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.
80 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
81 and "org.gnu.gdb.arc.aux". The old names are still supported but
82 must be considered obsolete. They will be deprecated after some
85 * Help and apropos commands will now show the documentation of a
86 command only once, even if that command has one or more aliases.
87 These commands now show the command name, then all of its aliases,
88 and finally the description of the command.
90 * 'help aliases' now shows only the user defined aliases. GDB predefined
91 aliases are shown together with their aliased command.
93 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
94 debugging information as well as source code.
96 When built with debuginfod, GDB can automatically query debuginfod
97 servers for the separate debug files and source code of the executable
100 To build GDB with debuginfod, pass --with-debuginfod to configure (this
101 requires libdebuginfod, the debuginfod client library).
103 debuginfod is distributed with elfutils, starting with version 0.178.
105 You can get the latest version from https://sourceware.org/elfutils.
107 * Multi-target debugging support
109 GDB now supports debugging multiple target connections
110 simultaneously. For example, you can now have each inferior
111 connected to different remote servers running in different machines,
112 or have one inferior debugging a local native process, an inferior
113 debugging a core dump, etc.
115 This support is experimental and comes with some limitations -- you
116 can only resume multiple targets simultaneously if all targets
117 support non-stop mode, and all remote stubs or servers must support
118 the same set of remote protocol features exactly. See also "info
119 connections" and "add-inferior -no-connection" below, and "maint set
120 target-non-stop" in the user manual.
122 * New features in the GDB remote stub, GDBserver
124 ** GDBserver is now supported on ARC GNU/Linux.
126 ** GDBserver is now supported on RISC-V GNU/Linux.
128 ** GDBserver no longer supports these host triplets:
139 i[34567]86-*-mingw32ce*
141 * Debugging MS-Windows processes now sets $_exitsignal when the
142 inferior is terminated by a signal, instead of setting $_exitcode.
144 * Multithreaded symbol loading has now been enabled by default on systems
145 that support it (see entry for GDB 9, below), providing faster
146 performance for programs with many symbols.
148 * The $_siginfo convenience variable now also works on Windows targets,
149 and will display the EXCEPTION_RECORD of the last handled exception.
151 * TUI windows can now be arranged horizontally.
153 * The command history filename can now be set to the empty string
154 either using 'set history filename' or by setting 'GDBHISTFILE=' in
155 the environment. The effect of setting this filename to the empty
156 string is that GDB will not try to load any previous command
159 * On Windows targets, it is now possible to debug 32-bit programs with a
164 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
165 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
166 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
167 running process, this new option indicates whether to detect
168 a mismatch between the current executable file loaded by GDB and the
169 executable file used to start the process. If 'ask', the default,
170 display a warning and ask the user whether to load the process
171 executable file; if 'warn', just display a warning; if 'off', don't
172 attempt to detect a mismatch.
174 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
175 Define a new TUI layout, specifying its name and the windows that
178 maintenance print xml-tdesc [FILE]
179 Prints the current target description as an XML document. If the
180 optional FILE is provided (which is an XML target description) then
181 the target description is read from FILE into GDB, and then
184 maintenance print core-file-backed-mappings
185 Prints file-backed mappings loaded from a core file's note section.
186 Output is expected to be similar to that of "info proc mappings".
188 set debug fortran-array-slicing on|off
189 show debug fortran-array-slicing
190 Print debugging when taking slices of Fortran arrays.
192 set fortran repack-array-slices on|off
193 show fortran repack-array-slices
194 When taking slices from Fortran arrays and strings, if the slice is
195 non-contiguous within the original value then, when this option is
196 on, the new value will be repacked into a single contiguous value.
197 When this option is off, then the value returned will consist of a
198 descriptor that describes the slice within the memory of the
199 original parent value.
203 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
204 The alias command can now specify default args for an alias.
205 GDB automatically prepends the alias default args to the argument list
206 provided explicitly by the user.
207 For example, to have a backtrace with full details, you can define
209 'alias bt_ALL = backtrace -entry-values both -frame-arg all
210 -past-main -past-entry -full'.
211 Alias default arguments can also use a set of nested 'with' commands,
212 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
213 defines the alias pp10 that will pretty print a maximum of 10 elements
214 of the given expression (if the expression is an array).
218 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
223 ** gdb.register_window_type can be used to implement new TUI windows
226 ** Dynamic types can now be queried. gdb.Type has a new attribute,
227 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
228 field of a dynamic type may have None for its "bitpos" attribute
231 ** Commands written in Python can be in the "TUI" help class by
232 registering with the new constant gdb.COMMAND_TUI.
234 ** New method gdb.PendingFrame.architecture () to retrieve the
235 architecture of the pending frame.
237 ** New gdb.Architecture.registers method that returns a
238 gdb.RegisterDescriptorIterator object, an iterator that returns
239 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
240 way to query the registers available for an architecture.
242 ** New gdb.Architecture.register_groups method that returns a
243 gdb.RegisterGroupIterator object, an iterator that returns
244 gdb.RegisterGroup objects. The new RegisterGroup is a way to
245 discover the available register groups.
249 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
251 ** Procedures 'memory-port-read-buffer-size',
252 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
253 and 'set-memory-port-write-buffer-size!' are deprecated. When
254 using Guile 2.2 and later, users who need to control the size of
255 a memory port's internal buffer can use the 'setvbuf' procedure.
259 * 'thread-exited' event is now available in the annotations interface.
261 * New built-in convenience variables $_gdb_major and $_gdb_minor
262 provide the GDB version. They are handy for conditionally using
263 features available only in or since specific GDB versions, in
264 scripts that should work error-free with many different versions,
265 such as in system-wide init files.
267 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
268 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
269 of the GDB settings and the GDB maintenance settings. They are handy
270 for changing the logic of user defined commands depending on the
271 current GDB settings.
273 * GDB now supports Thread Local Storage (TLS) variables on several
274 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
275 architectures require kernel changes. TLS is not yet supported for
276 amd64 and i386 process core dumps.
278 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
279 addresses that required unmasking are shown in the backtrace with the
282 * Two new convenience functions $_cimag and $_creal that extract the
283 imaginary and real parts respectively from complex numbers.
285 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
286 provide the exitcode or exit status of the shell commands launched by
287 GDB commands such as "shell", "pipe" and "make".
289 * The command define-prefix can now define user defined prefix commands.
290 User defined commands can now be defined using these user defined prefix
293 * Command names can now use the . character.
295 * The RX port now supports XML target descriptions.
297 * GDB now shows the Ada task names at more places, e.g. in task switching
300 * GDB can now be compiled with Python 3 on Windows.
302 * New convenience variable $_ada_exception holds the address of the
303 Ada exception being thrown. This is set by Ada-related catchpoints.
305 * GDB can now place breakpoints on nested functions and subroutines in
306 Fortran code. The '::' operator can be used between parent and
307 child scopes when placing breakpoints, for example:
309 (gdb) break outer_function::inner_function
311 The 'outer_function::' prefix is only needed if 'inner_function' is
312 not visible in the current scope.
314 * In addition to the system-wide gdbinit file, if configured with
315 --with-system-gdbinit-dir, GDB will now also load files in that directory
316 as system gdbinit files, unless the -nx or -n flag is provided. Files
317 with extensions .gdb, .py and .scm are supported as long as GDB was
318 compiled with support for that language.
320 * GDB now supports multithreaded symbol loading for higher performance.
321 This feature is still in testing, so it is disabled by default. You
322 can turn it on using 'maint set worker-threads unlimited'.
326 ** The gdb.Value type has a new method 'format_string' which returns a
327 string representing the value. The formatting is controlled by the
328 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
329 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
330 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
332 ** gdb.Type has a new property 'objfile' which returns the objfile the
335 ** The frame information printed by the python frame filtering code
336 is now consistent with what the 'backtrace' command prints when
337 there are no filters, or when the 'backtrace' '-no-filters' option
340 ** The new function gdb.lookup_static_symbol can be used to look up
341 symbols with static linkage.
343 ** The new function gdb.lookup_static_symbols can be used to look up
344 all static symbols with static linkage.
346 ** gdb.Objfile has new methods 'lookup_global_symbol' and
347 'lookup_static_symbol' to lookup a symbol from this objfile only.
349 ** gdb.Block now supports the dictionary syntax for accessing symbols in
350 this block (e.g. block['local_variable']).
354 | [COMMAND] | SHELL_COMMAND
355 | -d DELIM COMMAND DELIM SHELL_COMMAND
356 pipe [COMMAND] | SHELL_COMMAND
357 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
358 Executes COMMAND and sends its output to SHELL_COMMAND.
359 With no COMMAND, repeat the last executed command
360 and send its output to SHELL_COMMAND.
362 define-prefix COMMAND
363 Define or mark a command as a user-defined prefix command.
365 with SETTING [VALUE] [-- COMMAND]
366 w SETTING [VALUE] [-- COMMAND]
367 Temporarily set SETTING, run COMMAND, and restore SETTING.
368 Usage: with SETTING -- COMMAND
369 With no COMMAND, repeats the last executed command.
370 SETTING is any GDB setting you can change with the "set"
371 subcommands. For example, 'with language c -- print someobj'
372 temporarily switches to the C language in order to print someobj.
373 Settings can be combined: 'w lang c -- w print elements unlimited --
374 usercmd' switches to the C language and runs usercmd with no limit
375 of array elements to print.
377 maint with SETTING [VALUE] [-- COMMAND]
378 Like "with", but works with "maintenance set" settings.
380 set may-call-functions [on|off]
381 show may-call-functions
382 This controls whether GDB will attempt to call functions in
383 the program, such as with expressions in the print command. It
384 defaults to on. Calling functions in the program being debugged
385 can have undesired side effects. It is now possible to forbid
386 such function calls. If function calls are forbidden, GDB will throw
387 an error when a command (such as print expression) calls a function
390 set print finish [on|off]
392 This controls whether the `finish' command will display the value
393 that is returned by the current function. When `off', the value is
394 still entered into the value history, but it is not printed. The
399 Allows deeply nested structures to be simplified when printing by
400 replacing deeply nested parts (beyond the max-depth) with ellipses.
401 The default max-depth is 20, but this can be set to unlimited to get
402 the old behavior back.
404 set print raw-values [on|off]
405 show print raw-values
406 By default, GDB applies the enabled pretty printers when printing a
407 value. This allows to ignore the enabled pretty printers for a series
408 of commands. The default is 'off'.
410 set logging debugredirect [on|off]
411 By default, GDB debug output will go to both the terminal and the logfile.
412 Set if you want debug output to go only to the log file.
414 set style title foreground COLOR
415 set style title background COLOR
416 set style title intensity VALUE
417 Control the styling of titles.
419 set style highlight foreground COLOR
420 set style highlight background COLOR
421 set style highlight intensity VALUE
422 Control the styling of highlightings.
424 maint set worker-threads
425 maint show worker-threads
426 Control the number of worker threads that can be used by GDB. The
427 default is 0. "unlimited" lets GDB choose a number that is
428 reasonable. Currently worker threads are only used when demangling
429 the names of linker symbols.
431 set style tui-border foreground COLOR
432 set style tui-border background COLOR
433 Control the styling of TUI borders.
435 set style tui-active-border foreground COLOR
436 set style tui-active-border background COLOR
437 Control the styling of the active TUI border.
439 maint set test-settings KIND
440 maint show test-settings KIND
441 A set of commands used by the testsuite for exercising the settings
444 maint set tui-resize-message [on|off]
445 maint show tui-resize-message
446 Control whether GDB prints a message each time the terminal is
447 resized when in TUI mode. This is primarily useful for testing the
450 set print frame-info [short-location|location|location-and-address
451 |source-and-location|source-line|auto]
452 show print frame-info
453 This controls what frame information is printed by the commands printing
454 a frame. This setting will e.g. influence the behaviour of 'backtrace',
455 'frame', 'stepi'. The python frame filtering also respect this setting.
456 The 'backtrace' '-frame-info' option can override this global setting.
458 set tui compact-source
459 show tui compact-source
461 Enable the "compact" display mode for the TUI source window. The
462 compact display uses only as much space as is needed for the line
463 numbers in the current file, and only a single space to separate the
464 line numbers from the source.
466 info modules [-q] [REGEXP]
467 Return a list of Fortran modules matching REGEXP, or all modules if
470 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
471 Return a list of functions within all modules, grouped by module.
472 The list of functions can be restricted with the optional regular
473 expressions. MODULE_REGEXP matches against the module name,
474 TYPE_REGEXP matches against the function type signature, and REGEXP
475 matches against the function name.
477 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
478 Return a list of variables within all modules, grouped by module.
479 The list of variables can be restricted with the optional regular
480 expressions. MODULE_REGEXP matches against the module name,
481 TYPE_REGEXP matches against the variable type, and REGEXP matches
482 against the variable name.
484 set debug remote-packet-max-chars
485 show debug remote-packet-max-chars
486 Controls the number of characters to output in a remote packet when using
488 The default is 512 bytes.
491 Lists the target connections currently in use.
496 The "help" command uses the title style to enhance the
497 readibility of its output by styling the classes and
501 Similarly to "help", the "apropos" command also uses the
502 title style for the command names. "apropos" accepts now
503 a flag "-v" (verbose) to show the full documentation
504 of matching commands and to use the highlight style to mark
505 the documentation parts matching REGEXP.
509 The GDB printf and eval commands can now print C-style and Ada-style
510 string convenience variables without calling functions in the program.
511 This allows to do formatted printing of strings without having
512 a running inferior, or when debugging a core dump.
514 info sources [-dirname | -basename] [--] [REGEXP]
515 This command has now optional arguments to only print the files
516 whose names match REGEXP. The arguments -dirname and -basename
517 allow to restrict matching respectively to the dirname and basename
521 The "show style" and its subcommands are now styling
522 a style name in their output using its own style, to help
523 the user visualize the different styles.
525 set print frame-arguments
526 The new value 'presence' indicates to only indicate the presence of
527 arguments using ..., instead of printing argument names and values.
529 set print raw-frame-arguments
530 show print raw-frame-arguments
532 These commands replace the similarly-named "set/show print raw
533 frame-arguments" commands (now with a dash instead of a space). The
534 old commands are now deprecated and may be removed in a future
537 add-inferior [-no-connection]
538 The add-inferior command now supports a "-no-connection" flag that
539 makes the new inferior start with no target connection associated.
540 By default, the new inferior inherits the target connection of the
541 current inferior. See also "info connections".
544 This command's output now includes a new "Connection" column
545 indicating which target connection an inferior is bound to. See
546 "info connections" above.
548 maint test-options require-delimiter
549 maint test-options unknown-is-error
550 maint test-options unknown-is-operand
551 maint show test-options-completion-result
552 Commands used by the testsuite to validate the command options
555 focus, winheight, +, -, >, <
556 These commands are now case-sensitive.
558 * New command options, command completion
560 GDB now has a standard infrastructure to support dash-style command
561 options ('-OPT'). One benefit is that commands that use it can
562 easily support completion of command line arguments. Try "CMD
563 -[TAB]" or "help CMD" to find options supported by a command. Over
564 time, we intend to migrate most commands to this infrastructure. A
565 number of commands got support for new command options in this
568 ** The "print" and "compile print" commands now support a number of
569 options that allow overriding relevant global print settings as
570 set by "set print" subcommands:
574 -array-indexes [on|off]
575 -elements NUMBER|unlimited
580 -repeats NUMBER|unlimited
581 -static-members [on|off]
586 Note that because the "print"/"compile print" commands accept
587 arbitrary expressions which may look like options (including
588 abbreviations), if you specify any command option, then you must
589 use a double dash ("--") to mark the end of argument processing.
591 ** The "backtrace" command now supports a number of options that
592 allow overriding relevant global print settings as set by "set
593 backtrace" and "set print" subcommands:
595 -entry-values no|only|preferred|if-needed|both|compact|default
596 -frame-arguments all|scalars|none
597 -raw-frame-arguments [on|off]
598 -frame-info auto|source-line|location|source-and-location
599 |location-and-address|short-location
603 In addition, the full/no-filters/hide qualifiers are now also
604 exposed as command options too:
610 ** The "frame apply", "tfaas" and "faas" commands similarly now
611 support the following options:
616 ** The new "info sources" options -dirname and -basename options
617 are using the standard '-OPT' infrastructure.
619 All options above can also be abbreviated. The argument of boolean
620 (on/off) options can be 0/1 too, and also the argument is assumed
621 "on" if omitted. This allows writing compact command invocations,
624 (gdb) p -ra -p -o 0 -- *myptr
626 The above is equivalent to:
628 (gdb) print -raw-values -pretty -object off -- *myptr
630 ** The "info types" command now supports the '-q' flag to disable
631 printing of some header information in a similar fashion to "info
632 variables" and "info functions".
634 ** The "info variables", "info functions", and "whereis" commands
635 now take a '-n' flag that excludes non-debug symbols (symbols
636 from the symbol table, not from the debug info such as DWARF)
639 * Completion improvements
641 ** GDB can now complete the options of the "thread apply all" and
642 "taas" commands, and their "-ascending" option can now be
645 ** GDB can now complete the options of the "info threads", "info
646 functions", "info variables", "info locals", and "info args"
649 ** GDB can now complete the options of the "compile file" and
650 "compile code" commands. The "compile file" command now
651 completes on filenames.
653 ** GDB can now complete the backtrace command's
654 "full/no-filters/hide" qualifiers.
656 * In settings, you can now abbreviate "unlimited".
658 E.g., "set print elements u" is now equivalent to "set print
664 This lists all the possible completions for the rest of the line, if it
665 were to be given as a command itself. This is intended for use by MI
666 frontends in cases when separate CLI and MI channels cannot be used.
668 -catch-throw, -catch-rethrow, and -catch-catch
669 These can be used to catch C++ exceptions in a similar fashion to
670 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
672 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
673 These commands are the MI equivalent of the CLI commands 'info
674 functions', 'info types', and 'info variables' respectively.
676 -symbol-info-modules, this is the MI equivalent of the CLI 'info
679 -symbol-info-module-functions and -symbol-info-module-variables.
680 These commands are the MI equivalent of the CLI commands 'info
681 module functions' and 'info module variables'.
685 ** The default version of the MI interpreter is now 3 (-i=mi3).
687 ** The output of information about multi-location breakpoints (which is
688 syntactically incorrect in MI 2) has changed in MI 3. This affects
689 the following commands and events:
693 - =breakpoint-created
694 - =breakpoint-modified
696 The -fix-multi-location-breakpoint-output command can be used to enable
697 this behavior with previous MI versions.
699 ** Backtraces and frames include a new optional field addr_flags which is
700 given after the addr field. On AArch64 this contains PAC if the address
701 has been masked in the frame. On all other targets the field is not
706 The testsuite now creates the files gdb.cmd (containing the arguments
707 used to launch GDB) and gdb.in (containing all the commands sent to
708 GDB) in the output directory for each test script. Multiple invocations
709 are appended with .1, .2, .3 etc.
711 * Building GDB and GDBserver now requires GNU make >= 3.82.
713 Using another implementation of the make program or an earlier version of
714 GNU make to build GDB or GDBserver is not supported.
716 * Building GDB now requires GNU readline >= 7.0.
718 GDB now bundles GNU readline 8.0, but if you choose to use
719 --with-system-readline, only readline >= 7.0 can be used.
721 * The TUI SingleKey keymap is now named "SingleKey". This can be used
722 from .inputrc to bind keys in this keymap. This feature is only
723 available when gdb is built against GNU readline 8.0 or later.
725 * Removed targets and native configurations
727 GDB no longer supports debugging the Cell Broadband Engine. This includes
728 both debugging standalone Cell/B.E. SPU applications and integrated debugging
729 of Cell/B.E. applications that use both the PPU and SPU architectures.
735 * Removed targets and native configurations
737 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
740 *** Changes in GDB 8.3
742 * GDB and GDBserver now support access to additional registers on
743 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
746 * GDB now has experimental support for the compilation and injection of
747 C++ source code into the inferior. This beta release does not include
748 support for several language features, such as templates, constructors,
751 This feature requires GCC 7.1 or higher built with libcp1.so
754 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
755 can be passed using the '[ADDRESS]:PORT' notation, or the regular
756 'ADDRESS:PORT' method.
758 * DWARF index cache: GDB can now automatically save indices of DWARF
759 symbols on disk to speed up further loading of the same binaries.
761 * Ada task switching is now supported on aarch64-elf targets when
762 debugging a program using the Ravenscar Profile. For more information,
763 see the "Tasking Support when using the Ravenscar Profile" section
764 in the GDB user manual.
766 * GDB in batch mode now exits with status 1 if the last command to be
769 * The RISC-V target now supports target descriptions.
771 * System call catchpoints now support system call aliases on FreeBSD.
772 When the ABI of a system call changes in FreeBSD, this is
773 implemented by leaving a compatibility system call using the old ABI
774 at the existing number and allocating a new system call number for
775 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
776 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
777 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
778 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
779 so that a system call catchpoint for the 'kevent' system call will
780 catch invocations of both the 'kevent' and 'freebsd11_kevent'
781 binaries. This ensures that 'kevent' system calls are caught for
782 binaries using either the old or new ABIs.
784 * Terminal styling is now available for the CLI and the TUI. GNU
785 Source Highlight can additionally be used to provide styling of
786 source code snippets. See the "set style" commands, below, for more
789 * Removed support for old demangling styles arm, edg, gnu, hp and
794 set debug compile-cplus-types
795 show debug compile-cplus-types
796 Control the display of debug output about type conversion in the
797 C++ compile feature. Commands have no effect while compiling
802 Control whether debug output about files/functions skipping is
805 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
806 Apply a command to some frames.
807 FLAG arguments allow to control what output to produce and how to handle
808 errors raised when applying COMMAND to a frame.
811 Apply a command to all threads (ignoring errors and empty output).
812 Shortcut for 'thread apply all -s COMMAND'.
815 Apply a command to all frames (ignoring errors and empty output).
816 Shortcut for 'frame apply all -s COMMAND'.
819 Apply a command to all frames of all threads (ignoring errors and empty
821 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
823 maint set dwarf unwinders (on|off)
824 maint show dwarf unwinders
825 Control whether DWARF unwinders can be used.
828 Display a list of open files for a process.
832 Changes to the "frame", "select-frame", and "info frame" CLI commands.
833 These commands all now take a frame specification which
834 is either a frame level, or one of the keywords 'level', 'address',
835 'function', or 'view' followed by a parameter. Selecting a frame by
836 address, or viewing a frame outside the current backtrace now
837 requires the use of a keyword. Selecting a frame by level is
838 unchanged. The MI comment "-stack-select-frame" is unchanged.
840 target remote FILENAME
841 target extended-remote FILENAME
842 If FILENAME is a Unix domain socket, GDB will attempt to connect
843 to this socket instead of opening FILENAME as a character device.
845 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
846 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
847 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
848 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
849 These commands can now print only the searched entities
850 matching the provided regexp(s), giving a condition
851 on the entity names or entity types. The flag -q disables
852 printing headers or informations messages.
858 These commands now determine the syntax for the shown entities
859 according to the language chosen by `set language'. In particular,
860 `set language auto' means to automatically choose the language of
863 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
864 The 'thread apply' command accepts new FLAG arguments.
865 FLAG arguments allow to control what output to produce and how to handle
866 errors raised when applying COMMAND to a thread.
868 set tui tab-width NCHARS
869 show tui tab-width NCHARS
870 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
872 set style enabled [on|off]
874 Enable or disable terminal styling. Styling is enabled by default
875 on most hosts, but disabled by default when in batch mode.
877 set style sources [on|off]
879 Enable or disable source code styling. Source code styling is
880 enabled by default, but only takes effect if styling in general is
881 enabled, and if GDB was linked with GNU Source Highlight.
883 set style filename foreground COLOR
884 set style filename background COLOR
885 set style filename intensity VALUE
886 Control the styling of file names.
888 set style function foreground COLOR
889 set style function background COLOR
890 set style function intensity VALUE
891 Control the styling of function names.
893 set style variable foreground COLOR
894 set style variable background COLOR
895 set style variable intensity VALUE
896 Control the styling of variable names.
898 set style address foreground COLOR
899 set style address background COLOR
900 set style address intensity VALUE
901 Control the styling of addresses.
905 ** The '-data-disassemble' MI command now accepts an '-a' option to
906 disassemble the whole function surrounding the given program
907 counter value or function name. Support for this feature can be
908 verified by using the "-list-features" command, which should
909 contain "data-disassemble-a-option".
911 ** Command responses and notifications that include a frame now include
912 the frame's architecture in a new "arch" attribute.
914 * New native configurations
916 GNU/Linux/RISC-V riscv*-*-linux*
917 FreeBSD/riscv riscv*-*-freebsd*
921 GNU/Linux/RISC-V riscv*-*-linux*
923 CSKY GNU/LINUX csky*-*-linux
924 FreeBSD/riscv riscv*-*-freebsd*
926 GNU/Linux/OpenRISC or1k*-*-linux*
930 GDB no longer supports native debugging on versions of MS-Windows
935 ** GDB no longer supports Python versions less than 2.6.
937 ** The gdb.Inferior type has a new 'progspace' property, which is the program
938 space associated to that inferior.
940 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
941 of objfiles associated to that program space.
943 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
944 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
947 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
948 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
949 correct and did not work properly.
951 ** The gdb.Value type has a new constructor, which is used to construct a
952 gdb.Value from a Python buffer object and a gdb.Type.
958 Enable or disable the undefined behavior sanitizer. This is
959 disabled by default, but passing --enable-ubsan=yes or
960 --enable-ubsan=auto to configure will enable it. Enabling this can
961 cause a performance penalty. The undefined behavior sanitizer was
962 first introduced in GCC 4.9.
964 *** Changes in GDB 8.2
966 * The 'set disassembler-options' command now supports specifying options
969 * The 'symbol-file' command now accepts an '-o' option to add a relative
970 offset to all sections.
972 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
973 a relative offset to all sections, but it allows to override the load
974 address of individual sections using '-s'.
976 * The 'add-symbol-file' command no longer requires the second argument
977 (address of the text section).
979 * The endianness used with the 'set endian auto' mode in the absence of
980 an executable selected for debugging is now the last endianness chosen
981 either by one of the 'set endian big' and 'set endian little' commands
982 or by inferring from the last executable used, rather than the startup
985 * The pager now allows a "c" response, meaning to disable the pager
986 for the rest of the current command.
988 * The commands 'info variables/functions/types' now show the source line
989 numbers of symbol definitions when available.
991 * 'info proc' now works on running processes on FreeBSD systems and core
992 files created on FreeBSD systems.
994 * C expressions can now use _Alignof, and C++ expressions can now use
997 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
998 the vector length while the process is running.
1004 Control display of debugging info regarding the FreeBSD native target.
1006 set|show varsize-limit
1007 This new setting allows the user to control the maximum size of Ada
1008 objects being printed when those objects have a variable type,
1009 instead of that maximum size being hardcoded to 65536 bytes.
1011 set|show record btrace cpu
1012 Controls the processor to be used for enabling errata workarounds for
1013 branch trace decode.
1015 maint check libthread-db
1016 Run integrity checks on the current inferior's thread debugging
1019 maint set check-libthread-db (on|off)
1020 maint show check-libthread-db
1021 Control whether to run integrity checks on inferior specific thread
1022 debugging libraries as they are loaded. The default is not to
1023 perform such checks.
1027 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1029 ** The commands attached to a breakpoint can be set by assigning to
1030 the breakpoint's "commands" field.
1032 ** gdb.execute can now execute multi-line gdb commands.
1034 ** The new functions gdb.convenience_variable and
1035 gdb.set_convenience_variable can be used to get and set the value
1036 of convenience variables.
1038 ** A gdb.Parameter will no longer print the "set" help text on an
1039 ordinary "set"; instead by default a "set" will be silent unless
1040 the get_set_string method returns a non-empty string.
1044 RiscV ELF riscv*-*-elf
1046 * Removed targets and native configurations
1048 m88k running OpenBSD m88*-*-openbsd*
1049 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1050 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1051 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1053 * Aarch64/Linux hardware watchpoints improvements
1055 Hardware watchpoints on unaligned addresses are now properly
1056 supported when running Linux kernel 4.10 or higher: read and access
1057 watchpoints are no longer spuriously missed, and all watchpoints
1058 lengths between 1 and 8 bytes are supported. On older kernels,
1059 watchpoints set on unaligned addresses are no longer missed, with
1060 the tradeoff that there is a possibility of false hits being
1065 --enable-codesign=CERT
1066 This can be used to invoke "codesign -s CERT" after building gdb.
1067 This option is useful on macOS, where code signing is required for
1068 gdb to work properly.
1070 --disable-gdbcli has been removed
1071 This is now silently accepted, but does nothing.
1073 *** Changes in GDB 8.1
1075 * GDB now supports dynamically creating arbitrary register groups specified
1076 in XML target descriptions. This allows for finer grain grouping of
1077 registers on systems with a large amount of registers.
1079 * The 'ptype' command now accepts a '/o' flag, which prints the
1080 offsets and sizes of fields in a struct, like the pahole(1) tool.
1082 * New "--readnever" command line option instructs GDB to not read each
1083 symbol file's symbolic debug information. This makes startup faster
1084 but at the expense of not being able to perform symbolic debugging.
1085 This option is intended for use cases where symbolic debugging will
1086 not be used, e.g., when you only need to dump the debuggee's core.
1088 * GDB now uses the GNU MPFR library, if available, to emulate target
1089 floating-point arithmetic during expression evaluation when the target
1090 uses different floating-point formats than the host. At least version
1091 3.1 of GNU MPFR is required.
1093 * GDB now supports access to the guarded-storage-control registers and the
1094 software-based guarded-storage broadcast control registers on IBM z14.
1096 * On Unix systems, GDB now supports transmitting environment variables
1097 that are to be set or unset to GDBserver. These variables will
1098 affect the environment to be passed to the remote inferior.
