printf is performed; "gdb"
3719 requests a GDB printf command, while "call" causes dprintf to call a
3720 function in the inferior. "agent" requests that the target agent
3721 (such as GDBserver) do the printing.
3723 set dprintf-function <expr>
3724 show dprintf-function
3725 set dprintf-channel <expr>
3726 show dprintf-channel
3727 Set the function and optional first argument to the call when using
3728 the "call" style of dynamic printf.
3730 set disconnected-dprintf on|off
3731 show disconnected-dprintf
3732 Control whether agent-style dynamic printfs continue to be in effect
3733 after GDB disconnects.
3735 * New configure options
3737 --with-auto-load-dir
3738 Configure default value for the 'set auto-load scripts-directory'
3739 setting above. It defaults to '$debugdir:$datadir/auto-load',
3740 $debugdir representing global debugging info directories (available
3741 via 'show debug-file-directory') and $datadir representing GDB's data
3742 directory (available via 'show data-directory').
3744 --with-auto-load-safe-path
3745 Configure default value for the 'set auto-load safe-path' setting
3746 above. It defaults to the --with-auto-load-dir setting.
3748 --without-auto-load-safe-path
3749 Set 'set auto-load safe-path' to '/', effectively disabling this
3752 * New remote packets
3754 z0/z1 conditional breakpoints extension
3756 The z0/z1 breakpoint insertion packets have been extended to carry
3757 a list of conditional expressions over to the remote stub depending on the
3758 condition evaluation mode. The use of this extension can be controlled
3759 via the "set remote conditional-breakpoints-packet" command.
3763 Specify the signals which the remote stub may pass to the debugged
3764 program without GDB involvement.
3766 * New command line options
3768 --init-command=FILE, -ix Like --command, -x but execute it
3769 before loading inferior.
3770 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3771 execute it before loading inferior.
3773 *** Changes in GDB 7.4
3775 * GDB now handles ambiguous linespecs more consistently; the existing
3776 FILE:LINE support has been expanded to other types of linespecs. A
3777 breakpoint will now be set on all matching locations in all
3778 inferiors, and locations will be added or removed according to
3781 * GDB now allows you to skip uninteresting functions and files when
3782 stepping with the "skip function" and "skip file" commands.
3784 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3785 and "show remote hardware-watchpoint-length-limit". These allows to
3786 set or show the maximum length limit (in bytes) of a remote
3787 target hardware watchpoint.
3789 This allows e.g. to use "unlimited" hardware watchpoints with the
3790 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3791 watchpoints are slower than real hardware watchpoints but are
3792 significantly faster than gdb software watchpoints.
3796 ** The register_pretty_printer function in module gdb.printing now takes
3797 an optional `replace' argument. If True, the new printer replaces any
3800 ** The "maint set python print-stack on|off" command has been
3801 deprecated and will be deleted in GDB 7.5.
3802 A new command: "set python print-stack none|full|message" has
3803 replaced it. Additionally, the default for "print-stack" is
3804 now "message", which just prints the error message without
3807 ** A prompt substitution hook (prompt_hook) is now available to the
3810 ** A new Python module, gdb.prompt has been added to the GDB Python
3811 modules library. This module provides functionality for
3812 escape sequences in prompts (used by set/show
3813 extended-prompt). These escape sequences are replaced by their
3814 corresponding value.
3816 ** Python commands and convenience-functions located in
3817 'data-directory'/python/gdb/command and
3818 'data-directory'/python/gdb/function are now automatically loaded
3821 ** Blocks now provide four new attributes. global_block and
3822 static_block will return the global and static blocks
3823 respectively. is_static and is_global are boolean attributes
3824 that indicate if the block is one of those two types.
3826 ** Symbols now provide the "type" attribute, the type of the symbol.
3828 ** The "gdb.breakpoint" function has been deprecated in favor of
3831 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3832 of a function. This class is based on the "finish" command
3833 available in the CLI.
3835 ** Type objects for struct and union types now allow access to
3836 the fields using standard Python dictionary (mapping) methods.
3837 For example, "some_type['myfield']" now works, as does
3838 "some_type.items()".
3840 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3843 ** A new function, "deep_items" has been added to the gdb.types
3844 module in the GDB Python modules library. This function returns
3845 an iterator over the fields of a struct or union type. Unlike
3846 the standard Python "iteritems" method, it will recursively traverse
3847 any anonymous fields.
3851 ** "*stopped" events can report several new "reason"s, such as
3854 ** Breakpoint changes are now notified using new async records, like
3855 "=breakpoint-modified".
3857 ** New command -ada-task-info.
3859 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3860 $sdir specifies the default system locations of shared libraries.
3861 $pdir specifies the directory where the libpthread used by the application
3864 GDB no longer looks in $sdir and $pdir after it has searched the directories
3865 mentioned in libthread-db-search-path. If you want to search those
3866 directories, they must be specified in libthread-db-search-path.
3867 The default value of libthread-db-search-path on GNU/Linux and Solaris
3868 systems is now "$sdir:$pdir".
3870 $pdir is not supported by gdbserver, it is currently ignored.
3871 $sdir is supported by gdbserver.
3873 * New configure option --with-iconv-bin.
3874 When using the internationalization support like the one in the GNU C
3875 library, GDB will invoke the "iconv" program to get a list of supported
3876 character sets. If this program lives in a non-standard location, one can
3877 use this option to specify where to find it.
3879 * When natively debugging programs on PowerPC BookE processors running
3880 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3881 watchpoints, which specify a mask in addition to an address to watch.
3882 The mask specifies that some bits of an address (the bits which are
3883 reset in the mask) should be ignored when matching the address accessed
3884 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3885 section in the user manual for more details.
3887 * The new option --once causes GDBserver to stop listening for connections once
3888 the first connection is made. The listening port used by GDBserver will
3889 become available after that.
3891 * New commands "info macros" and "alias" have been added.
3893 * New function parameters suffix @entry specifies value of function parameter
3894 at the time the function got called. Entry values are available only since
3900 "!" is now an alias of the "shell" command.
3901 Note that no space is needed between "!" and SHELL COMMAND.
3905 watch EXPRESSION mask MASK_VALUE
3906 The watch command now supports the mask argument which allows creation
3907 of masked watchpoints, if the current architecture supports this feature.
3909 info auto-load-scripts [REGEXP]
3910 This command was formerly named "maintenance print section-scripts".
3911 It is now generally useful and is no longer a maintenance-only command.
3913 info macro [-all] [--] MACRO
3914 The info macro command has new options `-all' and `--'. The first for
3915 printing all definitions of a macro. The second for explicitly specifying
3916 the end of arguments and the beginning of the macro name in case the macro
3917 name starts with a hyphen.
3919 collect[/s] EXPRESSIONS
3920 The tracepoint collect command now takes an optional modifier "/s"
3921 that directs it to dereference pointer-to-character types and
3922 collect the bytes of memory up to a zero byte. The behavior is
3923 similar to what you see when you use the regular print command on a
3924 string. An optional integer following the "/s" sets a bound on the
3925 number of bytes that will be collected.
3928 The trace start command now interprets any supplied arguments as a
3929 note to be recorded with the trace run, with an effect similar to
3930 setting the variable trace-notes.
3933 The trace stop command now interprets any arguments as a note to be
3934 mentioned along with the tstatus report that the trace was stopped
3935 with a command. The effect is similar to setting the variable
3938 * Tracepoints can now be enabled and disabled at any time after a trace
3939 experiment has been started using the standard "enable" and "disable"
3940 commands. It is now possible to start a trace experiment with no enabled
3941 tracepoints; GDB will display a warning, but will allow the experiment to
3942 begin, assuming that tracepoints will be enabled as needed while the trace
3945 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3946 locations with 4-byte instructions, when they were previously
3947 limited to locations with instructions of 5 bytes or longer.
3951 set debug dwarf2-read
3952 show debug dwarf2-read
3953 Turns on or off display of debugging messages related to reading
3954 DWARF debug info. The default is off.
3956 set debug symtab-create
3957 show debug symtab-create
3958 Turns on or off display of debugging messages related to symbol table
3959 creation. The default is off.
3962 show extended-prompt
3963 Set the GDB prompt, and allow escape sequences to be inserted to
3964 display miscellaneous information (see 'help set extended-prompt'
3965 for the list of sequences). This prompt (and any information
3966 accessed through the escape sequences) is updated every time the
3967 prompt is displayed.
3969 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3970 show print entry-values
3971 Set printing of frame argument values at function entry. In some cases
3972 GDB can determine the value of function argument which was passed by the
3973 function caller, even if the value was modified inside the called function.
3975 set debug entry-values
3976 show debug entry-values
3977 Control display of debugging info for determining frame argument values at
3978 function entry and virtual tail call frames.
3980 set basenames-may-differ
3981 show basenames-may-differ
3982 Set whether a source file may have multiple base names.
3983 (A "base name" is the name of a file with the directory part removed.
3984 Example: The base name of "/home/user/hello.c" is "hello.c".)
3985 If set, GDB will canonicalize file names (e.g., expand symlinks)
3986 before comparing them. Canonicalization is an expensive operation,
3987 but it allows the same file be known by more than one base name.
3988 If not set (the default), all source files are assumed to have just
3989 one base name, and gdb will do file name comparisons more efficiently.
3995 Set a user name and notes for the current and any future trace runs.
3996 This is useful for long-running and/or disconnected traces, to
3997 inform others (or yourself) as to who is running the trace, supply
3998 contact information, or otherwise explain what is going on.
4000 set trace-stop-notes
4001 show trace-stop-notes
4002 Set a note attached to the trace run, that is displayed when the
4003 trace has been stopped by a tstop command. This is useful for
4004 instance as an explanation, if you are stopping a trace run that was
4005 started by someone else.
4007 * New remote packets
4011 Dynamically enable a tracepoint in a started trace experiment.
4015 Dynamically disable a tracepoint in a started trace experiment.
4019 Set the user and notes of the trace run.
4023 Query the current status of a tracepoint.
4027 Query the minimum length of instruction at which a fast tracepoint may
4030 * Dcache size (number of lines) and line-size are now runtime-configurable
4031 via "set dcache line" and "set dcache line-size" commands.
4035 Texas Instruments TMS320C6x tic6x-*-*
4039 Renesas RL78 rl78-*-elf
4041 *** Changes in GDB 7.3.1
4043 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4045 *** Changes in GDB 7.3
4047 * GDB has a new command: "thread find [REGEXP]".
4048 It finds the thread id whose name, target id, or thread extra info
4049 matches the given regular expression.
4051 * The "catch syscall" command now works on mips*-linux* targets.
4053 * The -data-disassemble MI command now supports modes 2 and 3 for
4054 dumping the instruction opcodes.
4056 * New command line options
4058 -data-directory DIR Specify DIR as the "data-directory".
4059 This is mostly for testing purposes.
4061 * The "maint set python auto-load on|off" command has been renamed to
4062 "set auto-load-scripts on|off".
4064 * GDB has a new command: "set directories".
4065 It is like the "dir" command except that it replaces the
4066 source path list instead of augmenting it.
4068 * GDB now understands thread names.
4070 On GNU/Linux, "info threads" will display the thread name as set by
4071 prctl or pthread_setname_np.
4073 There is also a new command, "thread name", which can be used to
4074 assign a name internally for GDB to display.
4077 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4078 has been integrated into GDB.
4082 ** The function gdb.Write now accepts an optional keyword 'stream'.
4083 This keyword, when provided, will direct the output to either
4084 stdout, stderr, or GDB's logging output.
4086 ** Parameters can now be be sub-classed in Python, and in particular
4087 you may implement the get_set_doc and get_show_doc functions.
4088 This improves how Parameter set/show documentation is processed
4089 and allows for more dynamic content.
4091 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4092 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4093 have an is_valid method.
4095 ** Breakpoints can now be sub-classed in Python, and in particular
4096 you may implement a 'stop' function that is executed each time
4097 the inferior reaches that breakpoint.
4099 ** New function gdb.lookup_global_symbol looks up a global symbol.
4101 ** GDB values in Python are now callable if the value represents a
4102 function. For example, if 'some_value' represents a function that
4103 takes two integer parameters and returns a value, you can call
4104 that function like so:
4106 result = some_value (10,20)
4108 ** Module gdb.types has been added.
4109 It contains a collection of utilities for working with gdb.Types objects:
4110 get_basic_type, has_field, make_enum_dict.
4112 ** Module gdb.printing has been added.
4113 It contains utilities for writing and registering pretty-printers.
4114 New classes: PrettyPrinter, SubPrettyPrinter,
4115 RegexpCollectionPrettyPrinter.
4116 New function: register_pretty_printer.
4118 ** New commands "info pretty-printers", "enable pretty-printer" and
4119 "disable pretty-printer" have been added.
4121 ** gdb.parameter("directories") is now available.
4123 ** New function gdb.newest_frame returns the newest frame in the
4126 ** The gdb.InferiorThread class has a new "name" attribute. This
4127 holds the thread's name.
4129 ** Python Support for Inferior events.
4130 Python scripts can add observers to be notified of events
4131 occurring in the process being debugged.
4132 The following events are currently supported:
4133 - gdb.events.cont Continue event.
4134 - gdb.events.exited Inferior exited event.
4135 - gdb.events.stop Signal received, and Breakpoint hit events.
4139 ** GDB now puts template parameters in scope when debugging in an
4140 instantiation. For example, if you have:
4142 template<int X> int func (void) { return X; }
4144 then if you step into func<5>, "print X" will show "5". This
4145 feature requires proper debuginfo support from the compiler; it
4146 was added to GCC 4.5.
4148 ** The motion commands "next", "finish", "until", and "advance" now
4149 work better when exceptions are thrown. In particular, GDB will
4150 no longer lose control of the inferior; instead, the GDB will
4151 stop the inferior at the point at which the exception is caught.
4152 This functionality requires a change in the exception handling
4153 code that was introduced in GCC 4.5.
4155 * GDB now follows GCC's rules on accessing volatile objects when
4156 reading or writing target state during expression evaluation.
4157 One notable difference to prior behavior is that "print x = 0"
4158 no longer generates a read of x; the value of the assignment is
4159 now always taken directly from the value being assigned.
4161 * GDB now has some support for using labels in the program's source in
4162 linespecs. For instance, you can use "advance label" to continue
4163 execution to a label.
4165 * GDB now has support for reading and writing a new .gdb_index
4166 section. This section holds a fast index of DWARF debugging
4167 information and can be used to greatly speed up GDB startup and
4168 operation. See the documentation for `save gdb-index' for details.
4170 * The "watch" command now accepts an optional "-location" argument.
4171 When used, this causes GDB to watch the memory referred to by the
4172 expression. Such a watchpoint is never deleted due to it going out
4175 * GDB now supports thread debugging of core dumps on GNU/Linux.
4177 GDB now activates thread debugging using the libthread_db library
4178 when debugging GNU/Linux core dumps, similarly to when debugging
4179 live processes. As a result, when debugging a core dump file, GDB
4180 is now able to display pthread_t ids of threads. For example, "info
4181 threads" shows the same output as when debugging the process when it
4182 was live. In earlier releases, you'd see something like this:
4185 * 1 LWP 6780 main () at main.c:10
4187 While now you see this:
4190 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4192 It is also now possible to inspect TLS variables when debugging core
4195 When debugging a core dump generated on a machine other than the one
4196 used to run GDB, you may need to point GDB at the correct
4197 libthread_db library with the "set libthread-db-search-path"
4198 command. See the user manual for more details on this command.
4200 * When natively debugging programs on PowerPC BookE processors running
4201 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4202 which stop execution of the inferior whenever it executes an instruction
4203 at any address within the specified range. See the "PowerPC Embedded"
4204 section in the user manual for more details.
4206 * New features in the GDB remote stub, GDBserver
4208 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4209 and i686 LynxOS (version 5.x).
4211 ** GDBserver is now supported on Blackfin Linux.
4213 * New native configurations
4215 ia64 HP-UX ia64-*-hpux*
4219 Analog Devices, Inc. Blackfin Processor bfin-*
4221 * Ada task switching is now supported on sparc-elf targets when
4222 debugging a program using the Ravenscar Profile. For more information,
4223 see the "Tasking Support when using the Ravenscar Profile" section
4224 in the GDB user manual.
4226 * Guile support was removed.
4228 * New features in the GNU simulator
4230 ** The --map-info flag lists all known core mappings.
4232 ** CFI flashes may be simulated via the "cfi" device.
4234 *** Changes in GDB 7.2
4236 * Shared library support for remote targets by default
4238 When GDB is configured for a generic, non-OS specific target, like
4239 for example, --target=arm-eabi or one of the many *-*-elf targets,
4240 GDB now queries remote stubs for loaded shared libraries using the
4241 `qXfer:libraries:read' packet. Previously, shared library support
4242 was always disabled for such configurations.
4246 ** Argument Dependent Lookup (ADL)
4248 In C++ ADL lookup directs function search to the namespaces of its
4249 arguments even if the namespace has not been imported.
4259 Here the compiler will search for `foo' in the namespace of 'b'
4260 and find A::foo. GDB now supports this. This construct is commonly
4261 used in the Standard Template Library for operators.
4263 ** Improved User Defined Operator Support
4265 In addition to member operators, GDB now supports lookup of operators
4266 defined in a namespace and imported with a `using' directive, operators
4267 defined in the global scope, operators imported implicitly from an
4268 anonymous namespace, and the ADL operators mentioned in the previous
4270 GDB now also supports proper overload resolution for all the previously
4271 mentioned flavors of operators.
4273 ** static const class members
4275 Printing of static const class members that are initialized in the
4276 class definition has been fixed.
4278 * Windows Thread Information Block access.
4280 On Windows targets, GDB now supports displaying the Windows Thread
4281 Information Block (TIB) structure. This structure is visible either
4282 by using the new command `info w32 thread-information-block' or, by
4283 dereferencing the new convenience variable named `$_tlb', a
4284 thread-specific pointer to the TIB. This feature is also supported
4285 when remote debugging using GDBserver.
