1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * New features in the GDB remote stub, GDBserver
8 ** GDBserver is now supported on RISC-V GNU/Linux.
10 * Debugging MS-Windows processes now sets $_exitsignal when the
11 inferior is terminated by a signal, instead of setting $_exitcode.
13 * Multithreaded symbol loading has now been enabled by default on systems
14 that support it (see entry for GDB 9, below), providing faster
15 performance for programs with many symbols.
17 * The $_siginfo convenience variable now also works on Windows targets,
18 and will display the EXCEPTION_RECORD of the last handled exception.
22 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
23 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
24 Set or show the option 'exec-file-mismatch'. When GDB attaches to
25 a running process and can determine the name of the executable file
26 the process runs, this new option indicates whether to detect mismatch
27 between the name of the current executable file loaded by GDB
28 and the name of the executable file used to start the process.
29 If 'ask', the default, display a warning and ask the user
30 whether to load the process executable file; if 'warn', just display
31 a warning; if 'off', don't attempt to detect a mismatch.
35 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
39 * 'thread-exited' event is now available in the annotations interface.
41 * New built-in convenience variables $_gdb_major and $_gdb_minor
42 provide the GDB version. They are handy for conditionally using
43 features available only in or since specific GDB versions, in
44 scripts that should work error-free with many different versions,
45 such as in system-wide init files.
47 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
48 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
49 of the GDB settings and the GDB maintenance settings. They are handy
50 for changing the logic of user defined commands depending on the
53 * GDB now supports Thread Local Storage (TLS) variables on several
54 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
55 architectures require kernel changes. TLS is not yet supported for
56 amd64 and i386 process core dumps.
58 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
59 addresses that required unmasking are shown in the backtrace with the
62 * Two new convenience functions $_cimag and $_creal that extract the
63 imaginary and real parts respectively from complex numbers.
65 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
66 provide the exitcode or exit status of the shell commands launched by
67 GDB commands such as "shell", "pipe" and "make".
69 * The command define-prefix can now define user defined prefix commands.
70 User defined commands can now be defined using these user defined prefix
73 * Command names can now use the . character.
75 * The RX port now supports XML target descriptions.
77 * GDB now shows the Ada task names at more places, e.g. in task switching
80 * GDB can now be compiled with Python 3 on Windows.
82 * New convenience variable $_ada_exception holds the address of the
83 Ada exception being thrown. This is set by Ada-related catchpoints.
85 * GDB can now place breakpoints on nested functions and subroutines in
86 Fortran code. The '::' operator can be used between parent and
87 child scopes when placing breakpoints, for example:
89 (gdb) break outer_function::inner_function
91 The 'outer_function::' prefix is only needed if 'inner_function' is
92 not visible in the current scope.
94 * In addition to the system-wide gdbinit file, if configured with
95 --with-system-gdbinit-dir, GDB will now also load files in that directory
96 as system gdbinit files, unless the -nx or -n flag is provided. Files
97 with extensions .gdb, .py and .scm are supported as long as GDB was
98 compiled with support for that language.
100 * GDB now supports multithreaded symbol loading for higher performance.
101 This feature is still in testing, so it is disabled by default. You
102 can turn it on using 'maint set worker-threads unlimited'.
104 * Multi-target debugging support
106 GDB now supports debugging multiple target connections
107 simultaneously. For example, you can now have each inferior
108 connected to different remote servers running in different machines,
109 or have one inferior debugging a local native process, an inferior
110 debugging a core dump, etc.
112 This support is experimental and comes with some limitations -- you
113 can only resume multiple targets simultaneously if all targets
114 support non-stop mode, and all remote stubs or servers must support
115 the same set of remote protocol features exactly. See also "info
116 connections" and "add-inferior -no-connection" below, and "maint set
117 target-non-stop" in the user manual.
121 ** The gdb.Value type has a new method 'format_string' which returns a
122 string representing the value. The formatting is controlled by the
123 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
124 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
125 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
127 ** gdb.Type has a new property 'objfile' which returns the objfile the
130 ** The frame information printed by the python frame filtering code
131 is now consistent with what the 'backtrace' command prints when
132 there are no filters, or when the 'backtrace' '-no-filters' option
135 ** The new function gdb.lookup_static_symbol can be used to look up
136 symbols with static linkage.
138 ** The new function gdb.lookup_static_symbols can be used to look up
139 all static symbols with static linkage.
141 ** gdb.Objfile has new methods 'lookup_global_symbol' and
142 'lookup_static_symbol' to lookup a symbol from this objfile only.
144 ** gdb.Block now supports the dictionary syntax for accessing symbols in
145 this block (e.g. block['local_variable']).
149 | [COMMAND] | SHELL_COMMAND
150 | -d DELIM COMMAND DELIM SHELL_COMMAND
151 pipe [COMMAND] | SHELL_COMMAND
152 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
153 Executes COMMAND and sends its output to SHELL_COMMAND.
154 With no COMMAND, repeat the last executed command
155 and send its output to SHELL_COMMAND.
157 define-prefix COMMAND
158 Define or mark a command as a user-defined prefix command.
160 with SETTING [VALUE] [-- COMMAND]
161 w SETTING [VALUE] [-- COMMAND]
162 Temporarily set SETTING, run COMMAND, and restore SETTING.
163 Usage: with SETTING -- COMMAND
164 With no COMMAND, repeats the last executed command.
165 SETTING is any GDB setting you can change with the "set"
166 subcommands. For example, 'with language c -- print someobj'
167 temporarily switches to the C language in order to print someobj.
168 Settings can be combined: 'w lang c -- w print elements unlimited --
169 usercmd' switches to the C language and runs usercmd with no limit
170 of array elements to print.
172 maint with SETTING [VALUE] [-- COMMAND]
173 Like "with", but works with "maintenance set" settings.
175 set may-call-functions [on|off]
176 show may-call-functions
177 This controls whether GDB will attempt to call functions in
178 the program, such as with expressions in the print command. It
179 defaults to on. Calling functions in the program being debugged
180 can have undesired side effects. It is now possible to forbid
181 such function calls. If function calls are forbidden, GDB will throw
182 an error when a command (such as print expression) calls a function
185 set print finish [on|off]
187 This controls whether the `finish' command will display the value
188 that is returned by the current function. When `off', the value is
189 still entered into the value history, but it is not printed. The
194 Allows deeply nested structures to be simplified when printing by
195 replacing deeply nested parts (beyond the max-depth) with ellipses.
196 The default max-depth is 20, but this can be set to unlimited to get
197 the old behavior back.
199 set print raw-values [on|off]
200 show print raw-values
201 By default, GDB applies the enabled pretty printers when printing a
202 value. This allows to ignore the enabled pretty printers for a series
203 of commands. The default is 'off'.
205 set logging debugredirect [on|off]
206 By default, GDB debug output will go to both the terminal and the logfile.
207 Set if you want debug output to go only to the log file.
209 set style title foreground COLOR
210 set style title background COLOR
211 set style title intensity VALUE
212 Control the styling of titles.
214 set style highlight foreground COLOR
215 set style highlight background COLOR
216 set style highlight intensity VALUE
217 Control the styling of highlightings.
219 maint set worker-threads
220 maint show worker-threads
221 Control the number of worker threads that can be used by GDB. The
222 default is 0. "unlimited" lets GDB choose a number that is
223 reasonable. Currently worker threads are only used when demangling
224 the names of linker symbols.
226 set style tui-border foreground COLOR
227 set style tui-border background COLOR
228 Control the styling of TUI borders.
230 set style tui-active-border foreground COLOR
231 set style tui-active-border background COLOR
232 Control the styling of the active TUI border.
234 maint set test-settings KIND
235 maint show test-settings KIND
236 A set of commands used by the testsuite for exercising the settings
239 maint set tui-resize-message [on|off]
240 maint show tui-resize-message
241 Control whether GDB prints a message each time the terminal is
242 resized when in TUI mode. This is primarily useful for testing the
245 set print frame-info [short-location|location|location-and-address
246 |source-and-location|source-line|auto]
247 show print frame-info
248 This controls what frame information is printed by the commands printing
249 a frame. This setting will e.g. influence the behaviour of 'backtrace',
250 'frame', 'stepi'. The python frame filtering also respect this setting.
251 The 'backtrace' '-frame-info' option can override this global setting.
253 set tui compact-source
254 show tui compact-source
256 Enable the "compact" display mode for the TUI source window. The
257 compact display uses only as much space as is needed for the line
258 numbers in the current file, and only a single space to separate the
259 line numbers from the source.
261 info modules [-q] [REGEXP]
262 Return a list of Fortran modules matching REGEXP, or all modules if
265 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
266 Return a list of functions within all modules, grouped by module.
267 The list of functions can be restricted with the optional regular
268 expressions. MODULE_REGEXP matches against the module name,
269 TYPE_REGEXP matches against the function type signature, and REGEXP
270 matches against the function name.
272 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
273 Return a list of variables within all modules, grouped by module.
274 The list of variables can be restricted with the optional regular
275 expressions. MODULE_REGEXP matches against the module name,
276 TYPE_REGEXP matches against the variable type, and REGEXP matches
277 against the variable name.
279 set debug remote-packet-max-chars
280 show debug remote-packet-max-chars
281 Controls the number of characters to output in a remote packet when using
283 The default is 512 bytes.
286 Lists the target connections currently in use.
291 The "help" command uses the title style to enhance the
292 readibility of its output by styling the classes and
296 Similarly to "help", the "apropos" command also uses the
297 title style for the command names. "apropos" accepts now
298 a flag "-v" (verbose) to show the full documentation
299 of matching commands and to use the highlight style to mark
300 the documentation parts matching REGEXP.
304 The GDB printf and eval commands can now print C-style and Ada-style
305 string convenience variables without calling functions in the program.
306 This allows to do formatted printing of strings without having
307 a running inferior, or when debugging a core dump.
309 info sources [-dirname | -basename] [--] [REGEXP]
310 This command has now optional arguments to only print the files
311 whose names match REGEXP. The arguments -dirname and -basename
312 allow to restrict matching respectively to the dirname and basename
316 The "show style" and its subcommands are now styling
317 a style name in their output using its own style, to help
318 the user visualize the different styles.
320 set print frame-arguments
321 The new value 'presence' indicates to only indicate the presence of
322 arguments using ..., instead of printing argument names and values.
324 set print raw-frame-arguments
325 show print raw-frame-arguments
327 These commands replace the similarly-named "set/show print raw
328 frame-arguments" commands (now with a dash instead of a space). The
329 old commands are now deprecated and may be removed in a future
332 add-inferior [-no-connection]
333 The add-inferior command now supports a "-no-connection" flag that
334 makes the new inferior start with no target connection associated.
335 By default, the new inferior inherits the target connection of the
336 current inferior. See also "info connections".
339 This command's output now includes a new "Connection" column
340 indicating which target connection an inferior is bound to. See
341 "info connections" above.
343 maint test-options require-delimiter
344 maint test-options unknown-is-error
345 maint test-options unknown-is-operand
346 maint show test-options-completion-result
347 Commands used by the testsuite to validate the command options
350 focus, winheight, +, -, >, <
351 These commands are now case-sensitive.
353 * New command options, command completion
355 GDB now has a standard infrastructure to support dash-style command
356 options ('-OPT'). One benefit is that commands that use it can
357 easily support completion of command line arguments. Try "CMD
358 -[TAB]" or "help CMD" to find options supported by a command. Over
359 time, we intend to migrate most commands to this infrastructure. A
360 number of commands got support for new command options in this
363 ** The "print" and "compile print" commands now support a number of
364 options that allow overriding relevant global print settings as
365 set by "set print" subcommands:
369 -array-indexes [on|off]
370 -elements NUMBER|unlimited
375 -repeats NUMBER|unlimited
376 -static-members [on|off]
381 Note that because the "print"/"compile print" commands accept
382 arbitrary expressions which may look like options (including
383 abbreviations), if you specify any command option, then you must
384 use a double dash ("--") to mark the end of argument processing.
386 ** The "backtrace" command now supports a number of options that
387 allow overriding relevant global print settings as set by "set
388 backtrace" and "set print" subcommands:
390 -entry-values no|only|preferred|if-needed|both|compact|default
391 -frame-arguments all|scalars|none
392 -raw-frame-arguments [on|off]
393 -frame-info auto|source-line|location|source-and-location
394 |location-and-address|short-location
398 In addition, the full/no-filters/hide qualifiers are now also
399 exposed as command options too:
405 ** The "frame apply", "tfaas" and "faas" commands similarly now
406 support the following options:
411 ** The new "info sources" options -dirname and -basename options
412 are using the standard '-OPT' infrastructure.
414 All options above can also be abbreviated. The argument of boolean
415 (on/off) options can be 0/1 too, and also the argument is assumed
416 "on" if omitted. This allows writing compact command invocations,
419 (gdb) p -ra -p -o 0 -- *myptr
421 The above is equivalent to:
423 (gdb) print -raw-values -pretty -object off -- *myptr
425 ** The "info types" command now supports the '-q' flag to disable
426 printing of some header information in a similar fashion to "info
427 variables" and "info functions".
429 ** The "info variables", "info functions", and "whereis" commands
430 now take a '-n' flag that excludes non-debug symbols (symbols
431 from the symbol table, not from the debug info such as DWARF)
434 * Completion improvements
436 ** GDB can now complete the options of the "thread apply all" and
437 "taas" commands, and their "-ascending" option can now be
440 ** GDB can now complete the options of the "info threads", "info
441 functions", "info variables", "info locals", and "info args"
444 ** GDB can now complete the options of the "compile file" and
445 "compile code" commands. The "compile file" command now
446 completes on filenames.
448 ** GDB can now complete the backtrace command's
449 "full/no-filters/hide" qualifiers.
451 * In settings, you can now abbreviate "unlimited".
453 E.g., "set print elements u" is now equivalent to "set print
459 This lists all the possible completions for the rest of the line, if it
460 were to be given as a command itself. This is intended for use by MI
461 frontends in cases when separate CLI and MI channels cannot be used.
463 -catch-throw, -catch-rethrow, and -catch-catch
464 These can be used to catch C++ exceptions in a similar fashion to
465 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
467 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
468 These commands are the MI equivalent of the CLI commands 'info
469 functions', 'info types', and 'info variables' respectively.
471 -symbol-info-modules, this is the MI equivalent of the CLI 'info
474 -symbol-info-module-functions and -symbol-info-module-variables.
475 These commands are the MI equivalent of the CLI commands 'info
476 module functions' and 'info module variables'.
480 ** The default version of the MI interpreter is now 3 (-i=mi3).
482 ** The output of information about multi-location breakpoints (which is
483 syntactically incorrect in MI 2) has changed in MI 3. This affects
484 the following commands and events:
488 - =breakpoint-created
489 - =breakpoint-modified
491 The -fix-multi-location-breakpoint-output command can be used to enable
492 this behavior with previous MI versions.
494 ** Backtraces and frames include a new optional field addr_flags which is
495 given after the addr field. On AArch64 this contains PAC if the address
496 has been masked in the frame. On all other targets the field is not
501 The testsuite now creates the files gdb.cmd (containing the arguments
502 used to launch GDB) and gdb.in (containing all the commands sent to
503 GDB) in the output directory for each test script. Multiple invocations
504 are appended with .1, .2, .3 etc.
506 * Building GDB and GDBserver now requires GNU make >= 3.82.
508 Using another implementation of the make program or an earlier version of
509 GNU make to build GDB or GDBserver is not supported.
511 * Building GDB now requires GNU readline >= 7.0.
513 GDB now bundles GNU readline 8.0, but if you choose to use
514 --with-system-readline, only readline >= 7.0 can be used.
516 * The TUI SingleKey keymap is now named "SingleKey". This can be used
517 from .inputrc to bind keys in this keymap. This feature is only
518 available when gdb is built against GNU readline 8.0 or later.
520 * Removed targets and native configurations
522 GDB no longer supports debugging the Cell Broadband Engine. This includes
523 both debugging standalone Cell/B.E. SPU applications and integrated debugging
524 of Cell/B.E. applications that use both the PPU and SPU architectures.
530 * Removed targets and native configurations
532 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
535 *** Changes in GDB 8.3
537 * GDB and GDBserver now support access to additional registers on
538 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
541 * GDB now has experimental support for the compilation and injection of
542 C++ source code into the inferior. This beta release does not include
543 support for several language features, such as templates, constructors,
546 This feature requires GCC 7.1 or higher built with libcp1.so
549 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
550 can be passed using the '[ADDRESS]:PORT' notation, or the regular
551 'ADDRESS:PORT' method.
553 * DWARF index cache: GDB can now automatically save indices of DWARF
554 symbols on disk to speed up further loading of the same binaries.
556 * Ada task switching is now supported on aarch64-elf targets when
557 debugging a program using the Ravenscar Profile. For more information,
558 see the "Tasking Support when using the Ravenscar Profile" section
559 in the GDB user manual.
561 * GDB in batch mode now exits with status 1 if the last command to be
564 * The RISC-V target now supports target descriptions.
566 * System call catchpoints now support system call aliases on FreeBSD.
567 When the ABI of a system call changes in FreeBSD, this is
568 implemented by leaving a compatibility system call using the old ABI
569 at the existing number and allocating a new system call number for
570 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
571 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
572 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
573 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
574 so that a system call catchpoint for the 'kevent' system call will
575 catch invocations of both the 'kevent' and 'freebsd11_kevent'
576 binaries. This ensures that 'kevent' system calls are caught for
577 binaries using either the old or new ABIs.
579 * Terminal styling is now available for the CLI and the TUI. GNU
580 Source Highlight can additionally be used to provide styling of
581 source code snippets. See the "set style" commands, below, for more
584 * Removed support for old demangling styles arm, edg, gnu, hp and
589 set debug compile-cplus-types
590 show debug compile-cplus-types
591 Control the display of debug output about type conversion in the
592 C++ compile feature. Commands have no effect while compiliong
597 Control whether debug output about files/functions skipping is
600 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
601 Apply a command to some frames.
602 FLAG arguments allow to control what output to produce and how to handle
603 errors raised when applying COMMAND to a frame.
606 Apply a command to all threads (ignoring errors and empty output).
607 Shortcut for 'thread apply all -s COMMAND'.
610 Apply a command to all frames (ignoring errors and empty output).
611 Shortcut for 'frame apply all -s COMMAND'.
614 Apply a command to all frames of all threads (ignoring errors and empty
616 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
618 maint set dwarf unwinders (on|off)
619 maint show dwarf unwinders
620 Control whether DWARF unwinders can be used.
623 Display a list of open files for a process.
627 Changes to the "frame", "select-frame", and "info frame" CLI commands.
628 These commands all now take a frame specification which
629 is either a frame level, or one of the keywords 'level', 'address',
630 'function', or 'view' followed by a parameter. Selecting a frame by
631 address, or viewing a frame outside the current backtrace now
632 requires the use of a keyword. Selecting a frame by level is
633 unchanged. The MI comment "-stack-select-frame" is unchanged.
635 target remote FILENAME
636 target extended-remote FILENAME
637 If FILENAME is a Unix domain socket, GDB will attempt to connect
638 to this socket instead of opening FILENAME as a character device.
640 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
641 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
642 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
643 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
644 These commands can now print only the searched entities
645 matching the provided regexp(s), giving a condition
646 on the entity names or entity types. The flag -q disables
647 printing headers or informations messages.
653 These commands now determine the syntax for the shown entities
654 according to the language chosen by `set language'. In particular,
655 `set language auto' means to automatically choose the language of
658 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
659 The 'thread apply' command accepts new FLAG arguments.
660 FLAG arguments allow to control what output to produce and how to handle
661 errors raised when applying COMMAND to a thread.
663 set tui tab-width NCHARS
664 show tui tab-width NCHARS
665 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
667 set style enabled [on|off]
669 Enable or disable terminal styling. Styling is enabled by default
670 on most hosts, but disabled by default when in batch mode.
672 set style sources [on|off]
674 Enable or disable source code styling. Source code styling is
675 enabled by default, but only takes effect if styling in general is
676 enabled, and if GDB was linked with GNU Source Highlight.
678 set style filename foreground COLOR
679 set style filename background COLOR
680 set style filename intensity VALUE
681 Control the styling of file names.
683 set style function foreground COLOR
684 set style function background COLOR
685 set style function intensity VALUE
686 Control the styling of function names.
688 set style variable foreground COLOR
689 set style variable background COLOR
690 set style variable intensity VALUE
691 Control the styling of variable names.
693 set style address foreground COLOR
694 set style address background COLOR
695 set style address intensity VALUE
696 Control the styling of addresses.
700 ** The '-data-disassemble' MI command now accepts an '-a' option to
701 disassemble the whole function surrounding the given program
702 counter value or function name. Support for this feature can be
703 verified by using the "-list-features" command, which should
704 contain "data-disassemble-a-option".
706 ** Command responses and notifications that include a frame now include
707 the frame's architecture in a new "arch" attribute.
709 * New native configurations
711 GNU/Linux/RISC-V riscv*-*-linux*
712 FreeBSD/riscv riscv*-*-freebsd*
716 GNU/Linux/RISC-V riscv*-*-linux*
718 CSKY GNU/LINUX csky*-*-linux
719 FreeBSD/riscv riscv*-*-freebsd*
721 GNU/Linux/OpenRISC or1k*-*-linux*
725 GDB no longer supports native debugging on versions of MS-Windows
730 ** GDB no longer supports Python versions less than 2.6.
732 ** The gdb.Inferior type has a new 'progspace' property, which is the program
733 space associated to that inferior.
735 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
736 of objfiles associated to that program space.
738 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
739 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
742 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
743 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
744 correct and did not work properly.
746 ** The gdb.Value type has a new constructor, which is used to construct a
747 gdb.Value from a Python buffer object and a gdb.Type.
753 Enable or disable the undefined behavior sanitizer. This is
754 disabled by default, but passing --enable-ubsan=yes or
755 --enable-ubsan=auto to configure will enable it. Enabling this can
756 cause a performance penalty. The undefined behavior sanitizer was
757 first introduced in GCC 4.9.
759 *** Changes in GDB 8.2
761 * The 'set disassembler-options' command now supports specifying options
764 * The 'symbol-file' command now accepts an '-o' option to add a relative
765 offset to all sections.
767 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
768 a relative offset to all sections, but it allows to override the load
769 address of individual sections using '-s'.
771 * The 'add-symbol-file' command no longer requires the second argument
772 (address of the text section).
774 * The endianness used with the 'set endian auto' mode in the absence of
775 an executable selected for debugging is now the last endianness chosen
776 either by one of the 'set endian big' and 'set endian little' commands
777 or by inferring from the last executable used, rather than the startup
780 * The pager now allows a "c" response, meaning to disable the pager
781 for the rest of the current command.
783 * The commands 'info variables/functions/types' now show the source line
784 numbers of symbol definitions when available.
786 * 'info proc' now works on running processes on FreeBSD systems and core
787 files created on FreeBSD systems.
789 * C expressions can now use _Alignof, and C++ expressions can now use
792 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
793 the vector length while the process is running.
799 Control display of debugging info regarding the FreeBSD native target.
801 set|show varsize-limit
802 This new setting allows the user to control the maximum size of Ada
803 objects being printed when those objects have a variable type,
804 instead of that maximum size being hardcoded to 65536 bytes.
806 set|show record btrace cpu
807 Controls the processor to be used for enabling errata workarounds for
810 maint check libthread-db
811 Run integrity checks on the current inferior's thread debugging
814 maint set check-libthread-db (on|off)
815 maint show check-libthread-db
816 Control whether to run integrity checks on inferior specific thread
817 debugging libraries as they are loaded. The default is not to
822 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
824 ** The commands attached to a breakpoint can be set by assigning to
825 the breakpoint's "commands" field.
827 ** gdb.execute can now execute multi-line gdb commands.
829 ** The new functions gdb.convenience_variable and
830 gdb.set_convenience_variable can be used to get and set the value
831 of convenience variables.
833 ** A gdb.Parameter will no longer print the "set" help text on an
834 ordinary "set"; instead by default a "set" will be silent unless
835 the get_set_string method returns a non-empty string.
839 RiscV ELF riscv*-*-elf
841 * Removed targets and native configurations
843 m88k running OpenBSD m88*-*-openbsd*
844 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
845 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
846 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
848 * Aarch64/Linux hardware watchpoints improvements
850 Hardware watchpoints on unaligned addresses are now properly
851 supported when running Linux kernel 4.10 or higher: read and access
852 watchpoints are no longer spuriously missed, and all watchpoints
853 lengths between 1 and 8 bytes are supported. On older kernels,
854 watchpoints set on unaligned addresses are no longer missed, with
855 the tradeoff that there is a possibility of false hits being
860 --enable-codesign=CERT
861 This can be used to invoke "codesign -s CERT" after building gdb.
862 This option is useful on macOS, where code signing is required for
863 gdb to work properly.
865 --disable-gdbcli has been removed
866 This is now silently accepted, but does nothing.
868 *** Changes in GDB 8.1
870 * GDB now supports dynamically creating arbitrary register groups specified
871 in XML target descriptions. This allows for finer grain grouping of
872 registers on systems with a large amount of registers.
874 * The 'ptype' command now accepts a '/o' flag, which prints the
875 offsets and sizes of fields in a struct, like the pahole(1) tool.
877 * New "--readnever" command line option instructs GDB to not read each
878 symbol file's symbolic debug information. This makes startup faster
879 but at the expense of not being able to perform symbolic debugging.
880 This option is intended for use cases where symbolic debugging will
881 not be used, e.g., when you only need to dump the debuggee's core.
883 * GDB now uses the GNU MPFR library, if available, to emulate target
884 floating-point arithmetic during expression evaluation when the target
885 uses different floating-point formats than the host. At least version
886 3.1 of GNU MPFR is required.
888 * GDB now supports access to the guarded-storage-control registers and the
889 software-based guarded-storage broadcast control registers on IBM z14.
891 * On Unix systems, GDB now supports transmitting environment variables
892 that are to be set or unset to GDBserver. These variables will
893 affect the environment to be passed to the remote inferior.
895 To inform GDB of environment variables that are to be transmitted to
896 GDBserver, use the "set environment" command. Only user set
897 environment variables are sent to GDBserver.
899 To inform GDB of environment variables that are to be unset before
900 the remote inferior is started by the GDBserver, use the "unset
901 environment" command.
903 * Completion improvements
905 ** GDB can now complete function parameters in linespecs and
906 explicit locations without quoting. When setting breakpoints,
907 quoting around functions names to help with TAB-completion is
908 generally no longer necessary. For example, this now completes
911 (gdb) b function(in[TAB]
912 (gdb) b function(int)
914 Related, GDB is no longer confused with completing functions in
915 C++ anonymous namespaces:
918 (gdb) b (anonymous namespace)::[TAB][TAB]
919 (anonymous namespace)::a_function()
920 (anonymous namespace)::b_function()
922 ** GDB now has much improved linespec and explicit locations TAB
923 completion support, that better understands what you're
924 completing and offers better suggestions. For example, GDB no
925 longer offers data symbols as possible completions when you're
926 setting a breakpoint.
928 ** GDB now TAB-completes label symbol names.
930 ** The "complete" command now mimics TAB completion accurately.
932 * New command line options (gcore)
935 Dump all memory mappings.
937 * Breakpoints on C++ functions are now set on all scopes by default
939 By default, breakpoints on functions/methods are now interpreted as
940 specifying all functions with the given name ignoring missing
941 leading scopes (namespaces and classes).
943 For example, assuming a C++ program with symbols named:
948 both commands "break func()" and "break B::func()" set a breakpoint
951 You can use the new flag "-qualified" to override this. This makes
952 GDB interpret the specified function name as a complete
953 fully-qualified name instead. For example, using the same C++
954 program, the "break -q B::func" command sets a breakpoint on
955 "B::func", only. A parameter has been added to the Python
956 gdb.Breakpoint constructor to achieve the same result when creating
957 a breakpoint from Python.
959 * Breakpoints on functions marked with C++ ABI tags
961 GDB can now set breakpoints on functions marked with C++ ABI tags
962 (e.g., [abi:cxx11]). See here for a description of ABI tags:
963 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
965 Functions with a C++11 abi tag are demangled/displayed like this:
967 function[abi:cxx11](int)
970 You can now set a breakpoint on such functions simply as if they had
973 (gdb) b function(int)
975 Or if you need to disambiguate between tags, like:
977 (gdb) b function[abi:other_tag](int)
979 Tab completion was adjusted accordingly as well.
983 ** New events gdb.new_inferior, gdb.inferior_deleted, and
984 gdb.new_thread are emitted. See the manual for further
985 description of these.
987 ** A new function, "gdb.rbreak" has been added to the Python API.
988 This function allows the setting of a large number of breakpoints
989 via a regex pattern in Python. See the manual for further details.
991 ** Python breakpoints can now accept explicit locations. See the
992 manual for a further description of this feature.
995 * New features in the GDB remote stub, GDBserver
997 ** GDBserver is now able to start inferior processes with a
998 specified initial working directory.
1000 The user can set the desired working directory to be used from
1001 GDB using the new "set cwd" command.
1003 ** New "--selftest" command line option runs some GDBserver self
1004 tests. These self tests are disabled in releases.
1006 ** On Unix systems, GDBserver now does globbing expansion and variable
1007 substitution in inferior command line arguments.
