1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
7 debugging information as well as source code.
9 When built with debuginfod, GDB can automatically query debuginfod
10 servers for the separate debug files and source code of the executable
13 To build GDB with debuginfod, pass --with-debuginfod to configure (this
14 requires libdebuginfod, the debuginfod client library).
16 debuginfod is distributed with elfutils, starting with version 0.178.
18 You can get the latest version from https://sourceware.org/elfutils.
20 * New features in the GDB remote stub, GDBserver
22 ** GDBserver is now supported on RISC-V GNU/Linux.
24 * Debugging MS-Windows processes now sets $_exitsignal when the
25 inferior is terminated by a signal, instead of setting $_exitcode.
27 * Multithreaded symbol loading has now been enabled by default on systems
28 that support it (see entry for GDB 9, below), providing faster
29 performance for programs with many symbols.
31 * The $_siginfo convenience variable now also works on Windows targets,
32 and will display the EXCEPTION_RECORD of the last handled exception.
34 * TUI windows can now be arranged horizontally.
36 * The command history filename can now be set to the empty string
37 either using 'set history filename' or by setting 'GDBHISTFILE=' in
38 the environment. The effect of setting this filename to the empty
39 string is that GDB will not try to load any previous command
42 * On Windows targets, it is now possible to debug 32-bit programs with a
47 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
48 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
49 Set or show the option 'exec-file-mismatch'. When GDB attaches to
50 a running process and can determine the name of the executable file
51 the process runs, this new option indicates whether to detect mismatch
52 between the name of the current executable file loaded by GDB
53 and the name of the executable file used to start the process.
54 If 'ask', the default, display a warning and ask the user
55 whether to load the process executable file; if 'warn', just display
56 a warning; if 'off', don't attempt to detect a mismatch.
58 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
59 Define a new TUI layout, specifying its name and the windows that
64 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
68 ** gdb.register_window_type can be used to implement new TUI windows
71 ** Dynamic types can now be queried. gdb.Type has a new attribute,
72 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
73 field of a dynamic type may have None for its "bitpos" attribute
76 ** Commands written in Python can be in the "TUI" help class by
77 registering with the new constant gdb.COMMAND_TUI.
81 * 'thread-exited' event is now available in the annotations interface.
83 * New built-in convenience variables $_gdb_major and $_gdb_minor
84 provide the GDB version. They are handy for conditionally using
85 features available only in or since specific GDB versions, in
86 scripts that should work error-free with many different versions,
87 such as in system-wide init files.
89 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
90 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
91 of the GDB settings and the GDB maintenance settings. They are handy
92 for changing the logic of user defined commands depending on the
95 * GDB now supports Thread Local Storage (TLS) variables on several
96 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
97 architectures require kernel changes. TLS is not yet supported for
98 amd64 and i386 process core dumps.
100 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
101 addresses that required unmasking are shown in the backtrace with the
104 * Two new convenience functions $_cimag and $_creal that extract the
105 imaginary and real parts respectively from complex numbers.
107 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
108 provide the exitcode or exit status of the shell commands launched by
109 GDB commands such as "shell", "pipe" and "make".
111 * The command define-prefix can now define user defined prefix commands.
112 User defined commands can now be defined using these user defined prefix
115 * Command names can now use the . character.
117 * The RX port now supports XML target descriptions.
119 * GDB now shows the Ada task names at more places, e.g. in task switching
122 * GDB can now be compiled with Python 3 on Windows.
124 * New convenience variable $_ada_exception holds the address of the
125 Ada exception being thrown. This is set by Ada-related catchpoints.
127 * GDB can now place breakpoints on nested functions and subroutines in
128 Fortran code. The '::' operator can be used between parent and
129 child scopes when placing breakpoints, for example:
131 (gdb) break outer_function::inner_function
133 The 'outer_function::' prefix is only needed if 'inner_function' is
134 not visible in the current scope.
136 * In addition to the system-wide gdbinit file, if configured with
137 --with-system-gdbinit-dir, GDB will now also load files in that directory
138 as system gdbinit files, unless the -nx or -n flag is provided. Files
139 with extensions .gdb, .py and .scm are supported as long as GDB was
140 compiled with support for that language.
142 * GDB now supports multithreaded symbol loading for higher performance.
143 This feature is still in testing, so it is disabled by default. You
144 can turn it on using 'maint set worker-threads unlimited'.
146 * Multi-target debugging support
148 GDB now supports debugging multiple target connections
149 simultaneously. For example, you can now have each inferior
150 connected to different remote servers running in different machines,
151 or have one inferior debugging a local native process, an inferior
152 debugging a core dump, etc.
154 This support is experimental and comes with some limitations -- you
155 can only resume multiple targets simultaneously if all targets
156 support non-stop mode, and all remote stubs or servers must support
157 the same set of remote protocol features exactly. See also "info
158 connections" and "add-inferior -no-connection" below, and "maint set
159 target-non-stop" in the user manual.
163 ** The gdb.Value type has a new method 'format_string' which returns a
164 string representing the value. The formatting is controlled by the
165 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
166 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
167 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
169 ** gdb.Type has a new property 'objfile' which returns the objfile the
172 ** The frame information printed by the python frame filtering code
173 is now consistent with what the 'backtrace' command prints when
174 there are no filters, or when the 'backtrace' '-no-filters' option
177 ** The new function gdb.lookup_static_symbol can be used to look up
178 symbols with static linkage.
180 ** The new function gdb.lookup_static_symbols can be used to look up
181 all static symbols with static linkage.
183 ** gdb.Objfile has new methods 'lookup_global_symbol' and
184 'lookup_static_symbol' to lookup a symbol from this objfile only.
186 ** gdb.Block now supports the dictionary syntax for accessing symbols in
187 this block (e.g. block['local_variable']).
191 | [COMMAND] | SHELL_COMMAND
192 | -d DELIM COMMAND DELIM SHELL_COMMAND
193 pipe [COMMAND] | SHELL_COMMAND
194 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
195 Executes COMMAND and sends its output to SHELL_COMMAND.
196 With no COMMAND, repeat the last executed command
197 and send its output to SHELL_COMMAND.
199 define-prefix COMMAND
200 Define or mark a command as a user-defined prefix command.
202 with SETTING [VALUE] [-- COMMAND]
203 w SETTING [VALUE] [-- COMMAND]
204 Temporarily set SETTING, run COMMAND, and restore SETTING.
205 Usage: with SETTING -- COMMAND
206 With no COMMAND, repeats the last executed command.
207 SETTING is any GDB setting you can change with the "set"
208 subcommands. For example, 'with language c -- print someobj'
209 temporarily switches to the C language in order to print someobj.
210 Settings can be combined: 'w lang c -- w print elements unlimited --
211 usercmd' switches to the C language and runs usercmd with no limit
212 of array elements to print.
214 maint with SETTING [VALUE] [-- COMMAND]
215 Like "with", but works with "maintenance set" settings.
217 set may-call-functions [on|off]
218 show may-call-functions
219 This controls whether GDB will attempt to call functions in
220 the program, such as with expressions in the print command. It
221 defaults to on. Calling functions in the program being debugged
222 can have undesired side effects. It is now possible to forbid
223 such function calls. If function calls are forbidden, GDB will throw
224 an error when a command (such as print expression) calls a function
227 set print finish [on|off]
229 This controls whether the `finish' command will display the value
230 that is returned by the current function. When `off', the value is
231 still entered into the value history, but it is not printed. The
236 Allows deeply nested structures to be simplified when printing by
237 replacing deeply nested parts (beyond the max-depth) with ellipses.
238 The default max-depth is 20, but this can be set to unlimited to get
239 the old behavior back.
241 set print raw-values [on|off]
242 show print raw-values
243 By default, GDB applies the enabled pretty printers when printing a
244 value. This allows to ignore the enabled pretty printers for a series
245 of commands. The default is 'off'.
247 set logging debugredirect [on|off]
248 By default, GDB debug output will go to both the terminal and the logfile.
249 Set if you want debug output to go only to the log file.
251 set style title foreground COLOR
252 set style title background COLOR
253 set style title intensity VALUE
254 Control the styling of titles.
256 set style highlight foreground COLOR
257 set style highlight background COLOR
258 set style highlight intensity VALUE
259 Control the styling of highlightings.
261 maint set worker-threads
262 maint show worker-threads
263 Control the number of worker threads that can be used by GDB. The
264 default is 0. "unlimited" lets GDB choose a number that is
265 reasonable. Currently worker threads are only used when demangling
266 the names of linker symbols.
268 set style tui-border foreground COLOR
269 set style tui-border background COLOR
270 Control the styling of TUI borders.
272 set style tui-active-border foreground COLOR
273 set style tui-active-border background COLOR
274 Control the styling of the active TUI border.
276 maint set test-settings KIND
277 maint show test-settings KIND
278 A set of commands used by the testsuite for exercising the settings
281 maint set tui-resize-message [on|off]
282 maint show tui-resize-message
283 Control whether GDB prints a message each time the terminal is
284 resized when in TUI mode. This is primarily useful for testing the
287 set print frame-info [short-location|location|location-and-address
288 |source-and-location|source-line|auto]
289 show print frame-info
290 This controls what frame information is printed by the commands printing
291 a frame. This setting will e.g. influence the behaviour of 'backtrace',
292 'frame', 'stepi'. The python frame filtering also respect this setting.
293 The 'backtrace' '-frame-info' option can override this global setting.
295 set tui compact-source
296 show tui compact-source
298 Enable the "compact" display mode for the TUI source window. The
299 compact display uses only as much space as is needed for the line
300 numbers in the current file, and only a single space to separate the
301 line numbers from the source.
303 info modules [-q] [REGEXP]
304 Return a list of Fortran modules matching REGEXP, or all modules if
307 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
308 Return a list of functions within all modules, grouped by module.
309 The list of functions can be restricted with the optional regular
310 expressions. MODULE_REGEXP matches against the module name,
311 TYPE_REGEXP matches against the function type signature, and REGEXP
312 matches against the function name.
314 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
315 Return a list of variables within all modules, grouped by module.
316 The list of variables can be restricted with the optional regular
317 expressions. MODULE_REGEXP matches against the module name,
318 TYPE_REGEXP matches against the variable type, and REGEXP matches
319 against the variable name.
321 set debug remote-packet-max-chars
322 show debug remote-packet-max-chars
323 Controls the number of characters to output in a remote packet when using
325 The default is 512 bytes.
328 Lists the target connections currently in use.
333 The "help" command uses the title style to enhance the
334 readibility of its output by styling the classes and
338 Similarly to "help", the "apropos" command also uses the
339 title style for the command names. "apropos" accepts now
340 a flag "-v" (verbose) to show the full documentation
341 of matching commands and to use the highlight style to mark
342 the documentation parts matching REGEXP.
346 The GDB printf and eval commands can now print C-style and Ada-style
347 string convenience variables without calling functions in the program.
348 This allows to do formatted printing of strings without having
349 a running inferior, or when debugging a core dump.
351 info sources [-dirname | -basename] [--] [REGEXP]
352 This command has now optional arguments to only print the files
353 whose names match REGEXP. The arguments -dirname and -basename
354 allow to restrict matching respectively to the dirname and basename
358 The "show style" and its subcommands are now styling
359 a style name in their output using its own style, to help
360 the user visualize the different styles.
362 set print frame-arguments
363 The new value 'presence' indicates to only indicate the presence of
364 arguments using ..., instead of printing argument names and values.
366 set print raw-frame-arguments
367 show print raw-frame-arguments
369 These commands replace the similarly-named "set/show print raw
370 frame-arguments" commands (now with a dash instead of a space). The
371 old commands are now deprecated and may be removed in a future
374 add-inferior [-no-connection]
375 The add-inferior command now supports a "-no-connection" flag that
376 makes the new inferior start with no target connection associated.
377 By default, the new inferior inherits the target connection of the
378 current inferior. See also "info connections".
381 This command's output now includes a new "Connection" column
382 indicating which target connection an inferior is bound to. See
383 "info connections" above.
385 maint test-options require-delimiter
386 maint test-options unknown-is-error
387 maint test-options unknown-is-operand
388 maint show test-options-completion-result
389 Commands used by the testsuite to validate the command options
392 focus, winheight, +, -, >, <
393 These commands are now case-sensitive.
395 * New command options, command completion
397 GDB now has a standard infrastructure to support dash-style command
398 options ('-OPT'). One benefit is that commands that use it can
399 easily support completion of command line arguments. Try "CMD
400 -[TAB]" or "help CMD" to find options supported by a command. Over
401 time, we intend to migrate most commands to this infrastructure. A
402 number of commands got support for new command options in this
405 ** The "print" and "compile print" commands now support a number of
406 options that allow overriding relevant global print settings as
407 set by "set print" subcommands:
411 -array-indexes [on|off]
412 -elements NUMBER|unlimited
417 -repeats NUMBER|unlimited
418 -static-members [on|off]
423 Note that because the "print"/"compile print" commands accept
424 arbitrary expressions which may look like options (including
425 abbreviations), if you specify any command option, then you must
426 use a double dash ("--") to mark the end of argument processing.
428 ** The "backtrace" command now supports a number of options that
429 allow overriding relevant global print settings as set by "set
430 backtrace" and "set print" subcommands:
432 -entry-values no|only|preferred|if-needed|both|compact|default
433 -frame-arguments all|scalars|none
434 -raw-frame-arguments [on|off]
435 -frame-info auto|source-line|location|source-and-location
436 |location-and-address|short-location
440 In addition, the full/no-filters/hide qualifiers are now also
441 exposed as command options too:
447 ** The "frame apply", "tfaas" and "faas" commands similarly now
448 support the following options:
453 ** The new "info sources" options -dirname and -basename options
454 are using the standard '-OPT' infrastructure.
456 All options above can also be abbreviated. The argument of boolean
457 (on/off) options can be 0/1 too, and also the argument is assumed
458 "on" if omitted. This allows writing compact command invocations,
461 (gdb) p -ra -p -o 0 -- *myptr
463 The above is equivalent to:
465 (gdb) print -raw-values -pretty -object off -- *myptr
467 ** The "info types" command now supports the '-q' flag to disable
468 printing of some header information in a similar fashion to "info
469 variables" and "info functions".
471 ** The "info variables", "info functions", and "whereis" commands
472 now take a '-n' flag that excludes non-debug symbols (symbols
473 from the symbol table, not from the debug info such as DWARF)
476 * Completion improvements
478 ** GDB can now complete the options of the "thread apply all" and
479 "taas" commands, and their "-ascending" option can now be
482 ** GDB can now complete the options of the "info threads", "info
483 functions", "info variables", "info locals", and "info args"
486 ** GDB can now complete the options of the "compile file" and
487 "compile code" commands. The "compile file" command now
488 completes on filenames.
490 ** GDB can now complete the backtrace command's
491 "full/no-filters/hide" qualifiers.
493 * In settings, you can now abbreviate "unlimited".
495 E.g., "set print elements u" is now equivalent to "set print
501 This lists all the possible completions for the rest of the line, if it
502 were to be given as a command itself. This is intended for use by MI
503 frontends in cases when separate CLI and MI channels cannot be used.
505 -catch-throw, -catch-rethrow, and -catch-catch
506 These can be used to catch C++ exceptions in a similar fashion to
507 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
509 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
510 These commands are the MI equivalent of the CLI commands 'info
511 functions', 'info types', and 'info variables' respectively.
513 -symbol-info-modules, this is the MI equivalent of the CLI 'info
516 -symbol-info-module-functions and -symbol-info-module-variables.
517 These commands are the MI equivalent of the CLI commands 'info
518 module functions' and 'info module variables'.
522 ** The default version of the MI interpreter is now 3 (-i=mi3).
524 ** The output of information about multi-location breakpoints (which is
525 syntactically incorrect in MI 2) has changed in MI 3. This affects
526 the following commands and events:
530 - =breakpoint-created
531 - =breakpoint-modified
533 The -fix-multi-location-breakpoint-output command can be used to enable
534 this behavior with previous MI versions.
536 ** Backtraces and frames include a new optional field addr_flags which is
537 given after the addr field. On AArch64 this contains PAC if the address
538 has been masked in the frame. On all other targets the field is not
543 The testsuite now creates the files gdb.cmd (containing the arguments
544 used to launch GDB) and gdb.in (containing all the commands sent to
545 GDB) in the output directory for each test script. Multiple invocations
546 are appended with .1, .2, .3 etc.
548 * Building GDB and GDBserver now requires GNU make >= 3.82.
550 Using another implementation of the make program or an earlier version of
551 GNU make to build GDB or GDBserver is not supported.
553 * Building GDB now requires GNU readline >= 7.0.
555 GDB now bundles GNU readline 8.0, but if you choose to use
556 --with-system-readline, only readline >= 7.0 can be used.
558 * The TUI SingleKey keymap is now named "SingleKey". This can be used
559 from .inputrc to bind keys in this keymap. This feature is only
560 available when gdb is built against GNU readline 8.0 or later.
562 * Removed targets and native configurations
564 GDB no longer supports debugging the Cell Broadband Engine. This includes
565 both debugging standalone Cell/B.E. SPU applications and integrated debugging
566 of Cell/B.E. applications that use both the PPU and SPU architectures.
572 * Removed targets and native configurations
574 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
577 *** Changes in GDB 8.3
579 * GDB and GDBserver now support access to additional registers on
580 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
583 * GDB now has experimental support for the compilation and injection of
584 C++ source code into the inferior. This beta release does not include
585 support for several language features, such as templates, constructors,
588 This feature requires GCC 7.1 or higher built with libcp1.so
591 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
592 can be passed using the '[ADDRESS]:PORT' notation, or the regular
593 'ADDRESS:PORT' method.
595 * DWARF index cache: GDB can now automatically save indices of DWARF
596 symbols on disk to speed up further loading of the same binaries.
598 * Ada task switching is now supported on aarch64-elf targets when
599 debugging a program using the Ravenscar Profile. For more information,
600 see the "Tasking Support when using the Ravenscar Profile" section
601 in the GDB user manual.
603 * GDB in batch mode now exits with status 1 if the last command to be
606 * The RISC-V target now supports target descriptions.
608 * System call catchpoints now support system call aliases on FreeBSD.
609 When the ABI of a system call changes in FreeBSD, this is
610 implemented by leaving a compatibility system call using the old ABI
611 at the existing number and allocating a new system call number for
612 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
613 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
614 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
615 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
616 so that a system call catchpoint for the 'kevent' system call will
617 catch invocations of both the 'kevent' and 'freebsd11_kevent'
618 binaries. This ensures that 'kevent' system calls are caught for
619 binaries using either the old or new ABIs.
621 * Terminal styling is now available for the CLI and the TUI. GNU
622 Source Highlight can additionally be used to provide styling of
623 source code snippets. See the "set style" commands, below, for more
626 * Removed support for old demangling styles arm, edg, gnu, hp and
631 set debug compile-cplus-types
632 show debug compile-cplus-types
633 Control the display of debug output about type conversion in the
634 C++ compile feature. Commands have no effect while compiliong
639 Control whether debug output about files/functions skipping is
642 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
643 Apply a command to some frames.
644 FLAG arguments allow to control what output to produce and how to handle
645 errors raised when applying COMMAND to a frame.
648 Apply a command to all threads (ignoring errors and empty output).
649 Shortcut for 'thread apply all -s COMMAND'.
652 Apply a command to all frames (ignoring errors and empty output).
653 Shortcut for 'frame apply all -s COMMAND'.
656 Apply a command to all frames of all threads (ignoring errors and empty
658 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
660 maint set dwarf unwinders (on|off)
661 maint show dwarf unwinders
662 Control whether DWARF unwinders can be used.
665 Display a list of open files for a process.
669 Changes to the "frame", "select-frame", and "info frame" CLI commands.
670 These commands all now take a frame specification which
671 is either a frame level, or one of the keywords 'level', 'address',
672 'function', or 'view' followed by a parameter. Selecting a frame by
673 address, or viewing a frame outside the current backtrace now
674 requires the use of a keyword. Selecting a frame by level is
675 unchanged. The MI comment "-stack-select-frame" is unchanged.
677 target remote FILENAME
678 target extended-remote FILENAME
679 If FILENAME is a Unix domain socket, GDB will attempt to connect
680 to this socket instead of opening FILENAME as a character device.
682 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
683 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
684 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
685 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
686 These commands can now print only the searched entities
687 matching the provided regexp(s), giving a condition
688 on the entity names or entity types. The flag -q disables
689 printing headers or informations messages.
695 These commands now determine the syntax for the shown entities
696 according to the language chosen by `set language'. In particular,
697 `set language auto' means to automatically choose the language of
700 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
701 The 'thread apply' command accepts new FLAG arguments.
702 FLAG arguments allow to control what output to produce and how to handle
703 errors raised when applying COMMAND to a thread.
705 set tui tab-width NCHARS
706 show tui tab-width NCHARS
707 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
709 set style enabled [on|off]
711 Enable or disable terminal styling. Styling is enabled by default
712 on most hosts, but disabled by default when in batch mode.
714 set style sources [on|off]
716 Enable or disable source code styling. Source code styling is
717 enabled by default, but only takes effect if styling in general is
718 enabled, and if GDB was linked with GNU Source Highlight.
720 set style filename foreground COLOR
721 set style filename background COLOR
722 set style filename intensity VALUE
723 Control the styling of file names.
725 set style function foreground COLOR
726 set style function background COLOR
727 set style function intensity VALUE
728 Control the styling of function names.
730 set style variable foreground COLOR
731 set style variable background COLOR
732 set style variable intensity VALUE
733 Control the styling of variable names.
735 set style address foreground COLOR
736 set style address background COLOR
737 set style address intensity VALUE
738 Control the styling of addresses.
742 ** The '-data-disassemble' MI command now accepts an '-a' option to
743 disassemble the whole function surrounding the given program
744 counter value or function name. Support for this feature can be
745 verified by using the "-list-features" command, which should
746 contain "data-disassemble-a-option".
748 ** Command responses and notifications that include a frame now include
749 the frame's architecture in a new "arch" attribute.
751 * New native configurations
753 GNU/Linux/RISC-V riscv*-*-linux*
754 FreeBSD/riscv riscv*-*-freebsd*
758 GNU/Linux/RISC-V riscv*-*-linux*
760 CSKY GNU/LINUX csky*-*-linux
761 FreeBSD/riscv riscv*-*-freebsd*
763 GNU/Linux/OpenRISC or1k*-*-linux*
767 GDB no longer supports native debugging on versions of MS-Windows
772 ** GDB no longer supports Python versions less than 2.6.
774 ** The gdb.Inferior type has a new 'progspace' property, which is the program
775 space associated to that inferior.
777 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
778 of objfiles associated to that program space.
780 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
781 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
784 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
785 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
786 correct and did not work properly.
788 ** The gdb.Value type has a new constructor, which is used to construct a
789 gdb.Value from a Python buffer object and a gdb.Type.
795 Enable or disable the undefined behavior sanitizer. This is
796 disabled by default, but passing --enable-ubsan=yes or
797 --enable-ubsan=auto to configure will enable it. Enabling this can
798 cause a performance penalty. The undefined behavior sanitizer was
799 first introduced in GCC 4.9.
801 *** Changes in GDB 8.2
803 * The 'set disassembler-options' command now supports specifying options
806 * The 'symbol-file' command now accepts an '-o' option to add a relative
807 offset to all sections.
809 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
810 a relative offset to all sections, but it allows to override the load
811 address of individual sections using '-s'.
813 * The 'add-symbol-file' command no longer requires the second argument
814 (address of the text section).
816 * The endianness used with the 'set endian auto' mode in the absence of
817 an executable selected for debugging is now the last endianness chosen
818 either by one of the 'set endian big' and 'set endian little' commands
819 or by inferring from the last executable used, rather than the startup
822 * The pager now allows a "c" response, meaning to disable the pager
823 for the rest of the current command.
825 * The commands 'info variables/functions/types' now show the source line
826 numbers of symbol definitions when available.
828 * 'info proc' now works on running processes on FreeBSD systems and core
829 files created on FreeBSD systems.
831 * C expressions can now use _Alignof, and C++ expressions can now use
834 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
835 the vector length while the process is running.
841 Control display of debugging info regarding the FreeBSD native target.
843 set|show varsize-limit
844 This new setting allows the user to control the maximum size of Ada
845 objects being printed when those objects have a variable type,
846 instead of that maximum size being hardcoded to 65536 bytes.
848 set|show record btrace cpu
849 Controls the processor to be used for enabling errata workarounds for
852 maint check libthread-db
853 Run integrity checks on the current inferior's thread debugging
856 maint set check-libthread-db (on|off)
857 maint show check-libthread-db
858 Control whether to run integrity checks on inferior specific thread
859 debugging libraries as they are loaded. The default is not to
864 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
866 ** The commands attached to a breakpoint can be set by assigning to
867 the breakpoint's "commands" field.
869 ** gdb.execute can now execute multi-line gdb commands.
871 ** The new functions gdb.convenience_variable and
872 gdb.set_convenience_variable can be used to get and set the value
873 of convenience variables.
875 ** A gdb.Parameter will no longer print the "set" help text on an
876 ordinary "set"; instead by default a "set" will be silent unless
877 the get_set_string method returns a non-empty string.
881 RiscV ELF riscv*-*-elf
883 * Removed targets and native configurations
885 m88k running OpenBSD m88*-*-openbsd*
886 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
887 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
888 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
890 * Aarch64/Linux hardware watchpoints improvements
892 Hardware watchpoints on unaligned addresses are now properly
893 supported when running Linux kernel 4.10 or higher: read and access
894 watchpoints are no longer spuriously missed, and all watchpoints
895 lengths between 1 and 8 bytes are supported. On older kernels,
896 watchpoints set on unaligned addresses are no longer missed, with
897 the tradeoff that there is a possibility of false hits being
902 --enable-codesign=CERT
903 This can be used to invoke "codesign -s CERT" after building gdb.
904 This option is useful on macOS, where code signing is required for
905 gdb to work properly.
907 --disable-gdbcli has been removed
908 This is now silently accepted, but does nothing.
910 *** Changes in GDB 8.1
912 * GDB now supports dynamically creating arbitrary register groups specified
913 in XML target descriptions. This allows for finer grain grouping of
914 registers on systems with a large amount of registers.
916 * The 'ptype' command now accepts a '/o' flag, which prints the
917 offsets and sizes of fields in a struct, like the pahole(1) tool.
919 * New "--readnever" command line option instructs GDB to not read each
920 symbol file's symbolic debug information. This makes startup faster
921 but at the expense of not being able to perform symbolic debugging.
922 This option is intended for use cases where symbolic debugging will
923 not be used, e.g., when you only need to dump the debuggee's core.
925 * GDB now uses the GNU MPFR library, if available, to emulate target
926 floating-point arithmetic during expression evaluation when the target
927 uses different floating-point formats than the host. At least version
928 3.1 of GNU MPFR is required.
930 * GDB now supports access to the guarded-storage-control registers and the
931 software-based guarded-storage broadcast control registers on IBM z14.
933 * On Unix systems, GDB now supports transmitting environment variables
934 that are to be set or unset to GDBserver. These variables will
935 affect the environment to be passed to the remote inferior.
937 To inform GDB of environment variables that are to be transmitted to
938 GDBserver, use the "set environment" command. Only user set
939 environment variables are sent to GDBserver.
941 To inform GDB of environment variables that are to be unset before
942 the remote inferior is started by the GDBserver, use the "unset
943 environment" command.
945 * Completion improvements
947 ** GDB can now complete function parameters in linespecs and
948 explicit locations without quoting. When setting breakpoints,
949 quoting around functions names to help with TAB-completion is
950 generally no longer necessary. For example, this now completes
953 (gdb) b function(in[TAB]
954 (gdb) b function(int)
956 Related, GDB is no longer confused with completing functions in
957 C++ anonymous namespaces:
960 (gdb) b (anonymous namespace)::[TAB][TAB]
961 (anonymous namespace)::a_function()
962 (anonymous namespace)::b_function()
964 ** GDB now has much improved linespec and explicit locations TAB
965 completion support, that better understands what you're
966 completing and offers better suggestions. For example, GDB no
967 longer offers data symbols as possible completions when you're
968 setting a breakpoint.
970 ** GDB now TAB-completes label symbol names.
972 ** The "complete" command now mimics TAB completion accurately.
974 * New command line options (gcore)
977 Dump all memory mappings.
979 * Breakpoints on C++ functions are now set on all scopes by default
981 By default, breakpoints on functions/methods are now interpreted as
982 specifying all functions with the given name ignoring missing
983 leading scopes (namespaces and classes).
985 For example, assuming a C++ program with symbols named:
990 both commands "break func()" and "break B::func()" set a breakpoint
993 You can use the new flag "-qualified" to override this. This makes
994 GDB interpret the specified function name as a complete
995 fully-qualified name instead. For example, using the same C++
996 program, the "break -q B::func" command sets a breakpoint on
997 "B::func", only. A parameter has been added to the Python
998 gdb.Breakpoint constructor to achieve the same result when creating
999 a breakpoint from Python.
1001 * Breakpoints on functions marked with C++ ABI tags
1003 GDB can now set breakpoints on functions marked with C++ ABI tags
1004 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1005 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1007 Functions with a C++11 abi tag are demangled/displayed like this:
1009 function[abi:cxx11](int)
1012 You can now set a breakpoint on such functions simply as if they had
1015 (gdb) b function(int)
1017 Or if you need to disambiguate between tags, like:
1019 (gdb) b function[abi:other_tag](int)
1021 Tab completion was adjusted accordingly as well.
1025 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1026 gdb.new_thread are emitted. See the manual for further
1027 description of these.