4287 * Static tracepoints
4289 Static tracepoints are calls in the user program into a tracing
4290 library. One such library is a port of the LTTng kernel tracer to
4291 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4292 When debugging with GDBserver, GDB now supports combining the GDB
4293 tracepoint machinery with such libraries. For example: the user can
4294 use GDB to probe a static tracepoint marker (a call from the user
4295 program into the tracing library) with the new "strace" command (see
4296 "New commands" below). This creates a "static tracepoint" in the
4297 breakpoint list, that can be manipulated with the same feature set
4298 as fast and regular tracepoints. E.g., collect registers, local and
4299 global variables, collect trace state variables, and define
4300 tracepoint conditions. In addition, the user can collect extra
4301 static tracepoint marker specific data, by collecting the new
4302 $_sdata internal variable. When analyzing the trace buffer, you can
4303 inspect $_sdata like any other variable available to GDB. For more
4304 information, see the "Tracepoints" chapter in GDB user manual. New
4305 remote packets have been defined to support static tracepoints, see
4306 the "New remote packets" section below.
4308 * Better reconstruction of tracepoints after disconnected tracing
4310 GDB will attempt to download the original source form of tracepoint
4311 definitions when starting a trace run, and then will upload these
4312 upon reconnection to the target, resulting in a more accurate
4313 reconstruction of the tracepoints that are in use on the target.
4317 You can now exercise direct control over the ways that GDB can
4318 affect your program. For instance, you can disallow the setting of
4319 breakpoints, so that the program can run continuously (assuming
4320 non-stop mode). In addition, the "observer" variable is available
4321 to switch all of the different controls; in observer mode, GDB
4322 cannot affect the target's behavior at all, which is useful for
4323 tasks like diagnosing live systems in the field.
4325 * The new convenience variable $_thread holds the number of the
4328 * New remote packets
4332 Return the address of the Windows Thread Information Block of a given thread.
4336 In response to several of the tracepoint packets, the target may now
4337 also respond with a number of intermediate `qRelocInsn' request
4338 packets before the final result packet, to have GDB handle
4339 relocating an instruction to execute at a different address. This
4340 is particularly useful for stubs that support fast tracepoints. GDB
4341 reports support for this feature in the qSupported packet.
4345 List static tracepoint markers in the target program.
4349 List static tracepoint markers at a given address in the target
4352 qXfer:statictrace:read
4354 Read the static trace data collected (by a `collect $_sdata'
4355 tracepoint action). The remote stub reports support for this packet
4356 to gdb's qSupported query.
4360 Send the current settings of GDB's permission flags.
4364 Send part of the source (textual) form of a tracepoint definition,
4365 which includes location, conditional, and action list.
4367 * The source command now accepts a -s option to force searching for the
4368 script in the source search path even if the script name specifies
4371 * New features in the GDB remote stub, GDBserver
4373 - GDBserver now support tracepoints (including fast tracepoints, and
4374 static tracepoints). The feature is currently supported by the
4375 i386-linux and amd64-linux builds. See the "Tracepoints support
4376 in gdbserver" section in the manual for more information.
4378 GDBserver JIT compiles the tracepoint's conditional agent
4379 expression bytecode into native code whenever possible for low
4380 overhead dynamic tracepoints conditionals. For such tracepoints,
4381 an expression that examines program state is evaluated when the
4382 tracepoint is reached, in order to determine whether to capture
4383 trace data. If the condition is simple and false, processing the
4384 tracepoint finishes very quickly and no data is gathered.
4386 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4387 for static tracepoints support.
4389 - GDBserver now supports x86_64 Windows 64-bit debugging.
4391 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4392 it understands register description.
4394 * The --batch flag now disables pagination and queries.
4396 * X86 general purpose registers
4398 GDB now supports reading/writing byte, word and double-word x86
4399 general purpose registers directly. This means you can use, say,
4400 $ah or $ax to refer, respectively, to the byte register AH and
4401 16-bit word register AX that are actually portions of the 32-bit
4402 register EAX or 64-bit register RAX.
4404 * The `commands' command now accepts a range of breakpoints to modify.
4405 A plain `commands' following a command that creates multiple
4406 breakpoints affects all the breakpoints set by that command. This
4407 applies to breakpoints set by `rbreak', and also applies when a
4408 single `break' command creates multiple breakpoints (e.g.,
4409 breakpoints on overloaded c++ functions).
4411 * The `rbreak' command now accepts a filename specification as part of
4412 its argument, limiting the functions selected by the regex to those
4413 in the specified file.
4415 * Support for remote debugging Windows and SymbianOS shared libraries
4416 from Unix hosts has been improved. Non Windows GDB builds now can
4417 understand target reported file names that follow MS-DOS based file
4418 system semantics, such as file names that include drive letters and
4419 use the backslash character as directory separator. This makes it
4420 possible to transparently use the "set sysroot" and "set
4421 solib-search-path" on Unix hosts to point as host copies of the
4422 target's shared libraries. See the new command "set
4423 target-file-system-kind" described below, and the "Commands to
4424 specify files" section in the user manual for more information.
4428 eval template, expressions...
4429 Convert the values of one or more expressions under the control
4430 of the string template to a command line, and call it.
4432 set target-file-system-kind unix|dos-based|auto
4433 show target-file-system-kind
4434 Set or show the assumed file system kind for target reported file
4437 save breakpoints <filename>
4438 Save all current breakpoint definitions to a file suitable for use
4439 in a later debugging session. To read the saved breakpoint
4440 definitions, use the `source' command.
4442 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4445 info static-tracepoint-markers
4446 Display information about static tracepoint markers in the target.
4448 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4449 Define a static tracepoint by probing a marker at the given
4450 function, line, address, or marker ID.
4454 Enable and disable observer mode.
4456 set may-write-registers on|off
4457 set may-write-memory on|off
4458 set may-insert-breakpoints on|off
4459 set may-insert-tracepoints on|off
4460 set may-insert-fast-tracepoints on|off
4461 set may-interrupt on|off
4462 Set individual permissions for GDB effects on the target. Note that
4463 some of these settings can have undesirable or surprising
4464 consequences, particularly when changed in the middle of a session.
4465 For instance, disabling the writing of memory can prevent
4466 breakpoints from being inserted, cause single-stepping to fail, or
4467 even crash your program, if you disable after breakpoints have been
4468 inserted. However, GDB should not crash.
4470 set record memory-query on|off
4471 show record memory-query
4472 Control whether to stop the inferior if memory changes caused
4473 by an instruction cannot be recorded.
4478 The disassemble command now supports "start,+length" form of two arguments.
4482 ** GDB now provides a new directory location, called the python directory,
4483 where Python scripts written for GDB can be installed. The location
4484 of that directory is <data-directory>/python, where <data-directory>
4485 is the GDB data directory. For more details, see section `Scripting
4486 GDB using Python' in the manual.
4488 ** The GDB Python API now has access to breakpoints, symbols, symbol
4489 tables, program spaces, inferiors, threads and frame's code blocks.
4490 Additionally, GDB Parameters can now be created from the API, and
4491 manipulated via set/show in the CLI.
4493 ** New functions gdb.target_charset, gdb.target_wide_charset,
4494 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4496 ** New exception gdb.GdbError.
4498 ** Pretty-printers are now also looked up in the current program space.
4500 ** Pretty-printers can now be individually enabled and disabled.
4502 ** GDB now looks for names of Python scripts to auto-load in a
4503 special section named `.debug_gdb_scripts', in addition to looking
4504 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4506 * Tracepoint actions were unified with breakpoint commands. In particular,
4507 there are no longer differences in "info break" output for breakpoints and
4508 tracepoints and the "commands" command can be used for both tracepoints and
4509 regular breakpoints.
4513 ARM Symbian arm*-*-symbianelf*
4515 * D language support.
4516 GDB now supports debugging programs written in the D programming
4519 * GDB now supports the extended ptrace interface for PowerPC which is
4520 available since Linux kernel version 2.6.34. This automatically enables
4521 any hardware breakpoints and additional hardware watchpoints available in
4522 the processor. The old ptrace interface exposes just one hardware
4523 watchpoint and no hardware breakpoints.
4525 * GDB is now able to use the Data Value Compare (DVC) register available on
4526 embedded PowerPC processors to implement in hardware simple watchpoint
4527 conditions of the form:
4529 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4531 This works in native GDB running on Linux kernels with the extended ptrace
4532 interface mentioned above.
4534 *** Changes in GDB 7.1
4538 ** Namespace Support
4540 GDB now supports importing of namespaces in C++. This enables the
4541 user to inspect variables from imported namespaces. Support for
4542 namepace aliasing has also been added. So, if a namespace is
4543 aliased in the current scope (e.g. namepace C=A; ) the user can
4544 print variables using the alias (e.g. (gdb) print C::x).
4548 All known bugs relating to the printing of virtual base class were
4549 fixed. It is now possible to call overloaded static methods using a
4554 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4555 and reinterpret_cast<> are now handled by the C++ expression parser.
4559 Xilinx MicroBlaze microblaze-*-*
4564 Xilinx MicroBlaze microblaze
4567 * Multi-program debugging.
4569 GDB now has support for multi-program (a.k.a. multi-executable or
4570 multi-exec) debugging. This allows for debugging multiple inferiors
4571 simultaneously each running a different program under the same GDB
4572 session. See "Debugging Multiple Inferiors and Programs" in the
4573 manual for more information. This implied some user visible changes
4574 in the multi-inferior support. For example, "info inferiors" now
4575 lists inferiors that are not running yet or that have exited
4576 already. See also "New commands" and "New options" below.
4578 * New tracing features
4580 GDB's tracepoint facility now includes several new features:
4582 ** Trace state variables
4584 GDB tracepoints now include support for trace state variables, which
4585 are variables managed by the target agent during a tracing
4586 experiment. They are useful for tracepoints that trigger each
4587 other, so for instance one tracepoint can count hits in a variable,
4588 and then a second tracepoint has a condition that is true when the
4589 count reaches a particular value. Trace state variables share the
4590 $-syntax of GDB convenience variables, and can appear in both
4591 tracepoint actions and condition expressions. Use the "tvariable"
4592 command to create, and "info tvariables" to view; see "Trace State
4593 Variables" in the manual for more detail.
4597 GDB now includes an option for defining fast tracepoints, which
4598 targets may implement more efficiently, such as by installing a jump
4599 into the target agent rather than a trap instruction. The resulting
4600 speedup can be by two orders of magnitude or more, although the
4601 tradeoff is that some program locations on some target architectures
4602 might not allow fast tracepoint installation, for instance if the
4603 instruction to be replaced is shorter than the jump. To request a
4604 fast tracepoint, use the "ftrace" command, with syntax identical to
4605 the regular trace command.
4607 ** Disconnected tracing
4609 It is now possible to detach GDB from the target while it is running
4610 a trace experiment, then reconnect later to see how the experiment
4611 is going. In addition, a new variable disconnected-tracing lets you
4612 tell the target agent whether to continue running a trace if the
4613 connection is lost unexpectedly.
4617 GDB now has the ability to save the trace buffer into a file, and
4618 then use that file as a target, similarly to you can do with
4619 corefiles. You can select trace frames, print data that was
4620 collected in them, and use tstatus to display the state of the
4621 tracing run at the moment that it was saved. To create a trace
4622 file, use "tsave <filename>", and to use it, do "target tfile
4625 ** Circular trace buffer
4627 You can ask the target agent to handle the trace buffer as a
4628 circular buffer, discarding the oldest trace frames to make room for
4629 newer ones, by setting circular-trace-buffer to on. This feature may
4630 not be available for all target agents.
4635 The disassemble command, when invoked with two arguments, now requires
4636 the arguments to be comma-separated.
4639 The info variables command now displays variable definitions. Files
4640 which only declare a variable are not shown.
4643 The source command is now capable of sourcing Python scripts.
4644 This feature is dependent on the debugger being build with Python
4647 Related to this enhancement is also the introduction of a new command
4648 "set script-extension" (see below).
4650 * New commands (for set/show, see "New options" below)
4652 record save [<FILENAME>]
4653 Save a file (in core file format) containing the process record
4654 execution log for replay debugging at a later time.
4656 record restore <FILENAME>
4657 Restore the process record execution log that was saved at an
4658 earlier time, for replay debugging.
4660 add-inferior [-copies <N>] [-exec <FILENAME>]
4663 clone-inferior [-copies <N>] [ID]
4664 Make a new inferior ready to execute the same program another
4665 inferior has loaded.
4670 maint info program-spaces
4671 List the program spaces loaded into GDB.
4673 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4674 show remote interrupt-sequence
4675 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4676 as the sequence to the remote target in order to interrupt the execution.
4677 Ctrl-C is a default. Some system prefers BREAK which is high level of
4678 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4679 Magic SysRq g. It is BREAK signal and character 'g'.
4681 set remote interrupt-on-connect [on | off]
4682 show remote interrupt-on-connect
4683 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4684 remote target when gdb connects to it. This is needed when you debug
4687 set remotebreak [on | off]
4689 Deprecated. Use "set/show remote interrupt-sequence" instead.
4691 tvariable $NAME [ = EXP ]
4692 Create or modify a trace state variable.
4695 List trace state variables and their values.
4697 delete tvariable $NAME ...
4698 Delete one or more trace state variables.
4701 Evaluate the given expressions without collecting anything into the
4702 trace buffer. (Valid in tracepoint actions only.)
4704 ftrace FN / FILE:LINE / *ADDR
4705 Define a fast tracepoint at the given function, line, or address.
4707 * New expression syntax
4709 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4710 GDB now parses 0b101010 identically with 42.
4714 set follow-exec-mode new|same
4715 show follow-exec-mode
4716 Control whether GDB reuses the same inferior across an exec call or
4717 creates a new one. This is useful to be able to restart the old
4718 executable after the inferior having done an exec call.
4720 set default-collect EXPR, ...
4721 show default-collect
4722 Define a list of expressions to be collected at each tracepoint.
4723 This is a useful way to ensure essential items are not overlooked,
4724 such as registers or a critical global variable.
4726 set disconnected-tracing
4727 show disconnected-tracing
4728 If set to 1, the target is instructed to continue tracing if it
4729 loses its connection to GDB. If 0, the target is to stop tracing
4732 set circular-trace-buffer
4733 show circular-trace-buffer
4734 If set to on, the target is instructed to use a circular trace buffer
4735 and discard the oldest trace frames instead of stopping the trace due
4736 to a full trace buffer. If set to off, the trace stops when the buffer
4737 fills up. Some targets may not support this.
4739 set script-extension off|soft|strict
4740 show script-extension
4741 If set to "off", the debugger does not perform any script language
4742 recognition, and all sourced files are assumed to be GDB scripts.
4743 If set to "soft" (the default), files are sourced according to
4744 filename extension, falling back to GDB scripts if the first
4746 If set to "strict", files are sourced according to filename extension.
4748 set ada trust-PAD-over-XVS on|off
4749 show ada trust-PAD-over-XVS
4750 If off, activate a workaround against a bug in the debugging information
4751 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4752 the GCC sources for more information about the GNAT encoding and
4753 PAD types in particular). It is always safe to set this option to
4754 off, but this introduces a slight performance penalty. The default
4757 * Python API Improvements
4759 ** GDB provides the new class gdb.LazyString. This is useful in
4760 some pretty-printing cases. The new method gdb.Value.lazy_string
4761 provides a simple way to create objects of this type.
4763 ** The fields returned by gdb.Type.fields now have an
4764 `is_base_class' attribute.
4766 ** The new method gdb.Type.range returns the range of an array type.
4768 ** The new method gdb.parse_and_eval can be used to parse and
4769 evaluate an expression.
4771 * New remote packets
4774 Define a trace state variable.
4777 Get the current value of a trace state variable.
4780 Set desired tracing behavior upon disconnection.
4783 Set the trace buffer to be linear or circular.
4786 Get data about the tracepoints currently in use.
4790 Process record now works correctly with hardware watchpoints.
4792 Multiple bug fixes have been made to the mips-irix port, making it
4793 much more reliable. In particular:
4794 - Debugging threaded applications is now possible again. Previously,
4795 GDB would hang while starting the program, or while waiting for
4796 the program to stop at a breakpoint.
4797 - Attaching to a running process no longer hangs.
4798 - An error occurring while loading a core file has been fixed.
4799 - Changing the value of the PC register now works again. This fixes
4800 problems observed when using the "jump" command, or when calling
4801 a function from GDB, or even when assigning a new value to $pc.
4802 - With the "finish" and "return" commands, the return value for functions
4803 returning a small array is now correctly printed.
4804 - It is now possible to break on shared library code which gets executed
4805 during a shared library init phase (code executed while executing
4806 their .init section). Previously, the breakpoint would have no effect.
4807 - GDB is now able to backtrace through the signal handler for
4808 non-threaded programs.
4810 PIE (Position Independent Executable) programs debugging is now supported.
4811 This includes debugging execution of PIC (Position Independent Code) shared
4812 libraries although for that, it should be possible to run such libraries as an
4815 *** Changes in GDB 7.0
4817 * GDB now has an interface for JIT compilation. Applications that
4818 dynamically generate code can create symbol files in memory and register
4819 them with GDB. For users, the feature should work transparently, and
4820 for JIT developers, the interface is documented in the GDB manual in the
4821 "JIT Compilation Interface" chapter.
4823 * Tracepoints may now be conditional. The syntax is as for
4824 breakpoints; either an "if" clause appended to the "trace" command,
4825 or the "condition" command is available. GDB sends the condition to
4826 the target for evaluation using the same bytecode format as is used
4827 for tracepoint actions.
4829 * The disassemble command now supports: an optional /r modifier, print the
4830 raw instructions in hex as well as in symbolic form, and an optional /m
4831 modifier to print mixed source+assembly.
4833 * Process record and replay
4835 In a architecture environment that supports ``process record and
4836 replay'', ``process record and replay'' target can record a log of
4837 the process execution, and replay it with both forward and reverse
4840 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4841 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4842 set execution-direction {forward|reverse}, for targets that support
4845 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4846 feature is available with a native GDB running on kernel version
4849 * GDB now has support for multi-byte and wide character sets on the
4850 target. Strings whose character type is wchar_t, char16_t, or
4851 char32_t are now correctly printed. GDB supports wide- and unicode-
4852 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4853 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4854 `printf'. This feature requires iconv to work properly; if your
4855 system does not have a working iconv, GDB can use GNU libiconv. See
4856 the installation instructions for more information.
4858 * GDB now supports automatic retrieval of shared library files from
4859 remote targets. To use this feature, specify a system root that begins
4860 with the `remote:' prefix, either via the `set sysroot' command or via
4861 the `--with-sysroot' configure-time option.
4863 * "info sharedlibrary" now takes an optional regex of libraries to show,
4864 and it now reports if a shared library has no debugging information.
