1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * Debugging MS-Windows processes now sets $_exitsignal when the
7 inferior is terminated by a signal, instead of setting $_exitcode.
9 * Multithreaded symbol loading has now been enabled by default on systems
10 that support it (see entry for GDB 9, below), providing faster
11 performance for programs with many symbols.
15 * 'thread-exited' event is now available in the annotations interface.
17 * New built-in convenience variables $_gdb_major and $_gdb_minor
18 provide the GDB version. They are handy for conditionally using
19 features available only in or since specific GDB versions, in
20 scripts that should work error-free with many different versions,
21 such as in system-wide init files.
23 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
24 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
25 of the GDB settings and the GDB maintenance settings. They are handy
26 for changing the logic of user defined commands depending on the
29 * GDB now supports Thread Local Storage (TLS) variables on several
30 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
31 architectures require kernel changes. TLS is not yet supported for
32 amd64 and i386 process core dumps.
34 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
35 addresses that required unmasking are shown in the backtrace with the
38 * Two new convenience functions $_cimag and $_creal that extract the
39 imaginary and real parts respectively from complex numbers.
41 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
42 provide the exitcode or exit status of the shell commands launched by
43 GDB commands such as "shell", "pipe" and "make".
45 * The command define-prefix can now define user defined prefix commands.
46 User defined commands can now be defined using these user defined prefix
49 * Command names can now use the . character.
51 * The RX port now supports XML target descriptions.
53 * GDB now shows the Ada task names at more places, e.g. in task switching
56 * GDB can now be compiled with Python 3 on Windows.
58 * New convenience variable $_ada_exception holds the address of the
59 Ada exception being thrown. This is set by Ada-related catchpoints.
61 * GDB can now place breakpoints on nested functions and subroutines in
62 Fortran code. The '::' operator can be used between parent and
63 child scopes when placing breakpoints, for example:
65 (gdb) break outer_function::inner_function
67 The 'outer_function::' prefix is only needed if 'inner_function' is
68 not visible in the current scope.
70 * In addition to the system-wide gdbinit file, if configured with
71 --with-system-gdbinit-dir, GDB will now also load files in that directory
72 as system gdbinit files, unless the -nx or -n flag is provided. Files
73 with extensions .gdb, .py and .scm are supported as long as GDB was
74 compiled with support for that language.
76 * GDB now supports multithreaded symbol loading for higher performance.
77 This feature is still in testing, so it is disabled by default. You
78 can turn it on using 'maint set worker-threads unlimited'.
80 * Multi-target debugging support
82 GDB now supports debugging multiple target connections
83 simultaneously. For example, you can now have each inferior
84 connected to different remote servers running in different machines,
85 or have one inferior debugging a local native process, an inferior
86 debugging a core dump, etc.
88 This support is experimental and comes with some limitations -- you
89 can only resume multiple targets simultaneously if all targets
90 support non-stop mode, and all remote stubs or servers must support
91 the same set of remote protocol features exactly. See also "info
92 connections" and "add-inferior -no-connection" below, and "maint set
93 target-non-stop" in the user manual.
97 ** The gdb.Value type has a new method 'format_string' which returns a
98 string representing the value. The formatting is controlled by the
99 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
100 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
101 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
103 ** gdb.Type has a new property 'objfile' which returns the objfile the
106 ** The frame information printed by the python frame filtering code
107 is now consistent with what the 'backtrace' command prints when
108 there are no filters, or when the 'backtrace' '-no-filters' option
111 ** The new function gdb.lookup_static_symbol can be used to look up
112 symbols with static linkage.
114 ** The new function gdb.lookup_static_symbols can be used to look up
115 all static symbols with static linkage.
117 ** gdb.Objfile has new methods 'lookup_global_symbol' and
118 'lookup_static_symbol' to lookup a symbol from this objfile only.
120 ** gdb.Block now supports the dictionary syntax for accessing symbols in
121 this block (e.g. block['local_variable']).
125 | [COMMAND] | SHELL_COMMAND
126 | -d DELIM COMMAND DELIM SHELL_COMMAND
127 pipe [COMMAND] | SHELL_COMMAND
128 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
129 Executes COMMAND and sends its output to SHELL_COMMAND.
130 With no COMMAND, repeat the last executed command
131 and send its output to SHELL_COMMAND.
133 define-prefix COMMAND
134 Define or mark a command as a user-defined prefix command.
136 with SETTING [VALUE] [-- COMMAND]
137 w SETTING [VALUE] [-- COMMAND]
138 Temporarily set SETTING, run COMMAND, and restore SETTING.
139 Usage: with SETTING -- COMMAND
140 With no COMMAND, repeats the last executed command.
141 SETTING is any GDB setting you can change with the "set"
142 subcommands. For example, 'with language c -- print someobj'
143 temporarily switches to the C language in order to print someobj.
144 Settings can be combined: 'w lang c -- w print elements unlimited --
145 usercmd' switches to the C language and runs usercmd with no limit
146 of array elements to print.
148 maint with SETTING [VALUE] [-- COMMAND]
149 Like "with", but works with "maintenance set" settings.
151 set may-call-functions [on|off]
152 show may-call-functions
153 This controls whether GDB will attempt to call functions in
154 the program, such as with expressions in the print command. It
155 defaults to on. Calling functions in the program being debugged
156 can have undesired side effects. It is now possible to forbid
157 such function calls. If function calls are forbidden, GDB will throw
158 an error when a command (such as print expression) calls a function
161 set print finish [on|off]
163 This controls whether the `finish' command will display the value
164 that is returned by the current function. When `off', the value is
165 still entered into the value history, but it is not printed. The
170 Allows deeply nested structures to be simplified when printing by
171 replacing deeply nested parts (beyond the max-depth) with ellipses.
172 The default max-depth is 20, but this can be set to unlimited to get
173 the old behavior back.
175 set print raw-values [on|off]
176 show print raw-values
177 By default, GDB applies the enabled pretty printers when printing a
178 value. This allows to ignore the enabled pretty printers for a series
179 of commands. The default is 'off'.
181 set logging debugredirect [on|off]
182 By default, GDB debug output will go to both the terminal and the logfile.
183 Set if you want debug output to go only to the log file.
185 set style title foreground COLOR
186 set style title background COLOR
187 set style title intensity VALUE
188 Control the styling of titles.
190 set style highlight foreground COLOR
191 set style highlight background COLOR
192 set style highlight intensity VALUE
193 Control the styling of highlightings.
195 maint set worker-threads
196 maint show worker-threads
197 Control the number of worker threads that can be used by GDB. The
198 default is 0. "unlimited" lets GDB choose a number that is
199 reasonable. Currently worker threads are only used when demangling
200 the names of linker symbols.
202 set style tui-border foreground COLOR
203 set style tui-border background COLOR
204 Control the styling of TUI borders.
206 set style tui-active-border foreground COLOR
207 set style tui-active-border background COLOR
208 Control the styling of the active TUI border.
210 maint set test-settings KIND
211 maint show test-settings KIND
212 A set of commands used by the testsuite for exercising the settings
215 maint set tui-resize-message [on|off]
216 maint show tui-resize-message
217 Control whether GDB prints a message each time the terminal is
218 resized when in TUI mode. This is primarily useful for testing the
221 set print frame-info [short-location|location|location-and-address
222 |source-and-location|source-line|auto]
223 show print frame-info
224 This controls what frame information is printed by the commands printing
225 a frame. This setting will e.g. influence the behaviour of 'backtrace',
226 'frame', 'stepi'. The python frame filtering also respect this setting.
227 The 'backtrace' '-frame-info' option can override this global setting.
229 set tui compact-source
230 show tui compact-source
232 Enable the "compact" display mode for the TUI source window. The
233 compact display uses only as much space as is needed for the line
234 numbers in the current file, and only a single space to separate the
235 line numbers from the source.
237 info modules [-q] [REGEXP]
238 Return a list of Fortran modules matching REGEXP, or all modules if
241 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
242 Return a list of functions within all modules, grouped by module.
243 The list of functions can be restricted with the optional regular
244 expressions. MODULE_REGEXP matches against the module name,
245 TYPE_REGEXP matches against the function type signature, and REGEXP
246 matches against the function name.
248 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
249 Return a list of variables within all modules, grouped by module.
250 The list of variables can be restricted with the optional regular
251 expressions. MODULE_REGEXP matches against the module name,
252 TYPE_REGEXP matches against the variable type, and REGEXP matches
253 against the variable name.
255 set debug remote-packet-max-chars
256 show debug remote-packet-max-chars
257 Controls the number of characters to output in a remote packet when using
259 The default is 512 bytes.
262 Lists the target connections currently in use.
267 The "help" command uses the title style to enhance the
268 readibility of its output by styling the classes and
272 Similarly to "help", the "apropos" command also uses the
273 title style for the command names. "apropos" accepts now
274 a flag "-v" (verbose) to show the full documentation
275 of matching commands and to use the highlight style to mark
276 the documentation parts matching REGEXP.
280 The GDB printf and eval commands can now print C-style and Ada-style
281 string convenience variables without calling functions in the program.
282 This allows to do formatted printing of strings without having
283 a running inferior, or when debugging a core dump.
285 info sources [-dirname | -basename] [--] [REGEXP]
286 This command has now optional arguments to only print the files
287 whose names match REGEXP. The arguments -dirname and -basename
288 allow to restrict matching respectively to the dirname and basename
292 The "show style" and its subcommands are now styling
293 a style name in their output using its own style, to help
294 the user visualize the different styles.
296 set print frame-arguments
297 The new value 'presence' indicates to only indicate the presence of
298 arguments using ..., instead of printing argument names and values.
300 set print raw-frame-arguments
301 show print raw-frame-arguments
303 These commands replace the similarly-named "set/show print raw
304 frame-arguments" commands (now with a dash instead of a space). The
305 old commands are now deprecated and may be removed in a future
308 add-inferior [-no-connection]
309 The add-inferior command now supports a "-no-connection" flag that
310 makes the new inferior start with no target connection associated.
311 By default, the new inferior inherits the target connection of the
312 current inferior. See also "info connections".
315 This command's output now includes a new "Connection" column
316 indicating which target connection an inferior is bound to. See
317 "info connections" above.
319 maint test-options require-delimiter
320 maint test-options unknown-is-error
321 maint test-options unknown-is-operand
322 maint show test-options-completion-result
323 Commands used by the testsuite to validate the command options
326 focus, winheight, +, -, >, <
327 These commands are now case-sensitive.
329 * New command options, command completion
331 GDB now has a standard infrastructure to support dash-style command
332 options ('-OPT'). One benefit is that commands that use it can
333 easily support completion of command line arguments. Try "CMD
334 -[TAB]" or "help CMD" to find options supported by a command. Over
335 time, we intend to migrate most commands to this infrastructure. A
336 number of commands got support for new command options in this
339 ** The "print" and "compile print" commands now support a number of
340 options that allow overriding relevant global print settings as
341 set by "set print" subcommands:
345 -array-indexes [on|off]
346 -elements NUMBER|unlimited
351 -repeats NUMBER|unlimited
352 -static-members [on|off]
357 Note that because the "print"/"compile print" commands accept
358 arbitrary expressions which may look like options (including
359 abbreviations), if you specify any command option, then you must
360 use a double dash ("--") to mark the end of argument processing.
362 ** The "backtrace" command now supports a number of options that
363 allow overriding relevant global print settings as set by "set
364 backtrace" and "set print" subcommands:
366 -entry-values no|only|preferred|if-needed|both|compact|default
367 -frame-arguments all|scalars|none
368 -raw-frame-arguments [on|off]
369 -frame-info auto|source-line|location|source-and-location
370 |location-and-address|short-location
374 In addition, the full/no-filters/hide qualifiers are now also
375 exposed as command options too:
381 ** The "frame apply", "tfaas" and "faas" commands similarly now
382 support the following options:
387 ** The new "info sources" options -dirname and -basename options
388 are using the standard '-OPT' infrastructure.
390 All options above can also be abbreviated. The argument of boolean
391 (on/off) options can be 0/1 too, and also the argument is assumed
392 "on" if omitted. This allows writing compact command invocations,
395 (gdb) p -ra -p -o 0 -- *myptr
397 The above is equivalent to:
399 (gdb) print -raw-values -pretty -object off -- *myptr
401 ** The "info types" command now supports the '-q' flag to disable
402 printing of some header information in a similar fashion to "info
403 variables" and "info functions".
405 ** The "info variables", "info functions", and "whereis" commands
406 now take a '-n' flag that excludes non-debug symbols (symbols
407 from the symbol table, not from the debug info such as DWARF)
410 * Completion improvements
412 ** GDB can now complete the options of the "thread apply all" and
413 "taas" commands, and their "-ascending" option can now be
416 ** GDB can now complete the options of the "info threads", "info
417 functions", "info variables", "info locals", and "info args"
420 ** GDB can now complete the options of the "compile file" and
421 "compile code" commands. The "compile file" command now
422 completes on filenames.
424 ** GDB can now complete the backtrace command's
425 "full/no-filters/hide" qualifiers.
427 * In settings, you can now abbreviate "unlimited".
429 E.g., "set print elements u" is now equivalent to "set print
435 This lists all the possible completions for the rest of the line, if it
436 were to be given as a command itself. This is intended for use by MI
437 frontends in cases when separate CLI and MI channels cannot be used.
439 -catch-throw, -catch-rethrow, and -catch-catch
440 These can be used to catch C++ exceptions in a similar fashion to
441 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
443 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
444 These commands are the MI equivalent of the CLI commands 'info
445 functions', 'info types', and 'info variables' respectively.
447 -symbol-info-modules, this is the MI equivalent of the CLI 'info
450 -symbol-info-module-functions and -symbol-info-module-variables.
451 These commands are the MI equivalent of the CLI commands 'info
452 module functions' and 'info module variables'.
456 ** The default version of the MI interpreter is now 3 (-i=mi3).
458 ** The output of information about multi-location breakpoints (which is
459 syntactically incorrect in MI 2) has changed in MI 3. This affects
460 the following commands and events:
464 - =breakpoint-created
465 - =breakpoint-modified
467 The -fix-multi-location-breakpoint-output command can be used to enable
468 this behavior with previous MI versions.
470 ** Backtraces and frames include a new optional field addr_flags which is
471 given after the addr field. On AArch64 this contains PAC if the address
472 has been masked in the frame. On all other targets the field is not
477 The testsuite now creates the files gdb.cmd (containing the arguments
478 used to launch GDB) and gdb.in (containing all the commands sent to
479 GDB) in the output directory for each test script. Multiple invocations
480 are appended with .1, .2, .3 etc.
482 * Building GDB and GDBserver now requires GNU make >= 3.82.
484 Using another implementation of the make program or an earlier version of
485 GNU make to build GDB or GDBserver is not supported.
487 * Building GDB now requires GNU readline >= 7.0.
489 GDB now bundles GNU readline 8.0, but if you choose to use
490 --with-system-readline, only readline >= 7.0 can be used.
492 * The TUI SingleKey keymap is now named "SingleKey". This can be used
493 from .inputrc to bind keys in this keymap. This feature is only
494 available when gdb is built against GNU readline 8.0 or later.
496 * Removed targets and native configurations
498 GDB no longer supports debugging the Cell Broadband Engine. This includes
499 both debugging standalone Cell/B.E. SPU applications and integrated debugging
500 of Cell/B.E. applications that use both the PPU and SPU architectures.
506 * Removed targets and native configurations
508 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
511 *** Changes in GDB 8.3
513 * GDB and GDBserver now support access to additional registers on
514 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
517 * GDB now has experimental support for the compilation and injection of
518 C++ source code into the inferior. This beta release does not include
519 support for several language features, such as templates, constructors,
522 This feature requires GCC 7.1 or higher built with libcp1.so
525 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
526 can be passed using the '[ADDRESS]:PORT' notation, or the regular
527 'ADDRESS:PORT' method.
529 * DWARF index cache: GDB can now automatically save indices of DWARF
530 symbols on disk to speed up further loading of the same binaries.
532 * Ada task switching is now supported on aarch64-elf targets when
533 debugging a program using the Ravenscar Profile. For more information,
534 see the "Tasking Support when using the Ravenscar Profile" section
535 in the GDB user manual.
537 * GDB in batch mode now exits with status 1 if the last command to be
540 * The RISC-V target now supports target descriptions.
542 * System call catchpoints now support system call aliases on FreeBSD.
543 When the ABI of a system call changes in FreeBSD, this is
544 implemented by leaving a compatibility system call using the old ABI
545 at the existing number and allocating a new system call number for
546 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
547 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
548 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
549 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
550 so that a system call catchpoint for the 'kevent' system call will
551 catch invocations of both the 'kevent' and 'freebsd11_kevent'
552 binaries. This ensures that 'kevent' system calls are caught for
553 binaries using either the old or new ABIs.
555 * Terminal styling is now available for the CLI and the TUI. GNU
556 Source Highlight can additionally be used to provide styling of
557 source code snippets. See the "set style" commands, below, for more
560 * Removed support for old demangling styles arm, edg, gnu, hp and
565 set debug compile-cplus-types
566 show debug compile-cplus-types
567 Control the display of debug output about type conversion in the
568 C++ compile feature. Commands have no effect while compiliong
573 Control whether debug output about files/functions skipping is
576 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
577 Apply a command to some frames.
578 FLAG arguments allow to control what output to produce and how to handle
579 errors raised when applying COMMAND to a frame.
582 Apply a command to all threads (ignoring errors and empty output).
583 Shortcut for 'thread apply all -s COMMAND'.
586 Apply a command to all frames (ignoring errors and empty output).
587 Shortcut for 'frame apply all -s COMMAND'.
590 Apply a command to all frames of all threads (ignoring errors and empty
592 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
594 maint set dwarf unwinders (on|off)
595 maint show dwarf unwinders
596 Control whether DWARF unwinders can be used.
599 Display a list of open files for a process.
603 Changes to the "frame", "select-frame", and "info frame" CLI commands.
604 These commands all now take a frame specification which
605 is either a frame level, or one of the keywords 'level', 'address',
606 'function', or 'view' followed by a parameter. Selecting a frame by
607 address, or viewing a frame outside the current backtrace now
608 requires the use of a keyword. Selecting a frame by level is
609 unchanged. The MI comment "-stack-select-frame" is unchanged.
611 target remote FILENAME
612 target extended-remote FILENAME
613 If FILENAME is a Unix domain socket, GDB will attempt to connect
614 to this socket instead of opening FILENAME as a character device.
616 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
617 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
618 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
619 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
620 These commands can now print only the searched entities
621 matching the provided regexp(s), giving a condition
622 on the entity names or entity types. The flag -q disables
623 printing headers or informations messages.
629 These commands now determine the syntax for the shown entities
630 according to the language chosen by `set language'. In particular,
631 `set language auto' means to automatically choose the language of
634 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
635 The 'thread apply' command accepts new FLAG arguments.
636 FLAG arguments allow to control what output to produce and how to handle
637 errors raised when applying COMMAND to a thread.
639 set tui tab-width NCHARS
640 show tui tab-width NCHARS
641 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
643 set style enabled [on|off]
645 Enable or disable terminal styling. Styling is enabled by default
646 on most hosts, but disabled by default when in batch mode.
648 set style sources [on|off]
650 Enable or disable source code styling. Source code styling is
651 enabled by default, but only takes effect if styling in general is
652 enabled, and if GDB was linked with GNU Source Highlight.
654 set style filename foreground COLOR
655 set style filename background COLOR
656 set style filename intensity VALUE
657 Control the styling of file names.
659 set style function foreground COLOR
660 set style function background COLOR
661 set style function intensity VALUE
662 Control the styling of function names.
664 set style variable foreground COLOR
665 set style variable background COLOR
666 set style variable intensity VALUE
667 Control the styling of variable names.
669 set style address foreground COLOR
670 set style address background COLOR
671 set style address intensity VALUE
672 Control the styling of addresses.
676 ** The '-data-disassemble' MI command now accepts an '-a' option to
677 disassemble the whole function surrounding the given program
678 counter value or function name. Support for this feature can be
679 verified by using the "-list-features" command, which should
680 contain "data-disassemble-a-option".
682 ** Command responses and notifications that include a frame now include
683 the frame's architecture in a new "arch" attribute.
685 * New native configurations
687 GNU/Linux/RISC-V riscv*-*-linux*
688 FreeBSD/riscv riscv*-*-freebsd*
692 GNU/Linux/RISC-V riscv*-*-linux*
694 CSKY GNU/LINUX csky*-*-linux
695 FreeBSD/riscv riscv*-*-freebsd*
697 GNU/Linux/OpenRISC or1k*-*-linux*
701 GDB no longer supports native debugging on versions of MS-Windows
706 ** GDB no longer supports Python versions less than 2.6.
708 ** The gdb.Inferior type has a new 'progspace' property, which is the program
709 space associated to that inferior.
711 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
712 of objfiles associated to that program space.
714 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
715 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
718 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
719 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
720 correct and did not work properly.
722 ** The gdb.Value type has a new constructor, which is used to construct a
723 gdb.Value from a Python buffer object and a gdb.Type.
729 Enable or disable the undefined behavior sanitizer. This is
730 disabled by default, but passing --enable-ubsan=yes or
731 --enable-ubsan=auto to configure will enable it. Enabling this can
732 cause a performance penalty. The undefined behavior sanitizer was
733 first introduced in GCC 4.9.
735 *** Changes in GDB 8.2
737 * The 'set disassembler-options' command now supports specifying options
740 * The 'symbol-file' command now accepts an '-o' option to add a relative
741 offset to all sections.
743 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
744 a relative offset to all sections, but it allows to override the load
745 address of individual sections using '-s'.
747 * The 'add-symbol-file' command no longer requires the second argument
748 (address of the text section).
750 * The endianness used with the 'set endian auto' mode in the absence of
751 an executable selected for debugging is now the last endianness chosen
752 either by one of the 'set endian big' and 'set endian little' commands
753 or by inferring from the last executable used, rather than the startup
756 * The pager now allows a "c" response, meaning to disable the pager
757 for the rest of the current command.
759 * The commands 'info variables/functions/types' now show the source line
760 numbers of symbol definitions when available.
762 * 'info proc' now works on running processes on FreeBSD systems and core
763 files created on FreeBSD systems.
765 * C expressions can now use _Alignof, and C++ expressions can now use
768 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
769 the vector length while the process is running.
775 Control display of debugging info regarding the FreeBSD native target.
777 set|show varsize-limit
778 This new setting allows the user to control the maximum size of Ada
779 objects being printed when those objects have a variable type,
780 instead of that maximum size being hardcoded to 65536 bytes.
782 set|show record btrace cpu
783 Controls the processor to be used for enabling errata workarounds for
786 maint check libthread-db
787 Run integrity checks on the current inferior's thread debugging
790 maint set check-libthread-db (on|off)
791 maint show check-libthread-db
792 Control whether to run integrity checks on inferior specific thread
793 debugging libraries as they are loaded. The default is not to
798 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
800 ** The commands attached to a breakpoint can be set by assigning to
801 the breakpoint's "commands" field.
803 ** gdb.execute can now execute multi-line gdb commands.
805 ** The new functions gdb.convenience_variable and
806 gdb.set_convenience_variable can be used to get and set the value
807 of convenience variables.
809 ** A gdb.Parameter will no longer print the "set" help text on an
810 ordinary "set"; instead by default a "set" will be silent unless
811 the get_set_string method returns a non-empty string.
815 RiscV ELF riscv*-*-elf
817 * Removed targets and native configurations
819 m88k running OpenBSD m88*-*-openbsd*
820 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
821 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
822 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
824 * Aarch64/Linux hardware watchpoints improvements
826 Hardware watchpoints on unaligned addresses are now properly
827 supported when running Linux kernel 4.10 or higher: read and access
828 watchpoints are no longer spuriously missed, and all watchpoints
829 lengths between 1 and 8 bytes are supported. On older kernels,
830 watchpoints set on unaligned addresses are no longer missed, with
831 the tradeoff that there is a possibility of false hits being
836 --enable-codesign=CERT
837 This can be used to invoke "codesign -s CERT" after building gdb.
838 This option is useful on macOS, where code signing is required for
839 gdb to work properly.
841 --disable-gdbcli has been removed
842 This is now silently accepted, but does nothing.
844 *** Changes in GDB 8.1
846 * GDB now supports dynamically creating arbitrary register groups specified
847 in XML target descriptions. This allows for finer grain grouping of
848 registers on systems with a large amount of registers.
850 * The 'ptype' command now accepts a '/o' flag, which prints the
851 offsets and sizes of fields in a struct, like the pahole(1) tool.
853 * New "--readnever" command line option instructs GDB to not read each
854 symbol file's symbolic debug information. This makes startup faster
855 but at the expense of not being able to perform symbolic debugging.
856 This option is intended for use cases where symbolic debugging will
857 not be used, e.g., when you only need to dump the debuggee's core.
859 * GDB now uses the GNU MPFR library, if available, to emulate target
860 floating-point arithmetic during expression evaluation when the target
861 uses different floating-point formats than the host. At least version
862 3.1 of GNU MPFR is required.
864 * GDB now supports access to the guarded-storage-control registers and the
865 software-based guarded-storage broadcast control registers on IBM z14.
867 * On Unix systems, GDB now supports transmitting environment variables
868 that are to be set or unset to GDBserver. These variables will
869 affect the environment to be passed to the remote inferior.
871 To inform GDB of environment variables that are to be transmitted to
872 GDBserver, use the "set environment" command. Only user set
873 environment variables are sent to GDBserver.
875 To inform GDB of environment variables that are to be unset before
876 the remote inferior is started by the GDBserver, use the "unset
877 environment" command.
879 * Completion improvements
881 ** GDB can now complete function parameters in linespecs and
882 explicit locations without quoting. When setting breakpoints,
883 quoting around functions names to help with TAB-completion is
884 generally no longer necessary. For example, this now completes
887 (gdb) b function(in[TAB]
888 (gdb) b function(int)
890 Related, GDB is no longer confused with completing functions in
891 C++ anonymous namespaces:
894 (gdb) b (anonymous namespace)::[TAB][TAB]
895 (anonymous namespace)::a_function()
896 (anonymous namespace)::b_function()
898 ** GDB now has much improved linespec and explicit locations TAB
899 completion support, that better understands what you're
900 completing and offers better suggestions. For example, GDB no
901 longer offers data symbols as possible completions when you're
902 setting a breakpoint.
904 ** GDB now TAB-completes label symbol names.
906 ** The "complete" command now mimics TAB completion accurately.
908 * New command line options (gcore)
911 Dump all memory mappings.
913 * Breakpoints on C++ functions are now set on all scopes by default
915 By default, breakpoints on functions/methods are now interpreted as
916 specifying all functions with the given name ignoring missing
917 leading scopes (namespaces and classes).
919 For example, assuming a C++ program with symbols named:
924 both commands "break func()" and "break B::func()" set a breakpoint
927 You can use the new flag "-qualified" to override this. This makes
928 GDB interpret the specified function name as a complete
929 fully-qualified name instead. For example, using the same C++
930 program, the "break -q B::func" command sets a breakpoint on
931 "B::func", only. A parameter has been added to the Python
932 gdb.Breakpoint constructor to achieve the same result when creating
933 a breakpoint from Python.
935 * Breakpoints on functions marked with C++ ABI tags
937 GDB can now set breakpoints on functions marked with C++ ABI tags
938 (e.g., [abi:cxx11]). See here for a description of ABI tags:
939 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
941 Functions with a C++11 abi tag are demangled/displayed like this:
943 function[abi:cxx11](int)
946 You can now set a breakpoint on such functions simply as if they had
949 (gdb) b function(int)
951 Or if you need to disambiguate between tags, like:
953 (gdb) b function[abi:other_tag](int)
955 Tab completion was adjusted accordingly as well.
959 ** New events gdb.new_inferior, gdb.inferior_deleted, and
960 gdb.new_thread are emitted. See the manual for further
961 description of these.
963 ** A new function, "gdb.rbreak" has been added to the Python API.
964 This function allows the setting of a large number of breakpoints
965 via a regex pattern in Python. See the manual for further details.
967 ** Python breakpoints can now accept explicit locations. See the
968 manual for a further description of this feature.
971 * New features in the GDB remote stub, GDBserver
973 ** GDBserver is now able to start inferior processes with a
974 specified initial working directory.
976 The user can set the desired working directory to be used from
977 GDB using the new "set cwd" command.
979 ** New "--selftest" command line option runs some GDBserver self
980 tests. These self tests are disabled in releases.
982 ** On Unix systems, GDBserver now does globbing expansion and variable
983 substitution in inferior command line arguments.
985 This is done by starting inferiors using a shell, like GDB does.
986 See "set startup-with-shell" in the user manual for how to disable
987 this from GDB when using "target extended-remote". When using
988 "target remote", you can disable the startup with shell by using the
989 new "--no-startup-with-shell" GDBserver command line option.
991 ** On Unix systems, GDBserver now supports receiving environment
992 variables that are to be set or unset from GDB. These variables
993 will affect the environment to be passed to the inferior.
995 * When catching an Ada exception raised with a message, GDB now prints
996 the message in the catchpoint hit notification. In GDB/MI mode, that
997 information is provided as an extra field named "exception-message"
998 in the *stopped notification.
