1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 10
6 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
11 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
13 The MI -break-insert and -dprintf-insert commands now support a
14 new "--qualified" option that makes GDB interpret a specified
15 function name as a complete fully-qualified name. This is the
16 equivalent of the CLI's "break -qualified" and "dprintf
19 * GDB now supports core file debugging for x86_64 Cygwin programs.
21 * GDB will now look for the .gdbinit file in a config directory before
22 looking for ~/.gdbinit. The file is searched for in the following
23 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
24 $HOME/.gdbinit. On Apple hosts the search order is instead:
25 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
27 * GDB now supports fixed point types which are described in DWARF
28 as base types with a fixed-point encoding. Additionally, support
29 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
32 For Ada, this allows support for fixed point types without requiring
33 the use of the GNAT encoding (based on information added to the type's
34 name following a GNAT-specific format).
40 Control the display of debug output about GDB's event loop.
42 maintenance flush symbol-cache
43 maintenance flush register-cache
44 These new commands are equivalent to the already existing commands
45 'maintenance flush-symbol-cache' and 'flushregs' respectively.
47 maintenance flush dcache
48 A new command to flush the dcache.
52 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
53 [-force-condition] [if CONDITION]
54 This command would previously refuse setting a breakpoint if the
55 CONDITION expression is invalid at a location. It now accepts and
56 defines the breakpoint if there is at least one location at which
57 the CONDITION is valid. The locations for which the CONDITION is
58 invalid, are automatically disabled. If CONDITION is invalid at all
59 of the locations, setting the breakpoint is still rejected. However,
60 the '-force-condition' flag can be used in this case for forcing GDB to
61 define the breakpoint, making all the current locations automatically
62 disabled. This may be useful if the user knows the condition will
63 become meaningful at a future location, e.g. due to a shared library
66 condition [-force] N COND
67 The behavior of this command is changed the same way for the 'break'
68 command as explained above. The '-force' flag can be used to force
69 GDB into defining the condition even when COND is invalid for all the
70 current locations of breakpoint N.
73 maintenance flush-symbol-cache
74 These commands are deprecated in favor of the new commands
75 'maintenance flush register-cache' and 'maintenance flush
76 symbol-cache' respectively.
78 set style version foreground COLOR
79 set style version background COLOR
80 set style version intensity VALUE
81 Control the styling of GDB's version number text.
85 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
86 and "org.gnu.gdb.arc.aux". The old names are still supported but
87 must be considered obsolete. They will be deprecated after some
90 * Help and apropos commands will now show the documentation of a
91 command only once, even if that command has one or more aliases.
92 These commands now show the command name, then all of its aliases,
93 and finally the description of the command.
95 * 'help aliases' now shows only the user defined aliases. GDB predefined
96 aliases are shown together with their aliased command.
98 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
99 debugging information as well as source code.
101 When built with debuginfod, GDB can automatically query debuginfod
102 servers for the separate debug files and source code of the executable
105 To build GDB with debuginfod, pass --with-debuginfod to configure (this
106 requires libdebuginfod, the debuginfod client library).
108 debuginfod is distributed with elfutils, starting with version 0.178.
110 You can get the latest version from https://sourceware.org/elfutils.
112 * Multi-target debugging support
114 GDB now supports debugging multiple target connections
115 simultaneously. For example, you can now have each inferior
116 connected to different remote servers running in different machines,
117 or have one inferior debugging a local native process, an inferior
118 debugging a core dump, etc.
120 This support is experimental and comes with some limitations -- you
121 can only resume multiple targets simultaneously if all targets
122 support non-stop mode, and all remote stubs or servers must support
123 the same set of remote protocol features exactly. See also "info
124 connections" and "add-inferior -no-connection" below, and "maint set
125 target-non-stop" in the user manual.
127 * New features in the GDB remote stub, GDBserver
129 ** GDBserver is now supported on ARC GNU/Linux.
131 ** GDBserver is now supported on RISC-V GNU/Linux.
133 ** GDBserver no longer supports these host triplets:
144 i[34567]86-*-mingw32ce*
146 * Debugging MS-Windows processes now sets $_exitsignal when the
147 inferior is terminated by a signal, instead of setting $_exitcode.
149 * Multithreaded symbol loading has now been enabled by default on systems
150 that support it (see entry for GDB 9, below), providing faster
151 performance for programs with many symbols.
153 * The $_siginfo convenience variable now also works on Windows targets,
154 and will display the EXCEPTION_RECORD of the last handled exception.
156 * TUI windows can now be arranged horizontally.
158 * The command history filename can now be set to the empty string
159 either using 'set history filename' or by setting 'GDBHISTFILE=' in
160 the environment. The effect of setting this filename to the empty
161 string is that GDB will not try to load any previous command
164 * On Windows targets, it is now possible to debug 32-bit programs with a
169 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
170 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
171 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
172 running process, this new option indicates whether to detect
173 a mismatch between the current executable file loaded by GDB and the
174 executable file used to start the process. If 'ask', the default,
175 display a warning and ask the user whether to load the process
176 executable file; if 'warn', just display a warning; if 'off', don't
177 attempt to detect a mismatch.
179 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
180 Define a new TUI layout, specifying its name and the windows that
183 maintenance print xml-tdesc [FILE]
184 Prints the current target description as an XML document. If the
185 optional FILE is provided (which is an XML target description) then
186 the target description is read from FILE into GDB, and then
189 maintenance print core-file-backed-mappings
190 Prints file-backed mappings loaded from a core file's note section.
191 Output is expected to be similar to that of "info proc mappings".
193 set debug fortran-array-slicing on|off
194 show debug fortran-array-slicing
195 Print debugging when taking slices of Fortran arrays.
197 set fortran repack-array-slices on|off
198 show fortran repack-array-slices
199 When taking slices from Fortran arrays and strings, if the slice is
200 non-contiguous within the original value then, when this option is
201 on, the new value will be repacked into a single contiguous value.
202 When this option is off, then the value returned will consist of a
203 descriptor that describes the slice within the memory of the
204 original parent value.
208 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
209 The alias command can now specify default args for an alias.
210 GDB automatically prepends the alias default args to the argument list
211 provided explicitly by the user.
212 For example, to have a backtrace with full details, you can define
214 'alias bt_ALL = backtrace -entry-values both -frame-arg all
215 -past-main -past-entry -full'.
216 Alias default arguments can also use a set of nested 'with' commands,
217 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
218 defines the alias pp10 that will pretty print a maximum of 10 elements
219 of the given expression (if the expression is an array).
223 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
228 ** gdb.register_window_type can be used to implement new TUI windows
231 ** Dynamic types can now be queried. gdb.Type has a new attribute,
232 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
233 field of a dynamic type may have None for its "bitpos" attribute
236 ** Commands written in Python can be in the "TUI" help class by
237 registering with the new constant gdb.COMMAND_TUI.
239 ** New method gdb.PendingFrame.architecture () to retrieve the
240 architecture of the pending frame.
242 ** New gdb.Architecture.registers method that returns a
243 gdb.RegisterDescriptorIterator object, an iterator that returns
244 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
245 way to query the registers available for an architecture.
247 ** New gdb.Architecture.register_groups method that returns a
248 gdb.RegisterGroupIterator object, an iterator that returns
249 gdb.RegisterGroup objects. The new RegisterGroup is a way to
250 discover the available register groups.
254 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
256 ** Procedures 'memory-port-read-buffer-size',
257 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
258 and 'set-memory-port-write-buffer-size!' are deprecated. When
259 using Guile 2.2 and later, users who need to control the size of
260 a memory port's internal buffer can use the 'setvbuf' procedure.
264 * 'thread-exited' event is now available in the annotations interface.
266 * New built-in convenience variables $_gdb_major and $_gdb_minor
267 provide the GDB version. They are handy for conditionally using
268 features available only in or since specific GDB versions, in
269 scripts that should work error-free with many different versions,
270 such as in system-wide init files.
272 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
273 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
274 of the GDB settings and the GDB maintenance settings. They are handy
275 for changing the logic of user defined commands depending on the
276 current GDB settings.
278 * GDB now supports Thread Local Storage (TLS) variables on several
279 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
280 architectures require kernel changes. TLS is not yet supported for
281 amd64 and i386 process core dumps.
283 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
284 addresses that required unmasking are shown in the backtrace with the
287 * Two new convenience functions $_cimag and $_creal that extract the
288 imaginary and real parts respectively from complex numbers.
290 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
291 provide the exitcode or exit status of the shell commands launched by
292 GDB commands such as "shell", "pipe" and "make".
294 * The command define-prefix can now define user defined prefix commands.
295 User defined commands can now be defined using these user defined prefix
298 * Command names can now use the . character.
300 * The RX port now supports XML target descriptions.
302 * GDB now shows the Ada task names at more places, e.g. in task switching
305 * GDB can now be compiled with Python 3 on Windows.
307 * New convenience variable $_ada_exception holds the address of the
308 Ada exception being thrown. This is set by Ada-related catchpoints.
310 * GDB can now place breakpoints on nested functions and subroutines in
311 Fortran code. The '::' operator can be used between parent and
312 child scopes when placing breakpoints, for example:
314 (gdb) break outer_function::inner_function
316 The 'outer_function::' prefix is only needed if 'inner_function' is
317 not visible in the current scope.
319 * In addition to the system-wide gdbinit file, if configured with
320 --with-system-gdbinit-dir, GDB will now also load files in that directory
321 as system gdbinit files, unless the -nx or -n flag is provided. Files
322 with extensions .gdb, .py and .scm are supported as long as GDB was
323 compiled with support for that language.
325 * GDB now supports multithreaded symbol loading for higher performance.
326 This feature is still in testing, so it is disabled by default. You
327 can turn it on using 'maint set worker-threads unlimited'.
331 ** The gdb.Value type has a new method 'format_string' which returns a
332 string representing the value. The formatting is controlled by the
333 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
334 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
335 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
337 ** gdb.Type has a new property 'objfile' which returns the objfile the
340 ** The frame information printed by the python frame filtering code
341 is now consistent with what the 'backtrace' command prints when
342 there are no filters, or when the 'backtrace' '-no-filters' option
345 ** The new function gdb.lookup_static_symbol can be used to look up
346 symbols with static linkage.
348 ** The new function gdb.lookup_static_symbols can be used to look up
349 all static symbols with static linkage.
351 ** gdb.Objfile has new methods 'lookup_global_symbol' and
352 'lookup_static_symbol' to lookup a symbol from this objfile only.
354 ** gdb.Block now supports the dictionary syntax for accessing symbols in
355 this block (e.g. block['local_variable']).
359 | [COMMAND] | SHELL_COMMAND
360 | -d DELIM COMMAND DELIM SHELL_COMMAND
361 pipe [COMMAND] | SHELL_COMMAND
362 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
363 Executes COMMAND and sends its output to SHELL_COMMAND.
364 With no COMMAND, repeat the last executed command
365 and send its output to SHELL_COMMAND.
367 define-prefix COMMAND
368 Define or mark a command as a user-defined prefix command.
370 with SETTING [VALUE] [-- COMMAND]
371 w SETTING [VALUE] [-- COMMAND]
372 Temporarily set SETTING, run COMMAND, and restore SETTING.
373 Usage: with SETTING -- COMMAND
374 With no COMMAND, repeats the last executed command.
375 SETTING is any GDB setting you can change with the "set"
376 subcommands. For example, 'with language c -- print someobj'
377 temporarily switches to the C language in order to print someobj.
378 Settings can be combined: 'w lang c -- w print elements unlimited --
379 usercmd' switches to the C language and runs usercmd with no limit
380 of array elements to print.
382 maint with SETTING [VALUE] [-- COMMAND]
383 Like "with", but works with "maintenance set" settings.
385 set may-call-functions [on|off]
386 show may-call-functions
387 This controls whether GDB will attempt to call functions in
388 the program, such as with expressions in the print command. It
389 defaults to on. Calling functions in the program being debugged
390 can have undesired side effects. It is now possible to forbid
391 such function calls. If function calls are forbidden, GDB will throw
392 an error when a command (such as print expression) calls a function
395 set print finish [on|off]
397 This controls whether the `finish' command will display the value
398 that is returned by the current function. When `off', the value is
399 still entered into the value history, but it is not printed. The
404 Allows deeply nested structures to be simplified when printing by
405 replacing deeply nested parts (beyond the max-depth) with ellipses.
406 The default max-depth is 20, but this can be set to unlimited to get
407 the old behavior back.
409 set print raw-values [on|off]
410 show print raw-values
411 By default, GDB applies the enabled pretty printers when printing a
412 value. This allows to ignore the enabled pretty printers for a series
413 of commands. The default is 'off'.
415 set logging debugredirect [on|off]
416 By default, GDB debug output will go to both the terminal and the logfile.
417 Set if you want debug output to go only to the log file.
419 set style title foreground COLOR
420 set style title background COLOR
421 set style title intensity VALUE
422 Control the styling of titles.
424 set style highlight foreground COLOR
425 set style highlight background COLOR
426 set style highlight intensity VALUE
427 Control the styling of highlightings.
429 maint set worker-threads
430 maint show worker-threads
431 Control the number of worker threads that can be used by GDB. The
432 default is 0. "unlimited" lets GDB choose a number that is
433 reasonable. Currently worker threads are only used when demangling
434 the names of linker symbols.
436 set style tui-border foreground COLOR
437 set style tui-border background COLOR
438 Control the styling of TUI borders.
440 set style tui-active-border foreground COLOR
441 set style tui-active-border background COLOR
442 Control the styling of the active TUI border.
444 maint set test-settings KIND
445 maint show test-settings KIND
446 A set of commands used by the testsuite for exercising the settings
449 maint set tui-resize-message [on|off]
450 maint show tui-resize-message
451 Control whether GDB prints a message each time the terminal is
452 resized when in TUI mode. This is primarily useful for testing the
455 set print frame-info [short-location|location|location-and-address
456 |source-and-location|source-line|auto]
457 show print frame-info
458 This controls what frame information is printed by the commands printing
459 a frame. This setting will e.g. influence the behaviour of 'backtrace',
460 'frame', 'stepi'. The python frame filtering also respect this setting.
461 The 'backtrace' '-frame-info' option can override this global setting.
463 set tui compact-source
464 show tui compact-source
466 Enable the "compact" display mode for the TUI source window. The
467 compact display uses only as much space as is needed for the line
468 numbers in the current file, and only a single space to separate the
469 line numbers from the source.
471 info modules [-q] [REGEXP]
472 Return a list of Fortran modules matching REGEXP, or all modules if
475 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
476 Return a list of functions within all modules, grouped by module.
477 The list of functions can be restricted with the optional regular
478 expressions. MODULE_REGEXP matches against the module name,
479 TYPE_REGEXP matches against the function type signature, and REGEXP
480 matches against the function name.
482 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
483 Return a list of variables within all modules, grouped by module.
484 The list of variables can be restricted with the optional regular
485 expressions. MODULE_REGEXP matches against the module name,
486 TYPE_REGEXP matches against the variable type, and REGEXP matches
487 against the variable name.
489 set debug remote-packet-max-chars
490 show debug remote-packet-max-chars
491 Controls the number of characters to output in a remote packet when using
493 The default is 512 bytes.
496 Lists the target connections currently in use.
501 The "help" command uses the title style to enhance the
502 readibility of its output by styling the classes and
506 Similarly to "help", the "apropos" command also uses the
507 title style for the command names. "apropos" accepts now
508 a flag "-v" (verbose) to show the full documentation
509 of matching commands and to use the highlight style to mark
510 the documentation parts matching REGEXP.
514 The GDB printf and eval commands can now print C-style and Ada-style
515 string convenience variables without calling functions in the program.
516 This allows to do formatted printing of strings without having
517 a running inferior, or when debugging a core dump.
519 info sources [-dirname | -basename] [--] [REGEXP]
520 This command has now optional arguments to only print the files
521 whose names match REGEXP. The arguments -dirname and -basename
522 allow to restrict matching respectively to the dirname and basename
526 The "show style" and its subcommands are now styling
527 a style name in their output using its own style, to help
528 the user visualize the different styles.
530 set print frame-arguments
531 The new value 'presence' indicates to only indicate the presence of
532 arguments using ..., instead of printing argument names and values.
534 set print raw-frame-arguments
535 show print raw-frame-arguments
537 These commands replace the similarly-named "set/show print raw
538 frame-arguments" commands (now with a dash instead of a space). The
539 old commands are now deprecated and may be removed in a future
542 add-inferior [-no-connection]
543 The add-inferior command now supports a "-no-connection" flag that
544 makes the new inferior start with no target connection associated.
545 By default, the new inferior inherits the target connection of the
546 current inferior. See also "info connections".
549 This command's output now includes a new "Connection" column
550 indicating which target connection an inferior is bound to. See
551 "info connections" above.
553 maint test-options require-delimiter
554 maint test-options unknown-is-error
555 maint test-options unknown-is-operand
556 maint show test-options-completion-result
557 Commands used by the testsuite to validate the command options
560 focus, winheight, +, -, >, <
561 These commands are now case-sensitive.
563 * New command options, command completion
565 GDB now has a standard infrastructure to support dash-style command
566 options ('-OPT'). One benefit is that commands that use it can
567 easily support completion of command line arguments. Try "CMD
568 -[TAB]" or "help CMD" to find options supported by a command. Over
569 time, we intend to migrate most commands to this infrastructure. A
570 number of commands got support for new command options in this
573 ** The "print" and "compile print" commands now support a number of
574 options that allow overriding relevant global print settings as
575 set by "set print" subcommands:
579 -array-indexes [on|off]
580 -elements NUMBER|unlimited
585 -repeats NUMBER|unlimited
586 -static-members [on|off]
591 Note that because the "print"/"compile print" commands accept
592 arbitrary expressions which may look like options (including
593 abbreviations), if you specify any command option, then you must
594 use a double dash ("--") to mark the end of argument processing.
596 ** The "backtrace" command now supports a number of options that
597 allow overriding relevant global print settings as set by "set
598 backtrace" and "set print" subcommands:
600 -entry-values no|only|preferred|if-needed|both|compact|default
601 -frame-arguments all|scalars|none
602 -raw-frame-arguments [on|off]
603 -frame-info auto|source-line|location|source-and-location
604 |location-and-address|short-location
608 In addition, the full/no-filters/hide qualifiers are now also
609 exposed as command options too:
615 ** The "frame apply", "tfaas" and "faas" commands similarly now
616 support the following options:
621 ** The new "info sources" options -dirname and -basename options
622 are using the standard '-OPT' infrastructure.
624 All options above can also be abbreviated. The argument of boolean
625 (on/off) options can be 0/1 too, and also the argument is assumed
626 "on" if omitted. This allows writing compact command invocations,
629 (gdb) p -ra -p -o 0 -- *myptr
631 The above is equivalent to:
633 (gdb) print -raw-values -pretty -object off -- *myptr
635 ** The "info types" command now supports the '-q' flag to disable
636 printing of some header information in a similar fashion to "info
637 variables" and "info functions".
639 ** The "info variables", "info functions", and "whereis" commands
640 now take a '-n' flag that excludes non-debug symbols (symbols
641 from the symbol table, not from the debug info such as DWARF)
644 * Completion improvements
646 ** GDB can now complete the options of the "thread apply all" and
647 "taas" commands, and their "-ascending" option can now be
650 ** GDB can now complete the options of the "info threads", "info
651 functions", "info variables", "info locals", and "info args"
654 ** GDB can now complete the options of the "compile file" and
655 "compile code" commands. The "compile file" command now
656 completes on filenames.
658 ** GDB can now complete the backtrace command's
659 "full/no-filters/hide" qualifiers.
661 * In settings, you can now abbreviate "unlimited".
663 E.g., "set print elements u" is now equivalent to "set print
669 This lists all the possible completions for the rest of the line, if it
670 were to be given as a command itself. This is intended for use by MI
671 frontends in cases when separate CLI and MI channels cannot be used.
673 -catch-throw, -catch-rethrow, and -catch-catch
674 These can be used to catch C++ exceptions in a similar fashion to
675 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
677 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
678 These commands are the MI equivalent of the CLI commands 'info
679 functions', 'info types', and 'info variables' respectively.
681 -symbol-info-modules, this is the MI equivalent of the CLI 'info
684 -symbol-info-module-functions and -symbol-info-module-variables.
685 These commands are the MI equivalent of the CLI commands 'info
686 module functions' and 'info module variables'.
690 ** The default version of the MI interpreter is now 3 (-i=mi3).
692 ** The output of information about multi-location breakpoints (which is
693 syntactically incorrect in MI 2) has changed in MI 3. This affects
694 the following commands and events:
698 - =breakpoint-created
699 - =breakpoint-modified
701 The -fix-multi-location-breakpoint-output command can be used to enable
702 this behavior with previous MI versions.
704 ** Backtraces and frames include a new optional field addr_flags which is
705 given after the addr field. On AArch64 this contains PAC if the address
706 has been masked in the frame. On all other targets the field is not
711 The testsuite now creates the files gdb.cmd (containing the arguments
712 used to launch GDB) and gdb.in (containing all the commands sent to
713 GDB) in the output directory for each test script. Multiple invocations
714 are appended with .1, .2, .3 etc.
716 * Building GDB and GDBserver now requires GNU make >= 3.82.
718 Using another implementation of the make program or an earlier version of
719 GNU make to build GDB or GDBserver is not supported.
721 * Building GDB now requires GNU readline >= 7.0.
723 GDB now bundles GNU readline 8.0, but if you choose to use
724 --with-system-readline, only readline >= 7.0 can be used.
726 * The TUI SingleKey keymap is now named "SingleKey". This can be used
727 from .inputrc to bind keys in this keymap. This feature is only
728 available when gdb is built against GNU readline 8.0 or later.
730 * Removed targets and native configurations
732 GDB no longer supports debugging the Cell Broadband Engine. This includes
733 both debugging standalone Cell/B.E. SPU applications and integrated debugging
734 of Cell/B.E. applications that use both the PPU and SPU architectures.
740 * Removed targets and native configurations
742 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
745 *** Changes in GDB 8.3
747 * GDB and GDBserver now support access to additional registers on
748 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
751 * GDB now has experimental support for the compilation and injection of
752 C++ source code into the inferior. This beta release does not include
753 support for several language features, such as templates, constructors,
756 This feature requires GCC 7.1 or higher built with libcp1.so
759 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
760 can be passed using the '[ADDRESS]:PORT' notation, or the regular
761 'ADDRESS:PORT' method.
763 * DWARF index cache: GDB can now automatically save indices of DWARF
764 symbols on disk to speed up further loading of the same binaries.
766 * Ada task switching is now supported on aarch64-elf targets when
767 debugging a program using the Ravenscar Profile. For more information,
768 see the "Tasking Support when using the Ravenscar Profile" section
769 in the GDB user manual.
771 * GDB in batch mode now exits with status 1 if the last command to be
774 * The RISC-V target now supports target descriptions.
776 * System call catchpoints now support system call aliases on FreeBSD.
777 When the ABI of a system call changes in FreeBSD, this is
778 implemented by leaving a compatibility system call using the old ABI
779 at the existing number and allocating a new system call number for
780 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
781 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
782 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
783 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
784 so that a system call catchpoint for the 'kevent' system call will
785 catch invocations of both the 'kevent' and 'freebsd11_kevent'
786 binaries. This ensures that 'kevent' system calls are caught for
787 binaries using either the old or new ABIs.
789 * Terminal styling is now available for the CLI and the TUI. GNU
790 Source Highlight can additionally be used to provide styling of
791 source code snippets. See the "set style" commands, below, for more
794 * Removed support for old demangling styles arm, edg, gnu, hp and
799 set debug compile-cplus-types
800 show debug compile-cplus-types
801 Control the display of debug output about type conversion in the
802 C++ compile feature. Commands have no effect while compiling
807 Control whether debug output about files/functions skipping is
810 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
811 Apply a command to some frames.
812 FLAG arguments allow to control what output to produce and how to handle
813 errors raised when applying COMMAND to a frame.
816 Apply a command to all threads (ignoring errors and empty output).
817 Shortcut for 'thread apply all -s COMMAND'.
820 Apply a command to all frames (ignoring errors and empty output).
821 Shortcut for 'frame apply all -s COMMAND'.
824 Apply a command to all frames of all threads (ignoring errors and empty
826 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
828 maint set dwarf unwinders (on|off)
829 maint show dwarf unwinders
830 Control whether DWARF unwinders can be used.
833 Display a list of open files for a process.
837 Changes to the "frame", "select-frame", and "info frame" CLI commands.
838 These commands all now take a frame specification which
839 is either a frame level, or one of the keywords 'level', 'address',
840 'function', or 'view' followed by a parameter. Selecting a frame by
841 address, or viewing a frame outside the current backtrace now
842 requires the use of a keyword. Selecting a frame by level is
843 unchanged. The MI comment "-stack-select-frame" is unchanged.
845 target remote FILENAME
846 target extended-remote FILENAME
847 If FILENAME is a Unix domain socket, GDB will attempt to connect
848 to this socket instead of opening FILENAME as a character device.
850 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
851 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
852 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
853 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
854 These commands can now print only the searched entities
855 matching the provided regexp(s), giving a condition
856 on the entity names or entity types. The flag -q disables
857 printing headers or informations messages.
863 These commands now determine the syntax for the shown entities
864 according to the language chosen by `set language'. In particular,
865 `set language auto' means to automatically choose the language of
868 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
869 The 'thread apply' command accepts new FLAG arguments.
870 FLAG arguments allow to control what output to produce and how to handle
871 errors raised when applying COMMAND to a thread.
873 set tui tab-width NCHARS
874 show tui tab-width NCHARS
875 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
877 set style enabled [on|off]
879 Enable or disable terminal styling. Styling is enabled by default
880 on most hosts, but disabled by default when in batch mode.
882 set style sources [on|off]
884 Enable or disable source code styling. Source code styling is
885 enabled by default, but only takes effect if styling in general is
886 enabled, and if GDB was linked with GNU Source Highlight.
888 set style filename foreground COLOR
889 set style filename background COLOR
890 set style filename intensity VALUE
891 Control the styling of file names.
893 set style function foreground COLOR
894 set style function background COLOR
895 set style function intensity VALUE
896 Control the styling of function names.
898 set style variable foreground COLOR
899 set style variable background COLOR
900 set style variable intensity VALUE
901 Control the styling of variable names.
903 set style address foreground COLOR
904 set style address background COLOR
905 set style address intensity VALUE
906 Control the styling of addresses.
910 ** The '-data-disassemble' MI command now accepts an '-a' option to
911 disassemble the whole function surrounding the given program
912 counter value or function name. Support for this feature can be
913 verified by using the "-list-features" command, which should
914 contain "data-disassemble-a-option".
916 ** Command responses and notifications that include a frame now include
917 the frame's architecture in a new "arch" attribute.
919 * New native configurations
921 GNU/Linux/RISC-V riscv*-*-linux*
922 FreeBSD/riscv riscv*-*-freebsd*
926 GNU/Linux/RISC-V riscv*-*-linux*
928 CSKY GNU/LINUX csky*-*-linux
929 FreeBSD/riscv riscv*-*-freebsd*
931 GNU/Linux/OpenRISC or1k*-*-linux*
935 GDB no longer supports native debugging on versions of MS-Windows
940 ** GDB no longer supports Python versions less than 2.6.
942 ** The gdb.Inferior type has a new 'progspace' property, which is the program
943 space associated to that inferior.
945 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
946 of objfiles associated to that program space.
948 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
949 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
952 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
953 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
954 correct and did not work properly.
956 ** The gdb.Value type has a new constructor, which is used to construct a
957 gdb.Value from a Python buffer object and a gdb.Type.
963 Enable or disable the undefined behavior sanitizer. This is
964 disabled by default, but passing --enable-ubsan=yes or
965 --enable-ubsan=auto to configure will enable it. Enabling this can
966 cause a performance penalty. The undefined behavior sanitizer was
967 first introduced in GCC 4.9.
969 *** Changes in GDB 8.2
971 * The 'set disassembler-options' command now supports specifying options
974 * The 'symbol-file' command now accepts an '-o' option to add a relative
975 offset to all sections.
977 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
978 a relative offset to all sections, but it allows to override the load
979 address of individual sections using '-s'.
981 * The 'add-symbol-file' command no longer requires the second argument
982 (address of the text section).
984 * The endianness used with the 'set endian auto' mode in the absence of
985 an executable selected for debugging is now the last endianness chosen
986 either by one of the 'set endian big' and 'set endian little' commands
987 or by inferring from the last executable used, rather than the startup
990 * The pager now allows a "c" response, meaning to disable the pager
991 for the rest of the current command.
993 * The commands 'info variables/functions/types' now show the source line
994 numbers of symbol definitions when available.
996 * 'info proc' now works on running processes on FreeBSD systems and core
997 files created on FreeBSD systems.
999 * C expressions can now use _Alignof, and C++ expressions can now use
1002 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1003 the vector length while the process is running.
1009 Control display of debugging info regarding the FreeBSD native target.
1011 set|show varsize-limit
1012 This new setting allows the user to control the maximum size of Ada
1013 objects being printed when those objects have a variable type,
1014 instead of that maximum size being hardcoded to 65536 bytes.
1016 set|show record btrace cpu
1017 Controls the processor to be used for enabling errata workarounds for
1018 branch trace decode.
1020 maint check libthread-db
1021 Run integrity checks on the current inferior's thread debugging
1024 maint set check-libthread-db (on|off)
1025 maint show check-libthread-db
1026 Control whether to run integrity checks on inferior specific thread
1027 debugging libraries as they are loaded. The default is not to
1028 perform such checks.
1032 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1034 ** The commands attached to a breakpoint can be set by assigning to
1035 the breakpoint's "commands" field.
1037 ** gdb.execute can now execute multi-line gdb commands.
1039 ** The new functions gdb.convenience_variable and
1040 gdb.set_convenience_variable can be used to get and set the value
1041 of convenience variables.
1043 ** A gdb.Parameter will no longer print the "set" help text on an
1044 ordinary "set"; instead by default a "set" will be silent unless
1045 the get_set_string method returns a non-empty string.