4866 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4867 now complete on file names.
4869 * When completing in expressions, gdb will attempt to limit
4870 completions to allowable structure or union fields, where appropriate.
4871 For instance, consider:
4873 # struct example { int f1; double f2; };
4874 # struct example variable;
4877 If the user types TAB at the end of this command line, the available
4878 completions will be "f1" and "f2".
4880 * Inlined functions are now supported. They show up in backtraces, and
4881 the "step", "next", and "finish" commands handle them automatically.
4883 * GDB now supports the token-splicing (##) and stringification (#)
4884 operators when expanding macros. It also supports variable-arity
4887 * GDB now supports inspecting extra signal information, exported by
4888 the new $_siginfo convenience variable. The feature is currently
4889 implemented on linux ARM, i386 and amd64.
4891 * GDB can now display the VFP floating point registers and NEON vector
4892 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4893 can provide these registers (requires Linux 2.6.30 or later). Remote
4894 and simulator targets may also provide them.
4896 * New remote packets
4899 Search memory for a sequence of bytes.
4902 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4903 operation over reliable transport links. Use of this packet is
4904 controlled by the `set remote noack-packet' command.
4907 Kill the process with the specified process ID. Use this in preference
4908 to `k' when multiprocess protocol extensions are supported.
4911 Obtains additional operating system information
4915 Read or write additional signal information.
4917 * Removed remote protocol undocumented extension
4919 An undocumented extension to the remote protocol's `S' stop reply
4920 packet that permitted the stub to pass a process id was removed.
4921 Remote servers should use the `T' stop reply packet instead.
4923 * GDB now supports multiple function calling conventions according to the
4924 DWARF-2 DW_AT_calling_convention function attribute.
4926 * The SH target utilizes the aforementioned change to distinguish between gcc
4927 and Renesas calling convention. It also adds the new CLI commands
4928 `set/show sh calling-convention'.
4930 * GDB can now read compressed debug sections, as produced by GNU gold
4931 with the --compress-debug-sections=zlib flag.
4933 * 64-bit core files are now supported on AIX.
4935 * Thread switching is now supported on Tru64.
4937 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4938 which will be allocated using malloc later in program execution.
4940 * The qXfer:libraries:read remote protocol packet now allows passing a
4941 list of section offsets.
4943 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4944 conditions handling signals delivered during attach or thread creation
4945 have also been fixed.
4947 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4948 From the user's standpoint, all unqualified instances of True and False
4949 are treated as the standard definitions, regardless of context.
4951 * GDB now parses C++ symbol and type names more flexibly. For
4954 template<typename T> class C { };
4957 GDB will now correctly handle all of:
4959 ptype C<char const *>
4960 ptype C<char const*>
4961 ptype C<const char *>
4962 ptype C<const char*>
4964 * New features in the GDB remote stub, gdbserver
4966 - The "--wrapper" command-line argument tells gdbserver to use a
4967 wrapper program to launch programs for debugging.
4969 - On PowerPC and S/390 targets, it is now possible to use a single
4970 gdbserver executable to debug both 32-bit and 64-bit programs.
4971 (This requires gdbserver itself to be built as a 64-bit executable.)
4973 - gdbserver uses the new noack protocol mode for TCP connections to
4974 reduce communications latency, if also supported and enabled in GDB.
4976 - Support for the sparc64-linux-gnu target is now included in
4979 - The amd64-linux build of gdbserver now supports debugging both
4980 32-bit and 64-bit programs.
4982 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4983 now support hardware watchpoints, and will use them automatically
4988 GDB now has support for scripting using Python. Whether this is
4989 available is determined at configure time.
4991 New GDB commands can now be written in Python.
4993 * Ada tasking support
4995 Ada tasks can now be inspected in GDB. The following commands have
4999 Print the list of Ada tasks.
5001 Print detailed information about task number N.
5003 Print the task number of the current task.
5005 Switch the context of debugging to task number N.
5007 * Support for user-defined prefixed commands. The "define" command can
5008 add new commands to existing prefixes, e.g. "target".
5010 * Multi-inferior, multi-process debugging.
5012 GDB now has generalized support for multi-inferior debugging. See
5013 "Debugging Multiple Inferiors" in the manual for more information.
5014 Although availability still depends on target support, the command
5015 set is more uniform now. The GNU/Linux specific multi-forks support
5016 has been migrated to this new framework. This implied some user
5017 visible changes; see "New commands" and also "Removed commands"
5020 * Target descriptions can now describe the target OS ABI. See the
5021 "Target Description Format" section in the user manual for more
5024 * Target descriptions can now describe "compatible" architectures
5025 to indicate that the target can execute applications for a different
5026 architecture in addition to those for the main target architecture.
5027 See the "Target Description Format" section in the user manual for
5030 * Multi-architecture debugging.
5032 GDB now includes general supports for debugging applications on
5033 hybrid systems that use more than one single processor architecture
5034 at the same time. Each such hybrid architecture still requires
5035 specific support to be added. The only hybrid architecture supported
5036 in this version of GDB is the Cell Broadband Engine.
5038 * GDB now supports integrated debugging of Cell/B.E. applications that
5039 use both the PPU and SPU architectures. To enable support for hybrid
5040 Cell/B.E. debugging, you need to configure GDB to support both the
5041 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5042 --enable-targets configure option.
5044 * Non-stop mode debugging.
5046 For some targets, GDB now supports an optional mode of operation in
5047 which you can examine stopped threads while other threads continue
5048 to execute freely. This is referred to as non-stop mode, with the
5049 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5050 section in the user manual for more information.
5052 To be able to support remote non-stop debugging, a remote stub needs
5053 to implement the non-stop mode remote protocol extensions, as
5054 described in the "Remote Non-Stop" section of the user manual. The
5055 GDB remote stub, gdbserver, has been adjusted to support these
5056 extensions on linux targets.
5058 * New commands (for set/show, see "New options" below)
5060 catch syscall [NAME(S) | NUMBER(S)]
5061 Catch system calls. Arguments, which should be names of system
5062 calls or their numbers, mean catch only those syscalls. Without
5063 arguments, every syscall will be caught. When the inferior issues
5064 any of the specified syscalls, GDB will stop and announce the system
5065 call, both when it is called and when its call returns. This
5066 feature is currently available with a native GDB running on the
5067 Linux Kernel, under the following architectures: x86, x86_64,
5068 PowerPC and PowerPC64.
5070 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5072 Search memory for a sequence of bytes.
5074 maint set python print-stack
5075 maint show python print-stack
5076 Show a stack trace when an error is encountered in a Python script.
5079 Invoke CODE by passing it to the Python interpreter.
5084 These allow macros to be defined, undefined, and listed
5088 Show operating system information about processes.
5091 List the inferiors currently under GDB's control.
5094 Switch focus to inferior number NUM.
5097 Detach from inferior number NUM.
5100 Kill inferior number NUM.
5104 set spu stop-on-load
5105 show spu stop-on-load
5106 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5108 set spu auto-flush-cache
5109 show spu auto-flush-cache
5110 Control whether to automatically flush the software-managed cache
5111 during Cell/B.E. debugging.
5113 set sh calling-convention
5114 show sh calling-convention
5115 Control the calling convention used when calling SH target functions.
5118 show debug timestamp
5119 Control display of timestamps with GDB debugging output.
5121 set disassemble-next-line
5122 show disassemble-next-line
5123 Control display of disassembled source lines or instructions when
5126 set remote noack-packet
5127 show remote noack-packet
5128 Set/show the use of remote protocol QStartNoAckMode packet. See above
5129 under "New remote packets."
5131 set remote query-attached-packet
5132 show remote query-attached-packet
5133 Control use of remote protocol `qAttached' (query-attached) packet.
5135 set remote read-siginfo-object
5136 show remote read-siginfo-object
5137 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5140 set remote write-siginfo-object
5141 show remote write-siginfo-object
5142 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5145 set remote reverse-continue
5146 show remote reverse-continue
5147 Control use of remote protocol 'bc' (reverse-continue) packet.
5149 set remote reverse-step
5150 show remote reverse-step
5151 Control use of remote protocol 'bs' (reverse-step) packet.
5153 set displaced-stepping
5154 show displaced-stepping
5155 Control displaced stepping mode. Displaced stepping is a way to
5156 single-step over breakpoints without removing them from the debuggee.
5157 Also known as "out-of-line single-stepping".
5160 show debug displaced
5161 Control display of debugging info for displaced stepping.
5163 maint set internal-error
5164 maint show internal-error
5165 Control what GDB does when an internal error is detected.
5167 maint set internal-warning
5168 maint show internal-warning
5169 Control what GDB does when an internal warning is detected.
5174 Use a wrapper program to launch programs for debugging.
5176 set multiple-symbols (all|ask|cancel)
5177 show multiple-symbols
5178 The value of this variable can be changed to adjust the debugger behavior
5179 when an expression or a breakpoint location contains an ambiguous symbol
5180 name (an overloaded function name, for instance).
5182 set breakpoint always-inserted
5183 show breakpoint always-inserted
5184 Keep breakpoints always inserted in the target, as opposed to inserting
5185 them when resuming the target, and removing them when the target stops.
5186 This option can improve debugger performance on slow remote targets.
5188 set arm fallback-mode (arm|thumb|auto)
5189 show arm fallback-mode
5190 set arm force-mode (arm|thumb|auto)
5192 These commands control how ARM GDB determines whether instructions
5193 are ARM or Thumb. The default for both settings is auto, which uses
5194 the current CPSR value for instructions without symbols; previous
5195 versions of GDB behaved as if "set arm fallback-mode arm".
5197 set disable-randomization
5198 show disable-randomization
5199 Standalone programs run with the virtual address space randomization enabled
5200 by default on some platforms. This option keeps the addresses stable across
5201 multiple debugging sessions.
5205 Control whether other threads are stopped or not when some thread hits
5210 Requests that asynchronous execution is enabled in the target, if available.
5211 In this case, it's possible to resume target in the background, and interact
5212 with GDB while the target is running. "show target-async" displays the
5213 current state of asynchronous execution of the target.
5215 set target-wide-charset
5216 show target-wide-charset
5217 The target-wide-charset is the name of the character set that GDB
5218 uses when printing characters whose type is wchar_t.
5220 set tcp auto-retry (on|off)
5222 set tcp connect-timeout
5223 show tcp connect-timeout
5224 These commands allow GDB to retry failed TCP connections to a remote stub
5225 with a specified timeout period; this is useful if the stub is launched
5226 in parallel with GDB but may not be ready to accept connections immediately.
5228 set libthread-db-search-path
5229 show libthread-db-search-path
5230 Control list of directories which GDB will search for appropriate
5233 set schedule-multiple (on|off)
5234 show schedule-multiple
5235 Allow GDB to resume all threads of all processes or only threads of
5236 the current process.
5240 Use more aggressive caching for accesses to the stack. This improves
5241 performance of remote debugging (particularly backtraces) without
5242 affecting correctness.
5244 set interactive-mode (on|off|auto)
5245 show interactive-mode
5246 Control whether GDB runs in interactive mode (on) or not (off).
5247 When in interactive mode, GDB waits for the user to answer all
5248 queries. Otherwise, GDB does not wait and assumes the default
5249 answer. When set to auto (the default), GDB determines which
5250 mode to use based on the stdin settings.
5255 For program forks, this is replaced by the new more generic `info
5256 inferiors' command. To list checkpoints, you can still use the
5257 `info checkpoints' command, which was an alias for the `info forks'
5261 Replaced by the new `inferior' command. To switch between
5262 checkpoints, you can still use the `restart' command, which was an
5263 alias for the `fork' command.
5266 This is removed, since some targets don't have a notion of
5267 processes. To switch between processes, you can still use the
5268 `inferior' command using GDB's own inferior number.
5271 For program forks, this is replaced by the new more generic `kill
5272 inferior' command. To delete a checkpoint, you can still use the
5273 `delete checkpoint' command, which was an alias for the `delete
5277 For program forks, this is replaced by the new more generic `detach
5278 inferior' command. To detach a checkpoint, you can still use the
5279 `detach checkpoint' command, which was an alias for the `detach
5282 * New native configurations
5284 x86/x86_64 Darwin i[34567]86-*-darwin*
5286 x86_64 MinGW x86_64-*-mingw*
5290 Lattice Mico32 lm32-*
5291 x86 DICOS i[34567]86-*-dicos*
5292 x86_64 DICOS x86_64-*-dicos*
5295 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5296 (mingw32ce) debugging.
5302 These commands were actually not implemented on any target.
5304 *** Changes in GDB 6.8
5306 * New native configurations
5308 NetBSD/hppa hppa*-*netbsd*
5309 Xtensa GNU/Linux xtensa*-*-linux*
5313 NetBSD/hppa hppa*-*-netbsd*
5314 Xtensa GNU/Linux xtensa*-*-linux*
5316 * Change in command line behavior -- corefiles vs. process ids.
5318 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5319 attaching to process NUMBER fails, GDB no longer attempts to open a
5320 core file named NUMBER. Attaching to a program using the -c option
5321 is no longer supported. Instead, use the '-p' or '--pid' options.
5323 * GDB can now be built as a native debugger for debugging Windows x86
5324 (mingw32) Portable Executable (PE) programs.
5326 * Pending breakpoints no longer change their number when their address
5329 * GDB now supports breakpoints with multiple locations,
5330 including breakpoints on C++ constructors, inside C++ templates,
5331 and in inlined functions.
5333 * GDB's ability to debug optimized code has been improved. GDB more
5334 accurately identifies function bodies and lexical blocks that occupy
5335 more than one contiguous range of addresses.
5337 * Target descriptions can now describe registers for PowerPC.
5339 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5340 registers on PowerPC targets.
5342 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5343 targets even when the libthread_db library is not available.
5345 * The GDB remote stub, gdbserver, now supports the new file transfer
5346 commands (remote put, remote get, and remote delete).
5348 * The GDB remote stub, gdbserver, now supports run and attach in
5349 extended-remote mode.
5351 * hppa*64*-*-hpux11* target broken
5352 The debugger is unable to start a program and fails with the following
5353 error: "Error trying to get information about dynamic linker".
5354 The gdb-6.7 release is also affected.
5356 * GDB now supports the --enable-targets= configure option to allow
5357 building a single GDB executable that supports multiple remote
5358 target architectures.
5360 * GDB now supports debugging C and C++ programs which use the
5361 Decimal Floating Point extension. In addition, the PowerPC target
5362 now has a set of pseudo-registers to inspect decimal float values
5363 stored in two consecutive float registers.
5365 * The -break-insert MI command can optionally create pending
5368 * Improved support for debugging Ada
5369 Many improvements to the Ada language support have been made. These
5371 - Better support for Ada2005 interface types
5372 - Improved handling of arrays and slices in general
5373 - Better support for Taft-amendment types
5374 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5376 - Improved command completion in Ada
5379 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5384 set print frame-arguments (all|scalars|none)
5385 show print frame-arguments
5386 The value of this variable can be changed to control which argument
5387 values should be printed by the debugger when displaying a frame.
5392 Transfer files to and from a remote target, and delete remote files.
5399 Transfer files to and from a remote target, and delete remote files.
5401 * New remote packets
5408 Open, close, read, write, and delete files on the remote system.
5411 Attach to an existing process on the remote system, in extended-remote
5415 Run a new process on the remote system, in extended-remote mode.
5417 *** Changes in GDB 6.7
5419 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5420 bfd, libiberty and opcodes, as revealed by static analysis donated by
5421 Coverity, Inc. (http://scan.coverity.com).
5423 * When looking up multiply-defined global symbols, GDB will now prefer the
5424 symbol definition in the current shared library if it was built using the
5425 -Bsymbolic linker option.
5427 * When the Text User Interface (TUI) is not configured, GDB will now
5428 recognize the -tui command-line option and print a message that the TUI
5431 * The GDB remote stub, gdbserver, now has lower overhead for high
5432 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5434 * GDB for MIPS targets now autodetects whether a remote target provides
5435 32-bit or 64-bit register values.
5437 * Support for C++ member pointers has been improved.
5439 * GDB now understands XML target descriptions, which specify the
5440 target's overall architecture. GDB can read a description from
5441 a local file or over the remote serial protocol.
5443 * Vectors of single-byte data use a new integer type which is not
5444 automatically displayed as character or string data.
5446 * The /s format now works with the print command. It displays
5447 arrays of single-byte integers and pointers to single-byte integers
5450 * Target descriptions can now describe target-specific registers,
5451 for architectures which have implemented the support (currently
5452 only ARM, M68K, and MIPS).
5454 * GDB and the GDB remote stub, gdbserver, now support the XScale
5457 * The GDB remote stub, gdbserver, has been updated to support
5458 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5459 has been rewritten to use the standard GDB remote protocol.
5461 * GDB can now step into C++ functions which are called through thunks.
5463 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5465 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5466 layout. It also supports a TextSeg= and DataSeg= response when only
5467 segment base addresses (rather than offsets) are available.
5469 * The /i format now outputs any trailing branch delay slot instructions
5470 immediately following the last instruction within the count specified.
5472 * The GDB remote protocol "T" stop reply packet now supports a
5473 "library" response. Combined with the new "qXfer:libraries:read"
5474 packet, this response allows GDB to debug shared libraries on targets
5475 where the operating system manages the list of loaded libraries (e.g.
5476 Windows and SymbianOS).
5478 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5479 (DLLs) on Windows and Windows CE targets.
5481 * GDB now supports a faster verification that a .debug file matches its binary
5482 according to its build-id signature, if the signature is present.
5488 Enable or disable hardware flow control (RTS/CTS) on the serial port
5489 when debugging using remote targets.
5491 set mem inaccessible-by-default
5492 show mem inaccessible-by-default
5493 If the target supplies a memory map, for instance via the remote
5494 protocol's "qXfer:memory-map:read" packet, setting this variable
5495 prevents GDB from accessing memory outside the memory map. This
5496 is useful for targets with memory mapped registers or which react
5497 badly to accesses of unmapped address space.
5499 set breakpoint auto-hw
5500 show breakpoint auto-hw
5501 If the target supplies a memory map, for instance via the remote
5502 protocol's "qXfer:memory-map:read" packet, setting this variable
5503 lets GDB use hardware breakpoints automatically for memory regions
5504 where it can not use software breakpoints. This covers both the
5505 "break" command and internal breakpoints used for other commands
5506 including "next" and "finish".
