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
73 * 'thread-exited' event is now available in the annotations interface.
75 * New built-in convenience variables $_gdb_major and $_gdb_minor
76 provide the GDB version. They are handy for conditionally using
77 features available only in or since specific GDB versions, in
78 scripts that should work error-free with many different versions,
79 such as in system-wide init files.
81 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
82 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
83 of the GDB settings and the GDB maintenance settings. They are handy
84 for changing the logic of user defined commands depending on the
87 * GDB now supports Thread Local Storage (TLS) variables on several
88 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
89 architectures require kernel changes. TLS is not yet supported for
90 amd64 and i386 process core dumps.
92 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
93 addresses that required unmasking are shown in the backtrace with the
96 * Two new convenience functions $_cimag and $_creal that extract the
97 imaginary and real parts respectively from complex numbers.
99 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
100 provide the exitcode or exit status of the shell commands launched by
101 GDB commands such as "shell", "pipe" and "make".
103 * The command define-prefix can now define user defined prefix commands.
104 User defined commands can now be defined using these user defined prefix
107 * Command names can now use the . character.
109 * The RX port now supports XML target descriptions.
111 * GDB now shows the Ada task names at more places, e.g. in task switching
114 * GDB can now be compiled with Python 3 on Windows.
116 * New convenience variable $_ada_exception holds the address of the
117 Ada exception being thrown. This is set by Ada-related catchpoints.
119 * GDB can now place breakpoints on nested functions and subroutines in
120 Fortran code. The '::' operator can be used between parent and
121 child scopes when placing breakpoints, for example:
123 (gdb) break outer_function::inner_function
125 The 'outer_function::' prefix is only needed if 'inner_function' is
126 not visible in the current scope.
128 * In addition to the system-wide gdbinit file, if configured with
129 --with-system-gdbinit-dir, GDB will now also load files in that directory
130 as system gdbinit files, unless the -nx or -n flag is provided. Files
131 with extensions .gdb, .py and .scm are supported as long as GDB was
132 compiled with support for that language.
134 * GDB now supports multithreaded symbol loading for higher performance.
135 This feature is still in testing, so it is disabled by default. You
136 can turn it on using 'maint set worker-threads unlimited'.
138 * Multi-target debugging support
140 GDB now supports debugging multiple target connections
141 simultaneously. For example, you can now have each inferior
142 connected to different remote servers running in different machines,
143 or have one inferior debugging a local native process, an inferior
144 debugging a core dump, etc.
146 This support is experimental and comes with some limitations -- you
147 can only resume multiple targets simultaneously if all targets
148 support non-stop mode, and all remote stubs or servers must support
149 the same set of remote protocol features exactly. See also "info
150 connections" and "add-inferior -no-connection" below, and "maint set
151 target-non-stop" in the user manual.
155 ** The gdb.Value type has a new method 'format_string' which returns a
156 string representing the value. The formatting is controlled by the
157 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
158 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
159 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
161 ** gdb.Type has a new property 'objfile' which returns the objfile the
164 ** The frame information printed by the python frame filtering code
165 is now consistent with what the 'backtrace' command prints when
166 there are no filters, or when the 'backtrace' '-no-filters' option
169 ** The new function gdb.lookup_static_symbol can be used to look up
170 symbols with static linkage.
172 ** The new function gdb.lookup_static_symbols can be used to look up
173 all static symbols with static linkage.
175 ** gdb.Objfile has new methods 'lookup_global_symbol' and
176 'lookup_static_symbol' to lookup a symbol from this objfile only.
178 ** gdb.Block now supports the dictionary syntax for accessing symbols in
179 this block (e.g. block['local_variable']).
183 | [COMMAND] | SHELL_COMMAND
184 | -d DELIM COMMAND DELIM SHELL_COMMAND
185 pipe [COMMAND] | SHELL_COMMAND
186 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
187 Executes COMMAND and sends its output to SHELL_COMMAND.
188 With no COMMAND, repeat the last executed command
189 and send its output to SHELL_COMMAND.
191 define-prefix COMMAND
192 Define or mark a command as a user-defined prefix command.
194 with SETTING [VALUE] [-- COMMAND]
195 w SETTING [VALUE] [-- COMMAND]
196 Temporarily set SETTING, run COMMAND, and restore SETTING.
197 Usage: with SETTING -- COMMAND
198 With no COMMAND, repeats the last executed command.
199 SETTING is any GDB setting you can change with the "set"
200 subcommands. For example, 'with language c -- print someobj'
201 temporarily switches to the C language in order to print someobj.
202 Settings can be combined: 'w lang c -- w print elements unlimited --
203 usercmd' switches to the C language and runs usercmd with no limit
204 of array elements to print.
206 maint with SETTING [VALUE] [-- COMMAND]
207 Like "with", but works with "maintenance set" settings.
209 set may-call-functions [on|off]
210 show may-call-functions
211 This controls whether GDB will attempt to call functions in
212 the program, such as with expressions in the print command. It
213 defaults to on. Calling functions in the program being debugged
214 can have undesired side effects. It is now possible to forbid
215 such function calls. If function calls are forbidden, GDB will throw
216 an error when a command (such as print expression) calls a function
219 set print finish [on|off]
221 This controls whether the `finish' command will display the value
222 that is returned by the current function. When `off', the value is
223 still entered into the value history, but it is not printed. The
228 Allows deeply nested structures to be simplified when printing by
229 replacing deeply nested parts (beyond the max-depth) with ellipses.
230 The default max-depth is 20, but this can be set to unlimited to get
231 the old behavior back.
233 set print raw-values [on|off]
234 show print raw-values
235 By default, GDB applies the enabled pretty printers when printing a
236 value. This allows to ignore the enabled pretty printers for a series
237 of commands. The default is 'off'.
239 set logging debugredirect [on|off]
240 By default, GDB debug output will go to both the terminal and the logfile.
241 Set if you want debug output to go only to the log file.
243 set style title foreground COLOR
244 set style title background COLOR
245 set style title intensity VALUE
246 Control the styling of titles.
248 set style highlight foreground COLOR
249 set style highlight background COLOR
250 set style highlight intensity VALUE
251 Control the styling of highlightings.
253 maint set worker-threads
254 maint show worker-threads
255 Control the number of worker threads that can be used by GDB. The
256 default is 0. "unlimited" lets GDB choose a number that is
257 reasonable. Currently worker threads are only used when demangling
258 the names of linker symbols.
260 set style tui-border foreground COLOR
261 set style tui-border background COLOR
262 Control the styling of TUI borders.
264 set style tui-active-border foreground COLOR
265 set style tui-active-border background COLOR
266 Control the styling of the active TUI border.
268 maint set test-settings KIND
269 maint show test-settings KIND
270 A set of commands used by the testsuite for exercising the settings
273 maint set tui-resize-message [on|off]
274 maint show tui-resize-message
275 Control whether GDB prints a message each time the terminal is
276 resized when in TUI mode. This is primarily useful for testing the
279 set print frame-info [short-location|location|location-and-address
280 |source-and-location|source-line|auto]
281 show print frame-info
282 This controls what frame information is printed by the commands printing
283 a frame. This setting will e.g. influence the behaviour of 'backtrace',
284 'frame', 'stepi'. The python frame filtering also respect this setting.
285 The 'backtrace' '-frame-info' option can override this global setting.
287 set tui compact-source
288 show tui compact-source
290 Enable the "compact" display mode for the TUI source window. The
291 compact display uses only as much space as is needed for the line
292 numbers in the current file, and only a single space to separate the
293 line numbers from the source.
295 info modules [-q] [REGEXP]
296 Return a list of Fortran modules matching REGEXP, or all modules if
299 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
300 Return a list of functions within all modules, grouped by module.
301 The list of functions can be restricted with the optional regular
302 expressions. MODULE_REGEXP matches against the module name,
303 TYPE_REGEXP matches against the function type signature, and REGEXP
304 matches against the function name.
306 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
307 Return a list of variables within all modules, grouped by module.
308 The list of variables can be restricted with the optional regular
309 expressions. MODULE_REGEXP matches against the module name,
310 TYPE_REGEXP matches against the variable type, and REGEXP matches
311 against the variable name.
313 set debug remote-packet-max-chars
314 show debug remote-packet-max-chars
315 Controls the number of characters to output in a remote packet when using
317 The default is 512 bytes.
320 Lists the target connections currently in use.
325 The "help" command uses the title style to enhance the
326 readibility of its output by styling the classes and
330 Similarly to "help", the "apropos" command also uses the
331 title style for the command names. "apropos" accepts now
332 a flag "-v" (verbose) to show the full documentation
333 of matching commands and to use the highlight style to mark
334 the documentation parts matching REGEXP.
338 The GDB printf and eval commands can now print C-style and Ada-style
339 string convenience variables without calling functions in the program.
340 This allows to do formatted printing of strings without having
341 a running inferior, or when debugging a core dump.
343 info sources [-dirname | -basename] [--] [REGEXP]
344 This command has now optional arguments to only print the files
345 whose names match REGEXP. The arguments -dirname and -basename
346 allow to restrict matching respectively to the dirname and basename
350 The "show style" and its subcommands are now styling
351 a style name in their output using its own style, to help
352 the user visualize the different styles.
354 set print frame-arguments
355 The new value 'presence' indicates to only indicate the presence of
356 arguments using ..., instead of printing argument names and values.
358 set print raw-frame-arguments
359 show print raw-frame-arguments
361 These commands replace the similarly-named "set/show print raw
362 frame-arguments" commands (now with a dash instead of a space). The
363 old commands are now deprecated and may be removed in a future
366 add-inferior [-no-connection]
367 The add-inferior command now supports a "-no-connection" flag that
368 makes the new inferior start with no target connection associated.
369 By default, the new inferior inherits the target connection of the
370 current inferior. See also "info connections".
373 This command's output now includes a new "Connection" column
374 indicating which target connection an inferior is bound to. See
375 "info connections" above.
377 maint test-options require-delimiter
378 maint test-options unknown-is-error
379 maint test-options unknown-is-operand
380 maint show test-options-completion-result
381 Commands used by the testsuite to validate the command options
384 focus, winheight, +, -, >, <
385 These commands are now case-sensitive.
387 * New command options, command completion
389 GDB now has a standard infrastructure to support dash-style command
390 options ('-OPT'). One benefit is that commands that use it can
391 easily support completion of command line arguments. Try "CMD
392 -[TAB]" or "help CMD" to find options supported by a command. Over
393 time, we intend to migrate most commands to this infrastructure. A
394 number of commands got support for new command options in this
397 ** The "print" and "compile print" commands now support a number of
398 options that allow overriding relevant global print settings as
399 set by "set print" subcommands:
403 -array-indexes [on|off]
404 -elements NUMBER|unlimited
409 -repeats NUMBER|unlimited
410 -static-members [on|off]
415 Note that because the "print"/"compile print" commands accept
416 arbitrary expressions which may look like options (including
417 abbreviations), if you specify any command option, then you must
418 use a double dash ("--") to mark the end of argument processing.
420 ** The "backtrace" command now supports a number of options that
421 allow overriding relevant global print settings as set by "set
422 backtrace" and "set print" subcommands:
424 -entry-values no|only|preferred|if-needed|both|compact|default
425 -frame-arguments all|scalars|none
426 -raw-frame-arguments [on|off]
427 -frame-info auto|source-line|location|source-and-location
428 |location-and-address|short-location
432 In addition, the full/no-filters/hide qualifiers are now also
433 exposed as command options too:
439 ** The "frame apply", "tfaas" and "faas" commands similarly now
440 support the following options:
445 ** The new "info sources" options -dirname and -basename options
446 are using the standard '-OPT' infrastructure.
448 All options above can also be abbreviated. The argument of boolean
449 (on/off) options can be 0/1 too, and also the argument is assumed
450 "on" if omitted. This allows writing compact command invocations,
453 (gdb) p -ra -p -o 0 -- *myptr
455 The above is equivalent to:
457 (gdb) print -raw-values -pretty -object off -- *myptr
459 ** The "info types" command now supports the '-q' flag to disable
460 printing of some header information in a similar fashion to "info
461 variables" and "info functions".
463 ** The "info variables", "info functions", and "whereis" commands
464 now take a '-n' flag that excludes non-debug symbols (symbols
465 from the symbol table, not from the debug info such as DWARF)
468 * Completion improvements
470 ** GDB can now complete the options of the "thread apply all" and
471 "taas" commands, and their "-ascending" option can now be
474 ** GDB can now complete the options of the "info threads", "info
475 functions", "info variables", "info locals", and "info args"
478 ** GDB can now complete the options of the "compile file" and
479 "compile code" commands. The "compile file" command now
480 completes on filenames.
482 ** GDB can now complete the backtrace command's
483 "full/no-filters/hide" qualifiers.
485 * In settings, you can now abbreviate "unlimited".
487 E.g., "set print elements u" is now equivalent to "set print
493 This lists all the possible completions for the rest of the line, if it
494 were to be given as a command itself. This is intended for use by MI
495 frontends in cases when separate CLI and MI channels cannot be used.
497 -catch-throw, -catch-rethrow, and -catch-catch
498 These can be used to catch C++ exceptions in a similar fashion to
499 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
501 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
502 These commands are the MI equivalent of the CLI commands 'info
503 functions', 'info types', and 'info variables' respectively.
505 -symbol-info-modules, this is the MI equivalent of the CLI 'info
508 -symbol-info-module-functions and -symbol-info-module-variables.
509 These commands are the MI equivalent of the CLI commands 'info
510 module functions' and 'info module variables'.
514 ** The default version of the MI interpreter is now 3 (-i=mi3).
516 ** The output of information about multi-location breakpoints (which is
517 syntactically incorrect in MI 2) has changed in MI 3. This affects
518 the following commands and events:
522 - =breakpoint-created
523 - =breakpoint-modified
525 The -fix-multi-location-breakpoint-output command can be used to enable
526 this behavior with previous MI versions.
528 ** Backtraces and frames include a new optional field addr_flags which is
529 given after the addr field. On AArch64 this contains PAC if the address
530 has been masked in the frame. On all other targets the field is not
535 The testsuite now creates the files gdb.cmd (containing the arguments
536 used to launch GDB) and gdb.in (containing all the commands sent to
537 GDB) in the output directory for each test script. Multiple invocations
538 are appended with .1, .2, .3 etc.
540 * Building GDB and GDBserver now requires GNU make >= 3.82.
542 Using another implementation of the make program or an earlier version of
543 GNU make to build GDB or GDBserver is not supported.
545 * Building GDB now requires GNU readline >= 7.0.
547 GDB now bundles GNU readline 8.0, but if you choose to use
548 --with-system-readline, only readline >= 7.0 can be used.
550 * The TUI SingleKey keymap is now named "SingleKey". This can be used
551 from .inputrc to bind keys in this keymap. This feature is only
552 available when gdb is built against GNU readline 8.0 or later.
554 * Removed targets and native configurations
556 GDB no longer supports debugging the Cell Broadband Engine. This includes
557 both debugging standalone Cell/B.E. SPU applications and integrated debugging
558 of Cell/B.E. applications that use both the PPU and SPU architectures.
564 * Removed targets and native configurations
566 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
569 *** Changes in GDB 8.3
571 * GDB and GDBserver now support access to additional registers on
572 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
575 * GDB now has experimental support for the compilation and injection of
576 C++ source code into the inferior. This beta release does not include
577 support for several language features, such as templates, constructors,
580 This feature requires GCC 7.1 or higher built with libcp1.so
583 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
584 can be passed using the '[ADDRESS]:PORT' notation, or the regular
585 'ADDRESS:PORT' method.
587 * DWARF index cache: GDB can now automatically save indices of DWARF
588 symbols on disk to speed up further loading of the same binaries.
590 * Ada task switching is now supported on aarch64-elf targets when
591 debugging a program using the Ravenscar Profile. For more information,
592 see the "Tasking Support when using the Ravenscar Profile" section
593 in the GDB user manual.
595 * GDB in batch mode now exits with status 1 if the last command to be
598 * The RISC-V target now supports target descriptions.
600 * System call catchpoints now support system call aliases on FreeBSD.
601 When the ABI of a system call changes in FreeBSD, this is
602 implemented by leaving a compatibility system call using the old ABI
603 at the existing number and allocating a new system call number for
604 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
605 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
606 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
607 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
608 so that a system call catchpoint for the 'kevent' system call will
609 catch invocations of both the 'kevent' and 'freebsd11_kevent'
610 binaries. This ensures that 'kevent' system calls are caught for
611 binaries using either the old or new ABIs.
613 * Terminal styling is now available for the CLI and the TUI. GNU
614 Source Highlight can additionally be used to provide styling of
615 source code snippets. See the "set style" commands, below, for more
618 * Removed support for old demangling styles arm, edg, gnu, hp and
623 set debug compile-cplus-types
624 show debug compile-cplus-types
625 Control the display of debug output about type conversion in the
626 C++ compile feature. Commands have no effect while compiliong
631 Control whether debug output about files/functions skipping is
634 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
635 Apply a command to some frames.
636 FLAG arguments allow to control what output to produce and how to handle
637 errors raised when applying COMMAND to a frame.
640 Apply a command to all threads (ignoring errors and empty output).
641 Shortcut for 'thread apply all -s COMMAND'.
644 Apply a command to all frames (ignoring errors and empty output).
645 Shortcut for 'frame apply all -s COMMAND'.
648 Apply a command to all frames of all threads (ignoring errors and empty
650 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
652 maint set dwarf unwinders (on|off)
653 maint show dwarf unwinders
654 Control whether DWARF unwinders can be used.
657 Display a list of open files for a process.
661 Changes to the "frame", "select-frame", and "info frame" CLI commands.
662 These commands all now take a frame specification which
663 is either a frame level, or one of the keywords 'level', 'address',
664 'function', or 'view' followed by a parameter. Selecting a frame by
665 address, or viewing a frame outside the current backtrace now
666 requires the use of a keyword. Selecting a frame by level is
667 unchanged. The MI comment "-stack-select-frame" is unchanged.
669 target remote FILENAME
670 target extended-remote FILENAME
671 If FILENAME is a Unix domain socket, GDB will attempt to connect
672 to this socket instead of opening FILENAME as a character device.
674 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
675 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
676 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
677 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
678 These commands can now print only the searched entities
679 matching the provided regexp(s), giving a condition
680 on the entity names or entity types. The flag -q disables
681 printing headers or informations messages.
687 These commands now determine the syntax for the shown entities
688 according to the language chosen by `set language'. In particular,
689 `set language auto' means to automatically choose the language of
692 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
693 The 'thread apply' command accepts new FLAG arguments.
694 FLAG arguments allow to control what output to produce and how to handle
695 errors raised when applying COMMAND to a thread.
697 set tui tab-width NCHARS
698 show tui tab-width NCHARS
699 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
701 set style enabled [on|off]
703 Enable or disable terminal styling. Styling is enabled by default
704 on most hosts, but disabled by default when in batch mode.
706 set style sources [on|off]
708 Enable or disable source code styling. Source code styling is
709 enabled by default, but only takes effect if styling in general is
710 enabled, and if GDB was linked with GNU Source Highlight.
712 set style filename foreground COLOR
713 set style filename background COLOR
714 set style filename intensity VALUE
715 Control the styling of file names.
717 set style function foreground COLOR
718 set style function background COLOR
719 set style function intensity VALUE
720 Control the styling of function names.
722 set style variable foreground COLOR
723 set style variable background COLOR
724 set style variable intensity VALUE
725 Control the styling of variable names.
727 set style address foreground COLOR
728 set style address background COLOR
729 set style address intensity VALUE
730 Control the styling of addresses.
734 ** The '-data-disassemble' MI command now accepts an '-a' option to
735 disassemble the whole function surrounding the given program
736 counter value or function name. Support for this feature can be
737 verified by using the "-list-features" command, which should
738 contain "data-disassemble-a-option".
740 ** Command responses and notifications that include a frame now include
741 the frame's architecture in a new "arch" attribute.
743 * New native configurations
745 GNU/Linux/RISC-V riscv*-*-linux*
746 FreeBSD/riscv riscv*-*-freebsd*
750 GNU/Linux/RISC-V riscv*-*-linux*
752 CSKY GNU/LINUX csky*-*-linux
753 FreeBSD/riscv riscv*-*-freebsd*
755 GNU/Linux/OpenRISC or1k*-*-linux*
759 GDB no longer supports native debugging on versions of MS-Windows
764 ** GDB no longer supports Python versions less than 2.6.
766 ** The gdb.Inferior type has a new 'progspace' property, which is the program
767 space associated to that inferior.
769 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
770 of objfiles associated to that program space.
772 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
773 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
776 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
777 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
778 correct and did not work properly.
780 ** The gdb.Value type has a new constructor, which is used to construct a
781 gdb.Value from a Python buffer object and a gdb.Type.
787 Enable or disable the undefined behavior sanitizer. This is
788 disabled by default, but passing --enable-ubsan=yes or
789 --enable-ubsan=auto to configure will enable it. Enabling this can
790 cause a performance penalty. The undefined behavior sanitizer was
791 first introduced in GCC 4.9.
793 *** Changes in GDB 8.2
795 * The 'set disassembler-options' command now supports specifying options
798 * The 'symbol-file' command now accepts an '-o' option to add a relative
799 offset to all sections.
801 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
802 a relative offset to all sections, but it allows to override the load
803 address of individual sections using '-s'.
805 * The 'add-symbol-file' command no longer requires the second argument
806 (address of the text section).
808 * The endianness used with the 'set endian auto' mode in the absence of
809 an executable selected for debugging is now the last endianness chosen
810 either by one of the 'set endian big' and 'set endian little' commands
811 or by inferring from the last executable used, rather than the startup
814 * The pager now allows a "c" response, meaning to disable the pager
815 for the rest of the current command.
817 * The commands 'info variables/functions/types' now show the source line
818 numbers of symbol definitions when available.
820 * 'info proc' now works on running processes on FreeBSD systems and core
821 files created on FreeBSD systems.
823 * C expressions can now use _Alignof, and C++ expressions can now use
826 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
827 the vector length while the process is running.
833 Control display of debugging info regarding the FreeBSD native target.
835 set|show varsize-limit
836 This new setting allows the user to control the maximum size of Ada
837 objects being printed when those objects have a variable type,
838 instead of that maximum size being hardcoded to 65536 bytes.
840 set|show record btrace cpu
841 Controls the processor to be used for enabling errata workarounds for
844 maint check libthread-db
845 Run integrity checks on the current inferior's thread debugging
848 maint set check-libthread-db (on|off)
849 maint show check-libthread-db
850 Control whether to run integrity checks on inferior specific thread
851 debugging libraries as they are loaded. The default is not to
856 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
858 ** The commands attached to a breakpoint can be set by assigning to
859 the breakpoint's "commands" field.
861 ** gdb.execute can now execute multi-line gdb commands.
863 ** The new functions gdb.convenience_variable and
864 gdb.set_convenience_variable can be used to get and set the value
865 of convenience variables.
867 ** A gdb.Parameter will no longer print the "set" help text on an
868 ordinary "set"; instead by default a "set" will be silent unless
869 the get_set_string method returns a non-empty string.
873 RiscV ELF riscv*-*-elf
875 * Removed targets and native configurations
877 m88k running OpenBSD m88*-*-openbsd*
878 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
879 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
880 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
882 * Aarch64/Linux hardware watchpoints improvements
884 Hardware watchpoints on unaligned addresses are now properly
885 supported when running Linux kernel 4.10 or higher: read and access
886 watchpoints are no longer spuriously missed, and all watchpoints
887 lengths between 1 and 8 bytes are supported. On older kernels,
888 watchpoints set on unaligned addresses are no longer missed, with
889 the tradeoff that there is a possibility of false hits being
894 --enable-codesign=CERT
895 This can be used to invoke "codesign -s CERT" after building gdb.
896 This option is useful on macOS, where code signing is required for
897 gdb to work properly.
899 --disable-gdbcli has been removed
900 This is now silently accepted, but does nothing.
902 *** Changes in GDB 8.1
904 * GDB now supports dynamically creating arbitrary register groups specified
905 in XML target descriptions. This allows for finer grain grouping of
906 registers on systems with a large amount of registers.
908 * The 'ptype' command now accepts a '/o' flag, which prints the
909 offsets and sizes of fields in a struct, like the pahole(1) tool.
911 * New "--readnever" command line option instructs GDB to not read each
912 symbol file's symbolic debug information. This makes startup faster
913 but at the expense of not being able to perform symbolic debugging.
914 This option is intended for use cases where symbolic debugging will
915 not be used, e.g., when you only need to dump the debuggee's core.
917 * GDB now uses the GNU MPFR library, if available, to emulate target
918 floating-point arithmetic during expression evaluation when the target
919 uses different floating-point formats than the host. At least version
920 3.1 of GNU MPFR is required.
922 * GDB now supports access to the guarded-storage-control registers and the
923 software-based guarded-storage broadcast control registers on IBM z14.
925 * On Unix systems, GDB now supports transmitting environment variables
926 that are to be set or unset to GDBserver. These variables will
927 affect the environment to be passed to the remote inferior.
929 To inform GDB of environment variables that are to be transmitted to
930 GDBserver, use the "set environment" command. Only user set
931 environment variables are sent to GDBserver.
933 To inform GDB of environment variables that are to be unset before
934 the remote inferior is started by the GDBserver, use the "unset
935 environment" command.
937 * Completion improvements
939 ** GDB can now complete function parameters in linespecs and
940 explicit locations without quoting. When setting breakpoints,
941 quoting around functions names to help with TAB-completion is
942 generally no longer necessary. For example, this now completes
945 (gdb) b function(in[TAB]
946 (gdb) b function(int)
948 Related, GDB is no longer confused with completing functions in
949 C++ anonymous namespaces:
952 (gdb) b (anonymous namespace)::[TAB][TAB]
953 (anonymous namespace)::a_function()
954 (anonymous namespace)::b_function()
956 ** GDB now has much improved linespec and explicit locations TAB
957 completion support, that better understands what you're
958 completing and offers better suggestions. For example, GDB no
959 longer offers data symbols as possible completions when you're
960 setting a breakpoint.
962 ** GDB now TAB-completes label symbol names.
964 ** The "complete" command now mimics TAB completion accurately.
966 * New command line options (gcore)
969 Dump all memory mappings.
971 * Breakpoints on C++ functions are now set on all scopes by default
973 By default, breakpoints on functions/methods are now interpreted as
974 specifying all functions with the given name ignoring missing
975 leading scopes (namespaces and classes).
977 For example, assuming a C++ program with symbols named:
982 both commands "break func()" and "break B::func()" set a breakpoint
985 You can use the new flag "-qualified" to override this. This makes
986 GDB interpret the specified function name as a complete
987 fully-qualified name instead. For example, using the same C++
988 program, the "break -q B::func" command sets a breakpoint on
989 "B::func", only. A parameter has been added to the Python
990 gdb.Breakpoint constructor to achieve the same result when creating
991 a breakpoint from Python.
993 * Breakpoints on functions marked with C++ ABI tags
995 GDB can now set breakpoints on functions marked with C++ ABI tags
996 (e.g., [abi:cxx11]). See here for a description of ABI tags:
997 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
999 Functions with a C++11 abi tag are demangled/displayed like this:
1001 function[abi:cxx11](int)
1004 You can now set a breakpoint on such functions simply as if they had
1007 (gdb) b function(int)
1009 Or if you need to disambiguate between tags, like:
1011 (gdb) b function[abi:other_tag](int)
1013 Tab completion was adjusted accordingly as well.
1017 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1018 gdb.new_thread are emitted. See the manual for further
1019 description of these.
1021 ** A new function, "gdb.rbreak" has been added to the Python API.
1022 This function allows the setting of a large number of breakpoints
1023 via a regex pattern in Python. See the manual for further details.
1025 ** Python breakpoints can now accept explicit locations. See the
1026 manual for a further description of this feature.
1029 * New features in the GDB remote stub, GDBserver
1031 ** GDBserver is now able to start inferior processes with a
1032 specified initial working directory.
1034 The user can set the desired working directory to be used from
1035 GDB using the new "set cwd" command.
1037 ** New "--selftest" command line option runs some GDBserver self
1038 tests. These self tests are disabled in releases.
1040 ** On Unix systems, GDBserver now does globbing expansion and variable
1041 substitution in inferior command line arguments.
1043 This is done by starting inferiors using a shell, like GDB does.
1044 See "set startup-with-shell" in the user manual for how to disable
1045 this from GDB when using "target extended-remote". When using
1046 "target remote", you can disable the startup with shell by using the
1047 new "--no-startup-with-shell" GDBserver command line option.
1049 ** On Unix systems, GDBserver now supports receiving environment
1050 variables that are to be set or unset from GDB. These variables
1051 will affect the environment to be passed to the inferior.
1053 * When catching an Ada exception raised with a message, GDB now prints
1054 the message in the catchpoint hit notification. In GDB/MI mode, that
1055 information is provided as an extra field named "exception-message"
1056 in the *stopped notification.
1058 * Trait objects can now be inspected When debugging Rust code. This
1059 requires compiler support which will appear in Rust 1.24.
1061 * New remote packets
1063 QEnvironmentHexEncoded
1064 Inform GDBserver of an environment variable that is to be passed to
1065 the inferior when starting it.
