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 * Multi-target debugging support
30 GDB now supports debugging multiple target connections
31 simultaneously. For example, you can now have each inferior
32 connected to different remote servers running in different machines,
33 or have one inferior debugging a local native process, an inferior
34 debugging a core dump, etc.
36 This support is experimental and comes with some limitations -- you
37 can only resume multiple targets simultaneously if all targets
38 support non-stop mode, and all remote stubs or servers must support
39 the same set of remote protocol features exactly. See also "info
40 connections" and "add-inferior -no-connection" below, and "maint set
41 target-non-stop" in the user manual.
43 * New features in the GDB remote stub, GDBserver
45 ** GDBserver is now supported on RISC-V GNU/Linux.
47 ** GDBserver no longer supports these host triplets:
58 i[34567]86-*-mingw32ce*
60 * Debugging MS-Windows processes now sets $_exitsignal when the
61 inferior is terminated by a signal, instead of setting $_exitcode.
63 * Multithreaded symbol loading has now been enabled by default on systems
64 that support it (see entry for GDB 9, below), providing faster
65 performance for programs with many symbols.
67 * The $_siginfo convenience variable now also works on Windows targets,
68 and will display the EXCEPTION_RECORD of the last handled exception.
70 * TUI windows can now be arranged horizontally.
72 * The command history filename can now be set to the empty string
73 either using 'set history filename' or by setting 'GDBHISTFILE=' in
74 the environment. The effect of setting this filename to the empty
75 string is that GDB will not try to load any previous command
78 * On Windows targets, it is now possible to debug 32-bit programs with a
83 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
84 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
85 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
86 running process, this new option indicates whether to detect
87 a mismatch between the current executable file loaded by GDB and the
88 executable file used to start the process. If 'ask', the default,
89 display a warning and ask the user whether to load the process
90 executable file; if 'warn', just display a warning; if 'off', don't
91 attempt to detect a mismatch.
93 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
94 Define a new TUI layout, specifying its name and the windows that
97 maintenance print xml-tdesc [FILE]
98 Prints the current target description as an XML document. If the
99 optional FILE is provided (which is an XML target description) then
100 the target description is read from FILE into GDB, and then
103 maintenance print core-file-backed-mappings
104 Prints file-backed mappings loaded from a core file's note section.
105 Output is expected to be similar to that of "info proc mappings".
109 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
110 The alias command can now specify default args for an alias.
111 GDB automatically prepends the alias default args to the argument list
112 provided explicitly by the user.
113 For example, to have a backtrace with full details, you can define
115 'alias bt_ALL = backtrace -entry-values both -frame-arg all
116 -past-main -past-entry -full'.
117 Alias default arguments can also use a set of nested 'with' commands,
118 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
119 defines the alias pp10 that will pretty print a maximum of 10 elements
120 of the given expression (if the expression is an array).
124 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
129 ** gdb.register_window_type can be used to implement new TUI windows
132 ** Dynamic types can now be queried. gdb.Type has a new attribute,
133 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
134 field of a dynamic type may have None for its "bitpos" attribute
137 ** Commands written in Python can be in the "TUI" help class by
138 registering with the new constant gdb.COMMAND_TUI.
140 ** New method gdb.PendingFrame.architecture () to retrieve the
141 architecture of the pending frame.
143 ** New gdb.Architecture.registers method that returns a
144 gdb.RegisterDescriptorIterator object, an iterator that returns
145 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
146 way to query the registers available for an architecture.
148 ** New gdb.Architecture.register_groups method that returns a
149 gdb.RegisterGroupIterator object, an iterator that returns
150 gdb.RegisterGroup objects. The new RegisterGroup is a way to
151 discover the available register groups.
155 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
157 ** Procedures 'memory-port-read-buffer-size',
158 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
159 and 'set-memory-port-write-buffer-size!' are deprecated. When
160 using Guile 2.2 and later, users who need to control the size of
161 a memory port's internal buffer can use the 'setvbuf' procedure.
165 * 'thread-exited' event is now available in the annotations interface.
167 * New built-in convenience variables $_gdb_major and $_gdb_minor
168 provide the GDB version. They are handy for conditionally using
169 features available only in or since specific GDB versions, in
170 scripts that should work error-free with many different versions,
171 such as in system-wide init files.
173 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
174 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
175 of the GDB settings and the GDB maintenance settings. They are handy
176 for changing the logic of user defined commands depending on the
177 current GDB settings.
179 * GDB now supports Thread Local Storage (TLS) variables on several
180 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
181 architectures require kernel changes. TLS is not yet supported for
182 amd64 and i386 process core dumps.
184 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
185 addresses that required unmasking are shown in the backtrace with the
188 * Two new convenience functions $_cimag and $_creal that extract the
189 imaginary and real parts respectively from complex numbers.
191 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
192 provide the exitcode or exit status of the shell commands launched by
193 GDB commands such as "shell", "pipe" and "make".
195 * The command define-prefix can now define user defined prefix commands.
196 User defined commands can now be defined using these user defined prefix
199 * Command names can now use the . character.
201 * The RX port now supports XML target descriptions.
203 * GDB now shows the Ada task names at more places, e.g. in task switching
206 * GDB can now be compiled with Python 3 on Windows.
208 * New convenience variable $_ada_exception holds the address of the
209 Ada exception being thrown. This is set by Ada-related catchpoints.
211 * GDB can now place breakpoints on nested functions and subroutines in
212 Fortran code. The '::' operator can be used between parent and
213 child scopes when placing breakpoints, for example:
215 (gdb) break outer_function::inner_function
217 The 'outer_function::' prefix is only needed if 'inner_function' is
218 not visible in the current scope.
220 * In addition to the system-wide gdbinit file, if configured with
221 --with-system-gdbinit-dir, GDB will now also load files in that directory
222 as system gdbinit files, unless the -nx or -n flag is provided. Files
223 with extensions .gdb, .py and .scm are supported as long as GDB was
224 compiled with support for that language.
226 * GDB now supports multithreaded symbol loading for higher performance.
227 This feature is still in testing, so it is disabled by default. You
228 can turn it on using 'maint set worker-threads unlimited'.
232 ** The gdb.Value type has a new method 'format_string' which returns a
233 string representing the value. The formatting is controlled by the
234 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
235 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
236 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
238 ** gdb.Type has a new property 'objfile' which returns the objfile the
241 ** The frame information printed by the python frame filtering code
242 is now consistent with what the 'backtrace' command prints when
243 there are no filters, or when the 'backtrace' '-no-filters' option
246 ** The new function gdb.lookup_static_symbol can be used to look up
247 symbols with static linkage.
249 ** The new function gdb.lookup_static_symbols can be used to look up
250 all static symbols with static linkage.
252 ** gdb.Objfile has new methods 'lookup_global_symbol' and
253 'lookup_static_symbol' to lookup a symbol from this objfile only.
255 ** gdb.Block now supports the dictionary syntax for accessing symbols in
256 this block (e.g. block['local_variable']).
260 | [COMMAND] | SHELL_COMMAND
261 | -d DELIM COMMAND DELIM SHELL_COMMAND
262 pipe [COMMAND] | SHELL_COMMAND
263 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
264 Executes COMMAND and sends its output to SHELL_COMMAND.
265 With no COMMAND, repeat the last executed command
266 and send its output to SHELL_COMMAND.
268 define-prefix COMMAND
269 Define or mark a command as a user-defined prefix command.
271 with SETTING [VALUE] [-- COMMAND]
272 w SETTING [VALUE] [-- COMMAND]
273 Temporarily set SETTING, run COMMAND, and restore SETTING.
274 Usage: with SETTING -- COMMAND
275 With no COMMAND, repeats the last executed command.
276 SETTING is any GDB setting you can change with the "set"
277 subcommands. For example, 'with language c -- print someobj'
278 temporarily switches to the C language in order to print someobj.
279 Settings can be combined: 'w lang c -- w print elements unlimited --
280 usercmd' switches to the C language and runs usercmd with no limit
281 of array elements to print.
283 maint with SETTING [VALUE] [-- COMMAND]
284 Like "with", but works with "maintenance set" settings.
286 set may-call-functions [on|off]
287 show may-call-functions
288 This controls whether GDB will attempt to call functions in
289 the program, such as with expressions in the print command. It
290 defaults to on. Calling functions in the program being debugged
291 can have undesired side effects. It is now possible to forbid
292 such function calls. If function calls are forbidden, GDB will throw
293 an error when a command (such as print expression) calls a function
296 set print finish [on|off]
298 This controls whether the `finish' command will display the value
299 that is returned by the current function. When `off', the value is
300 still entered into the value history, but it is not printed. The
305 Allows deeply nested structures to be simplified when printing by
306 replacing deeply nested parts (beyond the max-depth) with ellipses.
307 The default max-depth is 20, but this can be set to unlimited to get
308 the old behavior back.
310 set print raw-values [on|off]
311 show print raw-values
312 By default, GDB applies the enabled pretty printers when printing a
313 value. This allows to ignore the enabled pretty printers for a series
314 of commands. The default is 'off'.
316 set logging debugredirect [on|off]
317 By default, GDB debug output will go to both the terminal and the logfile.
318 Set if you want debug output to go only to the log file.
320 set style title foreground COLOR
321 set style title background COLOR
322 set style title intensity VALUE
323 Control the styling of titles.
325 set style highlight foreground COLOR
326 set style highlight background COLOR
327 set style highlight intensity VALUE
328 Control the styling of highlightings.
330 maint set worker-threads
331 maint show worker-threads
332 Control the number of worker threads that can be used by GDB. The
333 default is 0. "unlimited" lets GDB choose a number that is
334 reasonable. Currently worker threads are only used when demangling
335 the names of linker symbols.
337 set style tui-border foreground COLOR
338 set style tui-border background COLOR
339 Control the styling of TUI borders.
341 set style tui-active-border foreground COLOR
342 set style tui-active-border background COLOR
343 Control the styling of the active TUI border.
345 maint set test-settings KIND
346 maint show test-settings KIND
347 A set of commands used by the testsuite for exercising the settings
350 maint set tui-resize-message [on|off]
351 maint show tui-resize-message
352 Control whether GDB prints a message each time the terminal is
353 resized when in TUI mode. This is primarily useful for testing the
356 set print frame-info [short-location|location|location-and-address
357 |source-and-location|source-line|auto]
358 show print frame-info
359 This controls what frame information is printed by the commands printing
360 a frame. This setting will e.g. influence the behaviour of 'backtrace',
361 'frame', 'stepi'. The python frame filtering also respect this setting.
362 The 'backtrace' '-frame-info' option can override this global setting.
364 set tui compact-source
365 show tui compact-source
367 Enable the "compact" display mode for the TUI source window. The
368 compact display uses only as much space as is needed for the line
369 numbers in the current file, and only a single space to separate the
370 line numbers from the source.
372 info modules [-q] [REGEXP]
373 Return a list of Fortran modules matching REGEXP, or all modules if
376 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
377 Return a list of functions within all modules, grouped by module.
378 The list of functions can be restricted with the optional regular
379 expressions. MODULE_REGEXP matches against the module name,
380 TYPE_REGEXP matches against the function type signature, and REGEXP
381 matches against the function name.
383 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
384 Return a list of variables within all modules, grouped by module.
385 The list of variables can be restricted with the optional regular
386 expressions. MODULE_REGEXP matches against the module name,
387 TYPE_REGEXP matches against the variable type, and REGEXP matches
388 against the variable name.
390 set debug remote-packet-max-chars
391 show debug remote-packet-max-chars
392 Controls the number of characters to output in a remote packet when using
394 The default is 512 bytes.
397 Lists the target connections currently in use.
402 The "help" command uses the title style to enhance the
403 readibility of its output by styling the classes and
407 Similarly to "help", the "apropos" command also uses the
408 title style for the command names. "apropos" accepts now
409 a flag "-v" (verbose) to show the full documentation
410 of matching commands and to use the highlight style to mark
411 the documentation parts matching REGEXP.
415 The GDB printf and eval commands can now print C-style and Ada-style
416 string convenience variables without calling functions in the program.
417 This allows to do formatted printing of strings without having
418 a running inferior, or when debugging a core dump.
420 info sources [-dirname | -basename] [--] [REGEXP]
421 This command has now optional arguments to only print the files
422 whose names match REGEXP. The arguments -dirname and -basename
423 allow to restrict matching respectively to the dirname and basename
427 The "show style" and its subcommands are now styling
428 a style name in their output using its own style, to help
429 the user visualize the different styles.
431 set print frame-arguments
432 The new value 'presence' indicates to only indicate the presence of
433 arguments using ..., instead of printing argument names and values.
435 set print raw-frame-arguments
436 show print raw-frame-arguments
438 These commands replace the similarly-named "set/show print raw
439 frame-arguments" commands (now with a dash instead of a space). The
440 old commands are now deprecated and may be removed in a future
443 add-inferior [-no-connection]
444 The add-inferior command now supports a "-no-connection" flag that
445 makes the new inferior start with no target connection associated.
446 By default, the new inferior inherits the target connection of the
447 current inferior. See also "info connections".
450 This command's output now includes a new "Connection" column
451 indicating which target connection an inferior is bound to. See
452 "info connections" above.
454 maint test-options require-delimiter
455 maint test-options unknown-is-error
456 maint test-options unknown-is-operand
457 maint show test-options-completion-result
458 Commands used by the testsuite to validate the command options
461 focus, winheight, +, -, >, <
462 These commands are now case-sensitive.
464 * New command options, command completion
466 GDB now has a standard infrastructure to support dash-style command
467 options ('-OPT'). One benefit is that commands that use it can
468 easily support completion of command line arguments. Try "CMD
469 -[TAB]" or "help CMD" to find options supported by a command. Over
470 time, we intend to migrate most commands to this infrastructure. A
471 number of commands got support for new command options in this
474 ** The "print" and "compile print" commands now support a number of
475 options that allow overriding relevant global print settings as
476 set by "set print" subcommands:
480 -array-indexes [on|off]
481 -elements NUMBER|unlimited
486 -repeats NUMBER|unlimited
487 -static-members [on|off]
492 Note that because the "print"/"compile print" commands accept
493 arbitrary expressions which may look like options (including
494 abbreviations), if you specify any command option, then you must
495 use a double dash ("--") to mark the end of argument processing.
497 ** The "backtrace" command now supports a number of options that
498 allow overriding relevant global print settings as set by "set
499 backtrace" and "set print" subcommands:
501 -entry-values no|only|preferred|if-needed|both|compact|default
502 -frame-arguments all|scalars|none
503 -raw-frame-arguments [on|off]
504 -frame-info auto|source-line|location|source-and-location
505 |location-and-address|short-location
509 In addition, the full/no-filters/hide qualifiers are now also
510 exposed as command options too:
516 ** The "frame apply", "tfaas" and "faas" commands similarly now
517 support the following options:
522 ** The new "info sources" options -dirname and -basename options
523 are using the standard '-OPT' infrastructure.
525 All options above can also be abbreviated. The argument of boolean
526 (on/off) options can be 0/1 too, and also the argument is assumed
527 "on" if omitted. This allows writing compact command invocations,
530 (gdb) p -ra -p -o 0 -- *myptr
532 The above is equivalent to:
534 (gdb) print -raw-values -pretty -object off -- *myptr
536 ** The "info types" command now supports the '-q' flag to disable
537 printing of some header information in a similar fashion to "info
538 variables" and "info functions".
540 ** The "info variables", "info functions", and "whereis" commands
541 now take a '-n' flag that excludes non-debug symbols (symbols
542 from the symbol table, not from the debug info such as DWARF)
545 * Completion improvements
547 ** GDB can now complete the options of the "thread apply all" and
548 "taas" commands, and their "-ascending" option can now be
551 ** GDB can now complete the options of the "info threads", "info
552 functions", "info variables", "info locals", and "info args"
555 ** GDB can now complete the options of the "compile file" and
556 "compile code" commands. The "compile file" command now
557 completes on filenames.
559 ** GDB can now complete the backtrace command's
560 "full/no-filters/hide" qualifiers.
562 * In settings, you can now abbreviate "unlimited".
564 E.g., "set print elements u" is now equivalent to "set print
570 This lists all the possible completions for the rest of the line, if it
571 were to be given as a command itself. This is intended for use by MI
572 frontends in cases when separate CLI and MI channels cannot be used.
574 -catch-throw, -catch-rethrow, and -catch-catch
575 These can be used to catch C++ exceptions in a similar fashion to
576 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
578 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
579 These commands are the MI equivalent of the CLI commands 'info
580 functions', 'info types', and 'info variables' respectively.
582 -symbol-info-modules, this is the MI equivalent of the CLI 'info
585 -symbol-info-module-functions and -symbol-info-module-variables.
586 These commands are the MI equivalent of the CLI commands 'info
587 module functions' and 'info module variables'.
591 ** The default version of the MI interpreter is now 3 (-i=mi3).
593 ** The output of information about multi-location breakpoints (which is
594 syntactically incorrect in MI 2) has changed in MI 3. This affects
595 the following commands and events:
599 - =breakpoint-created
600 - =breakpoint-modified
602 The -fix-multi-location-breakpoint-output command can be used to enable
603 this behavior with previous MI versions.
605 ** Backtraces and frames include a new optional field addr_flags which is
606 given after the addr field. On AArch64 this contains PAC if the address
607 has been masked in the frame. On all other targets the field is not
612 The testsuite now creates the files gdb.cmd (containing the arguments
613 used to launch GDB) and gdb.in (containing all the commands sent to
614 GDB) in the output directory for each test script. Multiple invocations
615 are appended with .1, .2, .3 etc.
617 * Building GDB and GDBserver now requires GNU make >= 3.82.
619 Using another implementation of the make program or an earlier version of
620 GNU make to build GDB or GDBserver is not supported.
622 * Building GDB now requires GNU readline >= 7.0.
624 GDB now bundles GNU readline 8.0, but if you choose to use
625 --with-system-readline, only readline >= 7.0 can be used.
627 * The TUI SingleKey keymap is now named "SingleKey". This can be used
628 from .inputrc to bind keys in this keymap. This feature is only
629 available when gdb is built against GNU readline 8.0 or later.
631 * Removed targets and native configurations
633 GDB no longer supports debugging the Cell Broadband Engine. This includes
634 both debugging standalone Cell/B.E. SPU applications and integrated debugging
635 of Cell/B.E. applications that use both the PPU and SPU architectures.
641 * Removed targets and native configurations
643 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
646 *** Changes in GDB 8.3
648 * GDB and GDBserver now support access to additional registers on
649 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
652 * GDB now has experimental support for the compilation and injection of
653 C++ source code into the inferior. This beta release does not include
654 support for several language features, such as templates, constructors,
657 This feature requires GCC 7.1 or higher built with libcp1.so
660 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
661 can be passed using the '[ADDRESS]:PORT' notation, or the regular
662 'ADDRESS:PORT' method.
664 * DWARF index cache: GDB can now automatically save indices of DWARF
665 symbols on disk to speed up further loading of the same binaries.
667 * Ada task switching is now supported on aarch64-elf targets when
668 debugging a program using the Ravenscar Profile. For more information,
669 see the "Tasking Support when using the Ravenscar Profile" section
670 in the GDB user manual.
672 * GDB in batch mode now exits with status 1 if the last command to be
675 * The RISC-V target now supports target descriptions.
677 * System call catchpoints now support system call aliases on FreeBSD.
678 When the ABI of a system call changes in FreeBSD, this is
679 implemented by leaving a compatibility system call using the old ABI
680 at the existing number and allocating a new system call number for
681 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
682 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
683 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
684 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
685 so that a system call catchpoint for the 'kevent' system call will
686 catch invocations of both the 'kevent' and 'freebsd11_kevent'
687 binaries. This ensures that 'kevent' system calls are caught for
688 binaries using either the old or new ABIs.
690 * Terminal styling is now available for the CLI and the TUI. GNU
691 Source Highlight can additionally be used to provide styling of
692 source code snippets. See the "set style" commands, below, for more
695 * Removed support for old demangling styles arm, edg, gnu, hp and
700 set debug compile-cplus-types
701 show debug compile-cplus-types
702 Control the display of debug output about type conversion in the
703 C++ compile feature. Commands have no effect while compiling
708 Control whether debug output about files/functions skipping is
711 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
712 Apply a command to some frames.
713 FLAG arguments allow to control what output to produce and how to handle
714 errors raised when applying COMMAND to a frame.
717 Apply a command to all threads (ignoring errors and empty output).
718 Shortcut for 'thread apply all -s COMMAND'.
721 Apply a command to all frames (ignoring errors and empty output).
722 Shortcut for 'frame apply all -s COMMAND'.
725 Apply a command to all frames of all threads (ignoring errors and empty
727 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
729 maint set dwarf unwinders (on|off)
730 maint show dwarf unwinders
731 Control whether DWARF unwinders can be used.
734 Display a list of open files for a process.
738 Changes to the "frame", "select-frame", and "info frame" CLI commands.
739 These commands all now take a frame specification which
740 is either a frame level, or one of the keywords 'level', 'address',
741 'function', or 'view' followed by a parameter. Selecting a frame by
742 address, or viewing a frame outside the current backtrace now
743 requires the use of a keyword. Selecting a frame by level is
744 unchanged. The MI comment "-stack-select-frame" is unchanged.
746 target remote FILENAME
747 target extended-remote FILENAME
748 If FILENAME is a Unix domain socket, GDB will attempt to connect
749 to this socket instead of opening FILENAME as a character device.
751 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
752 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
753 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
754 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
755 These commands can now print only the searched entities
756 matching the provided regexp(s), giving a condition
757 on the entity names or entity types. The flag -q disables
758 printing headers or informations messages.
764 These commands now determine the syntax for the shown entities
765 according to the language chosen by `set language'. In particular,
766 `set language auto' means to automatically choose the language of
769 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
770 The 'thread apply' command accepts new FLAG arguments.
771 FLAG arguments allow to control what output to produce and how to handle
772 errors raised when applying COMMAND to a thread.
774 set tui tab-width NCHARS
775 show tui tab-width NCHARS
776 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
778 set style enabled [on|off]
780 Enable or disable terminal styling. Styling is enabled by default
781 on most hosts, but disabled by default when in batch mode.
783 set style sources [on|off]
785 Enable or disable source code styling. Source code styling is
786 enabled by default, but only takes effect if styling in general is
787 enabled, and if GDB was linked with GNU Source Highlight.
789 set style filename foreground COLOR
790 set style filename background COLOR
791 set style filename intensity VALUE
792 Control the styling of file names.
794 set style function foreground COLOR
795 set style function background COLOR
796 set style function intensity VALUE
797 Control the styling of function names.
799 set style variable foreground COLOR
800 set style variable background COLOR
801 set style variable intensity VALUE
802 Control the styling of variable names.
804 set style address foreground COLOR
805 set style address background COLOR
806 set style address intensity VALUE
807 Control the styling of addresses.
811 ** The '-data-disassemble' MI command now accepts an '-a' option to
812 disassemble the whole function surrounding the given program
813 counter value or function name. Support for this feature can be
814 verified by using the "-list-features" command, which should
815 contain "data-disassemble-a-option".
817 ** Command responses and notifications that include a frame now include
818 the frame's architecture in a new "arch" attribute.
820 * New native configurations
822 GNU/Linux/RISC-V riscv*-*-linux*
823 FreeBSD/riscv riscv*-*-freebsd*
827 GNU/Linux/RISC-V riscv*-*-linux*
829 CSKY GNU/LINUX csky*-*-linux
830 FreeBSD/riscv riscv*-*-freebsd*
832 GNU/Linux/OpenRISC or1k*-*-linux*
836 GDB no longer supports native debugging on versions of MS-Windows
841 ** GDB no longer supports Python versions less than 2.6.
843 ** The gdb.Inferior type has a new 'progspace' property, which is the program
844 space associated to that inferior.
846 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
847 of objfiles associated to that program space.
849 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
850 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
853 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
854 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
855 correct and did not work properly.
857 ** The gdb.Value type has a new constructor, which is used to construct a
858 gdb.Value from a Python buffer object and a gdb.Type.
864 Enable or disable the undefined behavior sanitizer. This is
865 disabled by default, but passing --enable-ubsan=yes or
866 --enable-ubsan=auto to configure will enable it. Enabling this can
867 cause a performance penalty. The undefined behavior sanitizer was
868 first introduced in GCC 4.9.
870 *** Changes in GDB 8.2
872 * The 'set disassembler-options' command now supports specifying options
875 * The 'symbol-file' command now accepts an '-o' option to add a relative
876 offset to all sections.
878 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
879 a relative offset to all sections, but it allows to override the load
880 address of individual sections using '-s'.
882 * The 'add-symbol-file' command no longer requires the second argument
883 (address of the text section).
885 * The endianness used with the 'set endian auto' mode in the absence of
886 an executable selected for debugging is now the last endianness chosen
887 either by one of the 'set endian big' and 'set endian little' commands
888 or by inferring from the last executable used, rather than the startup
891 * The pager now allows a "c" response, meaning to disable the pager
892 for the rest of the current command.
894 * The commands 'info variables/functions/types' now show the source line
895 numbers of symbol definitions when available.
897 * 'info proc' now works on running processes on FreeBSD systems and core
898 files created on FreeBSD systems.
900 * C expressions can now use _Alignof, and C++ expressions can now use
903 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
904 the vector length while the process is running.
910 Control display of debugging info regarding the FreeBSD native target.
912 set|show varsize-limit
913 This new setting allows the user to control the maximum size of Ada
914 objects being printed when those objects have a variable type,
915 instead of that maximum size being hardcoded to 65536 bytes.
917 set|show record btrace cpu
918 Controls the processor to be used for enabling errata workarounds for
921 maint check libthread-db
922 Run integrity checks on the current inferior's thread debugging
925 maint set check-libthread-db (on|off)
926 maint show check-libthread-db
927 Control whether to run integrity checks on inferior specific thread
928 debugging libraries as they are loaded. The default is not to
933 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
935 ** The commands attached to a breakpoint can be set by assigning to
936 the breakpoint's "commands" field.
938 ** gdb.execute can now execute multi-line gdb commands.
940 ** The new functions gdb.convenience_variable and
941 gdb.set_convenience_variable can be used to get and set the value
942 of convenience variables.
944 ** A gdb.Parameter will no longer print the "set" help text on an
945 ordinary "set"; instead by default a "set" will be silent unless
946 the get_set_string method returns a non-empty string.
950 RiscV ELF riscv*-*-elf
952 * Removed targets and native configurations
954 m88k running OpenBSD m88*-*-openbsd*
955 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
956 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
957 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
959 * Aarch64/Linux hardware watchpoints improvements
961 Hardware watchpoints on unaligned addresses are now properly
962 supported when running Linux kernel 4.10 or higher: read and access
963 watchpoints are no longer spuriously missed, and all watchpoints
964 lengths between 1 and 8 bytes are supported. On older kernels,
965 watchpoints set on unaligned addresses are no longer missed, with
966 the tradeoff that there is a possibility of false hits being
971 --enable-codesign=CERT
972 This can be used to invoke "codesign -s CERT" after building gdb.
973 This option is useful on macOS, where code signing is required for
974 gdb to work properly.
976 --disable-gdbcli has been removed
977 This is now silently accepted, but does nothing.
979 *** Changes in GDB 8.1
981 * GDB now supports dynamically creating arbitrary register groups specified
982 in XML target descriptions. This allows for finer grain grouping of
983 registers on systems with a large amount of registers.
985 * The 'ptype' command now accepts a '/o' flag, which prints the
986 offsets and sizes of fields in a struct, like the pahole(1) tool.
988 * New "--readnever" command line option instructs GDB to not read each
989 symbol file's symbolic debug information. This makes startup faster
990 but at the expense of not being able to perform symbolic debugging.
991 This option is intended for use cases where symbolic debugging will
992 not be used, e.g., when you only need to dump the debuggee's core.
994 * GDB now uses the GNU MPFR library, if available, to emulate target
995 floating-point arithmetic during expression evaluation when the target
996 uses different floating-point formats than the host. At least version
997 3.1 of GNU MPFR is required.
999 * GDB now supports access to the guarded-storage-control registers and the
1000 software-based guarded-storage broadcast control registers on IBM z14.
1002 * On Unix systems, GDB now supports transmitting environment variables
1003 that are to be set or unset to GDBserver. These variables will
1004 affect the environment to be passed to the remote inferior.
1006 To inform GDB of environment variables that are to be transmitted to
1007 GDBserver, use the "set environment" command. Only user set
1008 environment variables are sent to GDBserver.
1010 To inform GDB of environment variables that are to be unset before
1011 the remote inferior is started by the GDBserver, use the "unset
1012 environment" command.
1014 * Completion improvements
1016 ** GDB can now complete function parameters in linespecs and
1017 explicit locations without quoting. When setting breakpoints,
1018 quoting around functions names to help with TAB-completion is
1019 generally no longer necessary. For example, this now completes
1022 (gdb) b function(in[TAB]
1023 (gdb) b function(int)
1025 Related, GDB is no longer confused with completing functions in
1026 C++ anonymous namespaces:
1029 (gdb) b (anonymous namespace)::[TAB][TAB]
1030 (anonymous namespace)::a_function()
1031 (anonymous namespace)::b_function()
1033 ** GDB now has much improved linespec and explicit locations TAB
1034 completion support, that better understands what you're
1035 completing and offers better suggestions. For example, GDB no
1036 longer offers data symbols as possible completions when you're
1037 setting a breakpoint.
1039 ** GDB now TAB-completes label symbol names.
1041 ** The "complete" command now mimics TAB completion accurately.