1049 RiscV ELF riscv*-*-elf
1051 * Removed targets and native configurations
1053 m88k running OpenBSD m88*-*-openbsd*
1054 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1055 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1056 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1058 * Aarch64/Linux hardware watchpoints improvements
1060 Hardware watchpoints on unaligned addresses are now properly
1061 supported when running Linux kernel 4.10 or higher: read and access
1062 watchpoints are no longer spuriously missed, and all watchpoints
1063 lengths between 1 and 8 bytes are supported. On older kernels,
1064 watchpoints set on unaligned addresses are no longer missed, with
1065 the tradeoff that there is a possibility of false hits being
1070 --enable-codesign=CERT
1071 This can be used to invoke "codesign -s CERT" after building gdb.
1072 This option is useful on macOS, where code signing is required for
1073 gdb to work properly.
1075 --disable-gdbcli has been removed
1076 This is now silently accepted, but does nothing.
1078 *** Changes in GDB 8.1
1080 * GDB now supports dynamically creating arbitrary register groups specified
1081 in XML target descriptions. This allows for finer grain grouping of
1082 registers on systems with a large amount of registers.
1084 * The 'ptype' command now accepts a '/o' flag, which prints the
1085 offsets and sizes of fields in a struct, like the pahole(1) tool.
1087 * New "--readnever" command line option instructs GDB to not read each
1088 symbol file's symbolic debug information. This makes startup faster
1089 but at the expense of not being able to perform symbolic debugging.
1090 This option is intended for use cases where symbolic debugging will
1091 not be used, e.g., when you only need to dump the debuggee's core.
1093 * GDB now uses the GNU MPFR library, if available, to emulate target
1094 floating-point arithmetic during expression evaluation when the target
1095 uses different floating-point formats than the host. At least version
1096 3.1 of GNU MPFR is required.
1098 * GDB now supports access to the guarded-storage-control registers and the
1099 software-based guarded-storage broadcast control registers on IBM z14.
1101 * On Unix systems, GDB now supports transmitting environment variables
1102 that are to be set or unset to GDBserver. These variables will
1103 affect the environment to be passed to the remote inferior.
1105 To inform GDB of environment variables that are to be transmitted to
1106 GDBserver, use the "set environment" command. Only user set
1107 environment variables are sent to GDBserver.
1109 To inform GDB of environment variables that are to be unset before
1110 the remote inferior is started by the GDBserver, use the "unset
1111 environment" command.
1113 * Completion improvements
1115 ** GDB can now complete function parameters in linespecs and
1116 explicit locations without quoting. When setting breakpoints,
1117 quoting around functions names to help with TAB-completion is
1118 generally no longer necessary. For example, this now completes
1121 (gdb) b function(in[TAB]
1122 (gdb) b function(int)
1124 Related, GDB is no longer confused with completing functions in
1125 C++ anonymous namespaces:
1128 (gdb) b (anonymous namespace)::[TAB][TAB]
1129 (anonymous namespace)::a_function()
1130 (anonymous namespace)::b_function()
1132 ** GDB now has much improved linespec and explicit locations TAB
1133 completion support, that better understands what you're
1134 completing and offers better suggestions. For example, GDB no
1135 longer offers data symbols as possible completions when you're
1136 setting a breakpoint.
1138 ** GDB now TAB-completes label symbol names.
1140 ** The "complete" command now mimics TAB completion accurately.
1142 * New command line options (gcore)
1145 Dump all memory mappings.
1147 * Breakpoints on C++ functions are now set on all scopes by default
1149 By default, breakpoints on functions/methods are now interpreted as
1150 specifying all functions with the given name ignoring missing
1151 leading scopes (namespaces and classes).
1153 For example, assuming a C++ program with symbols named:
1158 both commands "break func()" and "break B::func()" set a breakpoint
1161 You can use the new flag "-qualified" to override this. This makes
1162 GDB interpret the specified function name as a complete
1163 fully-qualified name instead. For example, using the same C++
1164 program, the "break -q B::func" command sets a breakpoint on
1165 "B::func", only. A parameter has been added to the Python
1166 gdb.Breakpoint constructor to achieve the same result when creating
1167 a breakpoint from Python.
1169 * Breakpoints on functions marked with C++ ABI tags
1171 GDB can now set breakpoints on functions marked with C++ ABI tags
1172 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1173 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1175 Functions with a C++11 abi tag are demangled/displayed like this:
1177 function[abi:cxx11](int)
1180 You can now set a breakpoint on such functions simply as if they had
1183 (gdb) b function(int)
1185 Or if you need to disambiguate between tags, like:
1187 (gdb) b function[abi:other_tag](int)
1189 Tab completion was adjusted accordingly as well.
1193 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1194 gdb.new_thread are emitted. See the manual for further
1195 description of these.
1197 ** A new function, "gdb.rbreak" has been added to the Python API.
1198 This function allows the setting of a large number of breakpoints
1199 via a regex pattern in Python. See the manual for further details.
1201 ** Python breakpoints can now accept explicit locations. See the
1202 manual for a further description of this feature.
1205 * New features in the GDB remote stub, GDBserver
1207 ** GDBserver is now able to start inferior processes with a
1208 specified initial working directory.
1210 The user can set the desired working directory to be used from
1211 GDB using the new "set cwd" command.
1213 ** New "--selftest" command line option runs some GDBserver self
1214 tests. These self tests are disabled in releases.
1216 ** On Unix systems, GDBserver now does globbing expansion and variable
1217 substitution in inferior command line arguments.
1219 This is done by starting inferiors using a shell, like GDB does.
1220 See "set startup-with-shell" in the user manual for how to disable
1221 this from GDB when using "target extended-remote". When using
1222 "target remote", you can disable the startup with shell by using the
1223 new "--no-startup-with-shell" GDBserver command line option.
1225 ** On Unix systems, GDBserver now supports receiving environment
1226 variables that are to be set or unset from GDB. These variables
1227 will affect the environment to be passed to the inferior.
1229 * When catching an Ada exception raised with a message, GDB now prints
1230 the message in the catchpoint hit notification. In GDB/MI mode, that
1231 information is provided as an extra field named "exception-message"
1232 in the *stopped notification.
1234 * Trait objects can now be inspected When debugging Rust code. This
1235 requires compiler support which will appear in Rust 1.24.
1237 * New remote packets
1239 QEnvironmentHexEncoded
1240 Inform GDBserver of an environment variable that is to be passed to
1241 the inferior when starting it.
1244 Inform GDBserver of an environment variable that is to be unset
1245 before starting the remote inferior.
1248 Inform GDBserver that the environment should be reset (i.e.,
1249 user-set environment variables should be unset).
1252 Indicates whether the inferior must be started with a shell or not.
1255 Tell GDBserver that the inferior to be started should use a specific
1258 * The "maintenance print c-tdesc" command now takes an optional
1259 argument which is the file name of XML target description.
1261 * The "maintenance selftest" command now takes an optional argument to
1262 filter the tests to be run.
1264 * The "enable", and "disable" commands now accept a range of
1265 breakpoint locations, e.g. "enable 1.3-5".
1270 Set and show the current working directory for the inferior.
1272 set|show compile-gcc
1273 Set and show compilation command used for compiling and injecting code
1274 with the 'compile' commands.
1276 set debug separate-debug-file
1277 show debug separate-debug-file
1278 Control the display of debug output about separate debug file search.
1280 set dump-excluded-mappings
1281 show dump-excluded-mappings
1282 Control whether mappings marked with the VM_DONTDUMP flag should be
1283 dumped when generating a core file.
1285 maint info selftests
1286 List the registered selftests.
1289 Start the debugged program stopping at the first instruction.
1292 Control display of debugging messages related to OpenRISC targets.
1294 set|show print type nested-type-limit
1295 Set and show the limit of nesting level for nested types that the
1296 type printer will show.
1298 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1301 * Safer/improved support for debugging with no debug info
1303 GDB no longer assumes functions with no debug information return
1306 This means that GDB now refuses to call such functions unless you
1307 tell it the function's type, by either casting the call to the
1308 declared return type, or by casting the function to a function
1309 pointer of the right type, and calling that:
1311 (gdb) p getenv ("PATH")
1312 'getenv' has unknown return type; cast the call to its declared return type
1313 (gdb) p (char *) getenv ("PATH")
1314 $1 = 0x7fffffffe "/usr/local/bin:/"...
1315 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1316 $2 = 0x7fffffffe "/usr/local/bin:/"...
1318 Similarly, GDB no longer assumes that global variables with no debug
1319 info have type 'int', and refuses to print the variable's value
1320 unless you tell it the variable's type:
1323 'var' has unknown type; cast it to its declared type
1327 * New native configurations
1329 FreeBSD/aarch64 aarch64*-*-freebsd*
1330 FreeBSD/arm arm*-*-freebsd*
1334 FreeBSD/aarch64 aarch64*-*-freebsd*
1335 FreeBSD/arm arm*-*-freebsd*
1336 OpenRISC ELF or1k*-*-elf
1338 * Removed targets and native configurations
1340 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1342 *** Changes in GDB 8.0
1344 * GDB now supports access to the PKU register on GNU/Linux. The register is
1345 added by the Memory Protection Keys for Userspace feature which will be
1346 available in future Intel CPUs.
1348 * GDB now supports C++11 rvalue references.
1352 ** New functions to start, stop and access a running btrace recording.
1353 ** Rvalue references are now supported in gdb.Type.
1355 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1358 * Building GDB and GDBserver now requires a C++11 compiler.
1360 For example, GCC 4.8 or later.
1362 It is no longer possible to build GDB or GDBserver with a C
1363 compiler. The --disable-build-with-cxx configure option has been
1366 * Building GDB and GDBserver now requires GNU make >= 3.81.
1368 It is no longer supported to build GDB or GDBserver with another
1369 implementation of the make program or an earlier version of GNU make.
1371 * Native debugging on MS-Windows supports command-line redirection
1373 Command-line arguments used for starting programs on MS-Windows can
1374 now include redirection symbols supported by native Windows shells,
1375 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1376 as "run", "start", and "set args", as well as the corresponding MI
1379 * Support for thread names on MS-Windows.
1381 GDB now catches and handles the special exception that programs
1382 running on MS-Windows use to assign names to threads in the
1385 * Support for Java programs compiled with gcj has been removed.
1387 * User commands now accept an unlimited number of arguments.
1388 Previously, only up to 10 was accepted.
1390 * The "eval" command now expands user-defined command arguments.
1392 This makes it easier to process a variable number of arguments:
1397 eval "print $arg%d", $i
1402 * Target descriptions can now describe registers for sparc32 and sparc64.
1404 * GDB now supports DWARF version 5 (debug information format).
1405 Its .debug_names index is not yet supported.
1407 * New native configurations
1409 FreeBSD/mips mips*-*-freebsd
1413 Synopsys ARC arc*-*-elf32
1414 FreeBSD/mips mips*-*-freebsd
1416 * Removed targets and native configurations
1418 Alpha running FreeBSD alpha*-*-freebsd*
1419 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1424 Erases all the flash memory regions reported by the target.
1426 maint print arc arc-instruction address
1427 Print internal disassembler information about instruction at a given address.
1431 set disassembler-options
1432 show disassembler-options
1433 Controls the passing of target specific information to the disassembler.
1434 If it is necessary to specify more than one disassembler option then
1435 multiple options can be placed together into a comma separated list.
1436 The default value is the empty string. Currently, the only supported
1437 targets are ARM, PowerPC and S/390.
1442 Erases all the flash memory regions reported by the target. This is
1443 equivalent to the CLI command flash-erase.
1445 -file-list-shared-libraries
1446 List the shared libraries in the program. This is
1447 equivalent to the CLI command "info shared".
1450 Catchpoints stopping the program when Ada exceptions are
1451 handled. This is equivalent to the CLI command "catch handlers".
1453 *** Changes in GDB 7.12
1455 * GDB and GDBserver now build with a C++ compiler by default.
1457 The --enable-build-with-cxx configure option is now enabled by
1458 default. One must now explicitly configure with
1459 --disable-build-with-cxx in order to build with a C compiler. This
1460 option will be removed in a future release.
1462 * GDBserver now supports recording btrace without maintaining an active
1465 * GDB now supports a negative repeat count in the 'x' command to examine
1466 memory backward from the given address. For example:
1469 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1470 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1471 (gdb) x/-5i 0x0000000000400580
1472 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1473 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1474 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1475 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1476 0x40057b <main(int, char**)+25>:
1477 callq 0x400536 <Func1(int, char const*)>
1479 * Fortran: Support structures with fields of dynamic types and
1480 arrays of dynamic types.
1482 * The symbol dumping maintenance commands have new syntax.
1483 maint print symbols [-pc address] [--] [filename]
1484 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1485 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1486 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1487 maint print msymbols [-objfile objfile] [--] [filename]
1489 * GDB now supports multibit bitfields and enums in target register
1492 * New Python-based convenience function $_as_string(val), which returns
1493 the textual representation of a value. This function is especially
1494 useful to obtain the text label of an enum value.
1496 * Intel MPX bound violation handling.
1498 Segmentation faults caused by a Intel MPX boundary violation
1499 now display the kind of violation (upper or lower), the memory
1500 address accessed and the memory bounds, along with the usual
1501 signal received and code location.
1505 Program received signal SIGSEGV, Segmentation fault
1506 Upper bound violation while accessing address 0x7fffffffc3b3
1507 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1508 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1510 * Rust language support.
1511 GDB now supports debugging programs written in the Rust programming
1512 language. See https://www.rust-lang.org/ for more information about
1515 * Support for running interpreters on specified input/output devices
1517 GDB now supports a new mechanism that allows frontends to provide
1518 fully featured GDB console views, as a better alternative to
1519 building such views on top of the "-interpreter-exec console"
1520 command. See the new "new-ui" command below. With that command,
1521 frontends can now start GDB in the traditional command-line mode
1522 running in an embedded terminal emulator widget, and create a
1523 separate MI interpreter running on a specified i/o device. In this
1524 way, GDB handles line editing, history, tab completion, etc. in the
1525 console all by itself, and the GUI uses the separate MI interpreter
1526 for its own control and synchronization, invisible to the command
1529 * The "catch syscall" command catches groups of related syscalls.
1531 The "catch syscall" command now supports catching a group of related
1532 syscalls using the 'group:' or 'g:' prefix.
1537 skip -gfile file-glob-pattern
1538 skip -function function
1539 skip -rfunction regular-expression
1540 A generalized form of the skip command, with new support for
1541 glob-style file names and regular expressions for function names.
1542 Additionally, a file spec and a function spec may now be combined.
1544 maint info line-table REGEXP
1545 Display the contents of GDB's internal line table data structure.
1548 Run any GDB unit tests that were compiled in.
1551 Start a new user interface instance running INTERP as interpreter,
1552 using the TTY file for input/output.
1556 ** gdb.Breakpoint objects have a new attribute "pending", which
1557 indicates whether the breakpoint is pending.
1558 ** Three new breakpoint-related events have been added:
1559 gdb.breakpoint_created, gdb.breakpoint_modified, and
1560 gdb.breakpoint_deleted.
1562 signal-event EVENTID
1563 Signal ("set") the given MS-Windows event object. This is used in
1564 conjunction with the Windows JIT debugging (AeDebug) support, where
1565 the OS suspends a crashing process until a debugger can attach to
1566 it. Resuming the crashing process, in order to debug it, is done by
1567 signalling an event.
1569 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1570 was added in GDBserver, including JIT compiling fast tracepoint's
1571 conditional expression bytecode into native code.
1573 * Support for various remote target protocols and ROM monitors has
1576 target m32rsdi Remote M32R debugging over SDI
1577 target mips MIPS remote debugging protocol
1578 target pmon PMON ROM monitor
1579 target ddb NEC's DDB variant of PMON for Vr4300
1580 target rockhopper NEC RockHopper variant of PMON
1581 target lsi LSI variant of PMO
1583 * Support for tracepoints and fast tracepoints on powerpc-linux,
1584 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1585 including JIT compiling fast tracepoint's conditional expression
1586 bytecode into native code.
1588 * MI async record =record-started now includes the method and format used for
1589 recording. For example:
1591 =record-started,thread-group="i1",method="btrace",format="bts"
1593 * MI async record =thread-selected now includes the frame field. For example:
1595 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1599 Andes NDS32 nds32*-*-elf
1601 *** Changes in GDB 7.11
1603 * GDB now supports debugging kernel-based threads on FreeBSD.
1605 * Per-inferior thread numbers
1607 Thread numbers are now per inferior instead of global. If you're
1608 debugging multiple inferiors, GDB displays thread IDs using a
1609 qualified INF_NUM.THR_NUM form. For example:
1613 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1614 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1615 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1616 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1618 As consequence, thread numbers as visible in the $_thread
1619 convenience variable and in Python's InferiorThread.num attribute
1620 are no longer unique between inferiors.
1622 GDB now maintains a second thread ID per thread, referred to as the
1623 global thread ID, which is the new equivalent of thread numbers in
1624 previous releases. See also $_gthread below.
1626 For backwards compatibility, MI's thread IDs always refer to global
1629 * Commands that accept thread IDs now accept the qualified
1630 INF_NUM.THR_NUM form as well. For example:
1633 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1636 * In commands that accept a list of thread IDs, you can now refer to
1637 all threads of an inferior using a star wildcard. GDB accepts
1638 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1639 refer to all threads of the current inferior. For example, "info
1642 * You can use "info threads -gid" to display the global thread ID of
1645 * The new convenience variable $_gthread holds the global number of
1648 * The new convenience variable $_inferior holds the number of the
1651 * GDB now displays the ID and name of the thread that hit a breakpoint
1652 or received a signal, if your program is multi-threaded. For
1655 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1656 Thread 1 "main" received signal SIGINT, Interrupt.
1658 * Record btrace now supports non-stop mode.
1660 * Support for tracepoints on aarch64-linux was added in GDBserver.
1662 * The 'record instruction-history' command now indicates speculative execution
1663 when using the Intel Processor Trace recording format.
1665 * GDB now allows users to specify explicit locations, bypassing
1666 the linespec parser. This feature is also available to GDB/MI
1669 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1670 GDB now is able to debug both AArch64 applications and ARM applications
1673 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1674 including JIT compiling fast tracepoint's conditional expression bytecode
1677 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1679 * "info threads", "info inferiors", "info display", "info checkpoints"
1680 and "maint info program-spaces" now list the corresponding items in
1681 ascending ID order, for consistency with all other "info" commands.
1683 * In Ada, the overloads selection menu has been enhanced to display the
1684 parameter types and the return types for the matching overloaded subprograms.
1688 maint set target-non-stop (on|off|auto)
1689 maint show target-non-stop
1690 Control whether GDB targets always operate in non-stop mode even if
1691 "set non-stop" is "off". The default is "auto", meaning non-stop
1692 mode is enabled if supported by the target.
1694 maint set bfd-sharing
1695 maint show bfd-sharing
1696 Control the reuse of bfd objects.
1699 show debug bfd-cache
1700 Control display of debugging info regarding bfd caching.
1704 Control display of debugging info regarding FreeBSD threads.
1706 set remote multiprocess-extensions-packet
1707 show remote multiprocess-extensions-packet
1708 Set/show the use of the remote protocol multiprocess extensions.
1710 set remote thread-events
1711 show remote thread-events
1712 Set/show the use of thread create/exit events.
1714 set ada print-signatures on|off
1715 show ada print-signatures"
1716 Control whether parameter types and return types are displayed in overloads
1717 selection menus. It is activated (@code{on}) by default.
1721 Controls the maximum size of memory, in bytes, that GDB will
1722 allocate for value contents. Prevents incorrect programs from
1723 causing GDB to allocate overly large buffers. Default is 64k.
1725 * The "disassemble" command accepts a new modifier: /s.
1726 It prints mixed source+disassembly like /m with two differences:
1727 - disassembled instructions are now printed in program order, and
1728 - and source for all relevant files is now printed.
1729 The "/m" option is now considered deprecated: its "source-centric"
1730 output hasn't proved useful in practice.
1732 * The "record instruction-history" command accepts a new modifier: /s.
1733 It behaves exactly like /m and prints mixed source+disassembly.
1735 * The "set scheduler-locking" command supports a new mode "replay".
1736 It behaves like "off" in record mode and like "on" in replay mode.
1738 * Support for various ROM monitors has been removed:
1740 target dbug dBUG ROM monitor for Motorola ColdFire
1741 target picobug Motorola picobug monitor
1742 target dink32 DINK32 ROM monitor for PowerPC
1743 target m32r Renesas M32R/D ROM monitor
1744 target mon2000 mon2000 ROM monitor
1745 target ppcbug PPCBUG ROM monitor for PowerPC
1747 * Support for reading/writing memory and extracting values on architectures
1748 whose memory is addressable in units of any integral multiple of 8 bits.
1751 Allows to break when an Ada exception is handled.
1753 * New remote packets
1756 Indicates that an exec system call was executed.
1758 exec-events feature in qSupported
1759 The qSupported packet allows GDB to request support for exec
1760 events using the new 'gdbfeature' exec-event, and the qSupported
1761 response can contain the corresponding 'stubfeature'. Set and
1762 show commands can be used to display whether these features are enabled.
1765 Equivalent to interrupting with the ^C character, but works in
1768 thread created stop reason (T05 create:...)
1769 Indicates that the thread was just created and is stopped at entry.
1771 thread exit stop reply (w exitcode;tid)
1772 Indicates that the thread has terminated.
1775 Enables/disables thread create and exit event reporting. For
1776 example, this is used in non-stop mode when GDB stops a set of
1777 threads and synchronously waits for the their corresponding stop
1778 replies. Without exit events, if one of the threads exits, GDB
1779 would hang forever not knowing that it should no longer expect a
1780 stop for that same thread.
1783 Indicates that there are no resumed threads left in the target (all
1784 threads are stopped). The remote stub reports support for this stop
1785 reply to GDB's qSupported query.
1788 Enables/disables catching syscalls from the inferior process.
1789 The remote stub reports support for this packet to GDB's qSupported query.
1791 syscall_entry stop reason
1792 Indicates that a syscall was just called.
1794 syscall_return stop reason
1795 Indicates that a syscall just returned.
1797 * Extended-remote exec events
1799 ** GDB now has support for exec events on extended-remote Linux targets.
1800 For such targets with Linux kernels 2.5.46 and later, this enables
1801 follow-exec-mode and exec catchpoints.
1803 set remote exec-event-feature-packet
1804 show remote exec-event-feature-packet
1805 Set/show the use of the remote exec event feature.
1807 * Thread names in remote protocol
1809 The reply to qXfer:threads:read may now include a name attribute for each
1812 * Target remote mode fork and exec events
1814 ** GDB now has support for fork and exec events on target remote mode
1815 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1816 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1817 fork and exec catchpoints.
1819 * Remote syscall events
1821 ** GDB now has support for catch syscall on remote Linux targets,
1822 currently enabled on x86/x86_64 architectures.
1824 set remote catch-syscall-packet
1825 show remote catch-syscall-packet
1826 Set/show the use of the remote catch syscall feature.
1830 ** The -var-set-format command now accepts the zero-hexadecimal
1831 format. It outputs data in hexadecimal format with zero-padding on the
1836 ** gdb.InferiorThread objects have a new attribute "global_num",
1837 which refers to the thread's global thread ID. The existing
1838 "num" attribute now refers to the thread's per-inferior number.
1839 See "Per-inferior thread numbers" above.
1840 ** gdb.InferiorThread objects have a new attribute "inferior", which
1841 is the Inferior object the thread belongs to.
1843 *** Changes in GDB 7.10
1845 * Support for process record-replay and reverse debugging on aarch64*-linux*
1846 targets has been added. GDB now supports recording of A64 instruction set
1847 including advance SIMD instructions.
1849 * Support for Sun's version of the "stabs" debug file format has been removed.
1851 * GDB now honors the content of the file /proc/PID/coredump_filter
1852 (PID is the process ID) on GNU/Linux systems. This file can be used
1853 to specify the types of memory mappings that will be included in a
1854 corefile. For more information, please refer to the manual page of
1855 "core(5)". GDB also has a new command: "set use-coredump-filter
1856 on|off". It allows to set whether GDB will read the content of the
1857 /proc/PID/coredump_filter file when generating a corefile.
1859 * The "info os" command on GNU/Linux can now display information on
1861 "info os cpus" Listing of all cpus/cores on the system
1863 * GDB has two new commands: "set serial parity odd|even|none" and
1864 "show serial parity". These allows to set or show parity for the
1867 * The "info source" command now displays the producer string if it was
1868 present in the debug info. This typically includes the compiler version
1869 and may include things like its command line arguments.
1871 * The "info dll", an alias of the "info sharedlibrary" command,
1872 is now available on all platforms.
1874 * Directory names supplied to the "set sysroot" commands may be
1875 prefixed with "target:" to tell GDB to access shared libraries from
1876 the target system, be it local or remote. This replaces the prefix
1877 "remote:". The default sysroot has been changed from "" to
1878 "target:". "remote:" is automatically converted to "target:" for
1879 backward compatibility.
1881 * The system root specified by "set sysroot" will be prepended to the
1882 filename of the main executable (if reported to GDB as absolute by
1883 the operating system) when starting processes remotely, and when
1884 attaching to already-running local or remote processes.
1886 * GDB now supports automatic location and retrieval of executable
1887 files from remote targets. Remote debugging can now be initiated
1888 using only a "target remote" or "target extended-remote" command
1889 (no "set sysroot" or "file" commands are required). See "New remote
1892 * The "dump" command now supports verilog hex format.
1894 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1896 * On GNU/Linux, GDB and gdbserver are now able to access executable
1897 and shared library files without a "set sysroot" command when
1898 attaching to processes running in different mount namespaces from
1899 the debugger. This makes it possible to attach to processes in
1900 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1901 See "New remote packets" below.
1903 * The "tui reg" command now provides completion for all of the
1904 available register groups, including target specific groups.
1906 * The HISTSIZE environment variable is no longer read when determining
1907 the size of GDB's command history. GDB now instead reads the dedicated
1908 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1909 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1914 ** Memory ports can now be unbuffered.
1918 ** gdb.Objfile objects have a new attribute "username",
1919 which is the name of the objfile as specified by the user,
1920 without, for example, resolving symlinks.
1921 ** You can now write frame unwinders in Python.
1922 ** gdb.Type objects have a new method "optimized_out",
1923 returning optimized out gdb.Value instance of this type.
1924 ** gdb.Value objects have new methods "reference_value" and
1925 "const_value" which return a reference to the value and a
1926 "const" version of the value respectively.
1930 maint print symbol-cache
1931 Print the contents of the symbol cache.
1933 maint print symbol-cache-statistics
1934 Print statistics of symbol cache usage.
1936 maint flush-symbol-cache
1937 Flush the contents of the symbol cache.
1941 Start branch trace recording using Branch Trace Store (BTS) format.
1944 Evaluate expression by using the compiler and print result.
1948 Explicit commands for enabling and disabling tui mode.
1951 set mpx bound on i386 and amd64
1952 Support for bound table investigation on Intel MPX enabled applications.
1956 Start branch trace recording using Intel Processor Trace format.
1959 Print information about branch tracing internals.
1961 maint btrace packet-history
1962 Print the raw branch tracing data.
1964 maint btrace clear-packet-history
1965 Discard the stored raw branch tracing data.
1968 Discard all branch tracing data. It will be fetched and processed
1969 anew by the next "record" command.
1974 Renamed from "set debug dwarf2-die".
1975 show debug dwarf-die
1976 Renamed from "show debug dwarf2-die".
1978 set debug dwarf-read
1979 Renamed from "set debug dwarf2-read".
1980 show debug dwarf-read
1981 Renamed from "show debug dwarf2-read".
1983 maint set dwarf always-disassemble
1984 Renamed from "maint set dwarf2 always-disassemble".
1985 maint show dwarf always-disassemble
1986 Renamed from "maint show dwarf2 always-disassemble".
1988 maint set dwarf max-cache-age
1989 Renamed from "maint set dwarf2 max-cache-age".
1990 maint show dwarf max-cache-age
1991 Renamed from "maint show dwarf2 max-cache-age".
1993 set debug dwarf-line
1994 show debug dwarf-line
1995 Control display of debugging info regarding DWARF line processing.
1998 show max-completions
1999 Set the maximum number of candidates to be considered during
2000 completion. The default value is 200. This limit allows GDB
2001 to avoid generating large completion lists, the computation of
2002 which can cause the debugger to become temporarily unresponsive.
2004 set history remove-duplicates
2005 show history remove-duplicates
2006 Control the removal of duplicate history entries.
2008 maint set symbol-cache-size
2009 maint show symbol-cache-size
2010 Control the size of the symbol cache.
2012 set|show record btrace bts buffer-size
2013 Set and show the size of the ring buffer used for branch tracing in
2015 The obtained size may differ from the requested size. Use "info
2016 record" to see the obtained buffer size.
2018 set debug linux-namespaces
2019 show debug linux-namespaces
2020 Control display of debugging info regarding Linux namespaces.
2022 set|show record btrace pt buffer-size
2023 Set and show the size of the ring buffer used for branch tracing in
2024 Intel Processor Trace format.
2025 The obtained size may differ from the requested size. Use "info
2026 record" to see the obtained buffer size.
2028 maint set|show btrace pt skip-pad
2029 Set and show whether PAD packets are skipped when computing the
2032 * The command 'thread apply all' can now support new option '-ascending'
2033 to call its specified command for all threads in ascending order.
2035 * Python/Guile scripting
2037 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2038 special section named `.debug_gdb_scripts'.
2040 * New remote packets
2042 qXfer:btrace-conf:read
2043 Return the branch trace configuration for the current thread.
2045 Qbtrace-conf:bts:size
2046 Set the requested ring buffer size for branch tracing in BTS format.
2049 Enable Intel Processor Trace-based branch tracing for the current
2050 process. The remote stub reports support for this packet to GDB's
2053 Qbtrace-conf:pt:size
2054 Set the requested ring buffer size for branch tracing in Intel Processor
2058 Indicates a memory breakpoint instruction was executed, irrespective
2059 of whether it was GDB that planted the breakpoint or the breakpoint
2060 is hardcoded in the program. This is required for correct non-stop
2064 Indicates the target stopped for a hardware breakpoint. This is
2065 required for correct non-stop mode operation.
