1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * Help and apropos commands will now show the documentation of a
7 command only once, even if that command has one or more aliases.
8 These commands now show the command name, then all of its aliases,
9 and finally the description of the command.
11 * 'help aliases' now shows only the user defined aliases. GDB predefined
12 aliases are shown together with their aliased command.
14 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
15 debugging information as well as source code.
17 When built with debuginfod, GDB can automatically query debuginfod
18 servers for the separate debug files and source code of the executable
21 To build GDB with debuginfod, pass --with-debuginfod to configure (this
22 requires libdebuginfod, the debuginfod client library).
24 debuginfod is distributed with elfutils, starting with version 0.178.
26 You can get the latest version from https://sourceware.org/elfutils.
28 * New features in the GDB remote stub, GDBserver
30 ** GDBserver is now supported on RISC-V GNU/Linux.
32 ** GDBserver no longer supports these host triplets:
43 i[34567]86-*-mingw32ce*
45 * Debugging MS-Windows processes now sets $_exitsignal when the
46 inferior is terminated by a signal, instead of setting $_exitcode.
48 * Multithreaded symbol loading has now been enabled by default on systems
49 that support it (see entry for GDB 9, below), providing faster
50 performance for programs with many symbols.
52 * The $_siginfo convenience variable now also works on Windows targets,
53 and will display the EXCEPTION_RECORD of the last handled exception.
55 * TUI windows can now be arranged horizontally.
57 * The command history filename can now be set to the empty string
58 either using 'set history filename' or by setting 'GDBHISTFILE=' in
59 the environment. The effect of setting this filename to the empty
60 string is that GDB will not try to load any previous command
63 * On Windows targets, it is now possible to debug 32-bit programs with a
68 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
69 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
70 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
71 running process, this new option indicates whether to detect
72 a mismatch between the current executable file loaded by GDB and the
73 executable file used to start the process. If 'ask', the default,
74 display a warning and ask the user whether to load the process
75 executable file; if 'warn', just display a warning; if 'off', don't
76 attempt to detect a mismatch.
78 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
79 Define a new TUI layout, specifying its name and the windows that
82 maintenance print xml-tdesc [FILE]
83 Prints the current target description as an XML document. If the
84 optional FILE is provided (which is an XML target description) then
85 the target description is read from FILE into GDB, and then
90 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
91 The alias command can now specify default args for an alias.
92 GDB automatically prepends the alias default args to the argument list
93 provided explicitly by the user.
94 For example, to have a backtrace with full details, you can define
96 'alias bt_ALL = backtrace -entry-values both -frame-arg all
97 -past-main -past-entry -full'.
98 Alias default arguments can also use a set of nested 'with' commands,
99 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
100 defines the alias pp10 that will pretty print a maximum of 10 elements
101 of the given expression (if the expression is an array).
105 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
109 ** gdb.register_window_type can be used to implement new TUI windows
112 ** Dynamic types can now be queried. gdb.Type has a new attribute,
113 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
114 field of a dynamic type may have None for its "bitpos" attribute
117 ** Commands written in Python can be in the "TUI" help class by
118 registering with the new constant gdb.COMMAND_TUI.
120 ** New method gdb.PendingFrame.architecture () to retrieve the
121 architecture of the pending frame.
123 ** New gdb.Architecture.registers method that returns a
124 gdb.RegisterDescriptorIterator object, an iterator that returns
125 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
126 way to query the registers available for an architecture.
128 ** New gdb.Architecture.register_groups method that returns a
129 gdb.RegisterGroupIterator object, an iterator that returns
130 gdb.RegisterGroup objects. The new RegisterGroup is a way to
131 discover the available register groups.
135 ** GDB can now be built with GNU Guile 2.2 in addition to 2.0.
137 ** Procedures 'memory-port-read-buffer-size',
138 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
139 and 'set-memory-port-write-buffer-size!' are deprecated. When
140 using Guile 2.2 and later, users who need to control the size of
141 a memory port's internal buffer can use the 'setvbuf' procedure.
145 * 'thread-exited' event is now available in the annotations interface.
147 * New built-in convenience variables $_gdb_major and $_gdb_minor
148 provide the GDB version. They are handy for conditionally using
149 features available only in or since specific GDB versions, in
150 scripts that should work error-free with many different versions,
151 such as in system-wide init files.
153 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
154 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
155 of the GDB settings and the GDB maintenance settings. They are handy
156 for changing the logic of user defined commands depending on the
157 current GDB settings.
159 * GDB now supports Thread Local Storage (TLS) variables on several
160 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
161 architectures require kernel changes. TLS is not yet supported for
162 amd64 and i386 process core dumps.
164 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
165 addresses that required unmasking are shown in the backtrace with the
168 * Two new convenience functions $_cimag and $_creal that extract the
169 imaginary and real parts respectively from complex numbers.
171 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
172 provide the exitcode or exit status of the shell commands launched by
173 GDB commands such as "shell", "pipe" and "make".
175 * The command define-prefix can now define user defined prefix commands.
176 User defined commands can now be defined using these user defined prefix
179 * Command names can now use the . character.
181 * The RX port now supports XML target descriptions.
183 * GDB now shows the Ada task names at more places, e.g. in task switching
186 * GDB can now be compiled with Python 3 on Windows.
188 * New convenience variable $_ada_exception holds the address of the
189 Ada exception being thrown. This is set by Ada-related catchpoints.
191 * GDB can now place breakpoints on nested functions and subroutines in
192 Fortran code. The '::' operator can be used between parent and
193 child scopes when placing breakpoints, for example:
195 (gdb) break outer_function::inner_function
197 The 'outer_function::' prefix is only needed if 'inner_function' is
198 not visible in the current scope.
200 * In addition to the system-wide gdbinit file, if configured with
201 --with-system-gdbinit-dir, GDB will now also load files in that directory
202 as system gdbinit files, unless the -nx or -n flag is provided. Files
203 with extensions .gdb, .py and .scm are supported as long as GDB was
204 compiled with support for that language.
206 * GDB now supports multithreaded symbol loading for higher performance.
207 This feature is still in testing, so it is disabled by default. You
208 can turn it on using 'maint set worker-threads unlimited'.
210 * Multi-target debugging support
212 GDB now supports debugging multiple target connections
213 simultaneously. For example, you can now have each inferior
214 connected to different remote servers running in different machines,
215 or have one inferior debugging a local native process, an inferior
216 debugging a core dump, etc.
218 This support is experimental and comes with some limitations -- you
219 can only resume multiple targets simultaneously if all targets
220 support non-stop mode, and all remote stubs or servers must support
221 the same set of remote protocol features exactly. See also "info
222 connections" and "add-inferior -no-connection" below, and "maint set
223 target-non-stop" in the user manual.
227 ** The gdb.Value type has a new method 'format_string' which returns a
228 string representing the value. The formatting is controlled by the
229 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
230 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
231 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
233 ** gdb.Type has a new property 'objfile' which returns the objfile the
236 ** The frame information printed by the python frame filtering code
237 is now consistent with what the 'backtrace' command prints when
238 there are no filters, or when the 'backtrace' '-no-filters' option
241 ** The new function gdb.lookup_static_symbol can be used to look up
242 symbols with static linkage.
244 ** The new function gdb.lookup_static_symbols can be used to look up
245 all static symbols with static linkage.
247 ** gdb.Objfile has new methods 'lookup_global_symbol' and
248 'lookup_static_symbol' to lookup a symbol from this objfile only.
250 ** gdb.Block now supports the dictionary syntax for accessing symbols in
251 this block (e.g. block['local_variable']).
255 | [COMMAND] | SHELL_COMMAND
256 | -d DELIM COMMAND DELIM SHELL_COMMAND
257 pipe [COMMAND] | SHELL_COMMAND
258 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
259 Executes COMMAND and sends its output to SHELL_COMMAND.
260 With no COMMAND, repeat the last executed command
261 and send its output to SHELL_COMMAND.
263 define-prefix COMMAND
264 Define or mark a command as a user-defined prefix command.
266 with SETTING [VALUE] [-- COMMAND]
267 w SETTING [VALUE] [-- COMMAND]
268 Temporarily set SETTING, run COMMAND, and restore SETTING.
269 Usage: with SETTING -- COMMAND
270 With no COMMAND, repeats the last executed command.
271 SETTING is any GDB setting you can change with the "set"
272 subcommands. For example, 'with language c -- print someobj'
273 temporarily switches to the C language in order to print someobj.
274 Settings can be combined: 'w lang c -- w print elements unlimited --
275 usercmd' switches to the C language and runs usercmd with no limit
276 of array elements to print.
278 maint with SETTING [VALUE] [-- COMMAND]
279 Like "with", but works with "maintenance set" settings.
281 set may-call-functions [on|off]
282 show may-call-functions
283 This controls whether GDB will attempt to call functions in
284 the program, such as with expressions in the print command. It
285 defaults to on. Calling functions in the program being debugged
286 can have undesired side effects. It is now possible to forbid
287 such function calls. If function calls are forbidden, GDB will throw
288 an error when a command (such as print expression) calls a function
291 set print finish [on|off]
293 This controls whether the `finish' command will display the value
294 that is returned by the current function. When `off', the value is
295 still entered into the value history, but it is not printed. The
300 Allows deeply nested structures to be simplified when printing by
301 replacing deeply nested parts (beyond the max-depth) with ellipses.
302 The default max-depth is 20, but this can be set to unlimited to get
303 the old behavior back.
305 set print raw-values [on|off]
306 show print raw-values
307 By default, GDB applies the enabled pretty printers when printing a
308 value. This allows to ignore the enabled pretty printers for a series
309 of commands. The default is 'off'.
311 set logging debugredirect [on|off]
312 By default, GDB debug output will go to both the terminal and the logfile.
313 Set if you want debug output to go only to the log file.
315 set style title foreground COLOR
316 set style title background COLOR
317 set style title intensity VALUE
318 Control the styling of titles.
320 set style highlight foreground COLOR
321 set style highlight background COLOR
322 set style highlight intensity VALUE
323 Control the styling of highlightings.
325 maint set worker-threads
326 maint show worker-threads
327 Control the number of worker threads that can be used by GDB. The
328 default is 0. "unlimited" lets GDB choose a number that is
329 reasonable. Currently worker threads are only used when demangling
330 the names of linker symbols.
332 set style tui-border foreground COLOR
333 set style tui-border background COLOR
334 Control the styling of TUI borders.
336 set style tui-active-border foreground COLOR
337 set style tui-active-border background COLOR
338 Control the styling of the active TUI border.
340 maint set test-settings KIND
341 maint show test-settings KIND
342 A set of commands used by the testsuite for exercising the settings
345 maint set tui-resize-message [on|off]
346 maint show tui-resize-message
347 Control whether GDB prints a message each time the terminal is
348 resized when in TUI mode. This is primarily useful for testing the
351 set print frame-info [short-location|location|location-and-address
352 |source-and-location|source-line|auto]
353 show print frame-info
354 This controls what frame information is printed by the commands printing
355 a frame. This setting will e.g. influence the behaviour of 'backtrace',
356 'frame', 'stepi'. The python frame filtering also respect this setting.
357 The 'backtrace' '-frame-info' option can override this global setting.
359 set tui compact-source
360 show tui compact-source
362 Enable the "compact" display mode for the TUI source window. The
363 compact display uses only as much space as is needed for the line
364 numbers in the current file, and only a single space to separate the
365 line numbers from the source.
367 info modules [-q] [REGEXP]
368 Return a list of Fortran modules matching REGEXP, or all modules if
371 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
372 Return a list of functions within all modules, grouped by module.
373 The list of functions can be restricted with the optional regular
374 expressions. MODULE_REGEXP matches against the module name,
375 TYPE_REGEXP matches against the function type signature, and REGEXP
376 matches against the function name.
378 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
379 Return a list of variables within all modules, grouped by module.
380 The list of variables can be restricted with the optional regular
381 expressions. MODULE_REGEXP matches against the module name,
382 TYPE_REGEXP matches against the variable type, and REGEXP matches
383 against the variable name.
385 set debug remote-packet-max-chars
386 show debug remote-packet-max-chars
387 Controls the number of characters to output in a remote packet when using
389 The default is 512 bytes.
392 Lists the target connections currently in use.
397 The "help" command uses the title style to enhance the
398 readibility of its output by styling the classes and
402 Similarly to "help", the "apropos" command also uses the
403 title style for the command names. "apropos" accepts now
404 a flag "-v" (verbose) to show the full documentation
405 of matching commands and to use the highlight style to mark
406 the documentation parts matching REGEXP.
410 The GDB printf and eval commands can now print C-style and Ada-style
411 string convenience variables without calling functions in the program.
412 This allows to do formatted printing of strings without having
413 a running inferior, or when debugging a core dump.
415 info sources [-dirname | -basename] [--] [REGEXP]
416 This command has now optional arguments to only print the files
417 whose names match REGEXP. The arguments -dirname and -basename
418 allow to restrict matching respectively to the dirname and basename
422 The "show style" and its subcommands are now styling
423 a style name in their output using its own style, to help
424 the user visualize the different styles.
426 set print frame-arguments
427 The new value 'presence' indicates to only indicate the presence of
428 arguments using ..., instead of printing argument names and values.
430 set print raw-frame-arguments
431 show print raw-frame-arguments
433 These commands replace the similarly-named "set/show print raw
434 frame-arguments" commands (now with a dash instead of a space). The
435 old commands are now deprecated and may be removed in a future
438 add-inferior [-no-connection]
439 The add-inferior command now supports a "-no-connection" flag that
440 makes the new inferior start with no target connection associated.
441 By default, the new inferior inherits the target connection of the
442 current inferior. See also "info connections".
445 This command's output now includes a new "Connection" column
446 indicating which target connection an inferior is bound to. See
447 "info connections" above.
449 maint test-options require-delimiter
450 maint test-options unknown-is-error
451 maint test-options unknown-is-operand
452 maint show test-options-completion-result
453 Commands used by the testsuite to validate the command options
456 focus, winheight, +, -, >, <
457 These commands are now case-sensitive.
459 * New command options, command completion
461 GDB now has a standard infrastructure to support dash-style command
462 options ('-OPT'). One benefit is that commands that use it can
463 easily support completion of command line arguments. Try "CMD
464 -[TAB]" or "help CMD" to find options supported by a command. Over
465 time, we intend to migrate most commands to this infrastructure. A
466 number of commands got support for new command options in this
469 ** The "print" and "compile print" commands now support a number of
470 options that allow overriding relevant global print settings as
471 set by "set print" subcommands:
475 -array-indexes [on|off]
476 -elements NUMBER|unlimited
481 -repeats NUMBER|unlimited
482 -static-members [on|off]
487 Note that because the "print"/"compile print" commands accept
488 arbitrary expressions which may look like options (including
489 abbreviations), if you specify any command option, then you must
490 use a double dash ("--") to mark the end of argument processing.
492 ** The "backtrace" command now supports a number of options that
493 allow overriding relevant global print settings as set by "set
494 backtrace" and "set print" subcommands:
496 -entry-values no|only|preferred|if-needed|both|compact|default
497 -frame-arguments all|scalars|none
498 -raw-frame-arguments [on|off]
499 -frame-info auto|source-line|location|source-and-location
500 |location-and-address|short-location
504 In addition, the full/no-filters/hide qualifiers are now also
505 exposed as command options too:
511 ** The "frame apply", "tfaas" and "faas" commands similarly now
512 support the following options:
517 ** The new "info sources" options -dirname and -basename options
518 are using the standard '-OPT' infrastructure.
520 All options above can also be abbreviated. The argument of boolean
521 (on/off) options can be 0/1 too, and also the argument is assumed
522 "on" if omitted. This allows writing compact command invocations,
525 (gdb) p -ra -p -o 0 -- *myptr
527 The above is equivalent to:
529 (gdb) print -raw-values -pretty -object off -- *myptr
531 ** The "info types" command now supports the '-q' flag to disable
532 printing of some header information in a similar fashion to "info
533 variables" and "info functions".
535 ** The "info variables", "info functions", and "whereis" commands
536 now take a '-n' flag that excludes non-debug symbols (symbols
537 from the symbol table, not from the debug info such as DWARF)
540 * Completion improvements
542 ** GDB can now complete the options of the "thread apply all" and
543 "taas" commands, and their "-ascending" option can now be
546 ** GDB can now complete the options of the "info threads", "info
547 functions", "info variables", "info locals", and "info args"
550 ** GDB can now complete the options of the "compile file" and
551 "compile code" commands. The "compile file" command now
552 completes on filenames.
554 ** GDB can now complete the backtrace command's
555 "full/no-filters/hide" qualifiers.
557 * In settings, you can now abbreviate "unlimited".
559 E.g., "set print elements u" is now equivalent to "set print
565 This lists all the possible completions for the rest of the line, if it
566 were to be given as a command itself. This is intended for use by MI
567 frontends in cases when separate CLI and MI channels cannot be used.
569 -catch-throw, -catch-rethrow, and -catch-catch
570 These can be used to catch C++ exceptions in a similar fashion to
571 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
573 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
574 These commands are the MI equivalent of the CLI commands 'info
575 functions', 'info types', and 'info variables' respectively.
577 -symbol-info-modules, this is the MI equivalent of the CLI 'info
580 -symbol-info-module-functions and -symbol-info-module-variables.
581 These commands are the MI equivalent of the CLI commands 'info
582 module functions' and 'info module variables'.
586 ** The default version of the MI interpreter is now 3 (-i=mi3).
588 ** The output of information about multi-location breakpoints (which is
589 syntactically incorrect in MI 2) has changed in MI 3. This affects
590 the following commands and events:
594 - =breakpoint-created
595 - =breakpoint-modified
597 The -fix-multi-location-breakpoint-output command can be used to enable
598 this behavior with previous MI versions.
600 ** Backtraces and frames include a new optional field addr_flags which is
601 given after the addr field. On AArch64 this contains PAC if the address
602 has been masked in the frame. On all other targets the field is not
607 The testsuite now creates the files gdb.cmd (containing the arguments
608 used to launch GDB) and gdb.in (containing all the commands sent to
609 GDB) in the output directory for each test script. Multiple invocations
610 are appended with .1, .2, .3 etc.
612 * Building GDB and GDBserver now requires GNU make >= 3.82.
614 Using another implementation of the make program or an earlier version of
615 GNU make to build GDB or GDBserver is not supported.
617 * Building GDB now requires GNU readline >= 7.0.
619 GDB now bundles GNU readline 8.0, but if you choose to use
620 --with-system-readline, only readline >= 7.0 can be used.
622 * The TUI SingleKey keymap is now named "SingleKey". This can be used
623 from .inputrc to bind keys in this keymap. This feature is only
624 available when gdb is built against GNU readline 8.0 or later.
626 * Removed targets and native configurations
628 GDB no longer supports debugging the Cell Broadband Engine. This includes
629 both debugging standalone Cell/B.E. SPU applications and integrated debugging
630 of Cell/B.E. applications that use both the PPU and SPU architectures.
636 * Removed targets and native configurations
638 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
641 *** Changes in GDB 8.3
643 * GDB and GDBserver now support access to additional registers on
644 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
647 * GDB now has experimental support for the compilation and injection of
648 C++ source code into the inferior. This beta release does not include
649 support for several language features, such as templates, constructors,
652 This feature requires GCC 7.1 or higher built with libcp1.so
655 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
656 can be passed using the '[ADDRESS]:PORT' notation, or the regular
657 'ADDRESS:PORT' method.
659 * DWARF index cache: GDB can now automatically save indices of DWARF
660 symbols on disk to speed up further loading of the same binaries.
662 * Ada task switching is now supported on aarch64-elf targets when
663 debugging a program using the Ravenscar Profile. For more information,
664 see the "Tasking Support when using the Ravenscar Profile" section
665 in the GDB user manual.
667 * GDB in batch mode now exits with status 1 if the last command to be
670 * The RISC-V target now supports target descriptions.
672 * System call catchpoints now support system call aliases on FreeBSD.
673 When the ABI of a system call changes in FreeBSD, this is
674 implemented by leaving a compatibility system call using the old ABI
675 at the existing number and allocating a new system call number for
676 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
677 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
678 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
679 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
680 so that a system call catchpoint for the 'kevent' system call will
681 catch invocations of both the 'kevent' and 'freebsd11_kevent'
682 binaries. This ensures that 'kevent' system calls are caught for
683 binaries using either the old or new ABIs.
685 * Terminal styling is now available for the CLI and the TUI. GNU
686 Source Highlight can additionally be used to provide styling of
687 source code snippets. See the "set style" commands, below, for more
690 * Removed support for old demangling styles arm, edg, gnu, hp and
695 set debug compile-cplus-types
696 show debug compile-cplus-types
697 Control the display of debug output about type conversion in the
698 C++ compile feature. Commands have no effect while compiling
703 Control whether debug output about files/functions skipping is
706 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
707 Apply a command to some frames.
708 FLAG arguments allow to control what output to produce and how to handle
709 errors raised when applying COMMAND to a frame.
712 Apply a command to all threads (ignoring errors and empty output).
713 Shortcut for 'thread apply all -s COMMAND'.
716 Apply a command to all frames (ignoring errors and empty output).
717 Shortcut for 'frame apply all -s COMMAND'.
720 Apply a command to all frames of all threads (ignoring errors and empty
722 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
724 maint set dwarf unwinders (on|off)
725 maint show dwarf unwinders
726 Control whether DWARF unwinders can be used.
729 Display a list of open files for a process.
733 Changes to the "frame", "select-frame", and "info frame" CLI commands.
734 These commands all now take a frame specification which
735 is either a frame level, or one of the keywords 'level', 'address',
736 'function', or 'view' followed by a parameter. Selecting a frame by
737 address, or viewing a frame outside the current backtrace now
738 requires the use of a keyword. Selecting a frame by level is
739 unchanged. The MI comment "-stack-select-frame" is unchanged.
741 target remote FILENAME
742 target extended-remote FILENAME
743 If FILENAME is a Unix domain socket, GDB will attempt to connect
744 to this socket instead of opening FILENAME as a character device.
746 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
747 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
748 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
749 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
750 These commands can now print only the searched entities
751 matching the provided regexp(s), giving a condition
752 on the entity names or entity types. The flag -q disables
753 printing headers or informations messages.
759 These commands now determine the syntax for the shown entities
760 according to the language chosen by `set language'. In particular,
761 `set language auto' means to automatically choose the language of
764 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
765 The 'thread apply' command accepts new FLAG arguments.
766 FLAG arguments allow to control what output to produce and how to handle
767 errors raised when applying COMMAND to a thread.
769 set tui tab-width NCHARS
770 show tui tab-width NCHARS
771 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
773 set style enabled [on|off]
775 Enable or disable terminal styling. Styling is enabled by default
776 on most hosts, but disabled by default when in batch mode.
778 set style sources [on|off]
780 Enable or disable source code styling. Source code styling is
781 enabled by default, but only takes effect if styling in general is
782 enabled, and if GDB was linked with GNU Source Highlight.
784 set style filename foreground COLOR
785 set style filename background COLOR
786 set style filename intensity VALUE
787 Control the styling of file names.
789 set style function foreground COLOR
790 set style function background COLOR
791 set style function intensity VALUE
792 Control the styling of function names.
794 set style variable foreground COLOR
795 set style variable background COLOR
796 set style variable intensity VALUE
797 Control the styling of variable names.
799 set style address foreground COLOR
800 set style address background COLOR
801 set style address intensity VALUE
802 Control the styling of addresses.
806 ** The '-data-disassemble' MI command now accepts an '-a' option to
807 disassemble the whole function surrounding the given program
808 counter value or function name. Support for this feature can be
809 verified by using the "-list-features" command, which should
810 contain "data-disassemble-a-option".
812 ** Command responses and notifications that include a frame now include
813 the frame's architecture in a new "arch" attribute.
815 * New native configurations
817 GNU/Linux/RISC-V riscv*-*-linux*
818 FreeBSD/riscv riscv*-*-freebsd*
822 GNU/Linux/RISC-V riscv*-*-linux*
824 CSKY GNU/LINUX csky*-*-linux
825 FreeBSD/riscv riscv*-*-freebsd*
827 GNU/Linux/OpenRISC or1k*-*-linux*
831 GDB no longer supports native debugging on versions of MS-Windows
836 ** GDB no longer supports Python versions less than 2.6.
838 ** The gdb.Inferior type has a new 'progspace' property, which is the program
839 space associated to that inferior.
841 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
842 of objfiles associated to that program space.
844 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
845 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
848 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
849 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
850 correct and did not work properly.
852 ** The gdb.Value type has a new constructor, which is used to construct a
853 gdb.Value from a Python buffer object and a gdb.Type.
859 Enable or disable the undefined behavior sanitizer. This is
860 disabled by default, but passing --enable-ubsan=yes or
861 --enable-ubsan=auto to configure will enable it. Enabling this can
862 cause a performance penalty. The undefined behavior sanitizer was
863 first introduced in GCC 4.9.
865 *** Changes in GDB 8.2
867 * The 'set disassembler-options' command now supports specifying options
870 * The 'symbol-file' command now accepts an '-o' option to add a relative
871 offset to all sections.
873 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
874 a relative offset to all sections, but it allows to override the load
875 address of individual sections using '-s'.
877 * The 'add-symbol-file' command no longer requires the second argument
878 (address of the text section).
880 * The endianness used with the 'set endian auto' mode in the absence of
881 an executable selected for debugging is now the last endianness chosen
882 either by one of the 'set endian big' and 'set endian little' commands
883 or by inferring from the last executable used, rather than the startup
886 * The pager now allows a "c" response, meaning to disable the pager
887 for the rest of the current command.
889 * The commands 'info variables/functions/types' now show the source line
890 numbers of symbol definitions when available.
892 * 'info proc' now works on running processes on FreeBSD systems and core
893 files created on FreeBSD systems.
895 * C expressions can now use _Alignof, and C++ expressions can now use
898 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
899 the vector length while the process is running.
905 Control display of debugging info regarding the FreeBSD native target.
907 set|show varsize-limit
908 This new setting allows the user to control the maximum size of Ada
909 objects being printed when those objects have a variable type,
910 instead of that maximum size being hardcoded to 65536 bytes.
912 set|show record btrace cpu
913 Controls the processor to be used for enabling errata workarounds for
916 maint check libthread-db
917 Run integrity checks on the current inferior's thread debugging
920 maint set check-libthread-db (on|off)
921 maint show check-libthread-db
922 Control whether to run integrity checks on inferior specific thread
923 debugging libraries as they are loaded. The default is not to
928 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
930 ** The commands attached to a breakpoint can be set by assigning to
931 the breakpoint's "commands" field.
933 ** gdb.execute can now execute multi-line gdb commands.
935 ** The new functions gdb.convenience_variable and
936 gdb.set_convenience_variable can be used to get and set the value
937 of convenience variables.
939 ** A gdb.Parameter will no longer print the "set" help text on an
940 ordinary "set"; instead by default a "set" will be silent unless
941 the get_set_string method returns a non-empty string.
945 RiscV ELF riscv*-*-elf
947 * Removed targets and native configurations
949 m88k running OpenBSD m88*-*-openbsd*
950 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
951 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
952 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
954 * Aarch64/Linux hardware watchpoints improvements
956 Hardware watchpoints on unaligned addresses are now properly
957 supported when running Linux kernel 4.10 or higher: read and access
958 watchpoints are no longer spuriously missed, and all watchpoints
959 lengths between 1 and 8 bytes are supported. On older kernels,
960 watchpoints set on unaligned addresses are no longer missed, with
961 the tradeoff that there is a possibility of false hits being
966 --enable-codesign=CERT
967 This can be used to invoke "codesign -s CERT" after building gdb.
968 This option is useful on macOS, where code signing is required for
969 gdb to work properly.
971 --disable-gdbcli has been removed
972 This is now silently accepted, but does nothing.
974 *** Changes in GDB 8.1
976 * GDB now supports dynamically creating arbitrary register groups specified
977 in XML target descriptions. This allows for finer grain grouping of
978 registers on systems with a large amount of registers.
980 * The 'ptype' command now accepts a '/o' flag, which prints the
981 offsets and sizes of fields in a struct, like the pahole(1) tool.
983 * New "--readnever" command line option instructs GDB to not read each
984 symbol file's symbolic debug information. This makes startup faster
985 but at the expense of not being able to perform symbolic debugging.
986 This option is intended for use cases where symbolic debugging will
987 not be used, e.g., when you only need to dump the debuggee's core.
989 * GDB now uses the GNU MPFR library, if available, to emulate target
990 floating-point arithmetic during expression evaluation when the target
991 uses different floating-point formats than the host. At least version
992 3.1 of GNU MPFR is required.
994 * GDB now supports access to the guarded-storage-control registers and the
995 software-based guarded-storage broadcast control registers on IBM z14.
997 * On Unix systems, GDB now supports transmitting environment variables
998 that are to be set or unset to GDBserver. These variables will
999 affect the environment to be passed to the remote inferior.
1001 To inform GDB of environment variables that are to be transmitted to
1002 GDBserver, use the "set environment" command. Only user set
1003 environment variables are sent to GDBserver.
1005 To inform GDB of environment variables that are to be unset before
1006 the remote inferior is started by the GDBserver, use the "unset
1007 environment" command.
1009 * Completion improvements
1011 ** GDB can now complete function parameters in linespecs and
1012 explicit locations without quoting. When setting breakpoints,
1013 quoting around functions names to help with TAB-completion is
1014 generally no longer necessary. For example, this now completes
1017 (gdb) b function(in[TAB]
1018 (gdb) b function(int)
1020 Related, GDB is no longer confused with completing functions in
1021 C++ anonymous namespaces:
1024 (gdb) b (anonymous namespace)::[TAB][TAB]
1025 (anonymous namespace)::a_function()
1026 (anonymous namespace)::b_function()
1028 ** GDB now has much improved linespec and explicit locations TAB
1029 completion support, that better understands what you're
1030 completing and offers better suggestions. For example, GDB no
1031 longer offers data symbols as possible completions when you're
1032 setting a breakpoint.
