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
44 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
45 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
46 Set or show the option 'exec-file-mismatch'. When GDB attaches to
47 a running process and can determine the name of the executable file
48 the process runs, this new option indicates whether to detect mismatch
49 between the name of the current executable file loaded by GDB
50 and the name of the executable file used to start the process.
51 If 'ask', the default, display a warning and ask the user
52 whether to load the process executable file; if 'warn', just display
53 a warning; if 'off', don't attempt to detect a mismatch.
55 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
56 Define a new TUI layout, specifying its name and the windows that
61 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
65 ** gdb.register_window_type can be used to implement new TUI windows
70 * 'thread-exited' event is now available in the annotations interface.
72 * New built-in convenience variables $_gdb_major and $_gdb_minor
73 provide the GDB version. They are handy for conditionally using
74 features available only in or since specific GDB versions, in
75 scripts that should work error-free with many different versions,
76 such as in system-wide init files.
78 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
79 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
80 of the GDB settings and the GDB maintenance settings. They are handy
81 for changing the logic of user defined commands depending on the
84 * GDB now supports Thread Local Storage (TLS) variables on several
85 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
86 architectures require kernel changes. TLS is not yet supported for
87 amd64 and i386 process core dumps.
89 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
90 addresses that required unmasking are shown in the backtrace with the
93 * Two new convenience functions $_cimag and $_creal that extract the
94 imaginary and real parts respectively from complex numbers.
96 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
97 provide the exitcode or exit status of the shell commands launched by
98 GDB commands such as "shell", "pipe" and "make".
100 * The command define-prefix can now define user defined prefix commands.
101 User defined commands can now be defined using these user defined prefix
104 * Command names can now use the . character.
106 * The RX port now supports XML target descriptions.
108 * GDB now shows the Ada task names at more places, e.g. in task switching
111 * GDB can now be compiled with Python 3 on Windows.
113 * New convenience variable $_ada_exception holds the address of the
114 Ada exception being thrown. This is set by Ada-related catchpoints.
116 * GDB can now place breakpoints on nested functions and subroutines in
117 Fortran code. The '::' operator can be used between parent and
118 child scopes when placing breakpoints, for example:
120 (gdb) break outer_function::inner_function
122 The 'outer_function::' prefix is only needed if 'inner_function' is
123 not visible in the current scope.
125 * In addition to the system-wide gdbinit file, if configured with
126 --with-system-gdbinit-dir, GDB will now also load files in that directory
127 as system gdbinit files, unless the -nx or -n flag is provided. Files
128 with extensions .gdb, .py and .scm are supported as long as GDB was
129 compiled with support for that language.
131 * GDB now supports multithreaded symbol loading for higher performance.
132 This feature is still in testing, so it is disabled by default. You
133 can turn it on using 'maint set worker-threads unlimited'.
135 * Multi-target debugging support
137 GDB now supports debugging multiple target connections
138 simultaneously. For example, you can now have each inferior
139 connected to different remote servers running in different machines,
140 or have one inferior debugging a local native process, an inferior
141 debugging a core dump, etc.
143 This support is experimental and comes with some limitations -- you
144 can only resume multiple targets simultaneously if all targets
145 support non-stop mode, and all remote stubs or servers must support
146 the same set of remote protocol features exactly. See also "info
147 connections" and "add-inferior -no-connection" below, and "maint set
148 target-non-stop" in the user manual.
152 ** The gdb.Value type has a new method 'format_string' which returns a
153 string representing the value. The formatting is controlled by the
154 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
155 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
156 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
158 ** gdb.Type has a new property 'objfile' which returns the objfile the
161 ** The frame information printed by the python frame filtering code
162 is now consistent with what the 'backtrace' command prints when
163 there are no filters, or when the 'backtrace' '-no-filters' option
166 ** The new function gdb.lookup_static_symbol can be used to look up
167 symbols with static linkage.
169 ** The new function gdb.lookup_static_symbols can be used to look up
170 all static symbols with static linkage.
172 ** gdb.Objfile has new methods 'lookup_global_symbol' and
173 'lookup_static_symbol' to lookup a symbol from this objfile only.
175 ** gdb.Block now supports the dictionary syntax for accessing symbols in
176 this block (e.g. block['local_variable']).
180 | [COMMAND] | SHELL_COMMAND
181 | -d DELIM COMMAND DELIM SHELL_COMMAND
182 pipe [COMMAND] | SHELL_COMMAND
183 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
184 Executes COMMAND and sends its output to SHELL_COMMAND.
185 With no COMMAND, repeat the last executed command
186 and send its output to SHELL_COMMAND.
188 define-prefix COMMAND
189 Define or mark a command as a user-defined prefix command.
191 with SETTING [VALUE] [-- COMMAND]
192 w SETTING [VALUE] [-- COMMAND]
193 Temporarily set SETTING, run COMMAND, and restore SETTING.
194 Usage: with SETTING -- COMMAND
195 With no COMMAND, repeats the last executed command.
196 SETTING is any GDB setting you can change with the "set"
197 subcommands. For example, 'with language c -- print someobj'
198 temporarily switches to the C language in order to print someobj.
199 Settings can be combined: 'w lang c -- w print elements unlimited --
200 usercmd' switches to the C language and runs usercmd with no limit
201 of array elements to print.
203 maint with SETTING [VALUE] [-- COMMAND]
204 Like "with", but works with "maintenance set" settings.
206 set may-call-functions [on|off]
207 show may-call-functions
208 This controls whether GDB will attempt to call functions in
209 the program, such as with expressions in the print command. It
210 defaults to on. Calling functions in the program being debugged
211 can have undesired side effects. It is now possible to forbid
212 such function calls. If function calls are forbidden, GDB will throw
213 an error when a command (such as print expression) calls a function
216 set print finish [on|off]
218 This controls whether the `finish' command will display the value
219 that is returned by the current function. When `off', the value is
220 still entered into the value history, but it is not printed. The
225 Allows deeply nested structures to be simplified when printing by
226 replacing deeply nested parts (beyond the max-depth) with ellipses.
227 The default max-depth is 20, but this can be set to unlimited to get
228 the old behavior back.
230 set print raw-values [on|off]
231 show print raw-values
232 By default, GDB applies the enabled pretty printers when printing a
233 value. This allows to ignore the enabled pretty printers for a series
234 of commands. The default is 'off'.
236 set logging debugredirect [on|off]
237 By default, GDB debug output will go to both the terminal and the logfile.
238 Set if you want debug output to go only to the log file.
240 set style title foreground COLOR
241 set style title background COLOR
242 set style title intensity VALUE
243 Control the styling of titles.
245 set style highlight foreground COLOR
246 set style highlight background COLOR
247 set style highlight intensity VALUE
248 Control the styling of highlightings.
250 maint set worker-threads
251 maint show worker-threads
252 Control the number of worker threads that can be used by GDB. The
253 default is 0. "unlimited" lets GDB choose a number that is
254 reasonable. Currently worker threads are only used when demangling
255 the names of linker symbols.
257 set style tui-border foreground COLOR
258 set style tui-border background COLOR
259 Control the styling of TUI borders.
261 set style tui-active-border foreground COLOR
262 set style tui-active-border background COLOR
263 Control the styling of the active TUI border.
265 maint set test-settings KIND
266 maint show test-settings KIND
267 A set of commands used by the testsuite for exercising the settings
270 maint set tui-resize-message [on|off]
271 maint show tui-resize-message
272 Control whether GDB prints a message each time the terminal is
273 resized when in TUI mode. This is primarily useful for testing the
276 set print frame-info [short-location|location|location-and-address
277 |source-and-location|source-line|auto]
278 show print frame-info
279 This controls what frame information is printed by the commands printing
280 a frame. This setting will e.g. influence the behaviour of 'backtrace',
281 'frame', 'stepi'. The python frame filtering also respect this setting.
282 The 'backtrace' '-frame-info' option can override this global setting.
284 set tui compact-source
285 show tui compact-source
287 Enable the "compact" display mode for the TUI source window. The
288 compact display uses only as much space as is needed for the line
289 numbers in the current file, and only a single space to separate the
290 line numbers from the source.
292 info modules [-q] [REGEXP]
293 Return a list of Fortran modules matching REGEXP, or all modules if
296 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
297 Return a list of functions within all modules, grouped by module.
298 The list of functions can be restricted with the optional regular
299 expressions. MODULE_REGEXP matches against the module name,
300 TYPE_REGEXP matches against the function type signature, and REGEXP
301 matches against the function name.
303 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
304 Return a list of variables within all modules, grouped by module.
305 The list of variables can be restricted with the optional regular
306 expressions. MODULE_REGEXP matches against the module name,
307 TYPE_REGEXP matches against the variable type, and REGEXP matches
308 against the variable name.
310 set debug remote-packet-max-chars
311 show debug remote-packet-max-chars
312 Controls the number of characters to output in a remote packet when using
314 The default is 512 bytes.
317 Lists the target connections currently in use.
322 The "help" command uses the title style to enhance the
323 readibility of its output by styling the classes and
327 Similarly to "help", the "apropos" command also uses the
328 title style for the command names. "apropos" accepts now
329 a flag "-v" (verbose) to show the full documentation
330 of matching commands and to use the highlight style to mark
331 the documentation parts matching REGEXP.
335 The GDB printf and eval commands can now print C-style and Ada-style
336 string convenience variables without calling functions in the program.
337 This allows to do formatted printing of strings without having
338 a running inferior, or when debugging a core dump.
340 info sources [-dirname | -basename] [--] [REGEXP]
341 This command has now optional arguments to only print the files
342 whose names match REGEXP. The arguments -dirname and -basename
343 allow to restrict matching respectively to the dirname and basename
347 The "show style" and its subcommands are now styling
348 a style name in their output using its own style, to help
349 the user visualize the different styles.
351 set print frame-arguments
352 The new value 'presence' indicates to only indicate the presence of
353 arguments using ..., instead of printing argument names and values.
355 set print raw-frame-arguments
356 show print raw-frame-arguments
358 These commands replace the similarly-named "set/show print raw
359 frame-arguments" commands (now with a dash instead of a space). The
360 old commands are now deprecated and may be removed in a future
363 add-inferior [-no-connection]
364 The add-inferior command now supports a "-no-connection" flag that
365 makes the new inferior start with no target connection associated.
366 By default, the new inferior inherits the target connection of the
367 current inferior. See also "info connections".
370 This command's output now includes a new "Connection" column
371 indicating which target connection an inferior is bound to. See
372 "info connections" above.
374 maint test-options require-delimiter
375 maint test-options unknown-is-error
376 maint test-options unknown-is-operand
377 maint show test-options-completion-result
378 Commands used by the testsuite to validate the command options
381 focus, winheight, +, -, >, <
382 These commands are now case-sensitive.
384 * New command options, command completion
386 GDB now has a standard infrastructure to support dash-style command
387 options ('-OPT'). One benefit is that commands that use it can
388 easily support completion of command line arguments. Try "CMD
389 -[TAB]" or "help CMD" to find options supported by a command. Over
390 time, we intend to migrate most commands to this infrastructure. A
391 number of commands got support for new command options in this
394 ** The "print" and "compile print" commands now support a number of
395 options that allow overriding relevant global print settings as
396 set by "set print" subcommands:
400 -array-indexes [on|off]
401 -elements NUMBER|unlimited
406 -repeats NUMBER|unlimited
407 -static-members [on|off]
412 Note that because the "print"/"compile print" commands accept
413 arbitrary expressions which may look like options (including
414 abbreviations), if you specify any command option, then you must
415 use a double dash ("--") to mark the end of argument processing.
417 ** The "backtrace" command now supports a number of options that
418 allow overriding relevant global print settings as set by "set
419 backtrace" and "set print" subcommands:
421 -entry-values no|only|preferred|if-needed|both|compact|default
422 -frame-arguments all|scalars|none
423 -raw-frame-arguments [on|off]
424 -frame-info auto|source-line|location|source-and-location
425 |location-and-address|short-location
429 In addition, the full/no-filters/hide qualifiers are now also
430 exposed as command options too:
436 ** The "frame apply", "tfaas" and "faas" commands similarly now
437 support the following options:
442 ** The new "info sources" options -dirname and -basename options
443 are using the standard '-OPT' infrastructure.
445 All options above can also be abbreviated. The argument of boolean
446 (on/off) options can be 0/1 too, and also the argument is assumed
447 "on" if omitted. This allows writing compact command invocations,
450 (gdb) p -ra -p -o 0 -- *myptr
452 The above is equivalent to:
454 (gdb) print -raw-values -pretty -object off -- *myptr
456 ** The "info types" command now supports the '-q' flag to disable
457 printing of some header information in a similar fashion to "info
458 variables" and "info functions".
460 ** The "info variables", "info functions", and "whereis" commands
461 now take a '-n' flag that excludes non-debug symbols (symbols
462 from the symbol table, not from the debug info such as DWARF)
465 * Completion improvements
467 ** GDB can now complete the options of the "thread apply all" and
468 "taas" commands, and their "-ascending" option can now be
471 ** GDB can now complete the options of the "info threads", "info
472 functions", "info variables", "info locals", and "info args"
475 ** GDB can now complete the options of the "compile file" and
476 "compile code" commands. The "compile file" command now
477 completes on filenames.
479 ** GDB can now complete the backtrace command's
480 "full/no-filters/hide" qualifiers.
482 * In settings, you can now abbreviate "unlimited".
484 E.g., "set print elements u" is now equivalent to "set print
490 This lists all the possible completions for the rest of the line, if it
491 were to be given as a command itself. This is intended for use by MI
492 frontends in cases when separate CLI and MI channels cannot be used.
494 -catch-throw, -catch-rethrow, and -catch-catch
495 These can be used to catch C++ exceptions in a similar fashion to
496 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
498 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
499 These commands are the MI equivalent of the CLI commands 'info
500 functions', 'info types', and 'info variables' respectively.
502 -symbol-info-modules, this is the MI equivalent of the CLI 'info
505 -symbol-info-module-functions and -symbol-info-module-variables.
506 These commands are the MI equivalent of the CLI commands 'info
507 module functions' and 'info module variables'.
511 ** The default version of the MI interpreter is now 3 (-i=mi3).
513 ** The output of information about multi-location breakpoints (which is
514 syntactically incorrect in MI 2) has changed in MI 3. This affects
515 the following commands and events:
519 - =breakpoint-created
520 - =breakpoint-modified
522 The -fix-multi-location-breakpoint-output command can be used to enable
523 this behavior with previous MI versions.
525 ** Backtraces and frames include a new optional field addr_flags which is
526 given after the addr field. On AArch64 this contains PAC if the address
527 has been masked in the frame. On all other targets the field is not
532 The testsuite now creates the files gdb.cmd (containing the arguments
533 used to launch GDB) and gdb.in (containing all the commands sent to
534 GDB) in the output directory for each test script. Multiple invocations
535 are appended with .1, .2, .3 etc.
537 * Building GDB and GDBserver now requires GNU make >= 3.82.
539 Using another implementation of the make program or an earlier version of
540 GNU make to build GDB or GDBserver is not supported.
542 * Building GDB now requires GNU readline >= 7.0.
544 GDB now bundles GNU readline 8.0, but if you choose to use
545 --with-system-readline, only readline >= 7.0 can be used.
547 * The TUI SingleKey keymap is now named "SingleKey". This can be used
548 from .inputrc to bind keys in this keymap. This feature is only
549 available when gdb is built against GNU readline 8.0 or later.
551 * Removed targets and native configurations
553 GDB no longer supports debugging the Cell Broadband Engine. This includes
554 both debugging standalone Cell/B.E. SPU applications and integrated debugging
555 of Cell/B.E. applications that use both the PPU and SPU architectures.
561 * Removed targets and native configurations
563 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
566 *** Changes in GDB 8.3
568 * GDB and GDBserver now support access to additional registers on
569 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
572 * GDB now has experimental support for the compilation and injection of
573 C++ source code into the inferior. This beta release does not include
574 support for several language features, such as templates, constructors,
577 This feature requires GCC 7.1 or higher built with libcp1.so
580 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
581 can be passed using the '[ADDRESS]:PORT' notation, or the regular
582 'ADDRESS:PORT' method.
584 * DWARF index cache: GDB can now automatically save indices of DWARF
585 symbols on disk to speed up further loading of the same binaries.
587 * Ada task switching is now supported on aarch64-elf targets when
588 debugging a program using the Ravenscar Profile. For more information,
589 see the "Tasking Support when using the Ravenscar Profile" section
590 in the GDB user manual.
592 * GDB in batch mode now exits with status 1 if the last command to be
595 * The RISC-V target now supports target descriptions.
597 * System call catchpoints now support system call aliases on FreeBSD.
598 When the ABI of a system call changes in FreeBSD, this is
599 implemented by leaving a compatibility system call using the old ABI
600 at the existing number and allocating a new system call number for
601 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
602 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
603 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
604 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
605 so that a system call catchpoint for the 'kevent' system call will
606 catch invocations of both the 'kevent' and 'freebsd11_kevent'
607 binaries. This ensures that 'kevent' system calls are caught for
608 binaries using either the old or new ABIs.
610 * Terminal styling is now available for the CLI and the TUI. GNU
611 Source Highlight can additionally be used to provide styling of
612 source code snippets. See the "set style" commands, below, for more
615 * Removed support for old demangling styles arm, edg, gnu, hp and
620 set debug compile-cplus-types
621 show debug compile-cplus-types
622 Control the display of debug output about type conversion in the
623 C++ compile feature. Commands have no effect while compiliong
628 Control whether debug output about files/functions skipping is
631 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
632 Apply a command to some frames.
633 FLAG arguments allow to control what output to produce and how to handle
634 errors raised when applying COMMAND to a frame.
637 Apply a command to all threads (ignoring errors and empty output).
638 Shortcut for 'thread apply all -s COMMAND'.
641 Apply a command to all frames (ignoring errors and empty output).
642 Shortcut for 'frame apply all -s COMMAND'.
645 Apply a command to all frames of all threads (ignoring errors and empty
647 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
649 maint set dwarf unwinders (on|off)
650 maint show dwarf unwinders
651 Control whether DWARF unwinders can be used.
654 Display a list of open files for a process.
658 Changes to the "frame", "select-frame", and "info frame" CLI commands.
659 These commands all now take a frame specification which
660 is either a frame level, or one of the keywords 'level', 'address',
661 'function', or 'view' followed by a parameter. Selecting a frame by
662 address, or viewing a frame outside the current backtrace now
663 requires the use of a keyword. Selecting a frame by level is
664 unchanged. The MI comment "-stack-select-frame" is unchanged.
666 target remote FILENAME
667 target extended-remote FILENAME
668 If FILENAME is a Unix domain socket, GDB will attempt to connect
669 to this socket instead of opening FILENAME as a character device.
671 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
672 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
673 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
674 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
675 These commands can now print only the searched entities
676 matching the provided regexp(s), giving a condition
677 on the entity names or entity types. The flag -q disables
678 printing headers or informations messages.
684 These commands now determine the syntax for the shown entities
685 according to the language chosen by `set language'. In particular,
686 `set language auto' means to automatically choose the language of
689 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
690 The 'thread apply' command accepts new FLAG arguments.
691 FLAG arguments allow to control what output to produce and how to handle
692 errors raised when applying COMMAND to a thread.
694 set tui tab-width NCHARS
695 show tui tab-width NCHARS
696 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
698 set style enabled [on|off]
700 Enable or disable terminal styling. Styling is enabled by default
701 on most hosts, but disabled by default when in batch mode.
703 set style sources [on|off]
705 Enable or disable source code styling. Source code styling is
706 enabled by default, but only takes effect if styling in general is
707 enabled, and if GDB was linked with GNU Source Highlight.
709 set style filename foreground COLOR
710 set style filename background COLOR
711 set style filename intensity VALUE
712 Control the styling of file names.
714 set style function foreground COLOR
715 set style function background COLOR
716 set style function intensity VALUE
717 Control the styling of function names.
719 set style variable foreground COLOR
720 set style variable background COLOR
721 set style variable intensity VALUE
722 Control the styling of variable names.
724 set style address foreground COLOR
725 set style address background COLOR
726 set style address intensity VALUE
727 Control the styling of addresses.
731 ** The '-data-disassemble' MI command now accepts an '-a' option to
732 disassemble the whole function surrounding the given program
733 counter value or function name. Support for this feature can be
734 verified by using the "-list-features" command, which should
735 contain "data-disassemble-a-option".
737 ** Command responses and notifications that include a frame now include
738 the frame's architecture in a new "arch" attribute.
740 * New native configurations
742 GNU/Linux/RISC-V riscv*-*-linux*
743 FreeBSD/riscv riscv*-*-freebsd*
747 GNU/Linux/RISC-V riscv*-*-linux*
749 CSKY GNU/LINUX csky*-*-linux
750 FreeBSD/riscv riscv*-*-freebsd*
752 GNU/Linux/OpenRISC or1k*-*-linux*
756 GDB no longer supports native debugging on versions of MS-Windows
761 ** GDB no longer supports Python versions less than 2.6.
763 ** The gdb.Inferior type has a new 'progspace' property, which is the program
764 space associated to that inferior.
766 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
767 of objfiles associated to that program space.
769 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
770 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
773 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
774 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
775 correct and did not work properly.
777 ** The gdb.Value type has a new constructor, which is used to construct a
778 gdb.Value from a Python buffer object and a gdb.Type.
784 Enable or disable the undefined behavior sanitizer. This is
785 disabled by default, but passing --enable-ubsan=yes or
786 --enable-ubsan=auto to configure will enable it. Enabling this can
787 cause a performance penalty. The undefined behavior sanitizer was
788 first introduced in GCC 4.9.
790 *** Changes in GDB 8.2
792 * The 'set disassembler-options' command now supports specifying options
795 * The 'symbol-file' command now accepts an '-o' option to add a relative
796 offset to all sections.
798 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
799 a relative offset to all sections, but it allows to override the load
800 address of individual sections using '-s'.
802 * The 'add-symbol-file' command no longer requires the second argument
803 (address of the text section).
805 * The endianness used with the 'set endian auto' mode in the absence of
806 an executable selected for debugging is now the last endianness chosen
807 either by one of the 'set endian big' and 'set endian little' commands
808 or by inferring from the last executable used, rather than the startup
811 * The pager now allows a "c" response, meaning to disable the pager
812 for the rest of the current command.
814 * The commands 'info variables/functions/types' now show the source line
815 numbers of symbol definitions when available.
817 * 'info proc' now works on running processes on FreeBSD systems and core
818 files created on FreeBSD systems.
820 * C expressions can now use _Alignof, and C++ expressions can now use
823 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
824 the vector length while the process is running.
830 Control display of debugging info regarding the FreeBSD native target.
832 set|show varsize-limit
833 This new setting allows the user to control the maximum size of Ada
834 objects being printed when those objects have a variable type,
835 instead of that maximum size being hardcoded to 65536 bytes.
837 set|show record btrace cpu
838 Controls the processor to be used for enabling errata workarounds for
841 maint check libthread-db
842 Run integrity checks on the current inferior's thread debugging
845 maint set check-libthread-db (on|off)
846 maint show check-libthread-db
847 Control whether to run integrity checks on inferior specific thread
848 debugging libraries as they are loaded. The default is not to
853 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
855 ** The commands attached to a breakpoint can be set by assigning to
856 the breakpoint's "commands" field.
858 ** gdb.execute can now execute multi-line gdb commands.
860 ** The new functions gdb.convenience_variable and
861 gdb.set_convenience_variable can be used to get and set the value
862 of convenience variables.
864 ** A gdb.Parameter will no longer print the "set" help text on an
865 ordinary "set"; instead by default a "set" will be silent unless
866 the get_set_string method returns a non-empty string.
870 RiscV ELF riscv*-*-elf
872 * Removed targets and native configurations
874 m88k running OpenBSD m88*-*-openbsd*
875 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
876 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
877 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
879 * Aarch64/Linux hardware watchpoints improvements
881 Hardware watchpoints on unaligned addresses are now properly
882 supported when running Linux kernel 4.10 or higher: read and access
883 watchpoints are no longer spuriously missed, and all watchpoints
884 lengths between 1 and 8 bytes are supported. On older kernels,
885 watchpoints set on unaligned addresses are no longer missed, with
886 the tradeoff that there is a possibility of false hits being
891 --enable-codesign=CERT
892 This can be used to invoke "codesign -s CERT" after building gdb.
893 This option is useful on macOS, where code signing is required for
894 gdb to work properly.
896 --disable-gdbcli has been removed
897 This is now silently accepted, but does nothing.
899 *** Changes in GDB 8.1
901 * GDB now supports dynamically creating arbitrary register groups specified
902 in XML target descriptions. This allows for finer grain grouping of
903 registers on systems with a large amount of registers.
905 * The 'ptype' command now accepts a '/o' flag, which prints the
906 offsets and sizes of fields in a struct, like the pahole(1) tool.
908 * New "--readnever" command line option instructs GDB to not read each
909 symbol file's symbolic debug information. This makes startup faster
910 but at the expense of not being able to perform symbolic debugging.
911 This option is intended for use cases where symbolic debugging will
912 not be used, e.g., when you only need to dump the debuggee's core.
914 * GDB now uses the GNU MPFR library, if available, to emulate target
915 floating-point arithmetic during expression evaluation when the target
916 uses different floating-point formats than the host. At least version
917 3.1 of GNU MPFR is required.
919 * GDB now supports access to the guarded-storage-control registers and the
920 software-based guarded-storage broadcast control registers on IBM z14.
922 * On Unix systems, GDB now supports transmitting environment variables
923 that are to be set or unset to GDBserver. These variables will
924 affect the environment to be passed to the remote inferior.
926 To inform GDB of environment variables that are to be transmitted to
927 GDBserver, use the "set environment" command. Only user set
928 environment variables are sent to GDBserver.
930 To inform GDB of environment variables that are to be unset before
931 the remote inferior is started by the GDBserver, use the "unset
932 environment" command.
934 * Completion improvements
936 ** GDB can now complete function parameters in linespecs and
937 explicit locations without quoting. When setting breakpoints,
938 quoting around functions names to help with TAB-completion is
939 generally no longer necessary. For example, this now completes
942 (gdb) b function(in[TAB]
943 (gdb) b function(int)
945 Related, GDB is no longer confused with completing functions in
946 C++ anonymous namespaces:
949 (gdb) b (anonymous namespace)::[TAB][TAB]
950 (anonymous namespace)::a_function()
951 (anonymous namespace)::b_function()
953 ** GDB now has much improved linespec and explicit locations TAB
954 completion support, that better understands what you're
955 completing and offers better suggestions. For example, GDB no
956 longer offers data symbols as possible completions when you're
957 setting a breakpoint.
959 ** GDB now TAB-completes label symbol names.
961 ** The "complete" command now mimics TAB completion accurately.
963 * New command line options (gcore)
966 Dump all memory mappings.
968 * Breakpoints on C++ functions are now set on all scopes by default
970 By default, breakpoints on functions/methods are now interpreted as
971 specifying all functions with the given name ignoring missing
972 leading scopes (namespaces and classes).
974 For example, assuming a C++ program with symbols named:
979 both commands "break func()" and "break B::func()" set a breakpoint
982 You can use the new flag "-qualified" to override this. This makes
983 GDB interpret the specified function name as a complete
984 fully-qualified name instead. For example, using the same C++
985 program, the "break -q B::func" command sets a breakpoint on
986 "B::func", only. A parameter has been added to the Python
987 gdb.Breakpoint constructor to achieve the same result when creating
988 a breakpoint from Python.
990 * Breakpoints on functions marked with C++ ABI tags
992 GDB can now set breakpoints on functions marked with C++ ABI tags
993 (e.g., [abi:cxx11]). See here for a description of ABI tags:
994 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
996 Functions with a C++11 abi tag are demangled/displayed like this:
998 function[abi:cxx11](int)
1001 You can now set a breakpoint on such functions simply as if they had
1004 (gdb) b function(int)
1006 Or if you need to disambiguate between tags, like:
1008 (gdb) b function[abi:other_tag](int)
1010 Tab completion was adjusted accordingly as well.
1014 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1015 gdb.new_thread are emitted. See the manual for further
1016 description of these.
1018 ** A new function, "gdb.rbreak" has been added to the Python API.
1019 This function allows the setting of a large number of breakpoints
1020 via a regex pattern in Python. See the manual for further details.
1022 ** Python breakpoints can now accept explicit locations. See the
1023 manual for a further description of this feature.
1026 * New features in the GDB remote stub, GDBserver
1028 ** GDBserver is now able to start inferior processes with a
1029 specified initial working directory.
1031 The user can set the desired working directory to be used from
1032 GDB using the new "set cwd" command.
1034 ** New "--selftest" command line option runs some GDBserver self
1035 tests. These self tests are disabled in releases.
1037 ** On Unix systems, GDBserver now does globbing expansion and variable
1038 substitution in inferior command line arguments.
1040 This is done by starting inferiors using a shell, like GDB does.
1041 See "set startup-with-shell" in the user manual for how to disable
1042 this from GDB when using "target extended-remote". When using
1043 "target remote", you can disable the startup with shell by using the
1044 new "--no-startup-with-shell" GDBserver command line option.
1046 ** On Unix systems, GDBserver now supports receiving environment
1047 variables that are to be set or unset from GDB. These variables
1048 will affect the environment to be passed to the inferior.
