1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 11
10 Enable or disable multithreaded symbol loading. This is enabled
11 by default, but passing --disable-threading or --enable-threading=no
12 to configure will disable it.
14 Disabling this can cause a performance penalty when there are a lot of
15 symbols to load, but is useful for debugging purposes.
19 maint set backtrace-on-fatal-signal on|off
20 maint show backtrace-on-fatal-signal
21 This setting is 'on' by default. When 'on' GDB will print a limited
22 backtrace to stderr in the situation where GDB terminates with a
23 fatal signal. This only supported on some platforms where the
24 backtrace and backtrace_symbols_fd functions are available.
26 set source open on|off
28 This setting, which is on by default, controls whether GDB will try
29 to open source code files. Switching this off will stop GDB trying
30 to open and read source code files, which can be useful if the files
31 are located over a slow network connection.
35 These are now deprecated aliases for "set max-value-size" and
36 "show max-value-size".
38 task apply [all | TASK-IDS...] [FLAG]... COMMAND
39 Like "thread apply", but applies COMMAND to Ada tasks.
42 Watchpoints can now be restricted to a specific Ada task.
44 maint set internal-error backtrace on|off
45 maint show internal-error backtrace
46 maint set internal-warning backtrace on|off
47 maint show internal-warning backtrace
48 GDB can now print a backtrace of itself when it encounters either an
49 internal-error, or an internal-warning. This is on by default for
50 internal-error and off by default for internal-warning.
53 Deprecated and replaced by "set logging enabled on|off".
55 set logging enabled on|off
57 These commands set or show whether logging is enabled or disabled.
60 You can now exit GDB by using the new command "exit", in addition to
61 the existing "quit" command.
63 set debug threads on|off
65 Print additional debug messages about thread creation and deletion.
67 set debug linux-nat on|off
69 These new commands replaced the old 'set debug lin-lwp' and 'show
70 debug lin-lwp' respectively. Turning this setting on prints debug
71 messages relating to GDB's handling of native Linux inferiors.
73 maint flush source-cache
74 Flush the contents of the source code cache.
76 maint set gnu-source-highlight enabled on|off
77 maint show gnu-source-highlight enabled
78 Whether GDB should use the GNU Source Highlight library for adding
79 styling to source code. When off, the library will not be used, even
80 when available. When GNU Source Highlight isn't used, or can't add
81 styling to a particular source file, then the Python Pygments
82 library will be used instead.
87 This command can now print a reply, if the reply includes
88 non-printable characters. Any non-printable characters are printed
89 as escaped hex, e.g. \x?? where '??' is replaces with the value of
90 the non-printable character.
93 The clone-inferior command now ensures that the TTY, CMD and ARGS
94 settings are copied from the original inferior to the new one.
95 All modifications to the environment variables done using the 'set
96 environment' or 'unset environment' commands are also copied to the new
99 set debug lin-lwp on|off
101 These commands have been removed from GDB. The new command 'set
102 debug linux-nat' and 'show debug linux-nat' should be used
107 ** New function gdb.add_history(), which takes a gdb.Value object
108 and adds the value it represents to GDB's history list. An
109 integer, the index of the new item in the history list, is
112 ** New function gdb.history_count(), which returns the number of
113 values in GDB's value history.
115 ** New gdb.events.gdb_exiting event. This event is called with a
116 gdb.GdbExitingEvent object which has the read-only attribute
117 'exit_code', which contains the value of the GDB exit code. This
118 event is triggered once GDB decides it is going to exit, but
119 before GDB starts to clean up its internal state.
121 ** New function gdb.architecture_names(), which returns a list
122 containing all of the possible Architecture.name() values. Each
125 ** New function gdb.Architecture.integer_type(), which returns an
126 integer type given a size and a signed-ness.
128 ** New gdb.TargetConnection object type that represents a connection
129 (as displayed by the 'info connections' command). A sub-class,
130 gdb.RemoteTargetConnection, is used to represent 'remote' and
131 'extended-remote' connections.
133 ** The gdb.Inferior type now has a 'connection' property which is an
134 instance of gdb.TargetConnection, the connection used by this
135 inferior. This can be None if the inferior has no connection.
137 ** New 'gdb.events.connection_removed' event registry, which emits a
138 'gdb.ConnectionEvent' when a connection is removed from GDB.
139 This event has a 'connection' property, a gdb.TargetConnection
140 object for the connection being removed.
142 ** New gdb.connections() function that returns a list of all
143 currently active connections.
145 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
146 is equivalent to the existing 'maint packet' CLI command; it
147 allows a user specified packet to be sent to the remote target.
149 ** New function gdb.host_charset(), returns a string, which is the
150 name of the current host charset.
152 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
155 ** New gdb.with_parameter(NAME, VALUE). This returns a context
156 manager that temporarily sets the gdb parameter NAME to VALUE,
157 then resets it when the context is exited.
159 * New features in the GDB remote stub, GDBserver
161 ** GDBserver is now supported on OpenRISC GNU/Linux.
163 * New native configurations
165 GNU/Linux/OpenRISC or1k*-*-linux*
167 *** Changes in GDB 11
169 * The 'set disassembler-options' command now supports specifying options
172 * GDB now supports general memory tagging functionality if the underlying
173 architecture supports the proper primitives and hooks. Currently this is
174 enabled only for AArch64 MTE.
178 - Additional information when the inferior crashes with a SIGSEGV caused by
179 a memory tag violation.
181 - A new modifier 'm' for the "x" command, which displays allocation tags for a
182 particular memory range.
184 - Display of memory tag mismatches by "print", for addresses and
185 pointers, if memory tagging is supported by the architecture.
187 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
192 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
194 The MI -break-insert and -dprintf-insert commands now support a
195 new "--qualified" option that makes GDB interpret a specified
196 function name as a complete fully-qualified name. This is the
197 equivalent of the CLI's "break -qualified" and "dprintf
200 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
202 The MI -break-insert and -dprintf-insert commands now support a
203 '--force-condition' flag to forcibly define a condition even when
204 the condition is invalid at all locations of the breakpoint. This
205 is equivalent to the '-force-condition' flag of the CLI's "break"
208 ** '-break-condition --force'
210 The MI -break-condition command now supports a '--force' flag to
211 forcibly define a condition even when the condition is invalid at
212 all locations of the selected breakpoint. This is equivalent to
213 the '-force' flag of the CLI's "cond" command.
215 ** '-file-list-exec-source-files [--group-by-objfile]
216 [--basename | --dirname]
219 The existing -file-list-exec-source-files command now takes an
220 optional REGEXP which is used to filter the source files that are
221 included in the results.
223 By default REGEXP is matched against the full filename of the
224 source file. When one of --basename or --dirname is given then
225 REGEXP is only matched against the specified part of the full
228 When the optional --group-by-objfile flag is used the output
229 format is changed, the results are now a list of object files
230 (executable and libraries) with the source files that are
231 associated with each object file.
233 The results from -file-list-exec-source-files now include a
234 'debug-fully-read' field which takes the value 'true' or 'false'.
235 A 'true' value indicates the source file is from a compilation
236 unit that has had its debug information fully read in by GDB, a
237 value of 'false' indicates GDB has only performed a partial scan
238 of the debug information so far.
240 * GDB now supports core file debugging for x86_64 Cygwin programs.
242 * GDB will now look for the .gdbinit file in a config directory before
243 looking for ~/.gdbinit. The file is searched for in the following
244 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
245 $HOME/.gdbinit. On Apple hosts the search order is instead:
246 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
248 * GDB now supports fixed point types which are described in DWARF
249 as base types with a fixed-point encoding. Additionally, support
250 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
253 For Ada, this allows support for fixed point types without requiring
254 the use of the GNAT encoding (based on information added to the type's
255 name following a GNAT-specific format).
257 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
258 or ~/.gdbearlyinit if these files are present. These files are
259 processed earlier than any of the other initialization files and
260 can affect parts of GDB's startup that previously had already been
261 completed before the initialization files were read, for example
262 styling of the initial GDB greeting.
264 * GDB now has two new options "--early-init-command" and
265 "--early-init-eval-command" with corresponding short options "-eix"
266 and "-eiex" that allow options (that would normally appear in a
267 gdbearlyinit file) to be passed on the command line.
269 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
270 now understood by GDB, and can be used to describe the vector
271 registers of a target. The precise requirements of this register
272 feature are documented in the GDB manual.
274 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
275 supported by GDB and describes a new VPR register from the ARM MVE
276 (Helium) extension. See the GDB manual for more information.
280 ** TUI windows now support mouse actions. The mouse wheel scrolls
281 the appropriate window.
283 ** Key combinations that do not have a specific action on the
284 focused window are passed to GDB. For example, you now can use
285 Ctrl-Left/Ctrl-Right to move between words in the command window
286 regardless of which window is in focus. Previously you would
287 need to focus on the command window for such key combinations to
293 show debug event-loop
294 Control the display of debug output about GDB's event loop.
296 set print memory-tag-violations
297 show print memory-tag-violations
298 Control whether to display additional information about memory tag violations
299 when printing pointers and addresses. Architecture support for memory
300 tagging is required for this option to have an effect.
302 maintenance flush symbol-cache
303 maintenance flush register-cache
304 These new commands are equivalent to the already existing commands
305 'maintenance flush-symbol-cache' and 'flushregs' respectively.
307 maintenance flush dcache
308 A new command to flush the dcache.
310 maintenance info target-sections
311 Print GDB's internal target sections table.
314 Print the JIT code objects in the inferior known to GDB.
316 memory-tag show-logical-tag POINTER
317 Print the logical tag for POINTER.
318 memory-tag with-logical-tag POINTER TAG
319 Print POINTER with logical tag TAG.
320 memory-tag show-allocation-tag ADDRESS
321 Print the allocation tag for ADDRESS.
322 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
323 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
324 memory-tag check POINTER
325 Validate that POINTER's logical tag matches the allocation tag.
327 set startup-quietly on|off
329 When 'on', this causes GDB to act as if "-silent" were passed on the
330 command line. This command needs to be added to an early
331 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
334 set print type hex on|off
336 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
337 and offsets of struct members. When 'off', decimal notation is used.
339 set python ignore-environment on|off
340 show python ignore-environment
341 When 'on', this causes GDB's builtin Python to ignore any
342 environment variables that would otherwise affect how Python
343 behaves. This command needs to be added to an early initialization
344 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
346 set python dont-write-bytecode auto|on|off
347 show python dont-write-bytecode
348 When 'on', this causes GDB's builtin Python to not write any
349 byte-code (.pyc files) to disk. This command needs to be added to
350 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
351 order to affect GDB. When 'off' byte-code will always be written.
352 When set to 'auto' (the default) Python will check the
353 PYTHONDONTWRITEBYTECODE environment variable.
357 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
358 [-force-condition] [if CONDITION]
359 This command would previously refuse setting a breakpoint if the
360 CONDITION expression is invalid at a location. It now accepts and
361 defines the breakpoint if there is at least one location at which
362 the CONDITION is valid. The locations for which the CONDITION is
363 invalid, are automatically disabled. If CONDITION is invalid at all
364 of the locations, setting the breakpoint is still rejected. However,
365 the '-force-condition' flag can be used in this case for forcing GDB to
366 define the breakpoint, making all the current locations automatically
367 disabled. This may be useful if the user knows the condition will
368 become meaningful at a future location, e.g. due to a shared library
371 condition [-force] N COND
372 The behavior of this command is changed the same way for the 'break'
373 command as explained above. The '-force' flag can be used to force
374 GDB into defining the condition even when COND is invalid for all the
375 current locations of breakpoint N.
378 maintenance flush-symbol-cache
379 These commands are deprecated in favor of the new commands
380 'maintenance flush register-cache' and 'maintenance flush
381 symbol-cache' respectively.
383 set style version foreground COLOR
384 set style version background COLOR
385 set style version intensity VALUE
386 Control the styling of GDB's version number text.
389 When the ID parameter is omitted, then this command prints information
390 about the current inferior. When the ID parameter is present, the
391 behavior of the command is unchanged and have the inferior ID become
392 the current inferior.
394 maintenance info sections
395 The ALLOBJ keyword has been replaced with an -all-objects command
396 line flag. It is now possible to filter which sections are printed
397 even when -all-objects is passed.
399 ptype[/FLAGS] TYPE | EXPRESSION
400 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
401 notation is used when printing sizes and offsets of struct members.
402 When '/d' is set, decimal notation is used when printing sizes and
403 offsets of struct members. Default behavior is given by 'show print
407 The info sources command output has been restructured. The results
408 are now based around a list of objfiles (executable and libraries),
409 and for each objfile the source files that are part of that objfile
412 * Removed targets and native configurations
414 ARM Symbian arm*-*-symbianelf*
419 Request the remote to send allocation tags for a particular memory range.
421 Request the remote to store the specified allocation tags to the requested
426 ** Improved support for rvalue reference values:
427 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
428 value-referenced-value procedure now handles rvalue reference
431 ** New procedures for obtaining value variants:
432 value-reference-value, value-rvalue-reference-value and
435 ** Temporary breakpoints can now be created with make-breakpoint and
436 tested for using breakpoint-temporary?.
440 ** Inferior objects now contain a read-only 'connection_num' attribute that
441 gives the connection number as seen in 'info connections' and
444 ** New method gdb.Frame.level() which returns the stack level of the
447 ** New method gdb.PendingFrame.level() which returns the stack level
450 ** When hitting a catchpoint, the Python API will now emit a
451 gdb.BreakpointEvent rather than a gdb.StopEvent. The
452 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
454 ** Python TUI windows can now receive mouse click events. If the
455 Window object implements the click method, it is called for each
456 mouse click event in this window.
458 *** Changes in GDB 10
460 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
461 and "org.gnu.gdb.arc.aux". The old names are still supported but
462 must be considered obsolete. They will be deprecated after some
465 * Help and apropos commands will now show the documentation of a
466 command only once, even if that command has one or more aliases.
467 These commands now show the command name, then all of its aliases,
468 and finally the description of the command.
470 * 'help aliases' now shows only the user defined aliases. GDB predefined
471 aliases are shown together with their aliased command.
473 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
474 debugging information as well as source code.
476 When built with debuginfod, GDB can automatically query debuginfod
477 servers for the separate debug files and source code of the executable
480 To build GDB with debuginfod, pass --with-debuginfod to configure (this
481 requires libdebuginfod, the debuginfod client library).
483 debuginfod is distributed with elfutils, starting with version 0.178.
485 You can get the latest version from https://sourceware.org/elfutils.
487 * Multi-target debugging support
489 GDB now supports debugging multiple target connections
490 simultaneously. For example, you can now have each inferior
491 connected to different remote servers running in different machines,
492 or have one inferior debugging a local native process, an inferior
493 debugging a core dump, etc.
495 This support is experimental and comes with some limitations -- you
496 can only resume multiple targets simultaneously if all targets
497 support non-stop mode, and all remote stubs or servers must support
498 the same set of remote protocol features exactly. See also "info
499 connections" and "add-inferior -no-connection" below, and "maint set
500 target-non-stop" in the user manual.
502 * New features in the GDB remote stub, GDBserver
504 ** GDBserver is now supported on ARC GNU/Linux.
506 ** GDBserver is now supported on RISC-V GNU/Linux.
508 ** GDBserver no longer supports these host triplets:
519 i[34567]86-*-mingw32ce*
521 * Debugging MS-Windows processes now sets $_exitsignal when the
522 inferior is terminated by a signal, instead of setting $_exitcode.
524 * Multithreaded symbol loading has now been enabled by default on systems
525 that support it (see entry for GDB 9, below), providing faster
526 performance for programs with many symbols.
528 * The $_siginfo convenience variable now also works on Windows targets,
529 and will display the EXCEPTION_RECORD of the last handled exception.
531 * TUI windows can now be arranged horizontally.
533 * The command history filename can now be set to the empty string
534 either using 'set history filename' or by setting 'GDBHISTFILE=' in
535 the environment. The effect of setting this filename to the empty
536 string is that GDB will not try to load any previous command
539 * On Windows targets, it is now possible to debug 32-bit programs with a
544 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
545 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
546 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
547 running process, this new option indicates whether to detect
548 a mismatch between the current executable file loaded by GDB and the
549 executable file used to start the process. If 'ask', the default,
550 display a warning and ask the user whether to load the process
551 executable file; if 'warn', just display a warning; if 'off', don't
552 attempt to detect a mismatch.
554 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
555 Define a new TUI layout, specifying its name and the windows that
558 maintenance print xml-tdesc [FILE]
559 Prints the current target description as an XML document. If the
560 optional FILE is provided (which is an XML target description) then
561 the target description is read from FILE into GDB, and then
564 maintenance print core-file-backed-mappings
565 Prints file-backed mappings loaded from a core file's note section.
566 Output is expected to be similar to that of "info proc mappings".
568 set debug fortran-array-slicing on|off
569 show debug fortran-array-slicing
570 Print debugging when taking slices of Fortran arrays.
572 set fortran repack-array-slices on|off
573 show fortran repack-array-slices
574 When taking slices from Fortran arrays and strings, if the slice is
575 non-contiguous within the original value then, when this option is
576 on, the new value will be repacked into a single contiguous value.
577 When this option is off, then the value returned will consist of a
578 descriptor that describes the slice within the memory of the
579 original parent value.
583 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
584 The alias command can now specify default args for an alias.
585 GDB automatically prepends the alias default args to the argument list
586 provided explicitly by the user.
587 For example, to have a backtrace with full details, you can define
589 'alias bt_ALL = backtrace -entry-values both -frame-arg all
590 -past-main -past-entry -full'.
591 Alias default arguments can also use a set of nested 'with' commands,
592 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
593 defines the alias pp10 that will pretty print a maximum of 10 elements
594 of the given expression (if the expression is an array).
598 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
604 ** gdb.register_window_type can be used to implement new TUI windows
607 ** Dynamic types can now be queried. gdb.Type has a new attribute,
608 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
609 field of a dynamic type may have None for its "bitpos" attribute
612 ** Commands written in Python can be in the "TUI" help class by
613 registering with the new constant gdb.COMMAND_TUI.
615 ** New method gdb.PendingFrame.architecture () to retrieve the
616 architecture of the pending frame.
618 ** New gdb.Architecture.registers method that returns a
619 gdb.RegisterDescriptorIterator object, an iterator that returns
620 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
621 way to query the registers available for an architecture.
623 ** New gdb.Architecture.register_groups method that returns a
624 gdb.RegisterGroupIterator object, an iterator that returns
625 gdb.RegisterGroup objects. The new RegisterGroup is a way to
626 discover the available register groups.
630 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
632 ** Procedures 'memory-port-read-buffer-size',
633 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
634 and 'set-memory-port-write-buffer-size!' are deprecated. When
635 using Guile 2.2 and later, users who need to control the size of
636 a memory port's internal buffer can use the 'setvbuf' procedure.
640 * 'thread-exited' event is now available in the annotations interface.
642 * New built-in convenience variables $_gdb_major and $_gdb_minor
643 provide the GDB version. They are handy for conditionally using
644 features available only in or since specific GDB versions, in
645 scripts that should work error-free with many different versions,
646 such as in system-wide init files.
648 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
649 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
650 of the GDB settings and the GDB maintenance settings. They are handy
651 for changing the logic of user defined commands depending on the
652 current GDB settings.
654 * GDB now supports Thread Local Storage (TLS) variables on several
655 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
656 architectures require kernel changes. TLS is not yet supported for
657 amd64 and i386 process core dumps.
659 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
660 addresses that required unmasking are shown in the backtrace with the
663 * Two new convenience functions $_cimag and $_creal that extract the
664 imaginary and real parts respectively from complex numbers.
666 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
667 provide the exitcode or exit status of the shell commands launched by
668 GDB commands such as "shell", "pipe" and "make".
670 * The command define-prefix can now define user defined prefix commands.
671 User defined commands can now be defined using these user defined prefix
674 * Command names can now use the . character.
676 * The RX port now supports XML target descriptions.
678 * GDB now shows the Ada task names at more places, e.g. in task switching
681 * GDB can now be compiled with Python 3 on Windows.
683 * New convenience variable $_ada_exception holds the address of the
684 Ada exception being thrown. This is set by Ada-related catchpoints.
686 * GDB can now place breakpoints on nested functions and subroutines in
687 Fortran code. The '::' operator can be used between parent and
688 child scopes when placing breakpoints, for example:
690 (gdb) break outer_function::inner_function
692 The 'outer_function::' prefix is only needed if 'inner_function' is
693 not visible in the current scope.
695 * In addition to the system-wide gdbinit file, if configured with
696 --with-system-gdbinit-dir, GDB will now also load files in that directory
697 as system gdbinit files, unless the -nx or -n flag is provided. Files
698 with extensions .gdb, .py and .scm are supported as long as GDB was
699 compiled with support for that language.
701 * GDB now supports multithreaded symbol loading for higher performance.
702 This feature is still in testing, so it is disabled by default. You
703 can turn it on using 'maint set worker-threads unlimited'.
707 ** The gdb.Value type has a new method 'format_string' which returns a
708 string representing the value. The formatting is controlled by the
709 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
710 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
711 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
713 ** gdb.Type has a new property 'objfile' which returns the objfile the
716 ** The frame information printed by the python frame filtering code
717 is now consistent with what the 'backtrace' command prints when
718 there are no filters, or when the 'backtrace' '-no-filters' option
721 ** The new function gdb.lookup_static_symbol can be used to look up
722 symbols with static linkage.
724 ** The new function gdb.lookup_static_symbols can be used to look up
725 all static symbols with static linkage.
727 ** gdb.Objfile has new methods 'lookup_global_symbol' and
728 'lookup_static_symbol' to lookup a symbol from this objfile only.
730 ** gdb.Block now supports the dictionary syntax for accessing symbols in
731 this block (e.g. block['local_variable']).
735 | [COMMAND] | SHELL_COMMAND
736 | -d DELIM COMMAND DELIM SHELL_COMMAND
737 pipe [COMMAND] | SHELL_COMMAND
738 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
739 Executes COMMAND and sends its output to SHELL_COMMAND.
740 With no COMMAND, repeat the last executed command
741 and send its output to SHELL_COMMAND.
743 define-prefix COMMAND
744 Define or mark a command as a user-defined prefix command.
746 with SETTING [VALUE] [-- COMMAND]
747 w SETTING [VALUE] [-- COMMAND]
748 Temporarily set SETTING, run COMMAND, and restore SETTING.
749 Usage: with SETTING -- COMMAND
750 With no COMMAND, repeats the last executed command.
751 SETTING is any GDB setting you can change with the "set"
752 subcommands. For example, 'with language c -- print someobj'
753 temporarily switches to the C language in order to print someobj.
754 Settings can be combined: 'w lang c -- w print elements unlimited --
755 usercmd' switches to the C language and runs usercmd with no limit
756 of array elements to print.
758 maint with SETTING [VALUE] [-- COMMAND]
759 Like "with", but works with "maintenance set" settings.
761 set may-call-functions [on|off]
762 show may-call-functions
763 This controls whether GDB will attempt to call functions in
764 the program, such as with expressions in the print command. It
765 defaults to on. Calling functions in the program being debugged
766 can have undesired side effects. It is now possible to forbid
767 such function calls. If function calls are forbidden, GDB will throw
768 an error when a command (such as print expression) calls a function
771 set print finish [on|off]
773 This controls whether the `finish' command will display the value
774 that is returned by the current function. When `off', the value is
775 still entered into the value history, but it is not printed. The
780 Allows deeply nested structures to be simplified when printing by
781 replacing deeply nested parts (beyond the max-depth) with ellipses.
782 The default max-depth is 20, but this can be set to unlimited to get
783 the old behavior back.
785 set print raw-values [on|off]
786 show print raw-values
787 By default, GDB applies the enabled pretty printers when printing a
788 value. This allows to ignore the enabled pretty printers for a series
789 of commands. The default is 'off'.
791 set logging debugredirect [on|off]
792 By default, GDB debug output will go to both the terminal and the logfile.
793 Set if you want debug output to go only to the log file.
795 set style title foreground COLOR
796 set style title background COLOR
797 set style title intensity VALUE
798 Control the styling of titles.
800 set style highlight foreground COLOR
801 set style highlight background COLOR
802 set style highlight intensity VALUE
803 Control the styling of highlightings.
805 maint set worker-threads
806 maint show worker-threads
807 Control the number of worker threads that can be used by GDB. The
808 default is 0. "unlimited" lets GDB choose a number that is
809 reasonable. Currently worker threads are only used when demangling
810 the names of linker symbols.
812 set style tui-border foreground COLOR
813 set style tui-border background COLOR
814 Control the styling of TUI borders.
816 set style tui-active-border foreground COLOR
817 set style tui-active-border background COLOR
818 Control the styling of the active TUI border.
820 maint set test-settings KIND
821 maint show test-settings KIND
822 A set of commands used by the testsuite for exercising the settings
825 maint set tui-resize-message [on|off]
826 maint show tui-resize-message
827 Control whether GDB prints a message each time the terminal is
828 resized when in TUI mode. This is primarily useful for testing the
831 set print frame-info [short-location|location|location-and-address
832 |source-and-location|source-line|auto]
833 show print frame-info
834 This controls what frame information is printed by the commands printing
835 a frame. This setting will e.g. influence the behaviour of 'backtrace',
836 'frame', 'stepi'. The python frame filtering also respect this setting.
837 The 'backtrace' '-frame-info' option can override this global setting.
839 set tui compact-source
840 show tui compact-source
842 Enable the "compact" display mode for the TUI source window. The
843 compact display uses only as much space as is needed for the line
844 numbers in the current file, and only a single space to separate the
845 line numbers from the source.
847 info modules [-q] [REGEXP]
848 Return a list of Fortran modules matching REGEXP, or all modules if
851 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
852 Return a list of functions within all modules, grouped by module.
853 The list of functions can be restricted with the optional regular
854 expressions. MODULE_REGEXP matches against the module name,
855 TYPE_REGEXP matches against the function type signature, and REGEXP
856 matches against the function name.
858 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
859 Return a list of variables within all modules, grouped by module.
860 The list of variables can be restricted with the optional regular
861 expressions. MODULE_REGEXP matches against the module name,
862 TYPE_REGEXP matches against the variable type, and REGEXP matches
863 against the variable name.
865 set debug remote-packet-max-chars
866 show debug remote-packet-max-chars
867 Controls the number of characters to output in a remote packet when using
869 The default is 512 bytes.
872 Lists the target connections currently in use.
877 The "help" command uses the title style to enhance the
878 readibility of its output by styling the classes and
882 Similarly to "help", the "apropos" command also uses the
883 title style for the command names. "apropos" accepts now
884 a flag "-v" (verbose) to show the full documentation
885 of matching commands and to use the highlight style to mark
886 the documentation parts matching REGEXP.
890 The GDB printf and eval commands can now print C-style and Ada-style
891 string convenience variables without calling functions in the program.
892 This allows to do formatted printing of strings without having
893 a running inferior, or when debugging a core dump.
895 info sources [-dirname | -basename] [--] [REGEXP]
896 This command has now optional arguments to only print the files
897 whose names match REGEXP. The arguments -dirname and -basename
898 allow to restrict matching respectively to the dirname and basename
902 The "show style" and its subcommands are now styling
903 a style name in their output using its own style, to help
904 the user visualize the different styles.
906 set print frame-arguments
907 The new value 'presence' indicates to only indicate the presence of
908 arguments using ..., instead of printing argument names and values.
910 set print raw-frame-arguments
911 show print raw-frame-arguments
913 These commands replace the similarly-named "set/show print raw
914 frame-arguments" commands (now with a dash instead of a space). The
915 old commands are now deprecated and may be removed in a future
918 add-inferior [-no-connection]
919 The add-inferior command now supports a "-no-connection" flag that
920 makes the new inferior start with no target connection associated.
921 By default, the new inferior inherits the target connection of the
922 current inferior. See also "info connections".
925 This command's output now includes a new "Connection" column
926 indicating which target connection an inferior is bound to. See
927 "info connections" above.
929 maint test-options require-delimiter
930 maint test-options unknown-is-error
931 maint test-options unknown-is-operand
932 maint show test-options-completion-result
933 Commands used by the testsuite to validate the command options
936 focus, winheight, +, -, >, <
937 These commands are now case-sensitive.
939 * New command options, command completion
941 GDB now has a standard infrastructure to support dash-style command
942 options ('-OPT'). One benefit is that commands that use it can
943 easily support completion of command line arguments. Try "CMD
944 -[TAB]" or "help CMD" to find options supported by a command. Over
945 time, we intend to migrate most commands to this infrastructure. A
946 number of commands got support for new command options in this
949 ** The "print" and "compile print" commands now support a number of
950 options that allow overriding relevant global print settings as
951 set by "set print" subcommands:
955 -array-indexes [on|off]
956 -elements NUMBER|unlimited
961 -repeats NUMBER|unlimited
962 -static-members [on|off]
967 Note that because the "print"/"compile print" commands accept
968 arbitrary expressions which may look like options (including
969 abbreviations), if you specify any command option, then you must
970 use a double dash ("--") to mark the end of argument processing.
972 ** The "backtrace" command now supports a number of options that
973 allow overriding relevant global print settings as set by "set
974 backtrace" and "set print" subcommands:
976 -entry-values no|only|preferred|if-needed|both|compact|default
977 -frame-arguments all|scalars|none
978 -raw-frame-arguments [on|off]
979 -frame-info auto|source-line|location|source-and-location
980 |location-and-address|short-location
984 In addition, the full/no-filters/hide qualifiers are now also
985 exposed as command options too:
991 ** The "frame apply", "tfaas" and "faas" commands similarly now
992 support the following options:
997 ** The new "info sources" options -dirname and -basename options
998 are using the standard '-OPT' infrastructure.
1000 All options above can also be abbreviated. The argument of boolean
1001 (on/off) options can be 0/1 too, and also the argument is assumed
1002 "on" if omitted. This allows writing compact command invocations,
1005 (gdb) p -ra -p -o 0 -- *myptr
1007 The above is equivalent to:
1009 (gdb) print -raw-values -pretty -object off -- *myptr
1011 ** The "info types" command now supports the '-q' flag to disable
1012 printing of some header information in a similar fashion to "info
1013 variables" and "info functions".
1015 ** The "info variables", "info functions", and "whereis" commands
1016 now take a '-n' flag that excludes non-debug symbols (symbols
1017 from the symbol table, not from the debug info such as DWARF)
1020 * Completion improvements
1022 ** GDB can now complete the options of the "thread apply all" and
1023 "taas" commands, and their "-ascending" option can now be
1026 ** GDB can now complete the options of the "info threads", "info
1027 functions", "info variables", "info locals", and "info args"
1030 ** GDB can now complete the options of the "compile file" and
1031 "compile code" commands. The "compile file" command now
1032 completes on filenames.
1034 ** GDB can now complete the backtrace command's
1035 "full/no-filters/hide" qualifiers.
1037 * In settings, you can now abbreviate "unlimited".
1039 E.g., "set print elements u" is now equivalent to "set print
1040 elements unlimited".
1045 This lists all the possible completions for the rest of the line, if it
1046 were to be given as a command itself. This is intended for use by MI
1047 frontends in cases when separate CLI and MI channels cannot be used.
1049 -catch-throw, -catch-rethrow, and -catch-catch
1050 These can be used to catch C++ exceptions in a similar fashion to
1051 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1053 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1054 These commands are the MI equivalent of the CLI commands 'info
1055 functions', 'info types', and 'info variables' respectively.
1057 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1060 -symbol-info-module-functions and -symbol-info-module-variables.
