1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * Help and apropos commands will now show the documentation of a
7 command only once, even if that command has one or more aliases.
8 These commands now show the command name, then all of its aliases,
9 and finally the description of the command.
11 * 'help aliases' now shows only the user defined aliases. GDB predefined
12 aliases are shown together with their aliased command.
14 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
15 debugging information as well as source code.
17 When built with debuginfod, GDB can automatically query debuginfod
18 servers for the separate debug files and source code of the executable
21 To build GDB with debuginfod, pass --with-debuginfod to configure (this
22 requires libdebuginfod, the debuginfod client library).
24 debuginfod is distributed with elfutils, starting with version 0.178.
26 You can get the latest version from https://sourceware.org/elfutils.
28 * New features in the GDB remote stub, GDBserver
30 ** GDBserver is now supported on RISC-V GNU/Linux.
32 ** GDBserver no longer supports these host triplets:
43 i[34567]86-*-mingw32ce*
45 * Debugging MS-Windows processes now sets $_exitsignal when the
46 inferior is terminated by a signal, instead of setting $_exitcode.
48 * Multithreaded symbol loading has now been enabled by default on systems
49 that support it (see entry for GDB 9, below), providing faster
50 performance for programs with many symbols.
52 * The $_siginfo convenience variable now also works on Windows targets,
53 and will display the EXCEPTION_RECORD of the last handled exception.
55 * TUI windows can now be arranged horizontally.
57 * The command history filename can now be set to the empty string
58 either using 'set history filename' or by setting 'GDBHISTFILE=' in
59 the environment. The effect of setting this filename to the empty
60 string is that GDB will not try to load any previous command
63 * On Windows targets, it is now possible to debug 32-bit programs with a
68 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
69 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
70 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
71 running process, this new option indicates whether to detect
72 a mismatch between the current executable file loaded by GDB and the
73 executable file used to start the process. If 'ask', the default,
74 display a warning and ask the user whether to load the process
75 executable file; if 'warn', just display a warning; if 'off', don't
76 attempt to detect a mismatch.
78 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
79 Define a new TUI layout, specifying its name and the windows that
82 maintenance print xml-tdesc [FILE]
83 Prints the current target description as an XML document. If the
84 optional FILE is provided (which is an XML target description) then
85 the target description is read from FILE into GDB, and then
88 maintenance print core-file-backed-mappings
89 Prints file-backed mappings loaded from a core file's note section.
90 Output is expected to be similar to that of "info proc mappings".
94 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
95 The alias command can now specify default args for an alias.
96 GDB automatically prepends the alias default args to the argument list
97 provided explicitly by the user.
98 For example, to have a backtrace with full details, you can define
100 'alias bt_ALL = backtrace -entry-values both -frame-arg all
101 -past-main -past-entry -full'.
102 Alias default arguments can also use a set of nested 'with' commands,
103 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
104 defines the alias pp10 that will pretty print a maximum of 10 elements
105 of the given expression (if the expression is an array).
109 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
113 ** gdb.register_window_type can be used to implement new TUI windows
116 ** Dynamic types can now be queried. gdb.Type has a new attribute,
117 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
118 field of a dynamic type may have None for its "bitpos" attribute
121 ** Commands written in Python can be in the "TUI" help class by
122 registering with the new constant gdb.COMMAND_TUI.
124 ** New method gdb.PendingFrame.architecture () to retrieve the
125 architecture of the pending frame.
127 ** New gdb.Architecture.registers method that returns a
128 gdb.RegisterDescriptorIterator object, an iterator that returns
129 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
130 way to query the registers available for an architecture.
132 ** New gdb.Architecture.register_groups method that returns a
133 gdb.RegisterGroupIterator object, an iterator that returns
134 gdb.RegisterGroup objects. The new RegisterGroup is a way to
135 discover the available register groups.
139 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
141 ** Procedures 'memory-port-read-buffer-size',
142 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
143 and 'set-memory-port-write-buffer-size!' are deprecated. When
144 using Guile 2.2 and later, users who need to control the size of
145 a memory port's internal buffer can use the 'setvbuf' procedure.
149 * 'thread-exited' event is now available in the annotations interface.
151 * New built-in convenience variables $_gdb_major and $_gdb_minor
152 provide the GDB version. They are handy for conditionally using
153 features available only in or since specific GDB versions, in
154 scripts that should work error-free with many different versions,
155 such as in system-wide init files.
157 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
158 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
159 of the GDB settings and the GDB maintenance settings. They are handy
160 for changing the logic of user defined commands depending on the
161 current GDB settings.
163 * GDB now supports Thread Local Storage (TLS) variables on several
164 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
165 architectures require kernel changes. TLS is not yet supported for
166 amd64 and i386 process core dumps.
168 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
169 addresses that required unmasking are shown in the backtrace with the
172 * Two new convenience functions $_cimag and $_creal that extract the
173 imaginary and real parts respectively from complex numbers.
175 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
176 provide the exitcode or exit status of the shell commands launched by
177 GDB commands such as "shell", "pipe" and "make".
179 * The command define-prefix can now define user defined prefix commands.
180 User defined commands can now be defined using these user defined prefix
183 * Command names can now use the . character.
185 * The RX port now supports XML target descriptions.
187 * GDB now shows the Ada task names at more places, e.g. in task switching
190 * GDB can now be compiled with Python 3 on Windows.
192 * New convenience variable $_ada_exception holds the address of the
193 Ada exception being thrown. This is set by Ada-related catchpoints.
195 * GDB can now place breakpoints on nested functions and subroutines in
196 Fortran code. The '::' operator can be used between parent and
197 child scopes when placing breakpoints, for example:
199 (gdb) break outer_function::inner_function
201 The 'outer_function::' prefix is only needed if 'inner_function' is
202 not visible in the current scope.
204 * In addition to the system-wide gdbinit file, if configured with
205 --with-system-gdbinit-dir, GDB will now also load files in that directory
206 as system gdbinit files, unless the -nx or -n flag is provided. Files
207 with extensions .gdb, .py and .scm are supported as long as GDB was
208 compiled with support for that language.
210 * GDB now supports multithreaded symbol loading for higher performance.
211 This feature is still in testing, so it is disabled by default. You
212 can turn it on using 'maint set worker-threads unlimited'.
214 * Multi-target debugging support
216 GDB now supports debugging multiple target connections
217 simultaneously. For example, you can now have each inferior
218 connected to different remote servers running in different machines,
219 or have one inferior debugging a local native process, an inferior
220 debugging a core dump, etc.
222 This support is experimental and comes with some limitations -- you
223 can only resume multiple targets simultaneously if all targets
224 support non-stop mode, and all remote stubs or servers must support
225 the same set of remote protocol features exactly. See also "info
226 connections" and "add-inferior -no-connection" below, and "maint set
227 target-non-stop" in the user manual.
231 ** The gdb.Value type has a new method 'format_string' which returns a
232 string representing the value. The formatting is controlled by the
233 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
234 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
235 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
237 ** gdb.Type has a new property 'objfile' which returns the objfile the
240 ** The frame information printed by the python frame filtering code
241 is now consistent with what the 'backtrace' command prints when
242 there are no filters, or when the 'backtrace' '-no-filters' option
245 ** The new function gdb.lookup_static_symbol can be used to look up
246 symbols with static linkage.
248 ** The new function gdb.lookup_static_symbols can be used to look up
249 all static symbols with static linkage.
251 ** gdb.Objfile has new methods 'lookup_global_symbol' and
252 'lookup_static_symbol' to lookup a symbol from this objfile only.
254 ** gdb.Block now supports the dictionary syntax for accessing symbols in
255 this block (e.g. block['local_variable']).
259 | [COMMAND] | SHELL_COMMAND
260 | -d DELIM COMMAND DELIM SHELL_COMMAND
261 pipe [COMMAND] | SHELL_COMMAND
262 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
263 Executes COMMAND and sends its output to SHELL_COMMAND.
264 With no COMMAND, repeat the last executed command
265 and send its output to SHELL_COMMAND.
267 define-prefix COMMAND
268 Define or mark a command as a user-defined prefix command.
270 with SETTING [VALUE] [-- COMMAND]
271 w SETTING [VALUE] [-- COMMAND]
272 Temporarily set SETTING, run COMMAND, and restore SETTING.
273 Usage: with SETTING -- COMMAND
274 With no COMMAND, repeats the last executed command.
275 SETTING is any GDB setting you can change with the "set"
276 subcommands. For example, 'with language c -- print someobj'
277 temporarily switches to the C language in order to print someobj.
278 Settings can be combined: 'w lang c -- w print elements unlimited --
279 usercmd' switches to the C language and runs usercmd with no limit
280 of array elements to print.
282 maint with SETTING [VALUE] [-- COMMAND]
283 Like "with", but works with "maintenance set" settings.
285 set may-call-functions [on|off]
286 show may-call-functions
287 This controls whether GDB will attempt to call functions in
288 the program, such as with expressions in the print command. It
289 defaults to on. Calling functions in the program being debugged
290 can have undesired side effects. It is now possible to forbid
291 such function calls. If function calls are forbidden, GDB will throw
292 an error when a command (such as print expression) calls a function
295 set print finish [on|off]
297 This controls whether the `finish' command will display the value
298 that is returned by the current function. When `off', the value is
299 still entered into the value history, but it is not printed. The
304 Allows deeply nested structures to be simplified when printing by
305 replacing deeply nested parts (beyond the max-depth) with ellipses.
306 The default max-depth is 20, but this can be set to unlimited to get
307 the old behavior back.
309 set print raw-values [on|off]
310 show print raw-values
311 By default, GDB applies the enabled pretty printers when printing a
312 value. This allows to ignore the enabled pretty printers for a series
313 of commands. The default is 'off'.
315 set logging debugredirect [on|off]
316 By default, GDB debug output will go to both the terminal and the logfile.
317 Set if you want debug output to go only to the log file.
319 set style title foreground COLOR
320 set style title background COLOR
321 set style title intensity VALUE
322 Control the styling of titles.
324 set style highlight foreground COLOR
325 set style highlight background COLOR
326 set style highlight intensity VALUE
327 Control the styling of highlightings.
329 maint set worker-threads
330 maint show worker-threads
331 Control the number of worker threads that can be used by GDB. The
332 default is 0. "unlimited" lets GDB choose a number that is
333 reasonable. Currently worker threads are only used when demangling
334 the names of linker symbols.
336 set style tui-border foreground COLOR
337 set style tui-border background COLOR
338 Control the styling of TUI borders.
340 set style tui-active-border foreground COLOR
341 set style tui-active-border background COLOR
342 Control the styling of the active TUI border.
344 maint set test-settings KIND
345 maint show test-settings KIND
346 A set of commands used by the testsuite for exercising the settings
349 maint set tui-resize-message [on|off]
350 maint show tui-resize-message
351 Control whether GDB prints a message each time the terminal is
352 resized when in TUI mode. This is primarily useful for testing the
355 set print frame-info [short-location|location|location-and-address
356 |source-and-location|source-line|auto]
357 show print frame-info
358 This controls what frame information is printed by the commands printing
359 a frame. This setting will e.g. influence the behaviour of 'backtrace',
360 'frame', 'stepi'. The python frame filtering also respect this setting.
361 The 'backtrace' '-frame-info' option can override this global setting.
363 set tui compact-source
364 show tui compact-source
366 Enable the "compact" display mode for the TUI source window. The
367 compact display uses only as much space as is needed for the line
368 numbers in the current file, and only a single space to separate the
369 line numbers from the source.
371 info modules [-q] [REGEXP]
372 Return a list of Fortran modules matching REGEXP, or all modules if
375 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
376 Return a list of functions within all modules, grouped by module.
377 The list of functions can be restricted with the optional regular
378 expressions. MODULE_REGEXP matches against the module name,
379 TYPE_REGEXP matches against the function type signature, and REGEXP
380 matches against the function name.
382 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
383 Return a list of variables within all modules, grouped by module.
384 The list of variables can be restricted with the optional regular
385 expressions. MODULE_REGEXP matches against the module name,
386 TYPE_REGEXP matches against the variable type, and REGEXP matches
387 against the variable name.
389 set debug remote-packet-max-chars
390 show debug remote-packet-max-chars
391 Controls the number of characters to output in a remote packet when using
393 The default is 512 bytes.
396 Lists the target connections currently in use.
401 The "help" command uses the title style to enhance the
402 readibility of its output by styling the classes and
406 Similarly to "help", the "apropos" command also uses the
407 title style for the command names. "apropos" accepts now
408 a flag "-v" (verbose) to show the full documentation
409 of matching commands and to use the highlight style to mark
410 the documentation parts matching REGEXP.
414 The GDB printf and eval commands can now print C-style and Ada-style
415 string convenience variables without calling functions in the program.
416 This allows to do formatted printing of strings without having
417 a running inferior, or when debugging a core dump.
419 info sources [-dirname | -basename] [--] [REGEXP]
420 This command has now optional arguments to only print the files
421 whose names match REGEXP. The arguments -dirname and -basename
422 allow to restrict matching respectively to the dirname and basename
426 The "show style" and its subcommands are now styling
427 a style name in their output using its own style, to help
428 the user visualize the different styles.
430 set print frame-arguments
431 The new value 'presence' indicates to only indicate the presence of
432 arguments using ..., instead of printing argument names and values.
434 set print raw-frame-arguments
435 show print raw-frame-arguments
437 These commands replace the similarly-named "set/show print raw
438 frame-arguments" commands (now with a dash instead of a space). The
439 old commands are now deprecated and may be removed in a future
442 add-inferior [-no-connection]
443 The add-inferior command now supports a "-no-connection" flag that
444 makes the new inferior start with no target connection associated.
445 By default, the new inferior inherits the target connection of the
446 current inferior. See also "info connections".
449 This command's output now includes a new "Connection" column
450 indicating which target connection an inferior is bound to. See
451 "info connections" above.
453 maint test-options require-delimiter
454 maint test-options unknown-is-error
455 maint test-options unknown-is-operand
456 maint show test-options-completion-result
457 Commands used by the testsuite to validate the command options
460 focus, winheight, +, -, >, <
461 These commands are now case-sensitive.
463 * New command options, command completion
465 GDB now has a standard infrastructure to support dash-style command
466 options ('-OPT'). One benefit is that commands that use it can
467 easily support completion of command line arguments. Try "CMD
468 -[TAB]" or "help CMD" to find options supported by a command. Over
469 time, we intend to migrate most commands to this infrastructure. A
470 number of commands got support for new command options in this
473 ** The "print" and "compile print" commands now support a number of
474 options that allow overriding relevant global print settings as
475 set by "set print" subcommands:
479 -array-indexes [on|off]
480 -elements NUMBER|unlimited
485 -repeats NUMBER|unlimited
486 -static-members [on|off]
491 Note that because the "print"/"compile print" commands accept
492 arbitrary expressions which may look like options (including
493 abbreviations), if you specify any command option, then you must
494 use a double dash ("--") to mark the end of argument processing.
496 ** The "backtrace" command now supports a number of options that
497 allow overriding relevant global print settings as set by "set
498 backtrace" and "set print" subcommands:
500 -entry-values no|only|preferred|if-needed|both|compact|default
501 -frame-arguments all|scalars|none
502 -raw-frame-arguments [on|off]
503 -frame-info auto|source-line|location|source-and-location
504 |location-and-address|short-location
508 In addition, the full/no-filters/hide qualifiers are now also
509 exposed as command options too:
515 ** The "frame apply", "tfaas" and "faas" commands similarly now
516 support the following options:
521 ** The new "info sources" options -dirname and -basename options
522 are using the standard '-OPT' infrastructure.
524 All options above can also be abbreviated. The argument of boolean
525 (on/off) options can be 0/1 too, and also the argument is assumed
526 "on" if omitted. This allows writing compact command invocations,
529 (gdb) p -ra -p -o 0 -- *myptr
531 The above is equivalent to:
533 (gdb) print -raw-values -pretty -object off -- *myptr
535 ** The "info types" command now supports the '-q' flag to disable
536 printing of some header information in a similar fashion to "info
537 variables" and "info functions".
539 ** The "info variables", "info functions", and "whereis" commands
540 now take a '-n' flag that excludes non-debug symbols (symbols
541 from the symbol table, not from the debug info such as DWARF)
544 * Completion improvements
546 ** GDB can now complete the options of the "thread apply all" and
547 "taas" commands, and their "-ascending" option can now be
550 ** GDB can now complete the options of the "info threads", "info
551 functions", "info variables", "info locals", and "info args"
554 ** GDB can now complete the options of the "compile file" and
555 "compile code" commands. The "compile file" command now
556 completes on filenames.
558 ** GDB can now complete the backtrace command's
559 "full/no-filters/hide" qualifiers.
561 * In settings, you can now abbreviate "unlimited".
563 E.g., "set print elements u" is now equivalent to "set print
569 This lists all the possible completions for the rest of the line, if it
570 were to be given as a command itself. This is intended for use by MI
571 frontends in cases when separate CLI and MI channels cannot be used.
573 -catch-throw, -catch-rethrow, and -catch-catch
574 These can be used to catch C++ exceptions in a similar fashion to
575 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
577 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
578 These commands are the MI equivalent of the CLI commands 'info
579 functions', 'info types', and 'info variables' respectively.
581 -symbol-info-modules, this is the MI equivalent of the CLI 'info
584 -symbol-info-module-functions and -symbol-info-module-variables.
585 These commands are the MI equivalent of the CLI commands 'info
586 module functions' and 'info module variables'.
590 ** The default version of the MI interpreter is now 3 (-i=mi3).
592 ** The output of information about multi-location breakpoints (which is
593 syntactically incorrect in MI 2) has changed in MI 3. This affects
594 the following commands and events:
598 - =breakpoint-created
599 - =breakpoint-modified
601 The -fix-multi-location-breakpoint-output command can be used to enable
602 this behavior with previous MI versions.
604 ** Backtraces and frames include a new optional field addr_flags which is
605 given after the addr field. On AArch64 this contains PAC if the address
606 has been masked in the frame. On all other targets the field is not
611 The testsuite now creates the files gdb.cmd (containing the arguments
612 used to launch GDB) and gdb.in (containing all the commands sent to
613 GDB) in the output directory for each test script. Multiple invocations
614 are appended with .1, .2, .3 etc.
616 * Building GDB and GDBserver now requires GNU make >= 3.82.
618 Using another implementation of the make program or an earlier version of
619 GNU make to build GDB or GDBserver is not supported.
621 * Building GDB now requires GNU readline >= 7.0.
623 GDB now bundles GNU readline 8.0, but if you choose to use
624 --with-system-readline, only readline >= 7.0 can be used.
626 * The TUI SingleKey keymap is now named "SingleKey". This can be used
627 from .inputrc to bind keys in this keymap. This feature is only
628 available when gdb is built against GNU readline 8.0 or later.
630 * Removed targets and native configurations
632 GDB no longer supports debugging the Cell Broadband Engine. This includes
633 both debugging standalone Cell/B.E. SPU applications and integrated debugging
634 of Cell/B.E. applications that use both the PPU and SPU architectures.
640 * Removed targets and native configurations
642 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
645 *** Changes in GDB 8.3
647 * GDB and GDBserver now support access to additional registers on
648 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
651 * GDB now has experimental support for the compilation and injection of
652 C++ source code into the inferior. This beta release does not include
653 support for several language features, such as templates, constructors,
656 This feature requires GCC 7.1 or higher built with libcp1.so
659 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
660 can be passed using the '[ADDRESS]:PORT' notation, or the regular
661 'ADDRESS:PORT' method.
663 * DWARF index cache: GDB can now automatically save indices of DWARF
664 symbols on disk to speed up further loading of the same binaries.
666 * Ada task switching is now supported on aarch64-elf targets when
667 debugging a program using the Ravenscar Profile. For more information,
668 see the "Tasking Support when using the Ravenscar Profile" section
669 in the GDB user manual.
671 * GDB in batch mode now exits with status 1 if the last command to be
674 * The RISC-V target now supports target descriptions.
676 * System call catchpoints now support system call aliases on FreeBSD.
677 When the ABI of a system call changes in FreeBSD, this is
678 implemented by leaving a compatibility system call using the old ABI
679 at the existing number and allocating a new system call number for
680 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
681 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
682 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
683 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
684 so that a system call catchpoint for the 'kevent' system call will
685 catch invocations of both the 'kevent' and 'freebsd11_kevent'
686 binaries. This ensures that 'kevent' system calls are caught for
687 binaries using either the old or new ABIs.
689 * Terminal styling is now available for the CLI and the TUI. GNU
690 Source Highlight can additionally be used to provide styling of
691 source code snippets. See the "set style" commands, below, for more
694 * Removed support for old demangling styles arm, edg, gnu, hp and
699 set debug compile-cplus-types
700 show debug compile-cplus-types
701 Control the display of debug output about type conversion in the
702 C++ compile feature. Commands have no effect while compiling
707 Control whether debug output about files/functions skipping is
710 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
711 Apply a command to some frames.
712 FLAG arguments allow to control what output to produce and how to handle
713 errors raised when applying COMMAND to a frame.
716 Apply a command to all threads (ignoring errors and empty output).
717 Shortcut for 'thread apply all -s COMMAND'.
720 Apply a command to all frames (ignoring errors and empty output).
721 Shortcut for 'frame apply all -s COMMAND'.
724 Apply a command to all frames of all threads (ignoring errors and empty
726 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
728 maint set dwarf unwinders (on|off)
729 maint show dwarf unwinders
730 Control whether DWARF unwinders can be used.
733 Display a list of open files for a process.
737 Changes to the "frame", "select-frame", and "info frame" CLI commands.
738 These commands all now take a frame specification which
739 is either a frame level, or one of the keywords 'level', 'address',
740 'function', or 'view' followed by a parameter. Selecting a frame by
741 address, or viewing a frame outside the current backtrace now
742 requires the use of a keyword. Selecting a frame by level is
743 unchanged. The MI comment "-stack-select-frame" is unchanged.
745 target remote FILENAME
746 target extended-remote FILENAME
747 If FILENAME is a Unix domain socket, GDB will attempt to connect
748 to this socket instead of opening FILENAME as a character device.
750 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
751 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
752 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
753 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
754 These commands can now print only the searched entities
755 matching the provided regexp(s), giving a condition
756 on the entity names or entity types. The flag -q disables
757 printing headers or informations messages.
763 These commands now determine the syntax for the shown entities
764 according to the language chosen by `set language'. In particular,
765 `set language auto' means to automatically choose the language of
768 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
769 The 'thread apply' command accepts new FLAG arguments.
770 FLAG arguments allow to control what output to produce and how to handle
771 errors raised when applying COMMAND to a thread.
773 set tui tab-width NCHARS
774 show tui tab-width NCHARS
775 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
777 set style enabled [on|off]
779 Enable or disable terminal styling. Styling is enabled by default
780 on most hosts, but disabled by default when in batch mode.
782 set style sources [on|off]
784 Enable or disable source code styling. Source code styling is
785 enabled by default, but only takes effect if styling in general is
786 enabled, and if GDB was linked with GNU Source Highlight.
788 set style filename foreground COLOR
789 set style filename background COLOR
790 set style filename intensity VALUE
791 Control the styling of file names.
793 set style function foreground COLOR
794 set style function background COLOR
795 set style function intensity VALUE
796 Control the styling of function names.
798 set style variable foreground COLOR
799 set style variable background COLOR
800 set style variable intensity VALUE
801 Control the styling of variable names.
803 set style address foreground COLOR
804 set style address background COLOR
805 set style address intensity VALUE
806 Control the styling of addresses.
810 ** The '-data-disassemble' MI command now accepts an '-a' option to
811 disassemble the whole function surrounding the given program
812 counter value or function name. Support for this feature can be
813 verified by using the "-list-features" command, which should
814 contain "data-disassemble-a-option".
816 ** Command responses and notifications that include a frame now include
817 the frame's architecture in a new "arch" attribute.
819 * New native configurations
821 GNU/Linux/RISC-V riscv*-*-linux*
822 FreeBSD/riscv riscv*-*-freebsd*
826 GNU/Linux/RISC-V riscv*-*-linux*
828 CSKY GNU/LINUX csky*-*-linux
829 FreeBSD/riscv riscv*-*-freebsd*
831 GNU/Linux/OpenRISC or1k*-*-linux*
835 GDB no longer supports native debugging on versions of MS-Windows
840 ** GDB no longer supports Python versions less than 2.6.
842 ** The gdb.Inferior type has a new 'progspace' property, which is the program
843 space associated to that inferior.
845 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
846 of objfiles associated to that program space.
848 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
849 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
852 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
853 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
854 correct and did not work properly.
856 ** The gdb.Value type has a new constructor, which is used to construct a
857 gdb.Value from a Python buffer object and a gdb.Type.
863 Enable or disable the undefined behavior sanitizer. This is
864 disabled by default, but passing --enable-ubsan=yes or
865 --enable-ubsan=auto to configure will enable it. Enabling this can
866 cause a performance penalty. The undefined behavior sanitizer was
867 first introduced in GCC 4.9.
869 *** Changes in GDB 8.2
871 * The 'set disassembler-options' command now supports specifying options
874 * The 'symbol-file' command now accepts an '-o' option to add a relative
875 offset to all sections.
877 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
878 a relative offset to all sections, but it allows to override the load
879 address of individual sections using '-s'.
881 * The 'add-symbol-file' command no longer requires the second argument
882 (address of the text section).
884 * The endianness used with the 'set endian auto' mode in the absence of
885 an executable selected for debugging is now the last endianness chosen
886 either by one of the 'set endian big' and 'set endian little' commands
887 or by inferring from the last executable used, rather than the startup
890 * The pager now allows a "c" response, meaning to disable the pager
891 for the rest of the current command.
893 * The commands 'info variables/functions/types' now show the source line
894 numbers of symbol definitions when available.
896 * 'info proc' now works on running processes on FreeBSD systems and core
897 files created on FreeBSD systems.
899 * C expressions can now use _Alignof, and C++ expressions can now use
902 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
903 the vector length while the process is running.
909 Control display of debugging info regarding the FreeBSD native target.
911 set|show varsize-limit
912 This new setting allows the user to control the maximum size of Ada
913 objects being printed when those objects have a variable type,
914 instead of that maximum size being hardcoded to 65536 bytes.
916 set|show record btrace cpu
917 Controls the processor to be used for enabling errata workarounds for
920 maint check libthread-db
921 Run integrity checks on the current inferior's thread debugging
924 maint set check-libthread-db (on|off)
925 maint show check-libthread-db
926 Control whether to run integrity checks on inferior specific thread
927 debugging libraries as they are loaded. The default is not to
932 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
934 ** The commands attached to a breakpoint can be set by assigning to
935 the breakpoint's "commands" field.
937 ** gdb.execute can now execute multi-line gdb commands.
939 ** The new functions gdb.convenience_variable and
940 gdb.set_convenience_variable can be used to get and set the value
941 of convenience variables.
943 ** A gdb.Parameter will no longer print the "set" help text on an
944 ordinary "set"; instead by default a "set" will be silent unless
945 the get_set_string method returns a non-empty string.
949 RiscV ELF riscv*-*-elf
951 * Removed targets and native configurations
953 m88k running OpenBSD m88*-*-openbsd*
954 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
955 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
956 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
958 * Aarch64/Linux hardware watchpoints improvements
960 Hardware watchpoints on unaligned addresses are now properly
961 supported when running Linux kernel 4.10 or higher: read and access
962 watchpoints are no longer spuriously missed, and all watchpoints
963 lengths between 1 and 8 bytes are supported. On older kernels,
964 watchpoints set on unaligned addresses are no longer missed, with
965 the tradeoff that there is a possibility of false hits being
970 --enable-codesign=CERT
971 This can be used to invoke "codesign -s CERT" after building gdb.
972 This option is useful on macOS, where code signing is required for
973 gdb to work properly.
975 --disable-gdbcli has been removed
976 This is now silently accepted, but does nothing.
978 *** Changes in GDB 8.1
980 * GDB now supports dynamically creating arbitrary register groups specified
981 in XML target descriptions. This allows for finer grain grouping of
982 registers on systems with a large amount of registers.
984 * The 'ptype' command now accepts a '/o' flag, which prints the
985 offsets and sizes of fields in a struct, like the pahole(1) tool.
987 * New "--readnever" command line option instructs GDB to not read each
988 symbol file's symbolic debug information. This makes startup faster
989 but at the expense of not being able to perform symbolic debugging.
990 This option is intended for use cases where symbolic debugging will
991 not be used, e.g., when you only need to dump the debuggee's core.
993 * GDB now uses the GNU MPFR library, if available, to emulate target
994 floating-point arithmetic during expression evaluation when the target
995 uses different floating-point formats than the host. At least version
996 3.1 of GNU MPFR is required.
998 * GDB now supports access to the guarded-storage-control registers and the
999 software-based guarded-storage broadcast control registers on IBM z14.
1001 * On Unix systems, GDB now supports transmitting environment variables
1002 that are to be set or unset to GDBserver. These variables will
1003 affect the environment to be passed to the remote inferior.
1005 To inform GDB of environment variables that are to be transmitted to
1006 GDBserver, use the "set environment" command. Only user set
1007 environment variables are sent to GDBserver.
1009 To inform GDB of environment variables that are to be unset before
1010 the remote inferior is started by the GDBserver, use the "unset
1011 environment" command.
1013 * Completion improvements
1015 ** GDB can now complete function parameters in linespecs and
1016 explicit locations without quoting. When setting breakpoints,
1017 quoting around functions names to help with TAB-completion is
1018 generally no longer necessary. For example, this now completes
1021 (gdb) b function(in[TAB]
1022 (gdb) b function(int)
1024 Related, GDB is no longer confused with completing functions in
1025 C++ anonymous namespaces:
1028 (gdb) b (anonymous namespace)::[TAB][TAB]
1029 (anonymous namespace)::a_function()
1030 (anonymous namespace)::b_function()
1032 ** GDB now has much improved linespec and explicit locations TAB
1033 completion support, that better understands what you're
1034 completing and offers better suggestions. For example, GDB no
1035 longer offers data symbols as possible completions when you're
1036 setting a breakpoint.