2068 Return information about files on the remote system.
2070 qXfer:exec-file:read
2071 Return the full absolute name of the file that was executed to
2072 create a process running on the remote system.
2075 Select the filesystem on which vFile: operations with filename
2076 arguments will operate. This is required for GDB to be able to
2077 access files on remote targets where the remote stub does not
2078 share a common filesystem with the inferior(s).
2081 Indicates that a fork system call was executed.
2084 Indicates that a vfork system call was executed.
2086 vforkdone stop reason
2087 Indicates that a vfork child of the specified process has executed
2088 an exec or exit, allowing the vfork parent to resume execution.
2090 fork-events and vfork-events features in qSupported
2091 The qSupported packet allows GDB to request support for fork and
2092 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2093 and the qSupported response can contain the corresponding
2094 'stubfeatures'. Set and show commands can be used to display
2095 whether these features are enabled.
2097 * Extended-remote fork events
2099 ** GDB now has support for fork events on extended-remote Linux
2100 targets. For targets with Linux kernels 2.5.60 and later, this
2101 enables follow-fork-mode and detach-on-fork for both fork and
2102 vfork, as well as fork and vfork catchpoints.
2104 * The info record command now shows the recording format and the
2105 branch tracing configuration for the current thread when using
2106 the btrace record target.
2107 For the BTS format, it shows the ring buffer size.
2109 * GDB now has support for DTrace USDT (Userland Static Defined
2110 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2112 * GDB now supports access to vector registers on S/390 GNU/Linux
2115 * Removed command line options
2117 -xdb HP-UX XDB compatibility mode.
2119 * Removed targets and native configurations
2121 HP/PA running HP-UX hppa*-*-hpux*
2122 Itanium running HP-UX ia64-*-hpux*
2124 * New configure options
2127 This configure option allows the user to build GDB with support for
2128 Intel Processor Trace (default: auto). This requires libipt.
2130 --with-libipt-prefix=PATH
2131 Specify the path to the version of libipt that GDB should use.
2132 $PATH/include should contain the intel-pt.h header and
2133 $PATH/lib should contain the libipt.so library.
2135 *** Changes in GDB 7.9.1
2139 ** Xmethods can now specify a result type.
2141 *** Changes in GDB 7.9
2143 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2147 ** You can now access frame registers from Python scripts.
2148 ** New attribute 'producer' for gdb.Symtab objects.
2149 ** gdb.Objfile objects have a new attribute "progspace",
2150 which is the gdb.Progspace object of the containing program space.
2151 ** gdb.Objfile objects have a new attribute "owner".
2152 ** gdb.Objfile objects have a new attribute "build_id",
2153 which is the build ID generated when the file was built.
2154 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2155 ** A new event "gdb.clear_objfiles" has been added, triggered when
2156 selecting a new file to debug.
2157 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2158 ** New function gdb.lookup_objfile.
2160 New events which are triggered when GDB modifies the state of the
2163 ** gdb.events.inferior_call_pre: Function call is about to be made.
2164 ** gdb.events.inferior_call_post: Function call has just been made.
2165 ** gdb.events.memory_changed: A memory location has been altered.
2166 ** gdb.events.register_changed: A register has been altered.
2168 * New Python-based convenience functions:
2170 ** $_caller_is(name [, number_of_frames])
2171 ** $_caller_matches(regexp [, number_of_frames])
2172 ** $_any_caller_is(name [, number_of_frames])
2173 ** $_any_caller_matches(regexp [, number_of_frames])
2175 * GDB now supports the compilation and injection of source code into
2176 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2177 to compile the source code to object code, and if successful, inject
2178 and execute that code within the current context of the inferior.
2179 Currently the C language is supported. The commands used to
2180 interface with this new feature are:
2182 compile code [-raw|-r] [--] [source code]
2183 compile file [-raw|-r] filename
2187 demangle [-l language] [--] name
2188 Demangle "name" in the specified language, or the current language
2189 if elided. This command is renamed from the "maint demangle" command.
2190 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2191 as "maint demangler-warning".
2193 queue-signal signal-name-or-number
2194 Queue a signal to be delivered to the thread when it is resumed.
2196 add-auto-load-scripts-directory directory
2197 Add entries to the list of directories from which to load auto-loaded
2200 maint print user-registers
2201 List all currently available "user" registers.
2203 compile code [-r|-raw] [--] [source code]
2204 Compile, inject, and execute in the inferior the executable object
2205 code produced by compiling the provided source code.
2207 compile file [-r|-raw] filename
2208 Compile and inject into the inferior the executable object code
2209 produced by compiling the source code stored in the filename
2212 * On resume, GDB now always passes the signal the program had stopped
2213 for to the thread the signal was sent to, even if the user changed
2214 threads before resuming. Previously GDB would often (but not
2215 always) deliver the signal to the thread that happens to be current
2218 * Conversely, the "signal" command now consistently delivers the
2219 requested signal to the current thread. GDB now asks for
2220 confirmation if the program had stopped for a signal and the user
2221 switched threads meanwhile.
2223 * "breakpoint always-inserted" modes "off" and "auto" merged.
2225 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2226 won't remove breakpoints from the target until all threads stop,
2227 even in non-stop mode. The "auto" mode has been removed, and "off"
2228 is now the default mode.
2232 set debug symbol-lookup
2233 show debug symbol-lookup
2234 Control display of debugging info regarding symbol lookup.
2238 ** The -list-thread-groups command outputs an exit-code field for
2239 inferiors that have exited.
2243 MIPS SDE mips*-sde*-elf*
2247 Support for these obsolete configurations has been removed.
2249 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2250 SGI Irix-5.x mips-*-irix5*
2251 SGI Irix-6.x mips-*-irix6*
2252 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2253 VAX running Ultrix vax-*-ultrix*
2255 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2256 and "assf"), have been removed. Use the "sharedlibrary" command, or
2257 its alias "share", instead.
2259 *** Changes in GDB 7.8
2261 * New command line options
2264 This is an alias for the --data-directory option.
2266 * GDB supports printing and modifying of variable length automatic arrays
2267 as specified in ISO C99.
2269 * The ARM simulator now supports instruction level tracing
2270 with or without disassembly.
2274 GDB now has support for scripting using Guile. Whether this is
2275 available is determined at configure time.
2276 Guile version 2.0 or greater is required.
2277 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2279 * New commands (for set/show, see "New options" below)
2283 Invoke CODE by passing it to the Guile interpreter.
2287 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2289 info auto-load guile-scripts [regexp]
2290 Print the list of automatically loaded Guile scripts.
2292 * The source command is now capable of sourcing Guile scripts.
2293 This feature is dependent on the debugger being built with Guile support.
2297 set print symbol-loading (off|brief|full)
2298 show print symbol-loading
2299 Control whether to print informational messages when loading symbol
2300 information for a file. The default is "full", but when debugging
2301 programs with large numbers of shared libraries the amount of output
2302 becomes less useful.
2304 set guile print-stack (none|message|full)
2305 show guile print-stack
2306 Show a stack trace when an error is encountered in a Guile script.
2308 set auto-load guile-scripts (on|off)
2309 show auto-load guile-scripts
2310 Control auto-loading of Guile script files.
2312 maint ada set ignore-descriptive-types (on|off)
2313 maint ada show ignore-descriptive-types
2314 Control whether the debugger should ignore descriptive types in Ada
2315 programs. The default is not to ignore the descriptive types. See
2316 the user manual for more details on descriptive types and the intended
2317 usage of this option.
2319 set auto-connect-native-target
2321 Control whether GDB is allowed to automatically connect to the
2322 native target for the run, attach, etc. commands when not connected
2323 to any target yet. See also "target native" below.
2325 set record btrace replay-memory-access (read-only|read-write)
2326 show record btrace replay-memory-access
2327 Control what memory accesses are allowed during replay.
2329 maint set target-async (on|off)
2330 maint show target-async
2331 This controls whether GDB targets operate in synchronous or
2332 asynchronous mode. Normally the default is asynchronous, if it is
2333 available; but this can be changed to more easily debug problems
2334 occurring only in synchronous mode.
2336 set mi-async (on|off)
2338 Control whether MI asynchronous mode is preferred. This supersedes
2339 "set target-async" of previous GDB versions.
2341 * "set target-async" is deprecated as a CLI option and is now an alias
2342 for "set mi-async" (only puts MI into async mode).
2344 * Background execution commands (e.g., "c&", "s&", etc.) are now
2345 possible ``out of the box'' if the target supports them. Previously
2346 the user would need to explicitly enable the possibility with the
2347 "set target-async on" command.
2349 * New features in the GDB remote stub, GDBserver
2351 ** New option --debug-format=option1[,option2,...] allows one to add
2352 additional text to each output. At present only timestamps
2353 are supported: --debug-format=timestamps.
2354 Timestamps can also be turned on with the
2355 "monitor set debug-format timestamps" command from GDB.
2357 * The 'record instruction-history' command now starts counting instructions
2358 at one. This also affects the instruction ranges reported by the
2359 'record function-call-history' command when given the /i modifier.
2361 * The command 'record function-call-history' supports a new modifier '/c' to
2362 indent the function names based on their call stack depth.
2363 The fields for the '/i' and '/l' modifier have been reordered.
2364 The source line range is now prefixed with 'at'.
2365 The instruction range is now prefixed with 'inst'.
2366 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2367 "record instruction-history" and "list" commands.
2369 * The ranges given as arguments to the 'record function-call-history' and
2370 'record instruction-history' commands are now inclusive.
2372 * The btrace record target now supports the 'record goto' command.
2373 For locations inside the execution trace, the back trace is computed
2374 based on the information stored in the execution trace.
2376 * The btrace record target supports limited reverse execution and replay.
2377 The target does not record data and therefore does not allow reading
2378 memory or registers.
2380 * The "catch syscall" command now works on s390*-linux* targets.
2382 * The "compare-sections" command is no longer specific to target
2383 remote. It now works with all targets.
2385 * All native targets are now consistently called "native".
2386 Consequently, the "target child", "target GNU", "target djgpp",
2387 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2388 commands have been replaced with "target native". The QNX/NTO port
2389 leaves the "procfs" target in place and adds a "native" target for
2390 consistency with other ports. The impact on users should be minimal
2391 as these commands previously either throwed an error, or were
2392 no-ops. The target's name is visible in the output of the following
2393 commands: "help target", "info target", "info files", "maint print
2396 * The "target native" command now connects to the native target. This
2397 can be used to launch native programs even when "set
2398 auto-connect-native-target" is set to off.
2400 * GDB now supports access to Intel MPX registers on GNU/Linux.
2402 * Support for Intel AVX-512 registers on GNU/Linux.
2403 Support displaying and modifying Intel AVX-512 registers
2404 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2406 * New remote packets
2408 qXfer:btrace:read's annex
2409 The qXfer:btrace:read packet supports a new annex 'delta' to read
2410 branch trace incrementally.
2414 ** Valid Python operations on gdb.Value objects representing
2415 structs/classes invoke the corresponding overloaded operators if
2417 ** New `Xmethods' feature in the Python API. Xmethods are
2418 additional methods or replacements for existing methods of a C++
2419 class. This feature is useful for those cases where a method
2420 defined in C++ source code could be inlined or optimized out by
2421 the compiler, making it unavailable to GDB.
2424 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2426 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2427 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2428 its alias "share", instead.
2430 * The commands "set remotebaud" and "show remotebaud" are no longer
2431 supported. Use "set serial baud" and "show serial baud" (respectively)
2436 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2437 target-async". The latter is left as a deprecated alias of the
2438 former for backward compatibility. If the target supports it,
2439 CLI background execution commands are now always possible by
2440 default, independently of whether the frontend stated a
2441 preference for asynchronous execution with "-gdb-set mi-async".
2442 Previously "-gdb-set target-async off" affected both MI execution
2443 commands and CLI execution commands.
2445 *** Changes in GDB 7.7
2447 * Improved support for process record-replay and reverse debugging on
2448 arm*-linux* targets. Support for thumb32 and syscall instruction
2449 recording has been added.
2451 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2453 * GDB now supports Fission DWP file format version 2.
2454 http://gcc.gnu.org/wiki/DebugFission
2456 * New convenience function "$_isvoid", to check whether an expression
2457 is void. A void expression is an expression where the type of the
2458 result is "void". For example, some convenience variables may be
2459 "void" when evaluated (e.g., "$_exitcode" before the execution of
2460 the program being debugged; or an undefined convenience variable).
2461 Another example, when calling a function whose return type is
2464 * The "maintenance print objfiles" command now takes an optional regexp.
2466 * The "catch syscall" command now works on arm*-linux* targets.
2468 * GDB now consistently shows "<not saved>" when printing values of
2469 registers the debug info indicates have not been saved in the frame
2470 and there's nowhere to retrieve them from
2471 (callee-saved/call-clobbered registers):
2476 (gdb) info registers rax
2479 Before, the former would print "<optimized out>", and the latter
2480 "*value not available*".
2482 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2487 ** Frame filters and frame decorators have been added.
2488 ** Temporary breakpoints are now supported.
2489 ** Line tables representation has been added.
2490 ** New attribute 'parent_type' for gdb.Field objects.
2491 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2492 ** New attribute 'name' for gdb.Type objects.
2496 Nios II ELF nios2*-*-elf
2497 Nios II GNU/Linux nios2*-*-linux
2498 Texas Instruments MSP430 msp430*-*-elf
2500 * Removed native configurations
2502 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2503 been removed. ELF variants of these configurations are kept supported.
2505 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2506 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2507 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2508 i[34567]86-*-openbsd3.[0-3]
2509 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2510 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2511 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2515 Like "catch throw", but catches a re-thrown exception.
2516 maint check-psymtabs
2517 Renamed from old "maint check-symtabs".
2519 Perform consistency checks on symtabs.
2520 maint expand-symtabs
2521 Expand symtabs matching an optional regexp.
2524 Display the details of GDB configure-time options.
2526 maint set|show per-command
2527 maint set|show per-command space
2528 maint set|show per-command time
2529 maint set|show per-command symtab
2530 Enable display of per-command gdb resource usage.
2532 remove-symbol-file FILENAME
2533 remove-symbol-file -a ADDRESS
2534 Remove a symbol file added via add-symbol-file. The file to remove
2535 can be identified by its filename or by an address that lies within
2536 the boundaries of this symbol file in memory.
2539 info exceptions REGEXP
2540 Display the list of Ada exceptions defined in the program being
2541 debugged. If provided, only the exceptions whose names match REGEXP
2546 set debug symfile off|on
2548 Control display of debugging info regarding reading symbol files and
2549 symbol tables within those files
2551 set print raw frame-arguments
2552 show print raw frame-arguments
2553 Set/show whether to print frame arguments in raw mode,
2554 disregarding any defined pretty-printers.
2556 set remote trace-status-packet
2557 show remote trace-status-packet
2558 Set/show the use of remote protocol qTStatus packet.
2562 Control display of debugging messages related to Nios II targets.
2566 Control whether target-assisted range stepping is enabled.
2568 set startup-with-shell
2569 show startup-with-shell
2570 Specifies whether Unix child processes are started via a shell or
2575 Use the target memory cache for accesses to the code segment. This
2576 improves performance of remote debugging (particularly disassembly).
2578 * You can now use a literal value 'unlimited' for options that
2579 interpret 0 or -1 as meaning "unlimited". E.g., "set
2580 trace-buffer-size unlimited" is now an alias for "set
2581 trace-buffer-size -1" and "set height unlimited" is now an alias for
2584 * The "set debug symtab-create" debugging option of GDB has been changed to
2585 accept a verbosity level. 0 means "off", 1 provides basic debugging
2586 output, and values of 2 or greater provides more verbose output.
2588 * New command-line options
2590 Display the details of GDB configure-time options.
2592 * The command 'tsave' can now support new option '-ctf' to save trace
2593 buffer in Common Trace Format.
2595 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2598 * GDB now implements the C++ 'typeid' operator.
2600 * The new convenience variable $_exception holds the exception being
2601 thrown or caught at an exception-related catchpoint.
2603 * The exception-related catchpoints, like "catch throw", now accept a
2604 regular expression which can be used to filter exceptions by type.
2606 * The new convenience variable $_exitsignal is automatically set to
2607 the terminating signal number when the program being debugged dies
2608 due to an uncaught signal.
2612 ** All MI commands now accept an optional "--language" option.
2613 Support for this feature can be verified by using the "-list-features"
2614 command, which should contain "language-option".
2616 ** The new command -info-gdb-mi-command allows the user to determine
2617 whether a GDB/MI command is supported or not.
2619 ** The "^error" result record returned when trying to execute an undefined
2620 GDB/MI command now provides a variable named "code" whose content is the
2621 "undefined-command" error code. Support for this feature can be verified
2622 by using the "-list-features" command, which should contain
2623 "undefined-command-error-code".
2625 ** The -trace-save MI command can optionally save trace buffer in Common
2628 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2630 ** The command -data-list-register-values now accepts an optional
2631 "--skip-unavailable" option. When used, only the available registers
2634 ** The new command -trace-frame-collected dumps collected variables,
2635 computed expressions, tvars, memory and registers in a traceframe.
2637 ** The commands -stack-list-locals, -stack-list-arguments and
2638 -stack-list-variables now accept an option "--skip-unavailable".
2639 When used, only the available locals or arguments are displayed.
2641 ** The -exec-run command now accepts an optional "--start" option.
2642 When used, the command follows the same semantics as the "start"
2643 command, stopping the program's execution at the start of its
2644 main subprogram. Support for this feature can be verified using
2645 the "-list-features" command, which should contain
2646 "exec-run-start-option".
2648 ** The new commands -catch-assert and -catch-exceptions insert
2649 catchpoints stopping the program when Ada exceptions are raised.
2651 ** The new command -info-ada-exceptions provides the equivalent of
2652 the new "info exceptions" command.
2654 * New system-wide configuration scripts
2655 A GDB installation now provides scripts suitable for use as system-wide
2656 configuration scripts for the following systems:
2660 * GDB now supports target-assigned range stepping with remote targets.
2661 This improves the performance of stepping source lines by reducing
2662 the number of control packets from/to GDB. See "New remote packets"
2665 * GDB now understands the element 'tvar' in the XML traceframe info.
2666 It has the id of the collected trace state variables.
2668 * On S/390 targets that provide the transactional-execution feature,
2669 the program interruption transaction diagnostic block (TDB) is now
2670 represented as a number of additional "registers" in GDB.
2672 * New remote packets
2676 The vCont packet supports a new 'r' action, that tells the remote
2677 stub to step through an address range itself, without GDB
2678 involvemement at each single-step.
2680 qXfer:libraries-svr4:read's annex
2681 The previously unused annex of the qXfer:libraries-svr4:read packet
2682 is now used to support passing an argument list. The remote stub
2683 reports support for this argument list to GDB's qSupported query.
2684 The defined arguments are "start" and "prev", used to reduce work
2685 necessary for library list updating, resulting in significant
2688 * New features in the GDB remote stub, GDBserver
2690 ** GDBserver now supports target-assisted range stepping. Currently
2691 enabled on x86/x86_64 GNU/Linux targets.
2693 ** GDBserver now adds element 'tvar' in the XML in the reply to
2694 'qXfer:traceframe-info:read'. It has the id of the collected
2695 trace state variables.
2697 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2700 * New 'z' formatter for printing and examining memory, this displays the
2701 value as hexadecimal zero padded on the left to the size of the type.
2703 * GDB can now use Windows x64 unwinding data.
2705 * The "set remotebaud" command has been replaced by "set serial baud".
2706 Similarly, "show remotebaud" has been replaced by "show serial baud".
2707 The "set remotebaud" and "show remotebaud" commands are still available
2708 to provide backward compatibility with older versions of GDB.
2710 *** Changes in GDB 7.6
2712 * Target record has been renamed to record-full.
2713 Record/replay is now enabled with the "record full" command.
2714 This also affects settings that are associated with full record/replay
2715 that have been moved from "set/show record" to "set/show record full":
2717 set|show record full insn-number-max
2718 set|show record full stop-at-limit
2719 set|show record full memory-query
2721 * A new record target "record-btrace" has been added. The new target
2722 uses hardware support to record the control-flow of a process. It
2723 does not support replaying the execution, but it implements the
2724 below new commands for investigating the recorded execution log.
2725 This new recording method can be enabled using:
2729 The "record-btrace" target is only available on Intel Atom processors
2730 and requires a Linux kernel 2.6.32 or later.
2732 * Two new commands have been added for record/replay to give information
2733 about the recorded execution without having to replay the execution.
2734 The commands are only supported by "record btrace".
2736 record instruction-history prints the execution history at
2737 instruction granularity
2739 record function-call-history prints the execution history at
2740 function granularity
2742 * New native configurations
2744 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2745 FreeBSD/powerpc powerpc*-*-freebsd
2746 x86_64/Cygwin x86_64-*-cygwin*
2747 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2751 ARM AArch64 aarch64*-*-elf
2752 ARM AArch64 GNU/Linux aarch64*-*-linux
2753 Lynx 178 PowerPC powerpc-*-lynx*178
2754 x86_64/Cygwin x86_64-*-cygwin*
2755 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2757 * If the configured location of system.gdbinit file (as given by the
2758 --with-system-gdbinit option at configure time) is in the
2759 data-directory (as specified by --with-gdb-datadir at configure
2760 time) or in one of its subdirectories, then GDB will look for the
2761 system-wide init file in the directory specified by the
2762 --data-directory command-line option.
2764 * New command line options:
2766 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2767 other initialization files, unlike -nx which disables all of them.
2769 * Removed command line options
2771 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2774 * The 'ptype' and 'whatis' commands now accept an argument to control
2777 * 'info proc' now works on some core files.
2781 ** Vectors can be created with gdb.Type.vector.
2783 ** Python's atexit.register now works in GDB.
2785 ** Types can be pretty-printed via a Python API.
2787 ** Python 3 is now supported (in addition to Python 2.4 or later)
2789 ** New class gdb.Architecture exposes GDB's internal representation
2790 of architecture in the Python API.
2792 ** New method Frame.architecture returns the gdb.Architecture object
2793 corresponding to the frame's architecture.
2795 * New Python-based convenience functions:
2797 ** $_memeq(buf1, buf2, length)
2798 ** $_streq(str1, str2)
2800 ** $_regex(str, regex)
2802 * The 'cd' command now defaults to using '~' (the home directory) if not
2805 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2806 default for GCC since November 2000.
2808 * The command 'forward-search' can now be abbreviated as 'fo'.
2810 * The command 'info tracepoints' can now display 'installed on target'
2811 or 'not installed on target' for each non-pending location of tracepoint.
2813 * New configure options
2815 --enable-libmcheck/--disable-libmcheck
2816 By default, development versions are built with -lmcheck on hosts
2817 that support it, in order to help track memory corruption issues.
2818 Release versions, on the other hand, are built without -lmcheck
2819 by default. The --enable-libmcheck/--disable-libmcheck configure
2820 options allow the user to override that default.
2821 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2822 This configure option allows the user to build GDB with
2823 libbabeltrace using which GDB can read Common Trace Format data.
2825 * New commands (for set/show, see "New options" below)
2828 Catch signals. This is similar to "handle", but allows commands and
2829 conditions to be attached.
2832 List the BFDs known to GDB.
2834 python-interactive [command]
2836 Start a Python interactive prompt, or evaluate the optional command
2837 and print the result of expressions.
2840 "py" is a new alias for "python".
2842 enable type-printer [name]...
2843 disable type-printer [name]...
2844 Enable or disable type printers.
2848 ** For the Renesas Super-H architecture, the "regs" command has been removed
2849 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2854 set print type methods (on|off)
2855 show print type methods
2856 Control whether method declarations are displayed by "ptype".
2857 The default is to show them.
2859 set print type typedefs (on|off)
2860 show print type typedefs
2861 Control whether typedef definitions are displayed by "ptype".
2862 The default is to show them.
2864 set filename-display basename|relative|absolute
2865 show filename-display
2866 Control the way in which filenames is displayed.
2867 The default is "relative", which preserves previous behavior.
2869 set trace-buffer-size
2870 show trace-buffer-size
2871 Request target to change the size of trace buffer.
2873 set remote trace-buffer-size-packet auto|on|off
2874 show remote trace-buffer-size-packet
2875 Control the use of the remote protocol `QTBuffer:size' packet.
2879 Control display of debugging messages related to ARM AArch64.
2882 set debug coff-pe-read
2883 show debug coff-pe-read
2884 Control display of debugging messages related to reading of COFF/PE
2889 Control display of debugging messages related to Mach-O symbols
2892 set debug notification
2893 show debug notification
2894 Control display of debugging info for async remote notification.
2898 ** Command parameter changes are now notified using new async record
2899 "=cmd-param-changed".
2900 ** Trace frame changes caused by command "tfind" are now notified using
2901 new async record "=traceframe-changed".
2902 ** The creation, deletion and modification of trace state variables
2903 are now notified using new async records "=tsv-created",
2904 "=tsv-deleted" and "=tsv-modified".
2905 ** The start and stop of process record are now notified using new
2906 async record "=record-started" and "=record-stopped".
2907 ** Memory changes are now notified using new async record
2909 ** The data-disassemble command response will include a "fullname" field
2910 containing the absolute file name when source has been requested.
2911 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2912 command, to allow pattern filling of memory areas.
2913 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2914 library load/unload events.
2915 ** The response to breakpoint commands and breakpoint async records
2916 includes an "installed" field containing a boolean state about each
2917 non-pending tracepoint location is whether installed on target or not.
2918 ** Output of the "-trace-status" command includes a "trace-file" field
2919 containing the name of the trace file being examined. This field is
2920 optional, and only present when examining a trace file.
2921 ** The "fullname" field is now always present along with the "file" field,
2922 even if the file cannot be found by GDB.
2924 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2925 You must have the LZMA library available when configuring GDB for this
2926 feature to be enabled. For more information, see:
2927 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2929 * New remote packets
2932 Set the size of trace buffer. The remote stub reports support for this
2933 packet to gdb's qSupported query.
2936 Enable Branch Trace Store (BTS)-based branch tracing for the current
2937 thread. The remote stub reports support for this packet to gdb's
2941 Disable branch tracing for the current thread. The remote stub reports
2942 support for this packet to gdb's qSupported query.
2945 Read the traced branches for the current thread. The remote stub
2946 reports support for this packet to gdb's qSupported query.
2948 *** Changes in GDB 7.5
2950 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2951 for more x32 ABI info.
2953 * GDB now supports access to MIPS DSP registers on Linux targets.
2955 * GDB now supports debugging microMIPS binaries.
2957 * The "info os" command on GNU/Linux can now display information on
2958 several new classes of objects managed by the operating system:
2959 "info os procgroups" lists process groups
2960 "info os files" lists file descriptors
2961 "info os sockets" lists internet-domain sockets
2962 "info os shm" lists shared-memory regions
2963 "info os semaphores" lists semaphores
2964 "info os msg" lists message queues
2965 "info os modules" lists loaded kernel modules
2967 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2968 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2969 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2970 options and inspect the probe arguments using the new $_probe_arg family
2971 of convenience variables. You can obtain more information about SystemTap
2972 in <http://sourceware.org/systemtap/>.
2974 * GDB now supports reversible debugging on ARM, it allows you to
2975 debug basic ARM and THUMB instructions, and provides
2976 record/replay support.
2978 * The option "symbol-reloading" has been deleted as it is no longer used.
2982 ** GDB commands implemented in Python can now be put in command class
2985 ** The "maint set python print-stack on|off" is now deleted.
2987 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2988 apply "flag enum"-style pretty-printing to any enum.
2990 ** gdb.lookup_symbol can now work when there is no current frame.
2992 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2993 the source at which the symbol was defined.
2995 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2996 method 'value'. The former indicates whether the symbol needs a
2997 frame in order to compute its value, and the latter computes the
3000 ** A new method 'referenced_value' on gdb.Value objects which can
3001 dereference pointer as well as C++ reference values.
3003 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3004 which return the global and static blocks (as gdb.Block objects),
3005 of the underlying symbol table, respectively.
3007 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3008 object associated with a PC value.
3010 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3011 of the address range occupied by code for the current source line.
3013 * Go language support.
3014 GDB now supports debugging programs written in the Go programming
3017 * GDBserver now supports stdio connections.
3018 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3020 * The binary "gdbtui" can no longer be built or installed.
3021 Use "gdb -tui" instead.
3023 * GDB will now print "flag" enums specially. A flag enum is one where
3024 all the enumerator values have no bits in common when pairwise
3025 "and"ed. When printing a value whose type is a flag enum, GDB will
3026 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3027 (gdb) print (enum E) 3
3030 * The filename part of a linespec will now match trailing components
3031 of a source file name. For example, "break gcc/expr.c:1000" will
3032 now set a breakpoint in build/gcc/expr.c, but not
3033 build/libcpp/expr.c.
3035 * The "info proc" and "generate-core-file" commands will now also
3036 work on remote targets connected to GDBserver on Linux.
3038 * The command "info catch" has been removed. It has been disabled
3039 since December 2007.
3041 * The "catch exception" and "catch assert" commands now accept
3042 a condition at the end of the command, much like the "break"
3043 command does. For instance:
3045 (gdb) catch exception Constraint_Error if Barrier = True
3047 Previously, it was possible to add a condition to such catchpoints,
3048 but it had to be done as a second step, after the catchpoint had been
3049 created, using the "condition" command.
3051 * The "info static-tracepoint-marker" command will now also work on
3052 native Linux targets with in-process agent.
3054 * GDB can now set breakpoints on inlined functions.
3056 * The .gdb_index section has been updated to include symbols for
3057 inlined functions. GDB will ignore older .gdb_index sections by
3058 default, which could cause symbol files to be loaded more slowly
3059 until their .gdb_index sections can be recreated. The new command
3060 "set use-deprecated-index-sections on" will cause GDB to use any older
3061 .gdb_index sections it finds. This will restore performance, but the
3062 ability to set breakpoints on inlined functions will be lost in symbol
3063 files with older .gdb_index sections.
