1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 10
6 * GDB now supports general memory tagging functionality if the underlying
7 architecture supports the proper primitives and hooks. Currently this is
8 enabled only for AArch64 MTE.
12 - Additional information when the inferior crashes with a SIGSEGV caused by
13 a memory tag violation.
15 - A new modifier 'm' for the "x" command, which displays allocation tags for a
16 particular memory range.
18 - Display of memory tag mismatches by "print", for addresses and
19 pointers, if memory tagging is supported by the architecture.
21 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
26 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
28 The MI -break-insert and -dprintf-insert commands now support a
29 new "--qualified" option that makes GDB interpret a specified
30 function name as a complete fully-qualified name. This is the
31 equivalent of the CLI's "break -qualified" and "dprintf
34 * GDB now supports core file debugging for x86_64 Cygwin programs.
36 * GDB will now look for the .gdbinit file in a config directory before
37 looking for ~/.gdbinit. The file is searched for in the following
38 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
39 $HOME/.gdbinit. On Apple hosts the search order is instead:
40 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
42 * GDB now supports fixed point types which are described in DWARF
43 as base types with a fixed-point encoding. Additionally, support
44 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
47 For Ada, this allows support for fixed point types without requiring
48 the use of the GNAT encoding (based on information added to the type's
49 name following a GNAT-specific format).
51 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
52 or ~/.gdbearlyinit if these files are present. These files are
53 processed earlier than any of the other initialization files and
54 can affect parts of GDB's startup that previously had already been
55 completed before the initialization files were read, for example
56 styling of the initial GDB greeting.
58 * GDB now has two new options "--early-init-command" and
59 "--early-init-eval-command" with corresponding short options "-eix"
60 and "-eiex" that allow options (that would normally appear in a
61 gdbearlyinit file) to be passed on the command line.
67 Control the display of debug output about GDB's event loop.
69 set print memory-tag-violations
70 show print memory-tag-violations
71 Control whether to display additional information about memory tag violations
72 when printing pointers and addresses. Architecture support for memory
73 tagging is required for this option to have an effect.
75 maintenance flush symbol-cache
76 maintenance flush register-cache
77 These new commands are equivalent to the already existing commands
78 'maintenance flush-symbol-cache' and 'flushregs' respectively.
80 maintenance flush dcache
81 A new command to flush the dcache.
83 maintenance info target-sections
84 Print GDB's internal target sections table.
86 memory-tag show-logical-tag POINTER
87 Print the logical tag for POINTER.
88 memory-tag with-logical-tag POINTER TAG
89 Print POINTER with logical tag TAG.
90 memory-tag show-allocation-tag ADDRESS
91 Print the allocation tag for ADDRESS.
92 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
93 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
94 memory-tag check POINTER
95 Validate that POINTER's logical tag matches the allocation tag.
99 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
100 [-force-condition] [if CONDITION]
101 This command would previously refuse setting a breakpoint if the
102 CONDITION expression is invalid at a location. It now accepts and
103 defines the breakpoint if there is at least one location at which
104 the CONDITION is valid. The locations for which the CONDITION is
105 invalid, are automatically disabled. If CONDITION is invalid at all
106 of the locations, setting the breakpoint is still rejected. However,
107 the '-force-condition' flag can be used in this case for forcing GDB to
108 define the breakpoint, making all the current locations automatically
109 disabled. This may be useful if the user knows the condition will
110 become meaningful at a future location, e.g. due to a shared library
113 condition [-force] N COND
114 The behavior of this command is changed the same way for the 'break'
115 command as explained above. The '-force' flag can be used to force
116 GDB into defining the condition even when COND is invalid for all the
117 current locations of breakpoint N.
120 maintenance flush-symbol-cache
121 These commands are deprecated in favor of the new commands
122 'maintenance flush register-cache' and 'maintenance flush
123 symbol-cache' respectively.
125 set style version foreground COLOR
126 set style version background COLOR
127 set style version intensity VALUE
128 Control the styling of GDB's version number text.
131 When the ID parameter is omitted, then this command prints information
132 about the current inferior. When the ID parameter is present, the
133 behavior of the command is unchanged and have the inferior ID become
134 the current inferior.
136 maintenance info sections
137 The ALLOBJ keyword has been replaced with an -all-objects command
138 line flag. It is now possible to filter which sections are printed
139 even when -all-objects is passed.
141 * Removed targets and native configurations
143 ARM Symbian arm*-*-symbianelf*
148 Request the remote to send allocation tags for a particular memory range.
150 Request the remote to store the specified allocation tags to the requested
153 *** Changes in GDB 10
155 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
156 and "org.gnu.gdb.arc.aux". The old names are still supported but
157 must be considered obsolete. They will be deprecated after some
160 * Help and apropos commands will now show the documentation of a
161 command only once, even if that command has one or more aliases.
162 These commands now show the command name, then all of its aliases,
163 and finally the description of the command.
165 * 'help aliases' now shows only the user defined aliases. GDB predefined
166 aliases are shown together with their aliased command.
168 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
169 debugging information as well as source code.
171 When built with debuginfod, GDB can automatically query debuginfod
172 servers for the separate debug files and source code of the executable
175 To build GDB with debuginfod, pass --with-debuginfod to configure (this
176 requires libdebuginfod, the debuginfod client library).
178 debuginfod is distributed with elfutils, starting with version 0.178.
180 You can get the latest version from https://sourceware.org/elfutils.
182 * Multi-target debugging support
184 GDB now supports debugging multiple target connections
185 simultaneously. For example, you can now have each inferior
186 connected to different remote servers running in different machines,
187 or have one inferior debugging a local native process, an inferior
188 debugging a core dump, etc.
190 This support is experimental and comes with some limitations -- you
191 can only resume multiple targets simultaneously if all targets
192 support non-stop mode, and all remote stubs or servers must support
193 the same set of remote protocol features exactly. See also "info
194 connections" and "add-inferior -no-connection" below, and "maint set
195 target-non-stop" in the user manual.
197 * New features in the GDB remote stub, GDBserver
199 ** GDBserver is now supported on ARC GNU/Linux.
201 ** GDBserver is now supported on RISC-V GNU/Linux.
203 ** GDBserver no longer supports these host triplets:
214 i[34567]86-*-mingw32ce*
216 * Debugging MS-Windows processes now sets $_exitsignal when the
217 inferior is terminated by a signal, instead of setting $_exitcode.
219 * Multithreaded symbol loading has now been enabled by default on systems
220 that support it (see entry for GDB 9, below), providing faster
221 performance for programs with many symbols.
223 * The $_siginfo convenience variable now also works on Windows targets,
224 and will display the EXCEPTION_RECORD of the last handled exception.
226 * TUI windows can now be arranged horizontally.
228 * The command history filename can now be set to the empty string
229 either using 'set history filename' or by setting 'GDBHISTFILE=' in
230 the environment. The effect of setting this filename to the empty
231 string is that GDB will not try to load any previous command
234 * On Windows targets, it is now possible to debug 32-bit programs with a
239 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
240 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
241 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
242 running process, this new option indicates whether to detect
243 a mismatch between the current executable file loaded by GDB and the
244 executable file used to start the process. If 'ask', the default,
245 display a warning and ask the user whether to load the process
246 executable file; if 'warn', just display a warning; if 'off', don't
247 attempt to detect a mismatch.
249 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
250 Define a new TUI layout, specifying its name and the windows that
253 maintenance print xml-tdesc [FILE]
254 Prints the current target description as an XML document. If the
255 optional FILE is provided (which is an XML target description) then
256 the target description is read from FILE into GDB, and then
259 maintenance print core-file-backed-mappings
260 Prints file-backed mappings loaded from a core file's note section.
261 Output is expected to be similar to that of "info proc mappings".
263 set debug fortran-array-slicing on|off
264 show debug fortran-array-slicing
265 Print debugging when taking slices of Fortran arrays.
267 set fortran repack-array-slices on|off
268 show fortran repack-array-slices
269 When taking slices from Fortran arrays and strings, if the slice is
270 non-contiguous within the original value then, when this option is
271 on, the new value will be repacked into a single contiguous value.
272 When this option is off, then the value returned will consist of a
273 descriptor that describes the slice within the memory of the
274 original parent value.
278 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
279 The alias command can now specify default args for an alias.
280 GDB automatically prepends the alias default args to the argument list
281 provided explicitly by the user.
282 For example, to have a backtrace with full details, you can define
284 'alias bt_ALL = backtrace -entry-values both -frame-arg all
285 -past-main -past-entry -full'.
286 Alias default arguments can also use a set of nested 'with' commands,
287 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
288 defines the alias pp10 that will pretty print a maximum of 10 elements
289 of the given expression (if the expression is an array).
293 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
298 ** gdb.register_window_type can be used to implement new TUI windows
301 ** Dynamic types can now be queried. gdb.Type has a new attribute,
302 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
303 field of a dynamic type may have None for its "bitpos" attribute
306 ** Commands written in Python can be in the "TUI" help class by
307 registering with the new constant gdb.COMMAND_TUI.
309 ** New method gdb.PendingFrame.architecture () to retrieve the
310 architecture of the pending frame.
312 ** New gdb.Architecture.registers method that returns a
313 gdb.RegisterDescriptorIterator object, an iterator that returns
314 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
315 way to query the registers available for an architecture.
317 ** New gdb.Architecture.register_groups method that returns a
318 gdb.RegisterGroupIterator object, an iterator that returns
319 gdb.RegisterGroup objects. The new RegisterGroup is a way to
320 discover the available register groups.
324 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
326 ** Procedures 'memory-port-read-buffer-size',
327 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
328 and 'set-memory-port-write-buffer-size!' are deprecated. When
329 using Guile 2.2 and later, users who need to control the size of
330 a memory port's internal buffer can use the 'setvbuf' procedure.
334 * 'thread-exited' event is now available in the annotations interface.
336 * New built-in convenience variables $_gdb_major and $_gdb_minor
337 provide the GDB version. They are handy for conditionally using
338 features available only in or since specific GDB versions, in
339 scripts that should work error-free with many different versions,
340 such as in system-wide init files.
342 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
343 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
344 of the GDB settings and the GDB maintenance settings. They are handy
345 for changing the logic of user defined commands depending on the
346 current GDB settings.
348 * GDB now supports Thread Local Storage (TLS) variables on several
349 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
350 architectures require kernel changes. TLS is not yet supported for
351 amd64 and i386 process core dumps.
353 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
354 addresses that required unmasking are shown in the backtrace with the
357 * Two new convenience functions $_cimag and $_creal that extract the
358 imaginary and real parts respectively from complex numbers.
360 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
361 provide the exitcode or exit status of the shell commands launched by
362 GDB commands such as "shell", "pipe" and "make".
364 * The command define-prefix can now define user defined prefix commands.
365 User defined commands can now be defined using these user defined prefix
368 * Command names can now use the . character.
370 * The RX port now supports XML target descriptions.
372 * GDB now shows the Ada task names at more places, e.g. in task switching
375 * GDB can now be compiled with Python 3 on Windows.
377 * New convenience variable $_ada_exception holds the address of the
378 Ada exception being thrown. This is set by Ada-related catchpoints.
380 * GDB can now place breakpoints on nested functions and subroutines in
381 Fortran code. The '::' operator can be used between parent and
382 child scopes when placing breakpoints, for example:
384 (gdb) break outer_function::inner_function
386 The 'outer_function::' prefix is only needed if 'inner_function' is
387 not visible in the current scope.
389 * In addition to the system-wide gdbinit file, if configured with
390 --with-system-gdbinit-dir, GDB will now also load files in that directory
391 as system gdbinit files, unless the -nx or -n flag is provided. Files
392 with extensions .gdb, .py and .scm are supported as long as GDB was
393 compiled with support for that language.
395 * GDB now supports multithreaded symbol loading for higher performance.
396 This feature is still in testing, so it is disabled by default. You
397 can turn it on using 'maint set worker-threads unlimited'.
401 ** The gdb.Value type has a new method 'format_string' which returns a
402 string representing the value. The formatting is controlled by the
403 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
404 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
405 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
407 ** gdb.Type has a new property 'objfile' which returns the objfile the
410 ** The frame information printed by the python frame filtering code
411 is now consistent with what the 'backtrace' command prints when
412 there are no filters, or when the 'backtrace' '-no-filters' option
415 ** The new function gdb.lookup_static_symbol can be used to look up
416 symbols with static linkage.
418 ** The new function gdb.lookup_static_symbols can be used to look up
419 all static symbols with static linkage.
421 ** gdb.Objfile has new methods 'lookup_global_symbol' and
422 'lookup_static_symbol' to lookup a symbol from this objfile only.
424 ** gdb.Block now supports the dictionary syntax for accessing symbols in
425 this block (e.g. block['local_variable']).
429 | [COMMAND] | SHELL_COMMAND
430 | -d DELIM COMMAND DELIM SHELL_COMMAND
431 pipe [COMMAND] | SHELL_COMMAND
432 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
433 Executes COMMAND and sends its output to SHELL_COMMAND.
434 With no COMMAND, repeat the last executed command
435 and send its output to SHELL_COMMAND.
437 define-prefix COMMAND
438 Define or mark a command as a user-defined prefix command.
440 with SETTING [VALUE] [-- COMMAND]
441 w SETTING [VALUE] [-- COMMAND]
442 Temporarily set SETTING, run COMMAND, and restore SETTING.
443 Usage: with SETTING -- COMMAND
444 With no COMMAND, repeats the last executed command.
445 SETTING is any GDB setting you can change with the "set"
446 subcommands. For example, 'with language c -- print someobj'
447 temporarily switches to the C language in order to print someobj.
448 Settings can be combined: 'w lang c -- w print elements unlimited --
449 usercmd' switches to the C language and runs usercmd with no limit
450 of array elements to print.
452 maint with SETTING [VALUE] [-- COMMAND]
453 Like "with", but works with "maintenance set" settings.
455 set may-call-functions [on|off]
456 show may-call-functions
457 This controls whether GDB will attempt to call functions in
458 the program, such as with expressions in the print command. It
459 defaults to on. Calling functions in the program being debugged
460 can have undesired side effects. It is now possible to forbid
461 such function calls. If function calls are forbidden, GDB will throw
462 an error when a command (such as print expression) calls a function
465 set print finish [on|off]
467 This controls whether the `finish' command will display the value
468 that is returned by the current function. When `off', the value is
469 still entered into the value history, but it is not printed. The
474 Allows deeply nested structures to be simplified when printing by
475 replacing deeply nested parts (beyond the max-depth) with ellipses.
476 The default max-depth is 20, but this can be set to unlimited to get
477 the old behavior back.
479 set print raw-values [on|off]
480 show print raw-values
481 By default, GDB applies the enabled pretty printers when printing a
482 value. This allows to ignore the enabled pretty printers for a series
483 of commands. The default is 'off'.
485 set logging debugredirect [on|off]
486 By default, GDB debug output will go to both the terminal and the logfile.
487 Set if you want debug output to go only to the log file.
489 set style title foreground COLOR
490 set style title background COLOR
491 set style title intensity VALUE
492 Control the styling of titles.
494 set style highlight foreground COLOR
495 set style highlight background COLOR
496 set style highlight intensity VALUE
497 Control the styling of highlightings.
499 maint set worker-threads
500 maint show worker-threads
501 Control the number of worker threads that can be used by GDB. The
502 default is 0. "unlimited" lets GDB choose a number that is
503 reasonable. Currently worker threads are only used when demangling
504 the names of linker symbols.
506 set style tui-border foreground COLOR
507 set style tui-border background COLOR
508 Control the styling of TUI borders.
510 set style tui-active-border foreground COLOR
511 set style tui-active-border background COLOR
512 Control the styling of the active TUI border.
514 maint set test-settings KIND
515 maint show test-settings KIND
516 A set of commands used by the testsuite for exercising the settings
519 maint set tui-resize-message [on|off]
520 maint show tui-resize-message
521 Control whether GDB prints a message each time the terminal is
522 resized when in TUI mode. This is primarily useful for testing the
525 set print frame-info [short-location|location|location-and-address
526 |source-and-location|source-line|auto]
527 show print frame-info
528 This controls what frame information is printed by the commands printing
529 a frame. This setting will e.g. influence the behaviour of 'backtrace',
530 'frame', 'stepi'. The python frame filtering also respect this setting.
531 The 'backtrace' '-frame-info' option can override this global setting.
533 set tui compact-source
534 show tui compact-source
536 Enable the "compact" display mode for the TUI source window. The
537 compact display uses only as much space as is needed for the line
538 numbers in the current file, and only a single space to separate the
539 line numbers from the source.
541 info modules [-q] [REGEXP]
542 Return a list of Fortran modules matching REGEXP, or all modules if
545 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
546 Return a list of functions within all modules, grouped by module.
547 The list of functions can be restricted with the optional regular
548 expressions. MODULE_REGEXP matches against the module name,
549 TYPE_REGEXP matches against the function type signature, and REGEXP
550 matches against the function name.
552 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
553 Return a list of variables within all modules, grouped by module.
554 The list of variables can be restricted with the optional regular
555 expressions. MODULE_REGEXP matches against the module name,
556 TYPE_REGEXP matches against the variable type, and REGEXP matches
557 against the variable name.
559 set debug remote-packet-max-chars
560 show debug remote-packet-max-chars
561 Controls the number of characters to output in a remote packet when using
563 The default is 512 bytes.
566 Lists the target connections currently in use.
571 The "help" command uses the title style to enhance the
572 readibility of its output by styling the classes and
576 Similarly to "help", the "apropos" command also uses the
577 title style for the command names. "apropos" accepts now
578 a flag "-v" (verbose) to show the full documentation
579 of matching commands and to use the highlight style to mark
580 the documentation parts matching REGEXP.
584 The GDB printf and eval commands can now print C-style and Ada-style
585 string convenience variables without calling functions in the program.
586 This allows to do formatted printing of strings without having
587 a running inferior, or when debugging a core dump.
589 info sources [-dirname | -basename] [--] [REGEXP]
590 This command has now optional arguments to only print the files
591 whose names match REGEXP. The arguments -dirname and -basename
592 allow to restrict matching respectively to the dirname and basename
596 The "show style" and its subcommands are now styling
597 a style name in their output using its own style, to help
598 the user visualize the different styles.
600 set print frame-arguments
601 The new value 'presence' indicates to only indicate the presence of
602 arguments using ..., instead of printing argument names and values.
604 set print raw-frame-arguments
605 show print raw-frame-arguments
607 These commands replace the similarly-named "set/show print raw
608 frame-arguments" commands (now with a dash instead of a space). The
609 old commands are now deprecated and may be removed in a future
612 add-inferior [-no-connection]
613 The add-inferior command now supports a "-no-connection" flag that
614 makes the new inferior start with no target connection associated.
615 By default, the new inferior inherits the target connection of the
616 current inferior. See also "info connections".
619 This command's output now includes a new "Connection" column
620 indicating which target connection an inferior is bound to. See
621 "info connections" above.
623 maint test-options require-delimiter
624 maint test-options unknown-is-error
625 maint test-options unknown-is-operand
626 maint show test-options-completion-result
627 Commands used by the testsuite to validate the command options
630 focus, winheight, +, -, >, <
631 These commands are now case-sensitive.
633 * New command options, command completion
635 GDB now has a standard infrastructure to support dash-style command
636 options ('-OPT'). One benefit is that commands that use it can
637 easily support completion of command line arguments. Try "CMD
638 -[TAB]" or "help CMD" to find options supported by a command. Over
639 time, we intend to migrate most commands to this infrastructure. A
640 number of commands got support for new command options in this
643 ** The "print" and "compile print" commands now support a number of
644 options that allow overriding relevant global print settings as
645 set by "set print" subcommands:
649 -array-indexes [on|off]
650 -elements NUMBER|unlimited
655 -repeats NUMBER|unlimited
656 -static-members [on|off]
661 Note that because the "print"/"compile print" commands accept
662 arbitrary expressions which may look like options (including
663 abbreviations), if you specify any command option, then you must
664 use a double dash ("--") to mark the end of argument processing.
666 ** The "backtrace" command now supports a number of options that
667 allow overriding relevant global print settings as set by "set
668 backtrace" and "set print" subcommands:
670 -entry-values no|only|preferred|if-needed|both|compact|default
671 -frame-arguments all|scalars|none
672 -raw-frame-arguments [on|off]
673 -frame-info auto|source-line|location|source-and-location
674 |location-and-address|short-location
678 In addition, the full/no-filters/hide qualifiers are now also
679 exposed as command options too:
685 ** The "frame apply", "tfaas" and "faas" commands similarly now
686 support the following options:
691 ** The new "info sources" options -dirname and -basename options
692 are using the standard '-OPT' infrastructure.
694 All options above can also be abbreviated. The argument of boolean
695 (on/off) options can be 0/1 too, and also the argument is assumed
696 "on" if omitted. This allows writing compact command invocations,
699 (gdb) p -ra -p -o 0 -- *myptr
701 The above is equivalent to:
703 (gdb) print -raw-values -pretty -object off -- *myptr
705 ** The "info types" command now supports the '-q' flag to disable
706 printing of some header information in a similar fashion to "info
707 variables" and "info functions".
709 ** The "info variables", "info functions", and "whereis" commands
710 now take a '-n' flag that excludes non-debug symbols (symbols
711 from the symbol table, not from the debug info such as DWARF)
714 * Completion improvements
716 ** GDB can now complete the options of the "thread apply all" and
717 "taas" commands, and their "-ascending" option can now be
720 ** GDB can now complete the options of the "info threads", "info
721 functions", "info variables", "info locals", and "info args"
724 ** GDB can now complete the options of the "compile file" and
725 "compile code" commands. The "compile file" command now
726 completes on filenames.
728 ** GDB can now complete the backtrace command's
729 "full/no-filters/hide" qualifiers.
731 * In settings, you can now abbreviate "unlimited".
733 E.g., "set print elements u" is now equivalent to "set print
739 This lists all the possible completions for the rest of the line, if it
740 were to be given as a command itself. This is intended for use by MI
741 frontends in cases when separate CLI and MI channels cannot be used.
743 -catch-throw, -catch-rethrow, and -catch-catch
744 These can be used to catch C++ exceptions in a similar fashion to
745 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
747 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
748 These commands are the MI equivalent of the CLI commands 'info
749 functions', 'info types', and 'info variables' respectively.
751 -symbol-info-modules, this is the MI equivalent of the CLI 'info
754 -symbol-info-module-functions and -symbol-info-module-variables.
755 These commands are the MI equivalent of the CLI commands 'info
756 module functions' and 'info module variables'.
760 ** The default version of the MI interpreter is now 3 (-i=mi3).
762 ** The output of information about multi-location breakpoints (which is
763 syntactically incorrect in MI 2) has changed in MI 3. This affects
764 the following commands and events:
768 - =breakpoint-created
769 - =breakpoint-modified
771 The -fix-multi-location-breakpoint-output command can be used to enable
772 this behavior with previous MI versions.
774 ** Backtraces and frames include a new optional field addr_flags which is
775 given after the addr field. On AArch64 this contains PAC if the address
776 has been masked in the frame. On all other targets the field is not
781 The testsuite now creates the files gdb.cmd (containing the arguments
782 used to launch GDB) and gdb.in (containing all the commands sent to
783 GDB) in the output directory for each test script. Multiple invocations
784 are appended with .1, .2, .3 etc.
786 * Building GDB and GDBserver now requires GNU make >= 3.82.
788 Using another implementation of the make program or an earlier version of
789 GNU make to build GDB or GDBserver is not supported.
791 * Building GDB now requires GNU readline >= 7.0.
793 GDB now bundles GNU readline 8.0, but if you choose to use
794 --with-system-readline, only readline >= 7.0 can be used.
796 * The TUI SingleKey keymap is now named "SingleKey". This can be used
797 from .inputrc to bind keys in this keymap. This feature is only
798 available when gdb is built against GNU readline 8.0 or later.
800 * Removed targets and native configurations
802 GDB no longer supports debugging the Cell Broadband Engine. This includes
803 both debugging standalone Cell/B.E. SPU applications and integrated debugging
804 of Cell/B.E. applications that use both the PPU and SPU architectures.
810 * Removed targets and native configurations
812 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
815 *** Changes in GDB 8.3
817 * GDB and GDBserver now support access to additional registers on
818 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
821 * GDB now has experimental support for the compilation and injection of
822 C++ source code into the inferior. This beta release does not include
823 support for several language features, such as templates, constructors,
826 This feature requires GCC 7.1 or higher built with libcp1.so
829 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
830 can be passed using the '[ADDRESS]:PORT' notation, or the regular
831 'ADDRESS:PORT' method.
833 * DWARF index cache: GDB can now automatically save indices of DWARF
834 symbols on disk to speed up further loading of the same binaries.
836 * Ada task switching is now supported on aarch64-elf targets when
837 debugging a program using the Ravenscar Profile. For more information,
838 see the "Tasking Support when using the Ravenscar Profile" section
839 in the GDB user manual.
841 * GDB in batch mode now exits with status 1 if the last command to be
844 * The RISC-V target now supports target descriptions.
846 * System call catchpoints now support system call aliases on FreeBSD.
847 When the ABI of a system call changes in FreeBSD, this is
848 implemented by leaving a compatibility system call using the old ABI
849 at the existing number and allocating a new system call number for
850 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
851 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
852 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
853 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
854 so that a system call catchpoint for the 'kevent' system call will
855 catch invocations of both the 'kevent' and 'freebsd11_kevent'
856 binaries. This ensures that 'kevent' system calls are caught for
857 binaries using either the old or new ABIs.
859 * Terminal styling is now available for the CLI and the TUI. GNU
860 Source Highlight can additionally be used to provide styling of
861 source code snippets. See the "set style" commands, below, for more
864 * Removed support for old demangling styles arm, edg, gnu, hp and
869 set debug compile-cplus-types
870 show debug compile-cplus-types
871 Control the display of debug output about type conversion in the
872 C++ compile feature. Commands have no effect while compiling
877 Control whether debug output about files/functions skipping is
880 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
881 Apply a command to some frames.
882 FLAG arguments allow to control what output to produce and how to handle
883 errors raised when applying COMMAND to a frame.
886 Apply a command to all threads (ignoring errors and empty output).
887 Shortcut for 'thread apply all -s COMMAND'.
890 Apply a command to all frames (ignoring errors and empty output).
891 Shortcut for 'frame apply all -s COMMAND'.
894 Apply a command to all frames of all threads (ignoring errors and empty
896 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
898 maint set dwarf unwinders (on|off)
899 maint show dwarf unwinders
900 Control whether DWARF unwinders can be used.
903 Display a list of open files for a process.
907 Changes to the "frame", "select-frame", and "info frame" CLI commands.
908 These commands all now take a frame specification which
909 is either a frame level, or one of the keywords 'level', 'address',
910 'function', or 'view' followed by a parameter. Selecting a frame by
911 address, or viewing a frame outside the current backtrace now
912 requires the use of a keyword. Selecting a frame by level is
913 unchanged. The MI comment "-stack-select-frame" is unchanged.
915 target remote FILENAME
916 target extended-remote FILENAME
917 If FILENAME is a Unix domain socket, GDB will attempt to connect
918 to this socket instead of opening FILENAME as a character device.
920 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
921 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
922 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
923 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
924 These commands can now print only the searched entities
925 matching the provided regexp(s), giving a condition
926 on the entity names or entity types. The flag -q disables
927 printing headers or informations messages.
933 These commands now determine the syntax for the shown entities
934 according to the language chosen by `set language'. In particular,
935 `set language auto' means to automatically choose the language of
938 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
939 The 'thread apply' command accepts new FLAG arguments.
940 FLAG arguments allow to control what output to produce and how to handle
941 errors raised when applying COMMAND to a thread.
943 set tui tab-width NCHARS
944 show tui tab-width NCHARS
945 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
947 set style enabled [on|off]
949 Enable or disable terminal styling. Styling is enabled by default
950 on most hosts, but disabled by default when in batch mode.
952 set style sources [on|off]
954 Enable or disable source code styling. Source code styling is
955 enabled by default, but only takes effect if styling in general is
956 enabled, and if GDB was linked with GNU Source Highlight.
958 set style filename foreground COLOR
959 set style filename background COLOR
960 set style filename intensity VALUE
961 Control the styling of file names.
963 set style function foreground COLOR
964 set style function background COLOR
965 set style function intensity VALUE
966 Control the styling of function names.
968 set style variable foreground COLOR
969 set style variable background COLOR
970 set style variable intensity VALUE
971 Control the styling of variable names.
973 set style address foreground COLOR
974 set style address background COLOR
975 set style address intensity VALUE
976 Control the styling of addresses.
980 ** The '-data-disassemble' MI command now accepts an '-a' option to
981 disassemble the whole function surrounding the given program
982 counter value or function name. Support for this feature can be
983 verified by using the "-list-features" command, which should
984 contain "data-disassemble-a-option".
986 ** Command responses and notifications that include a frame now include
987 the frame's architecture in a new "arch" attribute.
989 * New native configurations
991 GNU/Linux/RISC-V riscv*-*-linux*
992 FreeBSD/riscv riscv*-*-freebsd*
996 GNU/Linux/RISC-V riscv*-*-linux*
998 CSKY GNU/LINUX csky*-*-linux
999 FreeBSD/riscv riscv*-*-freebsd*
1001 GNU/Linux/OpenRISC or1k*-*-linux*
1005 GDB no longer supports native debugging on versions of MS-Windows
1010 ** GDB no longer supports Python versions less than 2.6.
1012 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1013 space associated to that inferior.
1015 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1016 of objfiles associated to that program space.
1018 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1019 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1022 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1023 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1024 correct and did not work properly.
1026 ** The gdb.Value type has a new constructor, which is used to construct a
1027 gdb.Value from a Python buffer object and a gdb.Type.
1033 Enable or disable the undefined behavior sanitizer. This is
1034 disabled by default, but passing --enable-ubsan=yes or
1035 --enable-ubsan=auto to configure will enable it. Enabling this can
1036 cause a performance penalty. The undefined behavior sanitizer was
1037 first introduced in GCC 4.9.
1039 *** Changes in GDB 8.2
1041 * The 'set disassembler-options' command now supports specifying options
1042 for the MIPS target.
1044 * The 'symbol-file' command now accepts an '-o' option to add a relative
1045 offset to all sections.
1047 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1048 a relative offset to all sections, but it allows to override the load
1049 address of individual sections using '-s'.