1034 ** GDB now TAB-completes label symbol names.
1036 ** The "complete" command now mimics TAB completion accurately.
1038 * New command line options (gcore)
1041 Dump all memory mappings.
1043 * Breakpoints on C++ functions are now set on all scopes by default
1045 By default, breakpoints on functions/methods are now interpreted as
1046 specifying all functions with the given name ignoring missing
1047 leading scopes (namespaces and classes).
1049 For example, assuming a C++ program with symbols named:
1054 both commands "break func()" and "break B::func()" set a breakpoint
1057 You can use the new flag "-qualified" to override this. This makes
1058 GDB interpret the specified function name as a complete
1059 fully-qualified name instead. For example, using the same C++
1060 program, the "break -q B::func" command sets a breakpoint on
1061 "B::func", only. A parameter has been added to the Python
1062 gdb.Breakpoint constructor to achieve the same result when creating
1063 a breakpoint from Python.
1065 * Breakpoints on functions marked with C++ ABI tags
1067 GDB can now set breakpoints on functions marked with C++ ABI tags
1068 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1069 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1071 Functions with a C++11 abi tag are demangled/displayed like this:
1073 function[abi:cxx11](int)
1076 You can now set a breakpoint on such functions simply as if they had
1079 (gdb) b function(int)
1081 Or if you need to disambiguate between tags, like:
1083 (gdb) b function[abi:other_tag](int)
1085 Tab completion was adjusted accordingly as well.
1089 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1090 gdb.new_thread are emitted. See the manual for further
1091 description of these.
1093 ** A new function, "gdb.rbreak" has been added to the Python API.
1094 This function allows the setting of a large number of breakpoints
1095 via a regex pattern in Python. See the manual for further details.
1097 ** Python breakpoints can now accept explicit locations. See the
1098 manual for a further description of this feature.
1101 * New features in the GDB remote stub, GDBserver
1103 ** GDBserver is now able to start inferior processes with a
1104 specified initial working directory.
1106 The user can set the desired working directory to be used from
1107 GDB using the new "set cwd" command.
1109 ** New "--selftest" command line option runs some GDBserver self
1110 tests. These self tests are disabled in releases.
1112 ** On Unix systems, GDBserver now does globbing expansion and variable
1113 substitution in inferior command line arguments.
1115 This is done by starting inferiors using a shell, like GDB does.
1116 See "set startup-with-shell" in the user manual for how to disable
1117 this from GDB when using "target extended-remote". When using
1118 "target remote", you can disable the startup with shell by using the
1119 new "--no-startup-with-shell" GDBserver command line option.
1121 ** On Unix systems, GDBserver now supports receiving environment
1122 variables that are to be set or unset from GDB. These variables
1123 will affect the environment to be passed to the inferior.
1125 * When catching an Ada exception raised with a message, GDB now prints
1126 the message in the catchpoint hit notification. In GDB/MI mode, that
1127 information is provided as an extra field named "exception-message"
1128 in the *stopped notification.
1130 * Trait objects can now be inspected When debugging Rust code. This
1131 requires compiler support which will appear in Rust 1.24.
1133 * New remote packets
1135 QEnvironmentHexEncoded
1136 Inform GDBserver of an environment variable that is to be passed to
1137 the inferior when starting it.
1140 Inform GDBserver of an environment variable that is to be unset
1141 before starting the remote inferior.
1144 Inform GDBserver that the environment should be reset (i.e.,
1145 user-set environment variables should be unset).
1148 Indicates whether the inferior must be started with a shell or not.
1151 Tell GDBserver that the inferior to be started should use a specific
1154 * The "maintenance print c-tdesc" command now takes an optional
1155 argument which is the file name of XML target description.
1157 * The "maintenance selftest" command now takes an optional argument to
1158 filter the tests to be run.
1160 * The "enable", and "disable" commands now accept a range of
1161 breakpoint locations, e.g. "enable 1.3-5".
1166 Set and show the current working directory for the inferior.
1168 set|show compile-gcc
1169 Set and show compilation command used for compiling and injecting code
1170 with the 'compile' commands.
1172 set debug separate-debug-file
1173 show debug separate-debug-file
1174 Control the display of debug output about separate debug file search.
1176 set dump-excluded-mappings
1177 show dump-excluded-mappings
1178 Control whether mappings marked with the VM_DONTDUMP flag should be
1179 dumped when generating a core file.
1181 maint info selftests
1182 List the registered selftests.
1185 Start the debugged program stopping at the first instruction.
1188 Control display of debugging messages related to OpenRISC targets.
1190 set|show print type nested-type-limit
1191 Set and show the limit of nesting level for nested types that the
1192 type printer will show.
1194 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1197 * Safer/improved support for debugging with no debug info
1199 GDB no longer assumes functions with no debug information return
1202 This means that GDB now refuses to call such functions unless you
1203 tell it the function's type, by either casting the call to the
1204 declared return type, or by casting the function to a function
1205 pointer of the right type, and calling that:
1207 (gdb) p getenv ("PATH")
1208 'getenv' has unknown return type; cast the call to its declared return type
1209 (gdb) p (char *) getenv ("PATH")
1210 $1 = 0x7fffffffe "/usr/local/bin:/"...
1211 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1212 $2 = 0x7fffffffe "/usr/local/bin:/"...
1214 Similarly, GDB no longer assumes that global variables with no debug
1215 info have type 'int', and refuses to print the variable's value
1216 unless you tell it the variable's type:
1219 'var' has unknown type; cast it to its declared type
1223 * New native configurations
1225 FreeBSD/aarch64 aarch64*-*-freebsd*
1226 FreeBSD/arm arm*-*-freebsd*
1230 FreeBSD/aarch64 aarch64*-*-freebsd*
1231 FreeBSD/arm arm*-*-freebsd*
1232 OpenRISC ELF or1k*-*-elf
1234 * Removed targets and native configurations
1236 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1238 *** Changes in GDB 8.0
1240 * GDB now supports access to the PKU register on GNU/Linux. The register is
1241 added by the Memory Protection Keys for Userspace feature which will be
1242 available in future Intel CPUs.
1244 * GDB now supports C++11 rvalue references.
1248 ** New functions to start, stop and access a running btrace recording.
1249 ** Rvalue references are now supported in gdb.Type.
1251 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1254 * Building GDB and GDBserver now requires a C++11 compiler.
1256 For example, GCC 4.8 or later.
1258 It is no longer possible to build GDB or GDBserver with a C
1259 compiler. The --disable-build-with-cxx configure option has been
1262 * Building GDB and GDBserver now requires GNU make >= 3.81.
1264 It is no longer supported to build GDB or GDBserver with another
1265 implementation of the make program or an earlier version of GNU make.
1267 * Native debugging on MS-Windows supports command-line redirection
1269 Command-line arguments used for starting programs on MS-Windows can
1270 now include redirection symbols supported by native Windows shells,
1271 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1272 as "run", "start", and "set args", as well as the corresponding MI
1275 * Support for thread names on MS-Windows.
1277 GDB now catches and handles the special exception that programs
1278 running on MS-Windows use to assign names to threads in the
1281 * Support for Java programs compiled with gcj has been removed.
1283 * User commands now accept an unlimited number of arguments.
1284 Previously, only up to 10 was accepted.
1286 * The "eval" command now expands user-defined command arguments.
1288 This makes it easier to process a variable number of arguments:
1293 eval "print $arg%d", $i
1298 * Target descriptions can now describe registers for sparc32 and sparc64.
1300 * GDB now supports DWARF version 5 (debug information format).
1301 Its .debug_names index is not yet supported.
1303 * New native configurations
1305 FreeBSD/mips mips*-*-freebsd
1309 Synopsys ARC arc*-*-elf32
1310 FreeBSD/mips mips*-*-freebsd
1312 * Removed targets and native configurations
1314 Alpha running FreeBSD alpha*-*-freebsd*
1315 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1320 Erases all the flash memory regions reported by the target.
1322 maint print arc arc-instruction address
1323 Print internal disassembler information about instruction at a given address.
1327 set disassembler-options
1328 show disassembler-options
1329 Controls the passing of target specific information to the disassembler.
1330 If it is necessary to specify more than one disassembler option then
1331 multiple options can be placed together into a comma separated list.
1332 The default value is the empty string. Currently, the only supported
1333 targets are ARM, PowerPC and S/390.
1338 Erases all the flash memory regions reported by the target. This is
1339 equivalent to the CLI command flash-erase.
1341 -file-list-shared-libraries
1342 List the shared libraries in the program. This is
1343 equivalent to the CLI command "info shared".
1346 Catchpoints stopping the program when Ada exceptions are
1347 handled. This is equivalent to the CLI command "catch handlers".
1349 *** Changes in GDB 7.12
1351 * GDB and GDBserver now build with a C++ compiler by default.
1353 The --enable-build-with-cxx configure option is now enabled by
1354 default. One must now explicitly configure with
1355 --disable-build-with-cxx in order to build with a C compiler. This
1356 option will be removed in a future release.
1358 * GDBserver now supports recording btrace without maintaining an active
1361 * GDB now supports a negative repeat count in the 'x' command to examine
1362 memory backward from the given address. For example:
1365 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1366 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1367 (gdb) x/-5i 0x0000000000400580
1368 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1369 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1370 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1371 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1372 0x40057b <main(int, char**)+25>:
1373 callq 0x400536 <Func1(int, char const*)>
1375 * Fortran: Support structures with fields of dynamic types and
1376 arrays of dynamic types.
1378 * The symbol dumping maintenance commands have new syntax.
1379 maint print symbols [-pc address] [--] [filename]
1380 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1381 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1382 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1383 maint print msymbols [-objfile objfile] [--] [filename]
1385 * GDB now supports multibit bitfields and enums in target register
1388 * New Python-based convenience function $_as_string(val), which returns
1389 the textual representation of a value. This function is especially
1390 useful to obtain the text label of an enum value.
1392 * Intel MPX bound violation handling.
1394 Segmentation faults caused by a Intel MPX boundary violation
1395 now display the kind of violation (upper or lower), the memory
1396 address accessed and the memory bounds, along with the usual
1397 signal received and code location.
1401 Program received signal SIGSEGV, Segmentation fault
1402 Upper bound violation while accessing address 0x7fffffffc3b3
1403 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1404 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1406 * Rust language support.
1407 GDB now supports debugging programs written in the Rust programming
1408 language. See https://www.rust-lang.org/ for more information about
1411 * Support for running interpreters on specified input/output devices
1413 GDB now supports a new mechanism that allows frontends to provide
1414 fully featured GDB console views, as a better alternative to
1415 building such views on top of the "-interpreter-exec console"
1416 command. See the new "new-ui" command below. With that command,
1417 frontends can now start GDB in the traditional command-line mode
1418 running in an embedded terminal emulator widget, and create a
1419 separate MI interpreter running on a specified i/o device. In this
1420 way, GDB handles line editing, history, tab completion, etc. in the
1421 console all by itself, and the GUI uses the separate MI interpreter
1422 for its own control and synchronization, invisible to the command
1425 * The "catch syscall" command catches groups of related syscalls.
1427 The "catch syscall" command now supports catching a group of related
1428 syscalls using the 'group:' or 'g:' prefix.
1433 skip -gfile file-glob-pattern
1434 skip -function function
1435 skip -rfunction regular-expression
1436 A generalized form of the skip command, with new support for
1437 glob-style file names and regular expressions for function names.
1438 Additionally, a file spec and a function spec may now be combined.
1440 maint info line-table REGEXP
1441 Display the contents of GDB's internal line table data structure.
1444 Run any GDB unit tests that were compiled in.
1447 Start a new user interface instance running INTERP as interpreter,
1448 using the TTY file for input/output.
1452 ** gdb.Breakpoint objects have a new attribute "pending", which
1453 indicates whether the breakpoint is pending.
1454 ** Three new breakpoint-related events have been added:
1455 gdb.breakpoint_created, gdb.breakpoint_modified, and
1456 gdb.breakpoint_deleted.
1458 signal-event EVENTID
1459 Signal ("set") the given MS-Windows event object. This is used in
1460 conjunction with the Windows JIT debugging (AeDebug) support, where
1461 the OS suspends a crashing process until a debugger can attach to
1462 it. Resuming the crashing process, in order to debug it, is done by
1463 signalling an event.
1465 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1466 was added in GDBserver, including JIT compiling fast tracepoint's
1467 conditional expression bytecode into native code.
1469 * Support for various remote target protocols and ROM monitors has
1472 target m32rsdi Remote M32R debugging over SDI
1473 target mips MIPS remote debugging protocol
1474 target pmon PMON ROM monitor
1475 target ddb NEC's DDB variant of PMON for Vr4300
1476 target rockhopper NEC RockHopper variant of PMON
1477 target lsi LSI variant of PMO
1479 * Support for tracepoints and fast tracepoints on powerpc-linux,
1480 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1481 including JIT compiling fast tracepoint's conditional expression
1482 bytecode into native code.
1484 * MI async record =record-started now includes the method and format used for
1485 recording. For example:
1487 =record-started,thread-group="i1",method="btrace",format="bts"
1489 * MI async record =thread-selected now includes the frame field. For example:
1491 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1495 Andes NDS32 nds32*-*-elf
1497 *** Changes in GDB 7.11
1499 * GDB now supports debugging kernel-based threads on FreeBSD.
1501 * Per-inferior thread numbers
1503 Thread numbers are now per inferior instead of global. If you're
1504 debugging multiple inferiors, GDB displays thread IDs using a
1505 qualified INF_NUM.THR_NUM form. For example:
1509 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1510 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1511 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1512 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1514 As consequence, thread numbers as visible in the $_thread
1515 convenience variable and in Python's InferiorThread.num attribute
1516 are no longer unique between inferiors.
1518 GDB now maintains a second thread ID per thread, referred to as the
1519 global thread ID, which is the new equivalent of thread numbers in
1520 previous releases. See also $_gthread below.
1522 For backwards compatibility, MI's thread IDs always refer to global
1525 * Commands that accept thread IDs now accept the qualified
1526 INF_NUM.THR_NUM form as well. For example:
1529 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1532 * In commands that accept a list of thread IDs, you can now refer to
1533 all threads of an inferior using a star wildcard. GDB accepts
1534 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1535 refer to all threads of the current inferior. For example, "info
1538 * You can use "info threads -gid" to display the global thread ID of
1541 * The new convenience variable $_gthread holds the global number of
1544 * The new convenience variable $_inferior holds the number of the
1547 * GDB now displays the ID and name of the thread that hit a breakpoint
1548 or received a signal, if your program is multi-threaded. For
1551 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1552 Thread 1 "main" received signal SIGINT, Interrupt.
1554 * Record btrace now supports non-stop mode.
1556 * Support for tracepoints on aarch64-linux was added in GDBserver.
1558 * The 'record instruction-history' command now indicates speculative execution
1559 when using the Intel Processor Trace recording format.
1561 * GDB now allows users to specify explicit locations, bypassing
1562 the linespec parser. This feature is also available to GDB/MI
1565 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1566 GDB now is able to debug both AArch64 applications and ARM applications
1569 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1570 including JIT compiling fast tracepoint's conditional expression bytecode
1573 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1575 * "info threads", "info inferiors", "info display", "info checkpoints"
1576 and "maint info program-spaces" now list the corresponding items in
1577 ascending ID order, for consistency with all other "info" commands.
1579 * In Ada, the overloads selection menu has been enhanced to display the
1580 parameter types and the return types for the matching overloaded subprograms.
1584 maint set target-non-stop (on|off|auto)
1585 maint show target-non-stop
1586 Control whether GDB targets always operate in non-stop mode even if
1587 "set non-stop" is "off". The default is "auto", meaning non-stop
1588 mode is enabled if supported by the target.
1590 maint set bfd-sharing
1591 maint show bfd-sharing
1592 Control the reuse of bfd objects.
1595 show debug bfd-cache
1596 Control display of debugging info regarding bfd caching.
1600 Control display of debugging info regarding FreeBSD threads.
1602 set remote multiprocess-extensions-packet
1603 show remote multiprocess-extensions-packet
1604 Set/show the use of the remote protocol multiprocess extensions.
1606 set remote thread-events
1607 show remote thread-events
1608 Set/show the use of thread create/exit events.
1610 set ada print-signatures on|off
1611 show ada print-signatures"
1612 Control whether parameter types and return types are displayed in overloads
1613 selection menus. It is activated (@code{on}) by default.
1617 Controls the maximum size of memory, in bytes, that GDB will
1618 allocate for value contents. Prevents incorrect programs from
1619 causing GDB to allocate overly large buffers. Default is 64k.
1621 * The "disassemble" command accepts a new modifier: /s.
1622 It prints mixed source+disassembly like /m with two differences:
1623 - disassembled instructions are now printed in program order, and
1624 - and source for all relevant files is now printed.
1625 The "/m" option is now considered deprecated: its "source-centric"
1626 output hasn't proved useful in practice.
1628 * The "record instruction-history" command accepts a new modifier: /s.
1629 It behaves exactly like /m and prints mixed source+disassembly.
1631 * The "set scheduler-locking" command supports a new mode "replay".
1632 It behaves like "off" in record mode and like "on" in replay mode.
1634 * Support for various ROM monitors has been removed:
1636 target dbug dBUG ROM monitor for Motorola ColdFire
1637 target picobug Motorola picobug monitor
1638 target dink32 DINK32 ROM monitor for PowerPC
1639 target m32r Renesas M32R/D ROM monitor
1640 target mon2000 mon2000 ROM monitor
1641 target ppcbug PPCBUG ROM monitor for PowerPC
1643 * Support for reading/writing memory and extracting values on architectures
1644 whose memory is addressable in units of any integral multiple of 8 bits.
1647 Allows to break when an Ada exception is handled.
1649 * New remote packets
1652 Indicates that an exec system call was executed.
1654 exec-events feature in qSupported
1655 The qSupported packet allows GDB to request support for exec
1656 events using the new 'gdbfeature' exec-event, and the qSupported
1657 response can contain the corresponding 'stubfeature'. Set and
1658 show commands can be used to display whether these features are enabled.
1661 Equivalent to interrupting with the ^C character, but works in
1664 thread created stop reason (T05 create:...)
1665 Indicates that the thread was just created and is stopped at entry.
1667 thread exit stop reply (w exitcode;tid)
1668 Indicates that the thread has terminated.
1671 Enables/disables thread create and exit event reporting. For
1672 example, this is used in non-stop mode when GDB stops a set of
1673 threads and synchronously waits for the their corresponding stop
1674 replies. Without exit events, if one of the threads exits, GDB
1675 would hang forever not knowing that it should no longer expect a
1676 stop for that same thread.
1679 Indicates that there are no resumed threads left in the target (all
1680 threads are stopped). The remote stub reports support for this stop
1681 reply to GDB's qSupported query.
1684 Enables/disables catching syscalls from the inferior process.
1685 The remote stub reports support for this packet to GDB's qSupported query.
1687 syscall_entry stop reason
1688 Indicates that a syscall was just called.
1690 syscall_return stop reason
1691 Indicates that a syscall just returned.
1693 * Extended-remote exec events
1695 ** GDB now has support for exec events on extended-remote Linux targets.
1696 For such targets with Linux kernels 2.5.46 and later, this enables
1697 follow-exec-mode and exec catchpoints.
1699 set remote exec-event-feature-packet
1700 show remote exec-event-feature-packet
1701 Set/show the use of the remote exec event feature.
1703 * Thread names in remote protocol
1705 The reply to qXfer:threads:read may now include a name attribute for each
1708 * Target remote mode fork and exec events
1710 ** GDB now has support for fork and exec events on target remote mode
1711 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1712 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1713 fork and exec catchpoints.
1715 * Remote syscall events
1717 ** GDB now has support for catch syscall on remote Linux targets,
1718 currently enabled on x86/x86_64 architectures.
1720 set remote catch-syscall-packet
1721 show remote catch-syscall-packet
1722 Set/show the use of the remote catch syscall feature.
1726 ** The -var-set-format command now accepts the zero-hexadecimal
1727 format. It outputs data in hexadecimal format with zero-padding on the
1732 ** gdb.InferiorThread objects have a new attribute "global_num",
1733 which refers to the thread's global thread ID. The existing
1734 "num" attribute now refers to the thread's per-inferior number.
1735 See "Per-inferior thread numbers" above.
1736 ** gdb.InferiorThread objects have a new attribute "inferior", which
1737 is the Inferior object the thread belongs to.
1739 *** Changes in GDB 7.10
1741 * Support for process record-replay and reverse debugging on aarch64*-linux*
1742 targets has been added. GDB now supports recording of A64 instruction set
1743 including advance SIMD instructions.
1745 * Support for Sun's version of the "stabs" debug file format has been removed.
1747 * GDB now honors the content of the file /proc/PID/coredump_filter
1748 (PID is the process ID) on GNU/Linux systems. This file can be used
1749 to specify the types of memory mappings that will be included in a
1750 corefile. For more information, please refer to the manual page of
1751 "core(5)". GDB also has a new command: "set use-coredump-filter
1752 on|off". It allows to set whether GDB will read the content of the
1753 /proc/PID/coredump_filter file when generating a corefile.
1755 * The "info os" command on GNU/Linux can now display information on
1757 "info os cpus" Listing of all cpus/cores on the system
1759 * GDB has two new commands: "set serial parity odd|even|none" and
1760 "show serial parity". These allows to set or show parity for the
1763 * The "info source" command now displays the producer string if it was
1764 present in the debug info. This typically includes the compiler version
1765 and may include things like its command line arguments.
1767 * The "info dll", an alias of the "info sharedlibrary" command,
1768 is now available on all platforms.
1770 * Directory names supplied to the "set sysroot" commands may be
1771 prefixed with "target:" to tell GDB to access shared libraries from
1772 the target system, be it local or remote. This replaces the prefix
1773 "remote:". The default sysroot has been changed from "" to
1774 "target:". "remote:" is automatically converted to "target:" for
1775 backward compatibility.
1777 * The system root specified by "set sysroot" will be prepended to the
1778 filename of the main executable (if reported to GDB as absolute by
1779 the operating system) when starting processes remotely, and when
1780 attaching to already-running local or remote processes.
1782 * GDB now supports automatic location and retrieval of executable
1783 files from remote targets. Remote debugging can now be initiated
1784 using only a "target remote" or "target extended-remote" command
1785 (no "set sysroot" or "file" commands are required). See "New remote
1788 * The "dump" command now supports verilog hex format.
1790 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1792 * On GNU/Linux, GDB and gdbserver are now able to access executable
1793 and shared library files without a "set sysroot" command when
1794 attaching to processes running in different mount namespaces from
1795 the debugger. This makes it possible to attach to processes in
1796 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1797 See "New remote packets" below.
1799 * The "tui reg" command now provides completion for all of the
1800 available register groups, including target specific groups.
1802 * The HISTSIZE environment variable is no longer read when determining
1803 the size of GDB's command history. GDB now instead reads the dedicated
1804 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1805 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1810 ** Memory ports can now be unbuffered.
1814 ** gdb.Objfile objects have a new attribute "username",
1815 which is the name of the objfile as specified by the user,
1816 without, for example, resolving symlinks.
1817 ** You can now write frame unwinders in Python.
1818 ** gdb.Type objects have a new method "optimized_out",
1819 returning optimized out gdb.Value instance of this type.
1820 ** gdb.Value objects have new methods "reference_value" and
1821 "const_value" which return a reference to the value and a
1822 "const" version of the value respectively.
1826 maint print symbol-cache
1827 Print the contents of the symbol cache.
1829 maint print symbol-cache-statistics
1830 Print statistics of symbol cache usage.
1832 maint flush-symbol-cache
1833 Flush the contents of the symbol cache.
1837 Start branch trace recording using Branch Trace Store (BTS) format.
1840 Evaluate expression by using the compiler and print result.
1844 Explicit commands for enabling and disabling tui mode.
1847 set mpx bound on i386 and amd64
1848 Support for bound table investigation on Intel MPX enabled applications.
1852 Start branch trace recording using Intel Processor Trace format.
1855 Print information about branch tracing internals.
1857 maint btrace packet-history
1858 Print the raw branch tracing data.
1860 maint btrace clear-packet-history
1861 Discard the stored raw branch tracing data.
1864 Discard all branch tracing data. It will be fetched and processed
1865 anew by the next "record" command.
1870 Renamed from "set debug dwarf2-die".
1871 show debug dwarf-die
1872 Renamed from "show debug dwarf2-die".
1874 set debug dwarf-read
1875 Renamed from "set debug dwarf2-read".
1876 show debug dwarf-read
1877 Renamed from "show debug dwarf2-read".
1879 maint set dwarf always-disassemble
1880 Renamed from "maint set dwarf2 always-disassemble".
1881 maint show dwarf always-disassemble
1882 Renamed from "maint show dwarf2 always-disassemble".
1884 maint set dwarf max-cache-age
1885 Renamed from "maint set dwarf2 max-cache-age".
1886 maint show dwarf max-cache-age
1887 Renamed from "maint show dwarf2 max-cache-age".
1889 set debug dwarf-line
1890 show debug dwarf-line
1891 Control display of debugging info regarding DWARF line processing.
1894 show max-completions
1895 Set the maximum number of candidates to be considered during
1896 completion. The default value is 200. This limit allows GDB
1897 to avoid generating large completion lists, the computation of
1898 which can cause the debugger to become temporarily unresponsive.
1900 set history remove-duplicates
1901 show history remove-duplicates
1902 Control the removal of duplicate history entries.
1904 maint set symbol-cache-size
1905 maint show symbol-cache-size
1906 Control the size of the symbol cache.
1908 set|show record btrace bts buffer-size
1909 Set and show the size of the ring buffer used for branch tracing in
1911 The obtained size may differ from the requested size. Use "info
1912 record" to see the obtained buffer size.
1914 set debug linux-namespaces
1915 show debug linux-namespaces
1916 Control display of debugging info regarding Linux namespaces.
1918 set|show record btrace pt buffer-size
1919 Set and show the size of the ring buffer used for branch tracing in
1920 Intel Processor Trace format.
1921 The obtained size may differ from the requested size. Use "info
1922 record" to see the obtained buffer size.
1924 maint set|show btrace pt skip-pad
1925 Set and show whether PAD packets are skipped when computing the
1928 * The command 'thread apply all' can now support new option '-ascending'
1929 to call its specified command for all threads in ascending order.
1931 * Python/Guile scripting
1933 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1934 special section named `.debug_gdb_scripts'.
1936 * New remote packets
1938 qXfer:btrace-conf:read
1939 Return the branch trace configuration for the current thread.
1941 Qbtrace-conf:bts:size
1942 Set the requested ring buffer size for branch tracing in BTS format.
1945 Enable Intel Processor Trace-based branch tracing for the current
1946 process. The remote stub reports support for this packet to GDB's
1949 Qbtrace-conf:pt:size
1950 Set the requested ring buffer size for branch tracing in Intel Processor
1954 Indicates a memory breakpoint instruction was executed, irrespective
1955 of whether it was GDB that planted the breakpoint or the breakpoint
1956 is hardcoded in the program. This is required for correct non-stop
1960 Indicates the target stopped for a hardware breakpoint. This is
1961 required for correct non-stop mode operation.
1964 Return information about files on the remote system.
1966 qXfer:exec-file:read
1967 Return the full absolute name of the file that was executed to
1968 create a process running on the remote system.
1971 Select the filesystem on which vFile: operations with filename
1972 arguments will operate. This is required for GDB to be able to
1973 access files on remote targets where the remote stub does not
1974 share a common filesystem with the inferior(s).
1977 Indicates that a fork system call was executed.
1980 Indicates that a vfork system call was executed.
1982 vforkdone stop reason
1983 Indicates that a vfork child of the specified process has executed
1984 an exec or exit, allowing the vfork parent to resume execution.
1986 fork-events and vfork-events features in qSupported
1987 The qSupported packet allows GDB to request support for fork and
1988 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1989 and the qSupported response can contain the corresponding
1990 'stubfeatures'. Set and show commands can be used to display
1991 whether these features are enabled.
1993 * Extended-remote fork events
1995 ** GDB now has support for fork events on extended-remote Linux
1996 targets. For targets with Linux kernels 2.5.60 and later, this
1997 enables follow-fork-mode and detach-on-fork for both fork and
1998 vfork, as well as fork and vfork catchpoints.
2000 * The info record command now shows the recording format and the
2001 branch tracing configuration for the current thread when using
2002 the btrace record target.
2003 For the BTS format, it shows the ring buffer size.
2005 * GDB now has support for DTrace USDT (Userland Static Defined
2006 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2008 * GDB now supports access to vector registers on S/390 GNU/Linux
2011 * Removed command line options
2013 -xdb HP-UX XDB compatibility mode.
2015 * Removed targets and native configurations
2017 HP/PA running HP-UX hppa*-*-hpux*
2018 Itanium running HP-UX ia64-*-hpux*
2020 * New configure options
2023 This configure option allows the user to build GDB with support for
2024 Intel Processor Trace (default: auto). This requires libipt.
2026 --with-libipt-prefix=PATH
2027 Specify the path to the version of libipt that GDB should use.
2028 $PATH/include should contain the intel-pt.h header and
2029 $PATH/lib should contain the libipt.so library.
2031 *** Changes in GDB 7.9.1
2035 ** Xmethods can now specify a result type.
2037 *** Changes in GDB 7.9
2039 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2043 ** You can now access frame registers from Python scripts.
2044 ** New attribute 'producer' for gdb.Symtab objects.
