1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
7 debugging information as well as source code.
9 When built with debuginfod, GDB can automatically query debuginfod
10 servers for the separate debug files and source code of the executable
13 To build GDB with debuginfod, pass --with-debuginfod to configure (this
14 requires libdebuginfod, the debuginfod client library).
16 debuginfod is distributed with elfutils, starting with version 0.178.
18 You can get the latest version from https://sourceware.org/elfutils.
20 * New features in the GDB remote stub, GDBserver
22 ** GDBserver is now supported on RISC-V GNU/Linux.
24 * Debugging MS-Windows processes now sets $_exitsignal when the
25 inferior is terminated by a signal, instead of setting $_exitcode.
27 * Multithreaded symbol loading has now been enabled by default on systems
28 that support it (see entry for GDB 9, below), providing faster
29 performance for programs with many symbols.
31 * The $_siginfo convenience variable now also works on Windows targets,
32 and will display the EXCEPTION_RECORD of the last handled exception.
34 * TUI windows can now be arranged horizontally.
36 * The command history filename can now be set to the empty string
37 either using 'set history filename' or by setting 'GDBHISTFILE=' in
38 the environment. The effect of setting this filename to the empty
39 string is that GDB will not try to load any previous command
42 * On Windows targets, it is now possible to debug 32-bit programs with a
47 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
48 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
49 Set or show the option 'exec-file-mismatch'. When GDB attaches to
50 a running process and can determine the name of the executable file
51 the process runs, this new option indicates whether to detect mismatch
52 between the name of the current executable file loaded by GDB
53 and the name of the executable file used to start the process.
54 If 'ask', the default, display a warning and ask the user
55 whether to load the process executable file; if 'warn', just display
56 a warning; if 'off', don't attempt to detect a mismatch.
58 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
59 Define a new TUI layout, specifying its name and the windows that
64 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
68 ** gdb.register_window_type can be used to implement new TUI windows
71 ** Dynamic types can now be queried. gdb.Type has a new attribute,
72 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
73 field of a dynamic type may have None for its "bitpos" attribute
78 * 'thread-exited' event is now available in the annotations interface.
80 * New built-in convenience variables $_gdb_major and $_gdb_minor
81 provide the GDB version. They are handy for conditionally using
82 features available only in or since specific GDB versions, in
83 scripts that should work error-free with many different versions,
84 such as in system-wide init files.
86 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
87 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
88 of the GDB settings and the GDB maintenance settings. They are handy
89 for changing the logic of user defined commands depending on the
92 * GDB now supports Thread Local Storage (TLS) variables on several
93 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
94 architectures require kernel changes. TLS is not yet supported for
95 amd64 and i386 process core dumps.
97 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
98 addresses that required unmasking are shown in the backtrace with the
101 * Two new convenience functions $_cimag and $_creal that extract the
102 imaginary and real parts respectively from complex numbers.
104 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
105 provide the exitcode or exit status of the shell commands launched by
106 GDB commands such as "shell", "pipe" and "make".
108 * The command define-prefix can now define user defined prefix commands.
109 User defined commands can now be defined using these user defined prefix
112 * Command names can now use the . character.
114 * The RX port now supports XML target descriptions.
116 * GDB now shows the Ada task names at more places, e.g. in task switching
119 * GDB can now be compiled with Python 3 on Windows.
121 * New convenience variable $_ada_exception holds the address of the
122 Ada exception being thrown. This is set by Ada-related catchpoints.
124 * GDB can now place breakpoints on nested functions and subroutines in
125 Fortran code. The '::' operator can be used between parent and
126 child scopes when placing breakpoints, for example:
128 (gdb) break outer_function::inner_function
130 The 'outer_function::' prefix is only needed if 'inner_function' is
131 not visible in the current scope.
133 * In addition to the system-wide gdbinit file, if configured with
134 --with-system-gdbinit-dir, GDB will now also load files in that directory
135 as system gdbinit files, unless the -nx or -n flag is provided. Files
136 with extensions .gdb, .py and .scm are supported as long as GDB was
137 compiled with support for that language.
139 * GDB now supports multithreaded symbol loading for higher performance.
140 This feature is still in testing, so it is disabled by default. You
141 can turn it on using 'maint set worker-threads unlimited'.
143 * Multi-target debugging support
145 GDB now supports debugging multiple target connections
146 simultaneously. For example, you can now have each inferior
147 connected to different remote servers running in different machines,
148 or have one inferior debugging a local native process, an inferior
149 debugging a core dump, etc.
151 This support is experimental and comes with some limitations -- you
152 can only resume multiple targets simultaneously if all targets
153 support non-stop mode, and all remote stubs or servers must support
154 the same set of remote protocol features exactly. See also "info
155 connections" and "add-inferior -no-connection" below, and "maint set
156 target-non-stop" in the user manual.
160 ** The gdb.Value type has a new method 'format_string' which returns a
161 string representing the value. The formatting is controlled by the
162 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
163 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
164 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
166 ** gdb.Type has a new property 'objfile' which returns the objfile the
169 ** The frame information printed by the python frame filtering code
170 is now consistent with what the 'backtrace' command prints when
171 there are no filters, or when the 'backtrace' '-no-filters' option
174 ** The new function gdb.lookup_static_symbol can be used to look up
175 symbols with static linkage.
177 ** The new function gdb.lookup_static_symbols can be used to look up
178 all static symbols with static linkage.
180 ** gdb.Objfile has new methods 'lookup_global_symbol' and
181 'lookup_static_symbol' to lookup a symbol from this objfile only.
183 ** gdb.Block now supports the dictionary syntax for accessing symbols in
184 this block (e.g. block['local_variable']).
188 | [COMMAND] | SHELL_COMMAND
189 | -d DELIM COMMAND DELIM SHELL_COMMAND
190 pipe [COMMAND] | SHELL_COMMAND
191 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
192 Executes COMMAND and sends its output to SHELL_COMMAND.
193 With no COMMAND, repeat the last executed command
194 and send its output to SHELL_COMMAND.
196 define-prefix COMMAND
197 Define or mark a command as a user-defined prefix command.
199 with SETTING [VALUE] [-- COMMAND]
200 w SETTING [VALUE] [-- COMMAND]
201 Temporarily set SETTING, run COMMAND, and restore SETTING.
202 Usage: with SETTING -- COMMAND
203 With no COMMAND, repeats the last executed command.
204 SETTING is any GDB setting you can change with the "set"
205 subcommands. For example, 'with language c -- print someobj'
206 temporarily switches to the C language in order to print someobj.
207 Settings can be combined: 'w lang c -- w print elements unlimited --
208 usercmd' switches to the C language and runs usercmd with no limit
209 of array elements to print.
211 maint with SETTING [VALUE] [-- COMMAND]
212 Like "with", but works with "maintenance set" settings.
214 set may-call-functions [on|off]
215 show may-call-functions
216 This controls whether GDB will attempt to call functions in
217 the program, such as with expressions in the print command. It
218 defaults to on. Calling functions in the program being debugged
219 can have undesired side effects. It is now possible to forbid
220 such function calls. If function calls are forbidden, GDB will throw
221 an error when a command (such as print expression) calls a function
224 set print finish [on|off]
226 This controls whether the `finish' command will display the value
227 that is returned by the current function. When `off', the value is
228 still entered into the value history, but it is not printed. The
233 Allows deeply nested structures to be simplified when printing by
234 replacing deeply nested parts (beyond the max-depth) with ellipses.
235 The default max-depth is 20, but this can be set to unlimited to get
236 the old behavior back.
238 set print raw-values [on|off]
239 show print raw-values
240 By default, GDB applies the enabled pretty printers when printing a
241 value. This allows to ignore the enabled pretty printers for a series
242 of commands. The default is 'off'.
244 set logging debugredirect [on|off]
245 By default, GDB debug output will go to both the terminal and the logfile.
246 Set if you want debug output to go only to the log file.
248 set style title foreground COLOR
249 set style title background COLOR
250 set style title intensity VALUE
251 Control the styling of titles.
253 set style highlight foreground COLOR
254 set style highlight background COLOR
255 set style highlight intensity VALUE
256 Control the styling of highlightings.
258 maint set worker-threads
259 maint show worker-threads
260 Control the number of worker threads that can be used by GDB. The
261 default is 0. "unlimited" lets GDB choose a number that is
262 reasonable. Currently worker threads are only used when demangling
263 the names of linker symbols.
265 set style tui-border foreground COLOR
266 set style tui-border background COLOR
267 Control the styling of TUI borders.
269 set style tui-active-border foreground COLOR
270 set style tui-active-border background COLOR
271 Control the styling of the active TUI border.
273 maint set test-settings KIND
274 maint show test-settings KIND
275 A set of commands used by the testsuite for exercising the settings
278 maint set tui-resize-message [on|off]
279 maint show tui-resize-message
280 Control whether GDB prints a message each time the terminal is
281 resized when in TUI mode. This is primarily useful for testing the
284 set print frame-info [short-location|location|location-and-address
285 |source-and-location|source-line|auto]
286 show print frame-info
287 This controls what frame information is printed by the commands printing
288 a frame. This setting will e.g. influence the behaviour of 'backtrace',
289 'frame', 'stepi'. The python frame filtering also respect this setting.
290 The 'backtrace' '-frame-info' option can override this global setting.
292 set tui compact-source
293 show tui compact-source
295 Enable the "compact" display mode for the TUI source window. The
296 compact display uses only as much space as is needed for the line
297 numbers in the current file, and only a single space to separate the
298 line numbers from the source.
300 info modules [-q] [REGEXP]
301 Return a list of Fortran modules matching REGEXP, or all modules if
304 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
305 Return a list of functions within all modules, grouped by module.
306 The list of functions can be restricted with the optional regular
307 expressions. MODULE_REGEXP matches against the module name,
308 TYPE_REGEXP matches against the function type signature, and REGEXP
309 matches against the function name.
311 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
312 Return a list of variables within all modules, grouped by module.
313 The list of variables can be restricted with the optional regular
314 expressions. MODULE_REGEXP matches against the module name,
315 TYPE_REGEXP matches against the variable type, and REGEXP matches
316 against the variable name.
318 set debug remote-packet-max-chars
319 show debug remote-packet-max-chars
320 Controls the number of characters to output in a remote packet when using
322 The default is 512 bytes.
325 Lists the target connections currently in use.
330 The "help" command uses the title style to enhance the
331 readibility of its output by styling the classes and
335 Similarly to "help", the "apropos" command also uses the
336 title style for the command names. "apropos" accepts now
337 a flag "-v" (verbose) to show the full documentation
338 of matching commands and to use the highlight style to mark
339 the documentation parts matching REGEXP.
343 The GDB printf and eval commands can now print C-style and Ada-style
344 string convenience variables without calling functions in the program.
345 This allows to do formatted printing of strings without having
346 a running inferior, or when debugging a core dump.
348 info sources [-dirname | -basename] [--] [REGEXP]
349 This command has now optional arguments to only print the files
350 whose names match REGEXP. The arguments -dirname and -basename
351 allow to restrict matching respectively to the dirname and basename
355 The "show style" and its subcommands are now styling
356 a style name in their output using its own style, to help
357 the user visualize the different styles.
359 set print frame-arguments
360 The new value 'presence' indicates to only indicate the presence of
361 arguments using ..., instead of printing argument names and values.
363 set print raw-frame-arguments
364 show print raw-frame-arguments
366 These commands replace the similarly-named "set/show print raw
367 frame-arguments" commands (now with a dash instead of a space). The
368 old commands are now deprecated and may be removed in a future
371 add-inferior [-no-connection]
372 The add-inferior command now supports a "-no-connection" flag that
373 makes the new inferior start with no target connection associated.
374 By default, the new inferior inherits the target connection of the
375 current inferior. See also "info connections".
378 This command's output now includes a new "Connection" column
379 indicating which target connection an inferior is bound to. See
380 "info connections" above.
382 maint test-options require-delimiter
383 maint test-options unknown-is-error
384 maint test-options unknown-is-operand
385 maint show test-options-completion-result
386 Commands used by the testsuite to validate the command options
389 focus, winheight, +, -, >, <
390 These commands are now case-sensitive.
392 * New command options, command completion
394 GDB now has a standard infrastructure to support dash-style command
395 options ('-OPT'). One benefit is that commands that use it can
396 easily support completion of command line arguments. Try "CMD
397 -[TAB]" or "help CMD" to find options supported by a command. Over
398 time, we intend to migrate most commands to this infrastructure. A
399 number of commands got support for new command options in this
402 ** The "print" and "compile print" commands now support a number of
403 options that allow overriding relevant global print settings as
404 set by "set print" subcommands:
408 -array-indexes [on|off]
409 -elements NUMBER|unlimited
414 -repeats NUMBER|unlimited
415 -static-members [on|off]
420 Note that because the "print"/"compile print" commands accept
421 arbitrary expressions which may look like options (including
422 abbreviations), if you specify any command option, then you must
423 use a double dash ("--") to mark the end of argument processing.
425 ** The "backtrace" command now supports a number of options that
426 allow overriding relevant global print settings as set by "set
427 backtrace" and "set print" subcommands:
429 -entry-values no|only|preferred|if-needed|both|compact|default
430 -frame-arguments all|scalars|none
431 -raw-frame-arguments [on|off]
432 -frame-info auto|source-line|location|source-and-location
433 |location-and-address|short-location
437 In addition, the full/no-filters/hide qualifiers are now also
438 exposed as command options too:
444 ** The "frame apply", "tfaas" and "faas" commands similarly now
445 support the following options:
450 ** The new "info sources" options -dirname and -basename options
451 are using the standard '-OPT' infrastructure.
453 All options above can also be abbreviated. The argument of boolean
454 (on/off) options can be 0/1 too, and also the argument is assumed
455 "on" if omitted. This allows writing compact command invocations,
458 (gdb) p -ra -p -o 0 -- *myptr
460 The above is equivalent to:
462 (gdb) print -raw-values -pretty -object off -- *myptr
464 ** The "info types" command now supports the '-q' flag to disable
465 printing of some header information in a similar fashion to "info
466 variables" and "info functions".
468 ** The "info variables", "info functions", and "whereis" commands
469 now take a '-n' flag that excludes non-debug symbols (symbols
470 from the symbol table, not from the debug info such as DWARF)
473 * Completion improvements
475 ** GDB can now complete the options of the "thread apply all" and
476 "taas" commands, and their "-ascending" option can now be
479 ** GDB can now complete the options of the "info threads", "info
480 functions", "info variables", "info locals", and "info args"
483 ** GDB can now complete the options of the "compile file" and
484 "compile code" commands. The "compile file" command now
485 completes on filenames.
487 ** GDB can now complete the backtrace command's
488 "full/no-filters/hide" qualifiers.
490 * In settings, you can now abbreviate "unlimited".
492 E.g., "set print elements u" is now equivalent to "set print
498 This lists all the possible completions for the rest of the line, if it
499 were to be given as a command itself. This is intended for use by MI
500 frontends in cases when separate CLI and MI channels cannot be used.
502 -catch-throw, -catch-rethrow, and -catch-catch
503 These can be used to catch C++ exceptions in a similar fashion to
504 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
506 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
507 These commands are the MI equivalent of the CLI commands 'info
508 functions', 'info types', and 'info variables' respectively.
510 -symbol-info-modules, this is the MI equivalent of the CLI 'info
513 -symbol-info-module-functions and -symbol-info-module-variables.
514 These commands are the MI equivalent of the CLI commands 'info
515 module functions' and 'info module variables'.
519 ** The default version of the MI interpreter is now 3 (-i=mi3).
521 ** The output of information about multi-location breakpoints (which is
522 syntactically incorrect in MI 2) has changed in MI 3. This affects
523 the following commands and events:
527 - =breakpoint-created
528 - =breakpoint-modified
530 The -fix-multi-location-breakpoint-output command can be used to enable
531 this behavior with previous MI versions.
533 ** Backtraces and frames include a new optional field addr_flags which is
534 given after the addr field. On AArch64 this contains PAC if the address
535 has been masked in the frame. On all other targets the field is not
540 The testsuite now creates the files gdb.cmd (containing the arguments
541 used to launch GDB) and gdb.in (containing all the commands sent to
542 GDB) in the output directory for each test script. Multiple invocations
543 are appended with .1, .2, .3 etc.
545 * Building GDB and GDBserver now requires GNU make >= 3.82.
547 Using another implementation of the make program or an earlier version of
548 GNU make to build GDB or GDBserver is not supported.
550 * Building GDB now requires GNU readline >= 7.0.
552 GDB now bundles GNU readline 8.0, but if you choose to use
553 --with-system-readline, only readline >= 7.0 can be used.
555 * The TUI SingleKey keymap is now named "SingleKey". This can be used
556 from .inputrc to bind keys in this keymap. This feature is only
557 available when gdb is built against GNU readline 8.0 or later.
559 * Removed targets and native configurations
561 GDB no longer supports debugging the Cell Broadband Engine. This includes
562 both debugging standalone Cell/B.E. SPU applications and integrated debugging
563 of Cell/B.E. applications that use both the PPU and SPU architectures.
569 * Removed targets and native configurations
571 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
574 *** Changes in GDB 8.3
576 * GDB and GDBserver now support access to additional registers on
577 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
580 * GDB now has experimental support for the compilation and injection of
581 C++ source code into the inferior. This beta release does not include
582 support for several language features, such as templates, constructors,
585 This feature requires GCC 7.1 or higher built with libcp1.so
588 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
589 can be passed using the '[ADDRESS]:PORT' notation, or the regular
590 'ADDRESS:PORT' method.
592 * DWARF index cache: GDB can now automatically save indices of DWARF
593 symbols on disk to speed up further loading of the same binaries.
595 * Ada task switching is now supported on aarch64-elf targets when
596 debugging a program using the Ravenscar Profile. For more information,
597 see the "Tasking Support when using the Ravenscar Profile" section
598 in the GDB user manual.
600 * GDB in batch mode now exits with status 1 if the last command to be
603 * The RISC-V target now supports target descriptions.
605 * System call catchpoints now support system call aliases on FreeBSD.
606 When the ABI of a system call changes in FreeBSD, this is
607 implemented by leaving a compatibility system call using the old ABI
608 at the existing number and allocating a new system call number for
609 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
610 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
611 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
612 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
613 so that a system call catchpoint for the 'kevent' system call will
614 catch invocations of both the 'kevent' and 'freebsd11_kevent'
615 binaries. This ensures that 'kevent' system calls are caught for
616 binaries using either the old or new ABIs.
618 * Terminal styling is now available for the CLI and the TUI. GNU
619 Source Highlight can additionally be used to provide styling of
620 source code snippets. See the "set style" commands, below, for more
623 * Removed support for old demangling styles arm, edg, gnu, hp and
628 set debug compile-cplus-types
629 show debug compile-cplus-types
630 Control the display of debug output about type conversion in the
631 C++ compile feature. Commands have no effect while compiliong
636 Control whether debug output about files/functions skipping is
639 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
640 Apply a command to some frames.
641 FLAG arguments allow to control what output to produce and how to handle
642 errors raised when applying COMMAND to a frame.
645 Apply a command to all threads (ignoring errors and empty output).
646 Shortcut for 'thread apply all -s COMMAND'.
649 Apply a command to all frames (ignoring errors and empty output).
650 Shortcut for 'frame apply all -s COMMAND'.
653 Apply a command to all frames of all threads (ignoring errors and empty
655 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
657 maint set dwarf unwinders (on|off)
658 maint show dwarf unwinders
659 Control whether DWARF unwinders can be used.
662 Display a list of open files for a process.
666 Changes to the "frame", "select-frame", and "info frame" CLI commands.
667 These commands all now take a frame specification which
668 is either a frame level, or one of the keywords 'level', 'address',
669 'function', or 'view' followed by a parameter. Selecting a frame by
670 address, or viewing a frame outside the current backtrace now
671 requires the use of a keyword. Selecting a frame by level is
672 unchanged. The MI comment "-stack-select-frame" is unchanged.
674 target remote FILENAME
675 target extended-remote FILENAME
676 If FILENAME is a Unix domain socket, GDB will attempt to connect
677 to this socket instead of opening FILENAME as a character device.
679 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
680 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
681 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
682 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
683 These commands can now print only the searched entities
684 matching the provided regexp(s), giving a condition
685 on the entity names or entity types. The flag -q disables
686 printing headers or informations messages.
692 These commands now determine the syntax for the shown entities
693 according to the language chosen by `set language'. In particular,
694 `set language auto' means to automatically choose the language of
697 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
698 The 'thread apply' command accepts new FLAG arguments.
699 FLAG arguments allow to control what output to produce and how to handle
700 errors raised when applying COMMAND to a thread.
702 set tui tab-width NCHARS
703 show tui tab-width NCHARS
704 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
706 set style enabled [on|off]
708 Enable or disable terminal styling. Styling is enabled by default
709 on most hosts, but disabled by default when in batch mode.
711 set style sources [on|off]
713 Enable or disable source code styling. Source code styling is
714 enabled by default, but only takes effect if styling in general is
715 enabled, and if GDB was linked with GNU Source Highlight.
717 set style filename foreground COLOR
718 set style filename background COLOR
719 set style filename intensity VALUE
720 Control the styling of file names.
722 set style function foreground COLOR
723 set style function background COLOR
724 set style function intensity VALUE
725 Control the styling of function names.
727 set style variable foreground COLOR
728 set style variable background COLOR
729 set style variable intensity VALUE
730 Control the styling of variable names.
732 set style address foreground COLOR
733 set style address background COLOR
734 set style address intensity VALUE
735 Control the styling of addresses.
739 ** The '-data-disassemble' MI command now accepts an '-a' option to
740 disassemble the whole function surrounding the given program
741 counter value or function name. Support for this feature can be
742 verified by using the "-list-features" command, which should
743 contain "data-disassemble-a-option".
745 ** Command responses and notifications that include a frame now include
746 the frame's architecture in a new "arch" attribute.
748 * New native configurations
750 GNU/Linux/RISC-V riscv*-*-linux*
751 FreeBSD/riscv riscv*-*-freebsd*
755 GNU/Linux/RISC-V riscv*-*-linux*
757 CSKY GNU/LINUX csky*-*-linux
758 FreeBSD/riscv riscv*-*-freebsd*
760 GNU/Linux/OpenRISC or1k*-*-linux*
764 GDB no longer supports native debugging on versions of MS-Windows
769 ** GDB no longer supports Python versions less than 2.6.
771 ** The gdb.Inferior type has a new 'progspace' property, which is the program
772 space associated to that inferior.
774 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
775 of objfiles associated to that program space.
777 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
778 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
781 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
782 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
783 correct and did not work properly.
785 ** The gdb.Value type has a new constructor, which is used to construct a
786 gdb.Value from a Python buffer object and a gdb.Type.
792 Enable or disable the undefined behavior sanitizer. This is
793 disabled by default, but passing --enable-ubsan=yes or
794 --enable-ubsan=auto to configure will enable it. Enabling this can
795 cause a performance penalty. The undefined behavior sanitizer was
796 first introduced in GCC 4.9.
798 *** Changes in GDB 8.2
800 * The 'set disassembler-options' command now supports specifying options
803 * The 'symbol-file' command now accepts an '-o' option to add a relative
804 offset to all sections.
806 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
807 a relative offset to all sections, but it allows to override the load
808 address of individual sections using '-s'.
810 * The 'add-symbol-file' command no longer requires the second argument
811 (address of the text section).
813 * The endianness used with the 'set endian auto' mode in the absence of
814 an executable selected for debugging is now the last endianness chosen
815 either by one of the 'set endian big' and 'set endian little' commands
816 or by inferring from the last executable used, rather than the startup
819 * The pager now allows a "c" response, meaning to disable the pager
820 for the rest of the current command.
822 * The commands 'info variables/functions/types' now show the source line
823 numbers of symbol definitions when available.
825 * 'info proc' now works on running processes on FreeBSD systems and core
826 files created on FreeBSD systems.
828 * C expressions can now use _Alignof, and C++ expressions can now use
831 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
832 the vector length while the process is running.
838 Control display of debugging info regarding the FreeBSD native target.
840 set|show varsize-limit
841 This new setting allows the user to control the maximum size of Ada
842 objects being printed when those objects have a variable type,
843 instead of that maximum size being hardcoded to 65536 bytes.
845 set|show record btrace cpu
846 Controls the processor to be used for enabling errata workarounds for
849 maint check libthread-db
850 Run integrity checks on the current inferior's thread debugging
853 maint set check-libthread-db (on|off)
854 maint show check-libthread-db
855 Control whether to run integrity checks on inferior specific thread
856 debugging libraries as they are loaded. The default is not to
861 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
863 ** The commands attached to a breakpoint can be set by assigning to
864 the breakpoint's "commands" field.
866 ** gdb.execute can now execute multi-line gdb commands.
868 ** The new functions gdb.convenience_variable and
869 gdb.set_convenience_variable can be used to get and set the value
870 of convenience variables.
872 ** A gdb.Parameter will no longer print the "set" help text on an
873 ordinary "set"; instead by default a "set" will be silent unless
874 the get_set_string method returns a non-empty string.
878 RiscV ELF riscv*-*-elf
880 * Removed targets and native configurations
882 m88k running OpenBSD m88*-*-openbsd*
883 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
884 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
885 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
887 * Aarch64/Linux hardware watchpoints improvements
889 Hardware watchpoints on unaligned addresses are now properly
890 supported when running Linux kernel 4.10 or higher: read and access
891 watchpoints are no longer spuriously missed, and all watchpoints
892 lengths between 1 and 8 bytes are supported. On older kernels,
893 watchpoints set on unaligned addresses are no longer missed, with
894 the tradeoff that there is a possibility of false hits being
899 --enable-codesign=CERT
900 This can be used to invoke "codesign -s CERT" after building gdb.
901 This option is useful on macOS, where code signing is required for
902 gdb to work properly.
904 --disable-gdbcli has been removed
905 This is now silently accepted, but does nothing.
907 *** Changes in GDB 8.1
909 * GDB now supports dynamically creating arbitrary register groups specified
910 in XML target descriptions. This allows for finer grain grouping of
911 registers on systems with a large amount of registers.
913 * The 'ptype' command now accepts a '/o' flag, which prints the
914 offsets and sizes of fields in a struct, like the pahole(1) tool.
916 * New "--readnever" command line option instructs GDB to not read each
917 symbol file's symbolic debug information. This makes startup faster
918 but at the expense of not being able to perform symbolic debugging.
919 This option is intended for use cases where symbolic debugging will
920 not be used, e.g., when you only need to dump the debuggee's core.
922 * GDB now uses the GNU MPFR library, if available, to emulate target
923 floating-point arithmetic during expression evaluation when the target
924 uses different floating-point formats than the host. At least version
925 3.1 of GNU MPFR is required.
927 * GDB now supports access to the guarded-storage-control registers and the
928 software-based guarded-storage broadcast control registers on IBM z14.
930 * On Unix systems, GDB now supports transmitting environment variables
931 that are to be set or unset to GDBserver. These variables will
932 affect the environment to be passed to the remote inferior.
934 To inform GDB of environment variables that are to be transmitted to
935 GDBserver, use the "set environment" command. Only user set
936 environment variables are sent to GDBserver.
938 To inform GDB of environment variables that are to be unset before
939 the remote inferior is started by the GDBserver, use the "unset
940 environment" command.
942 * Completion improvements
944 ** GDB can now complete function parameters in linespecs and
945 explicit locations without quoting. When setting breakpoints,
946 quoting around functions names to help with TAB-completion is
947 generally no longer necessary. For example, this now completes
950 (gdb) b function(in[TAB]
951 (gdb) b function(int)
953 Related, GDB is no longer confused with completing functions in
954 C++ anonymous namespaces:
957 (gdb) b (anonymous namespace)::[TAB][TAB]
958 (anonymous namespace)::a_function()
959 (anonymous namespace)::b_function()
961 ** GDB now has much improved linespec and explicit locations TAB
962 completion support, that better understands what you're
963 completing and offers better suggestions. For example, GDB no
964 longer offers data symbols as possible completions when you're
965 setting a breakpoint.
967 ** GDB now TAB-completes label symbol names.
969 ** The "complete" command now mimics TAB completion accurately.
971 * New command line options (gcore)
974 Dump all memory mappings.
976 * Breakpoints on C++ functions are now set on all scopes by default
978 By default, breakpoints on functions/methods are now interpreted as
979 specifying all functions with the given name ignoring missing
980 leading scopes (namespaces and classes).
982 For example, assuming a C++ program with symbols named:
987 both commands "break func()" and "break B::func()" set a breakpoint
990 You can use the new flag "-qualified" to override this. This makes
991 GDB interpret the specified function name as a complete
992 fully-qualified name instead. For example, using the same C++
993 program, the "break -q B::func" command sets a breakpoint on
994 "B::func", only. A parameter has been added to the Python
995 gdb.Breakpoint constructor to achieve the same result when creating
996 a breakpoint from Python.
998 * Breakpoints on functions marked with C++ ABI tags
1000 GDB can now set breakpoints on functions marked with C++ ABI tags
1001 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1002 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1004 Functions with a C++11 abi tag are demangled/displayed like this:
1006 function[abi:cxx11](int)
1009 You can now set a breakpoint on such functions simply as if they had
1012 (gdb) b function(int)
1014 Or if you need to disambiguate between tags, like:
1016 (gdb) b function[abi:other_tag](int)
1018 Tab completion was adjusted accordingly as well.
1022 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1023 gdb.new_thread are emitted. See the manual for further
1024 description of these.