1061 These commands are the MI equivalent of the CLI commands 'info
1062 module functions' and 'info module variables'.
1066 ** The default version of the MI interpreter is now 3 (-i=mi3).
1068 ** The output of information about multi-location breakpoints (which is
1069 syntactically incorrect in MI 2) has changed in MI 3. This affects
1070 the following commands and events:
1074 - =breakpoint-created
1075 - =breakpoint-modified
1077 The -fix-multi-location-breakpoint-output command can be used to enable
1078 this behavior with previous MI versions.
1080 ** Backtraces and frames include a new optional field addr_flags which is
1081 given after the addr field. On AArch64 this contains PAC if the address
1082 has been masked in the frame. On all other targets the field is not
1087 The testsuite now creates the files gdb.cmd (containing the arguments
1088 used to launch GDB) and gdb.in (containing all the commands sent to
1089 GDB) in the output directory for each test script. Multiple invocations
1090 are appended with .1, .2, .3 etc.
1092 * Building GDB and GDBserver now requires GNU make >= 3.82.
1094 Using another implementation of the make program or an earlier version of
1095 GNU make to build GDB or GDBserver is not supported.
1097 * Building GDB now requires GNU readline >= 7.0.
1099 GDB now bundles GNU readline 8.0, but if you choose to use
1100 --with-system-readline, only readline >= 7.0 can be used.
1102 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1103 from .inputrc to bind keys in this keymap. This feature is only
1104 available when gdb is built against GNU readline 8.0 or later.
1106 * Removed targets and native configurations
1108 GDB no longer supports debugging the Cell Broadband Engine. This includes
1109 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1110 of Cell/B.E. applications that use both the PPU and SPU architectures.
1116 * Removed targets and native configurations
1118 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1119 sparc*-*-solaris2.10
1121 *** Changes in GDB 8.3
1123 * GDB and GDBserver now support access to additional registers on
1124 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1127 * GDB now has experimental support for the compilation and injection of
1128 C++ source code into the inferior. This beta release does not include
1129 support for several language features, such as templates, constructors,
1132 This feature requires GCC 7.1 or higher built with libcp1.so
1135 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1136 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1137 'ADDRESS:PORT' method.
1139 * DWARF index cache: GDB can now automatically save indices of DWARF
1140 symbols on disk to speed up further loading of the same binaries.
1142 * Ada task switching is now supported on aarch64-elf targets when
1143 debugging a program using the Ravenscar Profile. For more information,
1144 see the "Tasking Support when using the Ravenscar Profile" section
1145 in the GDB user manual.
1147 * GDB in batch mode now exits with status 1 if the last command to be
1150 * The RISC-V target now supports target descriptions.
1152 * System call catchpoints now support system call aliases on FreeBSD.
1153 When the ABI of a system call changes in FreeBSD, this is
1154 implemented by leaving a compatibility system call using the old ABI
1155 at the existing number and allocating a new system call number for
1156 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1157 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1158 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1159 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1160 so that a system call catchpoint for the 'kevent' system call will
1161 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1162 binaries. This ensures that 'kevent' system calls are caught for
1163 binaries using either the old or new ABIs.
1165 * Terminal styling is now available for the CLI and the TUI. GNU
1166 Source Highlight can additionally be used to provide styling of
1167 source code snippets. See the "set style" commands, below, for more
1170 * Removed support for old demangling styles arm, edg, gnu, hp and
1175 set debug compile-cplus-types
1176 show debug compile-cplus-types
1177 Control the display of debug output about type conversion in the
1178 C++ compile feature. Commands have no effect while compiling
1179 for other languages.
1183 Control whether debug output about files/functions skipping is
1186 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1187 Apply a command to some frames.
1188 FLAG arguments allow to control what output to produce and how to handle
1189 errors raised when applying COMMAND to a frame.
1192 Apply a command to all threads (ignoring errors and empty output).
1193 Shortcut for 'thread apply all -s COMMAND'.
1196 Apply a command to all frames (ignoring errors and empty output).
1197 Shortcut for 'frame apply all -s COMMAND'.
1200 Apply a command to all frames of all threads (ignoring errors and empty
1202 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1204 maint set dwarf unwinders (on|off)
1205 maint show dwarf unwinders
1206 Control whether DWARF unwinders can be used.
1209 Display a list of open files for a process.
1213 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1214 These commands all now take a frame specification which
1215 is either a frame level, or one of the keywords 'level', 'address',
1216 'function', or 'view' followed by a parameter. Selecting a frame by
1217 address, or viewing a frame outside the current backtrace now
1218 requires the use of a keyword. Selecting a frame by level is
1219 unchanged. The MI comment "-stack-select-frame" is unchanged.
1221 target remote FILENAME
1222 target extended-remote FILENAME
1223 If FILENAME is a Unix domain socket, GDB will attempt to connect
1224 to this socket instead of opening FILENAME as a character device.
1226 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1227 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1228 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1229 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1230 These commands can now print only the searched entities
1231 matching the provided regexp(s), giving a condition
1232 on the entity names or entity types. The flag -q disables
1233 printing headers or informations messages.
1239 These commands now determine the syntax for the shown entities
1240 according to the language chosen by `set language'. In particular,
1241 `set language auto' means to automatically choose the language of
1244 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1245 The 'thread apply' command accepts new FLAG arguments.
1246 FLAG arguments allow to control what output to produce and how to handle
1247 errors raised when applying COMMAND to a thread.
1249 set tui tab-width NCHARS
1250 show tui tab-width NCHARS
1251 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1253 set style enabled [on|off]
1255 Enable or disable terminal styling. Styling is enabled by default
1256 on most hosts, but disabled by default when in batch mode.
1258 set style sources [on|off]
1260 Enable or disable source code styling. Source code styling is
1261 enabled by default, but only takes effect if styling in general is
1262 enabled, and if GDB was linked with GNU Source Highlight.
1264 set style filename foreground COLOR
1265 set style filename background COLOR
1266 set style filename intensity VALUE
1267 Control the styling of file names.
1269 set style function foreground COLOR
1270 set style function background COLOR
1271 set style function intensity VALUE
1272 Control the styling of function names.
1274 set style variable foreground COLOR
1275 set style variable background COLOR
1276 set style variable intensity VALUE
1277 Control the styling of variable names.
1279 set style address foreground COLOR
1280 set style address background COLOR
1281 set style address intensity VALUE
1282 Control the styling of addresses.
1286 ** The '-data-disassemble' MI command now accepts an '-a' option to
1287 disassemble the whole function surrounding the given program
1288 counter value or function name. Support for this feature can be
1289 verified by using the "-list-features" command, which should
1290 contain "data-disassemble-a-option".
1292 ** Command responses and notifications that include a frame now include
1293 the frame's architecture in a new "arch" attribute.
1295 * New native configurations
1297 GNU/Linux/RISC-V riscv*-*-linux*
1298 FreeBSD/riscv riscv*-*-freebsd*
1302 GNU/Linux/RISC-V riscv*-*-linux*
1303 CSKY ELF csky*-*-elf
1304 CSKY GNU/LINUX csky*-*-linux
1305 FreeBSD/riscv riscv*-*-freebsd*
1307 GNU/Linux/OpenRISC or1k*-*-linux*
1311 GDB no longer supports native debugging on versions of MS-Windows
1316 ** GDB no longer supports Python versions less than 2.6.
1318 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1319 space associated to that inferior.
1321 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1322 of objfiles associated to that program space.
1324 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1325 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1328 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1329 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1330 correct and did not work properly.
1332 ** The gdb.Value type has a new constructor, which is used to construct a
1333 gdb.Value from a Python buffer object and a gdb.Type.
1339 Enable or disable the undefined behavior sanitizer. This is
1340 disabled by default, but passing --enable-ubsan=yes or
1341 --enable-ubsan=auto to configure will enable it. Enabling this can
1342 cause a performance penalty. The undefined behavior sanitizer was
1343 first introduced in GCC 4.9.
1345 *** Changes in GDB 8.2
1347 * The 'set disassembler-options' command now supports specifying options
1348 for the MIPS target.
1350 * The 'symbol-file' command now accepts an '-o' option to add a relative
1351 offset to all sections.
1353 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1354 a relative offset to all sections, but it allows to override the load
1355 address of individual sections using '-s'.
1357 * The 'add-symbol-file' command no longer requires the second argument
1358 (address of the text section).
1360 * The endianness used with the 'set endian auto' mode in the absence of
1361 an executable selected for debugging is now the last endianness chosen
1362 either by one of the 'set endian big' and 'set endian little' commands
1363 or by inferring from the last executable used, rather than the startup
1366 * The pager now allows a "c" response, meaning to disable the pager
1367 for the rest of the current command.
1369 * The commands 'info variables/functions/types' now show the source line
1370 numbers of symbol definitions when available.
1372 * 'info proc' now works on running processes on FreeBSD systems and core
1373 files created on FreeBSD systems.
1375 * C expressions can now use _Alignof, and C++ expressions can now use
1378 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1379 the vector length while the process is running.
1385 Control display of debugging info regarding the FreeBSD native target.
1387 set|show varsize-limit
1388 This new setting allows the user to control the maximum size of Ada
1389 objects being printed when those objects have a variable type,
1390 instead of that maximum size being hardcoded to 65536 bytes.
1392 set|show record btrace cpu
1393 Controls the processor to be used for enabling errata workarounds for
1394 branch trace decode.
1396 maint check libthread-db
1397 Run integrity checks on the current inferior's thread debugging
1400 maint set check-libthread-db (on|off)
1401 maint show check-libthread-db
1402 Control whether to run integrity checks on inferior specific thread
1403 debugging libraries as they are loaded. The default is not to
1404 perform such checks.
1408 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1410 ** The commands attached to a breakpoint can be set by assigning to
1411 the breakpoint's "commands" field.
1413 ** gdb.execute can now execute multi-line gdb commands.
1415 ** The new functions gdb.convenience_variable and
1416 gdb.set_convenience_variable can be used to get and set the value
1417 of convenience variables.
1419 ** A gdb.Parameter will no longer print the "set" help text on an
1420 ordinary "set"; instead by default a "set" will be silent unless
1421 the get_set_string method returns a non-empty string.
1425 RiscV ELF riscv*-*-elf
1427 * Removed targets and native configurations
1429 m88k running OpenBSD m88*-*-openbsd*
1430 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1431 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1432 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1434 * Aarch64/Linux hardware watchpoints improvements
1436 Hardware watchpoints on unaligned addresses are now properly
1437 supported when running Linux kernel 4.10 or higher: read and access
1438 watchpoints are no longer spuriously missed, and all watchpoints
1439 lengths between 1 and 8 bytes are supported. On older kernels,
1440 watchpoints set on unaligned addresses are no longer missed, with
1441 the tradeoff that there is a possibility of false hits being
1446 --enable-codesign=CERT
1447 This can be used to invoke "codesign -s CERT" after building gdb.
1448 This option is useful on macOS, where code signing is required for
1449 gdb to work properly.
1451 --disable-gdbcli has been removed
1452 This is now silently accepted, but does nothing.
1454 *** Changes in GDB 8.1
1456 * GDB now supports dynamically creating arbitrary register groups specified
1457 in XML target descriptions. This allows for finer grain grouping of
1458 registers on systems with a large amount of registers.
1460 * The 'ptype' command now accepts a '/o' flag, which prints the
1461 offsets and sizes of fields in a struct, like the pahole(1) tool.
1463 * New "--readnever" command line option instructs GDB to not read each
1464 symbol file's symbolic debug information. This makes startup faster
1465 but at the expense of not being able to perform symbolic debugging.
1466 This option is intended for use cases where symbolic debugging will
1467 not be used, e.g., when you only need to dump the debuggee's core.
1469 * GDB now uses the GNU MPFR library, if available, to emulate target
1470 floating-point arithmetic during expression evaluation when the target
1471 uses different floating-point formats than the host. At least version
1472 3.1 of GNU MPFR is required.
1474 * GDB now supports access to the guarded-storage-control registers and the
1475 software-based guarded-storage broadcast control registers on IBM z14.
1477 * On Unix systems, GDB now supports transmitting environment variables
1478 that are to be set or unset to GDBserver. These variables will
1479 affect the environment to be passed to the remote inferior.
1481 To inform GDB of environment variables that are to be transmitted to
1482 GDBserver, use the "set environment" command. Only user set
1483 environment variables are sent to GDBserver.
1485 To inform GDB of environment variables that are to be unset before
1486 the remote inferior is started by the GDBserver, use the "unset
1487 environment" command.
1489 * Completion improvements
1491 ** GDB can now complete function parameters in linespecs and
1492 explicit locations without quoting. When setting breakpoints,
1493 quoting around functions names to help with TAB-completion is
1494 generally no longer necessary. For example, this now completes
1497 (gdb) b function(in[TAB]
1498 (gdb) b function(int)
1500 Related, GDB is no longer confused with completing functions in
1501 C++ anonymous namespaces:
1504 (gdb) b (anonymous namespace)::[TAB][TAB]
1505 (anonymous namespace)::a_function()
1506 (anonymous namespace)::b_function()
1508 ** GDB now has much improved linespec and explicit locations TAB
1509 completion support, that better understands what you're
1510 completing and offers better suggestions. For example, GDB no
1511 longer offers data symbols as possible completions when you're
1512 setting a breakpoint.
1514 ** GDB now TAB-completes label symbol names.
1516 ** The "complete" command now mimics TAB completion accurately.
1518 * New command line options (gcore)
1521 Dump all memory mappings.
1523 * Breakpoints on C++ functions are now set on all scopes by default
1525 By default, breakpoints on functions/methods are now interpreted as
1526 specifying all functions with the given name ignoring missing
1527 leading scopes (namespaces and classes).
1529 For example, assuming a C++ program with symbols named:
1534 both commands "break func()" and "break B::func()" set a breakpoint
1537 You can use the new flag "-qualified" to override this. This makes
1538 GDB interpret the specified function name as a complete
1539 fully-qualified name instead. For example, using the same C++
1540 program, the "break -q B::func" command sets a breakpoint on
1541 "B::func", only. A parameter has been added to the Python
1542 gdb.Breakpoint constructor to achieve the same result when creating
1543 a breakpoint from Python.
1545 * Breakpoints on functions marked with C++ ABI tags
1547 GDB can now set breakpoints on functions marked with C++ ABI tags
1548 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1549 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1551 Functions with a C++11 abi tag are demangled/displayed like this:
1553 function[abi:cxx11](int)
1556 You can now set a breakpoint on such functions simply as if they had
1559 (gdb) b function(int)
1561 Or if you need to disambiguate between tags, like:
1563 (gdb) b function[abi:other_tag](int)
1565 Tab completion was adjusted accordingly as well.
1569 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1570 gdb.new_thread are emitted. See the manual for further
1571 description of these.
1573 ** A new function, "gdb.rbreak" has been added to the Python API.
1574 This function allows the setting of a large number of breakpoints
1575 via a regex pattern in Python. See the manual for further details.
1577 ** Python breakpoints can now accept explicit locations. See the
1578 manual for a further description of this feature.
1581 * New features in the GDB remote stub, GDBserver
1583 ** GDBserver is now able to start inferior processes with a
1584 specified initial working directory.
1586 The user can set the desired working directory to be used from
1587 GDB using the new "set cwd" command.
1589 ** New "--selftest" command line option runs some GDBserver self
1590 tests. These self tests are disabled in releases.
1592 ** On Unix systems, GDBserver now does globbing expansion and variable
1593 substitution in inferior command line arguments.
1595 This is done by starting inferiors using a shell, like GDB does.
1596 See "set startup-with-shell" in the user manual for how to disable
1597 this from GDB when using "target extended-remote". When using
1598 "target remote", you can disable the startup with shell by using the
1599 new "--no-startup-with-shell" GDBserver command line option.
1601 ** On Unix systems, GDBserver now supports receiving environment
1602 variables that are to be set or unset from GDB. These variables
1603 will affect the environment to be passed to the inferior.
1605 * When catching an Ada exception raised with a message, GDB now prints
1606 the message in the catchpoint hit notification. In GDB/MI mode, that
1607 information is provided as an extra field named "exception-message"
1608 in the *stopped notification.
1610 * Trait objects can now be inspected When debugging Rust code. This
1611 requires compiler support which will appear in Rust 1.24.
1613 * New remote packets
1615 QEnvironmentHexEncoded
1616 Inform GDBserver of an environment variable that is to be passed to
1617 the inferior when starting it.
1620 Inform GDBserver of an environment variable that is to be unset
1621 before starting the remote inferior.
1624 Inform GDBserver that the environment should be reset (i.e.,
1625 user-set environment variables should be unset).
1628 Indicates whether the inferior must be started with a shell or not.
1631 Tell GDBserver that the inferior to be started should use a specific
1634 * The "maintenance print c-tdesc" command now takes an optional
1635 argument which is the file name of XML target description.
1637 * The "maintenance selftest" command now takes an optional argument to
1638 filter the tests to be run.
1640 * The "enable", and "disable" commands now accept a range of
1641 breakpoint locations, e.g. "enable 1.3-5".
1646 Set and show the current working directory for the inferior.
1648 set|show compile-gcc
1649 Set and show compilation command used for compiling and injecting code
1650 with the 'compile' commands.
1652 set debug separate-debug-file
1653 show debug separate-debug-file
1654 Control the display of debug output about separate debug file search.
1656 set dump-excluded-mappings
1657 show dump-excluded-mappings
1658 Control whether mappings marked with the VM_DONTDUMP flag should be
1659 dumped when generating a core file.
1661 maint info selftests
1662 List the registered selftests.
1665 Start the debugged program stopping at the first instruction.
1668 Control display of debugging messages related to OpenRISC targets.
1670 set|show print type nested-type-limit
1671 Set and show the limit of nesting level for nested types that the
1672 type printer will show.
1674 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1677 * Safer/improved support for debugging with no debug info
1679 GDB no longer assumes functions with no debug information return
1682 This means that GDB now refuses to call such functions unless you
1683 tell it the function's type, by either casting the call to the
1684 declared return type, or by casting the function to a function
1685 pointer of the right type, and calling that:
1687 (gdb) p getenv ("PATH")
1688 'getenv' has unknown return type; cast the call to its declared return type
1689 (gdb) p (char *) getenv ("PATH")
1690 $1 = 0x7fffffffe "/usr/local/bin:/"...
1691 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1692 $2 = 0x7fffffffe "/usr/local/bin:/"...
1694 Similarly, GDB no longer assumes that global variables with no debug
1695 info have type 'int', and refuses to print the variable's value
1696 unless you tell it the variable's type:
1699 'var' has unknown type; cast it to its declared type
1703 * New native configurations
1705 FreeBSD/aarch64 aarch64*-*-freebsd*
1706 FreeBSD/arm arm*-*-freebsd*
1710 FreeBSD/aarch64 aarch64*-*-freebsd*
1711 FreeBSD/arm arm*-*-freebsd*
1712 OpenRISC ELF or1k*-*-elf
1714 * Removed targets and native configurations
1716 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1718 *** Changes in GDB 8.0
1720 * GDB now supports access to the PKU register on GNU/Linux. The register is
1721 added by the Memory Protection Keys for Userspace feature which will be
1722 available in future Intel CPUs.
1724 * GDB now supports C++11 rvalue references.
1728 ** New functions to start, stop and access a running btrace recording.
1729 ** Rvalue references are now supported in gdb.Type.
1731 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1734 * Building GDB and GDBserver now requires a C++11 compiler.
1736 For example, GCC 4.8 or later.
1738 It is no longer possible to build GDB or GDBserver with a C
1739 compiler. The --disable-build-with-cxx configure option has been
1742 * Building GDB and GDBserver now requires GNU make >= 3.81.
1744 It is no longer supported to build GDB or GDBserver with another
1745 implementation of the make program or an earlier version of GNU make.
1747 * Native debugging on MS-Windows supports command-line redirection
1749 Command-line arguments used for starting programs on MS-Windows can
1750 now include redirection symbols supported by native Windows shells,
1751 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1752 as "run", "start", and "set args", as well as the corresponding MI
1755 * Support for thread names on MS-Windows.
1757 GDB now catches and handles the special exception that programs
1758 running on MS-Windows use to assign names to threads in the
1761 * Support for Java programs compiled with gcj has been removed.
1763 * User commands now accept an unlimited number of arguments.
1764 Previously, only up to 10 was accepted.
1766 * The "eval" command now expands user-defined command arguments.
1768 This makes it easier to process a variable number of arguments:
1773 eval "print $arg%d", $i
1778 * Target descriptions can now describe registers for sparc32 and sparc64.
1780 * GDB now supports DWARF version 5 (debug information format).
1781 Its .debug_names index is not yet supported.
1783 * New native configurations
1785 FreeBSD/mips mips*-*-freebsd
1789 Synopsys ARC arc*-*-elf32
1790 FreeBSD/mips mips*-*-freebsd
1792 * Removed targets and native configurations
1794 Alpha running FreeBSD alpha*-*-freebsd*
1795 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1800 Erases all the flash memory regions reported by the target.
1802 maint print arc arc-instruction address
1803 Print internal disassembler information about instruction at a given address.
1807 set disassembler-options
1808 show disassembler-options
1809 Controls the passing of target specific information to the disassembler.
1810 If it is necessary to specify more than one disassembler option then
1811 multiple options can be placed together into a comma separated list.
1812 The default value is the empty string. Currently, the only supported
1813 targets are ARM, PowerPC and S/390.
1818 Erases all the flash memory regions reported by the target. This is
1819 equivalent to the CLI command flash-erase.
1821 -file-list-shared-libraries
1822 List the shared libraries in the program. This is
1823 equivalent to the CLI command "info shared".
1826 Catchpoints stopping the program when Ada exceptions are
1827 handled. This is equivalent to the CLI command "catch handlers".
1829 *** Changes in GDB 7.12
1831 * GDB and GDBserver now build with a C++ compiler by default.
1833 The --enable-build-with-cxx configure option is now enabled by
1834 default. One must now explicitly configure with
1835 --disable-build-with-cxx in order to build with a C compiler. This
1836 option will be removed in a future release.
1838 * GDBserver now supports recording btrace without maintaining an active
1841 * GDB now supports a negative repeat count in the 'x' command to examine
1842 memory backward from the given address. For example:
1845 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1846 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1847 (gdb) x/-5i 0x0000000000400580
1848 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1849 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1850 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1851 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1852 0x40057b <main(int, char**)+25>:
1853 callq 0x400536 <Func1(int, char const*)>
1855 * Fortran: Support structures with fields of dynamic types and
1856 arrays of dynamic types.
1858 * The symbol dumping maintenance commands have new syntax.
1859 maint print symbols [-pc address] [--] [filename]
1860 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1861 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1862 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1863 maint print msymbols [-objfile objfile] [--] [filename]
1865 * GDB now supports multibit bitfields and enums in target register
1868 * New Python-based convenience function $_as_string(val), which returns
1869 the textual representation of a value. This function is especially
1870 useful to obtain the text label of an enum value.
1872 * Intel MPX bound violation handling.
1874 Segmentation faults caused by a Intel MPX boundary violation
1875 now display the kind of violation (upper or lower), the memory
1876 address accessed and the memory bounds, along with the usual
1877 signal received and code location.
1881 Program received signal SIGSEGV, Segmentation fault
1882 Upper bound violation while accessing address 0x7fffffffc3b3
1883 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1884 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1886 * Rust language support.
1887 GDB now supports debugging programs written in the Rust programming
1888 language. See https://www.rust-lang.org/ for more information about
1891 * Support for running interpreters on specified input/output devices
1893 GDB now supports a new mechanism that allows frontends to provide
1894 fully featured GDB console views, as a better alternative to
1895 building such views on top of the "-interpreter-exec console"
1896 command. See the new "new-ui" command below. With that command,
1897 frontends can now start GDB in the traditional command-line mode
1898 running in an embedded terminal emulator widget, and create a
1899 separate MI interpreter running on a specified i/o device. In this
1900 way, GDB handles line editing, history, tab completion, etc. in the
1901 console all by itself, and the GUI uses the separate MI interpreter
1902 for its own control and synchronization, invisible to the command
1905 * The "catch syscall" command catches groups of related syscalls.
1907 The "catch syscall" command now supports catching a group of related
1908 syscalls using the 'group:' or 'g:' prefix.
1913 skip -gfile file-glob-pattern
1914 skip -function function
1915 skip -rfunction regular-expression
1916 A generalized form of the skip command, with new support for
1917 glob-style file names and regular expressions for function names.
1918 Additionally, a file spec and a function spec may now be combined.
1920 maint info line-table REGEXP
1921 Display the contents of GDB's internal line table data structure.
1924 Run any GDB unit tests that were compiled in.
1927 Start a new user interface instance running INTERP as interpreter,
1928 using the TTY file for input/output.
1932 ** gdb.Breakpoint objects have a new attribute "pending", which
1933 indicates whether the breakpoint is pending.
1934 ** Three new breakpoint-related events have been added:
1935 gdb.breakpoint_created, gdb.breakpoint_modified, and
1936 gdb.breakpoint_deleted.
1938 signal-event EVENTID
1939 Signal ("set") the given MS-Windows event object. This is used in
1940 conjunction with the Windows JIT debugging (AeDebug) support, where
1941 the OS suspends a crashing process until a debugger can attach to
1942 it. Resuming the crashing process, in order to debug it, is done by
1943 signalling an event.
1945 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1946 was added in GDBserver, including JIT compiling fast tracepoint's
1947 conditional expression bytecode into native code.
1949 * Support for various remote target protocols and ROM monitors has
1952 target m32rsdi Remote M32R debugging over SDI
1953 target mips MIPS remote debugging protocol
1954 target pmon PMON ROM monitor
1955 target ddb NEC's DDB variant of PMON for Vr4300
1956 target rockhopper NEC RockHopper variant of PMON
1957 target lsi LSI variant of PMO
1959 * Support for tracepoints and fast tracepoints on powerpc-linux,
1960 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1961 including JIT compiling fast tracepoint's conditional expression
1962 bytecode into native code.
1964 * MI async record =record-started now includes the method and format used for
1965 recording. For example:
1967 =record-started,thread-group="i1",method="btrace",format="bts"
1969 * MI async record =thread-selected now includes the frame field. For example:
1971 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1975 Andes NDS32 nds32*-*-elf
1977 *** Changes in GDB 7.11
1979 * GDB now supports debugging kernel-based threads on FreeBSD.
1981 * Per-inferior thread numbers
1983 Thread numbers are now per inferior instead of global. If you're
1984 debugging multiple inferiors, GDB displays thread IDs using a
1985 qualified INF_NUM.THR_NUM form. For example:
1989 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1990 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1991 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1992 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1994 As consequence, thread numbers as visible in the $_thread
1995 convenience variable and in Python's InferiorThread.num attribute
1996 are no longer unique between inferiors.
1998 GDB now maintains a second thread ID per thread, referred to as the
1999 global thread ID, which is the new equivalent of thread numbers in
2000 previous releases. See also $_gthread below.
2002 For backwards compatibility, MI's thread IDs always refer to global
2005 * Commands that accept thread IDs now accept the qualified
2006 INF_NUM.THR_NUM form as well. For example:
2009 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2012 * In commands that accept a list of thread IDs, you can now refer to
2013 all threads of an inferior using a star wildcard. GDB accepts
2014 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2015 refer to all threads of the current inferior. For example, "info
2018 * You can use "info threads -gid" to display the global thread ID of
2021 * The new convenience variable $_gthread holds the global number of
2024 * The new convenience variable $_inferior holds the number of the
2027 * GDB now displays the ID and name of the thread that hit a breakpoint
2028 or received a signal, if your program is multi-threaded. For
2031 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2032 Thread 1 "main" received signal SIGINT, Interrupt.
2034 * Record btrace now supports non-stop mode.
2036 * Support for tracepoints on aarch64-linux was added in GDBserver.
2038 * The 'record instruction-history' command now indicates speculative execution
2039 when using the Intel Processor Trace recording format.
2041 * GDB now allows users to specify explicit locations, bypassing
2042 the linespec parser. This feature is also available to GDB/MI
2045 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2046 GDB now is able to debug both AArch64 applications and ARM applications
2049 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2050 including JIT compiling fast tracepoint's conditional expression bytecode
2053 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2055 * "info threads", "info inferiors", "info display", "info checkpoints"
2056 and "maint info program-spaces" now list the corresponding items in
2057 ascending ID order, for consistency with all other "info" commands.
2059 * In Ada, the overloads selection menu has been enhanced to display the
2060 parameter types and the return types for the matching overloaded subprograms.
2064 maint set target-non-stop (on|off|auto)
2065 maint show target-non-stop
2066 Control whether GDB targets always operate in non-stop mode even if
2067 "set non-stop" is "off". The default is "auto", meaning non-stop
2068 mode is enabled if supported by the target.
2070 maint set bfd-sharing
2071 maint show bfd-sharing
2072 Control the reuse of bfd objects.
2075 show debug bfd-cache
2076 Control display of debugging info regarding bfd caching.
2080 Control display of debugging info regarding FreeBSD threads.
2082 set remote multiprocess-extensions-packet
2083 show remote multiprocess-extensions-packet
2084 Set/show the use of the remote protocol multiprocess extensions.
2086 set remote thread-events
2087 show remote thread-events
2088 Set/show the use of thread create/exit events.
2090 set ada print-signatures on|off
2091 show ada print-signatures"
2092 Control whether parameter types and return types are displayed in overloads
2093 selection menus. It is activated (@code{on}) by default.
2097 Controls the maximum size of memory, in bytes, that GDB will
2098 allocate for value contents. Prevents incorrect programs from
2099 causing GDB to allocate overly large buffers. Default is 64k.
2101 * The "disassemble" command accepts a new modifier: /s.
2102 It prints mixed source+disassembly like /m with two differences:
2103 - disassembled instructions are now printed in program order, and
2104 - and source for all relevant files is now printed.
2105 The "/m" option is now considered deprecated: its "source-centric"
2106 output hasn't proved useful in practice.
2108 * The "record instruction-history" command accepts a new modifier: /s.
2109 It behaves exactly like /m and prints mixed source+disassembly.
2111 * The "set scheduler-locking" command supports a new mode "replay".
2112 It behaves like "off" in record mode and like "on" in replay mode.
2114 * Support for various ROM monitors has been removed:
2116 target dbug dBUG ROM monitor for Motorola ColdFire
2117 target picobug Motorola picobug monitor
2118 target dink32 DINK32 ROM monitor for PowerPC
2119 target m32r Renesas M32R/D ROM monitor
2120 target mon2000 mon2000 ROM monitor
2121 target ppcbug PPCBUG ROM monitor for PowerPC
2123 * Support for reading/writing memory and extracting values on architectures
2124 whose memory is addressable in units of any integral multiple of 8 bits.
2127 Allows to break when an Ada exception is handled.
2129 * New remote packets
2132 Indicates that an exec system call was executed.
2134 exec-events feature in qSupported
2135 The qSupported packet allows GDB to request support for exec
2136 events using the new 'gdbfeature' exec-event, and the qSupported
2137 response can contain the corresponding 'stubfeature'. Set and
2138 show commands can be used to display whether these features are enabled.
2141 Equivalent to interrupting with the ^C character, but works in
2144 thread created stop reason (T05 create:...)
2145 Indicates that the thread was just created and is stopped at entry.
2147 thread exit stop reply (w exitcode;tid)
2148 Indicates that the thread has terminated.
2151 Enables/disables thread create and exit event reporting. For
2152 example, this is used in non-stop mode when GDB stops a set of
2153 threads and synchronously waits for the their corresponding stop
2154 replies. Without exit events, if one of the threads exits, GDB
2155 would hang forever not knowing that it should no longer expect a
2156 stop for that same thread.