1009 This is done by starting inferiors using a shell, like GDB does.
1010 See "set startup-with-shell" in the user manual for how to disable
1011 this from GDB when using "target extended-remote". When using
1012 "target remote", you can disable the startup with shell by using the
1013 new "--no-startup-with-shell" GDBserver command line option.
1015 ** On Unix systems, GDBserver now supports receiving environment
1016 variables that are to be set or unset from GDB. These variables
1017 will affect the environment to be passed to the inferior.
1019 * When catching an Ada exception raised with a message, GDB now prints
1020 the message in the catchpoint hit notification. In GDB/MI mode, that
1021 information is provided as an extra field named "exception-message"
1022 in the *stopped notification.
1024 * Trait objects can now be inspected When debugging Rust code. This
1025 requires compiler support which will appear in Rust 1.24.
1027 * New remote packets
1029 QEnvironmentHexEncoded
1030 Inform GDBserver of an environment variable that is to be passed to
1031 the inferior when starting it.
1034 Inform GDBserver of an environment variable that is to be unset
1035 before starting the remote inferior.
1038 Inform GDBserver that the environment should be reset (i.e.,
1039 user-set environment variables should be unset).
1042 Indicates whether the inferior must be started with a shell or not.
1045 Tell GDBserver that the inferior to be started should use a specific
1048 * The "maintenance print c-tdesc" command now takes an optional
1049 argument which is the file name of XML target description.
1051 * The "maintenance selftest" command now takes an optional argument to
1052 filter the tests to be run.
1054 * The "enable", and "disable" commands now accept a range of
1055 breakpoint locations, e.g. "enable 1.3-5".
1060 Set and show the current working directory for the inferior.
1062 set|show compile-gcc
1063 Set and show compilation command used for compiling and injecting code
1064 with the 'compile' commands.
1066 set debug separate-debug-file
1067 show debug separate-debug-file
1068 Control the display of debug output about separate debug file search.
1070 set dump-excluded-mappings
1071 show dump-excluded-mappings
1072 Control whether mappings marked with the VM_DONTDUMP flag should be
1073 dumped when generating a core file.
1075 maint info selftests
1076 List the registered selftests.
1079 Start the debugged program stopping at the first instruction.
1082 Control display of debugging messages related to OpenRISC targets.
1084 set|show print type nested-type-limit
1085 Set and show the limit of nesting level for nested types that the
1086 type printer will show.
1088 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1091 * Safer/improved support for debugging with no debug info
1093 GDB no longer assumes functions with no debug information return
1096 This means that GDB now refuses to call such functions unless you
1097 tell it the function's type, by either casting the call to the
1098 declared return type, or by casting the function to a function
1099 pointer of the right type, and calling that:
1101 (gdb) p getenv ("PATH")
1102 'getenv' has unknown return type; cast the call to its declared return type
1103 (gdb) p (char *) getenv ("PATH")
1104 $1 = 0x7fffffffe "/usr/local/bin:/"...
1105 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1106 $2 = 0x7fffffffe "/usr/local/bin:/"...
1108 Similarly, GDB no longer assumes that global variables with no debug
1109 info have type 'int', and refuses to print the variable's value
1110 unless you tell it the variable's type:
1113 'var' has unknown type; cast it to its declared type
1117 * New native configurations
1119 FreeBSD/aarch64 aarch64*-*-freebsd*
1120 FreeBSD/arm arm*-*-freebsd*
1124 FreeBSD/aarch64 aarch64*-*-freebsd*
1125 FreeBSD/arm arm*-*-freebsd*
1126 OpenRISC ELF or1k*-*-elf
1128 * Removed targets and native configurations
1130 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1132 *** Changes in GDB 8.0
1134 * GDB now supports access to the PKU register on GNU/Linux. The register is
1135 added by the Memory Protection Keys for Userspace feature which will be
1136 available in future Intel CPUs.
1138 * GDB now supports C++11 rvalue references.
1142 ** New functions to start, stop and access a running btrace recording.
1143 ** Rvalue references are now supported in gdb.Type.
1145 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1148 * Building GDB and GDBserver now requires a C++11 compiler.
1150 For example, GCC 4.8 or later.
1152 It is no longer possible to build GDB or GDBserver with a C
1153 compiler. The --disable-build-with-cxx configure option has been
1156 * Building GDB and GDBserver now requires GNU make >= 3.81.
1158 It is no longer supported to build GDB or GDBserver with another
1159 implementation of the make program or an earlier version of GNU make.
1161 * Native debugging on MS-Windows supports command-line redirection
1163 Command-line arguments used for starting programs on MS-Windows can
1164 now include redirection symbols supported by native Windows shells,
1165 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1166 as "run", "start", and "set args", as well as the corresponding MI
1169 * Support for thread names on MS-Windows.
1171 GDB now catches and handles the special exception that programs
1172 running on MS-Windows use to assign names to threads in the
1175 * Support for Java programs compiled with gcj has been removed.
1177 * User commands now accept an unlimited number of arguments.
1178 Previously, only up to 10 was accepted.
1180 * The "eval" command now expands user-defined command arguments.
1182 This makes it easier to process a variable number of arguments:
1187 eval "print $arg%d", $i
1192 * Target descriptions can now describe registers for sparc32 and sparc64.
1194 * GDB now supports DWARF version 5 (debug information format).
1195 Its .debug_names index is not yet supported.
1197 * New native configurations
1199 FreeBSD/mips mips*-*-freebsd
1203 Synopsys ARC arc*-*-elf32
1204 FreeBSD/mips mips*-*-freebsd
1206 * Removed targets and native configurations
1208 Alpha running FreeBSD alpha*-*-freebsd*
1209 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1214 Erases all the flash memory regions reported by the target.
1216 maint print arc arc-instruction address
1217 Print internal disassembler information about instruction at a given address.
1221 set disassembler-options
1222 show disassembler-options
1223 Controls the passing of target specific information to the disassembler.
1224 If it is necessary to specify more than one disassembler option then
1225 multiple options can be placed together into a comma separated list.
1226 The default value is the empty string. Currently, the only supported
1227 targets are ARM, PowerPC and S/390.
1232 Erases all the flash memory regions reported by the target. This is
1233 equivalent to the CLI command flash-erase.
1235 -file-list-shared-libraries
1236 List the shared libraries in the program. This is
1237 equivalent to the CLI command "info shared".
1240 Catchpoints stopping the program when Ada exceptions are
1241 handled. This is equivalent to the CLI command "catch handlers".
1243 *** Changes in GDB 7.12
1245 * GDB and GDBserver now build with a C++ compiler by default.
1247 The --enable-build-with-cxx configure option is now enabled by
1248 default. One must now explicitly configure with
1249 --disable-build-with-cxx in order to build with a C compiler. This
1250 option will be removed in a future release.
1252 * GDBserver now supports recording btrace without maintaining an active
1255 * GDB now supports a negative repeat count in the 'x' command to examine
1256 memory backward from the given address. For example:
1259 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1260 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1261 (gdb) x/-5i 0x0000000000400580
1262 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1263 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1264 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1265 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1266 0x40057b <main(int, char**)+25>:
1267 callq 0x400536 <Func1(int, char const*)>
1269 * Fortran: Support structures with fields of dynamic types and
1270 arrays of dynamic types.
1272 * The symbol dumping maintenance commands have new syntax.
1273 maint print symbols [-pc address] [--] [filename]
1274 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1275 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1276 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1277 maint print msymbols [-objfile objfile] [--] [filename]
1279 * GDB now supports multibit bitfields and enums in target register
1282 * New Python-based convenience function $_as_string(val), which returns
1283 the textual representation of a value. This function is especially
1284 useful to obtain the text label of an enum value.
1286 * Intel MPX bound violation handling.
1288 Segmentation faults caused by a Intel MPX boundary violation
1289 now display the kind of violation (upper or lower), the memory
1290 address accessed and the memory bounds, along with the usual
1291 signal received and code location.
1295 Program received signal SIGSEGV, Segmentation fault
1296 Upper bound violation while accessing address 0x7fffffffc3b3
1297 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1298 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1300 * Rust language support.
1301 GDB now supports debugging programs written in the Rust programming
1302 language. See https://www.rust-lang.org/ for more information about
1305 * Support for running interpreters on specified input/output devices
1307 GDB now supports a new mechanism that allows frontends to provide
1308 fully featured GDB console views, as a better alternative to
1309 building such views on top of the "-interpreter-exec console"
1310 command. See the new "new-ui" command below. With that command,
1311 frontends can now start GDB in the traditional command-line mode
1312 running in an embedded terminal emulator widget, and create a
1313 separate MI interpreter running on a specified i/o device. In this
1314 way, GDB handles line editing, history, tab completion, etc. in the
1315 console all by itself, and the GUI uses the separate MI interpreter
1316 for its own control and synchronization, invisible to the command
1319 * The "catch syscall" command catches groups of related syscalls.
1321 The "catch syscall" command now supports catching a group of related
1322 syscalls using the 'group:' or 'g:' prefix.
1327 skip -gfile file-glob-pattern
1328 skip -function function
1329 skip -rfunction regular-expression
1330 A generalized form of the skip command, with new support for
1331 glob-style file names and regular expressions for function names.
1332 Additionally, a file spec and a function spec may now be combined.
1334 maint info line-table REGEXP
1335 Display the contents of GDB's internal line table data struture.
1338 Run any GDB unit tests that were compiled in.
1341 Start a new user interface instance running INTERP as interpreter,
1342 using the TTY file for input/output.
1346 ** gdb.Breakpoint objects have a new attribute "pending", which
1347 indicates whether the breakpoint is pending.
1348 ** Three new breakpoint-related events have been added:
1349 gdb.breakpoint_created, gdb.breakpoint_modified, and
1350 gdb.breakpoint_deleted.
1352 signal-event EVENTID
1353 Signal ("set") the given MS-Windows event object. This is used in
1354 conjunction with the Windows JIT debugging (AeDebug) support, where
1355 the OS suspends a crashing process until a debugger can attach to
1356 it. Resuming the crashing process, in order to debug it, is done by
1357 signalling an event.
1359 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1360 was added in GDBserver, including JIT compiling fast tracepoint's
1361 conditional expression bytecode into native code.
1363 * Support for various remote target protocols and ROM monitors has
1366 target m32rsdi Remote M32R debugging over SDI
1367 target mips MIPS remote debugging protocol
1368 target pmon PMON ROM monitor
1369 target ddb NEC's DDB variant of PMON for Vr4300
1370 target rockhopper NEC RockHopper variant of PMON
1371 target lsi LSI variant of PMO
1373 * Support for tracepoints and fast tracepoints on powerpc-linux,
1374 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1375 including JIT compiling fast tracepoint's conditional expression
1376 bytecode into native code.
1378 * MI async record =record-started now includes the method and format used for
1379 recording. For example:
1381 =record-started,thread-group="i1",method="btrace",format="bts"
1383 * MI async record =thread-selected now includes the frame field. For example:
1385 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1389 Andes NDS32 nds32*-*-elf
1391 *** Changes in GDB 7.11
1393 * GDB now supports debugging kernel-based threads on FreeBSD.
1395 * Per-inferior thread numbers
1397 Thread numbers are now per inferior instead of global. If you're
1398 debugging multiple inferiors, GDB displays thread IDs using a
1399 qualified INF_NUM.THR_NUM form. For example:
1403 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1404 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1405 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1406 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1408 As consequence, thread numbers as visible in the $_thread
1409 convenience variable and in Python's InferiorThread.num attribute
1410 are no longer unique between inferiors.
1412 GDB now maintains a second thread ID per thread, referred to as the
1413 global thread ID, which is the new equivalent of thread numbers in
1414 previous releases. See also $_gthread below.
1416 For backwards compatibility, MI's thread IDs always refer to global
1419 * Commands that accept thread IDs now accept the qualified
1420 INF_NUM.THR_NUM form as well. For example:
1423 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1426 * In commands that accept a list of thread IDs, you can now refer to
1427 all threads of an inferior using a star wildcard. GDB accepts
1428 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1429 refer to all threads of the current inferior. For example, "info
1432 * You can use "info threads -gid" to display the global thread ID of
1435 * The new convenience variable $_gthread holds the global number of
1438 * The new convenience variable $_inferior holds the number of the
1441 * GDB now displays the ID and name of the thread that hit a breakpoint
1442 or received a signal, if your program is multi-threaded. For
1445 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1446 Thread 1 "main" received signal SIGINT, Interrupt.
1448 * Record btrace now supports non-stop mode.
1450 * Support for tracepoints on aarch64-linux was added in GDBserver.
1452 * The 'record instruction-history' command now indicates speculative execution
1453 when using the Intel Processor Trace recording format.
1455 * GDB now allows users to specify explicit locations, bypassing
1456 the linespec parser. This feature is also available to GDB/MI
1459 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1460 GDB now is able to debug both AArch64 applications and ARM applications
1463 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1464 including JIT compiling fast tracepoint's conditional expression bytecode
1467 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1469 * "info threads", "info inferiors", "info display", "info checkpoints"
1470 and "maint info program-spaces" now list the corresponding items in
1471 ascending ID order, for consistency with all other "info" commands.
1473 * In Ada, the overloads selection menu has been enhanced to display the
1474 parameter types and the return types for the matching overloaded subprograms.
1478 maint set target-non-stop (on|off|auto)
1479 maint show target-non-stop
1480 Control whether GDB targets always operate in non-stop mode even if
1481 "set non-stop" is "off". The default is "auto", meaning non-stop
1482 mode is enabled if supported by the target.
1484 maint set bfd-sharing
1485 maint show bfd-sharing
1486 Control the reuse of bfd objects.
1489 show debug bfd-cache
1490 Control display of debugging info regarding bfd caching.
1494 Control display of debugging info regarding FreeBSD threads.
1496 set remote multiprocess-extensions-packet
1497 show remote multiprocess-extensions-packet
1498 Set/show the use of the remote protocol multiprocess extensions.
1500 set remote thread-events
1501 show remote thread-events
1502 Set/show the use of thread create/exit events.
1504 set ada print-signatures on|off
1505 show ada print-signatures"
1506 Control whether parameter types and return types are displayed in overloads
1507 selection menus. It is activaled (@code{on}) by default.
1511 Controls the maximum size of memory, in bytes, that GDB will
1512 allocate for value contents. Prevents incorrect programs from
1513 causing GDB to allocate overly large buffers. Default is 64k.
1515 * The "disassemble" command accepts a new modifier: /s.
1516 It prints mixed source+disassembly like /m with two differences:
1517 - disassembled instructions are now printed in program order, and
1518 - and source for all relevant files is now printed.
1519 The "/m" option is now considered deprecated: its "source-centric"
1520 output hasn't proved useful in practice.
1522 * The "record instruction-history" command accepts a new modifier: /s.
1523 It behaves exactly like /m and prints mixed source+disassembly.
1525 * The "set scheduler-locking" command supports a new mode "replay".
1526 It behaves like "off" in record mode and like "on" in replay mode.
1528 * Support for various ROM monitors has been removed:
1530 target dbug dBUG ROM monitor for Motorola ColdFire
1531 target picobug Motorola picobug monitor
1532 target dink32 DINK32 ROM monitor for PowerPC
1533 target m32r Renesas M32R/D ROM monitor
1534 target mon2000 mon2000 ROM monitor
1535 target ppcbug PPCBUG ROM monitor for PowerPC
1537 * Support for reading/writing memory and extracting values on architectures
1538 whose memory is addressable in units of any integral multiple of 8 bits.
1541 Allows to break when an Ada exception is handled.
1543 * New remote packets
1546 Indicates that an exec system call was executed.
1548 exec-events feature in qSupported
1549 The qSupported packet allows GDB to request support for exec
1550 events using the new 'gdbfeature' exec-event, and the qSupported
1551 response can contain the corresponding 'stubfeature'. Set and
1552 show commands can be used to display whether these features are enabled.
1555 Equivalent to interrupting with the ^C character, but works in
1558 thread created stop reason (T05 create:...)
1559 Indicates that the thread was just created and is stopped at entry.
1561 thread exit stop reply (w exitcode;tid)
1562 Indicates that the thread has terminated.
1565 Enables/disables thread create and exit event reporting. For
1566 example, this is used in non-stop mode when GDB stops a set of
1567 threads and synchronously waits for the their corresponding stop
1568 replies. Without exit events, if one of the threads exits, GDB
1569 would hang forever not knowing that it should no longer expect a
1570 stop for that same thread.
1573 Indicates that there are no resumed threads left in the target (all
1574 threads are stopped). The remote stub reports support for this stop
1575 reply to GDB's qSupported query.
1578 Enables/disables catching syscalls from the inferior process.
1579 The remote stub reports support for this packet to GDB's qSupported query.
1581 syscall_entry stop reason
1582 Indicates that a syscall was just called.
1584 syscall_return stop reason
1585 Indicates that a syscall just returned.
1587 * Extended-remote exec events
1589 ** GDB now has support for exec events on extended-remote Linux targets.
1590 For such targets with Linux kernels 2.5.46 and later, this enables
1591 follow-exec-mode and exec catchpoints.
1593 set remote exec-event-feature-packet
1594 show remote exec-event-feature-packet
1595 Set/show the use of the remote exec event feature.
1597 * Thread names in remote protocol
1599 The reply to qXfer:threads:read may now include a name attribute for each
1602 * Target remote mode fork and exec events
1604 ** GDB now has support for fork and exec events on target remote mode
1605 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1606 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1607 fork and exec catchpoints.
1609 * Remote syscall events
1611 ** GDB now has support for catch syscall on remote Linux targets,
1612 currently enabled on x86/x86_64 architectures.
1614 set remote catch-syscall-packet
1615 show remote catch-syscall-packet
1616 Set/show the use of the remote catch syscall feature.
1620 ** The -var-set-format command now accepts the zero-hexadecimal
1621 format. It outputs data in hexadecimal format with zero-padding on the
1626 ** gdb.InferiorThread objects have a new attribute "global_num",
1627 which refers to the thread's global thread ID. The existing
1628 "num" attribute now refers to the thread's per-inferior number.
1629 See "Per-inferior thread numbers" above.
1630 ** gdb.InferiorThread objects have a new attribute "inferior", which
1631 is the Inferior object the thread belongs to.
1633 *** Changes in GDB 7.10
1635 * Support for process record-replay and reverse debugging on aarch64*-linux*
1636 targets has been added. GDB now supports recording of A64 instruction set
1637 including advance SIMD instructions.
1639 * Support for Sun's version of the "stabs" debug file format has been removed.
1641 * GDB now honors the content of the file /proc/PID/coredump_filter
1642 (PID is the process ID) on GNU/Linux systems. This file can be used
1643 to specify the types of memory mappings that will be included in a
1644 corefile. For more information, please refer to the manual page of
1645 "core(5)". GDB also has a new command: "set use-coredump-filter
1646 on|off". It allows to set whether GDB will read the content of the
1647 /proc/PID/coredump_filter file when generating a corefile.
1649 * The "info os" command on GNU/Linux can now display information on
1651 "info os cpus" Listing of all cpus/cores on the system
1653 * GDB has two new commands: "set serial parity odd|even|none" and
1654 "show serial parity". These allows to set or show parity for the
1657 * The "info source" command now displays the producer string if it was
1658 present in the debug info. This typically includes the compiler version
1659 and may include things like its command line arguments.
1661 * The "info dll", an alias of the "info sharedlibrary" command,
1662 is now available on all platforms.
1664 * Directory names supplied to the "set sysroot" commands may be
1665 prefixed with "target:" to tell GDB to access shared libraries from
1666 the target system, be it local or remote. This replaces the prefix
1667 "remote:". The default sysroot has been changed from "" to
1668 "target:". "remote:" is automatically converted to "target:" for
1669 backward compatibility.
1671 * The system root specified by "set sysroot" will be prepended to the
1672 filename of the main executable (if reported to GDB as absolute by
1673 the operating system) when starting processes remotely, and when
1674 attaching to already-running local or remote processes.
1676 * GDB now supports automatic location and retrieval of executable
1677 files from remote targets. Remote debugging can now be initiated
1678 using only a "target remote" or "target extended-remote" command
1679 (no "set sysroot" or "file" commands are required). See "New remote
1682 * The "dump" command now supports verilog hex format.
1684 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1686 * On GNU/Linux, GDB and gdbserver are now able to access executable
1687 and shared library files without a "set sysroot" command when
1688 attaching to processes running in different mount namespaces from
1689 the debugger. This makes it possible to attach to processes in
1690 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1691 See "New remote packets" below.
1693 * The "tui reg" command now provides completion for all of the
1694 available register groups, including target specific groups.
1696 * The HISTSIZE environment variable is no longer read when determining
1697 the size of GDB's command history. GDB now instead reads the dedicated
1698 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1699 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1704 ** Memory ports can now be unbuffered.
1708 ** gdb.Objfile objects have a new attribute "username",
1709 which is the name of the objfile as specified by the user,
1710 without, for example, resolving symlinks.
1711 ** You can now write frame unwinders in Python.
1712 ** gdb.Type objects have a new method "optimized_out",
1713 returning optimized out gdb.Value instance of this type.
1714 ** gdb.Value objects have new methods "reference_value" and
1715 "const_value" which return a reference to the value and a
1716 "const" version of the value respectively.
1720 maint print symbol-cache
1721 Print the contents of the symbol cache.
1723 maint print symbol-cache-statistics
1724 Print statistics of symbol cache usage.
1726 maint flush-symbol-cache
1727 Flush the contents of the symbol cache.
1731 Start branch trace recording using Branch Trace Store (BTS) format.
1734 Evaluate expression by using the compiler and print result.
1738 Explicit commands for enabling and disabling tui mode.
1741 set mpx bound on i386 and amd64
1742 Support for bound table investigation on Intel MPX enabled applications.
1746 Start branch trace recording using Intel Processor Trace format.
1749 Print information about branch tracing internals.
1751 maint btrace packet-history
1752 Print the raw branch tracing data.
1754 maint btrace clear-packet-history
1755 Discard the stored raw branch tracing data.
1758 Discard all branch tracing data. It will be fetched and processed
1759 anew by the next "record" command.
1764 Renamed from "set debug dwarf2-die".
1765 show debug dwarf-die
1766 Renamed from "show debug dwarf2-die".
1768 set debug dwarf-read
1769 Renamed from "set debug dwarf2-read".
1770 show debug dwarf-read
1771 Renamed from "show debug dwarf2-read".
1773 maint set dwarf always-disassemble
1774 Renamed from "maint set dwarf2 always-disassemble".
1775 maint show dwarf always-disassemble
1776 Renamed from "maint show dwarf2 always-disassemble".
1778 maint set dwarf max-cache-age
1779 Renamed from "maint set dwarf2 max-cache-age".
1780 maint show dwarf max-cache-age
1781 Renamed from "maint show dwarf2 max-cache-age".
1783 set debug dwarf-line
1784 show debug dwarf-line
1785 Control display of debugging info regarding DWARF line processing.
1788 show max-completions
1789 Set the maximum number of candidates to be considered during
1790 completion. The default value is 200. This limit allows GDB
1791 to avoid generating large completion lists, the computation of
1792 which can cause the debugger to become temporarily unresponsive.
1794 set history remove-duplicates
1795 show history remove-duplicates
1796 Control the removal of duplicate history entries.
1798 maint set symbol-cache-size
1799 maint show symbol-cache-size
1800 Control the size of the symbol cache.
1802 set|show record btrace bts buffer-size
1803 Set and show the size of the ring buffer used for branch tracing in
1805 The obtained size may differ from the requested size. Use "info
1806 record" to see the obtained buffer size.
1808 set debug linux-namespaces
1809 show debug linux-namespaces
1810 Control display of debugging info regarding Linux namespaces.
1812 set|show record btrace pt buffer-size
1813 Set and show the size of the ring buffer used for branch tracing in
1814 Intel Processor Trace format.
1815 The obtained size may differ from the requested size. Use "info
1816 record" to see the obtained buffer size.
1818 maint set|show btrace pt skip-pad
1819 Set and show whether PAD packets are skipped when computing the
1822 * The command 'thread apply all' can now support new option '-ascending'
1823 to call its specified command for all threads in ascending order.
1825 * Python/Guile scripting
1827 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1828 special section named `.debug_gdb_scripts'.
1830 * New remote packets
1832 qXfer:btrace-conf:read
1833 Return the branch trace configuration for the current thread.
1835 Qbtrace-conf:bts:size
1836 Set the requested ring buffer size for branch tracing in BTS format.
1839 Enable Intel Procesor Trace-based branch tracing for the current
1840 process. The remote stub reports support for this packet to GDB's
1843 Qbtrace-conf:pt:size
1844 Set the requested ring buffer size for branch tracing in Intel Processor
1848 Indicates a memory breakpoint instruction was executed, irrespective
1849 of whether it was GDB that planted the breakpoint or the breakpoint
1850 is hardcoded in the program. This is required for correct non-stop
1854 Indicates the target stopped for a hardware breakpoint. This is
1855 required for correct non-stop mode operation.
1858 Return information about files on the remote system.
1860 qXfer:exec-file:read
1861 Return the full absolute name of the file that was executed to
1862 create a process running on the remote system.
1865 Select the filesystem on which vFile: operations with filename
1866 arguments will operate. This is required for GDB to be able to
1867 access files on remote targets where the remote stub does not
1868 share a common filesystem with the inferior(s).
1871 Indicates that a fork system call was executed.
1874 Indicates that a vfork system call was executed.
1876 vforkdone stop reason
1877 Indicates that a vfork child of the specified process has executed
1878 an exec or exit, allowing the vfork parent to resume execution.
1880 fork-events and vfork-events features in qSupported
1881 The qSupported packet allows GDB to request support for fork and
1882 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1883 and the qSupported response can contain the corresponding
1884 'stubfeatures'. Set and show commands can be used to display
1885 whether these features are enabled.
1887 * Extended-remote fork events
1889 ** GDB now has support for fork events on extended-remote Linux
1890 targets. For targets with Linux kernels 2.5.60 and later, this
1891 enables follow-fork-mode and detach-on-fork for both fork and
1892 vfork, as well as fork and vfork catchpoints.
1894 * The info record command now shows the recording format and the
1895 branch tracing configuration for the current thread when using
1896 the btrace record target.
1897 For the BTS format, it shows the ring buffer size.
1899 * GDB now has support for DTrace USDT (Userland Static Defined
1900 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1902 * GDB now supports access to vector registers on S/390 GNU/Linux
1905 * Removed command line options
1907 -xdb HP-UX XDB compatibility mode.
1909 * Removed targets and native configurations
1911 HP/PA running HP-UX hppa*-*-hpux*
1912 Itanium running HP-UX ia64-*-hpux*
1914 * New configure options
1917 This configure option allows the user to build GDB with support for
1918 Intel Processor Trace (default: auto). This requires libipt.
1920 --with-libipt-prefix=PATH
1921 Specify the path to the version of libipt that GDB should use.
1922 $PATH/include should contain the intel-pt.h header and
1923 $PATH/lib should contain the libipt.so library.
1925 *** Changes in GDB 7.9.1
1929 ** Xmethods can now specify a result type.
1931 *** Changes in GDB 7.9
1933 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1937 ** You can now access frame registers from Python scripts.
1938 ** New attribute 'producer' for gdb.Symtab objects.
1939 ** gdb.Objfile objects have a new attribute "progspace",
1940 which is the gdb.Progspace object of the containing program space.
1941 ** gdb.Objfile objects have a new attribute "owner".
1942 ** gdb.Objfile objects have a new attribute "build_id",
1943 which is the build ID generated when the file was built.
1944 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1945 ** A new event "gdb.clear_objfiles" has been added, triggered when
1946 selecting a new file to debug.
1947 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1948 ** New function gdb.lookup_objfile.
1950 New events which are triggered when GDB modifies the state of the
1953 ** gdb.events.inferior_call_pre: Function call is about to be made.
1954 ** gdb.events.inferior_call_post: Function call has just been made.
1955 ** gdb.events.memory_changed: A memory location has been altered.
1956 ** gdb.events.register_changed: A register has been altered.
1958 * New Python-based convenience functions:
1960 ** $_caller_is(name [, number_of_frames])
1961 ** $_caller_matches(regexp [, number_of_frames])
1962 ** $_any_caller_is(name [, number_of_frames])
1963 ** $_any_caller_matches(regexp [, number_of_frames])
1965 * GDB now supports the compilation and injection of source code into
1966 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1967 to compile the source code to object code, and if successful, inject
1968 and execute that code within the current context of the inferior.
1969 Currently the C language is supported. The commands used to
1970 interface with this new feature are:
1972 compile code [-raw|-r] [--] [source code]
1973 compile file [-raw|-r] filename
1977 demangle [-l language] [--] name
1978 Demangle "name" in the specified language, or the current language
1979 if elided. This command is renamed from the "maint demangle" command.
1980 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1981 as "maint demangler-warning".
1983 queue-signal signal-name-or-number
1984 Queue a signal to be delivered to the thread when it is resumed.
1986 add-auto-load-scripts-directory directory
1987 Add entries to the list of directories from which to load auto-loaded
1990 maint print user-registers
1991 List all currently available "user" registers.
1993 compile code [-r|-raw] [--] [source code]
1994 Compile, inject, and execute in the inferior the executable object
1995 code produced by compiling the provided source code.