1100 To inform GDB of environment variables that are to be transmitted to
1101 GDBserver, use the "set environment" command. Only user set
1102 environment variables are sent to GDBserver.
1104 To inform GDB of environment variables that are to be unset before
1105 the remote inferior is started by the GDBserver, use the "unset
1106 environment" command.
1108 * Completion improvements
1110 ** GDB can now complete function parameters in linespecs and
1111 explicit locations without quoting. When setting breakpoints,
1112 quoting around functions names to help with TAB-completion is
1113 generally no longer necessary. For example, this now completes
1116 (gdb) b function(in[TAB]
1117 (gdb) b function(int)
1119 Related, GDB is no longer confused with completing functions in
1120 C++ anonymous namespaces:
1123 (gdb) b (anonymous namespace)::[TAB][TAB]
1124 (anonymous namespace)::a_function()
1125 (anonymous namespace)::b_function()
1127 ** GDB now has much improved linespec and explicit locations TAB
1128 completion support, that better understands what you're
1129 completing and offers better suggestions. For example, GDB no
1130 longer offers data symbols as possible completions when you're
1131 setting a breakpoint.
1133 ** GDB now TAB-completes label symbol names.
1135 ** The "complete" command now mimics TAB completion accurately.
1137 * New command line options (gcore)
1140 Dump all memory mappings.
1142 * Breakpoints on C++ functions are now set on all scopes by default
1144 By default, breakpoints on functions/methods are now interpreted as
1145 specifying all functions with the given name ignoring missing
1146 leading scopes (namespaces and classes).
1148 For example, assuming a C++ program with symbols named:
1153 both commands "break func()" and "break B::func()" set a breakpoint
1156 You can use the new flag "-qualified" to override this. This makes
1157 GDB interpret the specified function name as a complete
1158 fully-qualified name instead. For example, using the same C++
1159 program, the "break -q B::func" command sets a breakpoint on
1160 "B::func", only. A parameter has been added to the Python
1161 gdb.Breakpoint constructor to achieve the same result when creating
1162 a breakpoint from Python.
1164 * Breakpoints on functions marked with C++ ABI tags
1166 GDB can now set breakpoints on functions marked with C++ ABI tags
1167 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1168 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1170 Functions with a C++11 abi tag are demangled/displayed like this:
1172 function[abi:cxx11](int)
1175 You can now set a breakpoint on such functions simply as if they had
1178 (gdb) b function(int)
1180 Or if you need to disambiguate between tags, like:
1182 (gdb) b function[abi:other_tag](int)
1184 Tab completion was adjusted accordingly as well.
1188 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1189 gdb.new_thread are emitted. See the manual for further
1190 description of these.
1192 ** A new function, "gdb.rbreak" has been added to the Python API.
1193 This function allows the setting of a large number of breakpoints
1194 via a regex pattern in Python. See the manual for further details.
1196 ** Python breakpoints can now accept explicit locations. See the
1197 manual for a further description of this feature.
1200 * New features in the GDB remote stub, GDBserver
1202 ** GDBserver is now able to start inferior processes with a
1203 specified initial working directory.
1205 The user can set the desired working directory to be used from
1206 GDB using the new "set cwd" command.
1208 ** New "--selftest" command line option runs some GDBserver self
1209 tests. These self tests are disabled in releases.
1211 ** On Unix systems, GDBserver now does globbing expansion and variable
1212 substitution in inferior command line arguments.
1214 This is done by starting inferiors using a shell, like GDB does.
1215 See "set startup-with-shell" in the user manual for how to disable
1216 this from GDB when using "target extended-remote". When using
1217 "target remote", you can disable the startup with shell by using the
1218 new "--no-startup-with-shell" GDBserver command line option.
1220 ** On Unix systems, GDBserver now supports receiving environment
1221 variables that are to be set or unset from GDB. These variables
1222 will affect the environment to be passed to the inferior.
1224 * When catching an Ada exception raised with a message, GDB now prints
1225 the message in the catchpoint hit notification. In GDB/MI mode, that
1226 information is provided as an extra field named "exception-message"
1227 in the *stopped notification.
1229 * Trait objects can now be inspected When debugging Rust code. This
1230 requires compiler support which will appear in Rust 1.24.
1232 * New remote packets
1234 QEnvironmentHexEncoded
1235 Inform GDBserver of an environment variable that is to be passed to
1236 the inferior when starting it.
1239 Inform GDBserver of an environment variable that is to be unset
1240 before starting the remote inferior.
1243 Inform GDBserver that the environment should be reset (i.e.,
1244 user-set environment variables should be unset).
1247 Indicates whether the inferior must be started with a shell or not.
1250 Tell GDBserver that the inferior to be started should use a specific
1253 * The "maintenance print c-tdesc" command now takes an optional
1254 argument which is the file name of XML target description.
1256 * The "maintenance selftest" command now takes an optional argument to
1257 filter the tests to be run.
1259 * The "enable", and "disable" commands now accept a range of
1260 breakpoint locations, e.g. "enable 1.3-5".
1265 Set and show the current working directory for the inferior.
1267 set|show compile-gcc
1268 Set and show compilation command used for compiling and injecting code
1269 with the 'compile' commands.
1271 set debug separate-debug-file
1272 show debug separate-debug-file
1273 Control the display of debug output about separate debug file search.
1275 set dump-excluded-mappings
1276 show dump-excluded-mappings
1277 Control whether mappings marked with the VM_DONTDUMP flag should be
1278 dumped when generating a core file.
1280 maint info selftests
1281 List the registered selftests.
1284 Start the debugged program stopping at the first instruction.
1287 Control display of debugging messages related to OpenRISC targets.
1289 set|show print type nested-type-limit
1290 Set and show the limit of nesting level for nested types that the
1291 type printer will show.
1293 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1296 * Safer/improved support for debugging with no debug info
1298 GDB no longer assumes functions with no debug information return
1301 This means that GDB now refuses to call such functions unless you
1302 tell it the function's type, by either casting the call to the
1303 declared return type, or by casting the function to a function
1304 pointer of the right type, and calling that:
1306 (gdb) p getenv ("PATH")
1307 'getenv' has unknown return type; cast the call to its declared return type
1308 (gdb) p (char *) getenv ("PATH")
1309 $1 = 0x7fffffffe "/usr/local/bin:/"...
1310 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1311 $2 = 0x7fffffffe "/usr/local/bin:/"...
1313 Similarly, GDB no longer assumes that global variables with no debug
1314 info have type 'int', and refuses to print the variable's value
1315 unless you tell it the variable's type:
1318 'var' has unknown type; cast it to its declared type
1322 * New native configurations
1324 FreeBSD/aarch64 aarch64*-*-freebsd*
1325 FreeBSD/arm arm*-*-freebsd*
1329 FreeBSD/aarch64 aarch64*-*-freebsd*
1330 FreeBSD/arm arm*-*-freebsd*
1331 OpenRISC ELF or1k*-*-elf
1333 * Removed targets and native configurations
1335 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1337 *** Changes in GDB 8.0
1339 * GDB now supports access to the PKU register on GNU/Linux. The register is
1340 added by the Memory Protection Keys for Userspace feature which will be
1341 available in future Intel CPUs.
1343 * GDB now supports C++11 rvalue references.
1347 ** New functions to start, stop and access a running btrace recording.
1348 ** Rvalue references are now supported in gdb.Type.
1350 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1353 * Building GDB and GDBserver now requires a C++11 compiler.
1355 For example, GCC 4.8 or later.
1357 It is no longer possible to build GDB or GDBserver with a C
1358 compiler. The --disable-build-with-cxx configure option has been
1361 * Building GDB and GDBserver now requires GNU make >= 3.81.
1363 It is no longer supported to build GDB or GDBserver with another
1364 implementation of the make program or an earlier version of GNU make.
1366 * Native debugging on MS-Windows supports command-line redirection
1368 Command-line arguments used for starting programs on MS-Windows can
1369 now include redirection symbols supported by native Windows shells,
1370 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1371 as "run", "start", and "set args", as well as the corresponding MI
1374 * Support for thread names on MS-Windows.
1376 GDB now catches and handles the special exception that programs
1377 running on MS-Windows use to assign names to threads in the
1380 * Support for Java programs compiled with gcj has been removed.
1382 * User commands now accept an unlimited number of arguments.
1383 Previously, only up to 10 was accepted.
1385 * The "eval" command now expands user-defined command arguments.
1387 This makes it easier to process a variable number of arguments:
1392 eval "print $arg%d", $i
1397 * Target descriptions can now describe registers for sparc32 and sparc64.
1399 * GDB now supports DWARF version 5 (debug information format).
1400 Its .debug_names index is not yet supported.
1402 * New native configurations
1404 FreeBSD/mips mips*-*-freebsd
1408 Synopsys ARC arc*-*-elf32
1409 FreeBSD/mips mips*-*-freebsd
1411 * Removed targets and native configurations
1413 Alpha running FreeBSD alpha*-*-freebsd*
1414 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1419 Erases all the flash memory regions reported by the target.
1421 maint print arc arc-instruction address
1422 Print internal disassembler information about instruction at a given address.
1426 set disassembler-options
1427 show disassembler-options
1428 Controls the passing of target specific information to the disassembler.
1429 If it is necessary to specify more than one disassembler option then
1430 multiple options can be placed together into a comma separated list.
1431 The default value is the empty string. Currently, the only supported
1432 targets are ARM, PowerPC and S/390.
1437 Erases all the flash memory regions reported by the target. This is
1438 equivalent to the CLI command flash-erase.
1440 -file-list-shared-libraries
1441 List the shared libraries in the program. This is
1442 equivalent to the CLI command "info shared".
1445 Catchpoints stopping the program when Ada exceptions are
1446 handled. This is equivalent to the CLI command "catch handlers".
1448 *** Changes in GDB 7.12
1450 * GDB and GDBserver now build with a C++ compiler by default.
1452 The --enable-build-with-cxx configure option is now enabled by
1453 default. One must now explicitly configure with
1454 --disable-build-with-cxx in order to build with a C compiler. This
1455 option will be removed in a future release.
1457 * GDBserver now supports recording btrace without maintaining an active
1460 * GDB now supports a negative repeat count in the 'x' command to examine
1461 memory backward from the given address. For example:
1464 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1465 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1466 (gdb) x/-5i 0x0000000000400580
1467 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1468 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1469 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1470 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1471 0x40057b <main(int, char**)+25>:
1472 callq 0x400536 <Func1(int, char const*)>
1474 * Fortran: Support structures with fields of dynamic types and
1475 arrays of dynamic types.
1477 * The symbol dumping maintenance commands have new syntax.
1478 maint print symbols [-pc address] [--] [filename]
1479 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1480 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1481 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1482 maint print msymbols [-objfile objfile] [--] [filename]
1484 * GDB now supports multibit bitfields and enums in target register
1487 * New Python-based convenience function $_as_string(val), which returns
1488 the textual representation of a value. This function is especially
1489 useful to obtain the text label of an enum value.
1491 * Intel MPX bound violation handling.
1493 Segmentation faults caused by a Intel MPX boundary violation
1494 now display the kind of violation (upper or lower), the memory
1495 address accessed and the memory bounds, along with the usual
1496 signal received and code location.
1500 Program received signal SIGSEGV, Segmentation fault
1501 Upper bound violation while accessing address 0x7fffffffc3b3
1502 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1503 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1505 * Rust language support.
1506 GDB now supports debugging programs written in the Rust programming
1507 language. See https://www.rust-lang.org/ for more information about
1510 * Support for running interpreters on specified input/output devices
1512 GDB now supports a new mechanism that allows frontends to provide
1513 fully featured GDB console views, as a better alternative to
1514 building such views on top of the "-interpreter-exec console"
1515 command. See the new "new-ui" command below. With that command,
1516 frontends can now start GDB in the traditional command-line mode
1517 running in an embedded terminal emulator widget, and create a
1518 separate MI interpreter running on a specified i/o device. In this
1519 way, GDB handles line editing, history, tab completion, etc. in the
1520 console all by itself, and the GUI uses the separate MI interpreter
1521 for its own control and synchronization, invisible to the command
1524 * The "catch syscall" command catches groups of related syscalls.
1526 The "catch syscall" command now supports catching a group of related
1527 syscalls using the 'group:' or 'g:' prefix.
1532 skip -gfile file-glob-pattern
1533 skip -function function
1534 skip -rfunction regular-expression
1535 A generalized form of the skip command, with new support for
1536 glob-style file names and regular expressions for function names.
1537 Additionally, a file spec and a function spec may now be combined.
1539 maint info line-table REGEXP
1540 Display the contents of GDB's internal line table data structure.
1543 Run any GDB unit tests that were compiled in.
1546 Start a new user interface instance running INTERP as interpreter,
1547 using the TTY file for input/output.
1551 ** gdb.Breakpoint objects have a new attribute "pending", which
1552 indicates whether the breakpoint is pending.
1553 ** Three new breakpoint-related events have been added:
1554 gdb.breakpoint_created, gdb.breakpoint_modified, and
1555 gdb.breakpoint_deleted.
1557 signal-event EVENTID
1558 Signal ("set") the given MS-Windows event object. This is used in
1559 conjunction with the Windows JIT debugging (AeDebug) support, where
1560 the OS suspends a crashing process until a debugger can attach to
1561 it. Resuming the crashing process, in order to debug it, is done by
1562 signalling an event.
1564 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1565 was added in GDBserver, including JIT compiling fast tracepoint's
1566 conditional expression bytecode into native code.
1568 * Support for various remote target protocols and ROM monitors has
1571 target m32rsdi Remote M32R debugging over SDI
1572 target mips MIPS remote debugging protocol
1573 target pmon PMON ROM monitor
1574 target ddb NEC's DDB variant of PMON for Vr4300
1575 target rockhopper NEC RockHopper variant of PMON
1576 target lsi LSI variant of PMO
1578 * Support for tracepoints and fast tracepoints on powerpc-linux,
1579 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1580 including JIT compiling fast tracepoint's conditional expression
1581 bytecode into native code.
1583 * MI async record =record-started now includes the method and format used for
1584 recording. For example:
1586 =record-started,thread-group="i1",method="btrace",format="bts"
1588 * MI async record =thread-selected now includes the frame field. For example:
1590 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1594 Andes NDS32 nds32*-*-elf
1596 *** Changes in GDB 7.11
1598 * GDB now supports debugging kernel-based threads on FreeBSD.
1600 * Per-inferior thread numbers
1602 Thread numbers are now per inferior instead of global. If you're
1603 debugging multiple inferiors, GDB displays thread IDs using a
1604 qualified INF_NUM.THR_NUM form. For example:
1608 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1609 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1610 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1611 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1613 As consequence, thread numbers as visible in the $_thread
1614 convenience variable and in Python's InferiorThread.num attribute
1615 are no longer unique between inferiors.
1617 GDB now maintains a second thread ID per thread, referred to as the
1618 global thread ID, which is the new equivalent of thread numbers in
1619 previous releases. See also $_gthread below.
1621 For backwards compatibility, MI's thread IDs always refer to global
1624 * Commands that accept thread IDs now accept the qualified
1625 INF_NUM.THR_NUM form as well. For example:
1628 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1631 * In commands that accept a list of thread IDs, you can now refer to
1632 all threads of an inferior using a star wildcard. GDB accepts
1633 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1634 refer to all threads of the current inferior. For example, "info
1637 * You can use "info threads -gid" to display the global thread ID of
1640 * The new convenience variable $_gthread holds the global number of
1643 * The new convenience variable $_inferior holds the number of the
1646 * GDB now displays the ID and name of the thread that hit a breakpoint
1647 or received a signal, if your program is multi-threaded. For
1650 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1651 Thread 1 "main" received signal SIGINT, Interrupt.
1653 * Record btrace now supports non-stop mode.
1655 * Support for tracepoints on aarch64-linux was added in GDBserver.
1657 * The 'record instruction-history' command now indicates speculative execution
1658 when using the Intel Processor Trace recording format.
1660 * GDB now allows users to specify explicit locations, bypassing
1661 the linespec parser. This feature is also available to GDB/MI
1664 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1665 GDB now is able to debug both AArch64 applications and ARM applications
1668 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1669 including JIT compiling fast tracepoint's conditional expression bytecode
1672 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1674 * "info threads", "info inferiors", "info display", "info checkpoints"
1675 and "maint info program-spaces" now list the corresponding items in
1676 ascending ID order, for consistency with all other "info" commands.
1678 * In Ada, the overloads selection menu has been enhanced to display the
1679 parameter types and the return types for the matching overloaded subprograms.
1683 maint set target-non-stop (on|off|auto)
1684 maint show target-non-stop
1685 Control whether GDB targets always operate in non-stop mode even if
1686 "set non-stop" is "off". The default is "auto", meaning non-stop
1687 mode is enabled if supported by the target.
1689 maint set bfd-sharing
1690 maint show bfd-sharing
1691 Control the reuse of bfd objects.
1694 show debug bfd-cache
1695 Control display of debugging info regarding bfd caching.
1699 Control display of debugging info regarding FreeBSD threads.
1701 set remote multiprocess-extensions-packet
1702 show remote multiprocess-extensions-packet
1703 Set/show the use of the remote protocol multiprocess extensions.
1705 set remote thread-events
1706 show remote thread-events
1707 Set/show the use of thread create/exit events.
1709 set ada print-signatures on|off
1710 show ada print-signatures"
1711 Control whether parameter types and return types are displayed in overloads
1712 selection menus. It is activated (@code{on}) by default.
1716 Controls the maximum size of memory, in bytes, that GDB will
1717 allocate for value contents. Prevents incorrect programs from
1718 causing GDB to allocate overly large buffers. Default is 64k.
1720 * The "disassemble" command accepts a new modifier: /s.
1721 It prints mixed source+disassembly like /m with two differences:
1722 - disassembled instructions are now printed in program order, and
1723 - and source for all relevant files is now printed.
1724 The "/m" option is now considered deprecated: its "source-centric"
1725 output hasn't proved useful in practice.
1727 * The "record instruction-history" command accepts a new modifier: /s.
1728 It behaves exactly like /m and prints mixed source+disassembly.
1730 * The "set scheduler-locking" command supports a new mode "replay".
1731 It behaves like "off" in record mode and like "on" in replay mode.
1733 * Support for various ROM monitors has been removed:
1735 target dbug dBUG ROM monitor for Motorola ColdFire
1736 target picobug Motorola picobug monitor
1737 target dink32 DINK32 ROM monitor for PowerPC
1738 target m32r Renesas M32R/D ROM monitor
1739 target mon2000 mon2000 ROM monitor
1740 target ppcbug PPCBUG ROM monitor for PowerPC
1742 * Support for reading/writing memory and extracting values on architectures
1743 whose memory is addressable in units of any integral multiple of 8 bits.
1746 Allows to break when an Ada exception is handled.
1748 * New remote packets
1751 Indicates that an exec system call was executed.
1753 exec-events feature in qSupported
1754 The qSupported packet allows GDB to request support for exec
1755 events using the new 'gdbfeature' exec-event, and the qSupported
1756 response can contain the corresponding 'stubfeature'. Set and
1757 show commands can be used to display whether these features are enabled.
1760 Equivalent to interrupting with the ^C character, but works in
1763 thread created stop reason (T05 create:...)
1764 Indicates that the thread was just created and is stopped at entry.
1766 thread exit stop reply (w exitcode;tid)
1767 Indicates that the thread has terminated.
1770 Enables/disables thread create and exit event reporting. For
1771 example, this is used in non-stop mode when GDB stops a set of
1772 threads and synchronously waits for the their corresponding stop
1773 replies. Without exit events, if one of the threads exits, GDB
1774 would hang forever not knowing that it should no longer expect a
1775 stop for that same thread.
1778 Indicates that there are no resumed threads left in the target (all
1779 threads are stopped). The remote stub reports support for this stop
1780 reply to GDB's qSupported query.
1783 Enables/disables catching syscalls from the inferior process.
1784 The remote stub reports support for this packet to GDB's qSupported query.
1786 syscall_entry stop reason
1787 Indicates that a syscall was just called.
1789 syscall_return stop reason
1790 Indicates that a syscall just returned.
1792 * Extended-remote exec events
1794 ** GDB now has support for exec events on extended-remote Linux targets.
1795 For such targets with Linux kernels 2.5.46 and later, this enables
1796 follow-exec-mode and exec catchpoints.
1798 set remote exec-event-feature-packet
1799 show remote exec-event-feature-packet
1800 Set/show the use of the remote exec event feature.
1802 * Thread names in remote protocol
1804 The reply to qXfer:threads:read may now include a name attribute for each
1807 * Target remote mode fork and exec events
1809 ** GDB now has support for fork and exec events on target remote mode
1810 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1811 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1812 fork and exec catchpoints.
1814 * Remote syscall events
1816 ** GDB now has support for catch syscall on remote Linux targets,
1817 currently enabled on x86/x86_64 architectures.
1819 set remote catch-syscall-packet
1820 show remote catch-syscall-packet
1821 Set/show the use of the remote catch syscall feature.
1825 ** The -var-set-format command now accepts the zero-hexadecimal
1826 format. It outputs data in hexadecimal format with zero-padding on the
1831 ** gdb.InferiorThread objects have a new attribute "global_num",
1832 which refers to the thread's global thread ID. The existing
1833 "num" attribute now refers to the thread's per-inferior number.
1834 See "Per-inferior thread numbers" above.
1835 ** gdb.InferiorThread objects have a new attribute "inferior", which
1836 is the Inferior object the thread belongs to.
1838 *** Changes in GDB 7.10
1840 * Support for process record-replay and reverse debugging on aarch64*-linux*
1841 targets has been added. GDB now supports recording of A64 instruction set
1842 including advance SIMD instructions.
1844 * Support for Sun's version of the "stabs" debug file format has been removed.
1846 * GDB now honors the content of the file /proc/PID/coredump_filter
1847 (PID is the process ID) on GNU/Linux systems. This file can be used
1848 to specify the types of memory mappings that will be included in a
1849 corefile. For more information, please refer to the manual page of
1850 "core(5)". GDB also has a new command: "set use-coredump-filter
1851 on|off". It allows to set whether GDB will read the content of the
1852 /proc/PID/coredump_filter file when generating a corefile.
1854 * The "info os" command on GNU/Linux can now display information on
1856 "info os cpus" Listing of all cpus/cores on the system
1858 * GDB has two new commands: "set serial parity odd|even|none" and
1859 "show serial parity". These allows to set or show parity for the
1862 * The "info source" command now displays the producer string if it was
1863 present in the debug info. This typically includes the compiler version
1864 and may include things like its command line arguments.
1866 * The "info dll", an alias of the "info sharedlibrary" command,
1867 is now available on all platforms.
1869 * Directory names supplied to the "set sysroot" commands may be
1870 prefixed with "target:" to tell GDB to access shared libraries from
1871 the target system, be it local or remote. This replaces the prefix
1872 "remote:". The default sysroot has been changed from "" to
1873 "target:". "remote:" is automatically converted to "target:" for
1874 backward compatibility.
1876 * The system root specified by "set sysroot" will be prepended to the
1877 filename of the main executable (if reported to GDB as absolute by
1878 the operating system) when starting processes remotely, and when
1879 attaching to already-running local or remote processes.
1881 * GDB now supports automatic location and retrieval of executable
1882 files from remote targets. Remote debugging can now be initiated
1883 using only a "target remote" or "target extended-remote" command
1884 (no "set sysroot" or "file" commands are required). See "New remote
1887 * The "dump" command now supports verilog hex format.
1889 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1891 * On GNU/Linux, GDB and gdbserver are now able to access executable
1892 and shared library files without a "set sysroot" command when
1893 attaching to processes running in different mount namespaces from
1894 the debugger. This makes it possible to attach to processes in
1895 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1896 See "New remote packets" below.
1898 * The "tui reg" command now provides completion for all of the
1899 available register groups, including target specific groups.
1901 * The HISTSIZE environment variable is no longer read when determining
1902 the size of GDB's command history. GDB now instead reads the dedicated
1903 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1904 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1909 ** Memory ports can now be unbuffered.
1913 ** gdb.Objfile objects have a new attribute "username",
1914 which is the name of the objfile as specified by the user,
1915 without, for example, resolving symlinks.
1916 ** You can now write frame unwinders in Python.
1917 ** gdb.Type objects have a new method "optimized_out",
1918 returning optimized out gdb.Value instance of this type.
1919 ** gdb.Value objects have new methods "reference_value" and
1920 "const_value" which return a reference to the value and a
1921 "const" version of the value respectively.
1925 maint print symbol-cache
1926 Print the contents of the symbol cache.
1928 maint print symbol-cache-statistics
1929 Print statistics of symbol cache usage.
1931 maint flush-symbol-cache
1932 Flush the contents of the symbol cache.
1936 Start branch trace recording using Branch Trace Store (BTS) format.
1939 Evaluate expression by using the compiler and print result.
1943 Explicit commands for enabling and disabling tui mode.
1946 set mpx bound on i386 and amd64
1947 Support for bound table investigation on Intel MPX enabled applications.
1951 Start branch trace recording using Intel Processor Trace format.
1954 Print information about branch tracing internals.
1956 maint btrace packet-history
1957 Print the raw branch tracing data.
1959 maint btrace clear-packet-history
1960 Discard the stored raw branch tracing data.
1963 Discard all branch tracing data. It will be fetched and processed
1964 anew by the next "record" command.
1969 Renamed from "set debug dwarf2-die".
1970 show debug dwarf-die
1971 Renamed from "show debug dwarf2-die".
1973 set debug dwarf-read
1974 Renamed from "set debug dwarf2-read".
1975 show debug dwarf-read
1976 Renamed from "show debug dwarf2-read".
1978 maint set dwarf always-disassemble
1979 Renamed from "maint set dwarf2 always-disassemble".
1980 maint show dwarf always-disassemble
1981 Renamed from "maint show dwarf2 always-disassemble".
1983 maint set dwarf max-cache-age
1984 Renamed from "maint set dwarf2 max-cache-age".
1985 maint show dwarf max-cache-age
1986 Renamed from "maint show dwarf2 max-cache-age".
1988 set debug dwarf-line
1989 show debug dwarf-line
1990 Control display of debugging info regarding DWARF line processing.
1993 show max-completions
1994 Set the maximum number of candidates to be considered during
1995 completion. The default value is 200. This limit allows GDB
1996 to avoid generating large completion lists, the computation of
1997 which can cause the debugger to become temporarily unresponsive.
1999 set history remove-duplicates
2000 show history remove-duplicates
2001 Control the removal of duplicate history entries.
2003 maint set symbol-cache-size
2004 maint show symbol-cache-size
2005 Control the size of the symbol cache.
2007 set|show record btrace bts buffer-size
2008 Set and show the size of the ring buffer used for branch tracing in
2010 The obtained size may differ from the requested size. Use "info
2011 record" to see the obtained buffer size.
2013 set debug linux-namespaces
2014 show debug linux-namespaces
2015 Control display of debugging info regarding Linux namespaces.
2017 set|show record btrace pt buffer-size
2018 Set and show the size of the ring buffer used for branch tracing in
2019 Intel Processor Trace format.
2020 The obtained size may differ from the requested size. Use "info
2021 record" to see the obtained buffer size.
2023 maint set|show btrace pt skip-pad
2024 Set and show whether PAD packets are skipped when computing the
2027 * The command 'thread apply all' can now support new option '-ascending'
2028 to call its specified command for all threads in ascending order.
2030 * Python/Guile scripting
2032 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2033 special section named `.debug_gdb_scripts'.
2035 * New remote packets
2037 qXfer:btrace-conf:read
2038 Return the branch trace configuration for the current thread.
2040 Qbtrace-conf:bts:size
2041 Set the requested ring buffer size for branch tracing in BTS format.
2044 Enable Intel Processor Trace-based branch tracing for the current
2045 process. The remote stub reports support for this packet to GDB's
2048 Qbtrace-conf:pt:size
2049 Set the requested ring buffer size for branch tracing in Intel Processor
2053 Indicates a memory breakpoint instruction was executed, irrespective
2054 of whether it was GDB that planted the breakpoint or the breakpoint
2055 is hardcoded in the program. This is required for correct non-stop
2059 Indicates the target stopped for a hardware breakpoint. This is
2060 required for correct non-stop mode operation.
2063 Return information about files on the remote system.
2065 qXfer:exec-file:read
2066 Return the full absolute name of the file that was executed to
2067 create a process running on the remote system.
2070 Select the filesystem on which vFile: operations with filename
2071 arguments will operate. This is required for GDB to be able to
2072 access files on remote targets where the remote stub does not
2073 share a common filesystem with the inferior(s).
2076 Indicates that a fork system call was executed.
2079 Indicates that a vfork system call was executed.
2081 vforkdone stop reason
2082 Indicates that a vfork child of the specified process has executed
2083 an exec or exit, allowing the vfork parent to resume execution.
2085 fork-events and vfork-events features in qSupported
2086 The qSupported packet allows GDB to request support for fork and
2087 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2088 and the qSupported response can contain the corresponding
2089 'stubfeatures'. Set and show commands can be used to display
2090 whether these features are enabled.
2092 * Extended-remote fork events
2094 ** GDB now has support for fork events on extended-remote Linux
2095 targets. For targets with Linux kernels 2.5.60 and later, this
2096 enables follow-fork-mode and detach-on-fork for both fork and
2097 vfork, as well as fork and vfork catchpoints.
2099 * The info record command now shows the recording format and the
2100 branch tracing configuration for the current thread when using
2101 the btrace record target.
2102 For the BTS format, it shows the ring buffer size.
2104 * GDB now has support for DTrace USDT (Userland Static Defined
2105 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2107 * GDB now supports access to vector registers on S/390 GNU/Linux
2110 * Removed command line options
2112 -xdb HP-UX XDB compatibility mode.