1068 Inform GDBserver of an environment variable that is to be unset
1069 before starting the remote inferior.
1072 Inform GDBserver that the environment should be reset (i.e.,
1073 user-set environment variables should be unset).
1076 Indicates whether the inferior must be started with a shell or not.
1079 Tell GDBserver that the inferior to be started should use a specific
1082 * The "maintenance print c-tdesc" command now takes an optional
1083 argument which is the file name of XML target description.
1085 * The "maintenance selftest" command now takes an optional argument to
1086 filter the tests to be run.
1088 * The "enable", and "disable" commands now accept a range of
1089 breakpoint locations, e.g. "enable 1.3-5".
1094 Set and show the current working directory for the inferior.
1096 set|show compile-gcc
1097 Set and show compilation command used for compiling and injecting code
1098 with the 'compile' commands.
1100 set debug separate-debug-file
1101 show debug separate-debug-file
1102 Control the display of debug output about separate debug file search.
1104 set dump-excluded-mappings
1105 show dump-excluded-mappings
1106 Control whether mappings marked with the VM_DONTDUMP flag should be
1107 dumped when generating a core file.
1109 maint info selftests
1110 List the registered selftests.
1113 Start the debugged program stopping at the first instruction.
1116 Control display of debugging messages related to OpenRISC targets.
1118 set|show print type nested-type-limit
1119 Set and show the limit of nesting level for nested types that the
1120 type printer will show.
1122 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1125 * Safer/improved support for debugging with no debug info
1127 GDB no longer assumes functions with no debug information return
1130 This means that GDB now refuses to call such functions unless you
1131 tell it the function's type, by either casting the call to the
1132 declared return type, or by casting the function to a function
1133 pointer of the right type, and calling that:
1135 (gdb) p getenv ("PATH")
1136 'getenv' has unknown return type; cast the call to its declared return type
1137 (gdb) p (char *) getenv ("PATH")
1138 $1 = 0x7fffffffe "/usr/local/bin:/"...
1139 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1140 $2 = 0x7fffffffe "/usr/local/bin:/"...
1142 Similarly, GDB no longer assumes that global variables with no debug
1143 info have type 'int', and refuses to print the variable's value
1144 unless you tell it the variable's type:
1147 'var' has unknown type; cast it to its declared type
1151 * New native configurations
1153 FreeBSD/aarch64 aarch64*-*-freebsd*
1154 FreeBSD/arm arm*-*-freebsd*
1158 FreeBSD/aarch64 aarch64*-*-freebsd*
1159 FreeBSD/arm arm*-*-freebsd*
1160 OpenRISC ELF or1k*-*-elf
1162 * Removed targets and native configurations
1164 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1166 *** Changes in GDB 8.0
1168 * GDB now supports access to the PKU register on GNU/Linux. The register is
1169 added by the Memory Protection Keys for Userspace feature which will be
1170 available in future Intel CPUs.
1172 * GDB now supports C++11 rvalue references.
1176 ** New functions to start, stop and access a running btrace recording.
1177 ** Rvalue references are now supported in gdb.Type.
1179 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1182 * Building GDB and GDBserver now requires a C++11 compiler.
1184 For example, GCC 4.8 or later.
1186 It is no longer possible to build GDB or GDBserver with a C
1187 compiler. The --disable-build-with-cxx configure option has been
1190 * Building GDB and GDBserver now requires GNU make >= 3.81.
1192 It is no longer supported to build GDB or GDBserver with another
1193 implementation of the make program or an earlier version of GNU make.
1195 * Native debugging on MS-Windows supports command-line redirection
1197 Command-line arguments used for starting programs on MS-Windows can
1198 now include redirection symbols supported by native Windows shells,
1199 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1200 as "run", "start", and "set args", as well as the corresponding MI
1203 * Support for thread names on MS-Windows.
1205 GDB now catches and handles the special exception that programs
1206 running on MS-Windows use to assign names to threads in the
1209 * Support for Java programs compiled with gcj has been removed.
1211 * User commands now accept an unlimited number of arguments.
1212 Previously, only up to 10 was accepted.
1214 * The "eval" command now expands user-defined command arguments.
1216 This makes it easier to process a variable number of arguments:
1221 eval "print $arg%d", $i
1226 * Target descriptions can now describe registers for sparc32 and sparc64.
1228 * GDB now supports DWARF version 5 (debug information format).
1229 Its .debug_names index is not yet supported.
1231 * New native configurations
1233 FreeBSD/mips mips*-*-freebsd
1237 Synopsys ARC arc*-*-elf32
1238 FreeBSD/mips mips*-*-freebsd
1240 * Removed targets and native configurations
1242 Alpha running FreeBSD alpha*-*-freebsd*
1243 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1248 Erases all the flash memory regions reported by the target.
1250 maint print arc arc-instruction address
1251 Print internal disassembler information about instruction at a given address.
1255 set disassembler-options
1256 show disassembler-options
1257 Controls the passing of target specific information to the disassembler.
1258 If it is necessary to specify more than one disassembler option then
1259 multiple options can be placed together into a comma separated list.
1260 The default value is the empty string. Currently, the only supported
1261 targets are ARM, PowerPC and S/390.
1266 Erases all the flash memory regions reported by the target. This is
1267 equivalent to the CLI command flash-erase.
1269 -file-list-shared-libraries
1270 List the shared libraries in the program. This is
1271 equivalent to the CLI command "info shared".
1274 Catchpoints stopping the program when Ada exceptions are
1275 handled. This is equivalent to the CLI command "catch handlers".
1277 *** Changes in GDB 7.12
1279 * GDB and GDBserver now build with a C++ compiler by default.
1281 The --enable-build-with-cxx configure option is now enabled by
1282 default. One must now explicitly configure with
1283 --disable-build-with-cxx in order to build with a C compiler. This
1284 option will be removed in a future release.
1286 * GDBserver now supports recording btrace without maintaining an active
1289 * GDB now supports a negative repeat count in the 'x' command to examine
1290 memory backward from the given address. For example:
1293 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1294 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1295 (gdb) x/-5i 0x0000000000400580
1296 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1297 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1298 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1299 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1300 0x40057b <main(int, char**)+25>:
1301 callq 0x400536 <Func1(int, char const*)>
1303 * Fortran: Support structures with fields of dynamic types and
1304 arrays of dynamic types.
1306 * The symbol dumping maintenance commands have new syntax.
1307 maint print symbols [-pc address] [--] [filename]
1308 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1309 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1310 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1311 maint print msymbols [-objfile objfile] [--] [filename]
1313 * GDB now supports multibit bitfields and enums in target register
1316 * New Python-based convenience function $_as_string(val), which returns
1317 the textual representation of a value. This function is especially
1318 useful to obtain the text label of an enum value.
1320 * Intel MPX bound violation handling.
1322 Segmentation faults caused by a Intel MPX boundary violation
1323 now display the kind of violation (upper or lower), the memory
1324 address accessed and the memory bounds, along with the usual
1325 signal received and code location.
1329 Program received signal SIGSEGV, Segmentation fault
1330 Upper bound violation while accessing address 0x7fffffffc3b3
1331 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1332 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1334 * Rust language support.
1335 GDB now supports debugging programs written in the Rust programming
1336 language. See https://www.rust-lang.org/ for more information about
1339 * Support for running interpreters on specified input/output devices
1341 GDB now supports a new mechanism that allows frontends to provide
1342 fully featured GDB console views, as a better alternative to
1343 building such views on top of the "-interpreter-exec console"
1344 command. See the new "new-ui" command below. With that command,
1345 frontends can now start GDB in the traditional command-line mode
1346 running in an embedded terminal emulator widget, and create a
1347 separate MI interpreter running on a specified i/o device. In this
1348 way, GDB handles line editing, history, tab completion, etc. in the
1349 console all by itself, and the GUI uses the separate MI interpreter
1350 for its own control and synchronization, invisible to the command
1353 * The "catch syscall" command catches groups of related syscalls.
1355 The "catch syscall" command now supports catching a group of related
1356 syscalls using the 'group:' or 'g:' prefix.
1361 skip -gfile file-glob-pattern
1362 skip -function function
1363 skip -rfunction regular-expression
1364 A generalized form of the skip command, with new support for
1365 glob-style file names and regular expressions for function names.
1366 Additionally, a file spec and a function spec may now be combined.
1368 maint info line-table REGEXP
1369 Display the contents of GDB's internal line table data struture.
1372 Run any GDB unit tests that were compiled in.
1375 Start a new user interface instance running INTERP as interpreter,
1376 using the TTY file for input/output.
1380 ** gdb.Breakpoint objects have a new attribute "pending", which
1381 indicates whether the breakpoint is pending.
1382 ** Three new breakpoint-related events have been added:
1383 gdb.breakpoint_created, gdb.breakpoint_modified, and
1384 gdb.breakpoint_deleted.
1386 signal-event EVENTID
1387 Signal ("set") the given MS-Windows event object. This is used in
1388 conjunction with the Windows JIT debugging (AeDebug) support, where
1389 the OS suspends a crashing process until a debugger can attach to
1390 it. Resuming the crashing process, in order to debug it, is done by
1391 signalling an event.
1393 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1394 was added in GDBserver, including JIT compiling fast tracepoint's
1395 conditional expression bytecode into native code.
1397 * Support for various remote target protocols and ROM monitors has
1400 target m32rsdi Remote M32R debugging over SDI
1401 target mips MIPS remote debugging protocol
1402 target pmon PMON ROM monitor
1403 target ddb NEC's DDB variant of PMON for Vr4300
1404 target rockhopper NEC RockHopper variant of PMON
1405 target lsi LSI variant of PMO
1407 * Support for tracepoints and fast tracepoints on powerpc-linux,
1408 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1409 including JIT compiling fast tracepoint's conditional expression
1410 bytecode into native code.
1412 * MI async record =record-started now includes the method and format used for
1413 recording. For example:
1415 =record-started,thread-group="i1",method="btrace",format="bts"
1417 * MI async record =thread-selected now includes the frame field. For example:
1419 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1423 Andes NDS32 nds32*-*-elf
1425 *** Changes in GDB 7.11
1427 * GDB now supports debugging kernel-based threads on FreeBSD.
1429 * Per-inferior thread numbers
1431 Thread numbers are now per inferior instead of global. If you're
1432 debugging multiple inferiors, GDB displays thread IDs using a
1433 qualified INF_NUM.THR_NUM form. For example:
1437 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1438 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1439 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1440 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1442 As consequence, thread numbers as visible in the $_thread
1443 convenience variable and in Python's InferiorThread.num attribute
1444 are no longer unique between inferiors.
1446 GDB now maintains a second thread ID per thread, referred to as the
1447 global thread ID, which is the new equivalent of thread numbers in
1448 previous releases. See also $_gthread below.
1450 For backwards compatibility, MI's thread IDs always refer to global
1453 * Commands that accept thread IDs now accept the qualified
1454 INF_NUM.THR_NUM form as well. For example:
1457 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1460 * In commands that accept a list of thread IDs, you can now refer to
1461 all threads of an inferior using a star wildcard. GDB accepts
1462 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1463 refer to all threads of the current inferior. For example, "info
1466 * You can use "info threads -gid" to display the global thread ID of
1469 * The new convenience variable $_gthread holds the global number of
1472 * The new convenience variable $_inferior holds the number of the
1475 * GDB now displays the ID and name of the thread that hit a breakpoint
1476 or received a signal, if your program is multi-threaded. For
1479 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1480 Thread 1 "main" received signal SIGINT, Interrupt.
1482 * Record btrace now supports non-stop mode.
1484 * Support for tracepoints on aarch64-linux was added in GDBserver.
1486 * The 'record instruction-history' command now indicates speculative execution
1487 when using the Intel Processor Trace recording format.
1489 * GDB now allows users to specify explicit locations, bypassing
1490 the linespec parser. This feature is also available to GDB/MI
1493 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1494 GDB now is able to debug both AArch64 applications and ARM applications
1497 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1498 including JIT compiling fast tracepoint's conditional expression bytecode
1501 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1503 * "info threads", "info inferiors", "info display", "info checkpoints"
1504 and "maint info program-spaces" now list the corresponding items in
1505 ascending ID order, for consistency with all other "info" commands.
1507 * In Ada, the overloads selection menu has been enhanced to display the
1508 parameter types and the return types for the matching overloaded subprograms.
1512 maint set target-non-stop (on|off|auto)
1513 maint show target-non-stop
1514 Control whether GDB targets always operate in non-stop mode even if
1515 "set non-stop" is "off". The default is "auto", meaning non-stop
1516 mode is enabled if supported by the target.
1518 maint set bfd-sharing
1519 maint show bfd-sharing
1520 Control the reuse of bfd objects.
1523 show debug bfd-cache
1524 Control display of debugging info regarding bfd caching.
1528 Control display of debugging info regarding FreeBSD threads.
1530 set remote multiprocess-extensions-packet
1531 show remote multiprocess-extensions-packet
1532 Set/show the use of the remote protocol multiprocess extensions.
1534 set remote thread-events
1535 show remote thread-events
1536 Set/show the use of thread create/exit events.
1538 set ada print-signatures on|off
1539 show ada print-signatures"
1540 Control whether parameter types and return types are displayed in overloads
1541 selection menus. It is activaled (@code{on}) by default.
1545 Controls the maximum size of memory, in bytes, that GDB will
1546 allocate for value contents. Prevents incorrect programs from
1547 causing GDB to allocate overly large buffers. Default is 64k.
1549 * The "disassemble" command accepts a new modifier: /s.
1550 It prints mixed source+disassembly like /m with two differences:
1551 - disassembled instructions are now printed in program order, and
1552 - and source for all relevant files is now printed.
1553 The "/m" option is now considered deprecated: its "source-centric"
1554 output hasn't proved useful in practice.
1556 * The "record instruction-history" command accepts a new modifier: /s.
1557 It behaves exactly like /m and prints mixed source+disassembly.
1559 * The "set scheduler-locking" command supports a new mode "replay".
1560 It behaves like "off" in record mode and like "on" in replay mode.
1562 * Support for various ROM monitors has been removed:
1564 target dbug dBUG ROM monitor for Motorola ColdFire
1565 target picobug Motorola picobug monitor
1566 target dink32 DINK32 ROM monitor for PowerPC
1567 target m32r Renesas M32R/D ROM monitor
1568 target mon2000 mon2000 ROM monitor
1569 target ppcbug PPCBUG ROM monitor for PowerPC
1571 * Support for reading/writing memory and extracting values on architectures
1572 whose memory is addressable in units of any integral multiple of 8 bits.
1575 Allows to break when an Ada exception is handled.
1577 * New remote packets
1580 Indicates that an exec system call was executed.
1582 exec-events feature in qSupported
1583 The qSupported packet allows GDB to request support for exec
1584 events using the new 'gdbfeature' exec-event, and the qSupported
1585 response can contain the corresponding 'stubfeature'. Set and
1586 show commands can be used to display whether these features are enabled.
1589 Equivalent to interrupting with the ^C character, but works in
1592 thread created stop reason (T05 create:...)
1593 Indicates that the thread was just created and is stopped at entry.
1595 thread exit stop reply (w exitcode;tid)
1596 Indicates that the thread has terminated.
1599 Enables/disables thread create and exit event reporting. For
1600 example, this is used in non-stop mode when GDB stops a set of
1601 threads and synchronously waits for the their corresponding stop
1602 replies. Without exit events, if one of the threads exits, GDB
1603 would hang forever not knowing that it should no longer expect a
1604 stop for that same thread.
1607 Indicates that there are no resumed threads left in the target (all
1608 threads are stopped). The remote stub reports support for this stop
1609 reply to GDB's qSupported query.
1612 Enables/disables catching syscalls from the inferior process.
1613 The remote stub reports support for this packet to GDB's qSupported query.
1615 syscall_entry stop reason
1616 Indicates that a syscall was just called.
1618 syscall_return stop reason
1619 Indicates that a syscall just returned.
1621 * Extended-remote exec events
1623 ** GDB now has support for exec events on extended-remote Linux targets.
1624 For such targets with Linux kernels 2.5.46 and later, this enables
1625 follow-exec-mode and exec catchpoints.
1627 set remote exec-event-feature-packet
1628 show remote exec-event-feature-packet
1629 Set/show the use of the remote exec event feature.
1631 * Thread names in remote protocol
1633 The reply to qXfer:threads:read may now include a name attribute for each
1636 * Target remote mode fork and exec events
1638 ** GDB now has support for fork and exec events on target remote mode
1639 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1640 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1641 fork and exec catchpoints.
1643 * Remote syscall events
1645 ** GDB now has support for catch syscall on remote Linux targets,
1646 currently enabled on x86/x86_64 architectures.
1648 set remote catch-syscall-packet
1649 show remote catch-syscall-packet
1650 Set/show the use of the remote catch syscall feature.
1654 ** The -var-set-format command now accepts the zero-hexadecimal
1655 format. It outputs data in hexadecimal format with zero-padding on the
1660 ** gdb.InferiorThread objects have a new attribute "global_num",
1661 which refers to the thread's global thread ID. The existing
1662 "num" attribute now refers to the thread's per-inferior number.
1663 See "Per-inferior thread numbers" above.
1664 ** gdb.InferiorThread objects have a new attribute "inferior", which
1665 is the Inferior object the thread belongs to.
1667 *** Changes in GDB 7.10
1669 * Support for process record-replay and reverse debugging on aarch64*-linux*
1670 targets has been added. GDB now supports recording of A64 instruction set
1671 including advance SIMD instructions.
1673 * Support for Sun's version of the "stabs" debug file format has been removed.
1675 * GDB now honors the content of the file /proc/PID/coredump_filter
1676 (PID is the process ID) on GNU/Linux systems. This file can be used
1677 to specify the types of memory mappings that will be included in a
1678 corefile. For more information, please refer to the manual page of
1679 "core(5)". GDB also has a new command: "set use-coredump-filter
1680 on|off". It allows to set whether GDB will read the content of the
1681 /proc/PID/coredump_filter file when generating a corefile.
1683 * The "info os" command on GNU/Linux can now display information on
1685 "info os cpus" Listing of all cpus/cores on the system
1687 * GDB has two new commands: "set serial parity odd|even|none" and
1688 "show serial parity". These allows to set or show parity for the
1691 * The "info source" command now displays the producer string if it was
1692 present in the debug info. This typically includes the compiler version
1693 and may include things like its command line arguments.
1695 * The "info dll", an alias of the "info sharedlibrary" command,
1696 is now available on all platforms.
1698 * Directory names supplied to the "set sysroot" commands may be
1699 prefixed with "target:" to tell GDB to access shared libraries from
1700 the target system, be it local or remote. This replaces the prefix
1701 "remote:". The default sysroot has been changed from "" to
1702 "target:". "remote:" is automatically converted to "target:" for
1703 backward compatibility.
1705 * The system root specified by "set sysroot" will be prepended to the
1706 filename of the main executable (if reported to GDB as absolute by
1707 the operating system) when starting processes remotely, and when
1708 attaching to already-running local or remote processes.
1710 * GDB now supports automatic location and retrieval of executable
1711 files from remote targets. Remote debugging can now be initiated
1712 using only a "target remote" or "target extended-remote" command
1713 (no "set sysroot" or "file" commands are required). See "New remote
1716 * The "dump" command now supports verilog hex format.
1718 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1720 * On GNU/Linux, GDB and gdbserver are now able to access executable
1721 and shared library files without a "set sysroot" command when
1722 attaching to processes running in different mount namespaces from
1723 the debugger. This makes it possible to attach to processes in
1724 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1725 See "New remote packets" below.
1727 * The "tui reg" command now provides completion for all of the
1728 available register groups, including target specific groups.
1730 * The HISTSIZE environment variable is no longer read when determining
1731 the size of GDB's command history. GDB now instead reads the dedicated
1732 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1733 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1738 ** Memory ports can now be unbuffered.
1742 ** gdb.Objfile objects have a new attribute "username",
1743 which is the name of the objfile as specified by the user,
1744 without, for example, resolving symlinks.
1745 ** You can now write frame unwinders in Python.
1746 ** gdb.Type objects have a new method "optimized_out",
1747 returning optimized out gdb.Value instance of this type.
1748 ** gdb.Value objects have new methods "reference_value" and
1749 "const_value" which return a reference to the value and a
1750 "const" version of the value respectively.
1754 maint print symbol-cache
1755 Print the contents of the symbol cache.
1757 maint print symbol-cache-statistics
1758 Print statistics of symbol cache usage.
1760 maint flush-symbol-cache
1761 Flush the contents of the symbol cache.
1765 Start branch trace recording using Branch Trace Store (BTS) format.
1768 Evaluate expression by using the compiler and print result.
1772 Explicit commands for enabling and disabling tui mode.
1775 set mpx bound on i386 and amd64
1776 Support for bound table investigation on Intel MPX enabled applications.
1780 Start branch trace recording using Intel Processor Trace format.
1783 Print information about branch tracing internals.
1785 maint btrace packet-history
1786 Print the raw branch tracing data.
1788 maint btrace clear-packet-history
1789 Discard the stored raw branch tracing data.
1792 Discard all branch tracing data. It will be fetched and processed
1793 anew by the next "record" command.
1798 Renamed from "set debug dwarf2-die".
1799 show debug dwarf-die
1800 Renamed from "show debug dwarf2-die".
1802 set debug dwarf-read
1803 Renamed from "set debug dwarf2-read".
1804 show debug dwarf-read
1805 Renamed from "show debug dwarf2-read".
1807 maint set dwarf always-disassemble
1808 Renamed from "maint set dwarf2 always-disassemble".
1809 maint show dwarf always-disassemble
1810 Renamed from "maint show dwarf2 always-disassemble".
1812 maint set dwarf max-cache-age
1813 Renamed from "maint set dwarf2 max-cache-age".
1814 maint show dwarf max-cache-age
1815 Renamed from "maint show dwarf2 max-cache-age".
1817 set debug dwarf-line
1818 show debug dwarf-line
1819 Control display of debugging info regarding DWARF line processing.
1822 show max-completions
1823 Set the maximum number of candidates to be considered during
1824 completion. The default value is 200. This limit allows GDB
1825 to avoid generating large completion lists, the computation of
1826 which can cause the debugger to become temporarily unresponsive.
1828 set history remove-duplicates
1829 show history remove-duplicates
1830 Control the removal of duplicate history entries.
1832 maint set symbol-cache-size
1833 maint show symbol-cache-size
1834 Control the size of the symbol cache.
1836 set|show record btrace bts buffer-size
1837 Set and show the size of the ring buffer used for branch tracing in
1839 The obtained size may differ from the requested size. Use "info
1840 record" to see the obtained buffer size.
1842 set debug linux-namespaces
1843 show debug linux-namespaces
1844 Control display of debugging info regarding Linux namespaces.
1846 set|show record btrace pt buffer-size
1847 Set and show the size of the ring buffer used for branch tracing in
1848 Intel Processor Trace format.
1849 The obtained size may differ from the requested size. Use "info
1850 record" to see the obtained buffer size.
1852 maint set|show btrace pt skip-pad
1853 Set and show whether PAD packets are skipped when computing the
1856 * The command 'thread apply all' can now support new option '-ascending'
1857 to call its specified command for all threads in ascending order.
1859 * Python/Guile scripting
1861 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1862 special section named `.debug_gdb_scripts'.
1864 * New remote packets
1866 qXfer:btrace-conf:read
1867 Return the branch trace configuration for the current thread.
1869 Qbtrace-conf:bts:size
1870 Set the requested ring buffer size for branch tracing in BTS format.
1873 Enable Intel Procesor Trace-based branch tracing for the current
1874 process. The remote stub reports support for this packet to GDB's
1877 Qbtrace-conf:pt:size
1878 Set the requested ring buffer size for branch tracing in Intel Processor
1882 Indicates a memory breakpoint instruction was executed, irrespective
1883 of whether it was GDB that planted the breakpoint or the breakpoint
1884 is hardcoded in the program. This is required for correct non-stop
1888 Indicates the target stopped for a hardware breakpoint. This is
1889 required for correct non-stop mode operation.
1892 Return information about files on the remote system.
1894 qXfer:exec-file:read
1895 Return the full absolute name of the file that was executed to
1896 create a process running on the remote system.
1899 Select the filesystem on which vFile: operations with filename
1900 arguments will operate. This is required for GDB to be able to
1901 access files on remote targets where the remote stub does not
1902 share a common filesystem with the inferior(s).
1905 Indicates that a fork system call was executed.
1908 Indicates that a vfork system call was executed.
1910 vforkdone stop reason
1911 Indicates that a vfork child of the specified process has executed
1912 an exec or exit, allowing the vfork parent to resume execution.
1914 fork-events and vfork-events features in qSupported
1915 The qSupported packet allows GDB to request support for fork and
1916 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1917 and the qSupported response can contain the corresponding
1918 'stubfeatures'. Set and show commands can be used to display
1919 whether these features are enabled.
1921 * Extended-remote fork events
1923 ** GDB now has support for fork events on extended-remote Linux
1924 targets. For targets with Linux kernels 2.5.60 and later, this
1925 enables follow-fork-mode and detach-on-fork for both fork and
1926 vfork, as well as fork and vfork catchpoints.
1928 * The info record command now shows the recording format and the
1929 branch tracing configuration for the current thread when using
1930 the btrace record target.
1931 For the BTS format, it shows the ring buffer size.
1933 * GDB now has support for DTrace USDT (Userland Static Defined
1934 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1936 * GDB now supports access to vector registers on S/390 GNU/Linux
1939 * Removed command line options
1941 -xdb HP-UX XDB compatibility mode.
1943 * Removed targets and native configurations
1945 HP/PA running HP-UX hppa*-*-hpux*
1946 Itanium running HP-UX ia64-*-hpux*
1948 * New configure options
1951 This configure option allows the user to build GDB with support for
1952 Intel Processor Trace (default: auto). This requires libipt.
1954 --with-libipt-prefix=PATH
1955 Specify the path to the version of libipt that GDB should use.
1956 $PATH/include should contain the intel-pt.h header and
1957 $PATH/lib should contain the libipt.so library.
1959 *** Changes in GDB 7.9.1
1963 ** Xmethods can now specify a result type.
1965 *** Changes in GDB 7.9
1967 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1971 ** You can now access frame registers from Python scripts.
1972 ** New attribute 'producer' for gdb.Symtab objects.
1973 ** gdb.Objfile objects have a new attribute "progspace",
1974 which is the gdb.Progspace object of the containing program space.
1975 ** gdb.Objfile objects have a new attribute "owner".
1976 ** gdb.Objfile objects have a new attribute "build_id",
1977 which is the build ID generated when the file was built.
1978 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1979 ** A new event "gdb.clear_objfiles" has been added, triggered when
1980 selecting a new file to debug.
1981 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1982 ** New function gdb.lookup_objfile.
1984 New events which are triggered when GDB modifies the state of the
1987 ** gdb.events.inferior_call_pre: Function call is about to be made.
1988 ** gdb.events.inferior_call_post: Function call has just been made.
1989 ** gdb.events.memory_changed: A memory location has been altered.
1990 ** gdb.events.register_changed: A register has been altered.
1992 * New Python-based convenience functions:
1994 ** $_caller_is(name [, number_of_frames])
1995 ** $_caller_matches(regexp [, number_of_frames])
1996 ** $_any_caller_is(name [, number_of_frames])
1997 ** $_any_caller_matches(regexp [, number_of_frames])
1999 * GDB now supports the compilation and injection of source code into
2000 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2001 to compile the source code to object code, and if successful, inject
2002 and execute that code within the current context of the inferior.
2003 Currently the C language is supported. The commands used to
2004 interface with this new feature are:
2006 compile code [-raw|-r] [--] [source code]
2007 compile file [-raw|-r] filename
2011 demangle [-l language] [--] name
2012 Demangle "name" in the specified language, or the current language
2013 if elided. This command is renamed from the "maint demangle" command.
2014 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2015 as "maint demangler-warning".
2017 queue-signal signal-name-or-number
2018 Queue a signal to be delivered to the thread when it is resumed.
2020 add-auto-load-scripts-directory directory
2021 Add entries to the list of directories from which to load auto-loaded
2024 maint print user-registers
2025 List all currently available "user" registers.
2027 compile code [-r|-raw] [--] [source code]
2028 Compile, inject, and execute in the inferior the executable object
2029 code produced by compiling the provided source code.
2031 compile file [-r|-raw] filename
2032 Compile and inject into the inferior the executable object code
2033 produced by compiling the source code stored in the filename
2036 * On resume, GDB now always passes the signal the program had stopped
2037 for to the thread the signal was sent to, even if the user changed
2038 threads before resuming. Previously GDB would often (but not
2039 always) deliver the signal to the thread that happens to be current
2042 * Conversely, the "signal" command now consistently delivers the
2043 requested signal to the current thread. GDB now asks for
2044 confirmation if the program had stopped for a signal and the user
2045 switched threads meanwhile.
2047 * "breakpoint always-inserted" modes "off" and "auto" merged.
2049 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2050 won't remove breakpoints from the target until all threads stop,
2051 even in non-stop mode. The "auto" mode has been removed, and "off"
2052 is now the default mode.