3065 The .gdb_index section has also been updated to record more information
3066 about each symbol. This speeds up the "info variables", "info functions"
3067 and "info types" commands when used with programs having the .gdb_index
3068 section, as well as speeding up debugging with shared libraries using
3069 the .gdb_index section.
3071 * Ada support for GDB/MI Variable Objects has been added.
3073 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3078 ** New command -info-os is the MI equivalent of "info os".
3080 ** Output logs ("set logging" and related) now include MI output.
3084 ** "set use-deprecated-index-sections on|off"
3085 "show use-deprecated-index-sections on|off"
3086 Controls the use of deprecated .gdb_index sections.
3088 ** "catch load" and "catch unload" can be used to stop when a shared
3089 library is loaded or unloaded, respectively.
3091 ** "enable count" can be used to auto-disable a breakpoint after
3094 ** "info vtbl" can be used to show the virtual method tables for
3095 C++ and Java objects.
3097 ** "explore" and its sub commands "explore value" and "explore type"
3098 can be used to recursively explore values and types of
3099 expressions. These commands are available only if GDB is
3100 configured with '--with-python'.
3102 ** "info auto-load" shows status of all kinds of auto-loaded files,
3103 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3104 sequences of commands files, "info auto-load python-scripts"
3105 shows status of auto-loading Python script files,
3106 "info auto-load local-gdbinit" shows status of loading init file
3107 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3108 status of inferior specific thread debugging shared library loading.
3110 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3111 and "show auto-load-scripts" commands have been deprecated, use their
3112 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3113 and "show auto-load python-scripts" counterparts instead.
3115 ** "dprintf location,format,args..." creates a dynamic printf, which
3116 is basically a breakpoint that does a printf and immediately
3117 resumes your program's execution, so it is like a printf that you
3118 can insert dynamically at runtime instead of at compiletime.
3120 ** "set print symbol"
3122 Controls whether GDB attempts to display the symbol, if any,
3123 corresponding to addresses it prints. This defaults to "on", but
3124 you can set it to "off" to restore GDB's previous behavior.
3126 * Deprecated commands
3128 ** For the Renesas Super-H architecture, the "regs" command has been
3129 deprecated, and "info all-registers" should be used instead.
3133 Renesas RL78 rl78-*-elf
3134 HP OpenVMS ia64 ia64-hp-openvms*
3136 * GDBserver supports evaluation of breakpoint conditions. When
3137 support is advertised by GDBserver, GDB may be told to send the
3138 breakpoint conditions in bytecode form to GDBserver. GDBserver
3139 will only report the breakpoint trigger to GDB when its condition
3144 set mips compression
3145 show mips compression
3146 Select the compressed ISA encoding used in functions that have no symbol
3147 information available. The encoding can be set to either of:
3150 and is updated automatically from ELF file flags if available.
3152 set breakpoint condition-evaluation
3153 show breakpoint condition-evaluation
3154 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3155 GDBserver ("target"). Default option "auto" chooses the most efficient
3157 This option can improve debugger efficiency depending on the speed of the
3161 Disable auto-loading globally.
3164 Show auto-loading setting of all kinds of auto-loaded files.
3166 set auto-load gdb-scripts on|off
3167 show auto-load gdb-scripts
3168 Control auto-loading of GDB canned sequences of commands files.
3170 set auto-load python-scripts on|off
3171 show auto-load python-scripts
3172 Control auto-loading of Python script files.
3174 set auto-load local-gdbinit on|off
3175 show auto-load local-gdbinit
3176 Control loading of init file (.gdbinit) from current directory.
3178 set auto-load libthread-db on|off
3179 show auto-load libthread-db
3180 Control auto-loading of inferior specific thread debugging shared library.
3182 set auto-load scripts-directory <dir1>[:<dir2>...]
3183 show auto-load scripts-directory
3184 Set a list of directories from which to load auto-loaded scripts.
3185 Automatically loaded Python scripts and GDB scripts are located in one
3186 of the directories listed by this option.
3187 The delimiter (':' above) may differ according to the host platform.
3189 set auto-load safe-path <dir1>[:<dir2>...]
3190 show auto-load safe-path
3191 Set a list of directories from which it is safe to auto-load files.
3192 The delimiter (':' above) may differ according to the host platform.
3194 set debug auto-load on|off
3195 show debug auto-load
3196 Control display of debugging info for auto-loading the files above.
3198 set dprintf-style gdb|call|agent
3200 Control the way in which a dynamic printf is performed; "gdb"
3201 requests a GDB printf command, while "call" causes dprintf to call a
3202 function in the inferior. "agent" requests that the target agent
3203 (such as GDBserver) do the printing.
3205 set dprintf-function <expr>
3206 show dprintf-function
3207 set dprintf-channel <expr>
3208 show dprintf-channel
3209 Set the function and optional first argument to the call when using
3210 the "call" style of dynamic printf.
3212 set disconnected-dprintf on|off
3213 show disconnected-dprintf
3214 Control whether agent-style dynamic printfs continue to be in effect
3215 after GDB disconnects.
3217 * New configure options
3219 --with-auto-load-dir
3220 Configure default value for the 'set auto-load scripts-directory'
3221 setting above. It defaults to '$debugdir:$datadir/auto-load',
3222 $debugdir representing global debugging info directories (available
3223 via 'show debug-file-directory') and $datadir representing GDB's data
3224 directory (available via 'show data-directory').
3226 --with-auto-load-safe-path
3227 Configure default value for the 'set auto-load safe-path' setting
3228 above. It defaults to the --with-auto-load-dir setting.
3230 --without-auto-load-safe-path
3231 Set 'set auto-load safe-path' to '/', effectively disabling this
3234 * New remote packets
3236 z0/z1 conditional breakpoints extension
3238 The z0/z1 breakpoint insertion packets have been extended to carry
3239 a list of conditional expressions over to the remote stub depending on the
3240 condition evaluation mode. The use of this extension can be controlled
3241 via the "set remote conditional-breakpoints-packet" command.
3245 Specify the signals which the remote stub may pass to the debugged
3246 program without GDB involvement.
3248 * New command line options
3250 --init-command=FILE, -ix Like --command, -x but execute it
3251 before loading inferior.
3252 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3253 execute it before loading inferior.
3255 *** Changes in GDB 7.4
3257 * GDB now handles ambiguous linespecs more consistently; the existing
3258 FILE:LINE support has been expanded to other types of linespecs. A
3259 breakpoint will now be set on all matching locations in all
3260 inferiors, and locations will be added or removed according to
3263 * GDB now allows you to skip uninteresting functions and files when
3264 stepping with the "skip function" and "skip file" commands.
3266 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3267 and "show remote hardware-watchpoint-length-limit". These allows to
3268 set or show the maximum length limit (in bytes) of a remote
3269 target hardware watchpoint.
3271 This allows e.g. to use "unlimited" hardware watchpoints with the
3272 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3273 watchpoints are slower than real hardware watchpoints but are
3274 significantly faster than gdb software watchpoints.
3278 ** The register_pretty_printer function in module gdb.printing now takes
3279 an optional `replace' argument. If True, the new printer replaces any
3282 ** The "maint set python print-stack on|off" command has been
3283 deprecated and will be deleted in GDB 7.5.
3284 A new command: "set python print-stack none|full|message" has
3285 replaced it. Additionally, the default for "print-stack" is
3286 now "message", which just prints the error message without
3289 ** A prompt substitution hook (prompt_hook) is now available to the
3292 ** A new Python module, gdb.prompt has been added to the GDB Python
3293 modules library. This module provides functionality for
3294 escape sequences in prompts (used by set/show
3295 extended-prompt). These escape sequences are replaced by their
3296 corresponding value.
3298 ** Python commands and convenience-functions located in
3299 'data-directory'/python/gdb/command and
3300 'data-directory'/python/gdb/function are now automatically loaded
3303 ** Blocks now provide four new attributes. global_block and
3304 static_block will return the global and static blocks
3305 respectively. is_static and is_global are boolean attributes
3306 that indicate if the block is one of those two types.
3308 ** Symbols now provide the "type" attribute, the type of the symbol.
3310 ** The "gdb.breakpoint" function has been deprecated in favor of
3313 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3314 of a function. This class is based on the "finish" command
3315 available in the CLI.
3317 ** Type objects for struct and union types now allow access to
3318 the fields using standard Python dictionary (mapping) methods.
3319 For example, "some_type['myfield']" now works, as does
3320 "some_type.items()".
3322 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3325 ** A new function, "deep_items" has been added to the gdb.types
3326 module in the GDB Python modules library. This function returns
3327 an iterator over the fields of a struct or union type. Unlike
3328 the standard Python "iteritems" method, it will recursively traverse
3329 any anonymous fields.
3333 ** "*stopped" events can report several new "reason"s, such as
3336 ** Breakpoint changes are now notified using new async records, like
3337 "=breakpoint-modified".
3339 ** New command -ada-task-info.
3341 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3342 $sdir specifies the default system locations of shared libraries.
3343 $pdir specifies the directory where the libpthread used by the application
3346 GDB no longer looks in $sdir and $pdir after it has searched the directories
3347 mentioned in libthread-db-search-path. If you want to search those
3348 directories, they must be specified in libthread-db-search-path.
3349 The default value of libthread-db-search-path on GNU/Linux and Solaris
3350 systems is now "$sdir:$pdir".
3352 $pdir is not supported by gdbserver, it is currently ignored.
3353 $sdir is supported by gdbserver.
3355 * New configure option --with-iconv-bin.
3356 When using the internationalization support like the one in the GNU C
3357 library, GDB will invoke the "iconv" program to get a list of supported
3358 character sets. If this program lives in a non-standard location, one can
3359 use this option to specify where to find it.
3361 * When natively debugging programs on PowerPC BookE processors running
3362 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3363 watchpoints, which specify a mask in addition to an address to watch.
3364 The mask specifies that some bits of an address (the bits which are
3365 reset in the mask) should be ignored when matching the address accessed
3366 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3367 section in the user manual for more details.
3369 * The new option --once causes GDBserver to stop listening for connections once
3370 the first connection is made. The listening port used by GDBserver will
3371 become available after that.
3373 * New commands "info macros" and "alias" have been added.
3375 * New function parameters suffix @entry specifies value of function parameter
3376 at the time the function got called. Entry values are available only since
3382 "!" is now an alias of the "shell" command.
3383 Note that no space is needed between "!" and SHELL COMMAND.
3387 watch EXPRESSION mask MASK_VALUE
3388 The watch command now supports the mask argument which allows creation
3389 of masked watchpoints, if the current architecture supports this feature.
3391 info auto-load-scripts [REGEXP]
3392 This command was formerly named "maintenance print section-scripts".
3393 It is now generally useful and is no longer a maintenance-only command.
3395 info macro [-all] [--] MACRO
3396 The info macro command has new options `-all' and `--'. The first for
3397 printing all definitions of a macro. The second for explicitly specifying
3398 the end of arguments and the beginning of the macro name in case the macro
3399 name starts with a hyphen.
3401 collect[/s] EXPRESSIONS
3402 The tracepoint collect command now takes an optional modifier "/s"
3403 that directs it to dereference pointer-to-character types and
3404 collect the bytes of memory up to a zero byte. The behavior is
3405 similar to what you see when you use the regular print command on a
3406 string. An optional integer following the "/s" sets a bound on the
3407 number of bytes that will be collected.
3410 The trace start command now interprets any supplied arguments as a
3411 note to be recorded with the trace run, with an effect similar to
3412 setting the variable trace-notes.
3415 The trace stop command now interprets any arguments as a note to be
3416 mentioned along with the tstatus report that the trace was stopped
3417 with a command. The effect is similar to setting the variable
3420 * Tracepoints can now be enabled and disabled at any time after a trace
3421 experiment has been started using the standard "enable" and "disable"
3422 commands. It is now possible to start a trace experiment with no enabled
3423 tracepoints; GDB will display a warning, but will allow the experiment to
3424 begin, assuming that tracepoints will be enabled as needed while the trace
3427 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3428 locations with 4-byte instructions, when they were previously
3429 limited to locations with instructions of 5 bytes or longer.
3433 set debug dwarf2-read
3434 show debug dwarf2-read
3435 Turns on or off display of debugging messages related to reading
3436 DWARF debug info. The default is off.
3438 set debug symtab-create
3439 show debug symtab-create
3440 Turns on or off display of debugging messages related to symbol table
3441 creation. The default is off.
3444 show extended-prompt
3445 Set the GDB prompt, and allow escape sequences to be inserted to
3446 display miscellaneous information (see 'help set extended-prompt'
3447 for the list of sequences). This prompt (and any information
3448 accessed through the escape sequences) is updated every time the
3449 prompt is displayed.
3451 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3452 show print entry-values
3453 Set printing of frame argument values at function entry. In some cases
3454 GDB can determine the value of function argument which was passed by the
3455 function caller, even if the value was modified inside the called function.
3457 set debug entry-values
3458 show debug entry-values
3459 Control display of debugging info for determining frame argument values at
3460 function entry and virtual tail call frames.
3462 set basenames-may-differ
3463 show basenames-may-differ
3464 Set whether a source file may have multiple base names.
3465 (A "base name" is the name of a file with the directory part removed.
3466 Example: The base name of "/home/user/hello.c" is "hello.c".)
3467 If set, GDB will canonicalize file names (e.g., expand symlinks)
3468 before comparing them. Canonicalization is an expensive operation,
3469 but it allows the same file be known by more than one base name.
3470 If not set (the default), all source files are assumed to have just
3471 one base name, and gdb will do file name comparisons more efficiently.
3477 Set a user name and notes for the current and any future trace runs.
3478 This is useful for long-running and/or disconnected traces, to
3479 inform others (or yourself) as to who is running the trace, supply
3480 contact information, or otherwise explain what is going on.
3482 set trace-stop-notes
3483 show trace-stop-notes
3484 Set a note attached to the trace run, that is displayed when the
3485 trace has been stopped by a tstop command. This is useful for
3486 instance as an explanation, if you are stopping a trace run that was
3487 started by someone else.
3489 * New remote packets
3493 Dynamically enable a tracepoint in a started trace experiment.
3497 Dynamically disable a tracepoint in a started trace experiment.
3501 Set the user and notes of the trace run.
3505 Query the current status of a tracepoint.
3509 Query the minimum length of instruction at which a fast tracepoint may
3512 * Dcache size (number of lines) and line-size are now runtime-configurable
3513 via "set dcache line" and "set dcache line-size" commands.
3517 Texas Instruments TMS320C6x tic6x-*-*
3521 Renesas RL78 rl78-*-elf
3523 *** Changes in GDB 7.3.1
3525 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3527 *** Changes in GDB 7.3
3529 * GDB has a new command: "thread find [REGEXP]".
3530 It finds the thread id whose name, target id, or thread extra info
3531 matches the given regular expression.
3533 * The "catch syscall" command now works on mips*-linux* targets.
3535 * The -data-disassemble MI command now supports modes 2 and 3 for
3536 dumping the instruction opcodes.
3538 * New command line options
3540 -data-directory DIR Specify DIR as the "data-directory".
3541 This is mostly for testing purposes.
3543 * The "maint set python auto-load on|off" command has been renamed to
3544 "set auto-load-scripts on|off".
3546 * GDB has a new command: "set directories".
3547 It is like the "dir" command except that it replaces the
3548 source path list instead of augmenting it.
3550 * GDB now understands thread names.
3552 On GNU/Linux, "info threads" will display the thread name as set by
3553 prctl or pthread_setname_np.
3555 There is also a new command, "thread name", which can be used to
3556 assign a name internally for GDB to display.
3559 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3560 has been integrated into GDB.
3564 ** The function gdb.Write now accepts an optional keyword 'stream'.
3565 This keyword, when provided, will direct the output to either
3566 stdout, stderr, or GDB's logging output.
3568 ** Parameters can now be be sub-classed in Python, and in particular
3569 you may implement the get_set_doc and get_show_doc functions.
3570 This improves how Parameter set/show documentation is processed
3571 and allows for more dynamic content.
3573 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3574 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3575 have an is_valid method.
3577 ** Breakpoints can now be sub-classed in Python, and in particular
3578 you may implement a 'stop' function that is executed each time
3579 the inferior reaches that breakpoint.
3581 ** New function gdb.lookup_global_symbol looks up a global symbol.
3583 ** GDB values in Python are now callable if the value represents a
3584 function. For example, if 'some_value' represents a function that
3585 takes two integer parameters and returns a value, you can call
3586 that function like so:
3588 result = some_value (10,20)
3590 ** Module gdb.types has been added.
3591 It contains a collection of utilities for working with gdb.Types objects:
3592 get_basic_type, has_field, make_enum_dict.
3594 ** Module gdb.printing has been added.
3595 It contains utilities for writing and registering pretty-printers.
3596 New classes: PrettyPrinter, SubPrettyPrinter,
3597 RegexpCollectionPrettyPrinter.
3598 New function: register_pretty_printer.
3600 ** New commands "info pretty-printers", "enable pretty-printer" and
3601 "disable pretty-printer" have been added.
3603 ** gdb.parameter("directories") is now available.
3605 ** New function gdb.newest_frame returns the newest frame in the
3608 ** The gdb.InferiorThread class has a new "name" attribute. This
3609 holds the thread's name.
3611 ** Python Support for Inferior events.
3612 Python scripts can add observers to be notified of events
3613 occurring in the process being debugged.
3614 The following events are currently supported:
3615 - gdb.events.cont Continue event.
3616 - gdb.events.exited Inferior exited event.
3617 - gdb.events.stop Signal received, and Breakpoint hit events.
3621 ** GDB now puts template parameters in scope when debugging in an
3622 instantiation. For example, if you have:
3624 template<int X> int func (void) { return X; }
3626 then if you step into func<5>, "print X" will show "5". This
3627 feature requires proper debuginfo support from the compiler; it
3628 was added to GCC 4.5.
3630 ** The motion commands "next", "finish", "until", and "advance" now
3631 work better when exceptions are thrown. In particular, GDB will
3632 no longer lose control of the inferior; instead, the GDB will
3633 stop the inferior at the point at which the exception is caught.
3634 This functionality requires a change in the exception handling
3635 code that was introduced in GCC 4.5.
3637 * GDB now follows GCC's rules on accessing volatile objects when
3638 reading or writing target state during expression evaluation.
3639 One notable difference to prior behavior is that "print x = 0"
3640 no longer generates a read of x; the value of the assignment is
3641 now always taken directly from the value being assigned.
3643 * GDB now has some support for using labels in the program's source in
3644 linespecs. For instance, you can use "advance label" to continue
3645 execution to a label.
3647 * GDB now has support for reading and writing a new .gdb_index
3648 section. This section holds a fast index of DWARF debugging
3649 information and can be used to greatly speed up GDB startup and
3650 operation. See the documentation for `save gdb-index' for details.
3652 * The "watch" command now accepts an optional "-location" argument.
3653 When used, this causes GDB to watch the memory referred to by the
3654 expression. Such a watchpoint is never deleted due to it going out
3657 * GDB now supports thread debugging of core dumps on GNU/Linux.
3659 GDB now activates thread debugging using the libthread_db library
3660 when debugging GNU/Linux core dumps, similarly to when debugging
3661 live processes. As a result, when debugging a core dump file, GDB
3662 is now able to display pthread_t ids of threads. For example, "info
3663 threads" shows the same output as when debugging the process when it
3664 was live. In earlier releases, you'd see something like this:
3667 * 1 LWP 6780 main () at main.c:10
3669 While now you see this:
3672 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3674 It is also now possible to inspect TLS variables when debugging core
3677 When debugging a core dump generated on a machine other than the one
3678 used to run GDB, you may need to point GDB at the correct
3679 libthread_db library with the "set libthread-db-search-path"
3680 command. See the user manual for more details on this command.
3682 * When natively debugging programs on PowerPC BookE processors running
3683 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3684 which stop execution of the inferior whenever it executes an instruction
3685 at any address within the specified range. See the "PowerPC Embedded"
3686 section in the user manual for more details.
3688 * New features in the GDB remote stub, GDBserver
3690 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3691 and i686 LynxOS (version 5.x).
3693 ** GDBserver is now supported on Blackfin Linux.
3695 * New native configurations
3697 ia64 HP-UX ia64-*-hpux*
3701 Analog Devices, Inc. Blackfin Processor bfin-*
3703 * Ada task switching is now supported on sparc-elf targets when
3704 debugging a program using the Ravenscar Profile. For more information,
3705 see the "Tasking Support when using the Ravenscar Profile" section
3706 in the GDB user manual.
3708 * Guile support was removed.
3710 * New features in the GNU simulator
3712 ** The --map-info flag lists all known core mappings.
3714 ** CFI flashes may be simulated via the "cfi" device.
3716 *** Changes in GDB 7.2
3718 * Shared library support for remote targets by default
3720 When GDB is configured for a generic, non-OS specific target, like
3721 for example, --target=arm-eabi or one of the many *-*-elf targets,
3722 GDB now queries remote stubs for loaded shared libraries using the
3723 `qXfer:libraries:read' packet. Previously, shared library support
3724 was always disabled for such configurations.
3728 ** Argument Dependent Lookup (ADL)
3730 In C++ ADL lookup directs function search to the namespaces of its
3731 arguments even if the namespace has not been imported.
3741 Here the compiler will search for `foo' in the namespace of 'b'
3742 and find A::foo. GDB now supports this. This construct is commonly
3743 used in the Standard Template Library for operators.
3745 ** Improved User Defined Operator Support
3747 In addition to member operators, GDB now supports lookup of operators
3748 defined in a namespace and imported with a `using' directive, operators
3749 defined in the global scope, operators imported implicitly from an
3750 anonymous namespace, and the ADL operators mentioned in the previous
3752 GDB now also supports proper overload resolution for all the previously
3753 mentioned flavors of operators.
3755 ** static const class members
3757 Printing of static const class members that are initialized in the
3758 class definition has been fixed.
3760 * Windows Thread Information Block access.
3762 On Windows targets, GDB now supports displaying the Windows Thread
3763 Information Block (TIB) structure. This structure is visible either
3764 by using the new command `info w32 thread-information-block' or, by
3765 dereferencing the new convenience variable named `$_tlb', a
3766 thread-specific pointer to the TIB. This feature is also supported
3767 when remote debugging using GDBserver.
3769 * Static tracepoints
3771 Static tracepoints are calls in the user program into a tracing
3772 library. One such library is a port of the LTTng kernel tracer to
3773 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3774 When debugging with GDBserver, GDB now supports combining the GDB
3775 tracepoint machinery with such libraries. For example: the user can
3776 use GDB to probe a static tracepoint marker (a call from the user
3777 program into the tracing library) with the new "strace" command (see
3778 "New commands" below). This creates a "static tracepoint" in the
3779 breakpoint list, that can be manipulated with the same feature set
3780 as fast and regular tracepoints. E.g., collect registers, local and
3781 global variables, collect trace state variables, and define
3782 tracepoint conditions. In addition, the user can collect extra
3783 static tracepoint marker specific data, by collecting the new
3784 $_sdata internal variable. When analyzing the trace buffer, you can
3785 inspect $_sdata like any other variable available to GDB. For more
3786 information, see the "Tracepoints" chapter in GDB user manual. New
3787 remote packets have been defined to support static tracepoints, see
3788 the "New remote packets" section below.
3790 * Better reconstruction of tracepoints after disconnected tracing
3792 GDB will attempt to download the original source form of tracepoint
3793 definitions when starting a trace run, and then will upload these
3794 upon reconnection to the target, resulting in a more accurate
3795 reconstruction of the tracepoints that are in use on the target.
3799 You can now exercise direct control over the ways that GDB can
3800 affect your program. For instance, you can disallow the setting of
3801 breakpoints, so that the program can run continuously (assuming
3802 non-stop mode). In addition, the "observer" variable is available
3803 to switch all of the different controls; in observer mode, GDB
3804 cannot affect the target's behavior at all, which is useful for
3805 tasks like diagnosing live systems in the field.
3807 * The new convenience variable $_thread holds the number of the
3810 * New remote packets
3814 Return the address of the Windows Thread Information Block of a given thread.
3818 In response to several of the tracepoint packets, the target may now
3819 also respond with a number of intermediate `qRelocInsn' request
3820 packets before the final result packet, to have GDB handle
3821 relocating an instruction to execute at a different address. This
3822 is particularly useful for stubs that support fast tracepoints. GDB
3823 reports support for this feature in the qSupported packet.
3827 List static tracepoint markers in the target program.
3831 List static tracepoint markers at a given address in the target
3834 qXfer:statictrace:read
3836 Read the static trace data collected (by a `collect $_sdata'
3837 tracepoint action). The remote stub reports support for this packet
3838 to gdb's qSupported query.
3842 Send the current settings of GDB's permission flags.
3846 Send part of the source (textual) form of a tracepoint definition,
3847 which includes location, conditional, and action list.
3849 * The source command now accepts a -s option to force searching for the
3850 script in the source search path even if the script name specifies
3853 * New features in the GDB remote stub, GDBserver
3855 - GDBserver now support tracepoints (including fast tracepoints, and
3856 static tracepoints). The feature is currently supported by the
3857 i386-linux and amd64-linux builds. See the "Tracepoints support
3858 in gdbserver" section in the manual for more information.
3860 GDBserver JIT compiles the tracepoint's conditional agent
3861 expression bytecode into native code whenever possible for low
3862 overhead dynamic tracepoints conditionals. For such tracepoints,
3863 an expression that examines program state is evaluated when the
3864 tracepoint is reached, in order to determine whether to capture
3865 trace data. If the condition is simple and false, processing the
3866 tracepoint finishes very quickly and no data is gathered.
3868 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3869 for static tracepoints support.
3871 - GDBserver now supports x86_64 Windows 64-bit debugging.
3873 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3874 it understands register description.
3876 * The --batch flag now disables pagination and queries.
3878 * X86 general purpose registers
3880 GDB now supports reading/writing byte, word and double-word x86
3881 general purpose registers directly. This means you can use, say,
3882 $ah or $ax to refer, respectively, to the byte register AH and
3883 16-bit word register AX that are actually portions of the 32-bit
3884 register EAX or 64-bit register RAX.
3886 * The `commands' command now accepts a range of breakpoints to modify.
3887 A plain `commands' following a command that creates multiple
3888 breakpoints affects all the breakpoints set by that command. This
3889 applies to breakpoints set by `rbreak', and also applies when a
3890 single `break' command creates multiple breakpoints (e.g.,
3891 breakpoints on overloaded c++ functions).
3893 * The `rbreak' command now accepts a filename specification as part of
3894 its argument, limiting the functions selected by the regex to those
3895 in the specified file.
3897 * Support for remote debugging Windows and SymbianOS shared libraries
3898 from Unix hosts has been improved. Non Windows GDB builds now can
3899 understand target reported file names that follow MS-DOS based file
3900 system semantics, such as file names that include drive letters and
3901 use the backslash character as directory separator. This makes it
3902 possible to transparently use the "set sysroot" and "set
3903 solib-search-path" on Unix hosts to point as host copies of the
3904 target's shared libraries. See the new command "set
3905 target-file-system-kind" described below, and the "Commands to
3906 specify files" section in the user manual for more information.
3910 eval template, expressions...
3911 Convert the values of one or more expressions under the control
3912 of the string template to a command line, and call it.
3914 set target-file-system-kind unix|dos-based|auto
3915 show target-file-system-kind
3916 Set or show the assumed file system kind for target reported file
3919 save breakpoints <filename>
3920 Save all current breakpoint definitions to a file suitable for use
3921 in a later debugging session. To read the saved breakpoint
3922 definitions, use the `source' command.
3924 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3927 info static-tracepoint-markers
3928 Display information about static tracepoint markers in the target.
3930 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3931 Define a static tracepoint by probing a marker at the given
3932 function, line, address, or marker ID.
3936 Enable and disable observer mode.
3938 set may-write-registers on|off
3939 set may-write-memory on|off
3940 set may-insert-breakpoints on|off
3941 set may-insert-tracepoints on|off
3942 set may-insert-fast-tracepoints on|off
3943 set may-interrupt on|off
3944 Set individual permissions for GDB effects on the target. Note that
3945 some of these settings can have undesirable or surprising
3946 consequences, particularly when changed in the middle of a session.
3947 For instance, disabling the writing of memory can prevent
3948 breakpoints from being inserted, cause single-stepping to fail, or
3949 even crash your program, if you disable after breakpoints have been
3950 inserted. However, GDB should not crash.
3952 set record memory-query on|off
3953 show record memory-query
3954 Control whether to stop the inferior if memory changes caused
3955 by an instruction cannot be recorded.
3960 The disassemble command now supports "start,+length" form of two arguments.
3964 ** GDB now provides a new directory location, called the python directory,
3965 where Python scripts written for GDB can be installed. The location
3966 of that directory is <data-directory>/python, where <data-directory>
3967 is the GDB data directory. For more details, see section `Scripting
3968 GDB using Python' in the manual.
3970 ** The GDB Python API now has access to breakpoints, symbols, symbol
3971 tables, program spaces, inferiors, threads and frame's code blocks.
3972 Additionally, GDB Parameters can now be created from the API, and
3973 manipulated via set/show in the CLI.
3975 ** New functions gdb.target_charset, gdb.target_wide_charset,
3976 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3978 ** New exception gdb.GdbError.
3980 ** Pretty-printers are now also looked up in the current program space.
3982 ** Pretty-printers can now be individually enabled and disabled.
3984 ** GDB now looks for names of Python scripts to auto-load in a
3985 special section named `.debug_gdb_scripts', in addition to looking
3986 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3988 * Tracepoint actions were unified with breakpoint commands. In particular,
3989 there are no longer differences in "info break" output for breakpoints and
3990 tracepoints and the "commands" command can be used for both tracepoints and
3991 regular breakpoints.
3995 ARM Symbian arm*-*-symbianelf*
3997 * D language support.
3998 GDB now supports debugging programs written in the D programming
4001 * GDB now supports the extended ptrace interface for PowerPC which is
4002 available since Linux kernel version 2.6.34. This automatically enables
4003 any hardware breakpoints and additional hardware watchpoints available in
4004 the processor. The old ptrace interface exposes just one hardware
4005 watchpoint and no hardware breakpoints.