2114 * Removed targets and native configurations
2116 HP/PA running HP-UX hppa*-*-hpux*
2117 Itanium running HP-UX ia64-*-hpux*
2119 * New configure options
2122 This configure option allows the user to build GDB with support for
2123 Intel Processor Trace (default: auto). This requires libipt.
2125 --with-libipt-prefix=PATH
2126 Specify the path to the version of libipt that GDB should use.
2127 $PATH/include should contain the intel-pt.h header and
2128 $PATH/lib should contain the libipt.so library.
2130 *** Changes in GDB 7.9.1
2134 ** Xmethods can now specify a result type.
2136 *** Changes in GDB 7.9
2138 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2142 ** You can now access frame registers from Python scripts.
2143 ** New attribute 'producer' for gdb.Symtab objects.
2144 ** gdb.Objfile objects have a new attribute "progspace",
2145 which is the gdb.Progspace object of the containing program space.
2146 ** gdb.Objfile objects have a new attribute "owner".
2147 ** gdb.Objfile objects have a new attribute "build_id",
2148 which is the build ID generated when the file was built.
2149 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2150 ** A new event "gdb.clear_objfiles" has been added, triggered when
2151 selecting a new file to debug.
2152 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2153 ** New function gdb.lookup_objfile.
2155 New events which are triggered when GDB modifies the state of the
2158 ** gdb.events.inferior_call_pre: Function call is about to be made.
2159 ** gdb.events.inferior_call_post: Function call has just been made.
2160 ** gdb.events.memory_changed: A memory location has been altered.
2161 ** gdb.events.register_changed: A register has been altered.
2163 * New Python-based convenience functions:
2165 ** $_caller_is(name [, number_of_frames])
2166 ** $_caller_matches(regexp [, number_of_frames])
2167 ** $_any_caller_is(name [, number_of_frames])
2168 ** $_any_caller_matches(regexp [, number_of_frames])
2170 * GDB now supports the compilation and injection of source code into
2171 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2172 to compile the source code to object code, and if successful, inject
2173 and execute that code within the current context of the inferior.
2174 Currently the C language is supported. The commands used to
2175 interface with this new feature are:
2177 compile code [-raw|-r] [--] [source code]
2178 compile file [-raw|-r] filename
2182 demangle [-l language] [--] name
2183 Demangle "name" in the specified language, or the current language
2184 if elided. This command is renamed from the "maint demangle" command.
2185 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2186 as "maint demangler-warning".
2188 queue-signal signal-name-or-number
2189 Queue a signal to be delivered to the thread when it is resumed.
2191 add-auto-load-scripts-directory directory
2192 Add entries to the list of directories from which to load auto-loaded
2195 maint print user-registers
2196 List all currently available "user" registers.
2198 compile code [-r|-raw] [--] [source code]
2199 Compile, inject, and execute in the inferior the executable object
2200 code produced by compiling the provided source code.
2202 compile file [-r|-raw] filename
2203 Compile and inject into the inferior the executable object code
2204 produced by compiling the source code stored in the filename
2207 * On resume, GDB now always passes the signal the program had stopped
2208 for to the thread the signal was sent to, even if the user changed
2209 threads before resuming. Previously GDB would often (but not
2210 always) deliver the signal to the thread that happens to be current
2213 * Conversely, the "signal" command now consistently delivers the
2214 requested signal to the current thread. GDB now asks for
2215 confirmation if the program had stopped for a signal and the user
2216 switched threads meanwhile.
2218 * "breakpoint always-inserted" modes "off" and "auto" merged.
2220 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2221 won't remove breakpoints from the target until all threads stop,
2222 even in non-stop mode. The "auto" mode has been removed, and "off"
2223 is now the default mode.
2227 set debug symbol-lookup
2228 show debug symbol-lookup
2229 Control display of debugging info regarding symbol lookup.
2233 ** The -list-thread-groups command outputs an exit-code field for
2234 inferiors that have exited.
2238 MIPS SDE mips*-sde*-elf*
2242 Support for these obsolete configurations has been removed.
2244 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2245 SGI Irix-5.x mips-*-irix5*
2246 SGI Irix-6.x mips-*-irix6*
2247 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2248 VAX running Ultrix vax-*-ultrix*
2250 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2251 and "assf"), have been removed. Use the "sharedlibrary" command, or
2252 its alias "share", instead.
2254 *** Changes in GDB 7.8
2256 * New command line options
2259 This is an alias for the --data-directory option.
2261 * GDB supports printing and modifying of variable length automatic arrays
2262 as specified in ISO C99.
2264 * The ARM simulator now supports instruction level tracing
2265 with or without disassembly.
2269 GDB now has support for scripting using Guile. Whether this is
2270 available is determined at configure time.
2271 Guile version 2.0 or greater is required.
2272 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2274 * New commands (for set/show, see "New options" below)
2278 Invoke CODE by passing it to the Guile interpreter.
2282 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2284 info auto-load guile-scripts [regexp]
2285 Print the list of automatically loaded Guile scripts.
2287 * The source command is now capable of sourcing Guile scripts.
2288 This feature is dependent on the debugger being built with Guile support.
2292 set print symbol-loading (off|brief|full)
2293 show print symbol-loading
2294 Control whether to print informational messages when loading symbol
2295 information for a file. The default is "full", but when debugging
2296 programs with large numbers of shared libraries the amount of output
2297 becomes less useful.
2299 set guile print-stack (none|message|full)
2300 show guile print-stack
2301 Show a stack trace when an error is encountered in a Guile script.
2303 set auto-load guile-scripts (on|off)
2304 show auto-load guile-scripts
2305 Control auto-loading of Guile script files.
2307 maint ada set ignore-descriptive-types (on|off)
2308 maint ada show ignore-descriptive-types
2309 Control whether the debugger should ignore descriptive types in Ada
2310 programs. The default is not to ignore the descriptive types. See
2311 the user manual for more details on descriptive types and the intended
2312 usage of this option.
2314 set auto-connect-native-target
2316 Control whether GDB is allowed to automatically connect to the
2317 native target for the run, attach, etc. commands when not connected
2318 to any target yet. See also "target native" below.
2320 set record btrace replay-memory-access (read-only|read-write)
2321 show record btrace replay-memory-access
2322 Control what memory accesses are allowed during replay.
2324 maint set target-async (on|off)
2325 maint show target-async
2326 This controls whether GDB targets operate in synchronous or
2327 asynchronous mode. Normally the default is asynchronous, if it is
2328 available; but this can be changed to more easily debug problems
2329 occurring only in synchronous mode.
2331 set mi-async (on|off)
2333 Control whether MI asynchronous mode is preferred. This supersedes
2334 "set target-async" of previous GDB versions.
2336 * "set target-async" is deprecated as a CLI option and is now an alias
2337 for "set mi-async" (only puts MI into async mode).
2339 * Background execution commands (e.g., "c&", "s&", etc.) are now
2340 possible ``out of the box'' if the target supports them. Previously
2341 the user would need to explicitly enable the possibility with the
2342 "set target-async on" command.
2344 * New features in the GDB remote stub, GDBserver
2346 ** New option --debug-format=option1[,option2,...] allows one to add
2347 additional text to each output. At present only timestamps
2348 are supported: --debug-format=timestamps.
2349 Timestamps can also be turned on with the
2350 "monitor set debug-format timestamps" command from GDB.
2352 * The 'record instruction-history' command now starts counting instructions
2353 at one. This also affects the instruction ranges reported by the
2354 'record function-call-history' command when given the /i modifier.
2356 * The command 'record function-call-history' supports a new modifier '/c' to
2357 indent the function names based on their call stack depth.
2358 The fields for the '/i' and '/l' modifier have been reordered.
2359 The source line range is now prefixed with 'at'.
2360 The instruction range is now prefixed with 'inst'.
2361 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2362 "record instruction-history" and "list" commands.
2364 * The ranges given as arguments to the 'record function-call-history' and
2365 'record instruction-history' commands are now inclusive.
2367 * The btrace record target now supports the 'record goto' command.
2368 For locations inside the execution trace, the back trace is computed
2369 based on the information stored in the execution trace.
2371 * The btrace record target supports limited reverse execution and replay.
2372 The target does not record data and therefore does not allow reading
2373 memory or registers.
2375 * The "catch syscall" command now works on s390*-linux* targets.
2377 * The "compare-sections" command is no longer specific to target
2378 remote. It now works with all targets.
2380 * All native targets are now consistently called "native".
2381 Consequently, the "target child", "target GNU", "target djgpp",
2382 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2383 commands have been replaced with "target native". The QNX/NTO port
2384 leaves the "procfs" target in place and adds a "native" target for
2385 consistency with other ports. The impact on users should be minimal
2386 as these commands previously either throwed an error, or were
2387 no-ops. The target's name is visible in the output of the following
2388 commands: "help target", "info target", "info files", "maint print
2391 * The "target native" command now connects to the native target. This
2392 can be used to launch native programs even when "set
2393 auto-connect-native-target" is set to off.
2395 * GDB now supports access to Intel MPX registers on GNU/Linux.
2397 * Support for Intel AVX-512 registers on GNU/Linux.
2398 Support displaying and modifying Intel AVX-512 registers
2399 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2401 * New remote packets
2403 qXfer:btrace:read's annex
2404 The qXfer:btrace:read packet supports a new annex 'delta' to read
2405 branch trace incrementally.
2409 ** Valid Python operations on gdb.Value objects representing
2410 structs/classes invoke the corresponding overloaded operators if
2412 ** New `Xmethods' feature in the Python API. Xmethods are
2413 additional methods or replacements for existing methods of a C++
2414 class. This feature is useful for those cases where a method
2415 defined in C++ source code could be inlined or optimized out by
2416 the compiler, making it unavailable to GDB.
2419 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2421 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2422 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2423 its alias "share", instead.
2425 * The commands "set remotebaud" and "show remotebaud" are no longer
2426 supported. Use "set serial baud" and "show serial baud" (respectively)
2431 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2432 target-async". The latter is left as a deprecated alias of the
2433 former for backward compatibility. If the target supports it,
2434 CLI background execution commands are now always possible by
2435 default, independently of whether the frontend stated a
2436 preference for asynchronous execution with "-gdb-set mi-async".
2437 Previously "-gdb-set target-async off" affected both MI execution
2438 commands and CLI execution commands.
2440 *** Changes in GDB 7.7
2442 * Improved support for process record-replay and reverse debugging on
2443 arm*-linux* targets. Support for thumb32 and syscall instruction
2444 recording has been added.
2446 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2448 * GDB now supports Fission DWP file format version 2.
2449 http://gcc.gnu.org/wiki/DebugFission
2451 * New convenience function "$_isvoid", to check whether an expression
2452 is void. A void expression is an expression where the type of the
2453 result is "void". For example, some convenience variables may be
2454 "void" when evaluated (e.g., "$_exitcode" before the execution of
2455 the program being debugged; or an undefined convenience variable).
2456 Another example, when calling a function whose return type is
2459 * The "maintenance print objfiles" command now takes an optional regexp.
2461 * The "catch syscall" command now works on arm*-linux* targets.
2463 * GDB now consistently shows "<not saved>" when printing values of
2464 registers the debug info indicates have not been saved in the frame
2465 and there's nowhere to retrieve them from
2466 (callee-saved/call-clobbered registers):
2471 (gdb) info registers rax
2474 Before, the former would print "<optimized out>", and the latter
2475 "*value not available*".
2477 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2482 ** Frame filters and frame decorators have been added.
2483 ** Temporary breakpoints are now supported.
2484 ** Line tables representation has been added.
2485 ** New attribute 'parent_type' for gdb.Field objects.
2486 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2487 ** New attribute 'name' for gdb.Type objects.
2491 Nios II ELF nios2*-*-elf
2492 Nios II GNU/Linux nios2*-*-linux
2493 Texas Instruments MSP430 msp430*-*-elf
2495 * Removed native configurations
2497 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2498 been removed. ELF variants of these configurations are kept supported.
2500 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2501 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2502 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2503 i[34567]86-*-openbsd3.[0-3]
2504 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2505 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2506 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2510 Like "catch throw", but catches a re-thrown exception.
2511 maint check-psymtabs
2512 Renamed from old "maint check-symtabs".
2514 Perform consistency checks on symtabs.
2515 maint expand-symtabs
2516 Expand symtabs matching an optional regexp.
2519 Display the details of GDB configure-time options.
2521 maint set|show per-command
2522 maint set|show per-command space
2523 maint set|show per-command time
2524 maint set|show per-command symtab
2525 Enable display of per-command gdb resource usage.
2527 remove-symbol-file FILENAME
2528 remove-symbol-file -a ADDRESS
2529 Remove a symbol file added via add-symbol-file. The file to remove
2530 can be identified by its filename or by an address that lies within
2531 the boundaries of this symbol file in memory.
2534 info exceptions REGEXP
2535 Display the list of Ada exceptions defined in the program being
2536 debugged. If provided, only the exceptions whose names match REGEXP
2541 set debug symfile off|on
2543 Control display of debugging info regarding reading symbol files and
2544 symbol tables within those files
2546 set print raw frame-arguments
2547 show print raw frame-arguments
2548 Set/show whether to print frame arguments in raw mode,
2549 disregarding any defined pretty-printers.
2551 set remote trace-status-packet
2552 show remote trace-status-packet
2553 Set/show the use of remote protocol qTStatus packet.
2557 Control display of debugging messages related to Nios II targets.
2561 Control whether target-assisted range stepping is enabled.
2563 set startup-with-shell
2564 show startup-with-shell
2565 Specifies whether Unix child processes are started via a shell or
2570 Use the target memory cache for accesses to the code segment. This
2571 improves performance of remote debugging (particularly disassembly).
2573 * You can now use a literal value 'unlimited' for options that
2574 interpret 0 or -1 as meaning "unlimited". E.g., "set
2575 trace-buffer-size unlimited" is now an alias for "set
2576 trace-buffer-size -1" and "set height unlimited" is now an alias for
2579 * The "set debug symtab-create" debugging option of GDB has been changed to
2580 accept a verbosity level. 0 means "off", 1 provides basic debugging
2581 output, and values of 2 or greater provides more verbose output.
2583 * New command-line options
2585 Display the details of GDB configure-time options.
2587 * The command 'tsave' can now support new option '-ctf' to save trace
2588 buffer in Common Trace Format.
2590 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2593 * GDB now implements the C++ 'typeid' operator.
2595 * The new convenience variable $_exception holds the exception being
2596 thrown or caught at an exception-related catchpoint.
2598 * The exception-related catchpoints, like "catch throw", now accept a
2599 regular expression which can be used to filter exceptions by type.
2601 * The new convenience variable $_exitsignal is automatically set to
2602 the terminating signal number when the program being debugged dies
2603 due to an uncaught signal.
2607 ** All MI commands now accept an optional "--language" option.
2608 Support for this feature can be verified by using the "-list-features"
2609 command, which should contain "language-option".
2611 ** The new command -info-gdb-mi-command allows the user to determine
2612 whether a GDB/MI command is supported or not.
2614 ** The "^error" result record returned when trying to execute an undefined
2615 GDB/MI command now provides a variable named "code" whose content is the
2616 "undefined-command" error code. Support for this feature can be verified
2617 by using the "-list-features" command, which should contain
2618 "undefined-command-error-code".
2620 ** The -trace-save MI command can optionally save trace buffer in Common
2623 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2625 ** The command -data-list-register-values now accepts an optional
2626 "--skip-unavailable" option. When used, only the available registers
2629 ** The new command -trace-frame-collected dumps collected variables,
2630 computed expressions, tvars, memory and registers in a traceframe.
2632 ** The commands -stack-list-locals, -stack-list-arguments and
2633 -stack-list-variables now accept an option "--skip-unavailable".
2634 When used, only the available locals or arguments are displayed.
2636 ** The -exec-run command now accepts an optional "--start" option.
2637 When used, the command follows the same semantics as the "start"
2638 command, stopping the program's execution at the start of its
2639 main subprogram. Support for this feature can be verified using
2640 the "-list-features" command, which should contain
2641 "exec-run-start-option".
2643 ** The new commands -catch-assert and -catch-exceptions insert
2644 catchpoints stopping the program when Ada exceptions are raised.
2646 ** The new command -info-ada-exceptions provides the equivalent of
2647 the new "info exceptions" command.
2649 * New system-wide configuration scripts
2650 A GDB installation now provides scripts suitable for use as system-wide
2651 configuration scripts for the following systems:
2655 * GDB now supports target-assigned range stepping with remote targets.
2656 This improves the performance of stepping source lines by reducing
2657 the number of control packets from/to GDB. See "New remote packets"
2660 * GDB now understands the element 'tvar' in the XML traceframe info.
2661 It has the id of the collected trace state variables.
2663 * On S/390 targets that provide the transactional-execution feature,
2664 the program interruption transaction diagnostic block (TDB) is now
2665 represented as a number of additional "registers" in GDB.
2667 * New remote packets
2671 The vCont packet supports a new 'r' action, that tells the remote
2672 stub to step through an address range itself, without GDB
2673 involvemement at each single-step.
2675 qXfer:libraries-svr4:read's annex
2676 The previously unused annex of the qXfer:libraries-svr4:read packet
2677 is now used to support passing an argument list. The remote stub
2678 reports support for this argument list to GDB's qSupported query.
2679 The defined arguments are "start" and "prev", used to reduce work
2680 necessary for library list updating, resulting in significant
2683 * New features in the GDB remote stub, GDBserver
2685 ** GDBserver now supports target-assisted range stepping. Currently
2686 enabled on x86/x86_64 GNU/Linux targets.
2688 ** GDBserver now adds element 'tvar' in the XML in the reply to
2689 'qXfer:traceframe-info:read'. It has the id of the collected
2690 trace state variables.
2692 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2695 * New 'z' formatter for printing and examining memory, this displays the
2696 value as hexadecimal zero padded on the left to the size of the type.
2698 * GDB can now use Windows x64 unwinding data.
2700 * The "set remotebaud" command has been replaced by "set serial baud".
2701 Similarly, "show remotebaud" has been replaced by "show serial baud".
2702 The "set remotebaud" and "show remotebaud" commands are still available
2703 to provide backward compatibility with older versions of GDB.
2705 *** Changes in GDB 7.6
2707 * Target record has been renamed to record-full.
2708 Record/replay is now enabled with the "record full" command.
2709 This also affects settings that are associated with full record/replay
2710 that have been moved from "set/show record" to "set/show record full":
2712 set|show record full insn-number-max
2713 set|show record full stop-at-limit
2714 set|show record full memory-query
2716 * A new record target "record-btrace" has been added. The new target
2717 uses hardware support to record the control-flow of a process. It
2718 does not support replaying the execution, but it implements the
2719 below new commands for investigating the recorded execution log.
2720 This new recording method can be enabled using:
2724 The "record-btrace" target is only available on Intel Atom processors
2725 and requires a Linux kernel 2.6.32 or later.
2727 * Two new commands have been added for record/replay to give information
2728 about the recorded execution without having to replay the execution.
2729 The commands are only supported by "record btrace".
2731 record instruction-history prints the execution history at
2732 instruction granularity
2734 record function-call-history prints the execution history at
2735 function granularity
2737 * New native configurations
2739 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2740 FreeBSD/powerpc powerpc*-*-freebsd
2741 x86_64/Cygwin x86_64-*-cygwin*
2742 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2746 ARM AArch64 aarch64*-*-elf
2747 ARM AArch64 GNU/Linux aarch64*-*-linux
2748 Lynx 178 PowerPC powerpc-*-lynx*178
2749 x86_64/Cygwin x86_64-*-cygwin*
2750 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2752 * If the configured location of system.gdbinit file (as given by the
2753 --with-system-gdbinit option at configure time) is in the
2754 data-directory (as specified by --with-gdb-datadir at configure
2755 time) or in one of its subdirectories, then GDB will look for the
2756 system-wide init file in the directory specified by the
2757 --data-directory command-line option.
2759 * New command line options:
2761 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2762 other initialization files, unlike -nx which disables all of them.
2764 * Removed command line options
2766 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2769 * The 'ptype' and 'whatis' commands now accept an argument to control
2772 * 'info proc' now works on some core files.
2776 ** Vectors can be created with gdb.Type.vector.
2778 ** Python's atexit.register now works in GDB.
2780 ** Types can be pretty-printed via a Python API.
2782 ** Python 3 is now supported (in addition to Python 2.4 or later)
2784 ** New class gdb.Architecture exposes GDB's internal representation
2785 of architecture in the Python API.
2787 ** New method Frame.architecture returns the gdb.Architecture object
2788 corresponding to the frame's architecture.
2790 * New Python-based convenience functions:
2792 ** $_memeq(buf1, buf2, length)
2793 ** $_streq(str1, str2)
2795 ** $_regex(str, regex)
2797 * The 'cd' command now defaults to using '~' (the home directory) if not
2800 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2801 default for GCC since November 2000.
2803 * The command 'forward-search' can now be abbreviated as 'fo'.
2805 * The command 'info tracepoints' can now display 'installed on target'
2806 or 'not installed on target' for each non-pending location of tracepoint.
2808 * New configure options
2810 --enable-libmcheck/--disable-libmcheck
2811 By default, development versions are built with -lmcheck on hosts
2812 that support it, in order to help track memory corruption issues.
2813 Release versions, on the other hand, are built without -lmcheck
2814 by default. The --enable-libmcheck/--disable-libmcheck configure
2815 options allow the user to override that default.
2816 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2817 This configure option allows the user to build GDB with
2818 libbabeltrace using which GDB can read Common Trace Format data.
2820 * New commands (for set/show, see "New options" below)
2823 Catch signals. This is similar to "handle", but allows commands and
2824 conditions to be attached.
2827 List the BFDs known to GDB.
2829 python-interactive [command]
2831 Start a Python interactive prompt, or evaluate the optional command
2832 and print the result of expressions.
2835 "py" is a new alias for "python".
2837 enable type-printer [name]...
2838 disable type-printer [name]...
2839 Enable or disable type printers.
2843 ** For the Renesas Super-H architecture, the "regs" command has been removed
2844 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2849 set print type methods (on|off)
2850 show print type methods
2851 Control whether method declarations are displayed by "ptype".
2852 The default is to show them.
2854 set print type typedefs (on|off)
2855 show print type typedefs
2856 Control whether typedef definitions are displayed by "ptype".
2857 The default is to show them.
2859 set filename-display basename|relative|absolute
2860 show filename-display
2861 Control the way in which filenames is displayed.
2862 The default is "relative", which preserves previous behavior.
2864 set trace-buffer-size
2865 show trace-buffer-size
2866 Request target to change the size of trace buffer.
2868 set remote trace-buffer-size-packet auto|on|off
2869 show remote trace-buffer-size-packet
2870 Control the use of the remote protocol `QTBuffer:size' packet.
2874 Control display of debugging messages related to ARM AArch64.
2877 set debug coff-pe-read
2878 show debug coff-pe-read
2879 Control display of debugging messages related to reading of COFF/PE
2884 Control display of debugging messages related to Mach-O symbols
2887 set debug notification
2888 show debug notification
2889 Control display of debugging info for async remote notification.
2893 ** Command parameter changes are now notified using new async record
2894 "=cmd-param-changed".
2895 ** Trace frame changes caused by command "tfind" are now notified using
2896 new async record "=traceframe-changed".
2897 ** The creation, deletion and modification of trace state variables
2898 are now notified using new async records "=tsv-created",
2899 "=tsv-deleted" and "=tsv-modified".
2900 ** The start and stop of process record are now notified using new
2901 async record "=record-started" and "=record-stopped".
2902 ** Memory changes are now notified using new async record
2904 ** The data-disassemble command response will include a "fullname" field
2905 containing the absolute file name when source has been requested.
2906 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2907 command, to allow pattern filling of memory areas.
2908 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2909 library load/unload events.
2910 ** The response to breakpoint commands and breakpoint async records
2911 includes an "installed" field containing a boolean state about each
2912 non-pending tracepoint location is whether installed on target or not.
2913 ** Output of the "-trace-status" command includes a "trace-file" field
2914 containing the name of the trace file being examined. This field is
2915 optional, and only present when examining a trace file.
2916 ** The "fullname" field is now always present along with the "file" field,
2917 even if the file cannot be found by GDB.
2919 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2920 You must have the LZMA library available when configuring GDB for this
2921 feature to be enabled. For more information, see:
2922 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2924 * New remote packets
2927 Set the size of trace buffer. The remote stub reports support for this
2928 packet to gdb's qSupported query.
2931 Enable Branch Trace Store (BTS)-based branch tracing for the current
2932 thread. The remote stub reports support for this packet to gdb's
2936 Disable branch tracing for the current thread. The remote stub reports
2937 support for this packet to gdb's qSupported query.
2940 Read the traced branches for the current thread. The remote stub
2941 reports support for this packet to gdb's qSupported query.
2943 *** Changes in GDB 7.5
2945 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2946 for more x32 ABI info.
2948 * GDB now supports access to MIPS DSP registers on Linux targets.
2950 * GDB now supports debugging microMIPS binaries.
2952 * The "info os" command on GNU/Linux can now display information on
2953 several new classes of objects managed by the operating system:
2954 "info os procgroups" lists process groups
2955 "info os files" lists file descriptors
2956 "info os sockets" lists internet-domain sockets
2957 "info os shm" lists shared-memory regions
2958 "info os semaphores" lists semaphores
2959 "info os msg" lists message queues
2960 "info os modules" lists loaded kernel modules
2962 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2963 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2964 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2965 options and inspect the probe arguments using the new $_probe_arg family
2966 of convenience variables. You can obtain more information about SystemTap
2967 in <http://sourceware.org/systemtap/>.
2969 * GDB now supports reversible debugging on ARM, it allows you to
2970 debug basic ARM and THUMB instructions, and provides
2971 record/replay support.
2973 * The option "symbol-reloading" has been deleted as it is no longer used.
2977 ** GDB commands implemented in Python can now be put in command class
2980 ** The "maint set python print-stack on|off" is now deleted.
2982 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2983 apply "flag enum"-style pretty-printing to any enum.
2985 ** gdb.lookup_symbol can now work when there is no current frame.
2987 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2988 the source at which the symbol was defined.
2990 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2991 method 'value'. The former indicates whether the symbol needs a
2992 frame in order to compute its value, and the latter computes the
2995 ** A new method 'referenced_value' on gdb.Value objects which can
2996 dereference pointer as well as C++ reference values.
2998 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2999 which return the global and static blocks (as gdb.Block objects),
3000 of the underlying symbol table, respectively.
3002 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3003 object associated with a PC value.
3005 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3006 of the address range occupied by code for the current source line.
3008 * Go language support.
3009 GDB now supports debugging programs written in the Go programming
3012 * GDBserver now supports stdio connections.
3013 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3015 * The binary "gdbtui" can no longer be built or installed.
3016 Use "gdb -tui" instead.
3018 * GDB will now print "flag" enums specially. A flag enum is one where
3019 all the enumerator values have no bits in common when pairwise
3020 "and"ed. When printing a value whose type is a flag enum, GDB will
3021 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3022 (gdb) print (enum E) 3
3025 * The filename part of a linespec will now match trailing components
3026 of a source file name. For example, "break gcc/expr.c:1000" will
3027 now set a breakpoint in build/gcc/expr.c, but not
3028 build/libcpp/expr.c.
3030 * The "info proc" and "generate-core-file" commands will now also
3031 work on remote targets connected to GDBserver on Linux.
3033 * The command "info catch" has been removed. It has been disabled
3034 since December 2007.
3036 * The "catch exception" and "catch assert" commands now accept
3037 a condition at the end of the command, much like the "break"
3038 command does. For instance:
3040 (gdb) catch exception Constraint_Error if Barrier = True
3042 Previously, it was possible to add a condition to such catchpoints,
3043 but it had to be done as a second step, after the catchpoint had been
3044 created, using the "condition" command.
3046 * The "info static-tracepoint-marker" command will now also work on
3047 native Linux targets with in-process agent.
3049 * GDB can now set breakpoints on inlined functions.
3051 * The .gdb_index section has been updated to include symbols for
3052 inlined functions. GDB will ignore older .gdb_index sections by
3053 default, which could cause symbol files to be loaded more slowly
3054 until their .gdb_index sections can be recreated. The new command
3055 "set use-deprecated-index-sections on" will cause GDB to use any older
3056 .gdb_index sections it finds. This will restore performance, but the
3057 ability to set breakpoints on inlined functions will be lost in symbol
3058 files with older .gdb_index sections.
3060 The .gdb_index section has also been updated to record more information
3061 about each symbol. This speeds up the "info variables", "info functions"
3062 and "info types" commands when used with programs having the .gdb_index
3063 section, as well as speeding up debugging with shared libraries using
3064 the .gdb_index section.
3066 * Ada support for GDB/MI Variable Objects has been added.
3068 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3073 ** New command -info-os is the MI equivalent of "info os".
3075 ** Output logs ("set logging" and related) now include MI output.
3079 ** "set use-deprecated-index-sections on|off"
3080 "show use-deprecated-index-sections on|off"
3081 Controls the use of deprecated .gdb_index sections.
3083 ** "catch load" and "catch unload" can be used to stop when a shared
3084 library is loaded or unloaded, respectively.
3086 ** "enable count" can be used to auto-disable a breakpoint after
3089 ** "info vtbl" can be used to show the virtual method tables for
3090 C++ and Java objects.
3092 ** "explore" and its sub commands "explore value" and "explore type"
3093 can be used to recursively explore values and types of
3094 expressions. These commands are available only if GDB is
3095 configured with '--with-python'.
3097 ** "info auto-load" shows status of all kinds of auto-loaded files,
3098 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3099 sequences of commands files, "info auto-load python-scripts"
3100 shows status of auto-loading Python script files,
3101 "info auto-load local-gdbinit" shows status of loading init file
3102 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3103 status of inferior specific thread debugging shared library loading.
