1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 10
6 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
11 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
13 The MI -break-insert and -dprintf-insert commands now support a
14 new "--qualified" option that makes GDB interpret a specified
15 function name as a complete fully-qualified name. This is the
16 equivalent of the CLI's "break -qualified" and "dprintf
19 * GDB now supports core file debugging for x86_64 Cygwin programs.
21 * GDB will now look for the .gdbinit file in a config directory before
22 looking for ~/.gdbinit. The file is searched for in the following
23 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
24 $HOME/.gdbinit. On Apple hosts the search order is instead:
25 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
31 Control the display of debug output about GDB's event loop.
35 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
36 [-force-condition] [if CONDITION]
37 This command would previously refuse setting a breakpoint if the
38 CONDITION expression is invalid at a location. It now accepts and
39 defines the breakpoint if there is at least one location at which
40 the CONDITION is valid. The locations for which the CONDITION is
41 invalid, are automatically disabled. If CONDITION is invalid at all
42 of the locations, setting the breakpoint is still rejected. However,
43 the '-force-condition' flag can be used in this case for forcing GDB to
44 define the breakpoint, making all the current locations automatically
45 disabled. This may be useful if the user knows the condition will
46 become meaningful at a future location, e.g. due to a shared library
49 condition [-force] N COND
50 The behavior of this command is changed the same way for the 'break'
51 command as explained above. The '-force' flag can be used to force
52 GDB into defining the condition even when COND is invalid for all the
53 current locations of breakpoint N.
57 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
58 and "org.gnu.gdb.arc.aux". The old names are still supported but
59 must be considered obsolete. They will be deprecated after some
62 * Help and apropos commands will now show the documentation of a
63 command only once, even if that command has one or more aliases.
64 These commands now show the command name, then all of its aliases,
65 and finally the description of the command.
67 * 'help aliases' now shows only the user defined aliases. GDB predefined
68 aliases are shown together with their aliased command.
70 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
71 debugging information as well as source code.
73 When built with debuginfod, GDB can automatically query debuginfod
74 servers for the separate debug files and source code of the executable
77 To build GDB with debuginfod, pass --with-debuginfod to configure (this
78 requires libdebuginfod, the debuginfod client library).
80 debuginfod is distributed with elfutils, starting with version 0.178.
82 You can get the latest version from https://sourceware.org/elfutils.
84 * Multi-target debugging support
86 GDB now supports debugging multiple target connections
87 simultaneously. For example, you can now have each inferior
88 connected to different remote servers running in different machines,
89 or have one inferior debugging a local native process, an inferior
90 debugging a core dump, etc.
92 This support is experimental and comes with some limitations -- you
93 can only resume multiple targets simultaneously if all targets
94 support non-stop mode, and all remote stubs or servers must support
95 the same set of remote protocol features exactly. See also "info
96 connections" and "add-inferior -no-connection" below, and "maint set
97 target-non-stop" in the user manual.
99 * New features in the GDB remote stub, GDBserver
101 ** GDBserver is now supported on ARC GNU/Linux.
103 ** GDBserver is now supported on RISC-V GNU/Linux.
105 ** GDBserver no longer supports these host triplets:
116 i[34567]86-*-mingw32ce*
118 * Debugging MS-Windows processes now sets $_exitsignal when the
119 inferior is terminated by a signal, instead of setting $_exitcode.
121 * Multithreaded symbol loading has now been enabled by default on systems
122 that support it (see entry for GDB 9, below), providing faster
123 performance for programs with many symbols.
125 * The $_siginfo convenience variable now also works on Windows targets,
126 and will display the EXCEPTION_RECORD of the last handled exception.
128 * TUI windows can now be arranged horizontally.
130 * The command history filename can now be set to the empty string
131 either using 'set history filename' or by setting 'GDBHISTFILE=' in
132 the environment. The effect of setting this filename to the empty
133 string is that GDB will not try to load any previous command
136 * On Windows targets, it is now possible to debug 32-bit programs with a
141 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
142 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
143 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
144 running process, this new option indicates whether to detect
145 a mismatch between the current executable file loaded by GDB and the
146 executable file used to start the process. If 'ask', the default,
147 display a warning and ask the user whether to load the process
148 executable file; if 'warn', just display a warning; if 'off', don't
149 attempt to detect a mismatch.
151 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
152 Define a new TUI layout, specifying its name and the windows that
155 maintenance print xml-tdesc [FILE]
156 Prints the current target description as an XML document. If the
157 optional FILE is provided (which is an XML target description) then
158 the target description is read from FILE into GDB, and then
161 maintenance print core-file-backed-mappings
162 Prints file-backed mappings loaded from a core file's note section.
163 Output is expected to be similar to that of "info proc mappings".
165 set debug fortran-array-slicing on|off
166 show debug fortran-array-slicing
167 Print debugging when taking slices of Fortran arrays.
169 set fortran repack-array-slices on|off
170 show fortran repack-array-slices
171 When taking slices from Fortran arrays and strings, if the slice is
172 non-contiguous within the original value then, when this option is
173 on, the new value will be repacked into a single contiguous value.
174 When this option is off, then the value returned will consist of a
175 descriptor that describes the slice within the memory of the
176 original parent value.
180 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
181 The alias command can now specify default args for an alias.
182 GDB automatically prepends the alias default args to the argument list
183 provided explicitly by the user.
184 For example, to have a backtrace with full details, you can define
186 'alias bt_ALL = backtrace -entry-values both -frame-arg all
187 -past-main -past-entry -full'.
188 Alias default arguments can also use a set of nested 'with' commands,
189 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
190 defines the alias pp10 that will pretty print a maximum of 10 elements
191 of the given expression (if the expression is an array).
195 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
200 ** gdb.register_window_type can be used to implement new TUI windows
203 ** Dynamic types can now be queried. gdb.Type has a new attribute,
204 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
205 field of a dynamic type may have None for its "bitpos" attribute
208 ** Commands written in Python can be in the "TUI" help class by
209 registering with the new constant gdb.COMMAND_TUI.
211 ** New method gdb.PendingFrame.architecture () to retrieve the
212 architecture of the pending frame.
214 ** New gdb.Architecture.registers method that returns a
215 gdb.RegisterDescriptorIterator object, an iterator that returns
216 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
217 way to query the registers available for an architecture.
219 ** New gdb.Architecture.register_groups method that returns a
220 gdb.RegisterGroupIterator object, an iterator that returns
221 gdb.RegisterGroup objects. The new RegisterGroup is a way to
222 discover the available register groups.
226 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
228 ** Procedures 'memory-port-read-buffer-size',
229 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
230 and 'set-memory-port-write-buffer-size!' are deprecated. When
231 using Guile 2.2 and later, users who need to control the size of
232 a memory port's internal buffer can use the 'setvbuf' procedure.
236 * 'thread-exited' event is now available in the annotations interface.
238 * New built-in convenience variables $_gdb_major and $_gdb_minor
239 provide the GDB version. They are handy for conditionally using
240 features available only in or since specific GDB versions, in
241 scripts that should work error-free with many different versions,
242 such as in system-wide init files.
244 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
245 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
246 of the GDB settings and the GDB maintenance settings. They are handy
247 for changing the logic of user defined commands depending on the
248 current GDB settings.
250 * GDB now supports Thread Local Storage (TLS) variables on several
251 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
252 architectures require kernel changes. TLS is not yet supported for
253 amd64 and i386 process core dumps.
255 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
256 addresses that required unmasking are shown in the backtrace with the
259 * Two new convenience functions $_cimag and $_creal that extract the
260 imaginary and real parts respectively from complex numbers.
262 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
263 provide the exitcode or exit status of the shell commands launched by
264 GDB commands such as "shell", "pipe" and "make".
266 * The command define-prefix can now define user defined prefix commands.
267 User defined commands can now be defined using these user defined prefix
270 * Command names can now use the . character.
272 * The RX port now supports XML target descriptions.
274 * GDB now shows the Ada task names at more places, e.g. in task switching
277 * GDB can now be compiled with Python 3 on Windows.
279 * New convenience variable $_ada_exception holds the address of the
280 Ada exception being thrown. This is set by Ada-related catchpoints.
282 * GDB can now place breakpoints on nested functions and subroutines in
283 Fortran code. The '::' operator can be used between parent and
284 child scopes when placing breakpoints, for example:
286 (gdb) break outer_function::inner_function
288 The 'outer_function::' prefix is only needed if 'inner_function' is
289 not visible in the current scope.
291 * In addition to the system-wide gdbinit file, if configured with
292 --with-system-gdbinit-dir, GDB will now also load files in that directory
293 as system gdbinit files, unless the -nx or -n flag is provided. Files
294 with extensions .gdb, .py and .scm are supported as long as GDB was
295 compiled with support for that language.
297 * GDB now supports multithreaded symbol loading for higher performance.
298 This feature is still in testing, so it is disabled by default. You
299 can turn it on using 'maint set worker-threads unlimited'.
303 ** The gdb.Value type has a new method 'format_string' which returns a
304 string representing the value. The formatting is controlled by the
305 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
306 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
307 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
309 ** gdb.Type has a new property 'objfile' which returns the objfile the
312 ** The frame information printed by the python frame filtering code
313 is now consistent with what the 'backtrace' command prints when
314 there are no filters, or when the 'backtrace' '-no-filters' option
317 ** The new function gdb.lookup_static_symbol can be used to look up
318 symbols with static linkage.
320 ** The new function gdb.lookup_static_symbols can be used to look up
321 all static symbols with static linkage.
323 ** gdb.Objfile has new methods 'lookup_global_symbol' and
324 'lookup_static_symbol' to lookup a symbol from this objfile only.
326 ** gdb.Block now supports the dictionary syntax for accessing symbols in
327 this block (e.g. block['local_variable']).
331 | [COMMAND] | SHELL_COMMAND
332 | -d DELIM COMMAND DELIM SHELL_COMMAND
333 pipe [COMMAND] | SHELL_COMMAND
334 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
335 Executes COMMAND and sends its output to SHELL_COMMAND.
336 With no COMMAND, repeat the last executed command
337 and send its output to SHELL_COMMAND.
339 define-prefix COMMAND
340 Define or mark a command as a user-defined prefix command.
342 with SETTING [VALUE] [-- COMMAND]
343 w SETTING [VALUE] [-- COMMAND]
344 Temporarily set SETTING, run COMMAND, and restore SETTING.
345 Usage: with SETTING -- COMMAND
346 With no COMMAND, repeats the last executed command.
347 SETTING is any GDB setting you can change with the "set"
348 subcommands. For example, 'with language c -- print someobj'
349 temporarily switches to the C language in order to print someobj.
350 Settings can be combined: 'w lang c -- w print elements unlimited --
351 usercmd' switches to the C language and runs usercmd with no limit
352 of array elements to print.
354 maint with SETTING [VALUE] [-- COMMAND]
355 Like "with", but works with "maintenance set" settings.
357 set may-call-functions [on|off]
358 show may-call-functions
359 This controls whether GDB will attempt to call functions in
360 the program, such as with expressions in the print command. It
361 defaults to on. Calling functions in the program being debugged
362 can have undesired side effects. It is now possible to forbid
363 such function calls. If function calls are forbidden, GDB will throw
364 an error when a command (such as print expression) calls a function
367 set print finish [on|off]
369 This controls whether the `finish' command will display the value
370 that is returned by the current function. When `off', the value is
371 still entered into the value history, but it is not printed. The
376 Allows deeply nested structures to be simplified when printing by
377 replacing deeply nested parts (beyond the max-depth) with ellipses.
378 The default max-depth is 20, but this can be set to unlimited to get
379 the old behavior back.
381 set print raw-values [on|off]
382 show print raw-values
383 By default, GDB applies the enabled pretty printers when printing a
384 value. This allows to ignore the enabled pretty printers for a series
385 of commands. The default is 'off'.
387 set logging debugredirect [on|off]
388 By default, GDB debug output will go to both the terminal and the logfile.
389 Set if you want debug output to go only to the log file.
391 set style title foreground COLOR
392 set style title background COLOR
393 set style title intensity VALUE
394 Control the styling of titles.
396 set style highlight foreground COLOR
397 set style highlight background COLOR
398 set style highlight intensity VALUE
399 Control the styling of highlightings.
401 maint set worker-threads
402 maint show worker-threads
403 Control the number of worker threads that can be used by GDB. The
404 default is 0. "unlimited" lets GDB choose a number that is
405 reasonable. Currently worker threads are only used when demangling
406 the names of linker symbols.
408 set style tui-border foreground COLOR
409 set style tui-border background COLOR
410 Control the styling of TUI borders.
412 set style tui-active-border foreground COLOR
413 set style tui-active-border background COLOR
414 Control the styling of the active TUI border.
416 maint set test-settings KIND
417 maint show test-settings KIND
418 A set of commands used by the testsuite for exercising the settings
421 maint set tui-resize-message [on|off]
422 maint show tui-resize-message
423 Control whether GDB prints a message each time the terminal is
424 resized when in TUI mode. This is primarily useful for testing the
427 set print frame-info [short-location|location|location-and-address
428 |source-and-location|source-line|auto]
429 show print frame-info
430 This controls what frame information is printed by the commands printing
431 a frame. This setting will e.g. influence the behaviour of 'backtrace',
432 'frame', 'stepi'. The python frame filtering also respect this setting.
433 The 'backtrace' '-frame-info' option can override this global setting.
435 set tui compact-source
436 show tui compact-source
438 Enable the "compact" display mode for the TUI source window. The
439 compact display uses only as much space as is needed for the line
440 numbers in the current file, and only a single space to separate the
441 line numbers from the source.
443 info modules [-q] [REGEXP]
444 Return a list of Fortran modules matching REGEXP, or all modules if
447 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
448 Return a list of functions within all modules, grouped by module.
449 The list of functions can be restricted with the optional regular
450 expressions. MODULE_REGEXP matches against the module name,
451 TYPE_REGEXP matches against the function type signature, and REGEXP
452 matches against the function name.
454 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
455 Return a list of variables within all modules, grouped by module.
456 The list of variables can be restricted with the optional regular
457 expressions. MODULE_REGEXP matches against the module name,
458 TYPE_REGEXP matches against the variable type, and REGEXP matches
459 against the variable name.
461 set debug remote-packet-max-chars
462 show debug remote-packet-max-chars
463 Controls the number of characters to output in a remote packet when using
465 The default is 512 bytes.
468 Lists the target connections currently in use.
473 The "help" command uses the title style to enhance the
474 readibility of its output by styling the classes and
478 Similarly to "help", the "apropos" command also uses the
479 title style for the command names. "apropos" accepts now
480 a flag "-v" (verbose) to show the full documentation
481 of matching commands and to use the highlight style to mark
482 the documentation parts matching REGEXP.
486 The GDB printf and eval commands can now print C-style and Ada-style
487 string convenience variables without calling functions in the program.
488 This allows to do formatted printing of strings without having
489 a running inferior, or when debugging a core dump.
491 info sources [-dirname | -basename] [--] [REGEXP]
492 This command has now optional arguments to only print the files
493 whose names match REGEXP. The arguments -dirname and -basename
494 allow to restrict matching respectively to the dirname and basename
498 The "show style" and its subcommands are now styling
499 a style name in their output using its own style, to help
500 the user visualize the different styles.
502 set print frame-arguments
503 The new value 'presence' indicates to only indicate the presence of
504 arguments using ..., instead of printing argument names and values.
506 set print raw-frame-arguments
507 show print raw-frame-arguments
509 These commands replace the similarly-named "set/show print raw
510 frame-arguments" commands (now with a dash instead of a space). The
511 old commands are now deprecated and may be removed in a future
514 add-inferior [-no-connection]
515 The add-inferior command now supports a "-no-connection" flag that
516 makes the new inferior start with no target connection associated.
517 By default, the new inferior inherits the target connection of the
518 current inferior. See also "info connections".
521 This command's output now includes a new "Connection" column
522 indicating which target connection an inferior is bound to. See
523 "info connections" above.
525 maint test-options require-delimiter
526 maint test-options unknown-is-error
527 maint test-options unknown-is-operand
528 maint show test-options-completion-result
529 Commands used by the testsuite to validate the command options
532 focus, winheight, +, -, >, <
533 These commands are now case-sensitive.
535 * New command options, command completion
537 GDB now has a standard infrastructure to support dash-style command
538 options ('-OPT'). One benefit is that commands that use it can
539 easily support completion of command line arguments. Try "CMD
540 -[TAB]" or "help CMD" to find options supported by a command. Over
541 time, we intend to migrate most commands to this infrastructure. A
542 number of commands got support for new command options in this
545 ** The "print" and "compile print" commands now support a number of
546 options that allow overriding relevant global print settings as
547 set by "set print" subcommands:
551 -array-indexes [on|off]
552 -elements NUMBER|unlimited
557 -repeats NUMBER|unlimited
558 -static-members [on|off]
563 Note that because the "print"/"compile print" commands accept
564 arbitrary expressions which may look like options (including
565 abbreviations), if you specify any command option, then you must
566 use a double dash ("--") to mark the end of argument processing.
568 ** The "backtrace" command now supports a number of options that
569 allow overriding relevant global print settings as set by "set
570 backtrace" and "set print" subcommands:
572 -entry-values no|only|preferred|if-needed|both|compact|default
573 -frame-arguments all|scalars|none
574 -raw-frame-arguments [on|off]
575 -frame-info auto|source-line|location|source-and-location
576 |location-and-address|short-location
580 In addition, the full/no-filters/hide qualifiers are now also
581 exposed as command options too:
587 ** The "frame apply", "tfaas" and "faas" commands similarly now
588 support the following options:
593 ** The new "info sources" options -dirname and -basename options
594 are using the standard '-OPT' infrastructure.
596 All options above can also be abbreviated. The argument of boolean
597 (on/off) options can be 0/1 too, and also the argument is assumed
598 "on" if omitted. This allows writing compact command invocations,
601 (gdb) p -ra -p -o 0 -- *myptr
603 The above is equivalent to:
605 (gdb) print -raw-values -pretty -object off -- *myptr
607 ** The "info types" command now supports the '-q' flag to disable
608 printing of some header information in a similar fashion to "info
609 variables" and "info functions".
611 ** The "info variables", "info functions", and "whereis" commands
612 now take a '-n' flag that excludes non-debug symbols (symbols
613 from the symbol table, not from the debug info such as DWARF)
616 * Completion improvements
618 ** GDB can now complete the options of the "thread apply all" and
619 "taas" commands, and their "-ascending" option can now be
622 ** GDB can now complete the options of the "info threads", "info
623 functions", "info variables", "info locals", and "info args"
626 ** GDB can now complete the options of the "compile file" and
627 "compile code" commands. The "compile file" command now
628 completes on filenames.
630 ** GDB can now complete the backtrace command's
631 "full/no-filters/hide" qualifiers.
633 * In settings, you can now abbreviate "unlimited".
635 E.g., "set print elements u" is now equivalent to "set print
641 This lists all the possible completions for the rest of the line, if it
642 were to be given as a command itself. This is intended for use by MI
643 frontends in cases when separate CLI and MI channels cannot be used.
645 -catch-throw, -catch-rethrow, and -catch-catch
646 These can be used to catch C++ exceptions in a similar fashion to
647 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
649 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
650 These commands are the MI equivalent of the CLI commands 'info
651 functions', 'info types', and 'info variables' respectively.
653 -symbol-info-modules, this is the MI equivalent of the CLI 'info
656 -symbol-info-module-functions and -symbol-info-module-variables.
657 These commands are the MI equivalent of the CLI commands 'info
658 module functions' and 'info module variables'.
662 ** The default version of the MI interpreter is now 3 (-i=mi3).
664 ** The output of information about multi-location breakpoints (which is
665 syntactically incorrect in MI 2) has changed in MI 3. This affects
666 the following commands and events:
670 - =breakpoint-created
671 - =breakpoint-modified
673 The -fix-multi-location-breakpoint-output command can be used to enable
674 this behavior with previous MI versions.
676 ** Backtraces and frames include a new optional field addr_flags which is
677 given after the addr field. On AArch64 this contains PAC if the address
678 has been masked in the frame. On all other targets the field is not
683 The testsuite now creates the files gdb.cmd (containing the arguments
684 used to launch GDB) and gdb.in (containing all the commands sent to
685 GDB) in the output directory for each test script. Multiple invocations
686 are appended with .1, .2, .3 etc.
688 * Building GDB and GDBserver now requires GNU make >= 3.82.
690 Using another implementation of the make program or an earlier version of
691 GNU make to build GDB or GDBserver is not supported.
693 * Building GDB now requires GNU readline >= 7.0.
695 GDB now bundles GNU readline 8.0, but if you choose to use
696 --with-system-readline, only readline >= 7.0 can be used.
698 * The TUI SingleKey keymap is now named "SingleKey". This can be used
699 from .inputrc to bind keys in this keymap. This feature is only
700 available when gdb is built against GNU readline 8.0 or later.
702 * Removed targets and native configurations
704 GDB no longer supports debugging the Cell Broadband Engine. This includes
705 both debugging standalone Cell/B.E. SPU applications and integrated debugging
706 of Cell/B.E. applications that use both the PPU and SPU architectures.
712 * Removed targets and native configurations
714 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
717 *** Changes in GDB 8.3
719 * GDB and GDBserver now support access to additional registers on
720 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
723 * GDB now has experimental support for the compilation and injection of
724 C++ source code into the inferior. This beta release does not include
725 support for several language features, such as templates, constructors,
728 This feature requires GCC 7.1 or higher built with libcp1.so
731 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
732 can be passed using the '[ADDRESS]:PORT' notation, or the regular
733 'ADDRESS:PORT' method.
735 * DWARF index cache: GDB can now automatically save indices of DWARF
736 symbols on disk to speed up further loading of the same binaries.
738 * Ada task switching is now supported on aarch64-elf targets when
739 debugging a program using the Ravenscar Profile. For more information,
740 see the "Tasking Support when using the Ravenscar Profile" section
741 in the GDB user manual.
743 * GDB in batch mode now exits with status 1 if the last command to be
746 * The RISC-V target now supports target descriptions.
748 * System call catchpoints now support system call aliases on FreeBSD.
749 When the ABI of a system call changes in FreeBSD, this is
750 implemented by leaving a compatibility system call using the old ABI
751 at the existing number and allocating a new system call number for
752 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
753 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
754 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
755 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
756 so that a system call catchpoint for the 'kevent' system call will
757 catch invocations of both the 'kevent' and 'freebsd11_kevent'
758 binaries. This ensures that 'kevent' system calls are caught for
759 binaries using either the old or new ABIs.
761 * Terminal styling is now available for the CLI and the TUI. GNU
762 Source Highlight can additionally be used to provide styling of
763 source code snippets. See the "set style" commands, below, for more
766 * Removed support for old demangling styles arm, edg, gnu, hp and
771 set debug compile-cplus-types
772 show debug compile-cplus-types
773 Control the display of debug output about type conversion in the
774 C++ compile feature. Commands have no effect while compiling
779 Control whether debug output about files/functions skipping is
782 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
783 Apply a command to some frames.
784 FLAG arguments allow to control what output to produce and how to handle
785 errors raised when applying COMMAND to a frame.
788 Apply a command to all threads (ignoring errors and empty output).
789 Shortcut for 'thread apply all -s COMMAND'.
792 Apply a command to all frames (ignoring errors and empty output).
793 Shortcut for 'frame apply all -s COMMAND'.
796 Apply a command to all frames of all threads (ignoring errors and empty
798 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
800 maint set dwarf unwinders (on|off)
801 maint show dwarf unwinders
802 Control whether DWARF unwinders can be used.
805 Display a list of open files for a process.
809 Changes to the "frame", "select-frame", and "info frame" CLI commands.
810 These commands all now take a frame specification which
811 is either a frame level, or one of the keywords 'level', 'address',
812 'function', or 'view' followed by a parameter. Selecting a frame by
813 address, or viewing a frame outside the current backtrace now
814 requires the use of a keyword. Selecting a frame by level is
815 unchanged. The MI comment "-stack-select-frame" is unchanged.
817 target remote FILENAME
818 target extended-remote FILENAME
819 If FILENAME is a Unix domain socket, GDB will attempt to connect
820 to this socket instead of opening FILENAME as a character device.
822 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
823 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
824 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
825 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
826 These commands can now print only the searched entities
827 matching the provided regexp(s), giving a condition
828 on the entity names or entity types. The flag -q disables
829 printing headers or informations messages.
835 These commands now determine the syntax for the shown entities
836 according to the language chosen by `set language'. In particular,
837 `set language auto' means to automatically choose the language of
840 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
841 The 'thread apply' command accepts new FLAG arguments.
842 FLAG arguments allow to control what output to produce and how to handle
843 errors raised when applying COMMAND to a thread.
845 set tui tab-width NCHARS
846 show tui tab-width NCHARS
847 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
849 set style enabled [on|off]
851 Enable or disable terminal styling. Styling is enabled by default
852 on most hosts, but disabled by default when in batch mode.
854 set style sources [on|off]
856 Enable or disable source code styling. Source code styling is
857 enabled by default, but only takes effect if styling in general is
858 enabled, and if GDB was linked with GNU Source Highlight.
860 set style filename foreground COLOR
861 set style filename background COLOR
862 set style filename intensity VALUE
863 Control the styling of file names.
865 set style function foreground COLOR
866 set style function background COLOR
867 set style function intensity VALUE
868 Control the styling of function names.
870 set style variable foreground COLOR
871 set style variable background COLOR
872 set style variable intensity VALUE
873 Control the styling of variable names.
875 set style address foreground COLOR
876 set style address background COLOR
877 set style address intensity VALUE
878 Control the styling of addresses.
882 ** The '-data-disassemble' MI command now accepts an '-a' option to
883 disassemble the whole function surrounding the given program
884 counter value or function name. Support for this feature can be
885 verified by using the "-list-features" command, which should
886 contain "data-disassemble-a-option".
888 ** Command responses and notifications that include a frame now include
889 the frame's architecture in a new "arch" attribute.
891 * New native configurations
893 GNU/Linux/RISC-V riscv*-*-linux*
894 FreeBSD/riscv riscv*-*-freebsd*
898 GNU/Linux/RISC-V riscv*-*-linux*
900 CSKY GNU/LINUX csky*-*-linux
901 FreeBSD/riscv riscv*-*-freebsd*
903 GNU/Linux/OpenRISC or1k*-*-linux*
907 GDB no longer supports native debugging on versions of MS-Windows
912 ** GDB no longer supports Python versions less than 2.6.
914 ** The gdb.Inferior type has a new 'progspace' property, which is the program
915 space associated to that inferior.
917 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
918 of objfiles associated to that program space.
920 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
921 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
924 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
925 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
926 correct and did not work properly.
928 ** The gdb.Value type has a new constructor, which is used to construct a
929 gdb.Value from a Python buffer object and a gdb.Type.
935 Enable or disable the undefined behavior sanitizer. This is
936 disabled by default, but passing --enable-ubsan=yes or
937 --enable-ubsan=auto to configure will enable it. Enabling this can
938 cause a performance penalty. The undefined behavior sanitizer was
939 first introduced in GCC 4.9.
941 *** Changes in GDB 8.2
943 * The 'set disassembler-options' command now supports specifying options
946 * The 'symbol-file' command now accepts an '-o' option to add a relative
947 offset to all sections.
949 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
950 a relative offset to all sections, but it allows to override the load
951 address of individual sections using '-s'.
953 * The 'add-symbol-file' command no longer requires the second argument
954 (address of the text section).
956 * The endianness used with the 'set endian auto' mode in the absence of
957 an executable selected for debugging is now the last endianness chosen
958 either by one of the 'set endian big' and 'set endian little' commands
959 or by inferring from the last executable used, rather than the startup
962 * The pager now allows a "c" response, meaning to disable the pager
963 for the rest of the current command.
965 * The commands 'info variables/functions/types' now show the source line
966 numbers of symbol definitions when available.
968 * 'info proc' now works on running processes on FreeBSD systems and core
969 files created on FreeBSD systems.
971 * C expressions can now use _Alignof, and C++ expressions can now use
974 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
975 the vector length while the process is running.
981 Control display of debugging info regarding the FreeBSD native target.
983 set|show varsize-limit
984 This new setting allows the user to control the maximum size of Ada
985 objects being printed when those objects have a variable type,
986 instead of that maximum size being hardcoded to 65536 bytes.
988 set|show record btrace cpu
989 Controls the processor to be used for enabling errata workarounds for
992 maint check libthread-db
993 Run integrity checks on the current inferior's thread debugging
996 maint set check-libthread-db (on|off)
997 maint show check-libthread-db
998 Control whether to run integrity checks on inferior specific thread
999 debugging libraries as they are loaded. The default is not to
1000 perform such checks.
1004 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1006 ** The commands attached to a breakpoint can be set by assigning to
1007 the breakpoint's "commands" field.
1009 ** gdb.execute can now execute multi-line gdb commands.
1011 ** The new functions gdb.convenience_variable and
1012 gdb.set_convenience_variable can be used to get and set the value
1013 of convenience variables.
1015 ** A gdb.Parameter will no longer print the "set" help text on an
1016 ordinary "set"; instead by default a "set" will be silent unless
1017 the get_set_string method returns a non-empty string.
1021 RiscV ELF riscv*-*-elf
1023 * Removed targets and native configurations
1025 m88k running OpenBSD m88*-*-openbsd*
1026 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1027 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1028 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1030 * Aarch64/Linux hardware watchpoints improvements
1032 Hardware watchpoints on unaligned addresses are now properly
1033 supported when running Linux kernel 4.10 or higher: read and access
1034 watchpoints are no longer spuriously missed, and all watchpoints
1035 lengths between 1 and 8 bytes are supported. On older kernels,
1036 watchpoints set on unaligned addresses are no longer missed, with
1037 the tradeoff that there is a possibility of false hits being
1042 --enable-codesign=CERT
1043 This can be used to invoke "codesign -s CERT" after building gdb.
1044 This option is useful on macOS, where code signing is required for
1045 gdb to work properly.