1000 * Trait objects can now be inspected When debugging Rust code. This
1001 requires compiler support which will appear in Rust 1.24.
1003 * New remote packets
1005 QEnvironmentHexEncoded
1006 Inform GDBserver of an environment variable that is to be passed to
1007 the inferior when starting it.
1010 Inform GDBserver of an environment variable that is to be unset
1011 before starting the remote inferior.
1014 Inform GDBserver that the environment should be reset (i.e.,
1015 user-set environment variables should be unset).
1018 Indicates whether the inferior must be started with a shell or not.
1021 Tell GDBserver that the inferior to be started should use a specific
1024 * The "maintenance print c-tdesc" command now takes an optional
1025 argument which is the file name of XML target description.
1027 * The "maintenance selftest" command now takes an optional argument to
1028 filter the tests to be run.
1030 * The "enable", and "disable" commands now accept a range of
1031 breakpoint locations, e.g. "enable 1.3-5".
1036 Set and show the current working directory for the inferior.
1038 set|show compile-gcc
1039 Set and show compilation command used for compiling and injecting code
1040 with the 'compile' commands.
1042 set debug separate-debug-file
1043 show debug separate-debug-file
1044 Control the display of debug output about separate debug file search.
1046 set dump-excluded-mappings
1047 show dump-excluded-mappings
1048 Control whether mappings marked with the VM_DONTDUMP flag should be
1049 dumped when generating a core file.
1051 maint info selftests
1052 List the registered selftests.
1055 Start the debugged program stopping at the first instruction.
1058 Control display of debugging messages related to OpenRISC targets.
1060 set|show print type nested-type-limit
1061 Set and show the limit of nesting level for nested types that the
1062 type printer will show.
1064 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1067 * Safer/improved support for debugging with no debug info
1069 GDB no longer assumes functions with no debug information return
1072 This means that GDB now refuses to call such functions unless you
1073 tell it the function's type, by either casting the call to the
1074 declared return type, or by casting the function to a function
1075 pointer of the right type, and calling that:
1077 (gdb) p getenv ("PATH")
1078 'getenv' has unknown return type; cast the call to its declared return type
1079 (gdb) p (char *) getenv ("PATH")
1080 $1 = 0x7fffffffe "/usr/local/bin:/"...
1081 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1082 $2 = 0x7fffffffe "/usr/local/bin:/"...
1084 Similarly, GDB no longer assumes that global variables with no debug
1085 info have type 'int', and refuses to print the variable's value
1086 unless you tell it the variable's type:
1089 'var' has unknown type; cast it to its declared type
1093 * New native configurations
1095 FreeBSD/aarch64 aarch64*-*-freebsd*
1096 FreeBSD/arm arm*-*-freebsd*
1100 FreeBSD/aarch64 aarch64*-*-freebsd*
1101 FreeBSD/arm arm*-*-freebsd*
1102 OpenRISC ELF or1k*-*-elf
1104 * Removed targets and native configurations
1106 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1108 *** Changes in GDB 8.0
1110 * GDB now supports access to the PKU register on GNU/Linux. The register is
1111 added by the Memory Protection Keys for Userspace feature which will be
1112 available in future Intel CPUs.
1114 * GDB now supports C++11 rvalue references.
1118 ** New functions to start, stop and access a running btrace recording.
1119 ** Rvalue references are now supported in gdb.Type.
1121 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1124 * Building GDB and GDBserver now requires a C++11 compiler.
1126 For example, GCC 4.8 or later.
1128 It is no longer possible to build GDB or GDBserver with a C
1129 compiler. The --disable-build-with-cxx configure option has been
1132 * Building GDB and GDBserver now requires GNU make >= 3.81.
1134 It is no longer supported to build GDB or GDBserver with another
1135 implementation of the make program or an earlier version of GNU make.
1137 * Native debugging on MS-Windows supports command-line redirection
1139 Command-line arguments used for starting programs on MS-Windows can
1140 now include redirection symbols supported by native Windows shells,
1141 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1142 as "run", "start", and "set args", as well as the corresponding MI
1145 * Support for thread names on MS-Windows.
1147 GDB now catches and handles the special exception that programs
1148 running on MS-Windows use to assign names to threads in the
1151 * Support for Java programs compiled with gcj has been removed.
1153 * User commands now accept an unlimited number of arguments.
1154 Previously, only up to 10 was accepted.
1156 * The "eval" command now expands user-defined command arguments.
1158 This makes it easier to process a variable number of arguments:
1163 eval "print $arg%d", $i
1168 * Target descriptions can now describe registers for sparc32 and sparc64.
1170 * GDB now supports DWARF version 5 (debug information format).
1171 Its .debug_names index is not yet supported.
1173 * New native configurations
1175 FreeBSD/mips mips*-*-freebsd
1179 Synopsys ARC arc*-*-elf32
1180 FreeBSD/mips mips*-*-freebsd
1182 * Removed targets and native configurations
1184 Alpha running FreeBSD alpha*-*-freebsd*
1185 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1190 Erases all the flash memory regions reported by the target.
1192 maint print arc arc-instruction address
1193 Print internal disassembler information about instruction at a given address.
1197 set disassembler-options
1198 show disassembler-options
1199 Controls the passing of target specific information to the disassembler.
1200 If it is necessary to specify more than one disassembler option then
1201 multiple options can be placed together into a comma separated list.
1202 The default value is the empty string. Currently, the only supported
1203 targets are ARM, PowerPC and S/390.
1208 Erases all the flash memory regions reported by the target. This is
1209 equivalent to the CLI command flash-erase.
1211 -file-list-shared-libraries
1212 List the shared libraries in the program. This is
1213 equivalent to the CLI command "info shared".
1216 Catchpoints stopping the program when Ada exceptions are
1217 handled. This is equivalent to the CLI command "catch handlers".
1219 *** Changes in GDB 7.12
1221 * GDB and GDBserver now build with a C++ compiler by default.
1223 The --enable-build-with-cxx configure option is now enabled by
1224 default. One must now explicitly configure with
1225 --disable-build-with-cxx in order to build with a C compiler. This
1226 option will be removed in a future release.
1228 * GDBserver now supports recording btrace without maintaining an active
1231 * GDB now supports a negative repeat count in the 'x' command to examine
1232 memory backward from the given address. For example:
1235 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1236 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1237 (gdb) x/-5i 0x0000000000400580
1238 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1239 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1240 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1241 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1242 0x40057b <main(int, char**)+25>:
1243 callq 0x400536 <Func1(int, char const*)>
1245 * Fortran: Support structures with fields of dynamic types and
1246 arrays of dynamic types.
1248 * The symbol dumping maintenance commands have new syntax.
1249 maint print symbols [-pc address] [--] [filename]
1250 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1251 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1252 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1253 maint print msymbols [-objfile objfile] [--] [filename]
1255 * GDB now supports multibit bitfields and enums in target register
1258 * New Python-based convenience function $_as_string(val), which returns
1259 the textual representation of a value. This function is especially
1260 useful to obtain the text label of an enum value.
1262 * Intel MPX bound violation handling.
1264 Segmentation faults caused by a Intel MPX boundary violation
1265 now display the kind of violation (upper or lower), the memory
1266 address accessed and the memory bounds, along with the usual
1267 signal received and code location.
1271 Program received signal SIGSEGV, Segmentation fault
1272 Upper bound violation while accessing address 0x7fffffffc3b3
1273 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1274 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1276 * Rust language support.
1277 GDB now supports debugging programs written in the Rust programming
1278 language. See https://www.rust-lang.org/ for more information about
1281 * Support for running interpreters on specified input/output devices
1283 GDB now supports a new mechanism that allows frontends to provide
1284 fully featured GDB console views, as a better alternative to
1285 building such views on top of the "-interpreter-exec console"
1286 command. See the new "new-ui" command below. With that command,
1287 frontends can now start GDB in the traditional command-line mode
1288 running in an embedded terminal emulator widget, and create a
1289 separate MI interpreter running on a specified i/o device. In this
1290 way, GDB handles line editing, history, tab completion, etc. in the
1291 console all by itself, and the GUI uses the separate MI interpreter
1292 for its own control and synchronization, invisible to the command
1295 * The "catch syscall" command catches groups of related syscalls.
1297 The "catch syscall" command now supports catching a group of related
1298 syscalls using the 'group:' or 'g:' prefix.
1303 skip -gfile file-glob-pattern
1304 skip -function function
1305 skip -rfunction regular-expression
1306 A generalized form of the skip command, with new support for
1307 glob-style file names and regular expressions for function names.
1308 Additionally, a file spec and a function spec may now be combined.
1310 maint info line-table REGEXP
1311 Display the contents of GDB's internal line table data struture.
1314 Run any GDB unit tests that were compiled in.
1317 Start a new user interface instance running INTERP as interpreter,
1318 using the TTY file for input/output.
1322 ** gdb.Breakpoint objects have a new attribute "pending", which
1323 indicates whether the breakpoint is pending.
1324 ** Three new breakpoint-related events have been added:
1325 gdb.breakpoint_created, gdb.breakpoint_modified, and
1326 gdb.breakpoint_deleted.
1328 signal-event EVENTID
1329 Signal ("set") the given MS-Windows event object. This is used in
1330 conjunction with the Windows JIT debugging (AeDebug) support, where
1331 the OS suspends a crashing process until a debugger can attach to
1332 it. Resuming the crashing process, in order to debug it, is done by
1333 signalling an event.
1335 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1336 was added in GDBserver, including JIT compiling fast tracepoint's
1337 conditional expression bytecode into native code.
1339 * Support for various remote target protocols and ROM monitors has
1342 target m32rsdi Remote M32R debugging over SDI
1343 target mips MIPS remote debugging protocol
1344 target pmon PMON ROM monitor
1345 target ddb NEC's DDB variant of PMON for Vr4300
1346 target rockhopper NEC RockHopper variant of PMON
1347 target lsi LSI variant of PMO
1349 * Support for tracepoints and fast tracepoints on powerpc-linux,
1350 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1351 including JIT compiling fast tracepoint's conditional expression
1352 bytecode into native code.
1354 * MI async record =record-started now includes the method and format used for
1355 recording. For example:
1357 =record-started,thread-group="i1",method="btrace",format="bts"
1359 * MI async record =thread-selected now includes the frame field. For example:
1361 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1365 Andes NDS32 nds32*-*-elf
1367 *** Changes in GDB 7.11
1369 * GDB now supports debugging kernel-based threads on FreeBSD.
1371 * Per-inferior thread numbers
1373 Thread numbers are now per inferior instead of global. If you're
1374 debugging multiple inferiors, GDB displays thread IDs using a
1375 qualified INF_NUM.THR_NUM form. For example:
1379 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1380 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1381 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1382 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1384 As consequence, thread numbers as visible in the $_thread
1385 convenience variable and in Python's InferiorThread.num attribute
1386 are no longer unique between inferiors.
1388 GDB now maintains a second thread ID per thread, referred to as the
1389 global thread ID, which is the new equivalent of thread numbers in
1390 previous releases. See also $_gthread below.
1392 For backwards compatibility, MI's thread IDs always refer to global
1395 * Commands that accept thread IDs now accept the qualified
1396 INF_NUM.THR_NUM form as well. For example:
1399 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1402 * In commands that accept a list of thread IDs, you can now refer to
1403 all threads of an inferior using a star wildcard. GDB accepts
1404 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1405 refer to all threads of the current inferior. For example, "info
1408 * You can use "info threads -gid" to display the global thread ID of
1411 * The new convenience variable $_gthread holds the global number of
1414 * The new convenience variable $_inferior holds the number of the
1417 * GDB now displays the ID and name of the thread that hit a breakpoint
1418 or received a signal, if your program is multi-threaded. For
1421 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1422 Thread 1 "main" received signal SIGINT, Interrupt.
1424 * Record btrace now supports non-stop mode.
1426 * Support for tracepoints on aarch64-linux was added in GDBserver.
1428 * The 'record instruction-history' command now indicates speculative execution
1429 when using the Intel Processor Trace recording format.
1431 * GDB now allows users to specify explicit locations, bypassing
1432 the linespec parser. This feature is also available to GDB/MI
1435 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1436 GDB now is able to debug both AArch64 applications and ARM applications
1439 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1440 including JIT compiling fast tracepoint's conditional expression bytecode
1443 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1445 * "info threads", "info inferiors", "info display", "info checkpoints"
1446 and "maint info program-spaces" now list the corresponding items in
1447 ascending ID order, for consistency with all other "info" commands.
1449 * In Ada, the overloads selection menu has been enhanced to display the
1450 parameter types and the return types for the matching overloaded subprograms.
1454 maint set target-non-stop (on|off|auto)
1455 maint show target-non-stop
1456 Control whether GDB targets always operate in non-stop mode even if
1457 "set non-stop" is "off". The default is "auto", meaning non-stop
1458 mode is enabled if supported by the target.
1460 maint set bfd-sharing
1461 maint show bfd-sharing
1462 Control the reuse of bfd objects.
1465 show debug bfd-cache
1466 Control display of debugging info regarding bfd caching.
1470 Control display of debugging info regarding FreeBSD threads.
1472 set remote multiprocess-extensions-packet
1473 show remote multiprocess-extensions-packet
1474 Set/show the use of the remote protocol multiprocess extensions.
1476 set remote thread-events
1477 show remote thread-events
1478 Set/show the use of thread create/exit events.
1480 set ada print-signatures on|off
1481 show ada print-signatures"
1482 Control whether parameter types and return types are displayed in overloads
1483 selection menus. It is activaled (@code{on}) by default.
1487 Controls the maximum size of memory, in bytes, that GDB will
1488 allocate for value contents. Prevents incorrect programs from
1489 causing GDB to allocate overly large buffers. Default is 64k.
1491 * The "disassemble" command accepts a new modifier: /s.
1492 It prints mixed source+disassembly like /m with two differences:
1493 - disassembled instructions are now printed in program order, and
1494 - and source for all relevant files is now printed.
1495 The "/m" option is now considered deprecated: its "source-centric"
1496 output hasn't proved useful in practice.
1498 * The "record instruction-history" command accepts a new modifier: /s.
1499 It behaves exactly like /m and prints mixed source+disassembly.
1501 * The "set scheduler-locking" command supports a new mode "replay".
1502 It behaves like "off" in record mode and like "on" in replay mode.
1504 * Support for various ROM monitors has been removed:
1506 target dbug dBUG ROM monitor for Motorola ColdFire
1507 target picobug Motorola picobug monitor
1508 target dink32 DINK32 ROM monitor for PowerPC
1509 target m32r Renesas M32R/D ROM monitor
1510 target mon2000 mon2000 ROM monitor
1511 target ppcbug PPCBUG ROM monitor for PowerPC
1513 * Support for reading/writing memory and extracting values on architectures
1514 whose memory is addressable in units of any integral multiple of 8 bits.
1517 Allows to break when an Ada exception is handled.
1519 * New remote packets
1522 Indicates that an exec system call was executed.
1524 exec-events feature in qSupported
1525 The qSupported packet allows GDB to request support for exec
1526 events using the new 'gdbfeature' exec-event, and the qSupported
1527 response can contain the corresponding 'stubfeature'. Set and
1528 show commands can be used to display whether these features are enabled.
1531 Equivalent to interrupting with the ^C character, but works in
1534 thread created stop reason (T05 create:...)
1535 Indicates that the thread was just created and is stopped at entry.
1537 thread exit stop reply (w exitcode;tid)
1538 Indicates that the thread has terminated.
1541 Enables/disables thread create and exit event reporting. For
1542 example, this is used in non-stop mode when GDB stops a set of
1543 threads and synchronously waits for the their corresponding stop
1544 replies. Without exit events, if one of the threads exits, GDB
1545 would hang forever not knowing that it should no longer expect a
1546 stop for that same thread.
1549 Indicates that there are no resumed threads left in the target (all
1550 threads are stopped). The remote stub reports support for this stop
1551 reply to GDB's qSupported query.
1554 Enables/disables catching syscalls from the inferior process.
1555 The remote stub reports support for this packet to GDB's qSupported query.
1557 syscall_entry stop reason
1558 Indicates that a syscall was just called.
1560 syscall_return stop reason
1561 Indicates that a syscall just returned.
1563 * Extended-remote exec events
1565 ** GDB now has support for exec events on extended-remote Linux targets.
1566 For such targets with Linux kernels 2.5.46 and later, this enables
1567 follow-exec-mode and exec catchpoints.
1569 set remote exec-event-feature-packet
1570 show remote exec-event-feature-packet
1571 Set/show the use of the remote exec event feature.
1573 * Thread names in remote protocol
1575 The reply to qXfer:threads:read may now include a name attribute for each
1578 * Target remote mode fork and exec events
1580 ** GDB now has support for fork and exec events on target remote mode
1581 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1582 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1583 fork and exec catchpoints.
1585 * Remote syscall events
1587 ** GDB now has support for catch syscall on remote Linux targets,
1588 currently enabled on x86/x86_64 architectures.
1590 set remote catch-syscall-packet
1591 show remote catch-syscall-packet
1592 Set/show the use of the remote catch syscall feature.
1596 ** The -var-set-format command now accepts the zero-hexadecimal
1597 format. It outputs data in hexadecimal format with zero-padding on the
1602 ** gdb.InferiorThread objects have a new attribute "global_num",
1603 which refers to the thread's global thread ID. The existing
1604 "num" attribute now refers to the thread's per-inferior number.
1605 See "Per-inferior thread numbers" above.
1606 ** gdb.InferiorThread objects have a new attribute "inferior", which
1607 is the Inferior object the thread belongs to.
1609 *** Changes in GDB 7.10
1611 * Support for process record-replay and reverse debugging on aarch64*-linux*
1612 targets has been added. GDB now supports recording of A64 instruction set
1613 including advance SIMD instructions.
1615 * Support for Sun's version of the "stabs" debug file format has been removed.
1617 * GDB now honors the content of the file /proc/PID/coredump_filter
1618 (PID is the process ID) on GNU/Linux systems. This file can be used
1619 to specify the types of memory mappings that will be included in a
1620 corefile. For more information, please refer to the manual page of
1621 "core(5)". GDB also has a new command: "set use-coredump-filter
1622 on|off". It allows to set whether GDB will read the content of the
1623 /proc/PID/coredump_filter file when generating a corefile.
1625 * The "info os" command on GNU/Linux can now display information on
1627 "info os cpus" Listing of all cpus/cores on the system
1629 * GDB has two new commands: "set serial parity odd|even|none" and
1630 "show serial parity". These allows to set or show parity for the
1633 * The "info source" command now displays the producer string if it was
1634 present in the debug info. This typically includes the compiler version
1635 and may include things like its command line arguments.
1637 * The "info dll", an alias of the "info sharedlibrary" command,
1638 is now available on all platforms.
1640 * Directory names supplied to the "set sysroot" commands may be
1641 prefixed with "target:" to tell GDB to access shared libraries from
1642 the target system, be it local or remote. This replaces the prefix
1643 "remote:". The default sysroot has been changed from "" to
1644 "target:". "remote:" is automatically converted to "target:" for
1645 backward compatibility.
1647 * The system root specified by "set sysroot" will be prepended to the
1648 filename of the main executable (if reported to GDB as absolute by
1649 the operating system) when starting processes remotely, and when
1650 attaching to already-running local or remote processes.
1652 * GDB now supports automatic location and retrieval of executable
1653 files from remote targets. Remote debugging can now be initiated
1654 using only a "target remote" or "target extended-remote" command
1655 (no "set sysroot" or "file" commands are required). See "New remote
1658 * The "dump" command now supports verilog hex format.
1660 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1662 * On GNU/Linux, GDB and gdbserver are now able to access executable
1663 and shared library files without a "set sysroot" command when
1664 attaching to processes running in different mount namespaces from
1665 the debugger. This makes it possible to attach to processes in
1666 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1667 See "New remote packets" below.
1669 * The "tui reg" command now provides completion for all of the
1670 available register groups, including target specific groups.
1672 * The HISTSIZE environment variable is no longer read when determining
1673 the size of GDB's command history. GDB now instead reads the dedicated
1674 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1675 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1680 ** Memory ports can now be unbuffered.
1684 ** gdb.Objfile objects have a new attribute "username",
1685 which is the name of the objfile as specified by the user,
1686 without, for example, resolving symlinks.
1687 ** You can now write frame unwinders in Python.
1688 ** gdb.Type objects have a new method "optimized_out",
1689 returning optimized out gdb.Value instance of this type.
1690 ** gdb.Value objects have new methods "reference_value" and
1691 "const_value" which return a reference to the value and a
1692 "const" version of the value respectively.
1696 maint print symbol-cache
1697 Print the contents of the symbol cache.
1699 maint print symbol-cache-statistics
1700 Print statistics of symbol cache usage.
1702 maint flush-symbol-cache
1703 Flush the contents of the symbol cache.
1707 Start branch trace recording using Branch Trace Store (BTS) format.
1710 Evaluate expression by using the compiler and print result.
1714 Explicit commands for enabling and disabling tui mode.
1717 set mpx bound on i386 and amd64
1718 Support for bound table investigation on Intel MPX enabled applications.
1722 Start branch trace recording using Intel Processor Trace format.
1725 Print information about branch tracing internals.
1727 maint btrace packet-history
1728 Print the raw branch tracing data.
1730 maint btrace clear-packet-history
1731 Discard the stored raw branch tracing data.
1734 Discard all branch tracing data. It will be fetched and processed
1735 anew by the next "record" command.
1740 Renamed from "set debug dwarf2-die".
1741 show debug dwarf-die
1742 Renamed from "show debug dwarf2-die".
1744 set debug dwarf-read
1745 Renamed from "set debug dwarf2-read".
1746 show debug dwarf-read
1747 Renamed from "show debug dwarf2-read".
1749 maint set dwarf always-disassemble
1750 Renamed from "maint set dwarf2 always-disassemble".
1751 maint show dwarf always-disassemble
1752 Renamed from "maint show dwarf2 always-disassemble".
1754 maint set dwarf max-cache-age
1755 Renamed from "maint set dwarf2 max-cache-age".
1756 maint show dwarf max-cache-age
1757 Renamed from "maint show dwarf2 max-cache-age".
1759 set debug dwarf-line
1760 show debug dwarf-line
1761 Control display of debugging info regarding DWARF line processing.
1764 show max-completions
1765 Set the maximum number of candidates to be considered during
1766 completion. The default value is 200. This limit allows GDB
1767 to avoid generating large completion lists, the computation of
1768 which can cause the debugger to become temporarily unresponsive.
1770 set history remove-duplicates
1771 show history remove-duplicates
1772 Control the removal of duplicate history entries.
1774 maint set symbol-cache-size
1775 maint show symbol-cache-size
1776 Control the size of the symbol cache.
1778 set|show record btrace bts buffer-size
1779 Set and show the size of the ring buffer used for branch tracing in
1781 The obtained size may differ from the requested size. Use "info
1782 record" to see the obtained buffer size.
1784 set debug linux-namespaces
1785 show debug linux-namespaces
1786 Control display of debugging info regarding Linux namespaces.
1788 set|show record btrace pt buffer-size
1789 Set and show the size of the ring buffer used for branch tracing in
1790 Intel Processor Trace format.
1791 The obtained size may differ from the requested size. Use "info
1792 record" to see the obtained buffer size.
1794 maint set|show btrace pt skip-pad
1795 Set and show whether PAD packets are skipped when computing the
1798 * The command 'thread apply all' can now support new option '-ascending'
1799 to call its specified command for all threads in ascending order.
1801 * Python/Guile scripting
1803 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1804 special section named `.debug_gdb_scripts'.
1806 * New remote packets
1808 qXfer:btrace-conf:read
1809 Return the branch trace configuration for the current thread.
1811 Qbtrace-conf:bts:size
1812 Set the requested ring buffer size for branch tracing in BTS format.
1815 Enable Intel Procesor Trace-based branch tracing for the current
1816 process. The remote stub reports support for this packet to GDB's
1819 Qbtrace-conf:pt:size
1820 Set the requested ring buffer size for branch tracing in Intel Processor
1824 Indicates a memory breakpoint instruction was executed, irrespective
1825 of whether it was GDB that planted the breakpoint or the breakpoint
1826 is hardcoded in the program. This is required for correct non-stop
1830 Indicates the target stopped for a hardware breakpoint. This is
1831 required for correct non-stop mode operation.
1834 Return information about files on the remote system.
1836 qXfer:exec-file:read
1837 Return the full absolute name of the file that was executed to
1838 create a process running on the remote system.
1841 Select the filesystem on which vFile: operations with filename
1842 arguments will operate. This is required for GDB to be able to
1843 access files on remote targets where the remote stub does not
1844 share a common filesystem with the inferior(s).
1847 Indicates that a fork system call was executed.
1850 Indicates that a vfork system call was executed.
1852 vforkdone stop reason
1853 Indicates that a vfork child of the specified process has executed
1854 an exec or exit, allowing the vfork parent to resume execution.
1856 fork-events and vfork-events features in qSupported
1857 The qSupported packet allows GDB to request support for fork and
1858 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1859 and the qSupported response can contain the corresponding
1860 'stubfeatures'. Set and show commands can be used to display
1861 whether these features are enabled.
1863 * Extended-remote fork events
1865 ** GDB now has support for fork events on extended-remote Linux
1866 targets. For targets with Linux kernels 2.5.60 and later, this
1867 enables follow-fork-mode and detach-on-fork for both fork and
1868 vfork, as well as fork and vfork catchpoints.
1870 * The info record command now shows the recording format and the
1871 branch tracing configuration for the current thread when using
1872 the btrace record target.
1873 For the BTS format, it shows the ring buffer size.
1875 * GDB now has support for DTrace USDT (Userland Static Defined
1876 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1878 * GDB now supports access to vector registers on S/390 GNU/Linux
1881 * Removed command line options
1883 -xdb HP-UX XDB compatibility mode.
1885 * Removed targets and native configurations
1887 HP/PA running HP-UX hppa*-*-hpux*
1888 Itanium running HP-UX ia64-*-hpux*
1890 * New configure options
1893 This configure option allows the user to build GDB with support for
1894 Intel Processor Trace (default: auto). This requires libipt.
1896 --with-libipt-prefix=PATH
1897 Specify the path to the version of libipt that GDB should use.
1898 $PATH/include should contain the intel-pt.h header and
1899 $PATH/lib should contain the libipt.so library.
1901 *** Changes in GDB 7.9.1
1905 ** Xmethods can now specify a result type.
1907 *** Changes in GDB 7.9
1909 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1913 ** You can now access frame registers from Python scripts.
1914 ** New attribute 'producer' for gdb.Symtab objects.
1915 ** gdb.Objfile objects have a new attribute "progspace",
1916 which is the gdb.Progspace object of the containing program space.
1917 ** gdb.Objfile objects have a new attribute "owner".
1918 ** gdb.Objfile objects have a new attribute "build_id",
1919 which is the build ID generated when the file was built.
1920 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1921 ** A new event "gdb.clear_objfiles" has been added, triggered when
1922 selecting a new file to debug.
1923 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1924 ** New function gdb.lookup_objfile.
1926 New events which are triggered when GDB modifies the state of the
1929 ** gdb.events.inferior_call_pre: Function call is about to be made.
1930 ** gdb.events.inferior_call_post: Function call has just been made.
1931 ** gdb.events.memory_changed: A memory location has been altered.
1932 ** gdb.events.register_changed: A register has been altered.
1934 * New Python-based convenience functions:
1936 ** $_caller_is(name [, number_of_frames])
1937 ** $_caller_matches(regexp [, number_of_frames])
1938 ** $_any_caller_is(name [, number_of_frames])
1939 ** $_any_caller_matches(regexp [, number_of_frames])
1941 * GDB now supports the compilation and injection of source code into
1942 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1943 to compile the source code to object code, and if successful, inject
1944 and execute that code within the current context of the inferior.
1945 Currently the C language is supported. The commands used to
1946 interface with this new feature are:
1948 compile code [-raw|-r] [--] [source code]
1949 compile file [-raw|-r] filename
1953 demangle [-l language] [--] name
1954 Demangle "name" in the specified language, or the current language
1955 if elided. This command is renamed from the "maint demangle" command.
1956 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1957 as "maint demangler-warning".
1959 queue-signal signal-name-or-number
1960 Queue a signal to be delivered to the thread when it is resumed.
1962 add-auto-load-scripts-directory directory
1963 Add entries to the list of directories from which to load auto-loaded
1966 maint print user-registers
1967 List all currently available "user" registers.
1969 compile code [-r|-raw] [--] [source code]
1970 Compile, inject, and execute in the inferior the executable object
1971 code produced by compiling the provided source code.
1973 compile file [-r|-raw] filename
1974 Compile and inject into the inferior the executable object code
1975 produced by compiling the source code stored in the filename
1978 * On resume, GDB now always passes the signal the program had stopped
1979 for to the thread the signal was sent to, even if the user changed
1980 threads before resuming. Previously GDB would often (but not
1981 always) deliver the signal to the thread that happens to be current
1984 * Conversely, the "signal" command now consistently delivers the
1985 requested signal to the current thread. GDB now asks for
1986 confirmation if the program had stopped for a signal and the user
1987 switched threads meanwhile.
1989 * "breakpoint always-inserted" modes "off" and "auto" merged.
1991 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1992 won't remove breakpoints from the target until all threads stop,
1993 even in non-stop mode. The "auto" mode has been removed, and "off"
1994 is now the default mode.