2056 set debug symbol-lookup
2057 show debug symbol-lookup
2058 Control display of debugging info regarding symbol lookup.
2062 ** The -list-thread-groups command outputs an exit-code field for
2063 inferiors that have exited.
2067 MIPS SDE mips*-sde*-elf*
2071 Support for these obsolete configurations has been removed.
2073 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2074 SGI Irix-5.x mips-*-irix5*
2075 SGI Irix-6.x mips-*-irix6*
2076 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2077 VAX running Ultrix vax-*-ultrix*
2079 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2080 and "assf"), have been removed. Use the "sharedlibrary" command, or
2081 its alias "share", instead.
2083 *** Changes in GDB 7.8
2085 * New command line options
2088 This is an alias for the --data-directory option.
2090 * GDB supports printing and modifying of variable length automatic arrays
2091 as specified in ISO C99.
2093 * The ARM simulator now supports instruction level tracing
2094 with or without disassembly.
2098 GDB now has support for scripting using Guile. Whether this is
2099 available is determined at configure time.
2100 Guile version 2.0 or greater is required.
2101 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2103 * New commands (for set/show, see "New options" below)
2107 Invoke CODE by passing it to the Guile interpreter.
2111 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2113 info auto-load guile-scripts [regexp]
2114 Print the list of automatically loaded Guile scripts.
2116 * The source command is now capable of sourcing Guile scripts.
2117 This feature is dependent on the debugger being built with Guile support.
2121 set print symbol-loading (off|brief|full)
2122 show print symbol-loading
2123 Control whether to print informational messages when loading symbol
2124 information for a file. The default is "full", but when debugging
2125 programs with large numbers of shared libraries the amount of output
2126 becomes less useful.
2128 set guile print-stack (none|message|full)
2129 show guile print-stack
2130 Show a stack trace when an error is encountered in a Guile script.
2132 set auto-load guile-scripts (on|off)
2133 show auto-load guile-scripts
2134 Control auto-loading of Guile script files.
2136 maint ada set ignore-descriptive-types (on|off)
2137 maint ada show ignore-descriptive-types
2138 Control whether the debugger should ignore descriptive types in Ada
2139 programs. The default is not to ignore the descriptive types. See
2140 the user manual for more details on descriptive types and the intended
2141 usage of this option.
2143 set auto-connect-native-target
2145 Control whether GDB is allowed to automatically connect to the
2146 native target for the run, attach, etc. commands when not connected
2147 to any target yet. See also "target native" below.
2149 set record btrace replay-memory-access (read-only|read-write)
2150 show record btrace replay-memory-access
2151 Control what memory accesses are allowed during replay.
2153 maint set target-async (on|off)
2154 maint show target-async
2155 This controls whether GDB targets operate in synchronous or
2156 asynchronous mode. Normally the default is asynchronous, if it is
2157 available; but this can be changed to more easily debug problems
2158 occurring only in synchronous mode.
2160 set mi-async (on|off)
2162 Control whether MI asynchronous mode is preferred. This supersedes
2163 "set target-async" of previous GDB versions.
2165 * "set target-async" is deprecated as a CLI option and is now an alias
2166 for "set mi-async" (only puts MI into async mode).
2168 * Background execution commands (e.g., "c&", "s&", etc.) are now
2169 possible ``out of the box'' if the target supports them. Previously
2170 the user would need to explicitly enable the possibility with the
2171 "set target-async on" command.
2173 * New features in the GDB remote stub, GDBserver
2175 ** New option --debug-format=option1[,option2,...] allows one to add
2176 additional text to each output. At present only timestamps
2177 are supported: --debug-format=timestamps.
2178 Timestamps can also be turned on with the
2179 "monitor set debug-format timestamps" command from GDB.
2181 * The 'record instruction-history' command now starts counting instructions
2182 at one. This also affects the instruction ranges reported by the
2183 'record function-call-history' command when given the /i modifier.
2185 * The command 'record function-call-history' supports a new modifier '/c' to
2186 indent the function names based on their call stack depth.
2187 The fields for the '/i' and '/l' modifier have been reordered.
2188 The source line range is now prefixed with 'at'.
2189 The instruction range is now prefixed with 'inst'.
2190 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2191 "record instruction-history" and "list" commands.
2193 * The ranges given as arguments to the 'record function-call-history' and
2194 'record instruction-history' commands are now inclusive.
2196 * The btrace record target now supports the 'record goto' command.
2197 For locations inside the execution trace, the back trace is computed
2198 based on the information stored in the execution trace.
2200 * The btrace record target supports limited reverse execution and replay.
2201 The target does not record data and therefore does not allow reading
2202 memory or registers.
2204 * The "catch syscall" command now works on s390*-linux* targets.
2206 * The "compare-sections" command is no longer specific to target
2207 remote. It now works with all targets.
2209 * All native targets are now consistently called "native".
2210 Consequently, the "target child", "target GNU", "target djgpp",
2211 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2212 commands have been replaced with "target native". The QNX/NTO port
2213 leaves the "procfs" target in place and adds a "native" target for
2214 consistency with other ports. The impact on users should be minimal
2215 as these commands previously either throwed an error, or were
2216 no-ops. The target's name is visible in the output of the following
2217 commands: "help target", "info target", "info files", "maint print
2220 * The "target native" command now connects to the native target. This
2221 can be used to launch native programs even when "set
2222 auto-connect-native-target" is set to off.
2224 * GDB now supports access to Intel MPX registers on GNU/Linux.
2226 * Support for Intel AVX-512 registers on GNU/Linux.
2227 Support displaying and modifying Intel AVX-512 registers
2228 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2230 * New remote packets
2232 qXfer:btrace:read's annex
2233 The qXfer:btrace:read packet supports a new annex 'delta' to read
2234 branch trace incrementally.
2238 ** Valid Python operations on gdb.Value objects representing
2239 structs/classes invoke the corresponding overloaded operators if
2241 ** New `Xmethods' feature in the Python API. Xmethods are
2242 additional methods or replacements for existing methods of a C++
2243 class. This feature is useful for those cases where a method
2244 defined in C++ source code could be inlined or optimized out by
2245 the compiler, making it unavailable to GDB.
2248 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2250 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2251 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2252 its alias "share", instead.
2254 * The commands "set remotebaud" and "show remotebaud" are no longer
2255 supported. Use "set serial baud" and "show serial baud" (respectively)
2260 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2261 target-async". The latter is left as a deprecated alias of the
2262 former for backward compatibility. If the target supports it,
2263 CLI background execution commands are now always possible by
2264 default, independently of whether the frontend stated a
2265 preference for asynchronous execution with "-gdb-set mi-async".
2266 Previously "-gdb-set target-async off" affected both MI execution
2267 commands and CLI execution commands.
2269 *** Changes in GDB 7.7
2271 * Improved support for process record-replay and reverse debugging on
2272 arm*-linux* targets. Support for thumb32 and syscall instruction
2273 recording has been added.
2275 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2277 * GDB now supports Fission DWP file format version 2.
2278 http://gcc.gnu.org/wiki/DebugFission
2280 * New convenience function "$_isvoid", to check whether an expression
2281 is void. A void expression is an expression where the type of the
2282 result is "void". For example, some convenience variables may be
2283 "void" when evaluated (e.g., "$_exitcode" before the execution of
2284 the program being debugged; or an undefined convenience variable).
2285 Another example, when calling a function whose return type is
2288 * The "maintenance print objfiles" command now takes an optional regexp.
2290 * The "catch syscall" command now works on arm*-linux* targets.
2292 * GDB now consistently shows "<not saved>" when printing values of
2293 registers the debug info indicates have not been saved in the frame
2294 and there's nowhere to retrieve them from
2295 (callee-saved/call-clobbered registers):
2300 (gdb) info registers rax
2303 Before, the former would print "<optimized out>", and the latter
2304 "*value not available*".
2306 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2311 ** Frame filters and frame decorators have been added.
2312 ** Temporary breakpoints are now supported.
2313 ** Line tables representation has been added.
2314 ** New attribute 'parent_type' for gdb.Field objects.
2315 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2316 ** New attribute 'name' for gdb.Type objects.
2320 Nios II ELF nios2*-*-elf
2321 Nios II GNU/Linux nios2*-*-linux
2322 Texas Instruments MSP430 msp430*-*-elf
2324 * Removed native configurations
2326 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2327 been removed. ELF variants of these configurations are kept supported.
2329 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2330 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2331 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2332 i[34567]86-*-openbsd3.[0-3]
2333 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2334 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2335 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2339 Like "catch throw", but catches a re-thrown exception.
2340 maint check-psymtabs
2341 Renamed from old "maint check-symtabs".
2343 Perform consistency checks on symtabs.
2344 maint expand-symtabs
2345 Expand symtabs matching an optional regexp.
2348 Display the details of GDB configure-time options.
2350 maint set|show per-command
2351 maint set|show per-command space
2352 maint set|show per-command time
2353 maint set|show per-command symtab
2354 Enable display of per-command gdb resource usage.
2356 remove-symbol-file FILENAME
2357 remove-symbol-file -a ADDRESS
2358 Remove a symbol file added via add-symbol-file. The file to remove
2359 can be identified by its filename or by an address that lies within
2360 the boundaries of this symbol file in memory.
2363 info exceptions REGEXP
2364 Display the list of Ada exceptions defined in the program being
2365 debugged. If provided, only the exceptions whose names match REGEXP
2370 set debug symfile off|on
2372 Control display of debugging info regarding reading symbol files and
2373 symbol tables within those files
2375 set print raw frame-arguments
2376 show print raw frame-arguments
2377 Set/show whether to print frame arguments in raw mode,
2378 disregarding any defined pretty-printers.
2380 set remote trace-status-packet
2381 show remote trace-status-packet
2382 Set/show the use of remote protocol qTStatus packet.
2386 Control display of debugging messages related to Nios II targets.
2390 Control whether target-assisted range stepping is enabled.
2392 set startup-with-shell
2393 show startup-with-shell
2394 Specifies whether Unix child processes are started via a shell or
2399 Use the target memory cache for accesses to the code segment. This
2400 improves performance of remote debugging (particularly disassembly).
2402 * You can now use a literal value 'unlimited' for options that
2403 interpret 0 or -1 as meaning "unlimited". E.g., "set
2404 trace-buffer-size unlimited" is now an alias for "set
2405 trace-buffer-size -1" and "set height unlimited" is now an alias for
2408 * The "set debug symtab-create" debugging option of GDB has been changed to
2409 accept a verbosity level. 0 means "off", 1 provides basic debugging
2410 output, and values of 2 or greater provides more verbose output.
2412 * New command-line options
2414 Display the details of GDB configure-time options.
2416 * The command 'tsave' can now support new option '-ctf' to save trace
2417 buffer in Common Trace Format.
2419 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2422 * GDB now implements the C++ 'typeid' operator.
2424 * The new convenience variable $_exception holds the exception being
2425 thrown or caught at an exception-related catchpoint.
2427 * The exception-related catchpoints, like "catch throw", now accept a
2428 regular expression which can be used to filter exceptions by type.
2430 * The new convenience variable $_exitsignal is automatically set to
2431 the terminating signal number when the program being debugged dies
2432 due to an uncaught signal.
2436 ** All MI commands now accept an optional "--language" option.
2437 Support for this feature can be verified by using the "-list-features"
2438 command, which should contain "language-option".
2440 ** The new command -info-gdb-mi-command allows the user to determine
2441 whether a GDB/MI command is supported or not.
2443 ** The "^error" result record returned when trying to execute an undefined
2444 GDB/MI command now provides a variable named "code" whose content is the
2445 "undefined-command" error code. Support for this feature can be verified
2446 by using the "-list-features" command, which should contain
2447 "undefined-command-error-code".
2449 ** The -trace-save MI command can optionally save trace buffer in Common
2452 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2454 ** The command -data-list-register-values now accepts an optional
2455 "--skip-unavailable" option. When used, only the available registers
2458 ** The new command -trace-frame-collected dumps collected variables,
2459 computed expressions, tvars, memory and registers in a traceframe.
2461 ** The commands -stack-list-locals, -stack-list-arguments and
2462 -stack-list-variables now accept an option "--skip-unavailable".
2463 When used, only the available locals or arguments are displayed.
2465 ** The -exec-run command now accepts an optional "--start" option.
2466 When used, the command follows the same semantics as the "start"
2467 command, stopping the program's execution at the start of its
2468 main subprogram. Support for this feature can be verified using
2469 the "-list-features" command, which should contain
2470 "exec-run-start-option".
2472 ** The new commands -catch-assert and -catch-exceptions insert
2473 catchpoints stopping the program when Ada exceptions are raised.
2475 ** The new command -info-ada-exceptions provides the equivalent of
2476 the new "info exceptions" command.
2478 * New system-wide configuration scripts
2479 A GDB installation now provides scripts suitable for use as system-wide
2480 configuration scripts for the following systems:
2484 * GDB now supports target-assigned range stepping with remote targets.
2485 This improves the performance of stepping source lines by reducing
2486 the number of control packets from/to GDB. See "New remote packets"
2489 * GDB now understands the element 'tvar' in the XML traceframe info.
2490 It has the id of the collected trace state variables.
2492 * On S/390 targets that provide the transactional-execution feature,
2493 the program interruption transaction diagnostic block (TDB) is now
2494 represented as a number of additional "registers" in GDB.
2496 * New remote packets
2500 The vCont packet supports a new 'r' action, that tells the remote
2501 stub to step through an address range itself, without GDB
2502 involvemement at each single-step.
2504 qXfer:libraries-svr4:read's annex
2505 The previously unused annex of the qXfer:libraries-svr4:read packet
2506 is now used to support passing an argument list. The remote stub
2507 reports support for this argument list to GDB's qSupported query.
2508 The defined arguments are "start" and "prev", used to reduce work
2509 necessary for library list updating, resulting in significant
2512 * New features in the GDB remote stub, GDBserver
2514 ** GDBserver now supports target-assisted range stepping. Currently
2515 enabled on x86/x86_64 GNU/Linux targets.
2517 ** GDBserver now adds element 'tvar' in the XML in the reply to
2518 'qXfer:traceframe-info:read'. It has the id of the collected
2519 trace state variables.
2521 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2524 * New 'z' formatter for printing and examining memory, this displays the
2525 value as hexadecimal zero padded on the left to the size of the type.
2527 * GDB can now use Windows x64 unwinding data.
2529 * The "set remotebaud" command has been replaced by "set serial baud".
2530 Similarly, "show remotebaud" has been replaced by "show serial baud".
2531 The "set remotebaud" and "show remotebaud" commands are still available
2532 to provide backward compatibility with older versions of GDB.
2534 *** Changes in GDB 7.6
2536 * Target record has been renamed to record-full.
2537 Record/replay is now enabled with the "record full" command.
2538 This also affects settings that are associated with full record/replay
2539 that have been moved from "set/show record" to "set/show record full":
2541 set|show record full insn-number-max
2542 set|show record full stop-at-limit
2543 set|show record full memory-query
2545 * A new record target "record-btrace" has been added. The new target
2546 uses hardware support to record the control-flow of a process. It
2547 does not support replaying the execution, but it implements the
2548 below new commands for investigating the recorded execution log.
2549 This new recording method can be enabled using:
2553 The "record-btrace" target is only available on Intel Atom processors
2554 and requires a Linux kernel 2.6.32 or later.
2556 * Two new commands have been added for record/replay to give information
2557 about the recorded execution without having to replay the execution.
2558 The commands are only supported by "record btrace".
2560 record instruction-history prints the execution history at
2561 instruction granularity
2563 record function-call-history prints the execution history at
2564 function granularity
2566 * New native configurations
2568 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2569 FreeBSD/powerpc powerpc*-*-freebsd
2570 x86_64/Cygwin x86_64-*-cygwin*
2571 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2575 ARM AArch64 aarch64*-*-elf
2576 ARM AArch64 GNU/Linux aarch64*-*-linux
2577 Lynx 178 PowerPC powerpc-*-lynx*178
2578 x86_64/Cygwin x86_64-*-cygwin*
2579 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2581 * If the configured location of system.gdbinit file (as given by the
2582 --with-system-gdbinit option at configure time) is in the
2583 data-directory (as specified by --with-gdb-datadir at configure
2584 time) or in one of its subdirectories, then GDB will look for the
2585 system-wide init file in the directory specified by the
2586 --data-directory command-line option.
2588 * New command line options:
2590 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2591 other initialization files, unlike -nx which disables all of them.
2593 * Removed command line options
2595 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2598 * The 'ptype' and 'whatis' commands now accept an argument to control
2601 * 'info proc' now works on some core files.
2605 ** Vectors can be created with gdb.Type.vector.
2607 ** Python's atexit.register now works in GDB.
2609 ** Types can be pretty-printed via a Python API.
2611 ** Python 3 is now supported (in addition to Python 2.4 or later)
2613 ** New class gdb.Architecture exposes GDB's internal representation
2614 of architecture in the Python API.
2616 ** New method Frame.architecture returns the gdb.Architecture object
2617 corresponding to the frame's architecture.
2619 * New Python-based convenience functions:
2621 ** $_memeq(buf1, buf2, length)
2622 ** $_streq(str1, str2)
2624 ** $_regex(str, regex)
2626 * The 'cd' command now defaults to using '~' (the home directory) if not
2629 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2630 default for GCC since November 2000.
2632 * The command 'forward-search' can now be abbreviated as 'fo'.
2634 * The command 'info tracepoints' can now display 'installed on target'
2635 or 'not installed on target' for each non-pending location of tracepoint.
2637 * New configure options
2639 --enable-libmcheck/--disable-libmcheck
2640 By default, development versions are built with -lmcheck on hosts
2641 that support it, in order to help track memory corruption issues.
2642 Release versions, on the other hand, are built without -lmcheck
2643 by default. The --enable-libmcheck/--disable-libmcheck configure
2644 options allow the user to override that default.
2645 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2646 This configure option allows the user to build GDB with
2647 libbabeltrace using which GDB can read Common Trace Format data.
2649 * New commands (for set/show, see "New options" below)
2652 Catch signals. This is similar to "handle", but allows commands and
2653 conditions to be attached.
2656 List the BFDs known to GDB.
2658 python-interactive [command]
2660 Start a Python interactive prompt, or evaluate the optional command
2661 and print the result of expressions.
2664 "py" is a new alias for "python".
2666 enable type-printer [name]...
2667 disable type-printer [name]...
2668 Enable or disable type printers.
2672 ** For the Renesas Super-H architecture, the "regs" command has been removed
2673 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2678 set print type methods (on|off)
2679 show print type methods
2680 Control whether method declarations are displayed by "ptype".
2681 The default is to show them.
2683 set print type typedefs (on|off)
2684 show print type typedefs
2685 Control whether typedef definitions are displayed by "ptype".
2686 The default is to show them.
2688 set filename-display basename|relative|absolute
2689 show filename-display
2690 Control the way in which filenames is displayed.
2691 The default is "relative", which preserves previous behavior.
2693 set trace-buffer-size
2694 show trace-buffer-size
2695 Request target to change the size of trace buffer.
2697 set remote trace-buffer-size-packet auto|on|off
2698 show remote trace-buffer-size-packet
2699 Control the use of the remote protocol `QTBuffer:size' packet.
2703 Control display of debugging messages related to ARM AArch64.
2706 set debug coff-pe-read
2707 show debug coff-pe-read
2708 Control display of debugging messages related to reading of COFF/PE
2713 Control display of debugging messages related to Mach-O symbols
2716 set debug notification
2717 show debug notification
2718 Control display of debugging info for async remote notification.
2722 ** Command parameter changes are now notified using new async record
2723 "=cmd-param-changed".
2724 ** Trace frame changes caused by command "tfind" are now notified using
2725 new async record "=traceframe-changed".
2726 ** The creation, deletion and modification of trace state variables
2727 are now notified using new async records "=tsv-created",
2728 "=tsv-deleted" and "=tsv-modified".
2729 ** The start and stop of process record are now notified using new
2730 async record "=record-started" and "=record-stopped".
2731 ** Memory changes are now notified using new async record
2733 ** The data-disassemble command response will include a "fullname" field
2734 containing the absolute file name when source has been requested.
2735 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2736 command, to allow pattern filling of memory areas.
2737 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2738 library load/unload events.
2739 ** The response to breakpoint commands and breakpoint async records
2740 includes an "installed" field containing a boolean state about each
2741 non-pending tracepoint location is whether installed on target or not.
2742 ** Output of the "-trace-status" command includes a "trace-file" field
2743 containing the name of the trace file being examined. This field is
2744 optional, and only present when examining a trace file.
2745 ** The "fullname" field is now always present along with the "file" field,
2746 even if the file cannot be found by GDB.
2748 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2749 You must have the LZMA library available when configuring GDB for this
2750 feature to be enabled. For more information, see:
2751 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2753 * New remote packets
2756 Set the size of trace buffer. The remote stub reports support for this
2757 packet to gdb's qSupported query.
2760 Enable Branch Trace Store (BTS)-based branch tracing for the current
2761 thread. The remote stub reports support for this packet to gdb's
2765 Disable branch tracing for the current thread. The remote stub reports
2766 support for this packet to gdb's qSupported query.
2769 Read the traced branches for the current thread. The remote stub
2770 reports support for this packet to gdb's qSupported query.
2772 *** Changes in GDB 7.5
2774 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2775 for more x32 ABI info.
2777 * GDB now supports access to MIPS DSP registers on Linux targets.
2779 * GDB now supports debugging microMIPS binaries.
2781 * The "info os" command on GNU/Linux can now display information on
2782 several new classes of objects managed by the operating system:
2783 "info os procgroups" lists process groups
2784 "info os files" lists file descriptors
2785 "info os sockets" lists internet-domain sockets
2786 "info os shm" lists shared-memory regions
2787 "info os semaphores" lists semaphores
2788 "info os msg" lists message queues
2789 "info os modules" lists loaded kernel modules
2791 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2792 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2793 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2794 options and inspect the probe arguments using the new $_probe_arg family
2795 of convenience variables. You can obtain more information about SystemTap
2796 in <http://sourceware.org/systemtap/>.
2798 * GDB now supports reversible debugging on ARM, it allows you to
2799 debug basic ARM and THUMB instructions, and provides
2800 record/replay support.
2802 * The option "symbol-reloading" has been deleted as it is no longer used.
2806 ** GDB commands implemented in Python can now be put in command class
2809 ** The "maint set python print-stack on|off" is now deleted.
2811 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2812 apply "flag enum"-style pretty-printing to any enum.
2814 ** gdb.lookup_symbol can now work when there is no current frame.
2816 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2817 the source at which the symbol was defined.
2819 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2820 method 'value'. The former indicates whether the symbol needs a
2821 frame in order to compute its value, and the latter computes the
2824 ** A new method 'referenced_value' on gdb.Value objects which can
2825 dereference pointer as well as C++ reference values.
2827 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2828 which return the global and static blocks (as gdb.Block objects),
2829 of the underlying symbol table, respectively.
2831 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2832 object associated with a PC value.
2834 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2835 of the address range occupied by code for the current source line.
2837 * Go language support.
2838 GDB now supports debugging programs written in the Go programming
2841 * GDBserver now supports stdio connections.
2842 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2844 * The binary "gdbtui" can no longer be built or installed.
2845 Use "gdb -tui" instead.
2847 * GDB will now print "flag" enums specially. A flag enum is one where
2848 all the enumerator values have no bits in common when pairwise
2849 "and"ed. When printing a value whose type is a flag enum, GDB will
2850 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2851 (gdb) print (enum E) 3
2854 * The filename part of a linespec will now match trailing components
2855 of a source file name. For example, "break gcc/expr.c:1000" will
2856 now set a breakpoint in build/gcc/expr.c, but not
2857 build/libcpp/expr.c.
2859 * The "info proc" and "generate-core-file" commands will now also
2860 work on remote targets connected to GDBserver on Linux.
2862 * The command "info catch" has been removed. It has been disabled
2863 since December 2007.
2865 * The "catch exception" and "catch assert" commands now accept
2866 a condition at the end of the command, much like the "break"
2867 command does. For instance:
2869 (gdb) catch exception Constraint_Error if Barrier = True
2871 Previously, it was possible to add a condition to such catchpoints,
2872 but it had to be done as a second step, after the catchpoint had been
2873 created, using the "condition" command.
2875 * The "info static-tracepoint-marker" command will now also work on
2876 native Linux targets with in-process agent.
2878 * GDB can now set breakpoints on inlined functions.
2880 * The .gdb_index section has been updated to include symbols for
2881 inlined functions. GDB will ignore older .gdb_index sections by
2882 default, which could cause symbol files to be loaded more slowly
2883 until their .gdb_index sections can be recreated. The new command
2884 "set use-deprecated-index-sections on" will cause GDB to use any older
2885 .gdb_index sections it finds. This will restore performance, but the
2886 ability to set breakpoints on inlined functions will be lost in symbol
2887 files with older .gdb_index sections.
2889 The .gdb_index section has also been updated to record more information
2890 about each symbol. This speeds up the "info variables", "info functions"
2891 and "info types" commands when used with programs having the .gdb_index
2892 section, as well as speeding up debugging with shared libraries using
2893 the .gdb_index section.
2895 * Ada support for GDB/MI Variable Objects has been added.
2897 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2902 ** New command -info-os is the MI equivalent of "info os".
2904 ** Output logs ("set logging" and related) now include MI output.
2908 ** "set use-deprecated-index-sections on|off"
2909 "show use-deprecated-index-sections on|off"
2910 Controls the use of deprecated .gdb_index sections.
2912 ** "catch load" and "catch unload" can be used to stop when a shared
2913 library is loaded or unloaded, respectively.
2915 ** "enable count" can be used to auto-disable a breakpoint after
2918 ** "info vtbl" can be used to show the virtual method tables for
2919 C++ and Java objects.
2921 ** "explore" and its sub commands "explore value" and "explore type"
2922 can be used to recursively explore values and types of
2923 expressions. These commands are available only if GDB is
2924 configured with '--with-python'.
2926 ** "info auto-load" shows status of all kinds of auto-loaded files,
2927 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2928 sequences of commands files, "info auto-load python-scripts"
2929 shows status of auto-loading Python script files,
2930 "info auto-load local-gdbinit" shows status of loading init file
2931 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2932 status of inferior specific thread debugging shared library loading.
2934 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2935 and "show auto-load-scripts" commands have been deprecated, use their
2936 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2937 and "show auto-load python-scripts" counterparts instead.
2939 ** "dprintf location,format,args..." creates a dynamic printf, which
2940 is basically a breakpoint that does a printf and immediately
2941 resumes your program's execution, so it is like a printf that you
2942 can insert dynamically at runtime instead of at compiletime.
2944 ** "set print symbol"
2946 Controls whether GDB attempts to display the symbol, if any,
2947 corresponding to addresses it prints. This defaults to "on", but
2948 you can set it to "off" to restore GDB's previous behavior.
2950 * Deprecated commands
2952 ** For the Renesas Super-H architecture, the "regs" command has been
2953 deprecated, and "info all-registers" should be used instead.
2957 Renesas RL78 rl78-*-elf
2958 HP OpenVMS ia64 ia64-hp-openvms*
2960 * GDBserver supports evaluation of breakpoint conditions. When
2961 support is advertised by GDBserver, GDB may be told to send the
2962 breakpoint conditions in bytecode form to GDBserver. GDBserver
2963 will only report the breakpoint trigger to GDB when its condition
2968 set mips compression
2969 show mips compression
2970 Select the compressed ISA encoding used in functions that have no symbol
2971 information available. The encoding can be set to either of:
2974 and is updated automatically from ELF file flags if available.
2976 set breakpoint condition-evaluation
2977 show breakpoint condition-evaluation
2978 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2979 GDBserver ("target"). Default option "auto" chooses the most efficient
2981 This option can improve debugger efficiency depending on the speed of the
2985 Disable auto-loading globally.
2988 Show auto-loading setting of all kinds of auto-loaded files.
2990 set auto-load gdb-scripts on|off
2991 show auto-load gdb-scripts
2992 Control auto-loading of GDB canned sequences of commands files.
2994 set auto-load python-scripts on|off
2995 show auto-load python-scripts
2996 Control auto-loading of Python script files.
2998 set auto-load local-gdbinit on|off
2999 show auto-load local-gdbinit
3000 Control loading of init file (.gdbinit) from current directory.
3002 set auto-load libthread-db on|off
3003 show auto-load libthread-db
3004 Control auto-loading of inferior specific thread debugging shared library.
3006 set auto-load scripts-directory <dir1>[:<dir2>...]
3007 show auto-load scripts-directory
3008 Set a list of directories from which to load auto-loaded scripts.
3009 Automatically loaded Python scripts and GDB scripts are located in one
3010 of the directories listed by this option.
3011 The delimiter (':' above) may differ according to the host platform.
3013 set auto-load safe-path <dir1>[:<dir2>...]
3014 show auto-load safe-path
3015 Set a list of directories from which it is safe to auto-load files.
3016 The delimiter (':' above) may differ according to the host platform.
3018 set debug auto-load on|off
3019 show debug auto-load
3020 Control display of debugging info for auto-loading the files above.
3022 set dprintf-style gdb|call|agent
3024 Control the way in which a dynamic printf is performed; "gdb"
3025 requests a GDB printf command, while "call" causes dprintf to call a
3026 function in the inferior. "agent" requests that the target agent
3027 (such as GDBserver) do the printing.