2045 ** gdb.Objfile objects have a new attribute "progspace",
2046 which is the gdb.Progspace object of the containing program space.
2047 ** gdb.Objfile objects have a new attribute "owner".
2048 ** gdb.Objfile objects have a new attribute "build_id",
2049 which is the build ID generated when the file was built.
2050 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2051 ** A new event "gdb.clear_objfiles" has been added, triggered when
2052 selecting a new file to debug.
2053 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2054 ** New function gdb.lookup_objfile.
2056 New events which are triggered when GDB modifies the state of the
2059 ** gdb.events.inferior_call_pre: Function call is about to be made.
2060 ** gdb.events.inferior_call_post: Function call has just been made.
2061 ** gdb.events.memory_changed: A memory location has been altered.
2062 ** gdb.events.register_changed: A register has been altered.
2064 * New Python-based convenience functions:
2066 ** $_caller_is(name [, number_of_frames])
2067 ** $_caller_matches(regexp [, number_of_frames])
2068 ** $_any_caller_is(name [, number_of_frames])
2069 ** $_any_caller_matches(regexp [, number_of_frames])
2071 * GDB now supports the compilation and injection of source code into
2072 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2073 to compile the source code to object code, and if successful, inject
2074 and execute that code within the current context of the inferior.
2075 Currently the C language is supported. The commands used to
2076 interface with this new feature are:
2078 compile code [-raw|-r] [--] [source code]
2079 compile file [-raw|-r] filename
2083 demangle [-l language] [--] name
2084 Demangle "name" in the specified language, or the current language
2085 if elided. This command is renamed from the "maint demangle" command.
2086 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2087 as "maint demangler-warning".
2089 queue-signal signal-name-or-number
2090 Queue a signal to be delivered to the thread when it is resumed.
2092 add-auto-load-scripts-directory directory
2093 Add entries to the list of directories from which to load auto-loaded
2096 maint print user-registers
2097 List all currently available "user" registers.
2099 compile code [-r|-raw] [--] [source code]
2100 Compile, inject, and execute in the inferior the executable object
2101 code produced by compiling the provided source code.
2103 compile file [-r|-raw] filename
2104 Compile and inject into the inferior the executable object code
2105 produced by compiling the source code stored in the filename
2108 * On resume, GDB now always passes the signal the program had stopped
2109 for to the thread the signal was sent to, even if the user changed
2110 threads before resuming. Previously GDB would often (but not
2111 always) deliver the signal to the thread that happens to be current
2114 * Conversely, the "signal" command now consistently delivers the
2115 requested signal to the current thread. GDB now asks for
2116 confirmation if the program had stopped for a signal and the user
2117 switched threads meanwhile.
2119 * "breakpoint always-inserted" modes "off" and "auto" merged.
2121 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2122 won't remove breakpoints from the target until all threads stop,
2123 even in non-stop mode. The "auto" mode has been removed, and "off"
2124 is now the default mode.
2128 set debug symbol-lookup
2129 show debug symbol-lookup
2130 Control display of debugging info regarding symbol lookup.
2134 ** The -list-thread-groups command outputs an exit-code field for
2135 inferiors that have exited.
2139 MIPS SDE mips*-sde*-elf*
2143 Support for these obsolete configurations has been removed.
2145 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2146 SGI Irix-5.x mips-*-irix5*
2147 SGI Irix-6.x mips-*-irix6*
2148 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2149 VAX running Ultrix vax-*-ultrix*
2151 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2152 and "assf"), have been removed. Use the "sharedlibrary" command, or
2153 its alias "share", instead.
2155 *** Changes in GDB 7.8
2157 * New command line options
2160 This is an alias for the --data-directory option.
2162 * GDB supports printing and modifying of variable length automatic arrays
2163 as specified in ISO C99.
2165 * The ARM simulator now supports instruction level tracing
2166 with or without disassembly.
2170 GDB now has support for scripting using Guile. Whether this is
2171 available is determined at configure time.
2172 Guile version 2.0 or greater is required.
2173 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2175 * New commands (for set/show, see "New options" below)
2179 Invoke CODE by passing it to the Guile interpreter.
2183 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2185 info auto-load guile-scripts [regexp]
2186 Print the list of automatically loaded Guile scripts.
2188 * The source command is now capable of sourcing Guile scripts.
2189 This feature is dependent on the debugger being built with Guile support.
2193 set print symbol-loading (off|brief|full)
2194 show print symbol-loading
2195 Control whether to print informational messages when loading symbol
2196 information for a file. The default is "full", but when debugging
2197 programs with large numbers of shared libraries the amount of output
2198 becomes less useful.
2200 set guile print-stack (none|message|full)
2201 show guile print-stack
2202 Show a stack trace when an error is encountered in a Guile script.
2204 set auto-load guile-scripts (on|off)
2205 show auto-load guile-scripts
2206 Control auto-loading of Guile script files.
2208 maint ada set ignore-descriptive-types (on|off)
2209 maint ada show ignore-descriptive-types
2210 Control whether the debugger should ignore descriptive types in Ada
2211 programs. The default is not to ignore the descriptive types. See
2212 the user manual for more details on descriptive types and the intended
2213 usage of this option.
2215 set auto-connect-native-target
2217 Control whether GDB is allowed to automatically connect to the
2218 native target for the run, attach, etc. commands when not connected
2219 to any target yet. See also "target native" below.
2221 set record btrace replay-memory-access (read-only|read-write)
2222 show record btrace replay-memory-access
2223 Control what memory accesses are allowed during replay.
2225 maint set target-async (on|off)
2226 maint show target-async
2227 This controls whether GDB targets operate in synchronous or
2228 asynchronous mode. Normally the default is asynchronous, if it is
2229 available; but this can be changed to more easily debug problems
2230 occurring only in synchronous mode.
2232 set mi-async (on|off)
2234 Control whether MI asynchronous mode is preferred. This supersedes
2235 "set target-async" of previous GDB versions.
2237 * "set target-async" is deprecated as a CLI option and is now an alias
2238 for "set mi-async" (only puts MI into async mode).
2240 * Background execution commands (e.g., "c&", "s&", etc.) are now
2241 possible ``out of the box'' if the target supports them. Previously
2242 the user would need to explicitly enable the possibility with the
2243 "set target-async on" command.
2245 * New features in the GDB remote stub, GDBserver
2247 ** New option --debug-format=option1[,option2,...] allows one to add
2248 additional text to each output. At present only timestamps
2249 are supported: --debug-format=timestamps.
2250 Timestamps can also be turned on with the
2251 "monitor set debug-format timestamps" command from GDB.
2253 * The 'record instruction-history' command now starts counting instructions
2254 at one. This also affects the instruction ranges reported by the
2255 'record function-call-history' command when given the /i modifier.
2257 * The command 'record function-call-history' supports a new modifier '/c' to
2258 indent the function names based on their call stack depth.
2259 The fields for the '/i' and '/l' modifier have been reordered.
2260 The source line range is now prefixed with 'at'.
2261 The instruction range is now prefixed with 'inst'.
2262 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2263 "record instruction-history" and "list" commands.
2265 * The ranges given as arguments to the 'record function-call-history' and
2266 'record instruction-history' commands are now inclusive.
2268 * The btrace record target now supports the 'record goto' command.
2269 For locations inside the execution trace, the back trace is computed
2270 based on the information stored in the execution trace.
2272 * The btrace record target supports limited reverse execution and replay.
2273 The target does not record data and therefore does not allow reading
2274 memory or registers.
2276 * The "catch syscall" command now works on s390*-linux* targets.
2278 * The "compare-sections" command is no longer specific to target
2279 remote. It now works with all targets.
2281 * All native targets are now consistently called "native".
2282 Consequently, the "target child", "target GNU", "target djgpp",
2283 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2284 commands have been replaced with "target native". The QNX/NTO port
2285 leaves the "procfs" target in place and adds a "native" target for
2286 consistency with other ports. The impact on users should be minimal
2287 as these commands previously either throwed an error, or were
2288 no-ops. The target's name is visible in the output of the following
2289 commands: "help target", "info target", "info files", "maint print
2292 * The "target native" command now connects to the native target. This
2293 can be used to launch native programs even when "set
2294 auto-connect-native-target" is set to off.
2296 * GDB now supports access to Intel MPX registers on GNU/Linux.
2298 * Support for Intel AVX-512 registers on GNU/Linux.
2299 Support displaying and modifying Intel AVX-512 registers
2300 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2302 * New remote packets
2304 qXfer:btrace:read's annex
2305 The qXfer:btrace:read packet supports a new annex 'delta' to read
2306 branch trace incrementally.
2310 ** Valid Python operations on gdb.Value objects representing
2311 structs/classes invoke the corresponding overloaded operators if
2313 ** New `Xmethods' feature in the Python API. Xmethods are
2314 additional methods or replacements for existing methods of a C++
2315 class. This feature is useful for those cases where a method
2316 defined in C++ source code could be inlined or optimized out by
2317 the compiler, making it unavailable to GDB.
2320 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2322 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2323 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2324 its alias "share", instead.
2326 * The commands "set remotebaud" and "show remotebaud" are no longer
2327 supported. Use "set serial baud" and "show serial baud" (respectively)
2332 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2333 target-async". The latter is left as a deprecated alias of the
2334 former for backward compatibility. If the target supports it,
2335 CLI background execution commands are now always possible by
2336 default, independently of whether the frontend stated a
2337 preference for asynchronous execution with "-gdb-set mi-async".
2338 Previously "-gdb-set target-async off" affected both MI execution
2339 commands and CLI execution commands.
2341 *** Changes in GDB 7.7
2343 * Improved support for process record-replay and reverse debugging on
2344 arm*-linux* targets. Support for thumb32 and syscall instruction
2345 recording has been added.
2347 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2349 * GDB now supports Fission DWP file format version 2.
2350 http://gcc.gnu.org/wiki/DebugFission
2352 * New convenience function "$_isvoid", to check whether an expression
2353 is void. A void expression is an expression where the type of the
2354 result is "void". For example, some convenience variables may be
2355 "void" when evaluated (e.g., "$_exitcode" before the execution of
2356 the program being debugged; or an undefined convenience variable).
2357 Another example, when calling a function whose return type is
2360 * The "maintenance print objfiles" command now takes an optional regexp.
2362 * The "catch syscall" command now works on arm*-linux* targets.
2364 * GDB now consistently shows "<not saved>" when printing values of
2365 registers the debug info indicates have not been saved in the frame
2366 and there's nowhere to retrieve them from
2367 (callee-saved/call-clobbered registers):
2372 (gdb) info registers rax
2375 Before, the former would print "<optimized out>", and the latter
2376 "*value not available*".
2378 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2383 ** Frame filters and frame decorators have been added.
2384 ** Temporary breakpoints are now supported.
2385 ** Line tables representation has been added.
2386 ** New attribute 'parent_type' for gdb.Field objects.
2387 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2388 ** New attribute 'name' for gdb.Type objects.
2392 Nios II ELF nios2*-*-elf
2393 Nios II GNU/Linux nios2*-*-linux
2394 Texas Instruments MSP430 msp430*-*-elf
2396 * Removed native configurations
2398 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2399 been removed. ELF variants of these configurations are kept supported.
2401 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2402 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2403 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2404 i[34567]86-*-openbsd3.[0-3]
2405 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2406 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2407 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2411 Like "catch throw", but catches a re-thrown exception.
2412 maint check-psymtabs
2413 Renamed from old "maint check-symtabs".
2415 Perform consistency checks on symtabs.
2416 maint expand-symtabs
2417 Expand symtabs matching an optional regexp.
2420 Display the details of GDB configure-time options.
2422 maint set|show per-command
2423 maint set|show per-command space
2424 maint set|show per-command time
2425 maint set|show per-command symtab
2426 Enable display of per-command gdb resource usage.
2428 remove-symbol-file FILENAME
2429 remove-symbol-file -a ADDRESS
2430 Remove a symbol file added via add-symbol-file. The file to remove
2431 can be identified by its filename or by an address that lies within
2432 the boundaries of this symbol file in memory.
2435 info exceptions REGEXP
2436 Display the list of Ada exceptions defined in the program being
2437 debugged. If provided, only the exceptions whose names match REGEXP
2442 set debug symfile off|on
2444 Control display of debugging info regarding reading symbol files and
2445 symbol tables within those files
2447 set print raw frame-arguments
2448 show print raw frame-arguments
2449 Set/show whether to print frame arguments in raw mode,
2450 disregarding any defined pretty-printers.
2452 set remote trace-status-packet
2453 show remote trace-status-packet
2454 Set/show the use of remote protocol qTStatus packet.
2458 Control display of debugging messages related to Nios II targets.
2462 Control whether target-assisted range stepping is enabled.
2464 set startup-with-shell
2465 show startup-with-shell
2466 Specifies whether Unix child processes are started via a shell or
2471 Use the target memory cache for accesses to the code segment. This
2472 improves performance of remote debugging (particularly disassembly).
2474 * You can now use a literal value 'unlimited' for options that
2475 interpret 0 or -1 as meaning "unlimited". E.g., "set
2476 trace-buffer-size unlimited" is now an alias for "set
2477 trace-buffer-size -1" and "set height unlimited" is now an alias for
2480 * The "set debug symtab-create" debugging option of GDB has been changed to
2481 accept a verbosity level. 0 means "off", 1 provides basic debugging
2482 output, and values of 2 or greater provides more verbose output.
2484 * New command-line options
2486 Display the details of GDB configure-time options.
2488 * The command 'tsave' can now support new option '-ctf' to save trace
2489 buffer in Common Trace Format.
2491 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2494 * GDB now implements the C++ 'typeid' operator.
2496 * The new convenience variable $_exception holds the exception being
2497 thrown or caught at an exception-related catchpoint.
2499 * The exception-related catchpoints, like "catch throw", now accept a
2500 regular expression which can be used to filter exceptions by type.
2502 * The new convenience variable $_exitsignal is automatically set to
2503 the terminating signal number when the program being debugged dies
2504 due to an uncaught signal.
2508 ** All MI commands now accept an optional "--language" option.
2509 Support for this feature can be verified by using the "-list-features"
2510 command, which should contain "language-option".
2512 ** The new command -info-gdb-mi-command allows the user to determine
2513 whether a GDB/MI command is supported or not.
2515 ** The "^error" result record returned when trying to execute an undefined
2516 GDB/MI command now provides a variable named "code" whose content is the
2517 "undefined-command" error code. Support for this feature can be verified
2518 by using the "-list-features" command, which should contain
2519 "undefined-command-error-code".
2521 ** The -trace-save MI command can optionally save trace buffer in Common
2524 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2526 ** The command -data-list-register-values now accepts an optional
2527 "--skip-unavailable" option. When used, only the available registers
2530 ** The new command -trace-frame-collected dumps collected variables,
2531 computed expressions, tvars, memory and registers in a traceframe.
2533 ** The commands -stack-list-locals, -stack-list-arguments and
2534 -stack-list-variables now accept an option "--skip-unavailable".
2535 When used, only the available locals or arguments are displayed.
2537 ** The -exec-run command now accepts an optional "--start" option.
2538 When used, the command follows the same semantics as the "start"
2539 command, stopping the program's execution at the start of its
2540 main subprogram. Support for this feature can be verified using
2541 the "-list-features" command, which should contain
2542 "exec-run-start-option".
2544 ** The new commands -catch-assert and -catch-exceptions insert
2545 catchpoints stopping the program when Ada exceptions are raised.
2547 ** The new command -info-ada-exceptions provides the equivalent of
2548 the new "info exceptions" command.
2550 * New system-wide configuration scripts
2551 A GDB installation now provides scripts suitable for use as system-wide
2552 configuration scripts for the following systems:
2556 * GDB now supports target-assigned range stepping with remote targets.
2557 This improves the performance of stepping source lines by reducing
2558 the number of control packets from/to GDB. See "New remote packets"
2561 * GDB now understands the element 'tvar' in the XML traceframe info.
2562 It has the id of the collected trace state variables.
2564 * On S/390 targets that provide the transactional-execution feature,
2565 the program interruption transaction diagnostic block (TDB) is now
2566 represented as a number of additional "registers" in GDB.
2568 * New remote packets
2572 The vCont packet supports a new 'r' action, that tells the remote
2573 stub to step through an address range itself, without GDB
2574 involvemement at each single-step.
2576 qXfer:libraries-svr4:read's annex
2577 The previously unused annex of the qXfer:libraries-svr4:read packet
2578 is now used to support passing an argument list. The remote stub
2579 reports support for this argument list to GDB's qSupported query.
2580 The defined arguments are "start" and "prev", used to reduce work
2581 necessary for library list updating, resulting in significant
2584 * New features in the GDB remote stub, GDBserver
2586 ** GDBserver now supports target-assisted range stepping. Currently
2587 enabled on x86/x86_64 GNU/Linux targets.
2589 ** GDBserver now adds element 'tvar' in the XML in the reply to
2590 'qXfer:traceframe-info:read'. It has the id of the collected
2591 trace state variables.
2593 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2596 * New 'z' formatter for printing and examining memory, this displays the
2597 value as hexadecimal zero padded on the left to the size of the type.
2599 * GDB can now use Windows x64 unwinding data.
2601 * The "set remotebaud" command has been replaced by "set serial baud".
2602 Similarly, "show remotebaud" has been replaced by "show serial baud".
2603 The "set remotebaud" and "show remotebaud" commands are still available
2604 to provide backward compatibility with older versions of GDB.
2606 *** Changes in GDB 7.6
2608 * Target record has been renamed to record-full.
2609 Record/replay is now enabled with the "record full" command.
2610 This also affects settings that are associated with full record/replay
2611 that have been moved from "set/show record" to "set/show record full":
2613 set|show record full insn-number-max
2614 set|show record full stop-at-limit
2615 set|show record full memory-query
2617 * A new record target "record-btrace" has been added. The new target
2618 uses hardware support to record the control-flow of a process. It
2619 does not support replaying the execution, but it implements the
2620 below new commands for investigating the recorded execution log.
2621 This new recording method can be enabled using:
2625 The "record-btrace" target is only available on Intel Atom processors
2626 and requires a Linux kernel 2.6.32 or later.
2628 * Two new commands have been added for record/replay to give information
2629 about the recorded execution without having to replay the execution.
2630 The commands are only supported by "record btrace".
2632 record instruction-history prints the execution history at
2633 instruction granularity
2635 record function-call-history prints the execution history at
2636 function granularity
2638 * New native configurations
2640 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2641 FreeBSD/powerpc powerpc*-*-freebsd
2642 x86_64/Cygwin x86_64-*-cygwin*
2643 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2647 ARM AArch64 aarch64*-*-elf
2648 ARM AArch64 GNU/Linux aarch64*-*-linux
2649 Lynx 178 PowerPC powerpc-*-lynx*178
2650 x86_64/Cygwin x86_64-*-cygwin*
2651 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2653 * If the configured location of system.gdbinit file (as given by the
2654 --with-system-gdbinit option at configure time) is in the
2655 data-directory (as specified by --with-gdb-datadir at configure
2656 time) or in one of its subdirectories, then GDB will look for the
2657 system-wide init file in the directory specified by the
2658 --data-directory command-line option.
2660 * New command line options:
2662 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2663 other initialization files, unlike -nx which disables all of them.
2665 * Removed command line options
2667 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2670 * The 'ptype' and 'whatis' commands now accept an argument to control
2673 * 'info proc' now works on some core files.
2677 ** Vectors can be created with gdb.Type.vector.
2679 ** Python's atexit.register now works in GDB.
2681 ** Types can be pretty-printed via a Python API.
2683 ** Python 3 is now supported (in addition to Python 2.4 or later)
2685 ** New class gdb.Architecture exposes GDB's internal representation
2686 of architecture in the Python API.
2688 ** New method Frame.architecture returns the gdb.Architecture object
2689 corresponding to the frame's architecture.
2691 * New Python-based convenience functions:
2693 ** $_memeq(buf1, buf2, length)
2694 ** $_streq(str1, str2)
2696 ** $_regex(str, regex)
2698 * The 'cd' command now defaults to using '~' (the home directory) if not
2701 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2702 default for GCC since November 2000.
2704 * The command 'forward-search' can now be abbreviated as 'fo'.
2706 * The command 'info tracepoints' can now display 'installed on target'
2707 or 'not installed on target' for each non-pending location of tracepoint.
2709 * New configure options
2711 --enable-libmcheck/--disable-libmcheck
2712 By default, development versions are built with -lmcheck on hosts
2713 that support it, in order to help track memory corruption issues.
2714 Release versions, on the other hand, are built without -lmcheck
2715 by default. The --enable-libmcheck/--disable-libmcheck configure
2716 options allow the user to override that default.
2717 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2718 This configure option allows the user to build GDB with
2719 libbabeltrace using which GDB can read Common Trace Format data.
2721 * New commands (for set/show, see "New options" below)
2724 Catch signals. This is similar to "handle", but allows commands and
2725 conditions to be attached.
2728 List the BFDs known to GDB.
2730 python-interactive [command]
2732 Start a Python interactive prompt, or evaluate the optional command
2733 and print the result of expressions.
2736 "py" is a new alias for "python".
2738 enable type-printer [name]...
2739 disable type-printer [name]...
2740 Enable or disable type printers.
2744 ** For the Renesas Super-H architecture, the "regs" command has been removed
2745 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2750 set print type methods (on|off)
2751 show print type methods
2752 Control whether method declarations are displayed by "ptype".
2753 The default is to show them.
2755 set print type typedefs (on|off)
2756 show print type typedefs
2757 Control whether typedef definitions are displayed by "ptype".
2758 The default is to show them.
2760 set filename-display basename|relative|absolute
2761 show filename-display
2762 Control the way in which filenames is displayed.
2763 The default is "relative", which preserves previous behavior.
2765 set trace-buffer-size
2766 show trace-buffer-size
2767 Request target to change the size of trace buffer.
2769 set remote trace-buffer-size-packet auto|on|off
2770 show remote trace-buffer-size-packet
2771 Control the use of the remote protocol `QTBuffer:size' packet.
2775 Control display of debugging messages related to ARM AArch64.
2778 set debug coff-pe-read
2779 show debug coff-pe-read
2780 Control display of debugging messages related to reading of COFF/PE
2785 Control display of debugging messages related to Mach-O symbols
2788 set debug notification
2789 show debug notification
2790 Control display of debugging info for async remote notification.
2794 ** Command parameter changes are now notified using new async record
2795 "=cmd-param-changed".
2796 ** Trace frame changes caused by command "tfind" are now notified using
2797 new async record "=traceframe-changed".
2798 ** The creation, deletion and modification of trace state variables
2799 are now notified using new async records "=tsv-created",
2800 "=tsv-deleted" and "=tsv-modified".
2801 ** The start and stop of process record are now notified using new
2802 async record "=record-started" and "=record-stopped".
2803 ** Memory changes are now notified using new async record
2805 ** The data-disassemble command response will include a "fullname" field
2806 containing the absolute file name when source has been requested.
2807 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2808 command, to allow pattern filling of memory areas.
2809 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2810 library load/unload events.
2811 ** The response to breakpoint commands and breakpoint async records
2812 includes an "installed" field containing a boolean state about each
2813 non-pending tracepoint location is whether installed on target or not.
2814 ** Output of the "-trace-status" command includes a "trace-file" field
2815 containing the name of the trace file being examined. This field is
2816 optional, and only present when examining a trace file.
2817 ** The "fullname" field is now always present along with the "file" field,
2818 even if the file cannot be found by GDB.
2820 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2821 You must have the LZMA library available when configuring GDB for this
2822 feature to be enabled. For more information, see:
2823 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2825 * New remote packets
2828 Set the size of trace buffer. The remote stub reports support for this
2829 packet to gdb's qSupported query.
2832 Enable Branch Trace Store (BTS)-based branch tracing for the current
2833 thread. The remote stub reports support for this packet to gdb's
2837 Disable branch tracing for the current thread. The remote stub reports
2838 support for this packet to gdb's qSupported query.
2841 Read the traced branches for the current thread. The remote stub
2842 reports support for this packet to gdb's qSupported query.
2844 *** Changes in GDB 7.5
2846 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2847 for more x32 ABI info.
2849 * GDB now supports access to MIPS DSP registers on Linux targets.
2851 * GDB now supports debugging microMIPS binaries.
2853 * The "info os" command on GNU/Linux can now display information on
2854 several new classes of objects managed by the operating system:
2855 "info os procgroups" lists process groups
2856 "info os files" lists file descriptors
2857 "info os sockets" lists internet-domain sockets
2858 "info os shm" lists shared-memory regions
2859 "info os semaphores" lists semaphores
2860 "info os msg" lists message queues
2861 "info os modules" lists loaded kernel modules
2863 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2864 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2865 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2866 options and inspect the probe arguments using the new $_probe_arg family
2867 of convenience variables. You can obtain more information about SystemTap
2868 in <http://sourceware.org/systemtap/>.
2870 * GDB now supports reversible debugging on ARM, it allows you to
2871 debug basic ARM and THUMB instructions, and provides
2872 record/replay support.
2874 * The option "symbol-reloading" has been deleted as it is no longer used.
2878 ** GDB commands implemented in Python can now be put in command class
2881 ** The "maint set python print-stack on|off" is now deleted.
2883 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2884 apply "flag enum"-style pretty-printing to any enum.
2886 ** gdb.lookup_symbol can now work when there is no current frame.
2888 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2889 the source at which the symbol was defined.
2891 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2892 method 'value'. The former indicates whether the symbol needs a
2893 frame in order to compute its value, and the latter computes the
2896 ** A new method 'referenced_value' on gdb.Value objects which can
2897 dereference pointer as well as C++ reference values.
2899 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2900 which return the global and static blocks (as gdb.Block objects),
2901 of the underlying symbol table, respectively.
2903 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2904 object associated with a PC value.
2906 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2907 of the address range occupied by code for the current source line.
2909 * Go language support.
2910 GDB now supports debugging programs written in the Go programming
2913 * GDBserver now supports stdio connections.
2914 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2916 * The binary "gdbtui" can no longer be built or installed.
2917 Use "gdb -tui" instead.
2919 * GDB will now print "flag" enums specially. A flag enum is one where
2920 all the enumerator values have no bits in common when pairwise
2921 "and"ed. When printing a value whose type is a flag enum, GDB will
2922 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2923 (gdb) print (enum E) 3
2926 * The filename part of a linespec will now match trailing components
2927 of a source file name. For example, "break gcc/expr.c:1000" will
2928 now set a breakpoint in build/gcc/expr.c, but not
2929 build/libcpp/expr.c.
2931 * The "info proc" and "generate-core-file" commands will now also
2932 work on remote targets connected to GDBserver on Linux.
2934 * The command "info catch" has been removed. It has been disabled
2935 since December 2007.
2937 * The "catch exception" and "catch assert" commands now accept
2938 a condition at the end of the command, much like the "break"
2939 command does. For instance:
2941 (gdb) catch exception Constraint_Error if Barrier = True
2943 Previously, it was possible to add a condition to such catchpoints,
2944 but it had to be done as a second step, after the catchpoint had been
2945 created, using the "condition" command.
2947 * The "info static-tracepoint-marker" command will now also work on
2948 native Linux targets with in-process agent.
2950 * GDB can now set breakpoints on inlined functions.
2952 * The .gdb_index section has been updated to include symbols for
2953 inlined functions. GDB will ignore older .gdb_index sections by
2954 default, which could cause symbol files to be loaded more slowly
2955 until their .gdb_index sections can be recreated. The new command
2956 "set use-deprecated-index-sections on" will cause GDB to use any older
2957 .gdb_index sections it finds. This will restore performance, but the
2958 ability to set breakpoints on inlined functions will be lost in symbol
2959 files with older .gdb_index sections.
2961 The .gdb_index section has also been updated to record more information
2962 about each symbol. This speeds up the "info variables", "info functions"
2963 and "info types" commands when used with programs having the .gdb_index
2964 section, as well as speeding up debugging with shared libraries using
2965 the .gdb_index section.
2967 * Ada support for GDB/MI Variable Objects has been added.
2969 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2974 ** New command -info-os is the MI equivalent of "info os".
2976 ** Output logs ("set logging" and related) now include MI output.
2980 ** "set use-deprecated-index-sections on|off"
2981 "show use-deprecated-index-sections on|off"
2982 Controls the use of deprecated .gdb_index sections.
2984 ** "catch load" and "catch unload" can be used to stop when a shared
2985 library is loaded or unloaded, respectively.
2987 ** "enable count" can be used to auto-disable a breakpoint after
2990 ** "info vtbl" can be used to show the virtual method tables for
2991 C++ and Java objects.
2993 ** "explore" and its sub commands "explore value" and "explore type"
2994 can be used to recursively explore values and types of
2995 expressions. These commands are available only if GDB is
2996 configured with '--with-python'.
2998 ** "info auto-load" shows status of all kinds of auto-loaded files,
2999 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3000 sequences of commands files, "info auto-load python-scripts"
3001 shows status of auto-loading Python script files,
3002 "info auto-load local-gdbinit" shows status of loading init file
3003 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3004 status of inferior specific thread debugging shared library loading.
3006 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3007 and "show auto-load-scripts" commands have been deprecated, use their
3008 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3009 and "show auto-load python-scripts" counterparts instead.
3011 ** "dprintf location,format,args..." creates a dynamic printf, which
3012 is basically a breakpoint that does a printf and immediately
3013 resumes your program's execution, so it is like a printf that you
3014 can insert dynamically at runtime instead of at compiletime.
3016 ** "set print symbol"
3018 Controls whether GDB attempts to display the symbol, if any,
3019 corresponding to addresses it prints. This defaults to "on", but
3020 you can set it to "off" to restore GDB's previous behavior.
