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
84 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
88 ** gdb.register_window_type can be used to implement new TUI windows
91 ** Dynamic types can now be queried. gdb.Type has a new attribute,
92 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
93 field of a dynamic type may have None for its "bitpos" attribute
96 ** Commands written in Python can be in the "TUI" help class by
97 registering with the new constant gdb.COMMAND_TUI.
101 * 'thread-exited' event is now available in the annotations interface.
103 * New built-in convenience variables $_gdb_major and $_gdb_minor
104 provide the GDB version. They are handy for conditionally using
105 features available only in or since specific GDB versions, in
106 scripts that should work error-free with many different versions,
107 such as in system-wide init files.
109 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
110 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
111 of the GDB settings and the GDB maintenance settings. They are handy
112 for changing the logic of user defined commands depending on the
113 current GDB settings.
115 * GDB now supports Thread Local Storage (TLS) variables on several
116 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
117 architectures require kernel changes. TLS is not yet supported for
118 amd64 and i386 process core dumps.
120 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
121 addresses that required unmasking are shown in the backtrace with the
124 * Two new convenience functions $_cimag and $_creal that extract the
125 imaginary and real parts respectively from complex numbers.
127 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
128 provide the exitcode or exit status of the shell commands launched by
129 GDB commands such as "shell", "pipe" and "make".
131 * The command define-prefix can now define user defined prefix commands.
132 User defined commands can now be defined using these user defined prefix
135 * Command names can now use the . character.
137 * The RX port now supports XML target descriptions.
139 * GDB now shows the Ada task names at more places, e.g. in task switching
142 * GDB can now be compiled with Python 3 on Windows.
144 * New convenience variable $_ada_exception holds the address of the
145 Ada exception being thrown. This is set by Ada-related catchpoints.
147 * GDB can now place breakpoints on nested functions and subroutines in
148 Fortran code. The '::' operator can be used between parent and
149 child scopes when placing breakpoints, for example:
151 (gdb) break outer_function::inner_function
153 The 'outer_function::' prefix is only needed if 'inner_function' is
154 not visible in the current scope.
156 * In addition to the system-wide gdbinit file, if configured with
157 --with-system-gdbinit-dir, GDB will now also load files in that directory
158 as system gdbinit files, unless the -nx or -n flag is provided. Files
159 with extensions .gdb, .py and .scm are supported as long as GDB was
160 compiled with support for that language.
162 * GDB now supports multithreaded symbol loading for higher performance.
163 This feature is still in testing, so it is disabled by default. You
164 can turn it on using 'maint set worker-threads unlimited'.
166 * Multi-target debugging support
168 GDB now supports debugging multiple target connections
169 simultaneously. For example, you can now have each inferior
170 connected to different remote servers running in different machines,
171 or have one inferior debugging a local native process, an inferior
172 debugging a core dump, etc.
174 This support is experimental and comes with some limitations -- you
175 can only resume multiple targets simultaneously if all targets
176 support non-stop mode, and all remote stubs or servers must support
177 the same set of remote protocol features exactly. See also "info
178 connections" and "add-inferior -no-connection" below, and "maint set
179 target-non-stop" in the user manual.
183 ** The gdb.Value type has a new method 'format_string' which returns a
184 string representing the value. The formatting is controlled by the
185 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
186 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
187 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
189 ** gdb.Type has a new property 'objfile' which returns the objfile the
192 ** The frame information printed by the python frame filtering code
193 is now consistent with what the 'backtrace' command prints when
194 there are no filters, or when the 'backtrace' '-no-filters' option
197 ** The new function gdb.lookup_static_symbol can be used to look up
198 symbols with static linkage.
200 ** The new function gdb.lookup_static_symbols can be used to look up
201 all static symbols with static linkage.
203 ** gdb.Objfile has new methods 'lookup_global_symbol' and
204 'lookup_static_symbol' to lookup a symbol from this objfile only.
206 ** gdb.Block now supports the dictionary syntax for accessing symbols in
207 this block (e.g. block['local_variable']).
211 | [COMMAND] | SHELL_COMMAND
212 | -d DELIM COMMAND DELIM SHELL_COMMAND
213 pipe [COMMAND] | SHELL_COMMAND
214 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
215 Executes COMMAND and sends its output to SHELL_COMMAND.
216 With no COMMAND, repeat the last executed command
217 and send its output to SHELL_COMMAND.
219 define-prefix COMMAND
220 Define or mark a command as a user-defined prefix command.
222 with SETTING [VALUE] [-- COMMAND]
223 w SETTING [VALUE] [-- COMMAND]
224 Temporarily set SETTING, run COMMAND, and restore SETTING.
225 Usage: with SETTING -- COMMAND
226 With no COMMAND, repeats the last executed command.
227 SETTING is any GDB setting you can change with the "set"
228 subcommands. For example, 'with language c -- print someobj'
229 temporarily switches to the C language in order to print someobj.
230 Settings can be combined: 'w lang c -- w print elements unlimited --
231 usercmd' switches to the C language and runs usercmd with no limit
232 of array elements to print.
234 maint with SETTING [VALUE] [-- COMMAND]
235 Like "with", but works with "maintenance set" settings.
237 set may-call-functions [on|off]
238 show may-call-functions
239 This controls whether GDB will attempt to call functions in
240 the program, such as with expressions in the print command. It
241 defaults to on. Calling functions in the program being debugged
242 can have undesired side effects. It is now possible to forbid
243 such function calls. If function calls are forbidden, GDB will throw
244 an error when a command (such as print expression) calls a function
247 set print finish [on|off]
249 This controls whether the `finish' command will display the value
250 that is returned by the current function. When `off', the value is
251 still entered into the value history, but it is not printed. The
256 Allows deeply nested structures to be simplified when printing by
257 replacing deeply nested parts (beyond the max-depth) with ellipses.
258 The default max-depth is 20, but this can be set to unlimited to get
259 the old behavior back.
261 set print raw-values [on|off]
262 show print raw-values
263 By default, GDB applies the enabled pretty printers when printing a
264 value. This allows to ignore the enabled pretty printers for a series
265 of commands. The default is 'off'.
267 set logging debugredirect [on|off]
268 By default, GDB debug output will go to both the terminal and the logfile.
269 Set if you want debug output to go only to the log file.
271 set style title foreground COLOR
272 set style title background COLOR
273 set style title intensity VALUE
274 Control the styling of titles.
276 set style highlight foreground COLOR
277 set style highlight background COLOR
278 set style highlight intensity VALUE
279 Control the styling of highlightings.
281 maint set worker-threads
282 maint show worker-threads
283 Control the number of worker threads that can be used by GDB. The
284 default is 0. "unlimited" lets GDB choose a number that is
285 reasonable. Currently worker threads are only used when demangling
286 the names of linker symbols.
288 set style tui-border foreground COLOR
289 set style tui-border background COLOR
290 Control the styling of TUI borders.
292 set style tui-active-border foreground COLOR
293 set style tui-active-border background COLOR
294 Control the styling of the active TUI border.
296 maint set test-settings KIND
297 maint show test-settings KIND
298 A set of commands used by the testsuite for exercising the settings
301 maint set tui-resize-message [on|off]
302 maint show tui-resize-message
303 Control whether GDB prints a message each time the terminal is
304 resized when in TUI mode. This is primarily useful for testing the
307 set print frame-info [short-location|location|location-and-address
308 |source-and-location|source-line|auto]
309 show print frame-info
310 This controls what frame information is printed by the commands printing
311 a frame. This setting will e.g. influence the behaviour of 'backtrace',
312 'frame', 'stepi'. The python frame filtering also respect this setting.
313 The 'backtrace' '-frame-info' option can override this global setting.
315 set tui compact-source
316 show tui compact-source
318 Enable the "compact" display mode for the TUI source window. The
319 compact display uses only as much space as is needed for the line
320 numbers in the current file, and only a single space to separate the
321 line numbers from the source.
323 info modules [-q] [REGEXP]
324 Return a list of Fortran modules matching REGEXP, or all modules if
327 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
328 Return a list of functions within all modules, grouped by module.
329 The list of functions can be restricted with the optional regular
330 expressions. MODULE_REGEXP matches against the module name,
331 TYPE_REGEXP matches against the function type signature, and REGEXP
332 matches against the function name.
334 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
335 Return a list of variables within all modules, grouped by module.
336 The list of variables can be restricted with the optional regular
337 expressions. MODULE_REGEXP matches against the module name,
338 TYPE_REGEXP matches against the variable type, and REGEXP matches
339 against the variable name.
341 set debug remote-packet-max-chars
342 show debug remote-packet-max-chars
343 Controls the number of characters to output in a remote packet when using
345 The default is 512 bytes.
348 Lists the target connections currently in use.
353 The "help" command uses the title style to enhance the
354 readibility of its output by styling the classes and
358 Similarly to "help", the "apropos" command also uses the
359 title style for the command names. "apropos" accepts now
360 a flag "-v" (verbose) to show the full documentation
361 of matching commands and to use the highlight style to mark
362 the documentation parts matching REGEXP.
366 The GDB printf and eval commands can now print C-style and Ada-style
367 string convenience variables without calling functions in the program.
368 This allows to do formatted printing of strings without having
369 a running inferior, or when debugging a core dump.
371 info sources [-dirname | -basename] [--] [REGEXP]
372 This command has now optional arguments to only print the files
373 whose names match REGEXP. The arguments -dirname and -basename
374 allow to restrict matching respectively to the dirname and basename
378 The "show style" and its subcommands are now styling
379 a style name in their output using its own style, to help
380 the user visualize the different styles.
382 set print frame-arguments
383 The new value 'presence' indicates to only indicate the presence of
384 arguments using ..., instead of printing argument names and values.
386 set print raw-frame-arguments
387 show print raw-frame-arguments
389 These commands replace the similarly-named "set/show print raw
390 frame-arguments" commands (now with a dash instead of a space). The
391 old commands are now deprecated and may be removed in a future
394 add-inferior [-no-connection]
395 The add-inferior command now supports a "-no-connection" flag that
396 makes the new inferior start with no target connection associated.
397 By default, the new inferior inherits the target connection of the
398 current inferior. See also "info connections".
401 This command's output now includes a new "Connection" column
402 indicating which target connection an inferior is bound to. See
403 "info connections" above.
405 maint test-options require-delimiter
406 maint test-options unknown-is-error
407 maint test-options unknown-is-operand
408 maint show test-options-completion-result
409 Commands used by the testsuite to validate the command options
412 focus, winheight, +, -, >, <
413 These commands are now case-sensitive.
415 * New command options, command completion
417 GDB now has a standard infrastructure to support dash-style command
418 options ('-OPT'). One benefit is that commands that use it can
419 easily support completion of command line arguments. Try "CMD
420 -[TAB]" or "help CMD" to find options supported by a command. Over
421 time, we intend to migrate most commands to this infrastructure. A
422 number of commands got support for new command options in this
425 ** The "print" and "compile print" commands now support a number of
426 options that allow overriding relevant global print settings as
427 set by "set print" subcommands:
431 -array-indexes [on|off]
432 -elements NUMBER|unlimited
437 -repeats NUMBER|unlimited
438 -static-members [on|off]
443 Note that because the "print"/"compile print" commands accept
444 arbitrary expressions which may look like options (including
445 abbreviations), if you specify any command option, then you must
446 use a double dash ("--") to mark the end of argument processing.
448 ** The "backtrace" command now supports a number of options that
449 allow overriding relevant global print settings as set by "set
450 backtrace" and "set print" subcommands:
452 -entry-values no|only|preferred|if-needed|both|compact|default
453 -frame-arguments all|scalars|none
454 -raw-frame-arguments [on|off]
455 -frame-info auto|source-line|location|source-and-location
456 |location-and-address|short-location
460 In addition, the full/no-filters/hide qualifiers are now also
461 exposed as command options too:
467 ** The "frame apply", "tfaas" and "faas" commands similarly now
468 support the following options:
473 ** The new "info sources" options -dirname and -basename options
474 are using the standard '-OPT' infrastructure.
476 All options above can also be abbreviated. The argument of boolean
477 (on/off) options can be 0/1 too, and also the argument is assumed
478 "on" if omitted. This allows writing compact command invocations,
481 (gdb) p -ra -p -o 0 -- *myptr
483 The above is equivalent to:
485 (gdb) print -raw-values -pretty -object off -- *myptr
487 ** The "info types" command now supports the '-q' flag to disable
488 printing of some header information in a similar fashion to "info
489 variables" and "info functions".
491 ** The "info variables", "info functions", and "whereis" commands
492 now take a '-n' flag that excludes non-debug symbols (symbols
493 from the symbol table, not from the debug info such as DWARF)
496 * Completion improvements
498 ** GDB can now complete the options of the "thread apply all" and
499 "taas" commands, and their "-ascending" option can now be
502 ** GDB can now complete the options of the "info threads", "info
503 functions", "info variables", "info locals", and "info args"
506 ** GDB can now complete the options of the "compile file" and
507 "compile code" commands. The "compile file" command now
508 completes on filenames.
510 ** GDB can now complete the backtrace command's
511 "full/no-filters/hide" qualifiers.
513 * In settings, you can now abbreviate "unlimited".
515 E.g., "set print elements u" is now equivalent to "set print
521 This lists all the possible completions for the rest of the line, if it
522 were to be given as a command itself. This is intended for use by MI
523 frontends in cases when separate CLI and MI channels cannot be used.
525 -catch-throw, -catch-rethrow, and -catch-catch
526 These can be used to catch C++ exceptions in a similar fashion to
527 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
529 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
530 These commands are the MI equivalent of the CLI commands 'info
531 functions', 'info types', and 'info variables' respectively.
533 -symbol-info-modules, this is the MI equivalent of the CLI 'info
536 -symbol-info-module-functions and -symbol-info-module-variables.
537 These commands are the MI equivalent of the CLI commands 'info
538 module functions' and 'info module variables'.
542 ** The default version of the MI interpreter is now 3 (-i=mi3).
544 ** The output of information about multi-location breakpoints (which is
545 syntactically incorrect in MI 2) has changed in MI 3. This affects
546 the following commands and events:
550 - =breakpoint-created
551 - =breakpoint-modified
553 The -fix-multi-location-breakpoint-output command can be used to enable
554 this behavior with previous MI versions.
556 ** Backtraces and frames include a new optional field addr_flags which is
557 given after the addr field. On AArch64 this contains PAC if the address
558 has been masked in the frame. On all other targets the field is not
563 The testsuite now creates the files gdb.cmd (containing the arguments
564 used to launch GDB) and gdb.in (containing all the commands sent to
565 GDB) in the output directory for each test script. Multiple invocations
566 are appended with .1, .2, .3 etc.
568 * Building GDB and GDBserver now requires GNU make >= 3.82.
570 Using another implementation of the make program or an earlier version of
571 GNU make to build GDB or GDBserver is not supported.
573 * Building GDB now requires GNU readline >= 7.0.
575 GDB now bundles GNU readline 8.0, but if you choose to use
576 --with-system-readline, only readline >= 7.0 can be used.
578 * The TUI SingleKey keymap is now named "SingleKey". This can be used
579 from .inputrc to bind keys in this keymap. This feature is only
580 available when gdb is built against GNU readline 8.0 or later.
582 * Removed targets and native configurations
584 GDB no longer supports debugging the Cell Broadband Engine. This includes
585 both debugging standalone Cell/B.E. SPU applications and integrated debugging
586 of Cell/B.E. applications that use both the PPU and SPU architectures.
592 * Removed targets and native configurations
594 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
597 *** Changes in GDB 8.3
599 * GDB and GDBserver now support access to additional registers on
600 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
603 * GDB now has experimental support for the compilation and injection of
604 C++ source code into the inferior. This beta release does not include
605 support for several language features, such as templates, constructors,
608 This feature requires GCC 7.1 or higher built with libcp1.so
611 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
612 can be passed using the '[ADDRESS]:PORT' notation, or the regular
613 'ADDRESS:PORT' method.
615 * DWARF index cache: GDB can now automatically save indices of DWARF
616 symbols on disk to speed up further loading of the same binaries.
618 * Ada task switching is now supported on aarch64-elf targets when
619 debugging a program using the Ravenscar Profile. For more information,
620 see the "Tasking Support when using the Ravenscar Profile" section
621 in the GDB user manual.
623 * GDB in batch mode now exits with status 1 if the last command to be
626 * The RISC-V target now supports target descriptions.
628 * System call catchpoints now support system call aliases on FreeBSD.
629 When the ABI of a system call changes in FreeBSD, this is
630 implemented by leaving a compatibility system call using the old ABI
631 at the existing number and allocating a new system call number for
632 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
633 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
634 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
635 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
636 so that a system call catchpoint for the 'kevent' system call will
637 catch invocations of both the 'kevent' and 'freebsd11_kevent'
638 binaries. This ensures that 'kevent' system calls are caught for
639 binaries using either the old or new ABIs.
641 * Terminal styling is now available for the CLI and the TUI. GNU
642 Source Highlight can additionally be used to provide styling of
643 source code snippets. See the "set style" commands, below, for more
646 * Removed support for old demangling styles arm, edg, gnu, hp and
651 set debug compile-cplus-types
652 show debug compile-cplus-types
653 Control the display of debug output about type conversion in the
654 C++ compile feature. Commands have no effect while compiling
659 Control whether debug output about files/functions skipping is
662 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
663 Apply a command to some frames.
664 FLAG arguments allow to control what output to produce and how to handle
665 errors raised when applying COMMAND to a frame.
668 Apply a command to all threads (ignoring errors and empty output).
669 Shortcut for 'thread apply all -s COMMAND'.
672 Apply a command to all frames (ignoring errors and empty output).
673 Shortcut for 'frame apply all -s COMMAND'.
676 Apply a command to all frames of all threads (ignoring errors and empty
678 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
680 maint set dwarf unwinders (on|off)
681 maint show dwarf unwinders
682 Control whether DWARF unwinders can be used.
685 Display a list of open files for a process.
689 Changes to the "frame", "select-frame", and "info frame" CLI commands.
690 These commands all now take a frame specification which
691 is either a frame level, or one of the keywords 'level', 'address',
692 'function', or 'view' followed by a parameter. Selecting a frame by
693 address, or viewing a frame outside the current backtrace now
694 requires the use of a keyword. Selecting a frame by level is
695 unchanged. The MI comment "-stack-select-frame" is unchanged.
697 target remote FILENAME
698 target extended-remote FILENAME
699 If FILENAME is a Unix domain socket, GDB will attempt to connect
700 to this socket instead of opening FILENAME as a character device.
702 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
703 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
704 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
705 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
706 These commands can now print only the searched entities
707 matching the provided regexp(s), giving a condition
708 on the entity names or entity types. The flag -q disables
709 printing headers or informations messages.
715 These commands now determine the syntax for the shown entities
716 according to the language chosen by `set language'. In particular,
717 `set language auto' means to automatically choose the language of
720 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
721 The 'thread apply' command accepts new FLAG arguments.
722 FLAG arguments allow to control what output to produce and how to handle
723 errors raised when applying COMMAND to a thread.
725 set tui tab-width NCHARS
726 show tui tab-width NCHARS
727 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
729 set style enabled [on|off]
731 Enable or disable terminal styling. Styling is enabled by default
732 on most hosts, but disabled by default when in batch mode.
734 set style sources [on|off]
736 Enable or disable source code styling. Source code styling is
737 enabled by default, but only takes effect if styling in general is
738 enabled, and if GDB was linked with GNU Source Highlight.
740 set style filename foreground COLOR
741 set style filename background COLOR
742 set style filename intensity VALUE
743 Control the styling of file names.
745 set style function foreground COLOR
746 set style function background COLOR
747 set style function intensity VALUE
748 Control the styling of function names.
750 set style variable foreground COLOR
751 set style variable background COLOR
752 set style variable intensity VALUE
753 Control the styling of variable names.
755 set style address foreground COLOR
756 set style address background COLOR
757 set style address intensity VALUE
758 Control the styling of addresses.
762 ** The '-data-disassemble' MI command now accepts an '-a' option to
763 disassemble the whole function surrounding the given program
764 counter value or function name. Support for this feature can be
765 verified by using the "-list-features" command, which should
766 contain "data-disassemble-a-option".
768 ** Command responses and notifications that include a frame now include
769 the frame's architecture in a new "arch" attribute.
771 * New native configurations
773 GNU/Linux/RISC-V riscv*-*-linux*
774 FreeBSD/riscv riscv*-*-freebsd*
778 GNU/Linux/RISC-V riscv*-*-linux*
780 CSKY GNU/LINUX csky*-*-linux
781 FreeBSD/riscv riscv*-*-freebsd*
783 GNU/Linux/OpenRISC or1k*-*-linux*
787 GDB no longer supports native debugging on versions of MS-Windows
792 ** GDB no longer supports Python versions less than 2.6.
794 ** The gdb.Inferior type has a new 'progspace' property, which is the program
795 space associated to that inferior.
797 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
798 of objfiles associated to that program space.
800 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
801 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
804 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
805 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
806 correct and did not work properly.
808 ** The gdb.Value type has a new constructor, which is used to construct a
809 gdb.Value from a Python buffer object and a gdb.Type.
815 Enable or disable the undefined behavior sanitizer. This is
816 disabled by default, but passing --enable-ubsan=yes or
817 --enable-ubsan=auto to configure will enable it. Enabling this can
818 cause a performance penalty. The undefined behavior sanitizer was
819 first introduced in GCC 4.9.
821 *** Changes in GDB 8.2
823 * The 'set disassembler-options' command now supports specifying options
826 * The 'symbol-file' command now accepts an '-o' option to add a relative
827 offset to all sections.
829 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
830 a relative offset to all sections, but it allows to override the load
831 address of individual sections using '-s'.
833 * The 'add-symbol-file' command no longer requires the second argument
834 (address of the text section).
836 * The endianness used with the 'set endian auto' mode in the absence of
837 an executable selected for debugging is now the last endianness chosen
838 either by one of the 'set endian big' and 'set endian little' commands
839 or by inferring from the last executable used, rather than the startup
842 * The pager now allows a "c" response, meaning to disable the pager
843 for the rest of the current command.
845 * The commands 'info variables/functions/types' now show the source line
846 numbers of symbol definitions when available.
848 * 'info proc' now works on running processes on FreeBSD systems and core
849 files created on FreeBSD systems.
851 * C expressions can now use _Alignof, and C++ expressions can now use
854 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
855 the vector length while the process is running.
861 Control display of debugging info regarding the FreeBSD native target.
863 set|show varsize-limit
864 This new setting allows the user to control the maximum size of Ada
865 objects being printed when those objects have a variable type,
866 instead of that maximum size being hardcoded to 65536 bytes.
868 set|show record btrace cpu
869 Controls the processor to be used for enabling errata workarounds for
872 maint check libthread-db
873 Run integrity checks on the current inferior's thread debugging
876 maint set check-libthread-db (on|off)
877 maint show check-libthread-db
878 Control whether to run integrity checks on inferior specific thread
879 debugging libraries as they are loaded. The default is not to
884 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
886 ** The commands attached to a breakpoint can be set by assigning to
887 the breakpoint's "commands" field.
889 ** gdb.execute can now execute multi-line gdb commands.
891 ** The new functions gdb.convenience_variable and
892 gdb.set_convenience_variable can be used to get and set the value
893 of convenience variables.
895 ** A gdb.Parameter will no longer print the "set" help text on an
896 ordinary "set"; instead by default a "set" will be silent unless
897 the get_set_string method returns a non-empty string.
901 RiscV ELF riscv*-*-elf
903 * Removed targets and native configurations
905 m88k running OpenBSD m88*-*-openbsd*
906 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
907 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
908 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
910 * Aarch64/Linux hardware watchpoints improvements
912 Hardware watchpoints on unaligned addresses are now properly
913 supported when running Linux kernel 4.10 or higher: read and access
914 watchpoints are no longer spuriously missed, and all watchpoints
915 lengths between 1 and 8 bytes are supported. On older kernels,
916 watchpoints set on unaligned addresses are no longer missed, with
917 the tradeoff that there is a possibility of false hits being
922 --enable-codesign=CERT
923 This can be used to invoke "codesign -s CERT" after building gdb.
924 This option is useful on macOS, where code signing is required for
925 gdb to work properly.
927 --disable-gdbcli has been removed
928 This is now silently accepted, but does nothing.
930 *** Changes in GDB 8.1
932 * GDB now supports dynamically creating arbitrary register groups specified
933 in XML target descriptions. This allows for finer grain grouping of
934 registers on systems with a large amount of registers.
936 * The 'ptype' command now accepts a '/o' flag, which prints the
937 offsets and sizes of fields in a struct, like the pahole(1) tool.
939 * New "--readnever" command line option instructs GDB to not read each
940 symbol file's symbolic debug information. This makes startup faster
941 but at the expense of not being able to perform symbolic debugging.
942 This option is intended for use cases where symbolic debugging will
943 not be used, e.g., when you only need to dump the debuggee's core.
945 * GDB now uses the GNU MPFR library, if available, to emulate target
946 floating-point arithmetic during expression evaluation when the target
947 uses different floating-point formats than the host. At least version
948 3.1 of GNU MPFR is required.
950 * GDB now supports access to the guarded-storage-control registers and the
951 software-based guarded-storage broadcast control registers on IBM z14.
953 * On Unix systems, GDB now supports transmitting environment variables
954 that are to be set or unset to GDBserver. These variables will
955 affect the environment to be passed to the remote inferior.
957 To inform GDB of environment variables that are to be transmitted to
958 GDBserver, use the "set environment" command. Only user set
959 environment variables are sent to GDBserver.
961 To inform GDB of environment variables that are to be unset before
962 the remote inferior is started by the GDBserver, use the "unset
963 environment" command.
965 * Completion improvements
967 ** GDB can now complete function parameters in linespecs and
968 explicit locations without quoting. When setting breakpoints,
969 quoting around functions names to help with TAB-completion is
970 generally no longer necessary. For example, this now completes
973 (gdb) b function(in[TAB]
974 (gdb) b function(int)
976 Related, GDB is no longer confused with completing functions in
977 C++ anonymous namespaces:
980 (gdb) b (anonymous namespace)::[TAB][TAB]
981 (anonymous namespace)::a_function()
982 (anonymous namespace)::b_function()
984 ** GDB now has much improved linespec and explicit locations TAB
985 completion support, that better understands what you're
986 completing and offers better suggestions. For example, GDB no
987 longer offers data symbols as possible completions when you're
988 setting a breakpoint.
990 ** GDB now TAB-completes label symbol names.
992 ** The "complete" command now mimics TAB completion accurately.
994 * New command line options (gcore)
997 Dump all memory mappings.
999 * Breakpoints on C++ functions are now set on all scopes by default
1001 By default, breakpoints on functions/methods are now interpreted as
1002 specifying all functions with the given name ignoring missing
1003 leading scopes (namespaces and classes).
1005 For example, assuming a C++ program with symbols named:
1010 both commands "break func()" and "break B::func()" set a breakpoint
1013 You can use the new flag "-qualified" to override this. This makes
1014 GDB interpret the specified function name as a complete
1015 fully-qualified name instead. For example, using the same C++
1016 program, the "break -q B::func" command sets a breakpoint on
1017 "B::func", only. A parameter has been added to the Python
1018 gdb.Breakpoint constructor to achieve the same result when creating
1019 a breakpoint from Python.
1021 * Breakpoints on functions marked with C++ ABI tags
1023 GDB can now set breakpoints on functions marked with C++ ABI tags
1024 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1025 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1027 Functions with a C++11 abi tag are demangled/displayed like this:
1029 function[abi:cxx11](int)
1032 You can now set a breakpoint on such functions simply as if they had
1035 (gdb) b function(int)
1037 Or if you need to disambiguate between tags, like:
1039 (gdb) b function[abi:other_tag](int)
1041 Tab completion was adjusted accordingly as well.
1045 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1046 gdb.new_thread are emitted. See the manual for further
1047 description of these.
1049 ** A new function, "gdb.rbreak" has been added to the Python API.
1050 This function allows the setting of a large number of breakpoints
1051 via a regex pattern in Python. See the manual for further details.
1053 ** Python breakpoints can now accept explicit locations. See the
1054 manual for a further description of this feature.
1057 * New features in the GDB remote stub, GDBserver
1059 ** GDBserver is now able to start inferior processes with a
1060 specified initial working directory.
1062 The user can set the desired working directory to be used from
1063 GDB using the new "set cwd" command.
1065 ** New "--selftest" command line option runs some GDBserver self
1066 tests. These self tests are disabled in releases.
1068 ** On Unix systems, GDBserver now does globbing expansion and variable
1069 substitution in inferior command line arguments.
1071 This is done by starting inferiors using a shell, like GDB does.
1072 See "set startup-with-shell" in the user manual for how to disable
1073 this from GDB when using "target extended-remote". When using
1074 "target remote", you can disable the startup with shell by using the
1075 new "--no-startup-with-shell" GDBserver command line option.
1077 ** On Unix systems, GDBserver now supports receiving environment
1078 variables that are to be set or unset from GDB. These variables
1079 will affect the environment to be passed to the inferior.
1081 * When catching an Ada exception raised with a message, GDB now prints
1082 the message in the catchpoint hit notification. In GDB/MI mode, that
1083 information is provided as an extra field named "exception-message"
1084 in the *stopped notification.