3029 set dprintf-function <expr>
3030 show dprintf-function
3031 set dprintf-channel <expr>
3032 show dprintf-channel
3033 Set the function and optional first argument to the call when using
3034 the "call" style of dynamic printf.
3036 set disconnected-dprintf on|off
3037 show disconnected-dprintf
3038 Control whether agent-style dynamic printfs continue to be in effect
3039 after GDB disconnects.
3041 * New configure options
3043 --with-auto-load-dir
3044 Configure default value for the 'set auto-load scripts-directory'
3045 setting above. It defaults to '$debugdir:$datadir/auto-load',
3046 $debugdir representing global debugging info directories (available
3047 via 'show debug-file-directory') and $datadir representing GDB's data
3048 directory (available via 'show data-directory').
3050 --with-auto-load-safe-path
3051 Configure default value for the 'set auto-load safe-path' setting
3052 above. It defaults to the --with-auto-load-dir setting.
3054 --without-auto-load-safe-path
3055 Set 'set auto-load safe-path' to '/', effectively disabling this
3058 * New remote packets
3060 z0/z1 conditional breakpoints extension
3062 The z0/z1 breakpoint insertion packets have been extended to carry
3063 a list of conditional expressions over to the remote stub depending on the
3064 condition evaluation mode. The use of this extension can be controlled
3065 via the "set remote conditional-breakpoints-packet" command.
3069 Specify the signals which the remote stub may pass to the debugged
3070 program without GDB involvement.
3072 * New command line options
3074 --init-command=FILE, -ix Like --command, -x but execute it
3075 before loading inferior.
3076 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3077 execute it before loading inferior.
3079 *** Changes in GDB 7.4
3081 * GDB now handles ambiguous linespecs more consistently; the existing
3082 FILE:LINE support has been expanded to other types of linespecs. A
3083 breakpoint will now be set on all matching locations in all
3084 inferiors, and locations will be added or removed according to
3087 * GDB now allows you to skip uninteresting functions and files when
3088 stepping with the "skip function" and "skip file" commands.
3090 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3091 and "show remote hardware-watchpoint-length-limit". These allows to
3092 set or show the maximum length limit (in bytes) of a remote
3093 target hardware watchpoint.
3095 This allows e.g. to use "unlimited" hardware watchpoints with the
3096 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3097 watchpoints are slower than real hardware watchpoints but are
3098 significantly faster than gdb software watchpoints.
3102 ** The register_pretty_printer function in module gdb.printing now takes
3103 an optional `replace' argument. If True, the new printer replaces any
3106 ** The "maint set python print-stack on|off" command has been
3107 deprecated and will be deleted in GDB 7.5.
3108 A new command: "set python print-stack none|full|message" has
3109 replaced it. Additionally, the default for "print-stack" is
3110 now "message", which just prints the error message without
3113 ** A prompt substitution hook (prompt_hook) is now available to the
3116 ** A new Python module, gdb.prompt has been added to the GDB Python
3117 modules library. This module provides functionality for
3118 escape sequences in prompts (used by set/show
3119 extended-prompt). These escape sequences are replaced by their
3120 corresponding value.
3122 ** Python commands and convenience-functions located in
3123 'data-directory'/python/gdb/command and
3124 'data-directory'/python/gdb/function are now automatically loaded
3127 ** Blocks now provide four new attributes. global_block and
3128 static_block will return the global and static blocks
3129 respectively. is_static and is_global are boolean attributes
3130 that indicate if the block is one of those two types.
3132 ** Symbols now provide the "type" attribute, the type of the symbol.
3134 ** The "gdb.breakpoint" function has been deprecated in favor of
3137 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3138 of a function. This class is based on the "finish" command
3139 available in the CLI.
3141 ** Type objects for struct and union types now allow access to
3142 the fields using standard Python dictionary (mapping) methods.
3143 For example, "some_type['myfield']" now works, as does
3144 "some_type.items()".
3146 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3149 ** A new function, "deep_items" has been added to the gdb.types
3150 module in the GDB Python modules library. This function returns
3151 an iterator over the fields of a struct or union type. Unlike
3152 the standard Python "iteritems" method, it will recursively traverse
3153 any anonymous fields.
3157 ** "*stopped" events can report several new "reason"s, such as
3160 ** Breakpoint changes are now notified using new async records, like
3161 "=breakpoint-modified".
3163 ** New command -ada-task-info.
3165 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3166 $sdir specifies the default system locations of shared libraries.
3167 $pdir specifies the directory where the libpthread used by the application
3170 GDB no longer looks in $sdir and $pdir after it has searched the directories
3171 mentioned in libthread-db-search-path. If you want to search those
3172 directories, they must be specified in libthread-db-search-path.
3173 The default value of libthread-db-search-path on GNU/Linux and Solaris
3174 systems is now "$sdir:$pdir".
3176 $pdir is not supported by gdbserver, it is currently ignored.
3177 $sdir is supported by gdbserver.
3179 * New configure option --with-iconv-bin.
3180 When using the internationalization support like the one in the GNU C
3181 library, GDB will invoke the "iconv" program to get a list of supported
3182 character sets. If this program lives in a non-standard location, one can
3183 use this option to specify where to find it.
3185 * When natively debugging programs on PowerPC BookE processors running
3186 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3187 watchpoints, which specify a mask in addition to an address to watch.
3188 The mask specifies that some bits of an address (the bits which are
3189 reset in the mask) should be ignored when matching the address accessed
3190 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3191 section in the user manual for more details.
3193 * The new option --once causes GDBserver to stop listening for connections once
3194 the first connection is made. The listening port used by GDBserver will
3195 become available after that.
3197 * New commands "info macros" and "alias" have been added.
3199 * New function parameters suffix @entry specifies value of function parameter
3200 at the time the function got called. Entry values are available only since
3206 "!" is now an alias of the "shell" command.
3207 Note that no space is needed between "!" and SHELL COMMAND.
3211 watch EXPRESSION mask MASK_VALUE
3212 The watch command now supports the mask argument which allows creation
3213 of masked watchpoints, if the current architecture supports this feature.
3215 info auto-load-scripts [REGEXP]
3216 This command was formerly named "maintenance print section-scripts".
3217 It is now generally useful and is no longer a maintenance-only command.
3219 info macro [-all] [--] MACRO
3220 The info macro command has new options `-all' and `--'. The first for
3221 printing all definitions of a macro. The second for explicitly specifying
3222 the end of arguments and the beginning of the macro name in case the macro
3223 name starts with a hyphen.
3225 collect[/s] EXPRESSIONS
3226 The tracepoint collect command now takes an optional modifier "/s"
3227 that directs it to dereference pointer-to-character types and
3228 collect the bytes of memory up to a zero byte. The behavior is
3229 similar to what you see when you use the regular print command on a
3230 string. An optional integer following the "/s" sets a bound on the
3231 number of bytes that will be collected.
3234 The trace start command now interprets any supplied arguments as a
3235 note to be recorded with the trace run, with an effect similar to
3236 setting the variable trace-notes.
3239 The trace stop command now interprets any arguments as a note to be
3240 mentioned along with the tstatus report that the trace was stopped
3241 with a command. The effect is similar to setting the variable
3244 * Tracepoints can now be enabled and disabled at any time after a trace
3245 experiment has been started using the standard "enable" and "disable"
3246 commands. It is now possible to start a trace experiment with no enabled
3247 tracepoints; GDB will display a warning, but will allow the experiment to
3248 begin, assuming that tracepoints will be enabled as needed while the trace
3251 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3252 locations with 4-byte instructions, when they were previously
3253 limited to locations with instructions of 5 bytes or longer.
3257 set debug dwarf2-read
3258 show debug dwarf2-read
3259 Turns on or off display of debugging messages related to reading
3260 DWARF debug info. The default is off.
3262 set debug symtab-create
3263 show debug symtab-create
3264 Turns on or off display of debugging messages related to symbol table
3265 creation. The default is off.
3268 show extended-prompt
3269 Set the GDB prompt, and allow escape sequences to be inserted to
3270 display miscellaneous information (see 'help set extended-prompt'
3271 for the list of sequences). This prompt (and any information
3272 accessed through the escape sequences) is updated every time the
3273 prompt is displayed.
3275 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3276 show print entry-values
3277 Set printing of frame argument values at function entry. In some cases
3278 GDB can determine the value of function argument which was passed by the
3279 function caller, even if the value was modified inside the called function.
3281 set debug entry-values
3282 show debug entry-values
3283 Control display of debugging info for determining frame argument values at
3284 function entry and virtual tail call frames.
3286 set basenames-may-differ
3287 show basenames-may-differ
3288 Set whether a source file may have multiple base names.
3289 (A "base name" is the name of a file with the directory part removed.
3290 Example: The base name of "/home/user/hello.c" is "hello.c".)
3291 If set, GDB will canonicalize file names (e.g., expand symlinks)
3292 before comparing them. Canonicalization is an expensive operation,
3293 but it allows the same file be known by more than one base name.
3294 If not set (the default), all source files are assumed to have just
3295 one base name, and gdb will do file name comparisons more efficiently.
3301 Set a user name and notes for the current and any future trace runs.
3302 This is useful for long-running and/or disconnected traces, to
3303 inform others (or yourself) as to who is running the trace, supply
3304 contact information, or otherwise explain what is going on.
3306 set trace-stop-notes
3307 show trace-stop-notes
3308 Set a note attached to the trace run, that is displayed when the
3309 trace has been stopped by a tstop command. This is useful for
3310 instance as an explanation, if you are stopping a trace run that was
3311 started by someone else.
3313 * New remote packets
3317 Dynamically enable a tracepoint in a started trace experiment.
3321 Dynamically disable a tracepoint in a started trace experiment.
3325 Set the user and notes of the trace run.
3329 Query the current status of a tracepoint.
3333 Query the minimum length of instruction at which a fast tracepoint may
3336 * Dcache size (number of lines) and line-size are now runtime-configurable
3337 via "set dcache line" and "set dcache line-size" commands.
3341 Texas Instruments TMS320C6x tic6x-*-*
3345 Renesas RL78 rl78-*-elf
3347 *** Changes in GDB 7.3.1
3349 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3351 *** Changes in GDB 7.3
3353 * GDB has a new command: "thread find [REGEXP]".
3354 It finds the thread id whose name, target id, or thread extra info
3355 matches the given regular expression.
3357 * The "catch syscall" command now works on mips*-linux* targets.
3359 * The -data-disassemble MI command now supports modes 2 and 3 for
3360 dumping the instruction opcodes.
3362 * New command line options
3364 -data-directory DIR Specify DIR as the "data-directory".
3365 This is mostly for testing purposes.
3367 * The "maint set python auto-load on|off" command has been renamed to
3368 "set auto-load-scripts on|off".
3370 * GDB has a new command: "set directories".
3371 It is like the "dir" command except that it replaces the
3372 source path list instead of augmenting it.
3374 * GDB now understands thread names.
3376 On GNU/Linux, "info threads" will display the thread name as set by
3377 prctl or pthread_setname_np.
3379 There is also a new command, "thread name", which can be used to
3380 assign a name internally for GDB to display.
3383 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3384 has been integrated into GDB.
3388 ** The function gdb.Write now accepts an optional keyword 'stream'.
3389 This keyword, when provided, will direct the output to either
3390 stdout, stderr, or GDB's logging output.
3392 ** Parameters can now be be sub-classed in Python, and in particular
3393 you may implement the get_set_doc and get_show_doc functions.
3394 This improves how Parameter set/show documentation is processed
3395 and allows for more dynamic content.
3397 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3398 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3399 have an is_valid method.
3401 ** Breakpoints can now be sub-classed in Python, and in particular
3402 you may implement a 'stop' function that is executed each time
3403 the inferior reaches that breakpoint.
3405 ** New function gdb.lookup_global_symbol looks up a global symbol.
3407 ** GDB values in Python are now callable if the value represents a
3408 function. For example, if 'some_value' represents a function that
3409 takes two integer parameters and returns a value, you can call
3410 that function like so:
3412 result = some_value (10,20)
3414 ** Module gdb.types has been added.
3415 It contains a collection of utilities for working with gdb.Types objects:
3416 get_basic_type, has_field, make_enum_dict.
3418 ** Module gdb.printing has been added.
3419 It contains utilities for writing and registering pretty-printers.
3420 New classes: PrettyPrinter, SubPrettyPrinter,
3421 RegexpCollectionPrettyPrinter.
3422 New function: register_pretty_printer.
3424 ** New commands "info pretty-printers", "enable pretty-printer" and
3425 "disable pretty-printer" have been added.
3427 ** gdb.parameter("directories") is now available.
3429 ** New function gdb.newest_frame returns the newest frame in the
3432 ** The gdb.InferiorThread class has a new "name" attribute. This
3433 holds the thread's name.
3435 ** Python Support for Inferior events.
3436 Python scripts can add observers to be notified of events
3437 occurring in the process being debugged.
3438 The following events are currently supported:
3439 - gdb.events.cont Continue event.
3440 - gdb.events.exited Inferior exited event.
3441 - gdb.events.stop Signal received, and Breakpoint hit events.
3445 ** GDB now puts template parameters in scope when debugging in an
3446 instantiation. For example, if you have:
3448 template<int X> int func (void) { return X; }
3450 then if you step into func<5>, "print X" will show "5". This
3451 feature requires proper debuginfo support from the compiler; it
3452 was added to GCC 4.5.
3454 ** The motion commands "next", "finish", "until", and "advance" now
3455 work better when exceptions are thrown. In particular, GDB will
3456 no longer lose control of the inferior; instead, the GDB will
3457 stop the inferior at the point at which the exception is caught.
3458 This functionality requires a change in the exception handling
3459 code that was introduced in GCC 4.5.
3461 * GDB now follows GCC's rules on accessing volatile objects when
3462 reading or writing target state during expression evaluation.
3463 One notable difference to prior behavior is that "print x = 0"
3464 no longer generates a read of x; the value of the assignment is
3465 now always taken directly from the value being assigned.
3467 * GDB now has some support for using labels in the program's source in
3468 linespecs. For instance, you can use "advance label" to continue
3469 execution to a label.
3471 * GDB now has support for reading and writing a new .gdb_index
3472 section. This section holds a fast index of DWARF debugging
3473 information and can be used to greatly speed up GDB startup and
3474 operation. See the documentation for `save gdb-index' for details.
3476 * The "watch" command now accepts an optional "-location" argument.
3477 When used, this causes GDB to watch the memory referred to by the
3478 expression. Such a watchpoint is never deleted due to it going out
3481 * GDB now supports thread debugging of core dumps on GNU/Linux.
3483 GDB now activates thread debugging using the libthread_db library
3484 when debugging GNU/Linux core dumps, similarly to when debugging
3485 live processes. As a result, when debugging a core dump file, GDB
3486 is now able to display pthread_t ids of threads. For example, "info
3487 threads" shows the same output as when debugging the process when it
3488 was live. In earlier releases, you'd see something like this:
3491 * 1 LWP 6780 main () at main.c:10
3493 While now you see this:
3496 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3498 It is also now possible to inspect TLS variables when debugging core
3501 When debugging a core dump generated on a machine other than the one
3502 used to run GDB, you may need to point GDB at the correct
3503 libthread_db library with the "set libthread-db-search-path"
3504 command. See the user manual for more details on this command.
3506 * When natively debugging programs on PowerPC BookE processors running
3507 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3508 which stop execution of the inferior whenever it executes an instruction
3509 at any address within the specified range. See the "PowerPC Embedded"
3510 section in the user manual for more details.
3512 * New features in the GDB remote stub, GDBserver
3514 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3515 and i686 LynxOS (version 5.x).
3517 ** GDBserver is now supported on Blackfin Linux.
3519 * New native configurations
3521 ia64 HP-UX ia64-*-hpux*
3525 Analog Devices, Inc. Blackfin Processor bfin-*
3527 * Ada task switching is now supported on sparc-elf targets when
3528 debugging a program using the Ravenscar Profile. For more information,
3529 see the "Tasking Support when using the Ravenscar Profile" section
3530 in the GDB user manual.
3532 * Guile support was removed.
3534 * New features in the GNU simulator
3536 ** The --map-info flag lists all known core mappings.
3538 ** CFI flashes may be simulated via the "cfi" device.
3540 *** Changes in GDB 7.2
3542 * Shared library support for remote targets by default
3544 When GDB is configured for a generic, non-OS specific target, like
3545 for example, --target=arm-eabi or one of the many *-*-elf targets,
3546 GDB now queries remote stubs for loaded shared libraries using the
3547 `qXfer:libraries:read' packet. Previously, shared library support
3548 was always disabled for such configurations.
3552 ** Argument Dependent Lookup (ADL)
3554 In C++ ADL lookup directs function search to the namespaces of its
3555 arguments even if the namespace has not been imported.
3565 Here the compiler will search for `foo' in the namespace of 'b'
3566 and find A::foo. GDB now supports this. This construct is commonly
3567 used in the Standard Template Library for operators.
3569 ** Improved User Defined Operator Support
3571 In addition to member operators, GDB now supports lookup of operators
3572 defined in a namespace and imported with a `using' directive, operators
3573 defined in the global scope, operators imported implicitly from an
3574 anonymous namespace, and the ADL operators mentioned in the previous
3576 GDB now also supports proper overload resolution for all the previously
3577 mentioned flavors of operators.
3579 ** static const class members
3581 Printing of static const class members that are initialized in the
3582 class definition has been fixed.
3584 * Windows Thread Information Block access.
3586 On Windows targets, GDB now supports displaying the Windows Thread
3587 Information Block (TIB) structure. This structure is visible either
3588 by using the new command `info w32 thread-information-block' or, by
3589 dereferencing the new convenience variable named `$_tlb', a
3590 thread-specific pointer to the TIB. This feature is also supported
3591 when remote debugging using GDBserver.
3593 * Static tracepoints
3595 Static tracepoints are calls in the user program into a tracing
3596 library. One such library is a port of the LTTng kernel tracer to
3597 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3598 When debugging with GDBserver, GDB now supports combining the GDB
3599 tracepoint machinery with such libraries. For example: the user can
3600 use GDB to probe a static tracepoint marker (a call from the user
3601 program into the tracing library) with the new "strace" command (see
3602 "New commands" below). This creates a "static tracepoint" in the
3603 breakpoint list, that can be manipulated with the same feature set
3604 as fast and regular tracepoints. E.g., collect registers, local and
3605 global variables, collect trace state variables, and define
3606 tracepoint conditions. In addition, the user can collect extra
3607 static tracepoint marker specific data, by collecting the new
3608 $_sdata internal variable. When analyzing the trace buffer, you can
3609 inspect $_sdata like any other variable available to GDB. For more
3610 information, see the "Tracepoints" chapter in GDB user manual. New
3611 remote packets have been defined to support static tracepoints, see
3612 the "New remote packets" section below.
3614 * Better reconstruction of tracepoints after disconnected tracing
3616 GDB will attempt to download the original source form of tracepoint
3617 definitions when starting a trace run, and then will upload these
3618 upon reconnection to the target, resulting in a more accurate
3619 reconstruction of the tracepoints that are in use on the target.
3623 You can now exercise direct control over the ways that GDB can
3624 affect your program. For instance, you can disallow the setting of
3625 breakpoints, so that the program can run continuously (assuming
3626 non-stop mode). In addition, the "observer" variable is available
3627 to switch all of the different controls; in observer mode, GDB
3628 cannot affect the target's behavior at all, which is useful for
3629 tasks like diagnosing live systems in the field.
3631 * The new convenience variable $_thread holds the number of the
3634 * New remote packets
3638 Return the address of the Windows Thread Information Block of a given thread.
3642 In response to several of the tracepoint packets, the target may now
3643 also respond with a number of intermediate `qRelocInsn' request
3644 packets before the final result packet, to have GDB handle
3645 relocating an instruction to execute at a different address. This
3646 is particularly useful for stubs that support fast tracepoints. GDB
3647 reports support for this feature in the qSupported packet.
3651 List static tracepoint markers in the target program.
3655 List static tracepoint markers at a given address in the target
3658 qXfer:statictrace:read
3660 Read the static trace data collected (by a `collect $_sdata'
3661 tracepoint action). The remote stub reports support for this packet
3662 to gdb's qSupported query.
3666 Send the current settings of GDB's permission flags.
3670 Send part of the source (textual) form of a tracepoint definition,
3671 which includes location, conditional, and action list.
3673 * The source command now accepts a -s option to force searching for the
3674 script in the source search path even if the script name specifies
3677 * New features in the GDB remote stub, GDBserver
3679 - GDBserver now support tracepoints (including fast tracepoints, and
3680 static tracepoints). The feature is currently supported by the
3681 i386-linux and amd64-linux builds. See the "Tracepoints support
3682 in gdbserver" section in the manual for more information.
3684 GDBserver JIT compiles the tracepoint's conditional agent
3685 expression bytecode into native code whenever possible for low
3686 overhead dynamic tracepoints conditionals. For such tracepoints,
3687 an expression that examines program state is evaluated when the
3688 tracepoint is reached, in order to determine whether to capture
3689 trace data. If the condition is simple and false, processing the
3690 tracepoint finishes very quickly and no data is gathered.
3692 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3693 for static tracepoints support.
3695 - GDBserver now supports x86_64 Windows 64-bit debugging.
3697 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3698 it understands register description.
3700 * The --batch flag now disables pagination and queries.
3702 * X86 general purpose registers
3704 GDB now supports reading/writing byte, word and double-word x86
3705 general purpose registers directly. This means you can use, say,
3706 $ah or $ax to refer, respectively, to the byte register AH and
3707 16-bit word register AX that are actually portions of the 32-bit
3708 register EAX or 64-bit register RAX.
3710 * The `commands' command now accepts a range of breakpoints to modify.
3711 A plain `commands' following a command that creates multiple
3712 breakpoints affects all the breakpoints set by that command. This
3713 applies to breakpoints set by `rbreak', and also applies when a
3714 single `break' command creates multiple breakpoints (e.g.,
3715 breakpoints on overloaded c++ functions).
3717 * The `rbreak' command now accepts a filename specification as part of
3718 its argument, limiting the functions selected by the regex to those
3719 in the specified file.
3721 * Support for remote debugging Windows and SymbianOS shared libraries
3722 from Unix hosts has been improved. Non Windows GDB builds now can
3723 understand target reported file names that follow MS-DOS based file
3724 system semantics, such as file names that include drive letters and
3725 use the backslash character as directory separator. This makes it
3726 possible to transparently use the "set sysroot" and "set
3727 solib-search-path" on Unix hosts to point as host copies of the
3728 target's shared libraries. See the new command "set
3729 target-file-system-kind" described below, and the "Commands to
3730 specify files" section in the user manual for more information.
3734 eval template, expressions...
3735 Convert the values of one or more expressions under the control
3736 of the string template to a command line, and call it.
3738 set target-file-system-kind unix|dos-based|auto
3739 show target-file-system-kind
3740 Set or show the assumed file system kind for target reported file
3743 save breakpoints <filename>
3744 Save all current breakpoint definitions to a file suitable for use
3745 in a later debugging session. To read the saved breakpoint
3746 definitions, use the `source' command.
3748 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3751 info static-tracepoint-markers
3752 Display information about static tracepoint markers in the target.
3754 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3755 Define a static tracepoint by probing a marker at the given
3756 function, line, address, or marker ID.
3760 Enable and disable observer mode.
3762 set may-write-registers on|off
3763 set may-write-memory on|off
3764 set may-insert-breakpoints on|off
3765 set may-insert-tracepoints on|off
3766 set may-insert-fast-tracepoints on|off
3767 set may-interrupt on|off
3768 Set individual permissions for GDB effects on the target. Note that
3769 some of these settings can have undesirable or surprising
3770 consequences, particularly when changed in the middle of a session.
3771 For instance, disabling the writing of memory can prevent
3772 breakpoints from being inserted, cause single-stepping to fail, or
3773 even crash your program, if you disable after breakpoints have been
3774 inserted. However, GDB should not crash.
3776 set record memory-query on|off
3777 show record memory-query
3778 Control whether to stop the inferior if memory changes caused
3779 by an instruction cannot be recorded.
3784 The disassemble command now supports "start,+length" form of two arguments.
3788 ** GDB now provides a new directory location, called the python directory,
3789 where Python scripts written for GDB can be installed. The location
3790 of that directory is <data-directory>/python, where <data-directory>
3791 is the GDB data directory. For more details, see section `Scripting
3792 GDB using Python' in the manual.
3794 ** The GDB Python API now has access to breakpoints, symbols, symbol
3795 tables, program spaces, inferiors, threads and frame's code blocks.
3796 Additionally, GDB Parameters can now be created from the API, and
3797 manipulated via set/show in the CLI.
3799 ** New functions gdb.target_charset, gdb.target_wide_charset,
3800 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3802 ** New exception gdb.GdbError.
3804 ** Pretty-printers are now also looked up in the current program space.
3806 ** Pretty-printers can now be individually enabled and disabled.
3808 ** GDB now looks for names of Python scripts to auto-load in a
3809 special section named `.debug_gdb_scripts', in addition to looking
3810 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3812 * Tracepoint actions were unified with breakpoint commands. In particular,
3813 there are no longer differences in "info break" output for breakpoints and
3814 tracepoints and the "commands" command can be used for both tracepoints and
3815 regular breakpoints.
3819 ARM Symbian arm*-*-symbianelf*
3821 * D language support.
3822 GDB now supports debugging programs written in the D programming
3825 * GDB now supports the extended ptrace interface for PowerPC which is
3826 available since Linux kernel version 2.6.34. This automatically enables
3827 any hardware breakpoints and additional hardware watchpoints available in
3828 the processor. The old ptrace interface exposes just one hardware
3829 watchpoint and no hardware breakpoints.
3831 * GDB is now able to use the Data Value Compare (DVC) register available on
3832 embedded PowerPC processors to implement in hardware simple watchpoint
3833 conditions of the form:
3835 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3837 This works in native GDB running on Linux kernels with the extended ptrace
3838 interface mentioned above.
3840 *** Changes in GDB 7.1
3844 ** Namespace Support
3846 GDB now supports importing of namespaces in C++. This enables the
3847 user to inspect variables from imported namespaces. Support for
3848 namepace aliasing has also been added. So, if a namespace is
3849 aliased in the current scope (e.g. namepace C=A; ) the user can
3850 print variables using the alias (e.g. (gdb) print C::x).
3854 All known bugs relating to the printing of virtual base class were
3855 fixed. It is now possible to call overloaded static methods using a
3860 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3861 and reinterpret_cast<> are now handled by the C++ expression parser.
3865 Xilinx MicroBlaze microblaze-*-*
3870 Xilinx MicroBlaze microblaze
3873 * Multi-program debugging.
3875 GDB now has support for multi-program (a.k.a. multi-executable or
3876 multi-exec) debugging. This allows for debugging multiple inferiors
3877 simultaneously each running a different program under the same GDB
3878 session. See "Debugging Multiple Inferiors and Programs" in the
3879 manual for more information. This implied some user visible changes
3880 in the multi-inferior support. For example, "info inferiors" now
3881 lists inferiors that are not running yet or that have exited
3882 already. See also "New commands" and "New options" below.
3884 * New tracing features
3886 GDB's tracepoint facility now includes several new features:
3888 ** Trace state variables
3890 GDB tracepoints now include support for trace state variables, which
3891 are variables managed by the target agent during a tracing
3892 experiment. They are useful for tracepoints that trigger each
3893 other, so for instance one tracepoint can count hits in a variable,
3894 and then a second tracepoint has a condition that is true when the
3895 count reaches a particular value. Trace state variables share the
3896 $-syntax of GDB convenience variables, and can appear in both
3897 tracepoint actions and condition expressions. Use the "tvariable"
3898 command to create, and "info tvariables" to view; see "Trace State
3899 Variables" in the manual for more detail.
3903 GDB now includes an option for defining fast tracepoints, which
3904 targets may implement more efficiently, such as by installing a jump
3905 into the target agent rather than a trap instruction. The resulting
3906 speedup can be by two orders of magnitude or more, although the
3907 tradeoff is that some program locations on some target architectures
3908 might not allow fast tracepoint installation, for instance if the
3909 instruction to be replaced is shorter than the jump. To request a
3910 fast tracepoint, use the "ftrace" command, with syntax identical to
3911 the regular trace command.
3913 ** Disconnected tracing
3915 It is now possible to detach GDB from the target while it is running
3916 a trace experiment, then reconnect later to see how the experiment
3917 is going. In addition, a new variable disconnected-tracing lets you
3918 tell the target agent whether to continue running a trace if the
3919 connection is lost unexpectedly.
3923 GDB now has the ability to save the trace buffer into a file, and
3924 then use that file as a target, similarly to you can do with
3925 corefiles. You can select trace frames, print data that was
3926 collected in them, and use tstatus to display the state of the
3927 tracing run at the moment that it was saved. To create a trace
3928 file, use "tsave <filename>", and to use it, do "target tfile
3931 ** Circular trace buffer
3933 You can ask the target agent to handle the trace buffer as a
3934 circular buffer, discarding the oldest trace frames to make room for
3935 newer ones, by setting circular-trace-buffer to on. This feature may
3936 not be available for all target agents.