1051 * The 'add-symbol-file' command no longer requires the second argument
1052 (address of the text section).
1054 * The endianness used with the 'set endian auto' mode in the absence of
1055 an executable selected for debugging is now the last endianness chosen
1056 either by one of the 'set endian big' and 'set endian little' commands
1057 or by inferring from the last executable used, rather than the startup
1060 * The pager now allows a "c" response, meaning to disable the pager
1061 for the rest of the current command.
1063 * The commands 'info variables/functions/types' now show the source line
1064 numbers of symbol definitions when available.
1066 * 'info proc' now works on running processes on FreeBSD systems and core
1067 files created on FreeBSD systems.
1069 * C expressions can now use _Alignof, and C++ expressions can now use
1072 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1073 the vector length while the process is running.
1079 Control display of debugging info regarding the FreeBSD native target.
1081 set|show varsize-limit
1082 This new setting allows the user to control the maximum size of Ada
1083 objects being printed when those objects have a variable type,
1084 instead of that maximum size being hardcoded to 65536 bytes.
1086 set|show record btrace cpu
1087 Controls the processor to be used for enabling errata workarounds for
1088 branch trace decode.
1090 maint check libthread-db
1091 Run integrity checks on the current inferior's thread debugging
1094 maint set check-libthread-db (on|off)
1095 maint show check-libthread-db
1096 Control whether to run integrity checks on inferior specific thread
1097 debugging libraries as they are loaded. The default is not to
1098 perform such checks.
1102 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1104 ** The commands attached to a breakpoint can be set by assigning to
1105 the breakpoint's "commands" field.
1107 ** gdb.execute can now execute multi-line gdb commands.
1109 ** The new functions gdb.convenience_variable and
1110 gdb.set_convenience_variable can be used to get and set the value
1111 of convenience variables.
1113 ** A gdb.Parameter will no longer print the "set" help text on an
1114 ordinary "set"; instead by default a "set" will be silent unless
1115 the get_set_string method returns a non-empty string.
1119 RiscV ELF riscv*-*-elf
1121 * Removed targets and native configurations
1123 m88k running OpenBSD m88*-*-openbsd*
1124 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1125 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1126 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1128 * Aarch64/Linux hardware watchpoints improvements
1130 Hardware watchpoints on unaligned addresses are now properly
1131 supported when running Linux kernel 4.10 or higher: read and access
1132 watchpoints are no longer spuriously missed, and all watchpoints
1133 lengths between 1 and 8 bytes are supported. On older kernels,
1134 watchpoints set on unaligned addresses are no longer missed, with
1135 the tradeoff that there is a possibility of false hits being
1140 --enable-codesign=CERT
1141 This can be used to invoke "codesign -s CERT" after building gdb.
1142 This option is useful on macOS, where code signing is required for
1143 gdb to work properly.
1145 --disable-gdbcli has been removed
1146 This is now silently accepted, but does nothing.
1148 *** Changes in GDB 8.1
1150 * GDB now supports dynamically creating arbitrary register groups specified
1151 in XML target descriptions. This allows for finer grain grouping of
1152 registers on systems with a large amount of registers.
1154 * The 'ptype' command now accepts a '/o' flag, which prints the
1155 offsets and sizes of fields in a struct, like the pahole(1) tool.
1157 * New "--readnever" command line option instructs GDB to not read each
1158 symbol file's symbolic debug information. This makes startup faster
1159 but at the expense of not being able to perform symbolic debugging.
1160 This option is intended for use cases where symbolic debugging will
1161 not be used, e.g., when you only need to dump the debuggee's core.
1163 * GDB now uses the GNU MPFR library, if available, to emulate target
1164 floating-point arithmetic during expression evaluation when the target
1165 uses different floating-point formats than the host. At least version
1166 3.1 of GNU MPFR is required.
1168 * GDB now supports access to the guarded-storage-control registers and the
1169 software-based guarded-storage broadcast control registers on IBM z14.
1171 * On Unix systems, GDB now supports transmitting environment variables
1172 that are to be set or unset to GDBserver. These variables will
1173 affect the environment to be passed to the remote inferior.
1175 To inform GDB of environment variables that are to be transmitted to
1176 GDBserver, use the "set environment" command. Only user set
1177 environment variables are sent to GDBserver.
1179 To inform GDB of environment variables that are to be unset before
1180 the remote inferior is started by the GDBserver, use the "unset
1181 environment" command.
1183 * Completion improvements
1185 ** GDB can now complete function parameters in linespecs and
1186 explicit locations without quoting. When setting breakpoints,
1187 quoting around functions names to help with TAB-completion is
1188 generally no longer necessary. For example, this now completes
1191 (gdb) b function(in[TAB]
1192 (gdb) b function(int)
1194 Related, GDB is no longer confused with completing functions in
1195 C++ anonymous namespaces:
1198 (gdb) b (anonymous namespace)::[TAB][TAB]
1199 (anonymous namespace)::a_function()
1200 (anonymous namespace)::b_function()
1202 ** GDB now has much improved linespec and explicit locations TAB
1203 completion support, that better understands what you're
1204 completing and offers better suggestions. For example, GDB no
1205 longer offers data symbols as possible completions when you're
1206 setting a breakpoint.
1208 ** GDB now TAB-completes label symbol names.
1210 ** The "complete" command now mimics TAB completion accurately.
1212 * New command line options (gcore)
1215 Dump all memory mappings.
1217 * Breakpoints on C++ functions are now set on all scopes by default
1219 By default, breakpoints on functions/methods are now interpreted as
1220 specifying all functions with the given name ignoring missing
1221 leading scopes (namespaces and classes).
1223 For example, assuming a C++ program with symbols named:
1228 both commands "break func()" and "break B::func()" set a breakpoint
1231 You can use the new flag "-qualified" to override this. This makes
1232 GDB interpret the specified function name as a complete
1233 fully-qualified name instead. For example, using the same C++
1234 program, the "break -q B::func" command sets a breakpoint on
1235 "B::func", only. A parameter has been added to the Python
1236 gdb.Breakpoint constructor to achieve the same result when creating
1237 a breakpoint from Python.
1239 * Breakpoints on functions marked with C++ ABI tags
1241 GDB can now set breakpoints on functions marked with C++ ABI tags
1242 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1243 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1245 Functions with a C++11 abi tag are demangled/displayed like this:
1247 function[abi:cxx11](int)
1250 You can now set a breakpoint on such functions simply as if they had
1253 (gdb) b function(int)
1255 Or if you need to disambiguate between tags, like:
1257 (gdb) b function[abi:other_tag](int)
1259 Tab completion was adjusted accordingly as well.
1263 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1264 gdb.new_thread are emitted. See the manual for further
1265 description of these.
1267 ** A new function, "gdb.rbreak" has been added to the Python API.
1268 This function allows the setting of a large number of breakpoints
1269 via a regex pattern in Python. See the manual for further details.
1271 ** Python breakpoints can now accept explicit locations. See the
1272 manual for a further description of this feature.
1275 * New features in the GDB remote stub, GDBserver
1277 ** GDBserver is now able to start inferior processes with a
1278 specified initial working directory.
1280 The user can set the desired working directory to be used from
1281 GDB using the new "set cwd" command.
1283 ** New "--selftest" command line option runs some GDBserver self
1284 tests. These self tests are disabled in releases.
1286 ** On Unix systems, GDBserver now does globbing expansion and variable
1287 substitution in inferior command line arguments.
1289 This is done by starting inferiors using a shell, like GDB does.
1290 See "set startup-with-shell" in the user manual for how to disable
1291 this from GDB when using "target extended-remote". When using
1292 "target remote", you can disable the startup with shell by using the
1293 new "--no-startup-with-shell" GDBserver command line option.
1295 ** On Unix systems, GDBserver now supports receiving environment
1296 variables that are to be set or unset from GDB. These variables
1297 will affect the environment to be passed to the inferior.
1299 * When catching an Ada exception raised with a message, GDB now prints
1300 the message in the catchpoint hit notification. In GDB/MI mode, that
1301 information is provided as an extra field named "exception-message"
1302 in the *stopped notification.
1304 * Trait objects can now be inspected When debugging Rust code. This
1305 requires compiler support which will appear in Rust 1.24.
1307 * New remote packets
1309 QEnvironmentHexEncoded
1310 Inform GDBserver of an environment variable that is to be passed to
1311 the inferior when starting it.
1314 Inform GDBserver of an environment variable that is to be unset
1315 before starting the remote inferior.
1318 Inform GDBserver that the environment should be reset (i.e.,
1319 user-set environment variables should be unset).
1322 Indicates whether the inferior must be started with a shell or not.
1325 Tell GDBserver that the inferior to be started should use a specific
1328 * The "maintenance print c-tdesc" command now takes an optional
1329 argument which is the file name of XML target description.
1331 * The "maintenance selftest" command now takes an optional argument to
1332 filter the tests to be run.
1334 * The "enable", and "disable" commands now accept a range of
1335 breakpoint locations, e.g. "enable 1.3-5".
1340 Set and show the current working directory for the inferior.
1342 set|show compile-gcc
1343 Set and show compilation command used for compiling and injecting code
1344 with the 'compile' commands.
1346 set debug separate-debug-file
1347 show debug separate-debug-file
1348 Control the display of debug output about separate debug file search.
1350 set dump-excluded-mappings
1351 show dump-excluded-mappings
1352 Control whether mappings marked with the VM_DONTDUMP flag should be
1353 dumped when generating a core file.
1355 maint info selftests
1356 List the registered selftests.
1359 Start the debugged program stopping at the first instruction.
1362 Control display of debugging messages related to OpenRISC targets.
1364 set|show print type nested-type-limit
1365 Set and show the limit of nesting level for nested types that the
1366 type printer will show.
1368 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1371 * Safer/improved support for debugging with no debug info
1373 GDB no longer assumes functions with no debug information return
1376 This means that GDB now refuses to call such functions unless you
1377 tell it the function's type, by either casting the call to the
1378 declared return type, or by casting the function to a function
1379 pointer of the right type, and calling that:
1381 (gdb) p getenv ("PATH")
1382 'getenv' has unknown return type; cast the call to its declared return type
1383 (gdb) p (char *) getenv ("PATH")
1384 $1 = 0x7fffffffe "/usr/local/bin:/"...
1385 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1386 $2 = 0x7fffffffe "/usr/local/bin:/"...
1388 Similarly, GDB no longer assumes that global variables with no debug
1389 info have type 'int', and refuses to print the variable's value
1390 unless you tell it the variable's type:
1393 'var' has unknown type; cast it to its declared type
1397 * New native configurations
1399 FreeBSD/aarch64 aarch64*-*-freebsd*
1400 FreeBSD/arm arm*-*-freebsd*
1404 FreeBSD/aarch64 aarch64*-*-freebsd*
1405 FreeBSD/arm arm*-*-freebsd*
1406 OpenRISC ELF or1k*-*-elf
1408 * Removed targets and native configurations
1410 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1412 *** Changes in GDB 8.0
1414 * GDB now supports access to the PKU register on GNU/Linux. The register is
1415 added by the Memory Protection Keys for Userspace feature which will be
1416 available in future Intel CPUs.
1418 * GDB now supports C++11 rvalue references.
1422 ** New functions to start, stop and access a running btrace recording.
1423 ** Rvalue references are now supported in gdb.Type.
1425 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1428 * Building GDB and GDBserver now requires a C++11 compiler.
1430 For example, GCC 4.8 or later.
1432 It is no longer possible to build GDB or GDBserver with a C
1433 compiler. The --disable-build-with-cxx configure option has been
1436 * Building GDB and GDBserver now requires GNU make >= 3.81.
1438 It is no longer supported to build GDB or GDBserver with another
1439 implementation of the make program or an earlier version of GNU make.
1441 * Native debugging on MS-Windows supports command-line redirection
1443 Command-line arguments used for starting programs on MS-Windows can
1444 now include redirection symbols supported by native Windows shells,
1445 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1446 as "run", "start", and "set args", as well as the corresponding MI
1449 * Support for thread names on MS-Windows.
1451 GDB now catches and handles the special exception that programs
1452 running on MS-Windows use to assign names to threads in the
1455 * Support for Java programs compiled with gcj has been removed.
1457 * User commands now accept an unlimited number of arguments.
1458 Previously, only up to 10 was accepted.
1460 * The "eval" command now expands user-defined command arguments.
1462 This makes it easier to process a variable number of arguments:
1467 eval "print $arg%d", $i
1472 * Target descriptions can now describe registers for sparc32 and sparc64.
1474 * GDB now supports DWARF version 5 (debug information format).
1475 Its .debug_names index is not yet supported.
1477 * New native configurations
1479 FreeBSD/mips mips*-*-freebsd
1483 Synopsys ARC arc*-*-elf32
1484 FreeBSD/mips mips*-*-freebsd
1486 * Removed targets and native configurations
1488 Alpha running FreeBSD alpha*-*-freebsd*
1489 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1494 Erases all the flash memory regions reported by the target.
1496 maint print arc arc-instruction address
1497 Print internal disassembler information about instruction at a given address.
1501 set disassembler-options
1502 show disassembler-options
1503 Controls the passing of target specific information to the disassembler.
1504 If it is necessary to specify more than one disassembler option then
1505 multiple options can be placed together into a comma separated list.
1506 The default value is the empty string. Currently, the only supported
1507 targets are ARM, PowerPC and S/390.
1512 Erases all the flash memory regions reported by the target. This is
1513 equivalent to the CLI command flash-erase.
1515 -file-list-shared-libraries
1516 List the shared libraries in the program. This is
1517 equivalent to the CLI command "info shared".
1520 Catchpoints stopping the program when Ada exceptions are
1521 handled. This is equivalent to the CLI command "catch handlers".
1523 *** Changes in GDB 7.12
1525 * GDB and GDBserver now build with a C++ compiler by default.
1527 The --enable-build-with-cxx configure option is now enabled by
1528 default. One must now explicitly configure with
1529 --disable-build-with-cxx in order to build with a C compiler. This
1530 option will be removed in a future release.
1532 * GDBserver now supports recording btrace without maintaining an active
1535 * GDB now supports a negative repeat count in the 'x' command to examine
1536 memory backward from the given address. For example:
1539 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1540 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1541 (gdb) x/-5i 0x0000000000400580
1542 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1543 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1544 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1545 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1546 0x40057b <main(int, char**)+25>:
1547 callq 0x400536 <Func1(int, char const*)>
1549 * Fortran: Support structures with fields of dynamic types and
1550 arrays of dynamic types.
1552 * The symbol dumping maintenance commands have new syntax.
1553 maint print symbols [-pc address] [--] [filename]
1554 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1555 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1556 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1557 maint print msymbols [-objfile objfile] [--] [filename]
1559 * GDB now supports multibit bitfields and enums in target register
1562 * New Python-based convenience function $_as_string(val), which returns
1563 the textual representation of a value. This function is especially
1564 useful to obtain the text label of an enum value.
1566 * Intel MPX bound violation handling.
1568 Segmentation faults caused by a Intel MPX boundary violation
1569 now display the kind of violation (upper or lower), the memory
1570 address accessed and the memory bounds, along with the usual
1571 signal received and code location.
1575 Program received signal SIGSEGV, Segmentation fault
1576 Upper bound violation while accessing address 0x7fffffffc3b3
1577 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1578 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1580 * Rust language support.
1581 GDB now supports debugging programs written in the Rust programming
1582 language. See https://www.rust-lang.org/ for more information about
1585 * Support for running interpreters on specified input/output devices
1587 GDB now supports a new mechanism that allows frontends to provide
1588 fully featured GDB console views, as a better alternative to
1589 building such views on top of the "-interpreter-exec console"
1590 command. See the new "new-ui" command below. With that command,
1591 frontends can now start GDB in the traditional command-line mode
1592 running in an embedded terminal emulator widget, and create a
1593 separate MI interpreter running on a specified i/o device. In this
1594 way, GDB handles line editing, history, tab completion, etc. in the
1595 console all by itself, and the GUI uses the separate MI interpreter
1596 for its own control and synchronization, invisible to the command
1599 * The "catch syscall" command catches groups of related syscalls.
1601 The "catch syscall" command now supports catching a group of related
1602 syscalls using the 'group:' or 'g:' prefix.
1607 skip -gfile file-glob-pattern
1608 skip -function function
1609 skip -rfunction regular-expression
1610 A generalized form of the skip command, with new support for
1611 glob-style file names and regular expressions for function names.
1612 Additionally, a file spec and a function spec may now be combined.
1614 maint info line-table REGEXP
1615 Display the contents of GDB's internal line table data structure.
1618 Run any GDB unit tests that were compiled in.
1621 Start a new user interface instance running INTERP as interpreter,
1622 using the TTY file for input/output.
1626 ** gdb.Breakpoint objects have a new attribute "pending", which
1627 indicates whether the breakpoint is pending.
1628 ** Three new breakpoint-related events have been added:
1629 gdb.breakpoint_created, gdb.breakpoint_modified, and
1630 gdb.breakpoint_deleted.
1632 signal-event EVENTID
1633 Signal ("set") the given MS-Windows event object. This is used in
1634 conjunction with the Windows JIT debugging (AeDebug) support, where
1635 the OS suspends a crashing process until a debugger can attach to
1636 it. Resuming the crashing process, in order to debug it, is done by
1637 signalling an event.
1639 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1640 was added in GDBserver, including JIT compiling fast tracepoint's
1641 conditional expression bytecode into native code.
1643 * Support for various remote target protocols and ROM monitors has
1646 target m32rsdi Remote M32R debugging over SDI
1647 target mips MIPS remote debugging protocol
1648 target pmon PMON ROM monitor
1649 target ddb NEC's DDB variant of PMON for Vr4300
1650 target rockhopper NEC RockHopper variant of PMON
1651 target lsi LSI variant of PMO
1653 * Support for tracepoints and fast tracepoints on powerpc-linux,
1654 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1655 including JIT compiling fast tracepoint's conditional expression
1656 bytecode into native code.
1658 * MI async record =record-started now includes the method and format used for
1659 recording. For example:
1661 =record-started,thread-group="i1",method="btrace",format="bts"
1663 * MI async record =thread-selected now includes the frame field. For example:
1665 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1669 Andes NDS32 nds32*-*-elf
1671 *** Changes in GDB 7.11
1673 * GDB now supports debugging kernel-based threads on FreeBSD.
1675 * Per-inferior thread numbers
1677 Thread numbers are now per inferior instead of global. If you're
1678 debugging multiple inferiors, GDB displays thread IDs using a
1679 qualified INF_NUM.THR_NUM form. For example:
1683 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1684 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1685 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1686 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1688 As consequence, thread numbers as visible in the $_thread
1689 convenience variable and in Python's InferiorThread.num attribute
1690 are no longer unique between inferiors.
1692 GDB now maintains a second thread ID per thread, referred to as the
1693 global thread ID, which is the new equivalent of thread numbers in
1694 previous releases. See also $_gthread below.
1696 For backwards compatibility, MI's thread IDs always refer to global
1699 * Commands that accept thread IDs now accept the qualified
1700 INF_NUM.THR_NUM form as well. For example:
1703 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1706 * In commands that accept a list of thread IDs, you can now refer to
1707 all threads of an inferior using a star wildcard. GDB accepts
1708 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1709 refer to all threads of the current inferior. For example, "info
1712 * You can use "info threads -gid" to display the global thread ID of
1715 * The new convenience variable $_gthread holds the global number of
1718 * The new convenience variable $_inferior holds the number of the
1721 * GDB now displays the ID and name of the thread that hit a breakpoint
1722 or received a signal, if your program is multi-threaded. For
1725 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1726 Thread 1 "main" received signal SIGINT, Interrupt.
1728 * Record btrace now supports non-stop mode.
1730 * Support for tracepoints on aarch64-linux was added in GDBserver.
1732 * The 'record instruction-history' command now indicates speculative execution
1733 when using the Intel Processor Trace recording format.
1735 * GDB now allows users to specify explicit locations, bypassing
1736 the linespec parser. This feature is also available to GDB/MI
1739 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1740 GDB now is able to debug both AArch64 applications and ARM applications
1743 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1744 including JIT compiling fast tracepoint's conditional expression bytecode
1747 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1749 * "info threads", "info inferiors", "info display", "info checkpoints"
1750 and "maint info program-spaces" now list the corresponding items in
1751 ascending ID order, for consistency with all other "info" commands.
1753 * In Ada, the overloads selection menu has been enhanced to display the
1754 parameter types and the return types for the matching overloaded subprograms.
1758 maint set target-non-stop (on|off|auto)
1759 maint show target-non-stop
1760 Control whether GDB targets always operate in non-stop mode even if
1761 "set non-stop" is "off". The default is "auto", meaning non-stop
1762 mode is enabled if supported by the target.
1764 maint set bfd-sharing
1765 maint show bfd-sharing
1766 Control the reuse of bfd objects.
1769 show debug bfd-cache
1770 Control display of debugging info regarding bfd caching.
1774 Control display of debugging info regarding FreeBSD threads.
1776 set remote multiprocess-extensions-packet
1777 show remote multiprocess-extensions-packet
1778 Set/show the use of the remote protocol multiprocess extensions.
1780 set remote thread-events
1781 show remote thread-events
1782 Set/show the use of thread create/exit events.
1784 set ada print-signatures on|off
1785 show ada print-signatures"
1786 Control whether parameter types and return types are displayed in overloads
1787 selection menus. It is activated (@code{on}) by default.
1791 Controls the maximum size of memory, in bytes, that GDB will
1792 allocate for value contents. Prevents incorrect programs from
1793 causing GDB to allocate overly large buffers. Default is 64k.
1795 * The "disassemble" command accepts a new modifier: /s.
1796 It prints mixed source+disassembly like /m with two differences:
1797 - disassembled instructions are now printed in program order, and
1798 - and source for all relevant files is now printed.
1799 The "/m" option is now considered deprecated: its "source-centric"
1800 output hasn't proved useful in practice.
1802 * The "record instruction-history" command accepts a new modifier: /s.
1803 It behaves exactly like /m and prints mixed source+disassembly.
1805 * The "set scheduler-locking" command supports a new mode "replay".
1806 It behaves like "off" in record mode and like "on" in replay mode.
1808 * Support for various ROM monitors has been removed:
1810 target dbug dBUG ROM monitor for Motorola ColdFire
1811 target picobug Motorola picobug monitor
1812 target dink32 DINK32 ROM monitor for PowerPC
1813 target m32r Renesas M32R/D ROM monitor
1814 target mon2000 mon2000 ROM monitor
1815 target ppcbug PPCBUG ROM monitor for PowerPC
1817 * Support for reading/writing memory and extracting values on architectures
1818 whose memory is addressable in units of any integral multiple of 8 bits.
1821 Allows to break when an Ada exception is handled.
1823 * New remote packets
1826 Indicates that an exec system call was executed.
1828 exec-events feature in qSupported
1829 The qSupported packet allows GDB to request support for exec
1830 events using the new 'gdbfeature' exec-event, and the qSupported
1831 response can contain the corresponding 'stubfeature'. Set and
1832 show commands can be used to display whether these features are enabled.
1835 Equivalent to interrupting with the ^C character, but works in
1838 thread created stop reason (T05 create:...)
1839 Indicates that the thread was just created and is stopped at entry.
1841 thread exit stop reply (w exitcode;tid)
1842 Indicates that the thread has terminated.
1845 Enables/disables thread create and exit event reporting. For
1846 example, this is used in non-stop mode when GDB stops a set of
1847 threads and synchronously waits for the their corresponding stop
1848 replies. Without exit events, if one of the threads exits, GDB
1849 would hang forever not knowing that it should no longer expect a
1850 stop for that same thread.
1853 Indicates that there are no resumed threads left in the target (all
1854 threads are stopped). The remote stub reports support for this stop
1855 reply to GDB's qSupported query.
1858 Enables/disables catching syscalls from the inferior process.
1859 The remote stub reports support for this packet to GDB's qSupported query.
1861 syscall_entry stop reason
1862 Indicates that a syscall was just called.
1864 syscall_return stop reason
1865 Indicates that a syscall just returned.
1867 * Extended-remote exec events
1869 ** GDB now has support for exec events on extended-remote Linux targets.
1870 For such targets with Linux kernels 2.5.46 and later, this enables
1871 follow-exec-mode and exec catchpoints.
1873 set remote exec-event-feature-packet
1874 show remote exec-event-feature-packet
1875 Set/show the use of the remote exec event feature.
1877 * Thread names in remote protocol
1879 The reply to qXfer:threads:read may now include a name attribute for each
1882 * Target remote mode fork and exec events
1884 ** GDB now has support for fork and exec events on target remote mode
1885 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1886 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1887 fork and exec catchpoints.
1889 * Remote syscall events
1891 ** GDB now has support for catch syscall on remote Linux targets,
1892 currently enabled on x86/x86_64 architectures.
1894 set remote catch-syscall-packet
1895 show remote catch-syscall-packet
1896 Set/show the use of the remote catch syscall feature.
1900 ** The -var-set-format command now accepts the zero-hexadecimal
1901 format. It outputs data in hexadecimal format with zero-padding on the
1906 ** gdb.InferiorThread objects have a new attribute "global_num",
1907 which refers to the thread's global thread ID. The existing
1908 "num" attribute now refers to the thread's per-inferior number.
1909 See "Per-inferior thread numbers" above.
1910 ** gdb.InferiorThread objects have a new attribute "inferior", which
1911 is the Inferior object the thread belongs to.
1913 *** Changes in GDB 7.10
1915 * Support for process record-replay and reverse debugging on aarch64*-linux*
1916 targets has been added. GDB now supports recording of A64 instruction set
1917 including advance SIMD instructions.
1919 * Support for Sun's version of the "stabs" debug file format has been removed.
1921 * GDB now honors the content of the file /proc/PID/coredump_filter
1922 (PID is the process ID) on GNU/Linux systems. This file can be used
1923 to specify the types of memory mappings that will be included in a
1924 corefile. For more information, please refer to the manual page of
1925 "core(5)". GDB also has a new command: "set use-coredump-filter
1926 on|off". It allows to set whether GDB will read the content of the
1927 /proc/PID/coredump_filter file when generating a corefile.
1929 * The "info os" command on GNU/Linux can now display information on
1931 "info os cpus" Listing of all cpus/cores on the system
1933 * GDB has two new commands: "set serial parity odd|even|none" and
1934 "show serial parity". These allows to set or show parity for the
1937 * The "info source" command now displays the producer string if it was
1938 present in the debug info. This typically includes the compiler version
1939 and may include things like its command line arguments.
1941 * The "info dll", an alias of the "info sharedlibrary" command,
1942 is now available on all platforms.
1944 * Directory names supplied to the "set sysroot" commands may be
1945 prefixed with "target:" to tell GDB to access shared libraries from
1946 the target system, be it local or remote. This replaces the prefix
1947 "remote:". The default sysroot has been changed from "" to
1948 "target:". "remote:" is automatically converted to "target:" for
1949 backward compatibility.
1951 * The system root specified by "set sysroot" will be prepended to the
1952 filename of the main executable (if reported to GDB as absolute by
1953 the operating system) when starting processes remotely, and when
1954 attaching to already-running local or remote processes.
1956 * GDB now supports automatic location and retrieval of executable
1957 files from remote targets. Remote debugging can now be initiated
1958 using only a "target remote" or "target extended-remote" command
1959 (no "set sysroot" or "file" commands are required). See "New remote
1962 * The "dump" command now supports verilog hex format.
1964 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1966 * On GNU/Linux, GDB and gdbserver are now able to access executable
1967 and shared library files without a "set sysroot" command when
1968 attaching to processes running in different mount namespaces from
1969 the debugger. This makes it possible to attach to processes in
1970 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1971 See "New remote packets" below.
1973 * The "tui reg" command now provides completion for all of the
1974 available register groups, including target specific groups.
1976 * The HISTSIZE environment variable is no longer read when determining
1977 the size of GDB's command history. GDB now instead reads the dedicated
1978 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1979 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1984 ** Memory ports can now be unbuffered.
1988 ** gdb.Objfile objects have a new attribute "username",
1989 which is the name of the objfile as specified by the user,
1990 without, for example, resolving symlinks.
1991 ** You can now write frame unwinders in Python.
1992 ** gdb.Type objects have a new method "optimized_out",
1993 returning optimized out gdb.Value instance of this type.
1994 ** gdb.Value objects have new methods "reference_value" and
1995 "const_value" which return a reference to the value and a
1996 "const" version of the value respectively.
2000 maint print symbol-cache
2001 Print the contents of the symbol cache.
2003 maint print symbol-cache-statistics
2004 Print statistics of symbol cache usage.
2006 maint flush-symbol-cache
2007 Flush the contents of the symbol cache.
2011 Start branch trace recording using Branch Trace Store (BTS) format.
2014 Evaluate expression by using the compiler and print result.
2018 Explicit commands for enabling and disabling tui mode.
2021 set mpx bound on i386 and amd64
2022 Support for bound table investigation on Intel MPX enabled applications.
2026 Start branch trace recording using Intel Processor Trace format.
2029 Print information about branch tracing internals.
2031 maint btrace packet-history
2032 Print the raw branch tracing data.
2034 maint btrace clear-packet-history
2035 Discard the stored raw branch tracing data.
2038 Discard all branch tracing data. It will be fetched and processed
2039 anew by the next "record" command.
2044 Renamed from "set debug dwarf2-die".
2045 show debug dwarf-die
2046 Renamed from "show debug dwarf2-die".
2048 set debug dwarf-read
2049 Renamed from "set debug dwarf2-read".
2050 show debug dwarf-read
2051 Renamed from "show debug dwarf2-read".
2053 maint set dwarf always-disassemble
2054 Renamed from "maint set dwarf2 always-disassemble".
2055 maint show dwarf always-disassemble
2056 Renamed from "maint show dwarf2 always-disassemble".
2058 maint set dwarf max-cache-age
2059 Renamed from "maint set dwarf2 max-cache-age".
2060 maint show dwarf max-cache-age
2061 Renamed from "maint show dwarf2 max-cache-age".
2063 set debug dwarf-line
2064 show debug dwarf-line
2065 Control display of debugging info regarding DWARF line processing.
2068 show max-completions
2069 Set the maximum number of candidates to be considered during
2070 completion. The default value is 200. This limit allows GDB
2071 to avoid generating large completion lists, the computation of
2072 which can cause the debugger to become temporarily unresponsive.
