1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 11
8 maint set backtrace-on-fatal-signal on|off
9 maint show backtrace-on-fatal-signal
10 This setting is 'on' by default. When 'on' GDB will print a limited
11 backtrace to stderr in the situation where GDB terminates with a
12 fatal signal. This only supported on some platforms where the
13 backtrace and backtrace_symbols_fd functions are available.
15 set source open on|off
17 This setting, which is on by default, controls whether GDB will try
18 to open source code files. Switching this off will stop GDB trying
19 to open and read source code files, which can be useful if the files
20 are located over a slow network connection.
24 These are now deprecated aliases for "set max-value-size" and
25 "show max-value-size".
27 maint set internal-error backtrace on|off
28 maint show internal-error backtrace
29 maint set internal-warning backtrace on|off
30 maint show internal-warning backtrace
31 GDB can now print a backtrace of itself when it encounters either an
32 internal-error, or an internal-warning. This is on by default for
33 internal-error and off by default for internal-warning.
37 ** New function gdb.add_history(), which takes a gdb.Value object
38 and adds the value it represents to GDB's history list. An
39 integer, the index of the new item in the history list, is
42 ** New gdb.events.gdb_exiting event. This event is called with a
43 gdb.GdbExitingEvent object which has the read-only attribute
44 'exit_code', which contains the value of the GDB exit code. This
45 event is triggered once GDB decides it is going to exit, but
46 before GDB starts to clean up its internal state.
48 ** New function gdb.architecture_names(), which returns a list
49 containing all of the possible Architecture.name() values. Each
52 * New features in the GDB remote stub, GDBserver
54 ** GDBserver is now supported on OpenRISC GNU/Linux.
56 * New native configurations
58 GNU/Linux/OpenRISC or1k*-*-linux*
62 * The 'set disassembler-options' command now supports specifying options
65 * GDB now supports general memory tagging functionality if the underlying
66 architecture supports the proper primitives and hooks. Currently this is
67 enabled only for AArch64 MTE.
71 - Additional information when the inferior crashes with a SIGSEGV caused by
72 a memory tag violation.
74 - A new modifier 'm' for the "x" command, which displays allocation tags for a
75 particular memory range.
77 - Display of memory tag mismatches by "print", for addresses and
78 pointers, if memory tagging is supported by the architecture.
80 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
85 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
87 The MI -break-insert and -dprintf-insert commands now support a
88 new "--qualified" option that makes GDB interpret a specified
89 function name as a complete fully-qualified name. This is the
90 equivalent of the CLI's "break -qualified" and "dprintf
93 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
95 The MI -break-insert and -dprintf-insert commands now support a
96 '--force-condition' flag to forcibly define a condition even when
97 the condition is invalid at all locations of the breakpoint. This
98 is equivalent to the '-force-condition' flag of the CLI's "break"
101 ** '-break-condition --force'
103 The MI -break-condition command now supports a '--force' flag to
104 forcibly define a condition even when the condition is invalid at
105 all locations of the selected breakpoint. This is equivalent to
106 the '-force' flag of the CLI's "cond" command.
108 ** '-file-list-exec-source-files [--group-by-objfile]
109 [--basename | --dirname]
112 The existing -file-list-exec-source-files command now takes an
113 optional REGEXP which is used to filter the source files that are
114 included in the results.
116 By default REGEXP is matched against the full filename of the
117 source file. When one of --basename or --dirname is given then
118 REGEXP is only matched against the specified part of the full
121 When the optional --group-by-objfile flag is used the output
122 format is changed, the results are now a list of object files
123 (executable and libraries) with the source files that are
124 associated with each object file.
126 The results from -file-list-exec-source-files now include a
127 'debug-fully-read' field which takes the value 'true' or 'false'.
128 A 'true' value indicates the source file is from a compilation
129 unit that has had its debug information fully read in by GDB, a
130 value of 'false' indicates GDB has only performed a partial scan
131 of the debug information so far.
133 * GDB now supports core file debugging for x86_64 Cygwin programs.
135 * GDB will now look for the .gdbinit file in a config directory before
136 looking for ~/.gdbinit. The file is searched for in the following
137 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
138 $HOME/.gdbinit. On Apple hosts the search order is instead:
139 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
141 * GDB now supports fixed point types which are described in DWARF
142 as base types with a fixed-point encoding. Additionally, support
143 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
146 For Ada, this allows support for fixed point types without requiring
147 the use of the GNAT encoding (based on information added to the type's
148 name following a GNAT-specific format).
150 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
151 or ~/.gdbearlyinit if these files are present. These files are
152 processed earlier than any of the other initialization files and
153 can affect parts of GDB's startup that previously had already been
154 completed before the initialization files were read, for example
155 styling of the initial GDB greeting.
157 * GDB now has two new options "--early-init-command" and
158 "--early-init-eval-command" with corresponding short options "-eix"
159 and "-eiex" that allow options (that would normally appear in a
160 gdbearlyinit file) to be passed on the command line.
162 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
163 now understood by GDB, and can be used to describe the vector
164 registers of a target. The precise requirements of this register
165 feature are documented in the GDB manual.
167 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
168 supported by GDB and describes a new VPR register from the ARM MVE
169 (Helium) extension. See the GDB manual for more information.
173 ** TUI windows now support mouse actions. The mouse wheel scrolls
174 the appropriate window.
176 ** Key combinations that do not have a specific action on the
177 focused window are passed to GDB. For example, you now can use
178 Ctrl-Left/Ctrl-Right to move between words in the command window
179 regardless of which window is in focus. Previously you would
180 need to focus on the command window for such key combinations to
186 show debug event-loop
187 Control the display of debug output about GDB's event loop.
189 set print memory-tag-violations
190 show print memory-tag-violations
191 Control whether to display additional information about memory tag violations
192 when printing pointers and addresses. Architecture support for memory
193 tagging is required for this option to have an effect.
195 maintenance flush symbol-cache
196 maintenance flush register-cache
197 These new commands are equivalent to the already existing commands
198 'maintenance flush-symbol-cache' and 'flushregs' respectively.
200 maintenance flush dcache
201 A new command to flush the dcache.
203 maintenance info target-sections
204 Print GDB's internal target sections table.
207 Print the JIT code objects in the inferior known to GDB.
209 memory-tag show-logical-tag POINTER
210 Print the logical tag for POINTER.
211 memory-tag with-logical-tag POINTER TAG
212 Print POINTER with logical tag TAG.
213 memory-tag show-allocation-tag ADDRESS
214 Print the allocation tag for ADDRESS.
215 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
216 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
217 memory-tag check POINTER
218 Validate that POINTER's logical tag matches the allocation tag.
220 set startup-quietly on|off
222 When 'on', this causes GDB to act as if "-silent" were passed on the
223 command line. This command needs to be added to an early
224 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
227 set print type hex on|off
229 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
230 and offsets of struct members. When 'off', decimal notation is used.
232 set python ignore-environment on|off
233 show python ignore-environment
234 When 'on', this causes GDB's builtin Python to ignore any
235 environment variables that would otherwise affect how Python
236 behaves. This command needs to be added to an early initialization
237 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
239 set python dont-write-bytecode auto|on|off
240 show python dont-write-bytecode
241 When 'on', this causes GDB's builtin Python to not write any
242 byte-code (.pyc files) to disk. This command needs to be added to
243 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
244 order to affect GDB. When 'off' byte-code will always be written.
245 When set to 'auto' (the default) Python will check the
246 PYTHONDONTWRITEBYTECODE environment variable.
250 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
251 [-force-condition] [if CONDITION]
252 This command would previously refuse setting a breakpoint if the
253 CONDITION expression is invalid at a location. It now accepts and
254 defines the breakpoint if there is at least one location at which
255 the CONDITION is valid. The locations for which the CONDITION is
256 invalid, are automatically disabled. If CONDITION is invalid at all
257 of the locations, setting the breakpoint is still rejected. However,
258 the '-force-condition' flag can be used in this case for forcing GDB to
259 define the breakpoint, making all the current locations automatically
260 disabled. This may be useful if the user knows the condition will
261 become meaningful at a future location, e.g. due to a shared library
264 condition [-force] N COND
265 The behavior of this command is changed the same way for the 'break'
266 command as explained above. The '-force' flag can be used to force
267 GDB into defining the condition even when COND is invalid for all the
268 current locations of breakpoint N.
271 maintenance flush-symbol-cache
272 These commands are deprecated in favor of the new commands
273 'maintenance flush register-cache' and 'maintenance flush
274 symbol-cache' respectively.
276 set style version foreground COLOR
277 set style version background COLOR
278 set style version intensity VALUE
279 Control the styling of GDB's version number text.
282 When the ID parameter is omitted, then this command prints information
283 about the current inferior. When the ID parameter is present, the
284 behavior of the command is unchanged and have the inferior ID become
285 the current inferior.
287 maintenance info sections
288 The ALLOBJ keyword has been replaced with an -all-objects command
289 line flag. It is now possible to filter which sections are printed
290 even when -all-objects is passed.
292 ptype[/FLAGS] TYPE | EXPRESSION
293 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
294 notation is used when printing sizes and offsets of struct members.
295 When '/d' is set, decimal notation is used when printing sizes and
296 offsets of struct members. Default behavior is given by 'show print
300 The info sources command output has been restructured. The results
301 are now based around a list of objfiles (executable and libraries),
302 and for each objfile the source files that are part of that objfile
305 * Removed targets and native configurations
307 ARM Symbian arm*-*-symbianelf*
312 Request the remote to send allocation tags for a particular memory range.
314 Request the remote to store the specified allocation tags to the requested
319 ** Improved support for rvalue reference values:
320 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
321 value-referenced-value procedure now handles rvalue reference
324 ** New procedures for obtaining value variants:
325 value-reference-value, value-rvalue-reference-value and
328 ** Temporary breakpoints can now be created with make-breakpoint and
329 tested for using breakpoint-temporary?.
333 ** Inferior objects now contain a read-only 'connection_num' attribute that
334 gives the connection number as seen in 'info connections' and
337 ** New method gdb.Frame.level() which returns the stack level of the
340 ** New method gdb.PendingFrame.level() which returns the stack level
343 ** When hitting a catchpoint, the Python API will now emit a
344 gdb.BreakpointEvent rather than a gdb.StopEvent. The
345 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
347 ** Python TUI windows can now receive mouse click events. If the
348 Window object implements the click method, it is called for each
349 mouse click event in this window.
351 *** Changes in GDB 10
353 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
354 and "org.gnu.gdb.arc.aux". The old names are still supported but
355 must be considered obsolete. They will be deprecated after some
358 * Help and apropos commands will now show the documentation of a
359 command only once, even if that command has one or more aliases.
360 These commands now show the command name, then all of its aliases,
361 and finally the description of the command.
363 * 'help aliases' now shows only the user defined aliases. GDB predefined
364 aliases are shown together with their aliased command.
366 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
367 debugging information as well as source code.
369 When built with debuginfod, GDB can automatically query debuginfod
370 servers for the separate debug files and source code of the executable
373 To build GDB with debuginfod, pass --with-debuginfod to configure (this
374 requires libdebuginfod, the debuginfod client library).
376 debuginfod is distributed with elfutils, starting with version 0.178.
378 You can get the latest version from https://sourceware.org/elfutils.
380 * Multi-target debugging support
382 GDB now supports debugging multiple target connections
383 simultaneously. For example, you can now have each inferior
384 connected to different remote servers running in different machines,
385 or have one inferior debugging a local native process, an inferior
386 debugging a core dump, etc.
388 This support is experimental and comes with some limitations -- you
389 can only resume multiple targets simultaneously if all targets
390 support non-stop mode, and all remote stubs or servers must support
391 the same set of remote protocol features exactly. See also "info
392 connections" and "add-inferior -no-connection" below, and "maint set
393 target-non-stop" in the user manual.
395 * New features in the GDB remote stub, GDBserver
397 ** GDBserver is now supported on ARC GNU/Linux.
399 ** GDBserver is now supported on RISC-V GNU/Linux.
401 ** GDBserver no longer supports these host triplets:
412 i[34567]86-*-mingw32ce*
414 * Debugging MS-Windows processes now sets $_exitsignal when the
415 inferior is terminated by a signal, instead of setting $_exitcode.
417 * Multithreaded symbol loading has now been enabled by default on systems
418 that support it (see entry for GDB 9, below), providing faster
419 performance for programs with many symbols.
421 * The $_siginfo convenience variable now also works on Windows targets,
422 and will display the EXCEPTION_RECORD of the last handled exception.
424 * TUI windows can now be arranged horizontally.
426 * The command history filename can now be set to the empty string
427 either using 'set history filename' or by setting 'GDBHISTFILE=' in
428 the environment. The effect of setting this filename to the empty
429 string is that GDB will not try to load any previous command
432 * On Windows targets, it is now possible to debug 32-bit programs with a
437 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
438 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
439 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
440 running process, this new option indicates whether to detect
441 a mismatch between the current executable file loaded by GDB and the
442 executable file used to start the process. If 'ask', the default,
443 display a warning and ask the user whether to load the process
444 executable file; if 'warn', just display a warning; if 'off', don't
445 attempt to detect a mismatch.
447 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
448 Define a new TUI layout, specifying its name and the windows that
451 maintenance print xml-tdesc [FILE]
452 Prints the current target description as an XML document. If the
453 optional FILE is provided (which is an XML target description) then
454 the target description is read from FILE into GDB, and then
457 maintenance print core-file-backed-mappings
458 Prints file-backed mappings loaded from a core file's note section.
459 Output is expected to be similar to that of "info proc mappings".
461 set debug fortran-array-slicing on|off
462 show debug fortran-array-slicing
463 Print debugging when taking slices of Fortran arrays.
465 set fortran repack-array-slices on|off
466 show fortran repack-array-slices
467 When taking slices from Fortran arrays and strings, if the slice is
468 non-contiguous within the original value then, when this option is
469 on, the new value will be repacked into a single contiguous value.
470 When this option is off, then the value returned will consist of a
471 descriptor that describes the slice within the memory of the
472 original parent value.
476 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
477 The alias command can now specify default args for an alias.
478 GDB automatically prepends the alias default args to the argument list
479 provided explicitly by the user.
480 For example, to have a backtrace with full details, you can define
482 'alias bt_ALL = backtrace -entry-values both -frame-arg all
483 -past-main -past-entry -full'.
484 Alias default arguments can also use a set of nested 'with' commands,
485 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
486 defines the alias pp10 that will pretty print a maximum of 10 elements
487 of the given expression (if the expression is an array).
491 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
497 ** gdb.register_window_type can be used to implement new TUI windows
500 ** Dynamic types can now be queried. gdb.Type has a new attribute,
501 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
502 field of a dynamic type may have None for its "bitpos" attribute
505 ** Commands written in Python can be in the "TUI" help class by
506 registering with the new constant gdb.COMMAND_TUI.
508 ** New method gdb.PendingFrame.architecture () to retrieve the
509 architecture of the pending frame.
511 ** New gdb.Architecture.registers method that returns a
512 gdb.RegisterDescriptorIterator object, an iterator that returns
513 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
514 way to query the registers available for an architecture.
516 ** New gdb.Architecture.register_groups method that returns a
517 gdb.RegisterGroupIterator object, an iterator that returns
518 gdb.RegisterGroup objects. The new RegisterGroup is a way to
519 discover the available register groups.
523 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
525 ** Procedures 'memory-port-read-buffer-size',
526 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
527 and 'set-memory-port-write-buffer-size!' are deprecated. When
528 using Guile 2.2 and later, users who need to control the size of
529 a memory port's internal buffer can use the 'setvbuf' procedure.
533 * 'thread-exited' event is now available in the annotations interface.
535 * New built-in convenience variables $_gdb_major and $_gdb_minor
536 provide the GDB version. They are handy for conditionally using
537 features available only in or since specific GDB versions, in
538 scripts that should work error-free with many different versions,
539 such as in system-wide init files.
541 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
542 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
543 of the GDB settings and the GDB maintenance settings. They are handy
544 for changing the logic of user defined commands depending on the
545 current GDB settings.
547 * GDB now supports Thread Local Storage (TLS) variables on several
548 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
549 architectures require kernel changes. TLS is not yet supported for
550 amd64 and i386 process core dumps.
552 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
553 addresses that required unmasking are shown in the backtrace with the
556 * Two new convenience functions $_cimag and $_creal that extract the
557 imaginary and real parts respectively from complex numbers.
559 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
560 provide the exitcode or exit status of the shell commands launched by
561 GDB commands such as "shell", "pipe" and "make".
563 * The command define-prefix can now define user defined prefix commands.
564 User defined commands can now be defined using these user defined prefix
567 * Command names can now use the . character.
569 * The RX port now supports XML target descriptions.
571 * GDB now shows the Ada task names at more places, e.g. in task switching
574 * GDB can now be compiled with Python 3 on Windows.
576 * New convenience variable $_ada_exception holds the address of the
577 Ada exception being thrown. This is set by Ada-related catchpoints.
579 * GDB can now place breakpoints on nested functions and subroutines in
580 Fortran code. The '::' operator can be used between parent and
581 child scopes when placing breakpoints, for example:
583 (gdb) break outer_function::inner_function
585 The 'outer_function::' prefix is only needed if 'inner_function' is
586 not visible in the current scope.
588 * In addition to the system-wide gdbinit file, if configured with
589 --with-system-gdbinit-dir, GDB will now also load files in that directory
590 as system gdbinit files, unless the -nx or -n flag is provided. Files
591 with extensions .gdb, .py and .scm are supported as long as GDB was
592 compiled with support for that language.
594 * GDB now supports multithreaded symbol loading for higher performance.
595 This feature is still in testing, so it is disabled by default. You
596 can turn it on using 'maint set worker-threads unlimited'.
600 ** The gdb.Value type has a new method 'format_string' which returns a
601 string representing the value. The formatting is controlled by the
602 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
603 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
604 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
606 ** gdb.Type has a new property 'objfile' which returns the objfile the
609 ** The frame information printed by the python frame filtering code
610 is now consistent with what the 'backtrace' command prints when
611 there are no filters, or when the 'backtrace' '-no-filters' option
614 ** The new function gdb.lookup_static_symbol can be used to look up
615 symbols with static linkage.
617 ** The new function gdb.lookup_static_symbols can be used to look up
618 all static symbols with static linkage.
620 ** gdb.Objfile has new methods 'lookup_global_symbol' and
621 'lookup_static_symbol' to lookup a symbol from this objfile only.
623 ** gdb.Block now supports the dictionary syntax for accessing symbols in
624 this block (e.g. block['local_variable']).
628 | [COMMAND] | SHELL_COMMAND
629 | -d DELIM COMMAND DELIM SHELL_COMMAND
630 pipe [COMMAND] | SHELL_COMMAND
631 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
632 Executes COMMAND and sends its output to SHELL_COMMAND.
633 With no COMMAND, repeat the last executed command
634 and send its output to SHELL_COMMAND.
636 define-prefix COMMAND
637 Define or mark a command as a user-defined prefix command.
639 with SETTING [VALUE] [-- COMMAND]
640 w SETTING [VALUE] [-- COMMAND]
641 Temporarily set SETTING, run COMMAND, and restore SETTING.
642 Usage: with SETTING -- COMMAND
643 With no COMMAND, repeats the last executed command.
644 SETTING is any GDB setting you can change with the "set"
645 subcommands. For example, 'with language c -- print someobj'
646 temporarily switches to the C language in order to print someobj.
647 Settings can be combined: 'w lang c -- w print elements unlimited --
648 usercmd' switches to the C language and runs usercmd with no limit
649 of array elements to print.
651 maint with SETTING [VALUE] [-- COMMAND]
652 Like "with", but works with "maintenance set" settings.
654 set may-call-functions [on|off]
655 show may-call-functions
656 This controls whether GDB will attempt to call functions in
657 the program, such as with expressions in the print command. It
658 defaults to on. Calling functions in the program being debugged
659 can have undesired side effects. It is now possible to forbid
660 such function calls. If function calls are forbidden, GDB will throw
661 an error when a command (such as print expression) calls a function
664 set print finish [on|off]
666 This controls whether the `finish' command will display the value
667 that is returned by the current function. When `off', the value is
668 still entered into the value history, but it is not printed. The
673 Allows deeply nested structures to be simplified when printing by
674 replacing deeply nested parts (beyond the max-depth) with ellipses.
675 The default max-depth is 20, but this can be set to unlimited to get
676 the old behavior back.
678 set print raw-values [on|off]
679 show print raw-values
680 By default, GDB applies the enabled pretty printers when printing a
681 value. This allows to ignore the enabled pretty printers for a series
682 of commands. The default is 'off'.
684 set logging debugredirect [on|off]
685 By default, GDB debug output will go to both the terminal and the logfile.
686 Set if you want debug output to go only to the log file.
688 set style title foreground COLOR
689 set style title background COLOR
690 set style title intensity VALUE
691 Control the styling of titles.
693 set style highlight foreground COLOR
694 set style highlight background COLOR
695 set style highlight intensity VALUE
696 Control the styling of highlightings.
698 maint set worker-threads
699 maint show worker-threads
700 Control the number of worker threads that can be used by GDB. The
701 default is 0. "unlimited" lets GDB choose a number that is
702 reasonable. Currently worker threads are only used when demangling
703 the names of linker symbols.
705 set style tui-border foreground COLOR
706 set style tui-border background COLOR
707 Control the styling of TUI borders.
709 set style tui-active-border foreground COLOR
710 set style tui-active-border background COLOR
711 Control the styling of the active TUI border.
713 maint set test-settings KIND
714 maint show test-settings KIND
715 A set of commands used by the testsuite for exercising the settings
718 maint set tui-resize-message [on|off]
719 maint show tui-resize-message
720 Control whether GDB prints a message each time the terminal is
721 resized when in TUI mode. This is primarily useful for testing the
724 set print frame-info [short-location|location|location-and-address
725 |source-and-location|source-line|auto]
726 show print frame-info
727 This controls what frame information is printed by the commands printing
728 a frame. This setting will e.g. influence the behaviour of 'backtrace',
729 'frame', 'stepi'. The python frame filtering also respect this setting.
730 The 'backtrace' '-frame-info' option can override this global setting.
732 set tui compact-source
733 show tui compact-source
735 Enable the "compact" display mode for the TUI source window. The
736 compact display uses only as much space as is needed for the line
737 numbers in the current file, and only a single space to separate the
738 line numbers from the source.
740 info modules [-q] [REGEXP]
741 Return a list of Fortran modules matching REGEXP, or all modules if
744 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
745 Return a list of functions within all modules, grouped by module.
746 The list of functions can be restricted with the optional regular
747 expressions. MODULE_REGEXP matches against the module name,
748 TYPE_REGEXP matches against the function type signature, and REGEXP
749 matches against the function name.
751 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
752 Return a list of variables within all modules, grouped by module.
753 The list of variables can be restricted with the optional regular
754 expressions. MODULE_REGEXP matches against the module name,
755 TYPE_REGEXP matches against the variable type, and REGEXP matches
756 against the variable name.
758 set debug remote-packet-max-chars
759 show debug remote-packet-max-chars
760 Controls the number of characters to output in a remote packet when using
762 The default is 512 bytes.
765 Lists the target connections currently in use.
770 The "help" command uses the title style to enhance the
771 readibility of its output by styling the classes and
775 Similarly to "help", the "apropos" command also uses the
776 title style for the command names. "apropos" accepts now
777 a flag "-v" (verbose) to show the full documentation
778 of matching commands and to use the highlight style to mark
779 the documentation parts matching REGEXP.
783 The GDB printf and eval commands can now print C-style and Ada-style
784 string convenience variables without calling functions in the program.
785 This allows to do formatted printing of strings without having
786 a running inferior, or when debugging a core dump.
788 info sources [-dirname | -basename] [--] [REGEXP]
789 This command has now optional arguments to only print the files
790 whose names match REGEXP. The arguments -dirname and -basename
791 allow to restrict matching respectively to the dirname and basename
795 The "show style" and its subcommands are now styling
796 a style name in their output using its own style, to help
797 the user visualize the different styles.
799 set print frame-arguments
800 The new value 'presence' indicates to only indicate the presence of
801 arguments using ..., instead of printing argument names and values.
803 set print raw-frame-arguments
804 show print raw-frame-arguments
806 These commands replace the similarly-named "set/show print raw
807 frame-arguments" commands (now with a dash instead of a space). The
808 old commands are now deprecated and may be removed in a future
811 add-inferior [-no-connection]
812 The add-inferior command now supports a "-no-connection" flag that
813 makes the new inferior start with no target connection associated.
814 By default, the new inferior inherits the target connection of the
815 current inferior. See also "info connections".
818 This command's output now includes a new "Connection" column
819 indicating which target connection an inferior is bound to. See
820 "info connections" above.
822 maint test-options require-delimiter
823 maint test-options unknown-is-error
824 maint test-options unknown-is-operand
825 maint show test-options-completion-result
826 Commands used by the testsuite to validate the command options
829 focus, winheight, +, -, >, <
830 These commands are now case-sensitive.
832 * New command options, command completion
834 GDB now has a standard infrastructure to support dash-style command
835 options ('-OPT'). One benefit is that commands that use it can
836 easily support completion of command line arguments. Try "CMD
837 -[TAB]" or "help CMD" to find options supported by a command. Over
838 time, we intend to migrate most commands to this infrastructure. A
839 number of commands got support for new command options in this
842 ** The "print" and "compile print" commands now support a number of
843 options that allow overriding relevant global print settings as
844 set by "set print" subcommands:
848 -array-indexes [on|off]
849 -elements NUMBER|unlimited
854 -repeats NUMBER|unlimited
855 -static-members [on|off]
860 Note that because the "print"/"compile print" commands accept
861 arbitrary expressions which may look like options (including
862 abbreviations), if you specify any command option, then you must
863 use a double dash ("--") to mark the end of argument processing.
865 ** The "backtrace" command now supports a number of options that
866 allow overriding relevant global print settings as set by "set
867 backtrace" and "set print" subcommands:
869 -entry-values no|only|preferred|if-needed|both|compact|default
870 -frame-arguments all|scalars|none
871 -raw-frame-arguments [on|off]
872 -frame-info auto|source-line|location|source-and-location
873 |location-and-address|short-location
877 In addition, the full/no-filters/hide qualifiers are now also
878 exposed as command options too:
884 ** The "frame apply", "tfaas" and "faas" commands similarly now
885 support the following options:
890 ** The new "info sources" options -dirname and -basename options
891 are using the standard '-OPT' infrastructure.
893 All options above can also be abbreviated. The argument of boolean
894 (on/off) options can be 0/1 too, and also the argument is assumed
895 "on" if omitted. This allows writing compact command invocations,
898 (gdb) p -ra -p -o 0 -- *myptr
900 The above is equivalent to:
902 (gdb) print -raw-values -pretty -object off -- *myptr
904 ** The "info types" command now supports the '-q' flag to disable
905 printing of some header information in a similar fashion to "info
906 variables" and "info functions".
908 ** The "info variables", "info functions", and "whereis" commands
909 now take a '-n' flag that excludes non-debug symbols (symbols
910 from the symbol table, not from the debug info such as DWARF)
913 * Completion improvements
915 ** GDB can now complete the options of the "thread apply all" and
916 "taas" commands, and their "-ascending" option can now be
919 ** GDB can now complete the options of the "info threads", "info
920 functions", "info variables", "info locals", and "info args"
923 ** GDB can now complete the options of the "compile file" and
924 "compile code" commands. The "compile file" command now
925 completes on filenames.
927 ** GDB can now complete the backtrace command's
928 "full/no-filters/hide" qualifiers.
930 * In settings, you can now abbreviate "unlimited".
932 E.g., "set print elements u" is now equivalent to "set print
938 This lists all the possible completions for the rest of the line, if it
939 were to be given as a command itself. This is intended for use by MI
940 frontends in cases when separate CLI and MI channels cannot be used.
942 -catch-throw, -catch-rethrow, and -catch-catch
943 These can be used to catch C++ exceptions in a similar fashion to
944 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
946 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
947 These commands are the MI equivalent of the CLI commands 'info
948 functions', 'info types', and 'info variables' respectively.
950 -symbol-info-modules, this is the MI equivalent of the CLI 'info
953 -symbol-info-module-functions and -symbol-info-module-variables.
954 These commands are the MI equivalent of the CLI commands 'info
955 module functions' and 'info module variables'.
959 ** The default version of the MI interpreter is now 3 (-i=mi3).
961 ** The output of information about multi-location breakpoints (which is
962 syntactically incorrect in MI 2) has changed in MI 3. This affects
963 the following commands and events:
967 - =breakpoint-created
968 - =breakpoint-modified
970 The -fix-multi-location-breakpoint-output command can be used to enable
971 this behavior with previous MI versions.
973 ** Backtraces and frames include a new optional field addr_flags which is
974 given after the addr field. On AArch64 this contains PAC if the address
975 has been masked in the frame. On all other targets the field is not
980 The testsuite now creates the files gdb.cmd (containing the arguments
981 used to launch GDB) and gdb.in (containing all the commands sent to
982 GDB) in the output directory for each test script. Multiple invocations
983 are appended with .1, .2, .3 etc.
985 * Building GDB and GDBserver now requires GNU make >= 3.82.
987 Using another implementation of the make program or an earlier version of
988 GNU make to build GDB or GDBserver is not supported.
990 * Building GDB now requires GNU readline >= 7.0.
992 GDB now bundles GNU readline 8.0, but if you choose to use
993 --with-system-readline, only readline >= 7.0 can be used.
995 * The TUI SingleKey keymap is now named "SingleKey". This can be used
996 from .inputrc to bind keys in this keymap. This feature is only
997 available when gdb is built against GNU readline 8.0 or later.
999 * Removed targets and native configurations
1001 GDB no longer supports debugging the Cell Broadband Engine. This includes
1002 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1003 of Cell/B.E. applications that use both the PPU and SPU architectures.
1009 * Removed targets and native configurations
1011 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1012 sparc*-*-solaris2.10
1014 *** Changes in GDB 8.3
1016 * GDB and GDBserver now support access to additional registers on
1017 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1020 * GDB now has experimental support for the compilation and injection of
1021 C++ source code into the inferior. This beta release does not include
1022 support for several language features, such as templates, constructors,
1025 This feature requires GCC 7.1 or higher built with libcp1.so
1028 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1029 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1030 'ADDRESS:PORT' method.
1032 * DWARF index cache: GDB can now automatically save indices of DWARF
1033 symbols on disk to speed up further loading of the same binaries.
1035 * Ada task switching is now supported on aarch64-elf targets when
1036 debugging a program using the Ravenscar Profile. For more information,
1037 see the "Tasking Support when using the Ravenscar Profile" section
1038 in the GDB user manual.
1040 * GDB in batch mode now exits with status 1 if the last command to be
1043 * The RISC-V target now supports target descriptions.
1045 * System call catchpoints now support system call aliases on FreeBSD.
1046 When the ABI of a system call changes in FreeBSD, this is
1047 implemented by leaving a compatibility system call using the old ABI
1048 at the existing number and allocating a new system call number for
1049 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1050 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1051 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1052 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1053 so that a system call catchpoint for the 'kevent' system call will
1054 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1055 binaries. This ensures that 'kevent' system calls are caught for
1056 binaries using either the old or new ABIs.
