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 * Debugging MS-Windows processes now sets $_exitsignal when the
33 inferior is terminated by a signal, instead of setting $_exitcode.
35 * Multithreaded symbol loading has now been enabled by default on systems
36 that support it (see entry for GDB 9, below), providing faster
37 performance for programs with many symbols.
39 * The $_siginfo convenience variable now also works on Windows targets,
40 and will display the EXCEPTION_RECORD of the last handled exception.
42 * TUI windows can now be arranged horizontally.
44 * The command history filename can now be set to the empty string
45 either using 'set history filename' or by setting 'GDBHISTFILE=' in
46 the environment. The effect of setting this filename to the empty
47 string is that GDB will not try to load any previous command
50 * On Windows targets, it is now possible to debug 32-bit programs with a
55 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
56 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
57 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
58 running process, this new option indicates whether to detect
59 a mismatch between the current executable file loaded by GDB and the
60 executable file used to start the process. If 'ask', the default,
61 display a warning and ask the user whether to load the process
62 executable file; if 'warn', just display a warning; if 'off', don't
63 attempt to detect a mismatch.
65 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
66 Define a new TUI layout, specifying its name and the windows that
71 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
75 ** gdb.register_window_type can be used to implement new TUI windows
78 ** Dynamic types can now be queried. gdb.Type has a new attribute,
79 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
80 field of a dynamic type may have None for its "bitpos" attribute
83 ** Commands written in Python can be in the "TUI" help class by
84 registering with the new constant gdb.COMMAND_TUI.
88 * 'thread-exited' event is now available in the annotations interface.
90 * New built-in convenience variables $_gdb_major and $_gdb_minor
91 provide the GDB version. They are handy for conditionally using
92 features available only in or since specific GDB versions, in
93 scripts that should work error-free with many different versions,
94 such as in system-wide init files.
96 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
97 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
98 of the GDB settings and the GDB maintenance settings. They are handy
99 for changing the logic of user defined commands depending on the
100 current GDB settings.
102 * GDB now supports Thread Local Storage (TLS) variables on several
103 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
104 architectures require kernel changes. TLS is not yet supported for
105 amd64 and i386 process core dumps.
107 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
108 addresses that required unmasking are shown in the backtrace with the
111 * Two new convenience functions $_cimag and $_creal that extract the
112 imaginary and real parts respectively from complex numbers.
114 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
115 provide the exitcode or exit status of the shell commands launched by
116 GDB commands such as "shell", "pipe" and "make".
118 * The command define-prefix can now define user defined prefix commands.
119 User defined commands can now be defined using these user defined prefix
122 * Command names can now use the . character.
124 * The RX port now supports XML target descriptions.
126 * GDB now shows the Ada task names at more places, e.g. in task switching
129 * GDB can now be compiled with Python 3 on Windows.
131 * New convenience variable $_ada_exception holds the address of the
132 Ada exception being thrown. This is set by Ada-related catchpoints.
134 * GDB can now place breakpoints on nested functions and subroutines in
135 Fortran code. The '::' operator can be used between parent and
136 child scopes when placing breakpoints, for example:
138 (gdb) break outer_function::inner_function
140 The 'outer_function::' prefix is only needed if 'inner_function' is
141 not visible in the current scope.
143 * In addition to the system-wide gdbinit file, if configured with
144 --with-system-gdbinit-dir, GDB will now also load files in that directory
145 as system gdbinit files, unless the -nx or -n flag is provided. Files
146 with extensions .gdb, .py and .scm are supported as long as GDB was
147 compiled with support for that language.
149 * GDB now supports multithreaded symbol loading for higher performance.
150 This feature is still in testing, so it is disabled by default. You
151 can turn it on using 'maint set worker-threads unlimited'.
153 * Multi-target debugging support
155 GDB now supports debugging multiple target connections
156 simultaneously. For example, you can now have each inferior
157 connected to different remote servers running in different machines,
158 or have one inferior debugging a local native process, an inferior
159 debugging a core dump, etc.
161 This support is experimental and comes with some limitations -- you
162 can only resume multiple targets simultaneously if all targets
163 support non-stop mode, and all remote stubs or servers must support
164 the same set of remote protocol features exactly. See also "info
165 connections" and "add-inferior -no-connection" below, and "maint set
166 target-non-stop" in the user manual.
170 ** The gdb.Value type has a new method 'format_string' which returns a
171 string representing the value. The formatting is controlled by the
172 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
173 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
174 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
176 ** gdb.Type has a new property 'objfile' which returns the objfile the
179 ** The frame information printed by the python frame filtering code
180 is now consistent with what the 'backtrace' command prints when
181 there are no filters, or when the 'backtrace' '-no-filters' option
184 ** The new function gdb.lookup_static_symbol can be used to look up
185 symbols with static linkage.
187 ** The new function gdb.lookup_static_symbols can be used to look up
188 all static symbols with static linkage.
190 ** gdb.Objfile has new methods 'lookup_global_symbol' and
191 'lookup_static_symbol' to lookup a symbol from this objfile only.
193 ** gdb.Block now supports the dictionary syntax for accessing symbols in
194 this block (e.g. block['local_variable']).
198 | [COMMAND] | SHELL_COMMAND
199 | -d DELIM COMMAND DELIM SHELL_COMMAND
200 pipe [COMMAND] | SHELL_COMMAND
201 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
202 Executes COMMAND and sends its output to SHELL_COMMAND.
203 With no COMMAND, repeat the last executed command
204 and send its output to SHELL_COMMAND.
206 define-prefix COMMAND
207 Define or mark a command as a user-defined prefix command.
209 with SETTING [VALUE] [-- COMMAND]
210 w SETTING [VALUE] [-- COMMAND]
211 Temporarily set SETTING, run COMMAND, and restore SETTING.
212 Usage: with SETTING -- COMMAND
213 With no COMMAND, repeats the last executed command.
214 SETTING is any GDB setting you can change with the "set"
215 subcommands. For example, 'with language c -- print someobj'
216 temporarily switches to the C language in order to print someobj.
217 Settings can be combined: 'w lang c -- w print elements unlimited --
218 usercmd' switches to the C language and runs usercmd with no limit
219 of array elements to print.
221 maint with SETTING [VALUE] [-- COMMAND]
222 Like "with", but works with "maintenance set" settings.
224 set may-call-functions [on|off]
225 show may-call-functions
226 This controls whether GDB will attempt to call functions in
227 the program, such as with expressions in the print command. It
228 defaults to on. Calling functions in the program being debugged
229 can have undesired side effects. It is now possible to forbid
230 such function calls. If function calls are forbidden, GDB will throw
231 an error when a command (such as print expression) calls a function
234 set print finish [on|off]
236 This controls whether the `finish' command will display the value
237 that is returned by the current function. When `off', the value is
238 still entered into the value history, but it is not printed. The
243 Allows deeply nested structures to be simplified when printing by
244 replacing deeply nested parts (beyond the max-depth) with ellipses.
245 The default max-depth is 20, but this can be set to unlimited to get
246 the old behavior back.
248 set print raw-values [on|off]
249 show print raw-values
250 By default, GDB applies the enabled pretty printers when printing a
251 value. This allows to ignore the enabled pretty printers for a series
252 of commands. The default is 'off'.
254 set logging debugredirect [on|off]
255 By default, GDB debug output will go to both the terminal and the logfile.
256 Set if you want debug output to go only to the log file.
258 set style title foreground COLOR
259 set style title background COLOR
260 set style title intensity VALUE
261 Control the styling of titles.
263 set style highlight foreground COLOR
264 set style highlight background COLOR
265 set style highlight intensity VALUE
266 Control the styling of highlightings.
268 maint set worker-threads
269 maint show worker-threads
270 Control the number of worker threads that can be used by GDB. The
271 default is 0. "unlimited" lets GDB choose a number that is
272 reasonable. Currently worker threads are only used when demangling
273 the names of linker symbols.
275 set style tui-border foreground COLOR
276 set style tui-border background COLOR
277 Control the styling of TUI borders.
279 set style tui-active-border foreground COLOR
280 set style tui-active-border background COLOR
281 Control the styling of the active TUI border.
283 maint set test-settings KIND
284 maint show test-settings KIND
285 A set of commands used by the testsuite for exercising the settings
288 maint set tui-resize-message [on|off]
289 maint show tui-resize-message
290 Control whether GDB prints a message each time the terminal is
291 resized when in TUI mode. This is primarily useful for testing the
294 set print frame-info [short-location|location|location-and-address
295 |source-and-location|source-line|auto]
296 show print frame-info
297 This controls what frame information is printed by the commands printing
298 a frame. This setting will e.g. influence the behaviour of 'backtrace',
299 'frame', 'stepi'. The python frame filtering also respect this setting.
300 The 'backtrace' '-frame-info' option can override this global setting.
302 set tui compact-source
303 show tui compact-source
305 Enable the "compact" display mode for the TUI source window. The
306 compact display uses only as much space as is needed for the line
307 numbers in the current file, and only a single space to separate the
308 line numbers from the source.
310 info modules [-q] [REGEXP]
311 Return a list of Fortran modules matching REGEXP, or all modules if
314 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
315 Return a list of functions within all modules, grouped by module.
316 The list of functions can be restricted with the optional regular
317 expressions. MODULE_REGEXP matches against the module name,
318 TYPE_REGEXP matches against the function type signature, and REGEXP
319 matches against the function name.
321 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
322 Return a list of variables within all modules, grouped by module.
323 The list of variables can be restricted with the optional regular
324 expressions. MODULE_REGEXP matches against the module name,
325 TYPE_REGEXP matches against the variable type, and REGEXP matches
326 against the variable name.
328 set debug remote-packet-max-chars
329 show debug remote-packet-max-chars
330 Controls the number of characters to output in a remote packet when using
332 The default is 512 bytes.
335 Lists the target connections currently in use.
340 The "help" command uses the title style to enhance the
341 readibility of its output by styling the classes and
345 Similarly to "help", the "apropos" command also uses the
346 title style for the command names. "apropos" accepts now
347 a flag "-v" (verbose) to show the full documentation
348 of matching commands and to use the highlight style to mark
349 the documentation parts matching REGEXP.
353 The GDB printf and eval commands can now print C-style and Ada-style
354 string convenience variables without calling functions in the program.
355 This allows to do formatted printing of strings without having
356 a running inferior, or when debugging a core dump.
358 info sources [-dirname | -basename] [--] [REGEXP]
359 This command has now optional arguments to only print the files
360 whose names match REGEXP. The arguments -dirname and -basename
361 allow to restrict matching respectively to the dirname and basename
365 The "show style" and its subcommands are now styling
366 a style name in their output using its own style, to help
367 the user visualize the different styles.
369 set print frame-arguments
370 The new value 'presence' indicates to only indicate the presence of
371 arguments using ..., instead of printing argument names and values.
373 set print raw-frame-arguments
374 show print raw-frame-arguments
376 These commands replace the similarly-named "set/show print raw
377 frame-arguments" commands (now with a dash instead of a space). The
378 old commands are now deprecated and may be removed in a future
381 add-inferior [-no-connection]
382 The add-inferior command now supports a "-no-connection" flag that
383 makes the new inferior start with no target connection associated.
384 By default, the new inferior inherits the target connection of the
385 current inferior. See also "info connections".
388 This command's output now includes a new "Connection" column
389 indicating which target connection an inferior is bound to. See
390 "info connections" above.
392 maint test-options require-delimiter
393 maint test-options unknown-is-error
394 maint test-options unknown-is-operand
395 maint show test-options-completion-result
396 Commands used by the testsuite to validate the command options
399 focus, winheight, +, -, >, <
400 These commands are now case-sensitive.
402 * New command options, command completion
404 GDB now has a standard infrastructure to support dash-style command
405 options ('-OPT'). One benefit is that commands that use it can
406 easily support completion of command line arguments. Try "CMD
407 -[TAB]" or "help CMD" to find options supported by a command. Over
408 time, we intend to migrate most commands to this infrastructure. A
409 number of commands got support for new command options in this
412 ** The "print" and "compile print" commands now support a number of
413 options that allow overriding relevant global print settings as
414 set by "set print" subcommands:
418 -array-indexes [on|off]
419 -elements NUMBER|unlimited
424 -repeats NUMBER|unlimited
425 -static-members [on|off]
430 Note that because the "print"/"compile print" commands accept
431 arbitrary expressions which may look like options (including
432 abbreviations), if you specify any command option, then you must
433 use a double dash ("--") to mark the end of argument processing.
435 ** The "backtrace" command now supports a number of options that
436 allow overriding relevant global print settings as set by "set
437 backtrace" and "set print" subcommands:
439 -entry-values no|only|preferred|if-needed|both|compact|default
440 -frame-arguments all|scalars|none
441 -raw-frame-arguments [on|off]
442 -frame-info auto|source-line|location|source-and-location
443 |location-and-address|short-location
447 In addition, the full/no-filters/hide qualifiers are now also
448 exposed as command options too:
454 ** The "frame apply", "tfaas" and "faas" commands similarly now
455 support the following options:
460 ** The new "info sources" options -dirname and -basename options
461 are using the standard '-OPT' infrastructure.
463 All options above can also be abbreviated. The argument of boolean
464 (on/off) options can be 0/1 too, and also the argument is assumed
465 "on" if omitted. This allows writing compact command invocations,
468 (gdb) p -ra -p -o 0 -- *myptr
470 The above is equivalent to:
472 (gdb) print -raw-values -pretty -object off -- *myptr
474 ** The "info types" command now supports the '-q' flag to disable
475 printing of some header information in a similar fashion to "info
476 variables" and "info functions".
478 ** The "info variables", "info functions", and "whereis" commands
479 now take a '-n' flag that excludes non-debug symbols (symbols
480 from the symbol table, not from the debug info such as DWARF)
483 * Completion improvements
485 ** GDB can now complete the options of the "thread apply all" and
486 "taas" commands, and their "-ascending" option can now be
489 ** GDB can now complete the options of the "info threads", "info
490 functions", "info variables", "info locals", and "info args"
493 ** GDB can now complete the options of the "compile file" and
494 "compile code" commands. The "compile file" command now
495 completes on filenames.
497 ** GDB can now complete the backtrace command's
498 "full/no-filters/hide" qualifiers.
500 * In settings, you can now abbreviate "unlimited".
502 E.g., "set print elements u" is now equivalent to "set print
508 This lists all the possible completions for the rest of the line, if it
509 were to be given as a command itself. This is intended for use by MI
510 frontends in cases when separate CLI and MI channels cannot be used.
512 -catch-throw, -catch-rethrow, and -catch-catch
513 These can be used to catch C++ exceptions in a similar fashion to
514 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
516 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
517 These commands are the MI equivalent of the CLI commands 'info
518 functions', 'info types', and 'info variables' respectively.
520 -symbol-info-modules, this is the MI equivalent of the CLI 'info
523 -symbol-info-module-functions and -symbol-info-module-variables.
524 These commands are the MI equivalent of the CLI commands 'info
525 module functions' and 'info module variables'.
529 ** The default version of the MI interpreter is now 3 (-i=mi3).
531 ** The output of information about multi-location breakpoints (which is
532 syntactically incorrect in MI 2) has changed in MI 3. This affects
533 the following commands and events:
537 - =breakpoint-created
538 - =breakpoint-modified
540 The -fix-multi-location-breakpoint-output command can be used to enable
541 this behavior with previous MI versions.
543 ** Backtraces and frames include a new optional field addr_flags which is
544 given after the addr field. On AArch64 this contains PAC if the address
545 has been masked in the frame. On all other targets the field is not
550 The testsuite now creates the files gdb.cmd (containing the arguments
551 used to launch GDB) and gdb.in (containing all the commands sent to
552 GDB) in the output directory for each test script. Multiple invocations
553 are appended with .1, .2, .3 etc.
555 * Building GDB and GDBserver now requires GNU make >= 3.82.
557 Using another implementation of the make program or an earlier version of
558 GNU make to build GDB or GDBserver is not supported.
560 * Building GDB now requires GNU readline >= 7.0.
562 GDB now bundles GNU readline 8.0, but if you choose to use
563 --with-system-readline, only readline >= 7.0 can be used.
565 * The TUI SingleKey keymap is now named "SingleKey". This can be used
566 from .inputrc to bind keys in this keymap. This feature is only
567 available when gdb is built against GNU readline 8.0 or later.
569 * Removed targets and native configurations
571 GDB no longer supports debugging the Cell Broadband Engine. This includes
572 both debugging standalone Cell/B.E. SPU applications and integrated debugging
573 of Cell/B.E. applications that use both the PPU and SPU architectures.
579 * Removed targets and native configurations
581 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
584 *** Changes in GDB 8.3
586 * GDB and GDBserver now support access to additional registers on
587 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
590 * GDB now has experimental support for the compilation and injection of
591 C++ source code into the inferior. This beta release does not include
592 support for several language features, such as templates, constructors,
595 This feature requires GCC 7.1 or higher built with libcp1.so
598 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
599 can be passed using the '[ADDRESS]:PORT' notation, or the regular
600 'ADDRESS:PORT' method.
602 * DWARF index cache: GDB can now automatically save indices of DWARF
603 symbols on disk to speed up further loading of the same binaries.
605 * Ada task switching is now supported on aarch64-elf targets when
606 debugging a program using the Ravenscar Profile. For more information,
607 see the "Tasking Support when using the Ravenscar Profile" section
608 in the GDB user manual.
610 * GDB in batch mode now exits with status 1 if the last command to be
613 * The RISC-V target now supports target descriptions.
615 * System call catchpoints now support system call aliases on FreeBSD.
616 When the ABI of a system call changes in FreeBSD, this is
617 implemented by leaving a compatibility system call using the old ABI
618 at the existing number and allocating a new system call number for
619 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
620 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
621 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
622 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
623 so that a system call catchpoint for the 'kevent' system call will
624 catch invocations of both the 'kevent' and 'freebsd11_kevent'
625 binaries. This ensures that 'kevent' system calls are caught for
626 binaries using either the old or new ABIs.
628 * Terminal styling is now available for the CLI and the TUI. GNU
629 Source Highlight can additionally be used to provide styling of
630 source code snippets. See the "set style" commands, below, for more
633 * Removed support for old demangling styles arm, edg, gnu, hp and
638 set debug compile-cplus-types
639 show debug compile-cplus-types
640 Control the display of debug output about type conversion in the
641 C++ compile feature. Commands have no effect while compiliong
646 Control whether debug output about files/functions skipping is
649 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
650 Apply a command to some frames.
651 FLAG arguments allow to control what output to produce and how to handle
652 errors raised when applying COMMAND to a frame.
655 Apply a command to all threads (ignoring errors and empty output).
656 Shortcut for 'thread apply all -s COMMAND'.
659 Apply a command to all frames (ignoring errors and empty output).
660 Shortcut for 'frame apply all -s COMMAND'.
663 Apply a command to all frames of all threads (ignoring errors and empty
665 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
667 maint set dwarf unwinders (on|off)
668 maint show dwarf unwinders
669 Control whether DWARF unwinders can be used.
672 Display a list of open files for a process.
676 Changes to the "frame", "select-frame", and "info frame" CLI commands.
677 These commands all now take a frame specification which
678 is either a frame level, or one of the keywords 'level', 'address',
679 'function', or 'view' followed by a parameter. Selecting a frame by
680 address, or viewing a frame outside the current backtrace now
681 requires the use of a keyword. Selecting a frame by level is
682 unchanged. The MI comment "-stack-select-frame" is unchanged.
684 target remote FILENAME
685 target extended-remote FILENAME
686 If FILENAME is a Unix domain socket, GDB will attempt to connect
687 to this socket instead of opening FILENAME as a character device.
689 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
690 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
691 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
692 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
693 These commands can now print only the searched entities
694 matching the provided regexp(s), giving a condition
695 on the entity names or entity types. The flag -q disables
696 printing headers or informations messages.
702 These commands now determine the syntax for the shown entities
703 according to the language chosen by `set language'. In particular,
704 `set language auto' means to automatically choose the language of
707 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
708 The 'thread apply' command accepts new FLAG arguments.
709 FLAG arguments allow to control what output to produce and how to handle
710 errors raised when applying COMMAND to a thread.
712 set tui tab-width NCHARS
713 show tui tab-width NCHARS
714 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
716 set style enabled [on|off]
718 Enable or disable terminal styling. Styling is enabled by default
719 on most hosts, but disabled by default when in batch mode.
721 set style sources [on|off]
723 Enable or disable source code styling. Source code styling is
724 enabled by default, but only takes effect if styling in general is
725 enabled, and if GDB was linked with GNU Source Highlight.
727 set style filename foreground COLOR
728 set style filename background COLOR
729 set style filename intensity VALUE
730 Control the styling of file names.
732 set style function foreground COLOR
733 set style function background COLOR
734 set style function intensity VALUE
735 Control the styling of function names.
737 set style variable foreground COLOR
738 set style variable background COLOR
739 set style variable intensity VALUE
740 Control the styling of variable names.
742 set style address foreground COLOR
743 set style address background COLOR
744 set style address intensity VALUE
745 Control the styling of addresses.
749 ** The '-data-disassemble' MI command now accepts an '-a' option to
750 disassemble the whole function surrounding the given program
751 counter value or function name. Support for this feature can be
752 verified by using the "-list-features" command, which should
753 contain "data-disassemble-a-option".
755 ** Command responses and notifications that include a frame now include
756 the frame's architecture in a new "arch" attribute.
758 * New native configurations
760 GNU/Linux/RISC-V riscv*-*-linux*
761 FreeBSD/riscv riscv*-*-freebsd*
765 GNU/Linux/RISC-V riscv*-*-linux*
767 CSKY GNU/LINUX csky*-*-linux
768 FreeBSD/riscv riscv*-*-freebsd*
770 GNU/Linux/OpenRISC or1k*-*-linux*
774 GDB no longer supports native debugging on versions of MS-Windows
779 ** GDB no longer supports Python versions less than 2.6.
781 ** The gdb.Inferior type has a new 'progspace' property, which is the program
782 space associated to that inferior.
784 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
785 of objfiles associated to that program space.
787 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
788 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
791 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
792 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
793 correct and did not work properly.
795 ** The gdb.Value type has a new constructor, which is used to construct a
796 gdb.Value from a Python buffer object and a gdb.Type.
802 Enable or disable the undefined behavior sanitizer. This is
803 disabled by default, but passing --enable-ubsan=yes or
804 --enable-ubsan=auto to configure will enable it. Enabling this can
805 cause a performance penalty. The undefined behavior sanitizer was
806 first introduced in GCC 4.9.
808 *** Changes in GDB 8.2
810 * The 'set disassembler-options' command now supports specifying options
813 * The 'symbol-file' command now accepts an '-o' option to add a relative
814 offset to all sections.
816 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
817 a relative offset to all sections, but it allows to override the load
818 address of individual sections using '-s'.
820 * The 'add-symbol-file' command no longer requires the second argument
821 (address of the text section).
823 * The endianness used with the 'set endian auto' mode in the absence of
824 an executable selected for debugging is now the last endianness chosen
825 either by one of the 'set endian big' and 'set endian little' commands
826 or by inferring from the last executable used, rather than the startup
829 * The pager now allows a "c" response, meaning to disable the pager
830 for the rest of the current command.
832 * The commands 'info variables/functions/types' now show the source line
833 numbers of symbol definitions when available.
835 * 'info proc' now works on running processes on FreeBSD systems and core
836 files created on FreeBSD systems.
838 * C expressions can now use _Alignof, and C++ expressions can now use
841 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
842 the vector length while the process is running.
848 Control display of debugging info regarding the FreeBSD native target.
850 set|show varsize-limit
851 This new setting allows the user to control the maximum size of Ada
852 objects being printed when those objects have a variable type,
853 instead of that maximum size being hardcoded to 65536 bytes.
855 set|show record btrace cpu
856 Controls the processor to be used for enabling errata workarounds for
859 maint check libthread-db
860 Run integrity checks on the current inferior's thread debugging
863 maint set check-libthread-db (on|off)
864 maint show check-libthread-db
865 Control whether to run integrity checks on inferior specific thread
866 debugging libraries as they are loaded. The default is not to
871 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
873 ** The commands attached to a breakpoint can be set by assigning to
874 the breakpoint's "commands" field.
876 ** gdb.execute can now execute multi-line gdb commands.
878 ** The new functions gdb.convenience_variable and
879 gdb.set_convenience_variable can be used to get and set the value
880 of convenience variables.
882 ** A gdb.Parameter will no longer print the "set" help text on an
883 ordinary "set"; instead by default a "set" will be silent unless
884 the get_set_string method returns a non-empty string.
888 RiscV ELF riscv*-*-elf
890 * Removed targets and native configurations
892 m88k running OpenBSD m88*-*-openbsd*
893 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
894 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
895 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
897 * Aarch64/Linux hardware watchpoints improvements
899 Hardware watchpoints on unaligned addresses are now properly
900 supported when running Linux kernel 4.10 or higher: read and access
901 watchpoints are no longer spuriously missed, and all watchpoints
902 lengths between 1 and 8 bytes are supported. On older kernels,
903 watchpoints set on unaligned addresses are no longer missed, with
904 the tradeoff that there is a possibility of false hits being
909 --enable-codesign=CERT
910 This can be used to invoke "codesign -s CERT" after building gdb.
911 This option is useful on macOS, where code signing is required for
912 gdb to work properly.
914 --disable-gdbcli has been removed
915 This is now silently accepted, but does nothing.
917 *** Changes in GDB 8.1
919 * GDB now supports dynamically creating arbitrary register groups specified
920 in XML target descriptions. This allows for finer grain grouping of
921 registers on systems with a large amount of registers.
923 * The 'ptype' command now accepts a '/o' flag, which prints the
924 offsets and sizes of fields in a struct, like the pahole(1) tool.
926 * New "--readnever" command line option instructs GDB to not read each
927 symbol file's symbolic debug information. This makes startup faster
928 but at the expense of not being able to perform symbolic debugging.
929 This option is intended for use cases where symbolic debugging will
930 not be used, e.g., when you only need to dump the debuggee's core.
932 * GDB now uses the GNU MPFR library, if available, to emulate target
933 floating-point arithmetic during expression evaluation when the target
934 uses different floating-point formats than the host. At least version
935 3.1 of GNU MPFR is required.
937 * GDB now supports access to the guarded-storage-control registers and the
938 software-based guarded-storage broadcast control registers on IBM z14.
940 * On Unix systems, GDB now supports transmitting environment variables
941 that are to be set or unset to GDBserver. These variables will
942 affect the environment to be passed to the remote inferior.
944 To inform GDB of environment variables that are to be transmitted to
945 GDBserver, use the "set environment" command. Only user set
946 environment variables are sent to GDBserver.
948 To inform GDB of environment variables that are to be unset before
949 the remote inferior is started by the GDBserver, use the "unset
950 environment" command.
952 * Completion improvements
954 ** GDB can now complete function parameters in linespecs and
955 explicit locations without quoting. When setting breakpoints,
956 quoting around functions names to help with TAB-completion is
957 generally no longer necessary. For example, this now completes
960 (gdb) b function(in[TAB]
961 (gdb) b function(int)
963 Related, GDB is no longer confused with completing functions in
964 C++ anonymous namespaces:
967 (gdb) b (anonymous namespace)::[TAB][TAB]
968 (anonymous namespace)::a_function()
969 (anonymous namespace)::b_function()
971 ** GDB now has much improved linespec and explicit locations TAB
972 completion support, that better understands what you're
973 completing and offers better suggestions. For example, GDB no
974 longer offers data symbols as possible completions when you're
975 setting a breakpoint.
977 ** GDB now TAB-completes label symbol names.
979 ** The "complete" command now mimics TAB completion accurately.
981 * New command line options (gcore)
984 Dump all memory mappings.
986 * Breakpoints on C++ functions are now set on all scopes by default
988 By default, breakpoints on functions/methods are now interpreted as
989 specifying all functions with the given name ignoring missing
990 leading scopes (namespaces and classes).
992 For example, assuming a C++ program with symbols named:
997 both commands "break func()" and "break B::func()" set a breakpoint
1000 You can use the new flag "-qualified" to override this. This makes
1001 GDB interpret the specified function name as a complete
1002 fully-qualified name instead. For example, using the same C++
1003 program, the "break -q B::func" command sets a breakpoint on
1004 "B::func", only. A parameter has been added to the Python
1005 gdb.Breakpoint constructor to achieve the same result when creating
1006 a breakpoint from Python.
1008 * Breakpoints on functions marked with C++ ABI tags
1010 GDB can now set breakpoints on functions marked with C++ ABI tags
1011 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1012 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1014 Functions with a C++11 abi tag are demangled/displayed like this:
1016 function[abi:cxx11](int)
1019 You can now set a breakpoint on such functions simply as if they had
1022 (gdb) b function(int)
1024 Or if you need to disambiguate between tags, like:
1026 (gdb) b function[abi:other_tag](int)
1028 Tab completion was adjusted accordingly as well.
1032 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1033 gdb.new_thread are emitted. See the manual for further
1034 description of these.
1036 ** A new function, "gdb.rbreak" has been added to the Python API.
1037 This function allows the setting of a large number of breakpoints
1038 via a regex pattern in Python. See the manual for further details.
1040 ** Python breakpoints can now accept explicit locations. See the
1041 manual for a further description of this feature.
1044 * New features in the GDB remote stub, GDBserver
1046 ** GDBserver is now able to start inferior processes with a
1047 specified initial working directory.