1026 ** A new function, "gdb.rbreak" has been added to the Python API.
1027 This function allows the setting of a large number of breakpoints
1028 via a regex pattern in Python. See the manual for further details.
1030 ** Python breakpoints can now accept explicit locations. See the
1031 manual for a further description of this feature.
1034 * New features in the GDB remote stub, GDBserver
1036 ** GDBserver is now able to start inferior processes with a
1037 specified initial working directory.
1039 The user can set the desired working directory to be used from
1040 GDB using the new "set cwd" command.
1042 ** New "--selftest" command line option runs some GDBserver self
1043 tests. These self tests are disabled in releases.
1045 ** On Unix systems, GDBserver now does globbing expansion and variable
1046 substitution in inferior command line arguments.
1048 This is done by starting inferiors using a shell, like GDB does.
1049 See "set startup-with-shell" in the user manual for how to disable
1050 this from GDB when using "target extended-remote". When using
1051 "target remote", you can disable the startup with shell by using the
1052 new "--no-startup-with-shell" GDBserver command line option.
1054 ** On Unix systems, GDBserver now supports receiving environment
1055 variables that are to be set or unset from GDB. These variables
1056 will affect the environment to be passed to the inferior.
1058 * When catching an Ada exception raised with a message, GDB now prints
1059 the message in the catchpoint hit notification. In GDB/MI mode, that
1060 information is provided as an extra field named "exception-message"
1061 in the *stopped notification.
1063 * Trait objects can now be inspected When debugging Rust code. This
1064 requires compiler support which will appear in Rust 1.24.
1066 * New remote packets
1068 QEnvironmentHexEncoded
1069 Inform GDBserver of an environment variable that is to be passed to
1070 the inferior when starting it.
1073 Inform GDBserver of an environment variable that is to be unset
1074 before starting the remote inferior.
1077 Inform GDBserver that the environment should be reset (i.e.,
1078 user-set environment variables should be unset).
1081 Indicates whether the inferior must be started with a shell or not.
1084 Tell GDBserver that the inferior to be started should use a specific
1087 * The "maintenance print c-tdesc" command now takes an optional
1088 argument which is the file name of XML target description.
1090 * The "maintenance selftest" command now takes an optional argument to
1091 filter the tests to be run.
1093 * The "enable", and "disable" commands now accept a range of
1094 breakpoint locations, e.g. "enable 1.3-5".
1099 Set and show the current working directory for the inferior.
1101 set|show compile-gcc
1102 Set and show compilation command used for compiling and injecting code
1103 with the 'compile' commands.
1105 set debug separate-debug-file
1106 show debug separate-debug-file
1107 Control the display of debug output about separate debug file search.
1109 set dump-excluded-mappings
1110 show dump-excluded-mappings
1111 Control whether mappings marked with the VM_DONTDUMP flag should be
1112 dumped when generating a core file.
1114 maint info selftests
1115 List the registered selftests.
1118 Start the debugged program stopping at the first instruction.
1121 Control display of debugging messages related to OpenRISC targets.
1123 set|show print type nested-type-limit
1124 Set and show the limit of nesting level for nested types that the
1125 type printer will show.
1127 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1130 * Safer/improved support for debugging with no debug info
1132 GDB no longer assumes functions with no debug information return
1135 This means that GDB now refuses to call such functions unless you
1136 tell it the function's type, by either casting the call to the
1137 declared return type, or by casting the function to a function
1138 pointer of the right type, and calling that:
1140 (gdb) p getenv ("PATH")
1141 'getenv' has unknown return type; cast the call to its declared return type
1142 (gdb) p (char *) getenv ("PATH")
1143 $1 = 0x7fffffffe "/usr/local/bin:/"...
1144 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1145 $2 = 0x7fffffffe "/usr/local/bin:/"...
1147 Similarly, GDB no longer assumes that global variables with no debug
1148 info have type 'int', and refuses to print the variable's value
1149 unless you tell it the variable's type:
1152 'var' has unknown type; cast it to its declared type
1156 * New native configurations
1158 FreeBSD/aarch64 aarch64*-*-freebsd*
1159 FreeBSD/arm arm*-*-freebsd*
1163 FreeBSD/aarch64 aarch64*-*-freebsd*
1164 FreeBSD/arm arm*-*-freebsd*
1165 OpenRISC ELF or1k*-*-elf
1167 * Removed targets and native configurations
1169 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1171 *** Changes in GDB 8.0
1173 * GDB now supports access to the PKU register on GNU/Linux. The register is
1174 added by the Memory Protection Keys for Userspace feature which will be
1175 available in future Intel CPUs.
1177 * GDB now supports C++11 rvalue references.
1181 ** New functions to start, stop and access a running btrace recording.
1182 ** Rvalue references are now supported in gdb.Type.
1184 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1187 * Building GDB and GDBserver now requires a C++11 compiler.
1189 For example, GCC 4.8 or later.
1191 It is no longer possible to build GDB or GDBserver with a C
1192 compiler. The --disable-build-with-cxx configure option has been
1195 * Building GDB and GDBserver now requires GNU make >= 3.81.
1197 It is no longer supported to build GDB or GDBserver with another
1198 implementation of the make program or an earlier version of GNU make.
1200 * Native debugging on MS-Windows supports command-line redirection
1202 Command-line arguments used for starting programs on MS-Windows can
1203 now include redirection symbols supported by native Windows shells,
1204 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1205 as "run", "start", and "set args", as well as the corresponding MI
1208 * Support for thread names on MS-Windows.
1210 GDB now catches and handles the special exception that programs
1211 running on MS-Windows use to assign names to threads in the
1214 * Support for Java programs compiled with gcj has been removed.
1216 * User commands now accept an unlimited number of arguments.
1217 Previously, only up to 10 was accepted.
1219 * The "eval" command now expands user-defined command arguments.
1221 This makes it easier to process a variable number of arguments:
1226 eval "print $arg%d", $i
1231 * Target descriptions can now describe registers for sparc32 and sparc64.
1233 * GDB now supports DWARF version 5 (debug information format).
1234 Its .debug_names index is not yet supported.
1236 * New native configurations
1238 FreeBSD/mips mips*-*-freebsd
1242 Synopsys ARC arc*-*-elf32
1243 FreeBSD/mips mips*-*-freebsd
1245 * Removed targets and native configurations
1247 Alpha running FreeBSD alpha*-*-freebsd*
1248 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1253 Erases all the flash memory regions reported by the target.
1255 maint print arc arc-instruction address
1256 Print internal disassembler information about instruction at a given address.
1260 set disassembler-options
1261 show disassembler-options
1262 Controls the passing of target specific information to the disassembler.
1263 If it is necessary to specify more than one disassembler option then
1264 multiple options can be placed together into a comma separated list.
1265 The default value is the empty string. Currently, the only supported
1266 targets are ARM, PowerPC and S/390.
1271 Erases all the flash memory regions reported by the target. This is
1272 equivalent to the CLI command flash-erase.
1274 -file-list-shared-libraries
1275 List the shared libraries in the program. This is
1276 equivalent to the CLI command "info shared".
1279 Catchpoints stopping the program when Ada exceptions are
1280 handled. This is equivalent to the CLI command "catch handlers".
1282 *** Changes in GDB 7.12
1284 * GDB and GDBserver now build with a C++ compiler by default.
1286 The --enable-build-with-cxx configure option is now enabled by
1287 default. One must now explicitly configure with
1288 --disable-build-with-cxx in order to build with a C compiler. This
1289 option will be removed in a future release.
1291 * GDBserver now supports recording btrace without maintaining an active
1294 * GDB now supports a negative repeat count in the 'x' command to examine
1295 memory backward from the given address. For example:
1298 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1299 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1300 (gdb) x/-5i 0x0000000000400580
1301 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1302 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1303 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1304 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1305 0x40057b <main(int, char**)+25>:
1306 callq 0x400536 <Func1(int, char const*)>
1308 * Fortran: Support structures with fields of dynamic types and
1309 arrays of dynamic types.
1311 * The symbol dumping maintenance commands have new syntax.
1312 maint print symbols [-pc address] [--] [filename]
1313 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1314 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1315 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1316 maint print msymbols [-objfile objfile] [--] [filename]
1318 * GDB now supports multibit bitfields and enums in target register
1321 * New Python-based convenience function $_as_string(val), which returns
1322 the textual representation of a value. This function is especially
1323 useful to obtain the text label of an enum value.
1325 * Intel MPX bound violation handling.
1327 Segmentation faults caused by a Intel MPX boundary violation
1328 now display the kind of violation (upper or lower), the memory
1329 address accessed and the memory bounds, along with the usual
1330 signal received and code location.
1334 Program received signal SIGSEGV, Segmentation fault
1335 Upper bound violation while accessing address 0x7fffffffc3b3
1336 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1337 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1339 * Rust language support.
1340 GDB now supports debugging programs written in the Rust programming
1341 language. See https://www.rust-lang.org/ for more information about
1344 * Support for running interpreters on specified input/output devices
1346 GDB now supports a new mechanism that allows frontends to provide
1347 fully featured GDB console views, as a better alternative to
1348 building such views on top of the "-interpreter-exec console"
1349 command. See the new "new-ui" command below. With that command,
1350 frontends can now start GDB in the traditional command-line mode
1351 running in an embedded terminal emulator widget, and create a
1352 separate MI interpreter running on a specified i/o device. In this
1353 way, GDB handles line editing, history, tab completion, etc. in the
1354 console all by itself, and the GUI uses the separate MI interpreter
1355 for its own control and synchronization, invisible to the command
1358 * The "catch syscall" command catches groups of related syscalls.
1360 The "catch syscall" command now supports catching a group of related
1361 syscalls using the 'group:' or 'g:' prefix.
1366 skip -gfile file-glob-pattern
1367 skip -function function
1368 skip -rfunction regular-expression
1369 A generalized form of the skip command, with new support for
1370 glob-style file names and regular expressions for function names.
1371 Additionally, a file spec and a function spec may now be combined.
1373 maint info line-table REGEXP
1374 Display the contents of GDB's internal line table data struture.
1377 Run any GDB unit tests that were compiled in.
1380 Start a new user interface instance running INTERP as interpreter,
1381 using the TTY file for input/output.
1385 ** gdb.Breakpoint objects have a new attribute "pending", which
1386 indicates whether the breakpoint is pending.
1387 ** Three new breakpoint-related events have been added:
1388 gdb.breakpoint_created, gdb.breakpoint_modified, and
1389 gdb.breakpoint_deleted.
1391 signal-event EVENTID
1392 Signal ("set") the given MS-Windows event object. This is used in
1393 conjunction with the Windows JIT debugging (AeDebug) support, where
1394 the OS suspends a crashing process until a debugger can attach to
1395 it. Resuming the crashing process, in order to debug it, is done by
1396 signalling an event.
1398 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1399 was added in GDBserver, including JIT compiling fast tracepoint's
1400 conditional expression bytecode into native code.
1402 * Support for various remote target protocols and ROM monitors has
1405 target m32rsdi Remote M32R debugging over SDI
1406 target mips MIPS remote debugging protocol
1407 target pmon PMON ROM monitor
1408 target ddb NEC's DDB variant of PMON for Vr4300
1409 target rockhopper NEC RockHopper variant of PMON
1410 target lsi LSI variant of PMO
1412 * Support for tracepoints and fast tracepoints on powerpc-linux,
1413 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1414 including JIT compiling fast tracepoint's conditional expression
1415 bytecode into native code.
1417 * MI async record =record-started now includes the method and format used for
1418 recording. For example:
1420 =record-started,thread-group="i1",method="btrace",format="bts"
1422 * MI async record =thread-selected now includes the frame field. For example:
1424 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1428 Andes NDS32 nds32*-*-elf
1430 *** Changes in GDB 7.11
1432 * GDB now supports debugging kernel-based threads on FreeBSD.
1434 * Per-inferior thread numbers
1436 Thread numbers are now per inferior instead of global. If you're
1437 debugging multiple inferiors, GDB displays thread IDs using a
1438 qualified INF_NUM.THR_NUM form. For example:
1442 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1443 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1444 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1445 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1447 As consequence, thread numbers as visible in the $_thread
1448 convenience variable and in Python's InferiorThread.num attribute
1449 are no longer unique between inferiors.
1451 GDB now maintains a second thread ID per thread, referred to as the
1452 global thread ID, which is the new equivalent of thread numbers in
1453 previous releases. See also $_gthread below.
1455 For backwards compatibility, MI's thread IDs always refer to global
1458 * Commands that accept thread IDs now accept the qualified
1459 INF_NUM.THR_NUM form as well. For example:
1462 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1465 * In commands that accept a list of thread IDs, you can now refer to
1466 all threads of an inferior using a star wildcard. GDB accepts
1467 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1468 refer to all threads of the current inferior. For example, "info
1471 * You can use "info threads -gid" to display the global thread ID of
1474 * The new convenience variable $_gthread holds the global number of
1477 * The new convenience variable $_inferior holds the number of the
1480 * GDB now displays the ID and name of the thread that hit a breakpoint
1481 or received a signal, if your program is multi-threaded. For
1484 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1485 Thread 1 "main" received signal SIGINT, Interrupt.
1487 * Record btrace now supports non-stop mode.
1489 * Support for tracepoints on aarch64-linux was added in GDBserver.
1491 * The 'record instruction-history' command now indicates speculative execution
1492 when using the Intel Processor Trace recording format.
1494 * GDB now allows users to specify explicit locations, bypassing
1495 the linespec parser. This feature is also available to GDB/MI
1498 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1499 GDB now is able to debug both AArch64 applications and ARM applications
1502 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1503 including JIT compiling fast tracepoint's conditional expression bytecode
1506 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1508 * "info threads", "info inferiors", "info display", "info checkpoints"
1509 and "maint info program-spaces" now list the corresponding items in
1510 ascending ID order, for consistency with all other "info" commands.
1512 * In Ada, the overloads selection menu has been enhanced to display the
1513 parameter types and the return types for the matching overloaded subprograms.
1517 maint set target-non-stop (on|off|auto)
1518 maint show target-non-stop
1519 Control whether GDB targets always operate in non-stop mode even if
1520 "set non-stop" is "off". The default is "auto", meaning non-stop
1521 mode is enabled if supported by the target.
1523 maint set bfd-sharing
1524 maint show bfd-sharing
1525 Control the reuse of bfd objects.
1528 show debug bfd-cache
1529 Control display of debugging info regarding bfd caching.
1533 Control display of debugging info regarding FreeBSD threads.
1535 set remote multiprocess-extensions-packet
1536 show remote multiprocess-extensions-packet
1537 Set/show the use of the remote protocol multiprocess extensions.
1539 set remote thread-events
1540 show remote thread-events
1541 Set/show the use of thread create/exit events.
1543 set ada print-signatures on|off
1544 show ada print-signatures"
1545 Control whether parameter types and return types are displayed in overloads
1546 selection menus. It is activaled (@code{on}) by default.
1550 Controls the maximum size of memory, in bytes, that GDB will
1551 allocate for value contents. Prevents incorrect programs from
1552 causing GDB to allocate overly large buffers. Default is 64k.
1554 * The "disassemble" command accepts a new modifier: /s.
1555 It prints mixed source+disassembly like /m with two differences:
1556 - disassembled instructions are now printed in program order, and
1557 - and source for all relevant files is now printed.
1558 The "/m" option is now considered deprecated: its "source-centric"
1559 output hasn't proved useful in practice.
1561 * The "record instruction-history" command accepts a new modifier: /s.
1562 It behaves exactly like /m and prints mixed source+disassembly.
1564 * The "set scheduler-locking" command supports a new mode "replay".
1565 It behaves like "off" in record mode and like "on" in replay mode.
1567 * Support for various ROM monitors has been removed:
1569 target dbug dBUG ROM monitor for Motorola ColdFire
1570 target picobug Motorola picobug monitor
1571 target dink32 DINK32 ROM monitor for PowerPC
1572 target m32r Renesas M32R/D ROM monitor
1573 target mon2000 mon2000 ROM monitor
1574 target ppcbug PPCBUG ROM monitor for PowerPC
1576 * Support for reading/writing memory and extracting values on architectures
1577 whose memory is addressable in units of any integral multiple of 8 bits.
1580 Allows to break when an Ada exception is handled.
1582 * New remote packets
1585 Indicates that an exec system call was executed.
1587 exec-events feature in qSupported
1588 The qSupported packet allows GDB to request support for exec
1589 events using the new 'gdbfeature' exec-event, and the qSupported
1590 response can contain the corresponding 'stubfeature'. Set and
1591 show commands can be used to display whether these features are enabled.
1594 Equivalent to interrupting with the ^C character, but works in
1597 thread created stop reason (T05 create:...)
1598 Indicates that the thread was just created and is stopped at entry.
1600 thread exit stop reply (w exitcode;tid)
1601 Indicates that the thread has terminated.
1604 Enables/disables thread create and exit event reporting. For
1605 example, this is used in non-stop mode when GDB stops a set of
1606 threads and synchronously waits for the their corresponding stop
1607 replies. Without exit events, if one of the threads exits, GDB
1608 would hang forever not knowing that it should no longer expect a
1609 stop for that same thread.
1612 Indicates that there are no resumed threads left in the target (all
1613 threads are stopped). The remote stub reports support for this stop
1614 reply to GDB's qSupported query.
1617 Enables/disables catching syscalls from the inferior process.
1618 The remote stub reports support for this packet to GDB's qSupported query.
1620 syscall_entry stop reason
1621 Indicates that a syscall was just called.
1623 syscall_return stop reason
1624 Indicates that a syscall just returned.
1626 * Extended-remote exec events
1628 ** GDB now has support for exec events on extended-remote Linux targets.
1629 For such targets with Linux kernels 2.5.46 and later, this enables
1630 follow-exec-mode and exec catchpoints.
1632 set remote exec-event-feature-packet
1633 show remote exec-event-feature-packet
1634 Set/show the use of the remote exec event feature.
1636 * Thread names in remote protocol
1638 The reply to qXfer:threads:read may now include a name attribute for each
1641 * Target remote mode fork and exec events
1643 ** GDB now has support for fork and exec events on target remote mode
1644 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1645 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1646 fork and exec catchpoints.
1648 * Remote syscall events
1650 ** GDB now has support for catch syscall on remote Linux targets,
1651 currently enabled on x86/x86_64 architectures.
1653 set remote catch-syscall-packet
1654 show remote catch-syscall-packet
1655 Set/show the use of the remote catch syscall feature.
1659 ** The -var-set-format command now accepts the zero-hexadecimal
1660 format. It outputs data in hexadecimal format with zero-padding on the
1665 ** gdb.InferiorThread objects have a new attribute "global_num",
1666 which refers to the thread's global thread ID. The existing
1667 "num" attribute now refers to the thread's per-inferior number.
1668 See "Per-inferior thread numbers" above.
1669 ** gdb.InferiorThread objects have a new attribute "inferior", which
1670 is the Inferior object the thread belongs to.
1672 *** Changes in GDB 7.10
1674 * Support for process record-replay and reverse debugging on aarch64*-linux*
1675 targets has been added. GDB now supports recording of A64 instruction set
1676 including advance SIMD instructions.
1678 * Support for Sun's version of the "stabs" debug file format has been removed.
1680 * GDB now honors the content of the file /proc/PID/coredump_filter
1681 (PID is the process ID) on GNU/Linux systems. This file can be used
1682 to specify the types of memory mappings that will be included in a
1683 corefile. For more information, please refer to the manual page of
1684 "core(5)". GDB also has a new command: "set use-coredump-filter
1685 on|off". It allows to set whether GDB will read the content of the
1686 /proc/PID/coredump_filter file when generating a corefile.
1688 * The "info os" command on GNU/Linux can now display information on
1690 "info os cpus" Listing of all cpus/cores on the system
1692 * GDB has two new commands: "set serial parity odd|even|none" and
1693 "show serial parity". These allows to set or show parity for the
1696 * The "info source" command now displays the producer string if it was
1697 present in the debug info. This typically includes the compiler version
1698 and may include things like its command line arguments.
1700 * The "info dll", an alias of the "info sharedlibrary" command,
1701 is now available on all platforms.
1703 * Directory names supplied to the "set sysroot" commands may be
1704 prefixed with "target:" to tell GDB to access shared libraries from
1705 the target system, be it local or remote. This replaces the prefix
1706 "remote:". The default sysroot has been changed from "" to
1707 "target:". "remote:" is automatically converted to "target:" for
1708 backward compatibility.
1710 * The system root specified by "set sysroot" will be prepended to the
1711 filename of the main executable (if reported to GDB as absolute by
1712 the operating system) when starting processes remotely, and when
1713 attaching to already-running local or remote processes.
1715 * GDB now supports automatic location and retrieval of executable
1716 files from remote targets. Remote debugging can now be initiated
1717 using only a "target remote" or "target extended-remote" command
1718 (no "set sysroot" or "file" commands are required). See "New remote
1721 * The "dump" command now supports verilog hex format.
1723 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1725 * On GNU/Linux, GDB and gdbserver are now able to access executable
1726 and shared library files without a "set sysroot" command when
1727 attaching to processes running in different mount namespaces from
1728 the debugger. This makes it possible to attach to processes in
1729 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1730 See "New remote packets" below.
1732 * The "tui reg" command now provides completion for all of the
1733 available register groups, including target specific groups.
1735 * The HISTSIZE environment variable is no longer read when determining
1736 the size of GDB's command history. GDB now instead reads the dedicated
1737 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1738 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1743 ** Memory ports can now be unbuffered.
1747 ** gdb.Objfile objects have a new attribute "username",
1748 which is the name of the objfile as specified by the user,
1749 without, for example, resolving symlinks.
1750 ** You can now write frame unwinders in Python.
1751 ** gdb.Type objects have a new method "optimized_out",
1752 returning optimized out gdb.Value instance of this type.
1753 ** gdb.Value objects have new methods "reference_value" and
1754 "const_value" which return a reference to the value and a
1755 "const" version of the value respectively.
1759 maint print symbol-cache
1760 Print the contents of the symbol cache.
1762 maint print symbol-cache-statistics
1763 Print statistics of symbol cache usage.
1765 maint flush-symbol-cache
1766 Flush the contents of the symbol cache.
1770 Start branch trace recording using Branch Trace Store (BTS) format.
1773 Evaluate expression by using the compiler and print result.
1777 Explicit commands for enabling and disabling tui mode.
1780 set mpx bound on i386 and amd64
1781 Support for bound table investigation on Intel MPX enabled applications.
1785 Start branch trace recording using Intel Processor Trace format.
1788 Print information about branch tracing internals.
1790 maint btrace packet-history
1791 Print the raw branch tracing data.
1793 maint btrace clear-packet-history
1794 Discard the stored raw branch tracing data.
1797 Discard all branch tracing data. It will be fetched and processed
1798 anew by the next "record" command.
1803 Renamed from "set debug dwarf2-die".
1804 show debug dwarf-die
1805 Renamed from "show debug dwarf2-die".
1807 set debug dwarf-read
1808 Renamed from "set debug dwarf2-read".
1809 show debug dwarf-read
1810 Renamed from "show debug dwarf2-read".
1812 maint set dwarf always-disassemble
1813 Renamed from "maint set dwarf2 always-disassemble".
1814 maint show dwarf always-disassemble
1815 Renamed from "maint show dwarf2 always-disassemble".
1817 maint set dwarf max-cache-age
1818 Renamed from "maint set dwarf2 max-cache-age".
1819 maint show dwarf max-cache-age
1820 Renamed from "maint show dwarf2 max-cache-age".
1822 set debug dwarf-line
1823 show debug dwarf-line
1824 Control display of debugging info regarding DWARF line processing.
1827 show max-completions
1828 Set the maximum number of candidates to be considered during
1829 completion. The default value is 200. This limit allows GDB
1830 to avoid generating large completion lists, the computation of
1831 which can cause the debugger to become temporarily unresponsive.
1833 set history remove-duplicates
1834 show history remove-duplicates
1835 Control the removal of duplicate history entries.
1837 maint set symbol-cache-size
1838 maint show symbol-cache-size
1839 Control the size of the symbol cache.
1841 set|show record btrace bts buffer-size
1842 Set and show the size of the ring buffer used for branch tracing in
1844 The obtained size may differ from the requested size. Use "info
1845 record" to see the obtained buffer size.
1847 set debug linux-namespaces
1848 show debug linux-namespaces
1849 Control display of debugging info regarding Linux namespaces.
1851 set|show record btrace pt buffer-size
1852 Set and show the size of the ring buffer used for branch tracing in
1853 Intel Processor Trace format.
1854 The obtained size may differ from the requested size. Use "info
1855 record" to see the obtained buffer size.
1857 maint set|show btrace pt skip-pad
1858 Set and show whether PAD packets are skipped when computing the
1861 * The command 'thread apply all' can now support new option '-ascending'
1862 to call its specified command for all threads in ascending order.
1864 * Python/Guile scripting
1866 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1867 special section named `.debug_gdb_scripts'.
1869 * New remote packets
1871 qXfer:btrace-conf:read
1872 Return the branch trace configuration for the current thread.
1874 Qbtrace-conf:bts:size
1875 Set the requested ring buffer size for branch tracing in BTS format.
1878 Enable Intel Procesor Trace-based branch tracing for the current
1879 process. The remote stub reports support for this packet to GDB's
1882 Qbtrace-conf:pt:size
1883 Set the requested ring buffer size for branch tracing in Intel Processor
1887 Indicates a memory breakpoint instruction was executed, irrespective
1888 of whether it was GDB that planted the breakpoint or the breakpoint
1889 is hardcoded in the program. This is required for correct non-stop
1893 Indicates the target stopped for a hardware breakpoint. This is
1894 required for correct non-stop mode operation.
1897 Return information about files on the remote system.
1899 qXfer:exec-file:read
1900 Return the full absolute name of the file that was executed to
1901 create a process running on the remote system.
1904 Select the filesystem on which vFile: operations with filename
1905 arguments will operate. This is required for GDB to be able to
1906 access files on remote targets where the remote stub does not
1907 share a common filesystem with the inferior(s).
1910 Indicates that a fork system call was executed.
1913 Indicates that a vfork system call was executed.
1915 vforkdone stop reason
1916 Indicates that a vfork child of the specified process has executed
1917 an exec or exit, allowing the vfork parent to resume execution.
1919 fork-events and vfork-events features in qSupported
1920 The qSupported packet allows GDB to request support for fork and
1921 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1922 and the qSupported response can contain the corresponding
1923 'stubfeatures'. Set and show commands can be used to display
1924 whether these features are enabled.
1926 * Extended-remote fork events
1928 ** GDB now has support for fork events on extended-remote Linux
1929 targets. For targets with Linux kernels 2.5.60 and later, this
1930 enables follow-fork-mode and detach-on-fork for both fork and
1931 vfork, as well as fork and vfork catchpoints.
1933 * The info record command now shows the recording format and the
1934 branch tracing configuration for the current thread when using
1935 the btrace record target.
1936 For the BTS format, it shows the ring buffer size.
1938 * GDB now has support for DTrace USDT (Userland Static Defined
1939 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1941 * GDB now supports access to vector registers on S/390 GNU/Linux
1944 * Removed command line options
1946 -xdb HP-UX XDB compatibility mode.
1948 * Removed targets and native configurations
1950 HP/PA running HP-UX hppa*-*-hpux*
1951 Itanium running HP-UX ia64-*-hpux*
1953 * New configure options
1956 This configure option allows the user to build GDB with support for
1957 Intel Processor Trace (default: auto). This requires libipt.
1959 --with-libipt-prefix=PATH
1960 Specify the path to the version of libipt that GDB should use.
1961 $PATH/include should contain the intel-pt.h header and
1962 $PATH/lib should contain the libipt.so library.
1964 *** Changes in GDB 7.9.1
1968 ** Xmethods can now specify a result type.
1970 *** Changes in GDB 7.9
1972 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1976 ** You can now access frame registers from Python scripts.
1977 ** New attribute 'producer' for gdb.Symtab objects.
1978 ** gdb.Objfile objects have a new attribute "progspace",
1979 which is the gdb.Progspace object of the containing program space.
1980 ** gdb.Objfile objects have a new attribute "owner".
1981 ** gdb.Objfile objects have a new attribute "build_id",
1982 which is the build ID generated when the file was built.
1983 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1984 ** A new event "gdb.clear_objfiles" has been added, triggered when
1985 selecting a new file to debug.
1986 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1987 ** New function gdb.lookup_objfile.
1989 New events which are triggered when GDB modifies the state of the
1992 ** gdb.events.inferior_call_pre: Function call is about to be made.
1993 ** gdb.events.inferior_call_post: Function call has just been made.
1994 ** gdb.events.memory_changed: A memory location has been altered.
1995 ** gdb.events.register_changed: A register has been altered.
1997 * New Python-based convenience functions:
1999 ** $_caller_is(name [, number_of_frames])
2000 ** $_caller_matches(regexp [, number_of_frames])
2001 ** $_any_caller_is(name [, number_of_frames])
2002 ** $_any_caller_matches(regexp [, number_of_frames])
2004 * GDB now supports the compilation and injection of source code into
2005 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2006 to compile the source code to object code, and if successful, inject
2007 and execute that code within the current context of the inferior.
2008 Currently the C language is supported. The commands used to
2009 interface with this new feature are:
2011 compile code [-raw|-r] [--] [source code]
2012 compile file [-raw|-r] filename
2016 demangle [-l language] [--] name
2017 Demangle "name" in the specified language, or the current language
2018 if elided. This command is renamed from the "maint demangle" command.