1050 * When catching an Ada exception raised with a message, GDB now prints
1051 the message in the catchpoint hit notification. In GDB/MI mode, that
1052 information is provided as an extra field named "exception-message"
1053 in the *stopped notification.
1055 * Trait objects can now be inspected When debugging Rust code. This
1056 requires compiler support which will appear in Rust 1.24.
1058 * New remote packets
1060 QEnvironmentHexEncoded
1061 Inform GDBserver of an environment variable that is to be passed to
1062 the inferior when starting it.
1065 Inform GDBserver of an environment variable that is to be unset
1066 before starting the remote inferior.
1069 Inform GDBserver that the environment should be reset (i.e.,
1070 user-set environment variables should be unset).
1073 Indicates whether the inferior must be started with a shell or not.
1076 Tell GDBserver that the inferior to be started should use a specific
1079 * The "maintenance print c-tdesc" command now takes an optional
1080 argument which is the file name of XML target description.
1082 * The "maintenance selftest" command now takes an optional argument to
1083 filter the tests to be run.
1085 * The "enable", and "disable" commands now accept a range of
1086 breakpoint locations, e.g. "enable 1.3-5".
1091 Set and show the current working directory for the inferior.
1093 set|show compile-gcc
1094 Set and show compilation command used for compiling and injecting code
1095 with the 'compile' commands.
1097 set debug separate-debug-file
1098 show debug separate-debug-file
1099 Control the display of debug output about separate debug file search.
1101 set dump-excluded-mappings
1102 show dump-excluded-mappings
1103 Control whether mappings marked with the VM_DONTDUMP flag should be
1104 dumped when generating a core file.
1106 maint info selftests
1107 List the registered selftests.
1110 Start the debugged program stopping at the first instruction.
1113 Control display of debugging messages related to OpenRISC targets.
1115 set|show print type nested-type-limit
1116 Set and show the limit of nesting level for nested types that the
1117 type printer will show.
1119 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1122 * Safer/improved support for debugging with no debug info
1124 GDB no longer assumes functions with no debug information return
1127 This means that GDB now refuses to call such functions unless you
1128 tell it the function's type, by either casting the call to the
1129 declared return type, or by casting the function to a function
1130 pointer of the right type, and calling that:
1132 (gdb) p getenv ("PATH")
1133 'getenv' has unknown return type; cast the call to its declared return type
1134 (gdb) p (char *) getenv ("PATH")
1135 $1 = 0x7fffffffe "/usr/local/bin:/"...
1136 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1137 $2 = 0x7fffffffe "/usr/local/bin:/"...
1139 Similarly, GDB no longer assumes that global variables with no debug
1140 info have type 'int', and refuses to print the variable's value
1141 unless you tell it the variable's type:
1144 'var' has unknown type; cast it to its declared type
1148 * New native configurations
1150 FreeBSD/aarch64 aarch64*-*-freebsd*
1151 FreeBSD/arm arm*-*-freebsd*
1155 FreeBSD/aarch64 aarch64*-*-freebsd*
1156 FreeBSD/arm arm*-*-freebsd*
1157 OpenRISC ELF or1k*-*-elf
1159 * Removed targets and native configurations
1161 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1163 *** Changes in GDB 8.0
1165 * GDB now supports access to the PKU register on GNU/Linux. The register is
1166 added by the Memory Protection Keys for Userspace feature which will be
1167 available in future Intel CPUs.
1169 * GDB now supports C++11 rvalue references.
1173 ** New functions to start, stop and access a running btrace recording.
1174 ** Rvalue references are now supported in gdb.Type.
1176 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1179 * Building GDB and GDBserver now requires a C++11 compiler.
1181 For example, GCC 4.8 or later.
1183 It is no longer possible to build GDB or GDBserver with a C
1184 compiler. The --disable-build-with-cxx configure option has been
1187 * Building GDB and GDBserver now requires GNU make >= 3.81.
1189 It is no longer supported to build GDB or GDBserver with another
1190 implementation of the make program or an earlier version of GNU make.
1192 * Native debugging on MS-Windows supports command-line redirection
1194 Command-line arguments used for starting programs on MS-Windows can
1195 now include redirection symbols supported by native Windows shells,
1196 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1197 as "run", "start", and "set args", as well as the corresponding MI
1200 * Support for thread names on MS-Windows.
1202 GDB now catches and handles the special exception that programs
1203 running on MS-Windows use to assign names to threads in the
1206 * Support for Java programs compiled with gcj has been removed.
1208 * User commands now accept an unlimited number of arguments.
1209 Previously, only up to 10 was accepted.
1211 * The "eval" command now expands user-defined command arguments.
1213 This makes it easier to process a variable number of arguments:
1218 eval "print $arg%d", $i
1223 * Target descriptions can now describe registers for sparc32 and sparc64.
1225 * GDB now supports DWARF version 5 (debug information format).
1226 Its .debug_names index is not yet supported.
1228 * New native configurations
1230 FreeBSD/mips mips*-*-freebsd
1234 Synopsys ARC arc*-*-elf32
1235 FreeBSD/mips mips*-*-freebsd
1237 * Removed targets and native configurations
1239 Alpha running FreeBSD alpha*-*-freebsd*
1240 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1245 Erases all the flash memory regions reported by the target.
1247 maint print arc arc-instruction address
1248 Print internal disassembler information about instruction at a given address.
1252 set disassembler-options
1253 show disassembler-options
1254 Controls the passing of target specific information to the disassembler.
1255 If it is necessary to specify more than one disassembler option then
1256 multiple options can be placed together into a comma separated list.
1257 The default value is the empty string. Currently, the only supported
1258 targets are ARM, PowerPC and S/390.
1263 Erases all the flash memory regions reported by the target. This is
1264 equivalent to the CLI command flash-erase.
1266 -file-list-shared-libraries
1267 List the shared libraries in the program. This is
1268 equivalent to the CLI command "info shared".
1271 Catchpoints stopping the program when Ada exceptions are
1272 handled. This is equivalent to the CLI command "catch handlers".
1274 *** Changes in GDB 7.12
1276 * GDB and GDBserver now build with a C++ compiler by default.
1278 The --enable-build-with-cxx configure option is now enabled by
1279 default. One must now explicitly configure with
1280 --disable-build-with-cxx in order to build with a C compiler. This
1281 option will be removed in a future release.
1283 * GDBserver now supports recording btrace without maintaining an active
1286 * GDB now supports a negative repeat count in the 'x' command to examine
1287 memory backward from the given address. For example:
1290 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1291 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1292 (gdb) x/-5i 0x0000000000400580
1293 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1294 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1295 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1296 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1297 0x40057b <main(int, char**)+25>:
1298 callq 0x400536 <Func1(int, char const*)>
1300 * Fortran: Support structures with fields of dynamic types and
1301 arrays of dynamic types.
1303 * The symbol dumping maintenance commands have new syntax.
1304 maint print symbols [-pc address] [--] [filename]
1305 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1306 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1307 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1308 maint print msymbols [-objfile objfile] [--] [filename]
1310 * GDB now supports multibit bitfields and enums in target register
1313 * New Python-based convenience function $_as_string(val), which returns
1314 the textual representation of a value. This function is especially
1315 useful to obtain the text label of an enum value.
1317 * Intel MPX bound violation handling.
1319 Segmentation faults caused by a Intel MPX boundary violation
1320 now display the kind of violation (upper or lower), the memory
1321 address accessed and the memory bounds, along with the usual
1322 signal received and code location.
1326 Program received signal SIGSEGV, Segmentation fault
1327 Upper bound violation while accessing address 0x7fffffffc3b3
1328 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1329 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1331 * Rust language support.
1332 GDB now supports debugging programs written in the Rust programming
1333 language. See https://www.rust-lang.org/ for more information about
1336 * Support for running interpreters on specified input/output devices
1338 GDB now supports a new mechanism that allows frontends to provide
1339 fully featured GDB console views, as a better alternative to
1340 building such views on top of the "-interpreter-exec console"
1341 command. See the new "new-ui" command below. With that command,
1342 frontends can now start GDB in the traditional command-line mode
1343 running in an embedded terminal emulator widget, and create a
1344 separate MI interpreter running on a specified i/o device. In this
1345 way, GDB handles line editing, history, tab completion, etc. in the
1346 console all by itself, and the GUI uses the separate MI interpreter
1347 for its own control and synchronization, invisible to the command
1350 * The "catch syscall" command catches groups of related syscalls.
1352 The "catch syscall" command now supports catching a group of related
1353 syscalls using the 'group:' or 'g:' prefix.
1358 skip -gfile file-glob-pattern
1359 skip -function function
1360 skip -rfunction regular-expression
1361 A generalized form of the skip command, with new support for
1362 glob-style file names and regular expressions for function names.
1363 Additionally, a file spec and a function spec may now be combined.
1365 maint info line-table REGEXP
1366 Display the contents of GDB's internal line table data struture.
1369 Run any GDB unit tests that were compiled in.
1372 Start a new user interface instance running INTERP as interpreter,
1373 using the TTY file for input/output.
1377 ** gdb.Breakpoint objects have a new attribute "pending", which
1378 indicates whether the breakpoint is pending.
1379 ** Three new breakpoint-related events have been added:
1380 gdb.breakpoint_created, gdb.breakpoint_modified, and
1381 gdb.breakpoint_deleted.
1383 signal-event EVENTID
1384 Signal ("set") the given MS-Windows event object. This is used in
1385 conjunction with the Windows JIT debugging (AeDebug) support, where
1386 the OS suspends a crashing process until a debugger can attach to
1387 it. Resuming the crashing process, in order to debug it, is done by
1388 signalling an event.
1390 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1391 was added in GDBserver, including JIT compiling fast tracepoint's
1392 conditional expression bytecode into native code.
1394 * Support for various remote target protocols and ROM monitors has
1397 target m32rsdi Remote M32R debugging over SDI
1398 target mips MIPS remote debugging protocol
1399 target pmon PMON ROM monitor
1400 target ddb NEC's DDB variant of PMON for Vr4300
1401 target rockhopper NEC RockHopper variant of PMON
1402 target lsi LSI variant of PMO
1404 * Support for tracepoints and fast tracepoints on powerpc-linux,
1405 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1406 including JIT compiling fast tracepoint's conditional expression
1407 bytecode into native code.
1409 * MI async record =record-started now includes the method and format used for
1410 recording. For example:
1412 =record-started,thread-group="i1",method="btrace",format="bts"
1414 * MI async record =thread-selected now includes the frame field. For example:
1416 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1420 Andes NDS32 nds32*-*-elf
1422 *** Changes in GDB 7.11
1424 * GDB now supports debugging kernel-based threads on FreeBSD.
1426 * Per-inferior thread numbers
1428 Thread numbers are now per inferior instead of global. If you're
1429 debugging multiple inferiors, GDB displays thread IDs using a
1430 qualified INF_NUM.THR_NUM form. For example:
1434 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1435 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1436 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1437 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1439 As consequence, thread numbers as visible in the $_thread
1440 convenience variable and in Python's InferiorThread.num attribute
1441 are no longer unique between inferiors.
1443 GDB now maintains a second thread ID per thread, referred to as the
1444 global thread ID, which is the new equivalent of thread numbers in
1445 previous releases. See also $_gthread below.
1447 For backwards compatibility, MI's thread IDs always refer to global
1450 * Commands that accept thread IDs now accept the qualified
1451 INF_NUM.THR_NUM form as well. For example:
1454 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1457 * In commands that accept a list of thread IDs, you can now refer to
1458 all threads of an inferior using a star wildcard. GDB accepts
1459 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1460 refer to all threads of the current inferior. For example, "info
1463 * You can use "info threads -gid" to display the global thread ID of
1466 * The new convenience variable $_gthread holds the global number of
1469 * The new convenience variable $_inferior holds the number of the
1472 * GDB now displays the ID and name of the thread that hit a breakpoint
1473 or received a signal, if your program is multi-threaded. For
1476 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1477 Thread 1 "main" received signal SIGINT, Interrupt.
1479 * Record btrace now supports non-stop mode.
1481 * Support for tracepoints on aarch64-linux was added in GDBserver.
1483 * The 'record instruction-history' command now indicates speculative execution
1484 when using the Intel Processor Trace recording format.
1486 * GDB now allows users to specify explicit locations, bypassing
1487 the linespec parser. This feature is also available to GDB/MI
1490 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1491 GDB now is able to debug both AArch64 applications and ARM applications
1494 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1495 including JIT compiling fast tracepoint's conditional expression bytecode
1498 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1500 * "info threads", "info inferiors", "info display", "info checkpoints"
1501 and "maint info program-spaces" now list the corresponding items in
1502 ascending ID order, for consistency with all other "info" commands.
1504 * In Ada, the overloads selection menu has been enhanced to display the
1505 parameter types and the return types for the matching overloaded subprograms.
1509 maint set target-non-stop (on|off|auto)
1510 maint show target-non-stop
1511 Control whether GDB targets always operate in non-stop mode even if
1512 "set non-stop" is "off". The default is "auto", meaning non-stop
1513 mode is enabled if supported by the target.
1515 maint set bfd-sharing
1516 maint show bfd-sharing
1517 Control the reuse of bfd objects.
1520 show debug bfd-cache
1521 Control display of debugging info regarding bfd caching.
1525 Control display of debugging info regarding FreeBSD threads.
1527 set remote multiprocess-extensions-packet
1528 show remote multiprocess-extensions-packet
1529 Set/show the use of the remote protocol multiprocess extensions.
1531 set remote thread-events
1532 show remote thread-events
1533 Set/show the use of thread create/exit events.
1535 set ada print-signatures on|off
1536 show ada print-signatures"
1537 Control whether parameter types and return types are displayed in overloads
1538 selection menus. It is activaled (@code{on}) by default.
1542 Controls the maximum size of memory, in bytes, that GDB will
1543 allocate for value contents. Prevents incorrect programs from
1544 causing GDB to allocate overly large buffers. Default is 64k.
1546 * The "disassemble" command accepts a new modifier: /s.
1547 It prints mixed source+disassembly like /m with two differences:
1548 - disassembled instructions are now printed in program order, and
1549 - and source for all relevant files is now printed.
1550 The "/m" option is now considered deprecated: its "source-centric"
1551 output hasn't proved useful in practice.
1553 * The "record instruction-history" command accepts a new modifier: /s.
1554 It behaves exactly like /m and prints mixed source+disassembly.
1556 * The "set scheduler-locking" command supports a new mode "replay".
1557 It behaves like "off" in record mode and like "on" in replay mode.
1559 * Support for various ROM monitors has been removed:
1561 target dbug dBUG ROM monitor for Motorola ColdFire
1562 target picobug Motorola picobug monitor
1563 target dink32 DINK32 ROM monitor for PowerPC
1564 target m32r Renesas M32R/D ROM monitor
1565 target mon2000 mon2000 ROM monitor
1566 target ppcbug PPCBUG ROM monitor for PowerPC
1568 * Support for reading/writing memory and extracting values on architectures
1569 whose memory is addressable in units of any integral multiple of 8 bits.
1572 Allows to break when an Ada exception is handled.
1574 * New remote packets
1577 Indicates that an exec system call was executed.
1579 exec-events feature in qSupported
1580 The qSupported packet allows GDB to request support for exec
1581 events using the new 'gdbfeature' exec-event, and the qSupported
1582 response can contain the corresponding 'stubfeature'. Set and
1583 show commands can be used to display whether these features are enabled.
1586 Equivalent to interrupting with the ^C character, but works in
1589 thread created stop reason (T05 create:...)
1590 Indicates that the thread was just created and is stopped at entry.
1592 thread exit stop reply (w exitcode;tid)
1593 Indicates that the thread has terminated.
1596 Enables/disables thread create and exit event reporting. For
1597 example, this is used in non-stop mode when GDB stops a set of
1598 threads and synchronously waits for the their corresponding stop
1599 replies. Without exit events, if one of the threads exits, GDB
1600 would hang forever not knowing that it should no longer expect a
1601 stop for that same thread.
1604 Indicates that there are no resumed threads left in the target (all
1605 threads are stopped). The remote stub reports support for this stop
1606 reply to GDB's qSupported query.
1609 Enables/disables catching syscalls from the inferior process.
1610 The remote stub reports support for this packet to GDB's qSupported query.
1612 syscall_entry stop reason
1613 Indicates that a syscall was just called.
1615 syscall_return stop reason
1616 Indicates that a syscall just returned.
1618 * Extended-remote exec events
1620 ** GDB now has support for exec events on extended-remote Linux targets.
1621 For such targets with Linux kernels 2.5.46 and later, this enables
1622 follow-exec-mode and exec catchpoints.
1624 set remote exec-event-feature-packet
1625 show remote exec-event-feature-packet
1626 Set/show the use of the remote exec event feature.
1628 * Thread names in remote protocol
1630 The reply to qXfer:threads:read may now include a name attribute for each
1633 * Target remote mode fork and exec events
1635 ** GDB now has support for fork and exec events on target remote mode
1636 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1637 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1638 fork and exec catchpoints.
1640 * Remote syscall events
1642 ** GDB now has support for catch syscall on remote Linux targets,
1643 currently enabled on x86/x86_64 architectures.
1645 set remote catch-syscall-packet
1646 show remote catch-syscall-packet
1647 Set/show the use of the remote catch syscall feature.
1651 ** The -var-set-format command now accepts the zero-hexadecimal
1652 format. It outputs data in hexadecimal format with zero-padding on the
1657 ** gdb.InferiorThread objects have a new attribute "global_num",
1658 which refers to the thread's global thread ID. The existing
1659 "num" attribute now refers to the thread's per-inferior number.
1660 See "Per-inferior thread numbers" above.
1661 ** gdb.InferiorThread objects have a new attribute "inferior", which
1662 is the Inferior object the thread belongs to.
1664 *** Changes in GDB 7.10
1666 * Support for process record-replay and reverse debugging on aarch64*-linux*
1667 targets has been added. GDB now supports recording of A64 instruction set
1668 including advance SIMD instructions.
1670 * Support for Sun's version of the "stabs" debug file format has been removed.
1672 * GDB now honors the content of the file /proc/PID/coredump_filter
1673 (PID is the process ID) on GNU/Linux systems. This file can be used
1674 to specify the types of memory mappings that will be included in a
1675 corefile. For more information, please refer to the manual page of
1676 "core(5)". GDB also has a new command: "set use-coredump-filter
1677 on|off". It allows to set whether GDB will read the content of the
1678 /proc/PID/coredump_filter file when generating a corefile.
1680 * The "info os" command on GNU/Linux can now display information on
1682 "info os cpus" Listing of all cpus/cores on the system
1684 * GDB has two new commands: "set serial parity odd|even|none" and
1685 "show serial parity". These allows to set or show parity for the
1688 * The "info source" command now displays the producer string if it was
1689 present in the debug info. This typically includes the compiler version
1690 and may include things like its command line arguments.
1692 * The "info dll", an alias of the "info sharedlibrary" command,
1693 is now available on all platforms.
1695 * Directory names supplied to the "set sysroot" commands may be
1696 prefixed with "target:" to tell GDB to access shared libraries from
1697 the target system, be it local or remote. This replaces the prefix
1698 "remote:". The default sysroot has been changed from "" to
1699 "target:". "remote:" is automatically converted to "target:" for
1700 backward compatibility.
1702 * The system root specified by "set sysroot" will be prepended to the
1703 filename of the main executable (if reported to GDB as absolute by
1704 the operating system) when starting processes remotely, and when
1705 attaching to already-running local or remote processes.
1707 * GDB now supports automatic location and retrieval of executable
1708 files from remote targets. Remote debugging can now be initiated
1709 using only a "target remote" or "target extended-remote" command
1710 (no "set sysroot" or "file" commands are required). See "New remote
1713 * The "dump" command now supports verilog hex format.
1715 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1717 * On GNU/Linux, GDB and gdbserver are now able to access executable
1718 and shared library files without a "set sysroot" command when
1719 attaching to processes running in different mount namespaces from
1720 the debugger. This makes it possible to attach to processes in
1721 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1722 See "New remote packets" below.
1724 * The "tui reg" command now provides completion for all of the
1725 available register groups, including target specific groups.
1727 * The HISTSIZE environment variable is no longer read when determining
1728 the size of GDB's command history. GDB now instead reads the dedicated
1729 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1730 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1735 ** Memory ports can now be unbuffered.
1739 ** gdb.Objfile objects have a new attribute "username",
1740 which is the name of the objfile as specified by the user,
1741 without, for example, resolving symlinks.
1742 ** You can now write frame unwinders in Python.
1743 ** gdb.Type objects have a new method "optimized_out",
1744 returning optimized out gdb.Value instance of this type.
1745 ** gdb.Value objects have new methods "reference_value" and
1746 "const_value" which return a reference to the value and a
1747 "const" version of the value respectively.
1751 maint print symbol-cache
1752 Print the contents of the symbol cache.
1754 maint print symbol-cache-statistics
1755 Print statistics of symbol cache usage.
1757 maint flush-symbol-cache
1758 Flush the contents of the symbol cache.
1762 Start branch trace recording using Branch Trace Store (BTS) format.
1765 Evaluate expression by using the compiler and print result.
1769 Explicit commands for enabling and disabling tui mode.
1772 set mpx bound on i386 and amd64
1773 Support for bound table investigation on Intel MPX enabled applications.
1777 Start branch trace recording using Intel Processor Trace format.
1780 Print information about branch tracing internals.
1782 maint btrace packet-history
1783 Print the raw branch tracing data.
1785 maint btrace clear-packet-history
1786 Discard the stored raw branch tracing data.
1789 Discard all branch tracing data. It will be fetched and processed
1790 anew by the next "record" command.
1795 Renamed from "set debug dwarf2-die".
1796 show debug dwarf-die
1797 Renamed from "show debug dwarf2-die".
1799 set debug dwarf-read
1800 Renamed from "set debug dwarf2-read".
1801 show debug dwarf-read
1802 Renamed from "show debug dwarf2-read".
1804 maint set dwarf always-disassemble
1805 Renamed from "maint set dwarf2 always-disassemble".
1806 maint show dwarf always-disassemble
1807 Renamed from "maint show dwarf2 always-disassemble".
1809 maint set dwarf max-cache-age
1810 Renamed from "maint set dwarf2 max-cache-age".
1811 maint show dwarf max-cache-age
1812 Renamed from "maint show dwarf2 max-cache-age".
1814 set debug dwarf-line
1815 show debug dwarf-line
1816 Control display of debugging info regarding DWARF line processing.
1819 show max-completions
1820 Set the maximum number of candidates to be considered during
1821 completion. The default value is 200. This limit allows GDB
1822 to avoid generating large completion lists, the computation of
1823 which can cause the debugger to become temporarily unresponsive.
1825 set history remove-duplicates
1826 show history remove-duplicates
1827 Control the removal of duplicate history entries.
1829 maint set symbol-cache-size
1830 maint show symbol-cache-size
1831 Control the size of the symbol cache.
1833 set|show record btrace bts buffer-size
1834 Set and show the size of the ring buffer used for branch tracing in
1836 The obtained size may differ from the requested size. Use "info
1837 record" to see the obtained buffer size.
1839 set debug linux-namespaces
1840 show debug linux-namespaces
1841 Control display of debugging info regarding Linux namespaces.
1843 set|show record btrace pt buffer-size
1844 Set and show the size of the ring buffer used for branch tracing in
1845 Intel Processor Trace format.
1846 The obtained size may differ from the requested size. Use "info
1847 record" to see the obtained buffer size.
1849 maint set|show btrace pt skip-pad
1850 Set and show whether PAD packets are skipped when computing the
1853 * The command 'thread apply all' can now support new option '-ascending'
1854 to call its specified command for all threads in ascending order.
1856 * Python/Guile scripting
1858 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1859 special section named `.debug_gdb_scripts'.
1861 * New remote packets
1863 qXfer:btrace-conf:read
1864 Return the branch trace configuration for the current thread.
1866 Qbtrace-conf:bts:size
1867 Set the requested ring buffer size for branch tracing in BTS format.
1870 Enable Intel Procesor Trace-based branch tracing for the current
1871 process. The remote stub reports support for this packet to GDB's
1874 Qbtrace-conf:pt:size
1875 Set the requested ring buffer size for branch tracing in Intel Processor
1879 Indicates a memory breakpoint instruction was executed, irrespective
1880 of whether it was GDB that planted the breakpoint or the breakpoint
1881 is hardcoded in the program. This is required for correct non-stop
1885 Indicates the target stopped for a hardware breakpoint. This is
1886 required for correct non-stop mode operation.
1889 Return information about files on the remote system.
1891 qXfer:exec-file:read
1892 Return the full absolute name of the file that was executed to
1893 create a process running on the remote system.
1896 Select the filesystem on which vFile: operations with filename
1897 arguments will operate. This is required for GDB to be able to
1898 access files on remote targets where the remote stub does not
1899 share a common filesystem with the inferior(s).
1902 Indicates that a fork system call was executed.
1905 Indicates that a vfork system call was executed.
1907 vforkdone stop reason
1908 Indicates that a vfork child of the specified process has executed
1909 an exec or exit, allowing the vfork parent to resume execution.
1911 fork-events and vfork-events features in qSupported
1912 The qSupported packet allows GDB to request support for fork and
1913 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1914 and the qSupported response can contain the corresponding
1915 'stubfeatures'. Set and show commands can be used to display
1916 whether these features are enabled.
1918 * Extended-remote fork events
1920 ** GDB now has support for fork events on extended-remote Linux
1921 targets. For targets with Linux kernels 2.5.60 and later, this
1922 enables follow-fork-mode and detach-on-fork for both fork and
1923 vfork, as well as fork and vfork catchpoints.
1925 * The info record command now shows the recording format and the
1926 branch tracing configuration for the current thread when using
1927 the btrace record target.
1928 For the BTS format, it shows the ring buffer size.
1930 * GDB now has support for DTrace USDT (Userland Static Defined
1931 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1933 * GDB now supports access to vector registers on S/390 GNU/Linux
1936 * Removed command line options
1938 -xdb HP-UX XDB compatibility mode.
1940 * Removed targets and native configurations
1942 HP/PA running HP-UX hppa*-*-hpux*
1943 Itanium running HP-UX ia64-*-hpux*
1945 * New configure options
1948 This configure option allows the user to build GDB with support for
1949 Intel Processor Trace (default: auto). This requires libipt.
1951 --with-libipt-prefix=PATH
1952 Specify the path to the version of libipt that GDB should use.
1953 $PATH/include should contain the intel-pt.h header and
1954 $PATH/lib should contain the libipt.so library.
1956 *** Changes in GDB 7.9.1
1960 ** Xmethods can now specify a result type.
1962 *** Changes in GDB 7.9
1964 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1968 ** You can now access frame registers from Python scripts.
1969 ** New attribute 'producer' for gdb.Symtab objects.
1970 ** gdb.Objfile objects have a new attribute "progspace",
1971 which is the gdb.Progspace object of the containing program space.
1972 ** gdb.Objfile objects have a new attribute "owner".
1973 ** gdb.Objfile objects have a new attribute "build_id",
1974 which is the build ID generated when the file was built.
1975 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1976 ** A new event "gdb.clear_objfiles" has been added, triggered when
1977 selecting a new file to debug.
1978 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1979 ** New function gdb.lookup_objfile.
1981 New events which are triggered when GDB modifies the state of the
1984 ** gdb.events.inferior_call_pre: Function call is about to be made.
1985 ** gdb.events.inferior_call_post: Function call has just been made.
1986 ** gdb.events.memory_changed: A memory location has been altered.
1987 ** gdb.events.register_changed: A register has been altered.
1989 * New Python-based convenience functions:
1991 ** $_caller_is(name [, number_of_frames])
1992 ** $_caller_matches(regexp [, number_of_frames])
1993 ** $_any_caller_is(name [, number_of_frames])
1994 ** $_any_caller_matches(regexp [, number_of_frames])
1996 * GDB now supports the compilation and injection of source code into
1997 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1998 to compile the source code to object code, and if successful, inject
1999 and execute that code within the current context of the inferior.
2000 Currently the C language is supported. The commands used to
2001 interface with this new feature are:
2003 compile code [-raw|-r] [--] [source code]
2004 compile file [-raw|-r] filename
2008 demangle [-l language] [--] name
2009 Demangle "name" in the specified language, or the current language
2010 if elided. This command is renamed from the "maint demangle" command.
2011 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2012 as "maint demangler-warning".
2014 queue-signal signal-name-or-number
2015 Queue a signal to be delivered to the thread when it is resumed.
2017 add-auto-load-scripts-directory directory
2018 Add entries to the list of directories from which to load auto-loaded
2021 maint print user-registers
2022 List all currently available "user" registers.
2024 compile code [-r|-raw] [--] [source code]
2025 Compile, inject, and execute in the inferior the executable object
2026 code produced by compiling the provided source code.
2028 compile file [-r|-raw] filename
2029 Compile and inject into the inferior the executable object code
2030 produced by compiling the source code stored in the filename
2033 * On resume, GDB now always passes the signal the program had stopped
2034 for to the thread the signal was sent to, even if the user changed
2035 threads before resuming. Previously GDB would often (but not
2036 always) deliver the signal to the thread that happens to be current
2039 * Conversely, the "signal" command now consistently delivers the
2040 requested signal to the current thread. GDB now asks for
2041 confirmation if the program had stopped for a signal and the user
2042 switched threads meanwhile.