1047 --disable-gdbcli has been removed
1048 This is now silently accepted, but does nothing.
1050 *** Changes in GDB 8.1
1052 * GDB now supports dynamically creating arbitrary register groups specified
1053 in XML target descriptions. This allows for finer grain grouping of
1054 registers on systems with a large amount of registers.
1056 * The 'ptype' command now accepts a '/o' flag, which prints the
1057 offsets and sizes of fields in a struct, like the pahole(1) tool.
1059 * New "--readnever" command line option instructs GDB to not read each
1060 symbol file's symbolic debug information. This makes startup faster
1061 but at the expense of not being able to perform symbolic debugging.
1062 This option is intended for use cases where symbolic debugging will
1063 not be used, e.g., when you only need to dump the debuggee's core.
1065 * GDB now uses the GNU MPFR library, if available, to emulate target
1066 floating-point arithmetic during expression evaluation when the target
1067 uses different floating-point formats than the host. At least version
1068 3.1 of GNU MPFR is required.
1070 * GDB now supports access to the guarded-storage-control registers and the
1071 software-based guarded-storage broadcast control registers on IBM z14.
1073 * On Unix systems, GDB now supports transmitting environment variables
1074 that are to be set or unset to GDBserver. These variables will
1075 affect the environment to be passed to the remote inferior.
1077 To inform GDB of environment variables that are to be transmitted to
1078 GDBserver, use the "set environment" command. Only user set
1079 environment variables are sent to GDBserver.
1081 To inform GDB of environment variables that are to be unset before
1082 the remote inferior is started by the GDBserver, use the "unset
1083 environment" command.
1085 * Completion improvements
1087 ** GDB can now complete function parameters in linespecs and
1088 explicit locations without quoting. When setting breakpoints,
1089 quoting around functions names to help with TAB-completion is
1090 generally no longer necessary. For example, this now completes
1093 (gdb) b function(in[TAB]
1094 (gdb) b function(int)
1096 Related, GDB is no longer confused with completing functions in
1097 C++ anonymous namespaces:
1100 (gdb) b (anonymous namespace)::[TAB][TAB]
1101 (anonymous namespace)::a_function()
1102 (anonymous namespace)::b_function()
1104 ** GDB now has much improved linespec and explicit locations TAB
1105 completion support, that better understands what you're
1106 completing and offers better suggestions. For example, GDB no
1107 longer offers data symbols as possible completions when you're
1108 setting a breakpoint.
1110 ** GDB now TAB-completes label symbol names.
1112 ** The "complete" command now mimics TAB completion accurately.
1114 * New command line options (gcore)
1117 Dump all memory mappings.
1119 * Breakpoints on C++ functions are now set on all scopes by default
1121 By default, breakpoints on functions/methods are now interpreted as
1122 specifying all functions with the given name ignoring missing
1123 leading scopes (namespaces and classes).
1125 For example, assuming a C++ program with symbols named:
1130 both commands "break func()" and "break B::func()" set a breakpoint
1133 You can use the new flag "-qualified" to override this. This makes
1134 GDB interpret the specified function name as a complete
1135 fully-qualified name instead. For example, using the same C++
1136 program, the "break -q B::func" command sets a breakpoint on
1137 "B::func", only. A parameter has been added to the Python
1138 gdb.Breakpoint constructor to achieve the same result when creating
1139 a breakpoint from Python.
1141 * Breakpoints on functions marked with C++ ABI tags
1143 GDB can now set breakpoints on functions marked with C++ ABI tags
1144 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1145 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1147 Functions with a C++11 abi tag are demangled/displayed like this:
1149 function[abi:cxx11](int)
1152 You can now set a breakpoint on such functions simply as if they had
1155 (gdb) b function(int)
1157 Or if you need to disambiguate between tags, like:
1159 (gdb) b function[abi:other_tag](int)
1161 Tab completion was adjusted accordingly as well.
1165 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1166 gdb.new_thread are emitted. See the manual for further
1167 description of these.
1169 ** A new function, "gdb.rbreak" has been added to the Python API.
1170 This function allows the setting of a large number of breakpoints
1171 via a regex pattern in Python. See the manual for further details.
1173 ** Python breakpoints can now accept explicit locations. See the
1174 manual for a further description of this feature.
1177 * New features in the GDB remote stub, GDBserver
1179 ** GDBserver is now able to start inferior processes with a
1180 specified initial working directory.
1182 The user can set the desired working directory to be used from
1183 GDB using the new "set cwd" command.
1185 ** New "--selftest" command line option runs some GDBserver self
1186 tests. These self tests are disabled in releases.
1188 ** On Unix systems, GDBserver now does globbing expansion and variable
1189 substitution in inferior command line arguments.
1191 This is done by starting inferiors using a shell, like GDB does.
1192 See "set startup-with-shell" in the user manual for how to disable
1193 this from GDB when using "target extended-remote". When using
1194 "target remote", you can disable the startup with shell by using the
1195 new "--no-startup-with-shell" GDBserver command line option.
1197 ** On Unix systems, GDBserver now supports receiving environment
1198 variables that are to be set or unset from GDB. These variables
1199 will affect the environment to be passed to the inferior.
1201 * When catching an Ada exception raised with a message, GDB now prints
1202 the message in the catchpoint hit notification. In GDB/MI mode, that
1203 information is provided as an extra field named "exception-message"
1204 in the *stopped notification.
1206 * Trait objects can now be inspected When debugging Rust code. This
1207 requires compiler support which will appear in Rust 1.24.
1209 * New remote packets
1211 QEnvironmentHexEncoded
1212 Inform GDBserver of an environment variable that is to be passed to
1213 the inferior when starting it.
1216 Inform GDBserver of an environment variable that is to be unset
1217 before starting the remote inferior.
1220 Inform GDBserver that the environment should be reset (i.e.,
1221 user-set environment variables should be unset).
1224 Indicates whether the inferior must be started with a shell or not.
1227 Tell GDBserver that the inferior to be started should use a specific
1230 * The "maintenance print c-tdesc" command now takes an optional
1231 argument which is the file name of XML target description.
1233 * The "maintenance selftest" command now takes an optional argument to
1234 filter the tests to be run.
1236 * The "enable", and "disable" commands now accept a range of
1237 breakpoint locations, e.g. "enable 1.3-5".
1242 Set and show the current working directory for the inferior.
1244 set|show compile-gcc
1245 Set and show compilation command used for compiling and injecting code
1246 with the 'compile' commands.
1248 set debug separate-debug-file
1249 show debug separate-debug-file
1250 Control the display of debug output about separate debug file search.
1252 set dump-excluded-mappings
1253 show dump-excluded-mappings
1254 Control whether mappings marked with the VM_DONTDUMP flag should be
1255 dumped when generating a core file.
1257 maint info selftests
1258 List the registered selftests.
1261 Start the debugged program stopping at the first instruction.
1264 Control display of debugging messages related to OpenRISC targets.
1266 set|show print type nested-type-limit
1267 Set and show the limit of nesting level for nested types that the
1268 type printer will show.
1270 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1273 * Safer/improved support for debugging with no debug info
1275 GDB no longer assumes functions with no debug information return
1278 This means that GDB now refuses to call such functions unless you
1279 tell it the function's type, by either casting the call to the
1280 declared return type, or by casting the function to a function
1281 pointer of the right type, and calling that:
1283 (gdb) p getenv ("PATH")
1284 'getenv' has unknown return type; cast the call to its declared return type
1285 (gdb) p (char *) getenv ("PATH")
1286 $1 = 0x7fffffffe "/usr/local/bin:/"...
1287 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1288 $2 = 0x7fffffffe "/usr/local/bin:/"...
1290 Similarly, GDB no longer assumes that global variables with no debug
1291 info have type 'int', and refuses to print the variable's value
1292 unless you tell it the variable's type:
1295 'var' has unknown type; cast it to its declared type
1299 * New native configurations
1301 FreeBSD/aarch64 aarch64*-*-freebsd*
1302 FreeBSD/arm arm*-*-freebsd*
1306 FreeBSD/aarch64 aarch64*-*-freebsd*
1307 FreeBSD/arm arm*-*-freebsd*
1308 OpenRISC ELF or1k*-*-elf
1310 * Removed targets and native configurations
1312 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1314 *** Changes in GDB 8.0
1316 * GDB now supports access to the PKU register on GNU/Linux. The register is
1317 added by the Memory Protection Keys for Userspace feature which will be
1318 available in future Intel CPUs.
1320 * GDB now supports C++11 rvalue references.
1324 ** New functions to start, stop and access a running btrace recording.
1325 ** Rvalue references are now supported in gdb.Type.
1327 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1330 * Building GDB and GDBserver now requires a C++11 compiler.
1332 For example, GCC 4.8 or later.
1334 It is no longer possible to build GDB or GDBserver with a C
1335 compiler. The --disable-build-with-cxx configure option has been
1338 * Building GDB and GDBserver now requires GNU make >= 3.81.
1340 It is no longer supported to build GDB or GDBserver with another
1341 implementation of the make program or an earlier version of GNU make.
1343 * Native debugging on MS-Windows supports command-line redirection
1345 Command-line arguments used for starting programs on MS-Windows can
1346 now include redirection symbols supported by native Windows shells,
1347 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1348 as "run", "start", and "set args", as well as the corresponding MI
1351 * Support for thread names on MS-Windows.
1353 GDB now catches and handles the special exception that programs
1354 running on MS-Windows use to assign names to threads in the
1357 * Support for Java programs compiled with gcj has been removed.
1359 * User commands now accept an unlimited number of arguments.
1360 Previously, only up to 10 was accepted.
1362 * The "eval" command now expands user-defined command arguments.
1364 This makes it easier to process a variable number of arguments:
1369 eval "print $arg%d", $i
1374 * Target descriptions can now describe registers for sparc32 and sparc64.
1376 * GDB now supports DWARF version 5 (debug information format).
1377 Its .debug_names index is not yet supported.
1379 * New native configurations
1381 FreeBSD/mips mips*-*-freebsd
1385 Synopsys ARC arc*-*-elf32
1386 FreeBSD/mips mips*-*-freebsd
1388 * Removed targets and native configurations
1390 Alpha running FreeBSD alpha*-*-freebsd*
1391 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1396 Erases all the flash memory regions reported by the target.
1398 maint print arc arc-instruction address
1399 Print internal disassembler information about instruction at a given address.
1403 set disassembler-options
1404 show disassembler-options
1405 Controls the passing of target specific information to the disassembler.
1406 If it is necessary to specify more than one disassembler option then
1407 multiple options can be placed together into a comma separated list.
1408 The default value is the empty string. Currently, the only supported
1409 targets are ARM, PowerPC and S/390.
1414 Erases all the flash memory regions reported by the target. This is
1415 equivalent to the CLI command flash-erase.
1417 -file-list-shared-libraries
1418 List the shared libraries in the program. This is
1419 equivalent to the CLI command "info shared".
1422 Catchpoints stopping the program when Ada exceptions are
1423 handled. This is equivalent to the CLI command "catch handlers".
1425 *** Changes in GDB 7.12
1427 * GDB and GDBserver now build with a C++ compiler by default.
1429 The --enable-build-with-cxx configure option is now enabled by
1430 default. One must now explicitly configure with
1431 --disable-build-with-cxx in order to build with a C compiler. This
1432 option will be removed in a future release.
1434 * GDBserver now supports recording btrace without maintaining an active
1437 * GDB now supports a negative repeat count in the 'x' command to examine
1438 memory backward from the given address. For example:
1441 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1442 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1443 (gdb) x/-5i 0x0000000000400580
1444 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1445 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1446 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1447 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1448 0x40057b <main(int, char**)+25>:
1449 callq 0x400536 <Func1(int, char const*)>
1451 * Fortran: Support structures with fields of dynamic types and
1452 arrays of dynamic types.
1454 * The symbol dumping maintenance commands have new syntax.
1455 maint print symbols [-pc address] [--] [filename]
1456 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1457 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1458 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1459 maint print msymbols [-objfile objfile] [--] [filename]
1461 * GDB now supports multibit bitfields and enums in target register
1464 * New Python-based convenience function $_as_string(val), which returns
1465 the textual representation of a value. This function is especially
1466 useful to obtain the text label of an enum value.
1468 * Intel MPX bound violation handling.
1470 Segmentation faults caused by a Intel MPX boundary violation
1471 now display the kind of violation (upper or lower), the memory
1472 address accessed and the memory bounds, along with the usual
1473 signal received and code location.
1477 Program received signal SIGSEGV, Segmentation fault
1478 Upper bound violation while accessing address 0x7fffffffc3b3
1479 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1480 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1482 * Rust language support.
1483 GDB now supports debugging programs written in the Rust programming
1484 language. See https://www.rust-lang.org/ for more information about
1487 * Support for running interpreters on specified input/output devices
1489 GDB now supports a new mechanism that allows frontends to provide
1490 fully featured GDB console views, as a better alternative to
1491 building such views on top of the "-interpreter-exec console"
1492 command. See the new "new-ui" command below. With that command,
1493 frontends can now start GDB in the traditional command-line mode
1494 running in an embedded terminal emulator widget, and create a
1495 separate MI interpreter running on a specified i/o device. In this
1496 way, GDB handles line editing, history, tab completion, etc. in the
1497 console all by itself, and the GUI uses the separate MI interpreter
1498 for its own control and synchronization, invisible to the command
1501 * The "catch syscall" command catches groups of related syscalls.
1503 The "catch syscall" command now supports catching a group of related
1504 syscalls using the 'group:' or 'g:' prefix.
1509 skip -gfile file-glob-pattern
1510 skip -function function
1511 skip -rfunction regular-expression
1512 A generalized form of the skip command, with new support for
1513 glob-style file names and regular expressions for function names.
1514 Additionally, a file spec and a function spec may now be combined.
1516 maint info line-table REGEXP
1517 Display the contents of GDB's internal line table data structure.
1520 Run any GDB unit tests that were compiled in.
1523 Start a new user interface instance running INTERP as interpreter,
1524 using the TTY file for input/output.
1528 ** gdb.Breakpoint objects have a new attribute "pending", which
1529 indicates whether the breakpoint is pending.
1530 ** Three new breakpoint-related events have been added:
1531 gdb.breakpoint_created, gdb.breakpoint_modified, and
1532 gdb.breakpoint_deleted.
1534 signal-event EVENTID
1535 Signal ("set") the given MS-Windows event object. This is used in
1536 conjunction with the Windows JIT debugging (AeDebug) support, where
1537 the OS suspends a crashing process until a debugger can attach to
1538 it. Resuming the crashing process, in order to debug it, is done by
1539 signalling an event.
1541 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1542 was added in GDBserver, including JIT compiling fast tracepoint's
1543 conditional expression bytecode into native code.
1545 * Support for various remote target protocols and ROM monitors has
1548 target m32rsdi Remote M32R debugging over SDI
1549 target mips MIPS remote debugging protocol
1550 target pmon PMON ROM monitor
1551 target ddb NEC's DDB variant of PMON for Vr4300
1552 target rockhopper NEC RockHopper variant of PMON
1553 target lsi LSI variant of PMO
1555 * Support for tracepoints and fast tracepoints on powerpc-linux,
1556 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1557 including JIT compiling fast tracepoint's conditional expression
1558 bytecode into native code.
1560 * MI async record =record-started now includes the method and format used for
1561 recording. For example:
1563 =record-started,thread-group="i1",method="btrace",format="bts"
1565 * MI async record =thread-selected now includes the frame field. For example:
1567 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1571 Andes NDS32 nds32*-*-elf
1573 *** Changes in GDB 7.11
1575 * GDB now supports debugging kernel-based threads on FreeBSD.
1577 * Per-inferior thread numbers
1579 Thread numbers are now per inferior instead of global. If you're
1580 debugging multiple inferiors, GDB displays thread IDs using a
1581 qualified INF_NUM.THR_NUM form. For example:
1585 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1586 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1587 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1588 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1590 As consequence, thread numbers as visible in the $_thread
1591 convenience variable and in Python's InferiorThread.num attribute
1592 are no longer unique between inferiors.
1594 GDB now maintains a second thread ID per thread, referred to as the
1595 global thread ID, which is the new equivalent of thread numbers in
1596 previous releases. See also $_gthread below.
1598 For backwards compatibility, MI's thread IDs always refer to global
1601 * Commands that accept thread IDs now accept the qualified
1602 INF_NUM.THR_NUM form as well. For example:
1605 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1608 * In commands that accept a list of thread IDs, you can now refer to
1609 all threads of an inferior using a star wildcard. GDB accepts
1610 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1611 refer to all threads of the current inferior. For example, "info
1614 * You can use "info threads -gid" to display the global thread ID of
1617 * The new convenience variable $_gthread holds the global number of
1620 * The new convenience variable $_inferior holds the number of the
1623 * GDB now displays the ID and name of the thread that hit a breakpoint
1624 or received a signal, if your program is multi-threaded. For
1627 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1628 Thread 1 "main" received signal SIGINT, Interrupt.
1630 * Record btrace now supports non-stop mode.
1632 * Support for tracepoints on aarch64-linux was added in GDBserver.
1634 * The 'record instruction-history' command now indicates speculative execution
1635 when using the Intel Processor Trace recording format.
1637 * GDB now allows users to specify explicit locations, bypassing
1638 the linespec parser. This feature is also available to GDB/MI
1641 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1642 GDB now is able to debug both AArch64 applications and ARM applications
1645 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1646 including JIT compiling fast tracepoint's conditional expression bytecode
1649 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1651 * "info threads", "info inferiors", "info display", "info checkpoints"
1652 and "maint info program-spaces" now list the corresponding items in
1653 ascending ID order, for consistency with all other "info" commands.
1655 * In Ada, the overloads selection menu has been enhanced to display the
1656 parameter types and the return types for the matching overloaded subprograms.
1660 maint set target-non-stop (on|off|auto)
1661 maint show target-non-stop
1662 Control whether GDB targets always operate in non-stop mode even if
1663 "set non-stop" is "off". The default is "auto", meaning non-stop
1664 mode is enabled if supported by the target.
1666 maint set bfd-sharing
1667 maint show bfd-sharing
1668 Control the reuse of bfd objects.
1671 show debug bfd-cache
1672 Control display of debugging info regarding bfd caching.
1676 Control display of debugging info regarding FreeBSD threads.
1678 set remote multiprocess-extensions-packet
1679 show remote multiprocess-extensions-packet
1680 Set/show the use of the remote protocol multiprocess extensions.
1682 set remote thread-events
1683 show remote thread-events
1684 Set/show the use of thread create/exit events.
1686 set ada print-signatures on|off
1687 show ada print-signatures"
1688 Control whether parameter types and return types are displayed in overloads
1689 selection menus. It is activated (@code{on}) by default.
1693 Controls the maximum size of memory, in bytes, that GDB will
1694 allocate for value contents. Prevents incorrect programs from
1695 causing GDB to allocate overly large buffers. Default is 64k.
1697 * The "disassemble" command accepts a new modifier: /s.
1698 It prints mixed source+disassembly like /m with two differences:
1699 - disassembled instructions are now printed in program order, and
1700 - and source for all relevant files is now printed.
1701 The "/m" option is now considered deprecated: its "source-centric"
1702 output hasn't proved useful in practice.
1704 * The "record instruction-history" command accepts a new modifier: /s.
1705 It behaves exactly like /m and prints mixed source+disassembly.
1707 * The "set scheduler-locking" command supports a new mode "replay".
1708 It behaves like "off" in record mode and like "on" in replay mode.
1710 * Support for various ROM monitors has been removed:
1712 target dbug dBUG ROM monitor for Motorola ColdFire
1713 target picobug Motorola picobug monitor
1714 target dink32 DINK32 ROM monitor for PowerPC
1715 target m32r Renesas M32R/D ROM monitor
1716 target mon2000 mon2000 ROM monitor
1717 target ppcbug PPCBUG ROM monitor for PowerPC
1719 * Support for reading/writing memory and extracting values on architectures
1720 whose memory is addressable in units of any integral multiple of 8 bits.
1723 Allows to break when an Ada exception is handled.
1725 * New remote packets
1728 Indicates that an exec system call was executed.
1730 exec-events feature in qSupported
1731 The qSupported packet allows GDB to request support for exec
1732 events using the new 'gdbfeature' exec-event, and the qSupported
1733 response can contain the corresponding 'stubfeature'. Set and
1734 show commands can be used to display whether these features are enabled.
1737 Equivalent to interrupting with the ^C character, but works in
1740 thread created stop reason (T05 create:...)
1741 Indicates that the thread was just created and is stopped at entry.
1743 thread exit stop reply (w exitcode;tid)
1744 Indicates that the thread has terminated.
1747 Enables/disables thread create and exit event reporting. For
1748 example, this is used in non-stop mode when GDB stops a set of
1749 threads and synchronously waits for the their corresponding stop
1750 replies. Without exit events, if one of the threads exits, GDB
1751 would hang forever not knowing that it should no longer expect a
1752 stop for that same thread.
1755 Indicates that there are no resumed threads left in the target (all
1756 threads are stopped). The remote stub reports support for this stop
1757 reply to GDB's qSupported query.
1760 Enables/disables catching syscalls from the inferior process.
1761 The remote stub reports support for this packet to GDB's qSupported query.
1763 syscall_entry stop reason
1764 Indicates that a syscall was just called.
1766 syscall_return stop reason
1767 Indicates that a syscall just returned.
1769 * Extended-remote exec events
1771 ** GDB now has support for exec events on extended-remote Linux targets.
1772 For such targets with Linux kernels 2.5.46 and later, this enables
1773 follow-exec-mode and exec catchpoints.
1775 set remote exec-event-feature-packet
1776 show remote exec-event-feature-packet
1777 Set/show the use of the remote exec event feature.
1779 * Thread names in remote protocol
1781 The reply to qXfer:threads:read may now include a name attribute for each
1784 * Target remote mode fork and exec events
1786 ** GDB now has support for fork and exec events on target remote mode
1787 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1788 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1789 fork and exec catchpoints.
1791 * Remote syscall events
1793 ** GDB now has support for catch syscall on remote Linux targets,
1794 currently enabled on x86/x86_64 architectures.
1796 set remote catch-syscall-packet
1797 show remote catch-syscall-packet
1798 Set/show the use of the remote catch syscall feature.
1802 ** The -var-set-format command now accepts the zero-hexadecimal
1803 format. It outputs data in hexadecimal format with zero-padding on the
1808 ** gdb.InferiorThread objects have a new attribute "global_num",
1809 which refers to the thread's global thread ID. The existing
1810 "num" attribute now refers to the thread's per-inferior number.
1811 See "Per-inferior thread numbers" above.
1812 ** gdb.InferiorThread objects have a new attribute "inferior", which
1813 is the Inferior object the thread belongs to.
1815 *** Changes in GDB 7.10
1817 * Support for process record-replay and reverse debugging on aarch64*-linux*
1818 targets has been added. GDB now supports recording of A64 instruction set
1819 including advance SIMD instructions.
1821 * Support for Sun's version of the "stabs" debug file format has been removed.
1823 * GDB now honors the content of the file /proc/PID/coredump_filter
1824 (PID is the process ID) on GNU/Linux systems. This file can be used
1825 to specify the types of memory mappings that will be included in a
1826 corefile. For more information, please refer to the manual page of
1827 "core(5)". GDB also has a new command: "set use-coredump-filter
1828 on|off". It allows to set whether GDB will read the content of the
1829 /proc/PID/coredump_filter file when generating a corefile.
1831 * The "info os" command on GNU/Linux can now display information on
1833 "info os cpus" Listing of all cpus/cores on the system
1835 * GDB has two new commands: "set serial parity odd|even|none" and
1836 "show serial parity". These allows to set or show parity for the
1839 * The "info source" command now displays the producer string if it was
1840 present in the debug info. This typically includes the compiler version
1841 and may include things like its command line arguments.
1843 * The "info dll", an alias of the "info sharedlibrary" command,
1844 is now available on all platforms.
1846 * Directory names supplied to the "set sysroot" commands may be
1847 prefixed with "target:" to tell GDB to access shared libraries from
1848 the target system, be it local or remote. This replaces the prefix
1849 "remote:". The default sysroot has been changed from "" to
1850 "target:". "remote:" is automatically converted to "target:" for
1851 backward compatibility.
1853 * The system root specified by "set sysroot" will be prepended to the
1854 filename of the main executable (if reported to GDB as absolute by
1855 the operating system) when starting processes remotely, and when
1856 attaching to already-running local or remote processes.
1858 * GDB now supports automatic location and retrieval of executable
1859 files from remote targets. Remote debugging can now be initiated
1860 using only a "target remote" or "target extended-remote" command
1861 (no "set sysroot" or "file" commands are required). See "New remote
1864 * The "dump" command now supports verilog hex format.
1866 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1868 * On GNU/Linux, GDB and gdbserver are now able to access executable
1869 and shared library files without a "set sysroot" command when
1870 attaching to processes running in different mount namespaces from
1871 the debugger. This makes it possible to attach to processes in
1872 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1873 See "New remote packets" below.
1875 * The "tui reg" command now provides completion for all of the
1876 available register groups, including target specific groups.
1878 * The HISTSIZE environment variable is no longer read when determining
1879 the size of GDB's command history. GDB now instead reads the dedicated
1880 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1881 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1886 ** Memory ports can now be unbuffered.
1890 ** gdb.Objfile objects have a new attribute "username",
1891 which is the name of the objfile as specified by the user,
1892 without, for example, resolving symlinks.
1893 ** You can now write frame unwinders in Python.
1894 ** gdb.Type objects have a new method "optimized_out",
1895 returning optimized out gdb.Value instance of this type.
1896 ** gdb.Value objects have new methods "reference_value" and
1897 "const_value" which return a reference to the value and a
1898 "const" version of the value respectively.
1902 maint print symbol-cache
1903 Print the contents of the symbol cache.
1905 maint print symbol-cache-statistics
1906 Print statistics of symbol cache usage.
1908 maint flush-symbol-cache
1909 Flush the contents of the symbol cache.
1913 Start branch trace recording using Branch Trace Store (BTS) format.
1916 Evaluate expression by using the compiler and print result.
1920 Explicit commands for enabling and disabling tui mode.
1923 set mpx bound on i386 and amd64
1924 Support for bound table investigation on Intel MPX enabled applications.
1928 Start branch trace recording using Intel Processor Trace format.
1931 Print information about branch tracing internals.
1933 maint btrace packet-history
1934 Print the raw branch tracing data.
1936 maint btrace clear-packet-history
1937 Discard the stored raw branch tracing data.
1940 Discard all branch tracing data. It will be fetched and processed
1941 anew by the next "record" command.
1946 Renamed from "set debug dwarf2-die".
1947 show debug dwarf-die
1948 Renamed from "show debug dwarf2-die".
1950 set debug dwarf-read
1951 Renamed from "set debug dwarf2-read".
1952 show debug dwarf-read
1953 Renamed from "show debug dwarf2-read".
1955 maint set dwarf always-disassemble
1956 Renamed from "maint set dwarf2 always-disassemble".
1957 maint show dwarf always-disassemble
1958 Renamed from "maint show dwarf2 always-disassemble".
1960 maint set dwarf max-cache-age
1961 Renamed from "maint set dwarf2 max-cache-age".
1962 maint show dwarf max-cache-age
1963 Renamed from "maint show dwarf2 max-cache-age".
1965 set debug dwarf-line
1966 show debug dwarf-line
1967 Control display of debugging info regarding DWARF line processing.
1970 show max-completions
1971 Set the maximum number of candidates to be considered during
1972 completion. The default value is 200. This limit allows GDB
1973 to avoid generating large completion lists, the computation of
1974 which can cause the debugger to become temporarily unresponsive.
1976 set history remove-duplicates
1977 show history remove-duplicates
1978 Control the removal of duplicate history entries.
1980 maint set symbol-cache-size
1981 maint show symbol-cache-size
1982 Control the size of the symbol cache.
1984 set|show record btrace bts buffer-size
1985 Set and show the size of the ring buffer used for branch tracing in
1987 The obtained size may differ from the requested size. Use "info
1988 record" to see the obtained buffer size.
1990 set debug linux-namespaces
1991 show debug linux-namespaces
1992 Control display of debugging info regarding Linux namespaces.
1994 set|show record btrace pt buffer-size
1995 Set and show the size of the ring buffer used for branch tracing in
1996 Intel Processor Trace format.
1997 The obtained size may differ from the requested size. Use "info
1998 record" to see the obtained buffer size.
2000 maint set|show btrace pt skip-pad
2001 Set and show whether PAD packets are skipped when computing the
2004 * The command 'thread apply all' can now support new option '-ascending'
2005 to call its specified command for all threads in ascending order.
2007 * Python/Guile scripting
2009 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2010 special section named `.debug_gdb_scripts'.
2012 * New remote packets
2014 qXfer:btrace-conf:read
2015 Return the branch trace configuration for the current thread.
2017 Qbtrace-conf:bts:size
2018 Set the requested ring buffer size for branch tracing in BTS format.
2021 Enable Intel Processor Trace-based branch tracing for the current
2022 process. The remote stub reports support for this packet to GDB's
2025 Qbtrace-conf:pt:size
2026 Set the requested ring buffer size for branch tracing in Intel Processor
2030 Indicates a memory breakpoint instruction was executed, irrespective
2031 of whether it was GDB that planted the breakpoint or the breakpoint
2032 is hardcoded in the program. This is required for correct non-stop
2036 Indicates the target stopped for a hardware breakpoint. This is
2037 required for correct non-stop mode operation.
2040 Return information about files on the remote system.
2042 qXfer:exec-file:read
2043 Return the full absolute name of the file that was executed to
2044 create a process running on the remote system.
2047 Select the filesystem on which vFile: operations with filename
2048 arguments will operate. This is required for GDB to be able to
2049 access files on remote targets where the remote stub does not
2050 share a common filesystem with the inferior(s).
2053 Indicates that a fork system call was executed.
2056 Indicates that a vfork system call was executed.
2058 vforkdone stop reason
2059 Indicates that a vfork child of the specified process has executed
2060 an exec or exit, allowing the vfork parent to resume execution.
