1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 11
6 * DBX mode is deprecated, and will be removed in GDB 13
8 * GDB 12 is the last release of GDB that will support building against
9 Python 2. From GDB 13, it will only be possible to build GDB itself
10 with Python 3 support.
12 * Improved C++ template support
14 GDB now treats functions/types involving C++ templates like it does function
15 overloads. Users may omit parameter lists to set breakpoints on families of
16 template functions, including types/functions composed of multiple template types:
18 (gdb) break template_func(template_1, int)
20 The above will set breakpoints at every function `template_func' where
21 the first function parameter is any template type named `template_1' and
22 the second function parameter is `int'.
24 TAB completion also gains similar improvements.
26 * The FreeBSD native target now supports async mode.
32 Enable or disable multithreaded symbol loading. This is enabled
33 by default, but passing --disable-threading or --enable-threading=no
34 to configure will disable it.
36 Disabling this can cause a performance penalty when there are a lot of
37 symbols to load, but is useful for debugging purposes.
41 maint set backtrace-on-fatal-signal on|off
42 maint show backtrace-on-fatal-signal
43 This setting is 'on' by default. When 'on' GDB will print a limited
44 backtrace to stderr in the situation where GDB terminates with a
45 fatal signal. This only supported on some platforms where the
46 backtrace and backtrace_symbols_fd functions are available.
48 set source open on|off
50 This setting, which is on by default, controls whether GDB will try
51 to open source code files. Switching this off will stop GDB trying
52 to open and read source code files, which can be useful if the files
53 are located over a slow network connection.
57 These are now deprecated aliases for "set max-value-size" and
58 "show max-value-size".
60 task apply [all | TASK-IDS...] [FLAG]... COMMAND
61 Like "thread apply", but applies COMMAND to Ada tasks.
64 Watchpoints can now be restricted to a specific Ada task.
66 maint set internal-error backtrace on|off
67 maint show internal-error backtrace
68 maint set internal-warning backtrace on|off
69 maint show internal-warning backtrace
70 GDB can now print a backtrace of itself when it encounters either an
71 internal-error, or an internal-warning. This is on by default for
72 internal-error and off by default for internal-warning.
75 Deprecated and replaced by "set logging enabled on|off".
77 set logging enabled on|off
79 These commands set or show whether logging is enabled or disabled.
82 You can now exit GDB by using the new command "exit", in addition to
83 the existing "quit" command.
85 set debug threads on|off
87 Print additional debug messages about thread creation and deletion.
89 set debug linux-nat on|off
91 These new commands replaced the old 'set debug lin-lwp' and 'show
92 debug lin-lwp' respectively. Turning this setting on prints debug
93 messages relating to GDB's handling of native Linux inferiors.
95 maint flush source-cache
96 Flush the contents of the source code cache.
98 maint set gnu-source-highlight enabled on|off
99 maint show gnu-source-highlight enabled
100 Whether GDB should use the GNU Source Highlight library for adding
101 styling to source code. When off, the library will not be used, even
102 when available. When GNU Source Highlight isn't used, or can't add
103 styling to a particular source file, then the Python Pygments
104 library will be used instead.
106 set suppress-cli-notifications (on|off)
107 show suppress-cli-notifications
108 This controls whether printing the notifications is suppressed for CLI.
109 CLI notifications occur when you change the selected context
110 (i.e., the current inferior, thread and/or the frame), or when
111 the program being debugged stops (e.g., because of hitting a
112 breakpoint, completing source-stepping, an interrupt, etc.).
114 set style disassembler enabled on|off
115 show style disassembler enabled
116 If GDB is compiled with Python support, and the Python Pygments
117 package is available, then, when this setting is on, disassembler
118 output will have styling applied.
120 set ada source-charset
121 show ada source-charset
122 Set the character set encoding that is assumed for Ada symbols. Valid
123 values for this follow the values that can be passed to the GNAT
124 compiler via the '-gnati' option. The default is ISO-8859-1.
129 Printing of floating-point values with base-modifying formats like
130 /x has been changed to display the underlying bytes of the value in
131 the desired base. This was GDB's documented behavior, but was never
132 implemented correctly.
135 This command can now print a reply, if the reply includes
136 non-printable characters. Any non-printable characters are printed
137 as escaped hex, e.g. \x?? where '??' is replaces with the value of
138 the non-printable character.
141 The clone-inferior command now ensures that the TTY, CMD and ARGS
142 settings are copied from the original inferior to the new one.
143 All modifications to the environment variables done using the 'set
144 environment' or 'unset environment' commands are also copied to the new
147 set debug lin-lwp on|off
149 These commands have been removed from GDB. The new command 'set
150 debug linux-nat' and 'show debug linux-nat' should be used
154 This command now includes information about the width of the tui
155 windows in its output.
157 * GDB's Ada parser now supports an extension for specifying the exact
158 byte contents of a floating-point literal. This can be useful for
159 setting floating-point registers to a precise value without loss of
160 precision. The syntax is an extension of the based literal syntax.
161 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
162 of the floating-point type, and the "f" is the marker for floating
167 ** The '-add-inferior' with no option flags now inherits the
168 connection of the current inferior, this restores the behaviour of
169 GDB as it was prior to GDB 10.
171 ** The '-add-inferior' command now accepts a '--no-connection'
172 option, which causes the new inferior to start without a
177 GNU/Linux/LoongArch loongarch*-*-linux*
181 ** New function gdb.add_history(), which takes a gdb.Value object
182 and adds the value it represents to GDB's history list. An
183 integer, the index of the new item in the history list, is
186 ** New function gdb.history_count(), which returns the number of
187 values in GDB's value history.
189 ** New gdb.events.gdb_exiting event. This event is called with a
190 gdb.GdbExitingEvent object which has the read-only attribute
191 'exit_code', which contains the value of the GDB exit code. This
192 event is triggered once GDB decides it is going to exit, but
193 before GDB starts to clean up its internal state.
195 ** New function gdb.architecture_names(), which returns a list
196 containing all of the possible Architecture.name() values. Each
199 ** New function gdb.Architecture.integer_type(), which returns an
200 integer type given a size and a signed-ness.
202 ** New gdb.TargetConnection object type that represents a connection
203 (as displayed by the 'info connections' command). A sub-class,
204 gdb.RemoteTargetConnection, is used to represent 'remote' and
205 'extended-remote' connections.
207 ** The gdb.Inferior type now has a 'connection' property which is an
208 instance of gdb.TargetConnection, the connection used by this
209 inferior. This can be None if the inferior has no connection.
211 ** New 'gdb.events.connection_removed' event registry, which emits a
212 'gdb.ConnectionEvent' when a connection is removed from GDB.
213 This event has a 'connection' property, a gdb.TargetConnection
214 object for the connection being removed.
216 ** New gdb.connections() function that returns a list of all
217 currently active connections.
219 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
220 is equivalent to the existing 'maint packet' CLI command; it
221 allows a user specified packet to be sent to the remote target.
223 ** New function gdb.host_charset(), returns a string, which is the
224 name of the current host charset.
226 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
229 ** New gdb.with_parameter(NAME, VALUE). This returns a context
230 manager that temporarily sets the gdb parameter NAME to VALUE,
231 then resets it when the context is exited.
233 ** The gdb.Value.format_string method now takes a 'styling'
234 argument, which is a boolean. When true, the returned string can
235 include escape sequences to apply styling. The styling will only
236 be present if styling is otherwise turned on in GDB (see 'help
237 set styling'). When false, which is the default if the argument
238 is not given, then no styling is applied to the returned string.
240 ** New read-only attribute gdb.InferiorThread.details, which is
241 either a string, containing additional, target specific thread
242 state information, or None, if there is no such additional
245 ** New read-only attribute gdb.Type.is_scalar, which is True for
246 scalar types, and False for all other types.
248 ** New read-only attribute gdb.Type.is_signed. This attribute
249 should only be read when Type.is_scalar is True, and will be True
250 for signed types, and False for all other types. Attempting to
251 read this attribute for non-scalar types will raise a ValueError.
253 ** It is now possible to add GDB/MI commands implemented in Python.
255 * New features in the GDB remote stub, GDBserver
257 ** GDBserver is now supported on OpenRISC GNU/Linux.
259 * New native configurations
261 GNU/Linux/OpenRISC or1k*-*-linux*
263 *** Changes in GDB 11
265 * The 'set disassembler-options' command now supports specifying options
268 * GDB now supports general memory tagging functionality if the underlying
269 architecture supports the proper primitives and hooks. Currently this is
270 enabled only for AArch64 MTE.
274 - Additional information when the inferior crashes with a SIGSEGV caused by
275 a memory tag violation.
277 - A new modifier 'm' for the "x" command, which displays allocation tags for a
278 particular memory range.
280 - Display of memory tag mismatches by "print", for addresses and
281 pointers, if memory tagging is supported by the architecture.
283 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
288 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
290 The MI -break-insert and -dprintf-insert commands now support a
291 new "--qualified" option that makes GDB interpret a specified
292 function name as a complete fully-qualified name. This is the
293 equivalent of the CLI's "break -qualified" and "dprintf
296 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
298 The MI -break-insert and -dprintf-insert commands now support a
299 '--force-condition' flag to forcibly define a condition even when
300 the condition is invalid at all locations of the breakpoint. This
301 is equivalent to the '-force-condition' flag of the CLI's "break"
304 ** '-break-condition --force'
306 The MI -break-condition command now supports a '--force' flag to
307 forcibly define a condition even when the condition is invalid at
308 all locations of the selected breakpoint. This is equivalent to
309 the '-force' flag of the CLI's "cond" command.
311 ** '-file-list-exec-source-files [--group-by-objfile]
312 [--basename | --dirname]
315 The existing -file-list-exec-source-files command now takes an
316 optional REGEXP which is used to filter the source files that are
317 included in the results.
319 By default REGEXP is matched against the full filename of the
320 source file. When one of --basename or --dirname is given then
321 REGEXP is only matched against the specified part of the full
324 When the optional --group-by-objfile flag is used the output
325 format is changed, the results are now a list of object files
326 (executable and libraries) with the source files that are
327 associated with each object file.
329 The results from -file-list-exec-source-files now include a
330 'debug-fully-read' field which takes the value 'true' or 'false'.
331 A 'true' value indicates the source file is from a compilation
332 unit that has had its debug information fully read in by GDB, a
333 value of 'false' indicates GDB has only performed a partial scan
334 of the debug information so far.
336 * GDB now supports core file debugging for x86_64 Cygwin programs.
338 * GDB will now look for the .gdbinit file in a config directory before
339 looking for ~/.gdbinit. The file is searched for in the following
340 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
341 $HOME/.gdbinit. On Apple hosts the search order is instead:
342 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
344 * GDB now supports fixed point types which are described in DWARF
345 as base types with a fixed-point encoding. Additionally, support
346 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
349 For Ada, this allows support for fixed point types without requiring
350 the use of the GNAT encoding (based on information added to the type's
351 name following a GNAT-specific format).
353 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
354 or ~/.gdbearlyinit if these files are present. These files are
355 processed earlier than any of the other initialization files and
356 can affect parts of GDB's startup that previously had already been
357 completed before the initialization files were read, for example
358 styling of the initial GDB greeting.
360 * GDB now has two new options "--early-init-command" and
361 "--early-init-eval-command" with corresponding short options "-eix"
362 and "-eiex" that allow options (that would normally appear in a
363 gdbearlyinit file) to be passed on the command line.
365 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
366 now understood by GDB, and can be used to describe the vector
367 registers of a target. The precise requirements of this register
368 feature are documented in the GDB manual.
370 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
371 supported by GDB and describes a new VPR register from the ARM MVE
372 (Helium) extension. See the GDB manual for more information.
376 ** TUI windows now support mouse actions. The mouse wheel scrolls
377 the appropriate window.
379 ** Key combinations that do not have a specific action on the
380 focused window are passed to GDB. For example, you now can use
381 Ctrl-Left/Ctrl-Right to move between words in the command window
382 regardless of which window is in focus. Previously you would
383 need to focus on the command window for such key combinations to
389 show debug event-loop
390 Control the display of debug output about GDB's event loop.
392 set print memory-tag-violations
393 show print memory-tag-violations
394 Control whether to display additional information about memory tag violations
395 when printing pointers and addresses. Architecture support for memory
396 tagging is required for this option to have an effect.
398 maintenance flush symbol-cache
399 maintenance flush register-cache
400 These new commands are equivalent to the already existing commands
401 'maintenance flush-symbol-cache' and 'flushregs' respectively.
403 maintenance flush dcache
404 A new command to flush the dcache.
406 maintenance info target-sections
407 Print GDB's internal target sections table.
410 Print the JIT code objects in the inferior known to GDB.
412 memory-tag show-logical-tag POINTER
413 Print the logical tag for POINTER.
414 memory-tag with-logical-tag POINTER TAG
415 Print POINTER with logical tag TAG.
416 memory-tag show-allocation-tag ADDRESS
417 Print the allocation tag for ADDRESS.
418 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
419 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
420 memory-tag check POINTER
421 Validate that POINTER's logical tag matches the allocation tag.
423 set startup-quietly on|off
425 When 'on', this causes GDB to act as if "-silent" were passed on the
426 command line. This command needs to be added to an early
427 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
430 set print type hex on|off
432 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
433 and offsets of struct members. When 'off', decimal notation is used.
435 set python ignore-environment on|off
436 show python ignore-environment
437 When 'on', this causes GDB's builtin Python to ignore any
438 environment variables that would otherwise affect how Python
439 behaves. This command needs to be added to an early initialization
440 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
442 set python dont-write-bytecode auto|on|off
443 show python dont-write-bytecode
444 When 'on', this causes GDB's builtin Python to not write any
445 byte-code (.pyc files) to disk. This command needs to be added to
446 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
447 order to affect GDB. When 'off' byte-code will always be written.
448 When set to 'auto' (the default) Python will check the
449 PYTHONDONTWRITEBYTECODE environment variable.
453 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
454 [-force-condition] [if CONDITION]
455 This command would previously refuse setting a breakpoint if the
456 CONDITION expression is invalid at a location. It now accepts and
457 defines the breakpoint if there is at least one location at which
458 the CONDITION is valid. The locations for which the CONDITION is
459 invalid, are automatically disabled. If CONDITION is invalid at all
460 of the locations, setting the breakpoint is still rejected. However,
461 the '-force-condition' flag can be used in this case for forcing GDB to
462 define the breakpoint, making all the current locations automatically
463 disabled. This may be useful if the user knows the condition will
464 become meaningful at a future location, e.g. due to a shared library
467 condition [-force] N COND
468 The behavior of this command is changed the same way for the 'break'
469 command as explained above. The '-force' flag can be used to force
470 GDB into defining the condition even when COND is invalid for all the
471 current locations of breakpoint N.
474 maintenance flush-symbol-cache
475 These commands are deprecated in favor of the new commands
476 'maintenance flush register-cache' and 'maintenance flush
477 symbol-cache' respectively.
479 set style version foreground COLOR
480 set style version background COLOR
481 set style version intensity VALUE
482 Control the styling of GDB's version number text.
485 When the ID parameter is omitted, then this command prints information
486 about the current inferior. When the ID parameter is present, the
487 behavior of the command is unchanged and have the inferior ID become
488 the current inferior.
490 maintenance info sections
491 The ALLOBJ keyword has been replaced with an -all-objects command
492 line flag. It is now possible to filter which sections are printed
493 even when -all-objects is passed.
495 ptype[/FLAGS] TYPE | EXPRESSION
496 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
497 notation is used when printing sizes and offsets of struct members.
498 When '/d' is set, decimal notation is used when printing sizes and
499 offsets of struct members. Default behavior is given by 'show print
503 The info sources command output has been restructured. The results
504 are now based around a list of objfiles (executable and libraries),
505 and for each objfile the source files that are part of that objfile
508 * Removed targets and native configurations
510 ARM Symbian arm*-*-symbianelf*
515 Request the remote to send allocation tags for a particular memory range.
517 Request the remote to store the specified allocation tags to the requested
522 ** Improved support for rvalue reference values:
523 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
524 value-referenced-value procedure now handles rvalue reference
527 ** New procedures for obtaining value variants:
528 value-reference-value, value-rvalue-reference-value and
531 ** Temporary breakpoints can now be created with make-breakpoint and
532 tested for using breakpoint-temporary?.
536 ** Inferior objects now contain a read-only 'connection_num' attribute that
537 gives the connection number as seen in 'info connections' and
540 ** New method gdb.Frame.level() which returns the stack level of the
543 ** New method gdb.PendingFrame.level() which returns the stack level
546 ** When hitting a catchpoint, the Python API will now emit a
547 gdb.BreakpointEvent rather than a gdb.StopEvent. The
548 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
550 ** Python TUI windows can now receive mouse click events. If the
551 Window object implements the click method, it is called for each
552 mouse click event in this window.
554 *** Changes in GDB 10
556 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
557 and "org.gnu.gdb.arc.aux". The old names are still supported but
558 must be considered obsolete. They will be deprecated after some
561 * Help and apropos commands will now show the documentation of a
562 command only once, even if that command has one or more aliases.
563 These commands now show the command name, then all of its aliases,
564 and finally the description of the command.
566 * 'help aliases' now shows only the user defined aliases. GDB predefined
567 aliases are shown together with their aliased command.
569 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
570 debugging information as well as source code.
572 When built with debuginfod, GDB can automatically query debuginfod
573 servers for the separate debug files and source code of the executable
576 To build GDB with debuginfod, pass --with-debuginfod to configure (this
577 requires libdebuginfod, the debuginfod client library).
579 debuginfod is distributed with elfutils, starting with version 0.178.
581 You can get the latest version from https://sourceware.org/elfutils.
583 * Multi-target debugging support
585 GDB now supports debugging multiple target connections
586 simultaneously. For example, you can now have each inferior
587 connected to different remote servers running in different machines,
588 or have one inferior debugging a local native process, an inferior
589 debugging a core dump, etc.
591 This support is experimental and comes with some limitations -- you
592 can only resume multiple targets simultaneously if all targets
593 support non-stop mode, and all remote stubs or servers must support
594 the same set of remote protocol features exactly. See also "info
595 connections" and "add-inferior -no-connection" below, and "maint set
596 target-non-stop" in the user manual.
598 * New features in the GDB remote stub, GDBserver
600 ** GDBserver is now supported on ARC GNU/Linux.
602 ** GDBserver is now supported on RISC-V GNU/Linux.
604 ** GDBserver no longer supports these host triplets:
615 i[34567]86-*-mingw32ce*
617 * Debugging MS-Windows processes now sets $_exitsignal when the
618 inferior is terminated by a signal, instead of setting $_exitcode.
620 * Multithreaded symbol loading has now been enabled by default on systems
621 that support it (see entry for GDB 9, below), providing faster
622 performance for programs with many symbols.
624 * The $_siginfo convenience variable now also works on Windows targets,
625 and will display the EXCEPTION_RECORD of the last handled exception.
627 * TUI windows can now be arranged horizontally.
629 * The command history filename can now be set to the empty string
630 either using 'set history filename' or by setting 'GDBHISTFILE=' in
631 the environment. The effect of setting this filename to the empty
632 string is that GDB will not try to load any previous command
635 * On Windows targets, it is now possible to debug 32-bit programs with a
640 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
641 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
642 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
643 running process, this new option indicates whether to detect
644 a mismatch between the current executable file loaded by GDB and the
645 executable file used to start the process. If 'ask', the default,
646 display a warning and ask the user whether to load the process
647 executable file; if 'warn', just display a warning; if 'off', don't
648 attempt to detect a mismatch.
650 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
651 Define a new TUI layout, specifying its name and the windows that
654 maintenance print xml-tdesc [FILE]
655 Prints the current target description as an XML document. If the
656 optional FILE is provided (which is an XML target description) then
657 the target description is read from FILE into GDB, and then
660 maintenance print core-file-backed-mappings
661 Prints file-backed mappings loaded from a core file's note section.
662 Output is expected to be similar to that of "info proc mappings".
664 set debug fortran-array-slicing on|off
665 show debug fortran-array-slicing
666 Print debugging when taking slices of Fortran arrays.
668 set fortran repack-array-slices on|off
669 show fortran repack-array-slices
670 When taking slices from Fortran arrays and strings, if the slice is
671 non-contiguous within the original value then, when this option is
672 on, the new value will be repacked into a single contiguous value.
673 When this option is off, then the value returned will consist of a
674 descriptor that describes the slice within the memory of the
675 original parent value.
679 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
680 The alias command can now specify default args for an alias.
681 GDB automatically prepends the alias default args to the argument list
682 provided explicitly by the user.
683 For example, to have a backtrace with full details, you can define
685 'alias bt_ALL = backtrace -entry-values both -frame-arg all
686 -past-main -past-entry -full'.
687 Alias default arguments can also use a set of nested 'with' commands,
688 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
689 defines the alias pp10 that will pretty print a maximum of 10 elements
690 of the given expression (if the expression is an array).
694 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
700 ** gdb.register_window_type can be used to implement new TUI windows
703 ** Dynamic types can now be queried. gdb.Type has a new attribute,
704 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
705 field of a dynamic type may have None for its "bitpos" attribute
708 ** Commands written in Python can be in the "TUI" help class by
709 registering with the new constant gdb.COMMAND_TUI.
711 ** New method gdb.PendingFrame.architecture () to retrieve the
712 architecture of the pending frame.
714 ** New gdb.Architecture.registers method that returns a
715 gdb.RegisterDescriptorIterator object, an iterator that returns
716 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
717 way to query the registers available for an architecture.
719 ** New gdb.Architecture.register_groups method that returns a
720 gdb.RegisterGroupIterator object, an iterator that returns
721 gdb.RegisterGroup objects. The new RegisterGroup is a way to
722 discover the available register groups.
726 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
728 ** Procedures 'memory-port-read-buffer-size',
729 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
730 and 'set-memory-port-write-buffer-size!' are deprecated. When
731 using Guile 2.2 and later, users who need to control the size of
732 a memory port's internal buffer can use the 'setvbuf' procedure.
736 * 'thread-exited' event is now available in the annotations interface.
738 * New built-in convenience variables $_gdb_major and $_gdb_minor
739 provide the GDB version. They are handy for conditionally using
740 features available only in or since specific GDB versions, in
741 scripts that should work error-free with many different versions,
742 such as in system-wide init files.
744 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
745 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
746 of the GDB settings and the GDB maintenance settings. They are handy
747 for changing the logic of user defined commands depending on the
748 current GDB settings.
750 * GDB now supports Thread Local Storage (TLS) variables on several
751 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
752 architectures require kernel changes. TLS is not yet supported for
753 amd64 and i386 process core dumps.
755 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
756 addresses that required unmasking are shown in the backtrace with the
759 * Two new convenience functions $_cimag and $_creal that extract the
760 imaginary and real parts respectively from complex numbers.
762 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
763 provide the exitcode or exit status of the shell commands launched by
764 GDB commands such as "shell", "pipe" and "make".
766 * The command define-prefix can now define user defined prefix commands.
767 User defined commands can now be defined using these user defined prefix
770 * Command names can now use the . character.
772 * The RX port now supports XML target descriptions.
774 * GDB now shows the Ada task names at more places, e.g. in task switching
777 * GDB can now be compiled with Python 3 on Windows.
779 * New convenience variable $_ada_exception holds the address of the
780 Ada exception being thrown. This is set by Ada-related catchpoints.
782 * GDB can now place breakpoints on nested functions and subroutines in
783 Fortran code. The '::' operator can be used between parent and
784 child scopes when placing breakpoints, for example:
786 (gdb) break outer_function::inner_function
788 The 'outer_function::' prefix is only needed if 'inner_function' is
789 not visible in the current scope.
791 * In addition to the system-wide gdbinit file, if configured with
792 --with-system-gdbinit-dir, GDB will now also load files in that directory
793 as system gdbinit files, unless the -nx or -n flag is provided. Files
794 with extensions .gdb, .py and .scm are supported as long as GDB was
795 compiled with support for that language.
797 * GDB now supports multithreaded symbol loading for higher performance.
798 This feature is still in testing, so it is disabled by default. You
799 can turn it on using 'maint set worker-threads unlimited'.
803 ** The gdb.Value type has a new method 'format_string' which returns a
804 string representing the value. The formatting is controlled by the
805 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
806 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
807 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
809 ** gdb.Type has a new property 'objfile' which returns the objfile the
812 ** The frame information printed by the python frame filtering code
813 is now consistent with what the 'backtrace' command prints when
814 there are no filters, or when the 'backtrace' '-no-filters' option
817 ** The new function gdb.lookup_static_symbol can be used to look up
818 symbols with static linkage.
820 ** The new function gdb.lookup_static_symbols can be used to look up
821 all static symbols with static linkage.
823 ** gdb.Objfile has new methods 'lookup_global_symbol' and
824 'lookup_static_symbol' to lookup a symbol from this objfile only.
826 ** gdb.Block now supports the dictionary syntax for accessing symbols in
827 this block (e.g. block['local_variable']).
831 | [COMMAND] | SHELL_COMMAND
832 | -d DELIM COMMAND DELIM SHELL_COMMAND
833 pipe [COMMAND] | SHELL_COMMAND
834 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
835 Executes COMMAND and sends its output to SHELL_COMMAND.
836 With no COMMAND, repeat the last executed command
837 and send its output to SHELL_COMMAND.
839 define-prefix COMMAND
840 Define or mark a command as a user-defined prefix command.
842 with SETTING [VALUE] [-- COMMAND]
843 w SETTING [VALUE] [-- COMMAND]
844 Temporarily set SETTING, run COMMAND, and restore SETTING.
845 Usage: with SETTING -- COMMAND
846 With no COMMAND, repeats the last executed command.
847 SETTING is any GDB setting you can change with the "set"
848 subcommands. For example, 'with language c -- print someobj'
849 temporarily switches to the C language in order to print someobj.
850 Settings can be combined: 'w lang c -- w print elements unlimited --
851 usercmd' switches to the C language and runs usercmd with no limit
852 of array elements to print.
854 maint with SETTING [VALUE] [-- COMMAND]
855 Like "with", but works with "maintenance set" settings.
857 set may-call-functions [on|off]
858 show may-call-functions
859 This controls whether GDB will attempt to call functions in
860 the program, such as with expressions in the print command. It
861 defaults to on. Calling functions in the program being debugged
862 can have undesired side effects. It is now possible to forbid
863 such function calls. If function calls are forbidden, GDB will throw
864 an error when a command (such as print expression) calls a function
867 set print finish [on|off]
869 This controls whether the `finish' command will display the value
870 that is returned by the current function. When `off', the value is
871 still entered into the value history, but it is not printed. The
876 Allows deeply nested structures to be simplified when printing by
877 replacing deeply nested parts (beyond the max-depth) with ellipses.
878 The default max-depth is 20, but this can be set to unlimited to get
879 the old behavior back.
881 set print raw-values [on|off]
882 show print raw-values
883 By default, GDB applies the enabled pretty printers when printing a
884 value. This allows to ignore the enabled pretty printers for a series
885 of commands. The default is 'off'.
887 set logging debugredirect [on|off]
888 By default, GDB debug output will go to both the terminal and the logfile.
889 Set if you want debug output to go only to the log file.
891 set style title foreground COLOR
892 set style title background COLOR
893 set style title intensity VALUE
894 Control the styling of titles.
896 set style highlight foreground COLOR
897 set style highlight background COLOR
898 set style highlight intensity VALUE
899 Control the styling of highlightings.
901 maint set worker-threads
902 maint show worker-threads
903 Control the number of worker threads that can be used by GDB. The
904 default is 0. "unlimited" lets GDB choose a number that is
905 reasonable. Currently worker threads are only used when demangling
906 the names of linker symbols.
908 set style tui-border foreground COLOR
909 set style tui-border background COLOR
910 Control the styling of TUI borders.
912 set style tui-active-border foreground COLOR
913 set style tui-active-border background COLOR
914 Control the styling of the active TUI border.
916 maint set test-settings KIND
917 maint show test-settings KIND
918 A set of commands used by the testsuite for exercising the settings
921 maint set tui-resize-message [on|off]
922 maint show tui-resize-message
923 Control whether GDB prints a message each time the terminal is
924 resized when in TUI mode. This is primarily useful for testing the
927 set print frame-info [short-location|location|location-and-address
928 |source-and-location|source-line|auto]
929 show print frame-info
930 This controls what frame information is printed by the commands printing
931 a frame. This setting will e.g. influence the behaviour of 'backtrace',
932 'frame', 'stepi'. The python frame filtering also respect this setting.
933 The 'backtrace' '-frame-info' option can override this global setting.
935 set tui compact-source
936 show tui compact-source
938 Enable the "compact" display mode for the TUI source window. The
939 compact display uses only as much space as is needed for the line
940 numbers in the current file, and only a single space to separate the
941 line numbers from the source.
943 info modules [-q] [REGEXP]
944 Return a list of Fortran modules matching REGEXP, or all modules if
947 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
948 Return a list of functions within all modules, grouped by module.
949 The list of functions can be restricted with the optional regular
950 expressions. MODULE_REGEXP matches against the module name,
951 TYPE_REGEXP matches against the function type signature, and REGEXP
952 matches against the function name.
954 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
955 Return a list of variables within all modules, grouped by module.
956 The list of variables can be restricted with the optional regular
957 expressions. MODULE_REGEXP matches against the module name,
958 TYPE_REGEXP matches against the variable type, and REGEXP matches
959 against the variable name.
961 set debug remote-packet-max-chars
962 show debug remote-packet-max-chars
963 Controls the number of characters to output in a remote packet when using
965 The default is 512 bytes.
968 Lists the target connections currently in use.
973 The "help" command uses the title style to enhance the
974 readibility of its output by styling the classes and
978 Similarly to "help", the "apropos" command also uses the
979 title style for the command names. "apropos" accepts now
980 a flag "-v" (verbose) to show the full documentation
981 of matching commands and to use the highlight style to mark
982 the documentation parts matching REGEXP.
986 The GDB printf and eval commands can now print C-style and Ada-style
987 string convenience variables without calling functions in the program.
988 This allows to do formatted printing of strings without having
989 a running inferior, or when debugging a core dump.
991 info sources [-dirname | -basename] [--] [REGEXP]
992 This command has now optional arguments to only print the files
993 whose names match REGEXP. The arguments -dirname and -basename
994 allow to restrict matching respectively to the dirname and basename
998 The "show style" and its subcommands are now styling
999 a style name in their output using its own style, to help
1000 the user visualize the different styles.
1002 set print frame-arguments
1003 The new value 'presence' indicates to only indicate the presence of
1004 arguments using ..., instead of printing argument names and values.
1006 set print raw-frame-arguments
1007 show print raw-frame-arguments
1009 These commands replace the similarly-named "set/show print raw
1010 frame-arguments" commands (now with a dash instead of a space). The
1011 old commands are now deprecated and may be removed in a future
1014 add-inferior [-no-connection]
1015 The add-inferior command now supports a "-no-connection" flag that
1016 makes the new inferior start with no target connection associated.
1017 By default, the new inferior inherits the target connection of the
1018 current inferior. See also "info connections".
1021 This command's output now includes a new "Connection" column
1022 indicating which target connection an inferior is bound to. See
1023 "info connections" above.
1025 maint test-options require-delimiter
1026 maint test-options unknown-is-error
1027 maint test-options unknown-is-operand
1028 maint show test-options-completion-result
1029 Commands used by the testsuite to validate the command options
1032 focus, winheight, +, -, >, <
1033 These commands are now case-sensitive.
1035 * New command options, command completion
1037 GDB now has a standard infrastructure to support dash-style command
1038 options ('-OPT'). One benefit is that commands that use it can
1039 easily support completion of command line arguments. Try "CMD
1040 -[TAB]" or "help CMD" to find options supported by a command. Over
1041 time, we intend to migrate most commands to this infrastructure. A
1042 number of commands got support for new command options in this
1045 ** The "print" and "compile print" commands now support a number of
1046 options that allow overriding relevant global print settings as
1047 set by "set print" subcommands:
1051 -array-indexes [on|off]
1052 -elements NUMBER|unlimited
1056 -raw-values [on|off]
1057 -repeats NUMBER|unlimited
1058 -static-members [on|off]
1063 Note that because the "print"/"compile print" commands accept
1064 arbitrary expressions which may look like options (including
1065 abbreviations), if you specify any command option, then you must
1066 use a double dash ("--") to mark the end of argument processing.