2019 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2020 as "maint demangler-warning".
2022 queue-signal signal-name-or-number
2023 Queue a signal to be delivered to the thread when it is resumed.
2025 add-auto-load-scripts-directory directory
2026 Add entries to the list of directories from which to load auto-loaded
2029 maint print user-registers
2030 List all currently available "user" registers.
2032 compile code [-r|-raw] [--] [source code]
2033 Compile, inject, and execute in the inferior the executable object
2034 code produced by compiling the provided source code.
2036 compile file [-r|-raw] filename
2037 Compile and inject into the inferior the executable object code
2038 produced by compiling the source code stored in the filename
2041 * On resume, GDB now always passes the signal the program had stopped
2042 for to the thread the signal was sent to, even if the user changed
2043 threads before resuming. Previously GDB would often (but not
2044 always) deliver the signal to the thread that happens to be current
2047 * Conversely, the "signal" command now consistently delivers the
2048 requested signal to the current thread. GDB now asks for
2049 confirmation if the program had stopped for a signal and the user
2050 switched threads meanwhile.
2052 * "breakpoint always-inserted" modes "off" and "auto" merged.
2054 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2055 won't remove breakpoints from the target until all threads stop,
2056 even in non-stop mode. The "auto" mode has been removed, and "off"
2057 is now the default mode.
2061 set debug symbol-lookup
2062 show debug symbol-lookup
2063 Control display of debugging info regarding symbol lookup.
2067 ** The -list-thread-groups command outputs an exit-code field for
2068 inferiors that have exited.
2072 MIPS SDE mips*-sde*-elf*
2076 Support for these obsolete configurations has been removed.
2078 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2079 SGI Irix-5.x mips-*-irix5*
2080 SGI Irix-6.x mips-*-irix6*
2081 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2082 VAX running Ultrix vax-*-ultrix*
2084 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2085 and "assf"), have been removed. Use the "sharedlibrary" command, or
2086 its alias "share", instead.
2088 *** Changes in GDB 7.8
2090 * New command line options
2093 This is an alias for the --data-directory option.
2095 * GDB supports printing and modifying of variable length automatic arrays
2096 as specified in ISO C99.
2098 * The ARM simulator now supports instruction level tracing
2099 with or without disassembly.
2103 GDB now has support for scripting using Guile. Whether this is
2104 available is determined at configure time.
2105 Guile version 2.0 or greater is required.
2106 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2108 * New commands (for set/show, see "New options" below)
2112 Invoke CODE by passing it to the Guile interpreter.
2116 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2118 info auto-load guile-scripts [regexp]
2119 Print the list of automatically loaded Guile scripts.
2121 * The source command is now capable of sourcing Guile scripts.
2122 This feature is dependent on the debugger being built with Guile support.
2126 set print symbol-loading (off|brief|full)
2127 show print symbol-loading
2128 Control whether to print informational messages when loading symbol
2129 information for a file. The default is "full", but when debugging
2130 programs with large numbers of shared libraries the amount of output
2131 becomes less useful.
2133 set guile print-stack (none|message|full)
2134 show guile print-stack
2135 Show a stack trace when an error is encountered in a Guile script.
2137 set auto-load guile-scripts (on|off)
2138 show auto-load guile-scripts
2139 Control auto-loading of Guile script files.
2141 maint ada set ignore-descriptive-types (on|off)
2142 maint ada show ignore-descriptive-types
2143 Control whether the debugger should ignore descriptive types in Ada
2144 programs. The default is not to ignore the descriptive types. See
2145 the user manual for more details on descriptive types and the intended
2146 usage of this option.
2148 set auto-connect-native-target
2150 Control whether GDB is allowed to automatically connect to the
2151 native target for the run, attach, etc. commands when not connected
2152 to any target yet. See also "target native" below.
2154 set record btrace replay-memory-access (read-only|read-write)
2155 show record btrace replay-memory-access
2156 Control what memory accesses are allowed during replay.
2158 maint set target-async (on|off)
2159 maint show target-async
2160 This controls whether GDB targets operate in synchronous or
2161 asynchronous mode. Normally the default is asynchronous, if it is
2162 available; but this can be changed to more easily debug problems
2163 occurring only in synchronous mode.
2165 set mi-async (on|off)
2167 Control whether MI asynchronous mode is preferred. This supersedes
2168 "set target-async" of previous GDB versions.
2170 * "set target-async" is deprecated as a CLI option and is now an alias
2171 for "set mi-async" (only puts MI into async mode).
2173 * Background execution commands (e.g., "c&", "s&", etc.) are now
2174 possible ``out of the box'' if the target supports them. Previously
2175 the user would need to explicitly enable the possibility with the
2176 "set target-async on" command.
2178 * New features in the GDB remote stub, GDBserver
2180 ** New option --debug-format=option1[,option2,...] allows one to add
2181 additional text to each output. At present only timestamps
2182 are supported: --debug-format=timestamps.
2183 Timestamps can also be turned on with the
2184 "monitor set debug-format timestamps" command from GDB.
2186 * The 'record instruction-history' command now starts counting instructions
2187 at one. This also affects the instruction ranges reported by the
2188 'record function-call-history' command when given the /i modifier.
2190 * The command 'record function-call-history' supports a new modifier '/c' to
2191 indent the function names based on their call stack depth.
2192 The fields for the '/i' and '/l' modifier have been reordered.
2193 The source line range is now prefixed with 'at'.
2194 The instruction range is now prefixed with 'inst'.
2195 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2196 "record instruction-history" and "list" commands.
2198 * The ranges given as arguments to the 'record function-call-history' and
2199 'record instruction-history' commands are now inclusive.
2201 * The btrace record target now supports the 'record goto' command.
2202 For locations inside the execution trace, the back trace is computed
2203 based on the information stored in the execution trace.
2205 * The btrace record target supports limited reverse execution and replay.
2206 The target does not record data and therefore does not allow reading
2207 memory or registers.
2209 * The "catch syscall" command now works on s390*-linux* targets.
2211 * The "compare-sections" command is no longer specific to target
2212 remote. It now works with all targets.
2214 * All native targets are now consistently called "native".
2215 Consequently, the "target child", "target GNU", "target djgpp",
2216 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2217 commands have been replaced with "target native". The QNX/NTO port
2218 leaves the "procfs" target in place and adds a "native" target for
2219 consistency with other ports. The impact on users should be minimal
2220 as these commands previously either throwed an error, or were
2221 no-ops. The target's name is visible in the output of the following
2222 commands: "help target", "info target", "info files", "maint print
2225 * The "target native" command now connects to the native target. This
2226 can be used to launch native programs even when "set
2227 auto-connect-native-target" is set to off.
2229 * GDB now supports access to Intel MPX registers on GNU/Linux.
2231 * Support for Intel AVX-512 registers on GNU/Linux.
2232 Support displaying and modifying Intel AVX-512 registers
2233 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2235 * New remote packets
2237 qXfer:btrace:read's annex
2238 The qXfer:btrace:read packet supports a new annex 'delta' to read
2239 branch trace incrementally.
2243 ** Valid Python operations on gdb.Value objects representing
2244 structs/classes invoke the corresponding overloaded operators if
2246 ** New `Xmethods' feature in the Python API. Xmethods are
2247 additional methods or replacements for existing methods of a C++
2248 class. This feature is useful for those cases where a method
2249 defined in C++ source code could be inlined or optimized out by
2250 the compiler, making it unavailable to GDB.
2253 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2255 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2256 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2257 its alias "share", instead.
2259 * The commands "set remotebaud" and "show remotebaud" are no longer
2260 supported. Use "set serial baud" and "show serial baud" (respectively)
2265 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2266 target-async". The latter is left as a deprecated alias of the
2267 former for backward compatibility. If the target supports it,
2268 CLI background execution commands are now always possible by
2269 default, independently of whether the frontend stated a
2270 preference for asynchronous execution with "-gdb-set mi-async".
2271 Previously "-gdb-set target-async off" affected both MI execution
2272 commands and CLI execution commands.
2274 *** Changes in GDB 7.7
2276 * Improved support for process record-replay and reverse debugging on
2277 arm*-linux* targets. Support for thumb32 and syscall instruction
2278 recording has been added.
2280 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2282 * GDB now supports Fission DWP file format version 2.
2283 http://gcc.gnu.org/wiki/DebugFission
2285 * New convenience function "$_isvoid", to check whether an expression
2286 is void. A void expression is an expression where the type of the
2287 result is "void". For example, some convenience variables may be
2288 "void" when evaluated (e.g., "$_exitcode" before the execution of
2289 the program being debugged; or an undefined convenience variable).
2290 Another example, when calling a function whose return type is
2293 * The "maintenance print objfiles" command now takes an optional regexp.
2295 * The "catch syscall" command now works on arm*-linux* targets.
2297 * GDB now consistently shows "<not saved>" when printing values of
2298 registers the debug info indicates have not been saved in the frame
2299 and there's nowhere to retrieve them from
2300 (callee-saved/call-clobbered registers):
2305 (gdb) info registers rax
2308 Before, the former would print "<optimized out>", and the latter
2309 "*value not available*".
2311 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2316 ** Frame filters and frame decorators have been added.
2317 ** Temporary breakpoints are now supported.
2318 ** Line tables representation has been added.
2319 ** New attribute 'parent_type' for gdb.Field objects.
2320 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2321 ** New attribute 'name' for gdb.Type objects.
2325 Nios II ELF nios2*-*-elf
2326 Nios II GNU/Linux nios2*-*-linux
2327 Texas Instruments MSP430 msp430*-*-elf
2329 * Removed native configurations
2331 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2332 been removed. ELF variants of these configurations are kept supported.
2334 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2335 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2336 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2337 i[34567]86-*-openbsd3.[0-3]
2338 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2339 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2340 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2344 Like "catch throw", but catches a re-thrown exception.
2345 maint check-psymtabs
2346 Renamed from old "maint check-symtabs".
2348 Perform consistency checks on symtabs.
2349 maint expand-symtabs
2350 Expand symtabs matching an optional regexp.
2353 Display the details of GDB configure-time options.
2355 maint set|show per-command
2356 maint set|show per-command space
2357 maint set|show per-command time
2358 maint set|show per-command symtab
2359 Enable display of per-command gdb resource usage.
2361 remove-symbol-file FILENAME
2362 remove-symbol-file -a ADDRESS
2363 Remove a symbol file added via add-symbol-file. The file to remove
2364 can be identified by its filename or by an address that lies within
2365 the boundaries of this symbol file in memory.
2368 info exceptions REGEXP
2369 Display the list of Ada exceptions defined in the program being
2370 debugged. If provided, only the exceptions whose names match REGEXP
2375 set debug symfile off|on
2377 Control display of debugging info regarding reading symbol files and
2378 symbol tables within those files
2380 set print raw frame-arguments
2381 show print raw frame-arguments
2382 Set/show whether to print frame arguments in raw mode,
2383 disregarding any defined pretty-printers.
2385 set remote trace-status-packet
2386 show remote trace-status-packet
2387 Set/show the use of remote protocol qTStatus packet.
2391 Control display of debugging messages related to Nios II targets.
2395 Control whether target-assisted range stepping is enabled.
2397 set startup-with-shell
2398 show startup-with-shell
2399 Specifies whether Unix child processes are started via a shell or
2404 Use the target memory cache for accesses to the code segment. This
2405 improves performance of remote debugging (particularly disassembly).
2407 * You can now use a literal value 'unlimited' for options that
2408 interpret 0 or -1 as meaning "unlimited". E.g., "set
2409 trace-buffer-size unlimited" is now an alias for "set
2410 trace-buffer-size -1" and "set height unlimited" is now an alias for
2413 * The "set debug symtab-create" debugging option of GDB has been changed to
2414 accept a verbosity level. 0 means "off", 1 provides basic debugging
2415 output, and values of 2 or greater provides more verbose output.
2417 * New command-line options
2419 Display the details of GDB configure-time options.
2421 * The command 'tsave' can now support new option '-ctf' to save trace
2422 buffer in Common Trace Format.
2424 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2427 * GDB now implements the C++ 'typeid' operator.
2429 * The new convenience variable $_exception holds the exception being
2430 thrown or caught at an exception-related catchpoint.
2432 * The exception-related catchpoints, like "catch throw", now accept a
2433 regular expression which can be used to filter exceptions by type.
2435 * The new convenience variable $_exitsignal is automatically set to
2436 the terminating signal number when the program being debugged dies
2437 due to an uncaught signal.
2441 ** All MI commands now accept an optional "--language" option.
2442 Support for this feature can be verified by using the "-list-features"
2443 command, which should contain "language-option".
2445 ** The new command -info-gdb-mi-command allows the user to determine
2446 whether a GDB/MI command is supported or not.
2448 ** The "^error" result record returned when trying to execute an undefined
2449 GDB/MI command now provides a variable named "code" whose content is the
2450 "undefined-command" error code. Support for this feature can be verified
2451 by using the "-list-features" command, which should contain
2452 "undefined-command-error-code".
2454 ** The -trace-save MI command can optionally save trace buffer in Common
2457 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2459 ** The command -data-list-register-values now accepts an optional
2460 "--skip-unavailable" option. When used, only the available registers
2463 ** The new command -trace-frame-collected dumps collected variables,
2464 computed expressions, tvars, memory and registers in a traceframe.
2466 ** The commands -stack-list-locals, -stack-list-arguments and
2467 -stack-list-variables now accept an option "--skip-unavailable".
2468 When used, only the available locals or arguments are displayed.
2470 ** The -exec-run command now accepts an optional "--start" option.
2471 When used, the command follows the same semantics as the "start"
2472 command, stopping the program's execution at the start of its
2473 main subprogram. Support for this feature can be verified using
2474 the "-list-features" command, which should contain
2475 "exec-run-start-option".
2477 ** The new commands -catch-assert and -catch-exceptions insert
2478 catchpoints stopping the program when Ada exceptions are raised.
2480 ** The new command -info-ada-exceptions provides the equivalent of
2481 the new "info exceptions" command.
2483 * New system-wide configuration scripts
2484 A GDB installation now provides scripts suitable for use as system-wide
2485 configuration scripts for the following systems:
2489 * GDB now supports target-assigned range stepping with remote targets.
2490 This improves the performance of stepping source lines by reducing
2491 the number of control packets from/to GDB. See "New remote packets"
2494 * GDB now understands the element 'tvar' in the XML traceframe info.
2495 It has the id of the collected trace state variables.
2497 * On S/390 targets that provide the transactional-execution feature,
2498 the program interruption transaction diagnostic block (TDB) is now
2499 represented as a number of additional "registers" in GDB.
2501 * New remote packets
2505 The vCont packet supports a new 'r' action, that tells the remote
2506 stub to step through an address range itself, without GDB
2507 involvemement at each single-step.
2509 qXfer:libraries-svr4:read's annex
2510 The previously unused annex of the qXfer:libraries-svr4:read packet
2511 is now used to support passing an argument list. The remote stub
2512 reports support for this argument list to GDB's qSupported query.
2513 The defined arguments are "start" and "prev", used to reduce work
2514 necessary for library list updating, resulting in significant
2517 * New features in the GDB remote stub, GDBserver
2519 ** GDBserver now supports target-assisted range stepping. Currently
2520 enabled on x86/x86_64 GNU/Linux targets.
2522 ** GDBserver now adds element 'tvar' in the XML in the reply to
2523 'qXfer:traceframe-info:read'. It has the id of the collected
2524 trace state variables.
2526 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2529 * New 'z' formatter for printing and examining memory, this displays the
2530 value as hexadecimal zero padded on the left to the size of the type.
2532 * GDB can now use Windows x64 unwinding data.
2534 * The "set remotebaud" command has been replaced by "set serial baud".
2535 Similarly, "show remotebaud" has been replaced by "show serial baud".
2536 The "set remotebaud" and "show remotebaud" commands are still available
2537 to provide backward compatibility with older versions of GDB.
2539 *** Changes in GDB 7.6
2541 * Target record has been renamed to record-full.
2542 Record/replay is now enabled with the "record full" command.
2543 This also affects settings that are associated with full record/replay
2544 that have been moved from "set/show record" to "set/show record full":
2546 set|show record full insn-number-max
2547 set|show record full stop-at-limit
2548 set|show record full memory-query
2550 * A new record target "record-btrace" has been added. The new target
2551 uses hardware support to record the control-flow of a process. It
2552 does not support replaying the execution, but it implements the
2553 below new commands for investigating the recorded execution log.
2554 This new recording method can be enabled using:
2558 The "record-btrace" target is only available on Intel Atom processors
2559 and requires a Linux kernel 2.6.32 or later.
2561 * Two new commands have been added for record/replay to give information
2562 about the recorded execution without having to replay the execution.
2563 The commands are only supported by "record btrace".
2565 record instruction-history prints the execution history at
2566 instruction granularity
2568 record function-call-history prints the execution history at
2569 function granularity
2571 * New native configurations
2573 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2574 FreeBSD/powerpc powerpc*-*-freebsd
2575 x86_64/Cygwin x86_64-*-cygwin*
2576 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2580 ARM AArch64 aarch64*-*-elf
2581 ARM AArch64 GNU/Linux aarch64*-*-linux
2582 Lynx 178 PowerPC powerpc-*-lynx*178
2583 x86_64/Cygwin x86_64-*-cygwin*
2584 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2586 * If the configured location of system.gdbinit file (as given by the
2587 --with-system-gdbinit option at configure time) is in the
2588 data-directory (as specified by --with-gdb-datadir at configure
2589 time) or in one of its subdirectories, then GDB will look for the
2590 system-wide init file in the directory specified by the
2591 --data-directory command-line option.
2593 * New command line options:
2595 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2596 other initialization files, unlike -nx which disables all of them.
2598 * Removed command line options
2600 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2603 * The 'ptype' and 'whatis' commands now accept an argument to control
2606 * 'info proc' now works on some core files.
2610 ** Vectors can be created with gdb.Type.vector.
2612 ** Python's atexit.register now works in GDB.
2614 ** Types can be pretty-printed via a Python API.
2616 ** Python 3 is now supported (in addition to Python 2.4 or later)
2618 ** New class gdb.Architecture exposes GDB's internal representation
2619 of architecture in the Python API.
2621 ** New method Frame.architecture returns the gdb.Architecture object
2622 corresponding to the frame's architecture.
2624 * New Python-based convenience functions:
2626 ** $_memeq(buf1, buf2, length)
2627 ** $_streq(str1, str2)
2629 ** $_regex(str, regex)
2631 * The 'cd' command now defaults to using '~' (the home directory) if not
2634 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2635 default for GCC since November 2000.
2637 * The command 'forward-search' can now be abbreviated as 'fo'.
2639 * The command 'info tracepoints' can now display 'installed on target'
2640 or 'not installed on target' for each non-pending location of tracepoint.
2642 * New configure options
2644 --enable-libmcheck/--disable-libmcheck
2645 By default, development versions are built with -lmcheck on hosts
2646 that support it, in order to help track memory corruption issues.
2647 Release versions, on the other hand, are built without -lmcheck
2648 by default. The --enable-libmcheck/--disable-libmcheck configure
2649 options allow the user to override that default.
2650 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2651 This configure option allows the user to build GDB with
2652 libbabeltrace using which GDB can read Common Trace Format data.
2654 * New commands (for set/show, see "New options" below)
2657 Catch signals. This is similar to "handle", but allows commands and
2658 conditions to be attached.
2661 List the BFDs known to GDB.
2663 python-interactive [command]
2665 Start a Python interactive prompt, or evaluate the optional command
2666 and print the result of expressions.
2669 "py" is a new alias for "python".
2671 enable type-printer [name]...
2672 disable type-printer [name]...
2673 Enable or disable type printers.
2677 ** For the Renesas Super-H architecture, the "regs" command has been removed
2678 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2683 set print type methods (on|off)
2684 show print type methods
2685 Control whether method declarations are displayed by "ptype".
2686 The default is to show them.
2688 set print type typedefs (on|off)
2689 show print type typedefs
2690 Control whether typedef definitions are displayed by "ptype".
2691 The default is to show them.
2693 set filename-display basename|relative|absolute
2694 show filename-display
2695 Control the way in which filenames is displayed.
2696 The default is "relative", which preserves previous behavior.
2698 set trace-buffer-size
2699 show trace-buffer-size
2700 Request target to change the size of trace buffer.
2702 set remote trace-buffer-size-packet auto|on|off
2703 show remote trace-buffer-size-packet
2704 Control the use of the remote protocol `QTBuffer:size' packet.
2708 Control display of debugging messages related to ARM AArch64.
2711 set debug coff-pe-read
2712 show debug coff-pe-read
2713 Control display of debugging messages related to reading of COFF/PE
2718 Control display of debugging messages related to Mach-O symbols
2721 set debug notification
2722 show debug notification
2723 Control display of debugging info for async remote notification.
2727 ** Command parameter changes are now notified using new async record
2728 "=cmd-param-changed".
2729 ** Trace frame changes caused by command "tfind" are now notified using
2730 new async record "=traceframe-changed".
2731 ** The creation, deletion and modification of trace state variables
2732 are now notified using new async records "=tsv-created",
2733 "=tsv-deleted" and "=tsv-modified".
2734 ** The start and stop of process record are now notified using new
2735 async record "=record-started" and "=record-stopped".
2736 ** Memory changes are now notified using new async record
2738 ** The data-disassemble command response will include a "fullname" field
2739 containing the absolute file name when source has been requested.
2740 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2741 command, to allow pattern filling of memory areas.
2742 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2743 library load/unload events.
2744 ** The response to breakpoint commands and breakpoint async records
2745 includes an "installed" field containing a boolean state about each
2746 non-pending tracepoint location is whether installed on target or not.
2747 ** Output of the "-trace-status" command includes a "trace-file" field
2748 containing the name of the trace file being examined. This field is
2749 optional, and only present when examining a trace file.
2750 ** The "fullname" field is now always present along with the "file" field,
2751 even if the file cannot be found by GDB.
2753 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2754 You must have the LZMA library available when configuring GDB for this
2755 feature to be enabled. For more information, see:
2756 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2758 * New remote packets
2761 Set the size of trace buffer. The remote stub reports support for this
2762 packet to gdb's qSupported query.
2765 Enable Branch Trace Store (BTS)-based branch tracing for the current
2766 thread. The remote stub reports support for this packet to gdb's
2770 Disable branch tracing for the current thread. The remote stub reports
2771 support for this packet to gdb's qSupported query.
2774 Read the traced branches for the current thread. The remote stub
2775 reports support for this packet to gdb's qSupported query.
2777 *** Changes in GDB 7.5
2779 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2780 for more x32 ABI info.
2782 * GDB now supports access to MIPS DSP registers on Linux targets.
2784 * GDB now supports debugging microMIPS binaries.
2786 * The "info os" command on GNU/Linux can now display information on
2787 several new classes of objects managed by the operating system:
2788 "info os procgroups" lists process groups
2789 "info os files" lists file descriptors
2790 "info os sockets" lists internet-domain sockets
2791 "info os shm" lists shared-memory regions
2792 "info os semaphores" lists semaphores
2793 "info os msg" lists message queues
2794 "info os modules" lists loaded kernel modules
2796 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2797 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2798 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2799 options and inspect the probe arguments using the new $_probe_arg family
2800 of convenience variables. You can obtain more information about SystemTap
2801 in <http://sourceware.org/systemtap/>.
2803 * GDB now supports reversible debugging on ARM, it allows you to
2804 debug basic ARM and THUMB instructions, and provides
2805 record/replay support.
2807 * The option "symbol-reloading" has been deleted as it is no longer used.
2811 ** GDB commands implemented in Python can now be put in command class
2814 ** The "maint set python print-stack on|off" is now deleted.
2816 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2817 apply "flag enum"-style pretty-printing to any enum.
2819 ** gdb.lookup_symbol can now work when there is no current frame.
2821 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2822 the source at which the symbol was defined.
2824 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2825 method 'value'. The former indicates whether the symbol needs a
2826 frame in order to compute its value, and the latter computes the
2829 ** A new method 'referenced_value' on gdb.Value objects which can
2830 dereference pointer as well as C++ reference values.
2832 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2833 which return the global and static blocks (as gdb.Block objects),
2834 of the underlying symbol table, respectively.
2836 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2837 object associated with a PC value.
2839 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2840 of the address range occupied by code for the current source line.
2842 * Go language support.
2843 GDB now supports debugging programs written in the Go programming
2846 * GDBserver now supports stdio connections.
2847 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2849 * The binary "gdbtui" can no longer be built or installed.
2850 Use "gdb -tui" instead.
2852 * GDB will now print "flag" enums specially. A flag enum is one where
2853 all the enumerator values have no bits in common when pairwise
2854 "and"ed. When printing a value whose type is a flag enum, GDB will
2855 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2856 (gdb) print (enum E) 3
2859 * The filename part of a linespec will now match trailing components
2860 of a source file name. For example, "break gcc/expr.c:1000" will
2861 now set a breakpoint in build/gcc/expr.c, but not
2862 build/libcpp/expr.c.
2864 * The "info proc" and "generate-core-file" commands will now also
2865 work on remote targets connected to GDBserver on Linux.
2867 * The command "info catch" has been removed. It has been disabled
2868 since December 2007.
2870 * The "catch exception" and "catch assert" commands now accept
2871 a condition at the end of the command, much like the "break"
2872 command does. For instance:
2874 (gdb) catch exception Constraint_Error if Barrier = True
2876 Previously, it was possible to add a condition to such catchpoints,
2877 but it had to be done as a second step, after the catchpoint had been
2878 created, using the "condition" command.
2880 * The "info static-tracepoint-marker" command will now also work on
2881 native Linux targets with in-process agent.
2883 * GDB can now set breakpoints on inlined functions.
2885 * The .gdb_index section has been updated to include symbols for
2886 inlined functions. GDB will ignore older .gdb_index sections by
2887 default, which could cause symbol files to be loaded more slowly
2888 until their .gdb_index sections can be recreated. The new command
2889 "set use-deprecated-index-sections on" will cause GDB to use any older
2890 .gdb_index sections it finds. This will restore performance, but the
2891 ability to set breakpoints on inlined functions will be lost in symbol
2892 files with older .gdb_index sections.
2894 The .gdb_index section has also been updated to record more information
2895 about each symbol. This speeds up the "info variables", "info functions"
2896 and "info types" commands when used with programs having the .gdb_index
2897 section, as well as speeding up debugging with shared libraries using
2898 the .gdb_index section.
2900 * Ada support for GDB/MI Variable Objects has been added.
2902 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2907 ** New command -info-os is the MI equivalent of "info os".
2909 ** Output logs ("set logging" and related) now include MI output.
2913 ** "set use-deprecated-index-sections on|off"
2914 "show use-deprecated-index-sections on|off"
2915 Controls the use of deprecated .gdb_index sections.
2917 ** "catch load" and "catch unload" can be used to stop when a shared
2918 library is loaded or unloaded, respectively.
2920 ** "enable count" can be used to auto-disable a breakpoint after
2923 ** "info vtbl" can be used to show the virtual method tables for
2924 C++ and Java objects.
2926 ** "explore" and its sub commands "explore value" and "explore type"
2927 can be used to recursively explore values and types of
2928 expressions. These commands are available only if GDB is
2929 configured with '--with-python'.
2931 ** "info auto-load" shows status of all kinds of auto-loaded files,
2932 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2933 sequences of commands files, "info auto-load python-scripts"
2934 shows status of auto-loading Python script files,
2935 "info auto-load local-gdbinit" shows status of loading init file
2936 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2937 status of inferior specific thread debugging shared library loading.
2939 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2940 and "show auto-load-scripts" commands have been deprecated, use their
2941 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2942 and "show auto-load python-scripts" counterparts instead.
2944 ** "dprintf location,format,args..." creates a dynamic printf, which
2945 is basically a breakpoint that does a printf and immediately
2946 resumes your program's execution, so it is like a printf that you
2947 can insert dynamically at runtime instead of at compiletime.
2949 ** "set print symbol"
2951 Controls whether GDB attempts to display the symbol, if any,
2952 corresponding to addresses it prints. This defaults to "on", but
2953 you can set it to "off" to restore GDB's previous behavior.
2955 * Deprecated commands
2957 ** For the Renesas Super-H architecture, the "regs" command has been
2958 deprecated, and "info all-registers" should be used instead.
2962 Renesas RL78 rl78-*-elf
2963 HP OpenVMS ia64 ia64-hp-openvms*
2965 * GDBserver supports evaluation of breakpoint conditions. When
2966 support is advertised by GDBserver, GDB may be told to send the
2967 breakpoint conditions in bytecode form to GDBserver. GDBserver
2968 will only report the breakpoint trigger to GDB when its condition
2973 set mips compression
2974 show mips compression
2975 Select the compressed ISA encoding used in functions that have no symbol
2976 information available. The encoding can be set to either of:
2979 and is updated automatically from ELF file flags if available.
2981 set breakpoint condition-evaluation
2982 show breakpoint condition-evaluation
2983 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2984 GDBserver ("target"). Default option "auto" chooses the most efficient
2986 This option can improve debugger efficiency depending on the speed of the
2990 Disable auto-loading globally.
2993 Show auto-loading setting of all kinds of auto-loaded files.
2995 set auto-load gdb-scripts on|off
2996 show auto-load gdb-scripts
2997 Control auto-loading of GDB canned sequences of commands files.
2999 set auto-load python-scripts on|off
3000 show auto-load python-scripts
3001 Control auto-loading of Python script files.
3003 set auto-load local-gdbinit on|off
3004 show auto-load local-gdbinit
3005 Control loading of init file (.gdbinit) from current directory.
3007 set auto-load libthread-db on|off
3008 show auto-load libthread-db
3009 Control auto-loading of inferior specific thread debugging shared library.
3011 set auto-load scripts-directory <dir1>[:<dir2>...]
