1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 10
6 * GDB now supports general memory tagging functionality if the underlying
7 architecture supports the proper primitives and hooks. Currently this is
8 enabled only for AArch64 MTE.
12 - Additional information when the inferior crashes with a SIGSEGV caused by
13 a memory tag violation.
15 - A new modifier 'm' for the "x" command, which displays allocation tags for a
16 particular memory range.
18 - Display of memory tag mismatches by "print", for addresses and
19 pointers, if memory tagging is supported by the architecture.
21 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
26 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
28 The MI -break-insert and -dprintf-insert commands now support a
29 new "--qualified" option that makes GDB interpret a specified
30 function name as a complete fully-qualified name. This is the
31 equivalent of the CLI's "break -qualified" and "dprintf
34 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
36 The MI -break-insert and -dprintf-insert commands now support a
37 '--force-condition' flag to forcibly define a condition even when
38 the condition is invalid at all locations of the breakpoint. This
39 is equivalent to the '-force-condition' flag of the CLI's "break"
42 ** '-break-condition --force'
44 The MI -break-condition command now supports a '--force' flag to
45 forcibly define a condition even when the condition is invalid at
46 all locations of the selected breakpoint. This is equivalent to
47 the '-force' flag of the CLI's "cond" command.
49 * GDB now supports core file debugging for x86_64 Cygwin programs.
51 * GDB will now look for the .gdbinit file in a config directory before
52 looking for ~/.gdbinit. The file is searched for in the following
53 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
54 $HOME/.gdbinit. On Apple hosts the search order is instead:
55 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
57 * GDB now supports fixed point types which are described in DWARF
58 as base types with a fixed-point encoding. Additionally, support
59 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
62 For Ada, this allows support for fixed point types without requiring
63 the use of the GNAT encoding (based on information added to the type's
64 name following a GNAT-specific format).
66 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
67 or ~/.gdbearlyinit if these files are present. These files are
68 processed earlier than any of the other initialization files and
69 can affect parts of GDB's startup that previously had already been
70 completed before the initialization files were read, for example
71 styling of the initial GDB greeting.
73 * GDB now has two new options "--early-init-command" and
74 "--early-init-eval-command" with corresponding short options "-eix"
75 and "-eiex" that allow options (that would normally appear in a
76 gdbearlyinit file) to be passed on the command line.
82 Control the display of debug output about GDB's event loop.
84 set print memory-tag-violations
85 show print memory-tag-violations
86 Control whether to display additional information about memory tag violations
87 when printing pointers and addresses. Architecture support for memory
88 tagging is required for this option to have an effect.
90 maintenance flush symbol-cache
91 maintenance flush register-cache
92 These new commands are equivalent to the already existing commands
93 'maintenance flush-symbol-cache' and 'flushregs' respectively.
95 maintenance flush dcache
96 A new command to flush the dcache.
98 maintenance info target-sections
99 Print GDB's internal target sections table.
101 memory-tag show-logical-tag POINTER
102 Print the logical tag for POINTER.
103 memory-tag with-logical-tag POINTER TAG
104 Print POINTER with logical tag TAG.
105 memory-tag show-allocation-tag ADDRESS
106 Print the allocation tag for ADDRESS.
107 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
108 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
109 memory-tag check POINTER
110 Validate that POINTER's logical tag matches the allocation tag.
112 set startup-quietly on|off
114 When 'on', this causes GDB to act as if "-silent" were passed on the
115 command line. This command needs to be added to an early
116 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
119 set print type hex on|off
121 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
122 and offsets of struct members. When 'off', decimal notation is used.
124 set python ignore-environment on|off
125 show python ignore-environment
126 When 'on', this causes GDB's builtin Python to ignore any
127 environment variables that would otherwise affect how Python
128 behaves. This command needs to be added to an early initialization
129 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
131 set python dont-write-bytecode auto|on|off
132 show python dont-write-bytecode
133 When 'on', this causes GDB's builtin Python to not write any
134 byte-code (.pyc files) to disk. This command needs to be added to
135 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
136 order to affect GDB. When 'off' byte-code will always be written.
137 When set to 'auto' (the default) Python will check the
138 PYTHONDONTWRITEBYTECODE environment variable.
142 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
143 [-force-condition] [if CONDITION]
144 This command would previously refuse setting a breakpoint if the
145 CONDITION expression is invalid at a location. It now accepts and
146 defines the breakpoint if there is at least one location at which
147 the CONDITION is valid. The locations for which the CONDITION is
148 invalid, are automatically disabled. If CONDITION is invalid at all
149 of the locations, setting the breakpoint is still rejected. However,
150 the '-force-condition' flag can be used in this case for forcing GDB to
151 define the breakpoint, making all the current locations automatically
152 disabled. This may be useful if the user knows the condition will
153 become meaningful at a future location, e.g. due to a shared library
156 condition [-force] N COND
157 The behavior of this command is changed the same way for the 'break'
158 command as explained above. The '-force' flag can be used to force
159 GDB into defining the condition even when COND is invalid for all the
160 current locations of breakpoint N.
163 maintenance flush-symbol-cache
164 These commands are deprecated in favor of the new commands
165 'maintenance flush register-cache' and 'maintenance flush
166 symbol-cache' respectively.
168 set style version foreground COLOR
169 set style version background COLOR
170 set style version intensity VALUE
171 Control the styling of GDB's version number text.
174 When the ID parameter is omitted, then this command prints information
175 about the current inferior. When the ID parameter is present, the
176 behavior of the command is unchanged and have the inferior ID become
177 the current inferior.
179 maintenance info sections
180 The ALLOBJ keyword has been replaced with an -all-objects command
181 line flag. It is now possible to filter which sections are printed
182 even when -all-objects is passed.
184 ptype[/FLAGS] TYPE | EXPRESSION
185 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
186 notation is used when printing sizes and offsets of struct members.
187 When '/d' is set, decimal notation is used when printing sizes and
188 offsets of struct members. Default behavior is given by 'show print
191 * Removed targets and native configurations
193 ARM Symbian arm*-*-symbianelf*
198 Request the remote to send allocation tags for a particular memory range.
200 Request the remote to store the specified allocation tags to the requested
203 *** Changes in GDB 10
205 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
206 and "org.gnu.gdb.arc.aux". The old names are still supported but
207 must be considered obsolete. They will be deprecated after some
210 * Help and apropos commands will now show the documentation of a
211 command only once, even if that command has one or more aliases.
212 These commands now show the command name, then all of its aliases,
213 and finally the description of the command.
215 * 'help aliases' now shows only the user defined aliases. GDB predefined
216 aliases are shown together with their aliased command.
218 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
219 debugging information as well as source code.
221 When built with debuginfod, GDB can automatically query debuginfod
222 servers for the separate debug files and source code of the executable
225 To build GDB with debuginfod, pass --with-debuginfod to configure (this
226 requires libdebuginfod, the debuginfod client library).
228 debuginfod is distributed with elfutils, starting with version 0.178.
230 You can get the latest version from https://sourceware.org/elfutils.
232 * Multi-target debugging support
234 GDB now supports debugging multiple target connections
235 simultaneously. For example, you can now have each inferior
236 connected to different remote servers running in different machines,
237 or have one inferior debugging a local native process, an inferior
238 debugging a core dump, etc.
240 This support is experimental and comes with some limitations -- you
241 can only resume multiple targets simultaneously if all targets
242 support non-stop mode, and all remote stubs or servers must support
243 the same set of remote protocol features exactly. See also "info
244 connections" and "add-inferior -no-connection" below, and "maint set
245 target-non-stop" in the user manual.
247 * New features in the GDB remote stub, GDBserver
249 ** GDBserver is now supported on ARC GNU/Linux.
251 ** GDBserver is now supported on RISC-V GNU/Linux.
253 ** GDBserver no longer supports these host triplets:
264 i[34567]86-*-mingw32ce*
266 * Debugging MS-Windows processes now sets $_exitsignal when the
267 inferior is terminated by a signal, instead of setting $_exitcode.
269 * Multithreaded symbol loading has now been enabled by default on systems
270 that support it (see entry for GDB 9, below), providing faster
271 performance for programs with many symbols.
273 * The $_siginfo convenience variable now also works on Windows targets,
274 and will display the EXCEPTION_RECORD of the last handled exception.
276 * TUI windows can now be arranged horizontally.
278 * The command history filename can now be set to the empty string
279 either using 'set history filename' or by setting 'GDBHISTFILE=' in
280 the environment. The effect of setting this filename to the empty
281 string is that GDB will not try to load any previous command
284 * On Windows targets, it is now possible to debug 32-bit programs with a
289 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
290 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
291 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
292 running process, this new option indicates whether to detect
293 a mismatch between the current executable file loaded by GDB and the
294 executable file used to start the process. If 'ask', the default,
295 display a warning and ask the user whether to load the process
296 executable file; if 'warn', just display a warning; if 'off', don't
297 attempt to detect a mismatch.
299 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
300 Define a new TUI layout, specifying its name and the windows that
303 maintenance print xml-tdesc [FILE]
304 Prints the current target description as an XML document. If the
305 optional FILE is provided (which is an XML target description) then
306 the target description is read from FILE into GDB, and then
309 maintenance print core-file-backed-mappings
310 Prints file-backed mappings loaded from a core file's note section.
311 Output is expected to be similar to that of "info proc mappings".
313 set debug fortran-array-slicing on|off
314 show debug fortran-array-slicing
315 Print debugging when taking slices of Fortran arrays.
317 set fortran repack-array-slices on|off
318 show fortran repack-array-slices
319 When taking slices from Fortran arrays and strings, if the slice is
320 non-contiguous within the original value then, when this option is
321 on, the new value will be repacked into a single contiguous value.
322 When this option is off, then the value returned will consist of a
323 descriptor that describes the slice within the memory of the
324 original parent value.
328 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
329 The alias command can now specify default args for an alias.
330 GDB automatically prepends the alias default args to the argument list
331 provided explicitly by the user.
332 For example, to have a backtrace with full details, you can define
334 'alias bt_ALL = backtrace -entry-values both -frame-arg all
335 -past-main -past-entry -full'.
336 Alias default arguments can also use a set of nested 'with' commands,
337 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
338 defines the alias pp10 that will pretty print a maximum of 10 elements
339 of the given expression (if the expression is an array).
343 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
348 ** gdb.register_window_type can be used to implement new TUI windows
351 ** Dynamic types can now be queried. gdb.Type has a new attribute,
352 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
353 field of a dynamic type may have None for its "bitpos" attribute
356 ** Commands written in Python can be in the "TUI" help class by
357 registering with the new constant gdb.COMMAND_TUI.
359 ** New method gdb.PendingFrame.architecture () to retrieve the
360 architecture of the pending frame.
362 ** New gdb.Architecture.registers method that returns a
363 gdb.RegisterDescriptorIterator object, an iterator that returns
364 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
365 way to query the registers available for an architecture.
367 ** New gdb.Architecture.register_groups method that returns a
368 gdb.RegisterGroupIterator object, an iterator that returns
369 gdb.RegisterGroup objects. The new RegisterGroup is a way to
370 discover the available register groups.