1068 ** The "backtrace" command now supports a number of options that
1069 allow overriding relevant global print settings as set by "set
1070 backtrace" and "set print" subcommands:
1072 -entry-values no|only|preferred|if-needed|both|compact|default
1073 -frame-arguments all|scalars|none
1074 -raw-frame-arguments [on|off]
1075 -frame-info auto|source-line|location|source-and-location
1076 |location-and-address|short-location
1078 -past-entry [on|off]
1080 In addition, the full/no-filters/hide qualifiers are now also
1081 exposed as command options too:
1087 ** The "frame apply", "tfaas" and "faas" commands similarly now
1088 support the following options:
1091 -past-entry [on|off]
1093 ** The new "info sources" options -dirname and -basename options
1094 are using the standard '-OPT' infrastructure.
1096 All options above can also be abbreviated. The argument of boolean
1097 (on/off) options can be 0/1 too, and also the argument is assumed
1098 "on" if omitted. This allows writing compact command invocations,
1101 (gdb) p -ra -p -o 0 -- *myptr
1103 The above is equivalent to:
1105 (gdb) print -raw-values -pretty -object off -- *myptr
1107 ** The "info types" command now supports the '-q' flag to disable
1108 printing of some header information in a similar fashion to "info
1109 variables" and "info functions".
1111 ** The "info variables", "info functions", and "whereis" commands
1112 now take a '-n' flag that excludes non-debug symbols (symbols
1113 from the symbol table, not from the debug info such as DWARF)
1116 * Completion improvements
1118 ** GDB can now complete the options of the "thread apply all" and
1119 "taas" commands, and their "-ascending" option can now be
1122 ** GDB can now complete the options of the "info threads", "info
1123 functions", "info variables", "info locals", and "info args"
1126 ** GDB can now complete the options of the "compile file" and
1127 "compile code" commands. The "compile file" command now
1128 completes on filenames.
1130 ** GDB can now complete the backtrace command's
1131 "full/no-filters/hide" qualifiers.
1133 * In settings, you can now abbreviate "unlimited".
1135 E.g., "set print elements u" is now equivalent to "set print
1136 elements unlimited".
1141 This lists all the possible completions for the rest of the line, if it
1142 were to be given as a command itself. This is intended for use by MI
1143 frontends in cases when separate CLI and MI channels cannot be used.
1145 -catch-throw, -catch-rethrow, and -catch-catch
1146 These can be used to catch C++ exceptions in a similar fashion to
1147 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1149 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1150 These commands are the MI equivalent of the CLI commands 'info
1151 functions', 'info types', and 'info variables' respectively.
1153 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1156 -symbol-info-module-functions and -symbol-info-module-variables.
1157 These commands are the MI equivalent of the CLI commands 'info
1158 module functions' and 'info module variables'.
1162 ** The default version of the MI interpreter is now 3 (-i=mi3).
1164 ** The output of information about multi-location breakpoints (which is
1165 syntactically incorrect in MI 2) has changed in MI 3. This affects
1166 the following commands and events:
1170 - =breakpoint-created
1171 - =breakpoint-modified
1173 The -fix-multi-location-breakpoint-output command can be used to enable
1174 this behavior with previous MI versions.
1176 ** Backtraces and frames include a new optional field addr_flags which is
1177 given after the addr field. On AArch64 this contains PAC if the address
1178 has been masked in the frame. On all other targets the field is not
1183 The testsuite now creates the files gdb.cmd (containing the arguments
1184 used to launch GDB) and gdb.in (containing all the commands sent to
1185 GDB) in the output directory for each test script. Multiple invocations
1186 are appended with .1, .2, .3 etc.
1188 * Building GDB and GDBserver now requires GNU make >= 3.82.
1190 Using another implementation of the make program or an earlier version of
1191 GNU make to build GDB or GDBserver is not supported.
1193 * Building GDB now requires GNU readline >= 7.0.
1195 GDB now bundles GNU readline 8.0, but if you choose to use
1196 --with-system-readline, only readline >= 7.0 can be used.
1198 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1199 from .inputrc to bind keys in this keymap. This feature is only
1200 available when gdb is built against GNU readline 8.0 or later.
1202 * Removed targets and native configurations
1204 GDB no longer supports debugging the Cell Broadband Engine. This includes
1205 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1206 of Cell/B.E. applications that use both the PPU and SPU architectures.
1212 * Removed targets and native configurations
1214 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1215 sparc*-*-solaris2.10
1217 *** Changes in GDB 8.3
1219 * GDB and GDBserver now support access to additional registers on
1220 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1223 * GDB now has experimental support for the compilation and injection of
1224 C++ source code into the inferior. This beta release does not include
1225 support for several language features, such as templates, constructors,
1228 This feature requires GCC 7.1 or higher built with libcp1.so
1231 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1232 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1233 'ADDRESS:PORT' method.
1235 * DWARF index cache: GDB can now automatically save indices of DWARF
1236 symbols on disk to speed up further loading of the same binaries.
1238 * Ada task switching is now supported on aarch64-elf targets when
1239 debugging a program using the Ravenscar Profile. For more information,
1240 see the "Tasking Support when using the Ravenscar Profile" section
1241 in the GDB user manual.
1243 * GDB in batch mode now exits with status 1 if the last command to be
1246 * The RISC-V target now supports target descriptions.
1248 * System call catchpoints now support system call aliases on FreeBSD.
1249 When the ABI of a system call changes in FreeBSD, this is
1250 implemented by leaving a compatibility system call using the old ABI
1251 at the existing number and allocating a new system call number for
1252 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1253 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1254 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1255 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1256 so that a system call catchpoint for the 'kevent' system call will
1257 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1258 binaries. This ensures that 'kevent' system calls are caught for
1259 binaries using either the old or new ABIs.
1261 * Terminal styling is now available for the CLI and the TUI. GNU
1262 Source Highlight can additionally be used to provide styling of
1263 source code snippets. See the "set style" commands, below, for more
1266 * Removed support for old demangling styles arm, edg, gnu, hp and
1271 set debug compile-cplus-types
1272 show debug compile-cplus-types
1273 Control the display of debug output about type conversion in the
1274 C++ compile feature. Commands have no effect while compiling
1275 for other languages.
1279 Control whether debug output about files/functions skipping is
1282 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1283 Apply a command to some frames.
1284 FLAG arguments allow to control what output to produce and how to handle
1285 errors raised when applying COMMAND to a frame.
1288 Apply a command to all threads (ignoring errors and empty output).
1289 Shortcut for 'thread apply all -s COMMAND'.
1292 Apply a command to all frames (ignoring errors and empty output).
1293 Shortcut for 'frame apply all -s COMMAND'.
1296 Apply a command to all frames of all threads (ignoring errors and empty
1298 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1300 maint set dwarf unwinders (on|off)
1301 maint show dwarf unwinders
1302 Control whether DWARF unwinders can be used.
1305 Display a list of open files for a process.
1309 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1310 These commands all now take a frame specification which
1311 is either a frame level, or one of the keywords 'level', 'address',
1312 'function', or 'view' followed by a parameter. Selecting a frame by
1313 address, or viewing a frame outside the current backtrace now
1314 requires the use of a keyword. Selecting a frame by level is
1315 unchanged. The MI comment "-stack-select-frame" is unchanged.
1317 target remote FILENAME
1318 target extended-remote FILENAME
1319 If FILENAME is a Unix domain socket, GDB will attempt to connect
1320 to this socket instead of opening FILENAME as a character device.
1322 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1323 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1324 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1325 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1326 These commands can now print only the searched entities
1327 matching the provided regexp(s), giving a condition
1328 on the entity names or entity types. The flag -q disables
1329 printing headers or informations messages.
1335 These commands now determine the syntax for the shown entities
1336 according to the language chosen by `set language'. In particular,
1337 `set language auto' means to automatically choose the language of
1340 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1341 The 'thread apply' command accepts new FLAG arguments.
1342 FLAG arguments allow to control what output to produce and how to handle
1343 errors raised when applying COMMAND to a thread.
1345 set tui tab-width NCHARS
1346 show tui tab-width NCHARS
1347 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1349 set style enabled [on|off]
1351 Enable or disable terminal styling. Styling is enabled by default
1352 on most hosts, but disabled by default when in batch mode.
1354 set style sources [on|off]
1356 Enable or disable source code styling. Source code styling is
1357 enabled by default, but only takes effect if styling in general is
1358 enabled, and if GDB was linked with GNU Source Highlight.
1360 set style filename foreground COLOR
1361 set style filename background COLOR
1362 set style filename intensity VALUE
1363 Control the styling of file names.
1365 set style function foreground COLOR
1366 set style function background COLOR
1367 set style function intensity VALUE
1368 Control the styling of function names.
1370 set style variable foreground COLOR
1371 set style variable background COLOR
1372 set style variable intensity VALUE
1373 Control the styling of variable names.
1375 set style address foreground COLOR
1376 set style address background COLOR
1377 set style address intensity VALUE
1378 Control the styling of addresses.
1382 ** The '-data-disassemble' MI command now accepts an '-a' option to
1383 disassemble the whole function surrounding the given program
1384 counter value or function name. Support for this feature can be
1385 verified by using the "-list-features" command, which should
1386 contain "data-disassemble-a-option".
1388 ** Command responses and notifications that include a frame now include
1389 the frame's architecture in a new "arch" attribute.
1391 * New native configurations
1393 GNU/Linux/RISC-V riscv*-*-linux*
1394 FreeBSD/riscv riscv*-*-freebsd*
1398 GNU/Linux/RISC-V riscv*-*-linux*
1399 CSKY ELF csky*-*-elf
1400 CSKY GNU/LINUX csky*-*-linux
1401 FreeBSD/riscv riscv*-*-freebsd*
1403 GNU/Linux/OpenRISC or1k*-*-linux*
1407 GDB no longer supports native debugging on versions of MS-Windows
1412 ** GDB no longer supports Python versions less than 2.6.
1414 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1415 space associated to that inferior.
1417 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1418 of objfiles associated to that program space.
1420 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1421 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1424 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1425 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1426 correct and did not work properly.
1428 ** The gdb.Value type has a new constructor, which is used to construct a
1429 gdb.Value from a Python buffer object and a gdb.Type.
1435 Enable or disable the undefined behavior sanitizer. This is
1436 disabled by default, but passing --enable-ubsan=yes or
1437 --enable-ubsan=auto to configure will enable it. Enabling this can
1438 cause a performance penalty. The undefined behavior sanitizer was
1439 first introduced in GCC 4.9.
1441 *** Changes in GDB 8.2
1443 * The 'set disassembler-options' command now supports specifying options
1444 for the MIPS target.
1446 * The 'symbol-file' command now accepts an '-o' option to add a relative
1447 offset to all sections.
1449 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1450 a relative offset to all sections, but it allows to override the load
1451 address of individual sections using '-s'.
1453 * The 'add-symbol-file' command no longer requires the second argument
1454 (address of the text section).
1456 * The endianness used with the 'set endian auto' mode in the absence of
1457 an executable selected for debugging is now the last endianness chosen
1458 either by one of the 'set endian big' and 'set endian little' commands
1459 or by inferring from the last executable used, rather than the startup
1462 * The pager now allows a "c" response, meaning to disable the pager
1463 for the rest of the current command.
1465 * The commands 'info variables/functions/types' now show the source line
1466 numbers of symbol definitions when available.
1468 * 'info proc' now works on running processes on FreeBSD systems and core
1469 files created on FreeBSD systems.
1471 * C expressions can now use _Alignof, and C++ expressions can now use
1474 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1475 the vector length while the process is running.
1481 Control display of debugging info regarding the FreeBSD native target.
1483 set|show varsize-limit
1484 This new setting allows the user to control the maximum size of Ada
1485 objects being printed when those objects have a variable type,
1486 instead of that maximum size being hardcoded to 65536 bytes.
1488 set|show record btrace cpu
1489 Controls the processor to be used for enabling errata workarounds for
1490 branch trace decode.
1492 maint check libthread-db
1493 Run integrity checks on the current inferior's thread debugging
1496 maint set check-libthread-db (on|off)
1497 maint show check-libthread-db
1498 Control whether to run integrity checks on inferior specific thread
1499 debugging libraries as they are loaded. The default is not to
1500 perform such checks.
1504 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1506 ** The commands attached to a breakpoint can be set by assigning to
1507 the breakpoint's "commands" field.
1509 ** gdb.execute can now execute multi-line gdb commands.
1511 ** The new functions gdb.convenience_variable and
1512 gdb.set_convenience_variable can be used to get and set the value
1513 of convenience variables.
1515 ** A gdb.Parameter will no longer print the "set" help text on an
1516 ordinary "set"; instead by default a "set" will be silent unless
1517 the get_set_string method returns a non-empty string.
1521 RiscV ELF riscv*-*-elf
1523 * Removed targets and native configurations
1525 m88k running OpenBSD m88*-*-openbsd*
1526 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1527 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1528 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1530 * Aarch64/Linux hardware watchpoints improvements
1532 Hardware watchpoints on unaligned addresses are now properly
1533 supported when running Linux kernel 4.10 or higher: read and access
1534 watchpoints are no longer spuriously missed, and all watchpoints
1535 lengths between 1 and 8 bytes are supported. On older kernels,
1536 watchpoints set on unaligned addresses are no longer missed, with
1537 the tradeoff that there is a possibility of false hits being
1542 --enable-codesign=CERT
1543 This can be used to invoke "codesign -s CERT" after building gdb.
1544 This option is useful on macOS, where code signing is required for
1545 gdb to work properly.
1547 --disable-gdbcli has been removed
1548 This is now silently accepted, but does nothing.
1550 *** Changes in GDB 8.1
1552 * GDB now supports dynamically creating arbitrary register groups specified
1553 in XML target descriptions. This allows for finer grain grouping of
1554 registers on systems with a large amount of registers.
1556 * The 'ptype' command now accepts a '/o' flag, which prints the
1557 offsets and sizes of fields in a struct, like the pahole(1) tool.
1559 * New "--readnever" command line option instructs GDB to not read each
1560 symbol file's symbolic debug information. This makes startup faster
1561 but at the expense of not being able to perform symbolic debugging.
1562 This option is intended for use cases where symbolic debugging will
1563 not be used, e.g., when you only need to dump the debuggee's core.
1565 * GDB now uses the GNU MPFR library, if available, to emulate target
1566 floating-point arithmetic during expression evaluation when the target
1567 uses different floating-point formats than the host. At least version
1568 3.1 of GNU MPFR is required.
1570 * GDB now supports access to the guarded-storage-control registers and the
1571 software-based guarded-storage broadcast control registers on IBM z14.
1573 * On Unix systems, GDB now supports transmitting environment variables
1574 that are to be set or unset to GDBserver. These variables will
1575 affect the environment to be passed to the remote inferior.
1577 To inform GDB of environment variables that are to be transmitted to
1578 GDBserver, use the "set environment" command. Only user set
1579 environment variables are sent to GDBserver.
1581 To inform GDB of environment variables that are to be unset before
1582 the remote inferior is started by the GDBserver, use the "unset
1583 environment" command.
1585 * Completion improvements
1587 ** GDB can now complete function parameters in linespecs and
1588 explicit locations without quoting. When setting breakpoints,
1589 quoting around functions names to help with TAB-completion is
1590 generally no longer necessary. For example, this now completes
1593 (gdb) b function(in[TAB]
1594 (gdb) b function(int)
1596 Related, GDB is no longer confused with completing functions in
1597 C++ anonymous namespaces:
1600 (gdb) b (anonymous namespace)::[TAB][TAB]
1601 (anonymous namespace)::a_function()
1602 (anonymous namespace)::b_function()
1604 ** GDB now has much improved linespec and explicit locations TAB
1605 completion support, that better understands what you're
1606 completing and offers better suggestions. For example, GDB no
1607 longer offers data symbols as possible completions when you're
1608 setting a breakpoint.
1610 ** GDB now TAB-completes label symbol names.
1612 ** The "complete" command now mimics TAB completion accurately.
1614 * New command line options (gcore)
1617 Dump all memory mappings.
1619 * Breakpoints on C++ functions are now set on all scopes by default
1621 By default, breakpoints on functions/methods are now interpreted as
1622 specifying all functions with the given name ignoring missing
1623 leading scopes (namespaces and classes).
1625 For example, assuming a C++ program with symbols named:
1630 both commands "break func()" and "break B::func()" set a breakpoint
1633 You can use the new flag "-qualified" to override this. This makes
1634 GDB interpret the specified function name as a complete
1635 fully-qualified name instead. For example, using the same C++
1636 program, the "break -q B::func" command sets a breakpoint on
1637 "B::func", only. A parameter has been added to the Python
1638 gdb.Breakpoint constructor to achieve the same result when creating
1639 a breakpoint from Python.
1641 * Breakpoints on functions marked with C++ ABI tags
1643 GDB can now set breakpoints on functions marked with C++ ABI tags
1644 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1645 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1647 Functions with a C++11 abi tag are demangled/displayed like this:
1649 function[abi:cxx11](int)
1652 You can now set a breakpoint on such functions simply as if they had
1655 (gdb) b function(int)
1657 Or if you need to disambiguate between tags, like:
1659 (gdb) b function[abi:other_tag](int)
1661 Tab completion was adjusted accordingly as well.
1665 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1666 gdb.new_thread are emitted. See the manual for further
1667 description of these.
1669 ** A new function, "gdb.rbreak" has been added to the Python API.
1670 This function allows the setting of a large number of breakpoints
1671 via a regex pattern in Python. See the manual for further details.
1673 ** Python breakpoints can now accept explicit locations. See the
1674 manual for a further description of this feature.
1677 * New features in the GDB remote stub, GDBserver
1679 ** GDBserver is now able to start inferior processes with a
1680 specified initial working directory.
1682 The user can set the desired working directory to be used from
1683 GDB using the new "set cwd" command.
1685 ** New "--selftest" command line option runs some GDBserver self
1686 tests. These self tests are disabled in releases.
1688 ** On Unix systems, GDBserver now does globbing expansion and variable
1689 substitution in inferior command line arguments.
1691 This is done by starting inferiors using a shell, like GDB does.
1692 See "set startup-with-shell" in the user manual for how to disable
1693 this from GDB when using "target extended-remote". When using
1694 "target remote", you can disable the startup with shell by using the
1695 new "--no-startup-with-shell" GDBserver command line option.
1697 ** On Unix systems, GDBserver now supports receiving environment
1698 variables that are to be set or unset from GDB. These variables
1699 will affect the environment to be passed to the inferior.
1701 * When catching an Ada exception raised with a message, GDB now prints
1702 the message in the catchpoint hit notification. In GDB/MI mode, that
1703 information is provided as an extra field named "exception-message"
1704 in the *stopped notification.
1706 * Trait objects can now be inspected When debugging Rust code. This
1707 requires compiler support which will appear in Rust 1.24.
1709 * New remote packets
1711 QEnvironmentHexEncoded
1712 Inform GDBserver of an environment variable that is to be passed to
1713 the inferior when starting it.
1716 Inform GDBserver of an environment variable that is to be unset
1717 before starting the remote inferior.
1720 Inform GDBserver that the environment should be reset (i.e.,
1721 user-set environment variables should be unset).
1724 Indicates whether the inferior must be started with a shell or not.
1727 Tell GDBserver that the inferior to be started should use a specific
1730 * The "maintenance print c-tdesc" command now takes an optional
1731 argument which is the file name of XML target description.
1733 * The "maintenance selftest" command now takes an optional argument to
1734 filter the tests to be run.
1736 * The "enable", and "disable" commands now accept a range of
1737 breakpoint locations, e.g. "enable 1.3-5".
1742 Set and show the current working directory for the inferior.
1744 set|show compile-gcc
1745 Set and show compilation command used for compiling and injecting code
1746 with the 'compile' commands.
1748 set debug separate-debug-file
1749 show debug separate-debug-file
1750 Control the display of debug output about separate debug file search.
1752 set dump-excluded-mappings
1753 show dump-excluded-mappings
1754 Control whether mappings marked with the VM_DONTDUMP flag should be
1755 dumped when generating a core file.
1757 maint info selftests
1758 List the registered selftests.
1761 Start the debugged program stopping at the first instruction.
1764 Control display of debugging messages related to OpenRISC targets.
1766 set|show print type nested-type-limit
1767 Set and show the limit of nesting level for nested types that the
1768 type printer will show.
1770 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1773 * Safer/improved support for debugging with no debug info
1775 GDB no longer assumes functions with no debug information return
1778 This means that GDB now refuses to call such functions unless you
1779 tell it the function's type, by either casting the call to the
1780 declared return type, or by casting the function to a function
1781 pointer of the right type, and calling that:
1783 (gdb) p getenv ("PATH")
1784 'getenv' has unknown return type; cast the call to its declared return type
1785 (gdb) p (char *) getenv ("PATH")
1786 $1 = 0x7fffffffe "/usr/local/bin:/"...
1787 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1788 $2 = 0x7fffffffe "/usr/local/bin:/"...
1790 Similarly, GDB no longer assumes that global variables with no debug
1791 info have type 'int', and refuses to print the variable's value
1792 unless you tell it the variable's type:
1795 'var' has unknown type; cast it to its declared type
1799 * New native configurations
1801 FreeBSD/aarch64 aarch64*-*-freebsd*
1802 FreeBSD/arm arm*-*-freebsd*
1806 FreeBSD/aarch64 aarch64*-*-freebsd*
1807 FreeBSD/arm arm*-*-freebsd*
1808 OpenRISC ELF or1k*-*-elf
1810 * Removed targets and native configurations
1812 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1814 *** Changes in GDB 8.0
1816 * GDB now supports access to the PKU register on GNU/Linux. The register is
1817 added by the Memory Protection Keys for Userspace feature which will be
1818 available in future Intel CPUs.
1820 * GDB now supports C++11 rvalue references.
1824 ** New functions to start, stop and access a running btrace recording.
1825 ** Rvalue references are now supported in gdb.Type.
1827 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1830 * Building GDB and GDBserver now requires a C++11 compiler.
1832 For example, GCC 4.8 or later.
1834 It is no longer possible to build GDB or GDBserver with a C
1835 compiler. The --disable-build-with-cxx configure option has been
1838 * Building GDB and GDBserver now requires GNU make >= 3.81.
1840 It is no longer supported to build GDB or GDBserver with another
1841 implementation of the make program or an earlier version of GNU make.
1843 * Native debugging on MS-Windows supports command-line redirection
1845 Command-line arguments used for starting programs on MS-Windows can
1846 now include redirection symbols supported by native Windows shells,
1847 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1848 as "run", "start", and "set args", as well as the corresponding MI
1851 * Support for thread names on MS-Windows.
1853 GDB now catches and handles the special exception that programs
1854 running on MS-Windows use to assign names to threads in the
1857 * Support for Java programs compiled with gcj has been removed.
1859 * User commands now accept an unlimited number of arguments.
1860 Previously, only up to 10 was accepted.
1862 * The "eval" command now expands user-defined command arguments.
1864 This makes it easier to process a variable number of arguments:
1869 eval "print $arg%d", $i
1874 * Target descriptions can now describe registers for sparc32 and sparc64.
1876 * GDB now supports DWARF version 5 (debug information format).
1877 Its .debug_names index is not yet supported.
1879 * New native configurations
1881 FreeBSD/mips mips*-*-freebsd
1885 Synopsys ARC arc*-*-elf32
1886 FreeBSD/mips mips*-*-freebsd
1888 * Removed targets and native configurations
1890 Alpha running FreeBSD alpha*-*-freebsd*
1891 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1896 Erases all the flash memory regions reported by the target.
1898 maint print arc arc-instruction address
1899 Print internal disassembler information about instruction at a given address.
1903 set disassembler-options
1904 show disassembler-options
1905 Controls the passing of target specific information to the disassembler.
1906 If it is necessary to specify more than one disassembler option then
1907 multiple options can be placed together into a comma separated list.
1908 The default value is the empty string. Currently, the only supported
1909 targets are ARM, PowerPC and S/390.
1914 Erases all the flash memory regions reported by the target. This is
1915 equivalent to the CLI command flash-erase.
1917 -file-list-shared-libraries
1918 List the shared libraries in the program. This is
1919 equivalent to the CLI command "info shared".
1922 Catchpoints stopping the program when Ada exceptions are
1923 handled. This is equivalent to the CLI command "catch handlers".
1925 *** Changes in GDB 7.12
1927 * GDB and GDBserver now build with a C++ compiler by default.
1929 The --enable-build-with-cxx configure option is now enabled by
1930 default. One must now explicitly configure with
1931 --disable-build-with-cxx in order to build with a C compiler. This
1932 option will be removed in a future release.
1934 * GDBserver now supports recording btrace without maintaining an active
1937 * GDB now supports a negative repeat count in the 'x' command to examine
1938 memory backward from the given address. For example:
1941 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1942 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1943 (gdb) x/-5i 0x0000000000400580
1944 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1945 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1946 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1947 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1948 0x40057b <main(int, char**)+25>:
1949 callq 0x400536 <Func1(int, char const*)>
1951 * Fortran: Support structures with fields of dynamic types and
1952 arrays of dynamic types.
1954 * The symbol dumping maintenance commands have new syntax.
1955 maint print symbols [-pc address] [--] [filename]
1956 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1957 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1958 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1959 maint print msymbols [-objfile objfile] [--] [filename]
1961 * GDB now supports multibit bitfields and enums in target register
1964 * New Python-based convenience function $_as_string(val), which returns
1965 the textual representation of a value. This function is especially
1966 useful to obtain the text label of an enum value.
1968 * Intel MPX bound violation handling.
1970 Segmentation faults caused by a Intel MPX boundary violation
1971 now display the kind of violation (upper or lower), the memory
1972 address accessed and the memory bounds, along with the usual
1973 signal received and code location.
1977 Program received signal SIGSEGV, Segmentation fault
1978 Upper bound violation while accessing address 0x7fffffffc3b3
1979 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1980 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1982 * Rust language support.
1983 GDB now supports debugging programs written in the Rust programming
1984 language. See https://www.rust-lang.org/ for more information about
1987 * Support for running interpreters on specified input/output devices
1989 GDB now supports a new mechanism that allows frontends to provide
1990 fully featured GDB console views, as a better alternative to
1991 building such views on top of the "-interpreter-exec console"
1992 command. See the new "new-ui" command below. With that command,
1993 frontends can now start GDB in the traditional command-line mode
1994 running in an embedded terminal emulator widget, and create a
1995 separate MI interpreter running on a specified i/o device. In this
1996 way, GDB handles line editing, history, tab completion, etc. in the
1997 console all by itself, and the GUI uses the separate MI interpreter
1998 for its own control and synchronization, invisible to the command
2001 * The "catch syscall" command catches groups of related syscalls.
2003 The "catch syscall" command now supports catching a group of related
2004 syscalls using the 'group:' or 'g:' prefix.
2009 skip -gfile file-glob-pattern
2010 skip -function function
2011 skip -rfunction regular-expression
2012 A generalized form of the skip command, with new support for
2013 glob-style file names and regular expressions for function names.
2014 Additionally, a file spec and a function spec may now be combined.
2016 maint info line-table REGEXP
2017 Display the contents of GDB's internal line table data structure.
2020 Run any GDB unit tests that were compiled in.
2023 Start a new user interface instance running INTERP as interpreter,
2024 using the TTY file for input/output.
2028 ** gdb.Breakpoint objects have a new attribute "pending", which
2029 indicates whether the breakpoint is pending.
2030 ** Three new breakpoint-related events have been added:
2031 gdb.breakpoint_created, gdb.breakpoint_modified, and
2032 gdb.breakpoint_deleted.
2034 signal-event EVENTID
2035 Signal ("set") the given MS-Windows event object. This is used in
2036 conjunction with the Windows JIT debugging (AeDebug) support, where
2037 the OS suspends a crashing process until a debugger can attach to
2038 it. Resuming the crashing process, in order to debug it, is done by
2039 signalling an event.
2041 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2042 was added in GDBserver, including JIT compiling fast tracepoint's
2043 conditional expression bytecode into native code.
2045 * Support for various remote target protocols and ROM monitors has
2048 target m32rsdi Remote M32R debugging over SDI
2049 target mips MIPS remote debugging protocol
2050 target pmon PMON ROM monitor
2051 target ddb NEC's DDB variant of PMON for Vr4300
2052 target rockhopper NEC RockHopper variant of PMON
2053 target lsi LSI variant of PMO
2055 * Support for tracepoints and fast tracepoints on powerpc-linux,
2056 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2057 including JIT compiling fast tracepoint's conditional expression
2058 bytecode into native code.
2060 * MI async record =record-started now includes the method and format used for
2061 recording. For example:
2063 =record-started,thread-group="i1",method="btrace",format="bts"
2065 * MI async record =thread-selected now includes the frame field. For example:
2067 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2071 Andes NDS32 nds32*-*-elf
2073 *** Changes in GDB 7.11
2075 * GDB now supports debugging kernel-based threads on FreeBSD.
2077 * Per-inferior thread numbers
2079 Thread numbers are now per inferior instead of global. If you're
2080 debugging multiple inferiors, GDB displays thread IDs using a
2081 qualified INF_NUM.THR_NUM form. For example:
2085 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2086 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2087 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2088 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2090 As consequence, thread numbers as visible in the $_thread
2091 convenience variable and in Python's InferiorThread.num attribute
2092 are no longer unique between inferiors.
2094 GDB now maintains a second thread ID per thread, referred to as the
2095 global thread ID, which is the new equivalent of thread numbers in
2096 previous releases. See also $_gthread below.
2098 For backwards compatibility, MI's thread IDs always refer to global
2101 * Commands that accept thread IDs now accept the qualified
2102 INF_NUM.THR_NUM form as well. For example:
2105 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2108 * In commands that accept a list of thread IDs, you can now refer to
2109 all threads of an inferior using a star wildcard. GDB accepts
2110 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2111 refer to all threads of the current inferior. For example, "info
2114 * You can use "info threads -gid" to display the global thread ID of
2117 * The new convenience variable $_gthread holds the global number of
2120 * The new convenience variable $_inferior holds the number of the
2123 * GDB now displays the ID and name of the thread that hit a breakpoint
2124 or received a signal, if your program is multi-threaded. For
2127 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2128 Thread 1 "main" received signal SIGINT, Interrupt.
2130 * Record btrace now supports non-stop mode.
2132 * Support for tracepoints on aarch64-linux was added in GDBserver.
2134 * The 'record instruction-history' command now indicates speculative execution
2135 when using the Intel Processor Trace recording format.
2137 * GDB now allows users to specify explicit locations, bypassing
2138 the linespec parser. This feature is also available to GDB/MI
2141 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2142 GDB now is able to debug both AArch64 applications and ARM applications
2145 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2146 including JIT compiling fast tracepoint's conditional expression bytecode
2149 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2151 * "info threads", "info inferiors", "info display", "info checkpoints"
2152 and "maint info program-spaces" now list the corresponding items in
2153 ascending ID order, for consistency with all other "info" commands.
2155 * In Ada, the overloads selection menu has been enhanced to display the
2156 parameter types and the return types for the matching overloaded subprograms.
2160 maint set target-non-stop (on|off|auto)
2161 maint show target-non-stop
2162 Control whether GDB targets always operate in non-stop mode even if
2163 "set non-stop" is "off". The default is "auto", meaning non-stop
2164 mode is enabled if supported by the target.