2062 fork-events and vfork-events features in qSupported
2063 The qSupported packet allows GDB to request support for fork and
2064 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2065 and the qSupported response can contain the corresponding
2066 'stubfeatures'. Set and show commands can be used to display
2067 whether these features are enabled.
2069 * Extended-remote fork events
2071 ** GDB now has support for fork events on extended-remote Linux
2072 targets. For targets with Linux kernels 2.5.60 and later, this
2073 enables follow-fork-mode and detach-on-fork for both fork and
2074 vfork, as well as fork and vfork catchpoints.
2076 * The info record command now shows the recording format and the
2077 branch tracing configuration for the current thread when using
2078 the btrace record target.
2079 For the BTS format, it shows the ring buffer size.
2081 * GDB now has support for DTrace USDT (Userland Static Defined
2082 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2084 * GDB now supports access to vector registers on S/390 GNU/Linux
2087 * Removed command line options
2089 -xdb HP-UX XDB compatibility mode.
2091 * Removed targets and native configurations
2093 HP/PA running HP-UX hppa*-*-hpux*
2094 Itanium running HP-UX ia64-*-hpux*
2096 * New configure options
2099 This configure option allows the user to build GDB with support for
2100 Intel Processor Trace (default: auto). This requires libipt.
2102 --with-libipt-prefix=PATH
2103 Specify the path to the version of libipt that GDB should use.
2104 $PATH/include should contain the intel-pt.h header and
2105 $PATH/lib should contain the libipt.so library.
2107 *** Changes in GDB 7.9.1
2111 ** Xmethods can now specify a result type.
2113 *** Changes in GDB 7.9
2115 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2119 ** You can now access frame registers from Python scripts.
2120 ** New attribute 'producer' for gdb.Symtab objects.
2121 ** gdb.Objfile objects have a new attribute "progspace",
2122 which is the gdb.Progspace object of the containing program space.
2123 ** gdb.Objfile objects have a new attribute "owner".
2124 ** gdb.Objfile objects have a new attribute "build_id",
2125 which is the build ID generated when the file was built.
2126 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2127 ** A new event "gdb.clear_objfiles" has been added, triggered when
2128 selecting a new file to debug.
2129 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2130 ** New function gdb.lookup_objfile.
2132 New events which are triggered when GDB modifies the state of the
2135 ** gdb.events.inferior_call_pre: Function call is about to be made.
2136 ** gdb.events.inferior_call_post: Function call has just been made.
2137 ** gdb.events.memory_changed: A memory location has been altered.
2138 ** gdb.events.register_changed: A register has been altered.
2140 * New Python-based convenience functions:
2142 ** $_caller_is(name [, number_of_frames])
2143 ** $_caller_matches(regexp [, number_of_frames])
2144 ** $_any_caller_is(name [, number_of_frames])
2145 ** $_any_caller_matches(regexp [, number_of_frames])
2147 * GDB now supports the compilation and injection of source code into
2148 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2149 to compile the source code to object code, and if successful, inject
2150 and execute that code within the current context of the inferior.
2151 Currently the C language is supported. The commands used to
2152 interface with this new feature are:
2154 compile code [-raw|-r] [--] [source code]
2155 compile file [-raw|-r] filename
2159 demangle [-l language] [--] name
2160 Demangle "name" in the specified language, or the current language
2161 if elided. This command is renamed from the "maint demangle" command.
2162 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2163 as "maint demangler-warning".
2165 queue-signal signal-name-or-number
2166 Queue a signal to be delivered to the thread when it is resumed.
2168 add-auto-load-scripts-directory directory
2169 Add entries to the list of directories from which to load auto-loaded
2172 maint print user-registers
2173 List all currently available "user" registers.
2175 compile code [-r|-raw] [--] [source code]
2176 Compile, inject, and execute in the inferior the executable object
2177 code produced by compiling the provided source code.
2179 compile file [-r|-raw] filename
2180 Compile and inject into the inferior the executable object code
2181 produced by compiling the source code stored in the filename
2184 * On resume, GDB now always passes the signal the program had stopped
2185 for to the thread the signal was sent to, even if the user changed
2186 threads before resuming. Previously GDB would often (but not
2187 always) deliver the signal to the thread that happens to be current
2190 * Conversely, the "signal" command now consistently delivers the
2191 requested signal to the current thread. GDB now asks for
2192 confirmation if the program had stopped for a signal and the user
2193 switched threads meanwhile.
2195 * "breakpoint always-inserted" modes "off" and "auto" merged.
2197 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2198 won't remove breakpoints from the target until all threads stop,
2199 even in non-stop mode. The "auto" mode has been removed, and "off"
2200 is now the default mode.
2204 set debug symbol-lookup
2205 show debug symbol-lookup
2206 Control display of debugging info regarding symbol lookup.
2210 ** The -list-thread-groups command outputs an exit-code field for
2211 inferiors that have exited.
2215 MIPS SDE mips*-sde*-elf*
2219 Support for these obsolete configurations has been removed.
2221 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2222 SGI Irix-5.x mips-*-irix5*
2223 SGI Irix-6.x mips-*-irix6*
2224 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2225 VAX running Ultrix vax-*-ultrix*
2227 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2228 and "assf"), have been removed. Use the "sharedlibrary" command, or
2229 its alias "share", instead.
2231 *** Changes in GDB 7.8
2233 * New command line options
2236 This is an alias for the --data-directory option.
2238 * GDB supports printing and modifying of variable length automatic arrays
2239 as specified in ISO C99.
2241 * The ARM simulator now supports instruction level tracing
2242 with or without disassembly.
2246 GDB now has support for scripting using Guile. Whether this is
2247 available is determined at configure time.
2248 Guile version 2.0 or greater is required.
2249 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2251 * New commands (for set/show, see "New options" below)
2255 Invoke CODE by passing it to the Guile interpreter.
2259 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2261 info auto-load guile-scripts [regexp]
2262 Print the list of automatically loaded Guile scripts.
2264 * The source command is now capable of sourcing Guile scripts.
2265 This feature is dependent on the debugger being built with Guile support.
2269 set print symbol-loading (off|brief|full)
2270 show print symbol-loading
2271 Control whether to print informational messages when loading symbol
2272 information for a file. The default is "full", but when debugging
2273 programs with large numbers of shared libraries the amount of output
2274 becomes less useful.
2276 set guile print-stack (none|message|full)
2277 show guile print-stack
2278 Show a stack trace when an error is encountered in a Guile script.
2280 set auto-load guile-scripts (on|off)
2281 show auto-load guile-scripts
2282 Control auto-loading of Guile script files.
2284 maint ada set ignore-descriptive-types (on|off)
2285 maint ada show ignore-descriptive-types
2286 Control whether the debugger should ignore descriptive types in Ada
2287 programs. The default is not to ignore the descriptive types. See
2288 the user manual for more details on descriptive types and the intended
2289 usage of this option.
2291 set auto-connect-native-target
2293 Control whether GDB is allowed to automatically connect to the
2294 native target for the run, attach, etc. commands when not connected
2295 to any target yet. See also "target native" below.
2297 set record btrace replay-memory-access (read-only|read-write)
2298 show record btrace replay-memory-access
2299 Control what memory accesses are allowed during replay.
2301 maint set target-async (on|off)
2302 maint show target-async
2303 This controls whether GDB targets operate in synchronous or
2304 asynchronous mode. Normally the default is asynchronous, if it is
2305 available; but this can be changed to more easily debug problems
2306 occurring only in synchronous mode.
2308 set mi-async (on|off)
2310 Control whether MI asynchronous mode is preferred. This supersedes
2311 "set target-async" of previous GDB versions.
2313 * "set target-async" is deprecated as a CLI option and is now an alias
2314 for "set mi-async" (only puts MI into async mode).
2316 * Background execution commands (e.g., "c&", "s&", etc.) are now
2317 possible ``out of the box'' if the target supports them. Previously
2318 the user would need to explicitly enable the possibility with the
2319 "set target-async on" command.
2321 * New features in the GDB remote stub, GDBserver
2323 ** New option --debug-format=option1[,option2,...] allows one to add
2324 additional text to each output. At present only timestamps
2325 are supported: --debug-format=timestamps.
2326 Timestamps can also be turned on with the
2327 "monitor set debug-format timestamps" command from GDB.
2329 * The 'record instruction-history' command now starts counting instructions
2330 at one. This also affects the instruction ranges reported by the
2331 'record function-call-history' command when given the /i modifier.
2333 * The command 'record function-call-history' supports a new modifier '/c' to
2334 indent the function names based on their call stack depth.
2335 The fields for the '/i' and '/l' modifier have been reordered.
2336 The source line range is now prefixed with 'at'.
2337 The instruction range is now prefixed with 'inst'.
2338 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2339 "record instruction-history" and "list" commands.
2341 * The ranges given as arguments to the 'record function-call-history' and
2342 'record instruction-history' commands are now inclusive.
2344 * The btrace record target now supports the 'record goto' command.
2345 For locations inside the execution trace, the back trace is computed
2346 based on the information stored in the execution trace.
2348 * The btrace record target supports limited reverse execution and replay.
2349 The target does not record data and therefore does not allow reading
2350 memory or registers.
2352 * The "catch syscall" command now works on s390*-linux* targets.
2354 * The "compare-sections" command is no longer specific to target
2355 remote. It now works with all targets.
2357 * All native targets are now consistently called "native".
2358 Consequently, the "target child", "target GNU", "target djgpp",
2359 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2360 commands have been replaced with "target native". The QNX/NTO port
2361 leaves the "procfs" target in place and adds a "native" target for
2362 consistency with other ports. The impact on users should be minimal
2363 as these commands previously either throwed an error, or were
2364 no-ops. The target's name is visible in the output of the following
2365 commands: "help target", "info target", "info files", "maint print
2368 * The "target native" command now connects to the native target. This
2369 can be used to launch native programs even when "set
2370 auto-connect-native-target" is set to off.
2372 * GDB now supports access to Intel MPX registers on GNU/Linux.
2374 * Support for Intel AVX-512 registers on GNU/Linux.
2375 Support displaying and modifying Intel AVX-512 registers
2376 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2378 * New remote packets
2380 qXfer:btrace:read's annex
2381 The qXfer:btrace:read packet supports a new annex 'delta' to read
2382 branch trace incrementally.
2386 ** Valid Python operations on gdb.Value objects representing
2387 structs/classes invoke the corresponding overloaded operators if
2389 ** New `Xmethods' feature in the Python API. Xmethods are
2390 additional methods or replacements for existing methods of a C++
2391 class. This feature is useful for those cases where a method
2392 defined in C++ source code could be inlined or optimized out by
2393 the compiler, making it unavailable to GDB.
2396 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2398 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2399 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2400 its alias "share", instead.
2402 * The commands "set remotebaud" and "show remotebaud" are no longer
2403 supported. Use "set serial baud" and "show serial baud" (respectively)
2408 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2409 target-async". The latter is left as a deprecated alias of the
2410 former for backward compatibility. If the target supports it,
2411 CLI background execution commands are now always possible by
2412 default, independently of whether the frontend stated a
2413 preference for asynchronous execution with "-gdb-set mi-async".
2414 Previously "-gdb-set target-async off" affected both MI execution
2415 commands and CLI execution commands.
2417 *** Changes in GDB 7.7
2419 * Improved support for process record-replay and reverse debugging on
2420 arm*-linux* targets. Support for thumb32 and syscall instruction
2421 recording has been added.
2423 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2425 * GDB now supports Fission DWP file format version 2.
2426 http://gcc.gnu.org/wiki/DebugFission
2428 * New convenience function "$_isvoid", to check whether an expression
2429 is void. A void expression is an expression where the type of the
2430 result is "void". For example, some convenience variables may be
2431 "void" when evaluated (e.g., "$_exitcode" before the execution of
2432 the program being debugged; or an undefined convenience variable).
2433 Another example, when calling a function whose return type is
2436 * The "maintenance print objfiles" command now takes an optional regexp.
2438 * The "catch syscall" command now works on arm*-linux* targets.
2440 * GDB now consistently shows "<not saved>" when printing values of
2441 registers the debug info indicates have not been saved in the frame
2442 and there's nowhere to retrieve them from
2443 (callee-saved/call-clobbered registers):
2448 (gdb) info registers rax
2451 Before, the former would print "<optimized out>", and the latter
2452 "*value not available*".
2454 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2459 ** Frame filters and frame decorators have been added.
2460 ** Temporary breakpoints are now supported.
2461 ** Line tables representation has been added.
2462 ** New attribute 'parent_type' for gdb.Field objects.
2463 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2464 ** New attribute 'name' for gdb.Type objects.
2468 Nios II ELF nios2*-*-elf
2469 Nios II GNU/Linux nios2*-*-linux
2470 Texas Instruments MSP430 msp430*-*-elf
2472 * Removed native configurations
2474 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2475 been removed. ELF variants of these configurations are kept supported.
2477 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2478 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2479 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2480 i[34567]86-*-openbsd3.[0-3]
2481 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2482 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2483 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2487 Like "catch throw", but catches a re-thrown exception.
2488 maint check-psymtabs
2489 Renamed from old "maint check-symtabs".
2491 Perform consistency checks on symtabs.
2492 maint expand-symtabs
2493 Expand symtabs matching an optional regexp.
2496 Display the details of GDB configure-time options.
2498 maint set|show per-command
2499 maint set|show per-command space
2500 maint set|show per-command time
2501 maint set|show per-command symtab
2502 Enable display of per-command gdb resource usage.
2504 remove-symbol-file FILENAME
2505 remove-symbol-file -a ADDRESS
2506 Remove a symbol file added via add-symbol-file. The file to remove
2507 can be identified by its filename or by an address that lies within
2508 the boundaries of this symbol file in memory.
2511 info exceptions REGEXP
2512 Display the list of Ada exceptions defined in the program being
2513 debugged. If provided, only the exceptions whose names match REGEXP
2518 set debug symfile off|on
2520 Control display of debugging info regarding reading symbol files and
2521 symbol tables within those files
2523 set print raw frame-arguments
2524 show print raw frame-arguments
2525 Set/show whether to print frame arguments in raw mode,
2526 disregarding any defined pretty-printers.
2528 set remote trace-status-packet
2529 show remote trace-status-packet
2530 Set/show the use of remote protocol qTStatus packet.
2534 Control display of debugging messages related to Nios II targets.
2538 Control whether target-assisted range stepping is enabled.
2540 set startup-with-shell
2541 show startup-with-shell
2542 Specifies whether Unix child processes are started via a shell or
2547 Use the target memory cache for accesses to the code segment. This
2548 improves performance of remote debugging (particularly disassembly).
2550 * You can now use a literal value 'unlimited' for options that
2551 interpret 0 or -1 as meaning "unlimited". E.g., "set
2552 trace-buffer-size unlimited" is now an alias for "set
2553 trace-buffer-size -1" and "set height unlimited" is now an alias for
2556 * The "set debug symtab-create" debugging option of GDB has been changed to
2557 accept a verbosity level. 0 means "off", 1 provides basic debugging
2558 output, and values of 2 or greater provides more verbose output.
2560 * New command-line options
2562 Display the details of GDB configure-time options.
2564 * The command 'tsave' can now support new option '-ctf' to save trace
2565 buffer in Common Trace Format.
2567 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2570 * GDB now implements the C++ 'typeid' operator.
2572 * The new convenience variable $_exception holds the exception being
2573 thrown or caught at an exception-related catchpoint.
2575 * The exception-related catchpoints, like "catch throw", now accept a
2576 regular expression which can be used to filter exceptions by type.
2578 * The new convenience variable $_exitsignal is automatically set to
2579 the terminating signal number when the program being debugged dies
2580 due to an uncaught signal.
2584 ** All MI commands now accept an optional "--language" option.
2585 Support for this feature can be verified by using the "-list-features"
2586 command, which should contain "language-option".
2588 ** The new command -info-gdb-mi-command allows the user to determine
2589 whether a GDB/MI command is supported or not.
2591 ** The "^error" result record returned when trying to execute an undefined
2592 GDB/MI command now provides a variable named "code" whose content is the
2593 "undefined-command" error code. Support for this feature can be verified
2594 by using the "-list-features" command, which should contain
2595 "undefined-command-error-code".
2597 ** The -trace-save MI command can optionally save trace buffer in Common
2600 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2602 ** The command -data-list-register-values now accepts an optional
2603 "--skip-unavailable" option. When used, only the available registers
2606 ** The new command -trace-frame-collected dumps collected variables,
2607 computed expressions, tvars, memory and registers in a traceframe.
2609 ** The commands -stack-list-locals, -stack-list-arguments and
2610 -stack-list-variables now accept an option "--skip-unavailable".
2611 When used, only the available locals or arguments are displayed.
2613 ** The -exec-run command now accepts an optional "--start" option.
2614 When used, the command follows the same semantics as the "start"
2615 command, stopping the program's execution at the start of its
2616 main subprogram. Support for this feature can be verified using
2617 the "-list-features" command, which should contain
2618 "exec-run-start-option".
2620 ** The new commands -catch-assert and -catch-exceptions insert
2621 catchpoints stopping the program when Ada exceptions are raised.
2623 ** The new command -info-ada-exceptions provides the equivalent of
2624 the new "info exceptions" command.
2626 * New system-wide configuration scripts
2627 A GDB installation now provides scripts suitable for use as system-wide
2628 configuration scripts for the following systems:
2632 * GDB now supports target-assigned range stepping with remote targets.
2633 This improves the performance of stepping source lines by reducing
2634 the number of control packets from/to GDB. See "New remote packets"
2637 * GDB now understands the element 'tvar' in the XML traceframe info.
2638 It has the id of the collected trace state variables.
2640 * On S/390 targets that provide the transactional-execution feature,
2641 the program interruption transaction diagnostic block (TDB) is now
2642 represented as a number of additional "registers" in GDB.
2644 * New remote packets
2648 The vCont packet supports a new 'r' action, that tells the remote
2649 stub to step through an address range itself, without GDB
2650 involvemement at each single-step.
2652 qXfer:libraries-svr4:read's annex
2653 The previously unused annex of the qXfer:libraries-svr4:read packet
2654 is now used to support passing an argument list. The remote stub
2655 reports support for this argument list to GDB's qSupported query.
2656 The defined arguments are "start" and "prev", used to reduce work
2657 necessary for library list updating, resulting in significant
2660 * New features in the GDB remote stub, GDBserver
2662 ** GDBserver now supports target-assisted range stepping. Currently
2663 enabled on x86/x86_64 GNU/Linux targets.
2665 ** GDBserver now adds element 'tvar' in the XML in the reply to
2666 'qXfer:traceframe-info:read'. It has the id of the collected
2667 trace state variables.
2669 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2672 * New 'z' formatter for printing and examining memory, this displays the
2673 value as hexadecimal zero padded on the left to the size of the type.
2675 * GDB can now use Windows x64 unwinding data.
2677 * The "set remotebaud" command has been replaced by "set serial baud".
2678 Similarly, "show remotebaud" has been replaced by "show serial baud".
2679 The "set remotebaud" and "show remotebaud" commands are still available
2680 to provide backward compatibility with older versions of GDB.
2682 *** Changes in GDB 7.6
2684 * Target record has been renamed to record-full.
2685 Record/replay is now enabled with the "record full" command.
2686 This also affects settings that are associated with full record/replay
2687 that have been moved from "set/show record" to "set/show record full":
2689 set|show record full insn-number-max
2690 set|show record full stop-at-limit
2691 set|show record full memory-query
2693 * A new record target "record-btrace" has been added. The new target
2694 uses hardware support to record the control-flow of a process. It
2695 does not support replaying the execution, but it implements the
2696 below new commands for investigating the recorded execution log.
2697 This new recording method can be enabled using:
2701 The "record-btrace" target is only available on Intel Atom processors
2702 and requires a Linux kernel 2.6.32 or later.
2704 * Two new commands have been added for record/replay to give information
2705 about the recorded execution without having to replay the execution.
2706 The commands are only supported by "record btrace".
2708 record instruction-history prints the execution history at
2709 instruction granularity
2711 record function-call-history prints the execution history at
2712 function granularity
2714 * New native configurations
2716 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2717 FreeBSD/powerpc powerpc*-*-freebsd
2718 x86_64/Cygwin x86_64-*-cygwin*
2719 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2723 ARM AArch64 aarch64*-*-elf
2724 ARM AArch64 GNU/Linux aarch64*-*-linux
2725 Lynx 178 PowerPC powerpc-*-lynx*178
2726 x86_64/Cygwin x86_64-*-cygwin*
2727 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2729 * If the configured location of system.gdbinit file (as given by the
2730 --with-system-gdbinit option at configure time) is in the
2731 data-directory (as specified by --with-gdb-datadir at configure
2732 time) or in one of its subdirectories, then GDB will look for the
2733 system-wide init file in the directory specified by the
2734 --data-directory command-line option.
2736 * New command line options:
2738 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2739 other initialization files, unlike -nx which disables all of them.
2741 * Removed command line options
2743 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2746 * The 'ptype' and 'whatis' commands now accept an argument to control
2749 * 'info proc' now works on some core files.
2753 ** Vectors can be created with gdb.Type.vector.
2755 ** Python's atexit.register now works in GDB.
2757 ** Types can be pretty-printed via a Python API.
2759 ** Python 3 is now supported (in addition to Python 2.4 or later)
2761 ** New class gdb.Architecture exposes GDB's internal representation
2762 of architecture in the Python API.
2764 ** New method Frame.architecture returns the gdb.Architecture object
2765 corresponding to the frame's architecture.
2767 * New Python-based convenience functions:
2769 ** $_memeq(buf1, buf2, length)
2770 ** $_streq(str1, str2)
2772 ** $_regex(str, regex)
2774 * The 'cd' command now defaults to using '~' (the home directory) if not
2777 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2778 default for GCC since November 2000.
2780 * The command 'forward-search' can now be abbreviated as 'fo'.
2782 * The command 'info tracepoints' can now display 'installed on target'
2783 or 'not installed on target' for each non-pending location of tracepoint.
2785 * New configure options
2787 --enable-libmcheck/--disable-libmcheck
2788 By default, development versions are built with -lmcheck on hosts
2789 that support it, in order to help track memory corruption issues.
2790 Release versions, on the other hand, are built without -lmcheck
2791 by default. The --enable-libmcheck/--disable-libmcheck configure
2792 options allow the user to override that default.
2793 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2794 This configure option allows the user to build GDB with
2795 libbabeltrace using which GDB can read Common Trace Format data.
2797 * New commands (for set/show, see "New options" below)
2800 Catch signals. This is similar to "handle", but allows commands and
2801 conditions to be attached.
2804 List the BFDs known to GDB.
2806 python-interactive [command]
2808 Start a Python interactive prompt, or evaluate the optional command
2809 and print the result of expressions.
2812 "py" is a new alias for "python".
2814 enable type-printer [name]...
2815 disable type-printer [name]...
2816 Enable or disable type printers.
2820 ** For the Renesas Super-H architecture, the "regs" command has been removed
2821 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2826 set print type methods (on|off)
2827 show print type methods
2828 Control whether method declarations are displayed by "ptype".
2829 The default is to show them.
2831 set print type typedefs (on|off)
2832 show print type typedefs
2833 Control whether typedef definitions are displayed by "ptype".
2834 The default is to show them.
2836 set filename-display basename|relative|absolute
2837 show filename-display
2838 Control the way in which filenames is displayed.
2839 The default is "relative", which preserves previous behavior.
2841 set trace-buffer-size
2842 show trace-buffer-size
2843 Request target to change the size of trace buffer.
2845 set remote trace-buffer-size-packet auto|on|off
2846 show remote trace-buffer-size-packet
2847 Control the use of the remote protocol `QTBuffer:size' packet.
2851 Control display of debugging messages related to ARM AArch64.
2854 set debug coff-pe-read
2855 show debug coff-pe-read
2856 Control display of debugging messages related to reading of COFF/PE
2861 Control display of debugging messages related to Mach-O symbols
2864 set debug notification
2865 show debug notification
2866 Control display of debugging info for async remote notification.
2870 ** Command parameter changes are now notified using new async record
2871 "=cmd-param-changed".
2872 ** Trace frame changes caused by command "tfind" are now notified using
2873 new async record "=traceframe-changed".
2874 ** The creation, deletion and modification of trace state variables
2875 are now notified using new async records "=tsv-created",
2876 "=tsv-deleted" and "=tsv-modified".
2877 ** The start and stop of process record are now notified using new
2878 async record "=record-started" and "=record-stopped".
2879 ** Memory changes are now notified using new async record
2881 ** The data-disassemble command response will include a "fullname" field
2882 containing the absolute file name when source has been requested.
2883 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2884 command, to allow pattern filling of memory areas.
2885 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2886 library load/unload events.
2887 ** The response to breakpoint commands and breakpoint async records
2888 includes an "installed" field containing a boolean state about each
2889 non-pending tracepoint location is whether installed on target or not.
2890 ** Output of the "-trace-status" command includes a "trace-file" field
2891 containing the name of the trace file being examined. This field is
2892 optional, and only present when examining a trace file.
2893 ** The "fullname" field is now always present along with the "file" field,
2894 even if the file cannot be found by GDB.
2896 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2897 You must have the LZMA library available when configuring GDB for this
2898 feature to be enabled. For more information, see:
2899 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2901 * New remote packets
2904 Set the size of trace buffer. The remote stub reports support for this
2905 packet to gdb's qSupported query.
2908 Enable Branch Trace Store (BTS)-based branch tracing for the current
2909 thread. The remote stub reports support for this packet to gdb's
2913 Disable branch tracing for the current thread. The remote stub reports
2914 support for this packet to gdb's qSupported query.
2917 Read the traced branches for the current thread. The remote stub
2918 reports support for this packet to gdb's qSupported query.
2920 *** Changes in GDB 7.5
2922 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2923 for more x32 ABI info.
2925 * GDB now supports access to MIPS DSP registers on Linux targets.
2927 * GDB now supports debugging microMIPS binaries.
2929 * The "info os" command on GNU/Linux can now display information on
2930 several new classes of objects managed by the operating system:
2931 "info os procgroups" lists process groups
2932 "info os files" lists file descriptors
2933 "info os sockets" lists internet-domain sockets
2934 "info os shm" lists shared-memory regions
2935 "info os semaphores" lists semaphores
2936 "info os msg" lists message queues
2937 "info os modules" lists loaded kernel modules
2939 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2940 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2941 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2942 options and inspect the probe arguments using the new $_probe_arg family
2943 of convenience variables. You can obtain more information about SystemTap
2944 in <http://sourceware.org/systemtap/>.
2946 * GDB now supports reversible debugging on ARM, it allows you to
2947 debug basic ARM and THUMB instructions, and provides
2948 record/replay support.
2950 * The option "symbol-reloading" has been deleted as it is no longer used.
2954 ** GDB commands implemented in Python can now be put in command class
2957 ** The "maint set python print-stack on|off" is now deleted.
2959 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2960 apply "flag enum"-style pretty-printing to any enum.
2962 ** gdb.lookup_symbol can now work when there is no current frame.
2964 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2965 the source at which the symbol was defined.
2967 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2968 method 'value'. The former indicates whether the symbol needs a
2969 frame in order to compute its value, and the latter computes the
2972 ** A new method 'referenced_value' on gdb.Value objects which can
2973 dereference pointer as well as C++ reference values.
2975 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2976 which return the global and static blocks (as gdb.Block objects),
2977 of the underlying symbol table, respectively.
2979 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2980 object associated with a PC value.
2982 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2983 of the address range occupied by code for the current source line.
2985 * Go language support.
2986 GDB now supports debugging programs written in the Go programming
2989 * GDBserver now supports stdio connections.
2990 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2992 * The binary "gdbtui" can no longer be built or installed.
2993 Use "gdb -tui" instead.
2995 * GDB will now print "flag" enums specially. A flag enum is one where
2996 all the enumerator values have no bits in common when pairwise
2997 "and"ed. When printing a value whose type is a flag enum, GDB will
2998 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2999 (gdb) print (enum E) 3
3002 * The filename part of a linespec will now match trailing components
3003 of a source file name. For example, "break gcc/expr.c:1000" will
3004 now set a breakpoint in build/gcc/expr.c, but not
3005 build/libcpp/expr.c.
3007 * The "info proc" and "generate-core-file" commands will now also
3008 work on remote targets connected to GDBserver on Linux.
3010 * The command "info catch" has been removed. It has been disabled
3011 since December 2007.
3013 * The "catch exception" and "catch assert" commands now accept
3014 a condition at the end of the command, much like the "break"
3015 command does. For instance:
3017 (gdb) catch exception Constraint_Error if Barrier = True
3019 Previously, it was possible to add a condition to such catchpoints,
3020 but it had to be done as a second step, after the catchpoint had been
3021 created, using the "condition" command.
3023 * The "info static-tracepoint-marker" command will now also work on
3024 native Linux targets with in-process agent.
3026 * GDB can now set breakpoints on inlined functions.
3028 * The .gdb_index section has been updated to include symbols for
3029 inlined functions. GDB will ignore older .gdb_index sections by
3030 default, which could cause symbol files to be loaded more slowly
3031 until their .gdb_index sections can be recreated. The new command
3032 "set use-deprecated-index-sections on" will cause GDB to use any older
3033 .gdb_index sections it finds. This will restore performance, but the
3034 ability to set breakpoints on inlined functions will be lost in symbol
3035 files with older .gdb_index sections.
3037 The .gdb_index section has also been updated to record more information
3038 about each symbol. This speeds up the "info variables", "info functions"
3039 and "info types" commands when used with programs having the .gdb_index
3040 section, as well as speeding up debugging with shared libraries using
3041 the .gdb_index section.
3043 * Ada support for GDB/MI Variable Objects has been added.
3045 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3050 ** New command -info-os is the MI equivalent of "info os".
3052 ** Output logs ("set logging" and related) now include MI output.