2074 set history remove-duplicates
2075 show history remove-duplicates
2076 Control the removal of duplicate history entries.
2078 maint set symbol-cache-size
2079 maint show symbol-cache-size
2080 Control the size of the symbol cache.
2082 set|show record btrace bts buffer-size
2083 Set and show the size of the ring buffer used for branch tracing in
2085 The obtained size may differ from the requested size. Use "info
2086 record" to see the obtained buffer size.
2088 set debug linux-namespaces
2089 show debug linux-namespaces
2090 Control display of debugging info regarding Linux namespaces.
2092 set|show record btrace pt buffer-size
2093 Set and show the size of the ring buffer used for branch tracing in
2094 Intel Processor Trace format.
2095 The obtained size may differ from the requested size. Use "info
2096 record" to see the obtained buffer size.
2098 maint set|show btrace pt skip-pad
2099 Set and show whether PAD packets are skipped when computing the
2102 * The command 'thread apply all' can now support new option '-ascending'
2103 to call its specified command for all threads in ascending order.
2105 * Python/Guile scripting
2107 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2108 special section named `.debug_gdb_scripts'.
2110 * New remote packets
2112 qXfer:btrace-conf:read
2113 Return the branch trace configuration for the current thread.
2115 Qbtrace-conf:bts:size
2116 Set the requested ring buffer size for branch tracing in BTS format.
2119 Enable Intel Processor Trace-based branch tracing for the current
2120 process. The remote stub reports support for this packet to GDB's
2123 Qbtrace-conf:pt:size
2124 Set the requested ring buffer size for branch tracing in Intel Processor
2128 Indicates a memory breakpoint instruction was executed, irrespective
2129 of whether it was GDB that planted the breakpoint or the breakpoint
2130 is hardcoded in the program. This is required for correct non-stop
2134 Indicates the target stopped for a hardware breakpoint. This is
2135 required for correct non-stop mode operation.
2138 Return information about files on the remote system.
2140 qXfer:exec-file:read
2141 Return the full absolute name of the file that was executed to
2142 create a process running on the remote system.
2145 Select the filesystem on which vFile: operations with filename
2146 arguments will operate. This is required for GDB to be able to
2147 access files on remote targets where the remote stub does not
2148 share a common filesystem with the inferior(s).
2151 Indicates that a fork system call was executed.
2154 Indicates that a vfork system call was executed.
2156 vforkdone stop reason
2157 Indicates that a vfork child of the specified process has executed
2158 an exec or exit, allowing the vfork parent to resume execution.
2160 fork-events and vfork-events features in qSupported
2161 The qSupported packet allows GDB to request support for fork and
2162 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2163 and the qSupported response can contain the corresponding
2164 'stubfeatures'. Set and show commands can be used to display
2165 whether these features are enabled.
2167 * Extended-remote fork events
2169 ** GDB now has support for fork events on extended-remote Linux
2170 targets. For targets with Linux kernels 2.5.60 and later, this
2171 enables follow-fork-mode and detach-on-fork for both fork and
2172 vfork, as well as fork and vfork catchpoints.
2174 * The info record command now shows the recording format and the
2175 branch tracing configuration for the current thread when using
2176 the btrace record target.
2177 For the BTS format, it shows the ring buffer size.
2179 * GDB now has support for DTrace USDT (Userland Static Defined
2180 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2182 * GDB now supports access to vector registers on S/390 GNU/Linux
2185 * Removed command line options
2187 -xdb HP-UX XDB compatibility mode.
2189 * Removed targets and native configurations
2191 HP/PA running HP-UX hppa*-*-hpux*
2192 Itanium running HP-UX ia64-*-hpux*
2194 * New configure options
2197 This configure option allows the user to build GDB with support for
2198 Intel Processor Trace (default: auto). This requires libipt.
2200 --with-libipt-prefix=PATH
2201 Specify the path to the version of libipt that GDB should use.
2202 $PATH/include should contain the intel-pt.h header and
2203 $PATH/lib should contain the libipt.so library.
2205 *** Changes in GDB 7.9.1
2209 ** Xmethods can now specify a result type.
2211 *** Changes in GDB 7.9
2213 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2217 ** You can now access frame registers from Python scripts.
2218 ** New attribute 'producer' for gdb.Symtab objects.
2219 ** gdb.Objfile objects have a new attribute "progspace",
2220 which is the gdb.Progspace object of the containing program space.
2221 ** gdb.Objfile objects have a new attribute "owner".
2222 ** gdb.Objfile objects have a new attribute "build_id",
2223 which is the build ID generated when the file was built.
2224 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2225 ** A new event "gdb.clear_objfiles" has been added, triggered when
2226 selecting a new file to debug.
2227 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2228 ** New function gdb.lookup_objfile.
2230 New events which are triggered when GDB modifies the state of the
2233 ** gdb.events.inferior_call_pre: Function call is about to be made.
2234 ** gdb.events.inferior_call_post: Function call has just been made.
2235 ** gdb.events.memory_changed: A memory location has been altered.
2236 ** gdb.events.register_changed: A register has been altered.
2238 * New Python-based convenience functions:
2240 ** $_caller_is(name [, number_of_frames])
2241 ** $_caller_matches(regexp [, number_of_frames])
2242 ** $_any_caller_is(name [, number_of_frames])
2243 ** $_any_caller_matches(regexp [, number_of_frames])
2245 * GDB now supports the compilation and injection of source code into
2246 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2247 to compile the source code to object code, and if successful, inject
2248 and execute that code within the current context of the inferior.
2249 Currently the C language is supported. The commands used to
2250 interface with this new feature are:
2252 compile code [-raw|-r] [--] [source code]
2253 compile file [-raw|-r] filename
2257 demangle [-l language] [--] name
2258 Demangle "name" in the specified language, or the current language
2259 if elided. This command is renamed from the "maint demangle" command.
2260 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2261 as "maint demangler-warning".
2263 queue-signal signal-name-or-number
2264 Queue a signal to be delivered to the thread when it is resumed.
2266 add-auto-load-scripts-directory directory
2267 Add entries to the list of directories from which to load auto-loaded
2270 maint print user-registers
2271 List all currently available "user" registers.
2273 compile code [-r|-raw] [--] [source code]
2274 Compile, inject, and execute in the inferior the executable object
2275 code produced by compiling the provided source code.
2277 compile file [-r|-raw] filename
2278 Compile and inject into the inferior the executable object code
2279 produced by compiling the source code stored in the filename
2282 * On resume, GDB now always passes the signal the program had stopped
2283 for to the thread the signal was sent to, even if the user changed
2284 threads before resuming. Previously GDB would often (but not
2285 always) deliver the signal to the thread that happens to be current
2288 * Conversely, the "signal" command now consistently delivers the
2289 requested signal to the current thread. GDB now asks for
2290 confirmation if the program had stopped for a signal and the user
2291 switched threads meanwhile.
2293 * "breakpoint always-inserted" modes "off" and "auto" merged.
2295 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2296 won't remove breakpoints from the target until all threads stop,
2297 even in non-stop mode. The "auto" mode has been removed, and "off"
2298 is now the default mode.
2302 set debug symbol-lookup
2303 show debug symbol-lookup
2304 Control display of debugging info regarding symbol lookup.
2308 ** The -list-thread-groups command outputs an exit-code field for
2309 inferiors that have exited.
2313 MIPS SDE mips*-sde*-elf*
2317 Support for these obsolete configurations has been removed.
2319 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2320 SGI Irix-5.x mips-*-irix5*
2321 SGI Irix-6.x mips-*-irix6*
2322 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2323 VAX running Ultrix vax-*-ultrix*
2325 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2326 and "assf"), have been removed. Use the "sharedlibrary" command, or
2327 its alias "share", instead.
2329 *** Changes in GDB 7.8
2331 * New command line options
2334 This is an alias for the --data-directory option.
2336 * GDB supports printing and modifying of variable length automatic arrays
2337 as specified in ISO C99.
2339 * The ARM simulator now supports instruction level tracing
2340 with or without disassembly.
2344 GDB now has support for scripting using Guile. Whether this is
2345 available is determined at configure time.
2346 Guile version 2.0 or greater is required.
2347 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2349 * New commands (for set/show, see "New options" below)
2353 Invoke CODE by passing it to the Guile interpreter.
2357 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2359 info auto-load guile-scripts [regexp]
2360 Print the list of automatically loaded Guile scripts.
2362 * The source command is now capable of sourcing Guile scripts.
2363 This feature is dependent on the debugger being built with Guile support.
2367 set print symbol-loading (off|brief|full)
2368 show print symbol-loading
2369 Control whether to print informational messages when loading symbol
2370 information for a file. The default is "full", but when debugging
2371 programs with large numbers of shared libraries the amount of output
2372 becomes less useful.
2374 set guile print-stack (none|message|full)
2375 show guile print-stack
2376 Show a stack trace when an error is encountered in a Guile script.
2378 set auto-load guile-scripts (on|off)
2379 show auto-load guile-scripts
2380 Control auto-loading of Guile script files.
2382 maint ada set ignore-descriptive-types (on|off)
2383 maint ada show ignore-descriptive-types
2384 Control whether the debugger should ignore descriptive types in Ada
2385 programs. The default is not to ignore the descriptive types. See
2386 the user manual for more details on descriptive types and the intended
2387 usage of this option.
2389 set auto-connect-native-target
2391 Control whether GDB is allowed to automatically connect to the
2392 native target for the run, attach, etc. commands when not connected
2393 to any target yet. See also "target native" below.
2395 set record btrace replay-memory-access (read-only|read-write)
2396 show record btrace replay-memory-access
2397 Control what memory accesses are allowed during replay.
2399 maint set target-async (on|off)
2400 maint show target-async
2401 This controls whether GDB targets operate in synchronous or
2402 asynchronous mode. Normally the default is asynchronous, if it is
2403 available; but this can be changed to more easily debug problems
2404 occurring only in synchronous mode.
2406 set mi-async (on|off)
2408 Control whether MI asynchronous mode is preferred. This supersedes
2409 "set target-async" of previous GDB versions.
2411 * "set target-async" is deprecated as a CLI option and is now an alias
2412 for "set mi-async" (only puts MI into async mode).
2414 * Background execution commands (e.g., "c&", "s&", etc.) are now
2415 possible ``out of the box'' if the target supports them. Previously
2416 the user would need to explicitly enable the possibility with the
2417 "set target-async on" command.
2419 * New features in the GDB remote stub, GDBserver
2421 ** New option --debug-format=option1[,option2,...] allows one to add
2422 additional text to each output. At present only timestamps
2423 are supported: --debug-format=timestamps.
2424 Timestamps can also be turned on with the
2425 "monitor set debug-format timestamps" command from GDB.
2427 * The 'record instruction-history' command now starts counting instructions
2428 at one. This also affects the instruction ranges reported by the
2429 'record function-call-history' command when given the /i modifier.
2431 * The command 'record function-call-history' supports a new modifier '/c' to
2432 indent the function names based on their call stack depth.
2433 The fields for the '/i' and '/l' modifier have been reordered.
2434 The source line range is now prefixed with 'at'.
2435 The instruction range is now prefixed with 'inst'.
2436 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2437 "record instruction-history" and "list" commands.
2439 * The ranges given as arguments to the 'record function-call-history' and
2440 'record instruction-history' commands are now inclusive.
2442 * The btrace record target now supports the 'record goto' command.
2443 For locations inside the execution trace, the back trace is computed
2444 based on the information stored in the execution trace.
2446 * The btrace record target supports limited reverse execution and replay.
2447 The target does not record data and therefore does not allow reading
2448 memory or registers.
2450 * The "catch syscall" command now works on s390*-linux* targets.
2452 * The "compare-sections" command is no longer specific to target
2453 remote. It now works with all targets.
2455 * All native targets are now consistently called "native".
2456 Consequently, the "target child", "target GNU", "target djgpp",
2457 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2458 commands have been replaced with "target native". The QNX/NTO port
2459 leaves the "procfs" target in place and adds a "native" target for
2460 consistency with other ports. The impact on users should be minimal
2461 as these commands previously either throwed an error, or were
2462 no-ops. The target's name is visible in the output of the following
2463 commands: "help target", "info target", "info files", "maint print
2466 * The "target native" command now connects to the native target. This
2467 can be used to launch native programs even when "set
2468 auto-connect-native-target" is set to off.
2470 * GDB now supports access to Intel MPX registers on GNU/Linux.
2472 * Support for Intel AVX-512 registers on GNU/Linux.
2473 Support displaying and modifying Intel AVX-512 registers
2474 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2476 * New remote packets
2478 qXfer:btrace:read's annex
2479 The qXfer:btrace:read packet supports a new annex 'delta' to read
2480 branch trace incrementally.
2484 ** Valid Python operations on gdb.Value objects representing
2485 structs/classes invoke the corresponding overloaded operators if
2487 ** New `Xmethods' feature in the Python API. Xmethods are
2488 additional methods or replacements for existing methods of a C++
2489 class. This feature is useful for those cases where a method
2490 defined in C++ source code could be inlined or optimized out by
2491 the compiler, making it unavailable to GDB.
2494 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2496 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2497 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2498 its alias "share", instead.
2500 * The commands "set remotebaud" and "show remotebaud" are no longer
2501 supported. Use "set serial baud" and "show serial baud" (respectively)
2506 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2507 target-async". The latter is left as a deprecated alias of the
2508 former for backward compatibility. If the target supports it,
2509 CLI background execution commands are now always possible by
2510 default, independently of whether the frontend stated a
2511 preference for asynchronous execution with "-gdb-set mi-async".
2512 Previously "-gdb-set target-async off" affected both MI execution
2513 commands and CLI execution commands.
2515 *** Changes in GDB 7.7
2517 * Improved support for process record-replay and reverse debugging on
2518 arm*-linux* targets. Support for thumb32 and syscall instruction
2519 recording has been added.
2521 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2523 * GDB now supports Fission DWP file format version 2.
2524 http://gcc.gnu.org/wiki/DebugFission
2526 * New convenience function "$_isvoid", to check whether an expression
2527 is void. A void expression is an expression where the type of the
2528 result is "void". For example, some convenience variables may be
2529 "void" when evaluated (e.g., "$_exitcode" before the execution of
2530 the program being debugged; or an undefined convenience variable).
2531 Another example, when calling a function whose return type is
2534 * The "maintenance print objfiles" command now takes an optional regexp.
2536 * The "catch syscall" command now works on arm*-linux* targets.
2538 * GDB now consistently shows "<not saved>" when printing values of
2539 registers the debug info indicates have not been saved in the frame
2540 and there's nowhere to retrieve them from
2541 (callee-saved/call-clobbered registers):
2546 (gdb) info registers rax
2549 Before, the former would print "<optimized out>", and the latter
2550 "*value not available*".
2552 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2557 ** Frame filters and frame decorators have been added.
2558 ** Temporary breakpoints are now supported.
2559 ** Line tables representation has been added.
2560 ** New attribute 'parent_type' for gdb.Field objects.
2561 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2562 ** New attribute 'name' for gdb.Type objects.
2566 Nios II ELF nios2*-*-elf
2567 Nios II GNU/Linux nios2*-*-linux
2568 Texas Instruments MSP430 msp430*-*-elf
2570 * Removed native configurations
2572 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2573 been removed. ELF variants of these configurations are kept supported.
2575 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2576 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2577 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2578 i[34567]86-*-openbsd3.[0-3]
2579 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2580 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2581 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2585 Like "catch throw", but catches a re-thrown exception.
2586 maint check-psymtabs
2587 Renamed from old "maint check-symtabs".
2589 Perform consistency checks on symtabs.
2590 maint expand-symtabs
2591 Expand symtabs matching an optional regexp.
2594 Display the details of GDB configure-time options.
2596 maint set|show per-command
2597 maint set|show per-command space
2598 maint set|show per-command time
2599 maint set|show per-command symtab
2600 Enable display of per-command gdb resource usage.
2602 remove-symbol-file FILENAME
2603 remove-symbol-file -a ADDRESS
2604 Remove a symbol file added via add-symbol-file. The file to remove
2605 can be identified by its filename or by an address that lies within
2606 the boundaries of this symbol file in memory.
2609 info exceptions REGEXP
2610 Display the list of Ada exceptions defined in the program being
2611 debugged. If provided, only the exceptions whose names match REGEXP
2616 set debug symfile off|on
2618 Control display of debugging info regarding reading symbol files and
2619 symbol tables within those files
2621 set print raw frame-arguments
2622 show print raw frame-arguments
2623 Set/show whether to print frame arguments in raw mode,
2624 disregarding any defined pretty-printers.
2626 set remote trace-status-packet
2627 show remote trace-status-packet
2628 Set/show the use of remote protocol qTStatus packet.
2632 Control display of debugging messages related to Nios II targets.
2636 Control whether target-assisted range stepping is enabled.
2638 set startup-with-shell
2639 show startup-with-shell
2640 Specifies whether Unix child processes are started via a shell or
2645 Use the target memory cache for accesses to the code segment. This
2646 improves performance of remote debugging (particularly disassembly).
2648 * You can now use a literal value 'unlimited' for options that
2649 interpret 0 or -1 as meaning "unlimited". E.g., "set
2650 trace-buffer-size unlimited" is now an alias for "set
2651 trace-buffer-size -1" and "set height unlimited" is now an alias for
2654 * The "set debug symtab-create" debugging option of GDB has been changed to
2655 accept a verbosity level. 0 means "off", 1 provides basic debugging
2656 output, and values of 2 or greater provides more verbose output.
2658 * New command-line options
2660 Display the details of GDB configure-time options.
2662 * The command 'tsave' can now support new option '-ctf' to save trace
2663 buffer in Common Trace Format.
2665 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2668 * GDB now implements the C++ 'typeid' operator.
2670 * The new convenience variable $_exception holds the exception being
2671 thrown or caught at an exception-related catchpoint.
2673 * The exception-related catchpoints, like "catch throw", now accept a
2674 regular expression which can be used to filter exceptions by type.
2676 * The new convenience variable $_exitsignal is automatically set to
2677 the terminating signal number when the program being debugged dies
2678 due to an uncaught signal.
2682 ** All MI commands now accept an optional "--language" option.
2683 Support for this feature can be verified by using the "-list-features"
2684 command, which should contain "language-option".
2686 ** The new command -info-gdb-mi-command allows the user to determine
2687 whether a GDB/MI command is supported or not.
2689 ** The "^error" result record returned when trying to execute an undefined
2690 GDB/MI command now provides a variable named "code" whose content is the
2691 "undefined-command" error code. Support for this feature can be verified
2692 by using the "-list-features" command, which should contain
2693 "undefined-command-error-code".
2695 ** The -trace-save MI command can optionally save trace buffer in Common
2698 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2700 ** The command -data-list-register-values now accepts an optional
2701 "--skip-unavailable" option. When used, only the available registers
2704 ** The new command -trace-frame-collected dumps collected variables,
2705 computed expressions, tvars, memory and registers in a traceframe.
2707 ** The commands -stack-list-locals, -stack-list-arguments and
2708 -stack-list-variables now accept an option "--skip-unavailable".
2709 When used, only the available locals or arguments are displayed.
2711 ** The -exec-run command now accepts an optional "--start" option.
2712 When used, the command follows the same semantics as the "start"
2713 command, stopping the program's execution at the start of its
2714 main subprogram. Support for this feature can be verified using
2715 the "-list-features" command, which should contain
2716 "exec-run-start-option".
2718 ** The new commands -catch-assert and -catch-exceptions insert
2719 catchpoints stopping the program when Ada exceptions are raised.
2721 ** The new command -info-ada-exceptions provides the equivalent of
2722 the new "info exceptions" command.
2724 * New system-wide configuration scripts
2725 A GDB installation now provides scripts suitable for use as system-wide
2726 configuration scripts for the following systems:
2730 * GDB now supports target-assigned range stepping with remote targets.
2731 This improves the performance of stepping source lines by reducing
2732 the number of control packets from/to GDB. See "New remote packets"
2735 * GDB now understands the element 'tvar' in the XML traceframe info.
2736 It has the id of the collected trace state variables.
2738 * On S/390 targets that provide the transactional-execution feature,
2739 the program interruption transaction diagnostic block (TDB) is now
2740 represented as a number of additional "registers" in GDB.
2742 * New remote packets
2746 The vCont packet supports a new 'r' action, that tells the remote
2747 stub to step through an address range itself, without GDB
2748 involvemement at each single-step.
2750 qXfer:libraries-svr4:read's annex
2751 The previously unused annex of the qXfer:libraries-svr4:read packet
2752 is now used to support passing an argument list. The remote stub
2753 reports support for this argument list to GDB's qSupported query.
2754 The defined arguments are "start" and "prev", used to reduce work
2755 necessary for library list updating, resulting in significant
2758 * New features in the GDB remote stub, GDBserver
2760 ** GDBserver now supports target-assisted range stepping. Currently
2761 enabled on x86/x86_64 GNU/Linux targets.
2763 ** GDBserver now adds element 'tvar' in the XML in the reply to
2764 'qXfer:traceframe-info:read'. It has the id of the collected
2765 trace state variables.
2767 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2770 * New 'z' formatter for printing and examining memory, this displays the
2771 value as hexadecimal zero padded on the left to the size of the type.
2773 * GDB can now use Windows x64 unwinding data.
2775 * The "set remotebaud" command has been replaced by "set serial baud".
2776 Similarly, "show remotebaud" has been replaced by "show serial baud".
2777 The "set remotebaud" and "show remotebaud" commands are still available
2778 to provide backward compatibility with older versions of GDB.
2780 *** Changes in GDB 7.6
2782 * Target record has been renamed to record-full.
2783 Record/replay is now enabled with the "record full" command.
2784 This also affects settings that are associated with full record/replay
2785 that have been moved from "set/show record" to "set/show record full":
2787 set|show record full insn-number-max
2788 set|show record full stop-at-limit
2789 set|show record full memory-query
2791 * A new record target "record-btrace" has been added. The new target
2792 uses hardware support to record the control-flow of a process. It
2793 does not support replaying the execution, but it implements the
2794 below new commands for investigating the recorded execution log.
2795 This new recording method can be enabled using:
2799 The "record-btrace" target is only available on Intel Atom processors
2800 and requires a Linux kernel 2.6.32 or later.
2802 * Two new commands have been added for record/replay to give information
2803 about the recorded execution without having to replay the execution.
2804 The commands are only supported by "record btrace".
2806 record instruction-history prints the execution history at
2807 instruction granularity
2809 record function-call-history prints the execution history at
2810 function granularity
2812 * New native configurations
2814 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2815 FreeBSD/powerpc powerpc*-*-freebsd
2816 x86_64/Cygwin x86_64-*-cygwin*
2817 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2821 ARM AArch64 aarch64*-*-elf
2822 ARM AArch64 GNU/Linux aarch64*-*-linux
2823 Lynx 178 PowerPC powerpc-*-lynx*178
2824 x86_64/Cygwin x86_64-*-cygwin*
2825 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2827 * If the configured location of system.gdbinit file (as given by the
2828 --with-system-gdbinit option at configure time) is in the
2829 data-directory (as specified by --with-gdb-datadir at configure
2830 time) or in one of its subdirectories, then GDB will look for the
2831 system-wide init file in the directory specified by the
2832 --data-directory command-line option.
2834 * New command line options:
2836 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2837 other initialization files, unlike -nx which disables all of them.
2839 * Removed command line options
2841 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2844 * The 'ptype' and 'whatis' commands now accept an argument to control
2847 * 'info proc' now works on some core files.
2851 ** Vectors can be created with gdb.Type.vector.
2853 ** Python's atexit.register now works in GDB.
2855 ** Types can be pretty-printed via a Python API.
2857 ** Python 3 is now supported (in addition to Python 2.4 or later)
2859 ** New class gdb.Architecture exposes GDB's internal representation
2860 of architecture in the Python API.
2862 ** New method Frame.architecture returns the gdb.Architecture object
2863 corresponding to the frame's architecture.
2865 * New Python-based convenience functions:
2867 ** $_memeq(buf1, buf2, length)
2868 ** $_streq(str1, str2)
2870 ** $_regex(str, regex)
2872 * The 'cd' command now defaults to using '~' (the home directory) if not
2875 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2876 default for GCC since November 2000.
2878 * The command 'forward-search' can now be abbreviated as 'fo'.
2880 * The command 'info tracepoints' can now display 'installed on target'
2881 or 'not installed on target' for each non-pending location of tracepoint.
2883 * New configure options
2885 --enable-libmcheck/--disable-libmcheck
2886 By default, development versions are built with -lmcheck on hosts
2887 that support it, in order to help track memory corruption issues.
2888 Release versions, on the other hand, are built without -lmcheck
2889 by default. The --enable-libmcheck/--disable-libmcheck configure
2890 options allow the user to override that default.
2891 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2892 This configure option allows the user to build GDB with
2893 libbabeltrace using which GDB can read Common Trace Format data.
2895 * New commands (for set/show, see "New options" below)
2898 Catch signals. This is similar to "handle", but allows commands and
2899 conditions to be attached.
2902 List the BFDs known to GDB.
2904 python-interactive [command]
2906 Start a Python interactive prompt, or evaluate the optional command
2907 and print the result of expressions.
2910 "py" is a new alias for "python".
2912 enable type-printer [name]...
2913 disable type-printer [name]...
2914 Enable or disable type printers.
2918 ** For the Renesas Super-H architecture, the "regs" command has been removed
2919 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2924 set print type methods (on|off)
2925 show print type methods
2926 Control whether method declarations are displayed by "ptype".
2927 The default is to show them.
2929 set print type typedefs (on|off)
2930 show print type typedefs
2931 Control whether typedef definitions are displayed by "ptype".
2932 The default is to show them.
2934 set filename-display basename|relative|absolute
2935 show filename-display
2936 Control the way in which filenames is displayed.
2937 The default is "relative", which preserves previous behavior.
2939 set trace-buffer-size
2940 show trace-buffer-size
2941 Request target to change the size of trace buffer.
2943 set remote trace-buffer-size-packet auto|on|off
2944 show remote trace-buffer-size-packet
2945 Control the use of the remote protocol `QTBuffer:size' packet.
2949 Control display of debugging messages related to ARM AArch64.
2952 set debug coff-pe-read
2953 show debug coff-pe-read
2954 Control display of debugging messages related to reading of COFF/PE
2959 Control display of debugging messages related to Mach-O symbols
2962 set debug notification
2963 show debug notification
2964 Control display of debugging info for async remote notification.
2968 ** Command parameter changes are now notified using new async record
2969 "=cmd-param-changed".
2970 ** Trace frame changes caused by command "tfind" are now notified using
2971 new async record "=traceframe-changed".
2972 ** The creation, deletion and modification of trace state variables
2973 are now notified using new async records "=tsv-created",
2974 "=tsv-deleted" and "=tsv-modified".
2975 ** The start and stop of process record are now notified using new
2976 async record "=record-started" and "=record-stopped".
2977 ** Memory changes are now notified using new async record
2979 ** The data-disassemble command response will include a "fullname" field
2980 containing the absolute file name when source has been requested.
2981 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2982 command, to allow pattern filling of memory areas.
2983 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2984 library load/unload events.
2985 ** The response to breakpoint commands and breakpoint async records
2986 includes an "installed" field containing a boolean state about each
2987 non-pending tracepoint location is whether installed on target or not.
2988 ** Output of the "-trace-status" command includes a "trace-file" field
2989 containing the name of the trace file being examined. This field is
2990 optional, and only present when examining a trace file.
2991 ** The "fullname" field is now always present along with the "file" field,
2992 even if the file cannot be found by GDB.
2994 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2995 You must have the LZMA library available when configuring GDB for this
2996 feature to be enabled. For more information, see:
2997 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2999 * New remote packets
3002 Set the size of trace buffer. The remote stub reports support for this
3003 packet to gdb's qSupported query.
3006 Enable Branch Trace Store (BTS)-based branch tracing for the current
3007 thread. The remote stub reports support for this packet to gdb's
3011 Disable branch tracing for the current thread. The remote stub reports
3012 support for this packet to gdb's qSupported query.
3015 Read the traced branches for the current thread. The remote stub
3016 reports support for this packet to gdb's qSupported query.
3018 *** Changes in GDB 7.5
3020 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3021 for more x32 ABI info.
3023 * GDB now supports access to MIPS DSP registers on Linux targets.
3025 * GDB now supports debugging microMIPS binaries.
3027 * The "info os" command on GNU/Linux can now display information on
3028 several new classes of objects managed by the operating system:
3029 "info os procgroups" lists process groups
3030 "info os files" lists file descriptors
3031 "info os sockets" lists internet-domain sockets
3032 "info os shm" lists shared-memory regions
3033 "info os semaphores" lists semaphores
3034 "info os msg" lists message queues
3035 "info os modules" lists loaded kernel modules
3037 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3038 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3039 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3040 options and inspect the probe arguments using the new $_probe_arg family
3041 of convenience variables. You can obtain more information about SystemTap
3042 in <http://sourceware.org/systemtap/>.
3044 * GDB now supports reversible debugging on ARM, it allows you to
3045 debug basic ARM and THUMB instructions, and provides
3046 record/replay support.
3048 * The option "symbol-reloading" has been deleted as it is no longer used.
3052 ** GDB commands implemented in Python can now be put in command class
3055 ** The "maint set python print-stack on|off" is now deleted.
3057 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3058 apply "flag enum"-style pretty-printing to any enum.
3060 ** gdb.lookup_symbol can now work when there is no current frame.
3062 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3063 the source at which the symbol was defined.
3065 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3066 method 'value'. The former indicates whether the symbol needs a
3067 frame in order to compute its value, and the latter computes the
3070 ** A new method 'referenced_value' on gdb.Value objects which can
3071 dereference pointer as well as C++ reference values.
3073 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3074 which return the global and static blocks (as gdb.Block objects),
3075 of the underlying symbol table, respectively.
3077 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3078 object associated with a PC value.
3080 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3081 of the address range occupied by code for the current source line.
3083 * Go language support.
3084 GDB now supports debugging programs written in the Go programming
3087 * GDBserver now supports stdio connections.
3088 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3090 * The binary "gdbtui" can no longer be built or installed.
3091 Use "gdb -tui" instead.
3093 * GDB will now print "flag" enums specially. A flag enum is one where
3094 all the enumerator values have no bits in common when pairwise
3095 "and"ed. When printing a value whose type is a flag enum, GDB will
3096 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3097 (gdb) print (enum E) 3
3100 * The filename part of a linespec will now match trailing components
3101 of a source file name. For example, "break gcc/expr.c:1000" will
3102 now set a breakpoint in build/gcc/expr.c, but not
3103 build/libcpp/expr.c.