1029 ** A new function, "gdb.rbreak" has been added to the Python API.
1030 This function allows the setting of a large number of breakpoints
1031 via a regex pattern in Python. See the manual for further details.
1033 ** Python breakpoints can now accept explicit locations. See the
1034 manual for a further description of this feature.
1037 * New features in the GDB remote stub, GDBserver
1039 ** GDBserver is now able to start inferior processes with a
1040 specified initial working directory.
1042 The user can set the desired working directory to be used from
1043 GDB using the new "set cwd" command.
1045 ** New "--selftest" command line option runs some GDBserver self
1046 tests. These self tests are disabled in releases.
1048 ** On Unix systems, GDBserver now does globbing expansion and variable
1049 substitution in inferior command line arguments.
1051 This is done by starting inferiors using a shell, like GDB does.
1052 See "set startup-with-shell" in the user manual for how to disable
1053 this from GDB when using "target extended-remote". When using
1054 "target remote", you can disable the startup with shell by using the
1055 new "--no-startup-with-shell" GDBserver command line option.
1057 ** On Unix systems, GDBserver now supports receiving environment
1058 variables that are to be set or unset from GDB. These variables
1059 will affect the environment to be passed to the inferior.
1061 * When catching an Ada exception raised with a message, GDB now prints
1062 the message in the catchpoint hit notification. In GDB/MI mode, that
1063 information is provided as an extra field named "exception-message"
1064 in the *stopped notification.
1066 * Trait objects can now be inspected When debugging Rust code. This
1067 requires compiler support which will appear in Rust 1.24.
1069 * New remote packets
1071 QEnvironmentHexEncoded
1072 Inform GDBserver of an environment variable that is to be passed to
1073 the inferior when starting it.
1076 Inform GDBserver of an environment variable that is to be unset
1077 before starting the remote inferior.
1080 Inform GDBserver that the environment should be reset (i.e.,
1081 user-set environment variables should be unset).
1084 Indicates whether the inferior must be started with a shell or not.
1087 Tell GDBserver that the inferior to be started should use a specific
1090 * The "maintenance print c-tdesc" command now takes an optional
1091 argument which is the file name of XML target description.
1093 * The "maintenance selftest" command now takes an optional argument to
1094 filter the tests to be run.
1096 * The "enable", and "disable" commands now accept a range of
1097 breakpoint locations, e.g. "enable 1.3-5".
1102 Set and show the current working directory for the inferior.
1104 set|show compile-gcc
1105 Set and show compilation command used for compiling and injecting code
1106 with the 'compile' commands.
1108 set debug separate-debug-file
1109 show debug separate-debug-file
1110 Control the display of debug output about separate debug file search.
1112 set dump-excluded-mappings
1113 show dump-excluded-mappings
1114 Control whether mappings marked with the VM_DONTDUMP flag should be
1115 dumped when generating a core file.
1117 maint info selftests
1118 List the registered selftests.
1121 Start the debugged program stopping at the first instruction.
1124 Control display of debugging messages related to OpenRISC targets.
1126 set|show print type nested-type-limit
1127 Set and show the limit of nesting level for nested types that the
1128 type printer will show.
1130 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1133 * Safer/improved support for debugging with no debug info
1135 GDB no longer assumes functions with no debug information return
1138 This means that GDB now refuses to call such functions unless you
1139 tell it the function's type, by either casting the call to the
1140 declared return type, or by casting the function to a function
1141 pointer of the right type, and calling that:
1143 (gdb) p getenv ("PATH")
1144 'getenv' has unknown return type; cast the call to its declared return type
1145 (gdb) p (char *) getenv ("PATH")
1146 $1 = 0x7fffffffe "/usr/local/bin:/"...
1147 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1148 $2 = 0x7fffffffe "/usr/local/bin:/"...
1150 Similarly, GDB no longer assumes that global variables with no debug
1151 info have type 'int', and refuses to print the variable's value
1152 unless you tell it the variable's type:
1155 'var' has unknown type; cast it to its declared type
1159 * New native configurations
1161 FreeBSD/aarch64 aarch64*-*-freebsd*
1162 FreeBSD/arm arm*-*-freebsd*
1166 FreeBSD/aarch64 aarch64*-*-freebsd*
1167 FreeBSD/arm arm*-*-freebsd*
1168 OpenRISC ELF or1k*-*-elf
1170 * Removed targets and native configurations
1172 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1174 *** Changes in GDB 8.0
1176 * GDB now supports access to the PKU register on GNU/Linux. The register is
1177 added by the Memory Protection Keys for Userspace feature which will be
1178 available in future Intel CPUs.
1180 * GDB now supports C++11 rvalue references.
1184 ** New functions to start, stop and access a running btrace recording.
1185 ** Rvalue references are now supported in gdb.Type.
1187 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1190 * Building GDB and GDBserver now requires a C++11 compiler.
1192 For example, GCC 4.8 or later.
1194 It is no longer possible to build GDB or GDBserver with a C
1195 compiler. The --disable-build-with-cxx configure option has been
1198 * Building GDB and GDBserver now requires GNU make >= 3.81.
1200 It is no longer supported to build GDB or GDBserver with another
1201 implementation of the make program or an earlier version of GNU make.
1203 * Native debugging on MS-Windows supports command-line redirection
1205 Command-line arguments used for starting programs on MS-Windows can
1206 now include redirection symbols supported by native Windows shells,
1207 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1208 as "run", "start", and "set args", as well as the corresponding MI
1211 * Support for thread names on MS-Windows.
1213 GDB now catches and handles the special exception that programs
1214 running on MS-Windows use to assign names to threads in the
1217 * Support for Java programs compiled with gcj has been removed.
1219 * User commands now accept an unlimited number of arguments.
1220 Previously, only up to 10 was accepted.
1222 * The "eval" command now expands user-defined command arguments.
1224 This makes it easier to process a variable number of arguments:
1229 eval "print $arg%d", $i
1234 * Target descriptions can now describe registers for sparc32 and sparc64.
1236 * GDB now supports DWARF version 5 (debug information format).
1237 Its .debug_names index is not yet supported.
1239 * New native configurations
1241 FreeBSD/mips mips*-*-freebsd
1245 Synopsys ARC arc*-*-elf32
1246 FreeBSD/mips mips*-*-freebsd
1248 * Removed targets and native configurations
1250 Alpha running FreeBSD alpha*-*-freebsd*
1251 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1256 Erases all the flash memory regions reported by the target.
1258 maint print arc arc-instruction address
1259 Print internal disassembler information about instruction at a given address.
1263 set disassembler-options
1264 show disassembler-options
1265 Controls the passing of target specific information to the disassembler.
1266 If it is necessary to specify more than one disassembler option then
1267 multiple options can be placed together into a comma separated list.
1268 The default value is the empty string. Currently, the only supported
1269 targets are ARM, PowerPC and S/390.
1274 Erases all the flash memory regions reported by the target. This is
1275 equivalent to the CLI command flash-erase.
1277 -file-list-shared-libraries
1278 List the shared libraries in the program. This is
1279 equivalent to the CLI command "info shared".
1282 Catchpoints stopping the program when Ada exceptions are
1283 handled. This is equivalent to the CLI command "catch handlers".
1285 *** Changes in GDB 7.12
1287 * GDB and GDBserver now build with a C++ compiler by default.
1289 The --enable-build-with-cxx configure option is now enabled by
1290 default. One must now explicitly configure with
1291 --disable-build-with-cxx in order to build with a C compiler. This
1292 option will be removed in a future release.
1294 * GDBserver now supports recording btrace without maintaining an active
1297 * GDB now supports a negative repeat count in the 'x' command to examine
1298 memory backward from the given address. For example:
1301 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1302 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1303 (gdb) x/-5i 0x0000000000400580
1304 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1305 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1306 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1307 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1308 0x40057b <main(int, char**)+25>:
1309 callq 0x400536 <Func1(int, char const*)>
1311 * Fortran: Support structures with fields of dynamic types and
1312 arrays of dynamic types.
1314 * The symbol dumping maintenance commands have new syntax.
1315 maint print symbols [-pc address] [--] [filename]
1316 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1317 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1318 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1319 maint print msymbols [-objfile objfile] [--] [filename]
1321 * GDB now supports multibit bitfields and enums in target register
1324 * New Python-based convenience function $_as_string(val), which returns
1325 the textual representation of a value. This function is especially
1326 useful to obtain the text label of an enum value.
1328 * Intel MPX bound violation handling.
1330 Segmentation faults caused by a Intel MPX boundary violation
1331 now display the kind of violation (upper or lower), the memory
1332 address accessed and the memory bounds, along with the usual
1333 signal received and code location.
1337 Program received signal SIGSEGV, Segmentation fault
1338 Upper bound violation while accessing address 0x7fffffffc3b3
1339 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1340 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1342 * Rust language support.
1343 GDB now supports debugging programs written in the Rust programming
1344 language. See https://www.rust-lang.org/ for more information about
1347 * Support for running interpreters on specified input/output devices
1349 GDB now supports a new mechanism that allows frontends to provide
1350 fully featured GDB console views, as a better alternative to
1351 building such views on top of the "-interpreter-exec console"
1352 command. See the new "new-ui" command below. With that command,
1353 frontends can now start GDB in the traditional command-line mode
1354 running in an embedded terminal emulator widget, and create a
1355 separate MI interpreter running on a specified i/o device. In this
1356 way, GDB handles line editing, history, tab completion, etc. in the
1357 console all by itself, and the GUI uses the separate MI interpreter
1358 for its own control and synchronization, invisible to the command
1361 * The "catch syscall" command catches groups of related syscalls.
1363 The "catch syscall" command now supports catching a group of related
1364 syscalls using the 'group:' or 'g:' prefix.
1369 skip -gfile file-glob-pattern
1370 skip -function function
1371 skip -rfunction regular-expression
1372 A generalized form of the skip command, with new support for
1373 glob-style file names and regular expressions for function names.
1374 Additionally, a file spec and a function spec may now be combined.
1376 maint info line-table REGEXP
1377 Display the contents of GDB's internal line table data struture.
1380 Run any GDB unit tests that were compiled in.
1383 Start a new user interface instance running INTERP as interpreter,
1384 using the TTY file for input/output.
1388 ** gdb.Breakpoint objects have a new attribute "pending", which
1389 indicates whether the breakpoint is pending.
1390 ** Three new breakpoint-related events have been added:
1391 gdb.breakpoint_created, gdb.breakpoint_modified, and
1392 gdb.breakpoint_deleted.
1394 signal-event EVENTID
1395 Signal ("set") the given MS-Windows event object. This is used in
1396 conjunction with the Windows JIT debugging (AeDebug) support, where
1397 the OS suspends a crashing process until a debugger can attach to
1398 it. Resuming the crashing process, in order to debug it, is done by
1399 signalling an event.
1401 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1402 was added in GDBserver, including JIT compiling fast tracepoint's
1403 conditional expression bytecode into native code.
1405 * Support for various remote target protocols and ROM monitors has
1408 target m32rsdi Remote M32R debugging over SDI
1409 target mips MIPS remote debugging protocol
1410 target pmon PMON ROM monitor
1411 target ddb NEC's DDB variant of PMON for Vr4300
1412 target rockhopper NEC RockHopper variant of PMON
1413 target lsi LSI variant of PMO
1415 * Support for tracepoints and fast tracepoints on powerpc-linux,
1416 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1417 including JIT compiling fast tracepoint's conditional expression
1418 bytecode into native code.
1420 * MI async record =record-started now includes the method and format used for
1421 recording. For example:
1423 =record-started,thread-group="i1",method="btrace",format="bts"
1425 * MI async record =thread-selected now includes the frame field. For example:
1427 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1431 Andes NDS32 nds32*-*-elf
1433 *** Changes in GDB 7.11
1435 * GDB now supports debugging kernel-based threads on FreeBSD.
1437 * Per-inferior thread numbers
1439 Thread numbers are now per inferior instead of global. If you're
1440 debugging multiple inferiors, GDB displays thread IDs using a
1441 qualified INF_NUM.THR_NUM form. For example:
1445 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1446 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1447 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1448 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1450 As consequence, thread numbers as visible in the $_thread
1451 convenience variable and in Python's InferiorThread.num attribute
1452 are no longer unique between inferiors.
1454 GDB now maintains a second thread ID per thread, referred to as the
1455 global thread ID, which is the new equivalent of thread numbers in
1456 previous releases. See also $_gthread below.
1458 For backwards compatibility, MI's thread IDs always refer to global
1461 * Commands that accept thread IDs now accept the qualified
1462 INF_NUM.THR_NUM form as well. For example:
1465 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1468 * In commands that accept a list of thread IDs, you can now refer to
1469 all threads of an inferior using a star wildcard. GDB accepts
1470 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1471 refer to all threads of the current inferior. For example, "info
1474 * You can use "info threads -gid" to display the global thread ID of
1477 * The new convenience variable $_gthread holds the global number of
1480 * The new convenience variable $_inferior holds the number of the
1483 * GDB now displays the ID and name of the thread that hit a breakpoint
1484 or received a signal, if your program is multi-threaded. For
1487 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1488 Thread 1 "main" received signal SIGINT, Interrupt.
1490 * Record btrace now supports non-stop mode.
1492 * Support for tracepoints on aarch64-linux was added in GDBserver.
1494 * The 'record instruction-history' command now indicates speculative execution
1495 when using the Intel Processor Trace recording format.
1497 * GDB now allows users to specify explicit locations, bypassing
1498 the linespec parser. This feature is also available to GDB/MI
1501 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1502 GDB now is able to debug both AArch64 applications and ARM applications
1505 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1506 including JIT compiling fast tracepoint's conditional expression bytecode
1509 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1511 * "info threads", "info inferiors", "info display", "info checkpoints"
1512 and "maint info program-spaces" now list the corresponding items in
1513 ascending ID order, for consistency with all other "info" commands.
1515 * In Ada, the overloads selection menu has been enhanced to display the
1516 parameter types and the return types for the matching overloaded subprograms.
1520 maint set target-non-stop (on|off|auto)
1521 maint show target-non-stop
1522 Control whether GDB targets always operate in non-stop mode even if
1523 "set non-stop" is "off". The default is "auto", meaning non-stop
1524 mode is enabled if supported by the target.
1526 maint set bfd-sharing
1527 maint show bfd-sharing
1528 Control the reuse of bfd objects.
1531 show debug bfd-cache
1532 Control display of debugging info regarding bfd caching.
1536 Control display of debugging info regarding FreeBSD threads.
1538 set remote multiprocess-extensions-packet
1539 show remote multiprocess-extensions-packet
1540 Set/show the use of the remote protocol multiprocess extensions.
1542 set remote thread-events
1543 show remote thread-events
1544 Set/show the use of thread create/exit events.
1546 set ada print-signatures on|off
1547 show ada print-signatures"
1548 Control whether parameter types and return types are displayed in overloads
1549 selection menus. It is activaled (@code{on}) by default.
1553 Controls the maximum size of memory, in bytes, that GDB will
1554 allocate for value contents. Prevents incorrect programs from
1555 causing GDB to allocate overly large buffers. Default is 64k.
1557 * The "disassemble" command accepts a new modifier: /s.
1558 It prints mixed source+disassembly like /m with two differences:
1559 - disassembled instructions are now printed in program order, and
1560 - and source for all relevant files is now printed.
1561 The "/m" option is now considered deprecated: its "source-centric"
1562 output hasn't proved useful in practice.
1564 * The "record instruction-history" command accepts a new modifier: /s.
1565 It behaves exactly like /m and prints mixed source+disassembly.
1567 * The "set scheduler-locking" command supports a new mode "replay".
1568 It behaves like "off" in record mode and like "on" in replay mode.
1570 * Support for various ROM monitors has been removed:
1572 target dbug dBUG ROM monitor for Motorola ColdFire
1573 target picobug Motorola picobug monitor
1574 target dink32 DINK32 ROM monitor for PowerPC
1575 target m32r Renesas M32R/D ROM monitor
1576 target mon2000 mon2000 ROM monitor
1577 target ppcbug PPCBUG ROM monitor for PowerPC
1579 * Support for reading/writing memory and extracting values on architectures
1580 whose memory is addressable in units of any integral multiple of 8 bits.
1583 Allows to break when an Ada exception is handled.
1585 * New remote packets
1588 Indicates that an exec system call was executed.
1590 exec-events feature in qSupported
1591 The qSupported packet allows GDB to request support for exec
1592 events using the new 'gdbfeature' exec-event, and the qSupported
1593 response can contain the corresponding 'stubfeature'. Set and
1594 show commands can be used to display whether these features are enabled.
1597 Equivalent to interrupting with the ^C character, but works in
1600 thread created stop reason (T05 create:...)
1601 Indicates that the thread was just created and is stopped at entry.
1603 thread exit stop reply (w exitcode;tid)
1604 Indicates that the thread has terminated.
1607 Enables/disables thread create and exit event reporting. For
1608 example, this is used in non-stop mode when GDB stops a set of
1609 threads and synchronously waits for the their corresponding stop
1610 replies. Without exit events, if one of the threads exits, GDB
1611 would hang forever not knowing that it should no longer expect a
1612 stop for that same thread.
1615 Indicates that there are no resumed threads left in the target (all
1616 threads are stopped). The remote stub reports support for this stop
1617 reply to GDB's qSupported query.
1620 Enables/disables catching syscalls from the inferior process.
1621 The remote stub reports support for this packet to GDB's qSupported query.
1623 syscall_entry stop reason
1624 Indicates that a syscall was just called.
1626 syscall_return stop reason
1627 Indicates that a syscall just returned.
1629 * Extended-remote exec events
1631 ** GDB now has support for exec events on extended-remote Linux targets.
1632 For such targets with Linux kernels 2.5.46 and later, this enables
1633 follow-exec-mode and exec catchpoints.
1635 set remote exec-event-feature-packet
1636 show remote exec-event-feature-packet
1637 Set/show the use of the remote exec event feature.
1639 * Thread names in remote protocol
1641 The reply to qXfer:threads:read may now include a name attribute for each
1644 * Target remote mode fork and exec events
1646 ** GDB now has support for fork and exec events on target remote mode
1647 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1648 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1649 fork and exec catchpoints.
1651 * Remote syscall events
1653 ** GDB now has support for catch syscall on remote Linux targets,
1654 currently enabled on x86/x86_64 architectures.
1656 set remote catch-syscall-packet
1657 show remote catch-syscall-packet
1658 Set/show the use of the remote catch syscall feature.
1662 ** The -var-set-format command now accepts the zero-hexadecimal
1663 format. It outputs data in hexadecimal format with zero-padding on the
1668 ** gdb.InferiorThread objects have a new attribute "global_num",
1669 which refers to the thread's global thread ID. The existing
1670 "num" attribute now refers to the thread's per-inferior number.
1671 See "Per-inferior thread numbers" above.
1672 ** gdb.InferiorThread objects have a new attribute "inferior", which
1673 is the Inferior object the thread belongs to.
1675 *** Changes in GDB 7.10
1677 * Support for process record-replay and reverse debugging on aarch64*-linux*
1678 targets has been added. GDB now supports recording of A64 instruction set
1679 including advance SIMD instructions.
1681 * Support for Sun's version of the "stabs" debug file format has been removed.
1683 * GDB now honors the content of the file /proc/PID/coredump_filter
1684 (PID is the process ID) on GNU/Linux systems. This file can be used
1685 to specify the types of memory mappings that will be included in a
1686 corefile. For more information, please refer to the manual page of
1687 "core(5)". GDB also has a new command: "set use-coredump-filter
1688 on|off". It allows to set whether GDB will read the content of the
1689 /proc/PID/coredump_filter file when generating a corefile.
1691 * The "info os" command on GNU/Linux can now display information on
1693 "info os cpus" Listing of all cpus/cores on the system
1695 * GDB has two new commands: "set serial parity odd|even|none" and
1696 "show serial parity". These allows to set or show parity for the
1699 * The "info source" command now displays the producer string if it was
1700 present in the debug info. This typically includes the compiler version
1701 and may include things like its command line arguments.
1703 * The "info dll", an alias of the "info sharedlibrary" command,
1704 is now available on all platforms.
1706 * Directory names supplied to the "set sysroot" commands may be
1707 prefixed with "target:" to tell GDB to access shared libraries from
1708 the target system, be it local or remote. This replaces the prefix
1709 "remote:". The default sysroot has been changed from "" to
1710 "target:". "remote:" is automatically converted to "target:" for
1711 backward compatibility.
1713 * The system root specified by "set sysroot" will be prepended to the
1714 filename of the main executable (if reported to GDB as absolute by
1715 the operating system) when starting processes remotely, and when
1716 attaching to already-running local or remote processes.
1718 * GDB now supports automatic location and retrieval of executable
1719 files from remote targets. Remote debugging can now be initiated
1720 using only a "target remote" or "target extended-remote" command
1721 (no "set sysroot" or "file" commands are required). See "New remote
1724 * The "dump" command now supports verilog hex format.
1726 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1728 * On GNU/Linux, GDB and gdbserver are now able to access executable
1729 and shared library files without a "set sysroot" command when
1730 attaching to processes running in different mount namespaces from
1731 the debugger. This makes it possible to attach to processes in
1732 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1733 See "New remote packets" below.
1735 * The "tui reg" command now provides completion for all of the
1736 available register groups, including target specific groups.
1738 * The HISTSIZE environment variable is no longer read when determining
1739 the size of GDB's command history. GDB now instead reads the dedicated
1740 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1741 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1746 ** Memory ports can now be unbuffered.
1750 ** gdb.Objfile objects have a new attribute "username",
1751 which is the name of the objfile as specified by the user,
1752 without, for example, resolving symlinks.
1753 ** You can now write frame unwinders in Python.
1754 ** gdb.Type objects have a new method "optimized_out",
1755 returning optimized out gdb.Value instance of this type.
1756 ** gdb.Value objects have new methods "reference_value" and
1757 "const_value" which return a reference to the value and a
1758 "const" version of the value respectively.
1762 maint print symbol-cache
1763 Print the contents of the symbol cache.
1765 maint print symbol-cache-statistics
1766 Print statistics of symbol cache usage.
1768 maint flush-symbol-cache
1769 Flush the contents of the symbol cache.
1773 Start branch trace recording using Branch Trace Store (BTS) format.
1776 Evaluate expression by using the compiler and print result.
1780 Explicit commands for enabling and disabling tui mode.
1783 set mpx bound on i386 and amd64
1784 Support for bound table investigation on Intel MPX enabled applications.
1788 Start branch trace recording using Intel Processor Trace format.
1791 Print information about branch tracing internals.
1793 maint btrace packet-history
1794 Print the raw branch tracing data.
1796 maint btrace clear-packet-history
1797 Discard the stored raw branch tracing data.
1800 Discard all branch tracing data. It will be fetched and processed
1801 anew by the next "record" command.
1806 Renamed from "set debug dwarf2-die".
1807 show debug dwarf-die
1808 Renamed from "show debug dwarf2-die".
1810 set debug dwarf-read
1811 Renamed from "set debug dwarf2-read".
1812 show debug dwarf-read
1813 Renamed from "show debug dwarf2-read".
1815 maint set dwarf always-disassemble
1816 Renamed from "maint set dwarf2 always-disassemble".
1817 maint show dwarf always-disassemble
1818 Renamed from "maint show dwarf2 always-disassemble".
1820 maint set dwarf max-cache-age
1821 Renamed from "maint set dwarf2 max-cache-age".
1822 maint show dwarf max-cache-age
1823 Renamed from "maint show dwarf2 max-cache-age".
1825 set debug dwarf-line
1826 show debug dwarf-line
1827 Control display of debugging info regarding DWARF line processing.
1830 show max-completions
1831 Set the maximum number of candidates to be considered during
1832 completion. The default value is 200. This limit allows GDB
1833 to avoid generating large completion lists, the computation of
1834 which can cause the debugger to become temporarily unresponsive.
1836 set history remove-duplicates
1837 show history remove-duplicates
1838 Control the removal of duplicate history entries.
1840 maint set symbol-cache-size
1841 maint show symbol-cache-size
1842 Control the size of the symbol cache.
1844 set|show record btrace bts buffer-size
1845 Set and show the size of the ring buffer used for branch tracing in
1847 The obtained size may differ from the requested size. Use "info
1848 record" to see the obtained buffer size.
1850 set debug linux-namespaces
1851 show debug linux-namespaces
1852 Control display of debugging info regarding Linux namespaces.
1854 set|show record btrace pt buffer-size
1855 Set and show the size of the ring buffer used for branch tracing in
1856 Intel Processor Trace format.
1857 The obtained size may differ from the requested size. Use "info
1858 record" to see the obtained buffer size.
1860 maint set|show btrace pt skip-pad
1861 Set and show whether PAD packets are skipped when computing the
1864 * The command 'thread apply all' can now support new option '-ascending'
1865 to call its specified command for all threads in ascending order.
1867 * Python/Guile scripting
1869 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1870 special section named `.debug_gdb_scripts'.
1872 * New remote packets
1874 qXfer:btrace-conf:read
1875 Return the branch trace configuration for the current thread.
1877 Qbtrace-conf:bts:size
1878 Set the requested ring buffer size for branch tracing in BTS format.
1881 Enable Intel Procesor Trace-based branch tracing for the current
1882 process. The remote stub reports support for this packet to GDB's
1885 Qbtrace-conf:pt:size
1886 Set the requested ring buffer size for branch tracing in Intel Processor
1890 Indicates a memory breakpoint instruction was executed, irrespective
1891 of whether it was GDB that planted the breakpoint or the breakpoint
1892 is hardcoded in the program. This is required for correct non-stop
1896 Indicates the target stopped for a hardware breakpoint. This is
1897 required for correct non-stop mode operation.
1900 Return information about files on the remote system.
1902 qXfer:exec-file:read
1903 Return the full absolute name of the file that was executed to
1904 create a process running on the remote system.
1907 Select the filesystem on which vFile: operations with filename
1908 arguments will operate. This is required for GDB to be able to
1909 access files on remote targets where the remote stub does not
1910 share a common filesystem with the inferior(s).
1913 Indicates that a fork system call was executed.
1916 Indicates that a vfork system call was executed.
1918 vforkdone stop reason
1919 Indicates that a vfork child of the specified process has executed
1920 an exec or exit, allowing the vfork parent to resume execution.
1922 fork-events and vfork-events features in qSupported
1923 The qSupported packet allows GDB to request support for fork and
1924 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1925 and the qSupported response can contain the corresponding
1926 'stubfeatures'. Set and show commands can be used to display
1927 whether these features are enabled.
1929 * Extended-remote fork events
1931 ** GDB now has support for fork events on extended-remote Linux
1932 targets. For targets with Linux kernels 2.5.60 and later, this
1933 enables follow-fork-mode and detach-on-fork for both fork and
1934 vfork, as well as fork and vfork catchpoints.
1936 * The info record command now shows the recording format and the
1937 branch tracing configuration for the current thread when using
1938 the btrace record target.
1939 For the BTS format, it shows the ring buffer size.
1941 * GDB now has support for DTrace USDT (Userland Static Defined
1942 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1944 * GDB now supports access to vector registers on S/390 GNU/Linux
1947 * Removed command line options
1949 -xdb HP-UX XDB compatibility mode.
1951 * Removed targets and native configurations
1953 HP/PA running HP-UX hppa*-*-hpux*
1954 Itanium running HP-UX ia64-*-hpux*
1956 * New configure options
1959 This configure option allows the user to build GDB with support for
1960 Intel Processor Trace (default: auto). This requires libipt.
1962 --with-libipt-prefix=PATH
1963 Specify the path to the version of libipt that GDB should use.
1964 $PATH/include should contain the intel-pt.h header and
1965 $PATH/lib should contain the libipt.so library.
1967 *** Changes in GDB 7.9.1
1971 ** Xmethods can now specify a result type.
1973 *** Changes in GDB 7.9
1975 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1979 ** You can now access frame registers from Python scripts.
1980 ** New attribute 'producer' for gdb.Symtab objects.
1981 ** gdb.Objfile objects have a new attribute "progspace",
1982 which is the gdb.Progspace object of the containing program space.
1983 ** gdb.Objfile objects have a new attribute "owner".
1984 ** gdb.Objfile objects have a new attribute "build_id",
1985 which is the build ID generated when the file was built.
1986 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1987 ** A new event "gdb.clear_objfiles" has been added, triggered when
1988 selecting a new file to debug.
1989 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1990 ** New function gdb.lookup_objfile.
1992 New events which are triggered when GDB modifies the state of the
1995 ** gdb.events.inferior_call_pre: Function call is about to be made.
1996 ** gdb.events.inferior_call_post: Function call has just been made.
1997 ** gdb.events.memory_changed: A memory location has been altered.
1998 ** gdb.events.register_changed: A register has been altered.
2000 * New Python-based convenience functions:
2002 ** $_caller_is(name [, number_of_frames])
2003 ** $_caller_matches(regexp [, number_of_frames])
2004 ** $_any_caller_is(name [, number_of_frames])
2005 ** $_any_caller_matches(regexp [, number_of_frames])
2007 * GDB now supports the compilation and injection of source code into
2008 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2009 to compile the source code to object code, and if successful, inject
2010 and execute that code within the current context of the inferior.
2011 Currently the C language is supported. The commands used to
2012 interface with this new feature are:
2014 compile code [-raw|-r] [--] [source code]
2015 compile file [-raw|-r] filename
2019 demangle [-l language] [--] name
2020 Demangle "name" in the specified language, or the current language
2021 if elided. This command is renamed from the "maint demangle" command.