3941 The disassemble command, when invoked with two arguments, now requires
3942 the arguments to be comma-separated.
3945 The info variables command now displays variable definitions. Files
3946 which only declare a variable are not shown.
3949 The source command is now capable of sourcing Python scripts.
3950 This feature is dependent on the debugger being build with Python
3953 Related to this enhancement is also the introduction of a new command
3954 "set script-extension" (see below).
3956 * New commands (for set/show, see "New options" below)
3958 record save [<FILENAME>]
3959 Save a file (in core file format) containing the process record
3960 execution log for replay debugging at a later time.
3962 record restore <FILENAME>
3963 Restore the process record execution log that was saved at an
3964 earlier time, for replay debugging.
3966 add-inferior [-copies <N>] [-exec <FILENAME>]
3969 clone-inferior [-copies <N>] [ID]
3970 Make a new inferior ready to execute the same program another
3971 inferior has loaded.
3976 maint info program-spaces
3977 List the program spaces loaded into GDB.
3979 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3980 show remote interrupt-sequence
3981 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3982 as the sequence to the remote target in order to interrupt the execution.
3983 Ctrl-C is a default. Some system prefers BREAK which is high level of
3984 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3985 Magic SysRq g. It is BREAK signal and character 'g'.
3987 set remote interrupt-on-connect [on | off]
3988 show remote interrupt-on-connect
3989 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3990 remote target when gdb connects to it. This is needed when you debug
3993 set remotebreak [on | off]
3995 Deprecated. Use "set/show remote interrupt-sequence" instead.
3997 tvariable $NAME [ = EXP ]
3998 Create or modify a trace state variable.
4001 List trace state variables and their values.
4003 delete tvariable $NAME ...
4004 Delete one or more trace state variables.
4007 Evaluate the given expressions without collecting anything into the
4008 trace buffer. (Valid in tracepoint actions only.)
4010 ftrace FN / FILE:LINE / *ADDR
4011 Define a fast tracepoint at the given function, line, or address.
4013 * New expression syntax
4015 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4016 GDB now parses 0b101010 identically with 42.
4020 set follow-exec-mode new|same
4021 show follow-exec-mode
4022 Control whether GDB reuses the same inferior across an exec call or
4023 creates a new one. This is useful to be able to restart the old
4024 executable after the inferior having done an exec call.
4026 set default-collect EXPR, ...
4027 show default-collect
4028 Define a list of expressions to be collected at each tracepoint.
4029 This is a useful way to ensure essential items are not overlooked,
4030 such as registers or a critical global variable.
4032 set disconnected-tracing
4033 show disconnected-tracing
4034 If set to 1, the target is instructed to continue tracing if it
4035 loses its connection to GDB. If 0, the target is to stop tracing
4038 set circular-trace-buffer
4039 show circular-trace-buffer
4040 If set to on, the target is instructed to use a circular trace buffer
4041 and discard the oldest trace frames instead of stopping the trace due
4042 to a full trace buffer. If set to off, the trace stops when the buffer
4043 fills up. Some targets may not support this.
4045 set script-extension off|soft|strict
4046 show script-extension
4047 If set to "off", the debugger does not perform any script language
4048 recognition, and all sourced files are assumed to be GDB scripts.
4049 If set to "soft" (the default), files are sourced according to
4050 filename extension, falling back to GDB scripts if the first
4052 If set to "strict", files are sourced according to filename extension.
4054 set ada trust-PAD-over-XVS on|off
4055 show ada trust-PAD-over-XVS
4056 If off, activate a workaround against a bug in the debugging information
4057 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4058 the GCC sources for more information about the GNAT encoding and
4059 PAD types in particular). It is always safe to set this option to
4060 off, but this introduces a slight performance penalty. The default
4063 * Python API Improvements
4065 ** GDB provides the new class gdb.LazyString. This is useful in
4066 some pretty-printing cases. The new method gdb.Value.lazy_string
4067 provides a simple way to create objects of this type.
4069 ** The fields returned by gdb.Type.fields now have an
4070 `is_base_class' attribute.
4072 ** The new method gdb.Type.range returns the range of an array type.
4074 ** The new method gdb.parse_and_eval can be used to parse and
4075 evaluate an expression.
4077 * New remote packets
4080 Define a trace state variable.
4083 Get the current value of a trace state variable.
4086 Set desired tracing behavior upon disconnection.
4089 Set the trace buffer to be linear or circular.
4092 Get data about the tracepoints currently in use.
4096 Process record now works correctly with hardware watchpoints.
4098 Multiple bug fixes have been made to the mips-irix port, making it
4099 much more reliable. In particular:
4100 - Debugging threaded applications is now possible again. Previously,
4101 GDB would hang while starting the program, or while waiting for
4102 the program to stop at a breakpoint.
4103 - Attaching to a running process no longer hangs.
4104 - An error occurring while loading a core file has been fixed.
4105 - Changing the value of the PC register now works again. This fixes
4106 problems observed when using the "jump" command, or when calling
4107 a function from GDB, or even when assigning a new value to $pc.
4108 - With the "finish" and "return" commands, the return value for functions
4109 returning a small array is now correctly printed.
4110 - It is now possible to break on shared library code which gets executed
4111 during a shared library init phase (code executed while executing
4112 their .init section). Previously, the breakpoint would have no effect.
4113 - GDB is now able to backtrace through the signal handler for
4114 non-threaded programs.
4116 PIE (Position Independent Executable) programs debugging is now supported.
4117 This includes debugging execution of PIC (Position Independent Code) shared
4118 libraries although for that, it should be possible to run such libraries as an
4121 *** Changes in GDB 7.0
4123 * GDB now has an interface for JIT compilation. Applications that
4124 dynamically generate code can create symbol files in memory and register
4125 them with GDB. For users, the feature should work transparently, and
4126 for JIT developers, the interface is documented in the GDB manual in the
4127 "JIT Compilation Interface" chapter.
4129 * Tracepoints may now be conditional. The syntax is as for
4130 breakpoints; either an "if" clause appended to the "trace" command,
4131 or the "condition" command is available. GDB sends the condition to
4132 the target for evaluation using the same bytecode format as is used
4133 for tracepoint actions.
4135 * The disassemble command now supports: an optional /r modifier, print the
4136 raw instructions in hex as well as in symbolic form, and an optional /m
4137 modifier to print mixed source+assembly.
4139 * Process record and replay
4141 In a architecture environment that supports ``process record and
4142 replay'', ``process record and replay'' target can record a log of
4143 the process execution, and replay it with both forward and reverse
4146 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4147 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4148 set execution-direction {forward|reverse}, for targets that support
4151 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4152 feature is available with a native GDB running on kernel version
4155 * GDB now has support for multi-byte and wide character sets on the
4156 target. Strings whose character type is wchar_t, char16_t, or
4157 char32_t are now correctly printed. GDB supports wide- and unicode-
4158 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4159 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4160 `printf'. This feature requires iconv to work properly; if your
4161 system does not have a working iconv, GDB can use GNU libiconv. See
4162 the installation instructions for more information.
4164 * GDB now supports automatic retrieval of shared library files from
4165 remote targets. To use this feature, specify a system root that begins
4166 with the `remote:' prefix, either via the `set sysroot' command or via
4167 the `--with-sysroot' configure-time option.
4169 * "info sharedlibrary" now takes an optional regex of libraries to show,
4170 and it now reports if a shared library has no debugging information.
4172 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4173 now complete on file names.
4175 * When completing in expressions, gdb will attempt to limit
4176 completions to allowable structure or union fields, where appropriate.
4177 For instance, consider:
4179 # struct example { int f1; double f2; };
4180 # struct example variable;
4183 If the user types TAB at the end of this command line, the available
4184 completions will be "f1" and "f2".
4186 * Inlined functions are now supported. They show up in backtraces, and
4187 the "step", "next", and "finish" commands handle them automatically.
4189 * GDB now supports the token-splicing (##) and stringification (#)
4190 operators when expanding macros. It also supports variable-arity
4193 * GDB now supports inspecting extra signal information, exported by
4194 the new $_siginfo convenience variable. The feature is currently
4195 implemented on linux ARM, i386 and amd64.
4197 * GDB can now display the VFP floating point registers and NEON vector
4198 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4199 can provide these registers (requires Linux 2.6.30 or later). Remote
4200 and simulator targets may also provide them.
4202 * New remote packets
4205 Search memory for a sequence of bytes.
4208 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4209 operation over reliable transport links. Use of this packet is
4210 controlled by the `set remote noack-packet' command.
4213 Kill the process with the specified process ID. Use this in preference
4214 to `k' when multiprocess protocol extensions are supported.
4217 Obtains additional operating system information
4221 Read or write additional signal information.
4223 * Removed remote protocol undocumented extension
4225 An undocumented extension to the remote protocol's `S' stop reply
4226 packet that permited the stub to pass a process id was removed.
4227 Remote servers should use the `T' stop reply packet instead.
4229 * GDB now supports multiple function calling conventions according to the
4230 DWARF-2 DW_AT_calling_convention function attribute.
4232 * The SH target utilizes the aforementioned change to distinguish between gcc
4233 and Renesas calling convention. It also adds the new CLI commands
4234 `set/show sh calling-convention'.
4236 * GDB can now read compressed debug sections, as produced by GNU gold
4237 with the --compress-debug-sections=zlib flag.
4239 * 64-bit core files are now supported on AIX.
4241 * Thread switching is now supported on Tru64.
4243 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4244 which will be allocated using malloc later in program execution.
4246 * The qXfer:libraries:read remote procotol packet now allows passing a
4247 list of section offsets.
4249 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4250 conditions handling signals delivered during attach or thread creation
4251 have also been fixed.
4253 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4254 From the user's standpoint, all unqualified instances of True and False
4255 are treated as the standard definitions, regardless of context.
4257 * GDB now parses C++ symbol and type names more flexibly. For
4260 template<typename T> class C { };
4263 GDB will now correctly handle all of:
4265 ptype C<char const *>
4266 ptype C<char const*>
4267 ptype C<const char *>
4268 ptype C<const char*>
4270 * New features in the GDB remote stub, gdbserver
4272 - The "--wrapper" command-line argument tells gdbserver to use a
4273 wrapper program to launch programs for debugging.
4275 - On PowerPC and S/390 targets, it is now possible to use a single
4276 gdbserver executable to debug both 32-bit and 64-bit programs.
4277 (This requires gdbserver itself to be built as a 64-bit executable.)
4279 - gdbserver uses the new noack protocol mode for TCP connections to
4280 reduce communications latency, if also supported and enabled in GDB.
4282 - Support for the sparc64-linux-gnu target is now included in
4285 - The amd64-linux build of gdbserver now supports debugging both
4286 32-bit and 64-bit programs.
4288 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4289 now support hardware watchpoints, and will use them automatically
4294 GDB now has support for scripting using Python. Whether this is
4295 available is determined at configure time.
4297 New GDB commands can now be written in Python.
4299 * Ada tasking support
4301 Ada tasks can now be inspected in GDB. The following commands have
4305 Print the list of Ada tasks.
4307 Print detailed information about task number N.
4309 Print the task number of the current task.
4311 Switch the context of debugging to task number N.
4313 * Support for user-defined prefixed commands. The "define" command can
4314 add new commands to existing prefixes, e.g. "target".
4316 * Multi-inferior, multi-process debugging.
4318 GDB now has generalized support for multi-inferior debugging. See
4319 "Debugging Multiple Inferiors" in the manual for more information.
4320 Although availability still depends on target support, the command
4321 set is more uniform now. The GNU/Linux specific multi-forks support
4322 has been migrated to this new framework. This implied some user
4323 visible changes; see "New commands" and also "Removed commands"
4326 * Target descriptions can now describe the target OS ABI. See the
4327 "Target Description Format" section in the user manual for more
4330 * Target descriptions can now describe "compatible" architectures
4331 to indicate that the target can execute applications for a different
4332 architecture in addition to those for the main target architecture.
4333 See the "Target Description Format" section in the user manual for
4336 * Multi-architecture debugging.
4338 GDB now includes general supports for debugging applications on
4339 hybrid systems that use more than one single processor architecture
4340 at the same time. Each such hybrid architecture still requires
4341 specific support to be added. The only hybrid architecture supported
4342 in this version of GDB is the Cell Broadband Engine.
4344 * GDB now supports integrated debugging of Cell/B.E. applications that
4345 use both the PPU and SPU architectures. To enable support for hybrid
4346 Cell/B.E. debugging, you need to configure GDB to support both the
4347 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4348 --enable-targets configure option.
4350 * Non-stop mode debugging.
4352 For some targets, GDB now supports an optional mode of operation in
4353 which you can examine stopped threads while other threads continue
4354 to execute freely. This is referred to as non-stop mode, with the
4355 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4356 section in the user manual for more information.
4358 To be able to support remote non-stop debugging, a remote stub needs
4359 to implement the non-stop mode remote protocol extensions, as
4360 described in the "Remote Non-Stop" section of the user manual. The
4361 GDB remote stub, gdbserver, has been adjusted to support these
4362 extensions on linux targets.
4364 * New commands (for set/show, see "New options" below)
4366 catch syscall [NAME(S) | NUMBER(S)]
4367 Catch system calls. Arguments, which should be names of system
4368 calls or their numbers, mean catch only those syscalls. Without
4369 arguments, every syscall will be caught. When the inferior issues
4370 any of the specified syscalls, GDB will stop and announce the system
4371 call, both when it is called and when its call returns. This
4372 feature is currently available with a native GDB running on the
4373 Linux Kernel, under the following architectures: x86, x86_64,
4374 PowerPC and PowerPC64.
4376 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4378 Search memory for a sequence of bytes.
4380 maint set python print-stack
4381 maint show python print-stack
4382 Show a stack trace when an error is encountered in a Python script.
4385 Invoke CODE by passing it to the Python interpreter.
4390 These allow macros to be defined, undefined, and listed
4394 Show operating system information about processes.
4397 List the inferiors currently under GDB's control.
4400 Switch focus to inferior number NUM.
4403 Detach from inferior number NUM.
4406 Kill inferior number NUM.
4410 set spu stop-on-load
4411 show spu stop-on-load
4412 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4414 set spu auto-flush-cache
4415 show spu auto-flush-cache
4416 Control whether to automatically flush the software-managed cache
4417 during Cell/B.E. debugging.
4419 set sh calling-convention
4420 show sh calling-convention
4421 Control the calling convention used when calling SH target functions.
4424 show debug timestamp
4425 Control display of timestamps with GDB debugging output.
4427 set disassemble-next-line
4428 show disassemble-next-line
4429 Control display of disassembled source lines or instructions when
4432 set remote noack-packet
4433 show remote noack-packet
4434 Set/show the use of remote protocol QStartNoAckMode packet. See above
4435 under "New remote packets."
4437 set remote query-attached-packet
4438 show remote query-attached-packet
4439 Control use of remote protocol `qAttached' (query-attached) packet.
4441 set remote read-siginfo-object
4442 show remote read-siginfo-object
4443 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4446 set remote write-siginfo-object
4447 show remote write-siginfo-object
4448 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4451 set remote reverse-continue
4452 show remote reverse-continue
4453 Control use of remote protocol 'bc' (reverse-continue) packet.
4455 set remote reverse-step
4456 show remote reverse-step
4457 Control use of remote protocol 'bs' (reverse-step) packet.
4459 set displaced-stepping
4460 show displaced-stepping
4461 Control displaced stepping mode. Displaced stepping is a way to
4462 single-step over breakpoints without removing them from the debuggee.
4463 Also known as "out-of-line single-stepping".
4466 show debug displaced
4467 Control display of debugging info for displaced stepping.
4469 maint set internal-error
4470 maint show internal-error
4471 Control what GDB does when an internal error is detected.
4473 maint set internal-warning
4474 maint show internal-warning
4475 Control what GDB does when an internal warning is detected.
4480 Use a wrapper program to launch programs for debugging.
4482 set multiple-symbols (all|ask|cancel)
4483 show multiple-symbols
4484 The value of this variable can be changed to adjust the debugger behavior
4485 when an expression or a breakpoint location contains an ambiguous symbol
4486 name (an overloaded function name, for instance).
4488 set breakpoint always-inserted
4489 show breakpoint always-inserted
4490 Keep breakpoints always inserted in the target, as opposed to inserting
4491 them when resuming the target, and removing them when the target stops.
4492 This option can improve debugger performance on slow remote targets.
4494 set arm fallback-mode (arm|thumb|auto)
4495 show arm fallback-mode
4496 set arm force-mode (arm|thumb|auto)
4498 These commands control how ARM GDB determines whether instructions
4499 are ARM or Thumb. The default for both settings is auto, which uses
4500 the current CPSR value for instructions without symbols; previous
4501 versions of GDB behaved as if "set arm fallback-mode arm".
4503 set disable-randomization
4504 show disable-randomization
4505 Standalone programs run with the virtual address space randomization enabled
4506 by default on some platforms. This option keeps the addresses stable across
4507 multiple debugging sessions.
4511 Control whether other threads are stopped or not when some thread hits
4516 Requests that asynchronous execution is enabled in the target, if available.
4517 In this case, it's possible to resume target in the background, and interact
4518 with GDB while the target is running. "show target-async" displays the
4519 current state of asynchronous execution of the target.
4521 set target-wide-charset
4522 show target-wide-charset
4523 The target-wide-charset is the name of the character set that GDB
4524 uses when printing characters whose type is wchar_t.
4526 set tcp auto-retry (on|off)
4528 set tcp connect-timeout
4529 show tcp connect-timeout
4530 These commands allow GDB to retry failed TCP connections to a remote stub
4531 with a specified timeout period; this is useful if the stub is launched
4532 in parallel with GDB but may not be ready to accept connections immediately.
4534 set libthread-db-search-path
4535 show libthread-db-search-path
4536 Control list of directories which GDB will search for appropriate
4539 set schedule-multiple (on|off)
4540 show schedule-multiple
4541 Allow GDB to resume all threads of all processes or only threads of
4542 the current process.
4546 Use more aggressive caching for accesses to the stack. This improves
4547 performance of remote debugging (particularly backtraces) without
4548 affecting correctness.
4550 set interactive-mode (on|off|auto)
4551 show interactive-mode
4552 Control whether GDB runs in interactive mode (on) or not (off).
4553 When in interactive mode, GDB waits for the user to answer all
4554 queries. Otherwise, GDB does not wait and assumes the default
4555 answer. When set to auto (the default), GDB determines which
4556 mode to use based on the stdin settings.
4561 For program forks, this is replaced by the new more generic `info
4562 inferiors' command. To list checkpoints, you can still use the
4563 `info checkpoints' command, which was an alias for the `info forks'
4567 Replaced by the new `inferior' command. To switch between
4568 checkpoints, you can still use the `restart' command, which was an
4569 alias for the `fork' command.
4572 This is removed, since some targets don't have a notion of
4573 processes. To switch between processes, you can still use the
4574 `inferior' command using GDB's own inferior number.
4577 For program forks, this is replaced by the new more generic `kill
4578 inferior' command. To delete a checkpoint, you can still use the
4579 `delete checkpoint' command, which was an alias for the `delete
4583 For program forks, this is replaced by the new more generic `detach
4584 inferior' command. To detach a checkpoint, you can still use the
4585 `detach checkpoint' command, which was an alias for the `detach
4588 * New native configurations
4590 x86/x86_64 Darwin i[34567]86-*-darwin*
4592 x86_64 MinGW x86_64-*-mingw*
4596 Lattice Mico32 lm32-*
4597 x86 DICOS i[34567]86-*-dicos*
4598 x86_64 DICOS x86_64-*-dicos*
4601 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4602 (mingw32ce) debugging.
4608 These commands were actually not implemented on any target.
4610 *** Changes in GDB 6.8
4612 * New native configurations
4614 NetBSD/hppa hppa*-*netbsd*
4615 Xtensa GNU/Linux xtensa*-*-linux*
4619 NetBSD/hppa hppa*-*-netbsd*
4620 Xtensa GNU/Lunux xtensa*-*-linux*
4622 * Change in command line behavior -- corefiles vs. process ids.
4624 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4625 attaching to process NUMBER fails, GDB no longer attempts to open a
4626 core file named NUMBER. Attaching to a program using the -c option
4627 is no longer supported. Instead, use the '-p' or '--pid' options.
4629 * GDB can now be built as a native debugger for debugging Windows x86
4630 (mingw32) Portable Executable (PE) programs.
4632 * Pending breakpoints no longer change their number when their address
4635 * GDB now supports breakpoints with multiple locations,
4636 including breakpoints on C++ constructors, inside C++ templates,
4637 and in inlined functions.
4639 * GDB's ability to debug optimized code has been improved. GDB more
4640 accurately identifies function bodies and lexical blocks that occupy
4641 more than one contiguous range of addresses.
4643 * Target descriptions can now describe registers for PowerPC.
4645 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4646 registers on PowerPC targets.
4648 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4649 targets even when the libthread_db library is not available.
4651 * The GDB remote stub, gdbserver, now supports the new file transfer
4652 commands (remote put, remote get, and remote delete).
4654 * The GDB remote stub, gdbserver, now supports run and attach in
4655 extended-remote mode.
4657 * hppa*64*-*-hpux11* target broken
4658 The debugger is unable to start a program and fails with the following
4659 error: "Error trying to get information about dynamic linker".
4660 The gdb-6.7 release is also affected.
4662 * GDB now supports the --enable-targets= configure option to allow
4663 building a single GDB executable that supports multiple remote
4664 target architectures.
4666 * GDB now supports debugging C and C++ programs which use the
4667 Decimal Floating Point extension. In addition, the PowerPC target
4668 now has a set of pseudo-registers to inspect decimal float values
4669 stored in two consecutive float registers.
4671 * The -break-insert MI command can optionally create pending
4674 * Improved support for debugging Ada
4675 Many improvements to the Ada language support have been made. These
4677 - Better support for Ada2005 interface types
4678 - Improved handling of arrays and slices in general
4679 - Better support for Taft-amendment types
4680 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4682 - Improved command completion in Ada
4685 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4690 set print frame-arguments (all|scalars|none)
4691 show print frame-arguments
4692 The value of this variable can be changed to control which argument
4693 values should be printed by the debugger when displaying a frame.
4698 Transfer files to and from a remote target, and delete remote files.
4705 Transfer files to and from a remote target, and delete remote files.
4707 * New remote packets
4714 Open, close, read, write, and delete files on the remote system.
4717 Attach to an existing process on the remote system, in extended-remote
4721 Run a new process on the remote system, in extended-remote mode.
4723 *** Changes in GDB 6.7
4725 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4726 bfd, libiberty and opcodes, as revealed by static analysis donated by
4727 Coverity, Inc. (http://scan.coverity.com).
4729 * When looking up multiply-defined global symbols, GDB will now prefer the
4730 symbol definition in the current shared library if it was built using the
4731 -Bsymbolic linker option.
4733 * When the Text User Interface (TUI) is not configured, GDB will now
4734 recognize the -tui command-line option and print a message that the TUI
4737 * The GDB remote stub, gdbserver, now has lower overhead for high
4738 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4740 * GDB for MIPS targets now autodetects whether a remote target provides
4741 32-bit or 64-bit register values.
4743 * Support for C++ member pointers has been improved.
4745 * GDB now understands XML target descriptions, which specify the
4746 target's overall architecture. GDB can read a description from
4747 a local file or over the remote serial protocol.
4749 * Vectors of single-byte data use a new integer type which is not
4750 automatically displayed as character or string data.
4752 * The /s format now works with the print command. It displays
4753 arrays of single-byte integers and pointers to single-byte integers
4756 * Target descriptions can now describe target-specific registers,
4757 for architectures which have implemented the support (currently
4758 only ARM, M68K, and MIPS).
4760 * GDB and the GDB remote stub, gdbserver, now support the XScale
4763 * The GDB remote stub, gdbserver, has been updated to support
4764 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4765 has been rewritten to use the standard GDB remote protocol.
4767 * GDB can now step into C++ functions which are called through thunks.
4769 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4771 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4772 layout. It also supports a TextSeg= and DataSeg= response when only
4773 segment base addresses (rather than offsets) are available.
4775 * The /i format now outputs any trailing branch delay slot instructions
4776 immediately following the last instruction within the count specified.
4778 * The GDB remote protocol "T" stop reply packet now supports a
4779 "library" response. Combined with the new "qXfer:libraries:read"
4780 packet, this response allows GDB to debug shared libraries on targets
4781 where the operating system manages the list of loaded libraries (e.g.
4782 Windows and SymbianOS).
4784 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4785 (DLLs) on Windows and Windows CE targets.
4787 * GDB now supports a faster verification that a .debug file matches its binary
4788 according to its build-id signature, if the signature is present.
4794 Enable or disable hardware flow control (RTS/CTS) on the serial port
4795 when debugging using remote targets.
4797 set mem inaccessible-by-default
4798 show mem inaccessible-by-default
4799 If the target supplies a memory map, for instance via the remote
4800 protocol's "qXfer:memory-map:read" packet, setting this variable
4801 prevents GDB from accessing memory outside the memory map. This
4802 is useful for targets with memory mapped registers or which react
4803 badly to accesses of unmapped address space.
4805 set breakpoint auto-hw
4806 show breakpoint auto-hw
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 lets GDB use hardware breakpoints automatically for memory regions
4810 where it can not use software breakpoints. This covers both the
4811 "break" command and internal breakpoints used for other commands
4812 including "next" and "finish".
4815 catch exception unhandled
4816 Stop the program execution when Ada exceptions are raised.
4819 Stop the program execution when an Ada assertion failed.
4823 Set an alternate system root for target files. This is a more
4824 general version of "set solib-absolute-prefix", which is now
4825 an alias to "set sysroot".
4828 Provide extended SPU facility status information. This set of
4829 commands is available only when debugging the Cell/B.E. SPU
4832 * New native configurations
4834 OpenBSD/sh sh*-*openbsd*
4837 unset tdesc filename
4839 Use the specified local file as an XML target description, and do
4840 not query the target for its built-in description.
4844 OpenBSD/sh sh*-*-openbsd*
4845 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4846 Toshiba Media Processor mep-elf
4848 * New remote packets
4851 Ignore the specified signals; pass them directly to the debugged program
4852 without stopping other threads or reporting them to GDB.
4854 qXfer:features:read:
4855 Read an XML target description from the target, which describes its
4860 Read or write contents of an spufs file on the target system. These
4861 packets are available only on the Cell/B.E. SPU architecture.
4863 qXfer:libraries:read:
4864 Report the loaded shared libraries. Combined with new "T" packet
4865 response, this packet allows GDB to debug shared libraries on
4866 targets where the operating system manages the list of loaded
4867 libraries (e.g. Windows and SymbianOS).
4871 Support for these obsolete configurations has been removed.
4879 i[34567]86-*-lynxos*
4880 i[34567]86-*-netware*
4881 i[34567]86-*-sco3.2v5*
4882 i[34567]86-*-sco3.2v4*
4884 i[34567]86-*-sysv4.2*
4887 i[34567]86-*-unixware2*
4888 i[34567]86-*-unixware*
4897 * Other removed features
4904 Various m68k-only ROM monitors.
4911 Various Renesas ROM monitors and debugging interfaces for SH and
4916 Support for a Macraigor serial interface to on-chip debugging.
4917 GDB does not directly support the newer parallel or USB
4922 A debug information format. The predecessor to DWARF 2 and
4923 DWARF 3, which are still supported.
4925 Support for the HP aCC compiler on HP-UX/PA-RISC
4927 SOM-encapsulated symbolic debugging information, automatic
4928 invocation of pxdb, and the aCC custom C++ ABI. This does not
4929 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4930 with aCC can still be debugged on an assembly level.
4932 MIPS ".pdr" sections
4934 A MIPS-specific format used to describe stack frame layout
4935 in debugging information.
4939 GDB could work with an older version of Guile to debug
4940 the interpreter and Scheme programs running in it.
4942 set mips stack-arg-size
4943 set mips saved-gpreg-size
4945 Use "set mips abi" to control parameter passing for MIPS.
4947 *** Changes in GDB 6.6
4952 Cell Broadband Engine SPU spu-elf
4954 * GDB can now be configured as a cross-debugger targeting native Windows
4955 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4956 running on a Windows system over TCP/IP to debug Windows programs.
4958 * The GDB remote stub, gdbserver, has been updated to support Windows and
4959 Cygwin debugging. Both single-threaded and multi-threaded programs are
4962 * The "set trust-readonly-sections" command works again. This command was
4963 broken in GDB 6.3, 6.4, and 6.5.
4965 * The "load" command now supports writing to flash memory, if the remote
4966 stub provides the required support.
4968 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4969 longer requires symbolic debug information (e.g. DWARF-2).
4974 unset substitute-path
4975 show substitute-path
4976 Manage a list of substitution rules that GDB uses to rewrite the name
4977 of the directories where the sources are located. This can be useful
4978 for instance when the sources were moved to a different location
4979 between compilation and debugging.
4983 Print each CLI command as it is executed. Each command is prefixed with
4984 a number of `+' symbols representing the nesting depth.
4985 The source command now has a `-v' option to enable the same feature.
4989 The ARM Demon monitor support (RDP protocol, "target rdp").
4991 Kernel Object Display, an embedded debugging feature which only worked with
4992 an obsolete version of Cisco IOS.