1998 set debug symbol-lookup
1999 show debug symbol-lookup
2000 Control display of debugging info regarding symbol lookup.
2004 ** The -list-thread-groups command outputs an exit-code field for
2005 inferiors that have exited.
2009 MIPS SDE mips*-sde*-elf*
2013 Support for these obsolete configurations has been removed.
2015 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2016 SGI Irix-5.x mips-*-irix5*
2017 SGI Irix-6.x mips-*-irix6*
2018 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2019 VAX running Ultrix vax-*-ultrix*
2021 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2022 and "assf"), have been removed. Use the "sharedlibrary" command, or
2023 its alias "share", instead.
2025 *** Changes in GDB 7.8
2027 * New command line options
2030 This is an alias for the --data-directory option.
2032 * GDB supports printing and modifying of variable length automatic arrays
2033 as specified in ISO C99.
2035 * The ARM simulator now supports instruction level tracing
2036 with or without disassembly.
2040 GDB now has support for scripting using Guile. Whether this is
2041 available is determined at configure time.
2042 Guile version 2.0 or greater is required.
2043 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2045 * New commands (for set/show, see "New options" below)
2049 Invoke CODE by passing it to the Guile interpreter.
2053 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2055 info auto-load guile-scripts [regexp]
2056 Print the list of automatically loaded Guile scripts.
2058 * The source command is now capable of sourcing Guile scripts.
2059 This feature is dependent on the debugger being built with Guile support.
2063 set print symbol-loading (off|brief|full)
2064 show print symbol-loading
2065 Control whether to print informational messages when loading symbol
2066 information for a file. The default is "full", but when debugging
2067 programs with large numbers of shared libraries the amount of output
2068 becomes less useful.
2070 set guile print-stack (none|message|full)
2071 show guile print-stack
2072 Show a stack trace when an error is encountered in a Guile script.
2074 set auto-load guile-scripts (on|off)
2075 show auto-load guile-scripts
2076 Control auto-loading of Guile script files.
2078 maint ada set ignore-descriptive-types (on|off)
2079 maint ada show ignore-descriptive-types
2080 Control whether the debugger should ignore descriptive types in Ada
2081 programs. The default is not to ignore the descriptive types. See
2082 the user manual for more details on descriptive types and the intended
2083 usage of this option.
2085 set auto-connect-native-target
2087 Control whether GDB is allowed to automatically connect to the
2088 native target for the run, attach, etc. commands when not connected
2089 to any target yet. See also "target native" below.
2091 set record btrace replay-memory-access (read-only|read-write)
2092 show record btrace replay-memory-access
2093 Control what memory accesses are allowed during replay.
2095 maint set target-async (on|off)
2096 maint show target-async
2097 This controls whether GDB targets operate in synchronous or
2098 asynchronous mode. Normally the default is asynchronous, if it is
2099 available; but this can be changed to more easily debug problems
2100 occurring only in synchronous mode.
2102 set mi-async (on|off)
2104 Control whether MI asynchronous mode is preferred. This supersedes
2105 "set target-async" of previous GDB versions.
2107 * "set target-async" is deprecated as a CLI option and is now an alias
2108 for "set mi-async" (only puts MI into async mode).
2110 * Background execution commands (e.g., "c&", "s&", etc.) are now
2111 possible ``out of the box'' if the target supports them. Previously
2112 the user would need to explicitly enable the possibility with the
2113 "set target-async on" command.
2115 * New features in the GDB remote stub, GDBserver
2117 ** New option --debug-format=option1[,option2,...] allows one to add
2118 additional text to each output. At present only timestamps
2119 are supported: --debug-format=timestamps.
2120 Timestamps can also be turned on with the
2121 "monitor set debug-format timestamps" command from GDB.
2123 * The 'record instruction-history' command now starts counting instructions
2124 at one. This also affects the instruction ranges reported by the
2125 'record function-call-history' command when given the /i modifier.
2127 * The command 'record function-call-history' supports a new modifier '/c' to
2128 indent the function names based on their call stack depth.
2129 The fields for the '/i' and '/l' modifier have been reordered.
2130 The source line range is now prefixed with 'at'.
2131 The instruction range is now prefixed with 'inst'.
2132 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2133 "record instruction-history" and "list" commands.
2135 * The ranges given as arguments to the 'record function-call-history' and
2136 'record instruction-history' commands are now inclusive.
2138 * The btrace record target now supports the 'record goto' command.
2139 For locations inside the execution trace, the back trace is computed
2140 based on the information stored in the execution trace.
2142 * The btrace record target supports limited reverse execution and replay.
2143 The target does not record data and therefore does not allow reading
2144 memory or registers.
2146 * The "catch syscall" command now works on s390*-linux* targets.
2148 * The "compare-sections" command is no longer specific to target
2149 remote. It now works with all targets.
2151 * All native targets are now consistently called "native".
2152 Consequently, the "target child", "target GNU", "target djgpp",
2153 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2154 commands have been replaced with "target native". The QNX/NTO port
2155 leaves the "procfs" target in place and adds a "native" target for
2156 consistency with other ports. The impact on users should be minimal
2157 as these commands previously either throwed an error, or were
2158 no-ops. The target's name is visible in the output of the following
2159 commands: "help target", "info target", "info files", "maint print
2162 * The "target native" command now connects to the native target. This
2163 can be used to launch native programs even when "set
2164 auto-connect-native-target" is set to off.
2166 * GDB now supports access to Intel MPX registers on GNU/Linux.
2168 * Support for Intel AVX-512 registers on GNU/Linux.
2169 Support displaying and modifying Intel AVX-512 registers
2170 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2172 * New remote packets
2174 qXfer:btrace:read's annex
2175 The qXfer:btrace:read packet supports a new annex 'delta' to read
2176 branch trace incrementally.
2180 ** Valid Python operations on gdb.Value objects representing
2181 structs/classes invoke the corresponding overloaded operators if
2183 ** New `Xmethods' feature in the Python API. Xmethods are
2184 additional methods or replacements for existing methods of a C++
2185 class. This feature is useful for those cases where a method
2186 defined in C++ source code could be inlined or optimized out by
2187 the compiler, making it unavailable to GDB.
2190 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2192 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2193 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2194 its alias "share", instead.
2196 * The commands "set remotebaud" and "show remotebaud" are no longer
2197 supported. Use "set serial baud" and "show serial baud" (respectively)
2202 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2203 target-async". The latter is left as a deprecated alias of the
2204 former for backward compatibility. If the target supports it,
2205 CLI background execution commands are now always possible by
2206 default, independently of whether the frontend stated a
2207 preference for asynchronous execution with "-gdb-set mi-async".
2208 Previously "-gdb-set target-async off" affected both MI execution
2209 commands and CLI execution commands.
2211 *** Changes in GDB 7.7
2213 * Improved support for process record-replay and reverse debugging on
2214 arm*-linux* targets. Support for thumb32 and syscall instruction
2215 recording has been added.
2217 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2219 * GDB now supports Fission DWP file format version 2.
2220 http://gcc.gnu.org/wiki/DebugFission
2222 * New convenience function "$_isvoid", to check whether an expression
2223 is void. A void expression is an expression where the type of the
2224 result is "void". For example, some convenience variables may be
2225 "void" when evaluated (e.g., "$_exitcode" before the execution of
2226 the program being debugged; or an undefined convenience variable).
2227 Another example, when calling a function whose return type is
2230 * The "maintenance print objfiles" command now takes an optional regexp.
2232 * The "catch syscall" command now works on arm*-linux* targets.
2234 * GDB now consistently shows "<not saved>" when printing values of
2235 registers the debug info indicates have not been saved in the frame
2236 and there's nowhere to retrieve them from
2237 (callee-saved/call-clobbered registers):
2242 (gdb) info registers rax
2245 Before, the former would print "<optimized out>", and the latter
2246 "*value not available*".
2248 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2253 ** Frame filters and frame decorators have been added.
2254 ** Temporary breakpoints are now supported.
2255 ** Line tables representation has been added.
2256 ** New attribute 'parent_type' for gdb.Field objects.
2257 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2258 ** New attribute 'name' for gdb.Type objects.
2262 Nios II ELF nios2*-*-elf
2263 Nios II GNU/Linux nios2*-*-linux
2264 Texas Instruments MSP430 msp430*-*-elf
2266 * Removed native configurations
2268 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2269 been removed. ELF variants of these configurations are kept supported.
2271 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2272 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2273 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2274 i[34567]86-*-openbsd3.[0-3]
2275 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2276 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2277 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2281 Like "catch throw", but catches a re-thrown exception.
2282 maint check-psymtabs
2283 Renamed from old "maint check-symtabs".
2285 Perform consistency checks on symtabs.
2286 maint expand-symtabs
2287 Expand symtabs matching an optional regexp.
2290 Display the details of GDB configure-time options.
2292 maint set|show per-command
2293 maint set|show per-command space
2294 maint set|show per-command time
2295 maint set|show per-command symtab
2296 Enable display of per-command gdb resource usage.
2298 remove-symbol-file FILENAME
2299 remove-symbol-file -a ADDRESS
2300 Remove a symbol file added via add-symbol-file. The file to remove
2301 can be identified by its filename or by an address that lies within
2302 the boundaries of this symbol file in memory.
2305 info exceptions REGEXP
2306 Display the list of Ada exceptions defined in the program being
2307 debugged. If provided, only the exceptions whose names match REGEXP
2312 set debug symfile off|on
2314 Control display of debugging info regarding reading symbol files and
2315 symbol tables within those files
2317 set print raw frame-arguments
2318 show print raw frame-arguments
2319 Set/show whether to print frame arguments in raw mode,
2320 disregarding any defined pretty-printers.
2322 set remote trace-status-packet
2323 show remote trace-status-packet
2324 Set/show the use of remote protocol qTStatus packet.
2328 Control display of debugging messages related to Nios II targets.
2332 Control whether target-assisted range stepping is enabled.
2334 set startup-with-shell
2335 show startup-with-shell
2336 Specifies whether Unix child processes are started via a shell or
2341 Use the target memory cache for accesses to the code segment. This
2342 improves performance of remote debugging (particularly disassembly).
2344 * You can now use a literal value 'unlimited' for options that
2345 interpret 0 or -1 as meaning "unlimited". E.g., "set
2346 trace-buffer-size unlimited" is now an alias for "set
2347 trace-buffer-size -1" and "set height unlimited" is now an alias for
2350 * The "set debug symtab-create" debugging option of GDB has been changed to
2351 accept a verbosity level. 0 means "off", 1 provides basic debugging
2352 output, and values of 2 or greater provides more verbose output.
2354 * New command-line options
2356 Display the details of GDB configure-time options.
2358 * The command 'tsave' can now support new option '-ctf' to save trace
2359 buffer in Common Trace Format.
2361 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2364 * GDB now implements the the C++ 'typeid' operator.
2366 * The new convenience variable $_exception holds the exception being
2367 thrown or caught at an exception-related catchpoint.
2369 * The exception-related catchpoints, like "catch throw", now accept a
2370 regular expression which can be used to filter exceptions by type.
2372 * The new convenience variable $_exitsignal is automatically set to
2373 the terminating signal number when the program being debugged dies
2374 due to an uncaught signal.
2378 ** All MI commands now accept an optional "--language" option.
2379 Support for this feature can be verified by using the "-list-features"
2380 command, which should contain "language-option".
2382 ** The new command -info-gdb-mi-command allows the user to determine
2383 whether a GDB/MI command is supported or not.
2385 ** The "^error" result record returned when trying to execute an undefined
2386 GDB/MI command now provides a variable named "code" whose content is the
2387 "undefined-command" error code. Support for this feature can be verified
2388 by using the "-list-features" command, which should contain
2389 "undefined-command-error-code".
2391 ** The -trace-save MI command can optionally save trace buffer in Common
2394 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2396 ** The command -data-list-register-values now accepts an optional
2397 "--skip-unavailable" option. When used, only the available registers
2400 ** The new command -trace-frame-collected dumps collected variables,
2401 computed expressions, tvars, memory and registers in a traceframe.
2403 ** The commands -stack-list-locals, -stack-list-arguments and
2404 -stack-list-variables now accept an option "--skip-unavailable".
2405 When used, only the available locals or arguments are displayed.
2407 ** The -exec-run command now accepts an optional "--start" option.
2408 When used, the command follows the same semantics as the "start"
2409 command, stopping the program's execution at the start of its
2410 main subprogram. Support for this feature can be verified using
2411 the "-list-features" command, which should contain
2412 "exec-run-start-option".
2414 ** The new commands -catch-assert and -catch-exceptions insert
2415 catchpoints stopping the program when Ada exceptions are raised.
2417 ** The new command -info-ada-exceptions provides the equivalent of
2418 the new "info exceptions" command.
2420 * New system-wide configuration scripts
2421 A GDB installation now provides scripts suitable for use as system-wide
2422 configuration scripts for the following systems:
2426 * GDB now supports target-assigned range stepping with remote targets.
2427 This improves the performance of stepping source lines by reducing
2428 the number of control packets from/to GDB. See "New remote packets"
2431 * GDB now understands the element 'tvar' in the XML traceframe info.
2432 It has the id of the collected trace state variables.
2434 * On S/390 targets that provide the transactional-execution feature,
2435 the program interruption transaction diagnostic block (TDB) is now
2436 represented as a number of additional "registers" in GDB.
2438 * New remote packets
2442 The vCont packet supports a new 'r' action, that tells the remote
2443 stub to step through an address range itself, without GDB
2444 involvemement at each single-step.
2446 qXfer:libraries-svr4:read's annex
2447 The previously unused annex of the qXfer:libraries-svr4:read packet
2448 is now used to support passing an argument list. The remote stub
2449 reports support for this argument list to GDB's qSupported query.
2450 The defined arguments are "start" and "prev", used to reduce work
2451 necessary for library list updating, resulting in significant
2454 * New features in the GDB remote stub, GDBserver
2456 ** GDBserver now supports target-assisted range stepping. Currently
2457 enabled on x86/x86_64 GNU/Linux targets.
2459 ** GDBserver now adds element 'tvar' in the XML in the reply to
2460 'qXfer:traceframe-info:read'. It has the id of the collected
2461 trace state variables.
2463 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2466 * New 'z' formatter for printing and examining memory, this displays the
2467 value as hexadecimal zero padded on the left to the size of the type.
2469 * GDB can now use Windows x64 unwinding data.
2471 * The "set remotebaud" command has been replaced by "set serial baud".
2472 Similarly, "show remotebaud" has been replaced by "show serial baud".
2473 The "set remotebaud" and "show remotebaud" commands are still available
2474 to provide backward compatibility with older versions of GDB.
2476 *** Changes in GDB 7.6
2478 * Target record has been renamed to record-full.
2479 Record/replay is now enabled with the "record full" command.
2480 This also affects settings that are associated with full record/replay
2481 that have been moved from "set/show record" to "set/show record full":
2483 set|show record full insn-number-max
2484 set|show record full stop-at-limit
2485 set|show record full memory-query
2487 * A new record target "record-btrace" has been added. The new target
2488 uses hardware support to record the control-flow of a process. It
2489 does not support replaying the execution, but it implements the
2490 below new commands for investigating the recorded execution log.
2491 This new recording method can be enabled using:
2495 The "record-btrace" target is only available on Intel Atom processors
2496 and requires a Linux kernel 2.6.32 or later.
2498 * Two new commands have been added for record/replay to give information
2499 about the recorded execution without having to replay the execution.
2500 The commands are only supported by "record btrace".
2502 record instruction-history prints the execution history at
2503 instruction granularity
2505 record function-call-history prints the execution history at
2506 function granularity
2508 * New native configurations
2510 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2511 FreeBSD/powerpc powerpc*-*-freebsd
2512 x86_64/Cygwin x86_64-*-cygwin*
2513 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2517 ARM AArch64 aarch64*-*-elf
2518 ARM AArch64 GNU/Linux aarch64*-*-linux
2519 Lynx 178 PowerPC powerpc-*-lynx*178
2520 x86_64/Cygwin x86_64-*-cygwin*
2521 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2523 * If the configured location of system.gdbinit file (as given by the
2524 --with-system-gdbinit option at configure time) is in the
2525 data-directory (as specified by --with-gdb-datadir at configure
2526 time) or in one of its subdirectories, then GDB will look for the
2527 system-wide init file in the directory specified by the
2528 --data-directory command-line option.
2530 * New command line options:
2532 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2533 other initialization files, unlike -nx which disables all of them.
2535 * Removed command line options
2537 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2540 * The 'ptype' and 'whatis' commands now accept an argument to control
2543 * 'info proc' now works on some core files.
2547 ** Vectors can be created with gdb.Type.vector.
2549 ** Python's atexit.register now works in GDB.
2551 ** Types can be pretty-printed via a Python API.
2553 ** Python 3 is now supported (in addition to Python 2.4 or later)
2555 ** New class gdb.Architecture exposes GDB's internal representation
2556 of architecture in the Python API.
2558 ** New method Frame.architecture returns the gdb.Architecture object
2559 corresponding to the frame's architecture.
2561 * New Python-based convenience functions:
2563 ** $_memeq(buf1, buf2, length)
2564 ** $_streq(str1, str2)
2566 ** $_regex(str, regex)
2568 * The 'cd' command now defaults to using '~' (the home directory) if not
2571 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2572 default for GCC since November 2000.
2574 * The command 'forward-search' can now be abbreviated as 'fo'.
2576 * The command 'info tracepoints' can now display 'installed on target'
2577 or 'not installed on target' for each non-pending location of tracepoint.
2579 * New configure options
2581 --enable-libmcheck/--disable-libmcheck
2582 By default, development versions are built with -lmcheck on hosts
2583 that support it, in order to help track memory corruption issues.
2584 Release versions, on the other hand, are built without -lmcheck
2585 by default. The --enable-libmcheck/--disable-libmcheck configure
2586 options allow the user to override that default.
2587 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2588 This configure option allows the user to build GDB with
2589 libbabeltrace using which GDB can read Common Trace Format data.
2591 * New commands (for set/show, see "New options" below)
2594 Catch signals. This is similar to "handle", but allows commands and
2595 conditions to be attached.
2598 List the BFDs known to GDB.
2600 python-interactive [command]
2602 Start a Python interactive prompt, or evaluate the optional command
2603 and print the result of expressions.
2606 "py" is a new alias for "python".
2608 enable type-printer [name]...
2609 disable type-printer [name]...
2610 Enable or disable type printers.
2614 ** For the Renesas Super-H architecture, the "regs" command has been removed
2615 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2620 set print type methods (on|off)
2621 show print type methods
2622 Control whether method declarations are displayed by "ptype".
2623 The default is to show them.
2625 set print type typedefs (on|off)
2626 show print type typedefs
2627 Control whether typedef definitions are displayed by "ptype".
2628 The default is to show them.
2630 set filename-display basename|relative|absolute
2631 show filename-display
2632 Control the way in which filenames is displayed.
2633 The default is "relative", which preserves previous behavior.
2635 set trace-buffer-size
2636 show trace-buffer-size
2637 Request target to change the size of trace buffer.
2639 set remote trace-buffer-size-packet auto|on|off
2640 show remote trace-buffer-size-packet
2641 Control the use of the remote protocol `QTBuffer:size' packet.
2645 Control display of debugging messages related to ARM AArch64.
2648 set debug coff-pe-read
2649 show debug coff-pe-read
2650 Control display of debugging messages related to reading of COFF/PE
2655 Control display of debugging messages related to Mach-O symbols
2658 set debug notification
2659 show debug notification
2660 Control display of debugging info for async remote notification.
2664 ** Command parameter changes are now notified using new async record
2665 "=cmd-param-changed".
2666 ** Trace frame changes caused by command "tfind" are now notified using
2667 new async record "=traceframe-changed".
2668 ** The creation, deletion and modification of trace state variables
2669 are now notified using new async records "=tsv-created",
2670 "=tsv-deleted" and "=tsv-modified".
2671 ** The start and stop of process record are now notified using new
2672 async record "=record-started" and "=record-stopped".
2673 ** Memory changes are now notified using new async record
2675 ** The data-disassemble command response will include a "fullname" field
2676 containing the absolute file name when source has been requested.
2677 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2678 command, to allow pattern filling of memory areas.
2679 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2680 library load/unload events.
2681 ** The response to breakpoint commands and breakpoint async records
2682 includes an "installed" field containing a boolean state about each
2683 non-pending tracepoint location is whether installed on target or not.
2684 ** Output of the "-trace-status" command includes a "trace-file" field
2685 containing the name of the trace file being examined. This field is
2686 optional, and only present when examining a trace file.
2687 ** The "fullname" field is now always present along with the "file" field,
2688 even if the file cannot be found by GDB.
2690 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2691 You must have the LZMA library available when configuring GDB for this
2692 feature to be enabled. For more information, see:
2693 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2695 * New remote packets
2698 Set the size of trace buffer. The remote stub reports support for this
2699 packet to gdb's qSupported query.
2702 Enable Branch Trace Store (BTS)-based branch tracing for the current
2703 thread. The remote stub reports support for this packet to gdb's
2707 Disable branch tracing for the current thread. The remote stub reports
2708 support for this packet to gdb's qSupported query.
2711 Read the traced branches for the current thread. The remote stub
2712 reports support for this packet to gdb's qSupported query.
2714 *** Changes in GDB 7.5
2716 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2717 for more x32 ABI info.
2719 * GDB now supports access to MIPS DSP registers on Linux targets.
2721 * GDB now supports debugging microMIPS binaries.
2723 * The "info os" command on GNU/Linux can now display information on
2724 several new classes of objects managed by the operating system:
2725 "info os procgroups" lists process groups
2726 "info os files" lists file descriptors
2727 "info os sockets" lists internet-domain sockets
2728 "info os shm" lists shared-memory regions
2729 "info os semaphores" lists semaphores
2730 "info os msg" lists message queues
2731 "info os modules" lists loaded kernel modules
2733 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2734 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2735 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2736 options and inspect the probe arguments using the new $_probe_arg family
2737 of convenience variables. You can obtain more information about SystemTap
2738 in <http://sourceware.org/systemtap/>.
2740 * GDB now supports reversible debugging on ARM, it allows you to
2741 debug basic ARM and THUMB instructions, and provides
2742 record/replay support.
2744 * The option "symbol-reloading" has been deleted as it is no longer used.
2748 ** GDB commands implemented in Python can now be put in command class
2751 ** The "maint set python print-stack on|off" is now deleted.
2753 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2754 apply "flag enum"-style pretty-printing to any enum.
2756 ** gdb.lookup_symbol can now work when there is no current frame.
2758 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2759 the source at which the symbol was defined.
2761 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2762 method 'value'. The former indicates whether the symbol needs a
2763 frame in order to compute its value, and the latter computes the
2766 ** A new method 'referenced_value' on gdb.Value objects which can
2767 dereference pointer as well as C++ reference values.
2769 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2770 which return the global and static blocks (as gdb.Block objects),
2771 of the underlying symbol table, respectively.
2773 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2774 object associated with a PC value.
2776 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2777 of the address range occupied by code for the current source line.
2779 * Go language support.
2780 GDB now supports debugging programs written in the Go programming
2783 * GDBserver now supports stdio connections.
2784 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2786 * The binary "gdbtui" can no longer be built or installed.
2787 Use "gdb -tui" instead.
2789 * GDB will now print "flag" enums specially. A flag enum is one where
2790 all the enumerator values have no bits in common when pairwise
2791 "and"ed. When printing a value whose type is a flag enum, GDB will
2792 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2793 (gdb) print (enum E) 3
2796 * The filename part of a linespec will now match trailing components
2797 of a source file name. For example, "break gcc/expr.c:1000" will
2798 now set a breakpoint in build/gcc/expr.c, but not
2799 build/libcpp/expr.c.
2801 * The "info proc" and "generate-core-file" commands will now also
2802 work on remote targets connected to GDBserver on Linux.
2804 * The command "info catch" has been removed. It has been disabled
2805 since December 2007.
2807 * The "catch exception" and "catch assert" commands now accept
2808 a condition at the end of the command, much like the "break"
2809 command does. For instance:
2811 (gdb) catch exception Constraint_Error if Barrier = True
2813 Previously, it was possible to add a condition to such catchpoints,
2814 but it had to be done as a second step, after the catchpoint had been
2815 created, using the "condition" command.
2817 * The "info static-tracepoint-marker" command will now also work on
2818 native Linux targets with in-process agent.
2820 * GDB can now set breakpoints on inlined functions.
2822 * The .gdb_index section has been updated to include symbols for
2823 inlined functions. GDB will ignore older .gdb_index sections by
2824 default, which could cause symbol files to be loaded more slowly
2825 until their .gdb_index sections can be recreated. The new command
2826 "set use-deprecated-index-sections on" will cause GDB to use any older
2827 .gdb_index sections it finds. This will restore performance, but the
2828 ability to set breakpoints on inlined functions will be lost in symbol
2829 files with older .gdb_index sections.
2831 The .gdb_index section has also been updated to record more information
2832 about each symbol. This speeds up the "info variables", "info functions"
2833 and "info types" commands when used with programs having the .gdb_index
2834 section, as well as speeding up debugging with shared libraries using
2835 the .gdb_index section.
2837 * Ada support for GDB/MI Variable Objects has been added.
2839 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2844 ** New command -info-os is the MI equivalent of "info os".
2846 ** Output logs ("set logging" and related) now include MI output.
2850 ** "set use-deprecated-index-sections on|off"
2851 "show use-deprecated-index-sections on|off"
2852 Controls the use of deprecated .gdb_index sections.
2854 ** "catch load" and "catch unload" can be used to stop when a shared
2855 library is loaded or unloaded, respectively.
2857 ** "enable count" can be used to auto-disable a breakpoint after
2860 ** "info vtbl" can be used to show the virtual method tables for
2861 C++ and Java objects.
2863 ** "explore" and its sub commands "explore value" and "explore type"
2864 can be used to recursively explore values and types of
2865 expressions. These commands are available only if GDB is
2866 configured with '--with-python'.
2868 ** "info auto-load" shows status of all kinds of auto-loaded files,
2869 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2870 sequences of commands files, "info auto-load python-scripts"
2871 shows status of auto-loading Python script files,
2872 "info auto-load local-gdbinit" shows status of loading init file
2873 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2874 status of inferior specific thread debugging shared library loading.
2876 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2877 and "show auto-load-scripts" commands have been deprecated, use their
2878 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2879 and "show auto-load python-scripts" counterparts instead.
2881 ** "dprintf location,format,args..." creates a dynamic printf, which
2882 is basically a breakpoint that does a printf and immediately
2883 resumes your program's execution, so it is like a printf that you
2884 can insert dynamically at runtime instead of at compiletime.
2886 ** "set print symbol"
2888 Controls whether GDB attempts to display the symbol, if any,
2889 corresponding to addresses it prints. This defaults to "on", but
2890 you can set it to "off" to restore GDB's previous behavior.
2892 * Deprecated commands
2894 ** For the Renesas Super-H architecture, the "regs" command has been
2895 deprecated, and "info all-registers" should be used instead.
2899 Renesas RL78 rl78-*-elf
2900 HP OpenVMS ia64 ia64-hp-openvms*
2902 * GDBserver supports evaluation of breakpoint conditions. When
2903 support is advertised by GDBserver, GDB may be told to send the
2904 breakpoint conditions in bytecode form to GDBserver. GDBserver
2905 will only report the breakpoint trigger to GDB when its condition
2910 set mips compression
2911 show mips compression
2912 Select the compressed ISA encoding used in functions that have no symbol
2913 information available. The encoding can be set to either of:
2916 and is updated automatically from ELF file flags if available.
2918 set breakpoint condition-evaluation
2919 show breakpoint condition-evaluation
2920 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2921 GDBserver ("target"). Default option "auto" chooses the most efficient
2923 This option can improve debugger efficiency depending on the speed of the
2927 Disable auto-loading globally.
2930 Show auto-loading setting of all kinds of auto-loaded files.
2932 set auto-load gdb-scripts on|off
2933 show auto-load gdb-scripts
2934 Control auto-loading of GDB canned sequences of commands files.
2936 set auto-load python-scripts on|off
2937 show auto-load python-scripts
2938 Control auto-loading of Python script files.
2940 set auto-load local-gdbinit on|off
2941 show auto-load local-gdbinit
2942 Control loading of init file (.gdbinit) from current directory.
2944 set auto-load libthread-db on|off
2945 show auto-load libthread-db
2946 Control auto-loading of inferior specific thread debugging shared library.
2948 set auto-load scripts-directory <dir1>[:<dir2>...]
2949 show auto-load scripts-directory
2950 Set a list of directories from which to load auto-loaded scripts.
2951 Automatically loaded Python scripts and GDB scripts are located in one
2952 of the directories listed by this option.
2953 The delimiter (':' above) may differ according to the host platform.
2955 set auto-load safe-path <dir1>[:<dir2>...]
2956 show auto-load safe-path
2957 Set a list of directories from which it is safe to auto-load files.
2958 The delimiter (':' above) may differ according to the host platform.
2960 set debug auto-load on|off
2961 show debug auto-load
2962 Control display of debugging info for auto-loading the files above.
2964 set dprintf-style gdb|call|agent
2966 Control the way in which a dynamic printf is performed; "gdb"
2967 requests a GDB printf command, while "call" causes dprintf to call a
2968 function in the inferior. "agent" requests that the target agent
2969 (such as GDBserver) do the printing.