3056 ** "set use-deprecated-index-sections on|off"
3057 "show use-deprecated-index-sections on|off"
3058 Controls the use of deprecated .gdb_index sections.
3060 ** "catch load" and "catch unload" can be used to stop when a shared
3061 library is loaded or unloaded, respectively.
3063 ** "enable count" can be used to auto-disable a breakpoint after
3066 ** "info vtbl" can be used to show the virtual method tables for
3067 C++ and Java objects.
3069 ** "explore" and its sub commands "explore value" and "explore type"
3070 can be used to recursively explore values and types of
3071 expressions. These commands are available only if GDB is
3072 configured with '--with-python'.
3074 ** "info auto-load" shows status of all kinds of auto-loaded files,
3075 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3076 sequences of commands files, "info auto-load python-scripts"
3077 shows status of auto-loading Python script files,
3078 "info auto-load local-gdbinit" shows status of loading init file
3079 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3080 status of inferior specific thread debugging shared library loading.
3082 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3083 and "show auto-load-scripts" commands have been deprecated, use their
3084 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3085 and "show auto-load python-scripts" counterparts instead.
3087 ** "dprintf location,format,args..." creates a dynamic printf, which
3088 is basically a breakpoint that does a printf and immediately
3089 resumes your program's execution, so it is like a printf that you
3090 can insert dynamically at runtime instead of at compiletime.
3092 ** "set print symbol"
3094 Controls whether GDB attempts to display the symbol, if any,
3095 corresponding to addresses it prints. This defaults to "on", but
3096 you can set it to "off" to restore GDB's previous behavior.
3098 * Deprecated commands
3100 ** For the Renesas Super-H architecture, the "regs" command has been
3101 deprecated, and "info all-registers" should be used instead.
3105 Renesas RL78 rl78-*-elf
3106 HP OpenVMS ia64 ia64-hp-openvms*
3108 * GDBserver supports evaluation of breakpoint conditions. When
3109 support is advertised by GDBserver, GDB may be told to send the
3110 breakpoint conditions in bytecode form to GDBserver. GDBserver
3111 will only report the breakpoint trigger to GDB when its condition
3116 set mips compression
3117 show mips compression
3118 Select the compressed ISA encoding used in functions that have no symbol
3119 information available. The encoding can be set to either of:
3122 and is updated automatically from ELF file flags if available.
3124 set breakpoint condition-evaluation
3125 show breakpoint condition-evaluation
3126 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3127 GDBserver ("target"). Default option "auto" chooses the most efficient
3129 This option can improve debugger efficiency depending on the speed of the
3133 Disable auto-loading globally.
3136 Show auto-loading setting of all kinds of auto-loaded files.
3138 set auto-load gdb-scripts on|off
3139 show auto-load gdb-scripts
3140 Control auto-loading of GDB canned sequences of commands files.
3142 set auto-load python-scripts on|off
3143 show auto-load python-scripts
3144 Control auto-loading of Python script files.
3146 set auto-load local-gdbinit on|off
3147 show auto-load local-gdbinit
3148 Control loading of init file (.gdbinit) from current directory.
3150 set auto-load libthread-db on|off
3151 show auto-load libthread-db
3152 Control auto-loading of inferior specific thread debugging shared library.
3154 set auto-load scripts-directory <dir1>[:<dir2>...]
3155 show auto-load scripts-directory
3156 Set a list of directories from which to load auto-loaded scripts.
3157 Automatically loaded Python scripts and GDB scripts are located in one
3158 of the directories listed by this option.
3159 The delimiter (':' above) may differ according to the host platform.
3161 set auto-load safe-path <dir1>[:<dir2>...]
3162 show auto-load safe-path
3163 Set a list of directories from which it is safe to auto-load files.
3164 The delimiter (':' above) may differ according to the host platform.
3166 set debug auto-load on|off
3167 show debug auto-load
3168 Control display of debugging info for auto-loading the files above.
3170 set dprintf-style gdb|call|agent
3172 Control the way in which a dynamic printf is performed; "gdb"
3173 requests a GDB printf command, while "call" causes dprintf to call a
3174 function in the inferior. "agent" requests that the target agent
3175 (such as GDBserver) do the printing.
3177 set dprintf-function <expr>
3178 show dprintf-function
3179 set dprintf-channel <expr>
3180 show dprintf-channel
3181 Set the function and optional first argument to the call when using
3182 the "call" style of dynamic printf.
3184 set disconnected-dprintf on|off
3185 show disconnected-dprintf
3186 Control whether agent-style dynamic printfs continue to be in effect
3187 after GDB disconnects.
3189 * New configure options
3191 --with-auto-load-dir
3192 Configure default value for the 'set auto-load scripts-directory'
3193 setting above. It defaults to '$debugdir:$datadir/auto-load',
3194 $debugdir representing global debugging info directories (available
3195 via 'show debug-file-directory') and $datadir representing GDB's data
3196 directory (available via 'show data-directory').
3198 --with-auto-load-safe-path
3199 Configure default value for the 'set auto-load safe-path' setting
3200 above. It defaults to the --with-auto-load-dir setting.
3202 --without-auto-load-safe-path
3203 Set 'set auto-load safe-path' to '/', effectively disabling this
3206 * New remote packets
3208 z0/z1 conditional breakpoints extension
3210 The z0/z1 breakpoint insertion packets have been extended to carry
3211 a list of conditional expressions over to the remote stub depending on the
3212 condition evaluation mode. The use of this extension can be controlled
3213 via the "set remote conditional-breakpoints-packet" command.
3217 Specify the signals which the remote stub may pass to the debugged
3218 program without GDB involvement.
3220 * New command line options
3222 --init-command=FILE, -ix Like --command, -x but execute it
3223 before loading inferior.
3224 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3225 execute it before loading inferior.
3227 *** Changes in GDB 7.4
3229 * GDB now handles ambiguous linespecs more consistently; the existing
3230 FILE:LINE support has been expanded to other types of linespecs. A
3231 breakpoint will now be set on all matching locations in all
3232 inferiors, and locations will be added or removed according to
3235 * GDB now allows you to skip uninteresting functions and files when
3236 stepping with the "skip function" and "skip file" commands.
3238 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3239 and "show remote hardware-watchpoint-length-limit". These allows to
3240 set or show the maximum length limit (in bytes) of a remote
3241 target hardware watchpoint.
3243 This allows e.g. to use "unlimited" hardware watchpoints with the
3244 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3245 watchpoints are slower than real hardware watchpoints but are
3246 significantly faster than gdb software watchpoints.
3250 ** The register_pretty_printer function in module gdb.printing now takes
3251 an optional `replace' argument. If True, the new printer replaces any
3254 ** The "maint set python print-stack on|off" command has been
3255 deprecated and will be deleted in GDB 7.5.
3256 A new command: "set python print-stack none|full|message" has
3257 replaced it. Additionally, the default for "print-stack" is
3258 now "message", which just prints the error message without
3261 ** A prompt substitution hook (prompt_hook) is now available to the
3264 ** A new Python module, gdb.prompt has been added to the GDB Python
3265 modules library. This module provides functionality for
3266 escape sequences in prompts (used by set/show
3267 extended-prompt). These escape sequences are replaced by their
3268 corresponding value.
3270 ** Python commands and convenience-functions located in
3271 'data-directory'/python/gdb/command and
3272 'data-directory'/python/gdb/function are now automatically loaded
3275 ** Blocks now provide four new attributes. global_block and
3276 static_block will return the global and static blocks
3277 respectively. is_static and is_global are boolean attributes
3278 that indicate if the block is one of those two types.
3280 ** Symbols now provide the "type" attribute, the type of the symbol.
3282 ** The "gdb.breakpoint" function has been deprecated in favor of
3285 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3286 of a function. This class is based on the "finish" command
3287 available in the CLI.
3289 ** Type objects for struct and union types now allow access to
3290 the fields using standard Python dictionary (mapping) methods.
3291 For example, "some_type['myfield']" now works, as does
3292 "some_type.items()".
3294 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3297 ** A new function, "deep_items" has been added to the gdb.types
3298 module in the GDB Python modules library. This function returns
3299 an iterator over the fields of a struct or union type. Unlike
3300 the standard Python "iteritems" method, it will recursively traverse
3301 any anonymous fields.
3305 ** "*stopped" events can report several new "reason"s, such as
3308 ** Breakpoint changes are now notified using new async records, like
3309 "=breakpoint-modified".
3311 ** New command -ada-task-info.
3313 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3314 $sdir specifies the default system locations of shared libraries.
3315 $pdir specifies the directory where the libpthread used by the application
3318 GDB no longer looks in $sdir and $pdir after it has searched the directories
3319 mentioned in libthread-db-search-path. If you want to search those
3320 directories, they must be specified in libthread-db-search-path.
3321 The default value of libthread-db-search-path on GNU/Linux and Solaris
3322 systems is now "$sdir:$pdir".
3324 $pdir is not supported by gdbserver, it is currently ignored.
3325 $sdir is supported by gdbserver.
3327 * New configure option --with-iconv-bin.
3328 When using the internationalization support like the one in the GNU C
3329 library, GDB will invoke the "iconv" program to get a list of supported
3330 character sets. If this program lives in a non-standard location, one can
3331 use this option to specify where to find it.
3333 * When natively debugging programs on PowerPC BookE processors running
3334 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3335 watchpoints, which specify a mask in addition to an address to watch.
3336 The mask specifies that some bits of an address (the bits which are
3337 reset in the mask) should be ignored when matching the address accessed
3338 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3339 section in the user manual for more details.
3341 * The new option --once causes GDBserver to stop listening for connections once
3342 the first connection is made. The listening port used by GDBserver will
3343 become available after that.
3345 * New commands "info macros" and "alias" have been added.
3347 * New function parameters suffix @entry specifies value of function parameter
3348 at the time the function got called. Entry values are available only since
3354 "!" is now an alias of the "shell" command.
3355 Note that no space is needed between "!" and SHELL COMMAND.
3359 watch EXPRESSION mask MASK_VALUE
3360 The watch command now supports the mask argument which allows creation
3361 of masked watchpoints, if the current architecture supports this feature.
3363 info auto-load-scripts [REGEXP]
3364 This command was formerly named "maintenance print section-scripts".
3365 It is now generally useful and is no longer a maintenance-only command.
3367 info macro [-all] [--] MACRO
3368 The info macro command has new options `-all' and `--'. The first for
3369 printing all definitions of a macro. The second for explicitly specifying
3370 the end of arguments and the beginning of the macro name in case the macro
3371 name starts with a hyphen.
3373 collect[/s] EXPRESSIONS
3374 The tracepoint collect command now takes an optional modifier "/s"
3375 that directs it to dereference pointer-to-character types and
3376 collect the bytes of memory up to a zero byte. The behavior is
3377 similar to what you see when you use the regular print command on a
3378 string. An optional integer following the "/s" sets a bound on the
3379 number of bytes that will be collected.
3382 The trace start command now interprets any supplied arguments as a
3383 note to be recorded with the trace run, with an effect similar to
3384 setting the variable trace-notes.
3387 The trace stop command now interprets any arguments as a note to be
3388 mentioned along with the tstatus report that the trace was stopped
3389 with a command. The effect is similar to setting the variable
3392 * Tracepoints can now be enabled and disabled at any time after a trace
3393 experiment has been started using the standard "enable" and "disable"
3394 commands. It is now possible to start a trace experiment with no enabled
3395 tracepoints; GDB will display a warning, but will allow the experiment to
3396 begin, assuming that tracepoints will be enabled as needed while the trace
3399 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3400 locations with 4-byte instructions, when they were previously
3401 limited to locations with instructions of 5 bytes or longer.
3405 set debug dwarf2-read
3406 show debug dwarf2-read
3407 Turns on or off display of debugging messages related to reading
3408 DWARF debug info. The default is off.
3410 set debug symtab-create
3411 show debug symtab-create
3412 Turns on or off display of debugging messages related to symbol table
3413 creation. The default is off.
3416 show extended-prompt
3417 Set the GDB prompt, and allow escape sequences to be inserted to
3418 display miscellaneous information (see 'help set extended-prompt'
3419 for the list of sequences). This prompt (and any information
3420 accessed through the escape sequences) is updated every time the
3421 prompt is displayed.
3423 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3424 show print entry-values
3425 Set printing of frame argument values at function entry. In some cases
3426 GDB can determine the value of function argument which was passed by the
3427 function caller, even if the value was modified inside the called function.
3429 set debug entry-values
3430 show debug entry-values
3431 Control display of debugging info for determining frame argument values at
3432 function entry and virtual tail call frames.
3434 set basenames-may-differ
3435 show basenames-may-differ
3436 Set whether a source file may have multiple base names.
3437 (A "base name" is the name of a file with the directory part removed.
3438 Example: The base name of "/home/user/hello.c" is "hello.c".)
3439 If set, GDB will canonicalize file names (e.g., expand symlinks)
3440 before comparing them. Canonicalization is an expensive operation,
3441 but it allows the same file be known by more than one base name.
3442 If not set (the default), all source files are assumed to have just
3443 one base name, and gdb will do file name comparisons more efficiently.
3449 Set a user name and notes for the current and any future trace runs.
3450 This is useful for long-running and/or disconnected traces, to
3451 inform others (or yourself) as to who is running the trace, supply
3452 contact information, or otherwise explain what is going on.
3454 set trace-stop-notes
3455 show trace-stop-notes
3456 Set a note attached to the trace run, that is displayed when the
3457 trace has been stopped by a tstop command. This is useful for
3458 instance as an explanation, if you are stopping a trace run that was
3459 started by someone else.
3461 * New remote packets
3465 Dynamically enable a tracepoint in a started trace experiment.
3469 Dynamically disable a tracepoint in a started trace experiment.
3473 Set the user and notes of the trace run.
3477 Query the current status of a tracepoint.
3481 Query the minimum length of instruction at which a fast tracepoint may
3484 * Dcache size (number of lines) and line-size are now runtime-configurable
3485 via "set dcache line" and "set dcache line-size" commands.
3489 Texas Instruments TMS320C6x tic6x-*-*
3493 Renesas RL78 rl78-*-elf
3495 *** Changes in GDB 7.3.1
3497 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3499 *** Changes in GDB 7.3
3501 * GDB has a new command: "thread find [REGEXP]".
3502 It finds the thread id whose name, target id, or thread extra info
3503 matches the given regular expression.
3505 * The "catch syscall" command now works on mips*-linux* targets.
3507 * The -data-disassemble MI command now supports modes 2 and 3 for
3508 dumping the instruction opcodes.
3510 * New command line options
3512 -data-directory DIR Specify DIR as the "data-directory".
3513 This is mostly for testing purposes.
3515 * The "maint set python auto-load on|off" command has been renamed to
3516 "set auto-load-scripts on|off".
3518 * GDB has a new command: "set directories".
3519 It is like the "dir" command except that it replaces the
3520 source path list instead of augmenting it.
3522 * GDB now understands thread names.
3524 On GNU/Linux, "info threads" will display the thread name as set by
3525 prctl or pthread_setname_np.
3527 There is also a new command, "thread name", which can be used to
3528 assign a name internally for GDB to display.
3531 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3532 has been integrated into GDB.
3536 ** The function gdb.Write now accepts an optional keyword 'stream'.
3537 This keyword, when provided, will direct the output to either
3538 stdout, stderr, or GDB's logging output.
3540 ** Parameters can now be be sub-classed in Python, and in particular
3541 you may implement the get_set_doc and get_show_doc functions.
3542 This improves how Parameter set/show documentation is processed
3543 and allows for more dynamic content.
3545 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3546 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3547 have an is_valid method.
3549 ** Breakpoints can now be sub-classed in Python, and in particular
3550 you may implement a 'stop' function that is executed each time
3551 the inferior reaches that breakpoint.
3553 ** New function gdb.lookup_global_symbol looks up a global symbol.
3555 ** GDB values in Python are now callable if the value represents a
3556 function. For example, if 'some_value' represents a function that
3557 takes two integer parameters and returns a value, you can call
3558 that function like so:
3560 result = some_value (10,20)
3562 ** Module gdb.types has been added.
3563 It contains a collection of utilities for working with gdb.Types objects:
3564 get_basic_type, has_field, make_enum_dict.
3566 ** Module gdb.printing has been added.
3567 It contains utilities for writing and registering pretty-printers.
3568 New classes: PrettyPrinter, SubPrettyPrinter,
3569 RegexpCollectionPrettyPrinter.
3570 New function: register_pretty_printer.
3572 ** New commands "info pretty-printers", "enable pretty-printer" and
3573 "disable pretty-printer" have been added.
3575 ** gdb.parameter("directories") is now available.
3577 ** New function gdb.newest_frame returns the newest frame in the
3580 ** The gdb.InferiorThread class has a new "name" attribute. This
3581 holds the thread's name.
3583 ** Python Support for Inferior events.
3584 Python scripts can add observers to be notified of events
3585 occurring in the process being debugged.
3586 The following events are currently supported:
3587 - gdb.events.cont Continue event.
3588 - gdb.events.exited Inferior exited event.
3589 - gdb.events.stop Signal received, and Breakpoint hit events.
3593 ** GDB now puts template parameters in scope when debugging in an
3594 instantiation. For example, if you have:
3596 template<int X> int func (void) { return X; }
3598 then if you step into func<5>, "print X" will show "5". This
3599 feature requires proper debuginfo support from the compiler; it
3600 was added to GCC 4.5.
3602 ** The motion commands "next", "finish", "until", and "advance" now
3603 work better when exceptions are thrown. In particular, GDB will
3604 no longer lose control of the inferior; instead, the GDB will
3605 stop the inferior at the point at which the exception is caught.
3606 This functionality requires a change in the exception handling
3607 code that was introduced in GCC 4.5.
3609 * GDB now follows GCC's rules on accessing volatile objects when
3610 reading or writing target state during expression evaluation.
3611 One notable difference to prior behavior is that "print x = 0"
3612 no longer generates a read of x; the value of the assignment is
3613 now always taken directly from the value being assigned.
3615 * GDB now has some support for using labels in the program's source in
3616 linespecs. For instance, you can use "advance label" to continue
3617 execution to a label.
3619 * GDB now has support for reading and writing a new .gdb_index
3620 section. This section holds a fast index of DWARF debugging
3621 information and can be used to greatly speed up GDB startup and
3622 operation. See the documentation for `save gdb-index' for details.
3624 * The "watch" command now accepts an optional "-location" argument.
3625 When used, this causes GDB to watch the memory referred to by the
3626 expression. Such a watchpoint is never deleted due to it going out
3629 * GDB now supports thread debugging of core dumps on GNU/Linux.
3631 GDB now activates thread debugging using the libthread_db library
3632 when debugging GNU/Linux core dumps, similarly to when debugging
3633 live processes. As a result, when debugging a core dump file, GDB
3634 is now able to display pthread_t ids of threads. For example, "info
3635 threads" shows the same output as when debugging the process when it
3636 was live. In earlier releases, you'd see something like this:
3639 * 1 LWP 6780 main () at main.c:10
3641 While now you see this:
3644 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3646 It is also now possible to inspect TLS variables when debugging core
3649 When debugging a core dump generated on a machine other than the one
3650 used to run GDB, you may need to point GDB at the correct
3651 libthread_db library with the "set libthread-db-search-path"
3652 command. See the user manual for more details on this command.
3654 * When natively debugging programs on PowerPC BookE processors running
3655 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3656 which stop execution of the inferior whenever it executes an instruction
3657 at any address within the specified range. See the "PowerPC Embedded"
3658 section in the user manual for more details.
3660 * New features in the GDB remote stub, GDBserver
3662 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3663 and i686 LynxOS (version 5.x).
3665 ** GDBserver is now supported on Blackfin Linux.
3667 * New native configurations
3669 ia64 HP-UX ia64-*-hpux*
3673 Analog Devices, Inc. Blackfin Processor bfin-*
3675 * Ada task switching is now supported on sparc-elf targets when
3676 debugging a program using the Ravenscar Profile. For more information,
3677 see the "Tasking Support when using the Ravenscar Profile" section
3678 in the GDB user manual.
3680 * Guile support was removed.
3682 * New features in the GNU simulator
3684 ** The --map-info flag lists all known core mappings.
3686 ** CFI flashes may be simulated via the "cfi" device.
3688 *** Changes in GDB 7.2
3690 * Shared library support for remote targets by default
3692 When GDB is configured for a generic, non-OS specific target, like
3693 for example, --target=arm-eabi or one of the many *-*-elf targets,
3694 GDB now queries remote stubs for loaded shared libraries using the
3695 `qXfer:libraries:read' packet. Previously, shared library support
3696 was always disabled for such configurations.
3700 ** Argument Dependent Lookup (ADL)
3702 In C++ ADL lookup directs function search to the namespaces of its
3703 arguments even if the namespace has not been imported.
3713 Here the compiler will search for `foo' in the namespace of 'b'
3714 and find A::foo. GDB now supports this. This construct is commonly
3715 used in the Standard Template Library for operators.
3717 ** Improved User Defined Operator Support
3719 In addition to member operators, GDB now supports lookup of operators
3720 defined in a namespace and imported with a `using' directive, operators
3721 defined in the global scope, operators imported implicitly from an
3722 anonymous namespace, and the ADL operators mentioned in the previous
3724 GDB now also supports proper overload resolution for all the previously
3725 mentioned flavors of operators.
3727 ** static const class members
3729 Printing of static const class members that are initialized in the
3730 class definition has been fixed.
3732 * Windows Thread Information Block access.
3734 On Windows targets, GDB now supports displaying the Windows Thread
3735 Information Block (TIB) structure. This structure is visible either
3736 by using the new command `info w32 thread-information-block' or, by
3737 dereferencing the new convenience variable named `$_tlb', a
3738 thread-specific pointer to the TIB. This feature is also supported
3739 when remote debugging using GDBserver.
3741 * Static tracepoints
3743 Static tracepoints are calls in the user program into a tracing
3744 library. One such library is a port of the LTTng kernel tracer to
3745 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3746 When debugging with GDBserver, GDB now supports combining the GDB
3747 tracepoint machinery with such libraries. For example: the user can
3748 use GDB to probe a static tracepoint marker (a call from the user
3749 program into the tracing library) with the new "strace" command (see
3750 "New commands" below). This creates a "static tracepoint" in the
3751 breakpoint list, that can be manipulated with the same feature set
3752 as fast and regular tracepoints. E.g., collect registers, local and
3753 global variables, collect trace state variables, and define
3754 tracepoint conditions. In addition, the user can collect extra
3755 static tracepoint marker specific data, by collecting the new
3756 $_sdata internal variable. When analyzing the trace buffer, you can
3757 inspect $_sdata like any other variable available to GDB. For more
3758 information, see the "Tracepoints" chapter in GDB user manual. New
3759 remote packets have been defined to support static tracepoints, see
3760 the "New remote packets" section below.
3762 * Better reconstruction of tracepoints after disconnected tracing
3764 GDB will attempt to download the original source form of tracepoint
3765 definitions when starting a trace run, and then will upload these
3766 upon reconnection to the target, resulting in a more accurate
3767 reconstruction of the tracepoints that are in use on the target.
3771 You can now exercise direct control over the ways that GDB can
3772 affect your program. For instance, you can disallow the setting of
3773 breakpoints, so that the program can run continuously (assuming
3774 non-stop mode). In addition, the "observer" variable is available
3775 to switch all of the different controls; in observer mode, GDB
3776 cannot affect the target's behavior at all, which is useful for
3777 tasks like diagnosing live systems in the field.
3779 * The new convenience variable $_thread holds the number of the
3782 * New remote packets
3786 Return the address of the Windows Thread Information Block of a given thread.
3790 In response to several of the tracepoint packets, the target may now
3791 also respond with a number of intermediate `qRelocInsn' request
3792 packets before the final result packet, to have GDB handle
3793 relocating an instruction to execute at a different address. This
3794 is particularly useful for stubs that support fast tracepoints. GDB
3795 reports support for this feature in the qSupported packet.
3799 List static tracepoint markers in the target program.
3803 List static tracepoint markers at a given address in the target
3806 qXfer:statictrace:read
3808 Read the static trace data collected (by a `collect $_sdata'
3809 tracepoint action). The remote stub reports support for this packet
3810 to gdb's qSupported query.
3814 Send the current settings of GDB's permission flags.
3818 Send part of the source (textual) form of a tracepoint definition,
3819 which includes location, conditional, and action list.
3821 * The source command now accepts a -s option to force searching for the
3822 script in the source search path even if the script name specifies
3825 * New features in the GDB remote stub, GDBserver
3827 - GDBserver now support tracepoints (including fast tracepoints, and
3828 static tracepoints). The feature is currently supported by the
3829 i386-linux and amd64-linux builds. See the "Tracepoints support
3830 in gdbserver" section in the manual for more information.
3832 GDBserver JIT compiles the tracepoint's conditional agent
3833 expression bytecode into native code whenever possible for low
3834 overhead dynamic tracepoints conditionals. For such tracepoints,
3835 an expression that examines program state is evaluated when the
3836 tracepoint is reached, in order to determine whether to capture
3837 trace data. If the condition is simple and false, processing the
3838 tracepoint finishes very quickly and no data is gathered.
3840 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3841 for static tracepoints support.
3843 - GDBserver now supports x86_64 Windows 64-bit debugging.
3845 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3846 it understands register description.
3848 * The --batch flag now disables pagination and queries.
3850 * X86 general purpose registers
3852 GDB now supports reading/writing byte, word and double-word x86
3853 general purpose registers directly. This means you can use, say,
3854 $ah or $ax to refer, respectively, to the byte register AH and
3855 16-bit word register AX that are actually portions of the 32-bit
3856 register EAX or 64-bit register RAX.
3858 * The `commands' command now accepts a range of breakpoints to modify.
3859 A plain `commands' following a command that creates multiple
3860 breakpoints affects all the breakpoints set by that command. This
3861 applies to breakpoints set by `rbreak', and also applies when a
3862 single `break' command creates multiple breakpoints (e.g.,
3863 breakpoints on overloaded c++ functions).
3865 * The `rbreak' command now accepts a filename specification as part of
3866 its argument, limiting the functions selected by the regex to those
3867 in the specified file.
3869 * Support for remote debugging Windows and SymbianOS shared libraries
3870 from Unix hosts has been improved. Non Windows GDB builds now can
3871 understand target reported file names that follow MS-DOS based file
3872 system semantics, such as file names that include drive letters and
3873 use the backslash character as directory separator. This makes it
3874 possible to transparently use the "set sysroot" and "set
3875 solib-search-path" on Unix hosts to point as host copies of the
3876 target's shared libraries. See the new command "set
3877 target-file-system-kind" described below, and the "Commands to
3878 specify files" section in the user manual for more information.
3882 eval template, expressions...
3883 Convert the values of one or more expressions under the control
3884 of the string template to a command line, and call it.
3886 set target-file-system-kind unix|dos-based|auto
3887 show target-file-system-kind
3888 Set or show the assumed file system kind for target reported file
3891 save breakpoints <filename>
3892 Save all current breakpoint definitions to a file suitable for use
3893 in a later debugging session. To read the saved breakpoint
3894 definitions, use the `source' command.
3896 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3899 info static-tracepoint-markers
3900 Display information about static tracepoint markers in the target.
3902 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3903 Define a static tracepoint by probing a marker at the given
3904 function, line, address, or marker ID.
3908 Enable and disable observer mode.
3910 set may-write-registers on|off
3911 set may-write-memory on|off
3912 set may-insert-breakpoints on|off
3913 set may-insert-tracepoints on|off
3914 set may-insert-fast-tracepoints on|off
3915 set may-interrupt on|off
3916 Set individual permissions for GDB effects on the target. Note that
3917 some of these settings can have undesirable or surprising
3918 consequences, particularly when changed in the middle of a session.
3919 For instance, disabling the writing of memory can prevent
3920 breakpoints from being inserted, cause single-stepping to fail, or
3921 even crash your program, if you disable after breakpoints have been
3922 inserted. However, GDB should not crash.
3924 set record memory-query on|off
3925 show record memory-query
3926 Control whether to stop the inferior if memory changes caused
3927 by an instruction cannot be recorded.
3932 The disassemble command now supports "start,+length" form of two arguments.
3936 ** GDB now provides a new directory location, called the python directory,
3937 where Python scripts written for GDB can be installed. The location
3938 of that directory is <data-directory>/python, where <data-directory>
3939 is the GDB data directory. For more details, see section `Scripting
3940 GDB using Python' in the manual.
3942 ** The GDB Python API now has access to breakpoints, symbols, symbol
3943 tables, program spaces, inferiors, threads and frame's code blocks.
3944 Additionally, GDB Parameters can now be created from the API, and
3945 manipulated via set/show in the CLI.
3947 ** New functions gdb.target_charset, gdb.target_wide_charset,
3948 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3950 ** New exception gdb.GdbError.
3952 ** Pretty-printers are now also looked up in the current program space.
3954 ** Pretty-printers can now be individually enabled and disabled.
3956 ** GDB now looks for names of Python scripts to auto-load in a
3957 special section named `.debug_gdb_scripts', in addition to looking
3958 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3960 * Tracepoint actions were unified with breakpoint commands. In particular,
3961 there are no longer differences in "info break" output for breakpoints and
3962 tracepoints and the "commands" command can be used for both tracepoints and
3963 regular breakpoints.
3967 ARM Symbian arm*-*-symbianelf*
3969 * D language support.
3970 GDB now supports debugging programs written in the D programming
3973 * GDB now supports the extended ptrace interface for PowerPC which is
3974 available since Linux kernel version 2.6.34. This automatically enables
3975 any hardware breakpoints and additional hardware watchpoints available in
3976 the processor. The old ptrace interface exposes just one hardware
3977 watchpoint and no hardware breakpoints.
3979 * GDB is now able to use the Data Value Compare (DVC) register available on
3980 embedded PowerPC processors to implement in hardware simple watchpoint
3981 conditions of the form:
3983 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3985 This works in native GDB running on Linux kernels with the extended ptrace
3986 interface mentioned above.