2159 Indicates that there are no resumed threads left in the target (all
2160 threads are stopped). The remote stub reports support for this stop
2161 reply to GDB's qSupported query.
2164 Enables/disables catching syscalls from the inferior process.
2165 The remote stub reports support for this packet to GDB's qSupported query.
2167 syscall_entry stop reason
2168 Indicates that a syscall was just called.
2170 syscall_return stop reason
2171 Indicates that a syscall just returned.
2173 * Extended-remote exec events
2175 ** GDB now has support for exec events on extended-remote Linux targets.
2176 For such targets with Linux kernels 2.5.46 and later, this enables
2177 follow-exec-mode and exec catchpoints.
2179 set remote exec-event-feature-packet
2180 show remote exec-event-feature-packet
2181 Set/show the use of the remote exec event feature.
2183 * Thread names in remote protocol
2185 The reply to qXfer:threads:read may now include a name attribute for each
2188 * Target remote mode fork and exec events
2190 ** GDB now has support for fork and exec events on target remote mode
2191 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2192 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2193 fork and exec catchpoints.
2195 * Remote syscall events
2197 ** GDB now has support for catch syscall on remote Linux targets,
2198 currently enabled on x86/x86_64 architectures.
2200 set remote catch-syscall-packet
2201 show remote catch-syscall-packet
2202 Set/show the use of the remote catch syscall feature.
2206 ** The -var-set-format command now accepts the zero-hexadecimal
2207 format. It outputs data in hexadecimal format with zero-padding on the
2212 ** gdb.InferiorThread objects have a new attribute "global_num",
2213 which refers to the thread's global thread ID. The existing
2214 "num" attribute now refers to the thread's per-inferior number.
2215 See "Per-inferior thread numbers" above.
2216 ** gdb.InferiorThread objects have a new attribute "inferior", which
2217 is the Inferior object the thread belongs to.
2219 *** Changes in GDB 7.10
2221 * Support for process record-replay and reverse debugging on aarch64*-linux*
2222 targets has been added. GDB now supports recording of A64 instruction set
2223 including advance SIMD instructions.
2225 * Support for Sun's version of the "stabs" debug file format has been removed.
2227 * GDB now honors the content of the file /proc/PID/coredump_filter
2228 (PID is the process ID) on GNU/Linux systems. This file can be used
2229 to specify the types of memory mappings that will be included in a
2230 corefile. For more information, please refer to the manual page of
2231 "core(5)". GDB also has a new command: "set use-coredump-filter
2232 on|off". It allows to set whether GDB will read the content of the
2233 /proc/PID/coredump_filter file when generating a corefile.
2235 * The "info os" command on GNU/Linux can now display information on
2237 "info os cpus" Listing of all cpus/cores on the system
2239 * GDB has two new commands: "set serial parity odd|even|none" and
2240 "show serial parity". These allows to set or show parity for the
2243 * The "info source" command now displays the producer string if it was
2244 present in the debug info. This typically includes the compiler version
2245 and may include things like its command line arguments.
2247 * The "info dll", an alias of the "info sharedlibrary" command,
2248 is now available on all platforms.
2250 * Directory names supplied to the "set sysroot" commands may be
2251 prefixed with "target:" to tell GDB to access shared libraries from
2252 the target system, be it local or remote. This replaces the prefix
2253 "remote:". The default sysroot has been changed from "" to
2254 "target:". "remote:" is automatically converted to "target:" for
2255 backward compatibility.
2257 * The system root specified by "set sysroot" will be prepended to the
2258 filename of the main executable (if reported to GDB as absolute by
2259 the operating system) when starting processes remotely, and when
2260 attaching to already-running local or remote processes.
2262 * GDB now supports automatic location and retrieval of executable
2263 files from remote targets. Remote debugging can now be initiated
2264 using only a "target remote" or "target extended-remote" command
2265 (no "set sysroot" or "file" commands are required). See "New remote
2268 * The "dump" command now supports verilog hex format.
2270 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2272 * On GNU/Linux, GDB and gdbserver are now able to access executable
2273 and shared library files without a "set sysroot" command when
2274 attaching to processes running in different mount namespaces from
2275 the debugger. This makes it possible to attach to processes in
2276 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2277 See "New remote packets" below.
2279 * The "tui reg" command now provides completion for all of the
2280 available register groups, including target specific groups.
2282 * The HISTSIZE environment variable is no longer read when determining
2283 the size of GDB's command history. GDB now instead reads the dedicated
2284 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2285 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2290 ** Memory ports can now be unbuffered.
2294 ** gdb.Objfile objects have a new attribute "username",
2295 which is the name of the objfile as specified by the user,
2296 without, for example, resolving symlinks.
2297 ** You can now write frame unwinders in Python.
2298 ** gdb.Type objects have a new method "optimized_out",
2299 returning optimized out gdb.Value instance of this type.
2300 ** gdb.Value objects have new methods "reference_value" and
2301 "const_value" which return a reference to the value and a
2302 "const" version of the value respectively.
2306 maint print symbol-cache
2307 Print the contents of the symbol cache.
2309 maint print symbol-cache-statistics
2310 Print statistics of symbol cache usage.
2312 maint flush-symbol-cache
2313 Flush the contents of the symbol cache.
2317 Start branch trace recording using Branch Trace Store (BTS) format.
2320 Evaluate expression by using the compiler and print result.
2324 Explicit commands for enabling and disabling tui mode.
2327 set mpx bound on i386 and amd64
2328 Support for bound table investigation on Intel MPX enabled applications.
2332 Start branch trace recording using Intel Processor Trace format.
2335 Print information about branch tracing internals.
2337 maint btrace packet-history
2338 Print the raw branch tracing data.
2340 maint btrace clear-packet-history
2341 Discard the stored raw branch tracing data.
2344 Discard all branch tracing data. It will be fetched and processed
2345 anew by the next "record" command.
2350 Renamed from "set debug dwarf2-die".
2351 show debug dwarf-die
2352 Renamed from "show debug dwarf2-die".
2354 set debug dwarf-read
2355 Renamed from "set debug dwarf2-read".
2356 show debug dwarf-read
2357 Renamed from "show debug dwarf2-read".
2359 maint set dwarf always-disassemble
2360 Renamed from "maint set dwarf2 always-disassemble".
2361 maint show dwarf always-disassemble
2362 Renamed from "maint show dwarf2 always-disassemble".
2364 maint set dwarf max-cache-age
2365 Renamed from "maint set dwarf2 max-cache-age".
2366 maint show dwarf max-cache-age
2367 Renamed from "maint show dwarf2 max-cache-age".
2369 set debug dwarf-line
2370 show debug dwarf-line
2371 Control display of debugging info regarding DWARF line processing.
2374 show max-completions
2375 Set the maximum number of candidates to be considered during
2376 completion. The default value is 200. This limit allows GDB
2377 to avoid generating large completion lists, the computation of
2378 which can cause the debugger to become temporarily unresponsive.
2380 set history remove-duplicates
2381 show history remove-duplicates
2382 Control the removal of duplicate history entries.
2384 maint set symbol-cache-size
2385 maint show symbol-cache-size
2386 Control the size of the symbol cache.
2388 set|show record btrace bts buffer-size
2389 Set and show the size of the ring buffer used for branch tracing in
2391 The obtained size may differ from the requested size. Use "info
2392 record" to see the obtained buffer size.
2394 set debug linux-namespaces
2395 show debug linux-namespaces
2396 Control display of debugging info regarding Linux namespaces.
2398 set|show record btrace pt buffer-size
2399 Set and show the size of the ring buffer used for branch tracing in
2400 Intel Processor Trace format.
2401 The obtained size may differ from the requested size. Use "info
2402 record" to see the obtained buffer size.
2404 maint set|show btrace pt skip-pad
2405 Set and show whether PAD packets are skipped when computing the
2408 * The command 'thread apply all' can now support new option '-ascending'
2409 to call its specified command for all threads in ascending order.
2411 * Python/Guile scripting
2413 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2414 special section named `.debug_gdb_scripts'.
2416 * New remote packets
2418 qXfer:btrace-conf:read
2419 Return the branch trace configuration for the current thread.
2421 Qbtrace-conf:bts:size
2422 Set the requested ring buffer size for branch tracing in BTS format.
2425 Enable Intel Processor Trace-based branch tracing for the current
2426 process. The remote stub reports support for this packet to GDB's
2429 Qbtrace-conf:pt:size
2430 Set the requested ring buffer size for branch tracing in Intel Processor
2434 Indicates a memory breakpoint instruction was executed, irrespective
2435 of whether it was GDB that planted the breakpoint or the breakpoint
2436 is hardcoded in the program. This is required for correct non-stop
2440 Indicates the target stopped for a hardware breakpoint. This is
2441 required for correct non-stop mode operation.
2444 Return information about files on the remote system.
2446 qXfer:exec-file:read
2447 Return the full absolute name of the file that was executed to
2448 create a process running on the remote system.
2451 Select the filesystem on which vFile: operations with filename
2452 arguments will operate. This is required for GDB to be able to
2453 access files on remote targets where the remote stub does not
2454 share a common filesystem with the inferior(s).
2457 Indicates that a fork system call was executed.
2460 Indicates that a vfork system call was executed.
2462 vforkdone stop reason
2463 Indicates that a vfork child of the specified process has executed
2464 an exec or exit, allowing the vfork parent to resume execution.
2466 fork-events and vfork-events features in qSupported
2467 The qSupported packet allows GDB to request support for fork and
2468 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2469 and the qSupported response can contain the corresponding
2470 'stubfeatures'. Set and show commands can be used to display
2471 whether these features are enabled.
2473 * Extended-remote fork events
2475 ** GDB now has support for fork events on extended-remote Linux
2476 targets. For targets with Linux kernels 2.5.60 and later, this
2477 enables follow-fork-mode and detach-on-fork for both fork and
2478 vfork, as well as fork and vfork catchpoints.
2480 * The info record command now shows the recording format and the
2481 branch tracing configuration for the current thread when using
2482 the btrace record target.
2483 For the BTS format, it shows the ring buffer size.
2485 * GDB now has support for DTrace USDT (Userland Static Defined
2486 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2488 * GDB now supports access to vector registers on S/390 GNU/Linux
2491 * Removed command line options
2493 -xdb HP-UX XDB compatibility mode.
2495 * Removed targets and native configurations
2497 HP/PA running HP-UX hppa*-*-hpux*
2498 Itanium running HP-UX ia64-*-hpux*
2500 * New configure options
2503 This configure option allows the user to build GDB with support for
2504 Intel Processor Trace (default: auto). This requires libipt.
2506 --with-libipt-prefix=PATH
2507 Specify the path to the version of libipt that GDB should use.
2508 $PATH/include should contain the intel-pt.h header and
2509 $PATH/lib should contain the libipt.so library.
2511 *** Changes in GDB 7.9.1
2515 ** Xmethods can now specify a result type.
2517 *** Changes in GDB 7.9
2519 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2523 ** You can now access frame registers from Python scripts.
2524 ** New attribute 'producer' for gdb.Symtab objects.
2525 ** gdb.Objfile objects have a new attribute "progspace",
2526 which is the gdb.Progspace object of the containing program space.
2527 ** gdb.Objfile objects have a new attribute "owner".
2528 ** gdb.Objfile objects have a new attribute "build_id",
2529 which is the build ID generated when the file was built.
2530 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2531 ** A new event "gdb.clear_objfiles" has been added, triggered when
2532 selecting a new file to debug.
2533 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2534 ** New function gdb.lookup_objfile.
2536 New events which are triggered when GDB modifies the state of the
2539 ** gdb.events.inferior_call_pre: Function call is about to be made.
2540 ** gdb.events.inferior_call_post: Function call has just been made.
2541 ** gdb.events.memory_changed: A memory location has been altered.
2542 ** gdb.events.register_changed: A register has been altered.
2544 * New Python-based convenience functions:
2546 ** $_caller_is(name [, number_of_frames])
2547 ** $_caller_matches(regexp [, number_of_frames])
2548 ** $_any_caller_is(name [, number_of_frames])
2549 ** $_any_caller_matches(regexp [, number_of_frames])
2551 * GDB now supports the compilation and injection of source code into
2552 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2553 to compile the source code to object code, and if successful, inject
2554 and execute that code within the current context of the inferior.
2555 Currently the C language is supported. The commands used to
2556 interface with this new feature are:
2558 compile code [-raw|-r] [--] [source code]
2559 compile file [-raw|-r] filename
2563 demangle [-l language] [--] name
2564 Demangle "name" in the specified language, or the current language
2565 if elided. This command is renamed from the "maint demangle" command.
2566 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2567 as "maint demangler-warning".
2569 queue-signal signal-name-or-number
2570 Queue a signal to be delivered to the thread when it is resumed.
2572 add-auto-load-scripts-directory directory
2573 Add entries to the list of directories from which to load auto-loaded
2576 maint print user-registers
2577 List all currently available "user" registers.
2579 compile code [-r|-raw] [--] [source code]
2580 Compile, inject, and execute in the inferior the executable object
2581 code produced by compiling the provided source code.
2583 compile file [-r|-raw] filename
2584 Compile and inject into the inferior the executable object code
2585 produced by compiling the source code stored in the filename
2588 * On resume, GDB now always passes the signal the program had stopped
2589 for to the thread the signal was sent to, even if the user changed
2590 threads before resuming. Previously GDB would often (but not
2591 always) deliver the signal to the thread that happens to be current
2594 * Conversely, the "signal" command now consistently delivers the
2595 requested signal to the current thread. GDB now asks for
2596 confirmation if the program had stopped for a signal and the user
2597 switched threads meanwhile.
2599 * "breakpoint always-inserted" modes "off" and "auto" merged.
2601 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2602 won't remove breakpoints from the target until all threads stop,
2603 even in non-stop mode. The "auto" mode has been removed, and "off"
2604 is now the default mode.
2608 set debug symbol-lookup
2609 show debug symbol-lookup
2610 Control display of debugging info regarding symbol lookup.
2614 ** The -list-thread-groups command outputs an exit-code field for
2615 inferiors that have exited.
2619 MIPS SDE mips*-sde*-elf*
2623 Support for these obsolete configurations has been removed.
2625 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2626 SGI Irix-5.x mips-*-irix5*
2627 SGI Irix-6.x mips-*-irix6*
2628 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2629 VAX running Ultrix vax-*-ultrix*
2631 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2632 and "assf"), have been removed. Use the "sharedlibrary" command, or
2633 its alias "share", instead.
2635 *** Changes in GDB 7.8
2637 * New command line options
2640 This is an alias for the --data-directory option.
2642 * GDB supports printing and modifying of variable length automatic arrays
2643 as specified in ISO C99.
2645 * The ARM simulator now supports instruction level tracing
2646 with or without disassembly.
2650 GDB now has support for scripting using Guile. Whether this is
2651 available is determined at configure time.
2652 Guile version 2.0 or greater is required.
2653 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2655 * New commands (for set/show, see "New options" below)
2659 Invoke CODE by passing it to the Guile interpreter.
2663 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2665 info auto-load guile-scripts [regexp]
2666 Print the list of automatically loaded Guile scripts.
2668 * The source command is now capable of sourcing Guile scripts.
2669 This feature is dependent on the debugger being built with Guile support.
2673 set print symbol-loading (off|brief|full)
2674 show print symbol-loading
2675 Control whether to print informational messages when loading symbol
2676 information for a file. The default is "full", but when debugging
2677 programs with large numbers of shared libraries the amount of output
2678 becomes less useful.
2680 set guile print-stack (none|message|full)
2681 show guile print-stack
2682 Show a stack trace when an error is encountered in a Guile script.
2684 set auto-load guile-scripts (on|off)
2685 show auto-load guile-scripts
2686 Control auto-loading of Guile script files.
2688 maint ada set ignore-descriptive-types (on|off)
2689 maint ada show ignore-descriptive-types
2690 Control whether the debugger should ignore descriptive types in Ada
2691 programs. The default is not to ignore the descriptive types. See
2692 the user manual for more details on descriptive types and the intended
2693 usage of this option.
2695 set auto-connect-native-target
2697 Control whether GDB is allowed to automatically connect to the
2698 native target for the run, attach, etc. commands when not connected
2699 to any target yet. See also "target native" below.
2701 set record btrace replay-memory-access (read-only|read-write)
2702 show record btrace replay-memory-access
2703 Control what memory accesses are allowed during replay.
2705 maint set target-async (on|off)
2706 maint show target-async
2707 This controls whether GDB targets operate in synchronous or
2708 asynchronous mode. Normally the default is asynchronous, if it is
2709 available; but this can be changed to more easily debug problems
2710 occurring only in synchronous mode.
2712 set mi-async (on|off)
2714 Control whether MI asynchronous mode is preferred. This supersedes
2715 "set target-async" of previous GDB versions.
2717 * "set target-async" is deprecated as a CLI option and is now an alias
2718 for "set mi-async" (only puts MI into async mode).
2720 * Background execution commands (e.g., "c&", "s&", etc.) are now
2721 possible ``out of the box'' if the target supports them. Previously
2722 the user would need to explicitly enable the possibility with the
2723 "set target-async on" command.
2725 * New features in the GDB remote stub, GDBserver
2727 ** New option --debug-format=option1[,option2,...] allows one to add
2728 additional text to each output. At present only timestamps
2729 are supported: --debug-format=timestamps.
2730 Timestamps can also be turned on with the
2731 "monitor set debug-format timestamps" command from GDB.
2733 * The 'record instruction-history' command now starts counting instructions
2734 at one. This also affects the instruction ranges reported by the
2735 'record function-call-history' command when given the /i modifier.
2737 * The command 'record function-call-history' supports a new modifier '/c' to
2738 indent the function names based on their call stack depth.
2739 The fields for the '/i' and '/l' modifier have been reordered.
2740 The source line range is now prefixed with 'at'.
2741 The instruction range is now prefixed with 'inst'.
2742 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2743 "record instruction-history" and "list" commands.
2745 * The ranges given as arguments to the 'record function-call-history' and
2746 'record instruction-history' commands are now inclusive.
2748 * The btrace record target now supports the 'record goto' command.
2749 For locations inside the execution trace, the back trace is computed
2750 based on the information stored in the execution trace.
2752 * The btrace record target supports limited reverse execution and replay.
2753 The target does not record data and therefore does not allow reading
2754 memory or registers.
2756 * The "catch syscall" command now works on s390*-linux* targets.
2758 * The "compare-sections" command is no longer specific to target
2759 remote. It now works with all targets.
2761 * All native targets are now consistently called "native".
2762 Consequently, the "target child", "target GNU", "target djgpp",
2763 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2764 commands have been replaced with "target native". The QNX/NTO port
2765 leaves the "procfs" target in place and adds a "native" target for
2766 consistency with other ports. The impact on users should be minimal
2767 as these commands previously either throwed an error, or were
2768 no-ops. The target's name is visible in the output of the following
2769 commands: "help target", "info target", "info files", "maint print
2772 * The "target native" command now connects to the native target. This
2773 can be used to launch native programs even when "set
2774 auto-connect-native-target" is set to off.
2776 * GDB now supports access to Intel MPX registers on GNU/Linux.
2778 * Support for Intel AVX-512 registers on GNU/Linux.
2779 Support displaying and modifying Intel AVX-512 registers
2780 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2782 * New remote packets
2784 qXfer:btrace:read's annex
2785 The qXfer:btrace:read packet supports a new annex 'delta' to read
2786 branch trace incrementally.
2790 ** Valid Python operations on gdb.Value objects representing
2791 structs/classes invoke the corresponding overloaded operators if
2793 ** New `Xmethods' feature in the Python API. Xmethods are
2794 additional methods or replacements for existing methods of a C++
2795 class. This feature is useful for those cases where a method
2796 defined in C++ source code could be inlined or optimized out by
2797 the compiler, making it unavailable to GDB.
2800 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2802 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2803 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2804 its alias "share", instead.
2806 * The commands "set remotebaud" and "show remotebaud" are no longer
2807 supported. Use "set serial baud" and "show serial baud" (respectively)
2812 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2813 target-async". The latter is left as a deprecated alias of the
2814 former for backward compatibility. If the target supports it,
2815 CLI background execution commands are now always possible by
2816 default, independently of whether the frontend stated a
2817 preference for asynchronous execution with "-gdb-set mi-async".
2818 Previously "-gdb-set target-async off" affected both MI execution
2819 commands and CLI execution commands.
2821 *** Changes in GDB 7.7
2823 * Improved support for process record-replay and reverse debugging on
2824 arm*-linux* targets. Support for thumb32 and syscall instruction
2825 recording has been added.
2827 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2829 * GDB now supports Fission DWP file format version 2.
2830 http://gcc.gnu.org/wiki/DebugFission
2832 * New convenience function "$_isvoid", to check whether an expression
2833 is void. A void expression is an expression where the type of the
2834 result is "void". For example, some convenience variables may be
2835 "void" when evaluated (e.g., "$_exitcode" before the execution of
2836 the program being debugged; or an undefined convenience variable).
2837 Another example, when calling a function whose return type is
2840 * The "maintenance print objfiles" command now takes an optional regexp.
2842 * The "catch syscall" command now works on arm*-linux* targets.
2844 * GDB now consistently shows "<not saved>" when printing values of
2845 registers the debug info indicates have not been saved in the frame
2846 and there's nowhere to retrieve them from
2847 (callee-saved/call-clobbered registers):
2852 (gdb) info registers rax
2855 Before, the former would print "<optimized out>", and the latter
2856 "*value not available*".
2858 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2863 ** Frame filters and frame decorators have been added.
2864 ** Temporary breakpoints are now supported.
2865 ** Line tables representation has been added.
2866 ** New attribute 'parent_type' for gdb.Field objects.
2867 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2868 ** New attribute 'name' for gdb.Type objects.
2872 Nios II ELF nios2*-*-elf
2873 Nios II GNU/Linux nios2*-*-linux
2874 Texas Instruments MSP430 msp430*-*-elf
2876 * Removed native configurations
2878 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2879 been removed. ELF variants of these configurations are kept supported.
2881 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2882 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2883 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2884 i[34567]86-*-openbsd3.[0-3]
2885 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2886 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2887 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2891 Like "catch throw", but catches a re-thrown exception.
2892 maint check-psymtabs
2893 Renamed from old "maint check-symtabs".
2895 Perform consistency checks on symtabs.
2896 maint expand-symtabs
2897 Expand symtabs matching an optional regexp.
2900 Display the details of GDB configure-time options.
2902 maint set|show per-command
2903 maint set|show per-command space
2904 maint set|show per-command time
2905 maint set|show per-command symtab
2906 Enable display of per-command gdb resource usage.
2908 remove-symbol-file FILENAME
2909 remove-symbol-file -a ADDRESS
2910 Remove a symbol file added via add-symbol-file. The file to remove
2911 can be identified by its filename or by an address that lies within
2912 the boundaries of this symbol file in memory.
2915 info exceptions REGEXP
2916 Display the list of Ada exceptions defined in the program being
2917 debugged. If provided, only the exceptions whose names match REGEXP
2922 set debug symfile off|on
2924 Control display of debugging info regarding reading symbol files and
2925 symbol tables within those files
2927 set print raw frame-arguments
2928 show print raw frame-arguments
2929 Set/show whether to print frame arguments in raw mode,
2930 disregarding any defined pretty-printers.
2932 set remote trace-status-packet
2933 show remote trace-status-packet
2934 Set/show the use of remote protocol qTStatus packet.
2938 Control display of debugging messages related to Nios II targets.
2942 Control whether target-assisted range stepping is enabled.
2944 set startup-with-shell
2945 show startup-with-shell
2946 Specifies whether Unix child processes are started via a shell or
2951 Use the target memory cache for accesses to the code segment. This
2952 improves performance of remote debugging (particularly disassembly).
2954 * You can now use a literal value 'unlimited' for options that
2955 interpret 0 or -1 as meaning "unlimited". E.g., "set
2956 trace-buffer-size unlimited" is now an alias for "set
2957 trace-buffer-size -1" and "set height unlimited" is now an alias for
2960 * The "set debug symtab-create" debugging option of GDB has been changed to
2961 accept a verbosity level. 0 means "off", 1 provides basic debugging
2962 output, and values of 2 or greater provides more verbose output.
2964 * New command-line options
2966 Display the details of GDB configure-time options.
2968 * The command 'tsave' can now support new option '-ctf' to save trace
2969 buffer in Common Trace Format.
2971 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2974 * GDB now implements the C++ 'typeid' operator.
2976 * The new convenience variable $_exception holds the exception being
2977 thrown or caught at an exception-related catchpoint.
2979 * The exception-related catchpoints, like "catch throw", now accept a
2980 regular expression which can be used to filter exceptions by type.
2982 * The new convenience variable $_exitsignal is automatically set to
2983 the terminating signal number when the program being debugged dies
2984 due to an uncaught signal.
2988 ** All MI commands now accept an optional "--language" option.
2989 Support for this feature can be verified by using the "-list-features"
2990 command, which should contain "language-option".
2992 ** The new command -info-gdb-mi-command allows the user to determine
2993 whether a GDB/MI command is supported or not.
2995 ** The "^error" result record returned when trying to execute an undefined
2996 GDB/MI command now provides a variable named "code" whose content is the
2997 "undefined-command" error code. Support for this feature can be verified
2998 by using the "-list-features" command, which should contain
2999 "undefined-command-error-code".
3001 ** The -trace-save MI command can optionally save trace buffer in Common
3004 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3006 ** The command -data-list-register-values now accepts an optional
3007 "--skip-unavailable" option. When used, only the available registers
3010 ** The new command -trace-frame-collected dumps collected variables,
3011 computed expressions, tvars, memory and registers in a traceframe.
3013 ** The commands -stack-list-locals, -stack-list-arguments and
3014 -stack-list-variables now accept an option "--skip-unavailable".
3015 When used, only the available locals or arguments are displayed.
3017 ** The -exec-run command now accepts an optional "--start" option.
3018 When used, the command follows the same semantics as the "start"
3019 command, stopping the program's execution at the start of its
3020 main subprogram. Support for this feature can be verified using
3021 the "-list-features" command, which should contain
3022 "exec-run-start-option".
3024 ** The new commands -catch-assert and -catch-exceptions insert
3025 catchpoints stopping the program when Ada exceptions are raised.
3027 ** The new command -info-ada-exceptions provides the equivalent of
3028 the new "info exceptions" command.
3030 * New system-wide configuration scripts
3031 A GDB installation now provides scripts suitable for use as system-wide
3032 configuration scripts for the following systems:
3036 * GDB now supports target-assigned range stepping with remote targets.
3037 This improves the performance of stepping source lines by reducing
3038 the number of control packets from/to GDB. See "New remote packets"
3041 * GDB now understands the element 'tvar' in the XML traceframe info.
3042 It has the id of the collected trace state variables.
3044 * On S/390 targets that provide the transactional-execution feature,
3045 the program interruption transaction diagnostic block (TDB) is now
3046 represented as a number of additional "registers" in GDB.
3048 * New remote packets
3052 The vCont packet supports a new 'r' action, that tells the remote
3053 stub to step through an address range itself, without GDB
3054 involvemement at each single-step.
3056 qXfer:libraries-svr4:read's annex
3057 The previously unused annex of the qXfer:libraries-svr4:read packet
3058 is now used to support passing an argument list. The remote stub
3059 reports support for this argument list to GDB's qSupported query.
3060 The defined arguments are "start" and "prev", used to reduce work
3061 necessary for library list updating, resulting in significant
3064 * New features in the GDB remote stub, GDBserver
3066 ** GDBserver now supports target-assisted range stepping. Currently
3067 enabled on x86/x86_64 GNU/Linux targets.
3069 ** GDBserver now adds element 'tvar' in the XML in the reply to
3070 'qXfer:traceframe-info:read'. It has the id of the collected
3071 trace state variables.
3073 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3076 * New 'z' formatter for printing and examining memory, this displays the
3077 value as hexadecimal zero padded on the left to the size of the type.
3079 * GDB can now use Windows x64 unwinding data.
3081 * The "set remotebaud" command has been replaced by "set serial baud".
3082 Similarly, "show remotebaud" has been replaced by "show serial baud".
3083 The "set remotebaud" and "show remotebaud" commands are still available
3084 to provide backward compatibility with older versions of GDB.
3086 *** Changes in GDB 7.6
3088 * Target record has been renamed to record-full.
3089 Record/replay is now enabled with the "record full" command.
3090 This also affects settings that are associated with full record/replay
3091 that have been moved from "set/show record" to "set/show record full":
3093 set|show record full insn-number-max
3094 set|show record full stop-at-limit
3095 set|show record full memory-query
3097 * A new record target "record-btrace" has been added. The new target
3098 uses hardware support to record the control-flow of a process. It
3099 does not support replaying the execution, but it implements the
3100 below new commands for investigating the recorded execution log.
3101 This new recording method can be enabled using:
3105 The "record-btrace" target is only available on Intel Atom processors
3106 and requires a Linux kernel 2.6.32 or later.
3108 * Two new commands have been added for record/replay to give information
3109 about the recorded execution without having to replay the execution.
3110 The commands are only supported by "record btrace".
3112 record instruction-history prints the execution history at
3113 instruction granularity
3115 record function-call-history prints the execution history at
3116 function granularity
3118 * New native configurations
3120 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3121 FreeBSD/powerpc powerpc*-*-freebsd
3122 x86_64/Cygwin x86_64-*-cygwin*
3123 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3127 ARM AArch64 aarch64*-*-elf
3128 ARM AArch64 GNU/Linux aarch64*-*-linux
3129 Lynx 178 PowerPC powerpc-*-lynx*178
3130 x86_64/Cygwin x86_64-*-cygwin*
3131 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3133 * If the configured location of system.gdbinit file (as given by the
3134 --with-system-gdbinit option at configure time) is in the
3135 data-directory (as specified by --with-gdb-datadir at configure
3136 time) or in one of its subdirectories, then GDB will look for the
3137 system-wide init file in the directory specified by the
3138 --data-directory command-line option.
3140 * New command line options:
3142 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3143 other initialization files, unlike -nx which disables all of them.
3145 * Removed command line options
3147 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3150 * The 'ptype' and 'whatis' commands now accept an argument to control
3153 * 'info proc' now works on some core files.
3157 ** Vectors can be created with gdb.Type.vector.
3159 ** Python's atexit.register now works in GDB.
3161 ** Types can be pretty-printed via a Python API.
3163 ** Python 3 is now supported (in addition to Python 2.4 or later)
3165 ** New class gdb.Architecture exposes GDB's internal representation
3166 of architecture in the Python API.
3168 ** New method Frame.architecture returns the gdb.Architecture object
3169 corresponding to the frame's architecture.
3171 * New Python-based convenience functions:
3173 ** $_memeq(buf1, buf2, length)
3174 ** $_streq(str1, str2)
3176 ** $_regex(str, regex)
3178 * The 'cd' command now defaults to using '~' (the home directory) if not
3181 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3182 default for GCC since November 2000.
3184 * The command 'forward-search' can now be abbreviated as 'fo'.
3186 * The command 'info tracepoints' can now display 'installed on target'
3187 or 'not installed on target' for each non-pending location of tracepoint.
3189 * New configure options
3191 --enable-libmcheck/--disable-libmcheck
3192 By default, development versions are built with -lmcheck on hosts
3193 that support it, in order to help track memory corruption issues.
3194 Release versions, on the other hand, are built without -lmcheck
3195 by default. The --enable-libmcheck/--disable-libmcheck configure
3196 options allow the user to override that default.