1997 compile file [-r|-raw] filename
1998 Compile and inject into the inferior the executable object code
1999 produced by compiling the source code stored in the filename
2002 * On resume, GDB now always passes the signal the program had stopped
2003 for to the thread the signal was sent to, even if the user changed
2004 threads before resuming. Previously GDB would often (but not
2005 always) deliver the signal to the thread that happens to be current
2008 * Conversely, the "signal" command now consistently delivers the
2009 requested signal to the current thread. GDB now asks for
2010 confirmation if the program had stopped for a signal and the user
2011 switched threads meanwhile.
2013 * "breakpoint always-inserted" modes "off" and "auto" merged.
2015 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2016 won't remove breakpoints from the target until all threads stop,
2017 even in non-stop mode. The "auto" mode has been removed, and "off"
2018 is now the default mode.
2022 set debug symbol-lookup
2023 show debug symbol-lookup
2024 Control display of debugging info regarding symbol lookup.
2028 ** The -list-thread-groups command outputs an exit-code field for
2029 inferiors that have exited.
2033 MIPS SDE mips*-sde*-elf*
2037 Support for these obsolete configurations has been removed.
2039 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2040 SGI Irix-5.x mips-*-irix5*
2041 SGI Irix-6.x mips-*-irix6*
2042 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2043 VAX running Ultrix vax-*-ultrix*
2045 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2046 and "assf"), have been removed. Use the "sharedlibrary" command, or
2047 its alias "share", instead.
2049 *** Changes in GDB 7.8
2051 * New command line options
2054 This is an alias for the --data-directory option.
2056 * GDB supports printing and modifying of variable length automatic arrays
2057 as specified in ISO C99.
2059 * The ARM simulator now supports instruction level tracing
2060 with or without disassembly.
2064 GDB now has support for scripting using Guile. Whether this is
2065 available is determined at configure time.
2066 Guile version 2.0 or greater is required.
2067 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2069 * New commands (for set/show, see "New options" below)
2073 Invoke CODE by passing it to the Guile interpreter.
2077 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2079 info auto-load guile-scripts [regexp]
2080 Print the list of automatically loaded Guile scripts.
2082 * The source command is now capable of sourcing Guile scripts.
2083 This feature is dependent on the debugger being built with Guile support.
2087 set print symbol-loading (off|brief|full)
2088 show print symbol-loading
2089 Control whether to print informational messages when loading symbol
2090 information for a file. The default is "full", but when debugging
2091 programs with large numbers of shared libraries the amount of output
2092 becomes less useful.
2094 set guile print-stack (none|message|full)
2095 show guile print-stack
2096 Show a stack trace when an error is encountered in a Guile script.
2098 set auto-load guile-scripts (on|off)
2099 show auto-load guile-scripts
2100 Control auto-loading of Guile script files.
2102 maint ada set ignore-descriptive-types (on|off)
2103 maint ada show ignore-descriptive-types
2104 Control whether the debugger should ignore descriptive types in Ada
2105 programs. The default is not to ignore the descriptive types. See
2106 the user manual for more details on descriptive types and the intended
2107 usage of this option.
2109 set auto-connect-native-target
2111 Control whether GDB is allowed to automatically connect to the
2112 native target for the run, attach, etc. commands when not connected
2113 to any target yet. See also "target native" below.
2115 set record btrace replay-memory-access (read-only|read-write)
2116 show record btrace replay-memory-access
2117 Control what memory accesses are allowed during replay.
2119 maint set target-async (on|off)
2120 maint show target-async
2121 This controls whether GDB targets operate in synchronous or
2122 asynchronous mode. Normally the default is asynchronous, if it is
2123 available; but this can be changed to more easily debug problems
2124 occurring only in synchronous mode.
2126 set mi-async (on|off)
2128 Control whether MI asynchronous mode is preferred. This supersedes
2129 "set target-async" of previous GDB versions.
2131 * "set target-async" is deprecated as a CLI option and is now an alias
2132 for "set mi-async" (only puts MI into async mode).
2134 * Background execution commands (e.g., "c&", "s&", etc.) are now
2135 possible ``out of the box'' if the target supports them. Previously
2136 the user would need to explicitly enable the possibility with the
2137 "set target-async on" command.
2139 * New features in the GDB remote stub, GDBserver
2141 ** New option --debug-format=option1[,option2,...] allows one to add
2142 additional text to each output. At present only timestamps
2143 are supported: --debug-format=timestamps.
2144 Timestamps can also be turned on with the
2145 "monitor set debug-format timestamps" command from GDB.
2147 * The 'record instruction-history' command now starts counting instructions
2148 at one. This also affects the instruction ranges reported by the
2149 'record function-call-history' command when given the /i modifier.
2151 * The command 'record function-call-history' supports a new modifier '/c' to
2152 indent the function names based on their call stack depth.
2153 The fields for the '/i' and '/l' modifier have been reordered.
2154 The source line range is now prefixed with 'at'.
2155 The instruction range is now prefixed with 'inst'.
2156 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2157 "record instruction-history" and "list" commands.
2159 * The ranges given as arguments to the 'record function-call-history' and
2160 'record instruction-history' commands are now inclusive.
2162 * The btrace record target now supports the 'record goto' command.
2163 For locations inside the execution trace, the back trace is computed
2164 based on the information stored in the execution trace.
2166 * The btrace record target supports limited reverse execution and replay.
2167 The target does not record data and therefore does not allow reading
2168 memory or registers.
2170 * The "catch syscall" command now works on s390*-linux* targets.
2172 * The "compare-sections" command is no longer specific to target
2173 remote. It now works with all targets.
2175 * All native targets are now consistently called "native".
2176 Consequently, the "target child", "target GNU", "target djgpp",
2177 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2178 commands have been replaced with "target native". The QNX/NTO port
2179 leaves the "procfs" target in place and adds a "native" target for
2180 consistency with other ports. The impact on users should be minimal
2181 as these commands previously either throwed an error, or were
2182 no-ops. The target's name is visible in the output of the following
2183 commands: "help target", "info target", "info files", "maint print
2186 * The "target native" command now connects to the native target. This
2187 can be used to launch native programs even when "set
2188 auto-connect-native-target" is set to off.
2190 * GDB now supports access to Intel MPX registers on GNU/Linux.
2192 * Support for Intel AVX-512 registers on GNU/Linux.
2193 Support displaying and modifying Intel AVX-512 registers
2194 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2196 * New remote packets
2198 qXfer:btrace:read's annex
2199 The qXfer:btrace:read packet supports a new annex 'delta' to read
2200 branch trace incrementally.
2204 ** Valid Python operations on gdb.Value objects representing
2205 structs/classes invoke the corresponding overloaded operators if
2207 ** New `Xmethods' feature in the Python API. Xmethods are
2208 additional methods or replacements for existing methods of a C++
2209 class. This feature is useful for those cases where a method
2210 defined in C++ source code could be inlined or optimized out by
2211 the compiler, making it unavailable to GDB.
2214 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2216 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2217 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2218 its alias "share", instead.
2220 * The commands "set remotebaud" and "show remotebaud" are no longer
2221 supported. Use "set serial baud" and "show serial baud" (respectively)
2226 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2227 target-async". The latter is left as a deprecated alias of the
2228 former for backward compatibility. If the target supports it,
2229 CLI background execution commands are now always possible by
2230 default, independently of whether the frontend stated a
2231 preference for asynchronous execution with "-gdb-set mi-async".
2232 Previously "-gdb-set target-async off" affected both MI execution
2233 commands and CLI execution commands.
2235 *** Changes in GDB 7.7
2237 * Improved support for process record-replay and reverse debugging on
2238 arm*-linux* targets. Support for thumb32 and syscall instruction
2239 recording has been added.
2241 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2243 * GDB now supports Fission DWP file format version 2.
2244 http://gcc.gnu.org/wiki/DebugFission
2246 * New convenience function "$_isvoid", to check whether an expression
2247 is void. A void expression is an expression where the type of the
2248 result is "void". For example, some convenience variables may be
2249 "void" when evaluated (e.g., "$_exitcode" before the execution of
2250 the program being debugged; or an undefined convenience variable).
2251 Another example, when calling a function whose return type is
2254 * The "maintenance print objfiles" command now takes an optional regexp.
2256 * The "catch syscall" command now works on arm*-linux* targets.
2258 * GDB now consistently shows "<not saved>" when printing values of
2259 registers the debug info indicates have not been saved in the frame
2260 and there's nowhere to retrieve them from
2261 (callee-saved/call-clobbered registers):
2266 (gdb) info registers rax
2269 Before, the former would print "<optimized out>", and the latter
2270 "*value not available*".
2272 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2277 ** Frame filters and frame decorators have been added.
2278 ** Temporary breakpoints are now supported.
2279 ** Line tables representation has been added.
2280 ** New attribute 'parent_type' for gdb.Field objects.
2281 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2282 ** New attribute 'name' for gdb.Type objects.
2286 Nios II ELF nios2*-*-elf
2287 Nios II GNU/Linux nios2*-*-linux
2288 Texas Instruments MSP430 msp430*-*-elf
2290 * Removed native configurations
2292 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2293 been removed. ELF variants of these configurations are kept supported.
2295 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2296 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2297 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2298 i[34567]86-*-openbsd3.[0-3]
2299 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2300 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2301 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2305 Like "catch throw", but catches a re-thrown exception.
2306 maint check-psymtabs
2307 Renamed from old "maint check-symtabs".
2309 Perform consistency checks on symtabs.
2310 maint expand-symtabs
2311 Expand symtabs matching an optional regexp.
2314 Display the details of GDB configure-time options.
2316 maint set|show per-command
2317 maint set|show per-command space
2318 maint set|show per-command time
2319 maint set|show per-command symtab
2320 Enable display of per-command gdb resource usage.
2322 remove-symbol-file FILENAME
2323 remove-symbol-file -a ADDRESS
2324 Remove a symbol file added via add-symbol-file. The file to remove
2325 can be identified by its filename or by an address that lies within
2326 the boundaries of this symbol file in memory.
2329 info exceptions REGEXP
2330 Display the list of Ada exceptions defined in the program being
2331 debugged. If provided, only the exceptions whose names match REGEXP
2336 set debug symfile off|on
2338 Control display of debugging info regarding reading symbol files and
2339 symbol tables within those files
2341 set print raw frame-arguments
2342 show print raw frame-arguments
2343 Set/show whether to print frame arguments in raw mode,
2344 disregarding any defined pretty-printers.
2346 set remote trace-status-packet
2347 show remote trace-status-packet
2348 Set/show the use of remote protocol qTStatus packet.
2352 Control display of debugging messages related to Nios II targets.
2356 Control whether target-assisted range stepping is enabled.
2358 set startup-with-shell
2359 show startup-with-shell
2360 Specifies whether Unix child processes are started via a shell or
2365 Use the target memory cache for accesses to the code segment. This
2366 improves performance of remote debugging (particularly disassembly).
2368 * You can now use a literal value 'unlimited' for options that
2369 interpret 0 or -1 as meaning "unlimited". E.g., "set
2370 trace-buffer-size unlimited" is now an alias for "set
2371 trace-buffer-size -1" and "set height unlimited" is now an alias for
2374 * The "set debug symtab-create" debugging option of GDB has been changed to
2375 accept a verbosity level. 0 means "off", 1 provides basic debugging
2376 output, and values of 2 or greater provides more verbose output.
2378 * New command-line options
2380 Display the details of GDB configure-time options.
2382 * The command 'tsave' can now support new option '-ctf' to save trace
2383 buffer in Common Trace Format.
2385 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2388 * GDB now implements the the C++ 'typeid' operator.
2390 * The new convenience variable $_exception holds the exception being
2391 thrown or caught at an exception-related catchpoint.
2393 * The exception-related catchpoints, like "catch throw", now accept a
2394 regular expression which can be used to filter exceptions by type.
2396 * The new convenience variable $_exitsignal is automatically set to
2397 the terminating signal number when the program being debugged dies
2398 due to an uncaught signal.
2402 ** All MI commands now accept an optional "--language" option.
2403 Support for this feature can be verified by using the "-list-features"
2404 command, which should contain "language-option".
2406 ** The new command -info-gdb-mi-command allows the user to determine
2407 whether a GDB/MI command is supported or not.
2409 ** The "^error" result record returned when trying to execute an undefined
2410 GDB/MI command now provides a variable named "code" whose content is the
2411 "undefined-command" error code. Support for this feature can be verified
2412 by using the "-list-features" command, which should contain
2413 "undefined-command-error-code".
2415 ** The -trace-save MI command can optionally save trace buffer in Common
2418 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2420 ** The command -data-list-register-values now accepts an optional
2421 "--skip-unavailable" option. When used, only the available registers
2424 ** The new command -trace-frame-collected dumps collected variables,
2425 computed expressions, tvars, memory and registers in a traceframe.
2427 ** The commands -stack-list-locals, -stack-list-arguments and
2428 -stack-list-variables now accept an option "--skip-unavailable".
2429 When used, only the available locals or arguments are displayed.
2431 ** The -exec-run command now accepts an optional "--start" option.
2432 When used, the command follows the same semantics as the "start"
2433 command, stopping the program's execution at the start of its
2434 main subprogram. Support for this feature can be verified using
2435 the "-list-features" command, which should contain
2436 "exec-run-start-option".
2438 ** The new commands -catch-assert and -catch-exceptions insert
2439 catchpoints stopping the program when Ada exceptions are raised.
2441 ** The new command -info-ada-exceptions provides the equivalent of
2442 the new "info exceptions" command.
2444 * New system-wide configuration scripts
2445 A GDB installation now provides scripts suitable for use as system-wide
2446 configuration scripts for the following systems:
2450 * GDB now supports target-assigned range stepping with remote targets.
2451 This improves the performance of stepping source lines by reducing
2452 the number of control packets from/to GDB. See "New remote packets"
2455 * GDB now understands the element 'tvar' in the XML traceframe info.
2456 It has the id of the collected trace state variables.
2458 * On S/390 targets that provide the transactional-execution feature,
2459 the program interruption transaction diagnostic block (TDB) is now
2460 represented as a number of additional "registers" in GDB.
2462 * New remote packets
2466 The vCont packet supports a new 'r' action, that tells the remote
2467 stub to step through an address range itself, without GDB
2468 involvemement at each single-step.
2470 qXfer:libraries-svr4:read's annex
2471 The previously unused annex of the qXfer:libraries-svr4:read packet
2472 is now used to support passing an argument list. The remote stub
2473 reports support for this argument list to GDB's qSupported query.
2474 The defined arguments are "start" and "prev", used to reduce work
2475 necessary for library list updating, resulting in significant
2478 * New features in the GDB remote stub, GDBserver
2480 ** GDBserver now supports target-assisted range stepping. Currently
2481 enabled on x86/x86_64 GNU/Linux targets.
2483 ** GDBserver now adds element 'tvar' in the XML in the reply to
2484 'qXfer:traceframe-info:read'. It has the id of the collected
2485 trace state variables.
2487 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2490 * New 'z' formatter for printing and examining memory, this displays the
2491 value as hexadecimal zero padded on the left to the size of the type.
2493 * GDB can now use Windows x64 unwinding data.
2495 * The "set remotebaud" command has been replaced by "set serial baud".
2496 Similarly, "show remotebaud" has been replaced by "show serial baud".
2497 The "set remotebaud" and "show remotebaud" commands are still available
2498 to provide backward compatibility with older versions of GDB.
2500 *** Changes in GDB 7.6
2502 * Target record has been renamed to record-full.
2503 Record/replay is now enabled with the "record full" command.
2504 This also affects settings that are associated with full record/replay
2505 that have been moved from "set/show record" to "set/show record full":
2507 set|show record full insn-number-max
2508 set|show record full stop-at-limit
2509 set|show record full memory-query
2511 * A new record target "record-btrace" has been added. The new target
2512 uses hardware support to record the control-flow of a process. It
2513 does not support replaying the execution, but it implements the
2514 below new commands for investigating the recorded execution log.
2515 This new recording method can be enabled using:
2519 The "record-btrace" target is only available on Intel Atom processors
2520 and requires a Linux kernel 2.6.32 or later.
2522 * Two new commands have been added for record/replay to give information
2523 about the recorded execution without having to replay the execution.
2524 The commands are only supported by "record btrace".
2526 record instruction-history prints the execution history at
2527 instruction granularity
2529 record function-call-history prints the execution history at
2530 function granularity
2532 * New native configurations
2534 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2535 FreeBSD/powerpc powerpc*-*-freebsd
2536 x86_64/Cygwin x86_64-*-cygwin*
2537 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2541 ARM AArch64 aarch64*-*-elf
2542 ARM AArch64 GNU/Linux aarch64*-*-linux
2543 Lynx 178 PowerPC powerpc-*-lynx*178
2544 x86_64/Cygwin x86_64-*-cygwin*
2545 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2547 * If the configured location of system.gdbinit file (as given by the
2548 --with-system-gdbinit option at configure time) is in the
2549 data-directory (as specified by --with-gdb-datadir at configure
2550 time) or in one of its subdirectories, then GDB will look for the
2551 system-wide init file in the directory specified by the
2552 --data-directory command-line option.
2554 * New command line options:
2556 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2557 other initialization files, unlike -nx which disables all of them.
2559 * Removed command line options
2561 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2564 * The 'ptype' and 'whatis' commands now accept an argument to control
2567 * 'info proc' now works on some core files.
2571 ** Vectors can be created with gdb.Type.vector.
2573 ** Python's atexit.register now works in GDB.
2575 ** Types can be pretty-printed via a Python API.
2577 ** Python 3 is now supported (in addition to Python 2.4 or later)
2579 ** New class gdb.Architecture exposes GDB's internal representation
2580 of architecture in the Python API.
2582 ** New method Frame.architecture returns the gdb.Architecture object
2583 corresponding to the frame's architecture.
2585 * New Python-based convenience functions:
2587 ** $_memeq(buf1, buf2, length)
2588 ** $_streq(str1, str2)
2590 ** $_regex(str, regex)
2592 * The 'cd' command now defaults to using '~' (the home directory) if not
2595 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2596 default for GCC since November 2000.
2598 * The command 'forward-search' can now be abbreviated as 'fo'.
2600 * The command 'info tracepoints' can now display 'installed on target'
2601 or 'not installed on target' for each non-pending location of tracepoint.
2603 * New configure options
2605 --enable-libmcheck/--disable-libmcheck
2606 By default, development versions are built with -lmcheck on hosts
2607 that support it, in order to help track memory corruption issues.
2608 Release versions, on the other hand, are built without -lmcheck
2609 by default. The --enable-libmcheck/--disable-libmcheck configure
2610 options allow the user to override that default.
2611 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2612 This configure option allows the user to build GDB with
2613 libbabeltrace using which GDB can read Common Trace Format data.
2615 * New commands (for set/show, see "New options" below)
2618 Catch signals. This is similar to "handle", but allows commands and
2619 conditions to be attached.
2622 List the BFDs known to GDB.
2624 python-interactive [command]
2626 Start a Python interactive prompt, or evaluate the optional command
2627 and print the result of expressions.
2630 "py" is a new alias for "python".
2632 enable type-printer [name]...
2633 disable type-printer [name]...
2634 Enable or disable type printers.
2638 ** For the Renesas Super-H architecture, the "regs" command has been removed
2639 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2644 set print type methods (on|off)
2645 show print type methods
2646 Control whether method declarations are displayed by "ptype".
2647 The default is to show them.
2649 set print type typedefs (on|off)
2650 show print type typedefs
2651 Control whether typedef definitions are displayed by "ptype".
2652 The default is to show them.
2654 set filename-display basename|relative|absolute
2655 show filename-display
2656 Control the way in which filenames is displayed.
2657 The default is "relative", which preserves previous behavior.
2659 set trace-buffer-size
2660 show trace-buffer-size
2661 Request target to change the size of trace buffer.
2663 set remote trace-buffer-size-packet auto|on|off
2664 show remote trace-buffer-size-packet
2665 Control the use of the remote protocol `QTBuffer:size' packet.
2669 Control display of debugging messages related to ARM AArch64.
2672 set debug coff-pe-read
2673 show debug coff-pe-read
2674 Control display of debugging messages related to reading of COFF/PE
2679 Control display of debugging messages related to Mach-O symbols
2682 set debug notification
2683 show debug notification
2684 Control display of debugging info for async remote notification.
2688 ** Command parameter changes are now notified using new async record
2689 "=cmd-param-changed".
2690 ** Trace frame changes caused by command "tfind" are now notified using
2691 new async record "=traceframe-changed".
2692 ** The creation, deletion and modification of trace state variables
2693 are now notified using new async records "=tsv-created",
2694 "=tsv-deleted" and "=tsv-modified".
2695 ** The start and stop of process record are now notified using new
2696 async record "=record-started" and "=record-stopped".
2697 ** Memory changes are now notified using new async record
2699 ** The data-disassemble command response will include a "fullname" field
2700 containing the absolute file name when source has been requested.
2701 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2702 command, to allow pattern filling of memory areas.
2703 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2704 library load/unload events.
2705 ** The response to breakpoint commands and breakpoint async records
2706 includes an "installed" field containing a boolean state about each
2707 non-pending tracepoint location is whether installed on target or not.
2708 ** Output of the "-trace-status" command includes a "trace-file" field
2709 containing the name of the trace file being examined. This field is
2710 optional, and only present when examining a trace file.
2711 ** The "fullname" field is now always present along with the "file" field,
2712 even if the file cannot be found by GDB.
2714 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2715 You must have the LZMA library available when configuring GDB for this
2716 feature to be enabled. For more information, see:
2717 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2719 * New remote packets
2722 Set the size of trace buffer. The remote stub reports support for this
2723 packet to gdb's qSupported query.
2726 Enable Branch Trace Store (BTS)-based branch tracing for the current
2727 thread. The remote stub reports support for this packet to gdb's
2731 Disable branch tracing for the current thread. The remote stub reports
2732 support for this packet to gdb's qSupported query.
2735 Read the traced branches for the current thread. The remote stub
2736 reports support for this packet to gdb's qSupported query.
2738 *** Changes in GDB 7.5
2740 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2741 for more x32 ABI info.
2743 * GDB now supports access to MIPS DSP registers on Linux targets.
2745 * GDB now supports debugging microMIPS binaries.
2747 * The "info os" command on GNU/Linux can now display information on
2748 several new classes of objects managed by the operating system:
2749 "info os procgroups" lists process groups
2750 "info os files" lists file descriptors
2751 "info os sockets" lists internet-domain sockets
2752 "info os shm" lists shared-memory regions
2753 "info os semaphores" lists semaphores
2754 "info os msg" lists message queues
2755 "info os modules" lists loaded kernel modules
2757 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2758 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2759 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2760 options and inspect the probe arguments using the new $_probe_arg family
2761 of convenience variables. You can obtain more information about SystemTap
2762 in <http://sourceware.org/systemtap/>.
2764 * GDB now supports reversible debugging on ARM, it allows you to
2765 debug basic ARM and THUMB instructions, and provides
2766 record/replay support.
2768 * The option "symbol-reloading" has been deleted as it is no longer used.
2772 ** GDB commands implemented in Python can now be put in command class
2775 ** The "maint set python print-stack on|off" is now deleted.
2777 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2778 apply "flag enum"-style pretty-printing to any enum.
2780 ** gdb.lookup_symbol can now work when there is no current frame.
2782 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2783 the source at which the symbol was defined.
2785 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2786 method 'value'. The former indicates whether the symbol needs a
2787 frame in order to compute its value, and the latter computes the
2790 ** A new method 'referenced_value' on gdb.Value objects which can
2791 dereference pointer as well as C++ reference values.
2793 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2794 which return the global and static blocks (as gdb.Block objects),
2795 of the underlying symbol table, respectively.
2797 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2798 object associated with a PC value.
2800 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2801 of the address range occupied by code for the current source line.
2803 * Go language support.
2804 GDB now supports debugging programs written in the Go programming
2807 * GDBserver now supports stdio connections.
2808 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2810 * The binary "gdbtui" can no longer be built or installed.
2811 Use "gdb -tui" instead.
2813 * GDB will now print "flag" enums specially. A flag enum is one where
2814 all the enumerator values have no bits in common when pairwise
2815 "and"ed. When printing a value whose type is a flag enum, GDB will
2816 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2817 (gdb) print (enum E) 3
2820 * The filename part of a linespec will now match trailing components
2821 of a source file name. For example, "break gcc/expr.c:1000" will
2822 now set a breakpoint in build/gcc/expr.c, but not
2823 build/libcpp/expr.c.
2825 * The "info proc" and "generate-core-file" commands will now also
2826 work on remote targets connected to GDBserver on Linux.
2828 * The command "info catch" has been removed. It has been disabled
2829 since December 2007.
2831 * The "catch exception" and "catch assert" commands now accept
2832 a condition at the end of the command, much like the "break"
2833 command does. For instance:
2835 (gdb) catch exception Constraint_Error if Barrier = True
2837 Previously, it was possible to add a condition to such catchpoints,
2838 but it had to be done as a second step, after the catchpoint had been
2839 created, using the "condition" command.
2841 * The "info static-tracepoint-marker" command will now also work on
2842 native Linux targets with in-process agent.
2844 * GDB can now set breakpoints on inlined functions.
2846 * The .gdb_index section has been updated to include symbols for
2847 inlined functions. GDB will ignore older .gdb_index sections by
2848 default, which could cause symbol files to be loaded more slowly
2849 until their .gdb_index sections can be recreated. The new command
2850 "set use-deprecated-index-sections on" will cause GDB to use any older
2851 .gdb_index sections it finds. This will restore performance, but the
2852 ability to set breakpoints on inlined functions will be lost in symbol
2853 files with older .gdb_index sections.
2855 The .gdb_index section has also been updated to record more information
2856 about each symbol. This speeds up the "info variables", "info functions"
2857 and "info types" commands when used with programs having the .gdb_index
2858 section, as well as speeding up debugging with shared libraries using
2859 the .gdb_index section.
2861 * Ada support for GDB/MI Variable Objects has been added.
2863 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2868 ** New command -info-os is the MI equivalent of "info os".
2870 ** Output logs ("set logging" and related) now include MI output.
2874 ** "set use-deprecated-index-sections on|off"
2875 "show use-deprecated-index-sections on|off"
2876 Controls the use of deprecated .gdb_index sections.
2878 ** "catch load" and "catch unload" can be used to stop when a shared
2879 library is loaded or unloaded, respectively.
2881 ** "enable count" can be used to auto-disable a breakpoint after
2884 ** "info vtbl" can be used to show the virtual method tables for
2885 C++ and Java objects.
2887 ** "explore" and its sub commands "explore value" and "explore type"
2888 can be used to recursively explore values and types of
2889 expressions. These commands are available only if GDB is
2890 configured with '--with-python'.
2892 ** "info auto-load" shows status of all kinds of auto-loaded files,
2893 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2894 sequences of commands files, "info auto-load python-scripts"
2895 shows status of auto-loading Python script files,
2896 "info auto-load local-gdbinit" shows status of loading init file
2897 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2898 status of inferior specific thread debugging shared library loading.
2900 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2901 and "show auto-load-scripts" commands have been deprecated, use their
2902 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2903 and "show auto-load python-scripts" counterparts instead.
2905 ** "dprintf location,format,args..." creates a dynamic printf, which
2906 is basically a breakpoint that does a printf and immediately
2907 resumes your program's execution, so it is like a printf that you
2908 can insert dynamically at runtime instead of at compiletime.
2910 ** "set print symbol"
2912 Controls whether GDB attempts to display the symbol, if any,
2913 corresponding to addresses it prints. This defaults to "on", but
2914 you can set it to "off" to restore GDB's previous behavior.
2916 * Deprecated commands
2918 ** For the Renesas Super-H architecture, the "regs" command has been
2919 deprecated, and "info all-registers" should be used instead.
2923 Renesas RL78 rl78-*-elf
2924 HP OpenVMS ia64 ia64-hp-openvms*
2926 * GDBserver supports evaluation of breakpoint conditions. When
2927 support is advertised by GDBserver, GDB may be told to send the
2928 breakpoint conditions in bytecode form to GDBserver. GDBserver
2929 will only report the breakpoint trigger to GDB when its condition
2934 set mips compression
2935 show mips compression
2936 Select the compressed ISA encoding used in functions that have no symbol
2937 information available. The encoding can be set to either of:
2940 and is updated automatically from ELF file flags if available.
2942 set breakpoint condition-evaluation
2943 show breakpoint condition-evaluation
2944 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2945 GDBserver ("target"). Default option "auto" chooses the most efficient
2947 This option can improve debugger efficiency depending on the speed of the
2951 Disable auto-loading globally.
2954 Show auto-loading setting of all kinds of auto-loaded files.
2956 set auto-load gdb-scripts on|off
2957 show auto-load gdb-scripts
2958 Control auto-loading of GDB canned sequences of commands files.
2960 set auto-load python-scripts on|off
2961 show auto-load python-scripts
2962 Control auto-loading of Python script files.
2964 set auto-load local-gdbinit on|off
2965 show auto-load local-gdbinit
2966 Control loading of init file (.gdbinit) from current directory.
2968 set auto-load libthread-db on|off
2969 show auto-load libthread-db
2970 Control auto-loading of inferior specific thread debugging shared library.
2972 set auto-load scripts-directory <dir1>[:<dir2>...]
2973 show auto-load scripts-directory
2974 Set a list of directories from which to load auto-loaded scripts.
2975 Automatically loaded Python scripts and GDB scripts are located in one
2976 of the directories listed by this option.