374 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
376 ** Procedures 'memory-port-read-buffer-size',
377 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
378 and 'set-memory-port-write-buffer-size!' are deprecated. When
379 using Guile 2.2 and later, users who need to control the size of
380 a memory port's internal buffer can use the 'setvbuf' procedure.
384 * 'thread-exited' event is now available in the annotations interface.
386 * New built-in convenience variables $_gdb_major and $_gdb_minor
387 provide the GDB version. They are handy for conditionally using
388 features available only in or since specific GDB versions, in
389 scripts that should work error-free with many different versions,
390 such as in system-wide init files.
392 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
393 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
394 of the GDB settings and the GDB maintenance settings. They are handy
395 for changing the logic of user defined commands depending on the
396 current GDB settings.
398 * GDB now supports Thread Local Storage (TLS) variables on several
399 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
400 architectures require kernel changes. TLS is not yet supported for
401 amd64 and i386 process core dumps.
403 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
404 addresses that required unmasking are shown in the backtrace with the
407 * Two new convenience functions $_cimag and $_creal that extract the
408 imaginary and real parts respectively from complex numbers.
410 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
411 provide the exitcode or exit status of the shell commands launched by
412 GDB commands such as "shell", "pipe" and "make".
414 * The command define-prefix can now define user defined prefix commands.
415 User defined commands can now be defined using these user defined prefix
418 * Command names can now use the . character.
420 * The RX port now supports XML target descriptions.
422 * GDB now shows the Ada task names at more places, e.g. in task switching
425 * GDB can now be compiled with Python 3 on Windows.
427 * New convenience variable $_ada_exception holds the address of the
428 Ada exception being thrown. This is set by Ada-related catchpoints.
430 * GDB can now place breakpoints on nested functions and subroutines in
431 Fortran code. The '::' operator can be used between parent and
432 child scopes when placing breakpoints, for example:
434 (gdb) break outer_function::inner_function
436 The 'outer_function::' prefix is only needed if 'inner_function' is
437 not visible in the current scope.
439 * In addition to the system-wide gdbinit file, if configured with
440 --with-system-gdbinit-dir, GDB will now also load files in that directory
441 as system gdbinit files, unless the -nx or -n flag is provided. Files
442 with extensions .gdb, .py and .scm are supported as long as GDB was
443 compiled with support for that language.
445 * GDB now supports multithreaded symbol loading for higher performance.
446 This feature is still in testing, so it is disabled by default. You
447 can turn it on using 'maint set worker-threads unlimited'.
451 ** The gdb.Value type has a new method 'format_string' which returns a
452 string representing the value. The formatting is controlled by the
453 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
454 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
455 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
457 ** gdb.Type has a new property 'objfile' which returns the objfile the
460 ** The frame information printed by the python frame filtering code
461 is now consistent with what the 'backtrace' command prints when
462 there are no filters, or when the 'backtrace' '-no-filters' option
465 ** The new function gdb.lookup_static_symbol can be used to look up
466 symbols with static linkage.
468 ** The new function gdb.lookup_static_symbols can be used to look up
469 all static symbols with static linkage.
471 ** gdb.Objfile has new methods 'lookup_global_symbol' and
472 'lookup_static_symbol' to lookup a symbol from this objfile only.
474 ** gdb.Block now supports the dictionary syntax for accessing symbols in
475 this block (e.g. block['local_variable']).
479 | [COMMAND] | SHELL_COMMAND
480 | -d DELIM COMMAND DELIM SHELL_COMMAND
481 pipe [COMMAND] | SHELL_COMMAND
482 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
483 Executes COMMAND and sends its output to SHELL_COMMAND.
484 With no COMMAND, repeat the last executed command
485 and send its output to SHELL_COMMAND.
487 define-prefix COMMAND
488 Define or mark a command as a user-defined prefix command.
490 with SETTING [VALUE] [-- COMMAND]
491 w SETTING [VALUE] [-- COMMAND]
492 Temporarily set SETTING, run COMMAND, and restore SETTING.
493 Usage: with SETTING -- COMMAND
494 With no COMMAND, repeats the last executed command.
495 SETTING is any GDB setting you can change with the "set"
496 subcommands. For example, 'with language c -- print someobj'
497 temporarily switches to the C language in order to print someobj.
498 Settings can be combined: 'w lang c -- w print elements unlimited --
499 usercmd' switches to the C language and runs usercmd with no limit
500 of array elements to print.
502 maint with SETTING [VALUE] [-- COMMAND]
503 Like "with", but works with "maintenance set" settings.
505 set may-call-functions [on|off]
506 show may-call-functions
507 This controls whether GDB will attempt to call functions in
508 the program, such as with expressions in the print command. It
509 defaults to on. Calling functions in the program being debugged
510 can have undesired side effects. It is now possible to forbid
511 such function calls. If function calls are forbidden, GDB will throw
512 an error when a command (such as print expression) calls a function
515 set print finish [on|off]
517 This controls whether the `finish' command will display the value
518 that is returned by the current function. When `off', the value is
519 still entered into the value history, but it is not printed. The
524 Allows deeply nested structures to be simplified when printing by
525 replacing deeply nested parts (beyond the max-depth) with ellipses.
526 The default max-depth is 20, but this can be set to unlimited to get
527 the old behavior back.
529 set print raw-values [on|off]
530 show print raw-values
531 By default, GDB applies the enabled pretty printers when printing a
532 value. This allows to ignore the enabled pretty printers for a series
533 of commands. The default is 'off'.
535 set logging debugredirect [on|off]
536 By default, GDB debug output will go to both the terminal and the logfile.
537 Set if you want debug output to go only to the log file.
539 set style title foreground COLOR
540 set style title background COLOR
541 set style title intensity VALUE
542 Control the styling of titles.
544 set style highlight foreground COLOR
545 set style highlight background COLOR
546 set style highlight intensity VALUE
547 Control the styling of highlightings.
549 maint set worker-threads
550 maint show worker-threads
551 Control the number of worker threads that can be used by GDB. The
552 default is 0. "unlimited" lets GDB choose a number that is
553 reasonable. Currently worker threads are only used when demangling
554 the names of linker symbols.
556 set style tui-border foreground COLOR
557 set style tui-border background COLOR
558 Control the styling of TUI borders.
560 set style tui-active-border foreground COLOR
561 set style tui-active-border background COLOR
562 Control the styling of the active TUI border.
564 maint set test-settings KIND
565 maint show test-settings KIND
566 A set of commands used by the testsuite for exercising the settings
569 maint set tui-resize-message [on|off]
570 maint show tui-resize-message
571 Control whether GDB prints a message each time the terminal is
572 resized when in TUI mode. This is primarily useful for testing the
575 set print frame-info [short-location|location|location-and-address
576 |source-and-location|source-line|auto]
577 show print frame-info
578 This controls what frame information is printed by the commands printing
579 a frame. This setting will e.g. influence the behaviour of 'backtrace',
580 'frame', 'stepi'. The python frame filtering also respect this setting.
581 The 'backtrace' '-frame-info' option can override this global setting.
583 set tui compact-source
584 show tui compact-source
586 Enable the "compact" display mode for the TUI source window. The
587 compact display uses only as much space as is needed for the line
588 numbers in the current file, and only a single space to separate the
589 line numbers from the source.
591 info modules [-q] [REGEXP]
592 Return a list of Fortran modules matching REGEXP, or all modules if
595 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
596 Return a list of functions within all modules, grouped by module.
597 The list of functions can be restricted with the optional regular
598 expressions. MODULE_REGEXP matches against the module name,
599 TYPE_REGEXP matches against the function type signature, and REGEXP
600 matches against the function name.
602 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
603 Return a list of variables within all modules, grouped by module.
604 The list of variables can be restricted with the optional regular
605 expressions. MODULE_REGEXP matches against the module name,
606 TYPE_REGEXP matches against the variable type, and REGEXP matches
607 against the variable name.
609 set debug remote-packet-max-chars
610 show debug remote-packet-max-chars
611 Controls the number of characters to output in a remote packet when using
613 The default is 512 bytes.
616 Lists the target connections currently in use.
621 The "help" command uses the title style to enhance the
622 readibility of its output by styling the classes and
626 Similarly to "help", the "apropos" command also uses the
627 title style for the command names. "apropos" accepts now
628 a flag "-v" (verbose) to show the full documentation
629 of matching commands and to use the highlight style to mark
630 the documentation parts matching REGEXP.
634 The GDB printf and eval commands can now print C-style and Ada-style
635 string convenience variables without calling functions in the program.
636 This allows to do formatted printing of strings without having
637 a running inferior, or when debugging a core dump.
639 info sources [-dirname | -basename] [--] [REGEXP]
640 This command has now optional arguments to only print the files
641 whose names match REGEXP. The arguments -dirname and -basename
642 allow to restrict matching respectively to the dirname and basename
646 The "show style" and its subcommands are now styling
647 a style name in their output using its own style, to help
648 the user visualize the different styles.
650 set print frame-arguments
651 The new value 'presence' indicates to only indicate the presence of
652 arguments using ..., instead of printing argument names and values.
654 set print raw-frame-arguments
655 show print raw-frame-arguments
657 These commands replace the similarly-named "set/show print raw
658 frame-arguments" commands (now with a dash instead of a space). The
659 old commands are now deprecated and may be removed in a future
662 add-inferior [-no-connection]
663 The add-inferior command now supports a "-no-connection" flag that
664 makes the new inferior start with no target connection associated.
665 By default, the new inferior inherits the target connection of the
666 current inferior. See also "info connections".
669 This command's output now includes a new "Connection" column
670 indicating which target connection an inferior is bound to. See
671 "info connections" above.
673 maint test-options require-delimiter
674 maint test-options unknown-is-error
675 maint test-options unknown-is-operand
676 maint show test-options-completion-result
677 Commands used by the testsuite to validate the command options
680 focus, winheight, +, -, >, <
681 These commands are now case-sensitive.
683 * New command options, command completion
685 GDB now has a standard infrastructure to support dash-style command
686 options ('-OPT'). One benefit is that commands that use it can
687 easily support completion of command line arguments. Try "CMD
688 -[TAB]" or "help CMD" to find options supported by a command. Over
689 time, we intend to migrate most commands to this infrastructure. A
690 number of commands got support for new command options in this
693 ** The "print" and "compile print" commands now support a number of
694 options that allow overriding relevant global print settings as
695 set by "set print" subcommands:
699 -array-indexes [on|off]
700 -elements NUMBER|unlimited
705 -repeats NUMBER|unlimited
706 -static-members [on|off]
711 Note that because the "print"/"compile print" commands accept
712 arbitrary expressions which may look like options (including
713 abbreviations), if you specify any command option, then you must
714 use a double dash ("--") to mark the end of argument processing.