1038 ** GDB now TAB-completes label symbol names.
1040 ** The "complete" command now mimics TAB completion accurately.
1042 * New command line options (gcore)
1045 Dump all memory mappings.
1047 * Breakpoints on C++ functions are now set on all scopes by default
1049 By default, breakpoints on functions/methods are now interpreted as
1050 specifying all functions with the given name ignoring missing
1051 leading scopes (namespaces and classes).
1053 For example, assuming a C++ program with symbols named:
1058 both commands "break func()" and "break B::func()" set a breakpoint
1061 You can use the new flag "-qualified" to override this. This makes
1062 GDB interpret the specified function name as a complete
1063 fully-qualified name instead. For example, using the same C++
1064 program, the "break -q B::func" command sets a breakpoint on
1065 "B::func", only. A parameter has been added to the Python
1066 gdb.Breakpoint constructor to achieve the same result when creating
1067 a breakpoint from Python.
1069 * Breakpoints on functions marked with C++ ABI tags
1071 GDB can now set breakpoints on functions marked with C++ ABI tags
1072 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1073 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1075 Functions with a C++11 abi tag are demangled/displayed like this:
1077 function[abi:cxx11](int)
1080 You can now set a breakpoint on such functions simply as if they had
1083 (gdb) b function(int)
1085 Or if you need to disambiguate between tags, like:
1087 (gdb) b function[abi:other_tag](int)
1089 Tab completion was adjusted accordingly as well.
1093 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1094 gdb.new_thread are emitted. See the manual for further
1095 description of these.
1097 ** A new function, "gdb.rbreak" has been added to the Python API.
1098 This function allows the setting of a large number of breakpoints
1099 via a regex pattern in Python. See the manual for further details.
1101 ** Python breakpoints can now accept explicit locations. See the
1102 manual for a further description of this feature.
1105 * New features in the GDB remote stub, GDBserver
1107 ** GDBserver is now able to start inferior processes with a
1108 specified initial working directory.
1110 The user can set the desired working directory to be used from
1111 GDB using the new "set cwd" command.
1113 ** New "--selftest" command line option runs some GDBserver self
1114 tests. These self tests are disabled in releases.
1116 ** On Unix systems, GDBserver now does globbing expansion and variable
1117 substitution in inferior command line arguments.
1119 This is done by starting inferiors using a shell, like GDB does.
1120 See "set startup-with-shell" in the user manual for how to disable
1121 this from GDB when using "target extended-remote". When using
1122 "target remote", you can disable the startup with shell by using the
1123 new "--no-startup-with-shell" GDBserver command line option.
1125 ** On Unix systems, GDBserver now supports receiving environment
1126 variables that are to be set or unset from GDB. These variables
1127 will affect the environment to be passed to the inferior.
1129 * When catching an Ada exception raised with a message, GDB now prints
1130 the message in the catchpoint hit notification. In GDB/MI mode, that
1131 information is provided as an extra field named "exception-message"
1132 in the *stopped notification.
1134 * Trait objects can now be inspected When debugging Rust code. This
1135 requires compiler support which will appear in Rust 1.24.
1137 * New remote packets
1139 QEnvironmentHexEncoded
1140 Inform GDBserver of an environment variable that is to be passed to
1141 the inferior when starting it.
1144 Inform GDBserver of an environment variable that is to be unset
1145 before starting the remote inferior.
1148 Inform GDBserver that the environment should be reset (i.e.,
1149 user-set environment variables should be unset).
1152 Indicates whether the inferior must be started with a shell or not.
1155 Tell GDBserver that the inferior to be started should use a specific
1158 * The "maintenance print c-tdesc" command now takes an optional
1159 argument which is the file name of XML target description.
1161 * The "maintenance selftest" command now takes an optional argument to
1162 filter the tests to be run.
1164 * The "enable", and "disable" commands now accept a range of
1165 breakpoint locations, e.g. "enable 1.3-5".
1170 Set and show the current working directory for the inferior.
1172 set|show compile-gcc
1173 Set and show compilation command used for compiling and injecting code
1174 with the 'compile' commands.
1176 set debug separate-debug-file
1177 show debug separate-debug-file
1178 Control the display of debug output about separate debug file search.
1180 set dump-excluded-mappings
1181 show dump-excluded-mappings
1182 Control whether mappings marked with the VM_DONTDUMP flag should be
1183 dumped when generating a core file.
1185 maint info selftests
1186 List the registered selftests.
1189 Start the debugged program stopping at the first instruction.
1192 Control display of debugging messages related to OpenRISC targets.
1194 set|show print type nested-type-limit
1195 Set and show the limit of nesting level for nested types that the
1196 type printer will show.
1198 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1201 * Safer/improved support for debugging with no debug info
1203 GDB no longer assumes functions with no debug information return
1206 This means that GDB now refuses to call such functions unless you
1207 tell it the function's type, by either casting the call to the
1208 declared return type, or by casting the function to a function
1209 pointer of the right type, and calling that:
1211 (gdb) p getenv ("PATH")
1212 'getenv' has unknown return type; cast the call to its declared return type
1213 (gdb) p (char *) getenv ("PATH")
1214 $1 = 0x7fffffffe "/usr/local/bin:/"...
1215 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1216 $2 = 0x7fffffffe "/usr/local/bin:/"...
1218 Similarly, GDB no longer assumes that global variables with no debug
1219 info have type 'int', and refuses to print the variable's value
1220 unless you tell it the variable's type:
1223 'var' has unknown type; cast it to its declared type
1227 * New native configurations
1229 FreeBSD/aarch64 aarch64*-*-freebsd*
1230 FreeBSD/arm arm*-*-freebsd*
1234 FreeBSD/aarch64 aarch64*-*-freebsd*
1235 FreeBSD/arm arm*-*-freebsd*
1236 OpenRISC ELF or1k*-*-elf
1238 * Removed targets and native configurations
1240 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1242 *** Changes in GDB 8.0
1244 * GDB now supports access to the PKU register on GNU/Linux. The register is
1245 added by the Memory Protection Keys for Userspace feature which will be
1246 available in future Intel CPUs.
1248 * GDB now supports C++11 rvalue references.
1252 ** New functions to start, stop and access a running btrace recording.
1253 ** Rvalue references are now supported in gdb.Type.
1255 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1258 * Building GDB and GDBserver now requires a C++11 compiler.
1260 For example, GCC 4.8 or later.
1262 It is no longer possible to build GDB or GDBserver with a C
1263 compiler. The --disable-build-with-cxx configure option has been
1266 * Building GDB and GDBserver now requires GNU make >= 3.81.
1268 It is no longer supported to build GDB or GDBserver with another
1269 implementation of the make program or an earlier version of GNU make.
1271 * Native debugging on MS-Windows supports command-line redirection
1273 Command-line arguments used for starting programs on MS-Windows can
1274 now include redirection symbols supported by native Windows shells,
1275 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1276 as "run", "start", and "set args", as well as the corresponding MI
1279 * Support for thread names on MS-Windows.
1281 GDB now catches and handles the special exception that programs
1282 running on MS-Windows use to assign names to threads in the
1285 * Support for Java programs compiled with gcj has been removed.
1287 * User commands now accept an unlimited number of arguments.
1288 Previously, only up to 10 was accepted.
1290 * The "eval" command now expands user-defined command arguments.
1292 This makes it easier to process a variable number of arguments:
1297 eval "print $arg%d", $i
1302 * Target descriptions can now describe registers for sparc32 and sparc64.
1304 * GDB now supports DWARF version 5 (debug information format).
1305 Its .debug_names index is not yet supported.
1307 * New native configurations
1309 FreeBSD/mips mips*-*-freebsd
1313 Synopsys ARC arc*-*-elf32
1314 FreeBSD/mips mips*-*-freebsd
1316 * Removed targets and native configurations
1318 Alpha running FreeBSD alpha*-*-freebsd*
1319 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1324 Erases all the flash memory regions reported by the target.
1326 maint print arc arc-instruction address
1327 Print internal disassembler information about instruction at a given address.
1331 set disassembler-options
1332 show disassembler-options
1333 Controls the passing of target specific information to the disassembler.
1334 If it is necessary to specify more than one disassembler option then
1335 multiple options can be placed together into a comma separated list.
1336 The default value is the empty string. Currently, the only supported
1337 targets are ARM, PowerPC and S/390.
1342 Erases all the flash memory regions reported by the target. This is
1343 equivalent to the CLI command flash-erase.
1345 -file-list-shared-libraries
1346 List the shared libraries in the program. This is
1347 equivalent to the CLI command "info shared".
1350 Catchpoints stopping the program when Ada exceptions are
1351 handled. This is equivalent to the CLI command "catch handlers".
1353 *** Changes in GDB 7.12
1355 * GDB and GDBserver now build with a C++ compiler by default.
1357 The --enable-build-with-cxx configure option is now enabled by
1358 default. One must now explicitly configure with
1359 --disable-build-with-cxx in order to build with a C compiler. This
1360 option will be removed in a future release.
1362 * GDBserver now supports recording btrace without maintaining an active
1365 * GDB now supports a negative repeat count in the 'x' command to examine
1366 memory backward from the given address. For example:
1369 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1370 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1371 (gdb) x/-5i 0x0000000000400580
1372 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1373 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1374 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1375 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1376 0x40057b <main(int, char**)+25>:
1377 callq 0x400536 <Func1(int, char const*)>
1379 * Fortran: Support structures with fields of dynamic types and
1380 arrays of dynamic types.
1382 * The symbol dumping maintenance commands have new syntax.
1383 maint print symbols [-pc address] [--] [filename]
1384 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1385 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1386 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1387 maint print msymbols [-objfile objfile] [--] [filename]
1389 * GDB now supports multibit bitfields and enums in target register
1392 * New Python-based convenience function $_as_string(val), which returns
1393 the textual representation of a value. This function is especially
1394 useful to obtain the text label of an enum value.
1396 * Intel MPX bound violation handling.
1398 Segmentation faults caused by a Intel MPX boundary violation
1399 now display the kind of violation (upper or lower), the memory
1400 address accessed and the memory bounds, along with the usual
1401 signal received and code location.
1405 Program received signal SIGSEGV, Segmentation fault
1406 Upper bound violation while accessing address 0x7fffffffc3b3
1407 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1408 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1410 * Rust language support.
1411 GDB now supports debugging programs written in the Rust programming
1412 language. See https://www.rust-lang.org/ for more information about
1415 * Support for running interpreters on specified input/output devices
1417 GDB now supports a new mechanism that allows frontends to provide
1418 fully featured GDB console views, as a better alternative to
1419 building such views on top of the "-interpreter-exec console"
1420 command. See the new "new-ui" command below. With that command,
1421 frontends can now start GDB in the traditional command-line mode
1422 running in an embedded terminal emulator widget, and create a
1423 separate MI interpreter running on a specified i/o device. In this
1424 way, GDB handles line editing, history, tab completion, etc. in the
1425 console all by itself, and the GUI uses the separate MI interpreter
1426 for its own control and synchronization, invisible to the command
1429 * The "catch syscall" command catches groups of related syscalls.
1431 The "catch syscall" command now supports catching a group of related
1432 syscalls using the 'group:' or 'g:' prefix.
1437 skip -gfile file-glob-pattern
1438 skip -function function
1439 skip -rfunction regular-expression
1440 A generalized form of the skip command, with new support for
1441 glob-style file names and regular expressions for function names.
1442 Additionally, a file spec and a function spec may now be combined.
1444 maint info line-table REGEXP
1445 Display the contents of GDB's internal line table data structure.
1448 Run any GDB unit tests that were compiled in.
1451 Start a new user interface instance running INTERP as interpreter,
1452 using the TTY file for input/output.
1456 ** gdb.Breakpoint objects have a new attribute "pending", which
1457 indicates whether the breakpoint is pending.
1458 ** Three new breakpoint-related events have been added:
1459 gdb.breakpoint_created, gdb.breakpoint_modified, and
1460 gdb.breakpoint_deleted.
1462 signal-event EVENTID
1463 Signal ("set") the given MS-Windows event object. This is used in
1464 conjunction with the Windows JIT debugging (AeDebug) support, where
1465 the OS suspends a crashing process until a debugger can attach to
1466 it. Resuming the crashing process, in order to debug it, is done by
1467 signalling an event.
1469 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1470 was added in GDBserver, including JIT compiling fast tracepoint's
1471 conditional expression bytecode into native code.
1473 * Support for various remote target protocols and ROM monitors has
1476 target m32rsdi Remote M32R debugging over SDI
1477 target mips MIPS remote debugging protocol
1478 target pmon PMON ROM monitor
1479 target ddb NEC's DDB variant of PMON for Vr4300
1480 target rockhopper NEC RockHopper variant of PMON
1481 target lsi LSI variant of PMO
1483 * Support for tracepoints and fast tracepoints on powerpc-linux,
1484 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1485 including JIT compiling fast tracepoint's conditional expression
1486 bytecode into native code.
1488 * MI async record =record-started now includes the method and format used for
1489 recording. For example:
1491 =record-started,thread-group="i1",method="btrace",format="bts"
1493 * MI async record =thread-selected now includes the frame field. For example:
1495 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1499 Andes NDS32 nds32*-*-elf
1501 *** Changes in GDB 7.11
1503 * GDB now supports debugging kernel-based threads on FreeBSD.
1505 * Per-inferior thread numbers
1507 Thread numbers are now per inferior instead of global. If you're
1508 debugging multiple inferiors, GDB displays thread IDs using a
1509 qualified INF_NUM.THR_NUM form. For example:
1513 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1514 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1515 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1516 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1518 As consequence, thread numbers as visible in the $_thread
1519 convenience variable and in Python's InferiorThread.num attribute
1520 are no longer unique between inferiors.
1522 GDB now maintains a second thread ID per thread, referred to as the
1523 global thread ID, which is the new equivalent of thread numbers in
1524 previous releases. See also $_gthread below.
1526 For backwards compatibility, MI's thread IDs always refer to global
1529 * Commands that accept thread IDs now accept the qualified
1530 INF_NUM.THR_NUM form as well. For example:
1533 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1536 * In commands that accept a list of thread IDs, you can now refer to
1537 all threads of an inferior using a star wildcard. GDB accepts
1538 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1539 refer to all threads of the current inferior. For example, "info
1542 * You can use "info threads -gid" to display the global thread ID of
1545 * The new convenience variable $_gthread holds the global number of
1548 * The new convenience variable $_inferior holds the number of the
1551 * GDB now displays the ID and name of the thread that hit a breakpoint
1552 or received a signal, if your program is multi-threaded. For
1555 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1556 Thread 1 "main" received signal SIGINT, Interrupt.
1558 * Record btrace now supports non-stop mode.
1560 * Support for tracepoints on aarch64-linux was added in GDBserver.
1562 * The 'record instruction-history' command now indicates speculative execution
1563 when using the Intel Processor Trace recording format.
1565 * GDB now allows users to specify explicit locations, bypassing
1566 the linespec parser. This feature is also available to GDB/MI
1569 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1570 GDB now is able to debug both AArch64 applications and ARM applications
1573 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1574 including JIT compiling fast tracepoint's conditional expression bytecode
1577 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1579 * "info threads", "info inferiors", "info display", "info checkpoints"
1580 and "maint info program-spaces" now list the corresponding items in
1581 ascending ID order, for consistency with all other "info" commands.
1583 * In Ada, the overloads selection menu has been enhanced to display the
1584 parameter types and the return types for the matching overloaded subprograms.
1588 maint set target-non-stop (on|off|auto)
1589 maint show target-non-stop
1590 Control whether GDB targets always operate in non-stop mode even if
1591 "set non-stop" is "off". The default is "auto", meaning non-stop
1592 mode is enabled if supported by the target.
1594 maint set bfd-sharing
1595 maint show bfd-sharing
1596 Control the reuse of bfd objects.
1599 show debug bfd-cache
1600 Control display of debugging info regarding bfd caching.
1604 Control display of debugging info regarding FreeBSD threads.
1606 set remote multiprocess-extensions-packet
1607 show remote multiprocess-extensions-packet
1608 Set/show the use of the remote protocol multiprocess extensions.
1610 set remote thread-events
1611 show remote thread-events
1612 Set/show the use of thread create/exit events.
1614 set ada print-signatures on|off
1615 show ada print-signatures"
1616 Control whether parameter types and return types are displayed in overloads
1617 selection menus. It is activated (@code{on}) by default.
1621 Controls the maximum size of memory, in bytes, that GDB will
1622 allocate for value contents. Prevents incorrect programs from
1623 causing GDB to allocate overly large buffers. Default is 64k.
1625 * The "disassemble" command accepts a new modifier: /s.
1626 It prints mixed source+disassembly like /m with two differences:
1627 - disassembled instructions are now printed in program order, and
1628 - and source for all relevant files is now printed.
1629 The "/m" option is now considered deprecated: its "source-centric"
1630 output hasn't proved useful in practice.
1632 * The "record instruction-history" command accepts a new modifier: /s.
1633 It behaves exactly like /m and prints mixed source+disassembly.
1635 * The "set scheduler-locking" command supports a new mode "replay".
1636 It behaves like "off" in record mode and like "on" in replay mode.
1638 * Support for various ROM monitors has been removed:
1640 target dbug dBUG ROM monitor for Motorola ColdFire
1641 target picobug Motorola picobug monitor
1642 target dink32 DINK32 ROM monitor for PowerPC
1643 target m32r Renesas M32R/D ROM monitor
1644 target mon2000 mon2000 ROM monitor
1645 target ppcbug PPCBUG ROM monitor for PowerPC
1647 * Support for reading/writing memory and extracting values on architectures
1648 whose memory is addressable in units of any integral multiple of 8 bits.
1651 Allows to break when an Ada exception is handled.
1653 * New remote packets
1656 Indicates that an exec system call was executed.
1658 exec-events feature in qSupported
1659 The qSupported packet allows GDB to request support for exec
1660 events using the new 'gdbfeature' exec-event, and the qSupported
1661 response can contain the corresponding 'stubfeature'. Set and
1662 show commands can be used to display whether these features are enabled.
1665 Equivalent to interrupting with the ^C character, but works in
1668 thread created stop reason (T05 create:...)
1669 Indicates that the thread was just created and is stopped at entry.
1671 thread exit stop reply (w exitcode;tid)
1672 Indicates that the thread has terminated.
1675 Enables/disables thread create and exit event reporting. For
1676 example, this is used in non-stop mode when GDB stops a set of
1677 threads and synchronously waits for the their corresponding stop
1678 replies. Without exit events, if one of the threads exits, GDB
1679 would hang forever not knowing that it should no longer expect a
1680 stop for that same thread.
1683 Indicates that there are no resumed threads left in the target (all
1684 threads are stopped). The remote stub reports support for this stop
1685 reply to GDB's qSupported query.
1688 Enables/disables catching syscalls from the inferior process.
1689 The remote stub reports support for this packet to GDB's qSupported query.
1691 syscall_entry stop reason
1692 Indicates that a syscall was just called.
1694 syscall_return stop reason
1695 Indicates that a syscall just returned.
1697 * Extended-remote exec events
1699 ** GDB now has support for exec events on extended-remote Linux targets.
1700 For such targets with Linux kernels 2.5.46 and later, this enables
1701 follow-exec-mode and exec catchpoints.
1703 set remote exec-event-feature-packet
1704 show remote exec-event-feature-packet
1705 Set/show the use of the remote exec event feature.
1707 * Thread names in remote protocol
1709 The reply to qXfer:threads:read may now include a name attribute for each
1712 * Target remote mode fork and exec events
1714 ** GDB now has support for fork and exec events on target remote mode
1715 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1716 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1717 fork and exec catchpoints.
1719 * Remote syscall events
1721 ** GDB now has support for catch syscall on remote Linux targets,
1722 currently enabled on x86/x86_64 architectures.
1724 set remote catch-syscall-packet
1725 show remote catch-syscall-packet
1726 Set/show the use of the remote catch syscall feature.
1730 ** The -var-set-format command now accepts the zero-hexadecimal
1731 format. It outputs data in hexadecimal format with zero-padding on the
1736 ** gdb.InferiorThread objects have a new attribute "global_num",
1737 which refers to the thread's global thread ID. The existing
1738 "num" attribute now refers to the thread's per-inferior number.
1739 See "Per-inferior thread numbers" above.
1740 ** gdb.InferiorThread objects have a new attribute "inferior", which
1741 is the Inferior object the thread belongs to.
1743 *** Changes in GDB 7.10
1745 * Support for process record-replay and reverse debugging on aarch64*-linux*
1746 targets has been added. GDB now supports recording of A64 instruction set
1747 including advance SIMD instructions.
1749 * Support for Sun's version of the "stabs" debug file format has been removed.
1751 * GDB now honors the content of the file /proc/PID/coredump_filter
1752 (PID is the process ID) on GNU/Linux systems. This file can be used
1753 to specify the types of memory mappings that will be included in a
1754 corefile. For more information, please refer to the manual page of
1755 "core(5)". GDB also has a new command: "set use-coredump-filter
1756 on|off". It allows to set whether GDB will read the content of the
1757 /proc/PID/coredump_filter file when generating a corefile.
1759 * The "info os" command on GNU/Linux can now display information on
1761 "info os cpus" Listing of all cpus/cores on the system
1763 * GDB has two new commands: "set serial parity odd|even|none" and
1764 "show serial parity". These allows to set or show parity for the
1767 * The "info source" command now displays the producer string if it was
1768 present in the debug info. This typically includes the compiler version
1769 and may include things like its command line arguments.
1771 * The "info dll", an alias of the "info sharedlibrary" command,
1772 is now available on all platforms.
1774 * Directory names supplied to the "set sysroot" commands may be
1775 prefixed with "target:" to tell GDB to access shared libraries from
1776 the target system, be it local or remote. This replaces the prefix
1777 "remote:". The default sysroot has been changed from "" to
1778 "target:". "remote:" is automatically converted to "target:" for
1779 backward compatibility.
1781 * The system root specified by "set sysroot" will be prepended to the
1782 filename of the main executable (if reported to GDB as absolute by
1783 the operating system) when starting processes remotely, and when
1784 attaching to already-running local or remote processes.
1786 * GDB now supports automatic location and retrieval of executable
1787 files from remote targets. Remote debugging can now be initiated
1788 using only a "target remote" or "target extended-remote" command
1789 (no "set sysroot" or "file" commands are required). See "New remote
1792 * The "dump" command now supports verilog hex format.
1794 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1796 * On GNU/Linux, GDB and gdbserver are now able to access executable
1797 and shared library files without a "set sysroot" command when
1798 attaching to processes running in different mount namespaces from
1799 the debugger. This makes it possible to attach to processes in
1800 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1801 See "New remote packets" below.
1803 * The "tui reg" command now provides completion for all of the
1804 available register groups, including target specific groups.
1806 * The HISTSIZE environment variable is no longer read when determining
1807 the size of GDB's command history. GDB now instead reads the dedicated
1808 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1809 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1814 ** Memory ports can now be unbuffered.
1818 ** gdb.Objfile objects have a new attribute "username",
1819 which is the name of the objfile as specified by the user,
1820 without, for example, resolving symlinks.
1821 ** You can now write frame unwinders in Python.
1822 ** gdb.Type objects have a new method "optimized_out",
1823 returning optimized out gdb.Value instance of this type.
1824 ** gdb.Value objects have new methods "reference_value" and
1825 "const_value" which return a reference to the value and a
1826 "const" version of the value respectively.
1830 maint print symbol-cache
1831 Print the contents of the symbol cache.
1833 maint print symbol-cache-statistics
1834 Print statistics of symbol cache usage.
1836 maint flush-symbol-cache
1837 Flush the contents of the symbol cache.
1841 Start branch trace recording using Branch Trace Store (BTS) format.
1844 Evaluate expression by using the compiler and print result.
1848 Explicit commands for enabling and disabling tui mode.
1851 set mpx bound on i386 and amd64
1852 Support for bound table investigation on Intel MPX enabled applications.
1856 Start branch trace recording using Intel Processor Trace format.
1859 Print information about branch tracing internals.
1861 maint btrace packet-history
1862 Print the raw branch tracing data.
1864 maint btrace clear-packet-history
1865 Discard the stored raw branch tracing data.
1868 Discard all branch tracing data. It will be fetched and processed
1869 anew by the next "record" command.
1874 Renamed from "set debug dwarf2-die".
1875 show debug dwarf-die
1876 Renamed from "show debug dwarf2-die".
1878 set debug dwarf-read
1879 Renamed from "set debug dwarf2-read".
1880 show debug dwarf-read
1881 Renamed from "show debug dwarf2-read".
1883 maint set dwarf always-disassemble
1884 Renamed from "maint set dwarf2 always-disassemble".
1885 maint show dwarf always-disassemble
1886 Renamed from "maint show dwarf2 always-disassemble".
1888 maint set dwarf max-cache-age
1889 Renamed from "maint set dwarf2 max-cache-age".
1890 maint show dwarf max-cache-age
1891 Renamed from "maint show dwarf2 max-cache-age".
1893 set debug dwarf-line
1894 show debug dwarf-line
1895 Control display of debugging info regarding DWARF line processing.
1898 show max-completions
1899 Set the maximum number of candidates to be considered during
1900 completion. The default value is 200. This limit allows GDB
1901 to avoid generating large completion lists, the computation of
1902 which can cause the debugger to become temporarily unresponsive.
1904 set history remove-duplicates
1905 show history remove-duplicates
1906 Control the removal of duplicate history entries.
1908 maint set symbol-cache-size
1909 maint show symbol-cache-size
1910 Control the size of the symbol cache.
1912 set|show record btrace bts buffer-size
1913 Set and show the size of the ring buffer used for branch tracing in
1915 The obtained size may differ from the requested size. Use "info
1916 record" to see the obtained buffer size.
1918 set debug linux-namespaces
1919 show debug linux-namespaces
1920 Control display of debugging info regarding Linux namespaces.
1922 set|show record btrace pt buffer-size
1923 Set and show the size of the ring buffer used for branch tracing in
1924 Intel Processor Trace format.
1925 The obtained size may differ from the requested size. Use "info
1926 record" to see the obtained buffer size.
1928 maint set|show btrace pt skip-pad
1929 Set and show whether PAD packets are skipped when computing the
1932 * The command 'thread apply all' can now support new option '-ascending'
1933 to call its specified command for all threads in ascending order.
1935 * Python/Guile scripting
1937 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1938 special section named `.debug_gdb_scripts'.
1940 * New remote packets
1942 qXfer:btrace-conf:read
1943 Return the branch trace configuration for the current thread.
1945 Qbtrace-conf:bts:size
1946 Set the requested ring buffer size for branch tracing in BTS format.
1949 Enable Intel Processor Trace-based branch tracing for the current
1950 process. The remote stub reports support for this packet to GDB's
1953 Qbtrace-conf:pt:size
1954 Set the requested ring buffer size for branch tracing in Intel Processor
1958 Indicates a memory breakpoint instruction was executed, irrespective
1959 of whether it was GDB that planted the breakpoint or the breakpoint
1960 is hardcoded in the program. This is required for correct non-stop
1964 Indicates the target stopped for a hardware breakpoint. This is
1965 required for correct non-stop mode operation.
1968 Return information about files on the remote system.
1970 qXfer:exec-file:read
1971 Return the full absolute name of the file that was executed to
1972 create a process running on the remote system.
1975 Select the filesystem on which vFile: operations with filename
1976 arguments will operate. This is required for GDB to be able to
1977 access files on remote targets where the remote stub does not
1978 share a common filesystem with the inferior(s).
1981 Indicates that a fork system call was executed.
1984 Indicates that a vfork system call was executed.
1986 vforkdone stop reason
1987 Indicates that a vfork child of the specified process has executed
1988 an exec or exit, allowing the vfork parent to resume execution.
1990 fork-events and vfork-events features in qSupported
1991 The qSupported packet allows GDB to request support for fork and
1992 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1993 and the qSupported response can contain the corresponding
1994 'stubfeatures'. Set and show commands can be used to display
1995 whether these features are enabled.
1997 * Extended-remote fork events
1999 ** GDB now has support for fork events on extended-remote Linux
2000 targets. For targets with Linux kernels 2.5.60 and later, this
2001 enables follow-fork-mode and detach-on-fork for both fork and
2002 vfork, as well as fork and vfork catchpoints.
2004 * The info record command now shows the recording format and the
2005 branch tracing configuration for the current thread when using
2006 the btrace record target.
2007 For the BTS format, it shows the ring buffer size.
2009 * GDB now has support for DTrace USDT (Userland Static Defined
2010 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2012 * GDB now supports access to vector registers on S/390 GNU/Linux
2015 * Removed command line options
2017 -xdb HP-UX XDB compatibility mode.
2019 * Removed targets and native configurations
2021 HP/PA running HP-UX hppa*-*-hpux*
2022 Itanium running HP-UX ia64-*-hpux*
2024 * New configure options
2027 This configure option allows the user to build GDB with support for
2028 Intel Processor Trace (default: auto). This requires libipt.
2030 --with-libipt-prefix=PATH
2031 Specify the path to the version of libipt that GDB should use.
2032 $PATH/include should contain the intel-pt.h header and
2033 $PATH/lib should contain the libipt.so library.
2035 *** Changes in GDB 7.9.1
2039 ** Xmethods can now specify a result type.
2041 *** Changes in GDB 7.9
2043 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2047 ** You can now access frame registers from Python scripts.