1043 * New command line options (gcore)
1046 Dump all memory mappings.
1048 * Breakpoints on C++ functions are now set on all scopes by default
1050 By default, breakpoints on functions/methods are now interpreted as
1051 specifying all functions with the given name ignoring missing
1052 leading scopes (namespaces and classes).
1054 For example, assuming a C++ program with symbols named:
1059 both commands "break func()" and "break B::func()" set a breakpoint
1062 You can use the new flag "-qualified" to override this. This makes
1063 GDB interpret the specified function name as a complete
1064 fully-qualified name instead. For example, using the same C++
1065 program, the "break -q B::func" command sets a breakpoint on
1066 "B::func", only. A parameter has been added to the Python
1067 gdb.Breakpoint constructor to achieve the same result when creating
1068 a breakpoint from Python.
1070 * Breakpoints on functions marked with C++ ABI tags
1072 GDB can now set breakpoints on functions marked with C++ ABI tags
1073 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1074 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1076 Functions with a C++11 abi tag are demangled/displayed like this:
1078 function[abi:cxx11](int)
1081 You can now set a breakpoint on such functions simply as if they had
1084 (gdb) b function(int)
1086 Or if you need to disambiguate between tags, like:
1088 (gdb) b function[abi:other_tag](int)
1090 Tab completion was adjusted accordingly as well.
1094 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1095 gdb.new_thread are emitted. See the manual for further
1096 description of these.
1098 ** A new function, "gdb.rbreak" has been added to the Python API.
1099 This function allows the setting of a large number of breakpoints
1100 via a regex pattern in Python. See the manual for further details.
1102 ** Python breakpoints can now accept explicit locations. See the
1103 manual for a further description of this feature.
1106 * New features in the GDB remote stub, GDBserver
1108 ** GDBserver is now able to start inferior processes with a
1109 specified initial working directory.
1111 The user can set the desired working directory to be used from
1112 GDB using the new "set cwd" command.
1114 ** New "--selftest" command line option runs some GDBserver self
1115 tests. These self tests are disabled in releases.
1117 ** On Unix systems, GDBserver now does globbing expansion and variable
1118 substitution in inferior command line arguments.
1120 This is done by starting inferiors using a shell, like GDB does.
1121 See "set startup-with-shell" in the user manual for how to disable
1122 this from GDB when using "target extended-remote". When using
1123 "target remote", you can disable the startup with shell by using the
1124 new "--no-startup-with-shell" GDBserver command line option.
1126 ** On Unix systems, GDBserver now supports receiving environment
1127 variables that are to be set or unset from GDB. These variables
1128 will affect the environment to be passed to the inferior.
1130 * When catching an Ada exception raised with a message, GDB now prints
1131 the message in the catchpoint hit notification. In GDB/MI mode, that
1132 information is provided as an extra field named "exception-message"
1133 in the *stopped notification.
1135 * Trait objects can now be inspected When debugging Rust code. This
1136 requires compiler support which will appear in Rust 1.24.
1138 * New remote packets
1140 QEnvironmentHexEncoded
1141 Inform GDBserver of an environment variable that is to be passed to
1142 the inferior when starting it.
1145 Inform GDBserver of an environment variable that is to be unset
1146 before starting the remote inferior.
1149 Inform GDBserver that the environment should be reset (i.e.,
1150 user-set environment variables should be unset).
1153 Indicates whether the inferior must be started with a shell or not.
1156 Tell GDBserver that the inferior to be started should use a specific
1159 * The "maintenance print c-tdesc" command now takes an optional
1160 argument which is the file name of XML target description.
1162 * The "maintenance selftest" command now takes an optional argument to
1163 filter the tests to be run.
1165 * The "enable", and "disable" commands now accept a range of
1166 breakpoint locations, e.g. "enable 1.3-5".
1171 Set and show the current working directory for the inferior.
1173 set|show compile-gcc
1174 Set and show compilation command used for compiling and injecting code
1175 with the 'compile' commands.
1177 set debug separate-debug-file
1178 show debug separate-debug-file
1179 Control the display of debug output about separate debug file search.
1181 set dump-excluded-mappings
1182 show dump-excluded-mappings
1183 Control whether mappings marked with the VM_DONTDUMP flag should be
1184 dumped when generating a core file.
1186 maint info selftests
1187 List the registered selftests.
1190 Start the debugged program stopping at the first instruction.
1193 Control display of debugging messages related to OpenRISC targets.
1195 set|show print type nested-type-limit
1196 Set and show the limit of nesting level for nested types that the
1197 type printer will show.
1199 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1202 * Safer/improved support for debugging with no debug info
1204 GDB no longer assumes functions with no debug information return
1207 This means that GDB now refuses to call such functions unless you
1208 tell it the function's type, by either casting the call to the
1209 declared return type, or by casting the function to a function
1210 pointer of the right type, and calling that:
1212 (gdb) p getenv ("PATH")
1213 'getenv' has unknown return type; cast the call to its declared return type
1214 (gdb) p (char *) getenv ("PATH")
1215 $1 = 0x7fffffffe "/usr/local/bin:/"...
1216 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1217 $2 = 0x7fffffffe "/usr/local/bin:/"...
1219 Similarly, GDB no longer assumes that global variables with no debug
1220 info have type 'int', and refuses to print the variable's value
1221 unless you tell it the variable's type:
1224 'var' has unknown type; cast it to its declared type
1228 * New native configurations
1230 FreeBSD/aarch64 aarch64*-*-freebsd*
1231 FreeBSD/arm arm*-*-freebsd*
1235 FreeBSD/aarch64 aarch64*-*-freebsd*
1236 FreeBSD/arm arm*-*-freebsd*
1237 OpenRISC ELF or1k*-*-elf
1239 * Removed targets and native configurations
1241 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1243 *** Changes in GDB 8.0
1245 * GDB now supports access to the PKU register on GNU/Linux. The register is
1246 added by the Memory Protection Keys for Userspace feature which will be
1247 available in future Intel CPUs.
1249 * GDB now supports C++11 rvalue references.
1253 ** New functions to start, stop and access a running btrace recording.
1254 ** Rvalue references are now supported in gdb.Type.
1256 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1259 * Building GDB and GDBserver now requires a C++11 compiler.
1261 For example, GCC 4.8 or later.
1263 It is no longer possible to build GDB or GDBserver with a C
1264 compiler. The --disable-build-with-cxx configure option has been
1267 * Building GDB and GDBserver now requires GNU make >= 3.81.
1269 It is no longer supported to build GDB or GDBserver with another
1270 implementation of the make program or an earlier version of GNU make.
1272 * Native debugging on MS-Windows supports command-line redirection
1274 Command-line arguments used for starting programs on MS-Windows can
1275 now include redirection symbols supported by native Windows shells,
1276 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1277 as "run", "start", and "set args", as well as the corresponding MI
1280 * Support for thread names on MS-Windows.
1282 GDB now catches and handles the special exception that programs
1283 running on MS-Windows use to assign names to threads in the
1286 * Support for Java programs compiled with gcj has been removed.
1288 * User commands now accept an unlimited number of arguments.
1289 Previously, only up to 10 was accepted.
1291 * The "eval" command now expands user-defined command arguments.
1293 This makes it easier to process a variable number of arguments:
1298 eval "print $arg%d", $i
1303 * Target descriptions can now describe registers for sparc32 and sparc64.
1305 * GDB now supports DWARF version 5 (debug information format).
1306 Its .debug_names index is not yet supported.
1308 * New native configurations
1310 FreeBSD/mips mips*-*-freebsd
1314 Synopsys ARC arc*-*-elf32
1315 FreeBSD/mips mips*-*-freebsd
1317 * Removed targets and native configurations
1319 Alpha running FreeBSD alpha*-*-freebsd*
1320 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1325 Erases all the flash memory regions reported by the target.
1327 maint print arc arc-instruction address
1328 Print internal disassembler information about instruction at a given address.
1332 set disassembler-options
1333 show disassembler-options
1334 Controls the passing of target specific information to the disassembler.
1335 If it is necessary to specify more than one disassembler option then
1336 multiple options can be placed together into a comma separated list.
1337 The default value is the empty string. Currently, the only supported
1338 targets are ARM, PowerPC and S/390.
1343 Erases all the flash memory regions reported by the target. This is
1344 equivalent to the CLI command flash-erase.
1346 -file-list-shared-libraries
1347 List the shared libraries in the program. This is
1348 equivalent to the CLI command "info shared".
1351 Catchpoints stopping the program when Ada exceptions are
1352 handled. This is equivalent to the CLI command "catch handlers".
1354 *** Changes in GDB 7.12
1356 * GDB and GDBserver now build with a C++ compiler by default.
1358 The --enable-build-with-cxx configure option is now enabled by
1359 default. One must now explicitly configure with
1360 --disable-build-with-cxx in order to build with a C compiler. This
1361 option will be removed in a future release.
1363 * GDBserver now supports recording btrace without maintaining an active
1366 * GDB now supports a negative repeat count in the 'x' command to examine
1367 memory backward from the given address. For example:
1370 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1371 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1372 (gdb) x/-5i 0x0000000000400580
1373 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1374 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1375 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1376 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1377 0x40057b <main(int, char**)+25>:
1378 callq 0x400536 <Func1(int, char const*)>
1380 * Fortran: Support structures with fields of dynamic types and
1381 arrays of dynamic types.
1383 * The symbol dumping maintenance commands have new syntax.
1384 maint print symbols [-pc address] [--] [filename]
1385 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1386 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1387 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1388 maint print msymbols [-objfile objfile] [--] [filename]
1390 * GDB now supports multibit bitfields and enums in target register
1393 * New Python-based convenience function $_as_string(val), which returns
1394 the textual representation of a value. This function is especially
1395 useful to obtain the text label of an enum value.
1397 * Intel MPX bound violation handling.
1399 Segmentation faults caused by a Intel MPX boundary violation
1400 now display the kind of violation (upper or lower), the memory
1401 address accessed and the memory bounds, along with the usual
1402 signal received and code location.
1406 Program received signal SIGSEGV, Segmentation fault
1407 Upper bound violation while accessing address 0x7fffffffc3b3
1408 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1409 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1411 * Rust language support.
1412 GDB now supports debugging programs written in the Rust programming
1413 language. See https://www.rust-lang.org/ for more information about
1416 * Support for running interpreters on specified input/output devices
1418 GDB now supports a new mechanism that allows frontends to provide
1419 fully featured GDB console views, as a better alternative to
1420 building such views on top of the "-interpreter-exec console"
1421 command. See the new "new-ui" command below. With that command,
1422 frontends can now start GDB in the traditional command-line mode
1423 running in an embedded terminal emulator widget, and create a
1424 separate MI interpreter running on a specified i/o device. In this
1425 way, GDB handles line editing, history, tab completion, etc. in the
1426 console all by itself, and the GUI uses the separate MI interpreter
1427 for its own control and synchronization, invisible to the command
1430 * The "catch syscall" command catches groups of related syscalls.
1432 The "catch syscall" command now supports catching a group of related
1433 syscalls using the 'group:' or 'g:' prefix.
1438 skip -gfile file-glob-pattern
1439 skip -function function
1440 skip -rfunction regular-expression
1441 A generalized form of the skip command, with new support for
1442 glob-style file names and regular expressions for function names.
1443 Additionally, a file spec and a function spec may now be combined.
1445 maint info line-table REGEXP
1446 Display the contents of GDB's internal line table data structure.
1449 Run any GDB unit tests that were compiled in.
1452 Start a new user interface instance running INTERP as interpreter,
1453 using the TTY file for input/output.
1457 ** gdb.Breakpoint objects have a new attribute "pending", which
1458 indicates whether the breakpoint is pending.
1459 ** Three new breakpoint-related events have been added:
1460 gdb.breakpoint_created, gdb.breakpoint_modified, and
1461 gdb.breakpoint_deleted.
1463 signal-event EVENTID
1464 Signal ("set") the given MS-Windows event object. This is used in
1465 conjunction with the Windows JIT debugging (AeDebug) support, where
1466 the OS suspends a crashing process until a debugger can attach to
1467 it. Resuming the crashing process, in order to debug it, is done by
1468 signalling an event.
1470 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1471 was added in GDBserver, including JIT compiling fast tracepoint's
1472 conditional expression bytecode into native code.
1474 * Support for various remote target protocols and ROM monitors has
1477 target m32rsdi Remote M32R debugging over SDI
1478 target mips MIPS remote debugging protocol
1479 target pmon PMON ROM monitor
1480 target ddb NEC's DDB variant of PMON for Vr4300
1481 target rockhopper NEC RockHopper variant of PMON
1482 target lsi LSI variant of PMO
1484 * Support for tracepoints and fast tracepoints on powerpc-linux,
1485 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1486 including JIT compiling fast tracepoint's conditional expression
1487 bytecode into native code.
1489 * MI async record =record-started now includes the method and format used for
1490 recording. For example:
1492 =record-started,thread-group="i1",method="btrace",format="bts"
1494 * MI async record =thread-selected now includes the frame field. For example:
1496 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1500 Andes NDS32 nds32*-*-elf
1502 *** Changes in GDB 7.11
1504 * GDB now supports debugging kernel-based threads on FreeBSD.
1506 * Per-inferior thread numbers
1508 Thread numbers are now per inferior instead of global. If you're
1509 debugging multiple inferiors, GDB displays thread IDs using a
1510 qualified INF_NUM.THR_NUM form. For example:
1514 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1515 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1516 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1517 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1519 As consequence, thread numbers as visible in the $_thread
1520 convenience variable and in Python's InferiorThread.num attribute
1521 are no longer unique between inferiors.
1523 GDB now maintains a second thread ID per thread, referred to as the
1524 global thread ID, which is the new equivalent of thread numbers in
1525 previous releases. See also $_gthread below.
1527 For backwards compatibility, MI's thread IDs always refer to global
1530 * Commands that accept thread IDs now accept the qualified
1531 INF_NUM.THR_NUM form as well. For example:
1534 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1537 * In commands that accept a list of thread IDs, you can now refer to
1538 all threads of an inferior using a star wildcard. GDB accepts
1539 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1540 refer to all threads of the current inferior. For example, "info
1543 * You can use "info threads -gid" to display the global thread ID of
1546 * The new convenience variable $_gthread holds the global number of
1549 * The new convenience variable $_inferior holds the number of the
1552 * GDB now displays the ID and name of the thread that hit a breakpoint
1553 or received a signal, if your program is multi-threaded. For
1556 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1557 Thread 1 "main" received signal SIGINT, Interrupt.
1559 * Record btrace now supports non-stop mode.
1561 * Support for tracepoints on aarch64-linux was added in GDBserver.
1563 * The 'record instruction-history' command now indicates speculative execution
1564 when using the Intel Processor Trace recording format.
1566 * GDB now allows users to specify explicit locations, bypassing
1567 the linespec parser. This feature is also available to GDB/MI
1570 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1571 GDB now is able to debug both AArch64 applications and ARM applications
1574 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1575 including JIT compiling fast tracepoint's conditional expression bytecode
1578 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1580 * "info threads", "info inferiors", "info display", "info checkpoints"
1581 and "maint info program-spaces" now list the corresponding items in
1582 ascending ID order, for consistency with all other "info" commands.
1584 * In Ada, the overloads selection menu has been enhanced to display the
1585 parameter types and the return types for the matching overloaded subprograms.
1589 maint set target-non-stop (on|off|auto)
1590 maint show target-non-stop
1591 Control whether GDB targets always operate in non-stop mode even if
1592 "set non-stop" is "off". The default is "auto", meaning non-stop
1593 mode is enabled if supported by the target.
1595 maint set bfd-sharing
1596 maint show bfd-sharing
1597 Control the reuse of bfd objects.
1600 show debug bfd-cache
1601 Control display of debugging info regarding bfd caching.
1605 Control display of debugging info regarding FreeBSD threads.
1607 set remote multiprocess-extensions-packet
1608 show remote multiprocess-extensions-packet
1609 Set/show the use of the remote protocol multiprocess extensions.
1611 set remote thread-events
1612 show remote thread-events
1613 Set/show the use of thread create/exit events.
1615 set ada print-signatures on|off
1616 show ada print-signatures"
1617 Control whether parameter types and return types are displayed in overloads
1618 selection menus. It is activated (@code{on}) by default.
1622 Controls the maximum size of memory, in bytes, that GDB will
1623 allocate for value contents. Prevents incorrect programs from
1624 causing GDB to allocate overly large buffers. Default is 64k.
1626 * The "disassemble" command accepts a new modifier: /s.
1627 It prints mixed source+disassembly like /m with two differences:
1628 - disassembled instructions are now printed in program order, and
1629 - and source for all relevant files is now printed.
1630 The "/m" option is now considered deprecated: its "source-centric"
1631 output hasn't proved useful in practice.
1633 * The "record instruction-history" command accepts a new modifier: /s.
1634 It behaves exactly like /m and prints mixed source+disassembly.
1636 * The "set scheduler-locking" command supports a new mode "replay".
1637 It behaves like "off" in record mode and like "on" in replay mode.
1639 * Support for various ROM monitors has been removed:
1641 target dbug dBUG ROM monitor for Motorola ColdFire
1642 target picobug Motorola picobug monitor
1643 target dink32 DINK32 ROM monitor for PowerPC
1644 target m32r Renesas M32R/D ROM monitor
1645 target mon2000 mon2000 ROM monitor
1646 target ppcbug PPCBUG ROM monitor for PowerPC
1648 * Support for reading/writing memory and extracting values on architectures
1649 whose memory is addressable in units of any integral multiple of 8 bits.
1652 Allows to break when an Ada exception is handled.
1654 * New remote packets
1657 Indicates that an exec system call was executed.
1659 exec-events feature in qSupported
1660 The qSupported packet allows GDB to request support for exec
1661 events using the new 'gdbfeature' exec-event, and the qSupported
1662 response can contain the corresponding 'stubfeature'. Set and
1663 show commands can be used to display whether these features are enabled.
1666 Equivalent to interrupting with the ^C character, but works in
1669 thread created stop reason (T05 create:...)
1670 Indicates that the thread was just created and is stopped at entry.
1672 thread exit stop reply (w exitcode;tid)
1673 Indicates that the thread has terminated.
1676 Enables/disables thread create and exit event reporting. For
1677 example, this is used in non-stop mode when GDB stops a set of
1678 threads and synchronously waits for the their corresponding stop
1679 replies. Without exit events, if one of the threads exits, GDB
1680 would hang forever not knowing that it should no longer expect a
1681 stop for that same thread.
1684 Indicates that there are no resumed threads left in the target (all
1685 threads are stopped). The remote stub reports support for this stop
1686 reply to GDB's qSupported query.
1689 Enables/disables catching syscalls from the inferior process.
1690 The remote stub reports support for this packet to GDB's qSupported query.
1692 syscall_entry stop reason
1693 Indicates that a syscall was just called.
1695 syscall_return stop reason
1696 Indicates that a syscall just returned.
1698 * Extended-remote exec events
1700 ** GDB now has support for exec events on extended-remote Linux targets.
1701 For such targets with Linux kernels 2.5.46 and later, this enables
1702 follow-exec-mode and exec catchpoints.
1704 set remote exec-event-feature-packet
1705 show remote exec-event-feature-packet
1706 Set/show the use of the remote exec event feature.
1708 * Thread names in remote protocol
1710 The reply to qXfer:threads:read may now include a name attribute for each
1713 * Target remote mode fork and exec events
1715 ** GDB now has support for fork and exec events on target remote mode
1716 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1717 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1718 fork and exec catchpoints.
1720 * Remote syscall events
1722 ** GDB now has support for catch syscall on remote Linux targets,
1723 currently enabled on x86/x86_64 architectures.
1725 set remote catch-syscall-packet
1726 show remote catch-syscall-packet
1727 Set/show the use of the remote catch syscall feature.
1731 ** The -var-set-format command now accepts the zero-hexadecimal
1732 format. It outputs data in hexadecimal format with zero-padding on the
1737 ** gdb.InferiorThread objects have a new attribute "global_num",
1738 which refers to the thread's global thread ID. The existing
1739 "num" attribute now refers to the thread's per-inferior number.
1740 See "Per-inferior thread numbers" above.
1741 ** gdb.InferiorThread objects have a new attribute "inferior", which
1742 is the Inferior object the thread belongs to.
1744 *** Changes in GDB 7.10
1746 * Support for process record-replay and reverse debugging on aarch64*-linux*
1747 targets has been added. GDB now supports recording of A64 instruction set
1748 including advance SIMD instructions.
1750 * Support for Sun's version of the "stabs" debug file format has been removed.
1752 * GDB now honors the content of the file /proc/PID/coredump_filter
1753 (PID is the process ID) on GNU/Linux systems. This file can be used
1754 to specify the types of memory mappings that will be included in a
1755 corefile. For more information, please refer to the manual page of
1756 "core(5)". GDB also has a new command: "set use-coredump-filter
1757 on|off". It allows to set whether GDB will read the content of the
1758 /proc/PID/coredump_filter file when generating a corefile.
1760 * The "info os" command on GNU/Linux can now display information on
1762 "info os cpus" Listing of all cpus/cores on the system
1764 * GDB has two new commands: "set serial parity odd|even|none" and
1765 "show serial parity". These allows to set or show parity for the
1768 * The "info source" command now displays the producer string if it was
1769 present in the debug info. This typically includes the compiler version
1770 and may include things like its command line arguments.
1772 * The "info dll", an alias of the "info sharedlibrary" command,
1773 is now available on all platforms.
1775 * Directory names supplied to the "set sysroot" commands may be
1776 prefixed with "target:" to tell GDB to access shared libraries from
1777 the target system, be it local or remote. This replaces the prefix
1778 "remote:". The default sysroot has been changed from "" to
1779 "target:". "remote:" is automatically converted to "target:" for
1780 backward compatibility.
1782 * The system root specified by "set sysroot" will be prepended to the
1783 filename of the main executable (if reported to GDB as absolute by
1784 the operating system) when starting processes remotely, and when
1785 attaching to already-running local or remote processes.
1787 * GDB now supports automatic location and retrieval of executable
1788 files from remote targets. Remote debugging can now be initiated
1789 using only a "target remote" or "target extended-remote" command
1790 (no "set sysroot" or "file" commands are required). See "New remote
1793 * The "dump" command now supports verilog hex format.
1795 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1797 * On GNU/Linux, GDB and gdbserver are now able to access executable
1798 and shared library files without a "set sysroot" command when
1799 attaching to processes running in different mount namespaces from
1800 the debugger. This makes it possible to attach to processes in
1801 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1802 See "New remote packets" below.
1804 * The "tui reg" command now provides completion for all of the
1805 available register groups, including target specific groups.
1807 * The HISTSIZE environment variable is no longer read when determining
1808 the size of GDB's command history. GDB now instead reads the dedicated
1809 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1810 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1815 ** Memory ports can now be unbuffered.
1819 ** gdb.Objfile objects have a new attribute "username",
1820 which is the name of the objfile as specified by the user,
1821 without, for example, resolving symlinks.
1822 ** You can now write frame unwinders in Python.
1823 ** gdb.Type objects have a new method "optimized_out",
1824 returning optimized out gdb.Value instance of this type.
1825 ** gdb.Value objects have new methods "reference_value" and
1826 "const_value" which return a reference to the value and a
1827 "const" version of the value respectively.
1831 maint print symbol-cache
1832 Print the contents of the symbol cache.
1834 maint print symbol-cache-statistics
1835 Print statistics of symbol cache usage.
1837 maint flush-symbol-cache
1838 Flush the contents of the symbol cache.
1842 Start branch trace recording using Branch Trace Store (BTS) format.
1845 Evaluate expression by using the compiler and print result.
1849 Explicit commands for enabling and disabling tui mode.
1852 set mpx bound on i386 and amd64
1853 Support for bound table investigation on Intel MPX enabled applications.
1857 Start branch trace recording using Intel Processor Trace format.
1860 Print information about branch tracing internals.
1862 maint btrace packet-history
1863 Print the raw branch tracing data.
1865 maint btrace clear-packet-history
1866 Discard the stored raw branch tracing data.
1869 Discard all branch tracing data. It will be fetched and processed
1870 anew by the next "record" command.
1875 Renamed from "set debug dwarf2-die".
1876 show debug dwarf-die
1877 Renamed from "show debug dwarf2-die".
1879 set debug dwarf-read
1880 Renamed from "set debug dwarf2-read".
1881 show debug dwarf-read
1882 Renamed from "show debug dwarf2-read".
1884 maint set dwarf always-disassemble
1885 Renamed from "maint set dwarf2 always-disassemble".
1886 maint show dwarf always-disassemble
1887 Renamed from "maint show dwarf2 always-disassemble".
1889 maint set dwarf max-cache-age
1890 Renamed from "maint set dwarf2 max-cache-age".
1891 maint show dwarf max-cache-age
1892 Renamed from "maint show dwarf2 max-cache-age".
1894 set debug dwarf-line
1895 show debug dwarf-line
1896 Control display of debugging info regarding DWARF line processing.
1899 show max-completions
1900 Set the maximum number of candidates to be considered during
1901 completion. The default value is 200. This limit allows GDB
1902 to avoid generating large completion lists, the computation of
1903 which can cause the debugger to become temporarily unresponsive.
1905 set history remove-duplicates
1906 show history remove-duplicates
1907 Control the removal of duplicate history entries.
1909 maint set symbol-cache-size
1910 maint show symbol-cache-size
1911 Control the size of the symbol cache.
1913 set|show record btrace bts buffer-size
1914 Set and show the size of the ring buffer used for branch tracing in
1916 The obtained size may differ from the requested size. Use "info
1917 record" to see the obtained buffer size.
1919 set debug linux-namespaces
1920 show debug linux-namespaces
1921 Control display of debugging info regarding Linux namespaces.
1923 set|show record btrace pt buffer-size
1924 Set and show the size of the ring buffer used for branch tracing in
1925 Intel Processor Trace format.
1926 The obtained size may differ from the requested size. Use "info
1927 record" to see the obtained buffer size.
1929 maint set|show btrace pt skip-pad
1930 Set and show whether PAD packets are skipped when computing the
1933 * The command 'thread apply all' can now support new option '-ascending'
1934 to call its specified command for all threads in ascending order.
1936 * Python/Guile scripting
1938 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1939 special section named `.debug_gdb_scripts'.
1941 * New remote packets
1943 qXfer:btrace-conf:read
1944 Return the branch trace configuration for the current thread.
1946 Qbtrace-conf:bts:size
1947 Set the requested ring buffer size for branch tracing in BTS format.
1950 Enable Intel Processor Trace-based branch tracing for the current
1951 process. The remote stub reports support for this packet to GDB's
1954 Qbtrace-conf:pt:size
1955 Set the requested ring buffer size for branch tracing in Intel Processor
1959 Indicates a memory breakpoint instruction was executed, irrespective
1960 of whether it was GDB that planted the breakpoint or the breakpoint
1961 is hardcoded in the program. This is required for correct non-stop
1965 Indicates the target stopped for a hardware breakpoint. This is
1966 required for correct non-stop mode operation.
1969 Return information about files on the remote system.
1971 qXfer:exec-file:read
1972 Return the full absolute name of the file that was executed to
1973 create a process running on the remote system.
1976 Select the filesystem on which vFile: operations with filename
1977 arguments will operate. This is required for GDB to be able to
1978 access files on remote targets where the remote stub does not
1979 share a common filesystem with the inferior(s).
1982 Indicates that a fork system call was executed.
1985 Indicates that a vfork system call was executed.
1987 vforkdone stop reason
1988 Indicates that a vfork child of the specified process has executed
1989 an exec or exit, allowing the vfork parent to resume execution.
1991 fork-events and vfork-events features in qSupported
1992 The qSupported packet allows GDB to request support for fork and
1993 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1994 and the qSupported response can contain the corresponding
1995 'stubfeatures'. Set and show commands can be used to display
1996 whether these features are enabled.
1998 * Extended-remote fork events
2000 ** GDB now has support for fork events on extended-remote Linux
2001 targets. For targets with Linux kernels 2.5.60 and later, this
2002 enables follow-fork-mode and detach-on-fork for both fork and
2003 vfork, as well as fork and vfork catchpoints.
2005 * The info record command now shows the recording format and the
2006 branch tracing configuration for the current thread when using
2007 the btrace record target.
2008 For the BTS format, it shows the ring buffer size.
2010 * GDB now has support for DTrace USDT (Userland Static Defined
2011 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2013 * GDB now supports access to vector registers on S/390 GNU/Linux
2016 * Removed command line options
2018 -xdb HP-UX XDB compatibility mode.
2020 * Removed targets and native configurations
2022 HP/PA running HP-UX hppa*-*-hpux*
2023 Itanium running HP-UX ia64-*-hpux*
2025 * New configure options
2028 This configure option allows the user to build GDB with support for
2029 Intel Processor Trace (default: auto). This requires libipt.
2031 --with-libipt-prefix=PATH
2032 Specify the path to the version of libipt that GDB should use.
2033 $PATH/include should contain the intel-pt.h header and
2034 $PATH/lib should contain the libipt.so library.
2036 *** Changes in GDB 7.9.1
2040 ** Xmethods can now specify a result type.
2042 *** Changes in GDB 7.9
2044 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2048 ** You can now access frame registers from Python scripts.
2049 ** New attribute 'producer' for gdb.Symtab objects.
2050 ** gdb.Objfile objects have a new attribute "progspace",
2051 which is the gdb.Progspace object of the containing program space.
2052 ** gdb.Objfile objects have a new attribute "owner".
2053 ** gdb.Objfile objects have a new attribute "build_id",
2054 which is the build ID generated when the file was built.
2055 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2056 ** A new event "gdb.clear_objfiles" has been added, triggered when
2057 selecting a new file to debug.