3197 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3198 This configure option allows the user to build GDB with
3199 libbabeltrace using which GDB can read Common Trace Format data.
3201 * New commands (for set/show, see "New options" below)
3204 Catch signals. This is similar to "handle", but allows commands and
3205 conditions to be attached.
3208 List the BFDs known to GDB.
3210 python-interactive [command]
3212 Start a Python interactive prompt, or evaluate the optional command
3213 and print the result of expressions.
3216 "py" is a new alias for "python".
3218 enable type-printer [name]...
3219 disable type-printer [name]...
3220 Enable or disable type printers.
3224 ** For the Renesas Super-H architecture, the "regs" command has been removed
3225 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3230 set print type methods (on|off)
3231 show print type methods
3232 Control whether method declarations are displayed by "ptype".
3233 The default is to show them.
3235 set print type typedefs (on|off)
3236 show print type typedefs
3237 Control whether typedef definitions are displayed by "ptype".
3238 The default is to show them.
3240 set filename-display basename|relative|absolute
3241 show filename-display
3242 Control the way in which filenames is displayed.
3243 The default is "relative", which preserves previous behavior.
3245 set trace-buffer-size
3246 show trace-buffer-size
3247 Request target to change the size of trace buffer.
3249 set remote trace-buffer-size-packet auto|on|off
3250 show remote trace-buffer-size-packet
3251 Control the use of the remote protocol `QTBuffer:size' packet.
3255 Control display of debugging messages related to ARM AArch64.
3258 set debug coff-pe-read
3259 show debug coff-pe-read
3260 Control display of debugging messages related to reading of COFF/PE
3265 Control display of debugging messages related to Mach-O symbols
3268 set debug notification
3269 show debug notification
3270 Control display of debugging info for async remote notification.
3274 ** Command parameter changes are now notified using new async record
3275 "=cmd-param-changed".
3276 ** Trace frame changes caused by command "tfind" are now notified using
3277 new async record "=traceframe-changed".
3278 ** The creation, deletion and modification of trace state variables
3279 are now notified using new async records "=tsv-created",
3280 "=tsv-deleted" and "=tsv-modified".
3281 ** The start and stop of process record are now notified using new
3282 async record "=record-started" and "=record-stopped".
3283 ** Memory changes are now notified using new async record
3285 ** The data-disassemble command response will include a "fullname" field
3286 containing the absolute file name when source has been requested.
3287 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3288 command, to allow pattern filling of memory areas.
3289 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3290 library load/unload events.
3291 ** The response to breakpoint commands and breakpoint async records
3292 includes an "installed" field containing a boolean state about each
3293 non-pending tracepoint location is whether installed on target or not.
3294 ** Output of the "-trace-status" command includes a "trace-file" field
3295 containing the name of the trace file being examined. This field is
3296 optional, and only present when examining a trace file.
3297 ** The "fullname" field is now always present along with the "file" field,
3298 even if the file cannot be found by GDB.
3300 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3301 You must have the LZMA library available when configuring GDB for this
3302 feature to be enabled. For more information, see:
3303 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3305 * New remote packets
3308 Set the size of trace buffer. The remote stub reports support for this
3309 packet to gdb's qSupported query.
3312 Enable Branch Trace Store (BTS)-based branch tracing for the current
3313 thread. The remote stub reports support for this packet to gdb's
3317 Disable branch tracing for the current thread. The remote stub reports
3318 support for this packet to gdb's qSupported query.
3321 Read the traced branches for the current thread. The remote stub
3322 reports support for this packet to gdb's qSupported query.
3324 *** Changes in GDB 7.5
3326 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3327 for more x32 ABI info.
3329 * GDB now supports access to MIPS DSP registers on Linux targets.
3331 * GDB now supports debugging microMIPS binaries.
3333 * The "info os" command on GNU/Linux can now display information on
3334 several new classes of objects managed by the operating system:
3335 "info os procgroups" lists process groups
3336 "info os files" lists file descriptors
3337 "info os sockets" lists internet-domain sockets
3338 "info os shm" lists shared-memory regions
3339 "info os semaphores" lists semaphores
3340 "info os msg" lists message queues
3341 "info os modules" lists loaded kernel modules
3343 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3344 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3345 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3346 options and inspect the probe arguments using the new $_probe_arg family
3347 of convenience variables. You can obtain more information about SystemTap
3348 in <http://sourceware.org/systemtap/>.
3350 * GDB now supports reversible debugging on ARM, it allows you to
3351 debug basic ARM and THUMB instructions, and provides
3352 record/replay support.
3354 * The option "symbol-reloading" has been deleted as it is no longer used.
3358 ** GDB commands implemented in Python can now be put in command class
3361 ** The "maint set python print-stack on|off" is now deleted.
3363 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3364 apply "flag enum"-style pretty-printing to any enum.
3366 ** gdb.lookup_symbol can now work when there is no current frame.
3368 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3369 the source at which the symbol was defined.
3371 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3372 method 'value'. The former indicates whether the symbol needs a
3373 frame in order to compute its value, and the latter computes the
3376 ** A new method 'referenced_value' on gdb.Value objects which can
3377 dereference pointer as well as C++ reference values.
3379 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3380 which return the global and static blocks (as gdb.Block objects),
3381 of the underlying symbol table, respectively.
3383 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3384 object associated with a PC value.
3386 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3387 of the address range occupied by code for the current source line.
3389 * Go language support.
3390 GDB now supports debugging programs written in the Go programming
3393 * GDBserver now supports stdio connections.
3394 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3396 * The binary "gdbtui" can no longer be built or installed.
3397 Use "gdb -tui" instead.
3399 * GDB will now print "flag" enums specially. A flag enum is one where
3400 all the enumerator values have no bits in common when pairwise
3401 "and"ed. When printing a value whose type is a flag enum, GDB will
3402 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3403 (gdb) print (enum E) 3
3406 * The filename part of a linespec will now match trailing components
3407 of a source file name. For example, "break gcc/expr.c:1000" will
3408 now set a breakpoint in build/gcc/expr.c, but not
3409 build/libcpp/expr.c.
3411 * The "info proc" and "generate-core-file" commands will now also
3412 work on remote targets connected to GDBserver on Linux.
3414 * The command "info catch" has been removed. It has been disabled
3415 since December 2007.
3417 * The "catch exception" and "catch assert" commands now accept
3418 a condition at the end of the command, much like the "break"
3419 command does. For instance:
3421 (gdb) catch exception Constraint_Error if Barrier = True
3423 Previously, it was possible to add a condition to such catchpoints,
3424 but it had to be done as a second step, after the catchpoint had been
3425 created, using the "condition" command.
3427 * The "info static-tracepoint-marker" command will now also work on
3428 native Linux targets with in-process agent.
3430 * GDB can now set breakpoints on inlined functions.
3432 * The .gdb_index section has been updated to include symbols for
3433 inlined functions. GDB will ignore older .gdb_index sections by
3434 default, which could cause symbol files to be loaded more slowly
3435 until their .gdb_index sections can be recreated. The new command
3436 "set use-deprecated-index-sections on" will cause GDB to use any older
3437 .gdb_index sections it finds. This will restore performance, but the
3438 ability to set breakpoints on inlined functions will be lost in symbol
3439 files with older .gdb_index sections.
3441 The .gdb_index section has also been updated to record more information
3442 about each symbol. This speeds up the "info variables", "info functions"
3443 and "info types" commands when used with programs having the .gdb_index
3444 section, as well as speeding up debugging with shared libraries using
3445 the .gdb_index section.
3447 * Ada support for GDB/MI Variable Objects has been added.
3449 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3454 ** New command -info-os is the MI equivalent of "info os".
3456 ** Output logs ("set logging" and related) now include MI output.
3460 ** "set use-deprecated-index-sections on|off"
3461 "show use-deprecated-index-sections on|off"
3462 Controls the use of deprecated .gdb_index sections.
3464 ** "catch load" and "catch unload" can be used to stop when a shared
3465 library is loaded or unloaded, respectively.
3467 ** "enable count" can be used to auto-disable a breakpoint after
3470 ** "info vtbl" can be used to show the virtual method tables for
3471 C++ and Java objects.
3473 ** "explore" and its sub commands "explore value" and "explore type"
3474 can be used to recursively explore values and types of
3475 expressions. These commands are available only if GDB is
3476 configured with '--with-python'.
3478 ** "info auto-load" shows status of all kinds of auto-loaded files,
3479 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3480 sequences of commands files, "info auto-load python-scripts"
3481 shows status of auto-loading Python script files,
3482 "info auto-load local-gdbinit" shows status of loading init file
3483 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3484 status of inferior specific thread debugging shared library loading.
3486 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3487 and "show auto-load-scripts" commands have been deprecated, use their
3488 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3489 and "show auto-load python-scripts" counterparts instead.
3491 ** "dprintf location,format,args..." creates a dynamic printf, which
3492 is basically a breakpoint that does a printf and immediately
3493 resumes your program's execution, so it is like a printf that you
3494 can insert dynamically at runtime instead of at compiletime.
3496 ** "set print symbol"
3498 Controls whether GDB attempts to display the symbol, if any,
3499 corresponding to addresses it prints. This defaults to "on", but
3500 you can set it to "off" to restore GDB's previous behavior.
3502 * Deprecated commands
3504 ** For the Renesas Super-H architecture, the "regs" command has been
3505 deprecated, and "info all-registers" should be used instead.
3509 Renesas RL78 rl78-*-elf
3510 HP OpenVMS ia64 ia64-hp-openvms*
3512 * GDBserver supports evaluation of breakpoint conditions. When
3513 support is advertised by GDBserver, GDB may be told to send the
3514 breakpoint conditions in bytecode form to GDBserver. GDBserver
3515 will only report the breakpoint trigger to GDB when its condition
3520 set mips compression
3521 show mips compression
3522 Select the compressed ISA encoding used in functions that have no symbol
3523 information available. The encoding can be set to either of:
3526 and is updated automatically from ELF file flags if available.
3528 set breakpoint condition-evaluation
3529 show breakpoint condition-evaluation
3530 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3531 GDBserver ("target"). Default option "auto" chooses the most efficient
3533 This option can improve debugger efficiency depending on the speed of the
3537 Disable auto-loading globally.
3540 Show auto-loading setting of all kinds of auto-loaded files.
3542 set auto-load gdb-scripts on|off
3543 show auto-load gdb-scripts
3544 Control auto-loading of GDB canned sequences of commands files.
3546 set auto-load python-scripts on|off
3547 show auto-load python-scripts
3548 Control auto-loading of Python script files.
3550 set auto-load local-gdbinit on|off
3551 show auto-load local-gdbinit
3552 Control loading of init file (.gdbinit) from current directory.
3554 set auto-load libthread-db on|off
3555 show auto-load libthread-db
3556 Control auto-loading of inferior specific thread debugging shared library.
3558 set auto-load scripts-directory <dir1>[:<dir2>...]
3559 show auto-load scripts-directory
3560 Set a list of directories from which to load auto-loaded scripts.
3561 Automatically loaded Python scripts and GDB scripts are located in one
3562 of the directories listed by this option.
3563 The delimiter (':' above) may differ according to the host platform.
3565 set auto-load safe-path <dir1>[:<dir2>...]
3566 show auto-load safe-path
3567 Set a list of directories from which it is safe to auto-load files.
3568 The delimiter (':' above) may differ according to the host platform.
3570 set debug auto-load on|off
3571 show debug auto-load
3572 Control display of debugging info for auto-loading the files above.
3574 set dprintf-style gdb|call|agent
3576 Control the way in which a dynamic printf is performed; "gdb"
3577 requests a GDB printf command, while "call" causes dprintf to call a
3578 function in the inferior. "agent" requests that the target agent
3579 (such as GDBserver) do the printing.
3581 set dprintf-function <expr>
3582 show dprintf-function
3583 set dprintf-channel <expr>
3584 show dprintf-channel
3585 Set the function and optional first argument to the call when using
3586 the "call" style of dynamic printf.
3588 set disconnected-dprintf on|off
3589 show disconnected-dprintf
3590 Control whether agent-style dynamic printfs continue to be in effect
3591 after GDB disconnects.
3593 * New configure options
3595 --with-auto-load-dir
3596 Configure default value for the 'set auto-load scripts-directory'
3597 setting above. It defaults to '$debugdir:$datadir/auto-load',
3598 $debugdir representing global debugging info directories (available
3599 via 'show debug-file-directory') and $datadir representing GDB's data
3600 directory (available via 'show data-directory').
3602 --with-auto-load-safe-path
3603 Configure default value for the 'set auto-load safe-path' setting
3604 above. It defaults to the --with-auto-load-dir setting.
3606 --without-auto-load-safe-path
3607 Set 'set auto-load safe-path' to '/', effectively disabling this
3610 * New remote packets
3612 z0/z1 conditional breakpoints extension
3614 The z0/z1 breakpoint insertion packets have been extended to carry
3615 a list of conditional expressions over to the remote stub depending on the
3616 condition evaluation mode. The use of this extension can be controlled
3617 via the "set remote conditional-breakpoints-packet" command.
3621 Specify the signals which the remote stub may pass to the debugged
3622 program without GDB involvement.
3624 * New command line options
3626 --init-command=FILE, -ix Like --command, -x but execute it
3627 before loading inferior.
3628 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3629 execute it before loading inferior.
3631 *** Changes in GDB 7.4
3633 * GDB now handles ambiguous linespecs more consistently; the existing
3634 FILE:LINE support has been expanded to other types of linespecs. A
3635 breakpoint will now be set on all matching locations in all
3636 inferiors, and locations will be added or removed according to
3639 * GDB now allows you to skip uninteresting functions and files when
3640 stepping with the "skip function" and "skip file" commands.
3642 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3643 and "show remote hardware-watchpoint-length-limit". These allows to
3644 set or show the maximum length limit (in bytes) of a remote
3645 target hardware watchpoint.
3647 This allows e.g. to use "unlimited" hardware watchpoints with the
3648 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3649 watchpoints are slower than real hardware watchpoints but are
3650 significantly faster than gdb software watchpoints.
3654 ** The register_pretty_printer function in module gdb.printing now takes
3655 an optional `replace' argument. If True, the new printer replaces any
3658 ** The "maint set python print-stack on|off" command has been
3659 deprecated and will be deleted in GDB 7.5.
3660 A new command: "set python print-stack none|full|message" has
3661 replaced it. Additionally, the default for "print-stack" is
3662 now "message", which just prints the error message without
3665 ** A prompt substitution hook (prompt_hook) is now available to the
3668 ** A new Python module, gdb.prompt has been added to the GDB Python
3669 modules library. This module provides functionality for
3670 escape sequences in prompts (used by set/show
3671 extended-prompt). These escape sequences are replaced by their
3672 corresponding value.
3674 ** Python commands and convenience-functions located in
3675 'data-directory'/python/gdb/command and
3676 'data-directory'/python/gdb/function are now automatically loaded
3679 ** Blocks now provide four new attributes. global_block and
3680 static_block will return the global and static blocks
3681 respectively. is_static and is_global are boolean attributes
3682 that indicate if the block is one of those two types.
3684 ** Symbols now provide the "type" attribute, the type of the symbol.
3686 ** The "gdb.breakpoint" function has been deprecated in favor of
3689 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3690 of a function. This class is based on the "finish" command
3691 available in the CLI.
3693 ** Type objects for struct and union types now allow access to
3694 the fields using standard Python dictionary (mapping) methods.
3695 For example, "some_type['myfield']" now works, as does
3696 "some_type.items()".
3698 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3701 ** A new function, "deep_items" has been added to the gdb.types
3702 module in the GDB Python modules library. This function returns
3703 an iterator over the fields of a struct or union type. Unlike
3704 the standard Python "iteritems" method, it will recursively traverse
3705 any anonymous fields.
3709 ** "*stopped" events can report several new "reason"s, such as
3712 ** Breakpoint changes are now notified using new async records, like
3713 "=breakpoint-modified".
3715 ** New command -ada-task-info.
3717 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3718 $sdir specifies the default system locations of shared libraries.
3719 $pdir specifies the directory where the libpthread used by the application
3722 GDB no longer looks in $sdir and $pdir after it has searched the directories
3723 mentioned in libthread-db-search-path. If you want to search those
3724 directories, they must be specified in libthread-db-search-path.
3725 The default value of libthread-db-search-path on GNU/Linux and Solaris
3726 systems is now "$sdir:$pdir".
3728 $pdir is not supported by gdbserver, it is currently ignored.
3729 $sdir is supported by gdbserver.
3731 * New configure option --with-iconv-bin.
3732 When using the internationalization support like the one in the GNU C
3733 library, GDB will invoke the "iconv" program to get a list of supported
3734 character sets. If this program lives in a non-standard location, one can
3735 use this option to specify where to find it.
3737 * When natively debugging programs on PowerPC BookE processors running
3738 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3739 watchpoints, which specify a mask in addition to an address to watch.
3740 The mask specifies that some bits of an address (the bits which are
3741 reset in the mask) should be ignored when matching the address accessed
3742 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3743 section in the user manual for more details.
3745 * The new option --once causes GDBserver to stop listening for connections once
3746 the first connection is made. The listening port used by GDBserver will
3747 become available after that.
3749 * New commands "info macros" and "alias" have been added.
3751 * New function parameters suffix @entry specifies value of function parameter
3752 at the time the function got called. Entry values are available only since
3758 "!" is now an alias of the "shell" command.
3759 Note that no space is needed between "!" and SHELL COMMAND.
3763 watch EXPRESSION mask MASK_VALUE
3764 The watch command now supports the mask argument which allows creation
3765 of masked watchpoints, if the current architecture supports this feature.
3767 info auto-load-scripts [REGEXP]
3768 This command was formerly named "maintenance print section-scripts".
3769 It is now generally useful and is no longer a maintenance-only command.
3771 info macro [-all] [--] MACRO
3772 The info macro command has new options `-all' and `--'. The first for
3773 printing all definitions of a macro. The second for explicitly specifying
3774 the end of arguments and the beginning of the macro name in case the macro
3775 name starts with a hyphen.
3777 collect[/s] EXPRESSIONS
3778 The tracepoint collect command now takes an optional modifier "/s"
3779 that directs it to dereference pointer-to-character types and
3780 collect the bytes of memory up to a zero byte. The behavior is
3781 similar to what you see when you use the regular print command on a
3782 string. An optional integer following the "/s" sets a bound on the
3783 number of bytes that will be collected.
3786 The trace start command now interprets any supplied arguments as a
3787 note to be recorded with the trace run, with an effect similar to
3788 setting the variable trace-notes.
3791 The trace stop command now interprets any arguments as a note to be
3792 mentioned along with the tstatus report that the trace was stopped
3793 with a command. The effect is similar to setting the variable
3796 * Tracepoints can now be enabled and disabled at any time after a trace
3797 experiment has been started using the standard "enable" and "disable"
3798 commands. It is now possible to start a trace experiment with no enabled
3799 tracepoints; GDB will display a warning, but will allow the experiment to
3800 begin, assuming that tracepoints will be enabled as needed while the trace
3803 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3804 locations with 4-byte instructions, when they were previously
3805 limited to locations with instructions of 5 bytes or longer.
3809 set debug dwarf2-read
3810 show debug dwarf2-read
3811 Turns on or off display of debugging messages related to reading
3812 DWARF debug info. The default is off.
3814 set debug symtab-create
3815 show debug symtab-create
3816 Turns on or off display of debugging messages related to symbol table
3817 creation. The default is off.
3820 show extended-prompt
3821 Set the GDB prompt, and allow escape sequences to be inserted to
3822 display miscellaneous information (see 'help set extended-prompt'
3823 for the list of sequences). This prompt (and any information
3824 accessed through the escape sequences) is updated every time the
3825 prompt is displayed.
3827 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3828 show print entry-values
3829 Set printing of frame argument values at function entry. In some cases
3830 GDB can determine the value of function argument which was passed by the
3831 function caller, even if the value was modified inside the called function.
3833 set debug entry-values
3834 show debug entry-values
3835 Control display of debugging info for determining frame argument values at
3836 function entry and virtual tail call frames.
3838 set basenames-may-differ
3839 show basenames-may-differ
3840 Set whether a source file may have multiple base names.
3841 (A "base name" is the name of a file with the directory part removed.
3842 Example: The base name of "/home/user/hello.c" is "hello.c".)
3843 If set, GDB will canonicalize file names (e.g., expand symlinks)
3844 before comparing them. Canonicalization is an expensive operation,
3845 but it allows the same file be known by more than one base name.
3846 If not set (the default), all source files are assumed to have just
3847 one base name, and gdb will do file name comparisons more efficiently.
3853 Set a user name and notes for the current and any future trace runs.
3854 This is useful for long-running and/or disconnected traces, to
3855 inform others (or yourself) as to who is running the trace, supply
3856 contact information, or otherwise explain what is going on.
3858 set trace-stop-notes
3859 show trace-stop-notes
3860 Set a note attached to the trace run, that is displayed when the
3861 trace has been stopped by a tstop command. This is useful for
3862 instance as an explanation, if you are stopping a trace run that was
3863 started by someone else.
3865 * New remote packets
3869 Dynamically enable a tracepoint in a started trace experiment.
3873 Dynamically disable a tracepoint in a started trace experiment.
3877 Set the user and notes of the trace run.
3881 Query the current status of a tracepoint.
3885 Query the minimum length of instruction at which a fast tracepoint may
3888 * Dcache size (number of lines) and line-size are now runtime-configurable
3889 via "set dcache line" and "set dcache line-size" commands.
3893 Texas Instruments TMS320C6x tic6x-*-*
3897 Renesas RL78 rl78-*-elf
3899 *** Changes in GDB 7.3.1
3901 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3903 *** Changes in GDB 7.3
3905 * GDB has a new command: "thread find [REGEXP]".
3906 It finds the thread id whose name, target id, or thread extra info
3907 matches the given regular expression.
3909 * The "catch syscall" command now works on mips*-linux* targets.
3911 * The -data-disassemble MI command now supports modes 2 and 3 for
3912 dumping the instruction opcodes.
3914 * New command line options
3916 -data-directory DIR Specify DIR as the "data-directory".
3917 This is mostly for testing purposes.
3919 * The "maint set python auto-load on|off" command has been renamed to
3920 "set auto-load-scripts on|off".
3922 * GDB has a new command: "set directories".
3923 It is like the "dir" command except that it replaces the
3924 source path list instead of augmenting it.
3926 * GDB now understands thread names.
3928 On GNU/Linux, "info threads" will display the thread name as set by
3929 prctl or pthread_setname_np.
3931 There is also a new command, "thread name", which can be used to
3932 assign a name internally for GDB to display.
3935 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3936 has been integrated into GDB.
3940 ** The function gdb.Write now accepts an optional keyword 'stream'.
3941 This keyword, when provided, will direct the output to either
3942 stdout, stderr, or GDB's logging output.
3944 ** Parameters can now be be sub-classed in Python, and in particular
3945 you may implement the get_set_doc and get_show_doc functions.
3946 This improves how Parameter set/show documentation is processed
3947 and allows for more dynamic content.
3949 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3950 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3951 have an is_valid method.
3953 ** Breakpoints can now be sub-classed in Python, and in particular
3954 you may implement a 'stop' function that is executed each time
3955 the inferior reaches that breakpoint.
3957 ** New function gdb.lookup_global_symbol looks up a global symbol.
3959 ** GDB values in Python are now callable if the value represents a
3960 function. For example, if 'some_value' represents a function that
3961 takes two integer parameters and returns a value, you can call
3962 that function like so:
3964 result = some_value (10,20)
3966 ** Module gdb.types has been added.
3967 It contains a collection of utilities for working with gdb.Types objects:
3968 get_basic_type, has_field, make_enum_dict.
3970 ** Module gdb.printing has been added.
3971 It contains utilities for writing and registering pretty-printers.
3972 New classes: PrettyPrinter, SubPrettyPrinter,
3973 RegexpCollectionPrettyPrinter.
3974 New function: register_pretty_printer.
3976 ** New commands "info pretty-printers", "enable pretty-printer" and
3977 "disable pretty-printer" have been added.
3979 ** gdb.parameter("directories") is now available.
3981 ** New function gdb.newest_frame returns the newest frame in the
3984 ** The gdb.InferiorThread class has a new "name" attribute. This
3985 holds the thread's name.
3987 ** Python Support for Inferior events.
3988 Python scripts can add observers to be notified of events
3989 occurring in the process being debugged.
3990 The following events are currently supported:
3991 - gdb.events.cont Continue event.
3992 - gdb.events.exited Inferior exited event.
3993 - gdb.events.stop Signal received, and Breakpoint hit events.
3997 ** GDB now puts template parameters in scope when debugging in an
3998 instantiation. For example, if you have:
4000 template<int X> int func (void) { return X; }
4002 then if you step into func<5>, "print X" will show "5". This
4003 feature requires proper debuginfo support from the compiler; it
4004 was added to GCC 4.5.
4006 ** The motion commands "next", "finish", "until", and "advance" now
4007 work better when exceptions are thrown. In particular, GDB will
4008 no longer lose control of the inferior; instead, the GDB will
4009 stop the inferior at the point at which the exception is caught.
4010 This functionality requires a change in the exception handling
4011 code that was introduced in GCC 4.5.
4013 * GDB now follows GCC's rules on accessing volatile objects when
4014 reading or writing target state during expression evaluation.
4015 One notable difference to prior behavior is that "print x = 0"
4016 no longer generates a read of x; the value of the assignment is
4017 now always taken directly from the value being assigned.
4019 * GDB now has some support for using labels in the program's source in
4020 linespecs. For instance, you can use "advance label" to continue
4021 execution to a label.
4023 * GDB now has support for reading and writing a new .gdb_index
4024 section. This section holds a fast index of DWARF debugging
4025 information and can be used to greatly speed up GDB startup and
4026 operation. See the documentation for `save gdb-index' for details.
4028 * The "watch" command now accepts an optional "-location" argument.
4029 When used, this causes GDB to watch the memory referred to by the
4030 expression. Such a watchpoint is never deleted due to it going out
4033 * GDB now supports thread debugging of core dumps on GNU/Linux.
4035 GDB now activates thread debugging using the libthread_db library
4036 when debugging GNU/Linux core dumps, similarly to when debugging
4037 live processes. As a result, when debugging a core dump file, GDB
4038 is now able to display pthread_t ids of threads. For example, "info
4039 threads" shows the same output as when debugging the process when it
4040 was live. In earlier releases, you'd see something like this:
4043 * 1 LWP 6780 main () at main.c:10
4045 While now you see this:
4048 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4050 It is also now possible to inspect TLS variables when debugging core
4053 When debugging a core dump generated on a machine other than the one
4054 used to run GDB, you may need to point GDB at the correct
4055 libthread_db library with the "set libthread-db-search-path"
4056 command. See the user manual for more details on this command.
4058 * When natively debugging programs on PowerPC BookE processors running
4059 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4060 which stop execution of the inferior whenever it executes an instruction
4061 at any address within the specified range. See the "PowerPC Embedded"
4062 section in the user manual for more details.
4064 * New features in the GDB remote stub, GDBserver
4066 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4067 and i686 LynxOS (version 5.x).
4069 ** GDBserver is now supported on Blackfin Linux.
4071 * New native configurations
4073 ia64 HP-UX ia64-*-hpux*
4077 Analog Devices, Inc. Blackfin Processor bfin-*
4079 * Ada task switching is now supported on sparc-elf targets when
4080 debugging a program using the Ravenscar Profile. For more information,
4081 see the "Tasking Support when using the Ravenscar Profile" section
4082 in the GDB user manual.
4084 * Guile support was removed.
4086 * New features in the GNU simulator
4088 ** The --map-info flag lists all known core mappings.
4090 ** CFI flashes may be simulated via the "cfi" device.
4092 *** Changes in GDB 7.2
4094 * Shared library support for remote targets by default
4096 When GDB is configured for a generic, non-OS specific target, like
4097 for example, --target=arm-eabi or one of the many *-*-elf targets,
4098 GDB now queries remote stubs for loaded shared libraries using the
4099 `qXfer:libraries:read' packet. Previously, shared library support
4100 was always disabled for such configurations.
4104 ** Argument Dependent Lookup (ADL)
4106 In C++ ADL lookup directs function search to the namespaces of its
4107 arguments even if the namespace has not been imported.
4117 Here the compiler will search for `foo' in the namespace of 'b'
4118 and find A::foo. GDB now supports this. This construct is commonly
4119 used in the Standard Template Library for operators.
4121 ** Improved User Defined Operator Support
4123 In addition to member operators, GDB now supports lookup of operators
4124 defined in a namespace and imported with a `using' directive, operators
4125 defined in the global scope, operators imported implicitly from an
4126 anonymous namespace, and the ADL operators mentioned in the previous
4128 GDB now also supports proper overload resolution for all the previously
4129 mentioned flavors of operators.
4131 ** static const class members
4133 Printing of static const class members that are initialized in the
4134 class definition has been fixed.
4136 * Windows Thread Information Block access.
4138 On Windows targets, GDB now supports displaying the Windows Thread
4139 Information Block (TIB) structure. This structure is visible either
4140 by using the new command `info w32 thread-information-block' or, by
4141 dereferencing the new convenience variable named `$_tlb', a
4142 thread-specific pointer to the TIB. This feature is also supported
4143 when remote debugging using GDBserver.
4145 * Static tracepoints
4147 Static tracepoints are calls in the user program into a tracing
4148 library. One such library is a port of the LTTng kernel tracer to
4149 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4150 When debugging with GDBserver, GDB now supports combining the GDB
4151 tracepoint machinery with such libraries. For example: the user can
4152 use GDB to probe a static tracepoint marker (a call from the user
4153 program into the tracing library) with the new "strace" command (see
4154 "New commands" below). This creates a "static tracepoint" in the
4155 breakpoint list, that can be manipulated with the same feature set
4156 as fast and regular tracepoints. E.g., collect registers, local and
4157 global variables, collect trace state variables, and define
4158 tracepoint conditions. In addition, the user can collect extra
4159 static tracepoint marker specific data, by collecting the new
4160 $_sdata internal variable. When analyzing the trace buffer, you can
4161 inspect $_sdata like any other variable available to GDB. For more
4162 information, see the "Tracepoints" chapter in GDB user manual. New
4163 remote packets have been defined to support static tracepoints, see
4164 the "New remote packets" section below.
4166 * Better reconstruction of tracepoints after disconnected tracing
4168 GDB will attempt to download the original source form of tracepoint
4169 definitions when starting a trace run, and then will upload these
4170 upon reconnection to the target, resulting in a more accurate
4171 reconstruction of the tracepoints that are in use on the target.
4175 You can now exercise direct control over the ways that GDB can
4176 affect your program. For instance, you can disallow the setting of
4177 breakpoints, so that the program can run continuously (assuming
4178 non-stop mode). In addition, the "observer" variable is available
4179 to switch all of the different controls; in observer mode, GDB
4180 cannot affect the target's behavior at all, which is useful for
4181 tasks like diagnosing live systems in the field.
4183 * The new convenience variable $_thread holds the number of the
4186 * New remote packets
4190 Return the address of the Windows Thread Information Block of a given thread.
4194 In response to several of the tracepoint packets, the target may now
4195 also respond with a number of intermediate `qRelocInsn' request
4196 packets before the final result packet, to have GDB handle
4197 relocating an instruction to execute at a different address. This
4198 is particularly useful for stubs that support fast tracepoints. GDB
4199 reports support for this feature in the qSupported packet.