2048 ** New attribute 'producer' for gdb.Symtab objects.
2049 ** gdb.Objfile objects have a new attribute "progspace",
2050 which is the gdb.Progspace object of the containing program space.
2051 ** gdb.Objfile objects have a new attribute "owner".
2052 ** gdb.Objfile objects have a new attribute "build_id",
2053 which is the build ID generated when the file was built.
2054 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2055 ** A new event "gdb.clear_objfiles" has been added, triggered when
2056 selecting a new file to debug.
2057 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2058 ** New function gdb.lookup_objfile.
2060 New events which are triggered when GDB modifies the state of the
2063 ** gdb.events.inferior_call_pre: Function call is about to be made.
2064 ** gdb.events.inferior_call_post: Function call has just been made.
2065 ** gdb.events.memory_changed: A memory location has been altered.
2066 ** gdb.events.register_changed: A register has been altered.
2068 * New Python-based convenience functions:
2070 ** $_caller_is(name [, number_of_frames])
2071 ** $_caller_matches(regexp [, number_of_frames])
2072 ** $_any_caller_is(name [, number_of_frames])
2073 ** $_any_caller_matches(regexp [, number_of_frames])
2075 * GDB now supports the compilation and injection of source code into
2076 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2077 to compile the source code to object code, and if successful, inject
2078 and execute that code within the current context of the inferior.
2079 Currently the C language is supported. The commands used to
2080 interface with this new feature are:
2082 compile code [-raw|-r] [--] [source code]
2083 compile file [-raw|-r] filename
2087 demangle [-l language] [--] name
2088 Demangle "name" in the specified language, or the current language
2089 if elided. This command is renamed from the "maint demangle" command.
2090 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2091 as "maint demangler-warning".
2093 queue-signal signal-name-or-number
2094 Queue a signal to be delivered to the thread when it is resumed.
2096 add-auto-load-scripts-directory directory
2097 Add entries to the list of directories from which to load auto-loaded
2100 maint print user-registers
2101 List all currently available "user" registers.
2103 compile code [-r|-raw] [--] [source code]
2104 Compile, inject, and execute in the inferior the executable object
2105 code produced by compiling the provided source code.
2107 compile file [-r|-raw] filename
2108 Compile and inject into the inferior the executable object code
2109 produced by compiling the source code stored in the filename
2112 * On resume, GDB now always passes the signal the program had stopped
2113 for to the thread the signal was sent to, even if the user changed
2114 threads before resuming. Previously GDB would often (but not
2115 always) deliver the signal to the thread that happens to be current
2118 * Conversely, the "signal" command now consistently delivers the
2119 requested signal to the current thread. GDB now asks for
2120 confirmation if the program had stopped for a signal and the user
2121 switched threads meanwhile.
2123 * "breakpoint always-inserted" modes "off" and "auto" merged.
2125 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2126 won't remove breakpoints from the target until all threads stop,
2127 even in non-stop mode. The "auto" mode has been removed, and "off"
2128 is now the default mode.
2132 set debug symbol-lookup
2133 show debug symbol-lookup
2134 Control display of debugging info regarding symbol lookup.
2138 ** The -list-thread-groups command outputs an exit-code field for
2139 inferiors that have exited.
2143 MIPS SDE mips*-sde*-elf*
2147 Support for these obsolete configurations has been removed.
2149 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2150 SGI Irix-5.x mips-*-irix5*
2151 SGI Irix-6.x mips-*-irix6*
2152 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2153 VAX running Ultrix vax-*-ultrix*
2155 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2156 and "assf"), have been removed. Use the "sharedlibrary" command, or
2157 its alias "share", instead.
2159 *** Changes in GDB 7.8
2161 * New command line options
2164 This is an alias for the --data-directory option.
2166 * GDB supports printing and modifying of variable length automatic arrays
2167 as specified in ISO C99.
2169 * The ARM simulator now supports instruction level tracing
2170 with or without disassembly.
2174 GDB now has support for scripting using Guile. Whether this is
2175 available is determined at configure time.
2176 Guile version 2.0 or greater is required.
2177 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2179 * New commands (for set/show, see "New options" below)
2183 Invoke CODE by passing it to the Guile interpreter.
2187 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2189 info auto-load guile-scripts [regexp]
2190 Print the list of automatically loaded Guile scripts.
2192 * The source command is now capable of sourcing Guile scripts.
2193 This feature is dependent on the debugger being built with Guile support.
2197 set print symbol-loading (off|brief|full)
2198 show print symbol-loading
2199 Control whether to print informational messages when loading symbol
2200 information for a file. The default is "full", but when debugging
2201 programs with large numbers of shared libraries the amount of output
2202 becomes less useful.
2204 set guile print-stack (none|message|full)
2205 show guile print-stack
2206 Show a stack trace when an error is encountered in a Guile script.
2208 set auto-load guile-scripts (on|off)
2209 show auto-load guile-scripts
2210 Control auto-loading of Guile script files.
2212 maint ada set ignore-descriptive-types (on|off)
2213 maint ada show ignore-descriptive-types
2214 Control whether the debugger should ignore descriptive types in Ada
2215 programs. The default is not to ignore the descriptive types. See
2216 the user manual for more details on descriptive types and the intended
2217 usage of this option.
2219 set auto-connect-native-target
2221 Control whether GDB is allowed to automatically connect to the
2222 native target for the run, attach, etc. commands when not connected
2223 to any target yet. See also "target native" below.
2225 set record btrace replay-memory-access (read-only|read-write)
2226 show record btrace replay-memory-access
2227 Control what memory accesses are allowed during replay.
2229 maint set target-async (on|off)
2230 maint show target-async
2231 This controls whether GDB targets operate in synchronous or
2232 asynchronous mode. Normally the default is asynchronous, if it is
2233 available; but this can be changed to more easily debug problems
2234 occurring only in synchronous mode.
2236 set mi-async (on|off)
2238 Control whether MI asynchronous mode is preferred. This supersedes
2239 "set target-async" of previous GDB versions.
2241 * "set target-async" is deprecated as a CLI option and is now an alias
2242 for "set mi-async" (only puts MI into async mode).
2244 * Background execution commands (e.g., "c&", "s&", etc.) are now
2245 possible ``out of the box'' if the target supports them. Previously
2246 the user would need to explicitly enable the possibility with the
2247 "set target-async on" command.
2249 * New features in the GDB remote stub, GDBserver
2251 ** New option --debug-format=option1[,option2,...] allows one to add
2252 additional text to each output. At present only timestamps
2253 are supported: --debug-format=timestamps.
2254 Timestamps can also be turned on with the
2255 "monitor set debug-format timestamps" command from GDB.
2257 * The 'record instruction-history' command now starts counting instructions
2258 at one. This also affects the instruction ranges reported by the
2259 'record function-call-history' command when given the /i modifier.
2261 * The command 'record function-call-history' supports a new modifier '/c' to
2262 indent the function names based on their call stack depth.
2263 The fields for the '/i' and '/l' modifier have been reordered.
2264 The source line range is now prefixed with 'at'.
2265 The instruction range is now prefixed with 'inst'.
2266 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2267 "record instruction-history" and "list" commands.
2269 * The ranges given as arguments to the 'record function-call-history' and
2270 'record instruction-history' commands are now inclusive.
2272 * The btrace record target now supports the 'record goto' command.
2273 For locations inside the execution trace, the back trace is computed
2274 based on the information stored in the execution trace.
2276 * The btrace record target supports limited reverse execution and replay.
2277 The target does not record data and therefore does not allow reading
2278 memory or registers.
2280 * The "catch syscall" command now works on s390*-linux* targets.
2282 * The "compare-sections" command is no longer specific to target
2283 remote. It now works with all targets.
2285 * All native targets are now consistently called "native".
2286 Consequently, the "target child", "target GNU", "target djgpp",
2287 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2288 commands have been replaced with "target native". The QNX/NTO port
2289 leaves the "procfs" target in place and adds a "native" target for
2290 consistency with other ports. The impact on users should be minimal
2291 as these commands previously either throwed an error, or were
2292 no-ops. The target's name is visible in the output of the following
2293 commands: "help target", "info target", "info files", "maint print
2296 * The "target native" command now connects to the native target. This
2297 can be used to launch native programs even when "set
2298 auto-connect-native-target" is set to off.
2300 * GDB now supports access to Intel MPX registers on GNU/Linux.
2302 * Support for Intel AVX-512 registers on GNU/Linux.
2303 Support displaying and modifying Intel AVX-512 registers
2304 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2306 * New remote packets
2308 qXfer:btrace:read's annex
2309 The qXfer:btrace:read packet supports a new annex 'delta' to read
2310 branch trace incrementally.
2314 ** Valid Python operations on gdb.Value objects representing
2315 structs/classes invoke the corresponding overloaded operators if
2317 ** New `Xmethods' feature in the Python API. Xmethods are
2318 additional methods or replacements for existing methods of a C++
2319 class. This feature is useful for those cases where a method
2320 defined in C++ source code could be inlined or optimized out by
2321 the compiler, making it unavailable to GDB.
2324 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2326 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2327 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2328 its alias "share", instead.
2330 * The commands "set remotebaud" and "show remotebaud" are no longer
2331 supported. Use "set serial baud" and "show serial baud" (respectively)
2336 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2337 target-async". The latter is left as a deprecated alias of the
2338 former for backward compatibility. If the target supports it,
2339 CLI background execution commands are now always possible by
2340 default, independently of whether the frontend stated a
2341 preference for asynchronous execution with "-gdb-set mi-async".
2342 Previously "-gdb-set target-async off" affected both MI execution
2343 commands and CLI execution commands.
2345 *** Changes in GDB 7.7
2347 * Improved support for process record-replay and reverse debugging on
2348 arm*-linux* targets. Support for thumb32 and syscall instruction
2349 recording has been added.
2351 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2353 * GDB now supports Fission DWP file format version 2.
2354 http://gcc.gnu.org/wiki/DebugFission
2356 * New convenience function "$_isvoid", to check whether an expression
2357 is void. A void expression is an expression where the type of the
2358 result is "void". For example, some convenience variables may be
2359 "void" when evaluated (e.g., "$_exitcode" before the execution of
2360 the program being debugged; or an undefined convenience variable).
2361 Another example, when calling a function whose return type is
2364 * The "maintenance print objfiles" command now takes an optional regexp.
2366 * The "catch syscall" command now works on arm*-linux* targets.
2368 * GDB now consistently shows "<not saved>" when printing values of
2369 registers the debug info indicates have not been saved in the frame
2370 and there's nowhere to retrieve them from
2371 (callee-saved/call-clobbered registers):
2376 (gdb) info registers rax
2379 Before, the former would print "<optimized out>", and the latter
2380 "*value not available*".
2382 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2387 ** Frame filters and frame decorators have been added.
2388 ** Temporary breakpoints are now supported.
2389 ** Line tables representation has been added.
2390 ** New attribute 'parent_type' for gdb.Field objects.
2391 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2392 ** New attribute 'name' for gdb.Type objects.
2396 Nios II ELF nios2*-*-elf
2397 Nios II GNU/Linux nios2*-*-linux
2398 Texas Instruments MSP430 msp430*-*-elf
2400 * Removed native configurations
2402 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2403 been removed. ELF variants of these configurations are kept supported.
2405 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2406 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2407 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2408 i[34567]86-*-openbsd3.[0-3]
2409 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2410 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2411 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2415 Like "catch throw", but catches a re-thrown exception.
2416 maint check-psymtabs
2417 Renamed from old "maint check-symtabs".
2419 Perform consistency checks on symtabs.
2420 maint expand-symtabs
2421 Expand symtabs matching an optional regexp.
2424 Display the details of GDB configure-time options.
2426 maint set|show per-command
2427 maint set|show per-command space
2428 maint set|show per-command time
2429 maint set|show per-command symtab
2430 Enable display of per-command gdb resource usage.
2432 remove-symbol-file FILENAME
2433 remove-symbol-file -a ADDRESS
2434 Remove a symbol file added via add-symbol-file. The file to remove
2435 can be identified by its filename or by an address that lies within
2436 the boundaries of this symbol file in memory.
2439 info exceptions REGEXP
2440 Display the list of Ada exceptions defined in the program being
2441 debugged. If provided, only the exceptions whose names match REGEXP
2446 set debug symfile off|on
2448 Control display of debugging info regarding reading symbol files and
2449 symbol tables within those files
2451 set print raw frame-arguments
2452 show print raw frame-arguments
2453 Set/show whether to print frame arguments in raw mode,
2454 disregarding any defined pretty-printers.
2456 set remote trace-status-packet
2457 show remote trace-status-packet
2458 Set/show the use of remote protocol qTStatus packet.
2462 Control display of debugging messages related to Nios II targets.
2466 Control whether target-assisted range stepping is enabled.
2468 set startup-with-shell
2469 show startup-with-shell
2470 Specifies whether Unix child processes are started via a shell or
2475 Use the target memory cache for accesses to the code segment. This
2476 improves performance of remote debugging (particularly disassembly).
2478 * You can now use a literal value 'unlimited' for options that
2479 interpret 0 or -1 as meaning "unlimited". E.g., "set
2480 trace-buffer-size unlimited" is now an alias for "set
2481 trace-buffer-size -1" and "set height unlimited" is now an alias for
2484 * The "set debug symtab-create" debugging option of GDB has been changed to
2485 accept a verbosity level. 0 means "off", 1 provides basic debugging
2486 output, and values of 2 or greater provides more verbose output.
2488 * New command-line options
2490 Display the details of GDB configure-time options.
2492 * The command 'tsave' can now support new option '-ctf' to save trace
2493 buffer in Common Trace Format.
2495 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2498 * GDB now implements the C++ 'typeid' operator.
2500 * The new convenience variable $_exception holds the exception being
2501 thrown or caught at an exception-related catchpoint.
2503 * The exception-related catchpoints, like "catch throw", now accept a
2504 regular expression which can be used to filter exceptions by type.
2506 * The new convenience variable $_exitsignal is automatically set to
2507 the terminating signal number when the program being debugged dies
2508 due to an uncaught signal.
2512 ** All MI commands now accept an optional "--language" option.
2513 Support for this feature can be verified by using the "-list-features"
2514 command, which should contain "language-option".
2516 ** The new command -info-gdb-mi-command allows the user to determine
2517 whether a GDB/MI command is supported or not.
2519 ** The "^error" result record returned when trying to execute an undefined
2520 GDB/MI command now provides a variable named "code" whose content is the
2521 "undefined-command" error code. Support for this feature can be verified
2522 by using the "-list-features" command, which should contain
2523 "undefined-command-error-code".
2525 ** The -trace-save MI command can optionally save trace buffer in Common
2528 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2530 ** The command -data-list-register-values now accepts an optional
2531 "--skip-unavailable" option. When used, only the available registers
2534 ** The new command -trace-frame-collected dumps collected variables,
2535 computed expressions, tvars, memory and registers in a traceframe.
2537 ** The commands -stack-list-locals, -stack-list-arguments and
2538 -stack-list-variables now accept an option "--skip-unavailable".
2539 When used, only the available locals or arguments are displayed.
2541 ** The -exec-run command now accepts an optional "--start" option.
2542 When used, the command follows the same semantics as the "start"
2543 command, stopping the program's execution at the start of its
2544 main subprogram. Support for this feature can be verified using
2545 the "-list-features" command, which should contain
2546 "exec-run-start-option".
2548 ** The new commands -catch-assert and -catch-exceptions insert
2549 catchpoints stopping the program when Ada exceptions are raised.
2551 ** The new command -info-ada-exceptions provides the equivalent of
2552 the new "info exceptions" command.
2554 * New system-wide configuration scripts
2555 A GDB installation now provides scripts suitable for use as system-wide
2556 configuration scripts for the following systems:
2560 * GDB now supports target-assigned range stepping with remote targets.
2561 This improves the performance of stepping source lines by reducing
2562 the number of control packets from/to GDB. See "New remote packets"
2565 * GDB now understands the element 'tvar' in the XML traceframe info.
2566 It has the id of the collected trace state variables.
2568 * On S/390 targets that provide the transactional-execution feature,
2569 the program interruption transaction diagnostic block (TDB) is now
2570 represented as a number of additional "registers" in GDB.
2572 * New remote packets
2576 The vCont packet supports a new 'r' action, that tells the remote
2577 stub to step through an address range itself, without GDB
2578 involvemement at each single-step.
2580 qXfer:libraries-svr4:read's annex
2581 The previously unused annex of the qXfer:libraries-svr4:read packet
2582 is now used to support passing an argument list. The remote stub
2583 reports support for this argument list to GDB's qSupported query.
2584 The defined arguments are "start" and "prev", used to reduce work
2585 necessary for library list updating, resulting in significant
2588 * New features in the GDB remote stub, GDBserver
2590 ** GDBserver now supports target-assisted range stepping. Currently
2591 enabled on x86/x86_64 GNU/Linux targets.
2593 ** GDBserver now adds element 'tvar' in the XML in the reply to
2594 'qXfer:traceframe-info:read'. It has the id of the collected
2595 trace state variables.
2597 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2600 * New 'z' formatter for printing and examining memory, this displays the
2601 value as hexadecimal zero padded on the left to the size of the type.
2603 * GDB can now use Windows x64 unwinding data.
2605 * The "set remotebaud" command has been replaced by "set serial baud".
2606 Similarly, "show remotebaud" has been replaced by "show serial baud".
2607 The "set remotebaud" and "show remotebaud" commands are still available
2608 to provide backward compatibility with older versions of GDB.
2610 *** Changes in GDB 7.6
2612 * Target record has been renamed to record-full.
2613 Record/replay is now enabled with the "record full" command.
2614 This also affects settings that are associated with full record/replay
2615 that have been moved from "set/show record" to "set/show record full":
2617 set|show record full insn-number-max
2618 set|show record full stop-at-limit
2619 set|show record full memory-query
2621 * A new record target "record-btrace" has been added. The new target
2622 uses hardware support to record the control-flow of a process. It
2623 does not support replaying the execution, but it implements the
2624 below new commands for investigating the recorded execution log.
2625 This new recording method can be enabled using:
2629 The "record-btrace" target is only available on Intel Atom processors
2630 and requires a Linux kernel 2.6.32 or later.
2632 * Two new commands have been added for record/replay to give information
2633 about the recorded execution without having to replay the execution.
2634 The commands are only supported by "record btrace".
2636 record instruction-history prints the execution history at
2637 instruction granularity
2639 record function-call-history prints the execution history at
2640 function granularity
2642 * New native configurations
2644 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2645 FreeBSD/powerpc powerpc*-*-freebsd
2646 x86_64/Cygwin x86_64-*-cygwin*
2647 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2651 ARM AArch64 aarch64*-*-elf
2652 ARM AArch64 GNU/Linux aarch64*-*-linux
2653 Lynx 178 PowerPC powerpc-*-lynx*178
2654 x86_64/Cygwin x86_64-*-cygwin*
2655 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2657 * If the configured location of system.gdbinit file (as given by the
2658 --with-system-gdbinit option at configure time) is in the
2659 data-directory (as specified by --with-gdb-datadir at configure
2660 time) or in one of its subdirectories, then GDB will look for the
2661 system-wide init file in the directory specified by the
2662 --data-directory command-line option.
2664 * New command line options:
2666 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2667 other initialization files, unlike -nx which disables all of them.
2669 * Removed command line options
2671 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2674 * The 'ptype' and 'whatis' commands now accept an argument to control
2677 * 'info proc' now works on some core files.
2681 ** Vectors can be created with gdb.Type.vector.
2683 ** Python's atexit.register now works in GDB.
2685 ** Types can be pretty-printed via a Python API.
2687 ** Python 3 is now supported (in addition to Python 2.4 or later)
2689 ** New class gdb.Architecture exposes GDB's internal representation
2690 of architecture in the Python API.
2692 ** New method Frame.architecture returns the gdb.Architecture object
2693 corresponding to the frame's architecture.
2695 * New Python-based convenience functions:
2697 ** $_memeq(buf1, buf2, length)
2698 ** $_streq(str1, str2)
2700 ** $_regex(str, regex)
2702 * The 'cd' command now defaults to using '~' (the home directory) if not
2705 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2706 default for GCC since November 2000.
2708 * The command 'forward-search' can now be abbreviated as 'fo'.
2710 * The command 'info tracepoints' can now display 'installed on target'
2711 or 'not installed on target' for each non-pending location of tracepoint.
2713 * New configure options
2715 --enable-libmcheck/--disable-libmcheck
2716 By default, development versions are built with -lmcheck on hosts
2717 that support it, in order to help track memory corruption issues.
2718 Release versions, on the other hand, are built without -lmcheck
2719 by default. The --enable-libmcheck/--disable-libmcheck configure
2720 options allow the user to override that default.
2721 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2722 This configure option allows the user to build GDB with
2723 libbabeltrace using which GDB can read Common Trace Format data.
2725 * New commands (for set/show, see "New options" below)
2728 Catch signals. This is similar to "handle", but allows commands and
2729 conditions to be attached.
2732 List the BFDs known to GDB.
2734 python-interactive [command]
2736 Start a Python interactive prompt, or evaluate the optional command
2737 and print the result of expressions.
2740 "py" is a new alias for "python".
2742 enable type-printer [name]...
2743 disable type-printer [name]...
2744 Enable or disable type printers.
2748 ** For the Renesas Super-H architecture, the "regs" command has been removed
2749 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2754 set print type methods (on|off)
2755 show print type methods
2756 Control whether method declarations are displayed by "ptype".
2757 The default is to show them.
2759 set print type typedefs (on|off)
2760 show print type typedefs
2761 Control whether typedef definitions are displayed by "ptype".
2762 The default is to show them.
2764 set filename-display basename|relative|absolute
2765 show filename-display
2766 Control the way in which filenames is displayed.
2767 The default is "relative", which preserves previous behavior.
2769 set trace-buffer-size
2770 show trace-buffer-size
2771 Request target to change the size of trace buffer.
2773 set remote trace-buffer-size-packet auto|on|off
2774 show remote trace-buffer-size-packet
2775 Control the use of the remote protocol `QTBuffer:size' packet.
2779 Control display of debugging messages related to ARM AArch64.
2782 set debug coff-pe-read
2783 show debug coff-pe-read
2784 Control display of debugging messages related to reading of COFF/PE
2789 Control display of debugging messages related to Mach-O symbols
2792 set debug notification
2793 show debug notification
2794 Control display of debugging info for async remote notification.
2798 ** Command parameter changes are now notified using new async record
2799 "=cmd-param-changed".
2800 ** Trace frame changes caused by command "tfind" are now notified using
2801 new async record "=traceframe-changed".
2802 ** The creation, deletion and modification of trace state variables
2803 are now notified using new async records "=tsv-created",
2804 "=tsv-deleted" and "=tsv-modified".
2805 ** The start and stop of process record are now notified using new
2806 async record "=record-started" and "=record-stopped".
2807 ** Memory changes are now notified using new async record
2809 ** The data-disassemble command response will include a "fullname" field
2810 containing the absolute file name when source has been requested.
2811 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2812 command, to allow pattern filling of memory areas.
2813 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2814 library load/unload events.
2815 ** The response to breakpoint commands and breakpoint async records
2816 includes an "installed" field containing a boolean state about each
2817 non-pending tracepoint location is whether installed on target or not.
2818 ** Output of the "-trace-status" command includes a "trace-file" field
2819 containing the name of the trace file being examined. This field is
2820 optional, and only present when examining a trace file.
2821 ** The "fullname" field is now always present along with the "file" field,
2822 even if the file cannot be found by GDB.
2824 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2825 You must have the LZMA library available when configuring GDB for this
2826 feature to be enabled. For more information, see:
2827 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2829 * New remote packets
2832 Set the size of trace buffer. The remote stub reports support for this
2833 packet to gdb's qSupported query.
2836 Enable Branch Trace Store (BTS)-based branch tracing for the current
2837 thread. The remote stub reports support for this packet to gdb's
2841 Disable branch tracing for the current thread. The remote stub reports
2842 support for this packet to gdb's qSupported query.
2845 Read the traced branches for the current thread. The remote stub
2846 reports support for this packet to gdb's qSupported query.
2848 *** Changes in GDB 7.5
2850 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2851 for more x32 ABI info.
2853 * GDB now supports access to MIPS DSP registers on Linux targets.
2855 * GDB now supports debugging microMIPS binaries.
2857 * The "info os" command on GNU/Linux can now display information on
2858 several new classes of objects managed by the operating system:
2859 "info os procgroups" lists process groups
2860 "info os files" lists file descriptors
2861 "info os sockets" lists internet-domain sockets
2862 "info os shm" lists shared-memory regions
2863 "info os semaphores" lists semaphores
2864 "info os msg" lists message queues
2865 "info os modules" lists loaded kernel modules
2867 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2868 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2869 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2870 options and inspect the probe arguments using the new $_probe_arg family
2871 of convenience variables. You can obtain more information about SystemTap
2872 in <http://sourceware.org/systemtap/>.
2874 * GDB now supports reversible debugging on ARM, it allows you to
2875 debug basic ARM and THUMB instructions, and provides
2876 record/replay support.
2878 * The option "symbol-reloading" has been deleted as it is no longer used.
2882 ** GDB commands implemented in Python can now be put in command class
2885 ** The "maint set python print-stack on|off" is now deleted.
2887 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2888 apply "flag enum"-style pretty-printing to any enum.
2890 ** gdb.lookup_symbol can now work when there is no current frame.
2892 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2893 the source at which the symbol was defined.
2895 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2896 method 'value'. The former indicates whether the symbol needs a
2897 frame in order to compute its value, and the latter computes the
2900 ** A new method 'referenced_value' on gdb.Value objects which can
2901 dereference pointer as well as C++ reference values.
2903 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2904 which return the global and static blocks (as gdb.Block objects),
2905 of the underlying symbol table, respectively.
2907 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2908 object associated with a PC value.
2910 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2911 of the address range occupied by code for the current source line.
2913 * Go language support.
2914 GDB now supports debugging programs written in the Go programming
2917 * GDBserver now supports stdio connections.
2918 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2920 * The binary "gdbtui" can no longer be built or installed.
2921 Use "gdb -tui" instead.
2923 * GDB will now print "flag" enums specially. A flag enum is one where
2924 all the enumerator values have no bits in common when pairwise
2925 "and"ed. When printing a value whose type is a flag enum, GDB will
2926 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2927 (gdb) print (enum E) 3
2930 * The filename part of a linespec will now match trailing components
2931 of a source file name. For example, "break gcc/expr.c:1000" will
2932 now set a breakpoint in build/gcc/expr.c, but not
2933 build/libcpp/expr.c.
2935 * The "info proc" and "generate-core-file" commands will now also
2936 work on remote targets connected to GDBserver on Linux.
2938 * The command "info catch" has been removed. It has been disabled
2939 since December 2007.
2941 * The "catch exception" and "catch assert" commands now accept
2942 a condition at the end of the command, much like the "break"
2943 command does. For instance:
2945 (gdb) catch exception Constraint_Error if Barrier = True
2947 Previously, it was possible to add a condition to such catchpoints,
2948 but it had to be done as a second step, after the catchpoint had been
2949 created, using the "condition" command.
2951 * The "info static-tracepoint-marker" command will now also work on
2952 native Linux targets with in-process agent.
2954 * GDB can now set breakpoints on inlined functions.
2956 * The .gdb_index section has been updated to include symbols for
2957 inlined functions. GDB will ignore older .gdb_index sections by
2958 default, which could cause symbol files to be loaded more slowly
2959 until their .gdb_index sections can be recreated. The new command
2960 "set use-deprecated-index-sections on" will cause GDB to use any older
2961 .gdb_index sections it finds. This will restore performance, but the
2962 ability to set breakpoints on inlined functions will be lost in symbol
2963 files with older .gdb_index sections.
2965 The .gdb_index section has also been updated to record more information
2966 about each symbol. This speeds up the "info variables", "info functions"
2967 and "info types" commands when used with programs having the .gdb_index
2968 section, as well as speeding up debugging with shared libraries using
2969 the .gdb_index section.
2971 * Ada support for GDB/MI Variable Objects has been added.
2973 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2978 ** New command -info-os is the MI equivalent of "info os".
2980 ** Output logs ("set logging" and related) now include MI output.
2984 ** "set use-deprecated-index-sections on|off"
2985 "show use-deprecated-index-sections on|off"
2986 Controls the use of deprecated .gdb_index sections.
2988 ** "catch load" and "catch unload" can be used to stop when a shared
2989 library is loaded or unloaded, respectively.
2991 ** "enable count" can be used to auto-disable a breakpoint after
2994 ** "info vtbl" can be used to show the virtual method tables for
2995 C++ and Java objects.
2997 ** "explore" and its sub commands "explore value" and "explore type"
2998 can be used to recursively explore values and types of
2999 expressions. These commands are available only if GDB is
3000 configured with '--with-python'.
3002 ** "info auto-load" shows status of all kinds of auto-loaded files,
3003 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3004 sequences of commands files, "info auto-load python-scripts"
3005 shows status of auto-loading Python script files,
3006 "info auto-load local-gdbinit" shows status of loading init file
3007 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3008 status of inferior specific thread debugging shared library loading.
3010 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3011 and "show auto-load-scripts" commands have been deprecated, use their
3012 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3013 and "show auto-load python-scripts" counterparts instead.
3015 ** "dprintf location,format,args..." creates a dynamic printf, which
3016 is basically a breakpoint that does a printf and immediately
3017 resumes your program's execution, so it is like a printf that you
3018 can insert dynamically at runtime instead of at compiletime.
3020 ** "set print symbol"
3022 Controls whether GDB attempts to display the symbol, if any,
3023 corresponding to addresses it prints. This defaults to "on", but
3024 you can set it to "off" to restore GDB's previous behavior.