1058 * Terminal styling is now available for the CLI and the TUI. GNU
1059 Source Highlight can additionally be used to provide styling of
1060 source code snippets. See the "set style" commands, below, for more
1063 * Removed support for old demangling styles arm, edg, gnu, hp and
1068 set debug compile-cplus-types
1069 show debug compile-cplus-types
1070 Control the display of debug output about type conversion in the
1071 C++ compile feature. Commands have no effect while compiling
1072 for other languages.
1076 Control whether debug output about files/functions skipping is
1079 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1080 Apply a command to some frames.
1081 FLAG arguments allow to control what output to produce and how to handle
1082 errors raised when applying COMMAND to a frame.
1085 Apply a command to all threads (ignoring errors and empty output).
1086 Shortcut for 'thread apply all -s COMMAND'.
1089 Apply a command to all frames (ignoring errors and empty output).
1090 Shortcut for 'frame apply all -s COMMAND'.
1093 Apply a command to all frames of all threads (ignoring errors and empty
1095 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1097 maint set dwarf unwinders (on|off)
1098 maint show dwarf unwinders
1099 Control whether DWARF unwinders can be used.
1102 Display a list of open files for a process.
1106 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1107 These commands all now take a frame specification which
1108 is either a frame level, or one of the keywords 'level', 'address',
1109 'function', or 'view' followed by a parameter. Selecting a frame by
1110 address, or viewing a frame outside the current backtrace now
1111 requires the use of a keyword. Selecting a frame by level is
1112 unchanged. The MI comment "-stack-select-frame" is unchanged.
1114 target remote FILENAME
1115 target extended-remote FILENAME
1116 If FILENAME is a Unix domain socket, GDB will attempt to connect
1117 to this socket instead of opening FILENAME as a character device.
1119 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1120 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1121 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1122 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1123 These commands can now print only the searched entities
1124 matching the provided regexp(s), giving a condition
1125 on the entity names or entity types. The flag -q disables
1126 printing headers or informations messages.
1132 These commands now determine the syntax for the shown entities
1133 according to the language chosen by `set language'. In particular,
1134 `set language auto' means to automatically choose the language of
1137 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1138 The 'thread apply' command accepts new FLAG arguments.
1139 FLAG arguments allow to control what output to produce and how to handle
1140 errors raised when applying COMMAND to a thread.
1142 set tui tab-width NCHARS
1143 show tui tab-width NCHARS
1144 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1146 set style enabled [on|off]
1148 Enable or disable terminal styling. Styling is enabled by default
1149 on most hosts, but disabled by default when in batch mode.
1151 set style sources [on|off]
1153 Enable or disable source code styling. Source code styling is
1154 enabled by default, but only takes effect if styling in general is
1155 enabled, and if GDB was linked with GNU Source Highlight.
1157 set style filename foreground COLOR
1158 set style filename background COLOR
1159 set style filename intensity VALUE
1160 Control the styling of file names.
1162 set style function foreground COLOR
1163 set style function background COLOR
1164 set style function intensity VALUE
1165 Control the styling of function names.
1167 set style variable foreground COLOR
1168 set style variable background COLOR
1169 set style variable intensity VALUE
1170 Control the styling of variable names.
1172 set style address foreground COLOR
1173 set style address background COLOR
1174 set style address intensity VALUE
1175 Control the styling of addresses.
1179 ** The '-data-disassemble' MI command now accepts an '-a' option to
1180 disassemble the whole function surrounding the given program
1181 counter value or function name. Support for this feature can be
1182 verified by using the "-list-features" command, which should
1183 contain "data-disassemble-a-option".
1185 ** Command responses and notifications that include a frame now include
1186 the frame's architecture in a new "arch" attribute.
1188 * New native configurations
1190 GNU/Linux/RISC-V riscv*-*-linux*
1191 FreeBSD/riscv riscv*-*-freebsd*
1195 GNU/Linux/RISC-V riscv*-*-linux*
1196 CSKY ELF csky*-*-elf
1197 CSKY GNU/LINUX csky*-*-linux
1198 FreeBSD/riscv riscv*-*-freebsd*
1200 GNU/Linux/OpenRISC or1k*-*-linux*
1204 GDB no longer supports native debugging on versions of MS-Windows
1209 ** GDB no longer supports Python versions less than 2.6.
1211 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1212 space associated to that inferior.
1214 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1215 of objfiles associated to that program space.
1217 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1218 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1221 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1222 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1223 correct and did not work properly.
1225 ** The gdb.Value type has a new constructor, which is used to construct a
1226 gdb.Value from a Python buffer object and a gdb.Type.
1232 Enable or disable the undefined behavior sanitizer. This is
1233 disabled by default, but passing --enable-ubsan=yes or
1234 --enable-ubsan=auto to configure will enable it. Enabling this can
1235 cause a performance penalty. The undefined behavior sanitizer was
1236 first introduced in GCC 4.9.
1238 *** Changes in GDB 8.2
1240 * The 'set disassembler-options' command now supports specifying options
1241 for the MIPS target.
1243 * The 'symbol-file' command now accepts an '-o' option to add a relative
1244 offset to all sections.
1246 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1247 a relative offset to all sections, but it allows to override the load
1248 address of individual sections using '-s'.
1250 * The 'add-symbol-file' command no longer requires the second argument
1251 (address of the text section).
1253 * The endianness used with the 'set endian auto' mode in the absence of
1254 an executable selected for debugging is now the last endianness chosen
1255 either by one of the 'set endian big' and 'set endian little' commands
1256 or by inferring from the last executable used, rather than the startup
1259 * The pager now allows a "c" response, meaning to disable the pager
1260 for the rest of the current command.
1262 * The commands 'info variables/functions/types' now show the source line
1263 numbers of symbol definitions when available.
1265 * 'info proc' now works on running processes on FreeBSD systems and core
1266 files created on FreeBSD systems.
1268 * C expressions can now use _Alignof, and C++ expressions can now use
1271 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1272 the vector length while the process is running.
1278 Control display of debugging info regarding the FreeBSD native target.
1280 set|show varsize-limit
1281 This new setting allows the user to control the maximum size of Ada
1282 objects being printed when those objects have a variable type,
1283 instead of that maximum size being hardcoded to 65536 bytes.
1285 set|show record btrace cpu
1286 Controls the processor to be used for enabling errata workarounds for
1287 branch trace decode.
1289 maint check libthread-db
1290 Run integrity checks on the current inferior's thread debugging
1293 maint set check-libthread-db (on|off)
1294 maint show check-libthread-db
1295 Control whether to run integrity checks on inferior specific thread
1296 debugging libraries as they are loaded. The default is not to
1297 perform such checks.
1301 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1303 ** The commands attached to a breakpoint can be set by assigning to
1304 the breakpoint's "commands" field.
1306 ** gdb.execute can now execute multi-line gdb commands.
1308 ** The new functions gdb.convenience_variable and
1309 gdb.set_convenience_variable can be used to get and set the value
1310 of convenience variables.
1312 ** A gdb.Parameter will no longer print the "set" help text on an
1313 ordinary "set"; instead by default a "set" will be silent unless
1314 the get_set_string method returns a non-empty string.
1318 RiscV ELF riscv*-*-elf
1320 * Removed targets and native configurations
1322 m88k running OpenBSD m88*-*-openbsd*
1323 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1324 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1325 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1327 * Aarch64/Linux hardware watchpoints improvements
1329 Hardware watchpoints on unaligned addresses are now properly
1330 supported when running Linux kernel 4.10 or higher: read and access
1331 watchpoints are no longer spuriously missed, and all watchpoints
1332 lengths between 1 and 8 bytes are supported. On older kernels,
1333 watchpoints set on unaligned addresses are no longer missed, with
1334 the tradeoff that there is a possibility of false hits being
1339 --enable-codesign=CERT
1340 This can be used to invoke "codesign -s CERT" after building gdb.
1341 This option is useful on macOS, where code signing is required for
1342 gdb to work properly.
1344 --disable-gdbcli has been removed
1345 This is now silently accepted, but does nothing.
1347 *** Changes in GDB 8.1
1349 * GDB now supports dynamically creating arbitrary register groups specified
1350 in XML target descriptions. This allows for finer grain grouping of
1351 registers on systems with a large amount of registers.
1353 * The 'ptype' command now accepts a '/o' flag, which prints the
1354 offsets and sizes of fields in a struct, like the pahole(1) tool.
1356 * New "--readnever" command line option instructs GDB to not read each
1357 symbol file's symbolic debug information. This makes startup faster
1358 but at the expense of not being able to perform symbolic debugging.
1359 This option is intended for use cases where symbolic debugging will
1360 not be used, e.g., when you only need to dump the debuggee's core.
1362 * GDB now uses the GNU MPFR library, if available, to emulate target
1363 floating-point arithmetic during expression evaluation when the target
1364 uses different floating-point formats than the host. At least version
1365 3.1 of GNU MPFR is required.
1367 * GDB now supports access to the guarded-storage-control registers and the
1368 software-based guarded-storage broadcast control registers on IBM z14.
1370 * On Unix systems, GDB now supports transmitting environment variables
1371 that are to be set or unset to GDBserver. These variables will
1372 affect the environment to be passed to the remote inferior.
1374 To inform GDB of environment variables that are to be transmitted to
1375 GDBserver, use the "set environment" command. Only user set
1376 environment variables are sent to GDBserver.
1378 To inform GDB of environment variables that are to be unset before
1379 the remote inferior is started by the GDBserver, use the "unset
1380 environment" command.
1382 * Completion improvements
1384 ** GDB can now complete function parameters in linespecs and
1385 explicit locations without quoting. When setting breakpoints,
1386 quoting around functions names to help with TAB-completion is
1387 generally no longer necessary. For example, this now completes
1390 (gdb) b function(in[TAB]
1391 (gdb) b function(int)
1393 Related, GDB is no longer confused with completing functions in
1394 C++ anonymous namespaces:
1397 (gdb) b (anonymous namespace)::[TAB][TAB]
1398 (anonymous namespace)::a_function()
1399 (anonymous namespace)::b_function()
1401 ** GDB now has much improved linespec and explicit locations TAB
1402 completion support, that better understands what you're
1403 completing and offers better suggestions. For example, GDB no
1404 longer offers data symbols as possible completions when you're
1405 setting a breakpoint.
1407 ** GDB now TAB-completes label symbol names.
1409 ** The "complete" command now mimics TAB completion accurately.
1411 * New command line options (gcore)
1414 Dump all memory mappings.
1416 * Breakpoints on C++ functions are now set on all scopes by default
1418 By default, breakpoints on functions/methods are now interpreted as
1419 specifying all functions with the given name ignoring missing
1420 leading scopes (namespaces and classes).
1422 For example, assuming a C++ program with symbols named:
1427 both commands "break func()" and "break B::func()" set a breakpoint
1430 You can use the new flag "-qualified" to override this. This makes
1431 GDB interpret the specified function name as a complete
1432 fully-qualified name instead. For example, using the same C++
1433 program, the "break -q B::func" command sets a breakpoint on
1434 "B::func", only. A parameter has been added to the Python
1435 gdb.Breakpoint constructor to achieve the same result when creating
1436 a breakpoint from Python.
1438 * Breakpoints on functions marked with C++ ABI tags
1440 GDB can now set breakpoints on functions marked with C++ ABI tags
1441 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1442 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1444 Functions with a C++11 abi tag are demangled/displayed like this:
1446 function[abi:cxx11](int)
1449 You can now set a breakpoint on such functions simply as if they had
1452 (gdb) b function(int)
1454 Or if you need to disambiguate between tags, like:
1456 (gdb) b function[abi:other_tag](int)
1458 Tab completion was adjusted accordingly as well.
1462 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1463 gdb.new_thread are emitted. See the manual for further
1464 description of these.
1466 ** A new function, "gdb.rbreak" has been added to the Python API.
1467 This function allows the setting of a large number of breakpoints
1468 via a regex pattern in Python. See the manual for further details.
1470 ** Python breakpoints can now accept explicit locations. See the
1471 manual for a further description of this feature.
1474 * New features in the GDB remote stub, GDBserver
1476 ** GDBserver is now able to start inferior processes with a
1477 specified initial working directory.
1479 The user can set the desired working directory to be used from
1480 GDB using the new "set cwd" command.
1482 ** New "--selftest" command line option runs some GDBserver self
1483 tests. These self tests are disabled in releases.
1485 ** On Unix systems, GDBserver now does globbing expansion and variable
1486 substitution in inferior command line arguments.
1488 This is done by starting inferiors using a shell, like GDB does.
1489 See "set startup-with-shell" in the user manual for how to disable
1490 this from GDB when using "target extended-remote". When using
1491 "target remote", you can disable the startup with shell by using the
1492 new "--no-startup-with-shell" GDBserver command line option.
1494 ** On Unix systems, GDBserver now supports receiving environment
1495 variables that are to be set or unset from GDB. These variables
1496 will affect the environment to be passed to the inferior.
1498 * When catching an Ada exception raised with a message, GDB now prints
1499 the message in the catchpoint hit notification. In GDB/MI mode, that
1500 information is provided as an extra field named "exception-message"
1501 in the *stopped notification.
1503 * Trait objects can now be inspected When debugging Rust code. This
1504 requires compiler support which will appear in Rust 1.24.
1506 * New remote packets
1508 QEnvironmentHexEncoded
1509 Inform GDBserver of an environment variable that is to be passed to
1510 the inferior when starting it.
1513 Inform GDBserver of an environment variable that is to be unset
1514 before starting the remote inferior.
1517 Inform GDBserver that the environment should be reset (i.e.,
1518 user-set environment variables should be unset).
1521 Indicates whether the inferior must be started with a shell or not.
1524 Tell GDBserver that the inferior to be started should use a specific
1527 * The "maintenance print c-tdesc" command now takes an optional
1528 argument which is the file name of XML target description.
1530 * The "maintenance selftest" command now takes an optional argument to
1531 filter the tests to be run.
1533 * The "enable", and "disable" commands now accept a range of
1534 breakpoint locations, e.g. "enable 1.3-5".
1539 Set and show the current working directory for the inferior.
1541 set|show compile-gcc
1542 Set and show compilation command used for compiling and injecting code
1543 with the 'compile' commands.
1545 set debug separate-debug-file
1546 show debug separate-debug-file
1547 Control the display of debug output about separate debug file search.
1549 set dump-excluded-mappings
1550 show dump-excluded-mappings
1551 Control whether mappings marked with the VM_DONTDUMP flag should be
1552 dumped when generating a core file.
1554 maint info selftests
1555 List the registered selftests.
1558 Start the debugged program stopping at the first instruction.
1561 Control display of debugging messages related to OpenRISC targets.
1563 set|show print type nested-type-limit
1564 Set and show the limit of nesting level for nested types that the
1565 type printer will show.
1567 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1570 * Safer/improved support for debugging with no debug info
1572 GDB no longer assumes functions with no debug information return
1575 This means that GDB now refuses to call such functions unless you
1576 tell it the function's type, by either casting the call to the
1577 declared return type, or by casting the function to a function
1578 pointer of the right type, and calling that:
1580 (gdb) p getenv ("PATH")
1581 'getenv' has unknown return type; cast the call to its declared return type
1582 (gdb) p (char *) getenv ("PATH")
1583 $1 = 0x7fffffffe "/usr/local/bin:/"...
1584 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1585 $2 = 0x7fffffffe "/usr/local/bin:/"...
1587 Similarly, GDB no longer assumes that global variables with no debug
1588 info have type 'int', and refuses to print the variable's value
1589 unless you tell it the variable's type:
1592 'var' has unknown type; cast it to its declared type
1596 * New native configurations
1598 FreeBSD/aarch64 aarch64*-*-freebsd*
1599 FreeBSD/arm arm*-*-freebsd*
1603 FreeBSD/aarch64 aarch64*-*-freebsd*
1604 FreeBSD/arm arm*-*-freebsd*
1605 OpenRISC ELF or1k*-*-elf
1607 * Removed targets and native configurations
1609 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1611 *** Changes in GDB 8.0
1613 * GDB now supports access to the PKU register on GNU/Linux. The register is
1614 added by the Memory Protection Keys for Userspace feature which will be
1615 available in future Intel CPUs.
1617 * GDB now supports C++11 rvalue references.
1621 ** New functions to start, stop and access a running btrace recording.
1622 ** Rvalue references are now supported in gdb.Type.
1624 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1627 * Building GDB and GDBserver now requires a C++11 compiler.
1629 For example, GCC 4.8 or later.
1631 It is no longer possible to build GDB or GDBserver with a C
1632 compiler. The --disable-build-with-cxx configure option has been
1635 * Building GDB and GDBserver now requires GNU make >= 3.81.
1637 It is no longer supported to build GDB or GDBserver with another
1638 implementation of the make program or an earlier version of GNU make.
1640 * Native debugging on MS-Windows supports command-line redirection
1642 Command-line arguments used for starting programs on MS-Windows can
1643 now include redirection symbols supported by native Windows shells,
1644 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1645 as "run", "start", and "set args", as well as the corresponding MI
1648 * Support for thread names on MS-Windows.
1650 GDB now catches and handles the special exception that programs
1651 running on MS-Windows use to assign names to threads in the
1654 * Support for Java programs compiled with gcj has been removed.
1656 * User commands now accept an unlimited number of arguments.
1657 Previously, only up to 10 was accepted.
1659 * The "eval" command now expands user-defined command arguments.
1661 This makes it easier to process a variable number of arguments:
1666 eval "print $arg%d", $i
1671 * Target descriptions can now describe registers for sparc32 and sparc64.
1673 * GDB now supports DWARF version 5 (debug information format).
1674 Its .debug_names index is not yet supported.
1676 * New native configurations
1678 FreeBSD/mips mips*-*-freebsd
1682 Synopsys ARC arc*-*-elf32
1683 FreeBSD/mips mips*-*-freebsd
1685 * Removed targets and native configurations
1687 Alpha running FreeBSD alpha*-*-freebsd*
1688 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1693 Erases all the flash memory regions reported by the target.
1695 maint print arc arc-instruction address
1696 Print internal disassembler information about instruction at a given address.
1700 set disassembler-options
1701 show disassembler-options
1702 Controls the passing of target specific information to the disassembler.
1703 If it is necessary to specify more than one disassembler option then
1704 multiple options can be placed together into a comma separated list.
1705 The default value is the empty string. Currently, the only supported
1706 targets are ARM, PowerPC and S/390.
1711 Erases all the flash memory regions reported by the target. This is
1712 equivalent to the CLI command flash-erase.
1714 -file-list-shared-libraries
1715 List the shared libraries in the program. This is
1716 equivalent to the CLI command "info shared".
1719 Catchpoints stopping the program when Ada exceptions are
1720 handled. This is equivalent to the CLI command "catch handlers".
1722 *** Changes in GDB 7.12
1724 * GDB and GDBserver now build with a C++ compiler by default.
1726 The --enable-build-with-cxx configure option is now enabled by
1727 default. One must now explicitly configure with
1728 --disable-build-with-cxx in order to build with a C compiler. This
1729 option will be removed in a future release.
1731 * GDBserver now supports recording btrace without maintaining an active
1734 * GDB now supports a negative repeat count in the 'x' command to examine
1735 memory backward from the given address. For example:
1738 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1739 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1740 (gdb) x/-5i 0x0000000000400580
1741 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1742 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1743 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1744 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1745 0x40057b <main(int, char**)+25>:
1746 callq 0x400536 <Func1(int, char const*)>
1748 * Fortran: Support structures with fields of dynamic types and
1749 arrays of dynamic types.
1751 * The symbol dumping maintenance commands have new syntax.
1752 maint print symbols [-pc address] [--] [filename]
1753 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1754 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1755 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1756 maint print msymbols [-objfile objfile] [--] [filename]
1758 * GDB now supports multibit bitfields and enums in target register
1761 * New Python-based convenience function $_as_string(val), which returns
1762 the textual representation of a value. This function is especially
1763 useful to obtain the text label of an enum value.
1765 * Intel MPX bound violation handling.
1767 Segmentation faults caused by a Intel MPX boundary violation
1768 now display the kind of violation (upper or lower), the memory
1769 address accessed and the memory bounds, along with the usual
1770 signal received and code location.
1774 Program received signal SIGSEGV, Segmentation fault
1775 Upper bound violation while accessing address 0x7fffffffc3b3
1776 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1777 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1779 * Rust language support.
1780 GDB now supports debugging programs written in the Rust programming
1781 language. See https://www.rust-lang.org/ for more information about
1784 * Support for running interpreters on specified input/output devices
1786 GDB now supports a new mechanism that allows frontends to provide
1787 fully featured GDB console views, as a better alternative to
1788 building such views on top of the "-interpreter-exec console"
1789 command. See the new "new-ui" command below. With that command,
1790 frontends can now start GDB in the traditional command-line mode
1791 running in an embedded terminal emulator widget, and create a
1792 separate MI interpreter running on a specified i/o device. In this
1793 way, GDB handles line editing, history, tab completion, etc. in the
1794 console all by itself, and the GUI uses the separate MI interpreter
1795 for its own control and synchronization, invisible to the command
1798 * The "catch syscall" command catches groups of related syscalls.
1800 The "catch syscall" command now supports catching a group of related
1801 syscalls using the 'group:' or 'g:' prefix.
1806 skip -gfile file-glob-pattern
1807 skip -function function
1808 skip -rfunction regular-expression
1809 A generalized form of the skip command, with new support for
1810 glob-style file names and regular expressions for function names.
1811 Additionally, a file spec and a function spec may now be combined.
1813 maint info line-table REGEXP
1814 Display the contents of GDB's internal line table data structure.
1817 Run any GDB unit tests that were compiled in.
1820 Start a new user interface instance running INTERP as interpreter,
1821 using the TTY file for input/output.
1825 ** gdb.Breakpoint objects have a new attribute "pending", which
1826 indicates whether the breakpoint is pending.
1827 ** Three new breakpoint-related events have been added:
1828 gdb.breakpoint_created, gdb.breakpoint_modified, and
1829 gdb.breakpoint_deleted.
1831 signal-event EVENTID
1832 Signal ("set") the given MS-Windows event object. This is used in
1833 conjunction with the Windows JIT debugging (AeDebug) support, where
1834 the OS suspends a crashing process until a debugger can attach to
1835 it. Resuming the crashing process, in order to debug it, is done by
1836 signalling an event.
1838 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1839 was added in GDBserver, including JIT compiling fast tracepoint's
1840 conditional expression bytecode into native code.
1842 * Support for various remote target protocols and ROM monitors has
1845 target m32rsdi Remote M32R debugging over SDI
1846 target mips MIPS remote debugging protocol
1847 target pmon PMON ROM monitor
1848 target ddb NEC's DDB variant of PMON for Vr4300
1849 target rockhopper NEC RockHopper variant of PMON
1850 target lsi LSI variant of PMO
1852 * Support for tracepoints and fast tracepoints on powerpc-linux,
1853 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1854 including JIT compiling fast tracepoint's conditional expression
1855 bytecode into native code.
1857 * MI async record =record-started now includes the method and format used for
1858 recording. For example:
1860 =record-started,thread-group="i1",method="btrace",format="bts"
1862 * MI async record =thread-selected now includes the frame field. For example:
1864 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1868 Andes NDS32 nds32*-*-elf
1870 *** Changes in GDB 7.11
1872 * GDB now supports debugging kernel-based threads on FreeBSD.
1874 * Per-inferior thread numbers
1876 Thread numbers are now per inferior instead of global. If you're
1877 debugging multiple inferiors, GDB displays thread IDs using a
1878 qualified INF_NUM.THR_NUM form. For example:
1882 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1883 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1884 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1885 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1887 As consequence, thread numbers as visible in the $_thread
1888 convenience variable and in Python's InferiorThread.num attribute
1889 are no longer unique between inferiors.
1891 GDB now maintains a second thread ID per thread, referred to as the
1892 global thread ID, which is the new equivalent of thread numbers in
1893 previous releases. See also $_gthread below.
1895 For backwards compatibility, MI's thread IDs always refer to global
1898 * Commands that accept thread IDs now accept the qualified
1899 INF_NUM.THR_NUM form as well. For example:
1902 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1905 * In commands that accept a list of thread IDs, you can now refer to
1906 all threads of an inferior using a star wildcard. GDB accepts
1907 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1908 refer to all threads of the current inferior. For example, "info
1911 * You can use "info threads -gid" to display the global thread ID of
1914 * The new convenience variable $_gthread holds the global number of
1917 * The new convenience variable $_inferior holds the number of the
1920 * GDB now displays the ID and name of the thread that hit a breakpoint
1921 or received a signal, if your program is multi-threaded. For
1924 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1925 Thread 1 "main" received signal SIGINT, Interrupt.
1927 * Record btrace now supports non-stop mode.
1929 * Support for tracepoints on aarch64-linux was added in GDBserver.
1931 * The 'record instruction-history' command now indicates speculative execution
1932 when using the Intel Processor Trace recording format.
1934 * GDB now allows users to specify explicit locations, bypassing
1935 the linespec parser. This feature is also available to GDB/MI
1938 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1939 GDB now is able to debug both AArch64 applications and ARM applications
1942 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1943 including JIT compiling fast tracepoint's conditional expression bytecode
1946 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1948 * "info threads", "info inferiors", "info display", "info checkpoints"
1949 and "maint info program-spaces" now list the corresponding items in
1950 ascending ID order, for consistency with all other "info" commands.
1952 * In Ada, the overloads selection menu has been enhanced to display the
1953 parameter types and the return types for the matching overloaded subprograms.
1957 maint set target-non-stop (on|off|auto)
1958 maint show target-non-stop
1959 Control whether GDB targets always operate in non-stop mode even if
1960 "set non-stop" is "off". The default is "auto", meaning non-stop
1961 mode is enabled if supported by the target.
1963 maint set bfd-sharing
1964 maint show bfd-sharing
1965 Control the reuse of bfd objects.
1968 show debug bfd-cache
1969 Control display of debugging info regarding bfd caching.
1973 Control display of debugging info regarding FreeBSD threads.
1975 set remote multiprocess-extensions-packet
1976 show remote multiprocess-extensions-packet
1977 Set/show the use of the remote protocol multiprocess extensions.
1979 set remote thread-events
1980 show remote thread-events
1981 Set/show the use of thread create/exit events.
1983 set ada print-signatures on|off
1984 show ada print-signatures"
1985 Control whether parameter types and return types are displayed in overloads
1986 selection menus. It is activated (@code{on}) by default.
1990 Controls the maximum size of memory, in bytes, that GDB will
1991 allocate for value contents. Prevents incorrect programs from
1992 causing GDB to allocate overly large buffers. Default is 64k.
1994 * The "disassemble" command accepts a new modifier: /s.
1995 It prints mixed source+disassembly like /m with two differences:
1996 - disassembled instructions are now printed in program order, and
1997 - and source for all relevant files is now printed.
1998 The "/m" option is now considered deprecated: its "source-centric"
1999 output hasn't proved useful in practice.
2001 * The "record instruction-history" command accepts a new modifier: /s.
2002 It behaves exactly like /m and prints mixed source+disassembly.
2004 * The "set scheduler-locking" command supports a new mode "replay".
2005 It behaves like "off" in record mode and like "on" in replay mode.
2007 * Support for various ROM monitors has been removed:
2009 target dbug dBUG ROM monitor for Motorola ColdFire
2010 target picobug Motorola picobug monitor
2011 target dink32 DINK32 ROM monitor for PowerPC
2012 target m32r Renesas M32R/D ROM monitor
2013 target mon2000 mon2000 ROM monitor
2014 target ppcbug PPCBUG ROM monitor for PowerPC
2016 * Support for reading/writing memory and extracting values on architectures
2017 whose memory is addressable in units of any integral multiple of 8 bits.
2020 Allows to break when an Ada exception is handled.
2022 * New remote packets
2025 Indicates that an exec system call was executed.
2027 exec-events feature in qSupported
2028 The qSupported packet allows GDB to request support for exec
2029 events using the new 'gdbfeature' exec-event, and the qSupported
2030 response can contain the corresponding 'stubfeature'. Set and
2031 show commands can be used to display whether these features are enabled.
2034 Equivalent to interrupting with the ^C character, but works in
2037 thread created stop reason (T05 create:...)
2038 Indicates that the thread was just created and is stopped at entry.
2040 thread exit stop reply (w exitcode;tid)
2041 Indicates that the thread has terminated.
2044 Enables/disables thread create and exit event reporting. For
2045 example, this is used in non-stop mode when GDB stops a set of
2046 threads and synchronously waits for the their corresponding stop
2047 replies. Without exit events, if one of the threads exits, GDB
2048 would hang forever not knowing that it should no longer expect a
2049 stop for that same thread.
2052 Indicates that there are no resumed threads left in the target (all
2053 threads are stopped). The remote stub reports support for this stop
2054 reply to GDB's qSupported query.
2057 Enables/disables catching syscalls from the inferior process.
2058 The remote stub reports support for this packet to GDB's qSupported query.
2060 syscall_entry stop reason
2061 Indicates that a syscall was just called.
2063 syscall_return stop reason
2064 Indicates that a syscall just returned.
2066 * Extended-remote exec events
2068 ** GDB now has support for exec events on extended-remote Linux targets.
2069 For such targets with Linux kernels 2.5.46 and later, this enables
2070 follow-exec-mode and exec catchpoints.
2072 set remote exec-event-feature-packet
2073 show remote exec-event-feature-packet
2074 Set/show the use of the remote exec event feature.
2076 * Thread names in remote protocol
2078 The reply to qXfer:threads:read may now include a name attribute for each
2081 * Target remote mode fork and exec events
2083 ** GDB now has support for fork and exec events on target remote mode
2084 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2085 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2086 fork and exec catchpoints.
2088 * Remote syscall events
2090 ** GDB now has support for catch syscall on remote Linux targets,
2091 currently enabled on x86/x86_64 architectures.
2093 set remote catch-syscall-packet
2094 show remote catch-syscall-packet
2095 Set/show the use of the remote catch syscall feature.
2099 ** The -var-set-format command now accepts the zero-hexadecimal
2100 format. It outputs data in hexadecimal format with zero-padding on the
2105 ** gdb.InferiorThread objects have a new attribute "global_num",
2106 which refers to the thread's global thread ID. The existing
2107 "num" attribute now refers to the thread's per-inferior number.
2108 See "Per-inferior thread numbers" above.
2109 ** gdb.InferiorThread objects have a new attribute "inferior", which
2110 is the Inferior object the thread belongs to.
2112 *** Changes in GDB 7.10
2114 * Support for process record-replay and reverse debugging on aarch64*-linux*
2115 targets has been added. GDB now supports recording of A64 instruction set
2116 including advance SIMD instructions.
2118 * Support for Sun's version of the "stabs" debug file format has been removed.
2120 * GDB now honors the content of the file /proc/PID/coredump_filter
2121 (PID is the process ID) on GNU/Linux systems. This file can be used
2122 to specify the types of memory mappings that will be included in a
2123 corefile. For more information, please refer to the manual page of
2124 "core(5)". GDB also has a new command: "set use-coredump-filter
2125 on|off". It allows to set whether GDB will read the content of the
2126 /proc/PID/coredump_filter file when generating a corefile.