2166 maint set bfd-sharing
2167 maint show bfd-sharing
2168 Control the reuse of bfd objects.
2171 show debug bfd-cache
2172 Control display of debugging info regarding bfd caching.
2176 Control display of debugging info regarding FreeBSD threads.
2178 set remote multiprocess-extensions-packet
2179 show remote multiprocess-extensions-packet
2180 Set/show the use of the remote protocol multiprocess extensions.
2182 set remote thread-events
2183 show remote thread-events
2184 Set/show the use of thread create/exit events.
2186 set ada print-signatures on|off
2187 show ada print-signatures"
2188 Control whether parameter types and return types are displayed in overloads
2189 selection menus. It is activated (@code{on}) by default.
2193 Controls the maximum size of memory, in bytes, that GDB will
2194 allocate for value contents. Prevents incorrect programs from
2195 causing GDB to allocate overly large buffers. Default is 64k.
2197 * The "disassemble" command accepts a new modifier: /s.
2198 It prints mixed source+disassembly like /m with two differences:
2199 - disassembled instructions are now printed in program order, and
2200 - and source for all relevant files is now printed.
2201 The "/m" option is now considered deprecated: its "source-centric"
2202 output hasn't proved useful in practice.
2204 * The "record instruction-history" command accepts a new modifier: /s.
2205 It behaves exactly like /m and prints mixed source+disassembly.
2207 * The "set scheduler-locking" command supports a new mode "replay".
2208 It behaves like "off" in record mode and like "on" in replay mode.
2210 * Support for various ROM monitors has been removed:
2212 target dbug dBUG ROM monitor for Motorola ColdFire
2213 target picobug Motorola picobug monitor
2214 target dink32 DINK32 ROM monitor for PowerPC
2215 target m32r Renesas M32R/D ROM monitor
2216 target mon2000 mon2000 ROM monitor
2217 target ppcbug PPCBUG ROM monitor for PowerPC
2219 * Support for reading/writing memory and extracting values on architectures
2220 whose memory is addressable in units of any integral multiple of 8 bits.
2223 Allows to break when an Ada exception is handled.
2225 * New remote packets
2228 Indicates that an exec system call was executed.
2230 exec-events feature in qSupported
2231 The qSupported packet allows GDB to request support for exec
2232 events using the new 'gdbfeature' exec-event, and the qSupported
2233 response can contain the corresponding 'stubfeature'. Set and
2234 show commands can be used to display whether these features are enabled.
2237 Equivalent to interrupting with the ^C character, but works in
2240 thread created stop reason (T05 create:...)
2241 Indicates that the thread was just created and is stopped at entry.
2243 thread exit stop reply (w exitcode;tid)
2244 Indicates that the thread has terminated.
2247 Enables/disables thread create and exit event reporting. For
2248 example, this is used in non-stop mode when GDB stops a set of
2249 threads and synchronously waits for the their corresponding stop
2250 replies. Without exit events, if one of the threads exits, GDB
2251 would hang forever not knowing that it should no longer expect a
2252 stop for that same thread.
2255 Indicates that there are no resumed threads left in the target (all
2256 threads are stopped). The remote stub reports support for this stop
2257 reply to GDB's qSupported query.
2260 Enables/disables catching syscalls from the inferior process.
2261 The remote stub reports support for this packet to GDB's qSupported query.
2263 syscall_entry stop reason
2264 Indicates that a syscall was just called.
2266 syscall_return stop reason
2267 Indicates that a syscall just returned.
2269 * Extended-remote exec events
2271 ** GDB now has support for exec events on extended-remote Linux targets.
2272 For such targets with Linux kernels 2.5.46 and later, this enables
2273 follow-exec-mode and exec catchpoints.
2275 set remote exec-event-feature-packet
2276 show remote exec-event-feature-packet
2277 Set/show the use of the remote exec event feature.
2279 * Thread names in remote protocol
2281 The reply to qXfer:threads:read may now include a name attribute for each
2284 * Target remote mode fork and exec events
2286 ** GDB now has support for fork and exec events on target remote mode
2287 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2288 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2289 fork and exec catchpoints.
2291 * Remote syscall events
2293 ** GDB now has support for catch syscall on remote Linux targets,
2294 currently enabled on x86/x86_64 architectures.
2296 set remote catch-syscall-packet
2297 show remote catch-syscall-packet
2298 Set/show the use of the remote catch syscall feature.
2302 ** The -var-set-format command now accepts the zero-hexadecimal
2303 format. It outputs data in hexadecimal format with zero-padding on the
2308 ** gdb.InferiorThread objects have a new attribute "global_num",
2309 which refers to the thread's global thread ID. The existing
2310 "num" attribute now refers to the thread's per-inferior number.
2311 See "Per-inferior thread numbers" above.
2312 ** gdb.InferiorThread objects have a new attribute "inferior", which
2313 is the Inferior object the thread belongs to.
2315 *** Changes in GDB 7.10
2317 * Support for process record-replay and reverse debugging on aarch64*-linux*
2318 targets has been added. GDB now supports recording of A64 instruction set
2319 including advance SIMD instructions.
2321 * Support for Sun's version of the "stabs" debug file format has been removed.
2323 * GDB now honors the content of the file /proc/PID/coredump_filter
2324 (PID is the process ID) on GNU/Linux systems. This file can be used
2325 to specify the types of memory mappings that will be included in a
2326 corefile. For more information, please refer to the manual page of
2327 "core(5)". GDB also has a new command: "set use-coredump-filter
2328 on|off". It allows to set whether GDB will read the content of the
2329 /proc/PID/coredump_filter file when generating a corefile.
2331 * The "info os" command on GNU/Linux can now display information on
2333 "info os cpus" Listing of all cpus/cores on the system
2335 * GDB has two new commands: "set serial parity odd|even|none" and
2336 "show serial parity". These allows to set or show parity for the
2339 * The "info source" command now displays the producer string if it was
2340 present in the debug info. This typically includes the compiler version
2341 and may include things like its command line arguments.
2343 * The "info dll", an alias of the "info sharedlibrary" command,
2344 is now available on all platforms.
2346 * Directory names supplied to the "set sysroot" commands may be
2347 prefixed with "target:" to tell GDB to access shared libraries from
2348 the target system, be it local or remote. This replaces the prefix
2349 "remote:". The default sysroot has been changed from "" to
2350 "target:". "remote:" is automatically converted to "target:" for
2351 backward compatibility.
2353 * The system root specified by "set sysroot" will be prepended to the
2354 filename of the main executable (if reported to GDB as absolute by
2355 the operating system) when starting processes remotely, and when
2356 attaching to already-running local or remote processes.
2358 * GDB now supports automatic location and retrieval of executable
2359 files from remote targets. Remote debugging can now be initiated
2360 using only a "target remote" or "target extended-remote" command
2361 (no "set sysroot" or "file" commands are required). See "New remote
2364 * The "dump" command now supports verilog hex format.
2366 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2368 * On GNU/Linux, GDB and gdbserver are now able to access executable
2369 and shared library files without a "set sysroot" command when
2370 attaching to processes running in different mount namespaces from
2371 the debugger. This makes it possible to attach to processes in
2372 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2373 See "New remote packets" below.
2375 * The "tui reg" command now provides completion for all of the
2376 available register groups, including target specific groups.
2378 * The HISTSIZE environment variable is no longer read when determining
2379 the size of GDB's command history. GDB now instead reads the dedicated
2380 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2381 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2386 ** Memory ports can now be unbuffered.
2390 ** gdb.Objfile objects have a new attribute "username",
2391 which is the name of the objfile as specified by the user,
2392 without, for example, resolving symlinks.
2393 ** You can now write frame unwinders in Python.
2394 ** gdb.Type objects have a new method "optimized_out",
2395 returning optimized out gdb.Value instance of this type.
2396 ** gdb.Value objects have new methods "reference_value" and
2397 "const_value" which return a reference to the value and a
2398 "const" version of the value respectively.
2402 maint print symbol-cache
2403 Print the contents of the symbol cache.
2405 maint print symbol-cache-statistics
2406 Print statistics of symbol cache usage.
2408 maint flush-symbol-cache
2409 Flush the contents of the symbol cache.
2413 Start branch trace recording using Branch Trace Store (BTS) format.
2416 Evaluate expression by using the compiler and print result.
2420 Explicit commands for enabling and disabling tui mode.
2423 set mpx bound on i386 and amd64
2424 Support for bound table investigation on Intel MPX enabled applications.
2428 Start branch trace recording using Intel Processor Trace format.
2431 Print information about branch tracing internals.
2433 maint btrace packet-history
2434 Print the raw branch tracing data.
2436 maint btrace clear-packet-history
2437 Discard the stored raw branch tracing data.
2440 Discard all branch tracing data. It will be fetched and processed
2441 anew by the next "record" command.
2446 Renamed from "set debug dwarf2-die".
2447 show debug dwarf-die
2448 Renamed from "show debug dwarf2-die".
2450 set debug dwarf-read
2451 Renamed from "set debug dwarf2-read".
2452 show debug dwarf-read
2453 Renamed from "show debug dwarf2-read".
2455 maint set dwarf always-disassemble
2456 Renamed from "maint set dwarf2 always-disassemble".
2457 maint show dwarf always-disassemble
2458 Renamed from "maint show dwarf2 always-disassemble".
2460 maint set dwarf max-cache-age
2461 Renamed from "maint set dwarf2 max-cache-age".
2462 maint show dwarf max-cache-age
2463 Renamed from "maint show dwarf2 max-cache-age".
2465 set debug dwarf-line
2466 show debug dwarf-line
2467 Control display of debugging info regarding DWARF line processing.
2470 show max-completions
2471 Set the maximum number of candidates to be considered during
2472 completion. The default value is 200. This limit allows GDB
2473 to avoid generating large completion lists, the computation of
2474 which can cause the debugger to become temporarily unresponsive.
2476 set history remove-duplicates
2477 show history remove-duplicates
2478 Control the removal of duplicate history entries.
2480 maint set symbol-cache-size
2481 maint show symbol-cache-size
2482 Control the size of the symbol cache.
2484 set|show record btrace bts buffer-size
2485 Set and show the size of the ring buffer used for branch tracing in
2487 The obtained size may differ from the requested size. Use "info
2488 record" to see the obtained buffer size.
2490 set debug linux-namespaces
2491 show debug linux-namespaces
2492 Control display of debugging info regarding Linux namespaces.
2494 set|show record btrace pt buffer-size
2495 Set and show the size of the ring buffer used for branch tracing in
2496 Intel Processor Trace format.
2497 The obtained size may differ from the requested size. Use "info
2498 record" to see the obtained buffer size.
2500 maint set|show btrace pt skip-pad
2501 Set and show whether PAD packets are skipped when computing the
2504 * The command 'thread apply all' can now support new option '-ascending'
2505 to call its specified command for all threads in ascending order.
2507 * Python/Guile scripting
2509 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2510 special section named `.debug_gdb_scripts'.
2512 * New remote packets
2514 qXfer:btrace-conf:read
2515 Return the branch trace configuration for the current thread.
2517 Qbtrace-conf:bts:size
2518 Set the requested ring buffer size for branch tracing in BTS format.
2521 Enable Intel Processor Trace-based branch tracing for the current
2522 process. The remote stub reports support for this packet to GDB's
2525 Qbtrace-conf:pt:size
2526 Set the requested ring buffer size for branch tracing in Intel Processor
2530 Indicates a memory breakpoint instruction was executed, irrespective
2531 of whether it was GDB that planted the breakpoint or the breakpoint
2532 is hardcoded in the program. This is required for correct non-stop
2536 Indicates the target stopped for a hardware breakpoint. This is
2537 required for correct non-stop mode operation.
2540 Return information about files on the remote system.
2542 qXfer:exec-file:read
2543 Return the full absolute name of the file that was executed to
2544 create a process running on the remote system.
2547 Select the filesystem on which vFile: operations with filename
2548 arguments will operate. This is required for GDB to be able to
2549 access files on remote targets where the remote stub does not
2550 share a common filesystem with the inferior(s).
2553 Indicates that a fork system call was executed.
2556 Indicates that a vfork system call was executed.
2558 vforkdone stop reason
2559 Indicates that a vfork child of the specified process has executed
2560 an exec or exit, allowing the vfork parent to resume execution.
2562 fork-events and vfork-events features in qSupported
2563 The qSupported packet allows GDB to request support for fork and
2564 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2565 and the qSupported response can contain the corresponding
2566 'stubfeatures'. Set and show commands can be used to display
2567 whether these features are enabled.
2569 * Extended-remote fork events
2571 ** GDB now has support for fork events on extended-remote Linux
2572 targets. For targets with Linux kernels 2.5.60 and later, this
2573 enables follow-fork-mode and detach-on-fork for both fork and
2574 vfork, as well as fork and vfork catchpoints.
2576 * The info record command now shows the recording format and the
2577 branch tracing configuration for the current thread when using
2578 the btrace record target.
2579 For the BTS format, it shows the ring buffer size.
2581 * GDB now has support for DTrace USDT (Userland Static Defined
2582 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2584 * GDB now supports access to vector registers on S/390 GNU/Linux
2587 * Removed command line options
2589 -xdb HP-UX XDB compatibility mode.
2591 * Removed targets and native configurations
2593 HP/PA running HP-UX hppa*-*-hpux*
2594 Itanium running HP-UX ia64-*-hpux*
2596 * New configure options
2599 This configure option allows the user to build GDB with support for
2600 Intel Processor Trace (default: auto). This requires libipt.
2602 --with-libipt-prefix=PATH
2603 Specify the path to the version of libipt that GDB should use.
2604 $PATH/include should contain the intel-pt.h header and
2605 $PATH/lib should contain the libipt.so library.
2607 *** Changes in GDB 7.9.1
2611 ** Xmethods can now specify a result type.
2613 *** Changes in GDB 7.9
2615 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2619 ** You can now access frame registers from Python scripts.
2620 ** New attribute 'producer' for gdb.Symtab objects.
2621 ** gdb.Objfile objects have a new attribute "progspace",
2622 which is the gdb.Progspace object of the containing program space.
2623 ** gdb.Objfile objects have a new attribute "owner".
2624 ** gdb.Objfile objects have a new attribute "build_id",
2625 which is the build ID generated when the file was built.
2626 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2627 ** A new event "gdb.clear_objfiles" has been added, triggered when
2628 selecting a new file to debug.
2629 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2630 ** New function gdb.lookup_objfile.
2632 New events which are triggered when GDB modifies the state of the
2635 ** gdb.events.inferior_call_pre: Function call is about to be made.
2636 ** gdb.events.inferior_call_post: Function call has just been made.
2637 ** gdb.events.memory_changed: A memory location has been altered.
2638 ** gdb.events.register_changed: A register has been altered.
2640 * New Python-based convenience functions:
2642 ** $_caller_is(name [, number_of_frames])
2643 ** $_caller_matches(regexp [, number_of_frames])
2644 ** $_any_caller_is(name [, number_of_frames])
2645 ** $_any_caller_matches(regexp [, number_of_frames])
2647 * GDB now supports the compilation and injection of source code into
2648 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2649 to compile the source code to object code, and if successful, inject
2650 and execute that code within the current context of the inferior.
2651 Currently the C language is supported. The commands used to
2652 interface with this new feature are:
2654 compile code [-raw|-r] [--] [source code]
2655 compile file [-raw|-r] filename
2659 demangle [-l language] [--] name
2660 Demangle "name" in the specified language, or the current language
2661 if elided. This command is renamed from the "maint demangle" command.
2662 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2663 as "maint demangler-warning".
2665 queue-signal signal-name-or-number
2666 Queue a signal to be delivered to the thread when it is resumed.
2668 add-auto-load-scripts-directory directory
2669 Add entries to the list of directories from which to load auto-loaded
2672 maint print user-registers
2673 List all currently available "user" registers.
2675 compile code [-r|-raw] [--] [source code]
2676 Compile, inject, and execute in the inferior the executable object
2677 code produced by compiling the provided source code.
2679 compile file [-r|-raw] filename
2680 Compile and inject into the inferior the executable object code
2681 produced by compiling the source code stored in the filename
2684 * On resume, GDB now always passes the signal the program had stopped
2685 for to the thread the signal was sent to, even if the user changed
2686 threads before resuming. Previously GDB would often (but not
2687 always) deliver the signal to the thread that happens to be current
2690 * Conversely, the "signal" command now consistently delivers the
2691 requested signal to the current thread. GDB now asks for
2692 confirmation if the program had stopped for a signal and the user
2693 switched threads meanwhile.
2695 * "breakpoint always-inserted" modes "off" and "auto" merged.
2697 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2698 won't remove breakpoints from the target until all threads stop,
2699 even in non-stop mode. The "auto" mode has been removed, and "off"
2700 is now the default mode.
2704 set debug symbol-lookup
2705 show debug symbol-lookup
2706 Control display of debugging info regarding symbol lookup.
2710 ** The -list-thread-groups command outputs an exit-code field for
2711 inferiors that have exited.
2715 MIPS SDE mips*-sde*-elf*
2719 Support for these obsolete configurations has been removed.
2721 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2722 SGI Irix-5.x mips-*-irix5*
2723 SGI Irix-6.x mips-*-irix6*
2724 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2725 VAX running Ultrix vax-*-ultrix*
2727 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2728 and "assf"), have been removed. Use the "sharedlibrary" command, or
2729 its alias "share", instead.
2731 *** Changes in GDB 7.8
2733 * New command line options
2736 This is an alias for the --data-directory option.
2738 * GDB supports printing and modifying of variable length automatic arrays
2739 as specified in ISO C99.
2741 * The ARM simulator now supports instruction level tracing
2742 with or without disassembly.
2746 GDB now has support for scripting using Guile. Whether this is
2747 available is determined at configure time.
2748 Guile version 2.0 or greater is required.
2749 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2751 * New commands (for set/show, see "New options" below)
2755 Invoke CODE by passing it to the Guile interpreter.
2759 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2761 info auto-load guile-scripts [regexp]
2762 Print the list of automatically loaded Guile scripts.
2764 * The source command is now capable of sourcing Guile scripts.
2765 This feature is dependent on the debugger being built with Guile support.
2769 set print symbol-loading (off|brief|full)
2770 show print symbol-loading
2771 Control whether to print informational messages when loading symbol
2772 information for a file. The default is "full", but when debugging
2773 programs with large numbers of shared libraries the amount of output
2774 becomes less useful.
2776 set guile print-stack (none|message|full)
2777 show guile print-stack
2778 Show a stack trace when an error is encountered in a Guile script.
2780 set auto-load guile-scripts (on|off)
2781 show auto-load guile-scripts
2782 Control auto-loading of Guile script files.
2784 maint ada set ignore-descriptive-types (on|off)
2785 maint ada show ignore-descriptive-types
2786 Control whether the debugger should ignore descriptive types in Ada
2787 programs. The default is not to ignore the descriptive types. See
2788 the user manual for more details on descriptive types and the intended
2789 usage of this option.
2791 set auto-connect-native-target
2793 Control whether GDB is allowed to automatically connect to the
2794 native target for the run, attach, etc. commands when not connected
2795 to any target yet. See also "target native" below.
2797 set record btrace replay-memory-access (read-only|read-write)
2798 show record btrace replay-memory-access
2799 Control what memory accesses are allowed during replay.
2801 maint set target-async (on|off)
2802 maint show target-async
2803 This controls whether GDB targets operate in synchronous or
2804 asynchronous mode. Normally the default is asynchronous, if it is
2805 available; but this can be changed to more easily debug problems
2806 occurring only in synchronous mode.
2808 set mi-async (on|off)
2810 Control whether MI asynchronous mode is preferred. This supersedes
2811 "set target-async" of previous GDB versions.
2813 * "set target-async" is deprecated as a CLI option and is now an alias
2814 for "set mi-async" (only puts MI into async mode).
2816 * Background execution commands (e.g., "c&", "s&", etc.) are now
2817 possible ``out of the box'' if the target supports them. Previously
2818 the user would need to explicitly enable the possibility with the
2819 "set target-async on" command.
2821 * New features in the GDB remote stub, GDBserver
2823 ** New option --debug-format=option1[,option2,...] allows one to add
2824 additional text to each output. At present only timestamps
2825 are supported: --debug-format=timestamps.
2826 Timestamps can also be turned on with the
2827 "monitor set debug-format timestamps" command from GDB.
2829 * The 'record instruction-history' command now starts counting instructions
2830 at one. This also affects the instruction ranges reported by the
2831 'record function-call-history' command when given the /i modifier.
2833 * The command 'record function-call-history' supports a new modifier '/c' to
2834 indent the function names based on their call stack depth.
2835 The fields for the '/i' and '/l' modifier have been reordered.
2836 The source line range is now prefixed with 'at'.
2837 The instruction range is now prefixed with 'inst'.
2838 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2839 "record instruction-history" and "list" commands.
2841 * The ranges given as arguments to the 'record function-call-history' and
2842 'record instruction-history' commands are now inclusive.
2844 * The btrace record target now supports the 'record goto' command.
2845 For locations inside the execution trace, the back trace is computed
2846 based on the information stored in the execution trace.
2848 * The btrace record target supports limited reverse execution and replay.
2849 The target does not record data and therefore does not allow reading
2850 memory or registers.
2852 * The "catch syscall" command now works on s390*-linux* targets.
2854 * The "compare-sections" command is no longer specific to target
2855 remote. It now works with all targets.
2857 * All native targets are now consistently called "native".
2858 Consequently, the "target child", "target GNU", "target djgpp",
2859 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2860 commands have been replaced with "target native". The QNX/NTO port
2861 leaves the "procfs" target in place and adds a "native" target for
2862 consistency with other ports. The impact on users should be minimal
2863 as these commands previously either throwed an error, or were
2864 no-ops. The target's name is visible in the output of the following
2865 commands: "help target", "info target", "info files", "maint print
2868 * The "target native" command now connects to the native target. This
2869 can be used to launch native programs even when "set
2870 auto-connect-native-target" is set to off.
2872 * GDB now supports access to Intel MPX registers on GNU/Linux.
2874 * Support for Intel AVX-512 registers on GNU/Linux.
2875 Support displaying and modifying Intel AVX-512 registers
2876 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2878 * New remote packets
2880 qXfer:btrace:read's annex
2881 The qXfer:btrace:read packet supports a new annex 'delta' to read
2882 branch trace incrementally.
2886 ** Valid Python operations on gdb.Value objects representing
2887 structs/classes invoke the corresponding overloaded operators if
2889 ** New `Xmethods' feature in the Python API. Xmethods are
2890 additional methods or replacements for existing methods of a C++
2891 class. This feature is useful for those cases where a method
2892 defined in C++ source code could be inlined or optimized out by
2893 the compiler, making it unavailable to GDB.
2896 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2898 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2899 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2900 its alias "share", instead.
2902 * The commands "set remotebaud" and "show remotebaud" are no longer
2903 supported. Use "set serial baud" and "show serial baud" (respectively)
2908 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2909 target-async". The latter is left as a deprecated alias of the
2910 former for backward compatibility. If the target supports it,
2911 CLI background execution commands are now always possible by
2912 default, independently of whether the frontend stated a
2913 preference for asynchronous execution with "-gdb-set mi-async".
2914 Previously "-gdb-set target-async off" affected both MI execution
2915 commands and CLI execution commands.
2917 *** Changes in GDB 7.7
2919 * Improved support for process record-replay and reverse debugging on
2920 arm*-linux* targets. Support for thumb32 and syscall instruction
2921 recording has been added.
2923 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2925 * GDB now supports Fission DWP file format version 2.
2926 http://gcc.gnu.org/wiki/DebugFission
2928 * New convenience function "$_isvoid", to check whether an expression
2929 is void. A void expression is an expression where the type of the
2930 result is "void". For example, some convenience variables may be
2931 "void" when evaluated (e.g., "$_exitcode" before the execution of
2932 the program being debugged; or an undefined convenience variable).
2933 Another example, when calling a function whose return type is
2936 * The "maintenance print objfiles" command now takes an optional regexp.
2938 * The "catch syscall" command now works on arm*-linux* targets.
2940 * GDB now consistently shows "<not saved>" when printing values of
2941 registers the debug info indicates have not been saved in the frame
2942 and there's nowhere to retrieve them from
2943 (callee-saved/call-clobbered registers):
2948 (gdb) info registers rax
2951 Before, the former would print "<optimized out>", and the latter
2952 "*value not available*".
2954 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2959 ** Frame filters and frame decorators have been added.
2960 ** Temporary breakpoints are now supported.
2961 ** Line tables representation has been added.
2962 ** New attribute 'parent_type' for gdb.Field objects.
2963 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2964 ** New attribute 'name' for gdb.Type objects.
2968 Nios II ELF nios2*-*-elf
2969 Nios II GNU/Linux nios2*-*-linux
2970 Texas Instruments MSP430 msp430*-*-elf
2972 * Removed native configurations
2974 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2975 been removed. ELF variants of these configurations are kept supported.
2977 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2978 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2979 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2980 i[34567]86-*-openbsd3.[0-3]
2981 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2982 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2983 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2987 Like "catch throw", but catches a re-thrown exception.
2988 maint check-psymtabs
2989 Renamed from old "maint check-symtabs".
2991 Perform consistency checks on symtabs.
2992 maint expand-symtabs
2993 Expand symtabs matching an optional regexp.
2996 Display the details of GDB configure-time options.
2998 maint set|show per-command
2999 maint set|show per-command space
3000 maint set|show per-command time
3001 maint set|show per-command symtab
3002 Enable display of per-command gdb resource usage.
3004 remove-symbol-file FILENAME
3005 remove-symbol-file -a ADDRESS
3006 Remove a symbol file added via add-symbol-file. The file to remove
3007 can be identified by its filename or by an address that lies within
3008 the boundaries of this symbol file in memory.
3011 info exceptions REGEXP
3012 Display the list of Ada exceptions defined in the program being
3013 debugged. If provided, only the exceptions whose names match REGEXP
3018 set debug symfile off|on
3020 Control display of debugging info regarding reading symbol files and
3021 symbol tables within those files
3023 set print raw frame-arguments
3024 show print raw frame-arguments
3025 Set/show whether to print frame arguments in raw mode,
3026 disregarding any defined pretty-printers.
3028 set remote trace-status-packet
3029 show remote trace-status-packet
3030 Set/show the use of remote protocol qTStatus packet.
3034 Control display of debugging messages related to Nios II targets.
3038 Control whether target-assisted range stepping is enabled.
3040 set startup-with-shell
3041 show startup-with-shell
3042 Specifies whether Unix child processes are started via a shell or
3047 Use the target memory cache for accesses to the code segment. This
3048 improves performance of remote debugging (particularly disassembly).
3050 * You can now use a literal value 'unlimited' for options that
3051 interpret 0 or -1 as meaning "unlimited". E.g., "set
3052 trace-buffer-size unlimited" is now an alias for "set
3053 trace-buffer-size -1" and "set height unlimited" is now an alias for
3056 * The "set debug symtab-create" debugging option of GDB has been changed to
3057 accept a verbosity level. 0 means "off", 1 provides basic debugging
3058 output, and values of 2 or greater provides more verbose output.
3060 * New command-line options
3062 Display the details of GDB configure-time options.
3064 * The command 'tsave' can now support new option '-ctf' to save trace
3065 buffer in Common Trace Format.
3067 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3070 * GDB now implements the C++ 'typeid' operator.
3072 * The new convenience variable $_exception holds the exception being
3073 thrown or caught at an exception-related catchpoint.
3075 * The exception-related catchpoints, like "catch throw", now accept a
3076 regular expression which can be used to filter exceptions by type.
3078 * The new convenience variable $_exitsignal is automatically set to
3079 the terminating signal number when the program being debugged dies
3080 due to an uncaught signal.
3084 ** All MI commands now accept an optional "--language" option.
3085 Support for this feature can be verified by using the "-list-features"
3086 command, which should contain "language-option".
3088 ** The new command -info-gdb-mi-command allows the user to determine
3089 whether a GDB/MI command is supported or not.
3091 ** The "^error" result record returned when trying to execute an undefined
3092 GDB/MI command now provides a variable named "code" whose content is the
3093 "undefined-command" error code. Support for this feature can be verified
3094 by using the "-list-features" command, which should contain
3095 "undefined-command-error-code".
3097 ** The -trace-save MI command can optionally save trace buffer in Common
3100 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3102 ** The command -data-list-register-values now accepts an optional
3103 "--skip-unavailable" option. When used, only the available registers
3106 ** The new command -trace-frame-collected dumps collected variables,
3107 computed expressions, tvars, memory and registers in a traceframe.
3109 ** The commands -stack-list-locals, -stack-list-arguments and
3110 -stack-list-variables now accept an option "--skip-unavailable".
3111 When used, only the available locals or arguments are displayed.
3113 ** The -exec-run command now accepts an optional "--start" option.
3114 When used, the command follows the same semantics as the "start"
3115 command, stopping the program's execution at the start of its
3116 main subprogram. Support for this feature can be verified using
3117 the "-list-features" command, which should contain
3118 "exec-run-start-option".
3120 ** The new commands -catch-assert and -catch-exceptions insert
3121 catchpoints stopping the program when Ada exceptions are raised.
3123 ** The new command -info-ada-exceptions provides the equivalent of
3124 the new "info exceptions" command.
3126 * New system-wide configuration scripts
3127 A GDB installation now provides scripts suitable for use as system-wide
3128 configuration scripts for the following systems:
3132 * GDB now supports target-assigned range stepping with remote targets.
3133 This improves the performance of stepping source lines by reducing
3134 the number of control packets from/to GDB. See "New remote packets"
3137 * GDB now understands the element 'tvar' in the XML traceframe info.
3138 It has the id of the collected trace state variables.
3140 * On S/390 targets that provide the transactional-execution feature,
3141 the program interruption transaction diagnostic block (TDB) is now
3142 represented as a number of additional "registers" in GDB.
3144 * New remote packets
3148 The vCont packet supports a new 'r' action, that tells the remote
3149 stub to step through an address range itself, without GDB
3150 involvemement at each single-step.
3152 qXfer:libraries-svr4:read's annex
3153 The previously unused annex of the qXfer:libraries-svr4:read packet
3154 is now used to support passing an argument list. The remote stub
3155 reports support for this argument list to GDB's qSupported query.
3156 The defined arguments are "start" and "prev", used to reduce work
3157 necessary for library list updating, resulting in significant
3160 * New features in the GDB remote stub, GDBserver
3162 ** GDBserver now supports target-assisted range stepping. Currently
3163 enabled on x86/x86_64 GNU/Linux targets.
3165 ** GDBserver now adds element 'tvar' in the XML in the reply to
3166 'qXfer:traceframe-info:read'. It has the id of the collected
3167 trace state variables.
3169 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3172 * New 'z' formatter for printing and examining memory, this displays the
3173 value as hexadecimal zero padded on the left to the size of the type.
3175 * GDB can now use Windows x64 unwinding data.
3177 * The "set remotebaud" command has been replaced by "set serial baud".
3178 Similarly, "show remotebaud" has been replaced by "show serial baud".
3179 The "set remotebaud" and "show remotebaud" commands are still available
3180 to provide backward compatibility with older versions of GDB.
3182 *** Changes in GDB 7.6
3184 * Target record has been renamed to record-full.
3185 Record/replay is now enabled with the "record full" command.
3186 This also affects settings that are associated with full record/replay
3187 that have been moved from "set/show record" to "set/show record full":
3189 set|show record full insn-number-max
3190 set|show record full stop-at-limit
3191 set|show record full memory-query
3193 * A new record target "record-btrace" has been added. The new target
3194 uses hardware support to record the control-flow of a process. It
3195 does not support replaying the execution, but it implements the
3196 below new commands for investigating the recorded execution log.
3197 This new recording method can be enabled using:
3201 The "record-btrace" target is only available on Intel Atom processors
3202 and requires a Linux kernel 2.6.32 or later.
3204 * Two new commands have been added for record/replay to give information
3205 about the recorded execution without having to replay the execution.