2977 The delimiter (':' above) may differ according to the host platform.
2979 set auto-load safe-path <dir1>[:<dir2>...]
2980 show auto-load safe-path
2981 Set a list of directories from which it is safe to auto-load files.
2982 The delimiter (':' above) may differ according to the host platform.
2984 set debug auto-load on|off
2985 show debug auto-load
2986 Control display of debugging info for auto-loading the files above.
2988 set dprintf-style gdb|call|agent
2990 Control the way in which a dynamic printf is performed; "gdb"
2991 requests a GDB printf command, while "call" causes dprintf to call a
2992 function in the inferior. "agent" requests that the target agent
2993 (such as GDBserver) do the printing.
2995 set dprintf-function <expr>
2996 show dprintf-function
2997 set dprintf-channel <expr>
2998 show dprintf-channel
2999 Set the function and optional first argument to the call when using
3000 the "call" style of dynamic printf.
3002 set disconnected-dprintf on|off
3003 show disconnected-dprintf
3004 Control whether agent-style dynamic printfs continue to be in effect
3005 after GDB disconnects.
3007 * New configure options
3009 --with-auto-load-dir
3010 Configure default value for the 'set auto-load scripts-directory'
3011 setting above. It defaults to '$debugdir:$datadir/auto-load',
3012 $debugdir representing global debugging info directories (available
3013 via 'show debug-file-directory') and $datadir representing GDB's data
3014 directory (available via 'show data-directory').
3016 --with-auto-load-safe-path
3017 Configure default value for the 'set auto-load safe-path' setting
3018 above. It defaults to the --with-auto-load-dir setting.
3020 --without-auto-load-safe-path
3021 Set 'set auto-load safe-path' to '/', effectively disabling this
3024 * New remote packets
3026 z0/z1 conditional breakpoints extension
3028 The z0/z1 breakpoint insertion packets have been extended to carry
3029 a list of conditional expressions over to the remote stub depending on the
3030 condition evaluation mode. The use of this extension can be controlled
3031 via the "set remote conditional-breakpoints-packet" command.
3035 Specify the signals which the remote stub may pass to the debugged
3036 program without GDB involvement.
3038 * New command line options
3040 --init-command=FILE, -ix Like --command, -x but execute it
3041 before loading inferior.
3042 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3043 execute it before loading inferior.
3045 *** Changes in GDB 7.4
3047 * GDB now handles ambiguous linespecs more consistently; the existing
3048 FILE:LINE support has been expanded to other types of linespecs. A
3049 breakpoint will now be set on all matching locations in all
3050 inferiors, and locations will be added or removed according to
3053 * GDB now allows you to skip uninteresting functions and files when
3054 stepping with the "skip function" and "skip file" commands.
3056 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3057 and "show remote hardware-watchpoint-length-limit". These allows to
3058 set or show the maximum length limit (in bytes) of a remote
3059 target hardware watchpoint.
3061 This allows e.g. to use "unlimited" hardware watchpoints with the
3062 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3063 watchpoints are slower than real hardware watchpoints but are
3064 significantly faster than gdb software watchpoints.
3068 ** The register_pretty_printer function in module gdb.printing now takes
3069 an optional `replace' argument. If True, the new printer replaces any
3072 ** The "maint set python print-stack on|off" command has been
3073 deprecated and will be deleted in GDB 7.5.
3074 A new command: "set python print-stack none|full|message" has
3075 replaced it. Additionally, the default for "print-stack" is
3076 now "message", which just prints the error message without
3079 ** A prompt substitution hook (prompt_hook) is now available to the
3082 ** A new Python module, gdb.prompt has been added to the GDB Python
3083 modules library. This module provides functionality for
3084 escape sequences in prompts (used by set/show
3085 extended-prompt). These escape sequences are replaced by their
3086 corresponding value.
3088 ** Python commands and convenience-functions located in
3089 'data-directory'/python/gdb/command and
3090 'data-directory'/python/gdb/function are now automatically loaded
3093 ** Blocks now provide four new attributes. global_block and
3094 static_block will return the global and static blocks
3095 respectively. is_static and is_global are boolean attributes
3096 that indicate if the block is one of those two types.
3098 ** Symbols now provide the "type" attribute, the type of the symbol.
3100 ** The "gdb.breakpoint" function has been deprecated in favor of
3103 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3104 of a function. This class is based on the "finish" command
3105 available in the CLI.
3107 ** Type objects for struct and union types now allow access to
3108 the fields using standard Python dictionary (mapping) methods.
3109 For example, "some_type['myfield']" now works, as does
3110 "some_type.items()".
3112 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3115 ** A new function, "deep_items" has been added to the gdb.types
3116 module in the GDB Python modules library. This function returns
3117 an iterator over the fields of a struct or union type. Unlike
3118 the standard Python "iteritems" method, it will recursively traverse
3119 any anonymous fields.
3123 ** "*stopped" events can report several new "reason"s, such as
3126 ** Breakpoint changes are now notified using new async records, like
3127 "=breakpoint-modified".
3129 ** New command -ada-task-info.
3131 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3132 $sdir specifies the default system locations of shared libraries.
3133 $pdir specifies the directory where the libpthread used by the application
3136 GDB no longer looks in $sdir and $pdir after it has searched the directories
3137 mentioned in libthread-db-search-path. If you want to search those
3138 directories, they must be specified in libthread-db-search-path.
3139 The default value of libthread-db-search-path on GNU/Linux and Solaris
3140 systems is now "$sdir:$pdir".
3142 $pdir is not supported by gdbserver, it is currently ignored.
3143 $sdir is supported by gdbserver.
3145 * New configure option --with-iconv-bin.
3146 When using the internationalization support like the one in the GNU C
3147 library, GDB will invoke the "iconv" program to get a list of supported
3148 character sets. If this program lives in a non-standard location, one can
3149 use this option to specify where to find it.
3151 * When natively debugging programs on PowerPC BookE processors running
3152 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3153 watchpoints, which specify a mask in addition to an address to watch.
3154 The mask specifies that some bits of an address (the bits which are
3155 reset in the mask) should be ignored when matching the address accessed
3156 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3157 section in the user manual for more details.
3159 * The new option --once causes GDBserver to stop listening for connections once
3160 the first connection is made. The listening port used by GDBserver will
3161 become available after that.
3163 * New commands "info macros" and "alias" have been added.
3165 * New function parameters suffix @entry specifies value of function parameter
3166 at the time the function got called. Entry values are available only since
3172 "!" is now an alias of the "shell" command.
3173 Note that no space is needed between "!" and SHELL COMMAND.
3177 watch EXPRESSION mask MASK_VALUE
3178 The watch command now supports the mask argument which allows creation
3179 of masked watchpoints, if the current architecture supports this feature.
3181 info auto-load-scripts [REGEXP]
3182 This command was formerly named "maintenance print section-scripts".
3183 It is now generally useful and is no longer a maintenance-only command.
3185 info macro [-all] [--] MACRO
3186 The info macro command has new options `-all' and `--'. The first for
3187 printing all definitions of a macro. The second for explicitly specifying
3188 the end of arguments and the beginning of the macro name in case the macro
3189 name starts with a hyphen.
3191 collect[/s] EXPRESSIONS
3192 The tracepoint collect command now takes an optional modifier "/s"
3193 that directs it to dereference pointer-to-character types and
3194 collect the bytes of memory up to a zero byte. The behavior is
3195 similar to what you see when you use the regular print command on a
3196 string. An optional integer following the "/s" sets a bound on the
3197 number of bytes that will be collected.
3200 The trace start command now interprets any supplied arguments as a
3201 note to be recorded with the trace run, with an effect similar to
3202 setting the variable trace-notes.
3205 The trace stop command now interprets any arguments as a note to be
3206 mentioned along with the tstatus report that the trace was stopped
3207 with a command. The effect is similar to setting the variable
3210 * Tracepoints can now be enabled and disabled at any time after a trace
3211 experiment has been started using the standard "enable" and "disable"
3212 commands. It is now possible to start a trace experiment with no enabled
3213 tracepoints; GDB will display a warning, but will allow the experiment to
3214 begin, assuming that tracepoints will be enabled as needed while the trace
3217 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3218 locations with 4-byte instructions, when they were previously
3219 limited to locations with instructions of 5 bytes or longer.
3223 set debug dwarf2-read
3224 show debug dwarf2-read
3225 Turns on or off display of debugging messages related to reading
3226 DWARF debug info. The default is off.
3228 set debug symtab-create
3229 show debug symtab-create
3230 Turns on or off display of debugging messages related to symbol table
3231 creation. The default is off.
3234 show extended-prompt
3235 Set the GDB prompt, and allow escape sequences to be inserted to
3236 display miscellaneous information (see 'help set extended-prompt'
3237 for the list of sequences). This prompt (and any information
3238 accessed through the escape sequences) is updated every time the
3239 prompt is displayed.
3241 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3242 show print entry-values
3243 Set printing of frame argument values at function entry. In some cases
3244 GDB can determine the value of function argument which was passed by the
3245 function caller, even if the value was modified inside the called function.
3247 set debug entry-values
3248 show debug entry-values
3249 Control display of debugging info for determining frame argument values at
3250 function entry and virtual tail call frames.
3252 set basenames-may-differ
3253 show basenames-may-differ
3254 Set whether a source file may have multiple base names.
3255 (A "base name" is the name of a file with the directory part removed.
3256 Example: The base name of "/home/user/hello.c" is "hello.c".)
3257 If set, GDB will canonicalize file names (e.g., expand symlinks)
3258 before comparing them. Canonicalization is an expensive operation,
3259 but it allows the same file be known by more than one base name.
3260 If not set (the default), all source files are assumed to have just
3261 one base name, and gdb will do file name comparisons more efficiently.
3267 Set a user name and notes for the current and any future trace runs.
3268 This is useful for long-running and/or disconnected traces, to
3269 inform others (or yourself) as to who is running the trace, supply
3270 contact information, or otherwise explain what is going on.
3272 set trace-stop-notes
3273 show trace-stop-notes
3274 Set a note attached to the trace run, that is displayed when the
3275 trace has been stopped by a tstop command. This is useful for
3276 instance as an explanation, if you are stopping a trace run that was
3277 started by someone else.
3279 * New remote packets
3283 Dynamically enable a tracepoint in a started trace experiment.
3287 Dynamically disable a tracepoint in a started trace experiment.
3291 Set the user and notes of the trace run.
3295 Query the current status of a tracepoint.
3299 Query the minimum length of instruction at which a fast tracepoint may
3302 * Dcache size (number of lines) and line-size are now runtime-configurable
3303 via "set dcache line" and "set dcache line-size" commands.
3307 Texas Instruments TMS320C6x tic6x-*-*
3311 Renesas RL78 rl78-*-elf
3313 *** Changes in GDB 7.3.1
3315 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3317 *** Changes in GDB 7.3
3319 * GDB has a new command: "thread find [REGEXP]".
3320 It finds the thread id whose name, target id, or thread extra info
3321 matches the given regular expression.
3323 * The "catch syscall" command now works on mips*-linux* targets.
3325 * The -data-disassemble MI command now supports modes 2 and 3 for
3326 dumping the instruction opcodes.
3328 * New command line options
3330 -data-directory DIR Specify DIR as the "data-directory".
3331 This is mostly for testing purposes.
3333 * The "maint set python auto-load on|off" command has been renamed to
3334 "set auto-load-scripts on|off".
3336 * GDB has a new command: "set directories".
3337 It is like the "dir" command except that it replaces the
3338 source path list instead of augmenting it.
3340 * GDB now understands thread names.
3342 On GNU/Linux, "info threads" will display the thread name as set by
3343 prctl or pthread_setname_np.
3345 There is also a new command, "thread name", which can be used to
3346 assign a name internally for GDB to display.
3349 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3350 has been integrated into GDB.
3354 ** The function gdb.Write now accepts an optional keyword 'stream'.
3355 This keyword, when provided, will direct the output to either
3356 stdout, stderr, or GDB's logging output.
3358 ** Parameters can now be be sub-classed in Python, and in particular
3359 you may implement the get_set_doc and get_show_doc functions.
3360 This improves how Parameter set/show documentation is processed
3361 and allows for more dynamic content.
3363 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3364 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3365 have an is_valid method.
3367 ** Breakpoints can now be sub-classed in Python, and in particular
3368 you may implement a 'stop' function that is executed each time
3369 the inferior reaches that breakpoint.
3371 ** New function gdb.lookup_global_symbol looks up a global symbol.
3373 ** GDB values in Python are now callable if the value represents a
3374 function. For example, if 'some_value' represents a function that
3375 takes two integer parameters and returns a value, you can call
3376 that function like so:
3378 result = some_value (10,20)
3380 ** Module gdb.types has been added.
3381 It contains a collection of utilities for working with gdb.Types objects:
3382 get_basic_type, has_field, make_enum_dict.
3384 ** Module gdb.printing has been added.
3385 It contains utilities for writing and registering pretty-printers.
3386 New classes: PrettyPrinter, SubPrettyPrinter,
3387 RegexpCollectionPrettyPrinter.
3388 New function: register_pretty_printer.
3390 ** New commands "info pretty-printers", "enable pretty-printer" and
3391 "disable pretty-printer" have been added.
3393 ** gdb.parameter("directories") is now available.
3395 ** New function gdb.newest_frame returns the newest frame in the
3398 ** The gdb.InferiorThread class has a new "name" attribute. This
3399 holds the thread's name.
3401 ** Python Support for Inferior events.
3402 Python scripts can add observers to be notified of events
3403 occurring in the process being debugged.
3404 The following events are currently supported:
3405 - gdb.events.cont Continue event.
3406 - gdb.events.exited Inferior exited event.
3407 - gdb.events.stop Signal received, and Breakpoint hit events.
3411 ** GDB now puts template parameters in scope when debugging in an
3412 instantiation. For example, if you have:
3414 template<int X> int func (void) { return X; }
3416 then if you step into func<5>, "print X" will show "5". This
3417 feature requires proper debuginfo support from the compiler; it
3418 was added to GCC 4.5.
3420 ** The motion commands "next", "finish", "until", and "advance" now
3421 work better when exceptions are thrown. In particular, GDB will
3422 no longer lose control of the inferior; instead, the GDB will
3423 stop the inferior at the point at which the exception is caught.
3424 This functionality requires a change in the exception handling
3425 code that was introduced in GCC 4.5.
3427 * GDB now follows GCC's rules on accessing volatile objects when
3428 reading or writing target state during expression evaluation.
3429 One notable difference to prior behavior is that "print x = 0"
3430 no longer generates a read of x; the value of the assignment is
3431 now always taken directly from the value being assigned.
3433 * GDB now has some support for using labels in the program's source in
3434 linespecs. For instance, you can use "advance label" to continue
3435 execution to a label.
3437 * GDB now has support for reading and writing a new .gdb_index
3438 section. This section holds a fast index of DWARF debugging
3439 information and can be used to greatly speed up GDB startup and
3440 operation. See the documentation for `save gdb-index' for details.
3442 * The "watch" command now accepts an optional "-location" argument.
3443 When used, this causes GDB to watch the memory referred to by the
3444 expression. Such a watchpoint is never deleted due to it going out
3447 * GDB now supports thread debugging of core dumps on GNU/Linux.
3449 GDB now activates thread debugging using the libthread_db library
3450 when debugging GNU/Linux core dumps, similarly to when debugging
3451 live processes. As a result, when debugging a core dump file, GDB
3452 is now able to display pthread_t ids of threads. For example, "info
3453 threads" shows the same output as when debugging the process when it
3454 was live. In earlier releases, you'd see something like this:
3457 * 1 LWP 6780 main () at main.c:10
3459 While now you see this:
3462 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3464 It is also now possible to inspect TLS variables when debugging core
3467 When debugging a core dump generated on a machine other than the one
3468 used to run GDB, you may need to point GDB at the correct
3469 libthread_db library with the "set libthread-db-search-path"
3470 command. See the user manual for more details on this command.
3472 * When natively debugging programs on PowerPC BookE processors running
3473 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3474 which stop execution of the inferior whenever it executes an instruction
3475 at any address within the specified range. See the "PowerPC Embedded"
3476 section in the user manual for more details.
3478 * New features in the GDB remote stub, GDBserver
3480 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3481 and i686 LynxOS (version 5.x).
3483 ** GDBserver is now supported on Blackfin Linux.
3485 * New native configurations
3487 ia64 HP-UX ia64-*-hpux*
3491 Analog Devices, Inc. Blackfin Processor bfin-*
3493 * Ada task switching is now supported on sparc-elf targets when
3494 debugging a program using the Ravenscar Profile. For more information,
3495 see the "Tasking Support when using the Ravenscar Profile" section
3496 in the GDB user manual.
3498 * Guile support was removed.
3500 * New features in the GNU simulator
3502 ** The --map-info flag lists all known core mappings.
3504 ** CFI flashes may be simulated via the "cfi" device.
3506 *** Changes in GDB 7.2
3508 * Shared library support for remote targets by default
3510 When GDB is configured for a generic, non-OS specific target, like
3511 for example, --target=arm-eabi or one of the many *-*-elf targets,
3512 GDB now queries remote stubs for loaded shared libraries using the
3513 `qXfer:libraries:read' packet. Previously, shared library support
3514 was always disabled for such configurations.
3518 ** Argument Dependent Lookup (ADL)
3520 In C++ ADL lookup directs function search to the namespaces of its
3521 arguments even if the namespace has not been imported.
3531 Here the compiler will search for `foo' in the namespace of 'b'
3532 and find A::foo. GDB now supports this. This construct is commonly
3533 used in the Standard Template Library for operators.
3535 ** Improved User Defined Operator Support
3537 In addition to member operators, GDB now supports lookup of operators
3538 defined in a namespace and imported with a `using' directive, operators
3539 defined in the global scope, operators imported implicitly from an
3540 anonymous namespace, and the ADL operators mentioned in the previous
3542 GDB now also supports proper overload resolution for all the previously
3543 mentioned flavors of operators.
3545 ** static const class members
3547 Printing of static const class members that are initialized in the
3548 class definition has been fixed.
3550 * Windows Thread Information Block access.
3552 On Windows targets, GDB now supports displaying the Windows Thread
3553 Information Block (TIB) structure. This structure is visible either
3554 by using the new command `info w32 thread-information-block' or, by
3555 dereferencing the new convenience variable named `$_tlb', a
3556 thread-specific pointer to the TIB. This feature is also supported
3557 when remote debugging using GDBserver.
3559 * Static tracepoints
3561 Static tracepoints are calls in the user program into a tracing
3562 library. One such library is a port of the LTTng kernel tracer to
3563 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3564 When debugging with GDBserver, GDB now supports combining the GDB
3565 tracepoint machinery with such libraries. For example: the user can
3566 use GDB to probe a static tracepoint marker (a call from the user
3567 program into the tracing library) with the new "strace" command (see
3568 "New commands" below). This creates a "static tracepoint" in the
3569 breakpoint list, that can be manipulated with the same feature set
3570 as fast and regular tracepoints. E.g., collect registers, local and
3571 global variables, collect trace state variables, and define
3572 tracepoint conditions. In addition, the user can collect extra
3573 static tracepoint marker specific data, by collecting the new
3574 $_sdata internal variable. When analyzing the trace buffer, you can
3575 inspect $_sdata like any other variable available to GDB. For more
3576 information, see the "Tracepoints" chapter in GDB user manual. New
3577 remote packets have been defined to support static tracepoints, see
3578 the "New remote packets" section below.
3580 * Better reconstruction of tracepoints after disconnected tracing
3582 GDB will attempt to download the original source form of tracepoint
3583 definitions when starting a trace run, and then will upload these
3584 upon reconnection to the target, resulting in a more accurate
3585 reconstruction of the tracepoints that are in use on the target.
3589 You can now exercise direct control over the ways that GDB can
3590 affect your program. For instance, you can disallow the setting of
3591 breakpoints, so that the program can run continuously (assuming
3592 non-stop mode). In addition, the "observer" variable is available
3593 to switch all of the different controls; in observer mode, GDB
3594 cannot affect the target's behavior at all, which is useful for
3595 tasks like diagnosing live systems in the field.
3597 * The new convenience variable $_thread holds the number of the
3600 * New remote packets
3604 Return the address of the Windows Thread Information Block of a given thread.
3608 In response to several of the tracepoint packets, the target may now
3609 also respond with a number of intermediate `qRelocInsn' request
3610 packets before the final result packet, to have GDB handle
3611 relocating an instruction to execute at a different address. This
3612 is particularly useful for stubs that support fast tracepoints. GDB
3613 reports support for this feature in the qSupported packet.
3617 List static tracepoint markers in the target program.
3621 List static tracepoint markers at a given address in the target
3624 qXfer:statictrace:read
3626 Read the static trace data collected (by a `collect $_sdata'
3627 tracepoint action). The remote stub reports support for this packet
3628 to gdb's qSupported query.
3632 Send the current settings of GDB's permission flags.
3636 Send part of the source (textual) form of a tracepoint definition,
3637 which includes location, conditional, and action list.
3639 * The source command now accepts a -s option to force searching for the
3640 script in the source search path even if the script name specifies
3643 * New features in the GDB remote stub, GDBserver
3645 - GDBserver now support tracepoints (including fast tracepoints, and
3646 static tracepoints). The feature is currently supported by the
3647 i386-linux and amd64-linux builds. See the "Tracepoints support
3648 in gdbserver" section in the manual for more information.
3650 GDBserver JIT compiles the tracepoint's conditional agent
3651 expression bytecode into native code whenever possible for low
3652 overhead dynamic tracepoints conditionals. For such tracepoints,
3653 an expression that examines program state is evaluated when the
3654 tracepoint is reached, in order to determine whether to capture
3655 trace data. If the condition is simple and false, processing the
3656 tracepoint finishes very quickly and no data is gathered.
3658 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3659 for static tracepoints support.
3661 - GDBserver now supports x86_64 Windows 64-bit debugging.
3663 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3664 it understands register description.
3666 * The --batch flag now disables pagination and queries.
3668 * X86 general purpose registers
3670 GDB now supports reading/writing byte, word and double-word x86
3671 general purpose registers directly. This means you can use, say,
3672 $ah or $ax to refer, respectively, to the byte register AH and
3673 16-bit word register AX that are actually portions of the 32-bit
3674 register EAX or 64-bit register RAX.
3676 * The `commands' command now accepts a range of breakpoints to modify.
3677 A plain `commands' following a command that creates multiple
3678 breakpoints affects all the breakpoints set by that command. This
3679 applies to breakpoints set by `rbreak', and also applies when a
3680 single `break' command creates multiple breakpoints (e.g.,
3681 breakpoints on overloaded c++ functions).
3683 * The `rbreak' command now accepts a filename specification as part of
3684 its argument, limiting the functions selected by the regex to those
3685 in the specified file.
3687 * Support for remote debugging Windows and SymbianOS shared libraries
3688 from Unix hosts has been improved. Non Windows GDB builds now can
3689 understand target reported file names that follow MS-DOS based file
3690 system semantics, such as file names that include drive letters and
3691 use the backslash character as directory separator. This makes it
3692 possible to transparently use the "set sysroot" and "set
3693 solib-search-path" on Unix hosts to point as host copies of the
3694 target's shared libraries. See the new command "set
3695 target-file-system-kind" described below, and the "Commands to
3696 specify files" section in the user manual for more information.
3700 eval template, expressions...
3701 Convert the values of one or more expressions under the control
3702 of the string template to a command line, and call it.
3704 set target-file-system-kind unix|dos-based|auto
3705 show target-file-system-kind
3706 Set or show the assumed file system kind for target reported file
3709 save breakpoints <filename>
3710 Save all current breakpoint definitions to a file suitable for use
3711 in a later debugging session. To read the saved breakpoint
3712 definitions, use the `source' command.
3714 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3717 info static-tracepoint-markers
3718 Display information about static tracepoint markers in the target.
3720 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3721 Define a static tracepoint by probing a marker at the given
3722 function, line, address, or marker ID.
3726 Enable and disable observer mode.
3728 set may-write-registers on|off
3729 set may-write-memory on|off
3730 set may-insert-breakpoints on|off
3731 set may-insert-tracepoints on|off
3732 set may-insert-fast-tracepoints on|off
3733 set may-interrupt on|off
3734 Set individual permissions for GDB effects on the target. Note that
3735 some of these settings can have undesirable or surprising
3736 consequences, particularly when changed in the middle of a session.
3737 For instance, disabling the writing of memory can prevent
3738 breakpoints from being inserted, cause single-stepping to fail, or
3739 even crash your program, if you disable after breakpoints have been
3740 inserted. However, GDB should not crash.
3742 set record memory-query on|off
3743 show record memory-query
3744 Control whether to stop the inferior if memory changes caused
3745 by an instruction cannot be recorded.
3750 The disassemble command now supports "start,+length" form of two arguments.
3754 ** GDB now provides a new directory location, called the python directory,
3755 where Python scripts written for GDB can be installed. The location
3756 of that directory is <data-directory>/python, where <data-directory>
3757 is the GDB data directory. For more details, see section `Scripting
3758 GDB using Python' in the manual.
3760 ** The GDB Python API now has access to breakpoints, symbols, symbol
3761 tables, program spaces, inferiors, threads and frame's code blocks.
3762 Additionally, GDB Parameters can now be created from the API, and
3763 manipulated via set/show in the CLI.
3765 ** New functions gdb.target_charset, gdb.target_wide_charset,
3766 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3768 ** New exception gdb.GdbError.
3770 ** Pretty-printers are now also looked up in the current program space.
3772 ** Pretty-printers can now be individually enabled and disabled.
3774 ** GDB now looks for names of Python scripts to auto-load in a
3775 special section named `.debug_gdb_scripts', in addition to looking
3776 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3778 * Tracepoint actions were unified with breakpoint commands. In particular,
3779 there are no longer differences in "info break" output for breakpoints and
3780 tracepoints and the "commands" command can be used for both tracepoints and
3781 regular breakpoints.
3785 ARM Symbian arm*-*-symbianelf*
3787 * D language support.
3788 GDB now supports debugging programs written in the D programming
3791 * GDB now supports the extended ptrace interface for PowerPC which is
3792 available since Linux kernel version 2.6.34. This automatically enables
3793 any hardware breakpoints and additional hardware watchpoints available in
3794 the processor. The old ptrace interface exposes just one hardware
3795 watchpoint and no hardware breakpoints.
3797 * GDB is now able to use the Data Value Compare (DVC) register available on
3798 embedded PowerPC processors to implement in hardware simple watchpoint
3799 conditions of the form:
3801 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3803 This works in native GDB running on Linux kernels with the extended ptrace
3804 interface mentioned above.
3806 *** Changes in GDB 7.1
3810 ** Namespace Support
3812 GDB now supports importing of namespaces in C++. This enables the
3813 user to inspect variables from imported namespaces. Support for
3814 namepace aliasing has also been added. So, if a namespace is
3815 aliased in the current scope (e.g. namepace C=A; ) the user can
3816 print variables using the alias (e.g. (gdb) print C::x).
3820 All known bugs relating to the printing of virtual base class were
3821 fixed. It is now possible to call overloaded static methods using a
3826 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3827 and reinterpret_cast<> are now handled by the C++ expression parser.
3831 Xilinx MicroBlaze microblaze-*-*
3836 Xilinx MicroBlaze microblaze
3839 * Multi-program debugging.
3841 GDB now has support for multi-program (a.k.a. multi-executable or
3842 multi-exec) debugging. This allows for debugging multiple inferiors
3843 simultaneously each running a different program under the same GDB
3844 session. See "Debugging Multiple Inferiors and Programs" in the
3845 manual for more information. This implied some user visible changes
3846 in the multi-inferior support. For example, "info inferiors" now
3847 lists inferiors that are not running yet or that have exited
3848 already. See also "New commands" and "New options" below.
3850 * New tracing features
3852 GDB's tracepoint facility now includes several new features:
3854 ** Trace state variables
3856 GDB tracepoints now include support for trace state variables, which
3857 are variables managed by the target agent during a tracing
3858 experiment. They are useful for tracepoints that trigger each
3859 other, so for instance one tracepoint can count hits in a variable,
3860 and then a second tracepoint has a condition that is true when the
3861 count reaches a particular value. Trace state variables share the
3862 $-syntax of GDB convenience variables, and can appear in both
3863 tracepoint actions and condition expressions. Use the "tvariable"
3864 command to create, and "info tvariables" to view; see "Trace State
3865 Variables" in the manual for more detail.
3869 GDB now includes an option for defining fast tracepoints, which
3870 targets may implement more efficiently, such as by installing a jump
3871 into the target agent rather than a trap instruction. The resulting
3872 speedup can be by two orders of magnitude or more, although the
3873 tradeoff is that some program locations on some target architectures
3874 might not allow fast tracepoint installation, for instance if the
3875 instruction to be replaced is shorter than the jump. To request a
3876 fast tracepoint, use the "ftrace" command, with syntax identical to
3877 the regular trace command.
3879 ** Disconnected tracing
3881 It is now possible to detach GDB from the target while it is running
3882 a trace experiment, then reconnect later to see how the experiment
3883 is going. In addition, a new variable disconnected-tracing lets you
3884 tell the target agent whether to continue running a trace if the
3885 connection is lost unexpectedly.