3105 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3106 and "show auto-load-scripts" commands have been deprecated, use their
3107 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3108 and "show auto-load python-scripts" counterparts instead.
3110 ** "dprintf location,format,args..." creates a dynamic printf, which
3111 is basically a breakpoint that does a printf and immediately
3112 resumes your program's execution, so it is like a printf that you
3113 can insert dynamically at runtime instead of at compiletime.
3115 ** "set print symbol"
3117 Controls whether GDB attempts to display the symbol, if any,
3118 corresponding to addresses it prints. This defaults to "on", but
3119 you can set it to "off" to restore GDB's previous behavior.
3121 * Deprecated commands
3123 ** For the Renesas Super-H architecture, the "regs" command has been
3124 deprecated, and "info all-registers" should be used instead.
3128 Renesas RL78 rl78-*-elf
3129 HP OpenVMS ia64 ia64-hp-openvms*
3131 * GDBserver supports evaluation of breakpoint conditions. When
3132 support is advertised by GDBserver, GDB may be told to send the
3133 breakpoint conditions in bytecode form to GDBserver. GDBserver
3134 will only report the breakpoint trigger to GDB when its condition
3139 set mips compression
3140 show mips compression
3141 Select the compressed ISA encoding used in functions that have no symbol
3142 information available. The encoding can be set to either of:
3145 and is updated automatically from ELF file flags if available.
3147 set breakpoint condition-evaluation
3148 show breakpoint condition-evaluation
3149 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3150 GDBserver ("target"). Default option "auto" chooses the most efficient
3152 This option can improve debugger efficiency depending on the speed of the
3156 Disable auto-loading globally.
3159 Show auto-loading setting of all kinds of auto-loaded files.
3161 set auto-load gdb-scripts on|off
3162 show auto-load gdb-scripts
3163 Control auto-loading of GDB canned sequences of commands files.
3165 set auto-load python-scripts on|off
3166 show auto-load python-scripts
3167 Control auto-loading of Python script files.
3169 set auto-load local-gdbinit on|off
3170 show auto-load local-gdbinit
3171 Control loading of init file (.gdbinit) from current directory.
3173 set auto-load libthread-db on|off
3174 show auto-load libthread-db
3175 Control auto-loading of inferior specific thread debugging shared library.
3177 set auto-load scripts-directory <dir1>[:<dir2>...]
3178 show auto-load scripts-directory
3179 Set a list of directories from which to load auto-loaded scripts.
3180 Automatically loaded Python scripts and GDB scripts are located in one
3181 of the directories listed by this option.
3182 The delimiter (':' above) may differ according to the host platform.
3184 set auto-load safe-path <dir1>[:<dir2>...]
3185 show auto-load safe-path
3186 Set a list of directories from which it is safe to auto-load files.
3187 The delimiter (':' above) may differ according to the host platform.
3189 set debug auto-load on|off
3190 show debug auto-load
3191 Control display of debugging info for auto-loading the files above.
3193 set dprintf-style gdb|call|agent
3195 Control the way in which a dynamic printf is performed; "gdb"
3196 requests a GDB printf command, while "call" causes dprintf to call a
3197 function in the inferior. "agent" requests that the target agent
3198 (such as GDBserver) do the printing.
3200 set dprintf-function <expr>
3201 show dprintf-function
3202 set dprintf-channel <expr>
3203 show dprintf-channel
3204 Set the function and optional first argument to the call when using
3205 the "call" style of dynamic printf.
3207 set disconnected-dprintf on|off
3208 show disconnected-dprintf
3209 Control whether agent-style dynamic printfs continue to be in effect
3210 after GDB disconnects.
3212 * New configure options
3214 --with-auto-load-dir
3215 Configure default value for the 'set auto-load scripts-directory'
3216 setting above. It defaults to '$debugdir:$datadir/auto-load',
3217 $debugdir representing global debugging info directories (available
3218 via 'show debug-file-directory') and $datadir representing GDB's data
3219 directory (available via 'show data-directory').
3221 --with-auto-load-safe-path
3222 Configure default value for the 'set auto-load safe-path' setting
3223 above. It defaults to the --with-auto-load-dir setting.
3225 --without-auto-load-safe-path
3226 Set 'set auto-load safe-path' to '/', effectively disabling this
3229 * New remote packets
3231 z0/z1 conditional breakpoints extension
3233 The z0/z1 breakpoint insertion packets have been extended to carry
3234 a list of conditional expressions over to the remote stub depending on the
3235 condition evaluation mode. The use of this extension can be controlled
3236 via the "set remote conditional-breakpoints-packet" command.
3240 Specify the signals which the remote stub may pass to the debugged
3241 program without GDB involvement.
3243 * New command line options
3245 --init-command=FILE, -ix Like --command, -x but execute it
3246 before loading inferior.
3247 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3248 execute it before loading inferior.
3250 *** Changes in GDB 7.4
3252 * GDB now handles ambiguous linespecs more consistently; the existing
3253 FILE:LINE support has been expanded to other types of linespecs. A
3254 breakpoint will now be set on all matching locations in all
3255 inferiors, and locations will be added or removed according to
3258 * GDB now allows you to skip uninteresting functions and files when
3259 stepping with the "skip function" and "skip file" commands.
3261 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3262 and "show remote hardware-watchpoint-length-limit". These allows to
3263 set or show the maximum length limit (in bytes) of a remote
3264 target hardware watchpoint.
3266 This allows e.g. to use "unlimited" hardware watchpoints with the
3267 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3268 watchpoints are slower than real hardware watchpoints but are
3269 significantly faster than gdb software watchpoints.
3273 ** The register_pretty_printer function in module gdb.printing now takes
3274 an optional `replace' argument. If True, the new printer replaces any
3277 ** The "maint set python print-stack on|off" command has been
3278 deprecated and will be deleted in GDB 7.5.
3279 A new command: "set python print-stack none|full|message" has
3280 replaced it. Additionally, the default for "print-stack" is
3281 now "message", which just prints the error message without
3284 ** A prompt substitution hook (prompt_hook) is now available to the
3287 ** A new Python module, gdb.prompt has been added to the GDB Python
3288 modules library. This module provides functionality for
3289 escape sequences in prompts (used by set/show
3290 extended-prompt). These escape sequences are replaced by their
3291 corresponding value.
3293 ** Python commands and convenience-functions located in
3294 'data-directory'/python/gdb/command and
3295 'data-directory'/python/gdb/function are now automatically loaded
3298 ** Blocks now provide four new attributes. global_block and
3299 static_block will return the global and static blocks
3300 respectively. is_static and is_global are boolean attributes
3301 that indicate if the block is one of those two types.
3303 ** Symbols now provide the "type" attribute, the type of the symbol.
3305 ** The "gdb.breakpoint" function has been deprecated in favor of
3308 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3309 of a function. This class is based on the "finish" command
3310 available in the CLI.
3312 ** Type objects for struct and union types now allow access to
3313 the fields using standard Python dictionary (mapping) methods.
3314 For example, "some_type['myfield']" now works, as does
3315 "some_type.items()".
3317 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3320 ** A new function, "deep_items" has been added to the gdb.types
3321 module in the GDB Python modules library. This function returns
3322 an iterator over the fields of a struct or union type. Unlike
3323 the standard Python "iteritems" method, it will recursively traverse
3324 any anonymous fields.
3328 ** "*stopped" events can report several new "reason"s, such as
3331 ** Breakpoint changes are now notified using new async records, like
3332 "=breakpoint-modified".
3334 ** New command -ada-task-info.
3336 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3337 $sdir specifies the default system locations of shared libraries.
3338 $pdir specifies the directory where the libpthread used by the application
3341 GDB no longer looks in $sdir and $pdir after it has searched the directories
3342 mentioned in libthread-db-search-path. If you want to search those
3343 directories, they must be specified in libthread-db-search-path.
3344 The default value of libthread-db-search-path on GNU/Linux and Solaris
3345 systems is now "$sdir:$pdir".
3347 $pdir is not supported by gdbserver, it is currently ignored.
3348 $sdir is supported by gdbserver.
3350 * New configure option --with-iconv-bin.
3351 When using the internationalization support like the one in the GNU C
3352 library, GDB will invoke the "iconv" program to get a list of supported
3353 character sets. If this program lives in a non-standard location, one can
3354 use this option to specify where to find it.
3356 * When natively debugging programs on PowerPC BookE processors running
3357 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3358 watchpoints, which specify a mask in addition to an address to watch.
3359 The mask specifies that some bits of an address (the bits which are
3360 reset in the mask) should be ignored when matching the address accessed
3361 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3362 section in the user manual for more details.
3364 * The new option --once causes GDBserver to stop listening for connections once
3365 the first connection is made. The listening port used by GDBserver will
3366 become available after that.
3368 * New commands "info macros" and "alias" have been added.
3370 * New function parameters suffix @entry specifies value of function parameter
3371 at the time the function got called. Entry values are available only since
3377 "!" is now an alias of the "shell" command.
3378 Note that no space is needed between "!" and SHELL COMMAND.
3382 watch EXPRESSION mask MASK_VALUE
3383 The watch command now supports the mask argument which allows creation
3384 of masked watchpoints, if the current architecture supports this feature.
3386 info auto-load-scripts [REGEXP]
3387 This command was formerly named "maintenance print section-scripts".
3388 It is now generally useful and is no longer a maintenance-only command.
3390 info macro [-all] [--] MACRO
3391 The info macro command has new options `-all' and `--'. The first for
3392 printing all definitions of a macro. The second for explicitly specifying
3393 the end of arguments and the beginning of the macro name in case the macro
3394 name starts with a hyphen.
3396 collect[/s] EXPRESSIONS
3397 The tracepoint collect command now takes an optional modifier "/s"
3398 that directs it to dereference pointer-to-character types and
3399 collect the bytes of memory up to a zero byte. The behavior is
3400 similar to what you see when you use the regular print command on a
3401 string. An optional integer following the "/s" sets a bound on the
3402 number of bytes that will be collected.
3405 The trace start command now interprets any supplied arguments as a
3406 note to be recorded with the trace run, with an effect similar to
3407 setting the variable trace-notes.
3410 The trace stop command now interprets any arguments as a note to be
3411 mentioned along with the tstatus report that the trace was stopped
3412 with a command. The effect is similar to setting the variable
3415 * Tracepoints can now be enabled and disabled at any time after a trace
3416 experiment has been started using the standard "enable" and "disable"
3417 commands. It is now possible to start a trace experiment with no enabled
3418 tracepoints; GDB will display a warning, but will allow the experiment to
3419 begin, assuming that tracepoints will be enabled as needed while the trace
3422 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3423 locations with 4-byte instructions, when they were previously
3424 limited to locations with instructions of 5 bytes or longer.
3428 set debug dwarf2-read
3429 show debug dwarf2-read
3430 Turns on or off display of debugging messages related to reading
3431 DWARF debug info. The default is off.
3433 set debug symtab-create
3434 show debug symtab-create
3435 Turns on or off display of debugging messages related to symbol table
3436 creation. The default is off.
3439 show extended-prompt
3440 Set the GDB prompt, and allow escape sequences to be inserted to
3441 display miscellaneous information (see 'help set extended-prompt'
3442 for the list of sequences). This prompt (and any information
3443 accessed through the escape sequences) is updated every time the
3444 prompt is displayed.
3446 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3447 show print entry-values
3448 Set printing of frame argument values at function entry. In some cases
3449 GDB can determine the value of function argument which was passed by the
3450 function caller, even if the value was modified inside the called function.
3452 set debug entry-values
3453 show debug entry-values
3454 Control display of debugging info for determining frame argument values at
3455 function entry and virtual tail call frames.
3457 set basenames-may-differ
3458 show basenames-may-differ
3459 Set whether a source file may have multiple base names.
3460 (A "base name" is the name of a file with the directory part removed.
3461 Example: The base name of "/home/user/hello.c" is "hello.c".)
3462 If set, GDB will canonicalize file names (e.g., expand symlinks)
3463 before comparing them. Canonicalization is an expensive operation,
3464 but it allows the same file be known by more than one base name.
3465 If not set (the default), all source files are assumed to have just
3466 one base name, and gdb will do file name comparisons more efficiently.
3472 Set a user name and notes for the current and any future trace runs.
3473 This is useful for long-running and/or disconnected traces, to
3474 inform others (or yourself) as to who is running the trace, supply
3475 contact information, or otherwise explain what is going on.
3477 set trace-stop-notes
3478 show trace-stop-notes
3479 Set a note attached to the trace run, that is displayed when the
3480 trace has been stopped by a tstop command. This is useful for
3481 instance as an explanation, if you are stopping a trace run that was
3482 started by someone else.
3484 * New remote packets
3488 Dynamically enable a tracepoint in a started trace experiment.
3492 Dynamically disable a tracepoint in a started trace experiment.
3496 Set the user and notes of the trace run.
3500 Query the current status of a tracepoint.
3504 Query the minimum length of instruction at which a fast tracepoint may
3507 * Dcache size (number of lines) and line-size are now runtime-configurable
3508 via "set dcache line" and "set dcache line-size" commands.
3512 Texas Instruments TMS320C6x tic6x-*-*
3516 Renesas RL78 rl78-*-elf
3518 *** Changes in GDB 7.3.1
3520 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3522 *** Changes in GDB 7.3
3524 * GDB has a new command: "thread find [REGEXP]".
3525 It finds the thread id whose name, target id, or thread extra info
3526 matches the given regular expression.
3528 * The "catch syscall" command now works on mips*-linux* targets.
3530 * The -data-disassemble MI command now supports modes 2 and 3 for
3531 dumping the instruction opcodes.
3533 * New command line options
3535 -data-directory DIR Specify DIR as the "data-directory".
3536 This is mostly for testing purposes.
3538 * The "maint set python auto-load on|off" command has been renamed to
3539 "set auto-load-scripts on|off".
3541 * GDB has a new command: "set directories".
3542 It is like the "dir" command except that it replaces the
3543 source path list instead of augmenting it.
3545 * GDB now understands thread names.
3547 On GNU/Linux, "info threads" will display the thread name as set by
3548 prctl or pthread_setname_np.
3550 There is also a new command, "thread name", which can be used to
3551 assign a name internally for GDB to display.
3554 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3555 has been integrated into GDB.
3559 ** The function gdb.Write now accepts an optional keyword 'stream'.
3560 This keyword, when provided, will direct the output to either
3561 stdout, stderr, or GDB's logging output.
3563 ** Parameters can now be be sub-classed in Python, and in particular
3564 you may implement the get_set_doc and get_show_doc functions.
3565 This improves how Parameter set/show documentation is processed
3566 and allows for more dynamic content.
3568 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3569 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3570 have an is_valid method.
3572 ** Breakpoints can now be sub-classed in Python, and in particular
3573 you may implement a 'stop' function that is executed each time
3574 the inferior reaches that breakpoint.
3576 ** New function gdb.lookup_global_symbol looks up a global symbol.
3578 ** GDB values in Python are now callable if the value represents a
3579 function. For example, if 'some_value' represents a function that
3580 takes two integer parameters and returns a value, you can call
3581 that function like so:
3583 result = some_value (10,20)
3585 ** Module gdb.types has been added.
3586 It contains a collection of utilities for working with gdb.Types objects:
3587 get_basic_type, has_field, make_enum_dict.
3589 ** Module gdb.printing has been added.
3590 It contains utilities for writing and registering pretty-printers.
3591 New classes: PrettyPrinter, SubPrettyPrinter,
3592 RegexpCollectionPrettyPrinter.
3593 New function: register_pretty_printer.
3595 ** New commands "info pretty-printers", "enable pretty-printer" and
3596 "disable pretty-printer" have been added.
3598 ** gdb.parameter("directories") is now available.
3600 ** New function gdb.newest_frame returns the newest frame in the
3603 ** The gdb.InferiorThread class has a new "name" attribute. This
3604 holds the thread's name.
3606 ** Python Support for Inferior events.
3607 Python scripts can add observers to be notified of events
3608 occurring in the process being debugged.
3609 The following events are currently supported:
3610 - gdb.events.cont Continue event.
3611 - gdb.events.exited Inferior exited event.
3612 - gdb.events.stop Signal received, and Breakpoint hit events.
3616 ** GDB now puts template parameters in scope when debugging in an
3617 instantiation. For example, if you have:
3619 template<int X> int func (void) { return X; }
3621 then if you step into func<5>, "print X" will show "5". This
3622 feature requires proper debuginfo support from the compiler; it
3623 was added to GCC 4.5.
3625 ** The motion commands "next", "finish", "until", and "advance" now
3626 work better when exceptions are thrown. In particular, GDB will
3627 no longer lose control of the inferior; instead, the GDB will
3628 stop the inferior at the point at which the exception is caught.
3629 This functionality requires a change in the exception handling
3630 code that was introduced in GCC 4.5.
3632 * GDB now follows GCC's rules on accessing volatile objects when
3633 reading or writing target state during expression evaluation.
3634 One notable difference to prior behavior is that "print x = 0"
3635 no longer generates a read of x; the value of the assignment is
3636 now always taken directly from the value being assigned.
3638 * GDB now has some support for using labels in the program's source in
3639 linespecs. For instance, you can use "advance label" to continue
3640 execution to a label.
3642 * GDB now has support for reading and writing a new .gdb_index
3643 section. This section holds a fast index of DWARF debugging
3644 information and can be used to greatly speed up GDB startup and
3645 operation. See the documentation for `save gdb-index' for details.
3647 * The "watch" command now accepts an optional "-location" argument.
3648 When used, this causes GDB to watch the memory referred to by the
3649 expression. Such a watchpoint is never deleted due to it going out
3652 * GDB now supports thread debugging of core dumps on GNU/Linux.
3654 GDB now activates thread debugging using the libthread_db library
3655 when debugging GNU/Linux core dumps, similarly to when debugging
3656 live processes. As a result, when debugging a core dump file, GDB
3657 is now able to display pthread_t ids of threads. For example, "info
3658 threads" shows the same output as when debugging the process when it
3659 was live. In earlier releases, you'd see something like this:
3662 * 1 LWP 6780 main () at main.c:10
3664 While now you see this:
3667 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3669 It is also now possible to inspect TLS variables when debugging core
3672 When debugging a core dump generated on a machine other than the one
3673 used to run GDB, you may need to point GDB at the correct
3674 libthread_db library with the "set libthread-db-search-path"
3675 command. See the user manual for more details on this command.
3677 * When natively debugging programs on PowerPC BookE processors running
3678 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3679 which stop execution of the inferior whenever it executes an instruction
3680 at any address within the specified range. See the "PowerPC Embedded"
3681 section in the user manual for more details.
3683 * New features in the GDB remote stub, GDBserver
3685 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3686 and i686 LynxOS (version 5.x).
3688 ** GDBserver is now supported on Blackfin Linux.
3690 * New native configurations
3692 ia64 HP-UX ia64-*-hpux*
3696 Analog Devices, Inc. Blackfin Processor bfin-*
3698 * Ada task switching is now supported on sparc-elf targets when
3699 debugging a program using the Ravenscar Profile. For more information,
3700 see the "Tasking Support when using the Ravenscar Profile" section
3701 in the GDB user manual.
3703 * Guile support was removed.
3705 * New features in the GNU simulator
3707 ** The --map-info flag lists all known core mappings.
3709 ** CFI flashes may be simulated via the "cfi" device.
3711 *** Changes in GDB 7.2
3713 * Shared library support for remote targets by default
3715 When GDB is configured for a generic, non-OS specific target, like
3716 for example, --target=arm-eabi or one of the many *-*-elf targets,
3717 GDB now queries remote stubs for loaded shared libraries using the
3718 `qXfer:libraries:read' packet. Previously, shared library support
3719 was always disabled for such configurations.
3723 ** Argument Dependent Lookup (ADL)
3725 In C++ ADL lookup directs function search to the namespaces of its
3726 arguments even if the namespace has not been imported.
3736 Here the compiler will search for `foo' in the namespace of 'b'
3737 and find A::foo. GDB now supports this. This construct is commonly
3738 used in the Standard Template Library for operators.
3740 ** Improved User Defined Operator Support
3742 In addition to member operators, GDB now supports lookup of operators
3743 defined in a namespace and imported with a `using' directive, operators
3744 defined in the global scope, operators imported implicitly from an
3745 anonymous namespace, and the ADL operators mentioned in the previous
3747 GDB now also supports proper overload resolution for all the previously
3748 mentioned flavors of operators.
3750 ** static const class members
3752 Printing of static const class members that are initialized in the
3753 class definition has been fixed.
3755 * Windows Thread Information Block access.
3757 On Windows targets, GDB now supports displaying the Windows Thread
3758 Information Block (TIB) structure. This structure is visible either
3759 by using the new command `info w32 thread-information-block' or, by
3760 dereferencing the new convenience variable named `$_tlb', a
3761 thread-specific pointer to the TIB. This feature is also supported
3762 when remote debugging using GDBserver.
3764 * Static tracepoints
3766 Static tracepoints are calls in the user program into a tracing
3767 library. One such library is a port of the LTTng kernel tracer to
3768 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3769 When debugging with GDBserver, GDB now supports combining the GDB
3770 tracepoint machinery with such libraries. For example: the user can
3771 use GDB to probe a static tracepoint marker (a call from the user
3772 program into the tracing library) with the new "strace" command (see
3773 "New commands" below). This creates a "static tracepoint" in the
3774 breakpoint list, that can be manipulated with the same feature set
3775 as fast and regular tracepoints. E.g., collect registers, local and
3776 global variables, collect trace state variables, and define
3777 tracepoint conditions. In addition, the user can collect extra
3778 static tracepoint marker specific data, by collecting the new
3779 $_sdata internal variable. When analyzing the trace buffer, you can
3780 inspect $_sdata like any other variable available to GDB. For more
3781 information, see the "Tracepoints" chapter in GDB user manual. New
3782 remote packets have been defined to support static tracepoints, see
3783 the "New remote packets" section below.
3785 * Better reconstruction of tracepoints after disconnected tracing
3787 GDB will attempt to download the original source form of tracepoint
3788 definitions when starting a trace run, and then will upload these
3789 upon reconnection to the target, resulting in a more accurate
3790 reconstruction of the tracepoints that are in use on the target.
3794 You can now exercise direct control over the ways that GDB can
3795 affect your program. For instance, you can disallow the setting of
3796 breakpoints, so that the program can run continuously (assuming
3797 non-stop mode). In addition, the "observer" variable is available
3798 to switch all of the different controls; in observer mode, GDB
3799 cannot affect the target's behavior at all, which is useful for
3800 tasks like diagnosing live systems in the field.
3802 * The new convenience variable $_thread holds the number of the
3805 * New remote packets
3809 Return the address of the Windows Thread Information Block of a given thread.
3813 In response to several of the tracepoint packets, the target may now
3814 also respond with a number of intermediate `qRelocInsn' request
3815 packets before the final result packet, to have GDB handle
3816 relocating an instruction to execute at a different address. This
3817 is particularly useful for stubs that support fast tracepoints. GDB
3818 reports support for this feature in the qSupported packet.
3822 List static tracepoint markers in the target program.
3826 List static tracepoint markers at a given address in the target
3829 qXfer:statictrace:read
3831 Read the static trace data collected (by a `collect $_sdata'
3832 tracepoint action). The remote stub reports support for this packet
3833 to gdb's qSupported query.
3837 Send the current settings of GDB's permission flags.
3841 Send part of the source (textual) form of a tracepoint definition,
3842 which includes location, conditional, and action list.
3844 * The source command now accepts a -s option to force searching for the
3845 script in the source search path even if the script name specifies
3848 * New features in the GDB remote stub, GDBserver
3850 - GDBserver now support tracepoints (including fast tracepoints, and
3851 static tracepoints). The feature is currently supported by the
3852 i386-linux and amd64-linux builds. See the "Tracepoints support
3853 in gdbserver" section in the manual for more information.
3855 GDBserver JIT compiles the tracepoint's conditional agent
3856 expression bytecode into native code whenever possible for low
3857 overhead dynamic tracepoints conditionals. For such tracepoints,
3858 an expression that examines program state is evaluated when the
3859 tracepoint is reached, in order to determine whether to capture
3860 trace data. If the condition is simple and false, processing the
3861 tracepoint finishes very quickly and no data is gathered.
3863 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3864 for static tracepoints support.
3866 - GDBserver now supports x86_64 Windows 64-bit debugging.
3868 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3869 it understands register description.
3871 * The --batch flag now disables pagination and queries.
3873 * X86 general purpose registers
3875 GDB now supports reading/writing byte, word and double-word x86
3876 general purpose registers directly. This means you can use, say,
3877 $ah or $ax to refer, respectively, to the byte register AH and
3878 16-bit word register AX that are actually portions of the 32-bit
3879 register EAX or 64-bit register RAX.
3881 * The `commands' command now accepts a range of breakpoints to modify.
3882 A plain `commands' following a command that creates multiple
3883 breakpoints affects all the breakpoints set by that command. This
3884 applies to breakpoints set by `rbreak', and also applies when a
3885 single `break' command creates multiple breakpoints (e.g.,
3886 breakpoints on overloaded c++ functions).
3888 * The `rbreak' command now accepts a filename specification as part of
3889 its argument, limiting the functions selected by the regex to those
3890 in the specified file.
3892 * Support for remote debugging Windows and SymbianOS shared libraries
3893 from Unix hosts has been improved. Non Windows GDB builds now can
3894 understand target reported file names that follow MS-DOS based file
3895 system semantics, such as file names that include drive letters and
3896 use the backslash character as directory separator. This makes it
3897 possible to transparently use the "set sysroot" and "set
3898 solib-search-path" on Unix hosts to point as host copies of the
3899 target's shared libraries. See the new command "set
3900 target-file-system-kind" described below, and the "Commands to
3901 specify files" section in the user manual for more information.
3905 eval template, expressions...
3906 Convert the values of one or more expressions under the control
3907 of the string template to a command line, and call it.
3909 set target-file-system-kind unix|dos-based|auto
3910 show target-file-system-kind
3911 Set or show the assumed file system kind for target reported file
3914 save breakpoints <filename>
3915 Save all current breakpoint definitions to a file suitable for use
3916 in a later debugging session. To read the saved breakpoint
3917 definitions, use the `source' command.
3919 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3922 info static-tracepoint-markers
3923 Display information about static tracepoint markers in the target.
3925 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3926 Define a static tracepoint by probing a marker at the given
3927 function, line, address, or marker ID.
3931 Enable and disable observer mode.
3933 set may-write-registers on|off
3934 set may-write-memory on|off
3935 set may-insert-breakpoints on|off
3936 set may-insert-tracepoints on|off
3937 set may-insert-fast-tracepoints on|off
3938 set may-interrupt on|off
3939 Set individual permissions for GDB effects on the target. Note that
3940 some of these settings can have undesirable or surprising
3941 consequences, particularly when changed in the middle of a session.
3942 For instance, disabling the writing of memory can prevent
3943 breakpoints from being inserted, cause single-stepping to fail, or
3944 even crash your program, if you disable after breakpoints have been
3945 inserted. However, GDB should not crash.
3947 set record memory-query on|off
3948 show record memory-query
3949 Control whether to stop the inferior if memory changes caused
3950 by an instruction cannot be recorded.
3955 The disassemble command now supports "start,+length" form of two arguments.
3959 ** GDB now provides a new directory location, called the python directory,
3960 where Python scripts written for GDB can be installed. The location
3961 of that directory is <data-directory>/python, where <data-directory>
3962 is the GDB data directory. For more details, see section `Scripting
3963 GDB using Python' in the manual.
3965 ** The GDB Python API now has access to breakpoints, symbols, symbol
3966 tables, program spaces, inferiors, threads and frame's code blocks.
3967 Additionally, GDB Parameters can now be created from the API, and
3968 manipulated via set/show in the CLI.
3970 ** New functions gdb.target_charset, gdb.target_wide_charset,
3971 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3973 ** New exception gdb.GdbError.
3975 ** Pretty-printers are now also looked up in the current program space.
3977 ** Pretty-printers can now be individually enabled and disabled.
3979 ** GDB now looks for names of Python scripts to auto-load in a
3980 special section named `.debug_gdb_scripts', in addition to looking
3981 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3983 * Tracepoint actions were unified with breakpoint commands. In particular,
3984 there are no longer differences in "info break" output for breakpoints and
3985 tracepoints and the "commands" command can be used for both tracepoints and
3986 regular breakpoints.
3990 ARM Symbian arm*-*-symbianelf*
3992 * D language support.
3993 GDB now supports debugging programs written in the D programming
3996 * GDB now supports the extended ptrace interface for PowerPC which is
3997 available since Linux kernel version 2.6.34. This automatically enables
3998 any hardware breakpoints and additional hardware watchpoints available in
3999 the processor. The old ptrace interface exposes just one hardware
4000 watchpoint and no hardware breakpoints.
4002 * GDB is now able to use the Data Value Compare (DVC) register available on
4003 embedded PowerPC processors to implement in hardware simple watchpoint
4004 conditions of the form:
4006 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4008 This works in native GDB running on Linux kernels with the extended ptrace
4009 interface mentioned above.
4011 *** Changes in GDB 7.1
4015 ** Namespace Support
4017 GDB now supports importing of namespaces in C++. This enables the
4018 user to inspect variables from imported namespaces. Support for
4019 namepace aliasing has also been added. So, if a namespace is
4020 aliased in the current scope (e.g. namepace C=A; ) the user can
4021 print variables using the alias (e.g. (gdb) print C::x).
4025 All known bugs relating to the printing of virtual base class were
4026 fixed. It is now possible to call overloaded static methods using a
4031 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4032 and reinterpret_cast<> are now handled by the C++ expression parser.
4036 Xilinx MicroBlaze microblaze-*-*
4041 Xilinx MicroBlaze microblaze
4044 * Multi-program debugging.