3206 The commands are only supported by "record btrace".
3208 record instruction-history prints the execution history at
3209 instruction granularity
3211 record function-call-history prints the execution history at
3212 function granularity
3214 * New native configurations
3216 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3217 FreeBSD/powerpc powerpc*-*-freebsd
3218 x86_64/Cygwin x86_64-*-cygwin*
3219 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3223 ARM AArch64 aarch64*-*-elf
3224 ARM AArch64 GNU/Linux aarch64*-*-linux
3225 Lynx 178 PowerPC powerpc-*-lynx*178
3226 x86_64/Cygwin x86_64-*-cygwin*
3227 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3229 * If the configured location of system.gdbinit file (as given by the
3230 --with-system-gdbinit option at configure time) is in the
3231 data-directory (as specified by --with-gdb-datadir at configure
3232 time) or in one of its subdirectories, then GDB will look for the
3233 system-wide init file in the directory specified by the
3234 --data-directory command-line option.
3236 * New command line options:
3238 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3239 other initialization files, unlike -nx which disables all of them.
3241 * Removed command line options
3243 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3246 * The 'ptype' and 'whatis' commands now accept an argument to control
3249 * 'info proc' now works on some core files.
3253 ** Vectors can be created with gdb.Type.vector.
3255 ** Python's atexit.register now works in GDB.
3257 ** Types can be pretty-printed via a Python API.
3259 ** Python 3 is now supported (in addition to Python 2.4 or later)
3261 ** New class gdb.Architecture exposes GDB's internal representation
3262 of architecture in the Python API.
3264 ** New method Frame.architecture returns the gdb.Architecture object
3265 corresponding to the frame's architecture.
3267 * New Python-based convenience functions:
3269 ** $_memeq(buf1, buf2, length)
3270 ** $_streq(str1, str2)
3272 ** $_regex(str, regex)
3274 * The 'cd' command now defaults to using '~' (the home directory) if not
3277 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3278 default for GCC since November 2000.
3280 * The command 'forward-search' can now be abbreviated as 'fo'.
3282 * The command 'info tracepoints' can now display 'installed on target'
3283 or 'not installed on target' for each non-pending location of tracepoint.
3285 * New configure options
3287 --enable-libmcheck/--disable-libmcheck
3288 By default, development versions are built with -lmcheck on hosts
3289 that support it, in order to help track memory corruption issues.
3290 Release versions, on the other hand, are built without -lmcheck
3291 by default. The --enable-libmcheck/--disable-libmcheck configure
3292 options allow the user to override that default.
3293 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3294 This configure option allows the user to build GDB with
3295 libbabeltrace using which GDB can read Common Trace Format data.
3297 * New commands (for set/show, see "New options" below)
3300 Catch signals. This is similar to "handle", but allows commands and
3301 conditions to be attached.
3304 List the BFDs known to GDB.
3306 python-interactive [command]
3308 Start a Python interactive prompt, or evaluate the optional command
3309 and print the result of expressions.
3312 "py" is a new alias for "python".
3314 enable type-printer [name]...
3315 disable type-printer [name]...
3316 Enable or disable type printers.
3320 ** For the Renesas Super-H architecture, the "regs" command has been removed
3321 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3326 set print type methods (on|off)
3327 show print type methods
3328 Control whether method declarations are displayed by "ptype".
3329 The default is to show them.
3331 set print type typedefs (on|off)
3332 show print type typedefs
3333 Control whether typedef definitions are displayed by "ptype".
3334 The default is to show them.
3336 set filename-display basename|relative|absolute
3337 show filename-display
3338 Control the way in which filenames is displayed.
3339 The default is "relative", which preserves previous behavior.
3341 set trace-buffer-size
3342 show trace-buffer-size
3343 Request target to change the size of trace buffer.
3345 set remote trace-buffer-size-packet auto|on|off
3346 show remote trace-buffer-size-packet
3347 Control the use of the remote protocol `QTBuffer:size' packet.
3351 Control display of debugging messages related to ARM AArch64.
3354 set debug coff-pe-read
3355 show debug coff-pe-read
3356 Control display of debugging messages related to reading of COFF/PE
3361 Control display of debugging messages related to Mach-O symbols
3364 set debug notification
3365 show debug notification
3366 Control display of debugging info for async remote notification.
3370 ** Command parameter changes are now notified using new async record
3371 "=cmd-param-changed".
3372 ** Trace frame changes caused by command "tfind" are now notified using
3373 new async record "=traceframe-changed".
3374 ** The creation, deletion and modification of trace state variables
3375 are now notified using new async records "=tsv-created",
3376 "=tsv-deleted" and "=tsv-modified".
3377 ** The start and stop of process record are now notified using new
3378 async record "=record-started" and "=record-stopped".
3379 ** Memory changes are now notified using new async record
3381 ** The data-disassemble command response will include a "fullname" field
3382 containing the absolute file name when source has been requested.
3383 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3384 command, to allow pattern filling of memory areas.
3385 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3386 library load/unload events.
3387 ** The response to breakpoint commands and breakpoint async records
3388 includes an "installed" field containing a boolean state about each
3389 non-pending tracepoint location is whether installed on target or not.
3390 ** Output of the "-trace-status" command includes a "trace-file" field
3391 containing the name of the trace file being examined. This field is
3392 optional, and only present when examining a trace file.
3393 ** The "fullname" field is now always present along with the "file" field,
3394 even if the file cannot be found by GDB.
3396 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3397 You must have the LZMA library available when configuring GDB for this
3398 feature to be enabled. For more information, see:
3399 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3401 * New remote packets
3404 Set the size of trace buffer. The remote stub reports support for this
3405 packet to gdb's qSupported query.
3408 Enable Branch Trace Store (BTS)-based branch tracing for the current
3409 thread. The remote stub reports support for this packet to gdb's
3413 Disable branch tracing for the current thread. The remote stub reports
3414 support for this packet to gdb's qSupported query.
3417 Read the traced branches for the current thread. The remote stub
3418 reports support for this packet to gdb's qSupported query.
3420 *** Changes in GDB 7.5
3422 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3423 for more x32 ABI info.
3425 * GDB now supports access to MIPS DSP registers on Linux targets.
3427 * GDB now supports debugging microMIPS binaries.
3429 * The "info os" command on GNU/Linux can now display information on
3430 several new classes of objects managed by the operating system:
3431 "info os procgroups" lists process groups
3432 "info os files" lists file descriptors
3433 "info os sockets" lists internet-domain sockets
3434 "info os shm" lists shared-memory regions
3435 "info os semaphores" lists semaphores
3436 "info os msg" lists message queues
3437 "info os modules" lists loaded kernel modules
3439 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3440 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3441 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3442 options and inspect the probe arguments using the new $_probe_arg family
3443 of convenience variables. You can obtain more information about SystemTap
3444 in <http://sourceware.org/systemtap/>.
3446 * GDB now supports reversible debugging on ARM, it allows you to
3447 debug basic ARM and THUMB instructions, and provides
3448 record/replay support.
3450 * The option "symbol-reloading" has been deleted as it is no longer used.
3454 ** GDB commands implemented in Python can now be put in command class
3457 ** The "maint set python print-stack on|off" is now deleted.
3459 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3460 apply "flag enum"-style pretty-printing to any enum.
3462 ** gdb.lookup_symbol can now work when there is no current frame.
3464 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3465 the source at which the symbol was defined.
3467 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3468 method 'value'. The former indicates whether the symbol needs a
3469 frame in order to compute its value, and the latter computes the
3472 ** A new method 'referenced_value' on gdb.Value objects which can
3473 dereference pointer as well as C++ reference values.
3475 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3476 which return the global and static blocks (as gdb.Block objects),
3477 of the underlying symbol table, respectively.
3479 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3480 object associated with a PC value.
3482 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3483 of the address range occupied by code for the current source line.
3485 * Go language support.
3486 GDB now supports debugging programs written in the Go programming
3489 * GDBserver now supports stdio connections.
3490 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3492 * The binary "gdbtui" can no longer be built or installed.
3493 Use "gdb -tui" instead.
3495 * GDB will now print "flag" enums specially. A flag enum is one where
3496 all the enumerator values have no bits in common when pairwise
3497 "and"ed. When printing a value whose type is a flag enum, GDB will
3498 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3499 (gdb) print (enum E) 3
3502 * The filename part of a linespec will now match trailing components
3503 of a source file name. For example, "break gcc/expr.c:1000" will
3504 now set a breakpoint in build/gcc/expr.c, but not
3505 build/libcpp/expr.c.
3507 * The "info proc" and "generate-core-file" commands will now also
3508 work on remote targets connected to GDBserver on Linux.
3510 * The command "info catch" has been removed. It has been disabled
3511 since December 2007.
3513 * The "catch exception" and "catch assert" commands now accept
3514 a condition at the end of the command, much like the "break"
3515 command does. For instance:
3517 (gdb) catch exception Constraint_Error if Barrier = True
3519 Previously, it was possible to add a condition to such catchpoints,
3520 but it had to be done as a second step, after the catchpoint had been
3521 created, using the "condition" command.
3523 * The "info static-tracepoint-marker" command will now also work on
3524 native Linux targets with in-process agent.
3526 * GDB can now set breakpoints on inlined functions.
3528 * The .gdb_index section has been updated to include symbols for
3529 inlined functions. GDB will ignore older .gdb_index sections by
3530 default, which could cause symbol files to be loaded more slowly
3531 until their .gdb_index sections can be recreated. The new command
3532 "set use-deprecated-index-sections on" will cause GDB to use any older
3533 .gdb_index sections it finds. This will restore performance, but the
3534 ability to set breakpoints on inlined functions will be lost in symbol
3535 files with older .gdb_index sections.
3537 The .gdb_index section has also been updated to record more information
3538 about each symbol. This speeds up the "info variables", "info functions"
3539 and "info types" commands when used with programs having the .gdb_index
3540 section, as well as speeding up debugging with shared libraries using
3541 the .gdb_index section.
3543 * Ada support for GDB/MI Variable Objects has been added.
3545 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3550 ** New command -info-os is the MI equivalent of "info os".
3552 ** Output logs ("set logging" and related) now include MI output.
3556 ** "set use-deprecated-index-sections on|off"
3557 "show use-deprecated-index-sections on|off"
3558 Controls the use of deprecated .gdb_index sections.
3560 ** "catch load" and "catch unload" can be used to stop when a shared
3561 library is loaded or unloaded, respectively.
3563 ** "enable count" can be used to auto-disable a breakpoint after
3566 ** "info vtbl" can be used to show the virtual method tables for
3567 C++ and Java objects.
3569 ** "explore" and its sub commands "explore value" and "explore type"
3570 can be used to recursively explore values and types of
3571 expressions. These commands are available only if GDB is
3572 configured with '--with-python'.
3574 ** "info auto-load" shows status of all kinds of auto-loaded files,
3575 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3576 sequences of commands files, "info auto-load python-scripts"
3577 shows status of auto-loading Python script files,
3578 "info auto-load local-gdbinit" shows status of loading init file
3579 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3580 status of inferior specific thread debugging shared library loading.
3582 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3583 and "show auto-load-scripts" commands have been deprecated, use their
3584 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3585 and "show auto-load python-scripts" counterparts instead.
3587 ** "dprintf location,format,args..." creates a dynamic printf, which
3588 is basically a breakpoint that does a printf and immediately
3589 resumes your program's execution, so it is like a printf that you
3590 can insert dynamically at runtime instead of at compiletime.
3592 ** "set print symbol"
3594 Controls whether GDB attempts to display the symbol, if any,
3595 corresponding to addresses it prints. This defaults to "on", but
3596 you can set it to "off" to restore GDB's previous behavior.
3598 * Deprecated commands
3600 ** For the Renesas Super-H architecture, the "regs" command has been
3601 deprecated, and "info all-registers" should be used instead.
3605 Renesas RL78 rl78-*-elf
3606 HP OpenVMS ia64 ia64-hp-openvms*
3608 * GDBserver supports evaluation of breakpoint conditions. When
3609 support is advertised by GDBserver, GDB may be told to send the
3610 breakpoint conditions in bytecode form to GDBserver. GDBserver
3611 will only report the breakpoint trigger to GDB when its condition
3616 set mips compression
3617 show mips compression
3618 Select the compressed ISA encoding used in functions that have no symbol
3619 information available. The encoding can be set to either of:
3622 and is updated automatically from ELF file flags if available.
3624 set breakpoint condition-evaluation
3625 show breakpoint condition-evaluation
3626 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3627 GDBserver ("target"). Default option "auto" chooses the most efficient
3629 This option can improve debugger efficiency depending on the speed of the
3633 Disable auto-loading globally.
3636 Show auto-loading setting of all kinds of auto-loaded files.
3638 set auto-load gdb-scripts on|off
3639 show auto-load gdb-scripts
3640 Control auto-loading of GDB canned sequences of commands files.
3642 set auto-load python-scripts on|off
3643 show auto-load python-scripts
3644 Control auto-loading of Python script files.
3646 set auto-load local-gdbinit on|off
3647 show auto-load local-gdbinit
3648 Control loading of init file (.gdbinit) from current directory.
3650 set auto-load libthread-db on|off
3651 show auto-load libthread-db
3652 Control auto-loading of inferior specific thread debugging shared library.
3654 set auto-load scripts-directory <dir1>[:<dir2>...]
3655 show auto-load scripts-directory
3656 Set a list of directories from which to load auto-loaded scripts.
3657 Automatically loaded Python scripts and GDB scripts are located in one
3658 of the directories listed by this option.
3659 The delimiter (':' above) may differ according to the host platform.
3661 set auto-load safe-path <dir1>[:<dir2>...]
3662 show auto-load safe-path
3663 Set a list of directories from which it is safe to auto-load files.
3664 The delimiter (':' above) may differ according to the host platform.
3666 set debug auto-load on|off
3667 show debug auto-load
3668 Control display of debugging info for auto-loading the files above.
3670 set dprintf-style gdb|call|agent
3672 Control the way in which a dynamic printf is performed; "gdb"
3673 requests a GDB printf command, while "call" causes dprintf to call a
3674 function in the inferior. "agent" requests that the target agent
3675 (such as GDBserver) do the printing.
3677 set dprintf-function <expr>
3678 show dprintf-function
3679 set dprintf-channel <expr>
3680 show dprintf-channel
3681 Set the function and optional first argument to the call when using
3682 the "call" style of dynamic printf.
3684 set disconnected-dprintf on|off
3685 show disconnected-dprintf
3686 Control whether agent-style dynamic printfs continue to be in effect
3687 after GDB disconnects.
3689 * New configure options
3691 --with-auto-load-dir
3692 Configure default value for the 'set auto-load scripts-directory'
3693 setting above. It defaults to '$debugdir:$datadir/auto-load',
3694 $debugdir representing global debugging info directories (available
3695 via 'show debug-file-directory') and $datadir representing GDB's data
3696 directory (available via 'show data-directory').
3698 --with-auto-load-safe-path
3699 Configure default value for the 'set auto-load safe-path' setting
3700 above. It defaults to the --with-auto-load-dir setting.
3702 --without-auto-load-safe-path
3703 Set 'set auto-load safe-path' to '/', effectively disabling this
3706 * New remote packets
3708 z0/z1 conditional breakpoints extension
3710 The z0/z1 breakpoint insertion packets have been extended to carry
3711 a list of conditional expressions over to the remote stub depending on the
3712 condition evaluation mode. The use of this extension can be controlled
3713 via the "set remote conditional-breakpoints-packet" command.
3717 Specify the signals which the remote stub may pass to the debugged
3718 program without GDB involvement.
3720 * New command line options
3722 --init-command=FILE, -ix Like --command, -x but execute it
3723 before loading inferior.
3724 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3725 execute it before loading inferior.
3727 *** Changes in GDB 7.4
3729 * GDB now handles ambiguous linespecs more consistently; the existing
3730 FILE:LINE support has been expanded to other types of linespecs. A
3731 breakpoint will now be set on all matching locations in all
3732 inferiors, and locations will be added or removed according to
3735 * GDB now allows you to skip uninteresting functions and files when
3736 stepping with the "skip function" and "skip file" commands.
3738 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3739 and "show remote hardware-watchpoint-length-limit". These allows to
3740 set or show the maximum length limit (in bytes) of a remote
3741 target hardware watchpoint.
3743 This allows e.g. to use "unlimited" hardware watchpoints with the
3744 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3745 watchpoints are slower than real hardware watchpoints but are
3746 significantly faster than gdb software watchpoints.
3750 ** The register_pretty_printer function in module gdb.printing now takes
3751 an optional `replace' argument. If True, the new printer replaces any
3754 ** The "maint set python print-stack on|off" command has been
3755 deprecated and will be deleted in GDB 7.5.
3756 A new command: "set python print-stack none|full|message" has
3757 replaced it. Additionally, the default for "print-stack" is
3758 now "message", which just prints the error message without
3761 ** A prompt substitution hook (prompt_hook) is now available to the
3764 ** A new Python module, gdb.prompt has been added to the GDB Python
3765 modules library. This module provides functionality for
3766 escape sequences in prompts (used by set/show
3767 extended-prompt). These escape sequences are replaced by their
3768 corresponding value.
3770 ** Python commands and convenience-functions located in
3771 'data-directory'/python/gdb/command and
3772 'data-directory'/python/gdb/function are now automatically loaded
3775 ** Blocks now provide four new attributes. global_block and
3776 static_block will return the global and static blocks
3777 respectively. is_static and is_global are boolean attributes
3778 that indicate if the block is one of those two types.
3780 ** Symbols now provide the "type" attribute, the type of the symbol.
3782 ** The "gdb.breakpoint" function has been deprecated in favor of
3785 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3786 of a function. This class is based on the "finish" command
3787 available in the CLI.
3789 ** Type objects for struct and union types now allow access to
3790 the fields using standard Python dictionary (mapping) methods.
3791 For example, "some_type['myfield']" now works, as does
3792 "some_type.items()".
3794 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3797 ** A new function, "deep_items" has been added to the gdb.types
3798 module in the GDB Python modules library. This function returns
3799 an iterator over the fields of a struct or union type. Unlike
3800 the standard Python "iteritems" method, it will recursively traverse
3801 any anonymous fields.
3805 ** "*stopped" events can report several new "reason"s, such as
3808 ** Breakpoint changes are now notified using new async records, like
3809 "=breakpoint-modified".
3811 ** New command -ada-task-info.
3813 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3814 $sdir specifies the default system locations of shared libraries.
3815 $pdir specifies the directory where the libpthread used by the application
3818 GDB no longer looks in $sdir and $pdir after it has searched the directories
3819 mentioned in libthread-db-search-path. If you want to search those
3820 directories, they must be specified in libthread-db-search-path.
3821 The default value of libthread-db-search-path on GNU/Linux and Solaris
3822 systems is now "$sdir:$pdir".
3824 $pdir is not supported by gdbserver, it is currently ignored.
3825 $sdir is supported by gdbserver.
3827 * New configure option --with-iconv-bin.
3828 When using the internationalization support like the one in the GNU C
3829 library, GDB will invoke the "iconv" program to get a list of supported
3830 character sets. If this program lives in a non-standard location, one can
3831 use this option to specify where to find it.
3833 * When natively debugging programs on PowerPC BookE processors running
3834 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3835 watchpoints, which specify a mask in addition to an address to watch.
3836 The mask specifies that some bits of an address (the bits which are
3837 reset in the mask) should be ignored when matching the address accessed
3838 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3839 section in the user manual for more details.
3841 * The new option --once causes GDBserver to stop listening for connections once
3842 the first connection is made. The listening port used by GDBserver will
3843 become available after that.
3845 * New commands "info macros" and "alias" have been added.
3847 * New function parameters suffix @entry specifies value of function parameter
3848 at the time the function got called. Entry values are available only since
3854 "!" is now an alias of the "shell" command.
3855 Note that no space is needed between "!" and SHELL COMMAND.
3859 watch EXPRESSION mask MASK_VALUE
3860 The watch command now supports the mask argument which allows creation
3861 of masked watchpoints, if the current architecture supports this feature.
3863 info auto-load-scripts [REGEXP]
3864 This command was formerly named "maintenance print section-scripts".
3865 It is now generally useful and is no longer a maintenance-only command.
3867 info macro [-all] [--] MACRO
3868 The info macro command has new options `-all' and `--'. The first for
3869 printing all definitions of a macro. The second for explicitly specifying
3870 the end of arguments and the beginning of the macro name in case the macro
3871 name starts with a hyphen.
3873 collect[/s] EXPRESSIONS
3874 The tracepoint collect command now takes an optional modifier "/s"
3875 that directs it to dereference pointer-to-character types and
3876 collect the bytes of memory up to a zero byte. The behavior is
3877 similar to what you see when you use the regular print command on a
3878 string. An optional integer following the "/s" sets a bound on the
3879 number of bytes that will be collected.
3882 The trace start command now interprets any supplied arguments as a
3883 note to be recorded with the trace run, with an effect similar to
3884 setting the variable trace-notes.
3887 The trace stop command now interprets any arguments as a note to be
3888 mentioned along with the tstatus report that the trace was stopped
3889 with a command. The effect is similar to setting the variable
3892 * Tracepoints can now be enabled and disabled at any time after a trace
3893 experiment has been started using the standard "enable" and "disable"
3894 commands. It is now possible to start a trace experiment with no enabled
3895 tracepoints; GDB will display a warning, but will allow the experiment to
3896 begin, assuming that tracepoints will be enabled as needed while the trace
3899 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3900 locations with 4-byte instructions, when they were previously
3901 limited to locations with instructions of 5 bytes or longer.
3905 set debug dwarf2-read
3906 show debug dwarf2-read
3907 Turns on or off display of debugging messages related to reading
3908 DWARF debug info. The default is off.
3910 set debug symtab-create
3911 show debug symtab-create
3912 Turns on or off display of debugging messages related to symbol table
3913 creation. The default is off.
3916 show extended-prompt
3917 Set the GDB prompt, and allow escape sequences to be inserted to
3918 display miscellaneous information (see 'help set extended-prompt'
3919 for the list of sequences). This prompt (and any information
3920 accessed through the escape sequences) is updated every time the
3921 prompt is displayed.
3923 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3924 show print entry-values
3925 Set printing of frame argument values at function entry. In some cases
3926 GDB can determine the value of function argument which was passed by the
3927 function caller, even if the value was modified inside the called function.
3929 set debug entry-values
3930 show debug entry-values
3931 Control display of debugging info for determining frame argument values at
3932 function entry and virtual tail call frames.
3934 set basenames-may-differ
3935 show basenames-may-differ
3936 Set whether a source file may have multiple base names.
3937 (A "base name" is the name of a file with the directory part removed.
3938 Example: The base name of "/home/user/hello.c" is "hello.c".)
3939 If set, GDB will canonicalize file names (e.g., expand symlinks)
3940 before comparing them. Canonicalization is an expensive operation,
3941 but it allows the same file be known by more than one base name.
3942 If not set (the default), all source files are assumed to have just
3943 one base name, and gdb will do file name comparisons more efficiently.
3949 Set a user name and notes for the current and any future trace runs.
3950 This is useful for long-running and/or disconnected traces, to
3951 inform others (or yourself) as to who is running the trace, supply
3952 contact information, or otherwise explain what is going on.
3954 set trace-stop-notes
3955 show trace-stop-notes
3956 Set a note attached to the trace run, that is displayed when the
3957 trace has been stopped by a tstop command. This is useful for
3958 instance as an explanation, if you are stopping a trace run that was
3959 started by someone else.
3961 * New remote packets
3965 Dynamically enable a tracepoint in a started trace experiment.
3969 Dynamically disable a tracepoint in a started trace experiment.
3973 Set the user and notes of the trace run.
3977 Query the current status of a tracepoint.
3981 Query the minimum length of instruction at which a fast tracepoint may
3984 * Dcache size (number of lines) and line-size are now runtime-configurable
3985 via "set dcache line" and "set dcache line-size" commands.
3989 Texas Instruments TMS320C6x tic6x-*-*
3993 Renesas RL78 rl78-*-elf
3995 *** Changes in GDB 7.3.1
3997 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3999 *** Changes in GDB 7.3
4001 * GDB has a new command: "thread find [REGEXP]".
4002 It finds the thread id whose name, target id, or thread extra info
4003 matches the given regular expression.
4005 * The "catch syscall" command now works on mips*-linux* targets.
4007 * The -data-disassemble MI command now supports modes 2 and 3 for
4008 dumping the instruction opcodes.
4010 * New command line options
4012 -data-directory DIR Specify DIR as the "data-directory".
4013 This is mostly for testing purposes.
4015 * The "maint set python auto-load on|off" command has been renamed to
4016 "set auto-load-scripts on|off".
4018 * GDB has a new command: "set directories".
4019 It is like the "dir" command except that it replaces the
4020 source path list instead of augmenting it.
4022 * GDB now understands thread names.
4024 On GNU/Linux, "info threads" will display the thread name as set by
4025 prctl or pthread_setname_np.
4027 There is also a new command, "thread name", which can be used to
4028 assign a name internally for GDB to display.
4031 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4032 has been integrated into GDB.
4036 ** The function gdb.Write now accepts an optional keyword 'stream'.
4037 This keyword, when provided, will direct the output to either
4038 stdout, stderr, or GDB's logging output.
4040 ** Parameters can now be be sub-classed in Python, and in particular
4041 you may implement the get_set_doc and get_show_doc functions.
4042 This improves how Parameter set/show documentation is processed
4043 and allows for more dynamic content.
4045 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4046 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4047 have an is_valid method.
4049 ** Breakpoints can now be sub-classed in Python, and in particular
4050 you may implement a 'stop' function that is executed each time
4051 the inferior reaches that breakpoint.
4053 ** New function gdb.lookup_global_symbol looks up a global symbol.
4055 ** GDB values in Python are now callable if the value represents a
4056 function. For example, if 'some_value' represents a function that
4057 takes two integer parameters and returns a value, you can call
4058 that function like so:
4060 result = some_value (10,20)
4062 ** Module gdb.types has been added.
4063 It contains a collection of utilities for working with gdb.Types objects:
4064 get_basic_type, has_field, make_enum_dict.
4066 ** Module gdb.printing has been added.
4067 It contains utilities for writing and registering pretty-printers.
4068 New classes: PrettyPrinter, SubPrettyPrinter,
4069 RegexpCollectionPrettyPrinter.
4070 New function: register_pretty_printer.
4072 ** New commands "info pretty-printers", "enable pretty-printer" and
4073 "disable pretty-printer" have been added.
4075 ** gdb.parameter("directories") is now available.
4077 ** New function gdb.newest_frame returns the newest frame in the
4080 ** The gdb.InferiorThread class has a new "name" attribute. This
4081 holds the thread's name.
4083 ** Python Support for Inferior events.
4084 Python scripts can add observers to be notified of events
4085 occurring in the process being debugged.
4086 The following events are currently supported:
4087 - gdb.events.cont Continue event.
4088 - gdb.events.exited Inferior exited event.
4089 - gdb.events.stop Signal received, and Breakpoint hit events.
4093 ** GDB now puts template parameters in scope when debugging in an
4094 instantiation. For example, if you have:
4096 template<int X> int func (void) { return X; }
4098 then if you step into func<5>, "print X" will show "5". This
4099 feature requires proper debuginfo support from the compiler; it
4100 was added to GCC 4.5.
4102 ** The motion commands "next", "finish", "until", and "advance" now
4103 work better when exceptions are thrown. In particular, GDB will
4104 no longer lose control of the inferior; instead, the GDB will
4105 stop the inferior at the point at which the exception is caught.
4106 This functionality requires a change in the exception handling
4107 code that was introduced in GCC 4.5.
4109 * GDB now follows GCC's rules on accessing volatile objects when
4110 reading or writing target state during expression evaluation.
4111 One notable difference to prior behavior is that "print x = 0"
4112 no longer generates a read of x; the value of the assignment is
4113 now always taken directly from the value being assigned.
4115 * GDB now has some support for using labels in the program's source in
4116 linespecs. For instance, you can use "advance label" to continue
4117 execution to a label.
4119 * GDB now has support for reading and writing a new .gdb_index
4120 section. This section holds a fast index of DWARF debugging
4121 information and can be used to greatly speed up GDB startup and
4122 operation. See the documentation for `save gdb-index' for details.
4124 * The "watch" command now accepts an optional "-location" argument.
4125 When used, this causes GDB to watch the memory referred to by the
4126 expression. Such a watchpoint is never deleted due to it going out
4129 * GDB now supports thread debugging of core dumps on GNU/Linux.
4131 GDB now activates thread debugging using the libthread_db library
4132 when debugging GNU/Linux core dumps, similarly to when debugging
4133 live processes. As a result, when debugging a core dump file, GDB
4134 is now able to display pthread_t ids of threads. For example, "info
4135 threads" shows the same output as when debugging the process when it
4136 was live. In earlier releases, you'd see something like this:
4139 * 1 LWP 6780 main () at main.c:10
4141 While now you see this:
4144 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4146 It is also now possible to inspect TLS variables when debugging core
4149 When debugging a core dump generated on a machine other than the one
4150 used to run GDB, you may need to point GDB at the correct
4151 libthread_db library with the "set libthread-db-search-path"
4152 command. See the user manual for more details on this command.
4154 * When natively debugging programs on PowerPC BookE processors running
4155 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4156 which stop execution of the inferior whenever it executes an instruction
4157 at any address within the specified range. See the "PowerPC Embedded"
4158 section in the user manual for more details.
4160 * New features in the GDB remote stub, GDBserver
4162 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4163 and i686 LynxOS (version 5.x).
4165 ** GDBserver is now supported on Blackfin Linux.
4167 * New native configurations
4169 ia64 HP-UX ia64-*-hpux*
4173 Analog Devices, Inc. Blackfin Processor bfin-*
4175 * Ada task switching is now supported on sparc-elf targets when
4176 debugging a program using the Ravenscar Profile. For more information,
4177 see the "Tasking Support when using the Ravenscar Profile" section
4178 in the GDB user manual.
4180 * Guile support was removed.
4182 * New features in the GNU simulator
4184 ** The --map-info flag lists all known core mappings.
4186 ** CFI flashes may be simulated via the "cfi" device.
4188 *** Changes in GDB 7.2
4190 * Shared library support for remote targets by default
4192 When GDB is configured for a generic, non-OS specific target, like
4193 for example, --target=arm-eabi or one of the many *-*-elf targets,
4194 GDB now queries remote stubs for loaded shared libraries using the
4195 `qXfer:libraries:read' packet. Previously, shared library support
4196 was always disabled for such configurations.
4200 ** Argument Dependent Lookup (ADL)
4202 In C++ ADL lookup directs function search to the namespaces of its
4203 arguments even if the namespace has not been imported.
4213 Here the compiler will search for `foo' in the namespace of 'b'
4214 and find A::foo. GDB now supports this. This construct is commonly
4215 used in the Standard Template Library for operators.
4217 ** Improved User Defined Operator Support
4219 In addition to member operators, GDB now supports lookup of operators
4220 defined in a namespace and imported with a `using' directive, operators
4221 defined in the global scope, operators imported implicitly from an
4222 anonymous namespace, and the ADL operators mentioned in the previous
4224 GDB now also supports proper overload resolution for all the previously
4225 mentioned flavors of operators.
4227 ** static const class members
4229 Printing of static const class members that are initialized in the
4230 class definition has been fixed.
4232 * Windows Thread Information Block access.
4234 On Windows targets, GDB now supports displaying the Windows Thread
4235 Information Block (TIB) structure. This structure is visible either
4236 by using the new command `info w32 thread-information-block' or, by
4237 dereferencing the new convenience variable named `$_tlb', a
4238 thread-specific pointer to the TIB. This feature is also supported
4239 when remote debugging using GDBserver.