2058 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2059 ** New function gdb.lookup_objfile.
2061 New events which are triggered when GDB modifies the state of the
2064 ** gdb.events.inferior_call_pre: Function call is about to be made.
2065 ** gdb.events.inferior_call_post: Function call has just been made.
2066 ** gdb.events.memory_changed: A memory location has been altered.
2067 ** gdb.events.register_changed: A register has been altered.
2069 * New Python-based convenience functions:
2071 ** $_caller_is(name [, number_of_frames])
2072 ** $_caller_matches(regexp [, number_of_frames])
2073 ** $_any_caller_is(name [, number_of_frames])
2074 ** $_any_caller_matches(regexp [, number_of_frames])
2076 * GDB now supports the compilation and injection of source code into
2077 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2078 to compile the source code to object code, and if successful, inject
2079 and execute that code within the current context of the inferior.
2080 Currently the C language is supported. The commands used to
2081 interface with this new feature are:
2083 compile code [-raw|-r] [--] [source code]
2084 compile file [-raw|-r] filename
2088 demangle [-l language] [--] name
2089 Demangle "name" in the specified language, or the current language
2090 if elided. This command is renamed from the "maint demangle" command.
2091 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2092 as "maint demangler-warning".
2094 queue-signal signal-name-or-number
2095 Queue a signal to be delivered to the thread when it is resumed.
2097 add-auto-load-scripts-directory directory
2098 Add entries to the list of directories from which to load auto-loaded
2101 maint print user-registers
2102 List all currently available "user" registers.
2104 compile code [-r|-raw] [--] [source code]
2105 Compile, inject, and execute in the inferior the executable object
2106 code produced by compiling the provided source code.
2108 compile file [-r|-raw] filename
2109 Compile and inject into the inferior the executable object code
2110 produced by compiling the source code stored in the filename
2113 * On resume, GDB now always passes the signal the program had stopped
2114 for to the thread the signal was sent to, even if the user changed
2115 threads before resuming. Previously GDB would often (but not
2116 always) deliver the signal to the thread that happens to be current
2119 * Conversely, the "signal" command now consistently delivers the
2120 requested signal to the current thread. GDB now asks for
2121 confirmation if the program had stopped for a signal and the user
2122 switched threads meanwhile.
2124 * "breakpoint always-inserted" modes "off" and "auto" merged.
2126 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2127 won't remove breakpoints from the target until all threads stop,
2128 even in non-stop mode. The "auto" mode has been removed, and "off"
2129 is now the default mode.
2133 set debug symbol-lookup
2134 show debug symbol-lookup
2135 Control display of debugging info regarding symbol lookup.
2139 ** The -list-thread-groups command outputs an exit-code field for
2140 inferiors that have exited.
2144 MIPS SDE mips*-sde*-elf*
2148 Support for these obsolete configurations has been removed.
2150 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2151 SGI Irix-5.x mips-*-irix5*
2152 SGI Irix-6.x mips-*-irix6*
2153 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2154 VAX running Ultrix vax-*-ultrix*
2156 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2157 and "assf"), have been removed. Use the "sharedlibrary" command, or
2158 its alias "share", instead.
2160 *** Changes in GDB 7.8
2162 * New command line options
2165 This is an alias for the --data-directory option.
2167 * GDB supports printing and modifying of variable length automatic arrays
2168 as specified in ISO C99.
2170 * The ARM simulator now supports instruction level tracing
2171 with or without disassembly.
2175 GDB now has support for scripting using Guile. Whether this is
2176 available is determined at configure time.
2177 Guile version 2.0 or greater is required.
2178 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2180 * New commands (for set/show, see "New options" below)
2184 Invoke CODE by passing it to the Guile interpreter.
2188 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2190 info auto-load guile-scripts [regexp]
2191 Print the list of automatically loaded Guile scripts.
2193 * The source command is now capable of sourcing Guile scripts.
2194 This feature is dependent on the debugger being built with Guile support.
2198 set print symbol-loading (off|brief|full)
2199 show print symbol-loading
2200 Control whether to print informational messages when loading symbol
2201 information for a file. The default is "full", but when debugging
2202 programs with large numbers of shared libraries the amount of output
2203 becomes less useful.
2205 set guile print-stack (none|message|full)
2206 show guile print-stack
2207 Show a stack trace when an error is encountered in a Guile script.
2209 set auto-load guile-scripts (on|off)
2210 show auto-load guile-scripts
2211 Control auto-loading of Guile script files.
2213 maint ada set ignore-descriptive-types (on|off)
2214 maint ada show ignore-descriptive-types
2215 Control whether the debugger should ignore descriptive types in Ada
2216 programs. The default is not to ignore the descriptive types. See
2217 the user manual for more details on descriptive types and the intended
2218 usage of this option.
2220 set auto-connect-native-target
2222 Control whether GDB is allowed to automatically connect to the
2223 native target for the run, attach, etc. commands when not connected
2224 to any target yet. See also "target native" below.
2226 set record btrace replay-memory-access (read-only|read-write)
2227 show record btrace replay-memory-access
2228 Control what memory accesses are allowed during replay.
2230 maint set target-async (on|off)
2231 maint show target-async
2232 This controls whether GDB targets operate in synchronous or
2233 asynchronous mode. Normally the default is asynchronous, if it is
2234 available; but this can be changed to more easily debug problems
2235 occurring only in synchronous mode.
2237 set mi-async (on|off)
2239 Control whether MI asynchronous mode is preferred. This supersedes
2240 "set target-async" of previous GDB versions.
2242 * "set target-async" is deprecated as a CLI option and is now an alias
2243 for "set mi-async" (only puts MI into async mode).
2245 * Background execution commands (e.g., "c&", "s&", etc.) are now
2246 possible ``out of the box'' if the target supports them. Previously
2247 the user would need to explicitly enable the possibility with the
2248 "set target-async on" command.
2250 * New features in the GDB remote stub, GDBserver
2252 ** New option --debug-format=option1[,option2,...] allows one to add
2253 additional text to each output. At present only timestamps
2254 are supported: --debug-format=timestamps.
2255 Timestamps can also be turned on with the
2256 "monitor set debug-format timestamps" command from GDB.
2258 * The 'record instruction-history' command now starts counting instructions
2259 at one. This also affects the instruction ranges reported by the
2260 'record function-call-history' command when given the /i modifier.
2262 * The command 'record function-call-history' supports a new modifier '/c' to
2263 indent the function names based on their call stack depth.
2264 The fields for the '/i' and '/l' modifier have been reordered.
2265 The source line range is now prefixed with 'at'.
2266 The instruction range is now prefixed with 'inst'.
2267 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2268 "record instruction-history" and "list" commands.
2270 * The ranges given as arguments to the 'record function-call-history' and
2271 'record instruction-history' commands are now inclusive.
2273 * The btrace record target now supports the 'record goto' command.
2274 For locations inside the execution trace, the back trace is computed
2275 based on the information stored in the execution trace.
2277 * The btrace record target supports limited reverse execution and replay.
2278 The target does not record data and therefore does not allow reading
2279 memory or registers.
2281 * The "catch syscall" command now works on s390*-linux* targets.
2283 * The "compare-sections" command is no longer specific to target
2284 remote. It now works with all targets.
2286 * All native targets are now consistently called "native".
2287 Consequently, the "target child", "target GNU", "target djgpp",
2288 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2289 commands have been replaced with "target native". The QNX/NTO port
2290 leaves the "procfs" target in place and adds a "native" target for
2291 consistency with other ports. The impact on users should be minimal
2292 as these commands previously either throwed an error, or were
2293 no-ops. The target's name is visible in the output of the following
2294 commands: "help target", "info target", "info files", "maint print
2297 * The "target native" command now connects to the native target. This
2298 can be used to launch native programs even when "set
2299 auto-connect-native-target" is set to off.
2301 * GDB now supports access to Intel MPX registers on GNU/Linux.
2303 * Support for Intel AVX-512 registers on GNU/Linux.
2304 Support displaying and modifying Intel AVX-512 registers
2305 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2307 * New remote packets
2309 qXfer:btrace:read's annex
2310 The qXfer:btrace:read packet supports a new annex 'delta' to read
2311 branch trace incrementally.
2315 ** Valid Python operations on gdb.Value objects representing
2316 structs/classes invoke the corresponding overloaded operators if
2318 ** New `Xmethods' feature in the Python API. Xmethods are
2319 additional methods or replacements for existing methods of a C++
2320 class. This feature is useful for those cases where a method
2321 defined in C++ source code could be inlined or optimized out by
2322 the compiler, making it unavailable to GDB.
2325 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2327 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2328 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2329 its alias "share", instead.
2331 * The commands "set remotebaud" and "show remotebaud" are no longer
2332 supported. Use "set serial baud" and "show serial baud" (respectively)
2337 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2338 target-async". The latter is left as a deprecated alias of the
2339 former for backward compatibility. If the target supports it,
2340 CLI background execution commands are now always possible by
2341 default, independently of whether the frontend stated a
2342 preference for asynchronous execution with "-gdb-set mi-async".
2343 Previously "-gdb-set target-async off" affected both MI execution
2344 commands and CLI execution commands.
2346 *** Changes in GDB 7.7
2348 * Improved support for process record-replay and reverse debugging on
2349 arm*-linux* targets. Support for thumb32 and syscall instruction
2350 recording has been added.
2352 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2354 * GDB now supports Fission DWP file format version 2.
2355 http://gcc.gnu.org/wiki/DebugFission
2357 * New convenience function "$_isvoid", to check whether an expression
2358 is void. A void expression is an expression where the type of the
2359 result is "void". For example, some convenience variables may be
2360 "void" when evaluated (e.g., "$_exitcode" before the execution of
2361 the program being debugged; or an undefined convenience variable).
2362 Another example, when calling a function whose return type is
2365 * The "maintenance print objfiles" command now takes an optional regexp.
2367 * The "catch syscall" command now works on arm*-linux* targets.
2369 * GDB now consistently shows "<not saved>" when printing values of
2370 registers the debug info indicates have not been saved in the frame
2371 and there's nowhere to retrieve them from
2372 (callee-saved/call-clobbered registers):
2377 (gdb) info registers rax
2380 Before, the former would print "<optimized out>", and the latter
2381 "*value not available*".
2383 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2388 ** Frame filters and frame decorators have been added.
2389 ** Temporary breakpoints are now supported.
2390 ** Line tables representation has been added.
2391 ** New attribute 'parent_type' for gdb.Field objects.
2392 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2393 ** New attribute 'name' for gdb.Type objects.
2397 Nios II ELF nios2*-*-elf
2398 Nios II GNU/Linux nios2*-*-linux
2399 Texas Instruments MSP430 msp430*-*-elf
2401 * Removed native configurations
2403 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2404 been removed. ELF variants of these configurations are kept supported.
2406 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2407 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2408 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2409 i[34567]86-*-openbsd3.[0-3]
2410 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2411 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2412 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2416 Like "catch throw", but catches a re-thrown exception.
2417 maint check-psymtabs
2418 Renamed from old "maint check-symtabs".
2420 Perform consistency checks on symtabs.
2421 maint expand-symtabs
2422 Expand symtabs matching an optional regexp.
2425 Display the details of GDB configure-time options.
2427 maint set|show per-command
2428 maint set|show per-command space
2429 maint set|show per-command time
2430 maint set|show per-command symtab
2431 Enable display of per-command gdb resource usage.
2433 remove-symbol-file FILENAME
2434 remove-symbol-file -a ADDRESS
2435 Remove a symbol file added via add-symbol-file. The file to remove
2436 can be identified by its filename or by an address that lies within
2437 the boundaries of this symbol file in memory.
2440 info exceptions REGEXP
2441 Display the list of Ada exceptions defined in the program being
2442 debugged. If provided, only the exceptions whose names match REGEXP
2447 set debug symfile off|on
2449 Control display of debugging info regarding reading symbol files and
2450 symbol tables within those files
2452 set print raw frame-arguments
2453 show print raw frame-arguments
2454 Set/show whether to print frame arguments in raw mode,
2455 disregarding any defined pretty-printers.
2457 set remote trace-status-packet
2458 show remote trace-status-packet
2459 Set/show the use of remote protocol qTStatus packet.
2463 Control display of debugging messages related to Nios II targets.
2467 Control whether target-assisted range stepping is enabled.
2469 set startup-with-shell
2470 show startup-with-shell
2471 Specifies whether Unix child processes are started via a shell or
2476 Use the target memory cache for accesses to the code segment. This
2477 improves performance of remote debugging (particularly disassembly).
2479 * You can now use a literal value 'unlimited' for options that
2480 interpret 0 or -1 as meaning "unlimited". E.g., "set
2481 trace-buffer-size unlimited" is now an alias for "set
2482 trace-buffer-size -1" and "set height unlimited" is now an alias for
2485 * The "set debug symtab-create" debugging option of GDB has been changed to
2486 accept a verbosity level. 0 means "off", 1 provides basic debugging
2487 output, and values of 2 or greater provides more verbose output.
2489 * New command-line options
2491 Display the details of GDB configure-time options.
2493 * The command 'tsave' can now support new option '-ctf' to save trace
2494 buffer in Common Trace Format.
2496 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2499 * GDB now implements the C++ 'typeid' operator.
2501 * The new convenience variable $_exception holds the exception being
2502 thrown or caught at an exception-related catchpoint.
2504 * The exception-related catchpoints, like "catch throw", now accept a
2505 regular expression which can be used to filter exceptions by type.
2507 * The new convenience variable $_exitsignal is automatically set to
2508 the terminating signal number when the program being debugged dies
2509 due to an uncaught signal.
2513 ** All MI commands now accept an optional "--language" option.
2514 Support for this feature can be verified by using the "-list-features"
2515 command, which should contain "language-option".
2517 ** The new command -info-gdb-mi-command allows the user to determine
2518 whether a GDB/MI command is supported or not.
2520 ** The "^error" result record returned when trying to execute an undefined
2521 GDB/MI command now provides a variable named "code" whose content is the
2522 "undefined-command" error code. Support for this feature can be verified
2523 by using the "-list-features" command, which should contain
2524 "undefined-command-error-code".
2526 ** The -trace-save MI command can optionally save trace buffer in Common
2529 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2531 ** The command -data-list-register-values now accepts an optional
2532 "--skip-unavailable" option. When used, only the available registers
2535 ** The new command -trace-frame-collected dumps collected variables,
2536 computed expressions, tvars, memory and registers in a traceframe.
2538 ** The commands -stack-list-locals, -stack-list-arguments and
2539 -stack-list-variables now accept an option "--skip-unavailable".
2540 When used, only the available locals or arguments are displayed.
2542 ** The -exec-run command now accepts an optional "--start" option.
2543 When used, the command follows the same semantics as the "start"
2544 command, stopping the program's execution at the start of its
2545 main subprogram. Support for this feature can be verified using
2546 the "-list-features" command, which should contain
2547 "exec-run-start-option".
2549 ** The new commands -catch-assert and -catch-exceptions insert
2550 catchpoints stopping the program when Ada exceptions are raised.
2552 ** The new command -info-ada-exceptions provides the equivalent of
2553 the new "info exceptions" command.
2555 * New system-wide configuration scripts
2556 A GDB installation now provides scripts suitable for use as system-wide
2557 configuration scripts for the following systems:
2561 * GDB now supports target-assigned range stepping with remote targets.
2562 This improves the performance of stepping source lines by reducing
2563 the number of control packets from/to GDB. See "New remote packets"
2566 * GDB now understands the element 'tvar' in the XML traceframe info.
2567 It has the id of the collected trace state variables.
2569 * On S/390 targets that provide the transactional-execution feature,
2570 the program interruption transaction diagnostic block (TDB) is now
2571 represented as a number of additional "registers" in GDB.
2573 * New remote packets
2577 The vCont packet supports a new 'r' action, that tells the remote
2578 stub to step through an address range itself, without GDB
2579 involvemement at each single-step.
2581 qXfer:libraries-svr4:read's annex
2582 The previously unused annex of the qXfer:libraries-svr4:read packet
2583 is now used to support passing an argument list. The remote stub
2584 reports support for this argument list to GDB's qSupported query.
2585 The defined arguments are "start" and "prev", used to reduce work
2586 necessary for library list updating, resulting in significant
2589 * New features in the GDB remote stub, GDBserver
2591 ** GDBserver now supports target-assisted range stepping. Currently
2592 enabled on x86/x86_64 GNU/Linux targets.
2594 ** GDBserver now adds element 'tvar' in the XML in the reply to
2595 'qXfer:traceframe-info:read'. It has the id of the collected
2596 trace state variables.
2598 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2601 * New 'z' formatter for printing and examining memory, this displays the
2602 value as hexadecimal zero padded on the left to the size of the type.
2604 * GDB can now use Windows x64 unwinding data.
2606 * The "set remotebaud" command has been replaced by "set serial baud".
2607 Similarly, "show remotebaud" has been replaced by "show serial baud".
2608 The "set remotebaud" and "show remotebaud" commands are still available
2609 to provide backward compatibility with older versions of GDB.
2611 *** Changes in GDB 7.6
2613 * Target record has been renamed to record-full.
2614 Record/replay is now enabled with the "record full" command.
2615 This also affects settings that are associated with full record/replay
2616 that have been moved from "set/show record" to "set/show record full":
2618 set|show record full insn-number-max
2619 set|show record full stop-at-limit
2620 set|show record full memory-query
2622 * A new record target "record-btrace" has been added. The new target
2623 uses hardware support to record the control-flow of a process. It
2624 does not support replaying the execution, but it implements the
2625 below new commands for investigating the recorded execution log.
2626 This new recording method can be enabled using:
2630 The "record-btrace" target is only available on Intel Atom processors
2631 and requires a Linux kernel 2.6.32 or later.
2633 * Two new commands have been added for record/replay to give information
2634 about the recorded execution without having to replay the execution.
2635 The commands are only supported by "record btrace".
2637 record instruction-history prints the execution history at
2638 instruction granularity
2640 record function-call-history prints the execution history at
2641 function granularity
2643 * New native configurations
2645 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2646 FreeBSD/powerpc powerpc*-*-freebsd
2647 x86_64/Cygwin x86_64-*-cygwin*
2648 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2652 ARM AArch64 aarch64*-*-elf
2653 ARM AArch64 GNU/Linux aarch64*-*-linux
2654 Lynx 178 PowerPC powerpc-*-lynx*178
2655 x86_64/Cygwin x86_64-*-cygwin*
2656 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2658 * If the configured location of system.gdbinit file (as given by the
2659 --with-system-gdbinit option at configure time) is in the
2660 data-directory (as specified by --with-gdb-datadir at configure
2661 time) or in one of its subdirectories, then GDB will look for the
2662 system-wide init file in the directory specified by the
2663 --data-directory command-line option.
2665 * New command line options:
2667 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2668 other initialization files, unlike -nx which disables all of them.
2670 * Removed command line options
2672 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2675 * The 'ptype' and 'whatis' commands now accept an argument to control
2678 * 'info proc' now works on some core files.
2682 ** Vectors can be created with gdb.Type.vector.
2684 ** Python's atexit.register now works in GDB.
2686 ** Types can be pretty-printed via a Python API.
2688 ** Python 3 is now supported (in addition to Python 2.4 or later)
2690 ** New class gdb.Architecture exposes GDB's internal representation
2691 of architecture in the Python API.
2693 ** New method Frame.architecture returns the gdb.Architecture object
2694 corresponding to the frame's architecture.
2696 * New Python-based convenience functions:
2698 ** $_memeq(buf1, buf2, length)
2699 ** $_streq(str1, str2)
2701 ** $_regex(str, regex)
2703 * The 'cd' command now defaults to using '~' (the home directory) if not
2706 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2707 default for GCC since November 2000.
2709 * The command 'forward-search' can now be abbreviated as 'fo'.
2711 * The command 'info tracepoints' can now display 'installed on target'
2712 or 'not installed on target' for each non-pending location of tracepoint.
2714 * New configure options
2716 --enable-libmcheck/--disable-libmcheck
2717 By default, development versions are built with -lmcheck on hosts
2718 that support it, in order to help track memory corruption issues.
2719 Release versions, on the other hand, are built without -lmcheck
2720 by default. The --enable-libmcheck/--disable-libmcheck configure
2721 options allow the user to override that default.
2722 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2723 This configure option allows the user to build GDB with
2724 libbabeltrace using which GDB can read Common Trace Format data.
2726 * New commands (for set/show, see "New options" below)
2729 Catch signals. This is similar to "handle", but allows commands and
2730 conditions to be attached.
2733 List the BFDs known to GDB.
2735 python-interactive [command]
2737 Start a Python interactive prompt, or evaluate the optional command
2738 and print the result of expressions.
2741 "py" is a new alias for "python".
2743 enable type-printer [name]...
2744 disable type-printer [name]...
2745 Enable or disable type printers.
2749 ** For the Renesas Super-H architecture, the "regs" command has been removed
2750 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2755 set print type methods (on|off)
2756 show print type methods
2757 Control whether method declarations are displayed by "ptype".
2758 The default is to show them.
2760 set print type typedefs (on|off)
2761 show print type typedefs
2762 Control whether typedef definitions are displayed by "ptype".
2763 The default is to show them.
2765 set filename-display basename|relative|absolute
2766 show filename-display
2767 Control the way in which filenames is displayed.
2768 The default is "relative", which preserves previous behavior.
2770 set trace-buffer-size
2771 show trace-buffer-size
2772 Request target to change the size of trace buffer.
2774 set remote trace-buffer-size-packet auto|on|off
2775 show remote trace-buffer-size-packet
2776 Control the use of the remote protocol `QTBuffer:size' packet.
2780 Control display of debugging messages related to ARM AArch64.
2783 set debug coff-pe-read
2784 show debug coff-pe-read
2785 Control display of debugging messages related to reading of COFF/PE
2790 Control display of debugging messages related to Mach-O symbols
2793 set debug notification
2794 show debug notification
2795 Control display of debugging info for async remote notification.
2799 ** Command parameter changes are now notified using new async record
2800 "=cmd-param-changed".
2801 ** Trace frame changes caused by command "tfind" are now notified using
2802 new async record "=traceframe-changed".
2803 ** The creation, deletion and modification of trace state variables
2804 are now notified using new async records "=tsv-created",
2805 "=tsv-deleted" and "=tsv-modified".
2806 ** The start and stop of process record are now notified using new
2807 async record "=record-started" and "=record-stopped".
2808 ** Memory changes are now notified using new async record
2810 ** The data-disassemble command response will include a "fullname" field
2811 containing the absolute file name when source has been requested.
2812 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2813 command, to allow pattern filling of memory areas.
2814 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2815 library load/unload events.
2816 ** The response to breakpoint commands and breakpoint async records
2817 includes an "installed" field containing a boolean state about each
2818 non-pending tracepoint location is whether installed on target or not.
2819 ** Output of the "-trace-status" command includes a "trace-file" field
2820 containing the name of the trace file being examined. This field is
2821 optional, and only present when examining a trace file.
2822 ** The "fullname" field is now always present along with the "file" field,
2823 even if the file cannot be found by GDB.
2825 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2826 You must have the LZMA library available when configuring GDB for this
2827 feature to be enabled. For more information, see:
2828 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2830 * New remote packets
2833 Set the size of trace buffer. The remote stub reports support for this
2834 packet to gdb's qSupported query.
2837 Enable Branch Trace Store (BTS)-based branch tracing for the current
2838 thread. The remote stub reports support for this packet to gdb's
2842 Disable branch tracing for the current thread. The remote stub reports
2843 support for this packet to gdb's qSupported query.
2846 Read the traced branches for the current thread. The remote stub
2847 reports support for this packet to gdb's qSupported query.
2849 *** Changes in GDB 7.5
2851 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2852 for more x32 ABI info.
2854 * GDB now supports access to MIPS DSP registers on Linux targets.
2856 * GDB now supports debugging microMIPS binaries.
2858 * The "info os" command on GNU/Linux can now display information on
2859 several new classes of objects managed by the operating system:
2860 "info os procgroups" lists process groups
2861 "info os files" lists file descriptors
2862 "info os sockets" lists internet-domain sockets
2863 "info os shm" lists shared-memory regions
2864 "info os semaphores" lists semaphores
2865 "info os msg" lists message queues
2866 "info os modules" lists loaded kernel modules
2868 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2869 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2870 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2871 options and inspect the probe arguments using the new $_probe_arg family
2872 of convenience variables. You can obtain more information about SystemTap
2873 in <http://sourceware.org/systemtap/>.
2875 * GDB now supports reversible debugging on ARM, it allows you to
2876 debug basic ARM and THUMB instructions, and provides
2877 record/replay support.
2879 * The option "symbol-reloading" has been deleted as it is no longer used.
2883 ** GDB commands implemented in Python can now be put in command class
2886 ** The "maint set python print-stack on|off" is now deleted.
2888 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2889 apply "flag enum"-style pretty-printing to any enum.
2891 ** gdb.lookup_symbol can now work when there is no current frame.
2893 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2894 the source at which the symbol was defined.
2896 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2897 method 'value'. The former indicates whether the symbol needs a
2898 frame in order to compute its value, and the latter computes the
2901 ** A new method 'referenced_value' on gdb.Value objects which can
2902 dereference pointer as well as C++ reference values.
2904 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2905 which return the global and static blocks (as gdb.Block objects),
2906 of the underlying symbol table, respectively.
2908 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2909 object associated with a PC value.
2911 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2912 of the address range occupied by code for the current source line.
2914 * Go language support.
2915 GDB now supports debugging programs written in the Go programming
2918 * GDBserver now supports stdio connections.
2919 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2921 * The binary "gdbtui" can no longer be built or installed.
2922 Use "gdb -tui" instead.
2924 * GDB will now print "flag" enums specially. A flag enum is one where
2925 all the enumerator values have no bits in common when pairwise
2926 "and"ed. When printing a value whose type is a flag enum, GDB will
2927 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2928 (gdb) print (enum E) 3
2931 * The filename part of a linespec will now match trailing components
2932 of a source file name. For example, "break gcc/expr.c:1000" will
2933 now set a breakpoint in build/gcc/expr.c, but not
2934 build/libcpp/expr.c.
2936 * The "info proc" and "generate-core-file" commands will now also
2937 work on remote targets connected to GDBserver on Linux.
2939 * The command "info catch" has been removed. It has been disabled
2940 since December 2007.
2942 * The "catch exception" and "catch assert" commands now accept
2943 a condition at the end of the command, much like the "break"
2944 command does. For instance:
2946 (gdb) catch exception Constraint_Error if Barrier = True
2948 Previously, it was possible to add a condition to such catchpoints,
2949 but it had to be done as a second step, after the catchpoint had been
2950 created, using the "condition" command.
2952 * The "info static-tracepoint-marker" command will now also work on
2953 native Linux targets with in-process agent.
2955 * GDB can now set breakpoints on inlined functions.
2957 * The .gdb_index section has been updated to include symbols for
2958 inlined functions. GDB will ignore older .gdb_index sections by
2959 default, which could cause symbol files to be loaded more slowly
2960 until their .gdb_index sections can be recreated. The new command
2961 "set use-deprecated-index-sections on" will cause GDB to use any older
2962 .gdb_index sections it finds. This will restore performance, but the
2963 ability to set breakpoints on inlined functions will be lost in symbol
2964 files with older .gdb_index sections.
2966 The .gdb_index section has also been updated to record more information
2967 about each symbol. This speeds up the "info variables", "info functions"
2968 and "info types" commands when used with programs having the .gdb_index
2969 section, as well as speeding up debugging with shared libraries using
2970 the .gdb_index section.
2972 * Ada support for GDB/MI Variable Objects has been added.
2974 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2979 ** New command -info-os is the MI equivalent of "info os".
2981 ** Output logs ("set logging" and related) now include MI output.
2985 ** "set use-deprecated-index-sections on|off"
2986 "show use-deprecated-index-sections on|off"
2987 Controls the use of deprecated .gdb_index sections.
2989 ** "catch load" and "catch unload" can be used to stop when a shared
2990 library is loaded or unloaded, respectively.
2992 ** "enable count" can be used to auto-disable a breakpoint after
2995 ** "info vtbl" can be used to show the virtual method tables for
2996 C++ and Java objects.
2998 ** "explore" and its sub commands "explore value" and "explore type"
2999 can be used to recursively explore values and types of
3000 expressions. These commands are available only if GDB is
3001 configured with '--with-python'.
3003 ** "info auto-load" shows status of all kinds of auto-loaded files,
3004 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3005 sequences of commands files, "info auto-load python-scripts"
3006 shows status of auto-loading Python script files,
3007 "info auto-load local-gdbinit" shows status of loading init file
3008 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3009 status of inferior specific thread debugging shared library loading.
3011 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3012 and "show auto-load-scripts" commands have been deprecated, use their
3013 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3014 and "show auto-load python-scripts" counterparts instead.
3016 ** "dprintf location,format,args..." creates a dynamic printf, which
3017 is basically a breakpoint that does a printf and immediately
3018 resumes your program's execution, so it is like a printf that you
3019 can insert dynamically at runtime instead of at compiletime.
3021 ** "set print symbol"
3023 Controls whether GDB attempts to display the symbol, if any,
3024 corresponding to addresses it prints. This defaults to "on", but
3025 you can set it to "off" to restore GDB's previous behavior.
3027 * Deprecated commands
3029 ** For the Renesas Super-H architecture, the "regs" command has been
3030 deprecated, and "info all-registers" should be used instead.