1049 The user can set the desired working directory to be used from
1050 GDB using the new "set cwd" command.
1052 ** New "--selftest" command line option runs some GDBserver self
1053 tests. These self tests are disabled in releases.
1055 ** On Unix systems, GDBserver now does globbing expansion and variable
1056 substitution in inferior command line arguments.
1058 This is done by starting inferiors using a shell, like GDB does.
1059 See "set startup-with-shell" in the user manual for how to disable
1060 this from GDB when using "target extended-remote". When using
1061 "target remote", you can disable the startup with shell by using the
1062 new "--no-startup-with-shell" GDBserver command line option.
1064 ** On Unix systems, GDBserver now supports receiving environment
1065 variables that are to be set or unset from GDB. These variables
1066 will affect the environment to be passed to the inferior.
1068 * When catching an Ada exception raised with a message, GDB now prints
1069 the message in the catchpoint hit notification. In GDB/MI mode, that
1070 information is provided as an extra field named "exception-message"
1071 in the *stopped notification.
1073 * Trait objects can now be inspected When debugging Rust code. This
1074 requires compiler support which will appear in Rust 1.24.
1076 * New remote packets
1078 QEnvironmentHexEncoded
1079 Inform GDBserver of an environment variable that is to be passed to
1080 the inferior when starting it.
1083 Inform GDBserver of an environment variable that is to be unset
1084 before starting the remote inferior.
1087 Inform GDBserver that the environment should be reset (i.e.,
1088 user-set environment variables should be unset).
1091 Indicates whether the inferior must be started with a shell or not.
1094 Tell GDBserver that the inferior to be started should use a specific
1097 * The "maintenance print c-tdesc" command now takes an optional
1098 argument which is the file name of XML target description.
1100 * The "maintenance selftest" command now takes an optional argument to
1101 filter the tests to be run.
1103 * The "enable", and "disable" commands now accept a range of
1104 breakpoint locations, e.g. "enable 1.3-5".
1109 Set and show the current working directory for the inferior.
1111 set|show compile-gcc
1112 Set and show compilation command used for compiling and injecting code
1113 with the 'compile' commands.
1115 set debug separate-debug-file
1116 show debug separate-debug-file
1117 Control the display of debug output about separate debug file search.
1119 set dump-excluded-mappings
1120 show dump-excluded-mappings
1121 Control whether mappings marked with the VM_DONTDUMP flag should be
1122 dumped when generating a core file.
1124 maint info selftests
1125 List the registered selftests.
1128 Start the debugged program stopping at the first instruction.
1131 Control display of debugging messages related to OpenRISC targets.
1133 set|show print type nested-type-limit
1134 Set and show the limit of nesting level for nested types that the
1135 type printer will show.
1137 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1140 * Safer/improved support for debugging with no debug info
1142 GDB no longer assumes functions with no debug information return
1145 This means that GDB now refuses to call such functions unless you
1146 tell it the function's type, by either casting the call to the
1147 declared return type, or by casting the function to a function
1148 pointer of the right type, and calling that:
1150 (gdb) p getenv ("PATH")
1151 'getenv' has unknown return type; cast the call to its declared return type
1152 (gdb) p (char *) getenv ("PATH")
1153 $1 = 0x7fffffffe "/usr/local/bin:/"...
1154 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1155 $2 = 0x7fffffffe "/usr/local/bin:/"...
1157 Similarly, GDB no longer assumes that global variables with no debug
1158 info have type 'int', and refuses to print the variable's value
1159 unless you tell it the variable's type:
1162 'var' has unknown type; cast it to its declared type
1166 * New native configurations
1168 FreeBSD/aarch64 aarch64*-*-freebsd*
1169 FreeBSD/arm arm*-*-freebsd*
1173 FreeBSD/aarch64 aarch64*-*-freebsd*
1174 FreeBSD/arm arm*-*-freebsd*
1175 OpenRISC ELF or1k*-*-elf
1177 * Removed targets and native configurations
1179 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1181 *** Changes in GDB 8.0
1183 * GDB now supports access to the PKU register on GNU/Linux. The register is
1184 added by the Memory Protection Keys for Userspace feature which will be
1185 available in future Intel CPUs.
1187 * GDB now supports C++11 rvalue references.
1191 ** New functions to start, stop and access a running btrace recording.
1192 ** Rvalue references are now supported in gdb.Type.
1194 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1197 * Building GDB and GDBserver now requires a C++11 compiler.
1199 For example, GCC 4.8 or later.
1201 It is no longer possible to build GDB or GDBserver with a C
1202 compiler. The --disable-build-with-cxx configure option has been
1205 * Building GDB and GDBserver now requires GNU make >= 3.81.
1207 It is no longer supported to build GDB or GDBserver with another
1208 implementation of the make program or an earlier version of GNU make.
1210 * Native debugging on MS-Windows supports command-line redirection
1212 Command-line arguments used for starting programs on MS-Windows can
1213 now include redirection symbols supported by native Windows shells,
1214 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1215 as "run", "start", and "set args", as well as the corresponding MI
1218 * Support for thread names on MS-Windows.
1220 GDB now catches and handles the special exception that programs
1221 running on MS-Windows use to assign names to threads in the
1224 * Support for Java programs compiled with gcj has been removed.
1226 * User commands now accept an unlimited number of arguments.
1227 Previously, only up to 10 was accepted.
1229 * The "eval" command now expands user-defined command arguments.
1231 This makes it easier to process a variable number of arguments:
1236 eval "print $arg%d", $i
1241 * Target descriptions can now describe registers for sparc32 and sparc64.
1243 * GDB now supports DWARF version 5 (debug information format).
1244 Its .debug_names index is not yet supported.
1246 * New native configurations
1248 FreeBSD/mips mips*-*-freebsd
1252 Synopsys ARC arc*-*-elf32
1253 FreeBSD/mips mips*-*-freebsd
1255 * Removed targets and native configurations
1257 Alpha running FreeBSD alpha*-*-freebsd*
1258 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1263 Erases all the flash memory regions reported by the target.
1265 maint print arc arc-instruction address
1266 Print internal disassembler information about instruction at a given address.
1270 set disassembler-options
1271 show disassembler-options
1272 Controls the passing of target specific information to the disassembler.
1273 If it is necessary to specify more than one disassembler option then
1274 multiple options can be placed together into a comma separated list.
1275 The default value is the empty string. Currently, the only supported
1276 targets are ARM, PowerPC and S/390.
1281 Erases all the flash memory regions reported by the target. This is
1282 equivalent to the CLI command flash-erase.
1284 -file-list-shared-libraries
1285 List the shared libraries in the program. This is
1286 equivalent to the CLI command "info shared".
1289 Catchpoints stopping the program when Ada exceptions are
1290 handled. This is equivalent to the CLI command "catch handlers".
1292 *** Changes in GDB 7.12
1294 * GDB and GDBserver now build with a C++ compiler by default.
1296 The --enable-build-with-cxx configure option is now enabled by
1297 default. One must now explicitly configure with
1298 --disable-build-with-cxx in order to build with a C compiler. This
1299 option will be removed in a future release.
1301 * GDBserver now supports recording btrace without maintaining an active
1304 * GDB now supports a negative repeat count in the 'x' command to examine
1305 memory backward from the given address. For example:
1308 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1309 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1310 (gdb) x/-5i 0x0000000000400580
1311 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1312 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1313 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1314 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1315 0x40057b <main(int, char**)+25>:
1316 callq 0x400536 <Func1(int, char const*)>
1318 * Fortran: Support structures with fields of dynamic types and
1319 arrays of dynamic types.
1321 * The symbol dumping maintenance commands have new syntax.
1322 maint print symbols [-pc address] [--] [filename]
1323 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1324 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1325 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1326 maint print msymbols [-objfile objfile] [--] [filename]
1328 * GDB now supports multibit bitfields and enums in target register
1331 * New Python-based convenience function $_as_string(val), which returns
1332 the textual representation of a value. This function is especially
1333 useful to obtain the text label of an enum value.
1335 * Intel MPX bound violation handling.
1337 Segmentation faults caused by a Intel MPX boundary violation
1338 now display the kind of violation (upper or lower), the memory
1339 address accessed and the memory bounds, along with the usual
1340 signal received and code location.
1344 Program received signal SIGSEGV, Segmentation fault
1345 Upper bound violation while accessing address 0x7fffffffc3b3
1346 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1347 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1349 * Rust language support.
1350 GDB now supports debugging programs written in the Rust programming
1351 language. See https://www.rust-lang.org/ for more information about
1354 * Support for running interpreters on specified input/output devices
1356 GDB now supports a new mechanism that allows frontends to provide
1357 fully featured GDB console views, as a better alternative to
1358 building such views on top of the "-interpreter-exec console"
1359 command. See the new "new-ui" command below. With that command,
1360 frontends can now start GDB in the traditional command-line mode
1361 running in an embedded terminal emulator widget, and create a
1362 separate MI interpreter running on a specified i/o device. In this
1363 way, GDB handles line editing, history, tab completion, etc. in the
1364 console all by itself, and the GUI uses the separate MI interpreter
1365 for its own control and synchronization, invisible to the command
1368 * The "catch syscall" command catches groups of related syscalls.
1370 The "catch syscall" command now supports catching a group of related
1371 syscalls using the 'group:' or 'g:' prefix.
1376 skip -gfile file-glob-pattern
1377 skip -function function
1378 skip -rfunction regular-expression
1379 A generalized form of the skip command, with new support for
1380 glob-style file names and regular expressions for function names.
1381 Additionally, a file spec and a function spec may now be combined.
1383 maint info line-table REGEXP
1384 Display the contents of GDB's internal line table data struture.
1387 Run any GDB unit tests that were compiled in.
1390 Start a new user interface instance running INTERP as interpreter,
1391 using the TTY file for input/output.
1395 ** gdb.Breakpoint objects have a new attribute "pending", which
1396 indicates whether the breakpoint is pending.
1397 ** Three new breakpoint-related events have been added:
1398 gdb.breakpoint_created, gdb.breakpoint_modified, and
1399 gdb.breakpoint_deleted.
1401 signal-event EVENTID
1402 Signal ("set") the given MS-Windows event object. This is used in
1403 conjunction with the Windows JIT debugging (AeDebug) support, where
1404 the OS suspends a crashing process until a debugger can attach to
1405 it. Resuming the crashing process, in order to debug it, is done by
1406 signalling an event.
1408 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1409 was added in GDBserver, including JIT compiling fast tracepoint's
1410 conditional expression bytecode into native code.
1412 * Support for various remote target protocols and ROM monitors has
1415 target m32rsdi Remote M32R debugging over SDI
1416 target mips MIPS remote debugging protocol
1417 target pmon PMON ROM monitor
1418 target ddb NEC's DDB variant of PMON for Vr4300
1419 target rockhopper NEC RockHopper variant of PMON
1420 target lsi LSI variant of PMO
1422 * Support for tracepoints and fast tracepoints on powerpc-linux,
1423 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1424 including JIT compiling fast tracepoint's conditional expression
1425 bytecode into native code.
1427 * MI async record =record-started now includes the method and format used for
1428 recording. For example:
1430 =record-started,thread-group="i1",method="btrace",format="bts"
1432 * MI async record =thread-selected now includes the frame field. For example:
1434 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1438 Andes NDS32 nds32*-*-elf
1440 *** Changes in GDB 7.11
1442 * GDB now supports debugging kernel-based threads on FreeBSD.
1444 * Per-inferior thread numbers
1446 Thread numbers are now per inferior instead of global. If you're
1447 debugging multiple inferiors, GDB displays thread IDs using a
1448 qualified INF_NUM.THR_NUM form. For example:
1452 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1453 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1454 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1455 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1457 As consequence, thread numbers as visible in the $_thread
1458 convenience variable and in Python's InferiorThread.num attribute
1459 are no longer unique between inferiors.
1461 GDB now maintains a second thread ID per thread, referred to as the
1462 global thread ID, which is the new equivalent of thread numbers in
1463 previous releases. See also $_gthread below.
1465 For backwards compatibility, MI's thread IDs always refer to global
1468 * Commands that accept thread IDs now accept the qualified
1469 INF_NUM.THR_NUM form as well. For example:
1472 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1475 * In commands that accept a list of thread IDs, you can now refer to
1476 all threads of an inferior using a star wildcard. GDB accepts
1477 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1478 refer to all threads of the current inferior. For example, "info
1481 * You can use "info threads -gid" to display the global thread ID of
1484 * The new convenience variable $_gthread holds the global number of
1487 * The new convenience variable $_inferior holds the number of the
1490 * GDB now displays the ID and name of the thread that hit a breakpoint
1491 or received a signal, if your program is multi-threaded. For
1494 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1495 Thread 1 "main" received signal SIGINT, Interrupt.
1497 * Record btrace now supports non-stop mode.
1499 * Support for tracepoints on aarch64-linux was added in GDBserver.
1501 * The 'record instruction-history' command now indicates speculative execution
1502 when using the Intel Processor Trace recording format.
1504 * GDB now allows users to specify explicit locations, bypassing
1505 the linespec parser. This feature is also available to GDB/MI
1508 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1509 GDB now is able to debug both AArch64 applications and ARM applications
1512 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1513 including JIT compiling fast tracepoint's conditional expression bytecode
1516 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1518 * "info threads", "info inferiors", "info display", "info checkpoints"
1519 and "maint info program-spaces" now list the corresponding items in
1520 ascending ID order, for consistency with all other "info" commands.
1522 * In Ada, the overloads selection menu has been enhanced to display the
1523 parameter types and the return types for the matching overloaded subprograms.
1527 maint set target-non-stop (on|off|auto)
1528 maint show target-non-stop
1529 Control whether GDB targets always operate in non-stop mode even if
1530 "set non-stop" is "off". The default is "auto", meaning non-stop
1531 mode is enabled if supported by the target.
1533 maint set bfd-sharing
1534 maint show bfd-sharing
1535 Control the reuse of bfd objects.
1538 show debug bfd-cache
1539 Control display of debugging info regarding bfd caching.
1543 Control display of debugging info regarding FreeBSD threads.
1545 set remote multiprocess-extensions-packet
1546 show remote multiprocess-extensions-packet
1547 Set/show the use of the remote protocol multiprocess extensions.
1549 set remote thread-events
1550 show remote thread-events
1551 Set/show the use of thread create/exit events.
1553 set ada print-signatures on|off
1554 show ada print-signatures"
1555 Control whether parameter types and return types are displayed in overloads
1556 selection menus. It is activaled (@code{on}) by default.
1560 Controls the maximum size of memory, in bytes, that GDB will
1561 allocate for value contents. Prevents incorrect programs from
1562 causing GDB to allocate overly large buffers. Default is 64k.
1564 * The "disassemble" command accepts a new modifier: /s.
1565 It prints mixed source+disassembly like /m with two differences:
1566 - disassembled instructions are now printed in program order, and
1567 - and source for all relevant files is now printed.
1568 The "/m" option is now considered deprecated: its "source-centric"
1569 output hasn't proved useful in practice.
1571 * The "record instruction-history" command accepts a new modifier: /s.
1572 It behaves exactly like /m and prints mixed source+disassembly.
1574 * The "set scheduler-locking" command supports a new mode "replay".
1575 It behaves like "off" in record mode and like "on" in replay mode.
1577 * Support for various ROM monitors has been removed:
1579 target dbug dBUG ROM monitor for Motorola ColdFire
1580 target picobug Motorola picobug monitor
1581 target dink32 DINK32 ROM monitor for PowerPC
1582 target m32r Renesas M32R/D ROM monitor
1583 target mon2000 mon2000 ROM monitor
1584 target ppcbug PPCBUG ROM monitor for PowerPC
1586 * Support for reading/writing memory and extracting values on architectures
1587 whose memory is addressable in units of any integral multiple of 8 bits.
1590 Allows to break when an Ada exception is handled.
1592 * New remote packets
1595 Indicates that an exec system call was executed.
1597 exec-events feature in qSupported
1598 The qSupported packet allows GDB to request support for exec
1599 events using the new 'gdbfeature' exec-event, and the qSupported
1600 response can contain the corresponding 'stubfeature'. Set and
1601 show commands can be used to display whether these features are enabled.
1604 Equivalent to interrupting with the ^C character, but works in
1607 thread created stop reason (T05 create:...)
1608 Indicates that the thread was just created and is stopped at entry.
1610 thread exit stop reply (w exitcode;tid)
1611 Indicates that the thread has terminated.
1614 Enables/disables thread create and exit event reporting. For
1615 example, this is used in non-stop mode when GDB stops a set of
1616 threads and synchronously waits for the their corresponding stop
1617 replies. Without exit events, if one of the threads exits, GDB
1618 would hang forever not knowing that it should no longer expect a
1619 stop for that same thread.
1622 Indicates that there are no resumed threads left in the target (all
1623 threads are stopped). The remote stub reports support for this stop
1624 reply to GDB's qSupported query.
1627 Enables/disables catching syscalls from the inferior process.
1628 The remote stub reports support for this packet to GDB's qSupported query.
1630 syscall_entry stop reason
1631 Indicates that a syscall was just called.
1633 syscall_return stop reason
1634 Indicates that a syscall just returned.
1636 * Extended-remote exec events
1638 ** GDB now has support for exec events on extended-remote Linux targets.
1639 For such targets with Linux kernels 2.5.46 and later, this enables
1640 follow-exec-mode and exec catchpoints.
1642 set remote exec-event-feature-packet
1643 show remote exec-event-feature-packet
1644 Set/show the use of the remote exec event feature.
1646 * Thread names in remote protocol
1648 The reply to qXfer:threads:read may now include a name attribute for each
1651 * Target remote mode fork and exec events
1653 ** GDB now has support for fork and exec events on target remote mode
1654 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1655 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1656 fork and exec catchpoints.
1658 * Remote syscall events
1660 ** GDB now has support for catch syscall on remote Linux targets,
1661 currently enabled on x86/x86_64 architectures.
1663 set remote catch-syscall-packet
1664 show remote catch-syscall-packet
1665 Set/show the use of the remote catch syscall feature.
1669 ** The -var-set-format command now accepts the zero-hexadecimal
1670 format. It outputs data in hexadecimal format with zero-padding on the
1675 ** gdb.InferiorThread objects have a new attribute "global_num",
1676 which refers to the thread's global thread ID. The existing
1677 "num" attribute now refers to the thread's per-inferior number.
1678 See "Per-inferior thread numbers" above.
1679 ** gdb.InferiorThread objects have a new attribute "inferior", which
1680 is the Inferior object the thread belongs to.
1682 *** Changes in GDB 7.10
1684 * Support for process record-replay and reverse debugging on aarch64*-linux*
1685 targets has been added. GDB now supports recording of A64 instruction set
1686 including advance SIMD instructions.
1688 * Support for Sun's version of the "stabs" debug file format has been removed.
1690 * GDB now honors the content of the file /proc/PID/coredump_filter
1691 (PID is the process ID) on GNU/Linux systems. This file can be used
1692 to specify the types of memory mappings that will be included in a
1693 corefile. For more information, please refer to the manual page of
1694 "core(5)". GDB also has a new command: "set use-coredump-filter
1695 on|off". It allows to set whether GDB will read the content of the
1696 /proc/PID/coredump_filter file when generating a corefile.
1698 * The "info os" command on GNU/Linux can now display information on
1700 "info os cpus" Listing of all cpus/cores on the system
1702 * GDB has two new commands: "set serial parity odd|even|none" and
1703 "show serial parity". These allows to set or show parity for the
1706 * The "info source" command now displays the producer string if it was
1707 present in the debug info. This typically includes the compiler version
1708 and may include things like its command line arguments.
1710 * The "info dll", an alias of the "info sharedlibrary" command,
1711 is now available on all platforms.
1713 * Directory names supplied to the "set sysroot" commands may be
1714 prefixed with "target:" to tell GDB to access shared libraries from
1715 the target system, be it local or remote. This replaces the prefix
1716 "remote:". The default sysroot has been changed from "" to
1717 "target:". "remote:" is automatically converted to "target:" for
1718 backward compatibility.
1720 * The system root specified by "set sysroot" will be prepended to the
1721 filename of the main executable (if reported to GDB as absolute by
1722 the operating system) when starting processes remotely, and when
1723 attaching to already-running local or remote processes.
1725 * GDB now supports automatic location and retrieval of executable
1726 files from remote targets. Remote debugging can now be initiated
1727 using only a "target remote" or "target extended-remote" command
1728 (no "set sysroot" or "file" commands are required). See "New remote
1731 * The "dump" command now supports verilog hex format.
1733 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1735 * On GNU/Linux, GDB and gdbserver are now able to access executable
1736 and shared library files without a "set sysroot" command when
1737 attaching to processes running in different mount namespaces from
1738 the debugger. This makes it possible to attach to processes in
1739 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1740 See "New remote packets" below.
1742 * The "tui reg" command now provides completion for all of the
1743 available register groups, including target specific groups.
1745 * The HISTSIZE environment variable is no longer read when determining
1746 the size of GDB's command history. GDB now instead reads the dedicated
1747 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1748 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1753 ** Memory ports can now be unbuffered.
1757 ** gdb.Objfile objects have a new attribute "username",
1758 which is the name of the objfile as specified by the user,
1759 without, for example, resolving symlinks.
1760 ** You can now write frame unwinders in Python.
1761 ** gdb.Type objects have a new method "optimized_out",
1762 returning optimized out gdb.Value instance of this type.
1763 ** gdb.Value objects have new methods "reference_value" and
1764 "const_value" which return a reference to the value and a
1765 "const" version of the value respectively.
1769 maint print symbol-cache
1770 Print the contents of the symbol cache.
1772 maint print symbol-cache-statistics
1773 Print statistics of symbol cache usage.
1775 maint flush-symbol-cache
1776 Flush the contents of the symbol cache.
1780 Start branch trace recording using Branch Trace Store (BTS) format.
1783 Evaluate expression by using the compiler and print result.
1787 Explicit commands for enabling and disabling tui mode.
1790 set mpx bound on i386 and amd64
1791 Support for bound table investigation on Intel MPX enabled applications.
1795 Start branch trace recording using Intel Processor Trace format.
1798 Print information about branch tracing internals.
1800 maint btrace packet-history
1801 Print the raw branch tracing data.
1803 maint btrace clear-packet-history
1804 Discard the stored raw branch tracing data.
1807 Discard all branch tracing data. It will be fetched and processed
1808 anew by the next "record" command.
1813 Renamed from "set debug dwarf2-die".
1814 show debug dwarf-die
1815 Renamed from "show debug dwarf2-die".
1817 set debug dwarf-read
1818 Renamed from "set debug dwarf2-read".
1819 show debug dwarf-read
1820 Renamed from "show debug dwarf2-read".
1822 maint set dwarf always-disassemble
1823 Renamed from "maint set dwarf2 always-disassemble".
1824 maint show dwarf always-disassemble
1825 Renamed from "maint show dwarf2 always-disassemble".
1827 maint set dwarf max-cache-age
1828 Renamed from "maint set dwarf2 max-cache-age".
1829 maint show dwarf max-cache-age
1830 Renamed from "maint show dwarf2 max-cache-age".
1832 set debug dwarf-line
1833 show debug dwarf-line
1834 Control display of debugging info regarding DWARF line processing.
1837 show max-completions
1838 Set the maximum number of candidates to be considered during
1839 completion. The default value is 200. This limit allows GDB
1840 to avoid generating large completion lists, the computation of
1841 which can cause the debugger to become temporarily unresponsive.
1843 set history remove-duplicates
1844 show history remove-duplicates
1845 Control the removal of duplicate history entries.
1847 maint set symbol-cache-size
1848 maint show symbol-cache-size
1849 Control the size of the symbol cache.
1851 set|show record btrace bts buffer-size
1852 Set and show the size of the ring buffer used for branch tracing in
1854 The obtained size may differ from the requested size. Use "info
1855 record" to see the obtained buffer size.
1857 set debug linux-namespaces
1858 show debug linux-namespaces
1859 Control display of debugging info regarding Linux namespaces.
1861 set|show record btrace pt buffer-size
1862 Set and show the size of the ring buffer used for branch tracing in
1863 Intel Processor Trace format.
1864 The obtained size may differ from the requested size. Use "info
1865 record" to see the obtained buffer size.
1867 maint set|show btrace pt skip-pad
1868 Set and show whether PAD packets are skipped when computing the
1871 * The command 'thread apply all' can now support new option '-ascending'
1872 to call its specified command for all threads in ascending order.
1874 * Python/Guile scripting
1876 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1877 special section named `.debug_gdb_scripts'.
1879 * New remote packets
1881 qXfer:btrace-conf:read
1882 Return the branch trace configuration for the current thread.
1884 Qbtrace-conf:bts:size
1885 Set the requested ring buffer size for branch tracing in BTS format.
1888 Enable Intel Procesor Trace-based branch tracing for the current
1889 process. The remote stub reports support for this packet to GDB's
1892 Qbtrace-conf:pt:size
1893 Set the requested ring buffer size for branch tracing in Intel Processor
1897 Indicates a memory breakpoint instruction was executed, irrespective
1898 of whether it was GDB that planted the breakpoint or the breakpoint
1899 is hardcoded in the program. This is required for correct non-stop
1903 Indicates the target stopped for a hardware breakpoint. This is
1904 required for correct non-stop mode operation.
1907 Return information about files on the remote system.
1909 qXfer:exec-file:read
1910 Return the full absolute name of the file that was executed to
1911 create a process running on the remote system.
1914 Select the filesystem on which vFile: operations with filename
1915 arguments will operate. This is required for GDB to be able to
1916 access files on remote targets where the remote stub does not
1917 share a common filesystem with the inferior(s).
1920 Indicates that a fork system call was executed.
1923 Indicates that a vfork system call was executed.
1925 vforkdone stop reason
1926 Indicates that a vfork child of the specified process has executed
1927 an exec or exit, allowing the vfork parent to resume execution.
1929 fork-events and vfork-events features in qSupported
1930 The qSupported packet allows GDB to request support for fork and
1931 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1932 and the qSupported response can contain the corresponding
1933 'stubfeatures'. Set and show commands can be used to display
1934 whether these features are enabled.
1936 * Extended-remote fork events
1938 ** GDB now has support for fork events on extended-remote Linux
1939 targets. For targets with Linux kernels 2.5.60 and later, this
1940 enables follow-fork-mode and detach-on-fork for both fork and
1941 vfork, as well as fork and vfork catchpoints.
1943 * The info record command now shows the recording format and the
1944 branch tracing configuration for the current thread when using
1945 the btrace record target.
1946 For the BTS format, it shows the ring buffer size.
1948 * GDB now has support for DTrace USDT (Userland Static Defined
1949 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1951 * GDB now supports access to vector registers on S/390 GNU/Linux
1954 * Removed command line options
1956 -xdb HP-UX XDB compatibility mode.
1958 * Removed targets and native configurations
1960 HP/PA running HP-UX hppa*-*-hpux*
1961 Itanium running HP-UX ia64-*-hpux*
1963 * New configure options
1966 This configure option allows the user to build GDB with support for
1967 Intel Processor Trace (default: auto). This requires libipt.
1969 --with-libipt-prefix=PATH
1970 Specify the path to the version of libipt that GDB should use.
1971 $PATH/include should contain the intel-pt.h header and
1972 $PATH/lib should contain the libipt.so library.
1974 *** Changes in GDB 7.9.1
1978 ** Xmethods can now specify a result type.
1980 *** Changes in GDB 7.9
1982 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1986 ** You can now access frame registers from Python scripts.
1987 ** New attribute 'producer' for gdb.Symtab objects.
1988 ** gdb.Objfile objects have a new attribute "progspace",
1989 which is the gdb.Progspace object of the containing program space.
1990 ** gdb.Objfile objects have a new attribute "owner".
1991 ** gdb.Objfile objects have a new attribute "build_id",
1992 which is the build ID generated when the file was built.
1993 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1994 ** A new event "gdb.clear_objfiles" has been added, triggered when
1995 selecting a new file to debug.
1996 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1997 ** New function gdb.lookup_objfile.
1999 New events which are triggered when GDB modifies the state of the
2002 ** gdb.events.inferior_call_pre: Function call is about to be made.
2003 ** gdb.events.inferior_call_post: Function call has just been made.
2004 ** gdb.events.memory_changed: A memory location has been altered.
2005 ** gdb.events.register_changed: A register has been altered.
2007 * New Python-based convenience functions:
2009 ** $_caller_is(name [, number_of_frames])
2010 ** $_caller_matches(regexp [, number_of_frames])
2011 ** $_any_caller_is(name [, number_of_frames])
2012 ** $_any_caller_matches(regexp [, number_of_frames])
2014 * GDB now supports the compilation and injection of source code into
2015 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2016 to compile the source code to object code, and if successful, inject
2017 and execute that code within the current context of the inferior.
2018 Currently the C language is supported. The commands used to
2019 interface with this new feature are:
2021 compile code [-raw|-r] [--] [source code]
2022 compile file [-raw|-r] filename
2026 demangle [-l language] [--] name
2027 Demangle "name" in the specified language, or the current language
2028 if elided. This command is renamed from the "maint demangle" command.
2029 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2030 as "maint demangler-warning".
2032 queue-signal signal-name-or-number
2033 Queue a signal to be delivered to the thread when it is resumed.
2035 add-auto-load-scripts-directory directory
2036 Add entries to the list of directories from which to load auto-loaded
2039 maint print user-registers
2040 List all currently available "user" registers.
2042 compile code [-r|-raw] [--] [source code]
2043 Compile, inject, and execute in the inferior the executable object
2044 code produced by compiling the provided source code.