3026 * Deprecated commands
3028 ** For the Renesas Super-H architecture, the "regs" command has been
3029 deprecated, and "info all-registers" should be used instead.
3033 Renesas RL78 rl78-*-elf
3034 HP OpenVMS ia64 ia64-hp-openvms*
3036 * GDBserver supports evaluation of breakpoint conditions. When
3037 support is advertised by GDBserver, GDB may be told to send the
3038 breakpoint conditions in bytecode form to GDBserver. GDBserver
3039 will only report the breakpoint trigger to GDB when its condition
3044 set mips compression
3045 show mips compression
3046 Select the compressed ISA encoding used in functions that have no symbol
3047 information available. The encoding can be set to either of:
3050 and is updated automatically from ELF file flags if available.
3052 set breakpoint condition-evaluation
3053 show breakpoint condition-evaluation
3054 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3055 GDBserver ("target"). Default option "auto" chooses the most efficient
3057 This option can improve debugger efficiency depending on the speed of the
3061 Disable auto-loading globally.
3064 Show auto-loading setting of all kinds of auto-loaded files.
3066 set auto-load gdb-scripts on|off
3067 show auto-load gdb-scripts
3068 Control auto-loading of GDB canned sequences of commands files.
3070 set auto-load python-scripts on|off
3071 show auto-load python-scripts
3072 Control auto-loading of Python script files.
3074 set auto-load local-gdbinit on|off
3075 show auto-load local-gdbinit
3076 Control loading of init file (.gdbinit) from current directory.
3078 set auto-load libthread-db on|off
3079 show auto-load libthread-db
3080 Control auto-loading of inferior specific thread debugging shared library.
3082 set auto-load scripts-directory <dir1>[:<dir2>...]
3083 show auto-load scripts-directory
3084 Set a list of directories from which to load auto-loaded scripts.
3085 Automatically loaded Python scripts and GDB scripts are located in one
3086 of the directories listed by this option.
3087 The delimiter (':' above) may differ according to the host platform.
3089 set auto-load safe-path <dir1>[:<dir2>...]
3090 show auto-load safe-path
3091 Set a list of directories from which it is safe to auto-load files.
3092 The delimiter (':' above) may differ according to the host platform.
3094 set debug auto-load on|off
3095 show debug auto-load
3096 Control display of debugging info for auto-loading the files above.
3098 set dprintf-style gdb|call|agent
3100 Control the way in which a dynamic printf is performed; "gdb"
3101 requests a GDB printf command, while "call" causes dprintf to call a
3102 function in the inferior. "agent" requests that the target agent
3103 (such as GDBserver) do the printing.
3105 set dprintf-function <expr>
3106 show dprintf-function
3107 set dprintf-channel <expr>
3108 show dprintf-channel
3109 Set the function and optional first argument to the call when using
3110 the "call" style of dynamic printf.
3112 set disconnected-dprintf on|off
3113 show disconnected-dprintf
3114 Control whether agent-style dynamic printfs continue to be in effect
3115 after GDB disconnects.
3117 * New configure options
3119 --with-auto-load-dir
3120 Configure default value for the 'set auto-load scripts-directory'
3121 setting above. It defaults to '$debugdir:$datadir/auto-load',
3122 $debugdir representing global debugging info directories (available
3123 via 'show debug-file-directory') and $datadir representing GDB's data
3124 directory (available via 'show data-directory').
3126 --with-auto-load-safe-path
3127 Configure default value for the 'set auto-load safe-path' setting
3128 above. It defaults to the --with-auto-load-dir setting.
3130 --without-auto-load-safe-path
3131 Set 'set auto-load safe-path' to '/', effectively disabling this
3134 * New remote packets
3136 z0/z1 conditional breakpoints extension
3138 The z0/z1 breakpoint insertion packets have been extended to carry
3139 a list of conditional expressions over to the remote stub depending on the
3140 condition evaluation mode. The use of this extension can be controlled
3141 via the "set remote conditional-breakpoints-packet" command.
3145 Specify the signals which the remote stub may pass to the debugged
3146 program without GDB involvement.
3148 * New command line options
3150 --init-command=FILE, -ix Like --command, -x but execute it
3151 before loading inferior.
3152 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3153 execute it before loading inferior.
3155 *** Changes in GDB 7.4
3157 * GDB now handles ambiguous linespecs more consistently; the existing
3158 FILE:LINE support has been expanded to other types of linespecs. A
3159 breakpoint will now be set on all matching locations in all
3160 inferiors, and locations will be added or removed according to
3163 * GDB now allows you to skip uninteresting functions and files when
3164 stepping with the "skip function" and "skip file" commands.
3166 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3167 and "show remote hardware-watchpoint-length-limit". These allows to
3168 set or show the maximum length limit (in bytes) of a remote
3169 target hardware watchpoint.
3171 This allows e.g. to use "unlimited" hardware watchpoints with the
3172 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3173 watchpoints are slower than real hardware watchpoints but are
3174 significantly faster than gdb software watchpoints.
3178 ** The register_pretty_printer function in module gdb.printing now takes
3179 an optional `replace' argument. If True, the new printer replaces any
3182 ** The "maint set python print-stack on|off" command has been
3183 deprecated and will be deleted in GDB 7.5.
3184 A new command: "set python print-stack none|full|message" has
3185 replaced it. Additionally, the default for "print-stack" is
3186 now "message", which just prints the error message without
3189 ** A prompt substitution hook (prompt_hook) is now available to the
3192 ** A new Python module, gdb.prompt has been added to the GDB Python
3193 modules library. This module provides functionality for
3194 escape sequences in prompts (used by set/show
3195 extended-prompt). These escape sequences are replaced by their
3196 corresponding value.
3198 ** Python commands and convenience-functions located in
3199 'data-directory'/python/gdb/command and
3200 'data-directory'/python/gdb/function are now automatically loaded
3203 ** Blocks now provide four new attributes. global_block and
3204 static_block will return the global and static blocks
3205 respectively. is_static and is_global are boolean attributes
3206 that indicate if the block is one of those two types.
3208 ** Symbols now provide the "type" attribute, the type of the symbol.
3210 ** The "gdb.breakpoint" function has been deprecated in favor of
3213 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3214 of a function. This class is based on the "finish" command
3215 available in the CLI.
3217 ** Type objects for struct and union types now allow access to
3218 the fields using standard Python dictionary (mapping) methods.
3219 For example, "some_type['myfield']" now works, as does
3220 "some_type.items()".
3222 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3225 ** A new function, "deep_items" has been added to the gdb.types
3226 module in the GDB Python modules library. This function returns
3227 an iterator over the fields of a struct or union type. Unlike
3228 the standard Python "iteritems" method, it will recursively traverse
3229 any anonymous fields.
3233 ** "*stopped" events can report several new "reason"s, such as
3236 ** Breakpoint changes are now notified using new async records, like
3237 "=breakpoint-modified".
3239 ** New command -ada-task-info.
3241 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3242 $sdir specifies the default system locations of shared libraries.
3243 $pdir specifies the directory where the libpthread used by the application
3246 GDB no longer looks in $sdir and $pdir after it has searched the directories
3247 mentioned in libthread-db-search-path. If you want to search those
3248 directories, they must be specified in libthread-db-search-path.
3249 The default value of libthread-db-search-path on GNU/Linux and Solaris
3250 systems is now "$sdir:$pdir".
3252 $pdir is not supported by gdbserver, it is currently ignored.
3253 $sdir is supported by gdbserver.
3255 * New configure option --with-iconv-bin.
3256 When using the internationalization support like the one in the GNU C
3257 library, GDB will invoke the "iconv" program to get a list of supported
3258 character sets. If this program lives in a non-standard location, one can
3259 use this option to specify where to find it.
3261 * When natively debugging programs on PowerPC BookE processors running
3262 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3263 watchpoints, which specify a mask in addition to an address to watch.
3264 The mask specifies that some bits of an address (the bits which are
3265 reset in the mask) should be ignored when matching the address accessed
3266 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3267 section in the user manual for more details.
3269 * The new option --once causes GDBserver to stop listening for connections once
3270 the first connection is made. The listening port used by GDBserver will
3271 become available after that.
3273 * New commands "info macros" and "alias" have been added.
3275 * New function parameters suffix @entry specifies value of function parameter
3276 at the time the function got called. Entry values are available only since
3282 "!" is now an alias of the "shell" command.
3283 Note that no space is needed between "!" and SHELL COMMAND.
3287 watch EXPRESSION mask MASK_VALUE
3288 The watch command now supports the mask argument which allows creation
3289 of masked watchpoints, if the current architecture supports this feature.
3291 info auto-load-scripts [REGEXP]
3292 This command was formerly named "maintenance print section-scripts".
3293 It is now generally useful and is no longer a maintenance-only command.
3295 info macro [-all] [--] MACRO
3296 The info macro command has new options `-all' and `--'. The first for
3297 printing all definitions of a macro. The second for explicitly specifying
3298 the end of arguments and the beginning of the macro name in case the macro
3299 name starts with a hyphen.
3301 collect[/s] EXPRESSIONS
3302 The tracepoint collect command now takes an optional modifier "/s"
3303 that directs it to dereference pointer-to-character types and
3304 collect the bytes of memory up to a zero byte. The behavior is
3305 similar to what you see when you use the regular print command on a
3306 string. An optional integer following the "/s" sets a bound on the
3307 number of bytes that will be collected.
3310 The trace start command now interprets any supplied arguments as a
3311 note to be recorded with the trace run, with an effect similar to
3312 setting the variable trace-notes.
3315 The trace stop command now interprets any arguments as a note to be
3316 mentioned along with the tstatus report that the trace was stopped
3317 with a command. The effect is similar to setting the variable
3320 * Tracepoints can now be enabled and disabled at any time after a trace
3321 experiment has been started using the standard "enable" and "disable"
3322 commands. It is now possible to start a trace experiment with no enabled
3323 tracepoints; GDB will display a warning, but will allow the experiment to
3324 begin, assuming that tracepoints will be enabled as needed while the trace
3327 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3328 locations with 4-byte instructions, when they were previously
3329 limited to locations with instructions of 5 bytes or longer.
3333 set debug dwarf2-read
3334 show debug dwarf2-read
3335 Turns on or off display of debugging messages related to reading
3336 DWARF debug info. The default is off.
3338 set debug symtab-create
3339 show debug symtab-create
3340 Turns on or off display of debugging messages related to symbol table
3341 creation. The default is off.
3344 show extended-prompt
3345 Set the GDB prompt, and allow escape sequences to be inserted to
3346 display miscellaneous information (see 'help set extended-prompt'
3347 for the list of sequences). This prompt (and any information
3348 accessed through the escape sequences) is updated every time the
3349 prompt is displayed.
3351 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3352 show print entry-values
3353 Set printing of frame argument values at function entry. In some cases
3354 GDB can determine the value of function argument which was passed by the
3355 function caller, even if the value was modified inside the called function.
3357 set debug entry-values
3358 show debug entry-values
3359 Control display of debugging info for determining frame argument values at
3360 function entry and virtual tail call frames.
3362 set basenames-may-differ
3363 show basenames-may-differ
3364 Set whether a source file may have multiple base names.
3365 (A "base name" is the name of a file with the directory part removed.
3366 Example: The base name of "/home/user/hello.c" is "hello.c".)
3367 If set, GDB will canonicalize file names (e.g., expand symlinks)
3368 before comparing them. Canonicalization is an expensive operation,
3369 but it allows the same file be known by more than one base name.
3370 If not set (the default), all source files are assumed to have just
3371 one base name, and gdb will do file name comparisons more efficiently.
3377 Set a user name and notes for the current and any future trace runs.
3378 This is useful for long-running and/or disconnected traces, to
3379 inform others (or yourself) as to who is running the trace, supply
3380 contact information, or otherwise explain what is going on.
3382 set trace-stop-notes
3383 show trace-stop-notes
3384 Set a note attached to the trace run, that is displayed when the
3385 trace has been stopped by a tstop command. This is useful for
3386 instance as an explanation, if you are stopping a trace run that was
3387 started by someone else.
3389 * New remote packets
3393 Dynamically enable a tracepoint in a started trace experiment.
3397 Dynamically disable a tracepoint in a started trace experiment.
3401 Set the user and notes of the trace run.
3405 Query the current status of a tracepoint.
3409 Query the minimum length of instruction at which a fast tracepoint may
3412 * Dcache size (number of lines) and line-size are now runtime-configurable
3413 via "set dcache line" and "set dcache line-size" commands.
3417 Texas Instruments TMS320C6x tic6x-*-*
3421 Renesas RL78 rl78-*-elf
3423 *** Changes in GDB 7.3.1
3425 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3427 *** Changes in GDB 7.3
3429 * GDB has a new command: "thread find [REGEXP]".
3430 It finds the thread id whose name, target id, or thread extra info
3431 matches the given regular expression.
3433 * The "catch syscall" command now works on mips*-linux* targets.
3435 * The -data-disassemble MI command now supports modes 2 and 3 for
3436 dumping the instruction opcodes.
3438 * New command line options
3440 -data-directory DIR Specify DIR as the "data-directory".
3441 This is mostly for testing purposes.
3443 * The "maint set python auto-load on|off" command has been renamed to
3444 "set auto-load-scripts on|off".
3446 * GDB has a new command: "set directories".
3447 It is like the "dir" command except that it replaces the
3448 source path list instead of augmenting it.
3450 * GDB now understands thread names.
3452 On GNU/Linux, "info threads" will display the thread name as set by
3453 prctl or pthread_setname_np.
3455 There is also a new command, "thread name", which can be used to
3456 assign a name internally for GDB to display.
3459 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3460 has been integrated into GDB.
3464 ** The function gdb.Write now accepts an optional keyword 'stream'.
3465 This keyword, when provided, will direct the output to either
3466 stdout, stderr, or GDB's logging output.
3468 ** Parameters can now be be sub-classed in Python, and in particular
3469 you may implement the get_set_doc and get_show_doc functions.
3470 This improves how Parameter set/show documentation is processed
3471 and allows for more dynamic content.
3473 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3474 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3475 have an is_valid method.
3477 ** Breakpoints can now be sub-classed in Python, and in particular
3478 you may implement a 'stop' function that is executed each time
3479 the inferior reaches that breakpoint.
3481 ** New function gdb.lookup_global_symbol looks up a global symbol.
3483 ** GDB values in Python are now callable if the value represents a
3484 function. For example, if 'some_value' represents a function that
3485 takes two integer parameters and returns a value, you can call
3486 that function like so:
3488 result = some_value (10,20)
3490 ** Module gdb.types has been added.
3491 It contains a collection of utilities for working with gdb.Types objects:
3492 get_basic_type, has_field, make_enum_dict.
3494 ** Module gdb.printing has been added.
3495 It contains utilities for writing and registering pretty-printers.
3496 New classes: PrettyPrinter, SubPrettyPrinter,
3497 RegexpCollectionPrettyPrinter.
3498 New function: register_pretty_printer.
3500 ** New commands "info pretty-printers", "enable pretty-printer" and
3501 "disable pretty-printer" have been added.
3503 ** gdb.parameter("directories") is now available.
3505 ** New function gdb.newest_frame returns the newest frame in the
3508 ** The gdb.InferiorThread class has a new "name" attribute. This
3509 holds the thread's name.
3511 ** Python Support for Inferior events.
3512 Python scripts can add observers to be notified of events
3513 occurring in the process being debugged.
3514 The following events are currently supported:
3515 - gdb.events.cont Continue event.
3516 - gdb.events.exited Inferior exited event.
3517 - gdb.events.stop Signal received, and Breakpoint hit events.
3521 ** GDB now puts template parameters in scope when debugging in an
3522 instantiation. For example, if you have:
3524 template<int X> int func (void) { return X; }
3526 then if you step into func<5>, "print X" will show "5". This
3527 feature requires proper debuginfo support from the compiler; it
3528 was added to GCC 4.5.
3530 ** The motion commands "next", "finish", "until", and "advance" now
3531 work better when exceptions are thrown. In particular, GDB will
3532 no longer lose control of the inferior; instead, the GDB will
3533 stop the inferior at the point at which the exception is caught.
3534 This functionality requires a change in the exception handling
3535 code that was introduced in GCC 4.5.
3537 * GDB now follows GCC's rules on accessing volatile objects when
3538 reading or writing target state during expression evaluation.
3539 One notable difference to prior behavior is that "print x = 0"
3540 no longer generates a read of x; the value of the assignment is
3541 now always taken directly from the value being assigned.
3543 * GDB now has some support for using labels in the program's source in
3544 linespecs. For instance, you can use "advance label" to continue
3545 execution to a label.
3547 * GDB now has support for reading and writing a new .gdb_index
3548 section. This section holds a fast index of DWARF debugging
3549 information and can be used to greatly speed up GDB startup and
3550 operation. See the documentation for `save gdb-index' for details.
3552 * The "watch" command now accepts an optional "-location" argument.
3553 When used, this causes GDB to watch the memory referred to by the
3554 expression. Such a watchpoint is never deleted due to it going out
3557 * GDB now supports thread debugging of core dumps on GNU/Linux.
3559 GDB now activates thread debugging using the libthread_db library
3560 when debugging GNU/Linux core dumps, similarly to when debugging
3561 live processes. As a result, when debugging a core dump file, GDB
3562 is now able to display pthread_t ids of threads. For example, "info
3563 threads" shows the same output as when debugging the process when it
3564 was live. In earlier releases, you'd see something like this:
3567 * 1 LWP 6780 main () at main.c:10
3569 While now you see this:
3572 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3574 It is also now possible to inspect TLS variables when debugging core
3577 When debugging a core dump generated on a machine other than the one
3578 used to run GDB, you may need to point GDB at the correct
3579 libthread_db library with the "set libthread-db-search-path"
3580 command. See the user manual for more details on this command.
3582 * When natively debugging programs on PowerPC BookE processors running
3583 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3584 which stop execution of the inferior whenever it executes an instruction
3585 at any address within the specified range. See the "PowerPC Embedded"
3586 section in the user manual for more details.
3588 * New features in the GDB remote stub, GDBserver
3590 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3591 and i686 LynxOS (version 5.x).
3593 ** GDBserver is now supported on Blackfin Linux.
3595 * New native configurations
3597 ia64 HP-UX ia64-*-hpux*
3601 Analog Devices, Inc. Blackfin Processor bfin-*
3603 * Ada task switching is now supported on sparc-elf targets when
3604 debugging a program using the Ravenscar Profile. For more information,
3605 see the "Tasking Support when using the Ravenscar Profile" section
3606 in the GDB user manual.
3608 * Guile support was removed.
3610 * New features in the GNU simulator
3612 ** The --map-info flag lists all known core mappings.
3614 ** CFI flashes may be simulated via the "cfi" device.
3616 *** Changes in GDB 7.2
3618 * Shared library support for remote targets by default
3620 When GDB is configured for a generic, non-OS specific target, like
3621 for example, --target=arm-eabi or one of the many *-*-elf targets,
3622 GDB now queries remote stubs for loaded shared libraries using the
3623 `qXfer:libraries:read' packet. Previously, shared library support
3624 was always disabled for such configurations.
3628 ** Argument Dependent Lookup (ADL)
3630 In C++ ADL lookup directs function search to the namespaces of its
3631 arguments even if the namespace has not been imported.
3641 Here the compiler will search for `foo' in the namespace of 'b'
3642 and find A::foo. GDB now supports this. This construct is commonly
3643 used in the Standard Template Library for operators.
3645 ** Improved User Defined Operator Support
3647 In addition to member operators, GDB now supports lookup of operators
3648 defined in a namespace and imported with a `using' directive, operators
3649 defined in the global scope, operators imported implicitly from an
3650 anonymous namespace, and the ADL operators mentioned in the previous
3652 GDB now also supports proper overload resolution for all the previously
3653 mentioned flavors of operators.
3655 ** static const class members
3657 Printing of static const class members that are initialized in the
3658 class definition has been fixed.
3660 * Windows Thread Information Block access.
3662 On Windows targets, GDB now supports displaying the Windows Thread
3663 Information Block (TIB) structure. This structure is visible either
3664 by using the new command `info w32 thread-information-block' or, by
3665 dereferencing the new convenience variable named `$_tlb', a
3666 thread-specific pointer to the TIB. This feature is also supported
3667 when remote debugging using GDBserver.
3669 * Static tracepoints
3671 Static tracepoints are calls in the user program into a tracing
3672 library. One such library is a port of the LTTng kernel tracer to
3673 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3674 When debugging with GDBserver, GDB now supports combining the GDB
3675 tracepoint machinery with such libraries. For example: the user can
3676 use GDB to probe a static tracepoint marker (a call from the user
3677 program into the tracing library) with the new "strace" command (see
3678 "New commands" below). This creates a "static tracepoint" in the
3679 breakpoint list, that can be manipulated with the same feature set
3680 as fast and regular tracepoints. E.g., collect registers, local and
3681 global variables, collect trace state variables, and define
3682 tracepoint conditions. In addition, the user can collect extra
3683 static tracepoint marker specific data, by collecting the new
3684 $_sdata internal variable. When analyzing the trace buffer, you can
3685 inspect $_sdata like any other variable available to GDB. For more
3686 information, see the "Tracepoints" chapter in GDB user manual. New
3687 remote packets have been defined to support static tracepoints, see
3688 the "New remote packets" section below.
3690 * Better reconstruction of tracepoints after disconnected tracing
3692 GDB will attempt to download the original source form of tracepoint
3693 definitions when starting a trace run, and then will upload these
3694 upon reconnection to the target, resulting in a more accurate
3695 reconstruction of the tracepoints that are in use on the target.
3699 You can now exercise direct control over the ways that GDB can
3700 affect your program. For instance, you can disallow the setting of
3701 breakpoints, so that the program can run continuously (assuming
3702 non-stop mode). In addition, the "observer" variable is available
3703 to switch all of the different controls; in observer mode, GDB
3704 cannot affect the target's behavior at all, which is useful for
3705 tasks like diagnosing live systems in the field.
3707 * The new convenience variable $_thread holds the number of the
3710 * New remote packets
3714 Return the address of the Windows Thread Information Block of a given thread.
3718 In response to several of the tracepoint packets, the target may now
3719 also respond with a number of intermediate `qRelocInsn' request
3720 packets before the final result packet, to have GDB handle
3721 relocating an instruction to execute at a different address. This
3722 is particularly useful for stubs that support fast tracepoints. GDB
3723 reports support for this feature in the qSupported packet.
3727 List static tracepoint markers in the target program.
3731 List static tracepoint markers at a given address in the target
3734 qXfer:statictrace:read
3736 Read the static trace data collected (by a `collect $_sdata'
3737 tracepoint action). The remote stub reports support for this packet
3738 to gdb's qSupported query.
3742 Send the current settings of GDB's permission flags.
3746 Send part of the source (textual) form of a tracepoint definition,
3747 which includes location, conditional, and action list.
3749 * The source command now accepts a -s option to force searching for the
3750 script in the source search path even if the script name specifies
3753 * New features in the GDB remote stub, GDBserver
3755 - GDBserver now support tracepoints (including fast tracepoints, and
3756 static tracepoints). The feature is currently supported by the
3757 i386-linux and amd64-linux builds. See the "Tracepoints support
3758 in gdbserver" section in the manual for more information.
3760 GDBserver JIT compiles the tracepoint's conditional agent
3761 expression bytecode into native code whenever possible for low
3762 overhead dynamic tracepoints conditionals. For such tracepoints,
3763 an expression that examines program state is evaluated when the
3764 tracepoint is reached, in order to determine whether to capture
3765 trace data. If the condition is simple and false, processing the
3766 tracepoint finishes very quickly and no data is gathered.
3768 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3769 for static tracepoints support.
3771 - GDBserver now supports x86_64 Windows 64-bit debugging.
3773 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3774 it understands register description.
3776 * The --batch flag now disables pagination and queries.
3778 * X86 general purpose registers
3780 GDB now supports reading/writing byte, word and double-word x86
3781 general purpose registers directly. This means you can use, say,
3782 $ah or $ax to refer, respectively, to the byte register AH and
3783 16-bit word register AX that are actually portions of the 32-bit
3784 register EAX or 64-bit register RAX.
3786 * The `commands' command now accepts a range of breakpoints to modify.
3787 A plain `commands' following a command that creates multiple
3788 breakpoints affects all the breakpoints set by that command. This
3789 applies to breakpoints set by `rbreak', and also applies when a
3790 single `break' command creates multiple breakpoints (e.g.,
3791 breakpoints on overloaded c++ functions).
3793 * The `rbreak' command now accepts a filename specification as part of
3794 its argument, limiting the functions selected by the regex to those
3795 in the specified file.
3797 * Support for remote debugging Windows and SymbianOS shared libraries
3798 from Unix hosts has been improved. Non Windows GDB builds now can
3799 understand target reported file names that follow MS-DOS based file
3800 system semantics, such as file names that include drive letters and
3801 use the backslash character as directory separator. This makes it
3802 possible to transparently use the "set sysroot" and "set
3803 solib-search-path" on Unix hosts to point as host copies of the
3804 target's shared libraries. See the new command "set
3805 target-file-system-kind" described below, and the "Commands to
3806 specify files" section in the user manual for more information.
3810 eval template, expressions...
3811 Convert the values of one or more expressions under the control
3812 of the string template to a command line, and call it.
3814 set target-file-system-kind unix|dos-based|auto
3815 show target-file-system-kind
3816 Set or show the assumed file system kind for target reported file
3819 save breakpoints <filename>
3820 Save all current breakpoint definitions to a file suitable for use
3821 in a later debugging session. To read the saved breakpoint
3822 definitions, use the `source' command.
3824 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3827 info static-tracepoint-markers
3828 Display information about static tracepoint markers in the target.
3830 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3831 Define a static tracepoint by probing a marker at the given
3832 function, line, address, or marker ID.
3836 Enable and disable observer mode.
3838 set may-write-registers on|off
3839 set may-write-memory on|off
3840 set may-insert-breakpoints on|off
3841 set may-insert-tracepoints on|off
3842 set may-insert-fast-tracepoints on|off
3843 set may-interrupt on|off
3844 Set individual permissions for GDB effects on the target. Note that
3845 some of these settings can have undesirable or surprising
3846 consequences, particularly when changed in the middle of a session.
3847 For instance, disabling the writing of memory can prevent
3848 breakpoints from being inserted, cause single-stepping to fail, or
3849 even crash your program, if you disable after breakpoints have been
3850 inserted. However, GDB should not crash.
3852 set record memory-query on|off
3853 show record memory-query
3854 Control whether to stop the inferior if memory changes caused
3855 by an instruction cannot be recorded.
3860 The disassemble command now supports "start,+length" form of two arguments.
3864 ** GDB now provides a new directory location, called the python directory,
3865 where Python scripts written for GDB can be installed. The location
3866 of that directory is <data-directory>/python, where <data-directory>
3867 is the GDB data directory. For more details, see section `Scripting
3868 GDB using Python' in the manual.
3870 ** The GDB Python API now has access to breakpoints, symbols, symbol
3871 tables, program spaces, inferiors, threads and frame's code blocks.
3872 Additionally, GDB Parameters can now be created from the API, and
3873 manipulated via set/show in the CLI.
3875 ** New functions gdb.target_charset, gdb.target_wide_charset,
3876 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3878 ** New exception gdb.GdbError.
3880 ** Pretty-printers are now also looked up in the current program space.
3882 ** Pretty-printers can now be individually enabled and disabled.
3884 ** GDB now looks for names of Python scripts to auto-load in a
3885 special section named `.debug_gdb_scripts', in addition to looking
3886 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3888 * Tracepoint actions were unified with breakpoint commands. In particular,
3889 there are no longer differences in "info break" output for breakpoints and
3890 tracepoints and the "commands" command can be used for both tracepoints and
3891 regular breakpoints.
3895 ARM Symbian arm*-*-symbianelf*
3897 * D language support.
3898 GDB now supports debugging programs written in the D programming
3901 * GDB now supports the extended ptrace interface for PowerPC which is
3902 available since Linux kernel version 2.6.34. This automatically enables
3903 any hardware breakpoints and additional hardware watchpoints available in
3904 the processor. The old ptrace interface exposes just one hardware
3905 watchpoint and no hardware breakpoints.
3907 * GDB is now able to use the Data Value Compare (DVC) register available on
3908 embedded PowerPC processors to implement in hardware simple watchpoint
3909 conditions of the form:
3911 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3913 This works in native GDB running on Linux kernels with the extended ptrace
3914 interface mentioned above.
3916 *** Changes in GDB 7.1
3920 ** Namespace Support
3922 GDB now supports importing of namespaces in C++. This enables the
3923 user to inspect variables from imported namespaces. Support for
3924 namepace aliasing has also been added. So, if a namespace is
3925 aliased in the current scope (e.g. namepace C=A; ) the user can
3926 print variables using the alias (e.g. (gdb) print C::x).
3930 All known bugs relating to the printing of virtual base class were
3931 fixed. It is now possible to call overloaded static methods using a
3936 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3937 and reinterpret_cast<> are now handled by the C++ expression parser.
3941 Xilinx MicroBlaze microblaze-*-*
3946 Xilinx MicroBlaze microblaze
3949 * Multi-program debugging.
3951 GDB now has support for multi-program (a.k.a. multi-executable or
3952 multi-exec) debugging. This allows for debugging multiple inferiors
3953 simultaneously each running a different program under the same GDB
3954 session. See "Debugging Multiple Inferiors and Programs" in the
3955 manual for more information. This implied some user visible changes
3956 in the multi-inferior support. For example, "info inferiors" now
3957 lists inferiors that are not running yet or that have exited
3958 already. See also "New commands" and "New options" below.