3022 * Deprecated commands
3024 ** For the Renesas Super-H architecture, the "regs" command has been
3025 deprecated, and "info all-registers" should be used instead.
3029 Renesas RL78 rl78-*-elf
3030 HP OpenVMS ia64 ia64-hp-openvms*
3032 * GDBserver supports evaluation of breakpoint conditions. When
3033 support is advertised by GDBserver, GDB may be told to send the
3034 breakpoint conditions in bytecode form to GDBserver. GDBserver
3035 will only report the breakpoint trigger to GDB when its condition
3040 set mips compression
3041 show mips compression
3042 Select the compressed ISA encoding used in functions that have no symbol
3043 information available. The encoding can be set to either of:
3046 and is updated automatically from ELF file flags if available.
3048 set breakpoint condition-evaluation
3049 show breakpoint condition-evaluation
3050 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3051 GDBserver ("target"). Default option "auto" chooses the most efficient
3053 This option can improve debugger efficiency depending on the speed of the
3057 Disable auto-loading globally.
3060 Show auto-loading setting of all kinds of auto-loaded files.
3062 set auto-load gdb-scripts on|off
3063 show auto-load gdb-scripts
3064 Control auto-loading of GDB canned sequences of commands files.
3066 set auto-load python-scripts on|off
3067 show auto-load python-scripts
3068 Control auto-loading of Python script files.
3070 set auto-load local-gdbinit on|off
3071 show auto-load local-gdbinit
3072 Control loading of init file (.gdbinit) from current directory.
3074 set auto-load libthread-db on|off
3075 show auto-load libthread-db
3076 Control auto-loading of inferior specific thread debugging shared library.
3078 set auto-load scripts-directory <dir1>[:<dir2>...]
3079 show auto-load scripts-directory
3080 Set a list of directories from which to load auto-loaded scripts.
3081 Automatically loaded Python scripts and GDB scripts are located in one
3082 of the directories listed by this option.
3083 The delimiter (':' above) may differ according to the host platform.
3085 set auto-load safe-path <dir1>[:<dir2>...]
3086 show auto-load safe-path
3087 Set a list of directories from which it is safe to auto-load files.
3088 The delimiter (':' above) may differ according to the host platform.
3090 set debug auto-load on|off
3091 show debug auto-load
3092 Control display of debugging info for auto-loading the files above.
3094 set dprintf-style gdb|call|agent
3096 Control the way in which a dynamic printf is performed; "gdb"
3097 requests a GDB printf command, while "call" causes dprintf to call a
3098 function in the inferior. "agent" requests that the target agent
3099 (such as GDBserver) do the printing.
3101 set dprintf-function <expr>
3102 show dprintf-function
3103 set dprintf-channel <expr>
3104 show dprintf-channel
3105 Set the function and optional first argument to the call when using
3106 the "call" style of dynamic printf.
3108 set disconnected-dprintf on|off
3109 show disconnected-dprintf
3110 Control whether agent-style dynamic printfs continue to be in effect
3111 after GDB disconnects.
3113 * New configure options
3115 --with-auto-load-dir
3116 Configure default value for the 'set auto-load scripts-directory'
3117 setting above. It defaults to '$debugdir:$datadir/auto-load',
3118 $debugdir representing global debugging info directories (available
3119 via 'show debug-file-directory') and $datadir representing GDB's data
3120 directory (available via 'show data-directory').
3122 --with-auto-load-safe-path
3123 Configure default value for the 'set auto-load safe-path' setting
3124 above. It defaults to the --with-auto-load-dir setting.
3126 --without-auto-load-safe-path
3127 Set 'set auto-load safe-path' to '/', effectively disabling this
3130 * New remote packets
3132 z0/z1 conditional breakpoints extension
3134 The z0/z1 breakpoint insertion packets have been extended to carry
3135 a list of conditional expressions over to the remote stub depending on the
3136 condition evaluation mode. The use of this extension can be controlled
3137 via the "set remote conditional-breakpoints-packet" command.
3141 Specify the signals which the remote stub may pass to the debugged
3142 program without GDB involvement.
3144 * New command line options
3146 --init-command=FILE, -ix Like --command, -x but execute it
3147 before loading inferior.
3148 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3149 execute it before loading inferior.
3151 *** Changes in GDB 7.4
3153 * GDB now handles ambiguous linespecs more consistently; the existing
3154 FILE:LINE support has been expanded to other types of linespecs. A
3155 breakpoint will now be set on all matching locations in all
3156 inferiors, and locations will be added or removed according to
3159 * GDB now allows you to skip uninteresting functions and files when
3160 stepping with the "skip function" and "skip file" commands.
3162 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3163 and "show remote hardware-watchpoint-length-limit". These allows to
3164 set or show the maximum length limit (in bytes) of a remote
3165 target hardware watchpoint.
3167 This allows e.g. to use "unlimited" hardware watchpoints with the
3168 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3169 watchpoints are slower than real hardware watchpoints but are
3170 significantly faster than gdb software watchpoints.
3174 ** The register_pretty_printer function in module gdb.printing now takes
3175 an optional `replace' argument. If True, the new printer replaces any
3178 ** The "maint set python print-stack on|off" command has been
3179 deprecated and will be deleted in GDB 7.5.
3180 A new command: "set python print-stack none|full|message" has
3181 replaced it. Additionally, the default for "print-stack" is
3182 now "message", which just prints the error message without
3185 ** A prompt substitution hook (prompt_hook) is now available to the
3188 ** A new Python module, gdb.prompt has been added to the GDB Python
3189 modules library. This module provides functionality for
3190 escape sequences in prompts (used by set/show
3191 extended-prompt). These escape sequences are replaced by their
3192 corresponding value.
3194 ** Python commands and convenience-functions located in
3195 'data-directory'/python/gdb/command and
3196 'data-directory'/python/gdb/function are now automatically loaded
3199 ** Blocks now provide four new attributes. global_block and
3200 static_block will return the global and static blocks
3201 respectively. is_static and is_global are boolean attributes
3202 that indicate if the block is one of those two types.
3204 ** Symbols now provide the "type" attribute, the type of the symbol.
3206 ** The "gdb.breakpoint" function has been deprecated in favor of
3209 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3210 of a function. This class is based on the "finish" command
3211 available in the CLI.
3213 ** Type objects for struct and union types now allow access to
3214 the fields using standard Python dictionary (mapping) methods.
3215 For example, "some_type['myfield']" now works, as does
3216 "some_type.items()".
3218 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3221 ** A new function, "deep_items" has been added to the gdb.types
3222 module in the GDB Python modules library. This function returns
3223 an iterator over the fields of a struct or union type. Unlike
3224 the standard Python "iteritems" method, it will recursively traverse
3225 any anonymous fields.
3229 ** "*stopped" events can report several new "reason"s, such as
3232 ** Breakpoint changes are now notified using new async records, like
3233 "=breakpoint-modified".
3235 ** New command -ada-task-info.
3237 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3238 $sdir specifies the default system locations of shared libraries.
3239 $pdir specifies the directory where the libpthread used by the application
3242 GDB no longer looks in $sdir and $pdir after it has searched the directories
3243 mentioned in libthread-db-search-path. If you want to search those
3244 directories, they must be specified in libthread-db-search-path.
3245 The default value of libthread-db-search-path on GNU/Linux and Solaris
3246 systems is now "$sdir:$pdir".
3248 $pdir is not supported by gdbserver, it is currently ignored.
3249 $sdir is supported by gdbserver.
3251 * New configure option --with-iconv-bin.
3252 When using the internationalization support like the one in the GNU C
3253 library, GDB will invoke the "iconv" program to get a list of supported
3254 character sets. If this program lives in a non-standard location, one can
3255 use this option to specify where to find it.
3257 * When natively debugging programs on PowerPC BookE processors running
3258 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3259 watchpoints, which specify a mask in addition to an address to watch.
3260 The mask specifies that some bits of an address (the bits which are
3261 reset in the mask) should be ignored when matching the address accessed
3262 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3263 section in the user manual for more details.
3265 * The new option --once causes GDBserver to stop listening for connections once
3266 the first connection is made. The listening port used by GDBserver will
3267 become available after that.
3269 * New commands "info macros" and "alias" have been added.
3271 * New function parameters suffix @entry specifies value of function parameter
3272 at the time the function got called. Entry values are available only since
3278 "!" is now an alias of the "shell" command.
3279 Note that no space is needed between "!" and SHELL COMMAND.
3283 watch EXPRESSION mask MASK_VALUE
3284 The watch command now supports the mask argument which allows creation
3285 of masked watchpoints, if the current architecture supports this feature.
3287 info auto-load-scripts [REGEXP]
3288 This command was formerly named "maintenance print section-scripts".
3289 It is now generally useful and is no longer a maintenance-only command.
3291 info macro [-all] [--] MACRO
3292 The info macro command has new options `-all' and `--'. The first for
3293 printing all definitions of a macro. The second for explicitly specifying
3294 the end of arguments and the beginning of the macro name in case the macro
3295 name starts with a hyphen.
3297 collect[/s] EXPRESSIONS
3298 The tracepoint collect command now takes an optional modifier "/s"
3299 that directs it to dereference pointer-to-character types and
3300 collect the bytes of memory up to a zero byte. The behavior is
3301 similar to what you see when you use the regular print command on a
3302 string. An optional integer following the "/s" sets a bound on the
3303 number of bytes that will be collected.
3306 The trace start command now interprets any supplied arguments as a
3307 note to be recorded with the trace run, with an effect similar to
3308 setting the variable trace-notes.
3311 The trace stop command now interprets any arguments as a note to be
3312 mentioned along with the tstatus report that the trace was stopped
3313 with a command. The effect is similar to setting the variable
3316 * Tracepoints can now be enabled and disabled at any time after a trace
3317 experiment has been started using the standard "enable" and "disable"
3318 commands. It is now possible to start a trace experiment with no enabled
3319 tracepoints; GDB will display a warning, but will allow the experiment to
3320 begin, assuming that tracepoints will be enabled as needed while the trace
3323 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3324 locations with 4-byte instructions, when they were previously
3325 limited to locations with instructions of 5 bytes or longer.
3329 set debug dwarf2-read
3330 show debug dwarf2-read
3331 Turns on or off display of debugging messages related to reading
3332 DWARF debug info. The default is off.
3334 set debug symtab-create
3335 show debug symtab-create
3336 Turns on or off display of debugging messages related to symbol table
3337 creation. The default is off.
3340 show extended-prompt
3341 Set the GDB prompt, and allow escape sequences to be inserted to
3342 display miscellaneous information (see 'help set extended-prompt'
3343 for the list of sequences). This prompt (and any information
3344 accessed through the escape sequences) is updated every time the
3345 prompt is displayed.
3347 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3348 show print entry-values
3349 Set printing of frame argument values at function entry. In some cases
3350 GDB can determine the value of function argument which was passed by the
3351 function caller, even if the value was modified inside the called function.
3353 set debug entry-values
3354 show debug entry-values
3355 Control display of debugging info for determining frame argument values at
3356 function entry and virtual tail call frames.
3358 set basenames-may-differ
3359 show basenames-may-differ
3360 Set whether a source file may have multiple base names.
3361 (A "base name" is the name of a file with the directory part removed.
3362 Example: The base name of "/home/user/hello.c" is "hello.c".)
3363 If set, GDB will canonicalize file names (e.g., expand symlinks)
3364 before comparing them. Canonicalization is an expensive operation,
3365 but it allows the same file be known by more than one base name.
3366 If not set (the default), all source files are assumed to have just
3367 one base name, and gdb will do file name comparisons more efficiently.
3373 Set a user name and notes for the current and any future trace runs.
3374 This is useful for long-running and/or disconnected traces, to
3375 inform others (or yourself) as to who is running the trace, supply
3376 contact information, or otherwise explain what is going on.
3378 set trace-stop-notes
3379 show trace-stop-notes
3380 Set a note attached to the trace run, that is displayed when the
3381 trace has been stopped by a tstop command. This is useful for
3382 instance as an explanation, if you are stopping a trace run that was
3383 started by someone else.
3385 * New remote packets
3389 Dynamically enable a tracepoint in a started trace experiment.
3393 Dynamically disable a tracepoint in a started trace experiment.
3397 Set the user and notes of the trace run.
3401 Query the current status of a tracepoint.
3405 Query the minimum length of instruction at which a fast tracepoint may
3408 * Dcache size (number of lines) and line-size are now runtime-configurable
3409 via "set dcache line" and "set dcache line-size" commands.
3413 Texas Instruments TMS320C6x tic6x-*-*
3417 Renesas RL78 rl78-*-elf
3419 *** Changes in GDB 7.3.1
3421 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3423 *** Changes in GDB 7.3
3425 * GDB has a new command: "thread find [REGEXP]".
3426 It finds the thread id whose name, target id, or thread extra info
3427 matches the given regular expression.
3429 * The "catch syscall" command now works on mips*-linux* targets.
3431 * The -data-disassemble MI command now supports modes 2 and 3 for
3432 dumping the instruction opcodes.
3434 * New command line options
3436 -data-directory DIR Specify DIR as the "data-directory".
3437 This is mostly for testing purposes.
3439 * The "maint set python auto-load on|off" command has been renamed to
3440 "set auto-load-scripts on|off".
3442 * GDB has a new command: "set directories".
3443 It is like the "dir" command except that it replaces the
3444 source path list instead of augmenting it.
3446 * GDB now understands thread names.
3448 On GNU/Linux, "info threads" will display the thread name as set by
3449 prctl or pthread_setname_np.
3451 There is also a new command, "thread name", which can be used to
3452 assign a name internally for GDB to display.
3455 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3456 has been integrated into GDB.
3460 ** The function gdb.Write now accepts an optional keyword 'stream'.
3461 This keyword, when provided, will direct the output to either
3462 stdout, stderr, or GDB's logging output.
3464 ** Parameters can now be be sub-classed in Python, and in particular
3465 you may implement the get_set_doc and get_show_doc functions.
3466 This improves how Parameter set/show documentation is processed
3467 and allows for more dynamic content.
3469 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3470 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3471 have an is_valid method.
3473 ** Breakpoints can now be sub-classed in Python, and in particular
3474 you may implement a 'stop' function that is executed each time
3475 the inferior reaches that breakpoint.
3477 ** New function gdb.lookup_global_symbol looks up a global symbol.
3479 ** GDB values in Python are now callable if the value represents a
3480 function. For example, if 'some_value' represents a function that
3481 takes two integer parameters and returns a value, you can call
3482 that function like so:
3484 result = some_value (10,20)
3486 ** Module gdb.types has been added.
3487 It contains a collection of utilities for working with gdb.Types objects:
3488 get_basic_type, has_field, make_enum_dict.
3490 ** Module gdb.printing has been added.
3491 It contains utilities for writing and registering pretty-printers.
3492 New classes: PrettyPrinter, SubPrettyPrinter,
3493 RegexpCollectionPrettyPrinter.
3494 New function: register_pretty_printer.
3496 ** New commands "info pretty-printers", "enable pretty-printer" and
3497 "disable pretty-printer" have been added.
3499 ** gdb.parameter("directories") is now available.
3501 ** New function gdb.newest_frame returns the newest frame in the
3504 ** The gdb.InferiorThread class has a new "name" attribute. This
3505 holds the thread's name.
3507 ** Python Support for Inferior events.
3508 Python scripts can add observers to be notified of events
3509 occurring in the process being debugged.
3510 The following events are currently supported:
3511 - gdb.events.cont Continue event.
3512 - gdb.events.exited Inferior exited event.
3513 - gdb.events.stop Signal received, and Breakpoint hit events.
3517 ** GDB now puts template parameters in scope when debugging in an
3518 instantiation. For example, if you have:
3520 template<int X> int func (void) { return X; }
3522 then if you step into func<5>, "print X" will show "5". This
3523 feature requires proper debuginfo support from the compiler; it
3524 was added to GCC 4.5.
3526 ** The motion commands "next", "finish", "until", and "advance" now
3527 work better when exceptions are thrown. In particular, GDB will
3528 no longer lose control of the inferior; instead, the GDB will
3529 stop the inferior at the point at which the exception is caught.
3530 This functionality requires a change in the exception handling
3531 code that was introduced in GCC 4.5.
3533 * GDB now follows GCC's rules on accessing volatile objects when
3534 reading or writing target state during expression evaluation.
3535 One notable difference to prior behavior is that "print x = 0"
3536 no longer generates a read of x; the value of the assignment is
3537 now always taken directly from the value being assigned.
3539 * GDB now has some support for using labels in the program's source in
3540 linespecs. For instance, you can use "advance label" to continue
3541 execution to a label.
3543 * GDB now has support for reading and writing a new .gdb_index
3544 section. This section holds a fast index of DWARF debugging
3545 information and can be used to greatly speed up GDB startup and
3546 operation. See the documentation for `save gdb-index' for details.
3548 * The "watch" command now accepts an optional "-location" argument.
3549 When used, this causes GDB to watch the memory referred to by the
3550 expression. Such a watchpoint is never deleted due to it going out
3553 * GDB now supports thread debugging of core dumps on GNU/Linux.
3555 GDB now activates thread debugging using the libthread_db library
3556 when debugging GNU/Linux core dumps, similarly to when debugging
3557 live processes. As a result, when debugging a core dump file, GDB
3558 is now able to display pthread_t ids of threads. For example, "info
3559 threads" shows the same output as when debugging the process when it
3560 was live. In earlier releases, you'd see something like this:
3563 * 1 LWP 6780 main () at main.c:10
3565 While now you see this:
3568 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3570 It is also now possible to inspect TLS variables when debugging core
3573 When debugging a core dump generated on a machine other than the one
3574 used to run GDB, you may need to point GDB at the correct
3575 libthread_db library with the "set libthread-db-search-path"
3576 command. See the user manual for more details on this command.
3578 * When natively debugging programs on PowerPC BookE processors running
3579 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3580 which stop execution of the inferior whenever it executes an instruction
3581 at any address within the specified range. See the "PowerPC Embedded"
3582 section in the user manual for more details.
3584 * New features in the GDB remote stub, GDBserver
3586 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3587 and i686 LynxOS (version 5.x).
3589 ** GDBserver is now supported on Blackfin Linux.
3591 * New native configurations
3593 ia64 HP-UX ia64-*-hpux*
3597 Analog Devices, Inc. Blackfin Processor bfin-*
3599 * Ada task switching is now supported on sparc-elf targets when
3600 debugging a program using the Ravenscar Profile. For more information,
3601 see the "Tasking Support when using the Ravenscar Profile" section
3602 in the GDB user manual.
3604 * Guile support was removed.
3606 * New features in the GNU simulator
3608 ** The --map-info flag lists all known core mappings.
3610 ** CFI flashes may be simulated via the "cfi" device.
3612 *** Changes in GDB 7.2
3614 * Shared library support for remote targets by default
3616 When GDB is configured for a generic, non-OS specific target, like
3617 for example, --target=arm-eabi or one of the many *-*-elf targets,
3618 GDB now queries remote stubs for loaded shared libraries using the
3619 `qXfer:libraries:read' packet. Previously, shared library support
3620 was always disabled for such configurations.
3624 ** Argument Dependent Lookup (ADL)
3626 In C++ ADL lookup directs function search to the namespaces of its
3627 arguments even if the namespace has not been imported.
3637 Here the compiler will search for `foo' in the namespace of 'b'
3638 and find A::foo. GDB now supports this. This construct is commonly
3639 used in the Standard Template Library for operators.
3641 ** Improved User Defined Operator Support
3643 In addition to member operators, GDB now supports lookup of operators
3644 defined in a namespace and imported with a `using' directive, operators
3645 defined in the global scope, operators imported implicitly from an
3646 anonymous namespace, and the ADL operators mentioned in the previous
3648 GDB now also supports proper overload resolution for all the previously
3649 mentioned flavors of operators.
3651 ** static const class members
3653 Printing of static const class members that are initialized in the
3654 class definition has been fixed.
3656 * Windows Thread Information Block access.
3658 On Windows targets, GDB now supports displaying the Windows Thread
3659 Information Block (TIB) structure. This structure is visible either
3660 by using the new command `info w32 thread-information-block' or, by
3661 dereferencing the new convenience variable named `$_tlb', a
3662 thread-specific pointer to the TIB. This feature is also supported
3663 when remote debugging using GDBserver.
3665 * Static tracepoints
3667 Static tracepoints are calls in the user program into a tracing
3668 library. One such library is a port of the LTTng kernel tracer to
3669 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3670 When debugging with GDBserver, GDB now supports combining the GDB
3671 tracepoint machinery with such libraries. For example: the user can
3672 use GDB to probe a static tracepoint marker (a call from the user
3673 program into the tracing library) with the new "strace" command (see
3674 "New commands" below). This creates a "static tracepoint" in the
3675 breakpoint list, that can be manipulated with the same feature set
3676 as fast and regular tracepoints. E.g., collect registers, local and
3677 global variables, collect trace state variables, and define
3678 tracepoint conditions. In addition, the user can collect extra
3679 static tracepoint marker specific data, by collecting the new
3680 $_sdata internal variable. When analyzing the trace buffer, you can
3681 inspect $_sdata like any other variable available to GDB. For more
3682 information, see the "Tracepoints" chapter in GDB user manual. New
3683 remote packets have been defined to support static tracepoints, see
3684 the "New remote packets" section below.
3686 * Better reconstruction of tracepoints after disconnected tracing
3688 GDB will attempt to download the original source form of tracepoint
3689 definitions when starting a trace run, and then will upload these
3690 upon reconnection to the target, resulting in a more accurate
3691 reconstruction of the tracepoints that are in use on the target.
3695 You can now exercise direct control over the ways that GDB can
3696 affect your program. For instance, you can disallow the setting of
3697 breakpoints, so that the program can run continuously (assuming
3698 non-stop mode). In addition, the "observer" variable is available
3699 to switch all of the different controls; in observer mode, GDB
3700 cannot affect the target's behavior at all, which is useful for
3701 tasks like diagnosing live systems in the field.
3703 * The new convenience variable $_thread holds the number of the
3706 * New remote packets
3710 Return the address of the Windows Thread Information Block of a given thread.
3714 In response to several of the tracepoint packets, the target may now
3715 also respond with a number of intermediate `qRelocInsn' request
3716 packets before the final result packet, to have GDB handle
3717 relocating an instruction to execute at a different address. This
3718 is particularly useful for stubs that support fast tracepoints. GDB
3719 reports support for this feature in the qSupported packet.
3723 List static tracepoint markers in the target program.
3727 List static tracepoint markers at a given address in the target
3730 qXfer:statictrace:read
3732 Read the static trace data collected (by a `collect $_sdata'
3733 tracepoint action). The remote stub reports support for this packet
3734 to gdb's qSupported query.
3738 Send the current settings of GDB's permission flags.
3742 Send part of the source (textual) form of a tracepoint definition,
3743 which includes location, conditional, and action list.
3745 * The source command now accepts a -s option to force searching for the
3746 script in the source search path even if the script name specifies
3749 * New features in the GDB remote stub, GDBserver
3751 - GDBserver now support tracepoints (including fast tracepoints, and
3752 static tracepoints). The feature is currently supported by the
3753 i386-linux and amd64-linux builds. See the "Tracepoints support
3754 in gdbserver" section in the manual for more information.
3756 GDBserver JIT compiles the tracepoint's conditional agent
3757 expression bytecode into native code whenever possible for low
3758 overhead dynamic tracepoints conditionals. For such tracepoints,
3759 an expression that examines program state is evaluated when the
3760 tracepoint is reached, in order to determine whether to capture
3761 trace data. If the condition is simple and false, processing the
3762 tracepoint finishes very quickly and no data is gathered.
3764 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3765 for static tracepoints support.
3767 - GDBserver now supports x86_64 Windows 64-bit debugging.
3769 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3770 it understands register description.
3772 * The --batch flag now disables pagination and queries.
3774 * X86 general purpose registers
3776 GDB now supports reading/writing byte, word and double-word x86
3777 general purpose registers directly. This means you can use, say,
3778 $ah or $ax to refer, respectively, to the byte register AH and
3779 16-bit word register AX that are actually portions of the 32-bit
3780 register EAX or 64-bit register RAX.
3782 * The `commands' command now accepts a range of breakpoints to modify.
3783 A plain `commands' following a command that creates multiple
3784 breakpoints affects all the breakpoints set by that command. This
3785 applies to breakpoints set by `rbreak', and also applies when a
3786 single `break' command creates multiple breakpoints (e.g.,
3787 breakpoints on overloaded c++ functions).
3789 * The `rbreak' command now accepts a filename specification as part of
3790 its argument, limiting the functions selected by the regex to those
3791 in the specified file.
3793 * Support for remote debugging Windows and SymbianOS shared libraries
3794 from Unix hosts has been improved. Non Windows GDB builds now can
3795 understand target reported file names that follow MS-DOS based file
3796 system semantics, such as file names that include drive letters and
3797 use the backslash character as directory separator. This makes it
3798 possible to transparently use the "set sysroot" and "set
3799 solib-search-path" on Unix hosts to point as host copies of the
3800 target's shared libraries. See the new command "set
3801 target-file-system-kind" described below, and the "Commands to
3802 specify files" section in the user manual for more information.
3806 eval template, expressions...
3807 Convert the values of one or more expressions under the control
3808 of the string template to a command line, and call it.
3810 set target-file-system-kind unix|dos-based|auto
3811 show target-file-system-kind
3812 Set or show the assumed file system kind for target reported file
3815 save breakpoints <filename>
3816 Save all current breakpoint definitions to a file suitable for use
3817 in a later debugging session. To read the saved breakpoint
3818 definitions, use the `source' command.
3820 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3823 info static-tracepoint-markers
3824 Display information about static tracepoint markers in the target.
3826 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3827 Define a static tracepoint by probing a marker at the given
3828 function, line, address, or marker ID.
3832 Enable and disable observer mode.
3834 set may-write-registers on|off
3835 set may-write-memory on|off
3836 set may-insert-breakpoints on|off
3837 set may-insert-tracepoints on|off
3838 set may-insert-fast-tracepoints on|off
3839 set may-interrupt on|off
3840 Set individual permissions for GDB effects on the target. Note that
3841 some of these settings can have undesirable or surprising
3842 consequences, particularly when changed in the middle of a session.
3843 For instance, disabling the writing of memory can prevent
3844 breakpoints from being inserted, cause single-stepping to fail, or
3845 even crash your program, if you disable after breakpoints have been
3846 inserted. However, GDB should not crash.
3848 set record memory-query on|off
3849 show record memory-query
3850 Control whether to stop the inferior if memory changes caused
3851 by an instruction cannot be recorded.
3856 The disassemble command now supports "start,+length" form of two arguments.
3860 ** GDB now provides a new directory location, called the python directory,
3861 where Python scripts written for GDB can be installed. The location
3862 of that directory is <data-directory>/python, where <data-directory>
3863 is the GDB data directory. For more details, see section `Scripting
3864 GDB using Python' in the manual.
3866 ** The GDB Python API now has access to breakpoints, symbols, symbol
3867 tables, program spaces, inferiors, threads and frame's code blocks.
3868 Additionally, GDB Parameters can now be created from the API, and
3869 manipulated via set/show in the CLI.
3871 ** New functions gdb.target_charset, gdb.target_wide_charset,
3872 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3874 ** New exception gdb.GdbError.
3876 ** Pretty-printers are now also looked up in the current program space.
3878 ** Pretty-printers can now be individually enabled and disabled.
3880 ** GDB now looks for names of Python scripts to auto-load in a
3881 special section named `.debug_gdb_scripts', in addition to looking
3882 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3884 * Tracepoint actions were unified with breakpoint commands. In particular,
3885 there are no longer differences in "info break" output for breakpoints and
3886 tracepoints and the "commands" command can be used for both tracepoints and
3887 regular breakpoints.
3891 ARM Symbian arm*-*-symbianelf*
3893 * D language support.
3894 GDB now supports debugging programs written in the D programming
3897 * GDB now supports the extended ptrace interface for PowerPC which is
3898 available since Linux kernel version 2.6.34. This automatically enables
3899 any hardware breakpoints and additional hardware watchpoints available in
3900 the processor. The old ptrace interface exposes just one hardware
3901 watchpoint and no hardware breakpoints.
3903 * GDB is now able to use the Data Value Compare (DVC) register available on
3904 embedded PowerPC processors to implement in hardware simple watchpoint
3905 conditions of the form:
3907 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3909 This works in native GDB running on Linux kernels with the extended ptrace
3910 interface mentioned above.
3912 *** Changes in GDB 7.1
3916 ** Namespace Support
3918 GDB now supports importing of namespaces in C++. This enables the
3919 user to inspect variables from imported namespaces. Support for
3920 namepace aliasing has also been added. So, if a namespace is
3921 aliased in the current scope (e.g. namepace C=A; ) the user can
3922 print variables using the alias (e.g. (gdb) print C::x).
3926 All known bugs relating to the printing of virtual base class were
3927 fixed. It is now possible to call overloaded static methods using a
3932 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3933 and reinterpret_cast<> are now handled by the C++ expression parser.
3937 Xilinx MicroBlaze microblaze-*-*
3942 Xilinx MicroBlaze microblaze
3945 * Multi-program debugging.
3947 GDB now has support for multi-program (a.k.a. multi-executable or
3948 multi-exec) debugging. This allows for debugging multiple inferiors
3949 simultaneously each running a different program under the same GDB
3950 session. See "Debugging Multiple Inferiors and Programs" in the
3951 manual for more information. This implied some user visible changes
3952 in the multi-inferior support. For example, "info inferiors" now
3953 lists inferiors that are not running yet or that have exited
3954 already. See also "New commands" and "New options" below.