2022 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2023 as "maint demangler-warning".
2025 queue-signal signal-name-or-number
2026 Queue a signal to be delivered to the thread when it is resumed.
2028 add-auto-load-scripts-directory directory
2029 Add entries to the list of directories from which to load auto-loaded
2032 maint print user-registers
2033 List all currently available "user" registers.
2035 compile code [-r|-raw] [--] [source code]
2036 Compile, inject, and execute in the inferior the executable object
2037 code produced by compiling the provided source code.
2039 compile file [-r|-raw] filename
2040 Compile and inject into the inferior the executable object code
2041 produced by compiling the source code stored in the filename
2044 * On resume, GDB now always passes the signal the program had stopped
2045 for to the thread the signal was sent to, even if the user changed
2046 threads before resuming. Previously GDB would often (but not
2047 always) deliver the signal to the thread that happens to be current
2050 * Conversely, the "signal" command now consistently delivers the
2051 requested signal to the current thread. GDB now asks for
2052 confirmation if the program had stopped for a signal and the user
2053 switched threads meanwhile.
2055 * "breakpoint always-inserted" modes "off" and "auto" merged.
2057 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2058 won't remove breakpoints from the target until all threads stop,
2059 even in non-stop mode. The "auto" mode has been removed, and "off"
2060 is now the default mode.
2064 set debug symbol-lookup
2065 show debug symbol-lookup
2066 Control display of debugging info regarding symbol lookup.
2070 ** The -list-thread-groups command outputs an exit-code field for
2071 inferiors that have exited.
2075 MIPS SDE mips*-sde*-elf*
2079 Support for these obsolete configurations has been removed.
2081 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2082 SGI Irix-5.x mips-*-irix5*
2083 SGI Irix-6.x mips-*-irix6*
2084 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2085 VAX running Ultrix vax-*-ultrix*
2087 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2088 and "assf"), have been removed. Use the "sharedlibrary" command, or
2089 its alias "share", instead.
2091 *** Changes in GDB 7.8
2093 * New command line options
2096 This is an alias for the --data-directory option.
2098 * GDB supports printing and modifying of variable length automatic arrays
2099 as specified in ISO C99.
2101 * The ARM simulator now supports instruction level tracing
2102 with or without disassembly.
2106 GDB now has support for scripting using Guile. Whether this is
2107 available is determined at configure time.
2108 Guile version 2.0 or greater is required.
2109 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2111 * New commands (for set/show, see "New options" below)
2115 Invoke CODE by passing it to the Guile interpreter.
2119 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2121 info auto-load guile-scripts [regexp]
2122 Print the list of automatically loaded Guile scripts.
2124 * The source command is now capable of sourcing Guile scripts.
2125 This feature is dependent on the debugger being built with Guile support.
2129 set print symbol-loading (off|brief|full)
2130 show print symbol-loading
2131 Control whether to print informational messages when loading symbol
2132 information for a file. The default is "full", but when debugging
2133 programs with large numbers of shared libraries the amount of output
2134 becomes less useful.
2136 set guile print-stack (none|message|full)
2137 show guile print-stack
2138 Show a stack trace when an error is encountered in a Guile script.
2140 set auto-load guile-scripts (on|off)
2141 show auto-load guile-scripts
2142 Control auto-loading of Guile script files.
2144 maint ada set ignore-descriptive-types (on|off)
2145 maint ada show ignore-descriptive-types
2146 Control whether the debugger should ignore descriptive types in Ada
2147 programs. The default is not to ignore the descriptive types. See
2148 the user manual for more details on descriptive types and the intended
2149 usage of this option.
2151 set auto-connect-native-target
2153 Control whether GDB is allowed to automatically connect to the
2154 native target for the run, attach, etc. commands when not connected
2155 to any target yet. See also "target native" below.
2157 set record btrace replay-memory-access (read-only|read-write)
2158 show record btrace replay-memory-access
2159 Control what memory accesses are allowed during replay.
2161 maint set target-async (on|off)
2162 maint show target-async
2163 This controls whether GDB targets operate in synchronous or
2164 asynchronous mode. Normally the default is asynchronous, if it is
2165 available; but this can be changed to more easily debug problems
2166 occurring only in synchronous mode.
2168 set mi-async (on|off)
2170 Control whether MI asynchronous mode is preferred. This supersedes
2171 "set target-async" of previous GDB versions.
2173 * "set target-async" is deprecated as a CLI option and is now an alias
2174 for "set mi-async" (only puts MI into async mode).
2176 * Background execution commands (e.g., "c&", "s&", etc.) are now
2177 possible ``out of the box'' if the target supports them. Previously
2178 the user would need to explicitly enable the possibility with the
2179 "set target-async on" command.
2181 * New features in the GDB remote stub, GDBserver
2183 ** New option --debug-format=option1[,option2,...] allows one to add
2184 additional text to each output. At present only timestamps
2185 are supported: --debug-format=timestamps.
2186 Timestamps can also be turned on with the
2187 "monitor set debug-format timestamps" command from GDB.
2189 * The 'record instruction-history' command now starts counting instructions
2190 at one. This also affects the instruction ranges reported by the
2191 'record function-call-history' command when given the /i modifier.
2193 * The command 'record function-call-history' supports a new modifier '/c' to
2194 indent the function names based on their call stack depth.
2195 The fields for the '/i' and '/l' modifier have been reordered.
2196 The source line range is now prefixed with 'at'.
2197 The instruction range is now prefixed with 'inst'.
2198 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2199 "record instruction-history" and "list" commands.
2201 * The ranges given as arguments to the 'record function-call-history' and
2202 'record instruction-history' commands are now inclusive.
2204 * The btrace record target now supports the 'record goto' command.
2205 For locations inside the execution trace, the back trace is computed
2206 based on the information stored in the execution trace.
2208 * The btrace record target supports limited reverse execution and replay.
2209 The target does not record data and therefore does not allow reading
2210 memory or registers.
2212 * The "catch syscall" command now works on s390*-linux* targets.
2214 * The "compare-sections" command is no longer specific to target
2215 remote. It now works with all targets.
2217 * All native targets are now consistently called "native".
2218 Consequently, the "target child", "target GNU", "target djgpp",
2219 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2220 commands have been replaced with "target native". The QNX/NTO port
2221 leaves the "procfs" target in place and adds a "native" target for
2222 consistency with other ports. The impact on users should be minimal
2223 as these commands previously either throwed an error, or were
2224 no-ops. The target's name is visible in the output of the following
2225 commands: "help target", "info target", "info files", "maint print
2228 * The "target native" command now connects to the native target. This
2229 can be used to launch native programs even when "set
2230 auto-connect-native-target" is set to off.
2232 * GDB now supports access to Intel MPX registers on GNU/Linux.
2234 * Support for Intel AVX-512 registers on GNU/Linux.
2235 Support displaying and modifying Intel AVX-512 registers
2236 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2238 * New remote packets
2240 qXfer:btrace:read's annex
2241 The qXfer:btrace:read packet supports a new annex 'delta' to read
2242 branch trace incrementally.
2246 ** Valid Python operations on gdb.Value objects representing
2247 structs/classes invoke the corresponding overloaded operators if
2249 ** New `Xmethods' feature in the Python API. Xmethods are
2250 additional methods or replacements for existing methods of a C++
2251 class. This feature is useful for those cases where a method
2252 defined in C++ source code could be inlined or optimized out by
2253 the compiler, making it unavailable to GDB.
2256 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2258 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2259 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2260 its alias "share", instead.
2262 * The commands "set remotebaud" and "show remotebaud" are no longer
2263 supported. Use "set serial baud" and "show serial baud" (respectively)
2268 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2269 target-async". The latter is left as a deprecated alias of the
2270 former for backward compatibility. If the target supports it,
2271 CLI background execution commands are now always possible by
2272 default, independently of whether the frontend stated a
2273 preference for asynchronous execution with "-gdb-set mi-async".
2274 Previously "-gdb-set target-async off" affected both MI execution
2275 commands and CLI execution commands.
2277 *** Changes in GDB 7.7
2279 * Improved support for process record-replay and reverse debugging on
2280 arm*-linux* targets. Support for thumb32 and syscall instruction
2281 recording has been added.
2283 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2285 * GDB now supports Fission DWP file format version 2.
2286 http://gcc.gnu.org/wiki/DebugFission
2288 * New convenience function "$_isvoid", to check whether an expression
2289 is void. A void expression is an expression where the type of the
2290 result is "void". For example, some convenience variables may be
2291 "void" when evaluated (e.g., "$_exitcode" before the execution of
2292 the program being debugged; or an undefined convenience variable).
2293 Another example, when calling a function whose return type is
2296 * The "maintenance print objfiles" command now takes an optional regexp.
2298 * The "catch syscall" command now works on arm*-linux* targets.
2300 * GDB now consistently shows "<not saved>" when printing values of
2301 registers the debug info indicates have not been saved in the frame
2302 and there's nowhere to retrieve them from
2303 (callee-saved/call-clobbered registers):
2308 (gdb) info registers rax
2311 Before, the former would print "<optimized out>", and the latter
2312 "*value not available*".
2314 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2319 ** Frame filters and frame decorators have been added.
2320 ** Temporary breakpoints are now supported.
2321 ** Line tables representation has been added.
2322 ** New attribute 'parent_type' for gdb.Field objects.
2323 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2324 ** New attribute 'name' for gdb.Type objects.
2328 Nios II ELF nios2*-*-elf
2329 Nios II GNU/Linux nios2*-*-linux
2330 Texas Instruments MSP430 msp430*-*-elf
2332 * Removed native configurations
2334 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2335 been removed. ELF variants of these configurations are kept supported.
2337 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2338 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2339 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2340 i[34567]86-*-openbsd3.[0-3]
2341 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2342 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2343 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2347 Like "catch throw", but catches a re-thrown exception.
2348 maint check-psymtabs
2349 Renamed from old "maint check-symtabs".
2351 Perform consistency checks on symtabs.
2352 maint expand-symtabs
2353 Expand symtabs matching an optional regexp.
2356 Display the details of GDB configure-time options.
2358 maint set|show per-command
2359 maint set|show per-command space
2360 maint set|show per-command time
2361 maint set|show per-command symtab
2362 Enable display of per-command gdb resource usage.
2364 remove-symbol-file FILENAME
2365 remove-symbol-file -a ADDRESS
2366 Remove a symbol file added via add-symbol-file. The file to remove
2367 can be identified by its filename or by an address that lies within
2368 the boundaries of this symbol file in memory.
2371 info exceptions REGEXP
2372 Display the list of Ada exceptions defined in the program being
2373 debugged. If provided, only the exceptions whose names match REGEXP
2378 set debug symfile off|on
2380 Control display of debugging info regarding reading symbol files and
2381 symbol tables within those files
2383 set print raw frame-arguments
2384 show print raw frame-arguments
2385 Set/show whether to print frame arguments in raw mode,
2386 disregarding any defined pretty-printers.
2388 set remote trace-status-packet
2389 show remote trace-status-packet
2390 Set/show the use of remote protocol qTStatus packet.
2394 Control display of debugging messages related to Nios II targets.
2398 Control whether target-assisted range stepping is enabled.
2400 set startup-with-shell
2401 show startup-with-shell
2402 Specifies whether Unix child processes are started via a shell or
2407 Use the target memory cache for accesses to the code segment. This
2408 improves performance of remote debugging (particularly disassembly).
2410 * You can now use a literal value 'unlimited' for options that
2411 interpret 0 or -1 as meaning "unlimited". E.g., "set
2412 trace-buffer-size unlimited" is now an alias for "set
2413 trace-buffer-size -1" and "set height unlimited" is now an alias for
2416 * The "set debug symtab-create" debugging option of GDB has been changed to
2417 accept a verbosity level. 0 means "off", 1 provides basic debugging
2418 output, and values of 2 or greater provides more verbose output.
2420 * New command-line options
2422 Display the details of GDB configure-time options.
2424 * The command 'tsave' can now support new option '-ctf' to save trace
2425 buffer in Common Trace Format.
2427 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2430 * GDB now implements the C++ 'typeid' operator.
2432 * The new convenience variable $_exception holds the exception being
2433 thrown or caught at an exception-related catchpoint.
2435 * The exception-related catchpoints, like "catch throw", now accept a
2436 regular expression which can be used to filter exceptions by type.
2438 * The new convenience variable $_exitsignal is automatically set to
2439 the terminating signal number when the program being debugged dies
2440 due to an uncaught signal.
2444 ** All MI commands now accept an optional "--language" option.
2445 Support for this feature can be verified by using the "-list-features"
2446 command, which should contain "language-option".
2448 ** The new command -info-gdb-mi-command allows the user to determine
2449 whether a GDB/MI command is supported or not.
2451 ** The "^error" result record returned when trying to execute an undefined
2452 GDB/MI command now provides a variable named "code" whose content is the
2453 "undefined-command" error code. Support for this feature can be verified
2454 by using the "-list-features" command, which should contain
2455 "undefined-command-error-code".
2457 ** The -trace-save MI command can optionally save trace buffer in Common
2460 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2462 ** The command -data-list-register-values now accepts an optional
2463 "--skip-unavailable" option. When used, only the available registers
2466 ** The new command -trace-frame-collected dumps collected variables,
2467 computed expressions, tvars, memory and registers in a traceframe.
2469 ** The commands -stack-list-locals, -stack-list-arguments and
2470 -stack-list-variables now accept an option "--skip-unavailable".
2471 When used, only the available locals or arguments are displayed.
2473 ** The -exec-run command now accepts an optional "--start" option.
2474 When used, the command follows the same semantics as the "start"
2475 command, stopping the program's execution at the start of its
2476 main subprogram. Support for this feature can be verified using
2477 the "-list-features" command, which should contain
2478 "exec-run-start-option".
2480 ** The new commands -catch-assert and -catch-exceptions insert
2481 catchpoints stopping the program when Ada exceptions are raised.
2483 ** The new command -info-ada-exceptions provides the equivalent of
2484 the new "info exceptions" command.
2486 * New system-wide configuration scripts
2487 A GDB installation now provides scripts suitable for use as system-wide
2488 configuration scripts for the following systems:
2492 * GDB now supports target-assigned range stepping with remote targets.
2493 This improves the performance of stepping source lines by reducing
2494 the number of control packets from/to GDB. See "New remote packets"
2497 * GDB now understands the element 'tvar' in the XML traceframe info.
2498 It has the id of the collected trace state variables.
2500 * On S/390 targets that provide the transactional-execution feature,
2501 the program interruption transaction diagnostic block (TDB) is now
2502 represented as a number of additional "registers" in GDB.
2504 * New remote packets
2508 The vCont packet supports a new 'r' action, that tells the remote
2509 stub to step through an address range itself, without GDB
2510 involvemement at each single-step.
2512 qXfer:libraries-svr4:read's annex
2513 The previously unused annex of the qXfer:libraries-svr4:read packet
2514 is now used to support passing an argument list. The remote stub
2515 reports support for this argument list to GDB's qSupported query.
2516 The defined arguments are "start" and "prev", used to reduce work
2517 necessary for library list updating, resulting in significant
2520 * New features in the GDB remote stub, GDBserver
2522 ** GDBserver now supports target-assisted range stepping. Currently
2523 enabled on x86/x86_64 GNU/Linux targets.
2525 ** GDBserver now adds element 'tvar' in the XML in the reply to
2526 'qXfer:traceframe-info:read'. It has the id of the collected
2527 trace state variables.
2529 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2532 * New 'z' formatter for printing and examining memory, this displays the
2533 value as hexadecimal zero padded on the left to the size of the type.
2535 * GDB can now use Windows x64 unwinding data.
2537 * The "set remotebaud" command has been replaced by "set serial baud".
2538 Similarly, "show remotebaud" has been replaced by "show serial baud".
2539 The "set remotebaud" and "show remotebaud" commands are still available
2540 to provide backward compatibility with older versions of GDB.
2542 *** Changes in GDB 7.6
2544 * Target record has been renamed to record-full.
2545 Record/replay is now enabled with the "record full" command.
2546 This also affects settings that are associated with full record/replay
2547 that have been moved from "set/show record" to "set/show record full":
2549 set|show record full insn-number-max
2550 set|show record full stop-at-limit
2551 set|show record full memory-query
2553 * A new record target "record-btrace" has been added. The new target
2554 uses hardware support to record the control-flow of a process. It
2555 does not support replaying the execution, but it implements the
2556 below new commands for investigating the recorded execution log.
2557 This new recording method can be enabled using:
2561 The "record-btrace" target is only available on Intel Atom processors
2562 and requires a Linux kernel 2.6.32 or later.
2564 * Two new commands have been added for record/replay to give information
2565 about the recorded execution without having to replay the execution.
2566 The commands are only supported by "record btrace".
2568 record instruction-history prints the execution history at
2569 instruction granularity
2571 record function-call-history prints the execution history at
2572 function granularity
2574 * New native configurations
2576 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2577 FreeBSD/powerpc powerpc*-*-freebsd
2578 x86_64/Cygwin x86_64-*-cygwin*
2579 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2583 ARM AArch64 aarch64*-*-elf
2584 ARM AArch64 GNU/Linux aarch64*-*-linux
2585 Lynx 178 PowerPC powerpc-*-lynx*178
2586 x86_64/Cygwin x86_64-*-cygwin*
2587 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2589 * If the configured location of system.gdbinit file (as given by the
2590 --with-system-gdbinit option at configure time) is in the
2591 data-directory (as specified by --with-gdb-datadir at configure
2592 time) or in one of its subdirectories, then GDB will look for the
2593 system-wide init file in the directory specified by the
2594 --data-directory command-line option.
2596 * New command line options:
2598 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2599 other initialization files, unlike -nx which disables all of them.
2601 * Removed command line options
2603 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2606 * The 'ptype' and 'whatis' commands now accept an argument to control
2609 * 'info proc' now works on some core files.
2613 ** Vectors can be created with gdb.Type.vector.
2615 ** Python's atexit.register now works in GDB.
2617 ** Types can be pretty-printed via a Python API.
2619 ** Python 3 is now supported (in addition to Python 2.4 or later)
2621 ** New class gdb.Architecture exposes GDB's internal representation
2622 of architecture in the Python API.
2624 ** New method Frame.architecture returns the gdb.Architecture object
2625 corresponding to the frame's architecture.
2627 * New Python-based convenience functions:
2629 ** $_memeq(buf1, buf2, length)
2630 ** $_streq(str1, str2)
2632 ** $_regex(str, regex)
2634 * The 'cd' command now defaults to using '~' (the home directory) if not
2637 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2638 default for GCC since November 2000.
2640 * The command 'forward-search' can now be abbreviated as 'fo'.
2642 * The command 'info tracepoints' can now display 'installed on target'
2643 or 'not installed on target' for each non-pending location of tracepoint.
2645 * New configure options
2647 --enable-libmcheck/--disable-libmcheck
2648 By default, development versions are built with -lmcheck on hosts
2649 that support it, in order to help track memory corruption issues.
2650 Release versions, on the other hand, are built without -lmcheck
2651 by default. The --enable-libmcheck/--disable-libmcheck configure
2652 options allow the user to override that default.
2653 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2654 This configure option allows the user to build GDB with
2655 libbabeltrace using which GDB can read Common Trace Format data.
2657 * New commands (for set/show, see "New options" below)
2660 Catch signals. This is similar to "handle", but allows commands and
2661 conditions to be attached.
2664 List the BFDs known to GDB.
2666 python-interactive [command]
2668 Start a Python interactive prompt, or evaluate the optional command
2669 and print the result of expressions.
2672 "py" is a new alias for "python".
2674 enable type-printer [name]...
2675 disable type-printer [name]...
2676 Enable or disable type printers.
2680 ** For the Renesas Super-H architecture, the "regs" command has been removed
2681 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2686 set print type methods (on|off)
2687 show print type methods
2688 Control whether method declarations are displayed by "ptype".
2689 The default is to show them.
2691 set print type typedefs (on|off)
2692 show print type typedefs
2693 Control whether typedef definitions are displayed by "ptype".
2694 The default is to show them.
2696 set filename-display basename|relative|absolute
2697 show filename-display
2698 Control the way in which filenames is displayed.
2699 The default is "relative", which preserves previous behavior.
2701 set trace-buffer-size
2702 show trace-buffer-size
2703 Request target to change the size of trace buffer.
2705 set remote trace-buffer-size-packet auto|on|off
2706 show remote trace-buffer-size-packet
2707 Control the use of the remote protocol `QTBuffer:size' packet.
2711 Control display of debugging messages related to ARM AArch64.
2714 set debug coff-pe-read
2715 show debug coff-pe-read
2716 Control display of debugging messages related to reading of COFF/PE
2721 Control display of debugging messages related to Mach-O symbols
2724 set debug notification
2725 show debug notification
2726 Control display of debugging info for async remote notification.
2730 ** Command parameter changes are now notified using new async record
2731 "=cmd-param-changed".
2732 ** Trace frame changes caused by command "tfind" are now notified using
2733 new async record "=traceframe-changed".
2734 ** The creation, deletion and modification of trace state variables
2735 are now notified using new async records "=tsv-created",
2736 "=tsv-deleted" and "=tsv-modified".
2737 ** The start and stop of process record are now notified using new
2738 async record "=record-started" and "=record-stopped".
2739 ** Memory changes are now notified using new async record
2741 ** The data-disassemble command response will include a "fullname" field
2742 containing the absolute file name when source has been requested.
2743 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2744 command, to allow pattern filling of memory areas.
2745 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2746 library load/unload events.
2747 ** The response to breakpoint commands and breakpoint async records
2748 includes an "installed" field containing a boolean state about each
2749 non-pending tracepoint location is whether installed on target or not.
2750 ** Output of the "-trace-status" command includes a "trace-file" field
2751 containing the name of the trace file being examined. This field is
2752 optional, and only present when examining a trace file.
2753 ** The "fullname" field is now always present along with the "file" field,
2754 even if the file cannot be found by GDB.
2756 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2757 You must have the LZMA library available when configuring GDB for this
2758 feature to be enabled. For more information, see:
2759 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2761 * New remote packets
2764 Set the size of trace buffer. The remote stub reports support for this
2765 packet to gdb's qSupported query.
2768 Enable Branch Trace Store (BTS)-based branch tracing for the current
2769 thread. The remote stub reports support for this packet to gdb's
2773 Disable branch tracing for the current thread. The remote stub reports
2774 support for this packet to gdb's qSupported query.
2777 Read the traced branches for the current thread. The remote stub
2778 reports support for this packet to gdb's qSupported query.
2780 *** Changes in GDB 7.5
2782 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2783 for more x32 ABI info.
2785 * GDB now supports access to MIPS DSP registers on Linux targets.
2787 * GDB now supports debugging microMIPS binaries.
2789 * The "info os" command on GNU/Linux can now display information on
2790 several new classes of objects managed by the operating system:
2791 "info os procgroups" lists process groups
2792 "info os files" lists file descriptors
2793 "info os sockets" lists internet-domain sockets
2794 "info os shm" lists shared-memory regions
2795 "info os semaphores" lists semaphores
2796 "info os msg" lists message queues
2797 "info os modules" lists loaded kernel modules
2799 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2800 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2801 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2802 options and inspect the probe arguments using the new $_probe_arg family
2803 of convenience variables. You can obtain more information about SystemTap
2804 in <http://sourceware.org/systemtap/>.
2806 * GDB now supports reversible debugging on ARM, it allows you to
2807 debug basic ARM and THUMB instructions, and provides
2808 record/replay support.
2810 * The option "symbol-reloading" has been deleted as it is no longer used.
2814 ** GDB commands implemented in Python can now be put in command class
2817 ** The "maint set python print-stack on|off" is now deleted.
2819 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2820 apply "flag enum"-style pretty-printing to any enum.
2822 ** gdb.lookup_symbol can now work when there is no current frame.
2824 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2825 the source at which the symbol was defined.
2827 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2828 method 'value'. The former indicates whether the symbol needs a
2829 frame in order to compute its value, and the latter computes the
2832 ** A new method 'referenced_value' on gdb.Value objects which can
2833 dereference pointer as well as C++ reference values.
2835 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2836 which return the global and static blocks (as gdb.Block objects),
2837 of the underlying symbol table, respectively.
2839 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2840 object associated with a PC value.
2842 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2843 of the address range occupied by code for the current source line.
2845 * Go language support.
2846 GDB now supports debugging programs written in the Go programming
2849 * GDBserver now supports stdio connections.
2850 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2852 * The binary "gdbtui" can no longer be built or installed.
2853 Use "gdb -tui" instead.
2855 * GDB will now print "flag" enums specially. A flag enum is one where
2856 all the enumerator values have no bits in common when pairwise
2857 "and"ed. When printing a value whose type is a flag enum, GDB will
2858 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2859 (gdb) print (enum E) 3
2862 * The filename part of a linespec will now match trailing components
2863 of a source file name. For example, "break gcc/expr.c:1000" will
2864 now set a breakpoint in build/gcc/expr.c, but not
2865 build/libcpp/expr.c.
2867 * The "info proc" and "generate-core-file" commands will now also
2868 work on remote targets connected to GDBserver on Linux.
2870 * The command "info catch" has been removed. It has been disabled
2871 since December 2007.
2873 * The "catch exception" and "catch assert" commands now accept
2874 a condition at the end of the command, much like the "break"
2875 command does. For instance:
2877 (gdb) catch exception Constraint_Error if Barrier = True
2879 Previously, it was possible to add a condition to such catchpoints,
2880 but it had to be done as a second step, after the catchpoint had been
2881 created, using the "condition" command.
2883 * The "info static-tracepoint-marker" command will now also work on
2884 native Linux targets with in-process agent.
2886 * GDB can now set breakpoints on inlined functions.
2888 * The .gdb_index section has been updated to include symbols for
2889 inlined functions. GDB will ignore older .gdb_index sections by
2890 default, which could cause symbol files to be loaded more slowly
2891 until their .gdb_index sections can be recreated. The new command
2892 "set use-deprecated-index-sections on" will cause GDB to use any older
2893 .gdb_index sections it finds. This will restore performance, but the
2894 ability to set breakpoints on inlined functions will be lost in symbol
2895 files with older .gdb_index sections.
2897 The .gdb_index section has also been updated to record more information
2898 about each symbol. This speeds up the "info variables", "info functions"
2899 and "info types" commands when used with programs having the .gdb_index
2900 section, as well as speeding up debugging with shared libraries using
2901 the .gdb_index section.
2903 * Ada support for GDB/MI Variable Objects has been added.
2905 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2910 ** New command -info-os is the MI equivalent of "info os".
2912 ** Output logs ("set logging" and related) now include MI output.
2916 ** "set use-deprecated-index-sections on|off"
2917 "show use-deprecated-index-sections on|off"
2918 Controls the use of deprecated .gdb_index sections.
2920 ** "catch load" and "catch unload" can be used to stop when a shared
2921 library is loaded or unloaded, respectively.
2923 ** "enable count" can be used to auto-disable a breakpoint after
2926 ** "info vtbl" can be used to show the virtual method tables for
2927 C++ and Java objects.
2929 ** "explore" and its sub commands "explore value" and "explore type"
2930 can be used to recursively explore values and types of
2931 expressions. These commands are available only if GDB is
2932 configured with '--with-python'.
2934 ** "info auto-load" shows status of all kinds of auto-loaded files,
2935 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2936 sequences of commands files, "info auto-load python-scripts"
2937 shows status of auto-loading Python script files,
2938 "info auto-load local-gdbinit" shows status of loading init file
2939 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2940 status of inferior specific thread debugging shared library loading.
2942 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2943 and "show auto-load-scripts" commands have been deprecated, use their
2944 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2945 and "show auto-load python-scripts" counterparts instead.
2947 ** "dprintf location,format,args..." creates a dynamic printf, which
2948 is basically a breakpoint that does a printf and immediately
2949 resumes your program's execution, so it is like a printf that you
2950 can insert dynamically at runtime instead of at compiletime.
2952 ** "set print symbol"
2954 Controls whether GDB attempts to display the symbol, if any,
2955 corresponding to addresses it prints. This defaults to "on", but
2956 you can set it to "off" to restore GDB's previous behavior.
2958 * Deprecated commands
2960 ** For the Renesas Super-H architecture, the "regs" command has been
2961 deprecated, and "info all-registers" should be used instead.
2965 Renesas RL78 rl78-*-elf
2966 HP OpenVMS ia64 ia64-hp-openvms*
2968 * GDBserver supports evaluation of breakpoint conditions. When
2969 support is advertised by GDBserver, GDB may be told to send the
2970 breakpoint conditions in bytecode form to GDBserver. GDBserver
2971 will only report the breakpoint trigger to GDB when its condition
2976 set mips compression
2977 show mips compression
2978 Select the compressed ISA encoding used in functions that have no symbol
2979 information available. The encoding can be set to either of:
2982 and is updated automatically from ELF file flags if available.
2984 set breakpoint condition-evaluation
2985 show breakpoint condition-evaluation
2986 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2987 GDBserver ("target"). Default option "auto" chooses the most efficient
2989 This option can improve debugger efficiency depending on the speed of the
2993 Disable auto-loading globally.
2996 Show auto-loading setting of all kinds of auto-loaded files.
2998 set auto-load gdb-scripts on|off
2999 show auto-load gdb-scripts
3000 Control auto-loading of GDB canned sequences of commands files.
3002 set auto-load python-scripts on|off
3003 show auto-load python-scripts
3004 Control auto-loading of Python script files.
3006 set auto-load local-gdbinit on|off
3007 show auto-load local-gdbinit
3008 Control loading of init file (.gdbinit) from current directory.
3010 set auto-load libthread-db on|off
3011 show auto-load libthread-db
3012 Control auto-loading of inferior specific thread debugging shared library.
3014 set auto-load scripts-directory <dir1>[:<dir2>...]