4241 * Static tracepoints
4243 Static tracepoints are calls in the user program into a tracing
4244 library. One such library is a port of the LTTng kernel tracer to
4245 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4246 When debugging with GDBserver, GDB now supports combining the GDB
4247 tracepoint machinery with such libraries. For example: the user can
4248 use GDB to probe a static tracepoint marker (a call from the user
4249 program into the tracing library) with the new "strace" command (see
4250 "New commands" below). This creates a "static tracepoint" in the
4251 breakpoint list, that can be manipulated with the same feature set
4252 as fast and regular tracepoints. E.g., collect registers, local and
4253 global variables, collect trace state variables, and define
4254 tracepoint conditions. In addition, the user can collect extra
4255 static tracepoint marker specific data, by collecting the new
4256 $_sdata internal variable. When analyzing the trace buffer, you can
4257 inspect $_sdata like any other variable available to GDB. For more
4258 information, see the "Tracepoints" chapter in GDB user manual. New
4259 remote packets have been defined to support static tracepoints, see
4260 the "New remote packets" section below.
4262 * Better reconstruction of tracepoints after disconnected tracing
4264 GDB will attempt to download the original source form of tracepoint
4265 definitions when starting a trace run, and then will upload these
4266 upon reconnection to the target, resulting in a more accurate
4267 reconstruction of the tracepoints that are in use on the target.
4271 You can now exercise direct control over the ways that GDB can
4272 affect your program. For instance, you can disallow the setting of
4273 breakpoints, so that the program can run continuously (assuming
4274 non-stop mode). In addition, the "observer" variable is available
4275 to switch all of the different controls; in observer mode, GDB
4276 cannot affect the target's behavior at all, which is useful for
4277 tasks like diagnosing live systems in the field.
4279 * The new convenience variable $_thread holds the number of the
4282 * New remote packets
4286 Return the address of the Windows Thread Information Block of a given thread.
4290 In response to several of the tracepoint packets, the target may now
4291 also respond with a number of intermediate `qRelocInsn' request
4292 packets before the final result packet, to have GDB handle
4293 relocating an instruction to execute at a different address. This
4294 is particularly useful for stubs that support fast tracepoints. GDB
4295 reports support for this feature in the qSupported packet.
4299 List static tracepoint markers in the target program.
4303 List static tracepoint markers at a given address in the target
4306 qXfer:statictrace:read
4308 Read the static trace data collected (by a `collect $_sdata'
4309 tracepoint action). The remote stub reports support for this packet
4310 to gdb's qSupported query.
4314 Send the current settings of GDB's permission flags.
4318 Send part of the source (textual) form of a tracepoint definition,
4319 which includes location, conditional, and action list.
4321 * The source command now accepts a -s option to force searching for the
4322 script in the source search path even if the script name specifies
4325 * New features in the GDB remote stub, GDBserver
4327 - GDBserver now support tracepoints (including fast tracepoints, and
4328 static tracepoints). The feature is currently supported by the
4329 i386-linux and amd64-linux builds. See the "Tracepoints support
4330 in gdbserver" section in the manual for more information.
4332 GDBserver JIT compiles the tracepoint's conditional agent
4333 expression bytecode into native code whenever possible for low
4334 overhead dynamic tracepoints conditionals. For such tracepoints,
4335 an expression that examines program state is evaluated when the
4336 tracepoint is reached, in order to determine whether to capture
4337 trace data. If the condition is simple and false, processing the
4338 tracepoint finishes very quickly and no data is gathered.
4340 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4341 for static tracepoints support.
4343 - GDBserver now supports x86_64 Windows 64-bit debugging.
4345 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4346 it understands register description.
4348 * The --batch flag now disables pagination and queries.
4350 * X86 general purpose registers
4352 GDB now supports reading/writing byte, word and double-word x86
4353 general purpose registers directly. This means you can use, say,
4354 $ah or $ax to refer, respectively, to the byte register AH and
4355 16-bit word register AX that are actually portions of the 32-bit
4356 register EAX or 64-bit register RAX.
4358 * The `commands' command now accepts a range of breakpoints to modify.
4359 A plain `commands' following a command that creates multiple
4360 breakpoints affects all the breakpoints set by that command. This
4361 applies to breakpoints set by `rbreak', and also applies when a
4362 single `break' command creates multiple breakpoints (e.g.,
4363 breakpoints on overloaded c++ functions).
4365 * The `rbreak' command now accepts a filename specification as part of
4366 its argument, limiting the functions selected by the regex to those
4367 in the specified file.
4369 * Support for remote debugging Windows and SymbianOS shared libraries
4370 from Unix hosts has been improved. Non Windows GDB builds now can
4371 understand target reported file names that follow MS-DOS based file
4372 system semantics, such as file names that include drive letters and
4373 use the backslash character as directory separator. This makes it
4374 possible to transparently use the "set sysroot" and "set
4375 solib-search-path" on Unix hosts to point as host copies of the
4376 target's shared libraries. See the new command "set
4377 target-file-system-kind" described below, and the "Commands to
4378 specify files" section in the user manual for more information.
4382 eval template, expressions...
4383 Convert the values of one or more expressions under the control
4384 of the string template to a command line, and call it.
4386 set target-file-system-kind unix|dos-based|auto
4387 show target-file-system-kind
4388 Set or show the assumed file system kind for target reported file
4391 save breakpoints <filename>
4392 Save all current breakpoint definitions to a file suitable for use
4393 in a later debugging session. To read the saved breakpoint
4394 definitions, use the `source' command.
4396 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4399 info static-tracepoint-markers
4400 Display information about static tracepoint markers in the target.
4402 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4403 Define a static tracepoint by probing a marker at the given
4404 function, line, address, or marker ID.
4408 Enable and disable observer mode.
4410 set may-write-registers on|off
4411 set may-write-memory on|off
4412 set may-insert-breakpoints on|off
4413 set may-insert-tracepoints on|off
4414 set may-insert-fast-tracepoints on|off
4415 set may-interrupt on|off
4416 Set individual permissions for GDB effects on the target. Note that
4417 some of these settings can have undesirable or surprising
4418 consequences, particularly when changed in the middle of a session.
4419 For instance, disabling the writing of memory can prevent
4420 breakpoints from being inserted, cause single-stepping to fail, or
4421 even crash your program, if you disable after breakpoints have been
4422 inserted. However, GDB should not crash.
4424 set record memory-query on|off
4425 show record memory-query
4426 Control whether to stop the inferior if memory changes caused
4427 by an instruction cannot be recorded.
4432 The disassemble command now supports "start,+length" form of two arguments.
4436 ** GDB now provides a new directory location, called the python directory,
4437 where Python scripts written for GDB can be installed. The location
4438 of that directory is <data-directory>/python, where <data-directory>
4439 is the GDB data directory. For more details, see section `Scripting
4440 GDB using Python' in the manual.
4442 ** The GDB Python API now has access to breakpoints, symbols, symbol
4443 tables, program spaces, inferiors, threads and frame's code blocks.
4444 Additionally, GDB Parameters can now be created from the API, and
4445 manipulated via set/show in the CLI.
4447 ** New functions gdb.target_charset, gdb.target_wide_charset,
4448 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4450 ** New exception gdb.GdbError.
4452 ** Pretty-printers are now also looked up in the current program space.
4454 ** Pretty-printers can now be individually enabled and disabled.
4456 ** GDB now looks for names of Python scripts to auto-load in a
4457 special section named `.debug_gdb_scripts', in addition to looking
4458 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4460 * Tracepoint actions were unified with breakpoint commands. In particular,
4461 there are no longer differences in "info break" output for breakpoints and
4462 tracepoints and the "commands" command can be used for both tracepoints and
4463 regular breakpoints.
4467 ARM Symbian arm*-*-symbianelf*
4469 * D language support.
4470 GDB now supports debugging programs written in the D programming
4473 * GDB now supports the extended ptrace interface for PowerPC which is
4474 available since Linux kernel version 2.6.34. This automatically enables
4475 any hardware breakpoints and additional hardware watchpoints available in
4476 the processor. The old ptrace interface exposes just one hardware
4477 watchpoint and no hardware breakpoints.
4479 * GDB is now able to use the Data Value Compare (DVC) register available on
4480 embedded PowerPC processors to implement in hardware simple watchpoint
4481 conditions of the form:
4483 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4485 This works in native GDB running on Linux kernels with the extended ptrace
4486 interface mentioned above.
4488 *** Changes in GDB 7.1
4492 ** Namespace Support
4494 GDB now supports importing of namespaces in C++. This enables the
4495 user to inspect variables from imported namespaces. Support for
4496 namepace aliasing has also been added. So, if a namespace is
4497 aliased in the current scope (e.g. namepace C=A; ) the user can
4498 print variables using the alias (e.g. (gdb) print C::x).
4502 All known bugs relating to the printing of virtual base class were
4503 fixed. It is now possible to call overloaded static methods using a
4508 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4509 and reinterpret_cast<> are now handled by the C++ expression parser.
4513 Xilinx MicroBlaze microblaze-*-*
4518 Xilinx MicroBlaze microblaze
4521 * Multi-program debugging.
4523 GDB now has support for multi-program (a.k.a. multi-executable or
4524 multi-exec) debugging. This allows for debugging multiple inferiors
4525 simultaneously each running a different program under the same GDB
4526 session. See "Debugging Multiple Inferiors and Programs" in the
4527 manual for more information. This implied some user visible changes
4528 in the multi-inferior support. For example, "info inferiors" now
4529 lists inferiors that are not running yet or that have exited
4530 already. See also "New commands" and "New options" below.
4532 * New tracing features
4534 GDB's tracepoint facility now includes several new features:
4536 ** Trace state variables
4538 GDB tracepoints now include support for trace state variables, which
4539 are variables managed by the target agent during a tracing
4540 experiment. They are useful for tracepoints that trigger each
4541 other, so for instance one tracepoint can count hits in a variable,
4542 and then a second tracepoint has a condition that is true when the
4543 count reaches a particular value. Trace state variables share the
4544 $-syntax of GDB convenience variables, and can appear in both
4545 tracepoint actions and condition expressions. Use the "tvariable"
4546 command to create, and "info tvariables" to view; see "Trace State
4547 Variables" in the manual for more detail.
4551 GDB now includes an option for defining fast tracepoints, which
4552 targets may implement more efficiently, such as by installing a jump
4553 into the target agent rather than a trap instruction. The resulting
4554 speedup can be by two orders of magnitude or more, although the
4555 tradeoff is that some program locations on some target architectures
4556 might not allow fast tracepoint installation, for instance if the
4557 instruction to be replaced is shorter than the jump. To request a
4558 fast tracepoint, use the "ftrace" command, with syntax identical to
4559 the regular trace command.
4561 ** Disconnected tracing
4563 It is now possible to detach GDB from the target while it is running
4564 a trace experiment, then reconnect later to see how the experiment
4565 is going. In addition, a new variable disconnected-tracing lets you
4566 tell the target agent whether to continue running a trace if the
4567 connection is lost unexpectedly.
4571 GDB now has the ability to save the trace buffer into a file, and
4572 then use that file as a target, similarly to you can do with
4573 corefiles. You can select trace frames, print data that was
4574 collected in them, and use tstatus to display the state of the
4575 tracing run at the moment that it was saved. To create a trace
4576 file, use "tsave <filename>", and to use it, do "target tfile
4579 ** Circular trace buffer
4581 You can ask the target agent to handle the trace buffer as a
4582 circular buffer, discarding the oldest trace frames to make room for
4583 newer ones, by setting circular-trace-buffer to on. This feature may
4584 not be available for all target agents.
4589 The disassemble command, when invoked with two arguments, now requires
4590 the arguments to be comma-separated.
4593 The info variables command now displays variable definitions. Files
4594 which only declare a variable are not shown.
4597 The source command is now capable of sourcing Python scripts.
4598 This feature is dependent on the debugger being build with Python
4601 Related to this enhancement is also the introduction of a new command
4602 "set script-extension" (see below).
4604 * New commands (for set/show, see "New options" below)
4606 record save [<FILENAME>]
4607 Save a file (in core file format) containing the process record
4608 execution log for replay debugging at a later time.
4610 record restore <FILENAME>
4611 Restore the process record execution log that was saved at an
4612 earlier time, for replay debugging.
4614 add-inferior [-copies <N>] [-exec <FILENAME>]
4617 clone-inferior [-copies <N>] [ID]
4618 Make a new inferior ready to execute the same program another
4619 inferior has loaded.
4624 maint info program-spaces
4625 List the program spaces loaded into GDB.
4627 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4628 show remote interrupt-sequence
4629 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4630 as the sequence to the remote target in order to interrupt the execution.
4631 Ctrl-C is a default. Some system prefers BREAK which is high level of
4632 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4633 Magic SysRq g. It is BREAK signal and character 'g'.
4635 set remote interrupt-on-connect [on | off]
4636 show remote interrupt-on-connect
4637 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4638 remote target when gdb connects to it. This is needed when you debug
4641 set remotebreak [on | off]
4643 Deprecated. Use "set/show remote interrupt-sequence" instead.
4645 tvariable $NAME [ = EXP ]
4646 Create or modify a trace state variable.
4649 List trace state variables and their values.
4651 delete tvariable $NAME ...
4652 Delete one or more trace state variables.
4655 Evaluate the given expressions without collecting anything into the
4656 trace buffer. (Valid in tracepoint actions only.)
4658 ftrace FN / FILE:LINE / *ADDR
4659 Define a fast tracepoint at the given function, line, or address.
4661 * New expression syntax
4663 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4664 GDB now parses 0b101010 identically with 42.
4668 set follow-exec-mode new|same
4669 show follow-exec-mode
4670 Control whether GDB reuses the same inferior across an exec call or
4671 creates a new one. This is useful to be able to restart the old
4672 executable after the inferior having done an exec call.
4674 set default-collect EXPR, ...
4675 show default-collect
4676 Define a list of expressions to be collected at each tracepoint.
4677 This is a useful way to ensure essential items are not overlooked,
4678 such as registers or a critical global variable.
4680 set disconnected-tracing
4681 show disconnected-tracing
4682 If set to 1, the target is instructed to continue tracing if it
4683 loses its connection to GDB. If 0, the target is to stop tracing
4686 set circular-trace-buffer
4687 show circular-trace-buffer
4688 If set to on, the target is instructed to use a circular trace buffer
4689 and discard the oldest trace frames instead of stopping the trace due
4690 to a full trace buffer. If set to off, the trace stops when the buffer
4691 fills up. Some targets may not support this.
4693 set script-extension off|soft|strict
4694 show script-extension
4695 If set to "off", the debugger does not perform any script language
4696 recognition, and all sourced files are assumed to be GDB scripts.
4697 If set to "soft" (the default), files are sourced according to
4698 filename extension, falling back to GDB scripts if the first
4700 If set to "strict", files are sourced according to filename extension.
4702 set ada trust-PAD-over-XVS on|off
4703 show ada trust-PAD-over-XVS
4704 If off, activate a workaround against a bug in the debugging information
4705 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4706 the GCC sources for more information about the GNAT encoding and
4707 PAD types in particular). It is always safe to set this option to
4708 off, but this introduces a slight performance penalty. The default
4711 * Python API Improvements
4713 ** GDB provides the new class gdb.LazyString. This is useful in
4714 some pretty-printing cases. The new method gdb.Value.lazy_string
4715 provides a simple way to create objects of this type.
4717 ** The fields returned by gdb.Type.fields now have an
4718 `is_base_class' attribute.
4720 ** The new method gdb.Type.range returns the range of an array type.
4722 ** The new method gdb.parse_and_eval can be used to parse and
4723 evaluate an expression.
4725 * New remote packets
4728 Define a trace state variable.
4731 Get the current value of a trace state variable.
4734 Set desired tracing behavior upon disconnection.
4737 Set the trace buffer to be linear or circular.
4740 Get data about the tracepoints currently in use.
4744 Process record now works correctly with hardware watchpoints.
4746 Multiple bug fixes have been made to the mips-irix port, making it
4747 much more reliable. In particular:
4748 - Debugging threaded applications is now possible again. Previously,
4749 GDB would hang while starting the program, or while waiting for
4750 the program to stop at a breakpoint.
4751 - Attaching to a running process no longer hangs.
4752 - An error occurring while loading a core file has been fixed.
4753 - Changing the value of the PC register now works again. This fixes
4754 problems observed when using the "jump" command, or when calling
4755 a function from GDB, or even when assigning a new value to $pc.
4756 - With the "finish" and "return" commands, the return value for functions
4757 returning a small array is now correctly printed.
4758 - It is now possible to break on shared library code which gets executed
4759 during a shared library init phase (code executed while executing
4760 their .init section). Previously, the breakpoint would have no effect.
4761 - GDB is now able to backtrace through the signal handler for
4762 non-threaded programs.
4764 PIE (Position Independent Executable) programs debugging is now supported.
4765 This includes debugging execution of PIC (Position Independent Code) shared
4766 libraries although for that, it should be possible to run such libraries as an
4769 *** Changes in GDB 7.0
4771 * GDB now has an interface for JIT compilation. Applications that
4772 dynamically generate code can create symbol files in memory and register
4773 them with GDB. For users, the feature should work transparently, and
4774 for JIT developers, the interface is documented in the GDB manual in the
4775 "JIT Compilation Interface" chapter.
4777 * Tracepoints may now be conditional. The syntax is as for
4778 breakpoints; either an "if" clause appended to the "trace" command,
4779 or the "condition" command is available. GDB sends the condition to
4780 the target for evaluation using the same bytecode format as is used
4781 for tracepoint actions.
4783 * The disassemble command now supports: an optional /r modifier, print the
4784 raw instructions in hex as well as in symbolic form, and an optional /m
4785 modifier to print mixed source+assembly.
4787 * Process record and replay
4789 In a architecture environment that supports ``process record and
4790 replay'', ``process record and replay'' target can record a log of
4791 the process execution, and replay it with both forward and reverse
4794 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4795 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4796 set execution-direction {forward|reverse}, for targets that support
4799 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4800 feature is available with a native GDB running on kernel version
4803 * GDB now has support for multi-byte and wide character sets on the
4804 target. Strings whose character type is wchar_t, char16_t, or
4805 char32_t are now correctly printed. GDB supports wide- and unicode-
4806 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4807 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4808 `printf'. This feature requires iconv to work properly; if your
4809 system does not have a working iconv, GDB can use GNU libiconv. See
4810 the installation instructions for more information.
4812 * GDB now supports automatic retrieval of shared library files from
4813 remote targets. To use this feature, specify a system root that begins
4814 with the `remote:' prefix, either via the `set sysroot' command or via
4815 the `--with-sysroot' configure-time option.
4817 * "info sharedlibrary" now takes an optional regex of libraries to show,
4818 and it now reports if a shared library has no debugging information.
4820 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4821 now complete on file names.
4823 * When completing in expressions, gdb will attempt to limit
4824 completions to allowable structure or union fields, where appropriate.
4825 For instance, consider:
4827 # struct example { int f1; double f2; };
4828 # struct example variable;
4831 If the user types TAB at the end of this command line, the available
4832 completions will be "f1" and "f2".
4834 * Inlined functions are now supported. They show up in backtraces, and
4835 the "step", "next", and "finish" commands handle them automatically.
4837 * GDB now supports the token-splicing (##) and stringification (#)
4838 operators when expanding macros. It also supports variable-arity
4841 * GDB now supports inspecting extra signal information, exported by
4842 the new $_siginfo convenience variable. The feature is currently
4843 implemented on linux ARM, i386 and amd64.
4845 * GDB can now display the VFP floating point registers and NEON vector
4846 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4847 can provide these registers (requires Linux 2.6.30 or later). Remote
4848 and simulator targets may also provide them.
4850 * New remote packets
4853 Search memory for a sequence of bytes.
4856 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4857 operation over reliable transport links. Use of this packet is
4858 controlled by the `set remote noack-packet' command.
4861 Kill the process with the specified process ID. Use this in preference
4862 to `k' when multiprocess protocol extensions are supported.
4865 Obtains additional operating system information
4869 Read or write additional signal information.
4871 * Removed remote protocol undocumented extension
4873 An undocumented extension to the remote protocol's `S' stop reply
4874 packet that permitted the stub to pass a process id was removed.
4875 Remote servers should use the `T' stop reply packet instead.
4877 * GDB now supports multiple function calling conventions according to the
4878 DWARF-2 DW_AT_calling_convention function attribute.
4880 * The SH target utilizes the aforementioned change to distinguish between gcc
4881 and Renesas calling convention. It also adds the new CLI commands
4882 `set/show sh calling-convention'.
4884 * GDB can now read compressed debug sections, as produced by GNU gold
4885 with the --compress-debug-sections=zlib flag.
4887 * 64-bit core files are now supported on AIX.
4889 * Thread switching is now supported on Tru64.
4891 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4892 which will be allocated using malloc later in program execution.
4894 * The qXfer:libraries:read remote protocol packet now allows passing a
4895 list of section offsets.
4897 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4898 conditions handling signals delivered during attach or thread creation
4899 have also been fixed.
4901 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4902 From the user's standpoint, all unqualified instances of True and False
4903 are treated as the standard definitions, regardless of context.
4905 * GDB now parses C++ symbol and type names more flexibly. For
4908 template<typename T> class C { };
4911 GDB will now correctly handle all of:
4913 ptype C<char const *>
4914 ptype C<char const*>
4915 ptype C<const char *>
4916 ptype C<const char*>
4918 * New features in the GDB remote stub, gdbserver
4920 - The "--wrapper" command-line argument tells gdbserver to use a
4921 wrapper program to launch programs for debugging.
4923 - On PowerPC and S/390 targets, it is now possible to use a single
4924 gdbserver executable to debug both 32-bit and 64-bit programs.
4925 (This requires gdbserver itself to be built as a 64-bit executable.)
4927 - gdbserver uses the new noack protocol mode for TCP connections to
4928 reduce communications latency, if also supported and enabled in GDB.
4930 - Support for the sparc64-linux-gnu target is now included in
4933 - The amd64-linux build of gdbserver now supports debugging both
4934 32-bit and 64-bit programs.
4936 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4937 now support hardware watchpoints, and will use them automatically
4942 GDB now has support for scripting using Python. Whether this is
4943 available is determined at configure time.
4945 New GDB commands can now be written in Python.
4947 * Ada tasking support
4949 Ada tasks can now be inspected in GDB. The following commands have
4953 Print the list of Ada tasks.
4955 Print detailed information about task number N.
4957 Print the task number of the current task.
4959 Switch the context of debugging to task number N.
4961 * Support for user-defined prefixed commands. The "define" command can
4962 add new commands to existing prefixes, e.g. "target".
4964 * Multi-inferior, multi-process debugging.
4966 GDB now has generalized support for multi-inferior debugging. See
4967 "Debugging Multiple Inferiors" in the manual for more information.
4968 Although availability still depends on target support, the command
4969 set is more uniform now. The GNU/Linux specific multi-forks support
4970 has been migrated to this new framework. This implied some user
4971 visible changes; see "New commands" and also "Removed commands"
4974 * Target descriptions can now describe the target OS ABI. See the
4975 "Target Description Format" section in the user manual for more
4978 * Target descriptions can now describe "compatible" architectures
4979 to indicate that the target can execute applications for a different
4980 architecture in addition to those for the main target architecture.
4981 See the "Target Description Format" section in the user manual for
4984 * Multi-architecture debugging.
4986 GDB now includes general supports for debugging applications on
4987 hybrid systems that use more than one single processor architecture
4988 at the same time. Each such hybrid architecture still requires
4989 specific support to be added. The only hybrid architecture supported
4990 in this version of GDB is the Cell Broadband Engine.
4992 * GDB now supports integrated debugging of Cell/B.E. applications that
4993 use both the PPU and SPU architectures. To enable support for hybrid
4994 Cell/B.E. debugging, you need to configure GDB to support both the
4995 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4996 --enable-targets configure option.
4998 * Non-stop mode debugging.
5000 For some targets, GDB now supports an optional mode of operation in
5001 which you can examine stopped threads while other threads continue
5002 to execute freely. This is referred to as non-stop mode, with the
5003 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5004 section in the user manual for more information.
5006 To be able to support remote non-stop debugging, a remote stub needs
5007 to implement the non-stop mode remote protocol extensions, as
5008 described in the "Remote Non-Stop" section of the user manual. The
5009 GDB remote stub, gdbserver, has been adjusted to support these
5010 extensions on linux targets.
5012 * New commands (for set/show, see "New options" below)
5014 catch syscall [NAME(S) | NUMBER(S)]
5015 Catch system calls. Arguments, which should be names of system
5016 calls or their numbers, mean catch only those syscalls. Without
5017 arguments, every syscall will be caught. When the inferior issues
5018 any of the specified syscalls, GDB will stop and announce the system
5019 call, both when it is called and when its call returns. This
5020 feature is currently available with a native GDB running on the
5021 Linux Kernel, under the following architectures: x86, x86_64,
5022 PowerPC and PowerPC64.
5024 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5026 Search memory for a sequence of bytes.
5028 maint set python print-stack
5029 maint show python print-stack
5030 Show a stack trace when an error is encountered in a Python script.
5033 Invoke CODE by passing it to the Python interpreter.
5038 These allow macros to be defined, undefined, and listed
5042 Show operating system information about processes.
5045 List the inferiors currently under GDB's control.
5048 Switch focus to inferior number NUM.
5051 Detach from inferior number NUM.
5054 Kill inferior number NUM.
5058 set spu stop-on-load
5059 show spu stop-on-load
5060 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5062 set spu auto-flush-cache
5063 show spu auto-flush-cache
5064 Control whether to automatically flush the software-managed cache
5065 during Cell/B.E. debugging.
5067 set sh calling-convention
5068 show sh calling-convention
5069 Control the calling convention used when calling SH target functions.
5072 show debug timestamp
5073 Control display of timestamps with GDB debugging output.
5075 set disassemble-next-line
5076 show disassemble-next-line
5077 Control display of disassembled source lines or instructions when
5080 set remote noack-packet
5081 show remote noack-packet
5082 Set/show the use of remote protocol QStartNoAckMode packet. See above
5083 under "New remote packets."
5085 set remote query-attached-packet
5086 show remote query-attached-packet
5087 Control use of remote protocol `qAttached' (query-attached) packet.
5089 set remote read-siginfo-object
5090 show remote read-siginfo-object
5091 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5094 set remote write-siginfo-object
5095 show remote write-siginfo-object
5096 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5099 set remote reverse-continue
5100 show remote reverse-continue
5101 Control use of remote protocol 'bc' (reverse-continue) packet.
5103 set remote reverse-step
5104 show remote reverse-step
5105 Control use of remote protocol 'bs' (reverse-step) packet.
5107 set displaced-stepping
5108 show displaced-stepping
5109 Control displaced stepping mode. Displaced stepping is a way to
5110 single-step over breakpoints without removing them from the debuggee.
5111 Also known as "out-of-line single-stepping".
5114 show debug displaced
5115 Control display of debugging info for displaced stepping.
5117 maint set internal-error
5118 maint show internal-error
5119 Control what GDB does when an internal error is detected.
5121 maint set internal-warning
5122 maint show internal-warning
5123 Control what GDB does when an internal warning is detected.
5128 Use a wrapper program to launch programs for debugging.
5130 set multiple-symbols (all|ask|cancel)
5131 show multiple-symbols
5132 The value of this variable can be changed to adjust the debugger behavior
5133 when an expression or a breakpoint location contains an ambiguous symbol
5134 name (an overloaded function name, for instance).
5136 set breakpoint always-inserted
5137 show breakpoint always-inserted
5138 Keep breakpoints always inserted in the target, as opposed to inserting
5139 them when resuming the target, and removing them when the target stops.
5140 This option can improve debugger performance on slow remote targets.
5142 set arm fallback-mode (arm|thumb|auto)
5143 show arm fallback-mode
5144 set arm force-mode (arm|thumb|auto)
5146 These commands control how ARM GDB determines whether instructions
5147 are ARM or Thumb. The default for both settings is auto, which uses
5148 the current CPSR value for instructions without symbols; previous
5149 versions of GDB behaved as if "set arm fallback-mode arm".
5151 set disable-randomization
5152 show disable-randomization
5153 Standalone programs run with the virtual address space randomization enabled
5154 by default on some platforms. This option keeps the addresses stable across
5155 multiple debugging sessions.
5159 Control whether other threads are stopped or not when some thread hits
5164 Requests that asynchronous execution is enabled in the target, if available.
5165 In this case, it's possible to resume target in the background, and interact
5166 with GDB while the target is running. "show target-async" displays the
5167 current state of asynchronous execution of the target.
5169 set target-wide-charset
5170 show target-wide-charset
5171 The target-wide-charset is the name of the character set that GDB
5172 uses when printing characters whose type is wchar_t.
5174 set tcp auto-retry (on|off)
5176 set tcp connect-timeout
5177 show tcp connect-timeout
5178 These commands allow GDB to retry failed TCP connections to a remote stub
5179 with a specified timeout period; this is useful if the stub is launched
5180 in parallel with GDB but may not be ready to accept connections immediately.
5182 set libthread-db-search-path
5183 show libthread-db-search-path
5184 Control list of directories which GDB will search for appropriate
5187 set schedule-multiple (on|off)
5188 show schedule-multiple
5189 Allow GDB to resume all threads of all processes or only threads of
5190 the current process.
5194 Use more aggressive caching for accesses to the stack. This improves
5195 performance of remote debugging (particularly backtraces) without
5196 affecting correctness.
5198 set interactive-mode (on|off|auto)
5199 show interactive-mode
5200 Control whether GDB runs in interactive mode (on) or not (off).
5201 When in interactive mode, GDB waits for the user to answer all
5202 queries. Otherwise, GDB does not wait and assumes the default
5203 answer. When set to auto (the default), GDB determines which
5204 mode to use based on the stdin settings.
5209 For program forks, this is replaced by the new more generic `info
5210 inferiors' command. To list checkpoints, you can still use the
5211 `info checkpoints' command, which was an alias for the `info forks'
5215 Replaced by the new `inferior' command. To switch between
5216 checkpoints, you can still use the `restart' command, which was an
5217 alias for the `fork' command.
5220 This is removed, since some targets don't have a notion of
5221 processes. To switch between processes, you can still use the
5222 `inferior' command using GDB's own inferior number.
5225 For program forks, this is replaced by the new more generic `kill
5226 inferior' command. To delete a checkpoint, you can still use the
5227 `delete checkpoint' command, which was an alias for the `delete
5231 For program forks, this is replaced by the new more generic `detach
5232 inferior' command. To detach a checkpoint, you can still use the
5233 `detach checkpoint' command, which was an alias for the `detach
5236 * New native configurations
5238 x86/x86_64 Darwin i[34567]86-*-darwin*
5240 x86_64 MinGW x86_64-*-mingw*
5244 Lattice Mico32 lm32-*
5245 x86 DICOS i[34567]86-*-dicos*
5246 x86_64 DICOS x86_64-*-dicos*
5249 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5250 (mingw32ce) debugging.
5256 These commands were actually not implemented on any target.
5258 *** Changes in GDB 6.8
5260 * New native configurations
5262 NetBSD/hppa hppa*-*netbsd*
5263 Xtensa GNU/Linux xtensa*-*-linux*
5267 NetBSD/hppa hppa*-*-netbsd*
5268 Xtensa GNU/Linux xtensa*-*-linux*
5270 * Change in command line behavior -- corefiles vs. process ids.
5272 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5273 attaching to process NUMBER fails, GDB no longer attempts to open a
5274 core file named NUMBER. Attaching to a program using the -c option
5275 is no longer supported. Instead, use the '-p' or '--pid' options.
5277 * GDB can now be built as a native debugger for debugging Windows x86
5278 (mingw32) Portable Executable (PE) programs.
5280 * Pending breakpoints no longer change their number when their address
5283 * GDB now supports breakpoints with multiple locations,
5284 including breakpoints on C++ constructors, inside C++ templates,
5285 and in inlined functions.
5287 * GDB's ability to debug optimized code has been improved. GDB more
5288 accurately identifies function bodies and lexical blocks that occupy
5289 more than one contiguous range of addresses.
5291 * Target descriptions can now describe registers for PowerPC.
5293 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5294 registers on PowerPC targets.
5296 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5297 targets even when the libthread_db library is not available.
5299 * The GDB remote stub, gdbserver, now supports the new file transfer
5300 commands (remote put, remote get, and remote delete).