716 ** The "backtrace" command now supports a number of options that
717 allow overriding relevant global print settings as set by "set
718 backtrace" and "set print" subcommands:
720 -entry-values no|only|preferred|if-needed|both|compact|default
721 -frame-arguments all|scalars|none
722 -raw-frame-arguments [on|off]
723 -frame-info auto|source-line|location|source-and-location
724 |location-and-address|short-location
728 In addition, the full/no-filters/hide qualifiers are now also
729 exposed as command options too:
735 ** The "frame apply", "tfaas" and "faas" commands similarly now
736 support the following options:
741 ** The new "info sources" options -dirname and -basename options
742 are using the standard '-OPT' infrastructure.
744 All options above can also be abbreviated. The argument of boolean
745 (on/off) options can be 0/1 too, and also the argument is assumed
746 "on" if omitted. This allows writing compact command invocations,
749 (gdb) p -ra -p -o 0 -- *myptr
751 The above is equivalent to:
753 (gdb) print -raw-values -pretty -object off -- *myptr
755 ** The "info types" command now supports the '-q' flag to disable
756 printing of some header information in a similar fashion to "info
757 variables" and "info functions".
759 ** The "info variables", "info functions", and "whereis" commands
760 now take a '-n' flag that excludes non-debug symbols (symbols
761 from the symbol table, not from the debug info such as DWARF)
764 * Completion improvements
766 ** GDB can now complete the options of the "thread apply all" and
767 "taas" commands, and their "-ascending" option can now be
770 ** GDB can now complete the options of the "info threads", "info
771 functions", "info variables", "info locals", and "info args"
774 ** GDB can now complete the options of the "compile file" and
775 "compile code" commands. The "compile file" command now
776 completes on filenames.
778 ** GDB can now complete the backtrace command's
779 "full/no-filters/hide" qualifiers.
781 * In settings, you can now abbreviate "unlimited".
783 E.g., "set print elements u" is now equivalent to "set print
789 This lists all the possible completions for the rest of the line, if it
790 were to be given as a command itself. This is intended for use by MI
791 frontends in cases when separate CLI and MI channels cannot be used.
793 -catch-throw, -catch-rethrow, and -catch-catch
794 These can be used to catch C++ exceptions in a similar fashion to
795 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
797 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
798 These commands are the MI equivalent of the CLI commands 'info
799 functions', 'info types', and 'info variables' respectively.
801 -symbol-info-modules, this is the MI equivalent of the CLI 'info
804 -symbol-info-module-functions and -symbol-info-module-variables.
805 These commands are the MI equivalent of the CLI commands 'info
806 module functions' and 'info module variables'.
810 ** The default version of the MI interpreter is now 3 (-i=mi3).
812 ** The output of information about multi-location breakpoints (which is
813 syntactically incorrect in MI 2) has changed in MI 3. This affects
814 the following commands and events:
818 - =breakpoint-created
819 - =breakpoint-modified
821 The -fix-multi-location-breakpoint-output command can be used to enable
822 this behavior with previous MI versions.
824 ** Backtraces and frames include a new optional field addr_flags which is
825 given after the addr field. On AArch64 this contains PAC if the address
826 has been masked in the frame. On all other targets the field is not
831 The testsuite now creates the files gdb.cmd (containing the arguments
832 used to launch GDB) and gdb.in (containing all the commands sent to
833 GDB) in the output directory for each test script. Multiple invocations
834 are appended with .1, .2, .3 etc.
836 * Building GDB and GDBserver now requires GNU make >= 3.82.
838 Using another implementation of the make program or an earlier version of
839 GNU make to build GDB or GDBserver is not supported.
841 * Building GDB now requires GNU readline >= 7.0.
843 GDB now bundles GNU readline 8.0, but if you choose to use
844 --with-system-readline, only readline >= 7.0 can be used.
846 * The TUI SingleKey keymap is now named "SingleKey". This can be used
847 from .inputrc to bind keys in this keymap. This feature is only
848 available when gdb is built against GNU readline 8.0 or later.
850 * Removed targets and native configurations
852 GDB no longer supports debugging the Cell Broadband Engine. This includes
853 both debugging standalone Cell/B.E. SPU applications and integrated debugging
854 of Cell/B.E. applications that use both the PPU and SPU architectures.
860 * Removed targets and native configurations
862 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
865 *** Changes in GDB 8.3
867 * GDB and GDBserver now support access to additional registers on
868 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
871 * GDB now has experimental support for the compilation and injection of
872 C++ source code into the inferior. This beta release does not include
873 support for several language features, such as templates, constructors,
876 This feature requires GCC 7.1 or higher built with libcp1.so
879 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
880 can be passed using the '[ADDRESS]:PORT' notation, or the regular
881 'ADDRESS:PORT' method.
883 * DWARF index cache: GDB can now automatically save indices of DWARF
884 symbols on disk to speed up further loading of the same binaries.
886 * Ada task switching is now supported on aarch64-elf targets when
887 debugging a program using the Ravenscar Profile. For more information,
888 see the "Tasking Support when using the Ravenscar Profile" section
889 in the GDB user manual.
891 * GDB in batch mode now exits with status 1 if the last command to be
894 * The RISC-V target now supports target descriptions.
896 * System call catchpoints now support system call aliases on FreeBSD.
897 When the ABI of a system call changes in FreeBSD, this is
898 implemented by leaving a compatibility system call using the old ABI
899 at the existing number and allocating a new system call number for
900 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
901 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
902 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
903 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
904 so that a system call catchpoint for the 'kevent' system call will
905 catch invocations of both the 'kevent' and 'freebsd11_kevent'
906 binaries. This ensures that 'kevent' system calls are caught for
907 binaries using either the old or new ABIs.
909 * Terminal styling is now available for the CLI and the TUI. GNU
910 Source Highlight can additionally be used to provide styling of
911 source code snippets. See the "set style" commands, below, for more
914 * Removed support for old demangling styles arm, edg, gnu, hp and
919 set debug compile-cplus-types
920 show debug compile-cplus-types
921 Control the display of debug output about type conversion in the
922 C++ compile feature. Commands have no effect while compiling
927 Control whether debug output about files/functions skipping is
930 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
931 Apply a command to some frames.
932 FLAG arguments allow to control what output to produce and how to handle
933 errors raised when applying COMMAND to a frame.
936 Apply a command to all threads (ignoring errors and empty output).
937 Shortcut for 'thread apply all -s COMMAND'.
940 Apply a command to all frames (ignoring errors and empty output).
941 Shortcut for 'frame apply all -s COMMAND'.
944 Apply a command to all frames of all threads (ignoring errors and empty
946 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
948 maint set dwarf unwinders (on|off)
949 maint show dwarf unwinders
950 Control whether DWARF unwinders can be used.
953 Display a list of open files for a process.
957 Changes to the "frame", "select-frame", and "info frame" CLI commands.
958 These commands all now take a frame specification which
959 is either a frame level, or one of the keywords 'level', 'address',
960 'function', or 'view' followed by a parameter. Selecting a frame by
961 address, or viewing a frame outside the current backtrace now
962 requires the use of a keyword. Selecting a frame by level is
963 unchanged. The MI comment "-stack-select-frame" is unchanged.
965 target remote FILENAME
966 target extended-remote FILENAME
967 If FILENAME is a Unix domain socket, GDB will attempt to connect
968 to this socket instead of opening FILENAME as a character device.
970 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
971 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
972 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
973 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
974 These commands can now print only the searched entities
975 matching the provided regexp(s), giving a condition
976 on the entity names or entity types. The flag -q disables
977 printing headers or informations messages.
983 These commands now determine the syntax for the shown entities
984 according to the language chosen by `set language'. In particular,
985 `set language auto' means to automatically choose the language of
988 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
989 The 'thread apply' command accepts new FLAG arguments.
990 FLAG arguments allow to control what output to produce and how to handle
991 errors raised when applying COMMAND to a thread.
993 set tui tab-width NCHARS
994 show tui tab-width NCHARS
995 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
997 set style enabled [on|off]
999 Enable or disable terminal styling. Styling is enabled by default
1000 on most hosts, but disabled by default when in batch mode.
1002 set style sources [on|off]
1004 Enable or disable source code styling. Source code styling is
1005 enabled by default, but only takes effect if styling in general is
1006 enabled, and if GDB was linked with GNU Source Highlight.
1008 set style filename foreground COLOR
1009 set style filename background COLOR
1010 set style filename intensity VALUE
1011 Control the styling of file names.
1013 set style function foreground COLOR
1014 set style function background COLOR
1015 set style function intensity VALUE
1016 Control the styling of function names.
1018 set style variable foreground COLOR
1019 set style variable background COLOR
1020 set style variable intensity VALUE
1021 Control the styling of variable names.
1023 set style address foreground COLOR
1024 set style address background COLOR
1025 set style address intensity VALUE
1026 Control the styling of addresses.
1030 ** The '-data-disassemble' MI command now accepts an '-a' option to
1031 disassemble the whole function surrounding the given program
1032 counter value or function name. Support for this feature can be
1033 verified by using the "-list-features" command, which should
1034 contain "data-disassemble-a-option".
1036 ** Command responses and notifications that include a frame now include
1037 the frame's architecture in a new "arch" attribute.
1039 * New native configurations
1041 GNU/Linux/RISC-V riscv*-*-linux*
1042 FreeBSD/riscv riscv*-*-freebsd*
1046 GNU/Linux/RISC-V riscv*-*-linux*
1047 CSKY ELF csky*-*-elf
1048 CSKY GNU/LINUX csky*-*-linux
1049 FreeBSD/riscv riscv*-*-freebsd*
1051 GNU/Linux/OpenRISC or1k*-*-linux*
1055 GDB no longer supports native debugging on versions of MS-Windows
1060 ** GDB no longer supports Python versions less than 2.6.
1062 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1063 space associated to that inferior.
1065 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1066 of objfiles associated to that program space.
1068 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1069 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1072 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1073 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1074 correct and did not work properly.
1076 ** The gdb.Value type has a new constructor, which is used to construct a
1077 gdb.Value from a Python buffer object and a gdb.Type.
1083 Enable or disable the undefined behavior sanitizer. This is
1084 disabled by default, but passing --enable-ubsan=yes or
1085 --enable-ubsan=auto to configure will enable it. Enabling this can
1086 cause a performance penalty. The undefined behavior sanitizer was
1087 first introduced in GCC 4.9.
1089 *** Changes in GDB 8.2
1091 * The 'set disassembler-options' command now supports specifying options
1092 for the MIPS target.
1094 * The 'symbol-file' command now accepts an '-o' option to add a relative
1095 offset to all sections.
1097 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1098 a relative offset to all sections, but it allows to override the load
1099 address of individual sections using '-s'.
1101 * The 'add-symbol-file' command no longer requires the second argument
1102 (address of the text section).
1104 * The endianness used with the 'set endian auto' mode in the absence of
1105 an executable selected for debugging is now the last endianness chosen
1106 either by one of the 'set endian big' and 'set endian little' commands
1107 or by inferring from the last executable used, rather than the startup
1110 * The pager now allows a "c" response, meaning to disable the pager
1111 for the rest of the current command.
1113 * The commands 'info variables/functions/types' now show the source line
1114 numbers of symbol definitions when available.