3015 show auto-load scripts-directory
3016 Set a list of directories from which to load auto-loaded scripts.
3017 Automatically loaded Python scripts and GDB scripts are located in one
3018 of the directories listed by this option.
3019 The delimiter (':' above) may differ according to the host platform.
3021 set auto-load safe-path <dir1>[:<dir2>...]
3022 show auto-load safe-path
3023 Set a list of directories from which it is safe to auto-load files.
3024 The delimiter (':' above) may differ according to the host platform.
3026 set debug auto-load on|off
3027 show debug auto-load
3028 Control display of debugging info for auto-loading the files above.
3030 set dprintf-style gdb|call|agent
3032 Control the way in which a dynamic printf is performed; "gdb"
3033 requests a GDB printf command, while "call" causes dprintf to call a
3034 function in the inferior. "agent" requests that the target agent
3035 (such as GDBserver) do the printing.
3037 set dprintf-function <expr>
3038 show dprintf-function
3039 set dprintf-channel <expr>
3040 show dprintf-channel
3041 Set the function and optional first argument to the call when using
3042 the "call" style of dynamic printf.
3044 set disconnected-dprintf on|off
3045 show disconnected-dprintf
3046 Control whether agent-style dynamic printfs continue to be in effect
3047 after GDB disconnects.
3049 * New configure options
3051 --with-auto-load-dir
3052 Configure default value for the 'set auto-load scripts-directory'
3053 setting above. It defaults to '$debugdir:$datadir/auto-load',
3054 $debugdir representing global debugging info directories (available
3055 via 'show debug-file-directory') and $datadir representing GDB's data
3056 directory (available via 'show data-directory').
3058 --with-auto-load-safe-path
3059 Configure default value for the 'set auto-load safe-path' setting
3060 above. It defaults to the --with-auto-load-dir setting.
3062 --without-auto-load-safe-path
3063 Set 'set auto-load safe-path' to '/', effectively disabling this
3066 * New remote packets
3068 z0/z1 conditional breakpoints extension
3070 The z0/z1 breakpoint insertion packets have been extended to carry
3071 a list of conditional expressions over to the remote stub depending on the
3072 condition evaluation mode. The use of this extension can be controlled
3073 via the "set remote conditional-breakpoints-packet" command.
3077 Specify the signals which the remote stub may pass to the debugged
3078 program without GDB involvement.
3080 * New command line options
3082 --init-command=FILE, -ix Like --command, -x but execute it
3083 before loading inferior.
3084 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3085 execute it before loading inferior.
3087 *** Changes in GDB 7.4
3089 * GDB now handles ambiguous linespecs more consistently; the existing
3090 FILE:LINE support has been expanded to other types of linespecs. A
3091 breakpoint will now be set on all matching locations in all
3092 inferiors, and locations will be added or removed according to
3095 * GDB now allows you to skip uninteresting functions and files when
3096 stepping with the "skip function" and "skip file" commands.
3098 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3099 and "show remote hardware-watchpoint-length-limit". These allows to
3100 set or show the maximum length limit (in bytes) of a remote
3101 target hardware watchpoint.
3103 This allows e.g. to use "unlimited" hardware watchpoints with the
3104 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3105 watchpoints are slower than real hardware watchpoints but are
3106 significantly faster than gdb software watchpoints.
3110 ** The register_pretty_printer function in module gdb.printing now takes
3111 an optional `replace' argument. If True, the new printer replaces any
3114 ** The "maint set python print-stack on|off" command has been
3115 deprecated and will be deleted in GDB 7.5.
3116 A new command: "set python print-stack none|full|message" has
3117 replaced it. Additionally, the default for "print-stack" is
3118 now "message", which just prints the error message without
3121 ** A prompt substitution hook (prompt_hook) is now available to the
3124 ** A new Python module, gdb.prompt has been added to the GDB Python
3125 modules library. This module provides functionality for
3126 escape sequences in prompts (used by set/show
3127 extended-prompt). These escape sequences are replaced by their
3128 corresponding value.
3130 ** Python commands and convenience-functions located in
3131 'data-directory'/python/gdb/command and
3132 'data-directory'/python/gdb/function are now automatically loaded
3135 ** Blocks now provide four new attributes. global_block and
3136 static_block will return the global and static blocks
3137 respectively. is_static and is_global are boolean attributes
3138 that indicate if the block is one of those two types.
3140 ** Symbols now provide the "type" attribute, the type of the symbol.
3142 ** The "gdb.breakpoint" function has been deprecated in favor of
3145 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3146 of a function. This class is based on the "finish" command
3147 available in the CLI.
3149 ** Type objects for struct and union types now allow access to
3150 the fields using standard Python dictionary (mapping) methods.
3151 For example, "some_type['myfield']" now works, as does
3152 "some_type.items()".
3154 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3157 ** A new function, "deep_items" has been added to the gdb.types
3158 module in the GDB Python modules library. This function returns
3159 an iterator over the fields of a struct or union type. Unlike
3160 the standard Python "iteritems" method, it will recursively traverse
3161 any anonymous fields.
3165 ** "*stopped" events can report several new "reason"s, such as
3168 ** Breakpoint changes are now notified using new async records, like
3169 "=breakpoint-modified".
3171 ** New command -ada-task-info.
3173 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3174 $sdir specifies the default system locations of shared libraries.
3175 $pdir specifies the directory where the libpthread used by the application
3178 GDB no longer looks in $sdir and $pdir after it has searched the directories
3179 mentioned in libthread-db-search-path. If you want to search those
3180 directories, they must be specified in libthread-db-search-path.
3181 The default value of libthread-db-search-path on GNU/Linux and Solaris
3182 systems is now "$sdir:$pdir".
3184 $pdir is not supported by gdbserver, it is currently ignored.
3185 $sdir is supported by gdbserver.
3187 * New configure option --with-iconv-bin.
3188 When using the internationalization support like the one in the GNU C
3189 library, GDB will invoke the "iconv" program to get a list of supported
3190 character sets. If this program lives in a non-standard location, one can
3191 use this option to specify where to find it.
3193 * When natively debugging programs on PowerPC BookE processors running
3194 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3195 watchpoints, which specify a mask in addition to an address to watch.
3196 The mask specifies that some bits of an address (the bits which are
3197 reset in the mask) should be ignored when matching the address accessed
3198 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3199 section in the user manual for more details.
3201 * The new option --once causes GDBserver to stop listening for connections once
3202 the first connection is made. The listening port used by GDBserver will
3203 become available after that.
3205 * New commands "info macros" and "alias" have been added.
3207 * New function parameters suffix @entry specifies value of function parameter
3208 at the time the function got called. Entry values are available only since
3214 "!" is now an alias of the "shell" command.
3215 Note that no space is needed between "!" and SHELL COMMAND.
3219 watch EXPRESSION mask MASK_VALUE
3220 The watch command now supports the mask argument which allows creation
3221 of masked watchpoints, if the current architecture supports this feature.
3223 info auto-load-scripts [REGEXP]
3224 This command was formerly named "maintenance print section-scripts".
3225 It is now generally useful and is no longer a maintenance-only command.
3227 info macro [-all] [--] MACRO
3228 The info macro command has new options `-all' and `--'. The first for
3229 printing all definitions of a macro. The second for explicitly specifying
3230 the end of arguments and the beginning of the macro name in case the macro
3231 name starts with a hyphen.
3233 collect[/s] EXPRESSIONS
3234 The tracepoint collect command now takes an optional modifier "/s"
3235 that directs it to dereference pointer-to-character types and
3236 collect the bytes of memory up to a zero byte. The behavior is
3237 similar to what you see when you use the regular print command on a
3238 string. An optional integer following the "/s" sets a bound on the
3239 number of bytes that will be collected.
3242 The trace start command now interprets any supplied arguments as a
3243 note to be recorded with the trace run, with an effect similar to
3244 setting the variable trace-notes.
3247 The trace stop command now interprets any arguments as a note to be
3248 mentioned along with the tstatus report that the trace was stopped
3249 with a command. The effect is similar to setting the variable
3252 * Tracepoints can now be enabled and disabled at any time after a trace
3253 experiment has been started using the standard "enable" and "disable"
3254 commands. It is now possible to start a trace experiment with no enabled
3255 tracepoints; GDB will display a warning, but will allow the experiment to
3256 begin, assuming that tracepoints will be enabled as needed while the trace
3259 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3260 locations with 4-byte instructions, when they were previously
3261 limited to locations with instructions of 5 bytes or longer.
3265 set debug dwarf2-read
3266 show debug dwarf2-read
3267 Turns on or off display of debugging messages related to reading
3268 DWARF debug info. The default is off.
3270 set debug symtab-create
3271 show debug symtab-create
3272 Turns on or off display of debugging messages related to symbol table
3273 creation. The default is off.
3276 show extended-prompt
3277 Set the GDB prompt, and allow escape sequences to be inserted to
3278 display miscellaneous information (see 'help set extended-prompt'
3279 for the list of sequences). This prompt (and any information
3280 accessed through the escape sequences) is updated every time the
3281 prompt is displayed.
3283 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3284 show print entry-values
3285 Set printing of frame argument values at function entry. In some cases
3286 GDB can determine the value of function argument which was passed by the
3287 function caller, even if the value was modified inside the called function.
3289 set debug entry-values
3290 show debug entry-values
3291 Control display of debugging info for determining frame argument values at
3292 function entry and virtual tail call frames.
3294 set basenames-may-differ
3295 show basenames-may-differ
3296 Set whether a source file may have multiple base names.
3297 (A "base name" is the name of a file with the directory part removed.
3298 Example: The base name of "/home/user/hello.c" is "hello.c".)
3299 If set, GDB will canonicalize file names (e.g., expand symlinks)
3300 before comparing them. Canonicalization is an expensive operation,
3301 but it allows the same file be known by more than one base name.
3302 If not set (the default), all source files are assumed to have just
3303 one base name, and gdb will do file name comparisons more efficiently.
3309 Set a user name and notes for the current and any future trace runs.
3310 This is useful for long-running and/or disconnected traces, to
3311 inform others (or yourself) as to who is running the trace, supply
3312 contact information, or otherwise explain what is going on.
3314 set trace-stop-notes
3315 show trace-stop-notes
3316 Set a note attached to the trace run, that is displayed when the
3317 trace has been stopped by a tstop command. This is useful for
3318 instance as an explanation, if you are stopping a trace run that was
3319 started by someone else.
3321 * New remote packets
3325 Dynamically enable a tracepoint in a started trace experiment.
3329 Dynamically disable a tracepoint in a started trace experiment.
3333 Set the user and notes of the trace run.
3337 Query the current status of a tracepoint.
3341 Query the minimum length of instruction at which a fast tracepoint may
3344 * Dcache size (number of lines) and line-size are now runtime-configurable
3345 via "set dcache line" and "set dcache line-size" commands.
3349 Texas Instruments TMS320C6x tic6x-*-*
3353 Renesas RL78 rl78-*-elf
3355 *** Changes in GDB 7.3.1
3357 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3359 *** Changes in GDB 7.3
3361 * GDB has a new command: "thread find [REGEXP]".
3362 It finds the thread id whose name, target id, or thread extra info
3363 matches the given regular expression.
3365 * The "catch syscall" command now works on mips*-linux* targets.
3367 * The -data-disassemble MI command now supports modes 2 and 3 for
3368 dumping the instruction opcodes.
3370 * New command line options
3372 -data-directory DIR Specify DIR as the "data-directory".
3373 This is mostly for testing purposes.
3375 * The "maint set python auto-load on|off" command has been renamed to
3376 "set auto-load-scripts on|off".
3378 * GDB has a new command: "set directories".
3379 It is like the "dir" command except that it replaces the
3380 source path list instead of augmenting it.
3382 * GDB now understands thread names.
3384 On GNU/Linux, "info threads" will display the thread name as set by
3385 prctl or pthread_setname_np.
3387 There is also a new command, "thread name", which can be used to
3388 assign a name internally for GDB to display.
3391 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3392 has been integrated into GDB.
3396 ** The function gdb.Write now accepts an optional keyword 'stream'.
3397 This keyword, when provided, will direct the output to either
3398 stdout, stderr, or GDB's logging output.
3400 ** Parameters can now be be sub-classed in Python, and in particular
3401 you may implement the get_set_doc and get_show_doc functions.
3402 This improves how Parameter set/show documentation is processed
3403 and allows for more dynamic content.
3405 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3406 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3407 have an is_valid method.
3409 ** Breakpoints can now be sub-classed in Python, and in particular
3410 you may implement a 'stop' function that is executed each time
3411 the inferior reaches that breakpoint.
3413 ** New function gdb.lookup_global_symbol looks up a global symbol.
3415 ** GDB values in Python are now callable if the value represents a
3416 function. For example, if 'some_value' represents a function that
3417 takes two integer parameters and returns a value, you can call
3418 that function like so:
3420 result = some_value (10,20)
3422 ** Module gdb.types has been added.
3423 It contains a collection of utilities for working with gdb.Types objects:
3424 get_basic_type, has_field, make_enum_dict.
3426 ** Module gdb.printing has been added.
3427 It contains utilities for writing and registering pretty-printers.
3428 New classes: PrettyPrinter, SubPrettyPrinter,
3429 RegexpCollectionPrettyPrinter.
3430 New function: register_pretty_printer.
3432 ** New commands "info pretty-printers", "enable pretty-printer" and
3433 "disable pretty-printer" have been added.
3435 ** gdb.parameter("directories") is now available.
3437 ** New function gdb.newest_frame returns the newest frame in the
3440 ** The gdb.InferiorThread class has a new "name" attribute. This
3441 holds the thread's name.
3443 ** Python Support for Inferior events.
3444 Python scripts can add observers to be notified of events
3445 occurring in the process being debugged.
3446 The following events are currently supported:
3447 - gdb.events.cont Continue event.
3448 - gdb.events.exited Inferior exited event.
3449 - gdb.events.stop Signal received, and Breakpoint hit events.
3453 ** GDB now puts template parameters in scope when debugging in an
3454 instantiation. For example, if you have:
3456 template<int X> int func (void) { return X; }
3458 then if you step into func<5>, "print X" will show "5". This
3459 feature requires proper debuginfo support from the compiler; it
3460 was added to GCC 4.5.
3462 ** The motion commands "next", "finish", "until", and "advance" now
3463 work better when exceptions are thrown. In particular, GDB will
3464 no longer lose control of the inferior; instead, the GDB will
3465 stop the inferior at the point at which the exception is caught.
3466 This functionality requires a change in the exception handling
3467 code that was introduced in GCC 4.5.
3469 * GDB now follows GCC's rules on accessing volatile objects when
3470 reading or writing target state during expression evaluation.
3471 One notable difference to prior behavior is that "print x = 0"
3472 no longer generates a read of x; the value of the assignment is
3473 now always taken directly from the value being assigned.
3475 * GDB now has some support for using labels in the program's source in
3476 linespecs. For instance, you can use "advance label" to continue
3477 execution to a label.
3479 * GDB now has support for reading and writing a new .gdb_index
3480 section. This section holds a fast index of DWARF debugging
3481 information and can be used to greatly speed up GDB startup and
3482 operation. See the documentation for `save gdb-index' for details.
3484 * The "watch" command now accepts an optional "-location" argument.
3485 When used, this causes GDB to watch the memory referred to by the
3486 expression. Such a watchpoint is never deleted due to it going out
3489 * GDB now supports thread debugging of core dumps on GNU/Linux.
3491 GDB now activates thread debugging using the libthread_db library
3492 when debugging GNU/Linux core dumps, similarly to when debugging
3493 live processes. As a result, when debugging a core dump file, GDB
3494 is now able to display pthread_t ids of threads. For example, "info
3495 threads" shows the same output as when debugging the process when it
3496 was live. In earlier releases, you'd see something like this:
3499 * 1 LWP 6780 main () at main.c:10
3501 While now you see this:
3504 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3506 It is also now possible to inspect TLS variables when debugging core
3509 When debugging a core dump generated on a machine other than the one
3510 used to run GDB, you may need to point GDB at the correct
3511 libthread_db library with the "set libthread-db-search-path"
3512 command. See the user manual for more details on this command.
3514 * When natively debugging programs on PowerPC BookE processors running
3515 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3516 which stop execution of the inferior whenever it executes an instruction
3517 at any address within the specified range. See the "PowerPC Embedded"
3518 section in the user manual for more details.
3520 * New features in the GDB remote stub, GDBserver
3522 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3523 and i686 LynxOS (version 5.x).
3525 ** GDBserver is now supported on Blackfin Linux.
3527 * New native configurations
3529 ia64 HP-UX ia64-*-hpux*
3533 Analog Devices, Inc. Blackfin Processor bfin-*
3535 * Ada task switching is now supported on sparc-elf targets when
3536 debugging a program using the Ravenscar Profile. For more information,
3537 see the "Tasking Support when using the Ravenscar Profile" section
3538 in the GDB user manual.
3540 * Guile support was removed.
3542 * New features in the GNU simulator
3544 ** The --map-info flag lists all known core mappings.
3546 ** CFI flashes may be simulated via the "cfi" device.
3548 *** Changes in GDB 7.2
3550 * Shared library support for remote targets by default
3552 When GDB is configured for a generic, non-OS specific target, like
3553 for example, --target=arm-eabi or one of the many *-*-elf targets,
3554 GDB now queries remote stubs for loaded shared libraries using the
3555 `qXfer:libraries:read' packet. Previously, shared library support
3556 was always disabled for such configurations.
3560 ** Argument Dependent Lookup (ADL)
3562 In C++ ADL lookup directs function search to the namespaces of its
3563 arguments even if the namespace has not been imported.
3573 Here the compiler will search for `foo' in the namespace of 'b'
3574 and find A::foo. GDB now supports this. This construct is commonly
3575 used in the Standard Template Library for operators.
3577 ** Improved User Defined Operator Support
3579 In addition to member operators, GDB now supports lookup of operators
3580 defined in a namespace and imported with a `using' directive, operators
3581 defined in the global scope, operators imported implicitly from an
3582 anonymous namespace, and the ADL operators mentioned in the previous
3584 GDB now also supports proper overload resolution for all the previously
3585 mentioned flavors of operators.
3587 ** static const class members
3589 Printing of static const class members that are initialized in the
3590 class definition has been fixed.
3592 * Windows Thread Information Block access.
3594 On Windows targets, GDB now supports displaying the Windows Thread
3595 Information Block (TIB) structure. This structure is visible either
3596 by using the new command `info w32 thread-information-block' or, by
3597 dereferencing the new convenience variable named `$_tlb', a
3598 thread-specific pointer to the TIB. This feature is also supported
3599 when remote debugging using GDBserver.
3601 * Static tracepoints
3603 Static tracepoints are calls in the user program into a tracing
3604 library. One such library is a port of the LTTng kernel tracer to
3605 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3606 When debugging with GDBserver, GDB now supports combining the GDB
3607 tracepoint machinery with such libraries. For example: the user can
3608 use GDB to probe a static tracepoint marker (a call from the user
3609 program into the tracing library) with the new "strace" command (see
3610 "New commands" below). This creates a "static tracepoint" in the
3611 breakpoint list, that can be manipulated with the same feature set
3612 as fast and regular tracepoints. E.g., collect registers, local and
3613 global variables, collect trace state variables, and define
3614 tracepoint conditions. In addition, the user can collect extra
3615 static tracepoint marker specific data, by collecting the new
3616 $_sdata internal variable. When analyzing the trace buffer, you can
3617 inspect $_sdata like any other variable available to GDB. For more
3618 information, see the "Tracepoints" chapter in GDB user manual. New
3619 remote packets have been defined to support static tracepoints, see
3620 the "New remote packets" section below.
3622 * Better reconstruction of tracepoints after disconnected tracing
3624 GDB will attempt to download the original source form of tracepoint
3625 definitions when starting a trace run, and then will upload these
3626 upon reconnection to the target, resulting in a more accurate
3627 reconstruction of the tracepoints that are in use on the target.
3631 You can now exercise direct control over the ways that GDB can
3632 affect your program. For instance, you can disallow the setting of
3633 breakpoints, so that the program can run continuously (assuming
3634 non-stop mode). In addition, the "observer" variable is available
3635 to switch all of the different controls; in observer mode, GDB
3636 cannot affect the target's behavior at all, which is useful for
3637 tasks like diagnosing live systems in the field.
3639 * The new convenience variable $_thread holds the number of the
3642 * New remote packets
3646 Return the address of the Windows Thread Information Block of a given thread.
3650 In response to several of the tracepoint packets, the target may now
3651 also respond with a number of intermediate `qRelocInsn' request
3652 packets before the final result packet, to have GDB handle
3653 relocating an instruction to execute at a different address. This
3654 is particularly useful for stubs that support fast tracepoints. GDB
3655 reports support for this feature in the qSupported packet.
3659 List static tracepoint markers in the target program.
3663 List static tracepoint markers at a given address in the target
3666 qXfer:statictrace:read
3668 Read the static trace data collected (by a `collect $_sdata'
3669 tracepoint action). The remote stub reports support for this packet
3670 to gdb's qSupported query.
3674 Send the current settings of GDB's permission flags.
3678 Send part of the source (textual) form of a tracepoint definition,
3679 which includes location, conditional, and action list.
3681 * The source command now accepts a -s option to force searching for the
3682 script in the source search path even if the script name specifies
3685 * New features in the GDB remote stub, GDBserver
3687 - GDBserver now support tracepoints (including fast tracepoints, and
3688 static tracepoints). The feature is currently supported by the
3689 i386-linux and amd64-linux builds. See the "Tracepoints support
3690 in gdbserver" section in the manual for more information.
3692 GDBserver JIT compiles the tracepoint's conditional agent
3693 expression bytecode into native code whenever possible for low
3694 overhead dynamic tracepoints conditionals. For such tracepoints,
3695 an expression that examines program state is evaluated when the
3696 tracepoint is reached, in order to determine whether to capture
3697 trace data. If the condition is simple and false, processing the
3698 tracepoint finishes very quickly and no data is gathered.
3700 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3701 for static tracepoints support.
3703 - GDBserver now supports x86_64 Windows 64-bit debugging.
3705 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3706 it understands register description.
3708 * The --batch flag now disables pagination and queries.
3710 * X86 general purpose registers
3712 GDB now supports reading/writing byte, word and double-word x86
3713 general purpose registers directly. This means you can use, say,
3714 $ah or $ax to refer, respectively, to the byte register AH and
3715 16-bit word register AX that are actually portions of the 32-bit
3716 register EAX or 64-bit register RAX.
3718 * The `commands' command now accepts a range of breakpoints to modify.
3719 A plain `commands' following a command that creates multiple
3720 breakpoints affects all the breakpoints set by that command. This
3721 applies to breakpoints set by `rbreak', and also applies when a
3722 single `break' command creates multiple breakpoints (e.g.,
3723 breakpoints on overloaded c++ functions).
3725 * The `rbreak' command now accepts a filename specification as part of
3726 its argument, limiting the functions selected by the regex to those
3727 in the specified file.
3729 * Support for remote debugging Windows and SymbianOS shared libraries
3730 from Unix hosts has been improved. Non Windows GDB builds now can
3731 understand target reported file names that follow MS-DOS based file
3732 system semantics, such as file names that include drive letters and
3733 use the backslash character as directory separator. This makes it
3734 possible to transparently use the "set sysroot" and "set
3735 solib-search-path" on Unix hosts to point as host copies of the
3736 target's shared libraries. See the new command "set
3737 target-file-system-kind" described below, and the "Commands to
3738 specify files" section in the user manual for more information.
3742 eval template, expressions...
3743 Convert the values of one or more expressions under the control
3744 of the string template to a command line, and call it.
3746 set target-file-system-kind unix|dos-based|auto
3747 show target-file-system-kind
3748 Set or show the assumed file system kind for target reported file
3751 save breakpoints <filename>
3752 Save all current breakpoint definitions to a file suitable for use
3753 in a later debugging session. To read the saved breakpoint
3754 definitions, use the `source' command.
3756 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3759 info static-tracepoint-markers
3760 Display information about static tracepoint markers in the target.
3762 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3763 Define a static tracepoint by probing a marker at the given
3764 function, line, address, or marker ID.
3768 Enable and disable observer mode.
3770 set may-write-registers on|off
3771 set may-write-memory on|off
3772 set may-insert-breakpoints on|off
3773 set may-insert-tracepoints on|off
3774 set may-insert-fast-tracepoints on|off
3775 set may-interrupt on|off
3776 Set individual permissions for GDB effects on the target. Note that
3777 some of these settings can have undesirable or surprising
3778 consequences, particularly when changed in the middle of a session.
3779 For instance, disabling the writing of memory can prevent
3780 breakpoints from being inserted, cause single-stepping to fail, or
3781 even crash your program, if you disable after breakpoints have been
3782 inserted. However, GDB should not crash.
3784 set record memory-query on|off
3785 show record memory-query
3786 Control whether to stop the inferior if memory changes caused
3787 by an instruction cannot be recorded.
3792 The disassemble command now supports "start,+length" form of two arguments.
3796 ** GDB now provides a new directory location, called the python directory,
3797 where Python scripts written for GDB can be installed. The location
3798 of that directory is <data-directory>/python, where <data-directory>
3799 is the GDB data directory. For more details, see section `Scripting
3800 GDB using Python' in the manual.
3802 ** The GDB Python API now has access to breakpoints, symbols, symbol
3803 tables, program spaces, inferiors, threads and frame's code blocks.
3804 Additionally, GDB Parameters can now be created from the API, and
3805 manipulated via set/show in the CLI.
3807 ** New functions gdb.target_charset, gdb.target_wide_charset,
3808 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3810 ** New exception gdb.GdbError.
3812 ** Pretty-printers are now also looked up in the current program space.
3814 ** Pretty-printers can now be individually enabled and disabled.
3816 ** GDB now looks for names of Python scripts to auto-load in a
3817 special section named `.debug_gdb_scripts', in addition to looking
3818 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3820 * Tracepoint actions were unified with breakpoint commands. In particular,
3821 there are no longer differences in "info break" output for breakpoints and
3822 tracepoints and the "commands" command can be used for both tracepoints and
3823 regular breakpoints.
3827 ARM Symbian arm*-*-symbianelf*
3829 * D language support.
3830 GDB now supports debugging programs written in the D programming
3833 * GDB now supports the extended ptrace interface for PowerPC which is
3834 available since Linux kernel version 2.6.34. This automatically enables
3835 any hardware breakpoints and additional hardware watchpoints available in
3836 the processor. The old ptrace interface exposes just one hardware
3837 watchpoint and no hardware breakpoints.
3839 * GDB is now able to use the Data Value Compare (DVC) register available on
3840 embedded PowerPC processors to implement in hardware simple watchpoint
3841 conditions of the form:
3843 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3845 This works in native GDB running on Linux kernels with the extended ptrace
3846 interface mentioned above.
3848 *** Changes in GDB 7.1
3852 ** Namespace Support
3854 GDB now supports importing of namespaces in C++. This enables the
3855 user to inspect variables from imported namespaces. Support for
3856 namepace aliasing has also been added. So, if a namespace is
3857 aliased in the current scope (e.g. namepace C=A; ) the user can
3858 print variables using the alias (e.g. (gdb) print C::x).
3862 All known bugs relating to the printing of virtual base class were
3863 fixed. It is now possible to call overloaded static methods using a
3868 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3869 and reinterpret_cast<> are now handled by the C++ expression parser.
3873 Xilinx MicroBlaze microblaze-*-*
3878 Xilinx MicroBlaze microblaze
3881 * Multi-program debugging.
3883 GDB now has support for multi-program (a.k.a. multi-executable or
3884 multi-exec) debugging. This allows for debugging multiple inferiors
3885 simultaneously each running a different program under the same GDB
3886 session. See "Debugging Multiple Inferiors and Programs" in the
3887 manual for more information. This implied some user visible changes
3888 in the multi-inferior support. For example, "info inferiors" now
3889 lists inferiors that are not running yet or that have exited
3890 already. See also "New commands" and "New options" below.
3892 * New tracing features
3894 GDB's tracepoint facility now includes several new features:
3896 ** Trace state variables
3898 GDB tracepoints now include support for trace state variables, which
3899 are variables managed by the target agent during a tracing
3900 experiment. They are useful for tracepoints that trigger each
3901 other, so for instance one tracepoint can count hits in a variable,
3902 and then a second tracepoint has a condition that is true when the
3903 count reaches a particular value. Trace state variables share the
3904 $-syntax of GDB convenience variables, and can appear in both
3905 tracepoint actions and condition expressions. Use the "tvariable"
3906 command to create, and "info tvariables" to view; see "Trace State
3907 Variables" in the manual for more detail.
3911 GDB now includes an option for defining fast tracepoints, which
3912 targets may implement more efficiently, such as by installing a jump
3913 into the target agent rather than a trap instruction. The resulting
3914 speedup can be by two orders of magnitude or more, although the
3915 tradeoff is that some program locations on some target architectures
3916 might not allow fast tracepoint installation, for instance if the
3917 instruction to be replaced is shorter than the jump. To request a
3918 fast tracepoint, use the "ftrace" command, with syntax identical to
3919 the regular trace command.