1086 * Trait objects can now be inspected When debugging Rust code. This
1087 requires compiler support which will appear in Rust 1.24.
1089 * New remote packets
1091 QEnvironmentHexEncoded
1092 Inform GDBserver of an environment variable that is to be passed to
1093 the inferior when starting it.
1096 Inform GDBserver of an environment variable that is to be unset
1097 before starting the remote inferior.
1100 Inform GDBserver that the environment should be reset (i.e.,
1101 user-set environment variables should be unset).
1104 Indicates whether the inferior must be started with a shell or not.
1107 Tell GDBserver that the inferior to be started should use a specific
1110 * The "maintenance print c-tdesc" command now takes an optional
1111 argument which is the file name of XML target description.
1113 * The "maintenance selftest" command now takes an optional argument to
1114 filter the tests to be run.
1116 * The "enable", and "disable" commands now accept a range of
1117 breakpoint locations, e.g. "enable 1.3-5".
1122 Set and show the current working directory for the inferior.
1124 set|show compile-gcc
1125 Set and show compilation command used for compiling and injecting code
1126 with the 'compile' commands.
1128 set debug separate-debug-file
1129 show debug separate-debug-file
1130 Control the display of debug output about separate debug file search.
1132 set dump-excluded-mappings
1133 show dump-excluded-mappings
1134 Control whether mappings marked with the VM_DONTDUMP flag should be
1135 dumped when generating a core file.
1137 maint info selftests
1138 List the registered selftests.
1141 Start the debugged program stopping at the first instruction.
1144 Control display of debugging messages related to OpenRISC targets.
1146 set|show print type nested-type-limit
1147 Set and show the limit of nesting level for nested types that the
1148 type printer will show.
1150 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1153 * Safer/improved support for debugging with no debug info
1155 GDB no longer assumes functions with no debug information return
1158 This means that GDB now refuses to call such functions unless you
1159 tell it the function's type, by either casting the call to the
1160 declared return type, or by casting the function to a function
1161 pointer of the right type, and calling that:
1163 (gdb) p getenv ("PATH")
1164 'getenv' has unknown return type; cast the call to its declared return type
1165 (gdb) p (char *) getenv ("PATH")
1166 $1 = 0x7fffffffe "/usr/local/bin:/"...
1167 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1168 $2 = 0x7fffffffe "/usr/local/bin:/"...
1170 Similarly, GDB no longer assumes that global variables with no debug
1171 info have type 'int', and refuses to print the variable's value
1172 unless you tell it the variable's type:
1175 'var' has unknown type; cast it to its declared type
1179 * New native configurations
1181 FreeBSD/aarch64 aarch64*-*-freebsd*
1182 FreeBSD/arm arm*-*-freebsd*
1186 FreeBSD/aarch64 aarch64*-*-freebsd*
1187 FreeBSD/arm arm*-*-freebsd*
1188 OpenRISC ELF or1k*-*-elf
1190 * Removed targets and native configurations
1192 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1194 *** Changes in GDB 8.0
1196 * GDB now supports access to the PKU register on GNU/Linux. The register is
1197 added by the Memory Protection Keys for Userspace feature which will be
1198 available in future Intel CPUs.
1200 * GDB now supports C++11 rvalue references.
1204 ** New functions to start, stop and access a running btrace recording.
1205 ** Rvalue references are now supported in gdb.Type.
1207 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1210 * Building GDB and GDBserver now requires a C++11 compiler.
1212 For example, GCC 4.8 or later.
1214 It is no longer possible to build GDB or GDBserver with a C
1215 compiler. The --disable-build-with-cxx configure option has been
1218 * Building GDB and GDBserver now requires GNU make >= 3.81.
1220 It is no longer supported to build GDB or GDBserver with another
1221 implementation of the make program or an earlier version of GNU make.
1223 * Native debugging on MS-Windows supports command-line redirection
1225 Command-line arguments used for starting programs on MS-Windows can
1226 now include redirection symbols supported by native Windows shells,
1227 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1228 as "run", "start", and "set args", as well as the corresponding MI
1231 * Support for thread names on MS-Windows.
1233 GDB now catches and handles the special exception that programs
1234 running on MS-Windows use to assign names to threads in the
1237 * Support for Java programs compiled with gcj has been removed.
1239 * User commands now accept an unlimited number of arguments.
1240 Previously, only up to 10 was accepted.
1242 * The "eval" command now expands user-defined command arguments.
1244 This makes it easier to process a variable number of arguments:
1249 eval "print $arg%d", $i
1254 * Target descriptions can now describe registers for sparc32 and sparc64.
1256 * GDB now supports DWARF version 5 (debug information format).
1257 Its .debug_names index is not yet supported.
1259 * New native configurations
1261 FreeBSD/mips mips*-*-freebsd
1265 Synopsys ARC arc*-*-elf32
1266 FreeBSD/mips mips*-*-freebsd
1268 * Removed targets and native configurations
1270 Alpha running FreeBSD alpha*-*-freebsd*
1271 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1276 Erases all the flash memory regions reported by the target.
1278 maint print arc arc-instruction address
1279 Print internal disassembler information about instruction at a given address.
1283 set disassembler-options
1284 show disassembler-options
1285 Controls the passing of target specific information to the disassembler.
1286 If it is necessary to specify more than one disassembler option then
1287 multiple options can be placed together into a comma separated list.
1288 The default value is the empty string. Currently, the only supported
1289 targets are ARM, PowerPC and S/390.
1294 Erases all the flash memory regions reported by the target. This is
1295 equivalent to the CLI command flash-erase.
1297 -file-list-shared-libraries
1298 List the shared libraries in the program. This is
1299 equivalent to the CLI command "info shared".
1302 Catchpoints stopping the program when Ada exceptions are
1303 handled. This is equivalent to the CLI command "catch handlers".
1305 *** Changes in GDB 7.12
1307 * GDB and GDBserver now build with a C++ compiler by default.
1309 The --enable-build-with-cxx configure option is now enabled by
1310 default. One must now explicitly configure with
1311 --disable-build-with-cxx in order to build with a C compiler. This
1312 option will be removed in a future release.
1314 * GDBserver now supports recording btrace without maintaining an active
1317 * GDB now supports a negative repeat count in the 'x' command to examine
1318 memory backward from the given address. For example:
1321 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1322 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1323 (gdb) x/-5i 0x0000000000400580
1324 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1325 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1326 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1327 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1328 0x40057b <main(int, char**)+25>:
1329 callq 0x400536 <Func1(int, char const*)>
1331 * Fortran: Support structures with fields of dynamic types and
1332 arrays of dynamic types.
1334 * The symbol dumping maintenance commands have new syntax.
1335 maint print symbols [-pc address] [--] [filename]
1336 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1337 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1338 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1339 maint print msymbols [-objfile objfile] [--] [filename]
1341 * GDB now supports multibit bitfields and enums in target register
1344 * New Python-based convenience function $_as_string(val), which returns
1345 the textual representation of a value. This function is especially
1346 useful to obtain the text label of an enum value.
1348 * Intel MPX bound violation handling.
1350 Segmentation faults caused by a Intel MPX boundary violation
1351 now display the kind of violation (upper or lower), the memory
1352 address accessed and the memory bounds, along with the usual
1353 signal received and code location.
1357 Program received signal SIGSEGV, Segmentation fault
1358 Upper bound violation while accessing address 0x7fffffffc3b3
1359 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1360 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1362 * Rust language support.
1363 GDB now supports debugging programs written in the Rust programming
1364 language. See https://www.rust-lang.org/ for more information about
1367 * Support for running interpreters on specified input/output devices
1369 GDB now supports a new mechanism that allows frontends to provide
1370 fully featured GDB console views, as a better alternative to
1371 building such views on top of the "-interpreter-exec console"
1372 command. See the new "new-ui" command below. With that command,
1373 frontends can now start GDB in the traditional command-line mode
1374 running in an embedded terminal emulator widget, and create a
1375 separate MI interpreter running on a specified i/o device. In this
1376 way, GDB handles line editing, history, tab completion, etc. in the
1377 console all by itself, and the GUI uses the separate MI interpreter
1378 for its own control and synchronization, invisible to the command
1381 * The "catch syscall" command catches groups of related syscalls.
1383 The "catch syscall" command now supports catching a group of related
1384 syscalls using the 'group:' or 'g:' prefix.
1389 skip -gfile file-glob-pattern
1390 skip -function function
1391 skip -rfunction regular-expression
1392 A generalized form of the skip command, with new support for
1393 glob-style file names and regular expressions for function names.
1394 Additionally, a file spec and a function spec may now be combined.
1396 maint info line-table REGEXP
1397 Display the contents of GDB's internal line table data structure.
1400 Run any GDB unit tests that were compiled in.
1403 Start a new user interface instance running INTERP as interpreter,
1404 using the TTY file for input/output.
1408 ** gdb.Breakpoint objects have a new attribute "pending", which
1409 indicates whether the breakpoint is pending.
1410 ** Three new breakpoint-related events have been added:
1411 gdb.breakpoint_created, gdb.breakpoint_modified, and
1412 gdb.breakpoint_deleted.
1414 signal-event EVENTID
1415 Signal ("set") the given MS-Windows event object. This is used in
1416 conjunction with the Windows JIT debugging (AeDebug) support, where
1417 the OS suspends a crashing process until a debugger can attach to
1418 it. Resuming the crashing process, in order to debug it, is done by
1419 signalling an event.
1421 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1422 was added in GDBserver, including JIT compiling fast tracepoint's
1423 conditional expression bytecode into native code.
1425 * Support for various remote target protocols and ROM monitors has
1428 target m32rsdi Remote M32R debugging over SDI
1429 target mips MIPS remote debugging protocol
1430 target pmon PMON ROM monitor
1431 target ddb NEC's DDB variant of PMON for Vr4300
1432 target rockhopper NEC RockHopper variant of PMON
1433 target lsi LSI variant of PMO
1435 * Support for tracepoints and fast tracepoints on powerpc-linux,
1436 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1437 including JIT compiling fast tracepoint's conditional expression
1438 bytecode into native code.
1440 * MI async record =record-started now includes the method and format used for
1441 recording. For example:
1443 =record-started,thread-group="i1",method="btrace",format="bts"
1445 * MI async record =thread-selected now includes the frame field. For example:
1447 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1451 Andes NDS32 nds32*-*-elf
1453 *** Changes in GDB 7.11
1455 * GDB now supports debugging kernel-based threads on FreeBSD.
1457 * Per-inferior thread numbers
1459 Thread numbers are now per inferior instead of global. If you're
1460 debugging multiple inferiors, GDB displays thread IDs using a
1461 qualified INF_NUM.THR_NUM form. For example:
1465 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1466 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1467 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1468 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1470 As consequence, thread numbers as visible in the $_thread
1471 convenience variable and in Python's InferiorThread.num attribute
1472 are no longer unique between inferiors.
1474 GDB now maintains a second thread ID per thread, referred to as the
1475 global thread ID, which is the new equivalent of thread numbers in
1476 previous releases. See also $_gthread below.
1478 For backwards compatibility, MI's thread IDs always refer to global
1481 * Commands that accept thread IDs now accept the qualified
1482 INF_NUM.THR_NUM form as well. For example:
1485 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1488 * In commands that accept a list of thread IDs, you can now refer to
1489 all threads of an inferior using a star wildcard. GDB accepts
1490 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1491 refer to all threads of the current inferior. For example, "info
1494 * You can use "info threads -gid" to display the global thread ID of
1497 * The new convenience variable $_gthread holds the global number of
1500 * The new convenience variable $_inferior holds the number of the
1503 * GDB now displays the ID and name of the thread that hit a breakpoint
1504 or received a signal, if your program is multi-threaded. For
1507 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1508 Thread 1 "main" received signal SIGINT, Interrupt.
1510 * Record btrace now supports non-stop mode.
1512 * Support for tracepoints on aarch64-linux was added in GDBserver.
1514 * The 'record instruction-history' command now indicates speculative execution
1515 when using the Intel Processor Trace recording format.
1517 * GDB now allows users to specify explicit locations, bypassing
1518 the linespec parser. This feature is also available to GDB/MI
1521 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1522 GDB now is able to debug both AArch64 applications and ARM applications
1525 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1526 including JIT compiling fast tracepoint's conditional expression bytecode
1529 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1531 * "info threads", "info inferiors", "info display", "info checkpoints"
1532 and "maint info program-spaces" now list the corresponding items in
1533 ascending ID order, for consistency with all other "info" commands.
1535 * In Ada, the overloads selection menu has been enhanced to display the
1536 parameter types and the return types for the matching overloaded subprograms.
1540 maint set target-non-stop (on|off|auto)
1541 maint show target-non-stop
1542 Control whether GDB targets always operate in non-stop mode even if
1543 "set non-stop" is "off". The default is "auto", meaning non-stop
1544 mode is enabled if supported by the target.
1546 maint set bfd-sharing
1547 maint show bfd-sharing
1548 Control the reuse of bfd objects.
1551 show debug bfd-cache
1552 Control display of debugging info regarding bfd caching.
1556 Control display of debugging info regarding FreeBSD threads.
1558 set remote multiprocess-extensions-packet
1559 show remote multiprocess-extensions-packet
1560 Set/show the use of the remote protocol multiprocess extensions.
1562 set remote thread-events
1563 show remote thread-events
1564 Set/show the use of thread create/exit events.
1566 set ada print-signatures on|off
1567 show ada print-signatures"
1568 Control whether parameter types and return types are displayed in overloads
1569 selection menus. It is activated (@code{on}) by default.
1573 Controls the maximum size of memory, in bytes, that GDB will
1574 allocate for value contents. Prevents incorrect programs from
1575 causing GDB to allocate overly large buffers. Default is 64k.
1577 * The "disassemble" command accepts a new modifier: /s.
1578 It prints mixed source+disassembly like /m with two differences:
1579 - disassembled instructions are now printed in program order, and
1580 - and source for all relevant files is now printed.
1581 The "/m" option is now considered deprecated: its "source-centric"
1582 output hasn't proved useful in practice.
1584 * The "record instruction-history" command accepts a new modifier: /s.
1585 It behaves exactly like /m and prints mixed source+disassembly.
1587 * The "set scheduler-locking" command supports a new mode "replay".
1588 It behaves like "off" in record mode and like "on" in replay mode.
1590 * Support for various ROM monitors has been removed:
1592 target dbug dBUG ROM monitor for Motorola ColdFire
1593 target picobug Motorola picobug monitor
1594 target dink32 DINK32 ROM monitor for PowerPC
1595 target m32r Renesas M32R/D ROM monitor
1596 target mon2000 mon2000 ROM monitor
1597 target ppcbug PPCBUG ROM monitor for PowerPC
1599 * Support for reading/writing memory and extracting values on architectures
1600 whose memory is addressable in units of any integral multiple of 8 bits.
1603 Allows to break when an Ada exception is handled.
1605 * New remote packets
1608 Indicates that an exec system call was executed.
1610 exec-events feature in qSupported
1611 The qSupported packet allows GDB to request support for exec
1612 events using the new 'gdbfeature' exec-event, and the qSupported
1613 response can contain the corresponding 'stubfeature'. Set and
1614 show commands can be used to display whether these features are enabled.
1617 Equivalent to interrupting with the ^C character, but works in
1620 thread created stop reason (T05 create:...)
1621 Indicates that the thread was just created and is stopped at entry.
1623 thread exit stop reply (w exitcode;tid)
1624 Indicates that the thread has terminated.
1627 Enables/disables thread create and exit event reporting. For
1628 example, this is used in non-stop mode when GDB stops a set of
1629 threads and synchronously waits for the their corresponding stop
1630 replies. Without exit events, if one of the threads exits, GDB
1631 would hang forever not knowing that it should no longer expect a
1632 stop for that same thread.
1635 Indicates that there are no resumed threads left in the target (all
1636 threads are stopped). The remote stub reports support for this stop
1637 reply to GDB's qSupported query.
1640 Enables/disables catching syscalls from the inferior process.
1641 The remote stub reports support for this packet to GDB's qSupported query.
1643 syscall_entry stop reason
1644 Indicates that a syscall was just called.
1646 syscall_return stop reason
1647 Indicates that a syscall just returned.
1649 * Extended-remote exec events
1651 ** GDB now has support for exec events on extended-remote Linux targets.
1652 For such targets with Linux kernels 2.5.46 and later, this enables
1653 follow-exec-mode and exec catchpoints.
1655 set remote exec-event-feature-packet
1656 show remote exec-event-feature-packet
1657 Set/show the use of the remote exec event feature.
1659 * Thread names in remote protocol
1661 The reply to qXfer:threads:read may now include a name attribute for each
1664 * Target remote mode fork and exec events
1666 ** GDB now has support for fork and exec events on target remote mode
1667 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1668 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1669 fork and exec catchpoints.
1671 * Remote syscall events
1673 ** GDB now has support for catch syscall on remote Linux targets,
1674 currently enabled on x86/x86_64 architectures.
1676 set remote catch-syscall-packet
1677 show remote catch-syscall-packet
1678 Set/show the use of the remote catch syscall feature.
1682 ** The -var-set-format command now accepts the zero-hexadecimal
1683 format. It outputs data in hexadecimal format with zero-padding on the
1688 ** gdb.InferiorThread objects have a new attribute "global_num",
1689 which refers to the thread's global thread ID. The existing
1690 "num" attribute now refers to the thread's per-inferior number.
1691 See "Per-inferior thread numbers" above.
1692 ** gdb.InferiorThread objects have a new attribute "inferior", which
1693 is the Inferior object the thread belongs to.
1695 *** Changes in GDB 7.10
1697 * Support for process record-replay and reverse debugging on aarch64*-linux*
1698 targets has been added. GDB now supports recording of A64 instruction set
1699 including advance SIMD instructions.
1701 * Support for Sun's version of the "stabs" debug file format has been removed.
1703 * GDB now honors the content of the file /proc/PID/coredump_filter
1704 (PID is the process ID) on GNU/Linux systems. This file can be used
1705 to specify the types of memory mappings that will be included in a
1706 corefile. For more information, please refer to the manual page of
1707 "core(5)". GDB also has a new command: "set use-coredump-filter
1708 on|off". It allows to set whether GDB will read the content of the
1709 /proc/PID/coredump_filter file when generating a corefile.
1711 * The "info os" command on GNU/Linux can now display information on
1713 "info os cpus" Listing of all cpus/cores on the system
1715 * GDB has two new commands: "set serial parity odd|even|none" and
1716 "show serial parity". These allows to set or show parity for the
1719 * The "info source" command now displays the producer string if it was
1720 present in the debug info. This typically includes the compiler version
1721 and may include things like its command line arguments.
1723 * The "info dll", an alias of the "info sharedlibrary" command,
1724 is now available on all platforms.
1726 * Directory names supplied to the "set sysroot" commands may be
1727 prefixed with "target:" to tell GDB to access shared libraries from
1728 the target system, be it local or remote. This replaces the prefix
1729 "remote:". The default sysroot has been changed from "" to
1730 "target:". "remote:" is automatically converted to "target:" for
1731 backward compatibility.
1733 * The system root specified by "set sysroot" will be prepended to the
1734 filename of the main executable (if reported to GDB as absolute by
1735 the operating system) when starting processes remotely, and when
1736 attaching to already-running local or remote processes.
1738 * GDB now supports automatic location and retrieval of executable
1739 files from remote targets. Remote debugging can now be initiated
1740 using only a "target remote" or "target extended-remote" command
1741 (no "set sysroot" or "file" commands are required). See "New remote
1744 * The "dump" command now supports verilog hex format.
1746 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1748 * On GNU/Linux, GDB and gdbserver are now able to access executable
1749 and shared library files without a "set sysroot" command when
1750 attaching to processes running in different mount namespaces from
1751 the debugger. This makes it possible to attach to processes in
1752 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1753 See "New remote packets" below.
1755 * The "tui reg" command now provides completion for all of the
1756 available register groups, including target specific groups.
1758 * The HISTSIZE environment variable is no longer read when determining
1759 the size of GDB's command history. GDB now instead reads the dedicated
1760 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1761 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1766 ** Memory ports can now be unbuffered.
1770 ** gdb.Objfile objects have a new attribute "username",
1771 which is the name of the objfile as specified by the user,
1772 without, for example, resolving symlinks.
1773 ** You can now write frame unwinders in Python.
1774 ** gdb.Type objects have a new method "optimized_out",
1775 returning optimized out gdb.Value instance of this type.
1776 ** gdb.Value objects have new methods "reference_value" and
1777 "const_value" which return a reference to the value and a
1778 "const" version of the value respectively.
1782 maint print symbol-cache
1783 Print the contents of the symbol cache.
1785 maint print symbol-cache-statistics
1786 Print statistics of symbol cache usage.
1788 maint flush-symbol-cache
1789 Flush the contents of the symbol cache.
1793 Start branch trace recording using Branch Trace Store (BTS) format.
1796 Evaluate expression by using the compiler and print result.
1800 Explicit commands for enabling and disabling tui mode.
1803 set mpx bound on i386 and amd64
1804 Support for bound table investigation on Intel MPX enabled applications.
1808 Start branch trace recording using Intel Processor Trace format.
1811 Print information about branch tracing internals.
1813 maint btrace packet-history
1814 Print the raw branch tracing data.
1816 maint btrace clear-packet-history
1817 Discard the stored raw branch tracing data.
1820 Discard all branch tracing data. It will be fetched and processed
1821 anew by the next "record" command.
1826 Renamed from "set debug dwarf2-die".
1827 show debug dwarf-die
1828 Renamed from "show debug dwarf2-die".
1830 set debug dwarf-read
1831 Renamed from "set debug dwarf2-read".
1832 show debug dwarf-read
1833 Renamed from "show debug dwarf2-read".
1835 maint set dwarf always-disassemble
1836 Renamed from "maint set dwarf2 always-disassemble".
1837 maint show dwarf always-disassemble
1838 Renamed from "maint show dwarf2 always-disassemble".
1840 maint set dwarf max-cache-age
1841 Renamed from "maint set dwarf2 max-cache-age".
1842 maint show dwarf max-cache-age
1843 Renamed from "maint show dwarf2 max-cache-age".
1845 set debug dwarf-line
1846 show debug dwarf-line
1847 Control display of debugging info regarding DWARF line processing.
1850 show max-completions
1851 Set the maximum number of candidates to be considered during
1852 completion. The default value is 200. This limit allows GDB
1853 to avoid generating large completion lists, the computation of
1854 which can cause the debugger to become temporarily unresponsive.
1856 set history remove-duplicates
1857 show history remove-duplicates
1858 Control the removal of duplicate history entries.
1860 maint set symbol-cache-size
1861 maint show symbol-cache-size
1862 Control the size of the symbol cache.
1864 set|show record btrace bts buffer-size
1865 Set and show the size of the ring buffer used for branch tracing in
1867 The obtained size may differ from the requested size. Use "info
1868 record" to see the obtained buffer size.
1870 set debug linux-namespaces
1871 show debug linux-namespaces
1872 Control display of debugging info regarding Linux namespaces.
1874 set|show record btrace pt buffer-size
1875 Set and show the size of the ring buffer used for branch tracing in
1876 Intel Processor Trace format.
1877 The obtained size may differ from the requested size. Use "info
1878 record" to see the obtained buffer size.
1880 maint set|show btrace pt skip-pad
1881 Set and show whether PAD packets are skipped when computing the
1884 * The command 'thread apply all' can now support new option '-ascending'
1885 to call its specified command for all threads in ascending order.
1887 * Python/Guile scripting
1889 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1890 special section named `.debug_gdb_scripts'.
1892 * New remote packets
1894 qXfer:btrace-conf:read
1895 Return the branch trace configuration for the current thread.
1897 Qbtrace-conf:bts:size
1898 Set the requested ring buffer size for branch tracing in BTS format.
1901 Enable Intel Processor Trace-based branch tracing for the current
1902 process. The remote stub reports support for this packet to GDB's
1905 Qbtrace-conf:pt:size
1906 Set the requested ring buffer size for branch tracing in Intel Processor
1910 Indicates a memory breakpoint instruction was executed, irrespective
1911 of whether it was GDB that planted the breakpoint or the breakpoint
1912 is hardcoded in the program. This is required for correct non-stop
1916 Indicates the target stopped for a hardware breakpoint. This is
1917 required for correct non-stop mode operation.
1920 Return information about files on the remote system.
1922 qXfer:exec-file:read
1923 Return the full absolute name of the file that was executed to
1924 create a process running on the remote system.
1927 Select the filesystem on which vFile: operations with filename
1928 arguments will operate. This is required for GDB to be able to
1929 access files on remote targets where the remote stub does not
1930 share a common filesystem with the inferior(s).
1933 Indicates that a fork system call was executed.
1936 Indicates that a vfork system call was executed.
1938 vforkdone stop reason
1939 Indicates that a vfork child of the specified process has executed
1940 an exec or exit, allowing the vfork parent to resume execution.
1942 fork-events and vfork-events features in qSupported
1943 The qSupported packet allows GDB to request support for fork and
1944 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1945 and the qSupported response can contain the corresponding
1946 'stubfeatures'. Set and show commands can be used to display
1947 whether these features are enabled.
1949 * Extended-remote fork events
1951 ** GDB now has support for fork events on extended-remote Linux
1952 targets. For targets with Linux kernels 2.5.60 and later, this
1953 enables follow-fork-mode and detach-on-fork for both fork and
1954 vfork, as well as fork and vfork catchpoints.
1956 * The info record command now shows the recording format and the
1957 branch tracing configuration for the current thread when using
1958 the btrace record target.
1959 For the BTS format, it shows the ring buffer size.
1961 * GDB now has support for DTrace USDT (Userland Static Defined
1962 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1964 * GDB now supports access to vector registers on S/390 GNU/Linux
1967 * Removed command line options
1969 -xdb HP-UX XDB compatibility mode.
1971 * Removed targets and native configurations
1973 HP/PA running HP-UX hppa*-*-hpux*
1974 Itanium running HP-UX ia64-*-hpux*
1976 * New configure options
1979 This configure option allows the user to build GDB with support for
1980 Intel Processor Trace (default: auto). This requires libipt.
1982 --with-libipt-prefix=PATH
1983 Specify the path to the version of libipt that GDB should use.
1984 $PATH/include should contain the intel-pt.h header and
1985 $PATH/lib should contain the libipt.so library.
1987 *** Changes in GDB 7.9.1
1991 ** Xmethods can now specify a result type.
1993 *** Changes in GDB 7.9
1995 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1999 ** You can now access frame registers from Python scripts.
2000 ** New attribute 'producer' for gdb.Symtab objects.
2001 ** gdb.Objfile objects have a new attribute "progspace",
2002 which is the gdb.Progspace object of the containing program space.
2003 ** gdb.Objfile objects have a new attribute "owner".
2004 ** gdb.Objfile objects have a new attribute "build_id",
2005 which is the build ID generated when the file was built.
2006 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2007 ** A new event "gdb.clear_objfiles" has been added, triggered when
2008 selecting a new file to debug.
2009 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2010 ** New function gdb.lookup_objfile.
2012 New events which are triggered when GDB modifies the state of the
2015 ** gdb.events.inferior_call_pre: Function call is about to be made.
2016 ** gdb.events.inferior_call_post: Function call has just been made.
2017 ** gdb.events.memory_changed: A memory location has been altered.
2018 ** gdb.events.register_changed: A register has been altered.
2020 * New Python-based convenience functions:
2022 ** $_caller_is(name [, number_of_frames])
2023 ** $_caller_matches(regexp [, number_of_frames])
2024 ** $_any_caller_is(name [, number_of_frames])
2025 ** $_any_caller_matches(regexp [, number_of_frames])
2027 * GDB now supports the compilation and injection of source code into
2028 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2029 to compile the source code to object code, and if successful, inject
2030 and execute that code within the current context of the inferior.
2031 Currently the C language is supported. The commands used to
2032 interface with this new feature are:
2034 compile code [-raw|-r] [--] [source code]
2035 compile file [-raw|-r] filename
2039 demangle [-l language] [--] name
2040 Demangle "name" in the specified language, or the current language
2041 if elided. This command is renamed from the "maint demangle" command.
2042 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2043 as "maint demangler-warning".
2045 queue-signal signal-name-or-number
2046 Queue a signal to be delivered to the thread when it is resumed.
2048 add-auto-load-scripts-directory directory
2049 Add entries to the list of directories from which to load auto-loaded
2052 maint print user-registers
2053 List all currently available "user" registers.
2055 compile code [-r|-raw] [--] [source code]
2056 Compile, inject, and execute in the inferior the executable object
2057 code produced by compiling the provided source code.
2059 compile file [-r|-raw] filename
2060 Compile and inject into the inferior the executable object code
2061 produced by compiling the source code stored in the filename
2064 * On resume, GDB now always passes the signal the program had stopped
2065 for to the thread the signal was sent to, even if the user changed
2066 threads before resuming. Previously GDB would often (but not
2067 always) deliver the signal to the thread that happens to be current
2070 * Conversely, the "signal" command now consistently delivers the
2071 requested signal to the current thread. GDB now asks for
2072 confirmation if the program had stopped for a signal and the user
2073 switched threads meanwhile.
2075 * "breakpoint always-inserted" modes "off" and "auto" merged.