1116 * 'info proc' now works on running processes on FreeBSD systems and core
1117 files created on FreeBSD systems.
1119 * C expressions can now use _Alignof, and C++ expressions can now use
1122 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1123 the vector length while the process is running.
1129 Control display of debugging info regarding the FreeBSD native target.
1131 set|show varsize-limit
1132 This new setting allows the user to control the maximum size of Ada
1133 objects being printed when those objects have a variable type,
1134 instead of that maximum size being hardcoded to 65536 bytes.
1136 set|show record btrace cpu
1137 Controls the processor to be used for enabling errata workarounds for
1138 branch trace decode.
1140 maint check libthread-db
1141 Run integrity checks on the current inferior's thread debugging
1144 maint set check-libthread-db (on|off)
1145 maint show check-libthread-db
1146 Control whether to run integrity checks on inferior specific thread
1147 debugging libraries as they are loaded. The default is not to
1148 perform such checks.
1152 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1154 ** The commands attached to a breakpoint can be set by assigning to
1155 the breakpoint's "commands" field.
1157 ** gdb.execute can now execute multi-line gdb commands.
1159 ** The new functions gdb.convenience_variable and
1160 gdb.set_convenience_variable can be used to get and set the value
1161 of convenience variables.
1163 ** A gdb.Parameter will no longer print the "set" help text on an
1164 ordinary "set"; instead by default a "set" will be silent unless
1165 the get_set_string method returns a non-empty string.
1169 RiscV ELF riscv*-*-elf
1171 * Removed targets and native configurations
1173 m88k running OpenBSD m88*-*-openbsd*
1174 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1175 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1176 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1178 * Aarch64/Linux hardware watchpoints improvements
1180 Hardware watchpoints on unaligned addresses are now properly
1181 supported when running Linux kernel 4.10 or higher: read and access
1182 watchpoints are no longer spuriously missed, and all watchpoints
1183 lengths between 1 and 8 bytes are supported. On older kernels,
1184 watchpoints set on unaligned addresses are no longer missed, with
1185 the tradeoff that there is a possibility of false hits being
1190 --enable-codesign=CERT
1191 This can be used to invoke "codesign -s CERT" after building gdb.
1192 This option is useful on macOS, where code signing is required for
1193 gdb to work properly.
1195 --disable-gdbcli has been removed
1196 This is now silently accepted, but does nothing.
1198 *** Changes in GDB 8.1
1200 * GDB now supports dynamically creating arbitrary register groups specified
1201 in XML target descriptions. This allows for finer grain grouping of
1202 registers on systems with a large amount of registers.
1204 * The 'ptype' command now accepts a '/o' flag, which prints the
1205 offsets and sizes of fields in a struct, like the pahole(1) tool.
1207 * New "--readnever" command line option instructs GDB to not read each
1208 symbol file's symbolic debug information. This makes startup faster
1209 but at the expense of not being able to perform symbolic debugging.
1210 This option is intended for use cases where symbolic debugging will
1211 not be used, e.g., when you only need to dump the debuggee's core.
1213 * GDB now uses the GNU MPFR library, if available, to emulate target
1214 floating-point arithmetic during expression evaluation when the target
1215 uses different floating-point formats than the host. At least version
1216 3.1 of GNU MPFR is required.
1218 * GDB now supports access to the guarded-storage-control registers and the
1219 software-based guarded-storage broadcast control registers on IBM z14.
1221 * On Unix systems, GDB now supports transmitting environment variables
1222 that are to be set or unset to GDBserver. These variables will
1223 affect the environment to be passed to the remote inferior.
1225 To inform GDB of environment variables that are to be transmitted to
1226 GDBserver, use the "set environment" command. Only user set
1227 environment variables are sent to GDBserver.
1229 To inform GDB of environment variables that are to be unset before
1230 the remote inferior is started by the GDBserver, use the "unset
1231 environment" command.
1233 * Completion improvements
1235 ** GDB can now complete function parameters in linespecs and
1236 explicit locations without quoting. When setting breakpoints,
1237 quoting around functions names to help with TAB-completion is
1238 generally no longer necessary. For example, this now completes
1241 (gdb) b function(in[TAB]
1242 (gdb) b function(int)
1244 Related, GDB is no longer confused with completing functions in
1245 C++ anonymous namespaces:
1248 (gdb) b (anonymous namespace)::[TAB][TAB]
1249 (anonymous namespace)::a_function()
1250 (anonymous namespace)::b_function()
1252 ** GDB now has much improved linespec and explicit locations TAB
1253 completion support, that better understands what you're
1254 completing and offers better suggestions. For example, GDB no
1255 longer offers data symbols as possible completions when you're
1256 setting a breakpoint.
1258 ** GDB now TAB-completes label symbol names.
1260 ** The "complete" command now mimics TAB completion accurately.
1262 * New command line options (gcore)
1265 Dump all memory mappings.
1267 * Breakpoints on C++ functions are now set on all scopes by default
1269 By default, breakpoints on functions/methods are now interpreted as
1270 specifying all functions with the given name ignoring missing
1271 leading scopes (namespaces and classes).
1273 For example, assuming a C++ program with symbols named:
1278 both commands "break func()" and "break B::func()" set a breakpoint
1281 You can use the new flag "-qualified" to override this. This makes
1282 GDB interpret the specified function name as a complete
1283 fully-qualified name instead. For example, using the same C++
1284 program, the "break -q B::func" command sets a breakpoint on
1285 "B::func", only. A parameter has been added to the Python
1286 gdb.Breakpoint constructor to achieve the same result when creating
1287 a breakpoint from Python.
1289 * Breakpoints on functions marked with C++ ABI tags
1291 GDB can now set breakpoints on functions marked with C++ ABI tags
1292 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1293 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1295 Functions with a C++11 abi tag are demangled/displayed like this:
1297 function[abi:cxx11](int)
1300 You can now set a breakpoint on such functions simply as if they had
1303 (gdb) b function(int)
1305 Or if you need to disambiguate between tags, like:
1307 (gdb) b function[abi:other_tag](int)
1309 Tab completion was adjusted accordingly as well.
1313 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1314 gdb.new_thread are emitted. See the manual for further
1315 description of these.
1317 ** A new function, "gdb.rbreak" has been added to the Python API.
1318 This function allows the setting of a large number of breakpoints
1319 via a regex pattern in Python. See the manual for further details.
1321 ** Python breakpoints can now accept explicit locations. See the
1322 manual for a further description of this feature.
1325 * New features in the GDB remote stub, GDBserver
1327 ** GDBserver is now able to start inferior processes with a
1328 specified initial working directory.
1330 The user can set the desired working directory to be used from
1331 GDB using the new "set cwd" command.
1333 ** New "--selftest" command line option runs some GDBserver self
1334 tests. These self tests are disabled in releases.
1336 ** On Unix systems, GDBserver now does globbing expansion and variable
1337 substitution in inferior command line arguments.
1339 This is done by starting inferiors using a shell, like GDB does.
1340 See "set startup-with-shell" in the user manual for how to disable
1341 this from GDB when using "target extended-remote". When using
1342 "target remote", you can disable the startup with shell by using the
1343 new "--no-startup-with-shell" GDBserver command line option.
1345 ** On Unix systems, GDBserver now supports receiving environment
1346 variables that are to be set or unset from GDB. These variables
1347 will affect the environment to be passed to the inferior.
1349 * When catching an Ada exception raised with a message, GDB now prints
1350 the message in the catchpoint hit notification. In GDB/MI mode, that
1351 information is provided as an extra field named "exception-message"
1352 in the *stopped notification.
1354 * Trait objects can now be inspected When debugging Rust code. This
1355 requires compiler support which will appear in Rust 1.24.
1357 * New remote packets
1359 QEnvironmentHexEncoded
1360 Inform GDBserver of an environment variable that is to be passed to
1361 the inferior when starting it.
1364 Inform GDBserver of an environment variable that is to be unset
1365 before starting the remote inferior.
1368 Inform GDBserver that the environment should be reset (i.e.,
1369 user-set environment variables should be unset).
1372 Indicates whether the inferior must be started with a shell or not.
1375 Tell GDBserver that the inferior to be started should use a specific
1378 * The "maintenance print c-tdesc" command now takes an optional
1379 argument which is the file name of XML target description.
1381 * The "maintenance selftest" command now takes an optional argument to
1382 filter the tests to be run.
1384 * The "enable", and "disable" commands now accept a range of
1385 breakpoint locations, e.g. "enable 1.3-5".
1390 Set and show the current working directory for the inferior.
1392 set|show compile-gcc
1393 Set and show compilation command used for compiling and injecting code
1394 with the 'compile' commands.
1396 set debug separate-debug-file
1397 show debug separate-debug-file
1398 Control the display of debug output about separate debug file search.
1400 set dump-excluded-mappings
1401 show dump-excluded-mappings
1402 Control whether mappings marked with the VM_DONTDUMP flag should be
1403 dumped when generating a core file.
1405 maint info selftests
1406 List the registered selftests.
1409 Start the debugged program stopping at the first instruction.
1412 Control display of debugging messages related to OpenRISC targets.
1414 set|show print type nested-type-limit
1415 Set and show the limit of nesting level for nested types that the
1416 type printer will show.
1418 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1421 * Safer/improved support for debugging with no debug info
1423 GDB no longer assumes functions with no debug information return
1426 This means that GDB now refuses to call such functions unless you
1427 tell it the function's type, by either casting the call to the
1428 declared return type, or by casting the function to a function
1429 pointer of the right type, and calling that:
1431 (gdb) p getenv ("PATH")
1432 'getenv' has unknown return type; cast the call to its declared return type
1433 (gdb) p (char *) getenv ("PATH")
1434 $1 = 0x7fffffffe "/usr/local/bin:/"...
1435 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1436 $2 = 0x7fffffffe "/usr/local/bin:/"...
1438 Similarly, GDB no longer assumes that global variables with no debug
1439 info have type 'int', and refuses to print the variable's value
1440 unless you tell it the variable's type:
1443 'var' has unknown type; cast it to its declared type
1447 * New native configurations
1449 FreeBSD/aarch64 aarch64*-*-freebsd*
1450 FreeBSD/arm arm*-*-freebsd*
1454 FreeBSD/aarch64 aarch64*-*-freebsd*
1455 FreeBSD/arm arm*-*-freebsd*
1456 OpenRISC ELF or1k*-*-elf
1458 * Removed targets and native configurations
1460 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1462 *** Changes in GDB 8.0
1464 * GDB now supports access to the PKU register on GNU/Linux. The register is
1465 added by the Memory Protection Keys for Userspace feature which will be
1466 available in future Intel CPUs.
1468 * GDB now supports C++11 rvalue references.
1472 ** New functions to start, stop and access a running btrace recording.
1473 ** Rvalue references are now supported in gdb.Type.
1475 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1478 * Building GDB and GDBserver now requires a C++11 compiler.
1480 For example, GCC 4.8 or later.
1482 It is no longer possible to build GDB or GDBserver with a C
1483 compiler. The --disable-build-with-cxx configure option has been
1486 * Building GDB and GDBserver now requires GNU make >= 3.81.