3034 Renesas RL78 rl78-*-elf
3035 HP OpenVMS ia64 ia64-hp-openvms*
3037 * GDBserver supports evaluation of breakpoint conditions. When
3038 support is advertised by GDBserver, GDB may be told to send the
3039 breakpoint conditions in bytecode form to GDBserver. GDBserver
3040 will only report the breakpoint trigger to GDB when its condition
3045 set mips compression
3046 show mips compression
3047 Select the compressed ISA encoding used in functions that have no symbol
3048 information available. The encoding can be set to either of:
3051 and is updated automatically from ELF file flags if available.
3053 set breakpoint condition-evaluation
3054 show breakpoint condition-evaluation
3055 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3056 GDBserver ("target"). Default option "auto" chooses the most efficient
3058 This option can improve debugger efficiency depending on the speed of the
3062 Disable auto-loading globally.
3065 Show auto-loading setting of all kinds of auto-loaded files.
3067 set auto-load gdb-scripts on|off
3068 show auto-load gdb-scripts
3069 Control auto-loading of GDB canned sequences of commands files.
3071 set auto-load python-scripts on|off
3072 show auto-load python-scripts
3073 Control auto-loading of Python script files.
3075 set auto-load local-gdbinit on|off
3076 show auto-load local-gdbinit
3077 Control loading of init file (.gdbinit) from current directory.
3079 set auto-load libthread-db on|off
3080 show auto-load libthread-db
3081 Control auto-loading of inferior specific thread debugging shared library.
3083 set auto-load scripts-directory <dir1>[:<dir2>...]
3084 show auto-load scripts-directory
3085 Set a list of directories from which to load auto-loaded scripts.
3086 Automatically loaded Python scripts and GDB scripts are located in one
3087 of the directories listed by this option.
3088 The delimiter (':' above) may differ according to the host platform.
3090 set auto-load safe-path <dir1>[:<dir2>...]
3091 show auto-load safe-path
3092 Set a list of directories from which it is safe to auto-load files.
3093 The delimiter (':' above) may differ according to the host platform.
3095 set debug auto-load on|off
3096 show debug auto-load
3097 Control display of debugging info for auto-loading the files above.
3099 set dprintf-style gdb|call|agent
3101 Control the way in which a dynamic printf is performed; "gdb"
3102 requests a GDB printf command, while "call" causes dprintf to call a
3103 function in the inferior. "agent" requests that the target agent
3104 (such as GDBserver) do the printing.
3106 set dprintf-function <expr>
3107 show dprintf-function
3108 set dprintf-channel <expr>
3109 show dprintf-channel
3110 Set the function and optional first argument to the call when using
3111 the "call" style of dynamic printf.
3113 set disconnected-dprintf on|off
3114 show disconnected-dprintf
3115 Control whether agent-style dynamic printfs continue to be in effect
3116 after GDB disconnects.
3118 * New configure options
3120 --with-auto-load-dir
3121 Configure default value for the 'set auto-load scripts-directory'
3122 setting above. It defaults to '$debugdir:$datadir/auto-load',
3123 $debugdir representing global debugging info directories (available
3124 via 'show debug-file-directory') and $datadir representing GDB's data
3125 directory (available via 'show data-directory').
3127 --with-auto-load-safe-path
3128 Configure default value for the 'set auto-load safe-path' setting
3129 above. It defaults to the --with-auto-load-dir setting.
3131 --without-auto-load-safe-path
3132 Set 'set auto-load safe-path' to '/', effectively disabling this
3135 * New remote packets
3137 z0/z1 conditional breakpoints extension
3139 The z0/z1 breakpoint insertion packets have been extended to carry
3140 a list of conditional expressions over to the remote stub depending on the
3141 condition evaluation mode. The use of this extension can be controlled
3142 via the "set remote conditional-breakpoints-packet" command.
3146 Specify the signals which the remote stub may pass to the debugged
3147 program without GDB involvement.
3149 * New command line options
3151 --init-command=FILE, -ix Like --command, -x but execute it
3152 before loading inferior.
3153 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3154 execute it before loading inferior.
3156 *** Changes in GDB 7.4
3158 * GDB now handles ambiguous linespecs more consistently; the existing
3159 FILE:LINE support has been expanded to other types of linespecs. A
3160 breakpoint will now be set on all matching locations in all
3161 inferiors, and locations will be added or removed according to
3164 * GDB now allows you to skip uninteresting functions and files when
3165 stepping with the "skip function" and "skip file" commands.
3167 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3168 and "show remote hardware-watchpoint-length-limit". These allows to
3169 set or show the maximum length limit (in bytes) of a remote
3170 target hardware watchpoint.
3172 This allows e.g. to use "unlimited" hardware watchpoints with the
3173 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3174 watchpoints are slower than real hardware watchpoints but are
3175 significantly faster than gdb software watchpoints.
3179 ** The register_pretty_printer function in module gdb.printing now takes
3180 an optional `replace' argument. If True, the new printer replaces any
3183 ** The "maint set python print-stack on|off" command has been
3184 deprecated and will be deleted in GDB 7.5.
3185 A new command: "set python print-stack none|full|message" has
3186 replaced it. Additionally, the default for "print-stack" is
3187 now "message", which just prints the error message without
3190 ** A prompt substitution hook (prompt_hook) is now available to the
3193 ** A new Python module, gdb.prompt has been added to the GDB Python
3194 modules library. This module provides functionality for
3195 escape sequences in prompts (used by set/show
3196 extended-prompt). These escape sequences are replaced by their
3197 corresponding value.
3199 ** Python commands and convenience-functions located in
3200 'data-directory'/python/gdb/command and
3201 'data-directory'/python/gdb/function are now automatically loaded
3204 ** Blocks now provide four new attributes. global_block and
3205 static_block will return the global and static blocks
3206 respectively. is_static and is_global are boolean attributes
3207 that indicate if the block is one of those two types.
3209 ** Symbols now provide the "type" attribute, the type of the symbol.
3211 ** The "gdb.breakpoint" function has been deprecated in favor of
3214 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3215 of a function. This class is based on the "finish" command
3216 available in the CLI.
3218 ** Type objects for struct and union types now allow access to
3219 the fields using standard Python dictionary (mapping) methods.
3220 For example, "some_type['myfield']" now works, as does
3221 "some_type.items()".
3223 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3226 ** A new function, "deep_items" has been added to the gdb.types
3227 module in the GDB Python modules library. This function returns
3228 an iterator over the fields of a struct or union type. Unlike
3229 the standard Python "iteritems" method, it will recursively traverse
3230 any anonymous fields.
3234 ** "*stopped" events can report several new "reason"s, such as
3237 ** Breakpoint changes are now notified using new async records, like
3238 "=breakpoint-modified".
3240 ** New command -ada-task-info.
3242 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3243 $sdir specifies the default system locations of shared libraries.
3244 $pdir specifies the directory where the libpthread used by the application
3247 GDB no longer looks in $sdir and $pdir after it has searched the directories
3248 mentioned in libthread-db-search-path. If you want to search those
3249 directories, they must be specified in libthread-db-search-path.
3250 The default value of libthread-db-search-path on GNU/Linux and Solaris
3251 systems is now "$sdir:$pdir".
3253 $pdir is not supported by gdbserver, it is currently ignored.
3254 $sdir is supported by gdbserver.
3256 * New configure option --with-iconv-bin.
3257 When using the internationalization support like the one in the GNU C
3258 library, GDB will invoke the "iconv" program to get a list of supported
3259 character sets. If this program lives in a non-standard location, one can
3260 use this option to specify where to find it.
3262 * When natively debugging programs on PowerPC BookE processors running
3263 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3264 watchpoints, which specify a mask in addition to an address to watch.
3265 The mask specifies that some bits of an address (the bits which are
3266 reset in the mask) should be ignored when matching the address accessed
3267 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3268 section in the user manual for more details.
3270 * The new option --once causes GDBserver to stop listening for connections once
3271 the first connection is made. The listening port used by GDBserver will
3272 become available after that.
3274 * New commands "info macros" and "alias" have been added.
3276 * New function parameters suffix @entry specifies value of function parameter
3277 at the time the function got called. Entry values are available only since
3283 "!" is now an alias of the "shell" command.
3284 Note that no space is needed between "!" and SHELL COMMAND.
3288 watch EXPRESSION mask MASK_VALUE
3289 The watch command now supports the mask argument which allows creation
3290 of masked watchpoints, if the current architecture supports this feature.
3292 info auto-load-scripts [REGEXP]
3293 This command was formerly named "maintenance print section-scripts".
3294 It is now generally useful and is no longer a maintenance-only command.
3296 info macro [-all] [--] MACRO
3297 The info macro command has new options `-all' and `--'. The first for
3298 printing all definitions of a macro. The second for explicitly specifying
3299 the end of arguments and the beginning of the macro name in case the macro
3300 name starts with a hyphen.
3302 collect[/s] EXPRESSIONS
3303 The tracepoint collect command now takes an optional modifier "/s"
3304 that directs it to dereference pointer-to-character types and
3305 collect the bytes of memory up to a zero byte. The behavior is
3306 similar to what you see when you use the regular print command on a
3307 string. An optional integer following the "/s" sets a bound on the
3308 number of bytes that will be collected.
3311 The trace start command now interprets any supplied arguments as a
3312 note to be recorded with the trace run, with an effect similar to
3313 setting the variable trace-notes.
3316 The trace stop command now interprets any arguments as a note to be
3317 mentioned along with the tstatus report that the trace was stopped
3318 with a command. The effect is similar to setting the variable
3321 * Tracepoints can now be enabled and disabled at any time after a trace
3322 experiment has been started using the standard "enable" and "disable"
3323 commands. It is now possible to start a trace experiment with no enabled
3324 tracepoints; GDB will display a warning, but will allow the experiment to
3325 begin, assuming that tracepoints will be enabled as needed while the trace
3328 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3329 locations with 4-byte instructions, when they were previously
3330 limited to locations with instructions of 5 bytes or longer.
3334 set debug dwarf2-read
3335 show debug dwarf2-read
3336 Turns on or off display of debugging messages related to reading
3337 DWARF debug info. The default is off.
3339 set debug symtab-create
3340 show debug symtab-create
3341 Turns on or off display of debugging messages related to symbol table
3342 creation. The default is off.
3345 show extended-prompt
3346 Set the GDB prompt, and allow escape sequences to be inserted to
3347 display miscellaneous information (see 'help set extended-prompt'
3348 for the list of sequences). This prompt (and any information
3349 accessed through the escape sequences) is updated every time the
3350 prompt is displayed.
3352 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3353 show print entry-values
3354 Set printing of frame argument values at function entry. In some cases
3355 GDB can determine the value of function argument which was passed by the
3356 function caller, even if the value was modified inside the called function.
3358 set debug entry-values
3359 show debug entry-values
3360 Control display of debugging info for determining frame argument values at
3361 function entry and virtual tail call frames.
3363 set basenames-may-differ
3364 show basenames-may-differ
3365 Set whether a source file may have multiple base names.
3366 (A "base name" is the name of a file with the directory part removed.
3367 Example: The base name of "/home/user/hello.c" is "hello.c".)
3368 If set, GDB will canonicalize file names (e.g., expand symlinks)
3369 before comparing them. Canonicalization is an expensive operation,
3370 but it allows the same file be known by more than one base name.
3371 If not set (the default), all source files are assumed to have just
3372 one base name, and gdb will do file name comparisons more efficiently.
3378 Set a user name and notes for the current and any future trace runs.
3379 This is useful for long-running and/or disconnected traces, to
3380 inform others (or yourself) as to who is running the trace, supply
3381 contact information, or otherwise explain what is going on.
3383 set trace-stop-notes
3384 show trace-stop-notes
3385 Set a note attached to the trace run, that is displayed when the
3386 trace has been stopped by a tstop command. This is useful for
3387 instance as an explanation, if you are stopping a trace run that was
3388 started by someone else.
3390 * New remote packets
3394 Dynamically enable a tracepoint in a started trace experiment.
3398 Dynamically disable a tracepoint in a started trace experiment.
3402 Set the user and notes of the trace run.
3406 Query the current status of a tracepoint.
3410 Query the minimum length of instruction at which a fast tracepoint may
3413 * Dcache size (number of lines) and line-size are now runtime-configurable
3414 via "set dcache line" and "set dcache line-size" commands.
3418 Texas Instruments TMS320C6x tic6x-*-*
3422 Renesas RL78 rl78-*-elf
3424 *** Changes in GDB 7.3.1
3426 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3428 *** Changes in GDB 7.3
3430 * GDB has a new command: "thread find [REGEXP]".
3431 It finds the thread id whose name, target id, or thread extra info
3432 matches the given regular expression.
3434 * The "catch syscall" command now works on mips*-linux* targets.
3436 * The -data-disassemble MI command now supports modes 2 and 3 for
3437 dumping the instruction opcodes.
3439 * New command line options
3441 -data-directory DIR Specify DIR as the "data-directory".
3442 This is mostly for testing purposes.
3444 * The "maint set python auto-load on|off" command has been renamed to
3445 "set auto-load-scripts on|off".
3447 * GDB has a new command: "set directories".
3448 It is like the "dir" command except that it replaces the
3449 source path list instead of augmenting it.
3451 * GDB now understands thread names.
3453 On GNU/Linux, "info threads" will display the thread name as set by
3454 prctl or pthread_setname_np.
3456 There is also a new command, "thread name", which can be used to
3457 assign a name internally for GDB to display.
3460 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3461 has been integrated into GDB.
3465 ** The function gdb.Write now accepts an optional keyword 'stream'.
3466 This keyword, when provided, will direct the output to either
3467 stdout, stderr, or GDB's logging output.
3469 ** Parameters can now be be sub-classed in Python, and in particular
3470 you may implement the get_set_doc and get_show_doc functions.
3471 This improves how Parameter set/show documentation is processed
3472 and allows for more dynamic content.
3474 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3475 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3476 have an is_valid method.
3478 ** Breakpoints can now be sub-classed in Python, and in particular
3479 you may implement a 'stop' function that is executed each time
3480 the inferior reaches that breakpoint.
3482 ** New function gdb.lookup_global_symbol looks up a global symbol.
3484 ** GDB values in Python are now callable if the value represents a
3485 function. For example, if 'some_value' represents a function that
3486 takes two integer parameters and returns a value, you can call
3487 that function like so:
3489 result = some_value (10,20)
3491 ** Module gdb.types has been added.
3492 It contains a collection of utilities for working with gdb.Types objects:
3493 get_basic_type, has_field, make_enum_dict.
3495 ** Module gdb.printing has been added.
3496 It contains utilities for writing and registering pretty-printers.
3497 New classes: PrettyPrinter, SubPrettyPrinter,
3498 RegexpCollectionPrettyPrinter.
3499 New function: register_pretty_printer.
3501 ** New commands "info pretty-printers", "enable pretty-printer" and
3502 "disable pretty-printer" have been added.
3504 ** gdb.parameter("directories") is now available.
3506 ** New function gdb.newest_frame returns the newest frame in the
3509 ** The gdb.InferiorThread class has a new "name" attribute. This
3510 holds the thread's name.
3512 ** Python Support for Inferior events.
3513 Python scripts can add observers to be notified of events
3514 occurring in the process being debugged.
3515 The following events are currently supported:
3516 - gdb.events.cont Continue event.
3517 - gdb.events.exited Inferior exited event.
3518 - gdb.events.stop Signal received, and Breakpoint hit events.
3522 ** GDB now puts template parameters in scope when debugging in an
3523 instantiation. For example, if you have:
3525 template<int X> int func (void) { return X; }
3527 then if you step into func<5>, "print X" will show "5". This
3528 feature requires proper debuginfo support from the compiler; it
3529 was added to GCC 4.5.
3531 ** The motion commands "next", "finish", "until", and "advance" now
3532 work better when exceptions are thrown. In particular, GDB will
3533 no longer lose control of the inferior; instead, the GDB will
3534 stop the inferior at the point at which the exception is caught.
3535 This functionality requires a change in the exception handling
3536 code that was introduced in GCC 4.5.
3538 * GDB now follows GCC's rules on accessing volatile objects when
3539 reading or writing target state during expression evaluation.
3540 One notable difference to prior behavior is that "print x = 0"
3541 no longer generates a read of x; the value of the assignment is
3542 now always taken directly from the value being assigned.
3544 * GDB now has some support for using labels in the program's source in
3545 linespecs. For instance, you can use "advance label" to continue
3546 execution to a label.
3548 * GDB now has support for reading and writing a new .gdb_index
3549 section. This section holds a fast index of DWARF debugging
3550 information and can be used to greatly speed up GDB startup and
3551 operation. See the documentation for `save gdb-index' for details.
3553 * The "watch" command now accepts an optional "-location" argument.
3554 When used, this causes GDB to watch the memory referred to by the
3555 expression. Such a watchpoint is never deleted due to it going out
3558 * GDB now supports thread debugging of core dumps on GNU/Linux.
3560 GDB now activates thread debugging using the libthread_db library
3561 when debugging GNU/Linux core dumps, similarly to when debugging
3562 live processes. As a result, when debugging a core dump file, GDB
3563 is now able to display pthread_t ids of threads. For example, "info
3564 threads" shows the same output as when debugging the process when it
3565 was live. In earlier releases, you'd see something like this:
3568 * 1 LWP 6780 main () at main.c:10
3570 While now you see this:
3573 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3575 It is also now possible to inspect TLS variables when debugging core
3578 When debugging a core dump generated on a machine other than the one
3579 used to run GDB, you may need to point GDB at the correct
3580 libthread_db library with the "set libthread-db-search-path"
3581 command. See the user manual for more details on this command.
3583 * When natively debugging programs on PowerPC BookE processors running
3584 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3585 which stop execution of the inferior whenever it executes an instruction
3586 at any address within the specified range. See the "PowerPC Embedded"
3587 section in the user manual for more details.
3589 * New features in the GDB remote stub, GDBserver
3591 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3592 and i686 LynxOS (version 5.x).
3594 ** GDBserver is now supported on Blackfin Linux.
3596 * New native configurations
3598 ia64 HP-UX ia64-*-hpux*
3602 Analog Devices, Inc. Blackfin Processor bfin-*
3604 * Ada task switching is now supported on sparc-elf targets when
3605 debugging a program using the Ravenscar Profile. For more information,
3606 see the "Tasking Support when using the Ravenscar Profile" section
3607 in the GDB user manual.
3609 * Guile support was removed.
3611 * New features in the GNU simulator
3613 ** The --map-info flag lists all known core mappings.
3615 ** CFI flashes may be simulated via the "cfi" device.
3617 *** Changes in GDB 7.2
3619 * Shared library support for remote targets by default
3621 When GDB is configured for a generic, non-OS specific target, like
3622 for example, --target=arm-eabi or one of the many *-*-elf targets,
3623 GDB now queries remote stubs for loaded shared libraries using the
3624 `qXfer:libraries:read' packet. Previously, shared library support
3625 was always disabled for such configurations.
3629 ** Argument Dependent Lookup (ADL)
3631 In C++ ADL lookup directs function search to the namespaces of its
3632 arguments even if the namespace has not been imported.
3642 Here the compiler will search for `foo' in the namespace of 'b'
3643 and find A::foo. GDB now supports this. This construct is commonly
3644 used in the Standard Template Library for operators.
3646 ** Improved User Defined Operator Support
3648 In addition to member operators, GDB now supports lookup of operators
3649 defined in a namespace and imported with a `using' directive, operators
3650 defined in the global scope, operators imported implicitly from an
3651 anonymous namespace, and the ADL operators mentioned in the previous
3653 GDB now also supports proper overload resolution for all the previously
3654 mentioned flavors of operators.
3656 ** static const class members
3658 Printing of static const class members that are initialized in the
3659 class definition has been fixed.
3661 * Windows Thread Information Block access.
3663 On Windows targets, GDB now supports displaying the Windows Thread
3664 Information Block (TIB) structure. This structure is visible either
3665 by using the new command `info w32 thread-information-block' or, by
3666 dereferencing the new convenience variable named `$_tlb', a
3667 thread-specific pointer to the TIB. This feature is also supported
3668 when remote debugging using GDBserver.
3670 * Static tracepoints
3672 Static tracepoints are calls in the user program into a tracing
3673 library. One such library is a port of the LTTng kernel tracer to
3674 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3675 When debugging with GDBserver, GDB now supports combining the GDB
3676 tracepoint machinery with such libraries. For example: the user can
3677 use GDB to probe a static tracepoint marker (a call from the user
3678 program into the tracing library) with the new "strace" command (see
3679 "New commands" below). This creates a "static tracepoint" in the
3680 breakpoint list, that can be manipulated with the same feature set
3681 as fast and regular tracepoints. E.g., collect registers, local and
3682 global variables, collect trace state variables, and define
3683 tracepoint conditions. In addition, the user can collect extra
3684 static tracepoint marker specific data, by collecting the new
3685 $_sdata internal variable. When analyzing the trace buffer, you can
3686 inspect $_sdata like any other variable available to GDB. For more
3687 information, see the "Tracepoints" chapter in GDB user manual. New
3688 remote packets have been defined to support static tracepoints, see
3689 the "New remote packets" section below.
3691 * Better reconstruction of tracepoints after disconnected tracing
3693 GDB will attempt to download the original source form of tracepoint
3694 definitions when starting a trace run, and then will upload these
3695 upon reconnection to the target, resulting in a more accurate
3696 reconstruction of the tracepoints that are in use on the target.
3700 You can now exercise direct control over the ways that GDB can
3701 affect your program. For instance, you can disallow the setting of
3702 breakpoints, so that the program can run continuously (assuming
3703 non-stop mode). In addition, the "observer" variable is available
3704 to switch all of the different controls; in observer mode, GDB
3705 cannot affect the target's behavior at all, which is useful for
3706 tasks like diagnosing live systems in the field.
3708 * The new convenience variable $_thread holds the number of the
3711 * New remote packets
3715 Return the address of the Windows Thread Information Block of a given thread.
3719 In response to several of the tracepoint packets, the target may now
3720 also respond with a number of intermediate `qRelocInsn' request
3721 packets before the final result packet, to have GDB handle
3722 relocating an instruction to execute at a different address. This
3723 is particularly useful for stubs that support fast tracepoints. GDB
3724 reports support for this feature in the qSupported packet.
3728 List static tracepoint markers in the target program.
3732 List static tracepoint markers at a given address in the target
3735 qXfer:statictrace:read
3737 Read the static trace data collected (by a `collect $_sdata'
3738 tracepoint action). The remote stub reports support for this packet
3739 to gdb's qSupported query.
3743 Send the current settings of GDB's permission flags.
3747 Send part of the source (textual) form of a tracepoint definition,
3748 which includes location, conditional, and action list.
3750 * The source command now accepts a -s option to force searching for the
3751 script in the source search path even if the script name specifies
3754 * New features in the GDB remote stub, GDBserver
3756 - GDBserver now support tracepoints (including fast tracepoints, and
3757 static tracepoints). The feature is currently supported by the
3758 i386-linux and amd64-linux builds. See the "Tracepoints support
3759 in gdbserver" section in the manual for more information.
3761 GDBserver JIT compiles the tracepoint's conditional agent
3762 expression bytecode into native code whenever possible for low
3763 overhead dynamic tracepoints conditionals. For such tracepoints,
3764 an expression that examines program state is evaluated when the
3765 tracepoint is reached, in order to determine whether to capture
3766 trace data. If the condition is simple and false, processing the
3767 tracepoint finishes very quickly and no data is gathered.
3769 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3770 for static tracepoints support.
3772 - GDBserver now supports x86_64 Windows 64-bit debugging.
3774 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3775 it understands register description.
3777 * The --batch flag now disables pagination and queries.
3779 * X86 general purpose registers
3781 GDB now supports reading/writing byte, word and double-word x86
3782 general purpose registers directly. This means you can use, say,
3783 $ah or $ax to refer, respectively, to the byte register AH and
3784 16-bit word register AX that are actually portions of the 32-bit
3785 register EAX or 64-bit register RAX.
3787 * The `commands' command now accepts a range of breakpoints to modify.
3788 A plain `commands' following a command that creates multiple
3789 breakpoints affects all the breakpoints set by that command. This
3790 applies to breakpoints set by `rbreak', and also applies when a
3791 single `break' command creates multiple breakpoints (e.g.,
3792 breakpoints on overloaded c++ functions).
3794 * The `rbreak' command now accepts a filename specification as part of
3795 its argument, limiting the functions selected by the regex to those
3796 in the specified file.
3798 * Support for remote debugging Windows and SymbianOS shared libraries
3799 from Unix hosts has been improved. Non Windows GDB builds now can
3800 understand target reported file names that follow MS-DOS based file
3801 system semantics, such as file names that include drive letters and
3802 use the backslash character as directory separator. This makes it
3803 possible to transparently use the "set sysroot" and "set
3804 solib-search-path" on Unix hosts to point as host copies of the
3805 target's shared libraries. See the new command "set
3806 target-file-system-kind" described below, and the "Commands to
3807 specify files" section in the user manual for more information.
3811 eval template, expressions...
3812 Convert the values of one or more expressions under the control
3813 of the string template to a command line, and call it.
3815 set target-file-system-kind unix|dos-based|auto
3816 show target-file-system-kind
3817 Set or show the assumed file system kind for target reported file
3820 save breakpoints <filename>
3821 Save all current breakpoint definitions to a file suitable for use
3822 in a later debugging session. To read the saved breakpoint
3823 definitions, use the `source' command.
3825 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3828 info static-tracepoint-markers
3829 Display information about static tracepoint markers in the target.
3831 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3832 Define a static tracepoint by probing a marker at the given
3833 function, line, address, or marker ID.
3837 Enable and disable observer mode.
3839 set may-write-registers on|off
3840 set may-write-memory on|off
3841 set may-insert-breakpoints on|off
3842 set may-insert-tracepoints on|off
3843 set may-insert-fast-tracepoints on|off
3844 set may-interrupt on|off
3845 Set individual permissions for GDB effects on the target. Note that
3846 some of these settings can have undesirable or surprising
3847 consequences, particularly when changed in the middle of a session.
3848 For instance, disabling the writing of memory can prevent
3849 breakpoints from being inserted, cause single-stepping to fail, or
3850 even crash your program, if you disable after breakpoints have been
3851 inserted. However, GDB should not crash.
3853 set record memory-query on|off
3854 show record memory-query
3855 Control whether to stop the inferior if memory changes caused
3856 by an instruction cannot be recorded.
3861 The disassemble command now supports "start,+length" form of two arguments.
3865 ** GDB now provides a new directory location, called the python directory,
3866 where Python scripts written for GDB can be installed. The location
3867 of that directory is <data-directory>/python, where <data-directory>
3868 is the GDB data directory. For more details, see section `Scripting
3869 GDB using Python' in the manual.
3871 ** The GDB Python API now has access to breakpoints, symbols, symbol
3872 tables, program spaces, inferiors, threads and frame's code blocks.
3873 Additionally, GDB Parameters can now be created from the API, and
3874 manipulated via set/show in the CLI.
3876 ** New functions gdb.target_charset, gdb.target_wide_charset,
3877 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3879 ** New exception gdb.GdbError.
3881 ** Pretty-printers are now also looked up in the current program space.
3883 ** Pretty-printers can now be individually enabled and disabled.
3885 ** GDB now looks for names of Python scripts to auto-load in a
3886 special section named `.debug_gdb_scripts', in addition to looking
3887 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3889 * Tracepoint actions were unified with breakpoint commands. In particular,
3890 there are no longer differences in "info break" output for breakpoints and
3891 tracepoints and the "commands" command can be used for both tracepoints and
3892 regular breakpoints.
3896 ARM Symbian arm*-*-symbianelf*
3898 * D language support.
3899 GDB now supports debugging programs written in the D programming
3902 * GDB now supports the extended ptrace interface for PowerPC which is
3903 available since Linux kernel version 2.6.34. This automatically enables
3904 any hardware breakpoints and additional hardware watchpoints available in
3905 the processor. The old ptrace interface exposes just one hardware
3906 watchpoint and no hardware breakpoints.
3908 * GDB is now able to use the Data Value Compare (DVC) register available on
3909 embedded PowerPC processors to implement in hardware simple watchpoint
3910 conditions of the form:
3912 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3914 This works in native GDB running on Linux kernels with the extended ptrace
3915 interface mentioned above.
3917 *** Changes in GDB 7.1
3921 ** Namespace Support
3923 GDB now supports importing of namespaces in C++. This enables the
3924 user to inspect variables from imported namespaces. Support for
3925 namepace aliasing has also been added. So, if a namespace is
3926 aliased in the current scope (e.g. namepace C=A; ) the user can
3927 print variables using the alias (e.g. (gdb) print C::x).
3931 All known bugs relating to the printing of virtual base class were
3932 fixed. It is now possible to call overloaded static methods using a
3937 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3938 and reinterpret_cast<> are now handled by the C++ expression parser.
3942 Xilinx MicroBlaze microblaze-*-*
3947 Xilinx MicroBlaze microblaze
3950 * Multi-program debugging.
3952 GDB now has support for multi-program (a.k.a. multi-executable or
3953 multi-exec) debugging. This allows for debugging multiple inferiors
3954 simultaneously each running a different program under the same GDB
3955 session. See "Debugging Multiple Inferiors and Programs" in the
3956 manual for more information. This implied some user visible changes
3957 in the multi-inferior support. For example, "info inferiors" now
3958 lists inferiors that are not running yet or that have exited
3959 already. See also "New commands" and "New options" below.