4203 List static tracepoint markers in the target program.
4207 List static tracepoint markers at a given address in the target
4210 qXfer:statictrace:read
4212 Read the static trace data collected (by a `collect $_sdata'
4213 tracepoint action). The remote stub reports support for this packet
4214 to gdb's qSupported query.
4218 Send the current settings of GDB's permission flags.
4222 Send part of the source (textual) form of a tracepoint definition,
4223 which includes location, conditional, and action list.
4225 * The source command now accepts a -s option to force searching for the
4226 script in the source search path even if the script name specifies
4229 * New features in the GDB remote stub, GDBserver
4231 - GDBserver now support tracepoints (including fast tracepoints, and
4232 static tracepoints). The feature is currently supported by the
4233 i386-linux and amd64-linux builds. See the "Tracepoints support
4234 in gdbserver" section in the manual for more information.
4236 GDBserver JIT compiles the tracepoint's conditional agent
4237 expression bytecode into native code whenever possible for low
4238 overhead dynamic tracepoints conditionals. For such tracepoints,
4239 an expression that examines program state is evaluated when the
4240 tracepoint is reached, in order to determine whether to capture
4241 trace data. If the condition is simple and false, processing the
4242 tracepoint finishes very quickly and no data is gathered.
4244 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4245 for static tracepoints support.
4247 - GDBserver now supports x86_64 Windows 64-bit debugging.
4249 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4250 it understands register description.
4252 * The --batch flag now disables pagination and queries.
4254 * X86 general purpose registers
4256 GDB now supports reading/writing byte, word and double-word x86
4257 general purpose registers directly. This means you can use, say,
4258 $ah or $ax to refer, respectively, to the byte register AH and
4259 16-bit word register AX that are actually portions of the 32-bit
4260 register EAX or 64-bit register RAX.
4262 * The `commands' command now accepts a range of breakpoints to modify.
4263 A plain `commands' following a command that creates multiple
4264 breakpoints affects all the breakpoints set by that command. This
4265 applies to breakpoints set by `rbreak', and also applies when a
4266 single `break' command creates multiple breakpoints (e.g.,
4267 breakpoints on overloaded c++ functions).
4269 * The `rbreak' command now accepts a filename specification as part of
4270 its argument, limiting the functions selected by the regex to those
4271 in the specified file.
4273 * Support for remote debugging Windows and SymbianOS shared libraries
4274 from Unix hosts has been improved. Non Windows GDB builds now can
4275 understand target reported file names that follow MS-DOS based file
4276 system semantics, such as file names that include drive letters and
4277 use the backslash character as directory separator. This makes it
4278 possible to transparently use the "set sysroot" and "set
4279 solib-search-path" on Unix hosts to point as host copies of the
4280 target's shared libraries. See the new command "set
4281 target-file-system-kind" described below, and the "Commands to
4282 specify files" section in the user manual for more information.
4286 eval template, expressions...
4287 Convert the values of one or more expressions under the control
4288 of the string template to a command line, and call it.
4290 set target-file-system-kind unix|dos-based|auto
4291 show target-file-system-kind
4292 Set or show the assumed file system kind for target reported file
4295 save breakpoints <filename>
4296 Save all current breakpoint definitions to a file suitable for use
4297 in a later debugging session. To read the saved breakpoint
4298 definitions, use the `source' command.
4300 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4303 info static-tracepoint-markers
4304 Display information about static tracepoint markers in the target.
4306 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4307 Define a static tracepoint by probing a marker at the given
4308 function, line, address, or marker ID.
4312 Enable and disable observer mode.
4314 set may-write-registers on|off
4315 set may-write-memory on|off
4316 set may-insert-breakpoints on|off
4317 set may-insert-tracepoints on|off
4318 set may-insert-fast-tracepoints on|off
4319 set may-interrupt on|off
4320 Set individual permissions for GDB effects on the target. Note that
4321 some of these settings can have undesirable or surprising
4322 consequences, particularly when changed in the middle of a session.
4323 For instance, disabling the writing of memory can prevent
4324 breakpoints from being inserted, cause single-stepping to fail, or
4325 even crash your program, if you disable after breakpoints have been
4326 inserted. However, GDB should not crash.
4328 set record memory-query on|off
4329 show record memory-query
4330 Control whether to stop the inferior if memory changes caused
4331 by an instruction cannot be recorded.
4336 The disassemble command now supports "start,+length" form of two arguments.
4340 ** GDB now provides a new directory location, called the python directory,
4341 where Python scripts written for GDB can be installed. The location
4342 of that directory is <data-directory>/python, where <data-directory>
4343 is the GDB data directory. For more details, see section `Scripting
4344 GDB using Python' in the manual.
4346 ** The GDB Python API now has access to breakpoints, symbols, symbol
4347 tables, program spaces, inferiors, threads and frame's code blocks.
4348 Additionally, GDB Parameters can now be created from the API, and
4349 manipulated via set/show in the CLI.
4351 ** New functions gdb.target_charset, gdb.target_wide_charset,
4352 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4354 ** New exception gdb.GdbError.
4356 ** Pretty-printers are now also looked up in the current program space.
4358 ** Pretty-printers can now be individually enabled and disabled.
4360 ** GDB now looks for names of Python scripts to auto-load in a
4361 special section named `.debug_gdb_scripts', in addition to looking
4362 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4364 * Tracepoint actions were unified with breakpoint commands. In particular,
4365 there are no longer differences in "info break" output for breakpoints and
4366 tracepoints and the "commands" command can be used for both tracepoints and
4367 regular breakpoints.
4371 ARM Symbian arm*-*-symbianelf*
4373 * D language support.
4374 GDB now supports debugging programs written in the D programming
4377 * GDB now supports the extended ptrace interface for PowerPC which is
4378 available since Linux kernel version 2.6.34. This automatically enables
4379 any hardware breakpoints and additional hardware watchpoints available in
4380 the processor. The old ptrace interface exposes just one hardware
4381 watchpoint and no hardware breakpoints.
4383 * GDB is now able to use the Data Value Compare (DVC) register available on
4384 embedded PowerPC processors to implement in hardware simple watchpoint
4385 conditions of the form:
4387 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4389 This works in native GDB running on Linux kernels with the extended ptrace
4390 interface mentioned above.
4392 *** Changes in GDB 7.1
4396 ** Namespace Support
4398 GDB now supports importing of namespaces in C++. This enables the
4399 user to inspect variables from imported namespaces. Support for
4400 namepace aliasing has also been added. So, if a namespace is
4401 aliased in the current scope (e.g. namepace C=A; ) the user can
4402 print variables using the alias (e.g. (gdb) print C::x).
4406 All known bugs relating to the printing of virtual base class were
4407 fixed. It is now possible to call overloaded static methods using a
4412 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4413 and reinterpret_cast<> are now handled by the C++ expression parser.
4417 Xilinx MicroBlaze microblaze-*-*
4422 Xilinx MicroBlaze microblaze
4425 * Multi-program debugging.
4427 GDB now has support for multi-program (a.k.a. multi-executable or
4428 multi-exec) debugging. This allows for debugging multiple inferiors
4429 simultaneously each running a different program under the same GDB
4430 session. See "Debugging Multiple Inferiors and Programs" in the
4431 manual for more information. This implied some user visible changes
4432 in the multi-inferior support. For example, "info inferiors" now
4433 lists inferiors that are not running yet or that have exited
4434 already. See also "New commands" and "New options" below.
4436 * New tracing features
4438 GDB's tracepoint facility now includes several new features:
4440 ** Trace state variables
4442 GDB tracepoints now include support for trace state variables, which
4443 are variables managed by the target agent during a tracing
4444 experiment. They are useful for tracepoints that trigger each
4445 other, so for instance one tracepoint can count hits in a variable,
4446 and then a second tracepoint has a condition that is true when the
4447 count reaches a particular value. Trace state variables share the
4448 $-syntax of GDB convenience variables, and can appear in both
4449 tracepoint actions and condition expressions. Use the "tvariable"
4450 command to create, and "info tvariables" to view; see "Trace State
4451 Variables" in the manual for more detail.
4455 GDB now includes an option for defining fast tracepoints, which
4456 targets may implement more efficiently, such as by installing a jump
4457 into the target agent rather than a trap instruction. The resulting
4458 speedup can be by two orders of magnitude or more, although the
4459 tradeoff is that some program locations on some target architectures
4460 might not allow fast tracepoint installation, for instance if the
4461 instruction to be replaced is shorter than the jump. To request a
4462 fast tracepoint, use the "ftrace" command, with syntax identical to
4463 the regular trace command.
4465 ** Disconnected tracing
4467 It is now possible to detach GDB from the target while it is running
4468 a trace experiment, then reconnect later to see how the experiment
4469 is going. In addition, a new variable disconnected-tracing lets you
4470 tell the target agent whether to continue running a trace if the
4471 connection is lost unexpectedly.
4475 GDB now has the ability to save the trace buffer into a file, and
4476 then use that file as a target, similarly to you can do with
4477 corefiles. You can select trace frames, print data that was
4478 collected in them, and use tstatus to display the state of the
4479 tracing run at the moment that it was saved. To create a trace
4480 file, use "tsave <filename>", and to use it, do "target tfile
4483 ** Circular trace buffer
4485 You can ask the target agent to handle the trace buffer as a
4486 circular buffer, discarding the oldest trace frames to make room for
4487 newer ones, by setting circular-trace-buffer to on. This feature may
4488 not be available for all target agents.
4493 The disassemble command, when invoked with two arguments, now requires
4494 the arguments to be comma-separated.
4497 The info variables command now displays variable definitions. Files
4498 which only declare a variable are not shown.
4501 The source command is now capable of sourcing Python scripts.
4502 This feature is dependent on the debugger being build with Python
4505 Related to this enhancement is also the introduction of a new command
4506 "set script-extension" (see below).
4508 * New commands (for set/show, see "New options" below)
4510 record save [<FILENAME>]
4511 Save a file (in core file format) containing the process record
4512 execution log for replay debugging at a later time.
4514 record restore <FILENAME>
4515 Restore the process record execution log that was saved at an
4516 earlier time, for replay debugging.
4518 add-inferior [-copies <N>] [-exec <FILENAME>]
4521 clone-inferior [-copies <N>] [ID]
4522 Make a new inferior ready to execute the same program another
4523 inferior has loaded.
4528 maint info program-spaces
4529 List the program spaces loaded into GDB.
4531 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4532 show remote interrupt-sequence
4533 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4534 as the sequence to the remote target in order to interrupt the execution.
4535 Ctrl-C is a default. Some system prefers BREAK which is high level of
4536 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4537 Magic SysRq g. It is BREAK signal and character 'g'.
4539 set remote interrupt-on-connect [on | off]
4540 show remote interrupt-on-connect
4541 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4542 remote target when gdb connects to it. This is needed when you debug
4545 set remotebreak [on | off]
4547 Deprecated. Use "set/show remote interrupt-sequence" instead.
4549 tvariable $NAME [ = EXP ]
4550 Create or modify a trace state variable.
4553 List trace state variables and their values.
4555 delete tvariable $NAME ...
4556 Delete one or more trace state variables.
4559 Evaluate the given expressions without collecting anything into the
4560 trace buffer. (Valid in tracepoint actions only.)
4562 ftrace FN / FILE:LINE / *ADDR
4563 Define a fast tracepoint at the given function, line, or address.
4565 * New expression syntax
4567 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4568 GDB now parses 0b101010 identically with 42.
4572 set follow-exec-mode new|same
4573 show follow-exec-mode
4574 Control whether GDB reuses the same inferior across an exec call or
4575 creates a new one. This is useful to be able to restart the old
4576 executable after the inferior having done an exec call.
4578 set default-collect EXPR, ...
4579 show default-collect
4580 Define a list of expressions to be collected at each tracepoint.
4581 This is a useful way to ensure essential items are not overlooked,
4582 such as registers or a critical global variable.
4584 set disconnected-tracing
4585 show disconnected-tracing
4586 If set to 1, the target is instructed to continue tracing if it
4587 loses its connection to GDB. If 0, the target is to stop tracing
4590 set circular-trace-buffer
4591 show circular-trace-buffer
4592 If set to on, the target is instructed to use a circular trace buffer
4593 and discard the oldest trace frames instead of stopping the trace due
4594 to a full trace buffer. If set to off, the trace stops when the buffer
4595 fills up. Some targets may not support this.
4597 set script-extension off|soft|strict
4598 show script-extension
4599 If set to "off", the debugger does not perform any script language
4600 recognition, and all sourced files are assumed to be GDB scripts.
4601 If set to "soft" (the default), files are sourced according to
4602 filename extension, falling back to GDB scripts if the first
4604 If set to "strict", files are sourced according to filename extension.
4606 set ada trust-PAD-over-XVS on|off
4607 show ada trust-PAD-over-XVS
4608 If off, activate a workaround against a bug in the debugging information
4609 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4610 the GCC sources for more information about the GNAT encoding and
4611 PAD types in particular). It is always safe to set this option to
4612 off, but this introduces a slight performance penalty. The default
4615 * Python API Improvements
4617 ** GDB provides the new class gdb.LazyString. This is useful in
4618 some pretty-printing cases. The new method gdb.Value.lazy_string
4619 provides a simple way to create objects of this type.
4621 ** The fields returned by gdb.Type.fields now have an
4622 `is_base_class' attribute.
4624 ** The new method gdb.Type.range returns the range of an array type.
4626 ** The new method gdb.parse_and_eval can be used to parse and
4627 evaluate an expression.
4629 * New remote packets
4632 Define a trace state variable.
4635 Get the current value of a trace state variable.
4638 Set desired tracing behavior upon disconnection.
4641 Set the trace buffer to be linear or circular.
4644 Get data about the tracepoints currently in use.
4648 Process record now works correctly with hardware watchpoints.
4650 Multiple bug fixes have been made to the mips-irix port, making it
4651 much more reliable. In particular:
4652 - Debugging threaded applications is now possible again. Previously,
4653 GDB would hang while starting the program, or while waiting for
4654 the program to stop at a breakpoint.
4655 - Attaching to a running process no longer hangs.
4656 - An error occurring while loading a core file has been fixed.
4657 - Changing the value of the PC register now works again. This fixes
4658 problems observed when using the "jump" command, or when calling
4659 a function from GDB, or even when assigning a new value to $pc.
4660 - With the "finish" and "return" commands, the return value for functions
4661 returning a small array is now correctly printed.
4662 - It is now possible to break on shared library code which gets executed
4663 during a shared library init phase (code executed while executing
4664 their .init section). Previously, the breakpoint would have no effect.
4665 - GDB is now able to backtrace through the signal handler for
4666 non-threaded programs.
4668 PIE (Position Independent Executable) programs debugging is now supported.
4669 This includes debugging execution of PIC (Position Independent Code) shared
4670 libraries although for that, it should be possible to run such libraries as an
4673 *** Changes in GDB 7.0
4675 * GDB now has an interface for JIT compilation. Applications that
4676 dynamically generate code can create symbol files in memory and register
4677 them with GDB. For users, the feature should work transparently, and
4678 for JIT developers, the interface is documented in the GDB manual in the
4679 "JIT Compilation Interface" chapter.
4681 * Tracepoints may now be conditional. The syntax is as for
4682 breakpoints; either an "if" clause appended to the "trace" command,
4683 or the "condition" command is available. GDB sends the condition to
4684 the target for evaluation using the same bytecode format as is used
4685 for tracepoint actions.
4687 * The disassemble command now supports: an optional /r modifier, print the
4688 raw instructions in hex as well as in symbolic form, and an optional /m
4689 modifier to print mixed source+assembly.
4691 * Process record and replay
4693 In a architecture environment that supports ``process record and
4694 replay'', ``process record and replay'' target can record a log of
4695 the process execution, and replay it with both forward and reverse
4698 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4699 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4700 set execution-direction {forward|reverse}, for targets that support
4703 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4704 feature is available with a native GDB running on kernel version
4707 * GDB now has support for multi-byte and wide character sets on the
4708 target. Strings whose character type is wchar_t, char16_t, or
4709 char32_t are now correctly printed. GDB supports wide- and unicode-
4710 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4711 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4712 `printf'. This feature requires iconv to work properly; if your
4713 system does not have a working iconv, GDB can use GNU libiconv. See
4714 the installation instructions for more information.
4716 * GDB now supports automatic retrieval of shared library files from
4717 remote targets. To use this feature, specify a system root that begins
4718 with the `remote:' prefix, either via the `set sysroot' command or via
4719 the `--with-sysroot' configure-time option.
4721 * "info sharedlibrary" now takes an optional regex of libraries to show,
4722 and it now reports if a shared library has no debugging information.
4724 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4725 now complete on file names.
4727 * When completing in expressions, gdb will attempt to limit
4728 completions to allowable structure or union fields, where appropriate.
4729 For instance, consider:
4731 # struct example { int f1; double f2; };
4732 # struct example variable;
4735 If the user types TAB at the end of this command line, the available
4736 completions will be "f1" and "f2".
4738 * Inlined functions are now supported. They show up in backtraces, and
4739 the "step", "next", and "finish" commands handle them automatically.
4741 * GDB now supports the token-splicing (##) and stringification (#)
4742 operators when expanding macros. It also supports variable-arity
4745 * GDB now supports inspecting extra signal information, exported by
4746 the new $_siginfo convenience variable. The feature is currently
4747 implemented on linux ARM, i386 and amd64.
4749 * GDB can now display the VFP floating point registers and NEON vector
4750 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4751 can provide these registers (requires Linux 2.6.30 or later). Remote
4752 and simulator targets may also provide them.
4754 * New remote packets
4757 Search memory for a sequence of bytes.
4760 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4761 operation over reliable transport links. Use of this packet is
4762 controlled by the `set remote noack-packet' command.
4765 Kill the process with the specified process ID. Use this in preference
4766 to `k' when multiprocess protocol extensions are supported.
4769 Obtains additional operating system information
4773 Read or write additional signal information.
4775 * Removed remote protocol undocumented extension
4777 An undocumented extension to the remote protocol's `S' stop reply
4778 packet that permitted the stub to pass a process id was removed.
4779 Remote servers should use the `T' stop reply packet instead.
4781 * GDB now supports multiple function calling conventions according to the
4782 DWARF-2 DW_AT_calling_convention function attribute.
4784 * The SH target utilizes the aforementioned change to distinguish between gcc
4785 and Renesas calling convention. It also adds the new CLI commands
4786 `set/show sh calling-convention'.
4788 * GDB can now read compressed debug sections, as produced by GNU gold
4789 with the --compress-debug-sections=zlib flag.
4791 * 64-bit core files are now supported on AIX.
4793 * Thread switching is now supported on Tru64.
4795 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4796 which will be allocated using malloc later in program execution.
4798 * The qXfer:libraries:read remote protocol packet now allows passing a
4799 list of section offsets.
4801 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4802 conditions handling signals delivered during attach or thread creation
4803 have also been fixed.
4805 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4806 From the user's standpoint, all unqualified instances of True and False
4807 are treated as the standard definitions, regardless of context.
4809 * GDB now parses C++ symbol and type names more flexibly. For
4812 template<typename T> class C { };
4815 GDB will now correctly handle all of:
4817 ptype C<char const *>
4818 ptype C<char const*>
4819 ptype C<const char *>
4820 ptype C<const char*>
4822 * New features in the GDB remote stub, gdbserver
4824 - The "--wrapper" command-line argument tells gdbserver to use a
4825 wrapper program to launch programs for debugging.
4827 - On PowerPC and S/390 targets, it is now possible to use a single
4828 gdbserver executable to debug both 32-bit and 64-bit programs.
4829 (This requires gdbserver itself to be built as a 64-bit executable.)
4831 - gdbserver uses the new noack protocol mode for TCP connections to
4832 reduce communications latency, if also supported and enabled in GDB.
4834 - Support for the sparc64-linux-gnu target is now included in
4837 - The amd64-linux build of gdbserver now supports debugging both
4838 32-bit and 64-bit programs.
4840 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4841 now support hardware watchpoints, and will use them automatically
4846 GDB now has support for scripting using Python. Whether this is
4847 available is determined at configure time.
4849 New GDB commands can now be written in Python.
4851 * Ada tasking support
4853 Ada tasks can now be inspected in GDB. The following commands have
4857 Print the list of Ada tasks.
4859 Print detailed information about task number N.
4861 Print the task number of the current task.
4863 Switch the context of debugging to task number N.
4865 * Support for user-defined prefixed commands. The "define" command can
4866 add new commands to existing prefixes, e.g. "target".
4868 * Multi-inferior, multi-process debugging.
4870 GDB now has generalized support for multi-inferior debugging. See
4871 "Debugging Multiple Inferiors" in the manual for more information.
4872 Although availability still depends on target support, the command
4873 set is more uniform now. The GNU/Linux specific multi-forks support
4874 has been migrated to this new framework. This implied some user
4875 visible changes; see "New commands" and also "Removed commands"
4878 * Target descriptions can now describe the target OS ABI. See the
4879 "Target Description Format" section in the user manual for more
4882 * Target descriptions can now describe "compatible" architectures
4883 to indicate that the target can execute applications for a different
4884 architecture in addition to those for the main target architecture.
4885 See the "Target Description Format" section in the user manual for
4888 * Multi-architecture debugging.
4890 GDB now includes general supports for debugging applications on
4891 hybrid systems that use more than one single processor architecture
4892 at the same time. Each such hybrid architecture still requires
4893 specific support to be added. The only hybrid architecture supported
4894 in this version of GDB is the Cell Broadband Engine.
4896 * GDB now supports integrated debugging of Cell/B.E. applications that
4897 use both the PPU and SPU architectures. To enable support for hybrid
4898 Cell/B.E. debugging, you need to configure GDB to support both the
4899 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4900 --enable-targets configure option.
4902 * Non-stop mode debugging.
4904 For some targets, GDB now supports an optional mode of operation in
4905 which you can examine stopped threads while other threads continue
4906 to execute freely. This is referred to as non-stop mode, with the
4907 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4908 section in the user manual for more information.
4910 To be able to support remote non-stop debugging, a remote stub needs
4911 to implement the non-stop mode remote protocol extensions, as
4912 described in the "Remote Non-Stop" section of the user manual. The
4913 GDB remote stub, gdbserver, has been adjusted to support these
4914 extensions on linux targets.
4916 * New commands (for set/show, see "New options" below)
4918 catch syscall [NAME(S) | NUMBER(S)]
4919 Catch system calls. Arguments, which should be names of system
4920 calls or their numbers, mean catch only those syscalls. Without
4921 arguments, every syscall will be caught. When the inferior issues
4922 any of the specified syscalls, GDB will stop and announce the system
4923 call, both when it is called and when its call returns. This
4924 feature is currently available with a native GDB running on the
4925 Linux Kernel, under the following architectures: x86, x86_64,
4926 PowerPC and PowerPC64.
4928 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4930 Search memory for a sequence of bytes.
4932 maint set python print-stack
4933 maint show python print-stack
4934 Show a stack trace when an error is encountered in a Python script.
4937 Invoke CODE by passing it to the Python interpreter.
4942 These allow macros to be defined, undefined, and listed
4946 Show operating system information about processes.
4949 List the inferiors currently under GDB's control.
4952 Switch focus to inferior number NUM.
4955 Detach from inferior number NUM.
4958 Kill inferior number NUM.
4962 set spu stop-on-load
4963 show spu stop-on-load
4964 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4966 set spu auto-flush-cache
4967 show spu auto-flush-cache
4968 Control whether to automatically flush the software-managed cache
4969 during Cell/B.E. debugging.
4971 set sh calling-convention
4972 show sh calling-convention
4973 Control the calling convention used when calling SH target functions.
4976 show debug timestamp
4977 Control display of timestamps with GDB debugging output.
4979 set disassemble-next-line
4980 show disassemble-next-line
4981 Control display of disassembled source lines or instructions when
4984 set remote noack-packet
4985 show remote noack-packet
4986 Set/show the use of remote protocol QStartNoAckMode packet. See above
4987 under "New remote packets."
4989 set remote query-attached-packet
4990 show remote query-attached-packet
4991 Control use of remote protocol `qAttached' (query-attached) packet.
4993 set remote read-siginfo-object
4994 show remote read-siginfo-object
4995 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4998 set remote write-siginfo-object
4999 show remote write-siginfo-object
5000 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5003 set remote reverse-continue
5004 show remote reverse-continue
5005 Control use of remote protocol 'bc' (reverse-continue) packet.
5007 set remote reverse-step
5008 show remote reverse-step
5009 Control use of remote protocol 'bs' (reverse-step) packet.
5011 set displaced-stepping
5012 show displaced-stepping
5013 Control displaced stepping mode. Displaced stepping is a way to
5014 single-step over breakpoints without removing them from the debuggee.
5015 Also known as "out-of-line single-stepping".
5018 show debug displaced
5019 Control display of debugging info for displaced stepping.
5021 maint set internal-error
5022 maint show internal-error
5023 Control what GDB does when an internal error is detected.
5025 maint set internal-warning
5026 maint show internal-warning
5027 Control what GDB does when an internal warning is detected.
5032 Use a wrapper program to launch programs for debugging.
5034 set multiple-symbols (all|ask|cancel)
5035 show multiple-symbols
5036 The value of this variable can be changed to adjust the debugger behavior
5037 when an expression or a breakpoint location contains an ambiguous symbol
5038 name (an overloaded function name, for instance).
5040 set breakpoint always-inserted
5041 show breakpoint always-inserted
5042 Keep breakpoints always inserted in the target, as opposed to inserting
5043 them when resuming the target, and removing them when the target stops.
5044 This option can improve debugger performance on slow remote targets.
5046 set arm fallback-mode (arm|thumb|auto)
5047 show arm fallback-mode
5048 set arm force-mode (arm|thumb|auto)
5050 These commands control how ARM GDB determines whether instructions
5051 are ARM or Thumb. The default for both settings is auto, which uses
5052 the current CPSR value for instructions without symbols; previous
5053 versions of GDB behaved as if "set arm fallback-mode arm".
5055 set disable-randomization
5056 show disable-randomization
5057 Standalone programs run with the virtual address space randomization enabled
5058 by default on some platforms. This option keeps the addresses stable across
5059 multiple debugging sessions.
5063 Control whether other threads are stopped or not when some thread hits
5068 Requests that asynchronous execution is enabled in the target, if available.
5069 In this case, it's possible to resume target in the background, and interact
5070 with GDB while the target is running. "show target-async" displays the
5071 current state of asynchronous execution of the target.
5073 set target-wide-charset
5074 show target-wide-charset
5075 The target-wide-charset is the name of the character set that GDB
5076 uses when printing characters whose type is wchar_t.
5078 set tcp auto-retry (on|off)
5080 set tcp connect-timeout
5081 show tcp connect-timeout
5082 These commands allow GDB to retry failed TCP connections to a remote stub
5083 with a specified timeout period; this is useful if the stub is launched
5084 in parallel with GDB but may not be ready to accept connections immediately.
5086 set libthread-db-search-path
5087 show libthread-db-search-path
5088 Control list of directories which GDB will search for appropriate
5091 set schedule-multiple (on|off)
5092 show schedule-multiple
5093 Allow GDB to resume all threads of all processes or only threads of
5094 the current process.
5098 Use more aggressive caching for accesses to the stack. This improves
5099 performance of remote debugging (particularly backtraces) without
5100 affecting correctness.
5102 set interactive-mode (on|off|auto)
5103 show interactive-mode
5104 Control whether GDB runs in interactive mode (on) or not (off).
5105 When in interactive mode, GDB waits for the user to answer all
5106 queries. Otherwise, GDB does not wait and assumes the default
5107 answer. When set to auto (the default), GDB determines which
5108 mode to use based on the stdin settings.
5113 For program forks, this is replaced by the new more generic `info
5114 inferiors' command. To list checkpoints, you can still use the
5115 `info checkpoints' command, which was an alias for the `info forks'
5119 Replaced by the new `inferior' command. To switch between
5120 checkpoints, you can still use the `restart' command, which was an
5121 alias for the `fork' command.
5124 This is removed, since some targets don't have a notion of
5125 processes. To switch between processes, you can still use the
5126 `inferior' command using GDB's own inferior number.
5129 For program forks, this is replaced by the new more generic `kill
5130 inferior' command. To delete a checkpoint, you can still use the
5131 `delete checkpoint' command, which was an alias for the `delete
5135 For program forks, this is replaced by the new more generic `detach
5136 inferior' command. To detach a checkpoint, you can still use the
5137 `detach checkpoint' command, which was an alias for the `detach
5140 * New native configurations
5142 x86/x86_64 Darwin i[34567]86-*-darwin*
5144 x86_64 MinGW x86_64-*-mingw*
5148 Lattice Mico32 lm32-*
5149 x86 DICOS i[34567]86-*-dicos*
5150 x86_64 DICOS x86_64-*-dicos*
5153 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5154 (mingw32ce) debugging.
5160 These commands were actually not implemented on any target.
5162 *** Changes in GDB 6.8
5164 * New native configurations
5166 NetBSD/hppa hppa*-*netbsd*
5167 Xtensa GNU/Linux xtensa*-*-linux*
5171 NetBSD/hppa hppa*-*-netbsd*
5172 Xtensa GNU/Linux xtensa*-*-linux*
5174 * Change in command line behavior -- corefiles vs. process ids.
5176 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5177 attaching to process NUMBER fails, GDB no longer attempts to open a
5178 core file named NUMBER. Attaching to a program using the -c option
5179 is no longer supported. Instead, use the '-p' or '--pid' options.
5181 * GDB can now be built as a native debugger for debugging Windows x86
5182 (mingw32) Portable Executable (PE) programs.
5184 * Pending breakpoints no longer change their number when their address
5187 * GDB now supports breakpoints with multiple locations,
5188 including breakpoints on C++ constructors, inside C++ templates,
5189 and in inlined functions.
5191 * GDB's ability to debug optimized code has been improved. GDB more
5192 accurately identifies function bodies and lexical blocks that occupy
5193 more than one contiguous range of addresses.
5195 * Target descriptions can now describe registers for PowerPC.
5197 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5198 registers on PowerPC targets.
5200 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5201 targets even when the libthread_db library is not available.
5203 * The GDB remote stub, gdbserver, now supports the new file transfer
5204 commands (remote put, remote get, and remote delete).
5206 * The GDB remote stub, gdbserver, now supports run and attach in
5207 extended-remote mode.
5209 * hppa*64*-*-hpux11* target broken
5210 The debugger is unable to start a program and fails with the following
5211 error: "Error trying to get information about dynamic linker".
5212 The gdb-6.7 release is also affected.
5214 * GDB now supports the --enable-targets= configure option to allow
5215 building a single GDB executable that supports multiple remote
5216 target architectures.
5218 * GDB now supports debugging C and C++ programs which use the
5219 Decimal Floating Point extension. In addition, the PowerPC target
5220 now has a set of pseudo-registers to inspect decimal float values
5221 stored in two consecutive float registers.
5223 * The -break-insert MI command can optionally create pending
5226 * Improved support for debugging Ada
5227 Many improvements to the Ada language support have been made. These
5229 - Better support for Ada2005 interface types
5230 - Improved handling of arrays and slices in general
5231 - Better support for Taft-amendment types
5232 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5234 - Improved command completion in Ada
5237 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5242 set print frame-arguments (all|scalars|none)
5243 show print frame-arguments
5244 The value of this variable can be changed to control which argument
5245 values should be printed by the debugger when displaying a frame.