3012 show auto-load scripts-directory
3013 Set a list of directories from which to load auto-loaded scripts.
3014 Automatically loaded Python scripts and GDB scripts are located in one
3015 of the directories listed by this option.
3016 The delimiter (':' above) may differ according to the host platform.
3018 set auto-load safe-path <dir1>[:<dir2>...]
3019 show auto-load safe-path
3020 Set a list of directories from which it is safe to auto-load files.
3021 The delimiter (':' above) may differ according to the host platform.
3023 set debug auto-load on|off
3024 show debug auto-load
3025 Control display of debugging info for auto-loading the files above.
3027 set dprintf-style gdb|call|agent
3029 Control the way in which a dynamic printf is performed; "gdb"
3030 requests a GDB printf command, while "call" causes dprintf to call a
3031 function in the inferior. "agent" requests that the target agent
3032 (such as GDBserver) do the printing.
3034 set dprintf-function <expr>
3035 show dprintf-function
3036 set dprintf-channel <expr>
3037 show dprintf-channel
3038 Set the function and optional first argument to the call when using
3039 the "call" style of dynamic printf.
3041 set disconnected-dprintf on|off
3042 show disconnected-dprintf
3043 Control whether agent-style dynamic printfs continue to be in effect
3044 after GDB disconnects.
3046 * New configure options
3048 --with-auto-load-dir
3049 Configure default value for the 'set auto-load scripts-directory'
3050 setting above. It defaults to '$debugdir:$datadir/auto-load',
3051 $debugdir representing global debugging info directories (available
3052 via 'show debug-file-directory') and $datadir representing GDB's data
3053 directory (available via 'show data-directory').
3055 --with-auto-load-safe-path
3056 Configure default value for the 'set auto-load safe-path' setting
3057 above. It defaults to the --with-auto-load-dir setting.
3059 --without-auto-load-safe-path
3060 Set 'set auto-load safe-path' to '/', effectively disabling this
3063 * New remote packets
3065 z0/z1 conditional breakpoints extension
3067 The z0/z1 breakpoint insertion packets have been extended to carry
3068 a list of conditional expressions over to the remote stub depending on the
3069 condition evaluation mode. The use of this extension can be controlled
3070 via the "set remote conditional-breakpoints-packet" command.
3074 Specify the signals which the remote stub may pass to the debugged
3075 program without GDB involvement.
3077 * New command line options
3079 --init-command=FILE, -ix Like --command, -x but execute it
3080 before loading inferior.
3081 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3082 execute it before loading inferior.
3084 *** Changes in GDB 7.4
3086 * GDB now handles ambiguous linespecs more consistently; the existing
3087 FILE:LINE support has been expanded to other types of linespecs. A
3088 breakpoint will now be set on all matching locations in all
3089 inferiors, and locations will be added or removed according to
3092 * GDB now allows you to skip uninteresting functions and files when
3093 stepping with the "skip function" and "skip file" commands.
3095 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3096 and "show remote hardware-watchpoint-length-limit". These allows to
3097 set or show the maximum length limit (in bytes) of a remote
3098 target hardware watchpoint.
3100 This allows e.g. to use "unlimited" hardware watchpoints with the
3101 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3102 watchpoints are slower than real hardware watchpoints but are
3103 significantly faster than gdb software watchpoints.
3107 ** The register_pretty_printer function in module gdb.printing now takes
3108 an optional `replace' argument. If True, the new printer replaces any
3111 ** The "maint set python print-stack on|off" command has been
3112 deprecated and will be deleted in GDB 7.5.
3113 A new command: "set python print-stack none|full|message" has
3114 replaced it. Additionally, the default for "print-stack" is
3115 now "message", which just prints the error message without
3118 ** A prompt substitution hook (prompt_hook) is now available to the
3121 ** A new Python module, gdb.prompt has been added to the GDB Python
3122 modules library. This module provides functionality for
3123 escape sequences in prompts (used by set/show
3124 extended-prompt). These escape sequences are replaced by their
3125 corresponding value.
3127 ** Python commands and convenience-functions located in
3128 'data-directory'/python/gdb/command and
3129 'data-directory'/python/gdb/function are now automatically loaded
3132 ** Blocks now provide four new attributes. global_block and
3133 static_block will return the global and static blocks
3134 respectively. is_static and is_global are boolean attributes
3135 that indicate if the block is one of those two types.
3137 ** Symbols now provide the "type" attribute, the type of the symbol.
3139 ** The "gdb.breakpoint" function has been deprecated in favor of
3142 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3143 of a function. This class is based on the "finish" command
3144 available in the CLI.
3146 ** Type objects for struct and union types now allow access to
3147 the fields using standard Python dictionary (mapping) methods.
3148 For example, "some_type['myfield']" now works, as does
3149 "some_type.items()".
3151 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3154 ** A new function, "deep_items" has been added to the gdb.types
3155 module in the GDB Python modules library. This function returns
3156 an iterator over the fields of a struct or union type. Unlike
3157 the standard Python "iteritems" method, it will recursively traverse
3158 any anonymous fields.
3162 ** "*stopped" events can report several new "reason"s, such as
3165 ** Breakpoint changes are now notified using new async records, like
3166 "=breakpoint-modified".
3168 ** New command -ada-task-info.
3170 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3171 $sdir specifies the default system locations of shared libraries.
3172 $pdir specifies the directory where the libpthread used by the application
3175 GDB no longer looks in $sdir and $pdir after it has searched the directories
3176 mentioned in libthread-db-search-path. If you want to search those
3177 directories, they must be specified in libthread-db-search-path.
3178 The default value of libthread-db-search-path on GNU/Linux and Solaris
3179 systems is now "$sdir:$pdir".
3181 $pdir is not supported by gdbserver, it is currently ignored.
3182 $sdir is supported by gdbserver.
3184 * New configure option --with-iconv-bin.
3185 When using the internationalization support like the one in the GNU C
3186 library, GDB will invoke the "iconv" program to get a list of supported
3187 character sets. If this program lives in a non-standard location, one can
3188 use this option to specify where to find it.
3190 * When natively debugging programs on PowerPC BookE processors running
3191 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3192 watchpoints, which specify a mask in addition to an address to watch.
3193 The mask specifies that some bits of an address (the bits which are
3194 reset in the mask) should be ignored when matching the address accessed
3195 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3196 section in the user manual for more details.
3198 * The new option --once causes GDBserver to stop listening for connections once
3199 the first connection is made. The listening port used by GDBserver will
3200 become available after that.
3202 * New commands "info macros" and "alias" have been added.
3204 * New function parameters suffix @entry specifies value of function parameter
3205 at the time the function got called. Entry values are available only since
3211 "!" is now an alias of the "shell" command.
3212 Note that no space is needed between "!" and SHELL COMMAND.
3216 watch EXPRESSION mask MASK_VALUE
3217 The watch command now supports the mask argument which allows creation
3218 of masked watchpoints, if the current architecture supports this feature.
3220 info auto-load-scripts [REGEXP]
3221 This command was formerly named "maintenance print section-scripts".
3222 It is now generally useful and is no longer a maintenance-only command.
3224 info macro [-all] [--] MACRO
3225 The info macro command has new options `-all' and `--'. The first for
3226 printing all definitions of a macro. The second for explicitly specifying
3227 the end of arguments and the beginning of the macro name in case the macro
3228 name starts with a hyphen.
3230 collect[/s] EXPRESSIONS
3231 The tracepoint collect command now takes an optional modifier "/s"
3232 that directs it to dereference pointer-to-character types and
3233 collect the bytes of memory up to a zero byte. The behavior is
3234 similar to what you see when you use the regular print command on a
3235 string. An optional integer following the "/s" sets a bound on the
3236 number of bytes that will be collected.
3239 The trace start command now interprets any supplied arguments as a
3240 note to be recorded with the trace run, with an effect similar to
3241 setting the variable trace-notes.
3244 The trace stop command now interprets any arguments as a note to be
3245 mentioned along with the tstatus report that the trace was stopped
3246 with a command. The effect is similar to setting the variable
3249 * Tracepoints can now be enabled and disabled at any time after a trace
3250 experiment has been started using the standard "enable" and "disable"
3251 commands. It is now possible to start a trace experiment with no enabled
3252 tracepoints; GDB will display a warning, but will allow the experiment to
3253 begin, assuming that tracepoints will be enabled as needed while the trace
3256 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3257 locations with 4-byte instructions, when they were previously
3258 limited to locations with instructions of 5 bytes or longer.
3262 set debug dwarf2-read
3263 show debug dwarf2-read
3264 Turns on or off display of debugging messages related to reading
3265 DWARF debug info. The default is off.
3267 set debug symtab-create
3268 show debug symtab-create
3269 Turns on or off display of debugging messages related to symbol table
3270 creation. The default is off.
3273 show extended-prompt
3274 Set the GDB prompt, and allow escape sequences to be inserted to
3275 display miscellaneous information (see 'help set extended-prompt'
3276 for the list of sequences). This prompt (and any information
3277 accessed through the escape sequences) is updated every time the
3278 prompt is displayed.
3280 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3281 show print entry-values
3282 Set printing of frame argument values at function entry. In some cases
3283 GDB can determine the value of function argument which was passed by the
3284 function caller, even if the value was modified inside the called function.
3286 set debug entry-values
3287 show debug entry-values
3288 Control display of debugging info for determining frame argument values at
3289 function entry and virtual tail call frames.
3291 set basenames-may-differ
3292 show basenames-may-differ
3293 Set whether a source file may have multiple base names.
3294 (A "base name" is the name of a file with the directory part removed.
3295 Example: The base name of "/home/user/hello.c" is "hello.c".)
3296 If set, GDB will canonicalize file names (e.g., expand symlinks)
3297 before comparing them. Canonicalization is an expensive operation,
3298 but it allows the same file be known by more than one base name.
3299 If not set (the default), all source files are assumed to have just
3300 one base name, and gdb will do file name comparisons more efficiently.
3306 Set a user name and notes for the current and any future trace runs.
3307 This is useful for long-running and/or disconnected traces, to
3308 inform others (or yourself) as to who is running the trace, supply
3309 contact information, or otherwise explain what is going on.
3311 set trace-stop-notes
3312 show trace-stop-notes
3313 Set a note attached to the trace run, that is displayed when the
3314 trace has been stopped by a tstop command. This is useful for
3315 instance as an explanation, if you are stopping a trace run that was
3316 started by someone else.
3318 * New remote packets
3322 Dynamically enable a tracepoint in a started trace experiment.
3326 Dynamically disable a tracepoint in a started trace experiment.
3330 Set the user and notes of the trace run.
3334 Query the current status of a tracepoint.
3338 Query the minimum length of instruction at which a fast tracepoint may
3341 * Dcache size (number of lines) and line-size are now runtime-configurable
3342 via "set dcache line" and "set dcache line-size" commands.
3346 Texas Instruments TMS320C6x tic6x-*-*
3350 Renesas RL78 rl78-*-elf
3352 *** Changes in GDB 7.3.1
3354 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3356 *** Changes in GDB 7.3
3358 * GDB has a new command: "thread find [REGEXP]".
3359 It finds the thread id whose name, target id, or thread extra info
3360 matches the given regular expression.
3362 * The "catch syscall" command now works on mips*-linux* targets.
3364 * The -data-disassemble MI command now supports modes 2 and 3 for
3365 dumping the instruction opcodes.
3367 * New command line options
3369 -data-directory DIR Specify DIR as the "data-directory".
3370 This is mostly for testing purposes.
3372 * The "maint set python auto-load on|off" command has been renamed to
3373 "set auto-load-scripts on|off".
3375 * GDB has a new command: "set directories".
3376 It is like the "dir" command except that it replaces the
3377 source path list instead of augmenting it.
3379 * GDB now understands thread names.
3381 On GNU/Linux, "info threads" will display the thread name as set by
3382 prctl or pthread_setname_np.
3384 There is also a new command, "thread name", which can be used to
3385 assign a name internally for GDB to display.
3388 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3389 has been integrated into GDB.
3393 ** The function gdb.Write now accepts an optional keyword 'stream'.
3394 This keyword, when provided, will direct the output to either
3395 stdout, stderr, or GDB's logging output.
3397 ** Parameters can now be be sub-classed in Python, and in particular
3398 you may implement the get_set_doc and get_show_doc functions.
3399 This improves how Parameter set/show documentation is processed
3400 and allows for more dynamic content.
3402 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3403 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3404 have an is_valid method.
3406 ** Breakpoints can now be sub-classed in Python, and in particular
3407 you may implement a 'stop' function that is executed each time
3408 the inferior reaches that breakpoint.
3410 ** New function gdb.lookup_global_symbol looks up a global symbol.
3412 ** GDB values in Python are now callable if the value represents a
3413 function. For example, if 'some_value' represents a function that
3414 takes two integer parameters and returns a value, you can call
3415 that function like so:
3417 result = some_value (10,20)
3419 ** Module gdb.types has been added.
3420 It contains a collection of utilities for working with gdb.Types objects:
3421 get_basic_type, has_field, make_enum_dict.
3423 ** Module gdb.printing has been added.
3424 It contains utilities for writing and registering pretty-printers.
3425 New classes: PrettyPrinter, SubPrettyPrinter,
3426 RegexpCollectionPrettyPrinter.
3427 New function: register_pretty_printer.
3429 ** New commands "info pretty-printers", "enable pretty-printer" and
3430 "disable pretty-printer" have been added.
3432 ** gdb.parameter("directories") is now available.
3434 ** New function gdb.newest_frame returns the newest frame in the
3437 ** The gdb.InferiorThread class has a new "name" attribute. This
3438 holds the thread's name.
3440 ** Python Support for Inferior events.
3441 Python scripts can add observers to be notified of events
3442 occurring in the process being debugged.
3443 The following events are currently supported:
3444 - gdb.events.cont Continue event.
3445 - gdb.events.exited Inferior exited event.
3446 - gdb.events.stop Signal received, and Breakpoint hit events.
3450 ** GDB now puts template parameters in scope when debugging in an
3451 instantiation. For example, if you have:
3453 template<int X> int func (void) { return X; }
3455 then if you step into func<5>, "print X" will show "5". This
3456 feature requires proper debuginfo support from the compiler; it
3457 was added to GCC 4.5.
3459 ** The motion commands "next", "finish", "until", and "advance" now
3460 work better when exceptions are thrown. In particular, GDB will
3461 no longer lose control of the inferior; instead, the GDB will
3462 stop the inferior at the point at which the exception is caught.
3463 This functionality requires a change in the exception handling
3464 code that was introduced in GCC 4.5.
3466 * GDB now follows GCC's rules on accessing volatile objects when
3467 reading or writing target state during expression evaluation.
3468 One notable difference to prior behavior is that "print x = 0"
3469 no longer generates a read of x; the value of the assignment is
3470 now always taken directly from the value being assigned.
3472 * GDB now has some support for using labels in the program's source in
3473 linespecs. For instance, you can use "advance label" to continue
3474 execution to a label.
3476 * GDB now has support for reading and writing a new .gdb_index
3477 section. This section holds a fast index of DWARF debugging
3478 information and can be used to greatly speed up GDB startup and
3479 operation. See the documentation for `save gdb-index' for details.
3481 * The "watch" command now accepts an optional "-location" argument.
3482 When used, this causes GDB to watch the memory referred to by the
3483 expression. Such a watchpoint is never deleted due to it going out
3486 * GDB now supports thread debugging of core dumps on GNU/Linux.
3488 GDB now activates thread debugging using the libthread_db library
3489 when debugging GNU/Linux core dumps, similarly to when debugging
3490 live processes. As a result, when debugging a core dump file, GDB
3491 is now able to display pthread_t ids of threads. For example, "info
3492 threads" shows the same output as when debugging the process when it
3493 was live. In earlier releases, you'd see something like this:
3496 * 1 LWP 6780 main () at main.c:10
3498 While now you see this:
3501 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3503 It is also now possible to inspect TLS variables when debugging core
3506 When debugging a core dump generated on a machine other than the one
3507 used to run GDB, you may need to point GDB at the correct
3508 libthread_db library with the "set libthread-db-search-path"
3509 command. See the user manual for more details on this command.
3511 * When natively debugging programs on PowerPC BookE processors running
3512 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3513 which stop execution of the inferior whenever it executes an instruction
3514 at any address within the specified range. See the "PowerPC Embedded"
3515 section in the user manual for more details.
3517 * New features in the GDB remote stub, GDBserver
3519 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3520 and i686 LynxOS (version 5.x).
3522 ** GDBserver is now supported on Blackfin Linux.
3524 * New native configurations
3526 ia64 HP-UX ia64-*-hpux*
3530 Analog Devices, Inc. Blackfin Processor bfin-*
3532 * Ada task switching is now supported on sparc-elf targets when
3533 debugging a program using the Ravenscar Profile. For more information,
3534 see the "Tasking Support when using the Ravenscar Profile" section
3535 in the GDB user manual.
3537 * Guile support was removed.
3539 * New features in the GNU simulator
3541 ** The --map-info flag lists all known core mappings.
3543 ** CFI flashes may be simulated via the "cfi" device.
3545 *** Changes in GDB 7.2
3547 * Shared library support for remote targets by default
3549 When GDB is configured for a generic, non-OS specific target, like
3550 for example, --target=arm-eabi or one of the many *-*-elf targets,
3551 GDB now queries remote stubs for loaded shared libraries using the
3552 `qXfer:libraries:read' packet. Previously, shared library support
3553 was always disabled for such configurations.
3557 ** Argument Dependent Lookup (ADL)
3559 In C++ ADL lookup directs function search to the namespaces of its
3560 arguments even if the namespace has not been imported.
3570 Here the compiler will search for `foo' in the namespace of 'b'
3571 and find A::foo. GDB now supports this. This construct is commonly
3572 used in the Standard Template Library for operators.
3574 ** Improved User Defined Operator Support
3576 In addition to member operators, GDB now supports lookup of operators
3577 defined in a namespace and imported with a `using' directive, operators
3578 defined in the global scope, operators imported implicitly from an
3579 anonymous namespace, and the ADL operators mentioned in the previous
3581 GDB now also supports proper overload resolution for all the previously
3582 mentioned flavors of operators.
3584 ** static const class members
3586 Printing of static const class members that are initialized in the
3587 class definition has been fixed.
3589 * Windows Thread Information Block access.
3591 On Windows targets, GDB now supports displaying the Windows Thread
3592 Information Block (TIB) structure. This structure is visible either
3593 by using the new command `info w32 thread-information-block' or, by
3594 dereferencing the new convenience variable named `$_tlb', a
3595 thread-specific pointer to the TIB. This feature is also supported
3596 when remote debugging using GDBserver.
3598 * Static tracepoints
3600 Static tracepoints are calls in the user program into a tracing
3601 library. One such library is a port of the LTTng kernel tracer to
3602 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3603 When debugging with GDBserver, GDB now supports combining the GDB
3604 tracepoint machinery with such libraries. For example: the user can
3605 use GDB to probe a static tracepoint marker (a call from the user
3606 program into the tracing library) with the new "strace" command (see
3607 "New commands" below). This creates a "static tracepoint" in the
3608 breakpoint list, that can be manipulated with the same feature set
3609 as fast and regular tracepoints. E.g., collect registers, local and
3610 global variables, collect trace state variables, and define
3611 tracepoint conditions. In addition, the user can collect extra
3612 static tracepoint marker specific data, by collecting the new
3613 $_sdata internal variable. When analyzing the trace buffer, you can
3614 inspect $_sdata like any other variable available to GDB. For more
3615 information, see the "Tracepoints" chapter in GDB user manual. New
3616 remote packets have been defined to support static tracepoints, see
3617 the "New remote packets" section below.
3619 * Better reconstruction of tracepoints after disconnected tracing
3621 GDB will attempt to download the original source form of tracepoint
3622 definitions when starting a trace run, and then will upload these
3623 upon reconnection to the target, resulting in a more accurate
3624 reconstruction of the tracepoints that are in use on the target.
3628 You can now exercise direct control over the ways that GDB can
3629 affect your program. For instance, you can disallow the setting of
3630 breakpoints, so that the program can run continuously (assuming
3631 non-stop mode). In addition, the "observer" variable is available
3632 to switch all of the different controls; in observer mode, GDB
3633 cannot affect the target's behavior at all, which is useful for
3634 tasks like diagnosing live systems in the field.
3636 * The new convenience variable $_thread holds the number of the
3639 * New remote packets
3643 Return the address of the Windows Thread Information Block of a given thread.
3647 In response to several of the tracepoint packets, the target may now
3648 also respond with a number of intermediate `qRelocInsn' request
3649 packets before the final result packet, to have GDB handle
3650 relocating an instruction to execute at a different address. This
3651 is particularly useful for stubs that support fast tracepoints. GDB
3652 reports support for this feature in the qSupported packet.
3656 List static tracepoint markers in the target program.
3660 List static tracepoint markers at a given address in the target
3663 qXfer:statictrace:read
3665 Read the static trace data collected (by a `collect $_sdata'
3666 tracepoint action). The remote stub reports support for this packet
3667 to gdb's qSupported query.
3671 Send the current settings of GDB's permission flags.
3675 Send part of the source (textual) form of a tracepoint definition,
3676 which includes location, conditional, and action list.
3678 * The source command now accepts a -s option to force searching for the
3679 script in the source search path even if the script name specifies
3682 * New features in the GDB remote stub, GDBserver
3684 - GDBserver now support tracepoints (including fast tracepoints, and
3685 static tracepoints). The feature is currently supported by the
3686 i386-linux and amd64-linux builds. See the "Tracepoints support
3687 in gdbserver" section in the manual for more information.
3689 GDBserver JIT compiles the tracepoint's conditional agent
3690 expression bytecode into native code whenever possible for low
3691 overhead dynamic tracepoints conditionals. For such tracepoints,
3692 an expression that examines program state is evaluated when the
3693 tracepoint is reached, in order to determine whether to capture
3694 trace data. If the condition is simple and false, processing the
3695 tracepoint finishes very quickly and no data is gathered.
3697 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3698 for static tracepoints support.
3700 - GDBserver now supports x86_64 Windows 64-bit debugging.
3702 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3703 it understands register description.
3705 * The --batch flag now disables pagination and queries.
3707 * X86 general purpose registers
3709 GDB now supports reading/writing byte, word and double-word x86
3710 general purpose registers directly. This means you can use, say,
3711 $ah or $ax to refer, respectively, to the byte register AH and
3712 16-bit word register AX that are actually portions of the 32-bit
3713 register EAX or 64-bit register RAX.
3715 * The `commands' command now accepts a range of breakpoints to modify.
3716 A plain `commands' following a command that creates multiple
3717 breakpoints affects all the breakpoints set by that command. This
3718 applies to breakpoints set by `rbreak', and also applies when a
3719 single `break' command creates multiple breakpoints (e.g.,
3720 breakpoints on overloaded c++ functions).
3722 * The `rbreak' command now accepts a filename specification as part of
3723 its argument, limiting the functions selected by the regex to those
3724 in the specified file.
3726 * Support for remote debugging Windows and SymbianOS shared libraries
3727 from Unix hosts has been improved. Non Windows GDB builds now can
3728 understand target reported file names that follow MS-DOS based file
3729 system semantics, such as file names that include drive letters and
3730 use the backslash character as directory separator. This makes it
3731 possible to transparently use the "set sysroot" and "set
3732 solib-search-path" on Unix hosts to point as host copies of the
3733 target's shared libraries. See the new command "set
3734 target-file-system-kind" described below, and the "Commands to
3735 specify files" section in the user manual for more information.
3739 eval template, expressions...
3740 Convert the values of one or more expressions under the control
3741 of the string template to a command line, and call it.
3743 set target-file-system-kind unix|dos-based|auto
3744 show target-file-system-kind
3745 Set or show the assumed file system kind for target reported file
3748 save breakpoints <filename>
3749 Save all current breakpoint definitions to a file suitable for use
3750 in a later debugging session. To read the saved breakpoint
3751 definitions, use the `source' command.
3753 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3756 info static-tracepoint-markers
3757 Display information about static tracepoint markers in the target.
3759 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3760 Define a static tracepoint by probing a marker at the given
3761 function, line, address, or marker ID.
3765 Enable and disable observer mode.
3767 set may-write-registers on|off
3768 set may-write-memory on|off
3769 set may-insert-breakpoints on|off
3770 set may-insert-tracepoints on|off
3771 set may-insert-fast-tracepoints on|off
3772 set may-interrupt on|off
3773 Set individual permissions for GDB effects on the target. Note that
3774 some of these settings can have undesirable or surprising
3775 consequences, particularly when changed in the middle of a session.
3776 For instance, disabling the writing of memory can prevent
3777 breakpoints from being inserted, cause single-stepping to fail, or
3778 even crash your program, if you disable after breakpoints have been
3779 inserted. However, GDB should not crash.
3781 set record memory-query on|off
3782 show record memory-query
3783 Control whether to stop the inferior if memory changes caused
3784 by an instruction cannot be recorded.
3789 The disassemble command now supports "start,+length" form of two arguments.
3793 ** GDB now provides a new directory location, called the python directory,
3794 where Python scripts written for GDB can be installed. The location
3795 of that directory is <data-directory>/python, where <data-directory>
3796 is the GDB data directory. For more details, see section `Scripting
3797 GDB using Python' in the manual.
3799 ** The GDB Python API now has access to breakpoints, symbols, symbol
3800 tables, program spaces, inferiors, threads and frame's code blocks.
3801 Additionally, GDB Parameters can now be created from the API, and
3802 manipulated via set/show in the CLI.
3804 ** New functions gdb.target_charset, gdb.target_wide_charset,
3805 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3807 ** New exception gdb.GdbError.
3809 ** Pretty-printers are now also looked up in the current program space.
3811 ** Pretty-printers can now be individually enabled and disabled.
3813 ** GDB now looks for names of Python scripts to auto-load in a
3814 special section named `.debug_gdb_scripts', in addition to looking
3815 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3817 * Tracepoint actions were unified with breakpoint commands. In particular,
3818 there are no longer differences in "info break" output for breakpoints and
3819 tracepoints and the "commands" command can be used for both tracepoints and
3820 regular breakpoints.
3824 ARM Symbian arm*-*-symbianelf*
3826 * D language support.
3827 GDB now supports debugging programs written in the D programming
3830 * GDB now supports the extended ptrace interface for PowerPC which is
3831 available since Linux kernel version 2.6.34. This automatically enables
3832 any hardware breakpoints and additional hardware watchpoints available in
3833 the processor. The old ptrace interface exposes just one hardware
3834 watchpoint and no hardware breakpoints.
3836 * GDB is now able to use the Data Value Compare (DVC) register available on
3837 embedded PowerPC processors to implement in hardware simple watchpoint
3838 conditions of the form:
3840 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3842 This works in native GDB running on Linux kernels with the extended ptrace
3843 interface mentioned above.
3845 *** Changes in GDB 7.1
3849 ** Namespace Support
3851 GDB now supports importing of namespaces in C++. This enables the
3852 user to inspect variables from imported namespaces. Support for
3853 namepace aliasing has also been added. So, if a namespace is
3854 aliased in the current scope (e.g. namepace C=A; ) the user can
3855 print variables using the alias (e.g. (gdb) print C::x).
3859 All known bugs relating to the printing of virtual base class were
3860 fixed. It is now possible to call overloaded static methods using a
3865 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3866 and reinterpret_cast<> are now handled by the C++ expression parser.
3870 Xilinx MicroBlaze microblaze-*-*
3875 Xilinx MicroBlaze microblaze
3878 * Multi-program debugging.
3880 GDB now has support for multi-program (a.k.a. multi-executable or
3881 multi-exec) debugging. This allows for debugging multiple inferiors
3882 simultaneously each running a different program under the same GDB
3883 session. See "Debugging Multiple Inferiors and Programs" in the
3884 manual for more information. This implied some user visible changes
3885 in the multi-inferior support. For example, "info inferiors" now
3886 lists inferiors that are not running yet or that have exited
3887 already. See also "New commands" and "New options" below.
3889 * New tracing features
3891 GDB's tracepoint facility now includes several new features:
3893 ** Trace state variables
3895 GDB tracepoints now include support for trace state variables, which
3896 are variables managed by the target agent during a tracing
3897 experiment. They are useful for tracepoints that trigger each
3898 other, so for instance one tracepoint can count hits in a variable,
3899 and then a second tracepoint has a condition that is true when the
3900 count reaches a particular value. Trace state variables share the
3901 $-syntax of GDB convenience variables, and can appear in both
3902 tracepoint actions and condition expressions. Use the "tvariable"
3903 command to create, and "info tvariables" to view; see "Trace State
3904 Variables" in the manual for more detail.
3908 GDB now includes an option for defining fast tracepoints, which
3909 targets may implement more efficiently, such as by installing a jump
3910 into the target agent rather than a trap instruction. The resulting
3911 speedup can be by two orders of magnitude or more, although the
3912 tradeoff is that some program locations on some target architectures
3913 might not allow fast tracepoint installation, for instance if the
3914 instruction to be replaced is shorter than the jump. To request a
3915 fast tracepoint, use the "ftrace" command, with syntax identical to
3916 the regular trace command.