1488 It is no longer supported to build GDB or GDBserver with another
1489 implementation of the make program or an earlier version of GNU make.
1491 * Native debugging on MS-Windows supports command-line redirection
1493 Command-line arguments used for starting programs on MS-Windows can
1494 now include redirection symbols supported by native Windows shells,
1495 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1496 as "run", "start", and "set args", as well as the corresponding MI
1499 * Support for thread names on MS-Windows.
1501 GDB now catches and handles the special exception that programs
1502 running on MS-Windows use to assign names to threads in the
1505 * Support for Java programs compiled with gcj has been removed.
1507 * User commands now accept an unlimited number of arguments.
1508 Previously, only up to 10 was accepted.
1510 * The "eval" command now expands user-defined command arguments.
1512 This makes it easier to process a variable number of arguments:
1517 eval "print $arg%d", $i
1522 * Target descriptions can now describe registers for sparc32 and sparc64.
1524 * GDB now supports DWARF version 5 (debug information format).
1525 Its .debug_names index is not yet supported.
1527 * New native configurations
1529 FreeBSD/mips mips*-*-freebsd
1533 Synopsys ARC arc*-*-elf32
1534 FreeBSD/mips mips*-*-freebsd
1536 * Removed targets and native configurations
1538 Alpha running FreeBSD alpha*-*-freebsd*
1539 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1544 Erases all the flash memory regions reported by the target.
1546 maint print arc arc-instruction address
1547 Print internal disassembler information about instruction at a given address.
1551 set disassembler-options
1552 show disassembler-options
1553 Controls the passing of target specific information to the disassembler.
1554 If it is necessary to specify more than one disassembler option then
1555 multiple options can be placed together into a comma separated list.
1556 The default value is the empty string. Currently, the only supported
1557 targets are ARM, PowerPC and S/390.
1562 Erases all the flash memory regions reported by the target. This is
1563 equivalent to the CLI command flash-erase.
1565 -file-list-shared-libraries
1566 List the shared libraries in the program. This is
1567 equivalent to the CLI command "info shared".
1570 Catchpoints stopping the program when Ada exceptions are
1571 handled. This is equivalent to the CLI command "catch handlers".
1573 *** Changes in GDB 7.12
1575 * GDB and GDBserver now build with a C++ compiler by default.
1577 The --enable-build-with-cxx configure option is now enabled by
1578 default. One must now explicitly configure with
1579 --disable-build-with-cxx in order to build with a C compiler. This
1580 option will be removed in a future release.
1582 * GDBserver now supports recording btrace without maintaining an active
1585 * GDB now supports a negative repeat count in the 'x' command to examine
1586 memory backward from the given address. For example:
1589 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1590 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1591 (gdb) x/-5i 0x0000000000400580
1592 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1593 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1594 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1595 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1596 0x40057b <main(int, char**)+25>:
1597 callq 0x400536 <Func1(int, char const*)>
1599 * Fortran: Support structures with fields of dynamic types and
1600 arrays of dynamic types.
1602 * The symbol dumping maintenance commands have new syntax.
1603 maint print symbols [-pc address] [--] [filename]
1604 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1605 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1606 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1607 maint print msymbols [-objfile objfile] [--] [filename]
1609 * GDB now supports multibit bitfields and enums in target register
1612 * New Python-based convenience function $_as_string(val), which returns
1613 the textual representation of a value. This function is especially
1614 useful to obtain the text label of an enum value.
1616 * Intel MPX bound violation handling.
1618 Segmentation faults caused by a Intel MPX boundary violation
1619 now display the kind of violation (upper or lower), the memory
1620 address accessed and the memory bounds, along with the usual
1621 signal received and code location.
1625 Program received signal SIGSEGV, Segmentation fault
1626 Upper bound violation while accessing address 0x7fffffffc3b3
1627 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1628 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1630 * Rust language support.
1631 GDB now supports debugging programs written in the Rust programming
1632 language. See https://www.rust-lang.org/ for more information about
1635 * Support for running interpreters on specified input/output devices
1637 GDB now supports a new mechanism that allows frontends to provide
1638 fully featured GDB console views, as a better alternative to
1639 building such views on top of the "-interpreter-exec console"
1640 command. See the new "new-ui" command below. With that command,
1641 frontends can now start GDB in the traditional command-line mode
1642 running in an embedded terminal emulator widget, and create a
1643 separate MI interpreter running on a specified i/o device. In this
1644 way, GDB handles line editing, history, tab completion, etc. in the
1645 console all by itself, and the GUI uses the separate MI interpreter
1646 for its own control and synchronization, invisible to the command
1649 * The "catch syscall" command catches groups of related syscalls.
1651 The "catch syscall" command now supports catching a group of related
1652 syscalls using the 'group:' or 'g:' prefix.
1657 skip -gfile file-glob-pattern
1658 skip -function function
1659 skip -rfunction regular-expression
1660 A generalized form of the skip command, with new support for
1661 glob-style file names and regular expressions for function names.
1662 Additionally, a file spec and a function spec may now be combined.
1664 maint info line-table REGEXP
1665 Display the contents of GDB's internal line table data structure.
1668 Run any GDB unit tests that were compiled in.
1671 Start a new user interface instance running INTERP as interpreter,
1672 using the TTY file for input/output.
1676 ** gdb.Breakpoint objects have a new attribute "pending", which
1677 indicates whether the breakpoint is pending.
1678 ** Three new breakpoint-related events have been added:
1679 gdb.breakpoint_created, gdb.breakpoint_modified, and
1680 gdb.breakpoint_deleted.
1682 signal-event EVENTID
1683 Signal ("set") the given MS-Windows event object. This is used in
1684 conjunction with the Windows JIT debugging (AeDebug) support, where
1685 the OS suspends a crashing process until a debugger can attach to
1686 it. Resuming the crashing process, in order to debug it, is done by
1687 signalling an event.
1689 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1690 was added in GDBserver, including JIT compiling fast tracepoint's
1691 conditional expression bytecode into native code.
1693 * Support for various remote target protocols and ROM monitors has
1696 target m32rsdi Remote M32R debugging over SDI
1697 target mips MIPS remote debugging protocol
1698 target pmon PMON ROM monitor
1699 target ddb NEC's DDB variant of PMON for Vr4300
1700 target rockhopper NEC RockHopper variant of PMON
1701 target lsi LSI variant of PMO
1703 * Support for tracepoints and fast tracepoints on powerpc-linux,
1704 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1705 including JIT compiling fast tracepoint's conditional expression
1706 bytecode into native code.
1708 * MI async record =record-started now includes the method and format used for
1709 recording. For example:
1711 =record-started,thread-group="i1",method="btrace",format="bts"
1713 * MI async record =thread-selected now includes the frame field. For example:
1715 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1719 Andes NDS32 nds32*-*-elf
1721 *** Changes in GDB 7.11
1723 * GDB now supports debugging kernel-based threads on FreeBSD.
1725 * Per-inferior thread numbers
1727 Thread numbers are now per inferior instead of global. If you're
1728 debugging multiple inferiors, GDB displays thread IDs using a
1729 qualified INF_NUM.THR_NUM form. For example:
1733 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1734 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1735 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1736 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1738 As consequence, thread numbers as visible in the $_thread
1739 convenience variable and in Python's InferiorThread.num attribute
1740 are no longer unique between inferiors.
1742 GDB now maintains a second thread ID per thread, referred to as the
1743 global thread ID, which is the new equivalent of thread numbers in
1744 previous releases. See also $_gthread below.
1746 For backwards compatibility, MI's thread IDs always refer to global
1749 * Commands that accept thread IDs now accept the qualified
1750 INF_NUM.THR_NUM form as well. For example:
1753 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1756 * In commands that accept a list of thread IDs, you can now refer to
1757 all threads of an inferior using a star wildcard. GDB accepts
1758 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1759 refer to all threads of the current inferior. For example, "info
1762 * You can use "info threads -gid" to display the global thread ID of
1765 * The new convenience variable $_gthread holds the global number of
1768 * The new convenience variable $_inferior holds the number of the
1771 * GDB now displays the ID and name of the thread that hit a breakpoint
1772 or received a signal, if your program is multi-threaded. For
1775 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1776 Thread 1 "main" received signal SIGINT, Interrupt.
1778 * Record btrace now supports non-stop mode.
1780 * Support for tracepoints on aarch64-linux was added in GDBserver.
1782 * The 'record instruction-history' command now indicates speculative execution
1783 when using the Intel Processor Trace recording format.
1785 * GDB now allows users to specify explicit locations, bypassing
1786 the linespec parser. This feature is also available to GDB/MI
1789 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1790 GDB now is able to debug both AArch64 applications and ARM applications
1793 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1794 including JIT compiling fast tracepoint's conditional expression bytecode
1797 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1799 * "info threads", "info inferiors", "info display", "info checkpoints"
1800 and "maint info program-spaces" now list the corresponding items in
1801 ascending ID order, for consistency with all other "info" commands.
1803 * In Ada, the overloads selection menu has been enhanced to display the
1804 parameter types and the return types for the matching overloaded subprograms.
1808 maint set target-non-stop (on|off|auto)
1809 maint show target-non-stop
1810 Control whether GDB targets always operate in non-stop mode even if
1811 "set non-stop" is "off". The default is "auto", meaning non-stop
1812 mode is enabled if supported by the target.
1814 maint set bfd-sharing
1815 maint show bfd-sharing
1816 Control the reuse of bfd objects.
1819 show debug bfd-cache
1820 Control display of debugging info regarding bfd caching.
1824 Control display of debugging info regarding FreeBSD threads.
1826 set remote multiprocess-extensions-packet
1827 show remote multiprocess-extensions-packet
1828 Set/show the use of the remote protocol multiprocess extensions.
1830 set remote thread-events
1831 show remote thread-events
1832 Set/show the use of thread create/exit events.
1834 set ada print-signatures on|off
1835 show ada print-signatures"
1836 Control whether parameter types and return types are displayed in overloads
1837 selection menus. It is activated (@code{on}) by default.
1841 Controls the maximum size of memory, in bytes, that GDB will
1842 allocate for value contents. Prevents incorrect programs from
1843 causing GDB to allocate overly large buffers. Default is 64k.
1845 * The "disassemble" command accepts a new modifier: /s.
1846 It prints mixed source+disassembly like /m with two differences:
1847 - disassembled instructions are now printed in program order, and
1848 - and source for all relevant files is now printed.
1849 The "/m" option is now considered deprecated: its "source-centric"
1850 output hasn't proved useful in practice.
1852 * The "record instruction-history" command accepts a new modifier: /s.
1853 It behaves exactly like /m and prints mixed source+disassembly.
1855 * The "set scheduler-locking" command supports a new mode "replay".