2128 * The "info os" command on GNU/Linux can now display information on
2130 "info os cpus" Listing of all cpus/cores on the system
2132 * GDB has two new commands: "set serial parity odd|even|none" and
2133 "show serial parity". These allows to set or show parity for the
2136 * The "info source" command now displays the producer string if it was
2137 present in the debug info. This typically includes the compiler version
2138 and may include things like its command line arguments.
2140 * The "info dll", an alias of the "info sharedlibrary" command,
2141 is now available on all platforms.
2143 * Directory names supplied to the "set sysroot" commands may be
2144 prefixed with "target:" to tell GDB to access shared libraries from
2145 the target system, be it local or remote. This replaces the prefix
2146 "remote:". The default sysroot has been changed from "" to
2147 "target:". "remote:" is automatically converted to "target:" for
2148 backward compatibility.
2150 * The system root specified by "set sysroot" will be prepended to the
2151 filename of the main executable (if reported to GDB as absolute by
2152 the operating system) when starting processes remotely, and when
2153 attaching to already-running local or remote processes.
2155 * GDB now supports automatic location and retrieval of executable
2156 files from remote targets. Remote debugging can now be initiated
2157 using only a "target remote" or "target extended-remote" command
2158 (no "set sysroot" or "file" commands are required). See "New remote
2161 * The "dump" command now supports verilog hex format.
2163 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2165 * On GNU/Linux, GDB and gdbserver are now able to access executable
2166 and shared library files without a "set sysroot" command when
2167 attaching to processes running in different mount namespaces from
2168 the debugger. This makes it possible to attach to processes in
2169 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2170 See "New remote packets" below.
2172 * The "tui reg" command now provides completion for all of the
2173 available register groups, including target specific groups.
2175 * The HISTSIZE environment variable is no longer read when determining
2176 the size of GDB's command history. GDB now instead reads the dedicated
2177 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2178 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2183 ** Memory ports can now be unbuffered.
2187 ** gdb.Objfile objects have a new attribute "username",
2188 which is the name of the objfile as specified by the user,
2189 without, for example, resolving symlinks.
2190 ** You can now write frame unwinders in Python.
2191 ** gdb.Type objects have a new method "optimized_out",
2192 returning optimized out gdb.Value instance of this type.
2193 ** gdb.Value objects have new methods "reference_value" and
2194 "const_value" which return a reference to the value and a
2195 "const" version of the value respectively.
2199 maint print symbol-cache
2200 Print the contents of the symbol cache.
2202 maint print symbol-cache-statistics
2203 Print statistics of symbol cache usage.
2205 maint flush-symbol-cache
2206 Flush the contents of the symbol cache.
2210 Start branch trace recording using Branch Trace Store (BTS) format.
2213 Evaluate expression by using the compiler and print result.
2217 Explicit commands for enabling and disabling tui mode.
2220 set mpx bound on i386 and amd64
2221 Support for bound table investigation on Intel MPX enabled applications.
2225 Start branch trace recording using Intel Processor Trace format.
2228 Print information about branch tracing internals.
2230 maint btrace packet-history
2231 Print the raw branch tracing data.
2233 maint btrace clear-packet-history
2234 Discard the stored raw branch tracing data.
2237 Discard all branch tracing data. It will be fetched and processed
2238 anew by the next "record" command.
2243 Renamed from "set debug dwarf2-die".
2244 show debug dwarf-die
2245 Renamed from "show debug dwarf2-die".
2247 set debug dwarf-read
2248 Renamed from "set debug dwarf2-read".
2249 show debug dwarf-read
2250 Renamed from "show debug dwarf2-read".
2252 maint set dwarf always-disassemble
2253 Renamed from "maint set dwarf2 always-disassemble".
2254 maint show dwarf always-disassemble
2255 Renamed from "maint show dwarf2 always-disassemble".
2257 maint set dwarf max-cache-age
2258 Renamed from "maint set dwarf2 max-cache-age".
2259 maint show dwarf max-cache-age
2260 Renamed from "maint show dwarf2 max-cache-age".
2262 set debug dwarf-line
2263 show debug dwarf-line
2264 Control display of debugging info regarding DWARF line processing.
2267 show max-completions
2268 Set the maximum number of candidates to be considered during
2269 completion. The default value is 200. This limit allows GDB
2270 to avoid generating large completion lists, the computation of
2271 which can cause the debugger to become temporarily unresponsive.
2273 set history remove-duplicates
2274 show history remove-duplicates
2275 Control the removal of duplicate history entries.
2277 maint set symbol-cache-size
2278 maint show symbol-cache-size
2279 Control the size of the symbol cache.
2281 set|show record btrace bts buffer-size
2282 Set and show the size of the ring buffer used for branch tracing in
2284 The obtained size may differ from the requested size. Use "info
2285 record" to see the obtained buffer size.
2287 set debug linux-namespaces
2288 show debug linux-namespaces
2289 Control display of debugging info regarding Linux namespaces.
2291 set|show record btrace pt buffer-size
2292 Set and show the size of the ring buffer used for branch tracing in
2293 Intel Processor Trace format.
2294 The obtained size may differ from the requested size. Use "info
2295 record" to see the obtained buffer size.
2297 maint set|show btrace pt skip-pad
2298 Set and show whether PAD packets are skipped when computing the
2301 * The command 'thread apply all' can now support new option '-ascending'
2302 to call its specified command for all threads in ascending order.
2304 * Python/Guile scripting
2306 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2307 special section named `.debug_gdb_scripts'.
2309 * New remote packets
2311 qXfer:btrace-conf:read
2312 Return the branch trace configuration for the current thread.
2314 Qbtrace-conf:bts:size
2315 Set the requested ring buffer size for branch tracing in BTS format.
2318 Enable Intel Processor Trace-based branch tracing for the current
2319 process. The remote stub reports support for this packet to GDB's
2322 Qbtrace-conf:pt:size
2323 Set the requested ring buffer size for branch tracing in Intel Processor
2327 Indicates a memory breakpoint instruction was executed, irrespective
2328 of whether it was GDB that planted the breakpoint or the breakpoint
2329 is hardcoded in the program. This is required for correct non-stop
2333 Indicates the target stopped for a hardware breakpoint. This is
2334 required for correct non-stop mode operation.
2337 Return information about files on the remote system.
2339 qXfer:exec-file:read
2340 Return the full absolute name of the file that was executed to
2341 create a process running on the remote system.
2344 Select the filesystem on which vFile: operations with filename
2345 arguments will operate. This is required for GDB to be able to
2346 access files on remote targets where the remote stub does not
2347 share a common filesystem with the inferior(s).
2350 Indicates that a fork system call was executed.
2353 Indicates that a vfork system call was executed.
2355 vforkdone stop reason
2356 Indicates that a vfork child of the specified process has executed
2357 an exec or exit, allowing the vfork parent to resume execution.
2359 fork-events and vfork-events features in qSupported
2360 The qSupported packet allows GDB to request support for fork and
2361 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2362 and the qSupported response can contain the corresponding
2363 'stubfeatures'. Set and show commands can be used to display
2364 whether these features are enabled.
2366 * Extended-remote fork events
2368 ** GDB now has support for fork events on extended-remote Linux
2369 targets. For targets with Linux kernels 2.5.60 and later, this
2370 enables follow-fork-mode and detach-on-fork for both fork and
2371 vfork, as well as fork and vfork catchpoints.
2373 * The info record command now shows the recording format and the
2374 branch tracing configuration for the current thread when using
2375 the btrace record target.
2376 For the BTS format, it shows the ring buffer size.
2378 * GDB now has support for DTrace USDT (Userland Static Defined
2379 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2381 * GDB now supports access to vector registers on S/390 GNU/Linux
2384 * Removed command line options
2386 -xdb HP-UX XDB compatibility mode.
2388 * Removed targets and native configurations
2390 HP/PA running HP-UX hppa*-*-hpux*
2391 Itanium running HP-UX ia64-*-hpux*
2393 * New configure options
2396 This configure option allows the user to build GDB with support for
2397 Intel Processor Trace (default: auto). This requires libipt.
2399 --with-libipt-prefix=PATH
2400 Specify the path to the version of libipt that GDB should use.
2401 $PATH/include should contain the intel-pt.h header and
2402 $PATH/lib should contain the libipt.so library.
2404 *** Changes in GDB 7.9.1
2408 ** Xmethods can now specify a result type.
2410 *** Changes in GDB 7.9
2412 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2416 ** You can now access frame registers from Python scripts.
2417 ** New attribute 'producer' for gdb.Symtab objects.
2418 ** gdb.Objfile objects have a new attribute "progspace",
2419 which is the gdb.Progspace object of the containing program space.
2420 ** gdb.Objfile objects have a new attribute "owner".
2421 ** gdb.Objfile objects have a new attribute "build_id",
2422 which is the build ID generated when the file was built.
2423 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2424 ** A new event "gdb.clear_objfiles" has been added, triggered when
2425 selecting a new file to debug.
2426 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2427 ** New function gdb.lookup_objfile.
2429 New events which are triggered when GDB modifies the state of the
2432 ** gdb.events.inferior_call_pre: Function call is about to be made.
2433 ** gdb.events.inferior_call_post: Function call has just been made.
2434 ** gdb.events.memory_changed: A memory location has been altered.
2435 ** gdb.events.register_changed: A register has been altered.
2437 * New Python-based convenience functions:
2439 ** $_caller_is(name [, number_of_frames])
2440 ** $_caller_matches(regexp [, number_of_frames])
2441 ** $_any_caller_is(name [, number_of_frames])
2442 ** $_any_caller_matches(regexp [, number_of_frames])
2444 * GDB now supports the compilation and injection of source code into
2445 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2446 to compile the source code to object code, and if successful, inject
2447 and execute that code within the current context of the inferior.
2448 Currently the C language is supported. The commands used to
2449 interface with this new feature are:
2451 compile code [-raw|-r] [--] [source code]
2452 compile file [-raw|-r] filename
2456 demangle [-l language] [--] name
2457 Demangle "name" in the specified language, or the current language
2458 if elided. This command is renamed from the "maint demangle" command.
2459 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2460 as "maint demangler-warning".
2462 queue-signal signal-name-or-number
2463 Queue a signal to be delivered to the thread when it is resumed.
2465 add-auto-load-scripts-directory directory
2466 Add entries to the list of directories from which to load auto-loaded
2469 maint print user-registers
2470 List all currently available "user" registers.
2472 compile code [-r|-raw] [--] [source code]
2473 Compile, inject, and execute in the inferior the executable object
2474 code produced by compiling the provided source code.
2476 compile file [-r|-raw] filename
2477 Compile and inject into the inferior the executable object code
2478 produced by compiling the source code stored in the filename
2481 * On resume, GDB now always passes the signal the program had stopped
2482 for to the thread the signal was sent to, even if the user changed
2483 threads before resuming. Previously GDB would often (but not
2484 always) deliver the signal to the thread that happens to be current
2487 * Conversely, the "signal" command now consistently delivers the
2488 requested signal to the current thread. GDB now asks for
2489 confirmation if the program had stopped for a signal and the user
2490 switched threads meanwhile.
2492 * "breakpoint always-inserted" modes "off" and "auto" merged.
2494 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2495 won't remove breakpoints from the target until all threads stop,
2496 even in non-stop mode. The "auto" mode has been removed, and "off"
2497 is now the default mode.
2501 set debug symbol-lookup
2502 show debug symbol-lookup
2503 Control display of debugging info regarding symbol lookup.
2507 ** The -list-thread-groups command outputs an exit-code field for
2508 inferiors that have exited.
2512 MIPS SDE mips*-sde*-elf*
2516 Support for these obsolete configurations has been removed.
2518 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2519 SGI Irix-5.x mips-*-irix5*
2520 SGI Irix-6.x mips-*-irix6*
2521 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2522 VAX running Ultrix vax-*-ultrix*
2524 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2525 and "assf"), have been removed. Use the "sharedlibrary" command, or
2526 its alias "share", instead.
2528 *** Changes in GDB 7.8
2530 * New command line options
2533 This is an alias for the --data-directory option.
2535 * GDB supports printing and modifying of variable length automatic arrays
2536 as specified in ISO C99.
2538 * The ARM simulator now supports instruction level tracing
2539 with or without disassembly.
2543 GDB now has support for scripting using Guile. Whether this is
2544 available is determined at configure time.
2545 Guile version 2.0 or greater is required.
2546 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2548 * New commands (for set/show, see "New options" below)
2552 Invoke CODE by passing it to the Guile interpreter.
2556 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2558 info auto-load guile-scripts [regexp]
2559 Print the list of automatically loaded Guile scripts.
2561 * The source command is now capable of sourcing Guile scripts.
2562 This feature is dependent on the debugger being built with Guile support.
2566 set print symbol-loading (off|brief|full)
2567 show print symbol-loading
2568 Control whether to print informational messages when loading symbol
2569 information for a file. The default is "full", but when debugging
2570 programs with large numbers of shared libraries the amount of output
2571 becomes less useful.
2573 set guile print-stack (none|message|full)
2574 show guile print-stack
2575 Show a stack trace when an error is encountered in a Guile script.
2577 set auto-load guile-scripts (on|off)
2578 show auto-load guile-scripts
2579 Control auto-loading of Guile script files.
2581 maint ada set ignore-descriptive-types (on|off)
2582 maint ada show ignore-descriptive-types
2583 Control whether the debugger should ignore descriptive types in Ada
2584 programs. The default is not to ignore the descriptive types. See
2585 the user manual for more details on descriptive types and the intended
2586 usage of this option.
2588 set auto-connect-native-target
2590 Control whether GDB is allowed to automatically connect to the
2591 native target for the run, attach, etc. commands when not connected
2592 to any target yet. See also "target native" below.
2594 set record btrace replay-memory-access (read-only|read-write)
2595 show record btrace replay-memory-access
2596 Control what memory accesses are allowed during replay.
2598 maint set target-async (on|off)
2599 maint show target-async
2600 This controls whether GDB targets operate in synchronous or
2601 asynchronous mode. Normally the default is asynchronous, if it is
2602 available; but this can be changed to more easily debug problems
2603 occurring only in synchronous mode.
2605 set mi-async (on|off)
2607 Control whether MI asynchronous mode is preferred. This supersedes
2608 "set target-async" of previous GDB versions.
2610 * "set target-async" is deprecated as a CLI option and is now an alias
2611 for "set mi-async" (only puts MI into async mode).
2613 * Background execution commands (e.g., "c&", "s&", etc.) are now
2614 possible ``out of the box'' if the target supports them. Previously
2615 the user would need to explicitly enable the possibility with the
2616 "set target-async on" command.
2618 * New features in the GDB remote stub, GDBserver
2620 ** New option --debug-format=option1[,option2,...] allows one to add
2621 additional text to each output. At present only timestamps
2622 are supported: --debug-format=timestamps.
2623 Timestamps can also be turned on with the
2624 "monitor set debug-format timestamps" command from GDB.
2626 * The 'record instruction-history' command now starts counting instructions
2627 at one. This also affects the instruction ranges reported by the
2628 'record function-call-history' command when given the /i modifier.
2630 * The command 'record function-call-history' supports a new modifier '/c' to
2631 indent the function names based on their call stack depth.
2632 The fields for the '/i' and '/l' modifier have been reordered.
2633 The source line range is now prefixed with 'at'.
2634 The instruction range is now prefixed with 'inst'.
2635 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2636 "record instruction-history" and "list" commands.
2638 * The ranges given as arguments to the 'record function-call-history' and
2639 'record instruction-history' commands are now inclusive.
2641 * The btrace record target now supports the 'record goto' command.
2642 For locations inside the execution trace, the back trace is computed
2643 based on the information stored in the execution trace.
2645 * The btrace record target supports limited reverse execution and replay.
2646 The target does not record data and therefore does not allow reading
2647 memory or registers.
2649 * The "catch syscall" command now works on s390*-linux* targets.
2651 * The "compare-sections" command is no longer specific to target
2652 remote. It now works with all targets.
2654 * All native targets are now consistently called "native".
2655 Consequently, the "target child", "target GNU", "target djgpp",
2656 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2657 commands have been replaced with "target native". The QNX/NTO port
2658 leaves the "procfs" target in place and adds a "native" target for
2659 consistency with other ports. The impact on users should be minimal
2660 as these commands previously either throwed an error, or were
2661 no-ops. The target's name is visible in the output of the following
2662 commands: "help target", "info target", "info files", "maint print
2665 * The "target native" command now connects to the native target. This
2666 can be used to launch native programs even when "set
2667 auto-connect-native-target" is set to off.
2669 * GDB now supports access to Intel MPX registers on GNU/Linux.
2671 * Support for Intel AVX-512 registers on GNU/Linux.
2672 Support displaying and modifying Intel AVX-512 registers
2673 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2675 * New remote packets
2677 qXfer:btrace:read's annex
2678 The qXfer:btrace:read packet supports a new annex 'delta' to read
2679 branch trace incrementally.
2683 ** Valid Python operations on gdb.Value objects representing
2684 structs/classes invoke the corresponding overloaded operators if
2686 ** New `Xmethods' feature in the Python API. Xmethods are
2687 additional methods or replacements for existing methods of a C++
2688 class. This feature is useful for those cases where a method
2689 defined in C++ source code could be inlined or optimized out by
2690 the compiler, making it unavailable to GDB.
2693 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2695 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2696 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2697 its alias "share", instead.
2699 * The commands "set remotebaud" and "show remotebaud" are no longer
2700 supported. Use "set serial baud" and "show serial baud" (respectively)
2705 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2706 target-async". The latter is left as a deprecated alias of the
2707 former for backward compatibility. If the target supports it,
2708 CLI background execution commands are now always possible by
2709 default, independently of whether the frontend stated a
2710 preference for asynchronous execution with "-gdb-set mi-async".
2711 Previously "-gdb-set target-async off" affected both MI execution
2712 commands and CLI execution commands.
2714 *** Changes in GDB 7.7
2716 * Improved support for process record-replay and reverse debugging on
2717 arm*-linux* targets. Support for thumb32 and syscall instruction
2718 recording has been added.
2720 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2722 * GDB now supports Fission DWP file format version 2.
2723 http://gcc.gnu.org/wiki/DebugFission
2725 * New convenience function "$_isvoid", to check whether an expression
2726 is void. A void expression is an expression where the type of the
2727 result is "void". For example, some convenience variables may be
2728 "void" when evaluated (e.g., "$_exitcode" before the execution of
2729 the program being debugged; or an undefined convenience variable).
2730 Another example, when calling a function whose return type is
2733 * The "maintenance print objfiles" command now takes an optional regexp.
2735 * The "catch syscall" command now works on arm*-linux* targets.
2737 * GDB now consistently shows "<not saved>" when printing values of
2738 registers the debug info indicates have not been saved in the frame
2739 and there's nowhere to retrieve them from
2740 (callee-saved/call-clobbered registers):
2745 (gdb) info registers rax
2748 Before, the former would print "<optimized out>", and the latter
2749 "*value not available*".
2751 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2756 ** Frame filters and frame decorators have been added.
2757 ** Temporary breakpoints are now supported.
2758 ** Line tables representation has been added.
2759 ** New attribute 'parent_type' for gdb.Field objects.
2760 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2761 ** New attribute 'name' for gdb.Type objects.
2765 Nios II ELF nios2*-*-elf
2766 Nios II GNU/Linux nios2*-*-linux
2767 Texas Instruments MSP430 msp430*-*-elf
2769 * Removed native configurations
2771 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2772 been removed. ELF variants of these configurations are kept supported.
2774 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2775 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2776 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2777 i[34567]86-*-openbsd3.[0-3]
2778 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2779 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2780 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2784 Like "catch throw", but catches a re-thrown exception.
2785 maint check-psymtabs
2786 Renamed from old "maint check-symtabs".
2788 Perform consistency checks on symtabs.
2789 maint expand-symtabs
2790 Expand symtabs matching an optional regexp.
2793 Display the details of GDB configure-time options.
2795 maint set|show per-command
2796 maint set|show per-command space
2797 maint set|show per-command time
2798 maint set|show per-command symtab
2799 Enable display of per-command gdb resource usage.
2801 remove-symbol-file FILENAME
2802 remove-symbol-file -a ADDRESS
2803 Remove a symbol file added via add-symbol-file. The file to remove
2804 can be identified by its filename or by an address that lies within
2805 the boundaries of this symbol file in memory.
2808 info exceptions REGEXP
2809 Display the list of Ada exceptions defined in the program being
2810 debugged. If provided, only the exceptions whose names match REGEXP
2815 set debug symfile off|on
2817 Control display of debugging info regarding reading symbol files and
2818 symbol tables within those files
2820 set print raw frame-arguments
2821 show print raw frame-arguments
2822 Set/show whether to print frame arguments in raw mode,
2823 disregarding any defined pretty-printers.
2825 set remote trace-status-packet
2826 show remote trace-status-packet
2827 Set/show the use of remote protocol qTStatus packet.
2831 Control display of debugging messages related to Nios II targets.
2835 Control whether target-assisted range stepping is enabled.
2837 set startup-with-shell
2838 show startup-with-shell
2839 Specifies whether Unix child processes are started via a shell or
2844 Use the target memory cache for accesses to the code segment. This
2845 improves performance of remote debugging (particularly disassembly).
2847 * You can now use a literal value 'unlimited' for options that
2848 interpret 0 or -1 as meaning "unlimited". E.g., "set
2849 trace-buffer-size unlimited" is now an alias for "set
2850 trace-buffer-size -1" and "set height unlimited" is now an alias for
2853 * The "set debug symtab-create" debugging option of GDB has been changed to
2854 accept a verbosity level. 0 means "off", 1 provides basic debugging
2855 output, and values of 2 or greater provides more verbose output.
2857 * New command-line options
2859 Display the details of GDB configure-time options.
2861 * The command 'tsave' can now support new option '-ctf' to save trace
2862 buffer in Common Trace Format.
2864 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2867 * GDB now implements the C++ 'typeid' operator.
2869 * The new convenience variable $_exception holds the exception being
2870 thrown or caught at an exception-related catchpoint.
2872 * The exception-related catchpoints, like "catch throw", now accept a
2873 regular expression which can be used to filter exceptions by type.
2875 * The new convenience variable $_exitsignal is automatically set to
2876 the terminating signal number when the program being debugged dies
2877 due to an uncaught signal.
2881 ** All MI commands now accept an optional "--language" option.
2882 Support for this feature can be verified by using the "-list-features"
2883 command, which should contain "language-option".
2885 ** The new command -info-gdb-mi-command allows the user to determine
2886 whether a GDB/MI command is supported or not.
2888 ** The "^error" result record returned when trying to execute an undefined
2889 GDB/MI command now provides a variable named "code" whose content is the
2890 "undefined-command" error code. Support for this feature can be verified
2891 by using the "-list-features" command, which should contain
2892 "undefined-command-error-code".
2894 ** The -trace-save MI command can optionally save trace buffer in Common
2897 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2899 ** The command -data-list-register-values now accepts an optional
2900 "--skip-unavailable" option. When used, only the available registers
2903 ** The new command -trace-frame-collected dumps collected variables,
2904 computed expressions, tvars, memory and registers in a traceframe.
2906 ** The commands -stack-list-locals, -stack-list-arguments and
2907 -stack-list-variables now accept an option "--skip-unavailable".
2908 When used, only the available locals or arguments are displayed.
2910 ** The -exec-run command now accepts an optional "--start" option.
2911 When used, the command follows the same semantics as the "start"
2912 command, stopping the program's execution at the start of its
2913 main subprogram. Support for this feature can be verified using
2914 the "-list-features" command, which should contain
2915 "exec-run-start-option".
2917 ** The new commands -catch-assert and -catch-exceptions insert
2918 catchpoints stopping the program when Ada exceptions are raised.
2920 ** The new command -info-ada-exceptions provides the equivalent of
2921 the new "info exceptions" command.
2923 * New system-wide configuration scripts
2924 A GDB installation now provides scripts suitable for use as system-wide
2925 configuration scripts for the following systems:
2929 * GDB now supports target-assigned range stepping with remote targets.
2930 This improves the performance of stepping source lines by reducing
2931 the number of control packets from/to GDB. See "New remote packets"
2934 * GDB now understands the element 'tvar' in the XML traceframe info.
2935 It has the id of the collected trace state variables.
2937 * On S/390 targets that provide the transactional-execution feature,
2938 the program interruption transaction diagnostic block (TDB) is now
2939 represented as a number of additional "registers" in GDB.
2941 * New remote packets
2945 The vCont packet supports a new 'r' action, that tells the remote
2946 stub to step through an address range itself, without GDB
2947 involvemement at each single-step.
2949 qXfer:libraries-svr4:read's annex
2950 The previously unused annex of the qXfer:libraries-svr4:read packet
2951 is now used to support passing an argument list. The remote stub
2952 reports support for this argument list to GDB's qSupported query.
2953 The defined arguments are "start" and "prev", used to reduce work
2954 necessary for library list updating, resulting in significant
2957 * New features in the GDB remote stub, GDBserver
2959 ** GDBserver now supports target-assisted range stepping. Currently
2960 enabled on x86/x86_64 GNU/Linux targets.
2962 ** GDBserver now adds element 'tvar' in the XML in the reply to
2963 'qXfer:traceframe-info:read'. It has the id of the collected
2964 trace state variables.
2966 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2969 * New 'z' formatter for printing and examining memory, this displays the
2970 value as hexadecimal zero padded on the left to the size of the type.
2972 * GDB can now use Windows x64 unwinding data.
2974 * The "set remotebaud" command has been replaced by "set serial baud".
2975 Similarly, "show remotebaud" has been replaced by "show serial baud".
2976 The "set remotebaud" and "show remotebaud" commands are still available
2977 to provide backward compatibility with older versions of GDB.
2979 *** Changes in GDB 7.6
2981 * Target record has been renamed to record-full.
2982 Record/replay is now enabled with the "record full" command.
2983 This also affects settings that are associated with full record/replay
2984 that have been moved from "set/show record" to "set/show record full":
2986 set|show record full insn-number-max
2987 set|show record full stop-at-limit
2988 set|show record full memory-query
2990 * A new record target "record-btrace" has been added. The new target
2991 uses hardware support to record the control-flow of a process. It
2992 does not support replaying the execution, but it implements the
2993 below new commands for investigating the recorded execution log.
2994 This new recording method can be enabled using:
2998 The "record-btrace" target is only available on Intel Atom processors
2999 and requires a Linux kernel 2.6.32 or later.
3001 * Two new commands have been added for record/replay to give information
3002 about the recorded execution without having to replay the execution.
3003 The commands are only supported by "record btrace".
3005 record instruction-history prints the execution history at
3006 instruction granularity
3008 record function-call-history prints the execution history at
3009 function granularity
3011 * New native configurations
3013 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3014 FreeBSD/powerpc powerpc*-*-freebsd
3015 x86_64/Cygwin x86_64-*-cygwin*
3016 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3020 ARM AArch64 aarch64*-*-elf
3021 ARM AArch64 GNU/Linux aarch64*-*-linux
3022 Lynx 178 PowerPC powerpc-*-lynx*178
3023 x86_64/Cygwin x86_64-*-cygwin*
3024 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3026 * If the configured location of system.gdbinit file (as given by the
3027 --with-system-gdbinit option at configure time) is in the
3028 data-directory (as specified by --with-gdb-datadir at configure
3029 time) or in one of its subdirectories, then GDB will look for the
3030 system-wide init file in the directory specified by the
3031 --data-directory command-line option.
3033 * New command line options:
3035 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3036 other initialization files, unlike -nx which disables all of them.
3038 * Removed command line options
3040 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3043 * The 'ptype' and 'whatis' commands now accept an argument to control
3046 * 'info proc' now works on some core files.
3050 ** Vectors can be created with gdb.Type.vector.
3052 ** Python's atexit.register now works in GDB.
3054 ** Types can be pretty-printed via a Python API.
3056 ** Python 3 is now supported (in addition to Python 2.4 or later)
3058 ** New class gdb.Architecture exposes GDB's internal representation
3059 of architecture in the Python API.
3061 ** New method Frame.architecture returns the gdb.Architecture object
3062 corresponding to the frame's architecture.
3064 * New Python-based convenience functions:
3066 ** $_memeq(buf1, buf2, length)
3067 ** $_streq(str1, str2)
3069 ** $_regex(str, regex)
3071 * The 'cd' command now defaults to using '~' (the home directory) if not
3074 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3075 default for GCC since November 2000.
3077 * The command 'forward-search' can now be abbreviated as 'fo'.
3079 * The command 'info tracepoints' can now display 'installed on target'
3080 or 'not installed on target' for each non-pending location of tracepoint.
3082 * New configure options
3084 --enable-libmcheck/--disable-libmcheck
3085 By default, development versions are built with -lmcheck on hosts
3086 that support it, in order to help track memory corruption issues.
3087 Release versions, on the other hand, are built without -lmcheck
3088 by default. The --enable-libmcheck/--disable-libmcheck configure
3089 options allow the user to override that default.
3090 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3091 This configure option allows the user to build GDB with
3092 libbabeltrace using which GDB can read Common Trace Format data.
3094 * New commands (for set/show, see "New options" below)
3097 Catch signals. This is similar to "handle", but allows commands and
3098 conditions to be attached.
3101 List the BFDs known to GDB.
3103 python-interactive [command]
3105 Start a Python interactive prompt, or evaluate the optional command
3106 and print the result of expressions.
3109 "py" is a new alias for "python".
3111 enable type-printer [name]...
3112 disable type-printer [name]...
3113 Enable or disable type printers.
3117 ** For the Renesas Super-H architecture, the "regs" command has been removed
3118 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3123 set print type methods (on|off)
3124 show print type methods
3125 Control whether method declarations are displayed by "ptype".
3126 The default is to show them.
3128 set print type typedefs (on|off)
3129 show print type typedefs
3130 Control whether typedef definitions are displayed by "ptype".
3131 The default is to show them.
3133 set filename-display basename|relative|absolute
3134 show filename-display
3135 Control the way in which filenames is displayed.
3136 The default is "relative", which preserves previous behavior.
3138 set trace-buffer-size
3139 show trace-buffer-size
3140 Request target to change the size of trace buffer.
3142 set remote trace-buffer-size-packet auto|on|off
3143 show remote trace-buffer-size-packet
3144 Control the use of the remote protocol `QTBuffer:size' packet.
3148 Control display of debugging messages related to ARM AArch64.
3151 set debug coff-pe-read
3152 show debug coff-pe-read
3153 Control display of debugging messages related to reading of COFF/PE
3158 Control display of debugging messages related to Mach-O symbols
3161 set debug notification
3162 show debug notification
3163 Control display of debugging info for async remote notification.
3167 ** Command parameter changes are now notified using new async record
3168 "=cmd-param-changed".
3169 ** Trace frame changes caused by command "tfind" are now notified using
3170 new async record "=traceframe-changed".
3171 ** The creation, deletion and modification of trace state variables
3172 are now notified using new async records "=tsv-created",
3173 "=tsv-deleted" and "=tsv-modified".