2044 * "breakpoint always-inserted" modes "off" and "auto" merged.
2046 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2047 won't remove breakpoints from the target until all threads stop,
2048 even in non-stop mode. The "auto" mode has been removed, and "off"
2049 is now the default mode.
2053 set debug symbol-lookup
2054 show debug symbol-lookup
2055 Control display of debugging info regarding symbol lookup.
2059 ** The -list-thread-groups command outputs an exit-code field for
2060 inferiors that have exited.
2064 MIPS SDE mips*-sde*-elf*
2068 Support for these obsolete configurations has been removed.
2070 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2071 SGI Irix-5.x mips-*-irix5*
2072 SGI Irix-6.x mips-*-irix6*
2073 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2074 VAX running Ultrix vax-*-ultrix*
2076 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2077 and "assf"), have been removed. Use the "sharedlibrary" command, or
2078 its alias "share", instead.
2080 *** Changes in GDB 7.8
2082 * New command line options
2085 This is an alias for the --data-directory option.
2087 * GDB supports printing and modifying of variable length automatic arrays
2088 as specified in ISO C99.
2090 * The ARM simulator now supports instruction level tracing
2091 with or without disassembly.
2095 GDB now has support for scripting using Guile. Whether this is
2096 available is determined at configure time.
2097 Guile version 2.0 or greater is required.
2098 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2100 * New commands (for set/show, see "New options" below)
2104 Invoke CODE by passing it to the Guile interpreter.
2108 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2110 info auto-load guile-scripts [regexp]
2111 Print the list of automatically loaded Guile scripts.
2113 * The source command is now capable of sourcing Guile scripts.
2114 This feature is dependent on the debugger being built with Guile support.
2118 set print symbol-loading (off|brief|full)
2119 show print symbol-loading
2120 Control whether to print informational messages when loading symbol
2121 information for a file. The default is "full", but when debugging
2122 programs with large numbers of shared libraries the amount of output
2123 becomes less useful.
2125 set guile print-stack (none|message|full)
2126 show guile print-stack
2127 Show a stack trace when an error is encountered in a Guile script.
2129 set auto-load guile-scripts (on|off)
2130 show auto-load guile-scripts
2131 Control auto-loading of Guile script files.
2133 maint ada set ignore-descriptive-types (on|off)
2134 maint ada show ignore-descriptive-types
2135 Control whether the debugger should ignore descriptive types in Ada
2136 programs. The default is not to ignore the descriptive types. See
2137 the user manual for more details on descriptive types and the intended
2138 usage of this option.
2140 set auto-connect-native-target
2142 Control whether GDB is allowed to automatically connect to the
2143 native target for the run, attach, etc. commands when not connected
2144 to any target yet. See also "target native" below.
2146 set record btrace replay-memory-access (read-only|read-write)
2147 show record btrace replay-memory-access
2148 Control what memory accesses are allowed during replay.
2150 maint set target-async (on|off)
2151 maint show target-async
2152 This controls whether GDB targets operate in synchronous or
2153 asynchronous mode. Normally the default is asynchronous, if it is
2154 available; but this can be changed to more easily debug problems
2155 occurring only in synchronous mode.
2157 set mi-async (on|off)
2159 Control whether MI asynchronous mode is preferred. This supersedes
2160 "set target-async" of previous GDB versions.
2162 * "set target-async" is deprecated as a CLI option and is now an alias
2163 for "set mi-async" (only puts MI into async mode).
2165 * Background execution commands (e.g., "c&", "s&", etc.) are now
2166 possible ``out of the box'' if the target supports them. Previously
2167 the user would need to explicitly enable the possibility with the
2168 "set target-async on" command.
2170 * New features in the GDB remote stub, GDBserver
2172 ** New option --debug-format=option1[,option2,...] allows one to add
2173 additional text to each output. At present only timestamps
2174 are supported: --debug-format=timestamps.
2175 Timestamps can also be turned on with the
2176 "monitor set debug-format timestamps" command from GDB.
2178 * The 'record instruction-history' command now starts counting instructions
2179 at one. This also affects the instruction ranges reported by the
2180 'record function-call-history' command when given the /i modifier.
2182 * The command 'record function-call-history' supports a new modifier '/c' to
2183 indent the function names based on their call stack depth.
2184 The fields for the '/i' and '/l' modifier have been reordered.
2185 The source line range is now prefixed with 'at'.
2186 The instruction range is now prefixed with 'inst'.
2187 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2188 "record instruction-history" and "list" commands.
2190 * The ranges given as arguments to the 'record function-call-history' and
2191 'record instruction-history' commands are now inclusive.
2193 * The btrace record target now supports the 'record goto' command.
2194 For locations inside the execution trace, the back trace is computed
2195 based on the information stored in the execution trace.
2197 * The btrace record target supports limited reverse execution and replay.
2198 The target does not record data and therefore does not allow reading
2199 memory or registers.
2201 * The "catch syscall" command now works on s390*-linux* targets.
2203 * The "compare-sections" command is no longer specific to target
2204 remote. It now works with all targets.
2206 * All native targets are now consistently called "native".
2207 Consequently, the "target child", "target GNU", "target djgpp",
2208 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2209 commands have been replaced with "target native". The QNX/NTO port
2210 leaves the "procfs" target in place and adds a "native" target for
2211 consistency with other ports. The impact on users should be minimal
2212 as these commands previously either throwed an error, or were
2213 no-ops. The target's name is visible in the output of the following
2214 commands: "help target", "info target", "info files", "maint print
2217 * The "target native" command now connects to the native target. This
2218 can be used to launch native programs even when "set
2219 auto-connect-native-target" is set to off.
2221 * GDB now supports access to Intel MPX registers on GNU/Linux.
2223 * Support for Intel AVX-512 registers on GNU/Linux.
2224 Support displaying and modifying Intel AVX-512 registers
2225 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2227 * New remote packets
2229 qXfer:btrace:read's annex
2230 The qXfer:btrace:read packet supports a new annex 'delta' to read
2231 branch trace incrementally.
2235 ** Valid Python operations on gdb.Value objects representing
2236 structs/classes invoke the corresponding overloaded operators if
2238 ** New `Xmethods' feature in the Python API. Xmethods are
2239 additional methods or replacements for existing methods of a C++
2240 class. This feature is useful for those cases where a method
2241 defined in C++ source code could be inlined or optimized out by
2242 the compiler, making it unavailable to GDB.
2245 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2247 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2248 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2249 its alias "share", instead.
2251 * The commands "set remotebaud" and "show remotebaud" are no longer
2252 supported. Use "set serial baud" and "show serial baud" (respectively)
2257 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2258 target-async". The latter is left as a deprecated alias of the
2259 former for backward compatibility. If the target supports it,
2260 CLI background execution commands are now always possible by
2261 default, independently of whether the frontend stated a
2262 preference for asynchronous execution with "-gdb-set mi-async".
2263 Previously "-gdb-set target-async off" affected both MI execution
2264 commands and CLI execution commands.
2266 *** Changes in GDB 7.7
2268 * Improved support for process record-replay and reverse debugging on
2269 arm*-linux* targets. Support for thumb32 and syscall instruction
2270 recording has been added.
2272 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2274 * GDB now supports Fission DWP file format version 2.
2275 http://gcc.gnu.org/wiki/DebugFission
2277 * New convenience function "$_isvoid", to check whether an expression
2278 is void. A void expression is an expression where the type of the
2279 result is "void". For example, some convenience variables may be
2280 "void" when evaluated (e.g., "$_exitcode" before the execution of
2281 the program being debugged; or an undefined convenience variable).
2282 Another example, when calling a function whose return type is
2285 * The "maintenance print objfiles" command now takes an optional regexp.
2287 * The "catch syscall" command now works on arm*-linux* targets.
2289 * GDB now consistently shows "<not saved>" when printing values of
2290 registers the debug info indicates have not been saved in the frame
2291 and there's nowhere to retrieve them from
2292 (callee-saved/call-clobbered registers):
2297 (gdb) info registers rax
2300 Before, the former would print "<optimized out>", and the latter
2301 "*value not available*".
2303 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2308 ** Frame filters and frame decorators have been added.
2309 ** Temporary breakpoints are now supported.
2310 ** Line tables representation has been added.
2311 ** New attribute 'parent_type' for gdb.Field objects.
2312 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2313 ** New attribute 'name' for gdb.Type objects.
2317 Nios II ELF nios2*-*-elf
2318 Nios II GNU/Linux nios2*-*-linux
2319 Texas Instruments MSP430 msp430*-*-elf
2321 * Removed native configurations
2323 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2324 been removed. ELF variants of these configurations are kept supported.
2326 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2327 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2328 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2329 i[34567]86-*-openbsd3.[0-3]
2330 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2331 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2332 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2336 Like "catch throw", but catches a re-thrown exception.
2337 maint check-psymtabs
2338 Renamed from old "maint check-symtabs".
2340 Perform consistency checks on symtabs.
2341 maint expand-symtabs
2342 Expand symtabs matching an optional regexp.
2345 Display the details of GDB configure-time options.
2347 maint set|show per-command
2348 maint set|show per-command space
2349 maint set|show per-command time
2350 maint set|show per-command symtab
2351 Enable display of per-command gdb resource usage.
2353 remove-symbol-file FILENAME
2354 remove-symbol-file -a ADDRESS
2355 Remove a symbol file added via add-symbol-file. The file to remove
2356 can be identified by its filename or by an address that lies within
2357 the boundaries of this symbol file in memory.
2360 info exceptions REGEXP
2361 Display the list of Ada exceptions defined in the program being
2362 debugged. If provided, only the exceptions whose names match REGEXP
2367 set debug symfile off|on
2369 Control display of debugging info regarding reading symbol files and
2370 symbol tables within those files
2372 set print raw frame-arguments
2373 show print raw frame-arguments
2374 Set/show whether to print frame arguments in raw mode,
2375 disregarding any defined pretty-printers.
2377 set remote trace-status-packet
2378 show remote trace-status-packet
2379 Set/show the use of remote protocol qTStatus packet.
2383 Control display of debugging messages related to Nios II targets.
2387 Control whether target-assisted range stepping is enabled.
2389 set startup-with-shell
2390 show startup-with-shell
2391 Specifies whether Unix child processes are started via a shell or
2396 Use the target memory cache for accesses to the code segment. This
2397 improves performance of remote debugging (particularly disassembly).
2399 * You can now use a literal value 'unlimited' for options that
2400 interpret 0 or -1 as meaning "unlimited". E.g., "set
2401 trace-buffer-size unlimited" is now an alias for "set
2402 trace-buffer-size -1" and "set height unlimited" is now an alias for
2405 * The "set debug symtab-create" debugging option of GDB has been changed to
2406 accept a verbosity level. 0 means "off", 1 provides basic debugging
2407 output, and values of 2 or greater provides more verbose output.
2409 * New command-line options
2411 Display the details of GDB configure-time options.
2413 * The command 'tsave' can now support new option '-ctf' to save trace
2414 buffer in Common Trace Format.
2416 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2419 * GDB now implements the the C++ 'typeid' operator.
2421 * The new convenience variable $_exception holds the exception being
2422 thrown or caught at an exception-related catchpoint.
2424 * The exception-related catchpoints, like "catch throw", now accept a
2425 regular expression which can be used to filter exceptions by type.
2427 * The new convenience variable $_exitsignal is automatically set to
2428 the terminating signal number when the program being debugged dies
2429 due to an uncaught signal.
2433 ** All MI commands now accept an optional "--language" option.
2434 Support for this feature can be verified by using the "-list-features"
2435 command, which should contain "language-option".
2437 ** The new command -info-gdb-mi-command allows the user to determine
2438 whether a GDB/MI command is supported or not.
2440 ** The "^error" result record returned when trying to execute an undefined
2441 GDB/MI command now provides a variable named "code" whose content is the
2442 "undefined-command" error code. Support for this feature can be verified
2443 by using the "-list-features" command, which should contain
2444 "undefined-command-error-code".
2446 ** The -trace-save MI command can optionally save trace buffer in Common
2449 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2451 ** The command -data-list-register-values now accepts an optional
2452 "--skip-unavailable" option. When used, only the available registers
2455 ** The new command -trace-frame-collected dumps collected variables,
2456 computed expressions, tvars, memory and registers in a traceframe.
2458 ** The commands -stack-list-locals, -stack-list-arguments and
2459 -stack-list-variables now accept an option "--skip-unavailable".
2460 When used, only the available locals or arguments are displayed.
2462 ** The -exec-run command now accepts an optional "--start" option.
2463 When used, the command follows the same semantics as the "start"
2464 command, stopping the program's execution at the start of its
2465 main subprogram. Support for this feature can be verified using
2466 the "-list-features" command, which should contain
2467 "exec-run-start-option".
2469 ** The new commands -catch-assert and -catch-exceptions insert
2470 catchpoints stopping the program when Ada exceptions are raised.
2472 ** The new command -info-ada-exceptions provides the equivalent of
2473 the new "info exceptions" command.
2475 * New system-wide configuration scripts
2476 A GDB installation now provides scripts suitable for use as system-wide
2477 configuration scripts for the following systems:
2481 * GDB now supports target-assigned range stepping with remote targets.
2482 This improves the performance of stepping source lines by reducing
2483 the number of control packets from/to GDB. See "New remote packets"
2486 * GDB now understands the element 'tvar' in the XML traceframe info.
2487 It has the id of the collected trace state variables.
2489 * On S/390 targets that provide the transactional-execution feature,
2490 the program interruption transaction diagnostic block (TDB) is now
2491 represented as a number of additional "registers" in GDB.
2493 * New remote packets
2497 The vCont packet supports a new 'r' action, that tells the remote
2498 stub to step through an address range itself, without GDB
2499 involvemement at each single-step.
2501 qXfer:libraries-svr4:read's annex
2502 The previously unused annex of the qXfer:libraries-svr4:read packet
2503 is now used to support passing an argument list. The remote stub
2504 reports support for this argument list to GDB's qSupported query.
2505 The defined arguments are "start" and "prev", used to reduce work
2506 necessary for library list updating, resulting in significant
2509 * New features in the GDB remote stub, GDBserver
2511 ** GDBserver now supports target-assisted range stepping. Currently
2512 enabled on x86/x86_64 GNU/Linux targets.
2514 ** GDBserver now adds element 'tvar' in the XML in the reply to
2515 'qXfer:traceframe-info:read'. It has the id of the collected
2516 trace state variables.
2518 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2521 * New 'z' formatter for printing and examining memory, this displays the
2522 value as hexadecimal zero padded on the left to the size of the type.
2524 * GDB can now use Windows x64 unwinding data.
2526 * The "set remotebaud" command has been replaced by "set serial baud".
2527 Similarly, "show remotebaud" has been replaced by "show serial baud".
2528 The "set remotebaud" and "show remotebaud" commands are still available
2529 to provide backward compatibility with older versions of GDB.
2531 *** Changes in GDB 7.6
2533 * Target record has been renamed to record-full.
2534 Record/replay is now enabled with the "record full" command.
2535 This also affects settings that are associated with full record/replay
2536 that have been moved from "set/show record" to "set/show record full":
2538 set|show record full insn-number-max
2539 set|show record full stop-at-limit
2540 set|show record full memory-query
2542 * A new record target "record-btrace" has been added. The new target
2543 uses hardware support to record the control-flow of a process. It
2544 does not support replaying the execution, but it implements the
2545 below new commands for investigating the recorded execution log.
2546 This new recording method can be enabled using:
2550 The "record-btrace" target is only available on Intel Atom processors
2551 and requires a Linux kernel 2.6.32 or later.
2553 * Two new commands have been added for record/replay to give information
2554 about the recorded execution without having to replay the execution.
2555 The commands are only supported by "record btrace".
2557 record instruction-history prints the execution history at
2558 instruction granularity
2560 record function-call-history prints the execution history at
2561 function granularity
2563 * New native configurations
2565 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2566 FreeBSD/powerpc powerpc*-*-freebsd
2567 x86_64/Cygwin x86_64-*-cygwin*
2568 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2572 ARM AArch64 aarch64*-*-elf
2573 ARM AArch64 GNU/Linux aarch64*-*-linux
2574 Lynx 178 PowerPC powerpc-*-lynx*178
2575 x86_64/Cygwin x86_64-*-cygwin*
2576 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2578 * If the configured location of system.gdbinit file (as given by the
2579 --with-system-gdbinit option at configure time) is in the
2580 data-directory (as specified by --with-gdb-datadir at configure
2581 time) or in one of its subdirectories, then GDB will look for the
2582 system-wide init file in the directory specified by the
2583 --data-directory command-line option.
2585 * New command line options:
2587 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2588 other initialization files, unlike -nx which disables all of them.
2590 * Removed command line options
2592 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2595 * The 'ptype' and 'whatis' commands now accept an argument to control
2598 * 'info proc' now works on some core files.
2602 ** Vectors can be created with gdb.Type.vector.
2604 ** Python's atexit.register now works in GDB.
2606 ** Types can be pretty-printed via a Python API.
2608 ** Python 3 is now supported (in addition to Python 2.4 or later)
2610 ** New class gdb.Architecture exposes GDB's internal representation
2611 of architecture in the Python API.
2613 ** New method Frame.architecture returns the gdb.Architecture object
2614 corresponding to the frame's architecture.
2616 * New Python-based convenience functions:
2618 ** $_memeq(buf1, buf2, length)
2619 ** $_streq(str1, str2)
2621 ** $_regex(str, regex)
2623 * The 'cd' command now defaults to using '~' (the home directory) if not
2626 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2627 default for GCC since November 2000.
2629 * The command 'forward-search' can now be abbreviated as 'fo'.
2631 * The command 'info tracepoints' can now display 'installed on target'
2632 or 'not installed on target' for each non-pending location of tracepoint.
2634 * New configure options
2636 --enable-libmcheck/--disable-libmcheck
2637 By default, development versions are built with -lmcheck on hosts
2638 that support it, in order to help track memory corruption issues.
2639 Release versions, on the other hand, are built without -lmcheck
2640 by default. The --enable-libmcheck/--disable-libmcheck configure
2641 options allow the user to override that default.
2642 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2643 This configure option allows the user to build GDB with
2644 libbabeltrace using which GDB can read Common Trace Format data.
2646 * New commands (for set/show, see "New options" below)
2649 Catch signals. This is similar to "handle", but allows commands and
2650 conditions to be attached.
2653 List the BFDs known to GDB.
2655 python-interactive [command]
2657 Start a Python interactive prompt, or evaluate the optional command
2658 and print the result of expressions.
2661 "py" is a new alias for "python".
2663 enable type-printer [name]...
2664 disable type-printer [name]...
2665 Enable or disable type printers.
2669 ** For the Renesas Super-H architecture, the "regs" command has been removed
2670 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2675 set print type methods (on|off)
2676 show print type methods
2677 Control whether method declarations are displayed by "ptype".
2678 The default is to show them.
2680 set print type typedefs (on|off)
2681 show print type typedefs
2682 Control whether typedef definitions are displayed by "ptype".
2683 The default is to show them.
2685 set filename-display basename|relative|absolute
2686 show filename-display
2687 Control the way in which filenames is displayed.
2688 The default is "relative", which preserves previous behavior.
2690 set trace-buffer-size
2691 show trace-buffer-size
2692 Request target to change the size of trace buffer.
2694 set remote trace-buffer-size-packet auto|on|off
2695 show remote trace-buffer-size-packet
2696 Control the use of the remote protocol `QTBuffer:size' packet.
2700 Control display of debugging messages related to ARM AArch64.
2703 set debug coff-pe-read
2704 show debug coff-pe-read
2705 Control display of debugging messages related to reading of COFF/PE
2710 Control display of debugging messages related to Mach-O symbols
2713 set debug notification
2714 show debug notification
2715 Control display of debugging info for async remote notification.
2719 ** Command parameter changes are now notified using new async record
2720 "=cmd-param-changed".
2721 ** Trace frame changes caused by command "tfind" are now notified using
2722 new async record "=traceframe-changed".
2723 ** The creation, deletion and modification of trace state variables
2724 are now notified using new async records "=tsv-created",
2725 "=tsv-deleted" and "=tsv-modified".
2726 ** The start and stop of process record are now notified using new
2727 async record "=record-started" and "=record-stopped".
2728 ** Memory changes are now notified using new async record
2730 ** The data-disassemble command response will include a "fullname" field
2731 containing the absolute file name when source has been requested.
2732 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2733 command, to allow pattern filling of memory areas.
2734 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2735 library load/unload events.
2736 ** The response to breakpoint commands and breakpoint async records
2737 includes an "installed" field containing a boolean state about each
2738 non-pending tracepoint location is whether installed on target or not.
2739 ** Output of the "-trace-status" command includes a "trace-file" field
2740 containing the name of the trace file being examined. This field is
2741 optional, and only present when examining a trace file.
2742 ** The "fullname" field is now always present along with the "file" field,
2743 even if the file cannot be found by GDB.
2745 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2746 You must have the LZMA library available when configuring GDB for this
2747 feature to be enabled. For more information, see:
2748 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2750 * New remote packets
2753 Set the size of trace buffer. The remote stub reports support for this
2754 packet to gdb's qSupported query.
2757 Enable Branch Trace Store (BTS)-based branch tracing for the current
2758 thread. The remote stub reports support for this packet to gdb's
2762 Disable branch tracing for the current thread. The remote stub reports
2763 support for this packet to gdb's qSupported query.
2766 Read the traced branches for the current thread. The remote stub
2767 reports support for this packet to gdb's qSupported query.
2769 *** Changes in GDB 7.5
2771 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2772 for more x32 ABI info.
2774 * GDB now supports access to MIPS DSP registers on Linux targets.
2776 * GDB now supports debugging microMIPS binaries.
2778 * The "info os" command on GNU/Linux can now display information on
2779 several new classes of objects managed by the operating system:
2780 "info os procgroups" lists process groups
2781 "info os files" lists file descriptors
2782 "info os sockets" lists internet-domain sockets
2783 "info os shm" lists shared-memory regions
2784 "info os semaphores" lists semaphores
2785 "info os msg" lists message queues
2786 "info os modules" lists loaded kernel modules
2788 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2789 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2790 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2791 options and inspect the probe arguments using the new $_probe_arg family
2792 of convenience variables. You can obtain more information about SystemTap
2793 in <http://sourceware.org/systemtap/>.
2795 * GDB now supports reversible debugging on ARM, it allows you to
2796 debug basic ARM and THUMB instructions, and provides
2797 record/replay support.
2799 * The option "symbol-reloading" has been deleted as it is no longer used.
2803 ** GDB commands implemented in Python can now be put in command class
2806 ** The "maint set python print-stack on|off" is now deleted.
2808 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2809 apply "flag enum"-style pretty-printing to any enum.
2811 ** gdb.lookup_symbol can now work when there is no current frame.
2813 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2814 the source at which the symbol was defined.
2816 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2817 method 'value'. The former indicates whether the symbol needs a
2818 frame in order to compute its value, and the latter computes the
2821 ** A new method 'referenced_value' on gdb.Value objects which can
2822 dereference pointer as well as C++ reference values.
2824 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2825 which return the global and static blocks (as gdb.Block objects),
2826 of the underlying symbol table, respectively.
2828 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2829 object associated with a PC value.
2831 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2832 of the address range occupied by code for the current source line.
2834 * Go language support.
2835 GDB now supports debugging programs written in the Go programming
2838 * GDBserver now supports stdio connections.
2839 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2841 * The binary "gdbtui" can no longer be built or installed.
2842 Use "gdb -tui" instead.
2844 * GDB will now print "flag" enums specially. A flag enum is one where
2845 all the enumerator values have no bits in common when pairwise
2846 "and"ed. When printing a value whose type is a flag enum, GDB will
2847 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2848 (gdb) print (enum E) 3
2851 * The filename part of a linespec will now match trailing components
2852 of a source file name. For example, "break gcc/expr.c:1000" will
2853 now set a breakpoint in build/gcc/expr.c, but not
2854 build/libcpp/expr.c.
2856 * The "info proc" and "generate-core-file" commands will now also
2857 work on remote targets connected to GDBserver on Linux.
2859 * The command "info catch" has been removed. It has been disabled
2860 since December 2007.
2862 * The "catch exception" and "catch assert" commands now accept
2863 a condition at the end of the command, much like the "break"
2864 command does. For instance:
2866 (gdb) catch exception Constraint_Error if Barrier = True
2868 Previously, it was possible to add a condition to such catchpoints,
2869 but it had to be done as a second step, after the catchpoint had been
2870 created, using the "condition" command.
2872 * The "info static-tracepoint-marker" command will now also work on
2873 native Linux targets with in-process agent.
2875 * GDB can now set breakpoints on inlined functions.
2877 * The .gdb_index section has been updated to include symbols for
2878 inlined functions. GDB will ignore older .gdb_index sections by
2879 default, which could cause symbol files to be loaded more slowly
2880 until their .gdb_index sections can be recreated. The new command
2881 "set use-deprecated-index-sections on" will cause GDB to use any older
2882 .gdb_index sections it finds. This will restore performance, but the
2883 ability to set breakpoints on inlined functions will be lost in symbol
2884 files with older .gdb_index sections.
2886 The .gdb_index section has also been updated to record more information
2887 about each symbol. This speeds up the "info variables", "info functions"
2888 and "info types" commands when used with programs having the .gdb_index
2889 section, as well as speeding up debugging with shared libraries using
2890 the .gdb_index section.
2892 * Ada support for GDB/MI Variable Objects has been added.
2894 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2899 ** New command -info-os is the MI equivalent of "info os".
2901 ** Output logs ("set logging" and related) now include MI output.
2905 ** "set use-deprecated-index-sections on|off"
2906 "show use-deprecated-index-sections on|off"
2907 Controls the use of deprecated .gdb_index sections.
2909 ** "catch load" and "catch unload" can be used to stop when a shared
2910 library is loaded or unloaded, respectively.
2912 ** "enable count" can be used to auto-disable a breakpoint after
2915 ** "info vtbl" can be used to show the virtual method tables for
2916 C++ and Java objects.
2918 ** "explore" and its sub commands "explore value" and "explore type"
2919 can be used to recursively explore values and types of
2920 expressions. These commands are available only if GDB is
2921 configured with '--with-python'.
2923 ** "info auto-load" shows status of all kinds of auto-loaded files,
2924 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2925 sequences of commands files, "info auto-load python-scripts"
2926 shows status of auto-loading Python script files,
2927 "info auto-load local-gdbinit" shows status of loading init file
2928 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2929 status of inferior specific thread debugging shared library loading.
2931 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2932 and "show auto-load-scripts" commands have been deprecated, use their
2933 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2934 and "show auto-load python-scripts" counterparts instead.
2936 ** "dprintf location,format,args..." creates a dynamic printf, which
2937 is basically a breakpoint that does a printf and immediately
2938 resumes your program's execution, so it is like a printf that you
2939 can insert dynamically at runtime instead of at compiletime.
2941 ** "set print symbol"
2943 Controls whether GDB attempts to display the symbol, if any,
2944 corresponding to addresses it prints. This defaults to "on", but
2945 you can set it to "off" to restore GDB's previous behavior.
2947 * Deprecated commands
2949 ** For the Renesas Super-H architecture, the "regs" command has been
2950 deprecated, and "info all-registers" should be used instead.
2954 Renesas RL78 rl78-*-elf
2955 HP OpenVMS ia64 ia64-hp-openvms*
2957 * GDBserver supports evaluation of breakpoint conditions. When
2958 support is advertised by GDBserver, GDB may be told to send the
2959 breakpoint conditions in bytecode form to GDBserver. GDBserver
2960 will only report the breakpoint trigger to GDB when its condition
2965 set mips compression
2966 show mips compression
2967 Select the compressed ISA encoding used in functions that have no symbol
2968 information available. The encoding can be set to either of:
2971 and is updated automatically from ELF file flags if available.
2973 set breakpoint condition-evaluation
2974 show breakpoint condition-evaluation
2975 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2976 GDBserver ("target"). Default option "auto" chooses the most efficient
2978 This option can improve debugger efficiency depending on the speed of the
2982 Disable auto-loading globally.
2985 Show auto-loading setting of all kinds of auto-loaded files.
2987 set auto-load gdb-scripts on|off
2988 show auto-load gdb-scripts
2989 Control auto-loading of GDB canned sequences of commands files.
2991 set auto-load python-scripts on|off
2992 show auto-load python-scripts
2993 Control auto-loading of Python script files.
2995 set auto-load local-gdbinit on|off
2996 show auto-load local-gdbinit
2997 Control loading of init file (.gdbinit) from current directory.
2999 set auto-load libthread-db on|off
3000 show auto-load libthread-db
3001 Control auto-loading of inferior specific thread debugging shared library.
3003 set auto-load scripts-directory <dir1>[:<dir2>...]
3004 show auto-load scripts-directory
3005 Set a list of directories from which to load auto-loaded scripts.
3006 Automatically loaded Python scripts and GDB scripts are located in one
3007 of the directories listed by this option.
3008 The delimiter (':' above) may differ according to the host platform.
3010 set auto-load safe-path <dir1>[:<dir2>...]