3889 GDB now has the ability to save the trace buffer into a file, and
3890 then use that file as a target, similarly to you can do with
3891 corefiles. You can select trace frames, print data that was
3892 collected in them, and use tstatus to display the state of the
3893 tracing run at the moment that it was saved. To create a trace
3894 file, use "tsave <filename>", and to use it, do "target tfile
3897 ** Circular trace buffer
3899 You can ask the target agent to handle the trace buffer as a
3900 circular buffer, discarding the oldest trace frames to make room for
3901 newer ones, by setting circular-trace-buffer to on. This feature may
3902 not be available for all target agents.
3907 The disassemble command, when invoked with two arguments, now requires
3908 the arguments to be comma-separated.
3911 The info variables command now displays variable definitions. Files
3912 which only declare a variable are not shown.
3915 The source command is now capable of sourcing Python scripts.
3916 This feature is dependent on the debugger being build with Python
3919 Related to this enhancement is also the introduction of a new command
3920 "set script-extension" (see below).
3922 * New commands (for set/show, see "New options" below)
3924 record save [<FILENAME>]
3925 Save a file (in core file format) containing the process record
3926 execution log for replay debugging at a later time.
3928 record restore <FILENAME>
3929 Restore the process record execution log that was saved at an
3930 earlier time, for replay debugging.
3932 add-inferior [-copies <N>] [-exec <FILENAME>]
3935 clone-inferior [-copies <N>] [ID]
3936 Make a new inferior ready to execute the same program another
3937 inferior has loaded.
3942 maint info program-spaces
3943 List the program spaces loaded into GDB.
3945 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3946 show remote interrupt-sequence
3947 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3948 as the sequence to the remote target in order to interrupt the execution.
3949 Ctrl-C is a default. Some system prefers BREAK which is high level of
3950 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3951 Magic SysRq g. It is BREAK signal and character 'g'.
3953 set remote interrupt-on-connect [on | off]
3954 show remote interrupt-on-connect
3955 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3956 remote target when gdb connects to it. This is needed when you debug
3959 set remotebreak [on | off]
3961 Deprecated. Use "set/show remote interrupt-sequence" instead.
3963 tvariable $NAME [ = EXP ]
3964 Create or modify a trace state variable.
3967 List trace state variables and their values.
3969 delete tvariable $NAME ...
3970 Delete one or more trace state variables.
3973 Evaluate the given expressions without collecting anything into the
3974 trace buffer. (Valid in tracepoint actions only.)
3976 ftrace FN / FILE:LINE / *ADDR
3977 Define a fast tracepoint at the given function, line, or address.
3979 * New expression syntax
3981 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3982 GDB now parses 0b101010 identically with 42.
3986 set follow-exec-mode new|same
3987 show follow-exec-mode
3988 Control whether GDB reuses the same inferior across an exec call or
3989 creates a new one. This is useful to be able to restart the old
3990 executable after the inferior having done an exec call.
3992 set default-collect EXPR, ...
3993 show default-collect
3994 Define a list of expressions to be collected at each tracepoint.
3995 This is a useful way to ensure essential items are not overlooked,
3996 such as registers or a critical global variable.
3998 set disconnected-tracing
3999 show disconnected-tracing
4000 If set to 1, the target is instructed to continue tracing if it
4001 loses its connection to GDB. If 0, the target is to stop tracing
4004 set circular-trace-buffer
4005 show circular-trace-buffer
4006 If set to on, the target is instructed to use a circular trace buffer
4007 and discard the oldest trace frames instead of stopping the trace due
4008 to a full trace buffer. If set to off, the trace stops when the buffer
4009 fills up. Some targets may not support this.
4011 set script-extension off|soft|strict
4012 show script-extension
4013 If set to "off", the debugger does not perform any script language
4014 recognition, and all sourced files are assumed to be GDB scripts.
4015 If set to "soft" (the default), files are sourced according to
4016 filename extension, falling back to GDB scripts if the first
4018 If set to "strict", files are sourced according to filename extension.
4020 set ada trust-PAD-over-XVS on|off
4021 show ada trust-PAD-over-XVS
4022 If off, activate a workaround against a bug in the debugging information
4023 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4024 the GCC sources for more information about the GNAT encoding and
4025 PAD types in particular). It is always safe to set this option to
4026 off, but this introduces a slight performance penalty. The default
4029 * Python API Improvements
4031 ** GDB provides the new class gdb.LazyString. This is useful in
4032 some pretty-printing cases. The new method gdb.Value.lazy_string
4033 provides a simple way to create objects of this type.
4035 ** The fields returned by gdb.Type.fields now have an
4036 `is_base_class' attribute.
4038 ** The new method gdb.Type.range returns the range of an array type.
4040 ** The new method gdb.parse_and_eval can be used to parse and
4041 evaluate an expression.
4043 * New remote packets
4046 Define a trace state variable.
4049 Get the current value of a trace state variable.
4052 Set desired tracing behavior upon disconnection.
4055 Set the trace buffer to be linear or circular.
4058 Get data about the tracepoints currently in use.
4062 Process record now works correctly with hardware watchpoints.
4064 Multiple bug fixes have been made to the mips-irix port, making it
4065 much more reliable. In particular:
4066 - Debugging threaded applications is now possible again. Previously,
4067 GDB would hang while starting the program, or while waiting for
4068 the program to stop at a breakpoint.
4069 - Attaching to a running process no longer hangs.
4070 - An error occurring while loading a core file has been fixed.
4071 - Changing the value of the PC register now works again. This fixes
4072 problems observed when using the "jump" command, or when calling
4073 a function from GDB, or even when assigning a new value to $pc.
4074 - With the "finish" and "return" commands, the return value for functions
4075 returning a small array is now correctly printed.
4076 - It is now possible to break on shared library code which gets executed
4077 during a shared library init phase (code executed while executing
4078 their .init section). Previously, the breakpoint would have no effect.
4079 - GDB is now able to backtrace through the signal handler for
4080 non-threaded programs.
4082 PIE (Position Independent Executable) programs debugging is now supported.
4083 This includes debugging execution of PIC (Position Independent Code) shared
4084 libraries although for that, it should be possible to run such libraries as an
4087 *** Changes in GDB 7.0
4089 * GDB now has an interface for JIT compilation. Applications that
4090 dynamically generate code can create symbol files in memory and register
4091 them with GDB. For users, the feature should work transparently, and
4092 for JIT developers, the interface is documented in the GDB manual in the
4093 "JIT Compilation Interface" chapter.
4095 * Tracepoints may now be conditional. The syntax is as for
4096 breakpoints; either an "if" clause appended to the "trace" command,
4097 or the "condition" command is available. GDB sends the condition to
4098 the target for evaluation using the same bytecode format as is used
4099 for tracepoint actions.
4101 * The disassemble command now supports: an optional /r modifier, print the
4102 raw instructions in hex as well as in symbolic form, and an optional /m
4103 modifier to print mixed source+assembly.
4105 * Process record and replay
4107 In a architecture environment that supports ``process record and
4108 replay'', ``process record and replay'' target can record a log of
4109 the process execution, and replay it with both forward and reverse
4112 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4113 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4114 set execution-direction {forward|reverse}, for targets that support
4117 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4118 feature is available with a native GDB running on kernel version
4121 * GDB now has support for multi-byte and wide character sets on the
4122 target. Strings whose character type is wchar_t, char16_t, or
4123 char32_t are now correctly printed. GDB supports wide- and unicode-
4124 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4125 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4126 `printf'. This feature requires iconv to work properly; if your
4127 system does not have a working iconv, GDB can use GNU libiconv. See
4128 the installation instructions for more information.
4130 * GDB now supports automatic retrieval of shared library files from
4131 remote targets. To use this feature, specify a system root that begins
4132 with the `remote:' prefix, either via the `set sysroot' command or via
4133 the `--with-sysroot' configure-time option.
4135 * "info sharedlibrary" now takes an optional regex of libraries to show,
4136 and it now reports if a shared library has no debugging information.
4138 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4139 now complete on file names.
4141 * When completing in expressions, gdb will attempt to limit
4142 completions to allowable structure or union fields, where appropriate.
4143 For instance, consider:
4145 # struct example { int f1; double f2; };
4146 # struct example variable;
4149 If the user types TAB at the end of this command line, the available
4150 completions will be "f1" and "f2".
4152 * Inlined functions are now supported. They show up in backtraces, and
4153 the "step", "next", and "finish" commands handle them automatically.
4155 * GDB now supports the token-splicing (##) and stringification (#)
4156 operators when expanding macros. It also supports variable-arity
4159 * GDB now supports inspecting extra signal information, exported by
4160 the new $_siginfo convenience variable. The feature is currently
4161 implemented on linux ARM, i386 and amd64.
4163 * GDB can now display the VFP floating point registers and NEON vector
4164 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4165 can provide these registers (requires Linux 2.6.30 or later). Remote
4166 and simulator targets may also provide them.
4168 * New remote packets
4171 Search memory for a sequence of bytes.
4174 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4175 operation over reliable transport links. Use of this packet is
4176 controlled by the `set remote noack-packet' command.
4179 Kill the process with the specified process ID. Use this in preference
4180 to `k' when multiprocess protocol extensions are supported.
4183 Obtains additional operating system information
4187 Read or write additional signal information.
4189 * Removed remote protocol undocumented extension
4191 An undocumented extension to the remote protocol's `S' stop reply
4192 packet that permited the stub to pass a process id was removed.
4193 Remote servers should use the `T' stop reply packet instead.
4195 * GDB now supports multiple function calling conventions according to the
4196 DWARF-2 DW_AT_calling_convention function attribute.
4198 * The SH target utilizes the aforementioned change to distinguish between gcc
4199 and Renesas calling convention. It also adds the new CLI commands
4200 `set/show sh calling-convention'.
4202 * GDB can now read compressed debug sections, as produced by GNU gold
4203 with the --compress-debug-sections=zlib flag.
4205 * 64-bit core files are now supported on AIX.
4207 * Thread switching is now supported on Tru64.
4209 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4210 which will be allocated using malloc later in program execution.
4212 * The qXfer:libraries:read remote procotol packet now allows passing a
4213 list of section offsets.
4215 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4216 conditions handling signals delivered during attach or thread creation
4217 have also been fixed.
4219 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4220 From the user's standpoint, all unqualified instances of True and False
4221 are treated as the standard definitions, regardless of context.
4223 * GDB now parses C++ symbol and type names more flexibly. For
4226 template<typename T> class C { };
4229 GDB will now correctly handle all of:
4231 ptype C<char const *>
4232 ptype C<char const*>
4233 ptype C<const char *>
4234 ptype C<const char*>
4236 * New features in the GDB remote stub, gdbserver
4238 - The "--wrapper" command-line argument tells gdbserver to use a
4239 wrapper program to launch programs for debugging.
4241 - On PowerPC and S/390 targets, it is now possible to use a single
4242 gdbserver executable to debug both 32-bit and 64-bit programs.
4243 (This requires gdbserver itself to be built as a 64-bit executable.)
4245 - gdbserver uses the new noack protocol mode for TCP connections to
4246 reduce communications latency, if also supported and enabled in GDB.
4248 - Support for the sparc64-linux-gnu target is now included in
4251 - The amd64-linux build of gdbserver now supports debugging both
4252 32-bit and 64-bit programs.
4254 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4255 now support hardware watchpoints, and will use them automatically
4260 GDB now has support for scripting using Python. Whether this is
4261 available is determined at configure time.
4263 New GDB commands can now be written in Python.
4265 * Ada tasking support
4267 Ada tasks can now be inspected in GDB. The following commands have
4271 Print the list of Ada tasks.
4273 Print detailed information about task number N.
4275 Print the task number of the current task.
4277 Switch the context of debugging to task number N.
4279 * Support for user-defined prefixed commands. The "define" command can
4280 add new commands to existing prefixes, e.g. "target".
4282 * Multi-inferior, multi-process debugging.
4284 GDB now has generalized support for multi-inferior debugging. See
4285 "Debugging Multiple Inferiors" in the manual for more information.
4286 Although availability still depends on target support, the command
4287 set is more uniform now. The GNU/Linux specific multi-forks support
4288 has been migrated to this new framework. This implied some user
4289 visible changes; see "New commands" and also "Removed commands"
4292 * Target descriptions can now describe the target OS ABI. See the
4293 "Target Description Format" section in the user manual for more
4296 * Target descriptions can now describe "compatible" architectures
4297 to indicate that the target can execute applications for a different
4298 architecture in addition to those for the main target architecture.
4299 See the "Target Description Format" section in the user manual for
4302 * Multi-architecture debugging.
4304 GDB now includes general supports for debugging applications on
4305 hybrid systems that use more than one single processor architecture
4306 at the same time. Each such hybrid architecture still requires
4307 specific support to be added. The only hybrid architecture supported
4308 in this version of GDB is the Cell Broadband Engine.
4310 * GDB now supports integrated debugging of Cell/B.E. applications that
4311 use both the PPU and SPU architectures. To enable support for hybrid
4312 Cell/B.E. debugging, you need to configure GDB to support both the
4313 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4314 --enable-targets configure option.
4316 * Non-stop mode debugging.
4318 For some targets, GDB now supports an optional mode of operation in
4319 which you can examine stopped threads while other threads continue
4320 to execute freely. This is referred to as non-stop mode, with the
4321 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4322 section in the user manual for more information.
4324 To be able to support remote non-stop debugging, a remote stub needs
4325 to implement the non-stop mode remote protocol extensions, as
4326 described in the "Remote Non-Stop" section of the user manual. The
4327 GDB remote stub, gdbserver, has been adjusted to support these
4328 extensions on linux targets.
4330 * New commands (for set/show, see "New options" below)
4332 catch syscall [NAME(S) | NUMBER(S)]
4333 Catch system calls. Arguments, which should be names of system
4334 calls or their numbers, mean catch only those syscalls. Without
4335 arguments, every syscall will be caught. When the inferior issues
4336 any of the specified syscalls, GDB will stop and announce the system
4337 call, both when it is called and when its call returns. This
4338 feature is currently available with a native GDB running on the
4339 Linux Kernel, under the following architectures: x86, x86_64,
4340 PowerPC and PowerPC64.
4342 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4344 Search memory for a sequence of bytes.
4346 maint set python print-stack
4347 maint show python print-stack
4348 Show a stack trace when an error is encountered in a Python script.
4351 Invoke CODE by passing it to the Python interpreter.
4356 These allow macros to be defined, undefined, and listed
4360 Show operating system information about processes.
4363 List the inferiors currently under GDB's control.
4366 Switch focus to inferior number NUM.
4369 Detach from inferior number NUM.
4372 Kill inferior number NUM.
4376 set spu stop-on-load
4377 show spu stop-on-load
4378 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4380 set spu auto-flush-cache
4381 show spu auto-flush-cache
4382 Control whether to automatically flush the software-managed cache
4383 during Cell/B.E. debugging.
4385 set sh calling-convention
4386 show sh calling-convention
4387 Control the calling convention used when calling SH target functions.
4390 show debug timestamp
4391 Control display of timestamps with GDB debugging output.
4393 set disassemble-next-line
4394 show disassemble-next-line
4395 Control display of disassembled source lines or instructions when
4398 set remote noack-packet
4399 show remote noack-packet
4400 Set/show the use of remote protocol QStartNoAckMode packet. See above
4401 under "New remote packets."
4403 set remote query-attached-packet
4404 show remote query-attached-packet
4405 Control use of remote protocol `qAttached' (query-attached) packet.
4407 set remote read-siginfo-object
4408 show remote read-siginfo-object
4409 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4412 set remote write-siginfo-object
4413 show remote write-siginfo-object
4414 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4417 set remote reverse-continue
4418 show remote reverse-continue
4419 Control use of remote protocol 'bc' (reverse-continue) packet.
4421 set remote reverse-step
4422 show remote reverse-step
4423 Control use of remote protocol 'bs' (reverse-step) packet.
4425 set displaced-stepping
4426 show displaced-stepping
4427 Control displaced stepping mode. Displaced stepping is a way to
4428 single-step over breakpoints without removing them from the debuggee.
4429 Also known as "out-of-line single-stepping".
4432 show debug displaced
4433 Control display of debugging info for displaced stepping.
4435 maint set internal-error
4436 maint show internal-error
4437 Control what GDB does when an internal error is detected.
4439 maint set internal-warning
4440 maint show internal-warning
4441 Control what GDB does when an internal warning is detected.
4446 Use a wrapper program to launch programs for debugging.
4448 set multiple-symbols (all|ask|cancel)
4449 show multiple-symbols
4450 The value of this variable can be changed to adjust the debugger behavior
4451 when an expression or a breakpoint location contains an ambiguous symbol
4452 name (an overloaded function name, for instance).
4454 set breakpoint always-inserted
4455 show breakpoint always-inserted
4456 Keep breakpoints always inserted in the target, as opposed to inserting
4457 them when resuming the target, and removing them when the target stops.
4458 This option can improve debugger performance on slow remote targets.
4460 set arm fallback-mode (arm|thumb|auto)
4461 show arm fallback-mode
4462 set arm force-mode (arm|thumb|auto)
4464 These commands control how ARM GDB determines whether instructions
4465 are ARM or Thumb. The default for both settings is auto, which uses
4466 the current CPSR value for instructions without symbols; previous
4467 versions of GDB behaved as if "set arm fallback-mode arm".
4469 set disable-randomization
4470 show disable-randomization
4471 Standalone programs run with the virtual address space randomization enabled
4472 by default on some platforms. This option keeps the addresses stable across
4473 multiple debugging sessions.
4477 Control whether other threads are stopped or not when some thread hits
4482 Requests that asynchronous execution is enabled in the target, if available.
4483 In this case, it's possible to resume target in the background, and interact
4484 with GDB while the target is running. "show target-async" displays the
4485 current state of asynchronous execution of the target.
4487 set target-wide-charset
4488 show target-wide-charset
4489 The target-wide-charset is the name of the character set that GDB
4490 uses when printing characters whose type is wchar_t.
4492 set tcp auto-retry (on|off)
4494 set tcp connect-timeout
4495 show tcp connect-timeout
4496 These commands allow GDB to retry failed TCP connections to a remote stub
4497 with a specified timeout period; this is useful if the stub is launched
4498 in parallel with GDB but may not be ready to accept connections immediately.
4500 set libthread-db-search-path
4501 show libthread-db-search-path
4502 Control list of directories which GDB will search for appropriate
4505 set schedule-multiple (on|off)
4506 show schedule-multiple
4507 Allow GDB to resume all threads of all processes or only threads of
4508 the current process.
4512 Use more aggressive caching for accesses to the stack. This improves
4513 performance of remote debugging (particularly backtraces) without
4514 affecting correctness.
4516 set interactive-mode (on|off|auto)
4517 show interactive-mode
4518 Control whether GDB runs in interactive mode (on) or not (off).
4519 When in interactive mode, GDB waits for the user to answer all
4520 queries. Otherwise, GDB does not wait and assumes the default
4521 answer. When set to auto (the default), GDB determines which
4522 mode to use based on the stdin settings.
4527 For program forks, this is replaced by the new more generic `info
4528 inferiors' command. To list checkpoints, you can still use the
4529 `info checkpoints' command, which was an alias for the `info forks'
4533 Replaced by the new `inferior' command. To switch between
4534 checkpoints, you can still use the `restart' command, which was an
4535 alias for the `fork' command.
4538 This is removed, since some targets don't have a notion of
4539 processes. To switch between processes, you can still use the
4540 `inferior' command using GDB's own inferior number.
4543 For program forks, this is replaced by the new more generic `kill
4544 inferior' command. To delete a checkpoint, you can still use the
4545 `delete checkpoint' command, which was an alias for the `delete
4549 For program forks, this is replaced by the new more generic `detach
4550 inferior' command. To detach a checkpoint, you can still use the
4551 `detach checkpoint' command, which was an alias for the `detach
4554 * New native configurations
4556 x86/x86_64 Darwin i[34567]86-*-darwin*
4558 x86_64 MinGW x86_64-*-mingw*
4562 Lattice Mico32 lm32-*
4563 x86 DICOS i[34567]86-*-dicos*
4564 x86_64 DICOS x86_64-*-dicos*
4567 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4568 (mingw32ce) debugging.
4574 These commands were actually not implemented on any target.
4576 *** Changes in GDB 6.8
4578 * New native configurations
4580 NetBSD/hppa hppa*-*netbsd*
4581 Xtensa GNU/Linux xtensa*-*-linux*
4585 NetBSD/hppa hppa*-*-netbsd*
4586 Xtensa GNU/Lunux xtensa*-*-linux*
4588 * Change in command line behavior -- corefiles vs. process ids.
4590 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4591 attaching to process NUMBER fails, GDB no longer attempts to open a
4592 core file named NUMBER. Attaching to a program using the -c option
4593 is no longer supported. Instead, use the '-p' or '--pid' options.
4595 * GDB can now be built as a native debugger for debugging Windows x86
4596 (mingw32) Portable Executable (PE) programs.
4598 * Pending breakpoints no longer change their number when their address
4601 * GDB now supports breakpoints with multiple locations,
4602 including breakpoints on C++ constructors, inside C++ templates,
4603 and in inlined functions.
4605 * GDB's ability to debug optimized code has been improved. GDB more
4606 accurately identifies function bodies and lexical blocks that occupy
4607 more than one contiguous range of addresses.
4609 * Target descriptions can now describe registers for PowerPC.
4611 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4612 registers on PowerPC targets.
4614 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4615 targets even when the libthread_db library is not available.
4617 * The GDB remote stub, gdbserver, now supports the new file transfer
4618 commands (remote put, remote get, and remote delete).
4620 * The GDB remote stub, gdbserver, now supports run and attach in
4621 extended-remote mode.
4623 * hppa*64*-*-hpux11* target broken
4624 The debugger is unable to start a program and fails with the following
4625 error: "Error trying to get information about dynamic linker".
4626 The gdb-6.7 release is also affected.
4628 * GDB now supports the --enable-targets= configure option to allow
4629 building a single GDB executable that supports multiple remote
4630 target architectures.
4632 * GDB now supports debugging C and C++ programs which use the
4633 Decimal Floating Point extension. In addition, the PowerPC target
4634 now has a set of pseudo-registers to inspect decimal float values
4635 stored in two consecutive float registers.
4637 * The -break-insert MI command can optionally create pending
4640 * Improved support for debugging Ada
4641 Many improvements to the Ada language support have been made. These
4643 - Better support for Ada2005 interface types
4644 - Improved handling of arrays and slices in general
4645 - Better support for Taft-amendment types
4646 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4648 - Improved command completion in Ada
4651 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4656 set print frame-arguments (all|scalars|none)
4657 show print frame-arguments
4658 The value of this variable can be changed to control which argument
4659 values should be printed by the debugger when displaying a frame.
4664 Transfer files to and from a remote target, and delete remote files.
4671 Transfer files to and from a remote target, and delete remote files.
4673 * New remote packets
4680 Open, close, read, write, and delete files on the remote system.
4683 Attach to an existing process on the remote system, in extended-remote
4687 Run a new process on the remote system, in extended-remote mode.
4689 *** Changes in GDB 6.7
4691 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4692 bfd, libiberty and opcodes, as revealed by static analysis donated by
4693 Coverity, Inc. (http://scan.coverity.com).
4695 * When looking up multiply-defined global symbols, GDB will now prefer the
4696 symbol definition in the current shared library if it was built using the
4697 -Bsymbolic linker option.
4699 * When the Text User Interface (TUI) is not configured, GDB will now
4700 recognize the -tui command-line option and print a message that the TUI
4703 * The GDB remote stub, gdbserver, now has lower overhead for high
4704 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4706 * GDB for MIPS targets now autodetects whether a remote target provides
4707 32-bit or 64-bit register values.
4709 * Support for C++ member pointers has been improved.
4711 * GDB now understands XML target descriptions, which specify the
4712 target's overall architecture. GDB can read a description from
4713 a local file or over the remote serial protocol.
4715 * Vectors of single-byte data use a new integer type which is not
4716 automatically displayed as character or string data.
4718 * The /s format now works with the print command. It displays
4719 arrays of single-byte integers and pointers to single-byte integers
4722 * Target descriptions can now describe target-specific registers,
4723 for architectures which have implemented the support (currently
4724 only ARM, M68K, and MIPS).
4726 * GDB and the GDB remote stub, gdbserver, now support the XScale
4729 * The GDB remote stub, gdbserver, has been updated to support
4730 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4731 has been rewritten to use the standard GDB remote protocol.
4733 * GDB can now step into C++ functions which are called through thunks.
4735 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4737 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4738 layout. It also supports a TextSeg= and DataSeg= response when only
4739 segment base addresses (rather than offsets) are available.
4741 * The /i format now outputs any trailing branch delay slot instructions
4742 immediately following the last instruction within the count specified.
4744 * The GDB remote protocol "T" stop reply packet now supports a
4745 "library" response. Combined with the new "qXfer:libraries:read"
4746 packet, this response allows GDB to debug shared libraries on targets
4747 where the operating system manages the list of loaded libraries (e.g.
4748 Windows and SymbianOS).
4750 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4751 (DLLs) on Windows and Windows CE targets.
4753 * GDB now supports a faster verification that a .debug file matches its binary
4754 according to its build-id signature, if the signature is present.
4760 Enable or disable hardware flow control (RTS/CTS) on the serial port
4761 when debugging using remote targets.
4763 set mem inaccessible-by-default
4764 show mem inaccessible-by-default
4765 If the target supplies a memory map, for instance via the remote
4766 protocol's "qXfer:memory-map:read" packet, setting this variable
4767 prevents GDB from accessing memory outside the memory map. This
4768 is useful for targets with memory mapped registers or which react
4769 badly to accesses of unmapped address space.
4771 set breakpoint auto-hw
4772 show breakpoint auto-hw
4773 If the target supplies a memory map, for instance via the remote
4774 protocol's "qXfer:memory-map:read" packet, setting this variable
4775 lets GDB use hardware breakpoints automatically for memory regions
4776 where it can not use software breakpoints. This covers both the
4777 "break" command and internal breakpoints used for other commands
4778 including "next" and "finish".
4781 catch exception unhandled
4782 Stop the program execution when Ada exceptions are raised.
4785 Stop the program execution when an Ada assertion failed.
4789 Set an alternate system root for target files. This is a more
4790 general version of "set solib-absolute-prefix", which is now
4791 an alias to "set sysroot".
4794 Provide extended SPU facility status information. This set of
4795 commands is available only when debugging the Cell/B.E. SPU
4798 * New native configurations
4800 OpenBSD/sh sh*-*openbsd*
4803 unset tdesc filename
4805 Use the specified local file as an XML target description, and do
4806 not query the target for its built-in description.
4810 OpenBSD/sh sh*-*-openbsd*
4811 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4812 Toshiba Media Processor mep-elf
4814 * New remote packets
4817 Ignore the specified signals; pass them directly to the debugged program
4818 without stopping other threads or reporting them to GDB.
4820 qXfer:features:read:
4821 Read an XML target description from the target, which describes its
4826 Read or write contents of an spufs file on the target system. These
4827 packets are available only on the Cell/B.E. SPU architecture.
4829 qXfer:libraries:read:
4830 Report the loaded shared libraries. Combined with new "T" packet
4831 response, this packet allows GDB to debug shared libraries on
4832 targets where the operating system manages the list of loaded
4833 libraries (e.g. Windows and SymbianOS).
4837 Support for these obsolete configurations has been removed.
4845 i[34567]86-*-lynxos*
4846 i[34567]86-*-netware*
4847 i[34567]86-*-sco3.2v5*
4848 i[34567]86-*-sco3.2v4*
4850 i[34567]86-*-sysv4.2*
4853 i[34567]86-*-unixware2*
4854 i[34567]86-*-unixware*
4863 * Other removed features
4870 Various m68k-only ROM monitors.
4877 Various Renesas ROM monitors and debugging interfaces for SH and
4882 Support for a Macraigor serial interface to on-chip debugging.
4883 GDB does not directly support the newer parallel or USB
4888 A debug information format. The predecessor to DWARF 2 and
4889 DWARF 3, which are still supported.
4891 Support for the HP aCC compiler on HP-UX/PA-RISC
4893 SOM-encapsulated symbolic debugging information, automatic
4894 invocation of pxdb, and the aCC custom C++ ABI. This does not
4895 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4896 with aCC can still be debugged on an assembly level.
4898 MIPS ".pdr" sections
4900 A MIPS-specific format used to describe stack frame layout
4901 in debugging information.
4905 GDB could work with an older version of Guile to debug
4906 the interpreter and Scheme programs running in it.
4908 set mips stack-arg-size
4909 set mips saved-gpreg-size
4911 Use "set mips abi" to control parameter passing for MIPS.
4913 *** Changes in GDB 6.6
4918 Cell Broadband Engine SPU spu-elf
4920 * GDB can now be configured as a cross-debugger targeting native Windows
4921 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4922 running on a Windows system over TCP/IP to debug Windows programs.
4924 * The GDB remote stub, gdbserver, has been updated to support Windows and
4925 Cygwin debugging. Both single-threaded and multi-threaded programs are
4928 * The "set trust-readonly-sections" command works again. This command was
4929 broken in GDB 6.3, 6.4, and 6.5.
4931 * The "load" command now supports writing to flash memory, if the remote
4932 stub provides the required support.
4934 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4935 longer requires symbolic debug information (e.g. DWARF-2).
4940 unset substitute-path
4941 show substitute-path
4942 Manage a list of substitution rules that GDB uses to rewrite the name
4943 of the directories where the sources are located. This can be useful
4944 for instance when the sources were moved to a different location
4945 between compilation and debugging.