4007 * GDB is now able to use the Data Value Compare (DVC) register available on
4008 embedded PowerPC processors to implement in hardware simple watchpoint
4009 conditions of the form:
4011 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4013 This works in native GDB running on Linux kernels with the extended ptrace
4014 interface mentioned above.
4016 *** Changes in GDB 7.1
4020 ** Namespace Support
4022 GDB now supports importing of namespaces in C++. This enables the
4023 user to inspect variables from imported namespaces. Support for
4024 namepace aliasing has also been added. So, if a namespace is
4025 aliased in the current scope (e.g. namepace C=A; ) the user can
4026 print variables using the alias (e.g. (gdb) print C::x).
4030 All known bugs relating to the printing of virtual base class were
4031 fixed. It is now possible to call overloaded static methods using a
4036 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4037 and reinterpret_cast<> are now handled by the C++ expression parser.
4041 Xilinx MicroBlaze microblaze-*-*
4046 Xilinx MicroBlaze microblaze
4049 * Multi-program debugging.
4051 GDB now has support for multi-program (a.k.a. multi-executable or
4052 multi-exec) debugging. This allows for debugging multiple inferiors
4053 simultaneously each running a different program under the same GDB
4054 session. See "Debugging Multiple Inferiors and Programs" in the
4055 manual for more information. This implied some user visible changes
4056 in the multi-inferior support. For example, "info inferiors" now
4057 lists inferiors that are not running yet or that have exited
4058 already. See also "New commands" and "New options" below.
4060 * New tracing features
4062 GDB's tracepoint facility now includes several new features:
4064 ** Trace state variables
4066 GDB tracepoints now include support for trace state variables, which
4067 are variables managed by the target agent during a tracing
4068 experiment. They are useful for tracepoints that trigger each
4069 other, so for instance one tracepoint can count hits in a variable,
4070 and then a second tracepoint has a condition that is true when the
4071 count reaches a particular value. Trace state variables share the
4072 $-syntax of GDB convenience variables, and can appear in both
4073 tracepoint actions and condition expressions. Use the "tvariable"
4074 command to create, and "info tvariables" to view; see "Trace State
4075 Variables" in the manual for more detail.
4079 GDB now includes an option for defining fast tracepoints, which
4080 targets may implement more efficiently, such as by installing a jump
4081 into the target agent rather than a trap instruction. The resulting
4082 speedup can be by two orders of magnitude or more, although the
4083 tradeoff is that some program locations on some target architectures
4084 might not allow fast tracepoint installation, for instance if the
4085 instruction to be replaced is shorter than the jump. To request a
4086 fast tracepoint, use the "ftrace" command, with syntax identical to
4087 the regular trace command.
4089 ** Disconnected tracing
4091 It is now possible to detach GDB from the target while it is running
4092 a trace experiment, then reconnect later to see how the experiment
4093 is going. In addition, a new variable disconnected-tracing lets you
4094 tell the target agent whether to continue running a trace if the
4095 connection is lost unexpectedly.
4099 GDB now has the ability to save the trace buffer into a file, and
4100 then use that file as a target, similarly to you can do with
4101 corefiles. You can select trace frames, print data that was
4102 collected in them, and use tstatus to display the state of the
4103 tracing run at the moment that it was saved. To create a trace
4104 file, use "tsave <filename>", and to use it, do "target tfile
4107 ** Circular trace buffer
4109 You can ask the target agent to handle the trace buffer as a
4110 circular buffer, discarding the oldest trace frames to make room for
4111 newer ones, by setting circular-trace-buffer to on. This feature may
4112 not be available for all target agents.
4117 The disassemble command, when invoked with two arguments, now requires
4118 the arguments to be comma-separated.
4121 The info variables command now displays variable definitions. Files
4122 which only declare a variable are not shown.
4125 The source command is now capable of sourcing Python scripts.
4126 This feature is dependent on the debugger being build with Python
4129 Related to this enhancement is also the introduction of a new command
4130 "set script-extension" (see below).
4132 * New commands (for set/show, see "New options" below)
4134 record save [<FILENAME>]
4135 Save a file (in core file format) containing the process record
4136 execution log for replay debugging at a later time.
4138 record restore <FILENAME>
4139 Restore the process record execution log that was saved at an
4140 earlier time, for replay debugging.
4142 add-inferior [-copies <N>] [-exec <FILENAME>]
4145 clone-inferior [-copies <N>] [ID]
4146 Make a new inferior ready to execute the same program another
4147 inferior has loaded.
4152 maint info program-spaces
4153 List the program spaces loaded into GDB.
4155 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4156 show remote interrupt-sequence
4157 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4158 as the sequence to the remote target in order to interrupt the execution.
4159 Ctrl-C is a default. Some system prefers BREAK which is high level of
4160 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4161 Magic SysRq g. It is BREAK signal and character 'g'.
4163 set remote interrupt-on-connect [on | off]
4164 show remote interrupt-on-connect
4165 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4166 remote target when gdb connects to it. This is needed when you debug
4169 set remotebreak [on | off]
4171 Deprecated. Use "set/show remote interrupt-sequence" instead.
4173 tvariable $NAME [ = EXP ]
4174 Create or modify a trace state variable.
4177 List trace state variables and their values.
4179 delete tvariable $NAME ...
4180 Delete one or more trace state variables.
4183 Evaluate the given expressions without collecting anything into the
4184 trace buffer. (Valid in tracepoint actions only.)
4186 ftrace FN / FILE:LINE / *ADDR
4187 Define a fast tracepoint at the given function, line, or address.
4189 * New expression syntax
4191 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4192 GDB now parses 0b101010 identically with 42.
4196 set follow-exec-mode new|same
4197 show follow-exec-mode
4198 Control whether GDB reuses the same inferior across an exec call or
4199 creates a new one. This is useful to be able to restart the old
4200 executable after the inferior having done an exec call.
4202 set default-collect EXPR, ...
4203 show default-collect
4204 Define a list of expressions to be collected at each tracepoint.
4205 This is a useful way to ensure essential items are not overlooked,
4206 such as registers or a critical global variable.
4208 set disconnected-tracing
4209 show disconnected-tracing
4210 If set to 1, the target is instructed to continue tracing if it
4211 loses its connection to GDB. If 0, the target is to stop tracing
4214 set circular-trace-buffer
4215 show circular-trace-buffer
4216 If set to on, the target is instructed to use a circular trace buffer
4217 and discard the oldest trace frames instead of stopping the trace due
4218 to a full trace buffer. If set to off, the trace stops when the buffer
4219 fills up. Some targets may not support this.
4221 set script-extension off|soft|strict
4222 show script-extension
4223 If set to "off", the debugger does not perform any script language
4224 recognition, and all sourced files are assumed to be GDB scripts.
4225 If set to "soft" (the default), files are sourced according to
4226 filename extension, falling back to GDB scripts if the first
4228 If set to "strict", files are sourced according to filename extension.
4230 set ada trust-PAD-over-XVS on|off
4231 show ada trust-PAD-over-XVS
4232 If off, activate a workaround against a bug in the debugging information
4233 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4234 the GCC sources for more information about the GNAT encoding and
4235 PAD types in particular). It is always safe to set this option to
4236 off, but this introduces a slight performance penalty. The default
4239 * Python API Improvements
4241 ** GDB provides the new class gdb.LazyString. This is useful in
4242 some pretty-printing cases. The new method gdb.Value.lazy_string
4243 provides a simple way to create objects of this type.
4245 ** The fields returned by gdb.Type.fields now have an
4246 `is_base_class' attribute.
4248 ** The new method gdb.Type.range returns the range of an array type.
4250 ** The new method gdb.parse_and_eval can be used to parse and
4251 evaluate an expression.
4253 * New remote packets
4256 Define a trace state variable.
4259 Get the current value of a trace state variable.
4262 Set desired tracing behavior upon disconnection.
4265 Set the trace buffer to be linear or circular.
4268 Get data about the tracepoints currently in use.
4272 Process record now works correctly with hardware watchpoints.
4274 Multiple bug fixes have been made to the mips-irix port, making it
4275 much more reliable. In particular:
4276 - Debugging threaded applications is now possible again. Previously,
4277 GDB would hang while starting the program, or while waiting for
4278 the program to stop at a breakpoint.
4279 - Attaching to a running process no longer hangs.
4280 - An error occurring while loading a core file has been fixed.
4281 - Changing the value of the PC register now works again. This fixes
4282 problems observed when using the "jump" command, or when calling
4283 a function from GDB, or even when assigning a new value to $pc.
4284 - With the "finish" and "return" commands, the return value for functions
4285 returning a small array is now correctly printed.
4286 - It is now possible to break on shared library code which gets executed
4287 during a shared library init phase (code executed while executing
4288 their .init section). Previously, the breakpoint would have no effect.
4289 - GDB is now able to backtrace through the signal handler for
4290 non-threaded programs.
4292 PIE (Position Independent Executable) programs debugging is now supported.
4293 This includes debugging execution of PIC (Position Independent Code) shared
4294 libraries although for that, it should be possible to run such libraries as an
4297 *** Changes in GDB 7.0
4299 * GDB now has an interface for JIT compilation. Applications that
4300 dynamically generate code can create symbol files in memory and register
4301 them with GDB. For users, the feature should work transparently, and
4302 for JIT developers, the interface is documented in the GDB manual in the
4303 "JIT Compilation Interface" chapter.
4305 * Tracepoints may now be conditional. The syntax is as for
4306 breakpoints; either an "if" clause appended to the "trace" command,
4307 or the "condition" command is available. GDB sends the condition to
4308 the target for evaluation using the same bytecode format as is used
4309 for tracepoint actions.
4311 * The disassemble command now supports: an optional /r modifier, print the
4312 raw instructions in hex as well as in symbolic form, and an optional /m
4313 modifier to print mixed source+assembly.
4315 * Process record and replay
4317 In a architecture environment that supports ``process record and
4318 replay'', ``process record and replay'' target can record a log of
4319 the process execution, and replay it with both forward and reverse
4322 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4323 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4324 set execution-direction {forward|reverse}, for targets that support
4327 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4328 feature is available with a native GDB running on kernel version
4331 * GDB now has support for multi-byte and wide character sets on the
4332 target. Strings whose character type is wchar_t, char16_t, or
4333 char32_t are now correctly printed. GDB supports wide- and unicode-
4334 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4335 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4336 `printf'. This feature requires iconv to work properly; if your
4337 system does not have a working iconv, GDB can use GNU libiconv. See
4338 the installation instructions for more information.
4340 * GDB now supports automatic retrieval of shared library files from
4341 remote targets. To use this feature, specify a system root that begins
4342 with the `remote:' prefix, either via the `set sysroot' command or via
4343 the `--with-sysroot' configure-time option.
4345 * "info sharedlibrary" now takes an optional regex of libraries to show,
4346 and it now reports if a shared library has no debugging information.
4348 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4349 now complete on file names.
4351 * When completing in expressions, gdb will attempt to limit
4352 completions to allowable structure or union fields, where appropriate.
4353 For instance, consider:
4355 # struct example { int f1; double f2; };
4356 # struct example variable;
4359 If the user types TAB at the end of this command line, the available
4360 completions will be "f1" and "f2".
4362 * Inlined functions are now supported. They show up in backtraces, and
4363 the "step", "next", and "finish" commands handle them automatically.
4365 * GDB now supports the token-splicing (##) and stringification (#)
4366 operators when expanding macros. It also supports variable-arity
4369 * GDB now supports inspecting extra signal information, exported by
4370 the new $_siginfo convenience variable. The feature is currently
4371 implemented on linux ARM, i386 and amd64.
4373 * GDB can now display the VFP floating point registers and NEON vector
4374 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4375 can provide these registers (requires Linux 2.6.30 or later). Remote
4376 and simulator targets may also provide them.
4378 * New remote packets
4381 Search memory for a sequence of bytes.
4384 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4385 operation over reliable transport links. Use of this packet is
4386 controlled by the `set remote noack-packet' command.
4389 Kill the process with the specified process ID. Use this in preference
4390 to `k' when multiprocess protocol extensions are supported.
4393 Obtains additional operating system information
4397 Read or write additional signal information.
4399 * Removed remote protocol undocumented extension
4401 An undocumented extension to the remote protocol's `S' stop reply
4402 packet that permitted the stub to pass a process id was removed.
4403 Remote servers should use the `T' stop reply packet instead.
4405 * GDB now supports multiple function calling conventions according to the
4406 DWARF-2 DW_AT_calling_convention function attribute.
4408 * The SH target utilizes the aforementioned change to distinguish between gcc
4409 and Renesas calling convention. It also adds the new CLI commands
4410 `set/show sh calling-convention'.
4412 * GDB can now read compressed debug sections, as produced by GNU gold
4413 with the --compress-debug-sections=zlib flag.
4415 * 64-bit core files are now supported on AIX.
4417 * Thread switching is now supported on Tru64.
4419 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4420 which will be allocated using malloc later in program execution.
4422 * The qXfer:libraries:read remote protocol packet now allows passing a
4423 list of section offsets.
4425 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4426 conditions handling signals delivered during attach or thread creation
4427 have also been fixed.
4429 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4430 From the user's standpoint, all unqualified instances of True and False
4431 are treated as the standard definitions, regardless of context.
4433 * GDB now parses C++ symbol and type names more flexibly. For
4436 template<typename T> class C { };
4439 GDB will now correctly handle all of:
4441 ptype C<char const *>
4442 ptype C<char const*>
4443 ptype C<const char *>
4444 ptype C<const char*>
4446 * New features in the GDB remote stub, gdbserver
4448 - The "--wrapper" command-line argument tells gdbserver to use a
4449 wrapper program to launch programs for debugging.
4451 - On PowerPC and S/390 targets, it is now possible to use a single
4452 gdbserver executable to debug both 32-bit and 64-bit programs.
4453 (This requires gdbserver itself to be built as a 64-bit executable.)
4455 - gdbserver uses the new noack protocol mode for TCP connections to
4456 reduce communications latency, if also supported and enabled in GDB.
4458 - Support for the sparc64-linux-gnu target is now included in
4461 - The amd64-linux build of gdbserver now supports debugging both
4462 32-bit and 64-bit programs.
4464 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4465 now support hardware watchpoints, and will use them automatically
4470 GDB now has support for scripting using Python. Whether this is
4471 available is determined at configure time.
4473 New GDB commands can now be written in Python.
4475 * Ada tasking support
4477 Ada tasks can now be inspected in GDB. The following commands have
4481 Print the list of Ada tasks.
4483 Print detailed information about task number N.
4485 Print the task number of the current task.
4487 Switch the context of debugging to task number N.
4489 * Support for user-defined prefixed commands. The "define" command can
4490 add new commands to existing prefixes, e.g. "target".
4492 * Multi-inferior, multi-process debugging.
4494 GDB now has generalized support for multi-inferior debugging. See
4495 "Debugging Multiple Inferiors" in the manual for more information.
4496 Although availability still depends on target support, the command
4497 set is more uniform now. The GNU/Linux specific multi-forks support
4498 has been migrated to this new framework. This implied some user
4499 visible changes; see "New commands" and also "Removed commands"
4502 * Target descriptions can now describe the target OS ABI. See the
4503 "Target Description Format" section in the user manual for more
4506 * Target descriptions can now describe "compatible" architectures
4507 to indicate that the target can execute applications for a different
4508 architecture in addition to those for the main target architecture.
4509 See the "Target Description Format" section in the user manual for
4512 * Multi-architecture debugging.
4514 GDB now includes general supports for debugging applications on
4515 hybrid systems that use more than one single processor architecture
4516 at the same time. Each such hybrid architecture still requires
4517 specific support to be added. The only hybrid architecture supported
4518 in this version of GDB is the Cell Broadband Engine.
4520 * GDB now supports integrated debugging of Cell/B.E. applications that
4521 use both the PPU and SPU architectures. To enable support for hybrid
4522 Cell/B.E. debugging, you need to configure GDB to support both the
4523 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4524 --enable-targets configure option.
4526 * Non-stop mode debugging.
4528 For some targets, GDB now supports an optional mode of operation in
4529 which you can examine stopped threads while other threads continue
4530 to execute freely. This is referred to as non-stop mode, with the
4531 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4532 section in the user manual for more information.
4534 To be able to support remote non-stop debugging, a remote stub needs
4535 to implement the non-stop mode remote protocol extensions, as
4536 described in the "Remote Non-Stop" section of the user manual. The
4537 GDB remote stub, gdbserver, has been adjusted to support these
4538 extensions on linux targets.
4540 * New commands (for set/show, see "New options" below)
4542 catch syscall [NAME(S) | NUMBER(S)]
4543 Catch system calls. Arguments, which should be names of system
4544 calls or their numbers, mean catch only those syscalls. Without
4545 arguments, every syscall will be caught. When the inferior issues
4546 any of the specified syscalls, GDB will stop and announce the system
4547 call, both when it is called and when its call returns. This
4548 feature is currently available with a native GDB running on the
4549 Linux Kernel, under the following architectures: x86, x86_64,
4550 PowerPC and PowerPC64.
4552 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4554 Search memory for a sequence of bytes.
4556 maint set python print-stack
4557 maint show python print-stack
4558 Show a stack trace when an error is encountered in a Python script.
4561 Invoke CODE by passing it to the Python interpreter.
4566 These allow macros to be defined, undefined, and listed
4570 Show operating system information about processes.
4573 List the inferiors currently under GDB's control.
4576 Switch focus to inferior number NUM.
4579 Detach from inferior number NUM.
4582 Kill inferior number NUM.
4586 set spu stop-on-load
4587 show spu stop-on-load
4588 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4590 set spu auto-flush-cache
4591 show spu auto-flush-cache
4592 Control whether to automatically flush the software-managed cache
4593 during Cell/B.E. debugging.
4595 set sh calling-convention
4596 show sh calling-convention
4597 Control the calling convention used when calling SH target functions.
4600 show debug timestamp
4601 Control display of timestamps with GDB debugging output.
4603 set disassemble-next-line
4604 show disassemble-next-line
4605 Control display of disassembled source lines or instructions when
4608 set remote noack-packet
4609 show remote noack-packet
4610 Set/show the use of remote protocol QStartNoAckMode packet. See above
4611 under "New remote packets."
4613 set remote query-attached-packet
4614 show remote query-attached-packet
4615 Control use of remote protocol `qAttached' (query-attached) packet.
4617 set remote read-siginfo-object
4618 show remote read-siginfo-object
4619 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4622 set remote write-siginfo-object
4623 show remote write-siginfo-object
4624 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4627 set remote reverse-continue
4628 show remote reverse-continue
4629 Control use of remote protocol 'bc' (reverse-continue) packet.
4631 set remote reverse-step
4632 show remote reverse-step
4633 Control use of remote protocol 'bs' (reverse-step) packet.
4635 set displaced-stepping
4636 show displaced-stepping
4637 Control displaced stepping mode. Displaced stepping is a way to
4638 single-step over breakpoints without removing them from the debuggee.
4639 Also known as "out-of-line single-stepping".
4642 show debug displaced
4643 Control display of debugging info for displaced stepping.
4645 maint set internal-error
4646 maint show internal-error
4647 Control what GDB does when an internal error is detected.
4649 maint set internal-warning
4650 maint show internal-warning
4651 Control what GDB does when an internal warning is detected.
4656 Use a wrapper program to launch programs for debugging.
4658 set multiple-symbols (all|ask|cancel)
4659 show multiple-symbols
4660 The value of this variable can be changed to adjust the debugger behavior
4661 when an expression or a breakpoint location contains an ambiguous symbol
4662 name (an overloaded function name, for instance).
4664 set breakpoint always-inserted
4665 show breakpoint always-inserted
4666 Keep breakpoints always inserted in the target, as opposed to inserting
4667 them when resuming the target, and removing them when the target stops.
4668 This option can improve debugger performance on slow remote targets.
4670 set arm fallback-mode (arm|thumb|auto)
4671 show arm fallback-mode
4672 set arm force-mode (arm|thumb|auto)
4674 These commands control how ARM GDB determines whether instructions
4675 are ARM or Thumb. The default for both settings is auto, which uses
4676 the current CPSR value for instructions without symbols; previous
4677 versions of GDB behaved as if "set arm fallback-mode arm".
4679 set disable-randomization
4680 show disable-randomization
4681 Standalone programs run with the virtual address space randomization enabled
4682 by default on some platforms. This option keeps the addresses stable across
4683 multiple debugging sessions.
4687 Control whether other threads are stopped or not when some thread hits
4692 Requests that asynchronous execution is enabled in the target, if available.
4693 In this case, it's possible to resume target in the background, and interact
4694 with GDB while the target is running. "show target-async" displays the
4695 current state of asynchronous execution of the target.
4697 set target-wide-charset
4698 show target-wide-charset
4699 The target-wide-charset is the name of the character set that GDB
4700 uses when printing characters whose type is wchar_t.
4702 set tcp auto-retry (on|off)
4704 set tcp connect-timeout
4705 show tcp connect-timeout
4706 These commands allow GDB to retry failed TCP connections to a remote stub
4707 with a specified timeout period; this is useful if the stub is launched
4708 in parallel with GDB but may not be ready to accept connections immediately.
4710 set libthread-db-search-path
4711 show libthread-db-search-path
4712 Control list of directories which GDB will search for appropriate
4715 set schedule-multiple (on|off)
4716 show schedule-multiple
4717 Allow GDB to resume all threads of all processes or only threads of
4718 the current process.
4722 Use more aggressive caching for accesses to the stack. This improves
4723 performance of remote debugging (particularly backtraces) without
4724 affecting correctness.
4726 set interactive-mode (on|off|auto)
4727 show interactive-mode
4728 Control whether GDB runs in interactive mode (on) or not (off).
4729 When in interactive mode, GDB waits for the user to answer all
4730 queries. Otherwise, GDB does not wait and assumes the default
4731 answer. When set to auto (the default), GDB determines which
4732 mode to use based on the stdin settings.
4737 For program forks, this is replaced by the new more generic `info
4738 inferiors' command. To list checkpoints, you can still use the
4739 `info checkpoints' command, which was an alias for the `info forks'
4743 Replaced by the new `inferior' command. To switch between
4744 checkpoints, you can still use the `restart' command, which was an
4745 alias for the `fork' command.
4748 This is removed, since some targets don't have a notion of
4749 processes. To switch between processes, you can still use the
4750 `inferior' command using GDB's own inferior number.
4753 For program forks, this is replaced by the new more generic `kill
4754 inferior' command. To delete a checkpoint, you can still use the
4755 `delete checkpoint' command, which was an alias for the `delete
4759 For program forks, this is replaced by the new more generic `detach
4760 inferior' command. To detach a checkpoint, you can still use the
4761 `detach checkpoint' command, which was an alias for the `detach
4764 * New native configurations
4766 x86/x86_64 Darwin i[34567]86-*-darwin*
4768 x86_64 MinGW x86_64-*-mingw*
4772 Lattice Mico32 lm32-*
4773 x86 DICOS i[34567]86-*-dicos*
4774 x86_64 DICOS x86_64-*-dicos*
4777 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4778 (mingw32ce) debugging.
4784 These commands were actually not implemented on any target.
4786 *** Changes in GDB 6.8
4788 * New native configurations
4790 NetBSD/hppa hppa*-*netbsd*
4791 Xtensa GNU/Linux xtensa*-*-linux*
4795 NetBSD/hppa hppa*-*-netbsd*
4796 Xtensa GNU/Linux xtensa*-*-linux*
4798 * Change in command line behavior -- corefiles vs. process ids.
4800 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4801 attaching to process NUMBER fails, GDB no longer attempts to open a
4802 core file named NUMBER. Attaching to a program using the -c option
4803 is no longer supported. Instead, use the '-p' or '--pid' options.
4805 * GDB can now be built as a native debugger for debugging Windows x86
4806 (mingw32) Portable Executable (PE) programs.
4808 * Pending breakpoints no longer change their number when their address
4811 * GDB now supports breakpoints with multiple locations,
4812 including breakpoints on C++ constructors, inside C++ templates,
4813 and in inlined functions.
4815 * GDB's ability to debug optimized code has been improved. GDB more
4816 accurately identifies function bodies and lexical blocks that occupy
4817 more than one contiguous range of addresses.
4819 * Target descriptions can now describe registers for PowerPC.
4821 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4822 registers on PowerPC targets.
4824 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4825 targets even when the libthread_db library is not available.
4827 * The GDB remote stub, gdbserver, now supports the new file transfer
4828 commands (remote put, remote get, and remote delete).
4830 * The GDB remote stub, gdbserver, now supports run and attach in
4831 extended-remote mode.
4833 * hppa*64*-*-hpux11* target broken
4834 The debugger is unable to start a program and fails with the following
4835 error: "Error trying to get information about dynamic linker".
4836 The gdb-6.7 release is also affected.
4838 * GDB now supports the --enable-targets= configure option to allow
4839 building a single GDB executable that supports multiple remote
4840 target architectures.
4842 * GDB now supports debugging C and C++ programs which use the
4843 Decimal Floating Point extension. In addition, the PowerPC target
4844 now has a set of pseudo-registers to inspect decimal float values
4845 stored in two consecutive float registers.
4847 * The -break-insert MI command can optionally create pending
4850 * Improved support for debugging Ada
4851 Many improvements to the Ada language support have been made. These
4853 - Better support for Ada2005 interface types
4854 - Improved handling of arrays and slices in general
4855 - Better support for Taft-amendment types
4856 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4858 - Improved command completion in Ada
4861 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4866 set print frame-arguments (all|scalars|none)
4867 show print frame-arguments
4868 The value of this variable can be changed to control which argument
4869 values should be printed by the debugger when displaying a frame.
4874 Transfer files to and from a remote target, and delete remote files.
4881 Transfer files to and from a remote target, and delete remote files.
4883 * New remote packets
4890 Open, close, read, write, and delete files on the remote system.
4893 Attach to an existing process on the remote system, in extended-remote
4897 Run a new process on the remote system, in extended-remote mode.
4899 *** Changes in GDB 6.7
4901 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4902 bfd, libiberty and opcodes, as revealed by static analysis donated by
4903 Coverity, Inc. (http://scan.coverity.com).
4905 * When looking up multiply-defined global symbols, GDB will now prefer the
4906 symbol definition in the current shared library if it was built using the
4907 -Bsymbolic linker option.
4909 * When the Text User Interface (TUI) is not configured, GDB will now
4910 recognize the -tui command-line option and print a message that the TUI
4913 * The GDB remote stub, gdbserver, now has lower overhead for high
4914 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4916 * GDB for MIPS targets now autodetects whether a remote target provides
4917 32-bit or 64-bit register values.
4919 * Support for C++ member pointers has been improved.
4921 * GDB now understands XML target descriptions, which specify the
4922 target's overall architecture. GDB can read a description from
4923 a local file or over the remote serial protocol.
4925 * Vectors of single-byte data use a new integer type which is not
4926 automatically displayed as character or string data.
4928 * The /s format now works with the print command. It displays
4929 arrays of single-byte integers and pointers to single-byte integers
4932 * Target descriptions can now describe target-specific registers,
4933 for architectures which have implemented the support (currently
4934 only ARM, M68K, and MIPS).
4936 * GDB and the GDB remote stub, gdbserver, now support the XScale
4939 * The GDB remote stub, gdbserver, has been updated to support
4940 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4941 has been rewritten to use the standard GDB remote protocol.
4943 * GDB can now step into C++ functions which are called through thunks.
4945 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4947 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4948 layout. It also supports a TextSeg= and DataSeg= response when only
4949 segment base addresses (rather than offsets) are available.
4951 * The /i format now outputs any trailing branch delay slot instructions
4952 immediately following the last instruction within the count specified.
4954 * The GDB remote protocol "T" stop reply packet now supports a
4955 "library" response. Combined with the new "qXfer:libraries:read"
4956 packet, this response allows GDB to debug shared libraries on targets
4957 where the operating system manages the list of loaded libraries (e.g.
4958 Windows and SymbianOS).
4960 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4961 (DLLs) on Windows and Windows CE targets.
4963 * GDB now supports a faster verification that a .debug file matches its binary
4964 according to its build-id signature, if the signature is present.
4970 Enable or disable hardware flow control (RTS/CTS) on the serial port
4971 when debugging using remote targets.
4973 set mem inaccessible-by-default
4974 show mem inaccessible-by-default
4975 If the target supplies a memory map, for instance via the remote
4976 protocol's "qXfer:memory-map:read" packet, setting this variable
4977 prevents GDB from accessing memory outside the memory map. This
4978 is useful for targets with memory mapped registers or which react
4979 badly to accesses of unmapped address space.
4981 set breakpoint auto-hw
4982 show breakpoint auto-hw
4983 If the target supplies a memory map, for instance via the remote
4984 protocol's "qXfer:memory-map:read" packet, setting this variable
4985 lets GDB use hardware breakpoints automatically for memory regions
4986 where it can not use software breakpoints. This covers both the
4987 "break" command and internal breakpoints used for other commands
4988 including "next" and "finish".
4991 catch exception unhandled
4992 Stop the program execution when Ada exceptions are raised.
4995 Stop the program execution when an Ada assertion failed.
4999 Set an alternate system root for target files. This is a more
5000 general version of "set solib-absolute-prefix", which is now
5001 an alias to "set sysroot".
5004 Provide extended SPU facility status information. This set of
5005 commands is available only when debugging the Cell/B.E. SPU
5008 * New native configurations
5010 OpenBSD/sh sh*-*openbsd*
5013 unset tdesc filename
5015 Use the specified local file as an XML target description, and do
5016 not query the target for its built-in description.
5020 OpenBSD/sh sh*-*-openbsd*
5021 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5022 Toshiba Media Processor mep-elf
5024 * New remote packets
5027 Ignore the specified signals; pass them directly to the debugged program
5028 without stopping other threads or reporting them to GDB.
5030 qXfer:features:read:
5031 Read an XML target description from the target, which describes its
5036 Read or write contents of an spufs file on the target system. These
5037 packets are available only on the Cell/B.E. SPU architecture.