2077 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2078 won't remove breakpoints from the target until all threads stop,
2079 even in non-stop mode. The "auto" mode has been removed, and "off"
2080 is now the default mode.
2084 set debug symbol-lookup
2085 show debug symbol-lookup
2086 Control display of debugging info regarding symbol lookup.
2090 ** The -list-thread-groups command outputs an exit-code field for
2091 inferiors that have exited.
2095 MIPS SDE mips*-sde*-elf*
2099 Support for these obsolete configurations has been removed.
2101 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2102 SGI Irix-5.x mips-*-irix5*
2103 SGI Irix-6.x mips-*-irix6*
2104 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2105 VAX running Ultrix vax-*-ultrix*
2107 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2108 and "assf"), have been removed. Use the "sharedlibrary" command, or
2109 its alias "share", instead.
2111 *** Changes in GDB 7.8
2113 * New command line options
2116 This is an alias for the --data-directory option.
2118 * GDB supports printing and modifying of variable length automatic arrays
2119 as specified in ISO C99.
2121 * The ARM simulator now supports instruction level tracing
2122 with or without disassembly.
2126 GDB now has support for scripting using Guile. Whether this is
2127 available is determined at configure time.
2128 Guile version 2.0 or greater is required.
2129 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2131 * New commands (for set/show, see "New options" below)
2135 Invoke CODE by passing it to the Guile interpreter.
2139 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2141 info auto-load guile-scripts [regexp]
2142 Print the list of automatically loaded Guile scripts.
2144 * The source command is now capable of sourcing Guile scripts.
2145 This feature is dependent on the debugger being built with Guile support.
2149 set print symbol-loading (off|brief|full)
2150 show print symbol-loading
2151 Control whether to print informational messages when loading symbol
2152 information for a file. The default is "full", but when debugging
2153 programs with large numbers of shared libraries the amount of output
2154 becomes less useful.
2156 set guile print-stack (none|message|full)
2157 show guile print-stack
2158 Show a stack trace when an error is encountered in a Guile script.
2160 set auto-load guile-scripts (on|off)
2161 show auto-load guile-scripts
2162 Control auto-loading of Guile script files.
2164 maint ada set ignore-descriptive-types (on|off)
2165 maint ada show ignore-descriptive-types
2166 Control whether the debugger should ignore descriptive types in Ada
2167 programs. The default is not to ignore the descriptive types. See
2168 the user manual for more details on descriptive types and the intended
2169 usage of this option.
2171 set auto-connect-native-target
2173 Control whether GDB is allowed to automatically connect to the
2174 native target for the run, attach, etc. commands when not connected
2175 to any target yet. See also "target native" below.
2177 set record btrace replay-memory-access (read-only|read-write)
2178 show record btrace replay-memory-access
2179 Control what memory accesses are allowed during replay.
2181 maint set target-async (on|off)
2182 maint show target-async
2183 This controls whether GDB targets operate in synchronous or
2184 asynchronous mode. Normally the default is asynchronous, if it is
2185 available; but this can be changed to more easily debug problems
2186 occurring only in synchronous mode.
2188 set mi-async (on|off)
2190 Control whether MI asynchronous mode is preferred. This supersedes
2191 "set target-async" of previous GDB versions.
2193 * "set target-async" is deprecated as a CLI option and is now an alias
2194 for "set mi-async" (only puts MI into async mode).
2196 * Background execution commands (e.g., "c&", "s&", etc.) are now
2197 possible ``out of the box'' if the target supports them. Previously
2198 the user would need to explicitly enable the possibility with the
2199 "set target-async on" command.
2201 * New features in the GDB remote stub, GDBserver
2203 ** New option --debug-format=option1[,option2,...] allows one to add
2204 additional text to each output. At present only timestamps
2205 are supported: --debug-format=timestamps.
2206 Timestamps can also be turned on with the
2207 "monitor set debug-format timestamps" command from GDB.
2209 * The 'record instruction-history' command now starts counting instructions
2210 at one. This also affects the instruction ranges reported by the
2211 'record function-call-history' command when given the /i modifier.
2213 * The command 'record function-call-history' supports a new modifier '/c' to
2214 indent the function names based on their call stack depth.
2215 The fields for the '/i' and '/l' modifier have been reordered.
2216 The source line range is now prefixed with 'at'.
2217 The instruction range is now prefixed with 'inst'.
2218 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2219 "record instruction-history" and "list" commands.
2221 * The ranges given as arguments to the 'record function-call-history' and
2222 'record instruction-history' commands are now inclusive.
2224 * The btrace record target now supports the 'record goto' command.
2225 For locations inside the execution trace, the back trace is computed
2226 based on the information stored in the execution trace.
2228 * The btrace record target supports limited reverse execution and replay.
2229 The target does not record data and therefore does not allow reading
2230 memory or registers.
2232 * The "catch syscall" command now works on s390*-linux* targets.
2234 * The "compare-sections" command is no longer specific to target
2235 remote. It now works with all targets.
2237 * All native targets are now consistently called "native".
2238 Consequently, the "target child", "target GNU", "target djgpp",
2239 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2240 commands have been replaced with "target native". The QNX/NTO port
2241 leaves the "procfs" target in place and adds a "native" target for
2242 consistency with other ports. The impact on users should be minimal
2243 as these commands previously either throwed an error, or were
2244 no-ops. The target's name is visible in the output of the following
2245 commands: "help target", "info target", "info files", "maint print
2248 * The "target native" command now connects to the native target. This
2249 can be used to launch native programs even when "set
2250 auto-connect-native-target" is set to off.
2252 * GDB now supports access to Intel MPX registers on GNU/Linux.
2254 * Support for Intel AVX-512 registers on GNU/Linux.
2255 Support displaying and modifying Intel AVX-512 registers
2256 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2258 * New remote packets
2260 qXfer:btrace:read's annex
2261 The qXfer:btrace:read packet supports a new annex 'delta' to read
2262 branch trace incrementally.
2266 ** Valid Python operations on gdb.Value objects representing
2267 structs/classes invoke the corresponding overloaded operators if
2269 ** New `Xmethods' feature in the Python API. Xmethods are
2270 additional methods or replacements for existing methods of a C++
2271 class. This feature is useful for those cases where a method
2272 defined in C++ source code could be inlined or optimized out by
2273 the compiler, making it unavailable to GDB.
2276 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2278 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2279 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2280 its alias "share", instead.
2282 * The commands "set remotebaud" and "show remotebaud" are no longer
2283 supported. Use "set serial baud" and "show serial baud" (respectively)
2288 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2289 target-async". The latter is left as a deprecated alias of the
2290 former for backward compatibility. If the target supports it,
2291 CLI background execution commands are now always possible by
2292 default, independently of whether the frontend stated a
2293 preference for asynchronous execution with "-gdb-set mi-async".
2294 Previously "-gdb-set target-async off" affected both MI execution
2295 commands and CLI execution commands.
2297 *** Changes in GDB 7.7
2299 * Improved support for process record-replay and reverse debugging on
2300 arm*-linux* targets. Support for thumb32 and syscall instruction
2301 recording has been added.
2303 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2305 * GDB now supports Fission DWP file format version 2.
2306 http://gcc.gnu.org/wiki/DebugFission
2308 * New convenience function "$_isvoid", to check whether an expression
2309 is void. A void expression is an expression where the type of the
2310 result is "void". For example, some convenience variables may be
2311 "void" when evaluated (e.g., "$_exitcode" before the execution of
2312 the program being debugged; or an undefined convenience variable).
2313 Another example, when calling a function whose return type is
2316 * The "maintenance print objfiles" command now takes an optional regexp.
2318 * The "catch syscall" command now works on arm*-linux* targets.
2320 * GDB now consistently shows "<not saved>" when printing values of
2321 registers the debug info indicates have not been saved in the frame
2322 and there's nowhere to retrieve them from
2323 (callee-saved/call-clobbered registers):
2328 (gdb) info registers rax
2331 Before, the former would print "<optimized out>", and the latter
2332 "*value not available*".
2334 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2339 ** Frame filters and frame decorators have been added.
2340 ** Temporary breakpoints are now supported.
2341 ** Line tables representation has been added.
2342 ** New attribute 'parent_type' for gdb.Field objects.
2343 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2344 ** New attribute 'name' for gdb.Type objects.
2348 Nios II ELF nios2*-*-elf
2349 Nios II GNU/Linux nios2*-*-linux
2350 Texas Instruments MSP430 msp430*-*-elf
2352 * Removed native configurations
2354 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2355 been removed. ELF variants of these configurations are kept supported.
2357 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2358 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2359 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2360 i[34567]86-*-openbsd3.[0-3]
2361 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2362 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2363 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2367 Like "catch throw", but catches a re-thrown exception.
2368 maint check-psymtabs
2369 Renamed from old "maint check-symtabs".
2371 Perform consistency checks on symtabs.
2372 maint expand-symtabs
2373 Expand symtabs matching an optional regexp.
2376 Display the details of GDB configure-time options.
2378 maint set|show per-command
2379 maint set|show per-command space
2380 maint set|show per-command time
2381 maint set|show per-command symtab
2382 Enable display of per-command gdb resource usage.
2384 remove-symbol-file FILENAME
2385 remove-symbol-file -a ADDRESS
2386 Remove a symbol file added via add-symbol-file. The file to remove
2387 can be identified by its filename or by an address that lies within
2388 the boundaries of this symbol file in memory.
2391 info exceptions REGEXP
2392 Display the list of Ada exceptions defined in the program being
2393 debugged. If provided, only the exceptions whose names match REGEXP
2398 set debug symfile off|on
2400 Control display of debugging info regarding reading symbol files and
2401 symbol tables within those files
2403 set print raw frame-arguments
2404 show print raw frame-arguments
2405 Set/show whether to print frame arguments in raw mode,
2406 disregarding any defined pretty-printers.
2408 set remote trace-status-packet
2409 show remote trace-status-packet
2410 Set/show the use of remote protocol qTStatus packet.
2414 Control display of debugging messages related to Nios II targets.
2418 Control whether target-assisted range stepping is enabled.
2420 set startup-with-shell
2421 show startup-with-shell
2422 Specifies whether Unix child processes are started via a shell or
2427 Use the target memory cache for accesses to the code segment. This
2428 improves performance of remote debugging (particularly disassembly).
2430 * You can now use a literal value 'unlimited' for options that
2431 interpret 0 or -1 as meaning "unlimited". E.g., "set
2432 trace-buffer-size unlimited" is now an alias for "set
2433 trace-buffer-size -1" and "set height unlimited" is now an alias for
2436 * The "set debug symtab-create" debugging option of GDB has been changed to
2437 accept a verbosity level. 0 means "off", 1 provides basic debugging
2438 output, and values of 2 or greater provides more verbose output.
2440 * New command-line options
2442 Display the details of GDB configure-time options.
2444 * The command 'tsave' can now support new option '-ctf' to save trace
2445 buffer in Common Trace Format.
2447 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2450 * GDB now implements the C++ 'typeid' operator.
2452 * The new convenience variable $_exception holds the exception being
2453 thrown or caught at an exception-related catchpoint.
2455 * The exception-related catchpoints, like "catch throw", now accept a
2456 regular expression which can be used to filter exceptions by type.
2458 * The new convenience variable $_exitsignal is automatically set to
2459 the terminating signal number when the program being debugged dies
2460 due to an uncaught signal.
2464 ** All MI commands now accept an optional "--language" option.
2465 Support for this feature can be verified by using the "-list-features"
2466 command, which should contain "language-option".
2468 ** The new command -info-gdb-mi-command allows the user to determine
2469 whether a GDB/MI command is supported or not.
2471 ** The "^error" result record returned when trying to execute an undefined
2472 GDB/MI command now provides a variable named "code" whose content is the
2473 "undefined-command" error code. Support for this feature can be verified
2474 by using the "-list-features" command, which should contain
2475 "undefined-command-error-code".
2477 ** The -trace-save MI command can optionally save trace buffer in Common
2480 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2482 ** The command -data-list-register-values now accepts an optional
2483 "--skip-unavailable" option. When used, only the available registers
2486 ** The new command -trace-frame-collected dumps collected variables,
2487 computed expressions, tvars, memory and registers in a traceframe.
2489 ** The commands -stack-list-locals, -stack-list-arguments and
2490 -stack-list-variables now accept an option "--skip-unavailable".
2491 When used, only the available locals or arguments are displayed.
2493 ** The -exec-run command now accepts an optional "--start" option.
2494 When used, the command follows the same semantics as the "start"
2495 command, stopping the program's execution at the start of its
2496 main subprogram. Support for this feature can be verified using
2497 the "-list-features" command, which should contain
2498 "exec-run-start-option".
2500 ** The new commands -catch-assert and -catch-exceptions insert
2501 catchpoints stopping the program when Ada exceptions are raised.
2503 ** The new command -info-ada-exceptions provides the equivalent of
2504 the new "info exceptions" command.
2506 * New system-wide configuration scripts
2507 A GDB installation now provides scripts suitable for use as system-wide
2508 configuration scripts for the following systems:
2512 * GDB now supports target-assigned range stepping with remote targets.
2513 This improves the performance of stepping source lines by reducing
2514 the number of control packets from/to GDB. See "New remote packets"
2517 * GDB now understands the element 'tvar' in the XML traceframe info.
2518 It has the id of the collected trace state variables.
2520 * On S/390 targets that provide the transactional-execution feature,
2521 the program interruption transaction diagnostic block (TDB) is now
2522 represented as a number of additional "registers" in GDB.
2524 * New remote packets
2528 The vCont packet supports a new 'r' action, that tells the remote
2529 stub to step through an address range itself, without GDB
2530 involvemement at each single-step.
2532 qXfer:libraries-svr4:read's annex
2533 The previously unused annex of the qXfer:libraries-svr4:read packet
2534 is now used to support passing an argument list. The remote stub
2535 reports support for this argument list to GDB's qSupported query.
2536 The defined arguments are "start" and "prev", used to reduce work
2537 necessary for library list updating, resulting in significant
2540 * New features in the GDB remote stub, GDBserver
2542 ** GDBserver now supports target-assisted range stepping. Currently
2543 enabled on x86/x86_64 GNU/Linux targets.
2545 ** GDBserver now adds element 'tvar' in the XML in the reply to
2546 'qXfer:traceframe-info:read'. It has the id of the collected
2547 trace state variables.
2549 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2552 * New 'z' formatter for printing and examining memory, this displays the
2553 value as hexadecimal zero padded on the left to the size of the type.
2555 * GDB can now use Windows x64 unwinding data.
2557 * The "set remotebaud" command has been replaced by "set serial baud".
2558 Similarly, "show remotebaud" has been replaced by "show serial baud".
2559 The "set remotebaud" and "show remotebaud" commands are still available
2560 to provide backward compatibility with older versions of GDB.
2562 *** Changes in GDB 7.6
2564 * Target record has been renamed to record-full.
2565 Record/replay is now enabled with the "record full" command.
2566 This also affects settings that are associated with full record/replay
2567 that have been moved from "set/show record" to "set/show record full":
2569 set|show record full insn-number-max
2570 set|show record full stop-at-limit
2571 set|show record full memory-query
2573 * A new record target "record-btrace" has been added. The new target
2574 uses hardware support to record the control-flow of a process. It
2575 does not support replaying the execution, but it implements the
2576 below new commands for investigating the recorded execution log.
2577 This new recording method can be enabled using:
2581 The "record-btrace" target is only available on Intel Atom processors
2582 and requires a Linux kernel 2.6.32 or later.
2584 * Two new commands have been added for record/replay to give information
2585 about the recorded execution without having to replay the execution.
2586 The commands are only supported by "record btrace".
2588 record instruction-history prints the execution history at
2589 instruction granularity
2591 record function-call-history prints the execution history at
2592 function granularity
2594 * New native configurations
2596 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2597 FreeBSD/powerpc powerpc*-*-freebsd
2598 x86_64/Cygwin x86_64-*-cygwin*
2599 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2603 ARM AArch64 aarch64*-*-elf
2604 ARM AArch64 GNU/Linux aarch64*-*-linux
2605 Lynx 178 PowerPC powerpc-*-lynx*178
2606 x86_64/Cygwin x86_64-*-cygwin*
2607 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2609 * If the configured location of system.gdbinit file (as given by the
2610 --with-system-gdbinit option at configure time) is in the
2611 data-directory (as specified by --with-gdb-datadir at configure
2612 time) or in one of its subdirectories, then GDB will look for the
2613 system-wide init file in the directory specified by the
2614 --data-directory command-line option.
2616 * New command line options:
2618 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2619 other initialization files, unlike -nx which disables all of them.
2621 * Removed command line options
2623 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2626 * The 'ptype' and 'whatis' commands now accept an argument to control
2629 * 'info proc' now works on some core files.
2633 ** Vectors can be created with gdb.Type.vector.
2635 ** Python's atexit.register now works in GDB.
2637 ** Types can be pretty-printed via a Python API.
2639 ** Python 3 is now supported (in addition to Python 2.4 or later)
2641 ** New class gdb.Architecture exposes GDB's internal representation
2642 of architecture in the Python API.
2644 ** New method Frame.architecture returns the gdb.Architecture object
2645 corresponding to the frame's architecture.
2647 * New Python-based convenience functions:
2649 ** $_memeq(buf1, buf2, length)
2650 ** $_streq(str1, str2)
2652 ** $_regex(str, regex)
2654 * The 'cd' command now defaults to using '~' (the home directory) if not
2657 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2658 default for GCC since November 2000.
2660 * The command 'forward-search' can now be abbreviated as 'fo'.
2662 * The command 'info tracepoints' can now display 'installed on target'
2663 or 'not installed on target' for each non-pending location of tracepoint.
2665 * New configure options
2667 --enable-libmcheck/--disable-libmcheck
2668 By default, development versions are built with -lmcheck on hosts
2669 that support it, in order to help track memory corruption issues.
2670 Release versions, on the other hand, are built without -lmcheck
2671 by default. The --enable-libmcheck/--disable-libmcheck configure
2672 options allow the user to override that default.
2673 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2674 This configure option allows the user to build GDB with
2675 libbabeltrace using which GDB can read Common Trace Format data.
2677 * New commands (for set/show, see "New options" below)
2680 Catch signals. This is similar to "handle", but allows commands and
2681 conditions to be attached.
2684 List the BFDs known to GDB.
2686 python-interactive [command]
2688 Start a Python interactive prompt, or evaluate the optional command
2689 and print the result of expressions.
2692 "py" is a new alias for "python".
2694 enable type-printer [name]...
2695 disable type-printer [name]...
2696 Enable or disable type printers.
2700 ** For the Renesas Super-H architecture, the "regs" command has been removed
2701 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2706 set print type methods (on|off)
2707 show print type methods
2708 Control whether method declarations are displayed by "ptype".
2709 The default is to show them.
2711 set print type typedefs (on|off)
2712 show print type typedefs
2713 Control whether typedef definitions are displayed by "ptype".
2714 The default is to show them.
2716 set filename-display basename|relative|absolute
2717 show filename-display
2718 Control the way in which filenames is displayed.
2719 The default is "relative", which preserves previous behavior.
2721 set trace-buffer-size
2722 show trace-buffer-size
2723 Request target to change the size of trace buffer.
2725 set remote trace-buffer-size-packet auto|on|off
2726 show remote trace-buffer-size-packet
2727 Control the use of the remote protocol `QTBuffer:size' packet.
2731 Control display of debugging messages related to ARM AArch64.
2734 set debug coff-pe-read
2735 show debug coff-pe-read
2736 Control display of debugging messages related to reading of COFF/PE
2741 Control display of debugging messages related to Mach-O symbols
2744 set debug notification
2745 show debug notification
2746 Control display of debugging info for async remote notification.
2750 ** Command parameter changes are now notified using new async record
2751 "=cmd-param-changed".
2752 ** Trace frame changes caused by command "tfind" are now notified using
2753 new async record "=traceframe-changed".
2754 ** The creation, deletion and modification of trace state variables
2755 are now notified using new async records "=tsv-created",
2756 "=tsv-deleted" and "=tsv-modified".
2757 ** The start and stop of process record are now notified using new
2758 async record "=record-started" and "=record-stopped".
2759 ** Memory changes are now notified using new async record
2761 ** The data-disassemble command response will include a "fullname" field
2762 containing the absolute file name when source has been requested.
2763 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2764 command, to allow pattern filling of memory areas.
2765 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2766 library load/unload events.
2767 ** The response to breakpoint commands and breakpoint async records
2768 includes an "installed" field containing a boolean state about each
2769 non-pending tracepoint location is whether installed on target or not.
2770 ** Output of the "-trace-status" command includes a "trace-file" field
2771 containing the name of the trace file being examined. This field is
2772 optional, and only present when examining a trace file.
2773 ** The "fullname" field is now always present along with the "file" field,
2774 even if the file cannot be found by GDB.
2776 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2777 You must have the LZMA library available when configuring GDB for this
2778 feature to be enabled. For more information, see:
2779 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2781 * New remote packets
2784 Set the size of trace buffer. The remote stub reports support for this
2785 packet to gdb's qSupported query.
2788 Enable Branch Trace Store (BTS)-based branch tracing for the current
2789 thread. The remote stub reports support for this packet to gdb's
2793 Disable branch tracing for the current thread. The remote stub reports
2794 support for this packet to gdb's qSupported query.
2797 Read the traced branches for the current thread. The remote stub
2798 reports support for this packet to gdb's qSupported query.
2800 *** Changes in GDB 7.5
2802 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2803 for more x32 ABI info.
2805 * GDB now supports access to MIPS DSP registers on Linux targets.
2807 * GDB now supports debugging microMIPS binaries.
2809 * The "info os" command on GNU/Linux can now display information on
2810 several new classes of objects managed by the operating system:
2811 "info os procgroups" lists process groups
2812 "info os files" lists file descriptors
2813 "info os sockets" lists internet-domain sockets
2814 "info os shm" lists shared-memory regions
2815 "info os semaphores" lists semaphores
2816 "info os msg" lists message queues
2817 "info os modules" lists loaded kernel modules
2819 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2820 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2821 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2822 options and inspect the probe arguments using the new $_probe_arg family
2823 of convenience variables. You can obtain more information about SystemTap
2824 in <http://sourceware.org/systemtap/>.
2826 * GDB now supports reversible debugging on ARM, it allows you to
2827 debug basic ARM and THUMB instructions, and provides
2828 record/replay support.
2830 * The option "symbol-reloading" has been deleted as it is no longer used.
2834 ** GDB commands implemented in Python can now be put in command class
2837 ** The "maint set python print-stack on|off" is now deleted.
2839 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2840 apply "flag enum"-style pretty-printing to any enum.
2842 ** gdb.lookup_symbol can now work when there is no current frame.
2844 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2845 the source at which the symbol was defined.
2847 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2848 method 'value'. The former indicates whether the symbol needs a
2849 frame in order to compute its value, and the latter computes the
2852 ** A new method 'referenced_value' on gdb.Value objects which can
2853 dereference pointer as well as C++ reference values.
2855 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2856 which return the global and static blocks (as gdb.Block objects),
2857 of the underlying symbol table, respectively.
2859 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2860 object associated with a PC value.
2862 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2863 of the address range occupied by code for the current source line.
2865 * Go language support.
2866 GDB now supports debugging programs written in the Go programming
2869 * GDBserver now supports stdio connections.
2870 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2872 * The binary "gdbtui" can no longer be built or installed.
2873 Use "gdb -tui" instead.
2875 * GDB will now print "flag" enums specially. A flag enum is one where
2876 all the enumerator values have no bits in common when pairwise
2877 "and"ed. When printing a value whose type is a flag enum, GDB will
2878 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2879 (gdb) print (enum E) 3
2882 * The filename part of a linespec will now match trailing components
2883 of a source file name. For example, "break gcc/expr.c:1000" will
2884 now set a breakpoint in build/gcc/expr.c, but not
2885 build/libcpp/expr.c.
2887 * The "info proc" and "generate-core-file" commands will now also
2888 work on remote targets connected to GDBserver on Linux.
2890 * The command "info catch" has been removed. It has been disabled
2891 since December 2007.
2893 * The "catch exception" and "catch assert" commands now accept
2894 a condition at the end of the command, much like the "break"
2895 command does. For instance:
2897 (gdb) catch exception Constraint_Error if Barrier = True
2899 Previously, it was possible to add a condition to such catchpoints,
2900 but it had to be done as a second step, after the catchpoint had been
2901 created, using the "condition" command.
2903 * The "info static-tracepoint-marker" command will now also work on
2904 native Linux targets with in-process agent.
2906 * GDB can now set breakpoints on inlined functions.
2908 * The .gdb_index section has been updated to include symbols for
2909 inlined functions. GDB will ignore older .gdb_index sections by
2910 default, which could cause symbol files to be loaded more slowly
2911 until their .gdb_index sections can be recreated. The new command
2912 "set use-deprecated-index-sections on" will cause GDB to use any older
2913 .gdb_index sections it finds. This will restore performance, but the
2914 ability to set breakpoints on inlined functions will be lost in symbol
2915 files with older .gdb_index sections.
2917 The .gdb_index section has also been updated to record more information
2918 about each symbol. This speeds up the "info variables", "info functions"
2919 and "info types" commands when used with programs having the .gdb_index
2920 section, as well as speeding up debugging with shared libraries using
2921 the .gdb_index section.
2923 * Ada support for GDB/MI Variable Objects has been added.
2925 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2930 ** New command -info-os is the MI equivalent of "info os".
2932 ** Output logs ("set logging" and related) now include MI output.
2936 ** "set use-deprecated-index-sections on|off"
2937 "show use-deprecated-index-sections on|off"
2938 Controls the use of deprecated .gdb_index sections.
2940 ** "catch load" and "catch unload" can be used to stop when a shared
2941 library is loaded or unloaded, respectively.
2943 ** "enable count" can be used to auto-disable a breakpoint after
2946 ** "info vtbl" can be used to show the virtual method tables for
2947 C++ and Java objects.
2949 ** "explore" and its sub commands "explore value" and "explore type"
2950 can be used to recursively explore values and types of
2951 expressions. These commands are available only if GDB is
2952 configured with '--with-python'.
2954 ** "info auto-load" shows status of all kinds of auto-loaded files,
2955 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2956 sequences of commands files, "info auto-load python-scripts"
2957 shows status of auto-loading Python script files,
2958 "info auto-load local-gdbinit" shows status of loading init file
2959 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2960 status of inferior specific thread debugging shared library loading.
2962 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2963 and "show auto-load-scripts" commands have been deprecated, use their
2964 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2965 and "show auto-load python-scripts" counterparts instead.
2967 ** "dprintf location,format,args..." creates a dynamic printf, which
2968 is basically a breakpoint that does a printf and immediately
2969 resumes your program's execution, so it is like a printf that you
2970 can insert dynamically at runtime instead of at compiletime.
2972 ** "set print symbol"
2974 Controls whether GDB attempts to display the symbol, if any,
2975 corresponding to addresses it prints. This defaults to "on", but
2976 you can set it to "off" to restore GDB's previous behavior.
2978 * Deprecated commands
2980 ** For the Renesas Super-H architecture, the "regs" command has been
2981 deprecated, and "info all-registers" should be used instead.
2985 Renesas RL78 rl78-*-elf
2986 HP OpenVMS ia64 ia64-hp-openvms*
2988 * GDBserver supports evaluation of breakpoint conditions. When
2989 support is advertised by GDBserver, GDB may be told to send the
2990 breakpoint conditions in bytecode form to GDBserver. GDBserver
2991 will only report the breakpoint trigger to GDB when its condition
2996 set mips compression
2997 show mips compression
2998 Select the compressed ISA encoding used in functions that have no symbol
2999 information available. The encoding can be set to either of:
3002 and is updated automatically from ELF file flags if available.
3004 set breakpoint condition-evaluation
3005 show breakpoint condition-evaluation
3006 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3007 GDBserver ("target"). Default option "auto" chooses the most efficient
3009 This option can improve debugger efficiency depending on the speed of the
3013 Disable auto-loading globally.
3016 Show auto-loading setting of all kinds of auto-loaded files.
3018 set auto-load gdb-scripts on|off
3019 show auto-load gdb-scripts
3020 Control auto-loading of GDB canned sequences of commands files.
3022 set auto-load python-scripts on|off
3023 show auto-load python-scripts
3024 Control auto-loading of Python script files.
3026 set auto-load local-gdbinit on|off
3027 show auto-load local-gdbinit
3028 Control loading of init file (.gdbinit) from current directory.
3030 set auto-load libthread-db on|off
3031 show auto-load libthread-db
3032 Control auto-loading of inferior specific thread debugging shared library.
3034 set auto-load scripts-directory <dir1>[:<dir2>...]
3035 show auto-load scripts-directory
3036 Set a list of directories from which to load auto-loaded scripts.
3037 Automatically loaded Python scripts and GDB scripts are located in one
3038 of the directories listed by this option.
3039 The delimiter (':' above) may differ according to the host platform.
3041 set auto-load safe-path <dir1>[:<dir2>...]
3042 show auto-load safe-path
3043 Set a list of directories from which it is safe to auto-load files.
3044 The delimiter (':' above) may differ according to the host platform.
3046 set debug auto-load on|off
3047 show debug auto-load
3048 Control display of debugging info for auto-loading the files above.
3050 set dprintf-style gdb|call|agent
3052 Control the way in which a dynamic printf is performed; "gdb"
3053 requests a GDB printf command, while "call" causes dprintf to call a
3054 function in the inferior. "agent" requests that the target agent
3055 (such as GDBserver) do the printing.