4949 Print each CLI command as it is executed. Each command is prefixed with
4950 a number of `+' symbols representing the nesting depth.
4951 The source command now has a `-v' option to enable the same feature.
4955 The ARM Demon monitor support (RDP protocol, "target rdp").
4957 Kernel Object Display, an embedded debugging feature which only worked with
4958 an obsolete version of Cisco IOS.
4960 The 'set download-write-size' and 'show download-write-size' commands.
4962 * New remote packets
4965 Tell a stub about GDB client features, and request remote target features.
4966 The first feature implemented is PacketSize, which allows the target to
4967 specify the size of packets it can handle - to minimize the number of
4968 packets required and improve performance when connected to a remote
4972 Fetch an OS auxilliary vector from the remote stub. This packet is a
4973 more efficient replacement for qPart:auxv:read.
4975 qXfer:memory-map:read:
4976 Fetch a memory map from the remote stub, including information about
4977 RAM, ROM, and flash memory devices.
4982 Erase and program a flash memory device.
4984 * Removed remote packets
4987 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4988 used it, and only gdbserver implemented it.
4990 *** Changes in GDB 6.5
4994 Renesas M32C/M16C m32c-elf
4996 Morpho Technologies ms1 ms1-elf
5000 init-if-undefined Initialize a convenience variable, but
5001 only if it doesn't already have a value.
5003 The following commands are presently only implemented for native GNU/Linux:
5005 checkpoint Save a snapshot of the program state.
5007 restart <n> Return the program state to a
5008 previously saved state.
5010 info checkpoints List currently saved checkpoints.
5012 delete-checkpoint <n> Delete a previously saved checkpoint.
5014 set|show detach-on-fork Tell gdb whether to detach from a newly
5015 forked process, or to keep debugging it.
5017 info forks List forks of the user program that
5018 are available to be debugged.
5020 fork <n> Switch to debugging one of several
5021 forks of the user program that are
5022 available to be debugged.
5024 delete-fork <n> Delete a fork from the list of forks
5025 that are available to be debugged (and
5026 kill the forked process).
5028 detach-fork <n> Delete a fork from the list of forks
5029 that are available to be debugged (and
5030 allow the process to continue).
5034 Morpho Technologies ms2 ms1-elf
5036 * Improved Windows host support
5038 GDB now builds as a cross debugger hosted on i686-mingw32, including
5039 native console support, and remote communications using either
5040 network sockets or serial ports.
5042 * Improved Modula-2 language support
5044 GDB can now print most types in the Modula-2 syntax. This includes:
5045 basic types, set types, record types, enumerated types, range types,
5046 pointer types and ARRAY types. Procedure var parameters are correctly
5047 printed and hexadecimal addresses and character constants are also
5048 written in the Modula-2 syntax. Best results can be obtained by using
5049 GNU Modula-2 together with the -gdwarf-2 command line option.
5053 The ARM rdi-share module.
5055 The Netware NLM debug server.
5057 *** Changes in GDB 6.4
5059 * New native configurations
5061 OpenBSD/arm arm*-*-openbsd*
5062 OpenBSD/mips64 mips64-*-openbsd*
5066 Morpho Technologies ms1 ms1-elf
5068 * New command line options
5070 --batch-silent As for --batch, but totally silent.
5071 --return-child-result The debugger will exist with the same value
5072 the child (debugged) program exited with.
5073 --eval-command COMMAND, -ex COMMAND
5074 Execute a single GDB CLI command. This may be
5075 specified multiple times and in conjunction
5076 with the --command (-x) option.
5078 * Deprecated commands removed
5080 The following commands, that were deprecated in 2000, have been
5084 set|show arm disassembly-flavor set|show arm disassembler
5085 othernames set arm disassembler
5086 set|show remotedebug set|show debug remote
5087 set|show archdebug set|show debug arch
5088 set|show eventdebug set|show debug event
5091 * New BSD user-level threads support
5093 It is now possible to debug programs using the user-level threads
5094 library on OpenBSD and FreeBSD. Currently supported (target)
5097 FreeBSD/amd64 x86_64-*-freebsd*
5098 FreeBSD/i386 i386-*-freebsd*
5099 OpenBSD/i386 i386-*-openbsd*
5101 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5102 are not yet supported.
5104 * New support for Matsushita MN10300 w/sim added
5105 (Work in progress). mn10300-elf.
5107 * REMOVED configurations and files
5109 VxWorks and the XDR protocol *-*-vxworks
5110 Motorola MCORE mcore-*-*
5111 National Semiconductor NS32000 ns32k-*-*
5113 * New "set print array-indexes" command
5115 After turning this setting "on", GDB prints the index of each element
5116 when displaying arrays. The default is "off" to preserve the previous
5119 * VAX floating point support
5121 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5123 * User-defined command support
5125 In addition to using $arg0..$arg9 for argument passing, it is now possible
5126 to use $argc to determine now many arguments have been passed. See the
5127 section on user-defined commands in the user manual for more information.
5129 *** Changes in GDB 6.3:
5131 * New command line option
5133 GDB now accepts -l followed by a number to set the timeout for remote
5136 * GDB works with GCC -feliminate-dwarf2-dups
5138 GDB now supports a more compact representation of DWARF-2 debug
5139 information using DW_FORM_ref_addr references. These are produced
5140 by GCC with the option -feliminate-dwarf2-dups and also by some
5141 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5142 to use -feliminate-dwarf2-dups.
5144 * Internationalization
5146 When supported by the host system, GDB will be built with
5147 internationalization (libintl). The task of marking up the sources is
5148 continued, we're looking forward to our first translation.
5152 Initial support for debugging programs compiled with the GNAT
5153 implementation of the Ada programming language has been integrated
5154 into GDB. In this release, support is limited to expression evaluation.
5156 * New native configurations
5158 GNU/Linux/m32r m32r-*-linux-gnu
5162 GDB's remote protocol now includes support for the 'p' packet. This
5163 packet is used to fetch individual registers from a remote inferior.
5165 * END-OF-LIFE registers[] compatibility module
5167 GDB's internal register infrastructure has been completely rewritten.
5168 The new infrastructure making possible the implementation of key new
5169 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5172 GDB 6.3 will be the last release to include the the registers[]
5173 compatibility module that allowed out-of-date configurations to
5174 continue to work. This change directly impacts the following
5184 powerpc bdm protocol
5186 Unless there is activity to revive these configurations, they will be
5187 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5189 * OBSOLETE configurations and files
5191 Configurations that have been declared obsolete in this release have
5192 been commented out. Unless there is activity to revive these
5193 configurations, the next release of GDB will have their sources
5194 permanently REMOVED.
5203 *** Changes in GDB 6.2.1:
5205 * MIPS `break main; run' gave an heuristic-fence-post warning
5207 When attempting to run even a simple program, a warning about
5208 heuristic-fence-post being hit would be reported. This problem has
5211 * MIPS IRIX 'long double' crashed GDB
5213 When examining a long double variable, GDB would get a segmentation
5214 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5215 IRIX long double values).
5219 A bug in the VAX stack code was causing problems with the "next"
5220 command. This problem has been fixed.
5222 *** Changes in GDB 6.2:
5224 * Fix for ``many threads''
5226 On GNU/Linux systems that use the NPTL threads library, a program
5227 rapidly creating and deleting threads would confuse GDB leading to the
5230 ptrace: No such process.
5231 thread_db_get_info: cannot get thread info: generic error
5233 This problem has been fixed.
5235 * "-async" and "-noasync" options removed.
5237 Support for the broken "-noasync" option has been removed (it caused
5240 * New ``start'' command.
5242 This command runs the program until the begining of the main procedure.
5244 * New BSD Kernel Data Access Library (libkvm) interface
5246 Using ``target kvm'' it is now possible to debug kernel core dumps and
5247 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5248 platforms. Currently supported (native-only) configurations are:
5250 FreeBSD/amd64 x86_64-*-freebsd*
5251 FreeBSD/i386 i?86-*-freebsd*
5252 NetBSD/i386 i?86-*-netbsd*
5253 NetBSD/m68k m68*-*-netbsd*
5254 NetBSD/sparc sparc-*-netbsd*
5255 OpenBSD/amd64 x86_64-*-openbsd*
5256 OpenBSD/i386 i?86-*-openbsd*
5257 OpenBSD/m68k m68*-openbsd*
5258 OpenBSD/sparc sparc-*-openbsd*
5260 * Signal trampoline code overhauled
5262 Many generic problems with GDB's signal handling code have been fixed.
5263 These include: backtraces through non-contiguous stacks; recognition
5264 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5265 call; backtrace through a signal trampoline; step into and out of
5266 signal handlers; and single-stepping in the signal trampoline.
5268 Please note that kernel bugs are a limiting factor here. These
5269 features have been shown to work on an s390 GNU/Linux system that
5270 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5272 * Cygwin support for DWARF 2 added.
5274 * New native configurations
5276 GNU/Linux/hppa hppa*-*-linux*
5277 OpenBSD/hppa hppa*-*-openbsd*
5278 OpenBSD/m68k m68*-*-openbsd*
5279 OpenBSD/m88k m88*-*-openbsd*
5280 OpenBSD/powerpc powerpc-*-openbsd*
5281 NetBSD/vax vax-*-netbsd*
5282 OpenBSD/vax vax-*-openbsd*
5284 * END-OF-LIFE frame compatibility module
5286 GDB's internal frame infrastructure has been completely rewritten.
5287 The new infrastructure making it possible to support key new features
5288 including DWARF 2 Call Frame Information. To aid in the task of
5289 migrating old configurations to this new infrastructure, a
5290 compatibility module, that allowed old configurations to continue to
5291 work, was also included.
5293 GDB 6.2 will be the last release to include this frame compatibility
5294 module. This change directly impacts the following configurations:
5304 Unless there is activity to revive these configurations, they will be
5305 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5307 * REMOVED configurations and files
5309 Sun 3, running SunOS 3 m68*-*-sunos3*
5310 Sun 3, running SunOS 4 m68*-*-sunos4*
5311 Sun 2, running SunOS 3 m68000-*-sunos3*
5312 Sun 2, running SunOS 4 m68000-*-sunos4*
5313 Motorola 680x0 running LynxOS m68*-*-lynxos*
5314 AT&T 3b1/Unix pc m68*-att-*
5315 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5316 decstation mips-dec-* mips-little-*
5317 riscos mips-*-riscos* mips-*-sysv*
5318 sonymips mips-sony-*
5319 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5321 *** Changes in GDB 6.1.1:
5323 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5325 The TUI (Text-mode User Interface) is now built as part of a default
5326 GDB configuration. It is enabled by either selecting the TUI with the
5327 command line option "-i=tui" or by running the separate "gdbtui"
5328 program. For more information on the TUI, see the manual "Debugging
5331 * Pending breakpoint support (also included in GDB 6.1)
5333 Support has been added to allow you to specify breakpoints in shared
5334 libraries that have not yet been loaded. If a breakpoint location
5335 cannot be found, and the "breakpoint pending" option is set to auto,
5336 GDB queries you if you wish to make the breakpoint pending on a future
5337 shared-library load. If and when GDB resolves the breakpoint symbol,
5338 the pending breakpoint is removed as one or more regular breakpoints
5341 Pending breakpoints are very useful for GCJ Java debugging.
5343 * Fixed ISO-C build problems
5345 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5346 non ISO-C code that stopped them being built using a more strict ISO-C
5347 compiler (e.g., IBM's C compiler).
5349 * Fixed build problem on IRIX 5
5351 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5352 wasn't able to compile compile on an IRIX 5 system.
5354 * Added execute permission to gdb/gdbserver/configure
5356 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5357 permission. This bug would cause configure to fail on a number of
5358 systems (Solaris, IRIX). Ref: server/519.
5360 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5362 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5363 has been updated to use constant array sizes.
5365 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5367 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5368 its generated DWARF Call Frame Info. This encoding was causing GDB to
5369 panic, that panic has been fixed. Ref: gdb/1628.
5371 * Fixed a problem when examining parameters in shared library code.
5373 When examining parameters in optimized shared library code generated
5374 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5375 not available''. GDB now correctly displays the variable's value.
5377 *** Changes in GDB 6.1:
5379 * Removed --with-mmalloc
5381 Support for the mmalloc memory manager has been removed, as it
5382 conflicted with the internal gdb byte cache.
5384 * Changes in AMD64 configurations
5386 The AMD64 target now includes the %cs and %ss registers. As a result
5387 the AMD64 remote protocol has changed; this affects the floating-point
5388 and SSE registers. If you rely on those registers for your debugging,
5389 you should upgrade gdbserver on the remote side.
5391 * Revised SPARC target
5393 The SPARC target has been completely revised, incorporating the
5394 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5395 support for LynxOS and SunOS 4 has been dropped. Calling functions
5396 from within GDB on operating systems with a non-executable stack
5397 (Solaris, OpenBSD) now works.
5401 GDB has a new C++ demangler which does a better job on the mangled
5402 names generated by current versions of g++. It also runs faster, so
5403 with this and other changes gdb should now start faster on large C++
5406 * DWARF 2 Location Expressions
5408 GDB support for location expressions has been extended to support function
5409 arguments and frame bases. Older versions of GDB could crash when they
5412 * C++ nested types and namespaces
5414 GDB's support for nested types and namespaces in C++ has been
5415 improved, especially if you use the DWARF 2 debugging format. (This
5416 is the default for recent versions of GCC on most platforms.)
5417 Specifically, if you have a class "Inner" defined within a class or
5418 namespace "Outer", then GDB realizes that the class's name is
5419 "Outer::Inner", not simply "Inner". This should greatly reduce the
5420 frequency of complaints about not finding RTTI symbols. In addition,
5421 if you are stopped at inside of a function defined within a namespace,
5422 GDB modifies its name lookup accordingly.
5424 * New native configurations
5426 NetBSD/amd64 x86_64-*-netbsd*
5427 OpenBSD/amd64 x86_64-*-openbsd*
5428 OpenBSD/alpha alpha*-*-openbsd*
5429 OpenBSD/sparc sparc-*-openbsd*
5430 OpenBSD/sparc64 sparc64-*-openbsd*
5432 * New debugging protocols
5434 M32R with SDI protocol m32r-*-elf*
5436 * "set prompt-escape-char" command deleted.
5438 The command "set prompt-escape-char" has been deleted. This command,
5439 and its very obscure effet on GDB's prompt, was never documented,
5440 tested, nor mentioned in the NEWS file.
5442 * OBSOLETE configurations and files
5444 Configurations that have been declared obsolete in this release have
5445 been commented out. Unless there is activity to revive these
5446 configurations, the next release of GDB will have their sources
5447 permanently REMOVED.
5449 Sun 3, running SunOS 3 m68*-*-sunos3*
5450 Sun 3, running SunOS 4 m68*-*-sunos4*
5451 Sun 2, running SunOS 3 m68000-*-sunos3*
5452 Sun 2, running SunOS 4 m68000-*-sunos4*
5453 Motorola 680x0 running LynxOS m68*-*-lynxos*
5454 AT&T 3b1/Unix pc m68*-att-*
5455 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5456 decstation mips-dec-* mips-little-*
5457 riscos mips-*-riscos* mips-*-sysv*
5458 sonymips mips-sony-*
5459 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5461 * REMOVED configurations and files
5463 SGI Irix-4.x mips-sgi-irix4 or iris4
5464 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5465 Z8000 simulator z8k-zilog-none or z8ksim
5466 Matsushita MN10200 w/simulator mn10200-*-*
5467 H8/500 simulator h8500-hitachi-hms or h8500hms
5468 HP/PA running BSD hppa*-*-bsd*
5469 HP/PA running OSF/1 hppa*-*-osf*
5470 HP/PA Pro target hppa*-*-pro*
5471 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5472 386BSD i[3456]86-*-bsd*
5473 Sequent family i[3456]86-sequent-sysv4*
5474 i[3456]86-sequent-sysv*
5475 i[3456]86-sequent-bsd*
5476 SPARC running LynxOS sparc-*-lynxos*
5477 SPARC running SunOS 4 sparc-*-sunos4*
5478 Tsqware Sparclet sparclet-*-*
5479 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5481 *** Changes in GDB 6.0:
5485 Support for debugging the Objective-C programming language has been
5486 integrated into GDB.
5488 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5490 DWARF 2's Call Frame Information makes available compiler generated
5491 information that more exactly describes the program's run-time stack.
5492 By using this information, GDB is able to provide more robust stack
5495 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5496 have been updated to use a new backtrace mechanism which includes
5497 DWARF 2 CFI support.
5501 GDB's remote protocol has been extended to include support for hosted
5502 file I/O (where the remote target uses GDB's file system). See GDB's
5503 remote protocol documentation for details.
5505 * All targets using the new architecture framework.
5507 All of GDB's targets have been updated to use the new internal
5508 architecture framework. The way is now open for future GDB releases
5509 to include cross-architecture native debugging support (i386 on amd64,
5512 * GNU/Linux's Thread Local Storage (TLS)
5514 GDB now includes support for for the GNU/Linux implementation of
5515 per-thread variables.
5517 * GNU/Linux's Native POSIX Thread Library (NPTL)
5519 GDB's thread code has been updated to work with either the new
5520 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5522 * Separate debug info.
5524 GDB, in conjunction with BINUTILS, now supports a mechanism for
5525 automatically loading debug information from a separate file. Instead
5526 of shipping full debug and non-debug versions of system libraries,
5527 system integrators can now instead ship just the stripped libraries
5528 and optional debug files.
5530 * DWARF 2 Location Expressions
5532 DWARF 2 Location Expressions allow the compiler to more completely
5533 describe the location of variables (even in optimized code) to the
5536 GDB now includes preliminary support for location expressions (support
5537 for DW_OP_piece is still missing).
5541 A number of long standing bugs that caused GDB to die while starting a
5542 Java application have been fixed. GDB's Java support is now
5543 considered "useable".
5545 * GNU/Linux support for fork, vfork, and exec.
5547 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5548 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5551 * GDB supports logging output to a file
5553 There are two new commands, "set logging" and "show logging", which can be
5554 used to capture GDB's output to a file.
5556 * The meaning of "detach" has changed for gdbserver
5558 The "detach" command will now resume the application, as documented. To
5559 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5562 * d10v, m68hc11 `regs' command deprecated
5564 The `info registers' command has been updated so that it displays the
5565 registers using a format identical to the old `regs' command.
5569 A new command, "maint set profile on/off", has been added. This command can
5570 be used to enable or disable profiling while running GDB, to profile a
5571 session or a set of commands. In addition there is a new configure switch,
5572 "--enable-profiling", which will cause GDB to be compiled with profiling
5573 data, for more informative profiling results.
5575 * Default MI syntax changed to "mi2".
5577 The default MI (machine interface) syntax, enabled by the command line
5578 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5579 "mi1", can be enabled by specifying the option "-i=mi1".
5581 Support for the original "mi0" syntax (included in GDB 5.0) has been
5584 Fix for gdb/192: removed extraneous space when displaying frame level.
5585 Fix for gdb/672: update changelist is now output in mi list format.
5586 Fix for gdb/702: a -var-assign that updates the value now shows up
5587 in a subsequent -var-update.
5589 * New native configurations.
5591 FreeBSD/amd64 x86_64-*-freebsd*
5593 * Multi-arched targets.
5595 HP/PA HPUX11 hppa*-*-hpux*
5596 Renesas M32R/D w/simulator m32r-*-elf*
5598 * OBSOLETE configurations and files
5600 Configurations that have been declared obsolete in this release have
5601 been commented out. Unless there is activity to revive these
5602 configurations, the next release of GDB will have their sources
5603 permanently REMOVED.
5605 Z8000 simulator z8k-zilog-none or z8ksim
5606 Matsushita MN10200 w/simulator mn10200-*-*
5607 H8/500 simulator h8500-hitachi-hms or h8500hms
5608 HP/PA running BSD hppa*-*-bsd*
5609 HP/PA running OSF/1 hppa*-*-osf*
5610 HP/PA Pro target hppa*-*-pro*
5611 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5612 Sequent family i[3456]86-sequent-sysv4*
5613 i[3456]86-sequent-sysv*
5614 i[3456]86-sequent-bsd*
5615 Tsqware Sparclet sparclet-*-*
5616 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5618 * REMOVED configurations and files
5621 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5622 IBM AIX PS/2 i[3456]86-*-aix
5623 i386 running Mach 3.0 i[3456]86-*-mach3*
5624 i386 running Mach i[3456]86-*-mach*
5625 i386 running OSF/1 i[3456]86-*osf1mk*
5626 HP/Apollo 68k Family m68*-apollo*-sysv*,
5628 m68*-hp-bsd*, m68*-hp-hpux*
5629 Argonaut Risc Chip (ARC) arc-*-*
5630 Mitsubishi D30V d30v-*-*
5631 Fujitsu FR30 fr30-*-elf*
5632 OS/9000 i[34]86-*-os9k
5633 I960 with MON960 i960-*-coff
5635 * MIPS $fp behavior changed
5637 The convenience variable $fp, for the MIPS, now consistently returns
5638 the address of the current frame's base. Previously, depending on the
5639 context, $fp could refer to either $sp or the current frame's base
5640 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5641 The GNU Source-Level Debugger''.
5643 *** Changes in GDB 5.3:
5645 * GNU/Linux shared library multi-threaded performance improved.
5647 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5648 `/proc', in preference to `ptrace' for memory reads. This may result
5649 in an improvement in the start-up time of multi-threaded, shared
5650 library applications when run under GDB. One GDB user writes: ``loads
5651 shared libs like mad''.
5653 * ``gdbserver'' now supports multi-threaded applications on some targets
5655 Support for debugging multi-threaded applications which use
5656 the GNU/Linux LinuxThreads package has been added for
5657 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5658 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5660 * GDB now supports C/C++ preprocessor macros.
5662 GDB now expands preprocessor macro invocations in C/C++ expressions,
5663 and provides various commands for showing macro definitions and how
5666 The new command `macro expand EXPRESSION' expands any macro
5667 invocations in expression, and shows the result.
5669 The new command `show macro MACRO-NAME' shows the definition of the
5670 macro named MACRO-NAME, and where it was defined.
5672 Most compilers don't include information about macros in the debugging
5673 information by default. In GCC 3.1, for example, you need to compile
5674 your program with the options `-gdwarf-2 -g3'. If the macro
5675 information is present in the executable, GDB will read it.
5677 * Multi-arched targets.
5679 DEC Alpha (partial) alpha*-*-*
5680 DEC VAX (partial) vax-*-*
5682 National Semiconductor NS32000 (partial) ns32k-*-*
5683 Motorola 68000 (partial) m68k-*-*
5684 Motorola MCORE mcore-*-*
5688 Fujitsu FRV architecture added by Red Hat frv*-*-*
5691 * New native configurations
5693 Alpha NetBSD alpha*-*-netbsd*
5694 SH NetBSD sh*-*-netbsdelf*
5695 MIPS NetBSD mips*-*-netbsd*
5696 UltraSPARC NetBSD sparc64-*-netbsd*
5698 * OBSOLETE configurations and files
5700 Configurations that have been declared obsolete in this release have
5701 been commented out. Unless there is activity to revive these
5702 configurations, the next release of GDB will have their sources
5703 permanently REMOVED.
5705 Mitsubishi D30V d30v-*-*
5706 OS/9000 i[34]86-*-os9k
5707 IBM AIX PS/2 i[3456]86-*-aix
5708 Fujitsu FR30 fr30-*-elf*
5709 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5710 Argonaut Risc Chip (ARC) arc-*-*
5711 i386 running Mach 3.0 i[3456]86-*-mach3*
5712 i386 running Mach i[3456]86-*-mach*
5713 i386 running OSF/1 i[3456]86-*osf1mk*
5714 HP/Apollo 68k Family m68*-apollo*-sysv*,
5716 m68*-hp-bsd*, m68*-hp-hpux*
5717 I960 with MON960 i960-*-coff
5719 * OBSOLETE languages
5721 CHILL, a Pascal like language used by telecommunications companies.
5723 * REMOVED configurations and files
5725 AMD 29k family via UDI a29k-amd-udi, udi29k
5726 A29K VxWorks a29k-*-vxworks
5727 AMD 29000 embedded, using EBMON a29k-none-none
5728 AMD 29000 embedded with COFF a29k-none-coff
5729 AMD 29000 embedded with a.out a29k-none-aout
5731 testsuite/gdb.hp/gdb.threads-hp/ directory
5733 * New command "set max-user-call-depth <nnn>"
5735 This command allows the user to limit the call depth of user-defined
5736 commands. The default is 1024.
5738 * Changes in FreeBSD/i386 native debugging.
5740 Support for the "generate-core-file" has been added.
5742 * New commands "dump", "append", and "restore".
5744 These commands allow data to be copied from target memory
5745 to a bfd-format or binary file (dump and append), and back
5746 from a file into memory (restore).
5748 * Improved "next/step" support on multi-processor Alpha Tru64.
5750 The previous single-step mechanism could cause unpredictable problems,
5751 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5752 of a software single-step mechanism prevents this.
5754 *** Changes in GDB 5.2.1:
5762 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5763 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5764 Fix, by Joel Brobecker imported from mainline.
5766 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5767 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5768 Fix, by Fred Fish, imported from mainline.
5770 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5771 Surprisingly enough, it works now.
5772 By Michal Ludvig, imported from mainline.
5774 i386 hardware watchpoint support:
5775 avoid misses on second run for some targets.
5776 By Pierre Muller, imported from mainline.
5778 *** Changes in GDB 5.2:
5780 * New command "set trust-readonly-sections on[off]".
5782 This command is a hint that tells gdb that read-only sections
5783 really are read-only (ie. that their contents will not change).
5784 In this mode, gdb will go to the object file rather than the
5785 target to read memory from read-only sections (such as ".text").
5786 This can be a significant performance improvement on some
5787 (notably embedded) targets.
5789 * New command "generate-core-file" (or "gcore").
5791 This new gdb command allows the user to drop a core file of the child
5792 process state at any time. So far it's been implemented only for
5793 GNU/Linux and Solaris, but should be relatively easily ported to other
5794 hosts. Argument is core file name (defaults to core.<pid>).
5796 * New command line option
5798 GDB now accepts --pid or -p followed by a process id.
5800 * Change in command line behavior -- corefiles vs. process ids.
5802 There is a subtle behavior in the way in which GDB handles
5803 command line arguments. The first non-flag argument is always
5804 a program to debug, but the second non-flag argument may either
5805 be a corefile or a process id. Previously, GDB would attempt to
5806 open the second argument as a corefile, and if that failed, would
5807 issue a superfluous error message and then attempt to attach it as
5808 a process. Now, if the second argument begins with a non-digit,
5809 it will be treated as a corefile. If it begins with a digit,
5810 GDB will attempt to attach it as a process, and if no such process
5811 is found, will then attempt to open it as a corefile.
5813 * Changes in ARM configurations.
5815 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5816 configuration is fully multi-arch.
5818 * New native configurations
5820 ARM NetBSD arm*-*-netbsd*
5821 x86 OpenBSD i[3456]86-*-openbsd*
5822 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5823 Sparc64 running FreeBSD sparc64-*-freebsd*
5827 Sanyo XStormy16 xstormy16-elf
5829 * OBSOLETE configurations and files
5831 Configurations that have been declared obsolete in this release have
5832 been commented out. Unless there is activity to revive these
5833 configurations, the next release of GDB will have their sources
5834 permanently REMOVED.
5836 AMD 29k family via UDI a29k-amd-udi, udi29k
5837 A29K VxWorks a29k-*-vxworks
5838 AMD 29000 embedded, using EBMON a29k-none-none
5839 AMD 29000 embedded with COFF a29k-none-coff
5840 AMD 29000 embedded with a.out a29k-none-aout
5842 testsuite/gdb.hp/gdb.threads-hp/ directory
5844 * REMOVED configurations and files
5846 TI TMS320C80 tic80-*-*
5848 PowerPC Solaris powerpcle-*-solaris*
5849 PowerPC Windows NT powerpcle-*-cygwin32
5850 PowerPC Netware powerpc-*-netware*
5851 Harris/CXUX m88k m88*-harris-cxux*
5852 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5853 ns32k-utek-sysv* ns32k-utek-*
5854 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5855 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5856 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5857 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5858 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5860 * Changes to command line processing
5862 The new `--args' feature can be used to specify command-line arguments
5863 for the inferior from gdb's command line.
5865 * Changes to key bindings
5867 There is a new `operate-and-get-next' function bound to `C-o'.
5869 *** Changes in GDB 5.1.1
5871 Fix compile problem on DJGPP.
5873 Fix a problem with floating-point registers on the i386 being
5876 Fix to stop GDB crashing on .debug_str debug info.
5878 Numerous documentation fixes.
5880 Numerous testsuite fixes.
5882 *** Changes in GDB 5.1:
5884 * New native configurations
5886 Alpha FreeBSD alpha*-*-freebsd*
5887 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5888 MIPS GNU/Linux mips*-*-linux*
5889 MIPS SGI Irix 6.x mips*-sgi-irix6*
5890 ia64 AIX ia64-*-aix*
5891 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5895 Motorola 68HC11 and 68HC12 m68hc11-elf
5897 UltraSparc running GNU/Linux sparc64-*-linux*
5899 * OBSOLETE configurations and files
5901 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5902 Harris/CXUX m88k m88*-harris-cxux*
5903 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5904 ns32k-utek-sysv* ns32k-utek-*
5905 TI TMS320C80 tic80-*-*
5907 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5908 PowerPC Solaris powerpcle-*-solaris*
5909 PowerPC Windows NT powerpcle-*-cygwin32
5910 PowerPC Netware powerpc-*-netware*
5911 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5912 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5913 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5914 Apple Macintosh (MPW) host N/A
5916 stuff.c (Program to stuff files into a specially prepared space in kdb)
5917 kdb-start.c (Main loop for the standalone kernel debugger)
5919 Configurations that have been declared obsolete in this release have
5920 been commented out. Unless there is activity to revive these
5921 configurations, the next release of GDB will have their sources
5922 permanently REMOVED.