2046 compile file [-r|-raw] filename
2047 Compile and inject into the inferior the executable object code
2048 produced by compiling the source code stored in the filename
2051 * On resume, GDB now always passes the signal the program had stopped
2052 for to the thread the signal was sent to, even if the user changed
2053 threads before resuming. Previously GDB would often (but not
2054 always) deliver the signal to the thread that happens to be current
2057 * Conversely, the "signal" command now consistently delivers the
2058 requested signal to the current thread. GDB now asks for
2059 confirmation if the program had stopped for a signal and the user
2060 switched threads meanwhile.
2062 * "breakpoint always-inserted" modes "off" and "auto" merged.
2064 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2065 won't remove breakpoints from the target until all threads stop,
2066 even in non-stop mode. The "auto" mode has been removed, and "off"
2067 is now the default mode.
2071 set debug symbol-lookup
2072 show debug symbol-lookup
2073 Control display of debugging info regarding symbol lookup.
2077 ** The -list-thread-groups command outputs an exit-code field for
2078 inferiors that have exited.
2082 MIPS SDE mips*-sde*-elf*
2086 Support for these obsolete configurations has been removed.
2088 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2089 SGI Irix-5.x mips-*-irix5*
2090 SGI Irix-6.x mips-*-irix6*
2091 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2092 VAX running Ultrix vax-*-ultrix*
2094 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2095 and "assf"), have been removed. Use the "sharedlibrary" command, or
2096 its alias "share", instead.
2098 *** Changes in GDB 7.8
2100 * New command line options
2103 This is an alias for the --data-directory option.
2105 * GDB supports printing and modifying of variable length automatic arrays
2106 as specified in ISO C99.
2108 * The ARM simulator now supports instruction level tracing
2109 with or without disassembly.
2113 GDB now has support for scripting using Guile. Whether this is
2114 available is determined at configure time.
2115 Guile version 2.0 or greater is required.
2116 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2118 * New commands (for set/show, see "New options" below)
2122 Invoke CODE by passing it to the Guile interpreter.
2126 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2128 info auto-load guile-scripts [regexp]
2129 Print the list of automatically loaded Guile scripts.
2131 * The source command is now capable of sourcing Guile scripts.
2132 This feature is dependent on the debugger being built with Guile support.
2136 set print symbol-loading (off|brief|full)
2137 show print symbol-loading
2138 Control whether to print informational messages when loading symbol
2139 information for a file. The default is "full", but when debugging
2140 programs with large numbers of shared libraries the amount of output
2141 becomes less useful.
2143 set guile print-stack (none|message|full)
2144 show guile print-stack
2145 Show a stack trace when an error is encountered in a Guile script.
2147 set auto-load guile-scripts (on|off)
2148 show auto-load guile-scripts
2149 Control auto-loading of Guile script files.
2151 maint ada set ignore-descriptive-types (on|off)
2152 maint ada show ignore-descriptive-types
2153 Control whether the debugger should ignore descriptive types in Ada
2154 programs. The default is not to ignore the descriptive types. See
2155 the user manual for more details on descriptive types and the intended
2156 usage of this option.
2158 set auto-connect-native-target
2160 Control whether GDB is allowed to automatically connect to the
2161 native target for the run, attach, etc. commands when not connected
2162 to any target yet. See also "target native" below.
2164 set record btrace replay-memory-access (read-only|read-write)
2165 show record btrace replay-memory-access
2166 Control what memory accesses are allowed during replay.
2168 maint set target-async (on|off)
2169 maint show target-async
2170 This controls whether GDB targets operate in synchronous or
2171 asynchronous mode. Normally the default is asynchronous, if it is
2172 available; but this can be changed to more easily debug problems
2173 occurring only in synchronous mode.
2175 set mi-async (on|off)
2177 Control whether MI asynchronous mode is preferred. This supersedes
2178 "set target-async" of previous GDB versions.
2180 * "set target-async" is deprecated as a CLI option and is now an alias
2181 for "set mi-async" (only puts MI into async mode).
2183 * Background execution commands (e.g., "c&", "s&", etc.) are now
2184 possible ``out of the box'' if the target supports them. Previously
2185 the user would need to explicitly enable the possibility with the
2186 "set target-async on" command.
2188 * New features in the GDB remote stub, GDBserver
2190 ** New option --debug-format=option1[,option2,...] allows one to add
2191 additional text to each output. At present only timestamps
2192 are supported: --debug-format=timestamps.
2193 Timestamps can also be turned on with the
2194 "monitor set debug-format timestamps" command from GDB.
2196 * The 'record instruction-history' command now starts counting instructions
2197 at one. This also affects the instruction ranges reported by the
2198 'record function-call-history' command when given the /i modifier.
2200 * The command 'record function-call-history' supports a new modifier '/c' to
2201 indent the function names based on their call stack depth.
2202 The fields for the '/i' and '/l' modifier have been reordered.
2203 The source line range is now prefixed with 'at'.
2204 The instruction range is now prefixed with 'inst'.
2205 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2206 "record instruction-history" and "list" commands.
2208 * The ranges given as arguments to the 'record function-call-history' and
2209 'record instruction-history' commands are now inclusive.
2211 * The btrace record target now supports the 'record goto' command.
2212 For locations inside the execution trace, the back trace is computed
2213 based on the information stored in the execution trace.
2215 * The btrace record target supports limited reverse execution and replay.
2216 The target does not record data and therefore does not allow reading
2217 memory or registers.
2219 * The "catch syscall" command now works on s390*-linux* targets.
2221 * The "compare-sections" command is no longer specific to target
2222 remote. It now works with all targets.
2224 * All native targets are now consistently called "native".
2225 Consequently, the "target child", "target GNU", "target djgpp",
2226 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2227 commands have been replaced with "target native". The QNX/NTO port
2228 leaves the "procfs" target in place and adds a "native" target for
2229 consistency with other ports. The impact on users should be minimal
2230 as these commands previously either throwed an error, or were
2231 no-ops. The target's name is visible in the output of the following
2232 commands: "help target", "info target", "info files", "maint print
2235 * The "target native" command now connects to the native target. This
2236 can be used to launch native programs even when "set
2237 auto-connect-native-target" is set to off.
2239 * GDB now supports access to Intel MPX registers on GNU/Linux.
2241 * Support for Intel AVX-512 registers on GNU/Linux.
2242 Support displaying and modifying Intel AVX-512 registers
2243 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2245 * New remote packets
2247 qXfer:btrace:read's annex
2248 The qXfer:btrace:read packet supports a new annex 'delta' to read
2249 branch trace incrementally.
2253 ** Valid Python operations on gdb.Value objects representing
2254 structs/classes invoke the corresponding overloaded operators if
2256 ** New `Xmethods' feature in the Python API. Xmethods are
2257 additional methods or replacements for existing methods of a C++
2258 class. This feature is useful for those cases where a method
2259 defined in C++ source code could be inlined or optimized out by
2260 the compiler, making it unavailable to GDB.
2263 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2265 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2266 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2267 its alias "share", instead.
2269 * The commands "set remotebaud" and "show remotebaud" are no longer
2270 supported. Use "set serial baud" and "show serial baud" (respectively)
2275 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2276 target-async". The latter is left as a deprecated alias of the
2277 former for backward compatibility. If the target supports it,
2278 CLI background execution commands are now always possible by
2279 default, independently of whether the frontend stated a
2280 preference for asynchronous execution with "-gdb-set mi-async".
2281 Previously "-gdb-set target-async off" affected both MI execution
2282 commands and CLI execution commands.
2284 *** Changes in GDB 7.7
2286 * Improved support for process record-replay and reverse debugging on
2287 arm*-linux* targets. Support for thumb32 and syscall instruction
2288 recording has been added.
2290 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2292 * GDB now supports Fission DWP file format version 2.
2293 http://gcc.gnu.org/wiki/DebugFission
2295 * New convenience function "$_isvoid", to check whether an expression
2296 is void. A void expression is an expression where the type of the
2297 result is "void". For example, some convenience variables may be
2298 "void" when evaluated (e.g., "$_exitcode" before the execution of
2299 the program being debugged; or an undefined convenience variable).
2300 Another example, when calling a function whose return type is
2303 * The "maintenance print objfiles" command now takes an optional regexp.
2305 * The "catch syscall" command now works on arm*-linux* targets.
2307 * GDB now consistently shows "<not saved>" when printing values of
2308 registers the debug info indicates have not been saved in the frame
2309 and there's nowhere to retrieve them from
2310 (callee-saved/call-clobbered registers):
2315 (gdb) info registers rax
2318 Before, the former would print "<optimized out>", and the latter
2319 "*value not available*".
2321 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2326 ** Frame filters and frame decorators have been added.
2327 ** Temporary breakpoints are now supported.
2328 ** Line tables representation has been added.
2329 ** New attribute 'parent_type' for gdb.Field objects.
2330 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2331 ** New attribute 'name' for gdb.Type objects.
2335 Nios II ELF nios2*-*-elf
2336 Nios II GNU/Linux nios2*-*-linux
2337 Texas Instruments MSP430 msp430*-*-elf
2339 * Removed native configurations
2341 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2342 been removed. ELF variants of these configurations are kept supported.
2344 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2345 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2346 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2347 i[34567]86-*-openbsd3.[0-3]
2348 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2349 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2350 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2354 Like "catch throw", but catches a re-thrown exception.
2355 maint check-psymtabs
2356 Renamed from old "maint check-symtabs".
2358 Perform consistency checks on symtabs.
2359 maint expand-symtabs
2360 Expand symtabs matching an optional regexp.
2363 Display the details of GDB configure-time options.
2365 maint set|show per-command
2366 maint set|show per-command space
2367 maint set|show per-command time
2368 maint set|show per-command symtab
2369 Enable display of per-command gdb resource usage.
2371 remove-symbol-file FILENAME
2372 remove-symbol-file -a ADDRESS
2373 Remove a symbol file added via add-symbol-file. The file to remove
2374 can be identified by its filename or by an address that lies within
2375 the boundaries of this symbol file in memory.
2378 info exceptions REGEXP
2379 Display the list of Ada exceptions defined in the program being
2380 debugged. If provided, only the exceptions whose names match REGEXP
2385 set debug symfile off|on
2387 Control display of debugging info regarding reading symbol files and
2388 symbol tables within those files
2390 set print raw frame-arguments
2391 show print raw frame-arguments
2392 Set/show whether to print frame arguments in raw mode,
2393 disregarding any defined pretty-printers.
2395 set remote trace-status-packet
2396 show remote trace-status-packet
2397 Set/show the use of remote protocol qTStatus packet.
2401 Control display of debugging messages related to Nios II targets.
2405 Control whether target-assisted range stepping is enabled.
2407 set startup-with-shell
2408 show startup-with-shell
2409 Specifies whether Unix child processes are started via a shell or
2414 Use the target memory cache for accesses to the code segment. This
2415 improves performance of remote debugging (particularly disassembly).
2417 * You can now use a literal value 'unlimited' for options that
2418 interpret 0 or -1 as meaning "unlimited". E.g., "set
2419 trace-buffer-size unlimited" is now an alias for "set
2420 trace-buffer-size -1" and "set height unlimited" is now an alias for
2423 * The "set debug symtab-create" debugging option of GDB has been changed to
2424 accept a verbosity level. 0 means "off", 1 provides basic debugging
2425 output, and values of 2 or greater provides more verbose output.
2427 * New command-line options
2429 Display the details of GDB configure-time options.
2431 * The command 'tsave' can now support new option '-ctf' to save trace
2432 buffer in Common Trace Format.
2434 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2437 * GDB now implements the C++ 'typeid' operator.
2439 * The new convenience variable $_exception holds the exception being
2440 thrown or caught at an exception-related catchpoint.
2442 * The exception-related catchpoints, like "catch throw", now accept a
2443 regular expression which can be used to filter exceptions by type.
2445 * The new convenience variable $_exitsignal is automatically set to
2446 the terminating signal number when the program being debugged dies
2447 due to an uncaught signal.
2451 ** All MI commands now accept an optional "--language" option.
2452 Support for this feature can be verified by using the "-list-features"
2453 command, which should contain "language-option".
2455 ** The new command -info-gdb-mi-command allows the user to determine
2456 whether a GDB/MI command is supported or not.
2458 ** The "^error" result record returned when trying to execute an undefined
2459 GDB/MI command now provides a variable named "code" whose content is the
2460 "undefined-command" error code. Support for this feature can be verified
2461 by using the "-list-features" command, which should contain
2462 "undefined-command-error-code".
2464 ** The -trace-save MI command can optionally save trace buffer in Common
2467 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2469 ** The command -data-list-register-values now accepts an optional
2470 "--skip-unavailable" option. When used, only the available registers
2473 ** The new command -trace-frame-collected dumps collected variables,
2474 computed expressions, tvars, memory and registers in a traceframe.
2476 ** The commands -stack-list-locals, -stack-list-arguments and
2477 -stack-list-variables now accept an option "--skip-unavailable".
2478 When used, only the available locals or arguments are displayed.
2480 ** The -exec-run command now accepts an optional "--start" option.
2481 When used, the command follows the same semantics as the "start"
2482 command, stopping the program's execution at the start of its
2483 main subprogram. Support for this feature can be verified using
2484 the "-list-features" command, which should contain
2485 "exec-run-start-option".
2487 ** The new commands -catch-assert and -catch-exceptions insert
2488 catchpoints stopping the program when Ada exceptions are raised.
2490 ** The new command -info-ada-exceptions provides the equivalent of
2491 the new "info exceptions" command.
2493 * New system-wide configuration scripts
2494 A GDB installation now provides scripts suitable for use as system-wide
2495 configuration scripts for the following systems:
2499 * GDB now supports target-assigned range stepping with remote targets.
2500 This improves the performance of stepping source lines by reducing
2501 the number of control packets from/to GDB. See "New remote packets"
2504 * GDB now understands the element 'tvar' in the XML traceframe info.
2505 It has the id of the collected trace state variables.
2507 * On S/390 targets that provide the transactional-execution feature,
2508 the program interruption transaction diagnostic block (TDB) is now
2509 represented as a number of additional "registers" in GDB.
2511 * New remote packets
2515 The vCont packet supports a new 'r' action, that tells the remote
2516 stub to step through an address range itself, without GDB
2517 involvemement at each single-step.
2519 qXfer:libraries-svr4:read's annex
2520 The previously unused annex of the qXfer:libraries-svr4:read packet
2521 is now used to support passing an argument list. The remote stub
2522 reports support for this argument list to GDB's qSupported query.
2523 The defined arguments are "start" and "prev", used to reduce work
2524 necessary for library list updating, resulting in significant
2527 * New features in the GDB remote stub, GDBserver
2529 ** GDBserver now supports target-assisted range stepping. Currently
2530 enabled on x86/x86_64 GNU/Linux targets.
2532 ** GDBserver now adds element 'tvar' in the XML in the reply to
2533 'qXfer:traceframe-info:read'. It has the id of the collected
2534 trace state variables.
2536 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2539 * New 'z' formatter for printing and examining memory, this displays the
2540 value as hexadecimal zero padded on the left to the size of the type.
2542 * GDB can now use Windows x64 unwinding data.
2544 * The "set remotebaud" command has been replaced by "set serial baud".
2545 Similarly, "show remotebaud" has been replaced by "show serial baud".
2546 The "set remotebaud" and "show remotebaud" commands are still available
2547 to provide backward compatibility with older versions of GDB.
2549 *** Changes in GDB 7.6
2551 * Target record has been renamed to record-full.
2552 Record/replay is now enabled with the "record full" command.
2553 This also affects settings that are associated with full record/replay
2554 that have been moved from "set/show record" to "set/show record full":
2556 set|show record full insn-number-max
2557 set|show record full stop-at-limit
2558 set|show record full memory-query
2560 * A new record target "record-btrace" has been added. The new target
2561 uses hardware support to record the control-flow of a process. It
2562 does not support replaying the execution, but it implements the
2563 below new commands for investigating the recorded execution log.
2564 This new recording method can be enabled using:
2568 The "record-btrace" target is only available on Intel Atom processors
2569 and requires a Linux kernel 2.6.32 or later.
2571 * Two new commands have been added for record/replay to give information
2572 about the recorded execution without having to replay the execution.
2573 The commands are only supported by "record btrace".
2575 record instruction-history prints the execution history at
2576 instruction granularity
2578 record function-call-history prints the execution history at
2579 function granularity
2581 * New native configurations
2583 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2584 FreeBSD/powerpc powerpc*-*-freebsd
2585 x86_64/Cygwin x86_64-*-cygwin*
2586 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2590 ARM AArch64 aarch64*-*-elf
2591 ARM AArch64 GNU/Linux aarch64*-*-linux
2592 Lynx 178 PowerPC powerpc-*-lynx*178
2593 x86_64/Cygwin x86_64-*-cygwin*
2594 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2596 * If the configured location of system.gdbinit file (as given by the
2597 --with-system-gdbinit option at configure time) is in the
2598 data-directory (as specified by --with-gdb-datadir at configure
2599 time) or in one of its subdirectories, then GDB will look for the
2600 system-wide init file in the directory specified by the
2601 --data-directory command-line option.
2603 * New command line options:
2605 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2606 other initialization files, unlike -nx which disables all of them.
2608 * Removed command line options
2610 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2613 * The 'ptype' and 'whatis' commands now accept an argument to control
2616 * 'info proc' now works on some core files.
2620 ** Vectors can be created with gdb.Type.vector.
2622 ** Python's atexit.register now works in GDB.
2624 ** Types can be pretty-printed via a Python API.
2626 ** Python 3 is now supported (in addition to Python 2.4 or later)
2628 ** New class gdb.Architecture exposes GDB's internal representation
2629 of architecture in the Python API.
2631 ** New method Frame.architecture returns the gdb.Architecture object
2632 corresponding to the frame's architecture.
2634 * New Python-based convenience functions:
2636 ** $_memeq(buf1, buf2, length)
2637 ** $_streq(str1, str2)
2639 ** $_regex(str, regex)
2641 * The 'cd' command now defaults to using '~' (the home directory) if not
2644 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2645 default for GCC since November 2000.
2647 * The command 'forward-search' can now be abbreviated as 'fo'.
2649 * The command 'info tracepoints' can now display 'installed on target'
2650 or 'not installed on target' for each non-pending location of tracepoint.
2652 * New configure options
2654 --enable-libmcheck/--disable-libmcheck
2655 By default, development versions are built with -lmcheck on hosts
2656 that support it, in order to help track memory corruption issues.
2657 Release versions, on the other hand, are built without -lmcheck
2658 by default. The --enable-libmcheck/--disable-libmcheck configure
2659 options allow the user to override that default.
2660 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2661 This configure option allows the user to build GDB with
2662 libbabeltrace using which GDB can read Common Trace Format data.
2664 * New commands (for set/show, see "New options" below)
2667 Catch signals. This is similar to "handle", but allows commands and
2668 conditions to be attached.
2671 List the BFDs known to GDB.
2673 python-interactive [command]
2675 Start a Python interactive prompt, or evaluate the optional command
2676 and print the result of expressions.
2679 "py" is a new alias for "python".
2681 enable type-printer [name]...
2682 disable type-printer [name]...
2683 Enable or disable type printers.
2687 ** For the Renesas Super-H architecture, the "regs" command has been removed
2688 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2693 set print type methods (on|off)
2694 show print type methods
2695 Control whether method declarations are displayed by "ptype".
2696 The default is to show them.
2698 set print type typedefs (on|off)
2699 show print type typedefs
2700 Control whether typedef definitions are displayed by "ptype".
2701 The default is to show them.
2703 set filename-display basename|relative|absolute
2704 show filename-display
2705 Control the way in which filenames is displayed.
2706 The default is "relative", which preserves previous behavior.
2708 set trace-buffer-size
2709 show trace-buffer-size
2710 Request target to change the size of trace buffer.
2712 set remote trace-buffer-size-packet auto|on|off
2713 show remote trace-buffer-size-packet
2714 Control the use of the remote protocol `QTBuffer:size' packet.
2718 Control display of debugging messages related to ARM AArch64.
2721 set debug coff-pe-read
2722 show debug coff-pe-read
2723 Control display of debugging messages related to reading of COFF/PE
2728 Control display of debugging messages related to Mach-O symbols
2731 set debug notification
2732 show debug notification
2733 Control display of debugging info for async remote notification.
2737 ** Command parameter changes are now notified using new async record
2738 "=cmd-param-changed".
2739 ** Trace frame changes caused by command "tfind" are now notified using
2740 new async record "=traceframe-changed".
2741 ** The creation, deletion and modification of trace state variables
2742 are now notified using new async records "=tsv-created",
2743 "=tsv-deleted" and "=tsv-modified".
2744 ** The start and stop of process record are now notified using new
2745 async record "=record-started" and "=record-stopped".
2746 ** Memory changes are now notified using new async record
2748 ** The data-disassemble command response will include a "fullname" field
2749 containing the absolute file name when source has been requested.
2750 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2751 command, to allow pattern filling of memory areas.
2752 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2753 library load/unload events.
2754 ** The response to breakpoint commands and breakpoint async records
2755 includes an "installed" field containing a boolean state about each
2756 non-pending tracepoint location is whether installed on target or not.
2757 ** Output of the "-trace-status" command includes a "trace-file" field
2758 containing the name of the trace file being examined. This field is
2759 optional, and only present when examining a trace file.
2760 ** The "fullname" field is now always present along with the "file" field,
2761 even if the file cannot be found by GDB.
2763 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2764 You must have the LZMA library available when configuring GDB for this
2765 feature to be enabled. For more information, see:
2766 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2768 * New remote packets
2771 Set the size of trace buffer. The remote stub reports support for this
2772 packet to gdb's qSupported query.
2775 Enable Branch Trace Store (BTS)-based branch tracing for the current
2776 thread. The remote stub reports support for this packet to gdb's
2780 Disable branch tracing for the current thread. The remote stub reports
2781 support for this packet to gdb's qSupported query.
2784 Read the traced branches for the current thread. The remote stub
2785 reports support for this packet to gdb's qSupported query.
2787 *** Changes in GDB 7.5
2789 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2790 for more x32 ABI info.
2792 * GDB now supports access to MIPS DSP registers on Linux targets.
2794 * GDB now supports debugging microMIPS binaries.
2796 * The "info os" command on GNU/Linux can now display information on
2797 several new classes of objects managed by the operating system:
2798 "info os procgroups" lists process groups
2799 "info os files" lists file descriptors
2800 "info os sockets" lists internet-domain sockets
2801 "info os shm" lists shared-memory regions
2802 "info os semaphores" lists semaphores
2803 "info os msg" lists message queues
2804 "info os modules" lists loaded kernel modules
2806 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2807 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2808 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2809 options and inspect the probe arguments using the new $_probe_arg family
2810 of convenience variables. You can obtain more information about SystemTap
2811 in <http://sourceware.org/systemtap/>.
2813 * GDB now supports reversible debugging on ARM, it allows you to
2814 debug basic ARM and THUMB instructions, and provides
2815 record/replay support.
2817 * The option "symbol-reloading" has been deleted as it is no longer used.
2821 ** GDB commands implemented in Python can now be put in command class
2824 ** The "maint set python print-stack on|off" is now deleted.
2826 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2827 apply "flag enum"-style pretty-printing to any enum.
2829 ** gdb.lookup_symbol can now work when there is no current frame.
2831 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2832 the source at which the symbol was defined.
2834 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2835 method 'value'. The former indicates whether the symbol needs a
2836 frame in order to compute its value, and the latter computes the
2839 ** A new method 'referenced_value' on gdb.Value objects which can
2840 dereference pointer as well as C++ reference values.
2842 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2843 which return the global and static blocks (as gdb.Block objects),
2844 of the underlying symbol table, respectively.
2846 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2847 object associated with a PC value.
2849 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2850 of the address range occupied by code for the current source line.
2852 * Go language support.
2853 GDB now supports debugging programs written in the Go programming
2856 * GDBserver now supports stdio connections.
2857 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2859 * The binary "gdbtui" can no longer be built or installed.
2860 Use "gdb -tui" instead.
2862 * GDB will now print "flag" enums specially. A flag enum is one where
2863 all the enumerator values have no bits in common when pairwise
2864 "and"ed. When printing a value whose type is a flag enum, GDB will
2865 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2866 (gdb) print (enum E) 3
2869 * The filename part of a linespec will now match trailing components
2870 of a source file name. For example, "break gcc/expr.c:1000" will
2871 now set a breakpoint in build/gcc/expr.c, but not
2872 build/libcpp/expr.c.
2874 * The "info proc" and "generate-core-file" commands will now also
2875 work on remote targets connected to GDBserver on Linux.
2877 * The command "info catch" has been removed. It has been disabled
2878 since December 2007.
2880 * The "catch exception" and "catch assert" commands now accept
2881 a condition at the end of the command, much like the "break"
2882 command does. For instance:
2884 (gdb) catch exception Constraint_Error if Barrier = True
2886 Previously, it was possible to add a condition to such catchpoints,
2887 but it had to be done as a second step, after the catchpoint had been
2888 created, using the "condition" command.
2890 * The "info static-tracepoint-marker" command will now also work on
2891 native Linux targets with in-process agent.
2893 * GDB can now set breakpoints on inlined functions.
2895 * The .gdb_index section has been updated to include symbols for
2896 inlined functions. GDB will ignore older .gdb_index sections by
2897 default, which could cause symbol files to be loaded more slowly
2898 until their .gdb_index sections can be recreated. The new command
2899 "set use-deprecated-index-sections on" will cause GDB to use any older
2900 .gdb_index sections it finds. This will restore performance, but the
2901 ability to set breakpoints on inlined functions will be lost in symbol
2902 files with older .gdb_index sections.
2904 The .gdb_index section has also been updated to record more information
2905 about each symbol. This speeds up the "info variables", "info functions"
2906 and "info types" commands when used with programs having the .gdb_index
2907 section, as well as speeding up debugging with shared libraries using
2908 the .gdb_index section.
2910 * Ada support for GDB/MI Variable Objects has been added.
2912 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2917 ** New command -info-os is the MI equivalent of "info os".
2919 ** Output logs ("set logging" and related) now include MI output.
2923 ** "set use-deprecated-index-sections on|off"
2924 "show use-deprecated-index-sections on|off"
2925 Controls the use of deprecated .gdb_index sections.
2927 ** "catch load" and "catch unload" can be used to stop when a shared
2928 library is loaded or unloaded, respectively.
2930 ** "enable count" can be used to auto-disable a breakpoint after
2933 ** "info vtbl" can be used to show the virtual method tables for
2934 C++ and Java objects.
2936 ** "explore" and its sub commands "explore value" and "explore type"
2937 can be used to recursively explore values and types of
2938 expressions. These commands are available only if GDB is
2939 configured with '--with-python'.
2941 ** "info auto-load" shows status of all kinds of auto-loaded files,
2942 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2943 sequences of commands files, "info auto-load python-scripts"
2944 shows status of auto-loading Python script files,
2945 "info auto-load local-gdbinit" shows status of loading init file
2946 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2947 status of inferior specific thread debugging shared library loading.
2949 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2950 and "show auto-load-scripts" commands have been deprecated, use their
2951 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2952 and "show auto-load python-scripts" counterparts instead.
2954 ** "dprintf location,format,args..." creates a dynamic printf, which
2955 is basically a breakpoint that does a printf and immediately
2956 resumes your program's execution, so it is like a printf that you
2957 can insert dynamically at runtime instead of at compiletime.
2959 ** "set print symbol"
2961 Controls whether GDB attempts to display the symbol, if any,
2962 corresponding to addresses it prints. This defaults to "on", but
2963 you can set it to "off" to restore GDB's previous behavior.
2965 * Deprecated commands
2967 ** For the Renesas Super-H architecture, the "regs" command has been
2968 deprecated, and "info all-registers" should be used instead.
2972 Renesas RL78 rl78-*-elf
2973 HP OpenVMS ia64 ia64-hp-openvms*
2975 * GDBserver supports evaluation of breakpoint conditions. When
2976 support is advertised by GDBserver, GDB may be told to send the
2977 breakpoint conditions in bytecode form to GDBserver. GDBserver
2978 will only report the breakpoint trigger to GDB when its condition
2983 set mips compression
2984 show mips compression
2985 Select the compressed ISA encoding used in functions that have no symbol
2986 information available. The encoding can be set to either of:
2989 and is updated automatically from ELF file flags if available.
2991 set breakpoint condition-evaluation
2992 show breakpoint condition-evaluation
2993 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2994 GDBserver ("target"). Default option "auto" chooses the most efficient
2996 This option can improve debugger efficiency depending on the speed of the
3000 Disable auto-loading globally.
3003 Show auto-loading setting of all kinds of auto-loaded files.
3005 set auto-load gdb-scripts on|off
3006 show auto-load gdb-scripts
3007 Control auto-loading of GDB canned sequences of commands files.
3009 set auto-load python-scripts on|off
3010 show auto-load python-scripts
3011 Control auto-loading of Python script files.
3013 set auto-load local-gdbinit on|off
3014 show auto-load local-gdbinit
3015 Control loading of init file (.gdbinit) from current directory.
3017 set auto-load libthread-db on|off
3018 show auto-load libthread-db
3019 Control auto-loading of inferior specific thread debugging shared library.
3021 set auto-load scripts-directory <dir1>[:<dir2>...]