1856 It behaves like "off" in record mode and like "on" in replay mode.
1858 * Support for various ROM monitors has been removed:
1860 target dbug dBUG ROM monitor for Motorola ColdFire
1861 target picobug Motorola picobug monitor
1862 target dink32 DINK32 ROM monitor for PowerPC
1863 target m32r Renesas M32R/D ROM monitor
1864 target mon2000 mon2000 ROM monitor
1865 target ppcbug PPCBUG ROM monitor for PowerPC
1867 * Support for reading/writing memory and extracting values on architectures
1868 whose memory is addressable in units of any integral multiple of 8 bits.
1871 Allows to break when an Ada exception is handled.
1873 * New remote packets
1876 Indicates that an exec system call was executed.
1878 exec-events feature in qSupported
1879 The qSupported packet allows GDB to request support for exec
1880 events using the new 'gdbfeature' exec-event, and the qSupported
1881 response can contain the corresponding 'stubfeature'. Set and
1882 show commands can be used to display whether these features are enabled.
1885 Equivalent to interrupting with the ^C character, but works in
1888 thread created stop reason (T05 create:...)
1889 Indicates that the thread was just created and is stopped at entry.
1891 thread exit stop reply (w exitcode;tid)
1892 Indicates that the thread has terminated.
1895 Enables/disables thread create and exit event reporting. For
1896 example, this is used in non-stop mode when GDB stops a set of
1897 threads and synchronously waits for the their corresponding stop
1898 replies. Without exit events, if one of the threads exits, GDB
1899 would hang forever not knowing that it should no longer expect a
1900 stop for that same thread.
1903 Indicates that there are no resumed threads left in the target (all
1904 threads are stopped). The remote stub reports support for this stop
1905 reply to GDB's qSupported query.
1908 Enables/disables catching syscalls from the inferior process.
1909 The remote stub reports support for this packet to GDB's qSupported query.
1911 syscall_entry stop reason
1912 Indicates that a syscall was just called.
1914 syscall_return stop reason
1915 Indicates that a syscall just returned.
1917 * Extended-remote exec events
1919 ** GDB now has support for exec events on extended-remote Linux targets.
1920 For such targets with Linux kernels 2.5.46 and later, this enables
1921 follow-exec-mode and exec catchpoints.
1923 set remote exec-event-feature-packet
1924 show remote exec-event-feature-packet
1925 Set/show the use of the remote exec event feature.
1927 * Thread names in remote protocol
1929 The reply to qXfer:threads:read may now include a name attribute for each
1932 * Target remote mode fork and exec events
1934 ** GDB now has support for fork and exec events on target remote mode
1935 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1936 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1937 fork and exec catchpoints.
1939 * Remote syscall events
1941 ** GDB now has support for catch syscall on remote Linux targets,
1942 currently enabled on x86/x86_64 architectures.
1944 set remote catch-syscall-packet
1945 show remote catch-syscall-packet
1946 Set/show the use of the remote catch syscall feature.
1950 ** The -var-set-format command now accepts the zero-hexadecimal
1951 format. It outputs data in hexadecimal format with zero-padding on the
1956 ** gdb.InferiorThread objects have a new attribute "global_num",
1957 which refers to the thread's global thread ID. The existing
1958 "num" attribute now refers to the thread's per-inferior number.
1959 See "Per-inferior thread numbers" above.
1960 ** gdb.InferiorThread objects have a new attribute "inferior", which
1961 is the Inferior object the thread belongs to.
1963 *** Changes in GDB 7.10
1965 * Support for process record-replay and reverse debugging on aarch64*-linux*
1966 targets has been added. GDB now supports recording of A64 instruction set
1967 including advance SIMD instructions.
1969 * Support for Sun's version of the "stabs" debug file format has been removed.
1971 * GDB now honors the content of the file /proc/PID/coredump_filter
1972 (PID is the process ID) on GNU/Linux systems. This file can be used
1973 to specify the types of memory mappings that will be included in a
1974 corefile. For more information, please refer to the manual page of
1975 "core(5)". GDB also has a new command: "set use-coredump-filter
1976 on|off". It allows to set whether GDB will read the content of the
1977 /proc/PID/coredump_filter file when generating a corefile.
1979 * The "info os" command on GNU/Linux can now display information on
1981 "info os cpus" Listing of all cpus/cores on the system
1983 * GDB has two new commands: "set serial parity odd|even|none" and
1984 "show serial parity". These allows to set or show parity for the
1987 * The "info source" command now displays the producer string if it was
1988 present in the debug info. This typically includes the compiler version
1989 and may include things like its command line arguments.
1991 * The "info dll", an alias of the "info sharedlibrary" command,
1992 is now available on all platforms.
1994 * Directory names supplied to the "set sysroot" commands may be
1995 prefixed with "target:" to tell GDB to access shared libraries from
1996 the target system, be it local or remote. This replaces the prefix
1997 "remote:". The default sysroot has been changed from "" to
1998 "target:". "remote:" is automatically converted to "target:" for
1999 backward compatibility.
2001 * The system root specified by "set sysroot" will be prepended to the
2002 filename of the main executable (if reported to GDB as absolute by
2003 the operating system) when starting processes remotely, and when
2004 attaching to already-running local or remote processes.
2006 * GDB now supports automatic location and retrieval of executable
2007 files from remote targets. Remote debugging can now be initiated
2008 using only a "target remote" or "target extended-remote" command
2009 (no "set sysroot" or "file" commands are required). See "New remote
2012 * The "dump" command now supports verilog hex format.
2014 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2016 * On GNU/Linux, GDB and gdbserver are now able to access executable
2017 and shared library files without a "set sysroot" command when
2018 attaching to processes running in different mount namespaces from
2019 the debugger. This makes it possible to attach to processes in
2020 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2021 See "New remote packets" below.
2023 * The "tui reg" command now provides completion for all of the
2024 available register groups, including target specific groups.
2026 * The HISTSIZE environment variable is no longer read when determining
2027 the size of GDB's command history. GDB now instead reads the dedicated
2028 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2029 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2034 ** Memory ports can now be unbuffered.
2038 ** gdb.Objfile objects have a new attribute "username",
2039 which is the name of the objfile as specified by the user,
2040 without, for example, resolving symlinks.
2041 ** You can now write frame unwinders in Python.
2042 ** gdb.Type objects have a new method "optimized_out",
2043 returning optimized out gdb.Value instance of this type.
2044 ** gdb.Value objects have new methods "reference_value" and
2045 "const_value" which return a reference to the value and a
2046 "const" version of the value respectively.
2050 maint print symbol-cache
2051 Print the contents of the symbol cache.
2053 maint print symbol-cache-statistics
2054 Print statistics of symbol cache usage.
2056 maint flush-symbol-cache
2057 Flush the contents of the symbol cache.
2061 Start branch trace recording using Branch Trace Store (BTS) format.
2064 Evaluate expression by using the compiler and print result.
2068 Explicit commands for enabling and disabling tui mode.
2071 set mpx bound on i386 and amd64
2072 Support for bound table investigation on Intel MPX enabled applications.
2076 Start branch trace recording using Intel Processor Trace format.
2079 Print information about branch tracing internals.
2081 maint btrace packet-history
2082 Print the raw branch tracing data.
2084 maint btrace clear-packet-history
2085 Discard the stored raw branch tracing data.
2088 Discard all branch tracing data. It will be fetched and processed
2089 anew by the next "record" command.
2094 Renamed from "set debug dwarf2-die".
2095 show debug dwarf-die
2096 Renamed from "show debug dwarf2-die".
2098 set debug dwarf-read
2099 Renamed from "set debug dwarf2-read".
2100 show debug dwarf-read
2101 Renamed from "show debug dwarf2-read".
2103 maint set dwarf always-disassemble
2104 Renamed from "maint set dwarf2 always-disassemble".
2105 maint show dwarf always-disassemble
2106 Renamed from "maint show dwarf2 always-disassemble".
2108 maint set dwarf max-cache-age
2109 Renamed from "maint set dwarf2 max-cache-age".
2110 maint show dwarf max-cache-age
2111 Renamed from "maint show dwarf2 max-cache-age".
2113 set debug dwarf-line
2114 show debug dwarf-line
2115 Control display of debugging info regarding DWARF line processing.
2118 show max-completions
2119 Set the maximum number of candidates to be considered during
2120 completion. The default value is 200. This limit allows GDB
2121 to avoid generating large completion lists, the computation of
2122 which can cause the debugger to become temporarily unresponsive.
2124 set history remove-duplicates
2125 show history remove-duplicates
2126 Control the removal of duplicate history entries.
2128 maint set symbol-cache-size
2129 maint show symbol-cache-size
2130 Control the size of the symbol cache.
2132 set|show record btrace bts buffer-size
2133 Set and show the size of the ring buffer used for branch tracing in
2135 The obtained size may differ from the requested size. Use "info
2136 record" to see the obtained buffer size.
2138 set debug linux-namespaces
2139 show debug linux-namespaces
2140 Control display of debugging info regarding Linux namespaces.
2142 set|show record btrace pt buffer-size
2143 Set and show the size of the ring buffer used for branch tracing in
2144 Intel Processor Trace format.
2145 The obtained size may differ from the requested size. Use "info
2146 record" to see the obtained buffer size.
2148 maint set|show btrace pt skip-pad
2149 Set and show whether PAD packets are skipped when computing the
2152 * The command 'thread apply all' can now support new option '-ascending'
2153 to call its specified command for all threads in ascending order.
2155 * Python/Guile scripting
2157 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2158 special section named `.debug_gdb_scripts'.
2160 * New remote packets
2162 qXfer:btrace-conf:read
2163 Return the branch trace configuration for the current thread.
2165 Qbtrace-conf:bts:size
2166 Set the requested ring buffer size for branch tracing in BTS format.
2169 Enable Intel Processor Trace-based branch tracing for the current
2170 process. The remote stub reports support for this packet to GDB's
2173 Qbtrace-conf:pt:size
2174 Set the requested ring buffer size for branch tracing in Intel Processor
2178 Indicates a memory breakpoint instruction was executed, irrespective
2179 of whether it was GDB that planted the breakpoint or the breakpoint
2180 is hardcoded in the program. This is required for correct non-stop
2184 Indicates the target stopped for a hardware breakpoint. This is
2185 required for correct non-stop mode operation.
2188 Return information about files on the remote system.
2190 qXfer:exec-file:read
2191 Return the full absolute name of the file that was executed to
2192 create a process running on the remote system.
2195 Select the filesystem on which vFile: operations with filename
2196 arguments will operate. This is required for GDB to be able to
2197 access files on remote targets where the remote stub does not
2198 share a common filesystem with the inferior(s).
2201 Indicates that a fork system call was executed.
2204 Indicates that a vfork system call was executed.
2206 vforkdone stop reason
2207 Indicates that a vfork child of the specified process has executed
2208 an exec or exit, allowing the vfork parent to resume execution.
2210 fork-events and vfork-events features in qSupported
2211 The qSupported packet allows GDB to request support for fork and
2212 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2213 and the qSupported response can contain the corresponding
2214 'stubfeatures'. Set and show commands can be used to display
2215 whether these features are enabled.