3956 * New tracing features
3958 GDB's tracepoint facility now includes several new features:
3960 ** Trace state variables
3962 GDB tracepoints now include support for trace state variables, which
3963 are variables managed by the target agent during a tracing
3964 experiment. They are useful for tracepoints that trigger each
3965 other, so for instance one tracepoint can count hits in a variable,
3966 and then a second tracepoint has a condition that is true when the
3967 count reaches a particular value. Trace state variables share the
3968 $-syntax of GDB convenience variables, and can appear in both
3969 tracepoint actions and condition expressions. Use the "tvariable"
3970 command to create, and "info tvariables" to view; see "Trace State
3971 Variables" in the manual for more detail.
3975 GDB now includes an option for defining fast tracepoints, which
3976 targets may implement more efficiently, such as by installing a jump
3977 into the target agent rather than a trap instruction. The resulting
3978 speedup can be by two orders of magnitude or more, although the
3979 tradeoff is that some program locations on some target architectures
3980 might not allow fast tracepoint installation, for instance if the
3981 instruction to be replaced is shorter than the jump. To request a
3982 fast tracepoint, use the "ftrace" command, with syntax identical to
3983 the regular trace command.
3985 ** Disconnected tracing
3987 It is now possible to detach GDB from the target while it is running
3988 a trace experiment, then reconnect later to see how the experiment
3989 is going. In addition, a new variable disconnected-tracing lets you
3990 tell the target agent whether to continue running a trace if the
3991 connection is lost unexpectedly.
3995 GDB now has the ability to save the trace buffer into a file, and
3996 then use that file as a target, similarly to you can do with
3997 corefiles. You can select trace frames, print data that was
3998 collected in them, and use tstatus to display the state of the
3999 tracing run at the moment that it was saved. To create a trace
4000 file, use "tsave <filename>", and to use it, do "target tfile
4003 ** Circular trace buffer
4005 You can ask the target agent to handle the trace buffer as a
4006 circular buffer, discarding the oldest trace frames to make room for
4007 newer ones, by setting circular-trace-buffer to on. This feature may
4008 not be available for all target agents.
4013 The disassemble command, when invoked with two arguments, now requires
4014 the arguments to be comma-separated.
4017 The info variables command now displays variable definitions. Files
4018 which only declare a variable are not shown.
4021 The source command is now capable of sourcing Python scripts.
4022 This feature is dependent on the debugger being build with Python
4025 Related to this enhancement is also the introduction of a new command
4026 "set script-extension" (see below).
4028 * New commands (for set/show, see "New options" below)
4030 record save [<FILENAME>]
4031 Save a file (in core file format) containing the process record
4032 execution log for replay debugging at a later time.
4034 record restore <FILENAME>
4035 Restore the process record execution log that was saved at an
4036 earlier time, for replay debugging.
4038 add-inferior [-copies <N>] [-exec <FILENAME>]
4041 clone-inferior [-copies <N>] [ID]
4042 Make a new inferior ready to execute the same program another
4043 inferior has loaded.
4048 maint info program-spaces
4049 List the program spaces loaded into GDB.
4051 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4052 show remote interrupt-sequence
4053 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4054 as the sequence to the remote target in order to interrupt the execution.
4055 Ctrl-C is a default. Some system prefers BREAK which is high level of
4056 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4057 Magic SysRq g. It is BREAK signal and character 'g'.
4059 set remote interrupt-on-connect [on | off]
4060 show remote interrupt-on-connect
4061 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4062 remote target when gdb connects to it. This is needed when you debug
4065 set remotebreak [on | off]
4067 Deprecated. Use "set/show remote interrupt-sequence" instead.
4069 tvariable $NAME [ = EXP ]
4070 Create or modify a trace state variable.
4073 List trace state variables and their values.
4075 delete tvariable $NAME ...
4076 Delete one or more trace state variables.
4079 Evaluate the given expressions without collecting anything into the
4080 trace buffer. (Valid in tracepoint actions only.)
4082 ftrace FN / FILE:LINE / *ADDR
4083 Define a fast tracepoint at the given function, line, or address.
4085 * New expression syntax
4087 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4088 GDB now parses 0b101010 identically with 42.
4092 set follow-exec-mode new|same
4093 show follow-exec-mode
4094 Control whether GDB reuses the same inferior across an exec call or
4095 creates a new one. This is useful to be able to restart the old
4096 executable after the inferior having done an exec call.
4098 set default-collect EXPR, ...
4099 show default-collect
4100 Define a list of expressions to be collected at each tracepoint.
4101 This is a useful way to ensure essential items are not overlooked,
4102 such as registers or a critical global variable.
4104 set disconnected-tracing
4105 show disconnected-tracing
4106 If set to 1, the target is instructed to continue tracing if it
4107 loses its connection to GDB. If 0, the target is to stop tracing
4110 set circular-trace-buffer
4111 show circular-trace-buffer
4112 If set to on, the target is instructed to use a circular trace buffer
4113 and discard the oldest trace frames instead of stopping the trace due
4114 to a full trace buffer. If set to off, the trace stops when the buffer
4115 fills up. Some targets may not support this.
4117 set script-extension off|soft|strict
4118 show script-extension
4119 If set to "off", the debugger does not perform any script language
4120 recognition, and all sourced files are assumed to be GDB scripts.
4121 If set to "soft" (the default), files are sourced according to
4122 filename extension, falling back to GDB scripts if the first
4124 If set to "strict", files are sourced according to filename extension.
4126 set ada trust-PAD-over-XVS on|off
4127 show ada trust-PAD-over-XVS
4128 If off, activate a workaround against a bug in the debugging information
4129 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4130 the GCC sources for more information about the GNAT encoding and
4131 PAD types in particular). It is always safe to set this option to
4132 off, but this introduces a slight performance penalty. The default
4135 * Python API Improvements
4137 ** GDB provides the new class gdb.LazyString. This is useful in
4138 some pretty-printing cases. The new method gdb.Value.lazy_string
4139 provides a simple way to create objects of this type.
4141 ** The fields returned by gdb.Type.fields now have an
4142 `is_base_class' attribute.
4144 ** The new method gdb.Type.range returns the range of an array type.
4146 ** The new method gdb.parse_and_eval can be used to parse and
4147 evaluate an expression.
4149 * New remote packets
4152 Define a trace state variable.
4155 Get the current value of a trace state variable.
4158 Set desired tracing behavior upon disconnection.
4161 Set the trace buffer to be linear or circular.
4164 Get data about the tracepoints currently in use.
4168 Process record now works correctly with hardware watchpoints.
4170 Multiple bug fixes have been made to the mips-irix port, making it
4171 much more reliable. In particular:
4172 - Debugging threaded applications is now possible again. Previously,
4173 GDB would hang while starting the program, or while waiting for
4174 the program to stop at a breakpoint.
4175 - Attaching to a running process no longer hangs.
4176 - An error occurring while loading a core file has been fixed.
4177 - Changing the value of the PC register now works again. This fixes
4178 problems observed when using the "jump" command, or when calling
4179 a function from GDB, or even when assigning a new value to $pc.
4180 - With the "finish" and "return" commands, the return value for functions
4181 returning a small array is now correctly printed.
4182 - It is now possible to break on shared library code which gets executed
4183 during a shared library init phase (code executed while executing
4184 their .init section). Previously, the breakpoint would have no effect.
4185 - GDB is now able to backtrace through the signal handler for
4186 non-threaded programs.
4188 PIE (Position Independent Executable) programs debugging is now supported.
4189 This includes debugging execution of PIC (Position Independent Code) shared
4190 libraries although for that, it should be possible to run such libraries as an
4193 *** Changes in GDB 7.0
4195 * GDB now has an interface for JIT compilation. Applications that
4196 dynamically generate code can create symbol files in memory and register
4197 them with GDB. For users, the feature should work transparently, and
4198 for JIT developers, the interface is documented in the GDB manual in the
4199 "JIT Compilation Interface" chapter.
4201 * Tracepoints may now be conditional. The syntax is as for
4202 breakpoints; either an "if" clause appended to the "trace" command,
4203 or the "condition" command is available. GDB sends the condition to
4204 the target for evaluation using the same bytecode format as is used
4205 for tracepoint actions.
4207 * The disassemble command now supports: an optional /r modifier, print the
4208 raw instructions in hex as well as in symbolic form, and an optional /m
4209 modifier to print mixed source+assembly.
4211 * Process record and replay
4213 In a architecture environment that supports ``process record and
4214 replay'', ``process record and replay'' target can record a log of
4215 the process execution, and replay it with both forward and reverse
4218 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4219 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4220 set execution-direction {forward|reverse}, for targets that support
4223 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4224 feature is available with a native GDB running on kernel version
4227 * GDB now has support for multi-byte and wide character sets on the
4228 target. Strings whose character type is wchar_t, char16_t, or
4229 char32_t are now correctly printed. GDB supports wide- and unicode-
4230 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4231 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4232 `printf'. This feature requires iconv to work properly; if your
4233 system does not have a working iconv, GDB can use GNU libiconv. See
4234 the installation instructions for more information.
4236 * GDB now supports automatic retrieval of shared library files from
4237 remote targets. To use this feature, specify a system root that begins
4238 with the `remote:' prefix, either via the `set sysroot' command or via
4239 the `--with-sysroot' configure-time option.
4241 * "info sharedlibrary" now takes an optional regex of libraries to show,
4242 and it now reports if a shared library has no debugging information.
4244 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4245 now complete on file names.
4247 * When completing in expressions, gdb will attempt to limit
4248 completions to allowable structure or union fields, where appropriate.
4249 For instance, consider:
4251 # struct example { int f1; double f2; };
4252 # struct example variable;
4255 If the user types TAB at the end of this command line, the available
4256 completions will be "f1" and "f2".
4258 * Inlined functions are now supported. They show up in backtraces, and
4259 the "step", "next", and "finish" commands handle them automatically.
4261 * GDB now supports the token-splicing (##) and stringification (#)
4262 operators when expanding macros. It also supports variable-arity
4265 * GDB now supports inspecting extra signal information, exported by
4266 the new $_siginfo convenience variable. The feature is currently
4267 implemented on linux ARM, i386 and amd64.
4269 * GDB can now display the VFP floating point registers and NEON vector
4270 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4271 can provide these registers (requires Linux 2.6.30 or later). Remote
4272 and simulator targets may also provide them.
4274 * New remote packets
4277 Search memory for a sequence of bytes.
4280 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4281 operation over reliable transport links. Use of this packet is
4282 controlled by the `set remote noack-packet' command.
4285 Kill the process with the specified process ID. Use this in preference
4286 to `k' when multiprocess protocol extensions are supported.
4289 Obtains additional operating system information
4293 Read or write additional signal information.
4295 * Removed remote protocol undocumented extension
4297 An undocumented extension to the remote protocol's `S' stop reply
4298 packet that permitted the stub to pass a process id was removed.
4299 Remote servers should use the `T' stop reply packet instead.
4301 * GDB now supports multiple function calling conventions according to the
4302 DWARF-2 DW_AT_calling_convention function attribute.
4304 * The SH target utilizes the aforementioned change to distinguish between gcc
4305 and Renesas calling convention. It also adds the new CLI commands
4306 `set/show sh calling-convention'.
4308 * GDB can now read compressed debug sections, as produced by GNU gold
4309 with the --compress-debug-sections=zlib flag.
4311 * 64-bit core files are now supported on AIX.
4313 * Thread switching is now supported on Tru64.
4315 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4316 which will be allocated using malloc later in program execution.
4318 * The qXfer:libraries:read remote protocol packet now allows passing a
4319 list of section offsets.
4321 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4322 conditions handling signals delivered during attach or thread creation
4323 have also been fixed.
4325 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4326 From the user's standpoint, all unqualified instances of True and False
4327 are treated as the standard definitions, regardless of context.
4329 * GDB now parses C++ symbol and type names more flexibly. For
4332 template<typename T> class C { };
4335 GDB will now correctly handle all of:
4337 ptype C<char const *>
4338 ptype C<char const*>
4339 ptype C<const char *>
4340 ptype C<const char*>
4342 * New features in the GDB remote stub, gdbserver
4344 - The "--wrapper" command-line argument tells gdbserver to use a
4345 wrapper program to launch programs for debugging.
4347 - On PowerPC and S/390 targets, it is now possible to use a single
4348 gdbserver executable to debug both 32-bit and 64-bit programs.
4349 (This requires gdbserver itself to be built as a 64-bit executable.)
4351 - gdbserver uses the new noack protocol mode for TCP connections to
4352 reduce communications latency, if also supported and enabled in GDB.
4354 - Support for the sparc64-linux-gnu target is now included in
4357 - The amd64-linux build of gdbserver now supports debugging both
4358 32-bit and 64-bit programs.
4360 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4361 now support hardware watchpoints, and will use them automatically
4366 GDB now has support for scripting using Python. Whether this is
4367 available is determined at configure time.
4369 New GDB commands can now be written in Python.
4371 * Ada tasking support
4373 Ada tasks can now be inspected in GDB. The following commands have
4377 Print the list of Ada tasks.
4379 Print detailed information about task number N.
4381 Print the task number of the current task.
4383 Switch the context of debugging to task number N.
4385 * Support for user-defined prefixed commands. The "define" command can
4386 add new commands to existing prefixes, e.g. "target".
4388 * Multi-inferior, multi-process debugging.
4390 GDB now has generalized support for multi-inferior debugging. See
4391 "Debugging Multiple Inferiors" in the manual for more information.
4392 Although availability still depends on target support, the command
4393 set is more uniform now. The GNU/Linux specific multi-forks support
4394 has been migrated to this new framework. This implied some user
4395 visible changes; see "New commands" and also "Removed commands"
4398 * Target descriptions can now describe the target OS ABI. See the
4399 "Target Description Format" section in the user manual for more
4402 * Target descriptions can now describe "compatible" architectures
4403 to indicate that the target can execute applications for a different
4404 architecture in addition to those for the main target architecture.
4405 See the "Target Description Format" section in the user manual for
4408 * Multi-architecture debugging.
4410 GDB now includes general supports for debugging applications on
4411 hybrid systems that use more than one single processor architecture
4412 at the same time. Each such hybrid architecture still requires
4413 specific support to be added. The only hybrid architecture supported
4414 in this version of GDB is the Cell Broadband Engine.
4416 * GDB now supports integrated debugging of Cell/B.E. applications that
4417 use both the PPU and SPU architectures. To enable support for hybrid
4418 Cell/B.E. debugging, you need to configure GDB to support both the
4419 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4420 --enable-targets configure option.
4422 * Non-stop mode debugging.
4424 For some targets, GDB now supports an optional mode of operation in
4425 which you can examine stopped threads while other threads continue
4426 to execute freely. This is referred to as non-stop mode, with the
4427 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4428 section in the user manual for more information.
4430 To be able to support remote non-stop debugging, a remote stub needs
4431 to implement the non-stop mode remote protocol extensions, as
4432 described in the "Remote Non-Stop" section of the user manual. The
4433 GDB remote stub, gdbserver, has been adjusted to support these
4434 extensions on linux targets.
4436 * New commands (for set/show, see "New options" below)
4438 catch syscall [NAME(S) | NUMBER(S)]
4439 Catch system calls. Arguments, which should be names of system
4440 calls or their numbers, mean catch only those syscalls. Without
4441 arguments, every syscall will be caught. When the inferior issues
4442 any of the specified syscalls, GDB will stop and announce the system
4443 call, both when it is called and when its call returns. This
4444 feature is currently available with a native GDB running on the
4445 Linux Kernel, under the following architectures: x86, x86_64,
4446 PowerPC and PowerPC64.
4448 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4450 Search memory for a sequence of bytes.
4452 maint set python print-stack
4453 maint show python print-stack
4454 Show a stack trace when an error is encountered in a Python script.
4457 Invoke CODE by passing it to the Python interpreter.
4462 These allow macros to be defined, undefined, and listed
4466 Show operating system information about processes.
4469 List the inferiors currently under GDB's control.
4472 Switch focus to inferior number NUM.
4475 Detach from inferior number NUM.
4478 Kill inferior number NUM.
4482 set spu stop-on-load
4483 show spu stop-on-load
4484 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4486 set spu auto-flush-cache
4487 show spu auto-flush-cache
4488 Control whether to automatically flush the software-managed cache
4489 during Cell/B.E. debugging.
4491 set sh calling-convention
4492 show sh calling-convention
4493 Control the calling convention used when calling SH target functions.
4496 show debug timestamp
4497 Control display of timestamps with GDB debugging output.
4499 set disassemble-next-line
4500 show disassemble-next-line
4501 Control display of disassembled source lines or instructions when
4504 set remote noack-packet
4505 show remote noack-packet
4506 Set/show the use of remote protocol QStartNoAckMode packet. See above
4507 under "New remote packets."
4509 set remote query-attached-packet
4510 show remote query-attached-packet
4511 Control use of remote protocol `qAttached' (query-attached) packet.
4513 set remote read-siginfo-object
4514 show remote read-siginfo-object
4515 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4518 set remote write-siginfo-object
4519 show remote write-siginfo-object
4520 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4523 set remote reverse-continue
4524 show remote reverse-continue
4525 Control use of remote protocol 'bc' (reverse-continue) packet.
4527 set remote reverse-step
4528 show remote reverse-step
4529 Control use of remote protocol 'bs' (reverse-step) packet.
4531 set displaced-stepping
4532 show displaced-stepping
4533 Control displaced stepping mode. Displaced stepping is a way to
4534 single-step over breakpoints without removing them from the debuggee.
4535 Also known as "out-of-line single-stepping".
4538 show debug displaced
4539 Control display of debugging info for displaced stepping.
4541 maint set internal-error
4542 maint show internal-error
4543 Control what GDB does when an internal error is detected.
4545 maint set internal-warning
4546 maint show internal-warning
4547 Control what GDB does when an internal warning is detected.
4552 Use a wrapper program to launch programs for debugging.
4554 set multiple-symbols (all|ask|cancel)
4555 show multiple-symbols
4556 The value of this variable can be changed to adjust the debugger behavior
4557 when an expression or a breakpoint location contains an ambiguous symbol
4558 name (an overloaded function name, for instance).
4560 set breakpoint always-inserted
4561 show breakpoint always-inserted
4562 Keep breakpoints always inserted in the target, as opposed to inserting
4563 them when resuming the target, and removing them when the target stops.
4564 This option can improve debugger performance on slow remote targets.
4566 set arm fallback-mode (arm|thumb|auto)
4567 show arm fallback-mode
4568 set arm force-mode (arm|thumb|auto)
4570 These commands control how ARM GDB determines whether instructions
4571 are ARM or Thumb. The default for both settings is auto, which uses
4572 the current CPSR value for instructions without symbols; previous
4573 versions of GDB behaved as if "set arm fallback-mode arm".
4575 set disable-randomization
4576 show disable-randomization
4577 Standalone programs run with the virtual address space randomization enabled
4578 by default on some platforms. This option keeps the addresses stable across
4579 multiple debugging sessions.
4583 Control whether other threads are stopped or not when some thread hits
4588 Requests that asynchronous execution is enabled in the target, if available.
4589 In this case, it's possible to resume target in the background, and interact
4590 with GDB while the target is running. "show target-async" displays the
4591 current state of asynchronous execution of the target.
4593 set target-wide-charset
4594 show target-wide-charset
4595 The target-wide-charset is the name of the character set that GDB
4596 uses when printing characters whose type is wchar_t.
4598 set tcp auto-retry (on|off)
4600 set tcp connect-timeout
4601 show tcp connect-timeout
4602 These commands allow GDB to retry failed TCP connections to a remote stub
4603 with a specified timeout period; this is useful if the stub is launched
4604 in parallel with GDB but may not be ready to accept connections immediately.
4606 set libthread-db-search-path
4607 show libthread-db-search-path
4608 Control list of directories which GDB will search for appropriate
4611 set schedule-multiple (on|off)
4612 show schedule-multiple
4613 Allow GDB to resume all threads of all processes or only threads of
4614 the current process.
4618 Use more aggressive caching for accesses to the stack. This improves
4619 performance of remote debugging (particularly backtraces) without
4620 affecting correctness.
4622 set interactive-mode (on|off|auto)
4623 show interactive-mode
4624 Control whether GDB runs in interactive mode (on) or not (off).
4625 When in interactive mode, GDB waits for the user to answer all
4626 queries. Otherwise, GDB does not wait and assumes the default
4627 answer. When set to auto (the default), GDB determines which
4628 mode to use based on the stdin settings.
4633 For program forks, this is replaced by the new more generic `info
4634 inferiors' command. To list checkpoints, you can still use the
4635 `info checkpoints' command, which was an alias for the `info forks'
4639 Replaced by the new `inferior' command. To switch between
4640 checkpoints, you can still use the `restart' command, which was an
4641 alias for the `fork' command.
4644 This is removed, since some targets don't have a notion of
4645 processes. To switch between processes, you can still use the
4646 `inferior' command using GDB's own inferior number.
4649 For program forks, this is replaced by the new more generic `kill
4650 inferior' command. To delete a checkpoint, you can still use the
4651 `delete checkpoint' command, which was an alias for the `delete
4655 For program forks, this is replaced by the new more generic `detach
4656 inferior' command. To detach a checkpoint, you can still use the
4657 `detach checkpoint' command, which was an alias for the `detach
4660 * New native configurations
4662 x86/x86_64 Darwin i[34567]86-*-darwin*
4664 x86_64 MinGW x86_64-*-mingw*
4668 Lattice Mico32 lm32-*
4669 x86 DICOS i[34567]86-*-dicos*
4670 x86_64 DICOS x86_64-*-dicos*
4673 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4674 (mingw32ce) debugging.
4680 These commands were actually not implemented on any target.
4682 *** Changes in GDB 6.8
4684 * New native configurations
4686 NetBSD/hppa hppa*-*netbsd*
4687 Xtensa GNU/Linux xtensa*-*-linux*
4691 NetBSD/hppa hppa*-*-netbsd*
4692 Xtensa GNU/Linux xtensa*-*-linux*
4694 * Change in command line behavior -- corefiles vs. process ids.
4696 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4697 attaching to process NUMBER fails, GDB no longer attempts to open a
4698 core file named NUMBER. Attaching to a program using the -c option
4699 is no longer supported. Instead, use the '-p' or '--pid' options.
4701 * GDB can now be built as a native debugger for debugging Windows x86
4702 (mingw32) Portable Executable (PE) programs.
4704 * Pending breakpoints no longer change their number when their address
4707 * GDB now supports breakpoints with multiple locations,
4708 including breakpoints on C++ constructors, inside C++ templates,
4709 and in inlined functions.
4711 * GDB's ability to debug optimized code has been improved. GDB more
4712 accurately identifies function bodies and lexical blocks that occupy
4713 more than one contiguous range of addresses.
4715 * Target descriptions can now describe registers for PowerPC.
4717 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4718 registers on PowerPC targets.
4720 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4721 targets even when the libthread_db library is not available.
4723 * The GDB remote stub, gdbserver, now supports the new file transfer
4724 commands (remote put, remote get, and remote delete).
4726 * The GDB remote stub, gdbserver, now supports run and attach in
4727 extended-remote mode.
4729 * hppa*64*-*-hpux11* target broken
4730 The debugger is unable to start a program and fails with the following
4731 error: "Error trying to get information about dynamic linker".
4732 The gdb-6.7 release is also affected.
4734 * GDB now supports the --enable-targets= configure option to allow
4735 building a single GDB executable that supports multiple remote
4736 target architectures.
4738 * GDB now supports debugging C and C++ programs which use the
4739 Decimal Floating Point extension. In addition, the PowerPC target
4740 now has a set of pseudo-registers to inspect decimal float values
4741 stored in two consecutive float registers.
4743 * The -break-insert MI command can optionally create pending
4746 * Improved support for debugging Ada
4747 Many improvements to the Ada language support have been made. These
4749 - Better support for Ada2005 interface types
4750 - Improved handling of arrays and slices in general
4751 - Better support for Taft-amendment types
4752 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4754 - Improved command completion in Ada
4757 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4762 set print frame-arguments (all|scalars|none)
4763 show print frame-arguments
4764 The value of this variable can be changed to control which argument
4765 values should be printed by the debugger when displaying a frame.
4770 Transfer files to and from a remote target, and delete remote files.
4777 Transfer files to and from a remote target, and delete remote files.
4779 * New remote packets
4786 Open, close, read, write, and delete files on the remote system.
4789 Attach to an existing process on the remote system, in extended-remote
4793 Run a new process on the remote system, in extended-remote mode.
4795 *** Changes in GDB 6.7
4797 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4798 bfd, libiberty and opcodes, as revealed by static analysis donated by
4799 Coverity, Inc. (http://scan.coverity.com).
4801 * When looking up multiply-defined global symbols, GDB will now prefer the
4802 symbol definition in the current shared library if it was built using the
4803 -Bsymbolic linker option.
4805 * When the Text User Interface (TUI) is not configured, GDB will now
4806 recognize the -tui command-line option and print a message that the TUI
4809 * The GDB remote stub, gdbserver, now has lower overhead for high
4810 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4812 * GDB for MIPS targets now autodetects whether a remote target provides
4813 32-bit or 64-bit register values.
4815 * Support for C++ member pointers has been improved.
4817 * GDB now understands XML target descriptions, which specify the
4818 target's overall architecture. GDB can read a description from
4819 a local file or over the remote serial protocol.
4821 * Vectors of single-byte data use a new integer type which is not
4822 automatically displayed as character or string data.
4824 * The /s format now works with the print command. It displays
4825 arrays of single-byte integers and pointers to single-byte integers
4828 * Target descriptions can now describe target-specific registers,
4829 for architectures which have implemented the support (currently
4830 only ARM, M68K, and MIPS).
4832 * GDB and the GDB remote stub, gdbserver, now support the XScale
4835 * The GDB remote stub, gdbserver, has been updated to support
4836 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4837 has been rewritten to use the standard GDB remote protocol.
4839 * GDB can now step into C++ functions which are called through thunks.
4841 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4843 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4844 layout. It also supports a TextSeg= and DataSeg= response when only
4845 segment base addresses (rather than offsets) are available.
4847 * The /i format now outputs any trailing branch delay slot instructions
4848 immediately following the last instruction within the count specified.
4850 * The GDB remote protocol "T" stop reply packet now supports a
4851 "library" response. Combined with the new "qXfer:libraries:read"
4852 packet, this response allows GDB to debug shared libraries on targets
4853 where the operating system manages the list of loaded libraries (e.g.
4854 Windows and SymbianOS).
4856 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4857 (DLLs) on Windows and Windows CE targets.
4859 * GDB now supports a faster verification that a .debug file matches its binary
4860 according to its build-id signature, if the signature is present.
4866 Enable or disable hardware flow control (RTS/CTS) on the serial port
4867 when debugging using remote targets.
4869 set mem inaccessible-by-default
4870 show mem inaccessible-by-default
4871 If the target supplies a memory map, for instance via the remote
4872 protocol's "qXfer:memory-map:read" packet, setting this variable
4873 prevents GDB from accessing memory outside the memory map. This
4874 is useful for targets with memory mapped registers or which react
4875 badly to accesses of unmapped address space.
4877 set breakpoint auto-hw
4878 show breakpoint auto-hw
4879 If the target supplies a memory map, for instance via the remote
4880 protocol's "qXfer:memory-map:read" packet, setting this variable
4881 lets GDB use hardware breakpoints automatically for memory regions
4882 where it can not use software breakpoints. This covers both the
4883 "break" command and internal breakpoints used for other commands
4884 including "next" and "finish".
4887 catch exception unhandled
4888 Stop the program execution when Ada exceptions are raised.
4891 Stop the program execution when an Ada assertion failed.
4895 Set an alternate system root for target files. This is a more
4896 general version of "set solib-absolute-prefix", which is now
4897 an alias to "set sysroot".
4900 Provide extended SPU facility status information. This set of
4901 commands is available only when debugging the Cell/B.E. SPU
4904 * New native configurations
4906 OpenBSD/sh sh*-*openbsd*
4909 unset tdesc filename
4911 Use the specified local file as an XML target description, and do
4912 not query the target for its built-in description.
4916 OpenBSD/sh sh*-*-openbsd*
4917 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4918 Toshiba Media Processor mep-elf
4920 * New remote packets
4923 Ignore the specified signals; pass them directly to the debugged program
4924 without stopping other threads or reporting them to GDB.
4926 qXfer:features:read:
4927 Read an XML target description from the target, which describes its
4932 Read or write contents of an spufs file on the target system. These
4933 packets are available only on the Cell/B.E. SPU architecture.
4935 qXfer:libraries:read:
4936 Report the loaded shared libraries. Combined with new "T" packet
4937 response, this packet allows GDB to debug shared libraries on
4938 targets where the operating system manages the list of loaded
4939 libraries (e.g. Windows and SymbianOS).
4943 Support for these obsolete configurations has been removed.
4951 i[34567]86-*-lynxos*
4952 i[34567]86-*-netware*
4953 i[34567]86-*-sco3.2v5*
4954 i[34567]86-*-sco3.2v4*
4956 i[34567]86-*-sysv4.2*
4959 i[34567]86-*-unixware2*
4960 i[34567]86-*-unixware*
4969 * Other removed features
4976 Various m68k-only ROM monitors.
4983 Various Renesas ROM monitors and debugging interfaces for SH and
4988 Support for a Macraigor serial interface to on-chip debugging.
4989 GDB does not directly support the newer parallel or USB
4994 A debug information format. The predecessor to DWARF 2 and
4995 DWARF 3, which are still supported.
4997 Support for the HP aCC compiler on HP-UX/PA-RISC
4999 SOM-encapsulated symbolic debugging information, automatic
5000 invocation of pxdb, and the aCC custom C++ ABI. This does not
5001 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5002 with aCC can still be debugged on an assembly level.