3174 ** The start and stop of process record are now notified using new
3175 async record "=record-started" and "=record-stopped".
3176 ** Memory changes are now notified using new async record
3178 ** The data-disassemble command response will include a "fullname" field
3179 containing the absolute file name when source has been requested.
3180 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3181 command, to allow pattern filling of memory areas.
3182 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3183 library load/unload events.
3184 ** The response to breakpoint commands and breakpoint async records
3185 includes an "installed" field containing a boolean state about each
3186 non-pending tracepoint location is whether installed on target or not.
3187 ** Output of the "-trace-status" command includes a "trace-file" field
3188 containing the name of the trace file being examined. This field is
3189 optional, and only present when examining a trace file.
3190 ** The "fullname" field is now always present along with the "file" field,
3191 even if the file cannot be found by GDB.
3193 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3194 You must have the LZMA library available when configuring GDB for this
3195 feature to be enabled. For more information, see:
3196 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3198 * New remote packets
3201 Set the size of trace buffer. The remote stub reports support for this
3202 packet to gdb's qSupported query.
3205 Enable Branch Trace Store (BTS)-based branch tracing for the current
3206 thread. The remote stub reports support for this packet to gdb's
3210 Disable branch tracing for the current thread. The remote stub reports
3211 support for this packet to gdb's qSupported query.
3214 Read the traced branches for the current thread. The remote stub
3215 reports support for this packet to gdb's qSupported query.
3217 *** Changes in GDB 7.5
3219 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3220 for more x32 ABI info.
3222 * GDB now supports access to MIPS DSP registers on Linux targets.
3224 * GDB now supports debugging microMIPS binaries.
3226 * The "info os" command on GNU/Linux can now display information on
3227 several new classes of objects managed by the operating system:
3228 "info os procgroups" lists process groups
3229 "info os files" lists file descriptors
3230 "info os sockets" lists internet-domain sockets
3231 "info os shm" lists shared-memory regions
3232 "info os semaphores" lists semaphores
3233 "info os msg" lists message queues
3234 "info os modules" lists loaded kernel modules
3236 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3237 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3238 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3239 options and inspect the probe arguments using the new $_probe_arg family
3240 of convenience variables. You can obtain more information about SystemTap
3241 in <http://sourceware.org/systemtap/>.
3243 * GDB now supports reversible debugging on ARM, it allows you to
3244 debug basic ARM and THUMB instructions, and provides
3245 record/replay support.
3247 * The option "symbol-reloading" has been deleted as it is no longer used.
3251 ** GDB commands implemented in Python can now be put in command class
3254 ** The "maint set python print-stack on|off" is now deleted.
3256 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3257 apply "flag enum"-style pretty-printing to any enum.
3259 ** gdb.lookup_symbol can now work when there is no current frame.
3261 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3262 the source at which the symbol was defined.
3264 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3265 method 'value'. The former indicates whether the symbol needs a
3266 frame in order to compute its value, and the latter computes the
3269 ** A new method 'referenced_value' on gdb.Value objects which can
3270 dereference pointer as well as C++ reference values.
3272 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3273 which return the global and static blocks (as gdb.Block objects),
3274 of the underlying symbol table, respectively.
3276 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3277 object associated with a PC value.
3279 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3280 of the address range occupied by code for the current source line.
3282 * Go language support.
3283 GDB now supports debugging programs written in the Go programming
3286 * GDBserver now supports stdio connections.
3287 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3289 * The binary "gdbtui" can no longer be built or installed.
3290 Use "gdb -tui" instead.
3292 * GDB will now print "flag" enums specially. A flag enum is one where
3293 all the enumerator values have no bits in common when pairwise
3294 "and"ed. When printing a value whose type is a flag enum, GDB will
3295 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3296 (gdb) print (enum E) 3
3299 * The filename part of a linespec will now match trailing components
3300 of a source file name. For example, "break gcc/expr.c:1000" will
3301 now set a breakpoint in build/gcc/expr.c, but not
3302 build/libcpp/expr.c.
3304 * The "info proc" and "generate-core-file" commands will now also
3305 work on remote targets connected to GDBserver on Linux.
3307 * The command "info catch" has been removed. It has been disabled
3308 since December 2007.
3310 * The "catch exception" and "catch assert" commands now accept
3311 a condition at the end of the command, much like the "break"
3312 command does. For instance:
3314 (gdb) catch exception Constraint_Error if Barrier = True
3316 Previously, it was possible to add a condition to such catchpoints,
3317 but it had to be done as a second step, after the catchpoint had been
3318 created, using the "condition" command.
3320 * The "info static-tracepoint-marker" command will now also work on
3321 native Linux targets with in-process agent.
3323 * GDB can now set breakpoints on inlined functions.
3325 * The .gdb_index section has been updated to include symbols for
3326 inlined functions. GDB will ignore older .gdb_index sections by
3327 default, which could cause symbol files to be loaded more slowly
3328 until their .gdb_index sections can be recreated. The new command
3329 "set use-deprecated-index-sections on" will cause GDB to use any older
3330 .gdb_index sections it finds. This will restore performance, but the
3331 ability to set breakpoints on inlined functions will be lost in symbol
3332 files with older .gdb_index sections.
3334 The .gdb_index section has also been updated to record more information
3335 about each symbol. This speeds up the "info variables", "info functions"
3336 and "info types" commands when used with programs having the .gdb_index
3337 section, as well as speeding up debugging with shared libraries using
3338 the .gdb_index section.
3340 * Ada support for GDB/MI Variable Objects has been added.
3342 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3347 ** New command -info-os is the MI equivalent of "info os".
3349 ** Output logs ("set logging" and related) now include MI output.
3353 ** "set use-deprecated-index-sections on|off"
3354 "show use-deprecated-index-sections on|off"
3355 Controls the use of deprecated .gdb_index sections.
3357 ** "catch load" and "catch unload" can be used to stop when a shared
3358 library is loaded or unloaded, respectively.
3360 ** "enable count" can be used to auto-disable a breakpoint after
3363 ** "info vtbl" can be used to show the virtual method tables for
3364 C++ and Java objects.
3366 ** "explore" and its sub commands "explore value" and "explore type"
3367 can be used to recursively explore values and types of
3368 expressions. These commands are available only if GDB is
3369 configured with '--with-python'.
3371 ** "info auto-load" shows status of all kinds of auto-loaded files,
3372 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3373 sequences of commands files, "info auto-load python-scripts"
3374 shows status of auto-loading Python script files,
3375 "info auto-load local-gdbinit" shows status of loading init file
3376 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3377 status of inferior specific thread debugging shared library loading.
3379 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3380 and "show auto-load-scripts" commands have been deprecated, use their
3381 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3382 and "show auto-load python-scripts" counterparts instead.
3384 ** "dprintf location,format,args..." creates a dynamic printf, which
3385 is basically a breakpoint that does a printf and immediately
3386 resumes your program's execution, so it is like a printf that you
3387 can insert dynamically at runtime instead of at compiletime.
3389 ** "set print symbol"
3391 Controls whether GDB attempts to display the symbol, if any,
3392 corresponding to addresses it prints. This defaults to "on", but
3393 you can set it to "off" to restore GDB's previous behavior.
3395 * Deprecated commands
3397 ** For the Renesas Super-H architecture, the "regs" command has been
3398 deprecated, and "info all-registers" should be used instead.
3402 Renesas RL78 rl78-*-elf
3403 HP OpenVMS ia64 ia64-hp-openvms*
3405 * GDBserver supports evaluation of breakpoint conditions. When
3406 support is advertised by GDBserver, GDB may be told to send the
3407 breakpoint conditions in bytecode form to GDBserver. GDBserver
3408 will only report the breakpoint trigger to GDB when its condition
3413 set mips compression
3414 show mips compression
3415 Select the compressed ISA encoding used in functions that have no symbol
3416 information available. The encoding can be set to either of:
3419 and is updated automatically from ELF file flags if available.
3421 set breakpoint condition-evaluation
3422 show breakpoint condition-evaluation
3423 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3424 GDBserver ("target"). Default option "auto" chooses the most efficient
3426 This option can improve debugger efficiency depending on the speed of the
3430 Disable auto-loading globally.
3433 Show auto-loading setting of all kinds of auto-loaded files.
3435 set auto-load gdb-scripts on|off
3436 show auto-load gdb-scripts
3437 Control auto-loading of GDB canned sequences of commands files.
3439 set auto-load python-scripts on|off
3440 show auto-load python-scripts
3441 Control auto-loading of Python script files.
3443 set auto-load local-gdbinit on|off
3444 show auto-load local-gdbinit
3445 Control loading of init file (.gdbinit) from current directory.
3447 set auto-load libthread-db on|off
3448 show auto-load libthread-db
3449 Control auto-loading of inferior specific thread debugging shared library.
3451 set auto-load scripts-directory <dir1>[:<dir2>...]
3452 show auto-load scripts-directory
3453 Set a list of directories from which to load auto-loaded scripts.
3454 Automatically loaded Python scripts and GDB scripts are located in one
3455 of the directories listed by this option.
3456 The delimiter (':' above) may differ according to the host platform.
3458 set auto-load safe-path <dir1>[:<dir2>...]
3459 show auto-load safe-path
3460 Set a list of directories from which it is safe to auto-load files.
3461 The delimiter (':' above) may differ according to the host platform.
3463 set debug auto-load on|off
3464 show debug auto-load
3465 Control display of debugging info for auto-loading the files above.
3467 set dprintf-style gdb|call|agent
3469 Control the way in which a dynamic printf is performed; "gdb"
3470 requests a GDB printf command, while "call" causes dprintf to call a
3471 function in the inferior. "agent" requests that the target agent
3472 (such as GDBserver) do the printing.
3474 set dprintf-function <expr>
3475 show dprintf-function
3476 set dprintf-channel <expr>
3477 show dprintf-channel
3478 Set the function and optional first argument to the call when using
3479 the "call" style of dynamic printf.
3481 set disconnected-dprintf on|off
3482 show disconnected-dprintf
3483 Control whether agent-style dynamic printfs continue to be in effect
3484 after GDB disconnects.
3486 * New configure options
3488 --with-auto-load-dir
3489 Configure default value for the 'set auto-load scripts-directory'
3490 setting above. It defaults to '$debugdir:$datadir/auto-load',
3491 $debugdir representing global debugging info directories (available
3492 via 'show debug-file-directory') and $datadir representing GDB's data
3493 directory (available via 'show data-directory').
3495 --with-auto-load-safe-path
3496 Configure default value for the 'set auto-load safe-path' setting
3497 above. It defaults to the --with-auto-load-dir setting.
3499 --without-auto-load-safe-path
3500 Set 'set auto-load safe-path' to '/', effectively disabling this
3503 * New remote packets
3505 z0/z1 conditional breakpoints extension
3507 The z0/z1 breakpoint insertion packets have been extended to carry
3508 a list of conditional expressions over to the remote stub depending on the
3509 condition evaluation mode. The use of this extension can be controlled
3510 via the "set remote conditional-breakpoints-packet" command.
3514 Specify the signals which the remote stub may pass to the debugged
3515 program without GDB involvement.
3517 * New command line options
3519 --init-command=FILE, -ix Like --command, -x but execute it
3520 before loading inferior.
3521 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3522 execute it before loading inferior.
3524 *** Changes in GDB 7.4
3526 * GDB now handles ambiguous linespecs more consistently; the existing
3527 FILE:LINE support has been expanded to other types of linespecs. A
3528 breakpoint will now be set on all matching locations in all
3529 inferiors, and locations will be added or removed according to
3532 * GDB now allows you to skip uninteresting functions and files when
3533 stepping with the "skip function" and "skip file" commands.
3535 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3536 and "show remote hardware-watchpoint-length-limit". These allows to
3537 set or show the maximum length limit (in bytes) of a remote
3538 target hardware watchpoint.
3540 This allows e.g. to use "unlimited" hardware watchpoints with the
3541 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3542 watchpoints are slower than real hardware watchpoints but are
3543 significantly faster than gdb software watchpoints.
3547 ** The register_pretty_printer function in module gdb.printing now takes
3548 an optional `replace' argument. If True, the new printer replaces any
3551 ** The "maint set python print-stack on|off" command has been
3552 deprecated and will be deleted in GDB 7.5.
3553 A new command: "set python print-stack none|full|message" has
3554 replaced it. Additionally, the default for "print-stack" is
3555 now "message", which just prints the error message without
3558 ** A prompt substitution hook (prompt_hook) is now available to the
3561 ** A new Python module, gdb.prompt has been added to the GDB Python
3562 modules library. This module provides functionality for
3563 escape sequences in prompts (used by set/show
3564 extended-prompt). These escape sequences are replaced by their
3565 corresponding value.
3567 ** Python commands and convenience-functions located in
3568 'data-directory'/python/gdb/command and
3569 'data-directory'/python/gdb/function are now automatically loaded
3572 ** Blocks now provide four new attributes. global_block and
3573 static_block will return the global and static blocks
3574 respectively. is_static and is_global are boolean attributes
3575 that indicate if the block is one of those two types.
3577 ** Symbols now provide the "type" attribute, the type of the symbol.
3579 ** The "gdb.breakpoint" function has been deprecated in favor of
3582 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3583 of a function. This class is based on the "finish" command
3584 available in the CLI.
3586 ** Type objects for struct and union types now allow access to
3587 the fields using standard Python dictionary (mapping) methods.
3588 For example, "some_type['myfield']" now works, as does
3589 "some_type.items()".
3591 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3594 ** A new function, "deep_items" has been added to the gdb.types
3595 module in the GDB Python modules library. This function returns
3596 an iterator over the fields of a struct or union type. Unlike
3597 the standard Python "iteritems" method, it will recursively traverse
3598 any anonymous fields.
3602 ** "*stopped" events can report several new "reason"s, such as
3605 ** Breakpoint changes are now notified using new async records, like
3606 "=breakpoint-modified".
3608 ** New command -ada-task-info.
3610 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3611 $sdir specifies the default system locations of shared libraries.
3612 $pdir specifies the directory where the libpthread used by the application
3615 GDB no longer looks in $sdir and $pdir after it has searched the directories
3616 mentioned in libthread-db-search-path. If you want to search those
3617 directories, they must be specified in libthread-db-search-path.
3618 The default value of libthread-db-search-path on GNU/Linux and Solaris
3619 systems is now "$sdir:$pdir".
3621 $pdir is not supported by gdbserver, it is currently ignored.
3622 $sdir is supported by gdbserver.
3624 * New configure option --with-iconv-bin.
3625 When using the internationalization support like the one in the GNU C
3626 library, GDB will invoke the "iconv" program to get a list of supported
3627 character sets. If this program lives in a non-standard location, one can
3628 use this option to specify where to find it.
3630 * When natively debugging programs on PowerPC BookE processors running
3631 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3632 watchpoints, which specify a mask in addition to an address to watch.
3633 The mask specifies that some bits of an address (the bits which are
3634 reset in the mask) should be ignored when matching the address accessed
3635 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3636 section in the user manual for more details.
3638 * The new option --once causes GDBserver to stop listening for connections once
3639 the first connection is made. The listening port used by GDBserver will
3640 become available after that.
3642 * New commands "info macros" and "alias" have been added.
3644 * New function parameters suffix @entry specifies value of function parameter
3645 at the time the function got called. Entry values are available only since
3651 "!" is now an alias of the "shell" command.
3652 Note that no space is needed between "!" and SHELL COMMAND.
3656 watch EXPRESSION mask MASK_VALUE
3657 The watch command now supports the mask argument which allows creation
3658 of masked watchpoints, if the current architecture supports this feature.
3660 info auto-load-scripts [REGEXP]
3661 This command was formerly named "maintenance print section-scripts".
3662 It is now generally useful and is no longer a maintenance-only command.
3664 info macro [-all] [--] MACRO
3665 The info macro command has new options `-all' and `--'. The first for
3666 printing all definitions of a macro. The second for explicitly specifying
3667 the end of arguments and the beginning of the macro name in case the macro
3668 name starts with a hyphen.
3670 collect[/s] EXPRESSIONS
3671 The tracepoint collect command now takes an optional modifier "/s"
3672 that directs it to dereference pointer-to-character types and
3673 collect the bytes of memory up to a zero byte. The behavior is
3674 similar to what you see when you use the regular print command on a
3675 string. An optional integer following the "/s" sets a bound on the
3676 number of bytes that will be collected.
3679 The trace start command now interprets any supplied arguments as a
3680 note to be recorded with the trace run, with an effect similar to
3681 setting the variable trace-notes.
3684 The trace stop command now interprets any arguments as a note to be
3685 mentioned along with the tstatus report that the trace was stopped
3686 with a command. The effect is similar to setting the variable
3689 * Tracepoints can now be enabled and disabled at any time after a trace
3690 experiment has been started using the standard "enable" and "disable"
3691 commands. It is now possible to start a trace experiment with no enabled
3692 tracepoints; GDB will display a warning, but will allow the experiment to
3693 begin, assuming that tracepoints will be enabled as needed while the trace
3696 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3697 locations with 4-byte instructions, when they were previously
3698 limited to locations with instructions of 5 bytes or longer.
3702 set debug dwarf2-read
3703 show debug dwarf2-read
3704 Turns on or off display of debugging messages related to reading
3705 DWARF debug info. The default is off.
3707 set debug symtab-create
3708 show debug symtab-create
3709 Turns on or off display of debugging messages related to symbol table
3710 creation. The default is off.
3713 show extended-prompt
3714 Set the GDB prompt, and allow escape sequences to be inserted to
3715 display miscellaneous information (see 'help set extended-prompt'
3716 for the list of sequences). This prompt (and any information
3717 accessed through the escape sequences) is updated every time the
3718 prompt is displayed.
3720 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3721 show print entry-values
3722 Set printing of frame argument values at function entry. In some cases
3723 GDB can determine the value of function argument which was passed by the
3724 function caller, even if the value was modified inside the called function.
3726 set debug entry-values
3727 show debug entry-values
3728 Control display of debugging info for determining frame argument values at
3729 function entry and virtual tail call frames.
3731 set basenames-may-differ
3732 show basenames-may-differ
3733 Set whether a source file may have multiple base names.
3734 (A "base name" is the name of a file with the directory part removed.
3735 Example: The base name of "/home/user/hello.c" is "hello.c".)
3736 If set, GDB will canonicalize file names (e.g., expand symlinks)
3737 before comparing them. Canonicalization is an expensive operation,
3738 but it allows the same file be known by more than one base name.
3739 If not set (the default), all source files are assumed to have just
3740 one base name, and gdb will do file name comparisons more efficiently.
3746 Set a user name and notes for the current and any future trace runs.
3747 This is useful for long-running and/or disconnected traces, to
3748 inform others (or yourself) as to who is running the trace, supply
3749 contact information, or otherwise explain what is going on.
3751 set trace-stop-notes
3752 show trace-stop-notes
3753 Set a note attached to the trace run, that is displayed when the
3754 trace has been stopped by a tstop command. This is useful for
3755 instance as an explanation, if you are stopping a trace run that was
3756 started by someone else.
3758 * New remote packets
3762 Dynamically enable a tracepoint in a started trace experiment.
3766 Dynamically disable a tracepoint in a started trace experiment.
3770 Set the user and notes of the trace run.
3774 Query the current status of a tracepoint.
3778 Query the minimum length of instruction at which a fast tracepoint may
3781 * Dcache size (number of lines) and line-size are now runtime-configurable
3782 via "set dcache line" and "set dcache line-size" commands.
3786 Texas Instruments TMS320C6x tic6x-*-*
3790 Renesas RL78 rl78-*-elf
3792 *** Changes in GDB 7.3.1
3794 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3796 *** Changes in GDB 7.3
3798 * GDB has a new command: "thread find [REGEXP]".
3799 It finds the thread id whose name, target id, or thread extra info
3800 matches the given regular expression.
3802 * The "catch syscall" command now works on mips*-linux* targets.
3804 * The -data-disassemble MI command now supports modes 2 and 3 for
3805 dumping the instruction opcodes.
3807 * New command line options
3809 -data-directory DIR Specify DIR as the "data-directory".
3810 This is mostly for testing purposes.
3812 * The "maint set python auto-load on|off" command has been renamed to
3813 "set auto-load-scripts on|off".
3815 * GDB has a new command: "set directories".
3816 It is like the "dir" command except that it replaces the
3817 source path list instead of augmenting it.
3819 * GDB now understands thread names.
3821 On GNU/Linux, "info threads" will display the thread name as set by
3822 prctl or pthread_setname_np.
3824 There is also a new command, "thread name", which can be used to
3825 assign a name internally for GDB to display.
3828 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3829 has been integrated into GDB.
3833 ** The function gdb.Write now accepts an optional keyword 'stream'.
3834 This keyword, when provided, will direct the output to either
3835 stdout, stderr, or GDB's logging output.
3837 ** Parameters can now be be sub-classed in Python, and in particular
3838 you may implement the get_set_doc and get_show_doc functions.
3839 This improves how Parameter set/show documentation is processed
3840 and allows for more dynamic content.
3842 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3843 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3844 have an is_valid method.
3846 ** Breakpoints can now be sub-classed in Python, and in particular
3847 you may implement a 'stop' function that is executed each time
3848 the inferior reaches that breakpoint.
3850 ** New function gdb.lookup_global_symbol looks up a global symbol.
3852 ** GDB values in Python are now callable if the value represents a
3853 function. For example, if 'some_value' represents a function that
3854 takes two integer parameters and returns a value, you can call
3855 that function like so:
3857 result = some_value (10,20)
3859 ** Module gdb.types has been added.
3860 It contains a collection of utilities for working with gdb.Types objects:
3861 get_basic_type, has_field, make_enum_dict.
3863 ** Module gdb.printing has been added.
3864 It contains utilities for writing and registering pretty-printers.
3865 New classes: PrettyPrinter, SubPrettyPrinter,
3866 RegexpCollectionPrettyPrinter.
3867 New function: register_pretty_printer.
3869 ** New commands "info pretty-printers", "enable pretty-printer" and
3870 "disable pretty-printer" have been added.
3872 ** gdb.parameter("directories") is now available.
3874 ** New function gdb.newest_frame returns the newest frame in the
3877 ** The gdb.InferiorThread class has a new "name" attribute. This
3878 holds the thread's name.
3880 ** Python Support for Inferior events.
3881 Python scripts can add observers to be notified of events
3882 occurring in the process being debugged.
3883 The following events are currently supported:
3884 - gdb.events.cont Continue event.
3885 - gdb.events.exited Inferior exited event.
3886 - gdb.events.stop Signal received, and Breakpoint hit events.
3890 ** GDB now puts template parameters in scope when debugging in an
3891 instantiation. For example, if you have:
3893 template<int X> int func (void) { return X; }
3895 then if you step into func<5>, "print X" will show "5". This
3896 feature requires proper debuginfo support from the compiler; it
3897 was added to GCC 4.5.
3899 ** The motion commands "next", "finish", "until", and "advance" now
3900 work better when exceptions are thrown. In particular, GDB will
3901 no longer lose control of the inferior; instead, the GDB will
3902 stop the inferior at the point at which the exception is caught.
3903 This functionality requires a change in the exception handling
3904 code that was introduced in GCC 4.5.
3906 * GDB now follows GCC's rules on accessing volatile objects when
3907 reading or writing target state during expression evaluation.
3908 One notable difference to prior behavior is that "print x = 0"
3909 no longer generates a read of x; the value of the assignment is
3910 now always taken directly from the value being assigned.
3912 * GDB now has some support for using labels in the program's source in
3913 linespecs. For instance, you can use "advance label" to continue
3914 execution to a label.
3916 * GDB now has support for reading and writing a new .gdb_index
3917 section. This section holds a fast index of DWARF debugging
3918 information and can be used to greatly speed up GDB startup and
3919 operation. See the documentation for `save gdb-index' for details.
3921 * The "watch" command now accepts an optional "-location" argument.
3922 When used, this causes GDB to watch the memory referred to by the
3923 expression. Such a watchpoint is never deleted due to it going out
3926 * GDB now supports thread debugging of core dumps on GNU/Linux.
3928 GDB now activates thread debugging using the libthread_db library
3929 when debugging GNU/Linux core dumps, similarly to when debugging
3930 live processes. As a result, when debugging a core dump file, GDB
3931 is now able to display pthread_t ids of threads. For example, "info
3932 threads" shows the same output as when debugging the process when it
3933 was live. In earlier releases, you'd see something like this:
3936 * 1 LWP 6780 main () at main.c:10
3938 While now you see this:
3941 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3943 It is also now possible to inspect TLS variables when debugging core
3946 When debugging a core dump generated on a machine other than the one
3947 used to run GDB, you may need to point GDB at the correct
3948 libthread_db library with the "set libthread-db-search-path"
3949 command. See the user manual for more details on this command.
3951 * When natively debugging programs on PowerPC BookE processors running
3952 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3953 which stop execution of the inferior whenever it executes an instruction
3954 at any address within the specified range. See the "PowerPC Embedded"
3955 section in the user manual for more details.
3957 * New features in the GDB remote stub, GDBserver
3959 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3960 and i686 LynxOS (version 5.x).
3962 ** GDBserver is now supported on Blackfin Linux.
3964 * New native configurations
3966 ia64 HP-UX ia64-*-hpux*
3970 Analog Devices, Inc. Blackfin Processor bfin-*
3972 * Ada task switching is now supported on sparc-elf targets when
3973 debugging a program using the Ravenscar Profile. For more information,
3974 see the "Tasking Support when using the Ravenscar Profile" section
3975 in the GDB user manual.
3977 * Guile support was removed.
3979 * New features in the GNU simulator
3981 ** The --map-info flag lists all known core mappings.
3983 ** CFI flashes may be simulated via the "cfi" device.
3985 *** Changes in GDB 7.2
3987 * Shared library support for remote targets by default
3989 When GDB is configured for a generic, non-OS specific target, like
3990 for example, --target=arm-eabi or one of the many *-*-elf targets,
3991 GDB now queries remote stubs for loaded shared libraries using the
3992 `qXfer:libraries:read' packet. Previously, shared library support
3993 was always disabled for such configurations.
3997 ** Argument Dependent Lookup (ADL)
3999 In C++ ADL lookup directs function search to the namespaces of its
4000 arguments even if the namespace has not been imported.
4010 Here the compiler will search for `foo' in the namespace of 'b'
4011 and find A::foo. GDB now supports this. This construct is commonly
4012 used in the Standard Template Library for operators.
4014 ** Improved User Defined Operator Support
4016 In addition to member operators, GDB now supports lookup of operators
4017 defined in a namespace and imported with a `using' directive, operators
4018 defined in the global scope, operators imported implicitly from an
4019 anonymous namespace, and the ADL operators mentioned in the previous
4021 GDB now also supports proper overload resolution for all the previously
4022 mentioned flavors of operators.
4024 ** static const class members
4026 Printing of static const class members that are initialized in the
4027 class definition has been fixed.
4029 * Windows Thread Information Block access.
4031 On Windows targets, GDB now supports displaying the Windows Thread
4032 Information Block (TIB) structure. This structure is visible either
4033 by using the new command `info w32 thread-information-block' or, by
4034 dereferencing the new convenience variable named `$_tlb', a
4035 thread-specific pointer to the TIB. This feature is also supported
4036 when remote debugging using GDBserver.
4038 * Static tracepoints
4040 Static tracepoints are calls in the user program into a tracing
4041 library. One such library is a port of the LTTng kernel tracer to
4042 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4043 When debugging with GDBserver, GDB now supports combining the GDB
4044 tracepoint machinery with such libraries. For example: the user can
4045 use GDB to probe a static tracepoint marker (a call from the user
4046 program into the tracing library) with the new "strace" command (see
4047 "New commands" below). This creates a "static tracepoint" in the
4048 breakpoint list, that can be manipulated with the same feature set
4049 as fast and regular tracepoints. E.g., collect registers, local and
4050 global variables, collect trace state variables, and define
4051 tracepoint conditions. In addition, the user can collect extra
4052 static tracepoint marker specific data, by collecting the new
4053 $_sdata internal variable. When analyzing the trace buffer, you can
4054 inspect $_sdata like any other variable available to GDB. For more
4055 information, see the "Tracepoints" chapter in GDB user manual. New
4056 remote packets have been defined to support static tracepoints, see
4057 the "New remote packets" section below.
4059 * Better reconstruction of tracepoints after disconnected tracing
4061 GDB will attempt to download the original source form of tracepoint
4062 definitions when starting a trace run, and then will upload these
4063 upon reconnection to the target, resulting in a more accurate
4064 reconstruction of the tracepoints that are in use on the target.
4068 You can now exercise direct control over the ways that GDB can
4069 affect your program. For instance, you can disallow the setting of
4070 breakpoints, so that the program can run continuously (assuming
4071 non-stop mode). In addition, the "observer" variable is available
4072 to switch all of the different controls; in observer mode, GDB
4073 cannot affect the target's behavior at all, which is useful for
4074 tasks like diagnosing live systems in the field.
4076 * The new convenience variable $_thread holds the number of the
4079 * New remote packets
4083 Return the address of the Windows Thread Information Block of a given thread.
4087 In response to several of the tracepoint packets, the target may now
4088 also respond with a number of intermediate `qRelocInsn' request
4089 packets before the final result packet, to have GDB handle
4090 relocating an instruction to execute at a different address. This
4091 is particularly useful for stubs that support fast tracepoints. GDB
4092 reports support for this feature in the qSupported packet.
4096 List static tracepoint markers in the target program.
4100 List static tracepoint markers at a given address in the target
4103 qXfer:statictrace:read
4105 Read the static trace data collected (by a `collect $_sdata'
4106 tracepoint action). The remote stub reports support for this packet
4107 to gdb's qSupported query.
4111 Send the current settings of GDB's permission flags.
4115 Send part of the source (textual) form of a tracepoint definition,
4116 which includes location, conditional, and action list.
4118 * The source command now accepts a -s option to force searching for the
4119 script in the source search path even if the script name specifies
4122 * New features in the GDB remote stub, GDBserver
4124 - GDBserver now support tracepoints (including fast tracepoints, and
4125 static tracepoints). The feature is currently supported by the
4126 i386-linux and amd64-linux builds. See the "Tracepoints support
4127 in gdbserver" section in the manual for more information.
4129 GDBserver JIT compiles the tracepoint's conditional agent
4130 expression bytecode into native code whenever possible for low
4131 overhead dynamic tracepoints conditionals. For such tracepoints,
4132 an expression that examines program state is evaluated when the
4133 tracepoint is reached, in order to determine whether to capture
4134 trace data. If the condition is simple and false, processing the
4135 tracepoint finishes very quickly and no data is gathered.
4137 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4138 for static tracepoints support.
4140 - GDBserver now supports x86_64 Windows 64-bit debugging.
4142 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4143 it understands register description.
4145 * The --batch flag now disables pagination and queries.
4147 * X86 general purpose registers
4149 GDB now supports reading/writing byte, word and double-word x86
4150 general purpose registers directly. This means you can use, say,
4151 $ah or $ax to refer, respectively, to the byte register AH and
4152 16-bit word register AX that are actually portions of the 32-bit
4153 register EAX or 64-bit register RAX.