3961 * New tracing features
3963 GDB's tracepoint facility now includes several new features:
3965 ** Trace state variables
3967 GDB tracepoints now include support for trace state variables, which
3968 are variables managed by the target agent during a tracing
3969 experiment. They are useful for tracepoints that trigger each
3970 other, so for instance one tracepoint can count hits in a variable,
3971 and then a second tracepoint has a condition that is true when the
3972 count reaches a particular value. Trace state variables share the
3973 $-syntax of GDB convenience variables, and can appear in both
3974 tracepoint actions and condition expressions. Use the "tvariable"
3975 command to create, and "info tvariables" to view; see "Trace State
3976 Variables" in the manual for more detail.
3980 GDB now includes an option for defining fast tracepoints, which
3981 targets may implement more efficiently, such as by installing a jump
3982 into the target agent rather than a trap instruction. The resulting
3983 speedup can be by two orders of magnitude or more, although the
3984 tradeoff is that some program locations on some target architectures
3985 might not allow fast tracepoint installation, for instance if the
3986 instruction to be replaced is shorter than the jump. To request a
3987 fast tracepoint, use the "ftrace" command, with syntax identical to
3988 the regular trace command.
3990 ** Disconnected tracing
3992 It is now possible to detach GDB from the target while it is running
3993 a trace experiment, then reconnect later to see how the experiment
3994 is going. In addition, a new variable disconnected-tracing lets you
3995 tell the target agent whether to continue running a trace if the
3996 connection is lost unexpectedly.
4000 GDB now has the ability to save the trace buffer into a file, and
4001 then use that file as a target, similarly to you can do with
4002 corefiles. You can select trace frames, print data that was
4003 collected in them, and use tstatus to display the state of the
4004 tracing run at the moment that it was saved. To create a trace
4005 file, use "tsave <filename>", and to use it, do "target tfile
4008 ** Circular trace buffer
4010 You can ask the target agent to handle the trace buffer as a
4011 circular buffer, discarding the oldest trace frames to make room for
4012 newer ones, by setting circular-trace-buffer to on. This feature may
4013 not be available for all target agents.
4018 The disassemble command, when invoked with two arguments, now requires
4019 the arguments to be comma-separated.
4022 The info variables command now displays variable definitions. Files
4023 which only declare a variable are not shown.
4026 The source command is now capable of sourcing Python scripts.
4027 This feature is dependent on the debugger being build with Python
4030 Related to this enhancement is also the introduction of a new command
4031 "set script-extension" (see below).
4033 * New commands (for set/show, see "New options" below)
4035 record save [<FILENAME>]
4036 Save a file (in core file format) containing the process record
4037 execution log for replay debugging at a later time.
4039 record restore <FILENAME>
4040 Restore the process record execution log that was saved at an
4041 earlier time, for replay debugging.
4043 add-inferior [-copies <N>] [-exec <FILENAME>]
4046 clone-inferior [-copies <N>] [ID]
4047 Make a new inferior ready to execute the same program another
4048 inferior has loaded.
4053 maint info program-spaces
4054 List the program spaces loaded into GDB.
4056 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4057 show remote interrupt-sequence
4058 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4059 as the sequence to the remote target in order to interrupt the execution.
4060 Ctrl-C is a default. Some system prefers BREAK which is high level of
4061 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4062 Magic SysRq g. It is BREAK signal and character 'g'.
4064 set remote interrupt-on-connect [on | off]
4065 show remote interrupt-on-connect
4066 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4067 remote target when gdb connects to it. This is needed when you debug
4070 set remotebreak [on | off]
4072 Deprecated. Use "set/show remote interrupt-sequence" instead.
4074 tvariable $NAME [ = EXP ]
4075 Create or modify a trace state variable.
4078 List trace state variables and their values.
4080 delete tvariable $NAME ...
4081 Delete one or more trace state variables.
4084 Evaluate the given expressions without collecting anything into the
4085 trace buffer. (Valid in tracepoint actions only.)
4087 ftrace FN / FILE:LINE / *ADDR
4088 Define a fast tracepoint at the given function, line, or address.
4090 * New expression syntax
4092 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4093 GDB now parses 0b101010 identically with 42.
4097 set follow-exec-mode new|same
4098 show follow-exec-mode
4099 Control whether GDB reuses the same inferior across an exec call or
4100 creates a new one. This is useful to be able to restart the old
4101 executable after the inferior having done an exec call.
4103 set default-collect EXPR, ...
4104 show default-collect
4105 Define a list of expressions to be collected at each tracepoint.
4106 This is a useful way to ensure essential items are not overlooked,
4107 such as registers or a critical global variable.
4109 set disconnected-tracing
4110 show disconnected-tracing
4111 If set to 1, the target is instructed to continue tracing if it
4112 loses its connection to GDB. If 0, the target is to stop tracing
4115 set circular-trace-buffer
4116 show circular-trace-buffer
4117 If set to on, the target is instructed to use a circular trace buffer
4118 and discard the oldest trace frames instead of stopping the trace due
4119 to a full trace buffer. If set to off, the trace stops when the buffer
4120 fills up. Some targets may not support this.
4122 set script-extension off|soft|strict
4123 show script-extension
4124 If set to "off", the debugger does not perform any script language
4125 recognition, and all sourced files are assumed to be GDB scripts.
4126 If set to "soft" (the default), files are sourced according to
4127 filename extension, falling back to GDB scripts if the first
4129 If set to "strict", files are sourced according to filename extension.
4131 set ada trust-PAD-over-XVS on|off
4132 show ada trust-PAD-over-XVS
4133 If off, activate a workaround against a bug in the debugging information
4134 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4135 the GCC sources for more information about the GNAT encoding and
4136 PAD types in particular). It is always safe to set this option to
4137 off, but this introduces a slight performance penalty. The default
4140 * Python API Improvements
4142 ** GDB provides the new class gdb.LazyString. This is useful in
4143 some pretty-printing cases. The new method gdb.Value.lazy_string
4144 provides a simple way to create objects of this type.
4146 ** The fields returned by gdb.Type.fields now have an
4147 `is_base_class' attribute.
4149 ** The new method gdb.Type.range returns the range of an array type.
4151 ** The new method gdb.parse_and_eval can be used to parse and
4152 evaluate an expression.
4154 * New remote packets
4157 Define a trace state variable.
4160 Get the current value of a trace state variable.
4163 Set desired tracing behavior upon disconnection.
4166 Set the trace buffer to be linear or circular.
4169 Get data about the tracepoints currently in use.
4173 Process record now works correctly with hardware watchpoints.
4175 Multiple bug fixes have been made to the mips-irix port, making it
4176 much more reliable. In particular:
4177 - Debugging threaded applications is now possible again. Previously,
4178 GDB would hang while starting the program, or while waiting for
4179 the program to stop at a breakpoint.
4180 - Attaching to a running process no longer hangs.
4181 - An error occurring while loading a core file has been fixed.
4182 - Changing the value of the PC register now works again. This fixes
4183 problems observed when using the "jump" command, or when calling
4184 a function from GDB, or even when assigning a new value to $pc.
4185 - With the "finish" and "return" commands, the return value for functions
4186 returning a small array is now correctly printed.
4187 - It is now possible to break on shared library code which gets executed
4188 during a shared library init phase (code executed while executing
4189 their .init section). Previously, the breakpoint would have no effect.
4190 - GDB is now able to backtrace through the signal handler for
4191 non-threaded programs.
4193 PIE (Position Independent Executable) programs debugging is now supported.
4194 This includes debugging execution of PIC (Position Independent Code) shared
4195 libraries although for that, it should be possible to run such libraries as an
4198 *** Changes in GDB 7.0
4200 * GDB now has an interface for JIT compilation. Applications that
4201 dynamically generate code can create symbol files in memory and register
4202 them with GDB. For users, the feature should work transparently, and
4203 for JIT developers, the interface is documented in the GDB manual in the
4204 "JIT Compilation Interface" chapter.
4206 * Tracepoints may now be conditional. The syntax is as for
4207 breakpoints; either an "if" clause appended to the "trace" command,
4208 or the "condition" command is available. GDB sends the condition to
4209 the target for evaluation using the same bytecode format as is used
4210 for tracepoint actions.
4212 * The disassemble command now supports: an optional /r modifier, print the
4213 raw instructions in hex as well as in symbolic form, and an optional /m
4214 modifier to print mixed source+assembly.
4216 * Process record and replay
4218 In a architecture environment that supports ``process record and
4219 replay'', ``process record and replay'' target can record a log of
4220 the process execution, and replay it with both forward and reverse
4223 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4224 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4225 set execution-direction {forward|reverse}, for targets that support
4228 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4229 feature is available with a native GDB running on kernel version
4232 * GDB now has support for multi-byte and wide character sets on the
4233 target. Strings whose character type is wchar_t, char16_t, or
4234 char32_t are now correctly printed. GDB supports wide- and unicode-
4235 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4236 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4237 `printf'. This feature requires iconv to work properly; if your
4238 system does not have a working iconv, GDB can use GNU libiconv. See
4239 the installation instructions for more information.
4241 * GDB now supports automatic retrieval of shared library files from
4242 remote targets. To use this feature, specify a system root that begins
4243 with the `remote:' prefix, either via the `set sysroot' command or via
4244 the `--with-sysroot' configure-time option.
4246 * "info sharedlibrary" now takes an optional regex of libraries to show,
4247 and it now reports if a shared library has no debugging information.
4249 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4250 now complete on file names.
4252 * When completing in expressions, gdb will attempt to limit
4253 completions to allowable structure or union fields, where appropriate.
4254 For instance, consider:
4256 # struct example { int f1; double f2; };
4257 # struct example variable;
4260 If the user types TAB at the end of this command line, the available
4261 completions will be "f1" and "f2".
4263 * Inlined functions are now supported. They show up in backtraces, and
4264 the "step", "next", and "finish" commands handle them automatically.
4266 * GDB now supports the token-splicing (##) and stringification (#)
4267 operators when expanding macros. It also supports variable-arity
4270 * GDB now supports inspecting extra signal information, exported by
4271 the new $_siginfo convenience variable. The feature is currently
4272 implemented on linux ARM, i386 and amd64.
4274 * GDB can now display the VFP floating point registers and NEON vector
4275 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4276 can provide these registers (requires Linux 2.6.30 or later). Remote
4277 and simulator targets may also provide them.
4279 * New remote packets
4282 Search memory for a sequence of bytes.
4285 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4286 operation over reliable transport links. Use of this packet is
4287 controlled by the `set remote noack-packet' command.
4290 Kill the process with the specified process ID. Use this in preference
4291 to `k' when multiprocess protocol extensions are supported.
4294 Obtains additional operating system information
4298 Read or write additional signal information.
4300 * Removed remote protocol undocumented extension
4302 An undocumented extension to the remote protocol's `S' stop reply
4303 packet that permitted the stub to pass a process id was removed.
4304 Remote servers should use the `T' stop reply packet instead.
4306 * GDB now supports multiple function calling conventions according to the
4307 DWARF-2 DW_AT_calling_convention function attribute.
4309 * The SH target utilizes the aforementioned change to distinguish between gcc
4310 and Renesas calling convention. It also adds the new CLI commands
4311 `set/show sh calling-convention'.
4313 * GDB can now read compressed debug sections, as produced by GNU gold
4314 with the --compress-debug-sections=zlib flag.
4316 * 64-bit core files are now supported on AIX.
4318 * Thread switching is now supported on Tru64.
4320 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4321 which will be allocated using malloc later in program execution.
4323 * The qXfer:libraries:read remote protocol packet now allows passing a
4324 list of section offsets.
4326 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4327 conditions handling signals delivered during attach or thread creation
4328 have also been fixed.
4330 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4331 From the user's standpoint, all unqualified instances of True and False
4332 are treated as the standard definitions, regardless of context.
4334 * GDB now parses C++ symbol and type names more flexibly. For
4337 template<typename T> class C { };
4340 GDB will now correctly handle all of:
4342 ptype C<char const *>
4343 ptype C<char const*>
4344 ptype C<const char *>
4345 ptype C<const char*>
4347 * New features in the GDB remote stub, gdbserver
4349 - The "--wrapper" command-line argument tells gdbserver to use a
4350 wrapper program to launch programs for debugging.
4352 - On PowerPC and S/390 targets, it is now possible to use a single
4353 gdbserver executable to debug both 32-bit and 64-bit programs.
4354 (This requires gdbserver itself to be built as a 64-bit executable.)
4356 - gdbserver uses the new noack protocol mode for TCP connections to
4357 reduce communications latency, if also supported and enabled in GDB.
4359 - Support for the sparc64-linux-gnu target is now included in
4362 - The amd64-linux build of gdbserver now supports debugging both
4363 32-bit and 64-bit programs.
4365 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4366 now support hardware watchpoints, and will use them automatically
4371 GDB now has support for scripting using Python. Whether this is
4372 available is determined at configure time.
4374 New GDB commands can now be written in Python.
4376 * Ada tasking support
4378 Ada tasks can now be inspected in GDB. The following commands have
4382 Print the list of Ada tasks.
4384 Print detailed information about task number N.
4386 Print the task number of the current task.
4388 Switch the context of debugging to task number N.
4390 * Support for user-defined prefixed commands. The "define" command can
4391 add new commands to existing prefixes, e.g. "target".
4393 * Multi-inferior, multi-process debugging.
4395 GDB now has generalized support for multi-inferior debugging. See
4396 "Debugging Multiple Inferiors" in the manual for more information.
4397 Although availability still depends on target support, the command
4398 set is more uniform now. The GNU/Linux specific multi-forks support
4399 has been migrated to this new framework. This implied some user
4400 visible changes; see "New commands" and also "Removed commands"
4403 * Target descriptions can now describe the target OS ABI. See the
4404 "Target Description Format" section in the user manual for more
4407 * Target descriptions can now describe "compatible" architectures
4408 to indicate that the target can execute applications for a different
4409 architecture in addition to those for the main target architecture.
4410 See the "Target Description Format" section in the user manual for
4413 * Multi-architecture debugging.
4415 GDB now includes general supports for debugging applications on
4416 hybrid systems that use more than one single processor architecture
4417 at the same time. Each such hybrid architecture still requires
4418 specific support to be added. The only hybrid architecture supported
4419 in this version of GDB is the Cell Broadband Engine.
4421 * GDB now supports integrated debugging of Cell/B.E. applications that
4422 use both the PPU and SPU architectures. To enable support for hybrid
4423 Cell/B.E. debugging, you need to configure GDB to support both the
4424 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4425 --enable-targets configure option.
4427 * Non-stop mode debugging.
4429 For some targets, GDB now supports an optional mode of operation in
4430 which you can examine stopped threads while other threads continue
4431 to execute freely. This is referred to as non-stop mode, with the
4432 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4433 section in the user manual for more information.
4435 To be able to support remote non-stop debugging, a remote stub needs
4436 to implement the non-stop mode remote protocol extensions, as
4437 described in the "Remote Non-Stop" section of the user manual. The
4438 GDB remote stub, gdbserver, has been adjusted to support these
4439 extensions on linux targets.
4441 * New commands (for set/show, see "New options" below)
4443 catch syscall [NAME(S) | NUMBER(S)]
4444 Catch system calls. Arguments, which should be names of system
4445 calls or their numbers, mean catch only those syscalls. Without
4446 arguments, every syscall will be caught. When the inferior issues
4447 any of the specified syscalls, GDB will stop and announce the system
4448 call, both when it is called and when its call returns. This
4449 feature is currently available with a native GDB running on the
4450 Linux Kernel, under the following architectures: x86, x86_64,
4451 PowerPC and PowerPC64.
4453 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4455 Search memory for a sequence of bytes.
4457 maint set python print-stack
4458 maint show python print-stack
4459 Show a stack trace when an error is encountered in a Python script.
4462 Invoke CODE by passing it to the Python interpreter.
4467 These allow macros to be defined, undefined, and listed
4471 Show operating system information about processes.
4474 List the inferiors currently under GDB's control.
4477 Switch focus to inferior number NUM.
4480 Detach from inferior number NUM.
4483 Kill inferior number NUM.
4487 set spu stop-on-load
4488 show spu stop-on-load
4489 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4491 set spu auto-flush-cache
4492 show spu auto-flush-cache
4493 Control whether to automatically flush the software-managed cache
4494 during Cell/B.E. debugging.
4496 set sh calling-convention
4497 show sh calling-convention
4498 Control the calling convention used when calling SH target functions.
4501 show debug timestamp
4502 Control display of timestamps with GDB debugging output.
4504 set disassemble-next-line
4505 show disassemble-next-line
4506 Control display of disassembled source lines or instructions when
4509 set remote noack-packet
4510 show remote noack-packet
4511 Set/show the use of remote protocol QStartNoAckMode packet. See above
4512 under "New remote packets."
4514 set remote query-attached-packet
4515 show remote query-attached-packet
4516 Control use of remote protocol `qAttached' (query-attached) packet.
4518 set remote read-siginfo-object
4519 show remote read-siginfo-object
4520 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4523 set remote write-siginfo-object
4524 show remote write-siginfo-object
4525 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4528 set remote reverse-continue
4529 show remote reverse-continue
4530 Control use of remote protocol 'bc' (reverse-continue) packet.
4532 set remote reverse-step
4533 show remote reverse-step
4534 Control use of remote protocol 'bs' (reverse-step) packet.
4536 set displaced-stepping
4537 show displaced-stepping
4538 Control displaced stepping mode. Displaced stepping is a way to
4539 single-step over breakpoints without removing them from the debuggee.
4540 Also known as "out-of-line single-stepping".
4543 show debug displaced
4544 Control display of debugging info for displaced stepping.
4546 maint set internal-error
4547 maint show internal-error
4548 Control what GDB does when an internal error is detected.
4550 maint set internal-warning
4551 maint show internal-warning
4552 Control what GDB does when an internal warning is detected.
4557 Use a wrapper program to launch programs for debugging.
4559 set multiple-symbols (all|ask|cancel)
4560 show multiple-symbols
4561 The value of this variable can be changed to adjust the debugger behavior
4562 when an expression or a breakpoint location contains an ambiguous symbol
4563 name (an overloaded function name, for instance).
4565 set breakpoint always-inserted
4566 show breakpoint always-inserted
4567 Keep breakpoints always inserted in the target, as opposed to inserting
4568 them when resuming the target, and removing them when the target stops.
4569 This option can improve debugger performance on slow remote targets.
4571 set arm fallback-mode (arm|thumb|auto)
4572 show arm fallback-mode
4573 set arm force-mode (arm|thumb|auto)
4575 These commands control how ARM GDB determines whether instructions
4576 are ARM or Thumb. The default for both settings is auto, which uses
4577 the current CPSR value for instructions without symbols; previous
4578 versions of GDB behaved as if "set arm fallback-mode arm".
4580 set disable-randomization
4581 show disable-randomization
4582 Standalone programs run with the virtual address space randomization enabled
4583 by default on some platforms. This option keeps the addresses stable across
4584 multiple debugging sessions.
4588 Control whether other threads are stopped or not when some thread hits
4593 Requests that asynchronous execution is enabled in the target, if available.
4594 In this case, it's possible to resume target in the background, and interact
4595 with GDB while the target is running. "show target-async" displays the
4596 current state of asynchronous execution of the target.
4598 set target-wide-charset
4599 show target-wide-charset
4600 The target-wide-charset is the name of the character set that GDB
4601 uses when printing characters whose type is wchar_t.
4603 set tcp auto-retry (on|off)
4605 set tcp connect-timeout
4606 show tcp connect-timeout
4607 These commands allow GDB to retry failed TCP connections to a remote stub
4608 with a specified timeout period; this is useful if the stub is launched
4609 in parallel with GDB but may not be ready to accept connections immediately.
4611 set libthread-db-search-path
4612 show libthread-db-search-path
4613 Control list of directories which GDB will search for appropriate
4616 set schedule-multiple (on|off)
4617 show schedule-multiple
4618 Allow GDB to resume all threads of all processes or only threads of
4619 the current process.
4623 Use more aggressive caching for accesses to the stack. This improves
4624 performance of remote debugging (particularly backtraces) without
4625 affecting correctness.
4627 set interactive-mode (on|off|auto)
4628 show interactive-mode
4629 Control whether GDB runs in interactive mode (on) or not (off).
4630 When in interactive mode, GDB waits for the user to answer all
4631 queries. Otherwise, GDB does not wait and assumes the default
4632 answer. When set to auto (the default), GDB determines which
4633 mode to use based on the stdin settings.
4638 For program forks, this is replaced by the new more generic `info
4639 inferiors' command. To list checkpoints, you can still use the
4640 `info checkpoints' command, which was an alias for the `info forks'
4644 Replaced by the new `inferior' command. To switch between
4645 checkpoints, you can still use the `restart' command, which was an
4646 alias for the `fork' command.
4649 This is removed, since some targets don't have a notion of
4650 processes. To switch between processes, you can still use the
4651 `inferior' command using GDB's own inferior number.
4654 For program forks, this is replaced by the new more generic `kill
4655 inferior' command. To delete a checkpoint, you can still use the
4656 `delete checkpoint' command, which was an alias for the `delete
4660 For program forks, this is replaced by the new more generic `detach
4661 inferior' command. To detach a checkpoint, you can still use the
4662 `detach checkpoint' command, which was an alias for the `detach
4665 * New native configurations
4667 x86/x86_64 Darwin i[34567]86-*-darwin*
4669 x86_64 MinGW x86_64-*-mingw*
4673 Lattice Mico32 lm32-*
4674 x86 DICOS i[34567]86-*-dicos*
4675 x86_64 DICOS x86_64-*-dicos*
4678 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4679 (mingw32ce) debugging.
4685 These commands were actually not implemented on any target.
4687 *** Changes in GDB 6.8
4689 * New native configurations
4691 NetBSD/hppa hppa*-*netbsd*
4692 Xtensa GNU/Linux xtensa*-*-linux*
4696 NetBSD/hppa hppa*-*-netbsd*
4697 Xtensa GNU/Linux xtensa*-*-linux*
4699 * Change in command line behavior -- corefiles vs. process ids.
4701 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4702 attaching to process NUMBER fails, GDB no longer attempts to open a
4703 core file named NUMBER. Attaching to a program using the -c option
4704 is no longer supported. Instead, use the '-p' or '--pid' options.
4706 * GDB can now be built as a native debugger for debugging Windows x86
4707 (mingw32) Portable Executable (PE) programs.
4709 * Pending breakpoints no longer change their number when their address
4712 * GDB now supports breakpoints with multiple locations,
4713 including breakpoints on C++ constructors, inside C++ templates,
4714 and in inlined functions.
4716 * GDB's ability to debug optimized code has been improved. GDB more
4717 accurately identifies function bodies and lexical blocks that occupy
4718 more than one contiguous range of addresses.
4720 * Target descriptions can now describe registers for PowerPC.
4722 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4723 registers on PowerPC targets.
4725 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4726 targets even when the libthread_db library is not available.
4728 * The GDB remote stub, gdbserver, now supports the new file transfer
4729 commands (remote put, remote get, and remote delete).
4731 * The GDB remote stub, gdbserver, now supports run and attach in
4732 extended-remote mode.
4734 * hppa*64*-*-hpux11* target broken
4735 The debugger is unable to start a program and fails with the following
4736 error: "Error trying to get information about dynamic linker".
4737 The gdb-6.7 release is also affected.
4739 * GDB now supports the --enable-targets= configure option to allow
4740 building a single GDB executable that supports multiple remote
4741 target architectures.
4743 * GDB now supports debugging C and C++ programs which use the
4744 Decimal Floating Point extension. In addition, the PowerPC target
4745 now has a set of pseudo-registers to inspect decimal float values
4746 stored in two consecutive float registers.
4748 * The -break-insert MI command can optionally create pending
4751 * Improved support for debugging Ada
4752 Many improvements to the Ada language support have been made. These
4754 - Better support for Ada2005 interface types
4755 - Improved handling of arrays and slices in general
4756 - Better support for Taft-amendment types
4757 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4759 - Improved command completion in Ada
4762 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4767 set print frame-arguments (all|scalars|none)
4768 show print frame-arguments
4769 The value of this variable can be changed to control which argument
4770 values should be printed by the debugger when displaying a frame.
4775 Transfer files to and from a remote target, and delete remote files.
4782 Transfer files to and from a remote target, and delete remote files.
4784 * New remote packets
4791 Open, close, read, write, and delete files on the remote system.
4794 Attach to an existing process on the remote system, in extended-remote
4798 Run a new process on the remote system, in extended-remote mode.
4800 *** Changes in GDB 6.7
4802 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4803 bfd, libiberty and opcodes, as revealed by static analysis donated by
4804 Coverity, Inc. (http://scan.coverity.com).
4806 * When looking up multiply-defined global symbols, GDB will now prefer the
4807 symbol definition in the current shared library if it was built using the
4808 -Bsymbolic linker option.
4810 * When the Text User Interface (TUI) is not configured, GDB will now
4811 recognize the -tui command-line option and print a message that the TUI
4814 * The GDB remote stub, gdbserver, now has lower overhead for high
4815 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4817 * GDB for MIPS targets now autodetects whether a remote target provides
4818 32-bit or 64-bit register values.
4820 * Support for C++ member pointers has been improved.
4822 * GDB now understands XML target descriptions, which specify the
4823 target's overall architecture. GDB can read a description from
4824 a local file or over the remote serial protocol.
4826 * Vectors of single-byte data use a new integer type which is not
4827 automatically displayed as character or string data.
4829 * The /s format now works with the print command. It displays
4830 arrays of single-byte integers and pointers to single-byte integers
4833 * Target descriptions can now describe target-specific registers,
4834 for architectures which have implemented the support (currently
4835 only ARM, M68K, and MIPS).
4837 * GDB and the GDB remote stub, gdbserver, now support the XScale
4840 * The GDB remote stub, gdbserver, has been updated to support
4841 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4842 has been rewritten to use the standard GDB remote protocol.
4844 * GDB can now step into C++ functions which are called through thunks.
4846 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4848 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4849 layout. It also supports a TextSeg= and DataSeg= response when only
4850 segment base addresses (rather than offsets) are available.
4852 * The /i format now outputs any trailing branch delay slot instructions
4853 immediately following the last instruction within the count specified.
4855 * The GDB remote protocol "T" stop reply packet now supports a
4856 "library" response. Combined with the new "qXfer:libraries:read"
4857 packet, this response allows GDB to debug shared libraries on targets
4858 where the operating system manages the list of loaded libraries (e.g.
4859 Windows and SymbianOS).
4861 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4862 (DLLs) on Windows and Windows CE targets.
4864 * GDB now supports a faster verification that a .debug file matches its binary
4865 according to its build-id signature, if the signature is present.
4871 Enable or disable hardware flow control (RTS/CTS) on the serial port
4872 when debugging using remote targets.
4874 set mem inaccessible-by-default
4875 show mem inaccessible-by-default
4876 If the target supplies a memory map, for instance via the remote
4877 protocol's "qXfer:memory-map:read" packet, setting this variable
4878 prevents GDB from accessing memory outside the memory map. This
4879 is useful for targets with memory mapped registers or which react
4880 badly to accesses of unmapped address space.
4882 set breakpoint auto-hw
4883 show breakpoint auto-hw
4884 If the target supplies a memory map, for instance via the remote
4885 protocol's "qXfer:memory-map:read" packet, setting this variable
4886 lets GDB use hardware breakpoints automatically for memory regions
4887 where it can not use software breakpoints. This covers both the
4888 "break" command and internal breakpoints used for other commands
4889 including "next" and "finish".
4892 catch exception unhandled
4893 Stop the program execution when Ada exceptions are raised.
4896 Stop the program execution when an Ada assertion failed.
4900 Set an alternate system root for target files. This is a more
4901 general version of "set solib-absolute-prefix", which is now
4902 an alias to "set sysroot".
4905 Provide extended SPU facility status information. This set of
4906 commands is available only when debugging the Cell/B.E. SPU
4909 * New native configurations
4911 OpenBSD/sh sh*-*openbsd*
4914 unset tdesc filename
4916 Use the specified local file as an XML target description, and do
4917 not query the target for its built-in description.
4921 OpenBSD/sh sh*-*-openbsd*
4922 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4923 Toshiba Media Processor mep-elf
4925 * New remote packets
4928 Ignore the specified signals; pass them directly to the debugged program
4929 without stopping other threads or reporting them to GDB.
4931 qXfer:features:read:
4932 Read an XML target description from the target, which describes its
4937 Read or write contents of an spufs file on the target system. These
4938 packets are available only on the Cell/B.E. SPU architecture.
4940 qXfer:libraries:read:
4941 Report the loaded shared libraries. Combined with new "T" packet
4942 response, this packet allows GDB to debug shared libraries on
4943 targets where the operating system manages the list of loaded
4944 libraries (e.g. Windows and SymbianOS).
4948 Support for these obsolete configurations has been removed.
4956 i[34567]86-*-lynxos*
4957 i[34567]86-*-netware*
4958 i[34567]86-*-sco3.2v5*
4959 i[34567]86-*-sco3.2v4*
4961 i[34567]86-*-sysv4.2*
4964 i[34567]86-*-unixware2*
4965 i[34567]86-*-unixware*
4974 * Other removed features
4981 Various m68k-only ROM monitors.
4988 Various Renesas ROM monitors and debugging interfaces for SH and
4993 Support for a Macraigor serial interface to on-chip debugging.
4994 GDB does not directly support the newer parallel or USB
4999 A debug information format. The predecessor to DWARF 2 and
5000 DWARF 3, which are still supported.
5002 Support for the HP aCC compiler on HP-UX/PA-RISC
5004 SOM-encapsulated symbolic debugging information, automatic
5005 invocation of pxdb, and the aCC custom C++ ABI. This does not
5006 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5007 with aCC can still be debugged on an assembly level.
5009 MIPS ".pdr" sections
5011 A MIPS-specific format used to describe stack frame layout
5012 in debugging information.
5016 GDB could work with an older version of Guile to debug
5017 the interpreter and Scheme programs running in it.