4994 The 'set download-write-size' and 'show download-write-size' commands.
4996 * New remote packets
4999 Tell a stub about GDB client features, and request remote target features.
5000 The first feature implemented is PacketSize, which allows the target to
5001 specify the size of packets it can handle - to minimize the number of
5002 packets required and improve performance when connected to a remote
5006 Fetch an OS auxilliary vector from the remote stub. This packet is a
5007 more efficient replacement for qPart:auxv:read.
5009 qXfer:memory-map:read:
5010 Fetch a memory map from the remote stub, including information about
5011 RAM, ROM, and flash memory devices.
5016 Erase and program a flash memory device.
5018 * Removed remote packets
5021 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5022 used it, and only gdbserver implemented it.
5024 *** Changes in GDB 6.5
5028 Renesas M32C/M16C m32c-elf
5030 Morpho Technologies ms1 ms1-elf
5034 init-if-undefined Initialize a convenience variable, but
5035 only if it doesn't already have a value.
5037 The following commands are presently only implemented for native GNU/Linux:
5039 checkpoint Save a snapshot of the program state.
5041 restart <n> Return the program state to a
5042 previously saved state.
5044 info checkpoints List currently saved checkpoints.
5046 delete-checkpoint <n> Delete a previously saved checkpoint.
5048 set|show detach-on-fork Tell gdb whether to detach from a newly
5049 forked process, or to keep debugging it.
5051 info forks List forks of the user program that
5052 are available to be debugged.
5054 fork <n> Switch to debugging one of several
5055 forks of the user program that are
5056 available to be debugged.
5058 delete-fork <n> Delete a fork from the list of forks
5059 that are available to be debugged (and
5060 kill the forked process).
5062 detach-fork <n> Delete a fork from the list of forks
5063 that are available to be debugged (and
5064 allow the process to continue).
5068 Morpho Technologies ms2 ms1-elf
5070 * Improved Windows host support
5072 GDB now builds as a cross debugger hosted on i686-mingw32, including
5073 native console support, and remote communications using either
5074 network sockets or serial ports.
5076 * Improved Modula-2 language support
5078 GDB can now print most types in the Modula-2 syntax. This includes:
5079 basic types, set types, record types, enumerated types, range types,
5080 pointer types and ARRAY types. Procedure var parameters are correctly
5081 printed and hexadecimal addresses and character constants are also
5082 written in the Modula-2 syntax. Best results can be obtained by using
5083 GNU Modula-2 together with the -gdwarf-2 command line option.
5087 The ARM rdi-share module.
5089 The Netware NLM debug server.
5091 *** Changes in GDB 6.4
5093 * New native configurations
5095 OpenBSD/arm arm*-*-openbsd*
5096 OpenBSD/mips64 mips64-*-openbsd*
5100 Morpho Technologies ms1 ms1-elf
5102 * New command line options
5104 --batch-silent As for --batch, but totally silent.
5105 --return-child-result The debugger will exist with the same value
5106 the child (debugged) program exited with.
5107 --eval-command COMMAND, -ex COMMAND
5108 Execute a single GDB CLI command. This may be
5109 specified multiple times and in conjunction
5110 with the --command (-x) option.
5112 * Deprecated commands removed
5114 The following commands, that were deprecated in 2000, have been
5118 set|show arm disassembly-flavor set|show arm disassembler
5119 othernames set arm disassembler
5120 set|show remotedebug set|show debug remote
5121 set|show archdebug set|show debug arch
5122 set|show eventdebug set|show debug event
5125 * New BSD user-level threads support
5127 It is now possible to debug programs using the user-level threads
5128 library on OpenBSD and FreeBSD. Currently supported (target)
5131 FreeBSD/amd64 x86_64-*-freebsd*
5132 FreeBSD/i386 i386-*-freebsd*
5133 OpenBSD/i386 i386-*-openbsd*
5135 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5136 are not yet supported.
5138 * New support for Matsushita MN10300 w/sim added
5139 (Work in progress). mn10300-elf.
5141 * REMOVED configurations and files
5143 VxWorks and the XDR protocol *-*-vxworks
5144 Motorola MCORE mcore-*-*
5145 National Semiconductor NS32000 ns32k-*-*
5147 * New "set print array-indexes" command
5149 After turning this setting "on", GDB prints the index of each element
5150 when displaying arrays. The default is "off" to preserve the previous
5153 * VAX floating point support
5155 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5157 * User-defined command support
5159 In addition to using $arg0..$arg9 for argument passing, it is now possible
5160 to use $argc to determine now many arguments have been passed. See the
5161 section on user-defined commands in the user manual for more information.
5163 *** Changes in GDB 6.3:
5165 * New command line option
5167 GDB now accepts -l followed by a number to set the timeout for remote
5170 * GDB works with GCC -feliminate-dwarf2-dups
5172 GDB now supports a more compact representation of DWARF-2 debug
5173 information using DW_FORM_ref_addr references. These are produced
5174 by GCC with the option -feliminate-dwarf2-dups and also by some
5175 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5176 to use -feliminate-dwarf2-dups.
5178 * Internationalization
5180 When supported by the host system, GDB will be built with
5181 internationalization (libintl). The task of marking up the sources is
5182 continued, we're looking forward to our first translation.
5186 Initial support for debugging programs compiled with the GNAT
5187 implementation of the Ada programming language has been integrated
5188 into GDB. In this release, support is limited to expression evaluation.
5190 * New native configurations
5192 GNU/Linux/m32r m32r-*-linux-gnu
5196 GDB's remote protocol now includes support for the 'p' packet. This
5197 packet is used to fetch individual registers from a remote inferior.
5199 * END-OF-LIFE registers[] compatibility module
5201 GDB's internal register infrastructure has been completely rewritten.
5202 The new infrastructure making possible the implementation of key new
5203 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5206 GDB 6.3 will be the last release to include the registers[]
5207 compatibility module that allowed out-of-date configurations to
5208 continue to work. This change directly impacts the following
5218 powerpc bdm protocol
5220 Unless there is activity to revive these configurations, they will be
5221 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5223 * OBSOLETE configurations and files
5225 Configurations that have been declared obsolete in this release have
5226 been commented out. Unless there is activity to revive these
5227 configurations, the next release of GDB will have their sources
5228 permanently REMOVED.
5237 *** Changes in GDB 6.2.1:
5239 * MIPS `break main; run' gave an heuristic-fence-post warning
5241 When attempting to run even a simple program, a warning about
5242 heuristic-fence-post being hit would be reported. This problem has
5245 * MIPS IRIX 'long double' crashed GDB
5247 When examining a long double variable, GDB would get a segmentation
5248 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5249 IRIX long double values).
5253 A bug in the VAX stack code was causing problems with the "next"
5254 command. This problem has been fixed.
5256 *** Changes in GDB 6.2:
5258 * Fix for ``many threads''
5260 On GNU/Linux systems that use the NPTL threads library, a program
5261 rapidly creating and deleting threads would confuse GDB leading to the
5264 ptrace: No such process.
5265 thread_db_get_info: cannot get thread info: generic error
5267 This problem has been fixed.
5269 * "-async" and "-noasync" options removed.
5271 Support for the broken "-noasync" option has been removed (it caused
5274 * New ``start'' command.
5276 This command runs the program until the begining of the main procedure.
5278 * New BSD Kernel Data Access Library (libkvm) interface
5280 Using ``target kvm'' it is now possible to debug kernel core dumps and
5281 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5282 platforms. Currently supported (native-only) configurations are:
5284 FreeBSD/amd64 x86_64-*-freebsd*
5285 FreeBSD/i386 i?86-*-freebsd*
5286 NetBSD/i386 i?86-*-netbsd*
5287 NetBSD/m68k m68*-*-netbsd*
5288 NetBSD/sparc sparc-*-netbsd*
5289 OpenBSD/amd64 x86_64-*-openbsd*
5290 OpenBSD/i386 i?86-*-openbsd*
5291 OpenBSD/m68k m68*-openbsd*
5292 OpenBSD/sparc sparc-*-openbsd*
5294 * Signal trampoline code overhauled
5296 Many generic problems with GDB's signal handling code have been fixed.
5297 These include: backtraces through non-contiguous stacks; recognition
5298 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5299 call; backtrace through a signal trampoline; step into and out of
5300 signal handlers; and single-stepping in the signal trampoline.
5302 Please note that kernel bugs are a limiting factor here. These
5303 features have been shown to work on an s390 GNU/Linux system that
5304 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5306 * Cygwin support for DWARF 2 added.
5308 * New native configurations
5310 GNU/Linux/hppa hppa*-*-linux*
5311 OpenBSD/hppa hppa*-*-openbsd*
5312 OpenBSD/m68k m68*-*-openbsd*
5313 OpenBSD/m88k m88*-*-openbsd*
5314 OpenBSD/powerpc powerpc-*-openbsd*
5315 NetBSD/vax vax-*-netbsd*
5316 OpenBSD/vax vax-*-openbsd*
5318 * END-OF-LIFE frame compatibility module
5320 GDB's internal frame infrastructure has been completely rewritten.
5321 The new infrastructure making it possible to support key new features
5322 including DWARF 2 Call Frame Information. To aid in the task of
5323 migrating old configurations to this new infrastructure, a
5324 compatibility module, that allowed old configurations to continue to
5325 work, was also included.
5327 GDB 6.2 will be the last release to include this frame compatibility
5328 module. This change directly impacts the following configurations:
5338 Unless there is activity to revive these configurations, they will be
5339 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5341 * REMOVED configurations and files
5343 Sun 3, running SunOS 3 m68*-*-sunos3*
5344 Sun 3, running SunOS 4 m68*-*-sunos4*
5345 Sun 2, running SunOS 3 m68000-*-sunos3*
5346 Sun 2, running SunOS 4 m68000-*-sunos4*
5347 Motorola 680x0 running LynxOS m68*-*-lynxos*
5348 AT&T 3b1/Unix pc m68*-att-*
5349 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5350 decstation mips-dec-* mips-little-*
5351 riscos mips-*-riscos* mips-*-sysv*
5352 sonymips mips-sony-*
5353 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5355 *** Changes in GDB 6.1.1:
5357 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5359 The TUI (Text-mode User Interface) is now built as part of a default
5360 GDB configuration. It is enabled by either selecting the TUI with the
5361 command line option "-i=tui" or by running the separate "gdbtui"
5362 program. For more information on the TUI, see the manual "Debugging
5365 * Pending breakpoint support (also included in GDB 6.1)
5367 Support has been added to allow you to specify breakpoints in shared
5368 libraries that have not yet been loaded. If a breakpoint location
5369 cannot be found, and the "breakpoint pending" option is set to auto,
5370 GDB queries you if you wish to make the breakpoint pending on a future
5371 shared-library load. If and when GDB resolves the breakpoint symbol,
5372 the pending breakpoint is removed as one or more regular breakpoints
5375 Pending breakpoints are very useful for GCJ Java debugging.
5377 * Fixed ISO-C build problems
5379 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5380 non ISO-C code that stopped them being built using a more strict ISO-C
5381 compiler (e.g., IBM's C compiler).
5383 * Fixed build problem on IRIX 5
5385 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5386 wasn't able to compile compile on an IRIX 5 system.
5388 * Added execute permission to gdb/gdbserver/configure
5390 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5391 permission. This bug would cause configure to fail on a number of
5392 systems (Solaris, IRIX). Ref: server/519.
5394 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5396 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5397 has been updated to use constant array sizes.
5399 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5401 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5402 its generated DWARF Call Frame Info. This encoding was causing GDB to
5403 panic, that panic has been fixed. Ref: gdb/1628.
5405 * Fixed a problem when examining parameters in shared library code.
5407 When examining parameters in optimized shared library code generated
5408 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5409 not available''. GDB now correctly displays the variable's value.
5411 *** Changes in GDB 6.1:
5413 * Removed --with-mmalloc
5415 Support for the mmalloc memory manager has been removed, as it
5416 conflicted with the internal gdb byte cache.
5418 * Changes in AMD64 configurations
5420 The AMD64 target now includes the %cs and %ss registers. As a result
5421 the AMD64 remote protocol has changed; this affects the floating-point
5422 and SSE registers. If you rely on those registers for your debugging,
5423 you should upgrade gdbserver on the remote side.
5425 * Revised SPARC target
5427 The SPARC target has been completely revised, incorporating the
5428 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5429 support for LynxOS and SunOS 4 has been dropped. Calling functions
5430 from within GDB on operating systems with a non-executable stack
5431 (Solaris, OpenBSD) now works.
5435 GDB has a new C++ demangler which does a better job on the mangled
5436 names generated by current versions of g++. It also runs faster, so
5437 with this and other changes gdb should now start faster on large C++
5440 * DWARF 2 Location Expressions
5442 GDB support for location expressions has been extended to support function
5443 arguments and frame bases. Older versions of GDB could crash when they
5446 * C++ nested types and namespaces
5448 GDB's support for nested types and namespaces in C++ has been
5449 improved, especially if you use the DWARF 2 debugging format. (This
5450 is the default for recent versions of GCC on most platforms.)
5451 Specifically, if you have a class "Inner" defined within a class or
5452 namespace "Outer", then GDB realizes that the class's name is
5453 "Outer::Inner", not simply "Inner". This should greatly reduce the
5454 frequency of complaints about not finding RTTI symbols. In addition,
5455 if you are stopped at inside of a function defined within a namespace,
5456 GDB modifies its name lookup accordingly.
5458 * New native configurations
5460 NetBSD/amd64 x86_64-*-netbsd*
5461 OpenBSD/amd64 x86_64-*-openbsd*
5462 OpenBSD/alpha alpha*-*-openbsd*
5463 OpenBSD/sparc sparc-*-openbsd*
5464 OpenBSD/sparc64 sparc64-*-openbsd*
5466 * New debugging protocols
5468 M32R with SDI protocol m32r-*-elf*
5470 * "set prompt-escape-char" command deleted.
5472 The command "set prompt-escape-char" has been deleted. This command,
5473 and its very obscure effet on GDB's prompt, was never documented,
5474 tested, nor mentioned in the NEWS file.
5476 * OBSOLETE configurations and files
5478 Configurations that have been declared obsolete in this release have
5479 been commented out. Unless there is activity to revive these
5480 configurations, the next release of GDB will have their sources
5481 permanently REMOVED.
5483 Sun 3, running SunOS 3 m68*-*-sunos3*
5484 Sun 3, running SunOS 4 m68*-*-sunos4*
5485 Sun 2, running SunOS 3 m68000-*-sunos3*
5486 Sun 2, running SunOS 4 m68000-*-sunos4*
5487 Motorola 680x0 running LynxOS m68*-*-lynxos*
5488 AT&T 3b1/Unix pc m68*-att-*
5489 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5490 decstation mips-dec-* mips-little-*
5491 riscos mips-*-riscos* mips-*-sysv*
5492 sonymips mips-sony-*
5493 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5495 * REMOVED configurations and files
5497 SGI Irix-4.x mips-sgi-irix4 or iris4
5498 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5499 Z8000 simulator z8k-zilog-none or z8ksim
5500 Matsushita MN10200 w/simulator mn10200-*-*
5501 H8/500 simulator h8500-hitachi-hms or h8500hms
5502 HP/PA running BSD hppa*-*-bsd*
5503 HP/PA running OSF/1 hppa*-*-osf*
5504 HP/PA Pro target hppa*-*-pro*
5505 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5506 386BSD i[3456]86-*-bsd*
5507 Sequent family i[3456]86-sequent-sysv4*
5508 i[3456]86-sequent-sysv*
5509 i[3456]86-sequent-bsd*
5510 SPARC running LynxOS sparc-*-lynxos*
5511 SPARC running SunOS 4 sparc-*-sunos4*
5512 Tsqware Sparclet sparclet-*-*
5513 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5515 *** Changes in GDB 6.0:
5519 Support for debugging the Objective-C programming language has been
5520 integrated into GDB.
5522 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5524 DWARF 2's Call Frame Information makes available compiler generated
5525 information that more exactly describes the program's run-time stack.
5526 By using this information, GDB is able to provide more robust stack
5529 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5530 have been updated to use a new backtrace mechanism which includes
5531 DWARF 2 CFI support.
5535 GDB's remote protocol has been extended to include support for hosted
5536 file I/O (where the remote target uses GDB's file system). See GDB's
5537 remote protocol documentation for details.
5539 * All targets using the new architecture framework.
5541 All of GDB's targets have been updated to use the new internal
5542 architecture framework. The way is now open for future GDB releases
5543 to include cross-architecture native debugging support (i386 on amd64,
5546 * GNU/Linux's Thread Local Storage (TLS)
5548 GDB now includes support for for the GNU/Linux implementation of
5549 per-thread variables.
5551 * GNU/Linux's Native POSIX Thread Library (NPTL)
5553 GDB's thread code has been updated to work with either the new
5554 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5556 * Separate debug info.
5558 GDB, in conjunction with BINUTILS, now supports a mechanism for
5559 automatically loading debug information from a separate file. Instead
5560 of shipping full debug and non-debug versions of system libraries,
5561 system integrators can now instead ship just the stripped libraries
5562 and optional debug files.
5564 * DWARF 2 Location Expressions
5566 DWARF 2 Location Expressions allow the compiler to more completely
5567 describe the location of variables (even in optimized code) to the
5570 GDB now includes preliminary support for location expressions (support
5571 for DW_OP_piece is still missing).
5575 A number of long standing bugs that caused GDB to die while starting a
5576 Java application have been fixed. GDB's Java support is now
5577 considered "useable".
5579 * GNU/Linux support for fork, vfork, and exec.
5581 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5582 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5585 * GDB supports logging output to a file
5587 There are two new commands, "set logging" and "show logging", which can be
5588 used to capture GDB's output to a file.
5590 * The meaning of "detach" has changed for gdbserver
5592 The "detach" command will now resume the application, as documented. To
5593 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5596 * d10v, m68hc11 `regs' command deprecated
5598 The `info registers' command has been updated so that it displays the
5599 registers using a format identical to the old `regs' command.
5603 A new command, "maint set profile on/off", has been added. This command can
5604 be used to enable or disable profiling while running GDB, to profile a
5605 session or a set of commands. In addition there is a new configure switch,
5606 "--enable-profiling", which will cause GDB to be compiled with profiling
5607 data, for more informative profiling results.
5609 * Default MI syntax changed to "mi2".
5611 The default MI (machine interface) syntax, enabled by the command line
5612 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5613 "mi1", can be enabled by specifying the option "-i=mi1".
5615 Support for the original "mi0" syntax (included in GDB 5.0) has been
5618 Fix for gdb/192: removed extraneous space when displaying frame level.
5619 Fix for gdb/672: update changelist is now output in mi list format.
5620 Fix for gdb/702: a -var-assign that updates the value now shows up
5621 in a subsequent -var-update.
5623 * New native configurations.
5625 FreeBSD/amd64 x86_64-*-freebsd*
5627 * Multi-arched targets.
5629 HP/PA HPUX11 hppa*-*-hpux*
5630 Renesas M32R/D w/simulator m32r-*-elf*
5632 * OBSOLETE configurations and files
5634 Configurations that have been declared obsolete in this release have
5635 been commented out. Unless there is activity to revive these
5636 configurations, the next release of GDB will have their sources
5637 permanently REMOVED.
5639 Z8000 simulator z8k-zilog-none or z8ksim
5640 Matsushita MN10200 w/simulator mn10200-*-*
5641 H8/500 simulator h8500-hitachi-hms or h8500hms
5642 HP/PA running BSD hppa*-*-bsd*
5643 HP/PA running OSF/1 hppa*-*-osf*
5644 HP/PA Pro target hppa*-*-pro*
5645 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5646 Sequent family i[3456]86-sequent-sysv4*
5647 i[3456]86-sequent-sysv*
5648 i[3456]86-sequent-bsd*
5649 Tsqware Sparclet sparclet-*-*
5650 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5652 * REMOVED configurations and files
5655 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5656 IBM AIX PS/2 i[3456]86-*-aix
5657 i386 running Mach 3.0 i[3456]86-*-mach3*
5658 i386 running Mach i[3456]86-*-mach*
5659 i386 running OSF/1 i[3456]86-*osf1mk*
5660 HP/Apollo 68k Family m68*-apollo*-sysv*,
5662 m68*-hp-bsd*, m68*-hp-hpux*
5663 Argonaut Risc Chip (ARC) arc-*-*
5664 Mitsubishi D30V d30v-*-*
5665 Fujitsu FR30 fr30-*-elf*
5666 OS/9000 i[34]86-*-os9k
5667 I960 with MON960 i960-*-coff
5669 * MIPS $fp behavior changed
5671 The convenience variable $fp, for the MIPS, now consistently returns
5672 the address of the current frame's base. Previously, depending on the
5673 context, $fp could refer to either $sp or the current frame's base
5674 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5675 The GNU Source-Level Debugger''.
5677 *** Changes in GDB 5.3:
5679 * GNU/Linux shared library multi-threaded performance improved.
5681 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5682 `/proc', in preference to `ptrace' for memory reads. This may result
5683 in an improvement in the start-up time of multi-threaded, shared
5684 library applications when run under GDB. One GDB user writes: ``loads
5685 shared libs like mad''.
5687 * ``gdbserver'' now supports multi-threaded applications on some targets
5689 Support for debugging multi-threaded applications which use
5690 the GNU/Linux LinuxThreads package has been added for
5691 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5692 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5694 * GDB now supports C/C++ preprocessor macros.
5696 GDB now expands preprocessor macro invocations in C/C++ expressions,
5697 and provides various commands for showing macro definitions and how
5700 The new command `macro expand EXPRESSION' expands any macro
5701 invocations in expression, and shows the result.
5703 The new command `show macro MACRO-NAME' shows the definition of the
5704 macro named MACRO-NAME, and where it was defined.
5706 Most compilers don't include information about macros in the debugging
5707 information by default. In GCC 3.1, for example, you need to compile
5708 your program with the options `-gdwarf-2 -g3'. If the macro
5709 information is present in the executable, GDB will read it.
5711 * Multi-arched targets.
5713 DEC Alpha (partial) alpha*-*-*
5714 DEC VAX (partial) vax-*-*
5716 National Semiconductor NS32000 (partial) ns32k-*-*
5717 Motorola 68000 (partial) m68k-*-*
5718 Motorola MCORE mcore-*-*
5722 Fujitsu FRV architecture added by Red Hat frv*-*-*
5725 * New native configurations
5727 Alpha NetBSD alpha*-*-netbsd*
5728 SH NetBSD sh*-*-netbsdelf*
5729 MIPS NetBSD mips*-*-netbsd*
5730 UltraSPARC NetBSD sparc64-*-netbsd*
5732 * OBSOLETE configurations and files
5734 Configurations that have been declared obsolete in this release have
5735 been commented out. Unless there is activity to revive these
5736 configurations, the next release of GDB will have their sources
5737 permanently REMOVED.
5739 Mitsubishi D30V d30v-*-*
5740 OS/9000 i[34]86-*-os9k
5741 IBM AIX PS/2 i[3456]86-*-aix
5742 Fujitsu FR30 fr30-*-elf*
5743 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5744 Argonaut Risc Chip (ARC) arc-*-*
5745 i386 running Mach 3.0 i[3456]86-*-mach3*
5746 i386 running Mach i[3456]86-*-mach*
5747 i386 running OSF/1 i[3456]86-*osf1mk*
5748 HP/Apollo 68k Family m68*-apollo*-sysv*,
5750 m68*-hp-bsd*, m68*-hp-hpux*
5751 I960 with MON960 i960-*-coff
5753 * OBSOLETE languages
5755 CHILL, a Pascal like language used by telecommunications companies.
5757 * REMOVED configurations and files
5759 AMD 29k family via UDI a29k-amd-udi, udi29k
5760 A29K VxWorks a29k-*-vxworks
5761 AMD 29000 embedded, using EBMON a29k-none-none
5762 AMD 29000 embedded with COFF a29k-none-coff
5763 AMD 29000 embedded with a.out a29k-none-aout
5765 testsuite/gdb.hp/gdb.threads-hp/ directory
5767 * New command "set max-user-call-depth <nnn>"
5769 This command allows the user to limit the call depth of user-defined
5770 commands. The default is 1024.
5772 * Changes in FreeBSD/i386 native debugging.
5774 Support for the "generate-core-file" has been added.
5776 * New commands "dump", "append", and "restore".
5778 These commands allow data to be copied from target memory
5779 to a bfd-format or binary file (dump and append), and back
5780 from a file into memory (restore).
5782 * Improved "next/step" support on multi-processor Alpha Tru64.
5784 The previous single-step mechanism could cause unpredictable problems,
5785 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5786 of a software single-step mechanism prevents this.
5788 *** Changes in GDB 5.2.1:
5796 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5797 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5798 Fix, by Joel Brobecker imported from mainline.
5800 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5801 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5802 Fix, by Fred Fish, imported from mainline.
5804 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5805 Surprisingly enough, it works now.
5806 By Michal Ludvig, imported from mainline.
5808 i386 hardware watchpoint support:
5809 avoid misses on second run for some targets.
5810 By Pierre Muller, imported from mainline.
5812 *** Changes in GDB 5.2:
5814 * New command "set trust-readonly-sections on[off]".
5816 This command is a hint that tells gdb that read-only sections
5817 really are read-only (ie. that their contents will not change).
5818 In this mode, gdb will go to the object file rather than the
5819 target to read memory from read-only sections (such as ".text").
5820 This can be a significant performance improvement on some
5821 (notably embedded) targets.
5823 * New command "generate-core-file" (or "gcore").
5825 This new gdb command allows the user to drop a core file of the child
5826 process state at any time. So far it's been implemented only for
5827 GNU/Linux and Solaris, but should be relatively easily ported to other
5828 hosts. Argument is core file name (defaults to core.<pid>).
5830 * New command line option
5832 GDB now accepts --pid or -p followed by a process id.
5834 * Change in command line behavior -- corefiles vs. process ids.
5836 There is a subtle behavior in the way in which GDB handles
5837 command line arguments. The first non-flag argument is always
5838 a program to debug, but the second non-flag argument may either
5839 be a corefile or a process id. Previously, GDB would attempt to
5840 open the second argument as a corefile, and if that failed, would
5841 issue a superfluous error message and then attempt to attach it as
5842 a process. Now, if the second argument begins with a non-digit,
5843 it will be treated as a corefile. If it begins with a digit,
5844 GDB will attempt to attach it as a process, and if no such process
5845 is found, will then attempt to open it as a corefile.
5847 * Changes in ARM configurations.
5849 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5850 configuration is fully multi-arch.
5852 * New native configurations
5854 ARM NetBSD arm*-*-netbsd*
5855 x86 OpenBSD i[3456]86-*-openbsd*
5856 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5857 Sparc64 running FreeBSD sparc64-*-freebsd*
5861 Sanyo XStormy16 xstormy16-elf
5863 * OBSOLETE configurations and files
5865 Configurations that have been declared obsolete in this release have
5866 been commented out. Unless there is activity to revive these
5867 configurations, the next release of GDB will have their sources
5868 permanently REMOVED.
5870 AMD 29k family via UDI a29k-amd-udi, udi29k
5871 A29K VxWorks a29k-*-vxworks
5872 AMD 29000 embedded, using EBMON a29k-none-none
5873 AMD 29000 embedded with COFF a29k-none-coff
5874 AMD 29000 embedded with a.out a29k-none-aout
5876 testsuite/gdb.hp/gdb.threads-hp/ directory
5878 * REMOVED configurations and files
5880 TI TMS320C80 tic80-*-*
5882 PowerPC Solaris powerpcle-*-solaris*
5883 PowerPC Windows NT powerpcle-*-cygwin32
5884 PowerPC Netware powerpc-*-netware*
5885 Harris/CXUX m88k m88*-harris-cxux*
5886 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5887 ns32k-utek-sysv* ns32k-utek-*
5888 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5889 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5890 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5891 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5892 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5894 * Changes to command line processing
5896 The new `--args' feature can be used to specify command-line arguments
5897 for the inferior from gdb's command line.
5899 * Changes to key bindings
5901 There is a new `operate-and-get-next' function bound to `C-o'.
5903 *** Changes in GDB 5.1.1
5905 Fix compile problem on DJGPP.
5907 Fix a problem with floating-point registers on the i386 being
5910 Fix to stop GDB crashing on .debug_str debug info.
5912 Numerous documentation fixes.
5914 Numerous testsuite fixes.
5916 *** Changes in GDB 5.1:
5918 * New native configurations
5920 Alpha FreeBSD alpha*-*-freebsd*
5921 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5922 MIPS GNU/Linux mips*-*-linux*
5923 MIPS SGI Irix 6.x mips*-sgi-irix6*
5924 ia64 AIX ia64-*-aix*
5925 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5929 Motorola 68HC11 and 68HC12 m68hc11-elf
5931 UltraSparc running GNU/Linux sparc64-*-linux*
5933 * OBSOLETE configurations and files
5935 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5936 Harris/CXUX m88k m88*-harris-cxux*
5937 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5938 ns32k-utek-sysv* ns32k-utek-*
5939 TI TMS320C80 tic80-*-*
5941 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5942 PowerPC Solaris powerpcle-*-solaris*
5943 PowerPC Windows NT powerpcle-*-cygwin32
5944 PowerPC Netware powerpc-*-netware*
5945 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5946 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5947 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5948 Apple Macintosh (MPW) host N/A
5950 stuff.c (Program to stuff files into a specially prepared space in kdb)
5951 kdb-start.c (Main loop for the standalone kernel debugger)
5953 Configurations that have been declared obsolete in this release have
5954 been commented out. Unless there is activity to revive these
5955 configurations, the next release of GDB will have their sources
5956 permanently REMOVED.