5039 qXfer:libraries:read:
5040 Report the loaded shared libraries. Combined with new "T" packet
5041 response, this packet allows GDB to debug shared libraries on
5042 targets where the operating system manages the list of loaded
5043 libraries (e.g. Windows and SymbianOS).
5047 Support for these obsolete configurations has been removed.
5055 i[34567]86-*-lynxos*
5056 i[34567]86-*-netware*
5057 i[34567]86-*-sco3.2v5*
5058 i[34567]86-*-sco3.2v4*
5060 i[34567]86-*-sysv4.2*
5063 i[34567]86-*-unixware2*
5064 i[34567]86-*-unixware*
5073 * Other removed features
5080 Various m68k-only ROM monitors.
5087 Various Renesas ROM monitors and debugging interfaces for SH and
5092 Support for a Macraigor serial interface to on-chip debugging.
5093 GDB does not directly support the newer parallel or USB
5098 A debug information format. The predecessor to DWARF 2 and
5099 DWARF 3, which are still supported.
5101 Support for the HP aCC compiler on HP-UX/PA-RISC
5103 SOM-encapsulated symbolic debugging information, automatic
5104 invocation of pxdb, and the aCC custom C++ ABI. This does not
5105 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5106 with aCC can still be debugged on an assembly level.
5108 MIPS ".pdr" sections
5110 A MIPS-specific format used to describe stack frame layout
5111 in debugging information.
5115 GDB could work with an older version of Guile to debug
5116 the interpreter and Scheme programs running in it.
5118 set mips stack-arg-size
5119 set mips saved-gpreg-size
5121 Use "set mips abi" to control parameter passing for MIPS.
5123 *** Changes in GDB 6.6
5128 Cell Broadband Engine SPU spu-elf
5130 * GDB can now be configured as a cross-debugger targeting native Windows
5131 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5132 running on a Windows system over TCP/IP to debug Windows programs.
5134 * The GDB remote stub, gdbserver, has been updated to support Windows and
5135 Cygwin debugging. Both single-threaded and multi-threaded programs are
5138 * The "set trust-readonly-sections" command works again. This command was
5139 broken in GDB 6.3, 6.4, and 6.5.
5141 * The "load" command now supports writing to flash memory, if the remote
5142 stub provides the required support.
5144 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5145 longer requires symbolic debug information (e.g. DWARF-2).
5150 unset substitute-path
5151 show substitute-path
5152 Manage a list of substitution rules that GDB uses to rewrite the name
5153 of the directories where the sources are located. This can be useful
5154 for instance when the sources were moved to a different location
5155 between compilation and debugging.
5159 Print each CLI command as it is executed. Each command is prefixed with
5160 a number of `+' symbols representing the nesting depth.
5161 The source command now has a `-v' option to enable the same feature.
5165 The ARM Demon monitor support (RDP protocol, "target rdp").
5167 Kernel Object Display, an embedded debugging feature which only worked with
5168 an obsolete version of Cisco IOS.
5170 The 'set download-write-size' and 'show download-write-size' commands.
5172 * New remote packets
5175 Tell a stub about GDB client features, and request remote target features.
5176 The first feature implemented is PacketSize, which allows the target to
5177 specify the size of packets it can handle - to minimize the number of
5178 packets required and improve performance when connected to a remote
5182 Fetch an OS auxilliary vector from the remote stub. This packet is a
5183 more efficient replacement for qPart:auxv:read.
5185 qXfer:memory-map:read:
5186 Fetch a memory map from the remote stub, including information about
5187 RAM, ROM, and flash memory devices.
5192 Erase and program a flash memory device.
5194 * Removed remote packets
5197 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5198 used it, and only gdbserver implemented it.
5200 *** Changes in GDB 6.5
5204 Renesas M32C/M16C m32c-elf
5206 Morpho Technologies ms1 ms1-elf
5210 init-if-undefined Initialize a convenience variable, but
5211 only if it doesn't already have a value.
5213 The following commands are presently only implemented for native GNU/Linux:
5215 checkpoint Save a snapshot of the program state.
5217 restart <n> Return the program state to a
5218 previously saved state.
5220 info checkpoints List currently saved checkpoints.
5222 delete-checkpoint <n> Delete a previously saved checkpoint.
5224 set|show detach-on-fork Tell gdb whether to detach from a newly
5225 forked process, or to keep debugging it.
5227 info forks List forks of the user program that
5228 are available to be debugged.
5230 fork <n> Switch to debugging one of several
5231 forks of the user program that are
5232 available to be debugged.
5234 delete-fork <n> Delete a fork from the list of forks
5235 that are available to be debugged (and
5236 kill the forked process).
5238 detach-fork <n> Delete a fork from the list of forks
5239 that are available to be debugged (and
5240 allow the process to continue).
5244 Morpho Technologies ms2 ms1-elf
5246 * Improved Windows host support
5248 GDB now builds as a cross debugger hosted on i686-mingw32, including
5249 native console support, and remote communications using either
5250 network sockets or serial ports.
5252 * Improved Modula-2 language support
5254 GDB can now print most types in the Modula-2 syntax. This includes:
5255 basic types, set types, record types, enumerated types, range types,
5256 pointer types and ARRAY types. Procedure var parameters are correctly
5257 printed and hexadecimal addresses and character constants are also
5258 written in the Modula-2 syntax. Best results can be obtained by using
5259 GNU Modula-2 together with the -gdwarf-2 command line option.
5263 The ARM rdi-share module.
5265 The Netware NLM debug server.
5267 *** Changes in GDB 6.4
5269 * New native configurations
5271 OpenBSD/arm arm*-*-openbsd*
5272 OpenBSD/mips64 mips64-*-openbsd*
5276 Morpho Technologies ms1 ms1-elf
5278 * New command line options
5280 --batch-silent As for --batch, but totally silent.
5281 --return-child-result The debugger will exist with the same value
5282 the child (debugged) program exited with.
5283 --eval-command COMMAND, -ex COMMAND
5284 Execute a single GDB CLI command. This may be
5285 specified multiple times and in conjunction
5286 with the --command (-x) option.
5288 * Deprecated commands removed
5290 The following commands, that were deprecated in 2000, have been
5294 set|show arm disassembly-flavor set|show arm disassembler
5295 othernames set arm disassembler
5296 set|show remotedebug set|show debug remote
5297 set|show archdebug set|show debug arch
5298 set|show eventdebug set|show debug event
5301 * New BSD user-level threads support
5303 It is now possible to debug programs using the user-level threads
5304 library on OpenBSD and FreeBSD. Currently supported (target)
5307 FreeBSD/amd64 x86_64-*-freebsd*
5308 FreeBSD/i386 i386-*-freebsd*
5309 OpenBSD/i386 i386-*-openbsd*
5311 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5312 are not yet supported.
5314 * New support for Matsushita MN10300 w/sim added
5315 (Work in progress). mn10300-elf.
5317 * REMOVED configurations and files
5319 VxWorks and the XDR protocol *-*-vxworks
5320 Motorola MCORE mcore-*-*
5321 National Semiconductor NS32000 ns32k-*-*
5323 * New "set print array-indexes" command
5325 After turning this setting "on", GDB prints the index of each element
5326 when displaying arrays. The default is "off" to preserve the previous
5329 * VAX floating point support
5331 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5333 * User-defined command support
5335 In addition to using $arg0..$arg9 for argument passing, it is now possible
5336 to use $argc to determine now many arguments have been passed. See the
5337 section on user-defined commands in the user manual for more information.
5339 *** Changes in GDB 6.3:
5341 * New command line option
5343 GDB now accepts -l followed by a number to set the timeout for remote
5346 * GDB works with GCC -feliminate-dwarf2-dups
5348 GDB now supports a more compact representation of DWARF-2 debug
5349 information using DW_FORM_ref_addr references. These are produced
5350 by GCC with the option -feliminate-dwarf2-dups and also by some
5351 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5352 to use -feliminate-dwarf2-dups.
5354 * Internationalization
5356 When supported by the host system, GDB will be built with
5357 internationalization (libintl). The task of marking up the sources is
5358 continued, we're looking forward to our first translation.
5362 Initial support for debugging programs compiled with the GNAT
5363 implementation of the Ada programming language has been integrated
5364 into GDB. In this release, support is limited to expression evaluation.
5366 * New native configurations
5368 GNU/Linux/m32r m32r-*-linux-gnu
5372 GDB's remote protocol now includes support for the 'p' packet. This
5373 packet is used to fetch individual registers from a remote inferior.
5375 * END-OF-LIFE registers[] compatibility module
5377 GDB's internal register infrastructure has been completely rewritten.
5378 The new infrastructure making possible the implementation of key new
5379 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5382 GDB 6.3 will be the last release to include the registers[]
5383 compatibility module that allowed out-of-date configurations to
5384 continue to work. This change directly impacts the following
5394 powerpc bdm protocol
5396 Unless there is activity to revive these configurations, they will be
5397 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5399 * OBSOLETE configurations and files
5401 Configurations that have been declared obsolete in this release have
5402 been commented out. Unless there is activity to revive these
5403 configurations, the next release of GDB will have their sources
5404 permanently REMOVED.
5413 *** Changes in GDB 6.2.1:
5415 * MIPS `break main; run' gave an heuristic-fence-post warning
5417 When attempting to run even a simple program, a warning about
5418 heuristic-fence-post being hit would be reported. This problem has
5421 * MIPS IRIX 'long double' crashed GDB
5423 When examining a long double variable, GDB would get a segmentation
5424 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5425 IRIX long double values).
5429 A bug in the VAX stack code was causing problems with the "next"
5430 command. This problem has been fixed.
5432 *** Changes in GDB 6.2:
5434 * Fix for ``many threads''
5436 On GNU/Linux systems that use the NPTL threads library, a program
5437 rapidly creating and deleting threads would confuse GDB leading to the
5440 ptrace: No such process.
5441 thread_db_get_info: cannot get thread info: generic error
5443 This problem has been fixed.
5445 * "-async" and "-noasync" options removed.
5447 Support for the broken "-noasync" option has been removed (it caused
5450 * New ``start'' command.
5452 This command runs the program until the beginning of the main procedure.
5454 * New BSD Kernel Data Access Library (libkvm) interface
5456 Using ``target kvm'' it is now possible to debug kernel core dumps and
5457 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5458 platforms. Currently supported (native-only) configurations are:
5460 FreeBSD/amd64 x86_64-*-freebsd*
5461 FreeBSD/i386 i?86-*-freebsd*
5462 NetBSD/i386 i?86-*-netbsd*
5463 NetBSD/m68k m68*-*-netbsd*
5464 NetBSD/sparc sparc-*-netbsd*
5465 OpenBSD/amd64 x86_64-*-openbsd*
5466 OpenBSD/i386 i?86-*-openbsd*
5467 OpenBSD/m68k m68*-openbsd*
5468 OpenBSD/sparc sparc-*-openbsd*
5470 * Signal trampoline code overhauled
5472 Many generic problems with GDB's signal handling code have been fixed.
5473 These include: backtraces through non-contiguous stacks; recognition
5474 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5475 call; backtrace through a signal trampoline; step into and out of
5476 signal handlers; and single-stepping in the signal trampoline.
5478 Please note that kernel bugs are a limiting factor here. These
5479 features have been shown to work on an s390 GNU/Linux system that
5480 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5482 * Cygwin support for DWARF 2 added.
5484 * New native configurations
5486 GNU/Linux/hppa hppa*-*-linux*
5487 OpenBSD/hppa hppa*-*-openbsd*
5488 OpenBSD/m68k m68*-*-openbsd*
5489 OpenBSD/m88k m88*-*-openbsd*
5490 OpenBSD/powerpc powerpc-*-openbsd*
5491 NetBSD/vax vax-*-netbsd*
5492 OpenBSD/vax vax-*-openbsd*
5494 * END-OF-LIFE frame compatibility module
5496 GDB's internal frame infrastructure has been completely rewritten.
5497 The new infrastructure making it possible to support key new features
5498 including DWARF 2 Call Frame Information. To aid in the task of
5499 migrating old configurations to this new infrastructure, a
5500 compatibility module, that allowed old configurations to continue to
5501 work, was also included.
5503 GDB 6.2 will be the last release to include this frame compatibility
5504 module. This change directly impacts the following configurations:
5514 Unless there is activity to revive these configurations, they will be
5515 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5517 * REMOVED configurations and files
5519 Sun 3, running SunOS 3 m68*-*-sunos3*
5520 Sun 3, running SunOS 4 m68*-*-sunos4*
5521 Sun 2, running SunOS 3 m68000-*-sunos3*
5522 Sun 2, running SunOS 4 m68000-*-sunos4*
5523 Motorola 680x0 running LynxOS m68*-*-lynxos*
5524 AT&T 3b1/Unix pc m68*-att-*
5525 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5526 decstation mips-dec-* mips-little-*
5527 riscos mips-*-riscos* mips-*-sysv*
5528 sonymips mips-sony-*
5529 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5531 *** Changes in GDB 6.1.1:
5533 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5535 The TUI (Text-mode User Interface) is now built as part of a default
5536 GDB configuration. It is enabled by either selecting the TUI with the
5537 command line option "-i=tui" or by running the separate "gdbtui"
5538 program. For more information on the TUI, see the manual "Debugging
5541 * Pending breakpoint support (also included in GDB 6.1)
5543 Support has been added to allow you to specify breakpoints in shared
5544 libraries that have not yet been loaded. If a breakpoint location
5545 cannot be found, and the "breakpoint pending" option is set to auto,
5546 GDB queries you if you wish to make the breakpoint pending on a future
5547 shared-library load. If and when GDB resolves the breakpoint symbol,
5548 the pending breakpoint is removed as one or more regular breakpoints
5551 Pending breakpoints are very useful for GCJ Java debugging.
5553 * Fixed ISO-C build problems
5555 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5556 non ISO-C code that stopped them being built using a more strict ISO-C
5557 compiler (e.g., IBM's C compiler).
5559 * Fixed build problem on IRIX 5
5561 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5562 wasn't able to compile compile on an IRIX 5 system.
5564 * Added execute permission to gdb/gdbserver/configure
5566 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5567 permission. This bug would cause configure to fail on a number of
5568 systems (Solaris, IRIX). Ref: server/519.
5570 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5572 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5573 has been updated to use constant array sizes.
5575 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5577 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5578 its generated DWARF Call Frame Info. This encoding was causing GDB to
5579 panic, that panic has been fixed. Ref: gdb/1628.
5581 * Fixed a problem when examining parameters in shared library code.
5583 When examining parameters in optimized shared library code generated
5584 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5585 not available''. GDB now correctly displays the variable's value.
5587 *** Changes in GDB 6.1:
5589 * Removed --with-mmalloc
5591 Support for the mmalloc memory manager has been removed, as it
5592 conflicted with the internal gdb byte cache.
5594 * Changes in AMD64 configurations
5596 The AMD64 target now includes the %cs and %ss registers. As a result
5597 the AMD64 remote protocol has changed; this affects the floating-point
5598 and SSE registers. If you rely on those registers for your debugging,
5599 you should upgrade gdbserver on the remote side.
5601 * Revised SPARC target
5603 The SPARC target has been completely revised, incorporating the
5604 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5605 support for LynxOS and SunOS 4 has been dropped. Calling functions
5606 from within GDB on operating systems with a non-executable stack
5607 (Solaris, OpenBSD) now works.
5611 GDB has a new C++ demangler which does a better job on the mangled
5612 names generated by current versions of g++. It also runs faster, so
5613 with this and other changes gdb should now start faster on large C++
5616 * DWARF 2 Location Expressions
5618 GDB support for location expressions has been extended to support function
5619 arguments and frame bases. Older versions of GDB could crash when they
5622 * C++ nested types and namespaces
5624 GDB's support for nested types and namespaces in C++ has been
5625 improved, especially if you use the DWARF 2 debugging format. (This
5626 is the default for recent versions of GCC on most platforms.)
5627 Specifically, if you have a class "Inner" defined within a class or
5628 namespace "Outer", then GDB realizes that the class's name is
5629 "Outer::Inner", not simply "Inner". This should greatly reduce the
5630 frequency of complaints about not finding RTTI symbols. In addition,
5631 if you are stopped at inside of a function defined within a namespace,
5632 GDB modifies its name lookup accordingly.
5634 * New native configurations
5636 NetBSD/amd64 x86_64-*-netbsd*
5637 OpenBSD/amd64 x86_64-*-openbsd*
5638 OpenBSD/alpha alpha*-*-openbsd*
5639 OpenBSD/sparc sparc-*-openbsd*
5640 OpenBSD/sparc64 sparc64-*-openbsd*
5642 * New debugging protocols
5644 M32R with SDI protocol m32r-*-elf*
5646 * "set prompt-escape-char" command deleted.
5648 The command "set prompt-escape-char" has been deleted. This command,
5649 and its very obscure effect on GDB's prompt, was never documented,
5650 tested, nor mentioned in the NEWS file.
5652 * OBSOLETE configurations and files
5654 Configurations that have been declared obsolete in this release have
5655 been commented out. Unless there is activity to revive these
5656 configurations, the next release of GDB will have their sources
5657 permanently REMOVED.
5659 Sun 3, running SunOS 3 m68*-*-sunos3*
5660 Sun 3, running SunOS 4 m68*-*-sunos4*
5661 Sun 2, running SunOS 3 m68000-*-sunos3*
5662 Sun 2, running SunOS 4 m68000-*-sunos4*
5663 Motorola 680x0 running LynxOS m68*-*-lynxos*
5664 AT&T 3b1/Unix pc m68*-att-*
5665 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5666 decstation mips-dec-* mips-little-*
5667 riscos mips-*-riscos* mips-*-sysv*
5668 sonymips mips-sony-*
5669 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5671 * REMOVED configurations and files
5673 SGI Irix-4.x mips-sgi-irix4 or iris4
5674 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5675 Z8000 simulator z8k-zilog-none or z8ksim
5676 Matsushita MN10200 w/simulator mn10200-*-*
5677 H8/500 simulator h8500-hitachi-hms or h8500hms
5678 HP/PA running BSD hppa*-*-bsd*
5679 HP/PA running OSF/1 hppa*-*-osf*
5680 HP/PA Pro target hppa*-*-pro*
5681 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5682 386BSD i[3456]86-*-bsd*
5683 Sequent family i[3456]86-sequent-sysv4*
5684 i[3456]86-sequent-sysv*
5685 i[3456]86-sequent-bsd*
5686 SPARC running LynxOS sparc-*-lynxos*
5687 SPARC running SunOS 4 sparc-*-sunos4*
5688 Tsqware Sparclet sparclet-*-*
5689 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5691 *** Changes in GDB 6.0:
5695 Support for debugging the Objective-C programming language has been
5696 integrated into GDB.
5698 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5700 DWARF 2's Call Frame Information makes available compiler generated
5701 information that more exactly describes the program's run-time stack.
5702 By using this information, GDB is able to provide more robust stack
5705 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5706 have been updated to use a new backtrace mechanism which includes
5707 DWARF 2 CFI support.
5711 GDB's remote protocol has been extended to include support for hosted
5712 file I/O (where the remote target uses GDB's file system). See GDB's
5713 remote protocol documentation for details.
5715 * All targets using the new architecture framework.
5717 All of GDB's targets have been updated to use the new internal
5718 architecture framework. The way is now open for future GDB releases
5719 to include cross-architecture native debugging support (i386 on amd64,
5722 * GNU/Linux's Thread Local Storage (TLS)
5724 GDB now includes support for for the GNU/Linux implementation of
5725 per-thread variables.
5727 * GNU/Linux's Native POSIX Thread Library (NPTL)
5729 GDB's thread code has been updated to work with either the new
5730 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5732 * Separate debug info.
5734 GDB, in conjunction with BINUTILS, now supports a mechanism for
5735 automatically loading debug information from a separate file. Instead
5736 of shipping full debug and non-debug versions of system libraries,
5737 system integrators can now instead ship just the stripped libraries
5738 and optional debug files.
5740 * DWARF 2 Location Expressions
5742 DWARF 2 Location Expressions allow the compiler to more completely
5743 describe the location of variables (even in optimized code) to the
5746 GDB now includes preliminary support for location expressions (support
5747 for DW_OP_piece is still missing).
5751 A number of long standing bugs that caused GDB to die while starting a
5752 Java application have been fixed. GDB's Java support is now
5753 considered "useable".
5755 * GNU/Linux support for fork, vfork, and exec.
5757 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5758 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5761 * GDB supports logging output to a file
5763 There are two new commands, "set logging" and "show logging", which can be
5764 used to capture GDB's output to a file.
5766 * The meaning of "detach" has changed for gdbserver
5768 The "detach" command will now resume the application, as documented. To
5769 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5772 * d10v, m68hc11 `regs' command deprecated
5774 The `info registers' command has been updated so that it displays the
5775 registers using a format identical to the old `regs' command.
5779 A new command, "maint set profile on/off", has been added. This command can
5780 be used to enable or disable profiling while running GDB, to profile a
5781 session or a set of commands. In addition there is a new configure switch,
5782 "--enable-profiling", which will cause GDB to be compiled with profiling
5783 data, for more informative profiling results.
5785 * Default MI syntax changed to "mi2".
5787 The default MI (machine interface) syntax, enabled by the command line
5788 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5789 "mi1", can be enabled by specifying the option "-i=mi1".
5791 Support for the original "mi0" syntax (included in GDB 5.0) has been
5794 Fix for gdb/192: removed extraneous space when displaying frame level.
5795 Fix for gdb/672: update changelist is now output in mi list format.
5796 Fix for gdb/702: a -var-assign that updates the value now shows up
5797 in a subsequent -var-update.
5799 * New native configurations.
5801 FreeBSD/amd64 x86_64-*-freebsd*
5803 * Multi-arched targets.
5805 HP/PA HPUX11 hppa*-*-hpux*
5806 Renesas M32R/D w/simulator m32r-*-elf*
5808 * OBSOLETE configurations and files
5810 Configurations that have been declared obsolete in this release have
5811 been commented out. Unless there is activity to revive these
5812 configurations, the next release of GDB will have their sources
5813 permanently REMOVED.
5815 Z8000 simulator z8k-zilog-none or z8ksim
5816 Matsushita MN10200 w/simulator mn10200-*-*
5817 H8/500 simulator h8500-hitachi-hms or h8500hms
5818 HP/PA running BSD hppa*-*-bsd*
5819 HP/PA running OSF/1 hppa*-*-osf*
5820 HP/PA Pro target hppa*-*-pro*
5821 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5822 Sequent family i[3456]86-sequent-sysv4*
5823 i[3456]86-sequent-sysv*
5824 i[3456]86-sequent-bsd*
5825 Tsqware Sparclet sparclet-*-*
5826 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5828 * REMOVED configurations and files
5831 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5832 IBM AIX PS/2 i[3456]86-*-aix
5833 i386 running Mach 3.0 i[3456]86-*-mach3*
5834 i386 running Mach i[3456]86-*-mach*
5835 i386 running OSF/1 i[3456]86-*osf1mk*
5836 HP/Apollo 68k Family m68*-apollo*-sysv*,
5838 m68*-hp-bsd*, m68*-hp-hpux*
5839 Argonaut Risc Chip (ARC) arc-*-*
5840 Mitsubishi D30V d30v-*-*
5841 Fujitsu FR30 fr30-*-elf*
5842 OS/9000 i[34]86-*-os9k
5843 I960 with MON960 i960-*-coff
5845 * MIPS $fp behavior changed
5847 The convenience variable $fp, for the MIPS, now consistently returns
5848 the address of the current frame's base. Previously, depending on the
5849 context, $fp could refer to either $sp or the current frame's base
5850 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5851 The GNU Source-Level Debugger''.
5853 *** Changes in GDB 5.3:
5855 * GNU/Linux shared library multi-threaded performance improved.
5857 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5858 `/proc', in preference to `ptrace' for memory reads. This may result
5859 in an improvement in the start-up time of multi-threaded, shared
5860 library applications when run under GDB. One GDB user writes: ``loads
5861 shared libs like mad''.
5863 * ``gdbserver'' now supports multi-threaded applications on some targets
5865 Support for debugging multi-threaded applications which use
5866 the GNU/Linux LinuxThreads package has been added for
5867 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5868 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5870 * GDB now supports C/C++ preprocessor macros.
5872 GDB now expands preprocessor macro invocations in C/C++ expressions,
5873 and provides various commands for showing macro definitions and how
5876 The new command `macro expand EXPRESSION' expands any macro
5877 invocations in expression, and shows the result.
5879 The new command `show macro MACRO-NAME' shows the definition of the
5880 macro named MACRO-NAME, and where it was defined.
5882 Most compilers don't include information about macros in the debugging
5883 information by default. In GCC 3.1, for example, you need to compile
5884 your program with the options `-gdwarf-2 -g3'. If the macro
5885 information is present in the executable, GDB will read it.
5887 * Multi-arched targets.
5889 DEC Alpha (partial) alpha*-*-*
5890 DEC VAX (partial) vax-*-*
5892 National Semiconductor NS32000 (partial) ns32k-*-*
5893 Motorola 68000 (partial) m68k-*-*
5894 Motorola MCORE mcore-*-*
5898 Fujitsu FRV architecture added by Red Hat frv*-*-*
5901 * New native configurations
5903 Alpha NetBSD alpha*-*-netbsd*
5904 SH NetBSD sh*-*-netbsdelf*
5905 MIPS NetBSD mips*-*-netbsd*
5906 UltraSPARC NetBSD sparc64-*-netbsd*
5908 * OBSOLETE configurations and files
5910 Configurations that have been declared obsolete in this release have
5911 been commented out. Unless there is activity to revive these
5912 configurations, the next release of GDB will have their sources
5913 permanently REMOVED.
5915 Mitsubishi D30V d30v-*-*
5916 OS/9000 i[34]86-*-os9k
5917 IBM AIX PS/2 i[3456]86-*-aix
5918 Fujitsu FR30 fr30-*-elf*
5919 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5920 Argonaut Risc Chip (ARC) arc-*-*
5921 i386 running Mach 3.0 i[3456]86-*-mach3*
5922 i386 running Mach i[3456]86-*-mach*
5923 i386 running OSF/1 i[3456]86-*osf1mk*
5924 HP/Apollo 68k Family m68*-apollo*-sysv*,
5926 m68*-hp-bsd*, m68*-hp-hpux*
5927 I960 with MON960 i960-*-coff
5929 * OBSOLETE languages
5931 CHILL, a Pascal like language used by telecommunications companies.
5933 * REMOVED configurations and files
5935 AMD 29k family via UDI a29k-amd-udi, udi29k
5936 A29K VxWorks a29k-*-vxworks
5937 AMD 29000 embedded, using EBMON a29k-none-none
5938 AMD 29000 embedded with COFF a29k-none-coff
5939 AMD 29000 embedded with a.out a29k-none-aout
5941 testsuite/gdb.hp/gdb.threads-hp/ directory
5943 * New command "set max-user-call-depth <nnn>"
5945 This command allows the user to limit the call depth of user-defined
5946 commands. The default is 1024.
5948 * Changes in FreeBSD/i386 native debugging.
5950 Support for the "generate-core-file" has been added.
5952 * New commands "dump", "append", and "restore".
5954 These commands allow data to be copied from target memory
5955 to a bfd-format or binary file (dump and append), and back
5956 from a file into memory (restore).
5958 * Improved "next/step" support on multi-processor Alpha Tru64.
5960 The previous single-step mechanism could cause unpredictable problems,
5961 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5962 of a software single-step mechanism prevents this.
5964 *** Changes in GDB 5.2.1:
5972 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5973 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5974 Fix, by Joel Brobecker imported from mainline.
5976 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5977 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5978 Fix, by Fred Fish, imported from mainline.
5980 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5981 Surprisingly enough, it works now.
5982 By Michal Ludvig, imported from mainline.
5984 i386 hardware watchpoint support:
5985 avoid misses on second run for some targets.
5986 By Pierre Muller, imported from mainline.
5988 *** Changes in GDB 5.2:
5990 * New command "set trust-readonly-sections on[off]".
5992 This command is a hint that tells gdb that read-only sections
5993 really are read-only (ie. that their contents will not change).
5994 In this mode, gdb will go to the object file rather than the
5995 target to read memory from read-only sections (such as ".text").
5996 This can be a significant performance improvement on some
5997 (notably embedded) targets.
5999 * New command "generate-core-file" (or "gcore").
6001 This new gdb command allows the user to drop a core file of the child
6002 process state at any time. So far it's been implemented only for
6003 GNU/Linux and Solaris, but should be relatively easily ported to other
6004 hosts. Argument is core file name (defaults to core.<pid>).
6006 * New command line option
6008 GDB now accepts --pid or -p followed by a process id.
6010 * Change in command line behavior -- corefiles vs. process ids.
6012 There is a subtle behavior in the way in which GDB handles
6013 command line arguments. The first non-flag argument is always
6014 a program to debug, but the second non-flag argument may either
6015 be a corefile or a process id. Previously, GDB would attempt to
6016 open the second argument as a corefile, and if that failed, would
6017 issue a superfluous error message and then attempt to attach it as
6018 a process. Now, if the second argument begins with a non-digit,
6019 it will be treated as a corefile. If it begins with a digit,
6020 GDB will attempt to attach it as a process, and if no such process
6021 is found, will then attempt to open it as a corefile.
6023 * Changes in ARM configurations.
6025 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6026 configuration is fully multi-arch.
6028 * New native configurations
6030 ARM NetBSD arm*-*-netbsd*
6031 x86 OpenBSD i[3456]86-*-openbsd*
6032 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6033 Sparc64 running FreeBSD sparc64-*-freebsd*
6037 Sanyo XStormy16 xstormy16-elf
6039 * OBSOLETE configurations and files
6041 Configurations that have been declared obsolete in this release have
6042 been commented out. Unless there is activity to revive these
6043 configurations, the next release of GDB will have their sources
6044 permanently REMOVED.