3988 *** Changes in GDB 7.1
3992 ** Namespace Support
3994 GDB now supports importing of namespaces in C++. This enables the
3995 user to inspect variables from imported namespaces. Support for
3996 namepace aliasing has also been added. So, if a namespace is
3997 aliased in the current scope (e.g. namepace C=A; ) the user can
3998 print variables using the alias (e.g. (gdb) print C::x).
4002 All known bugs relating to the printing of virtual base class were
4003 fixed. It is now possible to call overloaded static methods using a
4008 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4009 and reinterpret_cast<> are now handled by the C++ expression parser.
4013 Xilinx MicroBlaze microblaze-*-*
4018 Xilinx MicroBlaze microblaze
4021 * Multi-program debugging.
4023 GDB now has support for multi-program (a.k.a. multi-executable or
4024 multi-exec) debugging. This allows for debugging multiple inferiors
4025 simultaneously each running a different program under the same GDB
4026 session. See "Debugging Multiple Inferiors and Programs" in the
4027 manual for more information. This implied some user visible changes
4028 in the multi-inferior support. For example, "info inferiors" now
4029 lists inferiors that are not running yet or that have exited
4030 already. See also "New commands" and "New options" below.
4032 * New tracing features
4034 GDB's tracepoint facility now includes several new features:
4036 ** Trace state variables
4038 GDB tracepoints now include support for trace state variables, which
4039 are variables managed by the target agent during a tracing
4040 experiment. They are useful for tracepoints that trigger each
4041 other, so for instance one tracepoint can count hits in a variable,
4042 and then a second tracepoint has a condition that is true when the
4043 count reaches a particular value. Trace state variables share the
4044 $-syntax of GDB convenience variables, and can appear in both
4045 tracepoint actions and condition expressions. Use the "tvariable"
4046 command to create, and "info tvariables" to view; see "Trace State
4047 Variables" in the manual for more detail.
4051 GDB now includes an option for defining fast tracepoints, which
4052 targets may implement more efficiently, such as by installing a jump
4053 into the target agent rather than a trap instruction. The resulting
4054 speedup can be by two orders of magnitude or more, although the
4055 tradeoff is that some program locations on some target architectures
4056 might not allow fast tracepoint installation, for instance if the
4057 instruction to be replaced is shorter than the jump. To request a
4058 fast tracepoint, use the "ftrace" command, with syntax identical to
4059 the regular trace command.
4061 ** Disconnected tracing
4063 It is now possible to detach GDB from the target while it is running
4064 a trace experiment, then reconnect later to see how the experiment
4065 is going. In addition, a new variable disconnected-tracing lets you
4066 tell the target agent whether to continue running a trace if the
4067 connection is lost unexpectedly.
4071 GDB now has the ability to save the trace buffer into a file, and
4072 then use that file as a target, similarly to you can do with
4073 corefiles. You can select trace frames, print data that was
4074 collected in them, and use tstatus to display the state of the
4075 tracing run at the moment that it was saved. To create a trace
4076 file, use "tsave <filename>", and to use it, do "target tfile
4079 ** Circular trace buffer
4081 You can ask the target agent to handle the trace buffer as a
4082 circular buffer, discarding the oldest trace frames to make room for
4083 newer ones, by setting circular-trace-buffer to on. This feature may
4084 not be available for all target agents.
4089 The disassemble command, when invoked with two arguments, now requires
4090 the arguments to be comma-separated.
4093 The info variables command now displays variable definitions. Files
4094 which only declare a variable are not shown.
4097 The source command is now capable of sourcing Python scripts.
4098 This feature is dependent on the debugger being build with Python
4101 Related to this enhancement is also the introduction of a new command
4102 "set script-extension" (see below).
4104 * New commands (for set/show, see "New options" below)
4106 record save [<FILENAME>]
4107 Save a file (in core file format) containing the process record
4108 execution log for replay debugging at a later time.
4110 record restore <FILENAME>
4111 Restore the process record execution log that was saved at an
4112 earlier time, for replay debugging.
4114 add-inferior [-copies <N>] [-exec <FILENAME>]
4117 clone-inferior [-copies <N>] [ID]
4118 Make a new inferior ready to execute the same program another
4119 inferior has loaded.
4124 maint info program-spaces
4125 List the program spaces loaded into GDB.
4127 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4128 show remote interrupt-sequence
4129 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4130 as the sequence to the remote target in order to interrupt the execution.
4131 Ctrl-C is a default. Some system prefers BREAK which is high level of
4132 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4133 Magic SysRq g. It is BREAK signal and character 'g'.
4135 set remote interrupt-on-connect [on | off]
4136 show remote interrupt-on-connect
4137 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4138 remote target when gdb connects to it. This is needed when you debug
4141 set remotebreak [on | off]
4143 Deprecated. Use "set/show remote interrupt-sequence" instead.
4145 tvariable $NAME [ = EXP ]
4146 Create or modify a trace state variable.
4149 List trace state variables and their values.
4151 delete tvariable $NAME ...
4152 Delete one or more trace state variables.
4155 Evaluate the given expressions without collecting anything into the
4156 trace buffer. (Valid in tracepoint actions only.)
4158 ftrace FN / FILE:LINE / *ADDR
4159 Define a fast tracepoint at the given function, line, or address.
4161 * New expression syntax
4163 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4164 GDB now parses 0b101010 identically with 42.
4168 set follow-exec-mode new|same
4169 show follow-exec-mode
4170 Control whether GDB reuses the same inferior across an exec call or
4171 creates a new one. This is useful to be able to restart the old
4172 executable after the inferior having done an exec call.
4174 set default-collect EXPR, ...
4175 show default-collect
4176 Define a list of expressions to be collected at each tracepoint.
4177 This is a useful way to ensure essential items are not overlooked,
4178 such as registers or a critical global variable.
4180 set disconnected-tracing
4181 show disconnected-tracing
4182 If set to 1, the target is instructed to continue tracing if it
4183 loses its connection to GDB. If 0, the target is to stop tracing
4186 set circular-trace-buffer
4187 show circular-trace-buffer
4188 If set to on, the target is instructed to use a circular trace buffer
4189 and discard the oldest trace frames instead of stopping the trace due
4190 to a full trace buffer. If set to off, the trace stops when the buffer
4191 fills up. Some targets may not support this.
4193 set script-extension off|soft|strict
4194 show script-extension
4195 If set to "off", the debugger does not perform any script language
4196 recognition, and all sourced files are assumed to be GDB scripts.
4197 If set to "soft" (the default), files are sourced according to
4198 filename extension, falling back to GDB scripts if the first
4200 If set to "strict", files are sourced according to filename extension.
4202 set ada trust-PAD-over-XVS on|off
4203 show ada trust-PAD-over-XVS
4204 If off, activate a workaround against a bug in the debugging information
4205 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4206 the GCC sources for more information about the GNAT encoding and
4207 PAD types in particular). It is always safe to set this option to
4208 off, but this introduces a slight performance penalty. The default
4211 * Python API Improvements
4213 ** GDB provides the new class gdb.LazyString. This is useful in
4214 some pretty-printing cases. The new method gdb.Value.lazy_string
4215 provides a simple way to create objects of this type.
4217 ** The fields returned by gdb.Type.fields now have an
4218 `is_base_class' attribute.
4220 ** The new method gdb.Type.range returns the range of an array type.
4222 ** The new method gdb.parse_and_eval can be used to parse and
4223 evaluate an expression.
4225 * New remote packets
4228 Define a trace state variable.
4231 Get the current value of a trace state variable.
4234 Set desired tracing behavior upon disconnection.
4237 Set the trace buffer to be linear or circular.
4240 Get data about the tracepoints currently in use.
4244 Process record now works correctly with hardware watchpoints.
4246 Multiple bug fixes have been made to the mips-irix port, making it
4247 much more reliable. In particular:
4248 - Debugging threaded applications is now possible again. Previously,
4249 GDB would hang while starting the program, or while waiting for
4250 the program to stop at a breakpoint.
4251 - Attaching to a running process no longer hangs.
4252 - An error occurring while loading a core file has been fixed.
4253 - Changing the value of the PC register now works again. This fixes
4254 problems observed when using the "jump" command, or when calling
4255 a function from GDB, or even when assigning a new value to $pc.
4256 - With the "finish" and "return" commands, the return value for functions
4257 returning a small array is now correctly printed.
4258 - It is now possible to break on shared library code which gets executed
4259 during a shared library init phase (code executed while executing
4260 their .init section). Previously, the breakpoint would have no effect.
4261 - GDB is now able to backtrace through the signal handler for
4262 non-threaded programs.
4264 PIE (Position Independent Executable) programs debugging is now supported.
4265 This includes debugging execution of PIC (Position Independent Code) shared
4266 libraries although for that, it should be possible to run such libraries as an
4269 *** Changes in GDB 7.0
4271 * GDB now has an interface for JIT compilation. Applications that
4272 dynamically generate code can create symbol files in memory and register
4273 them with GDB. For users, the feature should work transparently, and
4274 for JIT developers, the interface is documented in the GDB manual in the
4275 "JIT Compilation Interface" chapter.
4277 * Tracepoints may now be conditional. The syntax is as for
4278 breakpoints; either an "if" clause appended to the "trace" command,
4279 or the "condition" command is available. GDB sends the condition to
4280 the target for evaluation using the same bytecode format as is used
4281 for tracepoint actions.
4283 * The disassemble command now supports: an optional /r modifier, print the
4284 raw instructions in hex as well as in symbolic form, and an optional /m
4285 modifier to print mixed source+assembly.
4287 * Process record and replay
4289 In a architecture environment that supports ``process record and
4290 replay'', ``process record and replay'' target can record a log of
4291 the process execution, and replay it with both forward and reverse
4294 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4295 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4296 set execution-direction {forward|reverse}, for targets that support
4299 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4300 feature is available with a native GDB running on kernel version
4303 * GDB now has support for multi-byte and wide character sets on the
4304 target. Strings whose character type is wchar_t, char16_t, or
4305 char32_t are now correctly printed. GDB supports wide- and unicode-
4306 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4307 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4308 `printf'. This feature requires iconv to work properly; if your
4309 system does not have a working iconv, GDB can use GNU libiconv. See
4310 the installation instructions for more information.
4312 * GDB now supports automatic retrieval of shared library files from
4313 remote targets. To use this feature, specify a system root that begins
4314 with the `remote:' prefix, either via the `set sysroot' command or via
4315 the `--with-sysroot' configure-time option.
4317 * "info sharedlibrary" now takes an optional regex of libraries to show,
4318 and it now reports if a shared library has no debugging information.
4320 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4321 now complete on file names.
4323 * When completing in expressions, gdb will attempt to limit
4324 completions to allowable structure or union fields, where appropriate.
4325 For instance, consider:
4327 # struct example { int f1; double f2; };
4328 # struct example variable;
4331 If the user types TAB at the end of this command line, the available
4332 completions will be "f1" and "f2".
4334 * Inlined functions are now supported. They show up in backtraces, and
4335 the "step", "next", and "finish" commands handle them automatically.
4337 * GDB now supports the token-splicing (##) and stringification (#)
4338 operators when expanding macros. It also supports variable-arity
4341 * GDB now supports inspecting extra signal information, exported by
4342 the new $_siginfo convenience variable. The feature is currently
4343 implemented on linux ARM, i386 and amd64.
4345 * GDB can now display the VFP floating point registers and NEON vector
4346 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4347 can provide these registers (requires Linux 2.6.30 or later). Remote
4348 and simulator targets may also provide them.
4350 * New remote packets
4353 Search memory for a sequence of bytes.
4356 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4357 operation over reliable transport links. Use of this packet is
4358 controlled by the `set remote noack-packet' command.
4361 Kill the process with the specified process ID. Use this in preference
4362 to `k' when multiprocess protocol extensions are supported.
4365 Obtains additional operating system information
4369 Read or write additional signal information.
4371 * Removed remote protocol undocumented extension
4373 An undocumented extension to the remote protocol's `S' stop reply
4374 packet that permitted the stub to pass a process id was removed.
4375 Remote servers should use the `T' stop reply packet instead.
4377 * GDB now supports multiple function calling conventions according to the
4378 DWARF-2 DW_AT_calling_convention function attribute.
4380 * The SH target utilizes the aforementioned change to distinguish between gcc
4381 and Renesas calling convention. It also adds the new CLI commands
4382 `set/show sh calling-convention'.
4384 * GDB can now read compressed debug sections, as produced by GNU gold
4385 with the --compress-debug-sections=zlib flag.
4387 * 64-bit core files are now supported on AIX.
4389 * Thread switching is now supported on Tru64.
4391 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4392 which will be allocated using malloc later in program execution.
4394 * The qXfer:libraries:read remote protocol packet now allows passing a
4395 list of section offsets.
4397 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4398 conditions handling signals delivered during attach or thread creation
4399 have also been fixed.
4401 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4402 From the user's standpoint, all unqualified instances of True and False
4403 are treated as the standard definitions, regardless of context.
4405 * GDB now parses C++ symbol and type names more flexibly. For
4408 template<typename T> class C { };
4411 GDB will now correctly handle all of:
4413 ptype C<char const *>
4414 ptype C<char const*>
4415 ptype C<const char *>
4416 ptype C<const char*>
4418 * New features in the GDB remote stub, gdbserver
4420 - The "--wrapper" command-line argument tells gdbserver to use a
4421 wrapper program to launch programs for debugging.
4423 - On PowerPC and S/390 targets, it is now possible to use a single
4424 gdbserver executable to debug both 32-bit and 64-bit programs.
4425 (This requires gdbserver itself to be built as a 64-bit executable.)
4427 - gdbserver uses the new noack protocol mode for TCP connections to
4428 reduce communications latency, if also supported and enabled in GDB.
4430 - Support for the sparc64-linux-gnu target is now included in
4433 - The amd64-linux build of gdbserver now supports debugging both
4434 32-bit and 64-bit programs.
4436 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4437 now support hardware watchpoints, and will use them automatically
4442 GDB now has support for scripting using Python. Whether this is
4443 available is determined at configure time.
4445 New GDB commands can now be written in Python.
4447 * Ada tasking support
4449 Ada tasks can now be inspected in GDB. The following commands have
4453 Print the list of Ada tasks.
4455 Print detailed information about task number N.
4457 Print the task number of the current task.
4459 Switch the context of debugging to task number N.
4461 * Support for user-defined prefixed commands. The "define" command can
4462 add new commands to existing prefixes, e.g. "target".
4464 * Multi-inferior, multi-process debugging.
4466 GDB now has generalized support for multi-inferior debugging. See
4467 "Debugging Multiple Inferiors" in the manual for more information.
4468 Although availability still depends on target support, the command
4469 set is more uniform now. The GNU/Linux specific multi-forks support
4470 has been migrated to this new framework. This implied some user
4471 visible changes; see "New commands" and also "Removed commands"
4474 * Target descriptions can now describe the target OS ABI. See the
4475 "Target Description Format" section in the user manual for more
4478 * Target descriptions can now describe "compatible" architectures
4479 to indicate that the target can execute applications for a different
4480 architecture in addition to those for the main target architecture.
4481 See the "Target Description Format" section in the user manual for
4484 * Multi-architecture debugging.
4486 GDB now includes general supports for debugging applications on
4487 hybrid systems that use more than one single processor architecture
4488 at the same time. Each such hybrid architecture still requires
4489 specific support to be added. The only hybrid architecture supported
4490 in this version of GDB is the Cell Broadband Engine.
4492 * GDB now supports integrated debugging of Cell/B.E. applications that
4493 use both the PPU and SPU architectures. To enable support for hybrid
4494 Cell/B.E. debugging, you need to configure GDB to support both the
4495 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4496 --enable-targets configure option.
4498 * Non-stop mode debugging.
4500 For some targets, GDB now supports an optional mode of operation in
4501 which you can examine stopped threads while other threads continue
4502 to execute freely. This is referred to as non-stop mode, with the
4503 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4504 section in the user manual for more information.
4506 To be able to support remote non-stop debugging, a remote stub needs
4507 to implement the non-stop mode remote protocol extensions, as
4508 described in the "Remote Non-Stop" section of the user manual. The
4509 GDB remote stub, gdbserver, has been adjusted to support these
4510 extensions on linux targets.
4512 * New commands (for set/show, see "New options" below)
4514 catch syscall [NAME(S) | NUMBER(S)]
4515 Catch system calls. Arguments, which should be names of system
4516 calls or their numbers, mean catch only those syscalls. Without
4517 arguments, every syscall will be caught. When the inferior issues
4518 any of the specified syscalls, GDB will stop and announce the system
4519 call, both when it is called and when its call returns. This
4520 feature is currently available with a native GDB running on the
4521 Linux Kernel, under the following architectures: x86, x86_64,
4522 PowerPC and PowerPC64.
4524 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4526 Search memory for a sequence of bytes.
4528 maint set python print-stack
4529 maint show python print-stack
4530 Show a stack trace when an error is encountered in a Python script.
4533 Invoke CODE by passing it to the Python interpreter.
4538 These allow macros to be defined, undefined, and listed
4542 Show operating system information about processes.
4545 List the inferiors currently under GDB's control.
4548 Switch focus to inferior number NUM.
4551 Detach from inferior number NUM.
4554 Kill inferior number NUM.
4558 set spu stop-on-load
4559 show spu stop-on-load
4560 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4562 set spu auto-flush-cache
4563 show spu auto-flush-cache
4564 Control whether to automatically flush the software-managed cache
4565 during Cell/B.E. debugging.
4567 set sh calling-convention
4568 show sh calling-convention
4569 Control the calling convention used when calling SH target functions.
4572 show debug timestamp
4573 Control display of timestamps with GDB debugging output.
4575 set disassemble-next-line
4576 show disassemble-next-line
4577 Control display of disassembled source lines or instructions when
4580 set remote noack-packet
4581 show remote noack-packet
4582 Set/show the use of remote protocol QStartNoAckMode packet. See above
4583 under "New remote packets."
4585 set remote query-attached-packet
4586 show remote query-attached-packet
4587 Control use of remote protocol `qAttached' (query-attached) packet.
4589 set remote read-siginfo-object
4590 show remote read-siginfo-object
4591 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4594 set remote write-siginfo-object
4595 show remote write-siginfo-object
4596 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4599 set remote reverse-continue
4600 show remote reverse-continue
4601 Control use of remote protocol 'bc' (reverse-continue) packet.
4603 set remote reverse-step
4604 show remote reverse-step
4605 Control use of remote protocol 'bs' (reverse-step) packet.
4607 set displaced-stepping
4608 show displaced-stepping
4609 Control displaced stepping mode. Displaced stepping is a way to
4610 single-step over breakpoints without removing them from the debuggee.
4611 Also known as "out-of-line single-stepping".
4614 show debug displaced
4615 Control display of debugging info for displaced stepping.
4617 maint set internal-error
4618 maint show internal-error
4619 Control what GDB does when an internal error is detected.
4621 maint set internal-warning
4622 maint show internal-warning
4623 Control what GDB does when an internal warning is detected.
4628 Use a wrapper program to launch programs for debugging.
4630 set multiple-symbols (all|ask|cancel)
4631 show multiple-symbols
4632 The value of this variable can be changed to adjust the debugger behavior
4633 when an expression or a breakpoint location contains an ambiguous symbol
4634 name (an overloaded function name, for instance).
4636 set breakpoint always-inserted
4637 show breakpoint always-inserted
4638 Keep breakpoints always inserted in the target, as opposed to inserting
4639 them when resuming the target, and removing them when the target stops.
4640 This option can improve debugger performance on slow remote targets.
4642 set arm fallback-mode (arm|thumb|auto)
4643 show arm fallback-mode
4644 set arm force-mode (arm|thumb|auto)
4646 These commands control how ARM GDB determines whether instructions
4647 are ARM or Thumb. The default for both settings is auto, which uses
4648 the current CPSR value for instructions without symbols; previous
4649 versions of GDB behaved as if "set arm fallback-mode arm".
4651 set disable-randomization
4652 show disable-randomization
4653 Standalone programs run with the virtual address space randomization enabled
4654 by default on some platforms. This option keeps the addresses stable across
4655 multiple debugging sessions.
4659 Control whether other threads are stopped or not when some thread hits
4664 Requests that asynchronous execution is enabled in the target, if available.
4665 In this case, it's possible to resume target in the background, and interact
4666 with GDB while the target is running. "show target-async" displays the
4667 current state of asynchronous execution of the target.
4669 set target-wide-charset
4670 show target-wide-charset
4671 The target-wide-charset is the name of the character set that GDB
4672 uses when printing characters whose type is wchar_t.
4674 set tcp auto-retry (on|off)
4676 set tcp connect-timeout
4677 show tcp connect-timeout
4678 These commands allow GDB to retry failed TCP connections to a remote stub
4679 with a specified timeout period; this is useful if the stub is launched
4680 in parallel with GDB but may not be ready to accept connections immediately.
4682 set libthread-db-search-path
4683 show libthread-db-search-path
4684 Control list of directories which GDB will search for appropriate
4687 set schedule-multiple (on|off)
4688 show schedule-multiple
4689 Allow GDB to resume all threads of all processes or only threads of
4690 the current process.
4694 Use more aggressive caching for accesses to the stack. This improves
4695 performance of remote debugging (particularly backtraces) without
4696 affecting correctness.
4698 set interactive-mode (on|off|auto)
4699 show interactive-mode
4700 Control whether GDB runs in interactive mode (on) or not (off).
4701 When in interactive mode, GDB waits for the user to answer all
4702 queries. Otherwise, GDB does not wait and assumes the default
4703 answer. When set to auto (the default), GDB determines which
4704 mode to use based on the stdin settings.
4709 For program forks, this is replaced by the new more generic `info
4710 inferiors' command. To list checkpoints, you can still use the
4711 `info checkpoints' command, which was an alias for the `info forks'
4715 Replaced by the new `inferior' command. To switch between
4716 checkpoints, you can still use the `restart' command, which was an
4717 alias for the `fork' command.
4720 This is removed, since some targets don't have a notion of
4721 processes. To switch between processes, you can still use the
4722 `inferior' command using GDB's own inferior number.
4725 For program forks, this is replaced by the new more generic `kill
4726 inferior' command. To delete a checkpoint, you can still use the
4727 `delete checkpoint' command, which was an alias for the `delete
4731 For program forks, this is replaced by the new more generic `detach
4732 inferior' command. To detach a checkpoint, you can still use the
4733 `detach checkpoint' command, which was an alias for the `detach
4736 * New native configurations
4738 x86/x86_64 Darwin i[34567]86-*-darwin*
4740 x86_64 MinGW x86_64-*-mingw*
4744 Lattice Mico32 lm32-*
4745 x86 DICOS i[34567]86-*-dicos*
4746 x86_64 DICOS x86_64-*-dicos*
4749 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4750 (mingw32ce) debugging.
4756 These commands were actually not implemented on any target.
4758 *** Changes in GDB 6.8
4760 * New native configurations
4762 NetBSD/hppa hppa*-*netbsd*
4763 Xtensa GNU/Linux xtensa*-*-linux*
4767 NetBSD/hppa hppa*-*-netbsd*
4768 Xtensa GNU/Linux xtensa*-*-linux*
4770 * Change in command line behavior -- corefiles vs. process ids.
4772 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4773 attaching to process NUMBER fails, GDB no longer attempts to open a
4774 core file named NUMBER. Attaching to a program using the -c option
4775 is no longer supported. Instead, use the '-p' or '--pid' options.
4777 * GDB can now be built as a native debugger for debugging Windows x86
4778 (mingw32) Portable Executable (PE) programs.
4780 * Pending breakpoints no longer change their number when their address
4783 * GDB now supports breakpoints with multiple locations,
4784 including breakpoints on C++ constructors, inside C++ templates,
4785 and in inlined functions.
4787 * GDB's ability to debug optimized code has been improved. GDB more
4788 accurately identifies function bodies and lexical blocks that occupy
4789 more than one contiguous range of addresses.
4791 * Target descriptions can now describe registers for PowerPC.
4793 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4794 registers on PowerPC targets.
4796 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4797 targets even when the libthread_db library is not available.
4799 * The GDB remote stub, gdbserver, now supports the new file transfer
4800 commands (remote put, remote get, and remote delete).
4802 * The GDB remote stub, gdbserver, now supports run and attach in
4803 extended-remote mode.
4805 * hppa*64*-*-hpux11* target broken
4806 The debugger is unable to start a program and fails with the following
4807 error: "Error trying to get information about dynamic linker".
4808 The gdb-6.7 release is also affected.
4810 * GDB now supports the --enable-targets= configure option to allow
4811 building a single GDB executable that supports multiple remote
4812 target architectures.
4814 * GDB now supports debugging C and C++ programs which use the
4815 Decimal Floating Point extension. In addition, the PowerPC target
4816 now has a set of pseudo-registers to inspect decimal float values
4817 stored in two consecutive float registers.
4819 * The -break-insert MI command can optionally create pending
4822 * Improved support for debugging Ada
4823 Many improvements to the Ada language support have been made. These
4825 - Better support for Ada2005 interface types
4826 - Improved handling of arrays and slices in general
4827 - Better support for Taft-amendment types
4828 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4830 - Improved command completion in Ada
4833 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4838 set print frame-arguments (all|scalars|none)
4839 show print frame-arguments
4840 The value of this variable can be changed to control which argument
4841 values should be printed by the debugger when displaying a frame.
4846 Transfer files to and from a remote target, and delete remote files.
4853 Transfer files to and from a remote target, and delete remote files.
4855 * New remote packets
4862 Open, close, read, write, and delete files on the remote system.
4865 Attach to an existing process on the remote system, in extended-remote
4869 Run a new process on the remote system, in extended-remote mode.
4871 *** Changes in GDB 6.7
4873 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4874 bfd, libiberty and opcodes, as revealed by static analysis donated by
4875 Coverity, Inc. (http://scan.coverity.com).
4877 * When looking up multiply-defined global symbols, GDB will now prefer the
4878 symbol definition in the current shared library if it was built using the
4879 -Bsymbolic linker option.
4881 * When the Text User Interface (TUI) is not configured, GDB will now
4882 recognize the -tui command-line option and print a message that the TUI
4885 * The GDB remote stub, gdbserver, now has lower overhead for high
4886 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4888 * GDB for MIPS targets now autodetects whether a remote target provides
4889 32-bit or 64-bit register values.
4891 * Support for C++ member pointers has been improved.
4893 * GDB now understands XML target descriptions, which specify the
4894 target's overall architecture. GDB can read a description from
4895 a local file or over the remote serial protocol.
4897 * Vectors of single-byte data use a new integer type which is not
4898 automatically displayed as character or string data.
4900 * The /s format now works with the print command. It displays
4901 arrays of single-byte integers and pointers to single-byte integers
4904 * Target descriptions can now describe target-specific registers,
4905 for architectures which have implemented the support (currently
4906 only ARM, M68K, and MIPS).
4908 * GDB and the GDB remote stub, gdbserver, now support the XScale
4911 * The GDB remote stub, gdbserver, has been updated to support
4912 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4913 has been rewritten to use the standard GDB remote protocol.
4915 * GDB can now step into C++ functions which are called through thunks.
4917 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4919 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4920 layout. It also supports a TextSeg= and DataSeg= response when only
4921 segment base addresses (rather than offsets) are available.
4923 * The /i format now outputs any trailing branch delay slot instructions
4924 immediately following the last instruction within the count specified.
4926 * The GDB remote protocol "T" stop reply packet now supports a
4927 "library" response. Combined with the new "qXfer:libraries:read"
4928 packet, this response allows GDB to debug shared libraries on targets
4929 where the operating system manages the list of loaded libraries (e.g.
4930 Windows and SymbianOS).
4932 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4933 (DLLs) on Windows and Windows CE targets.
4935 * GDB now supports a faster verification that a .debug file matches its binary
4936 according to its build-id signature, if the signature is present.
4942 Enable or disable hardware flow control (RTS/CTS) on the serial port
4943 when debugging using remote targets.
4945 set mem inaccessible-by-default
4946 show mem inaccessible-by-default
4947 If the target supplies a memory map, for instance via the remote
4948 protocol's "qXfer:memory-map:read" packet, setting this variable
4949 prevents GDB from accessing memory outside the memory map. This
4950 is useful for targets with memory mapped registers or which react
4951 badly to accesses of unmapped address space.
4953 set breakpoint auto-hw
4954 show breakpoint auto-hw
4955 If the target supplies a memory map, for instance via the remote
4956 protocol's "qXfer:memory-map:read" packet, setting this variable
4957 lets GDB use hardware breakpoints automatically for memory regions
4958 where it can not use software breakpoints. This covers both the
4959 "break" command and internal breakpoints used for other commands
4960 including "next" and "finish".
4963 catch exception unhandled
4964 Stop the program execution when Ada exceptions are raised.
4967 Stop the program execution when an Ada assertion failed.
4971 Set an alternate system root for target files. This is a more
4972 general version of "set solib-absolute-prefix", which is now
4973 an alias to "set sysroot".
4976 Provide extended SPU facility status information. This set of
4977 commands is available only when debugging the Cell/B.E. SPU
4980 * New native configurations
4982 OpenBSD/sh sh*-*openbsd*
4985 unset tdesc filename
4987 Use the specified local file as an XML target description, and do
4988 not query the target for its built-in description.
4992 OpenBSD/sh sh*-*-openbsd*
4993 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4994 Toshiba Media Processor mep-elf
4996 * New remote packets
4999 Ignore the specified signals; pass them directly to the debugged program
5000 without stopping other threads or reporting them to GDB.
5002 qXfer:features:read:
5003 Read an XML target description from the target, which describes its
5008 Read or write contents of an spufs file on the target system. These
5009 packets are available only on the Cell/B.E. SPU architecture.
5011 qXfer:libraries:read:
5012 Report the loaded shared libraries. Combined with new "T" packet
5013 response, this packet allows GDB to debug shared libraries on
5014 targets where the operating system manages the list of loaded
5015 libraries (e.g. Windows and SymbianOS).