3960 * New tracing features
3962 GDB's tracepoint facility now includes several new features:
3964 ** Trace state variables
3966 GDB tracepoints now include support for trace state variables, which
3967 are variables managed by the target agent during a tracing
3968 experiment. They are useful for tracepoints that trigger each
3969 other, so for instance one tracepoint can count hits in a variable,
3970 and then a second tracepoint has a condition that is true when the
3971 count reaches a particular value. Trace state variables share the
3972 $-syntax of GDB convenience variables, and can appear in both
3973 tracepoint actions and condition expressions. Use the "tvariable"
3974 command to create, and "info tvariables" to view; see "Trace State
3975 Variables" in the manual for more detail.
3979 GDB now includes an option for defining fast tracepoints, which
3980 targets may implement more efficiently, such as by installing a jump
3981 into the target agent rather than a trap instruction. The resulting
3982 speedup can be by two orders of magnitude or more, although the
3983 tradeoff is that some program locations on some target architectures
3984 might not allow fast tracepoint installation, for instance if the
3985 instruction to be replaced is shorter than the jump. To request a
3986 fast tracepoint, use the "ftrace" command, with syntax identical to
3987 the regular trace command.
3989 ** Disconnected tracing
3991 It is now possible to detach GDB from the target while it is running
3992 a trace experiment, then reconnect later to see how the experiment
3993 is going. In addition, a new variable disconnected-tracing lets you
3994 tell the target agent whether to continue running a trace if the
3995 connection is lost unexpectedly.
3999 GDB now has the ability to save the trace buffer into a file, and
4000 then use that file as a target, similarly to you can do with
4001 corefiles. You can select trace frames, print data that was
4002 collected in them, and use tstatus to display the state of the
4003 tracing run at the moment that it was saved. To create a trace
4004 file, use "tsave <filename>", and to use it, do "target tfile
4007 ** Circular trace buffer
4009 You can ask the target agent to handle the trace buffer as a
4010 circular buffer, discarding the oldest trace frames to make room for
4011 newer ones, by setting circular-trace-buffer to on. This feature may
4012 not be available for all target agents.
4017 The disassemble command, when invoked with two arguments, now requires
4018 the arguments to be comma-separated.
4021 The info variables command now displays variable definitions. Files
4022 which only declare a variable are not shown.
4025 The source command is now capable of sourcing Python scripts.
4026 This feature is dependent on the debugger being build with Python
4029 Related to this enhancement is also the introduction of a new command
4030 "set script-extension" (see below).
4032 * New commands (for set/show, see "New options" below)
4034 record save [<FILENAME>]
4035 Save a file (in core file format) containing the process record
4036 execution log for replay debugging at a later time.
4038 record restore <FILENAME>
4039 Restore the process record execution log that was saved at an
4040 earlier time, for replay debugging.
4042 add-inferior [-copies <N>] [-exec <FILENAME>]
4045 clone-inferior [-copies <N>] [ID]
4046 Make a new inferior ready to execute the same program another
4047 inferior has loaded.
4052 maint info program-spaces
4053 List the program spaces loaded into GDB.
4055 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4056 show remote interrupt-sequence
4057 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4058 as the sequence to the remote target in order to interrupt the execution.
4059 Ctrl-C is a default. Some system prefers BREAK which is high level of
4060 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4061 Magic SysRq g. It is BREAK signal and character 'g'.
4063 set remote interrupt-on-connect [on | off]
4064 show remote interrupt-on-connect
4065 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4066 remote target when gdb connects to it. This is needed when you debug
4069 set remotebreak [on | off]
4071 Deprecated. Use "set/show remote interrupt-sequence" instead.
4073 tvariable $NAME [ = EXP ]
4074 Create or modify a trace state variable.
4077 List trace state variables and their values.
4079 delete tvariable $NAME ...
4080 Delete one or more trace state variables.
4083 Evaluate the given expressions without collecting anything into the
4084 trace buffer. (Valid in tracepoint actions only.)
4086 ftrace FN / FILE:LINE / *ADDR
4087 Define a fast tracepoint at the given function, line, or address.
4089 * New expression syntax
4091 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4092 GDB now parses 0b101010 identically with 42.
4096 set follow-exec-mode new|same
4097 show follow-exec-mode
4098 Control whether GDB reuses the same inferior across an exec call or
4099 creates a new one. This is useful to be able to restart the old
4100 executable after the inferior having done an exec call.
4102 set default-collect EXPR, ...
4103 show default-collect
4104 Define a list of expressions to be collected at each tracepoint.
4105 This is a useful way to ensure essential items are not overlooked,
4106 such as registers or a critical global variable.
4108 set disconnected-tracing
4109 show disconnected-tracing
4110 If set to 1, the target is instructed to continue tracing if it
4111 loses its connection to GDB. If 0, the target is to stop tracing
4114 set circular-trace-buffer
4115 show circular-trace-buffer
4116 If set to on, the target is instructed to use a circular trace buffer
4117 and discard the oldest trace frames instead of stopping the trace due
4118 to a full trace buffer. If set to off, the trace stops when the buffer
4119 fills up. Some targets may not support this.
4121 set script-extension off|soft|strict
4122 show script-extension
4123 If set to "off", the debugger does not perform any script language
4124 recognition, and all sourced files are assumed to be GDB scripts.
4125 If set to "soft" (the default), files are sourced according to
4126 filename extension, falling back to GDB scripts if the first
4128 If set to "strict", files are sourced according to filename extension.
4130 set ada trust-PAD-over-XVS on|off
4131 show ada trust-PAD-over-XVS
4132 If off, activate a workaround against a bug in the debugging information
4133 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4134 the GCC sources for more information about the GNAT encoding and
4135 PAD types in particular). It is always safe to set this option to
4136 off, but this introduces a slight performance penalty. The default
4139 * Python API Improvements
4141 ** GDB provides the new class gdb.LazyString. This is useful in
4142 some pretty-printing cases. The new method gdb.Value.lazy_string
4143 provides a simple way to create objects of this type.
4145 ** The fields returned by gdb.Type.fields now have an
4146 `is_base_class' attribute.
4148 ** The new method gdb.Type.range returns the range of an array type.
4150 ** The new method gdb.parse_and_eval can be used to parse and
4151 evaluate an expression.
4153 * New remote packets
4156 Define a trace state variable.
4159 Get the current value of a trace state variable.
4162 Set desired tracing behavior upon disconnection.
4165 Set the trace buffer to be linear or circular.
4168 Get data about the tracepoints currently in use.
4172 Process record now works correctly with hardware watchpoints.
4174 Multiple bug fixes have been made to the mips-irix port, making it
4175 much more reliable. In particular:
4176 - Debugging threaded applications is now possible again. Previously,
4177 GDB would hang while starting the program, or while waiting for
4178 the program to stop at a breakpoint.
4179 - Attaching to a running process no longer hangs.
4180 - An error occurring while loading a core file has been fixed.
4181 - Changing the value of the PC register now works again. This fixes
4182 problems observed when using the "jump" command, or when calling
4183 a function from GDB, or even when assigning a new value to $pc.
4184 - With the "finish" and "return" commands, the return value for functions
4185 returning a small array is now correctly printed.
4186 - It is now possible to break on shared library code which gets executed
4187 during a shared library init phase (code executed while executing
4188 their .init section). Previously, the breakpoint would have no effect.
4189 - GDB is now able to backtrace through the signal handler for
4190 non-threaded programs.
4192 PIE (Position Independent Executable) programs debugging is now supported.
4193 This includes debugging execution of PIC (Position Independent Code) shared
4194 libraries although for that, it should be possible to run such libraries as an
4197 *** Changes in GDB 7.0
4199 * GDB now has an interface for JIT compilation. Applications that
4200 dynamically generate code can create symbol files in memory and register
4201 them with GDB. For users, the feature should work transparently, and
4202 for JIT developers, the interface is documented in the GDB manual in the
4203 "JIT Compilation Interface" chapter.
4205 * Tracepoints may now be conditional. The syntax is as for
4206 breakpoints; either an "if" clause appended to the "trace" command,
4207 or the "condition" command is available. GDB sends the condition to
4208 the target for evaluation using the same bytecode format as is used
4209 for tracepoint actions.
4211 * The disassemble command now supports: an optional /r modifier, print the
4212 raw instructions in hex as well as in symbolic form, and an optional /m
4213 modifier to print mixed source+assembly.
4215 * Process record and replay
4217 In a architecture environment that supports ``process record and
4218 replay'', ``process record and replay'' target can record a log of
4219 the process execution, and replay it with both forward and reverse
4222 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4223 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4224 set execution-direction {forward|reverse}, for targets that support
4227 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4228 feature is available with a native GDB running on kernel version
4231 * GDB now has support for multi-byte and wide character sets on the
4232 target. Strings whose character type is wchar_t, char16_t, or
4233 char32_t are now correctly printed. GDB supports wide- and unicode-
4234 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4235 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4236 `printf'. This feature requires iconv to work properly; if your
4237 system does not have a working iconv, GDB can use GNU libiconv. See
4238 the installation instructions for more information.
4240 * GDB now supports automatic retrieval of shared library files from
4241 remote targets. To use this feature, specify a system root that begins
4242 with the `remote:' prefix, either via the `set sysroot' command or via
4243 the `--with-sysroot' configure-time option.
4245 * "info sharedlibrary" now takes an optional regex of libraries to show,
4246 and it now reports if a shared library has no debugging information.
4248 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4249 now complete on file names.
4251 * When completing in expressions, gdb will attempt to limit
4252 completions to allowable structure or union fields, where appropriate.
4253 For instance, consider:
4255 # struct example { int f1; double f2; };
4256 # struct example variable;
4259 If the user types TAB at the end of this command line, the available
4260 completions will be "f1" and "f2".
4262 * Inlined functions are now supported. They show up in backtraces, and
4263 the "step", "next", and "finish" commands handle them automatically.
4265 * GDB now supports the token-splicing (##) and stringification (#)
4266 operators when expanding macros. It also supports variable-arity
4269 * GDB now supports inspecting extra signal information, exported by
4270 the new $_siginfo convenience variable. The feature is currently
4271 implemented on linux ARM, i386 and amd64.
4273 * GDB can now display the VFP floating point registers and NEON vector
4274 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4275 can provide these registers (requires Linux 2.6.30 or later). Remote
4276 and simulator targets may also provide them.
4278 * New remote packets
4281 Search memory for a sequence of bytes.
4284 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4285 operation over reliable transport links. Use of this packet is
4286 controlled by the `set remote noack-packet' command.
4289 Kill the process with the specified process ID. Use this in preference
4290 to `k' when multiprocess protocol extensions are supported.
4293 Obtains additional operating system information
4297 Read or write additional signal information.
4299 * Removed remote protocol undocumented extension
4301 An undocumented extension to the remote protocol's `S' stop reply
4302 packet that permitted the stub to pass a process id was removed.
4303 Remote servers should use the `T' stop reply packet instead.
4305 * GDB now supports multiple function calling conventions according to the
4306 DWARF-2 DW_AT_calling_convention function attribute.
4308 * The SH target utilizes the aforementioned change to distinguish between gcc
4309 and Renesas calling convention. It also adds the new CLI commands
4310 `set/show sh calling-convention'.
4312 * GDB can now read compressed debug sections, as produced by GNU gold
4313 with the --compress-debug-sections=zlib flag.
4315 * 64-bit core files are now supported on AIX.
4317 * Thread switching is now supported on Tru64.
4319 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4320 which will be allocated using malloc later in program execution.
4322 * The qXfer:libraries:read remote protocol packet now allows passing a
4323 list of section offsets.
4325 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4326 conditions handling signals delivered during attach or thread creation
4327 have also been fixed.
4329 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4330 From the user's standpoint, all unqualified instances of True and False
4331 are treated as the standard definitions, regardless of context.
4333 * GDB now parses C++ symbol and type names more flexibly. For
4336 template<typename T> class C { };
4339 GDB will now correctly handle all of:
4341 ptype C<char const *>
4342 ptype C<char const*>
4343 ptype C<const char *>
4344 ptype C<const char*>
4346 * New features in the GDB remote stub, gdbserver
4348 - The "--wrapper" command-line argument tells gdbserver to use a
4349 wrapper program to launch programs for debugging.
4351 - On PowerPC and S/390 targets, it is now possible to use a single
4352 gdbserver executable to debug both 32-bit and 64-bit programs.
4353 (This requires gdbserver itself to be built as a 64-bit executable.)
4355 - gdbserver uses the new noack protocol mode for TCP connections to
4356 reduce communications latency, if also supported and enabled in GDB.
4358 - Support for the sparc64-linux-gnu target is now included in
4361 - The amd64-linux build of gdbserver now supports debugging both
4362 32-bit and 64-bit programs.
4364 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4365 now support hardware watchpoints, and will use them automatically
4370 GDB now has support for scripting using Python. Whether this is
4371 available is determined at configure time.
4373 New GDB commands can now be written in Python.
4375 * Ada tasking support
4377 Ada tasks can now be inspected in GDB. The following commands have
4381 Print the list of Ada tasks.
4383 Print detailed information about task number N.
4385 Print the task number of the current task.
4387 Switch the context of debugging to task number N.
4389 * Support for user-defined prefixed commands. The "define" command can
4390 add new commands to existing prefixes, e.g. "target".
4392 * Multi-inferior, multi-process debugging.
4394 GDB now has generalized support for multi-inferior debugging. See
4395 "Debugging Multiple Inferiors" in the manual for more information.
4396 Although availability still depends on target support, the command
4397 set is more uniform now. The GNU/Linux specific multi-forks support
4398 has been migrated to this new framework. This implied some user
4399 visible changes; see "New commands" and also "Removed commands"
4402 * Target descriptions can now describe the target OS ABI. See the
4403 "Target Description Format" section in the user manual for more
4406 * Target descriptions can now describe "compatible" architectures
4407 to indicate that the target can execute applications for a different
4408 architecture in addition to those for the main target architecture.
4409 See the "Target Description Format" section in the user manual for
4412 * Multi-architecture debugging.
4414 GDB now includes general supports for debugging applications on
4415 hybrid systems that use more than one single processor architecture
4416 at the same time. Each such hybrid architecture still requires
4417 specific support to be added. The only hybrid architecture supported
4418 in this version of GDB is the Cell Broadband Engine.
4420 * GDB now supports integrated debugging of Cell/B.E. applications that
4421 use both the PPU and SPU architectures. To enable support for hybrid
4422 Cell/B.E. debugging, you need to configure GDB to support both the
4423 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4424 --enable-targets configure option.
4426 * Non-stop mode debugging.
4428 For some targets, GDB now supports an optional mode of operation in
4429 which you can examine stopped threads while other threads continue
4430 to execute freely. This is referred to as non-stop mode, with the
4431 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4432 section in the user manual for more information.
4434 To be able to support remote non-stop debugging, a remote stub needs
4435 to implement the non-stop mode remote protocol extensions, as
4436 described in the "Remote Non-Stop" section of the user manual. The
4437 GDB remote stub, gdbserver, has been adjusted to support these
4438 extensions on linux targets.
4440 * New commands (for set/show, see "New options" below)
4442 catch syscall [NAME(S) | NUMBER(S)]
4443 Catch system calls. Arguments, which should be names of system
4444 calls or their numbers, mean catch only those syscalls. Without
4445 arguments, every syscall will be caught. When the inferior issues
4446 any of the specified syscalls, GDB will stop and announce the system
4447 call, both when it is called and when its call returns. This
4448 feature is currently available with a native GDB running on the
4449 Linux Kernel, under the following architectures: x86, x86_64,
4450 PowerPC and PowerPC64.
4452 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4454 Search memory for a sequence of bytes.
4456 maint set python print-stack
4457 maint show python print-stack
4458 Show a stack trace when an error is encountered in a Python script.
4461 Invoke CODE by passing it to the Python interpreter.
4466 These allow macros to be defined, undefined, and listed
4470 Show operating system information about processes.
4473 List the inferiors currently under GDB's control.
4476 Switch focus to inferior number NUM.
4479 Detach from inferior number NUM.
4482 Kill inferior number NUM.
4486 set spu stop-on-load
4487 show spu stop-on-load
4488 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4490 set spu auto-flush-cache
4491 show spu auto-flush-cache
4492 Control whether to automatically flush the software-managed cache
4493 during Cell/B.E. debugging.
4495 set sh calling-convention
4496 show sh calling-convention
4497 Control the calling convention used when calling SH target functions.
4500 show debug timestamp
4501 Control display of timestamps with GDB debugging output.
4503 set disassemble-next-line
4504 show disassemble-next-line
4505 Control display of disassembled source lines or instructions when
4508 set remote noack-packet
4509 show remote noack-packet
4510 Set/show the use of remote protocol QStartNoAckMode packet. See above
4511 under "New remote packets."
4513 set remote query-attached-packet
4514 show remote query-attached-packet
4515 Control use of remote protocol `qAttached' (query-attached) packet.
4517 set remote read-siginfo-object
4518 show remote read-siginfo-object
4519 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4522 set remote write-siginfo-object
4523 show remote write-siginfo-object
4524 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4527 set remote reverse-continue
4528 show remote reverse-continue
4529 Control use of remote protocol 'bc' (reverse-continue) packet.
4531 set remote reverse-step
4532 show remote reverse-step
4533 Control use of remote protocol 'bs' (reverse-step) packet.
4535 set displaced-stepping
4536 show displaced-stepping
4537 Control displaced stepping mode. Displaced stepping is a way to
4538 single-step over breakpoints without removing them from the debuggee.
4539 Also known as "out-of-line single-stepping".
4542 show debug displaced
4543 Control display of debugging info for displaced stepping.
4545 maint set internal-error
4546 maint show internal-error
4547 Control what GDB does when an internal error is detected.
4549 maint set internal-warning
4550 maint show internal-warning
4551 Control what GDB does when an internal warning is detected.
4556 Use a wrapper program to launch programs for debugging.
4558 set multiple-symbols (all|ask|cancel)
4559 show multiple-symbols
4560 The value of this variable can be changed to adjust the debugger behavior
4561 when an expression or a breakpoint location contains an ambiguous symbol
4562 name (an overloaded function name, for instance).
4564 set breakpoint always-inserted
4565 show breakpoint always-inserted
4566 Keep breakpoints always inserted in the target, as opposed to inserting
4567 them when resuming the target, and removing them when the target stops.
4568 This option can improve debugger performance on slow remote targets.
4570 set arm fallback-mode (arm|thumb|auto)
4571 show arm fallback-mode
4572 set arm force-mode (arm|thumb|auto)
4574 These commands control how ARM GDB determines whether instructions
4575 are ARM or Thumb. The default for both settings is auto, which uses
4576 the current CPSR value for instructions without symbols; previous
4577 versions of GDB behaved as if "set arm fallback-mode arm".
4579 set disable-randomization
4580 show disable-randomization
4581 Standalone programs run with the virtual address space randomization enabled
4582 by default on some platforms. This option keeps the addresses stable across
4583 multiple debugging sessions.
4587 Control whether other threads are stopped or not when some thread hits
4592 Requests that asynchronous execution is enabled in the target, if available.
4593 In this case, it's possible to resume target in the background, and interact
4594 with GDB while the target is running. "show target-async" displays the
4595 current state of asynchronous execution of the target.
4597 set target-wide-charset
4598 show target-wide-charset
4599 The target-wide-charset is the name of the character set that GDB
4600 uses when printing characters whose type is wchar_t.
4602 set tcp auto-retry (on|off)
4604 set tcp connect-timeout
4605 show tcp connect-timeout
4606 These commands allow GDB to retry failed TCP connections to a remote stub
4607 with a specified timeout period; this is useful if the stub is launched
4608 in parallel with GDB but may not be ready to accept connections immediately.
4610 set libthread-db-search-path
4611 show libthread-db-search-path
4612 Control list of directories which GDB will search for appropriate
4615 set schedule-multiple (on|off)
4616 show schedule-multiple
4617 Allow GDB to resume all threads of all processes or only threads of
4618 the current process.
4622 Use more aggressive caching for accesses to the stack. This improves
4623 performance of remote debugging (particularly backtraces) without
4624 affecting correctness.
4626 set interactive-mode (on|off|auto)
4627 show interactive-mode
4628 Control whether GDB runs in interactive mode (on) or not (off).
4629 When in interactive mode, GDB waits for the user to answer all
4630 queries. Otherwise, GDB does not wait and assumes the default
4631 answer. When set to auto (the default), GDB determines which
4632 mode to use based on the stdin settings.
4637 For program forks, this is replaced by the new more generic `info
4638 inferiors' command. To list checkpoints, you can still use the
4639 `info checkpoints' command, which was an alias for the `info forks'
4643 Replaced by the new `inferior' command. To switch between
4644 checkpoints, you can still use the `restart' command, which was an
4645 alias for the `fork' command.
4648 This is removed, since some targets don't have a notion of
4649 processes. To switch between processes, you can still use the
4650 `inferior' command using GDB's own inferior number.
4653 For program forks, this is replaced by the new more generic `kill
4654 inferior' command. To delete a checkpoint, you can still use the
4655 `delete checkpoint' command, which was an alias for the `delete
4659 For program forks, this is replaced by the new more generic `detach
4660 inferior' command. To detach a checkpoint, you can still use the
4661 `detach checkpoint' command, which was an alias for the `detach
4664 * New native configurations
4666 x86/x86_64 Darwin i[34567]86-*-darwin*
4668 x86_64 MinGW x86_64-*-mingw*
4672 Lattice Mico32 lm32-*
4673 x86 DICOS i[34567]86-*-dicos*
4674 x86_64 DICOS x86_64-*-dicos*
4677 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4678 (mingw32ce) debugging.
4684 These commands were actually not implemented on any target.
4686 *** Changes in GDB 6.8
4688 * New native configurations
4690 NetBSD/hppa hppa*-*netbsd*
4691 Xtensa GNU/Linux xtensa*-*-linux*
4695 NetBSD/hppa hppa*-*-netbsd*
4696 Xtensa GNU/Linux xtensa*-*-linux*
4698 * Change in command line behavior -- corefiles vs. process ids.
4700 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4701 attaching to process NUMBER fails, GDB no longer attempts to open a
4702 core file named NUMBER. Attaching to a program using the -c option
4703 is no longer supported. Instead, use the '-p' or '--pid' options.
4705 * GDB can now be built as a native debugger for debugging Windows x86
4706 (mingw32) Portable Executable (PE) programs.
4708 * Pending breakpoints no longer change their number when their address
4711 * GDB now supports breakpoints with multiple locations,
4712 including breakpoints on C++ constructors, inside C++ templates,
4713 and in inlined functions.
4715 * GDB's ability to debug optimized code has been improved. GDB more
4716 accurately identifies function bodies and lexical blocks that occupy
4717 more than one contiguous range of addresses.
4719 * Target descriptions can now describe registers for PowerPC.
4721 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4722 registers on PowerPC targets.
4724 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4725 targets even when the libthread_db library is not available.
4727 * The GDB remote stub, gdbserver, now supports the new file transfer
4728 commands (remote put, remote get, and remote delete).
4730 * The GDB remote stub, gdbserver, now supports run and attach in
4731 extended-remote mode.
4733 * hppa*64*-*-hpux11* target broken
4734 The debugger is unable to start a program and fails with the following
4735 error: "Error trying to get information about dynamic linker".
4736 The gdb-6.7 release is also affected.
4738 * GDB now supports the --enable-targets= configure option to allow
4739 building a single GDB executable that supports multiple remote
4740 target architectures.
4742 * GDB now supports debugging C and C++ programs which use the
4743 Decimal Floating Point extension. In addition, the PowerPC target
4744 now has a set of pseudo-registers to inspect decimal float values
4745 stored in two consecutive float registers.
4747 * The -break-insert MI command can optionally create pending
4750 * Improved support for debugging Ada
4751 Many improvements to the Ada language support have been made. These
4753 - Better support for Ada2005 interface types
4754 - Improved handling of arrays and slices in general
4755 - Better support for Taft-amendment types
4756 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4758 - Improved command completion in Ada
4761 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4766 set print frame-arguments (all|scalars|none)
4767 show print frame-arguments
4768 The value of this variable can be changed to control which argument
4769 values should be printed by the debugger when displaying a frame.
4774 Transfer files to and from a remote target, and delete remote files.
4781 Transfer files to and from a remote target, and delete remote files.
4783 * New remote packets
4790 Open, close, read, write, and delete files on the remote system.
4793 Attach to an existing process on the remote system, in extended-remote
4797 Run a new process on the remote system, in extended-remote mode.
4799 *** Changes in GDB 6.7
4801 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4802 bfd, libiberty and opcodes, as revealed by static analysis donated by
4803 Coverity, Inc. (http://scan.coverity.com).
4805 * When looking up multiply-defined global symbols, GDB will now prefer the
4806 symbol definition in the current shared library if it was built using the
4807 -Bsymbolic linker option.
4809 * When the Text User Interface (TUI) is not configured, GDB will now
4810 recognize the -tui command-line option and print a message that the TUI
4813 * The GDB remote stub, gdbserver, now has lower overhead for high
4814 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4816 * GDB for MIPS targets now autodetects whether a remote target provides
4817 32-bit or 64-bit register values.
4819 * Support for C++ member pointers has been improved.
4821 * GDB now understands XML target descriptions, which specify the
4822 target's overall architecture. GDB can read a description from
4823 a local file or over the remote serial protocol.
4825 * Vectors of single-byte data use a new integer type which is not
4826 automatically displayed as character or string data.
4828 * The /s format now works with the print command. It displays
4829 arrays of single-byte integers and pointers to single-byte integers
4832 * Target descriptions can now describe target-specific registers,
4833 for architectures which have implemented the support (currently
4834 only ARM, M68K, and MIPS).
4836 * GDB and the GDB remote stub, gdbserver, now support the XScale
4839 * The GDB remote stub, gdbserver, has been updated to support
4840 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4841 has been rewritten to use the standard GDB remote protocol.
4843 * GDB can now step into C++ functions which are called through thunks.
4845 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4847 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4848 layout. It also supports a TextSeg= and DataSeg= response when only
4849 segment base addresses (rather than offsets) are available.
4851 * The /i format now outputs any trailing branch delay slot instructions
4852 immediately following the last instruction within the count specified.
4854 * The GDB remote protocol "T" stop reply packet now supports a
4855 "library" response. Combined with the new "qXfer:libraries:read"
4856 packet, this response allows GDB to debug shared libraries on targets
4857 where the operating system manages the list of loaded libraries (e.g.
4858 Windows and SymbianOS).
4860 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4861 (DLLs) on Windows and Windows CE targets.
4863 * GDB now supports a faster verification that a .debug file matches its binary
4864 according to its build-id signature, if the signature is present.
4870 Enable or disable hardware flow control (RTS/CTS) on the serial port
4871 when debugging using remote targets.
4873 set mem inaccessible-by-default
4874 show mem inaccessible-by-default
4875 If the target supplies a memory map, for instance via the remote
4876 protocol's "qXfer:memory-map:read" packet, setting this variable
4877 prevents GDB from accessing memory outside the memory map. This
4878 is useful for targets with memory mapped registers or which react
4879 badly to accesses of unmapped address space.
4881 set breakpoint auto-hw
4882 show breakpoint auto-hw
4883 If the target supplies a memory map, for instance via the remote
4884 protocol's "qXfer:memory-map:read" packet, setting this variable
4885 lets GDB use hardware breakpoints automatically for memory regions
4886 where it can not use software breakpoints. This covers both the
4887 "break" command and internal breakpoints used for other commands
4888 including "next" and "finish".
4891 catch exception unhandled
4892 Stop the program execution when Ada exceptions are raised.
4895 Stop the program execution when an Ada assertion failed.
4899 Set an alternate system root for target files. This is a more
4900 general version of "set solib-absolute-prefix", which is now
4901 an alias to "set sysroot".
4904 Provide extended SPU facility status information. This set of
4905 commands is available only when debugging the Cell/B.E. SPU
4908 * New native configurations
4910 OpenBSD/sh sh*-*openbsd*
4913 unset tdesc filename
4915 Use the specified local file as an XML target description, and do
4916 not query the target for its built-in description.
4920 OpenBSD/sh sh*-*-openbsd*
4921 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4922 Toshiba Media Processor mep-elf
4924 * New remote packets
4927 Ignore the specified signals; pass them directly to the debugged program
4928 without stopping other threads or reporting them to GDB.
4930 qXfer:features:read:
4931 Read an XML target description from the target, which describes its
4936 Read or write contents of an spufs file on the target system. These
4937 packets are available only on the Cell/B.E. SPU architecture.
4939 qXfer:libraries:read:
4940 Report the loaded shared libraries. Combined with new "T" packet
4941 response, this packet allows GDB to debug shared libraries on
4942 targets where the operating system manages the list of loaded
4943 libraries (e.g. Windows and SymbianOS).
4947 Support for these obsolete configurations has been removed.
4955 i[34567]86-*-lynxos*
4956 i[34567]86-*-netware*
4957 i[34567]86-*-sco3.2v5*
4958 i[34567]86-*-sco3.2v4*
4960 i[34567]86-*-sysv4.2*
4963 i[34567]86-*-unixware2*
4964 i[34567]86-*-unixware*
4973 * Other removed features
4980 Various m68k-only ROM monitors.
4987 Various Renesas ROM monitors and debugging interfaces for SH and
4992 Support for a Macraigor serial interface to on-chip debugging.
4993 GDB does not directly support the newer parallel or USB
4998 A debug information format. The predecessor to DWARF 2 and
4999 DWARF 3, which are still supported.
5001 Support for the HP aCC compiler on HP-UX/PA-RISC
5003 SOM-encapsulated symbolic debugging information, automatic
5004 invocation of pxdb, and the aCC custom C++ ABI. This does not
5005 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5006 with aCC can still be debugged on an assembly level.