5302 * The GDB remote stub, gdbserver, now supports run and attach in
5303 extended-remote mode.
5305 * hppa*64*-*-hpux11* target broken
5306 The debugger is unable to start a program and fails with the following
5307 error: "Error trying to get information about dynamic linker".
5308 The gdb-6.7 release is also affected.
5310 * GDB now supports the --enable-targets= configure option to allow
5311 building a single GDB executable that supports multiple remote
5312 target architectures.
5314 * GDB now supports debugging C and C++ programs which use the
5315 Decimal Floating Point extension. In addition, the PowerPC target
5316 now has a set of pseudo-registers to inspect decimal float values
5317 stored in two consecutive float registers.
5319 * The -break-insert MI command can optionally create pending
5322 * Improved support for debugging Ada
5323 Many improvements to the Ada language support have been made. These
5325 - Better support for Ada2005 interface types
5326 - Improved handling of arrays and slices in general
5327 - Better support for Taft-amendment types
5328 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5330 - Improved command completion in Ada
5333 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5338 set print frame-arguments (all|scalars|none)
5339 show print frame-arguments
5340 The value of this variable can be changed to control which argument
5341 values should be printed by the debugger when displaying a frame.
5346 Transfer files to and from a remote target, and delete remote files.
5353 Transfer files to and from a remote target, and delete remote files.
5355 * New remote packets
5362 Open, close, read, write, and delete files on the remote system.
5365 Attach to an existing process on the remote system, in extended-remote
5369 Run a new process on the remote system, in extended-remote mode.
5371 *** Changes in GDB 6.7
5373 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5374 bfd, libiberty and opcodes, as revealed by static analysis donated by
5375 Coverity, Inc. (http://scan.coverity.com).
5377 * When looking up multiply-defined global symbols, GDB will now prefer the
5378 symbol definition in the current shared library if it was built using the
5379 -Bsymbolic linker option.
5381 * When the Text User Interface (TUI) is not configured, GDB will now
5382 recognize the -tui command-line option and print a message that the TUI
5385 * The GDB remote stub, gdbserver, now has lower overhead for high
5386 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5388 * GDB for MIPS targets now autodetects whether a remote target provides
5389 32-bit or 64-bit register values.
5391 * Support for C++ member pointers has been improved.
5393 * GDB now understands XML target descriptions, which specify the
5394 target's overall architecture. GDB can read a description from
5395 a local file or over the remote serial protocol.
5397 * Vectors of single-byte data use a new integer type which is not
5398 automatically displayed as character or string data.
5400 * The /s format now works with the print command. It displays
5401 arrays of single-byte integers and pointers to single-byte integers
5404 * Target descriptions can now describe target-specific registers,
5405 for architectures which have implemented the support (currently
5406 only ARM, M68K, and MIPS).
5408 * GDB and the GDB remote stub, gdbserver, now support the XScale
5411 * The GDB remote stub, gdbserver, has been updated to support
5412 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5413 has been rewritten to use the standard GDB remote protocol.
5415 * GDB can now step into C++ functions which are called through thunks.
5417 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5419 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5420 layout. It also supports a TextSeg= and DataSeg= response when only
5421 segment base addresses (rather than offsets) are available.
5423 * The /i format now outputs any trailing branch delay slot instructions
5424 immediately following the last instruction within the count specified.
5426 * The GDB remote protocol "T" stop reply packet now supports a
5427 "library" response. Combined with the new "qXfer:libraries:read"
5428 packet, this response allows GDB to debug shared libraries on targets
5429 where the operating system manages the list of loaded libraries (e.g.
5430 Windows and SymbianOS).
5432 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5433 (DLLs) on Windows and Windows CE targets.
5435 * GDB now supports a faster verification that a .debug file matches its binary
5436 according to its build-id signature, if the signature is present.
5442 Enable or disable hardware flow control (RTS/CTS) on the serial port
5443 when debugging using remote targets.
5445 set mem inaccessible-by-default
5446 show mem inaccessible-by-default
5447 If the target supplies a memory map, for instance via the remote
5448 protocol's "qXfer:memory-map:read" packet, setting this variable
5449 prevents GDB from accessing memory outside the memory map. This
5450 is useful for targets with memory mapped registers or which react
5451 badly to accesses of unmapped address space.
5453 set breakpoint auto-hw
5454 show breakpoint auto-hw
5455 If the target supplies a memory map, for instance via the remote
5456 protocol's "qXfer:memory-map:read" packet, setting this variable
5457 lets GDB use hardware breakpoints automatically for memory regions
5458 where it can not use software breakpoints. This covers both the
5459 "break" command and internal breakpoints used for other commands
5460 including "next" and "finish".
5463 catch exception unhandled
5464 Stop the program execution when Ada exceptions are raised.
5467 Stop the program execution when an Ada assertion failed.
5471 Set an alternate system root for target files. This is a more
5472 general version of "set solib-absolute-prefix", which is now
5473 an alias to "set sysroot".
5476 Provide extended SPU facility status information. This set of
5477 commands is available only when debugging the Cell/B.E. SPU
5480 * New native configurations
5482 OpenBSD/sh sh*-*openbsd*
5485 unset tdesc filename
5487 Use the specified local file as an XML target description, and do
5488 not query the target for its built-in description.
5492 OpenBSD/sh sh*-*-openbsd*
5493 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5494 Toshiba Media Processor mep-elf
5496 * New remote packets
5499 Ignore the specified signals; pass them directly to the debugged program
5500 without stopping other threads or reporting them to GDB.
5502 qXfer:features:read:
5503 Read an XML target description from the target, which describes its
5508 Read or write contents of an spufs file on the target system. These
5509 packets are available only on the Cell/B.E. SPU architecture.
5511 qXfer:libraries:read:
5512 Report the loaded shared libraries. Combined with new "T" packet
5513 response, this packet allows GDB to debug shared libraries on
5514 targets where the operating system manages the list of loaded
5515 libraries (e.g. Windows and SymbianOS).
5519 Support for these obsolete configurations has been removed.
5527 i[34567]86-*-lynxos*
5528 i[34567]86-*-netware*
5529 i[34567]86-*-sco3.2v5*
5530 i[34567]86-*-sco3.2v4*
5532 i[34567]86-*-sysv4.2*
5535 i[34567]86-*-unixware2*
5536 i[34567]86-*-unixware*
5545 * Other removed features
5552 Various m68k-only ROM monitors.
5559 Various Renesas ROM monitors and debugging interfaces for SH and
5564 Support for a Macraigor serial interface to on-chip debugging.
5565 GDB does not directly support the newer parallel or USB
5570 A debug information format. The predecessor to DWARF 2 and
5571 DWARF 3, which are still supported.
5573 Support for the HP aCC compiler on HP-UX/PA-RISC
5575 SOM-encapsulated symbolic debugging information, automatic
5576 invocation of pxdb, and the aCC custom C++ ABI. This does not
5577 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5578 with aCC can still be debugged on an assembly level.
5580 MIPS ".pdr" sections
5582 A MIPS-specific format used to describe stack frame layout
5583 in debugging information.
5587 GDB could work with an older version of Guile to debug
5588 the interpreter and Scheme programs running in it.
5590 set mips stack-arg-size
5591 set mips saved-gpreg-size
5593 Use "set mips abi" to control parameter passing for MIPS.
5595 *** Changes in GDB 6.6
5600 Cell Broadband Engine SPU spu-elf
5602 * GDB can now be configured as a cross-debugger targeting native Windows
5603 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5604 running on a Windows system over TCP/IP to debug Windows programs.
5606 * The GDB remote stub, gdbserver, has been updated to support Windows and
5607 Cygwin debugging. Both single-threaded and multi-threaded programs are
5610 * The "set trust-readonly-sections" command works again. This command was
5611 broken in GDB 6.3, 6.4, and 6.5.
5613 * The "load" command now supports writing to flash memory, if the remote
5614 stub provides the required support.
5616 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5617 longer requires symbolic debug information (e.g. DWARF-2).
5622 unset substitute-path
5623 show substitute-path
5624 Manage a list of substitution rules that GDB uses to rewrite the name
5625 of the directories where the sources are located. This can be useful
5626 for instance when the sources were moved to a different location
5627 between compilation and debugging.
5631 Print each CLI command as it is executed. Each command is prefixed with
5632 a number of `+' symbols representing the nesting depth.
5633 The source command now has a `-v' option to enable the same feature.
5637 The ARM Demon monitor support (RDP protocol, "target rdp").
5639 Kernel Object Display, an embedded debugging feature which only worked with
5640 an obsolete version of Cisco IOS.
5642 The 'set download-write-size' and 'show download-write-size' commands.
5644 * New remote packets
5647 Tell a stub about GDB client features, and request remote target features.
5648 The first feature implemented is PacketSize, which allows the target to
5649 specify the size of packets it can handle - to minimize the number of
5650 packets required and improve performance when connected to a remote
5654 Fetch an OS auxilliary vector from the remote stub. This packet is a
5655 more efficient replacement for qPart:auxv:read.
5657 qXfer:memory-map:read:
5658 Fetch a memory map from the remote stub, including information about
5659 RAM, ROM, and flash memory devices.
5664 Erase and program a flash memory device.
5666 * Removed remote packets
5669 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5670 used it, and only gdbserver implemented it.
5672 *** Changes in GDB 6.5
5676 Renesas M32C/M16C m32c-elf
5678 Morpho Technologies ms1 ms1-elf
5682 init-if-undefined Initialize a convenience variable, but
5683 only if it doesn't already have a value.
5685 The following commands are presently only implemented for native GNU/Linux:
5687 checkpoint Save a snapshot of the program state.
5689 restart <n> Return the program state to a
5690 previously saved state.
5692 info checkpoints List currently saved checkpoints.
5694 delete-checkpoint <n> Delete a previously saved checkpoint.
5696 set|show detach-on-fork Tell gdb whether to detach from a newly
5697 forked process, or to keep debugging it.
5699 info forks List forks of the user program that
5700 are available to be debugged.
5702 fork <n> Switch to debugging one of several
5703 forks of the user program that are
5704 available to be debugged.
5706 delete-fork <n> Delete a fork from the list of forks
5707 that are available to be debugged (and
5708 kill the forked process).
5710 detach-fork <n> Delete a fork from the list of forks
5711 that are available to be debugged (and
5712 allow the process to continue).
5716 Morpho Technologies ms2 ms1-elf
5718 * Improved Windows host support
5720 GDB now builds as a cross debugger hosted on i686-mingw32, including
5721 native console support, and remote communications using either
5722 network sockets or serial ports.
5724 * Improved Modula-2 language support
5726 GDB can now print most types in the Modula-2 syntax. This includes:
5727 basic types, set types, record types, enumerated types, range types,
5728 pointer types and ARRAY types. Procedure var parameters are correctly
5729 printed and hexadecimal addresses and character constants are also
5730 written in the Modula-2 syntax. Best results can be obtained by using
5731 GNU Modula-2 together with the -gdwarf-2 command line option.
5735 The ARM rdi-share module.
5737 The Netware NLM debug server.
5739 *** Changes in GDB 6.4
5741 * New native configurations
5743 OpenBSD/arm arm*-*-openbsd*
5744 OpenBSD/mips64 mips64-*-openbsd*
5748 Morpho Technologies ms1 ms1-elf
5750 * New command line options
5752 --batch-silent As for --batch, but totally silent.
5753 --return-child-result The debugger will exist with the same value
5754 the child (debugged) program exited with.
5755 --eval-command COMMAND, -ex COMMAND
5756 Execute a single GDB CLI command. This may be
5757 specified multiple times and in conjunction
5758 with the --command (-x) option.
5760 * Deprecated commands removed
5762 The following commands, that were deprecated in 2000, have been
5766 set|show arm disassembly-flavor set|show arm disassembler
5767 othernames set arm disassembler
5768 set|show remotedebug set|show debug remote
5769 set|show archdebug set|show debug arch
5770 set|show eventdebug set|show debug event
5773 * New BSD user-level threads support
5775 It is now possible to debug programs using the user-level threads
5776 library on OpenBSD and FreeBSD. Currently supported (target)
5779 FreeBSD/amd64 x86_64-*-freebsd*
5780 FreeBSD/i386 i386-*-freebsd*
5781 OpenBSD/i386 i386-*-openbsd*
5783 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5784 are not yet supported.
5786 * New support for Matsushita MN10300 w/sim added
5787 (Work in progress). mn10300-elf.
5789 * REMOVED configurations and files
5791 VxWorks and the XDR protocol *-*-vxworks
5792 Motorola MCORE mcore-*-*
5793 National Semiconductor NS32000 ns32k-*-*
5795 * New "set print array-indexes" command
5797 After turning this setting "on", GDB prints the index of each element
5798 when displaying arrays. The default is "off" to preserve the previous
5801 * VAX floating point support
5803 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5805 * User-defined command support
5807 In addition to using $arg0..$arg9 for argument passing, it is now possible
5808 to use $argc to determine now many arguments have been passed. See the
5809 section on user-defined commands in the user manual for more information.
5811 *** Changes in GDB 6.3:
5813 * New command line option
5815 GDB now accepts -l followed by a number to set the timeout for remote
5818 * GDB works with GCC -feliminate-dwarf2-dups
5820 GDB now supports a more compact representation of DWARF-2 debug
5821 information using DW_FORM_ref_addr references. These are produced
5822 by GCC with the option -feliminate-dwarf2-dups and also by some
5823 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5824 to use -feliminate-dwarf2-dups.
5826 * Internationalization
5828 When supported by the host system, GDB will be built with
5829 internationalization (libintl). The task of marking up the sources is
5830 continued, we're looking forward to our first translation.
5834 Initial support for debugging programs compiled with the GNAT
5835 implementation of the Ada programming language has been integrated
5836 into GDB. In this release, support is limited to expression evaluation.
5838 * New native configurations
5840 GNU/Linux/m32r m32r-*-linux-gnu
5844 GDB's remote protocol now includes support for the 'p' packet. This
5845 packet is used to fetch individual registers from a remote inferior.
5847 * END-OF-LIFE registers[] compatibility module
5849 GDB's internal register infrastructure has been completely rewritten.
5850 The new infrastructure making possible the implementation of key new
5851 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5854 GDB 6.3 will be the last release to include the registers[]
5855 compatibility module that allowed out-of-date configurations to
5856 continue to work. This change directly impacts the following
5866 powerpc bdm protocol
5868 Unless there is activity to revive these configurations, they will be
5869 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5871 * OBSOLETE configurations and files
5873 Configurations that have been declared obsolete in this release have
5874 been commented out. Unless there is activity to revive these
5875 configurations, the next release of GDB will have their sources
5876 permanently REMOVED.
5885 *** Changes in GDB 6.2.1:
5887 * MIPS `break main; run' gave an heuristic-fence-post warning
5889 When attempting to run even a simple program, a warning about
5890 heuristic-fence-post being hit would be reported. This problem has
5893 * MIPS IRIX 'long double' crashed GDB
5895 When examining a long double variable, GDB would get a segmentation
5896 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5897 IRIX long double values).
5901 A bug in the VAX stack code was causing problems with the "next"
5902 command. This problem has been fixed.
5904 *** Changes in GDB 6.2:
5906 * Fix for ``many threads''
5908 On GNU/Linux systems that use the NPTL threads library, a program
5909 rapidly creating and deleting threads would confuse GDB leading to the
5912 ptrace: No such process.
5913 thread_db_get_info: cannot get thread info: generic error
5915 This problem has been fixed.
5917 * "-async" and "-noasync" options removed.
5919 Support for the broken "-noasync" option has been removed (it caused
5922 * New ``start'' command.
5924 This command runs the program until the beginning of the main procedure.
5926 * New BSD Kernel Data Access Library (libkvm) interface
5928 Using ``target kvm'' it is now possible to debug kernel core dumps and
5929 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5930 platforms. Currently supported (native-only) configurations are:
5932 FreeBSD/amd64 x86_64-*-freebsd*
5933 FreeBSD/i386 i?86-*-freebsd*
5934 NetBSD/i386 i?86-*-netbsd*
5935 NetBSD/m68k m68*-*-netbsd*
5936 NetBSD/sparc sparc-*-netbsd*
5937 OpenBSD/amd64 x86_64-*-openbsd*
5938 OpenBSD/i386 i?86-*-openbsd*
5939 OpenBSD/m68k m68*-openbsd*
5940 OpenBSD/sparc sparc-*-openbsd*
5942 * Signal trampoline code overhauled
5944 Many generic problems with GDB's signal handling code have been fixed.
5945 These include: backtraces through non-contiguous stacks; recognition
5946 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5947 call; backtrace through a signal trampoline; step into and out of
5948 signal handlers; and single-stepping in the signal trampoline.
5950 Please note that kernel bugs are a limiting factor here. These
5951 features have been shown to work on an s390 GNU/Linux system that
5952 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5954 * Cygwin support for DWARF 2 added.
5956 * New native configurations
5958 GNU/Linux/hppa hppa*-*-linux*
5959 OpenBSD/hppa hppa*-*-openbsd*
5960 OpenBSD/m68k m68*-*-openbsd*
5961 OpenBSD/m88k m88*-*-openbsd*
5962 OpenBSD/powerpc powerpc-*-openbsd*
5963 NetBSD/vax vax-*-netbsd*
5964 OpenBSD/vax vax-*-openbsd*
5966 * END-OF-LIFE frame compatibility module
5968 GDB's internal frame infrastructure has been completely rewritten.
5969 The new infrastructure making it possible to support key new features
5970 including DWARF 2 Call Frame Information. To aid in the task of
5971 migrating old configurations to this new infrastructure, a
5972 compatibility module, that allowed old configurations to continue to
5973 work, was also included.
5975 GDB 6.2 will be the last release to include this frame compatibility
5976 module. This change directly impacts the following configurations:
5986 Unless there is activity to revive these configurations, they will be
5987 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5989 * REMOVED configurations and files
5991 Sun 3, running SunOS 3 m68*-*-sunos3*
5992 Sun 3, running SunOS 4 m68*-*-sunos4*
5993 Sun 2, running SunOS 3 m68000-*-sunos3*
5994 Sun 2, running SunOS 4 m68000-*-sunos4*
5995 Motorola 680x0 running LynxOS m68*-*-lynxos*
5996 AT&T 3b1/Unix pc m68*-att-*
5997 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5998 decstation mips-dec-* mips-little-*
5999 riscos mips-*-riscos* mips-*-sysv*
6000 sonymips mips-sony-*
6001 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6003 *** Changes in GDB 6.1.1:
6005 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6007 The TUI (Text-mode User Interface) is now built as part of a default
6008 GDB configuration. It is enabled by either selecting the TUI with the
6009 command line option "-i=tui" or by running the separate "gdbtui"
6010 program. For more information on the TUI, see the manual "Debugging
6013 * Pending breakpoint support (also included in GDB 6.1)
6015 Support has been added to allow you to specify breakpoints in shared
6016 libraries that have not yet been loaded. If a breakpoint location
6017 cannot be found, and the "breakpoint pending" option is set to auto,
6018 GDB queries you if you wish to make the breakpoint pending on a future
6019 shared-library load. If and when GDB resolves the breakpoint symbol,
6020 the pending breakpoint is removed as one or more regular breakpoints
6023 Pending breakpoints are very useful for GCJ Java debugging.
6025 * Fixed ISO-C build problems
6027 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6028 non ISO-C code that stopped them being built using a more strict ISO-C
6029 compiler (e.g., IBM's C compiler).
6031 * Fixed build problem on IRIX 5
6033 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6034 wasn't able to compile compile on an IRIX 5 system.
6036 * Added execute permission to gdb/gdbserver/configure
6038 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6039 permission. This bug would cause configure to fail on a number of
6040 systems (Solaris, IRIX). Ref: server/519.
6042 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6044 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6045 has been updated to use constant array sizes.
6047 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6049 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6050 its generated DWARF Call Frame Info. This encoding was causing GDB to
6051 panic, that panic has been fixed. Ref: gdb/1628.
6053 * Fixed a problem when examining parameters in shared library code.
6055 When examining parameters in optimized shared library code generated
6056 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6057 not available''. GDB now correctly displays the variable's value.
6059 *** Changes in GDB 6.1:
6061 * Removed --with-mmalloc
6063 Support for the mmalloc memory manager has been removed, as it
6064 conflicted with the internal gdb byte cache.
6066 * Changes in AMD64 configurations
6068 The AMD64 target now includes the %cs and %ss registers. As a result
6069 the AMD64 remote protocol has changed; this affects the floating-point
6070 and SSE registers. If you rely on those registers for your debugging,
6071 you should upgrade gdbserver on the remote side.
6073 * Revised SPARC target
6075 The SPARC target has been completely revised, incorporating the
6076 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6077 support for LynxOS and SunOS 4 has been dropped. Calling functions
6078 from within GDB on operating systems with a non-executable stack
6079 (Solaris, OpenBSD) now works.
6083 GDB has a new C++ demangler which does a better job on the mangled
6084 names generated by current versions of g++. It also runs faster, so
6085 with this and other changes gdb should now start faster on large C++
6088 * DWARF 2 Location Expressions
6090 GDB support for location expressions has been extended to support function
6091 arguments and frame bases. Older versions of GDB could crash when they
6094 * C++ nested types and namespaces
6096 GDB's support for nested types and namespaces in C++ has been
6097 improved, especially if you use the DWARF 2 debugging format. (This
6098 is the default for recent versions of GCC on most platforms.)
6099 Specifically, if you have a class "Inner" defined within a class or
6100 namespace "Outer", then GDB realizes that the class's name is
6101 "Outer::Inner", not simply "Inner". This should greatly reduce the
6102 frequency of complaints about not finding RTTI symbols. In addition,
6103 if you are stopped at inside of a function defined within a namespace,
6104 GDB modifies its name lookup accordingly.
6106 * New native configurations
6108 NetBSD/amd64 x86_64-*-netbsd*
6109 OpenBSD/amd64 x86_64-*-openbsd*
6110 OpenBSD/alpha alpha*-*-openbsd*
6111 OpenBSD/sparc sparc-*-openbsd*
6112 OpenBSD/sparc64 sparc64-*-openbsd*
6114 * New debugging protocols
6116 M32R with SDI protocol m32r-*-elf*
6118 * "set prompt-escape-char" command deleted.
6120 The command "set prompt-escape-char" has been deleted. This command,
6121 and its very obscure effect on GDB's prompt, was never documented,
6122 tested, nor mentioned in the NEWS file.
6124 * OBSOLETE configurations and files
6126 Configurations that have been declared obsolete in this release have
6127 been commented out. Unless there is activity to revive these
6128 configurations, the next release of GDB will have their sources
6129 permanently REMOVED.
6131 Sun 3, running SunOS 3 m68*-*-sunos3*
6132 Sun 3, running SunOS 4 m68*-*-sunos4*
6133 Sun 2, running SunOS 3 m68000-*-sunos3*
6134 Sun 2, running SunOS 4 m68000-*-sunos4*
6135 Motorola 680x0 running LynxOS m68*-*-lynxos*
6136 AT&T 3b1/Unix pc m68*-att-*
6137 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6138 decstation mips-dec-* mips-little-*
6139 riscos mips-*-riscos* mips-*-sysv*
6140 sonymips mips-sony-*
6141 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6143 * REMOVED configurations and files
6145 SGI Irix-4.x mips-sgi-irix4 or iris4
6146 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6147 Z8000 simulator z8k-zilog-none or z8ksim
6148 Matsushita MN10200 w/simulator mn10200-*-*
6149 H8/500 simulator h8500-hitachi-hms or h8500hms
6150 HP/PA running BSD hppa*-*-bsd*
6151 HP/PA running OSF/1 hppa*-*-osf*
6152 HP/PA Pro target hppa*-*-pro*
6153 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6154 386BSD i[3456]86-*-bsd*
6155 Sequent family i[3456]86-sequent-sysv4*
6156 i[3456]86-sequent-sysv*
6157 i[3456]86-sequent-bsd*
6158 SPARC running LynxOS sparc-*-lynxos*
6159 SPARC running SunOS 4 sparc-*-sunos4*
6160 Tsqware Sparclet sparclet-*-*
6161 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6163 *** Changes in GDB 6.0:
6167 Support for debugging the Objective-C programming language has been
6168 integrated into GDB.
6170 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6172 DWARF 2's Call Frame Information makes available compiler generated
6173 information that more exactly describes the program's run-time stack.
6174 By using this information, GDB is able to provide more robust stack
6177 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6178 have been updated to use a new backtrace mechanism which includes
6179 DWARF 2 CFI support.
6183 GDB's remote protocol has been extended to include support for hosted
6184 file I/O (where the remote target uses GDB's file system). See GDB's
6185 remote protocol documentation for details.
6187 * All targets using the new architecture framework.
6189 All of GDB's targets have been updated to use the new internal
6190 architecture framework. The way is now open for future GDB releases
6191 to include cross-architecture native debugging support (i386 on amd64,
6194 * GNU/Linux's Thread Local Storage (TLS)
6196 GDB now includes support for for the GNU/Linux implementation of
6197 per-thread variables.
6199 * GNU/Linux's Native POSIX Thread Library (NPTL)
6201 GDB's thread code has been updated to work with either the new
6202 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6204 * Separate debug info.
6206 GDB, in conjunction with BINUTILS, now supports a mechanism for
6207 automatically loading debug information from a separate file. Instead
6208 of shipping full debug and non-debug versions of system libraries,
6209 system integrators can now instead ship just the stripped libraries
6210 and optional debug files.
6212 * DWARF 2 Location Expressions
6214 DWARF 2 Location Expressions allow the compiler to more completely
6215 describe the location of variables (even in optimized code) to the
6218 GDB now includes preliminary support for location expressions (support
6219 for DW_OP_piece is still missing).
6223 A number of long standing bugs that caused GDB to die while starting a
6224 Java application have been fixed. GDB's Java support is now
6225 considered "useable".
6227 * GNU/Linux support for fork, vfork, and exec.
6229 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6230 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6233 * GDB supports logging output to a file
6235 There are two new commands, "set logging" and "show logging", which can be
6236 used to capture GDB's output to a file.
6238 * The meaning of "detach" has changed for gdbserver
6240 The "detach" command will now resume the application, as documented. To
6241 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6244 * d10v, m68hc11 `regs' command deprecated
6246 The `info registers' command has been updated so that it displays the
6247 registers using a format identical to the old `regs' command.
6251 A new command, "maint set profile on/off", has been added. This command can
6252 be used to enable or disable profiling while running GDB, to profile a
6253 session or a set of commands. In addition there is a new configure switch,
6254 "--enable-profiling", which will cause GDB to be compiled with profiling
6255 data, for more informative profiling results.
6257 * Default MI syntax changed to "mi2".
6259 The default MI (machine interface) syntax, enabled by the command line
6260 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6261 "mi1", can be enabled by specifying the option "-i=mi1".
6263 Support for the original "mi0" syntax (included in GDB 5.0) has been
6266 Fix for gdb/192: removed extraneous space when displaying frame level.
6267 Fix for gdb/672: update changelist is now output in mi list format.
6268 Fix for gdb/702: a -var-assign that updates the value now shows up
6269 in a subsequent -var-update.
6271 * New native configurations.
6273 FreeBSD/amd64 x86_64-*-freebsd*
6275 * Multi-arched targets.
6277 HP/PA HPUX11 hppa*-*-hpux*
6278 Renesas M32R/D w/simulator m32r-*-elf*
6280 * OBSOLETE configurations and files
6282 Configurations that have been declared obsolete in this release have
6283 been commented out. Unless there is activity to revive these
6284 configurations, the next release of GDB will have their sources
6285 permanently REMOVED.
6287 Z8000 simulator z8k-zilog-none or z8ksim
6288 Matsushita MN10200 w/simulator mn10200-*-*
6289 H8/500 simulator h8500-hitachi-hms or h8500hms
6290 HP/PA running BSD hppa*-*-bsd*
6291 HP/PA running OSF/1 hppa*-*-osf*
6292 HP/PA Pro target hppa*-*-pro*
6293 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6294 Sequent family i[3456]86-sequent-sysv4*
6295 i[3456]86-sequent-sysv*
6296 i[3456]86-sequent-bsd*
6297 Tsqware Sparclet sparclet-*-*
6298 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6300 * REMOVED configurations and files
6303 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6304 IBM AIX PS/2 i[3456]86-*-aix
6305 i386 running Mach 3.0 i[3456]86-*-mach3*
6306 i386 running Mach i[3456]86-*-mach*
6307 i386 running OSF/1 i[3456]86-*osf1mk*
6308 HP/Apollo 68k Family m68*-apollo*-sysv*,
6310 m68*-hp-bsd*, m68*-hp-hpux*
6311 Argonaut Risc Chip (ARC) arc-*-*
6312 Mitsubishi D30V d30v-*-*
6313 Fujitsu FR30 fr30-*-elf*
6314 OS/9000 i[34]86-*-os9k
6315 I960 with MON960 i960-*-coff
6317 * MIPS $fp behavior changed
6319 The convenience variable $fp, for the MIPS, now consistently returns
6320 the address of the current frame's base. Previously, depending on the
6321 context, $fp could refer to either $sp or the current frame's base
6322 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6323 The GNU Source-Level Debugger''.
6325 *** Changes in GDB 5.3:
6327 * GNU/Linux shared library multi-threaded performance improved.
6329 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6330 `/proc', in preference to `ptrace' for memory reads. This may result
6331 in an improvement in the start-up time of multi-threaded, shared
6332 library applications when run under GDB. One GDB user writes: ``loads
6333 shared libs like mad''.
6335 * ``gdbserver'' now supports multi-threaded applications on some targets
6337 Support for debugging multi-threaded applications which use
6338 the GNU/Linux LinuxThreads package has been added for
6339 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6340 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6342 * GDB now supports C/C++ preprocessor macros.
6344 GDB now expands preprocessor macro invocations in C/C++ expressions,
6345 and provides various commands for showing macro definitions and how
6348 The new command `macro expand EXPRESSION' expands any macro
6349 invocations in expression, and shows the result.
6351 The new command `show macro MACRO-NAME' shows the definition of the
6352 macro named MACRO-NAME, and where it was defined.
6354 Most compilers don't include information about macros in the debugging
6355 information by default. In GCC 3.1, for example, you need to compile
6356 your program with the options `-gdwarf-2 -g3'. If the macro
6357 information is present in the executable, GDB will read it.
6359 * Multi-arched targets.
6361 DEC Alpha (partial) alpha*-*-*
6362 DEC VAX (partial) vax-*-*
6364 National Semiconductor NS32000 (partial) ns32k-*-*
6365 Motorola 68000 (partial) m68k-*-*
6366 Motorola MCORE mcore-*-*
6370 Fujitsu FRV architecture added by Red Hat frv*-*-*
6373 * New native configurations
6375 Alpha NetBSD alpha*-*-netbsd*
6376 SH NetBSD sh*-*-netbsdelf*
6377 MIPS NetBSD mips*-*-netbsd*
6378 UltraSPARC NetBSD sparc64-*-netbsd*
6380 * OBSOLETE configurations and files
6382 Configurations that have been declared obsolete in this release have
6383 been commented out. Unless there is activity to revive these
6384 configurations, the next release of GDB will have their sources
6385 permanently REMOVED.
6387 Mitsubishi D30V d30v-*-*
6388 OS/9000 i[34]86-*-os9k
6389 IBM AIX PS/2 i[3456]86-*-aix
6390 Fujitsu FR30 fr30-*-elf*
6391 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6392 Argonaut Risc Chip (ARC) arc-*-*
6393 i386 running Mach 3.0 i[3456]86-*-mach3*
6394 i386 running Mach i[3456]86-*-mach*
6395 i386 running OSF/1 i[3456]86-*osf1mk*
6396 HP/Apollo 68k Family m68*-apollo*-sysv*,
6398 m68*-hp-bsd*, m68*-hp-hpux*
6399 I960 with MON960 i960-*-coff
6401 * OBSOLETE languages
6403 CHILL, a Pascal like language used by telecommunications companies.
6405 * REMOVED configurations and files
6407 AMD 29k family via UDI a29k-amd-udi, udi29k
6408 A29K VxWorks a29k-*-vxworks
6409 AMD 29000 embedded, using EBMON a29k-none-none
6410 AMD 29000 embedded with COFF a29k-none-coff
6411 AMD 29000 embedded with a.out a29k-none-aout
6413 testsuite/gdb.hp/gdb.threads-hp/ directory
6415 * New command "set max-user-call-depth <nnn>"
6417 This command allows the user to limit the call depth of user-defined
6418 commands. The default is 1024.