5509 catch exception unhandled
5510 Stop the program execution when Ada exceptions are raised.
5513 Stop the program execution when an Ada assertion failed.
5517 Set an alternate system root for target files. This is a more
5518 general version of "set solib-absolute-prefix", which is now
5519 an alias to "set sysroot".
5522 Provide extended SPU facility status information. This set of
5523 commands is available only when debugging the Cell/B.E. SPU
5526 * New native configurations
5528 OpenBSD/sh sh*-*openbsd*
5531 unset tdesc filename
5533 Use the specified local file as an XML target description, and do
5534 not query the target for its built-in description.
5538 OpenBSD/sh sh*-*-openbsd*
5539 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5540 Toshiba Media Processor mep-elf
5542 * New remote packets
5545 Ignore the specified signals; pass them directly to the debugged program
5546 without stopping other threads or reporting them to GDB.
5548 qXfer:features:read:
5549 Read an XML target description from the target, which describes its
5554 Read or write contents of an spufs file on the target system. These
5555 packets are available only on the Cell/B.E. SPU architecture.
5557 qXfer:libraries:read:
5558 Report the loaded shared libraries. Combined with new "T" packet
5559 response, this packet allows GDB to debug shared libraries on
5560 targets where the operating system manages the list of loaded
5561 libraries (e.g. Windows and SymbianOS).
5565 Support for these obsolete configurations has been removed.
5573 i[34567]86-*-lynxos*
5574 i[34567]86-*-netware*
5575 i[34567]86-*-sco3.2v5*
5576 i[34567]86-*-sco3.2v4*
5578 i[34567]86-*-sysv4.2*
5581 i[34567]86-*-unixware2*
5582 i[34567]86-*-unixware*
5591 * Other removed features
5598 Various m68k-only ROM monitors.
5605 Various Renesas ROM monitors and debugging interfaces for SH and
5610 Support for a Macraigor serial interface to on-chip debugging.
5611 GDB does not directly support the newer parallel or USB
5616 A debug information format. The predecessor to DWARF 2 and
5617 DWARF 3, which are still supported.
5619 Support for the HP aCC compiler on HP-UX/PA-RISC
5621 SOM-encapsulated symbolic debugging information, automatic
5622 invocation of pxdb, and the aCC custom C++ ABI. This does not
5623 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5624 with aCC can still be debugged on an assembly level.
5626 MIPS ".pdr" sections
5628 A MIPS-specific format used to describe stack frame layout
5629 in debugging information.
5633 GDB could work with an older version of Guile to debug
5634 the interpreter and Scheme programs running in it.
5636 set mips stack-arg-size
5637 set mips saved-gpreg-size
5639 Use "set mips abi" to control parameter passing for MIPS.
5641 *** Changes in GDB 6.6
5646 Cell Broadband Engine SPU spu-elf
5648 * GDB can now be configured as a cross-debugger targeting native Windows
5649 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5650 running on a Windows system over TCP/IP to debug Windows programs.
5652 * The GDB remote stub, gdbserver, has been updated to support Windows and
5653 Cygwin debugging. Both single-threaded and multi-threaded programs are
5656 * The "set trust-readonly-sections" command works again. This command was
5657 broken in GDB 6.3, 6.4, and 6.5.
5659 * The "load" command now supports writing to flash memory, if the remote
5660 stub provides the required support.
5662 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5663 longer requires symbolic debug information (e.g. DWARF-2).
5668 unset substitute-path
5669 show substitute-path
5670 Manage a list of substitution rules that GDB uses to rewrite the name
5671 of the directories where the sources are located. This can be useful
5672 for instance when the sources were moved to a different location
5673 between compilation and debugging.
5677 Print each CLI command as it is executed. Each command is prefixed with
5678 a number of `+' symbols representing the nesting depth.
5679 The source command now has a `-v' option to enable the same feature.
5683 The ARM Demon monitor support (RDP protocol, "target rdp").
5685 Kernel Object Display, an embedded debugging feature which only worked with
5686 an obsolete version of Cisco IOS.
5688 The 'set download-write-size' and 'show download-write-size' commands.
5690 * New remote packets
5693 Tell a stub about GDB client features, and request remote target features.
5694 The first feature implemented is PacketSize, which allows the target to
5695 specify the size of packets it can handle - to minimize the number of
5696 packets required and improve performance when connected to a remote
5700 Fetch an OS auxilliary vector from the remote stub. This packet is a
5701 more efficient replacement for qPart:auxv:read.
5703 qXfer:memory-map:read:
5704 Fetch a memory map from the remote stub, including information about
5705 RAM, ROM, and flash memory devices.
5710 Erase and program a flash memory device.
5712 * Removed remote packets
5715 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5716 used it, and only gdbserver implemented it.
5718 *** Changes in GDB 6.5
5722 Renesas M32C/M16C m32c-elf
5724 Morpho Technologies ms1 ms1-elf
5728 init-if-undefined Initialize a convenience variable, but
5729 only if it doesn't already have a value.
5731 The following commands are presently only implemented for native GNU/Linux:
5733 checkpoint Save a snapshot of the program state.
5735 restart <n> Return the program state to a
5736 previously saved state.
5738 info checkpoints List currently saved checkpoints.
5740 delete-checkpoint <n> Delete a previously saved checkpoint.
5742 set|show detach-on-fork Tell gdb whether to detach from a newly
5743 forked process, or to keep debugging it.
5745 info forks List forks of the user program that
5746 are available to be debugged.
5748 fork <n> Switch to debugging one of several
5749 forks of the user program that are
5750 available to be debugged.
5752 delete-fork <n> Delete a fork from the list of forks
5753 that are available to be debugged (and
5754 kill the forked process).
5756 detach-fork <n> Delete a fork from the list of forks
5757 that are available to be debugged (and
5758 allow the process to continue).
5762 Morpho Technologies ms2 ms1-elf
5764 * Improved Windows host support
5766 GDB now builds as a cross debugger hosted on i686-mingw32, including
5767 native console support, and remote communications using either
5768 network sockets or serial ports.
5770 * Improved Modula-2 language support
5772 GDB can now print most types in the Modula-2 syntax. This includes:
5773 basic types, set types, record types, enumerated types, range types,
5774 pointer types and ARRAY types. Procedure var parameters are correctly
5775 printed and hexadecimal addresses and character constants are also
5776 written in the Modula-2 syntax. Best results can be obtained by using
5777 GNU Modula-2 together with the -gdwarf-2 command line option.
5781 The ARM rdi-share module.
5783 The Netware NLM debug server.
5785 *** Changes in GDB 6.4
5787 * New native configurations
5789 OpenBSD/arm arm*-*-openbsd*
5790 OpenBSD/mips64 mips64-*-openbsd*
5794 Morpho Technologies ms1 ms1-elf
5796 * New command line options
5798 --batch-silent As for --batch, but totally silent.
5799 --return-child-result The debugger will exist with the same value
5800 the child (debugged) program exited with.
5801 --eval-command COMMAND, -ex COMMAND
5802 Execute a single GDB CLI command. This may be
5803 specified multiple times and in conjunction
5804 with the --command (-x) option.
5806 * Deprecated commands removed
5808 The following commands, that were deprecated in 2000, have been
5812 set|show arm disassembly-flavor set|show arm disassembler
5813 othernames set arm disassembler
5814 set|show remotedebug set|show debug remote
5815 set|show archdebug set|show debug arch
5816 set|show eventdebug set|show debug event
5819 * New BSD user-level threads support
5821 It is now possible to debug programs using the user-level threads
5822 library on OpenBSD and FreeBSD. Currently supported (target)
5825 FreeBSD/amd64 x86_64-*-freebsd*
5826 FreeBSD/i386 i386-*-freebsd*
5827 OpenBSD/i386 i386-*-openbsd*
5829 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5830 are not yet supported.
5832 * New support for Matsushita MN10300 w/sim added
5833 (Work in progress). mn10300-elf.
5835 * REMOVED configurations and files
5837 VxWorks and the XDR protocol *-*-vxworks
5838 Motorola MCORE mcore-*-*
5839 National Semiconductor NS32000 ns32k-*-*
5841 * New "set print array-indexes" command
5843 After turning this setting "on", GDB prints the index of each element
5844 when displaying arrays. The default is "off" to preserve the previous
5847 * VAX floating point support
5849 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5851 * User-defined command support
5853 In addition to using $arg0..$arg9 for argument passing, it is now possible
5854 to use $argc to determine now many arguments have been passed. See the
5855 section on user-defined commands in the user manual for more information.
5857 *** Changes in GDB 6.3:
5859 * New command line option
5861 GDB now accepts -l followed by a number to set the timeout for remote
5864 * GDB works with GCC -feliminate-dwarf2-dups
5866 GDB now supports a more compact representation of DWARF-2 debug
5867 information using DW_FORM_ref_addr references. These are produced
5868 by GCC with the option -feliminate-dwarf2-dups and also by some
5869 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5870 to use -feliminate-dwarf2-dups.
5872 * Internationalization
5874 When supported by the host system, GDB will be built with
5875 internationalization (libintl). The task of marking up the sources is
5876 continued, we're looking forward to our first translation.
5880 Initial support for debugging programs compiled with the GNAT
5881 implementation of the Ada programming language has been integrated
5882 into GDB. In this release, support is limited to expression evaluation.
5884 * New native configurations
5886 GNU/Linux/m32r m32r-*-linux-gnu
5890 GDB's remote protocol now includes support for the 'p' packet. This
5891 packet is used to fetch individual registers from a remote inferior.
5893 * END-OF-LIFE registers[] compatibility module
5895 GDB's internal register infrastructure has been completely rewritten.
5896 The new infrastructure making possible the implementation of key new
5897 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5900 GDB 6.3 will be the last release to include the registers[]
5901 compatibility module that allowed out-of-date configurations to
5902 continue to work. This change directly impacts the following
5912 powerpc bdm protocol
5914 Unless there is activity to revive these configurations, they will be
5915 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5917 * OBSOLETE configurations and files
5919 Configurations that have been declared obsolete in this release have
5920 been commented out. Unless there is activity to revive these
5921 configurations, the next release of GDB will have their sources
5922 permanently REMOVED.
5931 *** Changes in GDB 6.2.1:
5933 * MIPS `break main; run' gave an heuristic-fence-post warning
5935 When attempting to run even a simple program, a warning about
5936 heuristic-fence-post being hit would be reported. This problem has
5939 * MIPS IRIX 'long double' crashed GDB
5941 When examining a long double variable, GDB would get a segmentation
5942 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5943 IRIX long double values).
5947 A bug in the VAX stack code was causing problems with the "next"
5948 command. This problem has been fixed.
5950 *** Changes in GDB 6.2:
5952 * Fix for ``many threads''
5954 On GNU/Linux systems that use the NPTL threads library, a program
5955 rapidly creating and deleting threads would confuse GDB leading to the
5958 ptrace: No such process.
5959 thread_db_get_info: cannot get thread info: generic error
5961 This problem has been fixed.
5963 * "-async" and "-noasync" options removed.
5965 Support for the broken "-noasync" option has been removed (it caused
5968 * New ``start'' command.
5970 This command runs the program until the beginning of the main procedure.
5972 * New BSD Kernel Data Access Library (libkvm) interface
5974 Using ``target kvm'' it is now possible to debug kernel core dumps and
5975 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5976 platforms. Currently supported (native-only) configurations are:
5978 FreeBSD/amd64 x86_64-*-freebsd*
5979 FreeBSD/i386 i?86-*-freebsd*
5980 NetBSD/i386 i?86-*-netbsd*
5981 NetBSD/m68k m68*-*-netbsd*
5982 NetBSD/sparc sparc-*-netbsd*
5983 OpenBSD/amd64 x86_64-*-openbsd*
5984 OpenBSD/i386 i?86-*-openbsd*
5985 OpenBSD/m68k m68*-openbsd*
5986 OpenBSD/sparc sparc-*-openbsd*
5988 * Signal trampoline code overhauled
5990 Many generic problems with GDB's signal handling code have been fixed.
5991 These include: backtraces through non-contiguous stacks; recognition
5992 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5993 call; backtrace through a signal trampoline; step into and out of
5994 signal handlers; and single-stepping in the signal trampoline.
5996 Please note that kernel bugs are a limiting factor here. These
5997 features have been shown to work on an s390 GNU/Linux system that
5998 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6000 * Cygwin support for DWARF 2 added.
6002 * New native configurations
6004 GNU/Linux/hppa hppa*-*-linux*
6005 OpenBSD/hppa hppa*-*-openbsd*
6006 OpenBSD/m68k m68*-*-openbsd*
6007 OpenBSD/m88k m88*-*-openbsd*
6008 OpenBSD/powerpc powerpc-*-openbsd*
6009 NetBSD/vax vax-*-netbsd*
6010 OpenBSD/vax vax-*-openbsd*
6012 * END-OF-LIFE frame compatibility module
6014 GDB's internal frame infrastructure has been completely rewritten.
6015 The new infrastructure making it possible to support key new features
6016 including DWARF 2 Call Frame Information. To aid in the task of
6017 migrating old configurations to this new infrastructure, a
6018 compatibility module, that allowed old configurations to continue to
6019 work, was also included.
6021 GDB 6.2 will be the last release to include this frame compatibility
6022 module. This change directly impacts the following configurations:
6032 Unless there is activity to revive these configurations, they will be
6033 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6035 * REMOVED configurations and files
6037 Sun 3, running SunOS 3 m68*-*-sunos3*
6038 Sun 3, running SunOS 4 m68*-*-sunos4*
6039 Sun 2, running SunOS 3 m68000-*-sunos3*
6040 Sun 2, running SunOS 4 m68000-*-sunos4*
6041 Motorola 680x0 running LynxOS m68*-*-lynxos*
6042 AT&T 3b1/Unix pc m68*-att-*
6043 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6044 decstation mips-dec-* mips-little-*
6045 riscos mips-*-riscos* mips-*-sysv*
6046 sonymips mips-sony-*
6047 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6049 *** Changes in GDB 6.1.1:
6051 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6053 The TUI (Text-mode User Interface) is now built as part of a default
6054 GDB configuration. It is enabled by either selecting the TUI with the
6055 command line option "-i=tui" or by running the separate "gdbtui"
6056 program. For more information on the TUI, see the manual "Debugging
6059 * Pending breakpoint support (also included in GDB 6.1)
6061 Support has been added to allow you to specify breakpoints in shared
6062 libraries that have not yet been loaded. If a breakpoint location
6063 cannot be found, and the "breakpoint pending" option is set to auto,
6064 GDB queries you if you wish to make the breakpoint pending on a future
6065 shared-library load. If and when GDB resolves the breakpoint symbol,
6066 the pending breakpoint is removed as one or more regular breakpoints
6069 Pending breakpoints are very useful for GCJ Java debugging.
6071 * Fixed ISO-C build problems
6073 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6074 non ISO-C code that stopped them being built using a more strict ISO-C
6075 compiler (e.g., IBM's C compiler).
6077 * Fixed build problem on IRIX 5
6079 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6080 wasn't able to compile compile on an IRIX 5 system.
6082 * Added execute permission to gdb/gdbserver/configure
6084 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6085 permission. This bug would cause configure to fail on a number of
6086 systems (Solaris, IRIX). Ref: server/519.
6088 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6090 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6091 has been updated to use constant array sizes.
6093 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6095 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6096 its generated DWARF Call Frame Info. This encoding was causing GDB to
6097 panic, that panic has been fixed. Ref: gdb/1628.
6099 * Fixed a problem when examining parameters in shared library code.
6101 When examining parameters in optimized shared library code generated
6102 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6103 not available''. GDB now correctly displays the variable's value.
6105 *** Changes in GDB 6.1:
6107 * Removed --with-mmalloc
6109 Support for the mmalloc memory manager has been removed, as it
6110 conflicted with the internal gdb byte cache.
6112 * Changes in AMD64 configurations
6114 The AMD64 target now includes the %cs and %ss registers. As a result
6115 the AMD64 remote protocol has changed; this affects the floating-point
6116 and SSE registers. If you rely on those registers for your debugging,
6117 you should upgrade gdbserver on the remote side.
6119 * Revised SPARC target
6121 The SPARC target has been completely revised, incorporating the
6122 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6123 support for LynxOS and SunOS 4 has been dropped. Calling functions
6124 from within GDB on operating systems with a non-executable stack
6125 (Solaris, OpenBSD) now works.
6129 GDB has a new C++ demangler which does a better job on the mangled
6130 names generated by current versions of g++. It also runs faster, so
6131 with this and other changes gdb should now start faster on large C++
6134 * DWARF 2 Location Expressions
6136 GDB support for location expressions has been extended to support function
6137 arguments and frame bases. Older versions of GDB could crash when they
6140 * C++ nested types and namespaces
6142 GDB's support for nested types and namespaces in C++ has been
6143 improved, especially if you use the DWARF 2 debugging format. (This
6144 is the default for recent versions of GCC on most platforms.)
6145 Specifically, if you have a class "Inner" defined within a class or
6146 namespace "Outer", then GDB realizes that the class's name is
6147 "Outer::Inner", not simply "Inner". This should greatly reduce the
6148 frequency of complaints about not finding RTTI symbols. In addition,
6149 if you are stopped at inside of a function defined within a namespace,
6150 GDB modifies its name lookup accordingly.
6152 * New native configurations
6154 NetBSD/amd64 x86_64-*-netbsd*
6155 OpenBSD/amd64 x86_64-*-openbsd*
6156 OpenBSD/alpha alpha*-*-openbsd*
6157 OpenBSD/sparc sparc-*-openbsd*
6158 OpenBSD/sparc64 sparc64-*-openbsd*
6160 * New debugging protocols
6162 M32R with SDI protocol m32r-*-elf*
6164 * "set prompt-escape-char" command deleted.
6166 The command "set prompt-escape-char" has been deleted. This command,
6167 and its very obscure effect on GDB's prompt, was never documented,
6168 tested, nor mentioned in the NEWS file.
6170 * OBSOLETE configurations and files
6172 Configurations that have been declared obsolete in this release have
6173 been commented out. Unless there is activity to revive these
6174 configurations, the next release of GDB will have their sources
6175 permanently REMOVED.