3105 * The "info proc" and "generate-core-file" commands will now also
3106 work on remote targets connected to GDBserver on Linux.
3108 * The command "info catch" has been removed. It has been disabled
3109 since December 2007.
3111 * The "catch exception" and "catch assert" commands now accept
3112 a condition at the end of the command, much like the "break"
3113 command does. For instance:
3115 (gdb) catch exception Constraint_Error if Barrier = True
3117 Previously, it was possible to add a condition to such catchpoints,
3118 but it had to be done as a second step, after the catchpoint had been
3119 created, using the "condition" command.
3121 * The "info static-tracepoint-marker" command will now also work on
3122 native Linux targets with in-process agent.
3124 * GDB can now set breakpoints on inlined functions.
3126 * The .gdb_index section has been updated to include symbols for
3127 inlined functions. GDB will ignore older .gdb_index sections by
3128 default, which could cause symbol files to be loaded more slowly
3129 until their .gdb_index sections can be recreated. The new command
3130 "set use-deprecated-index-sections on" will cause GDB to use any older
3131 .gdb_index sections it finds. This will restore performance, but the
3132 ability to set breakpoints on inlined functions will be lost in symbol
3133 files with older .gdb_index sections.
3135 The .gdb_index section has also been updated to record more information
3136 about each symbol. This speeds up the "info variables", "info functions"
3137 and "info types" commands when used with programs having the .gdb_index
3138 section, as well as speeding up debugging with shared libraries using
3139 the .gdb_index section.
3141 * Ada support for GDB/MI Variable Objects has been added.
3143 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3148 ** New command -info-os is the MI equivalent of "info os".
3150 ** Output logs ("set logging" and related) now include MI output.
3154 ** "set use-deprecated-index-sections on|off"
3155 "show use-deprecated-index-sections on|off"
3156 Controls the use of deprecated .gdb_index sections.
3158 ** "catch load" and "catch unload" can be used to stop when a shared
3159 library is loaded or unloaded, respectively.
3161 ** "enable count" can be used to auto-disable a breakpoint after
3164 ** "info vtbl" can be used to show the virtual method tables for
3165 C++ and Java objects.
3167 ** "explore" and its sub commands "explore value" and "explore type"
3168 can be used to recursively explore values and types of
3169 expressions. These commands are available only if GDB is
3170 configured with '--with-python'.
3172 ** "info auto-load" shows status of all kinds of auto-loaded files,
3173 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3174 sequences of commands files, "info auto-load python-scripts"
3175 shows status of auto-loading Python script files,
3176 "info auto-load local-gdbinit" shows status of loading init file
3177 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3178 status of inferior specific thread debugging shared library loading.
3180 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3181 and "show auto-load-scripts" commands have been deprecated, use their
3182 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3183 and "show auto-load python-scripts" counterparts instead.
3185 ** "dprintf location,format,args..." creates a dynamic printf, which
3186 is basically a breakpoint that does a printf and immediately
3187 resumes your program's execution, so it is like a printf that you
3188 can insert dynamically at runtime instead of at compiletime.
3190 ** "set print symbol"
3192 Controls whether GDB attempts to display the symbol, if any,
3193 corresponding to addresses it prints. This defaults to "on", but
3194 you can set it to "off" to restore GDB's previous behavior.
3196 * Deprecated commands
3198 ** For the Renesas Super-H architecture, the "regs" command has been
3199 deprecated, and "info all-registers" should be used instead.
3203 Renesas RL78 rl78-*-elf
3204 HP OpenVMS ia64 ia64-hp-openvms*
3206 * GDBserver supports evaluation of breakpoint conditions. When
3207 support is advertised by GDBserver, GDB may be told to send the
3208 breakpoint conditions in bytecode form to GDBserver. GDBserver
3209 will only report the breakpoint trigger to GDB when its condition
3214 set mips compression
3215 show mips compression
3216 Select the compressed ISA encoding used in functions that have no symbol
3217 information available. The encoding can be set to either of:
3220 and is updated automatically from ELF file flags if available.
3222 set breakpoint condition-evaluation
3223 show breakpoint condition-evaluation
3224 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3225 GDBserver ("target"). Default option "auto" chooses the most efficient
3227 This option can improve debugger efficiency depending on the speed of the
3231 Disable auto-loading globally.
3234 Show auto-loading setting of all kinds of auto-loaded files.
3236 set auto-load gdb-scripts on|off
3237 show auto-load gdb-scripts
3238 Control auto-loading of GDB canned sequences of commands files.
3240 set auto-load python-scripts on|off
3241 show auto-load python-scripts
3242 Control auto-loading of Python script files.
3244 set auto-load local-gdbinit on|off
3245 show auto-load local-gdbinit
3246 Control loading of init file (.gdbinit) from current directory.
3248 set auto-load libthread-db on|off
3249 show auto-load libthread-db
3250 Control auto-loading of inferior specific thread debugging shared library.
3252 set auto-load scripts-directory <dir1>[:<dir2>...]
3253 show auto-load scripts-directory
3254 Set a list of directories from which to load auto-loaded scripts.
3255 Automatically loaded Python scripts and GDB scripts are located in one
3256 of the directories listed by this option.
3257 The delimiter (':' above) may differ according to the host platform.
3259 set auto-load safe-path <dir1>[:<dir2>...]
3260 show auto-load safe-path
3261 Set a list of directories from which it is safe to auto-load files.
3262 The delimiter (':' above) may differ according to the host platform.
3264 set debug auto-load on|off
3265 show debug auto-load
3266 Control display of debugging info for auto-loading the files above.
3268 set dprintf-style gdb|call|agent
3270 Control the way in which a dynamic printf is performed; "gdb"
3271 requests a GDB printf command, while "call" causes dprintf to call a
3272 function in the inferior. "agent" requests that the target agent
3273 (such as GDBserver) do the printing.
3275 set dprintf-function <expr>
3276 show dprintf-function
3277 set dprintf-channel <expr>
3278 show dprintf-channel
3279 Set the function and optional first argument to the call when using
3280 the "call" style of dynamic printf.
3282 set disconnected-dprintf on|off
3283 show disconnected-dprintf
3284 Control whether agent-style dynamic printfs continue to be in effect
3285 after GDB disconnects.
3287 * New configure options
3289 --with-auto-load-dir
3290 Configure default value for the 'set auto-load scripts-directory'
3291 setting above. It defaults to '$debugdir:$datadir/auto-load',
3292 $debugdir representing global debugging info directories (available
3293 via 'show debug-file-directory') and $datadir representing GDB's data
3294 directory (available via 'show data-directory').
3296 --with-auto-load-safe-path
3297 Configure default value for the 'set auto-load safe-path' setting
3298 above. It defaults to the --with-auto-load-dir setting.
3300 --without-auto-load-safe-path
3301 Set 'set auto-load safe-path' to '/', effectively disabling this
3304 * New remote packets
3306 z0/z1 conditional breakpoints extension
3308 The z0/z1 breakpoint insertion packets have been extended to carry
3309 a list of conditional expressions over to the remote stub depending on the
3310 condition evaluation mode. The use of this extension can be controlled
3311 via the "set remote conditional-breakpoints-packet" command.
3315 Specify the signals which the remote stub may pass to the debugged
3316 program without GDB involvement.
3318 * New command line options
3320 --init-command=FILE, -ix Like --command, -x but execute it
3321 before loading inferior.
3322 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3323 execute it before loading inferior.
3325 *** Changes in GDB 7.4
3327 * GDB now handles ambiguous linespecs more consistently; the existing
3328 FILE:LINE support has been expanded to other types of linespecs. A
3329 breakpoint will now be set on all matching locations in all
3330 inferiors, and locations will be added or removed according to
3333 * GDB now allows you to skip uninteresting functions and files when
3334 stepping with the "skip function" and "skip file" commands.
3336 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3337 and "show remote hardware-watchpoint-length-limit". These allows to
3338 set or show the maximum length limit (in bytes) of a remote
3339 target hardware watchpoint.
3341 This allows e.g. to use "unlimited" hardware watchpoints with the
3342 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3343 watchpoints are slower than real hardware watchpoints but are
3344 significantly faster than gdb software watchpoints.
3348 ** The register_pretty_printer function in module gdb.printing now takes
3349 an optional `replace' argument. If True, the new printer replaces any
3352 ** The "maint set python print-stack on|off" command has been
3353 deprecated and will be deleted in GDB 7.5.
3354 A new command: "set python print-stack none|full|message" has
3355 replaced it. Additionally, the default for "print-stack" is
3356 now "message", which just prints the error message without
3359 ** A prompt substitution hook (prompt_hook) is now available to the
3362 ** A new Python module, gdb.prompt has been added to the GDB Python
3363 modules library. This module provides functionality for
3364 escape sequences in prompts (used by set/show
3365 extended-prompt). These escape sequences are replaced by their
3366 corresponding value.
3368 ** Python commands and convenience-functions located in
3369 'data-directory'/python/gdb/command and
3370 'data-directory'/python/gdb/function are now automatically loaded
3373 ** Blocks now provide four new attributes. global_block and
3374 static_block will return the global and static blocks
3375 respectively. is_static and is_global are boolean attributes
3376 that indicate if the block is one of those two types.
3378 ** Symbols now provide the "type" attribute, the type of the symbol.
3380 ** The "gdb.breakpoint" function has been deprecated in favor of
3383 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3384 of a function. This class is based on the "finish" command
3385 available in the CLI.
3387 ** Type objects for struct and union types now allow access to
3388 the fields using standard Python dictionary (mapping) methods.
3389 For example, "some_type['myfield']" now works, as does
3390 "some_type.items()".
3392 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3395 ** A new function, "deep_items" has been added to the gdb.types
3396 module in the GDB Python modules library. This function returns
3397 an iterator over the fields of a struct or union type. Unlike
3398 the standard Python "iteritems" method, it will recursively traverse
3399 any anonymous fields.
3403 ** "*stopped" events can report several new "reason"s, such as
3406 ** Breakpoint changes are now notified using new async records, like
3407 "=breakpoint-modified".
3409 ** New command -ada-task-info.
3411 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3412 $sdir specifies the default system locations of shared libraries.
3413 $pdir specifies the directory where the libpthread used by the application
3416 GDB no longer looks in $sdir and $pdir after it has searched the directories
3417 mentioned in libthread-db-search-path. If you want to search those
3418 directories, they must be specified in libthread-db-search-path.
3419 The default value of libthread-db-search-path on GNU/Linux and Solaris
3420 systems is now "$sdir:$pdir".
3422 $pdir is not supported by gdbserver, it is currently ignored.
3423 $sdir is supported by gdbserver.
3425 * New configure option --with-iconv-bin.
3426 When using the internationalization support like the one in the GNU C
3427 library, GDB will invoke the "iconv" program to get a list of supported
3428 character sets. If this program lives in a non-standard location, one can
3429 use this option to specify where to find it.
3431 * When natively debugging programs on PowerPC BookE processors running
3432 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3433 watchpoints, which specify a mask in addition to an address to watch.
3434 The mask specifies that some bits of an address (the bits which are
3435 reset in the mask) should be ignored when matching the address accessed
3436 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3437 section in the user manual for more details.
3439 * The new option --once causes GDBserver to stop listening for connections once
3440 the first connection is made. The listening port used by GDBserver will
3441 become available after that.
3443 * New commands "info macros" and "alias" have been added.
3445 * New function parameters suffix @entry specifies value of function parameter
3446 at the time the function got called. Entry values are available only since
3452 "!" is now an alias of the "shell" command.
3453 Note that no space is needed between "!" and SHELL COMMAND.
3457 watch EXPRESSION mask MASK_VALUE
3458 The watch command now supports the mask argument which allows creation
3459 of masked watchpoints, if the current architecture supports this feature.
3461 info auto-load-scripts [REGEXP]
3462 This command was formerly named "maintenance print section-scripts".
3463 It is now generally useful and is no longer a maintenance-only command.
3465 info macro [-all] [--] MACRO
3466 The info macro command has new options `-all' and `--'. The first for
3467 printing all definitions of a macro. The second for explicitly specifying
3468 the end of arguments and the beginning of the macro name in case the macro
3469 name starts with a hyphen.
3471 collect[/s] EXPRESSIONS
3472 The tracepoint collect command now takes an optional modifier "/s"
3473 that directs it to dereference pointer-to-character types and
3474 collect the bytes of memory up to a zero byte. The behavior is
3475 similar to what you see when you use the regular print command on a
3476 string. An optional integer following the "/s" sets a bound on the
3477 number of bytes that will be collected.
3480 The trace start command now interprets any supplied arguments as a
3481 note to be recorded with the trace run, with an effect similar to
3482 setting the variable trace-notes.
3485 The trace stop command now interprets any arguments as a note to be
3486 mentioned along with the tstatus report that the trace was stopped
3487 with a command. The effect is similar to setting the variable
3490 * Tracepoints can now be enabled and disabled at any time after a trace
3491 experiment has been started using the standard "enable" and "disable"
3492 commands. It is now possible to start a trace experiment with no enabled
3493 tracepoints; GDB will display a warning, but will allow the experiment to
3494 begin, assuming that tracepoints will be enabled as needed while the trace
3497 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3498 locations with 4-byte instructions, when they were previously
3499 limited to locations with instructions of 5 bytes or longer.
3503 set debug dwarf2-read
3504 show debug dwarf2-read
3505 Turns on or off display of debugging messages related to reading
3506 DWARF debug info. The default is off.
3508 set debug symtab-create
3509 show debug symtab-create
3510 Turns on or off display of debugging messages related to symbol table
3511 creation. The default is off.
3514 show extended-prompt
3515 Set the GDB prompt, and allow escape sequences to be inserted to
3516 display miscellaneous information (see 'help set extended-prompt'
3517 for the list of sequences). This prompt (and any information
3518 accessed through the escape sequences) is updated every time the
3519 prompt is displayed.
3521 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3522 show print entry-values
3523 Set printing of frame argument values at function entry. In some cases
3524 GDB can determine the value of function argument which was passed by the
3525 function caller, even if the value was modified inside the called function.
3527 set debug entry-values
3528 show debug entry-values
3529 Control display of debugging info for determining frame argument values at
3530 function entry and virtual tail call frames.
3532 set basenames-may-differ
3533 show basenames-may-differ
3534 Set whether a source file may have multiple base names.
3535 (A "base name" is the name of a file with the directory part removed.
3536 Example: The base name of "/home/user/hello.c" is "hello.c".)
3537 If set, GDB will canonicalize file names (e.g., expand symlinks)
3538 before comparing them. Canonicalization is an expensive operation,
3539 but it allows the same file be known by more than one base name.
3540 If not set (the default), all source files are assumed to have just
3541 one base name, and gdb will do file name comparisons more efficiently.
3547 Set a user name and notes for the current and any future trace runs.
3548 This is useful for long-running and/or disconnected traces, to
3549 inform others (or yourself) as to who is running the trace, supply
3550 contact information, or otherwise explain what is going on.
3552 set trace-stop-notes
3553 show trace-stop-notes
3554 Set a note attached to the trace run, that is displayed when the
3555 trace has been stopped by a tstop command. This is useful for
3556 instance as an explanation, if you are stopping a trace run that was
3557 started by someone else.
3559 * New remote packets
3563 Dynamically enable a tracepoint in a started trace experiment.
3567 Dynamically disable a tracepoint in a started trace experiment.
3571 Set the user and notes of the trace run.
3575 Query the current status of a tracepoint.
3579 Query the minimum length of instruction at which a fast tracepoint may
3582 * Dcache size (number of lines) and line-size are now runtime-configurable
3583 via "set dcache line" and "set dcache line-size" commands.
3587 Texas Instruments TMS320C6x tic6x-*-*
3591 Renesas RL78 rl78-*-elf
3593 *** Changes in GDB 7.3.1
3595 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3597 *** Changes in GDB 7.3
3599 * GDB has a new command: "thread find [REGEXP]".
3600 It finds the thread id whose name, target id, or thread extra info
3601 matches the given regular expression.
3603 * The "catch syscall" command now works on mips*-linux* targets.
3605 * The -data-disassemble MI command now supports modes 2 and 3 for
3606 dumping the instruction opcodes.
3608 * New command line options
3610 -data-directory DIR Specify DIR as the "data-directory".
3611 This is mostly for testing purposes.
3613 * The "maint set python auto-load on|off" command has been renamed to
3614 "set auto-load-scripts on|off".
3616 * GDB has a new command: "set directories".
3617 It is like the "dir" command except that it replaces the
3618 source path list instead of augmenting it.
3620 * GDB now understands thread names.
3622 On GNU/Linux, "info threads" will display the thread name as set by
3623 prctl or pthread_setname_np.
3625 There is also a new command, "thread name", which can be used to
3626 assign a name internally for GDB to display.
3629 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3630 has been integrated into GDB.
3634 ** The function gdb.Write now accepts an optional keyword 'stream'.
3635 This keyword, when provided, will direct the output to either
3636 stdout, stderr, or GDB's logging output.
3638 ** Parameters can now be be sub-classed in Python, and in particular
3639 you may implement the get_set_doc and get_show_doc functions.
3640 This improves how Parameter set/show documentation is processed
3641 and allows for more dynamic content.
3643 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3644 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3645 have an is_valid method.
3647 ** Breakpoints can now be sub-classed in Python, and in particular
3648 you may implement a 'stop' function that is executed each time
3649 the inferior reaches that breakpoint.
3651 ** New function gdb.lookup_global_symbol looks up a global symbol.
3653 ** GDB values in Python are now callable if the value represents a
3654 function. For example, if 'some_value' represents a function that
3655 takes two integer parameters and returns a value, you can call
3656 that function like so:
3658 result = some_value (10,20)
3660 ** Module gdb.types has been added.
3661 It contains a collection of utilities for working with gdb.Types objects:
3662 get_basic_type, has_field, make_enum_dict.
3664 ** Module gdb.printing has been added.
3665 It contains utilities for writing and registering pretty-printers.
3666 New classes: PrettyPrinter, SubPrettyPrinter,
3667 RegexpCollectionPrettyPrinter.
3668 New function: register_pretty_printer.
3670 ** New commands "info pretty-printers", "enable pretty-printer" and
3671 "disable pretty-printer" have been added.
3673 ** gdb.parameter("directories") is now available.
3675 ** New function gdb.newest_frame returns the newest frame in the
3678 ** The gdb.InferiorThread class has a new "name" attribute. This
3679 holds the thread's name.
3681 ** Python Support for Inferior events.
3682 Python scripts can add observers to be notified of events
3683 occurring in the process being debugged.
3684 The following events are currently supported:
3685 - gdb.events.cont Continue event.
3686 - gdb.events.exited Inferior exited event.
3687 - gdb.events.stop Signal received, and Breakpoint hit events.
3691 ** GDB now puts template parameters in scope when debugging in an
3692 instantiation. For example, if you have:
3694 template<int X> int func (void) { return X; }
3696 then if you step into func<5>, "print X" will show "5". This
3697 feature requires proper debuginfo support from the compiler; it
3698 was added to GCC 4.5.
3700 ** The motion commands "next", "finish", "until", and "advance" now
3701 work better when exceptions are thrown. In particular, GDB will
3702 no longer lose control of the inferior; instead, the GDB will
3703 stop the inferior at the point at which the exception is caught.
3704 This functionality requires a change in the exception handling
3705 code that was introduced in GCC 4.5.
3707 * GDB now follows GCC's rules on accessing volatile objects when
3708 reading or writing target state during expression evaluation.
3709 One notable difference to prior behavior is that "print x = 0"
3710 no longer generates a read of x; the value of the assignment is
3711 now always taken directly from the value being assigned.
3713 * GDB now has some support for using labels in the program's source in
3714 linespecs. For instance, you can use "advance label" to continue
3715 execution to a label.
3717 * GDB now has support for reading and writing a new .gdb_index
3718 section. This section holds a fast index of DWARF debugging
3719 information and can be used to greatly speed up GDB startup and
3720 operation. See the documentation for `save gdb-index' for details.
3722 * The "watch" command now accepts an optional "-location" argument.
3723 When used, this causes GDB to watch the memory referred to by the
3724 expression. Such a watchpoint is never deleted due to it going out
3727 * GDB now supports thread debugging of core dumps on GNU/Linux.
3729 GDB now activates thread debugging using the libthread_db library
3730 when debugging GNU/Linux core dumps, similarly to when debugging
3731 live processes. As a result, when debugging a core dump file, GDB
3732 is now able to display pthread_t ids of threads. For example, "info
3733 threads" shows the same output as when debugging the process when it
3734 was live. In earlier releases, you'd see something like this:
3737 * 1 LWP 6780 main () at main.c:10
3739 While now you see this:
3742 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3744 It is also now possible to inspect TLS variables when debugging core
3747 When debugging a core dump generated on a machine other than the one
3748 used to run GDB, you may need to point GDB at the correct
3749 libthread_db library with the "set libthread-db-search-path"
3750 command. See the user manual for more details on this command.
3752 * When natively debugging programs on PowerPC BookE processors running
3753 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3754 which stop execution of the inferior whenever it executes an instruction
3755 at any address within the specified range. See the "PowerPC Embedded"
3756 section in the user manual for more details.
3758 * New features in the GDB remote stub, GDBserver
3760 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3761 and i686 LynxOS (version 5.x).
3763 ** GDBserver is now supported on Blackfin Linux.
3765 * New native configurations
3767 ia64 HP-UX ia64-*-hpux*
3771 Analog Devices, Inc. Blackfin Processor bfin-*
3773 * Ada task switching is now supported on sparc-elf targets when
3774 debugging a program using the Ravenscar Profile. For more information,
3775 see the "Tasking Support when using the Ravenscar Profile" section
3776 in the GDB user manual.
3778 * Guile support was removed.
3780 * New features in the GNU simulator
3782 ** The --map-info flag lists all known core mappings.
3784 ** CFI flashes may be simulated via the "cfi" device.
3786 *** Changes in GDB 7.2
3788 * Shared library support for remote targets by default
3790 When GDB is configured for a generic, non-OS specific target, like
3791 for example, --target=arm-eabi or one of the many *-*-elf targets,
3792 GDB now queries remote stubs for loaded shared libraries using the
3793 `qXfer:libraries:read' packet. Previously, shared library support
3794 was always disabled for such configurations.
3798 ** Argument Dependent Lookup (ADL)
3800 In C++ ADL lookup directs function search to the namespaces of its
3801 arguments even if the namespace has not been imported.
3811 Here the compiler will search for `foo' in the namespace of 'b'
3812 and find A::foo. GDB now supports this. This construct is commonly
3813 used in the Standard Template Library for operators.
3815 ** Improved User Defined Operator Support
3817 In addition to member operators, GDB now supports lookup of operators
3818 defined in a namespace and imported with a `using' directive, operators
3819 defined in the global scope, operators imported implicitly from an
3820 anonymous namespace, and the ADL operators mentioned in the previous
3822 GDB now also supports proper overload resolution for all the previously
3823 mentioned flavors of operators.
3825 ** static const class members
3827 Printing of static const class members that are initialized in the
3828 class definition has been fixed.
3830 * Windows Thread Information Block access.
3832 On Windows targets, GDB now supports displaying the Windows Thread
3833 Information Block (TIB) structure. This structure is visible either
3834 by using the new command `info w32 thread-information-block' or, by
3835 dereferencing the new convenience variable named `$_tlb', a
3836 thread-specific pointer to the TIB. This feature is also supported
3837 when remote debugging using GDBserver.
3839 * Static tracepoints
3841 Static tracepoints are calls in the user program into a tracing
3842 library. One such library is a port of the LTTng kernel tracer to
3843 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3844 When debugging with GDBserver, GDB now supports combining the GDB
3845 tracepoint machinery with such libraries. For example: the user can
3846 use GDB to probe a static tracepoint marker (a call from the user
3847 program into the tracing library) with the new "strace" command (see
3848 "New commands" below). This creates a "static tracepoint" in the
3849 breakpoint list, that can be manipulated with the same feature set
3850 as fast and regular tracepoints. E.g., collect registers, local and
3851 global variables, collect trace state variables, and define
3852 tracepoint conditions. In addition, the user can collect extra
3853 static tracepoint marker specific data, by collecting the new
3854 $_sdata internal variable. When analyzing the trace buffer, you can
3855 inspect $_sdata like any other variable available to GDB. For more
3856 information, see the "Tracepoints" chapter in GDB user manual. New
3857 remote packets have been defined to support static tracepoints, see
3858 the "New remote packets" section below.
3860 * Better reconstruction of tracepoints after disconnected tracing
3862 GDB will attempt to download the original source form of tracepoint
3863 definitions when starting a trace run, and then will upload these
3864 upon reconnection to the target, resulting in a more accurate
3865 reconstruction of the tracepoints that are in use on the target.
3869 You can now exercise direct control over the ways that GDB can
3870 affect your program. For instance, you can disallow the setting of
3871 breakpoints, so that the program can run continuously (assuming
3872 non-stop mode). In addition, the "observer" variable is available
3873 to switch all of the different controls; in observer mode, GDB
3874 cannot affect the target's behavior at all, which is useful for
3875 tasks like diagnosing live systems in the field.
3877 * The new convenience variable $_thread holds the number of the
3880 * New remote packets
3884 Return the address of the Windows Thread Information Block of a given thread.
3888 In response to several of the tracepoint packets, the target may now
3889 also respond with a number of intermediate `qRelocInsn' request
3890 packets before the final result packet, to have GDB handle
3891 relocating an instruction to execute at a different address. This
3892 is particularly useful for stubs that support fast tracepoints. GDB
3893 reports support for this feature in the qSupported packet.
3897 List static tracepoint markers in the target program.
3901 List static tracepoint markers at a given address in the target
3904 qXfer:statictrace:read
3906 Read the static trace data collected (by a `collect $_sdata'
3907 tracepoint action). The remote stub reports support for this packet
3908 to gdb's qSupported query.
3912 Send the current settings of GDB's permission flags.
3916 Send part of the source (textual) form of a tracepoint definition,
3917 which includes location, conditional, and action list.
3919 * The source command now accepts a -s option to force searching for the
3920 script in the source search path even if the script name specifies
3923 * New features in the GDB remote stub, GDBserver
3925 - GDBserver now support tracepoints (including fast tracepoints, and
3926 static tracepoints). The feature is currently supported by the
3927 i386-linux and amd64-linux builds. See the "Tracepoints support
3928 in gdbserver" section in the manual for more information.
3930 GDBserver JIT compiles the tracepoint's conditional agent
3931 expression bytecode into native code whenever possible for low
3932 overhead dynamic tracepoints conditionals. For such tracepoints,
3933 an expression that examines program state is evaluated when the
3934 tracepoint is reached, in order to determine whether to capture
3935 trace data. If the condition is simple and false, processing the
3936 tracepoint finishes very quickly and no data is gathered.
3938 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3939 for static tracepoints support.
3941 - GDBserver now supports x86_64 Windows 64-bit debugging.
3943 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3944 it understands register description.
3946 * The --batch flag now disables pagination and queries.
3948 * X86 general purpose registers
3950 GDB now supports reading/writing byte, word and double-word x86
3951 general purpose registers directly. This means you can use, say,
3952 $ah or $ax to refer, respectively, to the byte register AH and
3953 16-bit word register AX that are actually portions of the 32-bit
3954 register EAX or 64-bit register RAX.
3956 * The `commands' command now accepts a range of breakpoints to modify.
3957 A plain `commands' following a command that creates multiple
3958 breakpoints affects all the breakpoints set by that command. This
3959 applies to breakpoints set by `rbreak', and also applies when a
3960 single `break' command creates multiple breakpoints (e.g.,
3961 breakpoints on overloaded c++ functions).
3963 * The `rbreak' command now accepts a filename specification as part of
3964 its argument, limiting the functions selected by the regex to those
3965 in the specified file.
3967 * Support for remote debugging Windows and SymbianOS shared libraries
3968 from Unix hosts has been improved. Non Windows GDB builds now can
3969 understand target reported file names that follow MS-DOS based file
3970 system semantics, such as file names that include drive letters and
3971 use the backslash character as directory separator. This makes it
3972 possible to transparently use the "set sysroot" and "set
3973 solib-search-path" on Unix hosts to point as host copies of the
3974 target's shared libraries. See the new command "set
3975 target-file-system-kind" described below, and the "Commands to
3976 specify files" section in the user manual for more information.
3980 eval template, expressions...
3981 Convert the values of one or more expressions under the control
3982 of the string template to a command line, and call it.
3984 set target-file-system-kind unix|dos-based|auto
3985 show target-file-system-kind
3986 Set or show the assumed file system kind for target reported file
3989 save breakpoints <filename>
3990 Save all current breakpoint definitions to a file suitable for use
3991 in a later debugging session. To read the saved breakpoint
3992 definitions, use the `source' command.
3994 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3997 info static-tracepoint-markers
3998 Display information about static tracepoint markers in the target.
4000 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4001 Define a static tracepoint by probing a marker at the given
4002 function, line, address, or marker ID.
4006 Enable and disable observer mode.
4008 set may-write-registers on|off
4009 set may-write-memory on|off
4010 set may-insert-breakpoints on|off
4011 set may-insert-tracepoints on|off
4012 set may-insert-fast-tracepoints on|off
4013 set may-interrupt on|off
4014 Set individual permissions for GDB effects on the target. Note that
4015 some of these settings can have undesirable or surprising
4016 consequences, particularly when changed in the middle of a session.
4017 For instance, disabling the writing of memory can prevent
4018 breakpoints from being inserted, cause single-stepping to fail, or
4019 even crash your program, if you disable after breakpoints have been
4020 inserted. However, GDB should not crash.
4022 set record memory-query on|off
4023 show record memory-query
4024 Control whether to stop the inferior if memory changes caused
4025 by an instruction cannot be recorded.
4030 The disassemble command now supports "start,+length" form of two arguments.
4034 ** GDB now provides a new directory location, called the python directory,
4035 where Python scripts written for GDB can be installed. The location
4036 of that directory is <data-directory>/python, where <data-directory>
4037 is the GDB data directory. For more details, see section `Scripting
4038 GDB using Python' in the manual.
4040 ** The GDB Python API now has access to breakpoints, symbols, symbol
4041 tables, program spaces, inferiors, threads and frame's code blocks.