6420 * Changes in FreeBSD/i386 native debugging.
6422 Support for the "generate-core-file" has been added.
6424 * New commands "dump", "append", and "restore".
6426 These commands allow data to be copied from target memory
6427 to a bfd-format or binary file (dump and append), and back
6428 from a file into memory (restore).
6430 * Improved "next/step" support on multi-processor Alpha Tru64.
6432 The previous single-step mechanism could cause unpredictable problems,
6433 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6434 of a software single-step mechanism prevents this.
6436 *** Changes in GDB 5.2.1:
6444 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6445 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6446 Fix, by Joel Brobecker imported from mainline.
6448 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6449 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6450 Fix, by Fred Fish, imported from mainline.
6452 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6453 Surprisingly enough, it works now.
6454 By Michal Ludvig, imported from mainline.
6456 i386 hardware watchpoint support:
6457 avoid misses on second run for some targets.
6458 By Pierre Muller, imported from mainline.
6460 *** Changes in GDB 5.2:
6462 * New command "set trust-readonly-sections on[off]".
6464 This command is a hint that tells gdb that read-only sections
6465 really are read-only (ie. that their contents will not change).
6466 In this mode, gdb will go to the object file rather than the
6467 target to read memory from read-only sections (such as ".text").
6468 This can be a significant performance improvement on some
6469 (notably embedded) targets.
6471 * New command "generate-core-file" (or "gcore").
6473 This new gdb command allows the user to drop a core file of the child
6474 process state at any time. So far it's been implemented only for
6475 GNU/Linux and Solaris, but should be relatively easily ported to other
6476 hosts. Argument is core file name (defaults to core.<pid>).
6478 * New command line option
6480 GDB now accepts --pid or -p followed by a process id.
6482 * Change in command line behavior -- corefiles vs. process ids.
6484 There is a subtle behavior in the way in which GDB handles
6485 command line arguments. The first non-flag argument is always
6486 a program to debug, but the second non-flag argument may either
6487 be a corefile or a process id. Previously, GDB would attempt to
6488 open the second argument as a corefile, and if that failed, would
6489 issue a superfluous error message and then attempt to attach it as
6490 a process. Now, if the second argument begins with a non-digit,
6491 it will be treated as a corefile. If it begins with a digit,
6492 GDB will attempt to attach it as a process, and if no such process
6493 is found, will then attempt to open it as a corefile.
6495 * Changes in ARM configurations.
6497 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6498 configuration is fully multi-arch.
6500 * New native configurations
6502 ARM NetBSD arm*-*-netbsd*
6503 x86 OpenBSD i[3456]86-*-openbsd*
6504 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6505 Sparc64 running FreeBSD sparc64-*-freebsd*
6509 Sanyo XStormy16 xstormy16-elf
6511 * OBSOLETE configurations and files
6513 Configurations that have been declared obsolete in this release have
6514 been commented out. Unless there is activity to revive these
6515 configurations, the next release of GDB will have their sources
6516 permanently REMOVED.
6518 AMD 29k family via UDI a29k-amd-udi, udi29k
6519 A29K VxWorks a29k-*-vxworks
6520 AMD 29000 embedded, using EBMON a29k-none-none
6521 AMD 29000 embedded with COFF a29k-none-coff
6522 AMD 29000 embedded with a.out a29k-none-aout
6524 testsuite/gdb.hp/gdb.threads-hp/ directory
6526 * REMOVED configurations and files
6528 TI TMS320C80 tic80-*-*
6530 PowerPC Solaris powerpcle-*-solaris*
6531 PowerPC Windows NT powerpcle-*-cygwin32
6532 PowerPC Netware powerpc-*-netware*
6533 Harris/CXUX m88k m88*-harris-cxux*
6534 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6535 ns32k-utek-sysv* ns32k-utek-*
6536 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6537 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6538 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6539 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6540 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6542 * Changes to command line processing
6544 The new `--args' feature can be used to specify command-line arguments
6545 for the inferior from gdb's command line.
6547 * Changes to key bindings
6549 There is a new `operate-and-get-next' function bound to `C-o'.
6551 *** Changes in GDB 5.1.1
6553 Fix compile problem on DJGPP.
6555 Fix a problem with floating-point registers on the i386 being
6558 Fix to stop GDB crashing on .debug_str debug info.
6560 Numerous documentation fixes.
6562 Numerous testsuite fixes.
6564 *** Changes in GDB 5.1:
6566 * New native configurations
6568 Alpha FreeBSD alpha*-*-freebsd*
6569 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6570 MIPS GNU/Linux mips*-*-linux*
6571 MIPS SGI Irix 6.x mips*-sgi-irix6*
6572 ia64 AIX ia64-*-aix*
6573 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6577 Motorola 68HC11 and 68HC12 m68hc11-elf
6579 UltraSparc running GNU/Linux sparc64-*-linux*
6581 * OBSOLETE configurations and files
6583 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6584 Harris/CXUX m88k m88*-harris-cxux*
6585 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6586 ns32k-utek-sysv* ns32k-utek-*
6587 TI TMS320C80 tic80-*-*
6589 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6590 PowerPC Solaris powerpcle-*-solaris*
6591 PowerPC Windows NT powerpcle-*-cygwin32
6592 PowerPC Netware powerpc-*-netware*
6593 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6594 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6595 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6596 Apple Macintosh (MPW) host N/A
6598 stuff.c (Program to stuff files into a specially prepared space in kdb)
6599 kdb-start.c (Main loop for the standalone kernel debugger)
6601 Configurations that have been declared obsolete in this release have
6602 been commented out. Unless there is activity to revive these
6603 configurations, the next release of GDB will have their sources
6604 permanently REMOVED.
6606 * REMOVED configurations and files
6608 Altos 3068 m68*-altos-*
6609 Convex c1-*-*, c2-*-*
6611 ARM RISCix arm-*-* (as host)
6615 * GDB has been converted to ISO C.
6617 GDB's source code has been converted to ISO C. In particular, the
6618 sources are fully protoized, and rely on standard headers being
6623 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6625 * The MI enabled by default.
6627 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6628 revised and enabled by default. Packages which use GDB as a debugging
6629 engine behind a UI or another front end are encouraged to switch to
6630 using the GDB/MI interface, instead of the old annotations interface
6631 which is now deprecated.
6633 * Support for debugging Pascal programs.
6635 GDB now includes support for debugging Pascal programs. The following
6636 main features are supported:
6638 - Pascal-specific data types such as sets;
6640 - automatic recognition of Pascal sources based on file-name
6643 - Pascal-style display of data types, variables, and functions;
6645 - a Pascal expression parser.
6647 However, some important features are not yet supported.
6649 - Pascal string operations are not supported at all;
6651 - there are some problems with boolean types;
6653 - Pascal type hexadecimal constants are not supported
6654 because they conflict with the internal variables format;
6656 - support for Pascal objects and classes is not full yet;
6658 - unlike Pascal, GDB is case-sensitive for symbol names.
6660 * Changes in completion.
6662 Commands such as `shell', `run' and `set args', which pass arguments
6663 to inferior programs, now complete on file names, similar to what
6664 users expect at the shell prompt.
6666 Commands which accept locations, such as `disassemble', `print',
6667 `breakpoint', `until', etc. now complete on filenames as well as
6668 program symbols. Thus, if you type "break foob TAB", and the source
6669 files linked into the programs include `foobar.c', that file name will
6670 be one of the candidates for completion. However, file names are not
6671 considered for completion after you typed a colon that delimits a file
6672 name from a name of a function in that file, as in "break foo.c:bar".
6674 `set demangle-style' completes on available demangling styles.
6676 * New platform-independent commands:
6678 It is now possible to define a post-hook for a command as well as a
6679 hook that runs before the command. For more details, see the
6680 documentation of `hookpost' in the GDB manual.
6682 * Changes in GNU/Linux native debugging.
6684 Support for debugging multi-threaded programs has been completely
6685 revised for all platforms except m68k and sparc. You can now debug as
6686 many threads as your system allows you to have.
6688 Attach/detach is supported for multi-threaded programs.
6690 Support for SSE registers was added for x86. This doesn't work for
6691 multi-threaded programs though.
6693 * Changes in MIPS configurations.
6695 Multi-arch support is enabled for all MIPS configurations.
6697 GDB can now be built as native debugger on SGI Irix 6.x systems for
6698 debugging n32 executables. (Debugging 64-bit executables is not yet
6701 * Unified support for hardware watchpoints in all x86 configurations.
6703 Most (if not all) native x86 configurations support hardware-assisted
6704 breakpoints and watchpoints in a unified manner. This support
6705 implements debug register sharing between watchpoints, which allows to
6706 put a virtually infinite number of watchpoints on the same address,
6707 and also supports watching regions up to 16 bytes with several debug
6710 The new maintenance command `maintenance show-debug-regs' toggles
6711 debugging print-outs in functions that insert, remove, and test
6712 watchpoints and hardware breakpoints.
6714 * Changes in the DJGPP native configuration.
6716 New command ``info dos sysinfo'' displays assorted information about
6717 the CPU, OS, memory, and DPMI server.
6719 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6720 display information about segment descriptors stored in GDT, LDT, and
6723 New commands ``info dos pde'' and ``info dos pte'' display entries
6724 from Page Directory and Page Tables (for now works with CWSDPMI only).
6725 New command ``info dos address-pte'' displays the Page Table entry for
6726 a given linear address.
6728 GDB can now pass command lines longer than 126 characters to the
6729 program being debugged (requires an update to the libdbg.a library
6730 which is part of the DJGPP development kit).
6732 DWARF2 debug info is now supported.
6734 It is now possible to `step' and `next' through calls to `longjmp'.
6736 * Changes in documentation.
6738 All GDB documentation was converted to GFDL, the GNU Free
6739 Documentation License.
6741 Tracepoints-related commands are now fully documented in the GDB
6744 TUI, the Text-mode User Interface, is now documented in the manual.
6746 Tracepoints-related commands are now fully documented in the GDB
6749 The "GDB Internals" manual now has an index. It also includes
6750 documentation of `ui_out' functions, GDB coding standards, x86
6751 hardware watchpoints, and memory region attributes.
6753 * GDB's version number moved to ``version.in''
6755 The Makefile variable VERSION has been replaced by the file
6756 ``version.in''. People creating GDB distributions should update the
6757 contents of this file.
6761 GUD support is now a standard part of the EMACS distribution.
6763 *** Changes in GDB 5.0:
6765 * Improved support for debugging FP programs on x86 targets
6767 Unified and much-improved support for debugging floating-point
6768 programs on all x86 targets. In particular, ``info float'' now
6769 displays the FP registers in the same format on all x86 targets, with
6770 greater level of detail.
6772 * Improvements and bugfixes in hardware-assisted watchpoints
6774 It is now possible to watch array elements, struct members, and
6775 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6776 on x86 targets no longer erroneously trigger when the address is
6779 * Improvements in the native DJGPP version of GDB
6781 The distribution now includes all the scripts and auxiliary files
6782 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6783 machines ``out of the box''.
6785 The DJGPP version can now debug programs that use signals. It is
6786 possible to catch signals that happened in the debuggee, deliver
6787 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6788 would kill the program being debugged.) Programs that hook hardware
6789 interrupts (keyboard, timer, etc.) can also be debugged.
6791 It is now possible to debug DJGPP programs that redirect their
6792 standard handles or switch them to raw (as opposed to cooked) mode, or
6793 even close them. The command ``run < foo > bar'' works as expected,
6794 and ``info terminal'' reports useful information about the debuggee's
6795 terminal, including raw/cooked mode, redirection, etc.
6797 The DJGPP version now uses termios functions for console I/O, which
6798 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6801 DOS-style file names with drive letters are now fully supported by
6804 It is now possible to debug DJGPP programs that switch their working
6805 directory. It is also possible to rerun the debuggee any number of
6806 times without restarting GDB; thus, you can use the same setup,
6807 breakpoints, etc. for many debugging sessions.
6809 * New native configurations
6811 ARM GNU/Linux arm*-*-linux*
6812 PowerPC GNU/Linux powerpc-*-linux*
6816 Motorola MCore mcore-*-*
6817 x86 VxWorks i[3456]86-*-vxworks*
6818 PowerPC VxWorks powerpc-*-vxworks*
6819 TI TMS320C80 tic80-*-*
6821 * OBSOLETE configurations
6823 Altos 3068 m68*-altos-*
6824 Convex c1-*-*, c2-*-*
6826 ARM RISCix arm-*-* (as host)
6829 Configurations that have been declared obsolete will be commented out,
6830 but the code will be left in place. If there is no activity to revive
6831 these configurations before the next release of GDB, the sources will
6832 be permanently REMOVED.
6834 * Gould support removed
6836 Support for the Gould PowerNode and NP1 has been removed.
6838 * New features for SVR4
6840 On SVR4 native platforms (such as Solaris), if you attach to a process
6841 without first loading a symbol file, GDB will now attempt to locate and
6842 load symbols from the running process's executable file.
6844 * Many C++ enhancements
6846 C++ support has been greatly improved. Overload resolution now works properly
6847 in almost all cases. RTTI support is on the way.
6849 * Remote targets can connect to a sub-program
6851 A popen(3) style serial-device has been added. This device starts a
6852 sub-process (such as a stand-alone simulator) and then communicates
6853 with that. The sub-program to run is specified using the syntax
6854 ``|<program> <args>'' vis:
6856 (gdb) set remotedebug 1
6857 (gdb) target extended-remote |mn10300-elf-sim program-args
6859 * MIPS 64 remote protocol
6861 A long standing bug in the mips64 remote protocol where by GDB
6862 expected certain 32 bit registers (ex SR) to be transfered as 32
6863 instead of 64 bits has been fixed.
6865 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6866 added to provide backward compatibility with older versions of GDB.
6868 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6870 The command ``set remotebinarydownload'' command has been replaced by
6871 ``set remote X-packet''. Other commands in ``set remote'' family
6872 include ``set remote P-packet''.
6874 * Breakpoint commands accept ranges.
6876 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6877 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6878 ``tracepoint passcount'' also accepts a range of tracepoints.
6880 * ``apropos'' command added.
6882 The ``apropos'' command searches through command names and
6883 documentation strings, printing out matches, making it much easier to
6884 try to find a command that does what you are looking for.
6888 A new machine oriented interface (MI) has been added to GDB. This
6889 interface is designed for debug environments running GDB as a separate
6890 process. This is part of the long term libGDB project. See the
6891 "GDB/MI" chapter of the GDB manual for further information. It can be
6892 enabled by configuring with:
6894 .../configure --enable-gdbmi
6896 *** Changes in GDB-4.18:
6898 * New native configurations
6900 HP-UX 10.20 hppa*-*-hpux10.20
6901 HP-UX 11.x hppa*-*-hpux11.0*
6902 M68K GNU/Linux m68*-*-linux*
6906 Fujitsu FR30 fr30-*-elf*
6907 Intel StrongARM strongarm-*-*
6908 Mitsubishi D30V d30v-*-*
6910 * OBSOLETE configurations
6912 Gould PowerNode, NP1 np1-*-*, pn-*-*
6914 Configurations that have been declared obsolete will be commented out,
6915 but the code will be left in place. If there is no activity to revive
6916 these configurations before the next release of GDB, the sources will
6917 be permanently REMOVED.
6921 As a compatibility experiment, GDB's source files buildsym.h and
6922 buildsym.c have been converted to pure standard C, no longer
6923 containing any K&R compatibility code. We believe that all systems in
6924 use today either come with a standard C compiler, or have a GCC port
6925 available. If this is not true, please report the affected
6926 configuration to bug-gdb@gnu.org immediately. See the README file for
6927 information about getting a standard C compiler if you don't have one
6932 GDB now uses readline 2.2.
6934 * set extension-language
6936 You can now control the mapping between filename extensions and source
6937 languages by using the `set extension-language' command. For instance,
6938 you can ask GDB to treat .c files as C++ by saying
6939 set extension-language .c c++
6940 The command `info extensions' lists all of the recognized extensions
6941 and their associated languages.
6943 * Setting processor type for PowerPC and RS/6000
6945 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6946 you can use the `set processor' command to specify what variant of the
6947 PowerPC family you are debugging. The command
6951 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6952 following PowerPC and RS6000 variants:
6954 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6955 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6957 403GC IBM PowerPC 403GC
6958 505 Motorola PowerPC 505
6959 860 Motorola PowerPC 860 or 850
6960 601 Motorola PowerPC 601
6961 602 Motorola PowerPC 602
6962 603 Motorola/IBM PowerPC 603 or 603e
6963 604 Motorola PowerPC 604 or 604e
6964 750 Motorola/IBM PowerPC 750 or 750
6966 At the moment, this command just tells GDB what to name the
6967 special-purpose processor registers. Since almost all the affected
6968 registers are inaccessible to user-level programs, this command is
6969 only useful for remote debugging in its present form.
6973 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6974 more extensive support for HP-UX. Added features include shared
6975 library support, kernel threads and hardware watchpoints for 11.00,
6976 support for HP's ANSI C and C++ compilers, and a compatibility mode
6977 for xdb and dbx commands.
6981 HP's donation includes the new concept of catchpoints, which is a
6982 generalization of the old catch command. On HP-UX, it is now possible
6983 to catch exec, fork, and vfork, as well as library loading.
6985 This means that the existing catch command has changed; its first
6986 argument now specifies the type of catch to be set up. See the
6987 output of "help catch" for a list of catchpoint types.
6989 * Debugging across forks
6991 On HP-UX, you can choose which process to debug when a fork() happens
6996 HP has donated a curses-based terminal user interface (TUI). To get
6997 it, build with --enable-tui. Although this can be enabled for any
6998 configuration, at present it only works for native HP debugging.
7000 * GDB remote protocol additions
7002 A new protocol packet 'X' that writes binary data is now available.
7003 Default behavior is to try 'X', then drop back to 'M' if the stub
7004 fails to respond. The settable variable `remotebinarydownload'
7005 allows explicit control over the use of 'X'.
7007 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7008 full 64-bit address. The command
7010 set remoteaddresssize 32
7012 can be used to revert to the old behaviour. For existing remote stubs
7013 the change should not be noticed, as the additional address information
7016 In order to assist in debugging stubs, you may use the maintenance
7017 command `packet' to send any text string to the stub. For instance,
7019 maint packet heythere
7021 sends the packet "$heythere#<checksum>". Note that it is very easy to
7022 disrupt a debugging session by sending the wrong packet at the wrong
7025 The compare-sections command allows you to compare section data on the
7026 target to what is in the executable file without uploading or
7027 downloading, by comparing CRC checksums.
7029 * Tracing can collect general expressions
7031 You may now collect general expressions at tracepoints. This requires
7032 further additions to the target-side stub; see tracepoint.c and
7033 doc/agentexpr.texi for further details.
7035 * mask-address variable for Mips
7037 For Mips targets, you may control the zeroing of the upper 32 bits of
7038 a 64-bit address by entering `set mask-address on'. This is mainly
7039 of interest to users of embedded R4xxx and R5xxx processors.
7041 * Higher serial baud rates
7043 GDB's serial code now allows you to specify baud rates 57600, 115200,
7044 230400, and 460800 baud. (Note that your host system may not be able
7045 to achieve all of these rates.)
7049 The i960 configuration now includes an initial implementation of a
7050 builtin simulator, contributed by Jim Wilson.
7053 *** Changes in GDB-4.17:
7055 * New native configurations
7057 Alpha GNU/Linux alpha*-*-linux*
7058 Unixware 2.x i[3456]86-unixware2*
7059 Irix 6.x mips*-sgi-irix6*
7060 PowerPC GNU/Linux powerpc-*-linux*
7061 PowerPC Solaris powerpcle-*-solaris*
7062 Sparc GNU/Linux sparc-*-linux*
7063 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7067 Argonaut Risc Chip (ARC) arc-*-*
7068 Hitachi H8/300S h8300*-*-*
7069 Matsushita MN10200 w/simulator mn10200-*-*
7070 Matsushita MN10300 w/simulator mn10300-*-*
7071 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7072 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7073 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7074 Mitsubishi D10V w/simulator d10v-*-*
7075 Mitsubishi M32R/D w/simulator m32r-*-elf*
7076 Tsqware Sparclet sparclet-*-*
7077 NEC V850 w/simulator v850-*-*
7079 * New debugging protocols
7081 ARM with RDI protocol arm*-*-*
7082 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7083 DDB and LSI variants of PMON protocol mips*-*-*
7084 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7085 PowerPC with SDS protocol powerpc{,le}-*-eabi
7086 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7090 All configurations can now understand and use the DWARF 2 debugging
7091 format. The choice is automatic, if the symbol file contains DWARF 2
7096 GDB now includes basic Java language support. This support is
7097 only useful with Java compilers that produce native machine code.
7099 * solib-absolute-prefix and solib-search-path
7101 For SunOS and SVR4 shared libraries, you may now set the prefix for
7102 loading absolute shared library symbol files, and the search path for
7103 locating non-absolute shared library symbol files.
7105 * Live range splitting
7107 GDB can now effectively debug code for which GCC has performed live
7108 range splitting as part of its optimization. See gdb/doc/LRS for
7109 more details on the expected format of the stabs information.
7113 GDB's support for the GNU Hurd, including thread debugging, has been
7114 updated to work with current versions of the Hurd.
7118 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7119 instruction set. ARM GDB automatically detects when Thumb
7120 instructions are in use, and adjusts disassembly and backtracing
7125 GDB's MIPS target configurations now handle the MIP16 16-bit
7130 GDB now includes support for overlays; if an executable has been
7131 linked such that multiple sections are based at the same address, GDB
7132 will decide which section to use for symbolic info. You can choose to
7133 control the decision manually, using overlay commands, or implement
7134 additional target-side support and use "overlay load-target" to bring
7135 in the overlay mapping. Do "help overlay" for more detail.
7139 The command "info symbol <address>" displays information about
7140 the symbol at the specified address.
7144 The standard remote protocol now includes an extension that allows
7145 asynchronous collection and display of trace data. This requires
7146 extensive support in the target-side debugging stub. Tracing mode
7147 includes a new interaction mode in GDB and new commands: see the
7148 file tracepoint.c for more details.
7152 Configurations for embedded MIPS now include a simulator contributed
7153 by Cygnus Solutions. The simulator supports the instruction sets
7154 of most MIPS variants.
7158 Sparc configurations may now include the ERC32 simulator contributed
7159 by the European Space Agency. The simulator is not built into
7160 Sparc targets by default; configure with --enable-sim to include it.
7164 For target configurations that may include multiple variants of a
7165 basic architecture (such as MIPS and SH), you may now set the
7166 architecture explicitly. "set arch" sets, "info arch" lists
7167 the possible architectures.
7169 *** Changes in GDB-4.16:
7171 * New native configurations
7173 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7174 M68K NetBSD m68k-*-netbsd*
7175 PowerPC AIX 4.x powerpc-*-aix*
7176 PowerPC MacOS powerpc-*-macos*
7177 PowerPC Windows NT powerpcle-*-cygwin32
7178 RS/6000 AIX 4.x rs6000-*-aix4*
7182 ARM with RDP protocol arm-*-*
7183 I960 with MON960 i960-*-coff
7184 MIPS VxWorks mips*-*-vxworks*
7185 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7186 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7188 Matra Sparclet sparclet-*-*
7192 The powerpc-eabi configuration now includes the PSIM simulator,
7193 contributed by Andrew Cagney, with assistance from Mike Meissner.
7194 PSIM is a very elaborate model of the PowerPC, including not only
7195 basic instruction set execution, but also details of execution unit
7196 performance and I/O hardware. See sim/ppc/README for more details.
7200 GDB now works with Solaris 2.5.
7202 * Windows 95/NT native
7204 GDB will now work as a native debugger on Windows 95 and Windows NT.
7205 To build it from source, you must use the "gnu-win32" environment,
7206 which uses a DLL to emulate enough of Unix to run the GNU tools.
7207 Further information, binaries, and sources are available at
7208 ftp.cygnus.com, under pub/gnu-win32.
7210 * dont-repeat command
7212 If a user-defined command includes the command `dont-repeat', then the
7213 command will not be repeated if the user just types return. This is
7214 useful if the command is time-consuming to run, so that accidental
7215 extra keystrokes don't run the same command many times.
7217 * Send break instead of ^C
7219 The standard remote protocol now includes an option to send a break
7220 rather than a ^C to the target in order to interrupt it. By default,
7221 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7223 * Remote protocol timeout
7225 The standard remote protocol includes a new variable `remotetimeout'
7226 that allows you to set the number of seconds before GDB gives up trying
7227 to read from the target. The default value is 2.
7229 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7231 By default GDB will automatically keep track of objects as they are
7232 loaded and unloaded by the dynamic linker. By using the command `set
7233 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7234 when shared library events occur, thus allowing you to set breakpoints
7235 in shared libraries which are explicitly loaded by the inferior.
7237 Note this feature does not work on hpux8. On hpux9 you must link
7238 /usr/lib/end.o into your program. This feature should work
7239 automatically on hpux10.
7241 * Irix 5.x hardware watchpoint support
7243 Irix 5 configurations now support the use of hardware watchpoints.
7245 * Mips protocol "SYN garbage limit"
7247 When debugging a Mips target using the `target mips' protocol, you
7248 may set the number of characters that GDB will ignore by setting
7249 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7250 every character. The default value is 1050.
7252 * Recording and replaying remote debug sessions
7254 If you set `remotelogfile' to the name of a file, gdb will write to it
7255 a recording of a remote debug session. This recording may then be
7256 replayed back to gdb using "gdbreplay". See gdbserver/README for
7257 details. This is useful when you have a problem with GDB while doing
7258 remote debugging; you can make a recording of the session and send it
7259 to someone else, who can then recreate the problem.
7261 * Speedups for remote debugging
7263 GDB includes speedups for downloading and stepping MIPS systems using
7264 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7265 and more efficient S-record downloading.
7267 * Memory use reductions and statistics collection
7269 GDB now uses less memory and reports statistics about memory usage.
7270 Try the `maint print statistics' command, for example.
7272 *** Changes in GDB-4.15:
7274 * Psymtabs for XCOFF
7276 The symbol reader for AIX GDB now uses partial symbol tables. This
7277 can greatly improve startup time, especially for large executables.
7279 * Remote targets use caching
7281 Remote targets now use a data cache to speed up communication with the
7282 remote side. The data cache could lead to incorrect results because
7283 it doesn't know about volatile variables, thus making it impossible to
7284 debug targets which use memory mapped I/O devices. `set remotecache
7285 off' turns the data cache off.
7287 * Remote targets may have threads
7289 The standard remote protocol now includes support for multiple threads
7290 in the target system, using new protocol commands 'H' and 'T'. See
7291 gdb/remote.c for details.
7295 If GDB is configured with `--enable-netrom', then it will include
7296 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7297 acts as though it is a bank of ROM on the target board, but you can
7298 write into it over the network. GDB's support consists only of
7299 support for fast loading into the emulated ROM; to debug, you must use
7300 another protocol, such as standard remote protocol. The usual
7301 sequence is something like
7303 target nrom <netrom-hostname>
7305 target remote <netrom-hostname>:1235
7309 GDB now includes support for the Apple Macintosh, as a host only. It
7310 may be run as either an MPW tool or as a standalone application, and
7311 it can debug through the serial port. All the usual GDB commands are
7312 available, but to the target command, you must supply "serial" as the
7313 device type instead of "/dev/ttyXX". See mpw-README in the main
7314 directory for more information on how to build. The MPW configuration
7315 scripts */mpw-config.in support only a few targets, and only the
7316 mips-idt-ecoff target has been tested.
7320 GDB configuration now uses autoconf. This is not user-visible,
7321 but does simplify configuration and building.
7325 GDB now supports hpux10.
7327 *** Changes in GDB-4.14:
7329 * New native configurations
7331 x86 FreeBSD i[345]86-*-freebsd
7332 x86 NetBSD i[345]86-*-netbsd
7333 NS32k NetBSD ns32k-*-netbsd
7334 Sparc NetBSD sparc-*-netbsd
7338 A29K VxWorks a29k-*-vxworks
7339 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7340 CPU32 EST-300 emulator m68*-*-est*
7341 PowerPC ELF powerpc-*-elf
7344 * Alpha OSF/1 support for procfs
7346 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7347 possible to attach to running processes. As the mounting of the /proc
7348 filesystem is optional on the Alpha, GDB automatically determines
7349 the availability of /proc during startup. This can lead to problems
7350 if /proc is unmounted after GDB has been started.
7352 * Arguments to user-defined commands
7354 User commands may accept up to 10 arguments separated by whitespace.
7355 Arguments are accessed within the user command via $arg0..$arg9. A
7358 print $arg0 + $arg1 + $arg2
7360 To execute the command use:
7363 Defines the command "adder" which prints the sum of its three arguments.
7364 Note the arguments are text substitutions, so they may reference variables,
7365 use complex expressions, or even perform inferior function calls.
7367 * New `if' and `while' commands
7369 This makes it possible to write more sophisticated user-defined
7370 commands. Both commands take a single argument, which is the
7371 expression to evaluate, and must be followed by the commands to
7372 execute, one per line, if the expression is nonzero, the list being
7373 terminated by the word `end'. The `if' command list may include an
7374 `else' word, which causes the following commands to be executed only
7375 if the expression is zero.
7377 * Fortran source language mode
7379 GDB now includes partial support for Fortran 77. It will recognize
7380 Fortran programs and can evaluate a subset of Fortran expressions, but
7381 variables and functions may not be handled correctly. GDB will work
7382 with G77, but does not yet know much about symbols emitted by other
7385 * Better HPUX support
7387 Most debugging facilities now work on dynamic executables for HPPAs
7388 running hpux9 or later. You can attach to running dynamically linked
7389 processes, but by default the dynamic libraries will be read-only, so
7390 for instance you won't be able to put breakpoints in them. To change
7391 that behavior do the following before running the program:
7397 This will cause the libraries to be mapped private and read-write.
7398 To revert to the normal behavior, do this:
7404 You cannot set breakpoints or examine data in the library until after
7405 the library is loaded if the function/data symbols do not have
7408 GDB can now also read debug symbols produced by the HP C compiler on
7409 HPPAs (sorry, no C++, Fortran or 68k support).
7411 * Target byte order now dynamically selectable
7413 You can choose which byte order to use with a target system, via the
7414 commands "set endian big" and "set endian little", and you can see the
7415 current setting by using "show endian". You can also give the command
7416 "set endian auto", in which case GDB will use the byte order
7417 associated with the executable. Currently, only embedded MIPS
7418 configurations support dynamic selection of target byte order.
7420 * New DOS host serial code
7422 This version uses DPMI interrupts to handle buffered I/O, so you
7423 no longer need to run asynctsr when debugging boards connected to
7426 *** Changes in GDB-4.13:
7428 * New "complete" command
7430 This lists all the possible completions for the rest of the line, if it
7431 were to be given as a command itself. This is intended for use by emacs.
7433 * Trailing space optional in prompt
7435 "set prompt" no longer adds a space for you after the prompt you set. This
7436 allows you to set a prompt which ends in a space or one that does not.
7438 * Breakpoint hit counts
7440 "info break" now displays a count of the number of times the breakpoint
7441 has been hit. This is especially useful in conjunction with "ignore"; you
7442 can ignore a large number of breakpoint hits, look at the breakpoint info
7443 to see how many times the breakpoint was hit, then run again, ignoring one
7444 less than that number, and this will get you quickly to the last hit of
7447 * Ability to stop printing at NULL character
7449 "set print null-stop" will cause GDB to stop printing the characters of
7450 an array when the first NULL is encountered. This is useful when large
7451 arrays actually contain only short strings.