3918 ** Disconnected tracing
3920 It is now possible to detach GDB from the target while it is running
3921 a trace experiment, then reconnect later to see how the experiment
3922 is going. In addition, a new variable disconnected-tracing lets you
3923 tell the target agent whether to continue running a trace if the
3924 connection is lost unexpectedly.
3928 GDB now has the ability to save the trace buffer into a file, and
3929 then use that file as a target, similarly to you can do with
3930 corefiles. You can select trace frames, print data that was
3931 collected in them, and use tstatus to display the state of the
3932 tracing run at the moment that it was saved. To create a trace
3933 file, use "tsave <filename>", and to use it, do "target tfile
3936 ** Circular trace buffer
3938 You can ask the target agent to handle the trace buffer as a
3939 circular buffer, discarding the oldest trace frames to make room for
3940 newer ones, by setting circular-trace-buffer to on. This feature may
3941 not be available for all target agents.
3946 The disassemble command, when invoked with two arguments, now requires
3947 the arguments to be comma-separated.
3950 The info variables command now displays variable definitions. Files
3951 which only declare a variable are not shown.
3954 The source command is now capable of sourcing Python scripts.
3955 This feature is dependent on the debugger being build with Python
3958 Related to this enhancement is also the introduction of a new command
3959 "set script-extension" (see below).
3961 * New commands (for set/show, see "New options" below)
3963 record save [<FILENAME>]
3964 Save a file (in core file format) containing the process record
3965 execution log for replay debugging at a later time.
3967 record restore <FILENAME>
3968 Restore the process record execution log that was saved at an
3969 earlier time, for replay debugging.
3971 add-inferior [-copies <N>] [-exec <FILENAME>]
3974 clone-inferior [-copies <N>] [ID]
3975 Make a new inferior ready to execute the same program another
3976 inferior has loaded.
3981 maint info program-spaces
3982 List the program spaces loaded into GDB.
3984 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3985 show remote interrupt-sequence
3986 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3987 as the sequence to the remote target in order to interrupt the execution.
3988 Ctrl-C is a default. Some system prefers BREAK which is high level of
3989 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3990 Magic SysRq g. It is BREAK signal and character 'g'.
3992 set remote interrupt-on-connect [on | off]
3993 show remote interrupt-on-connect
3994 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3995 remote target when gdb connects to it. This is needed when you debug
3998 set remotebreak [on | off]
4000 Deprecated. Use "set/show remote interrupt-sequence" instead.
4002 tvariable $NAME [ = EXP ]
4003 Create or modify a trace state variable.
4006 List trace state variables and their values.
4008 delete tvariable $NAME ...
4009 Delete one or more trace state variables.
4012 Evaluate the given expressions without collecting anything into the
4013 trace buffer. (Valid in tracepoint actions only.)
4015 ftrace FN / FILE:LINE / *ADDR
4016 Define a fast tracepoint at the given function, line, or address.
4018 * New expression syntax
4020 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4021 GDB now parses 0b101010 identically with 42.
4025 set follow-exec-mode new|same
4026 show follow-exec-mode
4027 Control whether GDB reuses the same inferior across an exec call or
4028 creates a new one. This is useful to be able to restart the old
4029 executable after the inferior having done an exec call.
4031 set default-collect EXPR, ...
4032 show default-collect
4033 Define a list of expressions to be collected at each tracepoint.
4034 This is a useful way to ensure essential items are not overlooked,
4035 such as registers or a critical global variable.
4037 set disconnected-tracing
4038 show disconnected-tracing
4039 If set to 1, the target is instructed to continue tracing if it
4040 loses its connection to GDB. If 0, the target is to stop tracing
4043 set circular-trace-buffer
4044 show circular-trace-buffer
4045 If set to on, the target is instructed to use a circular trace buffer
4046 and discard the oldest trace frames instead of stopping the trace due
4047 to a full trace buffer. If set to off, the trace stops when the buffer
4048 fills up. Some targets may not support this.
4050 set script-extension off|soft|strict
4051 show script-extension
4052 If set to "off", the debugger does not perform any script language
4053 recognition, and all sourced files are assumed to be GDB scripts.
4054 If set to "soft" (the default), files are sourced according to
4055 filename extension, falling back to GDB scripts if the first
4057 If set to "strict", files are sourced according to filename extension.
4059 set ada trust-PAD-over-XVS on|off
4060 show ada trust-PAD-over-XVS
4061 If off, activate a workaround against a bug in the debugging information
4062 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4063 the GCC sources for more information about the GNAT encoding and
4064 PAD types in particular). It is always safe to set this option to
4065 off, but this introduces a slight performance penalty. The default
4068 * Python API Improvements
4070 ** GDB provides the new class gdb.LazyString. This is useful in
4071 some pretty-printing cases. The new method gdb.Value.lazy_string
4072 provides a simple way to create objects of this type.
4074 ** The fields returned by gdb.Type.fields now have an
4075 `is_base_class' attribute.
4077 ** The new method gdb.Type.range returns the range of an array type.
4079 ** The new method gdb.parse_and_eval can be used to parse and
4080 evaluate an expression.
4082 * New remote packets
4085 Define a trace state variable.
4088 Get the current value of a trace state variable.
4091 Set desired tracing behavior upon disconnection.
4094 Set the trace buffer to be linear or circular.
4097 Get data about the tracepoints currently in use.
4101 Process record now works correctly with hardware watchpoints.
4103 Multiple bug fixes have been made to the mips-irix port, making it
4104 much more reliable. In particular:
4105 - Debugging threaded applications is now possible again. Previously,
4106 GDB would hang while starting the program, or while waiting for
4107 the program to stop at a breakpoint.
4108 - Attaching to a running process no longer hangs.
4109 - An error occurring while loading a core file has been fixed.
4110 - Changing the value of the PC register now works again. This fixes
4111 problems observed when using the "jump" command, or when calling
4112 a function from GDB, or even when assigning a new value to $pc.
4113 - With the "finish" and "return" commands, the return value for functions
4114 returning a small array is now correctly printed.
4115 - It is now possible to break on shared library code which gets executed
4116 during a shared library init phase (code executed while executing
4117 their .init section). Previously, the breakpoint would have no effect.
4118 - GDB is now able to backtrace through the signal handler for
4119 non-threaded programs.
4121 PIE (Position Independent Executable) programs debugging is now supported.
4122 This includes debugging execution of PIC (Position Independent Code) shared
4123 libraries although for that, it should be possible to run such libraries as an
4126 *** Changes in GDB 7.0
4128 * GDB now has an interface for JIT compilation. Applications that
4129 dynamically generate code can create symbol files in memory and register
4130 them with GDB. For users, the feature should work transparently, and
4131 for JIT developers, the interface is documented in the GDB manual in the
4132 "JIT Compilation Interface" chapter.
4134 * Tracepoints may now be conditional. The syntax is as for
4135 breakpoints; either an "if" clause appended to the "trace" command,
4136 or the "condition" command is available. GDB sends the condition to
4137 the target for evaluation using the same bytecode format as is used
4138 for tracepoint actions.
4140 * The disassemble command now supports: an optional /r modifier, print the
4141 raw instructions in hex as well as in symbolic form, and an optional /m
4142 modifier to print mixed source+assembly.
4144 * Process record and replay
4146 In a architecture environment that supports ``process record and
4147 replay'', ``process record and replay'' target can record a log of
4148 the process execution, and replay it with both forward and reverse
4151 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4152 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4153 set execution-direction {forward|reverse}, for targets that support
4156 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4157 feature is available with a native GDB running on kernel version
4160 * GDB now has support for multi-byte and wide character sets on the
4161 target. Strings whose character type is wchar_t, char16_t, or
4162 char32_t are now correctly printed. GDB supports wide- and unicode-
4163 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4164 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4165 `printf'. This feature requires iconv to work properly; if your
4166 system does not have a working iconv, GDB can use GNU libiconv. See
4167 the installation instructions for more information.
4169 * GDB now supports automatic retrieval of shared library files from
4170 remote targets. To use this feature, specify a system root that begins
4171 with the `remote:' prefix, either via the `set sysroot' command or via
4172 the `--with-sysroot' configure-time option.
4174 * "info sharedlibrary" now takes an optional regex of libraries to show,
4175 and it now reports if a shared library has no debugging information.
4177 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4178 now complete on file names.
4180 * When completing in expressions, gdb will attempt to limit
4181 completions to allowable structure or union fields, where appropriate.
4182 For instance, consider:
4184 # struct example { int f1; double f2; };
4185 # struct example variable;
4188 If the user types TAB at the end of this command line, the available
4189 completions will be "f1" and "f2".
4191 * Inlined functions are now supported. They show up in backtraces, and
4192 the "step", "next", and "finish" commands handle them automatically.
4194 * GDB now supports the token-splicing (##) and stringification (#)
4195 operators when expanding macros. It also supports variable-arity
4198 * GDB now supports inspecting extra signal information, exported by
4199 the new $_siginfo convenience variable. The feature is currently
4200 implemented on linux ARM, i386 and amd64.
4202 * GDB can now display the VFP floating point registers and NEON vector
4203 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4204 can provide these registers (requires Linux 2.6.30 or later). Remote
4205 and simulator targets may also provide them.
4207 * New remote packets
4210 Search memory for a sequence of bytes.
4213 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4214 operation over reliable transport links. Use of this packet is
4215 controlled by the `set remote noack-packet' command.
4218 Kill the process with the specified process ID. Use this in preference
4219 to `k' when multiprocess protocol extensions are supported.
4222 Obtains additional operating system information
4226 Read or write additional signal information.
4228 * Removed remote protocol undocumented extension
4230 An undocumented extension to the remote protocol's `S' stop reply
4231 packet that permited the stub to pass a process id was removed.
4232 Remote servers should use the `T' stop reply packet instead.
4234 * GDB now supports multiple function calling conventions according to the
4235 DWARF-2 DW_AT_calling_convention function attribute.
4237 * The SH target utilizes the aforementioned change to distinguish between gcc
4238 and Renesas calling convention. It also adds the new CLI commands
4239 `set/show sh calling-convention'.
4241 * GDB can now read compressed debug sections, as produced by GNU gold
4242 with the --compress-debug-sections=zlib flag.
4244 * 64-bit core files are now supported on AIX.
4246 * Thread switching is now supported on Tru64.
4248 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4249 which will be allocated using malloc later in program execution.
4251 * The qXfer:libraries:read remote procotol packet now allows passing a
4252 list of section offsets.
4254 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4255 conditions handling signals delivered during attach or thread creation
4256 have also been fixed.
4258 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4259 From the user's standpoint, all unqualified instances of True and False
4260 are treated as the standard definitions, regardless of context.
4262 * GDB now parses C++ symbol and type names more flexibly. For
4265 template<typename T> class C { };
4268 GDB will now correctly handle all of:
4270 ptype C<char const *>
4271 ptype C<char const*>
4272 ptype C<const char *>
4273 ptype C<const char*>
4275 * New features in the GDB remote stub, gdbserver
4277 - The "--wrapper" command-line argument tells gdbserver to use a
4278 wrapper program to launch programs for debugging.
4280 - On PowerPC and S/390 targets, it is now possible to use a single
4281 gdbserver executable to debug both 32-bit and 64-bit programs.
4282 (This requires gdbserver itself to be built as a 64-bit executable.)
4284 - gdbserver uses the new noack protocol mode for TCP connections to
4285 reduce communications latency, if also supported and enabled in GDB.
4287 - Support for the sparc64-linux-gnu target is now included in
4290 - The amd64-linux build of gdbserver now supports debugging both
4291 32-bit and 64-bit programs.
4293 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4294 now support hardware watchpoints, and will use them automatically
4299 GDB now has support for scripting using Python. Whether this is
4300 available is determined at configure time.
4302 New GDB commands can now be written in Python.
4304 * Ada tasking support
4306 Ada tasks can now be inspected in GDB. The following commands have
4310 Print the list of Ada tasks.
4312 Print detailed information about task number N.
4314 Print the task number of the current task.
4316 Switch the context of debugging to task number N.
4318 * Support for user-defined prefixed commands. The "define" command can
4319 add new commands to existing prefixes, e.g. "target".
4321 * Multi-inferior, multi-process debugging.
4323 GDB now has generalized support for multi-inferior debugging. See
4324 "Debugging Multiple Inferiors" in the manual for more information.
4325 Although availability still depends on target support, the command
4326 set is more uniform now. The GNU/Linux specific multi-forks support
4327 has been migrated to this new framework. This implied some user
4328 visible changes; see "New commands" and also "Removed commands"
4331 * Target descriptions can now describe the target OS ABI. See the
4332 "Target Description Format" section in the user manual for more
4335 * Target descriptions can now describe "compatible" architectures
4336 to indicate that the target can execute applications for a different
4337 architecture in addition to those for the main target architecture.
4338 See the "Target Description Format" section in the user manual for
4341 * Multi-architecture debugging.
4343 GDB now includes general supports for debugging applications on
4344 hybrid systems that use more than one single processor architecture
4345 at the same time. Each such hybrid architecture still requires
4346 specific support to be added. The only hybrid architecture supported
4347 in this version of GDB is the Cell Broadband Engine.
4349 * GDB now supports integrated debugging of Cell/B.E. applications that
4350 use both the PPU and SPU architectures. To enable support for hybrid
4351 Cell/B.E. debugging, you need to configure GDB to support both the
4352 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4353 --enable-targets configure option.
4355 * Non-stop mode debugging.
4357 For some targets, GDB now supports an optional mode of operation in
4358 which you can examine stopped threads while other threads continue
4359 to execute freely. This is referred to as non-stop mode, with the
4360 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4361 section in the user manual for more information.
4363 To be able to support remote non-stop debugging, a remote stub needs
4364 to implement the non-stop mode remote protocol extensions, as
4365 described in the "Remote Non-Stop" section of the user manual. The
4366 GDB remote stub, gdbserver, has been adjusted to support these
4367 extensions on linux targets.
4369 * New commands (for set/show, see "New options" below)
4371 catch syscall [NAME(S) | NUMBER(S)]
4372 Catch system calls. Arguments, which should be names of system
4373 calls or their numbers, mean catch only those syscalls. Without
4374 arguments, every syscall will be caught. When the inferior issues
4375 any of the specified syscalls, GDB will stop and announce the system
4376 call, both when it is called and when its call returns. This
4377 feature is currently available with a native GDB running on the
4378 Linux Kernel, under the following architectures: x86, x86_64,
4379 PowerPC and PowerPC64.
4381 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4383 Search memory for a sequence of bytes.
4385 maint set python print-stack
4386 maint show python print-stack
4387 Show a stack trace when an error is encountered in a Python script.
4390 Invoke CODE by passing it to the Python interpreter.
4395 These allow macros to be defined, undefined, and listed
4399 Show operating system information about processes.
4402 List the inferiors currently under GDB's control.
4405 Switch focus to inferior number NUM.
4408 Detach from inferior number NUM.
4411 Kill inferior number NUM.
4415 set spu stop-on-load
4416 show spu stop-on-load
4417 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4419 set spu auto-flush-cache
4420 show spu auto-flush-cache
4421 Control whether to automatically flush the software-managed cache
4422 during Cell/B.E. debugging.
4424 set sh calling-convention
4425 show sh calling-convention
4426 Control the calling convention used when calling SH target functions.
4429 show debug timestamp
4430 Control display of timestamps with GDB debugging output.
4432 set disassemble-next-line
4433 show disassemble-next-line
4434 Control display of disassembled source lines or instructions when
4437 set remote noack-packet
4438 show remote noack-packet
4439 Set/show the use of remote protocol QStartNoAckMode packet. See above
4440 under "New remote packets."
4442 set remote query-attached-packet
4443 show remote query-attached-packet
4444 Control use of remote protocol `qAttached' (query-attached) packet.
4446 set remote read-siginfo-object
4447 show remote read-siginfo-object
4448 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4451 set remote write-siginfo-object
4452 show remote write-siginfo-object
4453 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4456 set remote reverse-continue
4457 show remote reverse-continue
4458 Control use of remote protocol 'bc' (reverse-continue) packet.
4460 set remote reverse-step
4461 show remote reverse-step
4462 Control use of remote protocol 'bs' (reverse-step) packet.
4464 set displaced-stepping
4465 show displaced-stepping
4466 Control displaced stepping mode. Displaced stepping is a way to
4467 single-step over breakpoints without removing them from the debuggee.
4468 Also known as "out-of-line single-stepping".
4471 show debug displaced
4472 Control display of debugging info for displaced stepping.
4474 maint set internal-error
4475 maint show internal-error
4476 Control what GDB does when an internal error is detected.
4478 maint set internal-warning
4479 maint show internal-warning
4480 Control what GDB does when an internal warning is detected.
4485 Use a wrapper program to launch programs for debugging.
4487 set multiple-symbols (all|ask|cancel)
4488 show multiple-symbols
4489 The value of this variable can be changed to adjust the debugger behavior
4490 when an expression or a breakpoint location contains an ambiguous symbol
4491 name (an overloaded function name, for instance).
4493 set breakpoint always-inserted
4494 show breakpoint always-inserted
4495 Keep breakpoints always inserted in the target, as opposed to inserting
4496 them when resuming the target, and removing them when the target stops.
4497 This option can improve debugger performance on slow remote targets.
4499 set arm fallback-mode (arm|thumb|auto)
4500 show arm fallback-mode
4501 set arm force-mode (arm|thumb|auto)
4503 These commands control how ARM GDB determines whether instructions
4504 are ARM or Thumb. The default for both settings is auto, which uses
4505 the current CPSR value for instructions without symbols; previous
4506 versions of GDB behaved as if "set arm fallback-mode arm".
4508 set disable-randomization
4509 show disable-randomization
4510 Standalone programs run with the virtual address space randomization enabled
4511 by default on some platforms. This option keeps the addresses stable across
4512 multiple debugging sessions.
4516 Control whether other threads are stopped or not when some thread hits
4521 Requests that asynchronous execution is enabled in the target, if available.
4522 In this case, it's possible to resume target in the background, and interact
4523 with GDB while the target is running. "show target-async" displays the
4524 current state of asynchronous execution of the target.
4526 set target-wide-charset
4527 show target-wide-charset
4528 The target-wide-charset is the name of the character set that GDB
4529 uses when printing characters whose type is wchar_t.
4531 set tcp auto-retry (on|off)
4533 set tcp connect-timeout
4534 show tcp connect-timeout
4535 These commands allow GDB to retry failed TCP connections to a remote stub
4536 with a specified timeout period; this is useful if the stub is launched
4537 in parallel with GDB but may not be ready to accept connections immediately.
4539 set libthread-db-search-path
4540 show libthread-db-search-path
4541 Control list of directories which GDB will search for appropriate
4544 set schedule-multiple (on|off)
4545 show schedule-multiple
4546 Allow GDB to resume all threads of all processes or only threads of
4547 the current process.
4551 Use more aggressive caching for accesses to the stack. This improves
4552 performance of remote debugging (particularly backtraces) without
4553 affecting correctness.
4555 set interactive-mode (on|off|auto)
4556 show interactive-mode
4557 Control whether GDB runs in interactive mode (on) or not (off).
4558 When in interactive mode, GDB waits for the user to answer all
4559 queries. Otherwise, GDB does not wait and assumes the default
4560 answer. When set to auto (the default), GDB determines which
4561 mode to use based on the stdin settings.
4566 For program forks, this is replaced by the new more generic `info
4567 inferiors' command. To list checkpoints, you can still use the
4568 `info checkpoints' command, which was an alias for the `info forks'
4572 Replaced by the new `inferior' command. To switch between
4573 checkpoints, you can still use the `restart' command, which was an
4574 alias for the `fork' command.
4577 This is removed, since some targets don't have a notion of
4578 processes. To switch between processes, you can still use the
4579 `inferior' command using GDB's own inferior number.
4582 For program forks, this is replaced by the new more generic `kill
4583 inferior' command. To delete a checkpoint, you can still use the
4584 `delete checkpoint' command, which was an alias for the `delete
4588 For program forks, this is replaced by the new more generic `detach
4589 inferior' command. To detach a checkpoint, you can still use the
4590 `detach checkpoint' command, which was an alias for the `detach
4593 * New native configurations
4595 x86/x86_64 Darwin i[34567]86-*-darwin*
4597 x86_64 MinGW x86_64-*-mingw*
4601 Lattice Mico32 lm32-*
4602 x86 DICOS i[34567]86-*-dicos*
4603 x86_64 DICOS x86_64-*-dicos*
4606 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4607 (mingw32ce) debugging.
4613 These commands were actually not implemented on any target.
4615 *** Changes in GDB 6.8
4617 * New native configurations
4619 NetBSD/hppa hppa*-*netbsd*
4620 Xtensa GNU/Linux xtensa*-*-linux*
4624 NetBSD/hppa hppa*-*-netbsd*
4625 Xtensa GNU/Lunux xtensa*-*-linux*
4627 * Change in command line behavior -- corefiles vs. process ids.
4629 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4630 attaching to process NUMBER fails, GDB no longer attempts to open a
4631 core file named NUMBER. Attaching to a program using the -c option
4632 is no longer supported. Instead, use the '-p' or '--pid' options.
4634 * GDB can now be built as a native debugger for debugging Windows x86
4635 (mingw32) Portable Executable (PE) programs.
4637 * Pending breakpoints no longer change their number when their address
4640 * GDB now supports breakpoints with multiple locations,
4641 including breakpoints on C++ constructors, inside C++ templates,
4642 and in inlined functions.
4644 * GDB's ability to debug optimized code has been improved. GDB more
4645 accurately identifies function bodies and lexical blocks that occupy
4646 more than one contiguous range of addresses.
4648 * Target descriptions can now describe registers for PowerPC.
4650 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4651 registers on PowerPC targets.
4653 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4654 targets even when the libthread_db library is not available.
4656 * The GDB remote stub, gdbserver, now supports the new file transfer
4657 commands (remote put, remote get, and remote delete).
4659 * The GDB remote stub, gdbserver, now supports run and attach in
4660 extended-remote mode.
4662 * hppa*64*-*-hpux11* target broken
4663 The debugger is unable to start a program and fails with the following
4664 error: "Error trying to get information about dynamic linker".
4665 The gdb-6.7 release is also affected.
4667 * GDB now supports the --enable-targets= configure option to allow
4668 building a single GDB executable that supports multiple remote
4669 target architectures.
4671 * GDB now supports debugging C and C++ programs which use the
4672 Decimal Floating Point extension. In addition, the PowerPC target
4673 now has a set of pseudo-registers to inspect decimal float values
4674 stored in two consecutive float registers.
4676 * The -break-insert MI command can optionally create pending
4679 * Improved support for debugging Ada
4680 Many improvements to the Ada language support have been made. These
4682 - Better support for Ada2005 interface types
4683 - Improved handling of arrays and slices in general
4684 - Better support for Taft-amendment types
4685 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4687 - Improved command completion in Ada
4690 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4695 set print frame-arguments (all|scalars|none)
4696 show print frame-arguments
4697 The value of this variable can be changed to control which argument
4698 values should be printed by the debugger when displaying a frame.
4703 Transfer files to and from a remote target, and delete remote files.
4710 Transfer files to and from a remote target, and delete remote files.
4712 * New remote packets
4719 Open, close, read, write, and delete files on the remote system.
4722 Attach to an existing process on the remote system, in extended-remote
4726 Run a new process on the remote system, in extended-remote mode.
4728 *** Changes in GDB 6.7
4730 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4731 bfd, libiberty and opcodes, as revealed by static analysis donated by
4732 Coverity, Inc. (http://scan.coverity.com).
4734 * When looking up multiply-defined global symbols, GDB will now prefer the
4735 symbol definition in the current shared library if it was built using the
4736 -Bsymbolic linker option.
4738 * When the Text User Interface (TUI) is not configured, GDB will now
4739 recognize the -tui command-line option and print a message that the TUI
4742 * The GDB remote stub, gdbserver, now has lower overhead for high
4743 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4745 * GDB for MIPS targets now autodetects whether a remote target provides
4746 32-bit or 64-bit register values.
4748 * Support for C++ member pointers has been improved.
4750 * GDB now understands XML target descriptions, which specify the
4751 target's overall architecture. GDB can read a description from
4752 a local file or over the remote serial protocol.
4754 * Vectors of single-byte data use a new integer type which is not
4755 automatically displayed as character or string data.
4757 * The /s format now works with the print command. It displays
4758 arrays of single-byte integers and pointers to single-byte integers
4761 * Target descriptions can now describe target-specific registers,
4762 for architectures which have implemented the support (currently
4763 only ARM, M68K, and MIPS).
4765 * GDB and the GDB remote stub, gdbserver, now support the XScale
4768 * The GDB remote stub, gdbserver, has been updated to support
4769 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4770 has been rewritten to use the standard GDB remote protocol.
4772 * GDB can now step into C++ functions which are called through thunks.
4774 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4776 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4777 layout. It also supports a TextSeg= and DataSeg= response when only
4778 segment base addresses (rather than offsets) are available.
4780 * The /i format now outputs any trailing branch delay slot instructions
4781 immediately following the last instruction within the count specified.
4783 * The GDB remote protocol "T" stop reply packet now supports a
4784 "library" response. Combined with the new "qXfer:libraries:read"
4785 packet, this response allows GDB to debug shared libraries on targets
4786 where the operating system manages the list of loaded libraries (e.g.
4787 Windows and SymbianOS).
4789 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4790 (DLLs) on Windows and Windows CE targets.
4792 * GDB now supports a faster verification that a .debug file matches its binary
4793 according to its build-id signature, if the signature is present.
4799 Enable or disable hardware flow control (RTS/CTS) on the serial port
4800 when debugging using remote targets.
4802 set mem inaccessible-by-default
4803 show mem inaccessible-by-default
4804 If the target supplies a memory map, for instance via the remote
4805 protocol's "qXfer:memory-map:read" packet, setting this variable
4806 prevents GDB from accessing memory outside the memory map. This
4807 is useful for targets with memory mapped registers or which react
4808 badly to accesses of unmapped address space.
4810 set breakpoint auto-hw
4811 show breakpoint auto-hw
4812 If the target supplies a memory map, for instance via the remote
4813 protocol's "qXfer:memory-map:read" packet, setting this variable
4814 lets GDB use hardware breakpoints automatically for memory regions
4815 where it can not use software breakpoints. This covers both the
4816 "break" command and internal breakpoints used for other commands
4817 including "next" and "finish".
4820 catch exception unhandled
4821 Stop the program execution when Ada exceptions are raised.
4824 Stop the program execution when an Ada assertion failed.
4828 Set an alternate system root for target files. This is a more
4829 general version of "set solib-absolute-prefix", which is now
4830 an alias to "set sysroot".
4833 Provide extended SPU facility status information. This set of
4834 commands is available only when debugging the Cell/B.E. SPU
4837 * New native configurations
4839 OpenBSD/sh sh*-*openbsd*
4842 unset tdesc filename
4844 Use the specified local file as an XML target description, and do
4845 not query the target for its built-in description.
4849 OpenBSD/sh sh*-*-openbsd*
4850 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4851 Toshiba Media Processor mep-elf
4853 * New remote packets
4856 Ignore the specified signals; pass them directly to the debugged program
4857 without stopping other threads or reporting them to GDB.
4859 qXfer:features:read:
4860 Read an XML target description from the target, which describes its
4865 Read or write contents of an spufs file on the target system. These
4866 packets are available only on the Cell/B.E. SPU architecture.
4868 qXfer:libraries:read:
4869 Report the loaded shared libraries. Combined with new "T" packet
4870 response, this packet allows GDB to debug shared libraries on
4871 targets where the operating system manages the list of loaded
4872 libraries (e.g. Windows and SymbianOS).
4876 Support for these obsolete configurations has been removed.
4884 i[34567]86-*-lynxos*
4885 i[34567]86-*-netware*
4886 i[34567]86-*-sco3.2v5*
4887 i[34567]86-*-sco3.2v4*
4889 i[34567]86-*-sysv4.2*
4892 i[34567]86-*-unixware2*
4893 i[34567]86-*-unixware*
4902 * Other removed features
4909 Various m68k-only ROM monitors.
4916 Various Renesas ROM monitors and debugging interfaces for SH and
4921 Support for a Macraigor serial interface to on-chip debugging.
4922 GDB does not directly support the newer parallel or USB
4927 A debug information format. The predecessor to DWARF 2 and
4928 DWARF 3, which are still supported.
4930 Support for the HP aCC compiler on HP-UX/PA-RISC
4932 SOM-encapsulated symbolic debugging information, automatic
4933 invocation of pxdb, and the aCC custom C++ ABI. This does not
4934 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4935 with aCC can still be debugged on an assembly level.
4937 MIPS ".pdr" sections
4939 A MIPS-specific format used to describe stack frame layout
4940 in debugging information.
4944 GDB could work with an older version of Guile to debug
4945 the interpreter and Scheme programs running in it.
4947 set mips stack-arg-size
4948 set mips saved-gpreg-size
4950 Use "set mips abi" to control parameter passing for MIPS.
4952 *** Changes in GDB 6.6
4957 Cell Broadband Engine SPU spu-elf
4959 * GDB can now be configured as a cross-debugger targeting native Windows
4960 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4961 running on a Windows system over TCP/IP to debug Windows programs.
4963 * The GDB remote stub, gdbserver, has been updated to support Windows and
4964 Cygwin debugging. Both single-threaded and multi-threaded programs are
4967 * The "set trust-readonly-sections" command works again. This command was
4968 broken in GDB 6.3, 6.4, and 6.5.