5958 * REMOVED configurations and files
5960 Altos 3068 m68*-altos-*
5961 Convex c1-*-*, c2-*-*
5963 ARM RISCix arm-*-* (as host)
5967 * GDB has been converted to ISO C.
5969 GDB's source code has been converted to ISO C. In particular, the
5970 sources are fully protoized, and rely on standard headers being
5975 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5977 * The MI enabled by default.
5979 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5980 revised and enabled by default. Packages which use GDB as a debugging
5981 engine behind a UI or another front end are encouraged to switch to
5982 using the GDB/MI interface, instead of the old annotations interface
5983 which is now deprecated.
5985 * Support for debugging Pascal programs.
5987 GDB now includes support for debugging Pascal programs. The following
5988 main features are supported:
5990 - Pascal-specific data types such as sets;
5992 - automatic recognition of Pascal sources based on file-name
5995 - Pascal-style display of data types, variables, and functions;
5997 - a Pascal expression parser.
5999 However, some important features are not yet supported.
6001 - Pascal string operations are not supported at all;
6003 - there are some problems with boolean types;
6005 - Pascal type hexadecimal constants are not supported
6006 because they conflict with the internal variables format;
6008 - support for Pascal objects and classes is not full yet;
6010 - unlike Pascal, GDB is case-sensitive for symbol names.
6012 * Changes in completion.
6014 Commands such as `shell', `run' and `set args', which pass arguments
6015 to inferior programs, now complete on file names, similar to what
6016 users expect at the shell prompt.
6018 Commands which accept locations, such as `disassemble', `print',
6019 `breakpoint', `until', etc. now complete on filenames as well as
6020 program symbols. Thus, if you type "break foob TAB", and the source
6021 files linked into the programs include `foobar.c', that file name will
6022 be one of the candidates for completion. However, file names are not
6023 considered for completion after you typed a colon that delimits a file
6024 name from a name of a function in that file, as in "break foo.c:bar".
6026 `set demangle-style' completes on available demangling styles.
6028 * New platform-independent commands:
6030 It is now possible to define a post-hook for a command as well as a
6031 hook that runs before the command. For more details, see the
6032 documentation of `hookpost' in the GDB manual.
6034 * Changes in GNU/Linux native debugging.
6036 Support for debugging multi-threaded programs has been completely
6037 revised for all platforms except m68k and sparc. You can now debug as
6038 many threads as your system allows you to have.
6040 Attach/detach is supported for multi-threaded programs.
6042 Support for SSE registers was added for x86. This doesn't work for
6043 multi-threaded programs though.
6045 * Changes in MIPS configurations.
6047 Multi-arch support is enabled for all MIPS configurations.
6049 GDB can now be built as native debugger on SGI Irix 6.x systems for
6050 debugging n32 executables. (Debugging 64-bit executables is not yet
6053 * Unified support for hardware watchpoints in all x86 configurations.
6055 Most (if not all) native x86 configurations support hardware-assisted
6056 breakpoints and watchpoints in a unified manner. This support
6057 implements debug register sharing between watchpoints, which allows to
6058 put a virtually infinite number of watchpoints on the same address,
6059 and also supports watching regions up to 16 bytes with several debug
6062 The new maintenance command `maintenance show-debug-regs' toggles
6063 debugging print-outs in functions that insert, remove, and test
6064 watchpoints and hardware breakpoints.
6066 * Changes in the DJGPP native configuration.
6068 New command ``info dos sysinfo'' displays assorted information about
6069 the CPU, OS, memory, and DPMI server.
6071 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6072 display information about segment descriptors stored in GDT, LDT, and
6075 New commands ``info dos pde'' and ``info dos pte'' display entries
6076 from Page Directory and Page Tables (for now works with CWSDPMI only).
6077 New command ``info dos address-pte'' displays the Page Table entry for
6078 a given linear address.
6080 GDB can now pass command lines longer than 126 characters to the
6081 program being debugged (requires an update to the libdbg.a library
6082 which is part of the DJGPP development kit).
6084 DWARF2 debug info is now supported.
6086 It is now possible to `step' and `next' through calls to `longjmp'.
6088 * Changes in documentation.
6090 All GDB documentation was converted to GFDL, the GNU Free
6091 Documentation License.
6093 Tracepoints-related commands are now fully documented in the GDB
6096 TUI, the Text-mode User Interface, is now documented in the manual.
6098 Tracepoints-related commands are now fully documented in the GDB
6101 The "GDB Internals" manual now has an index. It also includes
6102 documentation of `ui_out' functions, GDB coding standards, x86
6103 hardware watchpoints, and memory region attributes.
6105 * GDB's version number moved to ``version.in''
6107 The Makefile variable VERSION has been replaced by the file
6108 ``version.in''. People creating GDB distributions should update the
6109 contents of this file.
6113 GUD support is now a standard part of the EMACS distribution.
6115 *** Changes in GDB 5.0:
6117 * Improved support for debugging FP programs on x86 targets
6119 Unified and much-improved support for debugging floating-point
6120 programs on all x86 targets. In particular, ``info float'' now
6121 displays the FP registers in the same format on all x86 targets, with
6122 greater level of detail.
6124 * Improvements and bugfixes in hardware-assisted watchpoints
6126 It is now possible to watch array elements, struct members, and
6127 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6128 on x86 targets no longer erroneously trigger when the address is
6131 * Improvements in the native DJGPP version of GDB
6133 The distribution now includes all the scripts and auxiliary files
6134 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6135 machines ``out of the box''.
6137 The DJGPP version can now debug programs that use signals. It is
6138 possible to catch signals that happened in the debuggee, deliver
6139 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6140 would kill the program being debugged.) Programs that hook hardware
6141 interrupts (keyboard, timer, etc.) can also be debugged.
6143 It is now possible to debug DJGPP programs that redirect their
6144 standard handles or switch them to raw (as opposed to cooked) mode, or
6145 even close them. The command ``run < foo > bar'' works as expected,
6146 and ``info terminal'' reports useful information about the debuggee's
6147 terminal, including raw/cooked mode, redirection, etc.
6149 The DJGPP version now uses termios functions for console I/O, which
6150 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6153 DOS-style file names with drive letters are now fully supported by
6156 It is now possible to debug DJGPP programs that switch their working
6157 directory. It is also possible to rerun the debuggee any number of
6158 times without restarting GDB; thus, you can use the same setup,
6159 breakpoints, etc. for many debugging sessions.
6161 * New native configurations
6163 ARM GNU/Linux arm*-*-linux*
6164 PowerPC GNU/Linux powerpc-*-linux*
6168 Motorola MCore mcore-*-*
6169 x86 VxWorks i[3456]86-*-vxworks*
6170 PowerPC VxWorks powerpc-*-vxworks*
6171 TI TMS320C80 tic80-*-*
6173 * OBSOLETE configurations
6175 Altos 3068 m68*-altos-*
6176 Convex c1-*-*, c2-*-*
6178 ARM RISCix arm-*-* (as host)
6181 Configurations that have been declared obsolete will be commented out,
6182 but the code will be left in place. If there is no activity to revive
6183 these configurations before the next release of GDB, the sources will
6184 be permanently REMOVED.
6186 * Gould support removed
6188 Support for the Gould PowerNode and NP1 has been removed.
6190 * New features for SVR4
6192 On SVR4 native platforms (such as Solaris), if you attach to a process
6193 without first loading a symbol file, GDB will now attempt to locate and
6194 load symbols from the running process's executable file.
6196 * Many C++ enhancements
6198 C++ support has been greatly improved. Overload resolution now works properly
6199 in almost all cases. RTTI support is on the way.
6201 * Remote targets can connect to a sub-program
6203 A popen(3) style serial-device has been added. This device starts a
6204 sub-process (such as a stand-alone simulator) and then communicates
6205 with that. The sub-program to run is specified using the syntax
6206 ``|<program> <args>'' vis:
6208 (gdb) set remotedebug 1
6209 (gdb) target extended-remote |mn10300-elf-sim program-args
6211 * MIPS 64 remote protocol
6213 A long standing bug in the mips64 remote protocol where by GDB
6214 expected certain 32 bit registers (ex SR) to be transfered as 32
6215 instead of 64 bits has been fixed.
6217 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6218 added to provide backward compatibility with older versions of GDB.
6220 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6222 The command ``set remotebinarydownload'' command has been replaced by
6223 ``set remote X-packet''. Other commands in ``set remote'' family
6224 include ``set remote P-packet''.
6226 * Breakpoint commands accept ranges.
6228 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6229 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6230 ``tracepoint passcount'' also accepts a range of tracepoints.
6232 * ``apropos'' command added.
6234 The ``apropos'' command searches through command names and
6235 documentation strings, printing out matches, making it much easier to
6236 try to find a command that does what you are looking for.
6240 A new machine oriented interface (MI) has been added to GDB. This
6241 interface is designed for debug environments running GDB as a separate
6242 process. This is part of the long term libGDB project. See the
6243 "GDB/MI" chapter of the GDB manual for further information. It can be
6244 enabled by configuring with:
6246 .../configure --enable-gdbmi
6248 *** Changes in GDB-4.18:
6250 * New native configurations
6252 HP-UX 10.20 hppa*-*-hpux10.20
6253 HP-UX 11.x hppa*-*-hpux11.0*
6254 M68K GNU/Linux m68*-*-linux*
6258 Fujitsu FR30 fr30-*-elf*
6259 Intel StrongARM strongarm-*-*
6260 Mitsubishi D30V d30v-*-*
6262 * OBSOLETE configurations
6264 Gould PowerNode, NP1 np1-*-*, pn-*-*
6266 Configurations that have been declared obsolete will be commented out,
6267 but the code will be left in place. If there is no activity to revive
6268 these configurations before the next release of GDB, the sources will
6269 be permanently REMOVED.
6273 As a compatibility experiment, GDB's source files buildsym.h and
6274 buildsym.c have been converted to pure standard C, no longer
6275 containing any K&R compatibility code. We believe that all systems in
6276 use today either come with a standard C compiler, or have a GCC port
6277 available. If this is not true, please report the affected
6278 configuration to bug-gdb@gnu.org immediately. See the README file for
6279 information about getting a standard C compiler if you don't have one
6284 GDB now uses readline 2.2.
6286 * set extension-language
6288 You can now control the mapping between filename extensions and source
6289 languages by using the `set extension-language' command. For instance,
6290 you can ask GDB to treat .c files as C++ by saying
6291 set extension-language .c c++
6292 The command `info extensions' lists all of the recognized extensions
6293 and their associated languages.
6295 * Setting processor type for PowerPC and RS/6000
6297 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6298 you can use the `set processor' command to specify what variant of the
6299 PowerPC family you are debugging. The command
6303 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6304 following PowerPC and RS6000 variants:
6306 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6307 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6309 403GC IBM PowerPC 403GC
6310 505 Motorola PowerPC 505
6311 860 Motorola PowerPC 860 or 850
6312 601 Motorola PowerPC 601
6313 602 Motorola PowerPC 602
6314 603 Motorola/IBM PowerPC 603 or 603e
6315 604 Motorola PowerPC 604 or 604e
6316 750 Motorola/IBM PowerPC 750 or 750
6318 At the moment, this command just tells GDB what to name the
6319 special-purpose processor registers. Since almost all the affected
6320 registers are inaccessible to user-level programs, this command is
6321 only useful for remote debugging in its present form.
6325 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6326 more extensive support for HP-UX. Added features include shared
6327 library support, kernel threads and hardware watchpoints for 11.00,
6328 support for HP's ANSI C and C++ compilers, and a compatibility mode
6329 for xdb and dbx commands.
6333 HP's donation includes the new concept of catchpoints, which is a
6334 generalization of the old catch command. On HP-UX, it is now possible
6335 to catch exec, fork, and vfork, as well as library loading.
6337 This means that the existing catch command has changed; its first
6338 argument now specifies the type of catch to be set up. See the
6339 output of "help catch" for a list of catchpoint types.
6341 * Debugging across forks
6343 On HP-UX, you can choose which process to debug when a fork() happens
6348 HP has donated a curses-based terminal user interface (TUI). To get
6349 it, build with --enable-tui. Although this can be enabled for any
6350 configuration, at present it only works for native HP debugging.
6352 * GDB remote protocol additions
6354 A new protocol packet 'X' that writes binary data is now available.
6355 Default behavior is to try 'X', then drop back to 'M' if the stub
6356 fails to respond. The settable variable `remotebinarydownload'
6357 allows explicit control over the use of 'X'.
6359 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6360 full 64-bit address. The command
6362 set remoteaddresssize 32
6364 can be used to revert to the old behaviour. For existing remote stubs
6365 the change should not be noticed, as the additional address information
6368 In order to assist in debugging stubs, you may use the maintenance
6369 command `packet' to send any text string to the stub. For instance,
6371 maint packet heythere
6373 sends the packet "$heythere#<checksum>". Note that it is very easy to
6374 disrupt a debugging session by sending the wrong packet at the wrong
6377 The compare-sections command allows you to compare section data on the
6378 target to what is in the executable file without uploading or
6379 downloading, by comparing CRC checksums.
6381 * Tracing can collect general expressions
6383 You may now collect general expressions at tracepoints. This requires
6384 further additions to the target-side stub; see tracepoint.c and
6385 doc/agentexpr.texi for further details.
6387 * mask-address variable for Mips
6389 For Mips targets, you may control the zeroing of the upper 32 bits of
6390 a 64-bit address by entering `set mask-address on'. This is mainly
6391 of interest to users of embedded R4xxx and R5xxx processors.
6393 * Higher serial baud rates
6395 GDB's serial code now allows you to specify baud rates 57600, 115200,
6396 230400, and 460800 baud. (Note that your host system may not be able
6397 to achieve all of these rates.)
6401 The i960 configuration now includes an initial implementation of a
6402 builtin simulator, contributed by Jim Wilson.
6405 *** Changes in GDB-4.17:
6407 * New native configurations
6409 Alpha GNU/Linux alpha*-*-linux*
6410 Unixware 2.x i[3456]86-unixware2*
6411 Irix 6.x mips*-sgi-irix6*
6412 PowerPC GNU/Linux powerpc-*-linux*
6413 PowerPC Solaris powerpcle-*-solaris*
6414 Sparc GNU/Linux sparc-*-linux*
6415 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6419 Argonaut Risc Chip (ARC) arc-*-*
6420 Hitachi H8/300S h8300*-*-*
6421 Matsushita MN10200 w/simulator mn10200-*-*
6422 Matsushita MN10300 w/simulator mn10300-*-*
6423 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6424 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6425 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6426 Mitsubishi D10V w/simulator d10v-*-*
6427 Mitsubishi M32R/D w/simulator m32r-*-elf*
6428 Tsqware Sparclet sparclet-*-*
6429 NEC V850 w/simulator v850-*-*
6431 * New debugging protocols
6433 ARM with RDI protocol arm*-*-*
6434 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6435 DDB and LSI variants of PMON protocol mips*-*-*
6436 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6437 PowerPC with SDS protocol powerpc{,le}-*-eabi
6438 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6442 All configurations can now understand and use the DWARF 2 debugging
6443 format. The choice is automatic, if the symbol file contains DWARF 2
6448 GDB now includes basic Java language support. This support is
6449 only useful with Java compilers that produce native machine code.
6451 * solib-absolute-prefix and solib-search-path
6453 For SunOS and SVR4 shared libraries, you may now set the prefix for
6454 loading absolute shared library symbol files, and the search path for
6455 locating non-absolute shared library symbol files.
6457 * Live range splitting
6459 GDB can now effectively debug code for which GCC has performed live
6460 range splitting as part of its optimization. See gdb/doc/LRS for
6461 more details on the expected format of the stabs information.
6465 GDB's support for the GNU Hurd, including thread debugging, has been
6466 updated to work with current versions of the Hurd.
6470 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6471 instruction set. ARM GDB automatically detects when Thumb
6472 instructions are in use, and adjusts disassembly and backtracing
6477 GDB's MIPS target configurations now handle the MIP16 16-bit
6482 GDB now includes support for overlays; if an executable has been
6483 linked such that multiple sections are based at the same address, GDB
6484 will decide which section to use for symbolic info. You can choose to
6485 control the decision manually, using overlay commands, or implement
6486 additional target-side support and use "overlay load-target" to bring
6487 in the overlay mapping. Do "help overlay" for more detail.
6491 The command "info symbol <address>" displays information about
6492 the symbol at the specified address.
6496 The standard remote protocol now includes an extension that allows
6497 asynchronous collection and display of trace data. This requires
6498 extensive support in the target-side debugging stub. Tracing mode
6499 includes a new interaction mode in GDB and new commands: see the
6500 file tracepoint.c for more details.
6504 Configurations for embedded MIPS now include a simulator contributed
6505 by Cygnus Solutions. The simulator supports the instruction sets
6506 of most MIPS variants.
6510 Sparc configurations may now include the ERC32 simulator contributed
6511 by the European Space Agency. The simulator is not built into
6512 Sparc targets by default; configure with --enable-sim to include it.
6516 For target configurations that may include multiple variants of a
6517 basic architecture (such as MIPS and SH), you may now set the
6518 architecture explicitly. "set arch" sets, "info arch" lists
6519 the possible architectures.
6521 *** Changes in GDB-4.16:
6523 * New native configurations
6525 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6526 M68K NetBSD m68k-*-netbsd*
6527 PowerPC AIX 4.x powerpc-*-aix*
6528 PowerPC MacOS powerpc-*-macos*
6529 PowerPC Windows NT powerpcle-*-cygwin32
6530 RS/6000 AIX 4.x rs6000-*-aix4*
6534 ARM with RDP protocol arm-*-*
6535 I960 with MON960 i960-*-coff
6536 MIPS VxWorks mips*-*-vxworks*
6537 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6538 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6540 Matra Sparclet sparclet-*-*
6544 The powerpc-eabi configuration now includes the PSIM simulator,
6545 contributed by Andrew Cagney, with assistance from Mike Meissner.
6546 PSIM is a very elaborate model of the PowerPC, including not only
6547 basic instruction set execution, but also details of execution unit
6548 performance and I/O hardware. See sim/ppc/README for more details.
6552 GDB now works with Solaris 2.5.
6554 * Windows 95/NT native
6556 GDB will now work as a native debugger on Windows 95 and Windows NT.
6557 To build it from source, you must use the "gnu-win32" environment,
6558 which uses a DLL to emulate enough of Unix to run the GNU tools.
6559 Further information, binaries, and sources are available at
6560 ftp.cygnus.com, under pub/gnu-win32.
6562 * dont-repeat command
6564 If a user-defined command includes the command `dont-repeat', then the
6565 command will not be repeated if the user just types return. This is
6566 useful if the command is time-consuming to run, so that accidental
6567 extra keystrokes don't run the same command many times.
6569 * Send break instead of ^C
6571 The standard remote protocol now includes an option to send a break
6572 rather than a ^C to the target in order to interrupt it. By default,
6573 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6575 * Remote protocol timeout
6577 The standard remote protocol includes a new variable `remotetimeout'
6578 that allows you to set the number of seconds before GDB gives up trying
6579 to read from the target. The default value is 2.
6581 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6583 By default GDB will automatically keep track of objects as they are
6584 loaded and unloaded by the dynamic linker. By using the command `set
6585 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6586 when shared library events occur, thus allowing you to set breakpoints
6587 in shared libraries which are explicitly loaded by the inferior.
6589 Note this feature does not work on hpux8. On hpux9 you must link
6590 /usr/lib/end.o into your program. This feature should work
6591 automatically on hpux10.
6593 * Irix 5.x hardware watchpoint support
6595 Irix 5 configurations now support the use of hardware watchpoints.
6597 * Mips protocol "SYN garbage limit"
6599 When debugging a Mips target using the `target mips' protocol, you
6600 may set the number of characters that GDB will ignore by setting
6601 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6602 every character. The default value is 1050.
6604 * Recording and replaying remote debug sessions
6606 If you set `remotelogfile' to the name of a file, gdb will write to it
6607 a recording of a remote debug session. This recording may then be
6608 replayed back to gdb using "gdbreplay". See gdbserver/README for
6609 details. This is useful when you have a problem with GDB while doing
6610 remote debugging; you can make a recording of the session and send it
6611 to someone else, who can then recreate the problem.
6613 * Speedups for remote debugging
6615 GDB includes speedups for downloading and stepping MIPS systems using
6616 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6617 and more efficient S-record downloading.
6619 * Memory use reductions and statistics collection
6621 GDB now uses less memory and reports statistics about memory usage.
6622 Try the `maint print statistics' command, for example.
6624 *** Changes in GDB-4.15:
6626 * Psymtabs for XCOFF
6628 The symbol reader for AIX GDB now uses partial symbol tables. This
6629 can greatly improve startup time, especially for large executables.
6631 * Remote targets use caching
6633 Remote targets now use a data cache to speed up communication with the
6634 remote side. The data cache could lead to incorrect results because
6635 it doesn't know about volatile variables, thus making it impossible to
6636 debug targets which use memory mapped I/O devices. `set remotecache
6637 off' turns the data cache off.
6639 * Remote targets may have threads
6641 The standard remote protocol now includes support for multiple threads
6642 in the target system, using new protocol commands 'H' and 'T'. See
6643 gdb/remote.c for details.
6647 If GDB is configured with `--enable-netrom', then it will include
6648 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6649 acts as though it is a bank of ROM on the target board, but you can
6650 write into it over the network. GDB's support consists only of
6651 support for fast loading into the emulated ROM; to debug, you must use
6652 another protocol, such as standard remote protocol. The usual
6653 sequence is something like
6655 target nrom <netrom-hostname>
6657 target remote <netrom-hostname>:1235
6661 GDB now includes support for the Apple Macintosh, as a host only. It
6662 may be run as either an MPW tool or as a standalone application, and
6663 it can debug through the serial port. All the usual GDB commands are
6664 available, but to the target command, you must supply "serial" as the
6665 device type instead of "/dev/ttyXX". See mpw-README in the main
6666 directory for more information on how to build. The MPW configuration
6667 scripts */mpw-config.in support only a few targets, and only the
6668 mips-idt-ecoff target has been tested.
6672 GDB configuration now uses autoconf. This is not user-visible,
6673 but does simplify configuration and building.
6677 GDB now supports hpux10.
6679 *** Changes in GDB-4.14:
6681 * New native configurations
6683 x86 FreeBSD i[345]86-*-freebsd
6684 x86 NetBSD i[345]86-*-netbsd
6685 NS32k NetBSD ns32k-*-netbsd
6686 Sparc NetBSD sparc-*-netbsd
6690 A29K VxWorks a29k-*-vxworks
6691 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6692 CPU32 EST-300 emulator m68*-*-est*
6693 PowerPC ELF powerpc-*-elf
6696 * Alpha OSF/1 support for procfs
6698 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6699 possible to attach to running processes. As the mounting of the /proc
6700 filesystem is optional on the Alpha, GDB automatically determines
6701 the availability of /proc during startup. This can lead to problems
6702 if /proc is unmounted after GDB has been started.
6704 * Arguments to user-defined commands
6706 User commands may accept up to 10 arguments separated by whitespace.
6707 Arguments are accessed within the user command via $arg0..$arg9. A
6710 print $arg0 + $arg1 + $arg2
6712 To execute the command use:
6715 Defines the command "adder" which prints the sum of its three arguments.
6716 Note the arguments are text substitutions, so they may reference variables,
6717 use complex expressions, or even perform inferior function calls.
6719 * New `if' and `while' commands
6721 This makes it possible to write more sophisticated user-defined
6722 commands. Both commands take a single argument, which is the
6723 expression to evaluate, and must be followed by the commands to
6724 execute, one per line, if the expression is nonzero, the list being
6725 terminated by the word `end'. The `if' command list may include an
6726 `else' word, which causes the following commands to be executed only
6727 if the expression is zero.
6729 * Fortran source language mode
6731 GDB now includes partial support for Fortran 77. It will recognize
6732 Fortran programs and can evaluate a subset of Fortran expressions, but
6733 variables and functions may not be handled correctly. GDB will work
6734 with G77, but does not yet know much about symbols emitted by other
6737 * Better HPUX support
6739 Most debugging facilities now work on dynamic executables for HPPAs
6740 running hpux9 or later. You can attach to running dynamically linked
6741 processes, but by default the dynamic libraries will be read-only, so
6742 for instance you won't be able to put breakpoints in them. To change
6743 that behavior do the following before running the program:
6749 This will cause the libraries to be mapped private and read-write.
6750 To revert to the normal behavior, do this:
6756 You cannot set breakpoints or examine data in the library until after
6757 the library is loaded if the function/data symbols do not have
6760 GDB can now also read debug symbols produced by the HP C compiler on
6761 HPPAs (sorry, no C++, Fortran or 68k support).
6763 * Target byte order now dynamically selectable
6765 You can choose which byte order to use with a target system, via the
6766 commands "set endian big" and "set endian little", and you can see the
6767 current setting by using "show endian". You can also give the command
6768 "set endian auto", in which case GDB will use the byte order
6769 associated with the executable. Currently, only embedded MIPS
6770 configurations support dynamic selection of target byte order.
6772 * New DOS host serial code
6774 This version uses DPMI interrupts to handle buffered I/O, so you
6775 no longer need to run asynctsr when debugging boards connected to
6778 *** Changes in GDB-4.13:
6780 * New "complete" command
6782 This lists all the possible completions for the rest of the line, if it
6783 were to be given as a command itself. This is intended for use by emacs.
6785 * Trailing space optional in prompt
6787 "set prompt" no longer adds a space for you after the prompt you set. This
6788 allows you to set a prompt which ends in a space or one that does not.
6790 * Breakpoint hit counts
6792 "info break" now displays a count of the number of times the breakpoint
6793 has been hit. This is especially useful in conjunction with "ignore"; you
6794 can ignore a large number of breakpoint hits, look at the breakpoint info
6795 to see how many times the breakpoint was hit, then run again, ignoring one
6796 less than that number, and this will get you quickly to the last hit of
6799 * Ability to stop printing at NULL character
6801 "set print null-stop" will cause GDB to stop printing the characters of
6802 an array when the first NULL is encountered. This is useful when large
6803 arrays actually contain only short strings.
6805 * Shared library breakpoints
6807 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6808 breakpoints in shared libraries before the executable is run.
6810 * Hardware watchpoints
6812 There is a new hardware breakpoint for the watch command for sparclite
6813 targets. See gdb/sparclite/hw_breakpoint.note.
6815 Hardware watchpoints are also now supported under GNU/Linux.
6819 Annotations have been added. These are for use with graphical interfaces,
6820 and are still experimental. Currently only gdba.el uses these.
6822 * Improved Irix 5 support
6824 GDB now works properly with Irix 5.2.
6826 * Improved HPPA support
6828 GDB now works properly with the latest GCC and GAS.
6830 * New native configurations
6832 Sequent PTX4 i[34]86-sequent-ptx4
6833 HPPA running OSF/1 hppa*-*-osf*
6834 Atari TT running SVR4 m68*-*-sysv4*
6835 RS/6000 LynxOS rs6000-*-lynxos*
6839 OS/9000 i[34]86-*-os9k
6840 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6843 * Hitachi SH7000 and E7000-PC ICE support
6845 There is now support for communicating with the Hitachi E7000-PC ICE.
6846 This is available automatically when GDB is configured for the SH.
6850 As usual, a variety of small fixes and improvements, both generic
6851 and configuration-specific. See the ChangeLog for more detail.
6853 *** Changes in GDB-4.12:
6855 * Irix 5 is now supported
6859 GDB-4.12 on the HPPA has a number of changes which make it unable
6860 to debug the output from the currently released versions of GCC and
6861 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6862 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6863 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6866 *** Changes in GDB-4.11:
6868 * User visible changes:
6872 The "set remotedebug" option is now consistent between the mips remote
6873 target, remote targets using the gdb-specific protocol, UDI (AMD's
6874 debug protocol for the 29k) and the 88k bug monitor. It is now an
6875 integer specifying a debug level (normally 0 or 1, but 2 means more
6876 debugging info for the mips target).
6878 * DEC Alpha native support
6880 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6881 debug info, but GDB works fairly well with the DEC compiler and should
6882 work with a future GCC release. See the README file for a few
6883 Alpha-specific notes.
6885 * Preliminary thread implementation
6887 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6889 * LynxOS native and target support for 386
6891 This release has been hosted on LynxOS 2.2, and also can be configured
6892 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6895 * Improvements in C++ mangling/demangling.
6897 This release has much better g++ debugging, specifically in name
6898 mangling/demangling, virtual function calls, print virtual table,
6899 call methods, ...etc.
6901 *** Changes in GDB-4.10:
6903 * User visible changes:
6905 Remote debugging using the GDB-specific (`target remote') protocol now
6906 supports the `load' command. This is only useful if you have some
6907 other way of getting the stub to the target system, and you can put it
6908 somewhere in memory where it won't get clobbered by the download.