5008 MIPS ".pdr" sections
5010 A MIPS-specific format used to describe stack frame layout
5011 in debugging information.
5015 GDB could work with an older version of Guile to debug
5016 the interpreter and Scheme programs running in it.
5018 set mips stack-arg-size
5019 set mips saved-gpreg-size
5021 Use "set mips abi" to control parameter passing for MIPS.
5023 *** Changes in GDB 6.6
5028 Cell Broadband Engine SPU spu-elf
5030 * GDB can now be configured as a cross-debugger targeting native Windows
5031 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5032 running on a Windows system over TCP/IP to debug Windows programs.
5034 * The GDB remote stub, gdbserver, has been updated to support Windows and
5035 Cygwin debugging. Both single-threaded and multi-threaded programs are
5038 * The "set trust-readonly-sections" command works again. This command was
5039 broken in GDB 6.3, 6.4, and 6.5.
5041 * The "load" command now supports writing to flash memory, if the remote
5042 stub provides the required support.
5044 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5045 longer requires symbolic debug information (e.g. DWARF-2).
5050 unset substitute-path
5051 show substitute-path
5052 Manage a list of substitution rules that GDB uses to rewrite the name
5053 of the directories where the sources are located. This can be useful
5054 for instance when the sources were moved to a different location
5055 between compilation and debugging.
5059 Print each CLI command as it is executed. Each command is prefixed with
5060 a number of `+' symbols representing the nesting depth.
5061 The source command now has a `-v' option to enable the same feature.
5065 The ARM Demon monitor support (RDP protocol, "target rdp").
5067 Kernel Object Display, an embedded debugging feature which only worked with
5068 an obsolete version of Cisco IOS.
5070 The 'set download-write-size' and 'show download-write-size' commands.
5072 * New remote packets
5075 Tell a stub about GDB client features, and request remote target features.
5076 The first feature implemented is PacketSize, which allows the target to
5077 specify the size of packets it can handle - to minimize the number of
5078 packets required and improve performance when connected to a remote
5082 Fetch an OS auxilliary vector from the remote stub. This packet is a
5083 more efficient replacement for qPart:auxv:read.
5085 qXfer:memory-map:read:
5086 Fetch a memory map from the remote stub, including information about
5087 RAM, ROM, and flash memory devices.
5092 Erase and program a flash memory device.
5094 * Removed remote packets
5097 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5098 used it, and only gdbserver implemented it.
5100 *** Changes in GDB 6.5
5104 Renesas M32C/M16C m32c-elf
5106 Morpho Technologies ms1 ms1-elf
5110 init-if-undefined Initialize a convenience variable, but
5111 only if it doesn't already have a value.
5113 The following commands are presently only implemented for native GNU/Linux:
5115 checkpoint Save a snapshot of the program state.
5117 restart <n> Return the program state to a
5118 previously saved state.
5120 info checkpoints List currently saved checkpoints.
5122 delete-checkpoint <n> Delete a previously saved checkpoint.
5124 set|show detach-on-fork Tell gdb whether to detach from a newly
5125 forked process, or to keep debugging it.
5127 info forks List forks of the user program that
5128 are available to be debugged.
5130 fork <n> Switch to debugging one of several
5131 forks of the user program that are
5132 available to be debugged.
5134 delete-fork <n> Delete a fork from the list of forks
5135 that are available to be debugged (and
5136 kill the forked process).
5138 detach-fork <n> Delete a fork from the list of forks
5139 that are available to be debugged (and
5140 allow the process to continue).
5144 Morpho Technologies ms2 ms1-elf
5146 * Improved Windows host support
5148 GDB now builds as a cross debugger hosted on i686-mingw32, including
5149 native console support, and remote communications using either
5150 network sockets or serial ports.
5152 * Improved Modula-2 language support
5154 GDB can now print most types in the Modula-2 syntax. This includes:
5155 basic types, set types, record types, enumerated types, range types,
5156 pointer types and ARRAY types. Procedure var parameters are correctly
5157 printed and hexadecimal addresses and character constants are also
5158 written in the Modula-2 syntax. Best results can be obtained by using
5159 GNU Modula-2 together with the -gdwarf-2 command line option.
5163 The ARM rdi-share module.
5165 The Netware NLM debug server.
5167 *** Changes in GDB 6.4
5169 * New native configurations
5171 OpenBSD/arm arm*-*-openbsd*
5172 OpenBSD/mips64 mips64-*-openbsd*
5176 Morpho Technologies ms1 ms1-elf
5178 * New command line options
5180 --batch-silent As for --batch, but totally silent.
5181 --return-child-result The debugger will exist with the same value
5182 the child (debugged) program exited with.
5183 --eval-command COMMAND, -ex COMMAND
5184 Execute a single GDB CLI command. This may be
5185 specified multiple times and in conjunction
5186 with the --command (-x) option.
5188 * Deprecated commands removed
5190 The following commands, that were deprecated in 2000, have been
5194 set|show arm disassembly-flavor set|show arm disassembler
5195 othernames set arm disassembler
5196 set|show remotedebug set|show debug remote
5197 set|show archdebug set|show debug arch
5198 set|show eventdebug set|show debug event
5201 * New BSD user-level threads support
5203 It is now possible to debug programs using the user-level threads
5204 library on OpenBSD and FreeBSD. Currently supported (target)
5207 FreeBSD/amd64 x86_64-*-freebsd*
5208 FreeBSD/i386 i386-*-freebsd*
5209 OpenBSD/i386 i386-*-openbsd*
5211 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5212 are not yet supported.
5214 * New support for Matsushita MN10300 w/sim added
5215 (Work in progress). mn10300-elf.
5217 * REMOVED configurations and files
5219 VxWorks and the XDR protocol *-*-vxworks
5220 Motorola MCORE mcore-*-*
5221 National Semiconductor NS32000 ns32k-*-*
5223 * New "set print array-indexes" command
5225 After turning this setting "on", GDB prints the index of each element
5226 when displaying arrays. The default is "off" to preserve the previous
5229 * VAX floating point support
5231 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5233 * User-defined command support
5235 In addition to using $arg0..$arg9 for argument passing, it is now possible
5236 to use $argc to determine now many arguments have been passed. See the
5237 section on user-defined commands in the user manual for more information.
5239 *** Changes in GDB 6.3:
5241 * New command line option
5243 GDB now accepts -l followed by a number to set the timeout for remote
5246 * GDB works with GCC -feliminate-dwarf2-dups
5248 GDB now supports a more compact representation of DWARF-2 debug
5249 information using DW_FORM_ref_addr references. These are produced
5250 by GCC with the option -feliminate-dwarf2-dups and also by some
5251 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5252 to use -feliminate-dwarf2-dups.
5254 * Internationalization
5256 When supported by the host system, GDB will be built with
5257 internationalization (libintl). The task of marking up the sources is
5258 continued, we're looking forward to our first translation.
5262 Initial support for debugging programs compiled with the GNAT
5263 implementation of the Ada programming language has been integrated
5264 into GDB. In this release, support is limited to expression evaluation.
5266 * New native configurations
5268 GNU/Linux/m32r m32r-*-linux-gnu
5272 GDB's remote protocol now includes support for the 'p' packet. This
5273 packet is used to fetch individual registers from a remote inferior.
5275 * END-OF-LIFE registers[] compatibility module
5277 GDB's internal register infrastructure has been completely rewritten.
5278 The new infrastructure making possible the implementation of key new
5279 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5282 GDB 6.3 will be the last release to include the registers[]
5283 compatibility module that allowed out-of-date configurations to
5284 continue to work. This change directly impacts the following
5294 powerpc bdm protocol
5296 Unless there is activity to revive these configurations, they will be
5297 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5299 * OBSOLETE configurations and files
5301 Configurations that have been declared obsolete in this release have
5302 been commented out. Unless there is activity to revive these
5303 configurations, the next release of GDB will have their sources
5304 permanently REMOVED.
5313 *** Changes in GDB 6.2.1:
5315 * MIPS `break main; run' gave an heuristic-fence-post warning
5317 When attempting to run even a simple program, a warning about
5318 heuristic-fence-post being hit would be reported. This problem has
5321 * MIPS IRIX 'long double' crashed GDB
5323 When examining a long double variable, GDB would get a segmentation
5324 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5325 IRIX long double values).
5329 A bug in the VAX stack code was causing problems with the "next"
5330 command. This problem has been fixed.
5332 *** Changes in GDB 6.2:
5334 * Fix for ``many threads''
5336 On GNU/Linux systems that use the NPTL threads library, a program
5337 rapidly creating and deleting threads would confuse GDB leading to the
5340 ptrace: No such process.
5341 thread_db_get_info: cannot get thread info: generic error
5343 This problem has been fixed.
5345 * "-async" and "-noasync" options removed.
5347 Support for the broken "-noasync" option has been removed (it caused
5350 * New ``start'' command.
5352 This command runs the program until the beginning of the main procedure.
5354 * New BSD Kernel Data Access Library (libkvm) interface
5356 Using ``target kvm'' it is now possible to debug kernel core dumps and
5357 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5358 platforms. Currently supported (native-only) configurations are:
5360 FreeBSD/amd64 x86_64-*-freebsd*
5361 FreeBSD/i386 i?86-*-freebsd*
5362 NetBSD/i386 i?86-*-netbsd*
5363 NetBSD/m68k m68*-*-netbsd*
5364 NetBSD/sparc sparc-*-netbsd*
5365 OpenBSD/amd64 x86_64-*-openbsd*
5366 OpenBSD/i386 i?86-*-openbsd*
5367 OpenBSD/m68k m68*-openbsd*
5368 OpenBSD/sparc sparc-*-openbsd*
5370 * Signal trampoline code overhauled
5372 Many generic problems with GDB's signal handling code have been fixed.
5373 These include: backtraces through non-contiguous stacks; recognition
5374 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5375 call; backtrace through a signal trampoline; step into and out of
5376 signal handlers; and single-stepping in the signal trampoline.
5378 Please note that kernel bugs are a limiting factor here. These
5379 features have been shown to work on an s390 GNU/Linux system that
5380 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5382 * Cygwin support for DWARF 2 added.
5384 * New native configurations
5386 GNU/Linux/hppa hppa*-*-linux*
5387 OpenBSD/hppa hppa*-*-openbsd*
5388 OpenBSD/m68k m68*-*-openbsd*
5389 OpenBSD/m88k m88*-*-openbsd*
5390 OpenBSD/powerpc powerpc-*-openbsd*
5391 NetBSD/vax vax-*-netbsd*
5392 OpenBSD/vax vax-*-openbsd*
5394 * END-OF-LIFE frame compatibility module
5396 GDB's internal frame infrastructure has been completely rewritten.
5397 The new infrastructure making it possible to support key new features
5398 including DWARF 2 Call Frame Information. To aid in the task of
5399 migrating old configurations to this new infrastructure, a
5400 compatibility module, that allowed old configurations to continue to
5401 work, was also included.
5403 GDB 6.2 will be the last release to include this frame compatibility
5404 module. This change directly impacts the following configurations:
5414 Unless there is activity to revive these configurations, they will be
5415 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5417 * REMOVED configurations and files
5419 Sun 3, running SunOS 3 m68*-*-sunos3*
5420 Sun 3, running SunOS 4 m68*-*-sunos4*
5421 Sun 2, running SunOS 3 m68000-*-sunos3*
5422 Sun 2, running SunOS 4 m68000-*-sunos4*
5423 Motorola 680x0 running LynxOS m68*-*-lynxos*
5424 AT&T 3b1/Unix pc m68*-att-*
5425 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5426 decstation mips-dec-* mips-little-*
5427 riscos mips-*-riscos* mips-*-sysv*
5428 sonymips mips-sony-*
5429 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5431 *** Changes in GDB 6.1.1:
5433 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5435 The TUI (Text-mode User Interface) is now built as part of a default
5436 GDB configuration. It is enabled by either selecting the TUI with the
5437 command line option "-i=tui" or by running the separate "gdbtui"
5438 program. For more information on the TUI, see the manual "Debugging
5441 * Pending breakpoint support (also included in GDB 6.1)
5443 Support has been added to allow you to specify breakpoints in shared
5444 libraries that have not yet been loaded. If a breakpoint location
5445 cannot be found, and the "breakpoint pending" option is set to auto,
5446 GDB queries you if you wish to make the breakpoint pending on a future
5447 shared-library load. If and when GDB resolves the breakpoint symbol,
5448 the pending breakpoint is removed as one or more regular breakpoints
5451 Pending breakpoints are very useful for GCJ Java debugging.
5453 * Fixed ISO-C build problems
5455 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5456 non ISO-C code that stopped them being built using a more strict ISO-C
5457 compiler (e.g., IBM's C compiler).
5459 * Fixed build problem on IRIX 5
5461 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5462 wasn't able to compile compile on an IRIX 5 system.
5464 * Added execute permission to gdb/gdbserver/configure
5466 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5467 permission. This bug would cause configure to fail on a number of
5468 systems (Solaris, IRIX). Ref: server/519.
5470 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5472 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5473 has been updated to use constant array sizes.
5475 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5477 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5478 its generated DWARF Call Frame Info. This encoding was causing GDB to
5479 panic, that panic has been fixed. Ref: gdb/1628.
5481 * Fixed a problem when examining parameters in shared library code.
5483 When examining parameters in optimized shared library code generated
5484 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5485 not available''. GDB now correctly displays the variable's value.
5487 *** Changes in GDB 6.1:
5489 * Removed --with-mmalloc
5491 Support for the mmalloc memory manager has been removed, as it
5492 conflicted with the internal gdb byte cache.
5494 * Changes in AMD64 configurations
5496 The AMD64 target now includes the %cs and %ss registers. As a result
5497 the AMD64 remote protocol has changed; this affects the floating-point
5498 and SSE registers. If you rely on those registers for your debugging,
5499 you should upgrade gdbserver on the remote side.
5501 * Revised SPARC target
5503 The SPARC target has been completely revised, incorporating the
5504 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5505 support for LynxOS and SunOS 4 has been dropped. Calling functions
5506 from within GDB on operating systems with a non-executable stack
5507 (Solaris, OpenBSD) now works.
5511 GDB has a new C++ demangler which does a better job on the mangled
5512 names generated by current versions of g++. It also runs faster, so
5513 with this and other changes gdb should now start faster on large C++
5516 * DWARF 2 Location Expressions
5518 GDB support for location expressions has been extended to support function
5519 arguments and frame bases. Older versions of GDB could crash when they
5522 * C++ nested types and namespaces
5524 GDB's support for nested types and namespaces in C++ has been
5525 improved, especially if you use the DWARF 2 debugging format. (This
5526 is the default for recent versions of GCC on most platforms.)
5527 Specifically, if you have a class "Inner" defined within a class or
5528 namespace "Outer", then GDB realizes that the class's name is
5529 "Outer::Inner", not simply "Inner". This should greatly reduce the
5530 frequency of complaints about not finding RTTI symbols. In addition,
5531 if you are stopped at inside of a function defined within a namespace,
5532 GDB modifies its name lookup accordingly.
5534 * New native configurations
5536 NetBSD/amd64 x86_64-*-netbsd*
5537 OpenBSD/amd64 x86_64-*-openbsd*
5538 OpenBSD/alpha alpha*-*-openbsd*
5539 OpenBSD/sparc sparc-*-openbsd*
5540 OpenBSD/sparc64 sparc64-*-openbsd*
5542 * New debugging protocols
5544 M32R with SDI protocol m32r-*-elf*
5546 * "set prompt-escape-char" command deleted.
5548 The command "set prompt-escape-char" has been deleted. This command,
5549 and its very obscure effect on GDB's prompt, was never documented,
5550 tested, nor mentioned in the NEWS file.
5552 * OBSOLETE configurations and files
5554 Configurations that have been declared obsolete in this release have
5555 been commented out. Unless there is activity to revive these
5556 configurations, the next release of GDB will have their sources
5557 permanently REMOVED.
5559 Sun 3, running SunOS 3 m68*-*-sunos3*
5560 Sun 3, running SunOS 4 m68*-*-sunos4*
5561 Sun 2, running SunOS 3 m68000-*-sunos3*
5562 Sun 2, running SunOS 4 m68000-*-sunos4*
5563 Motorola 680x0 running LynxOS m68*-*-lynxos*
5564 AT&T 3b1/Unix pc m68*-att-*
5565 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5566 decstation mips-dec-* mips-little-*
5567 riscos mips-*-riscos* mips-*-sysv*
5568 sonymips mips-sony-*
5569 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5571 * REMOVED configurations and files
5573 SGI Irix-4.x mips-sgi-irix4 or iris4
5574 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5575 Z8000 simulator z8k-zilog-none or z8ksim
5576 Matsushita MN10200 w/simulator mn10200-*-*
5577 H8/500 simulator h8500-hitachi-hms or h8500hms
5578 HP/PA running BSD hppa*-*-bsd*
5579 HP/PA running OSF/1 hppa*-*-osf*
5580 HP/PA Pro target hppa*-*-pro*
5581 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5582 386BSD i[3456]86-*-bsd*
5583 Sequent family i[3456]86-sequent-sysv4*
5584 i[3456]86-sequent-sysv*
5585 i[3456]86-sequent-bsd*
5586 SPARC running LynxOS sparc-*-lynxos*
5587 SPARC running SunOS 4 sparc-*-sunos4*
5588 Tsqware Sparclet sparclet-*-*
5589 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5591 *** Changes in GDB 6.0:
5595 Support for debugging the Objective-C programming language has been
5596 integrated into GDB.
5598 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5600 DWARF 2's Call Frame Information makes available compiler generated
5601 information that more exactly describes the program's run-time stack.
5602 By using this information, GDB is able to provide more robust stack
5605 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5606 have been updated to use a new backtrace mechanism which includes
5607 DWARF 2 CFI support.
5611 GDB's remote protocol has been extended to include support for hosted
5612 file I/O (where the remote target uses GDB's file system). See GDB's
5613 remote protocol documentation for details.
5615 * All targets using the new architecture framework.
5617 All of GDB's targets have been updated to use the new internal
5618 architecture framework. The way is now open for future GDB releases
5619 to include cross-architecture native debugging support (i386 on amd64,
5622 * GNU/Linux's Thread Local Storage (TLS)
5624 GDB now includes support for for the GNU/Linux implementation of
5625 per-thread variables.
5627 * GNU/Linux's Native POSIX Thread Library (NPTL)
5629 GDB's thread code has been updated to work with either the new
5630 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5632 * Separate debug info.
5634 GDB, in conjunction with BINUTILS, now supports a mechanism for
5635 automatically loading debug information from a separate file. Instead
5636 of shipping full debug and non-debug versions of system libraries,
5637 system integrators can now instead ship just the stripped libraries
5638 and optional debug files.
5640 * DWARF 2 Location Expressions
5642 DWARF 2 Location Expressions allow the compiler to more completely
5643 describe the location of variables (even in optimized code) to the
5646 GDB now includes preliminary support for location expressions (support
5647 for DW_OP_piece is still missing).
5651 A number of long standing bugs that caused GDB to die while starting a
5652 Java application have been fixed. GDB's Java support is now
5653 considered "useable".
5655 * GNU/Linux support for fork, vfork, and exec.
5657 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5658 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5661 * GDB supports logging output to a file
5663 There are two new commands, "set logging" and "show logging", which can be
5664 used to capture GDB's output to a file.
5666 * The meaning of "detach" has changed for gdbserver
5668 The "detach" command will now resume the application, as documented. To
5669 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5672 * d10v, m68hc11 `regs' command deprecated
5674 The `info registers' command has been updated so that it displays the
5675 registers using a format identical to the old `regs' command.
5679 A new command, "maint set profile on/off", has been added. This command can
5680 be used to enable or disable profiling while running GDB, to profile a
5681 session or a set of commands. In addition there is a new configure switch,
5682 "--enable-profiling", which will cause GDB to be compiled with profiling
5683 data, for more informative profiling results.
5685 * Default MI syntax changed to "mi2".
5687 The default MI (machine interface) syntax, enabled by the command line
5688 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5689 "mi1", can be enabled by specifying the option "-i=mi1".
5691 Support for the original "mi0" syntax (included in GDB 5.0) has been
5694 Fix for gdb/192: removed extraneous space when displaying frame level.
5695 Fix for gdb/672: update changelist is now output in mi list format.
5696 Fix for gdb/702: a -var-assign that updates the value now shows up
5697 in a subsequent -var-update.
5699 * New native configurations.
5701 FreeBSD/amd64 x86_64-*-freebsd*
5703 * Multi-arched targets.
5705 HP/PA HPUX11 hppa*-*-hpux*
5706 Renesas M32R/D w/simulator m32r-*-elf*
5708 * OBSOLETE configurations and files
5710 Configurations that have been declared obsolete in this release have
5711 been commented out. Unless there is activity to revive these
5712 configurations, the next release of GDB will have their sources
5713 permanently REMOVED.
5715 Z8000 simulator z8k-zilog-none or z8ksim
5716 Matsushita MN10200 w/simulator mn10200-*-*
5717 H8/500 simulator h8500-hitachi-hms or h8500hms
5718 HP/PA running BSD hppa*-*-bsd*
5719 HP/PA running OSF/1 hppa*-*-osf*
5720 HP/PA Pro target hppa*-*-pro*
5721 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5722 Sequent family i[3456]86-sequent-sysv4*
5723 i[3456]86-sequent-sysv*
5724 i[3456]86-sequent-bsd*
5725 Tsqware Sparclet sparclet-*-*
5726 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5728 * REMOVED configurations and files
5731 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5732 IBM AIX PS/2 i[3456]86-*-aix
5733 i386 running Mach 3.0 i[3456]86-*-mach3*
5734 i386 running Mach i[3456]86-*-mach*
5735 i386 running OSF/1 i[3456]86-*osf1mk*
5736 HP/Apollo 68k Family m68*-apollo*-sysv*,
5738 m68*-hp-bsd*, m68*-hp-hpux*
5739 Argonaut Risc Chip (ARC) arc-*-*
5740 Mitsubishi D30V d30v-*-*
5741 Fujitsu FR30 fr30-*-elf*
5742 OS/9000 i[34]86-*-os9k
5743 I960 with MON960 i960-*-coff
5745 * MIPS $fp behavior changed
5747 The convenience variable $fp, for the MIPS, now consistently returns
5748 the address of the current frame's base. Previously, depending on the
5749 context, $fp could refer to either $sp or the current frame's base
5750 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5751 The GNU Source-Level Debugger''.
5753 *** Changes in GDB 5.3:
5755 * GNU/Linux shared library multi-threaded performance improved.
5757 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5758 `/proc', in preference to `ptrace' for memory reads. This may result
5759 in an improvement in the start-up time of multi-threaded, shared
5760 library applications when run under GDB. One GDB user writes: ``loads
5761 shared libs like mad''.
5763 * ``gdbserver'' now supports multi-threaded applications on some targets
5765 Support for debugging multi-threaded applications which use
5766 the GNU/Linux LinuxThreads package has been added for
5767 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5768 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5770 * GDB now supports C/C++ preprocessor macros.
5772 GDB now expands preprocessor macro invocations in C/C++ expressions,
5773 and provides various commands for showing macro definitions and how
5776 The new command `macro expand EXPRESSION' expands any macro
5777 invocations in expression, and shows the result.
5779 The new command `show macro MACRO-NAME' shows the definition of the
5780 macro named MACRO-NAME, and where it was defined.
5782 Most compilers don't include information about macros in the debugging
5783 information by default. In GCC 3.1, for example, you need to compile
5784 your program with the options `-gdwarf-2 -g3'. If the macro
5785 information is present in the executable, GDB will read it.
5787 * Multi-arched targets.
5789 DEC Alpha (partial) alpha*-*-*
5790 DEC VAX (partial) vax-*-*
5792 National Semiconductor NS32000 (partial) ns32k-*-*
5793 Motorola 68000 (partial) m68k-*-*
5794 Motorola MCORE mcore-*-*
5798 Fujitsu FRV architecture added by Red Hat frv*-*-*
5801 * New native configurations
5803 Alpha NetBSD alpha*-*-netbsd*
5804 SH NetBSD sh*-*-netbsdelf*
5805 MIPS NetBSD mips*-*-netbsd*
5806 UltraSPARC NetBSD sparc64-*-netbsd*
5808 * OBSOLETE configurations and files
5810 Configurations that have been declared obsolete in this release have
5811 been commented out. Unless there is activity to revive these
5812 configurations, the next release of GDB will have their sources
5813 permanently REMOVED.
5815 Mitsubishi D30V d30v-*-*
5816 OS/9000 i[34]86-*-os9k
5817 IBM AIX PS/2 i[3456]86-*-aix
5818 Fujitsu FR30 fr30-*-elf*
5819 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5820 Argonaut Risc Chip (ARC) arc-*-*
5821 i386 running Mach 3.0 i[3456]86-*-mach3*
5822 i386 running Mach i[3456]86-*-mach*
5823 i386 running OSF/1 i[3456]86-*osf1mk*
5824 HP/Apollo 68k Family m68*-apollo*-sysv*,
5826 m68*-hp-bsd*, m68*-hp-hpux*
5827 I960 with MON960 i960-*-coff
5829 * OBSOLETE languages
5831 CHILL, a Pascal like language used by telecommunications companies.
5833 * REMOVED configurations and files
5835 AMD 29k family via UDI a29k-amd-udi, udi29k
5836 A29K VxWorks a29k-*-vxworks
5837 AMD 29000 embedded, using EBMON a29k-none-none
5838 AMD 29000 embedded with COFF a29k-none-coff
5839 AMD 29000 embedded with a.out a29k-none-aout
5841 testsuite/gdb.hp/gdb.threads-hp/ directory
5843 * New command "set max-user-call-depth <nnn>"
5845 This command allows the user to limit the call depth of user-defined
5846 commands. The default is 1024.
5848 * Changes in FreeBSD/i386 native debugging.
5850 Support for the "generate-core-file" has been added.
5852 * New commands "dump", "append", and "restore".
5854 These commands allow data to be copied from target memory
5855 to a bfd-format or binary file (dump and append), and back
5856 from a file into memory (restore).
5858 * Improved "next/step" support on multi-processor Alpha Tru64.
5860 The previous single-step mechanism could cause unpredictable problems,
5861 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5862 of a software single-step mechanism prevents this.
5864 *** Changes in GDB 5.2.1:
5872 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5873 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5874 Fix, by Joel Brobecker imported from mainline.
5876 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5877 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5878 Fix, by Fred Fish, imported from mainline.
5880 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5881 Surprisingly enough, it works now.
5882 By Michal Ludvig, imported from mainline.
5884 i386 hardware watchpoint support:
5885 avoid misses on second run for some targets.
5886 By Pierre Muller, imported from mainline.
5888 *** Changes in GDB 5.2:
5890 * New command "set trust-readonly-sections on[off]".
5892 This command is a hint that tells gdb that read-only sections
5893 really are read-only (ie. that their contents will not change).
5894 In this mode, gdb will go to the object file rather than the
5895 target to read memory from read-only sections (such as ".text").
5896 This can be a significant performance improvement on some
5897 (notably embedded) targets.
5899 * New command "generate-core-file" (or "gcore").
5901 This new gdb command allows the user to drop a core file of the child
5902 process state at any time. So far it's been implemented only for
5903 GNU/Linux and Solaris, but should be relatively easily ported to other
5904 hosts. Argument is core file name (defaults to core.<pid>).
5906 * New command line option
5908 GDB now accepts --pid or -p followed by a process id.
5910 * Change in command line behavior -- corefiles vs. process ids.
5912 There is a subtle behavior in the way in which GDB handles
5913 command line arguments. The first non-flag argument is always
5914 a program to debug, but the second non-flag argument may either
5915 be a corefile or a process id. Previously, GDB would attempt to
5916 open the second argument as a corefile, and if that failed, would
5917 issue a superfluous error message and then attempt to attach it as
5918 a process. Now, if the second argument begins with a non-digit,
5919 it will be treated as a corefile. If it begins with a digit,
5920 GDB will attempt to attach it as a process, and if no such process
5921 is found, will then attempt to open it as a corefile.
5923 * Changes in ARM configurations.
5925 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5926 configuration is fully multi-arch.
5928 * New native configurations
5930 ARM NetBSD arm*-*-netbsd*
5931 x86 OpenBSD i[3456]86-*-openbsd*
5932 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5933 Sparc64 running FreeBSD sparc64-*-freebsd*
5937 Sanyo XStormy16 xstormy16-elf
5939 * OBSOLETE configurations and files
5941 Configurations that have been declared obsolete in this release have
5942 been commented out. Unless there is activity to revive these
5943 configurations, the next release of GDB will have their sources
5944 permanently REMOVED.
5946 AMD 29k family via UDI a29k-amd-udi, udi29k
5947 A29K VxWorks a29k-*-vxworks
5948 AMD 29000 embedded, using EBMON a29k-none-none
5949 AMD 29000 embedded with COFF a29k-none-coff
5950 AMD 29000 embedded with a.out a29k-none-aout
5952 testsuite/gdb.hp/gdb.threads-hp/ directory
5954 * REMOVED configurations and files
5956 TI TMS320C80 tic80-*-*
5958 PowerPC Solaris powerpcle-*-solaris*
5959 PowerPC Windows NT powerpcle-*-cygwin32
5960 PowerPC Netware powerpc-*-netware*
5961 Harris/CXUX m88k m88*-harris-cxux*
5962 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5963 ns32k-utek-sysv* ns32k-utek-*
5964 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5965 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5966 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5967 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5968 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5970 * Changes to command line processing
5972 The new `--args' feature can be used to specify command-line arguments
5973 for the inferior from gdb's command line.