4046 GDB now has support for multi-program (a.k.a. multi-executable or
4047 multi-exec) debugging. This allows for debugging multiple inferiors
4048 simultaneously each running a different program under the same GDB
4049 session. See "Debugging Multiple Inferiors and Programs" in the
4050 manual for more information. This implied some user visible changes
4051 in the multi-inferior support. For example, "info inferiors" now
4052 lists inferiors that are not running yet or that have exited
4053 already. See also "New commands" and "New options" below.
4055 * New tracing features
4057 GDB's tracepoint facility now includes several new features:
4059 ** Trace state variables
4061 GDB tracepoints now include support for trace state variables, which
4062 are variables managed by the target agent during a tracing
4063 experiment. They are useful for tracepoints that trigger each
4064 other, so for instance one tracepoint can count hits in a variable,
4065 and then a second tracepoint has a condition that is true when the
4066 count reaches a particular value. Trace state variables share the
4067 $-syntax of GDB convenience variables, and can appear in both
4068 tracepoint actions and condition expressions. Use the "tvariable"
4069 command to create, and "info tvariables" to view; see "Trace State
4070 Variables" in the manual for more detail.
4074 GDB now includes an option for defining fast tracepoints, which
4075 targets may implement more efficiently, such as by installing a jump
4076 into the target agent rather than a trap instruction. The resulting
4077 speedup can be by two orders of magnitude or more, although the
4078 tradeoff is that some program locations on some target architectures
4079 might not allow fast tracepoint installation, for instance if the
4080 instruction to be replaced is shorter than the jump. To request a
4081 fast tracepoint, use the "ftrace" command, with syntax identical to
4082 the regular trace command.
4084 ** Disconnected tracing
4086 It is now possible to detach GDB from the target while it is running
4087 a trace experiment, then reconnect later to see how the experiment
4088 is going. In addition, a new variable disconnected-tracing lets you
4089 tell the target agent whether to continue running a trace if the
4090 connection is lost unexpectedly.
4094 GDB now has the ability to save the trace buffer into a file, and
4095 then use that file as a target, similarly to you can do with
4096 corefiles. You can select trace frames, print data that was
4097 collected in them, and use tstatus to display the state of the
4098 tracing run at the moment that it was saved. To create a trace
4099 file, use "tsave <filename>", and to use it, do "target tfile
4102 ** Circular trace buffer
4104 You can ask the target agent to handle the trace buffer as a
4105 circular buffer, discarding the oldest trace frames to make room for
4106 newer ones, by setting circular-trace-buffer to on. This feature may
4107 not be available for all target agents.
4112 The disassemble command, when invoked with two arguments, now requires
4113 the arguments to be comma-separated.
4116 The info variables command now displays variable definitions. Files
4117 which only declare a variable are not shown.
4120 The source command is now capable of sourcing Python scripts.
4121 This feature is dependent on the debugger being build with Python
4124 Related to this enhancement is also the introduction of a new command
4125 "set script-extension" (see below).
4127 * New commands (for set/show, see "New options" below)
4129 record save [<FILENAME>]
4130 Save a file (in core file format) containing the process record
4131 execution log for replay debugging at a later time.
4133 record restore <FILENAME>
4134 Restore the process record execution log that was saved at an
4135 earlier time, for replay debugging.
4137 add-inferior [-copies <N>] [-exec <FILENAME>]
4140 clone-inferior [-copies <N>] [ID]
4141 Make a new inferior ready to execute the same program another
4142 inferior has loaded.
4147 maint info program-spaces
4148 List the program spaces loaded into GDB.
4150 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4151 show remote interrupt-sequence
4152 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4153 as the sequence to the remote target in order to interrupt the execution.
4154 Ctrl-C is a default. Some system prefers BREAK which is high level of
4155 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4156 Magic SysRq g. It is BREAK signal and character 'g'.
4158 set remote interrupt-on-connect [on | off]
4159 show remote interrupt-on-connect
4160 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4161 remote target when gdb connects to it. This is needed when you debug
4164 set remotebreak [on | off]
4166 Deprecated. Use "set/show remote interrupt-sequence" instead.
4168 tvariable $NAME [ = EXP ]
4169 Create or modify a trace state variable.
4172 List trace state variables and their values.
4174 delete tvariable $NAME ...
4175 Delete one or more trace state variables.
4178 Evaluate the given expressions without collecting anything into the
4179 trace buffer. (Valid in tracepoint actions only.)
4181 ftrace FN / FILE:LINE / *ADDR
4182 Define a fast tracepoint at the given function, line, or address.
4184 * New expression syntax
4186 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4187 GDB now parses 0b101010 identically with 42.
4191 set follow-exec-mode new|same
4192 show follow-exec-mode
4193 Control whether GDB reuses the same inferior across an exec call or
4194 creates a new one. This is useful to be able to restart the old
4195 executable after the inferior having done an exec call.
4197 set default-collect EXPR, ...
4198 show default-collect
4199 Define a list of expressions to be collected at each tracepoint.
4200 This is a useful way to ensure essential items are not overlooked,
4201 such as registers or a critical global variable.
4203 set disconnected-tracing
4204 show disconnected-tracing
4205 If set to 1, the target is instructed to continue tracing if it
4206 loses its connection to GDB. If 0, the target is to stop tracing
4209 set circular-trace-buffer
4210 show circular-trace-buffer
4211 If set to on, the target is instructed to use a circular trace buffer
4212 and discard the oldest trace frames instead of stopping the trace due
4213 to a full trace buffer. If set to off, the trace stops when the buffer
4214 fills up. Some targets may not support this.
4216 set script-extension off|soft|strict
4217 show script-extension
4218 If set to "off", the debugger does not perform any script language
4219 recognition, and all sourced files are assumed to be GDB scripts.
4220 If set to "soft" (the default), files are sourced according to
4221 filename extension, falling back to GDB scripts if the first
4223 If set to "strict", files are sourced according to filename extension.
4225 set ada trust-PAD-over-XVS on|off
4226 show ada trust-PAD-over-XVS
4227 If off, activate a workaround against a bug in the debugging information
4228 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4229 the GCC sources for more information about the GNAT encoding and
4230 PAD types in particular). It is always safe to set this option to
4231 off, but this introduces a slight performance penalty. The default
4234 * Python API Improvements
4236 ** GDB provides the new class gdb.LazyString. This is useful in
4237 some pretty-printing cases. The new method gdb.Value.lazy_string
4238 provides a simple way to create objects of this type.
4240 ** The fields returned by gdb.Type.fields now have an
4241 `is_base_class' attribute.
4243 ** The new method gdb.Type.range returns the range of an array type.
4245 ** The new method gdb.parse_and_eval can be used to parse and
4246 evaluate an expression.
4248 * New remote packets
4251 Define a trace state variable.
4254 Get the current value of a trace state variable.
4257 Set desired tracing behavior upon disconnection.
4260 Set the trace buffer to be linear or circular.
4263 Get data about the tracepoints currently in use.
4267 Process record now works correctly with hardware watchpoints.
4269 Multiple bug fixes have been made to the mips-irix port, making it
4270 much more reliable. In particular:
4271 - Debugging threaded applications is now possible again. Previously,
4272 GDB would hang while starting the program, or while waiting for
4273 the program to stop at a breakpoint.
4274 - Attaching to a running process no longer hangs.
4275 - An error occurring while loading a core file has been fixed.
4276 - Changing the value of the PC register now works again. This fixes
4277 problems observed when using the "jump" command, or when calling
4278 a function from GDB, or even when assigning a new value to $pc.
4279 - With the "finish" and "return" commands, the return value for functions
4280 returning a small array is now correctly printed.
4281 - It is now possible to break on shared library code which gets executed
4282 during a shared library init phase (code executed while executing
4283 their .init section). Previously, the breakpoint would have no effect.
4284 - GDB is now able to backtrace through the signal handler for
4285 non-threaded programs.
4287 PIE (Position Independent Executable) programs debugging is now supported.
4288 This includes debugging execution of PIC (Position Independent Code) shared
4289 libraries although for that, it should be possible to run such libraries as an
4292 *** Changes in GDB 7.0
4294 * GDB now has an interface for JIT compilation. Applications that
4295 dynamically generate code can create symbol files in memory and register
4296 them with GDB. For users, the feature should work transparently, and
4297 for JIT developers, the interface is documented in the GDB manual in the
4298 "JIT Compilation Interface" chapter.
4300 * Tracepoints may now be conditional. The syntax is as for
4301 breakpoints; either an "if" clause appended to the "trace" command,
4302 or the "condition" command is available. GDB sends the condition to
4303 the target for evaluation using the same bytecode format as is used
4304 for tracepoint actions.
4306 * The disassemble command now supports: an optional /r modifier, print the
4307 raw instructions in hex as well as in symbolic form, and an optional /m
4308 modifier to print mixed source+assembly.
4310 * Process record and replay
4312 In a architecture environment that supports ``process record and
4313 replay'', ``process record and replay'' target can record a log of
4314 the process execution, and replay it with both forward and reverse
4317 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4318 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4319 set execution-direction {forward|reverse}, for targets that support
4322 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4323 feature is available with a native GDB running on kernel version
4326 * GDB now has support for multi-byte and wide character sets on the
4327 target. Strings whose character type is wchar_t, char16_t, or
4328 char32_t are now correctly printed. GDB supports wide- and unicode-
4329 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4330 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4331 `printf'. This feature requires iconv to work properly; if your
4332 system does not have a working iconv, GDB can use GNU libiconv. See
4333 the installation instructions for more information.
4335 * GDB now supports automatic retrieval of shared library files from
4336 remote targets. To use this feature, specify a system root that begins
4337 with the `remote:' prefix, either via the `set sysroot' command or via
4338 the `--with-sysroot' configure-time option.
4340 * "info sharedlibrary" now takes an optional regex of libraries to show,
4341 and it now reports if a shared library has no debugging information.
4343 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4344 now complete on file names.
4346 * When completing in expressions, gdb will attempt to limit
4347 completions to allowable structure or union fields, where appropriate.
4348 For instance, consider:
4350 # struct example { int f1; double f2; };
4351 # struct example variable;
4354 If the user types TAB at the end of this command line, the available
4355 completions will be "f1" and "f2".
4357 * Inlined functions are now supported. They show up in backtraces, and
4358 the "step", "next", and "finish" commands handle them automatically.
4360 * GDB now supports the token-splicing (##) and stringification (#)
4361 operators when expanding macros. It also supports variable-arity
4364 * GDB now supports inspecting extra signal information, exported by
4365 the new $_siginfo convenience variable. The feature is currently
4366 implemented on linux ARM, i386 and amd64.
4368 * GDB can now display the VFP floating point registers and NEON vector
4369 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4370 can provide these registers (requires Linux 2.6.30 or later). Remote
4371 and simulator targets may also provide them.
4373 * New remote packets
4376 Search memory for a sequence of bytes.
4379 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4380 operation over reliable transport links. Use of this packet is
4381 controlled by the `set remote noack-packet' command.
4384 Kill the process with the specified process ID. Use this in preference
4385 to `k' when multiprocess protocol extensions are supported.
4388 Obtains additional operating system information
4392 Read or write additional signal information.
4394 * Removed remote protocol undocumented extension
4396 An undocumented extension to the remote protocol's `S' stop reply
4397 packet that permitted the stub to pass a process id was removed.
4398 Remote servers should use the `T' stop reply packet instead.
4400 * GDB now supports multiple function calling conventions according to the
4401 DWARF-2 DW_AT_calling_convention function attribute.
4403 * The SH target utilizes the aforementioned change to distinguish between gcc
4404 and Renesas calling convention. It also adds the new CLI commands
4405 `set/show sh calling-convention'.
4407 * GDB can now read compressed debug sections, as produced by GNU gold
4408 with the --compress-debug-sections=zlib flag.
4410 * 64-bit core files are now supported on AIX.
4412 * Thread switching is now supported on Tru64.
4414 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4415 which will be allocated using malloc later in program execution.
4417 * The qXfer:libraries:read remote protocol packet now allows passing a
4418 list of section offsets.
4420 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4421 conditions handling signals delivered during attach or thread creation
4422 have also been fixed.
4424 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4425 From the user's standpoint, all unqualified instances of True and False
4426 are treated as the standard definitions, regardless of context.
4428 * GDB now parses C++ symbol and type names more flexibly. For
4431 template<typename T> class C { };
4434 GDB will now correctly handle all of:
4436 ptype C<char const *>
4437 ptype C<char const*>
4438 ptype C<const char *>
4439 ptype C<const char*>
4441 * New features in the GDB remote stub, gdbserver
4443 - The "--wrapper" command-line argument tells gdbserver to use a
4444 wrapper program to launch programs for debugging.
4446 - On PowerPC and S/390 targets, it is now possible to use a single
4447 gdbserver executable to debug both 32-bit and 64-bit programs.
4448 (This requires gdbserver itself to be built as a 64-bit executable.)
4450 - gdbserver uses the new noack protocol mode for TCP connections to
4451 reduce communications latency, if also supported and enabled in GDB.
4453 - Support for the sparc64-linux-gnu target is now included in
4456 - The amd64-linux build of gdbserver now supports debugging both
4457 32-bit and 64-bit programs.
4459 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4460 now support hardware watchpoints, and will use them automatically
4465 GDB now has support for scripting using Python. Whether this is
4466 available is determined at configure time.
4468 New GDB commands can now be written in Python.
4470 * Ada tasking support
4472 Ada tasks can now be inspected in GDB. The following commands have
4476 Print the list of Ada tasks.
4478 Print detailed information about task number N.
4480 Print the task number of the current task.
4482 Switch the context of debugging to task number N.
4484 * Support for user-defined prefixed commands. The "define" command can
4485 add new commands to existing prefixes, e.g. "target".
4487 * Multi-inferior, multi-process debugging.
4489 GDB now has generalized support for multi-inferior debugging. See
4490 "Debugging Multiple Inferiors" in the manual for more information.
4491 Although availability still depends on target support, the command
4492 set is more uniform now. The GNU/Linux specific multi-forks support
4493 has been migrated to this new framework. This implied some user
4494 visible changes; see "New commands" and also "Removed commands"
4497 * Target descriptions can now describe the target OS ABI. See the
4498 "Target Description Format" section in the user manual for more
4501 * Target descriptions can now describe "compatible" architectures
4502 to indicate that the target can execute applications for a different
4503 architecture in addition to those for the main target architecture.
4504 See the "Target Description Format" section in the user manual for
4507 * Multi-architecture debugging.
4509 GDB now includes general supports for debugging applications on
4510 hybrid systems that use more than one single processor architecture
4511 at the same time. Each such hybrid architecture still requires
4512 specific support to be added. The only hybrid architecture supported
4513 in this version of GDB is the Cell Broadband Engine.
4515 * GDB now supports integrated debugging of Cell/B.E. applications that
4516 use both the PPU and SPU architectures. To enable support for hybrid
4517 Cell/B.E. debugging, you need to configure GDB to support both the
4518 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4519 --enable-targets configure option.
4521 * Non-stop mode debugging.
4523 For some targets, GDB now supports an optional mode of operation in
4524 which you can examine stopped threads while other threads continue
4525 to execute freely. This is referred to as non-stop mode, with the
4526 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4527 section in the user manual for more information.
4529 To be able to support remote non-stop debugging, a remote stub needs
4530 to implement the non-stop mode remote protocol extensions, as
4531 described in the "Remote Non-Stop" section of the user manual. The
4532 GDB remote stub, gdbserver, has been adjusted to support these
4533 extensions on linux targets.
4535 * New commands (for set/show, see "New options" below)
4537 catch syscall [NAME(S) | NUMBER(S)]
4538 Catch system calls. Arguments, which should be names of system
4539 calls or their numbers, mean catch only those syscalls. Without
4540 arguments, every syscall will be caught. When the inferior issues
4541 any of the specified syscalls, GDB will stop and announce the system
4542 call, both when it is called and when its call returns. This
4543 feature is currently available with a native GDB running on the
4544 Linux Kernel, under the following architectures: x86, x86_64,
4545 PowerPC and PowerPC64.
4547 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4549 Search memory for a sequence of bytes.
4551 maint set python print-stack
4552 maint show python print-stack
4553 Show a stack trace when an error is encountered in a Python script.
4556 Invoke CODE by passing it to the Python interpreter.
4561 These allow macros to be defined, undefined, and listed
4565 Show operating system information about processes.
4568 List the inferiors currently under GDB's control.
4571 Switch focus to inferior number NUM.
4574 Detach from inferior number NUM.
4577 Kill inferior number NUM.
4581 set spu stop-on-load
4582 show spu stop-on-load
4583 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4585 set spu auto-flush-cache
4586 show spu auto-flush-cache
4587 Control whether to automatically flush the software-managed cache
4588 during Cell/B.E. debugging.
4590 set sh calling-convention
4591 show sh calling-convention
4592 Control the calling convention used when calling SH target functions.
4595 show debug timestamp
4596 Control display of timestamps with GDB debugging output.
4598 set disassemble-next-line
4599 show disassemble-next-line
4600 Control display of disassembled source lines or instructions when
4603 set remote noack-packet
4604 show remote noack-packet
4605 Set/show the use of remote protocol QStartNoAckMode packet. See above
4606 under "New remote packets."
4608 set remote query-attached-packet
4609 show remote query-attached-packet
4610 Control use of remote protocol `qAttached' (query-attached) packet.
4612 set remote read-siginfo-object
4613 show remote read-siginfo-object
4614 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4617 set remote write-siginfo-object
4618 show remote write-siginfo-object
4619 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4622 set remote reverse-continue
4623 show remote reverse-continue
4624 Control use of remote protocol 'bc' (reverse-continue) packet.
4626 set remote reverse-step
4627 show remote reverse-step
4628 Control use of remote protocol 'bs' (reverse-step) packet.
4630 set displaced-stepping
4631 show displaced-stepping
4632 Control displaced stepping mode. Displaced stepping is a way to
4633 single-step over breakpoints without removing them from the debuggee.
4634 Also known as "out-of-line single-stepping".
4637 show debug displaced
4638 Control display of debugging info for displaced stepping.
4640 maint set internal-error
4641 maint show internal-error
4642 Control what GDB does when an internal error is detected.
4644 maint set internal-warning
4645 maint show internal-warning
4646 Control what GDB does when an internal warning is detected.
4651 Use a wrapper program to launch programs for debugging.
4653 set multiple-symbols (all|ask|cancel)
4654 show multiple-symbols
4655 The value of this variable can be changed to adjust the debugger behavior
4656 when an expression or a breakpoint location contains an ambiguous symbol
4657 name (an overloaded function name, for instance).
4659 set breakpoint always-inserted
4660 show breakpoint always-inserted
4661 Keep breakpoints always inserted in the target, as opposed to inserting
4662 them when resuming the target, and removing them when the target stops.
4663 This option can improve debugger performance on slow remote targets.
4665 set arm fallback-mode (arm|thumb|auto)
4666 show arm fallback-mode
4667 set arm force-mode (arm|thumb|auto)
4669 These commands control how ARM GDB determines whether instructions
4670 are ARM or Thumb. The default for both settings is auto, which uses
4671 the current CPSR value for instructions without symbols; previous
4672 versions of GDB behaved as if "set arm fallback-mode arm".
4674 set disable-randomization
4675 show disable-randomization
4676 Standalone programs run with the virtual address space randomization enabled
4677 by default on some platforms. This option keeps the addresses stable across
4678 multiple debugging sessions.
4682 Control whether other threads are stopped or not when some thread hits
4687 Requests that asynchronous execution is enabled in the target, if available.
4688 In this case, it's possible to resume target in the background, and interact
4689 with GDB while the target is running. "show target-async" displays the
4690 current state of asynchronous execution of the target.
4692 set target-wide-charset
4693 show target-wide-charset
4694 The target-wide-charset is the name of the character set that GDB
4695 uses when printing characters whose type is wchar_t.
4697 set tcp auto-retry (on|off)
4699 set tcp connect-timeout
4700 show tcp connect-timeout
4701 These commands allow GDB to retry failed TCP connections to a remote stub
4702 with a specified timeout period; this is useful if the stub is launched
4703 in parallel with GDB but may not be ready to accept connections immediately.
4705 set libthread-db-search-path
4706 show libthread-db-search-path
4707 Control list of directories which GDB will search for appropriate
4710 set schedule-multiple (on|off)
4711 show schedule-multiple
4712 Allow GDB to resume all threads of all processes or only threads of
4713 the current process.
4717 Use more aggressive caching for accesses to the stack. This improves
4718 performance of remote debugging (particularly backtraces) without
4719 affecting correctness.
4721 set interactive-mode (on|off|auto)
4722 show interactive-mode
4723 Control whether GDB runs in interactive mode (on) or not (off).
4724 When in interactive mode, GDB waits for the user to answer all
4725 queries. Otherwise, GDB does not wait and assumes the default
4726 answer. When set to auto (the default), GDB determines which
4727 mode to use based on the stdin settings.
4732 For program forks, this is replaced by the new more generic `info
4733 inferiors' command. To list checkpoints, you can still use the
4734 `info checkpoints' command, which was an alias for the `info forks'
4738 Replaced by the new `inferior' command. To switch between
4739 checkpoints, you can still use the `restart' command, which was an
4740 alias for the `fork' command.
4743 This is removed, since some targets don't have a notion of
4744 processes. To switch between processes, you can still use the
4745 `inferior' command using GDB's own inferior number.
4748 For program forks, this is replaced by the new more generic `kill
4749 inferior' command. To delete a checkpoint, you can still use the
4750 `delete checkpoint' command, which was an alias for the `delete
4754 For program forks, this is replaced by the new more generic `detach
4755 inferior' command. To detach a checkpoint, you can still use the
4756 `detach checkpoint' command, which was an alias for the `detach
4759 * New native configurations
4761 x86/x86_64 Darwin i[34567]86-*-darwin*
4763 x86_64 MinGW x86_64-*-mingw*
4767 Lattice Mico32 lm32-*
4768 x86 DICOS i[34567]86-*-dicos*
4769 x86_64 DICOS x86_64-*-dicos*
4772 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4773 (mingw32ce) debugging.
4779 These commands were actually not implemented on any target.
4781 *** Changes in GDB 6.8
4783 * New native configurations
4785 NetBSD/hppa hppa*-*netbsd*
4786 Xtensa GNU/Linux xtensa*-*-linux*
4790 NetBSD/hppa hppa*-*-netbsd*
4791 Xtensa GNU/Linux xtensa*-*-linux*
4793 * Change in command line behavior -- corefiles vs. process ids.
4795 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4796 attaching to process NUMBER fails, GDB no longer attempts to open a
4797 core file named NUMBER. Attaching to a program using the -c option
4798 is no longer supported. Instead, use the '-p' or '--pid' options.
4800 * GDB can now be built as a native debugger for debugging Windows x86
4801 (mingw32) Portable Executable (PE) programs.
4803 * Pending breakpoints no longer change their number when their address
4806 * GDB now supports breakpoints with multiple locations,
4807 including breakpoints on C++ constructors, inside C++ templates,
4808 and in inlined functions.
4810 * GDB's ability to debug optimized code has been improved. GDB more
4811 accurately identifies function bodies and lexical blocks that occupy
4812 more than one contiguous range of addresses.
4814 * Target descriptions can now describe registers for PowerPC.
4816 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4817 registers on PowerPC targets.
4819 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4820 targets even when the libthread_db library is not available.
4822 * The GDB remote stub, gdbserver, now supports the new file transfer
4823 commands (remote put, remote get, and remote delete).
4825 * The GDB remote stub, gdbserver, now supports run and attach in
4826 extended-remote mode.
4828 * hppa*64*-*-hpux11* target broken
4829 The debugger is unable to start a program and fails with the following
4830 error: "Error trying to get information about dynamic linker".
4831 The gdb-6.7 release is also affected.
4833 * GDB now supports the --enable-targets= configure option to allow
4834 building a single GDB executable that supports multiple remote
4835 target architectures.
4837 * GDB now supports debugging C and C++ programs which use the
4838 Decimal Floating Point extension. In addition, the PowerPC target
4839 now has a set of pseudo-registers to inspect decimal float values
4840 stored in two consecutive float registers.
4842 * The -break-insert MI command can optionally create pending
4845 * Improved support for debugging Ada
4846 Many improvements to the Ada language support have been made. These
4848 - Better support for Ada2005 interface types
4849 - Improved handling of arrays and slices in general
4850 - Better support for Taft-amendment types
4851 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4853 - Improved command completion in Ada
4856 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4861 set print frame-arguments (all|scalars|none)
4862 show print frame-arguments
4863 The value of this variable can be changed to control which argument
4864 values should be printed by the debugger when displaying a frame.
4869 Transfer files to and from a remote target, and delete remote files.
4876 Transfer files to and from a remote target, and delete remote files.
4878 * New remote packets
4885 Open, close, read, write, and delete files on the remote system.
4888 Attach to an existing process on the remote system, in extended-remote
4892 Run a new process on the remote system, in extended-remote mode.
4894 *** Changes in GDB 6.7
4896 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4897 bfd, libiberty and opcodes, as revealed by static analysis donated by
4898 Coverity, Inc. (http://scan.coverity.com).
4900 * When looking up multiply-defined global symbols, GDB will now prefer the
4901 symbol definition in the current shared library if it was built using the
4902 -Bsymbolic linker option.
4904 * When the Text User Interface (TUI) is not configured, GDB will now
4905 recognize the -tui command-line option and print a message that the TUI
4908 * The GDB remote stub, gdbserver, now has lower overhead for high
4909 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4911 * GDB for MIPS targets now autodetects whether a remote target provides
4912 32-bit or 64-bit register values.
4914 * Support for C++ member pointers has been improved.
4916 * GDB now understands XML target descriptions, which specify the
4917 target's overall architecture. GDB can read a description from
4918 a local file or over the remote serial protocol.
4920 * Vectors of single-byte data use a new integer type which is not
4921 automatically displayed as character or string data.
4923 * The /s format now works with the print command. It displays
4924 arrays of single-byte integers and pointers to single-byte integers
4927 * Target descriptions can now describe target-specific registers,
4928 for architectures which have implemented the support (currently
4929 only ARM, M68K, and MIPS).
4931 * GDB and the GDB remote stub, gdbserver, now support the XScale
4934 * The GDB remote stub, gdbserver, has been updated to support
4935 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4936 has been rewritten to use the standard GDB remote protocol.
4938 * GDB can now step into C++ functions which are called through thunks.
4940 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4942 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4943 layout. It also supports a TextSeg= and DataSeg= response when only
4944 segment base addresses (rather than offsets) are available.
4946 * The /i format now outputs any trailing branch delay slot instructions
4947 immediately following the last instruction within the count specified.
4949 * The GDB remote protocol "T" stop reply packet now supports a
4950 "library" response. Combined with the new "qXfer:libraries:read"
4951 packet, this response allows GDB to debug shared libraries on targets
4952 where the operating system manages the list of loaded libraries (e.g.
4953 Windows and SymbianOS).
4955 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4956 (DLLs) on Windows and Windows CE targets.
4958 * GDB now supports a faster verification that a .debug file matches its binary
4959 according to its build-id signature, if the signature is present.
4965 Enable or disable hardware flow control (RTS/CTS) on the serial port
4966 when debugging using remote targets.
4968 set mem inaccessible-by-default
4969 show mem inaccessible-by-default
4970 If the target supplies a memory map, for instance via the remote
4971 protocol's "qXfer:memory-map:read" packet, setting this variable
4972 prevents GDB from accessing memory outside the memory map. This
4973 is useful for targets with memory mapped registers or which react
4974 badly to accesses of unmapped address space.
4976 set breakpoint auto-hw
4977 show breakpoint auto-hw
4978 If the target supplies a memory map, for instance via the remote
4979 protocol's "qXfer:memory-map:read" packet, setting this variable
4980 lets GDB use hardware breakpoints automatically for memory regions
4981 where it can not use software breakpoints. This covers both the
4982 "break" command and internal breakpoints used for other commands
4983 including "next" and "finish".
4986 catch exception unhandled
4987 Stop the program execution when Ada exceptions are raised.
4990 Stop the program execution when an Ada assertion failed.
4994 Set an alternate system root for target files. This is a more
4995 general version of "set solib-absolute-prefix", which is now
4996 an alias to "set sysroot".
4999 Provide extended SPU facility status information. This set of
5000 commands is available only when debugging the Cell/B.E. SPU
5003 * New native configurations
5005 OpenBSD/sh sh*-*openbsd*
5008 unset tdesc filename
5010 Use the specified local file as an XML target description, and do
5011 not query the target for its built-in description.
5015 OpenBSD/sh sh*-*-openbsd*
5016 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5017 Toshiba Media Processor mep-elf
5019 * New remote packets
5022 Ignore the specified signals; pass them directly to the debugged program
5023 without stopping other threads or reporting them to GDB.
5025 qXfer:features:read:
5026 Read an XML target description from the target, which describes its
5031 Read or write contents of an spufs file on the target system. These
5032 packets are available only on the Cell/B.E. SPU architecture.
5034 qXfer:libraries:read:
5035 Report the loaded shared libraries. Combined with new "T" packet
5036 response, this packet allows GDB to debug shared libraries on
5037 targets where the operating system manages the list of loaded
5038 libraries (e.g. Windows and SymbianOS).
5042 Support for these obsolete configurations has been removed.
5050 i[34567]86-*-lynxos*
5051 i[34567]86-*-netware*
5052 i[34567]86-*-sco3.2v5*
5053 i[34567]86-*-sco3.2v4*
5055 i[34567]86-*-sysv4.2*
5058 i[34567]86-*-unixware2*
5059 i[34567]86-*-unixware*
5068 * Other removed features
5075 Various m68k-only ROM monitors.
5082 Various Renesas ROM monitors and debugging interfaces for SH and
5087 Support for a Macraigor serial interface to on-chip debugging.
5088 GDB does not directly support the newer parallel or USB
5093 A debug information format. The predecessor to DWARF 2 and
5094 DWARF 3, which are still supported.
5096 Support for the HP aCC compiler on HP-UX/PA-RISC
5098 SOM-encapsulated symbolic debugging information, automatic
5099 invocation of pxdb, and the aCC custom C++ ABI. This does not
5100 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5101 with aCC can still be debugged on an assembly level.