5019 Support for these obsolete configurations has been removed.
5027 i[34567]86-*-lynxos*
5028 i[34567]86-*-netware*
5029 i[34567]86-*-sco3.2v5*
5030 i[34567]86-*-sco3.2v4*
5032 i[34567]86-*-sysv4.2*
5035 i[34567]86-*-unixware2*
5036 i[34567]86-*-unixware*
5045 * Other removed features
5052 Various m68k-only ROM monitors.
5059 Various Renesas ROM monitors and debugging interfaces for SH and
5064 Support for a Macraigor serial interface to on-chip debugging.
5065 GDB does not directly support the newer parallel or USB
5070 A debug information format. The predecessor to DWARF 2 and
5071 DWARF 3, which are still supported.
5073 Support for the HP aCC compiler on HP-UX/PA-RISC
5075 SOM-encapsulated symbolic debugging information, automatic
5076 invocation of pxdb, and the aCC custom C++ ABI. This does not
5077 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5078 with aCC can still be debugged on an assembly level.
5080 MIPS ".pdr" sections
5082 A MIPS-specific format used to describe stack frame layout
5083 in debugging information.
5087 GDB could work with an older version of Guile to debug
5088 the interpreter and Scheme programs running in it.
5090 set mips stack-arg-size
5091 set mips saved-gpreg-size
5093 Use "set mips abi" to control parameter passing for MIPS.
5095 *** Changes in GDB 6.6
5100 Cell Broadband Engine SPU spu-elf
5102 * GDB can now be configured as a cross-debugger targeting native Windows
5103 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5104 running on a Windows system over TCP/IP to debug Windows programs.
5106 * The GDB remote stub, gdbserver, has been updated to support Windows and
5107 Cygwin debugging. Both single-threaded and multi-threaded programs are
5110 * The "set trust-readonly-sections" command works again. This command was
5111 broken in GDB 6.3, 6.4, and 6.5.
5113 * The "load" command now supports writing to flash memory, if the remote
5114 stub provides the required support.
5116 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5117 longer requires symbolic debug information (e.g. DWARF-2).
5122 unset substitute-path
5123 show substitute-path
5124 Manage a list of substitution rules that GDB uses to rewrite the name
5125 of the directories where the sources are located. This can be useful
5126 for instance when the sources were moved to a different location
5127 between compilation and debugging.
5131 Print each CLI command as it is executed. Each command is prefixed with
5132 a number of `+' symbols representing the nesting depth.
5133 The source command now has a `-v' option to enable the same feature.
5137 The ARM Demon monitor support (RDP protocol, "target rdp").
5139 Kernel Object Display, an embedded debugging feature which only worked with
5140 an obsolete version of Cisco IOS.
5142 The 'set download-write-size' and 'show download-write-size' commands.
5144 * New remote packets
5147 Tell a stub about GDB client features, and request remote target features.
5148 The first feature implemented is PacketSize, which allows the target to
5149 specify the size of packets it can handle - to minimize the number of
5150 packets required and improve performance when connected to a remote
5154 Fetch an OS auxilliary vector from the remote stub. This packet is a
5155 more efficient replacement for qPart:auxv:read.
5157 qXfer:memory-map:read:
5158 Fetch a memory map from the remote stub, including information about
5159 RAM, ROM, and flash memory devices.
5164 Erase and program a flash memory device.
5166 * Removed remote packets
5169 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5170 used it, and only gdbserver implemented it.
5172 *** Changes in GDB 6.5
5176 Renesas M32C/M16C m32c-elf
5178 Morpho Technologies ms1 ms1-elf
5182 init-if-undefined Initialize a convenience variable, but
5183 only if it doesn't already have a value.
5185 The following commands are presently only implemented for native GNU/Linux:
5187 checkpoint Save a snapshot of the program state.
5189 restart <n> Return the program state to a
5190 previously saved state.
5192 info checkpoints List currently saved checkpoints.
5194 delete-checkpoint <n> Delete a previously saved checkpoint.
5196 set|show detach-on-fork Tell gdb whether to detach from a newly
5197 forked process, or to keep debugging it.
5199 info forks List forks of the user program that
5200 are available to be debugged.
5202 fork <n> Switch to debugging one of several
5203 forks of the user program that are
5204 available to be debugged.
5206 delete-fork <n> Delete a fork from the list of forks
5207 that are available to be debugged (and
5208 kill the forked process).
5210 detach-fork <n> Delete a fork from the list of forks
5211 that are available to be debugged (and
5212 allow the process to continue).
5216 Morpho Technologies ms2 ms1-elf
5218 * Improved Windows host support
5220 GDB now builds as a cross debugger hosted on i686-mingw32, including
5221 native console support, and remote communications using either
5222 network sockets or serial ports.
5224 * Improved Modula-2 language support
5226 GDB can now print most types in the Modula-2 syntax. This includes:
5227 basic types, set types, record types, enumerated types, range types,
5228 pointer types and ARRAY types. Procedure var parameters are correctly
5229 printed and hexadecimal addresses and character constants are also
5230 written in the Modula-2 syntax. Best results can be obtained by using
5231 GNU Modula-2 together with the -gdwarf-2 command line option.
5235 The ARM rdi-share module.
5237 The Netware NLM debug server.
5239 *** Changes in GDB 6.4
5241 * New native configurations
5243 OpenBSD/arm arm*-*-openbsd*
5244 OpenBSD/mips64 mips64-*-openbsd*
5248 Morpho Technologies ms1 ms1-elf
5250 * New command line options
5252 --batch-silent As for --batch, but totally silent.
5253 --return-child-result The debugger will exist with the same value
5254 the child (debugged) program exited with.
5255 --eval-command COMMAND, -ex COMMAND
5256 Execute a single GDB CLI command. This may be
5257 specified multiple times and in conjunction
5258 with the --command (-x) option.
5260 * Deprecated commands removed
5262 The following commands, that were deprecated in 2000, have been
5266 set|show arm disassembly-flavor set|show arm disassembler
5267 othernames set arm disassembler
5268 set|show remotedebug set|show debug remote
5269 set|show archdebug set|show debug arch
5270 set|show eventdebug set|show debug event
5273 * New BSD user-level threads support
5275 It is now possible to debug programs using the user-level threads
5276 library on OpenBSD and FreeBSD. Currently supported (target)
5279 FreeBSD/amd64 x86_64-*-freebsd*
5280 FreeBSD/i386 i386-*-freebsd*
5281 OpenBSD/i386 i386-*-openbsd*
5283 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5284 are not yet supported.
5286 * New support for Matsushita MN10300 w/sim added
5287 (Work in progress). mn10300-elf.
5289 * REMOVED configurations and files
5291 VxWorks and the XDR protocol *-*-vxworks
5292 Motorola MCORE mcore-*-*
5293 National Semiconductor NS32000 ns32k-*-*
5295 * New "set print array-indexes" command
5297 After turning this setting "on", GDB prints the index of each element
5298 when displaying arrays. The default is "off" to preserve the previous
5301 * VAX floating point support
5303 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5305 * User-defined command support
5307 In addition to using $arg0..$arg9 for argument passing, it is now possible
5308 to use $argc to determine now many arguments have been passed. See the
5309 section on user-defined commands in the user manual for more information.
5311 *** Changes in GDB 6.3:
5313 * New command line option
5315 GDB now accepts -l followed by a number to set the timeout for remote
5318 * GDB works with GCC -feliminate-dwarf2-dups
5320 GDB now supports a more compact representation of DWARF-2 debug
5321 information using DW_FORM_ref_addr references. These are produced
5322 by GCC with the option -feliminate-dwarf2-dups and also by some
5323 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5324 to use -feliminate-dwarf2-dups.
5326 * Internationalization
5328 When supported by the host system, GDB will be built with
5329 internationalization (libintl). The task of marking up the sources is
5330 continued, we're looking forward to our first translation.
5334 Initial support for debugging programs compiled with the GNAT
5335 implementation of the Ada programming language has been integrated
5336 into GDB. In this release, support is limited to expression evaluation.
5338 * New native configurations
5340 GNU/Linux/m32r m32r-*-linux-gnu
5344 GDB's remote protocol now includes support for the 'p' packet. This
5345 packet is used to fetch individual registers from a remote inferior.
5347 * END-OF-LIFE registers[] compatibility module
5349 GDB's internal register infrastructure has been completely rewritten.
5350 The new infrastructure making possible the implementation of key new
5351 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5354 GDB 6.3 will be the last release to include the registers[]
5355 compatibility module that allowed out-of-date configurations to
5356 continue to work. This change directly impacts the following
5366 powerpc bdm protocol
5368 Unless there is activity to revive these configurations, they will be
5369 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5371 * OBSOLETE configurations and files
5373 Configurations that have been declared obsolete in this release have
5374 been commented out. Unless there is activity to revive these
5375 configurations, the next release of GDB will have their sources
5376 permanently REMOVED.
5385 *** Changes in GDB 6.2.1:
5387 * MIPS `break main; run' gave an heuristic-fence-post warning
5389 When attempting to run even a simple program, a warning about
5390 heuristic-fence-post being hit would be reported. This problem has
5393 * MIPS IRIX 'long double' crashed GDB
5395 When examining a long double variable, GDB would get a segmentation
5396 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5397 IRIX long double values).
5401 A bug in the VAX stack code was causing problems with the "next"
5402 command. This problem has been fixed.
5404 *** Changes in GDB 6.2:
5406 * Fix for ``many threads''
5408 On GNU/Linux systems that use the NPTL threads library, a program
5409 rapidly creating and deleting threads would confuse GDB leading to the
5412 ptrace: No such process.
5413 thread_db_get_info: cannot get thread info: generic error
5415 This problem has been fixed.
5417 * "-async" and "-noasync" options removed.
5419 Support for the broken "-noasync" option has been removed (it caused
5422 * New ``start'' command.
5424 This command runs the program until the beginning of the main procedure.
5426 * New BSD Kernel Data Access Library (libkvm) interface
5428 Using ``target kvm'' it is now possible to debug kernel core dumps and
5429 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5430 platforms. Currently supported (native-only) configurations are:
5432 FreeBSD/amd64 x86_64-*-freebsd*
5433 FreeBSD/i386 i?86-*-freebsd*
5434 NetBSD/i386 i?86-*-netbsd*
5435 NetBSD/m68k m68*-*-netbsd*
5436 NetBSD/sparc sparc-*-netbsd*
5437 OpenBSD/amd64 x86_64-*-openbsd*
5438 OpenBSD/i386 i?86-*-openbsd*
5439 OpenBSD/m68k m68*-openbsd*
5440 OpenBSD/sparc sparc-*-openbsd*
5442 * Signal trampoline code overhauled
5444 Many generic problems with GDB's signal handling code have been fixed.
5445 These include: backtraces through non-contiguous stacks; recognition
5446 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5447 call; backtrace through a signal trampoline; step into and out of
5448 signal handlers; and single-stepping in the signal trampoline.
5450 Please note that kernel bugs are a limiting factor here. These
5451 features have been shown to work on an s390 GNU/Linux system that
5452 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5454 * Cygwin support for DWARF 2 added.
5456 * New native configurations
5458 GNU/Linux/hppa hppa*-*-linux*
5459 OpenBSD/hppa hppa*-*-openbsd*
5460 OpenBSD/m68k m68*-*-openbsd*
5461 OpenBSD/m88k m88*-*-openbsd*
5462 OpenBSD/powerpc powerpc-*-openbsd*
5463 NetBSD/vax vax-*-netbsd*
5464 OpenBSD/vax vax-*-openbsd*
5466 * END-OF-LIFE frame compatibility module
5468 GDB's internal frame infrastructure has been completely rewritten.
5469 The new infrastructure making it possible to support key new features
5470 including DWARF 2 Call Frame Information. To aid in the task of
5471 migrating old configurations to this new infrastructure, a
5472 compatibility module, that allowed old configurations to continue to
5473 work, was also included.
5475 GDB 6.2 will be the last release to include this frame compatibility
5476 module. This change directly impacts the following configurations:
5486 Unless there is activity to revive these configurations, they will be
5487 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5489 * REMOVED configurations and files
5491 Sun 3, running SunOS 3 m68*-*-sunos3*
5492 Sun 3, running SunOS 4 m68*-*-sunos4*
5493 Sun 2, running SunOS 3 m68000-*-sunos3*
5494 Sun 2, running SunOS 4 m68000-*-sunos4*
5495 Motorola 680x0 running LynxOS m68*-*-lynxos*
5496 AT&T 3b1/Unix pc m68*-att-*
5497 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5498 decstation mips-dec-* mips-little-*
5499 riscos mips-*-riscos* mips-*-sysv*
5500 sonymips mips-sony-*
5501 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5503 *** Changes in GDB 6.1.1:
5505 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5507 The TUI (Text-mode User Interface) is now built as part of a default
5508 GDB configuration. It is enabled by either selecting the TUI with the
5509 command line option "-i=tui" or by running the separate "gdbtui"
5510 program. For more information on the TUI, see the manual "Debugging
5513 * Pending breakpoint support (also included in GDB 6.1)
5515 Support has been added to allow you to specify breakpoints in shared
5516 libraries that have not yet been loaded. If a breakpoint location
5517 cannot be found, and the "breakpoint pending" option is set to auto,
5518 GDB queries you if you wish to make the breakpoint pending on a future
5519 shared-library load. If and when GDB resolves the breakpoint symbol,
5520 the pending breakpoint is removed as one or more regular breakpoints
5523 Pending breakpoints are very useful for GCJ Java debugging.
5525 * Fixed ISO-C build problems
5527 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5528 non ISO-C code that stopped them being built using a more strict ISO-C
5529 compiler (e.g., IBM's C compiler).
5531 * Fixed build problem on IRIX 5
5533 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5534 wasn't able to compile compile on an IRIX 5 system.
5536 * Added execute permission to gdb/gdbserver/configure
5538 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5539 permission. This bug would cause configure to fail on a number of
5540 systems (Solaris, IRIX). Ref: server/519.
5542 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5544 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5545 has been updated to use constant array sizes.
5547 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5549 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5550 its generated DWARF Call Frame Info. This encoding was causing GDB to
5551 panic, that panic has been fixed. Ref: gdb/1628.
5553 * Fixed a problem when examining parameters in shared library code.
5555 When examining parameters in optimized shared library code generated
5556 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5557 not available''. GDB now correctly displays the variable's value.
5559 *** Changes in GDB 6.1:
5561 * Removed --with-mmalloc
5563 Support for the mmalloc memory manager has been removed, as it
5564 conflicted with the internal gdb byte cache.
5566 * Changes in AMD64 configurations
5568 The AMD64 target now includes the %cs and %ss registers. As a result
5569 the AMD64 remote protocol has changed; this affects the floating-point
5570 and SSE registers. If you rely on those registers for your debugging,
5571 you should upgrade gdbserver on the remote side.
5573 * Revised SPARC target
5575 The SPARC target has been completely revised, incorporating the
5576 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5577 support for LynxOS and SunOS 4 has been dropped. Calling functions
5578 from within GDB on operating systems with a non-executable stack
5579 (Solaris, OpenBSD) now works.
5583 GDB has a new C++ demangler which does a better job on the mangled
5584 names generated by current versions of g++. It also runs faster, so
5585 with this and other changes gdb should now start faster on large C++
5588 * DWARF 2 Location Expressions
5590 GDB support for location expressions has been extended to support function
5591 arguments and frame bases. Older versions of GDB could crash when they
5594 * C++ nested types and namespaces
5596 GDB's support for nested types and namespaces in C++ has been
5597 improved, especially if you use the DWARF 2 debugging format. (This
5598 is the default for recent versions of GCC on most platforms.)
5599 Specifically, if you have a class "Inner" defined within a class or
5600 namespace "Outer", then GDB realizes that the class's name is
5601 "Outer::Inner", not simply "Inner". This should greatly reduce the
5602 frequency of complaints about not finding RTTI symbols. In addition,
5603 if you are stopped at inside of a function defined within a namespace,
5604 GDB modifies its name lookup accordingly.
5606 * New native configurations
5608 NetBSD/amd64 x86_64-*-netbsd*
5609 OpenBSD/amd64 x86_64-*-openbsd*
5610 OpenBSD/alpha alpha*-*-openbsd*
5611 OpenBSD/sparc sparc-*-openbsd*
5612 OpenBSD/sparc64 sparc64-*-openbsd*
5614 * New debugging protocols
5616 M32R with SDI protocol m32r-*-elf*
5618 * "set prompt-escape-char" command deleted.
5620 The command "set prompt-escape-char" has been deleted. This command,
5621 and its very obscure effect on GDB's prompt, was never documented,
5622 tested, nor mentioned in the NEWS file.
5624 * OBSOLETE configurations and files
5626 Configurations that have been declared obsolete in this release have
5627 been commented out. Unless there is activity to revive these
5628 configurations, the next release of GDB will have their sources
5629 permanently REMOVED.
5631 Sun 3, running SunOS 3 m68*-*-sunos3*
5632 Sun 3, running SunOS 4 m68*-*-sunos4*
5633 Sun 2, running SunOS 3 m68000-*-sunos3*
5634 Sun 2, running SunOS 4 m68000-*-sunos4*
5635 Motorola 680x0 running LynxOS m68*-*-lynxos*
5636 AT&T 3b1/Unix pc m68*-att-*
5637 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5638 decstation mips-dec-* mips-little-*
5639 riscos mips-*-riscos* mips-*-sysv*
5640 sonymips mips-sony-*
5641 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5643 * REMOVED configurations and files
5645 SGI Irix-4.x mips-sgi-irix4 or iris4
5646 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5647 Z8000 simulator z8k-zilog-none or z8ksim
5648 Matsushita MN10200 w/simulator mn10200-*-*
5649 H8/500 simulator h8500-hitachi-hms or h8500hms
5650 HP/PA running BSD hppa*-*-bsd*
5651 HP/PA running OSF/1 hppa*-*-osf*
5652 HP/PA Pro target hppa*-*-pro*
5653 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5654 386BSD i[3456]86-*-bsd*
5655 Sequent family i[3456]86-sequent-sysv4*
5656 i[3456]86-sequent-sysv*
5657 i[3456]86-sequent-bsd*
5658 SPARC running LynxOS sparc-*-lynxos*
5659 SPARC running SunOS 4 sparc-*-sunos4*
5660 Tsqware Sparclet sparclet-*-*
5661 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5663 *** Changes in GDB 6.0:
5667 Support for debugging the Objective-C programming language has been
5668 integrated into GDB.
5670 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5672 DWARF 2's Call Frame Information makes available compiler generated
5673 information that more exactly describes the program's run-time stack.
5674 By using this information, GDB is able to provide more robust stack
5677 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5678 have been updated to use a new backtrace mechanism which includes
5679 DWARF 2 CFI support.
5683 GDB's remote protocol has been extended to include support for hosted
5684 file I/O (where the remote target uses GDB's file system). See GDB's
5685 remote protocol documentation for details.
5687 * All targets using the new architecture framework.
5689 All of GDB's targets have been updated to use the new internal
5690 architecture framework. The way is now open for future GDB releases
5691 to include cross-architecture native debugging support (i386 on amd64,
5694 * GNU/Linux's Thread Local Storage (TLS)
5696 GDB now includes support for for the GNU/Linux implementation of
5697 per-thread variables.
5699 * GNU/Linux's Native POSIX Thread Library (NPTL)
5701 GDB's thread code has been updated to work with either the new
5702 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5704 * Separate debug info.
5706 GDB, in conjunction with BINUTILS, now supports a mechanism for
5707 automatically loading debug information from a separate file. Instead
5708 of shipping full debug and non-debug versions of system libraries,
5709 system integrators can now instead ship just the stripped libraries
5710 and optional debug files.
5712 * DWARF 2 Location Expressions
5714 DWARF 2 Location Expressions allow the compiler to more completely
5715 describe the location of variables (even in optimized code) to the
5718 GDB now includes preliminary support for location expressions (support
5719 for DW_OP_piece is still missing).
5723 A number of long standing bugs that caused GDB to die while starting a
5724 Java application have been fixed. GDB's Java support is now
5725 considered "useable".
5727 * GNU/Linux support for fork, vfork, and exec.
5729 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5730 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5733 * GDB supports logging output to a file
5735 There are two new commands, "set logging" and "show logging", which can be
5736 used to capture GDB's output to a file.
5738 * The meaning of "detach" has changed for gdbserver
5740 The "detach" command will now resume the application, as documented. To
5741 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5744 * d10v, m68hc11 `regs' command deprecated
5746 The `info registers' command has been updated so that it displays the
5747 registers using a format identical to the old `regs' command.
5751 A new command, "maint set profile on/off", has been added. This command can
5752 be used to enable or disable profiling while running GDB, to profile a
5753 session or a set of commands. In addition there is a new configure switch,
5754 "--enable-profiling", which will cause GDB to be compiled with profiling
5755 data, for more informative profiling results.
5757 * Default MI syntax changed to "mi2".
5759 The default MI (machine interface) syntax, enabled by the command line
5760 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5761 "mi1", can be enabled by specifying the option "-i=mi1".
5763 Support for the original "mi0" syntax (included in GDB 5.0) has been
5766 Fix for gdb/192: removed extraneous space when displaying frame level.
5767 Fix for gdb/672: update changelist is now output in mi list format.
5768 Fix for gdb/702: a -var-assign that updates the value now shows up
5769 in a subsequent -var-update.
5771 * New native configurations.
5773 FreeBSD/amd64 x86_64-*-freebsd*
5775 * Multi-arched targets.
5777 HP/PA HPUX11 hppa*-*-hpux*
5778 Renesas M32R/D w/simulator m32r-*-elf*
5780 * OBSOLETE configurations and files
5782 Configurations that have been declared obsolete in this release have
5783 been commented out. Unless there is activity to revive these
5784 configurations, the next release of GDB will have their sources
5785 permanently REMOVED.
5787 Z8000 simulator z8k-zilog-none or z8ksim
5788 Matsushita MN10200 w/simulator mn10200-*-*
5789 H8/500 simulator h8500-hitachi-hms or h8500hms
5790 HP/PA running BSD hppa*-*-bsd*
5791 HP/PA running OSF/1 hppa*-*-osf*
5792 HP/PA Pro target hppa*-*-pro*
5793 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5794 Sequent family i[3456]86-sequent-sysv4*
5795 i[3456]86-sequent-sysv*
5796 i[3456]86-sequent-bsd*
5797 Tsqware Sparclet sparclet-*-*
5798 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5800 * REMOVED configurations and files
5803 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5804 IBM AIX PS/2 i[3456]86-*-aix
5805 i386 running Mach 3.0 i[3456]86-*-mach3*
5806 i386 running Mach i[3456]86-*-mach*
5807 i386 running OSF/1 i[3456]86-*osf1mk*
5808 HP/Apollo 68k Family m68*-apollo*-sysv*,
5810 m68*-hp-bsd*, m68*-hp-hpux*
5811 Argonaut Risc Chip (ARC) arc-*-*
5812 Mitsubishi D30V d30v-*-*
5813 Fujitsu FR30 fr30-*-elf*
5814 OS/9000 i[34]86-*-os9k
5815 I960 with MON960 i960-*-coff
5817 * MIPS $fp behavior changed
5819 The convenience variable $fp, for the MIPS, now consistently returns
5820 the address of the current frame's base. Previously, depending on the
5821 context, $fp could refer to either $sp or the current frame's base
5822 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5823 The GNU Source-Level Debugger''.
5825 *** Changes in GDB 5.3:
5827 * GNU/Linux shared library multi-threaded performance improved.
5829 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5830 `/proc', in preference to `ptrace' for memory reads. This may result
5831 in an improvement in the start-up time of multi-threaded, shared
5832 library applications when run under GDB. One GDB user writes: ``loads
5833 shared libs like mad''.
5835 * ``gdbserver'' now supports multi-threaded applications on some targets
5837 Support for debugging multi-threaded applications which use
5838 the GNU/Linux LinuxThreads package has been added for
5839 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5840 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5842 * GDB now supports C/C++ preprocessor macros.
5844 GDB now expands preprocessor macro invocations in C/C++ expressions,
5845 and provides various commands for showing macro definitions and how
5848 The new command `macro expand EXPRESSION' expands any macro
5849 invocations in expression, and shows the result.
5851 The new command `show macro MACRO-NAME' shows the definition of the
5852 macro named MACRO-NAME, and where it was defined.
5854 Most compilers don't include information about macros in the debugging
5855 information by default. In GCC 3.1, for example, you need to compile
5856 your program with the options `-gdwarf-2 -g3'. If the macro
5857 information is present in the executable, GDB will read it.
5859 * Multi-arched targets.
5861 DEC Alpha (partial) alpha*-*-*
5862 DEC VAX (partial) vax-*-*
5864 National Semiconductor NS32000 (partial) ns32k-*-*
5865 Motorola 68000 (partial) m68k-*-*
5866 Motorola MCORE mcore-*-*
5870 Fujitsu FRV architecture added by Red Hat frv*-*-*
5873 * New native configurations
5875 Alpha NetBSD alpha*-*-netbsd*
5876 SH NetBSD sh*-*-netbsdelf*
5877 MIPS NetBSD mips*-*-netbsd*
5878 UltraSPARC NetBSD sparc64-*-netbsd*
5880 * OBSOLETE configurations and files
5882 Configurations that have been declared obsolete in this release have
5883 been commented out. Unless there is activity to revive these
5884 configurations, the next release of GDB will have their sources
5885 permanently REMOVED.
5887 Mitsubishi D30V d30v-*-*
5888 OS/9000 i[34]86-*-os9k
5889 IBM AIX PS/2 i[3456]86-*-aix
5890 Fujitsu FR30 fr30-*-elf*
5891 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5892 Argonaut Risc Chip (ARC) arc-*-*
5893 i386 running Mach 3.0 i[3456]86-*-mach3*
5894 i386 running Mach i[3456]86-*-mach*
5895 i386 running OSF/1 i[3456]86-*osf1mk*
5896 HP/Apollo 68k Family m68*-apollo*-sysv*,
5898 m68*-hp-bsd*, m68*-hp-hpux*
5899 I960 with MON960 i960-*-coff
5901 * OBSOLETE languages
5903 CHILL, a Pascal like language used by telecommunications companies.
5905 * REMOVED configurations and files
5907 AMD 29k family via UDI a29k-amd-udi, udi29k
5908 A29K VxWorks a29k-*-vxworks
5909 AMD 29000 embedded, using EBMON a29k-none-none
5910 AMD 29000 embedded with COFF a29k-none-coff
5911 AMD 29000 embedded with a.out a29k-none-aout
5913 testsuite/gdb.hp/gdb.threads-hp/ directory
5915 * New command "set max-user-call-depth <nnn>"
5917 This command allows the user to limit the call depth of user-defined
5918 commands. The default is 1024.
5920 * Changes in FreeBSD/i386 native debugging.
5922 Support for the "generate-core-file" has been added.
5924 * New commands "dump", "append", and "restore".
5926 These commands allow data to be copied from target memory
5927 to a bfd-format or binary file (dump and append), and back
5928 from a file into memory (restore).
5930 * Improved "next/step" support on multi-processor Alpha Tru64.
5932 The previous single-step mechanism could cause unpredictable problems,
5933 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5934 of a software single-step mechanism prevents this.
5936 *** Changes in GDB 5.2.1:
5944 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5945 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5946 Fix, by Joel Brobecker imported from mainline.
5948 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5949 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5950 Fix, by Fred Fish, imported from mainline.
5952 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5953 Surprisingly enough, it works now.
5954 By Michal Ludvig, imported from mainline.
5956 i386 hardware watchpoint support:
5957 avoid misses on second run for some targets.
5958 By Pierre Muller, imported from mainline.
5960 *** Changes in GDB 5.2:
5962 * New command "set trust-readonly-sections on[off]".
5964 This command is a hint that tells gdb that read-only sections
5965 really are read-only (ie. that their contents will not change).
5966 In this mode, gdb will go to the object file rather than the
5967 target to read memory from read-only sections (such as ".text").
5968 This can be a significant performance improvement on some
5969 (notably embedded) targets.
5971 * New command "generate-core-file" (or "gcore").
5973 This new gdb command allows the user to drop a core file of the child
5974 process state at any time. So far it's been implemented only for
5975 GNU/Linux and Solaris, but should be relatively easily ported to other
5976 hosts. Argument is core file name (defaults to core.<pid>).
5978 * New command line option
5980 GDB now accepts --pid or -p followed by a process id.
5982 * Change in command line behavior -- corefiles vs. process ids.
5984 There is a subtle behavior in the way in which GDB handles
5985 command line arguments. The first non-flag argument is always
5986 a program to debug, but the second non-flag argument may either
5987 be a corefile or a process id. Previously, GDB would attempt to
5988 open the second argument as a corefile, and if that failed, would
5989 issue a superfluous error message and then attempt to attach it as
5990 a process. Now, if the second argument begins with a non-digit,
5991 it will be treated as a corefile. If it begins with a digit,
5992 GDB will attempt to attach it as a process, and if no such process
5993 is found, will then attempt to open it as a corefile.
5995 * Changes in ARM configurations.
5997 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5998 configuration is fully multi-arch.
6000 * New native configurations
6002 ARM NetBSD arm*-*-netbsd*
6003 x86 OpenBSD i[3456]86-*-openbsd*
6004 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6005 Sparc64 running FreeBSD sparc64-*-freebsd*
6009 Sanyo XStormy16 xstormy16-elf
6011 * OBSOLETE configurations and files
6013 Configurations that have been declared obsolete in this release have
6014 been commented out. Unless there is activity to revive these
6015 configurations, the next release of GDB will have their sources
6016 permanently REMOVED.
6018 AMD 29k family via UDI a29k-amd-udi, udi29k
6019 A29K VxWorks a29k-*-vxworks
6020 AMD 29000 embedded, using EBMON a29k-none-none
6021 AMD 29000 embedded with COFF a29k-none-coff
6022 AMD 29000 embedded with a.out a29k-none-aout
6024 testsuite/gdb.hp/gdb.threads-hp/ directory
6026 * REMOVED configurations and files
6028 TI TMS320C80 tic80-*-*
6030 PowerPC Solaris powerpcle-*-solaris*
6031 PowerPC Windows NT powerpcle-*-cygwin32
6032 PowerPC Netware powerpc-*-netware*
6033 Harris/CXUX m88k m88*-harris-cxux*
6034 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6035 ns32k-utek-sysv* ns32k-utek-*
6036 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6037 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6038 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6039 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6040 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6042 * Changes to command line processing
6044 The new `--args' feature can be used to specify command-line arguments
6045 for the inferior from gdb's command line.