3022 show auto-load scripts-directory
3023 Set a list of directories from which to load auto-loaded scripts.
3024 Automatically loaded Python scripts and GDB scripts are located in one
3025 of the directories listed by this option.
3026 The delimiter (':' above) may differ according to the host platform.
3028 set auto-load safe-path <dir1>[:<dir2>...]
3029 show auto-load safe-path
3030 Set a list of directories from which it is safe to auto-load files.
3031 The delimiter (':' above) may differ according to the host platform.
3033 set debug auto-load on|off
3034 show debug auto-load
3035 Control display of debugging info for auto-loading the files above.
3037 set dprintf-style gdb|call|agent
3039 Control the way in which a dynamic printf is performed; "gdb"
3040 requests a GDB printf command, while "call" causes dprintf to call a
3041 function in the inferior. "agent" requests that the target agent
3042 (such as GDBserver) do the printing.
3044 set dprintf-function <expr>
3045 show dprintf-function
3046 set dprintf-channel <expr>
3047 show dprintf-channel
3048 Set the function and optional first argument to the call when using
3049 the "call" style of dynamic printf.
3051 set disconnected-dprintf on|off
3052 show disconnected-dprintf
3053 Control whether agent-style dynamic printfs continue to be in effect
3054 after GDB disconnects.
3056 * New configure options
3058 --with-auto-load-dir
3059 Configure default value for the 'set auto-load scripts-directory'
3060 setting above. It defaults to '$debugdir:$datadir/auto-load',
3061 $debugdir representing global debugging info directories (available
3062 via 'show debug-file-directory') and $datadir representing GDB's data
3063 directory (available via 'show data-directory').
3065 --with-auto-load-safe-path
3066 Configure default value for the 'set auto-load safe-path' setting
3067 above. It defaults to the --with-auto-load-dir setting.
3069 --without-auto-load-safe-path
3070 Set 'set auto-load safe-path' to '/', effectively disabling this
3073 * New remote packets
3075 z0/z1 conditional breakpoints extension
3077 The z0/z1 breakpoint insertion packets have been extended to carry
3078 a list of conditional expressions over to the remote stub depending on the
3079 condition evaluation mode. The use of this extension can be controlled
3080 via the "set remote conditional-breakpoints-packet" command.
3084 Specify the signals which the remote stub may pass to the debugged
3085 program without GDB involvement.
3087 * New command line options
3089 --init-command=FILE, -ix Like --command, -x but execute it
3090 before loading inferior.
3091 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3092 execute it before loading inferior.
3094 *** Changes in GDB 7.4
3096 * GDB now handles ambiguous linespecs more consistently; the existing
3097 FILE:LINE support has been expanded to other types of linespecs. A
3098 breakpoint will now be set on all matching locations in all
3099 inferiors, and locations will be added or removed according to
3102 * GDB now allows you to skip uninteresting functions and files when
3103 stepping with the "skip function" and "skip file" commands.
3105 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3106 and "show remote hardware-watchpoint-length-limit". These allows to
3107 set or show the maximum length limit (in bytes) of a remote
3108 target hardware watchpoint.
3110 This allows e.g. to use "unlimited" hardware watchpoints with the
3111 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3112 watchpoints are slower than real hardware watchpoints but are
3113 significantly faster than gdb software watchpoints.
3117 ** The register_pretty_printer function in module gdb.printing now takes
3118 an optional `replace' argument. If True, the new printer replaces any
3121 ** The "maint set python print-stack on|off" command has been
3122 deprecated and will be deleted in GDB 7.5.
3123 A new command: "set python print-stack none|full|message" has
3124 replaced it. Additionally, the default for "print-stack" is
3125 now "message", which just prints the error message without
3128 ** A prompt substitution hook (prompt_hook) is now available to the
3131 ** A new Python module, gdb.prompt has been added to the GDB Python
3132 modules library. This module provides functionality for
3133 escape sequences in prompts (used by set/show
3134 extended-prompt). These escape sequences are replaced by their
3135 corresponding value.
3137 ** Python commands and convenience-functions located in
3138 'data-directory'/python/gdb/command and
3139 'data-directory'/python/gdb/function are now automatically loaded
3142 ** Blocks now provide four new attributes. global_block and
3143 static_block will return the global and static blocks
3144 respectively. is_static and is_global are boolean attributes
3145 that indicate if the block is one of those two types.
3147 ** Symbols now provide the "type" attribute, the type of the symbol.
3149 ** The "gdb.breakpoint" function has been deprecated in favor of
3152 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3153 of a function. This class is based on the "finish" command
3154 available in the CLI.
3156 ** Type objects for struct and union types now allow access to
3157 the fields using standard Python dictionary (mapping) methods.
3158 For example, "some_type['myfield']" now works, as does
3159 "some_type.items()".
3161 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3164 ** A new function, "deep_items" has been added to the gdb.types
3165 module in the GDB Python modules library. This function returns
3166 an iterator over the fields of a struct or union type. Unlike
3167 the standard Python "iteritems" method, it will recursively traverse
3168 any anonymous fields.
3172 ** "*stopped" events can report several new "reason"s, such as
3175 ** Breakpoint changes are now notified using new async records, like
3176 "=breakpoint-modified".
3178 ** New command -ada-task-info.
3180 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3181 $sdir specifies the default system locations of shared libraries.
3182 $pdir specifies the directory where the libpthread used by the application
3185 GDB no longer looks in $sdir and $pdir after it has searched the directories
3186 mentioned in libthread-db-search-path. If you want to search those
3187 directories, they must be specified in libthread-db-search-path.
3188 The default value of libthread-db-search-path on GNU/Linux and Solaris
3189 systems is now "$sdir:$pdir".
3191 $pdir is not supported by gdbserver, it is currently ignored.
3192 $sdir is supported by gdbserver.
3194 * New configure option --with-iconv-bin.
3195 When using the internationalization support like the one in the GNU C
3196 library, GDB will invoke the "iconv" program to get a list of supported
3197 character sets. If this program lives in a non-standard location, one can
3198 use this option to specify where to find it.
3200 * When natively debugging programs on PowerPC BookE processors running
3201 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3202 watchpoints, which specify a mask in addition to an address to watch.
3203 The mask specifies that some bits of an address (the bits which are
3204 reset in the mask) should be ignored when matching the address accessed
3205 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3206 section in the user manual for more details.
3208 * The new option --once causes GDBserver to stop listening for connections once
3209 the first connection is made. The listening port used by GDBserver will
3210 become available after that.
3212 * New commands "info macros" and "alias" have been added.
3214 * New function parameters suffix @entry specifies value of function parameter
3215 at the time the function got called. Entry values are available only since
3221 "!" is now an alias of the "shell" command.
3222 Note that no space is needed between "!" and SHELL COMMAND.
3226 watch EXPRESSION mask MASK_VALUE
3227 The watch command now supports the mask argument which allows creation
3228 of masked watchpoints, if the current architecture supports this feature.
3230 info auto-load-scripts [REGEXP]
3231 This command was formerly named "maintenance print section-scripts".
3232 It is now generally useful and is no longer a maintenance-only command.
3234 info macro [-all] [--] MACRO
3235 The info macro command has new options `-all' and `--'. The first for
3236 printing all definitions of a macro. The second for explicitly specifying
3237 the end of arguments and the beginning of the macro name in case the macro
3238 name starts with a hyphen.
3240 collect[/s] EXPRESSIONS
3241 The tracepoint collect command now takes an optional modifier "/s"
3242 that directs it to dereference pointer-to-character types and
3243 collect the bytes of memory up to a zero byte. The behavior is
3244 similar to what you see when you use the regular print command on a
3245 string. An optional integer following the "/s" sets a bound on the
3246 number of bytes that will be collected.
3249 The trace start command now interprets any supplied arguments as a
3250 note to be recorded with the trace run, with an effect similar to
3251 setting the variable trace-notes.
3254 The trace stop command now interprets any arguments as a note to be
3255 mentioned along with the tstatus report that the trace was stopped
3256 with a command. The effect is similar to setting the variable
3259 * Tracepoints can now be enabled and disabled at any time after a trace
3260 experiment has been started using the standard "enable" and "disable"
3261 commands. It is now possible to start a trace experiment with no enabled
3262 tracepoints; GDB will display a warning, but will allow the experiment to
3263 begin, assuming that tracepoints will be enabled as needed while the trace
3266 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3267 locations with 4-byte instructions, when they were previously
3268 limited to locations with instructions of 5 bytes or longer.
3272 set debug dwarf2-read
3273 show debug dwarf2-read
3274 Turns on or off display of debugging messages related to reading
3275 DWARF debug info. The default is off.
3277 set debug symtab-create
3278 show debug symtab-create
3279 Turns on or off display of debugging messages related to symbol table
3280 creation. The default is off.
3283 show extended-prompt
3284 Set the GDB prompt, and allow escape sequences to be inserted to
3285 display miscellaneous information (see 'help set extended-prompt'
3286 for the list of sequences). This prompt (and any information
3287 accessed through the escape sequences) is updated every time the
3288 prompt is displayed.
3290 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3291 show print entry-values
3292 Set printing of frame argument values at function entry. In some cases
3293 GDB can determine the value of function argument which was passed by the
3294 function caller, even if the value was modified inside the called function.
3296 set debug entry-values
3297 show debug entry-values
3298 Control display of debugging info for determining frame argument values at
3299 function entry and virtual tail call frames.
3301 set basenames-may-differ
3302 show basenames-may-differ
3303 Set whether a source file may have multiple base names.
3304 (A "base name" is the name of a file with the directory part removed.
3305 Example: The base name of "/home/user/hello.c" is "hello.c".)
3306 If set, GDB will canonicalize file names (e.g., expand symlinks)
3307 before comparing them. Canonicalization is an expensive operation,
3308 but it allows the same file be known by more than one base name.
3309 If not set (the default), all source files are assumed to have just
3310 one base name, and gdb will do file name comparisons more efficiently.
3316 Set a user name and notes for the current and any future trace runs.
3317 This is useful for long-running and/or disconnected traces, to
3318 inform others (or yourself) as to who is running the trace, supply
3319 contact information, or otherwise explain what is going on.
3321 set trace-stop-notes
3322 show trace-stop-notes
3323 Set a note attached to the trace run, that is displayed when the
3324 trace has been stopped by a tstop command. This is useful for
3325 instance as an explanation, if you are stopping a trace run that was
3326 started by someone else.
3328 * New remote packets
3332 Dynamically enable a tracepoint in a started trace experiment.
3336 Dynamically disable a tracepoint in a started trace experiment.
3340 Set the user and notes of the trace run.
3344 Query the current status of a tracepoint.
3348 Query the minimum length of instruction at which a fast tracepoint may
3351 * Dcache size (number of lines) and line-size are now runtime-configurable
3352 via "set dcache line" and "set dcache line-size" commands.
3356 Texas Instruments TMS320C6x tic6x-*-*
3360 Renesas RL78 rl78-*-elf
3362 *** Changes in GDB 7.3.1
3364 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3366 *** Changes in GDB 7.3
3368 * GDB has a new command: "thread find [REGEXP]".
3369 It finds the thread id whose name, target id, or thread extra info
3370 matches the given regular expression.
3372 * The "catch syscall" command now works on mips*-linux* targets.
3374 * The -data-disassemble MI command now supports modes 2 and 3 for
3375 dumping the instruction opcodes.
3377 * New command line options
3379 -data-directory DIR Specify DIR as the "data-directory".
3380 This is mostly for testing purposes.
3382 * The "maint set python auto-load on|off" command has been renamed to
3383 "set auto-load-scripts on|off".
3385 * GDB has a new command: "set directories".
3386 It is like the "dir" command except that it replaces the
3387 source path list instead of augmenting it.
3389 * GDB now understands thread names.
3391 On GNU/Linux, "info threads" will display the thread name as set by
3392 prctl or pthread_setname_np.
3394 There is also a new command, "thread name", which can be used to
3395 assign a name internally for GDB to display.
3398 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3399 has been integrated into GDB.
3403 ** The function gdb.Write now accepts an optional keyword 'stream'.
3404 This keyword, when provided, will direct the output to either
3405 stdout, stderr, or GDB's logging output.
3407 ** Parameters can now be be sub-classed in Python, and in particular
3408 you may implement the get_set_doc and get_show_doc functions.
3409 This improves how Parameter set/show documentation is processed
3410 and allows for more dynamic content.
3412 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3413 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3414 have an is_valid method.
3416 ** Breakpoints can now be sub-classed in Python, and in particular
3417 you may implement a 'stop' function that is executed each time
3418 the inferior reaches that breakpoint.
3420 ** New function gdb.lookup_global_symbol looks up a global symbol.
3422 ** GDB values in Python are now callable if the value represents a
3423 function. For example, if 'some_value' represents a function that
3424 takes two integer parameters and returns a value, you can call
3425 that function like so:
3427 result = some_value (10,20)
3429 ** Module gdb.types has been added.
3430 It contains a collection of utilities for working with gdb.Types objects:
3431 get_basic_type, has_field, make_enum_dict.
3433 ** Module gdb.printing has been added.
3434 It contains utilities for writing and registering pretty-printers.
3435 New classes: PrettyPrinter, SubPrettyPrinter,
3436 RegexpCollectionPrettyPrinter.
3437 New function: register_pretty_printer.
3439 ** New commands "info pretty-printers", "enable pretty-printer" and
3440 "disable pretty-printer" have been added.
3442 ** gdb.parameter("directories") is now available.
3444 ** New function gdb.newest_frame returns the newest frame in the
3447 ** The gdb.InferiorThread class has a new "name" attribute. This
3448 holds the thread's name.
3450 ** Python Support for Inferior events.
3451 Python scripts can add observers to be notified of events
3452 occurring in the process being debugged.
3453 The following events are currently supported:
3454 - gdb.events.cont Continue event.
3455 - gdb.events.exited Inferior exited event.
3456 - gdb.events.stop Signal received, and Breakpoint hit events.
3460 ** GDB now puts template parameters in scope when debugging in an
3461 instantiation. For example, if you have:
3463 template<int X> int func (void) { return X; }
3465 then if you step into func<5>, "print X" will show "5". This
3466 feature requires proper debuginfo support from the compiler; it
3467 was added to GCC 4.5.
3469 ** The motion commands "next", "finish", "until", and "advance" now
3470 work better when exceptions are thrown. In particular, GDB will
3471 no longer lose control of the inferior; instead, the GDB will
3472 stop the inferior at the point at which the exception is caught.
3473 This functionality requires a change in the exception handling
3474 code that was introduced in GCC 4.5.
3476 * GDB now follows GCC's rules on accessing volatile objects when
3477 reading or writing target state during expression evaluation.
3478 One notable difference to prior behavior is that "print x = 0"
3479 no longer generates a read of x; the value of the assignment is
3480 now always taken directly from the value being assigned.
3482 * GDB now has some support for using labels in the program's source in
3483 linespecs. For instance, you can use "advance label" to continue
3484 execution to a label.
3486 * GDB now has support for reading and writing a new .gdb_index
3487 section. This section holds a fast index of DWARF debugging
3488 information and can be used to greatly speed up GDB startup and
3489 operation. See the documentation for `save gdb-index' for details.
3491 * The "watch" command now accepts an optional "-location" argument.
3492 When used, this causes GDB to watch the memory referred to by the
3493 expression. Such a watchpoint is never deleted due to it going out
3496 * GDB now supports thread debugging of core dumps on GNU/Linux.
3498 GDB now activates thread debugging using the libthread_db library
3499 when debugging GNU/Linux core dumps, similarly to when debugging
3500 live processes. As a result, when debugging a core dump file, GDB
3501 is now able to display pthread_t ids of threads. For example, "info
3502 threads" shows the same output as when debugging the process when it
3503 was live. In earlier releases, you'd see something like this:
3506 * 1 LWP 6780 main () at main.c:10
3508 While now you see this:
3511 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3513 It is also now possible to inspect TLS variables when debugging core
3516 When debugging a core dump generated on a machine other than the one
3517 used to run GDB, you may need to point GDB at the correct
3518 libthread_db library with the "set libthread-db-search-path"
3519 command. See the user manual for more details on this command.
3521 * When natively debugging programs on PowerPC BookE processors running
3522 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3523 which stop execution of the inferior whenever it executes an instruction
3524 at any address within the specified range. See the "PowerPC Embedded"
3525 section in the user manual for more details.
3527 * New features in the GDB remote stub, GDBserver
3529 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3530 and i686 LynxOS (version 5.x).
3532 ** GDBserver is now supported on Blackfin Linux.
3534 * New native configurations
3536 ia64 HP-UX ia64-*-hpux*
3540 Analog Devices, Inc. Blackfin Processor bfin-*
3542 * Ada task switching is now supported on sparc-elf targets when
3543 debugging a program using the Ravenscar Profile. For more information,
3544 see the "Tasking Support when using the Ravenscar Profile" section
3545 in the GDB user manual.
3547 * Guile support was removed.
3549 * New features in the GNU simulator
3551 ** The --map-info flag lists all known core mappings.
3553 ** CFI flashes may be simulated via the "cfi" device.
3555 *** Changes in GDB 7.2
3557 * Shared library support for remote targets by default
3559 When GDB is configured for a generic, non-OS specific target, like
3560 for example, --target=arm-eabi or one of the many *-*-elf targets,
3561 GDB now queries remote stubs for loaded shared libraries using the
3562 `qXfer:libraries:read' packet. Previously, shared library support
3563 was always disabled for such configurations.
3567 ** Argument Dependent Lookup (ADL)
3569 In C++ ADL lookup directs function search to the namespaces of its
3570 arguments even if the namespace has not been imported.
3580 Here the compiler will search for `foo' in the namespace of 'b'
3581 and find A::foo. GDB now supports this. This construct is commonly
3582 used in the Standard Template Library for operators.
3584 ** Improved User Defined Operator Support
3586 In addition to member operators, GDB now supports lookup of operators
3587 defined in a namespace and imported with a `using' directive, operators
3588 defined in the global scope, operators imported implicitly from an
3589 anonymous namespace, and the ADL operators mentioned in the previous
3591 GDB now also supports proper overload resolution for all the previously
3592 mentioned flavors of operators.
3594 ** static const class members
3596 Printing of static const class members that are initialized in the
3597 class definition has been fixed.
3599 * Windows Thread Information Block access.
3601 On Windows targets, GDB now supports displaying the Windows Thread
3602 Information Block (TIB) structure. This structure is visible either
3603 by using the new command `info w32 thread-information-block' or, by
3604 dereferencing the new convenience variable named `$_tlb', a
3605 thread-specific pointer to the TIB. This feature is also supported
3606 when remote debugging using GDBserver.
3608 * Static tracepoints
3610 Static tracepoints are calls in the user program into a tracing
3611 library. One such library is a port of the LTTng kernel tracer to
3612 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3613 When debugging with GDBserver, GDB now supports combining the GDB
3614 tracepoint machinery with such libraries. For example: the user can
3615 use GDB to probe a static tracepoint marker (a call from the user
3616 program into the tracing library) with the new "strace" command (see
3617 "New commands" below). This creates a "static tracepoint" in the
3618 breakpoint list, that can be manipulated with the same feature set
3619 as fast and regular tracepoints. E.g., collect registers, local and
3620 global variables, collect trace state variables, and define
3621 tracepoint conditions. In addition, the user can collect extra
3622 static tracepoint marker specific data, by collecting the new
3623 $_sdata internal variable. When analyzing the trace buffer, you can
3624 inspect $_sdata like any other variable available to GDB. For more
3625 information, see the "Tracepoints" chapter in GDB user manual. New
3626 remote packets have been defined to support static tracepoints, see
3627 the "New remote packets" section below.
3629 * Better reconstruction of tracepoints after disconnected tracing
3631 GDB will attempt to download the original source form of tracepoint
3632 definitions when starting a trace run, and then will upload these
3633 upon reconnection to the target, resulting in a more accurate
3634 reconstruction of the tracepoints that are in use on the target.
3638 You can now exercise direct control over the ways that GDB can
3639 affect your program. For instance, you can disallow the setting of
3640 breakpoints, so that the program can run continuously (assuming
3641 non-stop mode). In addition, the "observer" variable is available
3642 to switch all of the different controls; in observer mode, GDB
3643 cannot affect the target's behavior at all, which is useful for
3644 tasks like diagnosing live systems in the field.
3646 * The new convenience variable $_thread holds the number of the
3649 * New remote packets
3653 Return the address of the Windows Thread Information Block of a given thread.
3657 In response to several of the tracepoint packets, the target may now
3658 also respond with a number of intermediate `qRelocInsn' request
3659 packets before the final result packet, to have GDB handle
3660 relocating an instruction to execute at a different address. This
3661 is particularly useful for stubs that support fast tracepoints. GDB
3662 reports support for this feature in the qSupported packet.
3666 List static tracepoint markers in the target program.
3670 List static tracepoint markers at a given address in the target
3673 qXfer:statictrace:read
3675 Read the static trace data collected (by a `collect $_sdata'
3676 tracepoint action). The remote stub reports support for this packet
3677 to gdb's qSupported query.
3681 Send the current settings of GDB's permission flags.
3685 Send part of the source (textual) form of a tracepoint definition,
3686 which includes location, conditional, and action list.
3688 * The source command now accepts a -s option to force searching for the
3689 script in the source search path even if the script name specifies
3692 * New features in the GDB remote stub, GDBserver
3694 - GDBserver now support tracepoints (including fast tracepoints, and
3695 static tracepoints). The feature is currently supported by the
3696 i386-linux and amd64-linux builds. See the "Tracepoints support
3697 in gdbserver" section in the manual for more information.
3699 GDBserver JIT compiles the tracepoint's conditional agent
3700 expression bytecode into native code whenever possible for low
3701 overhead dynamic tracepoints conditionals. For such tracepoints,
3702 an expression that examines program state is evaluated when the
3703 tracepoint is reached, in order to determine whether to capture
3704 trace data. If the condition is simple and false, processing the
3705 tracepoint finishes very quickly and no data is gathered.
3707 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3708 for static tracepoints support.
3710 - GDBserver now supports x86_64 Windows 64-bit debugging.
3712 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3713 it understands register description.
3715 * The --batch flag now disables pagination and queries.
3717 * X86 general purpose registers
3719 GDB now supports reading/writing byte, word and double-word x86
3720 general purpose registers directly. This means you can use, say,
3721 $ah or $ax to refer, respectively, to the byte register AH and
3722 16-bit word register AX that are actually portions of the 32-bit
3723 register EAX or 64-bit register RAX.
3725 * The `commands' command now accepts a range of breakpoints to modify.
3726 A plain `commands' following a command that creates multiple
3727 breakpoints affects all the breakpoints set by that command. This
3728 applies to breakpoints set by `rbreak', and also applies when a
3729 single `break' command creates multiple breakpoints (e.g.,
3730 breakpoints on overloaded c++ functions).
3732 * The `rbreak' command now accepts a filename specification as part of
3733 its argument, limiting the functions selected by the regex to those
3734 in the specified file.
3736 * Support for remote debugging Windows and SymbianOS shared libraries
3737 from Unix hosts has been improved. Non Windows GDB builds now can
3738 understand target reported file names that follow MS-DOS based file
3739 system semantics, such as file names that include drive letters and
3740 use the backslash character as directory separator. This makes it
3741 possible to transparently use the "set sysroot" and "set
3742 solib-search-path" on Unix hosts to point as host copies of the
3743 target's shared libraries. See the new command "set
3744 target-file-system-kind" described below, and the "Commands to
3745 specify files" section in the user manual for more information.
3749 eval template, expressions...
3750 Convert the values of one or more expressions under the control
3751 of the string template to a command line, and call it.
3753 set target-file-system-kind unix|dos-based|auto
3754 show target-file-system-kind
3755 Set or show the assumed file system kind for target reported file
3758 save breakpoints <filename>
3759 Save all current breakpoint definitions to a file suitable for use
3760 in a later debugging session. To read the saved breakpoint
3761 definitions, use the `source' command.
3763 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3766 info static-tracepoint-markers
3767 Display information about static tracepoint markers in the target.
3769 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3770 Define a static tracepoint by probing a marker at the given
3771 function, line, address, or marker ID.
3775 Enable and disable observer mode.
3777 set may-write-registers on|off
3778 set may-write-memory on|off
3779 set may-insert-breakpoints on|off
3780 set may-insert-tracepoints on|off
3781 set may-insert-fast-tracepoints on|off
3782 set may-interrupt on|off
3783 Set individual permissions for GDB effects on the target. Note that
3784 some of these settings can have undesirable or surprising
3785 consequences, particularly when changed in the middle of a session.
3786 For instance, disabling the writing of memory can prevent
3787 breakpoints from being inserted, cause single-stepping to fail, or
3788 even crash your program, if you disable after breakpoints have been
3789 inserted. However, GDB should not crash.
3791 set record memory-query on|off
3792 show record memory-query
3793 Control whether to stop the inferior if memory changes caused
3794 by an instruction cannot be recorded.
3799 The disassemble command now supports "start,+length" form of two arguments.
3803 ** GDB now provides a new directory location, called the python directory,
3804 where Python scripts written for GDB can be installed. The location
3805 of that directory is <data-directory>/python, where <data-directory>
3806 is the GDB data directory. For more details, see section `Scripting
3807 GDB using Python' in the manual.
3809 ** The GDB Python API now has access to breakpoints, symbols, symbol
3810 tables, program spaces, inferiors, threads and frame's code blocks.
3811 Additionally, GDB Parameters can now be created from the API, and
3812 manipulated via set/show in the CLI.
3814 ** New functions gdb.target_charset, gdb.target_wide_charset,
3815 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3817 ** New exception gdb.GdbError.
3819 ** Pretty-printers are now also looked up in the current program space.
3821 ** Pretty-printers can now be individually enabled and disabled.
3823 ** GDB now looks for names of Python scripts to auto-load in a
3824 special section named `.debug_gdb_scripts', in addition to looking
3825 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3827 * Tracepoint actions were unified with breakpoint commands. In particular,
3828 there are no longer differences in "info break" output for breakpoints and
3829 tracepoints and the "commands" command can be used for both tracepoints and
3830 regular breakpoints.
3834 ARM Symbian arm*-*-symbianelf*
3836 * D language support.
3837 GDB now supports debugging programs written in the D programming
3840 * GDB now supports the extended ptrace interface for PowerPC which is
3841 available since Linux kernel version 2.6.34. This automatically enables
3842 any hardware breakpoints and additional hardware watchpoints available in
3843 the processor. The old ptrace interface exposes just one hardware
3844 watchpoint and no hardware breakpoints.
3846 * GDB is now able to use the Data Value Compare (DVC) register available on
3847 embedded PowerPC processors to implement in hardware simple watchpoint
3848 conditions of the form:
3850 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3852 This works in native GDB running on Linux kernels with the extended ptrace
3853 interface mentioned above.
3855 *** Changes in GDB 7.1
3859 ** Namespace Support
3861 GDB now supports importing of namespaces in C++. This enables the
3862 user to inspect variables from imported namespaces. Support for
3863 namepace aliasing has also been added. So, if a namespace is
3864 aliased in the current scope (e.g. namepace C=A; ) the user can
3865 print variables using the alias (e.g. (gdb) print C::x).
3869 All known bugs relating to the printing of virtual base class were
3870 fixed. It is now possible to call overloaded static methods using a
3875 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3876 and reinterpret_cast<> are now handled by the C++ expression parser.
3880 Xilinx MicroBlaze microblaze-*-*
3885 Xilinx MicroBlaze microblaze
3888 * Multi-program debugging.
3890 GDB now has support for multi-program (a.k.a. multi-executable or
3891 multi-exec) debugging. This allows for debugging multiple inferiors
3892 simultaneously each running a different program under the same GDB
3893 session. See "Debugging Multiple Inferiors and Programs" in the
3894 manual for more information. This implied some user visible changes
3895 in the multi-inferior support. For example, "info inferiors" now
3896 lists inferiors that are not running yet or that have exited
3897 already. See also "New commands" and "New options" below.
3899 * New tracing features
3901 GDB's tracepoint facility now includes several new features:
3903 ** Trace state variables
3905 GDB tracepoints now include support for trace state variables, which
3906 are variables managed by the target agent during a tracing
3907 experiment. They are useful for tracepoints that trigger each
3908 other, so for instance one tracepoint can count hits in a variable,
3909 and then a second tracepoint has a condition that is true when the
3910 count reaches a particular value. Trace state variables share the
3911 $-syntax of GDB convenience variables, and can appear in both
3912 tracepoint actions and condition expressions. Use the "tvariable"
3913 command to create, and "info tvariables" to view; see "Trace State
3914 Variables" in the manual for more detail.
3918 GDB now includes an option for defining fast tracepoints, which
3919 targets may implement more efficiently, such as by installing a jump
3920 into the target agent rather than a trap instruction. The resulting
3921 speedup can be by two orders of magnitude or more, although the
3922 tradeoff is that some program locations on some target architectures
3923 might not allow fast tracepoint installation, for instance if the
3924 instruction to be replaced is shorter than the jump. To request a
3925 fast tracepoint, use the "ftrace" command, with syntax identical to
3926 the regular trace command.
3928 ** Disconnected tracing
3930 It is now possible to detach GDB from the target while it is running
3931 a trace experiment, then reconnect later to see how the experiment
3932 is going. In addition, a new variable disconnected-tracing lets you
3933 tell the target agent whether to continue running a trace if the
3934 connection is lost unexpectedly.