5250 Transfer files to and from a remote target, and delete remote files.
5257 Transfer files to and from a remote target, and delete remote files.
5259 * New remote packets
5266 Open, close, read, write, and delete files on the remote system.
5269 Attach to an existing process on the remote system, in extended-remote
5273 Run a new process on the remote system, in extended-remote mode.
5275 *** Changes in GDB 6.7
5277 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5278 bfd, libiberty and opcodes, as revealed by static analysis donated by
5279 Coverity, Inc. (http://scan.coverity.com).
5281 * When looking up multiply-defined global symbols, GDB will now prefer the
5282 symbol definition in the current shared library if it was built using the
5283 -Bsymbolic linker option.
5285 * When the Text User Interface (TUI) is not configured, GDB will now
5286 recognize the -tui command-line option and print a message that the TUI
5289 * The GDB remote stub, gdbserver, now has lower overhead for high
5290 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5292 * GDB for MIPS targets now autodetects whether a remote target provides
5293 32-bit or 64-bit register values.
5295 * Support for C++ member pointers has been improved.
5297 * GDB now understands XML target descriptions, which specify the
5298 target's overall architecture. GDB can read a description from
5299 a local file or over the remote serial protocol.
5301 * Vectors of single-byte data use a new integer type which is not
5302 automatically displayed as character or string data.
5304 * The /s format now works with the print command. It displays
5305 arrays of single-byte integers and pointers to single-byte integers
5308 * Target descriptions can now describe target-specific registers,
5309 for architectures which have implemented the support (currently
5310 only ARM, M68K, and MIPS).
5312 * GDB and the GDB remote stub, gdbserver, now support the XScale
5315 * The GDB remote stub, gdbserver, has been updated to support
5316 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5317 has been rewritten to use the standard GDB remote protocol.
5319 * GDB can now step into C++ functions which are called through thunks.
5321 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5323 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5324 layout. It also supports a TextSeg= and DataSeg= response when only
5325 segment base addresses (rather than offsets) are available.
5327 * The /i format now outputs any trailing branch delay slot instructions
5328 immediately following the last instruction within the count specified.
5330 * The GDB remote protocol "T" stop reply packet now supports a
5331 "library" response. Combined with the new "qXfer:libraries:read"
5332 packet, this response allows GDB to debug shared libraries on targets
5333 where the operating system manages the list of loaded libraries (e.g.
5334 Windows and SymbianOS).
5336 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5337 (DLLs) on Windows and Windows CE targets.
5339 * GDB now supports a faster verification that a .debug file matches its binary
5340 according to its build-id signature, if the signature is present.
5346 Enable or disable hardware flow control (RTS/CTS) on the serial port
5347 when debugging using remote targets.
5349 set mem inaccessible-by-default
5350 show mem inaccessible-by-default
5351 If the target supplies a memory map, for instance via the remote
5352 protocol's "qXfer:memory-map:read" packet, setting this variable
5353 prevents GDB from accessing memory outside the memory map. This
5354 is useful for targets with memory mapped registers or which react
5355 badly to accesses of unmapped address space.
5357 set breakpoint auto-hw
5358 show breakpoint auto-hw
5359 If the target supplies a memory map, for instance via the remote
5360 protocol's "qXfer:memory-map:read" packet, setting this variable
5361 lets GDB use hardware breakpoints automatically for memory regions
5362 where it can not use software breakpoints. This covers both the
5363 "break" command and internal breakpoints used for other commands
5364 including "next" and "finish".
5367 catch exception unhandled
5368 Stop the program execution when Ada exceptions are raised.
5371 Stop the program execution when an Ada assertion failed.
5375 Set an alternate system root for target files. This is a more
5376 general version of "set solib-absolute-prefix", which is now
5377 an alias to "set sysroot".
5380 Provide extended SPU facility status information. This set of
5381 commands is available only when debugging the Cell/B.E. SPU
5384 * New native configurations
5386 OpenBSD/sh sh*-*openbsd*
5389 unset tdesc filename
5391 Use the specified local file as an XML target description, and do
5392 not query the target for its built-in description.
5396 OpenBSD/sh sh*-*-openbsd*
5397 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5398 Toshiba Media Processor mep-elf
5400 * New remote packets
5403 Ignore the specified signals; pass them directly to the debugged program
5404 without stopping other threads or reporting them to GDB.
5406 qXfer:features:read:
5407 Read an XML target description from the target, which describes its
5412 Read or write contents of an spufs file on the target system. These
5413 packets are available only on the Cell/B.E. SPU architecture.
5415 qXfer:libraries:read:
5416 Report the loaded shared libraries. Combined with new "T" packet
5417 response, this packet allows GDB to debug shared libraries on
5418 targets where the operating system manages the list of loaded
5419 libraries (e.g. Windows and SymbianOS).
5423 Support for these obsolete configurations has been removed.
5431 i[34567]86-*-lynxos*
5432 i[34567]86-*-netware*
5433 i[34567]86-*-sco3.2v5*
5434 i[34567]86-*-sco3.2v4*
5436 i[34567]86-*-sysv4.2*
5439 i[34567]86-*-unixware2*
5440 i[34567]86-*-unixware*
5449 * Other removed features
5456 Various m68k-only ROM monitors.
5463 Various Renesas ROM monitors and debugging interfaces for SH and
5468 Support for a Macraigor serial interface to on-chip debugging.
5469 GDB does not directly support the newer parallel or USB
5474 A debug information format. The predecessor to DWARF 2 and
5475 DWARF 3, which are still supported.
5477 Support for the HP aCC compiler on HP-UX/PA-RISC
5479 SOM-encapsulated symbolic debugging information, automatic
5480 invocation of pxdb, and the aCC custom C++ ABI. This does not
5481 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5482 with aCC can still be debugged on an assembly level.
5484 MIPS ".pdr" sections
5486 A MIPS-specific format used to describe stack frame layout
5487 in debugging information.
5491 GDB could work with an older version of Guile to debug
5492 the interpreter and Scheme programs running in it.
5494 set mips stack-arg-size
5495 set mips saved-gpreg-size
5497 Use "set mips abi" to control parameter passing for MIPS.
5499 *** Changes in GDB 6.6
5504 Cell Broadband Engine SPU spu-elf
5506 * GDB can now be configured as a cross-debugger targeting native Windows
5507 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5508 running on a Windows system over TCP/IP to debug Windows programs.
5510 * The GDB remote stub, gdbserver, has been updated to support Windows and
5511 Cygwin debugging. Both single-threaded and multi-threaded programs are
5514 * The "set trust-readonly-sections" command works again. This command was
5515 broken in GDB 6.3, 6.4, and 6.5.
5517 * The "load" command now supports writing to flash memory, if the remote
5518 stub provides the required support.
5520 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5521 longer requires symbolic debug information (e.g. DWARF-2).
5526 unset substitute-path
5527 show substitute-path
5528 Manage a list of substitution rules that GDB uses to rewrite the name
5529 of the directories where the sources are located. This can be useful
5530 for instance when the sources were moved to a different location
5531 between compilation and debugging.
5535 Print each CLI command as it is executed. Each command is prefixed with
5536 a number of `+' symbols representing the nesting depth.
5537 The source command now has a `-v' option to enable the same feature.
5541 The ARM Demon monitor support (RDP protocol, "target rdp").
5543 Kernel Object Display, an embedded debugging feature which only worked with
5544 an obsolete version of Cisco IOS.
5546 The 'set download-write-size' and 'show download-write-size' commands.
5548 * New remote packets
5551 Tell a stub about GDB client features, and request remote target features.
5552 The first feature implemented is PacketSize, which allows the target to
5553 specify the size of packets it can handle - to minimize the number of
5554 packets required and improve performance when connected to a remote
5558 Fetch an OS auxilliary vector from the remote stub. This packet is a
5559 more efficient replacement for qPart:auxv:read.
5561 qXfer:memory-map:read:
5562 Fetch a memory map from the remote stub, including information about
5563 RAM, ROM, and flash memory devices.
5568 Erase and program a flash memory device.
5570 * Removed remote packets
5573 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5574 used it, and only gdbserver implemented it.
5576 *** Changes in GDB 6.5
5580 Renesas M32C/M16C m32c-elf
5582 Morpho Technologies ms1 ms1-elf
5586 init-if-undefined Initialize a convenience variable, but
5587 only if it doesn't already have a value.
5589 The following commands are presently only implemented for native GNU/Linux:
5591 checkpoint Save a snapshot of the program state.
5593 restart <n> Return the program state to a
5594 previously saved state.
5596 info checkpoints List currently saved checkpoints.
5598 delete-checkpoint <n> Delete a previously saved checkpoint.
5600 set|show detach-on-fork Tell gdb whether to detach from a newly
5601 forked process, or to keep debugging it.
5603 info forks List forks of the user program that
5604 are available to be debugged.
5606 fork <n> Switch to debugging one of several
5607 forks of the user program that are
5608 available to be debugged.
5610 delete-fork <n> Delete a fork from the list of forks
5611 that are available to be debugged (and
5612 kill the forked process).
5614 detach-fork <n> Delete a fork from the list of forks
5615 that are available to be debugged (and
5616 allow the process to continue).
5620 Morpho Technologies ms2 ms1-elf
5622 * Improved Windows host support
5624 GDB now builds as a cross debugger hosted on i686-mingw32, including
5625 native console support, and remote communications using either
5626 network sockets or serial ports.
5628 * Improved Modula-2 language support
5630 GDB can now print most types in the Modula-2 syntax. This includes:
5631 basic types, set types, record types, enumerated types, range types,
5632 pointer types and ARRAY types. Procedure var parameters are correctly
5633 printed and hexadecimal addresses and character constants are also
5634 written in the Modula-2 syntax. Best results can be obtained by using
5635 GNU Modula-2 together with the -gdwarf-2 command line option.
5639 The ARM rdi-share module.
5641 The Netware NLM debug server.
5643 *** Changes in GDB 6.4
5645 * New native configurations
5647 OpenBSD/arm arm*-*-openbsd*
5648 OpenBSD/mips64 mips64-*-openbsd*
5652 Morpho Technologies ms1 ms1-elf
5654 * New command line options
5656 --batch-silent As for --batch, but totally silent.
5657 --return-child-result The debugger will exist with the same value
5658 the child (debugged) program exited with.
5659 --eval-command COMMAND, -ex COMMAND
5660 Execute a single GDB CLI command. This may be
5661 specified multiple times and in conjunction
5662 with the --command (-x) option.
5664 * Deprecated commands removed
5666 The following commands, that were deprecated in 2000, have been
5670 set|show arm disassembly-flavor set|show arm disassembler
5671 othernames set arm disassembler
5672 set|show remotedebug set|show debug remote
5673 set|show archdebug set|show debug arch
5674 set|show eventdebug set|show debug event
5677 * New BSD user-level threads support
5679 It is now possible to debug programs using the user-level threads
5680 library on OpenBSD and FreeBSD. Currently supported (target)
5683 FreeBSD/amd64 x86_64-*-freebsd*
5684 FreeBSD/i386 i386-*-freebsd*
5685 OpenBSD/i386 i386-*-openbsd*
5687 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5688 are not yet supported.
5690 * New support for Matsushita MN10300 w/sim added
5691 (Work in progress). mn10300-elf.
5693 * REMOVED configurations and files
5695 VxWorks and the XDR protocol *-*-vxworks
5696 Motorola MCORE mcore-*-*
5697 National Semiconductor NS32000 ns32k-*-*
5699 * New "set print array-indexes" command
5701 After turning this setting "on", GDB prints the index of each element
5702 when displaying arrays. The default is "off" to preserve the previous
5705 * VAX floating point support
5707 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5709 * User-defined command support
5711 In addition to using $arg0..$arg9 for argument passing, it is now possible
5712 to use $argc to determine now many arguments have been passed. See the
5713 section on user-defined commands in the user manual for more information.
5715 *** Changes in GDB 6.3:
5717 * New command line option
5719 GDB now accepts -l followed by a number to set the timeout for remote
5722 * GDB works with GCC -feliminate-dwarf2-dups
5724 GDB now supports a more compact representation of DWARF-2 debug
5725 information using DW_FORM_ref_addr references. These are produced
5726 by GCC with the option -feliminate-dwarf2-dups and also by some
5727 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5728 to use -feliminate-dwarf2-dups.
5730 * Internationalization
5732 When supported by the host system, GDB will be built with
5733 internationalization (libintl). The task of marking up the sources is
5734 continued, we're looking forward to our first translation.
5738 Initial support for debugging programs compiled with the GNAT
5739 implementation of the Ada programming language has been integrated
5740 into GDB. In this release, support is limited to expression evaluation.
5742 * New native configurations
5744 GNU/Linux/m32r m32r-*-linux-gnu
5748 GDB's remote protocol now includes support for the 'p' packet. This
5749 packet is used to fetch individual registers from a remote inferior.
5751 * END-OF-LIFE registers[] compatibility module
5753 GDB's internal register infrastructure has been completely rewritten.
5754 The new infrastructure making possible the implementation of key new
5755 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5758 GDB 6.3 will be the last release to include the registers[]
5759 compatibility module that allowed out-of-date configurations to
5760 continue to work. This change directly impacts the following
5770 powerpc bdm protocol
5772 Unless there is activity to revive these configurations, they will be
5773 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5775 * OBSOLETE configurations and files
5777 Configurations that have been declared obsolete in this release have
5778 been commented out. Unless there is activity to revive these
5779 configurations, the next release of GDB will have their sources
5780 permanently REMOVED.
5789 *** Changes in GDB 6.2.1:
5791 * MIPS `break main; run' gave an heuristic-fence-post warning
5793 When attempting to run even a simple program, a warning about
5794 heuristic-fence-post being hit would be reported. This problem has
5797 * MIPS IRIX 'long double' crashed GDB
5799 When examining a long double variable, GDB would get a segmentation
5800 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5801 IRIX long double values).
5805 A bug in the VAX stack code was causing problems with the "next"
5806 command. This problem has been fixed.
5808 *** Changes in GDB 6.2:
5810 * Fix for ``many threads''
5812 On GNU/Linux systems that use the NPTL threads library, a program
5813 rapidly creating and deleting threads would confuse GDB leading to the
5816 ptrace: No such process.
5817 thread_db_get_info: cannot get thread info: generic error
5819 This problem has been fixed.
5821 * "-async" and "-noasync" options removed.
5823 Support for the broken "-noasync" option has been removed (it caused
5826 * New ``start'' command.
5828 This command runs the program until the beginning of the main procedure.
5830 * New BSD Kernel Data Access Library (libkvm) interface
5832 Using ``target kvm'' it is now possible to debug kernel core dumps and
5833 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5834 platforms. Currently supported (native-only) configurations are:
5836 FreeBSD/amd64 x86_64-*-freebsd*
5837 FreeBSD/i386 i?86-*-freebsd*
5838 NetBSD/i386 i?86-*-netbsd*
5839 NetBSD/m68k m68*-*-netbsd*
5840 NetBSD/sparc sparc-*-netbsd*
5841 OpenBSD/amd64 x86_64-*-openbsd*
5842 OpenBSD/i386 i?86-*-openbsd*
5843 OpenBSD/m68k m68*-openbsd*
5844 OpenBSD/sparc sparc-*-openbsd*
5846 * Signal trampoline code overhauled
5848 Many generic problems with GDB's signal handling code have been fixed.
5849 These include: backtraces through non-contiguous stacks; recognition
5850 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5851 call; backtrace through a signal trampoline; step into and out of
5852 signal handlers; and single-stepping in the signal trampoline.
5854 Please note that kernel bugs are a limiting factor here. These
5855 features have been shown to work on an s390 GNU/Linux system that
5856 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5858 * Cygwin support for DWARF 2 added.
5860 * New native configurations
5862 GNU/Linux/hppa hppa*-*-linux*
5863 OpenBSD/hppa hppa*-*-openbsd*
5864 OpenBSD/m68k m68*-*-openbsd*
5865 OpenBSD/m88k m88*-*-openbsd*
5866 OpenBSD/powerpc powerpc-*-openbsd*
5867 NetBSD/vax vax-*-netbsd*
5868 OpenBSD/vax vax-*-openbsd*
5870 * END-OF-LIFE frame compatibility module
5872 GDB's internal frame infrastructure has been completely rewritten.
5873 The new infrastructure making it possible to support key new features
5874 including DWARF 2 Call Frame Information. To aid in the task of
5875 migrating old configurations to this new infrastructure, a
5876 compatibility module, that allowed old configurations to continue to
5877 work, was also included.
5879 GDB 6.2 will be the last release to include this frame compatibility
5880 module. This change directly impacts the following configurations:
5890 Unless there is activity to revive these configurations, they will be
5891 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5893 * REMOVED configurations and files
5895 Sun 3, running SunOS 3 m68*-*-sunos3*
5896 Sun 3, running SunOS 4 m68*-*-sunos4*
5897 Sun 2, running SunOS 3 m68000-*-sunos3*
5898 Sun 2, running SunOS 4 m68000-*-sunos4*
5899 Motorola 680x0 running LynxOS m68*-*-lynxos*
5900 AT&T 3b1/Unix pc m68*-att-*
5901 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5902 decstation mips-dec-* mips-little-*
5903 riscos mips-*-riscos* mips-*-sysv*
5904 sonymips mips-sony-*
5905 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5907 *** Changes in GDB 6.1.1:
5909 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5911 The TUI (Text-mode User Interface) is now built as part of a default
5912 GDB configuration. It is enabled by either selecting the TUI with the
5913 command line option "-i=tui" or by running the separate "gdbtui"
5914 program. For more information on the TUI, see the manual "Debugging
5917 * Pending breakpoint support (also included in GDB 6.1)
5919 Support has been added to allow you to specify breakpoints in shared
5920 libraries that have not yet been loaded. If a breakpoint location
5921 cannot be found, and the "breakpoint pending" option is set to auto,
5922 GDB queries you if you wish to make the breakpoint pending on a future
5923 shared-library load. If and when GDB resolves the breakpoint symbol,
5924 the pending breakpoint is removed as one or more regular breakpoints
5927 Pending breakpoints are very useful for GCJ Java debugging.
5929 * Fixed ISO-C build problems
5931 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5932 non ISO-C code that stopped them being built using a more strict ISO-C
5933 compiler (e.g., IBM's C compiler).
5935 * Fixed build problem on IRIX 5
5937 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5938 wasn't able to compile compile on an IRIX 5 system.
5940 * Added execute permission to gdb/gdbserver/configure
5942 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5943 permission. This bug would cause configure to fail on a number of
5944 systems (Solaris, IRIX). Ref: server/519.
5946 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5948 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5949 has been updated to use constant array sizes.
5951 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5953 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5954 its generated DWARF Call Frame Info. This encoding was causing GDB to
5955 panic, that panic has been fixed. Ref: gdb/1628.
5957 * Fixed a problem when examining parameters in shared library code.
5959 When examining parameters in optimized shared library code generated
5960 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5961 not available''. GDB now correctly displays the variable's value.
5963 *** Changes in GDB 6.1:
5965 * Removed --with-mmalloc
5967 Support for the mmalloc memory manager has been removed, as it
5968 conflicted with the internal gdb byte cache.
5970 * Changes in AMD64 configurations
5972 The AMD64 target now includes the %cs and %ss registers. As a result
5973 the AMD64 remote protocol has changed; this affects the floating-point
5974 and SSE registers. If you rely on those registers for your debugging,
5975 you should upgrade gdbserver on the remote side.
5977 * Revised SPARC target
5979 The SPARC target has been completely revised, incorporating the
5980 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5981 support for LynxOS and SunOS 4 has been dropped. Calling functions
5982 from within GDB on operating systems with a non-executable stack
5983 (Solaris, OpenBSD) now works.
5987 GDB has a new C++ demangler which does a better job on the mangled
5988 names generated by current versions of g++. It also runs faster, so
5989 with this and other changes gdb should now start faster on large C++
5992 * DWARF 2 Location Expressions
5994 GDB support for location expressions has been extended to support function
5995 arguments and frame bases. Older versions of GDB could crash when they
5998 * C++ nested types and namespaces
6000 GDB's support for nested types and namespaces in C++ has been
6001 improved, especially if you use the DWARF 2 debugging format. (This
6002 is the default for recent versions of GCC on most platforms.)
6003 Specifically, if you have a class "Inner" defined within a class or
6004 namespace "Outer", then GDB realizes that the class's name is
6005 "Outer::Inner", not simply "Inner". This should greatly reduce the
6006 frequency of complaints about not finding RTTI symbols. In addition,
6007 if you are stopped at inside of a function defined within a namespace,
6008 GDB modifies its name lookup accordingly.
6010 * New native configurations
6012 NetBSD/amd64 x86_64-*-netbsd*
6013 OpenBSD/amd64 x86_64-*-openbsd*
6014 OpenBSD/alpha alpha*-*-openbsd*
6015 OpenBSD/sparc sparc-*-openbsd*
6016 OpenBSD/sparc64 sparc64-*-openbsd*
6018 * New debugging protocols
6020 M32R with SDI protocol m32r-*-elf*
6022 * "set prompt-escape-char" command deleted.
6024 The command "set prompt-escape-char" has been deleted. This command,
6025 and its very obscure effect on GDB's prompt, was never documented,
6026 tested, nor mentioned in the NEWS file.
6028 * OBSOLETE configurations and files
6030 Configurations that have been declared obsolete in this release have
6031 been commented out. Unless there is activity to revive these
6032 configurations, the next release of GDB will have their sources
6033 permanently REMOVED.
6035 Sun 3, running SunOS 3 m68*-*-sunos3*
6036 Sun 3, running SunOS 4 m68*-*-sunos4*
6037 Sun 2, running SunOS 3 m68000-*-sunos3*
6038 Sun 2, running SunOS 4 m68000-*-sunos4*
6039 Motorola 680x0 running LynxOS m68*-*-lynxos*
6040 AT&T 3b1/Unix pc m68*-att-*
6041 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6042 decstation mips-dec-* mips-little-*
6043 riscos mips-*-riscos* mips-*-sysv*
6044 sonymips mips-sony-*
6045 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6047 * REMOVED configurations and files
6049 SGI Irix-4.x mips-sgi-irix4 or iris4
6050 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6051 Z8000 simulator z8k-zilog-none or z8ksim
6052 Matsushita MN10200 w/simulator mn10200-*-*
6053 H8/500 simulator h8500-hitachi-hms or h8500hms
6054 HP/PA running BSD hppa*-*-bsd*
6055 HP/PA running OSF/1 hppa*-*-osf*
6056 HP/PA Pro target hppa*-*-pro*
6057 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6058 386BSD i[3456]86-*-bsd*
6059 Sequent family i[3456]86-sequent-sysv4*
6060 i[3456]86-sequent-sysv*
6061 i[3456]86-sequent-bsd*
6062 SPARC running LynxOS sparc-*-lynxos*
6063 SPARC running SunOS 4 sparc-*-sunos4*
6064 Tsqware Sparclet sparclet-*-*
6065 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6067 *** Changes in GDB 6.0:
6071 Support for debugging the Objective-C programming language has been
6072 integrated into GDB.
6074 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6076 DWARF 2's Call Frame Information makes available compiler generated
6077 information that more exactly describes the program's run-time stack.
6078 By using this information, GDB is able to provide more robust stack
6081 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6082 have been updated to use a new backtrace mechanism which includes
6083 DWARF 2 CFI support.
6087 GDB's remote protocol has been extended to include support for hosted
6088 file I/O (where the remote target uses GDB's file system). See GDB's
6089 remote protocol documentation for details.
6091 * All targets using the new architecture framework.
6093 All of GDB's targets have been updated to use the new internal
6094 architecture framework. The way is now open for future GDB releases
6095 to include cross-architecture native debugging support (i386 on amd64,
6098 * GNU/Linux's Thread Local Storage (TLS)
6100 GDB now includes support for for the GNU/Linux implementation of
6101 per-thread variables.
6103 * GNU/Linux's Native POSIX Thread Library (NPTL)
6105 GDB's thread code has been updated to work with either the new
6106 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6108 * Separate debug info.
6110 GDB, in conjunction with BINUTILS, now supports a mechanism for
6111 automatically loading debug information from a separate file. Instead
6112 of shipping full debug and non-debug versions of system libraries,
6113 system integrators can now instead ship just the stripped libraries
6114 and optional debug files.
6116 * DWARF 2 Location Expressions
6118 DWARF 2 Location Expressions allow the compiler to more completely
6119 describe the location of variables (even in optimized code) to the
6122 GDB now includes preliminary support for location expressions (support
6123 for DW_OP_piece is still missing).
6127 A number of long standing bugs that caused GDB to die while starting a
6128 Java application have been fixed. GDB's Java support is now
6129 considered "useable".
6131 * GNU/Linux support for fork, vfork, and exec.
6133 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6134 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6137 * GDB supports logging output to a file
6139 There are two new commands, "set logging" and "show logging", which can be
6140 used to capture GDB's output to a file.
6142 * The meaning of "detach" has changed for gdbserver
6144 The "detach" command will now resume the application, as documented. To
6145 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6148 * d10v, m68hc11 `regs' command deprecated
6150 The `info registers' command has been updated so that it displays the
6151 registers using a format identical to the old `regs' command.
6155 A new command, "maint set profile on/off", has been added. This command can
6156 be used to enable or disable profiling while running GDB, to profile a
6157 session or a set of commands. In addition there is a new configure switch,
6158 "--enable-profiling", which will cause GDB to be compiled with profiling
6159 data, for more informative profiling results.
6161 * Default MI syntax changed to "mi2".
6163 The default MI (machine interface) syntax, enabled by the command line
6164 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6165 "mi1", can be enabled by specifying the option "-i=mi1".
6167 Support for the original "mi0" syntax (included in GDB 5.0) has been
6170 Fix for gdb/192: removed extraneous space when displaying frame level.
6171 Fix for gdb/672: update changelist is now output in mi list format.
6172 Fix for gdb/702: a -var-assign that updates the value now shows up
6173 in a subsequent -var-update.
6175 * New native configurations.
6177 FreeBSD/amd64 x86_64-*-freebsd*
6179 * Multi-arched targets.
6181 HP/PA HPUX11 hppa*-*-hpux*
6182 Renesas M32R/D w/simulator m32r-*-elf*
6184 * OBSOLETE configurations and files
6186 Configurations that have been declared obsolete in this release have
6187 been commented out. Unless there is activity to revive these
6188 configurations, the next release of GDB will have their sources
6189 permanently REMOVED.
6191 Z8000 simulator z8k-zilog-none or z8ksim
6192 Matsushita MN10200 w/simulator mn10200-*-*
6193 H8/500 simulator h8500-hitachi-hms or h8500hms
6194 HP/PA running BSD hppa*-*-bsd*
6195 HP/PA running OSF/1 hppa*-*-osf*
6196 HP/PA Pro target hppa*-*-pro*
6197 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6198 Sequent family i[3456]86-sequent-sysv4*
6199 i[3456]86-sequent-sysv*
6200 i[3456]86-sequent-bsd*
6201 Tsqware Sparclet sparclet-*-*
6202 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6204 * REMOVED configurations and files
6207 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6208 IBM AIX PS/2 i[3456]86-*-aix
6209 i386 running Mach 3.0 i[3456]86-*-mach3*
6210 i386 running Mach i[3456]86-*-mach*
6211 i386 running OSF/1 i[3456]86-*osf1mk*
6212 HP/Apollo 68k Family m68*-apollo*-sysv*,
6214 m68*-hp-bsd*, m68*-hp-hpux*
6215 Argonaut Risc Chip (ARC) arc-*-*
6216 Mitsubishi D30V d30v-*-*
6217 Fujitsu FR30 fr30-*-elf*
6218 OS/9000 i[34]86-*-os9k
6219 I960 with MON960 i960-*-coff
6221 * MIPS $fp behavior changed
6223 The convenience variable $fp, for the MIPS, now consistently returns
6224 the address of the current frame's base. Previously, depending on the
6225 context, $fp could refer to either $sp or the current frame's base
6226 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6227 The GNU Source-Level Debugger''.
6229 *** Changes in GDB 5.3:
6231 * GNU/Linux shared library multi-threaded performance improved.
6233 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6234 `/proc', in preference to `ptrace' for memory reads. This may result
6235 in an improvement in the start-up time of multi-threaded, shared
6236 library applications when run under GDB. One GDB user writes: ``loads
6237 shared libs like mad''.
6239 * ``gdbserver'' now supports multi-threaded applications on some targets
6241 Support for debugging multi-threaded applications which use
6242 the GNU/Linux LinuxThreads package has been added for
6243 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6244 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6246 * GDB now supports C/C++ preprocessor macros.
6248 GDB now expands preprocessor macro invocations in C/C++ expressions,
6249 and provides various commands for showing macro definitions and how
6252 The new command `macro expand EXPRESSION' expands any macro
6253 invocations in expression, and shows the result.
6255 The new command `show macro MACRO-NAME' shows the definition of the
6256 macro named MACRO-NAME, and where it was defined.
6258 Most compilers don't include information about macros in the debugging
6259 information by default. In GCC 3.1, for example, you need to compile
6260 your program with the options `-gdwarf-2 -g3'. If the macro
6261 information is present in the executable, GDB will read it.
6263 * Multi-arched targets.
6265 DEC Alpha (partial) alpha*-*-*
6266 DEC VAX (partial) vax-*-*
6268 National Semiconductor NS32000 (partial) ns32k-*-*
6269 Motorola 68000 (partial) m68k-*-*
6270 Motorola MCORE mcore-*-*
6274 Fujitsu FRV architecture added by Red Hat frv*-*-*
6277 * New native configurations
6279 Alpha NetBSD alpha*-*-netbsd*
6280 SH NetBSD sh*-*-netbsdelf*
6281 MIPS NetBSD mips*-*-netbsd*
6282 UltraSPARC NetBSD sparc64-*-netbsd*
6284 * OBSOLETE configurations and files
6286 Configurations that have been declared obsolete in this release have
6287 been commented out. Unless there is activity to revive these
6288 configurations, the next release of GDB will have their sources
6289 permanently REMOVED.
6291 Mitsubishi D30V d30v-*-*
6292 OS/9000 i[34]86-*-os9k
6293 IBM AIX PS/2 i[3456]86-*-aix
6294 Fujitsu FR30 fr30-*-elf*
6295 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6296 Argonaut Risc Chip (ARC) arc-*-*
6297 i386 running Mach 3.0 i[3456]86-*-mach3*
6298 i386 running Mach i[3456]86-*-mach*
6299 i386 running OSF/1 i[3456]86-*osf1mk*
6300 HP/Apollo 68k Family m68*-apollo*-sysv*,
6302 m68*-hp-bsd*, m68*-hp-hpux*
6303 I960 with MON960 i960-*-coff
6305 * OBSOLETE languages
6307 CHILL, a Pascal like language used by telecommunications companies.
6309 * REMOVED configurations and files
6311 AMD 29k family via UDI a29k-amd-udi, udi29k
6312 A29K VxWorks a29k-*-vxworks
6313 AMD 29000 embedded, using EBMON a29k-none-none
6314 AMD 29000 embedded with COFF a29k-none-coff
6315 AMD 29000 embedded with a.out a29k-none-aout
6317 testsuite/gdb.hp/gdb.threads-hp/ directory
6319 * New command "set max-user-call-depth <nnn>"
6321 This command allows the user to limit the call depth of user-defined
6322 commands. The default is 1024.
6324 * Changes in FreeBSD/i386 native debugging.
6326 Support for the "generate-core-file" has been added.
6328 * New commands "dump", "append", and "restore".
6330 These commands allow data to be copied from target memory
6331 to a bfd-format or binary file (dump and append), and back
6332 from a file into memory (restore).