5924 * REMOVED configurations and files
5926 Altos 3068 m68*-altos-*
5927 Convex c1-*-*, c2-*-*
5929 ARM RISCix arm-*-* (as host)
5933 * GDB has been converted to ISO C.
5935 GDB's source code has been converted to ISO C. In particular, the
5936 sources are fully protoized, and rely on standard headers being
5941 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5943 * The MI enabled by default.
5945 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5946 revised and enabled by default. Packages which use GDB as a debugging
5947 engine behind a UI or another front end are encouraged to switch to
5948 using the GDB/MI interface, instead of the old annotations interface
5949 which is now deprecated.
5951 * Support for debugging Pascal programs.
5953 GDB now includes support for debugging Pascal programs. The following
5954 main features are supported:
5956 - Pascal-specific data types such as sets;
5958 - automatic recognition of Pascal sources based on file-name
5961 - Pascal-style display of data types, variables, and functions;
5963 - a Pascal expression parser.
5965 However, some important features are not yet supported.
5967 - Pascal string operations are not supported at all;
5969 - there are some problems with boolean types;
5971 - Pascal type hexadecimal constants are not supported
5972 because they conflict with the internal variables format;
5974 - support for Pascal objects and classes is not full yet;
5976 - unlike Pascal, GDB is case-sensitive for symbol names.
5978 * Changes in completion.
5980 Commands such as `shell', `run' and `set args', which pass arguments
5981 to inferior programs, now complete on file names, similar to what
5982 users expect at the shell prompt.
5984 Commands which accept locations, such as `disassemble', `print',
5985 `breakpoint', `until', etc. now complete on filenames as well as
5986 program symbols. Thus, if you type "break foob TAB", and the source
5987 files linked into the programs include `foobar.c', that file name will
5988 be one of the candidates for completion. However, file names are not
5989 considered for completion after you typed a colon that delimits a file
5990 name from a name of a function in that file, as in "break foo.c:bar".
5992 `set demangle-style' completes on available demangling styles.
5994 * New platform-independent commands:
5996 It is now possible to define a post-hook for a command as well as a
5997 hook that runs before the command. For more details, see the
5998 documentation of `hookpost' in the GDB manual.
6000 * Changes in GNU/Linux native debugging.
6002 Support for debugging multi-threaded programs has been completely
6003 revised for all platforms except m68k and sparc. You can now debug as
6004 many threads as your system allows you to have.
6006 Attach/detach is supported for multi-threaded programs.
6008 Support for SSE registers was added for x86. This doesn't work for
6009 multi-threaded programs though.
6011 * Changes in MIPS configurations.
6013 Multi-arch support is enabled for all MIPS configurations.
6015 GDB can now be built as native debugger on SGI Irix 6.x systems for
6016 debugging n32 executables. (Debugging 64-bit executables is not yet
6019 * Unified support for hardware watchpoints in all x86 configurations.
6021 Most (if not all) native x86 configurations support hardware-assisted
6022 breakpoints and watchpoints in a unified manner. This support
6023 implements debug register sharing between watchpoints, which allows to
6024 put a virtually infinite number of watchpoints on the same address,
6025 and also supports watching regions up to 16 bytes with several debug
6028 The new maintenance command `maintenance show-debug-regs' toggles
6029 debugging print-outs in functions that insert, remove, and test
6030 watchpoints and hardware breakpoints.
6032 * Changes in the DJGPP native configuration.
6034 New command ``info dos sysinfo'' displays assorted information about
6035 the CPU, OS, memory, and DPMI server.
6037 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6038 display information about segment descriptors stored in GDT, LDT, and
6041 New commands ``info dos pde'' and ``info dos pte'' display entries
6042 from Page Directory and Page Tables (for now works with CWSDPMI only).
6043 New command ``info dos address-pte'' displays the Page Table entry for
6044 a given linear address.
6046 GDB can now pass command lines longer than 126 characters to the
6047 program being debugged (requires an update to the libdbg.a library
6048 which is part of the DJGPP development kit).
6050 DWARF2 debug info is now supported.
6052 It is now possible to `step' and `next' through calls to `longjmp'.
6054 * Changes in documentation.
6056 All GDB documentation was converted to GFDL, the GNU Free
6057 Documentation License.
6059 Tracepoints-related commands are now fully documented in the GDB
6062 TUI, the Text-mode User Interface, is now documented in the manual.
6064 Tracepoints-related commands are now fully documented in the GDB
6067 The "GDB Internals" manual now has an index. It also includes
6068 documentation of `ui_out' functions, GDB coding standards, x86
6069 hardware watchpoints, and memory region attributes.
6071 * GDB's version number moved to ``version.in''
6073 The Makefile variable VERSION has been replaced by the file
6074 ``version.in''. People creating GDB distributions should update the
6075 contents of this file.
6079 GUD support is now a standard part of the EMACS distribution.
6081 *** Changes in GDB 5.0:
6083 * Improved support for debugging FP programs on x86 targets
6085 Unified and much-improved support for debugging floating-point
6086 programs on all x86 targets. In particular, ``info float'' now
6087 displays the FP registers in the same format on all x86 targets, with
6088 greater level of detail.
6090 * Improvements and bugfixes in hardware-assisted watchpoints
6092 It is now possible to watch array elements, struct members, and
6093 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6094 on x86 targets no longer erroneously trigger when the address is
6097 * Improvements in the native DJGPP version of GDB
6099 The distribution now includes all the scripts and auxiliary files
6100 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6101 machines ``out of the box''.
6103 The DJGPP version can now debug programs that use signals. It is
6104 possible to catch signals that happened in the debuggee, deliver
6105 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6106 would kill the program being debugged.) Programs that hook hardware
6107 interrupts (keyboard, timer, etc.) can also be debugged.
6109 It is now possible to debug DJGPP programs that redirect their
6110 standard handles or switch them to raw (as opposed to cooked) mode, or
6111 even close them. The command ``run < foo > bar'' works as expected,
6112 and ``info terminal'' reports useful information about the debuggee's
6113 terminal, including raw/cooked mode, redirection, etc.
6115 The DJGPP version now uses termios functions for console I/O, which
6116 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6119 DOS-style file names with drive letters are now fully supported by
6122 It is now possible to debug DJGPP programs that switch their working
6123 directory. It is also possible to rerun the debuggee any number of
6124 times without restarting GDB; thus, you can use the same setup,
6125 breakpoints, etc. for many debugging sessions.
6127 * New native configurations
6129 ARM GNU/Linux arm*-*-linux*
6130 PowerPC GNU/Linux powerpc-*-linux*
6134 Motorola MCore mcore-*-*
6135 x86 VxWorks i[3456]86-*-vxworks*
6136 PowerPC VxWorks powerpc-*-vxworks*
6137 TI TMS320C80 tic80-*-*
6139 * OBSOLETE configurations
6141 Altos 3068 m68*-altos-*
6142 Convex c1-*-*, c2-*-*
6144 ARM RISCix arm-*-* (as host)
6147 Configurations that have been declared obsolete will be commented out,
6148 but the code will be left in place. If there is no activity to revive
6149 these configurations before the next release of GDB, the sources will
6150 be permanently REMOVED.
6152 * Gould support removed
6154 Support for the Gould PowerNode and NP1 has been removed.
6156 * New features for SVR4
6158 On SVR4 native platforms (such as Solaris), if you attach to a process
6159 without first loading a symbol file, GDB will now attempt to locate and
6160 load symbols from the running process's executable file.
6162 * Many C++ enhancements
6164 C++ support has been greatly improved. Overload resolution now works properly
6165 in almost all cases. RTTI support is on the way.
6167 * Remote targets can connect to a sub-program
6169 A popen(3) style serial-device has been added. This device starts a
6170 sub-process (such as a stand-alone simulator) and then communicates
6171 with that. The sub-program to run is specified using the syntax
6172 ``|<program> <args>'' vis:
6174 (gdb) set remotedebug 1
6175 (gdb) target extended-remote |mn10300-elf-sim program-args
6177 * MIPS 64 remote protocol
6179 A long standing bug in the mips64 remote protocol where by GDB
6180 expected certain 32 bit registers (ex SR) to be transfered as 32
6181 instead of 64 bits has been fixed.
6183 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6184 added to provide backward compatibility with older versions of GDB.
6186 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6188 The command ``set remotebinarydownload'' command has been replaced by
6189 ``set remote X-packet''. Other commands in ``set remote'' family
6190 include ``set remote P-packet''.
6192 * Breakpoint commands accept ranges.
6194 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6195 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6196 ``tracepoint passcount'' also accepts a range of tracepoints.
6198 * ``apropos'' command added.
6200 The ``apropos'' command searches through command names and
6201 documentation strings, printing out matches, making it much easier to
6202 try to find a command that does what you are looking for.
6206 A new machine oriented interface (MI) has been added to GDB. This
6207 interface is designed for debug environments running GDB as a separate
6208 process. This is part of the long term libGDB project. See the
6209 "GDB/MI" chapter of the GDB manual for further information. It can be
6210 enabled by configuring with:
6212 .../configure --enable-gdbmi
6214 *** Changes in GDB-4.18:
6216 * New native configurations
6218 HP-UX 10.20 hppa*-*-hpux10.20
6219 HP-UX 11.x hppa*-*-hpux11.0*
6220 M68K GNU/Linux m68*-*-linux*
6224 Fujitsu FR30 fr30-*-elf*
6225 Intel StrongARM strongarm-*-*
6226 Mitsubishi D30V d30v-*-*
6228 * OBSOLETE configurations
6230 Gould PowerNode, NP1 np1-*-*, pn-*-*
6232 Configurations that have been declared obsolete will be commented out,
6233 but the code will be left in place. If there is no activity to revive
6234 these configurations before the next release of GDB, the sources will
6235 be permanently REMOVED.
6239 As a compatibility experiment, GDB's source files buildsym.h and
6240 buildsym.c have been converted to pure standard C, no longer
6241 containing any K&R compatibility code. We believe that all systems in
6242 use today either come with a standard C compiler, or have a GCC port
6243 available. If this is not true, please report the affected
6244 configuration to bug-gdb@gnu.org immediately. See the README file for
6245 information about getting a standard C compiler if you don't have one
6250 GDB now uses readline 2.2.
6252 * set extension-language
6254 You can now control the mapping between filename extensions and source
6255 languages by using the `set extension-language' command. For instance,
6256 you can ask GDB to treat .c files as C++ by saying
6257 set extension-language .c c++
6258 The command `info extensions' lists all of the recognized extensions
6259 and their associated languages.
6261 * Setting processor type for PowerPC and RS/6000
6263 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6264 you can use the `set processor' command to specify what variant of the
6265 PowerPC family you are debugging. The command
6269 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6270 following PowerPC and RS6000 variants:
6272 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6273 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6275 403GC IBM PowerPC 403GC
6276 505 Motorola PowerPC 505
6277 860 Motorola PowerPC 860 or 850
6278 601 Motorola PowerPC 601
6279 602 Motorola PowerPC 602
6280 603 Motorola/IBM PowerPC 603 or 603e
6281 604 Motorola PowerPC 604 or 604e
6282 750 Motorola/IBM PowerPC 750 or 750
6284 At the moment, this command just tells GDB what to name the
6285 special-purpose processor registers. Since almost all the affected
6286 registers are inaccessible to user-level programs, this command is
6287 only useful for remote debugging in its present form.
6291 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6292 more extensive support for HP-UX. Added features include shared
6293 library support, kernel threads and hardware watchpoints for 11.00,
6294 support for HP's ANSI C and C++ compilers, and a compatibility mode
6295 for xdb and dbx commands.
6299 HP's donation includes the new concept of catchpoints, which is a
6300 generalization of the old catch command. On HP-UX, it is now possible
6301 to catch exec, fork, and vfork, as well as library loading.
6303 This means that the existing catch command has changed; its first
6304 argument now specifies the type of catch to be set up. See the
6305 output of "help catch" for a list of catchpoint types.
6307 * Debugging across forks
6309 On HP-UX, you can choose which process to debug when a fork() happens
6314 HP has donated a curses-based terminal user interface (TUI). To get
6315 it, build with --enable-tui. Although this can be enabled for any
6316 configuration, at present it only works for native HP debugging.
6318 * GDB remote protocol additions
6320 A new protocol packet 'X' that writes binary data is now available.
6321 Default behavior is to try 'X', then drop back to 'M' if the stub
6322 fails to respond. The settable variable `remotebinarydownload'
6323 allows explicit control over the use of 'X'.
6325 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6326 full 64-bit address. The command
6328 set remoteaddresssize 32
6330 can be used to revert to the old behaviour. For existing remote stubs
6331 the change should not be noticed, as the additional address information
6334 In order to assist in debugging stubs, you may use the maintenance
6335 command `packet' to send any text string to the stub. For instance,
6337 maint packet heythere
6339 sends the packet "$heythere#<checksum>". Note that it is very easy to
6340 disrupt a debugging session by sending the wrong packet at the wrong
6343 The compare-sections command allows you to compare section data on the
6344 target to what is in the executable file without uploading or
6345 downloading, by comparing CRC checksums.
6347 * Tracing can collect general expressions
6349 You may now collect general expressions at tracepoints. This requires
6350 further additions to the target-side stub; see tracepoint.c and
6351 doc/agentexpr.texi for further details.
6353 * mask-address variable for Mips
6355 For Mips targets, you may control the zeroing of the upper 32 bits of
6356 a 64-bit address by entering `set mask-address on'. This is mainly
6357 of interest to users of embedded R4xxx and R5xxx processors.
6359 * Higher serial baud rates
6361 GDB's serial code now allows you to specify baud rates 57600, 115200,
6362 230400, and 460800 baud. (Note that your host system may not be able
6363 to achieve all of these rates.)
6367 The i960 configuration now includes an initial implementation of a
6368 builtin simulator, contributed by Jim Wilson.
6371 *** Changes in GDB-4.17:
6373 * New native configurations
6375 Alpha GNU/Linux alpha*-*-linux*
6376 Unixware 2.x i[3456]86-unixware2*
6377 Irix 6.x mips*-sgi-irix6*
6378 PowerPC GNU/Linux powerpc-*-linux*
6379 PowerPC Solaris powerpcle-*-solaris*
6380 Sparc GNU/Linux sparc-*-linux*
6381 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6385 Argonaut Risc Chip (ARC) arc-*-*
6386 Hitachi H8/300S h8300*-*-*
6387 Matsushita MN10200 w/simulator mn10200-*-*
6388 Matsushita MN10300 w/simulator mn10300-*-*
6389 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6390 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6391 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6392 Mitsubishi D10V w/simulator d10v-*-*
6393 Mitsubishi M32R/D w/simulator m32r-*-elf*
6394 Tsqware Sparclet sparclet-*-*
6395 NEC V850 w/simulator v850-*-*
6397 * New debugging protocols
6399 ARM with RDI protocol arm*-*-*
6400 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6401 DDB and LSI variants of PMON protocol mips*-*-*
6402 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6403 PowerPC with SDS protocol powerpc{,le}-*-eabi
6404 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6408 All configurations can now understand and use the DWARF 2 debugging
6409 format. The choice is automatic, if the symbol file contains DWARF 2
6414 GDB now includes basic Java language support. This support is
6415 only useful with Java compilers that produce native machine code.
6417 * solib-absolute-prefix and solib-search-path
6419 For SunOS and SVR4 shared libraries, you may now set the prefix for
6420 loading absolute shared library symbol files, and the search path for
6421 locating non-absolute shared library symbol files.
6423 * Live range splitting
6425 GDB can now effectively debug code for which GCC has performed live
6426 range splitting as part of its optimization. See gdb/doc/LRS for
6427 more details on the expected format of the stabs information.
6431 GDB's support for the GNU Hurd, including thread debugging, has been
6432 updated to work with current versions of the Hurd.
6436 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6437 instruction set. ARM GDB automatically detects when Thumb
6438 instructions are in use, and adjusts disassembly and backtracing
6443 GDB's MIPS target configurations now handle the MIP16 16-bit
6448 GDB now includes support for overlays; if an executable has been
6449 linked such that multiple sections are based at the same address, GDB
6450 will decide which section to use for symbolic info. You can choose to
6451 control the decision manually, using overlay commands, or implement
6452 additional target-side support and use "overlay load-target" to bring
6453 in the overlay mapping. Do "help overlay" for more detail.
6457 The command "info symbol <address>" displays information about
6458 the symbol at the specified address.
6462 The standard remote protocol now includes an extension that allows
6463 asynchronous collection and display of trace data. This requires
6464 extensive support in the target-side debugging stub. Tracing mode
6465 includes a new interaction mode in GDB and new commands: see the
6466 file tracepoint.c for more details.
6470 Configurations for embedded MIPS now include a simulator contributed
6471 by Cygnus Solutions. The simulator supports the instruction sets
6472 of most MIPS variants.
6476 Sparc configurations may now include the ERC32 simulator contributed
6477 by the European Space Agency. The simulator is not built into
6478 Sparc targets by default; configure with --enable-sim to include it.
6482 For target configurations that may include multiple variants of a
6483 basic architecture (such as MIPS and SH), you may now set the
6484 architecture explicitly. "set arch" sets, "info arch" lists
6485 the possible architectures.
6487 *** Changes in GDB-4.16:
6489 * New native configurations
6491 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6492 M68K NetBSD m68k-*-netbsd*
6493 PowerPC AIX 4.x powerpc-*-aix*
6494 PowerPC MacOS powerpc-*-macos*
6495 PowerPC Windows NT powerpcle-*-cygwin32
6496 RS/6000 AIX 4.x rs6000-*-aix4*
6500 ARM with RDP protocol arm-*-*
6501 I960 with MON960 i960-*-coff
6502 MIPS VxWorks mips*-*-vxworks*
6503 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6504 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6506 Matra Sparclet sparclet-*-*
6510 The powerpc-eabi configuration now includes the PSIM simulator,
6511 contributed by Andrew Cagney, with assistance from Mike Meissner.
6512 PSIM is a very elaborate model of the PowerPC, including not only
6513 basic instruction set execution, but also details of execution unit
6514 performance and I/O hardware. See sim/ppc/README for more details.
6518 GDB now works with Solaris 2.5.
6520 * Windows 95/NT native
6522 GDB will now work as a native debugger on Windows 95 and Windows NT.
6523 To build it from source, you must use the "gnu-win32" environment,
6524 which uses a DLL to emulate enough of Unix to run the GNU tools.
6525 Further information, binaries, and sources are available at
6526 ftp.cygnus.com, under pub/gnu-win32.
6528 * dont-repeat command
6530 If a user-defined command includes the command `dont-repeat', then the
6531 command will not be repeated if the user just types return. This is
6532 useful if the command is time-consuming to run, so that accidental
6533 extra keystrokes don't run the same command many times.
6535 * Send break instead of ^C
6537 The standard remote protocol now includes an option to send a break
6538 rather than a ^C to the target in order to interrupt it. By default,
6539 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6541 * Remote protocol timeout
6543 The standard remote protocol includes a new variable `remotetimeout'
6544 that allows you to set the number of seconds before GDB gives up trying
6545 to read from the target. The default value is 2.
6547 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6549 By default GDB will automatically keep track of objects as they are
6550 loaded and unloaded by the dynamic linker. By using the command `set
6551 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6552 when shared library events occur, thus allowing you to set breakpoints
6553 in shared libraries which are explicitly loaded by the inferior.
6555 Note this feature does not work on hpux8. On hpux9 you must link
6556 /usr/lib/end.o into your program. This feature should work
6557 automatically on hpux10.
6559 * Irix 5.x hardware watchpoint support
6561 Irix 5 configurations now support the use of hardware watchpoints.
6563 * Mips protocol "SYN garbage limit"
6565 When debugging a Mips target using the `target mips' protocol, you
6566 may set the number of characters that GDB will ignore by setting
6567 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6568 every character. The default value is 1050.
6570 * Recording and replaying remote debug sessions
6572 If you set `remotelogfile' to the name of a file, gdb will write to it
6573 a recording of a remote debug session. This recording may then be
6574 replayed back to gdb using "gdbreplay". See gdbserver/README for
6575 details. This is useful when you have a problem with GDB while doing
6576 remote debugging; you can make a recording of the session and send it
6577 to someone else, who can then recreate the problem.
6579 * Speedups for remote debugging
6581 GDB includes speedups for downloading and stepping MIPS systems using
6582 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6583 and more efficient S-record downloading.
6585 * Memory use reductions and statistics collection
6587 GDB now uses less memory and reports statistics about memory usage.
6588 Try the `maint print statistics' command, for example.
6590 *** Changes in GDB-4.15:
6592 * Psymtabs for XCOFF
6594 The symbol reader for AIX GDB now uses partial symbol tables. This
6595 can greatly improve startup time, especially for large executables.
6597 * Remote targets use caching
6599 Remote targets now use a data cache to speed up communication with the
6600 remote side. The data cache could lead to incorrect results because
6601 it doesn't know about volatile variables, thus making it impossible to
6602 debug targets which use memory mapped I/O devices. `set remotecache
6603 off' turns the the data cache off.
6605 * Remote targets may have threads
6607 The standard remote protocol now includes support for multiple threads
6608 in the target system, using new protocol commands 'H' and 'T'. See
6609 gdb/remote.c for details.
6613 If GDB is configured with `--enable-netrom', then it will include
6614 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6615 acts as though it is a bank of ROM on the target board, but you can
6616 write into it over the network. GDB's support consists only of
6617 support for fast loading into the emulated ROM; to debug, you must use
6618 another protocol, such as standard remote protocol. The usual
6619 sequence is something like
6621 target nrom <netrom-hostname>
6623 target remote <netrom-hostname>:1235
6627 GDB now includes support for the Apple Macintosh, as a host only. It
6628 may be run as either an MPW tool or as a standalone application, and
6629 it can debug through the serial port. All the usual GDB commands are
6630 available, but to the target command, you must supply "serial" as the
6631 device type instead of "/dev/ttyXX". See mpw-README in the main
6632 directory for more information on how to build. The MPW configuration
6633 scripts */mpw-config.in support only a few targets, and only the
6634 mips-idt-ecoff target has been tested.
6638 GDB configuration now uses autoconf. This is not user-visible,
6639 but does simplify configuration and building.
6643 GDB now supports hpux10.
6645 *** Changes in GDB-4.14:
6647 * New native configurations
6649 x86 FreeBSD i[345]86-*-freebsd
6650 x86 NetBSD i[345]86-*-netbsd
6651 NS32k NetBSD ns32k-*-netbsd
6652 Sparc NetBSD sparc-*-netbsd
6656 A29K VxWorks a29k-*-vxworks
6657 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6658 CPU32 EST-300 emulator m68*-*-est*
6659 PowerPC ELF powerpc-*-elf
6662 * Alpha OSF/1 support for procfs
6664 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6665 possible to attach to running processes. As the mounting of the /proc
6666 filesystem is optional on the Alpha, GDB automatically determines
6667 the availability of /proc during startup. This can lead to problems
6668 if /proc is unmounted after GDB has been started.
6670 * Arguments to user-defined commands
6672 User commands may accept up to 10 arguments separated by whitespace.
6673 Arguments are accessed within the user command via $arg0..$arg9. A
6676 print $arg0 + $arg1 + $arg2
6678 To execute the command use:
6681 Defines the command "adder" which prints the sum of its three arguments.
6682 Note the arguments are text substitutions, so they may reference variables,
6683 use complex expressions, or even perform inferior function calls.
6685 * New `if' and `while' commands
6687 This makes it possible to write more sophisticated user-defined
6688 commands. Both commands take a single argument, which is the
6689 expression to evaluate, and must be followed by the commands to
6690 execute, one per line, if the expression is nonzero, the list being
6691 terminated by the word `end'. The `if' command list may include an
6692 `else' word, which causes the following commands to be executed only
6693 if the expression is zero.
6695 * Fortran source language mode
6697 GDB now includes partial support for Fortran 77. It will recognize
6698 Fortran programs and can evaluate a subset of Fortran expressions, but
6699 variables and functions may not be handled correctly. GDB will work
6700 with G77, but does not yet know much about symbols emitted by other
6703 * Better HPUX support
6705 Most debugging facilities now work on dynamic executables for HPPAs
6706 running hpux9 or later. You can attach to running dynamically linked
6707 processes, but by default the dynamic libraries will be read-only, so
6708 for instance you won't be able to put breakpoints in them. To change
6709 that behavior do the following before running the program:
6715 This will cause the libraries to be mapped private and read-write.
6716 To revert to the normal behavior, do this:
6722 You cannot set breakpoints or examine data in the library until after
6723 the library is loaded if the function/data symbols do not have
6726 GDB can now also read debug symbols produced by the HP C compiler on
6727 HPPAs (sorry, no C++, Fortran or 68k support).
6729 * Target byte order now dynamically selectable
6731 You can choose which byte order to use with a target system, via the
6732 commands "set endian big" and "set endian little", and you can see the
6733 current setting by using "show endian". You can also give the command
6734 "set endian auto", in which case GDB will use the byte order
6735 associated with the executable. Currently, only embedded MIPS
6736 configurations support dynamic selection of target byte order.
6738 * New DOS host serial code
6740 This version uses DPMI interrupts to handle buffered I/O, so you
6741 no longer need to run asynctsr when debugging boards connected to
6744 *** Changes in GDB-4.13:
6746 * New "complete" command
6748 This lists all the possible completions for the rest of the line, if it
6749 were to be given as a command itself. This is intended for use by emacs.
6751 * Trailing space optional in prompt
6753 "set prompt" no longer adds a space for you after the prompt you set. This
6754 allows you to set a prompt which ends in a space or one that does not.
6756 * Breakpoint hit counts
6758 "info break" now displays a count of the number of times the breakpoint
6759 has been hit. This is especially useful in conjunction with "ignore"; you
6760 can ignore a large number of breakpoint hits, look at the breakpoint info
6761 to see how many times the breakpoint was hit, then run again, ignoring one
6762 less than that number, and this will get you quickly to the last hit of
6765 * Ability to stop printing at NULL character
6767 "set print null-stop" will cause GDB to stop printing the characters of
6768 an array when the first NULL is encountered. This is useful when large
6769 arrays actually contain only short strings.
6771 * Shared library breakpoints
6773 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6774 breakpoints in shared libraries before the executable is run.
6776 * Hardware watchpoints
6778 There is a new hardware breakpoint for the watch command for sparclite
6779 targets. See gdb/sparclite/hw_breakpoint.note.
6781 Hardware watchpoints are also now supported under GNU/Linux.
6785 Annotations have been added. These are for use with graphical interfaces,
6786 and are still experimental. Currently only gdba.el uses these.
6788 * Improved Irix 5 support
6790 GDB now works properly with Irix 5.2.
6792 * Improved HPPA support
6794 GDB now works properly with the latest GCC and GAS.
6796 * New native configurations
6798 Sequent PTX4 i[34]86-sequent-ptx4
6799 HPPA running OSF/1 hppa*-*-osf*
6800 Atari TT running SVR4 m68*-*-sysv4*
6801 RS/6000 LynxOS rs6000-*-lynxos*
6805 OS/9000 i[34]86-*-os9k
6806 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6809 * Hitachi SH7000 and E7000-PC ICE support
6811 There is now support for communicating with the Hitachi E7000-PC ICE.
6812 This is available automatically when GDB is configured for the SH.
6816 As usual, a variety of small fixes and improvements, both generic
6817 and configuration-specific. See the ChangeLog for more detail.
6819 *** Changes in GDB-4.12:
6821 * Irix 5 is now supported
6825 GDB-4.12 on the HPPA has a number of changes which make it unable
6826 to debug the output from the currently released versions of GCC and
6827 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6828 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6829 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6832 *** Changes in GDB-4.11:
6834 * User visible changes:
6838 The "set remotedebug" option is now consistent between the mips remote
6839 target, remote targets using the gdb-specific protocol, UDI (AMD's
6840 debug protocol for the 29k) and the 88k bug monitor. It is now an
6841 integer specifying a debug level (normally 0 or 1, but 2 means more
6842 debugging info for the mips target).
6844 * DEC Alpha native support
6846 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6847 debug info, but GDB works fairly well with the DEC compiler and should
6848 work with a future GCC release. See the README file for a few
6849 Alpha-specific notes.
6851 * Preliminary thread implementation
6853 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6855 * LynxOS native and target support for 386
6857 This release has been hosted on LynxOS 2.2, and also can be configured
6858 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6861 * Improvements in C++ mangling/demangling.
6863 This release has much better g++ debugging, specifically in name
6864 mangling/demangling, virtual function calls, print virtual table,
6865 call methods, ...etc.