5019 set mips stack-arg-size
5020 set mips saved-gpreg-size
5022 Use "set mips abi" to control parameter passing for MIPS.
5024 *** Changes in GDB 6.6
5029 Cell Broadband Engine SPU spu-elf
5031 * GDB can now be configured as a cross-debugger targeting native Windows
5032 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5033 running on a Windows system over TCP/IP to debug Windows programs.
5035 * The GDB remote stub, gdbserver, has been updated to support Windows and
5036 Cygwin debugging. Both single-threaded and multi-threaded programs are
5039 * The "set trust-readonly-sections" command works again. This command was
5040 broken in GDB 6.3, 6.4, and 6.5.
5042 * The "load" command now supports writing to flash memory, if the remote
5043 stub provides the required support.
5045 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5046 longer requires symbolic debug information (e.g. DWARF-2).
5051 unset substitute-path
5052 show substitute-path
5053 Manage a list of substitution rules that GDB uses to rewrite the name
5054 of the directories where the sources are located. This can be useful
5055 for instance when the sources were moved to a different location
5056 between compilation and debugging.
5060 Print each CLI command as it is executed. Each command is prefixed with
5061 a number of `+' symbols representing the nesting depth.
5062 The source command now has a `-v' option to enable the same feature.
5066 The ARM Demon monitor support (RDP protocol, "target rdp").
5068 Kernel Object Display, an embedded debugging feature which only worked with
5069 an obsolete version of Cisco IOS.
5071 The 'set download-write-size' and 'show download-write-size' commands.
5073 * New remote packets
5076 Tell a stub about GDB client features, and request remote target features.
5077 The first feature implemented is PacketSize, which allows the target to
5078 specify the size of packets it can handle - to minimize the number of
5079 packets required and improve performance when connected to a remote
5083 Fetch an OS auxilliary vector from the remote stub. This packet is a
5084 more efficient replacement for qPart:auxv:read.
5086 qXfer:memory-map:read:
5087 Fetch a memory map from the remote stub, including information about
5088 RAM, ROM, and flash memory devices.
5093 Erase and program a flash memory device.
5095 * Removed remote packets
5098 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5099 used it, and only gdbserver implemented it.
5101 *** Changes in GDB 6.5
5105 Renesas M32C/M16C m32c-elf
5107 Morpho Technologies ms1 ms1-elf
5111 init-if-undefined Initialize a convenience variable, but
5112 only if it doesn't already have a value.
5114 The following commands are presently only implemented for native GNU/Linux:
5116 checkpoint Save a snapshot of the program state.
5118 restart <n> Return the program state to a
5119 previously saved state.
5121 info checkpoints List currently saved checkpoints.
5123 delete-checkpoint <n> Delete a previously saved checkpoint.
5125 set|show detach-on-fork Tell gdb whether to detach from a newly
5126 forked process, or to keep debugging it.
5128 info forks List forks of the user program that
5129 are available to be debugged.
5131 fork <n> Switch to debugging one of several
5132 forks of the user program that are
5133 available to be debugged.
5135 delete-fork <n> Delete a fork from the list of forks
5136 that are available to be debugged (and
5137 kill the forked process).
5139 detach-fork <n> Delete a fork from the list of forks
5140 that are available to be debugged (and
5141 allow the process to continue).
5145 Morpho Technologies ms2 ms1-elf
5147 * Improved Windows host support
5149 GDB now builds as a cross debugger hosted on i686-mingw32, including
5150 native console support, and remote communications using either
5151 network sockets or serial ports.
5153 * Improved Modula-2 language support
5155 GDB can now print most types in the Modula-2 syntax. This includes:
5156 basic types, set types, record types, enumerated types, range types,
5157 pointer types and ARRAY types. Procedure var parameters are correctly
5158 printed and hexadecimal addresses and character constants are also
5159 written in the Modula-2 syntax. Best results can be obtained by using
5160 GNU Modula-2 together with the -gdwarf-2 command line option.
5164 The ARM rdi-share module.
5166 The Netware NLM debug server.
5168 *** Changes in GDB 6.4
5170 * New native configurations
5172 OpenBSD/arm arm*-*-openbsd*
5173 OpenBSD/mips64 mips64-*-openbsd*
5177 Morpho Technologies ms1 ms1-elf
5179 * New command line options
5181 --batch-silent As for --batch, but totally silent.
5182 --return-child-result The debugger will exist with the same value
5183 the child (debugged) program exited with.
5184 --eval-command COMMAND, -ex COMMAND
5185 Execute a single GDB CLI command. This may be
5186 specified multiple times and in conjunction
5187 with the --command (-x) option.
5189 * Deprecated commands removed
5191 The following commands, that were deprecated in 2000, have been
5195 set|show arm disassembly-flavor set|show arm disassembler
5196 othernames set arm disassembler
5197 set|show remotedebug set|show debug remote
5198 set|show archdebug set|show debug arch
5199 set|show eventdebug set|show debug event
5202 * New BSD user-level threads support
5204 It is now possible to debug programs using the user-level threads
5205 library on OpenBSD and FreeBSD. Currently supported (target)
5208 FreeBSD/amd64 x86_64-*-freebsd*
5209 FreeBSD/i386 i386-*-freebsd*
5210 OpenBSD/i386 i386-*-openbsd*
5212 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5213 are not yet supported.
5215 * New support for Matsushita MN10300 w/sim added
5216 (Work in progress). mn10300-elf.
5218 * REMOVED configurations and files
5220 VxWorks and the XDR protocol *-*-vxworks
5221 Motorola MCORE mcore-*-*
5222 National Semiconductor NS32000 ns32k-*-*
5224 * New "set print array-indexes" command
5226 After turning this setting "on", GDB prints the index of each element
5227 when displaying arrays. The default is "off" to preserve the previous
5230 * VAX floating point support
5232 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5234 * User-defined command support
5236 In addition to using $arg0..$arg9 for argument passing, it is now possible
5237 to use $argc to determine now many arguments have been passed. See the
5238 section on user-defined commands in the user manual for more information.
5240 *** Changes in GDB 6.3:
5242 * New command line option
5244 GDB now accepts -l followed by a number to set the timeout for remote
5247 * GDB works with GCC -feliminate-dwarf2-dups
5249 GDB now supports a more compact representation of DWARF-2 debug
5250 information using DW_FORM_ref_addr references. These are produced
5251 by GCC with the option -feliminate-dwarf2-dups and also by some
5252 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5253 to use -feliminate-dwarf2-dups.
5255 * Internationalization
5257 When supported by the host system, GDB will be built with
5258 internationalization (libintl). The task of marking up the sources is
5259 continued, we're looking forward to our first translation.
5263 Initial support for debugging programs compiled with the GNAT
5264 implementation of the Ada programming language has been integrated
5265 into GDB. In this release, support is limited to expression evaluation.
5267 * New native configurations
5269 GNU/Linux/m32r m32r-*-linux-gnu
5273 GDB's remote protocol now includes support for the 'p' packet. This
5274 packet is used to fetch individual registers from a remote inferior.
5276 * END-OF-LIFE registers[] compatibility module
5278 GDB's internal register infrastructure has been completely rewritten.
5279 The new infrastructure making possible the implementation of key new
5280 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5283 GDB 6.3 will be the last release to include the registers[]
5284 compatibility module that allowed out-of-date configurations to
5285 continue to work. This change directly impacts the following
5295 powerpc bdm protocol
5297 Unless there is activity to revive these configurations, they will be
5298 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5300 * OBSOLETE configurations and files
5302 Configurations that have been declared obsolete in this release have
5303 been commented out. Unless there is activity to revive these
5304 configurations, the next release of GDB will have their sources
5305 permanently REMOVED.
5314 *** Changes in GDB 6.2.1:
5316 * MIPS `break main; run' gave an heuristic-fence-post warning
5318 When attempting to run even a simple program, a warning about
5319 heuristic-fence-post being hit would be reported. This problem has
5322 * MIPS IRIX 'long double' crashed GDB
5324 When examining a long double variable, GDB would get a segmentation
5325 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5326 IRIX long double values).
5330 A bug in the VAX stack code was causing problems with the "next"
5331 command. This problem has been fixed.
5333 *** Changes in GDB 6.2:
5335 * Fix for ``many threads''
5337 On GNU/Linux systems that use the NPTL threads library, a program
5338 rapidly creating and deleting threads would confuse GDB leading to the
5341 ptrace: No such process.
5342 thread_db_get_info: cannot get thread info: generic error
5344 This problem has been fixed.
5346 * "-async" and "-noasync" options removed.
5348 Support for the broken "-noasync" option has been removed (it caused
5351 * New ``start'' command.
5353 This command runs the program until the beginning of the main procedure.
5355 * New BSD Kernel Data Access Library (libkvm) interface
5357 Using ``target kvm'' it is now possible to debug kernel core dumps and
5358 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5359 platforms. Currently supported (native-only) configurations are:
5361 FreeBSD/amd64 x86_64-*-freebsd*
5362 FreeBSD/i386 i?86-*-freebsd*
5363 NetBSD/i386 i?86-*-netbsd*
5364 NetBSD/m68k m68*-*-netbsd*
5365 NetBSD/sparc sparc-*-netbsd*
5366 OpenBSD/amd64 x86_64-*-openbsd*
5367 OpenBSD/i386 i?86-*-openbsd*
5368 OpenBSD/m68k m68*-openbsd*
5369 OpenBSD/sparc sparc-*-openbsd*
5371 * Signal trampoline code overhauled
5373 Many generic problems with GDB's signal handling code have been fixed.
5374 These include: backtraces through non-contiguous stacks; recognition
5375 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5376 call; backtrace through a signal trampoline; step into and out of
5377 signal handlers; and single-stepping in the signal trampoline.
5379 Please note that kernel bugs are a limiting factor here. These
5380 features have been shown to work on an s390 GNU/Linux system that
5381 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5383 * Cygwin support for DWARF 2 added.
5385 * New native configurations
5387 GNU/Linux/hppa hppa*-*-linux*
5388 OpenBSD/hppa hppa*-*-openbsd*
5389 OpenBSD/m68k m68*-*-openbsd*
5390 OpenBSD/m88k m88*-*-openbsd*
5391 OpenBSD/powerpc powerpc-*-openbsd*
5392 NetBSD/vax vax-*-netbsd*
5393 OpenBSD/vax vax-*-openbsd*
5395 * END-OF-LIFE frame compatibility module
5397 GDB's internal frame infrastructure has been completely rewritten.
5398 The new infrastructure making it possible to support key new features
5399 including DWARF 2 Call Frame Information. To aid in the task of
5400 migrating old configurations to this new infrastructure, a
5401 compatibility module, that allowed old configurations to continue to
5402 work, was also included.
5404 GDB 6.2 will be the last release to include this frame compatibility
5405 module. This change directly impacts the following configurations:
5415 Unless there is activity to revive these configurations, they will be
5416 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5418 * REMOVED configurations and files
5420 Sun 3, running SunOS 3 m68*-*-sunos3*
5421 Sun 3, running SunOS 4 m68*-*-sunos4*
5422 Sun 2, running SunOS 3 m68000-*-sunos3*
5423 Sun 2, running SunOS 4 m68000-*-sunos4*
5424 Motorola 680x0 running LynxOS m68*-*-lynxos*
5425 AT&T 3b1/Unix pc m68*-att-*
5426 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5427 decstation mips-dec-* mips-little-*
5428 riscos mips-*-riscos* mips-*-sysv*
5429 sonymips mips-sony-*
5430 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5432 *** Changes in GDB 6.1.1:
5434 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5436 The TUI (Text-mode User Interface) is now built as part of a default
5437 GDB configuration. It is enabled by either selecting the TUI with the
5438 command line option "-i=tui" or by running the separate "gdbtui"
5439 program. For more information on the TUI, see the manual "Debugging
5442 * Pending breakpoint support (also included in GDB 6.1)
5444 Support has been added to allow you to specify breakpoints in shared
5445 libraries that have not yet been loaded. If a breakpoint location
5446 cannot be found, and the "breakpoint pending" option is set to auto,
5447 GDB queries you if you wish to make the breakpoint pending on a future
5448 shared-library load. If and when GDB resolves the breakpoint symbol,
5449 the pending breakpoint is removed as one or more regular breakpoints
5452 Pending breakpoints are very useful for GCJ Java debugging.
5454 * Fixed ISO-C build problems
5456 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5457 non ISO-C code that stopped them being built using a more strict ISO-C
5458 compiler (e.g., IBM's C compiler).
5460 * Fixed build problem on IRIX 5
5462 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5463 wasn't able to compile compile on an IRIX 5 system.
5465 * Added execute permission to gdb/gdbserver/configure
5467 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5468 permission. This bug would cause configure to fail on a number of
5469 systems (Solaris, IRIX). Ref: server/519.
5471 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5473 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5474 has been updated to use constant array sizes.
5476 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5478 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5479 its generated DWARF Call Frame Info. This encoding was causing GDB to
5480 panic, that panic has been fixed. Ref: gdb/1628.
5482 * Fixed a problem when examining parameters in shared library code.
5484 When examining parameters in optimized shared library code generated
5485 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5486 not available''. GDB now correctly displays the variable's value.
5488 *** Changes in GDB 6.1:
5490 * Removed --with-mmalloc
5492 Support for the mmalloc memory manager has been removed, as it
5493 conflicted with the internal gdb byte cache.
5495 * Changes in AMD64 configurations
5497 The AMD64 target now includes the %cs and %ss registers. As a result
5498 the AMD64 remote protocol has changed; this affects the floating-point
5499 and SSE registers. If you rely on those registers for your debugging,
5500 you should upgrade gdbserver on the remote side.
5502 * Revised SPARC target
5504 The SPARC target has been completely revised, incorporating the
5505 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5506 support for LynxOS and SunOS 4 has been dropped. Calling functions
5507 from within GDB on operating systems with a non-executable stack
5508 (Solaris, OpenBSD) now works.
5512 GDB has a new C++ demangler which does a better job on the mangled
5513 names generated by current versions of g++. It also runs faster, so
5514 with this and other changes gdb should now start faster on large C++
5517 * DWARF 2 Location Expressions
5519 GDB support for location expressions has been extended to support function
5520 arguments and frame bases. Older versions of GDB could crash when they
5523 * C++ nested types and namespaces
5525 GDB's support for nested types and namespaces in C++ has been
5526 improved, especially if you use the DWARF 2 debugging format. (This
5527 is the default for recent versions of GCC on most platforms.)
5528 Specifically, if you have a class "Inner" defined within a class or
5529 namespace "Outer", then GDB realizes that the class's name is
5530 "Outer::Inner", not simply "Inner". This should greatly reduce the
5531 frequency of complaints about not finding RTTI symbols. In addition,
5532 if you are stopped at inside of a function defined within a namespace,
5533 GDB modifies its name lookup accordingly.
5535 * New native configurations
5537 NetBSD/amd64 x86_64-*-netbsd*
5538 OpenBSD/amd64 x86_64-*-openbsd*
5539 OpenBSD/alpha alpha*-*-openbsd*
5540 OpenBSD/sparc sparc-*-openbsd*
5541 OpenBSD/sparc64 sparc64-*-openbsd*
5543 * New debugging protocols
5545 M32R with SDI protocol m32r-*-elf*
5547 * "set prompt-escape-char" command deleted.
5549 The command "set prompt-escape-char" has been deleted. This command,
5550 and its very obscure effect on GDB's prompt, was never documented,
5551 tested, nor mentioned in the NEWS file.
5553 * OBSOLETE configurations and files
5555 Configurations that have been declared obsolete in this release have
5556 been commented out. Unless there is activity to revive these
5557 configurations, the next release of GDB will have their sources
5558 permanently REMOVED.
5560 Sun 3, running SunOS 3 m68*-*-sunos3*
5561 Sun 3, running SunOS 4 m68*-*-sunos4*
5562 Sun 2, running SunOS 3 m68000-*-sunos3*
5563 Sun 2, running SunOS 4 m68000-*-sunos4*
5564 Motorola 680x0 running LynxOS m68*-*-lynxos*
5565 AT&T 3b1/Unix pc m68*-att-*
5566 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5567 decstation mips-dec-* mips-little-*
5568 riscos mips-*-riscos* mips-*-sysv*
5569 sonymips mips-sony-*
5570 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5572 * REMOVED configurations and files
5574 SGI Irix-4.x mips-sgi-irix4 or iris4
5575 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5576 Z8000 simulator z8k-zilog-none or z8ksim
5577 Matsushita MN10200 w/simulator mn10200-*-*
5578 H8/500 simulator h8500-hitachi-hms or h8500hms
5579 HP/PA running BSD hppa*-*-bsd*
5580 HP/PA running OSF/1 hppa*-*-osf*
5581 HP/PA Pro target hppa*-*-pro*
5582 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5583 386BSD i[3456]86-*-bsd*
5584 Sequent family i[3456]86-sequent-sysv4*
5585 i[3456]86-sequent-sysv*
5586 i[3456]86-sequent-bsd*
5587 SPARC running LynxOS sparc-*-lynxos*
5588 SPARC running SunOS 4 sparc-*-sunos4*
5589 Tsqware Sparclet sparclet-*-*
5590 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5592 *** Changes in GDB 6.0:
5596 Support for debugging the Objective-C programming language has been
5597 integrated into GDB.
5599 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5601 DWARF 2's Call Frame Information makes available compiler generated
5602 information that more exactly describes the program's run-time stack.
5603 By using this information, GDB is able to provide more robust stack
5606 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5607 have been updated to use a new backtrace mechanism which includes
5608 DWARF 2 CFI support.
5612 GDB's remote protocol has been extended to include support for hosted
5613 file I/O (where the remote target uses GDB's file system). See GDB's
5614 remote protocol documentation for details.
5616 * All targets using the new architecture framework.
5618 All of GDB's targets have been updated to use the new internal
5619 architecture framework. The way is now open for future GDB releases
5620 to include cross-architecture native debugging support (i386 on amd64,
5623 * GNU/Linux's Thread Local Storage (TLS)
5625 GDB now includes support for for the GNU/Linux implementation of
5626 per-thread variables.
5628 * GNU/Linux's Native POSIX Thread Library (NPTL)
5630 GDB's thread code has been updated to work with either the new
5631 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5633 * Separate debug info.
5635 GDB, in conjunction with BINUTILS, now supports a mechanism for
5636 automatically loading debug information from a separate file. Instead
5637 of shipping full debug and non-debug versions of system libraries,
5638 system integrators can now instead ship just the stripped libraries
5639 and optional debug files.
5641 * DWARF 2 Location Expressions
5643 DWARF 2 Location Expressions allow the compiler to more completely
5644 describe the location of variables (even in optimized code) to the
5647 GDB now includes preliminary support for location expressions (support
5648 for DW_OP_piece is still missing).
5652 A number of long standing bugs that caused GDB to die while starting a
5653 Java application have been fixed. GDB's Java support is now
5654 considered "useable".
5656 * GNU/Linux support for fork, vfork, and exec.
5658 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5659 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5662 * GDB supports logging output to a file
5664 There are two new commands, "set logging" and "show logging", which can be
5665 used to capture GDB's output to a file.
5667 * The meaning of "detach" has changed for gdbserver
5669 The "detach" command will now resume the application, as documented. To
5670 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5673 * d10v, m68hc11 `regs' command deprecated
5675 The `info registers' command has been updated so that it displays the
5676 registers using a format identical to the old `regs' command.
5680 A new command, "maint set profile on/off", has been added. This command can
5681 be used to enable or disable profiling while running GDB, to profile a
5682 session or a set of commands. In addition there is a new configure switch,
5683 "--enable-profiling", which will cause GDB to be compiled with profiling
5684 data, for more informative profiling results.
5686 * Default MI syntax changed to "mi2".
5688 The default MI (machine interface) syntax, enabled by the command line
5689 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5690 "mi1", can be enabled by specifying the option "-i=mi1".
5692 Support for the original "mi0" syntax (included in GDB 5.0) has been
5695 Fix for gdb/192: removed extraneous space when displaying frame level.
5696 Fix for gdb/672: update changelist is now output in mi list format.
5697 Fix for gdb/702: a -var-assign that updates the value now shows up
5698 in a subsequent -var-update.
5700 * New native configurations.
5702 FreeBSD/amd64 x86_64-*-freebsd*
5704 * Multi-arched targets.
5706 HP/PA HPUX11 hppa*-*-hpux*
5707 Renesas M32R/D w/simulator m32r-*-elf*
5709 * OBSOLETE configurations and files
5711 Configurations that have been declared obsolete in this release have
5712 been commented out. Unless there is activity to revive these
5713 configurations, the next release of GDB will have their sources
5714 permanently REMOVED.
5716 Z8000 simulator z8k-zilog-none or z8ksim
5717 Matsushita MN10200 w/simulator mn10200-*-*
5718 H8/500 simulator h8500-hitachi-hms or h8500hms
5719 HP/PA running BSD hppa*-*-bsd*
5720 HP/PA running OSF/1 hppa*-*-osf*
5721 HP/PA Pro target hppa*-*-pro*
5722 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5723 Sequent family i[3456]86-sequent-sysv4*
5724 i[3456]86-sequent-sysv*
5725 i[3456]86-sequent-bsd*
5726 Tsqware Sparclet sparclet-*-*
5727 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5729 * REMOVED configurations and files
5732 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5733 IBM AIX PS/2 i[3456]86-*-aix
5734 i386 running Mach 3.0 i[3456]86-*-mach3*
5735 i386 running Mach i[3456]86-*-mach*
5736 i386 running OSF/1 i[3456]86-*osf1mk*
5737 HP/Apollo 68k Family m68*-apollo*-sysv*,
5739 m68*-hp-bsd*, m68*-hp-hpux*
5740 Argonaut Risc Chip (ARC) arc-*-*
5741 Mitsubishi D30V d30v-*-*
5742 Fujitsu FR30 fr30-*-elf*
5743 OS/9000 i[34]86-*-os9k
5744 I960 with MON960 i960-*-coff
5746 * MIPS $fp behavior changed
5748 The convenience variable $fp, for the MIPS, now consistently returns
5749 the address of the current frame's base. Previously, depending on the
5750 context, $fp could refer to either $sp or the current frame's base
5751 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5752 The GNU Source-Level Debugger''.
5754 *** Changes in GDB 5.3:
5756 * GNU/Linux shared library multi-threaded performance improved.
5758 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5759 `/proc', in preference to `ptrace' for memory reads. This may result
5760 in an improvement in the start-up time of multi-threaded, shared
5761 library applications when run under GDB. One GDB user writes: ``loads
5762 shared libs like mad''.
5764 * ``gdbserver'' now supports multi-threaded applications on some targets
5766 Support for debugging multi-threaded applications which use
5767 the GNU/Linux LinuxThreads package has been added for
5768 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5769 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5771 * GDB now supports C/C++ preprocessor macros.
5773 GDB now expands preprocessor macro invocations in C/C++ expressions,
5774 and provides various commands for showing macro definitions and how
5777 The new command `macro expand EXPRESSION' expands any macro
5778 invocations in expression, and shows the result.
5780 The new command `show macro MACRO-NAME' shows the definition of the
5781 macro named MACRO-NAME, and where it was defined.
5783 Most compilers don't include information about macros in the debugging
5784 information by default. In GCC 3.1, for example, you need to compile
5785 your program with the options `-gdwarf-2 -g3'. If the macro
5786 information is present in the executable, GDB will read it.
5788 * Multi-arched targets.
5790 DEC Alpha (partial) alpha*-*-*
5791 DEC VAX (partial) vax-*-*
5793 National Semiconductor NS32000 (partial) ns32k-*-*
5794 Motorola 68000 (partial) m68k-*-*
5795 Motorola MCORE mcore-*-*
5799 Fujitsu FRV architecture added by Red Hat frv*-*-*
5802 * New native configurations
5804 Alpha NetBSD alpha*-*-netbsd*
5805 SH NetBSD sh*-*-netbsdelf*
5806 MIPS NetBSD mips*-*-netbsd*
5807 UltraSPARC NetBSD sparc64-*-netbsd*
5809 * OBSOLETE configurations and files
5811 Configurations that have been declared obsolete in this release have
5812 been commented out. Unless there is activity to revive these
5813 configurations, the next release of GDB will have their sources
5814 permanently REMOVED.
5816 Mitsubishi D30V d30v-*-*
5817 OS/9000 i[34]86-*-os9k
5818 IBM AIX PS/2 i[3456]86-*-aix
5819 Fujitsu FR30 fr30-*-elf*
5820 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5821 Argonaut Risc Chip (ARC) arc-*-*
5822 i386 running Mach 3.0 i[3456]86-*-mach3*
5823 i386 running Mach i[3456]86-*-mach*
5824 i386 running OSF/1 i[3456]86-*osf1mk*
5825 HP/Apollo 68k Family m68*-apollo*-sysv*,
5827 m68*-hp-bsd*, m68*-hp-hpux*
5828 I960 with MON960 i960-*-coff
5830 * OBSOLETE languages
5832 CHILL, a Pascal like language used by telecommunications companies.
5834 * REMOVED configurations and files
5836 AMD 29k family via UDI a29k-amd-udi, udi29k
5837 A29K VxWorks a29k-*-vxworks
5838 AMD 29000 embedded, using EBMON a29k-none-none
5839 AMD 29000 embedded with COFF a29k-none-coff
5840 AMD 29000 embedded with a.out a29k-none-aout
5842 testsuite/gdb.hp/gdb.threads-hp/ directory
5844 * New command "set max-user-call-depth <nnn>"
5846 This command allows the user to limit the call depth of user-defined
5847 commands. The default is 1024.
5849 * Changes in FreeBSD/i386 native debugging.
5851 Support for the "generate-core-file" has been added.
5853 * New commands "dump", "append", and "restore".
5855 These commands allow data to be copied from target memory
5856 to a bfd-format or binary file (dump and append), and back
5857 from a file into memory (restore).
5859 * Improved "next/step" support on multi-processor Alpha Tru64.
5861 The previous single-step mechanism could cause unpredictable problems,
5862 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5863 of a software single-step mechanism prevents this.
5865 *** Changes in GDB 5.2.1:
5873 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5874 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5875 Fix, by Joel Brobecker imported from mainline.
5877 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5878 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5879 Fix, by Fred Fish, imported from mainline.
5881 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5882 Surprisingly enough, it works now.
5883 By Michal Ludvig, imported from mainline.
5885 i386 hardware watchpoint support:
5886 avoid misses on second run for some targets.
5887 By Pierre Muller, imported from mainline.
5889 *** Changes in GDB 5.2:
5891 * New command "set trust-readonly-sections on[off]".
5893 This command is a hint that tells gdb that read-only sections
5894 really are read-only (ie. that their contents will not change).
5895 In this mode, gdb will go to the object file rather than the
5896 target to read memory from read-only sections (such as ".text").
5897 This can be a significant performance improvement on some
5898 (notably embedded) targets.
5900 * New command "generate-core-file" (or "gcore").
5902 This new gdb command allows the user to drop a core file of the child
5903 process state at any time. So far it's been implemented only for
5904 GNU/Linux and Solaris, but should be relatively easily ported to other
5905 hosts. Argument is core file name (defaults to core.<pid>).
5907 * New command line option
5909 GDB now accepts --pid or -p followed by a process id.
5911 * Change in command line behavior -- corefiles vs. process ids.
5913 There is a subtle behavior in the way in which GDB handles
5914 command line arguments. The first non-flag argument is always
5915 a program to debug, but the second non-flag argument may either
5916 be a corefile or a process id. Previously, GDB would attempt to
5917 open the second argument as a corefile, and if that failed, would
5918 issue a superfluous error message and then attempt to attach it as
5919 a process. Now, if the second argument begins with a non-digit,
5920 it will be treated as a corefile. If it begins with a digit,
5921 GDB will attempt to attach it as a process, and if no such process
5922 is found, will then attempt to open it as a corefile.
5924 * Changes in ARM configurations.
5926 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5927 configuration is fully multi-arch.
5929 * New native configurations
5931 ARM NetBSD arm*-*-netbsd*
5932 x86 OpenBSD i[3456]86-*-openbsd*
5933 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5934 Sparc64 running FreeBSD sparc64-*-freebsd*
5938 Sanyo XStormy16 xstormy16-elf
5940 * OBSOLETE configurations and files
5942 Configurations that have been declared obsolete in this release have
5943 been commented out. Unless there is activity to revive these
5944 configurations, the next release of GDB will have their sources
5945 permanently REMOVED.
5947 AMD 29k family via UDI a29k-amd-udi, udi29k
5948 A29K VxWorks a29k-*-vxworks
5949 AMD 29000 embedded, using EBMON a29k-none-none
5950 AMD 29000 embedded with COFF a29k-none-coff
5951 AMD 29000 embedded with a.out a29k-none-aout
5953 testsuite/gdb.hp/gdb.threads-hp/ directory
5955 * REMOVED configurations and files
5957 TI TMS320C80 tic80-*-*
5959 PowerPC Solaris powerpcle-*-solaris*
5960 PowerPC Windows NT powerpcle-*-cygwin32
5961 PowerPC Netware powerpc-*-netware*
5962 Harris/CXUX m88k m88*-harris-cxux*
5963 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5964 ns32k-utek-sysv* ns32k-utek-*
5965 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5966 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5967 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5968 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5969 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5971 * Changes to command line processing
5973 The new `--args' feature can be used to specify command-line arguments
5974 for the inferior from gdb's command line.