2971 set dprintf-function <expr>
2972 show dprintf-function
2973 set dprintf-channel <expr>
2974 show dprintf-channel
2975 Set the function and optional first argument to the call when using
2976 the "call" style of dynamic printf.
2978 set disconnected-dprintf on|off
2979 show disconnected-dprintf
2980 Control whether agent-style dynamic printfs continue to be in effect
2981 after GDB disconnects.
2983 * New configure options
2985 --with-auto-load-dir
2986 Configure default value for the 'set auto-load scripts-directory'
2987 setting above. It defaults to '$debugdir:$datadir/auto-load',
2988 $debugdir representing global debugging info directories (available
2989 via 'show debug-file-directory') and $datadir representing GDB's data
2990 directory (available via 'show data-directory').
2992 --with-auto-load-safe-path
2993 Configure default value for the 'set auto-load safe-path' setting
2994 above. It defaults to the --with-auto-load-dir setting.
2996 --without-auto-load-safe-path
2997 Set 'set auto-load safe-path' to '/', effectively disabling this
3000 * New remote packets
3002 z0/z1 conditional breakpoints extension
3004 The z0/z1 breakpoint insertion packets have been extended to carry
3005 a list of conditional expressions over to the remote stub depending on the
3006 condition evaluation mode. The use of this extension can be controlled
3007 via the "set remote conditional-breakpoints-packet" command.
3011 Specify the signals which the remote stub may pass to the debugged
3012 program without GDB involvement.
3014 * New command line options
3016 --init-command=FILE, -ix Like --command, -x but execute it
3017 before loading inferior.
3018 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3019 execute it before loading inferior.
3021 *** Changes in GDB 7.4
3023 * GDB now handles ambiguous linespecs more consistently; the existing
3024 FILE:LINE support has been expanded to other types of linespecs. A
3025 breakpoint will now be set on all matching locations in all
3026 inferiors, and locations will be added or removed according to
3029 * GDB now allows you to skip uninteresting functions and files when
3030 stepping with the "skip function" and "skip file" commands.
3032 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3033 and "show remote hardware-watchpoint-length-limit". These allows to
3034 set or show the maximum length limit (in bytes) of a remote
3035 target hardware watchpoint.
3037 This allows e.g. to use "unlimited" hardware watchpoints with the
3038 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3039 watchpoints are slower than real hardware watchpoints but are
3040 significantly faster than gdb software watchpoints.
3044 ** The register_pretty_printer function in module gdb.printing now takes
3045 an optional `replace' argument. If True, the new printer replaces any
3048 ** The "maint set python print-stack on|off" command has been
3049 deprecated and will be deleted in GDB 7.5.
3050 A new command: "set python print-stack none|full|message" has
3051 replaced it. Additionally, the default for "print-stack" is
3052 now "message", which just prints the error message without
3055 ** A prompt substitution hook (prompt_hook) is now available to the
3058 ** A new Python module, gdb.prompt has been added to the GDB Python
3059 modules library. This module provides functionality for
3060 escape sequences in prompts (used by set/show
3061 extended-prompt). These escape sequences are replaced by their
3062 corresponding value.
3064 ** Python commands and convenience-functions located in
3065 'data-directory'/python/gdb/command and
3066 'data-directory'/python/gdb/function are now automatically loaded
3069 ** Blocks now provide four new attributes. global_block and
3070 static_block will return the global and static blocks
3071 respectively. is_static and is_global are boolean attributes
3072 that indicate if the block is one of those two types.
3074 ** Symbols now provide the "type" attribute, the type of the symbol.
3076 ** The "gdb.breakpoint" function has been deprecated in favor of
3079 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3080 of a function. This class is based on the "finish" command
3081 available in the CLI.
3083 ** Type objects for struct and union types now allow access to
3084 the fields using standard Python dictionary (mapping) methods.
3085 For example, "some_type['myfield']" now works, as does
3086 "some_type.items()".
3088 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3091 ** A new function, "deep_items" has been added to the gdb.types
3092 module in the GDB Python modules library. This function returns
3093 an iterator over the fields of a struct or union type. Unlike
3094 the standard Python "iteritems" method, it will recursively traverse
3095 any anonymous fields.
3099 ** "*stopped" events can report several new "reason"s, such as
3102 ** Breakpoint changes are now notified using new async records, like
3103 "=breakpoint-modified".
3105 ** New command -ada-task-info.
3107 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3108 $sdir specifies the default system locations of shared libraries.
3109 $pdir specifies the directory where the libpthread used by the application
3112 GDB no longer looks in $sdir and $pdir after it has searched the directories
3113 mentioned in libthread-db-search-path. If you want to search those
3114 directories, they must be specified in libthread-db-search-path.
3115 The default value of libthread-db-search-path on GNU/Linux and Solaris
3116 systems is now "$sdir:$pdir".
3118 $pdir is not supported by gdbserver, it is currently ignored.
3119 $sdir is supported by gdbserver.
3121 * New configure option --with-iconv-bin.
3122 When using the internationalization support like the one in the GNU C
3123 library, GDB will invoke the "iconv" program to get a list of supported
3124 character sets. If this program lives in a non-standard location, one can
3125 use this option to specify where to find it.
3127 * When natively debugging programs on PowerPC BookE processors running
3128 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3129 watchpoints, which specify a mask in addition to an address to watch.
3130 The mask specifies that some bits of an address (the bits which are
3131 reset in the mask) should be ignored when matching the address accessed
3132 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3133 section in the user manual for more details.
3135 * The new option --once causes GDBserver to stop listening for connections once
3136 the first connection is made. The listening port used by GDBserver will
3137 become available after that.
3139 * New commands "info macros" and "alias" have been added.
3141 * New function parameters suffix @entry specifies value of function parameter
3142 at the time the function got called. Entry values are available only since
3148 "!" is now an alias of the "shell" command.
3149 Note that no space is needed between "!" and SHELL COMMAND.
3153 watch EXPRESSION mask MASK_VALUE
3154 The watch command now supports the mask argument which allows creation
3155 of masked watchpoints, if the current architecture supports this feature.
3157 info auto-load-scripts [REGEXP]
3158 This command was formerly named "maintenance print section-scripts".
3159 It is now generally useful and is no longer a maintenance-only command.
3161 info macro [-all] [--] MACRO
3162 The info macro command has new options `-all' and `--'. The first for
3163 printing all definitions of a macro. The second for explicitly specifying
3164 the end of arguments and the beginning of the macro name in case the macro
3165 name starts with a hyphen.
3167 collect[/s] EXPRESSIONS
3168 The tracepoint collect command now takes an optional modifier "/s"
3169 that directs it to dereference pointer-to-character types and
3170 collect the bytes of memory up to a zero byte. The behavior is
3171 similar to what you see when you use the regular print command on a
3172 string. An optional integer following the "/s" sets a bound on the
3173 number of bytes that will be collected.
3176 The trace start command now interprets any supplied arguments as a
3177 note to be recorded with the trace run, with an effect similar to
3178 setting the variable trace-notes.
3181 The trace stop command now interprets any arguments as a note to be
3182 mentioned along with the tstatus report that the trace was stopped
3183 with a command. The effect is similar to setting the variable
3186 * Tracepoints can now be enabled and disabled at any time after a trace
3187 experiment has been started using the standard "enable" and "disable"
3188 commands. It is now possible to start a trace experiment with no enabled
3189 tracepoints; GDB will display a warning, but will allow the experiment to
3190 begin, assuming that tracepoints will be enabled as needed while the trace
3193 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3194 locations with 4-byte instructions, when they were previously
3195 limited to locations with instructions of 5 bytes or longer.
3199 set debug dwarf2-read
3200 show debug dwarf2-read
3201 Turns on or off display of debugging messages related to reading
3202 DWARF debug info. The default is off.
3204 set debug symtab-create
3205 show debug symtab-create
3206 Turns on or off display of debugging messages related to symbol table
3207 creation. The default is off.
3210 show extended-prompt
3211 Set the GDB prompt, and allow escape sequences to be inserted to
3212 display miscellaneous information (see 'help set extended-prompt'
3213 for the list of sequences). This prompt (and any information
3214 accessed through the escape sequences) is updated every time the
3215 prompt is displayed.
3217 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3218 show print entry-values
3219 Set printing of frame argument values at function entry. In some cases
3220 GDB can determine the value of function argument which was passed by the
3221 function caller, even if the value was modified inside the called function.
3223 set debug entry-values
3224 show debug entry-values
3225 Control display of debugging info for determining frame argument values at
3226 function entry and virtual tail call frames.
3228 set basenames-may-differ
3229 show basenames-may-differ
3230 Set whether a source file may have multiple base names.
3231 (A "base name" is the name of a file with the directory part removed.
3232 Example: The base name of "/home/user/hello.c" is "hello.c".)
3233 If set, GDB will canonicalize file names (e.g., expand symlinks)
3234 before comparing them. Canonicalization is an expensive operation,
3235 but it allows the same file be known by more than one base name.
3236 If not set (the default), all source files are assumed to have just
3237 one base name, and gdb will do file name comparisons more efficiently.
3243 Set a user name and notes for the current and any future trace runs.
3244 This is useful for long-running and/or disconnected traces, to
3245 inform others (or yourself) as to who is running the trace, supply
3246 contact information, or otherwise explain what is going on.
3248 set trace-stop-notes
3249 show trace-stop-notes
3250 Set a note attached to the trace run, that is displayed when the
3251 trace has been stopped by a tstop command. This is useful for
3252 instance as an explanation, if you are stopping a trace run that was
3253 started by someone else.
3255 * New remote packets
3259 Dynamically enable a tracepoint in a started trace experiment.
3263 Dynamically disable a tracepoint in a started trace experiment.
3267 Set the user and notes of the trace run.
3271 Query the current status of a tracepoint.
3275 Query the minimum length of instruction at which a fast tracepoint may
3278 * Dcache size (number of lines) and line-size are now runtime-configurable
3279 via "set dcache line" and "set dcache line-size" commands.
3283 Texas Instruments TMS320C6x tic6x-*-*
3287 Renesas RL78 rl78-*-elf
3289 *** Changes in GDB 7.3.1
3291 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3293 *** Changes in GDB 7.3
3295 * GDB has a new command: "thread find [REGEXP]".
3296 It finds the thread id whose name, target id, or thread extra info
3297 matches the given regular expression.
3299 * The "catch syscall" command now works on mips*-linux* targets.
3301 * The -data-disassemble MI command now supports modes 2 and 3 for
3302 dumping the instruction opcodes.
3304 * New command line options
3306 -data-directory DIR Specify DIR as the "data-directory".
3307 This is mostly for testing purposes.
3309 * The "maint set python auto-load on|off" command has been renamed to
3310 "set auto-load-scripts on|off".
3312 * GDB has a new command: "set directories".
3313 It is like the "dir" command except that it replaces the
3314 source path list instead of augmenting it.
3316 * GDB now understands thread names.
3318 On GNU/Linux, "info threads" will display the thread name as set by
3319 prctl or pthread_setname_np.
3321 There is also a new command, "thread name", which can be used to
3322 assign a name internally for GDB to display.
3325 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3326 has been integrated into GDB.
3330 ** The function gdb.Write now accepts an optional keyword 'stream'.
3331 This keyword, when provided, will direct the output to either
3332 stdout, stderr, or GDB's logging output.
3334 ** Parameters can now be be sub-classed in Python, and in particular
3335 you may implement the get_set_doc and get_show_doc functions.
3336 This improves how Parameter set/show documentation is processed
3337 and allows for more dynamic content.
3339 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3340 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3341 have an is_valid method.
3343 ** Breakpoints can now be sub-classed in Python, and in particular
3344 you may implement a 'stop' function that is executed each time
3345 the inferior reaches that breakpoint.
3347 ** New function gdb.lookup_global_symbol looks up a global symbol.
3349 ** GDB values in Python are now callable if the value represents a
3350 function. For example, if 'some_value' represents a function that
3351 takes two integer parameters and returns a value, you can call
3352 that function like so:
3354 result = some_value (10,20)
3356 ** Module gdb.types has been added.
3357 It contains a collection of utilities for working with gdb.Types objects:
3358 get_basic_type, has_field, make_enum_dict.
3360 ** Module gdb.printing has been added.
3361 It contains utilities for writing and registering pretty-printers.
3362 New classes: PrettyPrinter, SubPrettyPrinter,
3363 RegexpCollectionPrettyPrinter.
3364 New function: register_pretty_printer.
3366 ** New commands "info pretty-printers", "enable pretty-printer" and
3367 "disable pretty-printer" have been added.
3369 ** gdb.parameter("directories") is now available.
3371 ** New function gdb.newest_frame returns the newest frame in the
3374 ** The gdb.InferiorThread class has a new "name" attribute. This
3375 holds the thread's name.
3377 ** Python Support for Inferior events.
3378 Python scripts can add observers to be notified of events
3379 occurring in the process being debugged.
3380 The following events are currently supported:
3381 - gdb.events.cont Continue event.
3382 - gdb.events.exited Inferior exited event.
3383 - gdb.events.stop Signal received, and Breakpoint hit events.
3387 ** GDB now puts template parameters in scope when debugging in an
3388 instantiation. For example, if you have:
3390 template<int X> int func (void) { return X; }
3392 then if you step into func<5>, "print X" will show "5". This
3393 feature requires proper debuginfo support from the compiler; it
3394 was added to GCC 4.5.
3396 ** The motion commands "next", "finish", "until", and "advance" now
3397 work better when exceptions are thrown. In particular, GDB will
3398 no longer lose control of the inferior; instead, the GDB will
3399 stop the inferior at the point at which the exception is caught.
3400 This functionality requires a change in the exception handling
3401 code that was introduced in GCC 4.5.
3403 * GDB now follows GCC's rules on accessing volatile objects when
3404 reading or writing target state during expression evaluation.
3405 One notable difference to prior behavior is that "print x = 0"
3406 no longer generates a read of x; the value of the assignment is
3407 now always taken directly from the value being assigned.
3409 * GDB now has some support for using labels in the program's source in
3410 linespecs. For instance, you can use "advance label" to continue
3411 execution to a label.
3413 * GDB now has support for reading and writing a new .gdb_index
3414 section. This section holds a fast index of DWARF debugging
3415 information and can be used to greatly speed up GDB startup and
3416 operation. See the documentation for `save gdb-index' for details.
3418 * The "watch" command now accepts an optional "-location" argument.
3419 When used, this causes GDB to watch the memory referred to by the
3420 expression. Such a watchpoint is never deleted due to it going out
3423 * GDB now supports thread debugging of core dumps on GNU/Linux.
3425 GDB now activates thread debugging using the libthread_db library
3426 when debugging GNU/Linux core dumps, similarly to when debugging
3427 live processes. As a result, when debugging a core dump file, GDB
3428 is now able to display pthread_t ids of threads. For example, "info
3429 threads" shows the same output as when debugging the process when it
3430 was live. In earlier releases, you'd see something like this:
3433 * 1 LWP 6780 main () at main.c:10
3435 While now you see this:
3438 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3440 It is also now possible to inspect TLS variables when debugging core
3443 When debugging a core dump generated on a machine other than the one
3444 used to run GDB, you may need to point GDB at the correct
3445 libthread_db library with the "set libthread-db-search-path"
3446 command. See the user manual for more details on this command.
3448 * When natively debugging programs on PowerPC BookE processors running
3449 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3450 which stop execution of the inferior whenever it executes an instruction
3451 at any address within the specified range. See the "PowerPC Embedded"
3452 section in the user manual for more details.
3454 * New features in the GDB remote stub, GDBserver
3456 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3457 and i686 LynxOS (version 5.x).
3459 ** GDBserver is now supported on Blackfin Linux.
3461 * New native configurations
3463 ia64 HP-UX ia64-*-hpux*
3467 Analog Devices, Inc. Blackfin Processor bfin-*
3469 * Ada task switching is now supported on sparc-elf targets when
3470 debugging a program using the Ravenscar Profile. For more information,
3471 see the "Tasking Support when using the Ravenscar Profile" section
3472 in the GDB user manual.
3474 * Guile support was removed.
3476 * New features in the GNU simulator
3478 ** The --map-info flag lists all known core mappings.
3480 ** CFI flashes may be simulated via the "cfi" device.
3482 *** Changes in GDB 7.2
3484 * Shared library support for remote targets by default
3486 When GDB is configured for a generic, non-OS specific target, like
3487 for example, --target=arm-eabi or one of the many *-*-elf targets,
3488 GDB now queries remote stubs for loaded shared libraries using the
3489 `qXfer:libraries:read' packet. Previously, shared library support
3490 was always disabled for such configurations.
3494 ** Argument Dependent Lookup (ADL)
3496 In C++ ADL lookup directs function search to the namespaces of its
3497 arguments even if the namespace has not been imported.
3507 Here the compiler will search for `foo' in the namespace of 'b'
3508 and find A::foo. GDB now supports this. This construct is commonly
3509 used in the Standard Template Library for operators.
3511 ** Improved User Defined Operator Support
3513 In addition to member operators, GDB now supports lookup of operators
3514 defined in a namespace and imported with a `using' directive, operators
3515 defined in the global scope, operators imported implicitly from an
3516 anonymous namespace, and the ADL operators mentioned in the previous
3518 GDB now also supports proper overload resolution for all the previously
3519 mentioned flavors of operators.
3521 ** static const class members
3523 Printing of static const class members that are initialized in the
3524 class definition has been fixed.
3526 * Windows Thread Information Block access.
3528 On Windows targets, GDB now supports displaying the Windows Thread
3529 Information Block (TIB) structure. This structure is visible either
3530 by using the new command `info w32 thread-information-block' or, by
3531 dereferencing the new convenience variable named `$_tlb', a
3532 thread-specific pointer to the TIB. This feature is also supported
3533 when remote debugging using GDBserver.
3535 * Static tracepoints
3537 Static tracepoints are calls in the user program into a tracing
3538 library. One such library is a port of the LTTng kernel tracer to
3539 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3540 When debugging with GDBserver, GDB now supports combining the GDB
3541 tracepoint machinery with such libraries. For example: the user can
3542 use GDB to probe a static tracepoint marker (a call from the user
3543 program into the tracing library) with the new "strace" command (see
3544 "New commands" below). This creates a "static tracepoint" in the
3545 breakpoint list, that can be manipulated with the same feature set
3546 as fast and regular tracepoints. E.g., collect registers, local and
3547 global variables, collect trace state variables, and define
3548 tracepoint conditions. In addition, the user can collect extra
3549 static tracepoint marker specific data, by collecting the new
3550 $_sdata internal variable. When analyzing the trace buffer, you can
3551 inspect $_sdata like any other variable available to GDB. For more
3552 information, see the "Tracepoints" chapter in GDB user manual. New
3553 remote packets have been defined to support static tracepoints, see
3554 the "New remote packets" section below.
3556 * Better reconstruction of tracepoints after disconnected tracing
3558 GDB will attempt to download the original source form of tracepoint
3559 definitions when starting a trace run, and then will upload these
3560 upon reconnection to the target, resulting in a more accurate
3561 reconstruction of the tracepoints that are in use on the target.
3565 You can now exercise direct control over the ways that GDB can
3566 affect your program. For instance, you can disallow the setting of
3567 breakpoints, so that the program can run continuously (assuming
3568 non-stop mode). In addition, the "observer" variable is available
3569 to switch all of the different controls; in observer mode, GDB
3570 cannot affect the target's behavior at all, which is useful for
3571 tasks like diagnosing live systems in the field.
3573 * The new convenience variable $_thread holds the number of the
3576 * New remote packets
3580 Return the address of the Windows Thread Information Block of a given thread.
3584 In response to several of the tracepoint packets, the target may now
3585 also respond with a number of intermediate `qRelocInsn' request
3586 packets before the final result packet, to have GDB handle
3587 relocating an instruction to execute at a different address. This
3588 is particularly useful for stubs that support fast tracepoints. GDB
3589 reports support for this feature in the qSupported packet.
3593 List static tracepoint markers in the target program.
3597 List static tracepoint markers at a given address in the target
3600 qXfer:statictrace:read
3602 Read the static trace data collected (by a `collect $_sdata'
3603 tracepoint action). The remote stub reports support for this packet
3604 to gdb's qSupported query.
3608 Send the current settings of GDB's permission flags.
3612 Send part of the source (textual) form of a tracepoint definition,
3613 which includes location, conditional, and action list.
3615 * The source command now accepts a -s option to force searching for the
3616 script in the source search path even if the script name specifies
3619 * New features in the GDB remote stub, GDBserver
3621 - GDBserver now support tracepoints (including fast tracepoints, and
3622 static tracepoints). The feature is currently supported by the
3623 i386-linux and amd64-linux builds. See the "Tracepoints support
3624 in gdbserver" section in the manual for more information.
3626 GDBserver JIT compiles the tracepoint's conditional agent
3627 expression bytecode into native code whenever possible for low
3628 overhead dynamic tracepoints conditionals. For such tracepoints,
3629 an expression that examines program state is evaluated when the
3630 tracepoint is reached, in order to determine whether to capture
3631 trace data. If the condition is simple and false, processing the
3632 tracepoint finishes very quickly and no data is gathered.
3634 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3635 for static tracepoints support.
3637 - GDBserver now supports x86_64 Windows 64-bit debugging.
3639 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3640 it understands register description.
3642 * The --batch flag now disables pagination and queries.
3644 * X86 general purpose registers
3646 GDB now supports reading/writing byte, word and double-word x86
3647 general purpose registers directly. This means you can use, say,
3648 $ah or $ax to refer, respectively, to the byte register AH and
3649 16-bit word register AX that are actually portions of the 32-bit
3650 register EAX or 64-bit register RAX.
3652 * The `commands' command now accepts a range of breakpoints to modify.
3653 A plain `commands' following a command that creates multiple
3654 breakpoints affects all the breakpoints set by that command. This
3655 applies to breakpoints set by `rbreak', and also applies when a
3656 single `break' command creates multiple breakpoints (e.g.,
3657 breakpoints on overloaded c++ functions).
3659 * The `rbreak' command now accepts a filename specification as part of
3660 its argument, limiting the functions selected by the regex to those
3661 in the specified file.
3663 * Support for remote debugging Windows and SymbianOS shared libraries
3664 from Unix hosts has been improved. Non Windows GDB builds now can
3665 understand target reported file names that follow MS-DOS based file
3666 system semantics, such as file names that include drive letters and
3667 use the backslash character as directory separator. This makes it
3668 possible to transparently use the "set sysroot" and "set
3669 solib-search-path" on Unix hosts to point as host copies of the
3670 target's shared libraries. See the new command "set
3671 target-file-system-kind" described below, and the "Commands to
3672 specify files" section in the user manual for more information.
3676 eval template, expressions...
3677 Convert the values of one or more expressions under the control
3678 of the string template to a command line, and call it.
3680 set target-file-system-kind unix|dos-based|auto
3681 show target-file-system-kind
3682 Set or show the assumed file system kind for target reported file
3685 save breakpoints <filename>
3686 Save all current breakpoint definitions to a file suitable for use
3687 in a later debugging session. To read the saved breakpoint
3688 definitions, use the `source' command.
3690 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3693 info static-tracepoint-markers
3694 Display information about static tracepoint markers in the target.
3696 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3697 Define a static tracepoint by probing a marker at the given
3698 function, line, address, or marker ID.
3702 Enable and disable observer mode.
3704 set may-write-registers on|off
3705 set may-write-memory on|off
3706 set may-insert-breakpoints on|off
3707 set may-insert-tracepoints on|off
3708 set may-insert-fast-tracepoints on|off
3709 set may-interrupt on|off
3710 Set individual permissions for GDB effects on the target. Note that
3711 some of these settings can have undesirable or surprising
3712 consequences, particularly when changed in the middle of a session.
3713 For instance, disabling the writing of memory can prevent
3714 breakpoints from being inserted, cause single-stepping to fail, or
3715 even crash your program, if you disable after breakpoints have been
3716 inserted. However, GDB should not crash.
3718 set record memory-query on|off
3719 show record memory-query
3720 Control whether to stop the inferior if memory changes caused
3721 by an instruction cannot be recorded.
3726 The disassemble command now supports "start,+length" form of two arguments.
3730 ** GDB now provides a new directory location, called the python directory,
3731 where Python scripts written for GDB can be installed. The location
3732 of that directory is <data-directory>/python, where <data-directory>
3733 is the GDB data directory. For more details, see section `Scripting
3734 GDB using Python' in the manual.
3736 ** The GDB Python API now has access to breakpoints, symbols, symbol
3737 tables, program spaces, inferiors, threads and frame's code blocks.
3738 Additionally, GDB Parameters can now be created from the API, and
3739 manipulated via set/show in the CLI.
3741 ** New functions gdb.target_charset, gdb.target_wide_charset,
3742 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3744 ** New exception gdb.GdbError.
3746 ** Pretty-printers are now also looked up in the current program space.
3748 ** Pretty-printers can now be individually enabled and disabled.
3750 ** GDB now looks for names of Python scripts to auto-load in a
3751 special section named `.debug_gdb_scripts', in addition to looking
3752 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3754 * Tracepoint actions were unified with breakpoint commands. In particular,
3755 there are no longer differences in "info break" output for breakpoints and
3756 tracepoints and the "commands" command can be used for both tracepoints and
3757 regular breakpoints.
3761 ARM Symbian arm*-*-symbianelf*
3763 * D language support.
3764 GDB now supports debugging programs written in the D programming
3767 * GDB now supports the extended ptrace interface for PowerPC which is
3768 available since Linux kernel version 2.6.34. This automatically enables
3769 any hardware breakpoints and additional hardware watchpoints available in
3770 the processor. The old ptrace interface exposes just one hardware
3771 watchpoint and no hardware breakpoints.
3773 * GDB is now able to use the Data Value Compare (DVC) register available on
3774 embedded PowerPC processors to implement in hardware simple watchpoint
3775 conditions of the form:
3777 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3779 This works in native GDB running on Linux kernels with the extended ptrace
3780 interface mentioned above.
3782 *** Changes in GDB 7.1
3786 ** Namespace Support
3788 GDB now supports importing of namespaces in C++. This enables the
3789 user to inspect variables from imported namespaces. Support for
3790 namepace aliasing has also been added. So, if a namespace is
3791 aliased in the current scope (e.g. namepace C=A; ) the user can
3792 print variables using the alias (e.g. (gdb) print C::x).
3796 All known bugs relating to the printing of virtual base class were
3797 fixed. It is now possible to call overloaded static methods using a
3802 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3803 and reinterpret_cast<> are now handled by the C++ expression parser.
3807 Xilinx MicroBlaze microblaze-*-*
3812 Xilinx MicroBlaze microblaze
3815 * Multi-program debugging.
3817 GDB now has support for multi-program (a.k.a. multi-executable or
3818 multi-exec) debugging. This allows for debugging multiple inferiors
3819 simultaneously each running a different program under the same GDB
3820 session. See "Debugging Multiple Inferiors and Programs" in the
3821 manual for more information. This implied some user visible changes
3822 in the multi-inferior support. For example, "info inferiors" now
3823 lists inferiors that are not running yet or that have exited
3824 already. See also "New commands" and "New options" below.
3826 * New tracing features
3828 GDB's tracepoint facility now includes several new features:
3830 ** Trace state variables
3832 GDB tracepoints now include support for trace state variables, which
3833 are variables managed by the target agent during a tracing
3834 experiment. They are useful for tracepoints that trigger each
3835 other, so for instance one tracepoint can count hits in a variable,
3836 and then a second tracepoint has a condition that is true when the
3837 count reaches a particular value. Trace state variables share the
3838 $-syntax of GDB convenience variables, and can appear in both
3839 tracepoint actions and condition expressions. Use the "tvariable"
3840 command to create, and "info tvariables" to view; see "Trace State
3841 Variables" in the manual for more detail.
3845 GDB now includes an option for defining fast tracepoints, which
3846 targets may implement more efficiently, such as by installing a jump
3847 into the target agent rather than a trap instruction. The resulting
3848 speedup can be by two orders of magnitude or more, although the
3849 tradeoff is that some program locations on some target architectures
3850 might not allow fast tracepoint installation, for instance if the
3851 instruction to be replaced is shorter than the jump. To request a
3852 fast tracepoint, use the "ftrace" command, with syntax identical to
3853 the regular trace command.
3855 ** Disconnected tracing
3857 It is now possible to detach GDB from the target while it is running
3858 a trace experiment, then reconnect later to see how the experiment
3859 is going. In addition, a new variable disconnected-tracing lets you
3860 tell the target agent whether to continue running a trace if the
3861 connection is lost unexpectedly.
3865 GDB now has the ability to save the trace buffer into a file, and
3866 then use that file as a target, similarly to you can do with
3867 corefiles. You can select trace frames, print data that was
3868 collected in them, and use tstatus to display the state of the
3869 tracing run at the moment that it was saved. To create a trace
3870 file, use "tsave <filename>", and to use it, do "target tfile
3873 ** Circular trace buffer
3875 You can ask the target agent to handle the trace buffer as a
3876 circular buffer, discarding the oldest trace frames to make room for
3877 newer ones, by setting circular-trace-buffer to on. This feature may
3878 not be available for all target agents.