5103 MIPS ".pdr" sections
5105 A MIPS-specific format used to describe stack frame layout
5106 in debugging information.
5110 GDB could work with an older version of Guile to debug
5111 the interpreter and Scheme programs running in it.
5113 set mips stack-arg-size
5114 set mips saved-gpreg-size
5116 Use "set mips abi" to control parameter passing for MIPS.
5118 *** Changes in GDB 6.6
5123 Cell Broadband Engine SPU spu-elf
5125 * GDB can now be configured as a cross-debugger targeting native Windows
5126 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5127 running on a Windows system over TCP/IP to debug Windows programs.
5129 * The GDB remote stub, gdbserver, has been updated to support Windows and
5130 Cygwin debugging. Both single-threaded and multi-threaded programs are
5133 * The "set trust-readonly-sections" command works again. This command was
5134 broken in GDB 6.3, 6.4, and 6.5.
5136 * The "load" command now supports writing to flash memory, if the remote
5137 stub provides the required support.
5139 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5140 longer requires symbolic debug information (e.g. DWARF-2).
5145 unset substitute-path
5146 show substitute-path
5147 Manage a list of substitution rules that GDB uses to rewrite the name
5148 of the directories where the sources are located. This can be useful
5149 for instance when the sources were moved to a different location
5150 between compilation and debugging.
5154 Print each CLI command as it is executed. Each command is prefixed with
5155 a number of `+' symbols representing the nesting depth.
5156 The source command now has a `-v' option to enable the same feature.
5160 The ARM Demon monitor support (RDP protocol, "target rdp").
5162 Kernel Object Display, an embedded debugging feature which only worked with
5163 an obsolete version of Cisco IOS.
5165 The 'set download-write-size' and 'show download-write-size' commands.
5167 * New remote packets
5170 Tell a stub about GDB client features, and request remote target features.
5171 The first feature implemented is PacketSize, which allows the target to
5172 specify the size of packets it can handle - to minimize the number of
5173 packets required and improve performance when connected to a remote
5177 Fetch an OS auxilliary vector from the remote stub. This packet is a
5178 more efficient replacement for qPart:auxv:read.
5180 qXfer:memory-map:read:
5181 Fetch a memory map from the remote stub, including information about
5182 RAM, ROM, and flash memory devices.
5187 Erase and program a flash memory device.
5189 * Removed remote packets
5192 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5193 used it, and only gdbserver implemented it.
5195 *** Changes in GDB 6.5
5199 Renesas M32C/M16C m32c-elf
5201 Morpho Technologies ms1 ms1-elf
5205 init-if-undefined Initialize a convenience variable, but
5206 only if it doesn't already have a value.
5208 The following commands are presently only implemented for native GNU/Linux:
5210 checkpoint Save a snapshot of the program state.
5212 restart <n> Return the program state to a
5213 previously saved state.
5215 info checkpoints List currently saved checkpoints.
5217 delete-checkpoint <n> Delete a previously saved checkpoint.
5219 set|show detach-on-fork Tell gdb whether to detach from a newly
5220 forked process, or to keep debugging it.
5222 info forks List forks of the user program that
5223 are available to be debugged.
5225 fork <n> Switch to debugging one of several
5226 forks of the user program that are
5227 available to be debugged.
5229 delete-fork <n> Delete a fork from the list of forks
5230 that are available to be debugged (and
5231 kill the forked process).
5233 detach-fork <n> Delete a fork from the list of forks
5234 that are available to be debugged (and
5235 allow the process to continue).
5239 Morpho Technologies ms2 ms1-elf
5241 * Improved Windows host support
5243 GDB now builds as a cross debugger hosted on i686-mingw32, including
5244 native console support, and remote communications using either
5245 network sockets or serial ports.
5247 * Improved Modula-2 language support
5249 GDB can now print most types in the Modula-2 syntax. This includes:
5250 basic types, set types, record types, enumerated types, range types,
5251 pointer types and ARRAY types. Procedure var parameters are correctly
5252 printed and hexadecimal addresses and character constants are also
5253 written in the Modula-2 syntax. Best results can be obtained by using
5254 GNU Modula-2 together with the -gdwarf-2 command line option.
5258 The ARM rdi-share module.
5260 The Netware NLM debug server.
5262 *** Changes in GDB 6.4
5264 * New native configurations
5266 OpenBSD/arm arm*-*-openbsd*
5267 OpenBSD/mips64 mips64-*-openbsd*
5271 Morpho Technologies ms1 ms1-elf
5273 * New command line options
5275 --batch-silent As for --batch, but totally silent.
5276 --return-child-result The debugger will exist with the same value
5277 the child (debugged) program exited with.
5278 --eval-command COMMAND, -ex COMMAND
5279 Execute a single GDB CLI command. This may be
5280 specified multiple times and in conjunction
5281 with the --command (-x) option.
5283 * Deprecated commands removed
5285 The following commands, that were deprecated in 2000, have been
5289 set|show arm disassembly-flavor set|show arm disassembler
5290 othernames set arm disassembler
5291 set|show remotedebug set|show debug remote
5292 set|show archdebug set|show debug arch
5293 set|show eventdebug set|show debug event
5296 * New BSD user-level threads support
5298 It is now possible to debug programs using the user-level threads
5299 library on OpenBSD and FreeBSD. Currently supported (target)
5302 FreeBSD/amd64 x86_64-*-freebsd*
5303 FreeBSD/i386 i386-*-freebsd*
5304 OpenBSD/i386 i386-*-openbsd*
5306 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5307 are not yet supported.
5309 * New support for Matsushita MN10300 w/sim added
5310 (Work in progress). mn10300-elf.
5312 * REMOVED configurations and files
5314 VxWorks and the XDR protocol *-*-vxworks
5315 Motorola MCORE mcore-*-*
5316 National Semiconductor NS32000 ns32k-*-*
5318 * New "set print array-indexes" command
5320 After turning this setting "on", GDB prints the index of each element
5321 when displaying arrays. The default is "off" to preserve the previous
5324 * VAX floating point support
5326 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5328 * User-defined command support
5330 In addition to using $arg0..$arg9 for argument passing, it is now possible
5331 to use $argc to determine now many arguments have been passed. See the
5332 section on user-defined commands in the user manual for more information.
5334 *** Changes in GDB 6.3:
5336 * New command line option
5338 GDB now accepts -l followed by a number to set the timeout for remote
5341 * GDB works with GCC -feliminate-dwarf2-dups
5343 GDB now supports a more compact representation of DWARF-2 debug
5344 information using DW_FORM_ref_addr references. These are produced
5345 by GCC with the option -feliminate-dwarf2-dups and also by some
5346 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5347 to use -feliminate-dwarf2-dups.
5349 * Internationalization
5351 When supported by the host system, GDB will be built with
5352 internationalization (libintl). The task of marking up the sources is
5353 continued, we're looking forward to our first translation.
5357 Initial support for debugging programs compiled with the GNAT
5358 implementation of the Ada programming language has been integrated
5359 into GDB. In this release, support is limited to expression evaluation.
5361 * New native configurations
5363 GNU/Linux/m32r m32r-*-linux-gnu
5367 GDB's remote protocol now includes support for the 'p' packet. This
5368 packet is used to fetch individual registers from a remote inferior.
5370 * END-OF-LIFE registers[] compatibility module
5372 GDB's internal register infrastructure has been completely rewritten.
5373 The new infrastructure making possible the implementation of key new
5374 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5377 GDB 6.3 will be the last release to include the registers[]
5378 compatibility module that allowed out-of-date configurations to
5379 continue to work. This change directly impacts the following
5389 powerpc bdm protocol
5391 Unless there is activity to revive these configurations, they will be
5392 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5394 * OBSOLETE configurations and files
5396 Configurations that have been declared obsolete in this release have
5397 been commented out. Unless there is activity to revive these
5398 configurations, the next release of GDB will have their sources
5399 permanently REMOVED.
5408 *** Changes in GDB 6.2.1:
5410 * MIPS `break main; run' gave an heuristic-fence-post warning
5412 When attempting to run even a simple program, a warning about
5413 heuristic-fence-post being hit would be reported. This problem has
5416 * MIPS IRIX 'long double' crashed GDB
5418 When examining a long double variable, GDB would get a segmentation
5419 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5420 IRIX long double values).
5424 A bug in the VAX stack code was causing problems with the "next"
5425 command. This problem has been fixed.
5427 *** Changes in GDB 6.2:
5429 * Fix for ``many threads''
5431 On GNU/Linux systems that use the NPTL threads library, a program
5432 rapidly creating and deleting threads would confuse GDB leading to the
5435 ptrace: No such process.
5436 thread_db_get_info: cannot get thread info: generic error
5438 This problem has been fixed.
5440 * "-async" and "-noasync" options removed.
5442 Support for the broken "-noasync" option has been removed (it caused
5445 * New ``start'' command.
5447 This command runs the program until the beginning of the main procedure.
5449 * New BSD Kernel Data Access Library (libkvm) interface
5451 Using ``target kvm'' it is now possible to debug kernel core dumps and
5452 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5453 platforms. Currently supported (native-only) configurations are:
5455 FreeBSD/amd64 x86_64-*-freebsd*
5456 FreeBSD/i386 i?86-*-freebsd*
5457 NetBSD/i386 i?86-*-netbsd*
5458 NetBSD/m68k m68*-*-netbsd*
5459 NetBSD/sparc sparc-*-netbsd*
5460 OpenBSD/amd64 x86_64-*-openbsd*
5461 OpenBSD/i386 i?86-*-openbsd*
5462 OpenBSD/m68k m68*-openbsd*
5463 OpenBSD/sparc sparc-*-openbsd*
5465 * Signal trampoline code overhauled
5467 Many generic problems with GDB's signal handling code have been fixed.
5468 These include: backtraces through non-contiguous stacks; recognition
5469 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5470 call; backtrace through a signal trampoline; step into and out of
5471 signal handlers; and single-stepping in the signal trampoline.
5473 Please note that kernel bugs are a limiting factor here. These
5474 features have been shown to work on an s390 GNU/Linux system that
5475 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5477 * Cygwin support for DWARF 2 added.
5479 * New native configurations
5481 GNU/Linux/hppa hppa*-*-linux*
5482 OpenBSD/hppa hppa*-*-openbsd*
5483 OpenBSD/m68k m68*-*-openbsd*
5484 OpenBSD/m88k m88*-*-openbsd*
5485 OpenBSD/powerpc powerpc-*-openbsd*
5486 NetBSD/vax vax-*-netbsd*
5487 OpenBSD/vax vax-*-openbsd*
5489 * END-OF-LIFE frame compatibility module
5491 GDB's internal frame infrastructure has been completely rewritten.
5492 The new infrastructure making it possible to support key new features
5493 including DWARF 2 Call Frame Information. To aid in the task of
5494 migrating old configurations to this new infrastructure, a
5495 compatibility module, that allowed old configurations to continue to
5496 work, was also included.
5498 GDB 6.2 will be the last release to include this frame compatibility
5499 module. This change directly impacts the following configurations:
5509 Unless there is activity to revive these configurations, they will be
5510 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5512 * REMOVED configurations and files
5514 Sun 3, running SunOS 3 m68*-*-sunos3*
5515 Sun 3, running SunOS 4 m68*-*-sunos4*
5516 Sun 2, running SunOS 3 m68000-*-sunos3*
5517 Sun 2, running SunOS 4 m68000-*-sunos4*
5518 Motorola 680x0 running LynxOS m68*-*-lynxos*
5519 AT&T 3b1/Unix pc m68*-att-*
5520 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5521 decstation mips-dec-* mips-little-*
5522 riscos mips-*-riscos* mips-*-sysv*
5523 sonymips mips-sony-*
5524 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5526 *** Changes in GDB 6.1.1:
5528 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5530 The TUI (Text-mode User Interface) is now built as part of a default
5531 GDB configuration. It is enabled by either selecting the TUI with the
5532 command line option "-i=tui" or by running the separate "gdbtui"
5533 program. For more information on the TUI, see the manual "Debugging
5536 * Pending breakpoint support (also included in GDB 6.1)
5538 Support has been added to allow you to specify breakpoints in shared
5539 libraries that have not yet been loaded. If a breakpoint location
5540 cannot be found, and the "breakpoint pending" option is set to auto,
5541 GDB queries you if you wish to make the breakpoint pending on a future
5542 shared-library load. If and when GDB resolves the breakpoint symbol,
5543 the pending breakpoint is removed as one or more regular breakpoints
5546 Pending breakpoints are very useful for GCJ Java debugging.
5548 * Fixed ISO-C build problems
5550 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5551 non ISO-C code that stopped them being built using a more strict ISO-C
5552 compiler (e.g., IBM's C compiler).
5554 * Fixed build problem on IRIX 5
5556 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5557 wasn't able to compile compile on an IRIX 5 system.
5559 * Added execute permission to gdb/gdbserver/configure
5561 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5562 permission. This bug would cause configure to fail on a number of
5563 systems (Solaris, IRIX). Ref: server/519.
5565 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5567 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5568 has been updated to use constant array sizes.
5570 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5572 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5573 its generated DWARF Call Frame Info. This encoding was causing GDB to
5574 panic, that panic has been fixed. Ref: gdb/1628.
5576 * Fixed a problem when examining parameters in shared library code.
5578 When examining parameters in optimized shared library code generated
5579 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5580 not available''. GDB now correctly displays the variable's value.
5582 *** Changes in GDB 6.1:
5584 * Removed --with-mmalloc
5586 Support for the mmalloc memory manager has been removed, as it
5587 conflicted with the internal gdb byte cache.
5589 * Changes in AMD64 configurations
5591 The AMD64 target now includes the %cs and %ss registers. As a result
5592 the AMD64 remote protocol has changed; this affects the floating-point
5593 and SSE registers. If you rely on those registers for your debugging,
5594 you should upgrade gdbserver on the remote side.
5596 * Revised SPARC target
5598 The SPARC target has been completely revised, incorporating the
5599 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5600 support for LynxOS and SunOS 4 has been dropped. Calling functions
5601 from within GDB on operating systems with a non-executable stack
5602 (Solaris, OpenBSD) now works.
5606 GDB has a new C++ demangler which does a better job on the mangled
5607 names generated by current versions of g++. It also runs faster, so
5608 with this and other changes gdb should now start faster on large C++
5611 * DWARF 2 Location Expressions
5613 GDB support for location expressions has been extended to support function
5614 arguments and frame bases. Older versions of GDB could crash when they
5617 * C++ nested types and namespaces
5619 GDB's support for nested types and namespaces in C++ has been
5620 improved, especially if you use the DWARF 2 debugging format. (This
5621 is the default for recent versions of GCC on most platforms.)
5622 Specifically, if you have a class "Inner" defined within a class or
5623 namespace "Outer", then GDB realizes that the class's name is
5624 "Outer::Inner", not simply "Inner". This should greatly reduce the
5625 frequency of complaints about not finding RTTI symbols. In addition,
5626 if you are stopped at inside of a function defined within a namespace,
5627 GDB modifies its name lookup accordingly.
5629 * New native configurations
5631 NetBSD/amd64 x86_64-*-netbsd*
5632 OpenBSD/amd64 x86_64-*-openbsd*
5633 OpenBSD/alpha alpha*-*-openbsd*
5634 OpenBSD/sparc sparc-*-openbsd*
5635 OpenBSD/sparc64 sparc64-*-openbsd*
5637 * New debugging protocols
5639 M32R with SDI protocol m32r-*-elf*
5641 * "set prompt-escape-char" command deleted.
5643 The command "set prompt-escape-char" has been deleted. This command,
5644 and its very obscure effect on GDB's prompt, was never documented,
5645 tested, nor mentioned in the NEWS file.
5647 * OBSOLETE configurations and files
5649 Configurations that have been declared obsolete in this release have
5650 been commented out. Unless there is activity to revive these
5651 configurations, the next release of GDB will have their sources
5652 permanently REMOVED.
5654 Sun 3, running SunOS 3 m68*-*-sunos3*
5655 Sun 3, running SunOS 4 m68*-*-sunos4*
5656 Sun 2, running SunOS 3 m68000-*-sunos3*
5657 Sun 2, running SunOS 4 m68000-*-sunos4*
5658 Motorola 680x0 running LynxOS m68*-*-lynxos*
5659 AT&T 3b1/Unix pc m68*-att-*
5660 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5661 decstation mips-dec-* mips-little-*
5662 riscos mips-*-riscos* mips-*-sysv*
5663 sonymips mips-sony-*
5664 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5666 * REMOVED configurations and files
5668 SGI Irix-4.x mips-sgi-irix4 or iris4
5669 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5670 Z8000 simulator z8k-zilog-none or z8ksim
5671 Matsushita MN10200 w/simulator mn10200-*-*
5672 H8/500 simulator h8500-hitachi-hms or h8500hms
5673 HP/PA running BSD hppa*-*-bsd*
5674 HP/PA running OSF/1 hppa*-*-osf*
5675 HP/PA Pro target hppa*-*-pro*
5676 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5677 386BSD i[3456]86-*-bsd*
5678 Sequent family i[3456]86-sequent-sysv4*
5679 i[3456]86-sequent-sysv*
5680 i[3456]86-sequent-bsd*
5681 SPARC running LynxOS sparc-*-lynxos*
5682 SPARC running SunOS 4 sparc-*-sunos4*
5683 Tsqware Sparclet sparclet-*-*
5684 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5686 *** Changes in GDB 6.0:
5690 Support for debugging the Objective-C programming language has been
5691 integrated into GDB.
5693 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5695 DWARF 2's Call Frame Information makes available compiler generated
5696 information that more exactly describes the program's run-time stack.
5697 By using this information, GDB is able to provide more robust stack
5700 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5701 have been updated to use a new backtrace mechanism which includes
5702 DWARF 2 CFI support.
5706 GDB's remote protocol has been extended to include support for hosted
5707 file I/O (where the remote target uses GDB's file system). See GDB's
5708 remote protocol documentation for details.
5710 * All targets using the new architecture framework.
5712 All of GDB's targets have been updated to use the new internal
5713 architecture framework. The way is now open for future GDB releases
5714 to include cross-architecture native debugging support (i386 on amd64,
5717 * GNU/Linux's Thread Local Storage (TLS)
5719 GDB now includes support for for the GNU/Linux implementation of
5720 per-thread variables.
5722 * GNU/Linux's Native POSIX Thread Library (NPTL)
5724 GDB's thread code has been updated to work with either the new
5725 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5727 * Separate debug info.
5729 GDB, in conjunction with BINUTILS, now supports a mechanism for
5730 automatically loading debug information from a separate file. Instead
5731 of shipping full debug and non-debug versions of system libraries,
5732 system integrators can now instead ship just the stripped libraries
5733 and optional debug files.
5735 * DWARF 2 Location Expressions
5737 DWARF 2 Location Expressions allow the compiler to more completely
5738 describe the location of variables (even in optimized code) to the
5741 GDB now includes preliminary support for location expressions (support
5742 for DW_OP_piece is still missing).
5746 A number of long standing bugs that caused GDB to die while starting a
5747 Java application have been fixed. GDB's Java support is now
5748 considered "useable".
5750 * GNU/Linux support for fork, vfork, and exec.
5752 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5753 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5756 * GDB supports logging output to a file
5758 There are two new commands, "set logging" and "show logging", which can be
5759 used to capture GDB's output to a file.
5761 * The meaning of "detach" has changed for gdbserver
5763 The "detach" command will now resume the application, as documented. To
5764 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5767 * d10v, m68hc11 `regs' command deprecated
5769 The `info registers' command has been updated so that it displays the
5770 registers using a format identical to the old `regs' command.
5774 A new command, "maint set profile on/off", has been added. This command can
5775 be used to enable or disable profiling while running GDB, to profile a
5776 session or a set of commands. In addition there is a new configure switch,
5777 "--enable-profiling", which will cause GDB to be compiled with profiling
5778 data, for more informative profiling results.
5780 * Default MI syntax changed to "mi2".
5782 The default MI (machine interface) syntax, enabled by the command line
5783 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5784 "mi1", can be enabled by specifying the option "-i=mi1".
5786 Support for the original "mi0" syntax (included in GDB 5.0) has been
5789 Fix for gdb/192: removed extraneous space when displaying frame level.
5790 Fix for gdb/672: update changelist is now output in mi list format.
5791 Fix for gdb/702: a -var-assign that updates the value now shows up
5792 in a subsequent -var-update.
5794 * New native configurations.
5796 FreeBSD/amd64 x86_64-*-freebsd*
5798 * Multi-arched targets.
5800 HP/PA HPUX11 hppa*-*-hpux*
5801 Renesas M32R/D w/simulator m32r-*-elf*
5803 * OBSOLETE configurations and files
5805 Configurations that have been declared obsolete in this release have
5806 been commented out. Unless there is activity to revive these
5807 configurations, the next release of GDB will have their sources
5808 permanently REMOVED.
5810 Z8000 simulator z8k-zilog-none or z8ksim
5811 Matsushita MN10200 w/simulator mn10200-*-*
5812 H8/500 simulator h8500-hitachi-hms or h8500hms
5813 HP/PA running BSD hppa*-*-bsd*
5814 HP/PA running OSF/1 hppa*-*-osf*
5815 HP/PA Pro target hppa*-*-pro*
5816 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5817 Sequent family i[3456]86-sequent-sysv4*
5818 i[3456]86-sequent-sysv*
5819 i[3456]86-sequent-bsd*
5820 Tsqware Sparclet sparclet-*-*
5821 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5823 * REMOVED configurations and files
5826 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5827 IBM AIX PS/2 i[3456]86-*-aix
5828 i386 running Mach 3.0 i[3456]86-*-mach3*
5829 i386 running Mach i[3456]86-*-mach*
5830 i386 running OSF/1 i[3456]86-*osf1mk*
5831 HP/Apollo 68k Family m68*-apollo*-sysv*,
5833 m68*-hp-bsd*, m68*-hp-hpux*
5834 Argonaut Risc Chip (ARC) arc-*-*
5835 Mitsubishi D30V d30v-*-*
5836 Fujitsu FR30 fr30-*-elf*
5837 OS/9000 i[34]86-*-os9k
5838 I960 with MON960 i960-*-coff
5840 * MIPS $fp behavior changed
5842 The convenience variable $fp, for the MIPS, now consistently returns
5843 the address of the current frame's base. Previously, depending on the
5844 context, $fp could refer to either $sp or the current frame's base
5845 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5846 The GNU Source-Level Debugger''.
5848 *** Changes in GDB 5.3:
5850 * GNU/Linux shared library multi-threaded performance improved.
5852 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5853 `/proc', in preference to `ptrace' for memory reads. This may result
5854 in an improvement in the start-up time of multi-threaded, shared
5855 library applications when run under GDB. One GDB user writes: ``loads
5856 shared libs like mad''.
5858 * ``gdbserver'' now supports multi-threaded applications on some targets
5860 Support for debugging multi-threaded applications which use
5861 the GNU/Linux LinuxThreads package has been added for
5862 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5863 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5865 * GDB now supports C/C++ preprocessor macros.
5867 GDB now expands preprocessor macro invocations in C/C++ expressions,
5868 and provides various commands for showing macro definitions and how
5871 The new command `macro expand EXPRESSION' expands any macro
5872 invocations in expression, and shows the result.
5874 The new command `show macro MACRO-NAME' shows the definition of the
5875 macro named MACRO-NAME, and where it was defined.
5877 Most compilers don't include information about macros in the debugging
5878 information by default. In GCC 3.1, for example, you need to compile
5879 your program with the options `-gdwarf-2 -g3'. If the macro
5880 information is present in the executable, GDB will read it.
5882 * Multi-arched targets.
5884 DEC Alpha (partial) alpha*-*-*
5885 DEC VAX (partial) vax-*-*
5887 National Semiconductor NS32000 (partial) ns32k-*-*
5888 Motorola 68000 (partial) m68k-*-*
5889 Motorola MCORE mcore-*-*
5893 Fujitsu FRV architecture added by Red Hat frv*-*-*
5896 * New native configurations
5898 Alpha NetBSD alpha*-*-netbsd*
5899 SH NetBSD sh*-*-netbsdelf*
5900 MIPS NetBSD mips*-*-netbsd*
5901 UltraSPARC NetBSD sparc64-*-netbsd*
5903 * OBSOLETE configurations and files
5905 Configurations that have been declared obsolete in this release have
5906 been commented out. Unless there is activity to revive these
5907 configurations, the next release of GDB will have their sources
5908 permanently REMOVED.
5910 Mitsubishi D30V d30v-*-*
5911 OS/9000 i[34]86-*-os9k
5912 IBM AIX PS/2 i[3456]86-*-aix
5913 Fujitsu FR30 fr30-*-elf*
5914 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5915 Argonaut Risc Chip (ARC) arc-*-*
5916 i386 running Mach 3.0 i[3456]86-*-mach3*
5917 i386 running Mach i[3456]86-*-mach*
5918 i386 running OSF/1 i[3456]86-*osf1mk*
5919 HP/Apollo 68k Family m68*-apollo*-sysv*,
5921 m68*-hp-bsd*, m68*-hp-hpux*
5922 I960 with MON960 i960-*-coff
5924 * OBSOLETE languages
5926 CHILL, a Pascal like language used by telecommunications companies.
5928 * REMOVED configurations and files
5930 AMD 29k family via UDI a29k-amd-udi, udi29k
5931 A29K VxWorks a29k-*-vxworks
5932 AMD 29000 embedded, using EBMON a29k-none-none
5933 AMD 29000 embedded with COFF a29k-none-coff
5934 AMD 29000 embedded with a.out a29k-none-aout
5936 testsuite/gdb.hp/gdb.threads-hp/ directory
5938 * New command "set max-user-call-depth <nnn>"
5940 This command allows the user to limit the call depth of user-defined
5941 commands. The default is 1024.
5943 * Changes in FreeBSD/i386 native debugging.
5945 Support for the "generate-core-file" has been added.
5947 * New commands "dump", "append", and "restore".
5949 These commands allow data to be copied from target memory
5950 to a bfd-format or binary file (dump and append), and back
5951 from a file into memory (restore).
5953 * Improved "next/step" support on multi-processor Alpha Tru64.
5955 The previous single-step mechanism could cause unpredictable problems,
5956 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5957 of a software single-step mechanism prevents this.
5959 *** Changes in GDB 5.2.1:
5967 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5968 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5969 Fix, by Joel Brobecker imported from mainline.
5971 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5972 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5973 Fix, by Fred Fish, imported from mainline.
5975 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5976 Surprisingly enough, it works now.
5977 By Michal Ludvig, imported from mainline.
5979 i386 hardware watchpoint support:
5980 avoid misses on second run for some targets.
5981 By Pierre Muller, imported from mainline.
5983 *** Changes in GDB 5.2:
5985 * New command "set trust-readonly-sections on[off]".
5987 This command is a hint that tells gdb that read-only sections
5988 really are read-only (ie. that their contents will not change).
5989 In this mode, gdb will go to the object file rather than the
5990 target to read memory from read-only sections (such as ".text").
5991 This can be a significant performance improvement on some
5992 (notably embedded) targets.
5994 * New command "generate-core-file" (or "gcore").
5996 This new gdb command allows the user to drop a core file of the child
5997 process state at any time. So far it's been implemented only for
5998 GNU/Linux and Solaris, but should be relatively easily ported to other
5999 hosts. Argument is core file name (defaults to core.<pid>).
6001 * New command line option
6003 GDB now accepts --pid or -p followed by a process id.
6005 * Change in command line behavior -- corefiles vs. process ids.
6007 There is a subtle behavior in the way in which GDB handles
6008 command line arguments. The first non-flag argument is always
6009 a program to debug, but the second non-flag argument may either
6010 be a corefile or a process id. Previously, GDB would attempt to
6011 open the second argument as a corefile, and if that failed, would
6012 issue a superfluous error message and then attempt to attach it as
6013 a process. Now, if the second argument begins with a non-digit,
6014 it will be treated as a corefile. If it begins with a digit,
6015 GDB will attempt to attach it as a process, and if no such process
6016 is found, will then attempt to open it as a corefile.
6018 * Changes in ARM configurations.
6020 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6021 configuration is fully multi-arch.
6023 * New native configurations
6025 ARM NetBSD arm*-*-netbsd*
6026 x86 OpenBSD i[3456]86-*-openbsd*
6027 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6028 Sparc64 running FreeBSD sparc64-*-freebsd*
6032 Sanyo XStormy16 xstormy16-elf
6034 * OBSOLETE configurations and files
6036 Configurations that have been declared obsolete in this release have
6037 been commented out. Unless there is activity to revive these
6038 configurations, the next release of GDB will have their sources
6039 permanently REMOVED.
6041 AMD 29k family via UDI a29k-amd-udi, udi29k
6042 A29K VxWorks a29k-*-vxworks
6043 AMD 29000 embedded, using EBMON a29k-none-none
6044 AMD 29000 embedded with COFF a29k-none-coff
6045 AMD 29000 embedded with a.out a29k-none-aout
6047 testsuite/gdb.hp/gdb.threads-hp/ directory
6049 * REMOVED configurations and files
6051 TI TMS320C80 tic80-*-*
6053 PowerPC Solaris powerpcle-*-solaris*
6054 PowerPC Windows NT powerpcle-*-cygwin32
6055 PowerPC Netware powerpc-*-netware*
6056 Harris/CXUX m88k m88*-harris-cxux*
6057 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6058 ns32k-utek-sysv* ns32k-utek-*
6059 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6060 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6061 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6062 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6063 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6065 * Changes to command line processing
6067 The new `--args' feature can be used to specify command-line arguments
6068 for the inferior from gdb's command line.