6177 Sun 3, running SunOS 3 m68*-*-sunos3*
6178 Sun 3, running SunOS 4 m68*-*-sunos4*
6179 Sun 2, running SunOS 3 m68000-*-sunos3*
6180 Sun 2, running SunOS 4 m68000-*-sunos4*
6181 Motorola 680x0 running LynxOS m68*-*-lynxos*
6182 AT&T 3b1/Unix pc m68*-att-*
6183 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6184 decstation mips-dec-* mips-little-*
6185 riscos mips-*-riscos* mips-*-sysv*
6186 sonymips mips-sony-*
6187 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6189 * REMOVED configurations and files
6191 SGI Irix-4.x mips-sgi-irix4 or iris4
6192 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6193 Z8000 simulator z8k-zilog-none or z8ksim
6194 Matsushita MN10200 w/simulator mn10200-*-*
6195 H8/500 simulator h8500-hitachi-hms or h8500hms
6196 HP/PA running BSD hppa*-*-bsd*
6197 HP/PA running OSF/1 hppa*-*-osf*
6198 HP/PA Pro target hppa*-*-pro*
6199 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6200 386BSD i[3456]86-*-bsd*
6201 Sequent family i[3456]86-sequent-sysv4*
6202 i[3456]86-sequent-sysv*
6203 i[3456]86-sequent-bsd*
6204 SPARC running LynxOS sparc-*-lynxos*
6205 SPARC running SunOS 4 sparc-*-sunos4*
6206 Tsqware Sparclet sparclet-*-*
6207 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6209 *** Changes in GDB 6.0:
6213 Support for debugging the Objective-C programming language has been
6214 integrated into GDB.
6216 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6218 DWARF 2's Call Frame Information makes available compiler generated
6219 information that more exactly describes the program's run-time stack.
6220 By using this information, GDB is able to provide more robust stack
6223 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6224 have been updated to use a new backtrace mechanism which includes
6225 DWARF 2 CFI support.
6229 GDB's remote protocol has been extended to include support for hosted
6230 file I/O (where the remote target uses GDB's file system). See GDB's
6231 remote protocol documentation for details.
6233 * All targets using the new architecture framework.
6235 All of GDB's targets have been updated to use the new internal
6236 architecture framework. The way is now open for future GDB releases
6237 to include cross-architecture native debugging support (i386 on amd64,
6240 * GNU/Linux's Thread Local Storage (TLS)
6242 GDB now includes support for for the GNU/Linux implementation of
6243 per-thread variables.
6245 * GNU/Linux's Native POSIX Thread Library (NPTL)
6247 GDB's thread code has been updated to work with either the new
6248 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6250 * Separate debug info.
6252 GDB, in conjunction with BINUTILS, now supports a mechanism for
6253 automatically loading debug information from a separate file. Instead
6254 of shipping full debug and non-debug versions of system libraries,
6255 system integrators can now instead ship just the stripped libraries
6256 and optional debug files.
6258 * DWARF 2 Location Expressions
6260 DWARF 2 Location Expressions allow the compiler to more completely
6261 describe the location of variables (even in optimized code) to the
6264 GDB now includes preliminary support for location expressions (support
6265 for DW_OP_piece is still missing).
6269 A number of long standing bugs that caused GDB to die while starting a
6270 Java application have been fixed. GDB's Java support is now
6271 considered "useable".
6273 * GNU/Linux support for fork, vfork, and exec.
6275 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6276 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6279 * GDB supports logging output to a file
6281 There are two new commands, "set logging" and "show logging", which can be
6282 used to capture GDB's output to a file.
6284 * The meaning of "detach" has changed for gdbserver
6286 The "detach" command will now resume the application, as documented. To
6287 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6290 * d10v, m68hc11 `regs' command deprecated
6292 The `info registers' command has been updated so that it displays the
6293 registers using a format identical to the old `regs' command.
6297 A new command, "maint set profile on/off", has been added. This command can
6298 be used to enable or disable profiling while running GDB, to profile a
6299 session or a set of commands. In addition there is a new configure switch,
6300 "--enable-profiling", which will cause GDB to be compiled with profiling
6301 data, for more informative profiling results.
6303 * Default MI syntax changed to "mi2".
6305 The default MI (machine interface) syntax, enabled by the command line
6306 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6307 "mi1", can be enabled by specifying the option "-i=mi1".
6309 Support for the original "mi0" syntax (included in GDB 5.0) has been
6312 Fix for gdb/192: removed extraneous space when displaying frame level.
6313 Fix for gdb/672: update changelist is now output in mi list format.
6314 Fix for gdb/702: a -var-assign that updates the value now shows up
6315 in a subsequent -var-update.
6317 * New native configurations.
6319 FreeBSD/amd64 x86_64-*-freebsd*
6321 * Multi-arched targets.
6323 HP/PA HPUX11 hppa*-*-hpux*
6324 Renesas M32R/D w/simulator m32r-*-elf*
6326 * OBSOLETE configurations and files
6328 Configurations that have been declared obsolete in this release have
6329 been commented out. Unless there is activity to revive these
6330 configurations, the next release of GDB will have their sources
6331 permanently REMOVED.
6333 Z8000 simulator z8k-zilog-none or z8ksim
6334 Matsushita MN10200 w/simulator mn10200-*-*
6335 H8/500 simulator h8500-hitachi-hms or h8500hms
6336 HP/PA running BSD hppa*-*-bsd*
6337 HP/PA running OSF/1 hppa*-*-osf*
6338 HP/PA Pro target hppa*-*-pro*
6339 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6340 Sequent family i[3456]86-sequent-sysv4*
6341 i[3456]86-sequent-sysv*
6342 i[3456]86-sequent-bsd*
6343 Tsqware Sparclet sparclet-*-*
6344 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6346 * REMOVED configurations and files
6349 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6350 IBM AIX PS/2 i[3456]86-*-aix
6351 i386 running Mach 3.0 i[3456]86-*-mach3*
6352 i386 running Mach i[3456]86-*-mach*
6353 i386 running OSF/1 i[3456]86-*osf1mk*
6354 HP/Apollo 68k Family m68*-apollo*-sysv*,
6356 m68*-hp-bsd*, m68*-hp-hpux*
6357 Argonaut Risc Chip (ARC) arc-*-*
6358 Mitsubishi D30V d30v-*-*
6359 Fujitsu FR30 fr30-*-elf*
6360 OS/9000 i[34]86-*-os9k
6361 I960 with MON960 i960-*-coff
6363 * MIPS $fp behavior changed
6365 The convenience variable $fp, for the MIPS, now consistently returns
6366 the address of the current frame's base. Previously, depending on the
6367 context, $fp could refer to either $sp or the current frame's base
6368 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6369 The GNU Source-Level Debugger''.
6371 *** Changes in GDB 5.3:
6373 * GNU/Linux shared library multi-threaded performance improved.
6375 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6376 `/proc', in preference to `ptrace' for memory reads. This may result
6377 in an improvement in the start-up time of multi-threaded, shared
6378 library applications when run under GDB. One GDB user writes: ``loads
6379 shared libs like mad''.
6381 * ``gdbserver'' now supports multi-threaded applications on some targets
6383 Support for debugging multi-threaded applications which use
6384 the GNU/Linux LinuxThreads package has been added for
6385 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6386 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6388 * GDB now supports C/C++ preprocessor macros.
6390 GDB now expands preprocessor macro invocations in C/C++ expressions,
6391 and provides various commands for showing macro definitions and how
6394 The new command `macro expand EXPRESSION' expands any macro
6395 invocations in expression, and shows the result.
6397 The new command `show macro MACRO-NAME' shows the definition of the
6398 macro named MACRO-NAME, and where it was defined.
6400 Most compilers don't include information about macros in the debugging
6401 information by default. In GCC 3.1, for example, you need to compile
6402 your program with the options `-gdwarf-2 -g3'. If the macro
6403 information is present in the executable, GDB will read it.
6405 * Multi-arched targets.
6407 DEC Alpha (partial) alpha*-*-*
6408 DEC VAX (partial) vax-*-*
6410 National Semiconductor NS32000 (partial) ns32k-*-*
6411 Motorola 68000 (partial) m68k-*-*
6412 Motorola MCORE mcore-*-*
6416 Fujitsu FRV architecture added by Red Hat frv*-*-*
6419 * New native configurations
6421 Alpha NetBSD alpha*-*-netbsd*
6422 SH NetBSD sh*-*-netbsdelf*
6423 MIPS NetBSD mips*-*-netbsd*
6424 UltraSPARC NetBSD sparc64-*-netbsd*
6426 * OBSOLETE configurations and files
6428 Configurations that have been declared obsolete in this release have
6429 been commented out. Unless there is activity to revive these
6430 configurations, the next release of GDB will have their sources
6431 permanently REMOVED.
6433 Mitsubishi D30V d30v-*-*
6434 OS/9000 i[34]86-*-os9k
6435 IBM AIX PS/2 i[3456]86-*-aix
6436 Fujitsu FR30 fr30-*-elf*
6437 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6438 Argonaut Risc Chip (ARC) arc-*-*
6439 i386 running Mach 3.0 i[3456]86-*-mach3*
6440 i386 running Mach i[3456]86-*-mach*
6441 i386 running OSF/1 i[3456]86-*osf1mk*
6442 HP/Apollo 68k Family m68*-apollo*-sysv*,
6444 m68*-hp-bsd*, m68*-hp-hpux*
6445 I960 with MON960 i960-*-coff
6447 * OBSOLETE languages
6449 CHILL, a Pascal like language used by telecommunications companies.
6451 * REMOVED configurations and files
6453 AMD 29k family via UDI a29k-amd-udi, udi29k
6454 A29K VxWorks a29k-*-vxworks
6455 AMD 29000 embedded, using EBMON a29k-none-none
6456 AMD 29000 embedded with COFF a29k-none-coff
6457 AMD 29000 embedded with a.out a29k-none-aout
6459 testsuite/gdb.hp/gdb.threads-hp/ directory
6461 * New command "set max-user-call-depth <nnn>"
6463 This command allows the user to limit the call depth of user-defined
6464 commands. The default is 1024.
6466 * Changes in FreeBSD/i386 native debugging.
6468 Support for the "generate-core-file" has been added.
6470 * New commands "dump", "append", and "restore".
6472 These commands allow data to be copied from target memory
6473 to a bfd-format or binary file (dump and append), and back
6474 from a file into memory (restore).
6476 * Improved "next/step" support on multi-processor Alpha Tru64.
6478 The previous single-step mechanism could cause unpredictable problems,
6479 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6480 of a software single-step mechanism prevents this.
6482 *** Changes in GDB 5.2.1:
6490 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6491 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6492 Fix, by Joel Brobecker imported from mainline.
6494 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6495 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6496 Fix, by Fred Fish, imported from mainline.
6498 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6499 Surprisingly enough, it works now.
6500 By Michal Ludvig, imported from mainline.
6502 i386 hardware watchpoint support:
6503 avoid misses on second run for some targets.
6504 By Pierre Muller, imported from mainline.
6506 *** Changes in GDB 5.2:
6508 * New command "set trust-readonly-sections on[off]".
6510 This command is a hint that tells gdb that read-only sections
6511 really are read-only (ie. that their contents will not change).
6512 In this mode, gdb will go to the object file rather than the
6513 target to read memory from read-only sections (such as ".text").
6514 This can be a significant performance improvement on some
6515 (notably embedded) targets.
6517 * New command "generate-core-file" (or "gcore").
6519 This new gdb command allows the user to drop a core file of the child
6520 process state at any time. So far it's been implemented only for
6521 GNU/Linux and Solaris, but should be relatively easily ported to other
6522 hosts. Argument is core file name (defaults to core.<pid>).
6524 * New command line option
6526 GDB now accepts --pid or -p followed by a process id.
6528 * Change in command line behavior -- corefiles vs. process ids.
6530 There is a subtle behavior in the way in which GDB handles
6531 command line arguments. The first non-flag argument is always
6532 a program to debug, but the second non-flag argument may either
6533 be a corefile or a process id. Previously, GDB would attempt to
6534 open the second argument as a corefile, and if that failed, would
6535 issue a superfluous error message and then attempt to attach it as
6536 a process. Now, if the second argument begins with a non-digit,
6537 it will be treated as a corefile. If it begins with a digit,
6538 GDB will attempt to attach it as a process, and if no such process
6539 is found, will then attempt to open it as a corefile.
6541 * Changes in ARM configurations.
6543 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6544 configuration is fully multi-arch.
6546 * New native configurations
6548 ARM NetBSD arm*-*-netbsd*
6549 x86 OpenBSD i[3456]86-*-openbsd*
6550 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6551 Sparc64 running FreeBSD sparc64-*-freebsd*
6555 Sanyo XStormy16 xstormy16-elf
6557 * OBSOLETE configurations and files
6559 Configurations that have been declared obsolete in this release have
6560 been commented out. Unless there is activity to revive these
6561 configurations, the next release of GDB will have their sources
6562 permanently REMOVED.
6564 AMD 29k family via UDI a29k-amd-udi, udi29k
6565 A29K VxWorks a29k-*-vxworks
6566 AMD 29000 embedded, using EBMON a29k-none-none
6567 AMD 29000 embedded with COFF a29k-none-coff
6568 AMD 29000 embedded with a.out a29k-none-aout
6570 testsuite/gdb.hp/gdb.threads-hp/ directory
6572 * REMOVED configurations and files
6574 TI TMS320C80 tic80-*-*
6576 PowerPC Solaris powerpcle-*-solaris*
6577 PowerPC Windows NT powerpcle-*-cygwin32
6578 PowerPC Netware powerpc-*-netware*
6579 Harris/CXUX m88k m88*-harris-cxux*
6580 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6581 ns32k-utek-sysv* ns32k-utek-*
6582 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6583 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6584 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6585 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6586 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6588 * Changes to command line processing
6590 The new `--args' feature can be used to specify command-line arguments
6591 for the inferior from gdb's command line.
6593 * Changes to key bindings
6595 There is a new `operate-and-get-next' function bound to `C-o'.
6597 *** Changes in GDB 5.1.1
6599 Fix compile problem on DJGPP.
6601 Fix a problem with floating-point registers on the i386 being
6604 Fix to stop GDB crashing on .debug_str debug info.
6606 Numerous documentation fixes.
6608 Numerous testsuite fixes.
6610 *** Changes in GDB 5.1:
6612 * New native configurations
6614 Alpha FreeBSD alpha*-*-freebsd*
6615 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6616 MIPS GNU/Linux mips*-*-linux*
6617 MIPS SGI Irix 6.x mips*-sgi-irix6*
6618 ia64 AIX ia64-*-aix*
6619 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6623 Motorola 68HC11 and 68HC12 m68hc11-elf
6625 UltraSparc running GNU/Linux sparc64-*-linux*
6627 * OBSOLETE configurations and files
6629 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6630 Harris/CXUX m88k m88*-harris-cxux*
6631 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6632 ns32k-utek-sysv* ns32k-utek-*
6633 TI TMS320C80 tic80-*-*
6635 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6636 PowerPC Solaris powerpcle-*-solaris*
6637 PowerPC Windows NT powerpcle-*-cygwin32
6638 PowerPC Netware powerpc-*-netware*
6639 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6640 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6641 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6642 Apple Macintosh (MPW) host N/A
6644 stuff.c (Program to stuff files into a specially prepared space in kdb)
6645 kdb-start.c (Main loop for the standalone kernel debugger)
6647 Configurations that have been declared obsolete in this release have
6648 been commented out. Unless there is activity to revive these
6649 configurations, the next release of GDB will have their sources
6650 permanently REMOVED.
6652 * REMOVED configurations and files
6654 Altos 3068 m68*-altos-*
6655 Convex c1-*-*, c2-*-*
6657 ARM RISCix arm-*-* (as host)
6661 * GDB has been converted to ISO C.
6663 GDB's source code has been converted to ISO C. In particular, the
6664 sources are fully protoized, and rely on standard headers being
6669 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6671 * The MI enabled by default.
6673 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6674 revised and enabled by default. Packages which use GDB as a debugging
6675 engine behind a UI or another front end are encouraged to switch to
6676 using the GDB/MI interface, instead of the old annotations interface
6677 which is now deprecated.
6679 * Support for debugging Pascal programs.
6681 GDB now includes support for debugging Pascal programs. The following
6682 main features are supported:
6684 - Pascal-specific data types such as sets;
6686 - automatic recognition of Pascal sources based on file-name
6689 - Pascal-style display of data types, variables, and functions;
6691 - a Pascal expression parser.
6693 However, some important features are not yet supported.
6695 - Pascal string operations are not supported at all;
6697 - there are some problems with boolean types;
6699 - Pascal type hexadecimal constants are not supported
6700 because they conflict with the internal variables format;
6702 - support for Pascal objects and classes is not full yet;
6704 - unlike Pascal, GDB is case-sensitive for symbol names.
6706 * Changes in completion.
6708 Commands such as `shell', `run' and `set args', which pass arguments
6709 to inferior programs, now complete on file names, similar to what
6710 users expect at the shell prompt.
6712 Commands which accept locations, such as `disassemble', `print',
6713 `breakpoint', `until', etc. now complete on filenames as well as
6714 program symbols. Thus, if you type "break foob TAB", and the source
6715 files linked into the programs include `foobar.c', that file name will
6716 be one of the candidates for completion. However, file names are not
6717 considered for completion after you typed a colon that delimits a file
6718 name from a name of a function in that file, as in "break foo.c:bar".
6720 `set demangle-style' completes on available demangling styles.
6722 * New platform-independent commands:
6724 It is now possible to define a post-hook for a command as well as a
6725 hook that runs before the command. For more details, see the
6726 documentation of `hookpost' in the GDB manual.
6728 * Changes in GNU/Linux native debugging.
6730 Support for debugging multi-threaded programs has been completely
6731 revised for all platforms except m68k and sparc. You can now debug as
6732 many threads as your system allows you to have.
6734 Attach/detach is supported for multi-threaded programs.
6736 Support for SSE registers was added for x86. This doesn't work for
6737 multi-threaded programs though.
6739 * Changes in MIPS configurations.
6741 Multi-arch support is enabled for all MIPS configurations.
6743 GDB can now be built as native debugger on SGI Irix 6.x systems for
6744 debugging n32 executables. (Debugging 64-bit executables is not yet
6747 * Unified support for hardware watchpoints in all x86 configurations.
6749 Most (if not all) native x86 configurations support hardware-assisted
6750 breakpoints and watchpoints in a unified manner. This support
6751 implements debug register sharing between watchpoints, which allows to
6752 put a virtually infinite number of watchpoints on the same address,
6753 and also supports watching regions up to 16 bytes with several debug
6756 The new maintenance command `maintenance show-debug-regs' toggles
6757 debugging print-outs in functions that insert, remove, and test
6758 watchpoints and hardware breakpoints.