3011 show auto-load safe-path
3012 Set a list of directories from which it is safe to auto-load files.
3013 The delimiter (':' above) may differ according to the host platform.
3015 set debug auto-load on|off
3016 show debug auto-load
3017 Control display of debugging info for auto-loading the files above.
3019 set dprintf-style gdb|call|agent
3021 Control the way in which a dynamic printf is performed; "gdb"
3022 requests a GDB printf command, while "call" causes dprintf to call a
3023 function in the inferior. "agent" requests that the target agent
3024 (such as GDBserver) do the printing.
3026 set dprintf-function <expr>
3027 show dprintf-function
3028 set dprintf-channel <expr>
3029 show dprintf-channel
3030 Set the function and optional first argument to the call when using
3031 the "call" style of dynamic printf.
3033 set disconnected-dprintf on|off
3034 show disconnected-dprintf
3035 Control whether agent-style dynamic printfs continue to be in effect
3036 after GDB disconnects.
3038 * New configure options
3040 --with-auto-load-dir
3041 Configure default value for the 'set auto-load scripts-directory'
3042 setting above. It defaults to '$debugdir:$datadir/auto-load',
3043 $debugdir representing global debugging info directories (available
3044 via 'show debug-file-directory') and $datadir representing GDB's data
3045 directory (available via 'show data-directory').
3047 --with-auto-load-safe-path
3048 Configure default value for the 'set auto-load safe-path' setting
3049 above. It defaults to the --with-auto-load-dir setting.
3051 --without-auto-load-safe-path
3052 Set 'set auto-load safe-path' to '/', effectively disabling this
3055 * New remote packets
3057 z0/z1 conditional breakpoints extension
3059 The z0/z1 breakpoint insertion packets have been extended to carry
3060 a list of conditional expressions over to the remote stub depending on the
3061 condition evaluation mode. The use of this extension can be controlled
3062 via the "set remote conditional-breakpoints-packet" command.
3066 Specify the signals which the remote stub may pass to the debugged
3067 program without GDB involvement.
3069 * New command line options
3071 --init-command=FILE, -ix Like --command, -x but execute it
3072 before loading inferior.
3073 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3074 execute it before loading inferior.
3076 *** Changes in GDB 7.4
3078 * GDB now handles ambiguous linespecs more consistently; the existing
3079 FILE:LINE support has been expanded to other types of linespecs. A
3080 breakpoint will now be set on all matching locations in all
3081 inferiors, and locations will be added or removed according to
3084 * GDB now allows you to skip uninteresting functions and files when
3085 stepping with the "skip function" and "skip file" commands.
3087 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3088 and "show remote hardware-watchpoint-length-limit". These allows to
3089 set or show the maximum length limit (in bytes) of a remote
3090 target hardware watchpoint.
3092 This allows e.g. to use "unlimited" hardware watchpoints with the
3093 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3094 watchpoints are slower than real hardware watchpoints but are
3095 significantly faster than gdb software watchpoints.
3099 ** The register_pretty_printer function in module gdb.printing now takes
3100 an optional `replace' argument. If True, the new printer replaces any
3103 ** The "maint set python print-stack on|off" command has been
3104 deprecated and will be deleted in GDB 7.5.
3105 A new command: "set python print-stack none|full|message" has
3106 replaced it. Additionally, the default for "print-stack" is
3107 now "message", which just prints the error message without
3110 ** A prompt substitution hook (prompt_hook) is now available to the
3113 ** A new Python module, gdb.prompt has been added to the GDB Python
3114 modules library. This module provides functionality for
3115 escape sequences in prompts (used by set/show
3116 extended-prompt). These escape sequences are replaced by their
3117 corresponding value.
3119 ** Python commands and convenience-functions located in
3120 'data-directory'/python/gdb/command and
3121 'data-directory'/python/gdb/function are now automatically loaded
3124 ** Blocks now provide four new attributes. global_block and
3125 static_block will return the global and static blocks
3126 respectively. is_static and is_global are boolean attributes
3127 that indicate if the block is one of those two types.
3129 ** Symbols now provide the "type" attribute, the type of the symbol.
3131 ** The "gdb.breakpoint" function has been deprecated in favor of
3134 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3135 of a function. This class is based on the "finish" command
3136 available in the CLI.
3138 ** Type objects for struct and union types now allow access to
3139 the fields using standard Python dictionary (mapping) methods.
3140 For example, "some_type['myfield']" now works, as does
3141 "some_type.items()".
3143 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3146 ** A new function, "deep_items" has been added to the gdb.types
3147 module in the GDB Python modules library. This function returns
3148 an iterator over the fields of a struct or union type. Unlike
3149 the standard Python "iteritems" method, it will recursively traverse
3150 any anonymous fields.
3154 ** "*stopped" events can report several new "reason"s, such as
3157 ** Breakpoint changes are now notified using new async records, like
3158 "=breakpoint-modified".
3160 ** New command -ada-task-info.
3162 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3163 $sdir specifies the default system locations of shared libraries.
3164 $pdir specifies the directory where the libpthread used by the application
3167 GDB no longer looks in $sdir and $pdir after it has searched the directories
3168 mentioned in libthread-db-search-path. If you want to search those
3169 directories, they must be specified in libthread-db-search-path.
3170 The default value of libthread-db-search-path on GNU/Linux and Solaris
3171 systems is now "$sdir:$pdir".
3173 $pdir is not supported by gdbserver, it is currently ignored.
3174 $sdir is supported by gdbserver.
3176 * New configure option --with-iconv-bin.
3177 When using the internationalization support like the one in the GNU C
3178 library, GDB will invoke the "iconv" program to get a list of supported
3179 character sets. If this program lives in a non-standard location, one can
3180 use this option to specify where to find it.
3182 * When natively debugging programs on PowerPC BookE processors running
3183 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3184 watchpoints, which specify a mask in addition to an address to watch.
3185 The mask specifies that some bits of an address (the bits which are
3186 reset in the mask) should be ignored when matching the address accessed
3187 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3188 section in the user manual for more details.
3190 * The new option --once causes GDBserver to stop listening for connections once
3191 the first connection is made. The listening port used by GDBserver will
3192 become available after that.
3194 * New commands "info macros" and "alias" have been added.
3196 * New function parameters suffix @entry specifies value of function parameter
3197 at the time the function got called. Entry values are available only since
3203 "!" is now an alias of the "shell" command.
3204 Note that no space is needed between "!" and SHELL COMMAND.
3208 watch EXPRESSION mask MASK_VALUE
3209 The watch command now supports the mask argument which allows creation
3210 of masked watchpoints, if the current architecture supports this feature.
3212 info auto-load-scripts [REGEXP]
3213 This command was formerly named "maintenance print section-scripts".
3214 It is now generally useful and is no longer a maintenance-only command.
3216 info macro [-all] [--] MACRO
3217 The info macro command has new options `-all' and `--'. The first for
3218 printing all definitions of a macro. The second for explicitly specifying
3219 the end of arguments and the beginning of the macro name in case the macro
3220 name starts with a hyphen.
3222 collect[/s] EXPRESSIONS
3223 The tracepoint collect command now takes an optional modifier "/s"
3224 that directs it to dereference pointer-to-character types and
3225 collect the bytes of memory up to a zero byte. The behavior is
3226 similar to what you see when you use the regular print command on a
3227 string. An optional integer following the "/s" sets a bound on the
3228 number of bytes that will be collected.
3231 The trace start command now interprets any supplied arguments as a
3232 note to be recorded with the trace run, with an effect similar to
3233 setting the variable trace-notes.
3236 The trace stop command now interprets any arguments as a note to be
3237 mentioned along with the tstatus report that the trace was stopped
3238 with a command. The effect is similar to setting the variable
3241 * Tracepoints can now be enabled and disabled at any time after a trace
3242 experiment has been started using the standard "enable" and "disable"
3243 commands. It is now possible to start a trace experiment with no enabled
3244 tracepoints; GDB will display a warning, but will allow the experiment to
3245 begin, assuming that tracepoints will be enabled as needed while the trace
3248 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3249 locations with 4-byte instructions, when they were previously
3250 limited to locations with instructions of 5 bytes or longer.
3254 set debug dwarf2-read
3255 show debug dwarf2-read
3256 Turns on or off display of debugging messages related to reading
3257 DWARF debug info. The default is off.
3259 set debug symtab-create
3260 show debug symtab-create
3261 Turns on or off display of debugging messages related to symbol table
3262 creation. The default is off.
3265 show extended-prompt
3266 Set the GDB prompt, and allow escape sequences to be inserted to
3267 display miscellaneous information (see 'help set extended-prompt'
3268 for the list of sequences). This prompt (and any information
3269 accessed through the escape sequences) is updated every time the
3270 prompt is displayed.
3272 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3273 show print entry-values
3274 Set printing of frame argument values at function entry. In some cases
3275 GDB can determine the value of function argument which was passed by the
3276 function caller, even if the value was modified inside the called function.
3278 set debug entry-values
3279 show debug entry-values
3280 Control display of debugging info for determining frame argument values at
3281 function entry and virtual tail call frames.
3283 set basenames-may-differ
3284 show basenames-may-differ
3285 Set whether a source file may have multiple base names.
3286 (A "base name" is the name of a file with the directory part removed.
3287 Example: The base name of "/home/user/hello.c" is "hello.c".)
3288 If set, GDB will canonicalize file names (e.g., expand symlinks)
3289 before comparing them. Canonicalization is an expensive operation,
3290 but it allows the same file be known by more than one base name.
3291 If not set (the default), all source files are assumed to have just
3292 one base name, and gdb will do file name comparisons more efficiently.
3298 Set a user name and notes for the current and any future trace runs.
3299 This is useful for long-running and/or disconnected traces, to
3300 inform others (or yourself) as to who is running the trace, supply
3301 contact information, or otherwise explain what is going on.
3303 set trace-stop-notes
3304 show trace-stop-notes
3305 Set a note attached to the trace run, that is displayed when the
3306 trace has been stopped by a tstop command. This is useful for
3307 instance as an explanation, if you are stopping a trace run that was
3308 started by someone else.
3310 * New remote packets
3314 Dynamically enable a tracepoint in a started trace experiment.
3318 Dynamically disable a tracepoint in a started trace experiment.
3322 Set the user and notes of the trace run.
3326 Query the current status of a tracepoint.
3330 Query the minimum length of instruction at which a fast tracepoint may
3333 * Dcache size (number of lines) and line-size are now runtime-configurable
3334 via "set dcache line" and "set dcache line-size" commands.
3338 Texas Instruments TMS320C6x tic6x-*-*
3342 Renesas RL78 rl78-*-elf
3344 *** Changes in GDB 7.3.1
3346 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3348 *** Changes in GDB 7.3
3350 * GDB has a new command: "thread find [REGEXP]".
3351 It finds the thread id whose name, target id, or thread extra info
3352 matches the given regular expression.
3354 * The "catch syscall" command now works on mips*-linux* targets.
3356 * The -data-disassemble MI command now supports modes 2 and 3 for
3357 dumping the instruction opcodes.
3359 * New command line options
3361 -data-directory DIR Specify DIR as the "data-directory".
3362 This is mostly for testing purposes.
3364 * The "maint set python auto-load on|off" command has been renamed to
3365 "set auto-load-scripts on|off".
3367 * GDB has a new command: "set directories".
3368 It is like the "dir" command except that it replaces the
3369 source path list instead of augmenting it.
3371 * GDB now understands thread names.
3373 On GNU/Linux, "info threads" will display the thread name as set by
3374 prctl or pthread_setname_np.
3376 There is also a new command, "thread name", which can be used to
3377 assign a name internally for GDB to display.
3380 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3381 has been integrated into GDB.
3385 ** The function gdb.Write now accepts an optional keyword 'stream'.
3386 This keyword, when provided, will direct the output to either
3387 stdout, stderr, or GDB's logging output.
3389 ** Parameters can now be be sub-classed in Python, and in particular
3390 you may implement the get_set_doc and get_show_doc functions.
3391 This improves how Parameter set/show documentation is processed
3392 and allows for more dynamic content.
3394 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3395 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3396 have an is_valid method.
3398 ** Breakpoints can now be sub-classed in Python, and in particular
3399 you may implement a 'stop' function that is executed each time
3400 the inferior reaches that breakpoint.
3402 ** New function gdb.lookup_global_symbol looks up a global symbol.
3404 ** GDB values in Python are now callable if the value represents a
3405 function. For example, if 'some_value' represents a function that
3406 takes two integer parameters and returns a value, you can call
3407 that function like so:
3409 result = some_value (10,20)
3411 ** Module gdb.types has been added.
3412 It contains a collection of utilities for working with gdb.Types objects:
3413 get_basic_type, has_field, make_enum_dict.
3415 ** Module gdb.printing has been added.
3416 It contains utilities for writing and registering pretty-printers.
3417 New classes: PrettyPrinter, SubPrettyPrinter,
3418 RegexpCollectionPrettyPrinter.
3419 New function: register_pretty_printer.
3421 ** New commands "info pretty-printers", "enable pretty-printer" and
3422 "disable pretty-printer" have been added.
3424 ** gdb.parameter("directories") is now available.
3426 ** New function gdb.newest_frame returns the newest frame in the
3429 ** The gdb.InferiorThread class has a new "name" attribute. This
3430 holds the thread's name.
3432 ** Python Support for Inferior events.
3433 Python scripts can add observers to be notified of events
3434 occurring in the process being debugged.
3435 The following events are currently supported:
3436 - gdb.events.cont Continue event.
3437 - gdb.events.exited Inferior exited event.
3438 - gdb.events.stop Signal received, and Breakpoint hit events.
3442 ** GDB now puts template parameters in scope when debugging in an
3443 instantiation. For example, if you have:
3445 template<int X> int func (void) { return X; }
3447 then if you step into func<5>, "print X" will show "5". This
3448 feature requires proper debuginfo support from the compiler; it
3449 was added to GCC 4.5.
3451 ** The motion commands "next", "finish", "until", and "advance" now
3452 work better when exceptions are thrown. In particular, GDB will
3453 no longer lose control of the inferior; instead, the GDB will
3454 stop the inferior at the point at which the exception is caught.
3455 This functionality requires a change in the exception handling
3456 code that was introduced in GCC 4.5.
3458 * GDB now follows GCC's rules on accessing volatile objects when
3459 reading or writing target state during expression evaluation.
3460 One notable difference to prior behavior is that "print x = 0"
3461 no longer generates a read of x; the value of the assignment is
3462 now always taken directly from the value being assigned.
3464 * GDB now has some support for using labels in the program's source in
3465 linespecs. For instance, you can use "advance label" to continue
3466 execution to a label.
3468 * GDB now has support for reading and writing a new .gdb_index
3469 section. This section holds a fast index of DWARF debugging
3470 information and can be used to greatly speed up GDB startup and
3471 operation. See the documentation for `save gdb-index' for details.
3473 * The "watch" command now accepts an optional "-location" argument.
3474 When used, this causes GDB to watch the memory referred to by the
3475 expression. Such a watchpoint is never deleted due to it going out
3478 * GDB now supports thread debugging of core dumps on GNU/Linux.
3480 GDB now activates thread debugging using the libthread_db library
3481 when debugging GNU/Linux core dumps, similarly to when debugging
3482 live processes. As a result, when debugging a core dump file, GDB
3483 is now able to display pthread_t ids of threads. For example, "info
3484 threads" shows the same output as when debugging the process when it
3485 was live. In earlier releases, you'd see something like this:
3488 * 1 LWP 6780 main () at main.c:10
3490 While now you see this:
3493 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3495 It is also now possible to inspect TLS variables when debugging core
3498 When debugging a core dump generated on a machine other than the one
3499 used to run GDB, you may need to point GDB at the correct
3500 libthread_db library with the "set libthread-db-search-path"
3501 command. See the user manual for more details on this command.
3503 * When natively debugging programs on PowerPC BookE processors running
3504 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3505 which stop execution of the inferior whenever it executes an instruction
3506 at any address within the specified range. See the "PowerPC Embedded"
3507 section in the user manual for more details.
3509 * New features in the GDB remote stub, GDBserver
3511 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3512 and i686 LynxOS (version 5.x).
3514 ** GDBserver is now supported on Blackfin Linux.
3516 * New native configurations
3518 ia64 HP-UX ia64-*-hpux*
3522 Analog Devices, Inc. Blackfin Processor bfin-*
3524 * Ada task switching is now supported on sparc-elf targets when
3525 debugging a program using the Ravenscar Profile. For more information,
3526 see the "Tasking Support when using the Ravenscar Profile" section
3527 in the GDB user manual.
3529 * Guile support was removed.
3531 * New features in the GNU simulator
3533 ** The --map-info flag lists all known core mappings.
3535 ** CFI flashes may be simulated via the "cfi" device.
3537 *** Changes in GDB 7.2
3539 * Shared library support for remote targets by default
3541 When GDB is configured for a generic, non-OS specific target, like
3542 for example, --target=arm-eabi or one of the many *-*-elf targets,
3543 GDB now queries remote stubs for loaded shared libraries using the
3544 `qXfer:libraries:read' packet. Previously, shared library support
3545 was always disabled for such configurations.
3549 ** Argument Dependent Lookup (ADL)
3551 In C++ ADL lookup directs function search to the namespaces of its
3552 arguments even if the namespace has not been imported.
3562 Here the compiler will search for `foo' in the namespace of 'b'
3563 and find A::foo. GDB now supports this. This construct is commonly
3564 used in the Standard Template Library for operators.
3566 ** Improved User Defined Operator Support
3568 In addition to member operators, GDB now supports lookup of operators
3569 defined in a namespace and imported with a `using' directive, operators
3570 defined in the global scope, operators imported implicitly from an
3571 anonymous namespace, and the ADL operators mentioned in the previous
3573 GDB now also supports proper overload resolution for all the previously
3574 mentioned flavors of operators.
3576 ** static const class members
3578 Printing of static const class members that are initialized in the
3579 class definition has been fixed.
3581 * Windows Thread Information Block access.
3583 On Windows targets, GDB now supports displaying the Windows Thread
3584 Information Block (TIB) structure. This structure is visible either
3585 by using the new command `info w32 thread-information-block' or, by
3586 dereferencing the new convenience variable named `$_tlb', a
3587 thread-specific pointer to the TIB. This feature is also supported
3588 when remote debugging using GDBserver.
3590 * Static tracepoints
3592 Static tracepoints are calls in the user program into a tracing
3593 library. One such library is a port of the LTTng kernel tracer to
3594 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3595 When debugging with GDBserver, GDB now supports combining the GDB
3596 tracepoint machinery with such libraries. For example: the user can
3597 use GDB to probe a static tracepoint marker (a call from the user
3598 program into the tracing library) with the new "strace" command (see
3599 "New commands" below). This creates a "static tracepoint" in the
3600 breakpoint list, that can be manipulated with the same feature set
3601 as fast and regular tracepoints. E.g., collect registers, local and
3602 global variables, collect trace state variables, and define
3603 tracepoint conditions. In addition, the user can collect extra
3604 static tracepoint marker specific data, by collecting the new
3605 $_sdata internal variable. When analyzing the trace buffer, you can
3606 inspect $_sdata like any other variable available to GDB. For more
3607 information, see the "Tracepoints" chapter in GDB user manual. New
3608 remote packets have been defined to support static tracepoints, see
3609 the "New remote packets" section below.
3611 * Better reconstruction of tracepoints after disconnected tracing
3613 GDB will attempt to download the original source form of tracepoint
3614 definitions when starting a trace run, and then will upload these
3615 upon reconnection to the target, resulting in a more accurate
3616 reconstruction of the tracepoints that are in use on the target.
3620 You can now exercise direct control over the ways that GDB can
3621 affect your program. For instance, you can disallow the setting of
3622 breakpoints, so that the program can run continuously (assuming
3623 non-stop mode). In addition, the "observer" variable is available
3624 to switch all of the different controls; in observer mode, GDB
3625 cannot affect the target's behavior at all, which is useful for
3626 tasks like diagnosing live systems in the field.
3628 * The new convenience variable $_thread holds the number of the
3631 * New remote packets
3635 Return the address of the Windows Thread Information Block of a given thread.
3639 In response to several of the tracepoint packets, the target may now
3640 also respond with a number of intermediate `qRelocInsn' request
3641 packets before the final result packet, to have GDB handle
3642 relocating an instruction to execute at a different address. This
3643 is particularly useful for stubs that support fast tracepoints. GDB
3644 reports support for this feature in the qSupported packet.
3648 List static tracepoint markers in the target program.
3652 List static tracepoint markers at a given address in the target
3655 qXfer:statictrace:read
3657 Read the static trace data collected (by a `collect $_sdata'
3658 tracepoint action). The remote stub reports support for this packet
3659 to gdb's qSupported query.
3663 Send the current settings of GDB's permission flags.
3667 Send part of the source (textual) form of a tracepoint definition,
3668 which includes location, conditional, and action list.
3670 * The source command now accepts a -s option to force searching for the
3671 script in the source search path even if the script name specifies
3674 * New features in the GDB remote stub, GDBserver
3676 - GDBserver now support tracepoints (including fast tracepoints, and
3677 static tracepoints). The feature is currently supported by the
3678 i386-linux and amd64-linux builds. See the "Tracepoints support
3679 in gdbserver" section in the manual for more information.
3681 GDBserver JIT compiles the tracepoint's conditional agent
3682 expression bytecode into native code whenever possible for low
3683 overhead dynamic tracepoints conditionals. For such tracepoints,
3684 an expression that examines program state is evaluated when the
3685 tracepoint is reached, in order to determine whether to capture
3686 trace data. If the condition is simple and false, processing the
3687 tracepoint finishes very quickly and no data is gathered.
3689 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3690 for static tracepoints support.
3692 - GDBserver now supports x86_64 Windows 64-bit debugging.
3694 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3695 it understands register description.
3697 * The --batch flag now disables pagination and queries.
3699 * X86 general purpose registers
3701 GDB now supports reading/writing byte, word and double-word x86
3702 general purpose registers directly. This means you can use, say,
3703 $ah or $ax to refer, respectively, to the byte register AH and
3704 16-bit word register AX that are actually portions of the 32-bit
3705 register EAX or 64-bit register RAX.
3707 * The `commands' command now accepts a range of breakpoints to modify.
3708 A plain `commands' following a command that creates multiple
3709 breakpoints affects all the breakpoints set by that command. This
3710 applies to breakpoints set by `rbreak', and also applies when a
3711 single `break' command creates multiple breakpoints (e.g.,
3712 breakpoints on overloaded c++ functions).
3714 * The `rbreak' command now accepts a filename specification as part of
3715 its argument, limiting the functions selected by the regex to those
3716 in the specified file.
3718 * Support for remote debugging Windows and SymbianOS shared libraries
3719 from Unix hosts has been improved. Non Windows GDB builds now can
3720 understand target reported file names that follow MS-DOS based file
3721 system semantics, such as file names that include drive letters and
3722 use the backslash character as directory separator. This makes it
3723 possible to transparently use the "set sysroot" and "set
3724 solib-search-path" on Unix hosts to point as host copies of the
3725 target's shared libraries. See the new command "set
3726 target-file-system-kind" described below, and the "Commands to
3727 specify files" section in the user manual for more information.
3731 eval template, expressions...
3732 Convert the values of one or more expressions under the control
3733 of the string template to a command line, and call it.
3735 set target-file-system-kind unix|dos-based|auto
3736 show target-file-system-kind
3737 Set or show the assumed file system kind for target reported file
3740 save breakpoints <filename>
3741 Save all current breakpoint definitions to a file suitable for use
3742 in a later debugging session. To read the saved breakpoint
3743 definitions, use the `source' command.
3745 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3748 info static-tracepoint-markers
3749 Display information about static tracepoint markers in the target.
3751 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3752 Define a static tracepoint by probing a marker at the given
3753 function, line, address, or marker ID.
3757 Enable and disable observer mode.
3759 set may-write-registers on|off
3760 set may-write-memory on|off
3761 set may-insert-breakpoints on|off
3762 set may-insert-tracepoints on|off
3763 set may-insert-fast-tracepoints on|off
3764 set may-interrupt on|off
3765 Set individual permissions for GDB effects on the target. Note that
3766 some of these settings can have undesirable or surprising
3767 consequences, particularly when changed in the middle of a session.
3768 For instance, disabling the writing of memory can prevent
3769 breakpoints from being inserted, cause single-stepping to fail, or
3770 even crash your program, if you disable after breakpoints have been
3771 inserted. However, GDB should not crash.
3773 set record memory-query on|off
3774 show record memory-query
3775 Control whether to stop the inferior if memory changes caused
3776 by an instruction cannot be recorded.
3781 The disassemble command now supports "start,+length" form of two arguments.
3785 ** GDB now provides a new directory location, called the python directory,
3786 where Python scripts written for GDB can be installed. The location
3787 of that directory is <data-directory>/python, where <data-directory>
3788 is the GDB data directory. For more details, see section `Scripting
3789 GDB using Python' in the manual.
3791 ** The GDB Python API now has access to breakpoints, symbols, symbol
3792 tables, program spaces, inferiors, threads and frame's code blocks.
3793 Additionally, GDB Parameters can now be created from the API, and
3794 manipulated via set/show in the CLI.
3796 ** New functions gdb.target_charset, gdb.target_wide_charset,
3797 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3799 ** New exception gdb.GdbError.
3801 ** Pretty-printers are now also looked up in the current program space.
3803 ** Pretty-printers can now be individually enabled and disabled.
3805 ** GDB now looks for names of Python scripts to auto-load in a
3806 special section named `.debug_gdb_scripts', in addition to looking
3807 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3809 * Tracepoint actions were unified with breakpoint commands. In particular,
3810 there are no longer differences in "info break" output for breakpoints and
3811 tracepoints and the "commands" command can be used for both tracepoints and
3812 regular breakpoints.
3816 ARM Symbian arm*-*-symbianelf*
3818 * D language support.
3819 GDB now supports debugging programs written in the D programming
3822 * GDB now supports the extended ptrace interface for PowerPC which is
3823 available since Linux kernel version 2.6.34. This automatically enables
3824 any hardware breakpoints and additional hardware watchpoints available in
3825 the processor. The old ptrace interface exposes just one hardware
3826 watchpoint and no hardware breakpoints.
3828 * GDB is now able to use the Data Value Compare (DVC) register available on
3829 embedded PowerPC processors to implement in hardware simple watchpoint
3830 conditions of the form:
3832 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3834 This works in native GDB running on Linux kernels with the extended ptrace
3835 interface mentioned above.
3837 *** Changes in GDB 7.1
3841 ** Namespace Support
3843 GDB now supports importing of namespaces in C++. This enables the
3844 user to inspect variables from imported namespaces. Support for
3845 namepace aliasing has also been added. So, if a namespace is
3846 aliased in the current scope (e.g. namepace C=A; ) the user can
3847 print variables using the alias (e.g. (gdb) print C::x).
3851 All known bugs relating to the printing of virtual base class were
3852 fixed. It is now possible to call overloaded static methods using a
3857 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3858 and reinterpret_cast<> are now handled by the C++ expression parser.
3862 Xilinx MicroBlaze microblaze-*-*
3867 Xilinx MicroBlaze microblaze
3870 * Multi-program debugging.
3872 GDB now has support for multi-program (a.k.a. multi-executable or
3873 multi-exec) debugging. This allows for debugging multiple inferiors
3874 simultaneously each running a different program under the same GDB
3875 session. See "Debugging Multiple Inferiors and Programs" in the
3876 manual for more information. This implied some user visible changes
3877 in the multi-inferior support. For example, "info inferiors" now
3878 lists inferiors that are not running yet or that have exited
3879 already. See also "New commands" and "New options" below.
3881 * New tracing features
3883 GDB's tracepoint facility now includes several new features:
3885 ** Trace state variables
3887 GDB tracepoints now include support for trace state variables, which
3888 are variables managed by the target agent during a tracing
3889 experiment. They are useful for tracepoints that trigger each
3890 other, so for instance one tracepoint can count hits in a variable,
3891 and then a second tracepoint has a condition that is true when the
3892 count reaches a particular value. Trace state variables share the
3893 $-syntax of GDB convenience variables, and can appear in both
3894 tracepoint actions and condition expressions. Use the "tvariable"
3895 command to create, and "info tvariables" to view; see "Trace State
3896 Variables" in the manual for more detail.
3900 GDB now includes an option for defining fast tracepoints, which
3901 targets may implement more efficiently, such as by installing a jump
3902 into the target agent rather than a trap instruction. The resulting
3903 speedup can be by two orders of magnitude or more, although the
3904 tradeoff is that some program locations on some target architectures
3905 might not allow fast tracepoint installation, for instance if the
3906 instruction to be replaced is shorter than the jump. To request a
3907 fast tracepoint, use the "ftrace" command, with syntax identical to
3908 the regular trace command.
3910 ** Disconnected tracing
3912 It is now possible to detach GDB from the target while it is running
3913 a trace experiment, then reconnect later to see how the experiment
3914 is going. In addition, a new variable disconnected-tracing lets you
3915 tell the target agent whether to continue running a trace if the
3916 connection is lost unexpectedly.
3920 GDB now has the ability to save the trace buffer into a file, and
3921 then use that file as a target, similarly to you can do with
3922 corefiles. You can select trace frames, print data that was
3923 collected in them, and use tstatus to display the state of the
3924 tracing run at the moment that it was saved. To create a trace
3925 file, use "tsave <filename>", and to use it, do "target tfile
3928 ** Circular trace buffer
3930 You can ask the target agent to handle the trace buffer as a
3931 circular buffer, discarding the oldest trace frames to make room for
3932 newer ones, by setting circular-trace-buffer to on. This feature may
3933 not be available for all target agents.