3883 The disassemble command, when invoked with two arguments, now requires
3884 the arguments to be comma-separated.
3887 The info variables command now displays variable definitions. Files
3888 which only declare a variable are not shown.
3891 The source command is now capable of sourcing Python scripts.
3892 This feature is dependent on the debugger being build with Python
3895 Related to this enhancement is also the introduction of a new command
3896 "set script-extension" (see below).
3898 * New commands (for set/show, see "New options" below)
3900 record save [<FILENAME>]
3901 Save a file (in core file format) containing the process record
3902 execution log for replay debugging at a later time.
3904 record restore <FILENAME>
3905 Restore the process record execution log that was saved at an
3906 earlier time, for replay debugging.
3908 add-inferior [-copies <N>] [-exec <FILENAME>]
3911 clone-inferior [-copies <N>] [ID]
3912 Make a new inferior ready to execute the same program another
3913 inferior has loaded.
3918 maint info program-spaces
3919 List the program spaces loaded into GDB.
3921 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3922 show remote interrupt-sequence
3923 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3924 as the sequence to the remote target in order to interrupt the execution.
3925 Ctrl-C is a default. Some system prefers BREAK which is high level of
3926 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3927 Magic SysRq g. It is BREAK signal and character 'g'.
3929 set remote interrupt-on-connect [on | off]
3930 show remote interrupt-on-connect
3931 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3932 remote target when gdb connects to it. This is needed when you debug
3935 set remotebreak [on | off]
3937 Deprecated. Use "set/show remote interrupt-sequence" instead.
3939 tvariable $NAME [ = EXP ]
3940 Create or modify a trace state variable.
3943 List trace state variables and their values.
3945 delete tvariable $NAME ...
3946 Delete one or more trace state variables.
3949 Evaluate the given expressions without collecting anything into the
3950 trace buffer. (Valid in tracepoint actions only.)
3952 ftrace FN / FILE:LINE / *ADDR
3953 Define a fast tracepoint at the given function, line, or address.
3955 * New expression syntax
3957 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3958 GDB now parses 0b101010 identically with 42.
3962 set follow-exec-mode new|same
3963 show follow-exec-mode
3964 Control whether GDB reuses the same inferior across an exec call or
3965 creates a new one. This is useful to be able to restart the old
3966 executable after the inferior having done an exec call.
3968 set default-collect EXPR, ...
3969 show default-collect
3970 Define a list of expressions to be collected at each tracepoint.
3971 This is a useful way to ensure essential items are not overlooked,
3972 such as registers or a critical global variable.
3974 set disconnected-tracing
3975 show disconnected-tracing
3976 If set to 1, the target is instructed to continue tracing if it
3977 loses its connection to GDB. If 0, the target is to stop tracing
3980 set circular-trace-buffer
3981 show circular-trace-buffer
3982 If set to on, the target is instructed to use a circular trace buffer
3983 and discard the oldest trace frames instead of stopping the trace due
3984 to a full trace buffer. If set to off, the trace stops when the buffer
3985 fills up. Some targets may not support this.
3987 set script-extension off|soft|strict
3988 show script-extension
3989 If set to "off", the debugger does not perform any script language
3990 recognition, and all sourced files are assumed to be GDB scripts.
3991 If set to "soft" (the default), files are sourced according to
3992 filename extension, falling back to GDB scripts if the first
3994 If set to "strict", files are sourced according to filename extension.
3996 set ada trust-PAD-over-XVS on|off
3997 show ada trust-PAD-over-XVS
3998 If off, activate a workaround against a bug in the debugging information
3999 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4000 the GCC sources for more information about the GNAT encoding and
4001 PAD types in particular). It is always safe to set this option to
4002 off, but this introduces a slight performance penalty. The default
4005 * Python API Improvements
4007 ** GDB provides the new class gdb.LazyString. This is useful in
4008 some pretty-printing cases. The new method gdb.Value.lazy_string
4009 provides a simple way to create objects of this type.
4011 ** The fields returned by gdb.Type.fields now have an
4012 `is_base_class' attribute.
4014 ** The new method gdb.Type.range returns the range of an array type.
4016 ** The new method gdb.parse_and_eval can be used to parse and
4017 evaluate an expression.
4019 * New remote packets
4022 Define a trace state variable.
4025 Get the current value of a trace state variable.
4028 Set desired tracing behavior upon disconnection.
4031 Set the trace buffer to be linear or circular.
4034 Get data about the tracepoints currently in use.
4038 Process record now works correctly with hardware watchpoints.
4040 Multiple bug fixes have been made to the mips-irix port, making it
4041 much more reliable. In particular:
4042 - Debugging threaded applications is now possible again. Previously,
4043 GDB would hang while starting the program, or while waiting for
4044 the program to stop at a breakpoint.
4045 - Attaching to a running process no longer hangs.
4046 - An error occurring while loading a core file has been fixed.
4047 - Changing the value of the PC register now works again. This fixes
4048 problems observed when using the "jump" command, or when calling
4049 a function from GDB, or even when assigning a new value to $pc.
4050 - With the "finish" and "return" commands, the return value for functions
4051 returning a small array is now correctly printed.
4052 - It is now possible to break on shared library code which gets executed
4053 during a shared library init phase (code executed while executing
4054 their .init section). Previously, the breakpoint would have no effect.
4055 - GDB is now able to backtrace through the signal handler for
4056 non-threaded programs.
4058 PIE (Position Independent Executable) programs debugging is now supported.
4059 This includes debugging execution of PIC (Position Independent Code) shared
4060 libraries although for that, it should be possible to run such libraries as an
4063 *** Changes in GDB 7.0
4065 * GDB now has an interface for JIT compilation. Applications that
4066 dynamically generate code can create symbol files in memory and register
4067 them with GDB. For users, the feature should work transparently, and
4068 for JIT developers, the interface is documented in the GDB manual in the
4069 "JIT Compilation Interface" chapter.
4071 * Tracepoints may now be conditional. The syntax is as for
4072 breakpoints; either an "if" clause appended to the "trace" command,
4073 or the "condition" command is available. GDB sends the condition to
4074 the target for evaluation using the same bytecode format as is used
4075 for tracepoint actions.
4077 * The disassemble command now supports: an optional /r modifier, print the
4078 raw instructions in hex as well as in symbolic form, and an optional /m
4079 modifier to print mixed source+assembly.
4081 * Process record and replay
4083 In a architecture environment that supports ``process record and
4084 replay'', ``process record and replay'' target can record a log of
4085 the process execution, and replay it with both forward and reverse
4088 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4089 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4090 set execution-direction {forward|reverse}, for targets that support
4093 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4094 feature is available with a native GDB running on kernel version
4097 * GDB now has support for multi-byte and wide character sets on the
4098 target. Strings whose character type is wchar_t, char16_t, or
4099 char32_t are now correctly printed. GDB supports wide- and unicode-
4100 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4101 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4102 `printf'. This feature requires iconv to work properly; if your
4103 system does not have a working iconv, GDB can use GNU libiconv. See
4104 the installation instructions for more information.
4106 * GDB now supports automatic retrieval of shared library files from
4107 remote targets. To use this feature, specify a system root that begins
4108 with the `remote:' prefix, either via the `set sysroot' command or via
4109 the `--with-sysroot' configure-time option.
4111 * "info sharedlibrary" now takes an optional regex of libraries to show,
4112 and it now reports if a shared library has no debugging information.
4114 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4115 now complete on file names.
4117 * When completing in expressions, gdb will attempt to limit
4118 completions to allowable structure or union fields, where appropriate.
4119 For instance, consider:
4121 # struct example { int f1; double f2; };
4122 # struct example variable;
4125 If the user types TAB at the end of this command line, the available
4126 completions will be "f1" and "f2".
4128 * Inlined functions are now supported. They show up in backtraces, and
4129 the "step", "next", and "finish" commands handle them automatically.
4131 * GDB now supports the token-splicing (##) and stringification (#)
4132 operators when expanding macros. It also supports variable-arity
4135 * GDB now supports inspecting extra signal information, exported by
4136 the new $_siginfo convenience variable. The feature is currently
4137 implemented on linux ARM, i386 and amd64.
4139 * GDB can now display the VFP floating point registers and NEON vector
4140 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4141 can provide these registers (requires Linux 2.6.30 or later). Remote
4142 and simulator targets may also provide them.
4144 * New remote packets
4147 Search memory for a sequence of bytes.
4150 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4151 operation over reliable transport links. Use of this packet is
4152 controlled by the `set remote noack-packet' command.
4155 Kill the process with the specified process ID. Use this in preference
4156 to `k' when multiprocess protocol extensions are supported.
4159 Obtains additional operating system information
4163 Read or write additional signal information.
4165 * Removed remote protocol undocumented extension
4167 An undocumented extension to the remote protocol's `S' stop reply
4168 packet that permited the stub to pass a process id was removed.
4169 Remote servers should use the `T' stop reply packet instead.
4171 * GDB now supports multiple function calling conventions according to the
4172 DWARF-2 DW_AT_calling_convention function attribute.
4174 * The SH target utilizes the aforementioned change to distinguish between gcc
4175 and Renesas calling convention. It also adds the new CLI commands
4176 `set/show sh calling-convention'.
4178 * GDB can now read compressed debug sections, as produced by GNU gold
4179 with the --compress-debug-sections=zlib flag.
4181 * 64-bit core files are now supported on AIX.
4183 * Thread switching is now supported on Tru64.
4185 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4186 which will be allocated using malloc later in program execution.
4188 * The qXfer:libraries:read remote procotol packet now allows passing a
4189 list of section offsets.
4191 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4192 conditions handling signals delivered during attach or thread creation
4193 have also been fixed.
4195 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4196 From the user's standpoint, all unqualified instances of True and False
4197 are treated as the standard definitions, regardless of context.
4199 * GDB now parses C++ symbol and type names more flexibly. For
4202 template<typename T> class C { };
4205 GDB will now correctly handle all of:
4207 ptype C<char const *>
4208 ptype C<char const*>
4209 ptype C<const char *>
4210 ptype C<const char*>
4212 * New features in the GDB remote stub, gdbserver
4214 - The "--wrapper" command-line argument tells gdbserver to use a
4215 wrapper program to launch programs for debugging.
4217 - On PowerPC and S/390 targets, it is now possible to use a single
4218 gdbserver executable to debug both 32-bit and 64-bit programs.
4219 (This requires gdbserver itself to be built as a 64-bit executable.)
4221 - gdbserver uses the new noack protocol mode for TCP connections to
4222 reduce communications latency, if also supported and enabled in GDB.
4224 - Support for the sparc64-linux-gnu target is now included in
4227 - The amd64-linux build of gdbserver now supports debugging both
4228 32-bit and 64-bit programs.
4230 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4231 now support hardware watchpoints, and will use them automatically
4236 GDB now has support for scripting using Python. Whether this is
4237 available is determined at configure time.
4239 New GDB commands can now be written in Python.
4241 * Ada tasking support
4243 Ada tasks can now be inspected in GDB. The following commands have
4247 Print the list of Ada tasks.
4249 Print detailed information about task number N.
4251 Print the task number of the current task.
4253 Switch the context of debugging to task number N.
4255 * Support for user-defined prefixed commands. The "define" command can
4256 add new commands to existing prefixes, e.g. "target".
4258 * Multi-inferior, multi-process debugging.
4260 GDB now has generalized support for multi-inferior debugging. See
4261 "Debugging Multiple Inferiors" in the manual for more information.
4262 Although availability still depends on target support, the command
4263 set is more uniform now. The GNU/Linux specific multi-forks support
4264 has been migrated to this new framework. This implied some user
4265 visible changes; see "New commands" and also "Removed commands"
4268 * Target descriptions can now describe the target OS ABI. See the
4269 "Target Description Format" section in the user manual for more
4272 * Target descriptions can now describe "compatible" architectures
4273 to indicate that the target can execute applications for a different
4274 architecture in addition to those for the main target architecture.
4275 See the "Target Description Format" section in the user manual for
4278 * Multi-architecture debugging.
4280 GDB now includes general supports for debugging applications on
4281 hybrid systems that use more than one single processor architecture
4282 at the same time. Each such hybrid architecture still requires
4283 specific support to be added. The only hybrid architecture supported
4284 in this version of GDB is the Cell Broadband Engine.
4286 * GDB now supports integrated debugging of Cell/B.E. applications that
4287 use both the PPU and SPU architectures. To enable support for hybrid
4288 Cell/B.E. debugging, you need to configure GDB to support both the
4289 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4290 --enable-targets configure option.
4292 * Non-stop mode debugging.
4294 For some targets, GDB now supports an optional mode of operation in
4295 which you can examine stopped threads while other threads continue
4296 to execute freely. This is referred to as non-stop mode, with the
4297 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4298 section in the user manual for more information.
4300 To be able to support remote non-stop debugging, a remote stub needs
4301 to implement the non-stop mode remote protocol extensions, as
4302 described in the "Remote Non-Stop" section of the user manual. The
4303 GDB remote stub, gdbserver, has been adjusted to support these
4304 extensions on linux targets.
4306 * New commands (for set/show, see "New options" below)
4308 catch syscall [NAME(S) | NUMBER(S)]
4309 Catch system calls. Arguments, which should be names of system
4310 calls or their numbers, mean catch only those syscalls. Without
4311 arguments, every syscall will be caught. When the inferior issues
4312 any of the specified syscalls, GDB will stop and announce the system
4313 call, both when it is called and when its call returns. This
4314 feature is currently available with a native GDB running on the
4315 Linux Kernel, under the following architectures: x86, x86_64,
4316 PowerPC and PowerPC64.
4318 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4320 Search memory for a sequence of bytes.
4322 maint set python print-stack
4323 maint show python print-stack
4324 Show a stack trace when an error is encountered in a Python script.
4327 Invoke CODE by passing it to the Python interpreter.
4332 These allow macros to be defined, undefined, and listed
4336 Show operating system information about processes.
4339 List the inferiors currently under GDB's control.
4342 Switch focus to inferior number NUM.
4345 Detach from inferior number NUM.
4348 Kill inferior number NUM.
4352 set spu stop-on-load
4353 show spu stop-on-load
4354 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4356 set spu auto-flush-cache
4357 show spu auto-flush-cache
4358 Control whether to automatically flush the software-managed cache
4359 during Cell/B.E. debugging.
4361 set sh calling-convention
4362 show sh calling-convention
4363 Control the calling convention used when calling SH target functions.
4366 show debug timestamp
4367 Control display of timestamps with GDB debugging output.
4369 set disassemble-next-line
4370 show disassemble-next-line
4371 Control display of disassembled source lines or instructions when
4374 set remote noack-packet
4375 show remote noack-packet
4376 Set/show the use of remote protocol QStartNoAckMode packet. See above
4377 under "New remote packets."
4379 set remote query-attached-packet
4380 show remote query-attached-packet
4381 Control use of remote protocol `qAttached' (query-attached) packet.
4383 set remote read-siginfo-object
4384 show remote read-siginfo-object
4385 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4388 set remote write-siginfo-object
4389 show remote write-siginfo-object
4390 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4393 set remote reverse-continue
4394 show remote reverse-continue
4395 Control use of remote protocol 'bc' (reverse-continue) packet.
4397 set remote reverse-step
4398 show remote reverse-step
4399 Control use of remote protocol 'bs' (reverse-step) packet.
4401 set displaced-stepping
4402 show displaced-stepping
4403 Control displaced stepping mode. Displaced stepping is a way to
4404 single-step over breakpoints without removing them from the debuggee.
4405 Also known as "out-of-line single-stepping".
4408 show debug displaced
4409 Control display of debugging info for displaced stepping.
4411 maint set internal-error
4412 maint show internal-error
4413 Control what GDB does when an internal error is detected.
4415 maint set internal-warning
4416 maint show internal-warning
4417 Control what GDB does when an internal warning is detected.
4422 Use a wrapper program to launch programs for debugging.
4424 set multiple-symbols (all|ask|cancel)
4425 show multiple-symbols
4426 The value of this variable can be changed to adjust the debugger behavior
4427 when an expression or a breakpoint location contains an ambiguous symbol
4428 name (an overloaded function name, for instance).
4430 set breakpoint always-inserted
4431 show breakpoint always-inserted
4432 Keep breakpoints always inserted in the target, as opposed to inserting
4433 them when resuming the target, and removing them when the target stops.
4434 This option can improve debugger performance on slow remote targets.
4436 set arm fallback-mode (arm|thumb|auto)
4437 show arm fallback-mode
4438 set arm force-mode (arm|thumb|auto)
4440 These commands control how ARM GDB determines whether instructions
4441 are ARM or Thumb. The default for both settings is auto, which uses
4442 the current CPSR value for instructions without symbols; previous
4443 versions of GDB behaved as if "set arm fallback-mode arm".
4445 set disable-randomization
4446 show disable-randomization
4447 Standalone programs run with the virtual address space randomization enabled
4448 by default on some platforms. This option keeps the addresses stable across
4449 multiple debugging sessions.
4453 Control whether other threads are stopped or not when some thread hits
4458 Requests that asynchronous execution is enabled in the target, if available.
4459 In this case, it's possible to resume target in the background, and interact
4460 with GDB while the target is running. "show target-async" displays the
4461 current state of asynchronous execution of the target.
4463 set target-wide-charset
4464 show target-wide-charset
4465 The target-wide-charset is the name of the character set that GDB
4466 uses when printing characters whose type is wchar_t.
4468 set tcp auto-retry (on|off)
4470 set tcp connect-timeout
4471 show tcp connect-timeout
4472 These commands allow GDB to retry failed TCP connections to a remote stub
4473 with a specified timeout period; this is useful if the stub is launched
4474 in parallel with GDB but may not be ready to accept connections immediately.
4476 set libthread-db-search-path
4477 show libthread-db-search-path
4478 Control list of directories which GDB will search for appropriate
4481 set schedule-multiple (on|off)
4482 show schedule-multiple
4483 Allow GDB to resume all threads of all processes or only threads of
4484 the current process.
4488 Use more aggressive caching for accesses to the stack. This improves
4489 performance of remote debugging (particularly backtraces) without
4490 affecting correctness.
4492 set interactive-mode (on|off|auto)
4493 show interactive-mode
4494 Control whether GDB runs in interactive mode (on) or not (off).
4495 When in interactive mode, GDB waits for the user to answer all
4496 queries. Otherwise, GDB does not wait and assumes the default
4497 answer. When set to auto (the default), GDB determines which
4498 mode to use based on the stdin settings.
4503 For program forks, this is replaced by the new more generic `info
4504 inferiors' command. To list checkpoints, you can still use the
4505 `info checkpoints' command, which was an alias for the `info forks'
4509 Replaced by the new `inferior' command. To switch between
4510 checkpoints, you can still use the `restart' command, which was an
4511 alias for the `fork' command.
4514 This is removed, since some targets don't have a notion of
4515 processes. To switch between processes, you can still use the
4516 `inferior' command using GDB's own inferior number.
4519 For program forks, this is replaced by the new more generic `kill
4520 inferior' command. To delete a checkpoint, you can still use the
4521 `delete checkpoint' command, which was an alias for the `delete
4525 For program forks, this is replaced by the new more generic `detach
4526 inferior' command. To detach a checkpoint, you can still use the
4527 `detach checkpoint' command, which was an alias for the `detach
4530 * New native configurations
4532 x86/x86_64 Darwin i[34567]86-*-darwin*
4534 x86_64 MinGW x86_64-*-mingw*
4538 Lattice Mico32 lm32-*
4539 x86 DICOS i[34567]86-*-dicos*
4540 x86_64 DICOS x86_64-*-dicos*
4543 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4544 (mingw32ce) debugging.
4550 These commands were actually not implemented on any target.
4552 *** Changes in GDB 6.8
4554 * New native configurations
4556 NetBSD/hppa hppa*-*netbsd*
4557 Xtensa GNU/Linux xtensa*-*-linux*
4561 NetBSD/hppa hppa*-*-netbsd*
4562 Xtensa GNU/Lunux xtensa*-*-linux*
4564 * Change in command line behavior -- corefiles vs. process ids.
4566 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4567 attaching to process NUMBER fails, GDB no longer attempts to open a
4568 core file named NUMBER. Attaching to a program using the -c option
4569 is no longer supported. Instead, use the '-p' or '--pid' options.
4571 * GDB can now be built as a native debugger for debugging Windows x86
4572 (mingw32) Portable Executable (PE) programs.
4574 * Pending breakpoints no longer change their number when their address
4577 * GDB now supports breakpoints with multiple locations,
4578 including breakpoints on C++ constructors, inside C++ templates,
4579 and in inlined functions.
4581 * GDB's ability to debug optimized code has been improved. GDB more
4582 accurately identifies function bodies and lexical blocks that occupy
4583 more than one contiguous range of addresses.
4585 * Target descriptions can now describe registers for PowerPC.
4587 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4588 registers on PowerPC targets.
4590 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4591 targets even when the libthread_db library is not available.
4593 * The GDB remote stub, gdbserver, now supports the new file transfer
4594 commands (remote put, remote get, and remote delete).
4596 * The GDB remote stub, gdbserver, now supports run and attach in
4597 extended-remote mode.
4599 * hppa*64*-*-hpux11* target broken
4600 The debugger is unable to start a program and fails with the following
4601 error: "Error trying to get information about dynamic linker".
4602 The gdb-6.7 release is also affected.
4604 * GDB now supports the --enable-targets= configure option to allow
4605 building a single GDB executable that supports multiple remote
4606 target architectures.
4608 * GDB now supports debugging C and C++ programs which use the
4609 Decimal Floating Point extension. In addition, the PowerPC target
4610 now has a set of pseudo-registers to inspect decimal float values
4611 stored in two consecutive float registers.
4613 * The -break-insert MI command can optionally create pending
4616 * Improved support for debugging Ada
4617 Many improvements to the Ada language support have been made. These
4619 - Better support for Ada2005 interface types
4620 - Improved handling of arrays and slices in general
4621 - Better support for Taft-amendment types
4622 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4624 - Improved command completion in Ada
4627 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4632 set print frame-arguments (all|scalars|none)
4633 show print frame-arguments
4634 The value of this variable can be changed to control which argument
4635 values should be printed by the debugger when displaying a frame.
4640 Transfer files to and from a remote target, and delete remote files.
4647 Transfer files to and from a remote target, and delete remote files.
4649 * New remote packets
4656 Open, close, read, write, and delete files on the remote system.
4659 Attach to an existing process on the remote system, in extended-remote
4663 Run a new process on the remote system, in extended-remote mode.
4665 *** Changes in GDB 6.7
4667 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4668 bfd, libiberty and opcodes, as revealed by static analysis donated by
4669 Coverity, Inc. (http://scan.coverity.com).
4671 * When looking up multiply-defined global symbols, GDB will now prefer the
4672 symbol definition in the current shared library if it was built using the
4673 -Bsymbolic linker option.
4675 * When the Text User Interface (TUI) is not configured, GDB will now
4676 recognize the -tui command-line option and print a message that the TUI
4679 * The GDB remote stub, gdbserver, now has lower overhead for high
4680 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4682 * GDB for MIPS targets now autodetects whether a remote target provides
4683 32-bit or 64-bit register values.
4685 * Support for C++ member pointers has been improved.
4687 * GDB now understands XML target descriptions, which specify the
4688 target's overall architecture. GDB can read a description from
4689 a local file or over the remote serial protocol.
4691 * Vectors of single-byte data use a new integer type which is not
4692 automatically displayed as character or string data.
4694 * The /s format now works with the print command. It displays
4695 arrays of single-byte integers and pointers to single-byte integers
4698 * Target descriptions can now describe target-specific registers,
4699 for architectures which have implemented the support (currently
4700 only ARM, M68K, and MIPS).
4702 * GDB and the GDB remote stub, gdbserver, now support the XScale
4705 * The GDB remote stub, gdbserver, has been updated to support
4706 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4707 has been rewritten to use the standard GDB remote protocol.
4709 * GDB can now step into C++ functions which are called through thunks.
4711 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4713 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4714 layout. It also supports a TextSeg= and DataSeg= response when only
4715 segment base addresses (rather than offsets) are available.
4717 * The /i format now outputs any trailing branch delay slot instructions
4718 immediately following the last instruction within the count specified.
4720 * The GDB remote protocol "T" stop reply packet now supports a
4721 "library" response. Combined with the new "qXfer:libraries:read"
4722 packet, this response allows GDB to debug shared libraries on targets
4723 where the operating system manages the list of loaded libraries (e.g.
4724 Windows and SymbianOS).
4726 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4727 (DLLs) on Windows and Windows CE targets.
4729 * GDB now supports a faster verification that a .debug file matches its binary
4730 according to its build-id signature, if the signature is present.
4736 Enable or disable hardware flow control (RTS/CTS) on the serial port
4737 when debugging using remote targets.
4739 set mem inaccessible-by-default
4740 show mem inaccessible-by-default
4741 If the target supplies a memory map, for instance via the remote
4742 protocol's "qXfer:memory-map:read" packet, setting this variable
4743 prevents GDB from accessing memory outside the memory map. This
4744 is useful for targets with memory mapped registers or which react
4745 badly to accesses of unmapped address space.
4747 set breakpoint auto-hw
4748 show breakpoint auto-hw
4749 If the target supplies a memory map, for instance via the remote
4750 protocol's "qXfer:memory-map:read" packet, setting this variable
4751 lets GDB use hardware breakpoints automatically for memory regions
4752 where it can not use software breakpoints. This covers both the
4753 "break" command and internal breakpoints used for other commands
4754 including "next" and "finish".
4757 catch exception unhandled
4758 Stop the program execution when Ada exceptions are raised.
4761 Stop the program execution when an Ada assertion failed.
4765 Set an alternate system root for target files. This is a more
4766 general version of "set solib-absolute-prefix", which is now
4767 an alias to "set sysroot".
4770 Provide extended SPU facility status information. This set of
4771 commands is available only when debugging the Cell/B.E. SPU
4774 * New native configurations
4776 OpenBSD/sh sh*-*openbsd*
4779 unset tdesc filename
4781 Use the specified local file as an XML target description, and do
4782 not query the target for its built-in description.
4786 OpenBSD/sh sh*-*-openbsd*
4787 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4788 Toshiba Media Processor mep-elf
4790 * New remote packets
4793 Ignore the specified signals; pass them directly to the debugged program
4794 without stopping other threads or reporting them to GDB.
4796 qXfer:features:read:
4797 Read an XML target description from the target, which describes its
4802 Read or write contents of an spufs file on the target system. These
4803 packets are available only on the Cell/B.E. SPU architecture.
4805 qXfer:libraries:read:
4806 Report the loaded shared libraries. Combined with new "T" packet
4807 response, this packet allows GDB to debug shared libraries on
4808 targets where the operating system manages the list of loaded
4809 libraries (e.g. Windows and SymbianOS).
4813 Support for these obsolete configurations has been removed.
4821 i[34567]86-*-lynxos*
4822 i[34567]86-*-netware*
4823 i[34567]86-*-sco3.2v5*
4824 i[34567]86-*-sco3.2v4*
4826 i[34567]86-*-sysv4.2*
4829 i[34567]86-*-unixware2*
4830 i[34567]86-*-unixware*
4839 * Other removed features
4846 Various m68k-only ROM monitors.
4853 Various Renesas ROM monitors and debugging interfaces for SH and
4858 Support for a Macraigor serial interface to on-chip debugging.
4859 GDB does not directly support the newer parallel or USB
4864 A debug information format. The predecessor to DWARF 2 and
4865 DWARF 3, which are still supported.
4867 Support for the HP aCC compiler on HP-UX/PA-RISC
4869 SOM-encapsulated symbolic debugging information, automatic
4870 invocation of pxdb, and the aCC custom C++ ABI. This does not
4871 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4872 with aCC can still be debugged on an assembly level.
4874 MIPS ".pdr" sections
4876 A MIPS-specific format used to describe stack frame layout
4877 in debugging information.
4881 GDB could work with an older version of Guile to debug
4882 the interpreter and Scheme programs running in it.
4884 set mips stack-arg-size
4885 set mips saved-gpreg-size
4887 Use "set mips abi" to control parameter passing for MIPS.
4889 *** Changes in GDB 6.6
4894 Cell Broadband Engine SPU spu-elf
4896 * GDB can now be configured as a cross-debugger targeting native Windows
4897 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4898 running on a Windows system over TCP/IP to debug Windows programs.
4900 * The GDB remote stub, gdbserver, has been updated to support Windows and
4901 Cygwin debugging. Both single-threaded and multi-threaded programs are
4904 * The "set trust-readonly-sections" command works again. This command was
4905 broken in GDB 6.3, 6.4, and 6.5.
4907 * The "load" command now supports writing to flash memory, if the remote
4908 stub provides the required support.
4910 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4911 longer requires symbolic debug information (e.g. DWARF-2).
4916 unset substitute-path
4917 show substitute-path
4918 Manage a list of substitution rules that GDB uses to rewrite the name
4919 of the directories where the sources are located. This can be useful
4920 for instance when the sources were moved to a different location
4921 between compilation and debugging.
4925 Print each CLI command as it is executed. Each command is prefixed with
4926 a number of `+' symbols representing the nesting depth.