6760 * Changes in the DJGPP native configuration.
6762 New command ``info dos sysinfo'' displays assorted information about
6763 the CPU, OS, memory, and DPMI server.
6765 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6766 display information about segment descriptors stored in GDT, LDT, and
6769 New commands ``info dos pde'' and ``info dos pte'' display entries
6770 from Page Directory and Page Tables (for now works with CWSDPMI only).
6771 New command ``info dos address-pte'' displays the Page Table entry for
6772 a given linear address.
6774 GDB can now pass command lines longer than 126 characters to the
6775 program being debugged (requires an update to the libdbg.a library
6776 which is part of the DJGPP development kit).
6778 DWARF2 debug info is now supported.
6780 It is now possible to `step' and `next' through calls to `longjmp'.
6782 * Changes in documentation.
6784 All GDB documentation was converted to GFDL, the GNU Free
6785 Documentation License.
6787 Tracepoints-related commands are now fully documented in the GDB
6790 TUI, the Text-mode User Interface, is now documented in the manual.
6792 Tracepoints-related commands are now fully documented in the GDB
6795 The "GDB Internals" manual now has an index. It also includes
6796 documentation of `ui_out' functions, GDB coding standards, x86
6797 hardware watchpoints, and memory region attributes.
6799 * GDB's version number moved to ``version.in''
6801 The Makefile variable VERSION has been replaced by the file
6802 ``version.in''. People creating GDB distributions should update the
6803 contents of this file.
6807 GUD support is now a standard part of the EMACS distribution.
6809 *** Changes in GDB 5.0:
6811 * Improved support for debugging FP programs on x86 targets
6813 Unified and much-improved support for debugging floating-point
6814 programs on all x86 targets. In particular, ``info float'' now
6815 displays the FP registers in the same format on all x86 targets, with
6816 greater level of detail.
6818 * Improvements and bugfixes in hardware-assisted watchpoints
6820 It is now possible to watch array elements, struct members, and
6821 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6822 on x86 targets no longer erroneously trigger when the address is
6825 * Improvements in the native DJGPP version of GDB
6827 The distribution now includes all the scripts and auxiliary files
6828 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6829 machines ``out of the box''.
6831 The DJGPP version can now debug programs that use signals. It is
6832 possible to catch signals that happened in the debuggee, deliver
6833 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6834 would kill the program being debugged.) Programs that hook hardware
6835 interrupts (keyboard, timer, etc.) can also be debugged.
6837 It is now possible to debug DJGPP programs that redirect their
6838 standard handles or switch them to raw (as opposed to cooked) mode, or
6839 even close them. The command ``run < foo > bar'' works as expected,
6840 and ``info terminal'' reports useful information about the debuggee's
6841 terminal, including raw/cooked mode, redirection, etc.
6843 The DJGPP version now uses termios functions for console I/O, which
6844 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6847 DOS-style file names with drive letters are now fully supported by
6850 It is now possible to debug DJGPP programs that switch their working
6851 directory. It is also possible to rerun the debuggee any number of
6852 times without restarting GDB; thus, you can use the same setup,
6853 breakpoints, etc. for many debugging sessions.
6855 * New native configurations
6857 ARM GNU/Linux arm*-*-linux*
6858 PowerPC GNU/Linux powerpc-*-linux*
6862 Motorola MCore mcore-*-*
6863 x86 VxWorks i[3456]86-*-vxworks*
6864 PowerPC VxWorks powerpc-*-vxworks*
6865 TI TMS320C80 tic80-*-*
6867 * OBSOLETE configurations
6869 Altos 3068 m68*-altos-*
6870 Convex c1-*-*, c2-*-*
6872 ARM RISCix arm-*-* (as host)
6875 Configurations that have been declared obsolete will be commented out,
6876 but the code will be left in place. If there is no activity to revive
6877 these configurations before the next release of GDB, the sources will
6878 be permanently REMOVED.
6880 * Gould support removed
6882 Support for the Gould PowerNode and NP1 has been removed.
6884 * New features for SVR4
6886 On SVR4 native platforms (such as Solaris), if you attach to a process
6887 without first loading a symbol file, GDB will now attempt to locate and
6888 load symbols from the running process's executable file.
6890 * Many C++ enhancements
6892 C++ support has been greatly improved. Overload resolution now works properly
6893 in almost all cases. RTTI support is on the way.
6895 * Remote targets can connect to a sub-program
6897 A popen(3) style serial-device has been added. This device starts a
6898 sub-process (such as a stand-alone simulator) and then communicates
6899 with that. The sub-program to run is specified using the syntax
6900 ``|<program> <args>'' vis:
6902 (gdb) set remotedebug 1
6903 (gdb) target extended-remote |mn10300-elf-sim program-args
6905 * MIPS 64 remote protocol
6907 A long standing bug in the mips64 remote protocol where by GDB
6908 expected certain 32 bit registers (ex SR) to be transfered as 32
6909 instead of 64 bits has been fixed.
6911 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6912 added to provide backward compatibility with older versions of GDB.
6914 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6916 The command ``set remotebinarydownload'' command has been replaced by
6917 ``set remote X-packet''. Other commands in ``set remote'' family
6918 include ``set remote P-packet''.
6920 * Breakpoint commands accept ranges.
6922 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6923 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6924 ``tracepoint passcount'' also accepts a range of tracepoints.
6926 * ``apropos'' command added.
6928 The ``apropos'' command searches through command names and
6929 documentation strings, printing out matches, making it much easier to
6930 try to find a command that does what you are looking for.
6934 A new machine oriented interface (MI) has been added to GDB. This
6935 interface is designed for debug environments running GDB as a separate
6936 process. This is part of the long term libGDB project. See the
6937 "GDB/MI" chapter of the GDB manual for further information. It can be
6938 enabled by configuring with:
6940 .../configure --enable-gdbmi
6942 *** Changes in GDB-4.18:
6944 * New native configurations
6946 HP-UX 10.20 hppa*-*-hpux10.20
6947 HP-UX 11.x hppa*-*-hpux11.0*
6948 M68K GNU/Linux m68*-*-linux*
6952 Fujitsu FR30 fr30-*-elf*
6953 Intel StrongARM strongarm-*-*
6954 Mitsubishi D30V d30v-*-*
6956 * OBSOLETE configurations
6958 Gould PowerNode, NP1 np1-*-*, pn-*-*
6960 Configurations that have been declared obsolete will be commented out,
6961 but the code will be left in place. If there is no activity to revive
6962 these configurations before the next release of GDB, the sources will
6963 be permanently REMOVED.
6967 As a compatibility experiment, GDB's source files buildsym.h and
6968 buildsym.c have been converted to pure standard C, no longer
6969 containing any K&R compatibility code. We believe that all systems in
6970 use today either come with a standard C compiler, or have a GCC port
6971 available. If this is not true, please report the affected
6972 configuration to bug-gdb@gnu.org immediately. See the README file for
6973 information about getting a standard C compiler if you don't have one
6978 GDB now uses readline 2.2.
6980 * set extension-language
6982 You can now control the mapping between filename extensions and source
6983 languages by using the `set extension-language' command. For instance,
6984 you can ask GDB to treat .c files as C++ by saying
6985 set extension-language .c c++
6986 The command `info extensions' lists all of the recognized extensions
6987 and their associated languages.
6989 * Setting processor type for PowerPC and RS/6000
6991 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6992 you can use the `set processor' command to specify what variant of the
6993 PowerPC family you are debugging. The command
6997 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6998 following PowerPC and RS6000 variants:
7000 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7001 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7003 403GC IBM PowerPC 403GC
7004 505 Motorola PowerPC 505
7005 860 Motorola PowerPC 860 or 850
7006 601 Motorola PowerPC 601
7007 602 Motorola PowerPC 602
7008 603 Motorola/IBM PowerPC 603 or 603e
7009 604 Motorola PowerPC 604 or 604e
7010 750 Motorola/IBM PowerPC 750 or 750
7012 At the moment, this command just tells GDB what to name the
7013 special-purpose processor registers. Since almost all the affected
7014 registers are inaccessible to user-level programs, this command is
7015 only useful for remote debugging in its present form.
7019 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7020 more extensive support for HP-UX. Added features include shared
7021 library support, kernel threads and hardware watchpoints for 11.00,
7022 support for HP's ANSI C and C++ compilers, and a compatibility mode
7023 for xdb and dbx commands.
7027 HP's donation includes the new concept of catchpoints, which is a
7028 generalization of the old catch command. On HP-UX, it is now possible
7029 to catch exec, fork, and vfork, as well as library loading.
7031 This means that the existing catch command has changed; its first
7032 argument now specifies the type of catch to be set up. See the
7033 output of "help catch" for a list of catchpoint types.
7035 * Debugging across forks
7037 On HP-UX, you can choose which process to debug when a fork() happens
7042 HP has donated a curses-based terminal user interface (TUI). To get
7043 it, build with --enable-tui. Although this can be enabled for any
7044 configuration, at present it only works for native HP debugging.
7046 * GDB remote protocol additions
7048 A new protocol packet 'X' that writes binary data is now available.
7049 Default behavior is to try 'X', then drop back to 'M' if the stub
7050 fails to respond. The settable variable `remotebinarydownload'
7051 allows explicit control over the use of 'X'.
7053 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7054 full 64-bit address. The command
7056 set remoteaddresssize 32
7058 can be used to revert to the old behaviour. For existing remote stubs
7059 the change should not be noticed, as the additional address information
7062 In order to assist in debugging stubs, you may use the maintenance
7063 command `packet' to send any text string to the stub. For instance,
7065 maint packet heythere
7067 sends the packet "$heythere#<checksum>". Note that it is very easy to
7068 disrupt a debugging session by sending the wrong packet at the wrong
7071 The compare-sections command allows you to compare section data on the
7072 target to what is in the executable file without uploading or
7073 downloading, by comparing CRC checksums.
7075 * Tracing can collect general expressions
7077 You may now collect general expressions at tracepoints. This requires
7078 further additions to the target-side stub; see tracepoint.c and
7079 doc/agentexpr.texi for further details.
7081 * mask-address variable for Mips
7083 For Mips targets, you may control the zeroing of the upper 32 bits of
7084 a 64-bit address by entering `set mask-address on'. This is mainly
7085 of interest to users of embedded R4xxx and R5xxx processors.
7087 * Higher serial baud rates
7089 GDB's serial code now allows you to specify baud rates 57600, 115200,
7090 230400, and 460800 baud. (Note that your host system may not be able
7091 to achieve all of these rates.)
7095 The i960 configuration now includes an initial implementation of a
7096 builtin simulator, contributed by Jim Wilson.
7099 *** Changes in GDB-4.17:
7101 * New native configurations
7103 Alpha GNU/Linux alpha*-*-linux*
7104 Unixware 2.x i[3456]86-unixware2*
7105 Irix 6.x mips*-sgi-irix6*
7106 PowerPC GNU/Linux powerpc-*-linux*
7107 PowerPC Solaris powerpcle-*-solaris*
7108 Sparc GNU/Linux sparc-*-linux*
7109 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7113 Argonaut Risc Chip (ARC) arc-*-*
7114 Hitachi H8/300S h8300*-*-*
7115 Matsushita MN10200 w/simulator mn10200-*-*
7116 Matsushita MN10300 w/simulator mn10300-*-*
7117 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7118 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7119 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7120 Mitsubishi D10V w/simulator d10v-*-*
7121 Mitsubishi M32R/D w/simulator m32r-*-elf*
7122 Tsqware Sparclet sparclet-*-*
7123 NEC V850 w/simulator v850-*-*
7125 * New debugging protocols
7127 ARM with RDI protocol arm*-*-*
7128 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7129 DDB and LSI variants of PMON protocol mips*-*-*
7130 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7131 PowerPC with SDS protocol powerpc{,le}-*-eabi
7132 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7136 All configurations can now understand and use the DWARF 2 debugging
7137 format. The choice is automatic, if the symbol file contains DWARF 2
7142 GDB now includes basic Java language support. This support is
7143 only useful with Java compilers that produce native machine code.
7145 * solib-absolute-prefix and solib-search-path
7147 For SunOS and SVR4 shared libraries, you may now set the prefix for
7148 loading absolute shared library symbol files, and the search path for
7149 locating non-absolute shared library symbol files.
7151 * Live range splitting
7153 GDB can now effectively debug code for which GCC has performed live
7154 range splitting as part of its optimization. See gdb/doc/LRS for
7155 more details on the expected format of the stabs information.
7159 GDB's support for the GNU Hurd, including thread debugging, has been
7160 updated to work with current versions of the Hurd.
7164 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7165 instruction set. ARM GDB automatically detects when Thumb
7166 instructions are in use, and adjusts disassembly and backtracing
7171 GDB's MIPS target configurations now handle the MIP16 16-bit
7176 GDB now includes support for overlays; if an executable has been
7177 linked such that multiple sections are based at the same address, GDB
7178 will decide which section to use for symbolic info. You can choose to
7179 control the decision manually, using overlay commands, or implement
7180 additional target-side support and use "overlay load-target" to bring
7181 in the overlay mapping. Do "help overlay" for more detail.
7185 The command "info symbol <address>" displays information about
7186 the symbol at the specified address.
7190 The standard remote protocol now includes an extension that allows
7191 asynchronous collection and display of trace data. This requires
7192 extensive support in the target-side debugging stub. Tracing mode
7193 includes a new interaction mode in GDB and new commands: see the
7194 file tracepoint.c for more details.
7198 Configurations for embedded MIPS now include a simulator contributed
7199 by Cygnus Solutions. The simulator supports the instruction sets
7200 of most MIPS variants.
7204 Sparc configurations may now include the ERC32 simulator contributed
7205 by the European Space Agency. The simulator is not built into
7206 Sparc targets by default; configure with --enable-sim to include it.
7210 For target configurations that may include multiple variants of a
7211 basic architecture (such as MIPS and SH), you may now set the
7212 architecture explicitly. "set arch" sets, "info arch" lists
7213 the possible architectures.
7215 *** Changes in GDB-4.16:
7217 * New native configurations
7219 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7220 M68K NetBSD m68k-*-netbsd*
7221 PowerPC AIX 4.x powerpc-*-aix*
7222 PowerPC MacOS powerpc-*-macos*
7223 PowerPC Windows NT powerpcle-*-cygwin32
7224 RS/6000 AIX 4.x rs6000-*-aix4*
7228 ARM with RDP protocol arm-*-*
7229 I960 with MON960 i960-*-coff
7230 MIPS VxWorks mips*-*-vxworks*
7231 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7232 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7234 Matra Sparclet sparclet-*-*
7238 The powerpc-eabi configuration now includes the PSIM simulator,
7239 contributed by Andrew Cagney, with assistance from Mike Meissner.
7240 PSIM is a very elaborate model of the PowerPC, including not only
7241 basic instruction set execution, but also details of execution unit
7242 performance and I/O hardware. See sim/ppc/README for more details.
7246 GDB now works with Solaris 2.5.
7248 * Windows 95/NT native
7250 GDB will now work as a native debugger on Windows 95 and Windows NT.
7251 To build it from source, you must use the "gnu-win32" environment,
7252 which uses a DLL to emulate enough of Unix to run the GNU tools.
7253 Further information, binaries, and sources are available at
7254 ftp.cygnus.com, under pub/gnu-win32.
7256 * dont-repeat command
7258 If a user-defined command includes the command `dont-repeat', then the
7259 command will not be repeated if the user just types return. This is
7260 useful if the command is time-consuming to run, so that accidental
7261 extra keystrokes don't run the same command many times.
7263 * Send break instead of ^C
7265 The standard remote protocol now includes an option to send a break
7266 rather than a ^C to the target in order to interrupt it. By default,
7267 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7269 * Remote protocol timeout
7271 The standard remote protocol includes a new variable `remotetimeout'
7272 that allows you to set the number of seconds before GDB gives up trying
7273 to read from the target. The default value is 2.
7275 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7277 By default GDB will automatically keep track of objects as they are
7278 loaded and unloaded by the dynamic linker. By using the command `set
7279 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7280 when shared library events occur, thus allowing you to set breakpoints
7281 in shared libraries which are explicitly loaded by the inferior.
7283 Note this feature does not work on hpux8. On hpux9 you must link
7284 /usr/lib/end.o into your program. This feature should work
7285 automatically on hpux10.
7287 * Irix 5.x hardware watchpoint support
7289 Irix 5 configurations now support the use of hardware watchpoints.
7291 * Mips protocol "SYN garbage limit"
7293 When debugging a Mips target using the `target mips' protocol, you
7294 may set the number of characters that GDB will ignore by setting
7295 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7296 every character. The default value is 1050.
7298 * Recording and replaying remote debug sessions
7300 If you set `remotelogfile' to the name of a file, gdb will write to it
7301 a recording of a remote debug session. This recording may then be
7302 replayed back to gdb using "gdbreplay". See gdbserver/README for
7303 details. This is useful when you have a problem with GDB while doing
7304 remote debugging; you can make a recording of the session and send it
7305 to someone else, who can then recreate the problem.
7307 * Speedups for remote debugging
7309 GDB includes speedups for downloading and stepping MIPS systems using
7310 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7311 and more efficient S-record downloading.
7313 * Memory use reductions and statistics collection
7315 GDB now uses less memory and reports statistics about memory usage.
7316 Try the `maint print statistics' command, for example.
7318 *** Changes in GDB-4.15:
7320 * Psymtabs for XCOFF
7322 The symbol reader for AIX GDB now uses partial symbol tables. This
7323 can greatly improve startup time, especially for large executables.
7325 * Remote targets use caching
7327 Remote targets now use a data cache to speed up communication with the
7328 remote side. The data cache could lead to incorrect results because
7329 it doesn't know about volatile variables, thus making it impossible to
7330 debug targets which use memory mapped I/O devices. `set remotecache
7331 off' turns the data cache off.
7333 * Remote targets may have threads
7335 The standard remote protocol now includes support for multiple threads
7336 in the target system, using new protocol commands 'H' and 'T'. See
7337 gdb/remote.c for details.