3057 set dprintf-function <expr>
3058 show dprintf-function
3059 set dprintf-channel <expr>
3060 show dprintf-channel
3061 Set the function and optional first argument to the call when using
3062 the "call" style of dynamic printf.
3064 set disconnected-dprintf on|off
3065 show disconnected-dprintf
3066 Control whether agent-style dynamic printfs continue to be in effect
3067 after GDB disconnects.
3069 * New configure options
3071 --with-auto-load-dir
3072 Configure default value for the 'set auto-load scripts-directory'
3073 setting above. It defaults to '$debugdir:$datadir/auto-load',
3074 $debugdir representing global debugging info directories (available
3075 via 'show debug-file-directory') and $datadir representing GDB's data
3076 directory (available via 'show data-directory').
3078 --with-auto-load-safe-path
3079 Configure default value for the 'set auto-load safe-path' setting
3080 above. It defaults to the --with-auto-load-dir setting.
3082 --without-auto-load-safe-path
3083 Set 'set auto-load safe-path' to '/', effectively disabling this
3086 * New remote packets
3088 z0/z1 conditional breakpoints extension
3090 The z0/z1 breakpoint insertion packets have been extended to carry
3091 a list of conditional expressions over to the remote stub depending on the
3092 condition evaluation mode. The use of this extension can be controlled
3093 via the "set remote conditional-breakpoints-packet" command.
3097 Specify the signals which the remote stub may pass to the debugged
3098 program without GDB involvement.
3100 * New command line options
3102 --init-command=FILE, -ix Like --command, -x but execute it
3103 before loading inferior.
3104 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3105 execute it before loading inferior.
3107 *** Changes in GDB 7.4
3109 * GDB now handles ambiguous linespecs more consistently; the existing
3110 FILE:LINE support has been expanded to other types of linespecs. A
3111 breakpoint will now be set on all matching locations in all
3112 inferiors, and locations will be added or removed according to
3115 * GDB now allows you to skip uninteresting functions and files when
3116 stepping with the "skip function" and "skip file" commands.
3118 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3119 and "show remote hardware-watchpoint-length-limit". These allows to
3120 set or show the maximum length limit (in bytes) of a remote
3121 target hardware watchpoint.
3123 This allows e.g. to use "unlimited" hardware watchpoints with the
3124 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3125 watchpoints are slower than real hardware watchpoints but are
3126 significantly faster than gdb software watchpoints.
3130 ** The register_pretty_printer function in module gdb.printing now takes
3131 an optional `replace' argument. If True, the new printer replaces any
3134 ** The "maint set python print-stack on|off" command has been
3135 deprecated and will be deleted in GDB 7.5.
3136 A new command: "set python print-stack none|full|message" has
3137 replaced it. Additionally, the default for "print-stack" is
3138 now "message", which just prints the error message without
3141 ** A prompt substitution hook (prompt_hook) is now available to the
3144 ** A new Python module, gdb.prompt has been added to the GDB Python
3145 modules library. This module provides functionality for
3146 escape sequences in prompts (used by set/show
3147 extended-prompt). These escape sequences are replaced by their
3148 corresponding value.
3150 ** Python commands and convenience-functions located in
3151 'data-directory'/python/gdb/command and
3152 'data-directory'/python/gdb/function are now automatically loaded
3155 ** Blocks now provide four new attributes. global_block and
3156 static_block will return the global and static blocks
3157 respectively. is_static and is_global are boolean attributes
3158 that indicate if the block is one of those two types.
3160 ** Symbols now provide the "type" attribute, the type of the symbol.
3162 ** The "gdb.breakpoint" function has been deprecated in favor of
3165 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3166 of a function. This class is based on the "finish" command
3167 available in the CLI.
3169 ** Type objects for struct and union types now allow access to
3170 the fields using standard Python dictionary (mapping) methods.
3171 For example, "some_type['myfield']" now works, as does
3172 "some_type.items()".
3174 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3177 ** A new function, "deep_items" has been added to the gdb.types
3178 module in the GDB Python modules library. This function returns
3179 an iterator over the fields of a struct or union type. Unlike
3180 the standard Python "iteritems" method, it will recursively traverse
3181 any anonymous fields.
3185 ** "*stopped" events can report several new "reason"s, such as
3188 ** Breakpoint changes are now notified using new async records, like
3189 "=breakpoint-modified".
3191 ** New command -ada-task-info.
3193 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3194 $sdir specifies the default system locations of shared libraries.
3195 $pdir specifies the directory where the libpthread used by the application
3198 GDB no longer looks in $sdir and $pdir after it has searched the directories
3199 mentioned in libthread-db-search-path. If you want to search those
3200 directories, they must be specified in libthread-db-search-path.
3201 The default value of libthread-db-search-path on GNU/Linux and Solaris
3202 systems is now "$sdir:$pdir".
3204 $pdir is not supported by gdbserver, it is currently ignored.
3205 $sdir is supported by gdbserver.
3207 * New configure option --with-iconv-bin.
3208 When using the internationalization support like the one in the GNU C
3209 library, GDB will invoke the "iconv" program to get a list of supported
3210 character sets. If this program lives in a non-standard location, one can
3211 use this option to specify where to find it.
3213 * When natively debugging programs on PowerPC BookE processors running
3214 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3215 watchpoints, which specify a mask in addition to an address to watch.
3216 The mask specifies that some bits of an address (the bits which are
3217 reset in the mask) should be ignored when matching the address accessed
3218 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3219 section in the user manual for more details.
3221 * The new option --once causes GDBserver to stop listening for connections once
3222 the first connection is made. The listening port used by GDBserver will
3223 become available after that.
3225 * New commands "info macros" and "alias" have been added.
3227 * New function parameters suffix @entry specifies value of function parameter
3228 at the time the function got called. Entry values are available only since
3234 "!" is now an alias of the "shell" command.
3235 Note that no space is needed between "!" and SHELL COMMAND.
3239 watch EXPRESSION mask MASK_VALUE
3240 The watch command now supports the mask argument which allows creation
3241 of masked watchpoints, if the current architecture supports this feature.
3243 info auto-load-scripts [REGEXP]
3244 This command was formerly named "maintenance print section-scripts".
3245 It is now generally useful and is no longer a maintenance-only command.
3247 info macro [-all] [--] MACRO
3248 The info macro command has new options `-all' and `--'. The first for
3249 printing all definitions of a macro. The second for explicitly specifying
3250 the end of arguments and the beginning of the macro name in case the macro
3251 name starts with a hyphen.
3253 collect[/s] EXPRESSIONS
3254 The tracepoint collect command now takes an optional modifier "/s"
3255 that directs it to dereference pointer-to-character types and
3256 collect the bytes of memory up to a zero byte. The behavior is
3257 similar to what you see when you use the regular print command on a
3258 string. An optional integer following the "/s" sets a bound on the
3259 number of bytes that will be collected.
3262 The trace start command now interprets any supplied arguments as a
3263 note to be recorded with the trace run, with an effect similar to
3264 setting the variable trace-notes.
3267 The trace stop command now interprets any arguments as a note to be
3268 mentioned along with the tstatus report that the trace was stopped
3269 with a command. The effect is similar to setting the variable
3272 * Tracepoints can now be enabled and disabled at any time after a trace
3273 experiment has been started using the standard "enable" and "disable"
3274 commands. It is now possible to start a trace experiment with no enabled
3275 tracepoints; GDB will display a warning, but will allow the experiment to
3276 begin, assuming that tracepoints will be enabled as needed while the trace
3279 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3280 locations with 4-byte instructions, when they were previously
3281 limited to locations with instructions of 5 bytes or longer.
3285 set debug dwarf2-read
3286 show debug dwarf2-read
3287 Turns on or off display of debugging messages related to reading
3288 DWARF debug info. The default is off.
3290 set debug symtab-create
3291 show debug symtab-create
3292 Turns on or off display of debugging messages related to symbol table
3293 creation. The default is off.
3296 show extended-prompt
3297 Set the GDB prompt, and allow escape sequences to be inserted to
3298 display miscellaneous information (see 'help set extended-prompt'
3299 for the list of sequences). This prompt (and any information
3300 accessed through the escape sequences) is updated every time the
3301 prompt is displayed.
3303 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3304 show print entry-values
3305 Set printing of frame argument values at function entry. In some cases
3306 GDB can determine the value of function argument which was passed by the
3307 function caller, even if the value was modified inside the called function.
3309 set debug entry-values
3310 show debug entry-values
3311 Control display of debugging info for determining frame argument values at
3312 function entry and virtual tail call frames.
3314 set basenames-may-differ
3315 show basenames-may-differ
3316 Set whether a source file may have multiple base names.
3317 (A "base name" is the name of a file with the directory part removed.
3318 Example: The base name of "/home/user/hello.c" is "hello.c".)
3319 If set, GDB will canonicalize file names (e.g., expand symlinks)
3320 before comparing them. Canonicalization is an expensive operation,
3321 but it allows the same file be known by more than one base name.
3322 If not set (the default), all source files are assumed to have just
3323 one base name, and gdb will do file name comparisons more efficiently.
3329 Set a user name and notes for the current and any future trace runs.
3330 This is useful for long-running and/or disconnected traces, to
3331 inform others (or yourself) as to who is running the trace, supply
3332 contact information, or otherwise explain what is going on.
3334 set trace-stop-notes
3335 show trace-stop-notes
3336 Set a note attached to the trace run, that is displayed when the
3337 trace has been stopped by a tstop command. This is useful for
3338 instance as an explanation, if you are stopping a trace run that was
3339 started by someone else.
3341 * New remote packets
3345 Dynamically enable a tracepoint in a started trace experiment.
3349 Dynamically disable a tracepoint in a started trace experiment.
3353 Set the user and notes of the trace run.
3357 Query the current status of a tracepoint.
3361 Query the minimum length of instruction at which a fast tracepoint may
3364 * Dcache size (number of lines) and line-size are now runtime-configurable
3365 via "set dcache line" and "set dcache line-size" commands.
3369 Texas Instruments TMS320C6x tic6x-*-*
3373 Renesas RL78 rl78-*-elf
3375 *** Changes in GDB 7.3.1
3377 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3379 *** Changes in GDB 7.3
3381 * GDB has a new command: "thread find [REGEXP]".
3382 It finds the thread id whose name, target id, or thread extra info
3383 matches the given regular expression.
3385 * The "catch syscall" command now works on mips*-linux* targets.
3387 * The -data-disassemble MI command now supports modes 2 and 3 for
3388 dumping the instruction opcodes.
3390 * New command line options
3392 -data-directory DIR Specify DIR as the "data-directory".
3393 This is mostly for testing purposes.
3395 * The "maint set python auto-load on|off" command has been renamed to
3396 "set auto-load-scripts on|off".
3398 * GDB has a new command: "set directories".
3399 It is like the "dir" command except that it replaces the
3400 source path list instead of augmenting it.
3402 * GDB now understands thread names.
3404 On GNU/Linux, "info threads" will display the thread name as set by
3405 prctl or pthread_setname_np.
3407 There is also a new command, "thread name", which can be used to
3408 assign a name internally for GDB to display.
3411 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3412 has been integrated into GDB.
3416 ** The function gdb.Write now accepts an optional keyword 'stream'.
3417 This keyword, when provided, will direct the output to either
3418 stdout, stderr, or GDB's logging output.
3420 ** Parameters can now be be sub-classed in Python, and in particular
3421 you may implement the get_set_doc and get_show_doc functions.
3422 This improves how Parameter set/show documentation is processed
3423 and allows for more dynamic content.
3425 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3426 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3427 have an is_valid method.
3429 ** Breakpoints can now be sub-classed in Python, and in particular
3430 you may implement a 'stop' function that is executed each time
3431 the inferior reaches that breakpoint.
3433 ** New function gdb.lookup_global_symbol looks up a global symbol.
3435 ** GDB values in Python are now callable if the value represents a
3436 function. For example, if 'some_value' represents a function that
3437 takes two integer parameters and returns a value, you can call
3438 that function like so:
3440 result = some_value (10,20)
3442 ** Module gdb.types has been added.
3443 It contains a collection of utilities for working with gdb.Types objects:
3444 get_basic_type, has_field, make_enum_dict.
3446 ** Module gdb.printing has been added.
3447 It contains utilities for writing and registering pretty-printers.
3448 New classes: PrettyPrinter, SubPrettyPrinter,
3449 RegexpCollectionPrettyPrinter.
3450 New function: register_pretty_printer.
3452 ** New commands "info pretty-printers", "enable pretty-printer" and
3453 "disable pretty-printer" have been added.
3455 ** gdb.parameter("directories") is now available.
3457 ** New function gdb.newest_frame returns the newest frame in the
3460 ** The gdb.InferiorThread class has a new "name" attribute. This
3461 holds the thread's name.
3463 ** Python Support for Inferior events.
3464 Python scripts can add observers to be notified of events
3465 occurring in the process being debugged.
3466 The following events are currently supported:
3467 - gdb.events.cont Continue event.
3468 - gdb.events.exited Inferior exited event.
3469 - gdb.events.stop Signal received, and Breakpoint hit events.
3473 ** GDB now puts template parameters in scope when debugging in an
3474 instantiation. For example, if you have:
3476 template<int X> int func (void) { return X; }
3478 then if you step into func<5>, "print X" will show "5". This
3479 feature requires proper debuginfo support from the compiler; it
3480 was added to GCC 4.5.
3482 ** The motion commands "next", "finish", "until", and "advance" now
3483 work better when exceptions are thrown. In particular, GDB will
3484 no longer lose control of the inferior; instead, the GDB will
3485 stop the inferior at the point at which the exception is caught.
3486 This functionality requires a change in the exception handling
3487 code that was introduced in GCC 4.5.
3489 * GDB now follows GCC's rules on accessing volatile objects when
3490 reading or writing target state during expression evaluation.
3491 One notable difference to prior behavior is that "print x = 0"
3492 no longer generates a read of x; the value of the assignment is
3493 now always taken directly from the value being assigned.
3495 * GDB now has some support for using labels in the program's source in
3496 linespecs. For instance, you can use "advance label" to continue
3497 execution to a label.
3499 * GDB now has support for reading and writing a new .gdb_index
3500 section. This section holds a fast index of DWARF debugging
3501 information and can be used to greatly speed up GDB startup and
3502 operation. See the documentation for `save gdb-index' for details.
3504 * The "watch" command now accepts an optional "-location" argument.
3505 When used, this causes GDB to watch the memory referred to by the
3506 expression. Such a watchpoint is never deleted due to it going out
3509 * GDB now supports thread debugging of core dumps on GNU/Linux.
3511 GDB now activates thread debugging using the libthread_db library
3512 when debugging GNU/Linux core dumps, similarly to when debugging
3513 live processes. As a result, when debugging a core dump file, GDB
3514 is now able to display pthread_t ids of threads. For example, "info
3515 threads" shows the same output as when debugging the process when it
3516 was live. In earlier releases, you'd see something like this:
3519 * 1 LWP 6780 main () at main.c:10
3521 While now you see this:
3524 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3526 It is also now possible to inspect TLS variables when debugging core
3529 When debugging a core dump generated on a machine other than the one
3530 used to run GDB, you may need to point GDB at the correct
3531 libthread_db library with the "set libthread-db-search-path"
3532 command. See the user manual for more details on this command.
3534 * When natively debugging programs on PowerPC BookE processors running
3535 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3536 which stop execution of the inferior whenever it executes an instruction
3537 at any address within the specified range. See the "PowerPC Embedded"
3538 section in the user manual for more details.
3540 * New features in the GDB remote stub, GDBserver
3542 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3543 and i686 LynxOS (version 5.x).
3545 ** GDBserver is now supported on Blackfin Linux.
3547 * New native configurations
3549 ia64 HP-UX ia64-*-hpux*
3553 Analog Devices, Inc. Blackfin Processor bfin-*
3555 * Ada task switching is now supported on sparc-elf targets when
3556 debugging a program using the Ravenscar Profile. For more information,
3557 see the "Tasking Support when using the Ravenscar Profile" section
3558 in the GDB user manual.
3560 * Guile support was removed.
3562 * New features in the GNU simulator
3564 ** The --map-info flag lists all known core mappings.
3566 ** CFI flashes may be simulated via the "cfi" device.
3568 *** Changes in GDB 7.2
3570 * Shared library support for remote targets by default
3572 When GDB is configured for a generic, non-OS specific target, like
3573 for example, --target=arm-eabi or one of the many *-*-elf targets,
3574 GDB now queries remote stubs for loaded shared libraries using the
3575 `qXfer:libraries:read' packet. Previously, shared library support
3576 was always disabled for such configurations.
3580 ** Argument Dependent Lookup (ADL)
3582 In C++ ADL lookup directs function search to the namespaces of its
3583 arguments even if the namespace has not been imported.
3593 Here the compiler will search for `foo' in the namespace of 'b'
3594 and find A::foo. GDB now supports this. This construct is commonly
3595 used in the Standard Template Library for operators.
3597 ** Improved User Defined Operator Support
3599 In addition to member operators, GDB now supports lookup of operators
3600 defined in a namespace and imported with a `using' directive, operators
3601 defined in the global scope, operators imported implicitly from an
3602 anonymous namespace, and the ADL operators mentioned in the previous
3604 GDB now also supports proper overload resolution for all the previously
3605 mentioned flavors of operators.
3607 ** static const class members
3609 Printing of static const class members that are initialized in the
3610 class definition has been fixed.
3612 * Windows Thread Information Block access.
3614 On Windows targets, GDB now supports displaying the Windows Thread
3615 Information Block (TIB) structure. This structure is visible either
3616 by using the new command `info w32 thread-information-block' or, by
3617 dereferencing the new convenience variable named `$_tlb', a
3618 thread-specific pointer to the TIB. This feature is also supported
3619 when remote debugging using GDBserver.
3621 * Static tracepoints
3623 Static tracepoints are calls in the user program into a tracing
3624 library. One such library is a port of the LTTng kernel tracer to
3625 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3626 When debugging with GDBserver, GDB now supports combining the GDB
3627 tracepoint machinery with such libraries. For example: the user can
3628 use GDB to probe a static tracepoint marker (a call from the user
3629 program into the tracing library) with the new "strace" command (see
3630 "New commands" below). This creates a "static tracepoint" in the
3631 breakpoint list, that can be manipulated with the same feature set
3632 as fast and regular tracepoints. E.g., collect registers, local and
3633 global variables, collect trace state variables, and define
3634 tracepoint conditions. In addition, the user can collect extra
3635 static tracepoint marker specific data, by collecting the new
3636 $_sdata internal variable. When analyzing the trace buffer, you can
3637 inspect $_sdata like any other variable available to GDB. For more
3638 information, see the "Tracepoints" chapter in GDB user manual. New
3639 remote packets have been defined to support static tracepoints, see
3640 the "New remote packets" section below.
3642 * Better reconstruction of tracepoints after disconnected tracing
3644 GDB will attempt to download the original source form of tracepoint
3645 definitions when starting a trace run, and then will upload these
3646 upon reconnection to the target, resulting in a more accurate
3647 reconstruction of the tracepoints that are in use on the target.
3651 You can now exercise direct control over the ways that GDB can
3652 affect your program. For instance, you can disallow the setting of
3653 breakpoints, so that the program can run continuously (assuming
3654 non-stop mode). In addition, the "observer" variable is available
3655 to switch all of the different controls; in observer mode, GDB
3656 cannot affect the target's behavior at all, which is useful for
3657 tasks like diagnosing live systems in the field.
3659 * The new convenience variable $_thread holds the number of the
3662 * New remote packets
3666 Return the address of the Windows Thread Information Block of a given thread.
3670 In response to several of the tracepoint packets, the target may now
3671 also respond with a number of intermediate `qRelocInsn' request
3672 packets before the final result packet, to have GDB handle
3673 relocating an instruction to execute at a different address. This
3674 is particularly useful for stubs that support fast tracepoints. GDB
3675 reports support for this feature in the qSupported packet.
3679 List static tracepoint markers in the target program.
3683 List static tracepoint markers at a given address in the target
3686 qXfer:statictrace:read
3688 Read the static trace data collected (by a `collect $_sdata'
3689 tracepoint action). The remote stub reports support for this packet
3690 to gdb's qSupported query.
3694 Send the current settings of GDB's permission flags.
3698 Send part of the source (textual) form of a tracepoint definition,
3699 which includes location, conditional, and action list.
3701 * The source command now accepts a -s option to force searching for the
3702 script in the source search path even if the script name specifies
3705 * New features in the GDB remote stub, GDBserver
3707 - GDBserver now support tracepoints (including fast tracepoints, and
3708 static tracepoints). The feature is currently supported by the
3709 i386-linux and amd64-linux builds. See the "Tracepoints support
3710 in gdbserver" section in the manual for more information.
3712 GDBserver JIT compiles the tracepoint's conditional agent
3713 expression bytecode into native code whenever possible for low
3714 overhead dynamic tracepoints conditionals. For such tracepoints,
3715 an expression that examines program state is evaluated when the
3716 tracepoint is reached, in order to determine whether to capture
3717 trace data. If the condition is simple and false, processing the
3718 tracepoint finishes very quickly and no data is gathered.
3720 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3721 for static tracepoints support.
3723 - GDBserver now supports x86_64 Windows 64-bit debugging.
3725 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3726 it understands register description.
3728 * The --batch flag now disables pagination and queries.
3730 * X86 general purpose registers
3732 GDB now supports reading/writing byte, word and double-word x86
3733 general purpose registers directly. This means you can use, say,
3734 $ah or $ax to refer, respectively, to the byte register AH and
3735 16-bit word register AX that are actually portions of the 32-bit
3736 register EAX or 64-bit register RAX.
3738 * The `commands' command now accepts a range of breakpoints to modify.
3739 A plain `commands' following a command that creates multiple
3740 breakpoints affects all the breakpoints set by that command. This
3741 applies to breakpoints set by `rbreak', and also applies when a
3742 single `break' command creates multiple breakpoints (e.g.,
3743 breakpoints on overloaded c++ functions).
3745 * The `rbreak' command now accepts a filename specification as part of
3746 its argument, limiting the functions selected by the regex to those
3747 in the specified file.
3749 * Support for remote debugging Windows and SymbianOS shared libraries
3750 from Unix hosts has been improved. Non Windows GDB builds now can
3751 understand target reported file names that follow MS-DOS based file
3752 system semantics, such as file names that include drive letters and
3753 use the backslash character as directory separator. This makes it
3754 possible to transparently use the "set sysroot" and "set
3755 solib-search-path" on Unix hosts to point as host copies of the
3756 target's shared libraries. See the new command "set
3757 target-file-system-kind" described below, and the "Commands to
3758 specify files" section in the user manual for more information.
3762 eval template, expressions...
3763 Convert the values of one or more expressions under the control
3764 of the string template to a command line, and call it.
3766 set target-file-system-kind unix|dos-based|auto
3767 show target-file-system-kind
3768 Set or show the assumed file system kind for target reported file
3771 save breakpoints <filename>
3772 Save all current breakpoint definitions to a file suitable for use
3773 in a later debugging session. To read the saved breakpoint
3774 definitions, use the `source' command.
3776 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3779 info static-tracepoint-markers
3780 Display information about static tracepoint markers in the target.
3782 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3783 Define a static tracepoint by probing a marker at the given
3784 function, line, address, or marker ID.
3788 Enable and disable observer mode.
3790 set may-write-registers on|off
3791 set may-write-memory on|off
3792 set may-insert-breakpoints on|off
3793 set may-insert-tracepoints on|off
3794 set may-insert-fast-tracepoints on|off
3795 set may-interrupt on|off
3796 Set individual permissions for GDB effects on the target. Note that
3797 some of these settings can have undesirable or surprising
3798 consequences, particularly when changed in the middle of a session.
3799 For instance, disabling the writing of memory can prevent
3800 breakpoints from being inserted, cause single-stepping to fail, or
3801 even crash your program, if you disable after breakpoints have been
3802 inserted. However, GDB should not crash.
3804 set record memory-query on|off
3805 show record memory-query
3806 Control whether to stop the inferior if memory changes caused
3807 by an instruction cannot be recorded.
3812 The disassemble command now supports "start,+length" form of two arguments.
3816 ** GDB now provides a new directory location, called the python directory,
3817 where Python scripts written for GDB can be installed. The location
3818 of that directory is <data-directory>/python, where <data-directory>
3819 is the GDB data directory. For more details, see section `Scripting
3820 GDB using Python' in the manual.
3822 ** The GDB Python API now has access to breakpoints, symbols, symbol
3823 tables, program spaces, inferiors, threads and frame's code blocks.
3824 Additionally, GDB Parameters can now be created from the API, and
3825 manipulated via set/show in the CLI.
3827 ** New functions gdb.target_charset, gdb.target_wide_charset,
3828 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3830 ** New exception gdb.GdbError.
3832 ** Pretty-printers are now also looked up in the current program space.
3834 ** Pretty-printers can now be individually enabled and disabled.
3836 ** GDB now looks for names of Python scripts to auto-load in a
3837 special section named `.debug_gdb_scripts', in addition to looking
3838 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3840 * Tracepoint actions were unified with breakpoint commands. In particular,
3841 there are no longer differences in "info break" output for breakpoints and
3842 tracepoints and the "commands" command can be used for both tracepoints and
3843 regular breakpoints.
3847 ARM Symbian arm*-*-symbianelf*
3849 * D language support.
3850 GDB now supports debugging programs written in the D programming
3853 * GDB now supports the extended ptrace interface for PowerPC which is
3854 available since Linux kernel version 2.6.34. This automatically enables
3855 any hardware breakpoints and additional hardware watchpoints available in
3856 the processor. The old ptrace interface exposes just one hardware
3857 watchpoint and no hardware breakpoints.
3859 * GDB is now able to use the Data Value Compare (DVC) register available on
3860 embedded PowerPC processors to implement in hardware simple watchpoint
3861 conditions of the form:
3863 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3865 This works in native GDB running on Linux kernels with the extended ptrace
3866 interface mentioned above.
3868 *** Changes in GDB 7.1
3872 ** Namespace Support
3874 GDB now supports importing of namespaces in C++. This enables the
3875 user to inspect variables from imported namespaces. Support for
3876 namepace aliasing has also been added. So, if a namespace is
3877 aliased in the current scope (e.g. namepace C=A; ) the user can
3878 print variables using the alias (e.g. (gdb) print C::x).
3882 All known bugs relating to the printing of virtual base class were
3883 fixed. It is now possible to call overloaded static methods using a
3888 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3889 and reinterpret_cast<> are now handled by the C++ expression parser.
3893 Xilinx MicroBlaze microblaze-*-*
3898 Xilinx MicroBlaze microblaze
3901 * Multi-program debugging.
3903 GDB now has support for multi-program (a.k.a. multi-executable or
3904 multi-exec) debugging. This allows for debugging multiple inferiors
3905 simultaneously each running a different program under the same GDB
3906 session. See "Debugging Multiple Inferiors and Programs" in the
3907 manual for more information. This implied some user visible changes
3908 in the multi-inferior support. For example, "info inferiors" now
3909 lists inferiors that are not running yet or that have exited
3910 already. See also "New commands" and "New options" below.
3912 * New tracing features
3914 GDB's tracepoint facility now includes several new features:
3916 ** Trace state variables
3918 GDB tracepoints now include support for trace state variables, which
3919 are variables managed by the target agent during a tracing
3920 experiment. They are useful for tracepoints that trigger each
3921 other, so for instance one tracepoint can count hits in a variable,
3922 and then a second tracepoint has a condition that is true when the
3923 count reaches a particular value. Trace state variables share the
3924 $-syntax of GDB convenience variables, and can appear in both
3925 tracepoint actions and condition expressions. Use the "tvariable"
3926 command to create, and "info tvariables" to view; see "Trace State
3927 Variables" in the manual for more detail.
3931 GDB now includes an option for defining fast tracepoints, which
3932 targets may implement more efficiently, such as by installing a jump
3933 into the target agent rather than a trap instruction. The resulting
3934 speedup can be by two orders of magnitude or more, although the
3935 tradeoff is that some program locations on some target architectures
3936 might not allow fast tracepoint installation, for instance if the
3937 instruction to be replaced is shorter than the jump. To request a
3938 fast tracepoint, use the "ftrace" command, with syntax identical to
3939 the regular trace command.
3941 ** Disconnected tracing
3943 It is now possible to detach GDB from the target while it is running
3944 a trace experiment, then reconnect later to see how the experiment
3945 is going. In addition, a new variable disconnected-tracing lets you
3946 tell the target agent whether to continue running a trace if the
3947 connection is lost unexpectedly.
3951 GDB now has the ability to save the trace buffer into a file, and
3952 then use that file as a target, similarly to you can do with
3953 corefiles. You can select trace frames, print data that was
3954 collected in them, and use tstatus to display the state of the
3955 tracing run at the moment that it was saved. To create a trace
3956 file, use "tsave <filename>", and to use it, do "target tfile
3959 ** Circular trace buffer
3961 You can ask the target agent to handle the trace buffer as a
3962 circular buffer, discarding the oldest trace frames to make room for
3963 newer ones, by setting circular-trace-buffer to on. This feature may
3964 not be available for all target agents.