4042 Additionally, GDB Parameters can now be created from the API, and
4043 manipulated via set/show in the CLI.
4045 ** New functions gdb.target_charset, gdb.target_wide_charset,
4046 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4048 ** New exception gdb.GdbError.
4050 ** Pretty-printers are now also looked up in the current program space.
4052 ** Pretty-printers can now be individually enabled and disabled.
4054 ** GDB now looks for names of Python scripts to auto-load in a
4055 special section named `.debug_gdb_scripts', in addition to looking
4056 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4058 * Tracepoint actions were unified with breakpoint commands. In particular,
4059 there are no longer differences in "info break" output for breakpoints and
4060 tracepoints and the "commands" command can be used for both tracepoints and
4061 regular breakpoints.
4065 ARM Symbian arm*-*-symbianelf*
4067 * D language support.
4068 GDB now supports debugging programs written in the D programming
4071 * GDB now supports the extended ptrace interface for PowerPC which is
4072 available since Linux kernel version 2.6.34. This automatically enables
4073 any hardware breakpoints and additional hardware watchpoints available in
4074 the processor. The old ptrace interface exposes just one hardware
4075 watchpoint and no hardware breakpoints.
4077 * GDB is now able to use the Data Value Compare (DVC) register available on
4078 embedded PowerPC processors to implement in hardware simple watchpoint
4079 conditions of the form:
4081 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4083 This works in native GDB running on Linux kernels with the extended ptrace
4084 interface mentioned above.
4086 *** Changes in GDB 7.1
4090 ** Namespace Support
4092 GDB now supports importing of namespaces in C++. This enables the
4093 user to inspect variables from imported namespaces. Support for
4094 namepace aliasing has also been added. So, if a namespace is
4095 aliased in the current scope (e.g. namepace C=A; ) the user can
4096 print variables using the alias (e.g. (gdb) print C::x).
4100 All known bugs relating to the printing of virtual base class were
4101 fixed. It is now possible to call overloaded static methods using a
4106 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4107 and reinterpret_cast<> are now handled by the C++ expression parser.
4111 Xilinx MicroBlaze microblaze-*-*
4116 Xilinx MicroBlaze microblaze
4119 * Multi-program debugging.
4121 GDB now has support for multi-program (a.k.a. multi-executable or
4122 multi-exec) debugging. This allows for debugging multiple inferiors
4123 simultaneously each running a different program under the same GDB
4124 session. See "Debugging Multiple Inferiors and Programs" in the
4125 manual for more information. This implied some user visible changes
4126 in the multi-inferior support. For example, "info inferiors" now
4127 lists inferiors that are not running yet or that have exited
4128 already. See also "New commands" and "New options" below.
4130 * New tracing features
4132 GDB's tracepoint facility now includes several new features:
4134 ** Trace state variables
4136 GDB tracepoints now include support for trace state variables, which
4137 are variables managed by the target agent during a tracing
4138 experiment. They are useful for tracepoints that trigger each
4139 other, so for instance one tracepoint can count hits in a variable,
4140 and then a second tracepoint has a condition that is true when the
4141 count reaches a particular value. Trace state variables share the
4142 $-syntax of GDB convenience variables, and can appear in both
4143 tracepoint actions and condition expressions. Use the "tvariable"
4144 command to create, and "info tvariables" to view; see "Trace State
4145 Variables" in the manual for more detail.
4149 GDB now includes an option for defining fast tracepoints, which
4150 targets may implement more efficiently, such as by installing a jump
4151 into the target agent rather than a trap instruction. The resulting
4152 speedup can be by two orders of magnitude or more, although the
4153 tradeoff is that some program locations on some target architectures
4154 might not allow fast tracepoint installation, for instance if the
4155 instruction to be replaced is shorter than the jump. To request a
4156 fast tracepoint, use the "ftrace" command, with syntax identical to
4157 the regular trace command.
4159 ** Disconnected tracing
4161 It is now possible to detach GDB from the target while it is running
4162 a trace experiment, then reconnect later to see how the experiment
4163 is going. In addition, a new variable disconnected-tracing lets you
4164 tell the target agent whether to continue running a trace if the
4165 connection is lost unexpectedly.
4169 GDB now has the ability to save the trace buffer into a file, and
4170 then use that file as a target, similarly to you can do with
4171 corefiles. You can select trace frames, print data that was
4172 collected in them, and use tstatus to display the state of the
4173 tracing run at the moment that it was saved. To create a trace
4174 file, use "tsave <filename>", and to use it, do "target tfile
4177 ** Circular trace buffer
4179 You can ask the target agent to handle the trace buffer as a
4180 circular buffer, discarding the oldest trace frames to make room for
4181 newer ones, by setting circular-trace-buffer to on. This feature may
4182 not be available for all target agents.
4187 The disassemble command, when invoked with two arguments, now requires
4188 the arguments to be comma-separated.
4191 The info variables command now displays variable definitions. Files
4192 which only declare a variable are not shown.
4195 The source command is now capable of sourcing Python scripts.
4196 This feature is dependent on the debugger being build with Python
4199 Related to this enhancement is also the introduction of a new command
4200 "set script-extension" (see below).
4202 * New commands (for set/show, see "New options" below)
4204 record save [<FILENAME>]
4205 Save a file (in core file format) containing the process record
4206 execution log for replay debugging at a later time.
4208 record restore <FILENAME>
4209 Restore the process record execution log that was saved at an
4210 earlier time, for replay debugging.
4212 add-inferior [-copies <N>] [-exec <FILENAME>]
4215 clone-inferior [-copies <N>] [ID]
4216 Make a new inferior ready to execute the same program another
4217 inferior has loaded.
4222 maint info program-spaces
4223 List the program spaces loaded into GDB.
4225 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4226 show remote interrupt-sequence
4227 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4228 as the sequence to the remote target in order to interrupt the execution.
4229 Ctrl-C is a default. Some system prefers BREAK which is high level of
4230 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4231 Magic SysRq g. It is BREAK signal and character 'g'.
4233 set remote interrupt-on-connect [on | off]
4234 show remote interrupt-on-connect
4235 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4236 remote target when gdb connects to it. This is needed when you debug
4239 set remotebreak [on | off]
4241 Deprecated. Use "set/show remote interrupt-sequence" instead.
4243 tvariable $NAME [ = EXP ]
4244 Create or modify a trace state variable.
4247 List trace state variables and their values.
4249 delete tvariable $NAME ...
4250 Delete one or more trace state variables.
4253 Evaluate the given expressions without collecting anything into the
4254 trace buffer. (Valid in tracepoint actions only.)
4256 ftrace FN / FILE:LINE / *ADDR
4257 Define a fast tracepoint at the given function, line, or address.
4259 * New expression syntax
4261 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4262 GDB now parses 0b101010 identically with 42.
4266 set follow-exec-mode new|same
4267 show follow-exec-mode
4268 Control whether GDB reuses the same inferior across an exec call or
4269 creates a new one. This is useful to be able to restart the old
4270 executable after the inferior having done an exec call.
4272 set default-collect EXPR, ...
4273 show default-collect
4274 Define a list of expressions to be collected at each tracepoint.
4275 This is a useful way to ensure essential items are not overlooked,
4276 such as registers or a critical global variable.
4278 set disconnected-tracing
4279 show disconnected-tracing
4280 If set to 1, the target is instructed to continue tracing if it
4281 loses its connection to GDB. If 0, the target is to stop tracing
4284 set circular-trace-buffer
4285 show circular-trace-buffer
4286 If set to on, the target is instructed to use a circular trace buffer
4287 and discard the oldest trace frames instead of stopping the trace due
4288 to a full trace buffer. If set to off, the trace stops when the buffer
4289 fills up. Some targets may not support this.
4291 set script-extension off|soft|strict
4292 show script-extension
4293 If set to "off", the debugger does not perform any script language
4294 recognition, and all sourced files are assumed to be GDB scripts.
4295 If set to "soft" (the default), files are sourced according to
4296 filename extension, falling back to GDB scripts if the first
4298 If set to "strict", files are sourced according to filename extension.
4300 set ada trust-PAD-over-XVS on|off
4301 show ada trust-PAD-over-XVS
4302 If off, activate a workaround against a bug in the debugging information
4303 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4304 the GCC sources for more information about the GNAT encoding and
4305 PAD types in particular). It is always safe to set this option to
4306 off, but this introduces a slight performance penalty. The default
4309 * Python API Improvements
4311 ** GDB provides the new class gdb.LazyString. This is useful in
4312 some pretty-printing cases. The new method gdb.Value.lazy_string
4313 provides a simple way to create objects of this type.
4315 ** The fields returned by gdb.Type.fields now have an
4316 `is_base_class' attribute.
4318 ** The new method gdb.Type.range returns the range of an array type.
4320 ** The new method gdb.parse_and_eval can be used to parse and
4321 evaluate an expression.
4323 * New remote packets
4326 Define a trace state variable.
4329 Get the current value of a trace state variable.
4332 Set desired tracing behavior upon disconnection.
4335 Set the trace buffer to be linear or circular.
4338 Get data about the tracepoints currently in use.
4342 Process record now works correctly with hardware watchpoints.
4344 Multiple bug fixes have been made to the mips-irix port, making it
4345 much more reliable. In particular:
4346 - Debugging threaded applications is now possible again. Previously,
4347 GDB would hang while starting the program, or while waiting for
4348 the program to stop at a breakpoint.
4349 - Attaching to a running process no longer hangs.
4350 - An error occurring while loading a core file has been fixed.
4351 - Changing the value of the PC register now works again. This fixes
4352 problems observed when using the "jump" command, or when calling
4353 a function from GDB, or even when assigning a new value to $pc.
4354 - With the "finish" and "return" commands, the return value for functions
4355 returning a small array is now correctly printed.
4356 - It is now possible to break on shared library code which gets executed
4357 during a shared library init phase (code executed while executing
4358 their .init section). Previously, the breakpoint would have no effect.
4359 - GDB is now able to backtrace through the signal handler for
4360 non-threaded programs.
4362 PIE (Position Independent Executable) programs debugging is now supported.
4363 This includes debugging execution of PIC (Position Independent Code) shared
4364 libraries although for that, it should be possible to run such libraries as an
4367 *** Changes in GDB 7.0
4369 * GDB now has an interface for JIT compilation. Applications that
4370 dynamically generate code can create symbol files in memory and register
4371 them with GDB. For users, the feature should work transparently, and
4372 for JIT developers, the interface is documented in the GDB manual in the
4373 "JIT Compilation Interface" chapter.
4375 * Tracepoints may now be conditional. The syntax is as for
4376 breakpoints; either an "if" clause appended to the "trace" command,
4377 or the "condition" command is available. GDB sends the condition to
4378 the target for evaluation using the same bytecode format as is used
4379 for tracepoint actions.
4381 * The disassemble command now supports: an optional /r modifier, print the
4382 raw instructions in hex as well as in symbolic form, and an optional /m
4383 modifier to print mixed source+assembly.
4385 * Process record and replay
4387 In a architecture environment that supports ``process record and
4388 replay'', ``process record and replay'' target can record a log of
4389 the process execution, and replay it with both forward and reverse
4392 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4393 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4394 set execution-direction {forward|reverse}, for targets that support
4397 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4398 feature is available with a native GDB running on kernel version
4401 * GDB now has support for multi-byte and wide character sets on the
4402 target. Strings whose character type is wchar_t, char16_t, or
4403 char32_t are now correctly printed. GDB supports wide- and unicode-
4404 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4405 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4406 `printf'. This feature requires iconv to work properly; if your
4407 system does not have a working iconv, GDB can use GNU libiconv. See
4408 the installation instructions for more information.
4410 * GDB now supports automatic retrieval of shared library files from
4411 remote targets. To use this feature, specify a system root that begins
4412 with the `remote:' prefix, either via the `set sysroot' command or via
4413 the `--with-sysroot' configure-time option.
4415 * "info sharedlibrary" now takes an optional regex of libraries to show,
4416 and it now reports if a shared library has no debugging information.
4418 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4419 now complete on file names.
4421 * When completing in expressions, gdb will attempt to limit
4422 completions to allowable structure or union fields, where appropriate.
4423 For instance, consider:
4425 # struct example { int f1; double f2; };
4426 # struct example variable;
4429 If the user types TAB at the end of this command line, the available
4430 completions will be "f1" and "f2".
4432 * Inlined functions are now supported. They show up in backtraces, and
4433 the "step", "next", and "finish" commands handle them automatically.
4435 * GDB now supports the token-splicing (##) and stringification (#)
4436 operators when expanding macros. It also supports variable-arity
4439 * GDB now supports inspecting extra signal information, exported by
4440 the new $_siginfo convenience variable. The feature is currently
4441 implemented on linux ARM, i386 and amd64.
4443 * GDB can now display the VFP floating point registers and NEON vector
4444 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4445 can provide these registers (requires Linux 2.6.30 or later). Remote
4446 and simulator targets may also provide them.
4448 * New remote packets
4451 Search memory for a sequence of bytes.
4454 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4455 operation over reliable transport links. Use of this packet is
4456 controlled by the `set remote noack-packet' command.
4459 Kill the process with the specified process ID. Use this in preference
4460 to `k' when multiprocess protocol extensions are supported.
4463 Obtains additional operating system information
4467 Read or write additional signal information.
4469 * Removed remote protocol undocumented extension
4471 An undocumented extension to the remote protocol's `S' stop reply
4472 packet that permitted the stub to pass a process id was removed.
4473 Remote servers should use the `T' stop reply packet instead.
4475 * GDB now supports multiple function calling conventions according to the
4476 DWARF-2 DW_AT_calling_convention function attribute.
4478 * The SH target utilizes the aforementioned change to distinguish between gcc
4479 and Renesas calling convention. It also adds the new CLI commands
4480 `set/show sh calling-convention'.
4482 * GDB can now read compressed debug sections, as produced by GNU gold
4483 with the --compress-debug-sections=zlib flag.
4485 * 64-bit core files are now supported on AIX.
4487 * Thread switching is now supported on Tru64.
4489 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4490 which will be allocated using malloc later in program execution.
4492 * The qXfer:libraries:read remote protocol packet now allows passing a
4493 list of section offsets.
4495 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4496 conditions handling signals delivered during attach or thread creation
4497 have also been fixed.
4499 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4500 From the user's standpoint, all unqualified instances of True and False
4501 are treated as the standard definitions, regardless of context.
4503 * GDB now parses C++ symbol and type names more flexibly. For
4506 template<typename T> class C { };
4509 GDB will now correctly handle all of:
4511 ptype C<char const *>
4512 ptype C<char const*>
4513 ptype C<const char *>
4514 ptype C<const char*>
4516 * New features in the GDB remote stub, gdbserver
4518 - The "--wrapper" command-line argument tells gdbserver to use a
4519 wrapper program to launch programs for debugging.
4521 - On PowerPC and S/390 targets, it is now possible to use a single
4522 gdbserver executable to debug both 32-bit and 64-bit programs.
4523 (This requires gdbserver itself to be built as a 64-bit executable.)
4525 - gdbserver uses the new noack protocol mode for TCP connections to
4526 reduce communications latency, if also supported and enabled in GDB.
4528 - Support for the sparc64-linux-gnu target is now included in
4531 - The amd64-linux build of gdbserver now supports debugging both
4532 32-bit and 64-bit programs.
4534 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4535 now support hardware watchpoints, and will use them automatically
4540 GDB now has support for scripting using Python. Whether this is
4541 available is determined at configure time.
4543 New GDB commands can now be written in Python.
4545 * Ada tasking support
4547 Ada tasks can now be inspected in GDB. The following commands have
4551 Print the list of Ada tasks.
4553 Print detailed information about task number N.
4555 Print the task number of the current task.
4557 Switch the context of debugging to task number N.
4559 * Support for user-defined prefixed commands. The "define" command can
4560 add new commands to existing prefixes, e.g. "target".
4562 * Multi-inferior, multi-process debugging.
4564 GDB now has generalized support for multi-inferior debugging. See
4565 "Debugging Multiple Inferiors" in the manual for more information.
4566 Although availability still depends on target support, the command
4567 set is more uniform now. The GNU/Linux specific multi-forks support
4568 has been migrated to this new framework. This implied some user
4569 visible changes; see "New commands" and also "Removed commands"
4572 * Target descriptions can now describe the target OS ABI. See the
4573 "Target Description Format" section in the user manual for more
4576 * Target descriptions can now describe "compatible" architectures
4577 to indicate that the target can execute applications for a different
4578 architecture in addition to those for the main target architecture.
4579 See the "Target Description Format" section in the user manual for
4582 * Multi-architecture debugging.
4584 GDB now includes general supports for debugging applications on
4585 hybrid systems that use more than one single processor architecture
4586 at the same time. Each such hybrid architecture still requires
4587 specific support to be added. The only hybrid architecture supported
4588 in this version of GDB is the Cell Broadband Engine.
4590 * GDB now supports integrated debugging of Cell/B.E. applications that
4591 use both the PPU and SPU architectures. To enable support for hybrid
4592 Cell/B.E. debugging, you need to configure GDB to support both the
4593 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4594 --enable-targets configure option.
4596 * Non-stop mode debugging.
4598 For some targets, GDB now supports an optional mode of operation in
4599 which you can examine stopped threads while other threads continue
4600 to execute freely. This is referred to as non-stop mode, with the
4601 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4602 section in the user manual for more information.
4604 To be able to support remote non-stop debugging, a remote stub needs
4605 to implement the non-stop mode remote protocol extensions, as
4606 described in the "Remote Non-Stop" section of the user manual. The
4607 GDB remote stub, gdbserver, has been adjusted to support these
4608 extensions on linux targets.
4610 * New commands (for set/show, see "New options" below)
4612 catch syscall [NAME(S) | NUMBER(S)]
4613 Catch system calls. Arguments, which should be names of system
4614 calls or their numbers, mean catch only those syscalls. Without
4615 arguments, every syscall will be caught. When the inferior issues
4616 any of the specified syscalls, GDB will stop and announce the system
4617 call, both when it is called and when its call returns. This
4618 feature is currently available with a native GDB running on the
4619 Linux Kernel, under the following architectures: x86, x86_64,
4620 PowerPC and PowerPC64.
4622 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4624 Search memory for a sequence of bytes.
4626 maint set python print-stack
4627 maint show python print-stack
4628 Show a stack trace when an error is encountered in a Python script.
4631 Invoke CODE by passing it to the Python interpreter.
4636 These allow macros to be defined, undefined, and listed
4640 Show operating system information about processes.
4643 List the inferiors currently under GDB's control.
4646 Switch focus to inferior number NUM.
4649 Detach from inferior number NUM.
4652 Kill inferior number NUM.
4656 set spu stop-on-load
4657 show spu stop-on-load
4658 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4660 set spu auto-flush-cache
4661 show spu auto-flush-cache
4662 Control whether to automatically flush the software-managed cache
4663 during Cell/B.E. debugging.
4665 set sh calling-convention
4666 show sh calling-convention
4667 Control the calling convention used when calling SH target functions.
4670 show debug timestamp
4671 Control display of timestamps with GDB debugging output.
4673 set disassemble-next-line
4674 show disassemble-next-line
4675 Control display of disassembled source lines or instructions when
4678 set remote noack-packet
4679 show remote noack-packet
4680 Set/show the use of remote protocol QStartNoAckMode packet. See above
4681 under "New remote packets."
4683 set remote query-attached-packet
4684 show remote query-attached-packet
4685 Control use of remote protocol `qAttached' (query-attached) packet.
4687 set remote read-siginfo-object
4688 show remote read-siginfo-object
4689 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4692 set remote write-siginfo-object
4693 show remote write-siginfo-object
4694 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4697 set remote reverse-continue
4698 show remote reverse-continue
4699 Control use of remote protocol 'bc' (reverse-continue) packet.
4701 set remote reverse-step
4702 show remote reverse-step
4703 Control use of remote protocol 'bs' (reverse-step) packet.
4705 set displaced-stepping
4706 show displaced-stepping
4707 Control displaced stepping mode. Displaced stepping is a way to
4708 single-step over breakpoints without removing them from the debuggee.
4709 Also known as "out-of-line single-stepping".
4712 show debug displaced
4713 Control display of debugging info for displaced stepping.
4715 maint set internal-error
4716 maint show internal-error
4717 Control what GDB does when an internal error is detected.
4719 maint set internal-warning
4720 maint show internal-warning
4721 Control what GDB does when an internal warning is detected.
4726 Use a wrapper program to launch programs for debugging.
4728 set multiple-symbols (all|ask|cancel)
4729 show multiple-symbols
4730 The value of this variable can be changed to adjust the debugger behavior
4731 when an expression or a breakpoint location contains an ambiguous symbol
4732 name (an overloaded function name, for instance).
4734 set breakpoint always-inserted
4735 show breakpoint always-inserted
4736 Keep breakpoints always inserted in the target, as opposed to inserting
4737 them when resuming the target, and removing them when the target stops.
4738 This option can improve debugger performance on slow remote targets.
4740 set arm fallback-mode (arm|thumb|auto)
4741 show arm fallback-mode
4742 set arm force-mode (arm|thumb|auto)
4744 These commands control how ARM GDB determines whether instructions
4745 are ARM or Thumb. The default for both settings is auto, which uses
4746 the current CPSR value for instructions without symbols; previous
4747 versions of GDB behaved as if "set arm fallback-mode arm".
4749 set disable-randomization
4750 show disable-randomization
4751 Standalone programs run with the virtual address space randomization enabled
4752 by default on some platforms. This option keeps the addresses stable across
4753 multiple debugging sessions.
4757 Control whether other threads are stopped or not when some thread hits
4762 Requests that asynchronous execution is enabled in the target, if available.
4763 In this case, it's possible to resume target in the background, and interact
4764 with GDB while the target is running. "show target-async" displays the
4765 current state of asynchronous execution of the target.
4767 set target-wide-charset
4768 show target-wide-charset
4769 The target-wide-charset is the name of the character set that GDB
4770 uses when printing characters whose type is wchar_t.
4772 set tcp auto-retry (on|off)
4774 set tcp connect-timeout
4775 show tcp connect-timeout
4776 These commands allow GDB to retry failed TCP connections to a remote stub
4777 with a specified timeout period; this is useful if the stub is launched
4778 in parallel with GDB but may not be ready to accept connections immediately.
4780 set libthread-db-search-path
4781 show libthread-db-search-path
4782 Control list of directories which GDB will search for appropriate
4785 set schedule-multiple (on|off)
4786 show schedule-multiple
4787 Allow GDB to resume all threads of all processes or only threads of
4788 the current process.
4792 Use more aggressive caching for accesses to the stack. This improves
4793 performance of remote debugging (particularly backtraces) without
4794 affecting correctness.
4796 set interactive-mode (on|off|auto)
4797 show interactive-mode
4798 Control whether GDB runs in interactive mode (on) or not (off).
4799 When in interactive mode, GDB waits for the user to answer all
4800 queries. Otherwise, GDB does not wait and assumes the default
4801 answer. When set to auto (the default), GDB determines which
4802 mode to use based on the stdin settings.
4807 For program forks, this is replaced by the new more generic `info
4808 inferiors' command. To list checkpoints, you can still use the
4809 `info checkpoints' command, which was an alias for the `info forks'
4813 Replaced by the new `inferior' command. To switch between
4814 checkpoints, you can still use the `restart' command, which was an
4815 alias for the `fork' command.
4818 This is removed, since some targets don't have a notion of
4819 processes. To switch between processes, you can still use the
4820 `inferior' command using GDB's own inferior number.
4823 For program forks, this is replaced by the new more generic `kill
4824 inferior' command. To delete a checkpoint, you can still use the
4825 `delete checkpoint' command, which was an alias for the `delete
4829 For program forks, this is replaced by the new more generic `detach
4830 inferior' command. To detach a checkpoint, you can still use the
4831 `detach checkpoint' command, which was an alias for the `detach
4834 * New native configurations
4836 x86/x86_64 Darwin i[34567]86-*-darwin*
4838 x86_64 MinGW x86_64-*-mingw*
4842 Lattice Mico32 lm32-*
4843 x86 DICOS i[34567]86-*-dicos*
4844 x86_64 DICOS x86_64-*-dicos*
4847 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4848 (mingw32ce) debugging.
4854 These commands were actually not implemented on any target.
4856 *** Changes in GDB 6.8
4858 * New native configurations
4860 NetBSD/hppa hppa*-*netbsd*
4861 Xtensa GNU/Linux xtensa*-*-linux*
4865 NetBSD/hppa hppa*-*-netbsd*
4866 Xtensa GNU/Linux xtensa*-*-linux*
4868 * Change in command line behavior -- corefiles vs. process ids.
4870 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4871 attaching to process NUMBER fails, GDB no longer attempts to open a
4872 core file named NUMBER. Attaching to a program using the -c option
4873 is no longer supported. Instead, use the '-p' or '--pid' options.
4875 * GDB can now be built as a native debugger for debugging Windows x86
4876 (mingw32) Portable Executable (PE) programs.
4878 * Pending breakpoints no longer change their number when their address
4881 * GDB now supports breakpoints with multiple locations,
4882 including breakpoints on C++ constructors, inside C++ templates,
4883 and in inlined functions.
4885 * GDB's ability to debug optimized code has been improved. GDB more
4886 accurately identifies function bodies and lexical blocks that occupy
4887 more than one contiguous range of addresses.
4889 * Target descriptions can now describe registers for PowerPC.
4891 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4892 registers on PowerPC targets.
4894 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4895 targets even when the libthread_db library is not available.
4897 * The GDB remote stub, gdbserver, now supports the new file transfer
4898 commands (remote put, remote get, and remote delete).
4900 * The GDB remote stub, gdbserver, now supports run and attach in
4901 extended-remote mode.
4903 * hppa*64*-*-hpux11* target broken
4904 The debugger is unable to start a program and fails with the following
4905 error: "Error trying to get information about dynamic linker".
4906 The gdb-6.7 release is also affected.
4908 * GDB now supports the --enable-targets= configure option to allow
4909 building a single GDB executable that supports multiple remote
4910 target architectures.
4912 * GDB now supports debugging C and C++ programs which use the
4913 Decimal Floating Point extension. In addition, the PowerPC target
4914 now has a set of pseudo-registers to inspect decimal float values
4915 stored in two consecutive float registers.
4917 * The -break-insert MI command can optionally create pending
4920 * Improved support for debugging Ada
4921 Many improvements to the Ada language support have been made. These
4923 - Better support for Ada2005 interface types
4924 - Improved handling of arrays and slices in general
4925 - Better support for Taft-amendment types
4926 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4928 - Improved command completion in Ada
4931 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4936 set print frame-arguments (all|scalars|none)
4937 show print frame-arguments
4938 The value of this variable can be changed to control which argument
4939 values should be printed by the debugger when displaying a frame.
4944 Transfer files to and from a remote target, and delete remote files.
4951 Transfer files to and from a remote target, and delete remote files.
4953 * New remote packets
4960 Open, close, read, write, and delete files on the remote system.
4963 Attach to an existing process on the remote system, in extended-remote
4967 Run a new process on the remote system, in extended-remote mode.
4969 *** Changes in GDB 6.7
4971 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4972 bfd, libiberty and opcodes, as revealed by static analysis donated by
4973 Coverity, Inc. (http://scan.coverity.com).
4975 * When looking up multiply-defined global symbols, GDB will now prefer the
4976 symbol definition in the current shared library if it was built using the
4977 -Bsymbolic linker option.
4979 * When the Text User Interface (TUI) is not configured, GDB will now
4980 recognize the -tui command-line option and print a message that the TUI
4983 * The GDB remote stub, gdbserver, now has lower overhead for high
4984 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4986 * GDB for MIPS targets now autodetects whether a remote target provides
4987 32-bit or 64-bit register values.
4989 * Support for C++ member pointers has been improved.
4991 * GDB now understands XML target descriptions, which specify the
4992 target's overall architecture. GDB can read a description from
4993 a local file or over the remote serial protocol.
4995 * Vectors of single-byte data use a new integer type which is not
4996 automatically displayed as character or string data.
4998 * The /s format now works with the print command. It displays
4999 arrays of single-byte integers and pointers to single-byte integers
5002 * Target descriptions can now describe target-specific registers,
5003 for architectures which have implemented the support (currently
5004 only ARM, M68K, and MIPS).
5006 * GDB and the GDB remote stub, gdbserver, now support the XScale
5009 * The GDB remote stub, gdbserver, has been updated to support
5010 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5011 has been rewritten to use the standard GDB remote protocol.
5013 * GDB can now step into C++ functions which are called through thunks.
5015 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5017 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5018 layout. It also supports a TextSeg= and DataSeg= response when only
5019 segment base addresses (rather than offsets) are available.
5021 * The /i format now outputs any trailing branch delay slot instructions
5022 immediately following the last instruction within the count specified.
5024 * The GDB remote protocol "T" stop reply packet now supports a
5025 "library" response. Combined with the new "qXfer:libraries:read"
5026 packet, this response allows GDB to debug shared libraries on targets
5027 where the operating system manages the list of loaded libraries (e.g.
5028 Windows and SymbianOS).
5030 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5031 (DLLs) on Windows and Windows CE targets.
5033 * GDB now supports a faster verification that a .debug file matches its binary
5034 according to its build-id signature, if the signature is present.
5040 Enable or disable hardware flow control (RTS/CTS) on the serial port
5041 when debugging using remote targets.
5043 set mem inaccessible-by-default
5044 show mem inaccessible-by-default
5045 If the target supplies a memory map, for instance via the remote
5046 protocol's "qXfer:memory-map:read" packet, setting this variable
5047 prevents GDB from accessing memory outside the memory map. This
5048 is useful for targets with memory mapped registers or which react
5049 badly to accesses of unmapped address space.
5051 set breakpoint auto-hw
5052 show breakpoint auto-hw
5053 If the target supplies a memory map, for instance via the remote
5054 protocol's "qXfer:memory-map:read" packet, setting this variable
5055 lets GDB use hardware breakpoints automatically for memory regions
5056 where it can not use software breakpoints. This covers both the
5057 "break" command and internal breakpoints used for other commands
5058 including "next" and "finish".
5061 catch exception unhandled
5062 Stop the program execution when Ada exceptions are raised.
5065 Stop the program execution when an Ada assertion failed.
5069 Set an alternate system root for target files. This is a more
5070 general version of "set solib-absolute-prefix", which is now
5071 an alias to "set sysroot".