6334 * Improved "next/step" support on multi-processor Alpha Tru64.
6336 The previous single-step mechanism could cause unpredictable problems,
6337 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6338 of a software single-step mechanism prevents this.
6340 *** Changes in GDB 5.2.1:
6348 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6349 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6350 Fix, by Joel Brobecker imported from mainline.
6352 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6353 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6354 Fix, by Fred Fish, imported from mainline.
6356 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6357 Surprisingly enough, it works now.
6358 By Michal Ludvig, imported from mainline.
6360 i386 hardware watchpoint support:
6361 avoid misses on second run for some targets.
6362 By Pierre Muller, imported from mainline.
6364 *** Changes in GDB 5.2:
6366 * New command "set trust-readonly-sections on[off]".
6368 This command is a hint that tells gdb that read-only sections
6369 really are read-only (ie. that their contents will not change).
6370 In this mode, gdb will go to the object file rather than the
6371 target to read memory from read-only sections (such as ".text").
6372 This can be a significant performance improvement on some
6373 (notably embedded) targets.
6375 * New command "generate-core-file" (or "gcore").
6377 This new gdb command allows the user to drop a core file of the child
6378 process state at any time. So far it's been implemented only for
6379 GNU/Linux and Solaris, but should be relatively easily ported to other
6380 hosts. Argument is core file name (defaults to core.<pid>).
6382 * New command line option
6384 GDB now accepts --pid or -p followed by a process id.
6386 * Change in command line behavior -- corefiles vs. process ids.
6388 There is a subtle behavior in the way in which GDB handles
6389 command line arguments. The first non-flag argument is always
6390 a program to debug, but the second non-flag argument may either
6391 be a corefile or a process id. Previously, GDB would attempt to
6392 open the second argument as a corefile, and if that failed, would
6393 issue a superfluous error message and then attempt to attach it as
6394 a process. Now, if the second argument begins with a non-digit,
6395 it will be treated as a corefile. If it begins with a digit,
6396 GDB will attempt to attach it as a process, and if no such process
6397 is found, will then attempt to open it as a corefile.
6399 * Changes in ARM configurations.
6401 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6402 configuration is fully multi-arch.
6404 * New native configurations
6406 ARM NetBSD arm*-*-netbsd*
6407 x86 OpenBSD i[3456]86-*-openbsd*
6408 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6409 Sparc64 running FreeBSD sparc64-*-freebsd*
6413 Sanyo XStormy16 xstormy16-elf
6415 * OBSOLETE configurations and files
6417 Configurations that have been declared obsolete in this release have
6418 been commented out. Unless there is activity to revive these
6419 configurations, the next release of GDB will have their sources
6420 permanently REMOVED.
6422 AMD 29k family via UDI a29k-amd-udi, udi29k
6423 A29K VxWorks a29k-*-vxworks
6424 AMD 29000 embedded, using EBMON a29k-none-none
6425 AMD 29000 embedded with COFF a29k-none-coff
6426 AMD 29000 embedded with a.out a29k-none-aout
6428 testsuite/gdb.hp/gdb.threads-hp/ directory
6430 * REMOVED configurations and files
6432 TI TMS320C80 tic80-*-*
6434 PowerPC Solaris powerpcle-*-solaris*
6435 PowerPC Windows NT powerpcle-*-cygwin32
6436 PowerPC Netware powerpc-*-netware*
6437 Harris/CXUX m88k m88*-harris-cxux*
6438 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6439 ns32k-utek-sysv* ns32k-utek-*
6440 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6441 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6442 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6443 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6444 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6446 * Changes to command line processing
6448 The new `--args' feature can be used to specify command-line arguments
6449 for the inferior from gdb's command line.
6451 * Changes to key bindings
6453 There is a new `operate-and-get-next' function bound to `C-o'.
6455 *** Changes in GDB 5.1.1
6457 Fix compile problem on DJGPP.
6459 Fix a problem with floating-point registers on the i386 being
6462 Fix to stop GDB crashing on .debug_str debug info.
6464 Numerous documentation fixes.
6466 Numerous testsuite fixes.
6468 *** Changes in GDB 5.1:
6470 * New native configurations
6472 Alpha FreeBSD alpha*-*-freebsd*
6473 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6474 MIPS GNU/Linux mips*-*-linux*
6475 MIPS SGI Irix 6.x mips*-sgi-irix6*
6476 ia64 AIX ia64-*-aix*
6477 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6481 Motorola 68HC11 and 68HC12 m68hc11-elf
6483 UltraSparc running GNU/Linux sparc64-*-linux*
6485 * OBSOLETE configurations and files
6487 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6488 Harris/CXUX m88k m88*-harris-cxux*
6489 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6490 ns32k-utek-sysv* ns32k-utek-*
6491 TI TMS320C80 tic80-*-*
6493 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6494 PowerPC Solaris powerpcle-*-solaris*
6495 PowerPC Windows NT powerpcle-*-cygwin32
6496 PowerPC Netware powerpc-*-netware*
6497 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6498 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6499 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6500 Apple Macintosh (MPW) host N/A
6502 stuff.c (Program to stuff files into a specially prepared space in kdb)
6503 kdb-start.c (Main loop for the standalone kernel debugger)
6505 Configurations that have been declared obsolete in this release have
6506 been commented out. Unless there is activity to revive these
6507 configurations, the next release of GDB will have their sources
6508 permanently REMOVED.
6510 * REMOVED configurations and files
6512 Altos 3068 m68*-altos-*
6513 Convex c1-*-*, c2-*-*
6515 ARM RISCix arm-*-* (as host)
6519 * GDB has been converted to ISO C.
6521 GDB's source code has been converted to ISO C. In particular, the
6522 sources are fully protoized, and rely on standard headers being
6527 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6529 * The MI enabled by default.
6531 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6532 revised and enabled by default. Packages which use GDB as a debugging
6533 engine behind a UI or another front end are encouraged to switch to
6534 using the GDB/MI interface, instead of the old annotations interface
6535 which is now deprecated.
6537 * Support for debugging Pascal programs.
6539 GDB now includes support for debugging Pascal programs. The following
6540 main features are supported:
6542 - Pascal-specific data types such as sets;
6544 - automatic recognition of Pascal sources based on file-name
6547 - Pascal-style display of data types, variables, and functions;
6549 - a Pascal expression parser.
6551 However, some important features are not yet supported.
6553 - Pascal string operations are not supported at all;
6555 - there are some problems with boolean types;
6557 - Pascal type hexadecimal constants are not supported
6558 because they conflict with the internal variables format;
6560 - support for Pascal objects and classes is not full yet;
6562 - unlike Pascal, GDB is case-sensitive for symbol names.
6564 * Changes in completion.
6566 Commands such as `shell', `run' and `set args', which pass arguments
6567 to inferior programs, now complete on file names, similar to what
6568 users expect at the shell prompt.
6570 Commands which accept locations, such as `disassemble', `print',
6571 `breakpoint', `until', etc. now complete on filenames as well as
6572 program symbols. Thus, if you type "break foob TAB", and the source
6573 files linked into the programs include `foobar.c', that file name will
6574 be one of the candidates for completion. However, file names are not
6575 considered for completion after you typed a colon that delimits a file
6576 name from a name of a function in that file, as in "break foo.c:bar".
6578 `set demangle-style' completes on available demangling styles.
6580 * New platform-independent commands:
6582 It is now possible to define a post-hook for a command as well as a
6583 hook that runs before the command. For more details, see the
6584 documentation of `hookpost' in the GDB manual.
6586 * Changes in GNU/Linux native debugging.
6588 Support for debugging multi-threaded programs has been completely
6589 revised for all platforms except m68k and sparc. You can now debug as
6590 many threads as your system allows you to have.
6592 Attach/detach is supported for multi-threaded programs.
6594 Support for SSE registers was added for x86. This doesn't work for
6595 multi-threaded programs though.
6597 * Changes in MIPS configurations.
6599 Multi-arch support is enabled for all MIPS configurations.
6601 GDB can now be built as native debugger on SGI Irix 6.x systems for
6602 debugging n32 executables. (Debugging 64-bit executables is not yet
6605 * Unified support for hardware watchpoints in all x86 configurations.
6607 Most (if not all) native x86 configurations support hardware-assisted
6608 breakpoints and watchpoints in a unified manner. This support
6609 implements debug register sharing between watchpoints, which allows to
6610 put a virtually infinite number of watchpoints on the same address,
6611 and also supports watching regions up to 16 bytes with several debug
6614 The new maintenance command `maintenance show-debug-regs' toggles
6615 debugging print-outs in functions that insert, remove, and test
6616 watchpoints and hardware breakpoints.
6618 * Changes in the DJGPP native configuration.
6620 New command ``info dos sysinfo'' displays assorted information about
6621 the CPU, OS, memory, and DPMI server.
6623 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6624 display information about segment descriptors stored in GDT, LDT, and
6627 New commands ``info dos pde'' and ``info dos pte'' display entries
6628 from Page Directory and Page Tables (for now works with CWSDPMI only).
6629 New command ``info dos address-pte'' displays the Page Table entry for
6630 a given linear address.
6632 GDB can now pass command lines longer than 126 characters to the
6633 program being debugged (requires an update to the libdbg.a library
6634 which is part of the DJGPP development kit).
6636 DWARF2 debug info is now supported.
6638 It is now possible to `step' and `next' through calls to `longjmp'.
6640 * Changes in documentation.
6642 All GDB documentation was converted to GFDL, the GNU Free
6643 Documentation License.
6645 Tracepoints-related commands are now fully documented in the GDB
6648 TUI, the Text-mode User Interface, is now documented in the manual.
6650 Tracepoints-related commands are now fully documented in the GDB
6653 The "GDB Internals" manual now has an index. It also includes
6654 documentation of `ui_out' functions, GDB coding standards, x86
6655 hardware watchpoints, and memory region attributes.
6657 * GDB's version number moved to ``version.in''
6659 The Makefile variable VERSION has been replaced by the file
6660 ``version.in''. People creating GDB distributions should update the
6661 contents of this file.
6665 GUD support is now a standard part of the EMACS distribution.
6667 *** Changes in GDB 5.0:
6669 * Improved support for debugging FP programs on x86 targets
6671 Unified and much-improved support for debugging floating-point
6672 programs on all x86 targets. In particular, ``info float'' now
6673 displays the FP registers in the same format on all x86 targets, with
6674 greater level of detail.
6676 * Improvements and bugfixes in hardware-assisted watchpoints
6678 It is now possible to watch array elements, struct members, and
6679 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6680 on x86 targets no longer erroneously trigger when the address is
6683 * Improvements in the native DJGPP version of GDB
6685 The distribution now includes all the scripts and auxiliary files
6686 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6687 machines ``out of the box''.
6689 The DJGPP version can now debug programs that use signals. It is
6690 possible to catch signals that happened in the debuggee, deliver
6691 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6692 would kill the program being debugged.) Programs that hook hardware
6693 interrupts (keyboard, timer, etc.) can also be debugged.
6695 It is now possible to debug DJGPP programs that redirect their
6696 standard handles or switch them to raw (as opposed to cooked) mode, or
6697 even close them. The command ``run < foo > bar'' works as expected,
6698 and ``info terminal'' reports useful information about the debuggee's
6699 terminal, including raw/cooked mode, redirection, etc.
6701 The DJGPP version now uses termios functions for console I/O, which
6702 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6705 DOS-style file names with drive letters are now fully supported by
6708 It is now possible to debug DJGPP programs that switch their working
6709 directory. It is also possible to rerun the debuggee any number of
6710 times without restarting GDB; thus, you can use the same setup,
6711 breakpoints, etc. for many debugging sessions.
6713 * New native configurations
6715 ARM GNU/Linux arm*-*-linux*
6716 PowerPC GNU/Linux powerpc-*-linux*
6720 Motorola MCore mcore-*-*
6721 x86 VxWorks i[3456]86-*-vxworks*
6722 PowerPC VxWorks powerpc-*-vxworks*
6723 TI TMS320C80 tic80-*-*
6725 * OBSOLETE configurations
6727 Altos 3068 m68*-altos-*
6728 Convex c1-*-*, c2-*-*
6730 ARM RISCix arm-*-* (as host)
6733 Configurations that have been declared obsolete will be commented out,
6734 but the code will be left in place. If there is no activity to revive
6735 these configurations before the next release of GDB, the sources will
6736 be permanently REMOVED.
6738 * Gould support removed
6740 Support for the Gould PowerNode and NP1 has been removed.
6742 * New features for SVR4
6744 On SVR4 native platforms (such as Solaris), if you attach to a process
6745 without first loading a symbol file, GDB will now attempt to locate and
6746 load symbols from the running process's executable file.
6748 * Many C++ enhancements
6750 C++ support has been greatly improved. Overload resolution now works properly
6751 in almost all cases. RTTI support is on the way.
6753 * Remote targets can connect to a sub-program
6755 A popen(3) style serial-device has been added. This device starts a
6756 sub-process (such as a stand-alone simulator) and then communicates
6757 with that. The sub-program to run is specified using the syntax
6758 ``|<program> <args>'' vis:
6760 (gdb) set remotedebug 1
6761 (gdb) target extended-remote |mn10300-elf-sim program-args
6763 * MIPS 64 remote protocol
6765 A long standing bug in the mips64 remote protocol where by GDB
6766 expected certain 32 bit registers (ex SR) to be transfered as 32
6767 instead of 64 bits has been fixed.
6769 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6770 added to provide backward compatibility with older versions of GDB.
6772 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6774 The command ``set remotebinarydownload'' command has been replaced by
6775 ``set remote X-packet''. Other commands in ``set remote'' family
6776 include ``set remote P-packet''.
6778 * Breakpoint commands accept ranges.
6780 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6781 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6782 ``tracepoint passcount'' also accepts a range of tracepoints.
6784 * ``apropos'' command added.
6786 The ``apropos'' command searches through command names and
6787 documentation strings, printing out matches, making it much easier to
6788 try to find a command that does what you are looking for.
6792 A new machine oriented interface (MI) has been added to GDB. This
6793 interface is designed for debug environments running GDB as a separate
6794 process. This is part of the long term libGDB project. See the
6795 "GDB/MI" chapter of the GDB manual for further information. It can be
6796 enabled by configuring with:
6798 .../configure --enable-gdbmi
6800 *** Changes in GDB-4.18:
6802 * New native configurations
6804 HP-UX 10.20 hppa*-*-hpux10.20
6805 HP-UX 11.x hppa*-*-hpux11.0*
6806 M68K GNU/Linux m68*-*-linux*
6810 Fujitsu FR30 fr30-*-elf*
6811 Intel StrongARM strongarm-*-*
6812 Mitsubishi D30V d30v-*-*
6814 * OBSOLETE configurations
6816 Gould PowerNode, NP1 np1-*-*, pn-*-*
6818 Configurations that have been declared obsolete will be commented out,
6819 but the code will be left in place. If there is no activity to revive
6820 these configurations before the next release of GDB, the sources will
6821 be permanently REMOVED.
6825 As a compatibility experiment, GDB's source files buildsym.h and
6826 buildsym.c have been converted to pure standard C, no longer
6827 containing any K&R compatibility code. We believe that all systems in
6828 use today either come with a standard C compiler, or have a GCC port
6829 available. If this is not true, please report the affected
6830 configuration to bug-gdb@gnu.org immediately. See the README file for
6831 information about getting a standard C compiler if you don't have one
6836 GDB now uses readline 2.2.
6838 * set extension-language
6840 You can now control the mapping between filename extensions and source
6841 languages by using the `set extension-language' command. For instance,
6842 you can ask GDB to treat .c files as C++ by saying
6843 set extension-language .c c++
6844 The command `info extensions' lists all of the recognized extensions
6845 and their associated languages.
6847 * Setting processor type for PowerPC and RS/6000
6849 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6850 you can use the `set processor' command to specify what variant of the
6851 PowerPC family you are debugging. The command
6855 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6856 following PowerPC and RS6000 variants:
6858 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6859 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6861 403GC IBM PowerPC 403GC
6862 505 Motorola PowerPC 505
6863 860 Motorola PowerPC 860 or 850
6864 601 Motorola PowerPC 601
6865 602 Motorola PowerPC 602
6866 603 Motorola/IBM PowerPC 603 or 603e
6867 604 Motorola PowerPC 604 or 604e
6868 750 Motorola/IBM PowerPC 750 or 750
6870 At the moment, this command just tells GDB what to name the
6871 special-purpose processor registers. Since almost all the affected
6872 registers are inaccessible to user-level programs, this command is
6873 only useful for remote debugging in its present form.
6877 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6878 more extensive support for HP-UX. Added features include shared
6879 library support, kernel threads and hardware watchpoints for 11.00,
6880 support for HP's ANSI C and C++ compilers, and a compatibility mode
6881 for xdb and dbx commands.
6885 HP's donation includes the new concept of catchpoints, which is a
6886 generalization of the old catch command. On HP-UX, it is now possible
6887 to catch exec, fork, and vfork, as well as library loading.
6889 This means that the existing catch command has changed; its first
6890 argument now specifies the type of catch to be set up. See the
6891 output of "help catch" for a list of catchpoint types.
6893 * Debugging across forks
6895 On HP-UX, you can choose which process to debug when a fork() happens
6900 HP has donated a curses-based terminal user interface (TUI). To get
6901 it, build with --enable-tui. Although this can be enabled for any
6902 configuration, at present it only works for native HP debugging.
6904 * GDB remote protocol additions
6906 A new protocol packet 'X' that writes binary data is now available.
6907 Default behavior is to try 'X', then drop back to 'M' if the stub
6908 fails to respond. The settable variable `remotebinarydownload'
6909 allows explicit control over the use of 'X'.
6911 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6912 full 64-bit address. The command
6914 set remoteaddresssize 32
6916 can be used to revert to the old behaviour. For existing remote stubs
6917 the change should not be noticed, as the additional address information
6920 In order to assist in debugging stubs, you may use the maintenance
6921 command `packet' to send any text string to the stub. For instance,
6923 maint packet heythere
6925 sends the packet "$heythere#<checksum>". Note that it is very easy to
6926 disrupt a debugging session by sending the wrong packet at the wrong
6929 The compare-sections command allows you to compare section data on the
6930 target to what is in the executable file without uploading or
6931 downloading, by comparing CRC checksums.
6933 * Tracing can collect general expressions
6935 You may now collect general expressions at tracepoints. This requires
6936 further additions to the target-side stub; see tracepoint.c and
6937 doc/agentexpr.texi for further details.
6939 * mask-address variable for Mips
6941 For Mips targets, you may control the zeroing of the upper 32 bits of
6942 a 64-bit address by entering `set mask-address on'. This is mainly
6943 of interest to users of embedded R4xxx and R5xxx processors.
6945 * Higher serial baud rates
6947 GDB's serial code now allows you to specify baud rates 57600, 115200,
6948 230400, and 460800 baud. (Note that your host system may not be able
6949 to achieve all of these rates.)
6953 The i960 configuration now includes an initial implementation of a
6954 builtin simulator, contributed by Jim Wilson.
6957 *** Changes in GDB-4.17:
6959 * New native configurations
6961 Alpha GNU/Linux alpha*-*-linux*
6962 Unixware 2.x i[3456]86-unixware2*
6963 Irix 6.x mips*-sgi-irix6*
6964 PowerPC GNU/Linux powerpc-*-linux*
6965 PowerPC Solaris powerpcle-*-solaris*
6966 Sparc GNU/Linux sparc-*-linux*
6967 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6971 Argonaut Risc Chip (ARC) arc-*-*
6972 Hitachi H8/300S h8300*-*-*
6973 Matsushita MN10200 w/simulator mn10200-*-*
6974 Matsushita MN10300 w/simulator mn10300-*-*
6975 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6976 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6977 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6978 Mitsubishi D10V w/simulator d10v-*-*
6979 Mitsubishi M32R/D w/simulator m32r-*-elf*
6980 Tsqware Sparclet sparclet-*-*
6981 NEC V850 w/simulator v850-*-*
6983 * New debugging protocols
6985 ARM with RDI protocol arm*-*-*
6986 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6987 DDB and LSI variants of PMON protocol mips*-*-*
6988 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6989 PowerPC with SDS protocol powerpc{,le}-*-eabi
6990 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6994 All configurations can now understand and use the DWARF 2 debugging
6995 format. The choice is automatic, if the symbol file contains DWARF 2
7000 GDB now includes basic Java language support. This support is
7001 only useful with Java compilers that produce native machine code.
7003 * solib-absolute-prefix and solib-search-path
7005 For SunOS and SVR4 shared libraries, you may now set the prefix for
7006 loading absolute shared library symbol files, and the search path for
7007 locating non-absolute shared library symbol files.
7009 * Live range splitting
7011 GDB can now effectively debug code for which GCC has performed live
7012 range splitting as part of its optimization. See gdb/doc/LRS for
7013 more details on the expected format of the stabs information.
7017 GDB's support for the GNU Hurd, including thread debugging, has been
7018 updated to work with current versions of the Hurd.
7022 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7023 instruction set. ARM GDB automatically detects when Thumb
7024 instructions are in use, and adjusts disassembly and backtracing
7029 GDB's MIPS target configurations now handle the MIP16 16-bit
7034 GDB now includes support for overlays; if an executable has been
7035 linked such that multiple sections are based at the same address, GDB
7036 will decide which section to use for symbolic info. You can choose to
7037 control the decision manually, using overlay commands, or implement
7038 additional target-side support and use "overlay load-target" to bring
7039 in the overlay mapping. Do "help overlay" for more detail.
7043 The command "info symbol <address>" displays information about
7044 the symbol at the specified address.
7048 The standard remote protocol now includes an extension that allows
7049 asynchronous collection and display of trace data. This requires
7050 extensive support in the target-side debugging stub. Tracing mode
7051 includes a new interaction mode in GDB and new commands: see the
7052 file tracepoint.c for more details.
7056 Configurations for embedded MIPS now include a simulator contributed
7057 by Cygnus Solutions. The simulator supports the instruction sets
7058 of most MIPS variants.
7062 Sparc configurations may now include the ERC32 simulator contributed
7063 by the European Space Agency. The simulator is not built into
7064 Sparc targets by default; configure with --enable-sim to include it.
7068 For target configurations that may include multiple variants of a
7069 basic architecture (such as MIPS and SH), you may now set the
7070 architecture explicitly. "set arch" sets, "info arch" lists
7071 the possible architectures.
7073 *** Changes in GDB-4.16:
7075 * New native configurations
7077 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7078 M68K NetBSD m68k-*-netbsd*
7079 PowerPC AIX 4.x powerpc-*-aix*
7080 PowerPC MacOS powerpc-*-macos*
7081 PowerPC Windows NT powerpcle-*-cygwin32
7082 RS/6000 AIX 4.x rs6000-*-aix4*
7086 ARM with RDP protocol arm-*-*
7087 I960 with MON960 i960-*-coff
7088 MIPS VxWorks mips*-*-vxworks*
7089 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7090 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7092 Matra Sparclet sparclet-*-*
7096 The powerpc-eabi configuration now includes the PSIM simulator,
7097 contributed by Andrew Cagney, with assistance from Mike Meissner.
7098 PSIM is a very elaborate model of the PowerPC, including not only
7099 basic instruction set execution, but also details of execution unit
7100 performance and I/O hardware. See sim/ppc/README for more details.
7104 GDB now works with Solaris 2.5.
7106 * Windows 95/NT native
7108 GDB will now work as a native debugger on Windows 95 and Windows NT.
7109 To build it from source, you must use the "gnu-win32" environment,
7110 which uses a DLL to emulate enough of Unix to run the GNU tools.
7111 Further information, binaries, and sources are available at
7112 ftp.cygnus.com, under pub/gnu-win32.
7114 * dont-repeat command
7116 If a user-defined command includes the command `dont-repeat', then the
7117 command will not be repeated if the user just types return. This is
7118 useful if the command is time-consuming to run, so that accidental
7119 extra keystrokes don't run the same command many times.
7121 * Send break instead of ^C
7123 The standard remote protocol now includes an option to send a break
7124 rather than a ^C to the target in order to interrupt it. By default,
7125 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7127 * Remote protocol timeout
7129 The standard remote protocol includes a new variable `remotetimeout'
7130 that allows you to set the number of seconds before GDB gives up trying
7131 to read from the target. The default value is 2.
7133 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7135 By default GDB will automatically keep track of objects as they are
7136 loaded and unloaded by the dynamic linker. By using the command `set
7137 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7138 when shared library events occur, thus allowing you to set breakpoints
7139 in shared libraries which are explicitly loaded by the inferior.
7141 Note this feature does not work on hpux8. On hpux9 you must link
7142 /usr/lib/end.o into your program. This feature should work
7143 automatically on hpux10.
7145 * Irix 5.x hardware watchpoint support
7147 Irix 5 configurations now support the use of hardware watchpoints.
7149 * Mips protocol "SYN garbage limit"
7151 When debugging a Mips target using the `target mips' protocol, you
7152 may set the number of characters that GDB will ignore by setting
7153 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7154 every character. The default value is 1050.
7156 * Recording and replaying remote debug sessions
7158 If you set `remotelogfile' to the name of a file, gdb will write to it
7159 a recording of a remote debug session. This recording may then be
7160 replayed back to gdb using "gdbreplay". See gdbserver/README for
7161 details. This is useful when you have a problem with GDB while doing
7162 remote debugging; you can make a recording of the session and send it
7163 to someone else, who can then recreate the problem.
7165 * Speedups for remote debugging
7167 GDB includes speedups for downloading and stepping MIPS systems using
7168 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7169 and more efficient S-record downloading.
7171 * Memory use reductions and statistics collection
7173 GDB now uses less memory and reports statistics about memory usage.
7174 Try the `maint print statistics' command, for example.
7176 *** Changes in GDB-4.15:
7178 * Psymtabs for XCOFF
7180 The symbol reader for AIX GDB now uses partial symbol tables. This
7181 can greatly improve startup time, especially for large executables.
7183 * Remote targets use caching
7185 Remote targets now use a data cache to speed up communication with the
7186 remote side. The data cache could lead to incorrect results because
7187 it doesn't know about volatile variables, thus making it impossible to
7188 debug targets which use memory mapped I/O devices. `set remotecache
7189 off' turns the data cache off.
7191 * Remote targets may have threads
7193 The standard remote protocol now includes support for multiple threads
7194 in the target system, using new protocol commands 'H' and 'T'. See
7195 gdb/remote.c for details.
7199 If GDB is configured with `--enable-netrom', then it will include
7200 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7201 acts as though it is a bank of ROM on the target board, but you can
7202 write into it over the network. GDB's support consists only of
7203 support for fast loading into the emulated ROM; to debug, you must use
7204 another protocol, such as standard remote protocol. The usual
7205 sequence is something like
7207 target nrom <netrom-hostname>
7209 target remote <netrom-hostname>:1235
7213 GDB now includes support for the Apple Macintosh, as a host only. It
7214 may be run as either an MPW tool or as a standalone application, and
7215 it can debug through the serial port. All the usual GDB commands are
7216 available, but to the target command, you must supply "serial" as the
7217 device type instead of "/dev/ttyXX". See mpw-README in the main
7218 directory for more information on how to build. The MPW configuration
7219 scripts */mpw-config.in support only a few targets, and only the
7220 mips-idt-ecoff target has been tested.
7224 GDB configuration now uses autoconf. This is not user-visible,
7225 but does simplify configuration and building.
7229 GDB now supports hpux10.
7231 *** Changes in GDB-4.14:
7233 * New native configurations
7235 x86 FreeBSD i[345]86-*-freebsd
7236 x86 NetBSD i[345]86-*-netbsd
7237 NS32k NetBSD ns32k-*-netbsd
7238 Sparc NetBSD sparc-*-netbsd
7242 A29K VxWorks a29k-*-vxworks
7243 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7244 CPU32 EST-300 emulator m68*-*-est*
7245 PowerPC ELF powerpc-*-elf
7248 * Alpha OSF/1 support for procfs
7250 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7251 possible to attach to running processes. As the mounting of the /proc
7252 filesystem is optional on the Alpha, GDB automatically determines
7253 the availability of /proc during startup. This can lead to problems
7254 if /proc is unmounted after GDB has been started.
7256 * Arguments to user-defined commands
7258 User commands may accept up to 10 arguments separated by whitespace.
7259 Arguments are accessed within the user command via $arg0..$arg9. A
7262 print $arg0 + $arg1 + $arg2
7264 To execute the command use:
7267 Defines the command "adder" which prints the sum of its three arguments.
7268 Note the arguments are text substitutions, so they may reference variables,
7269 use complex expressions, or even perform inferior function calls.
7271 * New `if' and `while' commands
7273 This makes it possible to write more sophisticated user-defined
7274 commands. Both commands take a single argument, which is the
7275 expression to evaluate, and must be followed by the commands to
7276 execute, one per line, if the expression is nonzero, the list being
7277 terminated by the word `end'. The `if' command list may include an
7278 `else' word, which causes the following commands to be executed only
7279 if the expression is zero.
7281 * Fortran source language mode
7283 GDB now includes partial support for Fortran 77. It will recognize
7284 Fortran programs and can evaluate a subset of Fortran expressions, but
7285 variables and functions may not be handled correctly. GDB will work
7286 with G77, but does not yet know much about symbols emitted by other
7289 * Better HPUX support
7291 Most debugging facilities now work on dynamic executables for HPPAs
7292 running hpux9 or later. You can attach to running dynamically linked
7293 processes, but by default the dynamic libraries will be read-only, so
7294 for instance you won't be able to put breakpoints in them. To change
7295 that behavior do the following before running the program:
7301 This will cause the libraries to be mapped private and read-write.
7302 To revert to the normal behavior, do this:
7308 You cannot set breakpoints or examine data in the library until after
7309 the library is loaded if the function/data symbols do not have
7312 GDB can now also read debug symbols produced by the HP C compiler on
7313 HPPAs (sorry, no C++, Fortran or 68k support).
7315 * Target byte order now dynamically selectable
7317 You can choose which byte order to use with a target system, via the
7318 commands "set endian big" and "set endian little", and you can see the
7319 current setting by using "show endian". You can also give the command
7320 "set endian auto", in which case GDB will use the byte order
7321 associated with the executable. Currently, only embedded MIPS
7322 configurations support dynamic selection of target byte order.
7324 * New DOS host serial code
7326 This version uses DPMI interrupts to handle buffered I/O, so you
7327 no longer need to run asynctsr when debugging boards connected to
7330 *** Changes in GDB-4.13:
7332 * New "complete" command
7334 This lists all the possible completions for the rest of the line, if it
7335 were to be given as a command itself. This is intended for use by emacs.
7337 * Trailing space optional in prompt
7339 "set prompt" no longer adds a space for you after the prompt you set. This
7340 allows you to set a prompt which ends in a space or one that does not.
7342 * Breakpoint hit counts
7344 "info break" now displays a count of the number of times the breakpoint
7345 has been hit. This is especially useful in conjunction with "ignore"; you
7346 can ignore a large number of breakpoint hits, look at the breakpoint info
7347 to see how many times the breakpoint was hit, then run again, ignoring one
7348 less than that number, and this will get you quickly to the last hit of
7351 * Ability to stop printing at NULL character
7353 "set print null-stop" will cause GDB to stop printing the characters of
7354 an array when the first NULL is encountered. This is useful when large
7355 arrays actually contain only short strings.
7357 * Shared library breakpoints
7359 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7360 breakpoints in shared libraries before the executable is run.
7362 * Hardware watchpoints
7364 There is a new hardware breakpoint for the watch command for sparclite
7365 targets. See gdb/sparclite/hw_breakpoint.note.