3938 GDB now has the ability to save the trace buffer into a file, and
3939 then use that file as a target, similarly to you can do with
3940 corefiles. You can select trace frames, print data that was
3941 collected in them, and use tstatus to display the state of the
3942 tracing run at the moment that it was saved. To create a trace
3943 file, use "tsave <filename>", and to use it, do "target tfile
3946 ** Circular trace buffer
3948 You can ask the target agent to handle the trace buffer as a
3949 circular buffer, discarding the oldest trace frames to make room for
3950 newer ones, by setting circular-trace-buffer to on. This feature may
3951 not be available for all target agents.
3956 The disassemble command, when invoked with two arguments, now requires
3957 the arguments to be comma-separated.
3960 The info variables command now displays variable definitions. Files
3961 which only declare a variable are not shown.
3964 The source command is now capable of sourcing Python scripts.
3965 This feature is dependent on the debugger being build with Python
3968 Related to this enhancement is also the introduction of a new command
3969 "set script-extension" (see below).
3971 * New commands (for set/show, see "New options" below)
3973 record save [<FILENAME>]
3974 Save a file (in core file format) containing the process record
3975 execution log for replay debugging at a later time.
3977 record restore <FILENAME>
3978 Restore the process record execution log that was saved at an
3979 earlier time, for replay debugging.
3981 add-inferior [-copies <N>] [-exec <FILENAME>]
3984 clone-inferior [-copies <N>] [ID]
3985 Make a new inferior ready to execute the same program another
3986 inferior has loaded.
3991 maint info program-spaces
3992 List the program spaces loaded into GDB.
3994 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3995 show remote interrupt-sequence
3996 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3997 as the sequence to the remote target in order to interrupt the execution.
3998 Ctrl-C is a default. Some system prefers BREAK which is high level of
3999 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4000 Magic SysRq g. It is BREAK signal and character 'g'.
4002 set remote interrupt-on-connect [on | off]
4003 show remote interrupt-on-connect
4004 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4005 remote target when gdb connects to it. This is needed when you debug
4008 set remotebreak [on | off]
4010 Deprecated. Use "set/show remote interrupt-sequence" instead.
4012 tvariable $NAME [ = EXP ]
4013 Create or modify a trace state variable.
4016 List trace state variables and their values.
4018 delete tvariable $NAME ...
4019 Delete one or more trace state variables.
4022 Evaluate the given expressions without collecting anything into the
4023 trace buffer. (Valid in tracepoint actions only.)
4025 ftrace FN / FILE:LINE / *ADDR
4026 Define a fast tracepoint at the given function, line, or address.
4028 * New expression syntax
4030 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4031 GDB now parses 0b101010 identically with 42.
4035 set follow-exec-mode new|same
4036 show follow-exec-mode
4037 Control whether GDB reuses the same inferior across an exec call or
4038 creates a new one. This is useful to be able to restart the old
4039 executable after the inferior having done an exec call.
4041 set default-collect EXPR, ...
4042 show default-collect
4043 Define a list of expressions to be collected at each tracepoint.
4044 This is a useful way to ensure essential items are not overlooked,
4045 such as registers or a critical global variable.
4047 set disconnected-tracing
4048 show disconnected-tracing
4049 If set to 1, the target is instructed to continue tracing if it
4050 loses its connection to GDB. If 0, the target is to stop tracing
4053 set circular-trace-buffer
4054 show circular-trace-buffer
4055 If set to on, the target is instructed to use a circular trace buffer
4056 and discard the oldest trace frames instead of stopping the trace due
4057 to a full trace buffer. If set to off, the trace stops when the buffer
4058 fills up. Some targets may not support this.
4060 set script-extension off|soft|strict
4061 show script-extension
4062 If set to "off", the debugger does not perform any script language
4063 recognition, and all sourced files are assumed to be GDB scripts.
4064 If set to "soft" (the default), files are sourced according to
4065 filename extension, falling back to GDB scripts if the first
4067 If set to "strict", files are sourced according to filename extension.
4069 set ada trust-PAD-over-XVS on|off
4070 show ada trust-PAD-over-XVS
4071 If off, activate a workaround against a bug in the debugging information
4072 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4073 the GCC sources for more information about the GNAT encoding and
4074 PAD types in particular). It is always safe to set this option to
4075 off, but this introduces a slight performance penalty. The default
4078 * Python API Improvements
4080 ** GDB provides the new class gdb.LazyString. This is useful in
4081 some pretty-printing cases. The new method gdb.Value.lazy_string
4082 provides a simple way to create objects of this type.
4084 ** The fields returned by gdb.Type.fields now have an
4085 `is_base_class' attribute.
4087 ** The new method gdb.Type.range returns the range of an array type.
4089 ** The new method gdb.parse_and_eval can be used to parse and
4090 evaluate an expression.
4092 * New remote packets
4095 Define a trace state variable.
4098 Get the current value of a trace state variable.
4101 Set desired tracing behavior upon disconnection.
4104 Set the trace buffer to be linear or circular.
4107 Get data about the tracepoints currently in use.
4111 Process record now works correctly with hardware watchpoints.
4113 Multiple bug fixes have been made to the mips-irix port, making it
4114 much more reliable. In particular:
4115 - Debugging threaded applications is now possible again. Previously,
4116 GDB would hang while starting the program, or while waiting for
4117 the program to stop at a breakpoint.
4118 - Attaching to a running process no longer hangs.
4119 - An error occurring while loading a core file has been fixed.
4120 - Changing the value of the PC register now works again. This fixes
4121 problems observed when using the "jump" command, or when calling
4122 a function from GDB, or even when assigning a new value to $pc.
4123 - With the "finish" and "return" commands, the return value for functions
4124 returning a small array is now correctly printed.
4125 - It is now possible to break on shared library code which gets executed
4126 during a shared library init phase (code executed while executing
4127 their .init section). Previously, the breakpoint would have no effect.
4128 - GDB is now able to backtrace through the signal handler for
4129 non-threaded programs.
4131 PIE (Position Independent Executable) programs debugging is now supported.
4132 This includes debugging execution of PIC (Position Independent Code) shared
4133 libraries although for that, it should be possible to run such libraries as an
4136 *** Changes in GDB 7.0
4138 * GDB now has an interface for JIT compilation. Applications that
4139 dynamically generate code can create symbol files in memory and register
4140 them with GDB. For users, the feature should work transparently, and
4141 for JIT developers, the interface is documented in the GDB manual in the
4142 "JIT Compilation Interface" chapter.
4144 * Tracepoints may now be conditional. The syntax is as for
4145 breakpoints; either an "if" clause appended to the "trace" command,
4146 or the "condition" command is available. GDB sends the condition to
4147 the target for evaluation using the same bytecode format as is used
4148 for tracepoint actions.
4150 * The disassemble command now supports: an optional /r modifier, print the
4151 raw instructions in hex as well as in symbolic form, and an optional /m
4152 modifier to print mixed source+assembly.
4154 * Process record and replay
4156 In a architecture environment that supports ``process record and
4157 replay'', ``process record and replay'' target can record a log of
4158 the process execution, and replay it with both forward and reverse
4161 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4162 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4163 set execution-direction {forward|reverse}, for targets that support
4166 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4167 feature is available with a native GDB running on kernel version
4170 * GDB now has support for multi-byte and wide character sets on the
4171 target. Strings whose character type is wchar_t, char16_t, or
4172 char32_t are now correctly printed. GDB supports wide- and unicode-
4173 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4174 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4175 `printf'. This feature requires iconv to work properly; if your
4176 system does not have a working iconv, GDB can use GNU libiconv. See
4177 the installation instructions for more information.
4179 * GDB now supports automatic retrieval of shared library files from
4180 remote targets. To use this feature, specify a system root that begins
4181 with the `remote:' prefix, either via the `set sysroot' command or via
4182 the `--with-sysroot' configure-time option.
4184 * "info sharedlibrary" now takes an optional regex of libraries to show,
4185 and it now reports if a shared library has no debugging information.
4187 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4188 now complete on file names.
4190 * When completing in expressions, gdb will attempt to limit
4191 completions to allowable structure or union fields, where appropriate.
4192 For instance, consider:
4194 # struct example { int f1; double f2; };
4195 # struct example variable;
4198 If the user types TAB at the end of this command line, the available
4199 completions will be "f1" and "f2".
4201 * Inlined functions are now supported. They show up in backtraces, and
4202 the "step", "next", and "finish" commands handle them automatically.
4204 * GDB now supports the token-splicing (##) and stringification (#)
4205 operators when expanding macros. It also supports variable-arity
4208 * GDB now supports inspecting extra signal information, exported by
4209 the new $_siginfo convenience variable. The feature is currently
4210 implemented on linux ARM, i386 and amd64.
4212 * GDB can now display the VFP floating point registers and NEON vector
4213 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4214 can provide these registers (requires Linux 2.6.30 or later). Remote
4215 and simulator targets may also provide them.
4217 * New remote packets
4220 Search memory for a sequence of bytes.
4223 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4224 operation over reliable transport links. Use of this packet is
4225 controlled by the `set remote noack-packet' command.
4228 Kill the process with the specified process ID. Use this in preference
4229 to `k' when multiprocess protocol extensions are supported.
4232 Obtains additional operating system information
4236 Read or write additional signal information.
4238 * Removed remote protocol undocumented extension
4240 An undocumented extension to the remote protocol's `S' stop reply
4241 packet that permited the stub to pass a process id was removed.
4242 Remote servers should use the `T' stop reply packet instead.
4244 * GDB now supports multiple function calling conventions according to the
4245 DWARF-2 DW_AT_calling_convention function attribute.
4247 * The SH target utilizes the aforementioned change to distinguish between gcc
4248 and Renesas calling convention. It also adds the new CLI commands
4249 `set/show sh calling-convention'.
4251 * GDB can now read compressed debug sections, as produced by GNU gold
4252 with the --compress-debug-sections=zlib flag.
4254 * 64-bit core files are now supported on AIX.
4256 * Thread switching is now supported on Tru64.
4258 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4259 which will be allocated using malloc later in program execution.
4261 * The qXfer:libraries:read remote procotol packet now allows passing a
4262 list of section offsets.
4264 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4265 conditions handling signals delivered during attach or thread creation
4266 have also been fixed.
4268 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4269 From the user's standpoint, all unqualified instances of True and False
4270 are treated as the standard definitions, regardless of context.
4272 * GDB now parses C++ symbol and type names more flexibly. For
4275 template<typename T> class C { };
4278 GDB will now correctly handle all of:
4280 ptype C<char const *>
4281 ptype C<char const*>
4282 ptype C<const char *>
4283 ptype C<const char*>
4285 * New features in the GDB remote stub, gdbserver
4287 - The "--wrapper" command-line argument tells gdbserver to use a
4288 wrapper program to launch programs for debugging.
4290 - On PowerPC and S/390 targets, it is now possible to use a single
4291 gdbserver executable to debug both 32-bit and 64-bit programs.
4292 (This requires gdbserver itself to be built as a 64-bit executable.)
4294 - gdbserver uses the new noack protocol mode for TCP connections to
4295 reduce communications latency, if also supported and enabled in GDB.
4297 - Support for the sparc64-linux-gnu target is now included in
4300 - The amd64-linux build of gdbserver now supports debugging both
4301 32-bit and 64-bit programs.
4303 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4304 now support hardware watchpoints, and will use them automatically
4309 GDB now has support for scripting using Python. Whether this is
4310 available is determined at configure time.
4312 New GDB commands can now be written in Python.
4314 * Ada tasking support
4316 Ada tasks can now be inspected in GDB. The following commands have
4320 Print the list of Ada tasks.
4322 Print detailed information about task number N.
4324 Print the task number of the current task.
4326 Switch the context of debugging to task number N.
4328 * Support for user-defined prefixed commands. The "define" command can
4329 add new commands to existing prefixes, e.g. "target".
4331 * Multi-inferior, multi-process debugging.
4333 GDB now has generalized support for multi-inferior debugging. See
4334 "Debugging Multiple Inferiors" in the manual for more information.
4335 Although availability still depends on target support, the command
4336 set is more uniform now. The GNU/Linux specific multi-forks support
4337 has been migrated to this new framework. This implied some user
4338 visible changes; see "New commands" and also "Removed commands"
4341 * Target descriptions can now describe the target OS ABI. See the
4342 "Target Description Format" section in the user manual for more
4345 * Target descriptions can now describe "compatible" architectures
4346 to indicate that the target can execute applications for a different
4347 architecture in addition to those for the main target architecture.
4348 See the "Target Description Format" section in the user manual for
4351 * Multi-architecture debugging.
4353 GDB now includes general supports for debugging applications on
4354 hybrid systems that use more than one single processor architecture
4355 at the same time. Each such hybrid architecture still requires
4356 specific support to be added. The only hybrid architecture supported
4357 in this version of GDB is the Cell Broadband Engine.
4359 * GDB now supports integrated debugging of Cell/B.E. applications that
4360 use both the PPU and SPU architectures. To enable support for hybrid
4361 Cell/B.E. debugging, you need to configure GDB to support both the
4362 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4363 --enable-targets configure option.
4365 * Non-stop mode debugging.
4367 For some targets, GDB now supports an optional mode of operation in
4368 which you can examine stopped threads while other threads continue
4369 to execute freely. This is referred to as non-stop mode, with the
4370 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4371 section in the user manual for more information.
4373 To be able to support remote non-stop debugging, a remote stub needs
4374 to implement the non-stop mode remote protocol extensions, as
4375 described in the "Remote Non-Stop" section of the user manual. The
4376 GDB remote stub, gdbserver, has been adjusted to support these
4377 extensions on linux targets.
4379 * New commands (for set/show, see "New options" below)
4381 catch syscall [NAME(S) | NUMBER(S)]
4382 Catch system calls. Arguments, which should be names of system
4383 calls or their numbers, mean catch only those syscalls. Without
4384 arguments, every syscall will be caught. When the inferior issues
4385 any of the specified syscalls, GDB will stop and announce the system
4386 call, both when it is called and when its call returns. This
4387 feature is currently available with a native GDB running on the
4388 Linux Kernel, under the following architectures: x86, x86_64,
4389 PowerPC and PowerPC64.
4391 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4393 Search memory for a sequence of bytes.
4395 maint set python print-stack
4396 maint show python print-stack
4397 Show a stack trace when an error is encountered in a Python script.
4400 Invoke CODE by passing it to the Python interpreter.
4405 These allow macros to be defined, undefined, and listed
4409 Show operating system information about processes.
4412 List the inferiors currently under GDB's control.
4415 Switch focus to inferior number NUM.
4418 Detach from inferior number NUM.
4421 Kill inferior number NUM.
4425 set spu stop-on-load
4426 show spu stop-on-load
4427 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4429 set spu auto-flush-cache
4430 show spu auto-flush-cache
4431 Control whether to automatically flush the software-managed cache
4432 during Cell/B.E. debugging.
4434 set sh calling-convention
4435 show sh calling-convention
4436 Control the calling convention used when calling SH target functions.
4439 show debug timestamp
4440 Control display of timestamps with GDB debugging output.
4442 set disassemble-next-line
4443 show disassemble-next-line
4444 Control display of disassembled source lines or instructions when
4447 set remote noack-packet
4448 show remote noack-packet
4449 Set/show the use of remote protocol QStartNoAckMode packet. See above
4450 under "New remote packets."
4452 set remote query-attached-packet
4453 show remote query-attached-packet
4454 Control use of remote protocol `qAttached' (query-attached) packet.
4456 set remote read-siginfo-object
4457 show remote read-siginfo-object
4458 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4461 set remote write-siginfo-object
4462 show remote write-siginfo-object
4463 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4466 set remote reverse-continue
4467 show remote reverse-continue
4468 Control use of remote protocol 'bc' (reverse-continue) packet.
4470 set remote reverse-step
4471 show remote reverse-step
4472 Control use of remote protocol 'bs' (reverse-step) packet.
4474 set displaced-stepping
4475 show displaced-stepping
4476 Control displaced stepping mode. Displaced stepping is a way to
4477 single-step over breakpoints without removing them from the debuggee.
4478 Also known as "out-of-line single-stepping".
4481 show debug displaced
4482 Control display of debugging info for displaced stepping.
4484 maint set internal-error
4485 maint show internal-error
4486 Control what GDB does when an internal error is detected.
4488 maint set internal-warning
4489 maint show internal-warning
4490 Control what GDB does when an internal warning is detected.
4495 Use a wrapper program to launch programs for debugging.
4497 set multiple-symbols (all|ask|cancel)
4498 show multiple-symbols
4499 The value of this variable can be changed to adjust the debugger behavior
4500 when an expression or a breakpoint location contains an ambiguous symbol
4501 name (an overloaded function name, for instance).
4503 set breakpoint always-inserted
4504 show breakpoint always-inserted
4505 Keep breakpoints always inserted in the target, as opposed to inserting
4506 them when resuming the target, and removing them when the target stops.
4507 This option can improve debugger performance on slow remote targets.
4509 set arm fallback-mode (arm|thumb|auto)
4510 show arm fallback-mode
4511 set arm force-mode (arm|thumb|auto)
4513 These commands control how ARM GDB determines whether instructions
4514 are ARM or Thumb. The default for both settings is auto, which uses
4515 the current CPSR value for instructions without symbols; previous
4516 versions of GDB behaved as if "set arm fallback-mode arm".
4518 set disable-randomization
4519 show disable-randomization
4520 Standalone programs run with the virtual address space randomization enabled
4521 by default on some platforms. This option keeps the addresses stable across
4522 multiple debugging sessions.
4526 Control whether other threads are stopped or not when some thread hits
4531 Requests that asynchronous execution is enabled in the target, if available.
4532 In this case, it's possible to resume target in the background, and interact
4533 with GDB while the target is running. "show target-async" displays the
4534 current state of asynchronous execution of the target.
4536 set target-wide-charset
4537 show target-wide-charset
4538 The target-wide-charset is the name of the character set that GDB
4539 uses when printing characters whose type is wchar_t.
4541 set tcp auto-retry (on|off)
4543 set tcp connect-timeout
4544 show tcp connect-timeout
4545 These commands allow GDB to retry failed TCP connections to a remote stub
4546 with a specified timeout period; this is useful if the stub is launched
4547 in parallel with GDB but may not be ready to accept connections immediately.
4549 set libthread-db-search-path
4550 show libthread-db-search-path
4551 Control list of directories which GDB will search for appropriate
4554 set schedule-multiple (on|off)
4555 show schedule-multiple
4556 Allow GDB to resume all threads of all processes or only threads of
4557 the current process.
4561 Use more aggressive caching for accesses to the stack. This improves
4562 performance of remote debugging (particularly backtraces) without
4563 affecting correctness.
4565 set interactive-mode (on|off|auto)
4566 show interactive-mode
4567 Control whether GDB runs in interactive mode (on) or not (off).
4568 When in interactive mode, GDB waits for the user to answer all
4569 queries. Otherwise, GDB does not wait and assumes the default
4570 answer. When set to auto (the default), GDB determines which
4571 mode to use based on the stdin settings.
4576 For program forks, this is replaced by the new more generic `info
4577 inferiors' command. To list checkpoints, you can still use the
4578 `info checkpoints' command, which was an alias for the `info forks'
4582 Replaced by the new `inferior' command. To switch between
4583 checkpoints, you can still use the `restart' command, which was an
4584 alias for the `fork' command.
4587 This is removed, since some targets don't have a notion of
4588 processes. To switch between processes, you can still use the
4589 `inferior' command using GDB's own inferior number.
4592 For program forks, this is replaced by the new more generic `kill
4593 inferior' command. To delete a checkpoint, you can still use the
4594 `delete checkpoint' command, which was an alias for the `delete
4598 For program forks, this is replaced by the new more generic `detach
4599 inferior' command. To detach a checkpoint, you can still use the
4600 `detach checkpoint' command, which was an alias for the `detach
4603 * New native configurations
4605 x86/x86_64 Darwin i[34567]86-*-darwin*
4607 x86_64 MinGW x86_64-*-mingw*
4611 Lattice Mico32 lm32-*
4612 x86 DICOS i[34567]86-*-dicos*
4613 x86_64 DICOS x86_64-*-dicos*
4616 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4617 (mingw32ce) debugging.
4623 These commands were actually not implemented on any target.
4625 *** Changes in GDB 6.8
4627 * New native configurations
4629 NetBSD/hppa hppa*-*netbsd*
4630 Xtensa GNU/Linux xtensa*-*-linux*
4634 NetBSD/hppa hppa*-*-netbsd*
4635 Xtensa GNU/Lunux xtensa*-*-linux*
4637 * Change in command line behavior -- corefiles vs. process ids.
4639 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4640 attaching to process NUMBER fails, GDB no longer attempts to open a
4641 core file named NUMBER. Attaching to a program using the -c option
4642 is no longer supported. Instead, use the '-p' or '--pid' options.
4644 * GDB can now be built as a native debugger for debugging Windows x86
4645 (mingw32) Portable Executable (PE) programs.
4647 * Pending breakpoints no longer change their number when their address
4650 * GDB now supports breakpoints with multiple locations,
4651 including breakpoints on C++ constructors, inside C++ templates,
4652 and in inlined functions.
4654 * GDB's ability to debug optimized code has been improved. GDB more
4655 accurately identifies function bodies and lexical blocks that occupy
4656 more than one contiguous range of addresses.
4658 * Target descriptions can now describe registers for PowerPC.
4660 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4661 registers on PowerPC targets.
4663 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4664 targets even when the libthread_db library is not available.
4666 * The GDB remote stub, gdbserver, now supports the new file transfer
4667 commands (remote put, remote get, and remote delete).
4669 * The GDB remote stub, gdbserver, now supports run and attach in
4670 extended-remote mode.
4672 * hppa*64*-*-hpux11* target broken
4673 The debugger is unable to start a program and fails with the following
4674 error: "Error trying to get information about dynamic linker".
4675 The gdb-6.7 release is also affected.
4677 * GDB now supports the --enable-targets= configure option to allow
4678 building a single GDB executable that supports multiple remote
4679 target architectures.
4681 * GDB now supports debugging C and C++ programs which use the
4682 Decimal Floating Point extension. In addition, the PowerPC target
4683 now has a set of pseudo-registers to inspect decimal float values
4684 stored in two consecutive float registers.
4686 * The -break-insert MI command can optionally create pending
4689 * Improved support for debugging Ada
4690 Many improvements to the Ada language support have been made. These
4692 - Better support for Ada2005 interface types
4693 - Improved handling of arrays and slices in general
4694 - Better support for Taft-amendment types
4695 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4697 - Improved command completion in Ada
4700 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4705 set print frame-arguments (all|scalars|none)
4706 show print frame-arguments
4707 The value of this variable can be changed to control which argument
4708 values should be printed by the debugger when displaying a frame.
4713 Transfer files to and from a remote target, and delete remote files.
4720 Transfer files to and from a remote target, and delete remote files.
4722 * New remote packets
4729 Open, close, read, write, and delete files on the remote system.
4732 Attach to an existing process on the remote system, in extended-remote
4736 Run a new process on the remote system, in extended-remote mode.
4738 *** Changes in GDB 6.7
4740 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4741 bfd, libiberty and opcodes, as revealed by static analysis donated by
4742 Coverity, Inc. (http://scan.coverity.com).
4744 * When looking up multiply-defined global symbols, GDB will now prefer the
4745 symbol definition in the current shared library if it was built using the
4746 -Bsymbolic linker option.
4748 * When the Text User Interface (TUI) is not configured, GDB will now
4749 recognize the -tui command-line option and print a message that the TUI
4752 * The GDB remote stub, gdbserver, now has lower overhead for high
4753 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4755 * GDB for MIPS targets now autodetects whether a remote target provides
4756 32-bit or 64-bit register values.
4758 * Support for C++ member pointers has been improved.
4760 * GDB now understands XML target descriptions, which specify the
4761 target's overall architecture. GDB can read a description from
4762 a local file or over the remote serial protocol.
4764 * Vectors of single-byte data use a new integer type which is not
4765 automatically displayed as character or string data.
4767 * The /s format now works with the print command. It displays
4768 arrays of single-byte integers and pointers to single-byte integers
4771 * Target descriptions can now describe target-specific registers,
4772 for architectures which have implemented the support (currently
4773 only ARM, M68K, and MIPS).
4775 * GDB and the GDB remote stub, gdbserver, now support the XScale
4778 * The GDB remote stub, gdbserver, has been updated to support
4779 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4780 has been rewritten to use the standard GDB remote protocol.
4782 * GDB can now step into C++ functions which are called through thunks.
4784 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4786 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4787 layout. It also supports a TextSeg= and DataSeg= response when only
4788 segment base addresses (rather than offsets) are available.
4790 * The /i format now outputs any trailing branch delay slot instructions
4791 immediately following the last instruction within the count specified.
4793 * The GDB remote protocol "T" stop reply packet now supports a
4794 "library" response. Combined with the new "qXfer:libraries:read"
4795 packet, this response allows GDB to debug shared libraries on targets
4796 where the operating system manages the list of loaded libraries (e.g.
4797 Windows and SymbianOS).
4799 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4800 (DLLs) on Windows and Windows CE targets.
4802 * GDB now supports a faster verification that a .debug file matches its binary
4803 according to its build-id signature, if the signature is present.
4809 Enable or disable hardware flow control (RTS/CTS) on the serial port
4810 when debugging using remote targets.
4812 set mem inaccessible-by-default
4813 show mem inaccessible-by-default
4814 If the target supplies a memory map, for instance via the remote
4815 protocol's "qXfer:memory-map:read" packet, setting this variable
4816 prevents GDB from accessing memory outside the memory map. This
4817 is useful for targets with memory mapped registers or which react
4818 badly to accesses of unmapped address space.
4820 set breakpoint auto-hw
4821 show breakpoint auto-hw
4822 If the target supplies a memory map, for instance via the remote
4823 protocol's "qXfer:memory-map:read" packet, setting this variable
4824 lets GDB use hardware breakpoints automatically for memory regions
4825 where it can not use software breakpoints. This covers both the
4826 "break" command and internal breakpoints used for other commands
4827 including "next" and "finish".
4830 catch exception unhandled
4831 Stop the program execution when Ada exceptions are raised.
4834 Stop the program execution when an Ada assertion failed.
4838 Set an alternate system root for target files. This is a more
4839 general version of "set solib-absolute-prefix", which is now
4840 an alias to "set sysroot".
4843 Provide extended SPU facility status information. This set of
4844 commands is available only when debugging the Cell/B.E. SPU
4847 * New native configurations
4849 OpenBSD/sh sh*-*openbsd*
4852 unset tdesc filename
4854 Use the specified local file as an XML target description, and do
4855 not query the target for its built-in description.
4859 OpenBSD/sh sh*-*-openbsd*
4860 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4861 Toshiba Media Processor mep-elf
4863 * New remote packets
4866 Ignore the specified signals; pass them directly to the debugged program
4867 without stopping other threads or reporting them to GDB.
4869 qXfer:features:read:
4870 Read an XML target description from the target, which describes its
4875 Read or write contents of an spufs file on the target system. These
4876 packets are available only on the Cell/B.E. SPU architecture.
4878 qXfer:libraries:read:
4879 Report the loaded shared libraries. Combined with new "T" packet
4880 response, this packet allows GDB to debug shared libraries on
4881 targets where the operating system manages the list of loaded
4882 libraries (e.g. Windows and SymbianOS).
4886 Support for these obsolete configurations has been removed.
4894 i[34567]86-*-lynxos*
4895 i[34567]86-*-netware*
4896 i[34567]86-*-sco3.2v5*
4897 i[34567]86-*-sco3.2v4*
4899 i[34567]86-*-sysv4.2*
4902 i[34567]86-*-unixware2*
4903 i[34567]86-*-unixware*
4912 * Other removed features
4919 Various m68k-only ROM monitors.
4926 Various Renesas ROM monitors and debugging interfaces for SH and
4931 Support for a Macraigor serial interface to on-chip debugging.
4932 GDB does not directly support the newer parallel or USB
4937 A debug information format. The predecessor to DWARF 2 and
4938 DWARF 3, which are still supported.
4940 Support for the HP aCC compiler on HP-UX/PA-RISC
4942 SOM-encapsulated symbolic debugging information, automatic
4943 invocation of pxdb, and the aCC custom C++ ABI. This does not
4944 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4945 with aCC can still be debugged on an assembly level.
4947 MIPS ".pdr" sections
4949 A MIPS-specific format used to describe stack frame layout
4950 in debugging information.
4954 GDB could work with an older version of Guile to debug
4955 the interpreter and Scheme programs running in it.
4957 set mips stack-arg-size
4958 set mips saved-gpreg-size
4960 Use "set mips abi" to control parameter passing for MIPS.
4962 *** Changes in GDB 6.6
4967 Cell Broadband Engine SPU spu-elf
4969 * GDB can now be configured as a cross-debugger targeting native Windows
4970 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4971 running on a Windows system over TCP/IP to debug Windows programs.
4973 * The GDB remote stub, gdbserver, has been updated to support Windows and
4974 Cygwin debugging. Both single-threaded and multi-threaded programs are
4977 * The "set trust-readonly-sections" command works again. This command was
4978 broken in GDB 6.3, 6.4, and 6.5.
4980 * The "load" command now supports writing to flash memory, if the remote
4981 stub provides the required support.
4983 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4984 longer requires symbolic debug information (e.g. DWARF-2).