4970 * The "load" command now supports writing to flash memory, if the remote
4971 stub provides the required support.
4973 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4974 longer requires symbolic debug information (e.g. DWARF-2).
4979 unset substitute-path
4980 show substitute-path
4981 Manage a list of substitution rules that GDB uses to rewrite the name
4982 of the directories where the sources are located. This can be useful
4983 for instance when the sources were moved to a different location
4984 between compilation and debugging.
4988 Print each CLI command as it is executed. Each command is prefixed with
4989 a number of `+' symbols representing the nesting depth.
4990 The source command now has a `-v' option to enable the same feature.
4994 The ARM Demon monitor support (RDP protocol, "target rdp").
4996 Kernel Object Display, an embedded debugging feature which only worked with
4997 an obsolete version of Cisco IOS.
4999 The 'set download-write-size' and 'show download-write-size' commands.
5001 * New remote packets
5004 Tell a stub about GDB client features, and request remote target features.
5005 The first feature implemented is PacketSize, which allows the target to
5006 specify the size of packets it can handle - to minimize the number of
5007 packets required and improve performance when connected to a remote
5011 Fetch an OS auxilliary vector from the remote stub. This packet is a
5012 more efficient replacement for qPart:auxv:read.
5014 qXfer:memory-map:read:
5015 Fetch a memory map from the remote stub, including information about
5016 RAM, ROM, and flash memory devices.
5021 Erase and program a flash memory device.
5023 * Removed remote packets
5026 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5027 used it, and only gdbserver implemented it.
5029 *** Changes in GDB 6.5
5033 Renesas M32C/M16C m32c-elf
5035 Morpho Technologies ms1 ms1-elf
5039 init-if-undefined Initialize a convenience variable, but
5040 only if it doesn't already have a value.
5042 The following commands are presently only implemented for native GNU/Linux:
5044 checkpoint Save a snapshot of the program state.
5046 restart <n> Return the program state to a
5047 previously saved state.
5049 info checkpoints List currently saved checkpoints.
5051 delete-checkpoint <n> Delete a previously saved checkpoint.
5053 set|show detach-on-fork Tell gdb whether to detach from a newly
5054 forked process, or to keep debugging it.
5056 info forks List forks of the user program that
5057 are available to be debugged.
5059 fork <n> Switch to debugging one of several
5060 forks of the user program that are
5061 available to be debugged.
5063 delete-fork <n> Delete a fork from the list of forks
5064 that are available to be debugged (and
5065 kill the forked process).
5067 detach-fork <n> Delete a fork from the list of forks
5068 that are available to be debugged (and
5069 allow the process to continue).
5073 Morpho Technologies ms2 ms1-elf
5075 * Improved Windows host support
5077 GDB now builds as a cross debugger hosted on i686-mingw32, including
5078 native console support, and remote communications using either
5079 network sockets or serial ports.
5081 * Improved Modula-2 language support
5083 GDB can now print most types in the Modula-2 syntax. This includes:
5084 basic types, set types, record types, enumerated types, range types,
5085 pointer types and ARRAY types. Procedure var parameters are correctly
5086 printed and hexadecimal addresses and character constants are also
5087 written in the Modula-2 syntax. Best results can be obtained by using
5088 GNU Modula-2 together with the -gdwarf-2 command line option.
5092 The ARM rdi-share module.
5094 The Netware NLM debug server.
5096 *** Changes in GDB 6.4
5098 * New native configurations
5100 OpenBSD/arm arm*-*-openbsd*
5101 OpenBSD/mips64 mips64-*-openbsd*
5105 Morpho Technologies ms1 ms1-elf
5107 * New command line options
5109 --batch-silent As for --batch, but totally silent.
5110 --return-child-result The debugger will exist with the same value
5111 the child (debugged) program exited with.
5112 --eval-command COMMAND, -ex COMMAND
5113 Execute a single GDB CLI command. This may be
5114 specified multiple times and in conjunction
5115 with the --command (-x) option.
5117 * Deprecated commands removed
5119 The following commands, that were deprecated in 2000, have been
5123 set|show arm disassembly-flavor set|show arm disassembler
5124 othernames set arm disassembler
5125 set|show remotedebug set|show debug remote
5126 set|show archdebug set|show debug arch
5127 set|show eventdebug set|show debug event
5130 * New BSD user-level threads support
5132 It is now possible to debug programs using the user-level threads
5133 library on OpenBSD and FreeBSD. Currently supported (target)
5136 FreeBSD/amd64 x86_64-*-freebsd*
5137 FreeBSD/i386 i386-*-freebsd*
5138 OpenBSD/i386 i386-*-openbsd*
5140 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5141 are not yet supported.
5143 * New support for Matsushita MN10300 w/sim added
5144 (Work in progress). mn10300-elf.
5146 * REMOVED configurations and files
5148 VxWorks and the XDR protocol *-*-vxworks
5149 Motorola MCORE mcore-*-*
5150 National Semiconductor NS32000 ns32k-*-*
5152 * New "set print array-indexes" command
5154 After turning this setting "on", GDB prints the index of each element
5155 when displaying arrays. The default is "off" to preserve the previous
5158 * VAX floating point support
5160 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5162 * User-defined command support
5164 In addition to using $arg0..$arg9 for argument passing, it is now possible
5165 to use $argc to determine now many arguments have been passed. See the
5166 section on user-defined commands in the user manual for more information.
5168 *** Changes in GDB 6.3:
5170 * New command line option
5172 GDB now accepts -l followed by a number to set the timeout for remote
5175 * GDB works with GCC -feliminate-dwarf2-dups
5177 GDB now supports a more compact representation of DWARF-2 debug
5178 information using DW_FORM_ref_addr references. These are produced
5179 by GCC with the option -feliminate-dwarf2-dups and also by some
5180 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5181 to use -feliminate-dwarf2-dups.
5183 * Internationalization
5185 When supported by the host system, GDB will be built with
5186 internationalization (libintl). The task of marking up the sources is
5187 continued, we're looking forward to our first translation.
5191 Initial support for debugging programs compiled with the GNAT
5192 implementation of the Ada programming language has been integrated
5193 into GDB. In this release, support is limited to expression evaluation.
5195 * New native configurations
5197 GNU/Linux/m32r m32r-*-linux-gnu
5201 GDB's remote protocol now includes support for the 'p' packet. This
5202 packet is used to fetch individual registers from a remote inferior.
5204 * END-OF-LIFE registers[] compatibility module
5206 GDB's internal register infrastructure has been completely rewritten.
5207 The new infrastructure making possible the implementation of key new
5208 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5211 GDB 6.3 will be the last release to include the registers[]
5212 compatibility module that allowed out-of-date configurations to
5213 continue to work. This change directly impacts the following
5223 powerpc bdm protocol
5225 Unless there is activity to revive these configurations, they will be
5226 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5228 * OBSOLETE configurations and files
5230 Configurations that have been declared obsolete in this release have
5231 been commented out. Unless there is activity to revive these
5232 configurations, the next release of GDB will have their sources
5233 permanently REMOVED.
5242 *** Changes in GDB 6.2.1:
5244 * MIPS `break main; run' gave an heuristic-fence-post warning
5246 When attempting to run even a simple program, a warning about
5247 heuristic-fence-post being hit would be reported. This problem has
5250 * MIPS IRIX 'long double' crashed GDB
5252 When examining a long double variable, GDB would get a segmentation
5253 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5254 IRIX long double values).
5258 A bug in the VAX stack code was causing problems with the "next"
5259 command. This problem has been fixed.
5261 *** Changes in GDB 6.2:
5263 * Fix for ``many threads''
5265 On GNU/Linux systems that use the NPTL threads library, a program
5266 rapidly creating and deleting threads would confuse GDB leading to the
5269 ptrace: No such process.
5270 thread_db_get_info: cannot get thread info: generic error
5272 This problem has been fixed.
5274 * "-async" and "-noasync" options removed.
5276 Support for the broken "-noasync" option has been removed (it caused
5279 * New ``start'' command.
5281 This command runs the program until the begining of the main procedure.
5283 * New BSD Kernel Data Access Library (libkvm) interface
5285 Using ``target kvm'' it is now possible to debug kernel core dumps and
5286 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5287 platforms. Currently supported (native-only) configurations are:
5289 FreeBSD/amd64 x86_64-*-freebsd*
5290 FreeBSD/i386 i?86-*-freebsd*
5291 NetBSD/i386 i?86-*-netbsd*
5292 NetBSD/m68k m68*-*-netbsd*
5293 NetBSD/sparc sparc-*-netbsd*
5294 OpenBSD/amd64 x86_64-*-openbsd*
5295 OpenBSD/i386 i?86-*-openbsd*
5296 OpenBSD/m68k m68*-openbsd*
5297 OpenBSD/sparc sparc-*-openbsd*
5299 * Signal trampoline code overhauled
5301 Many generic problems with GDB's signal handling code have been fixed.
5302 These include: backtraces through non-contiguous stacks; recognition
5303 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5304 call; backtrace through a signal trampoline; step into and out of
5305 signal handlers; and single-stepping in the signal trampoline.
5307 Please note that kernel bugs are a limiting factor here. These
5308 features have been shown to work on an s390 GNU/Linux system that
5309 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5311 * Cygwin support for DWARF 2 added.
5313 * New native configurations
5315 GNU/Linux/hppa hppa*-*-linux*
5316 OpenBSD/hppa hppa*-*-openbsd*
5317 OpenBSD/m68k m68*-*-openbsd*
5318 OpenBSD/m88k m88*-*-openbsd*
5319 OpenBSD/powerpc powerpc-*-openbsd*
5320 NetBSD/vax vax-*-netbsd*
5321 OpenBSD/vax vax-*-openbsd*
5323 * END-OF-LIFE frame compatibility module
5325 GDB's internal frame infrastructure has been completely rewritten.
5326 The new infrastructure making it possible to support key new features
5327 including DWARF 2 Call Frame Information. To aid in the task of
5328 migrating old configurations to this new infrastructure, a
5329 compatibility module, that allowed old configurations to continue to
5330 work, was also included.
5332 GDB 6.2 will be the last release to include this frame compatibility
5333 module. This change directly impacts the following configurations:
5343 Unless there is activity to revive these configurations, they will be
5344 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5346 * REMOVED configurations and files
5348 Sun 3, running SunOS 3 m68*-*-sunos3*
5349 Sun 3, running SunOS 4 m68*-*-sunos4*
5350 Sun 2, running SunOS 3 m68000-*-sunos3*
5351 Sun 2, running SunOS 4 m68000-*-sunos4*
5352 Motorola 680x0 running LynxOS m68*-*-lynxos*
5353 AT&T 3b1/Unix pc m68*-att-*
5354 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5355 decstation mips-dec-* mips-little-*
5356 riscos mips-*-riscos* mips-*-sysv*
5357 sonymips mips-sony-*
5358 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5360 *** Changes in GDB 6.1.1:
5362 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5364 The TUI (Text-mode User Interface) is now built as part of a default
5365 GDB configuration. It is enabled by either selecting the TUI with the
5366 command line option "-i=tui" or by running the separate "gdbtui"
5367 program. For more information on the TUI, see the manual "Debugging
5370 * Pending breakpoint support (also included in GDB 6.1)
5372 Support has been added to allow you to specify breakpoints in shared
5373 libraries that have not yet been loaded. If a breakpoint location
5374 cannot be found, and the "breakpoint pending" option is set to auto,
5375 GDB queries you if you wish to make the breakpoint pending on a future
5376 shared-library load. If and when GDB resolves the breakpoint symbol,
5377 the pending breakpoint is removed as one or more regular breakpoints
5380 Pending breakpoints are very useful for GCJ Java debugging.
5382 * Fixed ISO-C build problems
5384 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5385 non ISO-C code that stopped them being built using a more strict ISO-C
5386 compiler (e.g., IBM's C compiler).
5388 * Fixed build problem on IRIX 5
5390 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5391 wasn't able to compile compile on an IRIX 5 system.
5393 * Added execute permission to gdb/gdbserver/configure
5395 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5396 permission. This bug would cause configure to fail on a number of
5397 systems (Solaris, IRIX). Ref: server/519.
5399 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5401 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5402 has been updated to use constant array sizes.
5404 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5406 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5407 its generated DWARF Call Frame Info. This encoding was causing GDB to
5408 panic, that panic has been fixed. Ref: gdb/1628.
5410 * Fixed a problem when examining parameters in shared library code.
5412 When examining parameters in optimized shared library code generated
5413 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5414 not available''. GDB now correctly displays the variable's value.
5416 *** Changes in GDB 6.1:
5418 * Removed --with-mmalloc
5420 Support for the mmalloc memory manager has been removed, as it
5421 conflicted with the internal gdb byte cache.
5423 * Changes in AMD64 configurations
5425 The AMD64 target now includes the %cs and %ss registers. As a result
5426 the AMD64 remote protocol has changed; this affects the floating-point
5427 and SSE registers. If you rely on those registers for your debugging,
5428 you should upgrade gdbserver on the remote side.
5430 * Revised SPARC target
5432 The SPARC target has been completely revised, incorporating the
5433 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5434 support for LynxOS and SunOS 4 has been dropped. Calling functions
5435 from within GDB on operating systems with a non-executable stack
5436 (Solaris, OpenBSD) now works.
5440 GDB has a new C++ demangler which does a better job on the mangled
5441 names generated by current versions of g++. It also runs faster, so
5442 with this and other changes gdb should now start faster on large C++
5445 * DWARF 2 Location Expressions
5447 GDB support for location expressions has been extended to support function
5448 arguments and frame bases. Older versions of GDB could crash when they
5451 * C++ nested types and namespaces
5453 GDB's support for nested types and namespaces in C++ has been
5454 improved, especially if you use the DWARF 2 debugging format. (This
5455 is the default for recent versions of GCC on most platforms.)
5456 Specifically, if you have a class "Inner" defined within a class or
5457 namespace "Outer", then GDB realizes that the class's name is
5458 "Outer::Inner", not simply "Inner". This should greatly reduce the
5459 frequency of complaints about not finding RTTI symbols. In addition,
5460 if you are stopped at inside of a function defined within a namespace,
5461 GDB modifies its name lookup accordingly.
5463 * New native configurations
5465 NetBSD/amd64 x86_64-*-netbsd*
5466 OpenBSD/amd64 x86_64-*-openbsd*
5467 OpenBSD/alpha alpha*-*-openbsd*
5468 OpenBSD/sparc sparc-*-openbsd*
5469 OpenBSD/sparc64 sparc64-*-openbsd*
5471 * New debugging protocols
5473 M32R with SDI protocol m32r-*-elf*
5475 * "set prompt-escape-char" command deleted.
5477 The command "set prompt-escape-char" has been deleted. This command,
5478 and its very obscure effet on GDB's prompt, was never documented,
5479 tested, nor mentioned in the NEWS file.
5481 * OBSOLETE configurations and files
5483 Configurations that have been declared obsolete in this release have
5484 been commented out. Unless there is activity to revive these
5485 configurations, the next release of GDB will have their sources
5486 permanently REMOVED.
5488 Sun 3, running SunOS 3 m68*-*-sunos3*
5489 Sun 3, running SunOS 4 m68*-*-sunos4*
5490 Sun 2, running SunOS 3 m68000-*-sunos3*
5491 Sun 2, running SunOS 4 m68000-*-sunos4*
5492 Motorola 680x0 running LynxOS m68*-*-lynxos*
5493 AT&T 3b1/Unix pc m68*-att-*
5494 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5495 decstation mips-dec-* mips-little-*
5496 riscos mips-*-riscos* mips-*-sysv*
5497 sonymips mips-sony-*
5498 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5500 * REMOVED configurations and files
5502 SGI Irix-4.x mips-sgi-irix4 or iris4
5503 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5504 Z8000 simulator z8k-zilog-none or z8ksim
5505 Matsushita MN10200 w/simulator mn10200-*-*
5506 H8/500 simulator h8500-hitachi-hms or h8500hms
5507 HP/PA running BSD hppa*-*-bsd*
5508 HP/PA running OSF/1 hppa*-*-osf*
5509 HP/PA Pro target hppa*-*-pro*
5510 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5511 386BSD i[3456]86-*-bsd*
5512 Sequent family i[3456]86-sequent-sysv4*
5513 i[3456]86-sequent-sysv*
5514 i[3456]86-sequent-bsd*
5515 SPARC running LynxOS sparc-*-lynxos*
5516 SPARC running SunOS 4 sparc-*-sunos4*
5517 Tsqware Sparclet sparclet-*-*
5518 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5520 *** Changes in GDB 6.0:
5524 Support for debugging the Objective-C programming language has been
5525 integrated into GDB.
5527 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5529 DWARF 2's Call Frame Information makes available compiler generated
5530 information that more exactly describes the program's run-time stack.
5531 By using this information, GDB is able to provide more robust stack
5534 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5535 have been updated to use a new backtrace mechanism which includes
5536 DWARF 2 CFI support.
5540 GDB's remote protocol has been extended to include support for hosted
5541 file I/O (where the remote target uses GDB's file system). See GDB's
5542 remote protocol documentation for details.
5544 * All targets using the new architecture framework.
5546 All of GDB's targets have been updated to use the new internal
5547 architecture framework. The way is now open for future GDB releases
5548 to include cross-architecture native debugging support (i386 on amd64,
5551 * GNU/Linux's Thread Local Storage (TLS)
5553 GDB now includes support for for the GNU/Linux implementation of
5554 per-thread variables.
5556 * GNU/Linux's Native POSIX Thread Library (NPTL)
5558 GDB's thread code has been updated to work with either the new
5559 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5561 * Separate debug info.
5563 GDB, in conjunction with BINUTILS, now supports a mechanism for
5564 automatically loading debug information from a separate file. Instead
5565 of shipping full debug and non-debug versions of system libraries,
5566 system integrators can now instead ship just the stripped libraries
5567 and optional debug files.
5569 * DWARF 2 Location Expressions
5571 DWARF 2 Location Expressions allow the compiler to more completely
5572 describe the location of variables (even in optimized code) to the
5575 GDB now includes preliminary support for location expressions (support
5576 for DW_OP_piece is still missing).
5580 A number of long standing bugs that caused GDB to die while starting a
5581 Java application have been fixed. GDB's Java support is now
5582 considered "useable".
5584 * GNU/Linux support for fork, vfork, and exec.
5586 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5587 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5590 * GDB supports logging output to a file
5592 There are two new commands, "set logging" and "show logging", which can be
5593 used to capture GDB's output to a file.
5595 * The meaning of "detach" has changed for gdbserver
5597 The "detach" command will now resume the application, as documented. To
5598 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5601 * d10v, m68hc11 `regs' command deprecated
5603 The `info registers' command has been updated so that it displays the
5604 registers using a format identical to the old `regs' command.
5608 A new command, "maint set profile on/off", has been added. This command can
5609 be used to enable or disable profiling while running GDB, to profile a
5610 session or a set of commands. In addition there is a new configure switch,
5611 "--enable-profiling", which will cause GDB to be compiled with profiling
5612 data, for more informative profiling results.
5614 * Default MI syntax changed to "mi2".
5616 The default MI (machine interface) syntax, enabled by the command line
5617 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5618 "mi1", can be enabled by specifying the option "-i=mi1".
5620 Support for the original "mi0" syntax (included in GDB 5.0) has been
5623 Fix for gdb/192: removed extraneous space when displaying frame level.
5624 Fix for gdb/672: update changelist is now output in mi list format.
5625 Fix for gdb/702: a -var-assign that updates the value now shows up
5626 in a subsequent -var-update.
5628 * New native configurations.
5630 FreeBSD/amd64 x86_64-*-freebsd*
5632 * Multi-arched targets.
5634 HP/PA HPUX11 hppa*-*-hpux*
5635 Renesas M32R/D w/simulator m32r-*-elf*
5637 * OBSOLETE configurations and files
5639 Configurations that have been declared obsolete in this release have
5640 been commented out. Unless there is activity to revive these
5641 configurations, the next release of GDB will have their sources
5642 permanently REMOVED.
5644 Z8000 simulator z8k-zilog-none or z8ksim
5645 Matsushita MN10200 w/simulator mn10200-*-*
5646 H8/500 simulator h8500-hitachi-hms or h8500hms
5647 HP/PA running BSD hppa*-*-bsd*
5648 HP/PA running OSF/1 hppa*-*-osf*
5649 HP/PA Pro target hppa*-*-pro*
5650 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5651 Sequent family i[3456]86-sequent-sysv4*
5652 i[3456]86-sequent-sysv*
5653 i[3456]86-sequent-bsd*
5654 Tsqware Sparclet sparclet-*-*
5655 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5657 * REMOVED configurations and files
5660 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5661 IBM AIX PS/2 i[3456]86-*-aix
5662 i386 running Mach 3.0 i[3456]86-*-mach3*
5663 i386 running Mach i[3456]86-*-mach*
5664 i386 running OSF/1 i[3456]86-*osf1mk*
5665 HP/Apollo 68k Family m68*-apollo*-sysv*,
5667 m68*-hp-bsd*, m68*-hp-hpux*
5668 Argonaut Risc Chip (ARC) arc-*-*
5669 Mitsubishi D30V d30v-*-*
5670 Fujitsu FR30 fr30-*-elf*
5671 OS/9000 i[34]86-*-os9k
5672 I960 with MON960 i960-*-coff
5674 * MIPS $fp behavior changed
5676 The convenience variable $fp, for the MIPS, now consistently returns
5677 the address of the current frame's base. Previously, depending on the
5678 context, $fp could refer to either $sp or the current frame's base
5679 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5680 The GNU Source-Level Debugger''.
5682 *** Changes in GDB 5.3:
5684 * GNU/Linux shared library multi-threaded performance improved.
5686 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5687 `/proc', in preference to `ptrace' for memory reads. This may result
5688 in an improvement in the start-up time of multi-threaded, shared
5689 library applications when run under GDB. One GDB user writes: ``loads
5690 shared libs like mad''.
5692 * ``gdbserver'' now supports multi-threaded applications on some targets
5694 Support for debugging multi-threaded applications which use
5695 the GNU/Linux LinuxThreads package has been added for
5696 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5697 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5699 * GDB now supports C/C++ preprocessor macros.
5701 GDB now expands preprocessor macro invocations in C/C++ expressions,
5702 and provides various commands for showing macro definitions and how
5705 The new command `macro expand EXPRESSION' expands any macro
5706 invocations in expression, and shows the result.
5708 The new command `show macro MACRO-NAME' shows the definition of the
5709 macro named MACRO-NAME, and where it was defined.
5711 Most compilers don't include information about macros in the debugging
5712 information by default. In GCC 3.1, for example, you need to compile
5713 your program with the options `-gdwarf-2 -g3'. If the macro
5714 information is present in the executable, GDB will read it.
5716 * Multi-arched targets.
5718 DEC Alpha (partial) alpha*-*-*
5719 DEC VAX (partial) vax-*-*
5721 National Semiconductor NS32000 (partial) ns32k-*-*
5722 Motorola 68000 (partial) m68k-*-*
5723 Motorola MCORE mcore-*-*
5727 Fujitsu FRV architecture added by Red Hat frv*-*-*
5730 * New native configurations
5732 Alpha NetBSD alpha*-*-netbsd*
5733 SH NetBSD sh*-*-netbsdelf*
5734 MIPS NetBSD mips*-*-netbsd*
5735 UltraSPARC NetBSD sparc64-*-netbsd*
5737 * OBSOLETE configurations and files
5739 Configurations that have been declared obsolete in this release have
5740 been commented out. Unless there is activity to revive these
5741 configurations, the next release of GDB will have their sources
5742 permanently REMOVED.
5744 Mitsubishi D30V d30v-*-*
5745 OS/9000 i[34]86-*-os9k
5746 IBM AIX PS/2 i[3456]86-*-aix
5747 Fujitsu FR30 fr30-*-elf*
5748 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5749 Argonaut Risc Chip (ARC) arc-*-*
5750 i386 running Mach 3.0 i[3456]86-*-mach3*
5751 i386 running Mach i[3456]86-*-mach*
5752 i386 running OSF/1 i[3456]86-*osf1mk*
5753 HP/Apollo 68k Family m68*-apollo*-sysv*,
5755 m68*-hp-bsd*, m68*-hp-hpux*
5756 I960 with MON960 i960-*-coff
5758 * OBSOLETE languages
5760 CHILL, a Pascal like language used by telecommunications companies.
5762 * REMOVED configurations and files
5764 AMD 29k family via UDI a29k-amd-udi, udi29k
5765 A29K VxWorks a29k-*-vxworks
5766 AMD 29000 embedded, using EBMON a29k-none-none
5767 AMD 29000 embedded with COFF a29k-none-coff
5768 AMD 29000 embedded with a.out a29k-none-aout
5770 testsuite/gdb.hp/gdb.threads-hp/ directory
5772 * New command "set max-user-call-depth <nnn>"
5774 This command allows the user to limit the call depth of user-defined
5775 commands. The default is 1024.
5777 * Changes in FreeBSD/i386 native debugging.
5779 Support for the "generate-core-file" has been added.
5781 * New commands "dump", "append", and "restore".
5783 These commands allow data to be copied from target memory
5784 to a bfd-format or binary file (dump and append), and back
5785 from a file into memory (restore).
5787 * Improved "next/step" support on multi-processor Alpha Tru64.
5789 The previous single-step mechanism could cause unpredictable problems,
5790 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5791 of a software single-step mechanism prevents this.
5793 *** Changes in GDB 5.2.1:
5801 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5802 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5803 Fix, by Joel Brobecker imported from mainline.
5805 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5806 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5807 Fix, by Fred Fish, imported from mainline.
5809 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5810 Surprisingly enough, it works now.
5811 By Michal Ludvig, imported from mainline.
5813 i386 hardware watchpoint support:
5814 avoid misses on second run for some targets.
5815 By Pierre Muller, imported from mainline.
5817 *** Changes in GDB 5.2:
5819 * New command "set trust-readonly-sections on[off]".
5821 This command is a hint that tells gdb that read-only sections
5822 really are read-only (ie. that their contents will not change).
5823 In this mode, gdb will go to the object file rather than the
5824 target to read memory from read-only sections (such as ".text").
5825 This can be a significant performance improvement on some
5826 (notably embedded) targets.
5828 * New command "generate-core-file" (or "gcore").
5830 This new gdb command allows the user to drop a core file of the child
5831 process state at any time. So far it's been implemented only for
5832 GNU/Linux and Solaris, but should be relatively easily ported to other
5833 hosts. Argument is core file name (defaults to core.<pid>).
5835 * New command line option
5837 GDB now accepts --pid or -p followed by a process id.
5839 * Change in command line behavior -- corefiles vs. process ids.
5841 There is a subtle behavior in the way in which GDB handles
5842 command line arguments. The first non-flag argument is always
5843 a program to debug, but the second non-flag argument may either
5844 be a corefile or a process id. Previously, GDB would attempt to
5845 open the second argument as a corefile, and if that failed, would
5846 issue a superfluous error message and then attempt to attach it as
5847 a process. Now, if the second argument begins with a non-digit,
5848 it will be treated as a corefile. If it begins with a digit,
5849 GDB will attempt to attach it as a process, and if no such process
5850 is found, will then attempt to open it as a corefile.
5852 * Changes in ARM configurations.
5854 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5855 configuration is fully multi-arch.
5857 * New native configurations
5859 ARM NetBSD arm*-*-netbsd*
5860 x86 OpenBSD i[3456]86-*-openbsd*
5861 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5862 Sparc64 running FreeBSD sparc64-*-freebsd*
5866 Sanyo XStormy16 xstormy16-elf
5868 * OBSOLETE configurations and files
5870 Configurations that have been declared obsolete in this release have
5871 been commented out. Unless there is activity to revive these
5872 configurations, the next release of GDB will have their sources
5873 permanently REMOVED.
5875 AMD 29k family via UDI a29k-amd-udi, udi29k
5876 A29K VxWorks a29k-*-vxworks
5877 AMD 29000 embedded, using EBMON a29k-none-none
5878 AMD 29000 embedded with COFF a29k-none-coff
5879 AMD 29000 embedded with a.out a29k-none-aout
5881 testsuite/gdb.hp/gdb.threads-hp/ directory
5883 * REMOVED configurations and files
5885 TI TMS320C80 tic80-*-*
5887 PowerPC Solaris powerpcle-*-solaris*
5888 PowerPC Windows NT powerpcle-*-cygwin32
5889 PowerPC Netware powerpc-*-netware*
5890 Harris/CXUX m88k m88*-harris-cxux*
5891 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5892 ns32k-utek-sysv* ns32k-utek-*
5893 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5894 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5895 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5896 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5897 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5899 * Changes to command line processing
5901 The new `--args' feature can be used to specify command-line arguments
5902 for the inferior from gdb's command line.