6070 * Changes to key bindings
6072 There is a new `operate-and-get-next' function bound to `C-o'.
6074 *** Changes in GDB 5.1.1
6076 Fix compile problem on DJGPP.
6078 Fix a problem with floating-point registers on the i386 being
6081 Fix to stop GDB crashing on .debug_str debug info.
6083 Numerous documentation fixes.
6085 Numerous testsuite fixes.
6087 *** Changes in GDB 5.1:
6089 * New native configurations
6091 Alpha FreeBSD alpha*-*-freebsd*
6092 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6093 MIPS GNU/Linux mips*-*-linux*
6094 MIPS SGI Irix 6.x mips*-sgi-irix6*
6095 ia64 AIX ia64-*-aix*
6096 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6100 Motorola 68HC11 and 68HC12 m68hc11-elf
6102 UltraSparc running GNU/Linux sparc64-*-linux*
6104 * OBSOLETE configurations and files
6106 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6107 Harris/CXUX m88k m88*-harris-cxux*
6108 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6109 ns32k-utek-sysv* ns32k-utek-*
6110 TI TMS320C80 tic80-*-*
6112 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6113 PowerPC Solaris powerpcle-*-solaris*
6114 PowerPC Windows NT powerpcle-*-cygwin32
6115 PowerPC Netware powerpc-*-netware*
6116 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6117 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6118 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6119 Apple Macintosh (MPW) host N/A
6121 stuff.c (Program to stuff files into a specially prepared space in kdb)
6122 kdb-start.c (Main loop for the standalone kernel debugger)
6124 Configurations that have been declared obsolete in this release have
6125 been commented out. Unless there is activity to revive these
6126 configurations, the next release of GDB will have their sources
6127 permanently REMOVED.
6129 * REMOVED configurations and files
6131 Altos 3068 m68*-altos-*
6132 Convex c1-*-*, c2-*-*
6134 ARM RISCix arm-*-* (as host)
6138 * GDB has been converted to ISO C.
6140 GDB's source code has been converted to ISO C. In particular, the
6141 sources are fully protoized, and rely on standard headers being
6146 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6148 * The MI enabled by default.
6150 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6151 revised and enabled by default. Packages which use GDB as a debugging
6152 engine behind a UI or another front end are encouraged to switch to
6153 using the GDB/MI interface, instead of the old annotations interface
6154 which is now deprecated.
6156 * Support for debugging Pascal programs.
6158 GDB now includes support for debugging Pascal programs. The following
6159 main features are supported:
6161 - Pascal-specific data types such as sets;
6163 - automatic recognition of Pascal sources based on file-name
6166 - Pascal-style display of data types, variables, and functions;
6168 - a Pascal expression parser.
6170 However, some important features are not yet supported.
6172 - Pascal string operations are not supported at all;
6174 - there are some problems with boolean types;
6176 - Pascal type hexadecimal constants are not supported
6177 because they conflict with the internal variables format;
6179 - support for Pascal objects and classes is not full yet;
6181 - unlike Pascal, GDB is case-sensitive for symbol names.
6183 * Changes in completion.
6185 Commands such as `shell', `run' and `set args', which pass arguments
6186 to inferior programs, now complete on file names, similar to what
6187 users expect at the shell prompt.
6189 Commands which accept locations, such as `disassemble', `print',
6190 `breakpoint', `until', etc. now complete on filenames as well as
6191 program symbols. Thus, if you type "break foob TAB", and the source
6192 files linked into the programs include `foobar.c', that file name will
6193 be one of the candidates for completion. However, file names are not
6194 considered for completion after you typed a colon that delimits a file
6195 name from a name of a function in that file, as in "break foo.c:bar".
6197 `set demangle-style' completes on available demangling styles.
6199 * New platform-independent commands:
6201 It is now possible to define a post-hook for a command as well as a
6202 hook that runs before the command. For more details, see the
6203 documentation of `hookpost' in the GDB manual.
6205 * Changes in GNU/Linux native debugging.
6207 Support for debugging multi-threaded programs has been completely
6208 revised for all platforms except m68k and sparc. You can now debug as
6209 many threads as your system allows you to have.
6211 Attach/detach is supported for multi-threaded programs.
6213 Support for SSE registers was added for x86. This doesn't work for
6214 multi-threaded programs though.
6216 * Changes in MIPS configurations.
6218 Multi-arch support is enabled for all MIPS configurations.
6220 GDB can now be built as native debugger on SGI Irix 6.x systems for
6221 debugging n32 executables. (Debugging 64-bit executables is not yet
6224 * Unified support for hardware watchpoints in all x86 configurations.
6226 Most (if not all) native x86 configurations support hardware-assisted
6227 breakpoints and watchpoints in a unified manner. This support
6228 implements debug register sharing between watchpoints, which allows to
6229 put a virtually infinite number of watchpoints on the same address,
6230 and also supports watching regions up to 16 bytes with several debug
6233 The new maintenance command `maintenance show-debug-regs' toggles
6234 debugging print-outs in functions that insert, remove, and test
6235 watchpoints and hardware breakpoints.
6237 * Changes in the DJGPP native configuration.
6239 New command ``info dos sysinfo'' displays assorted information about
6240 the CPU, OS, memory, and DPMI server.
6242 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6243 display information about segment descriptors stored in GDT, LDT, and
6246 New commands ``info dos pde'' and ``info dos pte'' display entries
6247 from Page Directory and Page Tables (for now works with CWSDPMI only).
6248 New command ``info dos address-pte'' displays the Page Table entry for
6249 a given linear address.
6251 GDB can now pass command lines longer than 126 characters to the
6252 program being debugged (requires an update to the libdbg.a library
6253 which is part of the DJGPP development kit).
6255 DWARF2 debug info is now supported.
6257 It is now possible to `step' and `next' through calls to `longjmp'.
6259 * Changes in documentation.
6261 All GDB documentation was converted to GFDL, the GNU Free
6262 Documentation License.
6264 Tracepoints-related commands are now fully documented in the GDB
6267 TUI, the Text-mode User Interface, is now documented in the manual.
6269 Tracepoints-related commands are now fully documented in the GDB
6272 The "GDB Internals" manual now has an index. It also includes
6273 documentation of `ui_out' functions, GDB coding standards, x86
6274 hardware watchpoints, and memory region attributes.
6276 * GDB's version number moved to ``version.in''
6278 The Makefile variable VERSION has been replaced by the file
6279 ``version.in''. People creating GDB distributions should update the
6280 contents of this file.
6284 GUD support is now a standard part of the EMACS distribution.
6286 *** Changes in GDB 5.0:
6288 * Improved support for debugging FP programs on x86 targets
6290 Unified and much-improved support for debugging floating-point
6291 programs on all x86 targets. In particular, ``info float'' now
6292 displays the FP registers in the same format on all x86 targets, with
6293 greater level of detail.
6295 * Improvements and bugfixes in hardware-assisted watchpoints
6297 It is now possible to watch array elements, struct members, and
6298 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6299 on x86 targets no longer erroneously trigger when the address is
6302 * Improvements in the native DJGPP version of GDB
6304 The distribution now includes all the scripts and auxiliary files
6305 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6306 machines ``out of the box''.
6308 The DJGPP version can now debug programs that use signals. It is
6309 possible to catch signals that happened in the debuggee, deliver
6310 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6311 would kill the program being debugged.) Programs that hook hardware
6312 interrupts (keyboard, timer, etc.) can also be debugged.
6314 It is now possible to debug DJGPP programs that redirect their
6315 standard handles or switch them to raw (as opposed to cooked) mode, or
6316 even close them. The command ``run < foo > bar'' works as expected,
6317 and ``info terminal'' reports useful information about the debuggee's
6318 terminal, including raw/cooked mode, redirection, etc.
6320 The DJGPP version now uses termios functions for console I/O, which
6321 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6324 DOS-style file names with drive letters are now fully supported by
6327 It is now possible to debug DJGPP programs that switch their working
6328 directory. It is also possible to rerun the debuggee any number of
6329 times without restarting GDB; thus, you can use the same setup,
6330 breakpoints, etc. for many debugging sessions.
6332 * New native configurations
6334 ARM GNU/Linux arm*-*-linux*
6335 PowerPC GNU/Linux powerpc-*-linux*
6339 Motorola MCore mcore-*-*
6340 x86 VxWorks i[3456]86-*-vxworks*
6341 PowerPC VxWorks powerpc-*-vxworks*
6342 TI TMS320C80 tic80-*-*
6344 * OBSOLETE configurations
6346 Altos 3068 m68*-altos-*
6347 Convex c1-*-*, c2-*-*
6349 ARM RISCix arm-*-* (as host)
6352 Configurations that have been declared obsolete will be commented out,
6353 but the code will be left in place. If there is no activity to revive
6354 these configurations before the next release of GDB, the sources will
6355 be permanently REMOVED.
6357 * Gould support removed
6359 Support for the Gould PowerNode and NP1 has been removed.
6361 * New features for SVR4
6363 On SVR4 native platforms (such as Solaris), if you attach to a process
6364 without first loading a symbol file, GDB will now attempt to locate and
6365 load symbols from the running process's executable file.
6367 * Many C++ enhancements
6369 C++ support has been greatly improved. Overload resolution now works properly
6370 in almost all cases. RTTI support is on the way.
6372 * Remote targets can connect to a sub-program
6374 A popen(3) style serial-device has been added. This device starts a
6375 sub-process (such as a stand-alone simulator) and then communicates
6376 with that. The sub-program to run is specified using the syntax
6377 ``|<program> <args>'' vis:
6379 (gdb) set remotedebug 1
6380 (gdb) target extended-remote |mn10300-elf-sim program-args
6382 * MIPS 64 remote protocol
6384 A long standing bug in the mips64 remote protocol where by GDB
6385 expected certain 32 bit registers (ex SR) to be transfered as 32
6386 instead of 64 bits has been fixed.
6388 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6389 added to provide backward compatibility with older versions of GDB.
6391 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6393 The command ``set remotebinarydownload'' command has been replaced by
6394 ``set remote X-packet''. Other commands in ``set remote'' family
6395 include ``set remote P-packet''.
6397 * Breakpoint commands accept ranges.
6399 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6400 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6401 ``tracepoint passcount'' also accepts a range of tracepoints.
6403 * ``apropos'' command added.
6405 The ``apropos'' command searches through command names and
6406 documentation strings, printing out matches, making it much easier to
6407 try to find a command that does what you are looking for.
6411 A new machine oriented interface (MI) has been added to GDB. This
6412 interface is designed for debug environments running GDB as a separate
6413 process. This is part of the long term libGDB project. See the
6414 "GDB/MI" chapter of the GDB manual for further information. It can be
6415 enabled by configuring with:
6417 .../configure --enable-gdbmi
6419 *** Changes in GDB-4.18:
6421 * New native configurations
6423 HP-UX 10.20 hppa*-*-hpux10.20
6424 HP-UX 11.x hppa*-*-hpux11.0*
6425 M68K GNU/Linux m68*-*-linux*
6429 Fujitsu FR30 fr30-*-elf*
6430 Intel StrongARM strongarm-*-*
6431 Mitsubishi D30V d30v-*-*
6433 * OBSOLETE configurations
6435 Gould PowerNode, NP1 np1-*-*, pn-*-*
6437 Configurations that have been declared obsolete will be commented out,
6438 but the code will be left in place. If there is no activity to revive
6439 these configurations before the next release of GDB, the sources will
6440 be permanently REMOVED.
6444 As a compatibility experiment, GDB's source files buildsym.h and
6445 buildsym.c have been converted to pure standard C, no longer
6446 containing any K&R compatibility code. We believe that all systems in
6447 use today either come with a standard C compiler, or have a GCC port
6448 available. If this is not true, please report the affected
6449 configuration to bug-gdb@gnu.org immediately. See the README file for
6450 information about getting a standard C compiler if you don't have one
6455 GDB now uses readline 2.2.
6457 * set extension-language
6459 You can now control the mapping between filename extensions and source
6460 languages by using the `set extension-language' command. For instance,
6461 you can ask GDB to treat .c files as C++ by saying
6462 set extension-language .c c++
6463 The command `info extensions' lists all of the recognized extensions
6464 and their associated languages.
6466 * Setting processor type for PowerPC and RS/6000
6468 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6469 you can use the `set processor' command to specify what variant of the
6470 PowerPC family you are debugging. The command
6474 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6475 following PowerPC and RS6000 variants:
6477 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6478 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6480 403GC IBM PowerPC 403GC
6481 505 Motorola PowerPC 505
6482 860 Motorola PowerPC 860 or 850
6483 601 Motorola PowerPC 601
6484 602 Motorola PowerPC 602
6485 603 Motorola/IBM PowerPC 603 or 603e
6486 604 Motorola PowerPC 604 or 604e
6487 750 Motorola/IBM PowerPC 750 or 750
6489 At the moment, this command just tells GDB what to name the
6490 special-purpose processor registers. Since almost all the affected
6491 registers are inaccessible to user-level programs, this command is
6492 only useful for remote debugging in its present form.
6496 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6497 more extensive support for HP-UX. Added features include shared
6498 library support, kernel threads and hardware watchpoints for 11.00,
6499 support for HP's ANSI C and C++ compilers, and a compatibility mode
6500 for xdb and dbx commands.
6504 HP's donation includes the new concept of catchpoints, which is a
6505 generalization of the old catch command. On HP-UX, it is now possible
6506 to catch exec, fork, and vfork, as well as library loading.
6508 This means that the existing catch command has changed; its first
6509 argument now specifies the type of catch to be set up. See the
6510 output of "help catch" for a list of catchpoint types.
6512 * Debugging across forks
6514 On HP-UX, you can choose which process to debug when a fork() happens
6519 HP has donated a curses-based terminal user interface (TUI). To get
6520 it, build with --enable-tui. Although this can be enabled for any
6521 configuration, at present it only works for native HP debugging.
6523 * GDB remote protocol additions
6525 A new protocol packet 'X' that writes binary data is now available.
6526 Default behavior is to try 'X', then drop back to 'M' if the stub
6527 fails to respond. The settable variable `remotebinarydownload'
6528 allows explicit control over the use of 'X'.
6530 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6531 full 64-bit address. The command
6533 set remoteaddresssize 32
6535 can be used to revert to the old behaviour. For existing remote stubs
6536 the change should not be noticed, as the additional address information
6539 In order to assist in debugging stubs, you may use the maintenance
6540 command `packet' to send any text string to the stub. For instance,
6542 maint packet heythere
6544 sends the packet "$heythere#<checksum>". Note that it is very easy to
6545 disrupt a debugging session by sending the wrong packet at the wrong
6548 The compare-sections command allows you to compare section data on the
6549 target to what is in the executable file without uploading or
6550 downloading, by comparing CRC checksums.
6552 * Tracing can collect general expressions
6554 You may now collect general expressions at tracepoints. This requires
6555 further additions to the target-side stub; see tracepoint.c and
6556 doc/agentexpr.texi for further details.
6558 * mask-address variable for Mips
6560 For Mips targets, you may control the zeroing of the upper 32 bits of
6561 a 64-bit address by entering `set mask-address on'. This is mainly
6562 of interest to users of embedded R4xxx and R5xxx processors.
6564 * Higher serial baud rates
6566 GDB's serial code now allows you to specify baud rates 57600, 115200,
6567 230400, and 460800 baud. (Note that your host system may not be able
6568 to achieve all of these rates.)
6572 The i960 configuration now includes an initial implementation of a
6573 builtin simulator, contributed by Jim Wilson.
6576 *** Changes in GDB-4.17:
6578 * New native configurations
6580 Alpha GNU/Linux alpha*-*-linux*
6581 Unixware 2.x i[3456]86-unixware2*
6582 Irix 6.x mips*-sgi-irix6*
6583 PowerPC GNU/Linux powerpc-*-linux*
6584 PowerPC Solaris powerpcle-*-solaris*
6585 Sparc GNU/Linux sparc-*-linux*
6586 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6590 Argonaut Risc Chip (ARC) arc-*-*
6591 Hitachi H8/300S h8300*-*-*
6592 Matsushita MN10200 w/simulator mn10200-*-*
6593 Matsushita MN10300 w/simulator mn10300-*-*
6594 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6595 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6596 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6597 Mitsubishi D10V w/simulator d10v-*-*
6598 Mitsubishi M32R/D w/simulator m32r-*-elf*
6599 Tsqware Sparclet sparclet-*-*
6600 NEC V850 w/simulator v850-*-*
6602 * New debugging protocols
6604 ARM with RDI protocol arm*-*-*
6605 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6606 DDB and LSI variants of PMON protocol mips*-*-*
6607 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6608 PowerPC with SDS protocol powerpc{,le}-*-eabi
6609 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6613 All configurations can now understand and use the DWARF 2 debugging
6614 format. The choice is automatic, if the symbol file contains DWARF 2
6619 GDB now includes basic Java language support. This support is
6620 only useful with Java compilers that produce native machine code.
6622 * solib-absolute-prefix and solib-search-path
6624 For SunOS and SVR4 shared libraries, you may now set the prefix for
6625 loading absolute shared library symbol files, and the search path for
6626 locating non-absolute shared library symbol files.
6628 * Live range splitting
6630 GDB can now effectively debug code for which GCC has performed live
6631 range splitting as part of its optimization. See gdb/doc/LRS for
6632 more details on the expected format of the stabs information.
6636 GDB's support for the GNU Hurd, including thread debugging, has been
6637 updated to work with current versions of the Hurd.
6641 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6642 instruction set. ARM GDB automatically detects when Thumb
6643 instructions are in use, and adjusts disassembly and backtracing
6648 GDB's MIPS target configurations now handle the MIP16 16-bit
6653 GDB now includes support for overlays; if an executable has been
6654 linked such that multiple sections are based at the same address, GDB
6655 will decide which section to use for symbolic info. You can choose to
6656 control the decision manually, using overlay commands, or implement
6657 additional target-side support and use "overlay load-target" to bring
6658 in the overlay mapping. Do "help overlay" for more detail.
6662 The command "info symbol <address>" displays information about
6663 the symbol at the specified address.
6667 The standard remote protocol now includes an extension that allows
6668 asynchronous collection and display of trace data. This requires
6669 extensive support in the target-side debugging stub. Tracing mode
6670 includes a new interaction mode in GDB and new commands: see the
6671 file tracepoint.c for more details.
6675 Configurations for embedded MIPS now include a simulator contributed
6676 by Cygnus Solutions. The simulator supports the instruction sets
6677 of most MIPS variants.
6681 Sparc configurations may now include the ERC32 simulator contributed
6682 by the European Space Agency. The simulator is not built into
6683 Sparc targets by default; configure with --enable-sim to include it.
6687 For target configurations that may include multiple variants of a
6688 basic architecture (such as MIPS and SH), you may now set the
6689 architecture explicitly. "set arch" sets, "info arch" lists
6690 the possible architectures.
6692 *** Changes in GDB-4.16:
6694 * New native configurations
6696 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6697 M68K NetBSD m68k-*-netbsd*
6698 PowerPC AIX 4.x powerpc-*-aix*
6699 PowerPC MacOS powerpc-*-macos*
6700 PowerPC Windows NT powerpcle-*-cygwin32
6701 RS/6000 AIX 4.x rs6000-*-aix4*
6705 ARM with RDP protocol arm-*-*
6706 I960 with MON960 i960-*-coff
6707 MIPS VxWorks mips*-*-vxworks*
6708 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6709 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6711 Matra Sparclet sparclet-*-*
6715 The powerpc-eabi configuration now includes the PSIM simulator,
6716 contributed by Andrew Cagney, with assistance from Mike Meissner.
6717 PSIM is a very elaborate model of the PowerPC, including not only
6718 basic instruction set execution, but also details of execution unit
6719 performance and I/O hardware. See sim/ppc/README for more details.
6723 GDB now works with Solaris 2.5.
6725 * Windows 95/NT native
6727 GDB will now work as a native debugger on Windows 95 and Windows NT.
6728 To build it from source, you must use the "gnu-win32" environment,
6729 which uses a DLL to emulate enough of Unix to run the GNU tools.
6730 Further information, binaries, and sources are available at
6731 ftp.cygnus.com, under pub/gnu-win32.
6733 * dont-repeat command
6735 If a user-defined command includes the command `dont-repeat', then the
6736 command will not be repeated if the user just types return. This is
6737 useful if the command is time-consuming to run, so that accidental
6738 extra keystrokes don't run the same command many times.
6740 * Send break instead of ^C
6742 The standard remote protocol now includes an option to send a break
6743 rather than a ^C to the target in order to interrupt it. By default,
6744 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6746 * Remote protocol timeout
6748 The standard remote protocol includes a new variable `remotetimeout'
6749 that allows you to set the number of seconds before GDB gives up trying
6750 to read from the target. The default value is 2.
6752 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6754 By default GDB will automatically keep track of objects as they are
6755 loaded and unloaded by the dynamic linker. By using the command `set
6756 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6757 when shared library events occur, thus allowing you to set breakpoints
6758 in shared libraries which are explicitly loaded by the inferior.
6760 Note this feature does not work on hpux8. On hpux9 you must link
6761 /usr/lib/end.o into your program. This feature should work
6762 automatically on hpux10.
6764 * Irix 5.x hardware watchpoint support
6766 Irix 5 configurations now support the use of hardware watchpoints.
6768 * Mips protocol "SYN garbage limit"
6770 When debugging a Mips target using the `target mips' protocol, you
6771 may set the number of characters that GDB will ignore by setting
6772 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6773 every character. The default value is 1050.
6775 * Recording and replaying remote debug sessions
6777 If you set `remotelogfile' to the name of a file, gdb will write to it
6778 a recording of a remote debug session. This recording may then be
6779 replayed back to gdb using "gdbreplay". See gdbserver/README for
6780 details. This is useful when you have a problem with GDB while doing
6781 remote debugging; you can make a recording of the session and send it
6782 to someone else, who can then recreate the problem.
6784 * Speedups for remote debugging
6786 GDB includes speedups for downloading and stepping MIPS systems using
6787 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6788 and more efficient S-record downloading.
6790 * Memory use reductions and statistics collection
6792 GDB now uses less memory and reports statistics about memory usage.
6793 Try the `maint print statistics' command, for example.
6795 *** Changes in GDB-4.15:
6797 * Psymtabs for XCOFF
6799 The symbol reader for AIX GDB now uses partial symbol tables. This
6800 can greatly improve startup time, especially for large executables.
6802 * Remote targets use caching
6804 Remote targets now use a data cache to speed up communication with the
6805 remote side. The data cache could lead to incorrect results because
6806 it doesn't know about volatile variables, thus making it impossible to
6807 debug targets which use memory mapped I/O devices. `set remotecache
6808 off' turns the data cache off.
6810 * Remote targets may have threads
6812 The standard remote protocol now includes support for multiple threads
6813 in the target system, using new protocol commands 'H' and 'T'. See
6814 gdb/remote.c for details.
6818 If GDB is configured with `--enable-netrom', then it will include
6819 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6820 acts as though it is a bank of ROM on the target board, but you can
6821 write into it over the network. GDB's support consists only of
6822 support for fast loading into the emulated ROM; to debug, you must use
6823 another protocol, such as standard remote protocol. The usual
6824 sequence is something like
6826 target nrom <netrom-hostname>
6828 target remote <netrom-hostname>:1235
6832 GDB now includes support for the Apple Macintosh, as a host only. It
6833 may be run as either an MPW tool or as a standalone application, and
6834 it can debug through the serial port. All the usual GDB commands are
6835 available, but to the target command, you must supply "serial" as the
6836 device type instead of "/dev/ttyXX". See mpw-README in the main
6837 directory for more information on how to build. The MPW configuration
6838 scripts */mpw-config.in support only a few targets, and only the
6839 mips-idt-ecoff target has been tested.
6843 GDB configuration now uses autoconf. This is not user-visible,
6844 but does simplify configuration and building.
6848 GDB now supports hpux10.
6850 *** Changes in GDB-4.14:
6852 * New native configurations
6854 x86 FreeBSD i[345]86-*-freebsd
6855 x86 NetBSD i[345]86-*-netbsd
6856 NS32k NetBSD ns32k-*-netbsd
6857 Sparc NetBSD sparc-*-netbsd
6861 A29K VxWorks a29k-*-vxworks
6862 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6863 CPU32 EST-300 emulator m68*-*-est*
6864 PowerPC ELF powerpc-*-elf
6867 * Alpha OSF/1 support for procfs
6869 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6870 possible to attach to running processes. As the mounting of the /proc
6871 filesystem is optional on the Alpha, GDB automatically determines
6872 the availability of /proc during startup. This can lead to problems
6873 if /proc is unmounted after GDB has been started.
6875 * Arguments to user-defined commands
6877 User commands may accept up to 10 arguments separated by whitespace.
6878 Arguments are accessed within the user command via $arg0..$arg9. A
6881 print $arg0 + $arg1 + $arg2
6883 To execute the command use:
6886 Defines the command "adder" which prints the sum of its three arguments.
6887 Note the arguments are text substitutions, so they may reference variables,
6888 use complex expressions, or even perform inferior function calls.
6890 * New `if' and `while' commands
6892 This makes it possible to write more sophisticated user-defined
6893 commands. Both commands take a single argument, which is the
6894 expression to evaluate, and must be followed by the commands to
6895 execute, one per line, if the expression is nonzero, the list being
6896 terminated by the word `end'. The `if' command list may include an
6897 `else' word, which causes the following commands to be executed only
6898 if the expression is zero.
6900 * Fortran source language mode
6902 GDB now includes partial support for Fortran 77. It will recognize
6903 Fortran programs and can evaluate a subset of Fortran expressions, but
6904 variables and functions may not be handled correctly. GDB will work
6905 with G77, but does not yet know much about symbols emitted by other
6908 * Better HPUX support
6910 Most debugging facilities now work on dynamic executables for HPPAs
6911 running hpux9 or later. You can attach to running dynamically linked
6912 processes, but by default the dynamic libraries will be read-only, so
6913 for instance you won't be able to put breakpoints in them. To change
6914 that behavior do the following before running the program:
6920 This will cause the libraries to be mapped private and read-write.
6921 To revert to the normal behavior, do this:
6927 You cannot set breakpoints or examine data in the library until after
6928 the library is loaded if the function/data symbols do not have
6931 GDB can now also read debug symbols produced by the HP C compiler on
6932 HPPAs (sorry, no C++, Fortran or 68k support).
6934 * Target byte order now dynamically selectable
6936 You can choose which byte order to use with a target system, via the
6937 commands "set endian big" and "set endian little", and you can see the
6938 current setting by using "show endian". You can also give the command
6939 "set endian auto", in which case GDB will use the byte order
6940 associated with the executable. Currently, only embedded MIPS
6941 configurations support dynamic selection of target byte order.
6943 * New DOS host serial code
6945 This version uses DPMI interrupts to handle buffered I/O, so you
6946 no longer need to run asynctsr when debugging boards connected to
6949 *** Changes in GDB-4.13:
6951 * New "complete" command
6953 This lists all the possible completions for the rest of the line, if it
6954 were to be given as a command itself. This is intended for use by emacs.
6956 * Trailing space optional in prompt
6958 "set prompt" no longer adds a space for you after the prompt you set. This
6959 allows you to set a prompt which ends in a space or one that does not.
6961 * Breakpoint hit counts
6963 "info break" now displays a count of the number of times the breakpoint
6964 has been hit. This is especially useful in conjunction with "ignore"; you
6965 can ignore a large number of breakpoint hits, look at the breakpoint info
6966 to see how many times the breakpoint was hit, then run again, ignoring one
6967 less than that number, and this will get you quickly to the last hit of
6970 * Ability to stop printing at NULL character
6972 "set print null-stop" will cause GDB to stop printing the characters of
6973 an array when the first NULL is encountered. This is useful when large
6974 arrays actually contain only short strings.
6976 * Shared library breakpoints
6978 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6979 breakpoints in shared libraries before the executable is run.
6981 * Hardware watchpoints
6983 There is a new hardware breakpoint for the watch command for sparclite
6984 targets. See gdb/sparclite/hw_breakpoint.note.
6986 Hardware watchpoints are also now supported under GNU/Linux.
6990 Annotations have been added. These are for use with graphical interfaces,
6991 and are still experimental. Currently only gdba.el uses these.
6993 * Improved Irix 5 support
6995 GDB now works properly with Irix 5.2.
6997 * Improved HPPA support
6999 GDB now works properly with the latest GCC and GAS.
7001 * New native configurations
7003 Sequent PTX4 i[34]86-sequent-ptx4
7004 HPPA running OSF/1 hppa*-*-osf*
7005 Atari TT running SVR4 m68*-*-sysv4*
7006 RS/6000 LynxOS rs6000-*-lynxos*
7010 OS/9000 i[34]86-*-os9k
7011 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7014 * Hitachi SH7000 and E7000-PC ICE support
7016 There is now support for communicating with the Hitachi E7000-PC ICE.
7017 This is available automatically when GDB is configured for the SH.
7021 As usual, a variety of small fixes and improvements, both generic
7022 and configuration-specific. See the ChangeLog for more detail.
7024 *** Changes in GDB-4.12:
7026 * Irix 5 is now supported
7030 GDB-4.12 on the HPPA has a number of changes which make it unable
7031 to debug the output from the currently released versions of GCC and
7032 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7033 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7034 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7037 *** Changes in GDB-4.11:
7039 * User visible changes:
7043 The "set remotedebug" option is now consistent between the mips remote
7044 target, remote targets using the gdb-specific protocol, UDI (AMD's
7045 debug protocol for the 29k) and the 88k bug monitor. It is now an
7046 integer specifying a debug level (normally 0 or 1, but 2 means more
7047 debugging info for the mips target).