3921 ** Disconnected tracing
3923 It is now possible to detach GDB from the target while it is running
3924 a trace experiment, then reconnect later to see how the experiment
3925 is going. In addition, a new variable disconnected-tracing lets you
3926 tell the target agent whether to continue running a trace if the
3927 connection is lost unexpectedly.
3931 GDB now has the ability to save the trace buffer into a file, and
3932 then use that file as a target, similarly to you can do with
3933 corefiles. You can select trace frames, print data that was
3934 collected in them, and use tstatus to display the state of the
3935 tracing run at the moment that it was saved. To create a trace
3936 file, use "tsave <filename>", and to use it, do "target tfile
3939 ** Circular trace buffer
3941 You can ask the target agent to handle the trace buffer as a
3942 circular buffer, discarding the oldest trace frames to make room for
3943 newer ones, by setting circular-trace-buffer to on. This feature may
3944 not be available for all target agents.
3949 The disassemble command, when invoked with two arguments, now requires
3950 the arguments to be comma-separated.
3953 The info variables command now displays variable definitions. Files
3954 which only declare a variable are not shown.
3957 The source command is now capable of sourcing Python scripts.
3958 This feature is dependent on the debugger being build with Python
3961 Related to this enhancement is also the introduction of a new command
3962 "set script-extension" (see below).
3964 * New commands (for set/show, see "New options" below)
3966 record save [<FILENAME>]
3967 Save a file (in core file format) containing the process record
3968 execution log for replay debugging at a later time.
3970 record restore <FILENAME>
3971 Restore the process record execution log that was saved at an
3972 earlier time, for replay debugging.
3974 add-inferior [-copies <N>] [-exec <FILENAME>]
3977 clone-inferior [-copies <N>] [ID]
3978 Make a new inferior ready to execute the same program another
3979 inferior has loaded.
3984 maint info program-spaces
3985 List the program spaces loaded into GDB.
3987 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3988 show remote interrupt-sequence
3989 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3990 as the sequence to the remote target in order to interrupt the execution.
3991 Ctrl-C is a default. Some system prefers BREAK which is high level of
3992 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3993 Magic SysRq g. It is BREAK signal and character 'g'.
3995 set remote interrupt-on-connect [on | off]
3996 show remote interrupt-on-connect
3997 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3998 remote target when gdb connects to it. This is needed when you debug
4001 set remotebreak [on | off]
4003 Deprecated. Use "set/show remote interrupt-sequence" instead.
4005 tvariable $NAME [ = EXP ]
4006 Create or modify a trace state variable.
4009 List trace state variables and their values.
4011 delete tvariable $NAME ...
4012 Delete one or more trace state variables.
4015 Evaluate the given expressions without collecting anything into the
4016 trace buffer. (Valid in tracepoint actions only.)
4018 ftrace FN / FILE:LINE / *ADDR
4019 Define a fast tracepoint at the given function, line, or address.
4021 * New expression syntax
4023 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4024 GDB now parses 0b101010 identically with 42.
4028 set follow-exec-mode new|same
4029 show follow-exec-mode
4030 Control whether GDB reuses the same inferior across an exec call or
4031 creates a new one. This is useful to be able to restart the old
4032 executable after the inferior having done an exec call.
4034 set default-collect EXPR, ...
4035 show default-collect
4036 Define a list of expressions to be collected at each tracepoint.
4037 This is a useful way to ensure essential items are not overlooked,
4038 such as registers or a critical global variable.
4040 set disconnected-tracing
4041 show disconnected-tracing
4042 If set to 1, the target is instructed to continue tracing if it
4043 loses its connection to GDB. If 0, the target is to stop tracing
4046 set circular-trace-buffer
4047 show circular-trace-buffer
4048 If set to on, the target is instructed to use a circular trace buffer
4049 and discard the oldest trace frames instead of stopping the trace due
4050 to a full trace buffer. If set to off, the trace stops when the buffer
4051 fills up. Some targets may not support this.
4053 set script-extension off|soft|strict
4054 show script-extension
4055 If set to "off", the debugger does not perform any script language
4056 recognition, and all sourced files are assumed to be GDB scripts.
4057 If set to "soft" (the default), files are sourced according to
4058 filename extension, falling back to GDB scripts if the first
4060 If set to "strict", files are sourced according to filename extension.
4062 set ada trust-PAD-over-XVS on|off
4063 show ada trust-PAD-over-XVS
4064 If off, activate a workaround against a bug in the debugging information
4065 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4066 the GCC sources for more information about the GNAT encoding and
4067 PAD types in particular). It is always safe to set this option to
4068 off, but this introduces a slight performance penalty. The default
4071 * Python API Improvements
4073 ** GDB provides the new class gdb.LazyString. This is useful in
4074 some pretty-printing cases. The new method gdb.Value.lazy_string
4075 provides a simple way to create objects of this type.
4077 ** The fields returned by gdb.Type.fields now have an
4078 `is_base_class' attribute.
4080 ** The new method gdb.Type.range returns the range of an array type.
4082 ** The new method gdb.parse_and_eval can be used to parse and
4083 evaluate an expression.
4085 * New remote packets
4088 Define a trace state variable.
4091 Get the current value of a trace state variable.
4094 Set desired tracing behavior upon disconnection.
4097 Set the trace buffer to be linear or circular.
4100 Get data about the tracepoints currently in use.
4104 Process record now works correctly with hardware watchpoints.
4106 Multiple bug fixes have been made to the mips-irix port, making it
4107 much more reliable. In particular:
4108 - Debugging threaded applications is now possible again. Previously,
4109 GDB would hang while starting the program, or while waiting for
4110 the program to stop at a breakpoint.
4111 - Attaching to a running process no longer hangs.
4112 - An error occurring while loading a core file has been fixed.
4113 - Changing the value of the PC register now works again. This fixes
4114 problems observed when using the "jump" command, or when calling
4115 a function from GDB, or even when assigning a new value to $pc.
4116 - With the "finish" and "return" commands, the return value for functions
4117 returning a small array is now correctly printed.
4118 - It is now possible to break on shared library code which gets executed
4119 during a shared library init phase (code executed while executing
4120 their .init section). Previously, the breakpoint would have no effect.
4121 - GDB is now able to backtrace through the signal handler for
4122 non-threaded programs.
4124 PIE (Position Independent Executable) programs debugging is now supported.
4125 This includes debugging execution of PIC (Position Independent Code) shared
4126 libraries although for that, it should be possible to run such libraries as an
4129 *** Changes in GDB 7.0
4131 * GDB now has an interface for JIT compilation. Applications that
4132 dynamically generate code can create symbol files in memory and register
4133 them with GDB. For users, the feature should work transparently, and
4134 for JIT developers, the interface is documented in the GDB manual in the
4135 "JIT Compilation Interface" chapter.
4137 * Tracepoints may now be conditional. The syntax is as for
4138 breakpoints; either an "if" clause appended to the "trace" command,
4139 or the "condition" command is available. GDB sends the condition to
4140 the target for evaluation using the same bytecode format as is used
4141 for tracepoint actions.
4143 * The disassemble command now supports: an optional /r modifier, print the
4144 raw instructions in hex as well as in symbolic form, and an optional /m
4145 modifier to print mixed source+assembly.
4147 * Process record and replay
4149 In a architecture environment that supports ``process record and
4150 replay'', ``process record and replay'' target can record a log of
4151 the process execution, and replay it with both forward and reverse
4154 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4155 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4156 set execution-direction {forward|reverse}, for targets that support
4159 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4160 feature is available with a native GDB running on kernel version
4163 * GDB now has support for multi-byte and wide character sets on the
4164 target. Strings whose character type is wchar_t, char16_t, or
4165 char32_t are now correctly printed. GDB supports wide- and unicode-
4166 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4167 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4168 `printf'. This feature requires iconv to work properly; if your
4169 system does not have a working iconv, GDB can use GNU libiconv. See
4170 the installation instructions for more information.
4172 * GDB now supports automatic retrieval of shared library files from
4173 remote targets. To use this feature, specify a system root that begins
4174 with the `remote:' prefix, either via the `set sysroot' command or via
4175 the `--with-sysroot' configure-time option.
4177 * "info sharedlibrary" now takes an optional regex of libraries to show,
4178 and it now reports if a shared library has no debugging information.
4180 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4181 now complete on file names.
4183 * When completing in expressions, gdb will attempt to limit
4184 completions to allowable structure or union fields, where appropriate.
4185 For instance, consider:
4187 # struct example { int f1; double f2; };
4188 # struct example variable;
4191 If the user types TAB at the end of this command line, the available
4192 completions will be "f1" and "f2".
4194 * Inlined functions are now supported. They show up in backtraces, and
4195 the "step", "next", and "finish" commands handle them automatically.
4197 * GDB now supports the token-splicing (##) and stringification (#)
4198 operators when expanding macros. It also supports variable-arity
4201 * GDB now supports inspecting extra signal information, exported by
4202 the new $_siginfo convenience variable. The feature is currently
4203 implemented on linux ARM, i386 and amd64.
4205 * GDB can now display the VFP floating point registers and NEON vector
4206 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4207 can provide these registers (requires Linux 2.6.30 or later). Remote
4208 and simulator targets may also provide them.
4210 * New remote packets
4213 Search memory for a sequence of bytes.
4216 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4217 operation over reliable transport links. Use of this packet is
4218 controlled by the `set remote noack-packet' command.
4221 Kill the process with the specified process ID. Use this in preference
4222 to `k' when multiprocess protocol extensions are supported.
4225 Obtains additional operating system information
4229 Read or write additional signal information.
4231 * Removed remote protocol undocumented extension
4233 An undocumented extension to the remote protocol's `S' stop reply
4234 packet that permited the stub to pass a process id was removed.
4235 Remote servers should use the `T' stop reply packet instead.
4237 * GDB now supports multiple function calling conventions according to the
4238 DWARF-2 DW_AT_calling_convention function attribute.
4240 * The SH target utilizes the aforementioned change to distinguish between gcc
4241 and Renesas calling convention. It also adds the new CLI commands
4242 `set/show sh calling-convention'.
4244 * GDB can now read compressed debug sections, as produced by GNU gold
4245 with the --compress-debug-sections=zlib flag.
4247 * 64-bit core files are now supported on AIX.
4249 * Thread switching is now supported on Tru64.
4251 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4252 which will be allocated using malloc later in program execution.
4254 * The qXfer:libraries:read remote procotol packet now allows passing a
4255 list of section offsets.
4257 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4258 conditions handling signals delivered during attach or thread creation
4259 have also been fixed.
4261 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4262 From the user's standpoint, all unqualified instances of True and False
4263 are treated as the standard definitions, regardless of context.
4265 * GDB now parses C++ symbol and type names more flexibly. For
4268 template<typename T> class C { };
4271 GDB will now correctly handle all of:
4273 ptype C<char const *>
4274 ptype C<char const*>
4275 ptype C<const char *>
4276 ptype C<const char*>
4278 * New features in the GDB remote stub, gdbserver
4280 - The "--wrapper" command-line argument tells gdbserver to use a
4281 wrapper program to launch programs for debugging.
4283 - On PowerPC and S/390 targets, it is now possible to use a single
4284 gdbserver executable to debug both 32-bit and 64-bit programs.
4285 (This requires gdbserver itself to be built as a 64-bit executable.)
4287 - gdbserver uses the new noack protocol mode for TCP connections to
4288 reduce communications latency, if also supported and enabled in GDB.
4290 - Support for the sparc64-linux-gnu target is now included in
4293 - The amd64-linux build of gdbserver now supports debugging both
4294 32-bit and 64-bit programs.
4296 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4297 now support hardware watchpoints, and will use them automatically
4302 GDB now has support for scripting using Python. Whether this is
4303 available is determined at configure time.
4305 New GDB commands can now be written in Python.
4307 * Ada tasking support
4309 Ada tasks can now be inspected in GDB. The following commands have
4313 Print the list of Ada tasks.
4315 Print detailed information about task number N.
4317 Print the task number of the current task.
4319 Switch the context of debugging to task number N.
4321 * Support for user-defined prefixed commands. The "define" command can
4322 add new commands to existing prefixes, e.g. "target".
4324 * Multi-inferior, multi-process debugging.
4326 GDB now has generalized support for multi-inferior debugging. See
4327 "Debugging Multiple Inferiors" in the manual for more information.
4328 Although availability still depends on target support, the command
4329 set is more uniform now. The GNU/Linux specific multi-forks support
4330 has been migrated to this new framework. This implied some user
4331 visible changes; see "New commands" and also "Removed commands"
4334 * Target descriptions can now describe the target OS ABI. See the
4335 "Target Description Format" section in the user manual for more
4338 * Target descriptions can now describe "compatible" architectures
4339 to indicate that the target can execute applications for a different
4340 architecture in addition to those for the main target architecture.
4341 See the "Target Description Format" section in the user manual for
4344 * Multi-architecture debugging.
4346 GDB now includes general supports for debugging applications on
4347 hybrid systems that use more than one single processor architecture
4348 at the same time. Each such hybrid architecture still requires
4349 specific support to be added. The only hybrid architecture supported
4350 in this version of GDB is the Cell Broadband Engine.
4352 * GDB now supports integrated debugging of Cell/B.E. applications that
4353 use both the PPU and SPU architectures. To enable support for hybrid
4354 Cell/B.E. debugging, you need to configure GDB to support both the
4355 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4356 --enable-targets configure option.
4358 * Non-stop mode debugging.
4360 For some targets, GDB now supports an optional mode of operation in
4361 which you can examine stopped threads while other threads continue
4362 to execute freely. This is referred to as non-stop mode, with the
4363 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4364 section in the user manual for more information.
4366 To be able to support remote non-stop debugging, a remote stub needs
4367 to implement the non-stop mode remote protocol extensions, as
4368 described in the "Remote Non-Stop" section of the user manual. The
4369 GDB remote stub, gdbserver, has been adjusted to support these
4370 extensions on linux targets.
4372 * New commands (for set/show, see "New options" below)
4374 catch syscall [NAME(S) | NUMBER(S)]
4375 Catch system calls. Arguments, which should be names of system
4376 calls or their numbers, mean catch only those syscalls. Without
4377 arguments, every syscall will be caught. When the inferior issues
4378 any of the specified syscalls, GDB will stop and announce the system
4379 call, both when it is called and when its call returns. This
4380 feature is currently available with a native GDB running on the
4381 Linux Kernel, under the following architectures: x86, x86_64,
4382 PowerPC and PowerPC64.
4384 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4386 Search memory for a sequence of bytes.
4388 maint set python print-stack
4389 maint show python print-stack
4390 Show a stack trace when an error is encountered in a Python script.
4393 Invoke CODE by passing it to the Python interpreter.
4398 These allow macros to be defined, undefined, and listed
4402 Show operating system information about processes.
4405 List the inferiors currently under GDB's control.
4408 Switch focus to inferior number NUM.
4411 Detach from inferior number NUM.
4414 Kill inferior number NUM.
4418 set spu stop-on-load
4419 show spu stop-on-load
4420 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4422 set spu auto-flush-cache
4423 show spu auto-flush-cache
4424 Control whether to automatically flush the software-managed cache
4425 during Cell/B.E. debugging.
4427 set sh calling-convention
4428 show sh calling-convention
4429 Control the calling convention used when calling SH target functions.
4432 show debug timestamp
4433 Control display of timestamps with GDB debugging output.
4435 set disassemble-next-line
4436 show disassemble-next-line
4437 Control display of disassembled source lines or instructions when
4440 set remote noack-packet
4441 show remote noack-packet
4442 Set/show the use of remote protocol QStartNoAckMode packet. See above
4443 under "New remote packets."
4445 set remote query-attached-packet
4446 show remote query-attached-packet
4447 Control use of remote protocol `qAttached' (query-attached) packet.
4449 set remote read-siginfo-object
4450 show remote read-siginfo-object
4451 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4454 set remote write-siginfo-object
4455 show remote write-siginfo-object
4456 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4459 set remote reverse-continue
4460 show remote reverse-continue
4461 Control use of remote protocol 'bc' (reverse-continue) packet.
4463 set remote reverse-step
4464 show remote reverse-step
4465 Control use of remote protocol 'bs' (reverse-step) packet.
4467 set displaced-stepping
4468 show displaced-stepping
4469 Control displaced stepping mode. Displaced stepping is a way to
4470 single-step over breakpoints without removing them from the debuggee.
4471 Also known as "out-of-line single-stepping".
4474 show debug displaced
4475 Control display of debugging info for displaced stepping.
4477 maint set internal-error
4478 maint show internal-error
4479 Control what GDB does when an internal error is detected.
4481 maint set internal-warning
4482 maint show internal-warning
4483 Control what GDB does when an internal warning is detected.
4488 Use a wrapper program to launch programs for debugging.
4490 set multiple-symbols (all|ask|cancel)
4491 show multiple-symbols
4492 The value of this variable can be changed to adjust the debugger behavior
4493 when an expression or a breakpoint location contains an ambiguous symbol
4494 name (an overloaded function name, for instance).
4496 set breakpoint always-inserted
4497 show breakpoint always-inserted
4498 Keep breakpoints always inserted in the target, as opposed to inserting
4499 them when resuming the target, and removing them when the target stops.
4500 This option can improve debugger performance on slow remote targets.
4502 set arm fallback-mode (arm|thumb|auto)
4503 show arm fallback-mode
4504 set arm force-mode (arm|thumb|auto)
4506 These commands control how ARM GDB determines whether instructions
4507 are ARM or Thumb. The default for both settings is auto, which uses
4508 the current CPSR value for instructions without symbols; previous
4509 versions of GDB behaved as if "set arm fallback-mode arm".
4511 set disable-randomization
4512 show disable-randomization
4513 Standalone programs run with the virtual address space randomization enabled
4514 by default on some platforms. This option keeps the addresses stable across
4515 multiple debugging sessions.
4519 Control whether other threads are stopped or not when some thread hits
4524 Requests that asynchronous execution is enabled in the target, if available.
4525 In this case, it's possible to resume target in the background, and interact
4526 with GDB while the target is running. "show target-async" displays the
4527 current state of asynchronous execution of the target.
4529 set target-wide-charset
4530 show target-wide-charset
4531 The target-wide-charset is the name of the character set that GDB
4532 uses when printing characters whose type is wchar_t.
4534 set tcp auto-retry (on|off)
4536 set tcp connect-timeout
4537 show tcp connect-timeout
4538 These commands allow GDB to retry failed TCP connections to a remote stub
4539 with a specified timeout period; this is useful if the stub is launched
4540 in parallel with GDB but may not be ready to accept connections immediately.
4542 set libthread-db-search-path
4543 show libthread-db-search-path
4544 Control list of directories which GDB will search for appropriate
4547 set schedule-multiple (on|off)
4548 show schedule-multiple
4549 Allow GDB to resume all threads of all processes or only threads of
4550 the current process.
4554 Use more aggressive caching for accesses to the stack. This improves
4555 performance of remote debugging (particularly backtraces) without
4556 affecting correctness.
4558 set interactive-mode (on|off|auto)
4559 show interactive-mode
4560 Control whether GDB runs in interactive mode (on) or not (off).
4561 When in interactive mode, GDB waits for the user to answer all
4562 queries. Otherwise, GDB does not wait and assumes the default
4563 answer. When set to auto (the default), GDB determines which
4564 mode to use based on the stdin settings.
4569 For program forks, this is replaced by the new more generic `info
4570 inferiors' command. To list checkpoints, you can still use the
4571 `info checkpoints' command, which was an alias for the `info forks'
4575 Replaced by the new `inferior' command. To switch between
4576 checkpoints, you can still use the `restart' command, which was an
4577 alias for the `fork' command.
4580 This is removed, since some targets don't have a notion of
4581 processes. To switch between processes, you can still use the
4582 `inferior' command using GDB's own inferior number.
4585 For program forks, this is replaced by the new more generic `kill
4586 inferior' command. To delete a checkpoint, you can still use the
4587 `delete checkpoint' command, which was an alias for the `delete
4591 For program forks, this is replaced by the new more generic `detach
4592 inferior' command. To detach a checkpoint, you can still use the
4593 `detach checkpoint' command, which was an alias for the `detach
4596 * New native configurations
4598 x86/x86_64 Darwin i[34567]86-*-darwin*
4600 x86_64 MinGW x86_64-*-mingw*
4604 Lattice Mico32 lm32-*
4605 x86 DICOS i[34567]86-*-dicos*
4606 x86_64 DICOS x86_64-*-dicos*
4609 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4610 (mingw32ce) debugging.
4616 These commands were actually not implemented on any target.
4618 *** Changes in GDB 6.8
4620 * New native configurations
4622 NetBSD/hppa hppa*-*netbsd*
4623 Xtensa GNU/Linux xtensa*-*-linux*
4627 NetBSD/hppa hppa*-*-netbsd*
4628 Xtensa GNU/Lunux xtensa*-*-linux*
4630 * Change in command line behavior -- corefiles vs. process ids.
4632 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4633 attaching to process NUMBER fails, GDB no longer attempts to open a
4634 core file named NUMBER. Attaching to a program using the -c option
4635 is no longer supported. Instead, use the '-p' or '--pid' options.
4637 * GDB can now be built as a native debugger for debugging Windows x86
4638 (mingw32) Portable Executable (PE) programs.
4640 * Pending breakpoints no longer change their number when their address
4643 * GDB now supports breakpoints with multiple locations,
4644 including breakpoints on C++ constructors, inside C++ templates,
4645 and in inlined functions.
4647 * GDB's ability to debug optimized code has been improved. GDB more
4648 accurately identifies function bodies and lexical blocks that occupy
4649 more than one contiguous range of addresses.
4651 * Target descriptions can now describe registers for PowerPC.
4653 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4654 registers on PowerPC targets.
4656 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4657 targets even when the libthread_db library is not available.
4659 * The GDB remote stub, gdbserver, now supports the new file transfer
4660 commands (remote put, remote get, and remote delete).
4662 * The GDB remote stub, gdbserver, now supports run and attach in
4663 extended-remote mode.
4665 * hppa*64*-*-hpux11* target broken
4666 The debugger is unable to start a program and fails with the following
4667 error: "Error trying to get information about dynamic linker".
4668 The gdb-6.7 release is also affected.
4670 * GDB now supports the --enable-targets= configure option to allow
4671 building a single GDB executable that supports multiple remote
4672 target architectures.
4674 * GDB now supports debugging C and C++ programs which use the
4675 Decimal Floating Point extension. In addition, the PowerPC target
4676 now has a set of pseudo-registers to inspect decimal float values
4677 stored in two consecutive float registers.
4679 * The -break-insert MI command can optionally create pending
4682 * Improved support for debugging Ada
4683 Many improvements to the Ada language support have been made. These
4685 - Better support for Ada2005 interface types
4686 - Improved handling of arrays and slices in general
4687 - Better support for Taft-amendment types
4688 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4690 - Improved command completion in Ada
4693 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4698 set print frame-arguments (all|scalars|none)
4699 show print frame-arguments
4700 The value of this variable can be changed to control which argument
4701 values should be printed by the debugger when displaying a frame.
4706 Transfer files to and from a remote target, and delete remote files.
4713 Transfer files to and from a remote target, and delete remote files.
4715 * New remote packets
4722 Open, close, read, write, and delete files on the remote system.
4725 Attach to an existing process on the remote system, in extended-remote
4729 Run a new process on the remote system, in extended-remote mode.
4731 *** Changes in GDB 6.7
4733 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4734 bfd, libiberty and opcodes, as revealed by static analysis donated by
4735 Coverity, Inc. (http://scan.coverity.com).
4737 * When looking up multiply-defined global symbols, GDB will now prefer the
4738 symbol definition in the current shared library if it was built using the
4739 -Bsymbolic linker option.
4741 * When the Text User Interface (TUI) is not configured, GDB will now
4742 recognize the -tui command-line option and print a message that the TUI
4745 * The GDB remote stub, gdbserver, now has lower overhead for high
4746 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4748 * GDB for MIPS targets now autodetects whether a remote target provides
4749 32-bit or 64-bit register values.
4751 * Support for C++ member pointers has been improved.
4753 * GDB now understands XML target descriptions, which specify the
4754 target's overall architecture. GDB can read a description from
4755 a local file or over the remote serial protocol.
4757 * Vectors of single-byte data use a new integer type which is not
4758 automatically displayed as character or string data.
4760 * The /s format now works with the print command. It displays
4761 arrays of single-byte integers and pointers to single-byte integers
4764 * Target descriptions can now describe target-specific registers,
4765 for architectures which have implemented the support (currently
4766 only ARM, M68K, and MIPS).
4768 * GDB and the GDB remote stub, gdbserver, now support the XScale
4771 * The GDB remote stub, gdbserver, has been updated to support
4772 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4773 has been rewritten to use the standard GDB remote protocol.
4775 * GDB can now step into C++ functions which are called through thunks.
4777 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4779 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4780 layout. It also supports a TextSeg= and DataSeg= response when only
4781 segment base addresses (rather than offsets) are available.
4783 * The /i format now outputs any trailing branch delay slot instructions
4784 immediately following the last instruction within the count specified.
4786 * The GDB remote protocol "T" stop reply packet now supports a
4787 "library" response. Combined with the new "qXfer:libraries:read"
4788 packet, this response allows GDB to debug shared libraries on targets
4789 where the operating system manages the list of loaded libraries (e.g.
4790 Windows and SymbianOS).
4792 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4793 (DLLs) on Windows and Windows CE targets.
4795 * GDB now supports a faster verification that a .debug file matches its binary
4796 according to its build-id signature, if the signature is present.
4802 Enable or disable hardware flow control (RTS/CTS) on the serial port
4803 when debugging using remote targets.
4805 set mem inaccessible-by-default
4806 show mem inaccessible-by-default
4807 If the target supplies a memory map, for instance via the remote
4808 protocol's "qXfer:memory-map:read" packet, setting this variable
4809 prevents GDB from accessing memory outside the memory map. This
4810 is useful for targets with memory mapped registers or which react
4811 badly to accesses of unmapped address space.
4813 set breakpoint auto-hw
4814 show breakpoint auto-hw
4815 If the target supplies a memory map, for instance via the remote
4816 protocol's "qXfer:memory-map:read" packet, setting this variable
4817 lets GDB use hardware breakpoints automatically for memory regions
4818 where it can not use software breakpoints. This covers both the
4819 "break" command and internal breakpoints used for other commands
4820 including "next" and "finish".
4823 catch exception unhandled
4824 Stop the program execution when Ada exceptions are raised.
4827 Stop the program execution when an Ada assertion failed.
4831 Set an alternate system root for target files. This is a more
4832 general version of "set solib-absolute-prefix", which is now
4833 an alias to "set sysroot".
4836 Provide extended SPU facility status information. This set of
4837 commands is available only when debugging the Cell/B.E. SPU
4840 * New native configurations
4842 OpenBSD/sh sh*-*openbsd*
4845 unset tdesc filename
4847 Use the specified local file as an XML target description, and do
4848 not query the target for its built-in description.
4852 OpenBSD/sh sh*-*-openbsd*
4853 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4854 Toshiba Media Processor mep-elf
4856 * New remote packets
4859 Ignore the specified signals; pass them directly to the debugged program
4860 without stopping other threads or reporting them to GDB.
4862 qXfer:features:read:
4863 Read an XML target description from the target, which describes its
4868 Read or write contents of an spufs file on the target system. These
4869 packets are available only on the Cell/B.E. SPU architecture.
4871 qXfer:libraries:read:
4872 Report the loaded shared libraries. Combined with new "T" packet
4873 response, this packet allows GDB to debug shared libraries on
4874 targets where the operating system manages the list of loaded
4875 libraries (e.g. Windows and SymbianOS).
4879 Support for these obsolete configurations has been removed.
4887 i[34567]86-*-lynxos*
4888 i[34567]86-*-netware*
4889 i[34567]86-*-sco3.2v5*
4890 i[34567]86-*-sco3.2v4*
4892 i[34567]86-*-sysv4.2*
4895 i[34567]86-*-unixware2*
4896 i[34567]86-*-unixware*
4905 * Other removed features
4912 Various m68k-only ROM monitors.
4919 Various Renesas ROM monitors and debugging interfaces for SH and
4924 Support for a Macraigor serial interface to on-chip debugging.
4925 GDB does not directly support the newer parallel or USB
4930 A debug information format. The predecessor to DWARF 2 and
4931 DWARF 3, which are still supported.
4933 Support for the HP aCC compiler on HP-UX/PA-RISC
4935 SOM-encapsulated symbolic debugging information, automatic
4936 invocation of pxdb, and the aCC custom C++ ABI. This does not
4937 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4938 with aCC can still be debugged on an assembly level.
4940 MIPS ".pdr" sections
4942 A MIPS-specific format used to describe stack frame layout
4943 in debugging information.
4947 GDB could work with an older version of Guile to debug
4948 the interpreter and Scheme programs running in it.
4950 set mips stack-arg-size
4951 set mips saved-gpreg-size
4953 Use "set mips abi" to control parameter passing for MIPS.
4955 *** Changes in GDB 6.6
4960 Cell Broadband Engine SPU spu-elf
4962 * GDB can now be configured as a cross-debugger targeting native Windows
4963 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4964 running on a Windows system over TCP/IP to debug Windows programs.
4966 * The GDB remote stub, gdbserver, has been updated to support Windows and
4967 Cygwin debugging. Both single-threaded and multi-threaded programs are
4970 * The "set trust-readonly-sections" command works again. This command was
4971 broken in GDB 6.3, 6.4, and 6.5.