6867 *** Changes in GDB-4.10:
6869 * User visible changes:
6871 Remote debugging using the GDB-specific (`target remote') protocol now
6872 supports the `load' command. This is only useful if you have some
6873 other way of getting the stub to the target system, and you can put it
6874 somewhere in memory where it won't get clobbered by the download.
6876 Filename completion now works.
6878 When run under emacs mode, the "info line" command now causes the
6879 arrow to point to the line specified. Also, "info line" prints
6880 addresses in symbolic form (as well as hex).
6882 All vxworks based targets now support a user settable option, called
6883 vxworks-timeout. This option represents the number of seconds gdb
6884 should wait for responses to rpc's. You might want to use this if
6885 your vxworks target is, perhaps, a slow software simulator or happens
6886 to be on the far side of a thin network line.
6890 This release contains support for using a DEC alpha as a GDB host for
6891 cross debugging. Native alpha debugging is not supported yet.
6894 *** Changes in GDB-4.9:
6898 This is the first GDB release which is accompanied by a matching testsuite.
6899 The testsuite requires installation of dejagnu, which should be available
6900 via ftp from most sites that carry GNU software.
6904 'Cfront' style demangling has had its name changed to 'ARM' style, to
6905 emphasize that it was written from the specifications in the C++ Annotated
6906 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6907 disclaimers, it still generated too much confusion with users attempting to
6908 use gdb with AT&T cfront.
6912 GDB now uses a standard remote interface to a simulator library.
6913 So far, the library contains simulators for the Zilog Z8001/2, the
6914 Hitachi H8/300, H8/500 and Super-H.
6916 * New targets supported
6918 H8/300 simulator h8300-hitachi-hms or h8300hms
6919 H8/500 simulator h8500-hitachi-hms or h8500hms
6920 SH simulator sh-hitachi-hms or sh
6921 Z8000 simulator z8k-zilog-none or z8ksim
6922 IDT MIPS board over serial line mips-idt-ecoff
6924 Cross-debugging to GO32 targets is supported. It requires a custom
6925 version of the i386-stub.c module which is integrated with the
6926 GO32 memory extender.
6928 * New remote protocols
6930 MIPS remote debugging protocol.
6932 * New source languages supported
6934 This version includes preliminary support for Chill, a Pascal like language
6935 used by telecommunications companies. Chill support is also being integrated
6936 into the GNU compiler, but we don't know when it will be publically available.
6939 *** Changes in GDB-4.8:
6941 * HP Precision Architecture supported
6943 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6944 version of this support was available as a set of patches from the
6945 University of Utah. GDB does not support debugging of programs
6946 compiled with the HP compiler, because HP will not document their file
6947 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6948 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6950 Many problems in the preliminary version have been fixed.
6952 * Faster and better demangling
6954 We have improved template demangling and fixed numerous bugs in the GNU style
6955 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6956 character types (wchar_t) are now supported. Demangling of each symbol is now
6957 only done once, and is cached when the symbol table for a file is read in.
6958 This results in a small increase in memory usage for C programs, a moderate
6959 increase in memory usage for C++ programs, and a fantastic speedup in
6962 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6963 from the specifications in the Annotated Reference Manual, which AT&T's
6964 compiler does not actually implement.
6966 * G++ multiple inheritance compiler problem
6968 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6969 inheritance lattices was reworked to properly discover ambiguities. We
6970 recently found an example which causes this new algorithm to fail in a
6971 very subtle way, producing bad debug information for those classes.
6972 The file 'gcc.patch' (in this directory) can be applied to gcc to
6973 circumvent the problem. A future GCC release will contain a complete
6976 The previous G++ debug info problem (mentioned below for the gdb-4.7
6977 release) is fixed in gcc version 2.3.2.
6979 * Improved configure script
6981 The `configure' script will now attempt to guess your system type if
6982 you don't supply a host system type. The old scheme of supplying a
6983 host system triplet is preferable over using this. All the magic is
6984 done in the new `config.guess' script. Examine it for details.
6986 We have also brought our configure script much more in line with the FSF's
6987 version. It now supports the --with-xxx options. In particular,
6988 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6989 The resulting GDB will not be able to read arbitrary object file formats --
6990 only the format ``expected'' to be used on the configured target system.
6991 We hope to make this the default in a future release.
6993 * Documentation improvements
6995 There's new internal documentation on how to modify GDB, and how to
6996 produce clean changes to the code. We implore people to read it
6997 before submitting changes.
6999 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7000 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7001 `info' files are also provided. To build `info' files from scratch,
7002 you will need the latest `makeinfo' release, which will be available in
7003 a future texinfo-X.Y release.
7005 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7006 We're not sure exactly which versions have this problem, but it has
7007 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7008 or better. If that isn't possible, there is a patch in
7009 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7010 around this problem.
7014 GDB now supports array constants that can be used in expressions typed in by
7015 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7016 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7019 The new directory `gdb/sparclite' contains a program that demonstrates
7020 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7022 * New native hosts supported
7024 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7025 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7027 * New targets supported
7029 AMD 29k family via UDI a29k-amd-udi or udi29k
7031 * New file formats supported
7033 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7034 HPUX core files, and SCO 3.2v2 core files.
7038 Attaching to processes now works again; thanks for the many bug reports.
7040 We have also stomped on a bunch of core dumps caused by
7041 printf_filtered("%s") problems.
7043 We eliminated a copyright problem on the rpc and ptrace header files
7044 for VxWorks, which was discovered at the last minute during the 4.7
7045 release. You should now be able to build a VxWorks GDB.
7047 You can now interrupt gdb while an attached process is running. This
7048 will cause the attached process to stop, and give control back to GDB.
7050 We fixed problems caused by using too many file descriptors
7051 for reading symbols from object files and libraries. This was
7052 especially a problem for programs that used many (~100) shared
7055 The `step' command now only enters a subroutine if there is line number
7056 information for the subroutine. Otherwise it acts like the `next'
7057 command. Previously, `step' would enter subroutines if there was
7058 any debugging information about the routine. This avoids problems
7059 when using `cc -g1' on MIPS machines.
7061 * Internal improvements
7063 GDB's internal interfaces have been improved to make it easier to support
7064 debugging of multiple languages in the future.
7066 GDB now uses a common structure for symbol information internally.
7067 Minimal symbols (derived from linkage symbols in object files), partial
7068 symbols (from a quick scan of debug information), and full symbols
7069 contain a common subset of information, making it easier to write
7070 shared code that handles any of them.
7072 * New command line options
7074 We now accept --silent as an alias for --quiet.
7078 The memory-mapped-malloc library is now licensed under the GNU Library
7079 General Public License.
7081 *** Changes in GDB-4.7:
7083 * Host/native/target split
7085 GDB has had some major internal surgery to untangle the support for
7086 hosts and remote targets. Now, when you configure GDB for a remote
7087 target, it will no longer load in all of the support for debugging
7088 local programs on the host. When fully completed and tested, this will
7089 ensure that arbitrary host/target combinations are possible.
7091 The primary conceptual shift is to separate the non-portable code in
7092 GDB into three categories. Host specific code is required any time GDB
7093 is compiled on that host, regardless of the target. Target specific
7094 code relates to the peculiarities of the target, but can be compiled on
7095 any host. Native specific code is everything else: it can only be
7096 built when the host and target are the same system. Child process
7097 handling and core file support are two common `native' examples.
7099 GDB's use of /proc for controlling Unix child processes is now cleaner.
7100 It has been split out into a single module under the `target_ops' vector,
7101 plus two native-dependent functions for each system that uses /proc.
7103 * New hosts supported
7105 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7106 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7107 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7109 * New targets supported
7111 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7112 68030 and CPU32 m68030-*-*, m68332-*-*
7114 * New native hosts supported
7116 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7117 (386bsd is not well tested yet)
7118 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7120 * New file formats supported
7122 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7123 supports reading of `a.out.adobe' object files, which are an a.out
7124 format extended with minimal information about multiple sections.
7128 `show copying' is the same as the old `info copying'.
7129 `show warranty' is the same as `info warrantee'.
7130 These were renamed for consistency. The old commands continue to work.
7132 `info handle' is a new alias for `info signals'.
7134 You can now define pre-command hooks, which attach arbitrary command
7135 scripts to any command. The commands in the hook will be executed
7136 prior to the user's command. You can also create a hook which will be
7137 executed whenever the program stops. See gdb.texinfo.
7141 We now deal with Cfront style name mangling, and can even extract type
7142 info from mangled symbols. GDB can automatically figure out which
7143 symbol mangling style your C++ compiler uses.
7145 Calling of methods and virtual functions has been improved as well.
7149 The crash that occured when debugging Sun Ansi-C compiled binaries is
7150 fixed. This was due to mishandling of the extra N_SO stabs output
7153 We also finally got Ultrix 4.2 running in house, and fixed core file
7154 support, with help from a dozen people on the net.
7156 John M. Farrell discovered that the reason that single-stepping was so
7157 slow on all of the Mips based platforms (primarily SGI and DEC) was
7158 that we were trying to demangle and lookup a symbol used for internal
7159 purposes on every instruction that was being stepped through. Changing
7160 the name of that symbol so that it couldn't be mistaken for a C++
7161 mangled symbol sped things up a great deal.
7163 Rich Pixley sped up symbol lookups in general by getting much smarter
7164 about when C++ symbol mangling is necessary. This should make symbol
7165 completion (TAB on the command line) much faster. It's not as fast as
7166 we'd like, but it's significantly faster than gdb-4.6.
7170 A new user controllable variable 'call_scratch_address' can
7171 specify the location of a scratch area to be used when GDB
7172 calls a function in the target. This is necessary because the
7173 usual method of putting the scratch area on the stack does not work
7174 in systems that have separate instruction and data spaces.
7176 We integrated changes to support the 29k UDI (Universal Debugger
7177 Interface), but discovered at the last minute that we didn't have all
7178 of the appropriate copyright paperwork. We are working with AMD to
7179 resolve this, and hope to have it available soon.
7183 We have sped up the remote serial line protocol, especially for targets
7184 with lots of registers. It now supports a new `expedited status' ('T')
7185 message which can be used in place of the existing 'S' status message.
7186 This allows the remote stub to send only the registers that GDB
7187 needs to make a quick decision about single-stepping or conditional
7188 breakpoints, eliminating the need to fetch the entire register set for
7189 each instruction being stepped through.
7191 The GDB remote serial protocol now implements a write-through cache for
7192 registers, only re-reading the registers if the target has run.
7194 There is also a new remote serial stub for SPARC processors. You can
7195 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7196 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7197 processor with a serial port.
7201 Configure.in files have become much easier to read and modify. A new
7202 `table driven' format makes it more obvious what configurations are
7203 supported, and what files each one uses.
7207 There is a new opcodes library which will eventually contain all of the
7208 disassembly routines and opcode tables. At present, it only contains
7209 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7210 disassembler (binutils/objdump) to share these routines.
7212 The libiberty library is now copylefted under the GNU Library General
7213 Public License. This allows more liberal use, and was done so libg++
7214 can use it. This makes no difference to GDB, since the Library License
7215 grants all the rights from the General Public License.
7219 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7220 reference to the stabs symbol info used by the debugger. It is (as far
7221 as we know) the only published document on this fascinating topic. We
7222 encourage you to read it, compare it to the stabs information on your
7223 system, and send improvements on the document in general (to
7224 bug-gdb@prep.ai.mit.edu).
7226 And, of course, many bugs have been fixed.
7229 *** Changes in GDB-4.6:
7231 * Better support for C++ function names
7233 GDB now accepts as input the "demangled form" of C++ overloaded function
7234 names and member function names, and can do command completion on such names
7235 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7236 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7237 Make use of command completion, it is your friend.
7239 GDB also now accepts a variety of C++ mangled symbol formats. They are
7240 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7241 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7242 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7243 for the list of formats.
7245 * G++ symbol mangling problem
7247 Recent versions of gcc have a bug in how they emit debugging information for
7248 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7249 directory) can be applied to gcc to fix the problem. Alternatively, if you
7250 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7251 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7252 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7255 * New 'maintenance' command
7257 All of the commands related to hacking GDB internals have been moved out of
7258 the main command set, and now live behind the 'maintenance' command. This
7259 can also be abbreviated as 'mt'. The following changes were made:
7261 dump-me -> maintenance dump-me
7262 info all-breakpoints -> maintenance info breakpoints
7263 printmsyms -> maintenance print msyms
7264 printobjfiles -> maintenance print objfiles
7265 printpsyms -> maintenance print psymbols
7266 printsyms -> maintenance print symbols
7268 The following commands are new:
7270 maintenance demangle Call internal GDB demangler routine to
7271 demangle a C++ link name and prints the result.
7272 maintenance print type Print a type chain for a given symbol
7274 * Change to .gdbinit file processing
7276 We now read the $HOME/.gdbinit file before processing the argv arguments
7277 (e.g. reading symbol files or core files). This allows global parameters to
7278 be set, which will apply during the symbol reading. The ./.gdbinit is still
7279 read after argv processing.
7281 * New hosts supported
7283 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7285 GNU/Linux support i386-unknown-linux or linux
7287 We are also including code to support the HP/PA running BSD and HPUX. This
7288 is almost guaranteed not to work, as we didn't have time to test or build it
7289 for this release. We are including it so that the more adventurous (or
7290 masochistic) of you can play with it. We also had major problems with the
7291 fact that the compiler that we got from HP doesn't support the -g option.
7294 * New targets supported
7296 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7298 * More smarts about finding #include files
7300 GDB now remembers the compilation directory for all include files, and for
7301 all files from which C is generated (like yacc and lex sources). This
7302 greatly improves GDB's ability to find yacc/lex sources, and include files,
7303 especially if you are debugging your program from a directory different from
7304 the one that contains your sources.
7306 We also fixed a bug which caused difficulty with listing and setting
7307 breakpoints in include files which contain C code. (In the past, you had to
7308 try twice in order to list an include file that you hadn't looked at before.)
7310 * Interesting infernals change
7312 GDB now deals with arbitrary numbers of sections, where the symbols for each
7313 section must be relocated relative to that section's landing place in the
7314 target's address space. This work was needed to support ELF with embedded
7315 stabs used by Solaris-2.0.
7317 * Bug fixes (of course!)
7319 There have been loads of fixes for the following things:
7320 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7321 i960, stabs, DOS(GO32), procfs, etc...
7323 See the ChangeLog for details.
7325 *** Changes in GDB-4.5:
7327 * New machines supported (host and target)
7329 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7331 SGI Irix-4.x mips-sgi-irix4 or iris4
7333 * New malloc package
7335 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7336 Mmalloc is capable of handling mutiple heaps of memory. It is also
7337 capable of saving a heap to a file, and then mapping it back in later.
7338 This can be used to greatly speedup the startup of GDB by using a
7339 pre-parsed symbol table which lives in a mmalloc managed heap. For
7340 more details, please read mmalloc/mmalloc.texi.
7344 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7345 'help info proc' for details.
7347 * MIPS ecoff symbol table format
7349 The code that reads MIPS symbol table format is now supported on all hosts.
7350 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7353 * File name changes for MS-DOS
7355 Many files in the config directories have been renamed to make it easier to
7356 support GDB on MS-DOSe systems (which have very restrictive file name
7357 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7358 environment) is close to working but has some remaining problems. Note
7359 that debugging of DOS programs is not supported, due to limitations
7360 in the ``operating system'', but it can be used to host cross-debugging.
7362 * Cross byte order fixes
7364 Many fixes have been made to support cross debugging of Sparc and MIPS
7365 targets from hosts whose byte order differs.
7367 * New -mapped and -readnow options
7369 If memory-mapped files are available on your system through the 'mmap'
7370 system call, you can use the -mapped option on the `file' or
7371 `symbol-file' commands to cause GDB to write the symbols from your
7372 program into a reusable file. If the program you are debugging is
7373 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7374 Future GDB debugging sessions will notice the presence of this file,
7375 and will quickly map in symbol information from it, rather than reading
7376 the symbol table from the executable program. Using the '-mapped'
7377 option in a GDB `file' or `symbol-file' command has the same effect as
7378 starting GDB with the '-mapped' command-line option.
7380 You can cause GDB to read the entire symbol table immediately by using
7381 the '-readnow' option with any of the commands that load symbol table
7382 information (or on the GDB command line). This makes the command
7383 slower, but makes future operations faster.
7385 The -mapped and -readnow options are typically combined in order to
7386 build a `fred.syms' file that contains complete symbol information.
7387 A simple GDB invocation to do nothing but build a `.syms' file for future
7390 gdb -batch -nx -mapped -readnow programname
7392 The `.syms' file is specific to the host machine on which GDB is run.
7393 It holds an exact image of GDB's internal symbol table. It cannot be
7394 shared across multiple host platforms.
7396 * longjmp() handling
7398 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7399 siglongjmp() without losing control. This feature has not yet been ported to
7400 all systems. It currently works on many 386 platforms, all MIPS-based
7401 platforms (SGI, DECstation, etc), and Sun3/4.
7405 Preliminary work has been put in to support the new Solaris OS from Sun. At
7406 this time, it can control and debug processes, but it is not capable of
7411 As always, many many bug fixes. The major areas were with g++, and mipsread.
7412 People using the MIPS-based platforms should experience fewer mysterious
7413 crashes and trashed symbol tables.
7415 *** Changes in GDB-4.4:
7417 * New machines supported (host and target)
7419 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7421 BSD Reno on Vax vax-dec-bsd
7422 Ultrix on Vax vax-dec-ultrix
7424 * New machines supported (target)
7426 AMD 29000 embedded, using EBMON a29k-none-none
7430 GDB continues to improve its handling of C++. `References' work better.
7431 The demangler has also been improved, and now deals with symbols mangled as
7432 per the Annotated C++ Reference Guide.
7434 GDB also now handles `stabs' symbol information embedded in MIPS
7435 `ecoff' symbol tables. Since the ecoff format was not easily
7436 extensible to handle new languages such as C++, this appeared to be a
7437 good way to put C++ debugging info into MIPS binaries. This option
7438 will be supported in the GNU C compiler, version 2, when it is
7441 * New features for SVR4
7443 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7444 shared libraries. Debugging dynamically linked programs should present
7445 only minor differences from debugging statically linked programs.
7447 The `info proc' command will print out information about any process
7448 on an SVR4 system (including the one you are debugging). At the moment,
7449 it prints the address mappings of the process.
7451 If you bring up GDB on another SVR4 system, please send mail to
7452 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7454 * Better dynamic linking support in SunOS
7456 Reading symbols from shared libraries which contain debugging symbols
7457 now works properly. However, there remain issues such as automatic
7458 skipping of `transfer vector' code during function calls, which
7459 make it harder to debug code in a shared library, than to debug the
7460 same code linked statically.
7464 GDB is now using the latest `getopt' routines from the FSF. This
7465 version accepts the -- prefix for options with long names. GDB will
7466 continue to accept the old forms (-option and +option) as well.
7467 Various single letter abbreviations for options have been explicity
7468 added to the option table so that they won't get overshadowed in the
7469 future by other options that begin with the same letter.
7473 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7474 Many assorted bugs have been handled. Many more remain to be handled.
7475 See the various ChangeLog files (primarily in gdb and bfd) for details.
7478 *** Changes in GDB-4.3:
7480 * New machines supported (host and target)
7482 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7483 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7484 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7486 * Almost SCO Unix support
7488 We had hoped to support:
7489 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7490 (except for core file support), but we discovered very late in the release
7491 that it has problems with process groups that render gdb unusable. Sorry
7492 about that. I encourage people to fix it and post the fixes.
7494 * Preliminary ELF and DWARF support
7496 GDB can read ELF object files on System V Release 4, and can handle
7497 debugging records for C, in DWARF format, in ELF files. This support
7498 is preliminary. If you bring up GDB on another SVR4 system, please
7499 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7504 GDB now uses the latest `readline' library. One user-visible change
7505 is that two tabs will list possible command completions, which previously
7506 required typing M-? (meta-question mark, or ESC ?).
7510 The `stepi' bug that many of you noticed has been squashed.
7511 Many bugs in C++ have been handled. Many more remain to be handled.
7512 See the various ChangeLog files (primarily in gdb and bfd) for details.
7514 * State of the MIPS world (in case you wondered):
7516 GDB can understand the symbol tables emitted by the compilers
7517 supplied by most vendors of MIPS-based machines, including DEC. These
7518 symbol tables are in a format that essentially nobody else uses.
7520 Some versions of gcc come with an assembler post-processor called
7521 mips-tfile. This program is required if you want to do source-level
7522 debugging of gcc-compiled programs. I believe FSF does not ship
7523 mips-tfile with gcc version 1, but it will eventually come with gcc
7526 Debugging of g++ output remains a problem. g++ version 1.xx does not
7527 really support it at all. (If you're lucky, you should be able to get
7528 line numbers and stack traces to work, but no parameters or local
7529 variables.) With some work it should be possible to improve the
7532 When gcc version 2 is released, you will have somewhat better luck.
7533 However, even then you will get confusing results for inheritance and
7536 We will eventually provide full debugging of g++ output on
7537 DECstations. This will probably involve some kind of stabs-in-ecoff
7538 encapulation, but the details have not been worked out yet.
7541 *** Changes in GDB-4.2:
7543 * Improved configuration
7545 Only one copy of `configure' exists now, and it is not self-modifying.
7546 Porting BFD is simpler.
7550 The `step' and `next' commands now only stop at the first instruction
7551 of a source line. This prevents the multiple stops that used to occur
7552 in switch statements, for-loops, etc. `Step' continues to stop if a
7553 function that has debugging information is called within the line.
7557 Lots of small bugs fixed. More remain.
7559 * New host supported (not target)
7561 Intel 386 PC clone running Mach i386-none-mach
7564 *** Changes in GDB-4.1:
7566 * Multiple source language support
7568 GDB now has internal scaffolding to handle several source languages.
7569 It determines the type of each source file from its filename extension,
7570 and will switch expression parsing and number formatting to match the
7571 language of the function in the currently selected stack frame.
7572 You can also specifically set the language to be used, with
7573 `set language c' or `set language modula-2'.
7577 GDB now has preliminary support for the GNU Modula-2 compiler,
7578 currently under development at the State University of New York at
7579 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7580 continue through the fall of 1991 and into 1992.
7582 Other Modula-2 compilers are currently not supported, and attempting to
7583 debug programs compiled with them will likely result in an error as the
7584 symbol table is read. Feel free to work on it, though!
7586 There are hooks in GDB for strict type checking and range checking,
7587 in the `Modula-2 philosophy', but they do not currently work.
7591 GDB can now write to executable and core files (e.g. patch
7592 a variable's value). You must turn this switch on, specify
7593 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7594 by assigning a new value to a variable. Modifications take
7597 * Automatic SunOS shared library reading
7599 When you run your program, GDB automatically determines where its
7600 shared libraries (if any) have been loaded, and reads their symbols.
7601 The `share' command is no longer needed. This also works when
7602 examining core files.
7606 You can specify the number of lines that the `list' command shows.
7609 * New machines supported (host and target)
7611 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7612 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7613 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7615 * New hosts supported (not targets)
7617 IBM RT/PC: romp-ibm-aix or rtpc
7619 * New targets supported (not hosts)
7621 AMD 29000 embedded with COFF a29k-none-coff
7622 AMD 29000 embedded with a.out a29k-none-aout
7623 Ultracomputer remote kernel debug a29k-nyu-kern
7625 * New remote interfaces
7631 *** Changes in GDB-4.0:
7635 Wide output is wrapped at good places to make the output more readable.
7637 Gdb now supports cross-debugging from a host machine of one type to a
7638 target machine of another type. Communication with the target system
7639 is over serial lines. The ``target'' command handles connecting to the
7640 remote system; the ``load'' command will download a program into the
7641 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7642 also supports debugging of realtime processes running under VxWorks,
7643 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7644 stub on the target system.
7646 New CPUs supported include the AMD 29000 and Intel 960.
7648 GDB now reads object files and symbol tables via a ``binary file''
7649 library, which allows a single copy of GDB to debug programs of multiple
7650 object file types such as a.out and coff.
7652 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7653 refcard.dvi and refcard.ps are available to format it).
7656 * Control-Variable user interface simplified
7658 All variables that control the operation of the debugger can be set
7659 by the ``set'' command, and displayed by the ``show'' command.
7661 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7662 ``Show prompt'' produces the response:
7663 Gdb's prompt is new-gdb=>.
7665 What follows are the NEW set commands. The command ``help set'' will
7666 print a complete list of old and new set commands. ``help set FOO''
7667 will give a longer description of the variable FOO. ``show'' will show
7668 all of the variable descriptions and their current settings.
7670 confirm on/off: Enables warning questions for operations that are
7671 hard to recover from, e.g. rerunning the program while
7672 it is already running. Default is ON.
7674 editing on/off: Enables EMACS style command line editing
7675 of input. Previous lines can be recalled with
7676 control-P, the current line can be edited with control-B,
7677 you can search for commands with control-R, etc.
7680 history filename NAME: NAME is where the gdb command history
7681 will be stored. The default is .gdb_history,
7682 or the value of the environment variable
7685 history size N: The size, in commands, of the command history. The
7686 default is 256, or the value of the environment variable
7689 history save on/off: If this value is set to ON, the history file will
7690 be saved after exiting gdb. If set to OFF, the
7691 file will not be saved. The default is OFF.
7693 history expansion on/off: If this value is set to ON, then csh-like
7694 history expansion will be performed on
7695 command line input. The default is OFF.
7697 radix N: Sets the default radix for input and output. It can be set
7698 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7699 in the current radix, so "set radix 10" is always a no-op.
7701 height N: This integer value is the number of lines on a page. Default
7702 is 24, the current `stty rows'' setting, or the ``li#''
7703 setting from the termcap entry matching the environment
7706 width N: This integer value is the number of characters on a line.
7707 Default is 80, the current `stty cols'' setting, or the ``co#''
7708 setting from the termcap entry matching the environment
7711 Note: ``set screensize'' is obsolete. Use ``set height'' and
7712 ``set width'' instead.
7714 print address on/off: Print memory addresses in various command displays,
7715 such as stack traces and structure values. Gdb looks
7716 more ``symbolic'' if you turn this off; it looks more
7717 ``machine level'' with it on. Default is ON.
7719 print array on/off: Prettyprint arrays. New convenient format! Default
7722 print demangle on/off: Print C++ symbols in "source" form if on,
7725 print asm-demangle on/off: Same, for assembler level printouts
7728 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7731 * Support for Epoch Environment.
7733 The epoch environment is a version of Emacs v18 with windowing. One
7734 new command, ``inspect'', is identical to ``print'', except that if you
7735 are running in the epoch environment, the value is printed in its own
7739 * Support for Shared Libraries
7741 GDB can now debug programs and core files that use SunOS shared libraries.
7742 Symbols from a shared library cannot be referenced
7743 before the shared library has been linked with the program (this
7744 happens after you type ``run'' and before the function main() is entered).
7745 At any time after this linking (including when examining core files
7746 from dynamically linked programs), gdb reads the symbols from each
7747 shared library when you type the ``sharedlibrary'' command.
7748 It can be abbreviated ``share''.
7750 sharedlibrary REGEXP: Load shared object library symbols for files
7751 matching a unix regular expression. No argument
7752 indicates to load symbols for all shared libraries.
7754 info sharedlibrary: Status of loaded shared libraries.
7759 A watchpoint stops execution of a program whenever the value of an
7760 expression changes. Checking for this slows down execution
7761 tremendously whenever you are in the scope of the expression, but is
7762 quite useful for catching tough ``bit-spreader'' or pointer misuse
7763 problems. Some machines such as the 386 have hardware for doing this
7764 more quickly, and future versions of gdb will use this hardware.
7766 watch EXP: Set a watchpoint (breakpoint) for an expression.
7768 info watchpoints: Information about your watchpoints.
7770 delete N: Deletes watchpoint number N (same as breakpoints).
7771 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7772 enable N: Re-enables watchpoint number N (same as breakpoints).
7775 * C++ multiple inheritance
7777 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7780 * C++ exception handling
7782 Gdb now supports limited C++ exception handling. Besides the existing
7783 ability to breakpoint on an exception handler, gdb can breakpoint on
7784 the raising of an exception (before the stack is peeled back to the
7787 catch FOO: If there is a FOO exception handler in the dynamic scope,
7788 set a breakpoint to catch exceptions which may be raised there.
7789 Multiple exceptions (``catch foo bar baz'') may be caught.
7791 info catch: Lists all exceptions which may be caught in the
7792 current stack frame.
7795 * Minor command changes
7797 The command ``call func (arg, arg, ...)'' now acts like the print
7798 command, except it does not print or save a value if the function's result
7799 is void. This is similar to dbx usage.
7801 The ``up'' and ``down'' commands now always print the frame they end up
7802 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7803 frames without printing.
7805 * New directory command
7807 'dir' now adds directories to the FRONT of the source search path.
7808 The path starts off empty. Source files that contain debug information
7809 about the directory in which they were compiled can be found even
7810 with an empty path; Sun CC and GCC include this information. If GDB can't
7811 find your source file in the current directory, type "dir .".
7813 * Configuring GDB for compilation
7815 For normal use, type ``./configure host''. See README or gdb.texinfo
7818 GDB now handles cross debugging. If you are remotely debugging between
7819 two different machines, type ``./configure host -target=targ''.
7820 Host is the machine where GDB will run; targ is the machine
7821 where the program that you are debugging will run.