5004 MIPS ".pdr" sections
5006 A MIPS-specific format used to describe stack frame layout
5007 in debugging information.
5011 GDB could work with an older version of Guile to debug
5012 the interpreter and Scheme programs running in it.
5014 set mips stack-arg-size
5015 set mips saved-gpreg-size
5017 Use "set mips abi" to control parameter passing for MIPS.
5019 *** Changes in GDB 6.6
5024 Cell Broadband Engine SPU spu-elf
5026 * GDB can now be configured as a cross-debugger targeting native Windows
5027 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5028 running on a Windows system over TCP/IP to debug Windows programs.
5030 * The GDB remote stub, gdbserver, has been updated to support Windows and
5031 Cygwin debugging. Both single-threaded and multi-threaded programs are
5034 * The "set trust-readonly-sections" command works again. This command was
5035 broken in GDB 6.3, 6.4, and 6.5.
5037 * The "load" command now supports writing to flash memory, if the remote
5038 stub provides the required support.
5040 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5041 longer requires symbolic debug information (e.g. DWARF-2).
5046 unset substitute-path
5047 show substitute-path
5048 Manage a list of substitution rules that GDB uses to rewrite the name
5049 of the directories where the sources are located. This can be useful
5050 for instance when the sources were moved to a different location
5051 between compilation and debugging.
5055 Print each CLI command as it is executed. Each command is prefixed with
5056 a number of `+' symbols representing the nesting depth.
5057 The source command now has a `-v' option to enable the same feature.
5061 The ARM Demon monitor support (RDP protocol, "target rdp").
5063 Kernel Object Display, an embedded debugging feature which only worked with
5064 an obsolete version of Cisco IOS.
5066 The 'set download-write-size' and 'show download-write-size' commands.
5068 * New remote packets
5071 Tell a stub about GDB client features, and request remote target features.
5072 The first feature implemented is PacketSize, which allows the target to
5073 specify the size of packets it can handle - to minimize the number of
5074 packets required and improve performance when connected to a remote
5078 Fetch an OS auxilliary vector from the remote stub. This packet is a
5079 more efficient replacement for qPart:auxv:read.
5081 qXfer:memory-map:read:
5082 Fetch a memory map from the remote stub, including information about
5083 RAM, ROM, and flash memory devices.
5088 Erase and program a flash memory device.
5090 * Removed remote packets
5093 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5094 used it, and only gdbserver implemented it.
5096 *** Changes in GDB 6.5
5100 Renesas M32C/M16C m32c-elf
5102 Morpho Technologies ms1 ms1-elf
5106 init-if-undefined Initialize a convenience variable, but
5107 only if it doesn't already have a value.
5109 The following commands are presently only implemented for native GNU/Linux:
5111 checkpoint Save a snapshot of the program state.
5113 restart <n> Return the program state to a
5114 previously saved state.
5116 info checkpoints List currently saved checkpoints.
5118 delete-checkpoint <n> Delete a previously saved checkpoint.
5120 set|show detach-on-fork Tell gdb whether to detach from a newly
5121 forked process, or to keep debugging it.
5123 info forks List forks of the user program that
5124 are available to be debugged.
5126 fork <n> Switch to debugging one of several
5127 forks of the user program that are
5128 available to be debugged.
5130 delete-fork <n> Delete a fork from the list of forks
5131 that are available to be debugged (and
5132 kill the forked process).
5134 detach-fork <n> Delete a fork from the list of forks
5135 that are available to be debugged (and
5136 allow the process to continue).
5140 Morpho Technologies ms2 ms1-elf
5142 * Improved Windows host support
5144 GDB now builds as a cross debugger hosted on i686-mingw32, including
5145 native console support, and remote communications using either
5146 network sockets or serial ports.
5148 * Improved Modula-2 language support
5150 GDB can now print most types in the Modula-2 syntax. This includes:
5151 basic types, set types, record types, enumerated types, range types,
5152 pointer types and ARRAY types. Procedure var parameters are correctly
5153 printed and hexadecimal addresses and character constants are also
5154 written in the Modula-2 syntax. Best results can be obtained by using
5155 GNU Modula-2 together with the -gdwarf-2 command line option.
5159 The ARM rdi-share module.
5161 The Netware NLM debug server.
5163 *** Changes in GDB 6.4
5165 * New native configurations
5167 OpenBSD/arm arm*-*-openbsd*
5168 OpenBSD/mips64 mips64-*-openbsd*
5172 Morpho Technologies ms1 ms1-elf
5174 * New command line options
5176 --batch-silent As for --batch, but totally silent.
5177 --return-child-result The debugger will exist with the same value
5178 the child (debugged) program exited with.
5179 --eval-command COMMAND, -ex COMMAND
5180 Execute a single GDB CLI command. This may be
5181 specified multiple times and in conjunction
5182 with the --command (-x) option.
5184 * Deprecated commands removed
5186 The following commands, that were deprecated in 2000, have been
5190 set|show arm disassembly-flavor set|show arm disassembler
5191 othernames set arm disassembler
5192 set|show remotedebug set|show debug remote
5193 set|show archdebug set|show debug arch
5194 set|show eventdebug set|show debug event
5197 * New BSD user-level threads support
5199 It is now possible to debug programs using the user-level threads
5200 library on OpenBSD and FreeBSD. Currently supported (target)
5203 FreeBSD/amd64 x86_64-*-freebsd*
5204 FreeBSD/i386 i386-*-freebsd*
5205 OpenBSD/i386 i386-*-openbsd*
5207 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5208 are not yet supported.
5210 * New support for Matsushita MN10300 w/sim added
5211 (Work in progress). mn10300-elf.
5213 * REMOVED configurations and files
5215 VxWorks and the XDR protocol *-*-vxworks
5216 Motorola MCORE mcore-*-*
5217 National Semiconductor NS32000 ns32k-*-*
5219 * New "set print array-indexes" command
5221 After turning this setting "on", GDB prints the index of each element
5222 when displaying arrays. The default is "off" to preserve the previous
5225 * VAX floating point support
5227 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5229 * User-defined command support
5231 In addition to using $arg0..$arg9 for argument passing, it is now possible
5232 to use $argc to determine now many arguments have been passed. See the
5233 section on user-defined commands in the user manual for more information.
5235 *** Changes in GDB 6.3:
5237 * New command line option
5239 GDB now accepts -l followed by a number to set the timeout for remote
5242 * GDB works with GCC -feliminate-dwarf2-dups
5244 GDB now supports a more compact representation of DWARF-2 debug
5245 information using DW_FORM_ref_addr references. These are produced
5246 by GCC with the option -feliminate-dwarf2-dups and also by some
5247 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5248 to use -feliminate-dwarf2-dups.
5250 * Internationalization
5252 When supported by the host system, GDB will be built with
5253 internationalization (libintl). The task of marking up the sources is
5254 continued, we're looking forward to our first translation.
5258 Initial support for debugging programs compiled with the GNAT
5259 implementation of the Ada programming language has been integrated
5260 into GDB. In this release, support is limited to expression evaluation.
5262 * New native configurations
5264 GNU/Linux/m32r m32r-*-linux-gnu
5268 GDB's remote protocol now includes support for the 'p' packet. This
5269 packet is used to fetch individual registers from a remote inferior.
5271 * END-OF-LIFE registers[] compatibility module
5273 GDB's internal register infrastructure has been completely rewritten.
5274 The new infrastructure making possible the implementation of key new
5275 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5278 GDB 6.3 will be the last release to include the registers[]
5279 compatibility module that allowed out-of-date configurations to
5280 continue to work. This change directly impacts the following
5290 powerpc bdm protocol
5292 Unless there is activity to revive these configurations, they will be
5293 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5295 * OBSOLETE configurations and files
5297 Configurations that have been declared obsolete in this release have
5298 been commented out. Unless there is activity to revive these
5299 configurations, the next release of GDB will have their sources
5300 permanently REMOVED.
5309 *** Changes in GDB 6.2.1:
5311 * MIPS `break main; run' gave an heuristic-fence-post warning
5313 When attempting to run even a simple program, a warning about
5314 heuristic-fence-post being hit would be reported. This problem has
5317 * MIPS IRIX 'long double' crashed GDB
5319 When examining a long double variable, GDB would get a segmentation
5320 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5321 IRIX long double values).
5325 A bug in the VAX stack code was causing problems with the "next"
5326 command. This problem has been fixed.
5328 *** Changes in GDB 6.2:
5330 * Fix for ``many threads''
5332 On GNU/Linux systems that use the NPTL threads library, a program
5333 rapidly creating and deleting threads would confuse GDB leading to the
5336 ptrace: No such process.
5337 thread_db_get_info: cannot get thread info: generic error
5339 This problem has been fixed.
5341 * "-async" and "-noasync" options removed.
5343 Support for the broken "-noasync" option has been removed (it caused
5346 * New ``start'' command.
5348 This command runs the program until the beginning of the main procedure.
5350 * New BSD Kernel Data Access Library (libkvm) interface
5352 Using ``target kvm'' it is now possible to debug kernel core dumps and
5353 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5354 platforms. Currently supported (native-only) configurations are:
5356 FreeBSD/amd64 x86_64-*-freebsd*
5357 FreeBSD/i386 i?86-*-freebsd*
5358 NetBSD/i386 i?86-*-netbsd*
5359 NetBSD/m68k m68*-*-netbsd*
5360 NetBSD/sparc sparc-*-netbsd*
5361 OpenBSD/amd64 x86_64-*-openbsd*
5362 OpenBSD/i386 i?86-*-openbsd*
5363 OpenBSD/m68k m68*-openbsd*
5364 OpenBSD/sparc sparc-*-openbsd*
5366 * Signal trampoline code overhauled
5368 Many generic problems with GDB's signal handling code have been fixed.
5369 These include: backtraces through non-contiguous stacks; recognition
5370 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5371 call; backtrace through a signal trampoline; step into and out of
5372 signal handlers; and single-stepping in the signal trampoline.
5374 Please note that kernel bugs are a limiting factor here. These
5375 features have been shown to work on an s390 GNU/Linux system that
5376 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5378 * Cygwin support for DWARF 2 added.
5380 * New native configurations
5382 GNU/Linux/hppa hppa*-*-linux*
5383 OpenBSD/hppa hppa*-*-openbsd*
5384 OpenBSD/m68k m68*-*-openbsd*
5385 OpenBSD/m88k m88*-*-openbsd*
5386 OpenBSD/powerpc powerpc-*-openbsd*
5387 NetBSD/vax vax-*-netbsd*
5388 OpenBSD/vax vax-*-openbsd*
5390 * END-OF-LIFE frame compatibility module
5392 GDB's internal frame infrastructure has been completely rewritten.
5393 The new infrastructure making it possible to support key new features
5394 including DWARF 2 Call Frame Information. To aid in the task of
5395 migrating old configurations to this new infrastructure, a
5396 compatibility module, that allowed old configurations to continue to
5397 work, was also included.
5399 GDB 6.2 will be the last release to include this frame compatibility
5400 module. This change directly impacts the following configurations:
5410 Unless there is activity to revive these configurations, they will be
5411 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5413 * REMOVED configurations and files
5415 Sun 3, running SunOS 3 m68*-*-sunos3*
5416 Sun 3, running SunOS 4 m68*-*-sunos4*
5417 Sun 2, running SunOS 3 m68000-*-sunos3*
5418 Sun 2, running SunOS 4 m68000-*-sunos4*
5419 Motorola 680x0 running LynxOS m68*-*-lynxos*
5420 AT&T 3b1/Unix pc m68*-att-*
5421 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5422 decstation mips-dec-* mips-little-*
5423 riscos mips-*-riscos* mips-*-sysv*
5424 sonymips mips-sony-*
5425 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5427 *** Changes in GDB 6.1.1:
5429 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5431 The TUI (Text-mode User Interface) is now built as part of a default
5432 GDB configuration. It is enabled by either selecting the TUI with the
5433 command line option "-i=tui" or by running the separate "gdbtui"
5434 program. For more information on the TUI, see the manual "Debugging
5437 * Pending breakpoint support (also included in GDB 6.1)
5439 Support has been added to allow you to specify breakpoints in shared
5440 libraries that have not yet been loaded. If a breakpoint location
5441 cannot be found, and the "breakpoint pending" option is set to auto,
5442 GDB queries you if you wish to make the breakpoint pending on a future
5443 shared-library load. If and when GDB resolves the breakpoint symbol,
5444 the pending breakpoint is removed as one or more regular breakpoints
5447 Pending breakpoints are very useful for GCJ Java debugging.
5449 * Fixed ISO-C build problems
5451 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5452 non ISO-C code that stopped them being built using a more strict ISO-C
5453 compiler (e.g., IBM's C compiler).
5455 * Fixed build problem on IRIX 5
5457 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5458 wasn't able to compile compile on an IRIX 5 system.
5460 * Added execute permission to gdb/gdbserver/configure
5462 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5463 permission. This bug would cause configure to fail on a number of
5464 systems (Solaris, IRIX). Ref: server/519.
5466 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5468 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5469 has been updated to use constant array sizes.
5471 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5473 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5474 its generated DWARF Call Frame Info. This encoding was causing GDB to
5475 panic, that panic has been fixed. Ref: gdb/1628.
5477 * Fixed a problem when examining parameters in shared library code.
5479 When examining parameters in optimized shared library code generated
5480 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5481 not available''. GDB now correctly displays the variable's value.
5483 *** Changes in GDB 6.1:
5485 * Removed --with-mmalloc
5487 Support for the mmalloc memory manager has been removed, as it
5488 conflicted with the internal gdb byte cache.
5490 * Changes in AMD64 configurations
5492 The AMD64 target now includes the %cs and %ss registers. As a result
5493 the AMD64 remote protocol has changed; this affects the floating-point
5494 and SSE registers. If you rely on those registers for your debugging,
5495 you should upgrade gdbserver on the remote side.
5497 * Revised SPARC target
5499 The SPARC target has been completely revised, incorporating the
5500 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5501 support for LynxOS and SunOS 4 has been dropped. Calling functions
5502 from within GDB on operating systems with a non-executable stack
5503 (Solaris, OpenBSD) now works.
5507 GDB has a new C++ demangler which does a better job on the mangled
5508 names generated by current versions of g++. It also runs faster, so
5509 with this and other changes gdb should now start faster on large C++
5512 * DWARF 2 Location Expressions
5514 GDB support for location expressions has been extended to support function
5515 arguments and frame bases. Older versions of GDB could crash when they
5518 * C++ nested types and namespaces
5520 GDB's support for nested types and namespaces in C++ has been
5521 improved, especially if you use the DWARF 2 debugging format. (This
5522 is the default for recent versions of GCC on most platforms.)
5523 Specifically, if you have a class "Inner" defined within a class or
5524 namespace "Outer", then GDB realizes that the class's name is
5525 "Outer::Inner", not simply "Inner". This should greatly reduce the
5526 frequency of complaints about not finding RTTI symbols. In addition,
5527 if you are stopped at inside of a function defined within a namespace,
5528 GDB modifies its name lookup accordingly.
5530 * New native configurations
5532 NetBSD/amd64 x86_64-*-netbsd*
5533 OpenBSD/amd64 x86_64-*-openbsd*
5534 OpenBSD/alpha alpha*-*-openbsd*
5535 OpenBSD/sparc sparc-*-openbsd*
5536 OpenBSD/sparc64 sparc64-*-openbsd*
5538 * New debugging protocols
5540 M32R with SDI protocol m32r-*-elf*
5542 * "set prompt-escape-char" command deleted.
5544 The command "set prompt-escape-char" has been deleted. This command,
5545 and its very obscure effect on GDB's prompt, was never documented,
5546 tested, nor mentioned in the NEWS file.
5548 * OBSOLETE configurations and files
5550 Configurations that have been declared obsolete in this release have
5551 been commented out. Unless there is activity to revive these
5552 configurations, the next release of GDB will have their sources
5553 permanently REMOVED.
5555 Sun 3, running SunOS 3 m68*-*-sunos3*
5556 Sun 3, running SunOS 4 m68*-*-sunos4*
5557 Sun 2, running SunOS 3 m68000-*-sunos3*
5558 Sun 2, running SunOS 4 m68000-*-sunos4*
5559 Motorola 680x0 running LynxOS m68*-*-lynxos*
5560 AT&T 3b1/Unix pc m68*-att-*
5561 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5562 decstation mips-dec-* mips-little-*
5563 riscos mips-*-riscos* mips-*-sysv*
5564 sonymips mips-sony-*
5565 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5567 * REMOVED configurations and files
5569 SGI Irix-4.x mips-sgi-irix4 or iris4
5570 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5571 Z8000 simulator z8k-zilog-none or z8ksim
5572 Matsushita MN10200 w/simulator mn10200-*-*
5573 H8/500 simulator h8500-hitachi-hms or h8500hms
5574 HP/PA running BSD hppa*-*-bsd*
5575 HP/PA running OSF/1 hppa*-*-osf*
5576 HP/PA Pro target hppa*-*-pro*
5577 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5578 386BSD i[3456]86-*-bsd*
5579 Sequent family i[3456]86-sequent-sysv4*
5580 i[3456]86-sequent-sysv*
5581 i[3456]86-sequent-bsd*
5582 SPARC running LynxOS sparc-*-lynxos*
5583 SPARC running SunOS 4 sparc-*-sunos4*
5584 Tsqware Sparclet sparclet-*-*
5585 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5587 *** Changes in GDB 6.0:
5591 Support for debugging the Objective-C programming language has been
5592 integrated into GDB.
5594 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5596 DWARF 2's Call Frame Information makes available compiler generated
5597 information that more exactly describes the program's run-time stack.
5598 By using this information, GDB is able to provide more robust stack
5601 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5602 have been updated to use a new backtrace mechanism which includes
5603 DWARF 2 CFI support.
5607 GDB's remote protocol has been extended to include support for hosted
5608 file I/O (where the remote target uses GDB's file system). See GDB's
5609 remote protocol documentation for details.
5611 * All targets using the new architecture framework.
5613 All of GDB's targets have been updated to use the new internal
5614 architecture framework. The way is now open for future GDB releases
5615 to include cross-architecture native debugging support (i386 on amd64,
5618 * GNU/Linux's Thread Local Storage (TLS)
5620 GDB now includes support for for the GNU/Linux implementation of
5621 per-thread variables.
5623 * GNU/Linux's Native POSIX Thread Library (NPTL)
5625 GDB's thread code has been updated to work with either the new
5626 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5628 * Separate debug info.
5630 GDB, in conjunction with BINUTILS, now supports a mechanism for
5631 automatically loading debug information from a separate file. Instead
5632 of shipping full debug and non-debug versions of system libraries,
5633 system integrators can now instead ship just the stripped libraries
5634 and optional debug files.
5636 * DWARF 2 Location Expressions
5638 DWARF 2 Location Expressions allow the compiler to more completely
5639 describe the location of variables (even in optimized code) to the
5642 GDB now includes preliminary support for location expressions (support
5643 for DW_OP_piece is still missing).
5647 A number of long standing bugs that caused GDB to die while starting a
5648 Java application have been fixed. GDB's Java support is now
5649 considered "useable".
5651 * GNU/Linux support for fork, vfork, and exec.
5653 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5654 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5657 * GDB supports logging output to a file
5659 There are two new commands, "set logging" and "show logging", which can be
5660 used to capture GDB's output to a file.
5662 * The meaning of "detach" has changed for gdbserver
5664 The "detach" command will now resume the application, as documented. To
5665 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5668 * d10v, m68hc11 `regs' command deprecated
5670 The `info registers' command has been updated so that it displays the
5671 registers using a format identical to the old `regs' command.
5675 A new command, "maint set profile on/off", has been added. This command can
5676 be used to enable or disable profiling while running GDB, to profile a
5677 session or a set of commands. In addition there is a new configure switch,
5678 "--enable-profiling", which will cause GDB to be compiled with profiling
5679 data, for more informative profiling results.
5681 * Default MI syntax changed to "mi2".
5683 The default MI (machine interface) syntax, enabled by the command line
5684 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5685 "mi1", can be enabled by specifying the option "-i=mi1".
5687 Support for the original "mi0" syntax (included in GDB 5.0) has been
5690 Fix for gdb/192: removed extraneous space when displaying frame level.
5691 Fix for gdb/672: update changelist is now output in mi list format.
5692 Fix for gdb/702: a -var-assign that updates the value now shows up
5693 in a subsequent -var-update.
5695 * New native configurations.
5697 FreeBSD/amd64 x86_64-*-freebsd*
5699 * Multi-arched targets.
5701 HP/PA HPUX11 hppa*-*-hpux*
5702 Renesas M32R/D w/simulator m32r-*-elf*
5704 * OBSOLETE configurations and files
5706 Configurations that have been declared obsolete in this release have
5707 been commented out. Unless there is activity to revive these
5708 configurations, the next release of GDB will have their sources
5709 permanently REMOVED.
5711 Z8000 simulator z8k-zilog-none or z8ksim
5712 Matsushita MN10200 w/simulator mn10200-*-*
5713 H8/500 simulator h8500-hitachi-hms or h8500hms
5714 HP/PA running BSD hppa*-*-bsd*
5715 HP/PA running OSF/1 hppa*-*-osf*
5716 HP/PA Pro target hppa*-*-pro*
5717 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5718 Sequent family i[3456]86-sequent-sysv4*
5719 i[3456]86-sequent-sysv*
5720 i[3456]86-sequent-bsd*
5721 Tsqware Sparclet sparclet-*-*
5722 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5724 * REMOVED configurations and files
5727 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5728 IBM AIX PS/2 i[3456]86-*-aix
5729 i386 running Mach 3.0 i[3456]86-*-mach3*
5730 i386 running Mach i[3456]86-*-mach*
5731 i386 running OSF/1 i[3456]86-*osf1mk*
5732 HP/Apollo 68k Family m68*-apollo*-sysv*,
5734 m68*-hp-bsd*, m68*-hp-hpux*
5735 Argonaut Risc Chip (ARC) arc-*-*
5736 Mitsubishi D30V d30v-*-*
5737 Fujitsu FR30 fr30-*-elf*
5738 OS/9000 i[34]86-*-os9k
5739 I960 with MON960 i960-*-coff
5741 * MIPS $fp behavior changed
5743 The convenience variable $fp, for the MIPS, now consistently returns
5744 the address of the current frame's base. Previously, depending on the
5745 context, $fp could refer to either $sp or the current frame's base
5746 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5747 The GNU Source-Level Debugger''.
5749 *** Changes in GDB 5.3:
5751 * GNU/Linux shared library multi-threaded performance improved.
5753 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5754 `/proc', in preference to `ptrace' for memory reads. This may result
5755 in an improvement in the start-up time of multi-threaded, shared
5756 library applications when run under GDB. One GDB user writes: ``loads
5757 shared libs like mad''.
5759 * ``gdbserver'' now supports multi-threaded applications on some targets
5761 Support for debugging multi-threaded applications which use
5762 the GNU/Linux LinuxThreads package has been added for
5763 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5764 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5766 * GDB now supports C/C++ preprocessor macros.
5768 GDB now expands preprocessor macro invocations in C/C++ expressions,
5769 and provides various commands for showing macro definitions and how
5772 The new command `macro expand EXPRESSION' expands any macro
5773 invocations in expression, and shows the result.
5775 The new command `show macro MACRO-NAME' shows the definition of the
5776 macro named MACRO-NAME, and where it was defined.
5778 Most compilers don't include information about macros in the debugging
5779 information by default. In GCC 3.1, for example, you need to compile
5780 your program with the options `-gdwarf-2 -g3'. If the macro
5781 information is present in the executable, GDB will read it.
5783 * Multi-arched targets.
5785 DEC Alpha (partial) alpha*-*-*
5786 DEC VAX (partial) vax-*-*
5788 National Semiconductor NS32000 (partial) ns32k-*-*
5789 Motorola 68000 (partial) m68k-*-*
5790 Motorola MCORE mcore-*-*
5794 Fujitsu FRV architecture added by Red Hat frv*-*-*
5797 * New native configurations
5799 Alpha NetBSD alpha*-*-netbsd*
5800 SH NetBSD sh*-*-netbsdelf*
5801 MIPS NetBSD mips*-*-netbsd*
5802 UltraSPARC NetBSD sparc64-*-netbsd*
5804 * OBSOLETE configurations and files
5806 Configurations that have been declared obsolete in this release have
5807 been commented out. Unless there is activity to revive these
5808 configurations, the next release of GDB will have their sources
5809 permanently REMOVED.
5811 Mitsubishi D30V d30v-*-*
5812 OS/9000 i[34]86-*-os9k
5813 IBM AIX PS/2 i[3456]86-*-aix
5814 Fujitsu FR30 fr30-*-elf*
5815 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5816 Argonaut Risc Chip (ARC) arc-*-*
5817 i386 running Mach 3.0 i[3456]86-*-mach3*
5818 i386 running Mach i[3456]86-*-mach*
5819 i386 running OSF/1 i[3456]86-*osf1mk*
5820 HP/Apollo 68k Family m68*-apollo*-sysv*,
5822 m68*-hp-bsd*, m68*-hp-hpux*
5823 I960 with MON960 i960-*-coff
5825 * OBSOLETE languages
5827 CHILL, a Pascal like language used by telecommunications companies.
5829 * REMOVED configurations and files
5831 AMD 29k family via UDI a29k-amd-udi, udi29k
5832 A29K VxWorks a29k-*-vxworks
5833 AMD 29000 embedded, using EBMON a29k-none-none
5834 AMD 29000 embedded with COFF a29k-none-coff
5835 AMD 29000 embedded with a.out a29k-none-aout
5837 testsuite/gdb.hp/gdb.threads-hp/ directory
5839 * New command "set max-user-call-depth <nnn>"
5841 This command allows the user to limit the call depth of user-defined
5842 commands. The default is 1024.
5844 * Changes in FreeBSD/i386 native debugging.
5846 Support for the "generate-core-file" has been added.
5848 * New commands "dump", "append", and "restore".
5850 These commands allow data to be copied from target memory
5851 to a bfd-format or binary file (dump and append), and back
5852 from a file into memory (restore).
5854 * Improved "next/step" support on multi-processor Alpha Tru64.
5856 The previous single-step mechanism could cause unpredictable problems,
5857 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5858 of a software single-step mechanism prevents this.
5860 *** Changes in GDB 5.2.1:
5868 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5869 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5870 Fix, by Joel Brobecker imported from mainline.
5872 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5873 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5874 Fix, by Fred Fish, imported from mainline.
5876 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5877 Surprisingly enough, it works now.
5878 By Michal Ludvig, imported from mainline.
5880 i386 hardware watchpoint support:
5881 avoid misses on second run for some targets.
5882 By Pierre Muller, imported from mainline.
5884 *** Changes in GDB 5.2:
5886 * New command "set trust-readonly-sections on[off]".
5888 This command is a hint that tells gdb that read-only sections
5889 really are read-only (ie. that their contents will not change).
5890 In this mode, gdb will go to the object file rather than the
5891 target to read memory from read-only sections (such as ".text").
5892 This can be a significant performance improvement on some
5893 (notably embedded) targets.
5895 * New command "generate-core-file" (or "gcore").
5897 This new gdb command allows the user to drop a core file of the child
5898 process state at any time. So far it's been implemented only for
5899 GNU/Linux and Solaris, but should be relatively easily ported to other
5900 hosts. Argument is core file name (defaults to core.<pid>).
5902 * New command line option
5904 GDB now accepts --pid or -p followed by a process id.
5906 * Change in command line behavior -- corefiles vs. process ids.
5908 There is a subtle behavior in the way in which GDB handles
5909 command line arguments. The first non-flag argument is always
5910 a program to debug, but the second non-flag argument may either
5911 be a corefile or a process id. Previously, GDB would attempt to
5912 open the second argument as a corefile, and if that failed, would
5913 issue a superfluous error message and then attempt to attach it as
5914 a process. Now, if the second argument begins with a non-digit,
5915 it will be treated as a corefile. If it begins with a digit,
5916 GDB will attempt to attach it as a process, and if no such process
5917 is found, will then attempt to open it as a corefile.
5919 * Changes in ARM configurations.
5921 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5922 configuration is fully multi-arch.
5924 * New native configurations
5926 ARM NetBSD arm*-*-netbsd*
5927 x86 OpenBSD i[3456]86-*-openbsd*
5928 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5929 Sparc64 running FreeBSD sparc64-*-freebsd*
5933 Sanyo XStormy16 xstormy16-elf
5935 * OBSOLETE configurations and files
5937 Configurations that have been declared obsolete in this release have
5938 been commented out. Unless there is activity to revive these
5939 configurations, the next release of GDB will have their sources
5940 permanently REMOVED.
5942 AMD 29k family via UDI a29k-amd-udi, udi29k
5943 A29K VxWorks a29k-*-vxworks
5944 AMD 29000 embedded, using EBMON a29k-none-none
5945 AMD 29000 embedded with COFF a29k-none-coff
5946 AMD 29000 embedded with a.out a29k-none-aout
5948 testsuite/gdb.hp/gdb.threads-hp/ directory
5950 * REMOVED configurations and files
5952 TI TMS320C80 tic80-*-*
5954 PowerPC Solaris powerpcle-*-solaris*
5955 PowerPC Windows NT powerpcle-*-cygwin32
5956 PowerPC Netware powerpc-*-netware*
5957 Harris/CXUX m88k m88*-harris-cxux*
5958 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5959 ns32k-utek-sysv* ns32k-utek-*
5960 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5961 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5962 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5963 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5964 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5966 * Changes to command line processing
5968 The new `--args' feature can be used to specify command-line arguments
5969 for the inferior from gdb's command line.