3938 The disassemble command, when invoked with two arguments, now requires
3939 the arguments to be comma-separated.
3942 The info variables command now displays variable definitions. Files
3943 which only declare a variable are not shown.
3946 The source command is now capable of sourcing Python scripts.
3947 This feature is dependent on the debugger being build with Python
3950 Related to this enhancement is also the introduction of a new command
3951 "set script-extension" (see below).
3953 * New commands (for set/show, see "New options" below)
3955 record save [<FILENAME>]
3956 Save a file (in core file format) containing the process record
3957 execution log for replay debugging at a later time.
3959 record restore <FILENAME>
3960 Restore the process record execution log that was saved at an
3961 earlier time, for replay debugging.
3963 add-inferior [-copies <N>] [-exec <FILENAME>]
3966 clone-inferior [-copies <N>] [ID]
3967 Make a new inferior ready to execute the same program another
3968 inferior has loaded.
3973 maint info program-spaces
3974 List the program spaces loaded into GDB.
3976 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3977 show remote interrupt-sequence
3978 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3979 as the sequence to the remote target in order to interrupt the execution.
3980 Ctrl-C is a default. Some system prefers BREAK which is high level of
3981 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3982 Magic SysRq g. It is BREAK signal and character 'g'.
3984 set remote interrupt-on-connect [on | off]
3985 show remote interrupt-on-connect
3986 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3987 remote target when gdb connects to it. This is needed when you debug
3990 set remotebreak [on | off]
3992 Deprecated. Use "set/show remote interrupt-sequence" instead.
3994 tvariable $NAME [ = EXP ]
3995 Create or modify a trace state variable.
3998 List trace state variables and their values.
4000 delete tvariable $NAME ...
4001 Delete one or more trace state variables.
4004 Evaluate the given expressions without collecting anything into the
4005 trace buffer. (Valid in tracepoint actions only.)
4007 ftrace FN / FILE:LINE / *ADDR
4008 Define a fast tracepoint at the given function, line, or address.
4010 * New expression syntax
4012 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4013 GDB now parses 0b101010 identically with 42.
4017 set follow-exec-mode new|same
4018 show follow-exec-mode
4019 Control whether GDB reuses the same inferior across an exec call or
4020 creates a new one. This is useful to be able to restart the old
4021 executable after the inferior having done an exec call.
4023 set default-collect EXPR, ...
4024 show default-collect
4025 Define a list of expressions to be collected at each tracepoint.
4026 This is a useful way to ensure essential items are not overlooked,
4027 such as registers or a critical global variable.
4029 set disconnected-tracing
4030 show disconnected-tracing
4031 If set to 1, the target is instructed to continue tracing if it
4032 loses its connection to GDB. If 0, the target is to stop tracing
4035 set circular-trace-buffer
4036 show circular-trace-buffer
4037 If set to on, the target is instructed to use a circular trace buffer
4038 and discard the oldest trace frames instead of stopping the trace due
4039 to a full trace buffer. If set to off, the trace stops when the buffer
4040 fills up. Some targets may not support this.
4042 set script-extension off|soft|strict
4043 show script-extension
4044 If set to "off", the debugger does not perform any script language
4045 recognition, and all sourced files are assumed to be GDB scripts.
4046 If set to "soft" (the default), files are sourced according to
4047 filename extension, falling back to GDB scripts if the first
4049 If set to "strict", files are sourced according to filename extension.
4051 set ada trust-PAD-over-XVS on|off
4052 show ada trust-PAD-over-XVS
4053 If off, activate a workaround against a bug in the debugging information
4054 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4055 the GCC sources for more information about the GNAT encoding and
4056 PAD types in particular). It is always safe to set this option to
4057 off, but this introduces a slight performance penalty. The default
4060 * Python API Improvements
4062 ** GDB provides the new class gdb.LazyString. This is useful in
4063 some pretty-printing cases. The new method gdb.Value.lazy_string
4064 provides a simple way to create objects of this type.
4066 ** The fields returned by gdb.Type.fields now have an
4067 `is_base_class' attribute.
4069 ** The new method gdb.Type.range returns the range of an array type.
4071 ** The new method gdb.parse_and_eval can be used to parse and
4072 evaluate an expression.
4074 * New remote packets
4077 Define a trace state variable.
4080 Get the current value of a trace state variable.
4083 Set desired tracing behavior upon disconnection.
4086 Set the trace buffer to be linear or circular.
4089 Get data about the tracepoints currently in use.
4093 Process record now works correctly with hardware watchpoints.
4095 Multiple bug fixes have been made to the mips-irix port, making it
4096 much more reliable. In particular:
4097 - Debugging threaded applications is now possible again. Previously,
4098 GDB would hang while starting the program, or while waiting for
4099 the program to stop at a breakpoint.
4100 - Attaching to a running process no longer hangs.
4101 - An error occurring while loading a core file has been fixed.
4102 - Changing the value of the PC register now works again. This fixes
4103 problems observed when using the "jump" command, or when calling
4104 a function from GDB, or even when assigning a new value to $pc.
4105 - With the "finish" and "return" commands, the return value for functions
4106 returning a small array is now correctly printed.
4107 - It is now possible to break on shared library code which gets executed
4108 during a shared library init phase (code executed while executing
4109 their .init section). Previously, the breakpoint would have no effect.
4110 - GDB is now able to backtrace through the signal handler for
4111 non-threaded programs.
4113 PIE (Position Independent Executable) programs debugging is now supported.
4114 This includes debugging execution of PIC (Position Independent Code) shared
4115 libraries although for that, it should be possible to run such libraries as an
4118 *** Changes in GDB 7.0
4120 * GDB now has an interface for JIT compilation. Applications that
4121 dynamically generate code can create symbol files in memory and register
4122 them with GDB. For users, the feature should work transparently, and
4123 for JIT developers, the interface is documented in the GDB manual in the
4124 "JIT Compilation Interface" chapter.
4126 * Tracepoints may now be conditional. The syntax is as for
4127 breakpoints; either an "if" clause appended to the "trace" command,
4128 or the "condition" command is available. GDB sends the condition to
4129 the target for evaluation using the same bytecode format as is used
4130 for tracepoint actions.
4132 * The disassemble command now supports: an optional /r modifier, print the
4133 raw instructions in hex as well as in symbolic form, and an optional /m
4134 modifier to print mixed source+assembly.
4136 * Process record and replay
4138 In a architecture environment that supports ``process record and
4139 replay'', ``process record and replay'' target can record a log of
4140 the process execution, and replay it with both forward and reverse
4143 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4144 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4145 set execution-direction {forward|reverse}, for targets that support
4148 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4149 feature is available with a native GDB running on kernel version
4152 * GDB now has support for multi-byte and wide character sets on the
4153 target. Strings whose character type is wchar_t, char16_t, or
4154 char32_t are now correctly printed. GDB supports wide- and unicode-
4155 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4156 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4157 `printf'. This feature requires iconv to work properly; if your
4158 system does not have a working iconv, GDB can use GNU libiconv. See
4159 the installation instructions for more information.
4161 * GDB now supports automatic retrieval of shared library files from
4162 remote targets. To use this feature, specify a system root that begins
4163 with the `remote:' prefix, either via the `set sysroot' command or via
4164 the `--with-sysroot' configure-time option.
4166 * "info sharedlibrary" now takes an optional regex of libraries to show,
4167 and it now reports if a shared library has no debugging information.
4169 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4170 now complete on file names.
4172 * When completing in expressions, gdb will attempt to limit
4173 completions to allowable structure or union fields, where appropriate.
4174 For instance, consider:
4176 # struct example { int f1; double f2; };
4177 # struct example variable;
4180 If the user types TAB at the end of this command line, the available
4181 completions will be "f1" and "f2".
4183 * Inlined functions are now supported. They show up in backtraces, and
4184 the "step", "next", and "finish" commands handle them automatically.
4186 * GDB now supports the token-splicing (##) and stringification (#)
4187 operators when expanding macros. It also supports variable-arity
4190 * GDB now supports inspecting extra signal information, exported by
4191 the new $_siginfo convenience variable. The feature is currently
4192 implemented on linux ARM, i386 and amd64.
4194 * GDB can now display the VFP floating point registers and NEON vector
4195 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4196 can provide these registers (requires Linux 2.6.30 or later). Remote
4197 and simulator targets may also provide them.
4199 * New remote packets
4202 Search memory for a sequence of bytes.
4205 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4206 operation over reliable transport links. Use of this packet is
4207 controlled by the `set remote noack-packet' command.
4210 Kill the process with the specified process ID. Use this in preference
4211 to `k' when multiprocess protocol extensions are supported.
4214 Obtains additional operating system information
4218 Read or write additional signal information.
4220 * Removed remote protocol undocumented extension
4222 An undocumented extension to the remote protocol's `S' stop reply
4223 packet that permited the stub to pass a process id was removed.
4224 Remote servers should use the `T' stop reply packet instead.
4226 * GDB now supports multiple function calling conventions according to the
4227 DWARF-2 DW_AT_calling_convention function attribute.
4229 * The SH target utilizes the aforementioned change to distinguish between gcc
4230 and Renesas calling convention. It also adds the new CLI commands
4231 `set/show sh calling-convention'.
4233 * GDB can now read compressed debug sections, as produced by GNU gold
4234 with the --compress-debug-sections=zlib flag.
4236 * 64-bit core files are now supported on AIX.
4238 * Thread switching is now supported on Tru64.
4240 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4241 which will be allocated using malloc later in program execution.
4243 * The qXfer:libraries:read remote procotol packet now allows passing a
4244 list of section offsets.
4246 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4247 conditions handling signals delivered during attach or thread creation
4248 have also been fixed.
4250 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4251 From the user's standpoint, all unqualified instances of True and False
4252 are treated as the standard definitions, regardless of context.
4254 * GDB now parses C++ symbol and type names more flexibly. For
4257 template<typename T> class C { };
4260 GDB will now correctly handle all of:
4262 ptype C<char const *>
4263 ptype C<char const*>
4264 ptype C<const char *>
4265 ptype C<const char*>
4267 * New features in the GDB remote stub, gdbserver
4269 - The "--wrapper" command-line argument tells gdbserver to use a
4270 wrapper program to launch programs for debugging.
4272 - On PowerPC and S/390 targets, it is now possible to use a single
4273 gdbserver executable to debug both 32-bit and 64-bit programs.
4274 (This requires gdbserver itself to be built as a 64-bit executable.)
4276 - gdbserver uses the new noack protocol mode for TCP connections to
4277 reduce communications latency, if also supported and enabled in GDB.
4279 - Support for the sparc64-linux-gnu target is now included in
4282 - The amd64-linux build of gdbserver now supports debugging both
4283 32-bit and 64-bit programs.
4285 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4286 now support hardware watchpoints, and will use them automatically
4291 GDB now has support for scripting using Python. Whether this is
4292 available is determined at configure time.
4294 New GDB commands can now be written in Python.
4296 * Ada tasking support
4298 Ada tasks can now be inspected in GDB. The following commands have
4302 Print the list of Ada tasks.
4304 Print detailed information about task number N.
4306 Print the task number of the current task.
4308 Switch the context of debugging to task number N.
4310 * Support for user-defined prefixed commands. The "define" command can
4311 add new commands to existing prefixes, e.g. "target".
4313 * Multi-inferior, multi-process debugging.
4315 GDB now has generalized support for multi-inferior debugging. See
4316 "Debugging Multiple Inferiors" in the manual for more information.
4317 Although availability still depends on target support, the command
4318 set is more uniform now. The GNU/Linux specific multi-forks support
4319 has been migrated to this new framework. This implied some user
4320 visible changes; see "New commands" and also "Removed commands"
4323 * Target descriptions can now describe the target OS ABI. See the
4324 "Target Description Format" section in the user manual for more
4327 * Target descriptions can now describe "compatible" architectures
4328 to indicate that the target can execute applications for a different
4329 architecture in addition to those for the main target architecture.
4330 See the "Target Description Format" section in the user manual for
4333 * Multi-architecture debugging.
4335 GDB now includes general supports for debugging applications on
4336 hybrid systems that use more than one single processor architecture
4337 at the same time. Each such hybrid architecture still requires
4338 specific support to be added. The only hybrid architecture supported
4339 in this version of GDB is the Cell Broadband Engine.
4341 * GDB now supports integrated debugging of Cell/B.E. applications that
4342 use both the PPU and SPU architectures. To enable support for hybrid
4343 Cell/B.E. debugging, you need to configure GDB to support both the
4344 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4345 --enable-targets configure option.
4347 * Non-stop mode debugging.
4349 For some targets, GDB now supports an optional mode of operation in
4350 which you can examine stopped threads while other threads continue
4351 to execute freely. This is referred to as non-stop mode, with the
4352 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4353 section in the user manual for more information.
4355 To be able to support remote non-stop debugging, a remote stub needs
4356 to implement the non-stop mode remote protocol extensions, as
4357 described in the "Remote Non-Stop" section of the user manual. The
4358 GDB remote stub, gdbserver, has been adjusted to support these
4359 extensions on linux targets.
4361 * New commands (for set/show, see "New options" below)
4363 catch syscall [NAME(S) | NUMBER(S)]
4364 Catch system calls. Arguments, which should be names of system
4365 calls or their numbers, mean catch only those syscalls. Without
4366 arguments, every syscall will be caught. When the inferior issues
4367 any of the specified syscalls, GDB will stop and announce the system
4368 call, both when it is called and when its call returns. This
4369 feature is currently available with a native GDB running on the
4370 Linux Kernel, under the following architectures: x86, x86_64,
4371 PowerPC and PowerPC64.
4373 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4375 Search memory for a sequence of bytes.
4377 maint set python print-stack
4378 maint show python print-stack
4379 Show a stack trace when an error is encountered in a Python script.
4382 Invoke CODE by passing it to the Python interpreter.
4387 These allow macros to be defined, undefined, and listed
4391 Show operating system information about processes.
4394 List the inferiors currently under GDB's control.
4397 Switch focus to inferior number NUM.
4400 Detach from inferior number NUM.
4403 Kill inferior number NUM.
4407 set spu stop-on-load
4408 show spu stop-on-load
4409 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4411 set spu auto-flush-cache
4412 show spu auto-flush-cache
4413 Control whether to automatically flush the software-managed cache
4414 during Cell/B.E. debugging.
4416 set sh calling-convention
4417 show sh calling-convention
4418 Control the calling convention used when calling SH target functions.
4421 show debug timestamp
4422 Control display of timestamps with GDB debugging output.
4424 set disassemble-next-line
4425 show disassemble-next-line
4426 Control display of disassembled source lines or instructions when
4429 set remote noack-packet
4430 show remote noack-packet
4431 Set/show the use of remote protocol QStartNoAckMode packet. See above
4432 under "New remote packets."
4434 set remote query-attached-packet
4435 show remote query-attached-packet
4436 Control use of remote protocol `qAttached' (query-attached) packet.
4438 set remote read-siginfo-object
4439 show remote read-siginfo-object
4440 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4443 set remote write-siginfo-object
4444 show remote write-siginfo-object
4445 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4448 set remote reverse-continue
4449 show remote reverse-continue
4450 Control use of remote protocol 'bc' (reverse-continue) packet.
4452 set remote reverse-step
4453 show remote reverse-step
4454 Control use of remote protocol 'bs' (reverse-step) packet.
4456 set displaced-stepping
4457 show displaced-stepping
4458 Control displaced stepping mode. Displaced stepping is a way to
4459 single-step over breakpoints without removing them from the debuggee.
4460 Also known as "out-of-line single-stepping".
4463 show debug displaced
4464 Control display of debugging info for displaced stepping.
4466 maint set internal-error
4467 maint show internal-error
4468 Control what GDB does when an internal error is detected.
4470 maint set internal-warning
4471 maint show internal-warning
4472 Control what GDB does when an internal warning is detected.
4477 Use a wrapper program to launch programs for debugging.
4479 set multiple-symbols (all|ask|cancel)
4480 show multiple-symbols
4481 The value of this variable can be changed to adjust the debugger behavior
4482 when an expression or a breakpoint location contains an ambiguous symbol
4483 name (an overloaded function name, for instance).
4485 set breakpoint always-inserted
4486 show breakpoint always-inserted
4487 Keep breakpoints always inserted in the target, as opposed to inserting
4488 them when resuming the target, and removing them when the target stops.
4489 This option can improve debugger performance on slow remote targets.
4491 set arm fallback-mode (arm|thumb|auto)
4492 show arm fallback-mode
4493 set arm force-mode (arm|thumb|auto)
4495 These commands control how ARM GDB determines whether instructions
4496 are ARM or Thumb. The default for both settings is auto, which uses
4497 the current CPSR value for instructions without symbols; previous
4498 versions of GDB behaved as if "set arm fallback-mode arm".
4500 set disable-randomization
4501 show disable-randomization
4502 Standalone programs run with the virtual address space randomization enabled
4503 by default on some platforms. This option keeps the addresses stable across
4504 multiple debugging sessions.
4508 Control whether other threads are stopped or not when some thread hits
4513 Requests that asynchronous execution is enabled in the target, if available.
4514 In this case, it's possible to resume target in the background, and interact
4515 with GDB while the target is running. "show target-async" displays the
4516 current state of asynchronous execution of the target.
4518 set target-wide-charset
4519 show target-wide-charset
4520 The target-wide-charset is the name of the character set that GDB
4521 uses when printing characters whose type is wchar_t.
4523 set tcp auto-retry (on|off)
4525 set tcp connect-timeout
4526 show tcp connect-timeout
4527 These commands allow GDB to retry failed TCP connections to a remote stub
4528 with a specified timeout period; this is useful if the stub is launched
4529 in parallel with GDB but may not be ready to accept connections immediately.
4531 set libthread-db-search-path
4532 show libthread-db-search-path
4533 Control list of directories which GDB will search for appropriate
4536 set schedule-multiple (on|off)
4537 show schedule-multiple
4538 Allow GDB to resume all threads of all processes or only threads of
4539 the current process.
4543 Use more aggressive caching for accesses to the stack. This improves
4544 performance of remote debugging (particularly backtraces) without
4545 affecting correctness.
4547 set interactive-mode (on|off|auto)
4548 show interactive-mode
4549 Control whether GDB runs in interactive mode (on) or not (off).
4550 When in interactive mode, GDB waits for the user to answer all
4551 queries. Otherwise, GDB does not wait and assumes the default
4552 answer. When set to auto (the default), GDB determines which
4553 mode to use based on the stdin settings.
4558 For program forks, this is replaced by the new more generic `info
4559 inferiors' command. To list checkpoints, you can still use the
4560 `info checkpoints' command, which was an alias for the `info forks'
4564 Replaced by the new `inferior' command. To switch between
4565 checkpoints, you can still use the `restart' command, which was an
4566 alias for the `fork' command.
4569 This is removed, since some targets don't have a notion of
4570 processes. To switch between processes, you can still use the
4571 `inferior' command using GDB's own inferior number.
4574 For program forks, this is replaced by the new more generic `kill
4575 inferior' command. To delete a checkpoint, you can still use the
4576 `delete checkpoint' command, which was an alias for the `delete
4580 For program forks, this is replaced by the new more generic `detach
4581 inferior' command. To detach a checkpoint, you can still use the
4582 `detach checkpoint' command, which was an alias for the `detach
4585 * New native configurations
4587 x86/x86_64 Darwin i[34567]86-*-darwin*
4589 x86_64 MinGW x86_64-*-mingw*
4593 Lattice Mico32 lm32-*
4594 x86 DICOS i[34567]86-*-dicos*
4595 x86_64 DICOS x86_64-*-dicos*
4598 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4599 (mingw32ce) debugging.
4605 These commands were actually not implemented on any target.
4607 *** Changes in GDB 6.8
4609 * New native configurations
4611 NetBSD/hppa hppa*-*netbsd*
4612 Xtensa GNU/Linux xtensa*-*-linux*
4616 NetBSD/hppa hppa*-*-netbsd*
4617 Xtensa GNU/Lunux xtensa*-*-linux*
4619 * Change in command line behavior -- corefiles vs. process ids.
4621 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4622 attaching to process NUMBER fails, GDB no longer attempts to open a
4623 core file named NUMBER. Attaching to a program using the -c option
4624 is no longer supported. Instead, use the '-p' or '--pid' options.
4626 * GDB can now be built as a native debugger for debugging Windows x86
4627 (mingw32) Portable Executable (PE) programs.
4629 * Pending breakpoints no longer change their number when their address
4632 * GDB now supports breakpoints with multiple locations,
4633 including breakpoints on C++ constructors, inside C++ templates,
4634 and in inlined functions.
4636 * GDB's ability to debug optimized code has been improved. GDB more
4637 accurately identifies function bodies and lexical blocks that occupy
4638 more than one contiguous range of addresses.
4640 * Target descriptions can now describe registers for PowerPC.
4642 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4643 registers on PowerPC targets.
4645 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4646 targets even when the libthread_db library is not available.
4648 * The GDB remote stub, gdbserver, now supports the new file transfer
4649 commands (remote put, remote get, and remote delete).
4651 * The GDB remote stub, gdbserver, now supports run and attach in
4652 extended-remote mode.
4654 * hppa*64*-*-hpux11* target broken
4655 The debugger is unable to start a program and fails with the following
4656 error: "Error trying to get information about dynamic linker".
4657 The gdb-6.7 release is also affected.
4659 * GDB now supports the --enable-targets= configure option to allow
4660 building a single GDB executable that supports multiple remote
4661 target architectures.
4663 * GDB now supports debugging C and C++ programs which use the
4664 Decimal Floating Point extension. In addition, the PowerPC target
4665 now has a set of pseudo-registers to inspect decimal float values
4666 stored in two consecutive float registers.
4668 * The -break-insert MI command can optionally create pending
4671 * Improved support for debugging Ada
4672 Many improvements to the Ada language support have been made. These
4674 - Better support for Ada2005 interface types
4675 - Improved handling of arrays and slices in general
4676 - Better support for Taft-amendment types
4677 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4679 - Improved command completion in Ada
4682 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4687 set print frame-arguments (all|scalars|none)
4688 show print frame-arguments
4689 The value of this variable can be changed to control which argument
4690 values should be printed by the debugger when displaying a frame.
4695 Transfer files to and from a remote target, and delete remote files.
4702 Transfer files to and from a remote target, and delete remote files.
4704 * New remote packets
4711 Open, close, read, write, and delete files on the remote system.
4714 Attach to an existing process on the remote system, in extended-remote
4718 Run a new process on the remote system, in extended-remote mode.
4720 *** Changes in GDB 6.7
4722 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4723 bfd, libiberty and opcodes, as revealed by static analysis donated by
4724 Coverity, Inc. (http://scan.coverity.com).
4726 * When looking up multiply-defined global symbols, GDB will now prefer the
4727 symbol definition in the current shared library if it was built using the
4728 -Bsymbolic linker option.
4730 * When the Text User Interface (TUI) is not configured, GDB will now
4731 recognize the -tui command-line option and print a message that the TUI
4734 * The GDB remote stub, gdbserver, now has lower overhead for high
4735 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4737 * GDB for MIPS targets now autodetects whether a remote target provides
4738 32-bit or 64-bit register values.
4740 * Support for C++ member pointers has been improved.
4742 * GDB now understands XML target descriptions, which specify the
4743 target's overall architecture. GDB can read a description from
4744 a local file or over the remote serial protocol.
4746 * Vectors of single-byte data use a new integer type which is not
4747 automatically displayed as character or string data.
4749 * The /s format now works with the print command. It displays
4750 arrays of single-byte integers and pointers to single-byte integers
4753 * Target descriptions can now describe target-specific registers,
4754 for architectures which have implemented the support (currently
4755 only ARM, M68K, and MIPS).
4757 * GDB and the GDB remote stub, gdbserver, now support the XScale
4760 * The GDB remote stub, gdbserver, has been updated to support
4761 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4762 has been rewritten to use the standard GDB remote protocol.
4764 * GDB can now step into C++ functions which are called through thunks.
4766 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4768 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4769 layout. It also supports a TextSeg= and DataSeg= response when only
4770 segment base addresses (rather than offsets) are available.
4772 * The /i format now outputs any trailing branch delay slot instructions
4773 immediately following the last instruction within the count specified.
4775 * The GDB remote protocol "T" stop reply packet now supports a
4776 "library" response. Combined with the new "qXfer:libraries:read"
4777 packet, this response allows GDB to debug shared libraries on targets
4778 where the operating system manages the list of loaded libraries (e.g.
4779 Windows and SymbianOS).
4781 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4782 (DLLs) on Windows and Windows CE targets.
4784 * GDB now supports a faster verification that a .debug file matches its binary
4785 according to its build-id signature, if the signature is present.
4791 Enable or disable hardware flow control (RTS/CTS) on the serial port
4792 when debugging using remote targets.
4794 set mem inaccessible-by-default
4795 show mem inaccessible-by-default
4796 If the target supplies a memory map, for instance via the remote
4797 protocol's "qXfer:memory-map:read" packet, setting this variable
4798 prevents GDB from accessing memory outside the memory map. This
4799 is useful for targets with memory mapped registers or which react
4800 badly to accesses of unmapped address space.
4802 set breakpoint auto-hw
4803 show breakpoint auto-hw
4804 If the target supplies a memory map, for instance via the remote
4805 protocol's "qXfer:memory-map:read" packet, setting this variable
4806 lets GDB use hardware breakpoints automatically for memory regions
4807 where it can not use software breakpoints. This covers both the
4808 "break" command and internal breakpoints used for other commands
4809 including "next" and "finish".
4812 catch exception unhandled
4813 Stop the program execution when Ada exceptions are raised.
4816 Stop the program execution when an Ada assertion failed.
4820 Set an alternate system root for target files. This is a more
4821 general version of "set solib-absolute-prefix", which is now
4822 an alias to "set sysroot".
4825 Provide extended SPU facility status information. This set of
4826 commands is available only when debugging the Cell/B.E. SPU
4829 * New native configurations
4831 OpenBSD/sh sh*-*openbsd*
4834 unset tdesc filename
4836 Use the specified local file as an XML target description, and do
4837 not query the target for its built-in description.
4841 OpenBSD/sh sh*-*-openbsd*
4842 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4843 Toshiba Media Processor mep-elf
4845 * New remote packets
4848 Ignore the specified signals; pass them directly to the debugged program
4849 without stopping other threads or reporting them to GDB.
4851 qXfer:features:read:
4852 Read an XML target description from the target, which describes its
4857 Read or write contents of an spufs file on the target system. These
4858 packets are available only on the Cell/B.E. SPU architecture.
4860 qXfer:libraries:read:
4861 Report the loaded shared libraries. Combined with new "T" packet
4862 response, this packet allows GDB to debug shared libraries on
4863 targets where the operating system manages the list of loaded
4864 libraries (e.g. Windows and SymbianOS).
4868 Support for these obsolete configurations has been removed.
4876 i[34567]86-*-lynxos*
4877 i[34567]86-*-netware*
4878 i[34567]86-*-sco3.2v5*
4879 i[34567]86-*-sco3.2v4*
4881 i[34567]86-*-sysv4.2*
4884 i[34567]86-*-unixware2*
4885 i[34567]86-*-unixware*
4894 * Other removed features
4901 Various m68k-only ROM monitors.
4908 Various Renesas ROM monitors and debugging interfaces for SH and
4913 Support for a Macraigor serial interface to on-chip debugging.
4914 GDB does not directly support the newer parallel or USB
4919 A debug information format. The predecessor to DWARF 2 and
4920 DWARF 3, which are still supported.
4922 Support for the HP aCC compiler on HP-UX/PA-RISC
4924 SOM-encapsulated symbolic debugging information, automatic
4925 invocation of pxdb, and the aCC custom C++ ABI. This does not
4926 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4927 with aCC can still be debugged on an assembly level.
4929 MIPS ".pdr" sections
4931 A MIPS-specific format used to describe stack frame layout
4932 in debugging information.
4936 GDB could work with an older version of Guile to debug
4937 the interpreter and Scheme programs running in it.
4939 set mips stack-arg-size
4940 set mips saved-gpreg-size
4942 Use "set mips abi" to control parameter passing for MIPS.
4944 *** Changes in GDB 6.6
4949 Cell Broadband Engine SPU spu-elf
4951 * GDB can now be configured as a cross-debugger targeting native Windows
4952 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4953 running on a Windows system over TCP/IP to debug Windows programs.
4955 * The GDB remote stub, gdbserver, has been updated to support Windows and
4956 Cygwin debugging. Both single-threaded and multi-threaded programs are
4959 * The "set trust-readonly-sections" command works again. This command was
4960 broken in GDB 6.3, 6.4, and 6.5.
4962 * The "load" command now supports writing to flash memory, if the remote
4963 stub provides the required support.
4965 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4966 longer requires symbolic debug information (e.g. DWARF-2).
4971 unset substitute-path
4972 show substitute-path
4973 Manage a list of substitution rules that GDB uses to rewrite the name
4974 of the directories where the sources are located. This can be useful
4975 for instance when the sources were moved to a different location
4976 between compilation and debugging.
4980 Print each CLI command as it is executed. Each command is prefixed with
4981 a number of `+' symbols representing the nesting depth.