4155 * The `commands' command now accepts a range of breakpoints to modify.
4156 A plain `commands' following a command that creates multiple
4157 breakpoints affects all the breakpoints set by that command. This
4158 applies to breakpoints set by `rbreak', and also applies when a
4159 single `break' command creates multiple breakpoints (e.g.,
4160 breakpoints on overloaded c++ functions).
4162 * The `rbreak' command now accepts a filename specification as part of
4163 its argument, limiting the functions selected by the regex to those
4164 in the specified file.
4166 * Support for remote debugging Windows and SymbianOS shared libraries
4167 from Unix hosts has been improved. Non Windows GDB builds now can
4168 understand target reported file names that follow MS-DOS based file
4169 system semantics, such as file names that include drive letters and
4170 use the backslash character as directory separator. This makes it
4171 possible to transparently use the "set sysroot" and "set
4172 solib-search-path" on Unix hosts to point as host copies of the
4173 target's shared libraries. See the new command "set
4174 target-file-system-kind" described below, and the "Commands to
4175 specify files" section in the user manual for more information.
4179 eval template, expressions...
4180 Convert the values of one or more expressions under the control
4181 of the string template to a command line, and call it.
4183 set target-file-system-kind unix|dos-based|auto
4184 show target-file-system-kind
4185 Set or show the assumed file system kind for target reported file
4188 save breakpoints <filename>
4189 Save all current breakpoint definitions to a file suitable for use
4190 in a later debugging session. To read the saved breakpoint
4191 definitions, use the `source' command.
4193 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4196 info static-tracepoint-markers
4197 Display information about static tracepoint markers in the target.
4199 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4200 Define a static tracepoint by probing a marker at the given
4201 function, line, address, or marker ID.
4205 Enable and disable observer mode.
4207 set may-write-registers on|off
4208 set may-write-memory on|off
4209 set may-insert-breakpoints on|off
4210 set may-insert-tracepoints on|off
4211 set may-insert-fast-tracepoints on|off
4212 set may-interrupt on|off
4213 Set individual permissions for GDB effects on the target. Note that
4214 some of these settings can have undesirable or surprising
4215 consequences, particularly when changed in the middle of a session.
4216 For instance, disabling the writing of memory can prevent
4217 breakpoints from being inserted, cause single-stepping to fail, or
4218 even crash your program, if you disable after breakpoints have been
4219 inserted. However, GDB should not crash.
4221 set record memory-query on|off
4222 show record memory-query
4223 Control whether to stop the inferior if memory changes caused
4224 by an instruction cannot be recorded.
4229 The disassemble command now supports "start,+length" form of two arguments.
4233 ** GDB now provides a new directory location, called the python directory,
4234 where Python scripts written for GDB can be installed. The location
4235 of that directory is <data-directory>/python, where <data-directory>
4236 is the GDB data directory. For more details, see section `Scripting
4237 GDB using Python' in the manual.
4239 ** The GDB Python API now has access to breakpoints, symbols, symbol
4240 tables, program spaces, inferiors, threads and frame's code blocks.
4241 Additionally, GDB Parameters can now be created from the API, and
4242 manipulated via set/show in the CLI.
4244 ** New functions gdb.target_charset, gdb.target_wide_charset,
4245 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4247 ** New exception gdb.GdbError.
4249 ** Pretty-printers are now also looked up in the current program space.
4251 ** Pretty-printers can now be individually enabled and disabled.
4253 ** GDB now looks for names of Python scripts to auto-load in a
4254 special section named `.debug_gdb_scripts', in addition to looking
4255 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4257 * Tracepoint actions were unified with breakpoint commands. In particular,
4258 there are no longer differences in "info break" output for breakpoints and
4259 tracepoints and the "commands" command can be used for both tracepoints and
4260 regular breakpoints.
4264 ARM Symbian arm*-*-symbianelf*
4266 * D language support.
4267 GDB now supports debugging programs written in the D programming
4270 * GDB now supports the extended ptrace interface for PowerPC which is
4271 available since Linux kernel version 2.6.34. This automatically enables
4272 any hardware breakpoints and additional hardware watchpoints available in
4273 the processor. The old ptrace interface exposes just one hardware
4274 watchpoint and no hardware breakpoints.
4276 * GDB is now able to use the Data Value Compare (DVC) register available on
4277 embedded PowerPC processors to implement in hardware simple watchpoint
4278 conditions of the form:
4280 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4282 This works in native GDB running on Linux kernels with the extended ptrace
4283 interface mentioned above.
4285 *** Changes in GDB 7.1
4289 ** Namespace Support
4291 GDB now supports importing of namespaces in C++. This enables the
4292 user to inspect variables from imported namespaces. Support for
4293 namepace aliasing has also been added. So, if a namespace is
4294 aliased in the current scope (e.g. namepace C=A; ) the user can
4295 print variables using the alias (e.g. (gdb) print C::x).
4299 All known bugs relating to the printing of virtual base class were
4300 fixed. It is now possible to call overloaded static methods using a
4305 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4306 and reinterpret_cast<> are now handled by the C++ expression parser.
4310 Xilinx MicroBlaze microblaze-*-*
4315 Xilinx MicroBlaze microblaze
4318 * Multi-program debugging.
4320 GDB now has support for multi-program (a.k.a. multi-executable or
4321 multi-exec) debugging. This allows for debugging multiple inferiors
4322 simultaneously each running a different program under the same GDB
4323 session. See "Debugging Multiple Inferiors and Programs" in the
4324 manual for more information. This implied some user visible changes
4325 in the multi-inferior support. For example, "info inferiors" now
4326 lists inferiors that are not running yet or that have exited
4327 already. See also "New commands" and "New options" below.
4329 * New tracing features
4331 GDB's tracepoint facility now includes several new features:
4333 ** Trace state variables
4335 GDB tracepoints now include support for trace state variables, which
4336 are variables managed by the target agent during a tracing
4337 experiment. They are useful for tracepoints that trigger each
4338 other, so for instance one tracepoint can count hits in a variable,
4339 and then a second tracepoint has a condition that is true when the
4340 count reaches a particular value. Trace state variables share the
4341 $-syntax of GDB convenience variables, and can appear in both
4342 tracepoint actions and condition expressions. Use the "tvariable"
4343 command to create, and "info tvariables" to view; see "Trace State
4344 Variables" in the manual for more detail.
4348 GDB now includes an option for defining fast tracepoints, which
4349 targets may implement more efficiently, such as by installing a jump
4350 into the target agent rather than a trap instruction. The resulting
4351 speedup can be by two orders of magnitude or more, although the
4352 tradeoff is that some program locations on some target architectures
4353 might not allow fast tracepoint installation, for instance if the
4354 instruction to be replaced is shorter than the jump. To request a
4355 fast tracepoint, use the "ftrace" command, with syntax identical to
4356 the regular trace command.
4358 ** Disconnected tracing
4360 It is now possible to detach GDB from the target while it is running
4361 a trace experiment, then reconnect later to see how the experiment
4362 is going. In addition, a new variable disconnected-tracing lets you
4363 tell the target agent whether to continue running a trace if the
4364 connection is lost unexpectedly.
4368 GDB now has the ability to save the trace buffer into a file, and
4369 then use that file as a target, similarly to you can do with
4370 corefiles. You can select trace frames, print data that was
4371 collected in them, and use tstatus to display the state of the
4372 tracing run at the moment that it was saved. To create a trace
4373 file, use "tsave <filename>", and to use it, do "target tfile
4376 ** Circular trace buffer
4378 You can ask the target agent to handle the trace buffer as a
4379 circular buffer, discarding the oldest trace frames to make room for
4380 newer ones, by setting circular-trace-buffer to on. This feature may
4381 not be available for all target agents.
4386 The disassemble command, when invoked with two arguments, now requires
4387 the arguments to be comma-separated.
4390 The info variables command now displays variable definitions. Files
4391 which only declare a variable are not shown.
4394 The source command is now capable of sourcing Python scripts.
4395 This feature is dependent on the debugger being build with Python
4398 Related to this enhancement is also the introduction of a new command
4399 "set script-extension" (see below).
4401 * New commands (for set/show, see "New options" below)
4403 record save [<FILENAME>]
4404 Save a file (in core file format) containing the process record
4405 execution log for replay debugging at a later time.
4407 record restore <FILENAME>
4408 Restore the process record execution log that was saved at an
4409 earlier time, for replay debugging.
4411 add-inferior [-copies <N>] [-exec <FILENAME>]
4414 clone-inferior [-copies <N>] [ID]
4415 Make a new inferior ready to execute the same program another
4416 inferior has loaded.
4421 maint info program-spaces
4422 List the program spaces loaded into GDB.
4424 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4425 show remote interrupt-sequence
4426 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4427 as the sequence to the remote target in order to interrupt the execution.
4428 Ctrl-C is a default. Some system prefers BREAK which is high level of
4429 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4430 Magic SysRq g. It is BREAK signal and character 'g'.
4432 set remote interrupt-on-connect [on | off]
4433 show remote interrupt-on-connect
4434 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4435 remote target when gdb connects to it. This is needed when you debug
4438 set remotebreak [on | off]
4440 Deprecated. Use "set/show remote interrupt-sequence" instead.
4442 tvariable $NAME [ = EXP ]
4443 Create or modify a trace state variable.
4446 List trace state variables and their values.
4448 delete tvariable $NAME ...
4449 Delete one or more trace state variables.
4452 Evaluate the given expressions without collecting anything into the
4453 trace buffer. (Valid in tracepoint actions only.)
4455 ftrace FN / FILE:LINE / *ADDR
4456 Define a fast tracepoint at the given function, line, or address.
4458 * New expression syntax
4460 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4461 GDB now parses 0b101010 identically with 42.
4465 set follow-exec-mode new|same
4466 show follow-exec-mode
4467 Control whether GDB reuses the same inferior across an exec call or
4468 creates a new one. This is useful to be able to restart the old
4469 executable after the inferior having done an exec call.
4471 set default-collect EXPR, ...
4472 show default-collect
4473 Define a list of expressions to be collected at each tracepoint.
4474 This is a useful way to ensure essential items are not overlooked,
4475 such as registers or a critical global variable.
4477 set disconnected-tracing
4478 show disconnected-tracing
4479 If set to 1, the target is instructed to continue tracing if it
4480 loses its connection to GDB. If 0, the target is to stop tracing
4483 set circular-trace-buffer
4484 show circular-trace-buffer
4485 If set to on, the target is instructed to use a circular trace buffer
4486 and discard the oldest trace frames instead of stopping the trace due
4487 to a full trace buffer. If set to off, the trace stops when the buffer
4488 fills up. Some targets may not support this.
4490 set script-extension off|soft|strict
4491 show script-extension
4492 If set to "off", the debugger does not perform any script language
4493 recognition, and all sourced files are assumed to be GDB scripts.
4494 If set to "soft" (the default), files are sourced according to
4495 filename extension, falling back to GDB scripts if the first
4497 If set to "strict", files are sourced according to filename extension.
4499 set ada trust-PAD-over-XVS on|off
4500 show ada trust-PAD-over-XVS
4501 If off, activate a workaround against a bug in the debugging information
4502 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4503 the GCC sources for more information about the GNAT encoding and
4504 PAD types in particular). It is always safe to set this option to
4505 off, but this introduces a slight performance penalty. The default
4508 * Python API Improvements
4510 ** GDB provides the new class gdb.LazyString. This is useful in
4511 some pretty-printing cases. The new method gdb.Value.lazy_string
4512 provides a simple way to create objects of this type.
4514 ** The fields returned by gdb.Type.fields now have an
4515 `is_base_class' attribute.
4517 ** The new method gdb.Type.range returns the range of an array type.
4519 ** The new method gdb.parse_and_eval can be used to parse and
4520 evaluate an expression.
4522 * New remote packets
4525 Define a trace state variable.
4528 Get the current value of a trace state variable.
4531 Set desired tracing behavior upon disconnection.
4534 Set the trace buffer to be linear or circular.
4537 Get data about the tracepoints currently in use.
4541 Process record now works correctly with hardware watchpoints.
4543 Multiple bug fixes have been made to the mips-irix port, making it
4544 much more reliable. In particular:
4545 - Debugging threaded applications is now possible again. Previously,
4546 GDB would hang while starting the program, or while waiting for
4547 the program to stop at a breakpoint.
4548 - Attaching to a running process no longer hangs.
4549 - An error occurring while loading a core file has been fixed.
4550 - Changing the value of the PC register now works again. This fixes
4551 problems observed when using the "jump" command, or when calling
4552 a function from GDB, or even when assigning a new value to $pc.
4553 - With the "finish" and "return" commands, the return value for functions
4554 returning a small array is now correctly printed.
4555 - It is now possible to break on shared library code which gets executed
4556 during a shared library init phase (code executed while executing
4557 their .init section). Previously, the breakpoint would have no effect.
4558 - GDB is now able to backtrace through the signal handler for
4559 non-threaded programs.
4561 PIE (Position Independent Executable) programs debugging is now supported.
4562 This includes debugging execution of PIC (Position Independent Code) shared
4563 libraries although for that, it should be possible to run such libraries as an
4566 *** Changes in GDB 7.0
4568 * GDB now has an interface for JIT compilation. Applications that
4569 dynamically generate code can create symbol files in memory and register
4570 them with GDB. For users, the feature should work transparently, and
4571 for JIT developers, the interface is documented in the GDB manual in the
4572 "JIT Compilation Interface" chapter.
4574 * Tracepoints may now be conditional. The syntax is as for
4575 breakpoints; either an "if" clause appended to the "trace" command,
4576 or the "condition" command is available. GDB sends the condition to
4577 the target for evaluation using the same bytecode format as is used
4578 for tracepoint actions.
4580 * The disassemble command now supports: an optional /r modifier, print the
4581 raw instructions in hex as well as in symbolic form, and an optional /m
4582 modifier to print mixed source+assembly.
4584 * Process record and replay
4586 In a architecture environment that supports ``process record and
4587 replay'', ``process record and replay'' target can record a log of
4588 the process execution, and replay it with both forward and reverse
4591 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4592 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4593 set execution-direction {forward|reverse}, for targets that support
4596 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4597 feature is available with a native GDB running on kernel version
4600 * GDB now has support for multi-byte and wide character sets on the
4601 target. Strings whose character type is wchar_t, char16_t, or
4602 char32_t are now correctly printed. GDB supports wide- and unicode-
4603 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4604 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4605 `printf'. This feature requires iconv to work properly; if your
4606 system does not have a working iconv, GDB can use GNU libiconv. See
4607 the installation instructions for more information.
4609 * GDB now supports automatic retrieval of shared library files from
4610 remote targets. To use this feature, specify a system root that begins
4611 with the `remote:' prefix, either via the `set sysroot' command or via
4612 the `--with-sysroot' configure-time option.
4614 * "info sharedlibrary" now takes an optional regex of libraries to show,
4615 and it now reports if a shared library has no debugging information.
4617 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4618 now complete on file names.
4620 * When completing in expressions, gdb will attempt to limit
4621 completions to allowable structure or union fields, where appropriate.
4622 For instance, consider:
4624 # struct example { int f1; double f2; };
4625 # struct example variable;
4628 If the user types TAB at the end of this command line, the available
4629 completions will be "f1" and "f2".
4631 * Inlined functions are now supported. They show up in backtraces, and
4632 the "step", "next", and "finish" commands handle them automatically.
4634 * GDB now supports the token-splicing (##) and stringification (#)
4635 operators when expanding macros. It also supports variable-arity
4638 * GDB now supports inspecting extra signal information, exported by
4639 the new $_siginfo convenience variable. The feature is currently
4640 implemented on linux ARM, i386 and amd64.
4642 * GDB can now display the VFP floating point registers and NEON vector
4643 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4644 can provide these registers (requires Linux 2.6.30 or later). Remote
4645 and simulator targets may also provide them.
4647 * New remote packets
4650 Search memory for a sequence of bytes.
4653 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4654 operation over reliable transport links. Use of this packet is
4655 controlled by the `set remote noack-packet' command.
4658 Kill the process with the specified process ID. Use this in preference
4659 to `k' when multiprocess protocol extensions are supported.
4662 Obtains additional operating system information
4666 Read or write additional signal information.
4668 * Removed remote protocol undocumented extension
4670 An undocumented extension to the remote protocol's `S' stop reply
4671 packet that permitted the stub to pass a process id was removed.
4672 Remote servers should use the `T' stop reply packet instead.
4674 * GDB now supports multiple function calling conventions according to the
4675 DWARF-2 DW_AT_calling_convention function attribute.
4677 * The SH target utilizes the aforementioned change to distinguish between gcc
4678 and Renesas calling convention. It also adds the new CLI commands
4679 `set/show sh calling-convention'.
4681 * GDB can now read compressed debug sections, as produced by GNU gold
4682 with the --compress-debug-sections=zlib flag.
4684 * 64-bit core files are now supported on AIX.
4686 * Thread switching is now supported on Tru64.
4688 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4689 which will be allocated using malloc later in program execution.
4691 * The qXfer:libraries:read remote protocol packet now allows passing a
4692 list of section offsets.
4694 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4695 conditions handling signals delivered during attach or thread creation
4696 have also been fixed.
4698 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4699 From the user's standpoint, all unqualified instances of True and False
4700 are treated as the standard definitions, regardless of context.
4702 * GDB now parses C++ symbol and type names more flexibly. For
4705 template<typename T> class C { };
4708 GDB will now correctly handle all of:
4710 ptype C<char const *>
4711 ptype C<char const*>
4712 ptype C<const char *>
4713 ptype C<const char*>
4715 * New features in the GDB remote stub, gdbserver
4717 - The "--wrapper" command-line argument tells gdbserver to use a
4718 wrapper program to launch programs for debugging.
4720 - On PowerPC and S/390 targets, it is now possible to use a single
4721 gdbserver executable to debug both 32-bit and 64-bit programs.
4722 (This requires gdbserver itself to be built as a 64-bit executable.)
4724 - gdbserver uses the new noack protocol mode for TCP connections to
4725 reduce communications latency, if also supported and enabled in GDB.
4727 - Support for the sparc64-linux-gnu target is now included in
4730 - The amd64-linux build of gdbserver now supports debugging both
4731 32-bit and 64-bit programs.
4733 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4734 now support hardware watchpoints, and will use them automatically
4739 GDB now has support for scripting using Python. Whether this is
4740 available is determined at configure time.
4742 New GDB commands can now be written in Python.
4744 * Ada tasking support
4746 Ada tasks can now be inspected in GDB. The following commands have
4750 Print the list of Ada tasks.
4752 Print detailed information about task number N.
4754 Print the task number of the current task.
4756 Switch the context of debugging to task number N.
4758 * Support for user-defined prefixed commands. The "define" command can
4759 add new commands to existing prefixes, e.g. "target".
4761 * Multi-inferior, multi-process debugging.
4763 GDB now has generalized support for multi-inferior debugging. See
4764 "Debugging Multiple Inferiors" in the manual for more information.
4765 Although availability still depends on target support, the command
4766 set is more uniform now. The GNU/Linux specific multi-forks support
4767 has been migrated to this new framework. This implied some user
4768 visible changes; see "New commands" and also "Removed commands"
4771 * Target descriptions can now describe the target OS ABI. See the
4772 "Target Description Format" section in the user manual for more
4775 * Target descriptions can now describe "compatible" architectures
4776 to indicate that the target can execute applications for a different
4777 architecture in addition to those for the main target architecture.
4778 See the "Target Description Format" section in the user manual for
4781 * Multi-architecture debugging.
4783 GDB now includes general supports for debugging applications on
4784 hybrid systems that use more than one single processor architecture
4785 at the same time. Each such hybrid architecture still requires
4786 specific support to be added. The only hybrid architecture supported
4787 in this version of GDB is the Cell Broadband Engine.
4789 * GDB now supports integrated debugging of Cell/B.E. applications that
4790 use both the PPU and SPU architectures. To enable support for hybrid
4791 Cell/B.E. debugging, you need to configure GDB to support both the
4792 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4793 --enable-targets configure option.
4795 * Non-stop mode debugging.
4797 For some targets, GDB now supports an optional mode of operation in
4798 which you can examine stopped threads while other threads continue
4799 to execute freely. This is referred to as non-stop mode, with the
4800 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4801 section in the user manual for more information.
4803 To be able to support remote non-stop debugging, a remote stub needs
4804 to implement the non-stop mode remote protocol extensions, as
4805 described in the "Remote Non-Stop" section of the user manual. The
4806 GDB remote stub, gdbserver, has been adjusted to support these
4807 extensions on linux targets.
4809 * New commands (for set/show, see "New options" below)
4811 catch syscall [NAME(S) | NUMBER(S)]
4812 Catch system calls. Arguments, which should be names of system
4813 calls or their numbers, mean catch only those syscalls. Without
4814 arguments, every syscall will be caught. When the inferior issues
4815 any of the specified syscalls, GDB will stop and announce the system
4816 call, both when it is called and when its call returns. This
4817 feature is currently available with a native GDB running on the
4818 Linux Kernel, under the following architectures: x86, x86_64,
4819 PowerPC and PowerPC64.
4821 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4823 Search memory for a sequence of bytes.
4825 maint set python print-stack
4826 maint show python print-stack
4827 Show a stack trace when an error is encountered in a Python script.
4830 Invoke CODE by passing it to the Python interpreter.
4835 These allow macros to be defined, undefined, and listed
4839 Show operating system information about processes.
4842 List the inferiors currently under GDB's control.
4845 Switch focus to inferior number NUM.
4848 Detach from inferior number NUM.
4851 Kill inferior number NUM.
4855 set spu stop-on-load
4856 show spu stop-on-load
4857 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4859 set spu auto-flush-cache
4860 show spu auto-flush-cache
4861 Control whether to automatically flush the software-managed cache
4862 during Cell/B.E. debugging.
4864 set sh calling-convention
4865 show sh calling-convention
4866 Control the calling convention used when calling SH target functions.
4869 show debug timestamp
4870 Control display of timestamps with GDB debugging output.
4872 set disassemble-next-line
4873 show disassemble-next-line
4874 Control display of disassembled source lines or instructions when
4877 set remote noack-packet
4878 show remote noack-packet
4879 Set/show the use of remote protocol QStartNoAckMode packet. See above
4880 under "New remote packets."
4882 set remote query-attached-packet
4883 show remote query-attached-packet
4884 Control use of remote protocol `qAttached' (query-attached) packet.
4886 set remote read-siginfo-object
4887 show remote read-siginfo-object
4888 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4891 set remote write-siginfo-object
4892 show remote write-siginfo-object
4893 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4896 set remote reverse-continue
4897 show remote reverse-continue
4898 Control use of remote protocol 'bc' (reverse-continue) packet.
4900 set remote reverse-step
4901 show remote reverse-step
4902 Control use of remote protocol 'bs' (reverse-step) packet.
4904 set displaced-stepping
4905 show displaced-stepping
4906 Control displaced stepping mode. Displaced stepping is a way to
4907 single-step over breakpoints without removing them from the debuggee.
4908 Also known as "out-of-line single-stepping".
4911 show debug displaced
4912 Control display of debugging info for displaced stepping.
4914 maint set internal-error
4915 maint show internal-error
4916 Control what GDB does when an internal error is detected.
4918 maint set internal-warning
4919 maint show internal-warning
4920 Control what GDB does when an internal warning is detected.
4925 Use a wrapper program to launch programs for debugging.
4927 set multiple-symbols (all|ask|cancel)
4928 show multiple-symbols
4929 The value of this variable can be changed to adjust the debugger behavior
4930 when an expression or a breakpoint location contains an ambiguous symbol
4931 name (an overloaded function name, for instance).
4933 set breakpoint always-inserted
4934 show breakpoint always-inserted
4935 Keep breakpoints always inserted in the target, as opposed to inserting
4936 them when resuming the target, and removing them when the target stops.
4937 This option can improve debugger performance on slow remote targets.
4939 set arm fallback-mode (arm|thumb|auto)
4940 show arm fallback-mode
4941 set arm force-mode (arm|thumb|auto)
4943 These commands control how ARM GDB determines whether instructions
4944 are ARM or Thumb. The default for both settings is auto, which uses
4945 the current CPSR value for instructions without symbols; previous
4946 versions of GDB behaved as if "set arm fallback-mode arm".
4948 set disable-randomization
4949 show disable-randomization
4950 Standalone programs run with the virtual address space randomization enabled
4951 by default on some platforms. This option keeps the addresses stable across
4952 multiple debugging sessions.
4956 Control whether other threads are stopped or not when some thread hits
4961 Requests that asynchronous execution is enabled in the target, if available.
4962 In this case, it's possible to resume target in the background, and interact
4963 with GDB while the target is running. "show target-async" displays the
4964 current state of asynchronous execution of the target.
4966 set target-wide-charset
4967 show target-wide-charset
4968 The target-wide-charset is the name of the character set that GDB
4969 uses when printing characters whose type is wchar_t.
4971 set tcp auto-retry (on|off)
4973 set tcp connect-timeout
4974 show tcp connect-timeout
4975 These commands allow GDB to retry failed TCP connections to a remote stub
4976 with a specified timeout period; this is useful if the stub is launched
4977 in parallel with GDB but may not be ready to accept connections immediately.
4979 set libthread-db-search-path
4980 show libthread-db-search-path
4981 Control list of directories which GDB will search for appropriate
4984 set schedule-multiple (on|off)
4985 show schedule-multiple
4986 Allow GDB to resume all threads of all processes or only threads of
4987 the current process.
4991 Use more aggressive caching for accesses to the stack. This improves
4992 performance of remote debugging (particularly backtraces) without
4993 affecting correctness.
4995 set interactive-mode (on|off|auto)
4996 show interactive-mode
4997 Control whether GDB runs in interactive mode (on) or not (off).
4998 When in interactive mode, GDB waits for the user to answer all
4999 queries. Otherwise, GDB does not wait and assumes the default
5000 answer. When set to auto (the default), GDB determines which
5001 mode to use based on the stdin settings.
5006 For program forks, this is replaced by the new more generic `info
5007 inferiors' command. To list checkpoints, you can still use the
5008 `info checkpoints' command, which was an alias for the `info forks'
5012 Replaced by the new `inferior' command. To switch between
5013 checkpoints, you can still use the `restart' command, which was an
5014 alias for the `fork' command.
5017 This is removed, since some targets don't have a notion of
5018 processes. To switch between processes, you can still use the
5019 `inferior' command using GDB's own inferior number.
5022 For program forks, this is replaced by the new more generic `kill
5023 inferior' command. To delete a checkpoint, you can still use the
5024 `delete checkpoint' command, which was an alias for the `delete
5028 For program forks, this is replaced by the new more generic `detach
5029 inferior' command. To detach a checkpoint, you can still use the
5030 `detach checkpoint' command, which was an alias for the `detach
5033 * New native configurations
5035 x86/x86_64 Darwin i[34567]86-*-darwin*
5037 x86_64 MinGW x86_64-*-mingw*
5041 Lattice Mico32 lm32-*
5042 x86 DICOS i[34567]86-*-dicos*
5043 x86_64 DICOS x86_64-*-dicos*
5046 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5047 (mingw32ce) debugging.
5053 These commands were actually not implemented on any target.
5055 *** Changes in GDB 6.8
5057 * New native configurations
5059 NetBSD/hppa hppa*-*netbsd*
5060 Xtensa GNU/Linux xtensa*-*-linux*
5064 NetBSD/hppa hppa*-*-netbsd*
5065 Xtensa GNU/Linux xtensa*-*-linux*
5067 * Change in command line behavior -- corefiles vs. process ids.
5069 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5070 attaching to process NUMBER fails, GDB no longer attempts to open a
5071 core file named NUMBER. Attaching to a program using the -c option
5072 is no longer supported. Instead, use the '-p' or '--pid' options.
5074 * GDB can now be built as a native debugger for debugging Windows x86
5075 (mingw32) Portable Executable (PE) programs.
5077 * Pending breakpoints no longer change their number when their address
5080 * GDB now supports breakpoints with multiple locations,
5081 including breakpoints on C++ constructors, inside C++ templates,
5082 and in inlined functions.
5084 * GDB's ability to debug optimized code has been improved. GDB more
5085 accurately identifies function bodies and lexical blocks that occupy
5086 more than one contiguous range of addresses.
5088 * Target descriptions can now describe registers for PowerPC.
5090 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5091 registers on PowerPC targets.
5093 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5094 targets even when the libthread_db library is not available.
5096 * The GDB remote stub, gdbserver, now supports the new file transfer
5097 commands (remote put, remote get, and remote delete).
5099 * The GDB remote stub, gdbserver, now supports run and attach in
5100 extended-remote mode.
5102 * hppa*64*-*-hpux11* target broken
5103 The debugger is unable to start a program and fails with the following
5104 error: "Error trying to get information about dynamic linker".
5105 The gdb-6.7 release is also affected.
5107 * GDB now supports the --enable-targets= configure option to allow
5108 building a single GDB executable that supports multiple remote
5109 target architectures.
5111 * GDB now supports debugging C and C++ programs which use the
5112 Decimal Floating Point extension. In addition, the PowerPC target
5113 now has a set of pseudo-registers to inspect decimal float values
5114 stored in two consecutive float registers.
5116 * The -break-insert MI command can optionally create pending
5119 * Improved support for debugging Ada
5120 Many improvements to the Ada language support have been made. These
5122 - Better support for Ada2005 interface types
5123 - Improved handling of arrays and slices in general
5124 - Better support for Taft-amendment types
5125 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5127 - Improved command completion in Ada
5130 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5135 set print frame-arguments (all|scalars|none)
5136 show print frame-arguments
5137 The value of this variable can be changed to control which argument
5138 values should be printed by the debugger when displaying a frame.
5143 Transfer files to and from a remote target, and delete remote files.
5150 Transfer files to and from a remote target, and delete remote files.
5152 * New remote packets
5159 Open, close, read, write, and delete files on the remote system.
5162 Attach to an existing process on the remote system, in extended-remote
5166 Run a new process on the remote system, in extended-remote mode.
5168 *** Changes in GDB 6.7
5170 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5171 bfd, libiberty and opcodes, as revealed by static analysis donated by
5172 Coverity, Inc. (http://scan.coverity.com).
5174 * When looking up multiply-defined global symbols, GDB will now prefer the
5175 symbol definition in the current shared library if it was built using the
5176 -Bsymbolic linker option.
5178 * When the Text User Interface (TUI) is not configured, GDB will now
5179 recognize the -tui command-line option and print a message that the TUI
5182 * The GDB remote stub, gdbserver, now has lower overhead for high
5183 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5185 * GDB for MIPS targets now autodetects whether a remote target provides
5186 32-bit or 64-bit register values.
5188 * Support for C++ member pointers has been improved.
5190 * GDB now understands XML target descriptions, which specify the
5191 target's overall architecture. GDB can read a description from
5192 a local file or over the remote serial protocol.
5194 * Vectors of single-byte data use a new integer type which is not
5195 automatically displayed as character or string data.