7367 Hardware watchpoints are also now supported under GNU/Linux.
7371 Annotations have been added. These are for use with graphical interfaces,
7372 and are still experimental. Currently only gdba.el uses these.
7374 * Improved Irix 5 support
7376 GDB now works properly with Irix 5.2.
7378 * Improved HPPA support
7380 GDB now works properly with the latest GCC and GAS.
7382 * New native configurations
7384 Sequent PTX4 i[34]86-sequent-ptx4
7385 HPPA running OSF/1 hppa*-*-osf*
7386 Atari TT running SVR4 m68*-*-sysv4*
7387 RS/6000 LynxOS rs6000-*-lynxos*
7391 OS/9000 i[34]86-*-os9k
7392 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7395 * Hitachi SH7000 and E7000-PC ICE support
7397 There is now support for communicating with the Hitachi E7000-PC ICE.
7398 This is available automatically when GDB is configured for the SH.
7402 As usual, a variety of small fixes and improvements, both generic
7403 and configuration-specific. See the ChangeLog for more detail.
7405 *** Changes in GDB-4.12:
7407 * Irix 5 is now supported
7411 GDB-4.12 on the HPPA has a number of changes which make it unable
7412 to debug the output from the currently released versions of GCC and
7413 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7414 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7415 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7418 *** Changes in GDB-4.11:
7420 * User visible changes:
7424 The "set remotedebug" option is now consistent between the mips remote
7425 target, remote targets using the gdb-specific protocol, UDI (AMD's
7426 debug protocol for the 29k) and the 88k bug monitor. It is now an
7427 integer specifying a debug level (normally 0 or 1, but 2 means more
7428 debugging info for the mips target).
7430 * DEC Alpha native support
7432 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7433 debug info, but GDB works fairly well with the DEC compiler and should
7434 work with a future GCC release. See the README file for a few
7435 Alpha-specific notes.
7437 * Preliminary thread implementation
7439 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7441 * LynxOS native and target support for 386
7443 This release has been hosted on LynxOS 2.2, and also can be configured
7444 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7447 * Improvements in C++ mangling/demangling.
7449 This release has much better g++ debugging, specifically in name
7450 mangling/demangling, virtual function calls, print virtual table,
7451 call methods, ...etc.
7453 *** Changes in GDB-4.10:
7455 * User visible changes:
7457 Remote debugging using the GDB-specific (`target remote') protocol now
7458 supports the `load' command. This is only useful if you have some
7459 other way of getting the stub to the target system, and you can put it
7460 somewhere in memory where it won't get clobbered by the download.
7462 Filename completion now works.
7464 When run under emacs mode, the "info line" command now causes the
7465 arrow to point to the line specified. Also, "info line" prints
7466 addresses in symbolic form (as well as hex).
7468 All vxworks based targets now support a user settable option, called
7469 vxworks-timeout. This option represents the number of seconds gdb
7470 should wait for responses to rpc's. You might want to use this if
7471 your vxworks target is, perhaps, a slow software simulator or happens
7472 to be on the far side of a thin network line.
7476 This release contains support for using a DEC alpha as a GDB host for
7477 cross debugging. Native alpha debugging is not supported yet.
7480 *** Changes in GDB-4.9:
7484 This is the first GDB release which is accompanied by a matching testsuite.
7485 The testsuite requires installation of dejagnu, which should be available
7486 via ftp from most sites that carry GNU software.
7490 'Cfront' style demangling has had its name changed to 'ARM' style, to
7491 emphasize that it was written from the specifications in the C++ Annotated
7492 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7493 disclaimers, it still generated too much confusion with users attempting to
7494 use gdb with AT&T cfront.
7498 GDB now uses a standard remote interface to a simulator library.
7499 So far, the library contains simulators for the Zilog Z8001/2, the
7500 Hitachi H8/300, H8/500 and Super-H.
7502 * New targets supported
7504 H8/300 simulator h8300-hitachi-hms or h8300hms
7505 H8/500 simulator h8500-hitachi-hms or h8500hms
7506 SH simulator sh-hitachi-hms or sh
7507 Z8000 simulator z8k-zilog-none or z8ksim
7508 IDT MIPS board over serial line mips-idt-ecoff
7510 Cross-debugging to GO32 targets is supported. It requires a custom
7511 version of the i386-stub.c module which is integrated with the
7512 GO32 memory extender.
7514 * New remote protocols
7516 MIPS remote debugging protocol.
7518 * New source languages supported
7520 This version includes preliminary support for Chill, a Pascal like language
7521 used by telecommunications companies. Chill support is also being integrated
7522 into the GNU compiler, but we don't know when it will be publically available.
7525 *** Changes in GDB-4.8:
7527 * HP Precision Architecture supported
7529 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7530 version of this support was available as a set of patches from the
7531 University of Utah. GDB does not support debugging of programs
7532 compiled with the HP compiler, because HP will not document their file
7533 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7534 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7536 Many problems in the preliminary version have been fixed.
7538 * Faster and better demangling
7540 We have improved template demangling and fixed numerous bugs in the GNU style
7541 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7542 character types (wchar_t) are now supported. Demangling of each symbol is now
7543 only done once, and is cached when the symbol table for a file is read in.
7544 This results in a small increase in memory usage for C programs, a moderate
7545 increase in memory usage for C++ programs, and a fantastic speedup in
7548 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7549 from the specifications in the Annotated Reference Manual, which AT&T's
7550 compiler does not actually implement.
7552 * G++ multiple inheritance compiler problem
7554 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7555 inheritance lattices was reworked to properly discover ambiguities. We
7556 recently found an example which causes this new algorithm to fail in a
7557 very subtle way, producing bad debug information for those classes.
7558 The file 'gcc.patch' (in this directory) can be applied to gcc to
7559 circumvent the problem. A future GCC release will contain a complete
7562 The previous G++ debug info problem (mentioned below for the gdb-4.7
7563 release) is fixed in gcc version 2.3.2.
7565 * Improved configure script
7567 The `configure' script will now attempt to guess your system type if
7568 you don't supply a host system type. The old scheme of supplying a
7569 host system triplet is preferable over using this. All the magic is
7570 done in the new `config.guess' script. Examine it for details.
7572 We have also brought our configure script much more in line with the FSF's
7573 version. It now supports the --with-xxx options. In particular,
7574 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7575 The resulting GDB will not be able to read arbitrary object file formats --
7576 only the format ``expected'' to be used on the configured target system.
7577 We hope to make this the default in a future release.
7579 * Documentation improvements
7581 There's new internal documentation on how to modify GDB, and how to
7582 produce clean changes to the code. We implore people to read it
7583 before submitting changes.
7585 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7586 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7587 `info' files are also provided. To build `info' files from scratch,
7588 you will need the latest `makeinfo' release, which will be available in
7589 a future texinfo-X.Y release.
7591 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7592 We're not sure exactly which versions have this problem, but it has
7593 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7594 or better. If that isn't possible, there is a patch in
7595 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7596 around this problem.
7600 GDB now supports array constants that can be used in expressions typed in by
7601 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7602 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7605 The new directory `gdb/sparclite' contains a program that demonstrates
7606 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7608 * New native hosts supported
7610 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7611 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7613 * New targets supported
7615 AMD 29k family via UDI a29k-amd-udi or udi29k
7617 * New file formats supported
7619 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7620 HPUX core files, and SCO 3.2v2 core files.
7624 Attaching to processes now works again; thanks for the many bug reports.
7626 We have also stomped on a bunch of core dumps caused by
7627 printf_filtered("%s") problems.
7629 We eliminated a copyright problem on the rpc and ptrace header files
7630 for VxWorks, which was discovered at the last minute during the 4.7
7631 release. You should now be able to build a VxWorks GDB.
7633 You can now interrupt gdb while an attached process is running. This
7634 will cause the attached process to stop, and give control back to GDB.
7636 We fixed problems caused by using too many file descriptors
7637 for reading symbols from object files and libraries. This was
7638 especially a problem for programs that used many (~100) shared
7641 The `step' command now only enters a subroutine if there is line number
7642 information for the subroutine. Otherwise it acts like the `next'
7643 command. Previously, `step' would enter subroutines if there was
7644 any debugging information about the routine. This avoids problems
7645 when using `cc -g1' on MIPS machines.
7647 * Internal improvements
7649 GDB's internal interfaces have been improved to make it easier to support
7650 debugging of multiple languages in the future.
7652 GDB now uses a common structure for symbol information internally.
7653 Minimal symbols (derived from linkage symbols in object files), partial
7654 symbols (from a quick scan of debug information), and full symbols
7655 contain a common subset of information, making it easier to write
7656 shared code that handles any of them.
7658 * New command line options
7660 We now accept --silent as an alias for --quiet.
7664 The memory-mapped-malloc library is now licensed under the GNU Library
7665 General Public License.
7667 *** Changes in GDB-4.7:
7669 * Host/native/target split
7671 GDB has had some major internal surgery to untangle the support for
7672 hosts and remote targets. Now, when you configure GDB for a remote
7673 target, it will no longer load in all of the support for debugging
7674 local programs on the host. When fully completed and tested, this will
7675 ensure that arbitrary host/target combinations are possible.
7677 The primary conceptual shift is to separate the non-portable code in
7678 GDB into three categories. Host specific code is required any time GDB
7679 is compiled on that host, regardless of the target. Target specific
7680 code relates to the peculiarities of the target, but can be compiled on
7681 any host. Native specific code is everything else: it can only be
7682 built when the host and target are the same system. Child process
7683 handling and core file support are two common `native' examples.
7685 GDB's use of /proc for controlling Unix child processes is now cleaner.
7686 It has been split out into a single module under the `target_ops' vector,
7687 plus two native-dependent functions for each system that uses /proc.
7689 * New hosts supported
7691 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7692 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7693 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7695 * New targets supported
7697 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7698 68030 and CPU32 m68030-*-*, m68332-*-*
7700 * New native hosts supported
7702 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7703 (386bsd is not well tested yet)
7704 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7706 * New file formats supported
7708 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7709 supports reading of `a.out.adobe' object files, which are an a.out
7710 format extended with minimal information about multiple sections.
7714 `show copying' is the same as the old `info copying'.
7715 `show warranty' is the same as `info warrantee'.
7716 These were renamed for consistency. The old commands continue to work.
7718 `info handle' is a new alias for `info signals'.
7720 You can now define pre-command hooks, which attach arbitrary command
7721 scripts to any command. The commands in the hook will be executed
7722 prior to the user's command. You can also create a hook which will be
7723 executed whenever the program stops. See gdb.texinfo.
7727 We now deal with Cfront style name mangling, and can even extract type
7728 info from mangled symbols. GDB can automatically figure out which
7729 symbol mangling style your C++ compiler uses.
7731 Calling of methods and virtual functions has been improved as well.
7735 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7736 fixed. This was due to mishandling of the extra N_SO stabs output
7739 We also finally got Ultrix 4.2 running in house, and fixed core file
7740 support, with help from a dozen people on the net.
7742 John M. Farrell discovered that the reason that single-stepping was so
7743 slow on all of the Mips based platforms (primarily SGI and DEC) was
7744 that we were trying to demangle and lookup a symbol used for internal
7745 purposes on every instruction that was being stepped through. Changing
7746 the name of that symbol so that it couldn't be mistaken for a C++
7747 mangled symbol sped things up a great deal.
7749 Rich Pixley sped up symbol lookups in general by getting much smarter
7750 about when C++ symbol mangling is necessary. This should make symbol
7751 completion (TAB on the command line) much faster. It's not as fast as
7752 we'd like, but it's significantly faster than gdb-4.6.
7756 A new user controllable variable 'call_scratch_address' can
7757 specify the location of a scratch area to be used when GDB
7758 calls a function in the target. This is necessary because the
7759 usual method of putting the scratch area on the stack does not work
7760 in systems that have separate instruction and data spaces.
7762 We integrated changes to support the 29k UDI (Universal Debugger
7763 Interface), but discovered at the last minute that we didn't have all
7764 of the appropriate copyright paperwork. We are working with AMD to
7765 resolve this, and hope to have it available soon.
7769 We have sped up the remote serial line protocol, especially for targets
7770 with lots of registers. It now supports a new `expedited status' ('T')
7771 message which can be used in place of the existing 'S' status message.
7772 This allows the remote stub to send only the registers that GDB
7773 needs to make a quick decision about single-stepping or conditional
7774 breakpoints, eliminating the need to fetch the entire register set for
7775 each instruction being stepped through.
7777 The GDB remote serial protocol now implements a write-through cache for
7778 registers, only re-reading the registers if the target has run.
7780 There is also a new remote serial stub for SPARC processors. You can
7781 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7782 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7783 processor with a serial port.
7787 Configure.in files have become much easier to read and modify. A new
7788 `table driven' format makes it more obvious what configurations are
7789 supported, and what files each one uses.
7793 There is a new opcodes library which will eventually contain all of the
7794 disassembly routines and opcode tables. At present, it only contains
7795 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7796 disassembler (binutils/objdump) to share these routines.
7798 The libiberty library is now copylefted under the GNU Library General
7799 Public License. This allows more liberal use, and was done so libg++
7800 can use it. This makes no difference to GDB, since the Library License
7801 grants all the rights from the General Public License.
7805 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7806 reference to the stabs symbol info used by the debugger. It is (as far
7807 as we know) the only published document on this fascinating topic. We
7808 encourage you to read it, compare it to the stabs information on your
7809 system, and send improvements on the document in general (to
7810 bug-gdb@prep.ai.mit.edu).
7812 And, of course, many bugs have been fixed.
7815 *** Changes in GDB-4.6:
7817 * Better support for C++ function names
7819 GDB now accepts as input the "demangled form" of C++ overloaded function
7820 names and member function names, and can do command completion on such names
7821 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7822 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7823 Make use of command completion, it is your friend.
7825 GDB also now accepts a variety of C++ mangled symbol formats. They are
7826 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7827 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7828 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7829 for the list of formats.
7831 * G++ symbol mangling problem
7833 Recent versions of gcc have a bug in how they emit debugging information for
7834 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7835 directory) can be applied to gcc to fix the problem. Alternatively, if you
7836 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7837 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7838 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7841 * New 'maintenance' command
7843 All of the commands related to hacking GDB internals have been moved out of
7844 the main command set, and now live behind the 'maintenance' command. This
7845 can also be abbreviated as 'mt'. The following changes were made:
7847 dump-me -> maintenance dump-me
7848 info all-breakpoints -> maintenance info breakpoints
7849 printmsyms -> maintenance print msyms
7850 printobjfiles -> maintenance print objfiles
7851 printpsyms -> maintenance print psymbols
7852 printsyms -> maintenance print symbols
7854 The following commands are new:
7856 maintenance demangle Call internal GDB demangler routine to
7857 demangle a C++ link name and prints the result.
7858 maintenance print type Print a type chain for a given symbol
7860 * Change to .gdbinit file processing
7862 We now read the $HOME/.gdbinit file before processing the argv arguments
7863 (e.g. reading symbol files or core files). This allows global parameters to
7864 be set, which will apply during the symbol reading. The ./.gdbinit is still
7865 read after argv processing.
7867 * New hosts supported
7869 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7871 GNU/Linux support i386-unknown-linux or linux
7873 We are also including code to support the HP/PA running BSD and HPUX. This
7874 is almost guaranteed not to work, as we didn't have time to test or build it
7875 for this release. We are including it so that the more adventurous (or
7876 masochistic) of you can play with it. We also had major problems with the
7877 fact that the compiler that we got from HP doesn't support the -g option.
7880 * New targets supported
7882 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7884 * More smarts about finding #include files
7886 GDB now remembers the compilation directory for all include files, and for
7887 all files from which C is generated (like yacc and lex sources). This
7888 greatly improves GDB's ability to find yacc/lex sources, and include files,
7889 especially if you are debugging your program from a directory different from
7890 the one that contains your sources.
7892 We also fixed a bug which caused difficulty with listing and setting
7893 breakpoints in include files which contain C code. (In the past, you had to
7894 try twice in order to list an include file that you hadn't looked at before.)
7896 * Interesting infernals change
7898 GDB now deals with arbitrary numbers of sections, where the symbols for each
7899 section must be relocated relative to that section's landing place in the
7900 target's address space. This work was needed to support ELF with embedded
7901 stabs used by Solaris-2.0.
7903 * Bug fixes (of course!)
7905 There have been loads of fixes for the following things:
7906 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7907 i960, stabs, DOS(GO32), procfs, etc...
7909 See the ChangeLog for details.
7911 *** Changes in GDB-4.5:
7913 * New machines supported (host and target)
7915 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7917 SGI Irix-4.x mips-sgi-irix4 or iris4
7919 * New malloc package
7921 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7922 Mmalloc is capable of handling multiple heaps of memory. It is also
7923 capable of saving a heap to a file, and then mapping it back in later.
7924 This can be used to greatly speedup the startup of GDB by using a
7925 pre-parsed symbol table which lives in a mmalloc managed heap. For
7926 more details, please read mmalloc/mmalloc.texi.
7930 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7931 'help info proc' for details.
7933 * MIPS ecoff symbol table format
7935 The code that reads MIPS symbol table format is now supported on all hosts.
7936 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7939 * File name changes for MS-DOS
7941 Many files in the config directories have been renamed to make it easier to
7942 support GDB on MS-DOSe systems (which have very restrictive file name
7943 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7944 environment) is close to working but has some remaining problems. Note
7945 that debugging of DOS programs is not supported, due to limitations
7946 in the ``operating system'', but it can be used to host cross-debugging.
7948 * Cross byte order fixes
7950 Many fixes have been made to support cross debugging of Sparc and MIPS
7951 targets from hosts whose byte order differs.
7953 * New -mapped and -readnow options
7955 If memory-mapped files are available on your system through the 'mmap'
7956 system call, you can use the -mapped option on the `file' or
7957 `symbol-file' commands to cause GDB to write the symbols from your
7958 program into a reusable file. If the program you are debugging is
7959 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7960 Future GDB debugging sessions will notice the presence of this file,
7961 and will quickly map in symbol information from it, rather than reading
7962 the symbol table from the executable program. Using the '-mapped'
7963 option in a GDB `file' or `symbol-file' command has the same effect as
7964 starting GDB with the '-mapped' command-line option.
7966 You can cause GDB to read the entire symbol table immediately by using
7967 the '-readnow' option with any of the commands that load symbol table
7968 information (or on the GDB command line). This makes the command
7969 slower, but makes future operations faster.
7971 The -mapped and -readnow options are typically combined in order to
7972 build a `fred.syms' file that contains complete symbol information.
7973 A simple GDB invocation to do nothing but build a `.syms' file for future
7976 gdb -batch -nx -mapped -readnow programname
7978 The `.syms' file is specific to the host machine on which GDB is run.
7979 It holds an exact image of GDB's internal symbol table. It cannot be
7980 shared across multiple host platforms.
7982 * longjmp() handling
7984 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7985 siglongjmp() without losing control. This feature has not yet been ported to
7986 all systems. It currently works on many 386 platforms, all MIPS-based
7987 platforms (SGI, DECstation, etc), and Sun3/4.
7991 Preliminary work has been put in to support the new Solaris OS from Sun. At
7992 this time, it can control and debug processes, but it is not capable of
7997 As always, many many bug fixes. The major areas were with g++, and mipsread.
7998 People using the MIPS-based platforms should experience fewer mysterious
7999 crashes and trashed symbol tables.
8001 *** Changes in GDB-4.4:
8003 * New machines supported (host and target)
8005 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8007 BSD Reno on Vax vax-dec-bsd
8008 Ultrix on Vax vax-dec-ultrix
8010 * New machines supported (target)
8012 AMD 29000 embedded, using EBMON a29k-none-none
8016 GDB continues to improve its handling of C++. `References' work better.
8017 The demangler has also been improved, and now deals with symbols mangled as
8018 per the Annotated C++ Reference Guide.
8020 GDB also now handles `stabs' symbol information embedded in MIPS
8021 `ecoff' symbol tables. Since the ecoff format was not easily
8022 extensible to handle new languages such as C++, this appeared to be a
8023 good way to put C++ debugging info into MIPS binaries. This option
8024 will be supported in the GNU C compiler, version 2, when it is
8027 * New features for SVR4
8029 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8030 shared libraries. Debugging dynamically linked programs should present
8031 only minor differences from debugging statically linked programs.
8033 The `info proc' command will print out information about any process
8034 on an SVR4 system (including the one you are debugging). At the moment,
8035 it prints the address mappings of the process.
8037 If you bring up GDB on another SVR4 system, please send mail to
8038 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8040 * Better dynamic linking support in SunOS
8042 Reading symbols from shared libraries which contain debugging symbols
8043 now works properly. However, there remain issues such as automatic
8044 skipping of `transfer vector' code during function calls, which
8045 make it harder to debug code in a shared library, than to debug the
8046 same code linked statically.
8050 GDB is now using the latest `getopt' routines from the FSF. This
8051 version accepts the -- prefix for options with long names. GDB will
8052 continue to accept the old forms (-option and +option) as well.
8053 Various single letter abbreviations for options have been explicity
8054 added to the option table so that they won't get overshadowed in the
8055 future by other options that begin with the same letter.
8059 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8060 Many assorted bugs have been handled. Many more remain to be handled.
8061 See the various ChangeLog files (primarily in gdb and bfd) for details.
8064 *** Changes in GDB-4.3:
8066 * New machines supported (host and target)
8068 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8069 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8070 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8072 * Almost SCO Unix support
8074 We had hoped to support:
8075 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8076 (except for core file support), but we discovered very late in the release
8077 that it has problems with process groups that render gdb unusable. Sorry
8078 about that. I encourage people to fix it and post the fixes.
8080 * Preliminary ELF and DWARF support
8082 GDB can read ELF object files on System V Release 4, and can handle
8083 debugging records for C, in DWARF format, in ELF files. This support
8084 is preliminary. If you bring up GDB on another SVR4 system, please
8085 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8090 GDB now uses the latest `readline' library. One user-visible change
8091 is that two tabs will list possible command completions, which previously
8092 required typing M-? (meta-question mark, or ESC ?).
8096 The `stepi' bug that many of you noticed has been squashed.
8097 Many bugs in C++ have been handled. Many more remain to be handled.
8098 See the various ChangeLog files (primarily in gdb and bfd) for details.
8100 * State of the MIPS world (in case you wondered):
8102 GDB can understand the symbol tables emitted by the compilers
8103 supplied by most vendors of MIPS-based machines, including DEC. These
8104 symbol tables are in a format that essentially nobody else uses.
8106 Some versions of gcc come with an assembler post-processor called
8107 mips-tfile. This program is required if you want to do source-level
8108 debugging of gcc-compiled programs. I believe FSF does not ship
8109 mips-tfile with gcc version 1, but it will eventually come with gcc
8112 Debugging of g++ output remains a problem. g++ version 1.xx does not
8113 really support it at all. (If you're lucky, you should be able to get
8114 line numbers and stack traces to work, but no parameters or local
8115 variables.) With some work it should be possible to improve the
8118 When gcc version 2 is released, you will have somewhat better luck.
8119 However, even then you will get confusing results for inheritance and
8122 We will eventually provide full debugging of g++ output on
8123 DECstations. This will probably involve some kind of stabs-in-ecoff
8124 encapulation, but the details have not been worked out yet.
8127 *** Changes in GDB-4.2:
8129 * Improved configuration
8131 Only one copy of `configure' exists now, and it is not self-modifying.
8132 Porting BFD is simpler.
8136 The `step' and `next' commands now only stop at the first instruction
8137 of a source line. This prevents the multiple stops that used to occur
8138 in switch statements, for-loops, etc. `Step' continues to stop if a
8139 function that has debugging information is called within the line.
8143 Lots of small bugs fixed. More remain.
8145 * New host supported (not target)
8147 Intel 386 PC clone running Mach i386-none-mach
8150 *** Changes in GDB-4.1:
8152 * Multiple source language support
8154 GDB now has internal scaffolding to handle several source languages.
8155 It determines the type of each source file from its filename extension,
8156 and will switch expression parsing and number formatting to match the
8157 language of the function in the currently selected stack frame.
8158 You can also specifically set the language to be used, with
8159 `set language c' or `set language modula-2'.
8163 GDB now has preliminary support for the GNU Modula-2 compiler,
8164 currently under development at the State University of New York at
8165 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8166 continue through the fall of 1991 and into 1992.
8168 Other Modula-2 compilers are currently not supported, and attempting to
8169 debug programs compiled with them will likely result in an error as the
8170 symbol table is read. Feel free to work on it, though!
8172 There are hooks in GDB for strict type checking and range checking,
8173 in the `Modula-2 philosophy', but they do not currently work.
8177 GDB can now write to executable and core files (e.g. patch
8178 a variable's value). You must turn this switch on, specify
8179 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8180 by assigning a new value to a variable. Modifications take
8183 * Automatic SunOS shared library reading
8185 When you run your program, GDB automatically determines where its
8186 shared libraries (if any) have been loaded, and reads their symbols.
8187 The `share' command is no longer needed. This also works when
8188 examining core files.
8192 You can specify the number of lines that the `list' command shows.
8195 * New machines supported (host and target)
8197 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8198 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8199 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8201 * New hosts supported (not targets)
8203 IBM RT/PC: romp-ibm-aix or rtpc
8205 * New targets supported (not hosts)
8207 AMD 29000 embedded with COFF a29k-none-coff
8208 AMD 29000 embedded with a.out a29k-none-aout
8209 Ultracomputer remote kernel debug a29k-nyu-kern
8211 * New remote interfaces
8217 *** Changes in GDB-4.0:
8221 Wide output is wrapped at good places to make the output more readable.
8223 Gdb now supports cross-debugging from a host machine of one type to a
8224 target machine of another type. Communication with the target system
8225 is over serial lines. The ``target'' command handles connecting to the
8226 remote system; the ``load'' command will download a program into the
8227 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8228 also supports debugging of realtime processes running under VxWorks,
8229 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8230 stub on the target system.
8232 New CPUs supported include the AMD 29000 and Intel 960.
8234 GDB now reads object files and symbol tables via a ``binary file''
8235 library, which allows a single copy of GDB to debug programs of multiple
8236 object file types such as a.out and coff.
8238 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8239 refcard.dvi and refcard.ps are available to format it).
8242 * Control-Variable user interface simplified
8244 All variables that control the operation of the debugger can be set
8245 by the ``set'' command, and displayed by the ``show'' command.
8247 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8248 ``Show prompt'' produces the response:
8249 Gdb's prompt is new-gdb=>.
8251 What follows are the NEW set commands. The command ``help set'' will
8252 print a complete list of old and new set commands. ``help set FOO''
8253 will give a longer description of the variable FOO. ``show'' will show
8254 all of the variable descriptions and their current settings.
8256 confirm on/off: Enables warning questions for operations that are
8257 hard to recover from, e.g. rerunning the program while
8258 it is already running. Default is ON.
8260 editing on/off: Enables EMACS style command line editing
8261 of input. Previous lines can be recalled with
8262 control-P, the current line can be edited with control-B,
8263 you can search for commands with control-R, etc.
8266 history filename NAME: NAME is where the gdb command history
8267 will be stored. The default is .gdb_history,
8268 or the value of the environment variable
8271 history size N: The size, in commands, of the command history. The
8272 default is 256, or the value of the environment variable
8275 history save on/off: If this value is set to ON, the history file will
8276 be saved after exiting gdb. If set to OFF, the
8277 file will not be saved. The default is OFF.
8279 history expansion on/off: If this value is set to ON, then csh-like
8280 history expansion will be performed on
8281 command line input. The default is OFF.
8283 radix N: Sets the default radix for input and output. It can be set
8284 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8285 in the current radix, so "set radix 10" is always a no-op.
8287 height N: This integer value is the number of lines on a page. Default
8288 is 24, the current `stty rows'' setting, or the ``li#''
8289 setting from the termcap entry matching the environment
8292 width N: This integer value is the number of characters on a line.
8293 Default is 80, the current `stty cols'' setting, or the ``co#''
8294 setting from the termcap entry matching the environment
8297 Note: ``set screensize'' is obsolete. Use ``set height'' and
8298 ``set width'' instead.
8300 print address on/off: Print memory addresses in various command displays,
8301 such as stack traces and structure values. Gdb looks
8302 more ``symbolic'' if you turn this off; it looks more
8303 ``machine level'' with it on. Default is ON.
8305 print array on/off: Prettyprint arrays. New convenient format! Default
8308 print demangle on/off: Print C++ symbols in "source" form if on,
8311 print asm-demangle on/off: Same, for assembler level printouts
8314 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8317 * Support for Epoch Environment.
8319 The epoch environment is a version of Emacs v18 with windowing. One
8320 new command, ``inspect'', is identical to ``print'', except that if you
8321 are running in the epoch environment, the value is printed in its own
8325 * Support for Shared Libraries
8327 GDB can now debug programs and core files that use SunOS shared libraries.
8328 Symbols from a shared library cannot be referenced
8329 before the shared library has been linked with the program (this
8330 happens after you type ``run'' and before the function main() is entered).
8331 At any time after this linking (including when examining core files
8332 from dynamically linked programs), gdb reads the symbols from each
8333 shared library when you type the ``sharedlibrary'' command.
8334 It can be abbreviated ``share''.
8336 sharedlibrary REGEXP: Load shared object library symbols for files
8337 matching a unix regular expression. No argument
8338 indicates to load symbols for all shared libraries.
8340 info sharedlibrary: Status of loaded shared libraries.
8345 A watchpoint stops execution of a program whenever the value of an
8346 expression changes. Checking for this slows down execution
8347 tremendously whenever you are in the scope of the expression, but is
8348 quite useful for catching tough ``bit-spreader'' or pointer misuse
8349 problems. Some machines such as the 386 have hardware for doing this
8350 more quickly, and future versions of gdb will use this hardware.
8352 watch EXP: Set a watchpoint (breakpoint) for an expression.
8354 info watchpoints: Information about your watchpoints.
8356 delete N: Deletes watchpoint number N (same as breakpoints).
8357 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8358 enable N: Re-enables watchpoint number N (same as breakpoints).
8361 * C++ multiple inheritance
8363 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8366 * C++ exception handling
8368 Gdb now supports limited C++ exception handling. Besides the existing
8369 ability to breakpoint on an exception handler, gdb can breakpoint on
8370 the raising of an exception (before the stack is peeled back to the
8373 catch FOO: If there is a FOO exception handler in the dynamic scope,
8374 set a breakpoint to catch exceptions which may be raised there.
8375 Multiple exceptions (``catch foo bar baz'') may be caught.
8377 info catch: Lists all exceptions which may be caught in the
8378 current stack frame.
8381 * Minor command changes
8383 The command ``call func (arg, arg, ...)'' now acts like the print
8384 command, except it does not print or save a value if the function's result
8385 is void. This is similar to dbx usage.
8387 The ``up'' and ``down'' commands now always print the frame they end up
8388 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8389 frames without printing.
8391 * New directory command
8393 'dir' now adds directories to the FRONT of the source search path.
8394 The path starts off empty. Source files that contain debug information
8395 about the directory in which they were compiled can be found even
8396 with an empty path; Sun CC and GCC include this information. If GDB can't
8397 find your source file in the current directory, type "dir .".
8399 * Configuring GDB for compilation
8401 For normal use, type ``./configure host''. See README or gdb.texinfo
8404 GDB now handles cross debugging. If you are remotely debugging between
8405 two different machines, type ``./configure host -target=targ''.
8406 Host is the machine where GDB will run; targ is the machine
8407 where the program that you are debugging will run.