4989 unset substitute-path
4990 show substitute-path
4991 Manage a list of substitution rules that GDB uses to rewrite the name
4992 of the directories where the sources are located. This can be useful
4993 for instance when the sources were moved to a different location
4994 between compilation and debugging.
4998 Print each CLI command as it is executed. Each command is prefixed with
4999 a number of `+' symbols representing the nesting depth.
5000 The source command now has a `-v' option to enable the same feature.
5004 The ARM Demon monitor support (RDP protocol, "target rdp").
5006 Kernel Object Display, an embedded debugging feature which only worked with
5007 an obsolete version of Cisco IOS.
5009 The 'set download-write-size' and 'show download-write-size' commands.
5011 * New remote packets
5014 Tell a stub about GDB client features, and request remote target features.
5015 The first feature implemented is PacketSize, which allows the target to
5016 specify the size of packets it can handle - to minimize the number of
5017 packets required and improve performance when connected to a remote
5021 Fetch an OS auxilliary vector from the remote stub. This packet is a
5022 more efficient replacement for qPart:auxv:read.
5024 qXfer:memory-map:read:
5025 Fetch a memory map from the remote stub, including information about
5026 RAM, ROM, and flash memory devices.
5031 Erase and program a flash memory device.
5033 * Removed remote packets
5036 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5037 used it, and only gdbserver implemented it.
5039 *** Changes in GDB 6.5
5043 Renesas M32C/M16C m32c-elf
5045 Morpho Technologies ms1 ms1-elf
5049 init-if-undefined Initialize a convenience variable, but
5050 only if it doesn't already have a value.
5052 The following commands are presently only implemented for native GNU/Linux:
5054 checkpoint Save a snapshot of the program state.
5056 restart <n> Return the program state to a
5057 previously saved state.
5059 info checkpoints List currently saved checkpoints.
5061 delete-checkpoint <n> Delete a previously saved checkpoint.
5063 set|show detach-on-fork Tell gdb whether to detach from a newly
5064 forked process, or to keep debugging it.
5066 info forks List forks of the user program that
5067 are available to be debugged.
5069 fork <n> Switch to debugging one of several
5070 forks of the user program that are
5071 available to be debugged.
5073 delete-fork <n> Delete a fork from the list of forks
5074 that are available to be debugged (and
5075 kill the forked process).
5077 detach-fork <n> Delete a fork from the list of forks
5078 that are available to be debugged (and
5079 allow the process to continue).
5083 Morpho Technologies ms2 ms1-elf
5085 * Improved Windows host support
5087 GDB now builds as a cross debugger hosted on i686-mingw32, including
5088 native console support, and remote communications using either
5089 network sockets or serial ports.
5091 * Improved Modula-2 language support
5093 GDB can now print most types in the Modula-2 syntax. This includes:
5094 basic types, set types, record types, enumerated types, range types,
5095 pointer types and ARRAY types. Procedure var parameters are correctly
5096 printed and hexadecimal addresses and character constants are also
5097 written in the Modula-2 syntax. Best results can be obtained by using
5098 GNU Modula-2 together with the -gdwarf-2 command line option.
5102 The ARM rdi-share module.
5104 The Netware NLM debug server.
5106 *** Changes in GDB 6.4
5108 * New native configurations
5110 OpenBSD/arm arm*-*-openbsd*
5111 OpenBSD/mips64 mips64-*-openbsd*
5115 Morpho Technologies ms1 ms1-elf
5117 * New command line options
5119 --batch-silent As for --batch, but totally silent.
5120 --return-child-result The debugger will exist with the same value
5121 the child (debugged) program exited with.
5122 --eval-command COMMAND, -ex COMMAND
5123 Execute a single GDB CLI command. This may be
5124 specified multiple times and in conjunction
5125 with the --command (-x) option.
5127 * Deprecated commands removed
5129 The following commands, that were deprecated in 2000, have been
5133 set|show arm disassembly-flavor set|show arm disassembler
5134 othernames set arm disassembler
5135 set|show remotedebug set|show debug remote
5136 set|show archdebug set|show debug arch
5137 set|show eventdebug set|show debug event
5140 * New BSD user-level threads support
5142 It is now possible to debug programs using the user-level threads
5143 library on OpenBSD and FreeBSD. Currently supported (target)
5146 FreeBSD/amd64 x86_64-*-freebsd*
5147 FreeBSD/i386 i386-*-freebsd*
5148 OpenBSD/i386 i386-*-openbsd*
5150 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5151 are not yet supported.
5153 * New support for Matsushita MN10300 w/sim added
5154 (Work in progress). mn10300-elf.
5156 * REMOVED configurations and files
5158 VxWorks and the XDR protocol *-*-vxworks
5159 Motorola MCORE mcore-*-*
5160 National Semiconductor NS32000 ns32k-*-*
5162 * New "set print array-indexes" command
5164 After turning this setting "on", GDB prints the index of each element
5165 when displaying arrays. The default is "off" to preserve the previous
5168 * VAX floating point support
5170 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5172 * User-defined command support
5174 In addition to using $arg0..$arg9 for argument passing, it is now possible
5175 to use $argc to determine now many arguments have been passed. See the
5176 section on user-defined commands in the user manual for more information.
5178 *** Changes in GDB 6.3:
5180 * New command line option
5182 GDB now accepts -l followed by a number to set the timeout for remote
5185 * GDB works with GCC -feliminate-dwarf2-dups
5187 GDB now supports a more compact representation of DWARF-2 debug
5188 information using DW_FORM_ref_addr references. These are produced
5189 by GCC with the option -feliminate-dwarf2-dups and also by some
5190 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5191 to use -feliminate-dwarf2-dups.
5193 * Internationalization
5195 When supported by the host system, GDB will be built with
5196 internationalization (libintl). The task of marking up the sources is
5197 continued, we're looking forward to our first translation.
5201 Initial support for debugging programs compiled with the GNAT
5202 implementation of the Ada programming language has been integrated
5203 into GDB. In this release, support is limited to expression evaluation.
5205 * New native configurations
5207 GNU/Linux/m32r m32r-*-linux-gnu
5211 GDB's remote protocol now includes support for the 'p' packet. This
5212 packet is used to fetch individual registers from a remote inferior.
5214 * END-OF-LIFE registers[] compatibility module
5216 GDB's internal register infrastructure has been completely rewritten.
5217 The new infrastructure making possible the implementation of key new
5218 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5221 GDB 6.3 will be the last release to include the registers[]
5222 compatibility module that allowed out-of-date configurations to
5223 continue to work. This change directly impacts the following
5233 powerpc bdm protocol
5235 Unless there is activity to revive these configurations, they will be
5236 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5238 * OBSOLETE configurations and files
5240 Configurations that have been declared obsolete in this release have
5241 been commented out. Unless there is activity to revive these
5242 configurations, the next release of GDB will have their sources
5243 permanently REMOVED.
5252 *** Changes in GDB 6.2.1:
5254 * MIPS `break main; run' gave an heuristic-fence-post warning
5256 When attempting to run even a simple program, a warning about
5257 heuristic-fence-post being hit would be reported. This problem has
5260 * MIPS IRIX 'long double' crashed GDB
5262 When examining a long double variable, GDB would get a segmentation
5263 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5264 IRIX long double values).
5268 A bug in the VAX stack code was causing problems with the "next"
5269 command. This problem has been fixed.
5271 *** Changes in GDB 6.2:
5273 * Fix for ``many threads''
5275 On GNU/Linux systems that use the NPTL threads library, a program
5276 rapidly creating and deleting threads would confuse GDB leading to the
5279 ptrace: No such process.
5280 thread_db_get_info: cannot get thread info: generic error
5282 This problem has been fixed.
5284 * "-async" and "-noasync" options removed.
5286 Support for the broken "-noasync" option has been removed (it caused
5289 * New ``start'' command.
5291 This command runs the program until the begining of the main procedure.
5293 * New BSD Kernel Data Access Library (libkvm) interface
5295 Using ``target kvm'' it is now possible to debug kernel core dumps and
5296 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5297 platforms. Currently supported (native-only) configurations are:
5299 FreeBSD/amd64 x86_64-*-freebsd*
5300 FreeBSD/i386 i?86-*-freebsd*
5301 NetBSD/i386 i?86-*-netbsd*
5302 NetBSD/m68k m68*-*-netbsd*
5303 NetBSD/sparc sparc-*-netbsd*
5304 OpenBSD/amd64 x86_64-*-openbsd*
5305 OpenBSD/i386 i?86-*-openbsd*
5306 OpenBSD/m68k m68*-openbsd*
5307 OpenBSD/sparc sparc-*-openbsd*
5309 * Signal trampoline code overhauled
5311 Many generic problems with GDB's signal handling code have been fixed.
5312 These include: backtraces through non-contiguous stacks; recognition
5313 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5314 call; backtrace through a signal trampoline; step into and out of
5315 signal handlers; and single-stepping in the signal trampoline.
5317 Please note that kernel bugs are a limiting factor here. These
5318 features have been shown to work on an s390 GNU/Linux system that
5319 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5321 * Cygwin support for DWARF 2 added.
5323 * New native configurations
5325 GNU/Linux/hppa hppa*-*-linux*
5326 OpenBSD/hppa hppa*-*-openbsd*
5327 OpenBSD/m68k m68*-*-openbsd*
5328 OpenBSD/m88k m88*-*-openbsd*
5329 OpenBSD/powerpc powerpc-*-openbsd*
5330 NetBSD/vax vax-*-netbsd*
5331 OpenBSD/vax vax-*-openbsd*
5333 * END-OF-LIFE frame compatibility module
5335 GDB's internal frame infrastructure has been completely rewritten.
5336 The new infrastructure making it possible to support key new features
5337 including DWARF 2 Call Frame Information. To aid in the task of
5338 migrating old configurations to this new infrastructure, a
5339 compatibility module, that allowed old configurations to continue to
5340 work, was also included.
5342 GDB 6.2 will be the last release to include this frame compatibility
5343 module. This change directly impacts the following configurations:
5353 Unless there is activity to revive these configurations, they will be
5354 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5356 * REMOVED configurations and files
5358 Sun 3, running SunOS 3 m68*-*-sunos3*
5359 Sun 3, running SunOS 4 m68*-*-sunos4*
5360 Sun 2, running SunOS 3 m68000-*-sunos3*
5361 Sun 2, running SunOS 4 m68000-*-sunos4*
5362 Motorola 680x0 running LynxOS m68*-*-lynxos*
5363 AT&T 3b1/Unix pc m68*-att-*
5364 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5365 decstation mips-dec-* mips-little-*
5366 riscos mips-*-riscos* mips-*-sysv*
5367 sonymips mips-sony-*
5368 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5370 *** Changes in GDB 6.1.1:
5372 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5374 The TUI (Text-mode User Interface) is now built as part of a default
5375 GDB configuration. It is enabled by either selecting the TUI with the
5376 command line option "-i=tui" or by running the separate "gdbtui"
5377 program. For more information on the TUI, see the manual "Debugging
5380 * Pending breakpoint support (also included in GDB 6.1)
5382 Support has been added to allow you to specify breakpoints in shared
5383 libraries that have not yet been loaded. If a breakpoint location
5384 cannot be found, and the "breakpoint pending" option is set to auto,
5385 GDB queries you if you wish to make the breakpoint pending on a future
5386 shared-library load. If and when GDB resolves the breakpoint symbol,
5387 the pending breakpoint is removed as one or more regular breakpoints
5390 Pending breakpoints are very useful for GCJ Java debugging.
5392 * Fixed ISO-C build problems
5394 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5395 non ISO-C code that stopped them being built using a more strict ISO-C
5396 compiler (e.g., IBM's C compiler).
5398 * Fixed build problem on IRIX 5
5400 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5401 wasn't able to compile compile on an IRIX 5 system.
5403 * Added execute permission to gdb/gdbserver/configure
5405 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5406 permission. This bug would cause configure to fail on a number of
5407 systems (Solaris, IRIX). Ref: server/519.
5409 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5411 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5412 has been updated to use constant array sizes.
5414 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5416 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5417 its generated DWARF Call Frame Info. This encoding was causing GDB to
5418 panic, that panic has been fixed. Ref: gdb/1628.
5420 * Fixed a problem when examining parameters in shared library code.
5422 When examining parameters in optimized shared library code generated
5423 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5424 not available''. GDB now correctly displays the variable's value.
5426 *** Changes in GDB 6.1:
5428 * Removed --with-mmalloc
5430 Support for the mmalloc memory manager has been removed, as it
5431 conflicted with the internal gdb byte cache.
5433 * Changes in AMD64 configurations
5435 The AMD64 target now includes the %cs and %ss registers. As a result
5436 the AMD64 remote protocol has changed; this affects the floating-point
5437 and SSE registers. If you rely on those registers for your debugging,
5438 you should upgrade gdbserver on the remote side.
5440 * Revised SPARC target
5442 The SPARC target has been completely revised, incorporating the
5443 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5444 support for LynxOS and SunOS 4 has been dropped. Calling functions
5445 from within GDB on operating systems with a non-executable stack
5446 (Solaris, OpenBSD) now works.
5450 GDB has a new C++ demangler which does a better job on the mangled
5451 names generated by current versions of g++. It also runs faster, so
5452 with this and other changes gdb should now start faster on large C++
5455 * DWARF 2 Location Expressions
5457 GDB support for location expressions has been extended to support function
5458 arguments and frame bases. Older versions of GDB could crash when they
5461 * C++ nested types and namespaces
5463 GDB's support for nested types and namespaces in C++ has been
5464 improved, especially if you use the DWARF 2 debugging format. (This
5465 is the default for recent versions of GCC on most platforms.)
5466 Specifically, if you have a class "Inner" defined within a class or
5467 namespace "Outer", then GDB realizes that the class's name is
5468 "Outer::Inner", not simply "Inner". This should greatly reduce the
5469 frequency of complaints about not finding RTTI symbols. In addition,
5470 if you are stopped at inside of a function defined within a namespace,
5471 GDB modifies its name lookup accordingly.
5473 * New native configurations
5475 NetBSD/amd64 x86_64-*-netbsd*
5476 OpenBSD/amd64 x86_64-*-openbsd*
5477 OpenBSD/alpha alpha*-*-openbsd*
5478 OpenBSD/sparc sparc-*-openbsd*
5479 OpenBSD/sparc64 sparc64-*-openbsd*
5481 * New debugging protocols
5483 M32R with SDI protocol m32r-*-elf*
5485 * "set prompt-escape-char" command deleted.
5487 The command "set prompt-escape-char" has been deleted. This command,
5488 and its very obscure effet on GDB's prompt, was never documented,
5489 tested, nor mentioned in the NEWS file.
5491 * OBSOLETE configurations and files
5493 Configurations that have been declared obsolete in this release have
5494 been commented out. Unless there is activity to revive these
5495 configurations, the next release of GDB will have their sources
5496 permanently REMOVED.
5498 Sun 3, running SunOS 3 m68*-*-sunos3*
5499 Sun 3, running SunOS 4 m68*-*-sunos4*
5500 Sun 2, running SunOS 3 m68000-*-sunos3*
5501 Sun 2, running SunOS 4 m68000-*-sunos4*
5502 Motorola 680x0 running LynxOS m68*-*-lynxos*
5503 AT&T 3b1/Unix pc m68*-att-*
5504 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5505 decstation mips-dec-* mips-little-*
5506 riscos mips-*-riscos* mips-*-sysv*
5507 sonymips mips-sony-*
5508 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5510 * REMOVED configurations and files
5512 SGI Irix-4.x mips-sgi-irix4 or iris4
5513 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5514 Z8000 simulator z8k-zilog-none or z8ksim
5515 Matsushita MN10200 w/simulator mn10200-*-*
5516 H8/500 simulator h8500-hitachi-hms or h8500hms
5517 HP/PA running BSD hppa*-*-bsd*
5518 HP/PA running OSF/1 hppa*-*-osf*
5519 HP/PA Pro target hppa*-*-pro*
5520 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5521 386BSD i[3456]86-*-bsd*
5522 Sequent family i[3456]86-sequent-sysv4*
5523 i[3456]86-sequent-sysv*
5524 i[3456]86-sequent-bsd*
5525 SPARC running LynxOS sparc-*-lynxos*
5526 SPARC running SunOS 4 sparc-*-sunos4*
5527 Tsqware Sparclet sparclet-*-*
5528 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5530 *** Changes in GDB 6.0:
5534 Support for debugging the Objective-C programming language has been
5535 integrated into GDB.
5537 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5539 DWARF 2's Call Frame Information makes available compiler generated
5540 information that more exactly describes the program's run-time stack.
5541 By using this information, GDB is able to provide more robust stack
5544 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5545 have been updated to use a new backtrace mechanism which includes
5546 DWARF 2 CFI support.
5550 GDB's remote protocol has been extended to include support for hosted
5551 file I/O (where the remote target uses GDB's file system). See GDB's
5552 remote protocol documentation for details.
5554 * All targets using the new architecture framework.
5556 All of GDB's targets have been updated to use the new internal
5557 architecture framework. The way is now open for future GDB releases
5558 to include cross-architecture native debugging support (i386 on amd64,
5561 * GNU/Linux's Thread Local Storage (TLS)
5563 GDB now includes support for for the GNU/Linux implementation of
5564 per-thread variables.
5566 * GNU/Linux's Native POSIX Thread Library (NPTL)
5568 GDB's thread code has been updated to work with either the new
5569 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5571 * Separate debug info.
5573 GDB, in conjunction with BINUTILS, now supports a mechanism for
5574 automatically loading debug information from a separate file. Instead
5575 of shipping full debug and non-debug versions of system libraries,
5576 system integrators can now instead ship just the stripped libraries
5577 and optional debug files.
5579 * DWARF 2 Location Expressions
5581 DWARF 2 Location Expressions allow the compiler to more completely
5582 describe the location of variables (even in optimized code) to the
5585 GDB now includes preliminary support for location expressions (support
5586 for DW_OP_piece is still missing).
5590 A number of long standing bugs that caused GDB to die while starting a
5591 Java application have been fixed. GDB's Java support is now
5592 considered "useable".
5594 * GNU/Linux support for fork, vfork, and exec.
5596 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5597 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5600 * GDB supports logging output to a file
5602 There are two new commands, "set logging" and "show logging", which can be
5603 used to capture GDB's output to a file.
5605 * The meaning of "detach" has changed for gdbserver
5607 The "detach" command will now resume the application, as documented. To
5608 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5611 * d10v, m68hc11 `regs' command deprecated
5613 The `info registers' command has been updated so that it displays the
5614 registers using a format identical to the old `regs' command.
5618 A new command, "maint set profile on/off", has been added. This command can
5619 be used to enable or disable profiling while running GDB, to profile a
5620 session or a set of commands. In addition there is a new configure switch,
5621 "--enable-profiling", which will cause GDB to be compiled with profiling
5622 data, for more informative profiling results.
5624 * Default MI syntax changed to "mi2".
5626 The default MI (machine interface) syntax, enabled by the command line
5627 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5628 "mi1", can be enabled by specifying the option "-i=mi1".
5630 Support for the original "mi0" syntax (included in GDB 5.0) has been
5633 Fix for gdb/192: removed extraneous space when displaying frame level.
5634 Fix for gdb/672: update changelist is now output in mi list format.
5635 Fix for gdb/702: a -var-assign that updates the value now shows up
5636 in a subsequent -var-update.
5638 * New native configurations.
5640 FreeBSD/amd64 x86_64-*-freebsd*
5642 * Multi-arched targets.
5644 HP/PA HPUX11 hppa*-*-hpux*
5645 Renesas M32R/D w/simulator m32r-*-elf*
5647 * OBSOLETE configurations and files
5649 Configurations that have been declared obsolete in this release have
5650 been commented out. Unless there is activity to revive these
5651 configurations, the next release of GDB will have their sources
5652 permanently REMOVED.
5654 Z8000 simulator z8k-zilog-none or z8ksim
5655 Matsushita MN10200 w/simulator mn10200-*-*
5656 H8/500 simulator h8500-hitachi-hms or h8500hms
5657 HP/PA running BSD hppa*-*-bsd*
5658 HP/PA running OSF/1 hppa*-*-osf*
5659 HP/PA Pro target hppa*-*-pro*
5660 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5661 Sequent family i[3456]86-sequent-sysv4*
5662 i[3456]86-sequent-sysv*
5663 i[3456]86-sequent-bsd*
5664 Tsqware Sparclet sparclet-*-*
5665 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5667 * REMOVED configurations and files
5670 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5671 IBM AIX PS/2 i[3456]86-*-aix
5672 i386 running Mach 3.0 i[3456]86-*-mach3*
5673 i386 running Mach i[3456]86-*-mach*
5674 i386 running OSF/1 i[3456]86-*osf1mk*
5675 HP/Apollo 68k Family m68*-apollo*-sysv*,
5677 m68*-hp-bsd*, m68*-hp-hpux*
5678 Argonaut Risc Chip (ARC) arc-*-*
5679 Mitsubishi D30V d30v-*-*
5680 Fujitsu FR30 fr30-*-elf*
5681 OS/9000 i[34]86-*-os9k
5682 I960 with MON960 i960-*-coff
5684 * MIPS $fp behavior changed
5686 The convenience variable $fp, for the MIPS, now consistently returns
5687 the address of the current frame's base. Previously, depending on the
5688 context, $fp could refer to either $sp or the current frame's base
5689 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5690 The GNU Source-Level Debugger''.
5692 *** Changes in GDB 5.3:
5694 * GNU/Linux shared library multi-threaded performance improved.
5696 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5697 `/proc', in preference to `ptrace' for memory reads. This may result
5698 in an improvement in the start-up time of multi-threaded, shared
5699 library applications when run under GDB. One GDB user writes: ``loads
5700 shared libs like mad''.
5702 * ``gdbserver'' now supports multi-threaded applications on some targets
5704 Support for debugging multi-threaded applications which use
5705 the GNU/Linux LinuxThreads package has been added for
5706 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5707 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5709 * GDB now supports C/C++ preprocessor macros.
5711 GDB now expands preprocessor macro invocations in C/C++ expressions,
5712 and provides various commands for showing macro definitions and how
5715 The new command `macro expand EXPRESSION' expands any macro
5716 invocations in expression, and shows the result.
5718 The new command `show macro MACRO-NAME' shows the definition of the
5719 macro named MACRO-NAME, and where it was defined.
5721 Most compilers don't include information about macros in the debugging
5722 information by default. In GCC 3.1, for example, you need to compile
5723 your program with the options `-gdwarf-2 -g3'. If the macro
5724 information is present in the executable, GDB will read it.
5726 * Multi-arched targets.
5728 DEC Alpha (partial) alpha*-*-*
5729 DEC VAX (partial) vax-*-*
5731 National Semiconductor NS32000 (partial) ns32k-*-*
5732 Motorola 68000 (partial) m68k-*-*
5733 Motorola MCORE mcore-*-*
5737 Fujitsu FRV architecture added by Red Hat frv*-*-*
5740 * New native configurations
5742 Alpha NetBSD alpha*-*-netbsd*
5743 SH NetBSD sh*-*-netbsdelf*
5744 MIPS NetBSD mips*-*-netbsd*
5745 UltraSPARC NetBSD sparc64-*-netbsd*
5747 * OBSOLETE configurations and files
5749 Configurations that have been declared obsolete in this release have
5750 been commented out. Unless there is activity to revive these
5751 configurations, the next release of GDB will have their sources
5752 permanently REMOVED.
5754 Mitsubishi D30V d30v-*-*
5755 OS/9000 i[34]86-*-os9k
5756 IBM AIX PS/2 i[3456]86-*-aix
5757 Fujitsu FR30 fr30-*-elf*
5758 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5759 Argonaut Risc Chip (ARC) arc-*-*
5760 i386 running Mach 3.0 i[3456]86-*-mach3*
5761 i386 running Mach i[3456]86-*-mach*
5762 i386 running OSF/1 i[3456]86-*osf1mk*
5763 HP/Apollo 68k Family m68*-apollo*-sysv*,
5765 m68*-hp-bsd*, m68*-hp-hpux*
5766 I960 with MON960 i960-*-coff
5768 * OBSOLETE languages
5770 CHILL, a Pascal like language used by telecommunications companies.
5772 * REMOVED configurations and files
5774 AMD 29k family via UDI a29k-amd-udi, udi29k
5775 A29K VxWorks a29k-*-vxworks
5776 AMD 29000 embedded, using EBMON a29k-none-none
5777 AMD 29000 embedded with COFF a29k-none-coff
5778 AMD 29000 embedded with a.out a29k-none-aout
5780 testsuite/gdb.hp/gdb.threads-hp/ directory
5782 * New command "set max-user-call-depth <nnn>"
5784 This command allows the user to limit the call depth of user-defined
5785 commands. The default is 1024.
5787 * Changes in FreeBSD/i386 native debugging.
5789 Support for the "generate-core-file" has been added.
5791 * New commands "dump", "append", and "restore".
5793 These commands allow data to be copied from target memory
5794 to a bfd-format or binary file (dump and append), and back
5795 from a file into memory (restore).
5797 * Improved "next/step" support on multi-processor Alpha Tru64.
5799 The previous single-step mechanism could cause unpredictable problems,
5800 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5801 of a software single-step mechanism prevents this.
5803 *** Changes in GDB 5.2.1:
5811 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5812 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5813 Fix, by Joel Brobecker imported from mainline.
5815 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5816 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5817 Fix, by Fred Fish, imported from mainline.
5819 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5820 Surprisingly enough, it works now.
5821 By Michal Ludvig, imported from mainline.
5823 i386 hardware watchpoint support:
5824 avoid misses on second run for some targets.
5825 By Pierre Muller, imported from mainline.
5827 *** Changes in GDB 5.2:
5829 * New command "set trust-readonly-sections on[off]".
5831 This command is a hint that tells gdb that read-only sections
5832 really are read-only (ie. that their contents will not change).
5833 In this mode, gdb will go to the object file rather than the
5834 target to read memory from read-only sections (such as ".text").
5835 This can be a significant performance improvement on some
5836 (notably embedded) targets.
5838 * New command "generate-core-file" (or "gcore").
5840 This new gdb command allows the user to drop a core file of the child
5841 process state at any time. So far it's been implemented only for
5842 GNU/Linux and Solaris, but should be relatively easily ported to other
5843 hosts. Argument is core file name (defaults to core.<pid>).
5845 * New command line option
5847 GDB now accepts --pid or -p followed by a process id.
5849 * Change in command line behavior -- corefiles vs. process ids.
5851 There is a subtle behavior in the way in which GDB handles
5852 command line arguments. The first non-flag argument is always
5853 a program to debug, but the second non-flag argument may either
5854 be a corefile or a process id. Previously, GDB would attempt to
5855 open the second argument as a corefile, and if that failed, would
5856 issue a superfluous error message and then attempt to attach it as
5857 a process. Now, if the second argument begins with a non-digit,
5858 it will be treated as a corefile. If it begins with a digit,
5859 GDB will attempt to attach it as a process, and if no such process
5860 is found, will then attempt to open it as a corefile.
5862 * Changes in ARM configurations.
5864 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5865 configuration is fully multi-arch.
5867 * New native configurations
5869 ARM NetBSD arm*-*-netbsd*
5870 x86 OpenBSD i[3456]86-*-openbsd*
5871 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5872 Sparc64 running FreeBSD sparc64-*-freebsd*
5876 Sanyo XStormy16 xstormy16-elf
5878 * OBSOLETE configurations and files
5880 Configurations that have been declared obsolete in this release have
5881 been commented out. Unless there is activity to revive these
5882 configurations, the next release of GDB will have their sources
5883 permanently REMOVED.
5885 AMD 29k family via UDI a29k-amd-udi, udi29k
5886 A29K VxWorks a29k-*-vxworks
5887 AMD 29000 embedded, using EBMON a29k-none-none
5888 AMD 29000 embedded with COFF a29k-none-coff
5889 AMD 29000 embedded with a.out a29k-none-aout
5891 testsuite/gdb.hp/gdb.threads-hp/ directory
5893 * REMOVED configurations and files
5895 TI TMS320C80 tic80-*-*
5897 PowerPC Solaris powerpcle-*-solaris*
5898 PowerPC Windows NT powerpcle-*-cygwin32
5899 PowerPC Netware powerpc-*-netware*
5900 Harris/CXUX m88k m88*-harris-cxux*
5901 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5902 ns32k-utek-sysv* ns32k-utek-*
5903 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5904 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5905 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5906 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5907 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5909 * Changes to command line processing
5911 The new `--args' feature can be used to specify command-line arguments
5912 for the inferior from gdb's command line.