3969 The disassemble command, when invoked with two arguments, now requires
3970 the arguments to be comma-separated.
3973 The info variables command now displays variable definitions. Files
3974 which only declare a variable are not shown.
3977 The source command is now capable of sourcing Python scripts.
3978 This feature is dependent on the debugger being build with Python
3981 Related to this enhancement is also the introduction of a new command
3982 "set script-extension" (see below).
3984 * New commands (for set/show, see "New options" below)
3986 record save [<FILENAME>]
3987 Save a file (in core file format) containing the process record
3988 execution log for replay debugging at a later time.
3990 record restore <FILENAME>
3991 Restore the process record execution log that was saved at an
3992 earlier time, for replay debugging.
3994 add-inferior [-copies <N>] [-exec <FILENAME>]
3997 clone-inferior [-copies <N>] [ID]
3998 Make a new inferior ready to execute the same program another
3999 inferior has loaded.
4004 maint info program-spaces
4005 List the program spaces loaded into GDB.
4007 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4008 show remote interrupt-sequence
4009 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4010 as the sequence to the remote target in order to interrupt the execution.
4011 Ctrl-C is a default. Some system prefers BREAK which is high level of
4012 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4013 Magic SysRq g. It is BREAK signal and character 'g'.
4015 set remote interrupt-on-connect [on | off]
4016 show remote interrupt-on-connect
4017 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4018 remote target when gdb connects to it. This is needed when you debug
4021 set remotebreak [on | off]
4023 Deprecated. Use "set/show remote interrupt-sequence" instead.
4025 tvariable $NAME [ = EXP ]
4026 Create or modify a trace state variable.
4029 List trace state variables and their values.
4031 delete tvariable $NAME ...
4032 Delete one or more trace state variables.
4035 Evaluate the given expressions without collecting anything into the
4036 trace buffer. (Valid in tracepoint actions only.)
4038 ftrace FN / FILE:LINE / *ADDR
4039 Define a fast tracepoint at the given function, line, or address.
4041 * New expression syntax
4043 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4044 GDB now parses 0b101010 identically with 42.
4048 set follow-exec-mode new|same
4049 show follow-exec-mode
4050 Control whether GDB reuses the same inferior across an exec call or
4051 creates a new one. This is useful to be able to restart the old
4052 executable after the inferior having done an exec call.
4054 set default-collect EXPR, ...
4055 show default-collect
4056 Define a list of expressions to be collected at each tracepoint.
4057 This is a useful way to ensure essential items are not overlooked,
4058 such as registers or a critical global variable.
4060 set disconnected-tracing
4061 show disconnected-tracing
4062 If set to 1, the target is instructed to continue tracing if it
4063 loses its connection to GDB. If 0, the target is to stop tracing
4066 set circular-trace-buffer
4067 show circular-trace-buffer
4068 If set to on, the target is instructed to use a circular trace buffer
4069 and discard the oldest trace frames instead of stopping the trace due
4070 to a full trace buffer. If set to off, the trace stops when the buffer
4071 fills up. Some targets may not support this.
4073 set script-extension off|soft|strict
4074 show script-extension
4075 If set to "off", the debugger does not perform any script language
4076 recognition, and all sourced files are assumed to be GDB scripts.
4077 If set to "soft" (the default), files are sourced according to
4078 filename extension, falling back to GDB scripts if the first
4080 If set to "strict", files are sourced according to filename extension.
4082 set ada trust-PAD-over-XVS on|off
4083 show ada trust-PAD-over-XVS
4084 If off, activate a workaround against a bug in the debugging information
4085 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4086 the GCC sources for more information about the GNAT encoding and
4087 PAD types in particular). It is always safe to set this option to
4088 off, but this introduces a slight performance penalty. The default
4091 * Python API Improvements
4093 ** GDB provides the new class gdb.LazyString. This is useful in
4094 some pretty-printing cases. The new method gdb.Value.lazy_string
4095 provides a simple way to create objects of this type.
4097 ** The fields returned by gdb.Type.fields now have an
4098 `is_base_class' attribute.
4100 ** The new method gdb.Type.range returns the range of an array type.
4102 ** The new method gdb.parse_and_eval can be used to parse and
4103 evaluate an expression.
4105 * New remote packets
4108 Define a trace state variable.
4111 Get the current value of a trace state variable.
4114 Set desired tracing behavior upon disconnection.
4117 Set the trace buffer to be linear or circular.
4120 Get data about the tracepoints currently in use.
4124 Process record now works correctly with hardware watchpoints.
4126 Multiple bug fixes have been made to the mips-irix port, making it
4127 much more reliable. In particular:
4128 - Debugging threaded applications is now possible again. Previously,
4129 GDB would hang while starting the program, or while waiting for
4130 the program to stop at a breakpoint.
4131 - Attaching to a running process no longer hangs.
4132 - An error occurring while loading a core file has been fixed.
4133 - Changing the value of the PC register now works again. This fixes
4134 problems observed when using the "jump" command, or when calling
4135 a function from GDB, or even when assigning a new value to $pc.
4136 - With the "finish" and "return" commands, the return value for functions
4137 returning a small array is now correctly printed.
4138 - It is now possible to break on shared library code which gets executed
4139 during a shared library init phase (code executed while executing
4140 their .init section). Previously, the breakpoint would have no effect.
4141 - GDB is now able to backtrace through the signal handler for
4142 non-threaded programs.
4144 PIE (Position Independent Executable) programs debugging is now supported.
4145 This includes debugging execution of PIC (Position Independent Code) shared
4146 libraries although for that, it should be possible to run such libraries as an
4149 *** Changes in GDB 7.0
4151 * GDB now has an interface for JIT compilation. Applications that
4152 dynamically generate code can create symbol files in memory and register
4153 them with GDB. For users, the feature should work transparently, and
4154 for JIT developers, the interface is documented in the GDB manual in the
4155 "JIT Compilation Interface" chapter.
4157 * Tracepoints may now be conditional. The syntax is as for
4158 breakpoints; either an "if" clause appended to the "trace" command,
4159 or the "condition" command is available. GDB sends the condition to
4160 the target for evaluation using the same bytecode format as is used
4161 for tracepoint actions.
4163 * The disassemble command now supports: an optional /r modifier, print the
4164 raw instructions in hex as well as in symbolic form, and an optional /m
4165 modifier to print mixed source+assembly.
4167 * Process record and replay
4169 In a architecture environment that supports ``process record and
4170 replay'', ``process record and replay'' target can record a log of
4171 the process execution, and replay it with both forward and reverse
4174 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4175 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4176 set execution-direction {forward|reverse}, for targets that support
4179 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4180 feature is available with a native GDB running on kernel version
4183 * GDB now has support for multi-byte and wide character sets on the
4184 target. Strings whose character type is wchar_t, char16_t, or
4185 char32_t are now correctly printed. GDB supports wide- and unicode-
4186 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4187 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4188 `printf'. This feature requires iconv to work properly; if your
4189 system does not have a working iconv, GDB can use GNU libiconv. See
4190 the installation instructions for more information.
4192 * GDB now supports automatic retrieval of shared library files from
4193 remote targets. To use this feature, specify a system root that begins
4194 with the `remote:' prefix, either via the `set sysroot' command or via
4195 the `--with-sysroot' configure-time option.
4197 * "info sharedlibrary" now takes an optional regex of libraries to show,
4198 and it now reports if a shared library has no debugging information.
4200 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4201 now complete on file names.
4203 * When completing in expressions, gdb will attempt to limit
4204 completions to allowable structure or union fields, where appropriate.
4205 For instance, consider:
4207 # struct example { int f1; double f2; };
4208 # struct example variable;
4211 If the user types TAB at the end of this command line, the available
4212 completions will be "f1" and "f2".
4214 * Inlined functions are now supported. They show up in backtraces, and
4215 the "step", "next", and "finish" commands handle them automatically.
4217 * GDB now supports the token-splicing (##) and stringification (#)
4218 operators when expanding macros. It also supports variable-arity
4221 * GDB now supports inspecting extra signal information, exported by
4222 the new $_siginfo convenience variable. The feature is currently
4223 implemented on linux ARM, i386 and amd64.
4225 * GDB can now display the VFP floating point registers and NEON vector
4226 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4227 can provide these registers (requires Linux 2.6.30 or later). Remote
4228 and simulator targets may also provide them.
4230 * New remote packets
4233 Search memory for a sequence of bytes.
4236 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4237 operation over reliable transport links. Use of this packet is
4238 controlled by the `set remote noack-packet' command.
4241 Kill the process with the specified process ID. Use this in preference
4242 to `k' when multiprocess protocol extensions are supported.
4245 Obtains additional operating system information
4249 Read or write additional signal information.
4251 * Removed remote protocol undocumented extension
4253 An undocumented extension to the remote protocol's `S' stop reply
4254 packet that permitted the stub to pass a process id was removed.
4255 Remote servers should use the `T' stop reply packet instead.
4257 * GDB now supports multiple function calling conventions according to the
4258 DWARF-2 DW_AT_calling_convention function attribute.
4260 * The SH target utilizes the aforementioned change to distinguish between gcc
4261 and Renesas calling convention. It also adds the new CLI commands
4262 `set/show sh calling-convention'.
4264 * GDB can now read compressed debug sections, as produced by GNU gold
4265 with the --compress-debug-sections=zlib flag.
4267 * 64-bit core files are now supported on AIX.
4269 * Thread switching is now supported on Tru64.
4271 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4272 which will be allocated using malloc later in program execution.
4274 * The qXfer:libraries:read remote protocol packet now allows passing a
4275 list of section offsets.
4277 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4278 conditions handling signals delivered during attach or thread creation
4279 have also been fixed.
4281 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4282 From the user's standpoint, all unqualified instances of True and False
4283 are treated as the standard definitions, regardless of context.
4285 * GDB now parses C++ symbol and type names more flexibly. For
4288 template<typename T> class C { };
4291 GDB will now correctly handle all of:
4293 ptype C<char const *>
4294 ptype C<char const*>
4295 ptype C<const char *>
4296 ptype C<const char*>
4298 * New features in the GDB remote stub, gdbserver
4300 - The "--wrapper" command-line argument tells gdbserver to use a
4301 wrapper program to launch programs for debugging.
4303 - On PowerPC and S/390 targets, it is now possible to use a single
4304 gdbserver executable to debug both 32-bit and 64-bit programs.
4305 (This requires gdbserver itself to be built as a 64-bit executable.)
4307 - gdbserver uses the new noack protocol mode for TCP connections to
4308 reduce communications latency, if also supported and enabled in GDB.
4310 - Support for the sparc64-linux-gnu target is now included in
4313 - The amd64-linux build of gdbserver now supports debugging both
4314 32-bit and 64-bit programs.
4316 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4317 now support hardware watchpoints, and will use them automatically
4322 GDB now has support for scripting using Python. Whether this is
4323 available is determined at configure time.
4325 New GDB commands can now be written in Python.
4327 * Ada tasking support
4329 Ada tasks can now be inspected in GDB. The following commands have
4333 Print the list of Ada tasks.
4335 Print detailed information about task number N.
4337 Print the task number of the current task.
4339 Switch the context of debugging to task number N.
4341 * Support for user-defined prefixed commands. The "define" command can
4342 add new commands to existing prefixes, e.g. "target".
4344 * Multi-inferior, multi-process debugging.
4346 GDB now has generalized support for multi-inferior debugging. See
4347 "Debugging Multiple Inferiors" in the manual for more information.
4348 Although availability still depends on target support, the command
4349 set is more uniform now. The GNU/Linux specific multi-forks support
4350 has been migrated to this new framework. This implied some user
4351 visible changes; see "New commands" and also "Removed commands"
4354 * Target descriptions can now describe the target OS ABI. See the
4355 "Target Description Format" section in the user manual for more
4358 * Target descriptions can now describe "compatible" architectures
4359 to indicate that the target can execute applications for a different
4360 architecture in addition to those for the main target architecture.
4361 See the "Target Description Format" section in the user manual for
4364 * Multi-architecture debugging.
4366 GDB now includes general supports for debugging applications on
4367 hybrid systems that use more than one single processor architecture
4368 at the same time. Each such hybrid architecture still requires
4369 specific support to be added. The only hybrid architecture supported
4370 in this version of GDB is the Cell Broadband Engine.
4372 * GDB now supports integrated debugging of Cell/B.E. applications that
4373 use both the PPU and SPU architectures. To enable support for hybrid
4374 Cell/B.E. debugging, you need to configure GDB to support both the
4375 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4376 --enable-targets configure option.
4378 * Non-stop mode debugging.
4380 For some targets, GDB now supports an optional mode of operation in
4381 which you can examine stopped threads while other threads continue
4382 to execute freely. This is referred to as non-stop mode, with the
4383 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4384 section in the user manual for more information.
4386 To be able to support remote non-stop debugging, a remote stub needs
4387 to implement the non-stop mode remote protocol extensions, as
4388 described in the "Remote Non-Stop" section of the user manual. The
4389 GDB remote stub, gdbserver, has been adjusted to support these
4390 extensions on linux targets.
4392 * New commands (for set/show, see "New options" below)
4394 catch syscall [NAME(S) | NUMBER(S)]
4395 Catch system calls. Arguments, which should be names of system
4396 calls or their numbers, mean catch only those syscalls. Without
4397 arguments, every syscall will be caught. When the inferior issues
4398 any of the specified syscalls, GDB will stop and announce the system
4399 call, both when it is called and when its call returns. This
4400 feature is currently available with a native GDB running on the
4401 Linux Kernel, under the following architectures: x86, x86_64,
4402 PowerPC and PowerPC64.
4404 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4406 Search memory for a sequence of bytes.
4408 maint set python print-stack
4409 maint show python print-stack
4410 Show a stack trace when an error is encountered in a Python script.
4413 Invoke CODE by passing it to the Python interpreter.
4418 These allow macros to be defined, undefined, and listed
4422 Show operating system information about processes.
4425 List the inferiors currently under GDB's control.
4428 Switch focus to inferior number NUM.
4431 Detach from inferior number NUM.
4434 Kill inferior number NUM.
4438 set spu stop-on-load
4439 show spu stop-on-load
4440 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4442 set spu auto-flush-cache
4443 show spu auto-flush-cache
4444 Control whether to automatically flush the software-managed cache
4445 during Cell/B.E. debugging.
4447 set sh calling-convention
4448 show sh calling-convention
4449 Control the calling convention used when calling SH target functions.
4452 show debug timestamp
4453 Control display of timestamps with GDB debugging output.
4455 set disassemble-next-line
4456 show disassemble-next-line
4457 Control display of disassembled source lines or instructions when
4460 set remote noack-packet
4461 show remote noack-packet
4462 Set/show the use of remote protocol QStartNoAckMode packet. See above
4463 under "New remote packets."
4465 set remote query-attached-packet
4466 show remote query-attached-packet
4467 Control use of remote protocol `qAttached' (query-attached) packet.
4469 set remote read-siginfo-object
4470 show remote read-siginfo-object
4471 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4474 set remote write-siginfo-object
4475 show remote write-siginfo-object
4476 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4479 set remote reverse-continue
4480 show remote reverse-continue
4481 Control use of remote protocol 'bc' (reverse-continue) packet.
4483 set remote reverse-step
4484 show remote reverse-step
4485 Control use of remote protocol 'bs' (reverse-step) packet.
4487 set displaced-stepping
4488 show displaced-stepping
4489 Control displaced stepping mode. Displaced stepping is a way to
4490 single-step over breakpoints without removing them from the debuggee.
4491 Also known as "out-of-line single-stepping".
4494 show debug displaced
4495 Control display of debugging info for displaced stepping.
4497 maint set internal-error
4498 maint show internal-error
4499 Control what GDB does when an internal error is detected.
4501 maint set internal-warning
4502 maint show internal-warning
4503 Control what GDB does when an internal warning is detected.
4508 Use a wrapper program to launch programs for debugging.
4510 set multiple-symbols (all|ask|cancel)
4511 show multiple-symbols
4512 The value of this variable can be changed to adjust the debugger behavior
4513 when an expression or a breakpoint location contains an ambiguous symbol
4514 name (an overloaded function name, for instance).
4516 set breakpoint always-inserted
4517 show breakpoint always-inserted
4518 Keep breakpoints always inserted in the target, as opposed to inserting
4519 them when resuming the target, and removing them when the target stops.
4520 This option can improve debugger performance on slow remote targets.
4522 set arm fallback-mode (arm|thumb|auto)
4523 show arm fallback-mode
4524 set arm force-mode (arm|thumb|auto)
4526 These commands control how ARM GDB determines whether instructions
4527 are ARM or Thumb. The default for both settings is auto, which uses
4528 the current CPSR value for instructions without symbols; previous
4529 versions of GDB behaved as if "set arm fallback-mode arm".
4531 set disable-randomization
4532 show disable-randomization
4533 Standalone programs run with the virtual address space randomization enabled
4534 by default on some platforms. This option keeps the addresses stable across
4535 multiple debugging sessions.
4539 Control whether other threads are stopped or not when some thread hits
4544 Requests that asynchronous execution is enabled in the target, if available.
4545 In this case, it's possible to resume target in the background, and interact
4546 with GDB while the target is running. "show target-async" displays the
4547 current state of asynchronous execution of the target.
4549 set target-wide-charset
4550 show target-wide-charset
4551 The target-wide-charset is the name of the character set that GDB
4552 uses when printing characters whose type is wchar_t.
4554 set tcp auto-retry (on|off)
4556 set tcp connect-timeout
4557 show tcp connect-timeout
4558 These commands allow GDB to retry failed TCP connections to a remote stub
4559 with a specified timeout period; this is useful if the stub is launched
4560 in parallel with GDB but may not be ready to accept connections immediately.
4562 set libthread-db-search-path
4563 show libthread-db-search-path
4564 Control list of directories which GDB will search for appropriate
4567 set schedule-multiple (on|off)
4568 show schedule-multiple
4569 Allow GDB to resume all threads of all processes or only threads of
4570 the current process.
4574 Use more aggressive caching for accesses to the stack. This improves
4575 performance of remote debugging (particularly backtraces) without
4576 affecting correctness.
4578 set interactive-mode (on|off|auto)
4579 show interactive-mode
4580 Control whether GDB runs in interactive mode (on) or not (off).
4581 When in interactive mode, GDB waits for the user to answer all
4582 queries. Otherwise, GDB does not wait and assumes the default
4583 answer. When set to auto (the default), GDB determines which
4584 mode to use based on the stdin settings.
4589 For program forks, this is replaced by the new more generic `info
4590 inferiors' command. To list checkpoints, you can still use the
4591 `info checkpoints' command, which was an alias for the `info forks'
4595 Replaced by the new `inferior' command. To switch between
4596 checkpoints, you can still use the `restart' command, which was an
4597 alias for the `fork' command.
4600 This is removed, since some targets don't have a notion of
4601 processes. To switch between processes, you can still use the
4602 `inferior' command using GDB's own inferior number.
4605 For program forks, this is replaced by the new more generic `kill
4606 inferior' command. To delete a checkpoint, you can still use the
4607 `delete checkpoint' command, which was an alias for the `delete
4611 For program forks, this is replaced by the new more generic `detach
4612 inferior' command. To detach a checkpoint, you can still use the
4613 `detach checkpoint' command, which was an alias for the `detach
4616 * New native configurations
4618 x86/x86_64 Darwin i[34567]86-*-darwin*
4620 x86_64 MinGW x86_64-*-mingw*
4624 Lattice Mico32 lm32-*
4625 x86 DICOS i[34567]86-*-dicos*
4626 x86_64 DICOS x86_64-*-dicos*
4629 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4630 (mingw32ce) debugging.
4636 These commands were actually not implemented on any target.
4638 *** Changes in GDB 6.8
4640 * New native configurations
4642 NetBSD/hppa hppa*-*netbsd*
4643 Xtensa GNU/Linux xtensa*-*-linux*
4647 NetBSD/hppa hppa*-*-netbsd*
4648 Xtensa GNU/Linux xtensa*-*-linux*
4650 * Change in command line behavior -- corefiles vs. process ids.
4652 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4653 attaching to process NUMBER fails, GDB no longer attempts to open a
4654 core file named NUMBER. Attaching to a program using the -c option
4655 is no longer supported. Instead, use the '-p' or '--pid' options.
4657 * GDB can now be built as a native debugger for debugging Windows x86
4658 (mingw32) Portable Executable (PE) programs.
4660 * Pending breakpoints no longer change their number when their address
4663 * GDB now supports breakpoints with multiple locations,
4664 including breakpoints on C++ constructors, inside C++ templates,
4665 and in inlined functions.
4667 * GDB's ability to debug optimized code has been improved. GDB more
4668 accurately identifies function bodies and lexical blocks that occupy
4669 more than one contiguous range of addresses.
4671 * Target descriptions can now describe registers for PowerPC.
4673 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4674 registers on PowerPC targets.
4676 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4677 targets even when the libthread_db library is not available.
4679 * The GDB remote stub, gdbserver, now supports the new file transfer
4680 commands (remote put, remote get, and remote delete).
4682 * The GDB remote stub, gdbserver, now supports run and attach in
4683 extended-remote mode.
4685 * hppa*64*-*-hpux11* target broken
4686 The debugger is unable to start a program and fails with the following
4687 error: "Error trying to get information about dynamic linker".
4688 The gdb-6.7 release is also affected.
4690 * GDB now supports the --enable-targets= configure option to allow
4691 building a single GDB executable that supports multiple remote
4692 target architectures.
4694 * GDB now supports debugging C and C++ programs which use the
4695 Decimal Floating Point extension. In addition, the PowerPC target
4696 now has a set of pseudo-registers to inspect decimal float values
4697 stored in two consecutive float registers.
4699 * The -break-insert MI command can optionally create pending
4702 * Improved support for debugging Ada
4703 Many improvements to the Ada language support have been made. These
4705 - Better support for Ada2005 interface types
4706 - Improved handling of arrays and slices in general
4707 - Better support for Taft-amendment types
4708 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4710 - Improved command completion in Ada
4713 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4718 set print frame-arguments (all|scalars|none)
4719 show print frame-arguments
4720 The value of this variable can be changed to control which argument
4721 values should be printed by the debugger when displaying a frame.
4726 Transfer files to and from a remote target, and delete remote files.
4733 Transfer files to and from a remote target, and delete remote files.
4735 * New remote packets
4742 Open, close, read, write, and delete files on the remote system.
4745 Attach to an existing process on the remote system, in extended-remote
4749 Run a new process on the remote system, in extended-remote mode.
4751 *** Changes in GDB 6.7
4753 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4754 bfd, libiberty and opcodes, as revealed by static analysis donated by
4755 Coverity, Inc. (http://scan.coverity.com).
4757 * When looking up multiply-defined global symbols, GDB will now prefer the
4758 symbol definition in the current shared library if it was built using the
4759 -Bsymbolic linker option.
4761 * When the Text User Interface (TUI) is not configured, GDB will now
4762 recognize the -tui command-line option and print a message that the TUI
4765 * The GDB remote stub, gdbserver, now has lower overhead for high
4766 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4768 * GDB for MIPS targets now autodetects whether a remote target provides
4769 32-bit or 64-bit register values.
4771 * Support for C++ member pointers has been improved.
4773 * GDB now understands XML target descriptions, which specify the
4774 target's overall architecture. GDB can read a description from
4775 a local file or over the remote serial protocol.
4777 * Vectors of single-byte data use a new integer type which is not
4778 automatically displayed as character or string data.
4780 * The /s format now works with the print command. It displays
4781 arrays of single-byte integers and pointers to single-byte integers
4784 * Target descriptions can now describe target-specific registers,
4785 for architectures which have implemented the support (currently
4786 only ARM, M68K, and MIPS).
4788 * GDB and the GDB remote stub, gdbserver, now support the XScale
4791 * The GDB remote stub, gdbserver, has been updated to support
4792 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4793 has been rewritten to use the standard GDB remote protocol.
4795 * GDB can now step into C++ functions which are called through thunks.
4797 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4799 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4800 layout. It also supports a TextSeg= and DataSeg= response when only
4801 segment base addresses (rather than offsets) are available.
4803 * The /i format now outputs any trailing branch delay slot instructions
4804 immediately following the last instruction within the count specified.
4806 * The GDB remote protocol "T" stop reply packet now supports a
4807 "library" response. Combined with the new "qXfer:libraries:read"
4808 packet, this response allows GDB to debug shared libraries on targets
4809 where the operating system manages the list of loaded libraries (e.g.
4810 Windows and SymbianOS).
4812 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4813 (DLLs) on Windows and Windows CE targets.
4815 * GDB now supports a faster verification that a .debug file matches its binary
4816 according to its build-id signature, if the signature is present.
4822 Enable or disable hardware flow control (RTS/CTS) on the serial port
4823 when debugging using remote targets.
4825 set mem inaccessible-by-default
4826 show mem inaccessible-by-default
4827 If the target supplies a memory map, for instance via the remote
4828 protocol's "qXfer:memory-map:read" packet, setting this variable
4829 prevents GDB from accessing memory outside the memory map. This
4830 is useful for targets with memory mapped registers or which react
4831 badly to accesses of unmapped address space.
4833 set breakpoint auto-hw
4834 show breakpoint auto-hw
4835 If the target supplies a memory map, for instance via the remote
4836 protocol's "qXfer:memory-map:read" packet, setting this variable
4837 lets GDB use hardware breakpoints automatically for memory regions
4838 where it can not use software breakpoints. This covers both the
4839 "break" command and internal breakpoints used for other commands
4840 including "next" and "finish".
4843 catch exception unhandled
4844 Stop the program execution when Ada exceptions are raised.
4847 Stop the program execution when an Ada assertion failed.
4851 Set an alternate system root for target files. This is a more
4852 general version of "set solib-absolute-prefix", which is now
4853 an alias to "set sysroot".
4856 Provide extended SPU facility status information. This set of
4857 commands is available only when debugging the Cell/B.E. SPU
4860 * New native configurations
4862 OpenBSD/sh sh*-*openbsd*
4865 unset tdesc filename
4867 Use the specified local file as an XML target description, and do
4868 not query the target for its built-in description.
4872 OpenBSD/sh sh*-*-openbsd*
4873 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4874 Toshiba Media Processor mep-elf
4876 * New remote packets
4879 Ignore the specified signals; pass them directly to the debugged program
4880 without stopping other threads or reporting them to GDB.
4882 qXfer:features:read:
4883 Read an XML target description from the target, which describes its
4888 Read or write contents of an spufs file on the target system. These
4889 packets are available only on the Cell/B.E. SPU architecture.
4891 qXfer:libraries:read:
4892 Report the loaded shared libraries. Combined with new "T" packet
4893 response, this packet allows GDB to debug shared libraries on
4894 targets where the operating system manages the list of loaded
4895 libraries (e.g. Windows and SymbianOS).
4899 Support for these obsolete configurations has been removed.
4907 i[34567]86-*-lynxos*
4908 i[34567]86-*-netware*
4909 i[34567]86-*-sco3.2v5*
4910 i[34567]86-*-sco3.2v4*
4912 i[34567]86-*-sysv4.2*
4915 i[34567]86-*-unixware2*
4916 i[34567]86-*-unixware*
4925 * Other removed features
4932 Various m68k-only ROM monitors.
4939 Various Renesas ROM monitors and debugging interfaces for SH and
4944 Support for a Macraigor serial interface to on-chip debugging.
4945 GDB does not directly support the newer parallel or USB
4950 A debug information format. The predecessor to DWARF 2 and
4951 DWARF 3, which are still supported.
4953 Support for the HP aCC compiler on HP-UX/PA-RISC
4955 SOM-encapsulated symbolic debugging information, automatic
4956 invocation of pxdb, and the aCC custom C++ ABI. This does not
4957 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4958 with aCC can still be debugged on an assembly level.
4960 MIPS ".pdr" sections
4962 A MIPS-specific format used to describe stack frame layout
4963 in debugging information.
4967 GDB could work with an older version of Guile to debug
4968 the interpreter and Scheme programs running in it.
4970 set mips stack-arg-size
4971 set mips saved-gpreg-size
4973 Use "set mips abi" to control parameter passing for MIPS.
4975 *** Changes in GDB 6.6
4980 Cell Broadband Engine SPU spu-elf
4982 * GDB can now be configured as a cross-debugger targeting native Windows
4983 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4984 running on a Windows system over TCP/IP to debug Windows programs.
4986 * The GDB remote stub, gdbserver, has been updated to support Windows and
4987 Cygwin debugging. Both single-threaded and multi-threaded programs are
4990 * The "set trust-readonly-sections" command works again. This command was
4991 broken in GDB 6.3, 6.4, and 6.5.
4993 * The "load" command now supports writing to flash memory, if the remote
4994 stub provides the required support.
4996 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4997 longer requires symbolic debug information (e.g. DWARF-2).
5002 unset substitute-path
5003 show substitute-path
5004 Manage a list of substitution rules that GDB uses to rewrite the name
5005 of the directories where the sources are located. This can be useful
5006 for instance when the sources were moved to a different location
5007 between compilation and debugging.
5011 Print each CLI command as it is executed. Each command is prefixed with
5012 a number of `+' symbols representing the nesting depth.