7453 * Shared library breakpoints
7455 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7456 breakpoints in shared libraries before the executable is run.
7458 * Hardware watchpoints
7460 There is a new hardware breakpoint for the watch command for sparclite
7461 targets. See gdb/sparclite/hw_breakpoint.note.
7463 Hardware watchpoints are also now supported under GNU/Linux.
7467 Annotations have been added. These are for use with graphical interfaces,
7468 and are still experimental. Currently only gdba.el uses these.
7470 * Improved Irix 5 support
7472 GDB now works properly with Irix 5.2.
7474 * Improved HPPA support
7476 GDB now works properly with the latest GCC and GAS.
7478 * New native configurations
7480 Sequent PTX4 i[34]86-sequent-ptx4
7481 HPPA running OSF/1 hppa*-*-osf*
7482 Atari TT running SVR4 m68*-*-sysv4*
7483 RS/6000 LynxOS rs6000-*-lynxos*
7487 OS/9000 i[34]86-*-os9k
7488 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7491 * Hitachi SH7000 and E7000-PC ICE support
7493 There is now support for communicating with the Hitachi E7000-PC ICE.
7494 This is available automatically when GDB is configured for the SH.
7498 As usual, a variety of small fixes and improvements, both generic
7499 and configuration-specific. See the ChangeLog for more detail.
7501 *** Changes in GDB-4.12:
7503 * Irix 5 is now supported
7507 GDB-4.12 on the HPPA has a number of changes which make it unable
7508 to debug the output from the currently released versions of GCC and
7509 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7510 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7511 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7514 *** Changes in GDB-4.11:
7516 * User visible changes:
7520 The "set remotedebug" option is now consistent between the mips remote
7521 target, remote targets using the gdb-specific protocol, UDI (AMD's
7522 debug protocol for the 29k) and the 88k bug monitor. It is now an
7523 integer specifying a debug level (normally 0 or 1, but 2 means more
7524 debugging info for the mips target).
7526 * DEC Alpha native support
7528 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7529 debug info, but GDB works fairly well with the DEC compiler and should
7530 work with a future GCC release. See the README file for a few
7531 Alpha-specific notes.
7533 * Preliminary thread implementation
7535 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7537 * LynxOS native and target support for 386
7539 This release has been hosted on LynxOS 2.2, and also can be configured
7540 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7543 * Improvements in C++ mangling/demangling.
7545 This release has much better g++ debugging, specifically in name
7546 mangling/demangling, virtual function calls, print virtual table,
7547 call methods, ...etc.
7549 *** Changes in GDB-4.10:
7551 * User visible changes:
7553 Remote debugging using the GDB-specific (`target remote') protocol now
7554 supports the `load' command. This is only useful if you have some
7555 other way of getting the stub to the target system, and you can put it
7556 somewhere in memory where it won't get clobbered by the download.
7558 Filename completion now works.
7560 When run under emacs mode, the "info line" command now causes the
7561 arrow to point to the line specified. Also, "info line" prints
7562 addresses in symbolic form (as well as hex).
7564 All vxworks based targets now support a user settable option, called
7565 vxworks-timeout. This option represents the number of seconds gdb
7566 should wait for responses to rpc's. You might want to use this if
7567 your vxworks target is, perhaps, a slow software simulator or happens
7568 to be on the far side of a thin network line.
7572 This release contains support for using a DEC alpha as a GDB host for
7573 cross debugging. Native alpha debugging is not supported yet.
7576 *** Changes in GDB-4.9:
7580 This is the first GDB release which is accompanied by a matching testsuite.
7581 The testsuite requires installation of dejagnu, which should be available
7582 via ftp from most sites that carry GNU software.
7586 'Cfront' style demangling has had its name changed to 'ARM' style, to
7587 emphasize that it was written from the specifications in the C++ Annotated
7588 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7589 disclaimers, it still generated too much confusion with users attempting to
7590 use gdb with AT&T cfront.
7594 GDB now uses a standard remote interface to a simulator library.
7595 So far, the library contains simulators for the Zilog Z8001/2, the
7596 Hitachi H8/300, H8/500 and Super-H.
7598 * New targets supported
7600 H8/300 simulator h8300-hitachi-hms or h8300hms
7601 H8/500 simulator h8500-hitachi-hms or h8500hms
7602 SH simulator sh-hitachi-hms or sh
7603 Z8000 simulator z8k-zilog-none or z8ksim
7604 IDT MIPS board over serial line mips-idt-ecoff
7606 Cross-debugging to GO32 targets is supported. It requires a custom
7607 version of the i386-stub.c module which is integrated with the
7608 GO32 memory extender.
7610 * New remote protocols
7612 MIPS remote debugging protocol.
7614 * New source languages supported
7616 This version includes preliminary support for Chill, a Pascal like language
7617 used by telecommunications companies. Chill support is also being integrated
7618 into the GNU compiler, but we don't know when it will be publically available.
7621 *** Changes in GDB-4.8:
7623 * HP Precision Architecture supported
7625 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7626 version of this support was available as a set of patches from the
7627 University of Utah. GDB does not support debugging of programs
7628 compiled with the HP compiler, because HP will not document their file
7629 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7630 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7632 Many problems in the preliminary version have been fixed.
7634 * Faster and better demangling
7636 We have improved template demangling and fixed numerous bugs in the GNU style
7637 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7638 character types (wchar_t) are now supported. Demangling of each symbol is now
7639 only done once, and is cached when the symbol table for a file is read in.
7640 This results in a small increase in memory usage for C programs, a moderate
7641 increase in memory usage for C++ programs, and a fantastic speedup in
7644 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7645 from the specifications in the Annotated Reference Manual, which AT&T's
7646 compiler does not actually implement.
7648 * G++ multiple inheritance compiler problem
7650 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7651 inheritance lattices was reworked to properly discover ambiguities. We
7652 recently found an example which causes this new algorithm to fail in a
7653 very subtle way, producing bad debug information for those classes.
7654 The file 'gcc.patch' (in this directory) can be applied to gcc to
7655 circumvent the problem. A future GCC release will contain a complete
7658 The previous G++ debug info problem (mentioned below for the gdb-4.7
7659 release) is fixed in gcc version 2.3.2.
7661 * Improved configure script
7663 The `configure' script will now attempt to guess your system type if
7664 you don't supply a host system type. The old scheme of supplying a
7665 host system triplet is preferable over using this. All the magic is
7666 done in the new `config.guess' script. Examine it for details.
7668 We have also brought our configure script much more in line with the FSF's
7669 version. It now supports the --with-xxx options. In particular,
7670 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7671 The resulting GDB will not be able to read arbitrary object file formats --
7672 only the format ``expected'' to be used on the configured target system.
7673 We hope to make this the default in a future release.
7675 * Documentation improvements
7677 There's new internal documentation on how to modify GDB, and how to
7678 produce clean changes to the code. We implore people to read it
7679 before submitting changes.
7681 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7682 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7683 `info' files are also provided. To build `info' files from scratch,
7684 you will need the latest `makeinfo' release, which will be available in
7685 a future texinfo-X.Y release.
7687 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7688 We're not sure exactly which versions have this problem, but it has
7689 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7690 or better. If that isn't possible, there is a patch in
7691 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7692 around this problem.
7696 GDB now supports array constants that can be used in expressions typed in by
7697 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7698 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7701 The new directory `gdb/sparclite' contains a program that demonstrates
7702 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7704 * New native hosts supported
7706 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7707 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7709 * New targets supported
7711 AMD 29k family via UDI a29k-amd-udi or udi29k
7713 * New file formats supported
7715 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7716 HPUX core files, and SCO 3.2v2 core files.
7720 Attaching to processes now works again; thanks for the many bug reports.
7722 We have also stomped on a bunch of core dumps caused by
7723 printf_filtered("%s") problems.
7725 We eliminated a copyright problem on the rpc and ptrace header files
7726 for VxWorks, which was discovered at the last minute during the 4.7
7727 release. You should now be able to build a VxWorks GDB.
7729 You can now interrupt gdb while an attached process is running. This
7730 will cause the attached process to stop, and give control back to GDB.
7732 We fixed problems caused by using too many file descriptors
7733 for reading symbols from object files and libraries. This was
7734 especially a problem for programs that used many (~100) shared
7737 The `step' command now only enters a subroutine if there is line number
7738 information for the subroutine. Otherwise it acts like the `next'
7739 command. Previously, `step' would enter subroutines if there was
7740 any debugging information about the routine. This avoids problems
7741 when using `cc -g1' on MIPS machines.
7743 * Internal improvements
7745 GDB's internal interfaces have been improved to make it easier to support
7746 debugging of multiple languages in the future.
7748 GDB now uses a common structure for symbol information internally.
7749 Minimal symbols (derived from linkage symbols in object files), partial
7750 symbols (from a quick scan of debug information), and full symbols
7751 contain a common subset of information, making it easier to write
7752 shared code that handles any of them.
7754 * New command line options
7756 We now accept --silent as an alias for --quiet.
7760 The memory-mapped-malloc library is now licensed under the GNU Library
7761 General Public License.
7763 *** Changes in GDB-4.7:
7765 * Host/native/target split
7767 GDB has had some major internal surgery to untangle the support for
7768 hosts and remote targets. Now, when you configure GDB for a remote
7769 target, it will no longer load in all of the support for debugging
7770 local programs on the host. When fully completed and tested, this will
7771 ensure that arbitrary host/target combinations are possible.
7773 The primary conceptual shift is to separate the non-portable code in
7774 GDB into three categories. Host specific code is required any time GDB
7775 is compiled on that host, regardless of the target. Target specific
7776 code relates to the peculiarities of the target, but can be compiled on
7777 any host. Native specific code is everything else: it can only be
7778 built when the host and target are the same system. Child process
7779 handling and core file support are two common `native' examples.
7781 GDB's use of /proc for controlling Unix child processes is now cleaner.
7782 It has been split out into a single module under the `target_ops' vector,
7783 plus two native-dependent functions for each system that uses /proc.
7785 * New hosts supported
7787 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7788 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7789 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7791 * New targets supported
7793 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7794 68030 and CPU32 m68030-*-*, m68332-*-*
7796 * New native hosts supported
7798 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7799 (386bsd is not well tested yet)
7800 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7802 * New file formats supported
7804 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7805 supports reading of `a.out.adobe' object files, which are an a.out
7806 format extended with minimal information about multiple sections.
7810 `show copying' is the same as the old `info copying'.
7811 `show warranty' is the same as `info warrantee'.
7812 These were renamed for consistency. The old commands continue to work.
7814 `info handle' is a new alias for `info signals'.
7816 You can now define pre-command hooks, which attach arbitrary command
7817 scripts to any command. The commands in the hook will be executed
7818 prior to the user's command. You can also create a hook which will be
7819 executed whenever the program stops. See gdb.texinfo.
7823 We now deal with Cfront style name mangling, and can even extract type
7824 info from mangled symbols. GDB can automatically figure out which
7825 symbol mangling style your C++ compiler uses.
7827 Calling of methods and virtual functions has been improved as well.
7831 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7832 fixed. This was due to mishandling of the extra N_SO stabs output
7835 We also finally got Ultrix 4.2 running in house, and fixed core file
7836 support, with help from a dozen people on the net.
7838 John M. Farrell discovered that the reason that single-stepping was so
7839 slow on all of the Mips based platforms (primarily SGI and DEC) was
7840 that we were trying to demangle and lookup a symbol used for internal
7841 purposes on every instruction that was being stepped through. Changing
7842 the name of that symbol so that it couldn't be mistaken for a C++
7843 mangled symbol sped things up a great deal.
7845 Rich Pixley sped up symbol lookups in general by getting much smarter
7846 about when C++ symbol mangling is necessary. This should make symbol
7847 completion (TAB on the command line) much faster. It's not as fast as
7848 we'd like, but it's significantly faster than gdb-4.6.
7852 A new user controllable variable 'call_scratch_address' can
7853 specify the location of a scratch area to be used when GDB
7854 calls a function in the target. This is necessary because the
7855 usual method of putting the scratch area on the stack does not work
7856 in systems that have separate instruction and data spaces.
7858 We integrated changes to support the 29k UDI (Universal Debugger
7859 Interface), but discovered at the last minute that we didn't have all
7860 of the appropriate copyright paperwork. We are working with AMD to
7861 resolve this, and hope to have it available soon.
7865 We have sped up the remote serial line protocol, especially for targets
7866 with lots of registers. It now supports a new `expedited status' ('T')
7867 message which can be used in place of the existing 'S' status message.
7868 This allows the remote stub to send only the registers that GDB
7869 needs to make a quick decision about single-stepping or conditional
7870 breakpoints, eliminating the need to fetch the entire register set for
7871 each instruction being stepped through.
7873 The GDB remote serial protocol now implements a write-through cache for
7874 registers, only re-reading the registers if the target has run.
7876 There is also a new remote serial stub for SPARC processors. You can
7877 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7878 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7879 processor with a serial port.
7883 Configure.in files have become much easier to read and modify. A new
7884 `table driven' format makes it more obvious what configurations are
7885 supported, and what files each one uses.
7889 There is a new opcodes library which will eventually contain all of the
7890 disassembly routines and opcode tables. At present, it only contains
7891 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7892 disassembler (binutils/objdump) to share these routines.
7894 The libiberty library is now copylefted under the GNU Library General
7895 Public License. This allows more liberal use, and was done so libg++
7896 can use it. This makes no difference to GDB, since the Library License
7897 grants all the rights from the General Public License.
7901 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7902 reference to the stabs symbol info used by the debugger. It is (as far
7903 as we know) the only published document on this fascinating topic. We
7904 encourage you to read it, compare it to the stabs information on your
7905 system, and send improvements on the document in general (to
7906 bug-gdb@prep.ai.mit.edu).
7908 And, of course, many bugs have been fixed.
7911 *** Changes in GDB-4.6:
7913 * Better support for C++ function names
7915 GDB now accepts as input the "demangled form" of C++ overloaded function
7916 names and member function names, and can do command completion on such names
7917 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7918 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7919 Make use of command completion, it is your friend.
7921 GDB also now accepts a variety of C++ mangled symbol formats. They are
7922 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7923 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7924 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7925 for the list of formats.
7927 * G++ symbol mangling problem
7929 Recent versions of gcc have a bug in how they emit debugging information for
7930 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7931 directory) can be applied to gcc to fix the problem. Alternatively, if you
7932 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7933 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7934 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7937 * New 'maintenance' command
7939 All of the commands related to hacking GDB internals have been moved out of
7940 the main command set, and now live behind the 'maintenance' command. This
7941 can also be abbreviated as 'mt'. The following changes were made:
7943 dump-me -> maintenance dump-me
7944 info all-breakpoints -> maintenance info breakpoints
7945 printmsyms -> maintenance print msyms
7946 printobjfiles -> maintenance print objfiles
7947 printpsyms -> maintenance print psymbols
7948 printsyms -> maintenance print symbols
7950 The following commands are new:
7952 maintenance demangle Call internal GDB demangler routine to
7953 demangle a C++ link name and prints the result.
7954 maintenance print type Print a type chain for a given symbol
7956 * Change to .gdbinit file processing
7958 We now read the $HOME/.gdbinit file before processing the argv arguments
7959 (e.g. reading symbol files or core files). This allows global parameters to
7960 be set, which will apply during the symbol reading. The ./.gdbinit is still
7961 read after argv processing.
7963 * New hosts supported
7965 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7967 GNU/Linux support i386-unknown-linux or linux
7969 We are also including code to support the HP/PA running BSD and HPUX. This
7970 is almost guaranteed not to work, as we didn't have time to test or build it
7971 for this release. We are including it so that the more adventurous (or
7972 masochistic) of you can play with it. We also had major problems with the
7973 fact that the compiler that we got from HP doesn't support the -g option.
7976 * New targets supported
7978 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7980 * More smarts about finding #include files
7982 GDB now remembers the compilation directory for all include files, and for
7983 all files from which C is generated (like yacc and lex sources). This
7984 greatly improves GDB's ability to find yacc/lex sources, and include files,
7985 especially if you are debugging your program from a directory different from
7986 the one that contains your sources.
7988 We also fixed a bug which caused difficulty with listing and setting
7989 breakpoints in include files which contain C code. (In the past, you had to
7990 try twice in order to list an include file that you hadn't looked at before.)
7992 * Interesting infernals change
7994 GDB now deals with arbitrary numbers of sections, where the symbols for each
7995 section must be relocated relative to that section's landing place in the
7996 target's address space. This work was needed to support ELF with embedded
7997 stabs used by Solaris-2.0.
7999 * Bug fixes (of course!)
8001 There have been loads of fixes for the following things:
8002 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8003 i960, stabs, DOS(GO32), procfs, etc...
8005 See the ChangeLog for details.
8007 *** Changes in GDB-4.5:
8009 * New machines supported (host and target)
8011 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8013 SGI Irix-4.x mips-sgi-irix4 or iris4
8015 * New malloc package
8017 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8018 Mmalloc is capable of handling multiple heaps of memory. It is also
8019 capable of saving a heap to a file, and then mapping it back in later.
8020 This can be used to greatly speedup the startup of GDB by using a
8021 pre-parsed symbol table which lives in a mmalloc managed heap. For
8022 more details, please read mmalloc/mmalloc.texi.
8026 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8027 'help info proc' for details.
8029 * MIPS ecoff symbol table format
8031 The code that reads MIPS symbol table format is now supported on all hosts.
8032 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8035 * File name changes for MS-DOS
8037 Many files in the config directories have been renamed to make it easier to
8038 support GDB on MS-DOSe systems (which have very restrictive file name
8039 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8040 environment) is close to working but has some remaining problems. Note
8041 that debugging of DOS programs is not supported, due to limitations
8042 in the ``operating system'', but it can be used to host cross-debugging.
8044 * Cross byte order fixes
8046 Many fixes have been made to support cross debugging of Sparc and MIPS
8047 targets from hosts whose byte order differs.
8049 * New -mapped and -readnow options
8051 If memory-mapped files are available on your system through the 'mmap'
8052 system call, you can use the -mapped option on the `file' or
8053 `symbol-file' commands to cause GDB to write the symbols from your
8054 program into a reusable file. If the program you are debugging is
8055 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8056 Future GDB debugging sessions will notice the presence of this file,
8057 and will quickly map in symbol information from it, rather than reading
8058 the symbol table from the executable program. Using the '-mapped'
8059 option in a GDB `file' or `symbol-file' command has the same effect as
8060 starting GDB with the '-mapped' command-line option.
8062 You can cause GDB to read the entire symbol table immediately by using
8063 the '-readnow' option with any of the commands that load symbol table
8064 information (or on the GDB command line). This makes the command
8065 slower, but makes future operations faster.
8067 The -mapped and -readnow options are typically combined in order to
8068 build a `fred.syms' file that contains complete symbol information.
8069 A simple GDB invocation to do nothing but build a `.syms' file for future
8072 gdb -batch -nx -mapped -readnow programname
8074 The `.syms' file is specific to the host machine on which GDB is run.
8075 It holds an exact image of GDB's internal symbol table. It cannot be
8076 shared across multiple host platforms.
8078 * longjmp() handling
8080 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8081 siglongjmp() without losing control. This feature has not yet been ported to
8082 all systems. It currently works on many 386 platforms, all MIPS-based
8083 platforms (SGI, DECstation, etc), and Sun3/4.
8087 Preliminary work has been put in to support the new Solaris OS from Sun. At
8088 this time, it can control and debug processes, but it is not capable of
8093 As always, many many bug fixes. The major areas were with g++, and mipsread.
8094 People using the MIPS-based platforms should experience fewer mysterious
8095 crashes and trashed symbol tables.
8097 *** Changes in GDB-4.4:
8099 * New machines supported (host and target)
8101 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8103 BSD Reno on Vax vax-dec-bsd
8104 Ultrix on Vax vax-dec-ultrix
8106 * New machines supported (target)
8108 AMD 29000 embedded, using EBMON a29k-none-none
8112 GDB continues to improve its handling of C++. `References' work better.
8113 The demangler has also been improved, and now deals with symbols mangled as
8114 per the Annotated C++ Reference Guide.
8116 GDB also now handles `stabs' symbol information embedded in MIPS
8117 `ecoff' symbol tables. Since the ecoff format was not easily
8118 extensible to handle new languages such as C++, this appeared to be a
8119 good way to put C++ debugging info into MIPS binaries. This option
8120 will be supported in the GNU C compiler, version 2, when it is
8123 * New features for SVR4
8125 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8126 shared libraries. Debugging dynamically linked programs should present
8127 only minor differences from debugging statically linked programs.
8129 The `info proc' command will print out information about any process
8130 on an SVR4 system (including the one you are debugging). At the moment,
8131 it prints the address mappings of the process.
8133 If you bring up GDB on another SVR4 system, please send mail to
8134 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8136 * Better dynamic linking support in SunOS
8138 Reading symbols from shared libraries which contain debugging symbols
8139 now works properly. However, there remain issues such as automatic
8140 skipping of `transfer vector' code during function calls, which
8141 make it harder to debug code in a shared library, than to debug the
8142 same code linked statically.
8146 GDB is now using the latest `getopt' routines from the FSF. This
8147 version accepts the -- prefix for options with long names. GDB will
8148 continue to accept the old forms (-option and +option) as well.
8149 Various single letter abbreviations for options have been explicity
8150 added to the option table so that they won't get overshadowed in the
8151 future by other options that begin with the same letter.
8155 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8156 Many assorted bugs have been handled. Many more remain to be handled.
8157 See the various ChangeLog files (primarily in gdb and bfd) for details.
8160 *** Changes in GDB-4.3:
8162 * New machines supported (host and target)
8164 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8165 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8166 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8168 * Almost SCO Unix support
8170 We had hoped to support:
8171 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8172 (except for core file support), but we discovered very late in the release
8173 that it has problems with process groups that render gdb unusable. Sorry
8174 about that. I encourage people to fix it and post the fixes.
8176 * Preliminary ELF and DWARF support
8178 GDB can read ELF object files on System V Release 4, and can handle
8179 debugging records for C, in DWARF format, in ELF files. This support
8180 is preliminary. If you bring up GDB on another SVR4 system, please
8181 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8186 GDB now uses the latest `readline' library. One user-visible change
8187 is that two tabs will list possible command completions, which previously
8188 required typing M-? (meta-question mark, or ESC ?).
8192 The `stepi' bug that many of you noticed has been squashed.
8193 Many bugs in C++ have been handled. Many more remain to be handled.
8194 See the various ChangeLog files (primarily in gdb and bfd) for details.
8196 * State of the MIPS world (in case you wondered):
8198 GDB can understand the symbol tables emitted by the compilers
8199 supplied by most vendors of MIPS-based machines, including DEC. These
8200 symbol tables are in a format that essentially nobody else uses.
8202 Some versions of gcc come with an assembler post-processor called
8203 mips-tfile. This program is required if you want to do source-level
8204 debugging of gcc-compiled programs. I believe FSF does not ship
8205 mips-tfile with gcc version 1, but it will eventually come with gcc
8208 Debugging of g++ output remains a problem. g++ version 1.xx does not
8209 really support it at all. (If you're lucky, you should be able to get
8210 line numbers and stack traces to work, but no parameters or local
8211 variables.) With some work it should be possible to improve the
8214 When gcc version 2 is released, you will have somewhat better luck.
8215 However, even then you will get confusing results for inheritance and
8218 We will eventually provide full debugging of g++ output on
8219 DECstations. This will probably involve some kind of stabs-in-ecoff
8220 encapulation, but the details have not been worked out yet.
8223 *** Changes in GDB-4.2:
8225 * Improved configuration
8227 Only one copy of `configure' exists now, and it is not self-modifying.
8228 Porting BFD is simpler.
8232 The `step' and `next' commands now only stop at the first instruction
8233 of a source line. This prevents the multiple stops that used to occur
8234 in switch statements, for-loops, etc. `Step' continues to stop if a
8235 function that has debugging information is called within the line.
8239 Lots of small bugs fixed. More remain.
8241 * New host supported (not target)
8243 Intel 386 PC clone running Mach i386-none-mach
8246 *** Changes in GDB-4.1:
8248 * Multiple source language support
8250 GDB now has internal scaffolding to handle several source languages.
8251 It determines the type of each source file from its filename extension,
8252 and will switch expression parsing and number formatting to match the
8253 language of the function in the currently selected stack frame.
8254 You can also specifically set the language to be used, with
8255 `set language c' or `set language modula-2'.
8259 GDB now has preliminary support for the GNU Modula-2 compiler,
8260 currently under development at the State University of New York at
8261 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8262 continue through the fall of 1991 and into 1992.
8264 Other Modula-2 compilers are currently not supported, and attempting to
8265 debug programs compiled with them will likely result in an error as the
8266 symbol table is read. Feel free to work on it, though!
8268 There are hooks in GDB for strict type checking and range checking,
8269 in the `Modula-2 philosophy', but they do not currently work.
8273 GDB can now write to executable and core files (e.g. patch
8274 a variable's value). You must turn this switch on, specify
8275 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8276 by assigning a new value to a variable. Modifications take
8279 * Automatic SunOS shared library reading
8281 When you run your program, GDB automatically determines where its
8282 shared libraries (if any) have been loaded, and reads their symbols.
8283 The `share' command is no longer needed. This also works when
8284 examining core files.
8288 You can specify the number of lines that the `list' command shows.
8291 * New machines supported (host and target)
8293 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8294 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8295 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8297 * New hosts supported (not targets)
8299 IBM RT/PC: romp-ibm-aix or rtpc
8301 * New targets supported (not hosts)
8303 AMD 29000 embedded with COFF a29k-none-coff
8304 AMD 29000 embedded with a.out a29k-none-aout
8305 Ultracomputer remote kernel debug a29k-nyu-kern
8307 * New remote interfaces
8313 *** Changes in GDB-4.0:
8317 Wide output is wrapped at good places to make the output more readable.
8319 Gdb now supports cross-debugging from a host machine of one type to a
8320 target machine of another type. Communication with the target system
8321 is over serial lines. The ``target'' command handles connecting to the
8322 remote system; the ``load'' command will download a program into the
8323 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8324 also supports debugging of realtime processes running under VxWorks,
8325 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8326 stub on the target system.
8328 New CPUs supported include the AMD 29000 and Intel 960.
8330 GDB now reads object files and symbol tables via a ``binary file''
8331 library, which allows a single copy of GDB to debug programs of multiple
8332 object file types such as a.out and coff.
8334 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8335 refcard.dvi and refcard.ps are available to format it).
8338 * Control-Variable user interface simplified
8340 All variables that control the operation of the debugger can be set
8341 by the ``set'' command, and displayed by the ``show'' command.
8343 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8344 ``Show prompt'' produces the response:
8345 Gdb's prompt is new-gdb=>.
8347 What follows are the NEW set commands. The command ``help set'' will
8348 print a complete list of old and new set commands. ``help set FOO''
8349 will give a longer description of the variable FOO. ``show'' will show
8350 all of the variable descriptions and their current settings.
8352 confirm on/off: Enables warning questions for operations that are
8353 hard to recover from, e.g. rerunning the program while
8354 it is already running. Default is ON.
8356 editing on/off: Enables EMACS style command line editing
8357 of input. Previous lines can be recalled with
8358 control-P, the current line can be edited with control-B,
8359 you can search for commands with control-R, etc.
8362 history filename NAME: NAME is where the gdb command history
8363 will be stored. The default is .gdb_history,
8364 or the value of the environment variable
8367 history size N: The size, in commands, of the command history. The
8368 default is 256, or the value of the environment variable
8371 history save on/off: If this value is set to ON, the history file will
8372 be saved after exiting gdb. If set to OFF, the
8373 file will not be saved. The default is OFF.
8375 history expansion on/off: If this value is set to ON, then csh-like
8376 history expansion will be performed on
8377 command line input. The default is OFF.
8379 radix N: Sets the default radix for input and output. It can be set
8380 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8381 in the current radix, so "set radix 10" is always a no-op.
8383 height N: This integer value is the number of lines on a page. Default
8384 is 24, the current `stty rows'' setting, or the ``li#''
8385 setting from the termcap entry matching the environment
8388 width N: This integer value is the number of characters on a line.
8389 Default is 80, the current `stty cols'' setting, or the ``co#''
8390 setting from the termcap entry matching the environment
8393 Note: ``set screensize'' is obsolete. Use ``set height'' and
8394 ``set width'' instead.
8396 print address on/off: Print memory addresses in various command displays,
8397 such as stack traces and structure values. Gdb looks
8398 more ``symbolic'' if you turn this off; it looks more
8399 ``machine level'' with it on. Default is ON.
8401 print array on/off: Prettyprint arrays. New convenient format! Default
8404 print demangle on/off: Print C++ symbols in "source" form if on,
8407 print asm-demangle on/off: Same, for assembler level printouts
8410 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8413 * Support for Epoch Environment.
8415 The epoch environment is a version of Emacs v18 with windowing. One
8416 new command, ``inspect'', is identical to ``print'', except that if you
8417 are running in the epoch environment, the value is printed in its own
8421 * Support for Shared Libraries
8423 GDB can now debug programs and core files that use SunOS shared libraries.
8424 Symbols from a shared library cannot be referenced
8425 before the shared library has been linked with the program (this
8426 happens after you type ``run'' and before the function main() is entered).
8427 At any time after this linking (including when examining core files
8428 from dynamically linked programs), gdb reads the symbols from each
8429 shared library when you type the ``sharedlibrary'' command.
8430 It can be abbreviated ``share''.
8432 sharedlibrary REGEXP: Load shared object library symbols for files
8433 matching a unix regular expression. No argument
8434 indicates to load symbols for all shared libraries.
8436 info sharedlibrary: Status of loaded shared libraries.
8441 A watchpoint stops execution of a program whenever the value of an
8442 expression changes. Checking for this slows down execution
8443 tremendously whenever you are in the scope of the expression, but is
8444 quite useful for catching tough ``bit-spreader'' or pointer misuse
8445 problems. Some machines such as the 386 have hardware for doing this
8446 more quickly, and future versions of gdb will use this hardware.
8448 watch EXP: Set a watchpoint (breakpoint) for an expression.
8450 info watchpoints: Information about your watchpoints.
8452 delete N: Deletes watchpoint number N (same as breakpoints).
8453 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8454 enable N: Re-enables watchpoint number N (same as breakpoints).
8457 * C++ multiple inheritance
8459 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8462 * C++ exception handling
8464 Gdb now supports limited C++ exception handling. Besides the existing
8465 ability to breakpoint on an exception handler, gdb can breakpoint on
8466 the raising of an exception (before the stack is peeled back to the
8469 catch FOO: If there is a FOO exception handler in the dynamic scope,
8470 set a breakpoint to catch exceptions which may be raised there.
8471 Multiple exceptions (``catch foo bar baz'') may be caught.
8473 info catch: Lists all exceptions which may be caught in the
8474 current stack frame.
8477 * Minor command changes
8479 The command ``call func (arg, arg, ...)'' now acts like the print
8480 command, except it does not print or save a value if the function's result
8481 is void. This is similar to dbx usage.
8483 The ``up'' and ``down'' commands now always print the frame they end up
8484 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8485 frames without printing.
8487 * New directory command
8489 'dir' now adds directories to the FRONT of the source search path.
8490 The path starts off empty. Source files that contain debug information
8491 about the directory in which they were compiled can be found even
8492 with an empty path; Sun CC and GCC include this information. If GDB can't
8493 find your source file in the current directory, type "dir .".
8495 * Configuring GDB for compilation
8497 For normal use, type ``./configure host''. See README or gdb.texinfo
8500 GDB now handles cross debugging. If you are remotely debugging between
8501 two different machines, type ``./configure host -target=targ''.
8502 Host is the machine where GDB will run; targ is the machine
8503 where the program that you are debugging will run.