5914 * Changes to key bindings
5916 There is a new `operate-and-get-next' function bound to `C-o'.
5918 *** Changes in GDB 5.1.1
5920 Fix compile problem on DJGPP.
5922 Fix a problem with floating-point registers on the i386 being
5925 Fix to stop GDB crashing on .debug_str debug info.
5927 Numerous documentation fixes.
5929 Numerous testsuite fixes.
5931 *** Changes in GDB 5.1:
5933 * New native configurations
5935 Alpha FreeBSD alpha*-*-freebsd*
5936 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5937 MIPS GNU/Linux mips*-*-linux*
5938 MIPS SGI Irix 6.x mips*-sgi-irix6*
5939 ia64 AIX ia64-*-aix*
5940 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5944 Motorola 68HC11 and 68HC12 m68hc11-elf
5946 UltraSparc running GNU/Linux sparc64-*-linux*
5948 * OBSOLETE configurations and files
5950 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5951 Harris/CXUX m88k m88*-harris-cxux*
5952 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5953 ns32k-utek-sysv* ns32k-utek-*
5954 TI TMS320C80 tic80-*-*
5956 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5957 PowerPC Solaris powerpcle-*-solaris*
5958 PowerPC Windows NT powerpcle-*-cygwin32
5959 PowerPC Netware powerpc-*-netware*
5960 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5961 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5962 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5963 Apple Macintosh (MPW) host N/A
5965 stuff.c (Program to stuff files into a specially prepared space in kdb)
5966 kdb-start.c (Main loop for the standalone kernel debugger)
5968 Configurations that have been declared obsolete in this release have
5969 been commented out. Unless there is activity to revive these
5970 configurations, the next release of GDB will have their sources
5971 permanently REMOVED.
5973 * REMOVED configurations and files
5975 Altos 3068 m68*-altos-*
5976 Convex c1-*-*, c2-*-*
5978 ARM RISCix arm-*-* (as host)
5982 * GDB has been converted to ISO C.
5984 GDB's source code has been converted to ISO C. In particular, the
5985 sources are fully protoized, and rely on standard headers being
5990 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5992 * The MI enabled by default.
5994 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5995 revised and enabled by default. Packages which use GDB as a debugging
5996 engine behind a UI or another front end are encouraged to switch to
5997 using the GDB/MI interface, instead of the old annotations interface
5998 which is now deprecated.
6000 * Support for debugging Pascal programs.
6002 GDB now includes support for debugging Pascal programs. The following
6003 main features are supported:
6005 - Pascal-specific data types such as sets;
6007 - automatic recognition of Pascal sources based on file-name
6010 - Pascal-style display of data types, variables, and functions;
6012 - a Pascal expression parser.
6014 However, some important features are not yet supported.
6016 - Pascal string operations are not supported at all;
6018 - there are some problems with boolean types;
6020 - Pascal type hexadecimal constants are not supported
6021 because they conflict with the internal variables format;
6023 - support for Pascal objects and classes is not full yet;
6025 - unlike Pascal, GDB is case-sensitive for symbol names.
6027 * Changes in completion.
6029 Commands such as `shell', `run' and `set args', which pass arguments
6030 to inferior programs, now complete on file names, similar to what
6031 users expect at the shell prompt.
6033 Commands which accept locations, such as `disassemble', `print',
6034 `breakpoint', `until', etc. now complete on filenames as well as
6035 program symbols. Thus, if you type "break foob TAB", and the source
6036 files linked into the programs include `foobar.c', that file name will
6037 be one of the candidates for completion. However, file names are not
6038 considered for completion after you typed a colon that delimits a file
6039 name from a name of a function in that file, as in "break foo.c:bar".
6041 `set demangle-style' completes on available demangling styles.
6043 * New platform-independent commands:
6045 It is now possible to define a post-hook for a command as well as a
6046 hook that runs before the command. For more details, see the
6047 documentation of `hookpost' in the GDB manual.
6049 * Changes in GNU/Linux native debugging.
6051 Support for debugging multi-threaded programs has been completely
6052 revised for all platforms except m68k and sparc. You can now debug as
6053 many threads as your system allows you to have.
6055 Attach/detach is supported for multi-threaded programs.
6057 Support for SSE registers was added for x86. This doesn't work for
6058 multi-threaded programs though.
6060 * Changes in MIPS configurations.
6062 Multi-arch support is enabled for all MIPS configurations.
6064 GDB can now be built as native debugger on SGI Irix 6.x systems for
6065 debugging n32 executables. (Debugging 64-bit executables is not yet
6068 * Unified support for hardware watchpoints in all x86 configurations.
6070 Most (if not all) native x86 configurations support hardware-assisted
6071 breakpoints and watchpoints in a unified manner. This support
6072 implements debug register sharing between watchpoints, which allows to
6073 put a virtually infinite number of watchpoints on the same address,
6074 and also supports watching regions up to 16 bytes with several debug
6077 The new maintenance command `maintenance show-debug-regs' toggles
6078 debugging print-outs in functions that insert, remove, and test
6079 watchpoints and hardware breakpoints.
6081 * Changes in the DJGPP native configuration.
6083 New command ``info dos sysinfo'' displays assorted information about
6084 the CPU, OS, memory, and DPMI server.
6086 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6087 display information about segment descriptors stored in GDT, LDT, and
6090 New commands ``info dos pde'' and ``info dos pte'' display entries
6091 from Page Directory and Page Tables (for now works with CWSDPMI only).
6092 New command ``info dos address-pte'' displays the Page Table entry for
6093 a given linear address.
6095 GDB can now pass command lines longer than 126 characters to the
6096 program being debugged (requires an update to the libdbg.a library
6097 which is part of the DJGPP development kit).
6099 DWARF2 debug info is now supported.
6101 It is now possible to `step' and `next' through calls to `longjmp'.
6103 * Changes in documentation.
6105 All GDB documentation was converted to GFDL, the GNU Free
6106 Documentation License.
6108 Tracepoints-related commands are now fully documented in the GDB
6111 TUI, the Text-mode User Interface, is now documented in the manual.
6113 Tracepoints-related commands are now fully documented in the GDB
6116 The "GDB Internals" manual now has an index. It also includes
6117 documentation of `ui_out' functions, GDB coding standards, x86
6118 hardware watchpoints, and memory region attributes.
6120 * GDB's version number moved to ``version.in''
6122 The Makefile variable VERSION has been replaced by the file
6123 ``version.in''. People creating GDB distributions should update the
6124 contents of this file.
6128 GUD support is now a standard part of the EMACS distribution.
6130 *** Changes in GDB 5.0:
6132 * Improved support for debugging FP programs on x86 targets
6134 Unified and much-improved support for debugging floating-point
6135 programs on all x86 targets. In particular, ``info float'' now
6136 displays the FP registers in the same format on all x86 targets, with
6137 greater level of detail.
6139 * Improvements and bugfixes in hardware-assisted watchpoints
6141 It is now possible to watch array elements, struct members, and
6142 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6143 on x86 targets no longer erroneously trigger when the address is
6146 * Improvements in the native DJGPP version of GDB
6148 The distribution now includes all the scripts and auxiliary files
6149 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6150 machines ``out of the box''.
6152 The DJGPP version can now debug programs that use signals. It is
6153 possible to catch signals that happened in the debuggee, deliver
6154 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6155 would kill the program being debugged.) Programs that hook hardware
6156 interrupts (keyboard, timer, etc.) can also be debugged.
6158 It is now possible to debug DJGPP programs that redirect their
6159 standard handles or switch them to raw (as opposed to cooked) mode, or
6160 even close them. The command ``run < foo > bar'' works as expected,
6161 and ``info terminal'' reports useful information about the debuggee's
6162 terminal, including raw/cooked mode, redirection, etc.
6164 The DJGPP version now uses termios functions for console I/O, which
6165 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6168 DOS-style file names with drive letters are now fully supported by
6171 It is now possible to debug DJGPP programs that switch their working
6172 directory. It is also possible to rerun the debuggee any number of
6173 times without restarting GDB; thus, you can use the same setup,
6174 breakpoints, etc. for many debugging sessions.
6176 * New native configurations
6178 ARM GNU/Linux arm*-*-linux*
6179 PowerPC GNU/Linux powerpc-*-linux*
6183 Motorola MCore mcore-*-*
6184 x86 VxWorks i[3456]86-*-vxworks*
6185 PowerPC VxWorks powerpc-*-vxworks*
6186 TI TMS320C80 tic80-*-*
6188 * OBSOLETE configurations
6190 Altos 3068 m68*-altos-*
6191 Convex c1-*-*, c2-*-*
6193 ARM RISCix arm-*-* (as host)
6196 Configurations that have been declared obsolete will be commented out,
6197 but the code will be left in place. If there is no activity to revive
6198 these configurations before the next release of GDB, the sources will
6199 be permanently REMOVED.
6201 * Gould support removed
6203 Support for the Gould PowerNode and NP1 has been removed.
6205 * New features for SVR4
6207 On SVR4 native platforms (such as Solaris), if you attach to a process
6208 without first loading a symbol file, GDB will now attempt to locate and
6209 load symbols from the running process's executable file.
6211 * Many C++ enhancements
6213 C++ support has been greatly improved. Overload resolution now works properly
6214 in almost all cases. RTTI support is on the way.
6216 * Remote targets can connect to a sub-program
6218 A popen(3) style serial-device has been added. This device starts a
6219 sub-process (such as a stand-alone simulator) and then communicates
6220 with that. The sub-program to run is specified using the syntax
6221 ``|<program> <args>'' vis:
6223 (gdb) set remotedebug 1
6224 (gdb) target extended-remote |mn10300-elf-sim program-args
6226 * MIPS 64 remote protocol
6228 A long standing bug in the mips64 remote protocol where by GDB
6229 expected certain 32 bit registers (ex SR) to be transfered as 32
6230 instead of 64 bits has been fixed.
6232 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6233 added to provide backward compatibility with older versions of GDB.
6235 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6237 The command ``set remotebinarydownload'' command has been replaced by
6238 ``set remote X-packet''. Other commands in ``set remote'' family
6239 include ``set remote P-packet''.
6241 * Breakpoint commands accept ranges.
6243 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6244 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6245 ``tracepoint passcount'' also accepts a range of tracepoints.
6247 * ``apropos'' command added.
6249 The ``apropos'' command searches through command names and
6250 documentation strings, printing out matches, making it much easier to
6251 try to find a command that does what you are looking for.
6255 A new machine oriented interface (MI) has been added to GDB. This
6256 interface is designed for debug environments running GDB as a separate
6257 process. This is part of the long term libGDB project. See the
6258 "GDB/MI" chapter of the GDB manual for further information. It can be
6259 enabled by configuring with:
6261 .../configure --enable-gdbmi
6263 *** Changes in GDB-4.18:
6265 * New native configurations
6267 HP-UX 10.20 hppa*-*-hpux10.20
6268 HP-UX 11.x hppa*-*-hpux11.0*
6269 M68K GNU/Linux m68*-*-linux*
6273 Fujitsu FR30 fr30-*-elf*
6274 Intel StrongARM strongarm-*-*
6275 Mitsubishi D30V d30v-*-*
6277 * OBSOLETE configurations
6279 Gould PowerNode, NP1 np1-*-*, pn-*-*
6281 Configurations that have been declared obsolete will be commented out,
6282 but the code will be left in place. If there is no activity to revive
6283 these configurations before the next release of GDB, the sources will
6284 be permanently REMOVED.
6288 As a compatibility experiment, GDB's source files buildsym.h and
6289 buildsym.c have been converted to pure standard C, no longer
6290 containing any K&R compatibility code. We believe that all systems in
6291 use today either come with a standard C compiler, or have a GCC port
6292 available. If this is not true, please report the affected
6293 configuration to bug-gdb@gnu.org immediately. See the README file for
6294 information about getting a standard C compiler if you don't have one
6299 GDB now uses readline 2.2.
6301 * set extension-language
6303 You can now control the mapping between filename extensions and source
6304 languages by using the `set extension-language' command. For instance,
6305 you can ask GDB to treat .c files as C++ by saying
6306 set extension-language .c c++
6307 The command `info extensions' lists all of the recognized extensions
6308 and their associated languages.
6310 * Setting processor type for PowerPC and RS/6000
6312 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6313 you can use the `set processor' command to specify what variant of the
6314 PowerPC family you are debugging. The command
6318 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6319 following PowerPC and RS6000 variants:
6321 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6322 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6324 403GC IBM PowerPC 403GC
6325 505 Motorola PowerPC 505
6326 860 Motorola PowerPC 860 or 850
6327 601 Motorola PowerPC 601
6328 602 Motorola PowerPC 602
6329 603 Motorola/IBM PowerPC 603 or 603e
6330 604 Motorola PowerPC 604 or 604e
6331 750 Motorola/IBM PowerPC 750 or 750
6333 At the moment, this command just tells GDB what to name the
6334 special-purpose processor registers. Since almost all the affected
6335 registers are inaccessible to user-level programs, this command is
6336 only useful for remote debugging in its present form.
6340 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6341 more extensive support for HP-UX. Added features include shared
6342 library support, kernel threads and hardware watchpoints for 11.00,
6343 support for HP's ANSI C and C++ compilers, and a compatibility mode
6344 for xdb and dbx commands.
6348 HP's donation includes the new concept of catchpoints, which is a
6349 generalization of the old catch command. On HP-UX, it is now possible
6350 to catch exec, fork, and vfork, as well as library loading.
6352 This means that the existing catch command has changed; its first
6353 argument now specifies the type of catch to be set up. See the
6354 output of "help catch" for a list of catchpoint types.
6356 * Debugging across forks
6358 On HP-UX, you can choose which process to debug when a fork() happens
6363 HP has donated a curses-based terminal user interface (TUI). To get
6364 it, build with --enable-tui. Although this can be enabled for any
6365 configuration, at present it only works for native HP debugging.
6367 * GDB remote protocol additions
6369 A new protocol packet 'X' that writes binary data is now available.
6370 Default behavior is to try 'X', then drop back to 'M' if the stub
6371 fails to respond. The settable variable `remotebinarydownload'
6372 allows explicit control over the use of 'X'.
6374 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6375 full 64-bit address. The command
6377 set remoteaddresssize 32
6379 can be used to revert to the old behaviour. For existing remote stubs
6380 the change should not be noticed, as the additional address information
6383 In order to assist in debugging stubs, you may use the maintenance
6384 command `packet' to send any text string to the stub. For instance,
6386 maint packet heythere
6388 sends the packet "$heythere#<checksum>". Note that it is very easy to
6389 disrupt a debugging session by sending the wrong packet at the wrong
6392 The compare-sections command allows you to compare section data on the
6393 target to what is in the executable file without uploading or
6394 downloading, by comparing CRC checksums.
6396 * Tracing can collect general expressions
6398 You may now collect general expressions at tracepoints. This requires
6399 further additions to the target-side stub; see tracepoint.c and
6400 doc/agentexpr.texi for further details.
6402 * mask-address variable for Mips
6404 For Mips targets, you may control the zeroing of the upper 32 bits of
6405 a 64-bit address by entering `set mask-address on'. This is mainly
6406 of interest to users of embedded R4xxx and R5xxx processors.
6408 * Higher serial baud rates
6410 GDB's serial code now allows you to specify baud rates 57600, 115200,
6411 230400, and 460800 baud. (Note that your host system may not be able
6412 to achieve all of these rates.)
6416 The i960 configuration now includes an initial implementation of a
6417 builtin simulator, contributed by Jim Wilson.
6420 *** Changes in GDB-4.17:
6422 * New native configurations
6424 Alpha GNU/Linux alpha*-*-linux*
6425 Unixware 2.x i[3456]86-unixware2*
6426 Irix 6.x mips*-sgi-irix6*
6427 PowerPC GNU/Linux powerpc-*-linux*
6428 PowerPC Solaris powerpcle-*-solaris*
6429 Sparc GNU/Linux sparc-*-linux*
6430 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6434 Argonaut Risc Chip (ARC) arc-*-*
6435 Hitachi H8/300S h8300*-*-*
6436 Matsushita MN10200 w/simulator mn10200-*-*
6437 Matsushita MN10300 w/simulator mn10300-*-*
6438 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6439 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6440 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6441 Mitsubishi D10V w/simulator d10v-*-*
6442 Mitsubishi M32R/D w/simulator m32r-*-elf*
6443 Tsqware Sparclet sparclet-*-*
6444 NEC V850 w/simulator v850-*-*
6446 * New debugging protocols
6448 ARM with RDI protocol arm*-*-*
6449 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6450 DDB and LSI variants of PMON protocol mips*-*-*
6451 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6452 PowerPC with SDS protocol powerpc{,le}-*-eabi
6453 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6457 All configurations can now understand and use the DWARF 2 debugging
6458 format. The choice is automatic, if the symbol file contains DWARF 2
6463 GDB now includes basic Java language support. This support is
6464 only useful with Java compilers that produce native machine code.
6466 * solib-absolute-prefix and solib-search-path
6468 For SunOS and SVR4 shared libraries, you may now set the prefix for
6469 loading absolute shared library symbol files, and the search path for
6470 locating non-absolute shared library symbol files.
6472 * Live range splitting
6474 GDB can now effectively debug code for which GCC has performed live
6475 range splitting as part of its optimization. See gdb/doc/LRS for
6476 more details on the expected format of the stabs information.
6480 GDB's support for the GNU Hurd, including thread debugging, has been
6481 updated to work with current versions of the Hurd.
6485 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6486 instruction set. ARM GDB automatically detects when Thumb
6487 instructions are in use, and adjusts disassembly and backtracing
6492 GDB's MIPS target configurations now handle the MIP16 16-bit
6497 GDB now includes support for overlays; if an executable has been
6498 linked such that multiple sections are based at the same address, GDB
6499 will decide which section to use for symbolic info. You can choose to
6500 control the decision manually, using overlay commands, or implement
6501 additional target-side support and use "overlay load-target" to bring
6502 in the overlay mapping. Do "help overlay" for more detail.
6506 The command "info symbol <address>" displays information about
6507 the symbol at the specified address.
6511 The standard remote protocol now includes an extension that allows
6512 asynchronous collection and display of trace data. This requires
6513 extensive support in the target-side debugging stub. Tracing mode
6514 includes a new interaction mode in GDB and new commands: see the
6515 file tracepoint.c for more details.
6519 Configurations for embedded MIPS now include a simulator contributed
6520 by Cygnus Solutions. The simulator supports the instruction sets
6521 of most MIPS variants.
6525 Sparc configurations may now include the ERC32 simulator contributed
6526 by the European Space Agency. The simulator is not built into
6527 Sparc targets by default; configure with --enable-sim to include it.
6531 For target configurations that may include multiple variants of a
6532 basic architecture (such as MIPS and SH), you may now set the
6533 architecture explicitly. "set arch" sets, "info arch" lists
6534 the possible architectures.
6536 *** Changes in GDB-4.16:
6538 * New native configurations
6540 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6541 M68K NetBSD m68k-*-netbsd*
6542 PowerPC AIX 4.x powerpc-*-aix*
6543 PowerPC MacOS powerpc-*-macos*
6544 PowerPC Windows NT powerpcle-*-cygwin32
6545 RS/6000 AIX 4.x rs6000-*-aix4*
6549 ARM with RDP protocol arm-*-*
6550 I960 with MON960 i960-*-coff
6551 MIPS VxWorks mips*-*-vxworks*
6552 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6553 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6555 Matra Sparclet sparclet-*-*
6559 The powerpc-eabi configuration now includes the PSIM simulator,
6560 contributed by Andrew Cagney, with assistance from Mike Meissner.
6561 PSIM is a very elaborate model of the PowerPC, including not only
6562 basic instruction set execution, but also details of execution unit
6563 performance and I/O hardware. See sim/ppc/README for more details.
6567 GDB now works with Solaris 2.5.
6569 * Windows 95/NT native
6571 GDB will now work as a native debugger on Windows 95 and Windows NT.
6572 To build it from source, you must use the "gnu-win32" environment,
6573 which uses a DLL to emulate enough of Unix to run the GNU tools.
6574 Further information, binaries, and sources are available at
6575 ftp.cygnus.com, under pub/gnu-win32.
6577 * dont-repeat command
6579 If a user-defined command includes the command `dont-repeat', then the
6580 command will not be repeated if the user just types return. This is
6581 useful if the command is time-consuming to run, so that accidental
6582 extra keystrokes don't run the same command many times.
6584 * Send break instead of ^C
6586 The standard remote protocol now includes an option to send a break
6587 rather than a ^C to the target in order to interrupt it. By default,
6588 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6590 * Remote protocol timeout
6592 The standard remote protocol includes a new variable `remotetimeout'
6593 that allows you to set the number of seconds before GDB gives up trying
6594 to read from the target. The default value is 2.
6596 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6598 By default GDB will automatically keep track of objects as they are
6599 loaded and unloaded by the dynamic linker. By using the command `set
6600 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6601 when shared library events occur, thus allowing you to set breakpoints
6602 in shared libraries which are explicitly loaded by the inferior.
6604 Note this feature does not work on hpux8. On hpux9 you must link
6605 /usr/lib/end.o into your program. This feature should work
6606 automatically on hpux10.
6608 * Irix 5.x hardware watchpoint support
6610 Irix 5 configurations now support the use of hardware watchpoints.
6612 * Mips protocol "SYN garbage limit"
6614 When debugging a Mips target using the `target mips' protocol, you
6615 may set the number of characters that GDB will ignore by setting
6616 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6617 every character. The default value is 1050.
6619 * Recording and replaying remote debug sessions
6621 If you set `remotelogfile' to the name of a file, gdb will write to it
6622 a recording of a remote debug session. This recording may then be
6623 replayed back to gdb using "gdbreplay". See gdbserver/README for
6624 details. This is useful when you have a problem with GDB while doing
6625 remote debugging; you can make a recording of the session and send it
6626 to someone else, who can then recreate the problem.
6628 * Speedups for remote debugging
6630 GDB includes speedups for downloading and stepping MIPS systems using
6631 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6632 and more efficient S-record downloading.
6634 * Memory use reductions and statistics collection
6636 GDB now uses less memory and reports statistics about memory usage.
6637 Try the `maint print statistics' command, for example.
6639 *** Changes in GDB-4.15:
6641 * Psymtabs for XCOFF
6643 The symbol reader for AIX GDB now uses partial symbol tables. This
6644 can greatly improve startup time, especially for large executables.
6646 * Remote targets use caching
6648 Remote targets now use a data cache to speed up communication with the
6649 remote side. The data cache could lead to incorrect results because
6650 it doesn't know about volatile variables, thus making it impossible to
6651 debug targets which use memory mapped I/O devices. `set remotecache
6652 off' turns the data cache off.
6654 * Remote targets may have threads
6656 The standard remote protocol now includes support for multiple threads
6657 in the target system, using new protocol commands 'H' and 'T'. See
6658 gdb/remote.c for details.
6662 If GDB is configured with `--enable-netrom', then it will include
6663 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6664 acts as though it is a bank of ROM on the target board, but you can
6665 write into it over the network. GDB's support consists only of
6666 support for fast loading into the emulated ROM; to debug, you must use
6667 another protocol, such as standard remote protocol. The usual
6668 sequence is something like
6670 target nrom <netrom-hostname>
6672 target remote <netrom-hostname>:1235
6676 GDB now includes support for the Apple Macintosh, as a host only. It
6677 may be run as either an MPW tool or as a standalone application, and
6678 it can debug through the serial port. All the usual GDB commands are
6679 available, but to the target command, you must supply "serial" as the
6680 device type instead of "/dev/ttyXX". See mpw-README in the main
6681 directory for more information on how to build. The MPW configuration
6682 scripts */mpw-config.in support only a few targets, and only the
6683 mips-idt-ecoff target has been tested.
6687 GDB configuration now uses autoconf. This is not user-visible,
6688 but does simplify configuration and building.
6692 GDB now supports hpux10.
6694 *** Changes in GDB-4.14:
6696 * New native configurations
6698 x86 FreeBSD i[345]86-*-freebsd
6699 x86 NetBSD i[345]86-*-netbsd
6700 NS32k NetBSD ns32k-*-netbsd
6701 Sparc NetBSD sparc-*-netbsd
6705 A29K VxWorks a29k-*-vxworks
6706 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6707 CPU32 EST-300 emulator m68*-*-est*
6708 PowerPC ELF powerpc-*-elf
6711 * Alpha OSF/1 support for procfs
6713 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6714 possible to attach to running processes. As the mounting of the /proc
6715 filesystem is optional on the Alpha, GDB automatically determines
6716 the availability of /proc during startup. This can lead to problems
6717 if /proc is unmounted after GDB has been started.
6719 * Arguments to user-defined commands
6721 User commands may accept up to 10 arguments separated by whitespace.
6722 Arguments are accessed within the user command via $arg0..$arg9. A
6725 print $arg0 + $arg1 + $arg2
6727 To execute the command use:
6730 Defines the command "adder" which prints the sum of its three arguments.
6731 Note the arguments are text substitutions, so they may reference variables,
6732 use complex expressions, or even perform inferior function calls.
6734 * New `if' and `while' commands
6736 This makes it possible to write more sophisticated user-defined
6737 commands. Both commands take a single argument, which is the
6738 expression to evaluate, and must be followed by the commands to
6739 execute, one per line, if the expression is nonzero, the list being
6740 terminated by the word `end'. The `if' command list may include an
6741 `else' word, which causes the following commands to be executed only
6742 if the expression is zero.
6744 * Fortran source language mode
6746 GDB now includes partial support for Fortran 77. It will recognize
6747 Fortran programs and can evaluate a subset of Fortran expressions, but
6748 variables and functions may not be handled correctly. GDB will work
6749 with G77, but does not yet know much about symbols emitted by other
6752 * Better HPUX support
6754 Most debugging facilities now work on dynamic executables for HPPAs
6755 running hpux9 or later. You can attach to running dynamically linked
6756 processes, but by default the dynamic libraries will be read-only, so
6757 for instance you won't be able to put breakpoints in them. To change
6758 that behavior do the following before running the program:
6764 This will cause the libraries to be mapped private and read-write.
6765 To revert to the normal behavior, do this:
6771 You cannot set breakpoints or examine data in the library until after
6772 the library is loaded if the function/data symbols do not have
6775 GDB can now also read debug symbols produced by the HP C compiler on
6776 HPPAs (sorry, no C++, Fortran or 68k support).
6778 * Target byte order now dynamically selectable
6780 You can choose which byte order to use with a target system, via the
6781 commands "set endian big" and "set endian little", and you can see the
6782 current setting by using "show endian". You can also give the command
6783 "set endian auto", in which case GDB will use the byte order
6784 associated with the executable. Currently, only embedded MIPS
6785 configurations support dynamic selection of target byte order.
6787 * New DOS host serial code
6789 This version uses DPMI interrupts to handle buffered I/O, so you
6790 no longer need to run asynctsr when debugging boards connected to
6793 *** Changes in GDB-4.13:
6795 * New "complete" command
6797 This lists all the possible completions for the rest of the line, if it
6798 were to be given as a command itself. This is intended for use by emacs.
6800 * Trailing space optional in prompt
6802 "set prompt" no longer adds a space for you after the prompt you set. This
6803 allows you to set a prompt which ends in a space or one that does not.
6805 * Breakpoint hit counts
6807 "info break" now displays a count of the number of times the breakpoint
6808 has been hit. This is especially useful in conjunction with "ignore"; you
6809 can ignore a large number of breakpoint hits, look at the breakpoint info
6810 to see how many times the breakpoint was hit, then run again, ignoring one
6811 less than that number, and this will get you quickly to the last hit of
6814 * Ability to stop printing at NULL character
6816 "set print null-stop" will cause GDB to stop printing the characters of
6817 an array when the first NULL is encountered. This is useful when large
6818 arrays actually contain only short strings.
6820 * Shared library breakpoints
6822 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6823 breakpoints in shared libraries before the executable is run.
6825 * Hardware watchpoints
6827 There is a new hardware breakpoint for the watch command for sparclite
6828 targets. See gdb/sparclite/hw_breakpoint.note.
6830 Hardware watchpoints are also now supported under GNU/Linux.
6834 Annotations have been added. These are for use with graphical interfaces,
6835 and are still experimental. Currently only gdba.el uses these.
6837 * Improved Irix 5 support
6839 GDB now works properly with Irix 5.2.
6841 * Improved HPPA support
6843 GDB now works properly with the latest GCC and GAS.
6845 * New native configurations
6847 Sequent PTX4 i[34]86-sequent-ptx4
6848 HPPA running OSF/1 hppa*-*-osf*
6849 Atari TT running SVR4 m68*-*-sysv4*
6850 RS/6000 LynxOS rs6000-*-lynxos*
6854 OS/9000 i[34]86-*-os9k
6855 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6858 * Hitachi SH7000 and E7000-PC ICE support
6860 There is now support for communicating with the Hitachi E7000-PC ICE.
6861 This is available automatically when GDB is configured for the SH.
6865 As usual, a variety of small fixes and improvements, both generic
6866 and configuration-specific. See the ChangeLog for more detail.
6868 *** Changes in GDB-4.12:
6870 * Irix 5 is now supported
6874 GDB-4.12 on the HPPA has a number of changes which make it unable
6875 to debug the output from the currently released versions of GCC and
6876 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6877 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6878 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6881 *** Changes in GDB-4.11:
6883 * User visible changes:
6887 The "set remotedebug" option is now consistent between the mips remote
6888 target, remote targets using the gdb-specific protocol, UDI (AMD's
6889 debug protocol for the 29k) and the 88k bug monitor. It is now an
6890 integer specifying a debug level (normally 0 or 1, but 2 means more
6891 debugging info for the mips target).
6893 * DEC Alpha native support
6895 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6896 debug info, but GDB works fairly well with the DEC compiler and should
6897 work with a future GCC release. See the README file for a few
6898 Alpha-specific notes.
6900 * Preliminary thread implementation
6902 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6904 * LynxOS native and target support for 386
6906 This release has been hosted on LynxOS 2.2, and also can be configured
6907 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6910 * Improvements in C++ mangling/demangling.
6912 This release has much better g++ debugging, specifically in name
6913 mangling/demangling, virtual function calls, print virtual table,
6914 call methods, ...etc.