5971 * Changes to key bindings
5973 There is a new `operate-and-get-next' function bound to `C-o'.
5975 *** Changes in GDB 5.1.1
5977 Fix compile problem on DJGPP.
5979 Fix a problem with floating-point registers on the i386 being
5982 Fix to stop GDB crashing on .debug_str debug info.
5984 Numerous documentation fixes.
5986 Numerous testsuite fixes.
5988 *** Changes in GDB 5.1:
5990 * New native configurations
5992 Alpha FreeBSD alpha*-*-freebsd*
5993 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5994 MIPS GNU/Linux mips*-*-linux*
5995 MIPS SGI Irix 6.x mips*-sgi-irix6*
5996 ia64 AIX ia64-*-aix*
5997 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6001 Motorola 68HC11 and 68HC12 m68hc11-elf
6003 UltraSparc running GNU/Linux sparc64-*-linux*
6005 * OBSOLETE configurations and files
6007 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6008 Harris/CXUX m88k m88*-harris-cxux*
6009 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6010 ns32k-utek-sysv* ns32k-utek-*
6011 TI TMS320C80 tic80-*-*
6013 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6014 PowerPC Solaris powerpcle-*-solaris*
6015 PowerPC Windows NT powerpcle-*-cygwin32
6016 PowerPC Netware powerpc-*-netware*
6017 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6018 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6019 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6020 Apple Macintosh (MPW) host N/A
6022 stuff.c (Program to stuff files into a specially prepared space in kdb)
6023 kdb-start.c (Main loop for the standalone kernel debugger)
6025 Configurations that have been declared obsolete in this release have
6026 been commented out. Unless there is activity to revive these
6027 configurations, the next release of GDB will have their sources
6028 permanently REMOVED.
6030 * REMOVED configurations and files
6032 Altos 3068 m68*-altos-*
6033 Convex c1-*-*, c2-*-*
6035 ARM RISCix arm-*-* (as host)
6039 * GDB has been converted to ISO C.
6041 GDB's source code has been converted to ISO C. In particular, the
6042 sources are fully protoized, and rely on standard headers being
6047 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6049 * The MI enabled by default.
6051 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6052 revised and enabled by default. Packages which use GDB as a debugging
6053 engine behind a UI or another front end are encouraged to switch to
6054 using the GDB/MI interface, instead of the old annotations interface
6055 which is now deprecated.
6057 * Support for debugging Pascal programs.
6059 GDB now includes support for debugging Pascal programs. The following
6060 main features are supported:
6062 - Pascal-specific data types such as sets;
6064 - automatic recognition of Pascal sources based on file-name
6067 - Pascal-style display of data types, variables, and functions;
6069 - a Pascal expression parser.
6071 However, some important features are not yet supported.
6073 - Pascal string operations are not supported at all;
6075 - there are some problems with boolean types;
6077 - Pascal type hexadecimal constants are not supported
6078 because they conflict with the internal variables format;
6080 - support for Pascal objects and classes is not full yet;
6082 - unlike Pascal, GDB is case-sensitive for symbol names.
6084 * Changes in completion.
6086 Commands such as `shell', `run' and `set args', which pass arguments
6087 to inferior programs, now complete on file names, similar to what
6088 users expect at the shell prompt.
6090 Commands which accept locations, such as `disassemble', `print',
6091 `breakpoint', `until', etc. now complete on filenames as well as
6092 program symbols. Thus, if you type "break foob TAB", and the source
6093 files linked into the programs include `foobar.c', that file name will
6094 be one of the candidates for completion. However, file names are not
6095 considered for completion after you typed a colon that delimits a file
6096 name from a name of a function in that file, as in "break foo.c:bar".
6098 `set demangle-style' completes on available demangling styles.
6100 * New platform-independent commands:
6102 It is now possible to define a post-hook for a command as well as a
6103 hook that runs before the command. For more details, see the
6104 documentation of `hookpost' in the GDB manual.
6106 * Changes in GNU/Linux native debugging.
6108 Support for debugging multi-threaded programs has been completely
6109 revised for all platforms except m68k and sparc. You can now debug as
6110 many threads as your system allows you to have.
6112 Attach/detach is supported for multi-threaded programs.
6114 Support for SSE registers was added for x86. This doesn't work for
6115 multi-threaded programs though.
6117 * Changes in MIPS configurations.
6119 Multi-arch support is enabled for all MIPS configurations.
6121 GDB can now be built as native debugger on SGI Irix 6.x systems for
6122 debugging n32 executables. (Debugging 64-bit executables is not yet
6125 * Unified support for hardware watchpoints in all x86 configurations.
6127 Most (if not all) native x86 configurations support hardware-assisted
6128 breakpoints and watchpoints in a unified manner. This support
6129 implements debug register sharing between watchpoints, which allows to
6130 put a virtually infinite number of watchpoints on the same address,
6131 and also supports watching regions up to 16 bytes with several debug
6134 The new maintenance command `maintenance show-debug-regs' toggles
6135 debugging print-outs in functions that insert, remove, and test
6136 watchpoints and hardware breakpoints.
6138 * Changes in the DJGPP native configuration.
6140 New command ``info dos sysinfo'' displays assorted information about
6141 the CPU, OS, memory, and DPMI server.
6143 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6144 display information about segment descriptors stored in GDT, LDT, and
6147 New commands ``info dos pde'' and ``info dos pte'' display entries
6148 from Page Directory and Page Tables (for now works with CWSDPMI only).
6149 New command ``info dos address-pte'' displays the Page Table entry for
6150 a given linear address.
6152 GDB can now pass command lines longer than 126 characters to the
6153 program being debugged (requires an update to the libdbg.a library
6154 which is part of the DJGPP development kit).
6156 DWARF2 debug info is now supported.
6158 It is now possible to `step' and `next' through calls to `longjmp'.
6160 * Changes in documentation.
6162 All GDB documentation was converted to GFDL, the GNU Free
6163 Documentation License.
6165 Tracepoints-related commands are now fully documented in the GDB
6168 TUI, the Text-mode User Interface, is now documented in the manual.
6170 Tracepoints-related commands are now fully documented in the GDB
6173 The "GDB Internals" manual now has an index. It also includes
6174 documentation of `ui_out' functions, GDB coding standards, x86
6175 hardware watchpoints, and memory region attributes.
6177 * GDB's version number moved to ``version.in''
6179 The Makefile variable VERSION has been replaced by the file
6180 ``version.in''. People creating GDB distributions should update the
6181 contents of this file.
6185 GUD support is now a standard part of the EMACS distribution.
6187 *** Changes in GDB 5.0:
6189 * Improved support for debugging FP programs on x86 targets
6191 Unified and much-improved support for debugging floating-point
6192 programs on all x86 targets. In particular, ``info float'' now
6193 displays the FP registers in the same format on all x86 targets, with
6194 greater level of detail.
6196 * Improvements and bugfixes in hardware-assisted watchpoints
6198 It is now possible to watch array elements, struct members, and
6199 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6200 on x86 targets no longer erroneously trigger when the address is
6203 * Improvements in the native DJGPP version of GDB
6205 The distribution now includes all the scripts and auxiliary files
6206 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6207 machines ``out of the box''.
6209 The DJGPP version can now debug programs that use signals. It is
6210 possible to catch signals that happened in the debuggee, deliver
6211 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6212 would kill the program being debugged.) Programs that hook hardware
6213 interrupts (keyboard, timer, etc.) can also be debugged.
6215 It is now possible to debug DJGPP programs that redirect their
6216 standard handles or switch them to raw (as opposed to cooked) mode, or
6217 even close them. The command ``run < foo > bar'' works as expected,
6218 and ``info terminal'' reports useful information about the debuggee's
6219 terminal, including raw/cooked mode, redirection, etc.
6221 The DJGPP version now uses termios functions for console I/O, which
6222 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6225 DOS-style file names with drive letters are now fully supported by
6228 It is now possible to debug DJGPP programs that switch their working
6229 directory. It is also possible to rerun the debuggee any number of
6230 times without restarting GDB; thus, you can use the same setup,
6231 breakpoints, etc. for many debugging sessions.
6233 * New native configurations
6235 ARM GNU/Linux arm*-*-linux*
6236 PowerPC GNU/Linux powerpc-*-linux*
6240 Motorola MCore mcore-*-*
6241 x86 VxWorks i[3456]86-*-vxworks*
6242 PowerPC VxWorks powerpc-*-vxworks*
6243 TI TMS320C80 tic80-*-*
6245 * OBSOLETE configurations
6247 Altos 3068 m68*-altos-*
6248 Convex c1-*-*, c2-*-*
6250 ARM RISCix arm-*-* (as host)
6253 Configurations that have been declared obsolete will be commented out,
6254 but the code will be left in place. If there is no activity to revive
6255 these configurations before the next release of GDB, the sources will
6256 be permanently REMOVED.
6258 * Gould support removed
6260 Support for the Gould PowerNode and NP1 has been removed.
6262 * New features for SVR4
6264 On SVR4 native platforms (such as Solaris), if you attach to a process
6265 without first loading a symbol file, GDB will now attempt to locate and
6266 load symbols from the running process's executable file.
6268 * Many C++ enhancements
6270 C++ support has been greatly improved. Overload resolution now works properly
6271 in almost all cases. RTTI support is on the way.
6273 * Remote targets can connect to a sub-program
6275 A popen(3) style serial-device has been added. This device starts a
6276 sub-process (such as a stand-alone simulator) and then communicates
6277 with that. The sub-program to run is specified using the syntax
6278 ``|<program> <args>'' vis:
6280 (gdb) set remotedebug 1
6281 (gdb) target extended-remote |mn10300-elf-sim program-args
6283 * MIPS 64 remote protocol
6285 A long standing bug in the mips64 remote protocol where by GDB
6286 expected certain 32 bit registers (ex SR) to be transfered as 32
6287 instead of 64 bits has been fixed.
6289 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6290 added to provide backward compatibility with older versions of GDB.
6292 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6294 The command ``set remotebinarydownload'' command has been replaced by
6295 ``set remote X-packet''. Other commands in ``set remote'' family
6296 include ``set remote P-packet''.
6298 * Breakpoint commands accept ranges.
6300 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6301 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6302 ``tracepoint passcount'' also accepts a range of tracepoints.
6304 * ``apropos'' command added.
6306 The ``apropos'' command searches through command names and
6307 documentation strings, printing out matches, making it much easier to
6308 try to find a command that does what you are looking for.
6312 A new machine oriented interface (MI) has been added to GDB. This
6313 interface is designed for debug environments running GDB as a separate
6314 process. This is part of the long term libGDB project. See the
6315 "GDB/MI" chapter of the GDB manual for further information. It can be
6316 enabled by configuring with:
6318 .../configure --enable-gdbmi
6320 *** Changes in GDB-4.18:
6322 * New native configurations
6324 HP-UX 10.20 hppa*-*-hpux10.20
6325 HP-UX 11.x hppa*-*-hpux11.0*
6326 M68K GNU/Linux m68*-*-linux*
6330 Fujitsu FR30 fr30-*-elf*
6331 Intel StrongARM strongarm-*-*
6332 Mitsubishi D30V d30v-*-*
6334 * OBSOLETE configurations
6336 Gould PowerNode, NP1 np1-*-*, pn-*-*
6338 Configurations that have been declared obsolete will be commented out,
6339 but the code will be left in place. If there is no activity to revive
6340 these configurations before the next release of GDB, the sources will
6341 be permanently REMOVED.
6345 As a compatibility experiment, GDB's source files buildsym.h and
6346 buildsym.c have been converted to pure standard C, no longer
6347 containing any K&R compatibility code. We believe that all systems in
6348 use today either come with a standard C compiler, or have a GCC port
6349 available. If this is not true, please report the affected
6350 configuration to bug-gdb@gnu.org immediately. See the README file for
6351 information about getting a standard C compiler if you don't have one
6356 GDB now uses readline 2.2.
6358 * set extension-language
6360 You can now control the mapping between filename extensions and source
6361 languages by using the `set extension-language' command. For instance,
6362 you can ask GDB to treat .c files as C++ by saying
6363 set extension-language .c c++
6364 The command `info extensions' lists all of the recognized extensions
6365 and their associated languages.
6367 * Setting processor type for PowerPC and RS/6000
6369 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6370 you can use the `set processor' command to specify what variant of the
6371 PowerPC family you are debugging. The command
6375 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6376 following PowerPC and RS6000 variants:
6378 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6379 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6381 403GC IBM PowerPC 403GC
6382 505 Motorola PowerPC 505
6383 860 Motorola PowerPC 860 or 850
6384 601 Motorola PowerPC 601
6385 602 Motorola PowerPC 602
6386 603 Motorola/IBM PowerPC 603 or 603e
6387 604 Motorola PowerPC 604 or 604e
6388 750 Motorola/IBM PowerPC 750 or 750
6390 At the moment, this command just tells GDB what to name the
6391 special-purpose processor registers. Since almost all the affected
6392 registers are inaccessible to user-level programs, this command is
6393 only useful for remote debugging in its present form.
6397 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6398 more extensive support for HP-UX. Added features include shared
6399 library support, kernel threads and hardware watchpoints for 11.00,
6400 support for HP's ANSI C and C++ compilers, and a compatibility mode
6401 for xdb and dbx commands.
6405 HP's donation includes the new concept of catchpoints, which is a
6406 generalization of the old catch command. On HP-UX, it is now possible
6407 to catch exec, fork, and vfork, as well as library loading.
6409 This means that the existing catch command has changed; its first
6410 argument now specifies the type of catch to be set up. See the
6411 output of "help catch" for a list of catchpoint types.
6413 * Debugging across forks
6415 On HP-UX, you can choose which process to debug when a fork() happens
6420 HP has donated a curses-based terminal user interface (TUI). To get
6421 it, build with --enable-tui. Although this can be enabled for any
6422 configuration, at present it only works for native HP debugging.
6424 * GDB remote protocol additions
6426 A new protocol packet 'X' that writes binary data is now available.
6427 Default behavior is to try 'X', then drop back to 'M' if the stub
6428 fails to respond. The settable variable `remotebinarydownload'
6429 allows explicit control over the use of 'X'.
6431 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6432 full 64-bit address. The command
6434 set remoteaddresssize 32
6436 can be used to revert to the old behaviour. For existing remote stubs
6437 the change should not be noticed, as the additional address information
6440 In order to assist in debugging stubs, you may use the maintenance
6441 command `packet' to send any text string to the stub. For instance,
6443 maint packet heythere
6445 sends the packet "$heythere#<checksum>". Note that it is very easy to
6446 disrupt a debugging session by sending the wrong packet at the wrong
6449 The compare-sections command allows you to compare section data on the
6450 target to what is in the executable file without uploading or
6451 downloading, by comparing CRC checksums.
6453 * Tracing can collect general expressions
6455 You may now collect general expressions at tracepoints. This requires
6456 further additions to the target-side stub; see tracepoint.c and
6457 doc/agentexpr.texi for further details.
6459 * mask-address variable for Mips
6461 For Mips targets, you may control the zeroing of the upper 32 bits of
6462 a 64-bit address by entering `set mask-address on'. This is mainly
6463 of interest to users of embedded R4xxx and R5xxx processors.
6465 * Higher serial baud rates
6467 GDB's serial code now allows you to specify baud rates 57600, 115200,
6468 230400, and 460800 baud. (Note that your host system may not be able
6469 to achieve all of these rates.)
6473 The i960 configuration now includes an initial implementation of a
6474 builtin simulator, contributed by Jim Wilson.
6477 *** Changes in GDB-4.17:
6479 * New native configurations
6481 Alpha GNU/Linux alpha*-*-linux*
6482 Unixware 2.x i[3456]86-unixware2*
6483 Irix 6.x mips*-sgi-irix6*
6484 PowerPC GNU/Linux powerpc-*-linux*
6485 PowerPC Solaris powerpcle-*-solaris*
6486 Sparc GNU/Linux sparc-*-linux*
6487 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6491 Argonaut Risc Chip (ARC) arc-*-*
6492 Hitachi H8/300S h8300*-*-*
6493 Matsushita MN10200 w/simulator mn10200-*-*
6494 Matsushita MN10300 w/simulator mn10300-*-*
6495 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6496 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6497 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6498 Mitsubishi D10V w/simulator d10v-*-*
6499 Mitsubishi M32R/D w/simulator m32r-*-elf*
6500 Tsqware Sparclet sparclet-*-*
6501 NEC V850 w/simulator v850-*-*
6503 * New debugging protocols
6505 ARM with RDI protocol arm*-*-*
6506 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6507 DDB and LSI variants of PMON protocol mips*-*-*
6508 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6509 PowerPC with SDS protocol powerpc{,le}-*-eabi
6510 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6514 All configurations can now understand and use the DWARF 2 debugging
6515 format. The choice is automatic, if the symbol file contains DWARF 2
6520 GDB now includes basic Java language support. This support is
6521 only useful with Java compilers that produce native machine code.
6523 * solib-absolute-prefix and solib-search-path
6525 For SunOS and SVR4 shared libraries, you may now set the prefix for
6526 loading absolute shared library symbol files, and the search path for
6527 locating non-absolute shared library symbol files.
6529 * Live range splitting
6531 GDB can now effectively debug code for which GCC has performed live
6532 range splitting as part of its optimization. See gdb/doc/LRS for
6533 more details on the expected format of the stabs information.
6537 GDB's support for the GNU Hurd, including thread debugging, has been
6538 updated to work with current versions of the Hurd.
6542 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6543 instruction set. ARM GDB automatically detects when Thumb
6544 instructions are in use, and adjusts disassembly and backtracing
6549 GDB's MIPS target configurations now handle the MIP16 16-bit
6554 GDB now includes support for overlays; if an executable has been
6555 linked such that multiple sections are based at the same address, GDB
6556 will decide which section to use for symbolic info. You can choose to
6557 control the decision manually, using overlay commands, or implement
6558 additional target-side support and use "overlay load-target" to bring
6559 in the overlay mapping. Do "help overlay" for more detail.
6563 The command "info symbol <address>" displays information about
6564 the symbol at the specified address.
6568 The standard remote protocol now includes an extension that allows
6569 asynchronous collection and display of trace data. This requires
6570 extensive support in the target-side debugging stub. Tracing mode
6571 includes a new interaction mode in GDB and new commands: see the
6572 file tracepoint.c for more details.
6576 Configurations for embedded MIPS now include a simulator contributed
6577 by Cygnus Solutions. The simulator supports the instruction sets
6578 of most MIPS variants.
6582 Sparc configurations may now include the ERC32 simulator contributed
6583 by the European Space Agency. The simulator is not built into
6584 Sparc targets by default; configure with --enable-sim to include it.
6588 For target configurations that may include multiple variants of a
6589 basic architecture (such as MIPS and SH), you may now set the
6590 architecture explicitly. "set arch" sets, "info arch" lists
6591 the possible architectures.
6593 *** Changes in GDB-4.16:
6595 * New native configurations
6597 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6598 M68K NetBSD m68k-*-netbsd*
6599 PowerPC AIX 4.x powerpc-*-aix*
6600 PowerPC MacOS powerpc-*-macos*
6601 PowerPC Windows NT powerpcle-*-cygwin32
6602 RS/6000 AIX 4.x rs6000-*-aix4*
6606 ARM with RDP protocol arm-*-*
6607 I960 with MON960 i960-*-coff
6608 MIPS VxWorks mips*-*-vxworks*
6609 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6610 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6612 Matra Sparclet sparclet-*-*
6616 The powerpc-eabi configuration now includes the PSIM simulator,
6617 contributed by Andrew Cagney, with assistance from Mike Meissner.
6618 PSIM is a very elaborate model of the PowerPC, including not only
6619 basic instruction set execution, but also details of execution unit
6620 performance and I/O hardware. See sim/ppc/README for more details.
6624 GDB now works with Solaris 2.5.
6626 * Windows 95/NT native
6628 GDB will now work as a native debugger on Windows 95 and Windows NT.
6629 To build it from source, you must use the "gnu-win32" environment,
6630 which uses a DLL to emulate enough of Unix to run the GNU tools.
6631 Further information, binaries, and sources are available at
6632 ftp.cygnus.com, under pub/gnu-win32.
6634 * dont-repeat command
6636 If a user-defined command includes the command `dont-repeat', then the
6637 command will not be repeated if the user just types return. This is
6638 useful if the command is time-consuming to run, so that accidental
6639 extra keystrokes don't run the same command many times.
6641 * Send break instead of ^C
6643 The standard remote protocol now includes an option to send a break
6644 rather than a ^C to the target in order to interrupt it. By default,
6645 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6647 * Remote protocol timeout
6649 The standard remote protocol includes a new variable `remotetimeout'
6650 that allows you to set the number of seconds before GDB gives up trying
6651 to read from the target. The default value is 2.
6653 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6655 By default GDB will automatically keep track of objects as they are
6656 loaded and unloaded by the dynamic linker. By using the command `set
6657 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6658 when shared library events occur, thus allowing you to set breakpoints
6659 in shared libraries which are explicitly loaded by the inferior.
6661 Note this feature does not work on hpux8. On hpux9 you must link
6662 /usr/lib/end.o into your program. This feature should work
6663 automatically on hpux10.
6665 * Irix 5.x hardware watchpoint support
6667 Irix 5 configurations now support the use of hardware watchpoints.
6669 * Mips protocol "SYN garbage limit"
6671 When debugging a Mips target using the `target mips' protocol, you
6672 may set the number of characters that GDB will ignore by setting
6673 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6674 every character. The default value is 1050.
6676 * Recording and replaying remote debug sessions
6678 If you set `remotelogfile' to the name of a file, gdb will write to it
6679 a recording of a remote debug session. This recording may then be
6680 replayed back to gdb using "gdbreplay". See gdbserver/README for
6681 details. This is useful when you have a problem with GDB while doing
6682 remote debugging; you can make a recording of the session and send it
6683 to someone else, who can then recreate the problem.
6685 * Speedups for remote debugging
6687 GDB includes speedups for downloading and stepping MIPS systems using
6688 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6689 and more efficient S-record downloading.
6691 * Memory use reductions and statistics collection
6693 GDB now uses less memory and reports statistics about memory usage.
6694 Try the `maint print statistics' command, for example.
6696 *** Changes in GDB-4.15:
6698 * Psymtabs for XCOFF
6700 The symbol reader for AIX GDB now uses partial symbol tables. This
6701 can greatly improve startup time, especially for large executables.
6703 * Remote targets use caching
6705 Remote targets now use a data cache to speed up communication with the
6706 remote side. The data cache could lead to incorrect results because
6707 it doesn't know about volatile variables, thus making it impossible to
6708 debug targets which use memory mapped I/O devices. `set remotecache
6709 off' turns the data cache off.
6711 * Remote targets may have threads
6713 The standard remote protocol now includes support for multiple threads
6714 in the target system, using new protocol commands 'H' and 'T'. See
6715 gdb/remote.c for details.
6719 If GDB is configured with `--enable-netrom', then it will include
6720 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6721 acts as though it is a bank of ROM on the target board, but you can
6722 write into it over the network. GDB's support consists only of
6723 support for fast loading into the emulated ROM; to debug, you must use
6724 another protocol, such as standard remote protocol. The usual
6725 sequence is something like
6727 target nrom <netrom-hostname>
6729 target remote <netrom-hostname>:1235
6733 GDB now includes support for the Apple Macintosh, as a host only. It
6734 may be run as either an MPW tool or as a standalone application, and
6735 it can debug through the serial port. All the usual GDB commands are
6736 available, but to the target command, you must supply "serial" as the
6737 device type instead of "/dev/ttyXX". See mpw-README in the main
6738 directory for more information on how to build. The MPW configuration
6739 scripts */mpw-config.in support only a few targets, and only the
6740 mips-idt-ecoff target has been tested.
6744 GDB configuration now uses autoconf. This is not user-visible,
6745 but does simplify configuration and building.
6749 GDB now supports hpux10.
6751 *** Changes in GDB-4.14:
6753 * New native configurations
6755 x86 FreeBSD i[345]86-*-freebsd
6756 x86 NetBSD i[345]86-*-netbsd
6757 NS32k NetBSD ns32k-*-netbsd
6758 Sparc NetBSD sparc-*-netbsd
6762 A29K VxWorks a29k-*-vxworks
6763 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6764 CPU32 EST-300 emulator m68*-*-est*
6765 PowerPC ELF powerpc-*-elf
6768 * Alpha OSF/1 support for procfs
6770 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6771 possible to attach to running processes. As the mounting of the /proc
6772 filesystem is optional on the Alpha, GDB automatically determines
6773 the availability of /proc during startup. This can lead to problems
6774 if /proc is unmounted after GDB has been started.
6776 * Arguments to user-defined commands
6778 User commands may accept up to 10 arguments separated by whitespace.
6779 Arguments are accessed within the user command via $arg0..$arg9. A
6782 print $arg0 + $arg1 + $arg2
6784 To execute the command use:
6787 Defines the command "adder" which prints the sum of its three arguments.
6788 Note the arguments are text substitutions, so they may reference variables,
6789 use complex expressions, or even perform inferior function calls.
6791 * New `if' and `while' commands
6793 This makes it possible to write more sophisticated user-defined
6794 commands. Both commands take a single argument, which is the
6795 expression to evaluate, and must be followed by the commands to
6796 execute, one per line, if the expression is nonzero, the list being
6797 terminated by the word `end'. The `if' command list may include an
6798 `else' word, which causes the following commands to be executed only
6799 if the expression is zero.
6801 * Fortran source language mode
6803 GDB now includes partial support for Fortran 77. It will recognize
6804 Fortran programs and can evaluate a subset of Fortran expressions, but
6805 variables and functions may not be handled correctly. GDB will work
6806 with G77, but does not yet know much about symbols emitted by other
6809 * Better HPUX support
6811 Most debugging facilities now work on dynamic executables for HPPAs
6812 running hpux9 or later. You can attach to running dynamically linked
6813 processes, but by default the dynamic libraries will be read-only, so
6814 for instance you won't be able to put breakpoints in them. To change
6815 that behavior do the following before running the program:
6821 This will cause the libraries to be mapped private and read-write.
6822 To revert to the normal behavior, do this:
6828 You cannot set breakpoints or examine data in the library until after
6829 the library is loaded if the function/data symbols do not have
6832 GDB can now also read debug symbols produced by the HP C compiler on
6833 HPPAs (sorry, no C++, Fortran or 68k support).
6835 * Target byte order now dynamically selectable
6837 You can choose which byte order to use with a target system, via the
6838 commands "set endian big" and "set endian little", and you can see the
6839 current setting by using "show endian". You can also give the command
6840 "set endian auto", in which case GDB will use the byte order
6841 associated with the executable. Currently, only embedded MIPS
6842 configurations support dynamic selection of target byte order.
6844 * New DOS host serial code
6846 This version uses DPMI interrupts to handle buffered I/O, so you
6847 no longer need to run asynctsr when debugging boards connected to
6850 *** Changes in GDB-4.13:
6852 * New "complete" command
6854 This lists all the possible completions for the rest of the line, if it
6855 were to be given as a command itself. This is intended for use by emacs.
6857 * Trailing space optional in prompt
6859 "set prompt" no longer adds a space for you after the prompt you set. This
6860 allows you to set a prompt which ends in a space or one that does not.
6862 * Breakpoint hit counts
6864 "info break" now displays a count of the number of times the breakpoint
6865 has been hit. This is especially useful in conjunction with "ignore"; you
6866 can ignore a large number of breakpoint hits, look at the breakpoint info
6867 to see how many times the breakpoint was hit, then run again, ignoring one
6868 less than that number, and this will get you quickly to the last hit of
6871 * Ability to stop printing at NULL character
6873 "set print null-stop" will cause GDB to stop printing the characters of
6874 an array when the first NULL is encountered. This is useful when large
6875 arrays actually contain only short strings.
6877 * Shared library breakpoints
6879 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6880 breakpoints in shared libraries before the executable is run.
6882 * Hardware watchpoints
6884 There is a new hardware breakpoint for the watch command for sparclite
6885 targets. See gdb/sparclite/hw_breakpoint.note.
6887 Hardware watchpoints are also now supported under GNU/Linux.
6891 Annotations have been added. These are for use with graphical interfaces,
6892 and are still experimental. Currently only gdba.el uses these.
6894 * Improved Irix 5 support
6896 GDB now works properly with Irix 5.2.
6898 * Improved HPPA support
6900 GDB now works properly with the latest GCC and GAS.
6902 * New native configurations
6904 Sequent PTX4 i[34]86-sequent-ptx4
6905 HPPA running OSF/1 hppa*-*-osf*
6906 Atari TT running SVR4 m68*-*-sysv4*
6907 RS/6000 LynxOS rs6000-*-lynxos*
6911 OS/9000 i[34]86-*-os9k
6912 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6915 * Hitachi SH7000 and E7000-PC ICE support
6917 There is now support for communicating with the Hitachi E7000-PC ICE.
6918 This is available automatically when GDB is configured for the SH.
6922 As usual, a variety of small fixes and improvements, both generic
6923 and configuration-specific. See the ChangeLog for more detail.
6925 *** Changes in GDB-4.12:
6927 * Irix 5 is now supported
6931 GDB-4.12 on the HPPA has a number of changes which make it unable
6932 to debug the output from the currently released versions of GCC and
6933 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6934 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6935 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6938 *** Changes in GDB-4.11:
6940 * User visible changes:
6944 The "set remotedebug" option is now consistent between the mips remote
6945 target, remote targets using the gdb-specific protocol, UDI (AMD's
6946 debug protocol for the 29k) and the 88k bug monitor. It is now an
6947 integer specifying a debug level (normally 0 or 1, but 2 means more
6948 debugging info for the mips target).