5975 * Changes to key bindings
5977 There is a new `operate-and-get-next' function bound to `C-o'.
5979 *** Changes in GDB 5.1.1
5981 Fix compile problem on DJGPP.
5983 Fix a problem with floating-point registers on the i386 being
5986 Fix to stop GDB crashing on .debug_str debug info.
5988 Numerous documentation fixes.
5990 Numerous testsuite fixes.
5992 *** Changes in GDB 5.1:
5994 * New native configurations
5996 Alpha FreeBSD alpha*-*-freebsd*
5997 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5998 MIPS GNU/Linux mips*-*-linux*
5999 MIPS SGI Irix 6.x mips*-sgi-irix6*
6000 ia64 AIX ia64-*-aix*
6001 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6005 Motorola 68HC11 and 68HC12 m68hc11-elf
6007 UltraSparc running GNU/Linux sparc64-*-linux*
6009 * OBSOLETE configurations and files
6011 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6012 Harris/CXUX m88k m88*-harris-cxux*
6013 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6014 ns32k-utek-sysv* ns32k-utek-*
6015 TI TMS320C80 tic80-*-*
6017 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6018 PowerPC Solaris powerpcle-*-solaris*
6019 PowerPC Windows NT powerpcle-*-cygwin32
6020 PowerPC Netware powerpc-*-netware*
6021 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6022 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6023 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6024 Apple Macintosh (MPW) host N/A
6026 stuff.c (Program to stuff files into a specially prepared space in kdb)
6027 kdb-start.c (Main loop for the standalone kernel debugger)
6029 Configurations that have been declared obsolete in this release have
6030 been commented out. Unless there is activity to revive these
6031 configurations, the next release of GDB will have their sources
6032 permanently REMOVED.
6034 * REMOVED configurations and files
6036 Altos 3068 m68*-altos-*
6037 Convex c1-*-*, c2-*-*
6039 ARM RISCix arm-*-* (as host)
6043 * GDB has been converted to ISO C.
6045 GDB's source code has been converted to ISO C. In particular, the
6046 sources are fully protoized, and rely on standard headers being
6051 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6053 * The MI enabled by default.
6055 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6056 revised and enabled by default. Packages which use GDB as a debugging
6057 engine behind a UI or another front end are encouraged to switch to
6058 using the GDB/MI interface, instead of the old annotations interface
6059 which is now deprecated.
6061 * Support for debugging Pascal programs.
6063 GDB now includes support for debugging Pascal programs. The following
6064 main features are supported:
6066 - Pascal-specific data types such as sets;
6068 - automatic recognition of Pascal sources based on file-name
6071 - Pascal-style display of data types, variables, and functions;
6073 - a Pascal expression parser.
6075 However, some important features are not yet supported.
6077 - Pascal string operations are not supported at all;
6079 - there are some problems with boolean types;
6081 - Pascal type hexadecimal constants are not supported
6082 because they conflict with the internal variables format;
6084 - support for Pascal objects and classes is not full yet;
6086 - unlike Pascal, GDB is case-sensitive for symbol names.
6088 * Changes in completion.
6090 Commands such as `shell', `run' and `set args', which pass arguments
6091 to inferior programs, now complete on file names, similar to what
6092 users expect at the shell prompt.
6094 Commands which accept locations, such as `disassemble', `print',
6095 `breakpoint', `until', etc. now complete on filenames as well as
6096 program symbols. Thus, if you type "break foob TAB", and the source
6097 files linked into the programs include `foobar.c', that file name will
6098 be one of the candidates for completion. However, file names are not
6099 considered for completion after you typed a colon that delimits a file
6100 name from a name of a function in that file, as in "break foo.c:bar".
6102 `set demangle-style' completes on available demangling styles.
6104 * New platform-independent commands:
6106 It is now possible to define a post-hook for a command as well as a
6107 hook that runs before the command. For more details, see the
6108 documentation of `hookpost' in the GDB manual.
6110 * Changes in GNU/Linux native debugging.
6112 Support for debugging multi-threaded programs has been completely
6113 revised for all platforms except m68k and sparc. You can now debug as
6114 many threads as your system allows you to have.
6116 Attach/detach is supported for multi-threaded programs.
6118 Support for SSE registers was added for x86. This doesn't work for
6119 multi-threaded programs though.
6121 * Changes in MIPS configurations.
6123 Multi-arch support is enabled for all MIPS configurations.
6125 GDB can now be built as native debugger on SGI Irix 6.x systems for
6126 debugging n32 executables. (Debugging 64-bit executables is not yet
6129 * Unified support for hardware watchpoints in all x86 configurations.
6131 Most (if not all) native x86 configurations support hardware-assisted
6132 breakpoints and watchpoints in a unified manner. This support
6133 implements debug register sharing between watchpoints, which allows to
6134 put a virtually infinite number of watchpoints on the same address,
6135 and also supports watching regions up to 16 bytes with several debug
6138 The new maintenance command `maintenance show-debug-regs' toggles
6139 debugging print-outs in functions that insert, remove, and test
6140 watchpoints and hardware breakpoints.
6142 * Changes in the DJGPP native configuration.
6144 New command ``info dos sysinfo'' displays assorted information about
6145 the CPU, OS, memory, and DPMI server.
6147 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6148 display information about segment descriptors stored in GDT, LDT, and
6151 New commands ``info dos pde'' and ``info dos pte'' display entries
6152 from Page Directory and Page Tables (for now works with CWSDPMI only).
6153 New command ``info dos address-pte'' displays the Page Table entry for
6154 a given linear address.
6156 GDB can now pass command lines longer than 126 characters to the
6157 program being debugged (requires an update to the libdbg.a library
6158 which is part of the DJGPP development kit).
6160 DWARF2 debug info is now supported.
6162 It is now possible to `step' and `next' through calls to `longjmp'.
6164 * Changes in documentation.
6166 All GDB documentation was converted to GFDL, the GNU Free
6167 Documentation License.
6169 Tracepoints-related commands are now fully documented in the GDB
6172 TUI, the Text-mode User Interface, is now documented in the manual.
6174 Tracepoints-related commands are now fully documented in the GDB
6177 The "GDB Internals" manual now has an index. It also includes
6178 documentation of `ui_out' functions, GDB coding standards, x86
6179 hardware watchpoints, and memory region attributes.
6181 * GDB's version number moved to ``version.in''
6183 The Makefile variable VERSION has been replaced by the file
6184 ``version.in''. People creating GDB distributions should update the
6185 contents of this file.
6189 GUD support is now a standard part of the EMACS distribution.
6191 *** Changes in GDB 5.0:
6193 * Improved support for debugging FP programs on x86 targets
6195 Unified and much-improved support for debugging floating-point
6196 programs on all x86 targets. In particular, ``info float'' now
6197 displays the FP registers in the same format on all x86 targets, with
6198 greater level of detail.
6200 * Improvements and bugfixes in hardware-assisted watchpoints
6202 It is now possible to watch array elements, struct members, and
6203 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6204 on x86 targets no longer erroneously trigger when the address is
6207 * Improvements in the native DJGPP version of GDB
6209 The distribution now includes all the scripts and auxiliary files
6210 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6211 machines ``out of the box''.
6213 The DJGPP version can now debug programs that use signals. It is
6214 possible to catch signals that happened in the debuggee, deliver
6215 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6216 would kill the program being debugged.) Programs that hook hardware
6217 interrupts (keyboard, timer, etc.) can also be debugged.
6219 It is now possible to debug DJGPP programs that redirect their
6220 standard handles or switch them to raw (as opposed to cooked) mode, or
6221 even close them. The command ``run < foo > bar'' works as expected,
6222 and ``info terminal'' reports useful information about the debuggee's
6223 terminal, including raw/cooked mode, redirection, etc.
6225 The DJGPP version now uses termios functions for console I/O, which
6226 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6229 DOS-style file names with drive letters are now fully supported by
6232 It is now possible to debug DJGPP programs that switch their working
6233 directory. It is also possible to rerun the debuggee any number of
6234 times without restarting GDB; thus, you can use the same setup,
6235 breakpoints, etc. for many debugging sessions.
6237 * New native configurations
6239 ARM GNU/Linux arm*-*-linux*
6240 PowerPC GNU/Linux powerpc-*-linux*
6244 Motorola MCore mcore-*-*
6245 x86 VxWorks i[3456]86-*-vxworks*
6246 PowerPC VxWorks powerpc-*-vxworks*
6247 TI TMS320C80 tic80-*-*
6249 * OBSOLETE configurations
6251 Altos 3068 m68*-altos-*
6252 Convex c1-*-*, c2-*-*
6254 ARM RISCix arm-*-* (as host)
6257 Configurations that have been declared obsolete will be commented out,
6258 but the code will be left in place. If there is no activity to revive
6259 these configurations before the next release of GDB, the sources will
6260 be permanently REMOVED.
6262 * Gould support removed
6264 Support for the Gould PowerNode and NP1 has been removed.
6266 * New features for SVR4
6268 On SVR4 native platforms (such as Solaris), if you attach to a process
6269 without first loading a symbol file, GDB will now attempt to locate and
6270 load symbols from the running process's executable file.
6272 * Many C++ enhancements
6274 C++ support has been greatly improved. Overload resolution now works properly
6275 in almost all cases. RTTI support is on the way.
6277 * Remote targets can connect to a sub-program
6279 A popen(3) style serial-device has been added. This device starts a
6280 sub-process (such as a stand-alone simulator) and then communicates
6281 with that. The sub-program to run is specified using the syntax
6282 ``|<program> <args>'' vis:
6284 (gdb) set remotedebug 1
6285 (gdb) target extended-remote |mn10300-elf-sim program-args
6287 * MIPS 64 remote protocol
6289 A long standing bug in the mips64 remote protocol where by GDB
6290 expected certain 32 bit registers (ex SR) to be transfered as 32
6291 instead of 64 bits has been fixed.
6293 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6294 added to provide backward compatibility with older versions of GDB.
6296 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6298 The command ``set remotebinarydownload'' command has been replaced by
6299 ``set remote X-packet''. Other commands in ``set remote'' family
6300 include ``set remote P-packet''.
6302 * Breakpoint commands accept ranges.
6304 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6305 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6306 ``tracepoint passcount'' also accepts a range of tracepoints.
6308 * ``apropos'' command added.
6310 The ``apropos'' command searches through command names and
6311 documentation strings, printing out matches, making it much easier to
6312 try to find a command that does what you are looking for.
6316 A new machine oriented interface (MI) has been added to GDB. This
6317 interface is designed for debug environments running GDB as a separate
6318 process. This is part of the long term libGDB project. See the
6319 "GDB/MI" chapter of the GDB manual for further information. It can be
6320 enabled by configuring with:
6322 .../configure --enable-gdbmi
6324 *** Changes in GDB-4.18:
6326 * New native configurations
6328 HP-UX 10.20 hppa*-*-hpux10.20
6329 HP-UX 11.x hppa*-*-hpux11.0*
6330 M68K GNU/Linux m68*-*-linux*
6334 Fujitsu FR30 fr30-*-elf*
6335 Intel StrongARM strongarm-*-*
6336 Mitsubishi D30V d30v-*-*
6338 * OBSOLETE configurations
6340 Gould PowerNode, NP1 np1-*-*, pn-*-*
6342 Configurations that have been declared obsolete will be commented out,
6343 but the code will be left in place. If there is no activity to revive
6344 these configurations before the next release of GDB, the sources will
6345 be permanently REMOVED.
6349 As a compatibility experiment, GDB's source files buildsym.h and
6350 buildsym.c have been converted to pure standard C, no longer
6351 containing any K&R compatibility code. We believe that all systems in
6352 use today either come with a standard C compiler, or have a GCC port
6353 available. If this is not true, please report the affected
6354 configuration to bug-gdb@gnu.org immediately. See the README file for
6355 information about getting a standard C compiler if you don't have one
6360 GDB now uses readline 2.2.
6362 * set extension-language
6364 You can now control the mapping between filename extensions and source
6365 languages by using the `set extension-language' command. For instance,
6366 you can ask GDB to treat .c files as C++ by saying
6367 set extension-language .c c++
6368 The command `info extensions' lists all of the recognized extensions
6369 and their associated languages.
6371 * Setting processor type for PowerPC and RS/6000
6373 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6374 you can use the `set processor' command to specify what variant of the
6375 PowerPC family you are debugging. The command
6379 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6380 following PowerPC and RS6000 variants:
6382 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6383 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6385 403GC IBM PowerPC 403GC
6386 505 Motorola PowerPC 505
6387 860 Motorola PowerPC 860 or 850
6388 601 Motorola PowerPC 601
6389 602 Motorola PowerPC 602
6390 603 Motorola/IBM PowerPC 603 or 603e
6391 604 Motorola PowerPC 604 or 604e
6392 750 Motorola/IBM PowerPC 750 or 750
6394 At the moment, this command just tells GDB what to name the
6395 special-purpose processor registers. Since almost all the affected
6396 registers are inaccessible to user-level programs, this command is
6397 only useful for remote debugging in its present form.
6401 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6402 more extensive support for HP-UX. Added features include shared
6403 library support, kernel threads and hardware watchpoints for 11.00,
6404 support for HP's ANSI C and C++ compilers, and a compatibility mode
6405 for xdb and dbx commands.
6409 HP's donation includes the new concept of catchpoints, which is a
6410 generalization of the old catch command. On HP-UX, it is now possible
6411 to catch exec, fork, and vfork, as well as library loading.
6413 This means that the existing catch command has changed; its first
6414 argument now specifies the type of catch to be set up. See the
6415 output of "help catch" for a list of catchpoint types.
6417 * Debugging across forks
6419 On HP-UX, you can choose which process to debug when a fork() happens
6424 HP has donated a curses-based terminal user interface (TUI). To get
6425 it, build with --enable-tui. Although this can be enabled for any
6426 configuration, at present it only works for native HP debugging.
6428 * GDB remote protocol additions
6430 A new protocol packet 'X' that writes binary data is now available.
6431 Default behavior is to try 'X', then drop back to 'M' if the stub
6432 fails to respond. The settable variable `remotebinarydownload'
6433 allows explicit control over the use of 'X'.
6435 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6436 full 64-bit address. The command
6438 set remoteaddresssize 32
6440 can be used to revert to the old behaviour. For existing remote stubs
6441 the change should not be noticed, as the additional address information
6444 In order to assist in debugging stubs, you may use the maintenance
6445 command `packet' to send any text string to the stub. For instance,
6447 maint packet heythere
6449 sends the packet "$heythere#<checksum>". Note that it is very easy to
6450 disrupt a debugging session by sending the wrong packet at the wrong
6453 The compare-sections command allows you to compare section data on the
6454 target to what is in the executable file without uploading or
6455 downloading, by comparing CRC checksums.
6457 * Tracing can collect general expressions
6459 You may now collect general expressions at tracepoints. This requires
6460 further additions to the target-side stub; see tracepoint.c and
6461 doc/agentexpr.texi for further details.
6463 * mask-address variable for Mips
6465 For Mips targets, you may control the zeroing of the upper 32 bits of
6466 a 64-bit address by entering `set mask-address on'. This is mainly
6467 of interest to users of embedded R4xxx and R5xxx processors.
6469 * Higher serial baud rates
6471 GDB's serial code now allows you to specify baud rates 57600, 115200,
6472 230400, and 460800 baud. (Note that your host system may not be able
6473 to achieve all of these rates.)
6477 The i960 configuration now includes an initial implementation of a
6478 builtin simulator, contributed by Jim Wilson.
6481 *** Changes in GDB-4.17:
6483 * New native configurations
6485 Alpha GNU/Linux alpha*-*-linux*
6486 Unixware 2.x i[3456]86-unixware2*
6487 Irix 6.x mips*-sgi-irix6*
6488 PowerPC GNU/Linux powerpc-*-linux*
6489 PowerPC Solaris powerpcle-*-solaris*
6490 Sparc GNU/Linux sparc-*-linux*
6491 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6495 Argonaut Risc Chip (ARC) arc-*-*
6496 Hitachi H8/300S h8300*-*-*
6497 Matsushita MN10200 w/simulator mn10200-*-*
6498 Matsushita MN10300 w/simulator mn10300-*-*
6499 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6500 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6501 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6502 Mitsubishi D10V w/simulator d10v-*-*
6503 Mitsubishi M32R/D w/simulator m32r-*-elf*
6504 Tsqware Sparclet sparclet-*-*
6505 NEC V850 w/simulator v850-*-*
6507 * New debugging protocols
6509 ARM with RDI protocol arm*-*-*
6510 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6511 DDB and LSI variants of PMON protocol mips*-*-*
6512 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6513 PowerPC with SDS protocol powerpc{,le}-*-eabi
6514 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6518 All configurations can now understand and use the DWARF 2 debugging
6519 format. The choice is automatic, if the symbol file contains DWARF 2
6524 GDB now includes basic Java language support. This support is
6525 only useful with Java compilers that produce native machine code.
6527 * solib-absolute-prefix and solib-search-path
6529 For SunOS and SVR4 shared libraries, you may now set the prefix for
6530 loading absolute shared library symbol files, and the search path for
6531 locating non-absolute shared library symbol files.
6533 * Live range splitting
6535 GDB can now effectively debug code for which GCC has performed live
6536 range splitting as part of its optimization. See gdb/doc/LRS for
6537 more details on the expected format of the stabs information.
6541 GDB's support for the GNU Hurd, including thread debugging, has been
6542 updated to work with current versions of the Hurd.
6546 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6547 instruction set. ARM GDB automatically detects when Thumb
6548 instructions are in use, and adjusts disassembly and backtracing
6553 GDB's MIPS target configurations now handle the MIP16 16-bit
6558 GDB now includes support for overlays; if an executable has been
6559 linked such that multiple sections are based at the same address, GDB
6560 will decide which section to use for symbolic info. You can choose to
6561 control the decision manually, using overlay commands, or implement
6562 additional target-side support and use "overlay load-target" to bring
6563 in the overlay mapping. Do "help overlay" for more detail.
6567 The command "info symbol <address>" displays information about
6568 the symbol at the specified address.
6572 The standard remote protocol now includes an extension that allows
6573 asynchronous collection and display of trace data. This requires
6574 extensive support in the target-side debugging stub. Tracing mode
6575 includes a new interaction mode in GDB and new commands: see the
6576 file tracepoint.c for more details.
6580 Configurations for embedded MIPS now include a simulator contributed
6581 by Cygnus Solutions. The simulator supports the instruction sets
6582 of most MIPS variants.
6586 Sparc configurations may now include the ERC32 simulator contributed
6587 by the European Space Agency. The simulator is not built into
6588 Sparc targets by default; configure with --enable-sim to include it.
6592 For target configurations that may include multiple variants of a
6593 basic architecture (such as MIPS and SH), you may now set the
6594 architecture explicitly. "set arch" sets, "info arch" lists
6595 the possible architectures.
6597 *** Changes in GDB-4.16:
6599 * New native configurations
6601 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6602 M68K NetBSD m68k-*-netbsd*
6603 PowerPC AIX 4.x powerpc-*-aix*
6604 PowerPC MacOS powerpc-*-macos*
6605 PowerPC Windows NT powerpcle-*-cygwin32
6606 RS/6000 AIX 4.x rs6000-*-aix4*
6610 ARM with RDP protocol arm-*-*
6611 I960 with MON960 i960-*-coff
6612 MIPS VxWorks mips*-*-vxworks*
6613 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6614 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6616 Matra Sparclet sparclet-*-*
6620 The powerpc-eabi configuration now includes the PSIM simulator,
6621 contributed by Andrew Cagney, with assistance from Mike Meissner.
6622 PSIM is a very elaborate model of the PowerPC, including not only
6623 basic instruction set execution, but also details of execution unit
6624 performance and I/O hardware. See sim/ppc/README for more details.
6628 GDB now works with Solaris 2.5.
6630 * Windows 95/NT native
6632 GDB will now work as a native debugger on Windows 95 and Windows NT.
6633 To build it from source, you must use the "gnu-win32" environment,
6634 which uses a DLL to emulate enough of Unix to run the GNU tools.
6635 Further information, binaries, and sources are available at
6636 ftp.cygnus.com, under pub/gnu-win32.
6638 * dont-repeat command
6640 If a user-defined command includes the command `dont-repeat', then the
6641 command will not be repeated if the user just types return. This is
6642 useful if the command is time-consuming to run, so that accidental
6643 extra keystrokes don't run the same command many times.
6645 * Send break instead of ^C
6647 The standard remote protocol now includes an option to send a break
6648 rather than a ^C to the target in order to interrupt it. By default,
6649 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6651 * Remote protocol timeout
6653 The standard remote protocol includes a new variable `remotetimeout'
6654 that allows you to set the number of seconds before GDB gives up trying
6655 to read from the target. The default value is 2.
6657 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6659 By default GDB will automatically keep track of objects as they are
6660 loaded and unloaded by the dynamic linker. By using the command `set
6661 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6662 when shared library events occur, thus allowing you to set breakpoints
6663 in shared libraries which are explicitly loaded by the inferior.
6665 Note this feature does not work on hpux8. On hpux9 you must link
6666 /usr/lib/end.o into your program. This feature should work
6667 automatically on hpux10.
6669 * Irix 5.x hardware watchpoint support
6671 Irix 5 configurations now support the use of hardware watchpoints.
6673 * Mips protocol "SYN garbage limit"
6675 When debugging a Mips target using the `target mips' protocol, you
6676 may set the number of characters that GDB will ignore by setting
6677 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6678 every character. The default value is 1050.
6680 * Recording and replaying remote debug sessions
6682 If you set `remotelogfile' to the name of a file, gdb will write to it
6683 a recording of a remote debug session. This recording may then be
6684 replayed back to gdb using "gdbreplay". See gdbserver/README for
6685 details. This is useful when you have a problem with GDB while doing
6686 remote debugging; you can make a recording of the session and send it
6687 to someone else, who can then recreate the problem.
6689 * Speedups for remote debugging
6691 GDB includes speedups for downloading and stepping MIPS systems using
6692 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6693 and more efficient S-record downloading.
6695 * Memory use reductions and statistics collection
6697 GDB now uses less memory and reports statistics about memory usage.
6698 Try the `maint print statistics' command, for example.
6700 *** Changes in GDB-4.15:
6702 * Psymtabs for XCOFF
6704 The symbol reader for AIX GDB now uses partial symbol tables. This
6705 can greatly improve startup time, especially for large executables.
6707 * Remote targets use caching
6709 Remote targets now use a data cache to speed up communication with the
6710 remote side. The data cache could lead to incorrect results because
6711 it doesn't know about volatile variables, thus making it impossible to
6712 debug targets which use memory mapped I/O devices. `set remotecache
6713 off' turns the data cache off.
6715 * Remote targets may have threads
6717 The standard remote protocol now includes support for multiple threads
6718 in the target system, using new protocol commands 'H' and 'T'. See
6719 gdb/remote.c for details.
6723 If GDB is configured with `--enable-netrom', then it will include
6724 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6725 acts as though it is a bank of ROM on the target board, but you can
6726 write into it over the network. GDB's support consists only of
6727 support for fast loading into the emulated ROM; to debug, you must use
6728 another protocol, such as standard remote protocol. The usual
6729 sequence is something like
6731 target nrom <netrom-hostname>
6733 target remote <netrom-hostname>:1235
6737 GDB now includes support for the Apple Macintosh, as a host only. It
6738 may be run as either an MPW tool or as a standalone application, and
6739 it can debug through the serial port. All the usual GDB commands are
6740 available, but to the target command, you must supply "serial" as the
6741 device type instead of "/dev/ttyXX". See mpw-README in the main
6742 directory for more information on how to build. The MPW configuration
6743 scripts */mpw-config.in support only a few targets, and only the
6744 mips-idt-ecoff target has been tested.
6748 GDB configuration now uses autoconf. This is not user-visible,
6749 but does simplify configuration and building.
6753 GDB now supports hpux10.
6755 *** Changes in GDB-4.14:
6757 * New native configurations
6759 x86 FreeBSD i[345]86-*-freebsd
6760 x86 NetBSD i[345]86-*-netbsd
6761 NS32k NetBSD ns32k-*-netbsd
6762 Sparc NetBSD sparc-*-netbsd
6766 A29K VxWorks a29k-*-vxworks
6767 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6768 CPU32 EST-300 emulator m68*-*-est*
6769 PowerPC ELF powerpc-*-elf
6772 * Alpha OSF/1 support for procfs
6774 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6775 possible to attach to running processes. As the mounting of the /proc
6776 filesystem is optional on the Alpha, GDB automatically determines
6777 the availability of /proc during startup. This can lead to problems
6778 if /proc is unmounted after GDB has been started.
6780 * Arguments to user-defined commands
6782 User commands may accept up to 10 arguments separated by whitespace.
6783 Arguments are accessed within the user command via $arg0..$arg9. A
6786 print $arg0 + $arg1 + $arg2
6788 To execute the command use:
6791 Defines the command "adder" which prints the sum of its three arguments.
6792 Note the arguments are text substitutions, so they may reference variables,
6793 use complex expressions, or even perform inferior function calls.
6795 * New `if' and `while' commands
6797 This makes it possible to write more sophisticated user-defined
6798 commands. Both commands take a single argument, which is the
6799 expression to evaluate, and must be followed by the commands to
6800 execute, one per line, if the expression is nonzero, the list being
6801 terminated by the word `end'. The `if' command list may include an
6802 `else' word, which causes the following commands to be executed only
6803 if the expression is zero.
6805 * Fortran source language mode
6807 GDB now includes partial support for Fortran 77. It will recognize
6808 Fortran programs and can evaluate a subset of Fortran expressions, but
6809 variables and functions may not be handled correctly. GDB will work
6810 with G77, but does not yet know much about symbols emitted by other
6813 * Better HPUX support
6815 Most debugging facilities now work on dynamic executables for HPPAs
6816 running hpux9 or later. You can attach to running dynamically linked
6817 processes, but by default the dynamic libraries will be read-only, so
6818 for instance you won't be able to put breakpoints in them. To change
6819 that behavior do the following before running the program:
6825 This will cause the libraries to be mapped private and read-write.
6826 To revert to the normal behavior, do this:
6832 You cannot set breakpoints or examine data in the library until after
6833 the library is loaded if the function/data symbols do not have
6836 GDB can now also read debug symbols produced by the HP C compiler on
6837 HPPAs (sorry, no C++, Fortran or 68k support).
6839 * Target byte order now dynamically selectable
6841 You can choose which byte order to use with a target system, via the
6842 commands "set endian big" and "set endian little", and you can see the
6843 current setting by using "show endian". You can also give the command
6844 "set endian auto", in which case GDB will use the byte order
6845 associated with the executable. Currently, only embedded MIPS
6846 configurations support dynamic selection of target byte order.
6848 * New DOS host serial code
6850 This version uses DPMI interrupts to handle buffered I/O, so you
6851 no longer need to run asynctsr when debugging boards connected to
6854 *** Changes in GDB-4.13:
6856 * New "complete" command
6858 This lists all the possible completions for the rest of the line, if it
6859 were to be given as a command itself. This is intended for use by emacs.
6861 * Trailing space optional in prompt
6863 "set prompt" no longer adds a space for you after the prompt you set. This
6864 allows you to set a prompt which ends in a space or one that does not.
6866 * Breakpoint hit counts
6868 "info break" now displays a count of the number of times the breakpoint
6869 has been hit. This is especially useful in conjunction with "ignore"; you
6870 can ignore a large number of breakpoint hits, look at the breakpoint info
6871 to see how many times the breakpoint was hit, then run again, ignoring one
6872 less than that number, and this will get you quickly to the last hit of
6875 * Ability to stop printing at NULL character
6877 "set print null-stop" will cause GDB to stop printing the characters of
6878 an array when the first NULL is encountered. This is useful when large
6879 arrays actually contain only short strings.
6881 * Shared library breakpoints
6883 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6884 breakpoints in shared libraries before the executable is run.
6886 * Hardware watchpoints
6888 There is a new hardware breakpoint for the watch command for sparclite
6889 targets. See gdb/sparclite/hw_breakpoint.note.
6891 Hardware watchpoints are also now supported under GNU/Linux.
6895 Annotations have been added. These are for use with graphical interfaces,
6896 and are still experimental. Currently only gdba.el uses these.
6898 * Improved Irix 5 support
6900 GDB now works properly with Irix 5.2.
6902 * Improved HPPA support
6904 GDB now works properly with the latest GCC and GAS.
6906 * New native configurations
6908 Sequent PTX4 i[34]86-sequent-ptx4
6909 HPPA running OSF/1 hppa*-*-osf*
6910 Atari TT running SVR4 m68*-*-sysv4*
6911 RS/6000 LynxOS rs6000-*-lynxos*
6915 OS/9000 i[34]86-*-os9k
6916 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6919 * Hitachi SH7000 and E7000-PC ICE support
6921 There is now support for communicating with the Hitachi E7000-PC ICE.
6922 This is available automatically when GDB is configured for the SH.
6926 As usual, a variety of small fixes and improvements, both generic
6927 and configuration-specific. See the ChangeLog for more detail.
6929 *** Changes in GDB-4.12:
6931 * Irix 5 is now supported
6935 GDB-4.12 on the HPPA has a number of changes which make it unable
6936 to debug the output from the currently released versions of GCC and
6937 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6938 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6939 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6942 *** Changes in GDB-4.11:
6944 * User visible changes:
6948 The "set remotedebug" option is now consistent between the mips remote
6949 target, remote targets using the gdb-specific protocol, UDI (AMD's
6950 debug protocol for the 29k) and the 88k bug monitor. It is now an
6951 integer specifying a debug level (normally 0 or 1, but 2 means more
6952 debugging info for the mips target).