5013 The source command now has a `-v' option to enable the same feature.
5017 The ARM Demon monitor support (RDP protocol, "target rdp").
5019 Kernel Object Display, an embedded debugging feature which only worked with
5020 an obsolete version of Cisco IOS.
5022 The 'set download-write-size' and 'show download-write-size' commands.
5024 * New remote packets
5027 Tell a stub about GDB client features, and request remote target features.
5028 The first feature implemented is PacketSize, which allows the target to
5029 specify the size of packets it can handle - to minimize the number of
5030 packets required and improve performance when connected to a remote
5034 Fetch an OS auxilliary vector from the remote stub. This packet is a
5035 more efficient replacement for qPart:auxv:read.
5037 qXfer:memory-map:read:
5038 Fetch a memory map from the remote stub, including information about
5039 RAM, ROM, and flash memory devices.
5044 Erase and program a flash memory device.
5046 * Removed remote packets
5049 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5050 used it, and only gdbserver implemented it.
5052 *** Changes in GDB 6.5
5056 Renesas M32C/M16C m32c-elf
5058 Morpho Technologies ms1 ms1-elf
5062 init-if-undefined Initialize a convenience variable, but
5063 only if it doesn't already have a value.
5065 The following commands are presently only implemented for native GNU/Linux:
5067 checkpoint Save a snapshot of the program state.
5069 restart <n> Return the program state to a
5070 previously saved state.
5072 info checkpoints List currently saved checkpoints.
5074 delete-checkpoint <n> Delete a previously saved checkpoint.
5076 set|show detach-on-fork Tell gdb whether to detach from a newly
5077 forked process, or to keep debugging it.
5079 info forks List forks of the user program that
5080 are available to be debugged.
5082 fork <n> Switch to debugging one of several
5083 forks of the user program that are
5084 available to be debugged.
5086 delete-fork <n> Delete a fork from the list of forks
5087 that are available to be debugged (and
5088 kill the forked process).
5090 detach-fork <n> Delete a fork from the list of forks
5091 that are available to be debugged (and
5092 allow the process to continue).
5096 Morpho Technologies ms2 ms1-elf
5098 * Improved Windows host support
5100 GDB now builds as a cross debugger hosted on i686-mingw32, including
5101 native console support, and remote communications using either
5102 network sockets or serial ports.
5104 * Improved Modula-2 language support
5106 GDB can now print most types in the Modula-2 syntax. This includes:
5107 basic types, set types, record types, enumerated types, range types,
5108 pointer types and ARRAY types. Procedure var parameters are correctly
5109 printed and hexadecimal addresses and character constants are also
5110 written in the Modula-2 syntax. Best results can be obtained by using
5111 GNU Modula-2 together with the -gdwarf-2 command line option.
5115 The ARM rdi-share module.
5117 The Netware NLM debug server.
5119 *** Changes in GDB 6.4
5121 * New native configurations
5123 OpenBSD/arm arm*-*-openbsd*
5124 OpenBSD/mips64 mips64-*-openbsd*
5128 Morpho Technologies ms1 ms1-elf
5130 * New command line options
5132 --batch-silent As for --batch, but totally silent.
5133 --return-child-result The debugger will exist with the same value
5134 the child (debugged) program exited with.
5135 --eval-command COMMAND, -ex COMMAND
5136 Execute a single GDB CLI command. This may be
5137 specified multiple times and in conjunction
5138 with the --command (-x) option.
5140 * Deprecated commands removed
5142 The following commands, that were deprecated in 2000, have been
5146 set|show arm disassembly-flavor set|show arm disassembler
5147 othernames set arm disassembler
5148 set|show remotedebug set|show debug remote
5149 set|show archdebug set|show debug arch
5150 set|show eventdebug set|show debug event
5153 * New BSD user-level threads support
5155 It is now possible to debug programs using the user-level threads
5156 library on OpenBSD and FreeBSD. Currently supported (target)
5159 FreeBSD/amd64 x86_64-*-freebsd*
5160 FreeBSD/i386 i386-*-freebsd*
5161 OpenBSD/i386 i386-*-openbsd*
5163 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5164 are not yet supported.
5166 * New support for Matsushita MN10300 w/sim added
5167 (Work in progress). mn10300-elf.
5169 * REMOVED configurations and files
5171 VxWorks and the XDR protocol *-*-vxworks
5172 Motorola MCORE mcore-*-*
5173 National Semiconductor NS32000 ns32k-*-*
5175 * New "set print array-indexes" command
5177 After turning this setting "on", GDB prints the index of each element
5178 when displaying arrays. The default is "off" to preserve the previous
5181 * VAX floating point support
5183 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5185 * User-defined command support
5187 In addition to using $arg0..$arg9 for argument passing, it is now possible
5188 to use $argc to determine now many arguments have been passed. See the
5189 section on user-defined commands in the user manual for more information.
5191 *** Changes in GDB 6.3:
5193 * New command line option
5195 GDB now accepts -l followed by a number to set the timeout for remote
5198 * GDB works with GCC -feliminate-dwarf2-dups
5200 GDB now supports a more compact representation of DWARF-2 debug
5201 information using DW_FORM_ref_addr references. These are produced
5202 by GCC with the option -feliminate-dwarf2-dups and also by some
5203 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5204 to use -feliminate-dwarf2-dups.
5206 * Internationalization
5208 When supported by the host system, GDB will be built with
5209 internationalization (libintl). The task of marking up the sources is
5210 continued, we're looking forward to our first translation.
5214 Initial support for debugging programs compiled with the GNAT
5215 implementation of the Ada programming language has been integrated
5216 into GDB. In this release, support is limited to expression evaluation.
5218 * New native configurations
5220 GNU/Linux/m32r m32r-*-linux-gnu
5224 GDB's remote protocol now includes support for the 'p' packet. This
5225 packet is used to fetch individual registers from a remote inferior.
5227 * END-OF-LIFE registers[] compatibility module
5229 GDB's internal register infrastructure has been completely rewritten.
5230 The new infrastructure making possible the implementation of key new
5231 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5234 GDB 6.3 will be the last release to include the registers[]
5235 compatibility module that allowed out-of-date configurations to
5236 continue to work. This change directly impacts the following
5246 powerpc bdm protocol
5248 Unless there is activity to revive these configurations, they will be
5249 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5251 * OBSOLETE configurations and files
5253 Configurations that have been declared obsolete in this release have
5254 been commented out. Unless there is activity to revive these
5255 configurations, the next release of GDB will have their sources
5256 permanently REMOVED.
5265 *** Changes in GDB 6.2.1:
5267 * MIPS `break main; run' gave an heuristic-fence-post warning
5269 When attempting to run even a simple program, a warning about
5270 heuristic-fence-post being hit would be reported. This problem has
5273 * MIPS IRIX 'long double' crashed GDB
5275 When examining a long double variable, GDB would get a segmentation
5276 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5277 IRIX long double values).
5281 A bug in the VAX stack code was causing problems with the "next"
5282 command. This problem has been fixed.
5284 *** Changes in GDB 6.2:
5286 * Fix for ``many threads''
5288 On GNU/Linux systems that use the NPTL threads library, a program
5289 rapidly creating and deleting threads would confuse GDB leading to the
5292 ptrace: No such process.
5293 thread_db_get_info: cannot get thread info: generic error
5295 This problem has been fixed.
5297 * "-async" and "-noasync" options removed.
5299 Support for the broken "-noasync" option has been removed (it caused
5302 * New ``start'' command.
5304 This command runs the program until the beginning of the main procedure.
5306 * New BSD Kernel Data Access Library (libkvm) interface
5308 Using ``target kvm'' it is now possible to debug kernel core dumps and
5309 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5310 platforms. Currently supported (native-only) configurations are:
5312 FreeBSD/amd64 x86_64-*-freebsd*
5313 FreeBSD/i386 i?86-*-freebsd*
5314 NetBSD/i386 i?86-*-netbsd*
5315 NetBSD/m68k m68*-*-netbsd*
5316 NetBSD/sparc sparc-*-netbsd*
5317 OpenBSD/amd64 x86_64-*-openbsd*
5318 OpenBSD/i386 i?86-*-openbsd*
5319 OpenBSD/m68k m68*-openbsd*
5320 OpenBSD/sparc sparc-*-openbsd*
5322 * Signal trampoline code overhauled
5324 Many generic problems with GDB's signal handling code have been fixed.
5325 These include: backtraces through non-contiguous stacks; recognition
5326 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5327 call; backtrace through a signal trampoline; step into and out of
5328 signal handlers; and single-stepping in the signal trampoline.
5330 Please note that kernel bugs are a limiting factor here. These
5331 features have been shown to work on an s390 GNU/Linux system that
5332 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5334 * Cygwin support for DWARF 2 added.
5336 * New native configurations
5338 GNU/Linux/hppa hppa*-*-linux*
5339 OpenBSD/hppa hppa*-*-openbsd*
5340 OpenBSD/m68k m68*-*-openbsd*
5341 OpenBSD/m88k m88*-*-openbsd*
5342 OpenBSD/powerpc powerpc-*-openbsd*
5343 NetBSD/vax vax-*-netbsd*
5344 OpenBSD/vax vax-*-openbsd*
5346 * END-OF-LIFE frame compatibility module
5348 GDB's internal frame infrastructure has been completely rewritten.
5349 The new infrastructure making it possible to support key new features
5350 including DWARF 2 Call Frame Information. To aid in the task of
5351 migrating old configurations to this new infrastructure, a
5352 compatibility module, that allowed old configurations to continue to
5353 work, was also included.
5355 GDB 6.2 will be the last release to include this frame compatibility
5356 module. This change directly impacts the following configurations:
5366 Unless there is activity to revive these configurations, they will be
5367 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5369 * REMOVED configurations and files
5371 Sun 3, running SunOS 3 m68*-*-sunos3*
5372 Sun 3, running SunOS 4 m68*-*-sunos4*
5373 Sun 2, running SunOS 3 m68000-*-sunos3*
5374 Sun 2, running SunOS 4 m68000-*-sunos4*
5375 Motorola 680x0 running LynxOS m68*-*-lynxos*
5376 AT&T 3b1/Unix pc m68*-att-*
5377 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5378 decstation mips-dec-* mips-little-*
5379 riscos mips-*-riscos* mips-*-sysv*
5380 sonymips mips-sony-*
5381 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5383 *** Changes in GDB 6.1.1:
5385 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5387 The TUI (Text-mode User Interface) is now built as part of a default
5388 GDB configuration. It is enabled by either selecting the TUI with the
5389 command line option "-i=tui" or by running the separate "gdbtui"
5390 program. For more information on the TUI, see the manual "Debugging
5393 * Pending breakpoint support (also included in GDB 6.1)
5395 Support has been added to allow you to specify breakpoints in shared
5396 libraries that have not yet been loaded. If a breakpoint location
5397 cannot be found, and the "breakpoint pending" option is set to auto,
5398 GDB queries you if you wish to make the breakpoint pending on a future
5399 shared-library load. If and when GDB resolves the breakpoint symbol,
5400 the pending breakpoint is removed as one or more regular breakpoints
5403 Pending breakpoints are very useful for GCJ Java debugging.
5405 * Fixed ISO-C build problems
5407 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5408 non ISO-C code that stopped them being built using a more strict ISO-C
5409 compiler (e.g., IBM's C compiler).
5411 * Fixed build problem on IRIX 5
5413 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5414 wasn't able to compile compile on an IRIX 5 system.
5416 * Added execute permission to gdb/gdbserver/configure
5418 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5419 permission. This bug would cause configure to fail on a number of
5420 systems (Solaris, IRIX). Ref: server/519.
5422 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5424 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5425 has been updated to use constant array sizes.
5427 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5429 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5430 its generated DWARF Call Frame Info. This encoding was causing GDB to
5431 panic, that panic has been fixed. Ref: gdb/1628.
5433 * Fixed a problem when examining parameters in shared library code.
5435 When examining parameters in optimized shared library code generated
5436 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5437 not available''. GDB now correctly displays the variable's value.
5439 *** Changes in GDB 6.1:
5441 * Removed --with-mmalloc
5443 Support for the mmalloc memory manager has been removed, as it
5444 conflicted with the internal gdb byte cache.
5446 * Changes in AMD64 configurations
5448 The AMD64 target now includes the %cs and %ss registers. As a result
5449 the AMD64 remote protocol has changed; this affects the floating-point
5450 and SSE registers. If you rely on those registers for your debugging,
5451 you should upgrade gdbserver on the remote side.
5453 * Revised SPARC target
5455 The SPARC target has been completely revised, incorporating the
5456 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5457 support for LynxOS and SunOS 4 has been dropped. Calling functions
5458 from within GDB on operating systems with a non-executable stack
5459 (Solaris, OpenBSD) now works.
5463 GDB has a new C++ demangler which does a better job on the mangled
5464 names generated by current versions of g++. It also runs faster, so
5465 with this and other changes gdb should now start faster on large C++
5468 * DWARF 2 Location Expressions
5470 GDB support for location expressions has been extended to support function
5471 arguments and frame bases. Older versions of GDB could crash when they
5474 * C++ nested types and namespaces
5476 GDB's support for nested types and namespaces in C++ has been
5477 improved, especially if you use the DWARF 2 debugging format. (This
5478 is the default for recent versions of GCC on most platforms.)
5479 Specifically, if you have a class "Inner" defined within a class or
5480 namespace "Outer", then GDB realizes that the class's name is
5481 "Outer::Inner", not simply "Inner". This should greatly reduce the
5482 frequency of complaints about not finding RTTI symbols. In addition,
5483 if you are stopped at inside of a function defined within a namespace,
5484 GDB modifies its name lookup accordingly.
5486 * New native configurations
5488 NetBSD/amd64 x86_64-*-netbsd*
5489 OpenBSD/amd64 x86_64-*-openbsd*
5490 OpenBSD/alpha alpha*-*-openbsd*
5491 OpenBSD/sparc sparc-*-openbsd*
5492 OpenBSD/sparc64 sparc64-*-openbsd*
5494 * New debugging protocols
5496 M32R with SDI protocol m32r-*-elf*
5498 * "set prompt-escape-char" command deleted.
5500 The command "set prompt-escape-char" has been deleted. This command,
5501 and its very obscure effect on GDB's prompt, was never documented,
5502 tested, nor mentioned in the NEWS file.
5504 * OBSOLETE configurations and files
5506 Configurations that have been declared obsolete in this release have
5507 been commented out. Unless there is activity to revive these
5508 configurations, the next release of GDB will have their sources
5509 permanently REMOVED.
5511 Sun 3, running SunOS 3 m68*-*-sunos3*
5512 Sun 3, running SunOS 4 m68*-*-sunos4*
5513 Sun 2, running SunOS 3 m68000-*-sunos3*
5514 Sun 2, running SunOS 4 m68000-*-sunos4*
5515 Motorola 680x0 running LynxOS m68*-*-lynxos*
5516 AT&T 3b1/Unix pc m68*-att-*
5517 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5518 decstation mips-dec-* mips-little-*
5519 riscos mips-*-riscos* mips-*-sysv*
5520 sonymips mips-sony-*
5521 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5523 * REMOVED configurations and files
5525 SGI Irix-4.x mips-sgi-irix4 or iris4
5526 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5527 Z8000 simulator z8k-zilog-none or z8ksim
5528 Matsushita MN10200 w/simulator mn10200-*-*
5529 H8/500 simulator h8500-hitachi-hms or h8500hms
5530 HP/PA running BSD hppa*-*-bsd*
5531 HP/PA running OSF/1 hppa*-*-osf*
5532 HP/PA Pro target hppa*-*-pro*
5533 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5534 386BSD i[3456]86-*-bsd*
5535 Sequent family i[3456]86-sequent-sysv4*
5536 i[3456]86-sequent-sysv*
5537 i[3456]86-sequent-bsd*
5538 SPARC running LynxOS sparc-*-lynxos*
5539 SPARC running SunOS 4 sparc-*-sunos4*
5540 Tsqware Sparclet sparclet-*-*
5541 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5543 *** Changes in GDB 6.0:
5547 Support for debugging the Objective-C programming language has been
5548 integrated into GDB.
5550 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5552 DWARF 2's Call Frame Information makes available compiler generated
5553 information that more exactly describes the program's run-time stack.
5554 By using this information, GDB is able to provide more robust stack
5557 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5558 have been updated to use a new backtrace mechanism which includes
5559 DWARF 2 CFI support.
5563 GDB's remote protocol has been extended to include support for hosted
5564 file I/O (where the remote target uses GDB's file system). See GDB's
5565 remote protocol documentation for details.
5567 * All targets using the new architecture framework.
5569 All of GDB's targets have been updated to use the new internal
5570 architecture framework. The way is now open for future GDB releases
5571 to include cross-architecture native debugging support (i386 on amd64,
5574 * GNU/Linux's Thread Local Storage (TLS)
5576 GDB now includes support for for the GNU/Linux implementation of
5577 per-thread variables.
5579 * GNU/Linux's Native POSIX Thread Library (NPTL)
5581 GDB's thread code has been updated to work with either the new
5582 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5584 * Separate debug info.
5586 GDB, in conjunction with BINUTILS, now supports a mechanism for
5587 automatically loading debug information from a separate file. Instead
5588 of shipping full debug and non-debug versions of system libraries,
5589 system integrators can now instead ship just the stripped libraries
5590 and optional debug files.
5592 * DWARF 2 Location Expressions
5594 DWARF 2 Location Expressions allow the compiler to more completely
5595 describe the location of variables (even in optimized code) to the
5598 GDB now includes preliminary support for location expressions (support
5599 for DW_OP_piece is still missing).
5603 A number of long standing bugs that caused GDB to die while starting a
5604 Java application have been fixed. GDB's Java support is now
5605 considered "useable".
5607 * GNU/Linux support for fork, vfork, and exec.
5609 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5610 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5613 * GDB supports logging output to a file
5615 There are two new commands, "set logging" and "show logging", which can be
5616 used to capture GDB's output to a file.
5618 * The meaning of "detach" has changed for gdbserver
5620 The "detach" command will now resume the application, as documented. To
5621 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5624 * d10v, m68hc11 `regs' command deprecated
5626 The `info registers' command has been updated so that it displays the
5627 registers using a format identical to the old `regs' command.
5631 A new command, "maint set profile on/off", has been added. This command can
5632 be used to enable or disable profiling while running GDB, to profile a
5633 session or a set of commands. In addition there is a new configure switch,
5634 "--enable-profiling", which will cause GDB to be compiled with profiling
5635 data, for more informative profiling results.
5637 * Default MI syntax changed to "mi2".
5639 The default MI (machine interface) syntax, enabled by the command line
5640 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5641 "mi1", can be enabled by specifying the option "-i=mi1".
5643 Support for the original "mi0" syntax (included in GDB 5.0) has been
5646 Fix for gdb/192: removed extraneous space when displaying frame level.
5647 Fix for gdb/672: update changelist is now output in mi list format.
5648 Fix for gdb/702: a -var-assign that updates the value now shows up
5649 in a subsequent -var-update.
5651 * New native configurations.
5653 FreeBSD/amd64 x86_64-*-freebsd*
5655 * Multi-arched targets.
5657 HP/PA HPUX11 hppa*-*-hpux*
5658 Renesas M32R/D w/simulator m32r-*-elf*
5660 * OBSOLETE configurations and files
5662 Configurations that have been declared obsolete in this release have
5663 been commented out. Unless there is activity to revive these
5664 configurations, the next release of GDB will have their sources
5665 permanently REMOVED.
5667 Z8000 simulator z8k-zilog-none or z8ksim
5668 Matsushita MN10200 w/simulator mn10200-*-*
5669 H8/500 simulator h8500-hitachi-hms or h8500hms
5670 HP/PA running BSD hppa*-*-bsd*
5671 HP/PA running OSF/1 hppa*-*-osf*
5672 HP/PA Pro target hppa*-*-pro*
5673 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5674 Sequent family i[3456]86-sequent-sysv4*
5675 i[3456]86-sequent-sysv*
5676 i[3456]86-sequent-bsd*
5677 Tsqware Sparclet sparclet-*-*
5678 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5680 * REMOVED configurations and files
5683 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5684 IBM AIX PS/2 i[3456]86-*-aix
5685 i386 running Mach 3.0 i[3456]86-*-mach3*
5686 i386 running Mach i[3456]86-*-mach*
5687 i386 running OSF/1 i[3456]86-*osf1mk*
5688 HP/Apollo 68k Family m68*-apollo*-sysv*,
5690 m68*-hp-bsd*, m68*-hp-hpux*
5691 Argonaut Risc Chip (ARC) arc-*-*
5692 Mitsubishi D30V d30v-*-*
5693 Fujitsu FR30 fr30-*-elf*
5694 OS/9000 i[34]86-*-os9k
5695 I960 with MON960 i960-*-coff
5697 * MIPS $fp behavior changed
5699 The convenience variable $fp, for the MIPS, now consistently returns
5700 the address of the current frame's base. Previously, depending on the
5701 context, $fp could refer to either $sp or the current frame's base
5702 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5703 The GNU Source-Level Debugger''.
5705 *** Changes in GDB 5.3:
5707 * GNU/Linux shared library multi-threaded performance improved.
5709 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5710 `/proc', in preference to `ptrace' for memory reads. This may result
5711 in an improvement in the start-up time of multi-threaded, shared
5712 library applications when run under GDB. One GDB user writes: ``loads
5713 shared libs like mad''.
5715 * ``gdbserver'' now supports multi-threaded applications on some targets
5717 Support for debugging multi-threaded applications which use
5718 the GNU/Linux LinuxThreads package has been added for
5719 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5720 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5722 * GDB now supports C/C++ preprocessor macros.
5724 GDB now expands preprocessor macro invocations in C/C++ expressions,
5725 and provides various commands for showing macro definitions and how
5728 The new command `macro expand EXPRESSION' expands any macro
5729 invocations in expression, and shows the result.
5731 The new command `show macro MACRO-NAME' shows the definition of the
5732 macro named MACRO-NAME, and where it was defined.
5734 Most compilers don't include information about macros in the debugging
5735 information by default. In GCC 3.1, for example, you need to compile
5736 your program with the options `-gdwarf-2 -g3'. If the macro
5737 information is present in the executable, GDB will read it.
5739 * Multi-arched targets.
5741 DEC Alpha (partial) alpha*-*-*
5742 DEC VAX (partial) vax-*-*
5744 National Semiconductor NS32000 (partial) ns32k-*-*
5745 Motorola 68000 (partial) m68k-*-*
5746 Motorola MCORE mcore-*-*
5750 Fujitsu FRV architecture added by Red Hat frv*-*-*
5753 * New native configurations
5755 Alpha NetBSD alpha*-*-netbsd*
5756 SH NetBSD sh*-*-netbsdelf*
5757 MIPS NetBSD mips*-*-netbsd*
5758 UltraSPARC NetBSD sparc64-*-netbsd*
5760 * OBSOLETE configurations and files
5762 Configurations that have been declared obsolete in this release have
5763 been commented out. Unless there is activity to revive these
5764 configurations, the next release of GDB will have their sources
5765 permanently REMOVED.
5767 Mitsubishi D30V d30v-*-*
5768 OS/9000 i[34]86-*-os9k
5769 IBM AIX PS/2 i[3456]86-*-aix
5770 Fujitsu FR30 fr30-*-elf*
5771 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5772 Argonaut Risc Chip (ARC) arc-*-*
5773 i386 running Mach 3.0 i[3456]86-*-mach3*
5774 i386 running Mach i[3456]86-*-mach*
5775 i386 running OSF/1 i[3456]86-*osf1mk*
5776 HP/Apollo 68k Family m68*-apollo*-sysv*,
5778 m68*-hp-bsd*, m68*-hp-hpux*
5779 I960 with MON960 i960-*-coff
5781 * OBSOLETE languages
5783 CHILL, a Pascal like language used by telecommunications companies.
5785 * REMOVED configurations and files
5787 AMD 29k family via UDI a29k-amd-udi, udi29k
5788 A29K VxWorks a29k-*-vxworks
5789 AMD 29000 embedded, using EBMON a29k-none-none
5790 AMD 29000 embedded with COFF a29k-none-coff
5791 AMD 29000 embedded with a.out a29k-none-aout
5793 testsuite/gdb.hp/gdb.threads-hp/ directory
5795 * New command "set max-user-call-depth <nnn>"
5797 This command allows the user to limit the call depth of user-defined
5798 commands. The default is 1024.
5800 * Changes in FreeBSD/i386 native debugging.
5802 Support for the "generate-core-file" has been added.
5804 * New commands "dump", "append", and "restore".
5806 These commands allow data to be copied from target memory
5807 to a bfd-format or binary file (dump and append), and back
5808 from a file into memory (restore).
5810 * Improved "next/step" support on multi-processor Alpha Tru64.
5812 The previous single-step mechanism could cause unpredictable problems,
5813 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5814 of a software single-step mechanism prevents this.
5816 *** Changes in GDB 5.2.1:
5824 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5825 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5826 Fix, by Joel Brobecker imported from mainline.
5828 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5829 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5830 Fix, by Fred Fish, imported from mainline.
5832 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5833 Surprisingly enough, it works now.
5834 By Michal Ludvig, imported from mainline.
5836 i386 hardware watchpoint support:
5837 avoid misses on second run for some targets.
5838 By Pierre Muller, imported from mainline.
5840 *** Changes in GDB 5.2:
5842 * New command "set trust-readonly-sections on[off]".
5844 This command is a hint that tells gdb that read-only sections
5845 really are read-only (ie. that their contents will not change).
5846 In this mode, gdb will go to the object file rather than the
5847 target to read memory from read-only sections (such as ".text").
5848 This can be a significant performance improvement on some
5849 (notably embedded) targets.
5851 * New command "generate-core-file" (or "gcore").
5853 This new gdb command allows the user to drop a core file of the child
5854 process state at any time. So far it's been implemented only for
5855 GNU/Linux and Solaris, but should be relatively easily ported to other
5856 hosts. Argument is core file name (defaults to core.<pid>).
5858 * New command line option
5860 GDB now accepts --pid or -p followed by a process id.
5862 * Change in command line behavior -- corefiles vs. process ids.
5864 There is a subtle behavior in the way in which GDB handles
5865 command line arguments. The first non-flag argument is always
5866 a program to debug, but the second non-flag argument may either
5867 be a corefile or a process id. Previously, GDB would attempt to
5868 open the second argument as a corefile, and if that failed, would
5869 issue a superfluous error message and then attempt to attach it as
5870 a process. Now, if the second argument begins with a non-digit,
5871 it will be treated as a corefile. If it begins with a digit,
5872 GDB will attempt to attach it as a process, and if no such process
5873 is found, will then attempt to open it as a corefile.
5875 * Changes in ARM configurations.
5877 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5878 configuration is fully multi-arch.
5880 * New native configurations
5882 ARM NetBSD arm*-*-netbsd*
5883 x86 OpenBSD i[3456]86-*-openbsd*
5884 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5885 Sparc64 running FreeBSD sparc64-*-freebsd*
5889 Sanyo XStormy16 xstormy16-elf
5891 * OBSOLETE configurations and files
5893 Configurations that have been declared obsolete in this release have
5894 been commented out. Unless there is activity to revive these
5895 configurations, the next release of GDB will have their sources
5896 permanently REMOVED.
5898 AMD 29k family via UDI a29k-amd-udi, udi29k
5899 A29K VxWorks a29k-*-vxworks
5900 AMD 29000 embedded, using EBMON a29k-none-none
5901 AMD 29000 embedded with COFF a29k-none-coff
5902 AMD 29000 embedded with a.out a29k-none-aout
5904 testsuite/gdb.hp/gdb.threads-hp/ directory
5906 * REMOVED configurations and files
5908 TI TMS320C80 tic80-*-*
5910 PowerPC Solaris powerpcle-*-solaris*
5911 PowerPC Windows NT powerpcle-*-cygwin32
5912 PowerPC Netware powerpc-*-netware*
5913 Harris/CXUX m88k m88*-harris-cxux*
5914 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5915 ns32k-utek-sysv* ns32k-utek-*
5916 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5917 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5918 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5919 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5920 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5922 * Changes to command line processing
5924 The new `--args' feature can be used to specify command-line arguments
5925 for the inferior from gdb's command line.
5927 * Changes to key bindings
5929 There is a new `operate-and-get-next' function bound to `C-o'.
5931 *** Changes in GDB 5.1.1
5933 Fix compile problem on DJGPP.
5935 Fix a problem with floating-point registers on the i386 being
5938 Fix to stop GDB crashing on .debug_str debug info.
5940 Numerous documentation fixes.
5942 Numerous testsuite fixes.
5944 *** Changes in GDB 5.1:
5946 * New native configurations
5948 Alpha FreeBSD alpha*-*-freebsd*
5949 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5950 MIPS GNU/Linux mips*-*-linux*
5951 MIPS SGI Irix 6.x mips*-sgi-irix6*
5952 ia64 AIX ia64-*-aix*
5953 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5957 Motorola 68HC11 and 68HC12 m68hc11-elf
5959 UltraSparc running GNU/Linux sparc64-*-linux*
5961 * OBSOLETE configurations and files
5963 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5964 Harris/CXUX m88k m88*-harris-cxux*
5965 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5966 ns32k-utek-sysv* ns32k-utek-*
5967 TI TMS320C80 tic80-*-*
5969 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5970 PowerPC Solaris powerpcle-*-solaris*
5971 PowerPC Windows NT powerpcle-*-cygwin32
5972 PowerPC Netware powerpc-*-netware*
5973 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5974 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5975 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5976 Apple Macintosh (MPW) host N/A
5978 stuff.c (Program to stuff files into a specially prepared space in kdb)
5979 kdb-start.c (Main loop for the standalone kernel debugger)
5981 Configurations that have been declared obsolete in this release have
5982 been commented out. Unless there is activity to revive these
5983 configurations, the next release of GDB will have their sources
5984 permanently REMOVED.