6046 AMD 29k family via UDI a29k-amd-udi, udi29k
6047 A29K VxWorks a29k-*-vxworks
6048 AMD 29000 embedded, using EBMON a29k-none-none
6049 AMD 29000 embedded with COFF a29k-none-coff
6050 AMD 29000 embedded with a.out a29k-none-aout
6052 testsuite/gdb.hp/gdb.threads-hp/ directory
6054 * REMOVED configurations and files
6056 TI TMS320C80 tic80-*-*
6058 PowerPC Solaris powerpcle-*-solaris*
6059 PowerPC Windows NT powerpcle-*-cygwin32
6060 PowerPC Netware powerpc-*-netware*
6061 Harris/CXUX m88k m88*-harris-cxux*
6062 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6063 ns32k-utek-sysv* ns32k-utek-*
6064 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6065 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6066 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6067 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6068 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6070 * Changes to command line processing
6072 The new `--args' feature can be used to specify command-line arguments
6073 for the inferior from gdb's command line.
6075 * Changes to key bindings
6077 There is a new `operate-and-get-next' function bound to `C-o'.
6079 *** Changes in GDB 5.1.1
6081 Fix compile problem on DJGPP.
6083 Fix a problem with floating-point registers on the i386 being
6086 Fix to stop GDB crashing on .debug_str debug info.
6088 Numerous documentation fixes.
6090 Numerous testsuite fixes.
6092 *** Changes in GDB 5.1:
6094 * New native configurations
6096 Alpha FreeBSD alpha*-*-freebsd*
6097 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6098 MIPS GNU/Linux mips*-*-linux*
6099 MIPS SGI Irix 6.x mips*-sgi-irix6*
6100 ia64 AIX ia64-*-aix*
6101 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6105 Motorola 68HC11 and 68HC12 m68hc11-elf
6107 UltraSparc running GNU/Linux sparc64-*-linux*
6109 * OBSOLETE configurations and files
6111 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6112 Harris/CXUX m88k m88*-harris-cxux*
6113 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6114 ns32k-utek-sysv* ns32k-utek-*
6115 TI TMS320C80 tic80-*-*
6117 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6118 PowerPC Solaris powerpcle-*-solaris*
6119 PowerPC Windows NT powerpcle-*-cygwin32
6120 PowerPC Netware powerpc-*-netware*
6121 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6122 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6123 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6124 Apple Macintosh (MPW) host N/A
6126 stuff.c (Program to stuff files into a specially prepared space in kdb)
6127 kdb-start.c (Main loop for the standalone kernel debugger)
6129 Configurations that have been declared obsolete in this release have
6130 been commented out. Unless there is activity to revive these
6131 configurations, the next release of GDB will have their sources
6132 permanently REMOVED.
6134 * REMOVED configurations and files
6136 Altos 3068 m68*-altos-*
6137 Convex c1-*-*, c2-*-*
6139 ARM RISCix arm-*-* (as host)
6143 * GDB has been converted to ISO C.
6145 GDB's source code has been converted to ISO C. In particular, the
6146 sources are fully protoized, and rely on standard headers being
6151 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6153 * The MI enabled by default.
6155 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6156 revised and enabled by default. Packages which use GDB as a debugging
6157 engine behind a UI or another front end are encouraged to switch to
6158 using the GDB/MI interface, instead of the old annotations interface
6159 which is now deprecated.
6161 * Support for debugging Pascal programs.
6163 GDB now includes support for debugging Pascal programs. The following
6164 main features are supported:
6166 - Pascal-specific data types such as sets;
6168 - automatic recognition of Pascal sources based on file-name
6171 - Pascal-style display of data types, variables, and functions;
6173 - a Pascal expression parser.
6175 However, some important features are not yet supported.
6177 - Pascal string operations are not supported at all;
6179 - there are some problems with boolean types;
6181 - Pascal type hexadecimal constants are not supported
6182 because they conflict with the internal variables format;
6184 - support for Pascal objects and classes is not full yet;
6186 - unlike Pascal, GDB is case-sensitive for symbol names.
6188 * Changes in completion.
6190 Commands such as `shell', `run' and `set args', which pass arguments
6191 to inferior programs, now complete on file names, similar to what
6192 users expect at the shell prompt.
6194 Commands which accept locations, such as `disassemble', `print',
6195 `breakpoint', `until', etc. now complete on filenames as well as
6196 program symbols. Thus, if you type "break foob TAB", and the source
6197 files linked into the programs include `foobar.c', that file name will
6198 be one of the candidates for completion. However, file names are not
6199 considered for completion after you typed a colon that delimits a file
6200 name from a name of a function in that file, as in "break foo.c:bar".
6202 `set demangle-style' completes on available demangling styles.
6204 * New platform-independent commands:
6206 It is now possible to define a post-hook for a command as well as a
6207 hook that runs before the command. For more details, see the
6208 documentation of `hookpost' in the GDB manual.
6210 * Changes in GNU/Linux native debugging.
6212 Support for debugging multi-threaded programs has been completely
6213 revised for all platforms except m68k and sparc. You can now debug as
6214 many threads as your system allows you to have.
6216 Attach/detach is supported for multi-threaded programs.
6218 Support for SSE registers was added for x86. This doesn't work for
6219 multi-threaded programs though.
6221 * Changes in MIPS configurations.
6223 Multi-arch support is enabled for all MIPS configurations.
6225 GDB can now be built as native debugger on SGI Irix 6.x systems for
6226 debugging n32 executables. (Debugging 64-bit executables is not yet
6229 * Unified support for hardware watchpoints in all x86 configurations.
6231 Most (if not all) native x86 configurations support hardware-assisted
6232 breakpoints and watchpoints in a unified manner. This support
6233 implements debug register sharing between watchpoints, which allows to
6234 put a virtually infinite number of watchpoints on the same address,
6235 and also supports watching regions up to 16 bytes with several debug
6238 The new maintenance command `maintenance show-debug-regs' toggles
6239 debugging print-outs in functions that insert, remove, and test
6240 watchpoints and hardware breakpoints.
6242 * Changes in the DJGPP native configuration.
6244 New command ``info dos sysinfo'' displays assorted information about
6245 the CPU, OS, memory, and DPMI server.
6247 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6248 display information about segment descriptors stored in GDT, LDT, and
6251 New commands ``info dos pde'' and ``info dos pte'' display entries
6252 from Page Directory and Page Tables (for now works with CWSDPMI only).
6253 New command ``info dos address-pte'' displays the Page Table entry for
6254 a given linear address.
6256 GDB can now pass command lines longer than 126 characters to the
6257 program being debugged (requires an update to the libdbg.a library
6258 which is part of the DJGPP development kit).
6260 DWARF2 debug info is now supported.
6262 It is now possible to `step' and `next' through calls to `longjmp'.
6264 * Changes in documentation.
6266 All GDB documentation was converted to GFDL, the GNU Free
6267 Documentation License.
6269 Tracepoints-related commands are now fully documented in the GDB
6272 TUI, the Text-mode User Interface, is now documented in the manual.
6274 Tracepoints-related commands are now fully documented in the GDB
6277 The "GDB Internals" manual now has an index. It also includes
6278 documentation of `ui_out' functions, GDB coding standards, x86
6279 hardware watchpoints, and memory region attributes.
6281 * GDB's version number moved to ``version.in''
6283 The Makefile variable VERSION has been replaced by the file
6284 ``version.in''. People creating GDB distributions should update the
6285 contents of this file.
6289 GUD support is now a standard part of the EMACS distribution.
6291 *** Changes in GDB 5.0:
6293 * Improved support for debugging FP programs on x86 targets
6295 Unified and much-improved support for debugging floating-point
6296 programs on all x86 targets. In particular, ``info float'' now
6297 displays the FP registers in the same format on all x86 targets, with
6298 greater level of detail.
6300 * Improvements and bugfixes in hardware-assisted watchpoints
6302 It is now possible to watch array elements, struct members, and
6303 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6304 on x86 targets no longer erroneously trigger when the address is
6307 * Improvements in the native DJGPP version of GDB
6309 The distribution now includes all the scripts and auxiliary files
6310 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6311 machines ``out of the box''.
6313 The DJGPP version can now debug programs that use signals. It is
6314 possible to catch signals that happened in the debuggee, deliver
6315 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6316 would kill the program being debugged.) Programs that hook hardware
6317 interrupts (keyboard, timer, etc.) can also be debugged.
6319 It is now possible to debug DJGPP programs that redirect their
6320 standard handles or switch them to raw (as opposed to cooked) mode, or
6321 even close them. The command ``run < foo > bar'' works as expected,
6322 and ``info terminal'' reports useful information about the debuggee's
6323 terminal, including raw/cooked mode, redirection, etc.
6325 The DJGPP version now uses termios functions for console I/O, which
6326 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6329 DOS-style file names with drive letters are now fully supported by
6332 It is now possible to debug DJGPP programs that switch their working
6333 directory. It is also possible to rerun the debuggee any number of
6334 times without restarting GDB; thus, you can use the same setup,
6335 breakpoints, etc. for many debugging sessions.
6337 * New native configurations
6339 ARM GNU/Linux arm*-*-linux*
6340 PowerPC GNU/Linux powerpc-*-linux*
6344 Motorola MCore mcore-*-*
6345 x86 VxWorks i[3456]86-*-vxworks*
6346 PowerPC VxWorks powerpc-*-vxworks*
6347 TI TMS320C80 tic80-*-*
6349 * OBSOLETE configurations
6351 Altos 3068 m68*-altos-*
6352 Convex c1-*-*, c2-*-*
6354 ARM RISCix arm-*-* (as host)
6357 Configurations that have been declared obsolete will be commented out,
6358 but the code will be left in place. If there is no activity to revive
6359 these configurations before the next release of GDB, the sources will
6360 be permanently REMOVED.
6362 * Gould support removed
6364 Support for the Gould PowerNode and NP1 has been removed.
6366 * New features for SVR4
6368 On SVR4 native platforms (such as Solaris), if you attach to a process
6369 without first loading a symbol file, GDB will now attempt to locate and
6370 load symbols from the running process's executable file.
6372 * Many C++ enhancements
6374 C++ support has been greatly improved. Overload resolution now works properly
6375 in almost all cases. RTTI support is on the way.
6377 * Remote targets can connect to a sub-program
6379 A popen(3) style serial-device has been added. This device starts a
6380 sub-process (such as a stand-alone simulator) and then communicates
6381 with that. The sub-program to run is specified using the syntax
6382 ``|<program> <args>'' vis:
6384 (gdb) set remotedebug 1
6385 (gdb) target extended-remote |mn10300-elf-sim program-args
6387 * MIPS 64 remote protocol
6389 A long standing bug in the mips64 remote protocol where by GDB
6390 expected certain 32 bit registers (ex SR) to be transfered as 32
6391 instead of 64 bits has been fixed.
6393 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6394 added to provide backward compatibility with older versions of GDB.
6396 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6398 The command ``set remotebinarydownload'' command has been replaced by
6399 ``set remote X-packet''. Other commands in ``set remote'' family
6400 include ``set remote P-packet''.
6402 * Breakpoint commands accept ranges.
6404 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6405 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6406 ``tracepoint passcount'' also accepts a range of tracepoints.
6408 * ``apropos'' command added.
6410 The ``apropos'' command searches through command names and
6411 documentation strings, printing out matches, making it much easier to
6412 try to find a command that does what you are looking for.
6416 A new machine oriented interface (MI) has been added to GDB. This
6417 interface is designed for debug environments running GDB as a separate
6418 process. This is part of the long term libGDB project. See the
6419 "GDB/MI" chapter of the GDB manual for further information. It can be
6420 enabled by configuring with:
6422 .../configure --enable-gdbmi
6424 *** Changes in GDB-4.18:
6426 * New native configurations
6428 HP-UX 10.20 hppa*-*-hpux10.20
6429 HP-UX 11.x hppa*-*-hpux11.0*
6430 M68K GNU/Linux m68*-*-linux*
6434 Fujitsu FR30 fr30-*-elf*
6435 Intel StrongARM strongarm-*-*
6436 Mitsubishi D30V d30v-*-*
6438 * OBSOLETE configurations
6440 Gould PowerNode, NP1 np1-*-*, pn-*-*
6442 Configurations that have been declared obsolete will be commented out,
6443 but the code will be left in place. If there is no activity to revive
6444 these configurations before the next release of GDB, the sources will
6445 be permanently REMOVED.
6449 As a compatibility experiment, GDB's source files buildsym.h and
6450 buildsym.c have been converted to pure standard C, no longer
6451 containing any K&R compatibility code. We believe that all systems in
6452 use today either come with a standard C compiler, or have a GCC port
6453 available. If this is not true, please report the affected
6454 configuration to bug-gdb@gnu.org immediately. See the README file for
6455 information about getting a standard C compiler if you don't have one
6460 GDB now uses readline 2.2.
6462 * set extension-language
6464 You can now control the mapping between filename extensions and source
6465 languages by using the `set extension-language' command. For instance,
6466 you can ask GDB to treat .c files as C++ by saying
6467 set extension-language .c c++
6468 The command `info extensions' lists all of the recognized extensions
6469 and their associated languages.
6471 * Setting processor type for PowerPC and RS/6000
6473 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6474 you can use the `set processor' command to specify what variant of the
6475 PowerPC family you are debugging. The command
6479 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6480 following PowerPC and RS6000 variants:
6482 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6483 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6485 403GC IBM PowerPC 403GC
6486 505 Motorola PowerPC 505
6487 860 Motorola PowerPC 860 or 850
6488 601 Motorola PowerPC 601
6489 602 Motorola PowerPC 602
6490 603 Motorola/IBM PowerPC 603 or 603e
6491 604 Motorola PowerPC 604 or 604e
6492 750 Motorola/IBM PowerPC 750 or 750
6494 At the moment, this command just tells GDB what to name the
6495 special-purpose processor registers. Since almost all the affected
6496 registers are inaccessible to user-level programs, this command is
6497 only useful for remote debugging in its present form.
6501 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6502 more extensive support for HP-UX. Added features include shared
6503 library support, kernel threads and hardware watchpoints for 11.00,
6504 support for HP's ANSI C and C++ compilers, and a compatibility mode
6505 for xdb and dbx commands.
6509 HP's donation includes the new concept of catchpoints, which is a
6510 generalization of the old catch command. On HP-UX, it is now possible
6511 to catch exec, fork, and vfork, as well as library loading.
6513 This means that the existing catch command has changed; its first
6514 argument now specifies the type of catch to be set up. See the
6515 output of "help catch" for a list of catchpoint types.
6517 * Debugging across forks
6519 On HP-UX, you can choose which process to debug when a fork() happens
6524 HP has donated a curses-based terminal user interface (TUI). To get
6525 it, build with --enable-tui. Although this can be enabled for any
6526 configuration, at present it only works for native HP debugging.
6528 * GDB remote protocol additions
6530 A new protocol packet 'X' that writes binary data is now available.
6531 Default behavior is to try 'X', then drop back to 'M' if the stub
6532 fails to respond. The settable variable `remotebinarydownload'
6533 allows explicit control over the use of 'X'.
6535 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6536 full 64-bit address. The command
6538 set remoteaddresssize 32
6540 can be used to revert to the old behaviour. For existing remote stubs
6541 the change should not be noticed, as the additional address information
6544 In order to assist in debugging stubs, you may use the maintenance
6545 command `packet' to send any text string to the stub. For instance,
6547 maint packet heythere
6549 sends the packet "$heythere#<checksum>". Note that it is very easy to
6550 disrupt a debugging session by sending the wrong packet at the wrong
6553 The compare-sections command allows you to compare section data on the
6554 target to what is in the executable file without uploading or
6555 downloading, by comparing CRC checksums.
6557 * Tracing can collect general expressions
6559 You may now collect general expressions at tracepoints. This requires
6560 further additions to the target-side stub; see tracepoint.c and
6561 doc/agentexpr.texi for further details.
6563 * mask-address variable for Mips
6565 For Mips targets, you may control the zeroing of the upper 32 bits of
6566 a 64-bit address by entering `set mask-address on'. This is mainly
6567 of interest to users of embedded R4xxx and R5xxx processors.
6569 * Higher serial baud rates
6571 GDB's serial code now allows you to specify baud rates 57600, 115200,
6572 230400, and 460800 baud. (Note that your host system may not be able
6573 to achieve all of these rates.)
6577 The i960 configuration now includes an initial implementation of a
6578 builtin simulator, contributed by Jim Wilson.
6581 *** Changes in GDB-4.17:
6583 * New native configurations
6585 Alpha GNU/Linux alpha*-*-linux*
6586 Unixware 2.x i[3456]86-unixware2*
6587 Irix 6.x mips*-sgi-irix6*
6588 PowerPC GNU/Linux powerpc-*-linux*
6589 PowerPC Solaris powerpcle-*-solaris*
6590 Sparc GNU/Linux sparc-*-linux*
6591 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6595 Argonaut Risc Chip (ARC) arc-*-*
6596 Hitachi H8/300S h8300*-*-*
6597 Matsushita MN10200 w/simulator mn10200-*-*
6598 Matsushita MN10300 w/simulator mn10300-*-*
6599 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6600 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6601 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6602 Mitsubishi D10V w/simulator d10v-*-*
6603 Mitsubishi M32R/D w/simulator m32r-*-elf*
6604 Tsqware Sparclet sparclet-*-*
6605 NEC V850 w/simulator v850-*-*
6607 * New debugging protocols
6609 ARM with RDI protocol arm*-*-*
6610 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6611 DDB and LSI variants of PMON protocol mips*-*-*
6612 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6613 PowerPC with SDS protocol powerpc{,le}-*-eabi
6614 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6618 All configurations can now understand and use the DWARF 2 debugging
6619 format. The choice is automatic, if the symbol file contains DWARF 2
6624 GDB now includes basic Java language support. This support is
6625 only useful with Java compilers that produce native machine code.
6627 * solib-absolute-prefix and solib-search-path
6629 For SunOS and SVR4 shared libraries, you may now set the prefix for
6630 loading absolute shared library symbol files, and the search path for
6631 locating non-absolute shared library symbol files.
6633 * Live range splitting
6635 GDB can now effectively debug code for which GCC has performed live
6636 range splitting as part of its optimization. See gdb/doc/LRS for
6637 more details on the expected format of the stabs information.
6641 GDB's support for the GNU Hurd, including thread debugging, has been
6642 updated to work with current versions of the Hurd.
6646 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6647 instruction set. ARM GDB automatically detects when Thumb
6648 instructions are in use, and adjusts disassembly and backtracing
6653 GDB's MIPS target configurations now handle the MIP16 16-bit
6658 GDB now includes support for overlays; if an executable has been
6659 linked such that multiple sections are based at the same address, GDB
6660 will decide which section to use for symbolic info. You can choose to
6661 control the decision manually, using overlay commands, or implement
6662 additional target-side support and use "overlay load-target" to bring
6663 in the overlay mapping. Do "help overlay" for more detail.
6667 The command "info symbol <address>" displays information about
6668 the symbol at the specified address.
6672 The standard remote protocol now includes an extension that allows
6673 asynchronous collection and display of trace data. This requires
6674 extensive support in the target-side debugging stub. Tracing mode
6675 includes a new interaction mode in GDB and new commands: see the
6676 file tracepoint.c for more details.
6680 Configurations for embedded MIPS now include a simulator contributed
6681 by Cygnus Solutions. The simulator supports the instruction sets
6682 of most MIPS variants.
6686 Sparc configurations may now include the ERC32 simulator contributed
6687 by the European Space Agency. The simulator is not built into
6688 Sparc targets by default; configure with --enable-sim to include it.
6692 For target configurations that may include multiple variants of a
6693 basic architecture (such as MIPS and SH), you may now set the
6694 architecture explicitly. "set arch" sets, "info arch" lists
6695 the possible architectures.
6697 *** Changes in GDB-4.16:
6699 * New native configurations
6701 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6702 M68K NetBSD m68k-*-netbsd*
6703 PowerPC AIX 4.x powerpc-*-aix*
6704 PowerPC MacOS powerpc-*-macos*
6705 PowerPC Windows NT powerpcle-*-cygwin32
6706 RS/6000 AIX 4.x rs6000-*-aix4*
6710 ARM with RDP protocol arm-*-*
6711 I960 with MON960 i960-*-coff
6712 MIPS VxWorks mips*-*-vxworks*
6713 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6714 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6716 Matra Sparclet sparclet-*-*
6720 The powerpc-eabi configuration now includes the PSIM simulator,
6721 contributed by Andrew Cagney, with assistance from Mike Meissner.
6722 PSIM is a very elaborate model of the PowerPC, including not only
6723 basic instruction set execution, but also details of execution unit
6724 performance and I/O hardware. See sim/ppc/README for more details.
6728 GDB now works with Solaris 2.5.
6730 * Windows 95/NT native
6732 GDB will now work as a native debugger on Windows 95 and Windows NT.
6733 To build it from source, you must use the "gnu-win32" environment,
6734 which uses a DLL to emulate enough of Unix to run the GNU tools.
6735 Further information, binaries, and sources are available at
6736 ftp.cygnus.com, under pub/gnu-win32.
6738 * dont-repeat command
6740 If a user-defined command includes the command `dont-repeat', then the
6741 command will not be repeated if the user just types return. This is
6742 useful if the command is time-consuming to run, so that accidental
6743 extra keystrokes don't run the same command many times.
6745 * Send break instead of ^C
6747 The standard remote protocol now includes an option to send a break
6748 rather than a ^C to the target in order to interrupt it. By default,
6749 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6751 * Remote protocol timeout
6753 The standard remote protocol includes a new variable `remotetimeout'
6754 that allows you to set the number of seconds before GDB gives up trying
6755 to read from the target. The default value is 2.
6757 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6759 By default GDB will automatically keep track of objects as they are
6760 loaded and unloaded by the dynamic linker. By using the command `set
6761 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6762 when shared library events occur, thus allowing you to set breakpoints
6763 in shared libraries which are explicitly loaded by the inferior.
6765 Note this feature does not work on hpux8. On hpux9 you must link
6766 /usr/lib/end.o into your program. This feature should work
6767 automatically on hpux10.
6769 * Irix 5.x hardware watchpoint support
6771 Irix 5 configurations now support the use of hardware watchpoints.
6773 * Mips protocol "SYN garbage limit"
6775 When debugging a Mips target using the `target mips' protocol, you
6776 may set the number of characters that GDB will ignore by setting
6777 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6778 every character. The default value is 1050.
6780 * Recording and replaying remote debug sessions
6782 If you set `remotelogfile' to the name of a file, gdb will write to it
6783 a recording of a remote debug session. This recording may then be
6784 replayed back to gdb using "gdbreplay". See gdbserver/README for
6785 details. This is useful when you have a problem with GDB while doing
6786 remote debugging; you can make a recording of the session and send it
6787 to someone else, who can then recreate the problem.
6789 * Speedups for remote debugging
6791 GDB includes speedups for downloading and stepping MIPS systems using
6792 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6793 and more efficient S-record downloading.
6795 * Memory use reductions and statistics collection
6797 GDB now uses less memory and reports statistics about memory usage.
6798 Try the `maint print statistics' command, for example.
6800 *** Changes in GDB-4.15:
6802 * Psymtabs for XCOFF
6804 The symbol reader for AIX GDB now uses partial symbol tables. This
6805 can greatly improve startup time, especially for large executables.
6807 * Remote targets use caching
6809 Remote targets now use a data cache to speed up communication with the
6810 remote side. The data cache could lead to incorrect results because
6811 it doesn't know about volatile variables, thus making it impossible to
6812 debug targets which use memory mapped I/O devices. `set remotecache
6813 off' turns the data cache off.
6815 * Remote targets may have threads
6817 The standard remote protocol now includes support for multiple threads
6818 in the target system, using new protocol commands 'H' and 'T'. See
6819 gdb/remote.c for details.
6823 If GDB is configured with `--enable-netrom', then it will include
6824 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6825 acts as though it is a bank of ROM on the target board, but you can
6826 write into it over the network. GDB's support consists only of
6827 support for fast loading into the emulated ROM; to debug, you must use
6828 another protocol, such as standard remote protocol. The usual
6829 sequence is something like
6831 target nrom <netrom-hostname>
6833 target remote <netrom-hostname>:1235
6837 GDB now includes support for the Apple Macintosh, as a host only. It
6838 may be run as either an MPW tool or as a standalone application, and
6839 it can debug through the serial port. All the usual GDB commands are
6840 available, but to the target command, you must supply "serial" as the
6841 device type instead of "/dev/ttyXX". See mpw-README in the main
6842 directory for more information on how to build. The MPW configuration
6843 scripts */mpw-config.in support only a few targets, and only the
6844 mips-idt-ecoff target has been tested.
6848 GDB configuration now uses autoconf. This is not user-visible,
6849 but does simplify configuration and building.
6853 GDB now supports hpux10.
6855 *** Changes in GDB-4.14:
6857 * New native configurations
6859 x86 FreeBSD i[345]86-*-freebsd
6860 x86 NetBSD i[345]86-*-netbsd
6861 NS32k NetBSD ns32k-*-netbsd
6862 Sparc NetBSD sparc-*-netbsd
6866 A29K VxWorks a29k-*-vxworks
6867 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6868 CPU32 EST-300 emulator m68*-*-est*
6869 PowerPC ELF powerpc-*-elf
6872 * Alpha OSF/1 support for procfs
6874 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6875 possible to attach to running processes. As the mounting of the /proc
6876 filesystem is optional on the Alpha, GDB automatically determines
6877 the availability of /proc during startup. This can lead to problems
6878 if /proc is unmounted after GDB has been started.
6880 * Arguments to user-defined commands
6882 User commands may accept up to 10 arguments separated by whitespace.
6883 Arguments are accessed within the user command via $arg0..$arg9. A
6886 print $arg0 + $arg1 + $arg2
6888 To execute the command use:
6891 Defines the command "adder" which prints the sum of its three arguments.
6892 Note the arguments are text substitutions, so they may reference variables,
6893 use complex expressions, or even perform inferior function calls.
6895 * New `if' and `while' commands
6897 This makes it possible to write more sophisticated user-defined
6898 commands. Both commands take a single argument, which is the
6899 expression to evaluate, and must be followed by the commands to
6900 execute, one per line, if the expression is nonzero, the list being
6901 terminated by the word `end'. The `if' command list may include an
6902 `else' word, which causes the following commands to be executed only
6903 if the expression is zero.
6905 * Fortran source language mode
6907 GDB now includes partial support for Fortran 77. It will recognize
6908 Fortran programs and can evaluate a subset of Fortran expressions, but
6909 variables and functions may not be handled correctly. GDB will work
6910 with G77, but does not yet know much about symbols emitted by other
6913 * Better HPUX support
6915 Most debugging facilities now work on dynamic executables for HPPAs
6916 running hpux9 or later. You can attach to running dynamically linked
6917 processes, but by default the dynamic libraries will be read-only, so
6918 for instance you won't be able to put breakpoints in them. To change
6919 that behavior do the following before running the program:
6925 This will cause the libraries to be mapped private and read-write.
6926 To revert to the normal behavior, do this:
6932 You cannot set breakpoints or examine data in the library until after
6933 the library is loaded if the function/data symbols do not have
6936 GDB can now also read debug symbols produced by the HP C compiler on
6937 HPPAs (sorry, no C++, Fortran or 68k support).
6939 * Target byte order now dynamically selectable
6941 You can choose which byte order to use with a target system, via the
6942 commands "set endian big" and "set endian little", and you can see the
6943 current setting by using "show endian". You can also give the command
6944 "set endian auto", in which case GDB will use the byte order
6945 associated with the executable. Currently, only embedded MIPS
6946 configurations support dynamic selection of target byte order.
6948 * New DOS host serial code
6950 This version uses DPMI interrupts to handle buffered I/O, so you
6951 no longer need to run asynctsr when debugging boards connected to
6954 *** Changes in GDB-4.13:
6956 * New "complete" command
6958 This lists all the possible completions for the rest of the line, if it
6959 were to be given as a command itself. This is intended for use by emacs.
6961 * Trailing space optional in prompt
6963 "set prompt" no longer adds a space for you after the prompt you set. This
6964 allows you to set a prompt which ends in a space or one that does not.
6966 * Breakpoint hit counts
6968 "info break" now displays a count of the number of times the breakpoint
6969 has been hit. This is especially useful in conjunction with "ignore"; you
6970 can ignore a large number of breakpoint hits, look at the breakpoint info
6971 to see how many times the breakpoint was hit, then run again, ignoring one
6972 less than that number, and this will get you quickly to the last hit of
6975 * Ability to stop printing at NULL character
6977 "set print null-stop" will cause GDB to stop printing the characters of
6978 an array when the first NULL is encountered. This is useful when large
6979 arrays actually contain only short strings.
6981 * Shared library breakpoints
6983 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6984 breakpoints in shared libraries before the executable is run.
6986 * Hardware watchpoints
6988 There is a new hardware breakpoint for the watch command for sparclite
6989 targets. See gdb/sparclite/hw_breakpoint.note.
6991 Hardware watchpoints are also now supported under GNU/Linux.
6995 Annotations have been added. These are for use with graphical interfaces,
6996 and are still experimental. Currently only gdba.el uses these.
6998 * Improved Irix 5 support
7000 GDB now works properly with Irix 5.2.
7002 * Improved HPPA support
7004 GDB now works properly with the latest GCC and GAS.
7006 * New native configurations
7008 Sequent PTX4 i[34]86-sequent-ptx4
7009 HPPA running OSF/1 hppa*-*-osf*
7010 Atari TT running SVR4 m68*-*-sysv4*
7011 RS/6000 LynxOS rs6000-*-lynxos*
7015 OS/9000 i[34]86-*-os9k
7016 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7019 * Hitachi SH7000 and E7000-PC ICE support
7021 There is now support for communicating with the Hitachi E7000-PC ICE.
7022 This is available automatically when GDB is configured for the SH.
7026 As usual, a variety of small fixes and improvements, both generic
7027 and configuration-specific. See the ChangeLog for more detail.
7029 *** Changes in GDB-4.12:
7031 * Irix 5 is now supported
7035 GDB-4.12 on the HPPA has a number of changes which make it unable
7036 to debug the output from the currently released versions of GCC and
7037 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7038 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7039 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7042 *** Changes in GDB-4.11:
7044 * User visible changes:
7048 The "set remotedebug" option is now consistent between the mips remote
7049 target, remote targets using the gdb-specific protocol, UDI (AMD's
7050 debug protocol for the 29k) and the 88k bug monitor. It is now an
7051 integer specifying a debug level (normally 0 or 1, but 2 means more
7052 debugging info for the mips target).