5197 * The /s format now works with the print command. It displays
5198 arrays of single-byte integers and pointers to single-byte integers
5201 * Target descriptions can now describe target-specific registers,
5202 for architectures which have implemented the support (currently
5203 only ARM, M68K, and MIPS).
5205 * GDB and the GDB remote stub, gdbserver, now support the XScale
5208 * The GDB remote stub, gdbserver, has been updated to support
5209 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5210 has been rewritten to use the standard GDB remote protocol.
5212 * GDB can now step into C++ functions which are called through thunks.
5214 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5216 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5217 layout. It also supports a TextSeg= and DataSeg= response when only
5218 segment base addresses (rather than offsets) are available.
5220 * The /i format now outputs any trailing branch delay slot instructions
5221 immediately following the last instruction within the count specified.
5223 * The GDB remote protocol "T" stop reply packet now supports a
5224 "library" response. Combined with the new "qXfer:libraries:read"
5225 packet, this response allows GDB to debug shared libraries on targets
5226 where the operating system manages the list of loaded libraries (e.g.
5227 Windows and SymbianOS).
5229 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5230 (DLLs) on Windows and Windows CE targets.
5232 * GDB now supports a faster verification that a .debug file matches its binary
5233 according to its build-id signature, if the signature is present.
5239 Enable or disable hardware flow control (RTS/CTS) on the serial port
5240 when debugging using remote targets.
5242 set mem inaccessible-by-default
5243 show mem inaccessible-by-default
5244 If the target supplies a memory map, for instance via the remote
5245 protocol's "qXfer:memory-map:read" packet, setting this variable
5246 prevents GDB from accessing memory outside the memory map. This
5247 is useful for targets with memory mapped registers or which react
5248 badly to accesses of unmapped address space.
5250 set breakpoint auto-hw
5251 show breakpoint auto-hw
5252 If the target supplies a memory map, for instance via the remote
5253 protocol's "qXfer:memory-map:read" packet, setting this variable
5254 lets GDB use hardware breakpoints automatically for memory regions
5255 where it can not use software breakpoints. This covers both the
5256 "break" command and internal breakpoints used for other commands
5257 including "next" and "finish".
5260 catch exception unhandled
5261 Stop the program execution when Ada exceptions are raised.
5264 Stop the program execution when an Ada assertion failed.
5268 Set an alternate system root for target files. This is a more
5269 general version of "set solib-absolute-prefix", which is now
5270 an alias to "set sysroot".
5273 Provide extended SPU facility status information. This set of
5274 commands is available only when debugging the Cell/B.E. SPU
5277 * New native configurations
5279 OpenBSD/sh sh*-*openbsd*
5282 unset tdesc filename
5284 Use the specified local file as an XML target description, and do
5285 not query the target for its built-in description.
5289 OpenBSD/sh sh*-*-openbsd*
5290 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5291 Toshiba Media Processor mep-elf
5293 * New remote packets
5296 Ignore the specified signals; pass them directly to the debugged program
5297 without stopping other threads or reporting them to GDB.
5299 qXfer:features:read:
5300 Read an XML target description from the target, which describes its
5305 Read or write contents of an spufs file on the target system. These
5306 packets are available only on the Cell/B.E. SPU architecture.
5308 qXfer:libraries:read:
5309 Report the loaded shared libraries. Combined with new "T" packet
5310 response, this packet allows GDB to debug shared libraries on
5311 targets where the operating system manages the list of loaded
5312 libraries (e.g. Windows and SymbianOS).
5316 Support for these obsolete configurations has been removed.
5324 i[34567]86-*-lynxos*
5325 i[34567]86-*-netware*
5326 i[34567]86-*-sco3.2v5*
5327 i[34567]86-*-sco3.2v4*
5329 i[34567]86-*-sysv4.2*
5332 i[34567]86-*-unixware2*
5333 i[34567]86-*-unixware*
5342 * Other removed features
5349 Various m68k-only ROM monitors.
5356 Various Renesas ROM monitors and debugging interfaces for SH and
5361 Support for a Macraigor serial interface to on-chip debugging.
5362 GDB does not directly support the newer parallel or USB
5367 A debug information format. The predecessor to DWARF 2 and
5368 DWARF 3, which are still supported.
5370 Support for the HP aCC compiler on HP-UX/PA-RISC
5372 SOM-encapsulated symbolic debugging information, automatic
5373 invocation of pxdb, and the aCC custom C++ ABI. This does not
5374 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5375 with aCC can still be debugged on an assembly level.
5377 MIPS ".pdr" sections
5379 A MIPS-specific format used to describe stack frame layout
5380 in debugging information.
5384 GDB could work with an older version of Guile to debug
5385 the interpreter and Scheme programs running in it.
5387 set mips stack-arg-size
5388 set mips saved-gpreg-size
5390 Use "set mips abi" to control parameter passing for MIPS.
5392 *** Changes in GDB 6.6
5397 Cell Broadband Engine SPU spu-elf
5399 * GDB can now be configured as a cross-debugger targeting native Windows
5400 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5401 running on a Windows system over TCP/IP to debug Windows programs.
5403 * The GDB remote stub, gdbserver, has been updated to support Windows and
5404 Cygwin debugging. Both single-threaded and multi-threaded programs are
5407 * The "set trust-readonly-sections" command works again. This command was
5408 broken in GDB 6.3, 6.4, and 6.5.
5410 * The "load" command now supports writing to flash memory, if the remote
5411 stub provides the required support.
5413 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5414 longer requires symbolic debug information (e.g. DWARF-2).
5419 unset substitute-path
5420 show substitute-path
5421 Manage a list of substitution rules that GDB uses to rewrite the name
5422 of the directories where the sources are located. This can be useful
5423 for instance when the sources were moved to a different location
5424 between compilation and debugging.
5428 Print each CLI command as it is executed. Each command is prefixed with
5429 a number of `+' symbols representing the nesting depth.
5430 The source command now has a `-v' option to enable the same feature.
5434 The ARM Demon monitor support (RDP protocol, "target rdp").
5436 Kernel Object Display, an embedded debugging feature which only worked with
5437 an obsolete version of Cisco IOS.
5439 The 'set download-write-size' and 'show download-write-size' commands.
5441 * New remote packets
5444 Tell a stub about GDB client features, and request remote target features.
5445 The first feature implemented is PacketSize, which allows the target to
5446 specify the size of packets it can handle - to minimize the number of
5447 packets required and improve performance when connected to a remote
5451 Fetch an OS auxilliary vector from the remote stub. This packet is a
5452 more efficient replacement for qPart:auxv:read.
5454 qXfer:memory-map:read:
5455 Fetch a memory map from the remote stub, including information about
5456 RAM, ROM, and flash memory devices.
5461 Erase and program a flash memory device.
5463 * Removed remote packets
5466 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5467 used it, and only gdbserver implemented it.
5469 *** Changes in GDB 6.5
5473 Renesas M32C/M16C m32c-elf
5475 Morpho Technologies ms1 ms1-elf
5479 init-if-undefined Initialize a convenience variable, but
5480 only if it doesn't already have a value.
5482 The following commands are presently only implemented for native GNU/Linux:
5484 checkpoint Save a snapshot of the program state.
5486 restart <n> Return the program state to a
5487 previously saved state.
5489 info checkpoints List currently saved checkpoints.
5491 delete-checkpoint <n> Delete a previously saved checkpoint.
5493 set|show detach-on-fork Tell gdb whether to detach from a newly
5494 forked process, or to keep debugging it.
5496 info forks List forks of the user program that
5497 are available to be debugged.
5499 fork <n> Switch to debugging one of several
5500 forks of the user program that are
5501 available to be debugged.
5503 delete-fork <n> Delete a fork from the list of forks
5504 that are available to be debugged (and
5505 kill the forked process).
5507 detach-fork <n> Delete a fork from the list of forks
5508 that are available to be debugged (and
5509 allow the process to continue).
5513 Morpho Technologies ms2 ms1-elf
5515 * Improved Windows host support
5517 GDB now builds as a cross debugger hosted on i686-mingw32, including
5518 native console support, and remote communications using either
5519 network sockets or serial ports.
5521 * Improved Modula-2 language support
5523 GDB can now print most types in the Modula-2 syntax. This includes:
5524 basic types, set types, record types, enumerated types, range types,
5525 pointer types and ARRAY types. Procedure var parameters are correctly
5526 printed and hexadecimal addresses and character constants are also
5527 written in the Modula-2 syntax. Best results can be obtained by using
5528 GNU Modula-2 together with the -gdwarf-2 command line option.
5532 The ARM rdi-share module.
5534 The Netware NLM debug server.
5536 *** Changes in GDB 6.4
5538 * New native configurations
5540 OpenBSD/arm arm*-*-openbsd*
5541 OpenBSD/mips64 mips64-*-openbsd*
5545 Morpho Technologies ms1 ms1-elf
5547 * New command line options
5549 --batch-silent As for --batch, but totally silent.
5550 --return-child-result The debugger will exist with the same value
5551 the child (debugged) program exited with.
5552 --eval-command COMMAND, -ex COMMAND
5553 Execute a single GDB CLI command. This may be
5554 specified multiple times and in conjunction
5555 with the --command (-x) option.
5557 * Deprecated commands removed
5559 The following commands, that were deprecated in 2000, have been
5563 set|show arm disassembly-flavor set|show arm disassembler
5564 othernames set arm disassembler
5565 set|show remotedebug set|show debug remote
5566 set|show archdebug set|show debug arch
5567 set|show eventdebug set|show debug event
5570 * New BSD user-level threads support
5572 It is now possible to debug programs using the user-level threads
5573 library on OpenBSD and FreeBSD. Currently supported (target)
5576 FreeBSD/amd64 x86_64-*-freebsd*
5577 FreeBSD/i386 i386-*-freebsd*
5578 OpenBSD/i386 i386-*-openbsd*
5580 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5581 are not yet supported.
5583 * New support for Matsushita MN10300 w/sim added
5584 (Work in progress). mn10300-elf.
5586 * REMOVED configurations and files
5588 VxWorks and the XDR protocol *-*-vxworks
5589 Motorola MCORE mcore-*-*
5590 National Semiconductor NS32000 ns32k-*-*
5592 * New "set print array-indexes" command
5594 After turning this setting "on", GDB prints the index of each element
5595 when displaying arrays. The default is "off" to preserve the previous
5598 * VAX floating point support
5600 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5602 * User-defined command support
5604 In addition to using $arg0..$arg9 for argument passing, it is now possible
5605 to use $argc to determine now many arguments have been passed. See the
5606 section on user-defined commands in the user manual for more information.
5608 *** Changes in GDB 6.3:
5610 * New command line option
5612 GDB now accepts -l followed by a number to set the timeout for remote
5615 * GDB works with GCC -feliminate-dwarf2-dups
5617 GDB now supports a more compact representation of DWARF-2 debug
5618 information using DW_FORM_ref_addr references. These are produced
5619 by GCC with the option -feliminate-dwarf2-dups and also by some
5620 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5621 to use -feliminate-dwarf2-dups.
5623 * Internationalization
5625 When supported by the host system, GDB will be built with
5626 internationalization (libintl). The task of marking up the sources is
5627 continued, we're looking forward to our first translation.
5631 Initial support for debugging programs compiled with the GNAT
5632 implementation of the Ada programming language has been integrated
5633 into GDB. In this release, support is limited to expression evaluation.
5635 * New native configurations
5637 GNU/Linux/m32r m32r-*-linux-gnu
5641 GDB's remote protocol now includes support for the 'p' packet. This
5642 packet is used to fetch individual registers from a remote inferior.
5644 * END-OF-LIFE registers[] compatibility module
5646 GDB's internal register infrastructure has been completely rewritten.
5647 The new infrastructure making possible the implementation of key new
5648 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5651 GDB 6.3 will be the last release to include the registers[]
5652 compatibility module that allowed out-of-date configurations to
5653 continue to work. This change directly impacts the following
5663 powerpc bdm protocol
5665 Unless there is activity to revive these configurations, they will be
5666 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5668 * OBSOLETE configurations and files
5670 Configurations that have been declared obsolete in this release have
5671 been commented out. Unless there is activity to revive these
5672 configurations, the next release of GDB will have their sources
5673 permanently REMOVED.
5682 *** Changes in GDB 6.2.1:
5684 * MIPS `break main; run' gave an heuristic-fence-post warning
5686 When attempting to run even a simple program, a warning about
5687 heuristic-fence-post being hit would be reported. This problem has
5690 * MIPS IRIX 'long double' crashed GDB
5692 When examining a long double variable, GDB would get a segmentation
5693 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5694 IRIX long double values).
5698 A bug in the VAX stack code was causing problems with the "next"
5699 command. This problem has been fixed.
5701 *** Changes in GDB 6.2:
5703 * Fix for ``many threads''
5705 On GNU/Linux systems that use the NPTL threads library, a program
5706 rapidly creating and deleting threads would confuse GDB leading to the
5709 ptrace: No such process.
5710 thread_db_get_info: cannot get thread info: generic error
5712 This problem has been fixed.
5714 * "-async" and "-noasync" options removed.
5716 Support for the broken "-noasync" option has been removed (it caused
5719 * New ``start'' command.
5721 This command runs the program until the beginning of the main procedure.
5723 * New BSD Kernel Data Access Library (libkvm) interface
5725 Using ``target kvm'' it is now possible to debug kernel core dumps and
5726 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5727 platforms. Currently supported (native-only) configurations are:
5729 FreeBSD/amd64 x86_64-*-freebsd*
5730 FreeBSD/i386 i?86-*-freebsd*
5731 NetBSD/i386 i?86-*-netbsd*
5732 NetBSD/m68k m68*-*-netbsd*
5733 NetBSD/sparc sparc-*-netbsd*
5734 OpenBSD/amd64 x86_64-*-openbsd*
5735 OpenBSD/i386 i?86-*-openbsd*
5736 OpenBSD/m68k m68*-openbsd*
5737 OpenBSD/sparc sparc-*-openbsd*
5739 * Signal trampoline code overhauled
5741 Many generic problems with GDB's signal handling code have been fixed.
5742 These include: backtraces through non-contiguous stacks; recognition
5743 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5744 call; backtrace through a signal trampoline; step into and out of
5745 signal handlers; and single-stepping in the signal trampoline.
5747 Please note that kernel bugs are a limiting factor here. These
5748 features have been shown to work on an s390 GNU/Linux system that
5749 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5751 * Cygwin support for DWARF 2 added.
5753 * New native configurations
5755 GNU/Linux/hppa hppa*-*-linux*
5756 OpenBSD/hppa hppa*-*-openbsd*
5757 OpenBSD/m68k m68*-*-openbsd*
5758 OpenBSD/m88k m88*-*-openbsd*
5759 OpenBSD/powerpc powerpc-*-openbsd*
5760 NetBSD/vax vax-*-netbsd*
5761 OpenBSD/vax vax-*-openbsd*
5763 * END-OF-LIFE frame compatibility module
5765 GDB's internal frame infrastructure has been completely rewritten.
5766 The new infrastructure making it possible to support key new features
5767 including DWARF 2 Call Frame Information. To aid in the task of
5768 migrating old configurations to this new infrastructure, a
5769 compatibility module, that allowed old configurations to continue to
5770 work, was also included.
5772 GDB 6.2 will be the last release to include this frame compatibility
5773 module. This change directly impacts the following configurations:
5783 Unless there is activity to revive these configurations, they will be
5784 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5786 * REMOVED configurations and files
5788 Sun 3, running SunOS 3 m68*-*-sunos3*
5789 Sun 3, running SunOS 4 m68*-*-sunos4*
5790 Sun 2, running SunOS 3 m68000-*-sunos3*
5791 Sun 2, running SunOS 4 m68000-*-sunos4*
5792 Motorola 680x0 running LynxOS m68*-*-lynxos*
5793 AT&T 3b1/Unix pc m68*-att-*
5794 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5795 decstation mips-dec-* mips-little-*
5796 riscos mips-*-riscos* mips-*-sysv*
5797 sonymips mips-sony-*
5798 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5800 *** Changes in GDB 6.1.1:
5802 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5804 The TUI (Text-mode User Interface) is now built as part of a default
5805 GDB configuration. It is enabled by either selecting the TUI with the
5806 command line option "-i=tui" or by running the separate "gdbtui"
5807 program. For more information on the TUI, see the manual "Debugging
5810 * Pending breakpoint support (also included in GDB 6.1)
5812 Support has been added to allow you to specify breakpoints in shared
5813 libraries that have not yet been loaded. If a breakpoint location
5814 cannot be found, and the "breakpoint pending" option is set to auto,
5815 GDB queries you if you wish to make the breakpoint pending on a future
5816 shared-library load. If and when GDB resolves the breakpoint symbol,
5817 the pending breakpoint is removed as one or more regular breakpoints
5820 Pending breakpoints are very useful for GCJ Java debugging.
5822 * Fixed ISO-C build problems
5824 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5825 non ISO-C code that stopped them being built using a more strict ISO-C
5826 compiler (e.g., IBM's C compiler).
5828 * Fixed build problem on IRIX 5
5830 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5831 wasn't able to compile compile on an IRIX 5 system.
5833 * Added execute permission to gdb/gdbserver/configure
5835 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5836 permission. This bug would cause configure to fail on a number of
5837 systems (Solaris, IRIX). Ref: server/519.
5839 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5841 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5842 has been updated to use constant array sizes.
5844 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5846 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5847 its generated DWARF Call Frame Info. This encoding was causing GDB to
5848 panic, that panic has been fixed. Ref: gdb/1628.
5850 * Fixed a problem when examining parameters in shared library code.
5852 When examining parameters in optimized shared library code generated
5853 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5854 not available''. GDB now correctly displays the variable's value.
5856 *** Changes in GDB 6.1:
5858 * Removed --with-mmalloc
5860 Support for the mmalloc memory manager has been removed, as it
5861 conflicted with the internal gdb byte cache.
5863 * Changes in AMD64 configurations
5865 The AMD64 target now includes the %cs and %ss registers. As a result
5866 the AMD64 remote protocol has changed; this affects the floating-point
5867 and SSE registers. If you rely on those registers for your debugging,
5868 you should upgrade gdbserver on the remote side.
5870 * Revised SPARC target
5872 The SPARC target has been completely revised, incorporating the
5873 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5874 support for LynxOS and SunOS 4 has been dropped. Calling functions
5875 from within GDB on operating systems with a non-executable stack
5876 (Solaris, OpenBSD) now works.
5880 GDB has a new C++ demangler which does a better job on the mangled
5881 names generated by current versions of g++. It also runs faster, so
5882 with this and other changes gdb should now start faster on large C++
5885 * DWARF 2 Location Expressions
5887 GDB support for location expressions has been extended to support function
5888 arguments and frame bases. Older versions of GDB could crash when they
5891 * C++ nested types and namespaces
5893 GDB's support for nested types and namespaces in C++ has been
5894 improved, especially if you use the DWARF 2 debugging format. (This
5895 is the default for recent versions of GCC on most platforms.)
5896 Specifically, if you have a class "Inner" defined within a class or
5897 namespace "Outer", then GDB realizes that the class's name is
5898 "Outer::Inner", not simply "Inner". This should greatly reduce the
5899 frequency of complaints about not finding RTTI symbols. In addition,
5900 if you are stopped at inside of a function defined within a namespace,
5901 GDB modifies its name lookup accordingly.
5903 * New native configurations
5905 NetBSD/amd64 x86_64-*-netbsd*
5906 OpenBSD/amd64 x86_64-*-openbsd*
5907 OpenBSD/alpha alpha*-*-openbsd*
5908 OpenBSD/sparc sparc-*-openbsd*
5909 OpenBSD/sparc64 sparc64-*-openbsd*
5911 * New debugging protocols
5913 M32R with SDI protocol m32r-*-elf*
5915 * "set prompt-escape-char" command deleted.
5917 The command "set prompt-escape-char" has been deleted. This command,
5918 and its very obscure effect on GDB's prompt, was never documented,
5919 tested, nor mentioned in the NEWS file.
5921 * OBSOLETE configurations and files
5923 Configurations that have been declared obsolete in this release have
5924 been commented out. Unless there is activity to revive these
5925 configurations, the next release of GDB will have their sources
5926 permanently REMOVED.
5928 Sun 3, running SunOS 3 m68*-*-sunos3*
5929 Sun 3, running SunOS 4 m68*-*-sunos4*
5930 Sun 2, running SunOS 3 m68000-*-sunos3*
5931 Sun 2, running SunOS 4 m68000-*-sunos4*
5932 Motorola 680x0 running LynxOS m68*-*-lynxos*
5933 AT&T 3b1/Unix pc m68*-att-*
5934 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5935 decstation mips-dec-* mips-little-*
5936 riscos mips-*-riscos* mips-*-sysv*
5937 sonymips mips-sony-*
5938 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5940 * REMOVED configurations and files
5942 SGI Irix-4.x mips-sgi-irix4 or iris4
5943 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5944 Z8000 simulator z8k-zilog-none or z8ksim
5945 Matsushita MN10200 w/simulator mn10200-*-*
5946 H8/500 simulator h8500-hitachi-hms or h8500hms
5947 HP/PA running BSD hppa*-*-bsd*
5948 HP/PA running OSF/1 hppa*-*-osf*
5949 HP/PA Pro target hppa*-*-pro*
5950 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5951 386BSD i[3456]86-*-bsd*
5952 Sequent family i[3456]86-sequent-sysv4*
5953 i[3456]86-sequent-sysv*
5954 i[3456]86-sequent-bsd*
5955 SPARC running LynxOS sparc-*-lynxos*
5956 SPARC running SunOS 4 sparc-*-sunos4*
5957 Tsqware Sparclet sparclet-*-*
5958 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5960 *** Changes in GDB 6.0:
5964 Support for debugging the Objective-C programming language has been
5965 integrated into GDB.
5967 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5969 DWARF 2's Call Frame Information makes available compiler generated
5970 information that more exactly describes the program's run-time stack.
5971 By using this information, GDB is able to provide more robust stack
5974 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5975 have been updated to use a new backtrace mechanism which includes
5976 DWARF 2 CFI support.
5980 GDB's remote protocol has been extended to include support for hosted
5981 file I/O (where the remote target uses GDB's file system). See GDB's
5982 remote protocol documentation for details.
5984 * All targets using the new architecture framework.
5986 All of GDB's targets have been updated to use the new internal
5987 architecture framework. The way is now open for future GDB releases
5988 to include cross-architecture native debugging support (i386 on amd64,
5991 * GNU/Linux's Thread Local Storage (TLS)
5993 GDB now includes support for for the GNU/Linux implementation of
5994 per-thread variables.
5996 * GNU/Linux's Native POSIX Thread Library (NPTL)
5998 GDB's thread code has been updated to work with either the new
5999 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6001 * Separate debug info.
6003 GDB, in conjunction with BINUTILS, now supports a mechanism for
6004 automatically loading debug information from a separate file. Instead
6005 of shipping full debug and non-debug versions of system libraries,
6006 system integrators can now instead ship just the stripped libraries
6007 and optional debug files.
6009 * DWARF 2 Location Expressions
6011 DWARF 2 Location Expressions allow the compiler to more completely
6012 describe the location of variables (even in optimized code) to the
6015 GDB now includes preliminary support for location expressions (support
6016 for DW_OP_piece is still missing).
6020 A number of long standing bugs that caused GDB to die while starting a
6021 Java application have been fixed. GDB's Java support is now
6022 considered "useable".
6024 * GNU/Linux support for fork, vfork, and exec.
6026 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6027 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6030 * GDB supports logging output to a file
6032 There are two new commands, "set logging" and "show logging", which can be
6033 used to capture GDB's output to a file.
6035 * The meaning of "detach" has changed for gdbserver
6037 The "detach" command will now resume the application, as documented. To
6038 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6041 * d10v, m68hc11 `regs' command deprecated
6043 The `info registers' command has been updated so that it displays the
6044 registers using a format identical to the old `regs' command.
6048 A new command, "maint set profile on/off", has been added. This command can
6049 be used to enable or disable profiling while running GDB, to profile a
6050 session or a set of commands. In addition there is a new configure switch,
6051 "--enable-profiling", which will cause GDB to be compiled with profiling
6052 data, for more informative profiling results.
6054 * Default MI syntax changed to "mi2".
6056 The default MI (machine interface) syntax, enabled by the command line
6057 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6058 "mi1", can be enabled by specifying the option "-i=mi1".
6060 Support for the original "mi0" syntax (included in GDB 5.0) has been
6063 Fix for gdb/192: removed extraneous space when displaying frame level.
6064 Fix for gdb/672: update changelist is now output in mi list format.
6065 Fix for gdb/702: a -var-assign that updates the value now shows up
6066 in a subsequent -var-update.
6068 * New native configurations.
6070 FreeBSD/amd64 x86_64-*-freebsd*
6072 * Multi-arched targets.
6074 HP/PA HPUX11 hppa*-*-hpux*
6075 Renesas M32R/D w/simulator m32r-*-elf*
6077 * OBSOLETE configurations and files
6079 Configurations that have been declared obsolete in this release have
6080 been commented out. Unless there is activity to revive these
6081 configurations, the next release of GDB will have their sources
6082 permanently REMOVED.
6084 Z8000 simulator z8k-zilog-none or z8ksim
6085 Matsushita MN10200 w/simulator mn10200-*-*
6086 H8/500 simulator h8500-hitachi-hms or h8500hms
6087 HP/PA running BSD hppa*-*-bsd*
6088 HP/PA running OSF/1 hppa*-*-osf*
6089 HP/PA Pro target hppa*-*-pro*
6090 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6091 Sequent family i[3456]86-sequent-sysv4*
6092 i[3456]86-sequent-sysv*
6093 i[3456]86-sequent-bsd*
6094 Tsqware Sparclet sparclet-*-*
6095 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6097 * REMOVED configurations and files
6100 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6101 IBM AIX PS/2 i[3456]86-*-aix
6102 i386 running Mach 3.0 i[3456]86-*-mach3*
6103 i386 running Mach i[3456]86-*-mach*
6104 i386 running OSF/1 i[3456]86-*osf1mk*
6105 HP/Apollo 68k Family m68*-apollo*-sysv*,
6107 m68*-hp-bsd*, m68*-hp-hpux*
6108 Argonaut Risc Chip (ARC) arc-*-*
6109 Mitsubishi D30V d30v-*-*
6110 Fujitsu FR30 fr30-*-elf*
6111 OS/9000 i[34]86-*-os9k
6112 I960 with MON960 i960-*-coff
6114 * MIPS $fp behavior changed
6116 The convenience variable $fp, for the MIPS, now consistently returns
6117 the address of the current frame's base. Previously, depending on the
6118 context, $fp could refer to either $sp or the current frame's base
6119 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6120 The GNU Source-Level Debugger''.
6122 *** Changes in GDB 5.3:
6124 * GNU/Linux shared library multi-threaded performance improved.
6126 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6127 `/proc', in preference to `ptrace' for memory reads. This may result
6128 in an improvement in the start-up time of multi-threaded, shared
6129 library applications when run under GDB. One GDB user writes: ``loads
6130 shared libs like mad''.
6132 * ``gdbserver'' now supports multi-threaded applications on some targets
6134 Support for debugging multi-threaded applications which use
6135 the GNU/Linux LinuxThreads package has been added for
6136 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6137 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6139 * GDB now supports C/C++ preprocessor macros.
6141 GDB now expands preprocessor macro invocations in C/C++ expressions,
6142 and provides various commands for showing macro definitions and how
6145 The new command `macro expand EXPRESSION' expands any macro
6146 invocations in expression, and shows the result.
6148 The new command `show macro MACRO-NAME' shows the definition of the
6149 macro named MACRO-NAME, and where it was defined.
6151 Most compilers don't include information about macros in the debugging
6152 information by default. In GCC 3.1, for example, you need to compile
6153 your program with the options `-gdwarf-2 -g3'. If the macro
6154 information is present in the executable, GDB will read it.
6156 * Multi-arched targets.
6158 DEC Alpha (partial) alpha*-*-*
6159 DEC VAX (partial) vax-*-*
6161 National Semiconductor NS32000 (partial) ns32k-*-*
6162 Motorola 68000 (partial) m68k-*-*
6163 Motorola MCORE mcore-*-*
6167 Fujitsu FRV architecture added by Red Hat frv*-*-*
6170 * New native configurations
6172 Alpha NetBSD alpha*-*-netbsd*
6173 SH NetBSD sh*-*-netbsdelf*
6174 MIPS NetBSD mips*-*-netbsd*
6175 UltraSPARC NetBSD sparc64-*-netbsd*
6177 * OBSOLETE configurations and files
6179 Configurations that have been declared obsolete in this release have
6180 been commented out. Unless there is activity to revive these
6181 configurations, the next release of GDB will have their sources
6182 permanently REMOVED.
6184 Mitsubishi D30V d30v-*-*
6185 OS/9000 i[34]86-*-os9k
6186 IBM AIX PS/2 i[3456]86-*-aix
6187 Fujitsu FR30 fr30-*-elf*
6188 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6189 Argonaut Risc Chip (ARC) arc-*-*
6190 i386 running Mach 3.0 i[3456]86-*-mach3*
6191 i386 running Mach i[3456]86-*-mach*
6192 i386 running OSF/1 i[3456]86-*osf1mk*
6193 HP/Apollo 68k Family m68*-apollo*-sysv*,
6195 m68*-hp-bsd*, m68*-hp-hpux*
6196 I960 with MON960 i960-*-coff
6198 * OBSOLETE languages
6200 CHILL, a Pascal like language used by telecommunications companies.
6202 * REMOVED configurations and files
6204 AMD 29k family via UDI a29k-amd-udi, udi29k
6205 A29K VxWorks a29k-*-vxworks
6206 AMD 29000 embedded, using EBMON a29k-none-none
6207 AMD 29000 embedded with COFF a29k-none-coff
6208 AMD 29000 embedded with a.out a29k-none-aout
6210 testsuite/gdb.hp/gdb.threads-hp/ directory
6212 * New command "set max-user-call-depth <nnn>"
6214 This command allows the user to limit the call depth of user-defined
6215 commands. The default is 1024.
6217 * Changes in FreeBSD/i386 native debugging.
6219 Support for the "generate-core-file" has been added.
6221 * New commands "dump", "append", and "restore".
6223 These commands allow data to be copied from target memory
6224 to a bfd-format or binary file (dump and append), and back
6225 from a file into memory (restore).
6227 * Improved "next/step" support on multi-processor Alpha Tru64.
6229 The previous single-step mechanism could cause unpredictable problems,
6230 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6231 of a software single-step mechanism prevents this.
6233 *** Changes in GDB 5.2.1:
6241 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6242 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6243 Fix, by Joel Brobecker imported from mainline.
6245 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6246 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6247 Fix, by Fred Fish, imported from mainline.
6249 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6250 Surprisingly enough, it works now.
6251 By Michal Ludvig, imported from mainline.
6253 i386 hardware watchpoint support:
6254 avoid misses on second run for some targets.
6255 By Pierre Muller, imported from mainline.
6257 *** Changes in GDB 5.2:
6259 * New command "set trust-readonly-sections on[off]".
6261 This command is a hint that tells gdb that read-only sections
6262 really are read-only (ie. that their contents will not change).