5986 * REMOVED configurations and files
5988 Altos 3068 m68*-altos-*
5989 Convex c1-*-*, c2-*-*
5991 ARM RISCix arm-*-* (as host)
5995 * GDB has been converted to ISO C.
5997 GDB's source code has been converted to ISO C. In particular, the
5998 sources are fully protoized, and rely on standard headers being
6003 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6005 * The MI enabled by default.
6007 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6008 revised and enabled by default. Packages which use GDB as a debugging
6009 engine behind a UI or another front end are encouraged to switch to
6010 using the GDB/MI interface, instead of the old annotations interface
6011 which is now deprecated.
6013 * Support for debugging Pascal programs.
6015 GDB now includes support for debugging Pascal programs. The following
6016 main features are supported:
6018 - Pascal-specific data types such as sets;
6020 - automatic recognition of Pascal sources based on file-name
6023 - Pascal-style display of data types, variables, and functions;
6025 - a Pascal expression parser.
6027 However, some important features are not yet supported.
6029 - Pascal string operations are not supported at all;
6031 - there are some problems with boolean types;
6033 - Pascal type hexadecimal constants are not supported
6034 because they conflict with the internal variables format;
6036 - support for Pascal objects and classes is not full yet;
6038 - unlike Pascal, GDB is case-sensitive for symbol names.
6040 * Changes in completion.
6042 Commands such as `shell', `run' and `set args', which pass arguments
6043 to inferior programs, now complete on file names, similar to what
6044 users expect at the shell prompt.
6046 Commands which accept locations, such as `disassemble', `print',
6047 `breakpoint', `until', etc. now complete on filenames as well as
6048 program symbols. Thus, if you type "break foob TAB", and the source
6049 files linked into the programs include `foobar.c', that file name will
6050 be one of the candidates for completion. However, file names are not
6051 considered for completion after you typed a colon that delimits a file
6052 name from a name of a function in that file, as in "break foo.c:bar".
6054 `set demangle-style' completes on available demangling styles.
6056 * New platform-independent commands:
6058 It is now possible to define a post-hook for a command as well as a
6059 hook that runs before the command. For more details, see the
6060 documentation of `hookpost' in the GDB manual.
6062 * Changes in GNU/Linux native debugging.
6064 Support for debugging multi-threaded programs has been completely
6065 revised for all platforms except m68k and sparc. You can now debug as
6066 many threads as your system allows you to have.
6068 Attach/detach is supported for multi-threaded programs.
6070 Support for SSE registers was added for x86. This doesn't work for
6071 multi-threaded programs though.
6073 * Changes in MIPS configurations.
6075 Multi-arch support is enabled for all MIPS configurations.
6077 GDB can now be built as native debugger on SGI Irix 6.x systems for
6078 debugging n32 executables. (Debugging 64-bit executables is not yet
6081 * Unified support for hardware watchpoints in all x86 configurations.
6083 Most (if not all) native x86 configurations support hardware-assisted
6084 breakpoints and watchpoints in a unified manner. This support
6085 implements debug register sharing between watchpoints, which allows to
6086 put a virtually infinite number of watchpoints on the same address,
6087 and also supports watching regions up to 16 bytes with several debug
6090 The new maintenance command `maintenance show-debug-regs' toggles
6091 debugging print-outs in functions that insert, remove, and test
6092 watchpoints and hardware breakpoints.
6094 * Changes in the DJGPP native configuration.
6096 New command ``info dos sysinfo'' displays assorted information about
6097 the CPU, OS, memory, and DPMI server.
6099 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6100 display information about segment descriptors stored in GDT, LDT, and
6103 New commands ``info dos pde'' and ``info dos pte'' display entries
6104 from Page Directory and Page Tables (for now works with CWSDPMI only).
6105 New command ``info dos address-pte'' displays the Page Table entry for
6106 a given linear address.
6108 GDB can now pass command lines longer than 126 characters to the
6109 program being debugged (requires an update to the libdbg.a library
6110 which is part of the DJGPP development kit).
6112 DWARF2 debug info is now supported.
6114 It is now possible to `step' and `next' through calls to `longjmp'.
6116 * Changes in documentation.
6118 All GDB documentation was converted to GFDL, the GNU Free
6119 Documentation License.
6121 Tracepoints-related commands are now fully documented in the GDB
6124 TUI, the Text-mode User Interface, is now documented in the manual.
6126 Tracepoints-related commands are now fully documented in the GDB
6129 The "GDB Internals" manual now has an index. It also includes
6130 documentation of `ui_out' functions, GDB coding standards, x86
6131 hardware watchpoints, and memory region attributes.
6133 * GDB's version number moved to ``version.in''
6135 The Makefile variable VERSION has been replaced by the file
6136 ``version.in''. People creating GDB distributions should update the
6137 contents of this file.
6141 GUD support is now a standard part of the EMACS distribution.
6143 *** Changes in GDB 5.0:
6145 * Improved support for debugging FP programs on x86 targets
6147 Unified and much-improved support for debugging floating-point
6148 programs on all x86 targets. In particular, ``info float'' now
6149 displays the FP registers in the same format on all x86 targets, with
6150 greater level of detail.
6152 * Improvements and bugfixes in hardware-assisted watchpoints
6154 It is now possible to watch array elements, struct members, and
6155 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6156 on x86 targets no longer erroneously trigger when the address is
6159 * Improvements in the native DJGPP version of GDB
6161 The distribution now includes all the scripts and auxiliary files
6162 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6163 machines ``out of the box''.
6165 The DJGPP version can now debug programs that use signals. It is
6166 possible to catch signals that happened in the debuggee, deliver
6167 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6168 would kill the program being debugged.) Programs that hook hardware
6169 interrupts (keyboard, timer, etc.) can also be debugged.
6171 It is now possible to debug DJGPP programs that redirect their
6172 standard handles or switch them to raw (as opposed to cooked) mode, or
6173 even close them. The command ``run < foo > bar'' works as expected,
6174 and ``info terminal'' reports useful information about the debuggee's
6175 terminal, including raw/cooked mode, redirection, etc.
6177 The DJGPP version now uses termios functions for console I/O, which
6178 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6181 DOS-style file names with drive letters are now fully supported by
6184 It is now possible to debug DJGPP programs that switch their working
6185 directory. It is also possible to rerun the debuggee any number of
6186 times without restarting GDB; thus, you can use the same setup,
6187 breakpoints, etc. for many debugging sessions.
6189 * New native configurations
6191 ARM GNU/Linux arm*-*-linux*
6192 PowerPC GNU/Linux powerpc-*-linux*
6196 Motorola MCore mcore-*-*
6197 x86 VxWorks i[3456]86-*-vxworks*
6198 PowerPC VxWorks powerpc-*-vxworks*
6199 TI TMS320C80 tic80-*-*
6201 * OBSOLETE configurations
6203 Altos 3068 m68*-altos-*
6204 Convex c1-*-*, c2-*-*
6206 ARM RISCix arm-*-* (as host)
6209 Configurations that have been declared obsolete will be commented out,
6210 but the code will be left in place. If there is no activity to revive
6211 these configurations before the next release of GDB, the sources will
6212 be permanently REMOVED.
6214 * Gould support removed
6216 Support for the Gould PowerNode and NP1 has been removed.
6218 * New features for SVR4
6220 On SVR4 native platforms (such as Solaris), if you attach to a process
6221 without first loading a symbol file, GDB will now attempt to locate and
6222 load symbols from the running process's executable file.
6224 * Many C++ enhancements
6226 C++ support has been greatly improved. Overload resolution now works properly
6227 in almost all cases. RTTI support is on the way.
6229 * Remote targets can connect to a sub-program
6231 A popen(3) style serial-device has been added. This device starts a
6232 sub-process (such as a stand-alone simulator) and then communicates
6233 with that. The sub-program to run is specified using the syntax
6234 ``|<program> <args>'' vis:
6236 (gdb) set remotedebug 1
6237 (gdb) target extended-remote |mn10300-elf-sim program-args
6239 * MIPS 64 remote protocol
6241 A long standing bug in the mips64 remote protocol where by GDB
6242 expected certain 32 bit registers (ex SR) to be transfered as 32
6243 instead of 64 bits has been fixed.
6245 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6246 added to provide backward compatibility with older versions of GDB.
6248 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6250 The command ``set remotebinarydownload'' command has been replaced by
6251 ``set remote X-packet''. Other commands in ``set remote'' family
6252 include ``set remote P-packet''.
6254 * Breakpoint commands accept ranges.
6256 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6257 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6258 ``tracepoint passcount'' also accepts a range of tracepoints.
6260 * ``apropos'' command added.
6262 The ``apropos'' command searches through command names and
6263 documentation strings, printing out matches, making it much easier to
6264 try to find a command that does what you are looking for.
6268 A new machine oriented interface (MI) has been added to GDB. This
6269 interface is designed for debug environments running GDB as a separate
6270 process. This is part of the long term libGDB project. See the
6271 "GDB/MI" chapter of the GDB manual for further information. It can be
6272 enabled by configuring with:
6274 .../configure --enable-gdbmi
6276 *** Changes in GDB-4.18:
6278 * New native configurations
6280 HP-UX 10.20 hppa*-*-hpux10.20
6281 HP-UX 11.x hppa*-*-hpux11.0*
6282 M68K GNU/Linux m68*-*-linux*
6286 Fujitsu FR30 fr30-*-elf*
6287 Intel StrongARM strongarm-*-*
6288 Mitsubishi D30V d30v-*-*
6290 * OBSOLETE configurations
6292 Gould PowerNode, NP1 np1-*-*, pn-*-*
6294 Configurations that have been declared obsolete will be commented out,
6295 but the code will be left in place. If there is no activity to revive
6296 these configurations before the next release of GDB, the sources will
6297 be permanently REMOVED.
6301 As a compatibility experiment, GDB's source files buildsym.h and
6302 buildsym.c have been converted to pure standard C, no longer
6303 containing any K&R compatibility code. We believe that all systems in
6304 use today either come with a standard C compiler, or have a GCC port
6305 available. If this is not true, please report the affected
6306 configuration to bug-gdb@gnu.org immediately. See the README file for
6307 information about getting a standard C compiler if you don't have one
6312 GDB now uses readline 2.2.
6314 * set extension-language
6316 You can now control the mapping between filename extensions and source
6317 languages by using the `set extension-language' command. For instance,
6318 you can ask GDB to treat .c files as C++ by saying
6319 set extension-language .c c++
6320 The command `info extensions' lists all of the recognized extensions
6321 and their associated languages.
6323 * Setting processor type for PowerPC and RS/6000
6325 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6326 you can use the `set processor' command to specify what variant of the
6327 PowerPC family you are debugging. The command
6331 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6332 following PowerPC and RS6000 variants:
6334 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6335 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6337 403GC IBM PowerPC 403GC
6338 505 Motorola PowerPC 505
6339 860 Motorola PowerPC 860 or 850
6340 601 Motorola PowerPC 601
6341 602 Motorola PowerPC 602
6342 603 Motorola/IBM PowerPC 603 or 603e
6343 604 Motorola PowerPC 604 or 604e
6344 750 Motorola/IBM PowerPC 750 or 750
6346 At the moment, this command just tells GDB what to name the
6347 special-purpose processor registers. Since almost all the affected
6348 registers are inaccessible to user-level programs, this command is
6349 only useful for remote debugging in its present form.
6353 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6354 more extensive support for HP-UX. Added features include shared
6355 library support, kernel threads and hardware watchpoints for 11.00,
6356 support for HP's ANSI C and C++ compilers, and a compatibility mode
6357 for xdb and dbx commands.
6361 HP's donation includes the new concept of catchpoints, which is a
6362 generalization of the old catch command. On HP-UX, it is now possible
6363 to catch exec, fork, and vfork, as well as library loading.
6365 This means that the existing catch command has changed; its first
6366 argument now specifies the type of catch to be set up. See the
6367 output of "help catch" for a list of catchpoint types.
6369 * Debugging across forks
6371 On HP-UX, you can choose which process to debug when a fork() happens
6376 HP has donated a curses-based terminal user interface (TUI). To get
6377 it, build with --enable-tui. Although this can be enabled for any
6378 configuration, at present it only works for native HP debugging.
6380 * GDB remote protocol additions
6382 A new protocol packet 'X' that writes binary data is now available.
6383 Default behavior is to try 'X', then drop back to 'M' if the stub
6384 fails to respond. The settable variable `remotebinarydownload'
6385 allows explicit control over the use of 'X'.
6387 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6388 full 64-bit address. The command
6390 set remoteaddresssize 32
6392 can be used to revert to the old behaviour. For existing remote stubs
6393 the change should not be noticed, as the additional address information
6396 In order to assist in debugging stubs, you may use the maintenance
6397 command `packet' to send any text string to the stub. For instance,
6399 maint packet heythere
6401 sends the packet "$heythere#<checksum>". Note that it is very easy to
6402 disrupt a debugging session by sending the wrong packet at the wrong
6405 The compare-sections command allows you to compare section data on the
6406 target to what is in the executable file without uploading or
6407 downloading, by comparing CRC checksums.
6409 * Tracing can collect general expressions
6411 You may now collect general expressions at tracepoints. This requires
6412 further additions to the target-side stub; see tracepoint.c and
6413 doc/agentexpr.texi for further details.
6415 * mask-address variable for Mips
6417 For Mips targets, you may control the zeroing of the upper 32 bits of
6418 a 64-bit address by entering `set mask-address on'. This is mainly
6419 of interest to users of embedded R4xxx and R5xxx processors.
6421 * Higher serial baud rates
6423 GDB's serial code now allows you to specify baud rates 57600, 115200,
6424 230400, and 460800 baud. (Note that your host system may not be able
6425 to achieve all of these rates.)
6429 The i960 configuration now includes an initial implementation of a
6430 builtin simulator, contributed by Jim Wilson.
6433 *** Changes in GDB-4.17:
6435 * New native configurations
6437 Alpha GNU/Linux alpha*-*-linux*
6438 Unixware 2.x i[3456]86-unixware2*
6439 Irix 6.x mips*-sgi-irix6*
6440 PowerPC GNU/Linux powerpc-*-linux*
6441 PowerPC Solaris powerpcle-*-solaris*
6442 Sparc GNU/Linux sparc-*-linux*
6443 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6447 Argonaut Risc Chip (ARC) arc-*-*
6448 Hitachi H8/300S h8300*-*-*
6449 Matsushita MN10200 w/simulator mn10200-*-*
6450 Matsushita MN10300 w/simulator mn10300-*-*
6451 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6452 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6453 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6454 Mitsubishi D10V w/simulator d10v-*-*
6455 Mitsubishi M32R/D w/simulator m32r-*-elf*
6456 Tsqware Sparclet sparclet-*-*
6457 NEC V850 w/simulator v850-*-*
6459 * New debugging protocols
6461 ARM with RDI protocol arm*-*-*
6462 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6463 DDB and LSI variants of PMON protocol mips*-*-*
6464 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6465 PowerPC with SDS protocol powerpc{,le}-*-eabi
6466 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6470 All configurations can now understand and use the DWARF 2 debugging
6471 format. The choice is automatic, if the symbol file contains DWARF 2
6476 GDB now includes basic Java language support. This support is
6477 only useful with Java compilers that produce native machine code.
6479 * solib-absolute-prefix and solib-search-path
6481 For SunOS and SVR4 shared libraries, you may now set the prefix for
6482 loading absolute shared library symbol files, and the search path for
6483 locating non-absolute shared library symbol files.
6485 * Live range splitting
6487 GDB can now effectively debug code for which GCC has performed live
6488 range splitting as part of its optimization. See gdb/doc/LRS for
6489 more details on the expected format of the stabs information.
6493 GDB's support for the GNU Hurd, including thread debugging, has been
6494 updated to work with current versions of the Hurd.
6498 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6499 instruction set. ARM GDB automatically detects when Thumb
6500 instructions are in use, and adjusts disassembly and backtracing
6505 GDB's MIPS target configurations now handle the MIP16 16-bit
6510 GDB now includes support for overlays; if an executable has been
6511 linked such that multiple sections are based at the same address, GDB
6512 will decide which section to use for symbolic info. You can choose to
6513 control the decision manually, using overlay commands, or implement
6514 additional target-side support and use "overlay load-target" to bring
6515 in the overlay mapping. Do "help overlay" for more detail.
6519 The command "info symbol <address>" displays information about
6520 the symbol at the specified address.
6524 The standard remote protocol now includes an extension that allows
6525 asynchronous collection and display of trace data. This requires
6526 extensive support in the target-side debugging stub. Tracing mode
6527 includes a new interaction mode in GDB and new commands: see the
6528 file tracepoint.c for more details.
6532 Configurations for embedded MIPS now include a simulator contributed
6533 by Cygnus Solutions. The simulator supports the instruction sets
6534 of most MIPS variants.
6538 Sparc configurations may now include the ERC32 simulator contributed
6539 by the European Space Agency. The simulator is not built into
6540 Sparc targets by default; configure with --enable-sim to include it.
6544 For target configurations that may include multiple variants of a
6545 basic architecture (such as MIPS and SH), you may now set the
6546 architecture explicitly. "set arch" sets, "info arch" lists
6547 the possible architectures.
6549 *** Changes in GDB-4.16:
6551 * New native configurations
6553 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6554 M68K NetBSD m68k-*-netbsd*
6555 PowerPC AIX 4.x powerpc-*-aix*
6556 PowerPC MacOS powerpc-*-macos*
6557 PowerPC Windows NT powerpcle-*-cygwin32
6558 RS/6000 AIX 4.x rs6000-*-aix4*
6562 ARM with RDP protocol arm-*-*
6563 I960 with MON960 i960-*-coff
6564 MIPS VxWorks mips*-*-vxworks*
6565 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6566 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6568 Matra Sparclet sparclet-*-*
6572 The powerpc-eabi configuration now includes the PSIM simulator,
6573 contributed by Andrew Cagney, with assistance from Mike Meissner.
6574 PSIM is a very elaborate model of the PowerPC, including not only
6575 basic instruction set execution, but also details of execution unit
6576 performance and I/O hardware. See sim/ppc/README for more details.
6580 GDB now works with Solaris 2.5.
6582 * Windows 95/NT native
6584 GDB will now work as a native debugger on Windows 95 and Windows NT.
6585 To build it from source, you must use the "gnu-win32" environment,
6586 which uses a DLL to emulate enough of Unix to run the GNU tools.
6587 Further information, binaries, and sources are available at
6588 ftp.cygnus.com, under pub/gnu-win32.
6590 * dont-repeat command
6592 If a user-defined command includes the command `dont-repeat', then the
6593 command will not be repeated if the user just types return. This is
6594 useful if the command is time-consuming to run, so that accidental
6595 extra keystrokes don't run the same command many times.
6597 * Send break instead of ^C
6599 The standard remote protocol now includes an option to send a break
6600 rather than a ^C to the target in order to interrupt it. By default,
6601 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6603 * Remote protocol timeout
6605 The standard remote protocol includes a new variable `remotetimeout'
6606 that allows you to set the number of seconds before GDB gives up trying
6607 to read from the target. The default value is 2.
6609 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6611 By default GDB will automatically keep track of objects as they are
6612 loaded and unloaded by the dynamic linker. By using the command `set
6613 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6614 when shared library events occur, thus allowing you to set breakpoints
6615 in shared libraries which are explicitly loaded by the inferior.
6617 Note this feature does not work on hpux8. On hpux9 you must link
6618 /usr/lib/end.o into your program. This feature should work
6619 automatically on hpux10.
6621 * Irix 5.x hardware watchpoint support
6623 Irix 5 configurations now support the use of hardware watchpoints.
6625 * Mips protocol "SYN garbage limit"
6627 When debugging a Mips target using the `target mips' protocol, you
6628 may set the number of characters that GDB will ignore by setting
6629 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6630 every character. The default value is 1050.
6632 * Recording and replaying remote debug sessions
6634 If you set `remotelogfile' to the name of a file, gdb will write to it
6635 a recording of a remote debug session. This recording may then be
6636 replayed back to gdb using "gdbreplay". See gdbserver/README for
6637 details. This is useful when you have a problem with GDB while doing
6638 remote debugging; you can make a recording of the session and send it
6639 to someone else, who can then recreate the problem.
6641 * Speedups for remote debugging
6643 GDB includes speedups for downloading and stepping MIPS systems using
6644 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6645 and more efficient S-record downloading.
6647 * Memory use reductions and statistics collection
6649 GDB now uses less memory and reports statistics about memory usage.
6650 Try the `maint print statistics' command, for example.
6652 *** Changes in GDB-4.15:
6654 * Psymtabs for XCOFF
6656 The symbol reader for AIX GDB now uses partial symbol tables. This
6657 can greatly improve startup time, especially for large executables.
6659 * Remote targets use caching
6661 Remote targets now use a data cache to speed up communication with the
6662 remote side. The data cache could lead to incorrect results because
6663 it doesn't know about volatile variables, thus making it impossible to
6664 debug targets which use memory mapped I/O devices. `set remotecache
6665 off' turns the data cache off.
6667 * Remote targets may have threads
6669 The standard remote protocol now includes support for multiple threads
6670 in the target system, using new protocol commands 'H' and 'T'. See
6671 gdb/remote.c for details.
6675 If GDB is configured with `--enable-netrom', then it will include
6676 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6677 acts as though it is a bank of ROM on the target board, but you can
6678 write into it over the network. GDB's support consists only of
6679 support for fast loading into the emulated ROM; to debug, you must use
6680 another protocol, such as standard remote protocol. The usual
6681 sequence is something like
6683 target nrom <netrom-hostname>
6685 target remote <netrom-hostname>:1235
6689 GDB now includes support for the Apple Macintosh, as a host only. It
6690 may be run as either an MPW tool or as a standalone application, and
6691 it can debug through the serial port. All the usual GDB commands are
6692 available, but to the target command, you must supply "serial" as the
6693 device type instead of "/dev/ttyXX". See mpw-README in the main
6694 directory for more information on how to build. The MPW configuration
6695 scripts */mpw-config.in support only a few targets, and only the
6696 mips-idt-ecoff target has been tested.
6700 GDB configuration now uses autoconf. This is not user-visible,
6701 but does simplify configuration and building.
6705 GDB now supports hpux10.
6707 *** Changes in GDB-4.14:
6709 * New native configurations
6711 x86 FreeBSD i[345]86-*-freebsd
6712 x86 NetBSD i[345]86-*-netbsd
6713 NS32k NetBSD ns32k-*-netbsd
6714 Sparc NetBSD sparc-*-netbsd
6718 A29K VxWorks a29k-*-vxworks
6719 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6720 CPU32 EST-300 emulator m68*-*-est*
6721 PowerPC ELF powerpc-*-elf
6724 * Alpha OSF/1 support for procfs
6726 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6727 possible to attach to running processes. As the mounting of the /proc
6728 filesystem is optional on the Alpha, GDB automatically determines
6729 the availability of /proc during startup. This can lead to problems
6730 if /proc is unmounted after GDB has been started.
6732 * Arguments to user-defined commands
6734 User commands may accept up to 10 arguments separated by whitespace.
6735 Arguments are accessed within the user command via $arg0..$arg9. A
6738 print $arg0 + $arg1 + $arg2
6740 To execute the command use:
6743 Defines the command "adder" which prints the sum of its three arguments.
6744 Note the arguments are text substitutions, so they may reference variables,
6745 use complex expressions, or even perform inferior function calls.
6747 * New `if' and `while' commands
6749 This makes it possible to write more sophisticated user-defined
6750 commands. Both commands take a single argument, which is the
6751 expression to evaluate, and must be followed by the commands to
6752 execute, one per line, if the expression is nonzero, the list being
6753 terminated by the word `end'. The `if' command list may include an
6754 `else' word, which causes the following commands to be executed only
6755 if the expression is zero.
6757 * Fortran source language mode
6759 GDB now includes partial support for Fortran 77. It will recognize
6760 Fortran programs and can evaluate a subset of Fortran expressions, but
6761 variables and functions may not be handled correctly. GDB will work
6762 with G77, but does not yet know much about symbols emitted by other
6765 * Better HPUX support
6767 Most debugging facilities now work on dynamic executables for HPPAs
6768 running hpux9 or later. You can attach to running dynamically linked
6769 processes, but by default the dynamic libraries will be read-only, so
6770 for instance you won't be able to put breakpoints in them. To change
6771 that behavior do the following before running the program:
6777 This will cause the libraries to be mapped private and read-write.
6778 To revert to the normal behavior, do this:
6784 You cannot set breakpoints or examine data in the library until after
6785 the library is loaded if the function/data symbols do not have
6788 GDB can now also read debug symbols produced by the HP C compiler on
6789 HPPAs (sorry, no C++, Fortran or 68k support).
6791 * Target byte order now dynamically selectable
6793 You can choose which byte order to use with a target system, via the
6794 commands "set endian big" and "set endian little", and you can see the
6795 current setting by using "show endian". You can also give the command
6796 "set endian auto", in which case GDB will use the byte order
6797 associated with the executable. Currently, only embedded MIPS
6798 configurations support dynamic selection of target byte order.
6800 * New DOS host serial code
6802 This version uses DPMI interrupts to handle buffered I/O, so you
6803 no longer need to run asynctsr when debugging boards connected to
6806 *** Changes in GDB-4.13:
6808 * New "complete" command
6810 This lists all the possible completions for the rest of the line, if it
6811 were to be given as a command itself. This is intended for use by emacs.
6813 * Trailing space optional in prompt
6815 "set prompt" no longer adds a space for you after the prompt you set. This
6816 allows you to set a prompt which ends in a space or one that does not.
6818 * Breakpoint hit counts
6820 "info break" now displays a count of the number of times the breakpoint
6821 has been hit. This is especially useful in conjunction with "ignore"; you
6822 can ignore a large number of breakpoint hits, look at the breakpoint info
6823 to see how many times the breakpoint was hit, then run again, ignoring one
6824 less than that number, and this will get you quickly to the last hit of
6827 * Ability to stop printing at NULL character
6829 "set print null-stop" will cause GDB to stop printing the characters of
6830 an array when the first NULL is encountered. This is useful when large
6831 arrays actually contain only short strings.
6833 * Shared library breakpoints
6835 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6836 breakpoints in shared libraries before the executable is run.
6838 * Hardware watchpoints
6840 There is a new hardware breakpoint for the watch command for sparclite
6841 targets. See gdb/sparclite/hw_breakpoint.note.
6843 Hardware watchpoints are also now supported under GNU/Linux.
6847 Annotations have been added. These are for use with graphical interfaces,
6848 and are still experimental. Currently only gdba.el uses these.
6850 * Improved Irix 5 support
6852 GDB now works properly with Irix 5.2.
6854 * Improved HPPA support
6856 GDB now works properly with the latest GCC and GAS.
6858 * New native configurations
6860 Sequent PTX4 i[34]86-sequent-ptx4
6861 HPPA running OSF/1 hppa*-*-osf*
6862 Atari TT running SVR4 m68*-*-sysv4*
6863 RS/6000 LynxOS rs6000-*-lynxos*
6867 OS/9000 i[34]86-*-os9k
6868 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6871 * Hitachi SH7000 and E7000-PC ICE support
6873 There is now support for communicating with the Hitachi E7000-PC ICE.
6874 This is available automatically when GDB is configured for the SH.
6878 As usual, a variety of small fixes and improvements, both generic
6879 and configuration-specific. See the ChangeLog for more detail.
6881 *** Changes in GDB-4.12:
6883 * Irix 5 is now supported
6887 GDB-4.12 on the HPPA has a number of changes which make it unable
6888 to debug the output from the currently released versions of GCC and
6889 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6890 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6891 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6894 *** Changes in GDB-4.11:
6896 * User visible changes:
6900 The "set remotedebug" option is now consistent between the mips remote
6901 target, remote targets using the gdb-specific protocol, UDI (AMD's
6902 debug protocol for the 29k) and the 88k bug monitor. It is now an
6903 integer specifying a debug level (normally 0 or 1, but 2 means more
6904 debugging info for the mips target).
6906 * DEC Alpha native support
6908 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6909 debug info, but GDB works fairly well with the DEC compiler and should
6910 work with a future GCC release. See the README file for a few
6911 Alpha-specific notes.
6913 * Preliminary thread implementation
6915 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6917 * LynxOS native and target support for 386
6919 This release has been hosted on LynxOS 2.2, and also can be configured
6920 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6923 * Improvements in C++ mangling/demangling.
6925 This release has much better g++ debugging, specifically in name
6926 mangling/demangling, virtual function calls, print virtual table,
6927 call methods, ...etc.