5904 * Changes to key bindings
5906 There is a new `operate-and-get-next' function bound to `C-o'.
5908 *** Changes in GDB 5.1.1
5910 Fix compile problem on DJGPP.
5912 Fix a problem with floating-point registers on the i386 being
5915 Fix to stop GDB crashing on .debug_str debug info.
5917 Numerous documentation fixes.
5919 Numerous testsuite fixes.
5921 *** Changes in GDB 5.1:
5923 * New native configurations
5925 Alpha FreeBSD alpha*-*-freebsd*
5926 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5927 MIPS GNU/Linux mips*-*-linux*
5928 MIPS SGI Irix 6.x mips*-sgi-irix6*
5929 ia64 AIX ia64-*-aix*
5930 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5934 Motorola 68HC11 and 68HC12 m68hc11-elf
5936 UltraSparc running GNU/Linux sparc64-*-linux*
5938 * OBSOLETE configurations and files
5940 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5941 Harris/CXUX m88k m88*-harris-cxux*
5942 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5943 ns32k-utek-sysv* ns32k-utek-*
5944 TI TMS320C80 tic80-*-*
5946 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5947 PowerPC Solaris powerpcle-*-solaris*
5948 PowerPC Windows NT powerpcle-*-cygwin32
5949 PowerPC Netware powerpc-*-netware*
5950 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5951 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5952 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5953 Apple Macintosh (MPW) host N/A
5955 stuff.c (Program to stuff files into a specially prepared space in kdb)
5956 kdb-start.c (Main loop for the standalone kernel debugger)
5958 Configurations that have been declared obsolete in this release have
5959 been commented out. Unless there is activity to revive these
5960 configurations, the next release of GDB will have their sources
5961 permanently REMOVED.
5963 * REMOVED configurations and files
5965 Altos 3068 m68*-altos-*
5966 Convex c1-*-*, c2-*-*
5968 ARM RISCix arm-*-* (as host)
5972 * GDB has been converted to ISO C.
5974 GDB's source code has been converted to ISO C. In particular, the
5975 sources are fully protoized, and rely on standard headers being
5980 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5982 * The MI enabled by default.
5984 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5985 revised and enabled by default. Packages which use GDB as a debugging
5986 engine behind a UI or another front end are encouraged to switch to
5987 using the GDB/MI interface, instead of the old annotations interface
5988 which is now deprecated.
5990 * Support for debugging Pascal programs.
5992 GDB now includes support for debugging Pascal programs. The following
5993 main features are supported:
5995 - Pascal-specific data types such as sets;
5997 - automatic recognition of Pascal sources based on file-name
6000 - Pascal-style display of data types, variables, and functions;
6002 - a Pascal expression parser.
6004 However, some important features are not yet supported.
6006 - Pascal string operations are not supported at all;
6008 - there are some problems with boolean types;
6010 - Pascal type hexadecimal constants are not supported
6011 because they conflict with the internal variables format;
6013 - support for Pascal objects and classes is not full yet;
6015 - unlike Pascal, GDB is case-sensitive for symbol names.
6017 * Changes in completion.
6019 Commands such as `shell', `run' and `set args', which pass arguments
6020 to inferior programs, now complete on file names, similar to what
6021 users expect at the shell prompt.
6023 Commands which accept locations, such as `disassemble', `print',
6024 `breakpoint', `until', etc. now complete on filenames as well as
6025 program symbols. Thus, if you type "break foob TAB", and the source
6026 files linked into the programs include `foobar.c', that file name will
6027 be one of the candidates for completion. However, file names are not
6028 considered for completion after you typed a colon that delimits a file
6029 name from a name of a function in that file, as in "break foo.c:bar".
6031 `set demangle-style' completes on available demangling styles.
6033 * New platform-independent commands:
6035 It is now possible to define a post-hook for a command as well as a
6036 hook that runs before the command. For more details, see the
6037 documentation of `hookpost' in the GDB manual.
6039 * Changes in GNU/Linux native debugging.
6041 Support for debugging multi-threaded programs has been completely
6042 revised for all platforms except m68k and sparc. You can now debug as
6043 many threads as your system allows you to have.
6045 Attach/detach is supported for multi-threaded programs.
6047 Support for SSE registers was added for x86. This doesn't work for
6048 multi-threaded programs though.
6050 * Changes in MIPS configurations.
6052 Multi-arch support is enabled for all MIPS configurations.
6054 GDB can now be built as native debugger on SGI Irix 6.x systems for
6055 debugging n32 executables. (Debugging 64-bit executables is not yet
6058 * Unified support for hardware watchpoints in all x86 configurations.
6060 Most (if not all) native x86 configurations support hardware-assisted
6061 breakpoints and watchpoints in a unified manner. This support
6062 implements debug register sharing between watchpoints, which allows to
6063 put a virtually infinite number of watchpoints on the same address,
6064 and also supports watching regions up to 16 bytes with several debug
6067 The new maintenance command `maintenance show-debug-regs' toggles
6068 debugging print-outs in functions that insert, remove, and test
6069 watchpoints and hardware breakpoints.
6071 * Changes in the DJGPP native configuration.
6073 New command ``info dos sysinfo'' displays assorted information about
6074 the CPU, OS, memory, and DPMI server.
6076 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6077 display information about segment descriptors stored in GDT, LDT, and
6080 New commands ``info dos pde'' and ``info dos pte'' display entries
6081 from Page Directory and Page Tables (for now works with CWSDPMI only).
6082 New command ``info dos address-pte'' displays the Page Table entry for
6083 a given linear address.
6085 GDB can now pass command lines longer than 126 characters to the
6086 program being debugged (requires an update to the libdbg.a library
6087 which is part of the DJGPP development kit).
6089 DWARF2 debug info is now supported.
6091 It is now possible to `step' and `next' through calls to `longjmp'.
6093 * Changes in documentation.
6095 All GDB documentation was converted to GFDL, the GNU Free
6096 Documentation License.
6098 Tracepoints-related commands are now fully documented in the GDB
6101 TUI, the Text-mode User Interface, is now documented in the manual.
6103 Tracepoints-related commands are now fully documented in the GDB
6106 The "GDB Internals" manual now has an index. It also includes
6107 documentation of `ui_out' functions, GDB coding standards, x86
6108 hardware watchpoints, and memory region attributes.
6110 * GDB's version number moved to ``version.in''
6112 The Makefile variable VERSION has been replaced by the file
6113 ``version.in''. People creating GDB distributions should update the
6114 contents of this file.
6118 GUD support is now a standard part of the EMACS distribution.
6120 *** Changes in GDB 5.0:
6122 * Improved support for debugging FP programs on x86 targets
6124 Unified and much-improved support for debugging floating-point
6125 programs on all x86 targets. In particular, ``info float'' now
6126 displays the FP registers in the same format on all x86 targets, with
6127 greater level of detail.
6129 * Improvements and bugfixes in hardware-assisted watchpoints
6131 It is now possible to watch array elements, struct members, and
6132 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6133 on x86 targets no longer erroneously trigger when the address is
6136 * Improvements in the native DJGPP version of GDB
6138 The distribution now includes all the scripts and auxiliary files
6139 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6140 machines ``out of the box''.
6142 The DJGPP version can now debug programs that use signals. It is
6143 possible to catch signals that happened in the debuggee, deliver
6144 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6145 would kill the program being debugged.) Programs that hook hardware
6146 interrupts (keyboard, timer, etc.) can also be debugged.
6148 It is now possible to debug DJGPP programs that redirect their
6149 standard handles or switch them to raw (as opposed to cooked) mode, or
6150 even close them. The command ``run < foo > bar'' works as expected,
6151 and ``info terminal'' reports useful information about the debuggee's
6152 terminal, including raw/cooked mode, redirection, etc.
6154 The DJGPP version now uses termios functions for console I/O, which
6155 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6158 DOS-style file names with drive letters are now fully supported by
6161 It is now possible to debug DJGPP programs that switch their working
6162 directory. It is also possible to rerun the debuggee any number of
6163 times without restarting GDB; thus, you can use the same setup,
6164 breakpoints, etc. for many debugging sessions.
6166 * New native configurations
6168 ARM GNU/Linux arm*-*-linux*
6169 PowerPC GNU/Linux powerpc-*-linux*
6173 Motorola MCore mcore-*-*
6174 x86 VxWorks i[3456]86-*-vxworks*
6175 PowerPC VxWorks powerpc-*-vxworks*
6176 TI TMS320C80 tic80-*-*
6178 * OBSOLETE configurations
6180 Altos 3068 m68*-altos-*
6181 Convex c1-*-*, c2-*-*
6183 ARM RISCix arm-*-* (as host)
6186 Configurations that have been declared obsolete will be commented out,
6187 but the code will be left in place. If there is no activity to revive
6188 these configurations before the next release of GDB, the sources will
6189 be permanently REMOVED.
6191 * Gould support removed
6193 Support for the Gould PowerNode and NP1 has been removed.
6195 * New features for SVR4
6197 On SVR4 native platforms (such as Solaris), if you attach to a process
6198 without first loading a symbol file, GDB will now attempt to locate and
6199 load symbols from the running process's executable file.
6201 * Many C++ enhancements
6203 C++ support has been greatly improved. Overload resolution now works properly
6204 in almost all cases. RTTI support is on the way.
6206 * Remote targets can connect to a sub-program
6208 A popen(3) style serial-device has been added. This device starts a
6209 sub-process (such as a stand-alone simulator) and then communicates
6210 with that. The sub-program to run is specified using the syntax
6211 ``|<program> <args>'' vis:
6213 (gdb) set remotedebug 1
6214 (gdb) target extended-remote |mn10300-elf-sim program-args
6216 * MIPS 64 remote protocol
6218 A long standing bug in the mips64 remote protocol where by GDB
6219 expected certain 32 bit registers (ex SR) to be transfered as 32
6220 instead of 64 bits has been fixed.
6222 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6223 added to provide backward compatibility with older versions of GDB.
6225 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6227 The command ``set remotebinarydownload'' command has been replaced by
6228 ``set remote X-packet''. Other commands in ``set remote'' family
6229 include ``set remote P-packet''.
6231 * Breakpoint commands accept ranges.
6233 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6234 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6235 ``tracepoint passcount'' also accepts a range of tracepoints.
6237 * ``apropos'' command added.
6239 The ``apropos'' command searches through command names and
6240 documentation strings, printing out matches, making it much easier to
6241 try to find a command that does what you are looking for.
6245 A new machine oriented interface (MI) has been added to GDB. This
6246 interface is designed for debug environments running GDB as a separate
6247 process. This is part of the long term libGDB project. See the
6248 "GDB/MI" chapter of the GDB manual for further information. It can be
6249 enabled by configuring with:
6251 .../configure --enable-gdbmi
6253 *** Changes in GDB-4.18:
6255 * New native configurations
6257 HP-UX 10.20 hppa*-*-hpux10.20
6258 HP-UX 11.x hppa*-*-hpux11.0*
6259 M68K GNU/Linux m68*-*-linux*
6263 Fujitsu FR30 fr30-*-elf*
6264 Intel StrongARM strongarm-*-*
6265 Mitsubishi D30V d30v-*-*
6267 * OBSOLETE configurations
6269 Gould PowerNode, NP1 np1-*-*, pn-*-*
6271 Configurations that have been declared obsolete will be commented out,
6272 but the code will be left in place. If there is no activity to revive
6273 these configurations before the next release of GDB, the sources will
6274 be permanently REMOVED.
6278 As a compatibility experiment, GDB's source files buildsym.h and
6279 buildsym.c have been converted to pure standard C, no longer
6280 containing any K&R compatibility code. We believe that all systems in
6281 use today either come with a standard C compiler, or have a GCC port
6282 available. If this is not true, please report the affected
6283 configuration to bug-gdb@gnu.org immediately. See the README file for
6284 information about getting a standard C compiler if you don't have one
6289 GDB now uses readline 2.2.
6291 * set extension-language
6293 You can now control the mapping between filename extensions and source
6294 languages by using the `set extension-language' command. For instance,
6295 you can ask GDB to treat .c files as C++ by saying
6296 set extension-language .c c++
6297 The command `info extensions' lists all of the recognized extensions
6298 and their associated languages.
6300 * Setting processor type for PowerPC and RS/6000
6302 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6303 you can use the `set processor' command to specify what variant of the
6304 PowerPC family you are debugging. The command
6308 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6309 following PowerPC and RS6000 variants:
6311 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6312 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6314 403GC IBM PowerPC 403GC
6315 505 Motorola PowerPC 505
6316 860 Motorola PowerPC 860 or 850
6317 601 Motorola PowerPC 601
6318 602 Motorola PowerPC 602
6319 603 Motorola/IBM PowerPC 603 or 603e
6320 604 Motorola PowerPC 604 or 604e
6321 750 Motorola/IBM PowerPC 750 or 750
6323 At the moment, this command just tells GDB what to name the
6324 special-purpose processor registers. Since almost all the affected
6325 registers are inaccessible to user-level programs, this command is
6326 only useful for remote debugging in its present form.
6330 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6331 more extensive support for HP-UX. Added features include shared
6332 library support, kernel threads and hardware watchpoints for 11.00,
6333 support for HP's ANSI C and C++ compilers, and a compatibility mode
6334 for xdb and dbx commands.
6338 HP's donation includes the new concept of catchpoints, which is a
6339 generalization of the old catch command. On HP-UX, it is now possible
6340 to catch exec, fork, and vfork, as well as library loading.
6342 This means that the existing catch command has changed; its first
6343 argument now specifies the type of catch to be set up. See the
6344 output of "help catch" for a list of catchpoint types.
6346 * Debugging across forks
6348 On HP-UX, you can choose which process to debug when a fork() happens
6353 HP has donated a curses-based terminal user interface (TUI). To get
6354 it, build with --enable-tui. Although this can be enabled for any
6355 configuration, at present it only works for native HP debugging.
6357 * GDB remote protocol additions
6359 A new protocol packet 'X' that writes binary data is now available.
6360 Default behavior is to try 'X', then drop back to 'M' if the stub
6361 fails to respond. The settable variable `remotebinarydownload'
6362 allows explicit control over the use of 'X'.
6364 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6365 full 64-bit address. The command
6367 set remoteaddresssize 32
6369 can be used to revert to the old behaviour. For existing remote stubs
6370 the change should not be noticed, as the additional address information
6373 In order to assist in debugging stubs, you may use the maintenance
6374 command `packet' to send any text string to the stub. For instance,
6376 maint packet heythere
6378 sends the packet "$heythere#<checksum>". Note that it is very easy to
6379 disrupt a debugging session by sending the wrong packet at the wrong
6382 The compare-sections command allows you to compare section data on the
6383 target to what is in the executable file without uploading or
6384 downloading, by comparing CRC checksums.
6386 * Tracing can collect general expressions
6388 You may now collect general expressions at tracepoints. This requires
6389 further additions to the target-side stub; see tracepoint.c and
6390 doc/agentexpr.texi for further details.
6392 * mask-address variable for Mips
6394 For Mips targets, you may control the zeroing of the upper 32 bits of
6395 a 64-bit address by entering `set mask-address on'. This is mainly
6396 of interest to users of embedded R4xxx and R5xxx processors.
6398 * Higher serial baud rates
6400 GDB's serial code now allows you to specify baud rates 57600, 115200,
6401 230400, and 460800 baud. (Note that your host system may not be able
6402 to achieve all of these rates.)
6406 The i960 configuration now includes an initial implementation of a
6407 builtin simulator, contributed by Jim Wilson.
6410 *** Changes in GDB-4.17:
6412 * New native configurations
6414 Alpha GNU/Linux alpha*-*-linux*
6415 Unixware 2.x i[3456]86-unixware2*
6416 Irix 6.x mips*-sgi-irix6*
6417 PowerPC GNU/Linux powerpc-*-linux*
6418 PowerPC Solaris powerpcle-*-solaris*
6419 Sparc GNU/Linux sparc-*-linux*
6420 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6424 Argonaut Risc Chip (ARC) arc-*-*
6425 Hitachi H8/300S h8300*-*-*
6426 Matsushita MN10200 w/simulator mn10200-*-*
6427 Matsushita MN10300 w/simulator mn10300-*-*
6428 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6429 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6430 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6431 Mitsubishi D10V w/simulator d10v-*-*
6432 Mitsubishi M32R/D w/simulator m32r-*-elf*
6433 Tsqware Sparclet sparclet-*-*
6434 NEC V850 w/simulator v850-*-*
6436 * New debugging protocols
6438 ARM with RDI protocol arm*-*-*
6439 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6440 DDB and LSI variants of PMON protocol mips*-*-*
6441 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6442 PowerPC with SDS protocol powerpc{,le}-*-eabi
6443 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6447 All configurations can now understand and use the DWARF 2 debugging
6448 format. The choice is automatic, if the symbol file contains DWARF 2
6453 GDB now includes basic Java language support. This support is
6454 only useful with Java compilers that produce native machine code.
6456 * solib-absolute-prefix and solib-search-path
6458 For SunOS and SVR4 shared libraries, you may now set the prefix for
6459 loading absolute shared library symbol files, and the search path for
6460 locating non-absolute shared library symbol files.
6462 * Live range splitting
6464 GDB can now effectively debug code for which GCC has performed live
6465 range splitting as part of its optimization. See gdb/doc/LRS for
6466 more details on the expected format of the stabs information.
6470 GDB's support for the GNU Hurd, including thread debugging, has been
6471 updated to work with current versions of the Hurd.
6475 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6476 instruction set. ARM GDB automatically detects when Thumb
6477 instructions are in use, and adjusts disassembly and backtracing
6482 GDB's MIPS target configurations now handle the MIP16 16-bit
6487 GDB now includes support for overlays; if an executable has been
6488 linked such that multiple sections are based at the same address, GDB
6489 will decide which section to use for symbolic info. You can choose to
6490 control the decision manually, using overlay commands, or implement
6491 additional target-side support and use "overlay load-target" to bring
6492 in the overlay mapping. Do "help overlay" for more detail.
6496 The command "info symbol <address>" displays information about
6497 the symbol at the specified address.
6501 The standard remote protocol now includes an extension that allows
6502 asynchronous collection and display of trace data. This requires
6503 extensive support in the target-side debugging stub. Tracing mode
6504 includes a new interaction mode in GDB and new commands: see the
6505 file tracepoint.c for more details.
6509 Configurations for embedded MIPS now include a simulator contributed
6510 by Cygnus Solutions. The simulator supports the instruction sets
6511 of most MIPS variants.
6515 Sparc configurations may now include the ERC32 simulator contributed
6516 by the European Space Agency. The simulator is not built into
6517 Sparc targets by default; configure with --enable-sim to include it.
6521 For target configurations that may include multiple variants of a
6522 basic architecture (such as MIPS and SH), you may now set the
6523 architecture explicitly. "set arch" sets, "info arch" lists
6524 the possible architectures.
6526 *** Changes in GDB-4.16:
6528 * New native configurations
6530 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6531 M68K NetBSD m68k-*-netbsd*
6532 PowerPC AIX 4.x powerpc-*-aix*
6533 PowerPC MacOS powerpc-*-macos*
6534 PowerPC Windows NT powerpcle-*-cygwin32
6535 RS/6000 AIX 4.x rs6000-*-aix4*
6539 ARM with RDP protocol arm-*-*
6540 I960 with MON960 i960-*-coff
6541 MIPS VxWorks mips*-*-vxworks*
6542 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6543 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6545 Matra Sparclet sparclet-*-*
6549 The powerpc-eabi configuration now includes the PSIM simulator,
6550 contributed by Andrew Cagney, with assistance from Mike Meissner.
6551 PSIM is a very elaborate model of the PowerPC, including not only
6552 basic instruction set execution, but also details of execution unit
6553 performance and I/O hardware. See sim/ppc/README for more details.
6557 GDB now works with Solaris 2.5.
6559 * Windows 95/NT native
6561 GDB will now work as a native debugger on Windows 95 and Windows NT.
6562 To build it from source, you must use the "gnu-win32" environment,
6563 which uses a DLL to emulate enough of Unix to run the GNU tools.
6564 Further information, binaries, and sources are available at
6565 ftp.cygnus.com, under pub/gnu-win32.
6567 * dont-repeat command
6569 If a user-defined command includes the command `dont-repeat', then the
6570 command will not be repeated if the user just types return. This is
6571 useful if the command is time-consuming to run, so that accidental
6572 extra keystrokes don't run the same command many times.
6574 * Send break instead of ^C
6576 The standard remote protocol now includes an option to send a break
6577 rather than a ^C to the target in order to interrupt it. By default,
6578 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6580 * Remote protocol timeout
6582 The standard remote protocol includes a new variable `remotetimeout'
6583 that allows you to set the number of seconds before GDB gives up trying
6584 to read from the target. The default value is 2.
6586 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6588 By default GDB will automatically keep track of objects as they are
6589 loaded and unloaded by the dynamic linker. By using the command `set
6590 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6591 when shared library events occur, thus allowing you to set breakpoints
6592 in shared libraries which are explicitly loaded by the inferior.
6594 Note this feature does not work on hpux8. On hpux9 you must link
6595 /usr/lib/end.o into your program. This feature should work
6596 automatically on hpux10.
6598 * Irix 5.x hardware watchpoint support
6600 Irix 5 configurations now support the use of hardware watchpoints.
6602 * Mips protocol "SYN garbage limit"
6604 When debugging a Mips target using the `target mips' protocol, you
6605 may set the number of characters that GDB will ignore by setting
6606 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6607 every character. The default value is 1050.
6609 * Recording and replaying remote debug sessions
6611 If you set `remotelogfile' to the name of a file, gdb will write to it
6612 a recording of a remote debug session. This recording may then be
6613 replayed back to gdb using "gdbreplay". See gdbserver/README for
6614 details. This is useful when you have a problem with GDB while doing
6615 remote debugging; you can make a recording of the session and send it
6616 to someone else, who can then recreate the problem.
6618 * Speedups for remote debugging
6620 GDB includes speedups for downloading and stepping MIPS systems using
6621 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6622 and more efficient S-record downloading.
6624 * Memory use reductions and statistics collection
6626 GDB now uses less memory and reports statistics about memory usage.
6627 Try the `maint print statistics' command, for example.
6629 *** Changes in GDB-4.15:
6631 * Psymtabs for XCOFF
6633 The symbol reader for AIX GDB now uses partial symbol tables. This
6634 can greatly improve startup time, especially for large executables.
6636 * Remote targets use caching
6638 Remote targets now use a data cache to speed up communication with the
6639 remote side. The data cache could lead to incorrect results because
6640 it doesn't know about volatile variables, thus making it impossible to
6641 debug targets which use memory mapped I/O devices. `set remotecache
6642 off' turns the data cache off.
6644 * Remote targets may have threads
6646 The standard remote protocol now includes support for multiple threads
6647 in the target system, using new protocol commands 'H' and 'T'. See
6648 gdb/remote.c for details.
6652 If GDB is configured with `--enable-netrom', then it will include
6653 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6654 acts as though it is a bank of ROM on the target board, but you can
6655 write into it over the network. GDB's support consists only of
6656 support for fast loading into the emulated ROM; to debug, you must use
6657 another protocol, such as standard remote protocol. The usual
6658 sequence is something like
6660 target nrom <netrom-hostname>
6662 target remote <netrom-hostname>:1235
6666 GDB now includes support for the Apple Macintosh, as a host only. It
6667 may be run as either an MPW tool or as a standalone application, and
6668 it can debug through the serial port. All the usual GDB commands are
6669 available, but to the target command, you must supply "serial" as the
6670 device type instead of "/dev/ttyXX". See mpw-README in the main
6671 directory for more information on how to build. The MPW configuration
6672 scripts */mpw-config.in support only a few targets, and only the
6673 mips-idt-ecoff target has been tested.
6677 GDB configuration now uses autoconf. This is not user-visible,
6678 but does simplify configuration and building.
6682 GDB now supports hpux10.
6684 *** Changes in GDB-4.14:
6686 * New native configurations
6688 x86 FreeBSD i[345]86-*-freebsd
6689 x86 NetBSD i[345]86-*-netbsd
6690 NS32k NetBSD ns32k-*-netbsd
6691 Sparc NetBSD sparc-*-netbsd
6695 A29K VxWorks a29k-*-vxworks
6696 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6697 CPU32 EST-300 emulator m68*-*-est*
6698 PowerPC ELF powerpc-*-elf
6701 * Alpha OSF/1 support for procfs
6703 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6704 possible to attach to running processes. As the mounting of the /proc
6705 filesystem is optional on the Alpha, GDB automatically determines
6706 the availability of /proc during startup. This can lead to problems
6707 if /proc is unmounted after GDB has been started.
6709 * Arguments to user-defined commands
6711 User commands may accept up to 10 arguments separated by whitespace.
6712 Arguments are accessed within the user command via $arg0..$arg9. A
6715 print $arg0 + $arg1 + $arg2
6717 To execute the command use:
6720 Defines the command "adder" which prints the sum of its three arguments.
6721 Note the arguments are text substitutions, so they may reference variables,
6722 use complex expressions, or even perform inferior function calls.
6724 * New `if' and `while' commands
6726 This makes it possible to write more sophisticated user-defined
6727 commands. Both commands take a single argument, which is the
6728 expression to evaluate, and must be followed by the commands to
6729 execute, one per line, if the expression is nonzero, the list being
6730 terminated by the word `end'. The `if' command list may include an
6731 `else' word, which causes the following commands to be executed only
6732 if the expression is zero.
6734 * Fortran source language mode
6736 GDB now includes partial support for Fortran 77. It will recognize
6737 Fortran programs and can evaluate a subset of Fortran expressions, but
6738 variables and functions may not be handled correctly. GDB will work
6739 with G77, but does not yet know much about symbols emitted by other
6742 * Better HPUX support
6744 Most debugging facilities now work on dynamic executables for HPPAs
6745 running hpux9 or later. You can attach to running dynamically linked
6746 processes, but by default the dynamic libraries will be read-only, so
6747 for instance you won't be able to put breakpoints in them. To change
6748 that behavior do the following before running the program:
6754 This will cause the libraries to be mapped private and read-write.
6755 To revert to the normal behavior, do this:
6761 You cannot set breakpoints or examine data in the library until after
6762 the library is loaded if the function/data symbols do not have
6765 GDB can now also read debug symbols produced by the HP C compiler on
6766 HPPAs (sorry, no C++, Fortran or 68k support).
6768 * Target byte order now dynamically selectable
6770 You can choose which byte order to use with a target system, via the
6771 commands "set endian big" and "set endian little", and you can see the
6772 current setting by using "show endian". You can also give the command
6773 "set endian auto", in which case GDB will use the byte order
6774 associated with the executable. Currently, only embedded MIPS
6775 configurations support dynamic selection of target byte order.
6777 * New DOS host serial code
6779 This version uses DPMI interrupts to handle buffered I/O, so you
6780 no longer need to run asynctsr when debugging boards connected to
6783 *** Changes in GDB-4.13:
6785 * New "complete" command
6787 This lists all the possible completions for the rest of the line, if it
6788 were to be given as a command itself. This is intended for use by emacs.
6790 * Trailing space optional in prompt
6792 "set prompt" no longer adds a space for you after the prompt you set. This
6793 allows you to set a prompt which ends in a space or one that does not.
6795 * Breakpoint hit counts
6797 "info break" now displays a count of the number of times the breakpoint
6798 has been hit. This is especially useful in conjunction with "ignore"; you
6799 can ignore a large number of breakpoint hits, look at the breakpoint info
6800 to see how many times the breakpoint was hit, then run again, ignoring one
6801 less than that number, and this will get you quickly to the last hit of
6804 * Ability to stop printing at NULL character
6806 "set print null-stop" will cause GDB to stop printing the characters of
6807 an array when the first NULL is encountered. This is useful when large
6808 arrays actually contain only short strings.
6810 * Shared library breakpoints
6812 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6813 breakpoints in shared libraries before the executable is run.
6815 * Hardware watchpoints
6817 There is a new hardware breakpoint for the watch command for sparclite
6818 targets. See gdb/sparclite/hw_breakpoint.note.
6820 Hardware watchpoints are also now supported under GNU/Linux.
6824 Annotations have been added. These are for use with graphical interfaces,
6825 and are still experimental. Currently only gdba.el uses these.
6827 * Improved Irix 5 support
6829 GDB now works properly with Irix 5.2.
6831 * Improved HPPA support
6833 GDB now works properly with the latest GCC and GAS.
6835 * New native configurations
6837 Sequent PTX4 i[34]86-sequent-ptx4
6838 HPPA running OSF/1 hppa*-*-osf*
6839 Atari TT running SVR4 m68*-*-sysv4*
6840 RS/6000 LynxOS rs6000-*-lynxos*
6844 OS/9000 i[34]86-*-os9k
6845 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6848 * Hitachi SH7000 and E7000-PC ICE support
6850 There is now support for communicating with the Hitachi E7000-PC ICE.
6851 This is available automatically when GDB is configured for the SH.
6855 As usual, a variety of small fixes and improvements, both generic
6856 and configuration-specific. See the ChangeLog for more detail.
6858 *** Changes in GDB-4.12:
6860 * Irix 5 is now supported
6864 GDB-4.12 on the HPPA has a number of changes which make it unable
6865 to debug the output from the currently released versions of GCC and
6866 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6867 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6868 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6871 *** Changes in GDB-4.11:
6873 * User visible changes:
6877 The "set remotedebug" option is now consistent between the mips remote
6878 target, remote targets using the gdb-specific protocol, UDI (AMD's
6879 debug protocol for the 29k) and the 88k bug monitor. It is now an
6880 integer specifying a debug level (normally 0 or 1, but 2 means more
6881 debugging info for the mips target).
6883 * DEC Alpha native support
6885 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6886 debug info, but GDB works fairly well with the DEC compiler and should
6887 work with a future GCC release. See the README file for a few
6888 Alpha-specific notes.
6890 * Preliminary thread implementation
6892 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6894 * LynxOS native and target support for 386
6896 This release has been hosted on LynxOS 2.2, and also can be configured
6897 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6900 * Improvements in C++ mangling/demangling.
6902 This release has much better g++ debugging, specifically in name
6903 mangling/demangling, virtual function calls, print virtual table,
6904 call methods, ...etc.