6263 In this mode, gdb will go to the object file rather than the
6264 target to read memory from read-only sections (such as ".text").
6265 This can be a significant performance improvement on some
6266 (notably embedded) targets.
6268 * New command "generate-core-file" (or "gcore").
6270 This new gdb command allows the user to drop a core file of the child
6271 process state at any time. So far it's been implemented only for
6272 GNU/Linux and Solaris, but should be relatively easily ported to other
6273 hosts. Argument is core file name (defaults to core.<pid>).
6275 * New command line option
6277 GDB now accepts --pid or -p followed by a process id.
6279 * Change in command line behavior -- corefiles vs. process ids.
6281 There is a subtle behavior in the way in which GDB handles
6282 command line arguments. The first non-flag argument is always
6283 a program to debug, but the second non-flag argument may either
6284 be a corefile or a process id. Previously, GDB would attempt to
6285 open the second argument as a corefile, and if that failed, would
6286 issue a superfluous error message and then attempt to attach it as
6287 a process. Now, if the second argument begins with a non-digit,
6288 it will be treated as a corefile. If it begins with a digit,
6289 GDB will attempt to attach it as a process, and if no such process
6290 is found, will then attempt to open it as a corefile.
6292 * Changes in ARM configurations.
6294 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6295 configuration is fully multi-arch.
6297 * New native configurations
6299 ARM NetBSD arm*-*-netbsd*
6300 x86 OpenBSD i[3456]86-*-openbsd*
6301 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6302 Sparc64 running FreeBSD sparc64-*-freebsd*
6306 Sanyo XStormy16 xstormy16-elf
6308 * OBSOLETE configurations and files
6310 Configurations that have been declared obsolete in this release have
6311 been commented out. Unless there is activity to revive these
6312 configurations, the next release of GDB will have their sources
6313 permanently REMOVED.
6315 AMD 29k family via UDI a29k-amd-udi, udi29k
6316 A29K VxWorks a29k-*-vxworks
6317 AMD 29000 embedded, using EBMON a29k-none-none
6318 AMD 29000 embedded with COFF a29k-none-coff
6319 AMD 29000 embedded with a.out a29k-none-aout
6321 testsuite/gdb.hp/gdb.threads-hp/ directory
6323 * REMOVED configurations and files
6325 TI TMS320C80 tic80-*-*
6327 PowerPC Solaris powerpcle-*-solaris*
6328 PowerPC Windows NT powerpcle-*-cygwin32
6329 PowerPC Netware powerpc-*-netware*
6330 Harris/CXUX m88k m88*-harris-cxux*
6331 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6332 ns32k-utek-sysv* ns32k-utek-*
6333 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6334 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6335 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6336 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6337 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6339 * Changes to command line processing
6341 The new `--args' feature can be used to specify command-line arguments
6342 for the inferior from gdb's command line.
6344 * Changes to key bindings
6346 There is a new `operate-and-get-next' function bound to `C-o'.
6348 *** Changes in GDB 5.1.1
6350 Fix compile problem on DJGPP.
6352 Fix a problem with floating-point registers on the i386 being
6355 Fix to stop GDB crashing on .debug_str debug info.
6357 Numerous documentation fixes.
6359 Numerous testsuite fixes.
6361 *** Changes in GDB 5.1:
6363 * New native configurations
6365 Alpha FreeBSD alpha*-*-freebsd*
6366 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6367 MIPS GNU/Linux mips*-*-linux*
6368 MIPS SGI Irix 6.x mips*-sgi-irix6*
6369 ia64 AIX ia64-*-aix*
6370 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6374 Motorola 68HC11 and 68HC12 m68hc11-elf
6376 UltraSparc running GNU/Linux sparc64-*-linux*
6378 * OBSOLETE configurations and files
6380 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6381 Harris/CXUX m88k m88*-harris-cxux*
6382 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6383 ns32k-utek-sysv* ns32k-utek-*
6384 TI TMS320C80 tic80-*-*
6386 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6387 PowerPC Solaris powerpcle-*-solaris*
6388 PowerPC Windows NT powerpcle-*-cygwin32
6389 PowerPC Netware powerpc-*-netware*
6390 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6391 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6392 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6393 Apple Macintosh (MPW) host N/A
6395 stuff.c (Program to stuff files into a specially prepared space in kdb)
6396 kdb-start.c (Main loop for the standalone kernel debugger)
6398 Configurations that have been declared obsolete in this release have
6399 been commented out. Unless there is activity to revive these
6400 configurations, the next release of GDB will have their sources
6401 permanently REMOVED.
6403 * REMOVED configurations and files
6405 Altos 3068 m68*-altos-*
6406 Convex c1-*-*, c2-*-*
6408 ARM RISCix arm-*-* (as host)
6412 * GDB has been converted to ISO C.
6414 GDB's source code has been converted to ISO C. In particular, the
6415 sources are fully protoized, and rely on standard headers being
6420 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6422 * The MI enabled by default.
6424 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6425 revised and enabled by default. Packages which use GDB as a debugging
6426 engine behind a UI or another front end are encouraged to switch to
6427 using the GDB/MI interface, instead of the old annotations interface
6428 which is now deprecated.
6430 * Support for debugging Pascal programs.
6432 GDB now includes support for debugging Pascal programs. The following
6433 main features are supported:
6435 - Pascal-specific data types such as sets;
6437 - automatic recognition of Pascal sources based on file-name
6440 - Pascal-style display of data types, variables, and functions;
6442 - a Pascal expression parser.
6444 However, some important features are not yet supported.
6446 - Pascal string operations are not supported at all;
6448 - there are some problems with boolean types;
6450 - Pascal type hexadecimal constants are not supported
6451 because they conflict with the internal variables format;
6453 - support for Pascal objects and classes is not full yet;
6455 - unlike Pascal, GDB is case-sensitive for symbol names.
6457 * Changes in completion.
6459 Commands such as `shell', `run' and `set args', which pass arguments
6460 to inferior programs, now complete on file names, similar to what
6461 users expect at the shell prompt.
6463 Commands which accept locations, such as `disassemble', `print',
6464 `breakpoint', `until', etc. now complete on filenames as well as
6465 program symbols. Thus, if you type "break foob TAB", and the source
6466 files linked into the programs include `foobar.c', that file name will
6467 be one of the candidates for completion. However, file names are not
6468 considered for completion after you typed a colon that delimits a file
6469 name from a name of a function in that file, as in "break foo.c:bar".
6471 `set demangle-style' completes on available demangling styles.
6473 * New platform-independent commands:
6475 It is now possible to define a post-hook for a command as well as a
6476 hook that runs before the command. For more details, see the
6477 documentation of `hookpost' in the GDB manual.
6479 * Changes in GNU/Linux native debugging.
6481 Support for debugging multi-threaded programs has been completely
6482 revised for all platforms except m68k and sparc. You can now debug as
6483 many threads as your system allows you to have.
6485 Attach/detach is supported for multi-threaded programs.
6487 Support for SSE registers was added for x86. This doesn't work for
6488 multi-threaded programs though.
6490 * Changes in MIPS configurations.
6492 Multi-arch support is enabled for all MIPS configurations.
6494 GDB can now be built as native debugger on SGI Irix 6.x systems for
6495 debugging n32 executables. (Debugging 64-bit executables is not yet
6498 * Unified support for hardware watchpoints in all x86 configurations.
6500 Most (if not all) native x86 configurations support hardware-assisted
6501 breakpoints and watchpoints in a unified manner. This support
6502 implements debug register sharing between watchpoints, which allows to
6503 put a virtually infinite number of watchpoints on the same address,
6504 and also supports watching regions up to 16 bytes with several debug
6507 The new maintenance command `maintenance show-debug-regs' toggles
6508 debugging print-outs in functions that insert, remove, and test
6509 watchpoints and hardware breakpoints.
6511 * Changes in the DJGPP native configuration.
6513 New command ``info dos sysinfo'' displays assorted information about
6514 the CPU, OS, memory, and DPMI server.
6516 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6517 display information about segment descriptors stored in GDT, LDT, and
6520 New commands ``info dos pde'' and ``info dos pte'' display entries
6521 from Page Directory and Page Tables (for now works with CWSDPMI only).
6522 New command ``info dos address-pte'' displays the Page Table entry for
6523 a given linear address.
6525 GDB can now pass command lines longer than 126 characters to the
6526 program being debugged (requires an update to the libdbg.a library
6527 which is part of the DJGPP development kit).
6529 DWARF2 debug info is now supported.
6531 It is now possible to `step' and `next' through calls to `longjmp'.
6533 * Changes in documentation.
6535 All GDB documentation was converted to GFDL, the GNU Free
6536 Documentation License.
6538 Tracepoints-related commands are now fully documented in the GDB
6541 TUI, the Text-mode User Interface, is now documented in the manual.
6543 Tracepoints-related commands are now fully documented in the GDB
6546 The "GDB Internals" manual now has an index. It also includes
6547 documentation of `ui_out' functions, GDB coding standards, x86
6548 hardware watchpoints, and memory region attributes.
6550 * GDB's version number moved to ``version.in''
6552 The Makefile variable VERSION has been replaced by the file
6553 ``version.in''. People creating GDB distributions should update the
6554 contents of this file.
6558 GUD support is now a standard part of the EMACS distribution.
6560 *** Changes in GDB 5.0:
6562 * Improved support for debugging FP programs on x86 targets
6564 Unified and much-improved support for debugging floating-point
6565 programs on all x86 targets. In particular, ``info float'' now
6566 displays the FP registers in the same format on all x86 targets, with
6567 greater level of detail.
6569 * Improvements and bugfixes in hardware-assisted watchpoints
6571 It is now possible to watch array elements, struct members, and
6572 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6573 on x86 targets no longer erroneously trigger when the address is
6576 * Improvements in the native DJGPP version of GDB
6578 The distribution now includes all the scripts and auxiliary files
6579 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6580 machines ``out of the box''.
6582 The DJGPP version can now debug programs that use signals. It is
6583 possible to catch signals that happened in the debuggee, deliver
6584 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6585 would kill the program being debugged.) Programs that hook hardware
6586 interrupts (keyboard, timer, etc.) can also be debugged.
6588 It is now possible to debug DJGPP programs that redirect their
6589 standard handles or switch them to raw (as opposed to cooked) mode, or
6590 even close them. The command ``run < foo > bar'' works as expected,
6591 and ``info terminal'' reports useful information about the debuggee's
6592 terminal, including raw/cooked mode, redirection, etc.
6594 The DJGPP version now uses termios functions for console I/O, which
6595 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6598 DOS-style file names with drive letters are now fully supported by
6601 It is now possible to debug DJGPP programs that switch their working
6602 directory. It is also possible to rerun the debuggee any number of
6603 times without restarting GDB; thus, you can use the same setup,
6604 breakpoints, etc. for many debugging sessions.
6606 * New native configurations
6608 ARM GNU/Linux arm*-*-linux*
6609 PowerPC GNU/Linux powerpc-*-linux*
6613 Motorola MCore mcore-*-*
6614 x86 VxWorks i[3456]86-*-vxworks*
6615 PowerPC VxWorks powerpc-*-vxworks*
6616 TI TMS320C80 tic80-*-*
6618 * OBSOLETE configurations
6620 Altos 3068 m68*-altos-*
6621 Convex c1-*-*, c2-*-*
6623 ARM RISCix arm-*-* (as host)
6626 Configurations that have been declared obsolete will be commented out,
6627 but the code will be left in place. If there is no activity to revive
6628 these configurations before the next release of GDB, the sources will
6629 be permanently REMOVED.
6631 * Gould support removed
6633 Support for the Gould PowerNode and NP1 has been removed.
6635 * New features for SVR4
6637 On SVR4 native platforms (such as Solaris), if you attach to a process
6638 without first loading a symbol file, GDB will now attempt to locate and
6639 load symbols from the running process's executable file.
6641 * Many C++ enhancements
6643 C++ support has been greatly improved. Overload resolution now works properly
6644 in almost all cases. RTTI support is on the way.
6646 * Remote targets can connect to a sub-program
6648 A popen(3) style serial-device has been added. This device starts a
6649 sub-process (such as a stand-alone simulator) and then communicates
6650 with that. The sub-program to run is specified using the syntax
6651 ``|<program> <args>'' vis:
6653 (gdb) set remotedebug 1
6654 (gdb) target extended-remote |mn10300-elf-sim program-args
6656 * MIPS 64 remote protocol
6658 A long standing bug in the mips64 remote protocol where by GDB
6659 expected certain 32 bit registers (ex SR) to be transfered as 32
6660 instead of 64 bits has been fixed.
6662 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6663 added to provide backward compatibility with older versions of GDB.
6665 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6667 The command ``set remotebinarydownload'' command has been replaced by
6668 ``set remote X-packet''. Other commands in ``set remote'' family
6669 include ``set remote P-packet''.
6671 * Breakpoint commands accept ranges.
6673 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6674 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6675 ``tracepoint passcount'' also accepts a range of tracepoints.
6677 * ``apropos'' command added.
6679 The ``apropos'' command searches through command names and
6680 documentation strings, printing out matches, making it much easier to
6681 try to find a command that does what you are looking for.
6685 A new machine oriented interface (MI) has been added to GDB. This
6686 interface is designed for debug environments running GDB as a separate
6687 process. This is part of the long term libGDB project. See the
6688 "GDB/MI" chapter of the GDB manual for further information. It can be
6689 enabled by configuring with:
6691 .../configure --enable-gdbmi
6693 *** Changes in GDB-4.18:
6695 * New native configurations
6697 HP-UX 10.20 hppa*-*-hpux10.20
6698 HP-UX 11.x hppa*-*-hpux11.0*
6699 M68K GNU/Linux m68*-*-linux*
6703 Fujitsu FR30 fr30-*-elf*
6704 Intel StrongARM strongarm-*-*
6705 Mitsubishi D30V d30v-*-*
6707 * OBSOLETE configurations
6709 Gould PowerNode, NP1 np1-*-*, pn-*-*
6711 Configurations that have been declared obsolete will be commented out,
6712 but the code will be left in place. If there is no activity to revive
6713 these configurations before the next release of GDB, the sources will
6714 be permanently REMOVED.
6718 As a compatibility experiment, GDB's source files buildsym.h and
6719 buildsym.c have been converted to pure standard C, no longer
6720 containing any K&R compatibility code. We believe that all systems in
6721 use today either come with a standard C compiler, or have a GCC port
6722 available. If this is not true, please report the affected
6723 configuration to bug-gdb@gnu.org immediately. See the README file for
6724 information about getting a standard C compiler if you don't have one
6729 GDB now uses readline 2.2.
6731 * set extension-language
6733 You can now control the mapping between filename extensions and source
6734 languages by using the `set extension-language' command. For instance,
6735 you can ask GDB to treat .c files as C++ by saying
6736 set extension-language .c c++
6737 The command `info extensions' lists all of the recognized extensions
6738 and their associated languages.
6740 * Setting processor type for PowerPC and RS/6000
6742 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6743 you can use the `set processor' command to specify what variant of the
6744 PowerPC family you are debugging. The command
6748 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6749 following PowerPC and RS6000 variants:
6751 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6752 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6754 403GC IBM PowerPC 403GC
6755 505 Motorola PowerPC 505
6756 860 Motorola PowerPC 860 or 850
6757 601 Motorola PowerPC 601
6758 602 Motorola PowerPC 602
6759 603 Motorola/IBM PowerPC 603 or 603e
6760 604 Motorola PowerPC 604 or 604e
6761 750 Motorola/IBM PowerPC 750 or 750
6763 At the moment, this command just tells GDB what to name the
6764 special-purpose processor registers. Since almost all the affected
6765 registers are inaccessible to user-level programs, this command is
6766 only useful for remote debugging in its present form.
6770 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6771 more extensive support for HP-UX. Added features include shared
6772 library support, kernel threads and hardware watchpoints for 11.00,
6773 support for HP's ANSI C and C++ compilers, and a compatibility mode
6774 for xdb and dbx commands.
6778 HP's donation includes the new concept of catchpoints, which is a
6779 generalization of the old catch command. On HP-UX, it is now possible
6780 to catch exec, fork, and vfork, as well as library loading.
6782 This means that the existing catch command has changed; its first
6783 argument now specifies the type of catch to be set up. See the
6784 output of "help catch" for a list of catchpoint types.
6786 * Debugging across forks
6788 On HP-UX, you can choose which process to debug when a fork() happens
6793 HP has donated a curses-based terminal user interface (TUI). To get
6794 it, build with --enable-tui. Although this can be enabled for any
6795 configuration, at present it only works for native HP debugging.
6797 * GDB remote protocol additions
6799 A new protocol packet 'X' that writes binary data is now available.
6800 Default behavior is to try 'X', then drop back to 'M' if the stub
6801 fails to respond. The settable variable `remotebinarydownload'
6802 allows explicit control over the use of 'X'.
6804 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6805 full 64-bit address. The command
6807 set remoteaddresssize 32
6809 can be used to revert to the old behaviour. For existing remote stubs
6810 the change should not be noticed, as the additional address information
6813 In order to assist in debugging stubs, you may use the maintenance
6814 command `packet' to send any text string to the stub. For instance,
6816 maint packet heythere
6818 sends the packet "$heythere#<checksum>". Note that it is very easy to
6819 disrupt a debugging session by sending the wrong packet at the wrong
6822 The compare-sections command allows you to compare section data on the
6823 target to what is in the executable file without uploading or
6824 downloading, by comparing CRC checksums.
6826 * Tracing can collect general expressions
6828 You may now collect general expressions at tracepoints. This requires
6829 further additions to the target-side stub; see tracepoint.c and
6830 doc/agentexpr.texi for further details.
6832 * mask-address variable for Mips
6834 For Mips targets, you may control the zeroing of the upper 32 bits of
6835 a 64-bit address by entering `set mask-address on'. This is mainly
6836 of interest to users of embedded R4xxx and R5xxx processors.
6838 * Higher serial baud rates
6840 GDB's serial code now allows you to specify baud rates 57600, 115200,
6841 230400, and 460800 baud. (Note that your host system may not be able
6842 to achieve all of these rates.)
6846 The i960 configuration now includes an initial implementation of a
6847 builtin simulator, contributed by Jim Wilson.
6850 *** Changes in GDB-4.17:
6852 * New native configurations
6854 Alpha GNU/Linux alpha*-*-linux*
6855 Unixware 2.x i[3456]86-unixware2*
6856 Irix 6.x mips*-sgi-irix6*
6857 PowerPC GNU/Linux powerpc-*-linux*
6858 PowerPC Solaris powerpcle-*-solaris*
6859 Sparc GNU/Linux sparc-*-linux*
6860 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6864 Argonaut Risc Chip (ARC) arc-*-*
6865 Hitachi H8/300S h8300*-*-*
6866 Matsushita MN10200 w/simulator mn10200-*-*
6867 Matsushita MN10300 w/simulator mn10300-*-*
6868 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6869 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6870 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6871 Mitsubishi D10V w/simulator d10v-*-*
6872 Mitsubishi M32R/D w/simulator m32r-*-elf*
6873 Tsqware Sparclet sparclet-*-*
6874 NEC V850 w/simulator v850-*-*
6876 * New debugging protocols
6878 ARM with RDI protocol arm*-*-*
6879 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6880 DDB and LSI variants of PMON protocol mips*-*-*
6881 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6882 PowerPC with SDS protocol powerpc{,le}-*-eabi
6883 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6887 All configurations can now understand and use the DWARF 2 debugging
6888 format. The choice is automatic, if the symbol file contains DWARF 2
6893 GDB now includes basic Java language support. This support is
6894 only useful with Java compilers that produce native machine code.
6896 * solib-absolute-prefix and solib-search-path
6898 For SunOS and SVR4 shared libraries, you may now set the prefix for
6899 loading absolute shared library symbol files, and the search path for
6900 locating non-absolute shared library symbol files.
6902 * Live range splitting
6904 GDB can now effectively debug code for which GCC has performed live
6905 range splitting as part of its optimization. See gdb/doc/LRS for
6906 more details on the expected format of the stabs information.
6910 GDB's support for the GNU Hurd, including thread debugging, has been
6911 updated to work with current versions of the Hurd.
6915 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6916 instruction set. ARM GDB automatically detects when Thumb
6917 instructions are in use, and adjusts disassembly and backtracing
6922 GDB's MIPS target configurations now handle the MIP16 16-bit
6927 GDB now includes support for overlays; if an executable has been
6928 linked such that multiple sections are based at the same address, GDB
6929 will decide which section to use for symbolic info. You can choose to
6930 control the decision manually, using overlay commands, or implement
6931 additional target-side support and use "overlay load-target" to bring
6932 in the overlay mapping. Do "help overlay" for more detail.
6936 The command "info symbol <address>" displays information about
6937 the symbol at the specified address.
6941 The standard remote protocol now includes an extension that allows
6942 asynchronous collection and display of trace data. This requires
6943 extensive support in the target-side debugging stub. Tracing mode
6944 includes a new interaction mode in GDB and new commands: see the
6945 file tracepoint.c for more details.
6949 Configurations for embedded MIPS now include a simulator contributed
6950 by Cygnus Solutions. The simulator supports the instruction sets
6951 of most MIPS variants.
6955 Sparc configurations may now include the ERC32 simulator contributed
6956 by the European Space Agency. The simulator is not built into
6957 Sparc targets by default; configure with --enable-sim to include it.
6961 For target configurations that may include multiple variants of a
6962 basic architecture (such as MIPS and SH), you may now set the
6963 architecture explicitly. "set arch" sets, "info arch" lists
6964 the possible architectures.
6966 *** Changes in GDB-4.16:
6968 * New native configurations
6970 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6971 M68K NetBSD m68k-*-netbsd*
6972 PowerPC AIX 4.x powerpc-*-aix*
6973 PowerPC MacOS powerpc-*-macos*
6974 PowerPC Windows NT powerpcle-*-cygwin32
6975 RS/6000 AIX 4.x rs6000-*-aix4*
6979 ARM with RDP protocol arm-*-*
6980 I960 with MON960 i960-*-coff
6981 MIPS VxWorks mips*-*-vxworks*
6982 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6983 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6985 Matra Sparclet sparclet-*-*
6989 The powerpc-eabi configuration now includes the PSIM simulator,
6990 contributed by Andrew Cagney, with assistance from Mike Meissner.
6991 PSIM is a very elaborate model of the PowerPC, including not only
6992 basic instruction set execution, but also details of execution unit
6993 performance and I/O hardware. See sim/ppc/README for more details.
6997 GDB now works with Solaris 2.5.
6999 * Windows 95/NT native
7001 GDB will now work as a native debugger on Windows 95 and Windows NT.
7002 To build it from source, you must use the "gnu-win32" environment,
7003 which uses a DLL to emulate enough of Unix to run the GNU tools.
7004 Further information, binaries, and sources are available at
7005 ftp.cygnus.com, under pub/gnu-win32.
7007 * dont-repeat command
7009 If a user-defined command includes the command `dont-repeat', then the
7010 command will not be repeated if the user just types return. This is
7011 useful if the command is time-consuming to run, so that accidental
7012 extra keystrokes don't run the same command many times.
7014 * Send break instead of ^C
7016 The standard remote protocol now includes an option to send a break
7017 rather than a ^C to the target in order to interrupt it. By default,
7018 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7020 * Remote protocol timeout
7022 The standard remote protocol includes a new variable `remotetimeout'
7023 that allows you to set the number of seconds before GDB gives up trying
7024 to read from the target. The default value is 2.
7026 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7028 By default GDB will automatically keep track of objects as they are
7029 loaded and unloaded by the dynamic linker. By using the command `set
7030 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7031 when shared library events occur, thus allowing you to set breakpoints
7032 in shared libraries which are explicitly loaded by the inferior.
7034 Note this feature does not work on hpux8. On hpux9 you must link
7035 /usr/lib/end.o into your program. This feature should work
7036 automatically on hpux10.
7038 * Irix 5.x hardware watchpoint support
7040 Irix 5 configurations now support the use of hardware watchpoints.
7042 * Mips protocol "SYN garbage limit"
7044 When debugging a Mips target using the `target mips' protocol, you
7045 may set the number of characters that GDB will ignore by setting
7046 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7047 every character. The default value is 1050.
7049 * Recording and replaying remote debug sessions
7051 If you set `remotelogfile' to the name of a file, gdb will write to it
7052 a recording of a remote debug session. This recording may then be
7053 replayed back to gdb using "gdbreplay". See gdbserver/README for
7054 details. This is useful when you have a problem with GDB while doing
7055 remote debugging; you can make a recording of the session and send it
7056 to someone else, who can then recreate the problem.
7058 * Speedups for remote debugging
7060 GDB includes speedups for downloading and stepping MIPS systems using
7061 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7062 and more efficient S-record downloading.
7064 * Memory use reductions and statistics collection
7066 GDB now uses less memory and reports statistics about memory usage.
7067 Try the `maint print statistics' command, for example.
7069 *** Changes in GDB-4.15:
7071 * Psymtabs for XCOFF
7073 The symbol reader for AIX GDB now uses partial symbol tables. This
7074 can greatly improve startup time, especially for large executables.
7076 * Remote targets use caching
7078 Remote targets now use a data cache to speed up communication with the
7079 remote side. The data cache could lead to incorrect results because
7080 it doesn't know about volatile variables, thus making it impossible to
7081 debug targets which use memory mapped I/O devices. `set remotecache
7082 off' turns the data cache off.
7084 * Remote targets may have threads
7086 The standard remote protocol now includes support for multiple threads
7087 in the target system, using new protocol commands 'H' and 'T'. See
7088 gdb/remote.c for details.
7092 If GDB is configured with `--enable-netrom', then it will include
7093 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7094 acts as though it is a bank of ROM on the target board, but you can
7095 write into it over the network. GDB's support consists only of
7096 support for fast loading into the emulated ROM; to debug, you must use
7097 another protocol, such as standard remote protocol. The usual
7098 sequence is something like
7100 target nrom <netrom-hostname>
7102 target remote <netrom-hostname>:1235
7106 GDB now includes support for the Apple Macintosh, as a host only. It
7107 may be run as either an MPW tool or as a standalone application, and
7108 it can debug through the serial port. All the usual GDB commands are
7109 available, but to the target command, you must supply "serial" as the
7110 device type instead of "/dev/ttyXX". See mpw-README in the main
7111 directory for more information on how to build. The MPW configuration
7112 scripts */mpw-config.in support only a few targets, and only the
7113 mips-idt-ecoff target has been tested.
7117 GDB configuration now uses autoconf. This is not user-visible,
7118 but does simplify configuration and building.
7122 GDB now supports hpux10.
7124 *** Changes in GDB-4.14:
7126 * New native configurations
7128 x86 FreeBSD i[345]86-*-freebsd
7129 x86 NetBSD i[345]86-*-netbsd
7130 NS32k NetBSD ns32k-*-netbsd
7131 Sparc NetBSD sparc-*-netbsd
7135 A29K VxWorks a29k-*-vxworks
7136 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7137 CPU32 EST-300 emulator m68*-*-est*
7138 PowerPC ELF powerpc-*-elf
7141 * Alpha OSF/1 support for procfs
7143 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7144 possible to attach to running processes. As the mounting of the /proc
7145 filesystem is optional on the Alpha, GDB automatically determines
7146 the availability of /proc during startup. This can lead to problems
7147 if /proc is unmounted after GDB has been started.
7149 * Arguments to user-defined commands
7151 User commands may accept up to 10 arguments separated by whitespace.
7152 Arguments are accessed within the user command via $arg0..$arg9. A
7155 print $arg0 + $arg1 + $arg2
7157 To execute the command use:
7160 Defines the command "adder" which prints the sum of its three arguments.
7161 Note the arguments are text substitutions, so they may reference variables,
7162 use complex expressions, or even perform inferior function calls.
7164 * New `if' and `while' commands
7166 This makes it possible to write more sophisticated user-defined
7167 commands. Both commands take a single argument, which is the
7168 expression to evaluate, and must be followed by the commands to
7169 execute, one per line, if the expression is nonzero, the list being
7170 terminated by the word `end'. The `if' command list may include an
7171 `else' word, which causes the following commands to be executed only
7172 if the expression is zero.
7174 * Fortran source language mode
7176 GDB now includes partial support for Fortran 77. It will recognize
7177 Fortran programs and can evaluate a subset of Fortran expressions, but
7178 variables and functions may not be handled correctly. GDB will work
7179 with G77, but does not yet know much about symbols emitted by other
7182 * Better HPUX support
7184 Most debugging facilities now work on dynamic executables for HPPAs
7185 running hpux9 or later. You can attach to running dynamically linked
7186 processes, but by default the dynamic libraries will be read-only, so
7187 for instance you won't be able to put breakpoints in them. To change
7188 that behavior do the following before running the program:
7194 This will cause the libraries to be mapped private and read-write.
7195 To revert to the normal behavior, do this:
7201 You cannot set breakpoints or examine data in the library until after
7202 the library is loaded if the function/data symbols do not have
7205 GDB can now also read debug symbols produced by the HP C compiler on
7206 HPPAs (sorry, no C++, Fortran or 68k support).
7208 * Target byte order now dynamically selectable
7210 You can choose which byte order to use with a target system, via the
7211 commands "set endian big" and "set endian little", and you can see the
7212 current setting by using "show endian". You can also give the command
7213 "set endian auto", in which case GDB will use the byte order
7214 associated with the executable. Currently, only embedded MIPS
7215 configurations support dynamic selection of target byte order.
7217 * New DOS host serial code
7219 This version uses DPMI interrupts to handle buffered I/O, so you
7220 no longer need to run asynctsr when debugging boards connected to
7223 *** Changes in GDB-4.13:
7225 * New "complete" command
7227 This lists all the possible completions for the rest of the line, if it
7228 were to be given as a command itself. This is intended for use by emacs.
7230 * Trailing space optional in prompt
7232 "set prompt" no longer adds a space for you after the prompt you set. This
7233 allows you to set a prompt which ends in a space or one that does not.
7235 * Breakpoint hit counts
7237 "info break" now displays a count of the number of times the breakpoint
7238 has been hit. This is especially useful in conjunction with "ignore"; you
7239 can ignore a large number of breakpoint hits, look at the breakpoint info
7240 to see how many times the breakpoint was hit, then run again, ignoring one
7241 less than that number, and this will get you quickly to the last hit of
7244 * Ability to stop printing at NULL character
7246 "set print null-stop" will cause GDB to stop printing the characters of
7247 an array when the first NULL is encountered. This is useful when large
7248 arrays actually contain only short strings.
7250 * Shared library breakpoints
7252 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7253 breakpoints in shared libraries before the executable is run.
7255 * Hardware watchpoints
7257 There is a new hardware breakpoint for the watch command for sparclite
7258 targets. See gdb/sparclite/hw_breakpoint.note.
7260 Hardware watchpoints are also now supported under GNU/Linux.
7264 Annotations have been added. These are for use with graphical interfaces,
7265 and are still experimental. Currently only gdba.el uses these.