4927 The source command now has a `-v' option to enable the same feature.
4931 The ARM Demon monitor support (RDP protocol, "target rdp").
4933 Kernel Object Display, an embedded debugging feature which only worked with
4934 an obsolete version of Cisco IOS.
4936 The 'set download-write-size' and 'show download-write-size' commands.
4938 * New remote packets
4941 Tell a stub about GDB client features, and request remote target features.
4942 The first feature implemented is PacketSize, which allows the target to
4943 specify the size of packets it can handle - to minimize the number of
4944 packets required and improve performance when connected to a remote
4948 Fetch an OS auxilliary vector from the remote stub. This packet is a
4949 more efficient replacement for qPart:auxv:read.
4951 qXfer:memory-map:read:
4952 Fetch a memory map from the remote stub, including information about
4953 RAM, ROM, and flash memory devices.
4958 Erase and program a flash memory device.
4960 * Removed remote packets
4963 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4964 used it, and only gdbserver implemented it.
4966 *** Changes in GDB 6.5
4970 Renesas M32C/M16C m32c-elf
4972 Morpho Technologies ms1 ms1-elf
4976 init-if-undefined Initialize a convenience variable, but
4977 only if it doesn't already have a value.
4979 The following commands are presently only implemented for native GNU/Linux:
4981 checkpoint Save a snapshot of the program state.
4983 restart <n> Return the program state to a
4984 previously saved state.
4986 info checkpoints List currently saved checkpoints.
4988 delete-checkpoint <n> Delete a previously saved checkpoint.
4990 set|show detach-on-fork Tell gdb whether to detach from a newly
4991 forked process, or to keep debugging it.
4993 info forks List forks of the user program that
4994 are available to be debugged.
4996 fork <n> Switch to debugging one of several
4997 forks of the user program that are
4998 available to be debugged.
5000 delete-fork <n> Delete a fork from the list of forks
5001 that are available to be debugged (and
5002 kill the forked process).
5004 detach-fork <n> Delete a fork from the list of forks
5005 that are available to be debugged (and
5006 allow the process to continue).
5010 Morpho Technologies ms2 ms1-elf
5012 * Improved Windows host support
5014 GDB now builds as a cross debugger hosted on i686-mingw32, including
5015 native console support, and remote communications using either
5016 network sockets or serial ports.
5018 * Improved Modula-2 language support
5020 GDB can now print most types in the Modula-2 syntax. This includes:
5021 basic types, set types, record types, enumerated types, range types,
5022 pointer types and ARRAY types. Procedure var parameters are correctly
5023 printed and hexadecimal addresses and character constants are also
5024 written in the Modula-2 syntax. Best results can be obtained by using
5025 GNU Modula-2 together with the -gdwarf-2 command line option.
5029 The ARM rdi-share module.
5031 The Netware NLM debug server.
5033 *** Changes in GDB 6.4
5035 * New native configurations
5037 OpenBSD/arm arm*-*-openbsd*
5038 OpenBSD/mips64 mips64-*-openbsd*
5042 Morpho Technologies ms1 ms1-elf
5044 * New command line options
5046 --batch-silent As for --batch, but totally silent.
5047 --return-child-result The debugger will exist with the same value
5048 the child (debugged) program exited with.
5049 --eval-command COMMAND, -ex COMMAND
5050 Execute a single GDB CLI command. This may be
5051 specified multiple times and in conjunction
5052 with the --command (-x) option.
5054 * Deprecated commands removed
5056 The following commands, that were deprecated in 2000, have been
5060 set|show arm disassembly-flavor set|show arm disassembler
5061 othernames set arm disassembler
5062 set|show remotedebug set|show debug remote
5063 set|show archdebug set|show debug arch
5064 set|show eventdebug set|show debug event
5067 * New BSD user-level threads support
5069 It is now possible to debug programs using the user-level threads
5070 library on OpenBSD and FreeBSD. Currently supported (target)
5073 FreeBSD/amd64 x86_64-*-freebsd*
5074 FreeBSD/i386 i386-*-freebsd*
5075 OpenBSD/i386 i386-*-openbsd*
5077 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5078 are not yet supported.
5080 * New support for Matsushita MN10300 w/sim added
5081 (Work in progress). mn10300-elf.
5083 * REMOVED configurations and files
5085 VxWorks and the XDR protocol *-*-vxworks
5086 Motorola MCORE mcore-*-*
5087 National Semiconductor NS32000 ns32k-*-*
5089 * New "set print array-indexes" command
5091 After turning this setting "on", GDB prints the index of each element
5092 when displaying arrays. The default is "off" to preserve the previous
5095 * VAX floating point support
5097 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5099 * User-defined command support
5101 In addition to using $arg0..$arg9 for argument passing, it is now possible
5102 to use $argc to determine now many arguments have been passed. See the
5103 section on user-defined commands in the user manual for more information.
5105 *** Changes in GDB 6.3:
5107 * New command line option
5109 GDB now accepts -l followed by a number to set the timeout for remote
5112 * GDB works with GCC -feliminate-dwarf2-dups
5114 GDB now supports a more compact representation of DWARF-2 debug
5115 information using DW_FORM_ref_addr references. These are produced
5116 by GCC with the option -feliminate-dwarf2-dups and also by some
5117 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5118 to use -feliminate-dwarf2-dups.
5120 * Internationalization
5122 When supported by the host system, GDB will be built with
5123 internationalization (libintl). The task of marking up the sources is
5124 continued, we're looking forward to our first translation.
5128 Initial support for debugging programs compiled with the GNAT
5129 implementation of the Ada programming language has been integrated
5130 into GDB. In this release, support is limited to expression evaluation.
5132 * New native configurations
5134 GNU/Linux/m32r m32r-*-linux-gnu
5138 GDB's remote protocol now includes support for the 'p' packet. This
5139 packet is used to fetch individual registers from a remote inferior.
5141 * END-OF-LIFE registers[] compatibility module
5143 GDB's internal register infrastructure has been completely rewritten.
5144 The new infrastructure making possible the implementation of key new
5145 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5148 GDB 6.3 will be the last release to include the the registers[]
5149 compatibility module that allowed out-of-date configurations to
5150 continue to work. This change directly impacts the following
5160 powerpc bdm protocol
5162 Unless there is activity to revive these configurations, they will be
5163 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5165 * OBSOLETE configurations and files
5167 Configurations that have been declared obsolete in this release have
5168 been commented out. Unless there is activity to revive these
5169 configurations, the next release of GDB will have their sources
5170 permanently REMOVED.
5179 *** Changes in GDB 6.2.1:
5181 * MIPS `break main; run' gave an heuristic-fence-post warning
5183 When attempting to run even a simple program, a warning about
5184 heuristic-fence-post being hit would be reported. This problem has
5187 * MIPS IRIX 'long double' crashed GDB
5189 When examining a long double variable, GDB would get a segmentation
5190 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5191 IRIX long double values).
5195 A bug in the VAX stack code was causing problems with the "next"
5196 command. This problem has been fixed.
5198 *** Changes in GDB 6.2:
5200 * Fix for ``many threads''
5202 On GNU/Linux systems that use the NPTL threads library, a program
5203 rapidly creating and deleting threads would confuse GDB leading to the
5206 ptrace: No such process.
5207 thread_db_get_info: cannot get thread info: generic error
5209 This problem has been fixed.
5211 * "-async" and "-noasync" options removed.
5213 Support for the broken "-noasync" option has been removed (it caused
5216 * New ``start'' command.
5218 This command runs the program until the begining of the main procedure.
5220 * New BSD Kernel Data Access Library (libkvm) interface
5222 Using ``target kvm'' it is now possible to debug kernel core dumps and
5223 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5224 platforms. Currently supported (native-only) configurations are:
5226 FreeBSD/amd64 x86_64-*-freebsd*
5227 FreeBSD/i386 i?86-*-freebsd*
5228 NetBSD/i386 i?86-*-netbsd*
5229 NetBSD/m68k m68*-*-netbsd*
5230 NetBSD/sparc sparc-*-netbsd*
5231 OpenBSD/amd64 x86_64-*-openbsd*
5232 OpenBSD/i386 i?86-*-openbsd*
5233 OpenBSD/m68k m68*-openbsd*
5234 OpenBSD/sparc sparc-*-openbsd*
5236 * Signal trampoline code overhauled
5238 Many generic problems with GDB's signal handling code have been fixed.
5239 These include: backtraces through non-contiguous stacks; recognition
5240 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5241 call; backtrace through a signal trampoline; step into and out of
5242 signal handlers; and single-stepping in the signal trampoline.
5244 Please note that kernel bugs are a limiting factor here. These
5245 features have been shown to work on an s390 GNU/Linux system that
5246 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5248 * Cygwin support for DWARF 2 added.
5250 * New native configurations
5252 GNU/Linux/hppa hppa*-*-linux*
5253 OpenBSD/hppa hppa*-*-openbsd*
5254 OpenBSD/m68k m68*-*-openbsd*
5255 OpenBSD/m88k m88*-*-openbsd*
5256 OpenBSD/powerpc powerpc-*-openbsd*
5257 NetBSD/vax vax-*-netbsd*
5258 OpenBSD/vax vax-*-openbsd*
5260 * END-OF-LIFE frame compatibility module
5262 GDB's internal frame infrastructure has been completely rewritten.
5263 The new infrastructure making it possible to support key new features
5264 including DWARF 2 Call Frame Information. To aid in the task of
5265 migrating old configurations to this new infrastructure, a
5266 compatibility module, that allowed old configurations to continue to
5267 work, was also included.
5269 GDB 6.2 will be the last release to include this frame compatibility
5270 module. This change directly impacts the following configurations:
5280 Unless there is activity to revive these configurations, they will be
5281 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5283 * REMOVED configurations and files
5285 Sun 3, running SunOS 3 m68*-*-sunos3*
5286 Sun 3, running SunOS 4 m68*-*-sunos4*
5287 Sun 2, running SunOS 3 m68000-*-sunos3*
5288 Sun 2, running SunOS 4 m68000-*-sunos4*
5289 Motorola 680x0 running LynxOS m68*-*-lynxos*
5290 AT&T 3b1/Unix pc m68*-att-*
5291 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5292 decstation mips-dec-* mips-little-*
5293 riscos mips-*-riscos* mips-*-sysv*
5294 sonymips mips-sony-*
5295 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5297 *** Changes in GDB 6.1.1:
5299 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5301 The TUI (Text-mode User Interface) is now built as part of a default
5302 GDB configuration. It is enabled by either selecting the TUI with the
5303 command line option "-i=tui" or by running the separate "gdbtui"
5304 program. For more information on the TUI, see the manual "Debugging
5307 * Pending breakpoint support (also included in GDB 6.1)
5309 Support has been added to allow you to specify breakpoints in shared
5310 libraries that have not yet been loaded. If a breakpoint location
5311 cannot be found, and the "breakpoint pending" option is set to auto,
5312 GDB queries you if you wish to make the breakpoint pending on a future
5313 shared-library load. If and when GDB resolves the breakpoint symbol,
5314 the pending breakpoint is removed as one or more regular breakpoints
5317 Pending breakpoints are very useful for GCJ Java debugging.
5319 * Fixed ISO-C build problems
5321 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5322 non ISO-C code that stopped them being built using a more strict ISO-C
5323 compiler (e.g., IBM's C compiler).
5325 * Fixed build problem on IRIX 5
5327 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5328 wasn't able to compile compile on an IRIX 5 system.
5330 * Added execute permission to gdb/gdbserver/configure
5332 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5333 permission. This bug would cause configure to fail on a number of
5334 systems (Solaris, IRIX). Ref: server/519.
5336 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5338 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5339 has been updated to use constant array sizes.
5341 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5343 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5344 its generated DWARF Call Frame Info. This encoding was causing GDB to
5345 panic, that panic has been fixed. Ref: gdb/1628.
5347 * Fixed a problem when examining parameters in shared library code.
5349 When examining parameters in optimized shared library code generated
5350 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5351 not available''. GDB now correctly displays the variable's value.
5353 *** Changes in GDB 6.1:
5355 * Removed --with-mmalloc
5357 Support for the mmalloc memory manager has been removed, as it
5358 conflicted with the internal gdb byte cache.
5360 * Changes in AMD64 configurations
5362 The AMD64 target now includes the %cs and %ss registers. As a result
5363 the AMD64 remote protocol has changed; this affects the floating-point
5364 and SSE registers. If you rely on those registers for your debugging,
5365 you should upgrade gdbserver on the remote side.
5367 * Revised SPARC target
5369 The SPARC target has been completely revised, incorporating the
5370 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5371 support for LynxOS and SunOS 4 has been dropped. Calling functions
5372 from within GDB on operating systems with a non-executable stack
5373 (Solaris, OpenBSD) now works.
5377 GDB has a new C++ demangler which does a better job on the mangled
5378 names generated by current versions of g++. It also runs faster, so
5379 with this and other changes gdb should now start faster on large C++
5382 * DWARF 2 Location Expressions
5384 GDB support for location expressions has been extended to support function
5385 arguments and frame bases. Older versions of GDB could crash when they
5388 * C++ nested types and namespaces
5390 GDB's support for nested types and namespaces in C++ has been
5391 improved, especially if you use the DWARF 2 debugging format. (This
5392 is the default for recent versions of GCC on most platforms.)
5393 Specifically, if you have a class "Inner" defined within a class or
5394 namespace "Outer", then GDB realizes that the class's name is
5395 "Outer::Inner", not simply "Inner". This should greatly reduce the
5396 frequency of complaints about not finding RTTI symbols. In addition,
5397 if you are stopped at inside of a function defined within a namespace,
5398 GDB modifies its name lookup accordingly.
5400 * New native configurations
5402 NetBSD/amd64 x86_64-*-netbsd*
5403 OpenBSD/amd64 x86_64-*-openbsd*
5404 OpenBSD/alpha alpha*-*-openbsd*
5405 OpenBSD/sparc sparc-*-openbsd*
5406 OpenBSD/sparc64 sparc64-*-openbsd*
5408 * New debugging protocols
5410 M32R with SDI protocol m32r-*-elf*
5412 * "set prompt-escape-char" command deleted.
5414 The command "set prompt-escape-char" has been deleted. This command,
5415 and its very obscure effet on GDB's prompt, was never documented,
5416 tested, nor mentioned in the NEWS file.
5418 * OBSOLETE configurations and files
5420 Configurations that have been declared obsolete in this release have
5421 been commented out. Unless there is activity to revive these
5422 configurations, the next release of GDB will have their sources
5423 permanently REMOVED.
5425 Sun 3, running SunOS 3 m68*-*-sunos3*
5426 Sun 3, running SunOS 4 m68*-*-sunos4*
5427 Sun 2, running SunOS 3 m68000-*-sunos3*
5428 Sun 2, running SunOS 4 m68000-*-sunos4*
5429 Motorola 680x0 running LynxOS m68*-*-lynxos*
5430 AT&T 3b1/Unix pc m68*-att-*
5431 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5432 decstation mips-dec-* mips-little-*
5433 riscos mips-*-riscos* mips-*-sysv*
5434 sonymips mips-sony-*
5435 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5437 * REMOVED configurations and files
5439 SGI Irix-4.x mips-sgi-irix4 or iris4
5440 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5441 Z8000 simulator z8k-zilog-none or z8ksim
5442 Matsushita MN10200 w/simulator mn10200-*-*
5443 H8/500 simulator h8500-hitachi-hms or h8500hms
5444 HP/PA running BSD hppa*-*-bsd*
5445 HP/PA running OSF/1 hppa*-*-osf*
5446 HP/PA Pro target hppa*-*-pro*
5447 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5448 386BSD i[3456]86-*-bsd*
5449 Sequent family i[3456]86-sequent-sysv4*
5450 i[3456]86-sequent-sysv*
5451 i[3456]86-sequent-bsd*
5452 SPARC running LynxOS sparc-*-lynxos*
5453 SPARC running SunOS 4 sparc-*-sunos4*
5454 Tsqware Sparclet sparclet-*-*
5455 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5457 *** Changes in GDB 6.0:
5461 Support for debugging the Objective-C programming language has been
5462 integrated into GDB.
5464 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5466 DWARF 2's Call Frame Information makes available compiler generated
5467 information that more exactly describes the program's run-time stack.
5468 By using this information, GDB is able to provide more robust stack
5471 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5472 have been updated to use a new backtrace mechanism which includes
5473 DWARF 2 CFI support.
5477 GDB's remote protocol has been extended to include support for hosted
5478 file I/O (where the remote target uses GDB's file system). See GDB's
5479 remote protocol documentation for details.
5481 * All targets using the new architecture framework.
5483 All of GDB's targets have been updated to use the new internal
5484 architecture framework. The way is now open for future GDB releases
5485 to include cross-architecture native debugging support (i386 on amd64,
5488 * GNU/Linux's Thread Local Storage (TLS)
5490 GDB now includes support for for the GNU/Linux implementation of
5491 per-thread variables.
5493 * GNU/Linux's Native POSIX Thread Library (NPTL)
5495 GDB's thread code has been updated to work with either the new
5496 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5498 * Separate debug info.
5500 GDB, in conjunction with BINUTILS, now supports a mechanism for
5501 automatically loading debug information from a separate file. Instead
5502 of shipping full debug and non-debug versions of system libraries,
5503 system integrators can now instead ship just the stripped libraries
5504 and optional debug files.
5506 * DWARF 2 Location Expressions
5508 DWARF 2 Location Expressions allow the compiler to more completely
5509 describe the location of variables (even in optimized code) to the
5512 GDB now includes preliminary support for location expressions (support
5513 for DW_OP_piece is still missing).
5517 A number of long standing bugs that caused GDB to die while starting a
5518 Java application have been fixed. GDB's Java support is now
5519 considered "useable".
5521 * GNU/Linux support for fork, vfork, and exec.
5523 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5524 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5527 * GDB supports logging output to a file
5529 There are two new commands, "set logging" and "show logging", which can be
5530 used to capture GDB's output to a file.
5532 * The meaning of "detach" has changed for gdbserver
5534 The "detach" command will now resume the application, as documented. To
5535 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5538 * d10v, m68hc11 `regs' command deprecated
5540 The `info registers' command has been updated so that it displays the
5541 registers using a format identical to the old `regs' command.
5545 A new command, "maint set profile on/off", has been added. This command can
5546 be used to enable or disable profiling while running GDB, to profile a
5547 session or a set of commands. In addition there is a new configure switch,
5548 "--enable-profiling", which will cause GDB to be compiled with profiling
5549 data, for more informative profiling results.
5551 * Default MI syntax changed to "mi2".
5553 The default MI (machine interface) syntax, enabled by the command line
5554 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5555 "mi1", can be enabled by specifying the option "-i=mi1".
5557 Support for the original "mi0" syntax (included in GDB 5.0) has been
5560 Fix for gdb/192: removed extraneous space when displaying frame level.
5561 Fix for gdb/672: update changelist is now output in mi list format.
5562 Fix for gdb/702: a -var-assign that updates the value now shows up
5563 in a subsequent -var-update.
5565 * New native configurations.
5567 FreeBSD/amd64 x86_64-*-freebsd*
5569 * Multi-arched targets.
5571 HP/PA HPUX11 hppa*-*-hpux*
5572 Renesas M32R/D w/simulator m32r-*-elf*
5574 * OBSOLETE configurations and files
5576 Configurations that have been declared obsolete in this release have
5577 been commented out. Unless there is activity to revive these
5578 configurations, the next release of GDB will have their sources
5579 permanently REMOVED.
5581 Z8000 simulator z8k-zilog-none or z8ksim
5582 Matsushita MN10200 w/simulator mn10200-*-*
5583 H8/500 simulator h8500-hitachi-hms or h8500hms
5584 HP/PA running BSD hppa*-*-bsd*
5585 HP/PA running OSF/1 hppa*-*-osf*
5586 HP/PA Pro target hppa*-*-pro*
5587 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5588 Sequent family i[3456]86-sequent-sysv4*
5589 i[3456]86-sequent-sysv*
5590 i[3456]86-sequent-bsd*
5591 Tsqware Sparclet sparclet-*-*
5592 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5594 * REMOVED configurations and files
5597 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5598 IBM AIX PS/2 i[3456]86-*-aix
5599 i386 running Mach 3.0 i[3456]86-*-mach3*
5600 i386 running Mach i[3456]86-*-mach*
5601 i386 running OSF/1 i[3456]86-*osf1mk*
5602 HP/Apollo 68k Family m68*-apollo*-sysv*,
5604 m68*-hp-bsd*, m68*-hp-hpux*
5605 Argonaut Risc Chip (ARC) arc-*-*
5606 Mitsubishi D30V d30v-*-*
5607 Fujitsu FR30 fr30-*-elf*
5608 OS/9000 i[34]86-*-os9k
5609 I960 with MON960 i960-*-coff
5611 * MIPS $fp behavior changed
5613 The convenience variable $fp, for the MIPS, now consistently returns
5614 the address of the current frame's base. Previously, depending on the
5615 context, $fp could refer to either $sp or the current frame's base
5616 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5617 The GNU Source-Level Debugger''.
5619 *** Changes in GDB 5.3:
5621 * GNU/Linux shared library multi-threaded performance improved.
5623 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5624 `/proc', in preference to `ptrace' for memory reads. This may result
5625 in an improvement in the start-up time of multi-threaded, shared
5626 library applications when run under GDB. One GDB user writes: ``loads
5627 shared libs like mad''.
5629 * ``gdbserver'' now supports multi-threaded applications on some targets
5631 Support for debugging multi-threaded applications which use
5632 the GNU/Linux LinuxThreads package has been added for
5633 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5634 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5636 * GDB now supports C/C++ preprocessor macros.
5638 GDB now expands preprocessor macro invocations in C/C++ expressions,
5639 and provides various commands for showing macro definitions and how
5642 The new command `macro expand EXPRESSION' expands any macro
5643 invocations in expression, and shows the result.
5645 The new command `show macro MACRO-NAME' shows the definition of the
5646 macro named MACRO-NAME, and where it was defined.
5648 Most compilers don't include information about macros in the debugging
5649 information by default. In GCC 3.1, for example, you need to compile
5650 your program with the options `-gdwarf-2 -g3'. If the macro
5651 information is present in the executable, GDB will read it.
5653 * Multi-arched targets.
5655 DEC Alpha (partial) alpha*-*-*
5656 DEC VAX (partial) vax-*-*
5658 National Semiconductor NS32000 (partial) ns32k-*-*
5659 Motorola 68000 (partial) m68k-*-*
5660 Motorola MCORE mcore-*-*
5664 Fujitsu FRV architecture added by Red Hat frv*-*-*
5667 * New native configurations
5669 Alpha NetBSD alpha*-*-netbsd*
5670 SH NetBSD sh*-*-netbsdelf*
5671 MIPS NetBSD mips*-*-netbsd*
5672 UltraSPARC NetBSD sparc64-*-netbsd*
5674 * OBSOLETE configurations and files
5676 Configurations that have been declared obsolete in this release have
5677 been commented out. Unless there is activity to revive these
5678 configurations, the next release of GDB will have their sources
5679 permanently REMOVED.
5681 Mitsubishi D30V d30v-*-*
5682 OS/9000 i[34]86-*-os9k
5683 IBM AIX PS/2 i[3456]86-*-aix
5684 Fujitsu FR30 fr30-*-elf*
5685 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5686 Argonaut Risc Chip (ARC) arc-*-*
5687 i386 running Mach 3.0 i[3456]86-*-mach3*
5688 i386 running Mach i[3456]86-*-mach*
5689 i386 running OSF/1 i[3456]86-*osf1mk*
5690 HP/Apollo 68k Family m68*-apollo*-sysv*,
5692 m68*-hp-bsd*, m68*-hp-hpux*
5693 I960 with MON960 i960-*-coff
5695 * OBSOLETE languages
5697 CHILL, a Pascal like language used by telecommunications companies.
5699 * REMOVED configurations and files
5701 AMD 29k family via UDI a29k-amd-udi, udi29k
5702 A29K VxWorks a29k-*-vxworks
5703 AMD 29000 embedded, using EBMON a29k-none-none
5704 AMD 29000 embedded with COFF a29k-none-coff
5705 AMD 29000 embedded with a.out a29k-none-aout
5707 testsuite/gdb.hp/gdb.threads-hp/ directory
5709 * New command "set max-user-call-depth <nnn>"
5711 This command allows the user to limit the call depth of user-defined
5712 commands. The default is 1024.
5714 * Changes in FreeBSD/i386 native debugging.
5716 Support for the "generate-core-file" has been added.
5718 * New commands "dump", "append", and "restore".
5720 These commands allow data to be copied from target memory
5721 to a bfd-format or binary file (dump and append), and back
5722 from a file into memory (restore).
5724 * Improved "next/step" support on multi-processor Alpha Tru64.
5726 The previous single-step mechanism could cause unpredictable problems,
5727 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5728 of a software single-step mechanism prevents this.
5730 *** Changes in GDB 5.2.1:
5738 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5739 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5740 Fix, by Joel Brobecker imported from mainline.
5742 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5743 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5744 Fix, by Fred Fish, imported from mainline.
5746 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5747 Surprisingly enough, it works now.
5748 By Michal Ludvig, imported from mainline.
5750 i386 hardware watchpoint support:
5751 avoid misses on second run for some targets.
5752 By Pierre Muller, imported from mainline.
5754 *** Changes in GDB 5.2:
5756 * New command "set trust-readonly-sections on[off]".
5758 This command is a hint that tells gdb that read-only sections
5759 really are read-only (ie. that their contents will not change).
5760 In this mode, gdb will go to the object file rather than the
5761 target to read memory from read-only sections (such as ".text").
5762 This can be a significant performance improvement on some
5763 (notably embedded) targets.
5765 * New command "generate-core-file" (or "gcore").
5767 This new gdb command allows the user to drop a core file of the child
5768 process state at any time. So far it's been implemented only for
5769 GNU/Linux and Solaris, but should be relatively easily ported to other
5770 hosts. Argument is core file name (defaults to core.<pid>).
5772 * New command line option
5774 GDB now accepts --pid or -p followed by a process id.
5776 * Change in command line behavior -- corefiles vs. process ids.
5778 There is a subtle behavior in the way in which GDB handles
5779 command line arguments. The first non-flag argument is always
5780 a program to debug, but the second non-flag argument may either
5781 be a corefile or a process id. Previously, GDB would attempt to
5782 open the second argument as a corefile, and if that failed, would
5783 issue a superfluous error message and then attempt to attach it as
5784 a process. Now, if the second argument begins with a non-digit,
5785 it will be treated as a corefile. If it begins with a digit,
5786 GDB will attempt to attach it as a process, and if no such process
5787 is found, will then attempt to open it as a corefile.
5789 * Changes in ARM configurations.
5791 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5792 configuration is fully multi-arch.
5794 * New native configurations
5796 ARM NetBSD arm*-*-netbsd*
5797 x86 OpenBSD i[3456]86-*-openbsd*
5798 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5799 Sparc64 running FreeBSD sparc64-*-freebsd*
5803 Sanyo XStormy16 xstormy16-elf
5805 * OBSOLETE configurations and files
5807 Configurations that have been declared obsolete in this release have
5808 been commented out. Unless there is activity to revive these
5809 configurations, the next release of GDB will have their sources
5810 permanently REMOVED.
5812 AMD 29k family via UDI a29k-amd-udi, udi29k
5813 A29K VxWorks a29k-*-vxworks
5814 AMD 29000 embedded, using EBMON a29k-none-none
5815 AMD 29000 embedded with COFF a29k-none-coff
5816 AMD 29000 embedded with a.out a29k-none-aout
5818 testsuite/gdb.hp/gdb.threads-hp/ directory
5820 * REMOVED configurations and files
5822 TI TMS320C80 tic80-*-*
5824 PowerPC Solaris powerpcle-*-solaris*
5825 PowerPC Windows NT powerpcle-*-cygwin32
5826 PowerPC Netware powerpc-*-netware*
5827 Harris/CXUX m88k m88*-harris-cxux*
5828 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5829 ns32k-utek-sysv* ns32k-utek-*
5830 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5831 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5832 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5833 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5834 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5836 * Changes to command line processing
5838 The new `--args' feature can be used to specify command-line arguments
5839 for the inferior from gdb's command line.
5841 * Changes to key bindings
5843 There is a new `operate-and-get-next' function bound to `C-o'.
5845 *** Changes in GDB 5.1.1
5847 Fix compile problem on DJGPP.
5849 Fix a problem with floating-point registers on the i386 being
5852 Fix to stop GDB crashing on .debug_str debug info.
5854 Numerous documentation fixes.
5856 Numerous testsuite fixes.
5858 *** Changes in GDB 5.1:
5860 * New native configurations
5862 Alpha FreeBSD alpha*-*-freebsd*
5863 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5864 MIPS GNU/Linux mips*-*-linux*
5865 MIPS SGI Irix 6.x mips*-sgi-irix6*
5866 ia64 AIX ia64-*-aix*
5867 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5871 Motorola 68HC11 and 68HC12 m68hc11-elf
5873 UltraSparc running GNU/Linux sparc64-*-linux*
5875 * OBSOLETE configurations and files
5877 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5878 Harris/CXUX m88k m88*-harris-cxux*
5879 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5880 ns32k-utek-sysv* ns32k-utek-*
5881 TI TMS320C80 tic80-*-*
5883 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5884 PowerPC Solaris powerpcle-*-solaris*
5885 PowerPC Windows NT powerpcle-*-cygwin32
5886 PowerPC Netware powerpc-*-netware*
5887 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5888 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5889 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5890 Apple Macintosh (MPW) host N/A
5892 stuff.c (Program to stuff files into a specially prepared space in kdb)
5893 kdb-start.c (Main loop for the standalone kernel debugger)
5895 Configurations that have been declared obsolete in this release have
5896 been commented out. Unless there is activity to revive these
5897 configurations, the next release of GDB will have their sources
5898 permanently REMOVED.