7049 * DEC Alpha native support
7051 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7052 debug info, but GDB works fairly well with the DEC compiler and should
7053 work with a future GCC release. See the README file for a few
7054 Alpha-specific notes.
7056 * Preliminary thread implementation
7058 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7060 * LynxOS native and target support for 386
7062 This release has been hosted on LynxOS 2.2, and also can be configured
7063 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7066 * Improvements in C++ mangling/demangling.
7068 This release has much better g++ debugging, specifically in name
7069 mangling/demangling, virtual function calls, print virtual table,
7070 call methods, ...etc.
7072 *** Changes in GDB-4.10:
7074 * User visible changes:
7076 Remote debugging using the GDB-specific (`target remote') protocol now
7077 supports the `load' command. This is only useful if you have some
7078 other way of getting the stub to the target system, and you can put it
7079 somewhere in memory where it won't get clobbered by the download.
7081 Filename completion now works.
7083 When run under emacs mode, the "info line" command now causes the
7084 arrow to point to the line specified. Also, "info line" prints
7085 addresses in symbolic form (as well as hex).
7087 All vxworks based targets now support a user settable option, called
7088 vxworks-timeout. This option represents the number of seconds gdb
7089 should wait for responses to rpc's. You might want to use this if
7090 your vxworks target is, perhaps, a slow software simulator or happens
7091 to be on the far side of a thin network line.
7095 This release contains support for using a DEC alpha as a GDB host for
7096 cross debugging. Native alpha debugging is not supported yet.
7099 *** Changes in GDB-4.9:
7103 This is the first GDB release which is accompanied by a matching testsuite.
7104 The testsuite requires installation of dejagnu, which should be available
7105 via ftp from most sites that carry GNU software.
7109 'Cfront' style demangling has had its name changed to 'ARM' style, to
7110 emphasize that it was written from the specifications in the C++ Annotated
7111 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7112 disclaimers, it still generated too much confusion with users attempting to
7113 use gdb with AT&T cfront.
7117 GDB now uses a standard remote interface to a simulator library.
7118 So far, the library contains simulators for the Zilog Z8001/2, the
7119 Hitachi H8/300, H8/500 and Super-H.
7121 * New targets supported
7123 H8/300 simulator h8300-hitachi-hms or h8300hms
7124 H8/500 simulator h8500-hitachi-hms or h8500hms
7125 SH simulator sh-hitachi-hms or sh
7126 Z8000 simulator z8k-zilog-none or z8ksim
7127 IDT MIPS board over serial line mips-idt-ecoff
7129 Cross-debugging to GO32 targets is supported. It requires a custom
7130 version of the i386-stub.c module which is integrated with the
7131 GO32 memory extender.
7133 * New remote protocols
7135 MIPS remote debugging protocol.
7137 * New source languages supported
7139 This version includes preliminary support for Chill, a Pascal like language
7140 used by telecommunications companies. Chill support is also being integrated
7141 into the GNU compiler, but we don't know when it will be publically available.
7144 *** Changes in GDB-4.8:
7146 * HP Precision Architecture supported
7148 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7149 version of this support was available as a set of patches from the
7150 University of Utah. GDB does not support debugging of programs
7151 compiled with the HP compiler, because HP will not document their file
7152 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7153 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7155 Many problems in the preliminary version have been fixed.
7157 * Faster and better demangling
7159 We have improved template demangling and fixed numerous bugs in the GNU style
7160 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7161 character types (wchar_t) are now supported. Demangling of each symbol is now
7162 only done once, and is cached when the symbol table for a file is read in.
7163 This results in a small increase in memory usage for C programs, a moderate
7164 increase in memory usage for C++ programs, and a fantastic speedup in
7167 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7168 from the specifications in the Annotated Reference Manual, which AT&T's
7169 compiler does not actually implement.
7171 * G++ multiple inheritance compiler problem
7173 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7174 inheritance lattices was reworked to properly discover ambiguities. We
7175 recently found an example which causes this new algorithm to fail in a
7176 very subtle way, producing bad debug information for those classes.
7177 The file 'gcc.patch' (in this directory) can be applied to gcc to
7178 circumvent the problem. A future GCC release will contain a complete
7181 The previous G++ debug info problem (mentioned below for the gdb-4.7
7182 release) is fixed in gcc version 2.3.2.
7184 * Improved configure script
7186 The `configure' script will now attempt to guess your system type if
7187 you don't supply a host system type. The old scheme of supplying a
7188 host system triplet is preferable over using this. All the magic is
7189 done in the new `config.guess' script. Examine it for details.
7191 We have also brought our configure script much more in line with the FSF's
7192 version. It now supports the --with-xxx options. In particular,
7193 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7194 The resulting GDB will not be able to read arbitrary object file formats --
7195 only the format ``expected'' to be used on the configured target system.
7196 We hope to make this the default in a future release.
7198 * Documentation improvements
7200 There's new internal documentation on how to modify GDB, and how to
7201 produce clean changes to the code. We implore people to read it
7202 before submitting changes.
7204 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7205 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7206 `info' files are also provided. To build `info' files from scratch,
7207 you will need the latest `makeinfo' release, which will be available in
7208 a future texinfo-X.Y release.
7210 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7211 We're not sure exactly which versions have this problem, but it has
7212 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7213 or better. If that isn't possible, there is a patch in
7214 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7215 around this problem.
7219 GDB now supports array constants that can be used in expressions typed in by
7220 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7221 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7224 The new directory `gdb/sparclite' contains a program that demonstrates
7225 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7227 * New native hosts supported
7229 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7230 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7232 * New targets supported
7234 AMD 29k family via UDI a29k-amd-udi or udi29k
7236 * New file formats supported
7238 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7239 HPUX core files, and SCO 3.2v2 core files.
7243 Attaching to processes now works again; thanks for the many bug reports.
7245 We have also stomped on a bunch of core dumps caused by
7246 printf_filtered("%s") problems.
7248 We eliminated a copyright problem on the rpc and ptrace header files
7249 for VxWorks, which was discovered at the last minute during the 4.7
7250 release. You should now be able to build a VxWorks GDB.
7252 You can now interrupt gdb while an attached process is running. This
7253 will cause the attached process to stop, and give control back to GDB.
7255 We fixed problems caused by using too many file descriptors
7256 for reading symbols from object files and libraries. This was
7257 especially a problem for programs that used many (~100) shared
7260 The `step' command now only enters a subroutine if there is line number
7261 information for the subroutine. Otherwise it acts like the `next'
7262 command. Previously, `step' would enter subroutines if there was
7263 any debugging information about the routine. This avoids problems
7264 when using `cc -g1' on MIPS machines.
7266 * Internal improvements
7268 GDB's internal interfaces have been improved to make it easier to support
7269 debugging of multiple languages in the future.
7271 GDB now uses a common structure for symbol information internally.
7272 Minimal symbols (derived from linkage symbols in object files), partial
7273 symbols (from a quick scan of debug information), and full symbols
7274 contain a common subset of information, making it easier to write
7275 shared code that handles any of them.
7277 * New command line options
7279 We now accept --silent as an alias for --quiet.
7283 The memory-mapped-malloc library is now licensed under the GNU Library
7284 General Public License.
7286 *** Changes in GDB-4.7:
7288 * Host/native/target split
7290 GDB has had some major internal surgery to untangle the support for
7291 hosts and remote targets. Now, when you configure GDB for a remote
7292 target, it will no longer load in all of the support for debugging
7293 local programs on the host. When fully completed and tested, this will
7294 ensure that arbitrary host/target combinations are possible.
7296 The primary conceptual shift is to separate the non-portable code in
7297 GDB into three categories. Host specific code is required any time GDB
7298 is compiled on that host, regardless of the target. Target specific
7299 code relates to the peculiarities of the target, but can be compiled on
7300 any host. Native specific code is everything else: it can only be
7301 built when the host and target are the same system. Child process
7302 handling and core file support are two common `native' examples.
7304 GDB's use of /proc for controlling Unix child processes is now cleaner.
7305 It has been split out into a single module under the `target_ops' vector,
7306 plus two native-dependent functions for each system that uses /proc.
7308 * New hosts supported
7310 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7311 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7312 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7314 * New targets supported
7316 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7317 68030 and CPU32 m68030-*-*, m68332-*-*
7319 * New native hosts supported
7321 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7322 (386bsd is not well tested yet)
7323 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7325 * New file formats supported
7327 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7328 supports reading of `a.out.adobe' object files, which are an a.out
7329 format extended with minimal information about multiple sections.
7333 `show copying' is the same as the old `info copying'.
7334 `show warranty' is the same as `info warrantee'.
7335 These were renamed for consistency. The old commands continue to work.
7337 `info handle' is a new alias for `info signals'.
7339 You can now define pre-command hooks, which attach arbitrary command
7340 scripts to any command. The commands in the hook will be executed
7341 prior to the user's command. You can also create a hook which will be
7342 executed whenever the program stops. See gdb.texinfo.
7346 We now deal with Cfront style name mangling, and can even extract type
7347 info from mangled symbols. GDB can automatically figure out which
7348 symbol mangling style your C++ compiler uses.
7350 Calling of methods and virtual functions has been improved as well.
7354 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7355 fixed. This was due to mishandling of the extra N_SO stabs output
7358 We also finally got Ultrix 4.2 running in house, and fixed core file
7359 support, with help from a dozen people on the net.
7361 John M. Farrell discovered that the reason that single-stepping was so
7362 slow on all of the Mips based platforms (primarily SGI and DEC) was
7363 that we were trying to demangle and lookup a symbol used for internal
7364 purposes on every instruction that was being stepped through. Changing
7365 the name of that symbol so that it couldn't be mistaken for a C++
7366 mangled symbol sped things up a great deal.
7368 Rich Pixley sped up symbol lookups in general by getting much smarter
7369 about when C++ symbol mangling is necessary. This should make symbol
7370 completion (TAB on the command line) much faster. It's not as fast as
7371 we'd like, but it's significantly faster than gdb-4.6.
7375 A new user controllable variable 'call_scratch_address' can
7376 specify the location of a scratch area to be used when GDB
7377 calls a function in the target. This is necessary because the
7378 usual method of putting the scratch area on the stack does not work
7379 in systems that have separate instruction and data spaces.
7381 We integrated changes to support the 29k UDI (Universal Debugger
7382 Interface), but discovered at the last minute that we didn't have all
7383 of the appropriate copyright paperwork. We are working with AMD to
7384 resolve this, and hope to have it available soon.
7388 We have sped up the remote serial line protocol, especially for targets
7389 with lots of registers. It now supports a new `expedited status' ('T')
7390 message which can be used in place of the existing 'S' status message.
7391 This allows the remote stub to send only the registers that GDB
7392 needs to make a quick decision about single-stepping or conditional
7393 breakpoints, eliminating the need to fetch the entire register set for
7394 each instruction being stepped through.
7396 The GDB remote serial protocol now implements a write-through cache for
7397 registers, only re-reading the registers if the target has run.
7399 There is also a new remote serial stub for SPARC processors. You can
7400 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7401 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7402 processor with a serial port.
7406 Configure.in files have become much easier to read and modify. A new
7407 `table driven' format makes it more obvious what configurations are
7408 supported, and what files each one uses.
7412 There is a new opcodes library which will eventually contain all of the
7413 disassembly routines and opcode tables. At present, it only contains
7414 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7415 disassembler (binutils/objdump) to share these routines.
7417 The libiberty library is now copylefted under the GNU Library General
7418 Public License. This allows more liberal use, and was done so libg++
7419 can use it. This makes no difference to GDB, since the Library License
7420 grants all the rights from the General Public License.
7424 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7425 reference to the stabs symbol info used by the debugger. It is (as far
7426 as we know) the only published document on this fascinating topic. We
7427 encourage you to read it, compare it to the stabs information on your
7428 system, and send improvements on the document in general (to
7429 bug-gdb@prep.ai.mit.edu).
7431 And, of course, many bugs have been fixed.
7434 *** Changes in GDB-4.6:
7436 * Better support for C++ function names
7438 GDB now accepts as input the "demangled form" of C++ overloaded function
7439 names and member function names, and can do command completion on such names
7440 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7441 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7442 Make use of command completion, it is your friend.
7444 GDB also now accepts a variety of C++ mangled symbol formats. They are
7445 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7446 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7447 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7448 for the list of formats.
7450 * G++ symbol mangling problem
7452 Recent versions of gcc have a bug in how they emit debugging information for
7453 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7454 directory) can be applied to gcc to fix the problem. Alternatively, if you
7455 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7456 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7457 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7460 * New 'maintenance' command
7462 All of the commands related to hacking GDB internals have been moved out of
7463 the main command set, and now live behind the 'maintenance' command. This
7464 can also be abbreviated as 'mt'. The following changes were made:
7466 dump-me -> maintenance dump-me
7467 info all-breakpoints -> maintenance info breakpoints
7468 printmsyms -> maintenance print msyms
7469 printobjfiles -> maintenance print objfiles
7470 printpsyms -> maintenance print psymbols
7471 printsyms -> maintenance print symbols
7473 The following commands are new:
7475 maintenance demangle Call internal GDB demangler routine to
7476 demangle a C++ link name and prints the result.
7477 maintenance print type Print a type chain for a given symbol
7479 * Change to .gdbinit file processing
7481 We now read the $HOME/.gdbinit file before processing the argv arguments
7482 (e.g. reading symbol files or core files). This allows global parameters to
7483 be set, which will apply during the symbol reading. The ./.gdbinit is still
7484 read after argv processing.
7486 * New hosts supported
7488 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7490 GNU/Linux support i386-unknown-linux or linux
7492 We are also including code to support the HP/PA running BSD and HPUX. This
7493 is almost guaranteed not to work, as we didn't have time to test or build it
7494 for this release. We are including it so that the more adventurous (or
7495 masochistic) of you can play with it. We also had major problems with the
7496 fact that the compiler that we got from HP doesn't support the -g option.
7499 * New targets supported
7501 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7503 * More smarts about finding #include files
7505 GDB now remembers the compilation directory for all include files, and for
7506 all files from which C is generated (like yacc and lex sources). This
7507 greatly improves GDB's ability to find yacc/lex sources, and include files,
7508 especially if you are debugging your program from a directory different from
7509 the one that contains your sources.
7511 We also fixed a bug which caused difficulty with listing and setting
7512 breakpoints in include files which contain C code. (In the past, you had to
7513 try twice in order to list an include file that you hadn't looked at before.)
7515 * Interesting infernals change
7517 GDB now deals with arbitrary numbers of sections, where the symbols for each
7518 section must be relocated relative to that section's landing place in the
7519 target's address space. This work was needed to support ELF with embedded
7520 stabs used by Solaris-2.0.
7522 * Bug fixes (of course!)
7524 There have been loads of fixes for the following things:
7525 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7526 i960, stabs, DOS(GO32), procfs, etc...
7528 See the ChangeLog for details.
7530 *** Changes in GDB-4.5:
7532 * New machines supported (host and target)
7534 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7536 SGI Irix-4.x mips-sgi-irix4 or iris4
7538 * New malloc package
7540 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7541 Mmalloc is capable of handling multiple heaps of memory. It is also
7542 capable of saving a heap to a file, and then mapping it back in later.
7543 This can be used to greatly speedup the startup of GDB by using a
7544 pre-parsed symbol table which lives in a mmalloc managed heap. For
7545 more details, please read mmalloc/mmalloc.texi.
7549 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7550 'help info proc' for details.
7552 * MIPS ecoff symbol table format
7554 The code that reads MIPS symbol table format is now supported on all hosts.
7555 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7558 * File name changes for MS-DOS
7560 Many files in the config directories have been renamed to make it easier to
7561 support GDB on MS-DOSe systems (which have very restrictive file name
7562 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7563 environment) is close to working but has some remaining problems. Note
7564 that debugging of DOS programs is not supported, due to limitations
7565 in the ``operating system'', but it can be used to host cross-debugging.
7567 * Cross byte order fixes
7569 Many fixes have been made to support cross debugging of Sparc and MIPS
7570 targets from hosts whose byte order differs.
7572 * New -mapped and -readnow options
7574 If memory-mapped files are available on your system through the 'mmap'
7575 system call, you can use the -mapped option on the `file' or
7576 `symbol-file' commands to cause GDB to write the symbols from your
7577 program into a reusable file. If the program you are debugging is
7578 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7579 Future GDB debugging sessions will notice the presence of this file,
7580 and will quickly map in symbol information from it, rather than reading
7581 the symbol table from the executable program. Using the '-mapped'
7582 option in a GDB `file' or `symbol-file' command has the same effect as
7583 starting GDB with the '-mapped' command-line option.
7585 You can cause GDB to read the entire symbol table immediately by using
7586 the '-readnow' option with any of the commands that load symbol table
7587 information (or on the GDB command line). This makes the command
7588 slower, but makes future operations faster.
7590 The -mapped and -readnow options are typically combined in order to
7591 build a `fred.syms' file that contains complete symbol information.
7592 A simple GDB invocation to do nothing but build a `.syms' file for future
7595 gdb -batch -nx -mapped -readnow programname
7597 The `.syms' file is specific to the host machine on which GDB is run.
7598 It holds an exact image of GDB's internal symbol table. It cannot be
7599 shared across multiple host platforms.
7601 * longjmp() handling
7603 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7604 siglongjmp() without losing control. This feature has not yet been ported to
7605 all systems. It currently works on many 386 platforms, all MIPS-based
7606 platforms (SGI, DECstation, etc), and Sun3/4.
7610 Preliminary work has been put in to support the new Solaris OS from Sun. At
7611 this time, it can control and debug processes, but it is not capable of
7616 As always, many many bug fixes. The major areas were with g++, and mipsread.
7617 People using the MIPS-based platforms should experience fewer mysterious
7618 crashes and trashed symbol tables.
7620 *** Changes in GDB-4.4:
7622 * New machines supported (host and target)
7624 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7626 BSD Reno on Vax vax-dec-bsd
7627 Ultrix on Vax vax-dec-ultrix
7629 * New machines supported (target)
7631 AMD 29000 embedded, using EBMON a29k-none-none
7635 GDB continues to improve its handling of C++. `References' work better.
7636 The demangler has also been improved, and now deals with symbols mangled as
7637 per the Annotated C++ Reference Guide.
7639 GDB also now handles `stabs' symbol information embedded in MIPS
7640 `ecoff' symbol tables. Since the ecoff format was not easily
7641 extensible to handle new languages such as C++, this appeared to be a
7642 good way to put C++ debugging info into MIPS binaries. This option
7643 will be supported in the GNU C compiler, version 2, when it is
7646 * New features for SVR4
7648 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7649 shared libraries. Debugging dynamically linked programs should present
7650 only minor differences from debugging statically linked programs.
7652 The `info proc' command will print out information about any process
7653 on an SVR4 system (including the one you are debugging). At the moment,
7654 it prints the address mappings of the process.
7656 If you bring up GDB on another SVR4 system, please send mail to
7657 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7659 * Better dynamic linking support in SunOS
7661 Reading symbols from shared libraries which contain debugging symbols
7662 now works properly. However, there remain issues such as automatic
7663 skipping of `transfer vector' code during function calls, which
7664 make it harder to debug code in a shared library, than to debug the
7665 same code linked statically.
7669 GDB is now using the latest `getopt' routines from the FSF. This
7670 version accepts the -- prefix for options with long names. GDB will
7671 continue to accept the old forms (-option and +option) as well.
7672 Various single letter abbreviations for options have been explicity
7673 added to the option table so that they won't get overshadowed in the
7674 future by other options that begin with the same letter.
7678 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7679 Many assorted bugs have been handled. Many more remain to be handled.
7680 See the various ChangeLog files (primarily in gdb and bfd) for details.
7683 *** Changes in GDB-4.3:
7685 * New machines supported (host and target)
7687 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7688 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7689 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7691 * Almost SCO Unix support
7693 We had hoped to support:
7694 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7695 (except for core file support), but we discovered very late in the release
7696 that it has problems with process groups that render gdb unusable. Sorry
7697 about that. I encourage people to fix it and post the fixes.
7699 * Preliminary ELF and DWARF support
7701 GDB can read ELF object files on System V Release 4, and can handle
7702 debugging records for C, in DWARF format, in ELF files. This support
7703 is preliminary. If you bring up GDB on another SVR4 system, please
7704 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7709 GDB now uses the latest `readline' library. One user-visible change
7710 is that two tabs will list possible command completions, which previously
7711 required typing M-? (meta-question mark, or ESC ?).
7715 The `stepi' bug that many of you noticed has been squashed.
7716 Many bugs in C++ have been handled. Many more remain to be handled.
7717 See the various ChangeLog files (primarily in gdb and bfd) for details.
7719 * State of the MIPS world (in case you wondered):
7721 GDB can understand the symbol tables emitted by the compilers
7722 supplied by most vendors of MIPS-based machines, including DEC. These
7723 symbol tables are in a format that essentially nobody else uses.
7725 Some versions of gcc come with an assembler post-processor called
7726 mips-tfile. This program is required if you want to do source-level
7727 debugging of gcc-compiled programs. I believe FSF does not ship
7728 mips-tfile with gcc version 1, but it will eventually come with gcc
7731 Debugging of g++ output remains a problem. g++ version 1.xx does not
7732 really support it at all. (If you're lucky, you should be able to get
7733 line numbers and stack traces to work, but no parameters or local
7734 variables.) With some work it should be possible to improve the
7737 When gcc version 2 is released, you will have somewhat better luck.
7738 However, even then you will get confusing results for inheritance and
7741 We will eventually provide full debugging of g++ output on
7742 DECstations. This will probably involve some kind of stabs-in-ecoff
7743 encapulation, but the details have not been worked out yet.
7746 *** Changes in GDB-4.2:
7748 * Improved configuration
7750 Only one copy of `configure' exists now, and it is not self-modifying.
7751 Porting BFD is simpler.
7755 The `step' and `next' commands now only stop at the first instruction
7756 of a source line. This prevents the multiple stops that used to occur
7757 in switch statements, for-loops, etc. `Step' continues to stop if a
7758 function that has debugging information is called within the line.
7762 Lots of small bugs fixed. More remain.
7764 * New host supported (not target)
7766 Intel 386 PC clone running Mach i386-none-mach
7769 *** Changes in GDB-4.1:
7771 * Multiple source language support
7773 GDB now has internal scaffolding to handle several source languages.
7774 It determines the type of each source file from its filename extension,
7775 and will switch expression parsing and number formatting to match the
7776 language of the function in the currently selected stack frame.
7777 You can also specifically set the language to be used, with
7778 `set language c' or `set language modula-2'.
7782 GDB now has preliminary support for the GNU Modula-2 compiler,
7783 currently under development at the State University of New York at
7784 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7785 continue through the fall of 1991 and into 1992.
7787 Other Modula-2 compilers are currently not supported, and attempting to
7788 debug programs compiled with them will likely result in an error as the
7789 symbol table is read. Feel free to work on it, though!
7791 There are hooks in GDB for strict type checking and range checking,
7792 in the `Modula-2 philosophy', but they do not currently work.
7796 GDB can now write to executable and core files (e.g. patch
7797 a variable's value). You must turn this switch on, specify
7798 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7799 by assigning a new value to a variable. Modifications take
7802 * Automatic SunOS shared library reading
7804 When you run your program, GDB automatically determines where its
7805 shared libraries (if any) have been loaded, and reads their symbols.
7806 The `share' command is no longer needed. This also works when
7807 examining core files.
7811 You can specify the number of lines that the `list' command shows.
7814 * New machines supported (host and target)
7816 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7817 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7818 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7820 * New hosts supported (not targets)
7822 IBM RT/PC: romp-ibm-aix or rtpc
7824 * New targets supported (not hosts)
7826 AMD 29000 embedded with COFF a29k-none-coff
7827 AMD 29000 embedded with a.out a29k-none-aout
7828 Ultracomputer remote kernel debug a29k-nyu-kern
7830 * New remote interfaces
7836 *** Changes in GDB-4.0:
7840 Wide output is wrapped at good places to make the output more readable.
7842 Gdb now supports cross-debugging from a host machine of one type to a
7843 target machine of another type. Communication with the target system
7844 is over serial lines. The ``target'' command handles connecting to the
7845 remote system; the ``load'' command will download a program into the
7846 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7847 also supports debugging of realtime processes running under VxWorks,
7848 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7849 stub on the target system.
7851 New CPUs supported include the AMD 29000 and Intel 960.
7853 GDB now reads object files and symbol tables via a ``binary file''
7854 library, which allows a single copy of GDB to debug programs of multiple
7855 object file types such as a.out and coff.
7857 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7858 refcard.dvi and refcard.ps are available to format it).
7861 * Control-Variable user interface simplified
7863 All variables that control the operation of the debugger can be set
7864 by the ``set'' command, and displayed by the ``show'' command.
7866 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7867 ``Show prompt'' produces the response:
7868 Gdb's prompt is new-gdb=>.
7870 What follows are the NEW set commands. The command ``help set'' will
7871 print a complete list of old and new set commands. ``help set FOO''
7872 will give a longer description of the variable FOO. ``show'' will show
7873 all of the variable descriptions and their current settings.
7875 confirm on/off: Enables warning questions for operations that are
7876 hard to recover from, e.g. rerunning the program while
7877 it is already running. Default is ON.
7879 editing on/off: Enables EMACS style command line editing
7880 of input. Previous lines can be recalled with
7881 control-P, the current line can be edited with control-B,
7882 you can search for commands with control-R, etc.
7885 history filename NAME: NAME is where the gdb command history
7886 will be stored. The default is .gdb_history,
7887 or the value of the environment variable
7890 history size N: The size, in commands, of the command history. The
7891 default is 256, or the value of the environment variable
7894 history save on/off: If this value is set to ON, the history file will
7895 be saved after exiting gdb. If set to OFF, the
7896 file will not be saved. The default is OFF.
7898 history expansion on/off: If this value is set to ON, then csh-like
7899 history expansion will be performed on
7900 command line input. The default is OFF.
7902 radix N: Sets the default radix for input and output. It can be set
7903 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7904 in the current radix, so "set radix 10" is always a no-op.
7906 height N: This integer value is the number of lines on a page. Default
7907 is 24, the current `stty rows'' setting, or the ``li#''
7908 setting from the termcap entry matching the environment
7911 width N: This integer value is the number of characters on a line.
7912 Default is 80, the current `stty cols'' setting, or the ``co#''
7913 setting from the termcap entry matching the environment
7916 Note: ``set screensize'' is obsolete. Use ``set height'' and
7917 ``set width'' instead.
7919 print address on/off: Print memory addresses in various command displays,
7920 such as stack traces and structure values. Gdb looks
7921 more ``symbolic'' if you turn this off; it looks more
7922 ``machine level'' with it on. Default is ON.
7924 print array on/off: Prettyprint arrays. New convenient format! Default
7927 print demangle on/off: Print C++ symbols in "source" form if on,
7930 print asm-demangle on/off: Same, for assembler level printouts
7933 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7936 * Support for Epoch Environment.
7938 The epoch environment is a version of Emacs v18 with windowing. One
7939 new command, ``inspect'', is identical to ``print'', except that if you
7940 are running in the epoch environment, the value is printed in its own
7944 * Support for Shared Libraries
7946 GDB can now debug programs and core files that use SunOS shared libraries.
7947 Symbols from a shared library cannot be referenced
7948 before the shared library has been linked with the program (this
7949 happens after you type ``run'' and before the function main() is entered).
7950 At any time after this linking (including when examining core files
7951 from dynamically linked programs), gdb reads the symbols from each
7952 shared library when you type the ``sharedlibrary'' command.
7953 It can be abbreviated ``share''.
7955 sharedlibrary REGEXP: Load shared object library symbols for files
7956 matching a unix regular expression. No argument
7957 indicates to load symbols for all shared libraries.
7959 info sharedlibrary: Status of loaded shared libraries.
7964 A watchpoint stops execution of a program whenever the value of an
7965 expression changes. Checking for this slows down execution
7966 tremendously whenever you are in the scope of the expression, but is
7967 quite useful for catching tough ``bit-spreader'' or pointer misuse
7968 problems. Some machines such as the 386 have hardware for doing this
7969 more quickly, and future versions of gdb will use this hardware.
7971 watch EXP: Set a watchpoint (breakpoint) for an expression.
7973 info watchpoints: Information about your watchpoints.
7975 delete N: Deletes watchpoint number N (same as breakpoints).
7976 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7977 enable N: Re-enables watchpoint number N (same as breakpoints).
7980 * C++ multiple inheritance
7982 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7985 * C++ exception handling
7987 Gdb now supports limited C++ exception handling. Besides the existing
7988 ability to breakpoint on an exception handler, gdb can breakpoint on
7989 the raising of an exception (before the stack is peeled back to the
7992 catch FOO: If there is a FOO exception handler in the dynamic scope,
7993 set a breakpoint to catch exceptions which may be raised there.
7994 Multiple exceptions (``catch foo bar baz'') may be caught.
7996 info catch: Lists all exceptions which may be caught in the
7997 current stack frame.
8000 * Minor command changes
8002 The command ``call func (arg, arg, ...)'' now acts like the print
8003 command, except it does not print or save a value if the function's result
8004 is void. This is similar to dbx usage.
8006 The ``up'' and ``down'' commands now always print the frame they end up
8007 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8008 frames without printing.
8010 * New directory command
8012 'dir' now adds directories to the FRONT of the source search path.
8013 The path starts off empty. Source files that contain debug information
8014 about the directory in which they were compiled can be found even
8015 with an empty path; Sun CC and GCC include this information. If GDB can't
8016 find your source file in the current directory, type "dir .".
8018 * Configuring GDB for compilation
8020 For normal use, type ``./configure host''. See README or gdb.texinfo
8023 GDB now handles cross debugging. If you are remotely debugging between
8024 two different machines, type ``./configure host -target=targ''.
8025 Host is the machine where GDB will run; targ is the machine
8026 where the program that you are debugging will run.