4973 * The "load" command now supports writing to flash memory, if the remote
4974 stub provides the required support.
4976 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4977 longer requires symbolic debug information (e.g. DWARF-2).
4982 unset substitute-path
4983 show substitute-path
4984 Manage a list of substitution rules that GDB uses to rewrite the name
4985 of the directories where the sources are located. This can be useful
4986 for instance when the sources were moved to a different location
4987 between compilation and debugging.
4991 Print each CLI command as it is executed. Each command is prefixed with
4992 a number of `+' symbols representing the nesting depth.
4993 The source command now has a `-v' option to enable the same feature.
4997 The ARM Demon monitor support (RDP protocol, "target rdp").
4999 Kernel Object Display, an embedded debugging feature which only worked with
5000 an obsolete version of Cisco IOS.
5002 The 'set download-write-size' and 'show download-write-size' commands.
5004 * New remote packets
5007 Tell a stub about GDB client features, and request remote target features.
5008 The first feature implemented is PacketSize, which allows the target to
5009 specify the size of packets it can handle - to minimize the number of
5010 packets required and improve performance when connected to a remote
5014 Fetch an OS auxilliary vector from the remote stub. This packet is a
5015 more efficient replacement for qPart:auxv:read.
5017 qXfer:memory-map:read:
5018 Fetch a memory map from the remote stub, including information about
5019 RAM, ROM, and flash memory devices.
5024 Erase and program a flash memory device.
5026 * Removed remote packets
5029 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5030 used it, and only gdbserver implemented it.
5032 *** Changes in GDB 6.5
5036 Renesas M32C/M16C m32c-elf
5038 Morpho Technologies ms1 ms1-elf
5042 init-if-undefined Initialize a convenience variable, but
5043 only if it doesn't already have a value.
5045 The following commands are presently only implemented for native GNU/Linux:
5047 checkpoint Save a snapshot of the program state.
5049 restart <n> Return the program state to a
5050 previously saved state.
5052 info checkpoints List currently saved checkpoints.
5054 delete-checkpoint <n> Delete a previously saved checkpoint.
5056 set|show detach-on-fork Tell gdb whether to detach from a newly
5057 forked process, or to keep debugging it.
5059 info forks List forks of the user program that
5060 are available to be debugged.
5062 fork <n> Switch to debugging one of several
5063 forks of the user program that are
5064 available to be debugged.
5066 delete-fork <n> Delete a fork from the list of forks
5067 that are available to be debugged (and
5068 kill the forked process).
5070 detach-fork <n> Delete a fork from the list of forks
5071 that are available to be debugged (and
5072 allow the process to continue).
5076 Morpho Technologies ms2 ms1-elf
5078 * Improved Windows host support
5080 GDB now builds as a cross debugger hosted on i686-mingw32, including
5081 native console support, and remote communications using either
5082 network sockets or serial ports.
5084 * Improved Modula-2 language support
5086 GDB can now print most types in the Modula-2 syntax. This includes:
5087 basic types, set types, record types, enumerated types, range types,
5088 pointer types and ARRAY types. Procedure var parameters are correctly
5089 printed and hexadecimal addresses and character constants are also
5090 written in the Modula-2 syntax. Best results can be obtained by using
5091 GNU Modula-2 together with the -gdwarf-2 command line option.
5095 The ARM rdi-share module.
5097 The Netware NLM debug server.
5099 *** Changes in GDB 6.4
5101 * New native configurations
5103 OpenBSD/arm arm*-*-openbsd*
5104 OpenBSD/mips64 mips64-*-openbsd*
5108 Morpho Technologies ms1 ms1-elf
5110 * New command line options
5112 --batch-silent As for --batch, but totally silent.
5113 --return-child-result The debugger will exist with the same value
5114 the child (debugged) program exited with.
5115 --eval-command COMMAND, -ex COMMAND
5116 Execute a single GDB CLI command. This may be
5117 specified multiple times and in conjunction
5118 with the --command (-x) option.
5120 * Deprecated commands removed
5122 The following commands, that were deprecated in 2000, have been
5126 set|show arm disassembly-flavor set|show arm disassembler
5127 othernames set arm disassembler
5128 set|show remotedebug set|show debug remote
5129 set|show archdebug set|show debug arch
5130 set|show eventdebug set|show debug event
5133 * New BSD user-level threads support
5135 It is now possible to debug programs using the user-level threads
5136 library on OpenBSD and FreeBSD. Currently supported (target)
5139 FreeBSD/amd64 x86_64-*-freebsd*
5140 FreeBSD/i386 i386-*-freebsd*
5141 OpenBSD/i386 i386-*-openbsd*
5143 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5144 are not yet supported.
5146 * New support for Matsushita MN10300 w/sim added
5147 (Work in progress). mn10300-elf.
5149 * REMOVED configurations and files
5151 VxWorks and the XDR protocol *-*-vxworks
5152 Motorola MCORE mcore-*-*
5153 National Semiconductor NS32000 ns32k-*-*
5155 * New "set print array-indexes" command
5157 After turning this setting "on", GDB prints the index of each element
5158 when displaying arrays. The default is "off" to preserve the previous
5161 * VAX floating point support
5163 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5165 * User-defined command support
5167 In addition to using $arg0..$arg9 for argument passing, it is now possible
5168 to use $argc to determine now many arguments have been passed. See the
5169 section on user-defined commands in the user manual for more information.
5171 *** Changes in GDB 6.3:
5173 * New command line option
5175 GDB now accepts -l followed by a number to set the timeout for remote
5178 * GDB works with GCC -feliminate-dwarf2-dups
5180 GDB now supports a more compact representation of DWARF-2 debug
5181 information using DW_FORM_ref_addr references. These are produced
5182 by GCC with the option -feliminate-dwarf2-dups and also by some
5183 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5184 to use -feliminate-dwarf2-dups.
5186 * Internationalization
5188 When supported by the host system, GDB will be built with
5189 internationalization (libintl). The task of marking up the sources is
5190 continued, we're looking forward to our first translation.
5194 Initial support for debugging programs compiled with the GNAT
5195 implementation of the Ada programming language has been integrated
5196 into GDB. In this release, support is limited to expression evaluation.
5198 * New native configurations
5200 GNU/Linux/m32r m32r-*-linux-gnu
5204 GDB's remote protocol now includes support for the 'p' packet. This
5205 packet is used to fetch individual registers from a remote inferior.
5207 * END-OF-LIFE registers[] compatibility module
5209 GDB's internal register infrastructure has been completely rewritten.
5210 The new infrastructure making possible the implementation of key new
5211 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5214 GDB 6.3 will be the last release to include the registers[]
5215 compatibility module that allowed out-of-date configurations to
5216 continue to work. This change directly impacts the following
5226 powerpc bdm protocol
5228 Unless there is activity to revive these configurations, they will be
5229 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5231 * OBSOLETE configurations and files
5233 Configurations that have been declared obsolete in this release have
5234 been commented out. Unless there is activity to revive these
5235 configurations, the next release of GDB will have their sources
5236 permanently REMOVED.
5245 *** Changes in GDB 6.2.1:
5247 * MIPS `break main; run' gave an heuristic-fence-post warning
5249 When attempting to run even a simple program, a warning about
5250 heuristic-fence-post being hit would be reported. This problem has
5253 * MIPS IRIX 'long double' crashed GDB
5255 When examining a long double variable, GDB would get a segmentation
5256 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5257 IRIX long double values).
5261 A bug in the VAX stack code was causing problems with the "next"
5262 command. This problem has been fixed.
5264 *** Changes in GDB 6.2:
5266 * Fix for ``many threads''
5268 On GNU/Linux systems that use the NPTL threads library, a program
5269 rapidly creating and deleting threads would confuse GDB leading to the
5272 ptrace: No such process.
5273 thread_db_get_info: cannot get thread info: generic error
5275 This problem has been fixed.
5277 * "-async" and "-noasync" options removed.
5279 Support for the broken "-noasync" option has been removed (it caused
5282 * New ``start'' command.
5284 This command runs the program until the begining of the main procedure.
5286 * New BSD Kernel Data Access Library (libkvm) interface
5288 Using ``target kvm'' it is now possible to debug kernel core dumps and
5289 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5290 platforms. Currently supported (native-only) configurations are:
5292 FreeBSD/amd64 x86_64-*-freebsd*
5293 FreeBSD/i386 i?86-*-freebsd*
5294 NetBSD/i386 i?86-*-netbsd*
5295 NetBSD/m68k m68*-*-netbsd*
5296 NetBSD/sparc sparc-*-netbsd*
5297 OpenBSD/amd64 x86_64-*-openbsd*
5298 OpenBSD/i386 i?86-*-openbsd*
5299 OpenBSD/m68k m68*-openbsd*
5300 OpenBSD/sparc sparc-*-openbsd*
5302 * Signal trampoline code overhauled
5304 Many generic problems with GDB's signal handling code have been fixed.
5305 These include: backtraces through non-contiguous stacks; recognition
5306 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5307 call; backtrace through a signal trampoline; step into and out of
5308 signal handlers; and single-stepping in the signal trampoline.
5310 Please note that kernel bugs are a limiting factor here. These
5311 features have been shown to work on an s390 GNU/Linux system that
5312 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5314 * Cygwin support for DWARF 2 added.
5316 * New native configurations
5318 GNU/Linux/hppa hppa*-*-linux*
5319 OpenBSD/hppa hppa*-*-openbsd*
5320 OpenBSD/m68k m68*-*-openbsd*
5321 OpenBSD/m88k m88*-*-openbsd*
5322 OpenBSD/powerpc powerpc-*-openbsd*
5323 NetBSD/vax vax-*-netbsd*
5324 OpenBSD/vax vax-*-openbsd*
5326 * END-OF-LIFE frame compatibility module
5328 GDB's internal frame infrastructure has been completely rewritten.
5329 The new infrastructure making it possible to support key new features
5330 including DWARF 2 Call Frame Information. To aid in the task of
5331 migrating old configurations to this new infrastructure, a
5332 compatibility module, that allowed old configurations to continue to
5333 work, was also included.
5335 GDB 6.2 will be the last release to include this frame compatibility
5336 module. This change directly impacts the following configurations:
5346 Unless there is activity to revive these configurations, they will be
5347 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5349 * REMOVED configurations and files
5351 Sun 3, running SunOS 3 m68*-*-sunos3*
5352 Sun 3, running SunOS 4 m68*-*-sunos4*
5353 Sun 2, running SunOS 3 m68000-*-sunos3*
5354 Sun 2, running SunOS 4 m68000-*-sunos4*
5355 Motorola 680x0 running LynxOS m68*-*-lynxos*
5356 AT&T 3b1/Unix pc m68*-att-*
5357 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5358 decstation mips-dec-* mips-little-*
5359 riscos mips-*-riscos* mips-*-sysv*
5360 sonymips mips-sony-*
5361 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5363 *** Changes in GDB 6.1.1:
5365 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5367 The TUI (Text-mode User Interface) is now built as part of a default
5368 GDB configuration. It is enabled by either selecting the TUI with the
5369 command line option "-i=tui" or by running the separate "gdbtui"
5370 program. For more information on the TUI, see the manual "Debugging
5373 * Pending breakpoint support (also included in GDB 6.1)
5375 Support has been added to allow you to specify breakpoints in shared
5376 libraries that have not yet been loaded. If a breakpoint location
5377 cannot be found, and the "breakpoint pending" option is set to auto,
5378 GDB queries you if you wish to make the breakpoint pending on a future
5379 shared-library load. If and when GDB resolves the breakpoint symbol,
5380 the pending breakpoint is removed as one or more regular breakpoints
5383 Pending breakpoints are very useful for GCJ Java debugging.
5385 * Fixed ISO-C build problems
5387 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5388 non ISO-C code that stopped them being built using a more strict ISO-C
5389 compiler (e.g., IBM's C compiler).
5391 * Fixed build problem on IRIX 5
5393 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5394 wasn't able to compile compile on an IRIX 5 system.
5396 * Added execute permission to gdb/gdbserver/configure
5398 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5399 permission. This bug would cause configure to fail on a number of
5400 systems (Solaris, IRIX). Ref: server/519.
5402 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5404 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5405 has been updated to use constant array sizes.
5407 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5409 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5410 its generated DWARF Call Frame Info. This encoding was causing GDB to
5411 panic, that panic has been fixed. Ref: gdb/1628.
5413 * Fixed a problem when examining parameters in shared library code.
5415 When examining parameters in optimized shared library code generated
5416 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5417 not available''. GDB now correctly displays the variable's value.
5419 *** Changes in GDB 6.1:
5421 * Removed --with-mmalloc
5423 Support for the mmalloc memory manager has been removed, as it
5424 conflicted with the internal gdb byte cache.
5426 * Changes in AMD64 configurations
5428 The AMD64 target now includes the %cs and %ss registers. As a result
5429 the AMD64 remote protocol has changed; this affects the floating-point
5430 and SSE registers. If you rely on those registers for your debugging,
5431 you should upgrade gdbserver on the remote side.
5433 * Revised SPARC target
5435 The SPARC target has been completely revised, incorporating the
5436 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5437 support for LynxOS and SunOS 4 has been dropped. Calling functions
5438 from within GDB on operating systems with a non-executable stack
5439 (Solaris, OpenBSD) now works.
5443 GDB has a new C++ demangler which does a better job on the mangled
5444 names generated by current versions of g++. It also runs faster, so
5445 with this and other changes gdb should now start faster on large C++
5448 * DWARF 2 Location Expressions
5450 GDB support for location expressions has been extended to support function
5451 arguments and frame bases. Older versions of GDB could crash when they
5454 * C++ nested types and namespaces
5456 GDB's support for nested types and namespaces in C++ has been
5457 improved, especially if you use the DWARF 2 debugging format. (This
5458 is the default for recent versions of GCC on most platforms.)
5459 Specifically, if you have a class "Inner" defined within a class or
5460 namespace "Outer", then GDB realizes that the class's name is
5461 "Outer::Inner", not simply "Inner". This should greatly reduce the
5462 frequency of complaints about not finding RTTI symbols. In addition,
5463 if you are stopped at inside of a function defined within a namespace,
5464 GDB modifies its name lookup accordingly.
5466 * New native configurations
5468 NetBSD/amd64 x86_64-*-netbsd*
5469 OpenBSD/amd64 x86_64-*-openbsd*
5470 OpenBSD/alpha alpha*-*-openbsd*
5471 OpenBSD/sparc sparc-*-openbsd*
5472 OpenBSD/sparc64 sparc64-*-openbsd*
5474 * New debugging protocols
5476 M32R with SDI protocol m32r-*-elf*
5478 * "set prompt-escape-char" command deleted.
5480 The command "set prompt-escape-char" has been deleted. This command,
5481 and its very obscure effet on GDB's prompt, was never documented,
5482 tested, nor mentioned in the NEWS file.
5484 * OBSOLETE configurations and files
5486 Configurations that have been declared obsolete in this release have
5487 been commented out. Unless there is activity to revive these
5488 configurations, the next release of GDB will have their sources
5489 permanently REMOVED.
5491 Sun 3, running SunOS 3 m68*-*-sunos3*
5492 Sun 3, running SunOS 4 m68*-*-sunos4*
5493 Sun 2, running SunOS 3 m68000-*-sunos3*
5494 Sun 2, running SunOS 4 m68000-*-sunos4*
5495 Motorola 680x0 running LynxOS m68*-*-lynxos*
5496 AT&T 3b1/Unix pc m68*-att-*
5497 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5498 decstation mips-dec-* mips-little-*
5499 riscos mips-*-riscos* mips-*-sysv*
5500 sonymips mips-sony-*
5501 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5503 * REMOVED configurations and files
5505 SGI Irix-4.x mips-sgi-irix4 or iris4
5506 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5507 Z8000 simulator z8k-zilog-none or z8ksim
5508 Matsushita MN10200 w/simulator mn10200-*-*
5509 H8/500 simulator h8500-hitachi-hms or h8500hms
5510 HP/PA running BSD hppa*-*-bsd*
5511 HP/PA running OSF/1 hppa*-*-osf*
5512 HP/PA Pro target hppa*-*-pro*
5513 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5514 386BSD i[3456]86-*-bsd*
5515 Sequent family i[3456]86-sequent-sysv4*
5516 i[3456]86-sequent-sysv*
5517 i[3456]86-sequent-bsd*
5518 SPARC running LynxOS sparc-*-lynxos*
5519 SPARC running SunOS 4 sparc-*-sunos4*
5520 Tsqware Sparclet sparclet-*-*
5521 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5523 *** Changes in GDB 6.0:
5527 Support for debugging the Objective-C programming language has been
5528 integrated into GDB.
5530 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5532 DWARF 2's Call Frame Information makes available compiler generated
5533 information that more exactly describes the program's run-time stack.
5534 By using this information, GDB is able to provide more robust stack
5537 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5538 have been updated to use a new backtrace mechanism which includes
5539 DWARF 2 CFI support.
5543 GDB's remote protocol has been extended to include support for hosted
5544 file I/O (where the remote target uses GDB's file system). See GDB's
5545 remote protocol documentation for details.
5547 * All targets using the new architecture framework.
5549 All of GDB's targets have been updated to use the new internal
5550 architecture framework. The way is now open for future GDB releases
5551 to include cross-architecture native debugging support (i386 on amd64,
5554 * GNU/Linux's Thread Local Storage (TLS)
5556 GDB now includes support for for the GNU/Linux implementation of
5557 per-thread variables.
5559 * GNU/Linux's Native POSIX Thread Library (NPTL)
5561 GDB's thread code has been updated to work with either the new
5562 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5564 * Separate debug info.
5566 GDB, in conjunction with BINUTILS, now supports a mechanism for
5567 automatically loading debug information from a separate file. Instead
5568 of shipping full debug and non-debug versions of system libraries,
5569 system integrators can now instead ship just the stripped libraries
5570 and optional debug files.
5572 * DWARF 2 Location Expressions
5574 DWARF 2 Location Expressions allow the compiler to more completely
5575 describe the location of variables (even in optimized code) to the
5578 GDB now includes preliminary support for location expressions (support
5579 for DW_OP_piece is still missing).
5583 A number of long standing bugs that caused GDB to die while starting a
5584 Java application have been fixed. GDB's Java support is now
5585 considered "useable".
5587 * GNU/Linux support for fork, vfork, and exec.
5589 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5590 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5593 * GDB supports logging output to a file
5595 There are two new commands, "set logging" and "show logging", which can be
5596 used to capture GDB's output to a file.
5598 * The meaning of "detach" has changed for gdbserver
5600 The "detach" command will now resume the application, as documented. To
5601 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5604 * d10v, m68hc11 `regs' command deprecated
5606 The `info registers' command has been updated so that it displays the
5607 registers using a format identical to the old `regs' command.
5611 A new command, "maint set profile on/off", has been added. This command can
5612 be used to enable or disable profiling while running GDB, to profile a
5613 session or a set of commands. In addition there is a new configure switch,
5614 "--enable-profiling", which will cause GDB to be compiled with profiling
5615 data, for more informative profiling results.
5617 * Default MI syntax changed to "mi2".
5619 The default MI (machine interface) syntax, enabled by the command line
5620 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5621 "mi1", can be enabled by specifying the option "-i=mi1".
5623 Support for the original "mi0" syntax (included in GDB 5.0) has been
5626 Fix for gdb/192: removed extraneous space when displaying frame level.
5627 Fix for gdb/672: update changelist is now output in mi list format.
5628 Fix for gdb/702: a -var-assign that updates the value now shows up
5629 in a subsequent -var-update.
5631 * New native configurations.
5633 FreeBSD/amd64 x86_64-*-freebsd*
5635 * Multi-arched targets.
5637 HP/PA HPUX11 hppa*-*-hpux*
5638 Renesas M32R/D w/simulator m32r-*-elf*
5640 * OBSOLETE configurations and files
5642 Configurations that have been declared obsolete in this release have
5643 been commented out. Unless there is activity to revive these
5644 configurations, the next release of GDB will have their sources
5645 permanently REMOVED.
5647 Z8000 simulator z8k-zilog-none or z8ksim
5648 Matsushita MN10200 w/simulator mn10200-*-*
5649 H8/500 simulator h8500-hitachi-hms or h8500hms
5650 HP/PA running BSD hppa*-*-bsd*
5651 HP/PA running OSF/1 hppa*-*-osf*
5652 HP/PA Pro target hppa*-*-pro*
5653 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5654 Sequent family i[3456]86-sequent-sysv4*
5655 i[3456]86-sequent-sysv*
5656 i[3456]86-sequent-bsd*
5657 Tsqware Sparclet sparclet-*-*
5658 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5660 * REMOVED configurations and files
5663 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5664 IBM AIX PS/2 i[3456]86-*-aix
5665 i386 running Mach 3.0 i[3456]86-*-mach3*
5666 i386 running Mach i[3456]86-*-mach*
5667 i386 running OSF/1 i[3456]86-*osf1mk*
5668 HP/Apollo 68k Family m68*-apollo*-sysv*,
5670 m68*-hp-bsd*, m68*-hp-hpux*
5671 Argonaut Risc Chip (ARC) arc-*-*
5672 Mitsubishi D30V d30v-*-*
5673 Fujitsu FR30 fr30-*-elf*
5674 OS/9000 i[34]86-*-os9k
5675 I960 with MON960 i960-*-coff
5677 * MIPS $fp behavior changed
5679 The convenience variable $fp, for the MIPS, now consistently returns
5680 the address of the current frame's base. Previously, depending on the
5681 context, $fp could refer to either $sp or the current frame's base
5682 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5683 The GNU Source-Level Debugger''.
5685 *** Changes in GDB 5.3:
5687 * GNU/Linux shared library multi-threaded performance improved.
5689 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5690 `/proc', in preference to `ptrace' for memory reads. This may result
5691 in an improvement in the start-up time of multi-threaded, shared
5692 library applications when run under GDB. One GDB user writes: ``loads
5693 shared libs like mad''.
5695 * ``gdbserver'' now supports multi-threaded applications on some targets
5697 Support for debugging multi-threaded applications which use
5698 the GNU/Linux LinuxThreads package has been added for
5699 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5700 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5702 * GDB now supports C/C++ preprocessor macros.
5704 GDB now expands preprocessor macro invocations in C/C++ expressions,
5705 and provides various commands for showing macro definitions and how
5708 The new command `macro expand EXPRESSION' expands any macro
5709 invocations in expression, and shows the result.
5711 The new command `show macro MACRO-NAME' shows the definition of the
5712 macro named MACRO-NAME, and where it was defined.
5714 Most compilers don't include information about macros in the debugging
5715 information by default. In GCC 3.1, for example, you need to compile
5716 your program with the options `-gdwarf-2 -g3'. If the macro
5717 information is present in the executable, GDB will read it.
5719 * Multi-arched targets.
5721 DEC Alpha (partial) alpha*-*-*
5722 DEC VAX (partial) vax-*-*
5724 National Semiconductor NS32000 (partial) ns32k-*-*
5725 Motorola 68000 (partial) m68k-*-*
5726 Motorola MCORE mcore-*-*
5730 Fujitsu FRV architecture added by Red Hat frv*-*-*
5733 * New native configurations
5735 Alpha NetBSD alpha*-*-netbsd*
5736 SH NetBSD sh*-*-netbsdelf*
5737 MIPS NetBSD mips*-*-netbsd*
5738 UltraSPARC NetBSD sparc64-*-netbsd*
5740 * OBSOLETE configurations and files
5742 Configurations that have been declared obsolete in this release have
5743 been commented out. Unless there is activity to revive these
5744 configurations, the next release of GDB will have their sources
5745 permanently REMOVED.
5747 Mitsubishi D30V d30v-*-*
5748 OS/9000 i[34]86-*-os9k
5749 IBM AIX PS/2 i[3456]86-*-aix
5750 Fujitsu FR30 fr30-*-elf*
5751 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5752 Argonaut Risc Chip (ARC) arc-*-*
5753 i386 running Mach 3.0 i[3456]86-*-mach3*
5754 i386 running Mach i[3456]86-*-mach*
5755 i386 running OSF/1 i[3456]86-*osf1mk*
5756 HP/Apollo 68k Family m68*-apollo*-sysv*,
5758 m68*-hp-bsd*, m68*-hp-hpux*
5759 I960 with MON960 i960-*-coff
5761 * OBSOLETE languages
5763 CHILL, a Pascal like language used by telecommunications companies.
5765 * REMOVED configurations and files
5767 AMD 29k family via UDI a29k-amd-udi, udi29k
5768 A29K VxWorks a29k-*-vxworks
5769 AMD 29000 embedded, using EBMON a29k-none-none
5770 AMD 29000 embedded with COFF a29k-none-coff
5771 AMD 29000 embedded with a.out a29k-none-aout
5773 testsuite/gdb.hp/gdb.threads-hp/ directory
5775 * New command "set max-user-call-depth <nnn>"
5777 This command allows the user to limit the call depth of user-defined
5778 commands. The default is 1024.
5780 * Changes in FreeBSD/i386 native debugging.
5782 Support for the "generate-core-file" has been added.
5784 * New commands "dump", "append", and "restore".
5786 These commands allow data to be copied from target memory
5787 to a bfd-format or binary file (dump and append), and back
5788 from a file into memory (restore).
5790 * Improved "next/step" support on multi-processor Alpha Tru64.
5792 The previous single-step mechanism could cause unpredictable problems,
5793 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5794 of a software single-step mechanism prevents this.
5796 *** Changes in GDB 5.2.1:
5804 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5805 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5806 Fix, by Joel Brobecker imported from mainline.
5808 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5809 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5810 Fix, by Fred Fish, imported from mainline.
5812 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5813 Surprisingly enough, it works now.
5814 By Michal Ludvig, imported from mainline.
5816 i386 hardware watchpoint support:
5817 avoid misses on second run for some targets.
5818 By Pierre Muller, imported from mainline.
5820 *** Changes in GDB 5.2:
5822 * New command "set trust-readonly-sections on[off]".
5824 This command is a hint that tells gdb that read-only sections
5825 really are read-only (ie. that their contents will not change).
5826 In this mode, gdb will go to the object file rather than the
5827 target to read memory from read-only sections (such as ".text").
5828 This can be a significant performance improvement on some
5829 (notably embedded) targets.
5831 * New command "generate-core-file" (or "gcore").
5833 This new gdb command allows the user to drop a core file of the child
5834 process state at any time. So far it's been implemented only for
5835 GNU/Linux and Solaris, but should be relatively easily ported to other
5836 hosts. Argument is core file name (defaults to core.<pid>).
5838 * New command line option
5840 GDB now accepts --pid or -p followed by a process id.
5842 * Change in command line behavior -- corefiles vs. process ids.
5844 There is a subtle behavior in the way in which GDB handles
5845 command line arguments. The first non-flag argument is always
5846 a program to debug, but the second non-flag argument may either
5847 be a corefile or a process id. Previously, GDB would attempt to
5848 open the second argument as a corefile, and if that failed, would
5849 issue a superfluous error message and then attempt to attach it as
5850 a process. Now, if the second argument begins with a non-digit,
5851 it will be treated as a corefile. If it begins with a digit,
5852 GDB will attempt to attach it as a process, and if no such process
5853 is found, will then attempt to open it as a corefile.
5855 * Changes in ARM configurations.
5857 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5858 configuration is fully multi-arch.
5860 * New native configurations
5862 ARM NetBSD arm*-*-netbsd*
5863 x86 OpenBSD i[3456]86-*-openbsd*
5864 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5865 Sparc64 running FreeBSD sparc64-*-freebsd*
5869 Sanyo XStormy16 xstormy16-elf
5871 * OBSOLETE configurations and files
5873 Configurations that have been declared obsolete in this release have
5874 been commented out. Unless there is activity to revive these
5875 configurations, the next release of GDB will have their sources
5876 permanently REMOVED.
5878 AMD 29k family via UDI a29k-amd-udi, udi29k
5879 A29K VxWorks a29k-*-vxworks
5880 AMD 29000 embedded, using EBMON a29k-none-none
5881 AMD 29000 embedded with COFF a29k-none-coff
5882 AMD 29000 embedded with a.out a29k-none-aout
5884 testsuite/gdb.hp/gdb.threads-hp/ directory
5886 * REMOVED configurations and files
5888 TI TMS320C80 tic80-*-*
5890 PowerPC Solaris powerpcle-*-solaris*
5891 PowerPC Windows NT powerpcle-*-cygwin32
5892 PowerPC Netware powerpc-*-netware*
5893 Harris/CXUX m88k m88*-harris-cxux*
5894 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5895 ns32k-utek-sysv* ns32k-utek-*
5896 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5897 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5898 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5899 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5900 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5902 * Changes to command line processing
5904 The new `--args' feature can be used to specify command-line arguments
5905 for the inferior from gdb's command line.