6910 Filename completion now works.
6912 When run under emacs mode, the "info line" command now causes the
6913 arrow to point to the line specified. Also, "info line" prints
6914 addresses in symbolic form (as well as hex).
6916 All vxworks based targets now support a user settable option, called
6917 vxworks-timeout. This option represents the number of seconds gdb
6918 should wait for responses to rpc's. You might want to use this if
6919 your vxworks target is, perhaps, a slow software simulator or happens
6920 to be on the far side of a thin network line.
6924 This release contains support for using a DEC alpha as a GDB host for
6925 cross debugging. Native alpha debugging is not supported yet.
6928 *** Changes in GDB-4.9:
6932 This is the first GDB release which is accompanied by a matching testsuite.
6933 The testsuite requires installation of dejagnu, which should be available
6934 via ftp from most sites that carry GNU software.
6938 'Cfront' style demangling has had its name changed to 'ARM' style, to
6939 emphasize that it was written from the specifications in the C++ Annotated
6940 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6941 disclaimers, it still generated too much confusion with users attempting to
6942 use gdb with AT&T cfront.
6946 GDB now uses a standard remote interface to a simulator library.
6947 So far, the library contains simulators for the Zilog Z8001/2, the
6948 Hitachi H8/300, H8/500 and Super-H.
6950 * New targets supported
6952 H8/300 simulator h8300-hitachi-hms or h8300hms
6953 H8/500 simulator h8500-hitachi-hms or h8500hms
6954 SH simulator sh-hitachi-hms or sh
6955 Z8000 simulator z8k-zilog-none or z8ksim
6956 IDT MIPS board over serial line mips-idt-ecoff
6958 Cross-debugging to GO32 targets is supported. It requires a custom
6959 version of the i386-stub.c module which is integrated with the
6960 GO32 memory extender.
6962 * New remote protocols
6964 MIPS remote debugging protocol.
6966 * New source languages supported
6968 This version includes preliminary support for Chill, a Pascal like language
6969 used by telecommunications companies. Chill support is also being integrated
6970 into the GNU compiler, but we don't know when it will be publically available.
6973 *** Changes in GDB-4.8:
6975 * HP Precision Architecture supported
6977 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6978 version of this support was available as a set of patches from the
6979 University of Utah. GDB does not support debugging of programs
6980 compiled with the HP compiler, because HP will not document their file
6981 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6982 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6984 Many problems in the preliminary version have been fixed.
6986 * Faster and better demangling
6988 We have improved template demangling and fixed numerous bugs in the GNU style
6989 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6990 character types (wchar_t) are now supported. Demangling of each symbol is now
6991 only done once, and is cached when the symbol table for a file is read in.
6992 This results in a small increase in memory usage for C programs, a moderate
6993 increase in memory usage for C++ programs, and a fantastic speedup in
6996 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6997 from the specifications in the Annotated Reference Manual, which AT&T's
6998 compiler does not actually implement.
7000 * G++ multiple inheritance compiler problem
7002 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7003 inheritance lattices was reworked to properly discover ambiguities. We
7004 recently found an example which causes this new algorithm to fail in a
7005 very subtle way, producing bad debug information for those classes.
7006 The file 'gcc.patch' (in this directory) can be applied to gcc to
7007 circumvent the problem. A future GCC release will contain a complete
7010 The previous G++ debug info problem (mentioned below for the gdb-4.7
7011 release) is fixed in gcc version 2.3.2.
7013 * Improved configure script
7015 The `configure' script will now attempt to guess your system type if
7016 you don't supply a host system type. The old scheme of supplying a
7017 host system triplet is preferable over using this. All the magic is
7018 done in the new `config.guess' script. Examine it for details.
7020 We have also brought our configure script much more in line with the FSF's
7021 version. It now supports the --with-xxx options. In particular,
7022 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7023 The resulting GDB will not be able to read arbitrary object file formats --
7024 only the format ``expected'' to be used on the configured target system.
7025 We hope to make this the default in a future release.
7027 * Documentation improvements
7029 There's new internal documentation on how to modify GDB, and how to
7030 produce clean changes to the code. We implore people to read it
7031 before submitting changes.
7033 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7034 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7035 `info' files are also provided. To build `info' files from scratch,
7036 you will need the latest `makeinfo' release, which will be available in
7037 a future texinfo-X.Y release.
7039 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7040 We're not sure exactly which versions have this problem, but it has
7041 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7042 or better. If that isn't possible, there is a patch in
7043 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7044 around this problem.
7048 GDB now supports array constants that can be used in expressions typed in by
7049 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7050 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7053 The new directory `gdb/sparclite' contains a program that demonstrates
7054 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7056 * New native hosts supported
7058 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7059 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7061 * New targets supported
7063 AMD 29k family via UDI a29k-amd-udi or udi29k
7065 * New file formats supported
7067 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7068 HPUX core files, and SCO 3.2v2 core files.
7072 Attaching to processes now works again; thanks for the many bug reports.
7074 We have also stomped on a bunch of core dumps caused by
7075 printf_filtered("%s") problems.
7077 We eliminated a copyright problem on the rpc and ptrace header files
7078 for VxWorks, which was discovered at the last minute during the 4.7
7079 release. You should now be able to build a VxWorks GDB.
7081 You can now interrupt gdb while an attached process is running. This
7082 will cause the attached process to stop, and give control back to GDB.
7084 We fixed problems caused by using too many file descriptors
7085 for reading symbols from object files and libraries. This was
7086 especially a problem for programs that used many (~100) shared
7089 The `step' command now only enters a subroutine if there is line number
7090 information for the subroutine. Otherwise it acts like the `next'
7091 command. Previously, `step' would enter subroutines if there was
7092 any debugging information about the routine. This avoids problems
7093 when using `cc -g1' on MIPS machines.
7095 * Internal improvements
7097 GDB's internal interfaces have been improved to make it easier to support
7098 debugging of multiple languages in the future.
7100 GDB now uses a common structure for symbol information internally.
7101 Minimal symbols (derived from linkage symbols in object files), partial
7102 symbols (from a quick scan of debug information), and full symbols
7103 contain a common subset of information, making it easier to write
7104 shared code that handles any of them.
7106 * New command line options
7108 We now accept --silent as an alias for --quiet.
7112 The memory-mapped-malloc library is now licensed under the GNU Library
7113 General Public License.
7115 *** Changes in GDB-4.7:
7117 * Host/native/target split
7119 GDB has had some major internal surgery to untangle the support for
7120 hosts and remote targets. Now, when you configure GDB for a remote
7121 target, it will no longer load in all of the support for debugging
7122 local programs on the host. When fully completed and tested, this will
7123 ensure that arbitrary host/target combinations are possible.
7125 The primary conceptual shift is to separate the non-portable code in
7126 GDB into three categories. Host specific code is required any time GDB
7127 is compiled on that host, regardless of the target. Target specific
7128 code relates to the peculiarities of the target, but can be compiled on
7129 any host. Native specific code is everything else: it can only be
7130 built when the host and target are the same system. Child process
7131 handling and core file support are two common `native' examples.
7133 GDB's use of /proc for controlling Unix child processes is now cleaner.
7134 It has been split out into a single module under the `target_ops' vector,
7135 plus two native-dependent functions for each system that uses /proc.
7137 * New hosts supported
7139 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7140 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7141 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7143 * New targets supported
7145 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7146 68030 and CPU32 m68030-*-*, m68332-*-*
7148 * New native hosts supported
7150 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7151 (386bsd is not well tested yet)
7152 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7154 * New file formats supported
7156 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7157 supports reading of `a.out.adobe' object files, which are an a.out
7158 format extended with minimal information about multiple sections.
7162 `show copying' is the same as the old `info copying'.
7163 `show warranty' is the same as `info warrantee'.
7164 These were renamed for consistency. The old commands continue to work.
7166 `info handle' is a new alias for `info signals'.
7168 You can now define pre-command hooks, which attach arbitrary command
7169 scripts to any command. The commands in the hook will be executed
7170 prior to the user's command. You can also create a hook which will be
7171 executed whenever the program stops. See gdb.texinfo.
7175 We now deal with Cfront style name mangling, and can even extract type
7176 info from mangled symbols. GDB can automatically figure out which
7177 symbol mangling style your C++ compiler uses.
7179 Calling of methods and virtual functions has been improved as well.
7183 The crash that occured when debugging Sun Ansi-C compiled binaries is
7184 fixed. This was due to mishandling of the extra N_SO stabs output
7187 We also finally got Ultrix 4.2 running in house, and fixed core file
7188 support, with help from a dozen people on the net.
7190 John M. Farrell discovered that the reason that single-stepping was so
7191 slow on all of the Mips based platforms (primarily SGI and DEC) was
7192 that we were trying to demangle and lookup a symbol used for internal
7193 purposes on every instruction that was being stepped through. Changing
7194 the name of that symbol so that it couldn't be mistaken for a C++
7195 mangled symbol sped things up a great deal.
7197 Rich Pixley sped up symbol lookups in general by getting much smarter
7198 about when C++ symbol mangling is necessary. This should make symbol
7199 completion (TAB on the command line) much faster. It's not as fast as
7200 we'd like, but it's significantly faster than gdb-4.6.
7204 A new user controllable variable 'call_scratch_address' can
7205 specify the location of a scratch area to be used when GDB
7206 calls a function in the target. This is necessary because the
7207 usual method of putting the scratch area on the stack does not work
7208 in systems that have separate instruction and data spaces.
7210 We integrated changes to support the 29k UDI (Universal Debugger
7211 Interface), but discovered at the last minute that we didn't have all
7212 of the appropriate copyright paperwork. We are working with AMD to
7213 resolve this, and hope to have it available soon.
7217 We have sped up the remote serial line protocol, especially for targets
7218 with lots of registers. It now supports a new `expedited status' ('T')
7219 message which can be used in place of the existing 'S' status message.
7220 This allows the remote stub to send only the registers that GDB
7221 needs to make a quick decision about single-stepping or conditional
7222 breakpoints, eliminating the need to fetch the entire register set for
7223 each instruction being stepped through.
7225 The GDB remote serial protocol now implements a write-through cache for
7226 registers, only re-reading the registers if the target has run.
7228 There is also a new remote serial stub for SPARC processors. You can
7229 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7230 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7231 processor with a serial port.
7235 Configure.in files have become much easier to read and modify. A new
7236 `table driven' format makes it more obvious what configurations are
7237 supported, and what files each one uses.
7241 There is a new opcodes library which will eventually contain all of the
7242 disassembly routines and opcode tables. At present, it only contains
7243 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7244 disassembler (binutils/objdump) to share these routines.
7246 The libiberty library is now copylefted under the GNU Library General
7247 Public License. This allows more liberal use, and was done so libg++
7248 can use it. This makes no difference to GDB, since the Library License
7249 grants all the rights from the General Public License.
7253 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7254 reference to the stabs symbol info used by the debugger. It is (as far
7255 as we know) the only published document on this fascinating topic. We
7256 encourage you to read it, compare it to the stabs information on your
7257 system, and send improvements on the document in general (to
7258 bug-gdb@prep.ai.mit.edu).
7260 And, of course, many bugs have been fixed.
7263 *** Changes in GDB-4.6:
7265 * Better support for C++ function names
7267 GDB now accepts as input the "demangled form" of C++ overloaded function
7268 names and member function names, and can do command completion on such names
7269 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7270 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7271 Make use of command completion, it is your friend.
7273 GDB also now accepts a variety of C++ mangled symbol formats. They are
7274 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7275 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7276 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7277 for the list of formats.
7279 * G++ symbol mangling problem
7281 Recent versions of gcc have a bug in how they emit debugging information for
7282 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7283 directory) can be applied to gcc to fix the problem. Alternatively, if you
7284 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7285 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7286 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7289 * New 'maintenance' command
7291 All of the commands related to hacking GDB internals have been moved out of
7292 the main command set, and now live behind the 'maintenance' command. This
7293 can also be abbreviated as 'mt'. The following changes were made:
7295 dump-me -> maintenance dump-me
7296 info all-breakpoints -> maintenance info breakpoints
7297 printmsyms -> maintenance print msyms
7298 printobjfiles -> maintenance print objfiles
7299 printpsyms -> maintenance print psymbols
7300 printsyms -> maintenance print symbols
7302 The following commands are new:
7304 maintenance demangle Call internal GDB demangler routine to
7305 demangle a C++ link name and prints the result.
7306 maintenance print type Print a type chain for a given symbol
7308 * Change to .gdbinit file processing
7310 We now read the $HOME/.gdbinit file before processing the argv arguments
7311 (e.g. reading symbol files or core files). This allows global parameters to
7312 be set, which will apply during the symbol reading. The ./.gdbinit is still
7313 read after argv processing.
7315 * New hosts supported
7317 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7319 GNU/Linux support i386-unknown-linux or linux
7321 We are also including code to support the HP/PA running BSD and HPUX. This
7322 is almost guaranteed not to work, as we didn't have time to test or build it
7323 for this release. We are including it so that the more adventurous (or
7324 masochistic) of you can play with it. We also had major problems with the
7325 fact that the compiler that we got from HP doesn't support the -g option.
7328 * New targets supported
7330 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7332 * More smarts about finding #include files
7334 GDB now remembers the compilation directory for all include files, and for
7335 all files from which C is generated (like yacc and lex sources). This
7336 greatly improves GDB's ability to find yacc/lex sources, and include files,
7337 especially if you are debugging your program from a directory different from
7338 the one that contains your sources.
7340 We also fixed a bug which caused difficulty with listing and setting
7341 breakpoints in include files which contain C code. (In the past, you had to
7342 try twice in order to list an include file that you hadn't looked at before.)
7344 * Interesting infernals change
7346 GDB now deals with arbitrary numbers of sections, where the symbols for each
7347 section must be relocated relative to that section's landing place in the
7348 target's address space. This work was needed to support ELF with embedded
7349 stabs used by Solaris-2.0.
7351 * Bug fixes (of course!)
7353 There have been loads of fixes for the following things:
7354 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7355 i960, stabs, DOS(GO32), procfs, etc...
7357 See the ChangeLog for details.
7359 *** Changes in GDB-4.5:
7361 * New machines supported (host and target)
7363 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7365 SGI Irix-4.x mips-sgi-irix4 or iris4
7367 * New malloc package
7369 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7370 Mmalloc is capable of handling mutiple heaps of memory. It is also
7371 capable of saving a heap to a file, and then mapping it back in later.
7372 This can be used to greatly speedup the startup of GDB by using a
7373 pre-parsed symbol table which lives in a mmalloc managed heap. For
7374 more details, please read mmalloc/mmalloc.texi.
7378 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7379 'help info proc' for details.
7381 * MIPS ecoff symbol table format
7383 The code that reads MIPS symbol table format is now supported on all hosts.
7384 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7387 * File name changes for MS-DOS
7389 Many files in the config directories have been renamed to make it easier to
7390 support GDB on MS-DOSe systems (which have very restrictive file name
7391 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7392 environment) is close to working but has some remaining problems. Note
7393 that debugging of DOS programs is not supported, due to limitations
7394 in the ``operating system'', but it can be used to host cross-debugging.
7396 * Cross byte order fixes
7398 Many fixes have been made to support cross debugging of Sparc and MIPS
7399 targets from hosts whose byte order differs.
7401 * New -mapped and -readnow options
7403 If memory-mapped files are available on your system through the 'mmap'
7404 system call, you can use the -mapped option on the `file' or
7405 `symbol-file' commands to cause GDB to write the symbols from your
7406 program into a reusable file. If the program you are debugging is
7407 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7408 Future GDB debugging sessions will notice the presence of this file,
7409 and will quickly map in symbol information from it, rather than reading
7410 the symbol table from the executable program. Using the '-mapped'
7411 option in a GDB `file' or `symbol-file' command has the same effect as
7412 starting GDB with the '-mapped' command-line option.
7414 You can cause GDB to read the entire symbol table immediately by using
7415 the '-readnow' option with any of the commands that load symbol table
7416 information (or on the GDB command line). This makes the command
7417 slower, but makes future operations faster.
7419 The -mapped and -readnow options are typically combined in order to
7420 build a `fred.syms' file that contains complete symbol information.
7421 A simple GDB invocation to do nothing but build a `.syms' file for future
7424 gdb -batch -nx -mapped -readnow programname
7426 The `.syms' file is specific to the host machine on which GDB is run.
7427 It holds an exact image of GDB's internal symbol table. It cannot be
7428 shared across multiple host platforms.
7430 * longjmp() handling
7432 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7433 siglongjmp() without losing control. This feature has not yet been ported to
7434 all systems. It currently works on many 386 platforms, all MIPS-based
7435 platforms (SGI, DECstation, etc), and Sun3/4.
7439 Preliminary work has been put in to support the new Solaris OS from Sun. At
7440 this time, it can control and debug processes, but it is not capable of
7445 As always, many many bug fixes. The major areas were with g++, and mipsread.
7446 People using the MIPS-based platforms should experience fewer mysterious
7447 crashes and trashed symbol tables.
7449 *** Changes in GDB-4.4:
7451 * New machines supported (host and target)
7453 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7455 BSD Reno on Vax vax-dec-bsd
7456 Ultrix on Vax vax-dec-ultrix
7458 * New machines supported (target)
7460 AMD 29000 embedded, using EBMON a29k-none-none
7464 GDB continues to improve its handling of C++. `References' work better.
7465 The demangler has also been improved, and now deals with symbols mangled as
7466 per the Annotated C++ Reference Guide.
7468 GDB also now handles `stabs' symbol information embedded in MIPS
7469 `ecoff' symbol tables. Since the ecoff format was not easily
7470 extensible to handle new languages such as C++, this appeared to be a
7471 good way to put C++ debugging info into MIPS binaries. This option
7472 will be supported in the GNU C compiler, version 2, when it is
7475 * New features for SVR4
7477 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7478 shared libraries. Debugging dynamically linked programs should present
7479 only minor differences from debugging statically linked programs.
7481 The `info proc' command will print out information about any process
7482 on an SVR4 system (including the one you are debugging). At the moment,
7483 it prints the address mappings of the process.
7485 If you bring up GDB on another SVR4 system, please send mail to
7486 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7488 * Better dynamic linking support in SunOS
7490 Reading symbols from shared libraries which contain debugging symbols
7491 now works properly. However, there remain issues such as automatic
7492 skipping of `transfer vector' code during function calls, which
7493 make it harder to debug code in a shared library, than to debug the
7494 same code linked statically.
7498 GDB is now using the latest `getopt' routines from the FSF. This
7499 version accepts the -- prefix for options with long names. GDB will
7500 continue to accept the old forms (-option and +option) as well.
7501 Various single letter abbreviations for options have been explicity
7502 added to the option table so that they won't get overshadowed in the
7503 future by other options that begin with the same letter.
7507 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7508 Many assorted bugs have been handled. Many more remain to be handled.
7509 See the various ChangeLog files (primarily in gdb and bfd) for details.
7512 *** Changes in GDB-4.3:
7514 * New machines supported (host and target)
7516 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7517 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7518 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7520 * Almost SCO Unix support
7522 We had hoped to support:
7523 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7524 (except for core file support), but we discovered very late in the release
7525 that it has problems with process groups that render gdb unusable. Sorry
7526 about that. I encourage people to fix it and post the fixes.
7528 * Preliminary ELF and DWARF support
7530 GDB can read ELF object files on System V Release 4, and can handle
7531 debugging records for C, in DWARF format, in ELF files. This support
7532 is preliminary. If you bring up GDB on another SVR4 system, please
7533 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7538 GDB now uses the latest `readline' library. One user-visible change
7539 is that two tabs will list possible command completions, which previously
7540 required typing M-? (meta-question mark, or ESC ?).
7544 The `stepi' bug that many of you noticed has been squashed.
7545 Many bugs in C++ have been handled. Many more remain to be handled.
7546 See the various ChangeLog files (primarily in gdb and bfd) for details.
7548 * State of the MIPS world (in case you wondered):
7550 GDB can understand the symbol tables emitted by the compilers
7551 supplied by most vendors of MIPS-based machines, including DEC. These
7552 symbol tables are in a format that essentially nobody else uses.
7554 Some versions of gcc come with an assembler post-processor called
7555 mips-tfile. This program is required if you want to do source-level
7556 debugging of gcc-compiled programs. I believe FSF does not ship
7557 mips-tfile with gcc version 1, but it will eventually come with gcc
7560 Debugging of g++ output remains a problem. g++ version 1.xx does not
7561 really support it at all. (If you're lucky, you should be able to get
7562 line numbers and stack traces to work, but no parameters or local
7563 variables.) With some work it should be possible to improve the
7566 When gcc version 2 is released, you will have somewhat better luck.
7567 However, even then you will get confusing results for inheritance and
7570 We will eventually provide full debugging of g++ output on
7571 DECstations. This will probably involve some kind of stabs-in-ecoff
7572 encapulation, but the details have not been worked out yet.
7575 *** Changes in GDB-4.2:
7577 * Improved configuration
7579 Only one copy of `configure' exists now, and it is not self-modifying.
7580 Porting BFD is simpler.
7584 The `step' and `next' commands now only stop at the first instruction
7585 of a source line. This prevents the multiple stops that used to occur
7586 in switch statements, for-loops, etc. `Step' continues to stop if a
7587 function that has debugging information is called within the line.
7591 Lots of small bugs fixed. More remain.
7593 * New host supported (not target)
7595 Intel 386 PC clone running Mach i386-none-mach
7598 *** Changes in GDB-4.1:
7600 * Multiple source language support
7602 GDB now has internal scaffolding to handle several source languages.
7603 It determines the type of each source file from its filename extension,
7604 and will switch expression parsing and number formatting to match the
7605 language of the function in the currently selected stack frame.
7606 You can also specifically set the language to be used, with
7607 `set language c' or `set language modula-2'.
7611 GDB now has preliminary support for the GNU Modula-2 compiler,
7612 currently under development at the State University of New York at
7613 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7614 continue through the fall of 1991 and into 1992.
7616 Other Modula-2 compilers are currently not supported, and attempting to
7617 debug programs compiled with them will likely result in an error as the
7618 symbol table is read. Feel free to work on it, though!
7620 There are hooks in GDB for strict type checking and range checking,
7621 in the `Modula-2 philosophy', but they do not currently work.
7625 GDB can now write to executable and core files (e.g. patch
7626 a variable's value). You must turn this switch on, specify
7627 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7628 by assigning a new value to a variable. Modifications take
7631 * Automatic SunOS shared library reading
7633 When you run your program, GDB automatically determines where its
7634 shared libraries (if any) have been loaded, and reads their symbols.
7635 The `share' command is no longer needed. This also works when
7636 examining core files.
7640 You can specify the number of lines that the `list' command shows.
7643 * New machines supported (host and target)
7645 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7646 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7647 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7649 * New hosts supported (not targets)
7651 IBM RT/PC: romp-ibm-aix or rtpc
7653 * New targets supported (not hosts)
7655 AMD 29000 embedded with COFF a29k-none-coff
7656 AMD 29000 embedded with a.out a29k-none-aout
7657 Ultracomputer remote kernel debug a29k-nyu-kern
7659 * New remote interfaces
7665 *** Changes in GDB-4.0:
7669 Wide output is wrapped at good places to make the output more readable.
7671 Gdb now supports cross-debugging from a host machine of one type to a
7672 target machine of another type. Communication with the target system
7673 is over serial lines. The ``target'' command handles connecting to the
7674 remote system; the ``load'' command will download a program into the
7675 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7676 also supports debugging of realtime processes running under VxWorks,
7677 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7678 stub on the target system.
7680 New CPUs supported include the AMD 29000 and Intel 960.
7682 GDB now reads object files and symbol tables via a ``binary file''
7683 library, which allows a single copy of GDB to debug programs of multiple
7684 object file types such as a.out and coff.
7686 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7687 refcard.dvi and refcard.ps are available to format it).
7690 * Control-Variable user interface simplified
7692 All variables that control the operation of the debugger can be set
7693 by the ``set'' command, and displayed by the ``show'' command.
7695 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7696 ``Show prompt'' produces the response:
7697 Gdb's prompt is new-gdb=>.
7699 What follows are the NEW set commands. The command ``help set'' will
7700 print a complete list of old and new set commands. ``help set FOO''
7701 will give a longer description of the variable FOO. ``show'' will show
7702 all of the variable descriptions and their current settings.
7704 confirm on/off: Enables warning questions for operations that are
7705 hard to recover from, e.g. rerunning the program while
7706 it is already running. Default is ON.
7708 editing on/off: Enables EMACS style command line editing
7709 of input. Previous lines can be recalled with
7710 control-P, the current line can be edited with control-B,
7711 you can search for commands with control-R, etc.
7714 history filename NAME: NAME is where the gdb command history
7715 will be stored. The default is .gdb_history,
7716 or the value of the environment variable
7719 history size N: The size, in commands, of the command history. The
7720 default is 256, or the value of the environment variable
7723 history save on/off: If this value is set to ON, the history file will
7724 be saved after exiting gdb. If set to OFF, the
7725 file will not be saved. The default is OFF.
7727 history expansion on/off: If this value is set to ON, then csh-like
7728 history expansion will be performed on
7729 command line input. The default is OFF.
7731 radix N: Sets the default radix for input and output. It can be set
7732 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7733 in the current radix, so "set radix 10" is always a no-op.
7735 height N: This integer value is the number of lines on a page. Default
7736 is 24, the current `stty rows'' setting, or the ``li#''
7737 setting from the termcap entry matching the environment
7740 width N: This integer value is the number of characters on a line.
7741 Default is 80, the current `stty cols'' setting, or the ``co#''
7742 setting from the termcap entry matching the environment
7745 Note: ``set screensize'' is obsolete. Use ``set height'' and
7746 ``set width'' instead.
7748 print address on/off: Print memory addresses in various command displays,
7749 such as stack traces and structure values. Gdb looks
7750 more ``symbolic'' if you turn this off; it looks more
7751 ``machine level'' with it on. Default is ON.
7753 print array on/off: Prettyprint arrays. New convenient format! Default
7756 print demangle on/off: Print C++ symbols in "source" form if on,
7759 print asm-demangle on/off: Same, for assembler level printouts
7762 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7765 * Support for Epoch Environment.
7767 The epoch environment is a version of Emacs v18 with windowing. One
7768 new command, ``inspect'', is identical to ``print'', except that if you
7769 are running in the epoch environment, the value is printed in its own
7773 * Support for Shared Libraries
7775 GDB can now debug programs and core files that use SunOS shared libraries.
7776 Symbols from a shared library cannot be referenced
7777 before the shared library has been linked with the program (this
7778 happens after you type ``run'' and before the function main() is entered).
7779 At any time after this linking (including when examining core files
7780 from dynamically linked programs), gdb reads the symbols from each
7781 shared library when you type the ``sharedlibrary'' command.
7782 It can be abbreviated ``share''.
7784 sharedlibrary REGEXP: Load shared object library symbols for files
7785 matching a unix regular expression. No argument
7786 indicates to load symbols for all shared libraries.
7788 info sharedlibrary: Status of loaded shared libraries.
7793 A watchpoint stops execution of a program whenever the value of an
7794 expression changes. Checking for this slows down execution
7795 tremendously whenever you are in the scope of the expression, but is
7796 quite useful for catching tough ``bit-spreader'' or pointer misuse
7797 problems. Some machines such as the 386 have hardware for doing this
7798 more quickly, and future versions of gdb will use this hardware.
7800 watch EXP: Set a watchpoint (breakpoint) for an expression.
7802 info watchpoints: Information about your watchpoints.
7804 delete N: Deletes watchpoint number N (same as breakpoints).
7805 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7806 enable N: Re-enables watchpoint number N (same as breakpoints).
7809 * C++ multiple inheritance
7811 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7814 * C++ exception handling
7816 Gdb now supports limited C++ exception handling. Besides the existing
7817 ability to breakpoint on an exception handler, gdb can breakpoint on
7818 the raising of an exception (before the stack is peeled back to the
7821 catch FOO: If there is a FOO exception handler in the dynamic scope,
7822 set a breakpoint to catch exceptions which may be raised there.
7823 Multiple exceptions (``catch foo bar baz'') may be caught.
7825 info catch: Lists all exceptions which may be caught in the
7826 current stack frame.
7829 * Minor command changes
7831 The command ``call func (arg, arg, ...)'' now acts like the print
7832 command, except it does not print or save a value if the function's result
7833 is void. This is similar to dbx usage.
7835 The ``up'' and ``down'' commands now always print the frame they end up
7836 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7837 frames without printing.
7839 * New directory command
7841 'dir' now adds directories to the FRONT of the source search path.
7842 The path starts off empty. Source files that contain debug information
7843 about the directory in which they were compiled can be found even
7844 with an empty path; Sun CC and GCC include this information. If GDB can't
7845 find your source file in the current directory, type "dir .".
7847 * Configuring GDB for compilation
7849 For normal use, type ``./configure host''. See README or gdb.texinfo
7852 GDB now handles cross debugging. If you are remotely debugging between
7853 two different machines, type ``./configure host -target=targ''.
7854 Host is the machine where GDB will run; targ is the machine
7855 where the program that you are debugging will run.