2217 * Extended-remote fork events
2219 ** GDB now has support for fork events on extended-remote Linux
2220 targets. For targets with Linux kernels 2.5.60 and later, this
2221 enables follow-fork-mode and detach-on-fork for both fork and
2222 vfork, as well as fork and vfork catchpoints.
2224 * The info record command now shows the recording format and the
2225 branch tracing configuration for the current thread when using
2226 the btrace record target.
2227 For the BTS format, it shows the ring buffer size.
2229 * GDB now has support for DTrace USDT (Userland Static Defined
2230 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2232 * GDB now supports access to vector registers on S/390 GNU/Linux
2235 * Removed command line options
2237 -xdb HP-UX XDB compatibility mode.
2239 * Removed targets and native configurations
2241 HP/PA running HP-UX hppa*-*-hpux*
2242 Itanium running HP-UX ia64-*-hpux*
2244 * New configure options
2247 This configure option allows the user to build GDB with support for
2248 Intel Processor Trace (default: auto). This requires libipt.
2250 --with-libipt-prefix=PATH
2251 Specify the path to the version of libipt that GDB should use.
2252 $PATH/include should contain the intel-pt.h header and
2253 $PATH/lib should contain the libipt.so library.
2255 *** Changes in GDB 7.9.1
2259 ** Xmethods can now specify a result type.
2261 *** Changes in GDB 7.9
2263 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2267 ** You can now access frame registers from Python scripts.
2268 ** New attribute 'producer' for gdb.Symtab objects.
2269 ** gdb.Objfile objects have a new attribute "progspace",
2270 which is the gdb.Progspace object of the containing program space.
2271 ** gdb.Objfile objects have a new attribute "owner".
2272 ** gdb.Objfile objects have a new attribute "build_id",
2273 which is the build ID generated when the file was built.
2274 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2275 ** A new event "gdb.clear_objfiles" has been added, triggered when
2276 selecting a new file to debug.
2277 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2278 ** New function gdb.lookup_objfile.
2280 New events which are triggered when GDB modifies the state of the
2283 ** gdb.events.inferior_call_pre: Function call is about to be made.
2284 ** gdb.events.inferior_call_post: Function call has just been made.
2285 ** gdb.events.memory_changed: A memory location has been altered.
2286 ** gdb.events.register_changed: A register has been altered.
2288 * New Python-based convenience functions:
2290 ** $_caller_is(name [, number_of_frames])
2291 ** $_caller_matches(regexp [, number_of_frames])
2292 ** $_any_caller_is(name [, number_of_frames])
2293 ** $_any_caller_matches(regexp [, number_of_frames])
2295 * GDB now supports the compilation and injection of source code into
2296 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2297 to compile the source code to object code, and if successful, inject
2298 and execute that code within the current context of the inferior.
2299 Currently the C language is supported. The commands used to
2300 interface with this new feature are:
2302 compile code [-raw|-r] [--] [source code]
2303 compile file [-raw|-r] filename
2307 demangle [-l language] [--] name
2308 Demangle "name" in the specified language, or the current language
2309 if elided. This command is renamed from the "maint demangle" command.
2310 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2311 as "maint demangler-warning".
2313 queue-signal signal-name-or-number
2314 Queue a signal to be delivered to the thread when it is resumed.
2316 add-auto-load-scripts-directory directory
2317 Add entries to the list of directories from which to load auto-loaded
2320 maint print user-registers
2321 List all currently available "user" registers.
2323 compile code [-r|-raw] [--] [source code]
2324 Compile, inject, and execute in the inferior the executable object
2325 code produced by compiling the provided source code.
2327 compile file [-r|-raw] filename
2328 Compile and inject into the inferior the executable object code
2329 produced by compiling the source code stored in the filename
2332 * On resume, GDB now always passes the signal the program had stopped
2333 for to the thread the signal was sent to, even if the user changed
2334 threads before resuming. Previously GDB would often (but not
2335 always) deliver the signal to the thread that happens to be current
2338 * Conversely, the "signal" command now consistently delivers the
2339 requested signal to the current thread. GDB now asks for
2340 confirmation if the program had stopped for a signal and the user
2341 switched threads meanwhile.
2343 * "breakpoint always-inserted" modes "off" and "auto" merged.
2345 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2346 won't remove breakpoints from the target until all threads stop,
2347 even in non-stop mode. The "auto" mode has been removed, and "off"
2348 is now the default mode.
2352 set debug symbol-lookup
2353 show debug symbol-lookup
2354 Control display of debugging info regarding symbol lookup.
2358 ** The -list-thread-groups command outputs an exit-code field for
2359 inferiors that have exited.
2363 MIPS SDE mips*-sde*-elf*
2367 Support for these obsolete configurations has been removed.
2369 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2370 SGI Irix-5.x mips-*-irix5*
2371 SGI Irix-6.x mips-*-irix6*
2372 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2373 VAX running Ultrix vax-*-ultrix*
2375 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2376 and "assf"), have been removed. Use the "sharedlibrary" command, or
2377 its alias "share", instead.
2379 *** Changes in GDB 7.8
2381 * New command line options
2384 This is an alias for the --data-directory option.
2386 * GDB supports printing and modifying of variable length automatic arrays
2387 as specified in ISO C99.
2389 * The ARM simulator now supports instruction level tracing
2390 with or without disassembly.
2394 GDB now has support for scripting using Guile. Whether this is
2395 available is determined at configure time.
2396 Guile version 2.0 or greater is required.
2397 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2399 * New commands (for set/show, see "New options" below)
2403 Invoke CODE by passing it to the Guile interpreter.
2407 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2409 info auto-load guile-scripts [regexp]
2410 Print the list of automatically loaded Guile scripts.
2412 * The source command is now capable of sourcing Guile scripts.
2413 This feature is dependent on the debugger being built with Guile support.
2417 set print symbol-loading (off|brief|full)
2418 show print symbol-loading
2419 Control whether to print informational messages when loading symbol
2420 information for a file. The default is "full", but when debugging
2421 programs with large numbers of shared libraries the amount of output
2422 becomes less useful.
2424 set guile print-stack (none|message|full)
2425 show guile print-stack
2426 Show a stack trace when an error is encountered in a Guile script.
2428 set auto-load guile-scripts (on|off)
2429 show auto-load guile-scripts
2430 Control auto-loading of Guile script files.
2432 maint ada set ignore-descriptive-types (on|off)
2433 maint ada show ignore-descriptive-types
2434 Control whether the debugger should ignore descriptive types in Ada
2435 programs. The default is not to ignore the descriptive types. See
2436 the user manual for more details on descriptive types and the intended
2437 usage of this option.
2439 set auto-connect-native-target
2441 Control whether GDB is allowed to automatically connect to the
2442 native target for the run, attach, etc. commands when not connected
2443 to any target yet. See also "target native" below.
2445 set record btrace replay-memory-access (read-only|read-write)
2446 show record btrace replay-memory-access
2447 Control what memory accesses are allowed during replay.
2449 maint set target-async (on|off)
2450 maint show target-async
2451 This controls whether GDB targets operate in synchronous or
2452 asynchronous mode. Normally the default is asynchronous, if it is
2453 available; but this can be changed to more easily debug problems
2454 occurring only in synchronous mode.
2456 set mi-async (on|off)
2458 Control whether MI asynchronous mode is preferred. This supersedes
2459 "set target-async" of previous GDB versions.
2461 * "set target-async" is deprecated as a CLI option and is now an alias
2462 for "set mi-async" (only puts MI into async mode).
2464 * Background execution commands (e.g., "c&", "s&", etc.) are now
2465 possible ``out of the box'' if the target supports them. Previously
2466 the user would need to explicitly enable the possibility with the
2467 "set target-async on" command.
2469 * New features in the GDB remote stub, GDBserver
2471 ** New option --debug-format=option1[,option2,...] allows one to add
2472 additional text to each output. At present only timestamps
2473 are supported: --debug-format=timestamps.
2474 Timestamps can also be turned on with the
2475 "monitor set debug-format timestamps" command from GDB.
2477 * The 'record instruction-history' command now starts counting instructions
2478 at one. This also affects the instruction ranges reported by the
2479 'record function-call-history' command when given the /i modifier.
2481 * The command 'record function-call-history' supports a new modifier '/c' to
2482 indent the function names based on their call stack depth.
2483 The fields for the '/i' and '/l' modifier have been reordered.
2484 The source line range is now prefixed with 'at'.
2485 The instruction range is now prefixed with 'inst'.
2486 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2487 "record instruction-history" and "list" commands.
2489 * The ranges given as arguments to the 'record function-call-history' and
2490 'record instruction-history' commands are now inclusive.
2492 * The btrace record target now supports the 'record goto' command.
2493 For locations inside the execution trace, the back trace is computed
2494 based on the information stored in the execution trace.
2496 * The btrace record target supports limited reverse execution and replay.
2497 The target does not record data and therefore does not allow reading
2498 memory or registers.
2500 * The "catch syscall" command now works on s390*-linux* targets.
2502 * The "compare-sections" command is no longer specific to target
2503 remote. It now works with all targets.
2505 * All native targets are now consistently called "native".
2506 Consequently, the "target child", "target GNU", "target djgpp",
2507 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2508 commands have been replaced with "target native". The QNX/NTO port
2509 leaves the "procfs" target in place and adds a "native" target for
2510 consistency with other ports. The impact on users should be minimal
2511 as these commands previously either throwed an error, or were
2512 no-ops. The target's name is visible in the output of the following
2513 commands: "help target", "info target", "info files", "maint print
2516 * The "target native" command now connects to the native target. This
2517 can be used to launch native programs even when "set
2518 auto-connect-native-target" is set to off.
2520 * GDB now supports access to Intel MPX registers on GNU/Linux.
2522 * Support for Intel AVX-512 registers on GNU/Linux.
2523 Support displaying and modifying Intel AVX-512 registers
2524 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2526 * New remote packets
2528 qXfer:btrace:read's annex
2529 The qXfer:btrace:read packet supports a new annex 'delta' to read
2530 branch trace incrementally.
2534 ** Valid Python operations on gdb.Value objects representing
2535 structs/classes invoke the corresponding overloaded operators if
2537 ** New `Xmethods' feature in the Python API. Xmethods are
2538 additional methods or replacements for existing methods of a C++
2539 class. This feature is useful for those cases where a method
2540 defined in C++ source code could be inlined or optimized out by
2541 the compiler, making it unavailable to GDB.
2544 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2546 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2547 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2548 its alias "share", instead.
2550 * The commands "set remotebaud" and "show remotebaud" are no longer
2551 supported. Use "set serial baud" and "show serial baud" (respectively)
2556 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2557 target-async". The latter is left as a deprecated alias of the
2558 former for backward compatibility. If the target supports it,
2559 CLI background execution commands are now always possible by
2560 default, independently of whether the frontend stated a
2561 preference for asynchronous execution with "-gdb-set mi-async".
2562 Previously "-gdb-set target-async off" affected both MI execution
2563 commands and CLI execution commands.
2565 *** Changes in GDB 7.7
2567 * Improved support for process record-replay and reverse debugging on
2568 arm*-linux* targets. Support for thumb32 and syscall instruction
2569 recording has been added.