5976 * Changes to key bindings
5978 There is a new `operate-and-get-next' function bound to `C-o'.
5980 *** Changes in GDB 5.1.1
5982 Fix compile problem on DJGPP.
5984 Fix a problem with floating-point registers on the i386 being
5987 Fix to stop GDB crashing on .debug_str debug info.
5989 Numerous documentation fixes.
5991 Numerous testsuite fixes.
5993 *** Changes in GDB 5.1:
5995 * New native configurations
5997 Alpha FreeBSD alpha*-*-freebsd*
5998 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5999 MIPS GNU/Linux mips*-*-linux*
6000 MIPS SGI Irix 6.x mips*-sgi-irix6*
6001 ia64 AIX ia64-*-aix*
6002 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6006 Motorola 68HC11 and 68HC12 m68hc11-elf
6008 UltraSparc running GNU/Linux sparc64-*-linux*
6010 * OBSOLETE configurations and files
6012 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6013 Harris/CXUX m88k m88*-harris-cxux*
6014 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6015 ns32k-utek-sysv* ns32k-utek-*
6016 TI TMS320C80 tic80-*-*
6018 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6019 PowerPC Solaris powerpcle-*-solaris*
6020 PowerPC Windows NT powerpcle-*-cygwin32
6021 PowerPC Netware powerpc-*-netware*
6022 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6023 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6024 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6025 Apple Macintosh (MPW) host N/A
6027 stuff.c (Program to stuff files into a specially prepared space in kdb)
6028 kdb-start.c (Main loop for the standalone kernel debugger)
6030 Configurations that have been declared obsolete in this release have
6031 been commented out. Unless there is activity to revive these
6032 configurations, the next release of GDB will have their sources
6033 permanently REMOVED.
6035 * REMOVED configurations and files
6037 Altos 3068 m68*-altos-*
6038 Convex c1-*-*, c2-*-*
6040 ARM RISCix arm-*-* (as host)
6044 * GDB has been converted to ISO C.
6046 GDB's source code has been converted to ISO C. In particular, the
6047 sources are fully protoized, and rely on standard headers being
6052 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6054 * The MI enabled by default.
6056 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6057 revised and enabled by default. Packages which use GDB as a debugging
6058 engine behind a UI or another front end are encouraged to switch to
6059 using the GDB/MI interface, instead of the old annotations interface
6060 which is now deprecated.
6062 * Support for debugging Pascal programs.
6064 GDB now includes support for debugging Pascal programs. The following
6065 main features are supported:
6067 - Pascal-specific data types such as sets;
6069 - automatic recognition of Pascal sources based on file-name
6072 - Pascal-style display of data types, variables, and functions;
6074 - a Pascal expression parser.
6076 However, some important features are not yet supported.
6078 - Pascal string operations are not supported at all;
6080 - there are some problems with boolean types;
6082 - Pascal type hexadecimal constants are not supported
6083 because they conflict with the internal variables format;
6085 - support for Pascal objects and classes is not full yet;
6087 - unlike Pascal, GDB is case-sensitive for symbol names.
6089 * Changes in completion.
6091 Commands such as `shell', `run' and `set args', which pass arguments
6092 to inferior programs, now complete on file names, similar to what
6093 users expect at the shell prompt.
6095 Commands which accept locations, such as `disassemble', `print',
6096 `breakpoint', `until', etc. now complete on filenames as well as
6097 program symbols. Thus, if you type "break foob TAB", and the source
6098 files linked into the programs include `foobar.c', that file name will
6099 be one of the candidates for completion. However, file names are not
6100 considered for completion after you typed a colon that delimits a file
6101 name from a name of a function in that file, as in "break foo.c:bar".
6103 `set demangle-style' completes on available demangling styles.
6105 * New platform-independent commands:
6107 It is now possible to define a post-hook for a command as well as a
6108 hook that runs before the command. For more details, see the
6109 documentation of `hookpost' in the GDB manual.
6111 * Changes in GNU/Linux native debugging.
6113 Support for debugging multi-threaded programs has been completely
6114 revised for all platforms except m68k and sparc. You can now debug as
6115 many threads as your system allows you to have.
6117 Attach/detach is supported for multi-threaded programs.
6119 Support for SSE registers was added for x86. This doesn't work for
6120 multi-threaded programs though.
6122 * Changes in MIPS configurations.
6124 Multi-arch support is enabled for all MIPS configurations.
6126 GDB can now be built as native debugger on SGI Irix 6.x systems for
6127 debugging n32 executables. (Debugging 64-bit executables is not yet
6130 * Unified support for hardware watchpoints in all x86 configurations.
6132 Most (if not all) native x86 configurations support hardware-assisted
6133 breakpoints and watchpoints in a unified manner. This support
6134 implements debug register sharing between watchpoints, which allows to
6135 put a virtually infinite number of watchpoints on the same address,
6136 and also supports watching regions up to 16 bytes with several debug
6139 The new maintenance command `maintenance show-debug-regs' toggles
6140 debugging print-outs in functions that insert, remove, and test
6141 watchpoints and hardware breakpoints.
6143 * Changes in the DJGPP native configuration.
6145 New command ``info dos sysinfo'' displays assorted information about
6146 the CPU, OS, memory, and DPMI server.
6148 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6149 display information about segment descriptors stored in GDT, LDT, and
6152 New commands ``info dos pde'' and ``info dos pte'' display entries
6153 from Page Directory and Page Tables (for now works with CWSDPMI only).
6154 New command ``info dos address-pte'' displays the Page Table entry for
6155 a given linear address.
6157 GDB can now pass command lines longer than 126 characters to the
6158 program being debugged (requires an update to the libdbg.a library
6159 which is part of the DJGPP development kit).
6161 DWARF2 debug info is now supported.
6163 It is now possible to `step' and `next' through calls to `longjmp'.
6165 * Changes in documentation.
6167 All GDB documentation was converted to GFDL, the GNU Free
6168 Documentation License.
6170 Tracepoints-related commands are now fully documented in the GDB
6173 TUI, the Text-mode User Interface, is now documented in the manual.
6175 Tracepoints-related commands are now fully documented in the GDB
6178 The "GDB Internals" manual now has an index. It also includes
6179 documentation of `ui_out' functions, GDB coding standards, x86
6180 hardware watchpoints, and memory region attributes.
6182 * GDB's version number moved to ``version.in''
6184 The Makefile variable VERSION has been replaced by the file
6185 ``version.in''. People creating GDB distributions should update the
6186 contents of this file.
6190 GUD support is now a standard part of the EMACS distribution.
6192 *** Changes in GDB 5.0:
6194 * Improved support for debugging FP programs on x86 targets
6196 Unified and much-improved support for debugging floating-point
6197 programs on all x86 targets. In particular, ``info float'' now
6198 displays the FP registers in the same format on all x86 targets, with
6199 greater level of detail.
6201 * Improvements and bugfixes in hardware-assisted watchpoints
6203 It is now possible to watch array elements, struct members, and
6204 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6205 on x86 targets no longer erroneously trigger when the address is
6208 * Improvements in the native DJGPP version of GDB
6210 The distribution now includes all the scripts and auxiliary files
6211 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6212 machines ``out of the box''.
6214 The DJGPP version can now debug programs that use signals. It is
6215 possible to catch signals that happened in the debuggee, deliver
6216 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6217 would kill the program being debugged.) Programs that hook hardware
6218 interrupts (keyboard, timer, etc.) can also be debugged.
6220 It is now possible to debug DJGPP programs that redirect their
6221 standard handles or switch them to raw (as opposed to cooked) mode, or
6222 even close them. The command ``run < foo > bar'' works as expected,
6223 and ``info terminal'' reports useful information about the debuggee's
6224 terminal, including raw/cooked mode, redirection, etc.
6226 The DJGPP version now uses termios functions for console I/O, which
6227 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6230 DOS-style file names with drive letters are now fully supported by
6233 It is now possible to debug DJGPP programs that switch their working
6234 directory. It is also possible to rerun the debuggee any number of
6235 times without restarting GDB; thus, you can use the same setup,
6236 breakpoints, etc. for many debugging sessions.
6238 * New native configurations
6240 ARM GNU/Linux arm*-*-linux*
6241 PowerPC GNU/Linux powerpc-*-linux*
6245 Motorola MCore mcore-*-*
6246 x86 VxWorks i[3456]86-*-vxworks*
6247 PowerPC VxWorks powerpc-*-vxworks*
6248 TI TMS320C80 tic80-*-*
6250 * OBSOLETE configurations
6252 Altos 3068 m68*-altos-*
6253 Convex c1-*-*, c2-*-*
6255 ARM RISCix arm-*-* (as host)
6258 Configurations that have been declared obsolete will be commented out,
6259 but the code will be left in place. If there is no activity to revive
6260 these configurations before the next release of GDB, the sources will
6261 be permanently REMOVED.
6263 * Gould support removed
6265 Support for the Gould PowerNode and NP1 has been removed.
6267 * New features for SVR4
6269 On SVR4 native platforms (such as Solaris), if you attach to a process
6270 without first loading a symbol file, GDB will now attempt to locate and
6271 load symbols from the running process's executable file.
6273 * Many C++ enhancements
6275 C++ support has been greatly improved. Overload resolution now works properly
6276 in almost all cases. RTTI support is on the way.
6278 * Remote targets can connect to a sub-program
6280 A popen(3) style serial-device has been added. This device starts a
6281 sub-process (such as a stand-alone simulator) and then communicates
6282 with that. The sub-program to run is specified using the syntax
6283 ``|<program> <args>'' vis:
6285 (gdb) set remotedebug 1
6286 (gdb) target extended-remote |mn10300-elf-sim program-args
6288 * MIPS 64 remote protocol
6290 A long standing bug in the mips64 remote protocol where by GDB
6291 expected certain 32 bit registers (ex SR) to be transfered as 32
6292 instead of 64 bits has been fixed.
6294 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6295 added to provide backward compatibility with older versions of GDB.
6297 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6299 The command ``set remotebinarydownload'' command has been replaced by
6300 ``set remote X-packet''. Other commands in ``set remote'' family
6301 include ``set remote P-packet''.
6303 * Breakpoint commands accept ranges.
6305 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6306 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6307 ``tracepoint passcount'' also accepts a range of tracepoints.
6309 * ``apropos'' command added.
6311 The ``apropos'' command searches through command names and
6312 documentation strings, printing out matches, making it much easier to
6313 try to find a command that does what you are looking for.
6317 A new machine oriented interface (MI) has been added to GDB. This
6318 interface is designed for debug environments running GDB as a separate
6319 process. This is part of the long term libGDB project. See the
6320 "GDB/MI" chapter of the GDB manual for further information. It can be
6321 enabled by configuring with:
6323 .../configure --enable-gdbmi
6325 *** Changes in GDB-4.18:
6327 * New native configurations
6329 HP-UX 10.20 hppa*-*-hpux10.20
6330 HP-UX 11.x hppa*-*-hpux11.0*
6331 M68K GNU/Linux m68*-*-linux*
6335 Fujitsu FR30 fr30-*-elf*
6336 Intel StrongARM strongarm-*-*
6337 Mitsubishi D30V d30v-*-*
6339 * OBSOLETE configurations
6341 Gould PowerNode, NP1 np1-*-*, pn-*-*
6343 Configurations that have been declared obsolete will be commented out,
6344 but the code will be left in place. If there is no activity to revive
6345 these configurations before the next release of GDB, the sources will
6346 be permanently REMOVED.
6350 As a compatibility experiment, GDB's source files buildsym.h and
6351 buildsym.c have been converted to pure standard C, no longer
6352 containing any K&R compatibility code. We believe that all systems in
6353 use today either come with a standard C compiler, or have a GCC port
6354 available. If this is not true, please report the affected
6355 configuration to bug-gdb@gnu.org immediately. See the README file for
6356 information about getting a standard C compiler if you don't have one
6361 GDB now uses readline 2.2.
6363 * set extension-language
6365 You can now control the mapping between filename extensions and source
6366 languages by using the `set extension-language' command. For instance,
6367 you can ask GDB to treat .c files as C++ by saying
6368 set extension-language .c c++
6369 The command `info extensions' lists all of the recognized extensions
6370 and their associated languages.
6372 * Setting processor type for PowerPC and RS/6000
6374 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6375 you can use the `set processor' command to specify what variant of the
6376 PowerPC family you are debugging. The command
6380 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6381 following PowerPC and RS6000 variants:
6383 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6384 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6386 403GC IBM PowerPC 403GC
6387 505 Motorola PowerPC 505
6388 860 Motorola PowerPC 860 or 850
6389 601 Motorola PowerPC 601
6390 602 Motorola PowerPC 602
6391 603 Motorola/IBM PowerPC 603 or 603e
6392 604 Motorola PowerPC 604 or 604e
6393 750 Motorola/IBM PowerPC 750 or 750
6395 At the moment, this command just tells GDB what to name the
6396 special-purpose processor registers. Since almost all the affected
6397 registers are inaccessible to user-level programs, this command is
6398 only useful for remote debugging in its present form.
6402 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6403 more extensive support for HP-UX. Added features include shared
6404 library support, kernel threads and hardware watchpoints for 11.00,
6405 support for HP's ANSI C and C++ compilers, and a compatibility mode
6406 for xdb and dbx commands.
6410 HP's donation includes the new concept of catchpoints, which is a
6411 generalization of the old catch command. On HP-UX, it is now possible
6412 to catch exec, fork, and vfork, as well as library loading.
6414 This means that the existing catch command has changed; its first
6415 argument now specifies the type of catch to be set up. See the
6416 output of "help catch" for a list of catchpoint types.
6418 * Debugging across forks
6420 On HP-UX, you can choose which process to debug when a fork() happens
6425 HP has donated a curses-based terminal user interface (TUI). To get
6426 it, build with --enable-tui. Although this can be enabled for any
6427 configuration, at present it only works for native HP debugging.
6429 * GDB remote protocol additions
6431 A new protocol packet 'X' that writes binary data is now available.
6432 Default behavior is to try 'X', then drop back to 'M' if the stub
6433 fails to respond. The settable variable `remotebinarydownload'
6434 allows explicit control over the use of 'X'.
6436 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6437 full 64-bit address. The command
6439 set remoteaddresssize 32
6441 can be used to revert to the old behaviour. For existing remote stubs
6442 the change should not be noticed, as the additional address information
6445 In order to assist in debugging stubs, you may use the maintenance
6446 command `packet' to send any text string to the stub. For instance,
6448 maint packet heythere
6450 sends the packet "$heythere#<checksum>". Note that it is very easy to
6451 disrupt a debugging session by sending the wrong packet at the wrong
6454 The compare-sections command allows you to compare section data on the
6455 target to what is in the executable file without uploading or
6456 downloading, by comparing CRC checksums.
6458 * Tracing can collect general expressions
6460 You may now collect general expressions at tracepoints. This requires
6461 further additions to the target-side stub; see tracepoint.c and
6462 doc/agentexpr.texi for further details.
6464 * mask-address variable for Mips
6466 For Mips targets, you may control the zeroing of the upper 32 bits of
6467 a 64-bit address by entering `set mask-address on'. This is mainly
6468 of interest to users of embedded R4xxx and R5xxx processors.
6470 * Higher serial baud rates
6472 GDB's serial code now allows you to specify baud rates 57600, 115200,
6473 230400, and 460800 baud. (Note that your host system may not be able
6474 to achieve all of these rates.)
6478 The i960 configuration now includes an initial implementation of a
6479 builtin simulator, contributed by Jim Wilson.
6482 *** Changes in GDB-4.17:
6484 * New native configurations
6486 Alpha GNU/Linux alpha*-*-linux*
6487 Unixware 2.x i[3456]86-unixware2*
6488 Irix 6.x mips*-sgi-irix6*
6489 PowerPC GNU/Linux powerpc-*-linux*
6490 PowerPC Solaris powerpcle-*-solaris*
6491 Sparc GNU/Linux sparc-*-linux*
6492 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6496 Argonaut Risc Chip (ARC) arc-*-*
6497 Hitachi H8/300S h8300*-*-*
6498 Matsushita MN10200 w/simulator mn10200-*-*
6499 Matsushita MN10300 w/simulator mn10300-*-*
6500 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6501 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6502 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6503 Mitsubishi D10V w/simulator d10v-*-*
6504 Mitsubishi M32R/D w/simulator m32r-*-elf*
6505 Tsqware Sparclet sparclet-*-*
6506 NEC V850 w/simulator v850-*-*
6508 * New debugging protocols
6510 ARM with RDI protocol arm*-*-*
6511 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6512 DDB and LSI variants of PMON protocol mips*-*-*
6513 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6514 PowerPC with SDS protocol powerpc{,le}-*-eabi
6515 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6519 All configurations can now understand and use the DWARF 2 debugging
6520 format. The choice is automatic, if the symbol file contains DWARF 2
6525 GDB now includes basic Java language support. This support is
6526 only useful with Java compilers that produce native machine code.
6528 * solib-absolute-prefix and solib-search-path
6530 For SunOS and SVR4 shared libraries, you may now set the prefix for
6531 loading absolute shared library symbol files, and the search path for
6532 locating non-absolute shared library symbol files.
6534 * Live range splitting
6536 GDB can now effectively debug code for which GCC has performed live
6537 range splitting as part of its optimization. See gdb/doc/LRS for
6538 more details on the expected format of the stabs information.
6542 GDB's support for the GNU Hurd, including thread debugging, has been
6543 updated to work with current versions of the Hurd.
6547 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6548 instruction set. ARM GDB automatically detects when Thumb
6549 instructions are in use, and adjusts disassembly and backtracing
6554 GDB's MIPS target configurations now handle the MIP16 16-bit
6559 GDB now includes support for overlays; if an executable has been
6560 linked such that multiple sections are based at the same address, GDB
6561 will decide which section to use for symbolic info. You can choose to
6562 control the decision manually, using overlay commands, or implement
6563 additional target-side support and use "overlay load-target" to bring
6564 in the overlay mapping. Do "help overlay" for more detail.
6568 The command "info symbol <address>" displays information about
6569 the symbol at the specified address.
6573 The standard remote protocol now includes an extension that allows
6574 asynchronous collection and display of trace data. This requires
6575 extensive support in the target-side debugging stub. Tracing mode
6576 includes a new interaction mode in GDB and new commands: see the
6577 file tracepoint.c for more details.
6581 Configurations for embedded MIPS now include a simulator contributed
6582 by Cygnus Solutions. The simulator supports the instruction sets
6583 of most MIPS variants.
6587 Sparc configurations may now include the ERC32 simulator contributed
6588 by the European Space Agency. The simulator is not built into
6589 Sparc targets by default; configure with --enable-sim to include it.
6593 For target configurations that may include multiple variants of a
6594 basic architecture (such as MIPS and SH), you may now set the
6595 architecture explicitly. "set arch" sets, "info arch" lists
6596 the possible architectures.
6598 *** Changes in GDB-4.16:
6600 * New native configurations
6602 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6603 M68K NetBSD m68k-*-netbsd*
6604 PowerPC AIX 4.x powerpc-*-aix*
6605 PowerPC MacOS powerpc-*-macos*
6606 PowerPC Windows NT powerpcle-*-cygwin32
6607 RS/6000 AIX 4.x rs6000-*-aix4*
6611 ARM with RDP protocol arm-*-*
6612 I960 with MON960 i960-*-coff
6613 MIPS VxWorks mips*-*-vxworks*
6614 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6615 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6617 Matra Sparclet sparclet-*-*
6621 The powerpc-eabi configuration now includes the PSIM simulator,
6622 contributed by Andrew Cagney, with assistance from Mike Meissner.
6623 PSIM is a very elaborate model of the PowerPC, including not only
6624 basic instruction set execution, but also details of execution unit
6625 performance and I/O hardware. See sim/ppc/README for more details.
6629 GDB now works with Solaris 2.5.
6631 * Windows 95/NT native
6633 GDB will now work as a native debugger on Windows 95 and Windows NT.
6634 To build it from source, you must use the "gnu-win32" environment,
6635 which uses a DLL to emulate enough of Unix to run the GNU tools.
6636 Further information, binaries, and sources are available at
6637 ftp.cygnus.com, under pub/gnu-win32.
6639 * dont-repeat command
6641 If a user-defined command includes the command `dont-repeat', then the
6642 command will not be repeated if the user just types return. This is
6643 useful if the command is time-consuming to run, so that accidental
6644 extra keystrokes don't run the same command many times.
6646 * Send break instead of ^C
6648 The standard remote protocol now includes an option to send a break
6649 rather than a ^C to the target in order to interrupt it. By default,
6650 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6652 * Remote protocol timeout
6654 The standard remote protocol includes a new variable `remotetimeout'
6655 that allows you to set the number of seconds before GDB gives up trying
6656 to read from the target. The default value is 2.
6658 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6660 By default GDB will automatically keep track of objects as they are
6661 loaded and unloaded by the dynamic linker. By using the command `set
6662 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6663 when shared library events occur, thus allowing you to set breakpoints
6664 in shared libraries which are explicitly loaded by the inferior.
6666 Note this feature does not work on hpux8. On hpux9 you must link
6667 /usr/lib/end.o into your program. This feature should work
6668 automatically on hpux10.
6670 * Irix 5.x hardware watchpoint support
6672 Irix 5 configurations now support the use of hardware watchpoints.
6674 * Mips protocol "SYN garbage limit"
6676 When debugging a Mips target using the `target mips' protocol, you
6677 may set the number of characters that GDB will ignore by setting
6678 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6679 every character. The default value is 1050.
6681 * Recording and replaying remote debug sessions
6683 If you set `remotelogfile' to the name of a file, gdb will write to it
6684 a recording of a remote debug session. This recording may then be
6685 replayed back to gdb using "gdbreplay". See gdbserver/README for
6686 details. This is useful when you have a problem with GDB while doing
6687 remote debugging; you can make a recording of the session and send it
6688 to someone else, who can then recreate the problem.
6690 * Speedups for remote debugging
6692 GDB includes speedups for downloading and stepping MIPS systems using
6693 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6694 and more efficient S-record downloading.
6696 * Memory use reductions and statistics collection
6698 GDB now uses less memory and reports statistics about memory usage.
6699 Try the `maint print statistics' command, for example.
6701 *** Changes in GDB-4.15:
6703 * Psymtabs for XCOFF
6705 The symbol reader for AIX GDB now uses partial symbol tables. This
6706 can greatly improve startup time, especially for large executables.
6708 * Remote targets use caching
6710 Remote targets now use a data cache to speed up communication with the
6711 remote side. The data cache could lead to incorrect results because
6712 it doesn't know about volatile variables, thus making it impossible to
6713 debug targets which use memory mapped I/O devices. `set remotecache
6714 off' turns the data cache off.
6716 * Remote targets may have threads
6718 The standard remote protocol now includes support for multiple threads
6719 in the target system, using new protocol commands 'H' and 'T'. See
6720 gdb/remote.c for details.
6724 If GDB is configured with `--enable-netrom', then it will include
6725 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6726 acts as though it is a bank of ROM on the target board, but you can
6727 write into it over the network. GDB's support consists only of
6728 support for fast loading into the emulated ROM; to debug, you must use
6729 another protocol, such as standard remote protocol. The usual
6730 sequence is something like
6732 target nrom <netrom-hostname>
6734 target remote <netrom-hostname>:1235
6738 GDB now includes support for the Apple Macintosh, as a host only. It
6739 may be run as either an MPW tool or as a standalone application, and
6740 it can debug through the serial port. All the usual GDB commands are
6741 available, but to the target command, you must supply "serial" as the
6742 device type instead of "/dev/ttyXX". See mpw-README in the main
6743 directory for more information on how to build. The MPW configuration
6744 scripts */mpw-config.in support only a few targets, and only the
6745 mips-idt-ecoff target has been tested.
6749 GDB configuration now uses autoconf. This is not user-visible,
6750 but does simplify configuration and building.
6754 GDB now supports hpux10.
6756 *** Changes in GDB-4.14:
6758 * New native configurations
6760 x86 FreeBSD i[345]86-*-freebsd
6761 x86 NetBSD i[345]86-*-netbsd
6762 NS32k NetBSD ns32k-*-netbsd
6763 Sparc NetBSD sparc-*-netbsd
6767 A29K VxWorks a29k-*-vxworks
6768 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6769 CPU32 EST-300 emulator m68*-*-est*
6770 PowerPC ELF powerpc-*-elf
6773 * Alpha OSF/1 support for procfs
6775 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6776 possible to attach to running processes. As the mounting of the /proc
6777 filesystem is optional on the Alpha, GDB automatically determines
6778 the availability of /proc during startup. This can lead to problems
6779 if /proc is unmounted after GDB has been started.
6781 * Arguments to user-defined commands
6783 User commands may accept up to 10 arguments separated by whitespace.
6784 Arguments are accessed within the user command via $arg0..$arg9. A
6787 print $arg0 + $arg1 + $arg2
6789 To execute the command use:
6792 Defines the command "adder" which prints the sum of its three arguments.
6793 Note the arguments are text substitutions, so they may reference variables,
6794 use complex expressions, or even perform inferior function calls.
6796 * New `if' and `while' commands
6798 This makes it possible to write more sophisticated user-defined
6799 commands. Both commands take a single argument, which is the
6800 expression to evaluate, and must be followed by the commands to
6801 execute, one per line, if the expression is nonzero, the list being
6802 terminated by the word `end'. The `if' command list may include an
6803 `else' word, which causes the following commands to be executed only
6804 if the expression is zero.
6806 * Fortran source language mode
6808 GDB now includes partial support for Fortran 77. It will recognize
6809 Fortran programs and can evaluate a subset of Fortran expressions, but
6810 variables and functions may not be handled correctly. GDB will work
6811 with G77, but does not yet know much about symbols emitted by other
6814 * Better HPUX support
6816 Most debugging facilities now work on dynamic executables for HPPAs
6817 running hpux9 or later. You can attach to running dynamically linked
6818 processes, but by default the dynamic libraries will be read-only, so
6819 for instance you won't be able to put breakpoints in them. To change
6820 that behavior do the following before running the program:
6826 This will cause the libraries to be mapped private and read-write.
6827 To revert to the normal behavior, do this:
6833 You cannot set breakpoints or examine data in the library until after
6834 the library is loaded if the function/data symbols do not have
6837 GDB can now also read debug symbols produced by the HP C compiler on
6838 HPPAs (sorry, no C++, Fortran or 68k support).
6840 * Target byte order now dynamically selectable
6842 You can choose which byte order to use with a target system, via the
6843 commands "set endian big" and "set endian little", and you can see the
6844 current setting by using "show endian". You can also give the command
6845 "set endian auto", in which case GDB will use the byte order
6846 associated with the executable. Currently, only embedded MIPS
6847 configurations support dynamic selection of target byte order.
6849 * New DOS host serial code
6851 This version uses DPMI interrupts to handle buffered I/O, so you
6852 no longer need to run asynctsr when debugging boards connected to
6855 *** Changes in GDB-4.13:
6857 * New "complete" command
6859 This lists all the possible completions for the rest of the line, if it
6860 were to be given as a command itself. This is intended for use by emacs.
6862 * Trailing space optional in prompt
6864 "set prompt" no longer adds a space for you after the prompt you set. This
6865 allows you to set a prompt which ends in a space or one that does not.
6867 * Breakpoint hit counts
6869 "info break" now displays a count of the number of times the breakpoint
6870 has been hit. This is especially useful in conjunction with "ignore"; you
6871 can ignore a large number of breakpoint hits, look at the breakpoint info
6872 to see how many times the breakpoint was hit, then run again, ignoring one
6873 less than that number, and this will get you quickly to the last hit of
6876 * Ability to stop printing at NULL character
6878 "set print null-stop" will cause GDB to stop printing the characters of
6879 an array when the first NULL is encountered. This is useful when large
6880 arrays actually contain only short strings.
6882 * Shared library breakpoints
6884 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6885 breakpoints in shared libraries before the executable is run.
6887 * Hardware watchpoints
6889 There is a new hardware breakpoint for the watch command for sparclite
6890 targets. See gdb/sparclite/hw_breakpoint.note.
6892 Hardware watchpoints are also now supported under GNU/Linux.
6896 Annotations have been added. These are for use with graphical interfaces,
6897 and are still experimental. Currently only gdba.el uses these.
6899 * Improved Irix 5 support
6901 GDB now works properly with Irix 5.2.
6903 * Improved HPPA support
6905 GDB now works properly with the latest GCC and GAS.
6907 * New native configurations
6909 Sequent PTX4 i[34]86-sequent-ptx4
6910 HPPA running OSF/1 hppa*-*-osf*
6911 Atari TT running SVR4 m68*-*-sysv4*
6912 RS/6000 LynxOS rs6000-*-lynxos*
6916 OS/9000 i[34]86-*-os9k
6917 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6920 * Hitachi SH7000 and E7000-PC ICE support
6922 There is now support for communicating with the Hitachi E7000-PC ICE.
6923 This is available automatically when GDB is configured for the SH.
6927 As usual, a variety of small fixes and improvements, both generic
6928 and configuration-specific. See the ChangeLog for more detail.
6930 *** Changes in GDB-4.12:
6932 * Irix 5 is now supported
6936 GDB-4.12 on the HPPA has a number of changes which make it unable
6937 to debug the output from the currently released versions of GCC and
6938 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6939 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6940 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6943 *** Changes in GDB-4.11:
6945 * User visible changes:
6949 The "set remotedebug" option is now consistent between the mips remote
6950 target, remote targets using the gdb-specific protocol, UDI (AMD's
6951 debug protocol for the 29k) and the 88k bug monitor. It is now an
6952 integer specifying a debug level (normally 0 or 1, but 2 means more
6953 debugging info for the mips target).
6955 * DEC Alpha native support
6957 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6958 debug info, but GDB works fairly well with the DEC compiler and should
6959 work with a future GCC release. See the README file for a few
6960 Alpha-specific notes.
6962 * Preliminary thread implementation
6964 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6966 * LynxOS native and target support for 386
6968 This release has been hosted on LynxOS 2.2, and also can be configured
6969 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6972 * Improvements in C++ mangling/demangling.