7341 If GDB is configured with `--enable-netrom', then it will include
7342 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7343 acts as though it is a bank of ROM on the target board, but you can
7344 write into it over the network. GDB's support consists only of
7345 support for fast loading into the emulated ROM; to debug, you must use
7346 another protocol, such as standard remote protocol. The usual
7347 sequence is something like
7349 target nrom <netrom-hostname>
7351 target remote <netrom-hostname>:1235
7355 GDB now includes support for the Apple Macintosh, as a host only. It
7356 may be run as either an MPW tool or as a standalone application, and
7357 it can debug through the serial port. All the usual GDB commands are
7358 available, but to the target command, you must supply "serial" as the
7359 device type instead of "/dev/ttyXX". See mpw-README in the main
7360 directory for more information on how to build. The MPW configuration
7361 scripts */mpw-config.in support only a few targets, and only the
7362 mips-idt-ecoff target has been tested.
7366 GDB configuration now uses autoconf. This is not user-visible,
7367 but does simplify configuration and building.
7371 GDB now supports hpux10.
7373 *** Changes in GDB-4.14:
7375 * New native configurations
7377 x86 FreeBSD i[345]86-*-freebsd
7378 x86 NetBSD i[345]86-*-netbsd
7379 NS32k NetBSD ns32k-*-netbsd
7380 Sparc NetBSD sparc-*-netbsd
7384 A29K VxWorks a29k-*-vxworks
7385 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7386 CPU32 EST-300 emulator m68*-*-est*
7387 PowerPC ELF powerpc-*-elf
7390 * Alpha OSF/1 support for procfs
7392 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7393 possible to attach to running processes. As the mounting of the /proc
7394 filesystem is optional on the Alpha, GDB automatically determines
7395 the availability of /proc during startup. This can lead to problems
7396 if /proc is unmounted after GDB has been started.
7398 * Arguments to user-defined commands
7400 User commands may accept up to 10 arguments separated by whitespace.
7401 Arguments are accessed within the user command via $arg0..$arg9. A
7404 print $arg0 + $arg1 + $arg2
7406 To execute the command use:
7409 Defines the command "adder" which prints the sum of its three arguments.
7410 Note the arguments are text substitutions, so they may reference variables,
7411 use complex expressions, or even perform inferior function calls.
7413 * New `if' and `while' commands
7415 This makes it possible to write more sophisticated user-defined
7416 commands. Both commands take a single argument, which is the
7417 expression to evaluate, and must be followed by the commands to
7418 execute, one per line, if the expression is nonzero, the list being
7419 terminated by the word `end'. The `if' command list may include an
7420 `else' word, which causes the following commands to be executed only
7421 if the expression is zero.
7423 * Fortran source language mode
7425 GDB now includes partial support for Fortran 77. It will recognize
7426 Fortran programs and can evaluate a subset of Fortran expressions, but
7427 variables and functions may not be handled correctly. GDB will work
7428 with G77, but does not yet know much about symbols emitted by other
7431 * Better HPUX support
7433 Most debugging facilities now work on dynamic executables for HPPAs
7434 running hpux9 or later. You can attach to running dynamically linked
7435 processes, but by default the dynamic libraries will be read-only, so
7436 for instance you won't be able to put breakpoints in them. To change
7437 that behavior do the following before running the program:
7443 This will cause the libraries to be mapped private and read-write.
7444 To revert to the normal behavior, do this:
7450 You cannot set breakpoints or examine data in the library until after
7451 the library is loaded if the function/data symbols do not have
7454 GDB can now also read debug symbols produced by the HP C compiler on
7455 HPPAs (sorry, no C++, Fortran or 68k support).
7457 * Target byte order now dynamically selectable
7459 You can choose which byte order to use with a target system, via the
7460 commands "set endian big" and "set endian little", and you can see the
7461 current setting by using "show endian". You can also give the command
7462 "set endian auto", in which case GDB will use the byte order
7463 associated with the executable. Currently, only embedded MIPS
7464 configurations support dynamic selection of target byte order.
7466 * New DOS host serial code
7468 This version uses DPMI interrupts to handle buffered I/O, so you
7469 no longer need to run asynctsr when debugging boards connected to
7472 *** Changes in GDB-4.13:
7474 * New "complete" command
7476 This lists all the possible completions for the rest of the line, if it
7477 were to be given as a command itself. This is intended for use by emacs.
7479 * Trailing space optional in prompt
7481 "set prompt" no longer adds a space for you after the prompt you set. This
7482 allows you to set a prompt which ends in a space or one that does not.
7484 * Breakpoint hit counts
7486 "info break" now displays a count of the number of times the breakpoint
7487 has been hit. This is especially useful in conjunction with "ignore"; you
7488 can ignore a large number of breakpoint hits, look at the breakpoint info
7489 to see how many times the breakpoint was hit, then run again, ignoring one
7490 less than that number, and this will get you quickly to the last hit of
7493 * Ability to stop printing at NULL character
7495 "set print null-stop" will cause GDB to stop printing the characters of
7496 an array when the first NULL is encountered. This is useful when large
7497 arrays actually contain only short strings.
7499 * Shared library breakpoints
7501 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7502 breakpoints in shared libraries before the executable is run.
7504 * Hardware watchpoints
7506 There is a new hardware breakpoint for the watch command for sparclite
7507 targets. See gdb/sparclite/hw_breakpoint.note.
7509 Hardware watchpoints are also now supported under GNU/Linux.
7513 Annotations have been added. These are for use with graphical interfaces,
7514 and are still experimental. Currently only gdba.el uses these.
7516 * Improved Irix 5 support
7518 GDB now works properly with Irix 5.2.
7520 * Improved HPPA support
7522 GDB now works properly with the latest GCC and GAS.
7524 * New native configurations
7526 Sequent PTX4 i[34]86-sequent-ptx4
7527 HPPA running OSF/1 hppa*-*-osf*
7528 Atari TT running SVR4 m68*-*-sysv4*
7529 RS/6000 LynxOS rs6000-*-lynxos*
7533 OS/9000 i[34]86-*-os9k
7534 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7537 * Hitachi SH7000 and E7000-PC ICE support
7539 There is now support for communicating with the Hitachi E7000-PC ICE.
7540 This is available automatically when GDB is configured for the SH.
7544 As usual, a variety of small fixes and improvements, both generic
7545 and configuration-specific. See the ChangeLog for more detail.
7547 *** Changes in GDB-4.12:
7549 * Irix 5 is now supported
7553 GDB-4.12 on the HPPA has a number of changes which make it unable
7554 to debug the output from the currently released versions of GCC and
7555 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7556 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7557 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7560 *** Changes in GDB-4.11:
7562 * User visible changes:
7566 The "set remotedebug" option is now consistent between the mips remote
7567 target, remote targets using the gdb-specific protocol, UDI (AMD's
7568 debug protocol for the 29k) and the 88k bug monitor. It is now an
7569 integer specifying a debug level (normally 0 or 1, but 2 means more
7570 debugging info for the mips target).
7572 * DEC Alpha native support
7574 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7575 debug info, but GDB works fairly well with the DEC compiler and should
7576 work with a future GCC release. See the README file for a few
7577 Alpha-specific notes.
7579 * Preliminary thread implementation
7581 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7583 * LynxOS native and target support for 386
7585 This release has been hosted on LynxOS 2.2, and also can be configured
7586 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7589 * Improvements in C++ mangling/demangling.
7591 This release has much better g++ debugging, specifically in name
7592 mangling/demangling, virtual function calls, print virtual table,
7593 call methods, ...etc.
7595 *** Changes in GDB-4.10:
7597 * User visible changes:
7599 Remote debugging using the GDB-specific (`target remote') protocol now
7600 supports the `load' command. This is only useful if you have some
7601 other way of getting the stub to the target system, and you can put it
7602 somewhere in memory where it won't get clobbered by the download.
7604 Filename completion now works.
7606 When run under emacs mode, the "info line" command now causes the
7607 arrow to point to the line specified. Also, "info line" prints
7608 addresses in symbolic form (as well as hex).
7610 All vxworks based targets now support a user settable option, called
7611 vxworks-timeout. This option represents the number of seconds gdb
7612 should wait for responses to rpc's. You might want to use this if
7613 your vxworks target is, perhaps, a slow software simulator or happens
7614 to be on the far side of a thin network line.
7618 This release contains support for using a DEC alpha as a GDB host for
7619 cross debugging. Native alpha debugging is not supported yet.
7622 *** Changes in GDB-4.9:
7626 This is the first GDB release which is accompanied by a matching testsuite.
7627 The testsuite requires installation of dejagnu, which should be available
7628 via ftp from most sites that carry GNU software.
7632 'Cfront' style demangling has had its name changed to 'ARM' style, to
7633 emphasize that it was written from the specifications in the C++ Annotated
7634 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7635 disclaimers, it still generated too much confusion with users attempting to
7636 use gdb with AT&T cfront.
7640 GDB now uses a standard remote interface to a simulator library.
7641 So far, the library contains simulators for the Zilog Z8001/2, the
7642 Hitachi H8/300, H8/500 and Super-H.
7644 * New targets supported
7646 H8/300 simulator h8300-hitachi-hms or h8300hms
7647 H8/500 simulator h8500-hitachi-hms or h8500hms
7648 SH simulator sh-hitachi-hms or sh
7649 Z8000 simulator z8k-zilog-none or z8ksim
7650 IDT MIPS board over serial line mips-idt-ecoff
7652 Cross-debugging to GO32 targets is supported. It requires a custom
7653 version of the i386-stub.c module which is integrated with the
7654 GO32 memory extender.
7656 * New remote protocols
7658 MIPS remote debugging protocol.
7660 * New source languages supported
7662 This version includes preliminary support for Chill, a Pascal like language
7663 used by telecommunications companies. Chill support is also being integrated
7664 into the GNU compiler, but we don't know when it will be publically available.
7667 *** Changes in GDB-4.8:
7669 * HP Precision Architecture supported
7671 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7672 version of this support was available as a set of patches from the
7673 University of Utah. GDB does not support debugging of programs
7674 compiled with the HP compiler, because HP will not document their file
7675 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7676 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7678 Many problems in the preliminary version have been fixed.
7680 * Faster and better demangling
7682 We have improved template demangling and fixed numerous bugs in the GNU style
7683 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7684 character types (wchar_t) are now supported. Demangling of each symbol is now
7685 only done once, and is cached when the symbol table for a file is read in.
7686 This results in a small increase in memory usage for C programs, a moderate
7687 increase in memory usage for C++ programs, and a fantastic speedup in
7690 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7691 from the specifications in the Annotated Reference Manual, which AT&T's
7692 compiler does not actually implement.
7694 * G++ multiple inheritance compiler problem
7696 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7697 inheritance lattices was reworked to properly discover ambiguities. We
7698 recently found an example which causes this new algorithm to fail in a
7699 very subtle way, producing bad debug information for those classes.
7700 The file 'gcc.patch' (in this directory) can be applied to gcc to
7701 circumvent the problem. A future GCC release will contain a complete
7704 The previous G++ debug info problem (mentioned below for the gdb-4.7
7705 release) is fixed in gcc version 2.3.2.
7707 * Improved configure script
7709 The `configure' script will now attempt to guess your system type if
7710 you don't supply a host system type. The old scheme of supplying a
7711 host system triplet is preferable over using this. All the magic is
7712 done in the new `config.guess' script. Examine it for details.
7714 We have also brought our configure script much more in line with the FSF's
7715 version. It now supports the --with-xxx options. In particular,
7716 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7717 The resulting GDB will not be able to read arbitrary object file formats --
7718 only the format ``expected'' to be used on the configured target system.
7719 We hope to make this the default in a future release.
7721 * Documentation improvements
7723 There's new internal documentation on how to modify GDB, and how to
7724 produce clean changes to the code. We implore people to read it
7725 before submitting changes.
7727 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7728 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7729 `info' files are also provided. To build `info' files from scratch,
7730 you will need the latest `makeinfo' release, which will be available in
7731 a future texinfo-X.Y release.
7733 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7734 We're not sure exactly which versions have this problem, but it has
7735 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7736 or better. If that isn't possible, there is a patch in
7737 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7738 around this problem.
7742 GDB now supports array constants that can be used in expressions typed in by
7743 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7744 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7747 The new directory `gdb/sparclite' contains a program that demonstrates
7748 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7750 * New native hosts supported
7752 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7753 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7755 * New targets supported
7757 AMD 29k family via UDI a29k-amd-udi or udi29k
7759 * New file formats supported
7761 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7762 HPUX core files, and SCO 3.2v2 core files.
7766 Attaching to processes now works again; thanks for the many bug reports.
7768 We have also stomped on a bunch of core dumps caused by
7769 printf_filtered("%s") problems.
7771 We eliminated a copyright problem on the rpc and ptrace header files
7772 for VxWorks, which was discovered at the last minute during the 4.7
7773 release. You should now be able to build a VxWorks GDB.
7775 You can now interrupt gdb while an attached process is running. This
7776 will cause the attached process to stop, and give control back to GDB.
7778 We fixed problems caused by using too many file descriptors
7779 for reading symbols from object files and libraries. This was
7780 especially a problem for programs that used many (~100) shared
7783 The `step' command now only enters a subroutine if there is line number
7784 information for the subroutine. Otherwise it acts like the `next'
7785 command. Previously, `step' would enter subroutines if there was
7786 any debugging information about the routine. This avoids problems
7787 when using `cc -g1' on MIPS machines.
7789 * Internal improvements
7791 GDB's internal interfaces have been improved to make it easier to support
7792 debugging of multiple languages in the future.
7794 GDB now uses a common structure for symbol information internally.
7795 Minimal symbols (derived from linkage symbols in object files), partial
7796 symbols (from a quick scan of debug information), and full symbols
7797 contain a common subset of information, making it easier to write
7798 shared code that handles any of them.
7800 * New command line options
7802 We now accept --silent as an alias for --quiet.
7806 The memory-mapped-malloc library is now licensed under the GNU Library
7807 General Public License.
7809 *** Changes in GDB-4.7:
7811 * Host/native/target split
7813 GDB has had some major internal surgery to untangle the support for
7814 hosts and remote targets. Now, when you configure GDB for a remote
7815 target, it will no longer load in all of the support for debugging
7816 local programs on the host. When fully completed and tested, this will
7817 ensure that arbitrary host/target combinations are possible.
7819 The primary conceptual shift is to separate the non-portable code in
7820 GDB into three categories. Host specific code is required any time GDB
7821 is compiled on that host, regardless of the target. Target specific
7822 code relates to the peculiarities of the target, but can be compiled on
7823 any host. Native specific code is everything else: it can only be
7824 built when the host and target are the same system. Child process
7825 handling and core file support are two common `native' examples.
7827 GDB's use of /proc for controlling Unix child processes is now cleaner.
7828 It has been split out into a single module under the `target_ops' vector,
7829 plus two native-dependent functions for each system that uses /proc.
7831 * New hosts supported
7833 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7834 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7835 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7837 * New targets supported
7839 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7840 68030 and CPU32 m68030-*-*, m68332-*-*
7842 * New native hosts supported
7844 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7845 (386bsd is not well tested yet)
7846 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7848 * New file formats supported
7850 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7851 supports reading of `a.out.adobe' object files, which are an a.out
7852 format extended with minimal information about multiple sections.
7856 `show copying' is the same as the old `info copying'.
7857 `show warranty' is the same as `info warrantee'.
7858 These were renamed for consistency. The old commands continue to work.
7860 `info handle' is a new alias for `info signals'.
7862 You can now define pre-command hooks, which attach arbitrary command
7863 scripts to any command. The commands in the hook will be executed
7864 prior to the user's command. You can also create a hook which will be
7865 executed whenever the program stops. See gdb.texinfo.
7869 We now deal with Cfront style name mangling, and can even extract type
7870 info from mangled symbols. GDB can automatically figure out which
7871 symbol mangling style your C++ compiler uses.
7873 Calling of methods and virtual functions has been improved as well.
7877 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7878 fixed. This was due to mishandling of the extra N_SO stabs output
7881 We also finally got Ultrix 4.2 running in house, and fixed core file
7882 support, with help from a dozen people on the net.
7884 John M. Farrell discovered that the reason that single-stepping was so
7885 slow on all of the Mips based platforms (primarily SGI and DEC) was
7886 that we were trying to demangle and lookup a symbol used for internal
7887 purposes on every instruction that was being stepped through. Changing
7888 the name of that symbol so that it couldn't be mistaken for a C++
7889 mangled symbol sped things up a great deal.
7891 Rich Pixley sped up symbol lookups in general by getting much smarter
7892 about when C++ symbol mangling is necessary. This should make symbol
7893 completion (TAB on the command line) much faster. It's not as fast as
7894 we'd like, but it's significantly faster than gdb-4.6.
7898 A new user controllable variable 'call_scratch_address' can
7899 specify the location of a scratch area to be used when GDB
7900 calls a function in the target. This is necessary because the
7901 usual method of putting the scratch area on the stack does not work
7902 in systems that have separate instruction and data spaces.
7904 We integrated changes to support the 29k UDI (Universal Debugger
7905 Interface), but discovered at the last minute that we didn't have all
7906 of the appropriate copyright paperwork. We are working with AMD to
7907 resolve this, and hope to have it available soon.
7911 We have sped up the remote serial line protocol, especially for targets
7912 with lots of registers. It now supports a new `expedited status' ('T')
7913 message which can be used in place of the existing 'S' status message.
7914 This allows the remote stub to send only the registers that GDB
7915 needs to make a quick decision about single-stepping or conditional
7916 breakpoints, eliminating the need to fetch the entire register set for
7917 each instruction being stepped through.
7919 The GDB remote serial protocol now implements a write-through cache for
7920 registers, only re-reading the registers if the target has run.
7922 There is also a new remote serial stub for SPARC processors. You can
7923 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7924 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7925 processor with a serial port.
7929 Configure.in files have become much easier to read and modify. A new
7930 `table driven' format makes it more obvious what configurations are
7931 supported, and what files each one uses.
7935 There is a new opcodes library which will eventually contain all of the
7936 disassembly routines and opcode tables. At present, it only contains
7937 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7938 disassembler (binutils/objdump) to share these routines.
7940 The libiberty library is now copylefted under the GNU Library General
7941 Public License. This allows more liberal use, and was done so libg++
7942 can use it. This makes no difference to GDB, since the Library License
7943 grants all the rights from the General Public License.
7947 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7948 reference to the stabs symbol info used by the debugger. It is (as far
7949 as we know) the only published document on this fascinating topic. We
7950 encourage you to read it, compare it to the stabs information on your
7951 system, and send improvements on the document in general (to
7952 bug-gdb@prep.ai.mit.edu).