5907 * Changes to key bindings
5909 There is a new `operate-and-get-next' function bound to `C-o'.
5911 *** Changes in GDB 5.1.1
5913 Fix compile problem on DJGPP.
5915 Fix a problem with floating-point registers on the i386 being
5918 Fix to stop GDB crashing on .debug_str debug info.
5920 Numerous documentation fixes.
5922 Numerous testsuite fixes.
5924 *** Changes in GDB 5.1:
5926 * New native configurations
5928 Alpha FreeBSD alpha*-*-freebsd*
5929 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5930 MIPS GNU/Linux mips*-*-linux*
5931 MIPS SGI Irix 6.x mips*-sgi-irix6*
5932 ia64 AIX ia64-*-aix*
5933 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5937 Motorola 68HC11 and 68HC12 m68hc11-elf
5939 UltraSparc running GNU/Linux sparc64-*-linux*
5941 * OBSOLETE configurations and files
5943 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5944 Harris/CXUX m88k m88*-harris-cxux*
5945 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5946 ns32k-utek-sysv* ns32k-utek-*
5947 TI TMS320C80 tic80-*-*
5949 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5950 PowerPC Solaris powerpcle-*-solaris*
5951 PowerPC Windows NT powerpcle-*-cygwin32
5952 PowerPC Netware powerpc-*-netware*
5953 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5954 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5955 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5956 Apple Macintosh (MPW) host N/A
5958 stuff.c (Program to stuff files into a specially prepared space in kdb)
5959 kdb-start.c (Main loop for the standalone kernel debugger)
5961 Configurations that have been declared obsolete in this release have
5962 been commented out. Unless there is activity to revive these
5963 configurations, the next release of GDB will have their sources
5964 permanently REMOVED.
5966 * REMOVED configurations and files
5968 Altos 3068 m68*-altos-*
5969 Convex c1-*-*, c2-*-*
5971 ARM RISCix arm-*-* (as host)
5975 * GDB has been converted to ISO C.
5977 GDB's source code has been converted to ISO C. In particular, the
5978 sources are fully protoized, and rely on standard headers being
5983 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5985 * The MI enabled by default.
5987 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5988 revised and enabled by default. Packages which use GDB as a debugging
5989 engine behind a UI or another front end are encouraged to switch to
5990 using the GDB/MI interface, instead of the old annotations interface
5991 which is now deprecated.
5993 * Support for debugging Pascal programs.
5995 GDB now includes support for debugging Pascal programs. The following
5996 main features are supported:
5998 - Pascal-specific data types such as sets;
6000 - automatic recognition of Pascal sources based on file-name
6003 - Pascal-style display of data types, variables, and functions;
6005 - a Pascal expression parser.
6007 However, some important features are not yet supported.
6009 - Pascal string operations are not supported at all;
6011 - there are some problems with boolean types;
6013 - Pascal type hexadecimal constants are not supported
6014 because they conflict with the internal variables format;
6016 - support for Pascal objects and classes is not full yet;
6018 - unlike Pascal, GDB is case-sensitive for symbol names.
6020 * Changes in completion.
6022 Commands such as `shell', `run' and `set args', which pass arguments
6023 to inferior programs, now complete on file names, similar to what
6024 users expect at the shell prompt.
6026 Commands which accept locations, such as `disassemble', `print',
6027 `breakpoint', `until', etc. now complete on filenames as well as
6028 program symbols. Thus, if you type "break foob TAB", and the source
6029 files linked into the programs include `foobar.c', that file name will
6030 be one of the candidates for completion. However, file names are not
6031 considered for completion after you typed a colon that delimits a file
6032 name from a name of a function in that file, as in "break foo.c:bar".
6034 `set demangle-style' completes on available demangling styles.
6036 * New platform-independent commands:
6038 It is now possible to define a post-hook for a command as well as a
6039 hook that runs before the command. For more details, see the
6040 documentation of `hookpost' in the GDB manual.
6042 * Changes in GNU/Linux native debugging.
6044 Support for debugging multi-threaded programs has been completely
6045 revised for all platforms except m68k and sparc. You can now debug as
6046 many threads as your system allows you to have.
6048 Attach/detach is supported for multi-threaded programs.
6050 Support for SSE registers was added for x86. This doesn't work for
6051 multi-threaded programs though.
6053 * Changes in MIPS configurations.
6055 Multi-arch support is enabled for all MIPS configurations.
6057 GDB can now be built as native debugger on SGI Irix 6.x systems for
6058 debugging n32 executables. (Debugging 64-bit executables is not yet
6061 * Unified support for hardware watchpoints in all x86 configurations.
6063 Most (if not all) native x86 configurations support hardware-assisted
6064 breakpoints and watchpoints in a unified manner. This support
6065 implements debug register sharing between watchpoints, which allows to
6066 put a virtually infinite number of watchpoints on the same address,
6067 and also supports watching regions up to 16 bytes with several debug
6070 The new maintenance command `maintenance show-debug-regs' toggles
6071 debugging print-outs in functions that insert, remove, and test
6072 watchpoints and hardware breakpoints.
6074 * Changes in the DJGPP native configuration.
6076 New command ``info dos sysinfo'' displays assorted information about
6077 the CPU, OS, memory, and DPMI server.
6079 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6080 display information about segment descriptors stored in GDT, LDT, and
6083 New commands ``info dos pde'' and ``info dos pte'' display entries
6084 from Page Directory and Page Tables (for now works with CWSDPMI only).
6085 New command ``info dos address-pte'' displays the Page Table entry for
6086 a given linear address.
6088 GDB can now pass command lines longer than 126 characters to the
6089 program being debugged (requires an update to the libdbg.a library
6090 which is part of the DJGPP development kit).
6092 DWARF2 debug info is now supported.
6094 It is now possible to `step' and `next' through calls to `longjmp'.
6096 * Changes in documentation.
6098 All GDB documentation was converted to GFDL, the GNU Free
6099 Documentation License.
6101 Tracepoints-related commands are now fully documented in the GDB
6104 TUI, the Text-mode User Interface, is now documented in the manual.
6106 Tracepoints-related commands are now fully documented in the GDB
6109 The "GDB Internals" manual now has an index. It also includes
6110 documentation of `ui_out' functions, GDB coding standards, x86
6111 hardware watchpoints, and memory region attributes.
6113 * GDB's version number moved to ``version.in''
6115 The Makefile variable VERSION has been replaced by the file
6116 ``version.in''. People creating GDB distributions should update the
6117 contents of this file.
6121 GUD support is now a standard part of the EMACS distribution.
6123 *** Changes in GDB 5.0:
6125 * Improved support for debugging FP programs on x86 targets
6127 Unified and much-improved support for debugging floating-point
6128 programs on all x86 targets. In particular, ``info float'' now
6129 displays the FP registers in the same format on all x86 targets, with
6130 greater level of detail.
6132 * Improvements and bugfixes in hardware-assisted watchpoints
6134 It is now possible to watch array elements, struct members, and
6135 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6136 on x86 targets no longer erroneously trigger when the address is
6139 * Improvements in the native DJGPP version of GDB
6141 The distribution now includes all the scripts and auxiliary files
6142 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6143 machines ``out of the box''.
6145 The DJGPP version can now debug programs that use signals. It is
6146 possible to catch signals that happened in the debuggee, deliver
6147 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6148 would kill the program being debugged.) Programs that hook hardware
6149 interrupts (keyboard, timer, etc.) can also be debugged.
6151 It is now possible to debug DJGPP programs that redirect their
6152 standard handles or switch them to raw (as opposed to cooked) mode, or
6153 even close them. The command ``run < foo > bar'' works as expected,
6154 and ``info terminal'' reports useful information about the debuggee's
6155 terminal, including raw/cooked mode, redirection, etc.
6157 The DJGPP version now uses termios functions for console I/O, which
6158 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6161 DOS-style file names with drive letters are now fully supported by
6164 It is now possible to debug DJGPP programs that switch their working
6165 directory. It is also possible to rerun the debuggee any number of
6166 times without restarting GDB; thus, you can use the same setup,
6167 breakpoints, etc. for many debugging sessions.
6169 * New native configurations
6171 ARM GNU/Linux arm*-*-linux*
6172 PowerPC GNU/Linux powerpc-*-linux*
6176 Motorola MCore mcore-*-*
6177 x86 VxWorks i[3456]86-*-vxworks*
6178 PowerPC VxWorks powerpc-*-vxworks*
6179 TI TMS320C80 tic80-*-*
6181 * OBSOLETE configurations
6183 Altos 3068 m68*-altos-*
6184 Convex c1-*-*, c2-*-*
6186 ARM RISCix arm-*-* (as host)
6189 Configurations that have been declared obsolete will be commented out,
6190 but the code will be left in place. If there is no activity to revive
6191 these configurations before the next release of GDB, the sources will
6192 be permanently REMOVED.
6194 * Gould support removed
6196 Support for the Gould PowerNode and NP1 has been removed.
6198 * New features for SVR4
6200 On SVR4 native platforms (such as Solaris), if you attach to a process
6201 without first loading a symbol file, GDB will now attempt to locate and
6202 load symbols from the running process's executable file.
6204 * Many C++ enhancements
6206 C++ support has been greatly improved. Overload resolution now works properly
6207 in almost all cases. RTTI support is on the way.
6209 * Remote targets can connect to a sub-program
6211 A popen(3) style serial-device has been added. This device starts a
6212 sub-process (such as a stand-alone simulator) and then communicates
6213 with that. The sub-program to run is specified using the syntax
6214 ``|<program> <args>'' vis:
6216 (gdb) set remotedebug 1
6217 (gdb) target extended-remote |mn10300-elf-sim program-args
6219 * MIPS 64 remote protocol
6221 A long standing bug in the mips64 remote protocol where by GDB
6222 expected certain 32 bit registers (ex SR) to be transfered as 32
6223 instead of 64 bits has been fixed.
6225 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6226 added to provide backward compatibility with older versions of GDB.
6228 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6230 The command ``set remotebinarydownload'' command has been replaced by
6231 ``set remote X-packet''. Other commands in ``set remote'' family
6232 include ``set remote P-packet''.
6234 * Breakpoint commands accept ranges.
6236 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6237 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6238 ``tracepoint passcount'' also accepts a range of tracepoints.
6240 * ``apropos'' command added.
6242 The ``apropos'' command searches through command names and
6243 documentation strings, printing out matches, making it much easier to
6244 try to find a command that does what you are looking for.
6248 A new machine oriented interface (MI) has been added to GDB. This
6249 interface is designed for debug environments running GDB as a separate
6250 process. This is part of the long term libGDB project. See the
6251 "GDB/MI" chapter of the GDB manual for further information. It can be
6252 enabled by configuring with:
6254 .../configure --enable-gdbmi
6256 *** Changes in GDB-4.18:
6258 * New native configurations
6260 HP-UX 10.20 hppa*-*-hpux10.20
6261 HP-UX 11.x hppa*-*-hpux11.0*
6262 M68K GNU/Linux m68*-*-linux*
6266 Fujitsu FR30 fr30-*-elf*
6267 Intel StrongARM strongarm-*-*
6268 Mitsubishi D30V d30v-*-*
6270 * OBSOLETE configurations
6272 Gould PowerNode, NP1 np1-*-*, pn-*-*
6274 Configurations that have been declared obsolete will be commented out,
6275 but the code will be left in place. If there is no activity to revive
6276 these configurations before the next release of GDB, the sources will
6277 be permanently REMOVED.
6281 As a compatibility experiment, GDB's source files buildsym.h and
6282 buildsym.c have been converted to pure standard C, no longer
6283 containing any K&R compatibility code. We believe that all systems in
6284 use today either come with a standard C compiler, or have a GCC port
6285 available. If this is not true, please report the affected
6286 configuration to bug-gdb@gnu.org immediately. See the README file for
6287 information about getting a standard C compiler if you don't have one
6292 GDB now uses readline 2.2.
6294 * set extension-language
6296 You can now control the mapping between filename extensions and source
6297 languages by using the `set extension-language' command. For instance,
6298 you can ask GDB to treat .c files as C++ by saying
6299 set extension-language .c c++
6300 The command `info extensions' lists all of the recognized extensions
6301 and their associated languages.
6303 * Setting processor type for PowerPC and RS/6000
6305 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6306 you can use the `set processor' command to specify what variant of the
6307 PowerPC family you are debugging. The command
6311 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6312 following PowerPC and RS6000 variants:
6314 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6315 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6317 403GC IBM PowerPC 403GC
6318 505 Motorola PowerPC 505
6319 860 Motorola PowerPC 860 or 850
6320 601 Motorola PowerPC 601
6321 602 Motorola PowerPC 602
6322 603 Motorola/IBM PowerPC 603 or 603e
6323 604 Motorola PowerPC 604 or 604e
6324 750 Motorola/IBM PowerPC 750 or 750
6326 At the moment, this command just tells GDB what to name the
6327 special-purpose processor registers. Since almost all the affected
6328 registers are inaccessible to user-level programs, this command is
6329 only useful for remote debugging in its present form.
6333 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6334 more extensive support for HP-UX. Added features include shared
6335 library support, kernel threads and hardware watchpoints for 11.00,
6336 support for HP's ANSI C and C++ compilers, and a compatibility mode
6337 for xdb and dbx commands.
6341 HP's donation includes the new concept of catchpoints, which is a
6342 generalization of the old catch command. On HP-UX, it is now possible
6343 to catch exec, fork, and vfork, as well as library loading.
6345 This means that the existing catch command has changed; its first
6346 argument now specifies the type of catch to be set up. See the
6347 output of "help catch" for a list of catchpoint types.
6349 * Debugging across forks
6351 On HP-UX, you can choose which process to debug when a fork() happens
6356 HP has donated a curses-based terminal user interface (TUI). To get
6357 it, build with --enable-tui. Although this can be enabled for any
6358 configuration, at present it only works for native HP debugging.
6360 * GDB remote protocol additions
6362 A new protocol packet 'X' that writes binary data is now available.
6363 Default behavior is to try 'X', then drop back to 'M' if the stub
6364 fails to respond. The settable variable `remotebinarydownload'
6365 allows explicit control over the use of 'X'.
6367 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6368 full 64-bit address. The command
6370 set remoteaddresssize 32
6372 can be used to revert to the old behaviour. For existing remote stubs
6373 the change should not be noticed, as the additional address information
6376 In order to assist in debugging stubs, you may use the maintenance
6377 command `packet' to send any text string to the stub. For instance,
6379 maint packet heythere
6381 sends the packet "$heythere#<checksum>". Note that it is very easy to
6382 disrupt a debugging session by sending the wrong packet at the wrong
6385 The compare-sections command allows you to compare section data on the
6386 target to what is in the executable file without uploading or
6387 downloading, by comparing CRC checksums.
6389 * Tracing can collect general expressions
6391 You may now collect general expressions at tracepoints. This requires
6392 further additions to the target-side stub; see tracepoint.c and
6393 doc/agentexpr.texi for further details.
6395 * mask-address variable for Mips
6397 For Mips targets, you may control the zeroing of the upper 32 bits of
6398 a 64-bit address by entering `set mask-address on'. This is mainly
6399 of interest to users of embedded R4xxx and R5xxx processors.
6401 * Higher serial baud rates
6403 GDB's serial code now allows you to specify baud rates 57600, 115200,
6404 230400, and 460800 baud. (Note that your host system may not be able
6405 to achieve all of these rates.)
6409 The i960 configuration now includes an initial implementation of a
6410 builtin simulator, contributed by Jim Wilson.
6413 *** Changes in GDB-4.17:
6415 * New native configurations
6417 Alpha GNU/Linux alpha*-*-linux*
6418 Unixware 2.x i[3456]86-unixware2*
6419 Irix 6.x mips*-sgi-irix6*
6420 PowerPC GNU/Linux powerpc-*-linux*
6421 PowerPC Solaris powerpcle-*-solaris*
6422 Sparc GNU/Linux sparc-*-linux*
6423 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6427 Argonaut Risc Chip (ARC) arc-*-*
6428 Hitachi H8/300S h8300*-*-*
6429 Matsushita MN10200 w/simulator mn10200-*-*
6430 Matsushita MN10300 w/simulator mn10300-*-*
6431 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6432 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6433 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6434 Mitsubishi D10V w/simulator d10v-*-*
6435 Mitsubishi M32R/D w/simulator m32r-*-elf*
6436 Tsqware Sparclet sparclet-*-*
6437 NEC V850 w/simulator v850-*-*
6439 * New debugging protocols
6441 ARM with RDI protocol arm*-*-*
6442 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6443 DDB and LSI variants of PMON protocol mips*-*-*
6444 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6445 PowerPC with SDS protocol powerpc{,le}-*-eabi
6446 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6450 All configurations can now understand and use the DWARF 2 debugging
6451 format. The choice is automatic, if the symbol file contains DWARF 2
6456 GDB now includes basic Java language support. This support is
6457 only useful with Java compilers that produce native machine code.
6459 * solib-absolute-prefix and solib-search-path
6461 For SunOS and SVR4 shared libraries, you may now set the prefix for
6462 loading absolute shared library symbol files, and the search path for
6463 locating non-absolute shared library symbol files.
6465 * Live range splitting
6467 GDB can now effectively debug code for which GCC has performed live
6468 range splitting as part of its optimization. See gdb/doc/LRS for
6469 more details on the expected format of the stabs information.
6473 GDB's support for the GNU Hurd, including thread debugging, has been
6474 updated to work with current versions of the Hurd.
6478 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6479 instruction set. ARM GDB automatically detects when Thumb
6480 instructions are in use, and adjusts disassembly and backtracing
6485 GDB's MIPS target configurations now handle the MIP16 16-bit
6490 GDB now includes support for overlays; if an executable has been
6491 linked such that multiple sections are based at the same address, GDB
6492 will decide which section to use for symbolic info. You can choose to
6493 control the decision manually, using overlay commands, or implement
6494 additional target-side support and use "overlay load-target" to bring
6495 in the overlay mapping. Do "help overlay" for more detail.
6499 The command "info symbol <address>" displays information about
6500 the symbol at the specified address.
6504 The standard remote protocol now includes an extension that allows
6505 asynchronous collection and display of trace data. This requires
6506 extensive support in the target-side debugging stub. Tracing mode
6507 includes a new interaction mode in GDB and new commands: see the
6508 file tracepoint.c for more details.
6512 Configurations for embedded MIPS now include a simulator contributed
6513 by Cygnus Solutions. The simulator supports the instruction sets
6514 of most MIPS variants.
6518 Sparc configurations may now include the ERC32 simulator contributed
6519 by the European Space Agency. The simulator is not built into
6520 Sparc targets by default; configure with --enable-sim to include it.
6524 For target configurations that may include multiple variants of a
6525 basic architecture (such as MIPS and SH), you may now set the
6526 architecture explicitly. "set arch" sets, "info arch" lists
6527 the possible architectures.
6529 *** Changes in GDB-4.16:
6531 * New native configurations
6533 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6534 M68K NetBSD m68k-*-netbsd*
6535 PowerPC AIX 4.x powerpc-*-aix*
6536 PowerPC MacOS powerpc-*-macos*
6537 PowerPC Windows NT powerpcle-*-cygwin32
6538 RS/6000 AIX 4.x rs6000-*-aix4*
6542 ARM with RDP protocol arm-*-*
6543 I960 with MON960 i960-*-coff
6544 MIPS VxWorks mips*-*-vxworks*
6545 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6546 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6548 Matra Sparclet sparclet-*-*
6552 The powerpc-eabi configuration now includes the PSIM simulator,
6553 contributed by Andrew Cagney, with assistance from Mike Meissner.
6554 PSIM is a very elaborate model of the PowerPC, including not only
6555 basic instruction set execution, but also details of execution unit
6556 performance and I/O hardware. See sim/ppc/README for more details.
6560 GDB now works with Solaris 2.5.
6562 * Windows 95/NT native
6564 GDB will now work as a native debugger on Windows 95 and Windows NT.
6565 To build it from source, you must use the "gnu-win32" environment,
6566 which uses a DLL to emulate enough of Unix to run the GNU tools.
6567 Further information, binaries, and sources are available at
6568 ftp.cygnus.com, under pub/gnu-win32.
6570 * dont-repeat command
6572 If a user-defined command includes the command `dont-repeat', then the
6573 command will not be repeated if the user just types return. This is
6574 useful if the command is time-consuming to run, so that accidental
6575 extra keystrokes don't run the same command many times.
6577 * Send break instead of ^C
6579 The standard remote protocol now includes an option to send a break
6580 rather than a ^C to the target in order to interrupt it. By default,
6581 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6583 * Remote protocol timeout
6585 The standard remote protocol includes a new variable `remotetimeout'
6586 that allows you to set the number of seconds before GDB gives up trying
6587 to read from the target. The default value is 2.
6589 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6591 By default GDB will automatically keep track of objects as they are
6592 loaded and unloaded by the dynamic linker. By using the command `set
6593 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6594 when shared library events occur, thus allowing you to set breakpoints
6595 in shared libraries which are explicitly loaded by the inferior.
6597 Note this feature does not work on hpux8. On hpux9 you must link
6598 /usr/lib/end.o into your program. This feature should work
6599 automatically on hpux10.
6601 * Irix 5.x hardware watchpoint support
6603 Irix 5 configurations now support the use of hardware watchpoints.
6605 * Mips protocol "SYN garbage limit"
6607 When debugging a Mips target using the `target mips' protocol, you
6608 may set the number of characters that GDB will ignore by setting
6609 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6610 every character. The default value is 1050.
6612 * Recording and replaying remote debug sessions
6614 If you set `remotelogfile' to the name of a file, gdb will write to it
6615 a recording of a remote debug session. This recording may then be
6616 replayed back to gdb using "gdbreplay". See gdbserver/README for
6617 details. This is useful when you have a problem with GDB while doing
6618 remote debugging; you can make a recording of the session and send it
6619 to someone else, who can then recreate the problem.
6621 * Speedups for remote debugging
6623 GDB includes speedups for downloading and stepping MIPS systems using
6624 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6625 and more efficient S-record downloading.
6627 * Memory use reductions and statistics collection
6629 GDB now uses less memory and reports statistics about memory usage.
6630 Try the `maint print statistics' command, for example.
6632 *** Changes in GDB-4.15:
6634 * Psymtabs for XCOFF
6636 The symbol reader for AIX GDB now uses partial symbol tables. This
6637 can greatly improve startup time, especially for large executables.
6639 * Remote targets use caching
6641 Remote targets now use a data cache to speed up communication with the
6642 remote side. The data cache could lead to incorrect results because
6643 it doesn't know about volatile variables, thus making it impossible to
6644 debug targets which use memory mapped I/O devices. `set remotecache
6645 off' turns the data cache off.
6647 * Remote targets may have threads
6649 The standard remote protocol now includes support for multiple threads
6650 in the target system, using new protocol commands 'H' and 'T'. See
6651 gdb/remote.c for details.
6655 If GDB is configured with `--enable-netrom', then it will include
6656 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6657 acts as though it is a bank of ROM on the target board, but you can
6658 write into it over the network. GDB's support consists only of
6659 support for fast loading into the emulated ROM; to debug, you must use
6660 another protocol, such as standard remote protocol. The usual
6661 sequence is something like
6663 target nrom <netrom-hostname>
6665 target remote <netrom-hostname>:1235
6669 GDB now includes support for the Apple Macintosh, as a host only. It
6670 may be run as either an MPW tool or as a standalone application, and
6671 it can debug through the serial port. All the usual GDB commands are
6672 available, but to the target command, you must supply "serial" as the
6673 device type instead of "/dev/ttyXX". See mpw-README in the main
6674 directory for more information on how to build. The MPW configuration
6675 scripts */mpw-config.in support only a few targets, and only the
6676 mips-idt-ecoff target has been tested.
6680 GDB configuration now uses autoconf. This is not user-visible,
6681 but does simplify configuration and building.
6685 GDB now supports hpux10.
6687 *** Changes in GDB-4.14:
6689 * New native configurations
6691 x86 FreeBSD i[345]86-*-freebsd
6692 x86 NetBSD i[345]86-*-netbsd
6693 NS32k NetBSD ns32k-*-netbsd
6694 Sparc NetBSD sparc-*-netbsd
6698 A29K VxWorks a29k-*-vxworks
6699 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6700 CPU32 EST-300 emulator m68*-*-est*
6701 PowerPC ELF powerpc-*-elf
6704 * Alpha OSF/1 support for procfs
6706 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6707 possible to attach to running processes. As the mounting of the /proc
6708 filesystem is optional on the Alpha, GDB automatically determines
6709 the availability of /proc during startup. This can lead to problems
6710 if /proc is unmounted after GDB has been started.
6712 * Arguments to user-defined commands
6714 User commands may accept up to 10 arguments separated by whitespace.
6715 Arguments are accessed within the user command via $arg0..$arg9. A
6718 print $arg0 + $arg1 + $arg2
6720 To execute the command use:
6723 Defines the command "adder" which prints the sum of its three arguments.
6724 Note the arguments are text substitutions, so they may reference variables,
6725 use complex expressions, or even perform inferior function calls.
6727 * New `if' and `while' commands
6729 This makes it possible to write more sophisticated user-defined
6730 commands. Both commands take a single argument, which is the
6731 expression to evaluate, and must be followed by the commands to
6732 execute, one per line, if the expression is nonzero, the list being
6733 terminated by the word `end'. The `if' command list may include an
6734 `else' word, which causes the following commands to be executed only
6735 if the expression is zero.
6737 * Fortran source language mode
6739 GDB now includes partial support for Fortran 77. It will recognize
6740 Fortran programs and can evaluate a subset of Fortran expressions, but
6741 variables and functions may not be handled correctly. GDB will work
6742 with G77, but does not yet know much about symbols emitted by other
6745 * Better HPUX support
6747 Most debugging facilities now work on dynamic executables for HPPAs
6748 running hpux9 or later. You can attach to running dynamically linked
6749 processes, but by default the dynamic libraries will be read-only, so
6750 for instance you won't be able to put breakpoints in them. To change
6751 that behavior do the following before running the program:
6757 This will cause the libraries to be mapped private and read-write.
6758 To revert to the normal behavior, do this:
6764 You cannot set breakpoints or examine data in the library until after
6765 the library is loaded if the function/data symbols do not have
6768 GDB can now also read debug symbols produced by the HP C compiler on
6769 HPPAs (sorry, no C++, Fortran or 68k support).
6771 * Target byte order now dynamically selectable
6773 You can choose which byte order to use with a target system, via the
6774 commands "set endian big" and "set endian little", and you can see the
6775 current setting by using "show endian". You can also give the command
6776 "set endian auto", in which case GDB will use the byte order
6777 associated with the executable. Currently, only embedded MIPS
6778 configurations support dynamic selection of target byte order.
6780 * New DOS host serial code
6782 This version uses DPMI interrupts to handle buffered I/O, so you
6783 no longer need to run asynctsr when debugging boards connected to
6786 *** Changes in GDB-4.13:
6788 * New "complete" command
6790 This lists all the possible completions for the rest of the line, if it
6791 were to be given as a command itself. This is intended for use by emacs.
6793 * Trailing space optional in prompt
6795 "set prompt" no longer adds a space for you after the prompt you set. This
6796 allows you to set a prompt which ends in a space or one that does not.
6798 * Breakpoint hit counts
6800 "info break" now displays a count of the number of times the breakpoint
6801 has been hit. This is especially useful in conjunction with "ignore"; you
6802 can ignore a large number of breakpoint hits, look at the breakpoint info
6803 to see how many times the breakpoint was hit, then run again, ignoring one
6804 less than that number, and this will get you quickly to the last hit of
6807 * Ability to stop printing at NULL character
6809 "set print null-stop" will cause GDB to stop printing the characters of
6810 an array when the first NULL is encountered. This is useful when large
6811 arrays actually contain only short strings.
6813 * Shared library breakpoints
6815 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6816 breakpoints in shared libraries before the executable is run.
6818 * Hardware watchpoints
6820 There is a new hardware breakpoint for the watch command for sparclite
6821 targets. See gdb/sparclite/hw_breakpoint.note.
6823 Hardware watchpoints are also now supported under GNU/Linux.
6827 Annotations have been added. These are for use with graphical interfaces,
6828 and are still experimental. Currently only gdba.el uses these.
6830 * Improved Irix 5 support
6832 GDB now works properly with Irix 5.2.
6834 * Improved HPPA support
6836 GDB now works properly with the latest GCC and GAS.
6838 * New native configurations
6840 Sequent PTX4 i[34]86-sequent-ptx4
6841 HPPA running OSF/1 hppa*-*-osf*
6842 Atari TT running SVR4 m68*-*-sysv4*
6843 RS/6000 LynxOS rs6000-*-lynxos*
6847 OS/9000 i[34]86-*-os9k
6848 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6851 * Hitachi SH7000 and E7000-PC ICE support
6853 There is now support for communicating with the Hitachi E7000-PC ICE.
6854 This is available automatically when GDB is configured for the SH.
6858 As usual, a variety of small fixes and improvements, both generic
6859 and configuration-specific. See the ChangeLog for more detail.
6861 *** Changes in GDB-4.12:
6863 * Irix 5 is now supported
6867 GDB-4.12 on the HPPA has a number of changes which make it unable
6868 to debug the output from the currently released versions of GCC and
6869 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6870 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6871 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6874 *** Changes in GDB-4.11:
6876 * User visible changes:
6880 The "set remotedebug" option is now consistent between the mips remote
6881 target, remote targets using the gdb-specific protocol, UDI (AMD's
6882 debug protocol for the 29k) and the 88k bug monitor. It is now an
6883 integer specifying a debug level (normally 0 or 1, but 2 means more
6884 debugging info for the mips target).
6886 * DEC Alpha native support
6888 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6889 debug info, but GDB works fairly well with the DEC compiler and should
6890 work with a future GCC release. See the README file for a few
6891 Alpha-specific notes.
6893 * Preliminary thread implementation
6895 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6897 * LynxOS native and target support for 386
6899 This release has been hosted on LynxOS 2.2, and also can be configured
6900 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6903 * Improvements in C++ mangling/demangling.