6974 This release has much better g++ debugging, specifically in name
6975 mangling/demangling, virtual function calls, print virtual table,
6976 call methods, ...etc.
6978 *** Changes in GDB-4.10:
6980 * User visible changes:
6982 Remote debugging using the GDB-specific (`target remote') protocol now
6983 supports the `load' command. This is only useful if you have some
6984 other way of getting the stub to the target system, and you can put it
6985 somewhere in memory where it won't get clobbered by the download.
6987 Filename completion now works.
6989 When run under emacs mode, the "info line" command now causes the
6990 arrow to point to the line specified. Also, "info line" prints
6991 addresses in symbolic form (as well as hex).
6993 All vxworks based targets now support a user settable option, called
6994 vxworks-timeout. This option represents the number of seconds gdb
6995 should wait for responses to rpc's. You might want to use this if
6996 your vxworks target is, perhaps, a slow software simulator or happens
6997 to be on the far side of a thin network line.
7001 This release contains support for using a DEC alpha as a GDB host for
7002 cross debugging. Native alpha debugging is not supported yet.
7005 *** Changes in GDB-4.9:
7009 This is the first GDB release which is accompanied by a matching testsuite.
7010 The testsuite requires installation of dejagnu, which should be available
7011 via ftp from most sites that carry GNU software.
7015 'Cfront' style demangling has had its name changed to 'ARM' style, to
7016 emphasize that it was written from the specifications in the C++ Annotated
7017 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7018 disclaimers, it still generated too much confusion with users attempting to
7019 use gdb with AT&T cfront.
7023 GDB now uses a standard remote interface to a simulator library.
7024 So far, the library contains simulators for the Zilog Z8001/2, the
7025 Hitachi H8/300, H8/500 and Super-H.
7027 * New targets supported
7029 H8/300 simulator h8300-hitachi-hms or h8300hms
7030 H8/500 simulator h8500-hitachi-hms or h8500hms
7031 SH simulator sh-hitachi-hms or sh
7032 Z8000 simulator z8k-zilog-none or z8ksim
7033 IDT MIPS board over serial line mips-idt-ecoff
7035 Cross-debugging to GO32 targets is supported. It requires a custom
7036 version of the i386-stub.c module which is integrated with the
7037 GO32 memory extender.
7039 * New remote protocols
7041 MIPS remote debugging protocol.
7043 * New source languages supported
7045 This version includes preliminary support for Chill, a Pascal like language
7046 used by telecommunications companies. Chill support is also being integrated
7047 into the GNU compiler, but we don't know when it will be publically available.
7050 *** Changes in GDB-4.8:
7052 * HP Precision Architecture supported
7054 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7055 version of this support was available as a set of patches from the
7056 University of Utah. GDB does not support debugging of programs
7057 compiled with the HP compiler, because HP will not document their file
7058 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7059 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7061 Many problems in the preliminary version have been fixed.
7063 * Faster and better demangling
7065 We have improved template demangling and fixed numerous bugs in the GNU style
7066 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7067 character types (wchar_t) are now supported. Demangling of each symbol is now
7068 only done once, and is cached when the symbol table for a file is read in.
7069 This results in a small increase in memory usage for C programs, a moderate
7070 increase in memory usage for C++ programs, and a fantastic speedup in
7073 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7074 from the specifications in the Annotated Reference Manual, which AT&T's
7075 compiler does not actually implement.
7077 * G++ multiple inheritance compiler problem
7079 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7080 inheritance lattices was reworked to properly discover ambiguities. We
7081 recently found an example which causes this new algorithm to fail in a
7082 very subtle way, producing bad debug information for those classes.
7083 The file 'gcc.patch' (in this directory) can be applied to gcc to
7084 circumvent the problem. A future GCC release will contain a complete
7087 The previous G++ debug info problem (mentioned below for the gdb-4.7
7088 release) is fixed in gcc version 2.3.2.
7090 * Improved configure script
7092 The `configure' script will now attempt to guess your system type if
7093 you don't supply a host system type. The old scheme of supplying a
7094 host system triplet is preferable over using this. All the magic is
7095 done in the new `config.guess' script. Examine it for details.
7097 We have also brought our configure script much more in line with the FSF's
7098 version. It now supports the --with-xxx options. In particular,
7099 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7100 The resulting GDB will not be able to read arbitrary object file formats --
7101 only the format ``expected'' to be used on the configured target system.
7102 We hope to make this the default in a future release.
7104 * Documentation improvements
7106 There's new internal documentation on how to modify GDB, and how to
7107 produce clean changes to the code. We implore people to read it
7108 before submitting changes.
7110 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7111 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7112 `info' files are also provided. To build `info' files from scratch,
7113 you will need the latest `makeinfo' release, which will be available in
7114 a future texinfo-X.Y release.
7116 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7117 We're not sure exactly which versions have this problem, but it has
7118 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7119 or better. If that isn't possible, there is a patch in
7120 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7121 around this problem.
7125 GDB now supports array constants that can be used in expressions typed in by
7126 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7127 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7130 The new directory `gdb/sparclite' contains a program that demonstrates
7131 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7133 * New native hosts supported
7135 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7136 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7138 * New targets supported
7140 AMD 29k family via UDI a29k-amd-udi or udi29k
7142 * New file formats supported
7144 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7145 HPUX core files, and SCO 3.2v2 core files.
7149 Attaching to processes now works again; thanks for the many bug reports.
7151 We have also stomped on a bunch of core dumps caused by
7152 printf_filtered("%s") problems.
7154 We eliminated a copyright problem on the rpc and ptrace header files
7155 for VxWorks, which was discovered at the last minute during the 4.7
7156 release. You should now be able to build a VxWorks GDB.
7158 You can now interrupt gdb while an attached process is running. This
7159 will cause the attached process to stop, and give control back to GDB.
7161 We fixed problems caused by using too many file descriptors
7162 for reading symbols from object files and libraries. This was
7163 especially a problem for programs that used many (~100) shared
7166 The `step' command now only enters a subroutine if there is line number
7167 information for the subroutine. Otherwise it acts like the `next'
7168 command. Previously, `step' would enter subroutines if there was
7169 any debugging information about the routine. This avoids problems
7170 when using `cc -g1' on MIPS machines.
7172 * Internal improvements
7174 GDB's internal interfaces have been improved to make it easier to support
7175 debugging of multiple languages in the future.
7177 GDB now uses a common structure for symbol information internally.
7178 Minimal symbols (derived from linkage symbols in object files), partial
7179 symbols (from a quick scan of debug information), and full symbols
7180 contain a common subset of information, making it easier to write
7181 shared code that handles any of them.
7183 * New command line options
7185 We now accept --silent as an alias for --quiet.
7189 The memory-mapped-malloc library is now licensed under the GNU Library
7190 General Public License.
7192 *** Changes in GDB-4.7:
7194 * Host/native/target split
7196 GDB has had some major internal surgery to untangle the support for
7197 hosts and remote targets. Now, when you configure GDB for a remote
7198 target, it will no longer load in all of the support for debugging
7199 local programs on the host. When fully completed and tested, this will
7200 ensure that arbitrary host/target combinations are possible.
7202 The primary conceptual shift is to separate the non-portable code in
7203 GDB into three categories. Host specific code is required any time GDB
7204 is compiled on that host, regardless of the target. Target specific
7205 code relates to the peculiarities of the target, but can be compiled on
7206 any host. Native specific code is everything else: it can only be
7207 built when the host and target are the same system. Child process
7208 handling and core file support are two common `native' examples.
7210 GDB's use of /proc for controlling Unix child processes is now cleaner.
7211 It has been split out into a single module under the `target_ops' vector,
7212 plus two native-dependent functions for each system that uses /proc.
7214 * New hosts supported
7216 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7217 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7218 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7220 * New targets supported
7222 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7223 68030 and CPU32 m68030-*-*, m68332-*-*
7225 * New native hosts supported
7227 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7228 (386bsd is not well tested yet)
7229 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7231 * New file formats supported
7233 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7234 supports reading of `a.out.adobe' object files, which are an a.out
7235 format extended with minimal information about multiple sections.
7239 `show copying' is the same as the old `info copying'.
7240 `show warranty' is the same as `info warrantee'.
7241 These were renamed for consistency. The old commands continue to work.
7243 `info handle' is a new alias for `info signals'.
7245 You can now define pre-command hooks, which attach arbitrary command
7246 scripts to any command. The commands in the hook will be executed
7247 prior to the user's command. You can also create a hook which will be
7248 executed whenever the program stops. See gdb.texinfo.
7252 We now deal with Cfront style name mangling, and can even extract type
7253 info from mangled symbols. GDB can automatically figure out which
7254 symbol mangling style your C++ compiler uses.
7256 Calling of methods and virtual functions has been improved as well.
7260 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7261 fixed. This was due to mishandling of the extra N_SO stabs output
7264 We also finally got Ultrix 4.2 running in house, and fixed core file
7265 support, with help from a dozen people on the net.
7267 John M. Farrell discovered that the reason that single-stepping was so
7268 slow on all of the Mips based platforms (primarily SGI and DEC) was
7269 that we were trying to demangle and lookup a symbol used for internal
7270 purposes on every instruction that was being stepped through. Changing
7271 the name of that symbol so that it couldn't be mistaken for a C++
7272 mangled symbol sped things up a great deal.
7274 Rich Pixley sped up symbol lookups in general by getting much smarter
7275 about when C++ symbol mangling is necessary. This should make symbol
7276 completion (TAB on the command line) much faster. It's not as fast as
7277 we'd like, but it's significantly faster than gdb-4.6.
7281 A new user controllable variable 'call_scratch_address' can
7282 specify the location of a scratch area to be used when GDB
7283 calls a function in the target. This is necessary because the
7284 usual method of putting the scratch area on the stack does not work
7285 in systems that have separate instruction and data spaces.
7287 We integrated changes to support the 29k UDI (Universal Debugger
7288 Interface), but discovered at the last minute that we didn't have all
7289 of the appropriate copyright paperwork. We are working with AMD to
7290 resolve this, and hope to have it available soon.
7294 We have sped up the remote serial line protocol, especially for targets
7295 with lots of registers. It now supports a new `expedited status' ('T')
7296 message which can be used in place of the existing 'S' status message.
7297 This allows the remote stub to send only the registers that GDB
7298 needs to make a quick decision about single-stepping or conditional
7299 breakpoints, eliminating the need to fetch the entire register set for
7300 each instruction being stepped through.
7302 The GDB remote serial protocol now implements a write-through cache for
7303 registers, only re-reading the registers if the target has run.
7305 There is also a new remote serial stub for SPARC processors. You can
7306 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7307 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7308 processor with a serial port.
7312 Configure.in files have become much easier to read and modify. A new
7313 `table driven' format makes it more obvious what configurations are
7314 supported, and what files each one uses.
7318 There is a new opcodes library which will eventually contain all of the
7319 disassembly routines and opcode tables. At present, it only contains
7320 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7321 disassembler (binutils/objdump) to share these routines.
7323 The libiberty library is now copylefted under the GNU Library General
7324 Public License. This allows more liberal use, and was done so libg++
7325 can use it. This makes no difference to GDB, since the Library License
7326 grants all the rights from the General Public License.
7330 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7331 reference to the stabs symbol info used by the debugger. It is (as far
7332 as we know) the only published document on this fascinating topic. We
7333 encourage you to read it, compare it to the stabs information on your
7334 system, and send improvements on the document in general (to
7335 bug-gdb@prep.ai.mit.edu).
7337 And, of course, many bugs have been fixed.
7340 *** Changes in GDB-4.6:
7342 * Better support for C++ function names
7344 GDB now accepts as input the "demangled form" of C++ overloaded function
7345 names and member function names, and can do command completion on such names
7346 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7347 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7348 Make use of command completion, it is your friend.
7350 GDB also now accepts a variety of C++ mangled symbol formats. They are
7351 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7352 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7353 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7354 for the list of formats.
7356 * G++ symbol mangling problem
7358 Recent versions of gcc have a bug in how they emit debugging information for
7359 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7360 directory) can be applied to gcc to fix the problem. Alternatively, if you
7361 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7362 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7363 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7366 * New 'maintenance' command
7368 All of the commands related to hacking GDB internals have been moved out of
7369 the main command set, and now live behind the 'maintenance' command. This
7370 can also be abbreviated as 'mt'. The following changes were made:
7372 dump-me -> maintenance dump-me
7373 info all-breakpoints -> maintenance info breakpoints
7374 printmsyms -> maintenance print msyms
7375 printobjfiles -> maintenance print objfiles
7376 printpsyms -> maintenance print psymbols
7377 printsyms -> maintenance print symbols
7379 The following commands are new:
7381 maintenance demangle Call internal GDB demangler routine to
7382 demangle a C++ link name and prints the result.
7383 maintenance print type Print a type chain for a given symbol
7385 * Change to .gdbinit file processing
7387 We now read the $HOME/.gdbinit file before processing the argv arguments
7388 (e.g. reading symbol files or core files). This allows global parameters to
7389 be set, which will apply during the symbol reading. The ./.gdbinit is still
7390 read after argv processing.
7392 * New hosts supported
7394 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7396 GNU/Linux support i386-unknown-linux or linux
7398 We are also including code to support the HP/PA running BSD and HPUX. This
7399 is almost guaranteed not to work, as we didn't have time to test or build it
7400 for this release. We are including it so that the more adventurous (or
7401 masochistic) of you can play with it. We also had major problems with the
7402 fact that the compiler that we got from HP doesn't support the -g option.
7405 * New targets supported
7407 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7409 * More smarts about finding #include files
7411 GDB now remembers the compilation directory for all include files, and for
7412 all files from which C is generated (like yacc and lex sources). This
7413 greatly improves GDB's ability to find yacc/lex sources, and include files,
7414 especially if you are debugging your program from a directory different from
7415 the one that contains your sources.
7417 We also fixed a bug which caused difficulty with listing and setting
7418 breakpoints in include files which contain C code. (In the past, you had to
7419 try twice in order to list an include file that you hadn't looked at before.)
7421 * Interesting infernals change
7423 GDB now deals with arbitrary numbers of sections, where the symbols for each
7424 section must be relocated relative to that section's landing place in the
7425 target's address space. This work was needed to support ELF with embedded
7426 stabs used by Solaris-2.0.
7428 * Bug fixes (of course!)
7430 There have been loads of fixes for the following things:
7431 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7432 i960, stabs, DOS(GO32), procfs, etc...
7434 See the ChangeLog for details.
7436 *** Changes in GDB-4.5:
7438 * New machines supported (host and target)
7440 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7442 SGI Irix-4.x mips-sgi-irix4 or iris4
7444 * New malloc package
7446 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7447 Mmalloc is capable of handling multiple heaps of memory. It is also
7448 capable of saving a heap to a file, and then mapping it back in later.
7449 This can be used to greatly speedup the startup of GDB by using a
7450 pre-parsed symbol table which lives in a mmalloc managed heap. For
7451 more details, please read mmalloc/mmalloc.texi.
7455 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7456 'help info proc' for details.
7458 * MIPS ecoff symbol table format
7460 The code that reads MIPS symbol table format is now supported on all hosts.
7461 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7464 * File name changes for MS-DOS
7466 Many files in the config directories have been renamed to make it easier to
7467 support GDB on MS-DOSe systems (which have very restrictive file name
7468 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7469 environment) is close to working but has some remaining problems. Note
7470 that debugging of DOS programs is not supported, due to limitations
7471 in the ``operating system'', but it can be used to host cross-debugging.
7473 * Cross byte order fixes
7475 Many fixes have been made to support cross debugging of Sparc and MIPS
7476 targets from hosts whose byte order differs.
7478 * New -mapped and -readnow options
7480 If memory-mapped files are available on your system through the 'mmap'
7481 system call, you can use the -mapped option on the `file' or
7482 `symbol-file' commands to cause GDB to write the symbols from your
7483 program into a reusable file. If the program you are debugging is
7484 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7485 Future GDB debugging sessions will notice the presence of this file,
7486 and will quickly map in symbol information from it, rather than reading
7487 the symbol table from the executable program. Using the '-mapped'
7488 option in a GDB `file' or `symbol-file' command has the same effect as
7489 starting GDB with the '-mapped' command-line option.
7491 You can cause GDB to read the entire symbol table immediately by using
7492 the '-readnow' option with any of the commands that load symbol table
7493 information (or on the GDB command line). This makes the command
7494 slower, but makes future operations faster.
7496 The -mapped and -readnow options are typically combined in order to
7497 build a `fred.syms' file that contains complete symbol information.
7498 A simple GDB invocation to do nothing but build a `.syms' file for future
7501 gdb -batch -nx -mapped -readnow programname
7503 The `.syms' file is specific to the host machine on which GDB is run.
7504 It holds an exact image of GDB's internal symbol table. It cannot be
7505 shared across multiple host platforms.
7507 * longjmp() handling
7509 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7510 siglongjmp() without losing control. This feature has not yet been ported to
7511 all systems. It currently works on many 386 platforms, all MIPS-based
7512 platforms (SGI, DECstation, etc), and Sun3/4.
7516 Preliminary work has been put in to support the new Solaris OS from Sun. At
7517 this time, it can control and debug processes, but it is not capable of
7522 As always, many many bug fixes. The major areas were with g++, and mipsread.
7523 People using the MIPS-based platforms should experience fewer mysterious
7524 crashes and trashed symbol tables.
7526 *** Changes in GDB-4.4:
7528 * New machines supported (host and target)
7530 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7532 BSD Reno on Vax vax-dec-bsd
7533 Ultrix on Vax vax-dec-ultrix
7535 * New machines supported (target)
7537 AMD 29000 embedded, using EBMON a29k-none-none
7541 GDB continues to improve its handling of C++. `References' work better.
7542 The demangler has also been improved, and now deals with symbols mangled as
7543 per the Annotated C++ Reference Guide.
7545 GDB also now handles `stabs' symbol information embedded in MIPS
7546 `ecoff' symbol tables. Since the ecoff format was not easily
7547 extensible to handle new languages such as C++, this appeared to be a
7548 good way to put C++ debugging info into MIPS binaries. This option
7549 will be supported in the GNU C compiler, version 2, when it is
7552 * New features for SVR4
7554 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7555 shared libraries. Debugging dynamically linked programs should present
7556 only minor differences from debugging statically linked programs.
7558 The `info proc' command will print out information about any process
7559 on an SVR4 system (including the one you are debugging). At the moment,
7560 it prints the address mappings of the process.
7562 If you bring up GDB on another SVR4 system, please send mail to
7563 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7565 * Better dynamic linking support in SunOS
7567 Reading symbols from shared libraries which contain debugging symbols
7568 now works properly. However, there remain issues such as automatic
7569 skipping of `transfer vector' code during function calls, which
7570 make it harder to debug code in a shared library, than to debug the
7571 same code linked statically.
7575 GDB is now using the latest `getopt' routines from the FSF. This
7576 version accepts the -- prefix for options with long names. GDB will
7577 continue to accept the old forms (-option and +option) as well.
7578 Various single letter abbreviations for options have been explicity
7579 added to the option table so that they won't get overshadowed in the
7580 future by other options that begin with the same letter.
7584 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7585 Many assorted bugs have been handled. Many more remain to be handled.
7586 See the various ChangeLog files (primarily in gdb and bfd) for details.
7589 *** Changes in GDB-4.3:
7591 * New machines supported (host and target)
7593 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7594 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7595 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7597 * Almost SCO Unix support
7599 We had hoped to support:
7600 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7601 (except for core file support), but we discovered very late in the release
7602 that it has problems with process groups that render gdb unusable. Sorry
7603 about that. I encourage people to fix it and post the fixes.
7605 * Preliminary ELF and DWARF support
7607 GDB can read ELF object files on System V Release 4, and can handle
7608 debugging records for C, in DWARF format, in ELF files. This support
7609 is preliminary. If you bring up GDB on another SVR4 system, please
7610 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7615 GDB now uses the latest `readline' library. One user-visible change
7616 is that two tabs will list possible command completions, which previously
7617 required typing M-? (meta-question mark, or ESC ?).
7621 The `stepi' bug that many of you noticed has been squashed.
7622 Many bugs in C++ have been handled. Many more remain to be handled.
7623 See the various ChangeLog files (primarily in gdb and bfd) for details.
7625 * State of the MIPS world (in case you wondered):
7627 GDB can understand the symbol tables emitted by the compilers
7628 supplied by most vendors of MIPS-based machines, including DEC. These
7629 symbol tables are in a format that essentially nobody else uses.
7631 Some versions of gcc come with an assembler post-processor called
7632 mips-tfile. This program is required if you want to do source-level
7633 debugging of gcc-compiled programs. I believe FSF does not ship
7634 mips-tfile with gcc version 1, but it will eventually come with gcc
7637 Debugging of g++ output remains a problem. g++ version 1.xx does not
7638 really support it at all. (If you're lucky, you should be able to get
7639 line numbers and stack traces to work, but no parameters or local
7640 variables.) With some work it should be possible to improve the
7643 When gcc version 2 is released, you will have somewhat better luck.
7644 However, even then you will get confusing results for inheritance and
7647 We will eventually provide full debugging of g++ output on
7648 DECstations. This will probably involve some kind of stabs-in-ecoff
7649 encapulation, but the details have not been worked out yet.
7652 *** Changes in GDB-4.2:
7654 * Improved configuration
7656 Only one copy of `configure' exists now, and it is not self-modifying.
7657 Porting BFD is simpler.
7661 The `step' and `next' commands now only stop at the first instruction
7662 of a source line. This prevents the multiple stops that used to occur
7663 in switch statements, for-loops, etc. `Step' continues to stop if a
7664 function that has debugging information is called within the line.
7668 Lots of small bugs fixed. More remain.
7670 * New host supported (not target)
7672 Intel 386 PC clone running Mach i386-none-mach
7675 *** Changes in GDB-4.1:
7677 * Multiple source language support
7679 GDB now has internal scaffolding to handle several source languages.
7680 It determines the type of each source file from its filename extension,
7681 and will switch expression parsing and number formatting to match the
7682 language of the function in the currently selected stack frame.
7683 You can also specifically set the language to be used, with
7684 `set language c' or `set language modula-2'.
7688 GDB now has preliminary support for the GNU Modula-2 compiler,
7689 currently under development at the State University of New York at
7690 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7691 continue through the fall of 1991 and into 1992.
7693 Other Modula-2 compilers are currently not supported, and attempting to
7694 debug programs compiled with them will likely result in an error as the
7695 symbol table is read. Feel free to work on it, though!
7697 There are hooks in GDB for strict type checking and range checking,
7698 in the `Modula-2 philosophy', but they do not currently work.
7702 GDB can now write to executable and core files (e.g. patch
7703 a variable's value). You must turn this switch on, specify
7704 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7705 by assigning a new value to a variable. Modifications take
7708 * Automatic SunOS shared library reading
7710 When you run your program, GDB automatically determines where its
7711 shared libraries (if any) have been loaded, and reads their symbols.
7712 The `share' command is no longer needed. This also works when
7713 examining core files.
7717 You can specify the number of lines that the `list' command shows.
7720 * New machines supported (host and target)
7722 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7723 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7724 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7726 * New hosts supported (not targets)
7728 IBM RT/PC: romp-ibm-aix or rtpc
7730 * New targets supported (not hosts)
7732 AMD 29000 embedded with COFF a29k-none-coff
7733 AMD 29000 embedded with a.out a29k-none-aout
7734 Ultracomputer remote kernel debug a29k-nyu-kern
7736 * New remote interfaces
7742 *** Changes in GDB-4.0:
7746 Wide output is wrapped at good places to make the output more readable.
7748 Gdb now supports cross-debugging from a host machine of one type to a
7749 target machine of another type. Communication with the target system
7750 is over serial lines. The ``target'' command handles connecting to the
7751 remote system; the ``load'' command will download a program into the
7752 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7753 also supports debugging of realtime processes running under VxWorks,
7754 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7755 stub on the target system.
7757 New CPUs supported include the AMD 29000 and Intel 960.
7759 GDB now reads object files and symbol tables via a ``binary file''
7760 library, which allows a single copy of GDB to debug programs of multiple
7761 object file types such as a.out and coff.
7763 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7764 refcard.dvi and refcard.ps are available to format it).
7767 * Control-Variable user interface simplified
7769 All variables that control the operation of the debugger can be set
7770 by the ``set'' command, and displayed by the ``show'' command.
7772 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7773 ``Show prompt'' produces the response:
7774 Gdb's prompt is new-gdb=>.
7776 What follows are the NEW set commands. The command ``help set'' will
7777 print a complete list of old and new set commands. ``help set FOO''
7778 will give a longer description of the variable FOO. ``show'' will show
7779 all of the variable descriptions and their current settings.
7781 confirm on/off: Enables warning questions for operations that are
7782 hard to recover from, e.g. rerunning the program while
7783 it is already running. Default is ON.
7785 editing on/off: Enables EMACS style command line editing
7786 of input. Previous lines can be recalled with
7787 control-P, the current line can be edited with control-B,
7788 you can search for commands with control-R, etc.
7791 history filename NAME: NAME is where the gdb command history
7792 will be stored. The default is .gdb_history,
7793 or the value of the environment variable
7796 history size N: The size, in commands, of the command history. The
7797 default is 256, or the value of the environment variable
7800 history save on/off: If this value is set to ON, the history file will
7801 be saved after exiting gdb. If set to OFF, the
7802 file will not be saved. The default is OFF.
7804 history expansion on/off: If this value is set to ON, then csh-like
7805 history expansion will be performed on
7806 command line input. The default is OFF.
7808 radix N: Sets the default radix for input and output. It can be set
7809 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7810 in the current radix, so "set radix 10" is always a no-op.
7812 height N: This integer value is the number of lines on a page. Default
7813 is 24, the current `stty rows'' setting, or the ``li#''
7814 setting from the termcap entry matching the environment
7817 width N: This integer value is the number of characters on a line.
7818 Default is 80, the current `stty cols'' setting, or the ``co#''
7819 setting from the termcap entry matching the environment
7822 Note: ``set screensize'' is obsolete. Use ``set height'' and
7823 ``set width'' instead.
7825 print address on/off: Print memory addresses in various command displays,
7826 such as stack traces and structure values. Gdb looks
7827 more ``symbolic'' if you turn this off; it looks more
7828 ``machine level'' with it on. Default is ON.
7830 print array on/off: Prettyprint arrays. New convenient format! Default
7833 print demangle on/off: Print C++ symbols in "source" form if on,
7836 print asm-demangle on/off: Same, for assembler level printouts
7839 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7842 * Support for Epoch Environment.
7844 The epoch environment is a version of Emacs v18 with windowing. One
7845 new command, ``inspect'', is identical to ``print'', except that if you
7846 are running in the epoch environment, the value is printed in its own
7850 * Support for Shared Libraries
7852 GDB can now debug programs and core files that use SunOS shared libraries.
7853 Symbols from a shared library cannot be referenced
7854 before the shared library has been linked with the program (this
7855 happens after you type ``run'' and before the function main() is entered).
7856 At any time after this linking (including when examining core files
7857 from dynamically linked programs), gdb reads the symbols from each
7858 shared library when you type the ``sharedlibrary'' command.
7859 It can be abbreviated ``share''.
7861 sharedlibrary REGEXP: Load shared object library symbols for files
7862 matching a unix regular expression. No argument
7863 indicates to load symbols for all shared libraries.
7865 info sharedlibrary: Status of loaded shared libraries.
7870 A watchpoint stops execution of a program whenever the value of an
7871 expression changes. Checking for this slows down execution
7872 tremendously whenever you are in the scope of the expression, but is
7873 quite useful for catching tough ``bit-spreader'' or pointer misuse
7874 problems. Some machines such as the 386 have hardware for doing this
7875 more quickly, and future versions of gdb will use this hardware.
7877 watch EXP: Set a watchpoint (breakpoint) for an expression.
7879 info watchpoints: Information about your watchpoints.
7881 delete N: Deletes watchpoint number N (same as breakpoints).
7882 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7883 enable N: Re-enables watchpoint number N (same as breakpoints).
7886 * C++ multiple inheritance
7888 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7891 * C++ exception handling
7893 Gdb now supports limited C++ exception handling. Besides the existing
7894 ability to breakpoint on an exception handler, gdb can breakpoint on
7895 the raising of an exception (before the stack is peeled back to the
7898 catch FOO: If there is a FOO exception handler in the dynamic scope,
7899 set a breakpoint to catch exceptions which may be raised there.
7900 Multiple exceptions (``catch foo bar baz'') may be caught.
7902 info catch: Lists all exceptions which may be caught in the
7903 current stack frame.
7906 * Minor command changes
7908 The command ``call func (arg, arg, ...)'' now acts like the print
7909 command, except it does not print or save a value if the function's result
7910 is void. This is similar to dbx usage.
7912 The ``up'' and ``down'' commands now always print the frame they end up
7913 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7914 frames without printing.
7916 * New directory command
7918 'dir' now adds directories to the FRONT of the source search path.
7919 The path starts off empty. Source files that contain debug information
7920 about the directory in which they were compiled can be found even
7921 with an empty path; Sun CC and GCC include this information. If GDB can't
7922 find your source file in the current directory, type "dir .".
7924 * Configuring GDB for compilation
7926 For normal use, type ``./configure host''. See README or gdb.texinfo
7929 GDB now handles cross debugging. If you are remotely debugging between
7930 two different machines, type ``./configure host -target=targ''.
7931 Host is the machine where GDB will run; targ is the machine
7932 where the program that you are debugging will run.