7267 * Improved Irix 5 support
7269 GDB now works properly with Irix 5.2.
7271 * Improved HPPA support
7273 GDB now works properly with the latest GCC and GAS.
7275 * New native configurations
7277 Sequent PTX4 i[34]86-sequent-ptx4
7278 HPPA running OSF/1 hppa*-*-osf*
7279 Atari TT running SVR4 m68*-*-sysv4*
7280 RS/6000 LynxOS rs6000-*-lynxos*
7284 OS/9000 i[34]86-*-os9k
7285 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7288 * Hitachi SH7000 and E7000-PC ICE support
7290 There is now support for communicating with the Hitachi E7000-PC ICE.
7291 This is available automatically when GDB is configured for the SH.
7295 As usual, a variety of small fixes and improvements, both generic
7296 and configuration-specific. See the ChangeLog for more detail.
7298 *** Changes in GDB-4.12:
7300 * Irix 5 is now supported
7304 GDB-4.12 on the HPPA has a number of changes which make it unable
7305 to debug the output from the currently released versions of GCC and
7306 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7307 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7308 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7311 *** Changes in GDB-4.11:
7313 * User visible changes:
7317 The "set remotedebug" option is now consistent between the mips remote
7318 target, remote targets using the gdb-specific protocol, UDI (AMD's
7319 debug protocol for the 29k) and the 88k bug monitor. It is now an
7320 integer specifying a debug level (normally 0 or 1, but 2 means more
7321 debugging info for the mips target).
7323 * DEC Alpha native support
7325 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7326 debug info, but GDB works fairly well with the DEC compiler and should
7327 work with a future GCC release. See the README file for a few
7328 Alpha-specific notes.
7330 * Preliminary thread implementation
7332 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7334 * LynxOS native and target support for 386
7336 This release has been hosted on LynxOS 2.2, and also can be configured
7337 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7340 * Improvements in C++ mangling/demangling.
7342 This release has much better g++ debugging, specifically in name
7343 mangling/demangling, virtual function calls, print virtual table,
7344 call methods, ...etc.
7346 *** Changes in GDB-4.10:
7348 * User visible changes:
7350 Remote debugging using the GDB-specific (`target remote') protocol now
7351 supports the `load' command. This is only useful if you have some
7352 other way of getting the stub to the target system, and you can put it
7353 somewhere in memory where it won't get clobbered by the download.
7355 Filename completion now works.
7357 When run under emacs mode, the "info line" command now causes the
7358 arrow to point to the line specified. Also, "info line" prints
7359 addresses in symbolic form (as well as hex).
7361 All vxworks based targets now support a user settable option, called
7362 vxworks-timeout. This option represents the number of seconds gdb
7363 should wait for responses to rpc's. You might want to use this if
7364 your vxworks target is, perhaps, a slow software simulator or happens
7365 to be on the far side of a thin network line.
7369 This release contains support for using a DEC alpha as a GDB host for
7370 cross debugging. Native alpha debugging is not supported yet.
7373 *** Changes in GDB-4.9:
7377 This is the first GDB release which is accompanied by a matching testsuite.
7378 The testsuite requires installation of dejagnu, which should be available
7379 via ftp from most sites that carry GNU software.
7383 'Cfront' style demangling has had its name changed to 'ARM' style, to
7384 emphasize that it was written from the specifications in the C++ Annotated
7385 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7386 disclaimers, it still generated too much confusion with users attempting to
7387 use gdb with AT&T cfront.
7391 GDB now uses a standard remote interface to a simulator library.
7392 So far, the library contains simulators for the Zilog Z8001/2, the
7393 Hitachi H8/300, H8/500 and Super-H.
7395 * New targets supported
7397 H8/300 simulator h8300-hitachi-hms or h8300hms
7398 H8/500 simulator h8500-hitachi-hms or h8500hms
7399 SH simulator sh-hitachi-hms or sh
7400 Z8000 simulator z8k-zilog-none or z8ksim
7401 IDT MIPS board over serial line mips-idt-ecoff
7403 Cross-debugging to GO32 targets is supported. It requires a custom
7404 version of the i386-stub.c module which is integrated with the
7405 GO32 memory extender.
7407 * New remote protocols
7409 MIPS remote debugging protocol.
7411 * New source languages supported
7413 This version includes preliminary support for Chill, a Pascal like language
7414 used by telecommunications companies. Chill support is also being integrated
7415 into the GNU compiler, but we don't know when it will be publically available.
7418 *** Changes in GDB-4.8:
7420 * HP Precision Architecture supported
7422 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7423 version of this support was available as a set of patches from the
7424 University of Utah. GDB does not support debugging of programs
7425 compiled with the HP compiler, because HP will not document their file
7426 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7427 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7429 Many problems in the preliminary version have been fixed.
7431 * Faster and better demangling
7433 We have improved template demangling and fixed numerous bugs in the GNU style
7434 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7435 character types (wchar_t) are now supported. Demangling of each symbol is now
7436 only done once, and is cached when the symbol table for a file is read in.
7437 This results in a small increase in memory usage for C programs, a moderate
7438 increase in memory usage for C++ programs, and a fantastic speedup in
7441 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7442 from the specifications in the Annotated Reference Manual, which AT&T's
7443 compiler does not actually implement.
7445 * G++ multiple inheritance compiler problem
7447 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7448 inheritance lattices was reworked to properly discover ambiguities. We
7449 recently found an example which causes this new algorithm to fail in a
7450 very subtle way, producing bad debug information for those classes.
7451 The file 'gcc.patch' (in this directory) can be applied to gcc to
7452 circumvent the problem. A future GCC release will contain a complete
7455 The previous G++ debug info problem (mentioned below for the gdb-4.7
7456 release) is fixed in gcc version 2.3.2.
7458 * Improved configure script
7460 The `configure' script will now attempt to guess your system type if
7461 you don't supply a host system type. The old scheme of supplying a
7462 host system triplet is preferable over using this. All the magic is
7463 done in the new `config.guess' script. Examine it for details.
7465 We have also brought our configure script much more in line with the FSF's
7466 version. It now supports the --with-xxx options. In particular,
7467 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7468 The resulting GDB will not be able to read arbitrary object file formats --
7469 only the format ``expected'' to be used on the configured target system.
7470 We hope to make this the default in a future release.
7472 * Documentation improvements
7474 There's new internal documentation on how to modify GDB, and how to
7475 produce clean changes to the code. We implore people to read it
7476 before submitting changes.
7478 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7479 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7480 `info' files are also provided. To build `info' files from scratch,
7481 you will need the latest `makeinfo' release, which will be available in
7482 a future texinfo-X.Y release.
7484 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7485 We're not sure exactly which versions have this problem, but it has
7486 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7487 or better. If that isn't possible, there is a patch in
7488 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7489 around this problem.
7493 GDB now supports array constants that can be used in expressions typed in by
7494 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7495 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7498 The new directory `gdb/sparclite' contains a program that demonstrates
7499 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7501 * New native hosts supported
7503 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7504 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7506 * New targets supported
7508 AMD 29k family via UDI a29k-amd-udi or udi29k
7510 * New file formats supported
7512 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7513 HPUX core files, and SCO 3.2v2 core files.
7517 Attaching to processes now works again; thanks for the many bug reports.
7519 We have also stomped on a bunch of core dumps caused by
7520 printf_filtered("%s") problems.
7522 We eliminated a copyright problem on the rpc and ptrace header files
7523 for VxWorks, which was discovered at the last minute during the 4.7
7524 release. You should now be able to build a VxWorks GDB.
7526 You can now interrupt gdb while an attached process is running. This
7527 will cause the attached process to stop, and give control back to GDB.
7529 We fixed problems caused by using too many file descriptors
7530 for reading symbols from object files and libraries. This was
7531 especially a problem for programs that used many (~100) shared
7534 The `step' command now only enters a subroutine if there is line number
7535 information for the subroutine. Otherwise it acts like the `next'
7536 command. Previously, `step' would enter subroutines if there was
7537 any debugging information about the routine. This avoids problems
7538 when using `cc -g1' on MIPS machines.
7540 * Internal improvements
7542 GDB's internal interfaces have been improved to make it easier to support
7543 debugging of multiple languages in the future.
7545 GDB now uses a common structure for symbol information internally.
7546 Minimal symbols (derived from linkage symbols in object files), partial
7547 symbols (from a quick scan of debug information), and full symbols
7548 contain a common subset of information, making it easier to write
7549 shared code that handles any of them.
7551 * New command line options
7553 We now accept --silent as an alias for --quiet.
7557 The memory-mapped-malloc library is now licensed under the GNU Library
7558 General Public License.
7560 *** Changes in GDB-4.7:
7562 * Host/native/target split
7564 GDB has had some major internal surgery to untangle the support for
7565 hosts and remote targets. Now, when you configure GDB for a remote
7566 target, it will no longer load in all of the support for debugging
7567 local programs on the host. When fully completed and tested, this will
7568 ensure that arbitrary host/target combinations are possible.
7570 The primary conceptual shift is to separate the non-portable code in
7571 GDB into three categories. Host specific code is required any time GDB
7572 is compiled on that host, regardless of the target. Target specific
7573 code relates to the peculiarities of the target, but can be compiled on
7574 any host. Native specific code is everything else: it can only be
7575 built when the host and target are the same system. Child process
7576 handling and core file support are two common `native' examples.
7578 GDB's use of /proc for controlling Unix child processes is now cleaner.
7579 It has been split out into a single module under the `target_ops' vector,
7580 plus two native-dependent functions for each system that uses /proc.
7582 * New hosts supported
7584 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7585 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7586 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7588 * New targets supported
7590 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7591 68030 and CPU32 m68030-*-*, m68332-*-*
7593 * New native hosts supported
7595 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7596 (386bsd is not well tested yet)
7597 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7599 * New file formats supported
7601 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7602 supports reading of `a.out.adobe' object files, which are an a.out
7603 format extended with minimal information about multiple sections.
7607 `show copying' is the same as the old `info copying'.
7608 `show warranty' is the same as `info warrantee'.
7609 These were renamed for consistency. The old commands continue to work.
7611 `info handle' is a new alias for `info signals'.
7613 You can now define pre-command hooks, which attach arbitrary command
7614 scripts to any command. The commands in the hook will be executed
7615 prior to the user's command. You can also create a hook which will be
7616 executed whenever the program stops. See gdb.texinfo.
7620 We now deal with Cfront style name mangling, and can even extract type
7621 info from mangled symbols. GDB can automatically figure out which
7622 symbol mangling style your C++ compiler uses.
7624 Calling of methods and virtual functions has been improved as well.
7628 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7629 fixed. This was due to mishandling of the extra N_SO stabs output
7632 We also finally got Ultrix 4.2 running in house, and fixed core file
7633 support, with help from a dozen people on the net.
7635 John M. Farrell discovered that the reason that single-stepping was so
7636 slow on all of the Mips based platforms (primarily SGI and DEC) was
7637 that we were trying to demangle and lookup a symbol used for internal
7638 purposes on every instruction that was being stepped through. Changing
7639 the name of that symbol so that it couldn't be mistaken for a C++
7640 mangled symbol sped things up a great deal.
7642 Rich Pixley sped up symbol lookups in general by getting much smarter
7643 about when C++ symbol mangling is necessary. This should make symbol
7644 completion (TAB on the command line) much faster. It's not as fast as
7645 we'd like, but it's significantly faster than gdb-4.6.
7649 A new user controllable variable 'call_scratch_address' can
7650 specify the location of a scratch area to be used when GDB
7651 calls a function in the target. This is necessary because the
7652 usual method of putting the scratch area on the stack does not work
7653 in systems that have separate instruction and data spaces.
7655 We integrated changes to support the 29k UDI (Universal Debugger
7656 Interface), but discovered at the last minute that we didn't have all
7657 of the appropriate copyright paperwork. We are working with AMD to
7658 resolve this, and hope to have it available soon.
7662 We have sped up the remote serial line protocol, especially for targets
7663 with lots of registers. It now supports a new `expedited status' ('T')
7664 message which can be used in place of the existing 'S' status message.
7665 This allows the remote stub to send only the registers that GDB
7666 needs to make a quick decision about single-stepping or conditional
7667 breakpoints, eliminating the need to fetch the entire register set for
7668 each instruction being stepped through.
7670 The GDB remote serial protocol now implements a write-through cache for
7671 registers, only re-reading the registers if the target has run.
7673 There is also a new remote serial stub for SPARC processors. You can
7674 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7675 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7676 processor with a serial port.
7680 Configure.in files have become much easier to read and modify. A new
7681 `table driven' format makes it more obvious what configurations are
7682 supported, and what files each one uses.
7686 There is a new opcodes library which will eventually contain all of the
7687 disassembly routines and opcode tables. At present, it only contains
7688 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7689 disassembler (binutils/objdump) to share these routines.
7691 The libiberty library is now copylefted under the GNU Library General
7692 Public License. This allows more liberal use, and was done so libg++
7693 can use it. This makes no difference to GDB, since the Library License
7694 grants all the rights from the General Public License.
7698 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7699 reference to the stabs symbol info used by the debugger. It is (as far
7700 as we know) the only published document on this fascinating topic. We
7701 encourage you to read it, compare it to the stabs information on your
7702 system, and send improvements on the document in general (to
7703 bug-gdb@prep.ai.mit.edu).
7705 And, of course, many bugs have been fixed.
7708 *** Changes in GDB-4.6:
7710 * Better support for C++ function names
7712 GDB now accepts as input the "demangled form" of C++ overloaded function
7713 names and member function names, and can do command completion on such names
7714 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7715 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7716 Make use of command completion, it is your friend.
7718 GDB also now accepts a variety of C++ mangled symbol formats. They are
7719 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7720 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7721 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7722 for the list of formats.
7724 * G++ symbol mangling problem
7726 Recent versions of gcc have a bug in how they emit debugging information for
7727 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7728 directory) can be applied to gcc to fix the problem. Alternatively, if you
7729 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7730 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7731 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7734 * New 'maintenance' command
7736 All of the commands related to hacking GDB internals have been moved out of
7737 the main command set, and now live behind the 'maintenance' command. This
7738 can also be abbreviated as 'mt'. The following changes were made:
7740 dump-me -> maintenance dump-me
7741 info all-breakpoints -> maintenance info breakpoints
7742 printmsyms -> maintenance print msyms
7743 printobjfiles -> maintenance print objfiles
7744 printpsyms -> maintenance print psymbols
7745 printsyms -> maintenance print symbols
7747 The following commands are new:
7749 maintenance demangle Call internal GDB demangler routine to
7750 demangle a C++ link name and prints the result.
7751 maintenance print type Print a type chain for a given symbol
7753 * Change to .gdbinit file processing
7755 We now read the $HOME/.gdbinit file before processing the argv arguments
7756 (e.g. reading symbol files or core files). This allows global parameters to
7757 be set, which will apply during the symbol reading. The ./.gdbinit is still
7758 read after argv processing.
7760 * New hosts supported
7762 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7764 GNU/Linux support i386-unknown-linux or linux
7766 We are also including code to support the HP/PA running BSD and HPUX. This
7767 is almost guaranteed not to work, as we didn't have time to test or build it
7768 for this release. We are including it so that the more adventurous (or
7769 masochistic) of you can play with it. We also had major problems with the
7770 fact that the compiler that we got from HP doesn't support the -g option.
7773 * New targets supported
7775 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7777 * More smarts about finding #include files
7779 GDB now remembers the compilation directory for all include files, and for
7780 all files from which C is generated (like yacc and lex sources). This
7781 greatly improves GDB's ability to find yacc/lex sources, and include files,
7782 especially if you are debugging your program from a directory different from
7783 the one that contains your sources.
7785 We also fixed a bug which caused difficulty with listing and setting
7786 breakpoints in include files which contain C code. (In the past, you had to
7787 try twice in order to list an include file that you hadn't looked at before.)
7789 * Interesting infernals change
7791 GDB now deals with arbitrary numbers of sections, where the symbols for each
7792 section must be relocated relative to that section's landing place in the
7793 target's address space. This work was needed to support ELF with embedded
7794 stabs used by Solaris-2.0.
7796 * Bug fixes (of course!)
7798 There have been loads of fixes for the following things:
7799 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7800 i960, stabs, DOS(GO32), procfs, etc...
7802 See the ChangeLog for details.
7804 *** Changes in GDB-4.5:
7806 * New machines supported (host and target)
7808 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7810 SGI Irix-4.x mips-sgi-irix4 or iris4
7812 * New malloc package
7814 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7815 Mmalloc is capable of handling multiple heaps of memory. It is also
7816 capable of saving a heap to a file, and then mapping it back in later.
7817 This can be used to greatly speedup the startup of GDB by using a
7818 pre-parsed symbol table which lives in a mmalloc managed heap. For
7819 more details, please read mmalloc/mmalloc.texi.
7823 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7824 'help info proc' for details.
7826 * MIPS ecoff symbol table format
7828 The code that reads MIPS symbol table format is now supported on all hosts.
7829 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7832 * File name changes for MS-DOS
7834 Many files in the config directories have been renamed to make it easier to
7835 support GDB on MS-DOSe systems (which have very restrictive file name
7836 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7837 environment) is close to working but has some remaining problems. Note
7838 that debugging of DOS programs is not supported, due to limitations
7839 in the ``operating system'', but it can be used to host cross-debugging.
7841 * Cross byte order fixes
7843 Many fixes have been made to support cross debugging of Sparc and MIPS
7844 targets from hosts whose byte order differs.
7846 * New -mapped and -readnow options
7848 If memory-mapped files are available on your system through the 'mmap'
7849 system call, you can use the -mapped option on the `file' or
7850 `symbol-file' commands to cause GDB to write the symbols from your
7851 program into a reusable file. If the program you are debugging is
7852 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7853 Future GDB debugging sessions will notice the presence of this file,
7854 and will quickly map in symbol information from it, rather than reading
7855 the symbol table from the executable program. Using the '-mapped'
7856 option in a GDB `file' or `symbol-file' command has the same effect as
7857 starting GDB with the '-mapped' command-line option.
7859 You can cause GDB to read the entire symbol table immediately by using
7860 the '-readnow' option with any of the commands that load symbol table
7861 information (or on the GDB command line). This makes the command
7862 slower, but makes future operations faster.
7864 The -mapped and -readnow options are typically combined in order to
7865 build a `fred.syms' file that contains complete symbol information.
7866 A simple GDB invocation to do nothing but build a `.syms' file for future
7869 gdb -batch -nx -mapped -readnow programname
7871 The `.syms' file is specific to the host machine on which GDB is run.
7872 It holds an exact image of GDB's internal symbol table. It cannot be
7873 shared across multiple host platforms.
7875 * longjmp() handling
7877 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7878 siglongjmp() without losing control. This feature has not yet been ported to
7879 all systems. It currently works on many 386 platforms, all MIPS-based
7880 platforms (SGI, DECstation, etc), and Sun3/4.
7884 Preliminary work has been put in to support the new Solaris OS from Sun. At
7885 this time, it can control and debug processes, but it is not capable of
7890 As always, many many bug fixes. The major areas were with g++, and mipsread.
7891 People using the MIPS-based platforms should experience fewer mysterious
7892 crashes and trashed symbol tables.
7894 *** Changes in GDB-4.4:
7896 * New machines supported (host and target)
7898 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7900 BSD Reno on Vax vax-dec-bsd
7901 Ultrix on Vax vax-dec-ultrix
7903 * New machines supported (target)
7905 AMD 29000 embedded, using EBMON a29k-none-none
7909 GDB continues to improve its handling of C++. `References' work better.
7910 The demangler has also been improved, and now deals with symbols mangled as
7911 per the Annotated C++ Reference Guide.
7913 GDB also now handles `stabs' symbol information embedded in MIPS
7914 `ecoff' symbol tables. Since the ecoff format was not easily
7915 extensible to handle new languages such as C++, this appeared to be a
7916 good way to put C++ debugging info into MIPS binaries. This option
7917 will be supported in the GNU C compiler, version 2, when it is
7920 * New features for SVR4
7922 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7923 shared libraries. Debugging dynamically linked programs should present
7924 only minor differences from debugging statically linked programs.
7926 The `info proc' command will print out information about any process
7927 on an SVR4 system (including the one you are debugging). At the moment,
7928 it prints the address mappings of the process.
7930 If you bring up GDB on another SVR4 system, please send mail to
7931 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7933 * Better dynamic linking support in SunOS
7935 Reading symbols from shared libraries which contain debugging symbols
7936 now works properly. However, there remain issues such as automatic
7937 skipping of `transfer vector' code during function calls, which
7938 make it harder to debug code in a shared library, than to debug the
7939 same code linked statically.
7943 GDB is now using the latest `getopt' routines from the FSF. This
7944 version accepts the -- prefix for options with long names. GDB will
7945 continue to accept the old forms (-option and +option) as well.
7946 Various single letter abbreviations for options have been explicity
7947 added to the option table so that they won't get overshadowed in the
7948 future by other options that begin with the same letter.
7952 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7953 Many assorted bugs have been handled. Many more remain to be handled.
7954 See the various ChangeLog files (primarily in gdb and bfd) for details.
7957 *** Changes in GDB-4.3:
7959 * New machines supported (host and target)
7961 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7962 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7963 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7965 * Almost SCO Unix support
7967 We had hoped to support:
7968 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7969 (except for core file support), but we discovered very late in the release
7970 that it has problems with process groups that render gdb unusable. Sorry
7971 about that. I encourage people to fix it and post the fixes.
7973 * Preliminary ELF and DWARF support
7975 GDB can read ELF object files on System V Release 4, and can handle
7976 debugging records for C, in DWARF format, in ELF files. This support
7977 is preliminary. If you bring up GDB on another SVR4 system, please
7978 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7983 GDB now uses the latest `readline' library. One user-visible change
7984 is that two tabs will list possible command completions, which previously
7985 required typing M-? (meta-question mark, or ESC ?).
7989 The `stepi' bug that many of you noticed has been squashed.
7990 Many bugs in C++ have been handled. Many more remain to be handled.
7991 See the various ChangeLog files (primarily in gdb and bfd) for details.
7993 * State of the MIPS world (in case you wondered):
7995 GDB can understand the symbol tables emitted by the compilers
7996 supplied by most vendors of MIPS-based machines, including DEC. These
7997 symbol tables are in a format that essentially nobody else uses.
7999 Some versions of gcc come with an assembler post-processor called
8000 mips-tfile. This program is required if you want to do source-level
8001 debugging of gcc-compiled programs. I believe FSF does not ship
8002 mips-tfile with gcc version 1, but it will eventually come with gcc
8005 Debugging of g++ output remains a problem. g++ version 1.xx does not
8006 really support it at all. (If you're lucky, you should be able to get
8007 line numbers and stack traces to work, but no parameters or local
8008 variables.) With some work it should be possible to improve the
8011 When gcc version 2 is released, you will have somewhat better luck.
8012 However, even then you will get confusing results for inheritance and
8015 We will eventually provide full debugging of g++ output on
8016 DECstations. This will probably involve some kind of stabs-in-ecoff
8017 encapulation, but the details have not been worked out yet.
8020 *** Changes in GDB-4.2:
8022 * Improved configuration
8024 Only one copy of `configure' exists now, and it is not self-modifying.
8025 Porting BFD is simpler.
8029 The `step' and `next' commands now only stop at the first instruction
8030 of a source line. This prevents the multiple stops that used to occur
8031 in switch statements, for-loops, etc. `Step' continues to stop if a
8032 function that has debugging information is called within the line.
8036 Lots of small bugs fixed. More remain.
8038 * New host supported (not target)
8040 Intel 386 PC clone running Mach i386-none-mach
8043 *** Changes in GDB-4.1:
8045 * Multiple source language support
8047 GDB now has internal scaffolding to handle several source languages.
8048 It determines the type of each source file from its filename extension,
8049 and will switch expression parsing and number formatting to match the
8050 language of the function in the currently selected stack frame.
8051 You can also specifically set the language to be used, with
8052 `set language c' or `set language modula-2'.
8056 GDB now has preliminary support for the GNU Modula-2 compiler,
8057 currently under development at the State University of New York at
8058 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8059 continue through the fall of 1991 and into 1992.
8061 Other Modula-2 compilers are currently not supported, and attempting to
8062 debug programs compiled with them will likely result in an error as the
8063 symbol table is read. Feel free to work on it, though!
8065 There are hooks in GDB for strict type checking and range checking,
8066 in the `Modula-2 philosophy', but they do not currently work.
8070 GDB can now write to executable and core files (e.g. patch
8071 a variable's value). You must turn this switch on, specify
8072 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8073 by assigning a new value to a variable. Modifications take
8076 * Automatic SunOS shared library reading
8078 When you run your program, GDB automatically determines where its
8079 shared libraries (if any) have been loaded, and reads their symbols.
8080 The `share' command is no longer needed. This also works when
8081 examining core files.
8085 You can specify the number of lines that the `list' command shows.
8088 * New machines supported (host and target)
8090 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8091 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8092 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8094 * New hosts supported (not targets)
8096 IBM RT/PC: romp-ibm-aix or rtpc
8098 * New targets supported (not hosts)
8100 AMD 29000 embedded with COFF a29k-none-coff
8101 AMD 29000 embedded with a.out a29k-none-aout
8102 Ultracomputer remote kernel debug a29k-nyu-kern
8104 * New remote interfaces
8110 *** Changes in GDB-4.0:
8114 Wide output is wrapped at good places to make the output more readable.
8116 Gdb now supports cross-debugging from a host machine of one type to a
8117 target machine of another type. Communication with the target system
8118 is over serial lines. The ``target'' command handles connecting to the
8119 remote system; the ``load'' command will download a program into the
8120 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8121 also supports debugging of realtime processes running under VxWorks,
8122 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8123 stub on the target system.
8125 New CPUs supported include the AMD 29000 and Intel 960.
8127 GDB now reads object files and symbol tables via a ``binary file''
8128 library, which allows a single copy of GDB to debug programs of multiple
8129 object file types such as a.out and coff.
8131 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8132 refcard.dvi and refcard.ps are available to format it).
8135 * Control-Variable user interface simplified
8137 All variables that control the operation of the debugger can be set
8138 by the ``set'' command, and displayed by the ``show'' command.
8140 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8141 ``Show prompt'' produces the response:
8142 Gdb's prompt is new-gdb=>.
8144 What follows are the NEW set commands. The command ``help set'' will
8145 print a complete list of old and new set commands. ``help set FOO''
8146 will give a longer description of the variable FOO. ``show'' will show
8147 all of the variable descriptions and their current settings.
8149 confirm on/off: Enables warning questions for operations that are
8150 hard to recover from, e.g. rerunning the program while
8151 it is already running. Default is ON.
8153 editing on/off: Enables EMACS style command line editing
8154 of input. Previous lines can be recalled with
8155 control-P, the current line can be edited with control-B,
8156 you can search for commands with control-R, etc.
8159 history filename NAME: NAME is where the gdb command history
8160 will be stored. The default is .gdb_history,
8161 or the value of the environment variable
8164 history size N: The size, in commands, of the command history. The
8165 default is 256, or the value of the environment variable
8168 history save on/off: If this value is set to ON, the history file will
8169 be saved after exiting gdb. If set to OFF, the
8170 file will not be saved. The default is OFF.
8172 history expansion on/off: If this value is set to ON, then csh-like
8173 history expansion will be performed on
8174 command line input. The default is OFF.
8176 radix N: Sets the default radix for input and output. It can be set
8177 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8178 in the current radix, so "set radix 10" is always a no-op.
8180 height N: This integer value is the number of lines on a page. Default
8181 is 24, the current `stty rows'' setting, or the ``li#''
8182 setting from the termcap entry matching the environment
8185 width N: This integer value is the number of characters on a line.
8186 Default is 80, the current `stty cols'' setting, or the ``co#''
8187 setting from the termcap entry matching the environment
8190 Note: ``set screensize'' is obsolete. Use ``set height'' and
8191 ``set width'' instead.
8193 print address on/off: Print memory addresses in various command displays,
8194 such as stack traces and structure values. Gdb looks
8195 more ``symbolic'' if you turn this off; it looks more
8196 ``machine level'' with it on. Default is ON.
8198 print array on/off: Prettyprint arrays. New convenient format! Default
8201 print demangle on/off: Print C++ symbols in "source" form if on,
8204 print asm-demangle on/off: Same, for assembler level printouts
8207 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8210 * Support for Epoch Environment.
8212 The epoch environment is a version of Emacs v18 with windowing. One
8213 new command, ``inspect'', is identical to ``print'', except that if you
8214 are running in the epoch environment, the value is printed in its own
8218 * Support for Shared Libraries
8220 GDB can now debug programs and core files that use SunOS shared libraries.
8221 Symbols from a shared library cannot be referenced
8222 before the shared library has been linked with the program (this
8223 happens after you type ``run'' and before the function main() is entered).
8224 At any time after this linking (including when examining core files
8225 from dynamically linked programs), gdb reads the symbols from each
8226 shared library when you type the ``sharedlibrary'' command.
8227 It can be abbreviated ``share''.
8229 sharedlibrary REGEXP: Load shared object library symbols for files
8230 matching a unix regular expression. No argument
8231 indicates to load symbols for all shared libraries.
8233 info sharedlibrary: Status of loaded shared libraries.
8238 A watchpoint stops execution of a program whenever the value of an
8239 expression changes. Checking for this slows down execution
8240 tremendously whenever you are in the scope of the expression, but is
8241 quite useful for catching tough ``bit-spreader'' or pointer misuse
8242 problems. Some machines such as the 386 have hardware for doing this
8243 more quickly, and future versions of gdb will use this hardware.
8245 watch EXP: Set a watchpoint (breakpoint) for an expression.
8247 info watchpoints: Information about your watchpoints.
8249 delete N: Deletes watchpoint number N (same as breakpoints).
8250 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8251 enable N: Re-enables watchpoint number N (same as breakpoints).
8254 * C++ multiple inheritance
8256 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8259 * C++ exception handling
8261 Gdb now supports limited C++ exception handling. Besides the existing
8262 ability to breakpoint on an exception handler, gdb can breakpoint on
8263 the raising of an exception (before the stack is peeled back to the
8266 catch FOO: If there is a FOO exception handler in the dynamic scope,
8267 set a breakpoint to catch exceptions which may be raised there.
8268 Multiple exceptions (``catch foo bar baz'') may be caught.
8270 info catch: Lists all exceptions which may be caught in the
8271 current stack frame.
8274 * Minor command changes
8276 The command ``call func (arg, arg, ...)'' now acts like the print
8277 command, except it does not print or save a value if the function's result
8278 is void. This is similar to dbx usage.
8280 The ``up'' and ``down'' commands now always print the frame they end up
8281 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8282 frames without printing.
8284 * New directory command
8286 'dir' now adds directories to the FRONT of the source search path.
8287 The path starts off empty. Source files that contain debug information
8288 about the directory in which they were compiled can be found even
8289 with an empty path; Sun CC and GCC include this information. If GDB can't
8290 find your source file in the current directory, type "dir .".
8292 * Configuring GDB for compilation
8294 For normal use, type ``./configure host''. See README or gdb.texinfo
8297 GDB now handles cross debugging. If you are remotely debugging between
8298 two different machines, type ``./configure host -target=targ''.
8299 Host is the machine where GDB will run; targ is the machine
8300 where the program that you are debugging will run.