5074 Provide extended SPU facility status information. This set of
5075 commands is available only when debugging the Cell/B.E. SPU
5078 * New native configurations
5080 OpenBSD/sh sh*-*openbsd*
5083 unset tdesc filename
5085 Use the specified local file as an XML target description, and do
5086 not query the target for its built-in description.
5090 OpenBSD/sh sh*-*-openbsd*
5091 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5092 Toshiba Media Processor mep-elf
5094 * New remote packets
5097 Ignore the specified signals; pass them directly to the debugged program
5098 without stopping other threads or reporting them to GDB.
5100 qXfer:features:read:
5101 Read an XML target description from the target, which describes its
5106 Read or write contents of an spufs file on the target system. These
5107 packets are available only on the Cell/B.E. SPU architecture.
5109 qXfer:libraries:read:
5110 Report the loaded shared libraries. Combined with new "T" packet
5111 response, this packet allows GDB to debug shared libraries on
5112 targets where the operating system manages the list of loaded
5113 libraries (e.g. Windows and SymbianOS).
5117 Support for these obsolete configurations has been removed.
5125 i[34567]86-*-lynxos*
5126 i[34567]86-*-netware*
5127 i[34567]86-*-sco3.2v5*
5128 i[34567]86-*-sco3.2v4*
5130 i[34567]86-*-sysv4.2*
5133 i[34567]86-*-unixware2*
5134 i[34567]86-*-unixware*
5143 * Other removed features
5150 Various m68k-only ROM monitors.
5157 Various Renesas ROM monitors and debugging interfaces for SH and
5162 Support for a Macraigor serial interface to on-chip debugging.
5163 GDB does not directly support the newer parallel or USB
5168 A debug information format. The predecessor to DWARF 2 and
5169 DWARF 3, which are still supported.
5171 Support for the HP aCC compiler on HP-UX/PA-RISC
5173 SOM-encapsulated symbolic debugging information, automatic
5174 invocation of pxdb, and the aCC custom C++ ABI. This does not
5175 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5176 with aCC can still be debugged on an assembly level.
5178 MIPS ".pdr" sections
5180 A MIPS-specific format used to describe stack frame layout
5181 in debugging information.
5185 GDB could work with an older version of Guile to debug
5186 the interpreter and Scheme programs running in it.
5188 set mips stack-arg-size
5189 set mips saved-gpreg-size
5191 Use "set mips abi" to control parameter passing for MIPS.
5193 *** Changes in GDB 6.6
5198 Cell Broadband Engine SPU spu-elf
5200 * GDB can now be configured as a cross-debugger targeting native Windows
5201 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5202 running on a Windows system over TCP/IP to debug Windows programs.
5204 * The GDB remote stub, gdbserver, has been updated to support Windows and
5205 Cygwin debugging. Both single-threaded and multi-threaded programs are
5208 * The "set trust-readonly-sections" command works again. This command was
5209 broken in GDB 6.3, 6.4, and 6.5.
5211 * The "load" command now supports writing to flash memory, if the remote
5212 stub provides the required support.
5214 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5215 longer requires symbolic debug information (e.g. DWARF-2).
5220 unset substitute-path
5221 show substitute-path
5222 Manage a list of substitution rules that GDB uses to rewrite the name
5223 of the directories where the sources are located. This can be useful
5224 for instance when the sources were moved to a different location
5225 between compilation and debugging.
5229 Print each CLI command as it is executed. Each command is prefixed with
5230 a number of `+' symbols representing the nesting depth.
5231 The source command now has a `-v' option to enable the same feature.
5235 The ARM Demon monitor support (RDP protocol, "target rdp").
5237 Kernel Object Display, an embedded debugging feature which only worked with
5238 an obsolete version of Cisco IOS.
5240 The 'set download-write-size' and 'show download-write-size' commands.
5242 * New remote packets
5245 Tell a stub about GDB client features, and request remote target features.
5246 The first feature implemented is PacketSize, which allows the target to
5247 specify the size of packets it can handle - to minimize the number of
5248 packets required and improve performance when connected to a remote
5252 Fetch an OS auxilliary vector from the remote stub. This packet is a
5253 more efficient replacement for qPart:auxv:read.
5255 qXfer:memory-map:read:
5256 Fetch a memory map from the remote stub, including information about
5257 RAM, ROM, and flash memory devices.
5262 Erase and program a flash memory device.
5264 * Removed remote packets
5267 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5268 used it, and only gdbserver implemented it.
5270 *** Changes in GDB 6.5
5274 Renesas M32C/M16C m32c-elf
5276 Morpho Technologies ms1 ms1-elf
5280 init-if-undefined Initialize a convenience variable, but
5281 only if it doesn't already have a value.
5283 The following commands are presently only implemented for native GNU/Linux:
5285 checkpoint Save a snapshot of the program state.
5287 restart <n> Return the program state to a
5288 previously saved state.
5290 info checkpoints List currently saved checkpoints.
5292 delete-checkpoint <n> Delete a previously saved checkpoint.
5294 set|show detach-on-fork Tell gdb whether to detach from a newly
5295 forked process, or to keep debugging it.
5297 info forks List forks of the user program that
5298 are available to be debugged.
5300 fork <n> Switch to debugging one of several
5301 forks of the user program that are
5302 available to be debugged.
5304 delete-fork <n> Delete a fork from the list of forks
5305 that are available to be debugged (and
5306 kill the forked process).
5308 detach-fork <n> Delete a fork from the list of forks
5309 that are available to be debugged (and
5310 allow the process to continue).
5314 Morpho Technologies ms2 ms1-elf
5316 * Improved Windows host support
5318 GDB now builds as a cross debugger hosted on i686-mingw32, including
5319 native console support, and remote communications using either
5320 network sockets or serial ports.
5322 * Improved Modula-2 language support
5324 GDB can now print most types in the Modula-2 syntax. This includes:
5325 basic types, set types, record types, enumerated types, range types,
5326 pointer types and ARRAY types. Procedure var parameters are correctly
5327 printed and hexadecimal addresses and character constants are also
5328 written in the Modula-2 syntax. Best results can be obtained by using
5329 GNU Modula-2 together with the -gdwarf-2 command line option.
5333 The ARM rdi-share module.
5335 The Netware NLM debug server.
5337 *** Changes in GDB 6.4
5339 * New native configurations
5341 OpenBSD/arm arm*-*-openbsd*
5342 OpenBSD/mips64 mips64-*-openbsd*
5346 Morpho Technologies ms1 ms1-elf
5348 * New command line options
5350 --batch-silent As for --batch, but totally silent.
5351 --return-child-result The debugger will exist with the same value
5352 the child (debugged) program exited with.
5353 --eval-command COMMAND, -ex COMMAND
5354 Execute a single GDB CLI command. This may be
5355 specified multiple times and in conjunction
5356 with the --command (-x) option.
5358 * Deprecated commands removed
5360 The following commands, that were deprecated in 2000, have been
5364 set|show arm disassembly-flavor set|show arm disassembler
5365 othernames set arm disassembler
5366 set|show remotedebug set|show debug remote
5367 set|show archdebug set|show debug arch
5368 set|show eventdebug set|show debug event
5371 * New BSD user-level threads support
5373 It is now possible to debug programs using the user-level threads
5374 library on OpenBSD and FreeBSD. Currently supported (target)
5377 FreeBSD/amd64 x86_64-*-freebsd*
5378 FreeBSD/i386 i386-*-freebsd*
5379 OpenBSD/i386 i386-*-openbsd*
5381 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5382 are not yet supported.
5384 * New support for Matsushita MN10300 w/sim added
5385 (Work in progress). mn10300-elf.
5387 * REMOVED configurations and files
5389 VxWorks and the XDR protocol *-*-vxworks
5390 Motorola MCORE mcore-*-*
5391 National Semiconductor NS32000 ns32k-*-*
5393 * New "set print array-indexes" command
5395 After turning this setting "on", GDB prints the index of each element
5396 when displaying arrays. The default is "off" to preserve the previous
5399 * VAX floating point support
5401 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5403 * User-defined command support
5405 In addition to using $arg0..$arg9 for argument passing, it is now possible
5406 to use $argc to determine now many arguments have been passed. See the
5407 section on user-defined commands in the user manual for more information.
5409 *** Changes in GDB 6.3:
5411 * New command line option
5413 GDB now accepts -l followed by a number to set the timeout for remote
5416 * GDB works with GCC -feliminate-dwarf2-dups
5418 GDB now supports a more compact representation of DWARF-2 debug
5419 information using DW_FORM_ref_addr references. These are produced
5420 by GCC with the option -feliminate-dwarf2-dups and also by some
5421 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5422 to use -feliminate-dwarf2-dups.
5424 * Internationalization
5426 When supported by the host system, GDB will be built with
5427 internationalization (libintl). The task of marking up the sources is
5428 continued, we're looking forward to our first translation.
5432 Initial support for debugging programs compiled with the GNAT
5433 implementation of the Ada programming language has been integrated
5434 into GDB. In this release, support is limited to expression evaluation.
5436 * New native configurations
5438 GNU/Linux/m32r m32r-*-linux-gnu
5442 GDB's remote protocol now includes support for the 'p' packet. This
5443 packet is used to fetch individual registers from a remote inferior.
5445 * END-OF-LIFE registers[] compatibility module
5447 GDB's internal register infrastructure has been completely rewritten.
5448 The new infrastructure making possible the implementation of key new
5449 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5452 GDB 6.3 will be the last release to include the registers[]
5453 compatibility module that allowed out-of-date configurations to
5454 continue to work. This change directly impacts the following
5464 powerpc bdm protocol
5466 Unless there is activity to revive these configurations, they will be
5467 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5469 * OBSOLETE configurations and files
5471 Configurations that have been declared obsolete in this release have
5472 been commented out. Unless there is activity to revive these
5473 configurations, the next release of GDB will have their sources
5474 permanently REMOVED.
5483 *** Changes in GDB 6.2.1:
5485 * MIPS `break main; run' gave an heuristic-fence-post warning
5487 When attempting to run even a simple program, a warning about
5488 heuristic-fence-post being hit would be reported. This problem has
5491 * MIPS IRIX 'long double' crashed GDB
5493 When examining a long double variable, GDB would get a segmentation
5494 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5495 IRIX long double values).
5499 A bug in the VAX stack code was causing problems with the "next"
5500 command. This problem has been fixed.
5502 *** Changes in GDB 6.2:
5504 * Fix for ``many threads''
5506 On GNU/Linux systems that use the NPTL threads library, a program
5507 rapidly creating and deleting threads would confuse GDB leading to the
5510 ptrace: No such process.
5511 thread_db_get_info: cannot get thread info: generic error
5513 This problem has been fixed.
5515 * "-async" and "-noasync" options removed.
5517 Support for the broken "-noasync" option has been removed (it caused
5520 * New ``start'' command.
5522 This command runs the program until the beginning of the main procedure.
5524 * New BSD Kernel Data Access Library (libkvm) interface
5526 Using ``target kvm'' it is now possible to debug kernel core dumps and
5527 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5528 platforms. Currently supported (native-only) configurations are:
5530 FreeBSD/amd64 x86_64-*-freebsd*
5531 FreeBSD/i386 i?86-*-freebsd*
5532 NetBSD/i386 i?86-*-netbsd*
5533 NetBSD/m68k m68*-*-netbsd*
5534 NetBSD/sparc sparc-*-netbsd*
5535 OpenBSD/amd64 x86_64-*-openbsd*
5536 OpenBSD/i386 i?86-*-openbsd*
5537 OpenBSD/m68k m68*-openbsd*
5538 OpenBSD/sparc sparc-*-openbsd*
5540 * Signal trampoline code overhauled
5542 Many generic problems with GDB's signal handling code have been fixed.
5543 These include: backtraces through non-contiguous stacks; recognition
5544 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5545 call; backtrace through a signal trampoline; step into and out of
5546 signal handlers; and single-stepping in the signal trampoline.
5548 Please note that kernel bugs are a limiting factor here. These
5549 features have been shown to work on an s390 GNU/Linux system that
5550 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5552 * Cygwin support for DWARF 2 added.
5554 * New native configurations
5556 GNU/Linux/hppa hppa*-*-linux*
5557 OpenBSD/hppa hppa*-*-openbsd*
5558 OpenBSD/m68k m68*-*-openbsd*
5559 OpenBSD/m88k m88*-*-openbsd*
5560 OpenBSD/powerpc powerpc-*-openbsd*
5561 NetBSD/vax vax-*-netbsd*
5562 OpenBSD/vax vax-*-openbsd*
5564 * END-OF-LIFE frame compatibility module
5566 GDB's internal frame infrastructure has been completely rewritten.
5567 The new infrastructure making it possible to support key new features
5568 including DWARF 2 Call Frame Information. To aid in the task of
5569 migrating old configurations to this new infrastructure, a
5570 compatibility module, that allowed old configurations to continue to
5571 work, was also included.
5573 GDB 6.2 will be the last release to include this frame compatibility
5574 module. This change directly impacts the following configurations:
5584 Unless there is activity to revive these configurations, they will be
5585 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5587 * REMOVED configurations and files
5589 Sun 3, running SunOS 3 m68*-*-sunos3*
5590 Sun 3, running SunOS 4 m68*-*-sunos4*
5591 Sun 2, running SunOS 3 m68000-*-sunos3*
5592 Sun 2, running SunOS 4 m68000-*-sunos4*
5593 Motorola 680x0 running LynxOS m68*-*-lynxos*
5594 AT&T 3b1/Unix pc m68*-att-*
5595 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5596 decstation mips-dec-* mips-little-*
5597 riscos mips-*-riscos* mips-*-sysv*
5598 sonymips mips-sony-*
5599 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5601 *** Changes in GDB 6.1.1:
5603 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5605 The TUI (Text-mode User Interface) is now built as part of a default
5606 GDB configuration. It is enabled by either selecting the TUI with the
5607 command line option "-i=tui" or by running the separate "gdbtui"
5608 program. For more information on the TUI, see the manual "Debugging
5611 * Pending breakpoint support (also included in GDB 6.1)
5613 Support has been added to allow you to specify breakpoints in shared
5614 libraries that have not yet been loaded. If a breakpoint location
5615 cannot be found, and the "breakpoint pending" option is set to auto,
5616 GDB queries you if you wish to make the breakpoint pending on a future
5617 shared-library load. If and when GDB resolves the breakpoint symbol,
5618 the pending breakpoint is removed as one or more regular breakpoints
5621 Pending breakpoints are very useful for GCJ Java debugging.
5623 * Fixed ISO-C build problems
5625 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5626 non ISO-C code that stopped them being built using a more strict ISO-C
5627 compiler (e.g., IBM's C compiler).
5629 * Fixed build problem on IRIX 5
5631 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5632 wasn't able to compile compile on an IRIX 5 system.
5634 * Added execute permission to gdb/gdbserver/configure
5636 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5637 permission. This bug would cause configure to fail on a number of
5638 systems (Solaris, IRIX). Ref: server/519.
5640 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5642 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5643 has been updated to use constant array sizes.
5645 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5647 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5648 its generated DWARF Call Frame Info. This encoding was causing GDB to
5649 panic, that panic has been fixed. Ref: gdb/1628.
5651 * Fixed a problem when examining parameters in shared library code.
5653 When examining parameters in optimized shared library code generated
5654 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5655 not available''. GDB now correctly displays the variable's value.
5657 *** Changes in GDB 6.1:
5659 * Removed --with-mmalloc
5661 Support for the mmalloc memory manager has been removed, as it
5662 conflicted with the internal gdb byte cache.
5664 * Changes in AMD64 configurations
5666 The AMD64 target now includes the %cs and %ss registers. As a result
5667 the AMD64 remote protocol has changed; this affects the floating-point
5668 and SSE registers. If you rely on those registers for your debugging,
5669 you should upgrade gdbserver on the remote side.
5671 * Revised SPARC target
5673 The SPARC target has been completely revised, incorporating the
5674 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5675 support for LynxOS and SunOS 4 has been dropped. Calling functions
5676 from within GDB on operating systems with a non-executable stack
5677 (Solaris, OpenBSD) now works.
5681 GDB has a new C++ demangler which does a better job on the mangled
5682 names generated by current versions of g++. It also runs faster, so
5683 with this and other changes gdb should now start faster on large C++
5686 * DWARF 2 Location Expressions
5688 GDB support for location expressions has been extended to support function
5689 arguments and frame bases. Older versions of GDB could crash when they
5692 * C++ nested types and namespaces
5694 GDB's support for nested types and namespaces in C++ has been
5695 improved, especially if you use the DWARF 2 debugging format. (This
5696 is the default for recent versions of GCC on most platforms.)
5697 Specifically, if you have a class "Inner" defined within a class or
5698 namespace "Outer", then GDB realizes that the class's name is
5699 "Outer::Inner", not simply "Inner". This should greatly reduce the
5700 frequency of complaints about not finding RTTI symbols. In addition,
5701 if you are stopped at inside of a function defined within a namespace,
5702 GDB modifies its name lookup accordingly.
5704 * New native configurations
5706 NetBSD/amd64 x86_64-*-netbsd*
5707 OpenBSD/amd64 x86_64-*-openbsd*
5708 OpenBSD/alpha alpha*-*-openbsd*
5709 OpenBSD/sparc sparc-*-openbsd*
5710 OpenBSD/sparc64 sparc64-*-openbsd*
5712 * New debugging protocols
5714 M32R with SDI protocol m32r-*-elf*
5716 * "set prompt-escape-char" command deleted.
5718 The command "set prompt-escape-char" has been deleted. This command,
5719 and its very obscure effect on GDB's prompt, was never documented,
5720 tested, nor mentioned in the NEWS file.
5722 * OBSOLETE configurations and files
5724 Configurations that have been declared obsolete in this release have
5725 been commented out. Unless there is activity to revive these
5726 configurations, the next release of GDB will have their sources
5727 permanently REMOVED.
5729 Sun 3, running SunOS 3 m68*-*-sunos3*
5730 Sun 3, running SunOS 4 m68*-*-sunos4*
5731 Sun 2, running SunOS 3 m68000-*-sunos3*
5732 Sun 2, running SunOS 4 m68000-*-sunos4*
5733 Motorola 680x0 running LynxOS m68*-*-lynxos*
5734 AT&T 3b1/Unix pc m68*-att-*
5735 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5736 decstation mips-dec-* mips-little-*
5737 riscos mips-*-riscos* mips-*-sysv*
5738 sonymips mips-sony-*
5739 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5741 * REMOVED configurations and files
5743 SGI Irix-4.x mips-sgi-irix4 or iris4
5744 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5745 Z8000 simulator z8k-zilog-none or z8ksim
5746 Matsushita MN10200 w/simulator mn10200-*-*
5747 H8/500 simulator h8500-hitachi-hms or h8500hms
5748 HP/PA running BSD hppa*-*-bsd*
5749 HP/PA running OSF/1 hppa*-*-osf*
5750 HP/PA Pro target hppa*-*-pro*
5751 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5752 386BSD i[3456]86-*-bsd*
5753 Sequent family i[3456]86-sequent-sysv4*
5754 i[3456]86-sequent-sysv*
5755 i[3456]86-sequent-bsd*
5756 SPARC running LynxOS sparc-*-lynxos*
5757 SPARC running SunOS 4 sparc-*-sunos4*
5758 Tsqware Sparclet sparclet-*-*
5759 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5761 *** Changes in GDB 6.0:
5765 Support for debugging the Objective-C programming language has been
5766 integrated into GDB.
5768 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5770 DWARF 2's Call Frame Information makes available compiler generated
5771 information that more exactly describes the program's run-time stack.
5772 By using this information, GDB is able to provide more robust stack
5775 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5776 have been updated to use a new backtrace mechanism which includes
5777 DWARF 2 CFI support.
5781 GDB's remote protocol has been extended to include support for hosted
5782 file I/O (where the remote target uses GDB's file system). See GDB's
5783 remote protocol documentation for details.
5785 * All targets using the new architecture framework.
5787 All of GDB's targets have been updated to use the new internal
5788 architecture framework. The way is now open for future GDB releases
5789 to include cross-architecture native debugging support (i386 on amd64,
5792 * GNU/Linux's Thread Local Storage (TLS)
5794 GDB now includes support for for the GNU/Linux implementation of
5795 per-thread variables.
5797 * GNU/Linux's Native POSIX Thread Library (NPTL)
5799 GDB's thread code has been updated to work with either the new
5800 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5802 * Separate debug info.
5804 GDB, in conjunction with BINUTILS, now supports a mechanism for
5805 automatically loading debug information from a separate file. Instead
5806 of shipping full debug and non-debug versions of system libraries,
5807 system integrators can now instead ship just the stripped libraries
5808 and optional debug files.
5810 * DWARF 2 Location Expressions
5812 DWARF 2 Location Expressions allow the compiler to more completely
5813 describe the location of variables (even in optimized code) to the
5816 GDB now includes preliminary support for location expressions (support
5817 for DW_OP_piece is still missing).
5821 A number of long standing bugs that caused GDB to die while starting a
5822 Java application have been fixed. GDB's Java support is now
5823 considered "useable".
5825 * GNU/Linux support for fork, vfork, and exec.
5827 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5828 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5831 * GDB supports logging output to a file
5833 There are two new commands, "set logging" and "show logging", which can be
5834 used to capture GDB's output to a file.
5836 * The meaning of "detach" has changed for gdbserver
5838 The "detach" command will now resume the application, as documented. To
5839 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5842 * d10v, m68hc11 `regs' command deprecated
5844 The `info registers' command has been updated so that it displays the
5845 registers using a format identical to the old `regs' command.
5849 A new command, "maint set profile on/off", has been added. This command can
5850 be used to enable or disable profiling while running GDB, to profile a
5851 session or a set of commands. In addition there is a new configure switch,
5852 "--enable-profiling", which will cause GDB to be compiled with profiling
5853 data, for more informative profiling results.
5855 * Default MI syntax changed to "mi2".
5857 The default MI (machine interface) syntax, enabled by the command line
5858 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5859 "mi1", can be enabled by specifying the option "-i=mi1".
5861 Support for the original "mi0" syntax (included in GDB 5.0) has been
5864 Fix for gdb/192: removed extraneous space when displaying frame level.
5865 Fix for gdb/672: update changelist is now output in mi list format.
5866 Fix for gdb/702: a -var-assign that updates the value now shows up
5867 in a subsequent -var-update.
5869 * New native configurations.
5871 FreeBSD/amd64 x86_64-*-freebsd*
5873 * Multi-arched targets.
5875 HP/PA HPUX11 hppa*-*-hpux*
5876 Renesas M32R/D w/simulator m32r-*-elf*
5878 * OBSOLETE configurations and files
5880 Configurations that have been declared obsolete in this release have
5881 been commented out. Unless there is activity to revive these
5882 configurations, the next release of GDB will have their sources
5883 permanently REMOVED.
5885 Z8000 simulator z8k-zilog-none or z8ksim
5886 Matsushita MN10200 w/simulator mn10200-*-*
5887 H8/500 simulator h8500-hitachi-hms or h8500hms
5888 HP/PA running BSD hppa*-*-bsd*
5889 HP/PA running OSF/1 hppa*-*-osf*
5890 HP/PA Pro target hppa*-*-pro*
5891 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5892 Sequent family i[3456]86-sequent-sysv4*
5893 i[3456]86-sequent-sysv*
5894 i[3456]86-sequent-bsd*
5895 Tsqware Sparclet sparclet-*-*
5896 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5898 * REMOVED configurations and files
5901 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5902 IBM AIX PS/2 i[3456]86-*-aix
5903 i386 running Mach 3.0 i[3456]86-*-mach3*
5904 i386 running Mach i[3456]86-*-mach*
5905 i386 running OSF/1 i[3456]86-*osf1mk*
5906 HP/Apollo 68k Family m68*-apollo*-sysv*,
5908 m68*-hp-bsd*, m68*-hp-hpux*
5909 Argonaut Risc Chip (ARC) arc-*-*
5910 Mitsubishi D30V d30v-*-*
5911 Fujitsu FR30 fr30-*-elf*
5912 OS/9000 i[34]86-*-os9k
5913 I960 with MON960 i960-*-coff
5915 * MIPS $fp behavior changed
5917 The convenience variable $fp, for the MIPS, now consistently returns
5918 the address of the current frame's base. Previously, depending on the
5919 context, $fp could refer to either $sp or the current frame's base
5920 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5921 The GNU Source-Level Debugger''.
5923 *** Changes in GDB 5.3:
5925 * GNU/Linux shared library multi-threaded performance improved.
5927 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5928 `/proc', in preference to `ptrace' for memory reads. This may result
5929 in an improvement in the start-up time of multi-threaded, shared
5930 library applications when run under GDB. One GDB user writes: ``loads
5931 shared libs like mad''.
5933 * ``gdbserver'' now supports multi-threaded applications on some targets
5935 Support for debugging multi-threaded applications which use
5936 the GNU/Linux LinuxThreads package has been added for
5937 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5938 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5940 * GDB now supports C/C++ preprocessor macros.
5942 GDB now expands preprocessor macro invocations in C/C++ expressions,
5943 and provides various commands for showing macro definitions and how
5946 The new command `macro expand EXPRESSION' expands any macro
5947 invocations in expression, and shows the result.
5949 The new command `show macro MACRO-NAME' shows the definition of the
5950 macro named MACRO-NAME, and where it was defined.
5952 Most compilers don't include information about macros in the debugging
5953 information by default. In GCC 3.1, for example, you need to compile
5954 your program with the options `-gdwarf-2 -g3'. If the macro
5955 information is present in the executable, GDB will read it.
5957 * Multi-arched targets.
5959 DEC Alpha (partial) alpha*-*-*
5960 DEC VAX (partial) vax-*-*
5962 National Semiconductor NS32000 (partial) ns32k-*-*
5963 Motorola 68000 (partial) m68k-*-*
5964 Motorola MCORE mcore-*-*
5968 Fujitsu FRV architecture added by Red Hat frv*-*-*
5971 * New native configurations
5973 Alpha NetBSD alpha*-*-netbsd*
5974 SH NetBSD sh*-*-netbsdelf*
5975 MIPS NetBSD mips*-*-netbsd*
5976 UltraSPARC NetBSD sparc64-*-netbsd*
5978 * OBSOLETE configurations and files
5980 Configurations that have been declared obsolete in this release have
5981 been commented out. Unless there is activity to revive these
5982 configurations, the next release of GDB will have their sources
5983 permanently REMOVED.
5985 Mitsubishi D30V d30v-*-*
5986 OS/9000 i[34]86-*-os9k
5987 IBM AIX PS/2 i[3456]86-*-aix
5988 Fujitsu FR30 fr30-*-elf*
5989 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5990 Argonaut Risc Chip (ARC) arc-*-*
5991 i386 running Mach 3.0 i[3456]86-*-mach3*
5992 i386 running Mach i[3456]86-*-mach*
5993 i386 running OSF/1 i[3456]86-*osf1mk*
5994 HP/Apollo 68k Family m68*-apollo*-sysv*,
5996 m68*-hp-bsd*, m68*-hp-hpux*
5997 I960 with MON960 i960-*-coff
5999 * OBSOLETE languages
6001 CHILL, a Pascal like language used by telecommunications companies.
6003 * REMOVED configurations and files
6005 AMD 29k family via UDI a29k-amd-udi, udi29k
6006 A29K VxWorks a29k-*-vxworks
6007 AMD 29000 embedded, using EBMON a29k-none-none
6008 AMD 29000 embedded with COFF a29k-none-coff
6009 AMD 29000 embedded with a.out a29k-none-aout
6011 testsuite/gdb.hp/gdb.threads-hp/ directory
6013 * New command "set max-user-call-depth <nnn>"
6015 This command allows the user to limit the call depth of user-defined
6016 commands. The default is 1024.
6018 * Changes in FreeBSD/i386 native debugging.
6020 Support for the "generate-core-file" has been added.
6022 * New commands "dump", "append", and "restore".
6024 These commands allow data to be copied from target memory
6025 to a bfd-format or binary file (dump and append), and back
6026 from a file into memory (restore).
6028 * Improved "next/step" support on multi-processor Alpha Tru64.
6030 The previous single-step mechanism could cause unpredictable problems,
6031 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6032 of a software single-step mechanism prevents this.
6034 *** Changes in GDB 5.2.1:
6042 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6043 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6044 Fix, by Joel Brobecker imported from mainline.
6046 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6047 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6048 Fix, by Fred Fish, imported from mainline.
6050 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6051 Surprisingly enough, it works now.
6052 By Michal Ludvig, imported from mainline.
6054 i386 hardware watchpoint support:
6055 avoid misses on second run for some targets.
6056 By Pierre Muller, imported from mainline.
6058 *** Changes in GDB 5.2:
6060 * New command "set trust-readonly-sections on[off]".
6062 This command is a hint that tells gdb that read-only sections
6063 really are read-only (ie. that their contents will not change).
6064 In this mode, gdb will go to the object file rather than the
6065 target to read memory from read-only sections (such as ".text").
6066 This can be a significant performance improvement on some
6067 (notably embedded) targets.
6069 * New command "generate-core-file" (or "gcore").
6071 This new gdb command allows the user to drop a core file of the child
6072 process state at any time. So far it's been implemented only for
6073 GNU/Linux and Solaris, but should be relatively easily ported to other
6074 hosts. Argument is core file name (defaults to core.<pid>).
6076 * New command line option
6078 GDB now accepts --pid or -p followed by a process id.
6080 * Change in command line behavior -- corefiles vs. process ids.
6082 There is a subtle behavior in the way in which GDB handles
6083 command line arguments. The first non-flag argument is always
6084 a program to debug, but the second non-flag argument may either
6085 be a corefile or a process id. Previously, GDB would attempt to
6086 open the second argument as a corefile, and if that failed, would
6087 issue a superfluous error message and then attempt to attach it as
6088 a process. Now, if the second argument begins with a non-digit,
6089 it will be treated as a corefile. If it begins with a digit,
6090 GDB will attempt to attach it as a process, and if no such process
6091 is found, will then attempt to open it as a corefile.
6093 * Changes in ARM configurations.
6095 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6096 configuration is fully multi-arch.