7954 And, of course, many bugs have been fixed.
7957 *** Changes in GDB-4.6:
7959 * Better support for C++ function names
7961 GDB now accepts as input the "demangled form" of C++ overloaded function
7962 names and member function names, and can do command completion on such names
7963 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7964 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7965 Make use of command completion, it is your friend.
7967 GDB also now accepts a variety of C++ mangled symbol formats. They are
7968 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7969 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7970 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7971 for the list of formats.
7973 * G++ symbol mangling problem
7975 Recent versions of gcc have a bug in how they emit debugging information for
7976 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7977 directory) can be applied to gcc to fix the problem. Alternatively, if you
7978 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7979 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7980 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7983 * New 'maintenance' command
7985 All of the commands related to hacking GDB internals have been moved out of
7986 the main command set, and now live behind the 'maintenance' command. This
7987 can also be abbreviated as 'mt'. The following changes were made:
7989 dump-me -> maintenance dump-me
7990 info all-breakpoints -> maintenance info breakpoints
7991 printmsyms -> maintenance print msyms
7992 printobjfiles -> maintenance print objfiles
7993 printpsyms -> maintenance print psymbols
7994 printsyms -> maintenance print symbols
7996 The following commands are new:
7998 maintenance demangle Call internal GDB demangler routine to
7999 demangle a C++ link name and prints the result.
8000 maintenance print type Print a type chain for a given symbol
8002 * Change to .gdbinit file processing
8004 We now read the $HOME/.gdbinit file before processing the argv arguments
8005 (e.g. reading symbol files or core files). This allows global parameters to
8006 be set, which will apply during the symbol reading. The ./.gdbinit is still
8007 read after argv processing.
8009 * New hosts supported
8011 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8013 GNU/Linux support i386-unknown-linux or linux
8015 We are also including code to support the HP/PA running BSD and HPUX. This
8016 is almost guaranteed not to work, as we didn't have time to test or build it
8017 for this release. We are including it so that the more adventurous (or
8018 masochistic) of you can play with it. We also had major problems with the
8019 fact that the compiler that we got from HP doesn't support the -g option.
8022 * New targets supported
8024 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8026 * More smarts about finding #include files
8028 GDB now remembers the compilation directory for all include files, and for
8029 all files from which C is generated (like yacc and lex sources). This
8030 greatly improves GDB's ability to find yacc/lex sources, and include files,
8031 especially if you are debugging your program from a directory different from
8032 the one that contains your sources.
8034 We also fixed a bug which caused difficulty with listing and setting
8035 breakpoints in include files which contain C code. (In the past, you had to
8036 try twice in order to list an include file that you hadn't looked at before.)
8038 * Interesting infernals change
8040 GDB now deals with arbitrary numbers of sections, where the symbols for each
8041 section must be relocated relative to that section's landing place in the
8042 target's address space. This work was needed to support ELF with embedded
8043 stabs used by Solaris-2.0.
8045 * Bug fixes (of course!)
8047 There have been loads of fixes for the following things:
8048 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8049 i960, stabs, DOS(GO32), procfs, etc...
8051 See the ChangeLog for details.
8053 *** Changes in GDB-4.5:
8055 * New machines supported (host and target)
8057 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8059 SGI Irix-4.x mips-sgi-irix4 or iris4
8061 * New malloc package
8063 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8064 Mmalloc is capable of handling multiple heaps of memory. It is also
8065 capable of saving a heap to a file, and then mapping it back in later.
8066 This can be used to greatly speedup the startup of GDB by using a
8067 pre-parsed symbol table which lives in a mmalloc managed heap. For
8068 more details, please read mmalloc/mmalloc.texi.
8072 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8073 'help info proc' for details.
8075 * MIPS ecoff symbol table format
8077 The code that reads MIPS symbol table format is now supported on all hosts.
8078 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8081 * File name changes for MS-DOS
8083 Many files in the config directories have been renamed to make it easier to
8084 support GDB on MS-DOSe systems (which have very restrictive file name
8085 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8086 environment) is close to working but has some remaining problems. Note
8087 that debugging of DOS programs is not supported, due to limitations
8088 in the ``operating system'', but it can be used to host cross-debugging.
8090 * Cross byte order fixes
8092 Many fixes have been made to support cross debugging of Sparc and MIPS
8093 targets from hosts whose byte order differs.
8095 * New -mapped and -readnow options
8097 If memory-mapped files are available on your system through the 'mmap'
8098 system call, you can use the -mapped option on the `file' or
8099 `symbol-file' commands to cause GDB to write the symbols from your
8100 program into a reusable file. If the program you are debugging is
8101 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8102 Future GDB debugging sessions will notice the presence of this file,
8103 and will quickly map in symbol information from it, rather than reading
8104 the symbol table from the executable program. Using the '-mapped'
8105 option in a GDB `file' or `symbol-file' command has the same effect as
8106 starting GDB with the '-mapped' command-line option.
8108 You can cause GDB to read the entire symbol table immediately by using
8109 the '-readnow' option with any of the commands that load symbol table
8110 information (or on the GDB command line). This makes the command
8111 slower, but makes future operations faster.
8113 The -mapped and -readnow options are typically combined in order to
8114 build a `fred.syms' file that contains complete symbol information.
8115 A simple GDB invocation to do nothing but build a `.syms' file for future
8118 gdb -batch -nx -mapped -readnow programname
8120 The `.syms' file is specific to the host machine on which GDB is run.
8121 It holds an exact image of GDB's internal symbol table. It cannot be
8122 shared across multiple host platforms.
8124 * longjmp() handling
8126 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8127 siglongjmp() without losing control. This feature has not yet been ported to
8128 all systems. It currently works on many 386 platforms, all MIPS-based
8129 platforms (SGI, DECstation, etc), and Sun3/4.
8133 Preliminary work has been put in to support the new Solaris OS from Sun. At
8134 this time, it can control and debug processes, but it is not capable of
8139 As always, many many bug fixes. The major areas were with g++, and mipsread.
8140 People using the MIPS-based platforms should experience fewer mysterious
8141 crashes and trashed symbol tables.
8143 *** Changes in GDB-4.4:
8145 * New machines supported (host and target)
8147 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8149 BSD Reno on Vax vax-dec-bsd
8150 Ultrix on Vax vax-dec-ultrix
8152 * New machines supported (target)
8154 AMD 29000 embedded, using EBMON a29k-none-none
8158 GDB continues to improve its handling of C++. `References' work better.
8159 The demangler has also been improved, and now deals with symbols mangled as
8160 per the Annotated C++ Reference Guide.
8162 GDB also now handles `stabs' symbol information embedded in MIPS
8163 `ecoff' symbol tables. Since the ecoff format was not easily
8164 extensible to handle new languages such as C++, this appeared to be a
8165 good way to put C++ debugging info into MIPS binaries. This option
8166 will be supported in the GNU C compiler, version 2, when it is
8169 * New features for SVR4
8171 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8172 shared libraries. Debugging dynamically linked programs should present
8173 only minor differences from debugging statically linked programs.
8175 The `info proc' command will print out information about any process
8176 on an SVR4 system (including the one you are debugging). At the moment,
8177 it prints the address mappings of the process.
8179 If you bring up GDB on another SVR4 system, please send mail to
8180 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8182 * Better dynamic linking support in SunOS
8184 Reading symbols from shared libraries which contain debugging symbols
8185 now works properly. However, there remain issues such as automatic
8186 skipping of `transfer vector' code during function calls, which
8187 make it harder to debug code in a shared library, than to debug the
8188 same code linked statically.
8192 GDB is now using the latest `getopt' routines from the FSF. This
8193 version accepts the -- prefix for options with long names. GDB will
8194 continue to accept the old forms (-option and +option) as well.
8195 Various single letter abbreviations for options have been explicity
8196 added to the option table so that they won't get overshadowed in the
8197 future by other options that begin with the same letter.
8201 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8202 Many assorted bugs have been handled. Many more remain to be handled.
8203 See the various ChangeLog files (primarily in gdb and bfd) for details.
8206 *** Changes in GDB-4.3:
8208 * New machines supported (host and target)
8210 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8211 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8212 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8214 * Almost SCO Unix support
8216 We had hoped to support:
8217 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8218 (except for core file support), but we discovered very late in the release
8219 that it has problems with process groups that render gdb unusable. Sorry
8220 about that. I encourage people to fix it and post the fixes.
8222 * Preliminary ELF and DWARF support
8224 GDB can read ELF object files on System V Release 4, and can handle
8225 debugging records for C, in DWARF format, in ELF files. This support
8226 is preliminary. If you bring up GDB on another SVR4 system, please
8227 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8232 GDB now uses the latest `readline' library. One user-visible change
8233 is that two tabs will list possible command completions, which previously
8234 required typing M-? (meta-question mark, or ESC ?).
8238 The `stepi' bug that many of you noticed has been squashed.
8239 Many bugs in C++ have been handled. Many more remain to be handled.
8240 See the various ChangeLog files (primarily in gdb and bfd) for details.
8242 * State of the MIPS world (in case you wondered):
8244 GDB can understand the symbol tables emitted by the compilers
8245 supplied by most vendors of MIPS-based machines, including DEC. These
8246 symbol tables are in a format that essentially nobody else uses.
8248 Some versions of gcc come with an assembler post-processor called
8249 mips-tfile. This program is required if you want to do source-level
8250 debugging of gcc-compiled programs. I believe FSF does not ship
8251 mips-tfile with gcc version 1, but it will eventually come with gcc
8254 Debugging of g++ output remains a problem. g++ version 1.xx does not
8255 really support it at all. (If you're lucky, you should be able to get
8256 line numbers and stack traces to work, but no parameters or local
8257 variables.) With some work it should be possible to improve the
8260 When gcc version 2 is released, you will have somewhat better luck.
8261 However, even then you will get confusing results for inheritance and
8264 We will eventually provide full debugging of g++ output on
8265 DECstations. This will probably involve some kind of stabs-in-ecoff
8266 encapulation, but the details have not been worked out yet.
8269 *** Changes in GDB-4.2:
8271 * Improved configuration
8273 Only one copy of `configure' exists now, and it is not self-modifying.
8274 Porting BFD is simpler.
8278 The `step' and `next' commands now only stop at the first instruction
8279 of a source line. This prevents the multiple stops that used to occur
8280 in switch statements, for-loops, etc. `Step' continues to stop if a
8281 function that has debugging information is called within the line.
8285 Lots of small bugs fixed. More remain.
8287 * New host supported (not target)
8289 Intel 386 PC clone running Mach i386-none-mach
8292 *** Changes in GDB-4.1:
8294 * Multiple source language support
8296 GDB now has internal scaffolding to handle several source languages.
8297 It determines the type of each source file from its filename extension,
8298 and will switch expression parsing and number formatting to match the
8299 language of the function in the currently selected stack frame.
8300 You can also specifically set the language to be used, with
8301 `set language c' or `set language modula-2'.
8305 GDB now has preliminary support for the GNU Modula-2 compiler,
8306 currently under development at the State University of New York at
8307 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8308 continue through the fall of 1991 and into 1992.
8310 Other Modula-2 compilers are currently not supported, and attempting to
8311 debug programs compiled with them will likely result in an error as the
8312 symbol table is read. Feel free to work on it, though!
8314 There are hooks in GDB for strict type checking and range checking,
8315 in the `Modula-2 philosophy', but they do not currently work.
8319 GDB can now write to executable and core files (e.g. patch
8320 a variable's value). You must turn this switch on, specify
8321 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8322 by assigning a new value to a variable. Modifications take
8325 * Automatic SunOS shared library reading
8327 When you run your program, GDB automatically determines where its
8328 shared libraries (if any) have been loaded, and reads their symbols.
8329 The `share' command is no longer needed. This also works when
8330 examining core files.
8334 You can specify the number of lines that the `list' command shows.
8337 * New machines supported (host and target)
8339 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8340 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8341 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8343 * New hosts supported (not targets)
8345 IBM RT/PC: romp-ibm-aix or rtpc
8347 * New targets supported (not hosts)
8349 AMD 29000 embedded with COFF a29k-none-coff
8350 AMD 29000 embedded with a.out a29k-none-aout
8351 Ultracomputer remote kernel debug a29k-nyu-kern
8353 * New remote interfaces
8359 *** Changes in GDB-4.0:
8363 Wide output is wrapped at good places to make the output more readable.
8365 Gdb now supports cross-debugging from a host machine of one type to a
8366 target machine of another type. Communication with the target system
8367 is over serial lines. The ``target'' command handles connecting to the
8368 remote system; the ``load'' command will download a program into the
8369 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8370 also supports debugging of realtime processes running under VxWorks,
8371 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8372 stub on the target system.
8374 New CPUs supported include the AMD 29000 and Intel 960.
8376 GDB now reads object files and symbol tables via a ``binary file''
8377 library, which allows a single copy of GDB to debug programs of multiple
8378 object file types such as a.out and coff.
8380 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8381 refcard.dvi and refcard.ps are available to format it).
8384 * Control-Variable user interface simplified
8386 All variables that control the operation of the debugger can be set
8387 by the ``set'' command, and displayed by the ``show'' command.
8389 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8390 ``Show prompt'' produces the response:
8391 Gdb's prompt is new-gdb=>.
8393 What follows are the NEW set commands. The command ``help set'' will
8394 print a complete list of old and new set commands. ``help set FOO''
8395 will give a longer description of the variable FOO. ``show'' will show
8396 all of the variable descriptions and their current settings.
8398 confirm on/off: Enables warning questions for operations that are
8399 hard to recover from, e.g. rerunning the program while
8400 it is already running. Default is ON.
8402 editing on/off: Enables EMACS style command line editing
8403 of input. Previous lines can be recalled with
8404 control-P, the current line can be edited with control-B,
8405 you can search for commands with control-R, etc.
8408 history filename NAME: NAME is where the gdb command history
8409 will be stored. The default is .gdb_history,
8410 or the value of the environment variable
8413 history size N: The size, in commands, of the command history. The
8414 default is 256, or the value of the environment variable
8417 history save on/off: If this value is set to ON, the history file will
8418 be saved after exiting gdb. If set to OFF, the
8419 file will not be saved. The default is OFF.
8421 history expansion on/off: If this value is set to ON, then csh-like
8422 history expansion will be performed on
8423 command line input. The default is OFF.
8425 radix N: Sets the default radix for input and output. It can be set
8426 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8427 in the current radix, so "set radix 10" is always a no-op.
8429 height N: This integer value is the number of lines on a page. Default
8430 is 24, the current `stty rows'' setting, or the ``li#''
8431 setting from the termcap entry matching the environment
8434 width N: This integer value is the number of characters on a line.
8435 Default is 80, the current `stty cols'' setting, or the ``co#''
8436 setting from the termcap entry matching the environment
8439 Note: ``set screensize'' is obsolete. Use ``set height'' and
8440 ``set width'' instead.
8442 print address on/off: Print memory addresses in various command displays,
8443 such as stack traces and structure values. Gdb looks
8444 more ``symbolic'' if you turn this off; it looks more
8445 ``machine level'' with it on. Default is ON.
8447 print array on/off: Prettyprint arrays. New convenient format! Default
8450 print demangle on/off: Print C++ symbols in "source" form if on,
8453 print asm-demangle on/off: Same, for assembler level printouts
8456 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8459 * Support for Epoch Environment.
8461 The epoch environment is a version of Emacs v18 with windowing. One
8462 new command, ``inspect'', is identical to ``print'', except that if you
8463 are running in the epoch environment, the value is printed in its own
8467 * Support for Shared Libraries
8469 GDB can now debug programs and core files that use SunOS shared libraries.
8470 Symbols from a shared library cannot be referenced
8471 before the shared library has been linked with the program (this
8472 happens after you type ``run'' and before the function main() is entered).
8473 At any time after this linking (including when examining core files
8474 from dynamically linked programs), gdb reads the symbols from each
8475 shared library when you type the ``sharedlibrary'' command.
8476 It can be abbreviated ``share''.
8478 sharedlibrary REGEXP: Load shared object library symbols for files
8479 matching a unix regular expression. No argument
8480 indicates to load symbols for all shared libraries.
8482 info sharedlibrary: Status of loaded shared libraries.
8487 A watchpoint stops execution of a program whenever the value of an
8488 expression changes. Checking for this slows down execution
8489 tremendously whenever you are in the scope of the expression, but is
8490 quite useful for catching tough ``bit-spreader'' or pointer misuse
8491 problems. Some machines such as the 386 have hardware for doing this
8492 more quickly, and future versions of gdb will use this hardware.
8494 watch EXP: Set a watchpoint (breakpoint) for an expression.
8496 info watchpoints: Information about your watchpoints.
8498 delete N: Deletes watchpoint number N (same as breakpoints).
8499 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8500 enable N: Re-enables watchpoint number N (same as breakpoints).
8503 * C++ multiple inheritance
8505 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8508 * C++ exception handling
8510 Gdb now supports limited C++ exception handling. Besides the existing
8511 ability to breakpoint on an exception handler, gdb can breakpoint on
8512 the raising of an exception (before the stack is peeled back to the
8515 catch FOO: If there is a FOO exception handler in the dynamic scope,
8516 set a breakpoint to catch exceptions which may be raised there.
8517 Multiple exceptions (``catch foo bar baz'') may be caught.
8519 info catch: Lists all exceptions which may be caught in the
8520 current stack frame.
8523 * Minor command changes
8525 The command ``call func (arg, arg, ...)'' now acts like the print
8526 command, except it does not print or save a value if the function's result
8527 is void. This is similar to dbx usage.
8529 The ``up'' and ``down'' commands now always print the frame they end up
8530 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8531 frames without printing.
8533 * New directory command
8535 'dir' now adds directories to the FRONT of the source search path.
8536 The path starts off empty. Source files that contain debug information
8537 about the directory in which they were compiled can be found even
8538 with an empty path; Sun CC and GCC include this information. If GDB can't
8539 find your source file in the current directory, type "dir .".
8541 * Configuring GDB for compilation
8543 For normal use, type ``./configure host''. See README or gdb.texinfo
8546 GDB now handles cross debugging. If you are remotely debugging between
8547 two different machines, type ``./configure host -target=targ''.
8548 Host is the machine where GDB will run; targ is the machine
8549 where the program that you are debugging will run.