6047 * Changes to key bindings
6049 There is a new `operate-and-get-next' function bound to `C-o'.
6051 *** Changes in GDB 5.1.1
6053 Fix compile problem on DJGPP.
6055 Fix a problem with floating-point registers on the i386 being
6058 Fix to stop GDB crashing on .debug_str debug info.
6060 Numerous documentation fixes.
6062 Numerous testsuite fixes.
6064 *** Changes in GDB 5.1:
6066 * New native configurations
6068 Alpha FreeBSD alpha*-*-freebsd*
6069 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6070 MIPS GNU/Linux mips*-*-linux*
6071 MIPS SGI Irix 6.x mips*-sgi-irix6*
6072 ia64 AIX ia64-*-aix*
6073 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6077 Motorola 68HC11 and 68HC12 m68hc11-elf
6079 UltraSparc running GNU/Linux sparc64-*-linux*
6081 * OBSOLETE configurations and files
6083 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6084 Harris/CXUX m88k m88*-harris-cxux*
6085 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6086 ns32k-utek-sysv* ns32k-utek-*
6087 TI TMS320C80 tic80-*-*
6089 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6090 PowerPC Solaris powerpcle-*-solaris*
6091 PowerPC Windows NT powerpcle-*-cygwin32
6092 PowerPC Netware powerpc-*-netware*
6093 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6094 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6095 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6096 Apple Macintosh (MPW) host N/A
6098 stuff.c (Program to stuff files into a specially prepared space in kdb)
6099 kdb-start.c (Main loop for the standalone kernel debugger)
6101 Configurations that have been declared obsolete in this release have
6102 been commented out. Unless there is activity to revive these
6103 configurations, the next release of GDB will have their sources
6104 permanently REMOVED.
6106 * REMOVED configurations and files
6108 Altos 3068 m68*-altos-*
6109 Convex c1-*-*, c2-*-*
6111 ARM RISCix arm-*-* (as host)
6115 * GDB has been converted to ISO C.
6117 GDB's source code has been converted to ISO C. In particular, the
6118 sources are fully protoized, and rely on standard headers being
6123 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6125 * The MI enabled by default.
6127 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6128 revised and enabled by default. Packages which use GDB as a debugging
6129 engine behind a UI or another front end are encouraged to switch to
6130 using the GDB/MI interface, instead of the old annotations interface
6131 which is now deprecated.
6133 * Support for debugging Pascal programs.
6135 GDB now includes support for debugging Pascal programs. The following
6136 main features are supported:
6138 - Pascal-specific data types such as sets;
6140 - automatic recognition of Pascal sources based on file-name
6143 - Pascal-style display of data types, variables, and functions;
6145 - a Pascal expression parser.
6147 However, some important features are not yet supported.
6149 - Pascal string operations are not supported at all;
6151 - there are some problems with boolean types;
6153 - Pascal type hexadecimal constants are not supported
6154 because they conflict with the internal variables format;
6156 - support for Pascal objects and classes is not full yet;
6158 - unlike Pascal, GDB is case-sensitive for symbol names.
6160 * Changes in completion.
6162 Commands such as `shell', `run' and `set args', which pass arguments
6163 to inferior programs, now complete on file names, similar to what
6164 users expect at the shell prompt.
6166 Commands which accept locations, such as `disassemble', `print',
6167 `breakpoint', `until', etc. now complete on filenames as well as
6168 program symbols. Thus, if you type "break foob TAB", and the source
6169 files linked into the programs include `foobar.c', that file name will
6170 be one of the candidates for completion. However, file names are not
6171 considered for completion after you typed a colon that delimits a file
6172 name from a name of a function in that file, as in "break foo.c:bar".
6174 `set demangle-style' completes on available demangling styles.
6176 * New platform-independent commands:
6178 It is now possible to define a post-hook for a command as well as a
6179 hook that runs before the command. For more details, see the
6180 documentation of `hookpost' in the GDB manual.
6182 * Changes in GNU/Linux native debugging.
6184 Support for debugging multi-threaded programs has been completely
6185 revised for all platforms except m68k and sparc. You can now debug as
6186 many threads as your system allows you to have.
6188 Attach/detach is supported for multi-threaded programs.
6190 Support for SSE registers was added for x86. This doesn't work for
6191 multi-threaded programs though.
6193 * Changes in MIPS configurations.
6195 Multi-arch support is enabled for all MIPS configurations.
6197 GDB can now be built as native debugger on SGI Irix 6.x systems for
6198 debugging n32 executables. (Debugging 64-bit executables is not yet
6201 * Unified support for hardware watchpoints in all x86 configurations.
6203 Most (if not all) native x86 configurations support hardware-assisted
6204 breakpoints and watchpoints in a unified manner. This support
6205 implements debug register sharing between watchpoints, which allows to
6206 put a virtually infinite number of watchpoints on the same address,
6207 and also supports watching regions up to 16 bytes with several debug
6210 The new maintenance command `maintenance show-debug-regs' toggles
6211 debugging print-outs in functions that insert, remove, and test
6212 watchpoints and hardware breakpoints.
6214 * Changes in the DJGPP native configuration.
6216 New command ``info dos sysinfo'' displays assorted information about
6217 the CPU, OS, memory, and DPMI server.
6219 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6220 display information about segment descriptors stored in GDT, LDT, and
6223 New commands ``info dos pde'' and ``info dos pte'' display entries
6224 from Page Directory and Page Tables (for now works with CWSDPMI only).
6225 New command ``info dos address-pte'' displays the Page Table entry for
6226 a given linear address.
6228 GDB can now pass command lines longer than 126 characters to the
6229 program being debugged (requires an update to the libdbg.a library
6230 which is part of the DJGPP development kit).
6232 DWARF2 debug info is now supported.
6234 It is now possible to `step' and `next' through calls to `longjmp'.
6236 * Changes in documentation.
6238 All GDB documentation was converted to GFDL, the GNU Free
6239 Documentation License.
6241 Tracepoints-related commands are now fully documented in the GDB
6244 TUI, the Text-mode User Interface, is now documented in the manual.
6246 Tracepoints-related commands are now fully documented in the GDB
6249 The "GDB Internals" manual now has an index. It also includes
6250 documentation of `ui_out' functions, GDB coding standards, x86
6251 hardware watchpoints, and memory region attributes.
6253 * GDB's version number moved to ``version.in''
6255 The Makefile variable VERSION has been replaced by the file
6256 ``version.in''. People creating GDB distributions should update the
6257 contents of this file.
6261 GUD support is now a standard part of the EMACS distribution.
6263 *** Changes in GDB 5.0:
6265 * Improved support for debugging FP programs on x86 targets
6267 Unified and much-improved support for debugging floating-point
6268 programs on all x86 targets. In particular, ``info float'' now
6269 displays the FP registers in the same format on all x86 targets, with
6270 greater level of detail.
6272 * Improvements and bugfixes in hardware-assisted watchpoints
6274 It is now possible to watch array elements, struct members, and
6275 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6276 on x86 targets no longer erroneously trigger when the address is
6279 * Improvements in the native DJGPP version of GDB
6281 The distribution now includes all the scripts and auxiliary files
6282 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6283 machines ``out of the box''.
6285 The DJGPP version can now debug programs that use signals. It is
6286 possible to catch signals that happened in the debuggee, deliver
6287 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6288 would kill the program being debugged.) Programs that hook hardware
6289 interrupts (keyboard, timer, etc.) can also be debugged.
6291 It is now possible to debug DJGPP programs that redirect their
6292 standard handles or switch them to raw (as opposed to cooked) mode, or
6293 even close them. The command ``run < foo > bar'' works as expected,
6294 and ``info terminal'' reports useful information about the debuggee's
6295 terminal, including raw/cooked mode, redirection, etc.
6297 The DJGPP version now uses termios functions for console I/O, which
6298 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6301 DOS-style file names with drive letters are now fully supported by
6304 It is now possible to debug DJGPP programs that switch their working
6305 directory. It is also possible to rerun the debuggee any number of
6306 times without restarting GDB; thus, you can use the same setup,
6307 breakpoints, etc. for many debugging sessions.
6309 * New native configurations
6311 ARM GNU/Linux arm*-*-linux*
6312 PowerPC GNU/Linux powerpc-*-linux*
6316 Motorola MCore mcore-*-*
6317 x86 VxWorks i[3456]86-*-vxworks*
6318 PowerPC VxWorks powerpc-*-vxworks*
6319 TI TMS320C80 tic80-*-*
6321 * OBSOLETE configurations
6323 Altos 3068 m68*-altos-*
6324 Convex c1-*-*, c2-*-*
6326 ARM RISCix arm-*-* (as host)
6329 Configurations that have been declared obsolete will be commented out,
6330 but the code will be left in place. If there is no activity to revive
6331 these configurations before the next release of GDB, the sources will
6332 be permanently REMOVED.
6334 * Gould support removed
6336 Support for the Gould PowerNode and NP1 has been removed.
6338 * New features for SVR4
6340 On SVR4 native platforms (such as Solaris), if you attach to a process
6341 without first loading a symbol file, GDB will now attempt to locate and
6342 load symbols from the running process's executable file.
6344 * Many C++ enhancements
6346 C++ support has been greatly improved. Overload resolution now works properly
6347 in almost all cases. RTTI support is on the way.
6349 * Remote targets can connect to a sub-program
6351 A popen(3) style serial-device has been added. This device starts a
6352 sub-process (such as a stand-alone simulator) and then communicates
6353 with that. The sub-program to run is specified using the syntax
6354 ``|<program> <args>'' vis:
6356 (gdb) set remotedebug 1
6357 (gdb) target extended-remote |mn10300-elf-sim program-args
6359 * MIPS 64 remote protocol
6361 A long standing bug in the mips64 remote protocol where by GDB
6362 expected certain 32 bit registers (ex SR) to be transfered as 32
6363 instead of 64 bits has been fixed.
6365 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6366 added to provide backward compatibility with older versions of GDB.
6368 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6370 The command ``set remotebinarydownload'' command has been replaced by
6371 ``set remote X-packet''. Other commands in ``set remote'' family
6372 include ``set remote P-packet''.
6374 * Breakpoint commands accept ranges.
6376 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6377 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6378 ``tracepoint passcount'' also accepts a range of tracepoints.
6380 * ``apropos'' command added.
6382 The ``apropos'' command searches through command names and
6383 documentation strings, printing out matches, making it much easier to
6384 try to find a command that does what you are looking for.
6388 A new machine oriented interface (MI) has been added to GDB. This
6389 interface is designed for debug environments running GDB as a separate
6390 process. This is part of the long term libGDB project. See the
6391 "GDB/MI" chapter of the GDB manual for further information. It can be
6392 enabled by configuring with:
6394 .../configure --enable-gdbmi
6396 *** Changes in GDB-4.18:
6398 * New native configurations
6400 HP-UX 10.20 hppa*-*-hpux10.20
6401 HP-UX 11.x hppa*-*-hpux11.0*
6402 M68K GNU/Linux m68*-*-linux*
6406 Fujitsu FR30 fr30-*-elf*
6407 Intel StrongARM strongarm-*-*
6408 Mitsubishi D30V d30v-*-*
6410 * OBSOLETE configurations
6412 Gould PowerNode, NP1 np1-*-*, pn-*-*
6414 Configurations that have been declared obsolete will be commented out,
6415 but the code will be left in place. If there is no activity to revive
6416 these configurations before the next release of GDB, the sources will
6417 be permanently REMOVED.
6421 As a compatibility experiment, GDB's source files buildsym.h and
6422 buildsym.c have been converted to pure standard C, no longer
6423 containing any K&R compatibility code. We believe that all systems in
6424 use today either come with a standard C compiler, or have a GCC port
6425 available. If this is not true, please report the affected
6426 configuration to bug-gdb@gnu.org immediately. See the README file for
6427 information about getting a standard C compiler if you don't have one
6432 GDB now uses readline 2.2.
6434 * set extension-language
6436 You can now control the mapping between filename extensions and source
6437 languages by using the `set extension-language' command. For instance,
6438 you can ask GDB to treat .c files as C++ by saying
6439 set extension-language .c c++
6440 The command `info extensions' lists all of the recognized extensions
6441 and their associated languages.
6443 * Setting processor type for PowerPC and RS/6000
6445 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6446 you can use the `set processor' command to specify what variant of the
6447 PowerPC family you are debugging. The command
6451 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6452 following PowerPC and RS6000 variants:
6454 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6455 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6457 403GC IBM PowerPC 403GC
6458 505 Motorola PowerPC 505
6459 860 Motorola PowerPC 860 or 850
6460 601 Motorola PowerPC 601
6461 602 Motorola PowerPC 602
6462 603 Motorola/IBM PowerPC 603 or 603e
6463 604 Motorola PowerPC 604 or 604e
6464 750 Motorola/IBM PowerPC 750 or 750
6466 At the moment, this command just tells GDB what to name the
6467 special-purpose processor registers. Since almost all the affected
6468 registers are inaccessible to user-level programs, this command is
6469 only useful for remote debugging in its present form.
6473 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6474 more extensive support for HP-UX. Added features include shared
6475 library support, kernel threads and hardware watchpoints for 11.00,
6476 support for HP's ANSI C and C++ compilers, and a compatibility mode
6477 for xdb and dbx commands.
6481 HP's donation includes the new concept of catchpoints, which is a
6482 generalization of the old catch command. On HP-UX, it is now possible
6483 to catch exec, fork, and vfork, as well as library loading.
6485 This means that the existing catch command has changed; its first
6486 argument now specifies the type of catch to be set up. See the
6487 output of "help catch" for a list of catchpoint types.
6489 * Debugging across forks
6491 On HP-UX, you can choose which process to debug when a fork() happens
6496 HP has donated a curses-based terminal user interface (TUI). To get
6497 it, build with --enable-tui. Although this can be enabled for any
6498 configuration, at present it only works for native HP debugging.
6500 * GDB remote protocol additions
6502 A new protocol packet 'X' that writes binary data is now available.
6503 Default behavior is to try 'X', then drop back to 'M' if the stub
6504 fails to respond. The settable variable `remotebinarydownload'
6505 allows explicit control over the use of 'X'.
6507 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6508 full 64-bit address. The command
6510 set remoteaddresssize 32
6512 can be used to revert to the old behaviour. For existing remote stubs
6513 the change should not be noticed, as the additional address information
6516 In order to assist in debugging stubs, you may use the maintenance
6517 command `packet' to send any text string to the stub. For instance,
6519 maint packet heythere
6521 sends the packet "$heythere#<checksum>". Note that it is very easy to
6522 disrupt a debugging session by sending the wrong packet at the wrong
6525 The compare-sections command allows you to compare section data on the
6526 target to what is in the executable file without uploading or
6527 downloading, by comparing CRC checksums.
6529 * Tracing can collect general expressions
6531 You may now collect general expressions at tracepoints. This requires
6532 further additions to the target-side stub; see tracepoint.c and
6533 doc/agentexpr.texi for further details.
6535 * mask-address variable for Mips
6537 For Mips targets, you may control the zeroing of the upper 32 bits of
6538 a 64-bit address by entering `set mask-address on'. This is mainly
6539 of interest to users of embedded R4xxx and R5xxx processors.
6541 * Higher serial baud rates
6543 GDB's serial code now allows you to specify baud rates 57600, 115200,
6544 230400, and 460800 baud. (Note that your host system may not be able
6545 to achieve all of these rates.)
6549 The i960 configuration now includes an initial implementation of a
6550 builtin simulator, contributed by Jim Wilson.
6553 *** Changes in GDB-4.17:
6555 * New native configurations
6557 Alpha GNU/Linux alpha*-*-linux*
6558 Unixware 2.x i[3456]86-unixware2*
6559 Irix 6.x mips*-sgi-irix6*
6560 PowerPC GNU/Linux powerpc-*-linux*
6561 PowerPC Solaris powerpcle-*-solaris*
6562 Sparc GNU/Linux sparc-*-linux*
6563 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6567 Argonaut Risc Chip (ARC) arc-*-*
6568 Hitachi H8/300S h8300*-*-*
6569 Matsushita MN10200 w/simulator mn10200-*-*
6570 Matsushita MN10300 w/simulator mn10300-*-*
6571 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6572 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6573 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6574 Mitsubishi D10V w/simulator d10v-*-*
6575 Mitsubishi M32R/D w/simulator m32r-*-elf*
6576 Tsqware Sparclet sparclet-*-*
6577 NEC V850 w/simulator v850-*-*
6579 * New debugging protocols
6581 ARM with RDI protocol arm*-*-*
6582 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6583 DDB and LSI variants of PMON protocol mips*-*-*
6584 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6585 PowerPC with SDS protocol powerpc{,le}-*-eabi
6586 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6590 All configurations can now understand and use the DWARF 2 debugging
6591 format. The choice is automatic, if the symbol file contains DWARF 2
6596 GDB now includes basic Java language support. This support is
6597 only useful with Java compilers that produce native machine code.
6599 * solib-absolute-prefix and solib-search-path
6601 For SunOS and SVR4 shared libraries, you may now set the prefix for
6602 loading absolute shared library symbol files, and the search path for
6603 locating non-absolute shared library symbol files.
6605 * Live range splitting
6607 GDB can now effectively debug code for which GCC has performed live
6608 range splitting as part of its optimization. See gdb/doc/LRS for
6609 more details on the expected format of the stabs information.
6613 GDB's support for the GNU Hurd, including thread debugging, has been
6614 updated to work with current versions of the Hurd.
6618 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6619 instruction set. ARM GDB automatically detects when Thumb
6620 instructions are in use, and adjusts disassembly and backtracing
6625 GDB's MIPS target configurations now handle the MIP16 16-bit
6630 GDB now includes support for overlays; if an executable has been
6631 linked such that multiple sections are based at the same address, GDB
6632 will decide which section to use for symbolic info. You can choose to
6633 control the decision manually, using overlay commands, or implement
6634 additional target-side support and use "overlay load-target" to bring
6635 in the overlay mapping. Do "help overlay" for more detail.
6639 The command "info symbol <address>" displays information about
6640 the symbol at the specified address.
6644 The standard remote protocol now includes an extension that allows
6645 asynchronous collection and display of trace data. This requires
6646 extensive support in the target-side debugging stub. Tracing mode
6647 includes a new interaction mode in GDB and new commands: see the
6648 file tracepoint.c for more details.
6652 Configurations for embedded MIPS now include a simulator contributed
6653 by Cygnus Solutions. The simulator supports the instruction sets
6654 of most MIPS variants.
6658 Sparc configurations may now include the ERC32 simulator contributed
6659 by the European Space Agency. The simulator is not built into
6660 Sparc targets by default; configure with --enable-sim to include it.
6664 For target configurations that may include multiple variants of a
6665 basic architecture (such as MIPS and SH), you may now set the
6666 architecture explicitly. "set arch" sets, "info arch" lists
6667 the possible architectures.
6669 *** Changes in GDB-4.16:
6671 * New native configurations
6673 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6674 M68K NetBSD m68k-*-netbsd*
6675 PowerPC AIX 4.x powerpc-*-aix*
6676 PowerPC MacOS powerpc-*-macos*
6677 PowerPC Windows NT powerpcle-*-cygwin32
6678 RS/6000 AIX 4.x rs6000-*-aix4*
6682 ARM with RDP protocol arm-*-*
6683 I960 with MON960 i960-*-coff
6684 MIPS VxWorks mips*-*-vxworks*
6685 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6686 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6688 Matra Sparclet sparclet-*-*
6692 The powerpc-eabi configuration now includes the PSIM simulator,
6693 contributed by Andrew Cagney, with assistance from Mike Meissner.
6694 PSIM is a very elaborate model of the PowerPC, including not only
6695 basic instruction set execution, but also details of execution unit
6696 performance and I/O hardware. See sim/ppc/README for more details.
6700 GDB now works with Solaris 2.5.
6702 * Windows 95/NT native
6704 GDB will now work as a native debugger on Windows 95 and Windows NT.
6705 To build it from source, you must use the "gnu-win32" environment,
6706 which uses a DLL to emulate enough of Unix to run the GNU tools.
6707 Further information, binaries, and sources are available at
6708 ftp.cygnus.com, under pub/gnu-win32.
6710 * dont-repeat command
6712 If a user-defined command includes the command `dont-repeat', then the
6713 command will not be repeated if the user just types return. This is
6714 useful if the command is time-consuming to run, so that accidental
6715 extra keystrokes don't run the same command many times.
6717 * Send break instead of ^C
6719 The standard remote protocol now includes an option to send a break
6720 rather than a ^C to the target in order to interrupt it. By default,
6721 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6723 * Remote protocol timeout
6725 The standard remote protocol includes a new variable `remotetimeout'
6726 that allows you to set the number of seconds before GDB gives up trying
6727 to read from the target. The default value is 2.
6729 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6731 By default GDB will automatically keep track of objects as they are
6732 loaded and unloaded by the dynamic linker. By using the command `set
6733 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6734 when shared library events occur, thus allowing you to set breakpoints
6735 in shared libraries which are explicitly loaded by the inferior.
6737 Note this feature does not work on hpux8. On hpux9 you must link
6738 /usr/lib/end.o into your program. This feature should work
6739 automatically on hpux10.
6741 * Irix 5.x hardware watchpoint support
6743 Irix 5 configurations now support the use of hardware watchpoints.
6745 * Mips protocol "SYN garbage limit"
6747 When debugging a Mips target using the `target mips' protocol, you
6748 may set the number of characters that GDB will ignore by setting
6749 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6750 every character. The default value is 1050.
6752 * Recording and replaying remote debug sessions
6754 If you set `remotelogfile' to the name of a file, gdb will write to it
6755 a recording of a remote debug session. This recording may then be
6756 replayed back to gdb using "gdbreplay". See gdbserver/README for
6757 details. This is useful when you have a problem with GDB while doing
6758 remote debugging; you can make a recording of the session and send it
6759 to someone else, who can then recreate the problem.
6761 * Speedups for remote debugging
6763 GDB includes speedups for downloading and stepping MIPS systems using
6764 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6765 and more efficient S-record downloading.
6767 * Memory use reductions and statistics collection
6769 GDB now uses less memory and reports statistics about memory usage.
6770 Try the `maint print statistics' command, for example.
6772 *** Changes in GDB-4.15:
6774 * Psymtabs for XCOFF
6776 The symbol reader for AIX GDB now uses partial symbol tables. This
6777 can greatly improve startup time, especially for large executables.
6779 * Remote targets use caching
6781 Remote targets now use a data cache to speed up communication with the
6782 remote side. The data cache could lead to incorrect results because
6783 it doesn't know about volatile variables, thus making it impossible to
6784 debug targets which use memory mapped I/O devices. `set remotecache
6785 off' turns the data cache off.
6787 * Remote targets may have threads
6789 The standard remote protocol now includes support for multiple threads
6790 in the target system, using new protocol commands 'H' and 'T'. See
6791 gdb/remote.c for details.
6795 If GDB is configured with `--enable-netrom', then it will include
6796 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6797 acts as though it is a bank of ROM on the target board, but you can
6798 write into it over the network. GDB's support consists only of
6799 support for fast loading into the emulated ROM; to debug, you must use
6800 another protocol, such as standard remote protocol. The usual
6801 sequence is something like
6803 target nrom <netrom-hostname>
6805 target remote <netrom-hostname>:1235
6809 GDB now includes support for the Apple Macintosh, as a host only. It
6810 may be run as either an MPW tool or as a standalone application, and
6811 it can debug through the serial port. All the usual GDB commands are
6812 available, but to the target command, you must supply "serial" as the
6813 device type instead of "/dev/ttyXX". See mpw-README in the main
6814 directory for more information on how to build. The MPW configuration
6815 scripts */mpw-config.in support only a few targets, and only the
6816 mips-idt-ecoff target has been tested.
6820 GDB configuration now uses autoconf. This is not user-visible,
6821 but does simplify configuration and building.
6825 GDB now supports hpux10.
6827 *** Changes in GDB-4.14:
6829 * New native configurations
6831 x86 FreeBSD i[345]86-*-freebsd
6832 x86 NetBSD i[345]86-*-netbsd
6833 NS32k NetBSD ns32k-*-netbsd
6834 Sparc NetBSD sparc-*-netbsd
6838 A29K VxWorks a29k-*-vxworks
6839 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6840 CPU32 EST-300 emulator m68*-*-est*
6841 PowerPC ELF powerpc-*-elf
6844 * Alpha OSF/1 support for procfs
6846 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6847 possible to attach to running processes. As the mounting of the /proc
6848 filesystem is optional on the Alpha, GDB automatically determines
6849 the availability of /proc during startup. This can lead to problems
6850 if /proc is unmounted after GDB has been started.
6852 * Arguments to user-defined commands
6854 User commands may accept up to 10 arguments separated by whitespace.
6855 Arguments are accessed within the user command via $arg0..$arg9. A
6858 print $arg0 + $arg1 + $arg2
6860 To execute the command use:
6863 Defines the command "adder" which prints the sum of its three arguments.
6864 Note the arguments are text substitutions, so they may reference variables,
6865 use complex expressions, or even perform inferior function calls.
6867 * New `if' and `while' commands
6869 This makes it possible to write more sophisticated user-defined
6870 commands. Both commands take a single argument, which is the
6871 expression to evaluate, and must be followed by the commands to
6872 execute, one per line, if the expression is nonzero, the list being
6873 terminated by the word `end'. The `if' command list may include an
6874 `else' word, which causes the following commands to be executed only
6875 if the expression is zero.
6877 * Fortran source language mode
6879 GDB now includes partial support for Fortran 77. It will recognize
6880 Fortran programs and can evaluate a subset of Fortran expressions, but
6881 variables and functions may not be handled correctly. GDB will work
6882 with G77, but does not yet know much about symbols emitted by other
6885 * Better HPUX support
6887 Most debugging facilities now work on dynamic executables for HPPAs
6888 running hpux9 or later. You can attach to running dynamically linked
6889 processes, but by default the dynamic libraries will be read-only, so
6890 for instance you won't be able to put breakpoints in them. To change
6891 that behavior do the following before running the program:
6897 This will cause the libraries to be mapped private and read-write.
6898 To revert to the normal behavior, do this:
6904 You cannot set breakpoints or examine data in the library until after
6905 the library is loaded if the function/data symbols do not have
6908 GDB can now also read debug symbols produced by the HP C compiler on
6909 HPPAs (sorry, no C++, Fortran or 68k support).
6911 * Target byte order now dynamically selectable
6913 You can choose which byte order to use with a target system, via the
6914 commands "set endian big" and "set endian little", and you can see the
6915 current setting by using "show endian". You can also give the command
6916 "set endian auto", in which case GDB will use the byte order
6917 associated with the executable. Currently, only embedded MIPS
6918 configurations support dynamic selection of target byte order.
6920 * New DOS host serial code
6922 This version uses DPMI interrupts to handle buffered I/O, so you
6923 no longer need to run asynctsr when debugging boards connected to
6926 *** Changes in GDB-4.13:
6928 * New "complete" command
6930 This lists all the possible completions for the rest of the line, if it
6931 were to be given as a command itself. This is intended for use by emacs.
6933 * Trailing space optional in prompt
6935 "set prompt" no longer adds a space for you after the prompt you set. This
6936 allows you to set a prompt which ends in a space or one that does not.
6938 * Breakpoint hit counts
6940 "info break" now displays a count of the number of times the breakpoint
6941 has been hit. This is especially useful in conjunction with "ignore"; you
6942 can ignore a large number of breakpoint hits, look at the breakpoint info
6943 to see how many times the breakpoint was hit, then run again, ignoring one
6944 less than that number, and this will get you quickly to the last hit of
6947 * Ability to stop printing at NULL character
6949 "set print null-stop" will cause GDB to stop printing the characters of
6950 an array when the first NULL is encountered. This is useful when large
6951 arrays actually contain only short strings.
6953 * Shared library breakpoints
6955 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6956 breakpoints in shared libraries before the executable is run.
6958 * Hardware watchpoints
6960 There is a new hardware breakpoint for the watch command for sparclite
6961 targets. See gdb/sparclite/hw_breakpoint.note.
6963 Hardware watchpoints are also now supported under GNU/Linux.
6967 Annotations have been added. These are for use with graphical interfaces,
6968 and are still experimental. Currently only gdba.el uses these.
6970 * Improved Irix 5 support
6972 GDB now works properly with Irix 5.2.
6974 * Improved HPPA support
6976 GDB now works properly with the latest GCC and GAS.
6978 * New native configurations
6980 Sequent PTX4 i[34]86-sequent-ptx4
6981 HPPA running OSF/1 hppa*-*-osf*
6982 Atari TT running SVR4 m68*-*-sysv4*
6983 RS/6000 LynxOS rs6000-*-lynxos*
6987 OS/9000 i[34]86-*-os9k
6988 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6991 * Hitachi SH7000 and E7000-PC ICE support
6993 There is now support for communicating with the Hitachi E7000-PC ICE.
6994 This is available automatically when GDB is configured for the SH.
6998 As usual, a variety of small fixes and improvements, both generic
6999 and configuration-specific. See the ChangeLog for more detail.
7001 *** Changes in GDB-4.12:
7003 * Irix 5 is now supported
7007 GDB-4.12 on the HPPA has a number of changes which make it unable
7008 to debug the output from the currently released versions of GCC and
7009 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7010 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7011 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7014 *** Changes in GDB-4.11:
7016 * User visible changes:
7020 The "set remotedebug" option is now consistent between the mips remote
7021 target, remote targets using the gdb-specific protocol, UDI (AMD's
7022 debug protocol for the 29k) and the 88k bug monitor. It is now an
7023 integer specifying a debug level (normally 0 or 1, but 2 means more
7024 debugging info for the mips target).