6098 * New native configurations
6100 ARM NetBSD arm*-*-netbsd*
6101 x86 OpenBSD i[3456]86-*-openbsd*
6102 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6103 Sparc64 running FreeBSD sparc64-*-freebsd*
6107 Sanyo XStormy16 xstormy16-elf
6109 * OBSOLETE configurations and files
6111 Configurations that have been declared obsolete in this release have
6112 been commented out. Unless there is activity to revive these
6113 configurations, the next release of GDB will have their sources
6114 permanently REMOVED.
6116 AMD 29k family via UDI a29k-amd-udi, udi29k
6117 A29K VxWorks a29k-*-vxworks
6118 AMD 29000 embedded, using EBMON a29k-none-none
6119 AMD 29000 embedded with COFF a29k-none-coff
6120 AMD 29000 embedded with a.out a29k-none-aout
6122 testsuite/gdb.hp/gdb.threads-hp/ directory
6124 * REMOVED configurations and files
6126 TI TMS320C80 tic80-*-*
6128 PowerPC Solaris powerpcle-*-solaris*
6129 PowerPC Windows NT powerpcle-*-cygwin32
6130 PowerPC Netware powerpc-*-netware*
6131 Harris/CXUX m88k m88*-harris-cxux*
6132 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6133 ns32k-utek-sysv* ns32k-utek-*
6134 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6135 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6136 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6137 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6138 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6140 * Changes to command line processing
6142 The new `--args' feature can be used to specify command-line arguments
6143 for the inferior from gdb's command line.
6145 * Changes to key bindings
6147 There is a new `operate-and-get-next' function bound to `C-o'.
6149 *** Changes in GDB 5.1.1
6151 Fix compile problem on DJGPP.
6153 Fix a problem with floating-point registers on the i386 being
6156 Fix to stop GDB crashing on .debug_str debug info.
6158 Numerous documentation fixes.
6160 Numerous testsuite fixes.
6162 *** Changes in GDB 5.1:
6164 * New native configurations
6166 Alpha FreeBSD alpha*-*-freebsd*
6167 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6168 MIPS GNU/Linux mips*-*-linux*
6169 MIPS SGI Irix 6.x mips*-sgi-irix6*
6170 ia64 AIX ia64-*-aix*
6171 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6175 Motorola 68HC11 and 68HC12 m68hc11-elf
6177 UltraSparc running GNU/Linux sparc64-*-linux*
6179 * OBSOLETE configurations and files
6181 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6182 Harris/CXUX m88k m88*-harris-cxux*
6183 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6184 ns32k-utek-sysv* ns32k-utek-*
6185 TI TMS320C80 tic80-*-*
6187 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6188 PowerPC Solaris powerpcle-*-solaris*
6189 PowerPC Windows NT powerpcle-*-cygwin32
6190 PowerPC Netware powerpc-*-netware*
6191 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6192 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6193 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6194 Apple Macintosh (MPW) host N/A
6196 stuff.c (Program to stuff files into a specially prepared space in kdb)
6197 kdb-start.c (Main loop for the standalone kernel debugger)
6199 Configurations that have been declared obsolete in this release have
6200 been commented out. Unless there is activity to revive these
6201 configurations, the next release of GDB will have their sources
6202 permanently REMOVED.
6204 * REMOVED configurations and files
6206 Altos 3068 m68*-altos-*
6207 Convex c1-*-*, c2-*-*
6209 ARM RISCix arm-*-* (as host)
6213 * GDB has been converted to ISO C.
6215 GDB's source code has been converted to ISO C. In particular, the
6216 sources are fully protoized, and rely on standard headers being
6221 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6223 * The MI enabled by default.
6225 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6226 revised and enabled by default. Packages which use GDB as a debugging
6227 engine behind a UI or another front end are encouraged to switch to
6228 using the GDB/MI interface, instead of the old annotations interface
6229 which is now deprecated.
6231 * Support for debugging Pascal programs.
6233 GDB now includes support for debugging Pascal programs. The following
6234 main features are supported:
6236 - Pascal-specific data types such as sets;
6238 - automatic recognition of Pascal sources based on file-name
6241 - Pascal-style display of data types, variables, and functions;
6243 - a Pascal expression parser.
6245 However, some important features are not yet supported.
6247 - Pascal string operations are not supported at all;
6249 - there are some problems with boolean types;
6251 - Pascal type hexadecimal constants are not supported
6252 because they conflict with the internal variables format;
6254 - support for Pascal objects and classes is not full yet;
6256 - unlike Pascal, GDB is case-sensitive for symbol names.
6258 * Changes in completion.
6260 Commands such as `shell', `run' and `set args', which pass arguments
6261 to inferior programs, now complete on file names, similar to what
6262 users expect at the shell prompt.
6264 Commands which accept locations, such as `disassemble', `print',
6265 `breakpoint', `until', etc. now complete on filenames as well as
6266 program symbols. Thus, if you type "break foob TAB", and the source
6267 files linked into the programs include `foobar.c', that file name will
6268 be one of the candidates for completion. However, file names are not
6269 considered for completion after you typed a colon that delimits a file
6270 name from a name of a function in that file, as in "break foo.c:bar".
6272 `set demangle-style' completes on available demangling styles.
6274 * New platform-independent commands:
6276 It is now possible to define a post-hook for a command as well as a
6277 hook that runs before the command. For more details, see the
6278 documentation of `hookpost' in the GDB manual.
6280 * Changes in GNU/Linux native debugging.
6282 Support for debugging multi-threaded programs has been completely
6283 revised for all platforms except m68k and sparc. You can now debug as
6284 many threads as your system allows you to have.
6286 Attach/detach is supported for multi-threaded programs.
6288 Support for SSE registers was added for x86. This doesn't work for
6289 multi-threaded programs though.
6291 * Changes in MIPS configurations.
6293 Multi-arch support is enabled for all MIPS configurations.
6295 GDB can now be built as native debugger on SGI Irix 6.x systems for
6296 debugging n32 executables. (Debugging 64-bit executables is not yet
6299 * Unified support for hardware watchpoints in all x86 configurations.
6301 Most (if not all) native x86 configurations support hardware-assisted
6302 breakpoints and watchpoints in a unified manner. This support
6303 implements debug register sharing between watchpoints, which allows to
6304 put a virtually infinite number of watchpoints on the same address,
6305 and also supports watching regions up to 16 bytes with several debug
6308 The new maintenance command `maintenance show-debug-regs' toggles
6309 debugging print-outs in functions that insert, remove, and test
6310 watchpoints and hardware breakpoints.
6312 * Changes in the DJGPP native configuration.
6314 New command ``info dos sysinfo'' displays assorted information about
6315 the CPU, OS, memory, and DPMI server.
6317 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6318 display information about segment descriptors stored in GDT, LDT, and
6321 New commands ``info dos pde'' and ``info dos pte'' display entries
6322 from Page Directory and Page Tables (for now works with CWSDPMI only).
6323 New command ``info dos address-pte'' displays the Page Table entry for
6324 a given linear address.
6326 GDB can now pass command lines longer than 126 characters to the
6327 program being debugged (requires an update to the libdbg.a library
6328 which is part of the DJGPP development kit).
6330 DWARF2 debug info is now supported.
6332 It is now possible to `step' and `next' through calls to `longjmp'.
6334 * Changes in documentation.
6336 All GDB documentation was converted to GFDL, the GNU Free
6337 Documentation License.
6339 Tracepoints-related commands are now fully documented in the GDB
6342 TUI, the Text-mode User Interface, is now documented in the manual.
6344 Tracepoints-related commands are now fully documented in the GDB
6347 The "GDB Internals" manual now has an index. It also includes
6348 documentation of `ui_out' functions, GDB coding standards, x86
6349 hardware watchpoints, and memory region attributes.
6351 * GDB's version number moved to ``version.in''
6353 The Makefile variable VERSION has been replaced by the file
6354 ``version.in''. People creating GDB distributions should update the
6355 contents of this file.
6359 GUD support is now a standard part of the EMACS distribution.
6361 *** Changes in GDB 5.0:
6363 * Improved support for debugging FP programs on x86 targets
6365 Unified and much-improved support for debugging floating-point
6366 programs on all x86 targets. In particular, ``info float'' now
6367 displays the FP registers in the same format on all x86 targets, with
6368 greater level of detail.
6370 * Improvements and bugfixes in hardware-assisted watchpoints
6372 It is now possible to watch array elements, struct members, and
6373 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6374 on x86 targets no longer erroneously trigger when the address is
6377 * Improvements in the native DJGPP version of GDB
6379 The distribution now includes all the scripts and auxiliary files
6380 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6381 machines ``out of the box''.
6383 The DJGPP version can now debug programs that use signals. It is
6384 possible to catch signals that happened in the debuggee, deliver
6385 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6386 would kill the program being debugged.) Programs that hook hardware
6387 interrupts (keyboard, timer, etc.) can also be debugged.
6389 It is now possible to debug DJGPP programs that redirect their
6390 standard handles or switch them to raw (as opposed to cooked) mode, or
6391 even close them. The command ``run < foo > bar'' works as expected,
6392 and ``info terminal'' reports useful information about the debuggee's
6393 terminal, including raw/cooked mode, redirection, etc.
6395 The DJGPP version now uses termios functions for console I/O, which
6396 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6399 DOS-style file names with drive letters are now fully supported by
6402 It is now possible to debug DJGPP programs that switch their working
6403 directory. It is also possible to rerun the debuggee any number of
6404 times without restarting GDB; thus, you can use the same setup,
6405 breakpoints, etc. for many debugging sessions.
6407 * New native configurations
6409 ARM GNU/Linux arm*-*-linux*
6410 PowerPC GNU/Linux powerpc-*-linux*
6414 Motorola MCore mcore-*-*
6415 x86 VxWorks i[3456]86-*-vxworks*
6416 PowerPC VxWorks powerpc-*-vxworks*
6417 TI TMS320C80 tic80-*-*
6419 * OBSOLETE configurations
6421 Altos 3068 m68*-altos-*
6422 Convex c1-*-*, c2-*-*
6424 ARM RISCix arm-*-* (as host)
6427 Configurations that have been declared obsolete will be commented out,
6428 but the code will be left in place. If there is no activity to revive
6429 these configurations before the next release of GDB, the sources will
6430 be permanently REMOVED.
6432 * Gould support removed
6434 Support for the Gould PowerNode and NP1 has been removed.
6436 * New features for SVR4
6438 On SVR4 native platforms (such as Solaris), if you attach to a process
6439 without first loading a symbol file, GDB will now attempt to locate and
6440 load symbols from the running process's executable file.
6442 * Many C++ enhancements
6444 C++ support has been greatly improved. Overload resolution now works properly
6445 in almost all cases. RTTI support is on the way.
6447 * Remote targets can connect to a sub-program
6449 A popen(3) style serial-device has been added. This device starts a
6450 sub-process (such as a stand-alone simulator) and then communicates
6451 with that. The sub-program to run is specified using the syntax
6452 ``|<program> <args>'' vis:
6454 (gdb) set remotedebug 1
6455 (gdb) target extended-remote |mn10300-elf-sim program-args
6457 * MIPS 64 remote protocol
6459 A long standing bug in the mips64 remote protocol where by GDB
6460 expected certain 32 bit registers (ex SR) to be transfered as 32
6461 instead of 64 bits has been fixed.
6463 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6464 added to provide backward compatibility with older versions of GDB.
6466 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6468 The command ``set remotebinarydownload'' command has been replaced by
6469 ``set remote X-packet''. Other commands in ``set remote'' family
6470 include ``set remote P-packet''.
6472 * Breakpoint commands accept ranges.
6474 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6475 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6476 ``tracepoint passcount'' also accepts a range of tracepoints.
6478 * ``apropos'' command added.
6480 The ``apropos'' command searches through command names and
6481 documentation strings, printing out matches, making it much easier to
6482 try to find a command that does what you are looking for.
6486 A new machine oriented interface (MI) has been added to GDB. This
6487 interface is designed for debug environments running GDB as a separate
6488 process. This is part of the long term libGDB project. See the
6489 "GDB/MI" chapter of the GDB manual for further information. It can be
6490 enabled by configuring with:
6492 .../configure --enable-gdbmi
6494 *** Changes in GDB-4.18:
6496 * New native configurations
6498 HP-UX 10.20 hppa*-*-hpux10.20
6499 HP-UX 11.x hppa*-*-hpux11.0*
6500 M68K GNU/Linux m68*-*-linux*
6504 Fujitsu FR30 fr30-*-elf*
6505 Intel StrongARM strongarm-*-*
6506 Mitsubishi D30V d30v-*-*
6508 * OBSOLETE configurations
6510 Gould PowerNode, NP1 np1-*-*, pn-*-*
6512 Configurations that have been declared obsolete will be commented out,
6513 but the code will be left in place. If there is no activity to revive
6514 these configurations before the next release of GDB, the sources will
6515 be permanently REMOVED.
6519 As a compatibility experiment, GDB's source files buildsym.h and
6520 buildsym.c have been converted to pure standard C, no longer
6521 containing any K&R compatibility code. We believe that all systems in
6522 use today either come with a standard C compiler, or have a GCC port
6523 available. If this is not true, please report the affected
6524 configuration to bug-gdb@gnu.org immediately. See the README file for
6525 information about getting a standard C compiler if you don't have one
6530 GDB now uses readline 2.2.
6532 * set extension-language
6534 You can now control the mapping between filename extensions and source
6535 languages by using the `set extension-language' command. For instance,
6536 you can ask GDB to treat .c files as C++ by saying
6537 set extension-language .c c++
6538 The command `info extensions' lists all of the recognized extensions
6539 and their associated languages.
6541 * Setting processor type for PowerPC and RS/6000
6543 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6544 you can use the `set processor' command to specify what variant of the
6545 PowerPC family you are debugging. The command
6549 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6550 following PowerPC and RS6000 variants:
6552 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6553 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6555 403GC IBM PowerPC 403GC
6556 505 Motorola PowerPC 505
6557 860 Motorola PowerPC 860 or 850
6558 601 Motorola PowerPC 601
6559 602 Motorola PowerPC 602
6560 603 Motorola/IBM PowerPC 603 or 603e
6561 604 Motorola PowerPC 604 or 604e
6562 750 Motorola/IBM PowerPC 750 or 750
6564 At the moment, this command just tells GDB what to name the
6565 special-purpose processor registers. Since almost all the affected
6566 registers are inaccessible to user-level programs, this command is
6567 only useful for remote debugging in its present form.
6571 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6572 more extensive support for HP-UX. Added features include shared
6573 library support, kernel threads and hardware watchpoints for 11.00,
6574 support for HP's ANSI C and C++ compilers, and a compatibility mode
6575 for xdb and dbx commands.
6579 HP's donation includes the new concept of catchpoints, which is a
6580 generalization of the old catch command. On HP-UX, it is now possible
6581 to catch exec, fork, and vfork, as well as library loading.
6583 This means that the existing catch command has changed; its first
6584 argument now specifies the type of catch to be set up. See the
6585 output of "help catch" for a list of catchpoint types.
6587 * Debugging across forks
6589 On HP-UX, you can choose which process to debug when a fork() happens
6594 HP has donated a curses-based terminal user interface (TUI). To get
6595 it, build with --enable-tui. Although this can be enabled for any
6596 configuration, at present it only works for native HP debugging.
6598 * GDB remote protocol additions
6600 A new protocol packet 'X' that writes binary data is now available.
6601 Default behavior is to try 'X', then drop back to 'M' if the stub
6602 fails to respond. The settable variable `remotebinarydownload'
6603 allows explicit control over the use of 'X'.
6605 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6606 full 64-bit address. The command
6608 set remoteaddresssize 32
6610 can be used to revert to the old behaviour. For existing remote stubs
6611 the change should not be noticed, as the additional address information
6614 In order to assist in debugging stubs, you may use the maintenance
6615 command `packet' to send any text string to the stub. For instance,
6617 maint packet heythere
6619 sends the packet "$heythere#<checksum>". Note that it is very easy to
6620 disrupt a debugging session by sending the wrong packet at the wrong
6623 The compare-sections command allows you to compare section data on the
6624 target to what is in the executable file without uploading or
6625 downloading, by comparing CRC checksums.
6627 * Tracing can collect general expressions
6629 You may now collect general expressions at tracepoints. This requires
6630 further additions to the target-side stub; see tracepoint.c and
6631 doc/agentexpr.texi for further details.
6633 * mask-address variable for Mips
6635 For Mips targets, you may control the zeroing of the upper 32 bits of
6636 a 64-bit address by entering `set mask-address on'. This is mainly
6637 of interest to users of embedded R4xxx and R5xxx processors.
6639 * Higher serial baud rates
6641 GDB's serial code now allows you to specify baud rates 57600, 115200,
6642 230400, and 460800 baud. (Note that your host system may not be able
6643 to achieve all of these rates.)
6647 The i960 configuration now includes an initial implementation of a
6648 builtin simulator, contributed by Jim Wilson.
6651 *** Changes in GDB-4.17:
6653 * New native configurations
6655 Alpha GNU/Linux alpha*-*-linux*
6656 Unixware 2.x i[3456]86-unixware2*
6657 Irix 6.x mips*-sgi-irix6*
6658 PowerPC GNU/Linux powerpc-*-linux*
6659 PowerPC Solaris powerpcle-*-solaris*
6660 Sparc GNU/Linux sparc-*-linux*
6661 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6665 Argonaut Risc Chip (ARC) arc-*-*
6666 Hitachi H8/300S h8300*-*-*
6667 Matsushita MN10200 w/simulator mn10200-*-*
6668 Matsushita MN10300 w/simulator mn10300-*-*
6669 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6670 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6671 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6672 Mitsubishi D10V w/simulator d10v-*-*
6673 Mitsubishi M32R/D w/simulator m32r-*-elf*
6674 Tsqware Sparclet sparclet-*-*
6675 NEC V850 w/simulator v850-*-*
6677 * New debugging protocols
6679 ARM with RDI protocol arm*-*-*
6680 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6681 DDB and LSI variants of PMON protocol mips*-*-*
6682 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6683 PowerPC with SDS protocol powerpc{,le}-*-eabi
6684 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6688 All configurations can now understand and use the DWARF 2 debugging
6689 format. The choice is automatic, if the symbol file contains DWARF 2
6694 GDB now includes basic Java language support. This support is
6695 only useful with Java compilers that produce native machine code.
6697 * solib-absolute-prefix and solib-search-path
6699 For SunOS and SVR4 shared libraries, you may now set the prefix for
6700 loading absolute shared library symbol files, and the search path for
6701 locating non-absolute shared library symbol files.
6703 * Live range splitting
6705 GDB can now effectively debug code for which GCC has performed live
6706 range splitting as part of its optimization. See gdb/doc/LRS for
6707 more details on the expected format of the stabs information.
6711 GDB's support for the GNU Hurd, including thread debugging, has been
6712 updated to work with current versions of the Hurd.
6716 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6717 instruction set. ARM GDB automatically detects when Thumb
6718 instructions are in use, and adjusts disassembly and backtracing
6723 GDB's MIPS target configurations now handle the MIP16 16-bit
6728 GDB now includes support for overlays; if an executable has been
6729 linked such that multiple sections are based at the same address, GDB
6730 will decide which section to use for symbolic info. You can choose to
6731 control the decision manually, using overlay commands, or implement
6732 additional target-side support and use "overlay load-target" to bring
6733 in the overlay mapping. Do "help overlay" for more detail.
6737 The command "info symbol <address>" displays information about
6738 the symbol at the specified address.
6742 The standard remote protocol now includes an extension that allows
6743 asynchronous collection and display of trace data. This requires
6744 extensive support in the target-side debugging stub. Tracing mode
6745 includes a new interaction mode in GDB and new commands: see the
6746 file tracepoint.c for more details.
6750 Configurations for embedded MIPS now include a simulator contributed
6751 by Cygnus Solutions. The simulator supports the instruction sets
6752 of most MIPS variants.
6756 Sparc configurations may now include the ERC32 simulator contributed
6757 by the European Space Agency. The simulator is not built into
6758 Sparc targets by default; configure with --enable-sim to include it.
6762 For target configurations that may include multiple variants of a
6763 basic architecture (such as MIPS and SH), you may now set the
6764 architecture explicitly. "set arch" sets, "info arch" lists
6765 the possible architectures.
6767 *** Changes in GDB-4.16:
6769 * New native configurations
6771 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6772 M68K NetBSD m68k-*-netbsd*
6773 PowerPC AIX 4.x powerpc-*-aix*
6774 PowerPC MacOS powerpc-*-macos*
6775 PowerPC Windows NT powerpcle-*-cygwin32
6776 RS/6000 AIX 4.x rs6000-*-aix4*
6780 ARM with RDP protocol arm-*-*
6781 I960 with MON960 i960-*-coff
6782 MIPS VxWorks mips*-*-vxworks*
6783 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6784 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6786 Matra Sparclet sparclet-*-*
6790 The powerpc-eabi configuration now includes the PSIM simulator,
6791 contributed by Andrew Cagney, with assistance from Mike Meissner.
6792 PSIM is a very elaborate model of the PowerPC, including not only
6793 basic instruction set execution, but also details of execution unit
6794 performance and I/O hardware. See sim/ppc/README for more details.
6798 GDB now works with Solaris 2.5.
6800 * Windows 95/NT native
6802 GDB will now work as a native debugger on Windows 95 and Windows NT.
6803 To build it from source, you must use the "gnu-win32" environment,
6804 which uses a DLL to emulate enough of Unix to run the GNU tools.
6805 Further information, binaries, and sources are available at
6806 ftp.cygnus.com, under pub/gnu-win32.
6808 * dont-repeat command
6810 If a user-defined command includes the command `dont-repeat', then the
6811 command will not be repeated if the user just types return. This is
6812 useful if the command is time-consuming to run, so that accidental
6813 extra keystrokes don't run the same command many times.
6815 * Send break instead of ^C
6817 The standard remote protocol now includes an option to send a break
6818 rather than a ^C to the target in order to interrupt it. By default,
6819 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6821 * Remote protocol timeout
6823 The standard remote protocol includes a new variable `remotetimeout'
6824 that allows you to set the number of seconds before GDB gives up trying
6825 to read from the target. The default value is 2.
6827 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6829 By default GDB will automatically keep track of objects as they are
6830 loaded and unloaded by the dynamic linker. By using the command `set
6831 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6832 when shared library events occur, thus allowing you to set breakpoints
6833 in shared libraries which are explicitly loaded by the inferior.
6835 Note this feature does not work on hpux8. On hpux9 you must link
6836 /usr/lib/end.o into your program. This feature should work
6837 automatically on hpux10.
6839 * Irix 5.x hardware watchpoint support
6841 Irix 5 configurations now support the use of hardware watchpoints.
6843 * Mips protocol "SYN garbage limit"
6845 When debugging a Mips target using the `target mips' protocol, you
6846 may set the number of characters that GDB will ignore by setting
6847 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6848 every character. The default value is 1050.
6850 * Recording and replaying remote debug sessions
6852 If you set `remotelogfile' to the name of a file, gdb will write to it
6853 a recording of a remote debug session. This recording may then be
6854 replayed back to gdb using "gdbreplay". See gdbserver/README for
6855 details. This is useful when you have a problem with GDB while doing
6856 remote debugging; you can make a recording of the session and send it
6857 to someone else, who can then recreate the problem.
6859 * Speedups for remote debugging
6861 GDB includes speedups for downloading and stepping MIPS systems using
6862 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6863 and more efficient S-record downloading.
6865 * Memory use reductions and statistics collection
6867 GDB now uses less memory and reports statistics about memory usage.
6868 Try the `maint print statistics' command, for example.
6870 *** Changes in GDB-4.15:
6872 * Psymtabs for XCOFF
6874 The symbol reader for AIX GDB now uses partial symbol tables. This
6875 can greatly improve startup time, especially for large executables.
6877 * Remote targets use caching
6879 Remote targets now use a data cache to speed up communication with the
6880 remote side. The data cache could lead to incorrect results because
6881 it doesn't know about volatile variables, thus making it impossible to
6882 debug targets which use memory mapped I/O devices. `set remotecache
6883 off' turns the data cache off.
6885 * Remote targets may have threads
6887 The standard remote protocol now includes support for multiple threads
6888 in the target system, using new protocol commands 'H' and 'T'. See
6889 gdb/remote.c for details.
6893 If GDB is configured with `--enable-netrom', then it will include
6894 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6895 acts as though it is a bank of ROM on the target board, but you can
6896 write into it over the network. GDB's support consists only of
6897 support for fast loading into the emulated ROM; to debug, you must use
6898 another protocol, such as standard remote protocol. The usual
6899 sequence is something like
6901 target nrom <netrom-hostname>
6903 target remote <netrom-hostname>:1235
6907 GDB now includes support for the Apple Macintosh, as a host only. It
6908 may be run as either an MPW tool or as a standalone application, and
6909 it can debug through the serial port. All the usual GDB commands are
6910 available, but to the target command, you must supply "serial" as the
6911 device type instead of "/dev/ttyXX". See mpw-README in the main
6912 directory for more information on how to build. The MPW configuration
6913 scripts */mpw-config.in support only a few targets, and only the
6914 mips-idt-ecoff target has been tested.
6918 GDB configuration now uses autoconf. This is not user-visible,
6919 but does simplify configuration and building.
6923 GDB now supports hpux10.
6925 *** Changes in GDB-4.14:
6927 * New native configurations
6929 x86 FreeBSD i[345]86-*-freebsd
6930 x86 NetBSD i[345]86-*-netbsd
6931 NS32k NetBSD ns32k-*-netbsd
6932 Sparc NetBSD sparc-*-netbsd
6936 A29K VxWorks a29k-*-vxworks
6937 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6938 CPU32 EST-300 emulator m68*-*-est*
6939 PowerPC ELF powerpc-*-elf
6942 * Alpha OSF/1 support for procfs
6944 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6945 possible to attach to running processes. As the mounting of the /proc
6946 filesystem is optional on the Alpha, GDB automatically determines
6947 the availability of /proc during startup. This can lead to problems
6948 if /proc is unmounted after GDB has been started.
6950 * Arguments to user-defined commands
6952 User commands may accept up to 10 arguments separated by whitespace.
6953 Arguments are accessed within the user command via $arg0..$arg9. A
6956 print $arg0 + $arg1 + $arg2
6958 To execute the command use:
6961 Defines the command "adder" which prints the sum of its three arguments.
6962 Note the arguments are text substitutions, so they may reference variables,
6963 use complex expressions, or even perform inferior function calls.
6965 * New `if' and `while' commands
6967 This makes it possible to write more sophisticated user-defined
6968 commands. Both commands take a single argument, which is the
6969 expression to evaluate, and must be followed by the commands to
6970 execute, one per line, if the expression is nonzero, the list being
6971 terminated by the word `end'. The `if' command list may include an
6972 `else' word, which causes the following commands to be executed only
6973 if the expression is zero.
6975 * Fortran source language mode
6977 GDB now includes partial support for Fortran 77. It will recognize
6978 Fortran programs and can evaluate a subset of Fortran expressions, but
6979 variables and functions may not be handled correctly. GDB will work
6980 with G77, but does not yet know much about symbols emitted by other
6983 * Better HPUX support
6985 Most debugging facilities now work on dynamic executables for HPPAs
6986 running hpux9 or later. You can attach to running dynamically linked
6987 processes, but by default the dynamic libraries will be read-only, so
6988 for instance you won't be able to put breakpoints in them. To change
6989 that behavior do the following before running the program:
6995 This will cause the libraries to be mapped private and read-write.
6996 To revert to the normal behavior, do this:
7002 You cannot set breakpoints or examine data in the library until after
7003 the library is loaded if the function/data symbols do not have
7006 GDB can now also read debug symbols produced by the HP C compiler on
7007 HPPAs (sorry, no C++, Fortran or 68k support).
7009 * Target byte order now dynamically selectable
7011 You can choose which byte order to use with a target system, via the
7012 commands "set endian big" and "set endian little", and you can see the
7013 current setting by using "show endian". You can also give the command
7014 "set endian auto", in which case GDB will use the byte order
7015 associated with the executable. Currently, only embedded MIPS
7016 configurations support dynamic selection of target byte order.
7018 * New DOS host serial code
7020 This version uses DPMI interrupts to handle buffered I/O, so you
7021 no longer need to run asynctsr when debugging boards connected to
7024 *** Changes in GDB-4.13:
7026 * New "complete" command
7028 This lists all the possible completions for the rest of the line, if it
7029 were to be given as a command itself. This is intended for use by emacs.
7031 * Trailing space optional in prompt
7033 "set prompt" no longer adds a space for you after the prompt you set. This
7034 allows you to set a prompt which ends in a space or one that does not.
7036 * Breakpoint hit counts
7038 "info break" now displays a count of the number of times the breakpoint
7039 has been hit. This is especially useful in conjunction with "ignore"; you
7040 can ignore a large number of breakpoint hits, look at the breakpoint info
7041 to see how many times the breakpoint was hit, then run again, ignoring one
7042 less than that number, and this will get you quickly to the last hit of
7045 * Ability to stop printing at NULL character
7047 "set print null-stop" will cause GDB to stop printing the characters of
7048 an array when the first NULL is encountered. This is useful when large
7049 arrays actually contain only short strings.
7051 * Shared library breakpoints
7053 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7054 breakpoints in shared libraries before the executable is run.
7056 * Hardware watchpoints
7058 There is a new hardware breakpoint for the watch command for sparclite
7059 targets. See gdb/sparclite/hw_breakpoint.note.
7061 Hardware watchpoints are also now supported under GNU/Linux.
7065 Annotations have been added. These are for use with graphical interfaces,
7066 and are still experimental. Currently only gdba.el uses these.
7068 * Improved Irix 5 support
7070 GDB now works properly with Irix 5.2.
7072 * Improved HPPA support
7074 GDB now works properly with the latest GCC and GAS.
7076 * New native configurations
7078 Sequent PTX4 i[34]86-sequent-ptx4
7079 HPPA running OSF/1 hppa*-*-osf*
7080 Atari TT running SVR4 m68*-*-sysv4*
7081 RS/6000 LynxOS rs6000-*-lynxos*
7085 OS/9000 i[34]86-*-os9k
7086 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7089 * Hitachi SH7000 and E7000-PC ICE support
7091 There is now support for communicating with the Hitachi E7000-PC ICE.
7092 This is available automatically when GDB is configured for the SH.
7096 As usual, a variety of small fixes and improvements, both generic
7097 and configuration-specific. See the ChangeLog for more detail.