4982 The source command now has a `-v' option to enable the same feature.
4986 The ARM Demon monitor support (RDP protocol, "target rdp").
4988 Kernel Object Display, an embedded debugging feature which only worked with
4989 an obsolete version of Cisco IOS.
4991 The 'set download-write-size' and 'show download-write-size' commands.
4993 * New remote packets
4996 Tell a stub about GDB client features, and request remote target features.
4997 The first feature implemented is PacketSize, which allows the target to
4998 specify the size of packets it can handle - to minimize the number of
4999 packets required and improve performance when connected to a remote
5003 Fetch an OS auxilliary vector from the remote stub. This packet is a
5004 more efficient replacement for qPart:auxv:read.
5006 qXfer:memory-map:read:
5007 Fetch a memory map from the remote stub, including information about
5008 RAM, ROM, and flash memory devices.
5013 Erase and program a flash memory device.
5015 * Removed remote packets
5018 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5019 used it, and only gdbserver implemented it.
5021 *** Changes in GDB 6.5
5025 Renesas M32C/M16C m32c-elf
5027 Morpho Technologies ms1 ms1-elf
5031 init-if-undefined Initialize a convenience variable, but
5032 only if it doesn't already have a value.
5034 The following commands are presently only implemented for native GNU/Linux:
5036 checkpoint Save a snapshot of the program state.
5038 restart <n> Return the program state to a
5039 previously saved state.
5041 info checkpoints List currently saved checkpoints.
5043 delete-checkpoint <n> Delete a previously saved checkpoint.
5045 set|show detach-on-fork Tell gdb whether to detach from a newly
5046 forked process, or to keep debugging it.
5048 info forks List forks of the user program that
5049 are available to be debugged.
5051 fork <n> Switch to debugging one of several
5052 forks of the user program that are
5053 available to be debugged.
5055 delete-fork <n> Delete a fork from the list of forks
5056 that are available to be debugged (and
5057 kill the forked process).
5059 detach-fork <n> Delete a fork from the list of forks
5060 that are available to be debugged (and
5061 allow the process to continue).
5065 Morpho Technologies ms2 ms1-elf
5067 * Improved Windows host support
5069 GDB now builds as a cross debugger hosted on i686-mingw32, including
5070 native console support, and remote communications using either
5071 network sockets or serial ports.
5073 * Improved Modula-2 language support
5075 GDB can now print most types in the Modula-2 syntax. This includes:
5076 basic types, set types, record types, enumerated types, range types,
5077 pointer types and ARRAY types. Procedure var parameters are correctly
5078 printed and hexadecimal addresses and character constants are also
5079 written in the Modula-2 syntax. Best results can be obtained by using
5080 GNU Modula-2 together with the -gdwarf-2 command line option.
5084 The ARM rdi-share module.
5086 The Netware NLM debug server.
5088 *** Changes in GDB 6.4
5090 * New native configurations
5092 OpenBSD/arm arm*-*-openbsd*
5093 OpenBSD/mips64 mips64-*-openbsd*
5097 Morpho Technologies ms1 ms1-elf
5099 * New command line options
5101 --batch-silent As for --batch, but totally silent.
5102 --return-child-result The debugger will exist with the same value
5103 the child (debugged) program exited with.
5104 --eval-command COMMAND, -ex COMMAND
5105 Execute a single GDB CLI command. This may be
5106 specified multiple times and in conjunction
5107 with the --command (-x) option.
5109 * Deprecated commands removed
5111 The following commands, that were deprecated in 2000, have been
5115 set|show arm disassembly-flavor set|show arm disassembler
5116 othernames set arm disassembler
5117 set|show remotedebug set|show debug remote
5118 set|show archdebug set|show debug arch
5119 set|show eventdebug set|show debug event
5122 * New BSD user-level threads support
5124 It is now possible to debug programs using the user-level threads
5125 library on OpenBSD and FreeBSD. Currently supported (target)
5128 FreeBSD/amd64 x86_64-*-freebsd*
5129 FreeBSD/i386 i386-*-freebsd*
5130 OpenBSD/i386 i386-*-openbsd*
5132 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5133 are not yet supported.
5135 * New support for Matsushita MN10300 w/sim added
5136 (Work in progress). mn10300-elf.
5138 * REMOVED configurations and files
5140 VxWorks and the XDR protocol *-*-vxworks
5141 Motorola MCORE mcore-*-*
5142 National Semiconductor NS32000 ns32k-*-*
5144 * New "set print array-indexes" command
5146 After turning this setting "on", GDB prints the index of each element
5147 when displaying arrays. The default is "off" to preserve the previous
5150 * VAX floating point support
5152 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5154 * User-defined command support
5156 In addition to using $arg0..$arg9 for argument passing, it is now possible
5157 to use $argc to determine now many arguments have been passed. See the
5158 section on user-defined commands in the user manual for more information.
5160 *** Changes in GDB 6.3:
5162 * New command line option
5164 GDB now accepts -l followed by a number to set the timeout for remote
5167 * GDB works with GCC -feliminate-dwarf2-dups
5169 GDB now supports a more compact representation of DWARF-2 debug
5170 information using DW_FORM_ref_addr references. These are produced
5171 by GCC with the option -feliminate-dwarf2-dups and also by some
5172 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5173 to use -feliminate-dwarf2-dups.
5175 * Internationalization
5177 When supported by the host system, GDB will be built with
5178 internationalization (libintl). The task of marking up the sources is
5179 continued, we're looking forward to our first translation.
5183 Initial support for debugging programs compiled with the GNAT
5184 implementation of the Ada programming language has been integrated
5185 into GDB. In this release, support is limited to expression evaluation.
5187 * New native configurations
5189 GNU/Linux/m32r m32r-*-linux-gnu
5193 GDB's remote protocol now includes support for the 'p' packet. This
5194 packet is used to fetch individual registers from a remote inferior.
5196 * END-OF-LIFE registers[] compatibility module
5198 GDB's internal register infrastructure has been completely rewritten.
5199 The new infrastructure making possible the implementation of key new
5200 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5203 GDB 6.3 will be the last release to include the the registers[]
5204 compatibility module that allowed out-of-date configurations to
5205 continue to work. This change directly impacts the following
5215 powerpc bdm protocol
5217 Unless there is activity to revive these configurations, they will be
5218 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5220 * OBSOLETE configurations and files
5222 Configurations that have been declared obsolete in this release have
5223 been commented out. Unless there is activity to revive these
5224 configurations, the next release of GDB will have their sources
5225 permanently REMOVED.
5234 *** Changes in GDB 6.2.1:
5236 * MIPS `break main; run' gave an heuristic-fence-post warning
5238 When attempting to run even a simple program, a warning about
5239 heuristic-fence-post being hit would be reported. This problem has
5242 * MIPS IRIX 'long double' crashed GDB
5244 When examining a long double variable, GDB would get a segmentation
5245 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5246 IRIX long double values).
5250 A bug in the VAX stack code was causing problems with the "next"
5251 command. This problem has been fixed.
5253 *** Changes in GDB 6.2:
5255 * Fix for ``many threads''
5257 On GNU/Linux systems that use the NPTL threads library, a program
5258 rapidly creating and deleting threads would confuse GDB leading to the
5261 ptrace: No such process.
5262 thread_db_get_info: cannot get thread info: generic error
5264 This problem has been fixed.
5266 * "-async" and "-noasync" options removed.
5268 Support for the broken "-noasync" option has been removed (it caused
5271 * New ``start'' command.
5273 This command runs the program until the begining of the main procedure.
5275 * New BSD Kernel Data Access Library (libkvm) interface
5277 Using ``target kvm'' it is now possible to debug kernel core dumps and
5278 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5279 platforms. Currently supported (native-only) configurations are:
5281 FreeBSD/amd64 x86_64-*-freebsd*
5282 FreeBSD/i386 i?86-*-freebsd*
5283 NetBSD/i386 i?86-*-netbsd*
5284 NetBSD/m68k m68*-*-netbsd*
5285 NetBSD/sparc sparc-*-netbsd*
5286 OpenBSD/amd64 x86_64-*-openbsd*
5287 OpenBSD/i386 i?86-*-openbsd*
5288 OpenBSD/m68k m68*-openbsd*
5289 OpenBSD/sparc sparc-*-openbsd*
5291 * Signal trampoline code overhauled
5293 Many generic problems with GDB's signal handling code have been fixed.
5294 These include: backtraces through non-contiguous stacks; recognition
5295 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5296 call; backtrace through a signal trampoline; step into and out of
5297 signal handlers; and single-stepping in the signal trampoline.
5299 Please note that kernel bugs are a limiting factor here. These
5300 features have been shown to work on an s390 GNU/Linux system that
5301 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5303 * Cygwin support for DWARF 2 added.
5305 * New native configurations
5307 GNU/Linux/hppa hppa*-*-linux*
5308 OpenBSD/hppa hppa*-*-openbsd*
5309 OpenBSD/m68k m68*-*-openbsd*
5310 OpenBSD/m88k m88*-*-openbsd*
5311 OpenBSD/powerpc powerpc-*-openbsd*
5312 NetBSD/vax vax-*-netbsd*
5313 OpenBSD/vax vax-*-openbsd*
5315 * END-OF-LIFE frame compatibility module
5317 GDB's internal frame infrastructure has been completely rewritten.
5318 The new infrastructure making it possible to support key new features
5319 including DWARF 2 Call Frame Information. To aid in the task of
5320 migrating old configurations to this new infrastructure, a
5321 compatibility module, that allowed old configurations to continue to
5322 work, was also included.
5324 GDB 6.2 will be the last release to include this frame compatibility
5325 module. This change directly impacts the following configurations:
5335 Unless there is activity to revive these configurations, they will be
5336 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5338 * REMOVED configurations and files
5340 Sun 3, running SunOS 3 m68*-*-sunos3*
5341 Sun 3, running SunOS 4 m68*-*-sunos4*
5342 Sun 2, running SunOS 3 m68000-*-sunos3*
5343 Sun 2, running SunOS 4 m68000-*-sunos4*
5344 Motorola 680x0 running LynxOS m68*-*-lynxos*
5345 AT&T 3b1/Unix pc m68*-att-*
5346 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5347 decstation mips-dec-* mips-little-*
5348 riscos mips-*-riscos* mips-*-sysv*
5349 sonymips mips-sony-*
5350 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5352 *** Changes in GDB 6.1.1:
5354 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5356 The TUI (Text-mode User Interface) is now built as part of a default
5357 GDB configuration. It is enabled by either selecting the TUI with the
5358 command line option "-i=tui" or by running the separate "gdbtui"
5359 program. For more information on the TUI, see the manual "Debugging
5362 * Pending breakpoint support (also included in GDB 6.1)
5364 Support has been added to allow you to specify breakpoints in shared
5365 libraries that have not yet been loaded. If a breakpoint location
5366 cannot be found, and the "breakpoint pending" option is set to auto,
5367 GDB queries you if you wish to make the breakpoint pending on a future
5368 shared-library load. If and when GDB resolves the breakpoint symbol,
5369 the pending breakpoint is removed as one or more regular breakpoints
5372 Pending breakpoints are very useful for GCJ Java debugging.
5374 * Fixed ISO-C build problems
5376 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5377 non ISO-C code that stopped them being built using a more strict ISO-C
5378 compiler (e.g., IBM's C compiler).
5380 * Fixed build problem on IRIX 5
5382 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5383 wasn't able to compile compile on an IRIX 5 system.
5385 * Added execute permission to gdb/gdbserver/configure
5387 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5388 permission. This bug would cause configure to fail on a number of
5389 systems (Solaris, IRIX). Ref: server/519.
5391 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5393 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5394 has been updated to use constant array sizes.
5396 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5398 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5399 its generated DWARF Call Frame Info. This encoding was causing GDB to
5400 panic, that panic has been fixed. Ref: gdb/1628.
5402 * Fixed a problem when examining parameters in shared library code.
5404 When examining parameters in optimized shared library code generated
5405 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5406 not available''. GDB now correctly displays the variable's value.
5408 *** Changes in GDB 6.1:
5410 * Removed --with-mmalloc
5412 Support for the mmalloc memory manager has been removed, as it
5413 conflicted with the internal gdb byte cache.
5415 * Changes in AMD64 configurations
5417 The AMD64 target now includes the %cs and %ss registers. As a result
5418 the AMD64 remote protocol has changed; this affects the floating-point
5419 and SSE registers. If you rely on those registers for your debugging,
5420 you should upgrade gdbserver on the remote side.
5422 * Revised SPARC target
5424 The SPARC target has been completely revised, incorporating the
5425 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5426 support for LynxOS and SunOS 4 has been dropped. Calling functions
5427 from within GDB on operating systems with a non-executable stack
5428 (Solaris, OpenBSD) now works.
5432 GDB has a new C++ demangler which does a better job on the mangled
5433 names generated by current versions of g++. It also runs faster, so
5434 with this and other changes gdb should now start faster on large C++
5437 * DWARF 2 Location Expressions
5439 GDB support for location expressions has been extended to support function
5440 arguments and frame bases. Older versions of GDB could crash when they
5443 * C++ nested types and namespaces
5445 GDB's support for nested types and namespaces in C++ has been
5446 improved, especially if you use the DWARF 2 debugging format. (This
5447 is the default for recent versions of GCC on most platforms.)
5448 Specifically, if you have a class "Inner" defined within a class or
5449 namespace "Outer", then GDB realizes that the class's name is
5450 "Outer::Inner", not simply "Inner". This should greatly reduce the
5451 frequency of complaints about not finding RTTI symbols. In addition,
5452 if you are stopped at inside of a function defined within a namespace,
5453 GDB modifies its name lookup accordingly.
5455 * New native configurations
5457 NetBSD/amd64 x86_64-*-netbsd*
5458 OpenBSD/amd64 x86_64-*-openbsd*
5459 OpenBSD/alpha alpha*-*-openbsd*
5460 OpenBSD/sparc sparc-*-openbsd*
5461 OpenBSD/sparc64 sparc64-*-openbsd*
5463 * New debugging protocols
5465 M32R with SDI protocol m32r-*-elf*
5467 * "set prompt-escape-char" command deleted.
5469 The command "set prompt-escape-char" has been deleted. This command,
5470 and its very obscure effet on GDB's prompt, was never documented,
5471 tested, nor mentioned in the NEWS file.
5473 * OBSOLETE configurations and files
5475 Configurations that have been declared obsolete in this release have
5476 been commented out. Unless there is activity to revive these
5477 configurations, the next release of GDB will have their sources
5478 permanently REMOVED.
5480 Sun 3, running SunOS 3 m68*-*-sunos3*
5481 Sun 3, running SunOS 4 m68*-*-sunos4*
5482 Sun 2, running SunOS 3 m68000-*-sunos3*
5483 Sun 2, running SunOS 4 m68000-*-sunos4*
5484 Motorola 680x0 running LynxOS m68*-*-lynxos*
5485 AT&T 3b1/Unix pc m68*-att-*
5486 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5487 decstation mips-dec-* mips-little-*
5488 riscos mips-*-riscos* mips-*-sysv*
5489 sonymips mips-sony-*
5490 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5492 * REMOVED configurations and files
5494 SGI Irix-4.x mips-sgi-irix4 or iris4
5495 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5496 Z8000 simulator z8k-zilog-none or z8ksim
5497 Matsushita MN10200 w/simulator mn10200-*-*
5498 H8/500 simulator h8500-hitachi-hms or h8500hms
5499 HP/PA running BSD hppa*-*-bsd*
5500 HP/PA running OSF/1 hppa*-*-osf*
5501 HP/PA Pro target hppa*-*-pro*
5502 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5503 386BSD i[3456]86-*-bsd*
5504 Sequent family i[3456]86-sequent-sysv4*
5505 i[3456]86-sequent-sysv*
5506 i[3456]86-sequent-bsd*
5507 SPARC running LynxOS sparc-*-lynxos*
5508 SPARC running SunOS 4 sparc-*-sunos4*
5509 Tsqware Sparclet sparclet-*-*
5510 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5512 *** Changes in GDB 6.0:
5516 Support for debugging the Objective-C programming language has been
5517 integrated into GDB.
5519 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5521 DWARF 2's Call Frame Information makes available compiler generated
5522 information that more exactly describes the program's run-time stack.
5523 By using this information, GDB is able to provide more robust stack
5526 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5527 have been updated to use a new backtrace mechanism which includes
5528 DWARF 2 CFI support.
5532 GDB's remote protocol has been extended to include support for hosted
5533 file I/O (where the remote target uses GDB's file system). See GDB's
5534 remote protocol documentation for details.
5536 * All targets using the new architecture framework.
5538 All of GDB's targets have been updated to use the new internal
5539 architecture framework. The way is now open for future GDB releases
5540 to include cross-architecture native debugging support (i386 on amd64,
5543 * GNU/Linux's Thread Local Storage (TLS)
5545 GDB now includes support for for the GNU/Linux implementation of
5546 per-thread variables.
5548 * GNU/Linux's Native POSIX Thread Library (NPTL)
5550 GDB's thread code has been updated to work with either the new
5551 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5553 * Separate debug info.
5555 GDB, in conjunction with BINUTILS, now supports a mechanism for
5556 automatically loading debug information from a separate file. Instead
5557 of shipping full debug and non-debug versions of system libraries,
5558 system integrators can now instead ship just the stripped libraries
5559 and optional debug files.
5561 * DWARF 2 Location Expressions
5563 DWARF 2 Location Expressions allow the compiler to more completely
5564 describe the location of variables (even in optimized code) to the
5567 GDB now includes preliminary support for location expressions (support
5568 for DW_OP_piece is still missing).
5572 A number of long standing bugs that caused GDB to die while starting a
5573 Java application have been fixed. GDB's Java support is now
5574 considered "useable".
5576 * GNU/Linux support for fork, vfork, and exec.
5578 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5579 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5582 * GDB supports logging output to a file
5584 There are two new commands, "set logging" and "show logging", which can be
5585 used to capture GDB's output to a file.
5587 * The meaning of "detach" has changed for gdbserver
5589 The "detach" command will now resume the application, as documented. To
5590 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5593 * d10v, m68hc11 `regs' command deprecated
5595 The `info registers' command has been updated so that it displays the
5596 registers using a format identical to the old `regs' command.
5600 A new command, "maint set profile on/off", has been added. This command can
5601 be used to enable or disable profiling while running GDB, to profile a
5602 session or a set of commands. In addition there is a new configure switch,
5603 "--enable-profiling", which will cause GDB to be compiled with profiling
5604 data, for more informative profiling results.
5606 * Default MI syntax changed to "mi2".
5608 The default MI (machine interface) syntax, enabled by the command line
5609 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5610 "mi1", can be enabled by specifying the option "-i=mi1".
5612 Support for the original "mi0" syntax (included in GDB 5.0) has been
5615 Fix for gdb/192: removed extraneous space when displaying frame level.
5616 Fix for gdb/672: update changelist is now output in mi list format.
5617 Fix for gdb/702: a -var-assign that updates the value now shows up
5618 in a subsequent -var-update.
5620 * New native configurations.
5622 FreeBSD/amd64 x86_64-*-freebsd*
5624 * Multi-arched targets.
5626 HP/PA HPUX11 hppa*-*-hpux*
5627 Renesas M32R/D w/simulator m32r-*-elf*
5629 * OBSOLETE configurations and files
5631 Configurations that have been declared obsolete in this release have
5632 been commented out. Unless there is activity to revive these
5633 configurations, the next release of GDB will have their sources
5634 permanently REMOVED.
5636 Z8000 simulator z8k-zilog-none or z8ksim
5637 Matsushita MN10200 w/simulator mn10200-*-*
5638 H8/500 simulator h8500-hitachi-hms or h8500hms
5639 HP/PA running BSD hppa*-*-bsd*
5640 HP/PA running OSF/1 hppa*-*-osf*
5641 HP/PA Pro target hppa*-*-pro*
5642 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5643 Sequent family i[3456]86-sequent-sysv4*
5644 i[3456]86-sequent-sysv*
5645 i[3456]86-sequent-bsd*
5646 Tsqware Sparclet sparclet-*-*
5647 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5649 * REMOVED configurations and files
5652 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5653 IBM AIX PS/2 i[3456]86-*-aix
5654 i386 running Mach 3.0 i[3456]86-*-mach3*
5655 i386 running Mach i[3456]86-*-mach*
5656 i386 running OSF/1 i[3456]86-*osf1mk*
5657 HP/Apollo 68k Family m68*-apollo*-sysv*,
5659 m68*-hp-bsd*, m68*-hp-hpux*
5660 Argonaut Risc Chip (ARC) arc-*-*
5661 Mitsubishi D30V d30v-*-*
5662 Fujitsu FR30 fr30-*-elf*
5663 OS/9000 i[34]86-*-os9k
5664 I960 with MON960 i960-*-coff
5666 * MIPS $fp behavior changed
5668 The convenience variable $fp, for the MIPS, now consistently returns
5669 the address of the current frame's base. Previously, depending on the
5670 context, $fp could refer to either $sp or the current frame's base
5671 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5672 The GNU Source-Level Debugger''.
5674 *** Changes in GDB 5.3:
5676 * GNU/Linux shared library multi-threaded performance improved.
5678 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5679 `/proc', in preference to `ptrace' for memory reads. This may result
5680 in an improvement in the start-up time of multi-threaded, shared
5681 library applications when run under GDB. One GDB user writes: ``loads
5682 shared libs like mad''.
5684 * ``gdbserver'' now supports multi-threaded applications on some targets
5686 Support for debugging multi-threaded applications which use
5687 the GNU/Linux LinuxThreads package has been added for
5688 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5689 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5691 * GDB now supports C/C++ preprocessor macros.
5693 GDB now expands preprocessor macro invocations in C/C++ expressions,
5694 and provides various commands for showing macro definitions and how
5697 The new command `macro expand EXPRESSION' expands any macro
5698 invocations in expression, and shows the result.
5700 The new command `show macro MACRO-NAME' shows the definition of the
5701 macro named MACRO-NAME, and where it was defined.
5703 Most compilers don't include information about macros in the debugging
5704 information by default. In GCC 3.1, for example, you need to compile
5705 your program with the options `-gdwarf-2 -g3'. If the macro
5706 information is present in the executable, GDB will read it.
5708 * Multi-arched targets.
5710 DEC Alpha (partial) alpha*-*-*
5711 DEC VAX (partial) vax-*-*
5713 National Semiconductor NS32000 (partial) ns32k-*-*
5714 Motorola 68000 (partial) m68k-*-*
5715 Motorola MCORE mcore-*-*
5719 Fujitsu FRV architecture added by Red Hat frv*-*-*
5722 * New native configurations
5724 Alpha NetBSD alpha*-*-netbsd*
5725 SH NetBSD sh*-*-netbsdelf*
5726 MIPS NetBSD mips*-*-netbsd*
5727 UltraSPARC NetBSD sparc64-*-netbsd*
5729 * OBSOLETE configurations and files
5731 Configurations that have been declared obsolete in this release have
5732 been commented out. Unless there is activity to revive these
5733 configurations, the next release of GDB will have their sources
5734 permanently REMOVED.
5736 Mitsubishi D30V d30v-*-*
5737 OS/9000 i[34]86-*-os9k
5738 IBM AIX PS/2 i[3456]86-*-aix
5739 Fujitsu FR30 fr30-*-elf*
5740 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5741 Argonaut Risc Chip (ARC) arc-*-*
5742 i386 running Mach 3.0 i[3456]86-*-mach3*
5743 i386 running Mach i[3456]86-*-mach*
5744 i386 running OSF/1 i[3456]86-*osf1mk*
5745 HP/Apollo 68k Family m68*-apollo*-sysv*,
5747 m68*-hp-bsd*, m68*-hp-hpux*
5748 I960 with MON960 i960-*-coff
5750 * OBSOLETE languages
5752 CHILL, a Pascal like language used by telecommunications companies.
5754 * REMOVED configurations and files
5756 AMD 29k family via UDI a29k-amd-udi, udi29k
5757 A29K VxWorks a29k-*-vxworks
5758 AMD 29000 embedded, using EBMON a29k-none-none
5759 AMD 29000 embedded with COFF a29k-none-coff
5760 AMD 29000 embedded with a.out a29k-none-aout
5762 testsuite/gdb.hp/gdb.threads-hp/ directory
5764 * New command "set max-user-call-depth <nnn>"
5766 This command allows the user to limit the call depth of user-defined
5767 commands. The default is 1024.
5769 * Changes in FreeBSD/i386 native debugging.
5771 Support for the "generate-core-file" has been added.
5773 * New commands "dump", "append", and "restore".
5775 These commands allow data to be copied from target memory
5776 to a bfd-format or binary file (dump and append), and back
5777 from a file into memory (restore).
5779 * Improved "next/step" support on multi-processor Alpha Tru64.
5781 The previous single-step mechanism could cause unpredictable problems,
5782 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5783 of a software single-step mechanism prevents this.
5785 *** Changes in GDB 5.2.1:
5793 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5794 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5795 Fix, by Joel Brobecker imported from mainline.
5797 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5798 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5799 Fix, by Fred Fish, imported from mainline.
5801 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5802 Surprisingly enough, it works now.
5803 By Michal Ludvig, imported from mainline.
5805 i386 hardware watchpoint support:
5806 avoid misses on second run for some targets.
5807 By Pierre Muller, imported from mainline.
5809 *** Changes in GDB 5.2:
5811 * New command "set trust-readonly-sections on[off]".
5813 This command is a hint that tells gdb that read-only sections
5814 really are read-only (ie. that their contents will not change).
5815 In this mode, gdb will go to the object file rather than the
5816 target to read memory from read-only sections (such as ".text").
5817 This can be a significant performance improvement on some
5818 (notably embedded) targets.
5820 * New command "generate-core-file" (or "gcore").
5822 This new gdb command allows the user to drop a core file of the child
5823 process state at any time. So far it's been implemented only for
5824 GNU/Linux and Solaris, but should be relatively easily ported to other
5825 hosts. Argument is core file name (defaults to core.<pid>).
5827 * New command line option
5829 GDB now accepts --pid or -p followed by a process id.
5831 * Change in command line behavior -- corefiles vs. process ids.
5833 There is a subtle behavior in the way in which GDB handles
5834 command line arguments. The first non-flag argument is always
5835 a program to debug, but the second non-flag argument may either
5836 be a corefile or a process id. Previously, GDB would attempt to
5837 open the second argument as a corefile, and if that failed, would
5838 issue a superfluous error message and then attempt to attach it as
5839 a process. Now, if the second argument begins with a non-digit,
5840 it will be treated as a corefile. If it begins with a digit,
5841 GDB will attempt to attach it as a process, and if no such process
5842 is found, will then attempt to open it as a corefile.
5844 * Changes in ARM configurations.
5846 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5847 configuration is fully multi-arch.
5849 * New native configurations
5851 ARM NetBSD arm*-*-netbsd*
5852 x86 OpenBSD i[3456]86-*-openbsd*
5853 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5854 Sparc64 running FreeBSD sparc64-*-freebsd*
5858 Sanyo XStormy16 xstormy16-elf
5860 * OBSOLETE configurations and files
5862 Configurations that have been declared obsolete in this release have
5863 been commented out. Unless there is activity to revive these
5864 configurations, the next release of GDB will have their sources
5865 permanently REMOVED.
5867 AMD 29k family via UDI a29k-amd-udi, udi29k
5868 A29K VxWorks a29k-*-vxworks
5869 AMD 29000 embedded, using EBMON a29k-none-none
5870 AMD 29000 embedded with COFF a29k-none-coff
5871 AMD 29000 embedded with a.out a29k-none-aout
5873 testsuite/gdb.hp/gdb.threads-hp/ directory
5875 * REMOVED configurations and files
5877 TI TMS320C80 tic80-*-*
5879 PowerPC Solaris powerpcle-*-solaris*
5880 PowerPC Windows NT powerpcle-*-cygwin32
5881 PowerPC Netware powerpc-*-netware*
5882 Harris/CXUX m88k m88*-harris-cxux*
5883 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5884 ns32k-utek-sysv* ns32k-utek-*
5885 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5886 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5887 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5888 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5889 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5891 * Changes to command line processing
5893 The new `--args' feature can be used to specify command-line arguments
5894 for the inferior from gdb's command line.
5896 * Changes to key bindings
5898 There is a new `operate-and-get-next' function bound to `C-o'.
5900 *** Changes in GDB 5.1.1
5902 Fix compile problem on DJGPP.
5904 Fix a problem with floating-point registers on the i386 being
5907 Fix to stop GDB crashing on .debug_str debug info.
5909 Numerous documentation fixes.
5911 Numerous testsuite fixes.
5913 *** Changes in GDB 5.1:
5915 * New native configurations
5917 Alpha FreeBSD alpha*-*-freebsd*
5918 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5919 MIPS GNU/Linux mips*-*-linux*
5920 MIPS SGI Irix 6.x mips*-sgi-irix6*
5921 ia64 AIX ia64-*-aix*
5922 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5926 Motorola 68HC11 and 68HC12 m68hc11-elf
5928 UltraSparc running GNU/Linux sparc64-*-linux*
5930 * OBSOLETE configurations and files
5932 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5933 Harris/CXUX m88k m88*-harris-cxux*
5934 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5935 ns32k-utek-sysv* ns32k-utek-*
5936 TI TMS320C80 tic80-*-*
5938 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5939 PowerPC Solaris powerpcle-*-solaris*
5940 PowerPC Windows NT powerpcle-*-cygwin32
5941 PowerPC Netware powerpc-*-netware*
5942 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5943 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5944 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5945 Apple Macintosh (MPW) host N/A
5947 stuff.c (Program to stuff files into a specially prepared space in kdb)
5948 kdb-start.c (Main loop for the standalone kernel debugger)
5950 Configurations that have been declared obsolete in this release have
5951 been commented out. Unless there is activity to revive these
5952 configurations, the next release of GDB will have their sources
5953 permanently REMOVED.