7026 * DEC Alpha native support
7028 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7029 debug info, but GDB works fairly well with the DEC compiler and should
7030 work with a future GCC release. See the README file for a few
7031 Alpha-specific notes.
7033 * Preliminary thread implementation
7035 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7037 * LynxOS native and target support for 386
7039 This release has been hosted on LynxOS 2.2, and also can be configured
7040 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7043 * Improvements in C++ mangling/demangling.
7045 This release has much better g++ debugging, specifically in name
7046 mangling/demangling, virtual function calls, print virtual table,
7047 call methods, ...etc.
7049 *** Changes in GDB-4.10:
7051 * User visible changes:
7053 Remote debugging using the GDB-specific (`target remote') protocol now
7054 supports the `load' command. This is only useful if you have some
7055 other way of getting the stub to the target system, and you can put it
7056 somewhere in memory where it won't get clobbered by the download.
7058 Filename completion now works.
7060 When run under emacs mode, the "info line" command now causes the
7061 arrow to point to the line specified. Also, "info line" prints
7062 addresses in symbolic form (as well as hex).
7064 All vxworks based targets now support a user settable option, called
7065 vxworks-timeout. This option represents the number of seconds gdb
7066 should wait for responses to rpc's. You might want to use this if
7067 your vxworks target is, perhaps, a slow software simulator or happens
7068 to be on the far side of a thin network line.
7072 This release contains support for using a DEC alpha as a GDB host for
7073 cross debugging. Native alpha debugging is not supported yet.
7076 *** Changes in GDB-4.9:
7080 This is the first GDB release which is accompanied by a matching testsuite.
7081 The testsuite requires installation of dejagnu, which should be available
7082 via ftp from most sites that carry GNU software.
7086 'Cfront' style demangling has had its name changed to 'ARM' style, to
7087 emphasize that it was written from the specifications in the C++ Annotated
7088 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7089 disclaimers, it still generated too much confusion with users attempting to
7090 use gdb with AT&T cfront.
7094 GDB now uses a standard remote interface to a simulator library.
7095 So far, the library contains simulators for the Zilog Z8001/2, the
7096 Hitachi H8/300, H8/500 and Super-H.
7098 * New targets supported
7100 H8/300 simulator h8300-hitachi-hms or h8300hms
7101 H8/500 simulator h8500-hitachi-hms or h8500hms
7102 SH simulator sh-hitachi-hms or sh
7103 Z8000 simulator z8k-zilog-none or z8ksim
7104 IDT MIPS board over serial line mips-idt-ecoff
7106 Cross-debugging to GO32 targets is supported. It requires a custom
7107 version of the i386-stub.c module which is integrated with the
7108 GO32 memory extender.
7110 * New remote protocols
7112 MIPS remote debugging protocol.
7114 * New source languages supported
7116 This version includes preliminary support for Chill, a Pascal like language
7117 used by telecommunications companies. Chill support is also being integrated
7118 into the GNU compiler, but we don't know when it will be publically available.
7121 *** Changes in GDB-4.8:
7123 * HP Precision Architecture supported
7125 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7126 version of this support was available as a set of patches from the
7127 University of Utah. GDB does not support debugging of programs
7128 compiled with the HP compiler, because HP will not document their file
7129 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7130 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7132 Many problems in the preliminary version have been fixed.
7134 * Faster and better demangling
7136 We have improved template demangling and fixed numerous bugs in the GNU style
7137 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7138 character types (wchar_t) are now supported. Demangling of each symbol is now
7139 only done once, and is cached when the symbol table for a file is read in.
7140 This results in a small increase in memory usage for C programs, a moderate
7141 increase in memory usage for C++ programs, and a fantastic speedup in
7144 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7145 from the specifications in the Annotated Reference Manual, which AT&T's
7146 compiler does not actually implement.
7148 * G++ multiple inheritance compiler problem
7150 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7151 inheritance lattices was reworked to properly discover ambiguities. We
7152 recently found an example which causes this new algorithm to fail in a
7153 very subtle way, producing bad debug information for those classes.
7154 The file 'gcc.patch' (in this directory) can be applied to gcc to
7155 circumvent the problem. A future GCC release will contain a complete
7158 The previous G++ debug info problem (mentioned below for the gdb-4.7
7159 release) is fixed in gcc version 2.3.2.
7161 * Improved configure script
7163 The `configure' script will now attempt to guess your system type if
7164 you don't supply a host system type. The old scheme of supplying a
7165 host system triplet is preferable over using this. All the magic is
7166 done in the new `config.guess' script. Examine it for details.
7168 We have also brought our configure script much more in line with the FSF's
7169 version. It now supports the --with-xxx options. In particular,
7170 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7171 The resulting GDB will not be able to read arbitrary object file formats --
7172 only the format ``expected'' to be used on the configured target system.
7173 We hope to make this the default in a future release.
7175 * Documentation improvements
7177 There's new internal documentation on how to modify GDB, and how to
7178 produce clean changes to the code. We implore people to read it
7179 before submitting changes.
7181 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7182 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7183 `info' files are also provided. To build `info' files from scratch,
7184 you will need the latest `makeinfo' release, which will be available in
7185 a future texinfo-X.Y release.
7187 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7188 We're not sure exactly which versions have this problem, but it has
7189 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7190 or better. If that isn't possible, there is a patch in
7191 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7192 around this problem.
7196 GDB now supports array constants that can be used in expressions typed in by
7197 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7198 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7201 The new directory `gdb/sparclite' contains a program that demonstrates
7202 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7204 * New native hosts supported
7206 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7207 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7209 * New targets supported
7211 AMD 29k family via UDI a29k-amd-udi or udi29k
7213 * New file formats supported
7215 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7216 HPUX core files, and SCO 3.2v2 core files.
7220 Attaching to processes now works again; thanks for the many bug reports.
7222 We have also stomped on a bunch of core dumps caused by
7223 printf_filtered("%s") problems.
7225 We eliminated a copyright problem on the rpc and ptrace header files
7226 for VxWorks, which was discovered at the last minute during the 4.7
7227 release. You should now be able to build a VxWorks GDB.
7229 You can now interrupt gdb while an attached process is running. This
7230 will cause the attached process to stop, and give control back to GDB.
7232 We fixed problems caused by using too many file descriptors
7233 for reading symbols from object files and libraries. This was
7234 especially a problem for programs that used many (~100) shared
7237 The `step' command now only enters a subroutine if there is line number
7238 information for the subroutine. Otherwise it acts like the `next'
7239 command. Previously, `step' would enter subroutines if there was
7240 any debugging information about the routine. This avoids problems
7241 when using `cc -g1' on MIPS machines.
7243 * Internal improvements
7245 GDB's internal interfaces have been improved to make it easier to support
7246 debugging of multiple languages in the future.
7248 GDB now uses a common structure for symbol information internally.
7249 Minimal symbols (derived from linkage symbols in object files), partial
7250 symbols (from a quick scan of debug information), and full symbols
7251 contain a common subset of information, making it easier to write
7252 shared code that handles any of them.
7254 * New command line options
7256 We now accept --silent as an alias for --quiet.
7260 The memory-mapped-malloc library is now licensed under the GNU Library
7261 General Public License.
7263 *** Changes in GDB-4.7:
7265 * Host/native/target split
7267 GDB has had some major internal surgery to untangle the support for
7268 hosts and remote targets. Now, when you configure GDB for a remote
7269 target, it will no longer load in all of the support for debugging
7270 local programs on the host. When fully completed and tested, this will
7271 ensure that arbitrary host/target combinations are possible.
7273 The primary conceptual shift is to separate the non-portable code in
7274 GDB into three categories. Host specific code is required any time GDB
7275 is compiled on that host, regardless of the target. Target specific
7276 code relates to the peculiarities of the target, but can be compiled on
7277 any host. Native specific code is everything else: it can only be
7278 built when the host and target are the same system. Child process
7279 handling and core file support are two common `native' examples.
7281 GDB's use of /proc for controlling Unix child processes is now cleaner.
7282 It has been split out into a single module under the `target_ops' vector,
7283 plus two native-dependent functions for each system that uses /proc.
7285 * New hosts supported
7287 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7288 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7289 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7291 * New targets supported
7293 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7294 68030 and CPU32 m68030-*-*, m68332-*-*
7296 * New native hosts supported
7298 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7299 (386bsd is not well tested yet)
7300 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7302 * New file formats supported
7304 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7305 supports reading of `a.out.adobe' object files, which are an a.out
7306 format extended with minimal information about multiple sections.
7310 `show copying' is the same as the old `info copying'.
7311 `show warranty' is the same as `info warrantee'.
7312 These were renamed for consistency. The old commands continue to work.
7314 `info handle' is a new alias for `info signals'.
7316 You can now define pre-command hooks, which attach arbitrary command
7317 scripts to any command. The commands in the hook will be executed
7318 prior to the user's command. You can also create a hook which will be
7319 executed whenever the program stops. See gdb.texinfo.
7323 We now deal with Cfront style name mangling, and can even extract type
7324 info from mangled symbols. GDB can automatically figure out which
7325 symbol mangling style your C++ compiler uses.
7327 Calling of methods and virtual functions has been improved as well.
7331 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7332 fixed. This was due to mishandling of the extra N_SO stabs output
7335 We also finally got Ultrix 4.2 running in house, and fixed core file
7336 support, with help from a dozen people on the net.
7338 John M. Farrell discovered that the reason that single-stepping was so
7339 slow on all of the Mips based platforms (primarily SGI and DEC) was
7340 that we were trying to demangle and lookup a symbol used for internal
7341 purposes on every instruction that was being stepped through. Changing
7342 the name of that symbol so that it couldn't be mistaken for a C++
7343 mangled symbol sped things up a great deal.
7345 Rich Pixley sped up symbol lookups in general by getting much smarter
7346 about when C++ symbol mangling is necessary. This should make symbol
7347 completion (TAB on the command line) much faster. It's not as fast as
7348 we'd like, but it's significantly faster than gdb-4.6.
7352 A new user controllable variable 'call_scratch_address' can
7353 specify the location of a scratch area to be used when GDB
7354 calls a function in the target. This is necessary because the
7355 usual method of putting the scratch area on the stack does not work
7356 in systems that have separate instruction and data spaces.
7358 We integrated changes to support the 29k UDI (Universal Debugger
7359 Interface), but discovered at the last minute that we didn't have all
7360 of the appropriate copyright paperwork. We are working with AMD to
7361 resolve this, and hope to have it available soon.
7365 We have sped up the remote serial line protocol, especially for targets
7366 with lots of registers. It now supports a new `expedited status' ('T')
7367 message which can be used in place of the existing 'S' status message.
7368 This allows the remote stub to send only the registers that GDB
7369 needs to make a quick decision about single-stepping or conditional
7370 breakpoints, eliminating the need to fetch the entire register set for
7371 each instruction being stepped through.
7373 The GDB remote serial protocol now implements a write-through cache for
7374 registers, only re-reading the registers if the target has run.
7376 There is also a new remote serial stub for SPARC processors. You can
7377 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7378 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7379 processor with a serial port.
7383 Configure.in files have become much easier to read and modify. A new
7384 `table driven' format makes it more obvious what configurations are
7385 supported, and what files each one uses.
7389 There is a new opcodes library which will eventually contain all of the
7390 disassembly routines and opcode tables. At present, it only contains
7391 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7392 disassembler (binutils/objdump) to share these routines.
7394 The libiberty library is now copylefted under the GNU Library General
7395 Public License. This allows more liberal use, and was done so libg++
7396 can use it. This makes no difference to GDB, since the Library License
7397 grants all the rights from the General Public License.
7401 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7402 reference to the stabs symbol info used by the debugger. It is (as far
7403 as we know) the only published document on this fascinating topic. We
7404 encourage you to read it, compare it to the stabs information on your
7405 system, and send improvements on the document in general (to
7406 bug-gdb@prep.ai.mit.edu).
7408 And, of course, many bugs have been fixed.
7411 *** Changes in GDB-4.6:
7413 * Better support for C++ function names
7415 GDB now accepts as input the "demangled form" of C++ overloaded function
7416 names and member function names, and can do command completion on such names
7417 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7418 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7419 Make use of command completion, it is your friend.
7421 GDB also now accepts a variety of C++ mangled symbol formats. They are
7422 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7423 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7424 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7425 for the list of formats.
7427 * G++ symbol mangling problem
7429 Recent versions of gcc have a bug in how they emit debugging information for
7430 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7431 directory) can be applied to gcc to fix the problem. Alternatively, if you
7432 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7433 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7434 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7437 * New 'maintenance' command
7439 All of the commands related to hacking GDB internals have been moved out of
7440 the main command set, and now live behind the 'maintenance' command. This
7441 can also be abbreviated as 'mt'. The following changes were made:
7443 dump-me -> maintenance dump-me
7444 info all-breakpoints -> maintenance info breakpoints
7445 printmsyms -> maintenance print msyms
7446 printobjfiles -> maintenance print objfiles
7447 printpsyms -> maintenance print psymbols
7448 printsyms -> maintenance print symbols
7450 The following commands are new:
7452 maintenance demangle Call internal GDB demangler routine to
7453 demangle a C++ link name and prints the result.
7454 maintenance print type Print a type chain for a given symbol
7456 * Change to .gdbinit file processing
7458 We now read the $HOME/.gdbinit file before processing the argv arguments
7459 (e.g. reading symbol files or core files). This allows global parameters to
7460 be set, which will apply during the symbol reading. The ./.gdbinit is still
7461 read after argv processing.
7463 * New hosts supported
7465 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7467 GNU/Linux support i386-unknown-linux or linux
7469 We are also including code to support the HP/PA running BSD and HPUX. This
7470 is almost guaranteed not to work, as we didn't have time to test or build it
7471 for this release. We are including it so that the more adventurous (or
7472 masochistic) of you can play with it. We also had major problems with the
7473 fact that the compiler that we got from HP doesn't support the -g option.
7476 * New targets supported
7478 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7480 * More smarts about finding #include files
7482 GDB now remembers the compilation directory for all include files, and for
7483 all files from which C is generated (like yacc and lex sources). This
7484 greatly improves GDB's ability to find yacc/lex sources, and include files,
7485 especially if you are debugging your program from a directory different from
7486 the one that contains your sources.
7488 We also fixed a bug which caused difficulty with listing and setting
7489 breakpoints in include files which contain C code. (In the past, you had to
7490 try twice in order to list an include file that you hadn't looked at before.)
7492 * Interesting infernals change
7494 GDB now deals with arbitrary numbers of sections, where the symbols for each
7495 section must be relocated relative to that section's landing place in the
7496 target's address space. This work was needed to support ELF with embedded
7497 stabs used by Solaris-2.0.
7499 * Bug fixes (of course!)
7501 There have been loads of fixes for the following things:
7502 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7503 i960, stabs, DOS(GO32), procfs, etc...
7505 See the ChangeLog for details.
7507 *** Changes in GDB-4.5:
7509 * New machines supported (host and target)
7511 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7513 SGI Irix-4.x mips-sgi-irix4 or iris4
7515 * New malloc package
7517 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7518 Mmalloc is capable of handling multiple heaps of memory. It is also
7519 capable of saving a heap to a file, and then mapping it back in later.
7520 This can be used to greatly speedup the startup of GDB by using a
7521 pre-parsed symbol table which lives in a mmalloc managed heap. For
7522 more details, please read mmalloc/mmalloc.texi.
7526 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7527 'help info proc' for details.
7529 * MIPS ecoff symbol table format
7531 The code that reads MIPS symbol table format is now supported on all hosts.
7532 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7535 * File name changes for MS-DOS
7537 Many files in the config directories have been renamed to make it easier to
7538 support GDB on MS-DOSe systems (which have very restrictive file name
7539 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7540 environment) is close to working but has some remaining problems. Note
7541 that debugging of DOS programs is not supported, due to limitations
7542 in the ``operating system'', but it can be used to host cross-debugging.
7544 * Cross byte order fixes
7546 Many fixes have been made to support cross debugging of Sparc and MIPS
7547 targets from hosts whose byte order differs.
7549 * New -mapped and -readnow options
7551 If memory-mapped files are available on your system through the 'mmap'
7552 system call, you can use the -mapped option on the `file' or
7553 `symbol-file' commands to cause GDB to write the symbols from your
7554 program into a reusable file. If the program you are debugging is
7555 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7556 Future GDB debugging sessions will notice the presence of this file,
7557 and will quickly map in symbol information from it, rather than reading
7558 the symbol table from the executable program. Using the '-mapped'
7559 option in a GDB `file' or `symbol-file' command has the same effect as
7560 starting GDB with the '-mapped' command-line option.
7562 You can cause GDB to read the entire symbol table immediately by using
7563 the '-readnow' option with any of the commands that load symbol table
7564 information (or on the GDB command line). This makes the command
7565 slower, but makes future operations faster.
7567 The -mapped and -readnow options are typically combined in order to
7568 build a `fred.syms' file that contains complete symbol information.
7569 A simple GDB invocation to do nothing but build a `.syms' file for future
7572 gdb -batch -nx -mapped -readnow programname
7574 The `.syms' file is specific to the host machine on which GDB is run.
7575 It holds an exact image of GDB's internal symbol table. It cannot be
7576 shared across multiple host platforms.
7578 * longjmp() handling
7580 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7581 siglongjmp() without losing control. This feature has not yet been ported to
7582 all systems. It currently works on many 386 platforms, all MIPS-based
7583 platforms (SGI, DECstation, etc), and Sun3/4.
7587 Preliminary work has been put in to support the new Solaris OS from Sun. At
7588 this time, it can control and debug processes, but it is not capable of
7593 As always, many many bug fixes. The major areas were with g++, and mipsread.
7594 People using the MIPS-based platforms should experience fewer mysterious
7595 crashes and trashed symbol tables.
7597 *** Changes in GDB-4.4:
7599 * New machines supported (host and target)
7601 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7603 BSD Reno on Vax vax-dec-bsd
7604 Ultrix on Vax vax-dec-ultrix
7606 * New machines supported (target)
7608 AMD 29000 embedded, using EBMON a29k-none-none
7612 GDB continues to improve its handling of C++. `References' work better.
7613 The demangler has also been improved, and now deals with symbols mangled as
7614 per the Annotated C++ Reference Guide.
7616 GDB also now handles `stabs' symbol information embedded in MIPS
7617 `ecoff' symbol tables. Since the ecoff format was not easily
7618 extensible to handle new languages such as C++, this appeared to be a
7619 good way to put C++ debugging info into MIPS binaries. This option
7620 will be supported in the GNU C compiler, version 2, when it is
7623 * New features for SVR4
7625 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7626 shared libraries. Debugging dynamically linked programs should present
7627 only minor differences from debugging statically linked programs.
7629 The `info proc' command will print out information about any process
7630 on an SVR4 system (including the one you are debugging). At the moment,
7631 it prints the address mappings of the process.
7633 If you bring up GDB on another SVR4 system, please send mail to
7634 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7636 * Better dynamic linking support in SunOS
7638 Reading symbols from shared libraries which contain debugging symbols
7639 now works properly. However, there remain issues such as automatic
7640 skipping of `transfer vector' code during function calls, which
7641 make it harder to debug code in a shared library, than to debug the
7642 same code linked statically.
7646 GDB is now using the latest `getopt' routines from the FSF. This
7647 version accepts the -- prefix for options with long names. GDB will
7648 continue to accept the old forms (-option and +option) as well.
7649 Various single letter abbreviations for options have been explicity
7650 added to the option table so that they won't get overshadowed in the
7651 future by other options that begin with the same letter.
7655 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7656 Many assorted bugs have been handled. Many more remain to be handled.
7657 See the various ChangeLog files (primarily in gdb and bfd) for details.
7660 *** Changes in GDB-4.3:
7662 * New machines supported (host and target)
7664 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7665 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7666 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7668 * Almost SCO Unix support
7670 We had hoped to support:
7671 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7672 (except for core file support), but we discovered very late in the release
7673 that it has problems with process groups that render gdb unusable. Sorry
7674 about that. I encourage people to fix it and post the fixes.
7676 * Preliminary ELF and DWARF support
7678 GDB can read ELF object files on System V Release 4, and can handle
7679 debugging records for C, in DWARF format, in ELF files. This support
7680 is preliminary. If you bring up GDB on another SVR4 system, please
7681 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7686 GDB now uses the latest `readline' library. One user-visible change
7687 is that two tabs will list possible command completions, which previously
7688 required typing M-? (meta-question mark, or ESC ?).
7692 The `stepi' bug that many of you noticed has been squashed.
7693 Many bugs in C++ have been handled. Many more remain to be handled.
7694 See the various ChangeLog files (primarily in gdb and bfd) for details.
7696 * State of the MIPS world (in case you wondered):
7698 GDB can understand the symbol tables emitted by the compilers
7699 supplied by most vendors of MIPS-based machines, including DEC. These
7700 symbol tables are in a format that essentially nobody else uses.
7702 Some versions of gcc come with an assembler post-processor called
7703 mips-tfile. This program is required if you want to do source-level
7704 debugging of gcc-compiled programs. I believe FSF does not ship
7705 mips-tfile with gcc version 1, but it will eventually come with gcc
7708 Debugging of g++ output remains a problem. g++ version 1.xx does not
7709 really support it at all. (If you're lucky, you should be able to get
7710 line numbers and stack traces to work, but no parameters or local
7711 variables.) With some work it should be possible to improve the
7714 When gcc version 2 is released, you will have somewhat better luck.
7715 However, even then you will get confusing results for inheritance and
7718 We will eventually provide full debugging of g++ output on
7719 DECstations. This will probably involve some kind of stabs-in-ecoff
7720 encapulation, but the details have not been worked out yet.
7723 *** Changes in GDB-4.2:
7725 * Improved configuration
7727 Only one copy of `configure' exists now, and it is not self-modifying.
7728 Porting BFD is simpler.
7732 The `step' and `next' commands now only stop at the first instruction
7733 of a source line. This prevents the multiple stops that used to occur
7734 in switch statements, for-loops, etc. `Step' continues to stop if a
7735 function that has debugging information is called within the line.
7739 Lots of small bugs fixed. More remain.
7741 * New host supported (not target)
7743 Intel 386 PC clone running Mach i386-none-mach
7746 *** Changes in GDB-4.1:
7748 * Multiple source language support
7750 GDB now has internal scaffolding to handle several source languages.
7751 It determines the type of each source file from its filename extension,
7752 and will switch expression parsing and number formatting to match the
7753 language of the function in the currently selected stack frame.
7754 You can also specifically set the language to be used, with
7755 `set language c' or `set language modula-2'.
7759 GDB now has preliminary support for the GNU Modula-2 compiler,
7760 currently under development at the State University of New York at
7761 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7762 continue through the fall of 1991 and into 1992.
7764 Other Modula-2 compilers are currently not supported, and attempting to
7765 debug programs compiled with them will likely result in an error as the
7766 symbol table is read. Feel free to work on it, though!
7768 There are hooks in GDB for strict type checking and range checking,
7769 in the `Modula-2 philosophy', but they do not currently work.
7773 GDB can now write to executable and core files (e.g. patch
7774 a variable's value). You must turn this switch on, specify
7775 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7776 by assigning a new value to a variable. Modifications take
7779 * Automatic SunOS shared library reading
7781 When you run your program, GDB automatically determines where its
7782 shared libraries (if any) have been loaded, and reads their symbols.
7783 The `share' command is no longer needed. This also works when
7784 examining core files.
7788 You can specify the number of lines that the `list' command shows.
7791 * New machines supported (host and target)
7793 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7794 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7795 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7797 * New hosts supported (not targets)
7799 IBM RT/PC: romp-ibm-aix or rtpc
7801 * New targets supported (not hosts)
7803 AMD 29000 embedded with COFF a29k-none-coff
7804 AMD 29000 embedded with a.out a29k-none-aout
7805 Ultracomputer remote kernel debug a29k-nyu-kern
7807 * New remote interfaces
7813 *** Changes in GDB-4.0:
7817 Wide output is wrapped at good places to make the output more readable.
7819 Gdb now supports cross-debugging from a host machine of one type to a
7820 target machine of another type. Communication with the target system
7821 is over serial lines. The ``target'' command handles connecting to the
7822 remote system; the ``load'' command will download a program into the
7823 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7824 also supports debugging of realtime processes running under VxWorks,
7825 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7826 stub on the target system.
7828 New CPUs supported include the AMD 29000 and Intel 960.
7830 GDB now reads object files and symbol tables via a ``binary file''
7831 library, which allows a single copy of GDB to debug programs of multiple
7832 object file types such as a.out and coff.
7834 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7835 refcard.dvi and refcard.ps are available to format it).
7838 * Control-Variable user interface simplified
7840 All variables that control the operation of the debugger can be set
7841 by the ``set'' command, and displayed by the ``show'' command.
7843 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7844 ``Show prompt'' produces the response:
7845 Gdb's prompt is new-gdb=>.
7847 What follows are the NEW set commands. The command ``help set'' will
7848 print a complete list of old and new set commands. ``help set FOO''
7849 will give a longer description of the variable FOO. ``show'' will show
7850 all of the variable descriptions and their current settings.
7852 confirm on/off: Enables warning questions for operations that are
7853 hard to recover from, e.g. rerunning the program while
7854 it is already running. Default is ON.
7856 editing on/off: Enables EMACS style command line editing
7857 of input. Previous lines can be recalled with
7858 control-P, the current line can be edited with control-B,
7859 you can search for commands with control-R, etc.
7862 history filename NAME: NAME is where the gdb command history
7863 will be stored. The default is .gdb_history,
7864 or the value of the environment variable
7867 history size N: The size, in commands, of the command history. The
7868 default is 256, or the value of the environment variable
7871 history save on/off: If this value is set to ON, the history file will
7872 be saved after exiting gdb. If set to OFF, the
7873 file will not be saved. The default is OFF.
7875 history expansion on/off: If this value is set to ON, then csh-like
7876 history expansion will be performed on
7877 command line input. The default is OFF.
7879 radix N: Sets the default radix for input and output. It can be set
7880 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7881 in the current radix, so "set radix 10" is always a no-op.
7883 height N: This integer value is the number of lines on a page. Default
7884 is 24, the current `stty rows'' setting, or the ``li#''
7885 setting from the termcap entry matching the environment
7888 width N: This integer value is the number of characters on a line.
7889 Default is 80, the current `stty cols'' setting, or the ``co#''
7890 setting from the termcap entry matching the environment
7893 Note: ``set screensize'' is obsolete. Use ``set height'' and
7894 ``set width'' instead.
7896 print address on/off: Print memory addresses in various command displays,
7897 such as stack traces and structure values. Gdb looks
7898 more ``symbolic'' if you turn this off; it looks more
7899 ``machine level'' with it on. Default is ON.
7901 print array on/off: Prettyprint arrays. New convenient format! Default
7904 print demangle on/off: Print C++ symbols in "source" form if on,
7907 print asm-demangle on/off: Same, for assembler level printouts
7910 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7913 * Support for Epoch Environment.
7915 The epoch environment is a version of Emacs v18 with windowing. One
7916 new command, ``inspect'', is identical to ``print'', except that if you
7917 are running in the epoch environment, the value is printed in its own
7921 * Support for Shared Libraries
7923 GDB can now debug programs and core files that use SunOS shared libraries.
7924 Symbols from a shared library cannot be referenced
7925 before the shared library has been linked with the program (this
7926 happens after you type ``run'' and before the function main() is entered).
7927 At any time after this linking (including when examining core files
7928 from dynamically linked programs), gdb reads the symbols from each
7929 shared library when you type the ``sharedlibrary'' command.
7930 It can be abbreviated ``share''.
7932 sharedlibrary REGEXP: Load shared object library symbols for files
7933 matching a unix regular expression. No argument
7934 indicates to load symbols for all shared libraries.
7936 info sharedlibrary: Status of loaded shared libraries.
7941 A watchpoint stops execution of a program whenever the value of an
7942 expression changes. Checking for this slows down execution
7943 tremendously whenever you are in the scope of the expression, but is
7944 quite useful for catching tough ``bit-spreader'' or pointer misuse
7945 problems. Some machines such as the 386 have hardware for doing this
7946 more quickly, and future versions of gdb will use this hardware.
7948 watch EXP: Set a watchpoint (breakpoint) for an expression.
7950 info watchpoints: Information about your watchpoints.
7952 delete N: Deletes watchpoint number N (same as breakpoints).
7953 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7954 enable N: Re-enables watchpoint number N (same as breakpoints).
7957 * C++ multiple inheritance
7959 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7962 * C++ exception handling
7964 Gdb now supports limited C++ exception handling. Besides the existing
7965 ability to breakpoint on an exception handler, gdb can breakpoint on
7966 the raising of an exception (before the stack is peeled back to the
7969 catch FOO: If there is a FOO exception handler in the dynamic scope,
7970 set a breakpoint to catch exceptions which may be raised there.
7971 Multiple exceptions (``catch foo bar baz'') may be caught.
7973 info catch: Lists all exceptions which may be caught in the
7974 current stack frame.
7977 * Minor command changes
7979 The command ``call func (arg, arg, ...)'' now acts like the print
7980 command, except it does not print or save a value if the function's result
7981 is void. This is similar to dbx usage.
7983 The ``up'' and ``down'' commands now always print the frame they end up
7984 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7985 frames without printing.
7987 * New directory command
7989 'dir' now adds directories to the FRONT of the source search path.
7990 The path starts off empty. Source files that contain debug information
7991 about the directory in which they were compiled can be found even
7992 with an empty path; Sun CC and GCC include this information. If GDB can't
7993 find your source file in the current directory, type "dir .".
7995 * Configuring GDB for compilation
7997 For normal use, type ``./configure host''. See README or gdb.texinfo
8000 GDB now handles cross debugging. If you are remotely debugging between
8001 two different machines, type ``./configure host -target=targ''.
8002 Host is the machine where GDB will run; targ is the machine
8003 where the program that you are debugging will run.