7099 *** Changes in GDB-4.12:
7101 * Irix 5 is now supported
7105 GDB-4.12 on the HPPA has a number of changes which make it unable
7106 to debug the output from the currently released versions of GCC and
7107 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7108 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7109 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7112 *** Changes in GDB-4.11:
7114 * User visible changes:
7118 The "set remotedebug" option is now consistent between the mips remote
7119 target, remote targets using the gdb-specific protocol, UDI (AMD's
7120 debug protocol for the 29k) and the 88k bug monitor. It is now an
7121 integer specifying a debug level (normally 0 or 1, but 2 means more
7122 debugging info for the mips target).
7124 * DEC Alpha native support
7126 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7127 debug info, but GDB works fairly well with the DEC compiler and should
7128 work with a future GCC release. See the README file for a few
7129 Alpha-specific notes.
7131 * Preliminary thread implementation
7133 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7135 * LynxOS native and target support for 386
7137 This release has been hosted on LynxOS 2.2, and also can be configured
7138 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7141 * Improvements in C++ mangling/demangling.
7143 This release has much better g++ debugging, specifically in name
7144 mangling/demangling, virtual function calls, print virtual table,
7145 call methods, ...etc.
7147 *** Changes in GDB-4.10:
7149 * User visible changes:
7151 Remote debugging using the GDB-specific (`target remote') protocol now
7152 supports the `load' command. This is only useful if you have some
7153 other way of getting the stub to the target system, and you can put it
7154 somewhere in memory where it won't get clobbered by the download.
7156 Filename completion now works.
7158 When run under emacs mode, the "info line" command now causes the
7159 arrow to point to the line specified. Also, "info line" prints
7160 addresses in symbolic form (as well as hex).
7162 All vxworks based targets now support a user settable option, called
7163 vxworks-timeout. This option represents the number of seconds gdb
7164 should wait for responses to rpc's. You might want to use this if
7165 your vxworks target is, perhaps, a slow software simulator or happens
7166 to be on the far side of a thin network line.
7170 This release contains support for using a DEC alpha as a GDB host for
7171 cross debugging. Native alpha debugging is not supported yet.
7174 *** Changes in GDB-4.9:
7178 This is the first GDB release which is accompanied by a matching testsuite.
7179 The testsuite requires installation of dejagnu, which should be available
7180 via ftp from most sites that carry GNU software.
7184 'Cfront' style demangling has had its name changed to 'ARM' style, to
7185 emphasize that it was written from the specifications in the C++ Annotated
7186 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7187 disclaimers, it still generated too much confusion with users attempting to
7188 use gdb with AT&T cfront.
7192 GDB now uses a standard remote interface to a simulator library.
7193 So far, the library contains simulators for the Zilog Z8001/2, the
7194 Hitachi H8/300, H8/500 and Super-H.
7196 * New targets supported
7198 H8/300 simulator h8300-hitachi-hms or h8300hms
7199 H8/500 simulator h8500-hitachi-hms or h8500hms
7200 SH simulator sh-hitachi-hms or sh
7201 Z8000 simulator z8k-zilog-none or z8ksim
7202 IDT MIPS board over serial line mips-idt-ecoff
7204 Cross-debugging to GO32 targets is supported. It requires a custom
7205 version of the i386-stub.c module which is integrated with the
7206 GO32 memory extender.
7208 * New remote protocols
7210 MIPS remote debugging protocol.
7212 * New source languages supported
7214 This version includes preliminary support for Chill, a Pascal like language
7215 used by telecommunications companies. Chill support is also being integrated
7216 into the GNU compiler, but we don't know when it will be publically available.
7219 *** Changes in GDB-4.8:
7221 * HP Precision Architecture supported
7223 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7224 version of this support was available as a set of patches from the
7225 University of Utah. GDB does not support debugging of programs
7226 compiled with the HP compiler, because HP will not document their file
7227 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7228 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7230 Many problems in the preliminary version have been fixed.
7232 * Faster and better demangling
7234 We have improved template demangling and fixed numerous bugs in the GNU style
7235 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7236 character types (wchar_t) are now supported. Demangling of each symbol is now
7237 only done once, and is cached when the symbol table for a file is read in.
7238 This results in a small increase in memory usage for C programs, a moderate
7239 increase in memory usage for C++ programs, and a fantastic speedup in
7242 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7243 from the specifications in the Annotated Reference Manual, which AT&T's
7244 compiler does not actually implement.
7246 * G++ multiple inheritance compiler problem
7248 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7249 inheritance lattices was reworked to properly discover ambiguities. We
7250 recently found an example which causes this new algorithm to fail in a
7251 very subtle way, producing bad debug information for those classes.
7252 The file 'gcc.patch' (in this directory) can be applied to gcc to
7253 circumvent the problem. A future GCC release will contain a complete
7256 The previous G++ debug info problem (mentioned below for the gdb-4.7
7257 release) is fixed in gcc version 2.3.2.
7259 * Improved configure script
7261 The `configure' script will now attempt to guess your system type if
7262 you don't supply a host system type. The old scheme of supplying a
7263 host system triplet is preferable over using this. All the magic is
7264 done in the new `config.guess' script. Examine it for details.
7266 We have also brought our configure script much more in line with the FSF's
7267 version. It now supports the --with-xxx options. In particular,
7268 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7269 The resulting GDB will not be able to read arbitrary object file formats --
7270 only the format ``expected'' to be used on the configured target system.
7271 We hope to make this the default in a future release.
7273 * Documentation improvements
7275 There's new internal documentation on how to modify GDB, and how to
7276 produce clean changes to the code. We implore people to read it
7277 before submitting changes.
7279 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7280 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7281 `info' files are also provided. To build `info' files from scratch,
7282 you will need the latest `makeinfo' release, which will be available in
7283 a future texinfo-X.Y release.
7285 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7286 We're not sure exactly which versions have this problem, but it has
7287 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7288 or better. If that isn't possible, there is a patch in
7289 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7290 around this problem.
7294 GDB now supports array constants that can be used in expressions typed in by
7295 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7296 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7299 The new directory `gdb/sparclite' contains a program that demonstrates
7300 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7302 * New native hosts supported
7304 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7305 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7307 * New targets supported
7309 AMD 29k family via UDI a29k-amd-udi or udi29k
7311 * New file formats supported
7313 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7314 HPUX core files, and SCO 3.2v2 core files.
7318 Attaching to processes now works again; thanks for the many bug reports.
7320 We have also stomped on a bunch of core dumps caused by
7321 printf_filtered("%s") problems.
7323 We eliminated a copyright problem on the rpc and ptrace header files
7324 for VxWorks, which was discovered at the last minute during the 4.7
7325 release. You should now be able to build a VxWorks GDB.
7327 You can now interrupt gdb while an attached process is running. This
7328 will cause the attached process to stop, and give control back to GDB.
7330 We fixed problems caused by using too many file descriptors
7331 for reading symbols from object files and libraries. This was
7332 especially a problem for programs that used many (~100) shared
7335 The `step' command now only enters a subroutine if there is line number
7336 information for the subroutine. Otherwise it acts like the `next'
7337 command. Previously, `step' would enter subroutines if there was
7338 any debugging information about the routine. This avoids problems
7339 when using `cc -g1' on MIPS machines.
7341 * Internal improvements
7343 GDB's internal interfaces have been improved to make it easier to support
7344 debugging of multiple languages in the future.
7346 GDB now uses a common structure for symbol information internally.
7347 Minimal symbols (derived from linkage symbols in object files), partial
7348 symbols (from a quick scan of debug information), and full symbols
7349 contain a common subset of information, making it easier to write
7350 shared code that handles any of them.
7352 * New command line options
7354 We now accept --silent as an alias for --quiet.
7358 The memory-mapped-malloc library is now licensed under the GNU Library
7359 General Public License.
7361 *** Changes in GDB-4.7:
7363 * Host/native/target split
7365 GDB has had some major internal surgery to untangle the support for
7366 hosts and remote targets. Now, when you configure GDB for a remote
7367 target, it will no longer load in all of the support for debugging
7368 local programs on the host. When fully completed and tested, this will
7369 ensure that arbitrary host/target combinations are possible.
7371 The primary conceptual shift is to separate the non-portable code in
7372 GDB into three categories. Host specific code is required any time GDB
7373 is compiled on that host, regardless of the target. Target specific
7374 code relates to the peculiarities of the target, but can be compiled on
7375 any host. Native specific code is everything else: it can only be
7376 built when the host and target are the same system. Child process
7377 handling and core file support are two common `native' examples.
7379 GDB's use of /proc for controlling Unix child processes is now cleaner.
7380 It has been split out into a single module under the `target_ops' vector,
7381 plus two native-dependent functions for each system that uses /proc.
7383 * New hosts supported
7385 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7386 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7387 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7389 * New targets supported
7391 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7392 68030 and CPU32 m68030-*-*, m68332-*-*
7394 * New native hosts supported
7396 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7397 (386bsd is not well tested yet)
7398 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7400 * New file formats supported
7402 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7403 supports reading of `a.out.adobe' object files, which are an a.out
7404 format extended with minimal information about multiple sections.
7408 `show copying' is the same as the old `info copying'.
7409 `show warranty' is the same as `info warrantee'.
7410 These were renamed for consistency. The old commands continue to work.
7412 `info handle' is a new alias for `info signals'.
7414 You can now define pre-command hooks, which attach arbitrary command
7415 scripts to any command. The commands in the hook will be executed
7416 prior to the user's command. You can also create a hook which will be
7417 executed whenever the program stops. See gdb.texinfo.
7421 We now deal with Cfront style name mangling, and can even extract type
7422 info from mangled symbols. GDB can automatically figure out which
7423 symbol mangling style your C++ compiler uses.
7425 Calling of methods and virtual functions has been improved as well.
7429 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7430 fixed. This was due to mishandling of the extra N_SO stabs output
7433 We also finally got Ultrix 4.2 running in house, and fixed core file
7434 support, with help from a dozen people on the net.
7436 John M. Farrell discovered that the reason that single-stepping was so
7437 slow on all of the Mips based platforms (primarily SGI and DEC) was
7438 that we were trying to demangle and lookup a symbol used for internal
7439 purposes on every instruction that was being stepped through. Changing
7440 the name of that symbol so that it couldn't be mistaken for a C++
7441 mangled symbol sped things up a great deal.
7443 Rich Pixley sped up symbol lookups in general by getting much smarter
7444 about when C++ symbol mangling is necessary. This should make symbol
7445 completion (TAB on the command line) much faster. It's not as fast as
7446 we'd like, but it's significantly faster than gdb-4.6.
7450 A new user controllable variable 'call_scratch_address' can
7451 specify the location of a scratch area to be used when GDB
7452 calls a function in the target. This is necessary because the
7453 usual method of putting the scratch area on the stack does not work
7454 in systems that have separate instruction and data spaces.
7456 We integrated changes to support the 29k UDI (Universal Debugger
7457 Interface), but discovered at the last minute that we didn't have all
7458 of the appropriate copyright paperwork. We are working with AMD to
7459 resolve this, and hope to have it available soon.
7463 We have sped up the remote serial line protocol, especially for targets
7464 with lots of registers. It now supports a new `expedited status' ('T')
7465 message which can be used in place of the existing 'S' status message.
7466 This allows the remote stub to send only the registers that GDB
7467 needs to make a quick decision about single-stepping or conditional
7468 breakpoints, eliminating the need to fetch the entire register set for
7469 each instruction being stepped through.
7471 The GDB remote serial protocol now implements a write-through cache for
7472 registers, only re-reading the registers if the target has run.
7474 There is also a new remote serial stub for SPARC processors. You can
7475 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7476 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7477 processor with a serial port.
7481 Configure.in files have become much easier to read and modify. A new
7482 `table driven' format makes it more obvious what configurations are
7483 supported, and what files each one uses.
7487 There is a new opcodes library which will eventually contain all of the
7488 disassembly routines and opcode tables. At present, it only contains
7489 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7490 disassembler (binutils/objdump) to share these routines.
7492 The libiberty library is now copylefted under the GNU Library General
7493 Public License. This allows more liberal use, and was done so libg++
7494 can use it. This makes no difference to GDB, since the Library License
7495 grants all the rights from the General Public License.
7499 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7500 reference to the stabs symbol info used by the debugger. It is (as far
7501 as we know) the only published document on this fascinating topic. We
7502 encourage you to read it, compare it to the stabs information on your
7503 system, and send improvements on the document in general (to
7504 bug-gdb@prep.ai.mit.edu).
7506 And, of course, many bugs have been fixed.
7509 *** Changes in GDB-4.6:
7511 * Better support for C++ function names
7513 GDB now accepts as input the "demangled form" of C++ overloaded function
7514 names and member function names, and can do command completion on such names
7515 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7516 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7517 Make use of command completion, it is your friend.
7519 GDB also now accepts a variety of C++ mangled symbol formats. They are
7520 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7521 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7522 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7523 for the list of formats.
7525 * G++ symbol mangling problem
7527 Recent versions of gcc have a bug in how they emit debugging information for
7528 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7529 directory) can be applied to gcc to fix the problem. Alternatively, if you
7530 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7531 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7532 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7535 * New 'maintenance' command
7537 All of the commands related to hacking GDB internals have been moved out of
7538 the main command set, and now live behind the 'maintenance' command. This
7539 can also be abbreviated as 'mt'. The following changes were made:
7541 dump-me -> maintenance dump-me
7542 info all-breakpoints -> maintenance info breakpoints
7543 printmsyms -> maintenance print msyms
7544 printobjfiles -> maintenance print objfiles
7545 printpsyms -> maintenance print psymbols
7546 printsyms -> maintenance print symbols
7548 The following commands are new:
7550 maintenance demangle Call internal GDB demangler routine to
7551 demangle a C++ link name and prints the result.
7552 maintenance print type Print a type chain for a given symbol
7554 * Change to .gdbinit file processing
7556 We now read the $HOME/.gdbinit file before processing the argv arguments
7557 (e.g. reading symbol files or core files). This allows global parameters to
7558 be set, which will apply during the symbol reading. The ./.gdbinit is still
7559 read after argv processing.
7561 * New hosts supported
7563 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7565 GNU/Linux support i386-unknown-linux or linux
7567 We are also including code to support the HP/PA running BSD and HPUX. This
7568 is almost guaranteed not to work, as we didn't have time to test or build it
7569 for this release. We are including it so that the more adventurous (or
7570 masochistic) of you can play with it. We also had major problems with the
7571 fact that the compiler that we got from HP doesn't support the -g option.
7574 * New targets supported
7576 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7578 * More smarts about finding #include files
7580 GDB now remembers the compilation directory for all include files, and for
7581 all files from which C is generated (like yacc and lex sources). This
7582 greatly improves GDB's ability to find yacc/lex sources, and include files,
7583 especially if you are debugging your program from a directory different from
7584 the one that contains your sources.
7586 We also fixed a bug which caused difficulty with listing and setting
7587 breakpoints in include files which contain C code. (In the past, you had to
7588 try twice in order to list an include file that you hadn't looked at before.)
7590 * Interesting infernals change
7592 GDB now deals with arbitrary numbers of sections, where the symbols for each
7593 section must be relocated relative to that section's landing place in the
7594 target's address space. This work was needed to support ELF with embedded
7595 stabs used by Solaris-2.0.
7597 * Bug fixes (of course!)
7599 There have been loads of fixes for the following things:
7600 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7601 i960, stabs, DOS(GO32), procfs, etc...
7603 See the ChangeLog for details.
7605 *** Changes in GDB-4.5:
7607 * New machines supported (host and target)
7609 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7611 SGI Irix-4.x mips-sgi-irix4 or iris4
7613 * New malloc package
7615 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7616 Mmalloc is capable of handling multiple heaps of memory. It is also
7617 capable of saving a heap to a file, and then mapping it back in later.
7618 This can be used to greatly speedup the startup of GDB by using a
7619 pre-parsed symbol table which lives in a mmalloc managed heap. For
7620 more details, please read mmalloc/mmalloc.texi.
7624 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7625 'help info proc' for details.
7627 * MIPS ecoff symbol table format
7629 The code that reads MIPS symbol table format is now supported on all hosts.
7630 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7633 * File name changes for MS-DOS
7635 Many files in the config directories have been renamed to make it easier to
7636 support GDB on MS-DOSe systems (which have very restrictive file name
7637 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7638 environment) is close to working but has some remaining problems. Note
7639 that debugging of DOS programs is not supported, due to limitations
7640 in the ``operating system'', but it can be used to host cross-debugging.
7642 * Cross byte order fixes
7644 Many fixes have been made to support cross debugging of Sparc and MIPS
7645 targets from hosts whose byte order differs.
7647 * New -mapped and -readnow options
7649 If memory-mapped files are available on your system through the 'mmap'
7650 system call, you can use the -mapped option on the `file' or
7651 `symbol-file' commands to cause GDB to write the symbols from your
7652 program into a reusable file. If the program you are debugging is
7653 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7654 Future GDB debugging sessions will notice the presence of this file,
7655 and will quickly map in symbol information from it, rather than reading
7656 the symbol table from the executable program. Using the '-mapped'
7657 option in a GDB `file' or `symbol-file' command has the same effect as
7658 starting GDB with the '-mapped' command-line option.
7660 You can cause GDB to read the entire symbol table immediately by using
7661 the '-readnow' option with any of the commands that load symbol table
7662 information (or on the GDB command line). This makes the command
7663 slower, but makes future operations faster.
7665 The -mapped and -readnow options are typically combined in order to
7666 build a `fred.syms' file that contains complete symbol information.
7667 A simple GDB invocation to do nothing but build a `.syms' file for future
7670 gdb -batch -nx -mapped -readnow programname
7672 The `.syms' file is specific to the host machine on which GDB is run.
7673 It holds an exact image of GDB's internal symbol table. It cannot be
7674 shared across multiple host platforms.
7676 * longjmp() handling
7678 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7679 siglongjmp() without losing control. This feature has not yet been ported to
7680 all systems. It currently works on many 386 platforms, all MIPS-based
7681 platforms (SGI, DECstation, etc), and Sun3/4.
7685 Preliminary work has been put in to support the new Solaris OS from Sun. At
7686 this time, it can control and debug processes, but it is not capable of
7691 As always, many many bug fixes. The major areas were with g++, and mipsread.
7692 People using the MIPS-based platforms should experience fewer mysterious
7693 crashes and trashed symbol tables.
7695 *** Changes in GDB-4.4:
7697 * New machines supported (host and target)
7699 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7701 BSD Reno on Vax vax-dec-bsd
7702 Ultrix on Vax vax-dec-ultrix
7704 * New machines supported (target)
7706 AMD 29000 embedded, using EBMON a29k-none-none
7710 GDB continues to improve its handling of C++. `References' work better.
7711 The demangler has also been improved, and now deals with symbols mangled as
7712 per the Annotated C++ Reference Guide.
7714 GDB also now handles `stabs' symbol information embedded in MIPS
7715 `ecoff' symbol tables. Since the ecoff format was not easily
7716 extensible to handle new languages such as C++, this appeared to be a
7717 good way to put C++ debugging info into MIPS binaries. This option
7718 will be supported in the GNU C compiler, version 2, when it is
7721 * New features for SVR4
7723 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7724 shared libraries. Debugging dynamically linked programs should present
7725 only minor differences from debugging statically linked programs.
7727 The `info proc' command will print out information about any process
7728 on an SVR4 system (including the one you are debugging). At the moment,
7729 it prints the address mappings of the process.
7731 If you bring up GDB on another SVR4 system, please send mail to
7732 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7734 * Better dynamic linking support in SunOS
7736 Reading symbols from shared libraries which contain debugging symbols
7737 now works properly. However, there remain issues such as automatic
7738 skipping of `transfer vector' code during function calls, which
7739 make it harder to debug code in a shared library, than to debug the
7740 same code linked statically.
7744 GDB is now using the latest `getopt' routines from the FSF. This
7745 version accepts the -- prefix for options with long names. GDB will
7746 continue to accept the old forms (-option and +option) as well.
7747 Various single letter abbreviations for options have been explicity
7748 added to the option table so that they won't get overshadowed in the
7749 future by other options that begin with the same letter.
7753 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7754 Many assorted bugs have been handled. Many more remain to be handled.
7755 See the various ChangeLog files (primarily in gdb and bfd) for details.
7758 *** Changes in GDB-4.3:
7760 * New machines supported (host and target)
7762 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7763 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7764 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7766 * Almost SCO Unix support
7768 We had hoped to support:
7769 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7770 (except for core file support), but we discovered very late in the release
7771 that it has problems with process groups that render gdb unusable. Sorry
7772 about that. I encourage people to fix it and post the fixes.
7774 * Preliminary ELF and DWARF support
7776 GDB can read ELF object files on System V Release 4, and can handle
7777 debugging records for C, in DWARF format, in ELF files. This support
7778 is preliminary. If you bring up GDB on another SVR4 system, please
7779 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7784 GDB now uses the latest `readline' library. One user-visible change
7785 is that two tabs will list possible command completions, which previously
7786 required typing M-? (meta-question mark, or ESC ?).
7790 The `stepi' bug that many of you noticed has been squashed.
7791 Many bugs in C++ have been handled. Many more remain to be handled.
7792 See the various ChangeLog files (primarily in gdb and bfd) for details.
7794 * State of the MIPS world (in case you wondered):
7796 GDB can understand the symbol tables emitted by the compilers
7797 supplied by most vendors of MIPS-based machines, including DEC. These
7798 symbol tables are in a format that essentially nobody else uses.
7800 Some versions of gcc come with an assembler post-processor called
7801 mips-tfile. This program is required if you want to do source-level
7802 debugging of gcc-compiled programs. I believe FSF does not ship
7803 mips-tfile with gcc version 1, but it will eventually come with gcc
7806 Debugging of g++ output remains a problem. g++ version 1.xx does not
7807 really support it at all. (If you're lucky, you should be able to get
7808 line numbers and stack traces to work, but no parameters or local
7809 variables.) With some work it should be possible to improve the
7812 When gcc version 2 is released, you will have somewhat better luck.
7813 However, even then you will get confusing results for inheritance and
7816 We will eventually provide full debugging of g++ output on
7817 DECstations. This will probably involve some kind of stabs-in-ecoff
7818 encapulation, but the details have not been worked out yet.
7821 *** Changes in GDB-4.2:
7823 * Improved configuration
7825 Only one copy of `configure' exists now, and it is not self-modifying.
7826 Porting BFD is simpler.
7830 The `step' and `next' commands now only stop at the first instruction
7831 of a source line. This prevents the multiple stops that used to occur
7832 in switch statements, for-loops, etc. `Step' continues to stop if a
7833 function that has debugging information is called within the line.
7837 Lots of small bugs fixed. More remain.
7839 * New host supported (not target)
7841 Intel 386 PC clone running Mach i386-none-mach
7844 *** Changes in GDB-4.1:
7846 * Multiple source language support
7848 GDB now has internal scaffolding to handle several source languages.
7849 It determines the type of each source file from its filename extension,
7850 and will switch expression parsing and number formatting to match the
7851 language of the function in the currently selected stack frame.
7852 You can also specifically set the language to be used, with
7853 `set language c' or `set language modula-2'.
7857 GDB now has preliminary support for the GNU Modula-2 compiler,
7858 currently under development at the State University of New York at
7859 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7860 continue through the fall of 1991 and into 1992.
7862 Other Modula-2 compilers are currently not supported, and attempting to
7863 debug programs compiled with them will likely result in an error as the
7864 symbol table is read. Feel free to work on it, though!
7866 There are hooks in GDB for strict type checking and range checking,
7867 in the `Modula-2 philosophy', but they do not currently work.
7871 GDB can now write to executable and core files (e.g. patch
7872 a variable's value). You must turn this switch on, specify
7873 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7874 by assigning a new value to a variable. Modifications take
7877 * Automatic SunOS shared library reading
7879 When you run your program, GDB automatically determines where its
7880 shared libraries (if any) have been loaded, and reads their symbols.
7881 The `share' command is no longer needed. This also works when
7882 examining core files.
7886 You can specify the number of lines that the `list' command shows.
7889 * New machines supported (host and target)
7891 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7892 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7893 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7895 * New hosts supported (not targets)
7897 IBM RT/PC: romp-ibm-aix or rtpc
7899 * New targets supported (not hosts)
7901 AMD 29000 embedded with COFF a29k-none-coff
7902 AMD 29000 embedded with a.out a29k-none-aout
7903 Ultracomputer remote kernel debug a29k-nyu-kern
7905 * New remote interfaces
7911 *** Changes in GDB-4.0:
7915 Wide output is wrapped at good places to make the output more readable.
7917 Gdb now supports cross-debugging from a host machine of one type to a
7918 target machine of another type. Communication with the target system
7919 is over serial lines. The ``target'' command handles connecting to the
7920 remote system; the ``load'' command will download a program into the
7921 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7922 also supports debugging of realtime processes running under VxWorks,
7923 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7924 stub on the target system.
7926 New CPUs supported include the AMD 29000 and Intel 960.
7928 GDB now reads object files and symbol tables via a ``binary file''
7929 library, which allows a single copy of GDB to debug programs of multiple
7930 object file types such as a.out and coff.
7932 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7933 refcard.dvi and refcard.ps are available to format it).
7936 * Control-Variable user interface simplified
7938 All variables that control the operation of the debugger can be set
7939 by the ``set'' command, and displayed by the ``show'' command.
7941 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7942 ``Show prompt'' produces the response:
7943 Gdb's prompt is new-gdb=>.
7945 What follows are the NEW set commands. The command ``help set'' will
7946 print a complete list of old and new set commands. ``help set FOO''
7947 will give a longer description of the variable FOO. ``show'' will show
7948 all of the variable descriptions and their current settings.
7950 confirm on/off: Enables warning questions for operations that are
7951 hard to recover from, e.g. rerunning the program while
7952 it is already running. Default is ON.
7954 editing on/off: Enables EMACS style command line editing
7955 of input. Previous lines can be recalled with
7956 control-P, the current line can be edited with control-B,
7957 you can search for commands with control-R, etc.
7960 history filename NAME: NAME is where the gdb command history
7961 will be stored. The default is .gdb_history,
7962 or the value of the environment variable
7965 history size N: The size, in commands, of the command history. The
7966 default is 256, or the value of the environment variable
7969 history save on/off: If this value is set to ON, the history file will
7970 be saved after exiting gdb. If set to OFF, the
7971 file will not be saved. The default is OFF.
7973 history expansion on/off: If this value is set to ON, then csh-like
7974 history expansion will be performed on
7975 command line input. The default is OFF.
7977 radix N: Sets the default radix for input and output. It can be set
7978 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7979 in the current radix, so "set radix 10" is always a no-op.
7981 height N: This integer value is the number of lines on a page. Default
7982 is 24, the current `stty rows'' setting, or the ``li#''
7983 setting from the termcap entry matching the environment
7986 width N: This integer value is the number of characters on a line.
7987 Default is 80, the current `stty cols'' setting, or the ``co#''
7988 setting from the termcap entry matching the environment
7991 Note: ``set screensize'' is obsolete. Use ``set height'' and
7992 ``set width'' instead.
7994 print address on/off: Print memory addresses in various command displays,
7995 such as stack traces and structure values. Gdb looks
7996 more ``symbolic'' if you turn this off; it looks more
7997 ``machine level'' with it on. Default is ON.
7999 print array on/off: Prettyprint arrays. New convenient format! Default
8002 print demangle on/off: Print C++ symbols in "source" form if on,
8005 print asm-demangle on/off: Same, for assembler level printouts
8008 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8011 * Support for Epoch Environment.
8013 The epoch environment is a version of Emacs v18 with windowing. One
8014 new command, ``inspect'', is identical to ``print'', except that if you
8015 are running in the epoch environment, the value is printed in its own
8019 * Support for Shared Libraries
8021 GDB can now debug programs and core files that use SunOS shared libraries.
8022 Symbols from a shared library cannot be referenced
8023 before the shared library has been linked with the program (this
8024 happens after you type ``run'' and before the function main() is entered).
8025 At any time after this linking (including when examining core files
8026 from dynamically linked programs), gdb reads the symbols from each
8027 shared library when you type the ``sharedlibrary'' command.
8028 It can be abbreviated ``share''.
8030 sharedlibrary REGEXP: Load shared object library symbols for files
8031 matching a unix regular expression. No argument
8032 indicates to load symbols for all shared libraries.
8034 info sharedlibrary: Status of loaded shared libraries.
8039 A watchpoint stops execution of a program whenever the value of an
8040 expression changes. Checking for this slows down execution
8041 tremendously whenever you are in the scope of the expression, but is
8042 quite useful for catching tough ``bit-spreader'' or pointer misuse
8043 problems. Some machines such as the 386 have hardware for doing this
8044 more quickly, and future versions of gdb will use this hardware.
8046 watch EXP: Set a watchpoint (breakpoint) for an expression.
8048 info watchpoints: Information about your watchpoints.
8050 delete N: Deletes watchpoint number N (same as breakpoints).
8051 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8052 enable N: Re-enables watchpoint number N (same as breakpoints).
8055 * C++ multiple inheritance
8057 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8060 * C++ exception handling
8062 Gdb now supports limited C++ exception handling. Besides the existing
8063 ability to breakpoint on an exception handler, gdb can breakpoint on
8064 the raising of an exception (before the stack is peeled back to the
8067 catch FOO: If there is a FOO exception handler in the dynamic scope,
8068 set a breakpoint to catch exceptions which may be raised there.
8069 Multiple exceptions (``catch foo bar baz'') may be caught.
8071 info catch: Lists all exceptions which may be caught in the
8072 current stack frame.
8075 * Minor command changes
8077 The command ``call func (arg, arg, ...)'' now acts like the print
8078 command, except it does not print or save a value if the function's result
8079 is void. This is similar to dbx usage.
8081 The ``up'' and ``down'' commands now always print the frame they end up
8082 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8083 frames without printing.
8085 * New directory command
8087 'dir' now adds directories to the FRONT of the source search path.
8088 The path starts off empty. Source files that contain debug information
8089 about the directory in which they were compiled can be found even
8090 with an empty path; Sun CC and GCC include this information. If GDB can't
8091 find your source file in the current directory, type "dir .".
8093 * Configuring GDB for compilation
8095 For normal use, type ``./configure host''. See README or gdb.texinfo
8098 GDB now handles cross debugging. If you are remotely debugging between
8099 two different machines, type ``./configure host -target=targ''.
8100 Host is the machine where GDB will run; targ is the machine
8101 where the program that you are debugging will run.