5955 * REMOVED configurations and files
5957 Altos 3068 m68*-altos-*
5958 Convex c1-*-*, c2-*-*
5960 ARM RISCix arm-*-* (as host)
5964 * GDB has been converted to ISO C.
5966 GDB's source code has been converted to ISO C. In particular, the
5967 sources are fully protoized, and rely on standard headers being
5972 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5974 * The MI enabled by default.
5976 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5977 revised and enabled by default. Packages which use GDB as a debugging
5978 engine behind a UI or another front end are encouraged to switch to
5979 using the GDB/MI interface, instead of the old annotations interface
5980 which is now deprecated.
5982 * Support for debugging Pascal programs.
5984 GDB now includes support for debugging Pascal programs. The following
5985 main features are supported:
5987 - Pascal-specific data types such as sets;
5989 - automatic recognition of Pascal sources based on file-name
5992 - Pascal-style display of data types, variables, and functions;
5994 - a Pascal expression parser.
5996 However, some important features are not yet supported.
5998 - Pascal string operations are not supported at all;
6000 - there are some problems with boolean types;
6002 - Pascal type hexadecimal constants are not supported
6003 because they conflict with the internal variables format;
6005 - support for Pascal objects and classes is not full yet;
6007 - unlike Pascal, GDB is case-sensitive for symbol names.
6009 * Changes in completion.
6011 Commands such as `shell', `run' and `set args', which pass arguments
6012 to inferior programs, now complete on file names, similar to what
6013 users expect at the shell prompt.
6015 Commands which accept locations, such as `disassemble', `print',
6016 `breakpoint', `until', etc. now complete on filenames as well as
6017 program symbols. Thus, if you type "break foob TAB", and the source
6018 files linked into the programs include `foobar.c', that file name will
6019 be one of the candidates for completion. However, file names are not
6020 considered for completion after you typed a colon that delimits a file
6021 name from a name of a function in that file, as in "break foo.c:bar".
6023 `set demangle-style' completes on available demangling styles.
6025 * New platform-independent commands:
6027 It is now possible to define a post-hook for a command as well as a
6028 hook that runs before the command. For more details, see the
6029 documentation of `hookpost' in the GDB manual.
6031 * Changes in GNU/Linux native debugging.
6033 Support for debugging multi-threaded programs has been completely
6034 revised for all platforms except m68k and sparc. You can now debug as
6035 many threads as your system allows you to have.
6037 Attach/detach is supported for multi-threaded programs.
6039 Support for SSE registers was added for x86. This doesn't work for
6040 multi-threaded programs though.
6042 * Changes in MIPS configurations.
6044 Multi-arch support is enabled for all MIPS configurations.
6046 GDB can now be built as native debugger on SGI Irix 6.x systems for
6047 debugging n32 executables. (Debugging 64-bit executables is not yet
6050 * Unified support for hardware watchpoints in all x86 configurations.
6052 Most (if not all) native x86 configurations support hardware-assisted
6053 breakpoints and watchpoints in a unified manner. This support
6054 implements debug register sharing between watchpoints, which allows to
6055 put a virtually infinite number of watchpoints on the same address,
6056 and also supports watching regions up to 16 bytes with several debug
6059 The new maintenance command `maintenance show-debug-regs' toggles
6060 debugging print-outs in functions that insert, remove, and test
6061 watchpoints and hardware breakpoints.
6063 * Changes in the DJGPP native configuration.
6065 New command ``info dos sysinfo'' displays assorted information about
6066 the CPU, OS, memory, and DPMI server.
6068 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6069 display information about segment descriptors stored in GDT, LDT, and
6072 New commands ``info dos pde'' and ``info dos pte'' display entries
6073 from Page Directory and Page Tables (for now works with CWSDPMI only).
6074 New command ``info dos address-pte'' displays the Page Table entry for
6075 a given linear address.
6077 GDB can now pass command lines longer than 126 characters to the
6078 program being debugged (requires an update to the libdbg.a library
6079 which is part of the DJGPP development kit).
6081 DWARF2 debug info is now supported.
6083 It is now possible to `step' and `next' through calls to `longjmp'.
6085 * Changes in documentation.
6087 All GDB documentation was converted to GFDL, the GNU Free
6088 Documentation License.
6090 Tracepoints-related commands are now fully documented in the GDB
6093 TUI, the Text-mode User Interface, is now documented in the manual.
6095 Tracepoints-related commands are now fully documented in the GDB
6098 The "GDB Internals" manual now has an index. It also includes
6099 documentation of `ui_out' functions, GDB coding standards, x86
6100 hardware watchpoints, and memory region attributes.
6102 * GDB's version number moved to ``version.in''
6104 The Makefile variable VERSION has been replaced by the file
6105 ``version.in''. People creating GDB distributions should update the
6106 contents of this file.
6110 GUD support is now a standard part of the EMACS distribution.
6112 *** Changes in GDB 5.0:
6114 * Improved support for debugging FP programs on x86 targets
6116 Unified and much-improved support for debugging floating-point
6117 programs on all x86 targets. In particular, ``info float'' now
6118 displays the FP registers in the same format on all x86 targets, with
6119 greater level of detail.
6121 * Improvements and bugfixes in hardware-assisted watchpoints
6123 It is now possible to watch array elements, struct members, and
6124 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6125 on x86 targets no longer erroneously trigger when the address is
6128 * Improvements in the native DJGPP version of GDB
6130 The distribution now includes all the scripts and auxiliary files
6131 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6132 machines ``out of the box''.
6134 The DJGPP version can now debug programs that use signals. It is
6135 possible to catch signals that happened in the debuggee, deliver
6136 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6137 would kill the program being debugged.) Programs that hook hardware
6138 interrupts (keyboard, timer, etc.) can also be debugged.
6140 It is now possible to debug DJGPP programs that redirect their
6141 standard handles or switch them to raw (as opposed to cooked) mode, or
6142 even close them. The command ``run < foo > bar'' works as expected,
6143 and ``info terminal'' reports useful information about the debuggee's
6144 terminal, including raw/cooked mode, redirection, etc.
6146 The DJGPP version now uses termios functions for console I/O, which
6147 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6150 DOS-style file names with drive letters are now fully supported by
6153 It is now possible to debug DJGPP programs that switch their working
6154 directory. It is also possible to rerun the debuggee any number of
6155 times without restarting GDB; thus, you can use the same setup,
6156 breakpoints, etc. for many debugging sessions.
6158 * New native configurations
6160 ARM GNU/Linux arm*-*-linux*
6161 PowerPC GNU/Linux powerpc-*-linux*
6165 Motorola MCore mcore-*-*
6166 x86 VxWorks i[3456]86-*-vxworks*
6167 PowerPC VxWorks powerpc-*-vxworks*
6168 TI TMS320C80 tic80-*-*
6170 * OBSOLETE configurations
6172 Altos 3068 m68*-altos-*
6173 Convex c1-*-*, c2-*-*
6175 ARM RISCix arm-*-* (as host)
6178 Configurations that have been declared obsolete will be commented out,
6179 but the code will be left in place. If there is no activity to revive
6180 these configurations before the next release of GDB, the sources will
6181 be permanently REMOVED.
6183 * Gould support removed
6185 Support for the Gould PowerNode and NP1 has been removed.
6187 * New features for SVR4
6189 On SVR4 native platforms (such as Solaris), if you attach to a process
6190 without first loading a symbol file, GDB will now attempt to locate and
6191 load symbols from the running process's executable file.
6193 * Many C++ enhancements
6195 C++ support has been greatly improved. Overload resolution now works properly
6196 in almost all cases. RTTI support is on the way.
6198 * Remote targets can connect to a sub-program
6200 A popen(3) style serial-device has been added. This device starts a
6201 sub-process (such as a stand-alone simulator) and then communicates
6202 with that. The sub-program to run is specified using the syntax
6203 ``|<program> <args>'' vis:
6205 (gdb) set remotedebug 1
6206 (gdb) target extended-remote |mn10300-elf-sim program-args
6208 * MIPS 64 remote protocol
6210 A long standing bug in the mips64 remote protocol where by GDB
6211 expected certain 32 bit registers (ex SR) to be transfered as 32
6212 instead of 64 bits has been fixed.
6214 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6215 added to provide backward compatibility with older versions of GDB.
6217 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6219 The command ``set remotebinarydownload'' command has been replaced by
6220 ``set remote X-packet''. Other commands in ``set remote'' family
6221 include ``set remote P-packet''.
6223 * Breakpoint commands accept ranges.
6225 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6226 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6227 ``tracepoint passcount'' also accepts a range of tracepoints.
6229 * ``apropos'' command added.
6231 The ``apropos'' command searches through command names and
6232 documentation strings, printing out matches, making it much easier to
6233 try to find a command that does what you are looking for.
6237 A new machine oriented interface (MI) has been added to GDB. This
6238 interface is designed for debug environments running GDB as a separate
6239 process. This is part of the long term libGDB project. See the
6240 "GDB/MI" chapter of the GDB manual for further information. It can be
6241 enabled by configuring with:
6243 .../configure --enable-gdbmi
6245 *** Changes in GDB-4.18:
6247 * New native configurations
6249 HP-UX 10.20 hppa*-*-hpux10.20
6250 HP-UX 11.x hppa*-*-hpux11.0*
6251 M68K GNU/Linux m68*-*-linux*
6255 Fujitsu FR30 fr30-*-elf*
6256 Intel StrongARM strongarm-*-*
6257 Mitsubishi D30V d30v-*-*
6259 * OBSOLETE configurations
6261 Gould PowerNode, NP1 np1-*-*, pn-*-*
6263 Configurations that have been declared obsolete will be commented out,
6264 but the code will be left in place. If there is no activity to revive
6265 these configurations before the next release of GDB, the sources will
6266 be permanently REMOVED.
6270 As a compatibility experiment, GDB's source files buildsym.h and
6271 buildsym.c have been converted to pure standard C, no longer
6272 containing any K&R compatibility code. We believe that all systems in
6273 use today either come with a standard C compiler, or have a GCC port
6274 available. If this is not true, please report the affected
6275 configuration to bug-gdb@gnu.org immediately. See the README file for
6276 information about getting a standard C compiler if you don't have one
6281 GDB now uses readline 2.2.
6283 * set extension-language
6285 You can now control the mapping between filename extensions and source
6286 languages by using the `set extension-language' command. For instance,
6287 you can ask GDB to treat .c files as C++ by saying
6288 set extension-language .c c++
6289 The command `info extensions' lists all of the recognized extensions
6290 and their associated languages.
6292 * Setting processor type for PowerPC and RS/6000
6294 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6295 you can use the `set processor' command to specify what variant of the
6296 PowerPC family you are debugging. The command
6300 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6301 following PowerPC and RS6000 variants:
6303 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6304 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6306 403GC IBM PowerPC 403GC
6307 505 Motorola PowerPC 505
6308 860 Motorola PowerPC 860 or 850
6309 601 Motorola PowerPC 601
6310 602 Motorola PowerPC 602
6311 603 Motorola/IBM PowerPC 603 or 603e
6312 604 Motorola PowerPC 604 or 604e
6313 750 Motorola/IBM PowerPC 750 or 750
6315 At the moment, this command just tells GDB what to name the
6316 special-purpose processor registers. Since almost all the affected
6317 registers are inaccessible to user-level programs, this command is
6318 only useful for remote debugging in its present form.
6322 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6323 more extensive support for HP-UX. Added features include shared
6324 library support, kernel threads and hardware watchpoints for 11.00,
6325 support for HP's ANSI C and C++ compilers, and a compatibility mode
6326 for xdb and dbx commands.
6330 HP's donation includes the new concept of catchpoints, which is a
6331 generalization of the old catch command. On HP-UX, it is now possible
6332 to catch exec, fork, and vfork, as well as library loading.
6334 This means that the existing catch command has changed; its first
6335 argument now specifies the type of catch to be set up. See the
6336 output of "help catch" for a list of catchpoint types.
6338 * Debugging across forks
6340 On HP-UX, you can choose which process to debug when a fork() happens
6345 HP has donated a curses-based terminal user interface (TUI). To get
6346 it, build with --enable-tui. Although this can be enabled for any
6347 configuration, at present it only works for native HP debugging.
6349 * GDB remote protocol additions
6351 A new protocol packet 'X' that writes binary data is now available.
6352 Default behavior is to try 'X', then drop back to 'M' if the stub
6353 fails to respond. The settable variable `remotebinarydownload'
6354 allows explicit control over the use of 'X'.
6356 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6357 full 64-bit address. The command
6359 set remoteaddresssize 32
6361 can be used to revert to the old behaviour. For existing remote stubs
6362 the change should not be noticed, as the additional address information
6365 In order to assist in debugging stubs, you may use the maintenance
6366 command `packet' to send any text string to the stub. For instance,
6368 maint packet heythere
6370 sends the packet "$heythere#<checksum>". Note that it is very easy to
6371 disrupt a debugging session by sending the wrong packet at the wrong
6374 The compare-sections command allows you to compare section data on the
6375 target to what is in the executable file without uploading or
6376 downloading, by comparing CRC checksums.
6378 * Tracing can collect general expressions
6380 You may now collect general expressions at tracepoints. This requires
6381 further additions to the target-side stub; see tracepoint.c and
6382 doc/agentexpr.texi for further details.
6384 * mask-address variable for Mips
6386 For Mips targets, you may control the zeroing of the upper 32 bits of
6387 a 64-bit address by entering `set mask-address on'. This is mainly
6388 of interest to users of embedded R4xxx and R5xxx processors.
6390 * Higher serial baud rates
6392 GDB's serial code now allows you to specify baud rates 57600, 115200,
6393 230400, and 460800 baud. (Note that your host system may not be able
6394 to achieve all of these rates.)
6398 The i960 configuration now includes an initial implementation of a
6399 builtin simulator, contributed by Jim Wilson.
6402 *** Changes in GDB-4.17:
6404 * New native configurations
6406 Alpha GNU/Linux alpha*-*-linux*
6407 Unixware 2.x i[3456]86-unixware2*
6408 Irix 6.x mips*-sgi-irix6*
6409 PowerPC GNU/Linux powerpc-*-linux*
6410 PowerPC Solaris powerpcle-*-solaris*
6411 Sparc GNU/Linux sparc-*-linux*
6412 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6416 Argonaut Risc Chip (ARC) arc-*-*
6417 Hitachi H8/300S h8300*-*-*
6418 Matsushita MN10200 w/simulator mn10200-*-*
6419 Matsushita MN10300 w/simulator mn10300-*-*
6420 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6421 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6422 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6423 Mitsubishi D10V w/simulator d10v-*-*
6424 Mitsubishi M32R/D w/simulator m32r-*-elf*
6425 Tsqware Sparclet sparclet-*-*
6426 NEC V850 w/simulator v850-*-*
6428 * New debugging protocols
6430 ARM with RDI protocol arm*-*-*
6431 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6432 DDB and LSI variants of PMON protocol mips*-*-*
6433 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6434 PowerPC with SDS protocol powerpc{,le}-*-eabi
6435 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6439 All configurations can now understand and use the DWARF 2 debugging
6440 format. The choice is automatic, if the symbol file contains DWARF 2
6445 GDB now includes basic Java language support. This support is
6446 only useful with Java compilers that produce native machine code.
6448 * solib-absolute-prefix and solib-search-path
6450 For SunOS and SVR4 shared libraries, you may now set the prefix for
6451 loading absolute shared library symbol files, and the search path for
6452 locating non-absolute shared library symbol files.
6454 * Live range splitting
6456 GDB can now effectively debug code for which GCC has performed live
6457 range splitting as part of its optimization. See gdb/doc/LRS for
6458 more details on the expected format of the stabs information.
6462 GDB's support for the GNU Hurd, including thread debugging, has been
6463 updated to work with current versions of the Hurd.
6467 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6468 instruction set. ARM GDB automatically detects when Thumb
6469 instructions are in use, and adjusts disassembly and backtracing
6474 GDB's MIPS target configurations now handle the MIP16 16-bit
6479 GDB now includes support for overlays; if an executable has been
6480 linked such that multiple sections are based at the same address, GDB
6481 will decide which section to use for symbolic info. You can choose to
6482 control the decision manually, using overlay commands, or implement
6483 additional target-side support and use "overlay load-target" to bring
6484 in the overlay mapping. Do "help overlay" for more detail.
6488 The command "info symbol <address>" displays information about
6489 the symbol at the specified address.
6493 The standard remote protocol now includes an extension that allows
6494 asynchronous collection and display of trace data. This requires
6495 extensive support in the target-side debugging stub. Tracing mode
6496 includes a new interaction mode in GDB and new commands: see the
6497 file tracepoint.c for more details.
6501 Configurations for embedded MIPS now include a simulator contributed
6502 by Cygnus Solutions. The simulator supports the instruction sets
6503 of most MIPS variants.
6507 Sparc configurations may now include the ERC32 simulator contributed
6508 by the European Space Agency. The simulator is not built into
6509 Sparc targets by default; configure with --enable-sim to include it.
6513 For target configurations that may include multiple variants of a
6514 basic architecture (such as MIPS and SH), you may now set the
6515 architecture explicitly. "set arch" sets, "info arch" lists
6516 the possible architectures.
6518 *** Changes in GDB-4.16:
6520 * New native configurations
6522 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6523 M68K NetBSD m68k-*-netbsd*
6524 PowerPC AIX 4.x powerpc-*-aix*
6525 PowerPC MacOS powerpc-*-macos*
6526 PowerPC Windows NT powerpcle-*-cygwin32
6527 RS/6000 AIX 4.x rs6000-*-aix4*
6531 ARM with RDP protocol arm-*-*
6532 I960 with MON960 i960-*-coff
6533 MIPS VxWorks mips*-*-vxworks*
6534 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6535 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6537 Matra Sparclet sparclet-*-*
6541 The powerpc-eabi configuration now includes the PSIM simulator,
6542 contributed by Andrew Cagney, with assistance from Mike Meissner.
6543 PSIM is a very elaborate model of the PowerPC, including not only
6544 basic instruction set execution, but also details of execution unit
6545 performance and I/O hardware. See sim/ppc/README for more details.
6549 GDB now works with Solaris 2.5.
6551 * Windows 95/NT native
6553 GDB will now work as a native debugger on Windows 95 and Windows NT.
6554 To build it from source, you must use the "gnu-win32" environment,
6555 which uses a DLL to emulate enough of Unix to run the GNU tools.
6556 Further information, binaries, and sources are available at
6557 ftp.cygnus.com, under pub/gnu-win32.
6559 * dont-repeat command
6561 If a user-defined command includes the command `dont-repeat', then the
6562 command will not be repeated if the user just types return. This is
6563 useful if the command is time-consuming to run, so that accidental
6564 extra keystrokes don't run the same command many times.
6566 * Send break instead of ^C
6568 The standard remote protocol now includes an option to send a break
6569 rather than a ^C to the target in order to interrupt it. By default,
6570 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6572 * Remote protocol timeout
6574 The standard remote protocol includes a new variable `remotetimeout'
6575 that allows you to set the number of seconds before GDB gives up trying
6576 to read from the target. The default value is 2.
6578 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6580 By default GDB will automatically keep track of objects as they are
6581 loaded and unloaded by the dynamic linker. By using the command `set
6582 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6583 when shared library events occur, thus allowing you to set breakpoints
6584 in shared libraries which are explicitly loaded by the inferior.
6586 Note this feature does not work on hpux8. On hpux9 you must link
6587 /usr/lib/end.o into your program. This feature should work
6588 automatically on hpux10.
6590 * Irix 5.x hardware watchpoint support
6592 Irix 5 configurations now support the use of hardware watchpoints.
6594 * Mips protocol "SYN garbage limit"
6596 When debugging a Mips target using the `target mips' protocol, you
6597 may set the number of characters that GDB will ignore by setting
6598 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6599 every character. The default value is 1050.
6601 * Recording and replaying remote debug sessions
6603 If you set `remotelogfile' to the name of a file, gdb will write to it
6604 a recording of a remote debug session. This recording may then be
6605 replayed back to gdb using "gdbreplay". See gdbserver/README for
6606 details. This is useful when you have a problem with GDB while doing
6607 remote debugging; you can make a recording of the session and send it
6608 to someone else, who can then recreate the problem.
6610 * Speedups for remote debugging
6612 GDB includes speedups for downloading and stepping MIPS systems using
6613 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6614 and more efficient S-record downloading.
6616 * Memory use reductions and statistics collection
6618 GDB now uses less memory and reports statistics about memory usage.
6619 Try the `maint print statistics' command, for example.
6621 *** Changes in GDB-4.15:
6623 * Psymtabs for XCOFF
6625 The symbol reader for AIX GDB now uses partial symbol tables. This
6626 can greatly improve startup time, especially for large executables.
6628 * Remote targets use caching
6630 Remote targets now use a data cache to speed up communication with the
6631 remote side. The data cache could lead to incorrect results because
6632 it doesn't know about volatile variables, thus making it impossible to
6633 debug targets which use memory mapped I/O devices. `set remotecache
6634 off' turns the the data cache off.
6636 * Remote targets may have threads
6638 The standard remote protocol now includes support for multiple threads
6639 in the target system, using new protocol commands 'H' and 'T'. See
6640 gdb/remote.c for details.
6644 If GDB is configured with `--enable-netrom', then it will include
6645 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6646 acts as though it is a bank of ROM on the target board, but you can
6647 write into it over the network. GDB's support consists only of
6648 support for fast loading into the emulated ROM; to debug, you must use
6649 another protocol, such as standard remote protocol. The usual
6650 sequence is something like
6652 target nrom <netrom-hostname>
6654 target remote <netrom-hostname>:1235
6658 GDB now includes support for the Apple Macintosh, as a host only. It
6659 may be run as either an MPW tool or as a standalone application, and
6660 it can debug through the serial port. All the usual GDB commands are
6661 available, but to the target command, you must supply "serial" as the
6662 device type instead of "/dev/ttyXX". See mpw-README in the main
6663 directory for more information on how to build. The MPW configuration
6664 scripts */mpw-config.in support only a few targets, and only the
6665 mips-idt-ecoff target has been tested.
6669 GDB configuration now uses autoconf. This is not user-visible,
6670 but does simplify configuration and building.
6674 GDB now supports hpux10.
6676 *** Changes in GDB-4.14:
6678 * New native configurations
6680 x86 FreeBSD i[345]86-*-freebsd
6681 x86 NetBSD i[345]86-*-netbsd
6682 NS32k NetBSD ns32k-*-netbsd
6683 Sparc NetBSD sparc-*-netbsd
6687 A29K VxWorks a29k-*-vxworks
6688 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6689 CPU32 EST-300 emulator m68*-*-est*
6690 PowerPC ELF powerpc-*-elf
6693 * Alpha OSF/1 support for procfs
6695 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6696 possible to attach to running processes. As the mounting of the /proc
6697 filesystem is optional on the Alpha, GDB automatically determines
6698 the availability of /proc during startup. This can lead to problems
6699 if /proc is unmounted after GDB has been started.
6701 * Arguments to user-defined commands
6703 User commands may accept up to 10 arguments separated by whitespace.
6704 Arguments are accessed within the user command via $arg0..$arg9. A
6707 print $arg0 + $arg1 + $arg2
6709 To execute the command use:
6712 Defines the command "adder" which prints the sum of its three arguments.
6713 Note the arguments are text substitutions, so they may reference variables,
6714 use complex expressions, or even perform inferior function calls.
6716 * New `if' and `while' commands
6718 This makes it possible to write more sophisticated user-defined
6719 commands. Both commands take a single argument, which is the
6720 expression to evaluate, and must be followed by the commands to
6721 execute, one per line, if the expression is nonzero, the list being
6722 terminated by the word `end'. The `if' command list may include an
6723 `else' word, which causes the following commands to be executed only
6724 if the expression is zero.
6726 * Fortran source language mode
6728 GDB now includes partial support for Fortran 77. It will recognize
6729 Fortran programs and can evaluate a subset of Fortran expressions, but
6730 variables and functions may not be handled correctly. GDB will work
6731 with G77, but does not yet know much about symbols emitted by other
6734 * Better HPUX support
6736 Most debugging facilities now work on dynamic executables for HPPAs
6737 running hpux9 or later. You can attach to running dynamically linked
6738 processes, but by default the dynamic libraries will be read-only, so
6739 for instance you won't be able to put breakpoints in them. To change
6740 that behavior do the following before running the program:
6746 This will cause the libraries to be mapped private and read-write.
6747 To revert to the normal behavior, do this:
6753 You cannot set breakpoints or examine data in the library until after
6754 the library is loaded if the function/data symbols do not have
6757 GDB can now also read debug symbols produced by the HP C compiler on
6758 HPPAs (sorry, no C++, Fortran or 68k support).
6760 * Target byte order now dynamically selectable
6762 You can choose which byte order to use with a target system, via the
6763 commands "set endian big" and "set endian little", and you can see the
6764 current setting by using "show endian". You can also give the command
6765 "set endian auto", in which case GDB will use the byte order
6766 associated with the executable. Currently, only embedded MIPS
6767 configurations support dynamic selection of target byte order.
6769 * New DOS host serial code
6771 This version uses DPMI interrupts to handle buffered I/O, so you
6772 no longer need to run asynctsr when debugging boards connected to
6775 *** Changes in GDB-4.13:
6777 * New "complete" command
6779 This lists all the possible completions for the rest of the line, if it
6780 were to be given as a command itself. This is intended for use by emacs.
6782 * Trailing space optional in prompt
6784 "set prompt" no longer adds a space for you after the prompt you set. This
6785 allows you to set a prompt which ends in a space or one that does not.
6787 * Breakpoint hit counts
6789 "info break" now displays a count of the number of times the breakpoint
6790 has been hit. This is especially useful in conjunction with "ignore"; you
6791 can ignore a large number of breakpoint hits, look at the breakpoint info
6792 to see how many times the breakpoint was hit, then run again, ignoring one
6793 less than that number, and this will get you quickly to the last hit of
6796 * Ability to stop printing at NULL character
6798 "set print null-stop" will cause GDB to stop printing the characters of
6799 an array when the first NULL is encountered. This is useful when large
6800 arrays actually contain only short strings.
6802 * Shared library breakpoints
6804 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6805 breakpoints in shared libraries before the executable is run.
6807 * Hardware watchpoints
6809 There is a new hardware breakpoint for the watch command for sparclite
6810 targets. See gdb/sparclite/hw_breakpoint.note.
6812 Hardware watchpoints are also now supported under GNU/Linux.
6816 Annotations have been added. These are for use with graphical interfaces,
6817 and are still experimental. Currently only gdba.el uses these.
6819 * Improved Irix 5 support
6821 GDB now works properly with Irix 5.2.
6823 * Improved HPPA support
6825 GDB now works properly with the latest GCC and GAS.
6827 * New native configurations
6829 Sequent PTX4 i[34]86-sequent-ptx4
6830 HPPA running OSF/1 hppa*-*-osf*
6831 Atari TT running SVR4 m68*-*-sysv4*
6832 RS/6000 LynxOS rs6000-*-lynxos*
6836 OS/9000 i[34]86-*-os9k
6837 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6840 * Hitachi SH7000 and E7000-PC ICE support
6842 There is now support for communicating with the Hitachi E7000-PC ICE.
6843 This is available automatically when GDB is configured for the SH.
6847 As usual, a variety of small fixes and improvements, both generic
6848 and configuration-specific. See the ChangeLog for more detail.
6850 *** Changes in GDB-4.12:
6852 * Irix 5 is now supported
6856 GDB-4.12 on the HPPA has a number of changes which make it unable
6857 to debug the output from the currently released versions of GCC and
6858 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6859 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6860 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6863 *** Changes in GDB-4.11:
6865 * User visible changes:
6869 The "set remotedebug" option is now consistent between the mips remote
6870 target, remote targets using the gdb-specific protocol, UDI (AMD's
6871 debug protocol for the 29k) and the 88k bug monitor. It is now an
6872 integer specifying a debug level (normally 0 or 1, but 2 means more
6873 debugging info for the mips target).
6875 * DEC Alpha native support
6877 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6878 debug info, but GDB works fairly well with the DEC compiler and should
6879 work with a future GCC release. See the README file for a few
6880 Alpha-specific notes.
6882 * Preliminary thread implementation
6884 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6886 * LynxOS native and target support for 386
6888 This release has been hosted on LynxOS 2.2, and also can be configured
6889 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6892 * Improvements in C++ mangling/demangling.
6894 This release has much better g++ debugging, specifically in name
6895 mangling/demangling, virtual function calls, print virtual table,
6896 call methods, ...etc.