6905 This release has much better g++ debugging, specifically in name
6906 mangling/demangling, virtual function calls, print virtual table,
6907 call methods, ...etc.
6909 *** Changes in GDB-4.10:
6911 * User visible changes:
6913 Remote debugging using the GDB-specific (`target remote') protocol now
6914 supports the `load' command. This is only useful if you have some
6915 other way of getting the stub to the target system, and you can put it
6916 somewhere in memory where it won't get clobbered by the download.
6918 Filename completion now works.
6920 When run under emacs mode, the "info line" command now causes the
6921 arrow to point to the line specified. Also, "info line" prints
6922 addresses in symbolic form (as well as hex).
6924 All vxworks based targets now support a user settable option, called
6925 vxworks-timeout. This option represents the number of seconds gdb
6926 should wait for responses to rpc's. You might want to use this if
6927 your vxworks target is, perhaps, a slow software simulator or happens
6928 to be on the far side of a thin network line.
6932 This release contains support for using a DEC alpha as a GDB host for
6933 cross debugging. Native alpha debugging is not supported yet.
6936 *** Changes in GDB-4.9:
6940 This is the first GDB release which is accompanied by a matching testsuite.
6941 The testsuite requires installation of dejagnu, which should be available
6942 via ftp from most sites that carry GNU software.
6946 'Cfront' style demangling has had its name changed to 'ARM' style, to
6947 emphasize that it was written from the specifications in the C++ Annotated
6948 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6949 disclaimers, it still generated too much confusion with users attempting to
6950 use gdb with AT&T cfront.
6954 GDB now uses a standard remote interface to a simulator library.
6955 So far, the library contains simulators for the Zilog Z8001/2, the
6956 Hitachi H8/300, H8/500 and Super-H.
6958 * New targets supported
6960 H8/300 simulator h8300-hitachi-hms or h8300hms
6961 H8/500 simulator h8500-hitachi-hms or h8500hms
6962 SH simulator sh-hitachi-hms or sh
6963 Z8000 simulator z8k-zilog-none or z8ksim
6964 IDT MIPS board over serial line mips-idt-ecoff
6966 Cross-debugging to GO32 targets is supported. It requires a custom
6967 version of the i386-stub.c module which is integrated with the
6968 GO32 memory extender.
6970 * New remote protocols
6972 MIPS remote debugging protocol.
6974 * New source languages supported
6976 This version includes preliminary support for Chill, a Pascal like language
6977 used by telecommunications companies. Chill support is also being integrated
6978 into the GNU compiler, but we don't know when it will be publically available.
6981 *** Changes in GDB-4.8:
6983 * HP Precision Architecture supported
6985 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6986 version of this support was available as a set of patches from the
6987 University of Utah. GDB does not support debugging of programs
6988 compiled with the HP compiler, because HP will not document their file
6989 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6990 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6992 Many problems in the preliminary version have been fixed.
6994 * Faster and better demangling
6996 We have improved template demangling and fixed numerous bugs in the GNU style
6997 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6998 character types (wchar_t) are now supported. Demangling of each symbol is now
6999 only done once, and is cached when the symbol table for a file is read in.
7000 This results in a small increase in memory usage for C programs, a moderate
7001 increase in memory usage for C++ programs, and a fantastic speedup in
7004 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7005 from the specifications in the Annotated Reference Manual, which AT&T's
7006 compiler does not actually implement.
7008 * G++ multiple inheritance compiler problem
7010 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7011 inheritance lattices was reworked to properly discover ambiguities. We
7012 recently found an example which causes this new algorithm to fail in a
7013 very subtle way, producing bad debug information for those classes.
7014 The file 'gcc.patch' (in this directory) can be applied to gcc to
7015 circumvent the problem. A future GCC release will contain a complete
7018 The previous G++ debug info problem (mentioned below for the gdb-4.7
7019 release) is fixed in gcc version 2.3.2.
7021 * Improved configure script
7023 The `configure' script will now attempt to guess your system type if
7024 you don't supply a host system type. The old scheme of supplying a
7025 host system triplet is preferable over using this. All the magic is
7026 done in the new `config.guess' script. Examine it for details.
7028 We have also brought our configure script much more in line with the FSF's
7029 version. It now supports the --with-xxx options. In particular,
7030 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7031 The resulting GDB will not be able to read arbitrary object file formats --
7032 only the format ``expected'' to be used on the configured target system.
7033 We hope to make this the default in a future release.
7035 * Documentation improvements
7037 There's new internal documentation on how to modify GDB, and how to
7038 produce clean changes to the code. We implore people to read it
7039 before submitting changes.
7041 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7042 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7043 `info' files are also provided. To build `info' files from scratch,
7044 you will need the latest `makeinfo' release, which will be available in
7045 a future texinfo-X.Y release.
7047 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7048 We're not sure exactly which versions have this problem, but it has
7049 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7050 or better. If that isn't possible, there is a patch in
7051 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7052 around this problem.
7056 GDB now supports array constants that can be used in expressions typed in by
7057 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7058 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7061 The new directory `gdb/sparclite' contains a program that demonstrates
7062 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7064 * New native hosts supported
7066 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7067 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7069 * New targets supported
7071 AMD 29k family via UDI a29k-amd-udi or udi29k
7073 * New file formats supported
7075 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7076 HPUX core files, and SCO 3.2v2 core files.
7080 Attaching to processes now works again; thanks for the many bug reports.
7082 We have also stomped on a bunch of core dumps caused by
7083 printf_filtered("%s") problems.
7085 We eliminated a copyright problem on the rpc and ptrace header files
7086 for VxWorks, which was discovered at the last minute during the 4.7
7087 release. You should now be able to build a VxWorks GDB.
7089 You can now interrupt gdb while an attached process is running. This
7090 will cause the attached process to stop, and give control back to GDB.
7092 We fixed problems caused by using too many file descriptors
7093 for reading symbols from object files and libraries. This was
7094 especially a problem for programs that used many (~100) shared
7097 The `step' command now only enters a subroutine if there is line number
7098 information for the subroutine. Otherwise it acts like the `next'
7099 command. Previously, `step' would enter subroutines if there was
7100 any debugging information about the routine. This avoids problems
7101 when using `cc -g1' on MIPS machines.
7103 * Internal improvements
7105 GDB's internal interfaces have been improved to make it easier to support
7106 debugging of multiple languages in the future.
7108 GDB now uses a common structure for symbol information internally.
7109 Minimal symbols (derived from linkage symbols in object files), partial
7110 symbols (from a quick scan of debug information), and full symbols
7111 contain a common subset of information, making it easier to write
7112 shared code that handles any of them.
7114 * New command line options
7116 We now accept --silent as an alias for --quiet.
7120 The memory-mapped-malloc library is now licensed under the GNU Library
7121 General Public License.
7123 *** Changes in GDB-4.7:
7125 * Host/native/target split
7127 GDB has had some major internal surgery to untangle the support for
7128 hosts and remote targets. Now, when you configure GDB for a remote
7129 target, it will no longer load in all of the support for debugging
7130 local programs on the host. When fully completed and tested, this will
7131 ensure that arbitrary host/target combinations are possible.
7133 The primary conceptual shift is to separate the non-portable code in
7134 GDB into three categories. Host specific code is required any time GDB
7135 is compiled on that host, regardless of the target. Target specific
7136 code relates to the peculiarities of the target, but can be compiled on
7137 any host. Native specific code is everything else: it can only be
7138 built when the host and target are the same system. Child process
7139 handling and core file support are two common `native' examples.
7141 GDB's use of /proc for controlling Unix child processes is now cleaner.
7142 It has been split out into a single module under the `target_ops' vector,
7143 plus two native-dependent functions for each system that uses /proc.
7145 * New hosts supported
7147 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7148 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7149 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7151 * New targets supported
7153 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7154 68030 and CPU32 m68030-*-*, m68332-*-*
7156 * New native hosts supported
7158 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7159 (386bsd is not well tested yet)
7160 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7162 * New file formats supported
7164 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7165 supports reading of `a.out.adobe' object files, which are an a.out
7166 format extended with minimal information about multiple sections.
7170 `show copying' is the same as the old `info copying'.
7171 `show warranty' is the same as `info warrantee'.
7172 These were renamed for consistency. The old commands continue to work.
7174 `info handle' is a new alias for `info signals'.
7176 You can now define pre-command hooks, which attach arbitrary command
7177 scripts to any command. The commands in the hook will be executed
7178 prior to the user's command. You can also create a hook which will be
7179 executed whenever the program stops. See gdb.texinfo.
7183 We now deal with Cfront style name mangling, and can even extract type
7184 info from mangled symbols. GDB can automatically figure out which
7185 symbol mangling style your C++ compiler uses.
7187 Calling of methods and virtual functions has been improved as well.
7191 The crash that occured when debugging Sun Ansi-C compiled binaries is
7192 fixed. This was due to mishandling of the extra N_SO stabs output
7195 We also finally got Ultrix 4.2 running in house, and fixed core file
7196 support, with help from a dozen people on the net.
7198 John M. Farrell discovered that the reason that single-stepping was so
7199 slow on all of the Mips based platforms (primarily SGI and DEC) was
7200 that we were trying to demangle and lookup a symbol used for internal
7201 purposes on every instruction that was being stepped through. Changing
7202 the name of that symbol so that it couldn't be mistaken for a C++
7203 mangled symbol sped things up a great deal.
7205 Rich Pixley sped up symbol lookups in general by getting much smarter
7206 about when C++ symbol mangling is necessary. This should make symbol
7207 completion (TAB on the command line) much faster. It's not as fast as
7208 we'd like, but it's significantly faster than gdb-4.6.
7212 A new user controllable variable 'call_scratch_address' can
7213 specify the location of a scratch area to be used when GDB
7214 calls a function in the target. This is necessary because the
7215 usual method of putting the scratch area on the stack does not work
7216 in systems that have separate instruction and data spaces.
7218 We integrated changes to support the 29k UDI (Universal Debugger
7219 Interface), but discovered at the last minute that we didn't have all
7220 of the appropriate copyright paperwork. We are working with AMD to
7221 resolve this, and hope to have it available soon.
7225 We have sped up the remote serial line protocol, especially for targets
7226 with lots of registers. It now supports a new `expedited status' ('T')
7227 message which can be used in place of the existing 'S' status message.
7228 This allows the remote stub to send only the registers that GDB
7229 needs to make a quick decision about single-stepping or conditional
7230 breakpoints, eliminating the need to fetch the entire register set for
7231 each instruction being stepped through.
7233 The GDB remote serial protocol now implements a write-through cache for
7234 registers, only re-reading the registers if the target has run.
7236 There is also a new remote serial stub for SPARC processors. You can
7237 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7238 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7239 processor with a serial port.
7243 Configure.in files have become much easier to read and modify. A new
7244 `table driven' format makes it more obvious what configurations are
7245 supported, and what files each one uses.
7249 There is a new opcodes library which will eventually contain all of the
7250 disassembly routines and opcode tables. At present, it only contains
7251 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7252 disassembler (binutils/objdump) to share these routines.
7254 The libiberty library is now copylefted under the GNU Library General
7255 Public License. This allows more liberal use, and was done so libg++
7256 can use it. This makes no difference to GDB, since the Library License
7257 grants all the rights from the General Public License.
7261 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7262 reference to the stabs symbol info used by the debugger. It is (as far
7263 as we know) the only published document on this fascinating topic. We
7264 encourage you to read it, compare it to the stabs information on your
7265 system, and send improvements on the document in general (to
7266 bug-gdb@prep.ai.mit.edu).
7268 And, of course, many bugs have been fixed.
7271 *** Changes in GDB-4.6:
7273 * Better support for C++ function names
7275 GDB now accepts as input the "demangled form" of C++ overloaded function
7276 names and member function names, and can do command completion on such names
7277 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7278 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7279 Make use of command completion, it is your friend.
7281 GDB also now accepts a variety of C++ mangled symbol formats. They are
7282 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7283 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7284 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7285 for the list of formats.
7287 * G++ symbol mangling problem
7289 Recent versions of gcc have a bug in how they emit debugging information for
7290 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7291 directory) can be applied to gcc to fix the problem. Alternatively, if you
7292 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7293 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7294 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7297 * New 'maintenance' command
7299 All of the commands related to hacking GDB internals have been moved out of
7300 the main command set, and now live behind the 'maintenance' command. This
7301 can also be abbreviated as 'mt'. The following changes were made:
7303 dump-me -> maintenance dump-me
7304 info all-breakpoints -> maintenance info breakpoints
7305 printmsyms -> maintenance print msyms
7306 printobjfiles -> maintenance print objfiles
7307 printpsyms -> maintenance print psymbols
7308 printsyms -> maintenance print symbols
7310 The following commands are new:
7312 maintenance demangle Call internal GDB demangler routine to
7313 demangle a C++ link name and prints the result.
7314 maintenance print type Print a type chain for a given symbol
7316 * Change to .gdbinit file processing
7318 We now read the $HOME/.gdbinit file before processing the argv arguments
7319 (e.g. reading symbol files or core files). This allows global parameters to
7320 be set, which will apply during the symbol reading. The ./.gdbinit is still
7321 read after argv processing.
7323 * New hosts supported
7325 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7327 GNU/Linux support i386-unknown-linux or linux
7329 We are also including code to support the HP/PA running BSD and HPUX. This
7330 is almost guaranteed not to work, as we didn't have time to test or build it
7331 for this release. We are including it so that the more adventurous (or
7332 masochistic) of you can play with it. We also had major problems with the
7333 fact that the compiler that we got from HP doesn't support the -g option.
7336 * New targets supported
7338 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7340 * More smarts about finding #include files
7342 GDB now remembers the compilation directory for all include files, and for
7343 all files from which C is generated (like yacc and lex sources). This
7344 greatly improves GDB's ability to find yacc/lex sources, and include files,
7345 especially if you are debugging your program from a directory different from
7346 the one that contains your sources.
7348 We also fixed a bug which caused difficulty with listing and setting
7349 breakpoints in include files which contain C code. (In the past, you had to
7350 try twice in order to list an include file that you hadn't looked at before.)
7352 * Interesting infernals change
7354 GDB now deals with arbitrary numbers of sections, where the symbols for each
7355 section must be relocated relative to that section's landing place in the
7356 target's address space. This work was needed to support ELF with embedded
7357 stabs used by Solaris-2.0.
7359 * Bug fixes (of course!)
7361 There have been loads of fixes for the following things:
7362 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7363 i960, stabs, DOS(GO32), procfs, etc...
7365 See the ChangeLog for details.
7367 *** Changes in GDB-4.5:
7369 * New machines supported (host and target)
7371 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7373 SGI Irix-4.x mips-sgi-irix4 or iris4
7375 * New malloc package
7377 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7378 Mmalloc is capable of handling mutiple heaps of memory. It is also
7379 capable of saving a heap to a file, and then mapping it back in later.
7380 This can be used to greatly speedup the startup of GDB by using a
7381 pre-parsed symbol table which lives in a mmalloc managed heap. For
7382 more details, please read mmalloc/mmalloc.texi.
7386 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7387 'help info proc' for details.
7389 * MIPS ecoff symbol table format
7391 The code that reads MIPS symbol table format is now supported on all hosts.
7392 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7395 * File name changes for MS-DOS
7397 Many files in the config directories have been renamed to make it easier to
7398 support GDB on MS-DOSe systems (which have very restrictive file name
7399 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7400 environment) is close to working but has some remaining problems. Note
7401 that debugging of DOS programs is not supported, due to limitations
7402 in the ``operating system'', but it can be used to host cross-debugging.
7404 * Cross byte order fixes
7406 Many fixes have been made to support cross debugging of Sparc and MIPS
7407 targets from hosts whose byte order differs.
7409 * New -mapped and -readnow options
7411 If memory-mapped files are available on your system through the 'mmap'
7412 system call, you can use the -mapped option on the `file' or
7413 `symbol-file' commands to cause GDB to write the symbols from your
7414 program into a reusable file. If the program you are debugging is
7415 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7416 Future GDB debugging sessions will notice the presence of this file,
7417 and will quickly map in symbol information from it, rather than reading
7418 the symbol table from the executable program. Using the '-mapped'
7419 option in a GDB `file' or `symbol-file' command has the same effect as
7420 starting GDB with the '-mapped' command-line option.
7422 You can cause GDB to read the entire symbol table immediately by using
7423 the '-readnow' option with any of the commands that load symbol table
7424 information (or on the GDB command line). This makes the command
7425 slower, but makes future operations faster.
7427 The -mapped and -readnow options are typically combined in order to
7428 build a `fred.syms' file that contains complete symbol information.
7429 A simple GDB invocation to do nothing but build a `.syms' file for future
7432 gdb -batch -nx -mapped -readnow programname
7434 The `.syms' file is specific to the host machine on which GDB is run.
7435 It holds an exact image of GDB's internal symbol table. It cannot be
7436 shared across multiple host platforms.
7438 * longjmp() handling
7440 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7441 siglongjmp() without losing control. This feature has not yet been ported to
7442 all systems. It currently works on many 386 platforms, all MIPS-based
7443 platforms (SGI, DECstation, etc), and Sun3/4.
7447 Preliminary work has been put in to support the new Solaris OS from Sun. At
7448 this time, it can control and debug processes, but it is not capable of
7453 As always, many many bug fixes. The major areas were with g++, and mipsread.
7454 People using the MIPS-based platforms should experience fewer mysterious
7455 crashes and trashed symbol tables.
7457 *** Changes in GDB-4.4:
7459 * New machines supported (host and target)
7461 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7463 BSD Reno on Vax vax-dec-bsd
7464 Ultrix on Vax vax-dec-ultrix
7466 * New machines supported (target)
7468 AMD 29000 embedded, using EBMON a29k-none-none
7472 GDB continues to improve its handling of C++. `References' work better.
7473 The demangler has also been improved, and now deals with symbols mangled as
7474 per the Annotated C++ Reference Guide.
7476 GDB also now handles `stabs' symbol information embedded in MIPS
7477 `ecoff' symbol tables. Since the ecoff format was not easily
7478 extensible to handle new languages such as C++, this appeared to be a
7479 good way to put C++ debugging info into MIPS binaries. This option
7480 will be supported in the GNU C compiler, version 2, when it is
7483 * New features for SVR4
7485 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7486 shared libraries. Debugging dynamically linked programs should present
7487 only minor differences from debugging statically linked programs.
7489 The `info proc' command will print out information about any process
7490 on an SVR4 system (including the one you are debugging). At the moment,
7491 it prints the address mappings of the process.
7493 If you bring up GDB on another SVR4 system, please send mail to
7494 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7496 * Better dynamic linking support in SunOS
7498 Reading symbols from shared libraries which contain debugging symbols
7499 now works properly. However, there remain issues such as automatic
7500 skipping of `transfer vector' code during function calls, which
7501 make it harder to debug code in a shared library, than to debug the
7502 same code linked statically.
7506 GDB is now using the latest `getopt' routines from the FSF. This
7507 version accepts the -- prefix for options with long names. GDB will
7508 continue to accept the old forms (-option and +option) as well.
7509 Various single letter abbreviations for options have been explicity
7510 added to the option table so that they won't get overshadowed in the
7511 future by other options that begin with the same letter.
7515 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7516 Many assorted bugs have been handled. Many more remain to be handled.
7517 See the various ChangeLog files (primarily in gdb and bfd) for details.
7520 *** Changes in GDB-4.3:
7522 * New machines supported (host and target)
7524 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7525 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7526 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7528 * Almost SCO Unix support
7530 We had hoped to support:
7531 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7532 (except for core file support), but we discovered very late in the release
7533 that it has problems with process groups that render gdb unusable. Sorry
7534 about that. I encourage people to fix it and post the fixes.
7536 * Preliminary ELF and DWARF support
7538 GDB can read ELF object files on System V Release 4, and can handle
7539 debugging records for C, in DWARF format, in ELF files. This support
7540 is preliminary. If you bring up GDB on another SVR4 system, please
7541 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7546 GDB now uses the latest `readline' library. One user-visible change
7547 is that two tabs will list possible command completions, which previously
7548 required typing M-? (meta-question mark, or ESC ?).
7552 The `stepi' bug that many of you noticed has been squashed.
7553 Many bugs in C++ have been handled. Many more remain to be handled.
7554 See the various ChangeLog files (primarily in gdb and bfd) for details.
7556 * State of the MIPS world (in case you wondered):
7558 GDB can understand the symbol tables emitted by the compilers
7559 supplied by most vendors of MIPS-based machines, including DEC. These
7560 symbol tables are in a format that essentially nobody else uses.
7562 Some versions of gcc come with an assembler post-processor called
7563 mips-tfile. This program is required if you want to do source-level
7564 debugging of gcc-compiled programs. I believe FSF does not ship
7565 mips-tfile with gcc version 1, but it will eventually come with gcc
7568 Debugging of g++ output remains a problem. g++ version 1.xx does not
7569 really support it at all. (If you're lucky, you should be able to get
7570 line numbers and stack traces to work, but no parameters or local
7571 variables.) With some work it should be possible to improve the
7574 When gcc version 2 is released, you will have somewhat better luck.
7575 However, even then you will get confusing results for inheritance and
7578 We will eventually provide full debugging of g++ output on
7579 DECstations. This will probably involve some kind of stabs-in-ecoff
7580 encapulation, but the details have not been worked out yet.
7583 *** Changes in GDB-4.2:
7585 * Improved configuration
7587 Only one copy of `configure' exists now, and it is not self-modifying.
7588 Porting BFD is simpler.
7592 The `step' and `next' commands now only stop at the first instruction
7593 of a source line. This prevents the multiple stops that used to occur
7594 in switch statements, for-loops, etc. `Step' continues to stop if a
7595 function that has debugging information is called within the line.
7599 Lots of small bugs fixed. More remain.
7601 * New host supported (not target)
7603 Intel 386 PC clone running Mach i386-none-mach
7606 *** Changes in GDB-4.1:
7608 * Multiple source language support
7610 GDB now has internal scaffolding to handle several source languages.
7611 It determines the type of each source file from its filename extension,
7612 and will switch expression parsing and number formatting to match the
7613 language of the function in the currently selected stack frame.
7614 You can also specifically set the language to be used, with
7615 `set language c' or `set language modula-2'.
7619 GDB now has preliminary support for the GNU Modula-2 compiler,
7620 currently under development at the State University of New York at
7621 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7622 continue through the fall of 1991 and into 1992.
7624 Other Modula-2 compilers are currently not supported, and attempting to
7625 debug programs compiled with them will likely result in an error as the
7626 symbol table is read. Feel free to work on it, though!
7628 There are hooks in GDB for strict type checking and range checking,
7629 in the `Modula-2 philosophy', but they do not currently work.
7633 GDB can now write to executable and core files (e.g. patch
7634 a variable's value). You must turn this switch on, specify
7635 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7636 by assigning a new value to a variable. Modifications take
7639 * Automatic SunOS shared library reading
7641 When you run your program, GDB automatically determines where its
7642 shared libraries (if any) have been loaded, and reads their symbols.
7643 The `share' command is no longer needed. This also works when
7644 examining core files.
7648 You can specify the number of lines that the `list' command shows.
7651 * New machines supported (host and target)
7653 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7654 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7655 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7657 * New hosts supported (not targets)
7659 IBM RT/PC: romp-ibm-aix or rtpc
7661 * New targets supported (not hosts)
7663 AMD 29000 embedded with COFF a29k-none-coff
7664 AMD 29000 embedded with a.out a29k-none-aout
7665 Ultracomputer remote kernel debug a29k-nyu-kern
7667 * New remote interfaces
7673 *** Changes in GDB-4.0:
7677 Wide output is wrapped at good places to make the output more readable.
7679 Gdb now supports cross-debugging from a host machine of one type to a
7680 target machine of another type. Communication with the target system
7681 is over serial lines. The ``target'' command handles connecting to the
7682 remote system; the ``load'' command will download a program into the
7683 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7684 also supports debugging of realtime processes running under VxWorks,
7685 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7686 stub on the target system.
7688 New CPUs supported include the AMD 29000 and Intel 960.
7690 GDB now reads object files and symbol tables via a ``binary file''
7691 library, which allows a single copy of GDB to debug programs of multiple
7692 object file types such as a.out and coff.
7694 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7695 refcard.dvi and refcard.ps are available to format it).
7698 * Control-Variable user interface simplified
7700 All variables that control the operation of the debugger can be set
7701 by the ``set'' command, and displayed by the ``show'' command.
7703 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7704 ``Show prompt'' produces the response:
7705 Gdb's prompt is new-gdb=>.
7707 What follows are the NEW set commands. The command ``help set'' will
7708 print a complete list of old and new set commands. ``help set FOO''
7709 will give a longer description of the variable FOO. ``show'' will show
7710 all of the variable descriptions and their current settings.
7712 confirm on/off: Enables warning questions for operations that are
7713 hard to recover from, e.g. rerunning the program while
7714 it is already running. Default is ON.
7716 editing on/off: Enables EMACS style command line editing
7717 of input. Previous lines can be recalled with
7718 control-P, the current line can be edited with control-B,
7719 you can search for commands with control-R, etc.
7722 history filename NAME: NAME is where the gdb command history
7723 will be stored. The default is .gdb_history,
7724 or the value of the environment variable
7727 history size N: The size, in commands, of the command history. The
7728 default is 256, or the value of the environment variable
7731 history save on/off: If this value is set to ON, the history file will
7732 be saved after exiting gdb. If set to OFF, the
7733 file will not be saved. The default is OFF.
7735 history expansion on/off: If this value is set to ON, then csh-like
7736 history expansion will be performed on
7737 command line input. The default is OFF.
7739 radix N: Sets the default radix for input and output. It can be set
7740 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7741 in the current radix, so "set radix 10" is always a no-op.
7743 height N: This integer value is the number of lines on a page. Default
7744 is 24, the current `stty rows'' setting, or the ``li#''
7745 setting from the termcap entry matching the environment
7748 width N: This integer value is the number of characters on a line.
7749 Default is 80, the current `stty cols'' setting, or the ``co#''
7750 setting from the termcap entry matching the environment
7753 Note: ``set screensize'' is obsolete. Use ``set height'' and
7754 ``set width'' instead.
7756 print address on/off: Print memory addresses in various command displays,
7757 such as stack traces and structure values. Gdb looks
7758 more ``symbolic'' if you turn this off; it looks more
7759 ``machine level'' with it on. Default is ON.
7761 print array on/off: Prettyprint arrays. New convenient format! Default
7764 print demangle on/off: Print C++ symbols in "source" form if on,
7767 print asm-demangle on/off: Same, for assembler level printouts
7770 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7773 * Support for Epoch Environment.
7775 The epoch environment is a version of Emacs v18 with windowing. One
7776 new command, ``inspect'', is identical to ``print'', except that if you
7777 are running in the epoch environment, the value is printed in its own
7781 * Support for Shared Libraries
7783 GDB can now debug programs and core files that use SunOS shared libraries.
7784 Symbols from a shared library cannot be referenced
7785 before the shared library has been linked with the program (this
7786 happens after you type ``run'' and before the function main() is entered).
7787 At any time after this linking (including when examining core files
7788 from dynamically linked programs), gdb reads the symbols from each
7789 shared library when you type the ``sharedlibrary'' command.
7790 It can be abbreviated ``share''.
7792 sharedlibrary REGEXP: Load shared object library symbols for files
7793 matching a unix regular expression. No argument
7794 indicates to load symbols for all shared libraries.
7796 info sharedlibrary: Status of loaded shared libraries.
7801 A watchpoint stops execution of a program whenever the value of an
7802 expression changes. Checking for this slows down execution
7803 tremendously whenever you are in the scope of the expression, but is
7804 quite useful for catching tough ``bit-spreader'' or pointer misuse
7805 problems. Some machines such as the 386 have hardware for doing this
7806 more quickly, and future versions of gdb will use this hardware.
7808 watch EXP: Set a watchpoint (breakpoint) for an expression.
7810 info watchpoints: Information about your watchpoints.
7812 delete N: Deletes watchpoint number N (same as breakpoints).
7813 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7814 enable N: Re-enables watchpoint number N (same as breakpoints).
7817 * C++ multiple inheritance
7819 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7822 * C++ exception handling
7824 Gdb now supports limited C++ exception handling. Besides the existing
7825 ability to breakpoint on an exception handler, gdb can breakpoint on
7826 the raising of an exception (before the stack is peeled back to the
7829 catch FOO: If there is a FOO exception handler in the dynamic scope,
7830 set a breakpoint to catch exceptions which may be raised there.
7831 Multiple exceptions (``catch foo bar baz'') may be caught.
7833 info catch: Lists all exceptions which may be caught in the
7834 current stack frame.
7837 * Minor command changes
7839 The command ``call func (arg, arg, ...)'' now acts like the print
7840 command, except it does not print or save a value if the function's result
7841 is void. This is similar to dbx usage.
7843 The ``up'' and ``down'' commands now always print the frame they end up
7844 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7845 frames without printing.
7847 * New directory command
7849 'dir' now adds directories to the FRONT of the source search path.
7850 The path starts off empty. Source files that contain debug information
7851 about the directory in which they were compiled can be found even
7852 with an empty path; Sun CC and GCC include this information. If GDB can't
7853 find your source file in the current directory, type "dir .".
7855 * Configuring GDB for compilation
7857 For normal use, type ``./configure host''. See README or gdb.texinfo
7860 GDB now handles cross debugging. If you are remotely debugging between
7861 two different machines, type ``./configure host -target=targ''.
7862 Host is the machine where GDB will run; targ is the machine
7863 where the program that you are debugging will run.