5900 * REMOVED configurations and files
5902 Altos 3068 m68*-altos-*
5903 Convex c1-*-*, c2-*-*
5905 ARM RISCix arm-*-* (as host)
5909 * GDB has been converted to ISO C.
5911 GDB's source code has been converted to ISO C. In particular, the
5912 sources are fully protoized, and rely on standard headers being
5917 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5919 * The MI enabled by default.
5921 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5922 revised and enabled by default. Packages which use GDB as a debugging
5923 engine behind a UI or another front end are encouraged to switch to
5924 using the GDB/MI interface, instead of the old annotations interface
5925 which is now deprecated.
5927 * Support for debugging Pascal programs.
5929 GDB now includes support for debugging Pascal programs. The following
5930 main features are supported:
5932 - Pascal-specific data types such as sets;
5934 - automatic recognition of Pascal sources based on file-name
5937 - Pascal-style display of data types, variables, and functions;
5939 - a Pascal expression parser.
5941 However, some important features are not yet supported.
5943 - Pascal string operations are not supported at all;
5945 - there are some problems with boolean types;
5947 - Pascal type hexadecimal constants are not supported
5948 because they conflict with the internal variables format;
5950 - support for Pascal objects and classes is not full yet;
5952 - unlike Pascal, GDB is case-sensitive for symbol names.
5954 * Changes in completion.
5956 Commands such as `shell', `run' and `set args', which pass arguments
5957 to inferior programs, now complete on file names, similar to what
5958 users expect at the shell prompt.
5960 Commands which accept locations, such as `disassemble', `print',
5961 `breakpoint', `until', etc. now complete on filenames as well as
5962 program symbols. Thus, if you type "break foob TAB", and the source
5963 files linked into the programs include `foobar.c', that file name will
5964 be one of the candidates for completion. However, file names are not
5965 considered for completion after you typed a colon that delimits a file
5966 name from a name of a function in that file, as in "break foo.c:bar".
5968 `set demangle-style' completes on available demangling styles.
5970 * New platform-independent commands:
5972 It is now possible to define a post-hook for a command as well as a
5973 hook that runs before the command. For more details, see the
5974 documentation of `hookpost' in the GDB manual.
5976 * Changes in GNU/Linux native debugging.
5978 Support for debugging multi-threaded programs has been completely
5979 revised for all platforms except m68k and sparc. You can now debug as
5980 many threads as your system allows you to have.
5982 Attach/detach is supported for multi-threaded programs.
5984 Support for SSE registers was added for x86. This doesn't work for
5985 multi-threaded programs though.
5987 * Changes in MIPS configurations.
5989 Multi-arch support is enabled for all MIPS configurations.
5991 GDB can now be built as native debugger on SGI Irix 6.x systems for
5992 debugging n32 executables. (Debugging 64-bit executables is not yet
5995 * Unified support for hardware watchpoints in all x86 configurations.
5997 Most (if not all) native x86 configurations support hardware-assisted
5998 breakpoints and watchpoints in a unified manner. This support
5999 implements debug register sharing between watchpoints, which allows to
6000 put a virtually infinite number of watchpoints on the same address,
6001 and also supports watching regions up to 16 bytes with several debug
6004 The new maintenance command `maintenance show-debug-regs' toggles
6005 debugging print-outs in functions that insert, remove, and test
6006 watchpoints and hardware breakpoints.
6008 * Changes in the DJGPP native configuration.
6010 New command ``info dos sysinfo'' displays assorted information about
6011 the CPU, OS, memory, and DPMI server.
6013 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6014 display information about segment descriptors stored in GDT, LDT, and
6017 New commands ``info dos pde'' and ``info dos pte'' display entries
6018 from Page Directory and Page Tables (for now works with CWSDPMI only).
6019 New command ``info dos address-pte'' displays the Page Table entry for
6020 a given linear address.
6022 GDB can now pass command lines longer than 126 characters to the
6023 program being debugged (requires an update to the libdbg.a library
6024 which is part of the DJGPP development kit).
6026 DWARF2 debug info is now supported.
6028 It is now possible to `step' and `next' through calls to `longjmp'.
6030 * Changes in documentation.
6032 All GDB documentation was converted to GFDL, the GNU Free
6033 Documentation License.
6035 Tracepoints-related commands are now fully documented in the GDB
6038 TUI, the Text-mode User Interface, is now documented in the manual.
6040 Tracepoints-related commands are now fully documented in the GDB
6043 The "GDB Internals" manual now has an index. It also includes
6044 documentation of `ui_out' functions, GDB coding standards, x86
6045 hardware watchpoints, and memory region attributes.
6047 * GDB's version number moved to ``version.in''
6049 The Makefile variable VERSION has been replaced by the file
6050 ``version.in''. People creating GDB distributions should update the
6051 contents of this file.
6055 GUD support is now a standard part of the EMACS distribution.
6057 *** Changes in GDB 5.0:
6059 * Improved support for debugging FP programs on x86 targets
6061 Unified and much-improved support for debugging floating-point
6062 programs on all x86 targets. In particular, ``info float'' now
6063 displays the FP registers in the same format on all x86 targets, with
6064 greater level of detail.
6066 * Improvements and bugfixes in hardware-assisted watchpoints
6068 It is now possible to watch array elements, struct members, and
6069 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6070 on x86 targets no longer erroneously trigger when the address is
6073 * Improvements in the native DJGPP version of GDB
6075 The distribution now includes all the scripts and auxiliary files
6076 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6077 machines ``out of the box''.
6079 The DJGPP version can now debug programs that use signals. It is
6080 possible to catch signals that happened in the debuggee, deliver
6081 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6082 would kill the program being debugged.) Programs that hook hardware
6083 interrupts (keyboard, timer, etc.) can also be debugged.
6085 It is now possible to debug DJGPP programs that redirect their
6086 standard handles or switch them to raw (as opposed to cooked) mode, or
6087 even close them. The command ``run < foo > bar'' works as expected,
6088 and ``info terminal'' reports useful information about the debuggee's
6089 terminal, including raw/cooked mode, redirection, etc.
6091 The DJGPP version now uses termios functions for console I/O, which
6092 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6095 DOS-style file names with drive letters are now fully supported by
6098 It is now possible to debug DJGPP programs that switch their working
6099 directory. It is also possible to rerun the debuggee any number of
6100 times without restarting GDB; thus, you can use the same setup,
6101 breakpoints, etc. for many debugging sessions.
6103 * New native configurations
6105 ARM GNU/Linux arm*-*-linux*
6106 PowerPC GNU/Linux powerpc-*-linux*
6110 Motorola MCore mcore-*-*
6111 x86 VxWorks i[3456]86-*-vxworks*
6112 PowerPC VxWorks powerpc-*-vxworks*
6113 TI TMS320C80 tic80-*-*
6115 * OBSOLETE configurations
6117 Altos 3068 m68*-altos-*
6118 Convex c1-*-*, c2-*-*
6120 ARM RISCix arm-*-* (as host)
6123 Configurations that have been declared obsolete will be commented out,
6124 but the code will be left in place. If there is no activity to revive
6125 these configurations before the next release of GDB, the sources will
6126 be permanently REMOVED.
6128 * Gould support removed
6130 Support for the Gould PowerNode and NP1 has been removed.
6132 * New features for SVR4
6134 On SVR4 native platforms (such as Solaris), if you attach to a process
6135 without first loading a symbol file, GDB will now attempt to locate and
6136 load symbols from the running process's executable file.
6138 * Many C++ enhancements
6140 C++ support has been greatly improved. Overload resolution now works properly
6141 in almost all cases. RTTI support is on the way.
6143 * Remote targets can connect to a sub-program
6145 A popen(3) style serial-device has been added. This device starts a
6146 sub-process (such as a stand-alone simulator) and then communicates
6147 with that. The sub-program to run is specified using the syntax
6148 ``|<program> <args>'' vis:
6150 (gdb) set remotedebug 1
6151 (gdb) target extended-remote |mn10300-elf-sim program-args
6153 * MIPS 64 remote protocol
6155 A long standing bug in the mips64 remote protocol where by GDB
6156 expected certain 32 bit registers (ex SR) to be transfered as 32
6157 instead of 64 bits has been fixed.
6159 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6160 added to provide backward compatibility with older versions of GDB.
6162 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6164 The command ``set remotebinarydownload'' command has been replaced by
6165 ``set remote X-packet''. Other commands in ``set remote'' family
6166 include ``set remote P-packet''.
6168 * Breakpoint commands accept ranges.
6170 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6171 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6172 ``tracepoint passcount'' also accepts a range of tracepoints.
6174 * ``apropos'' command added.
6176 The ``apropos'' command searches through command names and
6177 documentation strings, printing out matches, making it much easier to
6178 try to find a command that does what you are looking for.
6182 A new machine oriented interface (MI) has been added to GDB. This
6183 interface is designed for debug environments running GDB as a separate
6184 process. This is part of the long term libGDB project. See the
6185 "GDB/MI" chapter of the GDB manual for further information. It can be
6186 enabled by configuring with:
6188 .../configure --enable-gdbmi
6190 *** Changes in GDB-4.18:
6192 * New native configurations
6194 HP-UX 10.20 hppa*-*-hpux10.20
6195 HP-UX 11.x hppa*-*-hpux11.0*
6196 M68K GNU/Linux m68*-*-linux*
6200 Fujitsu FR30 fr30-*-elf*
6201 Intel StrongARM strongarm-*-*
6202 Mitsubishi D30V d30v-*-*
6204 * OBSOLETE configurations
6206 Gould PowerNode, NP1 np1-*-*, pn-*-*
6208 Configurations that have been declared obsolete will be commented out,
6209 but the code will be left in place. If there is no activity to revive
6210 these configurations before the next release of GDB, the sources will
6211 be permanently REMOVED.
6215 As a compatibility experiment, GDB's source files buildsym.h and
6216 buildsym.c have been converted to pure standard C, no longer
6217 containing any K&R compatibility code. We believe that all systems in
6218 use today either come with a standard C compiler, or have a GCC port
6219 available. If this is not true, please report the affected
6220 configuration to bug-gdb@gnu.org immediately. See the README file for
6221 information about getting a standard C compiler if you don't have one
6226 GDB now uses readline 2.2.
6228 * set extension-language
6230 You can now control the mapping between filename extensions and source
6231 languages by using the `set extension-language' command. For instance,
6232 you can ask GDB to treat .c files as C++ by saying
6233 set extension-language .c c++
6234 The command `info extensions' lists all of the recognized extensions
6235 and their associated languages.
6237 * Setting processor type for PowerPC and RS/6000
6239 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6240 you can use the `set processor' command to specify what variant of the
6241 PowerPC family you are debugging. The command
6245 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6246 following PowerPC and RS6000 variants:
6248 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6249 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6251 403GC IBM PowerPC 403GC
6252 505 Motorola PowerPC 505
6253 860 Motorola PowerPC 860 or 850
6254 601 Motorola PowerPC 601
6255 602 Motorola PowerPC 602
6256 603 Motorola/IBM PowerPC 603 or 603e
6257 604 Motorola PowerPC 604 or 604e
6258 750 Motorola/IBM PowerPC 750 or 750
6260 At the moment, this command just tells GDB what to name the
6261 special-purpose processor registers. Since almost all the affected
6262 registers are inaccessible to user-level programs, this command is
6263 only useful for remote debugging in its present form.
6267 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6268 more extensive support for HP-UX. Added features include shared
6269 library support, kernel threads and hardware watchpoints for 11.00,
6270 support for HP's ANSI C and C++ compilers, and a compatibility mode
6271 for xdb and dbx commands.
6275 HP's donation includes the new concept of catchpoints, which is a
6276 generalization of the old catch command. On HP-UX, it is now possible
6277 to catch exec, fork, and vfork, as well as library loading.
6279 This means that the existing catch command has changed; its first
6280 argument now specifies the type of catch to be set up. See the
6281 output of "help catch" for a list of catchpoint types.
6283 * Debugging across forks
6285 On HP-UX, you can choose which process to debug when a fork() happens
6290 HP has donated a curses-based terminal user interface (TUI). To get
6291 it, build with --enable-tui. Although this can be enabled for any
6292 configuration, at present it only works for native HP debugging.
6294 * GDB remote protocol additions
6296 A new protocol packet 'X' that writes binary data is now available.
6297 Default behavior is to try 'X', then drop back to 'M' if the stub
6298 fails to respond. The settable variable `remotebinarydownload'
6299 allows explicit control over the use of 'X'.
6301 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6302 full 64-bit address. The command
6304 set remoteaddresssize 32
6306 can be used to revert to the old behaviour. For existing remote stubs
6307 the change should not be noticed, as the additional address information
6310 In order to assist in debugging stubs, you may use the maintenance
6311 command `packet' to send any text string to the stub. For instance,
6313 maint packet heythere
6315 sends the packet "$heythere#<checksum>". Note that it is very easy to
6316 disrupt a debugging session by sending the wrong packet at the wrong
6319 The compare-sections command allows you to compare section data on the
6320 target to what is in the executable file without uploading or
6321 downloading, by comparing CRC checksums.
6323 * Tracing can collect general expressions
6325 You may now collect general expressions at tracepoints. This requires
6326 further additions to the target-side stub; see tracepoint.c and
6327 doc/agentexpr.texi for further details.
6329 * mask-address variable for Mips
6331 For Mips targets, you may control the zeroing of the upper 32 bits of
6332 a 64-bit address by entering `set mask-address on'. This is mainly
6333 of interest to users of embedded R4xxx and R5xxx processors.
6335 * Higher serial baud rates
6337 GDB's serial code now allows you to specify baud rates 57600, 115200,
6338 230400, and 460800 baud. (Note that your host system may not be able
6339 to achieve all of these rates.)
6343 The i960 configuration now includes an initial implementation of a
6344 builtin simulator, contributed by Jim Wilson.
6347 *** Changes in GDB-4.17:
6349 * New native configurations
6351 Alpha GNU/Linux alpha*-*-linux*
6352 Unixware 2.x i[3456]86-unixware2*
6353 Irix 6.x mips*-sgi-irix6*
6354 PowerPC GNU/Linux powerpc-*-linux*
6355 PowerPC Solaris powerpcle-*-solaris*
6356 Sparc GNU/Linux sparc-*-linux*
6357 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6361 Argonaut Risc Chip (ARC) arc-*-*
6362 Hitachi H8/300S h8300*-*-*
6363 Matsushita MN10200 w/simulator mn10200-*-*
6364 Matsushita MN10300 w/simulator mn10300-*-*
6365 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6366 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6367 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6368 Mitsubishi D10V w/simulator d10v-*-*
6369 Mitsubishi M32R/D w/simulator m32r-*-elf*
6370 Tsqware Sparclet sparclet-*-*
6371 NEC V850 w/simulator v850-*-*
6373 * New debugging protocols
6375 ARM with RDI protocol arm*-*-*
6376 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6377 DDB and LSI variants of PMON protocol mips*-*-*
6378 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6379 PowerPC with SDS protocol powerpc{,le}-*-eabi
6380 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6384 All configurations can now understand and use the DWARF 2 debugging
6385 format. The choice is automatic, if the symbol file contains DWARF 2
6390 GDB now includes basic Java language support. This support is
6391 only useful with Java compilers that produce native machine code.
6393 * solib-absolute-prefix and solib-search-path
6395 For SunOS and SVR4 shared libraries, you may now set the prefix for
6396 loading absolute shared library symbol files, and the search path for
6397 locating non-absolute shared library symbol files.
6399 * Live range splitting
6401 GDB can now effectively debug code for which GCC has performed live
6402 range splitting as part of its optimization. See gdb/doc/LRS for
6403 more details on the expected format of the stabs information.
6407 GDB's support for the GNU Hurd, including thread debugging, has been
6408 updated to work with current versions of the Hurd.
6412 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6413 instruction set. ARM GDB automatically detects when Thumb
6414 instructions are in use, and adjusts disassembly and backtracing
6419 GDB's MIPS target configurations now handle the MIP16 16-bit
6424 GDB now includes support for overlays; if an executable has been
6425 linked such that multiple sections are based at the same address, GDB
6426 will decide which section to use for symbolic info. You can choose to
6427 control the decision manually, using overlay commands, or implement
6428 additional target-side support and use "overlay load-target" to bring
6429 in the overlay mapping. Do "help overlay" for more detail.
6433 The command "info symbol <address>" displays information about
6434 the symbol at the specified address.
6438 The standard remote protocol now includes an extension that allows
6439 asynchronous collection and display of trace data. This requires
6440 extensive support in the target-side debugging stub. Tracing mode
6441 includes a new interaction mode in GDB and new commands: see the
6442 file tracepoint.c for more details.
6446 Configurations for embedded MIPS now include a simulator contributed
6447 by Cygnus Solutions. The simulator supports the instruction sets
6448 of most MIPS variants.
6452 Sparc configurations may now include the ERC32 simulator contributed
6453 by the European Space Agency. The simulator is not built into
6454 Sparc targets by default; configure with --enable-sim to include it.
6458 For target configurations that may include multiple variants of a
6459 basic architecture (such as MIPS and SH), you may now set the
6460 architecture explicitly. "set arch" sets, "info arch" lists
6461 the possible architectures.
6463 *** Changes in GDB-4.16:
6465 * New native configurations
6467 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6468 M68K NetBSD m68k-*-netbsd*
6469 PowerPC AIX 4.x powerpc-*-aix*
6470 PowerPC MacOS powerpc-*-macos*
6471 PowerPC Windows NT powerpcle-*-cygwin32
6472 RS/6000 AIX 4.x rs6000-*-aix4*
6476 ARM with RDP protocol arm-*-*
6477 I960 with MON960 i960-*-coff
6478 MIPS VxWorks mips*-*-vxworks*
6479 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6480 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6482 Matra Sparclet sparclet-*-*
6486 The powerpc-eabi configuration now includes the PSIM simulator,
6487 contributed by Andrew Cagney, with assistance from Mike Meissner.
6488 PSIM is a very elaborate model of the PowerPC, including not only
6489 basic instruction set execution, but also details of execution unit
6490 performance and I/O hardware. See sim/ppc/README for more details.
6494 GDB now works with Solaris 2.5.
6496 * Windows 95/NT native
6498 GDB will now work as a native debugger on Windows 95 and Windows NT.
6499 To build it from source, you must use the "gnu-win32" environment,
6500 which uses a DLL to emulate enough of Unix to run the GNU tools.
6501 Further information, binaries, and sources are available at
6502 ftp.cygnus.com, under pub/gnu-win32.
6504 * dont-repeat command
6506 If a user-defined command includes the command `dont-repeat', then the
6507 command will not be repeated if the user just types return. This is
6508 useful if the command is time-consuming to run, so that accidental
6509 extra keystrokes don't run the same command many times.
6511 * Send break instead of ^C
6513 The standard remote protocol now includes an option to send a break
6514 rather than a ^C to the target in order to interrupt it. By default,
6515 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6517 * Remote protocol timeout
6519 The standard remote protocol includes a new variable `remotetimeout'
6520 that allows you to set the number of seconds before GDB gives up trying
6521 to read from the target. The default value is 2.
6523 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6525 By default GDB will automatically keep track of objects as they are
6526 loaded and unloaded by the dynamic linker. By using the command `set
6527 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6528 when shared library events occur, thus allowing you to set breakpoints
6529 in shared libraries which are explicitly loaded by the inferior.
6531 Note this feature does not work on hpux8. On hpux9 you must link
6532 /usr/lib/end.o into your program. This feature should work
6533 automatically on hpux10.
6535 * Irix 5.x hardware watchpoint support
6537 Irix 5 configurations now support the use of hardware watchpoints.
6539 * Mips protocol "SYN garbage limit"
6541 When debugging a Mips target using the `target mips' protocol, you
6542 may set the number of characters that GDB will ignore by setting
6543 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6544 every character. The default value is 1050.
6546 * Recording and replaying remote debug sessions
6548 If you set `remotelogfile' to the name of a file, gdb will write to it
6549 a recording of a remote debug session. This recording may then be
6550 replayed back to gdb using "gdbreplay". See gdbserver/README for
6551 details. This is useful when you have a problem with GDB while doing
6552 remote debugging; you can make a recording of the session and send it
6553 to someone else, who can then recreate the problem.
6555 * Speedups for remote debugging
6557 GDB includes speedups for downloading and stepping MIPS systems using
6558 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6559 and more efficient S-record downloading.
6561 * Memory use reductions and statistics collection
6563 GDB now uses less memory and reports statistics about memory usage.
6564 Try the `maint print statistics' command, for example.
6566 *** Changes in GDB-4.15:
6568 * Psymtabs for XCOFF
6570 The symbol reader for AIX GDB now uses partial symbol tables. This
6571 can greatly improve startup time, especially for large executables.
6573 * Remote targets use caching
6575 Remote targets now use a data cache to speed up communication with the
6576 remote side. The data cache could lead to incorrect results because
6577 it doesn't know about volatile variables, thus making it impossible to
6578 debug targets which use memory mapped I/O devices. `set remotecache
6579 off' turns the the data cache off.
6581 * Remote targets may have threads
6583 The standard remote protocol now includes support for multiple threads
6584 in the target system, using new protocol commands 'H' and 'T'. See
6585 gdb/remote.c for details.
6589 If GDB is configured with `--enable-netrom', then it will include
6590 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6591 acts as though it is a bank of ROM on the target board, but you can
6592 write into it over the network. GDB's support consists only of
6593 support for fast loading into the emulated ROM; to debug, you must use
6594 another protocol, such as standard remote protocol. The usual
6595 sequence is something like
6597 target nrom <netrom-hostname>
6599 target remote <netrom-hostname>:1235
6603 GDB now includes support for the Apple Macintosh, as a host only. It
6604 may be run as either an MPW tool or as a standalone application, and
6605 it can debug through the serial port. All the usual GDB commands are
6606 available, but to the target command, you must supply "serial" as the
6607 device type instead of "/dev/ttyXX". See mpw-README in the main
6608 directory for more information on how to build. The MPW configuration
6609 scripts */mpw-config.in support only a few targets, and only the
6610 mips-idt-ecoff target has been tested.
6614 GDB configuration now uses autoconf. This is not user-visible,
6615 but does simplify configuration and building.
6619 GDB now supports hpux10.
6621 *** Changes in GDB-4.14:
6623 * New native configurations
6625 x86 FreeBSD i[345]86-*-freebsd
6626 x86 NetBSD i[345]86-*-netbsd
6627 NS32k NetBSD ns32k-*-netbsd
6628 Sparc NetBSD sparc-*-netbsd
6632 A29K VxWorks a29k-*-vxworks
6633 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6634 CPU32 EST-300 emulator m68*-*-est*
6635 PowerPC ELF powerpc-*-elf
6638 * Alpha OSF/1 support for procfs
6640 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6641 possible to attach to running processes. As the mounting of the /proc
6642 filesystem is optional on the Alpha, GDB automatically determines
6643 the availability of /proc during startup. This can lead to problems
6644 if /proc is unmounted after GDB has been started.
6646 * Arguments to user-defined commands
6648 User commands may accept up to 10 arguments separated by whitespace.
6649 Arguments are accessed within the user command via $arg0..$arg9. A
6652 print $arg0 + $arg1 + $arg2
6654 To execute the command use:
6657 Defines the command "adder" which prints the sum of its three arguments.
6658 Note the arguments are text substitutions, so they may reference variables,
6659 use complex expressions, or even perform inferior function calls.
6661 * New `if' and `while' commands
6663 This makes it possible to write more sophisticated user-defined
6664 commands. Both commands take a single argument, which is the
6665 expression to evaluate, and must be followed by the commands to
6666 execute, one per line, if the expression is nonzero, the list being
6667 terminated by the word `end'. The `if' command list may include an
6668 `else' word, which causes the following commands to be executed only
6669 if the expression is zero.
6671 * Fortran source language mode
6673 GDB now includes partial support for Fortran 77. It will recognize
6674 Fortran programs and can evaluate a subset of Fortran expressions, but
6675 variables and functions may not be handled correctly. GDB will work
6676 with G77, but does not yet know much about symbols emitted by other
6679 * Better HPUX support
6681 Most debugging facilities now work on dynamic executables for HPPAs
6682 running hpux9 or later. You can attach to running dynamically linked
6683 processes, but by default the dynamic libraries will be read-only, so
6684 for instance you won't be able to put breakpoints in them. To change
6685 that behavior do the following before running the program:
6691 This will cause the libraries to be mapped private and read-write.
6692 To revert to the normal behavior, do this:
6698 You cannot set breakpoints or examine data in the library until after
6699 the library is loaded if the function/data symbols do not have
6702 GDB can now also read debug symbols produced by the HP C compiler on
6703 HPPAs (sorry, no C++, Fortran or 68k support).
6705 * Target byte order now dynamically selectable
6707 You can choose which byte order to use with a target system, via the
6708 commands "set endian big" and "set endian little", and you can see the
6709 current setting by using "show endian". You can also give the command
6710 "set endian auto", in which case GDB will use the byte order
6711 associated with the executable. Currently, only embedded MIPS
6712 configurations support dynamic selection of target byte order.
6714 * New DOS host serial code
6716 This version uses DPMI interrupts to handle buffered I/O, so you
6717 no longer need to run asynctsr when debugging boards connected to
6720 *** Changes in GDB-4.13:
6722 * New "complete" command
6724 This lists all the possible completions for the rest of the line, if it
6725 were to be given as a command itself. This is intended for use by emacs.
6727 * Trailing space optional in prompt
6729 "set prompt" no longer adds a space for you after the prompt you set. This
6730 allows you to set a prompt which ends in a space or one that does not.
6732 * Breakpoint hit counts
6734 "info break" now displays a count of the number of times the breakpoint
6735 has been hit. This is especially useful in conjunction with "ignore"; you
6736 can ignore a large number of breakpoint hits, look at the breakpoint info
6737 to see how many times the breakpoint was hit, then run again, ignoring one
6738 less than that number, and this will get you quickly to the last hit of
6741 * Ability to stop printing at NULL character
6743 "set print null-stop" will cause GDB to stop printing the characters of
6744 an array when the first NULL is encountered. This is useful when large
6745 arrays actually contain only short strings.
6747 * Shared library breakpoints
6749 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6750 breakpoints in shared libraries before the executable is run.
6752 * Hardware watchpoints
6754 There is a new hardware breakpoint for the watch command for sparclite
6755 targets. See gdb/sparclite/hw_breakpoint.note.
6757 Hardware watchpoints are also now supported under GNU/Linux.
6761 Annotations have been added. These are for use with graphical interfaces,
6762 and are still experimental. Currently only gdba.el uses these.
6764 * Improved Irix 5 support
6766 GDB now works properly with Irix 5.2.
6768 * Improved HPPA support
6770 GDB now works properly with the latest GCC and GAS.
6772 * New native configurations
6774 Sequent PTX4 i[34]86-sequent-ptx4
6775 HPPA running OSF/1 hppa*-*-osf*
6776 Atari TT running SVR4 m68*-*-sysv4*
6777 RS/6000 LynxOS rs6000-*-lynxos*
6781 OS/9000 i[34]86-*-os9k
6782 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6785 * Hitachi SH7000 and E7000-PC ICE support
6787 There is now support for communicating with the Hitachi E7000-PC ICE.
6788 This is available automatically when GDB is configured for the SH.
6792 As usual, a variety of small fixes and improvements, both generic
6793 and configuration-specific. See the ChangeLog for more detail.
6795 *** Changes in GDB-4.12:
6797 * Irix 5 is now supported
6801 GDB-4.12 on the HPPA has a number of changes which make it unable
6802 to debug the output from the currently released versions of GCC and
6803 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6804 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6805 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6808 *** Changes in GDB-4.11:
6810 * User visible changes:
6814 The "set remotedebug" option is now consistent between the mips remote
6815 target, remote targets using the gdb-specific protocol, UDI (AMD's
6816 debug protocol for the 29k) and the 88k bug monitor. It is now an
6817 integer specifying a debug level (normally 0 or 1, but 2 means more
6818 debugging info for the mips target).
6820 * DEC Alpha native support
6822 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6823 debug info, but GDB works fairly well with the DEC compiler and should
6824 work with a future GCC release. See the README file for a few
6825 Alpha-specific notes.
6827 * Preliminary thread implementation
6829 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6831 * LynxOS native and target support for 386
6833 This release has been hosted on LynxOS 2.2, and also can be configured
6834 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6837 * Improvements in C++ mangling/demangling.
6839 This release has much better g++ debugging, specifically in name
6840 mangling/demangling, virtual function calls, print virtual table,
6841 call methods, ...etc.