6898 *** Changes in GDB-4.10:
6900 * User visible changes:
6902 Remote debugging using the GDB-specific (`target remote') protocol now
6903 supports the `load' command. This is only useful if you have some
6904 other way of getting the stub to the target system, and you can put it
6905 somewhere in memory where it won't get clobbered by the download.
6907 Filename completion now works.
6909 When run under emacs mode, the "info line" command now causes the
6910 arrow to point to the line specified. Also, "info line" prints
6911 addresses in symbolic form (as well as hex).
6913 All vxworks based targets now support a user settable option, called
6914 vxworks-timeout. This option represents the number of seconds gdb
6915 should wait for responses to rpc's. You might want to use this if
6916 your vxworks target is, perhaps, a slow software simulator or happens
6917 to be on the far side of a thin network line.
6921 This release contains support for using a DEC alpha as a GDB host for
6922 cross debugging. Native alpha debugging is not supported yet.
6925 *** Changes in GDB-4.9:
6929 This is the first GDB release which is accompanied by a matching testsuite.
6930 The testsuite requires installation of dejagnu, which should be available
6931 via ftp from most sites that carry GNU software.
6935 'Cfront' style demangling has had its name changed to 'ARM' style, to
6936 emphasize that it was written from the specifications in the C++ Annotated
6937 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6938 disclaimers, it still generated too much confusion with users attempting to
6939 use gdb with AT&T cfront.
6943 GDB now uses a standard remote interface to a simulator library.
6944 So far, the library contains simulators for the Zilog Z8001/2, the
6945 Hitachi H8/300, H8/500 and Super-H.
6947 * New targets supported
6949 H8/300 simulator h8300-hitachi-hms or h8300hms
6950 H8/500 simulator h8500-hitachi-hms or h8500hms
6951 SH simulator sh-hitachi-hms or sh
6952 Z8000 simulator z8k-zilog-none or z8ksim
6953 IDT MIPS board over serial line mips-idt-ecoff
6955 Cross-debugging to GO32 targets is supported. It requires a custom
6956 version of the i386-stub.c module which is integrated with the
6957 GO32 memory extender.
6959 * New remote protocols
6961 MIPS remote debugging protocol.
6963 * New source languages supported
6965 This version includes preliminary support for Chill, a Pascal like language
6966 used by telecommunications companies. Chill support is also being integrated
6967 into the GNU compiler, but we don't know when it will be publically available.
6970 *** Changes in GDB-4.8:
6972 * HP Precision Architecture supported
6974 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6975 version of this support was available as a set of patches from the
6976 University of Utah. GDB does not support debugging of programs
6977 compiled with the HP compiler, because HP will not document their file
6978 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6979 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6981 Many problems in the preliminary version have been fixed.
6983 * Faster and better demangling
6985 We have improved template demangling and fixed numerous bugs in the GNU style
6986 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6987 character types (wchar_t) are now supported. Demangling of each symbol is now
6988 only done once, and is cached when the symbol table for a file is read in.
6989 This results in a small increase in memory usage for C programs, a moderate
6990 increase in memory usage for C++ programs, and a fantastic speedup in
6993 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6994 from the specifications in the Annotated Reference Manual, which AT&T's
6995 compiler does not actually implement.
6997 * G++ multiple inheritance compiler problem
6999 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7000 inheritance lattices was reworked to properly discover ambiguities. We
7001 recently found an example which causes this new algorithm to fail in a
7002 very subtle way, producing bad debug information for those classes.
7003 The file 'gcc.patch' (in this directory) can be applied to gcc to
7004 circumvent the problem. A future GCC release will contain a complete
7007 The previous G++ debug info problem (mentioned below for the gdb-4.7
7008 release) is fixed in gcc version 2.3.2.
7010 * Improved configure script
7012 The `configure' script will now attempt to guess your system type if
7013 you don't supply a host system type. The old scheme of supplying a
7014 host system triplet is preferable over using this. All the magic is
7015 done in the new `config.guess' script. Examine it for details.
7017 We have also brought our configure script much more in line with the FSF's
7018 version. It now supports the --with-xxx options. In particular,
7019 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7020 The resulting GDB will not be able to read arbitrary object file formats --
7021 only the format ``expected'' to be used on the configured target system.
7022 We hope to make this the default in a future release.
7024 * Documentation improvements
7026 There's new internal documentation on how to modify GDB, and how to
7027 produce clean changes to the code. We implore people to read it
7028 before submitting changes.
7030 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7031 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7032 `info' files are also provided. To build `info' files from scratch,
7033 you will need the latest `makeinfo' release, which will be available in
7034 a future texinfo-X.Y release.
7036 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7037 We're not sure exactly which versions have this problem, but it has
7038 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7039 or better. If that isn't possible, there is a patch in
7040 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7041 around this problem.
7045 GDB now supports array constants that can be used in expressions typed in by
7046 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7047 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7050 The new directory `gdb/sparclite' contains a program that demonstrates
7051 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7053 * New native hosts supported
7055 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7056 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7058 * New targets supported
7060 AMD 29k family via UDI a29k-amd-udi or udi29k
7062 * New file formats supported
7064 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7065 HPUX core files, and SCO 3.2v2 core files.
7069 Attaching to processes now works again; thanks for the many bug reports.
7071 We have also stomped on a bunch of core dumps caused by
7072 printf_filtered("%s") problems.
7074 We eliminated a copyright problem on the rpc and ptrace header files
7075 for VxWorks, which was discovered at the last minute during the 4.7
7076 release. You should now be able to build a VxWorks GDB.
7078 You can now interrupt gdb while an attached process is running. This
7079 will cause the attached process to stop, and give control back to GDB.
7081 We fixed problems caused by using too many file descriptors
7082 for reading symbols from object files and libraries. This was
7083 especially a problem for programs that used many (~100) shared
7086 The `step' command now only enters a subroutine if there is line number
7087 information for the subroutine. Otherwise it acts like the `next'
7088 command. Previously, `step' would enter subroutines if there was
7089 any debugging information about the routine. This avoids problems
7090 when using `cc -g1' on MIPS machines.
7092 * Internal improvements
7094 GDB's internal interfaces have been improved to make it easier to support
7095 debugging of multiple languages in the future.
7097 GDB now uses a common structure for symbol information internally.
7098 Minimal symbols (derived from linkage symbols in object files), partial
7099 symbols (from a quick scan of debug information), and full symbols
7100 contain a common subset of information, making it easier to write
7101 shared code that handles any of them.
7103 * New command line options
7105 We now accept --silent as an alias for --quiet.
7109 The memory-mapped-malloc library is now licensed under the GNU Library
7110 General Public License.
7112 *** Changes in GDB-4.7:
7114 * Host/native/target split
7116 GDB has had some major internal surgery to untangle the support for
7117 hosts and remote targets. Now, when you configure GDB for a remote
7118 target, it will no longer load in all of the support for debugging
7119 local programs on the host. When fully completed and tested, this will
7120 ensure that arbitrary host/target combinations are possible.
7122 The primary conceptual shift is to separate the non-portable code in
7123 GDB into three categories. Host specific code is required any time GDB
7124 is compiled on that host, regardless of the target. Target specific
7125 code relates to the peculiarities of the target, but can be compiled on
7126 any host. Native specific code is everything else: it can only be
7127 built when the host and target are the same system. Child process
7128 handling and core file support are two common `native' examples.
7130 GDB's use of /proc for controlling Unix child processes is now cleaner.
7131 It has been split out into a single module under the `target_ops' vector,
7132 plus two native-dependent functions for each system that uses /proc.
7134 * New hosts supported
7136 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7137 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7138 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7140 * New targets supported
7142 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7143 68030 and CPU32 m68030-*-*, m68332-*-*
7145 * New native hosts supported
7147 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7148 (386bsd is not well tested yet)
7149 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7151 * New file formats supported
7153 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7154 supports reading of `a.out.adobe' object files, which are an a.out
7155 format extended with minimal information about multiple sections.
7159 `show copying' is the same as the old `info copying'.
7160 `show warranty' is the same as `info warrantee'.
7161 These were renamed for consistency. The old commands continue to work.
7163 `info handle' is a new alias for `info signals'.
7165 You can now define pre-command hooks, which attach arbitrary command
7166 scripts to any command. The commands in the hook will be executed
7167 prior to the user's command. You can also create a hook which will be
7168 executed whenever the program stops. See gdb.texinfo.
7172 We now deal with Cfront style name mangling, and can even extract type
7173 info from mangled symbols. GDB can automatically figure out which
7174 symbol mangling style your C++ compiler uses.
7176 Calling of methods and virtual functions has been improved as well.
7180 The crash that occured when debugging Sun Ansi-C compiled binaries is
7181 fixed. This was due to mishandling of the extra N_SO stabs output
7184 We also finally got Ultrix 4.2 running in house, and fixed core file
7185 support, with help from a dozen people on the net.
7187 John M. Farrell discovered that the reason that single-stepping was so
7188 slow on all of the Mips based platforms (primarily SGI and DEC) was
7189 that we were trying to demangle and lookup a symbol used for internal
7190 purposes on every instruction that was being stepped through. Changing
7191 the name of that symbol so that it couldn't be mistaken for a C++
7192 mangled symbol sped things up a great deal.
7194 Rich Pixley sped up symbol lookups in general by getting much smarter
7195 about when C++ symbol mangling is necessary. This should make symbol
7196 completion (TAB on the command line) much faster. It's not as fast as
7197 we'd like, but it's significantly faster than gdb-4.6.
7201 A new user controllable variable 'call_scratch_address' can
7202 specify the location of a scratch area to be used when GDB
7203 calls a function in the target. This is necessary because the
7204 usual method of putting the scratch area on the stack does not work
7205 in systems that have separate instruction and data spaces.
7207 We integrated changes to support the 29k UDI (Universal Debugger
7208 Interface), but discovered at the last minute that we didn't have all
7209 of the appropriate copyright paperwork. We are working with AMD to
7210 resolve this, and hope to have it available soon.
7214 We have sped up the remote serial line protocol, especially for targets
7215 with lots of registers. It now supports a new `expedited status' ('T')
7216 message which can be used in place of the existing 'S' status message.
7217 This allows the remote stub to send only the registers that GDB
7218 needs to make a quick decision about single-stepping or conditional
7219 breakpoints, eliminating the need to fetch the entire register set for
7220 each instruction being stepped through.
7222 The GDB remote serial protocol now implements a write-through cache for
7223 registers, only re-reading the registers if the target has run.
7225 There is also a new remote serial stub for SPARC processors. You can
7226 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7227 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7228 processor with a serial port.
7232 Configure.in files have become much easier to read and modify. A new
7233 `table driven' format makes it more obvious what configurations are
7234 supported, and what files each one uses.
7238 There is a new opcodes library which will eventually contain all of the
7239 disassembly routines and opcode tables. At present, it only contains
7240 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7241 disassembler (binutils/objdump) to share these routines.
7243 The libiberty library is now copylefted under the GNU Library General
7244 Public License. This allows more liberal use, and was done so libg++
7245 can use it. This makes no difference to GDB, since the Library License
7246 grants all the rights from the General Public License.
7250 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7251 reference to the stabs symbol info used by the debugger. It is (as far
7252 as we know) the only published document on this fascinating topic. We
7253 encourage you to read it, compare it to the stabs information on your
7254 system, and send improvements on the document in general (to
7255 bug-gdb@prep.ai.mit.edu).
7257 And, of course, many bugs have been fixed.
7260 *** Changes in GDB-4.6:
7262 * Better support for C++ function names
7264 GDB now accepts as input the "demangled form" of C++ overloaded function
7265 names and member function names, and can do command completion on such names
7266 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7267 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7268 Make use of command completion, it is your friend.
7270 GDB also now accepts a variety of C++ mangled symbol formats. They are
7271 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7272 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7273 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7274 for the list of formats.
7276 * G++ symbol mangling problem
7278 Recent versions of gcc have a bug in how they emit debugging information for
7279 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7280 directory) can be applied to gcc to fix the problem. Alternatively, if you
7281 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7282 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7283 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7286 * New 'maintenance' command
7288 All of the commands related to hacking GDB internals have been moved out of
7289 the main command set, and now live behind the 'maintenance' command. This
7290 can also be abbreviated as 'mt'. The following changes were made:
7292 dump-me -> maintenance dump-me
7293 info all-breakpoints -> maintenance info breakpoints
7294 printmsyms -> maintenance print msyms
7295 printobjfiles -> maintenance print objfiles
7296 printpsyms -> maintenance print psymbols
7297 printsyms -> maintenance print symbols
7299 The following commands are new:
7301 maintenance demangle Call internal GDB demangler routine to
7302 demangle a C++ link name and prints the result.
7303 maintenance print type Print a type chain for a given symbol
7305 * Change to .gdbinit file processing
7307 We now read the $HOME/.gdbinit file before processing the argv arguments
7308 (e.g. reading symbol files or core files). This allows global parameters to
7309 be set, which will apply during the symbol reading. The ./.gdbinit is still
7310 read after argv processing.
7312 * New hosts supported
7314 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7316 GNU/Linux support i386-unknown-linux or linux
7318 We are also including code to support the HP/PA running BSD and HPUX. This
7319 is almost guaranteed not to work, as we didn't have time to test or build it
7320 for this release. We are including it so that the more adventurous (or
7321 masochistic) of you can play with it. We also had major problems with the
7322 fact that the compiler that we got from HP doesn't support the -g option.
7325 * New targets supported
7327 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7329 * More smarts about finding #include files
7331 GDB now remembers the compilation directory for all include files, and for
7332 all files from which C is generated (like yacc and lex sources). This
7333 greatly improves GDB's ability to find yacc/lex sources, and include files,
7334 especially if you are debugging your program from a directory different from
7335 the one that contains your sources.
7337 We also fixed a bug which caused difficulty with listing and setting
7338 breakpoints in include files which contain C code. (In the past, you had to
7339 try twice in order to list an include file that you hadn't looked at before.)
7341 * Interesting infernals change
7343 GDB now deals with arbitrary numbers of sections, where the symbols for each
7344 section must be relocated relative to that section's landing place in the
7345 target's address space. This work was needed to support ELF with embedded
7346 stabs used by Solaris-2.0.
7348 * Bug fixes (of course!)
7350 There have been loads of fixes for the following things:
7351 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7352 i960, stabs, DOS(GO32), procfs, etc...
7354 See the ChangeLog for details.
7356 *** Changes in GDB-4.5:
7358 * New machines supported (host and target)
7360 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7362 SGI Irix-4.x mips-sgi-irix4 or iris4
7364 * New malloc package
7366 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7367 Mmalloc is capable of handling mutiple heaps of memory. It is also
7368 capable of saving a heap to a file, and then mapping it back in later.
7369 This can be used to greatly speedup the startup of GDB by using a
7370 pre-parsed symbol table which lives in a mmalloc managed heap. For
7371 more details, please read mmalloc/mmalloc.texi.
7375 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7376 'help info proc' for details.
7378 * MIPS ecoff symbol table format
7380 The code that reads MIPS symbol table format is now supported on all hosts.
7381 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7384 * File name changes for MS-DOS
7386 Many files in the config directories have been renamed to make it easier to
7387 support GDB on MS-DOSe systems (which have very restrictive file name
7388 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7389 environment) is close to working but has some remaining problems. Note
7390 that debugging of DOS programs is not supported, due to limitations
7391 in the ``operating system'', but it can be used to host cross-debugging.
7393 * Cross byte order fixes
7395 Many fixes have been made to support cross debugging of Sparc and MIPS
7396 targets from hosts whose byte order differs.
7398 * New -mapped and -readnow options
7400 If memory-mapped files are available on your system through the 'mmap'
7401 system call, you can use the -mapped option on the `file' or
7402 `symbol-file' commands to cause GDB to write the symbols from your
7403 program into a reusable file. If the program you are debugging is
7404 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7405 Future GDB debugging sessions will notice the presence of this file,
7406 and will quickly map in symbol information from it, rather than reading
7407 the symbol table from the executable program. Using the '-mapped'
7408 option in a GDB `file' or `symbol-file' command has the same effect as
7409 starting GDB with the '-mapped' command-line option.
7411 You can cause GDB to read the entire symbol table immediately by using
7412 the '-readnow' option with any of the commands that load symbol table
7413 information (or on the GDB command line). This makes the command
7414 slower, but makes future operations faster.
7416 The -mapped and -readnow options are typically combined in order to
7417 build a `fred.syms' file that contains complete symbol information.
7418 A simple GDB invocation to do nothing but build a `.syms' file for future
7421 gdb -batch -nx -mapped -readnow programname
7423 The `.syms' file is specific to the host machine on which GDB is run.
7424 It holds an exact image of GDB's internal symbol table. It cannot be
7425 shared across multiple host platforms.
7427 * longjmp() handling
7429 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7430 siglongjmp() without losing control. This feature has not yet been ported to
7431 all systems. It currently works on many 386 platforms, all MIPS-based
7432 platforms (SGI, DECstation, etc), and Sun3/4.
7436 Preliminary work has been put in to support the new Solaris OS from Sun. At
7437 this time, it can control and debug processes, but it is not capable of
7442 As always, many many bug fixes. The major areas were with g++, and mipsread.
7443 People using the MIPS-based platforms should experience fewer mysterious
7444 crashes and trashed symbol tables.
7446 *** Changes in GDB-4.4:
7448 * New machines supported (host and target)
7450 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7452 BSD Reno on Vax vax-dec-bsd
7453 Ultrix on Vax vax-dec-ultrix
7455 * New machines supported (target)
7457 AMD 29000 embedded, using EBMON a29k-none-none
7461 GDB continues to improve its handling of C++. `References' work better.
7462 The demangler has also been improved, and now deals with symbols mangled as
7463 per the Annotated C++ Reference Guide.
7465 GDB also now handles `stabs' symbol information embedded in MIPS
7466 `ecoff' symbol tables. Since the ecoff format was not easily
7467 extensible to handle new languages such as C++, this appeared to be a
7468 good way to put C++ debugging info into MIPS binaries. This option
7469 will be supported in the GNU C compiler, version 2, when it is
7472 * New features for SVR4
7474 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7475 shared libraries. Debugging dynamically linked programs should present
7476 only minor differences from debugging statically linked programs.
7478 The `info proc' command will print out information about any process
7479 on an SVR4 system (including the one you are debugging). At the moment,
7480 it prints the address mappings of the process.
7482 If you bring up GDB on another SVR4 system, please send mail to
7483 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7485 * Better dynamic linking support in SunOS
7487 Reading symbols from shared libraries which contain debugging symbols
7488 now works properly. However, there remain issues such as automatic
7489 skipping of `transfer vector' code during function calls, which
7490 make it harder to debug code in a shared library, than to debug the
7491 same code linked statically.
7495 GDB is now using the latest `getopt' routines from the FSF. This
7496 version accepts the -- prefix for options with long names. GDB will
7497 continue to accept the old forms (-option and +option) as well.
7498 Various single letter abbreviations for options have been explicity
7499 added to the option table so that they won't get overshadowed in the
7500 future by other options that begin with the same letter.
7504 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7505 Many assorted bugs have been handled. Many more remain to be handled.
7506 See the various ChangeLog files (primarily in gdb and bfd) for details.
7509 *** Changes in GDB-4.3:
7511 * New machines supported (host and target)
7513 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7514 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7515 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7517 * Almost SCO Unix support
7519 We had hoped to support:
7520 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7521 (except for core file support), but we discovered very late in the release
7522 that it has problems with process groups that render gdb unusable. Sorry
7523 about that. I encourage people to fix it and post the fixes.
7525 * Preliminary ELF and DWARF support
7527 GDB can read ELF object files on System V Release 4, and can handle
7528 debugging records for C, in DWARF format, in ELF files. This support
7529 is preliminary. If you bring up GDB on another SVR4 system, please
7530 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7535 GDB now uses the latest `readline' library. One user-visible change
7536 is that two tabs will list possible command completions, which previously
7537 required typing M-? (meta-question mark, or ESC ?).
7541 The `stepi' bug that many of you noticed has been squashed.
7542 Many bugs in C++ have been handled. Many more remain to be handled.
7543 See the various ChangeLog files (primarily in gdb and bfd) for details.
7545 * State of the MIPS world (in case you wondered):
7547 GDB can understand the symbol tables emitted by the compilers
7548 supplied by most vendors of MIPS-based machines, including DEC. These
7549 symbol tables are in a format that essentially nobody else uses.
7551 Some versions of gcc come with an assembler post-processor called
7552 mips-tfile. This program is required if you want to do source-level
7553 debugging of gcc-compiled programs. I believe FSF does not ship
7554 mips-tfile with gcc version 1, but it will eventually come with gcc
7557 Debugging of g++ output remains a problem. g++ version 1.xx does not
7558 really support it at all. (If you're lucky, you should be able to get
7559 line numbers and stack traces to work, but no parameters or local
7560 variables.) With some work it should be possible to improve the
7563 When gcc version 2 is released, you will have somewhat better luck.
7564 However, even then you will get confusing results for inheritance and
7567 We will eventually provide full debugging of g++ output on
7568 DECstations. This will probably involve some kind of stabs-in-ecoff
7569 encapulation, but the details have not been worked out yet.
7572 *** Changes in GDB-4.2:
7574 * Improved configuration
7576 Only one copy of `configure' exists now, and it is not self-modifying.
7577 Porting BFD is simpler.
7581 The `step' and `next' commands now only stop at the first instruction
7582 of a source line. This prevents the multiple stops that used to occur
7583 in switch statements, for-loops, etc. `Step' continues to stop if a
7584 function that has debugging information is called within the line.
7588 Lots of small bugs fixed. More remain.
7590 * New host supported (not target)
7592 Intel 386 PC clone running Mach i386-none-mach
7595 *** Changes in GDB-4.1:
7597 * Multiple source language support
7599 GDB now has internal scaffolding to handle several source languages.
7600 It determines the type of each source file from its filename extension,
7601 and will switch expression parsing and number formatting to match the
7602 language of the function in the currently selected stack frame.
7603 You can also specifically set the language to be used, with
7604 `set language c' or `set language modula-2'.
7608 GDB now has preliminary support for the GNU Modula-2 compiler,
7609 currently under development at the State University of New York at
7610 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7611 continue through the fall of 1991 and into 1992.
7613 Other Modula-2 compilers are currently not supported, and attempting to
7614 debug programs compiled with them will likely result in an error as the
7615 symbol table is read. Feel free to work on it, though!
7617 There are hooks in GDB for strict type checking and range checking,
7618 in the `Modula-2 philosophy', but they do not currently work.
7622 GDB can now write to executable and core files (e.g. patch
7623 a variable's value). You must turn this switch on, specify
7624 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7625 by assigning a new value to a variable. Modifications take
7628 * Automatic SunOS shared library reading
7630 When you run your program, GDB automatically determines where its
7631 shared libraries (if any) have been loaded, and reads their symbols.
7632 The `share' command is no longer needed. This also works when
7633 examining core files.
7637 You can specify the number of lines that the `list' command shows.
7640 * New machines supported (host and target)
7642 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7643 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7644 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7646 * New hosts supported (not targets)
7648 IBM RT/PC: romp-ibm-aix or rtpc
7650 * New targets supported (not hosts)
7652 AMD 29000 embedded with COFF a29k-none-coff
7653 AMD 29000 embedded with a.out a29k-none-aout
7654 Ultracomputer remote kernel debug a29k-nyu-kern
7656 * New remote interfaces
7662 *** Changes in GDB-4.0:
7666 Wide output is wrapped at good places to make the output more readable.
7668 Gdb now supports cross-debugging from a host machine of one type to a
7669 target machine of another type. Communication with the target system
7670 is over serial lines. The ``target'' command handles connecting to the
7671 remote system; the ``load'' command will download a program into the
7672 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7673 also supports debugging of realtime processes running under VxWorks,
7674 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7675 stub on the target system.
7677 New CPUs supported include the AMD 29000 and Intel 960.
7679 GDB now reads object files and symbol tables via a ``binary file''
7680 library, which allows a single copy of GDB to debug programs of multiple
7681 object file types such as a.out and coff.
7683 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7684 refcard.dvi and refcard.ps are available to format it).
7687 * Control-Variable user interface simplified
7689 All variables that control the operation of the debugger can be set
7690 by the ``set'' command, and displayed by the ``show'' command.
7692 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7693 ``Show prompt'' produces the response:
7694 Gdb's prompt is new-gdb=>.
7696 What follows are the NEW set commands. The command ``help set'' will
7697 print a complete list of old and new set commands. ``help set FOO''
7698 will give a longer description of the variable FOO. ``show'' will show
7699 all of the variable descriptions and their current settings.
7701 confirm on/off: Enables warning questions for operations that are
7702 hard to recover from, e.g. rerunning the program while
7703 it is already running. Default is ON.
7705 editing on/off: Enables EMACS style command line editing
7706 of input. Previous lines can be recalled with
7707 control-P, the current line can be edited with control-B,
7708 you can search for commands with control-R, etc.
7711 history filename NAME: NAME is where the gdb command history
7712 will be stored. The default is .gdb_history,
7713 or the value of the environment variable
7716 history size N: The size, in commands, of the command history. The
7717 default is 256, or the value of the environment variable
7720 history save on/off: If this value is set to ON, the history file will
7721 be saved after exiting gdb. If set to OFF, the
7722 file will not be saved. The default is OFF.
7724 history expansion on/off: If this value is set to ON, then csh-like
7725 history expansion will be performed on
7726 command line input. The default is OFF.
7728 radix N: Sets the default radix for input and output. It can be set
7729 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7730 in the current radix, so "set radix 10" is always a no-op.
7732 height N: This integer value is the number of lines on a page. Default
7733 is 24, the current `stty rows'' setting, or the ``li#''
7734 setting from the termcap entry matching the environment
7737 width N: This integer value is the number of characters on a line.
7738 Default is 80, the current `stty cols'' setting, or the ``co#''
7739 setting from the termcap entry matching the environment
7742 Note: ``set screensize'' is obsolete. Use ``set height'' and
7743 ``set width'' instead.
7745 print address on/off: Print memory addresses in various command displays,
7746 such as stack traces and structure values. Gdb looks
7747 more ``symbolic'' if you turn this off; it looks more
7748 ``machine level'' with it on. Default is ON.
7750 print array on/off: Prettyprint arrays. New convenient format! Default
7753 print demangle on/off: Print C++ symbols in "source" form if on,
7756 print asm-demangle on/off: Same, for assembler level printouts
7759 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7762 * Support for Epoch Environment.
7764 The epoch environment is a version of Emacs v18 with windowing. One
7765 new command, ``inspect'', is identical to ``print'', except that if you
7766 are running in the epoch environment, the value is printed in its own
7770 * Support for Shared Libraries
7772 GDB can now debug programs and core files that use SunOS shared libraries.
7773 Symbols from a shared library cannot be referenced
7774 before the shared library has been linked with the program (this
7775 happens after you type ``run'' and before the function main() is entered).
7776 At any time after this linking (including when examining core files
7777 from dynamically linked programs), gdb reads the symbols from each
7778 shared library when you type the ``sharedlibrary'' command.
7779 It can be abbreviated ``share''.
7781 sharedlibrary REGEXP: Load shared object library symbols for files
7782 matching a unix regular expression. No argument
7783 indicates to load symbols for all shared libraries.
7785 info sharedlibrary: Status of loaded shared libraries.
7790 A watchpoint stops execution of a program whenever the value of an
7791 expression changes. Checking for this slows down execution
7792 tremendously whenever you are in the scope of the expression, but is
7793 quite useful for catching tough ``bit-spreader'' or pointer misuse
7794 problems. Some machines such as the 386 have hardware for doing this
7795 more quickly, and future versions of gdb will use this hardware.
7797 watch EXP: Set a watchpoint (breakpoint) for an expression.
7799 info watchpoints: Information about your watchpoints.
7801 delete N: Deletes watchpoint number N (same as breakpoints).
7802 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7803 enable N: Re-enables watchpoint number N (same as breakpoints).
7806 * C++ multiple inheritance
7808 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7811 * C++ exception handling
7813 Gdb now supports limited C++ exception handling. Besides the existing
7814 ability to breakpoint on an exception handler, gdb can breakpoint on
7815 the raising of an exception (before the stack is peeled back to the
7818 catch FOO: If there is a FOO exception handler in the dynamic scope,
7819 set a breakpoint to catch exceptions which may be raised there.
7820 Multiple exceptions (``catch foo bar baz'') may be caught.
7822 info catch: Lists all exceptions which may be caught in the
7823 current stack frame.
7826 * Minor command changes
7828 The command ``call func (arg, arg, ...)'' now acts like the print
7829 command, except it does not print or save a value if the function's result
7830 is void. This is similar to dbx usage.
7832 The ``up'' and ``down'' commands now always print the frame they end up
7833 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7834 frames without printing.
7836 * New directory command
7838 'dir' now adds directories to the FRONT of the source search path.
7839 The path starts off empty. Source files that contain debug information
7840 about the directory in which they were compiled can be found even
7841 with an empty path; Sun CC and GCC include this information. If GDB can't
7842 find your source file in the current directory, type "dir .".
7844 * Configuring GDB for compilation
7846 For normal use, type ``./configure host''. See README or gdb.texinfo
7849 GDB now handles cross debugging. If you are remotely debugging between
7850 two different machines, type ``./configure host -target=targ''.
7851 Host is the machine where GDB will run; targ is the machine
7852 where the program that you are debugging will run.