7054 * DEC Alpha native support
7056 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7057 debug info, but GDB works fairly well with the DEC compiler and should
7058 work with a future GCC release. See the README file for a few
7059 Alpha-specific notes.
7061 * Preliminary thread implementation
7063 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7065 * LynxOS native and target support for 386
7067 This release has been hosted on LynxOS 2.2, and also can be configured
7068 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7071 * Improvements in C++ mangling/demangling.
7073 This release has much better g++ debugging, specifically in name
7074 mangling/demangling, virtual function calls, print virtual table,
7075 call methods, ...etc.
7077 *** Changes in GDB-4.10:
7079 * User visible changes:
7081 Remote debugging using the GDB-specific (`target remote') protocol now
7082 supports the `load' command. This is only useful if you have some
7083 other way of getting the stub to the target system, and you can put it
7084 somewhere in memory where it won't get clobbered by the download.
7086 Filename completion now works.
7088 When run under emacs mode, the "info line" command now causes the
7089 arrow to point to the line specified. Also, "info line" prints
7090 addresses in symbolic form (as well as hex).
7092 All vxworks based targets now support a user settable option, called
7093 vxworks-timeout. This option represents the number of seconds gdb
7094 should wait for responses to rpc's. You might want to use this if
7095 your vxworks target is, perhaps, a slow software simulator or happens
7096 to be on the far side of a thin network line.
7100 This release contains support for using a DEC alpha as a GDB host for
7101 cross debugging. Native alpha debugging is not supported yet.
7104 *** Changes in GDB-4.9:
7108 This is the first GDB release which is accompanied by a matching testsuite.
7109 The testsuite requires installation of dejagnu, which should be available
7110 via ftp from most sites that carry GNU software.
7114 'Cfront' style demangling has had its name changed to 'ARM' style, to
7115 emphasize that it was written from the specifications in the C++ Annotated
7116 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7117 disclaimers, it still generated too much confusion with users attempting to
7118 use gdb with AT&T cfront.
7122 GDB now uses a standard remote interface to a simulator library.
7123 So far, the library contains simulators for the Zilog Z8001/2, the
7124 Hitachi H8/300, H8/500 and Super-H.
7126 * New targets supported
7128 H8/300 simulator h8300-hitachi-hms or h8300hms
7129 H8/500 simulator h8500-hitachi-hms or h8500hms
7130 SH simulator sh-hitachi-hms or sh
7131 Z8000 simulator z8k-zilog-none or z8ksim
7132 IDT MIPS board over serial line mips-idt-ecoff
7134 Cross-debugging to GO32 targets is supported. It requires a custom
7135 version of the i386-stub.c module which is integrated with the
7136 GO32 memory extender.
7138 * New remote protocols
7140 MIPS remote debugging protocol.
7142 * New source languages supported
7144 This version includes preliminary support for Chill, a Pascal like language
7145 used by telecommunications companies. Chill support is also being integrated
7146 into the GNU compiler, but we don't know when it will be publically available.
7149 *** Changes in GDB-4.8:
7151 * HP Precision Architecture supported
7153 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7154 version of this support was available as a set of patches from the
7155 University of Utah. GDB does not support debugging of programs
7156 compiled with the HP compiler, because HP will not document their file
7157 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7158 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7160 Many problems in the preliminary version have been fixed.
7162 * Faster and better demangling
7164 We have improved template demangling and fixed numerous bugs in the GNU style
7165 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7166 character types (wchar_t) are now supported. Demangling of each symbol is now
7167 only done once, and is cached when the symbol table for a file is read in.
7168 This results in a small increase in memory usage for C programs, a moderate
7169 increase in memory usage for C++ programs, and a fantastic speedup in
7172 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7173 from the specifications in the Annotated Reference Manual, which AT&T's
7174 compiler does not actually implement.
7176 * G++ multiple inheritance compiler problem
7178 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7179 inheritance lattices was reworked to properly discover ambiguities. We
7180 recently found an example which causes this new algorithm to fail in a
7181 very subtle way, producing bad debug information for those classes.
7182 The file 'gcc.patch' (in this directory) can be applied to gcc to
7183 circumvent the problem. A future GCC release will contain a complete
7186 The previous G++ debug info problem (mentioned below for the gdb-4.7
7187 release) is fixed in gcc version 2.3.2.
7189 * Improved configure script
7191 The `configure' script will now attempt to guess your system type if
7192 you don't supply a host system type. The old scheme of supplying a
7193 host system triplet is preferable over using this. All the magic is
7194 done in the new `config.guess' script. Examine it for details.
7196 We have also brought our configure script much more in line with the FSF's
7197 version. It now supports the --with-xxx options. In particular,
7198 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7199 The resulting GDB will not be able to read arbitrary object file formats --
7200 only the format ``expected'' to be used on the configured target system.
7201 We hope to make this the default in a future release.
7203 * Documentation improvements
7205 There's new internal documentation on how to modify GDB, and how to
7206 produce clean changes to the code. We implore people to read it
7207 before submitting changes.
7209 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7210 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7211 `info' files are also provided. To build `info' files from scratch,
7212 you will need the latest `makeinfo' release, which will be available in
7213 a future texinfo-X.Y release.
7215 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7216 We're not sure exactly which versions have this problem, but it has
7217 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7218 or better. If that isn't possible, there is a patch in
7219 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7220 around this problem.
7224 GDB now supports array constants that can be used in expressions typed in by
7225 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7226 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7229 The new directory `gdb/sparclite' contains a program that demonstrates
7230 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7232 * New native hosts supported
7234 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7235 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7237 * New targets supported
7239 AMD 29k family via UDI a29k-amd-udi or udi29k
7241 * New file formats supported
7243 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7244 HPUX core files, and SCO 3.2v2 core files.
7248 Attaching to processes now works again; thanks for the many bug reports.
7250 We have also stomped on a bunch of core dumps caused by
7251 printf_filtered("%s") problems.
7253 We eliminated a copyright problem on the rpc and ptrace header files
7254 for VxWorks, which was discovered at the last minute during the 4.7
7255 release. You should now be able to build a VxWorks GDB.
7257 You can now interrupt gdb while an attached process is running. This
7258 will cause the attached process to stop, and give control back to GDB.
7260 We fixed problems caused by using too many file descriptors
7261 for reading symbols from object files and libraries. This was
7262 especially a problem for programs that used many (~100) shared
7265 The `step' command now only enters a subroutine if there is line number
7266 information for the subroutine. Otherwise it acts like the `next'
7267 command. Previously, `step' would enter subroutines if there was
7268 any debugging information about the routine. This avoids problems
7269 when using `cc -g1' on MIPS machines.
7271 * Internal improvements
7273 GDB's internal interfaces have been improved to make it easier to support
7274 debugging of multiple languages in the future.
7276 GDB now uses a common structure for symbol information internally.
7277 Minimal symbols (derived from linkage symbols in object files), partial
7278 symbols (from a quick scan of debug information), and full symbols
7279 contain a common subset of information, making it easier to write
7280 shared code that handles any of them.
7282 * New command line options
7284 We now accept --silent as an alias for --quiet.
7288 The memory-mapped-malloc library is now licensed under the GNU Library
7289 General Public License.
7291 *** Changes in GDB-4.7:
7293 * Host/native/target split
7295 GDB has had some major internal surgery to untangle the support for
7296 hosts and remote targets. Now, when you configure GDB for a remote
7297 target, it will no longer load in all of the support for debugging
7298 local programs on the host. When fully completed and tested, this will
7299 ensure that arbitrary host/target combinations are possible.
7301 The primary conceptual shift is to separate the non-portable code in
7302 GDB into three categories. Host specific code is required any time GDB
7303 is compiled on that host, regardless of the target. Target specific
7304 code relates to the peculiarities of the target, but can be compiled on
7305 any host. Native specific code is everything else: it can only be
7306 built when the host and target are the same system. Child process
7307 handling and core file support are two common `native' examples.
7309 GDB's use of /proc for controlling Unix child processes is now cleaner.
7310 It has been split out into a single module under the `target_ops' vector,
7311 plus two native-dependent functions for each system that uses /proc.
7313 * New hosts supported
7315 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7316 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7317 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7319 * New targets supported
7321 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7322 68030 and CPU32 m68030-*-*, m68332-*-*
7324 * New native hosts supported
7326 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7327 (386bsd is not well tested yet)
7328 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7330 * New file formats supported
7332 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7333 supports reading of `a.out.adobe' object files, which are an a.out
7334 format extended with minimal information about multiple sections.
7338 `show copying' is the same as the old `info copying'.
7339 `show warranty' is the same as `info warrantee'.
7340 These were renamed for consistency. The old commands continue to work.
7342 `info handle' is a new alias for `info signals'.
7344 You can now define pre-command hooks, which attach arbitrary command
7345 scripts to any command. The commands in the hook will be executed
7346 prior to the user's command. You can also create a hook which will be
7347 executed whenever the program stops. See gdb.texinfo.
7351 We now deal with Cfront style name mangling, and can even extract type
7352 info from mangled symbols. GDB can automatically figure out which
7353 symbol mangling style your C++ compiler uses.
7355 Calling of methods and virtual functions has been improved as well.
7359 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7360 fixed. This was due to mishandling of the extra N_SO stabs output
7363 We also finally got Ultrix 4.2 running in house, and fixed core file
7364 support, with help from a dozen people on the net.
7366 John M. Farrell discovered that the reason that single-stepping was so
7367 slow on all of the Mips based platforms (primarily SGI and DEC) was
7368 that we were trying to demangle and lookup a symbol used for internal
7369 purposes on every instruction that was being stepped through. Changing
7370 the name of that symbol so that it couldn't be mistaken for a C++
7371 mangled symbol sped things up a great deal.
7373 Rich Pixley sped up symbol lookups in general by getting much smarter
7374 about when C++ symbol mangling is necessary. This should make symbol
7375 completion (TAB on the command line) much faster. It's not as fast as
7376 we'd like, but it's significantly faster than gdb-4.6.
7380 A new user controllable variable 'call_scratch_address' can
7381 specify the location of a scratch area to be used when GDB
7382 calls a function in the target. This is necessary because the
7383 usual method of putting the scratch area on the stack does not work
7384 in systems that have separate instruction and data spaces.
7386 We integrated changes to support the 29k UDI (Universal Debugger
7387 Interface), but discovered at the last minute that we didn't have all
7388 of the appropriate copyright paperwork. We are working with AMD to
7389 resolve this, and hope to have it available soon.
7393 We have sped up the remote serial line protocol, especially for targets
7394 with lots of registers. It now supports a new `expedited status' ('T')
7395 message which can be used in place of the existing 'S' status message.
7396 This allows the remote stub to send only the registers that GDB
7397 needs to make a quick decision about single-stepping or conditional
7398 breakpoints, eliminating the need to fetch the entire register set for
7399 each instruction being stepped through.
7401 The GDB remote serial protocol now implements a write-through cache for
7402 registers, only re-reading the registers if the target has run.
7404 There is also a new remote serial stub for SPARC processors. You can
7405 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7406 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7407 processor with a serial port.
7411 Configure.in files have become much easier to read and modify. A new
7412 `table driven' format makes it more obvious what configurations are
7413 supported, and what files each one uses.
7417 There is a new opcodes library which will eventually contain all of the
7418 disassembly routines and opcode tables. At present, it only contains
7419 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7420 disassembler (binutils/objdump) to share these routines.
7422 The libiberty library is now copylefted under the GNU Library General
7423 Public License. This allows more liberal use, and was done so libg++
7424 can use it. This makes no difference to GDB, since the Library License
7425 grants all the rights from the General Public License.
7429 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7430 reference to the stabs symbol info used by the debugger. It is (as far
7431 as we know) the only published document on this fascinating topic. We
7432 encourage you to read it, compare it to the stabs information on your
7433 system, and send improvements on the document in general (to
7434 bug-gdb@prep.ai.mit.edu).
7436 And, of course, many bugs have been fixed.
7439 *** Changes in GDB-4.6:
7441 * Better support for C++ function names
7443 GDB now accepts as input the "demangled form" of C++ overloaded function
7444 names and member function names, and can do command completion on such names
7445 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7446 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7447 Make use of command completion, it is your friend.
7449 GDB also now accepts a variety of C++ mangled symbol formats. They are
7450 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7451 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7452 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7453 for the list of formats.
7455 * G++ symbol mangling problem
7457 Recent versions of gcc have a bug in how they emit debugging information for
7458 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7459 directory) can be applied to gcc to fix the problem. Alternatively, if you
7460 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7461 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7462 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7465 * New 'maintenance' command
7467 All of the commands related to hacking GDB internals have been moved out of
7468 the main command set, and now live behind the 'maintenance' command. This
7469 can also be abbreviated as 'mt'. The following changes were made:
7471 dump-me -> maintenance dump-me
7472 info all-breakpoints -> maintenance info breakpoints
7473 printmsyms -> maintenance print msyms
7474 printobjfiles -> maintenance print objfiles
7475 printpsyms -> maintenance print psymbols
7476 printsyms -> maintenance print symbols
7478 The following commands are new:
7480 maintenance demangle Call internal GDB demangler routine to
7481 demangle a C++ link name and prints the result.
7482 maintenance print type Print a type chain for a given symbol
7484 * Change to .gdbinit file processing
7486 We now read the $HOME/.gdbinit file before processing the argv arguments
7487 (e.g. reading symbol files or core files). This allows global parameters to
7488 be set, which will apply during the symbol reading. The ./.gdbinit is still
7489 read after argv processing.
7491 * New hosts supported
7493 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7495 GNU/Linux support i386-unknown-linux or linux
7497 We are also including code to support the HP/PA running BSD and HPUX. This
7498 is almost guaranteed not to work, as we didn't have time to test or build it
7499 for this release. We are including it so that the more adventurous (or
7500 masochistic) of you can play with it. We also had major problems with the
7501 fact that the compiler that we got from HP doesn't support the -g option.
7504 * New targets supported
7506 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7508 * More smarts about finding #include files
7510 GDB now remembers the compilation directory for all include files, and for
7511 all files from which C is generated (like yacc and lex sources). This
7512 greatly improves GDB's ability to find yacc/lex sources, and include files,
7513 especially if you are debugging your program from a directory different from
7514 the one that contains your sources.
7516 We also fixed a bug which caused difficulty with listing and setting
7517 breakpoints in include files which contain C code. (In the past, you had to
7518 try twice in order to list an include file that you hadn't looked at before.)
7520 * Interesting infernals change
7522 GDB now deals with arbitrary numbers of sections, where the symbols for each
7523 section must be relocated relative to that section's landing place in the
7524 target's address space. This work was needed to support ELF with embedded
7525 stabs used by Solaris-2.0.
7527 * Bug fixes (of course!)
7529 There have been loads of fixes for the following things:
7530 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7531 i960, stabs, DOS(GO32), procfs, etc...
7533 See the ChangeLog for details.
7535 *** Changes in GDB-4.5:
7537 * New machines supported (host and target)
7539 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7541 SGI Irix-4.x mips-sgi-irix4 or iris4
7543 * New malloc package
7545 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7546 Mmalloc is capable of handling multiple heaps of memory. It is also
7547 capable of saving a heap to a file, and then mapping it back in later.
7548 This can be used to greatly speedup the startup of GDB by using a
7549 pre-parsed symbol table which lives in a mmalloc managed heap. For
7550 more details, please read mmalloc/mmalloc.texi.
7554 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7555 'help info proc' for details.
7557 * MIPS ecoff symbol table format
7559 The code that reads MIPS symbol table format is now supported on all hosts.
7560 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7563 * File name changes for MS-DOS
7565 Many files in the config directories have been renamed to make it easier to
7566 support GDB on MS-DOSe systems (which have very restrictive file name
7567 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7568 environment) is close to working but has some remaining problems. Note
7569 that debugging of DOS programs is not supported, due to limitations
7570 in the ``operating system'', but it can be used to host cross-debugging.
7572 * Cross byte order fixes
7574 Many fixes have been made to support cross debugging of Sparc and MIPS
7575 targets from hosts whose byte order differs.
7577 * New -mapped and -readnow options
7579 If memory-mapped files are available on your system through the 'mmap'
7580 system call, you can use the -mapped option on the `file' or
7581 `symbol-file' commands to cause GDB to write the symbols from your
7582 program into a reusable file. If the program you are debugging is
7583 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7584 Future GDB debugging sessions will notice the presence of this file,
7585 and will quickly map in symbol information from it, rather than reading
7586 the symbol table from the executable program. Using the '-mapped'
7587 option in a GDB `file' or `symbol-file' command has the same effect as
7588 starting GDB with the '-mapped' command-line option.
7590 You can cause GDB to read the entire symbol table immediately by using
7591 the '-readnow' option with any of the commands that load symbol table
7592 information (or on the GDB command line). This makes the command
7593 slower, but makes future operations faster.
7595 The -mapped and -readnow options are typically combined in order to
7596 build a `fred.syms' file that contains complete symbol information.
7597 A simple GDB invocation to do nothing but build a `.syms' file for future
7600 gdb -batch -nx -mapped -readnow programname
7602 The `.syms' file is specific to the host machine on which GDB is run.
7603 It holds an exact image of GDB's internal symbol table. It cannot be
7604 shared across multiple host platforms.
7606 * longjmp() handling
7608 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7609 siglongjmp() without losing control. This feature has not yet been ported to
7610 all systems. It currently works on many 386 platforms, all MIPS-based
7611 platforms (SGI, DECstation, etc), and Sun3/4.
7615 Preliminary work has been put in to support the new Solaris OS from Sun. At
7616 this time, it can control and debug processes, but it is not capable of
7621 As always, many many bug fixes. The major areas were with g++, and mipsread.
7622 People using the MIPS-based platforms should experience fewer mysterious
7623 crashes and trashed symbol tables.
7625 *** Changes in GDB-4.4:
7627 * New machines supported (host and target)
7629 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7631 BSD Reno on Vax vax-dec-bsd
7632 Ultrix on Vax vax-dec-ultrix
7634 * New machines supported (target)
7636 AMD 29000 embedded, using EBMON a29k-none-none
7640 GDB continues to improve its handling of C++. `References' work better.
7641 The demangler has also been improved, and now deals with symbols mangled as
7642 per the Annotated C++ Reference Guide.
7644 GDB also now handles `stabs' symbol information embedded in MIPS
7645 `ecoff' symbol tables. Since the ecoff format was not easily
7646 extensible to handle new languages such as C++, this appeared to be a
7647 good way to put C++ debugging info into MIPS binaries. This option
7648 will be supported in the GNU C compiler, version 2, when it is
7651 * New features for SVR4
7653 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7654 shared libraries. Debugging dynamically linked programs should present
7655 only minor differences from debugging statically linked programs.
7657 The `info proc' command will print out information about any process
7658 on an SVR4 system (including the one you are debugging). At the moment,
7659 it prints the address mappings of the process.
7661 If you bring up GDB on another SVR4 system, please send mail to
7662 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7664 * Better dynamic linking support in SunOS
7666 Reading symbols from shared libraries which contain debugging symbols
7667 now works properly. However, there remain issues such as automatic
7668 skipping of `transfer vector' code during function calls, which
7669 make it harder to debug code in a shared library, than to debug the
7670 same code linked statically.
7674 GDB is now using the latest `getopt' routines from the FSF. This
7675 version accepts the -- prefix for options with long names. GDB will
7676 continue to accept the old forms (-option and +option) as well.
7677 Various single letter abbreviations for options have been explicity
7678 added to the option table so that they won't get overshadowed in the
7679 future by other options that begin with the same letter.
7683 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7684 Many assorted bugs have been handled. Many more remain to be handled.
7685 See the various ChangeLog files (primarily in gdb and bfd) for details.
7688 *** Changes in GDB-4.3:
7690 * New machines supported (host and target)
7692 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7693 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7694 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7696 * Almost SCO Unix support
7698 We had hoped to support:
7699 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7700 (except for core file support), but we discovered very late in the release
7701 that it has problems with process groups that render gdb unusable. Sorry
7702 about that. I encourage people to fix it and post the fixes.
7704 * Preliminary ELF and DWARF support
7706 GDB can read ELF object files on System V Release 4, and can handle
7707 debugging records for C, in DWARF format, in ELF files. This support
7708 is preliminary. If you bring up GDB on another SVR4 system, please
7709 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7714 GDB now uses the latest `readline' library. One user-visible change
7715 is that two tabs will list possible command completions, which previously
7716 required typing M-? (meta-question mark, or ESC ?).
7720 The `stepi' bug that many of you noticed has been squashed.
7721 Many bugs in C++ have been handled. Many more remain to be handled.
7722 See the various ChangeLog files (primarily in gdb and bfd) for details.
7724 * State of the MIPS world (in case you wondered):
7726 GDB can understand the symbol tables emitted by the compilers
7727 supplied by most vendors of MIPS-based machines, including DEC. These
7728 symbol tables are in a format that essentially nobody else uses.
7730 Some versions of gcc come with an assembler post-processor called
7731 mips-tfile. This program is required if you want to do source-level
7732 debugging of gcc-compiled programs. I believe FSF does not ship
7733 mips-tfile with gcc version 1, but it will eventually come with gcc
7736 Debugging of g++ output remains a problem. g++ version 1.xx does not
7737 really support it at all. (If you're lucky, you should be able to get
7738 line numbers and stack traces to work, but no parameters or local
7739 variables.) With some work it should be possible to improve the
7742 When gcc version 2 is released, you will have somewhat better luck.
7743 However, even then you will get confusing results for inheritance and
7746 We will eventually provide full debugging of g++ output on
7747 DECstations. This will probably involve some kind of stabs-in-ecoff
7748 encapulation, but the details have not been worked out yet.
7751 *** Changes in GDB-4.2:
7753 * Improved configuration
7755 Only one copy of `configure' exists now, and it is not self-modifying.
7756 Porting BFD is simpler.
7760 The `step' and `next' commands now only stop at the first instruction
7761 of a source line. This prevents the multiple stops that used to occur
7762 in switch statements, for-loops, etc. `Step' continues to stop if a
7763 function that has debugging information is called within the line.
7767 Lots of small bugs fixed. More remain.
7769 * New host supported (not target)
7771 Intel 386 PC clone running Mach i386-none-mach
7774 *** Changes in GDB-4.1:
7776 * Multiple source language support
7778 GDB now has internal scaffolding to handle several source languages.
7779 It determines the type of each source file from its filename extension,
7780 and will switch expression parsing and number formatting to match the
7781 language of the function in the currently selected stack frame.
7782 You can also specifically set the language to be used, with
7783 `set language c' or `set language modula-2'.
7787 GDB now has preliminary support for the GNU Modula-2 compiler,
7788 currently under development at the State University of New York at
7789 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7790 continue through the fall of 1991 and into 1992.
7792 Other Modula-2 compilers are currently not supported, and attempting to
7793 debug programs compiled with them will likely result in an error as the
7794 symbol table is read. Feel free to work on it, though!
7796 There are hooks in GDB for strict type checking and range checking,
7797 in the `Modula-2 philosophy', but they do not currently work.
7801 GDB can now write to executable and core files (e.g. patch
7802 a variable's value). You must turn this switch on, specify
7803 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7804 by assigning a new value to a variable. Modifications take
7807 * Automatic SunOS shared library reading
7809 When you run your program, GDB automatically determines where its
7810 shared libraries (if any) have been loaded, and reads their symbols.
7811 The `share' command is no longer needed. This also works when
7812 examining core files.
7816 You can specify the number of lines that the `list' command shows.
7819 * New machines supported (host and target)
7821 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7822 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7823 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7825 * New hosts supported (not targets)
7827 IBM RT/PC: romp-ibm-aix or rtpc
7829 * New targets supported (not hosts)
7831 AMD 29000 embedded with COFF a29k-none-coff
7832 AMD 29000 embedded with a.out a29k-none-aout
7833 Ultracomputer remote kernel debug a29k-nyu-kern
7835 * New remote interfaces
7841 *** Changes in GDB-4.0:
7845 Wide output is wrapped at good places to make the output more readable.
7847 Gdb now supports cross-debugging from a host machine of one type to a
7848 target machine of another type. Communication with the target system
7849 is over serial lines. The ``target'' command handles connecting to the
7850 remote system; the ``load'' command will download a program into the
7851 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7852 also supports debugging of realtime processes running under VxWorks,
7853 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7854 stub on the target system.
7856 New CPUs supported include the AMD 29000 and Intel 960.
7858 GDB now reads object files and symbol tables via a ``binary file''
7859 library, which allows a single copy of GDB to debug programs of multiple
7860 object file types such as a.out and coff.
7862 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7863 refcard.dvi and refcard.ps are available to format it).
7866 * Control-Variable user interface simplified
7868 All variables that control the operation of the debugger can be set
7869 by the ``set'' command, and displayed by the ``show'' command.
7871 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7872 ``Show prompt'' produces the response:
7873 Gdb's prompt is new-gdb=>.
7875 What follows are the NEW set commands. The command ``help set'' will
7876 print a complete list of old and new set commands. ``help set FOO''
7877 will give a longer description of the variable FOO. ``show'' will show
7878 all of the variable descriptions and their current settings.
7880 confirm on/off: Enables warning questions for operations that are
7881 hard to recover from, e.g. rerunning the program while
7882 it is already running. Default is ON.
7884 editing on/off: Enables EMACS style command line editing
7885 of input. Previous lines can be recalled with
7886 control-P, the current line can be edited with control-B,
7887 you can search for commands with control-R, etc.
7890 history filename NAME: NAME is where the gdb command history
7891 will be stored. The default is .gdb_history,
7892 or the value of the environment variable
7895 history size N: The size, in commands, of the command history. The
7896 default is 256, or the value of the environment variable
7899 history save on/off: If this value is set to ON, the history file will
7900 be saved after exiting gdb. If set to OFF, the
7901 file will not be saved. The default is OFF.
7903 history expansion on/off: If this value is set to ON, then csh-like
7904 history expansion will be performed on
7905 command line input. The default is OFF.
7907 radix N: Sets the default radix for input and output. It can be set
7908 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7909 in the current radix, so "set radix 10" is always a no-op.
7911 height N: This integer value is the number of lines on a page. Default
7912 is 24, the current `stty rows'' setting, or the ``li#''
7913 setting from the termcap entry matching the environment
7916 width N: This integer value is the number of characters on a line.
7917 Default is 80, the current `stty cols'' setting, or the ``co#''
7918 setting from the termcap entry matching the environment
7921 Note: ``set screensize'' is obsolete. Use ``set height'' and
7922 ``set width'' instead.
7924 print address on/off: Print memory addresses in various command displays,
7925 such as stack traces and structure values. Gdb looks
7926 more ``symbolic'' if you turn this off; it looks more
7927 ``machine level'' with it on. Default is ON.
7929 print array on/off: Prettyprint arrays. New convenient format! Default
7932 print demangle on/off: Print C++ symbols in "source" form if on,
7935 print asm-demangle on/off: Same, for assembler level printouts
7938 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7941 * Support for Epoch Environment.
7943 The epoch environment is a version of Emacs v18 with windowing. One
7944 new command, ``inspect'', is identical to ``print'', except that if you
7945 are running in the epoch environment, the value is printed in its own
7949 * Support for Shared Libraries
7951 GDB can now debug programs and core files that use SunOS shared libraries.
7952 Symbols from a shared library cannot be referenced
7953 before the shared library has been linked with the program (this
7954 happens after you type ``run'' and before the function main() is entered).
7955 At any time after this linking (including when examining core files
7956 from dynamically linked programs), gdb reads the symbols from each
7957 shared library when you type the ``sharedlibrary'' command.
7958 It can be abbreviated ``share''.
7960 sharedlibrary REGEXP: Load shared object library symbols for files
7961 matching a unix regular expression. No argument
7962 indicates to load symbols for all shared libraries.
7964 info sharedlibrary: Status of loaded shared libraries.
7969 A watchpoint stops execution of a program whenever the value of an
7970 expression changes. Checking for this slows down execution
7971 tremendously whenever you are in the scope of the expression, but is
7972 quite useful for catching tough ``bit-spreader'' or pointer misuse
7973 problems. Some machines such as the 386 have hardware for doing this
7974 more quickly, and future versions of gdb will use this hardware.
7976 watch EXP: Set a watchpoint (breakpoint) for an expression.
7978 info watchpoints: Information about your watchpoints.
7980 delete N: Deletes watchpoint number N (same as breakpoints).
7981 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7982 enable N: Re-enables watchpoint number N (same as breakpoints).
7985 * C++ multiple inheritance
7987 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7990 * C++ exception handling
7992 Gdb now supports limited C++ exception handling. Besides the existing
7993 ability to breakpoint on an exception handler, gdb can breakpoint on
7994 the raising of an exception (before the stack is peeled back to the
7997 catch FOO: If there is a FOO exception handler in the dynamic scope,
7998 set a breakpoint to catch exceptions which may be raised there.
7999 Multiple exceptions (``catch foo bar baz'') may be caught.
8001 info catch: Lists all exceptions which may be caught in the
8002 current stack frame.
8005 * Minor command changes
8007 The command ``call func (arg, arg, ...)'' now acts like the print
8008 command, except it does not print or save a value if the function's result
8009 is void. This is similar to dbx usage.
8011 The ``up'' and ``down'' commands now always print the frame they end up
8012 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8013 frames without printing.
8015 * New directory command
8017 'dir' now adds directories to the FRONT of the source search path.
8018 The path starts off empty. Source files that contain debug information
8019 about the directory in which they were compiled can be found even
8020 with an empty path; Sun CC and GCC include this information. If GDB can't
8021 find your source file in the current directory, type "dir .".
8023 * Configuring GDB for compilation
8025 For normal use, type ``./configure host''. See README or gdb.texinfo
8028 GDB now handles cross debugging. If you are remotely debugging between
8029 two different machines, type ``./configure host -target=targ''.
8030 Host is the machine where GDB will run; targ is the machine
8031 where the program that you are debugging will run.