6950 * DEC Alpha native support
6952 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6953 debug info, but GDB works fairly well with the DEC compiler and should
6954 work with a future GCC release. See the README file for a few
6955 Alpha-specific notes.
6957 * Preliminary thread implementation
6959 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6961 * LynxOS native and target support for 386
6963 This release has been hosted on LynxOS 2.2, and also can be configured
6964 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6967 * Improvements in C++ mangling/demangling.
6969 This release has much better g++ debugging, specifically in name
6970 mangling/demangling, virtual function calls, print virtual table,
6971 call methods, ...etc.
6973 *** Changes in GDB-4.10:
6975 * User visible changes:
6977 Remote debugging using the GDB-specific (`target remote') protocol now
6978 supports the `load' command. This is only useful if you have some
6979 other way of getting the stub to the target system, and you can put it
6980 somewhere in memory where it won't get clobbered by the download.
6982 Filename completion now works.
6984 When run under emacs mode, the "info line" command now causes the
6985 arrow to point to the line specified. Also, "info line" prints
6986 addresses in symbolic form (as well as hex).
6988 All vxworks based targets now support a user settable option, called
6989 vxworks-timeout. This option represents the number of seconds gdb
6990 should wait for responses to rpc's. You might want to use this if
6991 your vxworks target is, perhaps, a slow software simulator or happens
6992 to be on the far side of a thin network line.
6996 This release contains support for using a DEC alpha as a GDB host for
6997 cross debugging. Native alpha debugging is not supported yet.
7000 *** Changes in GDB-4.9:
7004 This is the first GDB release which is accompanied by a matching testsuite.
7005 The testsuite requires installation of dejagnu, which should be available
7006 via ftp from most sites that carry GNU software.
7010 'Cfront' style demangling has had its name changed to 'ARM' style, to
7011 emphasize that it was written from the specifications in the C++ Annotated
7012 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7013 disclaimers, it still generated too much confusion with users attempting to
7014 use gdb with AT&T cfront.
7018 GDB now uses a standard remote interface to a simulator library.
7019 So far, the library contains simulators for the Zilog Z8001/2, the
7020 Hitachi H8/300, H8/500 and Super-H.
7022 * New targets supported
7024 H8/300 simulator h8300-hitachi-hms or h8300hms
7025 H8/500 simulator h8500-hitachi-hms or h8500hms
7026 SH simulator sh-hitachi-hms or sh
7027 Z8000 simulator z8k-zilog-none or z8ksim
7028 IDT MIPS board over serial line mips-idt-ecoff
7030 Cross-debugging to GO32 targets is supported. It requires a custom
7031 version of the i386-stub.c module which is integrated with the
7032 GO32 memory extender.
7034 * New remote protocols
7036 MIPS remote debugging protocol.
7038 * New source languages supported
7040 This version includes preliminary support for Chill, a Pascal like language
7041 used by telecommunications companies. Chill support is also being integrated
7042 into the GNU compiler, but we don't know when it will be publically available.
7045 *** Changes in GDB-4.8:
7047 * HP Precision Architecture supported
7049 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7050 version of this support was available as a set of patches from the
7051 University of Utah. GDB does not support debugging of programs
7052 compiled with the HP compiler, because HP will not document their file
7053 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7054 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7056 Many problems in the preliminary version have been fixed.
7058 * Faster and better demangling
7060 We have improved template demangling and fixed numerous bugs in the GNU style
7061 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7062 character types (wchar_t) are now supported. Demangling of each symbol is now
7063 only done once, and is cached when the symbol table for a file is read in.
7064 This results in a small increase in memory usage for C programs, a moderate
7065 increase in memory usage for C++ programs, and a fantastic speedup in
7068 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7069 from the specifications in the Annotated Reference Manual, which AT&T's
7070 compiler does not actually implement.
7072 * G++ multiple inheritance compiler problem
7074 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7075 inheritance lattices was reworked to properly discover ambiguities. We
7076 recently found an example which causes this new algorithm to fail in a
7077 very subtle way, producing bad debug information for those classes.
7078 The file 'gcc.patch' (in this directory) can be applied to gcc to
7079 circumvent the problem. A future GCC release will contain a complete
7082 The previous G++ debug info problem (mentioned below for the gdb-4.7
7083 release) is fixed in gcc version 2.3.2.
7085 * Improved configure script
7087 The `configure' script will now attempt to guess your system type if
7088 you don't supply a host system type. The old scheme of supplying a
7089 host system triplet is preferable over using this. All the magic is
7090 done in the new `config.guess' script. Examine it for details.
7092 We have also brought our configure script much more in line with the FSF's
7093 version. It now supports the --with-xxx options. In particular,
7094 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7095 The resulting GDB will not be able to read arbitrary object file formats --
7096 only the format ``expected'' to be used on the configured target system.
7097 We hope to make this the default in a future release.
7099 * Documentation improvements
7101 There's new internal documentation on how to modify GDB, and how to
7102 produce clean changes to the code. We implore people to read it
7103 before submitting changes.
7105 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7106 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7107 `info' files are also provided. To build `info' files from scratch,
7108 you will need the latest `makeinfo' release, which will be available in
7109 a future texinfo-X.Y release.
7111 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7112 We're not sure exactly which versions have this problem, but it has
7113 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7114 or better. If that isn't possible, there is a patch in
7115 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7116 around this problem.
7120 GDB now supports array constants that can be used in expressions typed in by
7121 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7122 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7125 The new directory `gdb/sparclite' contains a program that demonstrates
7126 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7128 * New native hosts supported
7130 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7131 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7133 * New targets supported
7135 AMD 29k family via UDI a29k-amd-udi or udi29k
7137 * New file formats supported
7139 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7140 HPUX core files, and SCO 3.2v2 core files.
7144 Attaching to processes now works again; thanks for the many bug reports.
7146 We have also stomped on a bunch of core dumps caused by
7147 printf_filtered("%s") problems.
7149 We eliminated a copyright problem on the rpc and ptrace header files
7150 for VxWorks, which was discovered at the last minute during the 4.7
7151 release. You should now be able to build a VxWorks GDB.
7153 You can now interrupt gdb while an attached process is running. This
7154 will cause the attached process to stop, and give control back to GDB.
7156 We fixed problems caused by using too many file descriptors
7157 for reading symbols from object files and libraries. This was
7158 especially a problem for programs that used many (~100) shared
7161 The `step' command now only enters a subroutine if there is line number
7162 information for the subroutine. Otherwise it acts like the `next'
7163 command. Previously, `step' would enter subroutines if there was
7164 any debugging information about the routine. This avoids problems
7165 when using `cc -g1' on MIPS machines.
7167 * Internal improvements
7169 GDB's internal interfaces have been improved to make it easier to support
7170 debugging of multiple languages in the future.
7172 GDB now uses a common structure for symbol information internally.
7173 Minimal symbols (derived from linkage symbols in object files), partial
7174 symbols (from a quick scan of debug information), and full symbols
7175 contain a common subset of information, making it easier to write
7176 shared code that handles any of them.
7178 * New command line options
7180 We now accept --silent as an alias for --quiet.
7184 The memory-mapped-malloc library is now licensed under the GNU Library
7185 General Public License.
7187 *** Changes in GDB-4.7:
7189 * Host/native/target split
7191 GDB has had some major internal surgery to untangle the support for
7192 hosts and remote targets. Now, when you configure GDB for a remote
7193 target, it will no longer load in all of the support for debugging
7194 local programs on the host. When fully completed and tested, this will
7195 ensure that arbitrary host/target combinations are possible.
7197 The primary conceptual shift is to separate the non-portable code in
7198 GDB into three categories. Host specific code is required any time GDB
7199 is compiled on that host, regardless of the target. Target specific
7200 code relates to the peculiarities of the target, but can be compiled on
7201 any host. Native specific code is everything else: it can only be
7202 built when the host and target are the same system. Child process
7203 handling and core file support are two common `native' examples.
7205 GDB's use of /proc for controlling Unix child processes is now cleaner.
7206 It has been split out into a single module under the `target_ops' vector,
7207 plus two native-dependent functions for each system that uses /proc.
7209 * New hosts supported
7211 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7212 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7213 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7215 * New targets supported
7217 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7218 68030 and CPU32 m68030-*-*, m68332-*-*
7220 * New native hosts supported
7222 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7223 (386bsd is not well tested yet)
7224 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7226 * New file formats supported
7228 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7229 supports reading of `a.out.adobe' object files, which are an a.out
7230 format extended with minimal information about multiple sections.
7234 `show copying' is the same as the old `info copying'.
7235 `show warranty' is the same as `info warrantee'.
7236 These were renamed for consistency. The old commands continue to work.
7238 `info handle' is a new alias for `info signals'.
7240 You can now define pre-command hooks, which attach arbitrary command
7241 scripts to any command. The commands in the hook will be executed
7242 prior to the user's command. You can also create a hook which will be
7243 executed whenever the program stops. See gdb.texinfo.
7247 We now deal with Cfront style name mangling, and can even extract type
7248 info from mangled symbols. GDB can automatically figure out which
7249 symbol mangling style your C++ compiler uses.
7251 Calling of methods and virtual functions has been improved as well.
7255 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7256 fixed. This was due to mishandling of the extra N_SO stabs output
7259 We also finally got Ultrix 4.2 running in house, and fixed core file
7260 support, with help from a dozen people on the net.
7262 John M. Farrell discovered that the reason that single-stepping was so
7263 slow on all of the Mips based platforms (primarily SGI and DEC) was
7264 that we were trying to demangle and lookup a symbol used for internal
7265 purposes on every instruction that was being stepped through. Changing
7266 the name of that symbol so that it couldn't be mistaken for a C++
7267 mangled symbol sped things up a great deal.
7269 Rich Pixley sped up symbol lookups in general by getting much smarter
7270 about when C++ symbol mangling is necessary. This should make symbol
7271 completion (TAB on the command line) much faster. It's not as fast as
7272 we'd like, but it's significantly faster than gdb-4.6.
7276 A new user controllable variable 'call_scratch_address' can
7277 specify the location of a scratch area to be used when GDB
7278 calls a function in the target. This is necessary because the
7279 usual method of putting the scratch area on the stack does not work
7280 in systems that have separate instruction and data spaces.
7282 We integrated changes to support the 29k UDI (Universal Debugger
7283 Interface), but discovered at the last minute that we didn't have all
7284 of the appropriate copyright paperwork. We are working with AMD to
7285 resolve this, and hope to have it available soon.
7289 We have sped up the remote serial line protocol, especially for targets
7290 with lots of registers. It now supports a new `expedited status' ('T')
7291 message which can be used in place of the existing 'S' status message.
7292 This allows the remote stub to send only the registers that GDB
7293 needs to make a quick decision about single-stepping or conditional
7294 breakpoints, eliminating the need to fetch the entire register set for
7295 each instruction being stepped through.
7297 The GDB remote serial protocol now implements a write-through cache for
7298 registers, only re-reading the registers if the target has run.
7300 There is also a new remote serial stub for SPARC processors. You can
7301 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7302 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7303 processor with a serial port.
7307 Configure.in files have become much easier to read and modify. A new
7308 `table driven' format makes it more obvious what configurations are
7309 supported, and what files each one uses.
7313 There is a new opcodes library which will eventually contain all of the
7314 disassembly routines and opcode tables. At present, it only contains
7315 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7316 disassembler (binutils/objdump) to share these routines.
7318 The libiberty library is now copylefted under the GNU Library General
7319 Public License. This allows more liberal use, and was done so libg++
7320 can use it. This makes no difference to GDB, since the Library License
7321 grants all the rights from the General Public License.
7325 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7326 reference to the stabs symbol info used by the debugger. It is (as far
7327 as we know) the only published document on this fascinating topic. We
7328 encourage you to read it, compare it to the stabs information on your
7329 system, and send improvements on the document in general (to
7330 bug-gdb@prep.ai.mit.edu).
7332 And, of course, many bugs have been fixed.
7335 *** Changes in GDB-4.6:
7337 * Better support for C++ function names
7339 GDB now accepts as input the "demangled form" of C++ overloaded function
7340 names and member function names, and can do command completion on such names
7341 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7342 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7343 Make use of command completion, it is your friend.
7345 GDB also now accepts a variety of C++ mangled symbol formats. They are
7346 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7347 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7348 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7349 for the list of formats.
7351 * G++ symbol mangling problem
7353 Recent versions of gcc have a bug in how they emit debugging information for
7354 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7355 directory) can be applied to gcc to fix the problem. Alternatively, if you
7356 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7357 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7358 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7361 * New 'maintenance' command
7363 All of the commands related to hacking GDB internals have been moved out of
7364 the main command set, and now live behind the 'maintenance' command. This
7365 can also be abbreviated as 'mt'. The following changes were made:
7367 dump-me -> maintenance dump-me
7368 info all-breakpoints -> maintenance info breakpoints
7369 printmsyms -> maintenance print msyms
7370 printobjfiles -> maintenance print objfiles
7371 printpsyms -> maintenance print psymbols
7372 printsyms -> maintenance print symbols
7374 The following commands are new:
7376 maintenance demangle Call internal GDB demangler routine to
7377 demangle a C++ link name and prints the result.
7378 maintenance print type Print a type chain for a given symbol
7380 * Change to .gdbinit file processing
7382 We now read the $HOME/.gdbinit file before processing the argv arguments
7383 (e.g. reading symbol files or core files). This allows global parameters to
7384 be set, which will apply during the symbol reading. The ./.gdbinit is still
7385 read after argv processing.
7387 * New hosts supported
7389 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7391 GNU/Linux support i386-unknown-linux or linux
7393 We are also including code to support the HP/PA running BSD and HPUX. This
7394 is almost guaranteed not to work, as we didn't have time to test or build it
7395 for this release. We are including it so that the more adventurous (or
7396 masochistic) of you can play with it. We also had major problems with the
7397 fact that the compiler that we got from HP doesn't support the -g option.
7400 * New targets supported
7402 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7404 * More smarts about finding #include files
7406 GDB now remembers the compilation directory for all include files, and for
7407 all files from which C is generated (like yacc and lex sources). This
7408 greatly improves GDB's ability to find yacc/lex sources, and include files,
7409 especially if you are debugging your program from a directory different from
7410 the one that contains your sources.
7412 We also fixed a bug which caused difficulty with listing and setting
7413 breakpoints in include files which contain C code. (In the past, you had to
7414 try twice in order to list an include file that you hadn't looked at before.)
7416 * Interesting infernals change
7418 GDB now deals with arbitrary numbers of sections, where the symbols for each
7419 section must be relocated relative to that section's landing place in the
7420 target's address space. This work was needed to support ELF with embedded
7421 stabs used by Solaris-2.0.
7423 * Bug fixes (of course!)
7425 There have been loads of fixes for the following things:
7426 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7427 i960, stabs, DOS(GO32), procfs, etc...
7429 See the ChangeLog for details.
7431 *** Changes in GDB-4.5:
7433 * New machines supported (host and target)
7435 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7437 SGI Irix-4.x mips-sgi-irix4 or iris4
7439 * New malloc package
7441 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7442 Mmalloc is capable of handling multiple heaps of memory. It is also
7443 capable of saving a heap to a file, and then mapping it back in later.
7444 This can be used to greatly speedup the startup of GDB by using a
7445 pre-parsed symbol table which lives in a mmalloc managed heap. For
7446 more details, please read mmalloc/mmalloc.texi.
7450 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7451 'help info proc' for details.
7453 * MIPS ecoff symbol table format
7455 The code that reads MIPS symbol table format is now supported on all hosts.
7456 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7459 * File name changes for MS-DOS
7461 Many files in the config directories have been renamed to make it easier to
7462 support GDB on MS-DOSe systems (which have very restrictive file name
7463 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7464 environment) is close to working but has some remaining problems. Note
7465 that debugging of DOS programs is not supported, due to limitations
7466 in the ``operating system'', but it can be used to host cross-debugging.
7468 * Cross byte order fixes
7470 Many fixes have been made to support cross debugging of Sparc and MIPS
7471 targets from hosts whose byte order differs.
7473 * New -mapped and -readnow options
7475 If memory-mapped files are available on your system through the 'mmap'
7476 system call, you can use the -mapped option on the `file' or
7477 `symbol-file' commands to cause GDB to write the symbols from your
7478 program into a reusable file. If the program you are debugging is
7479 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7480 Future GDB debugging sessions will notice the presence of this file,
7481 and will quickly map in symbol information from it, rather than reading
7482 the symbol table from the executable program. Using the '-mapped'
7483 option in a GDB `file' or `symbol-file' command has the same effect as
7484 starting GDB with the '-mapped' command-line option.
7486 You can cause GDB to read the entire symbol table immediately by using
7487 the '-readnow' option with any of the commands that load symbol table
7488 information (or on the GDB command line). This makes the command
7489 slower, but makes future operations faster.
7491 The -mapped and -readnow options are typically combined in order to
7492 build a `fred.syms' file that contains complete symbol information.
7493 A simple GDB invocation to do nothing but build a `.syms' file for future
7496 gdb -batch -nx -mapped -readnow programname
7498 The `.syms' file is specific to the host machine on which GDB is run.
7499 It holds an exact image of GDB's internal symbol table. It cannot be
7500 shared across multiple host platforms.
7502 * longjmp() handling
7504 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7505 siglongjmp() without losing control. This feature has not yet been ported to
7506 all systems. It currently works on many 386 platforms, all MIPS-based
7507 platforms (SGI, DECstation, etc), and Sun3/4.
7511 Preliminary work has been put in to support the new Solaris OS from Sun. At
7512 this time, it can control and debug processes, but it is not capable of
7517 As always, many many bug fixes. The major areas were with g++, and mipsread.
7518 People using the MIPS-based platforms should experience fewer mysterious
7519 crashes and trashed symbol tables.
7521 *** Changes in GDB-4.4:
7523 * New machines supported (host and target)
7525 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7527 BSD Reno on Vax vax-dec-bsd
7528 Ultrix on Vax vax-dec-ultrix
7530 * New machines supported (target)
7532 AMD 29000 embedded, using EBMON a29k-none-none
7536 GDB continues to improve its handling of C++. `References' work better.
7537 The demangler has also been improved, and now deals with symbols mangled as
7538 per the Annotated C++ Reference Guide.
7540 GDB also now handles `stabs' symbol information embedded in MIPS
7541 `ecoff' symbol tables. Since the ecoff format was not easily
7542 extensible to handle new languages such as C++, this appeared to be a
7543 good way to put C++ debugging info into MIPS binaries. This option
7544 will be supported in the GNU C compiler, version 2, when it is
7547 * New features for SVR4
7549 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7550 shared libraries. Debugging dynamically linked programs should present
7551 only minor differences from debugging statically linked programs.
7553 The `info proc' command will print out information about any process
7554 on an SVR4 system (including the one you are debugging). At the moment,
7555 it prints the address mappings of the process.
7557 If you bring up GDB on another SVR4 system, please send mail to
7558 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7560 * Better dynamic linking support in SunOS
7562 Reading symbols from shared libraries which contain debugging symbols
7563 now works properly. However, there remain issues such as automatic
7564 skipping of `transfer vector' code during function calls, which
7565 make it harder to debug code in a shared library, than to debug the
7566 same code linked statically.
7570 GDB is now using the latest `getopt' routines from the FSF. This
7571 version accepts the -- prefix for options with long names. GDB will
7572 continue to accept the old forms (-option and +option) as well.
7573 Various single letter abbreviations for options have been explicity
7574 added to the option table so that they won't get overshadowed in the
7575 future by other options that begin with the same letter.
7579 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7580 Many assorted bugs have been handled. Many more remain to be handled.
7581 See the various ChangeLog files (primarily in gdb and bfd) for details.
7584 *** Changes in GDB-4.3:
7586 * New machines supported (host and target)
7588 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7589 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7590 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7592 * Almost SCO Unix support
7594 We had hoped to support:
7595 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7596 (except for core file support), but we discovered very late in the release
7597 that it has problems with process groups that render gdb unusable. Sorry
7598 about that. I encourage people to fix it and post the fixes.
7600 * Preliminary ELF and DWARF support
7602 GDB can read ELF object files on System V Release 4, and can handle
7603 debugging records for C, in DWARF format, in ELF files. This support
7604 is preliminary. If you bring up GDB on another SVR4 system, please
7605 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7610 GDB now uses the latest `readline' library. One user-visible change
7611 is that two tabs will list possible command completions, which previously
7612 required typing M-? (meta-question mark, or ESC ?).
7616 The `stepi' bug that many of you noticed has been squashed.
7617 Many bugs in C++ have been handled. Many more remain to be handled.
7618 See the various ChangeLog files (primarily in gdb and bfd) for details.
7620 * State of the MIPS world (in case you wondered):
7622 GDB can understand the symbol tables emitted by the compilers
7623 supplied by most vendors of MIPS-based machines, including DEC. These
7624 symbol tables are in a format that essentially nobody else uses.
7626 Some versions of gcc come with an assembler post-processor called
7627 mips-tfile. This program is required if you want to do source-level
7628 debugging of gcc-compiled programs. I believe FSF does not ship
7629 mips-tfile with gcc version 1, but it will eventually come with gcc
7632 Debugging of g++ output remains a problem. g++ version 1.xx does not
7633 really support it at all. (If you're lucky, you should be able to get
7634 line numbers and stack traces to work, but no parameters or local
7635 variables.) With some work it should be possible to improve the
7638 When gcc version 2 is released, you will have somewhat better luck.
7639 However, even then you will get confusing results for inheritance and
7642 We will eventually provide full debugging of g++ output on
7643 DECstations. This will probably involve some kind of stabs-in-ecoff
7644 encapulation, but the details have not been worked out yet.
7647 *** Changes in GDB-4.2:
7649 * Improved configuration
7651 Only one copy of `configure' exists now, and it is not self-modifying.
7652 Porting BFD is simpler.
7656 The `step' and `next' commands now only stop at the first instruction
7657 of a source line. This prevents the multiple stops that used to occur
7658 in switch statements, for-loops, etc. `Step' continues to stop if a
7659 function that has debugging information is called within the line.
7663 Lots of small bugs fixed. More remain.
7665 * New host supported (not target)
7667 Intel 386 PC clone running Mach i386-none-mach
7670 *** Changes in GDB-4.1:
7672 * Multiple source language support
7674 GDB now has internal scaffolding to handle several source languages.
7675 It determines the type of each source file from its filename extension,
7676 and will switch expression parsing and number formatting to match the
7677 language of the function in the currently selected stack frame.
7678 You can also specifically set the language to be used, with
7679 `set language c' or `set language modula-2'.
7683 GDB now has preliminary support for the GNU Modula-2 compiler,
7684 currently under development at the State University of New York at
7685 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7686 continue through the fall of 1991 and into 1992.
7688 Other Modula-2 compilers are currently not supported, and attempting to
7689 debug programs compiled with them will likely result in an error as the
7690 symbol table is read. Feel free to work on it, though!
7692 There are hooks in GDB for strict type checking and range checking,
7693 in the `Modula-2 philosophy', but they do not currently work.
7697 GDB can now write to executable and core files (e.g. patch
7698 a variable's value). You must turn this switch on, specify
7699 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7700 by assigning a new value to a variable. Modifications take
7703 * Automatic SunOS shared library reading
7705 When you run your program, GDB automatically determines where its
7706 shared libraries (if any) have been loaded, and reads their symbols.
7707 The `share' command is no longer needed. This also works when
7708 examining core files.
7712 You can specify the number of lines that the `list' command shows.
7715 * New machines supported (host and target)
7717 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7718 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7719 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7721 * New hosts supported (not targets)
7723 IBM RT/PC: romp-ibm-aix or rtpc
7725 * New targets supported (not hosts)
7727 AMD 29000 embedded with COFF a29k-none-coff
7728 AMD 29000 embedded with a.out a29k-none-aout
7729 Ultracomputer remote kernel debug a29k-nyu-kern
7731 * New remote interfaces
7737 *** Changes in GDB-4.0:
7741 Wide output is wrapped at good places to make the output more readable.
7743 Gdb now supports cross-debugging from a host machine of one type to a
7744 target machine of another type. Communication with the target system
7745 is over serial lines. The ``target'' command handles connecting to the
7746 remote system; the ``load'' command will download a program into the
7747 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7748 also supports debugging of realtime processes running under VxWorks,
7749 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7750 stub on the target system.
7752 New CPUs supported include the AMD 29000 and Intel 960.
7754 GDB now reads object files and symbol tables via a ``binary file''
7755 library, which allows a single copy of GDB to debug programs of multiple
7756 object file types such as a.out and coff.
7758 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7759 refcard.dvi and refcard.ps are available to format it).
7762 * Control-Variable user interface simplified
7764 All variables that control the operation of the debugger can be set
7765 by the ``set'' command, and displayed by the ``show'' command.
7767 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7768 ``Show prompt'' produces the response:
7769 Gdb's prompt is new-gdb=>.
7771 What follows are the NEW set commands. The command ``help set'' will
7772 print a complete list of old and new set commands. ``help set FOO''
7773 will give a longer description of the variable FOO. ``show'' will show
7774 all of the variable descriptions and their current settings.
7776 confirm on/off: Enables warning questions for operations that are
7777 hard to recover from, e.g. rerunning the program while
7778 it is already running. Default is ON.
7780 editing on/off: Enables EMACS style command line editing
7781 of input. Previous lines can be recalled with
7782 control-P, the current line can be edited with control-B,
7783 you can search for commands with control-R, etc.
7786 history filename NAME: NAME is where the gdb command history
7787 will be stored. The default is .gdb_history,
7788 or the value of the environment variable
7791 history size N: The size, in commands, of the command history. The
7792 default is 256, or the value of the environment variable
7795 history save on/off: If this value is set to ON, the history file will
7796 be saved after exiting gdb. If set to OFF, the
7797 file will not be saved. The default is OFF.
7799 history expansion on/off: If this value is set to ON, then csh-like
7800 history expansion will be performed on
7801 command line input. The default is OFF.
7803 radix N: Sets the default radix for input and output. It can be set
7804 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7805 in the current radix, so "set radix 10" is always a no-op.
7807 height N: This integer value is the number of lines on a page. Default
7808 is 24, the current `stty rows'' setting, or the ``li#''
7809 setting from the termcap entry matching the environment
7812 width N: This integer value is the number of characters on a line.
7813 Default is 80, the current `stty cols'' setting, or the ``co#''
7814 setting from the termcap entry matching the environment
7817 Note: ``set screensize'' is obsolete. Use ``set height'' and
7818 ``set width'' instead.
7820 print address on/off: Print memory addresses in various command displays,
7821 such as stack traces and structure values. Gdb looks
7822 more ``symbolic'' if you turn this off; it looks more
7823 ``machine level'' with it on. Default is ON.
7825 print array on/off: Prettyprint arrays. New convenient format! Default
7828 print demangle on/off: Print C++ symbols in "source" form if on,
7831 print asm-demangle on/off: Same, for assembler level printouts
7834 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7837 * Support for Epoch Environment.
7839 The epoch environment is a version of Emacs v18 with windowing. One
7840 new command, ``inspect'', is identical to ``print'', except that if you
7841 are running in the epoch environment, the value is printed in its own
7845 * Support for Shared Libraries
7847 GDB can now debug programs and core files that use SunOS shared libraries.
7848 Symbols from a shared library cannot be referenced
7849 before the shared library has been linked with the program (this
7850 happens after you type ``run'' and before the function main() is entered).
7851 At any time after this linking (including when examining core files
7852 from dynamically linked programs), gdb reads the symbols from each
7853 shared library when you type the ``sharedlibrary'' command.
7854 It can be abbreviated ``share''.
7856 sharedlibrary REGEXP: Load shared object library symbols for files
7857 matching a unix regular expression. No argument
7858 indicates to load symbols for all shared libraries.
7860 info sharedlibrary: Status of loaded shared libraries.
7865 A watchpoint stops execution of a program whenever the value of an
7866 expression changes. Checking for this slows down execution
7867 tremendously whenever you are in the scope of the expression, but is
7868 quite useful for catching tough ``bit-spreader'' or pointer misuse
7869 problems. Some machines such as the 386 have hardware for doing this
7870 more quickly, and future versions of gdb will use this hardware.
7872 watch EXP: Set a watchpoint (breakpoint) for an expression.
7874 info watchpoints: Information about your watchpoints.
7876 delete N: Deletes watchpoint number N (same as breakpoints).
7877 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7878 enable N: Re-enables watchpoint number N (same as breakpoints).
7881 * C++ multiple inheritance
7883 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7886 * C++ exception handling
7888 Gdb now supports limited C++ exception handling. Besides the existing
7889 ability to breakpoint on an exception handler, gdb can breakpoint on
7890 the raising of an exception (before the stack is peeled back to the
7893 catch FOO: If there is a FOO exception handler in the dynamic scope,
7894 set a breakpoint to catch exceptions which may be raised there.
7895 Multiple exceptions (``catch foo bar baz'') may be caught.
7897 info catch: Lists all exceptions which may be caught in the
7898 current stack frame.
7901 * Minor command changes
7903 The command ``call func (arg, arg, ...)'' now acts like the print
7904 command, except it does not print or save a value if the function's result
7905 is void. This is similar to dbx usage.
7907 The ``up'' and ``down'' commands now always print the frame they end up
7908 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7909 frames without printing.
7911 * New directory command
7913 'dir' now adds directories to the FRONT of the source search path.
7914 The path starts off empty. Source files that contain debug information
7915 about the directory in which they were compiled can be found even
7916 with an empty path; Sun CC and GCC include this information. If GDB can't
7917 find your source file in the current directory, type "dir .".
7919 * Configuring GDB for compilation
7921 For normal use, type ``./configure host''. See README or gdb.texinfo
7924 GDB now handles cross debugging. If you are remotely debugging between
7925 two different machines, type ``./configure host -target=targ''.
7926 Host is the machine where GDB will run; targ is the machine
7927 where the program that you are debugging will run.