6843 *** Changes in GDB-4.10:
6845 * User visible changes:
6847 Remote debugging using the GDB-specific (`target remote') protocol now
6848 supports the `load' command. This is only useful if you have some
6849 other way of getting the stub to the target system, and you can put it
6850 somewhere in memory where it won't get clobbered by the download.
6852 Filename completion now works.
6854 When run under emacs mode, the "info line" command now causes the
6855 arrow to point to the line specified. Also, "info line" prints
6856 addresses in symbolic form (as well as hex).
6858 All vxworks based targets now support a user settable option, called
6859 vxworks-timeout. This option represents the number of seconds gdb
6860 should wait for responses to rpc's. You might want to use this if
6861 your vxworks target is, perhaps, a slow software simulator or happens
6862 to be on the far side of a thin network line.
6866 This release contains support for using a DEC alpha as a GDB host for
6867 cross debugging. Native alpha debugging is not supported yet.
6870 *** Changes in GDB-4.9:
6874 This is the first GDB release which is accompanied by a matching testsuite.
6875 The testsuite requires installation of dejagnu, which should be available
6876 via ftp from most sites that carry GNU software.
6880 'Cfront' style demangling has had its name changed to 'ARM' style, to
6881 emphasize that it was written from the specifications in the C++ Annotated
6882 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6883 disclaimers, it still generated too much confusion with users attempting to
6884 use gdb with AT&T cfront.
6888 GDB now uses a standard remote interface to a simulator library.
6889 So far, the library contains simulators for the Zilog Z8001/2, the
6890 Hitachi H8/300, H8/500 and Super-H.
6892 * New targets supported
6894 H8/300 simulator h8300-hitachi-hms or h8300hms
6895 H8/500 simulator h8500-hitachi-hms or h8500hms
6896 SH simulator sh-hitachi-hms or sh
6897 Z8000 simulator z8k-zilog-none or z8ksim
6898 IDT MIPS board over serial line mips-idt-ecoff
6900 Cross-debugging to GO32 targets is supported. It requires a custom
6901 version of the i386-stub.c module which is integrated with the
6902 GO32 memory extender.
6904 * New remote protocols
6906 MIPS remote debugging protocol.
6908 * New source languages supported
6910 This version includes preliminary support for Chill, a Pascal like language
6911 used by telecommunications companies. Chill support is also being integrated
6912 into the GNU compiler, but we don't know when it will be publically available.
6915 *** Changes in GDB-4.8:
6917 * HP Precision Architecture supported
6919 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6920 version of this support was available as a set of patches from the
6921 University of Utah. GDB does not support debugging of programs
6922 compiled with the HP compiler, because HP will not document their file
6923 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6924 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6926 Many problems in the preliminary version have been fixed.
6928 * Faster and better demangling
6930 We have improved template demangling and fixed numerous bugs in the GNU style
6931 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6932 character types (wchar_t) are now supported. Demangling of each symbol is now
6933 only done once, and is cached when the symbol table for a file is read in.
6934 This results in a small increase in memory usage for C programs, a moderate
6935 increase in memory usage for C++ programs, and a fantastic speedup in
6938 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6939 from the specifications in the Annotated Reference Manual, which AT&T's
6940 compiler does not actually implement.
6942 * G++ multiple inheritance compiler problem
6944 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6945 inheritance lattices was reworked to properly discover ambiguities. We
6946 recently found an example which causes this new algorithm to fail in a
6947 very subtle way, producing bad debug information for those classes.
6948 The file 'gcc.patch' (in this directory) can be applied to gcc to
6949 circumvent the problem. A future GCC release will contain a complete
6952 The previous G++ debug info problem (mentioned below for the gdb-4.7
6953 release) is fixed in gcc version 2.3.2.
6955 * Improved configure script
6957 The `configure' script will now attempt to guess your system type if
6958 you don't supply a host system type. The old scheme of supplying a
6959 host system triplet is preferable over using this. All the magic is
6960 done in the new `config.guess' script. Examine it for details.
6962 We have also brought our configure script much more in line with the FSF's
6963 version. It now supports the --with-xxx options. In particular,
6964 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6965 The resulting GDB will not be able to read arbitrary object file formats --
6966 only the format ``expected'' to be used on the configured target system.
6967 We hope to make this the default in a future release.
6969 * Documentation improvements
6971 There's new internal documentation on how to modify GDB, and how to
6972 produce clean changes to the code. We implore people to read it
6973 before submitting changes.
6975 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6976 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6977 `info' files are also provided. To build `info' files from scratch,
6978 you will need the latest `makeinfo' release, which will be available in
6979 a future texinfo-X.Y release.
6981 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6982 We're not sure exactly which versions have this problem, but it has
6983 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6984 or better. If that isn't possible, there is a patch in
6985 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6986 around this problem.
6990 GDB now supports array constants that can be used in expressions typed in by
6991 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6992 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6995 The new directory `gdb/sparclite' contains a program that demonstrates
6996 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6998 * New native hosts supported
7000 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7001 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7003 * New targets supported
7005 AMD 29k family via UDI a29k-amd-udi or udi29k
7007 * New file formats supported
7009 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7010 HPUX core files, and SCO 3.2v2 core files.
7014 Attaching to processes now works again; thanks for the many bug reports.
7016 We have also stomped on a bunch of core dumps caused by
7017 printf_filtered("%s") problems.
7019 We eliminated a copyright problem on the rpc and ptrace header files
7020 for VxWorks, which was discovered at the last minute during the 4.7
7021 release. You should now be able to build a VxWorks GDB.
7023 You can now interrupt gdb while an attached process is running. This
7024 will cause the attached process to stop, and give control back to GDB.
7026 We fixed problems caused by using too many file descriptors
7027 for reading symbols from object files and libraries. This was
7028 especially a problem for programs that used many (~100) shared
7031 The `step' command now only enters a subroutine if there is line number
7032 information for the subroutine. Otherwise it acts like the `next'
7033 command. Previously, `step' would enter subroutines if there was
7034 any debugging information about the routine. This avoids problems
7035 when using `cc -g1' on MIPS machines.
7037 * Internal improvements
7039 GDB's internal interfaces have been improved to make it easier to support
7040 debugging of multiple languages in the future.
7042 GDB now uses a common structure for symbol information internally.
7043 Minimal symbols (derived from linkage symbols in object files), partial
7044 symbols (from a quick scan of debug information), and full symbols
7045 contain a common subset of information, making it easier to write
7046 shared code that handles any of them.
7048 * New command line options
7050 We now accept --silent as an alias for --quiet.
7054 The memory-mapped-malloc library is now licensed under the GNU Library
7055 General Public License.
7057 *** Changes in GDB-4.7:
7059 * Host/native/target split
7061 GDB has had some major internal surgery to untangle the support for
7062 hosts and remote targets. Now, when you configure GDB for a remote
7063 target, it will no longer load in all of the support for debugging
7064 local programs on the host. When fully completed and tested, this will
7065 ensure that arbitrary host/target combinations are possible.
7067 The primary conceptual shift is to separate the non-portable code in
7068 GDB into three categories. Host specific code is required any time GDB
7069 is compiled on that host, regardless of the target. Target specific
7070 code relates to the peculiarities of the target, but can be compiled on
7071 any host. Native specific code is everything else: it can only be
7072 built when the host and target are the same system. Child process
7073 handling and core file support are two common `native' examples.
7075 GDB's use of /proc for controlling Unix child processes is now cleaner.
7076 It has been split out into a single module under the `target_ops' vector,
7077 plus two native-dependent functions for each system that uses /proc.
7079 * New hosts supported
7081 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7082 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7083 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7085 * New targets supported
7087 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7088 68030 and CPU32 m68030-*-*, m68332-*-*
7090 * New native hosts supported
7092 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7093 (386bsd is not well tested yet)
7094 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7096 * New file formats supported
7098 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7099 supports reading of `a.out.adobe' object files, which are an a.out
7100 format extended with minimal information about multiple sections.
7104 `show copying' is the same as the old `info copying'.
7105 `show warranty' is the same as `info warrantee'.
7106 These were renamed for consistency. The old commands continue to work.
7108 `info handle' is a new alias for `info signals'.
7110 You can now define pre-command hooks, which attach arbitrary command
7111 scripts to any command. The commands in the hook will be executed
7112 prior to the user's command. You can also create a hook which will be
7113 executed whenever the program stops. See gdb.texinfo.
7117 We now deal with Cfront style name mangling, and can even extract type
7118 info from mangled symbols. GDB can automatically figure out which
7119 symbol mangling style your C++ compiler uses.
7121 Calling of methods and virtual functions has been improved as well.
7125 The crash that occured when debugging Sun Ansi-C compiled binaries is
7126 fixed. This was due to mishandling of the extra N_SO stabs output
7129 We also finally got Ultrix 4.2 running in house, and fixed core file
7130 support, with help from a dozen people on the net.
7132 John M. Farrell discovered that the reason that single-stepping was so
7133 slow on all of the Mips based platforms (primarily SGI and DEC) was
7134 that we were trying to demangle and lookup a symbol used for internal
7135 purposes on every instruction that was being stepped through. Changing
7136 the name of that symbol so that it couldn't be mistaken for a C++
7137 mangled symbol sped things up a great deal.
7139 Rich Pixley sped up symbol lookups in general by getting much smarter
7140 about when C++ symbol mangling is necessary. This should make symbol
7141 completion (TAB on the command line) much faster. It's not as fast as
7142 we'd like, but it's significantly faster than gdb-4.6.
7146 A new user controllable variable 'call_scratch_address' can
7147 specify the location of a scratch area to be used when GDB
7148 calls a function in the target. This is necessary because the
7149 usual method of putting the scratch area on the stack does not work
7150 in systems that have separate instruction and data spaces.
7152 We integrated changes to support the 29k UDI (Universal Debugger
7153 Interface), but discovered at the last minute that we didn't have all
7154 of the appropriate copyright paperwork. We are working with AMD to
7155 resolve this, and hope to have it available soon.
7159 We have sped up the remote serial line protocol, especially for targets
7160 with lots of registers. It now supports a new `expedited status' ('T')
7161 message which can be used in place of the existing 'S' status message.
7162 This allows the remote stub to send only the registers that GDB
7163 needs to make a quick decision about single-stepping or conditional
7164 breakpoints, eliminating the need to fetch the entire register set for
7165 each instruction being stepped through.
7167 The GDB remote serial protocol now implements a write-through cache for
7168 registers, only re-reading the registers if the target has run.
7170 There is also a new remote serial stub for SPARC processors. You can
7171 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7172 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7173 processor with a serial port.
7177 Configure.in files have become much easier to read and modify. A new
7178 `table driven' format makes it more obvious what configurations are
7179 supported, and what files each one uses.
7183 There is a new opcodes library which will eventually contain all of the
7184 disassembly routines and opcode tables. At present, it only contains
7185 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7186 disassembler (binutils/objdump) to share these routines.
7188 The libiberty library is now copylefted under the GNU Library General
7189 Public License. This allows more liberal use, and was done so libg++
7190 can use it. This makes no difference to GDB, since the Library License
7191 grants all the rights from the General Public License.
7195 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7196 reference to the stabs symbol info used by the debugger. It is (as far
7197 as we know) the only published document on this fascinating topic. We
7198 encourage you to read it, compare it to the stabs information on your
7199 system, and send improvements on the document in general (to
7200 bug-gdb@prep.ai.mit.edu).
7202 And, of course, many bugs have been fixed.
7205 *** Changes in GDB-4.6:
7207 * Better support for C++ function names
7209 GDB now accepts as input the "demangled form" of C++ overloaded function
7210 names and member function names, and can do command completion on such names
7211 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7212 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7213 Make use of command completion, it is your friend.
7215 GDB also now accepts a variety of C++ mangled symbol formats. They are
7216 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7217 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7218 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7219 for the list of formats.
7221 * G++ symbol mangling problem
7223 Recent versions of gcc have a bug in how they emit debugging information for
7224 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7225 directory) can be applied to gcc to fix the problem. Alternatively, if you
7226 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7227 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7228 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7231 * New 'maintenance' command
7233 All of the commands related to hacking GDB internals have been moved out of
7234 the main command set, and now live behind the 'maintenance' command. This
7235 can also be abbreviated as 'mt'. The following changes were made:
7237 dump-me -> maintenance dump-me
7238 info all-breakpoints -> maintenance info breakpoints
7239 printmsyms -> maintenance print msyms
7240 printobjfiles -> maintenance print objfiles
7241 printpsyms -> maintenance print psymbols
7242 printsyms -> maintenance print symbols
7244 The following commands are new:
7246 maintenance demangle Call internal GDB demangler routine to
7247 demangle a C++ link name and prints the result.
7248 maintenance print type Print a type chain for a given symbol
7250 * Change to .gdbinit file processing
7252 We now read the $HOME/.gdbinit file before processing the argv arguments
7253 (e.g. reading symbol files or core files). This allows global parameters to
7254 be set, which will apply during the symbol reading. The ./.gdbinit is still
7255 read after argv processing.
7257 * New hosts supported
7259 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7261 GNU/Linux support i386-unknown-linux or linux
7263 We are also including code to support the HP/PA running BSD and HPUX. This
7264 is almost guaranteed not to work, as we didn't have time to test or build it
7265 for this release. We are including it so that the more adventurous (or
7266 masochistic) of you can play with it. We also had major problems with the
7267 fact that the compiler that we got from HP doesn't support the -g option.
7270 * New targets supported
7272 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7274 * More smarts about finding #include files
7276 GDB now remembers the compilation directory for all include files, and for
7277 all files from which C is generated (like yacc and lex sources). This
7278 greatly improves GDB's ability to find yacc/lex sources, and include files,
7279 especially if you are debugging your program from a directory different from
7280 the one that contains your sources.
7282 We also fixed a bug which caused difficulty with listing and setting
7283 breakpoints in include files which contain C code. (In the past, you had to
7284 try twice in order to list an include file that you hadn't looked at before.)
7286 * Interesting infernals change
7288 GDB now deals with arbitrary numbers of sections, where the symbols for each
7289 section must be relocated relative to that section's landing place in the
7290 target's address space. This work was needed to support ELF with embedded
7291 stabs used by Solaris-2.0.
7293 * Bug fixes (of course!)
7295 There have been loads of fixes for the following things:
7296 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7297 i960, stabs, DOS(GO32), procfs, etc...
7299 See the ChangeLog for details.
7301 *** Changes in GDB-4.5:
7303 * New machines supported (host and target)
7305 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7307 SGI Irix-4.x mips-sgi-irix4 or iris4
7309 * New malloc package
7311 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7312 Mmalloc is capable of handling mutiple heaps of memory. It is also
7313 capable of saving a heap to a file, and then mapping it back in later.
7314 This can be used to greatly speedup the startup of GDB by using a
7315 pre-parsed symbol table which lives in a mmalloc managed heap. For
7316 more details, please read mmalloc/mmalloc.texi.
7320 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7321 'help info proc' for details.
7323 * MIPS ecoff symbol table format
7325 The code that reads MIPS symbol table format is now supported on all hosts.
7326 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7329 * File name changes for MS-DOS
7331 Many files in the config directories have been renamed to make it easier to
7332 support GDB on MS-DOSe systems (which have very restrictive file name
7333 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7334 environment) is close to working but has some remaining problems. Note
7335 that debugging of DOS programs is not supported, due to limitations
7336 in the ``operating system'', but it can be used to host cross-debugging.
7338 * Cross byte order fixes
7340 Many fixes have been made to support cross debugging of Sparc and MIPS
7341 targets from hosts whose byte order differs.
7343 * New -mapped and -readnow options
7345 If memory-mapped files are available on your system through the 'mmap'
7346 system call, you can use the -mapped option on the `file' or
7347 `symbol-file' commands to cause GDB to write the symbols from your
7348 program into a reusable file. If the program you are debugging is
7349 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7350 Future GDB debugging sessions will notice the presence of this file,
7351 and will quickly map in symbol information from it, rather than reading
7352 the symbol table from the executable program. Using the '-mapped'
7353 option in a GDB `file' or `symbol-file' command has the same effect as
7354 starting GDB with the '-mapped' command-line option.
7356 You can cause GDB to read the entire symbol table immediately by using
7357 the '-readnow' option with any of the commands that load symbol table
7358 information (or on the GDB command line). This makes the command
7359 slower, but makes future operations faster.
7361 The -mapped and -readnow options are typically combined in order to
7362 build a `fred.syms' file that contains complete symbol information.
7363 A simple GDB invocation to do nothing but build a `.syms' file for future
7366 gdb -batch -nx -mapped -readnow programname
7368 The `.syms' file is specific to the host machine on which GDB is run.
7369 It holds an exact image of GDB's internal symbol table. It cannot be
7370 shared across multiple host platforms.
7372 * longjmp() handling
7374 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7375 siglongjmp() without losing control. This feature has not yet been ported to
7376 all systems. It currently works on many 386 platforms, all MIPS-based
7377 platforms (SGI, DECstation, etc), and Sun3/4.
7381 Preliminary work has been put in to support the new Solaris OS from Sun. At
7382 this time, it can control and debug processes, but it is not capable of
7387 As always, many many bug fixes. The major areas were with g++, and mipsread.
7388 People using the MIPS-based platforms should experience fewer mysterious
7389 crashes and trashed symbol tables.
7391 *** Changes in GDB-4.4:
7393 * New machines supported (host and target)
7395 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7397 BSD Reno on Vax vax-dec-bsd
7398 Ultrix on Vax vax-dec-ultrix
7400 * New machines supported (target)
7402 AMD 29000 embedded, using EBMON a29k-none-none
7406 GDB continues to improve its handling of C++. `References' work better.
7407 The demangler has also been improved, and now deals with symbols mangled as
7408 per the Annotated C++ Reference Guide.
7410 GDB also now handles `stabs' symbol information embedded in MIPS
7411 `ecoff' symbol tables. Since the ecoff format was not easily
7412 extensible to handle new languages such as C++, this appeared to be a
7413 good way to put C++ debugging info into MIPS binaries. This option
7414 will be supported in the GNU C compiler, version 2, when it is
7417 * New features for SVR4
7419 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7420 shared libraries. Debugging dynamically linked programs should present
7421 only minor differences from debugging statically linked programs.
7423 The `info proc' command will print out information about any process
7424 on an SVR4 system (including the one you are debugging). At the moment,
7425 it prints the address mappings of the process.
7427 If you bring up GDB on another SVR4 system, please send mail to
7428 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7430 * Better dynamic linking support in SunOS
7432 Reading symbols from shared libraries which contain debugging symbols
7433 now works properly. However, there remain issues such as automatic
7434 skipping of `transfer vector' code during function calls, which
7435 make it harder to debug code in a shared library, than to debug the
7436 same code linked statically.
7440 GDB is now using the latest `getopt' routines from the FSF. This
7441 version accepts the -- prefix for options with long names. GDB will
7442 continue to accept the old forms (-option and +option) as well.
7443 Various single letter abbreviations for options have been explicity
7444 added to the option table so that they won't get overshadowed in the
7445 future by other options that begin with the same letter.
7449 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7450 Many assorted bugs have been handled. Many more remain to be handled.
7451 See the various ChangeLog files (primarily in gdb and bfd) for details.
7454 *** Changes in GDB-4.3:
7456 * New machines supported (host and target)
7458 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7459 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7460 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7462 * Almost SCO Unix support
7464 We had hoped to support:
7465 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7466 (except for core file support), but we discovered very late in the release
7467 that it has problems with process groups that render gdb unusable. Sorry
7468 about that. I encourage people to fix it and post the fixes.
7470 * Preliminary ELF and DWARF support
7472 GDB can read ELF object files on System V Release 4, and can handle
7473 debugging records for C, in DWARF format, in ELF files. This support
7474 is preliminary. If you bring up GDB on another SVR4 system, please
7475 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7480 GDB now uses the latest `readline' library. One user-visible change
7481 is that two tabs will list possible command completions, which previously
7482 required typing M-? (meta-question mark, or ESC ?).
7486 The `stepi' bug that many of you noticed has been squashed.
7487 Many bugs in C++ have been handled. Many more remain to be handled.
7488 See the various ChangeLog files (primarily in gdb and bfd) for details.
7490 * State of the MIPS world (in case you wondered):
7492 GDB can understand the symbol tables emitted by the compilers
7493 supplied by most vendors of MIPS-based machines, including DEC. These
7494 symbol tables are in a format that essentially nobody else uses.
7496 Some versions of gcc come with an assembler post-processor called
7497 mips-tfile. This program is required if you want to do source-level
7498 debugging of gcc-compiled programs. I believe FSF does not ship
7499 mips-tfile with gcc version 1, but it will eventually come with gcc
7502 Debugging of g++ output remains a problem. g++ version 1.xx does not
7503 really support it at all. (If you're lucky, you should be able to get
7504 line numbers and stack traces to work, but no parameters or local
7505 variables.) With some work it should be possible to improve the
7508 When gcc version 2 is released, you will have somewhat better luck.
7509 However, even then you will get confusing results for inheritance and
7512 We will eventually provide full debugging of g++ output on
7513 DECstations. This will probably involve some kind of stabs-in-ecoff
7514 encapulation, but the details have not been worked out yet.
7517 *** Changes in GDB-4.2:
7519 * Improved configuration
7521 Only one copy of `configure' exists now, and it is not self-modifying.
7522 Porting BFD is simpler.
7526 The `step' and `next' commands now only stop at the first instruction
7527 of a source line. This prevents the multiple stops that used to occur
7528 in switch statements, for-loops, etc. `Step' continues to stop if a
7529 function that has debugging information is called within the line.
7533 Lots of small bugs fixed. More remain.
7535 * New host supported (not target)
7537 Intel 386 PC clone running Mach i386-none-mach
7540 *** Changes in GDB-4.1:
7542 * Multiple source language support
7544 GDB now has internal scaffolding to handle several source languages.
7545 It determines the type of each source file from its filename extension,
7546 and will switch expression parsing and number formatting to match the
7547 language of the function in the currently selected stack frame.
7548 You can also specifically set the language to be used, with
7549 `set language c' or `set language modula-2'.
7553 GDB now has preliminary support for the GNU Modula-2 compiler,
7554 currently under development at the State University of New York at
7555 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7556 continue through the fall of 1991 and into 1992.
7558 Other Modula-2 compilers are currently not supported, and attempting to
7559 debug programs compiled with them will likely result in an error as the
7560 symbol table is read. Feel free to work on it, though!
7562 There are hooks in GDB for strict type checking and range checking,
7563 in the `Modula-2 philosophy', but they do not currently work.
7567 GDB can now write to executable and core files (e.g. patch
7568 a variable's value). You must turn this switch on, specify
7569 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7570 by assigning a new value to a variable. Modifications take
7573 * Automatic SunOS shared library reading
7575 When you run your program, GDB automatically determines where its
7576 shared libraries (if any) have been loaded, and reads their symbols.
7577 The `share' command is no longer needed. This also works when
7578 examining core files.
7582 You can specify the number of lines that the `list' command shows.
7585 * New machines supported (host and target)
7587 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7588 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7589 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7591 * New hosts supported (not targets)
7593 IBM RT/PC: romp-ibm-aix or rtpc
7595 * New targets supported (not hosts)
7597 AMD 29000 embedded with COFF a29k-none-coff
7598 AMD 29000 embedded with a.out a29k-none-aout
7599 Ultracomputer remote kernel debug a29k-nyu-kern
7601 * New remote interfaces
7607 *** Changes in GDB-4.0:
7611 Wide output is wrapped at good places to make the output more readable.
7613 Gdb now supports cross-debugging from a host machine of one type to a
7614 target machine of another type. Communication with the target system
7615 is over serial lines. The ``target'' command handles connecting to the
7616 remote system; the ``load'' command will download a program into the
7617 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7618 also supports debugging of realtime processes running under VxWorks,
7619 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7620 stub on the target system.
7622 New CPUs supported include the AMD 29000 and Intel 960.
7624 GDB now reads object files and symbol tables via a ``binary file''
7625 library, which allows a single copy of GDB to debug programs of multiple
7626 object file types such as a.out and coff.
7628 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7629 refcard.dvi and refcard.ps are available to format it).
7632 * Control-Variable user interface simplified
7634 All variables that control the operation of the debugger can be set
7635 by the ``set'' command, and displayed by the ``show'' command.
7637 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7638 ``Show prompt'' produces the response:
7639 Gdb's prompt is new-gdb=>.
7641 What follows are the NEW set commands. The command ``help set'' will
7642 print a complete list of old and new set commands. ``help set FOO''
7643 will give a longer description of the variable FOO. ``show'' will show
7644 all of the variable descriptions and their current settings.
7646 confirm on/off: Enables warning questions for operations that are
7647 hard to recover from, e.g. rerunning the program while
7648 it is already running. Default is ON.
7650 editing on/off: Enables EMACS style command line editing
7651 of input. Previous lines can be recalled with
7652 control-P, the current line can be edited with control-B,
7653 you can search for commands with control-R, etc.
7656 history filename NAME: NAME is where the gdb command history
7657 will be stored. The default is .gdb_history,
7658 or the value of the environment variable
7661 history size N: The size, in commands, of the command history. The
7662 default is 256, or the value of the environment variable
7665 history save on/off: If this value is set to ON, the history file will
7666 be saved after exiting gdb. If set to OFF, the
7667 file will not be saved. The default is OFF.
7669 history expansion on/off: If this value is set to ON, then csh-like
7670 history expansion will be performed on
7671 command line input. The default is OFF.
7673 radix N: Sets the default radix for input and output. It can be set
7674 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7675 in the current radix, so "set radix 10" is always a no-op.
7677 height N: This integer value is the number of lines on a page. Default
7678 is 24, the current `stty rows'' setting, or the ``li#''
7679 setting from the termcap entry matching the environment
7682 width N: This integer value is the number of characters on a line.
7683 Default is 80, the current `stty cols'' setting, or the ``co#''
7684 setting from the termcap entry matching the environment
7687 Note: ``set screensize'' is obsolete. Use ``set height'' and
7688 ``set width'' instead.
7690 print address on/off: Print memory addresses in various command displays,
7691 such as stack traces and structure values. Gdb looks
7692 more ``symbolic'' if you turn this off; it looks more
7693 ``machine level'' with it on. Default is ON.
7695 print array on/off: Prettyprint arrays. New convenient format! Default
7698 print demangle on/off: Print C++ symbols in "source" form if on,
7701 print asm-demangle on/off: Same, for assembler level printouts
7704 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7707 * Support for Epoch Environment.
7709 The epoch environment is a version of Emacs v18 with windowing. One
7710 new command, ``inspect'', is identical to ``print'', except that if you
7711 are running in the epoch environment, the value is printed in its own
7715 * Support for Shared Libraries
7717 GDB can now debug programs and core files that use SunOS shared libraries.
7718 Symbols from a shared library cannot be referenced
7719 before the shared library has been linked with the program (this
7720 happens after you type ``run'' and before the function main() is entered).
7721 At any time after this linking (including when examining core files
7722 from dynamically linked programs), gdb reads the symbols from each
7723 shared library when you type the ``sharedlibrary'' command.
7724 It can be abbreviated ``share''.
7726 sharedlibrary REGEXP: Load shared object library symbols for files
7727 matching a unix regular expression. No argument
7728 indicates to load symbols for all shared libraries.
7730 info sharedlibrary: Status of loaded shared libraries.
7735 A watchpoint stops execution of a program whenever the value of an
7736 expression changes. Checking for this slows down execution
7737 tremendously whenever you are in the scope of the expression, but is
7738 quite useful for catching tough ``bit-spreader'' or pointer misuse
7739 problems. Some machines such as the 386 have hardware for doing this
7740 more quickly, and future versions of gdb will use this hardware.
7742 watch EXP: Set a watchpoint (breakpoint) for an expression.
7744 info watchpoints: Information about your watchpoints.
7746 delete N: Deletes watchpoint number N (same as breakpoints).
7747 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7748 enable N: Re-enables watchpoint number N (same as breakpoints).
7751 * C++ multiple inheritance
7753 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7756 * C++ exception handling
7758 Gdb now supports limited C++ exception handling. Besides the existing
7759 ability to breakpoint on an exception handler, gdb can breakpoint on
7760 the raising of an exception (before the stack is peeled back to the
7763 catch FOO: If there is a FOO exception handler in the dynamic scope,
7764 set a breakpoint to catch exceptions which may be raised there.
7765 Multiple exceptions (``catch foo bar baz'') may be caught.
7767 info catch: Lists all exceptions which may be caught in the
7768 current stack frame.
7771 * Minor command changes
7773 The command ``call func (arg, arg, ...)'' now acts like the print
7774 command, except it does not print or save a value if the function's result
7775 is void. This is similar to dbx usage.
7777 The ``up'' and ``down'' commands now always print the frame they end up
7778 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7779 frames without printing.
7781 * New directory command
7783 'dir' now adds directories to the FRONT of the source search path.
7784 The path starts off empty. Source files that contain debug information
7785 about the directory in which they were compiled can be found even
7786 with an empty path; Sun CC and GCC include this information. If GDB can't
7787 find your source file in the current directory, type "dir .".
7789 * Configuring GDB for compilation
7791 For normal use, type ``./configure host''. See README or gdb.texinfo
7794 GDB now handles cross debugging. If you are remotely debugging between
7795 two different machines, type ``./configure host -target=targ''.
7796 Host is the machine where GDB will run; targ is the machine
7797 where the program that you are debugging will run.