6916 *** Changes in GDB-4.10:
6918 * User visible changes:
6920 Remote debugging using the GDB-specific (`target remote') protocol now
6921 supports the `load' command. This is only useful if you have some
6922 other way of getting the stub to the target system, and you can put it
6923 somewhere in memory where it won't get clobbered by the download.
6925 Filename completion now works.
6927 When run under emacs mode, the "info line" command now causes the
6928 arrow to point to the line specified. Also, "info line" prints
6929 addresses in symbolic form (as well as hex).
6931 All vxworks based targets now support a user settable option, called
6932 vxworks-timeout. This option represents the number of seconds gdb
6933 should wait for responses to rpc's. You might want to use this if
6934 your vxworks target is, perhaps, a slow software simulator or happens
6935 to be on the far side of a thin network line.
6939 This release contains support for using a DEC alpha as a GDB host for
6940 cross debugging. Native alpha debugging is not supported yet.
6943 *** Changes in GDB-4.9:
6947 This is the first GDB release which is accompanied by a matching testsuite.
6948 The testsuite requires installation of dejagnu, which should be available
6949 via ftp from most sites that carry GNU software.
6953 'Cfront' style demangling has had its name changed to 'ARM' style, to
6954 emphasize that it was written from the specifications in the C++ Annotated
6955 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6956 disclaimers, it still generated too much confusion with users attempting to
6957 use gdb with AT&T cfront.
6961 GDB now uses a standard remote interface to a simulator library.
6962 So far, the library contains simulators for the Zilog Z8001/2, the
6963 Hitachi H8/300, H8/500 and Super-H.
6965 * New targets supported
6967 H8/300 simulator h8300-hitachi-hms or h8300hms
6968 H8/500 simulator h8500-hitachi-hms or h8500hms
6969 SH simulator sh-hitachi-hms or sh
6970 Z8000 simulator z8k-zilog-none or z8ksim
6971 IDT MIPS board over serial line mips-idt-ecoff
6973 Cross-debugging to GO32 targets is supported. It requires a custom
6974 version of the i386-stub.c module which is integrated with the
6975 GO32 memory extender.
6977 * New remote protocols
6979 MIPS remote debugging protocol.
6981 * New source languages supported
6983 This version includes preliminary support for Chill, a Pascal like language
6984 used by telecommunications companies. Chill support is also being integrated
6985 into the GNU compiler, but we don't know when it will be publically available.
6988 *** Changes in GDB-4.8:
6990 * HP Precision Architecture supported
6992 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6993 version of this support was available as a set of patches from the
6994 University of Utah. GDB does not support debugging of programs
6995 compiled with the HP compiler, because HP will not document their file
6996 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6997 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6999 Many problems in the preliminary version have been fixed.
7001 * Faster and better demangling
7003 We have improved template demangling and fixed numerous bugs in the GNU style
7004 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7005 character types (wchar_t) are now supported. Demangling of each symbol is now
7006 only done once, and is cached when the symbol table for a file is read in.
7007 This results in a small increase in memory usage for C programs, a moderate
7008 increase in memory usage for C++ programs, and a fantastic speedup in
7011 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7012 from the specifications in the Annotated Reference Manual, which AT&T's
7013 compiler does not actually implement.
7015 * G++ multiple inheritance compiler problem
7017 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7018 inheritance lattices was reworked to properly discover ambiguities. We
7019 recently found an example which causes this new algorithm to fail in a
7020 very subtle way, producing bad debug information for those classes.
7021 The file 'gcc.patch' (in this directory) can be applied to gcc to
7022 circumvent the problem. A future GCC release will contain a complete
7025 The previous G++ debug info problem (mentioned below for the gdb-4.7
7026 release) is fixed in gcc version 2.3.2.
7028 * Improved configure script
7030 The `configure' script will now attempt to guess your system type if
7031 you don't supply a host system type. The old scheme of supplying a
7032 host system triplet is preferable over using this. All the magic is
7033 done in the new `config.guess' script. Examine it for details.
7035 We have also brought our configure script much more in line with the FSF's
7036 version. It now supports the --with-xxx options. In particular,
7037 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7038 The resulting GDB will not be able to read arbitrary object file formats --
7039 only the format ``expected'' to be used on the configured target system.
7040 We hope to make this the default in a future release.
7042 * Documentation improvements
7044 There's new internal documentation on how to modify GDB, and how to
7045 produce clean changes to the code. We implore people to read it
7046 before submitting changes.
7048 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7049 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7050 `info' files are also provided. To build `info' files from scratch,
7051 you will need the latest `makeinfo' release, which will be available in
7052 a future texinfo-X.Y release.
7054 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7055 We're not sure exactly which versions have this problem, but it has
7056 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7057 or better. If that isn't possible, there is a patch in
7058 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7059 around this problem.
7063 GDB now supports array constants that can be used in expressions typed in by
7064 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7065 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7068 The new directory `gdb/sparclite' contains a program that demonstrates
7069 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7071 * New native hosts supported
7073 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7074 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7076 * New targets supported
7078 AMD 29k family via UDI a29k-amd-udi or udi29k
7080 * New file formats supported
7082 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7083 HPUX core files, and SCO 3.2v2 core files.
7087 Attaching to processes now works again; thanks for the many bug reports.
7089 We have also stomped on a bunch of core dumps caused by
7090 printf_filtered("%s") problems.
7092 We eliminated a copyright problem on the rpc and ptrace header files
7093 for VxWorks, which was discovered at the last minute during the 4.7
7094 release. You should now be able to build a VxWorks GDB.
7096 You can now interrupt gdb while an attached process is running. This
7097 will cause the attached process to stop, and give control back to GDB.
7099 We fixed problems caused by using too many file descriptors
7100 for reading symbols from object files and libraries. This was
7101 especially a problem for programs that used many (~100) shared
7104 The `step' command now only enters a subroutine if there is line number
7105 information for the subroutine. Otherwise it acts like the `next'
7106 command. Previously, `step' would enter subroutines if there was
7107 any debugging information about the routine. This avoids problems
7108 when using `cc -g1' on MIPS machines.
7110 * Internal improvements
7112 GDB's internal interfaces have been improved to make it easier to support
7113 debugging of multiple languages in the future.
7115 GDB now uses a common structure for symbol information internally.
7116 Minimal symbols (derived from linkage symbols in object files), partial
7117 symbols (from a quick scan of debug information), and full symbols
7118 contain a common subset of information, making it easier to write
7119 shared code that handles any of them.
7121 * New command line options
7123 We now accept --silent as an alias for --quiet.
7127 The memory-mapped-malloc library is now licensed under the GNU Library
7128 General Public License.
7130 *** Changes in GDB-4.7:
7132 * Host/native/target split
7134 GDB has had some major internal surgery to untangle the support for
7135 hosts and remote targets. Now, when you configure GDB for a remote
7136 target, it will no longer load in all of the support for debugging
7137 local programs on the host. When fully completed and tested, this will
7138 ensure that arbitrary host/target combinations are possible.
7140 The primary conceptual shift is to separate the non-portable code in
7141 GDB into three categories. Host specific code is required any time GDB
7142 is compiled on that host, regardless of the target. Target specific
7143 code relates to the peculiarities of the target, but can be compiled on
7144 any host. Native specific code is everything else: it can only be
7145 built when the host and target are the same system. Child process
7146 handling and core file support are two common `native' examples.
7148 GDB's use of /proc for controlling Unix child processes is now cleaner.
7149 It has been split out into a single module under the `target_ops' vector,
7150 plus two native-dependent functions for each system that uses /proc.
7152 * New hosts supported
7154 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7155 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7156 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7158 * New targets supported
7160 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7161 68030 and CPU32 m68030-*-*, m68332-*-*
7163 * New native hosts supported
7165 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7166 (386bsd is not well tested yet)
7167 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7169 * New file formats supported
7171 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7172 supports reading of `a.out.adobe' object files, which are an a.out
7173 format extended with minimal information about multiple sections.
7177 `show copying' is the same as the old `info copying'.
7178 `show warranty' is the same as `info warrantee'.
7179 These were renamed for consistency. The old commands continue to work.
7181 `info handle' is a new alias for `info signals'.
7183 You can now define pre-command hooks, which attach arbitrary command
7184 scripts to any command. The commands in the hook will be executed
7185 prior to the user's command. You can also create a hook which will be
7186 executed whenever the program stops. See gdb.texinfo.
7190 We now deal with Cfront style name mangling, and can even extract type
7191 info from mangled symbols. GDB can automatically figure out which
7192 symbol mangling style your C++ compiler uses.
7194 Calling of methods and virtual functions has been improved as well.
7198 The crash that occured when debugging Sun Ansi-C compiled binaries is
7199 fixed. This was due to mishandling of the extra N_SO stabs output
7202 We also finally got Ultrix 4.2 running in house, and fixed core file
7203 support, with help from a dozen people on the net.
7205 John M. Farrell discovered that the reason that single-stepping was so
7206 slow on all of the Mips based platforms (primarily SGI and DEC) was
7207 that we were trying to demangle and lookup a symbol used for internal
7208 purposes on every instruction that was being stepped through. Changing
7209 the name of that symbol so that it couldn't be mistaken for a C++
7210 mangled symbol sped things up a great deal.
7212 Rich Pixley sped up symbol lookups in general by getting much smarter
7213 about when C++ symbol mangling is necessary. This should make symbol
7214 completion (TAB on the command line) much faster. It's not as fast as
7215 we'd like, but it's significantly faster than gdb-4.6.
7219 A new user controllable variable 'call_scratch_address' can
7220 specify the location of a scratch area to be used when GDB
7221 calls a function in the target. This is necessary because the
7222 usual method of putting the scratch area on the stack does not work
7223 in systems that have separate instruction and data spaces.
7225 We integrated changes to support the 29k UDI (Universal Debugger
7226 Interface), but discovered at the last minute that we didn't have all
7227 of the appropriate copyright paperwork. We are working with AMD to
7228 resolve this, and hope to have it available soon.
7232 We have sped up the remote serial line protocol, especially for targets
7233 with lots of registers. It now supports a new `expedited status' ('T')
7234 message which can be used in place of the existing 'S' status message.
7235 This allows the remote stub to send only the registers that GDB
7236 needs to make a quick decision about single-stepping or conditional
7237 breakpoints, eliminating the need to fetch the entire register set for
7238 each instruction being stepped through.
7240 The GDB remote serial protocol now implements a write-through cache for
7241 registers, only re-reading the registers if the target has run.
7243 There is also a new remote serial stub for SPARC processors. You can
7244 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7245 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7246 processor with a serial port.
7250 Configure.in files have become much easier to read and modify. A new
7251 `table driven' format makes it more obvious what configurations are
7252 supported, and what files each one uses.
7256 There is a new opcodes library which will eventually contain all of the
7257 disassembly routines and opcode tables. At present, it only contains
7258 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7259 disassembler (binutils/objdump) to share these routines.
7261 The libiberty library is now copylefted under the GNU Library General
7262 Public License. This allows more liberal use, and was done so libg++
7263 can use it. This makes no difference to GDB, since the Library License
7264 grants all the rights from the General Public License.
7268 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7269 reference to the stabs symbol info used by the debugger. It is (as far
7270 as we know) the only published document on this fascinating topic. We
7271 encourage you to read it, compare it to the stabs information on your
7272 system, and send improvements on the document in general (to
7273 bug-gdb@prep.ai.mit.edu).
7275 And, of course, many bugs have been fixed.
7278 *** Changes in GDB-4.6:
7280 * Better support for C++ function names
7282 GDB now accepts as input the "demangled form" of C++ overloaded function
7283 names and member function names, and can do command completion on such names
7284 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7285 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7286 Make use of command completion, it is your friend.
7288 GDB also now accepts a variety of C++ mangled symbol formats. They are
7289 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7290 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7291 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7292 for the list of formats.
7294 * G++ symbol mangling problem
7296 Recent versions of gcc have a bug in how they emit debugging information for
7297 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7298 directory) can be applied to gcc to fix the problem. Alternatively, if you
7299 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7300 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7301 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7304 * New 'maintenance' command
7306 All of the commands related to hacking GDB internals have been moved out of
7307 the main command set, and now live behind the 'maintenance' command. This
7308 can also be abbreviated as 'mt'. The following changes were made:
7310 dump-me -> maintenance dump-me
7311 info all-breakpoints -> maintenance info breakpoints
7312 printmsyms -> maintenance print msyms
7313 printobjfiles -> maintenance print objfiles
7314 printpsyms -> maintenance print psymbols
7315 printsyms -> maintenance print symbols
7317 The following commands are new:
7319 maintenance demangle Call internal GDB demangler routine to
7320 demangle a C++ link name and prints the result.
7321 maintenance print type Print a type chain for a given symbol
7323 * Change to .gdbinit file processing
7325 We now read the $HOME/.gdbinit file before processing the argv arguments
7326 (e.g. reading symbol files or core files). This allows global parameters to
7327 be set, which will apply during the symbol reading. The ./.gdbinit is still
7328 read after argv processing.
7330 * New hosts supported
7332 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7334 GNU/Linux support i386-unknown-linux or linux
7336 We are also including code to support the HP/PA running BSD and HPUX. This
7337 is almost guaranteed not to work, as we didn't have time to test or build it
7338 for this release. We are including it so that the more adventurous (or
7339 masochistic) of you can play with it. We also had major problems with the
7340 fact that the compiler that we got from HP doesn't support the -g option.
7343 * New targets supported
7345 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7347 * More smarts about finding #include files
7349 GDB now remembers the compilation directory for all include files, and for
7350 all files from which C is generated (like yacc and lex sources). This
7351 greatly improves GDB's ability to find yacc/lex sources, and include files,
7352 especially if you are debugging your program from a directory different from
7353 the one that contains your sources.
7355 We also fixed a bug which caused difficulty with listing and setting
7356 breakpoints in include files which contain C code. (In the past, you had to
7357 try twice in order to list an include file that you hadn't looked at before.)
7359 * Interesting infernals change
7361 GDB now deals with arbitrary numbers of sections, where the symbols for each
7362 section must be relocated relative to that section's landing place in the
7363 target's address space. This work was needed to support ELF with embedded
7364 stabs used by Solaris-2.0.
7366 * Bug fixes (of course!)
7368 There have been loads of fixes for the following things:
7369 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7370 i960, stabs, DOS(GO32), procfs, etc...
7372 See the ChangeLog for details.
7374 *** Changes in GDB-4.5:
7376 * New machines supported (host and target)
7378 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7380 SGI Irix-4.x mips-sgi-irix4 or iris4
7382 * New malloc package
7384 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7385 Mmalloc is capable of handling mutiple heaps of memory. It is also
7386 capable of saving a heap to a file, and then mapping it back in later.
7387 This can be used to greatly speedup the startup of GDB by using a
7388 pre-parsed symbol table which lives in a mmalloc managed heap. For
7389 more details, please read mmalloc/mmalloc.texi.
7393 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7394 'help info proc' for details.
7396 * MIPS ecoff symbol table format
7398 The code that reads MIPS symbol table format is now supported on all hosts.
7399 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7402 * File name changes for MS-DOS
7404 Many files in the config directories have been renamed to make it easier to
7405 support GDB on MS-DOSe systems (which have very restrictive file name
7406 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7407 environment) is close to working but has some remaining problems. Note
7408 that debugging of DOS programs is not supported, due to limitations
7409 in the ``operating system'', but it can be used to host cross-debugging.
7411 * Cross byte order fixes
7413 Many fixes have been made to support cross debugging of Sparc and MIPS
7414 targets from hosts whose byte order differs.
7416 * New -mapped and -readnow options
7418 If memory-mapped files are available on your system through the 'mmap'
7419 system call, you can use the -mapped option on the `file' or
7420 `symbol-file' commands to cause GDB to write the symbols from your
7421 program into a reusable file. If the program you are debugging is
7422 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7423 Future GDB debugging sessions will notice the presence of this file,
7424 and will quickly map in symbol information from it, rather than reading
7425 the symbol table from the executable program. Using the '-mapped'
7426 option in a GDB `file' or `symbol-file' command has the same effect as
7427 starting GDB with the '-mapped' command-line option.
7429 You can cause GDB to read the entire symbol table immediately by using
7430 the '-readnow' option with any of the commands that load symbol table
7431 information (or on the GDB command line). This makes the command
7432 slower, but makes future operations faster.
7434 The -mapped and -readnow options are typically combined in order to
7435 build a `fred.syms' file that contains complete symbol information.
7436 A simple GDB invocation to do nothing but build a `.syms' file for future
7439 gdb -batch -nx -mapped -readnow programname
7441 The `.syms' file is specific to the host machine on which GDB is run.
7442 It holds an exact image of GDB's internal symbol table. It cannot be
7443 shared across multiple host platforms.
7445 * longjmp() handling
7447 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7448 siglongjmp() without losing control. This feature has not yet been ported to
7449 all systems. It currently works on many 386 platforms, all MIPS-based
7450 platforms (SGI, DECstation, etc), and Sun3/4.
7454 Preliminary work has been put in to support the new Solaris OS from Sun. At
7455 this time, it can control and debug processes, but it is not capable of
7460 As always, many many bug fixes. The major areas were with g++, and mipsread.
7461 People using the MIPS-based platforms should experience fewer mysterious
7462 crashes and trashed symbol tables.
7464 *** Changes in GDB-4.4:
7466 * New machines supported (host and target)
7468 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7470 BSD Reno on Vax vax-dec-bsd
7471 Ultrix on Vax vax-dec-ultrix
7473 * New machines supported (target)
7475 AMD 29000 embedded, using EBMON a29k-none-none
7479 GDB continues to improve its handling of C++. `References' work better.
7480 The demangler has also been improved, and now deals with symbols mangled as
7481 per the Annotated C++ Reference Guide.
7483 GDB also now handles `stabs' symbol information embedded in MIPS
7484 `ecoff' symbol tables. Since the ecoff format was not easily
7485 extensible to handle new languages such as C++, this appeared to be a
7486 good way to put C++ debugging info into MIPS binaries. This option
7487 will be supported in the GNU C compiler, version 2, when it is
7490 * New features for SVR4
7492 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7493 shared libraries. Debugging dynamically linked programs should present
7494 only minor differences from debugging statically linked programs.
7496 The `info proc' command will print out information about any process
7497 on an SVR4 system (including the one you are debugging). At the moment,
7498 it prints the address mappings of the process.
7500 If you bring up GDB on another SVR4 system, please send mail to
7501 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7503 * Better dynamic linking support in SunOS
7505 Reading symbols from shared libraries which contain debugging symbols
7506 now works properly. However, there remain issues such as automatic
7507 skipping of `transfer vector' code during function calls, which
7508 make it harder to debug code in a shared library, than to debug the
7509 same code linked statically.
7513 GDB is now using the latest `getopt' routines from the FSF. This
7514 version accepts the -- prefix for options with long names. GDB will
7515 continue to accept the old forms (-option and +option) as well.
7516 Various single letter abbreviations for options have been explicity
7517 added to the option table so that they won't get overshadowed in the
7518 future by other options that begin with the same letter.
7522 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7523 Many assorted bugs have been handled. Many more remain to be handled.
7524 See the various ChangeLog files (primarily in gdb and bfd) for details.
7527 *** Changes in GDB-4.3:
7529 * New machines supported (host and target)
7531 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7532 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7533 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7535 * Almost SCO Unix support
7537 We had hoped to support:
7538 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7539 (except for core file support), but we discovered very late in the release
7540 that it has problems with process groups that render gdb unusable. Sorry
7541 about that. I encourage people to fix it and post the fixes.
7543 * Preliminary ELF and DWARF support
7545 GDB can read ELF object files on System V Release 4, and can handle
7546 debugging records for C, in DWARF format, in ELF files. This support
7547 is preliminary. If you bring up GDB on another SVR4 system, please
7548 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7553 GDB now uses the latest `readline' library. One user-visible change
7554 is that two tabs will list possible command completions, which previously
7555 required typing M-? (meta-question mark, or ESC ?).
7559 The `stepi' bug that many of you noticed has been squashed.
7560 Many bugs in C++ have been handled. Many more remain to be handled.
7561 See the various ChangeLog files (primarily in gdb and bfd) for details.
7563 * State of the MIPS world (in case you wondered):
7565 GDB can understand the symbol tables emitted by the compilers
7566 supplied by most vendors of MIPS-based machines, including DEC. These
7567 symbol tables are in a format that essentially nobody else uses.
7569 Some versions of gcc come with an assembler post-processor called
7570 mips-tfile. This program is required if you want to do source-level
7571 debugging of gcc-compiled programs. I believe FSF does not ship
7572 mips-tfile with gcc version 1, but it will eventually come with gcc
7575 Debugging of g++ output remains a problem. g++ version 1.xx does not
7576 really support it at all. (If you're lucky, you should be able to get
7577 line numbers and stack traces to work, but no parameters or local
7578 variables.) With some work it should be possible to improve the
7581 When gcc version 2 is released, you will have somewhat better luck.
7582 However, even then you will get confusing results for inheritance and
7585 We will eventually provide full debugging of g++ output on
7586 DECstations. This will probably involve some kind of stabs-in-ecoff
7587 encapulation, but the details have not been worked out yet.
7590 *** Changes in GDB-4.2:
7592 * Improved configuration
7594 Only one copy of `configure' exists now, and it is not self-modifying.
7595 Porting BFD is simpler.
7599 The `step' and `next' commands now only stop at the first instruction
7600 of a source line. This prevents the multiple stops that used to occur
7601 in switch statements, for-loops, etc. `Step' continues to stop if a
7602 function that has debugging information is called within the line.
7606 Lots of small bugs fixed. More remain.
7608 * New host supported (not target)
7610 Intel 386 PC clone running Mach i386-none-mach
7613 *** Changes in GDB-4.1:
7615 * Multiple source language support
7617 GDB now has internal scaffolding to handle several source languages.
7618 It determines the type of each source file from its filename extension,
7619 and will switch expression parsing and number formatting to match the
7620 language of the function in the currently selected stack frame.
7621 You can also specifically set the language to be used, with
7622 `set language c' or `set language modula-2'.
7626 GDB now has preliminary support for the GNU Modula-2 compiler,
7627 currently under development at the State University of New York at
7628 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7629 continue through the fall of 1991 and into 1992.
7631 Other Modula-2 compilers are currently not supported, and attempting to
7632 debug programs compiled with them will likely result in an error as the
7633 symbol table is read. Feel free to work on it, though!
7635 There are hooks in GDB for strict type checking and range checking,
7636 in the `Modula-2 philosophy', but they do not currently work.
7640 GDB can now write to executable and core files (e.g. patch
7641 a variable's value). You must turn this switch on, specify
7642 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7643 by assigning a new value to a variable. Modifications take
7646 * Automatic SunOS shared library reading
7648 When you run your program, GDB automatically determines where its
7649 shared libraries (if any) have been loaded, and reads their symbols.
7650 The `share' command is no longer needed. This also works when
7651 examining core files.
7655 You can specify the number of lines that the `list' command shows.
7658 * New machines supported (host and target)
7660 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7661 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7662 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7664 * New hosts supported (not targets)
7666 IBM RT/PC: romp-ibm-aix or rtpc
7668 * New targets supported (not hosts)
7670 AMD 29000 embedded with COFF a29k-none-coff
7671 AMD 29000 embedded with a.out a29k-none-aout
7672 Ultracomputer remote kernel debug a29k-nyu-kern
7674 * New remote interfaces
7680 *** Changes in GDB-4.0:
7684 Wide output is wrapped at good places to make the output more readable.
7686 Gdb now supports cross-debugging from a host machine of one type to a
7687 target machine of another type. Communication with the target system
7688 is over serial lines. The ``target'' command handles connecting to the
7689 remote system; the ``load'' command will download a program into the
7690 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7691 also supports debugging of realtime processes running under VxWorks,
7692 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7693 stub on the target system.
7695 New CPUs supported include the AMD 29000 and Intel 960.
7697 GDB now reads object files and symbol tables via a ``binary file''
7698 library, which allows a single copy of GDB to debug programs of multiple
7699 object file types such as a.out and coff.
7701 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7702 refcard.dvi and refcard.ps are available to format it).
7705 * Control-Variable user interface simplified
7707 All variables that control the operation of the debugger can be set
7708 by the ``set'' command, and displayed by the ``show'' command.
7710 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7711 ``Show prompt'' produces the response:
7712 Gdb's prompt is new-gdb=>.
7714 What follows are the NEW set commands. The command ``help set'' will
7715 print a complete list of old and new set commands. ``help set FOO''
7716 will give a longer description of the variable FOO. ``show'' will show
7717 all of the variable descriptions and their current settings.
7719 confirm on/off: Enables warning questions for operations that are
7720 hard to recover from, e.g. rerunning the program while
7721 it is already running. Default is ON.
7723 editing on/off: Enables EMACS style command line editing
7724 of input. Previous lines can be recalled with
7725 control-P, the current line can be edited with control-B,
7726 you can search for commands with control-R, etc.
7729 history filename NAME: NAME is where the gdb command history
7730 will be stored. The default is .gdb_history,
7731 or the value of the environment variable
7734 history size N: The size, in commands, of the command history. The
7735 default is 256, or the value of the environment variable
7738 history save on/off: If this value is set to ON, the history file will
7739 be saved after exiting gdb. If set to OFF, the
7740 file will not be saved. The default is OFF.
7742 history expansion on/off: If this value is set to ON, then csh-like
7743 history expansion will be performed on
7744 command line input. The default is OFF.
7746 radix N: Sets the default radix for input and output. It can be set
7747 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7748 in the current radix, so "set radix 10" is always a no-op.
7750 height N: This integer value is the number of lines on a page. Default
7751 is 24, the current `stty rows'' setting, or the ``li#''
7752 setting from the termcap entry matching the environment
7755 width N: This integer value is the number of characters on a line.
7756 Default is 80, the current `stty cols'' setting, or the ``co#''
7757 setting from the termcap entry matching the environment
7760 Note: ``set screensize'' is obsolete. Use ``set height'' and
7761 ``set width'' instead.
7763 print address on/off: Print memory addresses in various command displays,
7764 such as stack traces and structure values. Gdb looks
7765 more ``symbolic'' if you turn this off; it looks more
7766 ``machine level'' with it on. Default is ON.
7768 print array on/off: Prettyprint arrays. New convenient format! Default
7771 print demangle on/off: Print C++ symbols in "source" form if on,
7774 print asm-demangle on/off: Same, for assembler level printouts
7777 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7780 * Support for Epoch Environment.
7782 The epoch environment is a version of Emacs v18 with windowing. One
7783 new command, ``inspect'', is identical to ``print'', except that if you
7784 are running in the epoch environment, the value is printed in its own
7788 * Support for Shared Libraries
7790 GDB can now debug programs and core files that use SunOS shared libraries.
7791 Symbols from a shared library cannot be referenced
7792 before the shared library has been linked with the program (this
7793 happens after you type ``run'' and before the function main() is entered).
7794 At any time after this linking (including when examining core files
7795 from dynamically linked programs), gdb reads the symbols from each
7796 shared library when you type the ``sharedlibrary'' command.
7797 It can be abbreviated ``share''.
7799 sharedlibrary REGEXP: Load shared object library symbols for files
7800 matching a unix regular expression. No argument
7801 indicates to load symbols for all shared libraries.
7803 info sharedlibrary: Status of loaded shared libraries.
7808 A watchpoint stops execution of a program whenever the value of an
7809 expression changes. Checking for this slows down execution
7810 tremendously whenever you are in the scope of the expression, but is
7811 quite useful for catching tough ``bit-spreader'' or pointer misuse
7812 problems. Some machines such as the 386 have hardware for doing this
7813 more quickly, and future versions of gdb will use this hardware.
7815 watch EXP: Set a watchpoint (breakpoint) for an expression.
7817 info watchpoints: Information about your watchpoints.
7819 delete N: Deletes watchpoint number N (same as breakpoints).
7820 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7821 enable N: Re-enables watchpoint number N (same as breakpoints).
7824 * C++ multiple inheritance
7826 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7829 * C++ exception handling
7831 Gdb now supports limited C++ exception handling. Besides the existing
7832 ability to breakpoint on an exception handler, gdb can breakpoint on
7833 the raising of an exception (before the stack is peeled back to the
7836 catch FOO: If there is a FOO exception handler in the dynamic scope,
7837 set a breakpoint to catch exceptions which may be raised there.
7838 Multiple exceptions (``catch foo bar baz'') may be caught.
7840 info catch: Lists all exceptions which may be caught in the
7841 current stack frame.
7844 * Minor command changes
7846 The command ``call func (arg, arg, ...)'' now acts like the print
7847 command, except it does not print or save a value if the function's result
7848 is void. This is similar to dbx usage.
7850 The ``up'' and ``down'' commands now always print the frame they end up
7851 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7852 frames without printing.
7854 * New directory command
7856 'dir' now adds directories to the FRONT of the source search path.
7857 The path starts off empty. Source files that contain debug information
7858 about the directory in which they were compiled can be found even
7859 with an empty path; Sun CC and GCC include this information. If GDB can't
7860 find your source file in the current directory, type "dir .".
7862 * Configuring GDB for compilation
7864 For normal use, type ``./configure host''. See README or gdb.texinfo
7867 GDB now handles cross debugging. If you are remotely debugging between
7868 two different machines, type ``./configure host -target=targ''.
7869 Host is the machine where GDB will run; targ is the machine
7870 where the program that you are debugging will run.