6906 *** Changes in GDB-4.10:
6908 * User visible changes:
6910 Remote debugging using the GDB-specific (`target remote') protocol now
6911 supports the `load' command. This is only useful if you have some
6912 other way of getting the stub to the target system, and you can put it
6913 somewhere in memory where it won't get clobbered by the download.
6915 Filename completion now works.
6917 When run under emacs mode, the "info line" command now causes the
6918 arrow to point to the line specified. Also, "info line" prints
6919 addresses in symbolic form (as well as hex).
6921 All vxworks based targets now support a user settable option, called
6922 vxworks-timeout. This option represents the number of seconds gdb
6923 should wait for responses to rpc's. You might want to use this if
6924 your vxworks target is, perhaps, a slow software simulator or happens
6925 to be on the far side of a thin network line.
6929 This release contains support for using a DEC alpha as a GDB host for
6930 cross debugging. Native alpha debugging is not supported yet.
6933 *** Changes in GDB-4.9:
6937 This is the first GDB release which is accompanied by a matching testsuite.
6938 The testsuite requires installation of dejagnu, which should be available
6939 via ftp from most sites that carry GNU software.
6943 'Cfront' style demangling has had its name changed to 'ARM' style, to
6944 emphasize that it was written from the specifications in the C++ Annotated
6945 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6946 disclaimers, it still generated too much confusion with users attempting to
6947 use gdb with AT&T cfront.
6951 GDB now uses a standard remote interface to a simulator library.
6952 So far, the library contains simulators for the Zilog Z8001/2, the
6953 Hitachi H8/300, H8/500 and Super-H.
6955 * New targets supported
6957 H8/300 simulator h8300-hitachi-hms or h8300hms
6958 H8/500 simulator h8500-hitachi-hms or h8500hms
6959 SH simulator sh-hitachi-hms or sh
6960 Z8000 simulator z8k-zilog-none or z8ksim
6961 IDT MIPS board over serial line mips-idt-ecoff
6963 Cross-debugging to GO32 targets is supported. It requires a custom
6964 version of the i386-stub.c module which is integrated with the
6965 GO32 memory extender.
6967 * New remote protocols
6969 MIPS remote debugging protocol.
6971 * New source languages supported
6973 This version includes preliminary support for Chill, a Pascal like language
6974 used by telecommunications companies. Chill support is also being integrated
6975 into the GNU compiler, but we don't know when it will be publically available.
6978 *** Changes in GDB-4.8:
6980 * HP Precision Architecture supported
6982 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6983 version of this support was available as a set of patches from the
6984 University of Utah. GDB does not support debugging of programs
6985 compiled with the HP compiler, because HP will not document their file
6986 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6987 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6989 Many problems in the preliminary version have been fixed.
6991 * Faster and better demangling
6993 We have improved template demangling and fixed numerous bugs in the GNU style
6994 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6995 character types (wchar_t) are now supported. Demangling of each symbol is now
6996 only done once, and is cached when the symbol table for a file is read in.
6997 This results in a small increase in memory usage for C programs, a moderate
6998 increase in memory usage for C++ programs, and a fantastic speedup in
7001 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7002 from the specifications in the Annotated Reference Manual, which AT&T's
7003 compiler does not actually implement.
7005 * G++ multiple inheritance compiler problem
7007 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7008 inheritance lattices was reworked to properly discover ambiguities. We
7009 recently found an example which causes this new algorithm to fail in a
7010 very subtle way, producing bad debug information for those classes.
7011 The file 'gcc.patch' (in this directory) can be applied to gcc to
7012 circumvent the problem. A future GCC release will contain a complete
7015 The previous G++ debug info problem (mentioned below for the gdb-4.7
7016 release) is fixed in gcc version 2.3.2.
7018 * Improved configure script
7020 The `configure' script will now attempt to guess your system type if
7021 you don't supply a host system type. The old scheme of supplying a
7022 host system triplet is preferable over using this. All the magic is
7023 done in the new `config.guess' script. Examine it for details.
7025 We have also brought our configure script much more in line with the FSF's
7026 version. It now supports the --with-xxx options. In particular,
7027 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7028 The resulting GDB will not be able to read arbitrary object file formats --
7029 only the format ``expected'' to be used on the configured target system.
7030 We hope to make this the default in a future release.
7032 * Documentation improvements
7034 There's new internal documentation on how to modify GDB, and how to
7035 produce clean changes to the code. We implore people to read it
7036 before submitting changes.
7038 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7039 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7040 `info' files are also provided. To build `info' files from scratch,
7041 you will need the latest `makeinfo' release, which will be available in
7042 a future texinfo-X.Y release.
7044 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7045 We're not sure exactly which versions have this problem, but it has
7046 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7047 or better. If that isn't possible, there is a patch in
7048 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7049 around this problem.
7053 GDB now supports array constants that can be used in expressions typed in by
7054 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7055 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7058 The new directory `gdb/sparclite' contains a program that demonstrates
7059 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7061 * New native hosts supported
7063 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7064 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7066 * New targets supported
7068 AMD 29k family via UDI a29k-amd-udi or udi29k
7070 * New file formats supported
7072 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7073 HPUX core files, and SCO 3.2v2 core files.
7077 Attaching to processes now works again; thanks for the many bug reports.
7079 We have also stomped on a bunch of core dumps caused by
7080 printf_filtered("%s") problems.
7082 We eliminated a copyright problem on the rpc and ptrace header files
7083 for VxWorks, which was discovered at the last minute during the 4.7
7084 release. You should now be able to build a VxWorks GDB.
7086 You can now interrupt gdb while an attached process is running. This
7087 will cause the attached process to stop, and give control back to GDB.
7089 We fixed problems caused by using too many file descriptors
7090 for reading symbols from object files and libraries. This was
7091 especially a problem for programs that used many (~100) shared
7094 The `step' command now only enters a subroutine if there is line number
7095 information for the subroutine. Otherwise it acts like the `next'
7096 command. Previously, `step' would enter subroutines if there was
7097 any debugging information about the routine. This avoids problems
7098 when using `cc -g1' on MIPS machines.
7100 * Internal improvements
7102 GDB's internal interfaces have been improved to make it easier to support
7103 debugging of multiple languages in the future.
7105 GDB now uses a common structure for symbol information internally.
7106 Minimal symbols (derived from linkage symbols in object files), partial
7107 symbols (from a quick scan of debug information), and full symbols
7108 contain a common subset of information, making it easier to write
7109 shared code that handles any of them.
7111 * New command line options
7113 We now accept --silent as an alias for --quiet.
7117 The memory-mapped-malloc library is now licensed under the GNU Library
7118 General Public License.
7120 *** Changes in GDB-4.7:
7122 * Host/native/target split
7124 GDB has had some major internal surgery to untangle the support for
7125 hosts and remote targets. Now, when you configure GDB for a remote
7126 target, it will no longer load in all of the support for debugging
7127 local programs on the host. When fully completed and tested, this will
7128 ensure that arbitrary host/target combinations are possible.
7130 The primary conceptual shift is to separate the non-portable code in
7131 GDB into three categories. Host specific code is required any time GDB
7132 is compiled on that host, regardless of the target. Target specific
7133 code relates to the peculiarities of the target, but can be compiled on
7134 any host. Native specific code is everything else: it can only be
7135 built when the host and target are the same system. Child process
7136 handling and core file support are two common `native' examples.
7138 GDB's use of /proc for controlling Unix child processes is now cleaner.
7139 It has been split out into a single module under the `target_ops' vector,
7140 plus two native-dependent functions for each system that uses /proc.
7142 * New hosts supported
7144 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7145 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7146 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7148 * New targets supported
7150 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7151 68030 and CPU32 m68030-*-*, m68332-*-*
7153 * New native hosts supported
7155 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7156 (386bsd is not well tested yet)
7157 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7159 * New file formats supported
7161 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7162 supports reading of `a.out.adobe' object files, which are an a.out
7163 format extended with minimal information about multiple sections.
7167 `show copying' is the same as the old `info copying'.
7168 `show warranty' is the same as `info warrantee'.
7169 These were renamed for consistency. The old commands continue to work.
7171 `info handle' is a new alias for `info signals'.
7173 You can now define pre-command hooks, which attach arbitrary command
7174 scripts to any command. The commands in the hook will be executed
7175 prior to the user's command. You can also create a hook which will be
7176 executed whenever the program stops. See gdb.texinfo.
7180 We now deal with Cfront style name mangling, and can even extract type
7181 info from mangled symbols. GDB can automatically figure out which
7182 symbol mangling style your C++ compiler uses.
7184 Calling of methods and virtual functions has been improved as well.
7188 The crash that occured when debugging Sun Ansi-C compiled binaries is
7189 fixed. This was due to mishandling of the extra N_SO stabs output
7192 We also finally got Ultrix 4.2 running in house, and fixed core file
7193 support, with help from a dozen people on the net.
7195 John M. Farrell discovered that the reason that single-stepping was so
7196 slow on all of the Mips based platforms (primarily SGI and DEC) was
7197 that we were trying to demangle and lookup a symbol used for internal
7198 purposes on every instruction that was being stepped through. Changing
7199 the name of that symbol so that it couldn't be mistaken for a C++
7200 mangled symbol sped things up a great deal.
7202 Rich Pixley sped up symbol lookups in general by getting much smarter
7203 about when C++ symbol mangling is necessary. This should make symbol
7204 completion (TAB on the command line) much faster. It's not as fast as
7205 we'd like, but it's significantly faster than gdb-4.6.
7209 A new user controllable variable 'call_scratch_address' can
7210 specify the location of a scratch area to be used when GDB
7211 calls a function in the target. This is necessary because the
7212 usual method of putting the scratch area on the stack does not work
7213 in systems that have separate instruction and data spaces.
7215 We integrated changes to support the 29k UDI (Universal Debugger
7216 Interface), but discovered at the last minute that we didn't have all
7217 of the appropriate copyright paperwork. We are working with AMD to
7218 resolve this, and hope to have it available soon.
7222 We have sped up the remote serial line protocol, especially for targets
7223 with lots of registers. It now supports a new `expedited status' ('T')
7224 message which can be used in place of the existing 'S' status message.
7225 This allows the remote stub to send only the registers that GDB
7226 needs to make a quick decision about single-stepping or conditional
7227 breakpoints, eliminating the need to fetch the entire register set for
7228 each instruction being stepped through.
7230 The GDB remote serial protocol now implements a write-through cache for
7231 registers, only re-reading the registers if the target has run.
7233 There is also a new remote serial stub for SPARC processors. You can
7234 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7235 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7236 processor with a serial port.
7240 Configure.in files have become much easier to read and modify. A new
7241 `table driven' format makes it more obvious what configurations are
7242 supported, and what files each one uses.
7246 There is a new opcodes library which will eventually contain all of the
7247 disassembly routines and opcode tables. At present, it only contains
7248 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7249 disassembler (binutils/objdump) to share these routines.
7251 The libiberty library is now copylefted under the GNU Library General
7252 Public License. This allows more liberal use, and was done so libg++
7253 can use it. This makes no difference to GDB, since the Library License
7254 grants all the rights from the General Public License.
7258 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7259 reference to the stabs symbol info used by the debugger. It is (as far
7260 as we know) the only published document on this fascinating topic. We
7261 encourage you to read it, compare it to the stabs information on your
7262 system, and send improvements on the document in general (to
7263 bug-gdb@prep.ai.mit.edu).
7265 And, of course, many bugs have been fixed.
7268 *** Changes in GDB-4.6:
7270 * Better support for C++ function names
7272 GDB now accepts as input the "demangled form" of C++ overloaded function
7273 names and member function names, and can do command completion on such names
7274 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7275 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7276 Make use of command completion, it is your friend.
7278 GDB also now accepts a variety of C++ mangled symbol formats. They are
7279 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7280 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7281 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7282 for the list of formats.
7284 * G++ symbol mangling problem
7286 Recent versions of gcc have a bug in how they emit debugging information for
7287 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7288 directory) can be applied to gcc to fix the problem. Alternatively, if you
7289 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7290 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7291 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7294 * New 'maintenance' command
7296 All of the commands related to hacking GDB internals have been moved out of
7297 the main command set, and now live behind the 'maintenance' command. This
7298 can also be abbreviated as 'mt'. The following changes were made:
7300 dump-me -> maintenance dump-me
7301 info all-breakpoints -> maintenance info breakpoints
7302 printmsyms -> maintenance print msyms
7303 printobjfiles -> maintenance print objfiles
7304 printpsyms -> maintenance print psymbols
7305 printsyms -> maintenance print symbols
7307 The following commands are new:
7309 maintenance demangle Call internal GDB demangler routine to
7310 demangle a C++ link name and prints the result.
7311 maintenance print type Print a type chain for a given symbol
7313 * Change to .gdbinit file processing
7315 We now read the $HOME/.gdbinit file before processing the argv arguments
7316 (e.g. reading symbol files or core files). This allows global parameters to
7317 be set, which will apply during the symbol reading. The ./.gdbinit is still
7318 read after argv processing.
7320 * New hosts supported
7322 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7324 GNU/Linux support i386-unknown-linux or linux
7326 We are also including code to support the HP/PA running BSD and HPUX. This
7327 is almost guaranteed not to work, as we didn't have time to test or build it
7328 for this release. We are including it so that the more adventurous (or
7329 masochistic) of you can play with it. We also had major problems with the
7330 fact that the compiler that we got from HP doesn't support the -g option.
7333 * New targets supported
7335 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7337 * More smarts about finding #include files
7339 GDB now remembers the compilation directory for all include files, and for
7340 all files from which C is generated (like yacc and lex sources). This
7341 greatly improves GDB's ability to find yacc/lex sources, and include files,
7342 especially if you are debugging your program from a directory different from
7343 the one that contains your sources.
7345 We also fixed a bug which caused difficulty with listing and setting
7346 breakpoints in include files which contain C code. (In the past, you had to
7347 try twice in order to list an include file that you hadn't looked at before.)
7349 * Interesting infernals change
7351 GDB now deals with arbitrary numbers of sections, where the symbols for each
7352 section must be relocated relative to that section's landing place in the
7353 target's address space. This work was needed to support ELF with embedded
7354 stabs used by Solaris-2.0.
7356 * Bug fixes (of course!)
7358 There have been loads of fixes for the following things:
7359 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7360 i960, stabs, DOS(GO32), procfs, etc...
7362 See the ChangeLog for details.
7364 *** Changes in GDB-4.5:
7366 * New machines supported (host and target)
7368 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7370 SGI Irix-4.x mips-sgi-irix4 or iris4
7372 * New malloc package
7374 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7375 Mmalloc is capable of handling mutiple heaps of memory. It is also
7376 capable of saving a heap to a file, and then mapping it back in later.
7377 This can be used to greatly speedup the startup of GDB by using a
7378 pre-parsed symbol table which lives in a mmalloc managed heap. For
7379 more details, please read mmalloc/mmalloc.texi.
7383 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7384 'help info proc' for details.
7386 * MIPS ecoff symbol table format
7388 The code that reads MIPS symbol table format is now supported on all hosts.
7389 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7392 * File name changes for MS-DOS
7394 Many files in the config directories have been renamed to make it easier to
7395 support GDB on MS-DOSe systems (which have very restrictive file name
7396 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7397 environment) is close to working but has some remaining problems. Note
7398 that debugging of DOS programs is not supported, due to limitations
7399 in the ``operating system'', but it can be used to host cross-debugging.
7401 * Cross byte order fixes
7403 Many fixes have been made to support cross debugging of Sparc and MIPS
7404 targets from hosts whose byte order differs.
7406 * New -mapped and -readnow options
7408 If memory-mapped files are available on your system through the 'mmap'
7409 system call, you can use the -mapped option on the `file' or
7410 `symbol-file' commands to cause GDB to write the symbols from your
7411 program into a reusable file. If the program you are debugging is
7412 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7413 Future GDB debugging sessions will notice the presence of this file,
7414 and will quickly map in symbol information from it, rather than reading
7415 the symbol table from the executable program. Using the '-mapped'
7416 option in a GDB `file' or `symbol-file' command has the same effect as
7417 starting GDB with the '-mapped' command-line option.
7419 You can cause GDB to read the entire symbol table immediately by using
7420 the '-readnow' option with any of the commands that load symbol table
7421 information (or on the GDB command line). This makes the command
7422 slower, but makes future operations faster.
7424 The -mapped and -readnow options are typically combined in order to
7425 build a `fred.syms' file that contains complete symbol information.
7426 A simple GDB invocation to do nothing but build a `.syms' file for future
7429 gdb -batch -nx -mapped -readnow programname
7431 The `.syms' file is specific to the host machine on which GDB is run.
7432 It holds an exact image of GDB's internal symbol table. It cannot be
7433 shared across multiple host platforms.
7435 * longjmp() handling
7437 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7438 siglongjmp() without losing control. This feature has not yet been ported to
7439 all systems. It currently works on many 386 platforms, all MIPS-based
7440 platforms (SGI, DECstation, etc), and Sun3/4.
7444 Preliminary work has been put in to support the new Solaris OS from Sun. At
7445 this time, it can control and debug processes, but it is not capable of
7450 As always, many many bug fixes. The major areas were with g++, and mipsread.
7451 People using the MIPS-based platforms should experience fewer mysterious
7452 crashes and trashed symbol tables.
7454 *** Changes in GDB-4.4:
7456 * New machines supported (host and target)
7458 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7460 BSD Reno on Vax vax-dec-bsd
7461 Ultrix on Vax vax-dec-ultrix
7463 * New machines supported (target)
7465 AMD 29000 embedded, using EBMON a29k-none-none
7469 GDB continues to improve its handling of C++. `References' work better.
7470 The demangler has also been improved, and now deals with symbols mangled as
7471 per the Annotated C++ Reference Guide.
7473 GDB also now handles `stabs' symbol information embedded in MIPS
7474 `ecoff' symbol tables. Since the ecoff format was not easily
7475 extensible to handle new languages such as C++, this appeared to be a
7476 good way to put C++ debugging info into MIPS binaries. This option
7477 will be supported in the GNU C compiler, version 2, when it is
7480 * New features for SVR4
7482 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7483 shared libraries. Debugging dynamically linked programs should present
7484 only minor differences from debugging statically linked programs.
7486 The `info proc' command will print out information about any process
7487 on an SVR4 system (including the one you are debugging). At the moment,
7488 it prints the address mappings of the process.
7490 If you bring up GDB on another SVR4 system, please send mail to
7491 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7493 * Better dynamic linking support in SunOS
7495 Reading symbols from shared libraries which contain debugging symbols
7496 now works properly. However, there remain issues such as automatic
7497 skipping of `transfer vector' code during function calls, which
7498 make it harder to debug code in a shared library, than to debug the
7499 same code linked statically.
7503 GDB is now using the latest `getopt' routines from the FSF. This
7504 version accepts the -- prefix for options with long names. GDB will
7505 continue to accept the old forms (-option and +option) as well.
7506 Various single letter abbreviations for options have been explicity
7507 added to the option table so that they won't get overshadowed in the
7508 future by other options that begin with the same letter.
7512 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7513 Many assorted bugs have been handled. Many more remain to be handled.
7514 See the various ChangeLog files (primarily in gdb and bfd) for details.
7517 *** Changes in GDB-4.3:
7519 * New machines supported (host and target)
7521 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7522 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7523 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7525 * Almost SCO Unix support
7527 We had hoped to support:
7528 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7529 (except for core file support), but we discovered very late in the release
7530 that it has problems with process groups that render gdb unusable. Sorry
7531 about that. I encourage people to fix it and post the fixes.
7533 * Preliminary ELF and DWARF support
7535 GDB can read ELF object files on System V Release 4, and can handle
7536 debugging records for C, in DWARF format, in ELF files. This support
7537 is preliminary. If you bring up GDB on another SVR4 system, please
7538 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7543 GDB now uses the latest `readline' library. One user-visible change
7544 is that two tabs will list possible command completions, which previously
7545 required typing M-? (meta-question mark, or ESC ?).
7549 The `stepi' bug that many of you noticed has been squashed.
7550 Many bugs in C++ have been handled. Many more remain to be handled.
7551 See the various ChangeLog files (primarily in gdb and bfd) for details.
7553 * State of the MIPS world (in case you wondered):
7555 GDB can understand the symbol tables emitted by the compilers
7556 supplied by most vendors of MIPS-based machines, including DEC. These
7557 symbol tables are in a format that essentially nobody else uses.
7559 Some versions of gcc come with an assembler post-processor called
7560 mips-tfile. This program is required if you want to do source-level
7561 debugging of gcc-compiled programs. I believe FSF does not ship
7562 mips-tfile with gcc version 1, but it will eventually come with gcc
7565 Debugging of g++ output remains a problem. g++ version 1.xx does not
7566 really support it at all. (If you're lucky, you should be able to get
7567 line numbers and stack traces to work, but no parameters or local
7568 variables.) With some work it should be possible to improve the
7571 When gcc version 2 is released, you will have somewhat better luck.
7572 However, even then you will get confusing results for inheritance and
7575 We will eventually provide full debugging of g++ output on
7576 DECstations. This will probably involve some kind of stabs-in-ecoff
7577 encapulation, but the details have not been worked out yet.
7580 *** Changes in GDB-4.2:
7582 * Improved configuration
7584 Only one copy of `configure' exists now, and it is not self-modifying.
7585 Porting BFD is simpler.
7589 The `step' and `next' commands now only stop at the first instruction
7590 of a source line. This prevents the multiple stops that used to occur
7591 in switch statements, for-loops, etc. `Step' continues to stop if a
7592 function that has debugging information is called within the line.
7596 Lots of small bugs fixed. More remain.
7598 * New host supported (not target)
7600 Intel 386 PC clone running Mach i386-none-mach
7603 *** Changes in GDB-4.1:
7605 * Multiple source language support
7607 GDB now has internal scaffolding to handle several source languages.
7608 It determines the type of each source file from its filename extension,
7609 and will switch expression parsing and number formatting to match the
7610 language of the function in the currently selected stack frame.
7611 You can also specifically set the language to be used, with
7612 `set language c' or `set language modula-2'.
7616 GDB now has preliminary support for the GNU Modula-2 compiler,
7617 currently under development at the State University of New York at
7618 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7619 continue through the fall of 1991 and into 1992.
7621 Other Modula-2 compilers are currently not supported, and attempting to
7622 debug programs compiled with them will likely result in an error as the
7623 symbol table is read. Feel free to work on it, though!
7625 There are hooks in GDB for strict type checking and range checking,
7626 in the `Modula-2 philosophy', but they do not currently work.
7630 GDB can now write to executable and core files (e.g. patch
7631 a variable's value). You must turn this switch on, specify
7632 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7633 by assigning a new value to a variable. Modifications take
7636 * Automatic SunOS shared library reading
7638 When you run your program, GDB automatically determines where its
7639 shared libraries (if any) have been loaded, and reads their symbols.
7640 The `share' command is no longer needed. This also works when
7641 examining core files.
7645 You can specify the number of lines that the `list' command shows.
7648 * New machines supported (host and target)
7650 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7651 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7652 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7654 * New hosts supported (not targets)
7656 IBM RT/PC: romp-ibm-aix or rtpc
7658 * New targets supported (not hosts)
7660 AMD 29000 embedded with COFF a29k-none-coff
7661 AMD 29000 embedded with a.out a29k-none-aout
7662 Ultracomputer remote kernel debug a29k-nyu-kern
7664 * New remote interfaces
7670 *** Changes in GDB-4.0:
7674 Wide output is wrapped at good places to make the output more readable.
7676 Gdb now supports cross-debugging from a host machine of one type to a
7677 target machine of another type. Communication with the target system
7678 is over serial lines. The ``target'' command handles connecting to the
7679 remote system; the ``load'' command will download a program into the
7680 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7681 also supports debugging of realtime processes running under VxWorks,
7682 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7683 stub on the target system.
7685 New CPUs supported include the AMD 29000 and Intel 960.
7687 GDB now reads object files and symbol tables via a ``binary file''
7688 library, which allows a single copy of GDB to debug programs of multiple
7689 object file types such as a.out and coff.
7691 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7692 refcard.dvi and refcard.ps are available to format it).
7695 * Control-Variable user interface simplified
7697 All variables that control the operation of the debugger can be set
7698 by the ``set'' command, and displayed by the ``show'' command.
7700 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7701 ``Show prompt'' produces the response:
7702 Gdb's prompt is new-gdb=>.
7704 What follows are the NEW set commands. The command ``help set'' will
7705 print a complete list of old and new set commands. ``help set FOO''
7706 will give a longer description of the variable FOO. ``show'' will show
7707 all of the variable descriptions and their current settings.
7709 confirm on/off: Enables warning questions for operations that are
7710 hard to recover from, e.g. rerunning the program while
7711 it is already running. Default is ON.
7713 editing on/off: Enables EMACS style command line editing
7714 of input. Previous lines can be recalled with
7715 control-P, the current line can be edited with control-B,
7716 you can search for commands with control-R, etc.
7719 history filename NAME: NAME is where the gdb command history
7720 will be stored. The default is .gdb_history,
7721 or the value of the environment variable
7724 history size N: The size, in commands, of the command history. The
7725 default is 256, or the value of the environment variable
7728 history save on/off: If this value is set to ON, the history file will
7729 be saved after exiting gdb. If set to OFF, the
7730 file will not be saved. The default is OFF.
7732 history expansion on/off: If this value is set to ON, then csh-like
7733 history expansion will be performed on
7734 command line input. The default is OFF.
7736 radix N: Sets the default radix for input and output. It can be set
7737 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7738 in the current radix, so "set radix 10" is always a no-op.
7740 height N: This integer value is the number of lines on a page. Default
7741 is 24, the current `stty rows'' setting, or the ``li#''
7742 setting from the termcap entry matching the environment
7745 width N: This integer value is the number of characters on a line.
7746 Default is 80, the current `stty cols'' setting, or the ``co#''
7747 setting from the termcap entry matching the environment
7750 Note: ``set screensize'' is obsolete. Use ``set height'' and
7751 ``set width'' instead.
7753 print address on/off: Print memory addresses in various command displays,
7754 such as stack traces and structure values. Gdb looks
7755 more ``symbolic'' if you turn this off; it looks more
7756 ``machine level'' with it on. Default is ON.
7758 print array on/off: Prettyprint arrays. New convenient format! Default
7761 print demangle on/off: Print C++ symbols in "source" form if on,
7764 print asm-demangle on/off: Same, for assembler level printouts
7767 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7770 * Support for Epoch Environment.
7772 The epoch environment is a version of Emacs v18 with windowing. One
7773 new command, ``inspect'', is identical to ``print'', except that if you
7774 are running in the epoch environment, the value is printed in its own
7778 * Support for Shared Libraries
7780 GDB can now debug programs and core files that use SunOS shared libraries.
7781 Symbols from a shared library cannot be referenced
7782 before the shared library has been linked with the program (this
7783 happens after you type ``run'' and before the function main() is entered).
7784 At any time after this linking (including when examining core files
7785 from dynamically linked programs), gdb reads the symbols from each
7786 shared library when you type the ``sharedlibrary'' command.
7787 It can be abbreviated ``share''.
7789 sharedlibrary REGEXP: Load shared object library symbols for files
7790 matching a unix regular expression. No argument
7791 indicates to load symbols for all shared libraries.
7793 info sharedlibrary: Status of loaded shared libraries.
7798 A watchpoint stops execution of a program whenever the value of an
7799 expression changes. Checking for this slows down execution
7800 tremendously whenever you are in the scope of the expression, but is
7801 quite useful for catching tough ``bit-spreader'' or pointer misuse
7802 problems. Some machines such as the 386 have hardware for doing this
7803 more quickly, and future versions of gdb will use this hardware.
7805 watch EXP: Set a watchpoint (breakpoint) for an expression.
7807 info watchpoints: Information about your watchpoints.
7809 delete N: Deletes watchpoint number N (same as breakpoints).
7810 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7811 enable N: Re-enables watchpoint number N (same as breakpoints).
7814 * C++ multiple inheritance
7816 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7819 * C++ exception handling
7821 Gdb now supports limited C++ exception handling. Besides the existing
7822 ability to breakpoint on an exception handler, gdb can breakpoint on
7823 the raising of an exception (before the stack is peeled back to the
7826 catch FOO: If there is a FOO exception handler in the dynamic scope,
7827 set a breakpoint to catch exceptions which may be raised there.
7828 Multiple exceptions (``catch foo bar baz'') may be caught.
7830 info catch: Lists all exceptions which may be caught in the
7831 current stack frame.
7834 * Minor command changes
7836 The command ``call func (arg, arg, ...)'' now acts like the print
7837 command, except it does not print or save a value if the function's result
7838 is void. This is similar to dbx usage.
7840 The ``up'' and ``down'' commands now always print the frame they end up
7841 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7842 frames without printing.
7844 * New directory command
7846 'dir' now adds directories to the FRONT of the source search path.
7847 The path starts off empty. Source files that contain debug information
7848 about the directory in which they were compiled can be found even
7849 with an empty path; Sun CC and GCC include this information. If GDB can't
7850 find your source file in the current directory, type "dir .".
7852 * Configuring GDB for compilation
7854 For normal use, type ``./configure host''. See README or gdb.texinfo
7857 GDB now handles cross debugging. If you are remotely debugging between
7858 two different machines, type ``./configure host -target=targ''.
7859 Host is the machine where GDB will run; targ is the machine
7860 where the program that you are debugging will run.