6929 *** Changes in GDB-4.10:
6931 * User visible changes:
6933 Remote debugging using the GDB-specific (`target remote') protocol now
6934 supports the `load' command. This is only useful if you have some
6935 other way of getting the stub to the target system, and you can put it
6936 somewhere in memory where it won't get clobbered by the download.
6938 Filename completion now works.
6940 When run under emacs mode, the "info line" command now causes the
6941 arrow to point to the line specified. Also, "info line" prints
6942 addresses in symbolic form (as well as hex).
6944 All vxworks based targets now support a user settable option, called
6945 vxworks-timeout. This option represents the number of seconds gdb
6946 should wait for responses to rpc's. You might want to use this if
6947 your vxworks target is, perhaps, a slow software simulator or happens
6948 to be on the far side of a thin network line.
6952 This release contains support for using a DEC alpha as a GDB host for
6953 cross debugging. Native alpha debugging is not supported yet.
6956 *** Changes in GDB-4.9:
6960 This is the first GDB release which is accompanied by a matching testsuite.
6961 The testsuite requires installation of dejagnu, which should be available
6962 via ftp from most sites that carry GNU software.
6966 'Cfront' style demangling has had its name changed to 'ARM' style, to
6967 emphasize that it was written from the specifications in the C++ Annotated
6968 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6969 disclaimers, it still generated too much confusion with users attempting to
6970 use gdb with AT&T cfront.
6974 GDB now uses a standard remote interface to a simulator library.
6975 So far, the library contains simulators for the Zilog Z8001/2, the
6976 Hitachi H8/300, H8/500 and Super-H.
6978 * New targets supported
6980 H8/300 simulator h8300-hitachi-hms or h8300hms
6981 H8/500 simulator h8500-hitachi-hms or h8500hms
6982 SH simulator sh-hitachi-hms or sh
6983 Z8000 simulator z8k-zilog-none or z8ksim
6984 IDT MIPS board over serial line mips-idt-ecoff
6986 Cross-debugging to GO32 targets is supported. It requires a custom
6987 version of the i386-stub.c module which is integrated with the
6988 GO32 memory extender.
6990 * New remote protocols
6992 MIPS remote debugging protocol.
6994 * New source languages supported
6996 This version includes preliminary support for Chill, a Pascal like language
6997 used by telecommunications companies. Chill support is also being integrated
6998 into the GNU compiler, but we don't know when it will be publically available.
7001 *** Changes in GDB-4.8:
7003 * HP Precision Architecture supported
7005 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7006 version of this support was available as a set of patches from the
7007 University of Utah. GDB does not support debugging of programs
7008 compiled with the HP compiler, because HP will not document their file
7009 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7010 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7012 Many problems in the preliminary version have been fixed.
7014 * Faster and better demangling
7016 We have improved template demangling and fixed numerous bugs in the GNU style
7017 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7018 character types (wchar_t) are now supported. Demangling of each symbol is now
7019 only done once, and is cached when the symbol table for a file is read in.
7020 This results in a small increase in memory usage for C programs, a moderate
7021 increase in memory usage for C++ programs, and a fantastic speedup in
7024 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7025 from the specifications in the Annotated Reference Manual, which AT&T's
7026 compiler does not actually implement.
7028 * G++ multiple inheritance compiler problem
7030 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7031 inheritance lattices was reworked to properly discover ambiguities. We
7032 recently found an example which causes this new algorithm to fail in a
7033 very subtle way, producing bad debug information for those classes.
7034 The file 'gcc.patch' (in this directory) can be applied to gcc to
7035 circumvent the problem. A future GCC release will contain a complete
7038 The previous G++ debug info problem (mentioned below for the gdb-4.7
7039 release) is fixed in gcc version 2.3.2.
7041 * Improved configure script
7043 The `configure' script will now attempt to guess your system type if
7044 you don't supply a host system type. The old scheme of supplying a
7045 host system triplet is preferable over using this. All the magic is
7046 done in the new `config.guess' script. Examine it for details.
7048 We have also brought our configure script much more in line with the FSF's
7049 version. It now supports the --with-xxx options. In particular,
7050 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7051 The resulting GDB will not be able to read arbitrary object file formats --
7052 only the format ``expected'' to be used on the configured target system.
7053 We hope to make this the default in a future release.
7055 * Documentation improvements
7057 There's new internal documentation on how to modify GDB, and how to
7058 produce clean changes to the code. We implore people to read it
7059 before submitting changes.
7061 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7062 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7063 `info' files are also provided. To build `info' files from scratch,
7064 you will need the latest `makeinfo' release, which will be available in
7065 a future texinfo-X.Y release.
7067 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7068 We're not sure exactly which versions have this problem, but it has
7069 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7070 or better. If that isn't possible, there is a patch in
7071 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7072 around this problem.
7076 GDB now supports array constants that can be used in expressions typed in by
7077 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7078 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7081 The new directory `gdb/sparclite' contains a program that demonstrates
7082 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7084 * New native hosts supported
7086 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7087 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7089 * New targets supported
7091 AMD 29k family via UDI a29k-amd-udi or udi29k
7093 * New file formats supported
7095 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7096 HPUX core files, and SCO 3.2v2 core files.
7100 Attaching to processes now works again; thanks for the many bug reports.
7102 We have also stomped on a bunch of core dumps caused by
7103 printf_filtered("%s") problems.
7105 We eliminated a copyright problem on the rpc and ptrace header files
7106 for VxWorks, which was discovered at the last minute during the 4.7
7107 release. You should now be able to build a VxWorks GDB.
7109 You can now interrupt gdb while an attached process is running. This
7110 will cause the attached process to stop, and give control back to GDB.
7112 We fixed problems caused by using too many file descriptors
7113 for reading symbols from object files and libraries. This was
7114 especially a problem for programs that used many (~100) shared
7117 The `step' command now only enters a subroutine if there is line number
7118 information for the subroutine. Otherwise it acts like the `next'
7119 command. Previously, `step' would enter subroutines if there was
7120 any debugging information about the routine. This avoids problems
7121 when using `cc -g1' on MIPS machines.
7123 * Internal improvements
7125 GDB's internal interfaces have been improved to make it easier to support
7126 debugging of multiple languages in the future.
7128 GDB now uses a common structure for symbol information internally.
7129 Minimal symbols (derived from linkage symbols in object files), partial
7130 symbols (from a quick scan of debug information), and full symbols
7131 contain a common subset of information, making it easier to write
7132 shared code that handles any of them.
7134 * New command line options
7136 We now accept --silent as an alias for --quiet.
7140 The memory-mapped-malloc library is now licensed under the GNU Library
7141 General Public License.
7143 *** Changes in GDB-4.7:
7145 * Host/native/target split
7147 GDB has had some major internal surgery to untangle the support for
7148 hosts and remote targets. Now, when you configure GDB for a remote
7149 target, it will no longer load in all of the support for debugging
7150 local programs on the host. When fully completed and tested, this will
7151 ensure that arbitrary host/target combinations are possible.
7153 The primary conceptual shift is to separate the non-portable code in
7154 GDB into three categories. Host specific code is required any time GDB
7155 is compiled on that host, regardless of the target. Target specific
7156 code relates to the peculiarities of the target, but can be compiled on
7157 any host. Native specific code is everything else: it can only be
7158 built when the host and target are the same system. Child process
7159 handling and core file support are two common `native' examples.
7161 GDB's use of /proc for controlling Unix child processes is now cleaner.
7162 It has been split out into a single module under the `target_ops' vector,
7163 plus two native-dependent functions for each system that uses /proc.
7165 * New hosts supported
7167 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7168 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7169 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7171 * New targets supported
7173 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7174 68030 and CPU32 m68030-*-*, m68332-*-*
7176 * New native hosts supported
7178 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7179 (386bsd is not well tested yet)
7180 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7182 * New file formats supported
7184 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7185 supports reading of `a.out.adobe' object files, which are an a.out
7186 format extended with minimal information about multiple sections.
7190 `show copying' is the same as the old `info copying'.
7191 `show warranty' is the same as `info warrantee'.
7192 These were renamed for consistency. The old commands continue to work.
7194 `info handle' is a new alias for `info signals'.
7196 You can now define pre-command hooks, which attach arbitrary command
7197 scripts to any command. The commands in the hook will be executed
7198 prior to the user's command. You can also create a hook which will be
7199 executed whenever the program stops. See gdb.texinfo.
7203 We now deal with Cfront style name mangling, and can even extract type
7204 info from mangled symbols. GDB can automatically figure out which
7205 symbol mangling style your C++ compiler uses.
7207 Calling of methods and virtual functions has been improved as well.
7211 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7212 fixed. This was due to mishandling of the extra N_SO stabs output
7215 We also finally got Ultrix 4.2 running in house, and fixed core file
7216 support, with help from a dozen people on the net.
7218 John M. Farrell discovered that the reason that single-stepping was so
7219 slow on all of the Mips based platforms (primarily SGI and DEC) was
7220 that we were trying to demangle and lookup a symbol used for internal
7221 purposes on every instruction that was being stepped through. Changing
7222 the name of that symbol so that it couldn't be mistaken for a C++
7223 mangled symbol sped things up a great deal.
7225 Rich Pixley sped up symbol lookups in general by getting much smarter
7226 about when C++ symbol mangling is necessary. This should make symbol
7227 completion (TAB on the command line) much faster. It's not as fast as
7228 we'd like, but it's significantly faster than gdb-4.6.
7232 A new user controllable variable 'call_scratch_address' can
7233 specify the location of a scratch area to be used when GDB
7234 calls a function in the target. This is necessary because the
7235 usual method of putting the scratch area on the stack does not work
7236 in systems that have separate instruction and data spaces.
7238 We integrated changes to support the 29k UDI (Universal Debugger
7239 Interface), but discovered at the last minute that we didn't have all
7240 of the appropriate copyright paperwork. We are working with AMD to
7241 resolve this, and hope to have it available soon.
7245 We have sped up the remote serial line protocol, especially for targets
7246 with lots of registers. It now supports a new `expedited status' ('T')
7247 message which can be used in place of the existing 'S' status message.
7248 This allows the remote stub to send only the registers that GDB
7249 needs to make a quick decision about single-stepping or conditional
7250 breakpoints, eliminating the need to fetch the entire register set for
7251 each instruction being stepped through.
7253 The GDB remote serial protocol now implements a write-through cache for
7254 registers, only re-reading the registers if the target has run.
7256 There is also a new remote serial stub for SPARC processors. You can
7257 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7258 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7259 processor with a serial port.
7263 Configure.in files have become much easier to read and modify. A new
7264 `table driven' format makes it more obvious what configurations are
7265 supported, and what files each one uses.
7269 There is a new opcodes library which will eventually contain all of the
7270 disassembly routines and opcode tables. At present, it only contains
7271 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7272 disassembler (binutils/objdump) to share these routines.
7274 The libiberty library is now copylefted under the GNU Library General
7275 Public License. This allows more liberal use, and was done so libg++
7276 can use it. This makes no difference to GDB, since the Library License
7277 grants all the rights from the General Public License.
7281 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7282 reference to the stabs symbol info used by the debugger. It is (as far
7283 as we know) the only published document on this fascinating topic. We
7284 encourage you to read it, compare it to the stabs information on your
7285 system, and send improvements on the document in general (to
7286 bug-gdb@prep.ai.mit.edu).
7288 And, of course, many bugs have been fixed.
7291 *** Changes in GDB-4.6:
7293 * Better support for C++ function names
7295 GDB now accepts as input the "demangled form" of C++ overloaded function
7296 names and member function names, and can do command completion on such names
7297 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7298 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7299 Make use of command completion, it is your friend.
7301 GDB also now accepts a variety of C++ mangled symbol formats. They are
7302 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7303 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7304 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7305 for the list of formats.
7307 * G++ symbol mangling problem
7309 Recent versions of gcc have a bug in how they emit debugging information for
7310 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7311 directory) can be applied to gcc to fix the problem. Alternatively, if you
7312 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7313 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7314 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7317 * New 'maintenance' command
7319 All of the commands related to hacking GDB internals have been moved out of
7320 the main command set, and now live behind the 'maintenance' command. This
7321 can also be abbreviated as 'mt'. The following changes were made:
7323 dump-me -> maintenance dump-me
7324 info all-breakpoints -> maintenance info breakpoints
7325 printmsyms -> maintenance print msyms
7326 printobjfiles -> maintenance print objfiles
7327 printpsyms -> maintenance print psymbols
7328 printsyms -> maintenance print symbols
7330 The following commands are new:
7332 maintenance demangle Call internal GDB demangler routine to
7333 demangle a C++ link name and prints the result.
7334 maintenance print type Print a type chain for a given symbol
7336 * Change to .gdbinit file processing
7338 We now read the $HOME/.gdbinit file before processing the argv arguments
7339 (e.g. reading symbol files or core files). This allows global parameters to
7340 be set, which will apply during the symbol reading. The ./.gdbinit is still
7341 read after argv processing.
7343 * New hosts supported
7345 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7347 GNU/Linux support i386-unknown-linux or linux
7349 We are also including code to support the HP/PA running BSD and HPUX. This
7350 is almost guaranteed not to work, as we didn't have time to test or build it
7351 for this release. We are including it so that the more adventurous (or
7352 masochistic) of you can play with it. We also had major problems with the
7353 fact that the compiler that we got from HP doesn't support the -g option.
7356 * New targets supported
7358 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7360 * More smarts about finding #include files
7362 GDB now remembers the compilation directory for all include files, and for
7363 all files from which C is generated (like yacc and lex sources). This
7364 greatly improves GDB's ability to find yacc/lex sources, and include files,
7365 especially if you are debugging your program from a directory different from
7366 the one that contains your sources.
7368 We also fixed a bug which caused difficulty with listing and setting
7369 breakpoints in include files which contain C code. (In the past, you had to
7370 try twice in order to list an include file that you hadn't looked at before.)
7372 * Interesting infernals change
7374 GDB now deals with arbitrary numbers of sections, where the symbols for each
7375 section must be relocated relative to that section's landing place in the
7376 target's address space. This work was needed to support ELF with embedded
7377 stabs used by Solaris-2.0.
7379 * Bug fixes (of course!)
7381 There have been loads of fixes for the following things:
7382 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7383 i960, stabs, DOS(GO32), procfs, etc...
7385 See the ChangeLog for details.
7387 *** Changes in GDB-4.5:
7389 * New machines supported (host and target)
7391 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7393 SGI Irix-4.x mips-sgi-irix4 or iris4
7395 * New malloc package
7397 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7398 Mmalloc is capable of handling multiple heaps of memory. It is also
7399 capable of saving a heap to a file, and then mapping it back in later.
7400 This can be used to greatly speedup the startup of GDB by using a
7401 pre-parsed symbol table which lives in a mmalloc managed heap. For
7402 more details, please read mmalloc/mmalloc.texi.
7406 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7407 'help info proc' for details.
7409 * MIPS ecoff symbol table format
7411 The code that reads MIPS symbol table format is now supported on all hosts.
7412 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7415 * File name changes for MS-DOS
7417 Many files in the config directories have been renamed to make it easier to
7418 support GDB on MS-DOSe systems (which have very restrictive file name
7419 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7420 environment) is close to working but has some remaining problems. Note
7421 that debugging of DOS programs is not supported, due to limitations
7422 in the ``operating system'', but it can be used to host cross-debugging.
7424 * Cross byte order fixes
7426 Many fixes have been made to support cross debugging of Sparc and MIPS
7427 targets from hosts whose byte order differs.
7429 * New -mapped and -readnow options
7431 If memory-mapped files are available on your system through the 'mmap'
7432 system call, you can use the -mapped option on the `file' or
7433 `symbol-file' commands to cause GDB to write the symbols from your
7434 program into a reusable file. If the program you are debugging is
7435 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7436 Future GDB debugging sessions will notice the presence of this file,
7437 and will quickly map in symbol information from it, rather than reading
7438 the symbol table from the executable program. Using the '-mapped'
7439 option in a GDB `file' or `symbol-file' command has the same effect as
7440 starting GDB with the '-mapped' command-line option.
7442 You can cause GDB to read the entire symbol table immediately by using
7443 the '-readnow' option with any of the commands that load symbol table
7444 information (or on the GDB command line). This makes the command
7445 slower, but makes future operations faster.
7447 The -mapped and -readnow options are typically combined in order to
7448 build a `fred.syms' file that contains complete symbol information.
7449 A simple GDB invocation to do nothing but build a `.syms' file for future
7452 gdb -batch -nx -mapped -readnow programname
7454 The `.syms' file is specific to the host machine on which GDB is run.
7455 It holds an exact image of GDB's internal symbol table. It cannot be
7456 shared across multiple host platforms.
7458 * longjmp() handling
7460 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7461 siglongjmp() without losing control. This feature has not yet been ported to
7462 all systems. It currently works on many 386 platforms, all MIPS-based
7463 platforms (SGI, DECstation, etc), and Sun3/4.
7467 Preliminary work has been put in to support the new Solaris OS from Sun. At
7468 this time, it can control and debug processes, but it is not capable of
7473 As always, many many bug fixes. The major areas were with g++, and mipsread.
7474 People using the MIPS-based platforms should experience fewer mysterious
7475 crashes and trashed symbol tables.
7477 *** Changes in GDB-4.4:
7479 * New machines supported (host and target)
7481 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7483 BSD Reno on Vax vax-dec-bsd
7484 Ultrix on Vax vax-dec-ultrix
7486 * New machines supported (target)
7488 AMD 29000 embedded, using EBMON a29k-none-none
7492 GDB continues to improve its handling of C++. `References' work better.
7493 The demangler has also been improved, and now deals with symbols mangled as
7494 per the Annotated C++ Reference Guide.
7496 GDB also now handles `stabs' symbol information embedded in MIPS
7497 `ecoff' symbol tables. Since the ecoff format was not easily
7498 extensible to handle new languages such as C++, this appeared to be a
7499 good way to put C++ debugging info into MIPS binaries. This option
7500 will be supported in the GNU C compiler, version 2, when it is
7503 * New features for SVR4
7505 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7506 shared libraries. Debugging dynamically linked programs should present
7507 only minor differences from debugging statically linked programs.
7509 The `info proc' command will print out information about any process
7510 on an SVR4 system (including the one you are debugging). At the moment,
7511 it prints the address mappings of the process.
7513 If you bring up GDB on another SVR4 system, please send mail to
7514 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7516 * Better dynamic linking support in SunOS
7518 Reading symbols from shared libraries which contain debugging symbols
7519 now works properly. However, there remain issues such as automatic
7520 skipping of `transfer vector' code during function calls, which
7521 make it harder to debug code in a shared library, than to debug the
7522 same code linked statically.
7526 GDB is now using the latest `getopt' routines from the FSF. This
7527 version accepts the -- prefix for options with long names. GDB will
7528 continue to accept the old forms (-option and +option) as well.
7529 Various single letter abbreviations for options have been explicity
7530 added to the option table so that they won't get overshadowed in the
7531 future by other options that begin with the same letter.
7535 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7536 Many assorted bugs have been handled. Many more remain to be handled.
7537 See the various ChangeLog files (primarily in gdb and bfd) for details.
7540 *** Changes in GDB-4.3:
7542 * New machines supported (host and target)
7544 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7545 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7546 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7548 * Almost SCO Unix support
7550 We had hoped to support:
7551 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7552 (except for core file support), but we discovered very late in the release
7553 that it has problems with process groups that render gdb unusable. Sorry
7554 about that. I encourage people to fix it and post the fixes.
7556 * Preliminary ELF and DWARF support
7558 GDB can read ELF object files on System V Release 4, and can handle
7559 debugging records for C, in DWARF format, in ELF files. This support
7560 is preliminary. If you bring up GDB on another SVR4 system, please
7561 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7566 GDB now uses the latest `readline' library. One user-visible change
7567 is that two tabs will list possible command completions, which previously
7568 required typing M-? (meta-question mark, or ESC ?).
7572 The `stepi' bug that many of you noticed has been squashed.
7573 Many bugs in C++ have been handled. Many more remain to be handled.
7574 See the various ChangeLog files (primarily in gdb and bfd) for details.
7576 * State of the MIPS world (in case you wondered):
7578 GDB can understand the symbol tables emitted by the compilers
7579 supplied by most vendors of MIPS-based machines, including DEC. These
7580 symbol tables are in a format that essentially nobody else uses.
7582 Some versions of gcc come with an assembler post-processor called
7583 mips-tfile. This program is required if you want to do source-level
7584 debugging of gcc-compiled programs. I believe FSF does not ship
7585 mips-tfile with gcc version 1, but it will eventually come with gcc
7588 Debugging of g++ output remains a problem. g++ version 1.xx does not
7589 really support it at all. (If you're lucky, you should be able to get
7590 line numbers and stack traces to work, but no parameters or local
7591 variables.) With some work it should be possible to improve the
7594 When gcc version 2 is released, you will have somewhat better luck.
7595 However, even then you will get confusing results for inheritance and
7598 We will eventually provide full debugging of g++ output on
7599 DECstations. This will probably involve some kind of stabs-in-ecoff
7600 encapulation, but the details have not been worked out yet.
7603 *** Changes in GDB-4.2:
7605 * Improved configuration
7607 Only one copy of `configure' exists now, and it is not self-modifying.
7608 Porting BFD is simpler.
7612 The `step' and `next' commands now only stop at the first instruction
7613 of a source line. This prevents the multiple stops that used to occur
7614 in switch statements, for-loops, etc. `Step' continues to stop if a
7615 function that has debugging information is called within the line.
7619 Lots of small bugs fixed. More remain.
7621 * New host supported (not target)
7623 Intel 386 PC clone running Mach i386-none-mach
7626 *** Changes in GDB-4.1:
7628 * Multiple source language support
7630 GDB now has internal scaffolding to handle several source languages.
7631 It determines the type of each source file from its filename extension,
7632 and will switch expression parsing and number formatting to match the
7633 language of the function in the currently selected stack frame.
7634 You can also specifically set the language to be used, with
7635 `set language c' or `set language modula-2'.
7639 GDB now has preliminary support for the GNU Modula-2 compiler,
7640 currently under development at the State University of New York at
7641 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7642 continue through the fall of 1991 and into 1992.
7644 Other Modula-2 compilers are currently not supported, and attempting to
7645 debug programs compiled with them will likely result in an error as the
7646 symbol table is read. Feel free to work on it, though!
7648 There are hooks in GDB for strict type checking and range checking,
7649 in the `Modula-2 philosophy', but they do not currently work.
7653 GDB can now write to executable and core files (e.g. patch
7654 a variable's value). You must turn this switch on, specify
7655 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7656 by assigning a new value to a variable. Modifications take
7659 * Automatic SunOS shared library reading
7661 When you run your program, GDB automatically determines where its
7662 shared libraries (if any) have been loaded, and reads their symbols.
7663 The `share' command is no longer needed. This also works when
7664 examining core files.
7668 You can specify the number of lines that the `list' command shows.
7671 * New machines supported (host and target)
7673 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7674 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7675 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7677 * New hosts supported (not targets)
7679 IBM RT/PC: romp-ibm-aix or rtpc
7681 * New targets supported (not hosts)
7683 AMD 29000 embedded with COFF a29k-none-coff
7684 AMD 29000 embedded with a.out a29k-none-aout
7685 Ultracomputer remote kernel debug a29k-nyu-kern
7687 * New remote interfaces
7693 *** Changes in GDB-4.0:
7697 Wide output is wrapped at good places to make the output more readable.
7699 Gdb now supports cross-debugging from a host machine of one type to a
7700 target machine of another type. Communication with the target system
7701 is over serial lines. The ``target'' command handles connecting to the
7702 remote system; the ``load'' command will download a program into the
7703 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7704 also supports debugging of realtime processes running under VxWorks,
7705 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7706 stub on the target system.
7708 New CPUs supported include the AMD 29000 and Intel 960.
7710 GDB now reads object files and symbol tables via a ``binary file''
7711 library, which allows a single copy of GDB to debug programs of multiple
7712 object file types such as a.out and coff.
7714 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7715 refcard.dvi and refcard.ps are available to format it).
7718 * Control-Variable user interface simplified
7720 All variables that control the operation of the debugger can be set
7721 by the ``set'' command, and displayed by the ``show'' command.
7723 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7724 ``Show prompt'' produces the response:
7725 Gdb's prompt is new-gdb=>.
7727 What follows are the NEW set commands. The command ``help set'' will
7728 print a complete list of old and new set commands. ``help set FOO''
7729 will give a longer description of the variable FOO. ``show'' will show
7730 all of the variable descriptions and their current settings.
7732 confirm on/off: Enables warning questions for operations that are
7733 hard to recover from, e.g. rerunning the program while
7734 it is already running. Default is ON.
7736 editing on/off: Enables EMACS style command line editing
7737 of input. Previous lines can be recalled with
7738 control-P, the current line can be edited with control-B,
7739 you can search for commands with control-R, etc.
7742 history filename NAME: NAME is where the gdb command history
7743 will be stored. The default is .gdb_history,
7744 or the value of the environment variable
7747 history size N: The size, in commands, of the command history. The
7748 default is 256, or the value of the environment variable
7751 history save on/off: If this value is set to ON, the history file will
7752 be saved after exiting gdb. If set to OFF, the
7753 file will not be saved. The default is OFF.
7755 history expansion on/off: If this value is set to ON, then csh-like
7756 history expansion will be performed on
7757 command line input. The default is OFF.
7759 radix N: Sets the default radix for input and output. It can be set
7760 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7761 in the current radix, so "set radix 10" is always a no-op.
7763 height N: This integer value is the number of lines on a page. Default
7764 is 24, the current `stty rows'' setting, or the ``li#''
7765 setting from the termcap entry matching the environment
7768 width N: This integer value is the number of characters on a line.
7769 Default is 80, the current `stty cols'' setting, or the ``co#''
7770 setting from the termcap entry matching the environment
7773 Note: ``set screensize'' is obsolete. Use ``set height'' and
7774 ``set width'' instead.
7776 print address on/off: Print memory addresses in various command displays,
7777 such as stack traces and structure values. Gdb looks
7778 more ``symbolic'' if you turn this off; it looks more
7779 ``machine level'' with it on. Default is ON.
7781 print array on/off: Prettyprint arrays. New convenient format! Default
7784 print demangle on/off: Print C++ symbols in "source" form if on,
7787 print asm-demangle on/off: Same, for assembler level printouts
7790 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7793 * Support for Epoch Environment.
7795 The epoch environment is a version of Emacs v18 with windowing. One
7796 new command, ``inspect'', is identical to ``print'', except that if you
7797 are running in the epoch environment, the value is printed in its own
7801 * Support for Shared Libraries
7803 GDB can now debug programs and core files that use SunOS shared libraries.
7804 Symbols from a shared library cannot be referenced
7805 before the shared library has been linked with the program (this
7806 happens after you type ``run'' and before the function main() is entered).
7807 At any time after this linking (including when examining core files
7808 from dynamically linked programs), gdb reads the symbols from each
7809 shared library when you type the ``sharedlibrary'' command.
7810 It can be abbreviated ``share''.
7812 sharedlibrary REGEXP: Load shared object library symbols for files
7813 matching a unix regular expression. No argument
7814 indicates to load symbols for all shared libraries.
7816 info sharedlibrary: Status of loaded shared libraries.
7821 A watchpoint stops execution of a program whenever the value of an
7822 expression changes. Checking for this slows down execution
7823 tremendously whenever you are in the scope of the expression, but is
7824 quite useful for catching tough ``bit-spreader'' or pointer misuse
7825 problems. Some machines such as the 386 have hardware for doing this
7826 more quickly, and future versions of gdb will use this hardware.
7828 watch EXP: Set a watchpoint (breakpoint) for an expression.
7830 info watchpoints: Information about your watchpoints.
7832 delete N: Deletes watchpoint number N (same as breakpoints).
7833 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7834 enable N: Re-enables watchpoint number N (same as breakpoints).
7837 * C++ multiple inheritance
7839 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7842 * C++ exception handling
7844 Gdb now supports limited C++ exception handling. Besides the existing
7845 ability to breakpoint on an exception handler, gdb can breakpoint on
7846 the raising of an exception (before the stack is peeled back to the
7849 catch FOO: If there is a FOO exception handler in the dynamic scope,
7850 set a breakpoint to catch exceptions which may be raised there.
7851 Multiple exceptions (``catch foo bar baz'') may be caught.
7853 info catch: Lists all exceptions which may be caught in the
7854 current stack frame.
7857 * Minor command changes
7859 The command ``call func (arg, arg, ...)'' now acts like the print
7860 command, except it does not print or save a value if the function's result
7861 is void. This is similar to dbx usage.
7863 The ``up'' and ``down'' commands now always print the frame they end up
7864 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7865 frames without printing.
7867 * New directory command
7869 'dir' now adds directories to the FRONT of the source search path.
7870 The path starts off empty. Source files that contain debug information
7871 about the directory in which they were compiled can be found even
7872 with an empty path; Sun CC and GCC include this information. If GDB can't
7873 find your source file in the current directory, type "dir .".
7875 * Configuring GDB for compilation
7877 For normal use, type ``./configure host''. See README or gdb.texinfo
7880 GDB now handles cross debugging. If you are remotely debugging between
7881 two different machines, type ``./configure host -target=targ''.
7882 Host is the machine where GDB will run; targ is the machine
7883 where the program that you are debugging will run.