6954 * DEC Alpha native support
6956 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6957 debug info, but GDB works fairly well with the DEC compiler and should
6958 work with a future GCC release. See the README file for a few
6959 Alpha-specific notes.
6961 * Preliminary thread implementation
6963 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6965 * LynxOS native and target support for 386
6967 This release has been hosted on LynxOS 2.2, and also can be configured
6968 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6971 * Improvements in C++ mangling/demangling.
6973 This release has much better g++ debugging, specifically in name
6974 mangling/demangling, virtual function calls, print virtual table,
6975 call methods, ...etc.
6977 *** Changes in GDB-4.10:
6979 * User visible changes:
6981 Remote debugging using the GDB-specific (`target remote') protocol now
6982 supports the `load' command. This is only useful if you have some
6983 other way of getting the stub to the target system, and you can put it
6984 somewhere in memory where it won't get clobbered by the download.
6986 Filename completion now works.
6988 When run under emacs mode, the "info line" command now causes the
6989 arrow to point to the line specified. Also, "info line" prints
6990 addresses in symbolic form (as well as hex).
6992 All vxworks based targets now support a user settable option, called
6993 vxworks-timeout. This option represents the number of seconds gdb
6994 should wait for responses to rpc's. You might want to use this if
6995 your vxworks target is, perhaps, a slow software simulator or happens
6996 to be on the far side of a thin network line.
7000 This release contains support for using a DEC alpha as a GDB host for
7001 cross debugging. Native alpha debugging is not supported yet.
7004 *** Changes in GDB-4.9:
7008 This is the first GDB release which is accompanied by a matching testsuite.
7009 The testsuite requires installation of dejagnu, which should be available
7010 via ftp from most sites that carry GNU software.
7014 'Cfront' style demangling has had its name changed to 'ARM' style, to
7015 emphasize that it was written from the specifications in the C++ Annotated
7016 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7017 disclaimers, it still generated too much confusion with users attempting to
7018 use gdb with AT&T cfront.
7022 GDB now uses a standard remote interface to a simulator library.
7023 So far, the library contains simulators for the Zilog Z8001/2, the
7024 Hitachi H8/300, H8/500 and Super-H.
7026 * New targets supported
7028 H8/300 simulator h8300-hitachi-hms or h8300hms
7029 H8/500 simulator h8500-hitachi-hms or h8500hms
7030 SH simulator sh-hitachi-hms or sh
7031 Z8000 simulator z8k-zilog-none or z8ksim
7032 IDT MIPS board over serial line mips-idt-ecoff
7034 Cross-debugging to GO32 targets is supported. It requires a custom
7035 version of the i386-stub.c module which is integrated with the
7036 GO32 memory extender.
7038 * New remote protocols
7040 MIPS remote debugging protocol.
7042 * New source languages supported
7044 This version includes preliminary support for Chill, a Pascal like language
7045 used by telecommunications companies. Chill support is also being integrated
7046 into the GNU compiler, but we don't know when it will be publically available.
7049 *** Changes in GDB-4.8:
7051 * HP Precision Architecture supported
7053 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7054 version of this support was available as a set of patches from the
7055 University of Utah. GDB does not support debugging of programs
7056 compiled with the HP compiler, because HP will not document their file
7057 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7058 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7060 Many problems in the preliminary version have been fixed.
7062 * Faster and better demangling
7064 We have improved template demangling and fixed numerous bugs in the GNU style
7065 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7066 character types (wchar_t) are now supported. Demangling of each symbol is now
7067 only done once, and is cached when the symbol table for a file is read in.
7068 This results in a small increase in memory usage for C programs, a moderate
7069 increase in memory usage for C++ programs, and a fantastic speedup in
7072 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7073 from the specifications in the Annotated Reference Manual, which AT&T's
7074 compiler does not actually implement.
7076 * G++ multiple inheritance compiler problem
7078 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7079 inheritance lattices was reworked to properly discover ambiguities. We
7080 recently found an example which causes this new algorithm to fail in a
7081 very subtle way, producing bad debug information for those classes.
7082 The file 'gcc.patch' (in this directory) can be applied to gcc to
7083 circumvent the problem. A future GCC release will contain a complete
7086 The previous G++ debug info problem (mentioned below for the gdb-4.7
7087 release) is fixed in gcc version 2.3.2.
7089 * Improved configure script
7091 The `configure' script will now attempt to guess your system type if
7092 you don't supply a host system type. The old scheme of supplying a
7093 host system triplet is preferable over using this. All the magic is
7094 done in the new `config.guess' script. Examine it for details.
7096 We have also brought our configure script much more in line with the FSF's
7097 version. It now supports the --with-xxx options. In particular,
7098 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7099 The resulting GDB will not be able to read arbitrary object file formats --
7100 only the format ``expected'' to be used on the configured target system.
7101 We hope to make this the default in a future release.
7103 * Documentation improvements
7105 There's new internal documentation on how to modify GDB, and how to
7106 produce clean changes to the code. We implore people to read it
7107 before submitting changes.
7109 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7110 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7111 `info' files are also provided. To build `info' files from scratch,
7112 you will need the latest `makeinfo' release, which will be available in
7113 a future texinfo-X.Y release.
7115 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7116 We're not sure exactly which versions have this problem, but it has
7117 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7118 or better. If that isn't possible, there is a patch in
7119 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7120 around this problem.
7124 GDB now supports array constants that can be used in expressions typed in by
7125 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7126 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7129 The new directory `gdb/sparclite' contains a program that demonstrates
7130 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7132 * New native hosts supported
7134 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7135 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7137 * New targets supported
7139 AMD 29k family via UDI a29k-amd-udi or udi29k
7141 * New file formats supported
7143 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7144 HPUX core files, and SCO 3.2v2 core files.
7148 Attaching to processes now works again; thanks for the many bug reports.
7150 We have also stomped on a bunch of core dumps caused by
7151 printf_filtered("%s") problems.
7153 We eliminated a copyright problem on the rpc and ptrace header files
7154 for VxWorks, which was discovered at the last minute during the 4.7
7155 release. You should now be able to build a VxWorks GDB.
7157 You can now interrupt gdb while an attached process is running. This
7158 will cause the attached process to stop, and give control back to GDB.
7160 We fixed problems caused by using too many file descriptors
7161 for reading symbols from object files and libraries. This was
7162 especially a problem for programs that used many (~100) shared
7165 The `step' command now only enters a subroutine if there is line number
7166 information for the subroutine. Otherwise it acts like the `next'
7167 command. Previously, `step' would enter subroutines if there was
7168 any debugging information about the routine. This avoids problems
7169 when using `cc -g1' on MIPS machines.
7171 * Internal improvements
7173 GDB's internal interfaces have been improved to make it easier to support
7174 debugging of multiple languages in the future.
7176 GDB now uses a common structure for symbol information internally.
7177 Minimal symbols (derived from linkage symbols in object files), partial
7178 symbols (from a quick scan of debug information), and full symbols
7179 contain a common subset of information, making it easier to write
7180 shared code that handles any of them.
7182 * New command line options
7184 We now accept --silent as an alias for --quiet.
7188 The memory-mapped-malloc library is now licensed under the GNU Library
7189 General Public License.
7191 *** Changes in GDB-4.7:
7193 * Host/native/target split
7195 GDB has had some major internal surgery to untangle the support for
7196 hosts and remote targets. Now, when you configure GDB for a remote
7197 target, it will no longer load in all of the support for debugging
7198 local programs on the host. When fully completed and tested, this will
7199 ensure that arbitrary host/target combinations are possible.
7201 The primary conceptual shift is to separate the non-portable code in
7202 GDB into three categories. Host specific code is required any time GDB
7203 is compiled on that host, regardless of the target. Target specific
7204 code relates to the peculiarities of the target, but can be compiled on
7205 any host. Native specific code is everything else: it can only be
7206 built when the host and target are the same system. Child process
7207 handling and core file support are two common `native' examples.
7209 GDB's use of /proc for controlling Unix child processes is now cleaner.
7210 It has been split out into a single module under the `target_ops' vector,
7211 plus two native-dependent functions for each system that uses /proc.
7213 * New hosts supported
7215 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7216 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7217 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7219 * New targets supported
7221 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7222 68030 and CPU32 m68030-*-*, m68332-*-*
7224 * New native hosts supported
7226 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7227 (386bsd is not well tested yet)
7228 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7230 * New file formats supported
7232 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7233 supports reading of `a.out.adobe' object files, which are an a.out
7234 format extended with minimal information about multiple sections.
7238 `show copying' is the same as the old `info copying'.
7239 `show warranty' is the same as `info warrantee'.
7240 These were renamed for consistency. The old commands continue to work.
7242 `info handle' is a new alias for `info signals'.
7244 You can now define pre-command hooks, which attach arbitrary command
7245 scripts to any command. The commands in the hook will be executed
7246 prior to the user's command. You can also create a hook which will be
7247 executed whenever the program stops. See gdb.texinfo.
7251 We now deal with Cfront style name mangling, and can even extract type
7252 info from mangled symbols. GDB can automatically figure out which
7253 symbol mangling style your C++ compiler uses.
7255 Calling of methods and virtual functions has been improved as well.
7259 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7260 fixed. This was due to mishandling of the extra N_SO stabs output
7263 We also finally got Ultrix 4.2 running in house, and fixed core file
7264 support, with help from a dozen people on the net.
7266 John M. Farrell discovered that the reason that single-stepping was so
7267 slow on all of the Mips based platforms (primarily SGI and DEC) was
7268 that we were trying to demangle and lookup a symbol used for internal
7269 purposes on every instruction that was being stepped through. Changing
7270 the name of that symbol so that it couldn't be mistaken for a C++
7271 mangled symbol sped things up a great deal.
7273 Rich Pixley sped up symbol lookups in general by getting much smarter
7274 about when C++ symbol mangling is necessary. This should make symbol
7275 completion (TAB on the command line) much faster. It's not as fast as
7276 we'd like, but it's significantly faster than gdb-4.6.
7280 A new user controllable variable 'call_scratch_address' can
7281 specify the location of a scratch area to be used when GDB
7282 calls a function in the target. This is necessary because the
7283 usual method of putting the scratch area on the stack does not work
7284 in systems that have separate instruction and data spaces.
7286 We integrated changes to support the 29k UDI (Universal Debugger
7287 Interface), but discovered at the last minute that we didn't have all
7288 of the appropriate copyright paperwork. We are working with AMD to
7289 resolve this, and hope to have it available soon.
7293 We have sped up the remote serial line protocol, especially for targets
7294 with lots of registers. It now supports a new `expedited status' ('T')
7295 message which can be used in place of the existing 'S' status message.
7296 This allows the remote stub to send only the registers that GDB
7297 needs to make a quick decision about single-stepping or conditional
7298 breakpoints, eliminating the need to fetch the entire register set for
7299 each instruction being stepped through.
7301 The GDB remote serial protocol now implements a write-through cache for
7302 registers, only re-reading the registers if the target has run.
7304 There is also a new remote serial stub for SPARC processors. You can
7305 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7306 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7307 processor with a serial port.
7311 Configure.in files have become much easier to read and modify. A new
7312 `table driven' format makes it more obvious what configurations are
7313 supported, and what files each one uses.
7317 There is a new opcodes library which will eventually contain all of the
7318 disassembly routines and opcode tables. At present, it only contains
7319 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7320 disassembler (binutils/objdump) to share these routines.
7322 The libiberty library is now copylefted under the GNU Library General
7323 Public License. This allows more liberal use, and was done so libg++
7324 can use it. This makes no difference to GDB, since the Library License
7325 grants all the rights from the General Public License.
7329 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7330 reference to the stabs symbol info used by the debugger. It is (as far
7331 as we know) the only published document on this fascinating topic. We
7332 encourage you to read it, compare it to the stabs information on your
7333 system, and send improvements on the document in general (to
7334 bug-gdb@prep.ai.mit.edu).
7336 And, of course, many bugs have been fixed.
7339 *** Changes in GDB-4.6:
7341 * Better support for C++ function names
7343 GDB now accepts as input the "demangled form" of C++ overloaded function
7344 names and member function names, and can do command completion on such names
7345 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7346 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7347 Make use of command completion, it is your friend.
7349 GDB also now accepts a variety of C++ mangled symbol formats. They are
7350 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7351 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7352 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7353 for the list of formats.
7355 * G++ symbol mangling problem
7357 Recent versions of gcc have a bug in how they emit debugging information for
7358 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7359 directory) can be applied to gcc to fix the problem. Alternatively, if you
7360 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7361 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7362 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7365 * New 'maintenance' command
7367 All of the commands related to hacking GDB internals have been moved out of
7368 the main command set, and now live behind the 'maintenance' command. This
7369 can also be abbreviated as 'mt'. The following changes were made:
7371 dump-me -> maintenance dump-me
7372 info all-breakpoints -> maintenance info breakpoints
7373 printmsyms -> maintenance print msyms
7374 printobjfiles -> maintenance print objfiles
7375 printpsyms -> maintenance print psymbols
7376 printsyms -> maintenance print symbols
7378 The following commands are new:
7380 maintenance demangle Call internal GDB demangler routine to
7381 demangle a C++ link name and prints the result.
7382 maintenance print type Print a type chain for a given symbol
7384 * Change to .gdbinit file processing
7386 We now read the $HOME/.gdbinit file before processing the argv arguments
7387 (e.g. reading symbol files or core files). This allows global parameters to
7388 be set, which will apply during the symbol reading. The ./.gdbinit is still
7389 read after argv processing.
7391 * New hosts supported
7393 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7395 GNU/Linux support i386-unknown-linux or linux
7397 We are also including code to support the HP/PA running BSD and HPUX. This
7398 is almost guaranteed not to work, as we didn't have time to test or build it
7399 for this release. We are including it so that the more adventurous (or
7400 masochistic) of you can play with it. We also had major problems with the
7401 fact that the compiler that we got from HP doesn't support the -g option.
7404 * New targets supported
7406 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7408 * More smarts about finding #include files
7410 GDB now remembers the compilation directory for all include files, and for
7411 all files from which C is generated (like yacc and lex sources). This
7412 greatly improves GDB's ability to find yacc/lex sources, and include files,
7413 especially if you are debugging your program from a directory different from
7414 the one that contains your sources.
7416 We also fixed a bug which caused difficulty with listing and setting
7417 breakpoints in include files which contain C code. (In the past, you had to
7418 try twice in order to list an include file that you hadn't looked at before.)
7420 * Interesting infernals change
7422 GDB now deals with arbitrary numbers of sections, where the symbols for each
7423 section must be relocated relative to that section's landing place in the
7424 target's address space. This work was needed to support ELF with embedded
7425 stabs used by Solaris-2.0.
7427 * Bug fixes (of course!)
7429 There have been loads of fixes for the following things:
7430 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7431 i960, stabs, DOS(GO32), procfs, etc...
7433 See the ChangeLog for details.
7435 *** Changes in GDB-4.5:
7437 * New machines supported (host and target)
7439 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7441 SGI Irix-4.x mips-sgi-irix4 or iris4
7443 * New malloc package
7445 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7446 Mmalloc is capable of handling multiple heaps of memory. It is also
7447 capable of saving a heap to a file, and then mapping it back in later.
7448 This can be used to greatly speedup the startup of GDB by using a
7449 pre-parsed symbol table which lives in a mmalloc managed heap. For
7450 more details, please read mmalloc/mmalloc.texi.
7454 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7455 'help info proc' for details.
7457 * MIPS ecoff symbol table format
7459 The code that reads MIPS symbol table format is now supported on all hosts.
7460 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7463 * File name changes for MS-DOS
7465 Many files in the config directories have been renamed to make it easier to
7466 support GDB on MS-DOSe systems (which have very restrictive file name
7467 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7468 environment) is close to working but has some remaining problems. Note
7469 that debugging of DOS programs is not supported, due to limitations
7470 in the ``operating system'', but it can be used to host cross-debugging.
7472 * Cross byte order fixes
7474 Many fixes have been made to support cross debugging of Sparc and MIPS
7475 targets from hosts whose byte order differs.
7477 * New -mapped and -readnow options
7479 If memory-mapped files are available on your system through the 'mmap'
7480 system call, you can use the -mapped option on the `file' or
7481 `symbol-file' commands to cause GDB to write the symbols from your
7482 program into a reusable file. If the program you are debugging is
7483 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7484 Future GDB debugging sessions will notice the presence of this file,
7485 and will quickly map in symbol information from it, rather than reading
7486 the symbol table from the executable program. Using the '-mapped'
7487 option in a GDB `file' or `symbol-file' command has the same effect as
7488 starting GDB with the '-mapped' command-line option.
7490 You can cause GDB to read the entire symbol table immediately by using
7491 the '-readnow' option with any of the commands that load symbol table
7492 information (or on the GDB command line). This makes the command
7493 slower, but makes future operations faster.
7495 The -mapped and -readnow options are typically combined in order to
7496 build a `fred.syms' file that contains complete symbol information.
7497 A simple GDB invocation to do nothing but build a `.syms' file for future
7500 gdb -batch -nx -mapped -readnow programname
7502 The `.syms' file is specific to the host machine on which GDB is run.
7503 It holds an exact image of GDB's internal symbol table. It cannot be
7504 shared across multiple host platforms.
7506 * longjmp() handling
7508 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7509 siglongjmp() without losing control. This feature has not yet been ported to
7510 all systems. It currently works on many 386 platforms, all MIPS-based
7511 platforms (SGI, DECstation, etc), and Sun3/4.
7515 Preliminary work has been put in to support the new Solaris OS from Sun. At
7516 this time, it can control and debug processes, but it is not capable of
7521 As always, many many bug fixes. The major areas were with g++, and mipsread.
7522 People using the MIPS-based platforms should experience fewer mysterious
7523 crashes and trashed symbol tables.
7525 *** Changes in GDB-4.4:
7527 * New machines supported (host and target)
7529 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7531 BSD Reno on Vax vax-dec-bsd
7532 Ultrix on Vax vax-dec-ultrix
7534 * New machines supported (target)
7536 AMD 29000 embedded, using EBMON a29k-none-none
7540 GDB continues to improve its handling of C++. `References' work better.
7541 The demangler has also been improved, and now deals with symbols mangled as
7542 per the Annotated C++ Reference Guide.
7544 GDB also now handles `stabs' symbol information embedded in MIPS
7545 `ecoff' symbol tables. Since the ecoff format was not easily
7546 extensible to handle new languages such as C++, this appeared to be a
7547 good way to put C++ debugging info into MIPS binaries. This option
7548 will be supported in the GNU C compiler, version 2, when it is
7551 * New features for SVR4
7553 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7554 shared libraries. Debugging dynamically linked programs should present
7555 only minor differences from debugging statically linked programs.
7557 The `info proc' command will print out information about any process
7558 on an SVR4 system (including the one you are debugging). At the moment,
7559 it prints the address mappings of the process.
7561 If you bring up GDB on another SVR4 system, please send mail to
7562 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7564 * Better dynamic linking support in SunOS
7566 Reading symbols from shared libraries which contain debugging symbols
7567 now works properly. However, there remain issues such as automatic
7568 skipping of `transfer vector' code during function calls, which
7569 make it harder to debug code in a shared library, than to debug the
7570 same code linked statically.
7574 GDB is now using the latest `getopt' routines from the FSF. This
7575 version accepts the -- prefix for options with long names. GDB will
7576 continue to accept the old forms (-option and +option) as well.
7577 Various single letter abbreviations for options have been explicity
7578 added to the option table so that they won't get overshadowed in the
7579 future by other options that begin with the same letter.
7583 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7584 Many assorted bugs have been handled. Many more remain to be handled.
7585 See the various ChangeLog files (primarily in gdb and bfd) for details.
7588 *** Changes in GDB-4.3:
7590 * New machines supported (host and target)
7592 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7593 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7594 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7596 * Almost SCO Unix support
7598 We had hoped to support:
7599 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7600 (except for core file support), but we discovered very late in the release
7601 that it has problems with process groups that render gdb unusable. Sorry
7602 about that. I encourage people to fix it and post the fixes.
7604 * Preliminary ELF and DWARF support
7606 GDB can read ELF object files on System V Release 4, and can handle
7607 debugging records for C, in DWARF format, in ELF files. This support
7608 is preliminary. If you bring up GDB on another SVR4 system, please
7609 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7614 GDB now uses the latest `readline' library. One user-visible change
7615 is that two tabs will list possible command completions, which previously
7616 required typing M-? (meta-question mark, or ESC ?).
7620 The `stepi' bug that many of you noticed has been squashed.
7621 Many bugs in C++ have been handled. Many more remain to be handled.
7622 See the various ChangeLog files (primarily in gdb and bfd) for details.
7624 * State of the MIPS world (in case you wondered):
7626 GDB can understand the symbol tables emitted by the compilers
7627 supplied by most vendors of MIPS-based machines, including DEC. These
7628 symbol tables are in a format that essentially nobody else uses.
7630 Some versions of gcc come with an assembler post-processor called
7631 mips-tfile. This program is required if you want to do source-level
7632 debugging of gcc-compiled programs. I believe FSF does not ship
7633 mips-tfile with gcc version 1, but it will eventually come with gcc
7636 Debugging of g++ output remains a problem. g++ version 1.xx does not
7637 really support it at all. (If you're lucky, you should be able to get
7638 line numbers and stack traces to work, but no parameters or local
7639 variables.) With some work it should be possible to improve the
7642 When gcc version 2 is released, you will have somewhat better luck.
7643 However, even then you will get confusing results for inheritance and
7646 We will eventually provide full debugging of g++ output on
7647 DECstations. This will probably involve some kind of stabs-in-ecoff
7648 encapulation, but the details have not been worked out yet.
7651 *** Changes in GDB-4.2:
7653 * Improved configuration
7655 Only one copy of `configure' exists now, and it is not self-modifying.
7656 Porting BFD is simpler.
7660 The `step' and `next' commands now only stop at the first instruction
7661 of a source line. This prevents the multiple stops that used to occur
7662 in switch statements, for-loops, etc. `Step' continues to stop if a
7663 function that has debugging information is called within the line.
7667 Lots of small bugs fixed. More remain.
7669 * New host supported (not target)
7671 Intel 386 PC clone running Mach i386-none-mach
7674 *** Changes in GDB-4.1:
7676 * Multiple source language support
7678 GDB now has internal scaffolding to handle several source languages.
7679 It determines the type of each source file from its filename extension,
7680 and will switch expression parsing and number formatting to match the
7681 language of the function in the currently selected stack frame.
7682 You can also specifically set the language to be used, with
7683 `set language c' or `set language modula-2'.
7687 GDB now has preliminary support for the GNU Modula-2 compiler,
7688 currently under development at the State University of New York at
7689 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7690 continue through the fall of 1991 and into 1992.
7692 Other Modula-2 compilers are currently not supported, and attempting to
7693 debug programs compiled with them will likely result in an error as the
7694 symbol table is read. Feel free to work on it, though!
7696 There are hooks in GDB for strict type checking and range checking,
7697 in the `Modula-2 philosophy', but they do not currently work.
7701 GDB can now write to executable and core files (e.g. patch
7702 a variable's value). You must turn this switch on, specify
7703 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7704 by assigning a new value to a variable. Modifications take
7707 * Automatic SunOS shared library reading
7709 When you run your program, GDB automatically determines where its
7710 shared libraries (if any) have been loaded, and reads their symbols.
7711 The `share' command is no longer needed. This also works when
7712 examining core files.
7716 You can specify the number of lines that the `list' command shows.
7719 * New machines supported (host and target)
7721 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7722 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7723 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7725 * New hosts supported (not targets)
7727 IBM RT/PC: romp-ibm-aix or rtpc
7729 * New targets supported (not hosts)
7731 AMD 29000 embedded with COFF a29k-none-coff
7732 AMD 29000 embedded with a.out a29k-none-aout
7733 Ultracomputer remote kernel debug a29k-nyu-kern
7735 * New remote interfaces
7741 *** Changes in GDB-4.0:
7745 Wide output is wrapped at good places to make the output more readable.
7747 Gdb now supports cross-debugging from a host machine of one type to a
7748 target machine of another type. Communication with the target system
7749 is over serial lines. The ``target'' command handles connecting to the
7750 remote system; the ``load'' command will download a program into the
7751 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7752 also supports debugging of realtime processes running under VxWorks,
7753 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7754 stub on the target system.
7756 New CPUs supported include the AMD 29000 and Intel 960.
7758 GDB now reads object files and symbol tables via a ``binary file''
7759 library, which allows a single copy of GDB to debug programs of multiple
7760 object file types such as a.out and coff.
7762 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7763 refcard.dvi and refcard.ps are available to format it).
7766 * Control-Variable user interface simplified
7768 All variables that control the operation of the debugger can be set
7769 by the ``set'' command, and displayed by the ``show'' command.
7771 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7772 ``Show prompt'' produces the response:
7773 Gdb's prompt is new-gdb=>.
7775 What follows are the NEW set commands. The command ``help set'' will
7776 print a complete list of old and new set commands. ``help set FOO''
7777 will give a longer description of the variable FOO. ``show'' will show
7778 all of the variable descriptions and their current settings.
7780 confirm on/off: Enables warning questions for operations that are
7781 hard to recover from, e.g. rerunning the program while
7782 it is already running. Default is ON.
7784 editing on/off: Enables EMACS style command line editing
7785 of input. Previous lines can be recalled with
7786 control-P, the current line can be edited with control-B,
7787 you can search for commands with control-R, etc.
7790 history filename NAME: NAME is where the gdb command history
7791 will be stored. The default is .gdb_history,
7792 or the value of the environment variable
7795 history size N: The size, in commands, of the command history. The
7796 default is 256, or the value of the environment variable
7799 history save on/off: If this value is set to ON, the history file will
7800 be saved after exiting gdb. If set to OFF, the
7801 file will not be saved. The default is OFF.
7803 history expansion on/off: If this value is set to ON, then csh-like
7804 history expansion will be performed on
7805 command line input. The default is OFF.
7807 radix N: Sets the default radix for input and output. It can be set
7808 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7809 in the current radix, so "set radix 10" is always a no-op.
7811 height N: This integer value is the number of lines on a page. Default
7812 is 24, the current `stty rows'' setting, or the ``li#''
7813 setting from the termcap entry matching the environment
7816 width N: This integer value is the number of characters on a line.
7817 Default is 80, the current `stty cols'' setting, or the ``co#''
7818 setting from the termcap entry matching the environment
7821 Note: ``set screensize'' is obsolete. Use ``set height'' and
7822 ``set width'' instead.
7824 print address on/off: Print memory addresses in various command displays,
7825 such as stack traces and structure values. Gdb looks
7826 more ``symbolic'' if you turn this off; it looks more
7827 ``machine level'' with it on. Default is ON.
7829 print array on/off: Prettyprint arrays. New convenient format! Default
7832 print demangle on/off: Print C++ symbols in "source" form if on,
7835 print asm-demangle on/off: Same, for assembler level printouts
7838 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7841 * Support for Epoch Environment.
7843 The epoch environment is a version of Emacs v18 with windowing. One
7844 new command, ``inspect'', is identical to ``print'', except that if you
7845 are running in the epoch environment, the value is printed in its own
7849 * Support for Shared Libraries
7851 GDB can now debug programs and core files that use SunOS shared libraries.
7852 Symbols from a shared library cannot be referenced
7853 before the shared library has been linked with the program (this
7854 happens after you type ``run'' and before the function main() is entered).
7855 At any time after this linking (including when examining core files
7856 from dynamically linked programs), gdb reads the symbols from each
7857 shared library when you type the ``sharedlibrary'' command.
7858 It can be abbreviated ``share''.
7860 sharedlibrary REGEXP: Load shared object library symbols for files
7861 matching a unix regular expression. No argument
7862 indicates to load symbols for all shared libraries.
7864 info sharedlibrary: Status of loaded shared libraries.
7869 A watchpoint stops execution of a program whenever the value of an
7870 expression changes. Checking for this slows down execution
7871 tremendously whenever you are in the scope of the expression, but is
7872 quite useful for catching tough ``bit-spreader'' or pointer misuse
7873 problems. Some machines such as the 386 have hardware for doing this
7874 more quickly, and future versions of gdb will use this hardware.
7876 watch EXP: Set a watchpoint (breakpoint) for an expression.
7878 info watchpoints: Information about your watchpoints.
7880 delete N: Deletes watchpoint number N (same as breakpoints).
7881 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7882 enable N: Re-enables watchpoint number N (same as breakpoints).
7885 * C++ multiple inheritance
7887 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7890 * C++ exception handling
7892 Gdb now supports limited C++ exception handling. Besides the existing
7893 ability to breakpoint on an exception handler, gdb can breakpoint on
7894 the raising of an exception (before the stack is peeled back to the
7897 catch FOO: If there is a FOO exception handler in the dynamic scope,
7898 set a breakpoint to catch exceptions which may be raised there.
7899 Multiple exceptions (``catch foo bar baz'') may be caught.
7901 info catch: Lists all exceptions which may be caught in the
7902 current stack frame.
7905 * Minor command changes
7907 The command ``call func (arg, arg, ...)'' now acts like the print
7908 command, except it does not print or save a value if the function's result
7909 is void. This is similar to dbx usage.
7911 The ``up'' and ``down'' commands now always print the frame they end up
7912 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7913 frames without printing.
7915 * New directory command
7917 'dir' now adds directories to the FRONT of the source search path.
7918 The path starts off empty. Source files that contain debug information
7919 about the directory in which they were compiled can be found even
7920 with an empty path; Sun CC and GCC include this information. If GDB can't
7921 find your source file in the current directory, type "dir .".
7923 * Configuring GDB for compilation
7925 For normal use, type ``./configure host''. See README or gdb.texinfo
7928 GDB now handles cross debugging. If you are remotely debugging between
7929 two different machines, type ``./configure host -target=targ''.
7930 Host is the machine where GDB will run; targ is the machine
7931 where the program that you are debugging will run.