2571 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2573 * GDB now supports Fission DWP file format version 2.
2574 http://gcc.gnu.org/wiki/DebugFission
2576 * New convenience function "$_isvoid", to check whether an expression
2577 is void. A void expression is an expression where the type of the
2578 result is "void". For example, some convenience variables may be
2579 "void" when evaluated (e.g., "$_exitcode" before the execution of
2580 the program being debugged; or an undefined convenience variable).
2581 Another example, when calling a function whose return type is
2584 * The "maintenance print objfiles" command now takes an optional regexp.
2586 * The "catch syscall" command now works on arm*-linux* targets.
2588 * GDB now consistently shows "<not saved>" when printing values of
2589 registers the debug info indicates have not been saved in the frame
2590 and there's nowhere to retrieve them from
2591 (callee-saved/call-clobbered registers):
2596 (gdb) info registers rax
2599 Before, the former would print "<optimized out>", and the latter
2600 "*value not available*".
2602 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2607 ** Frame filters and frame decorators have been added.
2608 ** Temporary breakpoints are now supported.
2609 ** Line tables representation has been added.
2610 ** New attribute 'parent_type' for gdb.Field objects.
2611 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2612 ** New attribute 'name' for gdb.Type objects.
2616 Nios II ELF nios2*-*-elf
2617 Nios II GNU/Linux nios2*-*-linux
2618 Texas Instruments MSP430 msp430*-*-elf
2620 * Removed native configurations
2622 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2623 been removed. ELF variants of these configurations are kept supported.
2625 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2626 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2627 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2628 i[34567]86-*-openbsd3.[0-3]
2629 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2630 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2631 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2635 Like "catch throw", but catches a re-thrown exception.
2636 maint check-psymtabs
2637 Renamed from old "maint check-symtabs".
2639 Perform consistency checks on symtabs.
2640 maint expand-symtabs
2641 Expand symtabs matching an optional regexp.
2644 Display the details of GDB configure-time options.
2646 maint set|show per-command
2647 maint set|show per-command space
2648 maint set|show per-command time
2649 maint set|show per-command symtab
2650 Enable display of per-command gdb resource usage.
2652 remove-symbol-file FILENAME
2653 remove-symbol-file -a ADDRESS
2654 Remove a symbol file added via add-symbol-file. The file to remove
2655 can be identified by its filename or by an address that lies within
2656 the boundaries of this symbol file in memory.
2659 info exceptions REGEXP
2660 Display the list of Ada exceptions defined in the program being
2661 debugged. If provided, only the exceptions whose names match REGEXP
2666 set debug symfile off|on
2668 Control display of debugging info regarding reading symbol files and
2669 symbol tables within those files
2671 set print raw frame-arguments
2672 show print raw frame-arguments
2673 Set/show whether to print frame arguments in raw mode,
2674 disregarding any defined pretty-printers.
2676 set remote trace-status-packet
2677 show remote trace-status-packet
2678 Set/show the use of remote protocol qTStatus packet.
2682 Control display of debugging messages related to Nios II targets.
2686 Control whether target-assisted range stepping is enabled.
2688 set startup-with-shell
2689 show startup-with-shell
2690 Specifies whether Unix child processes are started via a shell or
2695 Use the target memory cache for accesses to the code segment. This
2696 improves performance of remote debugging (particularly disassembly).
2698 * You can now use a literal value 'unlimited' for options that
2699 interpret 0 or -1 as meaning "unlimited". E.g., "set
2700 trace-buffer-size unlimited" is now an alias for "set
2701 trace-buffer-size -1" and "set height unlimited" is now an alias for
2704 * The "set debug symtab-create" debugging option of GDB has been changed to
2705 accept a verbosity level. 0 means "off", 1 provides basic debugging
2706 output, and values of 2 or greater provides more verbose output.
2708 * New command-line options
2710 Display the details of GDB configure-time options.
2712 * The command 'tsave' can now support new option '-ctf' to save trace
2713 buffer in Common Trace Format.
2715 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2718 * GDB now implements the C++ 'typeid' operator.
2720 * The new convenience variable $_exception holds the exception being
2721 thrown or caught at an exception-related catchpoint.
2723 * The exception-related catchpoints, like "catch throw", now accept a
2724 regular expression which can be used to filter exceptions by type.
2726 * The new convenience variable $_exitsignal is automatically set to
2727 the terminating signal number when the program being debugged dies
2728 due to an uncaught signal.
2732 ** All MI commands now accept an optional "--language" option.
2733 Support for this feature can be verified by using the "-list-features"
2734 command, which should contain "language-option".
2736 ** The new command -info-gdb-mi-command allows the user to determine
2737 whether a GDB/MI command is supported or not.
2739 ** The "^error" result record returned when trying to execute an undefined
2740 GDB/MI command now provides a variable named "code" whose content is the
2741 "undefined-command" error code. Support for this feature can be verified
2742 by using the "-list-features" command, which should contain
2743 "undefined-command-error-code".
2745 ** The -trace-save MI command can optionally save trace buffer in Common
2748 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2750 ** The command -data-list-register-values now accepts an optional
2751 "--skip-unavailable" option. When used, only the available registers
2754 ** The new command -trace-frame-collected dumps collected variables,
2755 computed expressions, tvars, memory and registers in a traceframe.
2757 ** The commands -stack-list-locals, -stack-list-arguments and
2758 -stack-list-variables now accept an option "--skip-unavailable".
2759 When used, only the available locals or arguments are displayed.
2761 ** The -exec-run command now accepts an optional "--start" option.
2762 When used, the command follows the same semantics as the "start"
2763 command, stopping the program's execution at the start of its
2764 main subprogram. Support for this feature can be verified using
2765 the "-list-features" command, which should contain
2766 "exec-run-start-option".
2768 ** The new commands -catch-assert and -catch-exceptions insert
2769 catchpoints stopping the program when Ada exceptions are raised.
2771 ** The new command -info-ada-exceptions provides the equivalent of
2772 the new "info exceptions" command.
2774 * New system-wide configuration scripts
2775 A GDB installation now provides scripts suitable for use as system-wide
2776 configuration scripts for the following systems:
2780 * GDB now supports target-assigned range stepping with remote targets.
2781 This improves the performance of stepping source lines by reducing
2782 the number of control packets from/to GDB. See "New remote packets"
2785 * GDB now understands the element 'tvar' in the XML traceframe info.
2786 It has the id of the collected trace state variables.
2788 * On S/390 targets that provide the transactional-execution feature,
2789 the program interruption transaction diagnostic block (TDB) is now
2790 represented as a number of additional "registers" in GDB.
2792 * New remote packets
2796 The vCont packet supports a new 'r' action, that tells the remote
2797 stub to step through an address range itself, without GDB
2798 involvemement at each single-step.
2800 qXfer:libraries-svr4:read's annex
2801 The previously unused annex of the qXfer:libraries-svr4:read packet
2802 is now used to support passing an argument list. The remote stub
2803 reports support for this argument list to GDB's qSupported query.
2804 The defined arguments are "start" and "prev", used to reduce work
2805 necessary for library list updating, resulting in significant
2808 * New features in the GDB remote stub, GDBserver
2810 ** GDBserver now supports target-assisted range stepping. Currently
2811 enabled on x86/x86_64 GNU/Linux targets.
2813 ** GDBserver now adds element 'tvar' in the XML in the reply to
2814 'qXfer:traceframe-info:read'. It has the id of the collected
2815 trace state variables.
2817 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2820 * New 'z' formatter for printing and examining memory, this displays the
2821 value as hexadecimal zero padded on the left to the size of the type.
2823 * GDB can now use Windows x64 unwinding data.
2825 * The "set remotebaud" command has been replaced by "set serial baud".
2826 Similarly, "show remotebaud" has been replaced by "show serial baud".
2827 The "set remotebaud" and "show remotebaud" commands are still available
2828 to provide backward compatibility with older versions of GDB.
2830 *** Changes in GDB 7.6
2832 * Target record has been renamed to record-full.
2833 Record/replay is now enabled with the "record full" command.
2834 This also affects settings that are associated with full record/replay
2835 that have been moved from "set/show record" to "set/show record full":
2837 set|show record full insn-number-max
2838 set|show record full stop-at-limit
2839 set|show record full memory-query
2841 * A new record target "record-btrace" has been added. The new target
2842 uses hardware support to record the control-flow of a process. It
2843 does not support replaying the execution, but it implements the
2844 below new commands for investigating the recorded execution log.
2845 This new recording method can be enabled using:
2849 The "record-btrace" target is only available on Intel Atom processors
2850 and requires a Linux kernel 2.6.32 or later.
2852 * Two new commands have been added for record/replay to give information
2853 about the recorded execution without having to replay the execution.
2854 The commands are only supported by "record btrace".
2856 record instruction-history prints the execution history at
2857 instruction granularity
2859 record function-call-history prints the execution history at
2860 function granularity
2862 * New native configurations
2864 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2865 FreeBSD/powerpc powerpc*-*-freebsd
2866 x86_64/Cygwin x86_64-*-cygwin*
2867 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2871 ARM AArch64 aarch64*-*-elf
2872 ARM AArch64 GNU/Linux aarch64*-*-linux
2873 Lynx 178 PowerPC powerpc-*-lynx*178
2874 x86_64/Cygwin x86_64-*-cygwin*
2875 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2877 * If the configured location of system.gdbinit file (as given by the
2878 --with-system-gdbinit option at configure time) is in the
2879 data-directory (as specified by --with-gdb-datadir at configure
2880 time) or in one of its subdirectories, then GDB will look for the
2881 system-wide init file in the directory specified by the
2882 --data-directory command-line option.
2884 * New command line options:
2886 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2887 other initialization files, unlike -nx which disables all of them.
2889 * Removed command line options
2891 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2894 * The 'ptype' and 'whatis' commands now accept an argument to control
2897 * 'info proc' now works on some core files.
2901 ** Vectors can be created with gdb.Type.vector.
2903 ** Python's atexit.register now works in GDB.
2905 ** Types can be pretty-printed via a Python API.
2907 ** Python 3 is now supported (in addition to Python 2.4 or later)
2909 ** New class gdb.Architecture exposes GDB's internal representation
2910 of architecture in the Python API.
2912 ** New method Frame.architecture returns the gdb.Architecture object
2913 corresponding to the frame's architecture.
2915 * New Python-based convenience functions:
2917 ** $_memeq(buf1, buf2, length)
2918 ** $_streq(str1, str2)
2920 ** $_regex(str, regex)
2922 * The 'cd' command now defaults to using '~' (the home directory) if not
2925 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2926 default for GCC since November 2000.
2928 * The command 'forward-search' can now be abbreviated as 'fo'.
2930 * The command 'info tracepoints' can now display 'installed on target'
2931 or 'not installed on target' for each non-pending location of tracepoint.
2933 * New configure options
2935 --enable-libmcheck/--disable-libmcheck
2936 By default, development versions are built with -lmcheck on hosts
2937 that support it, in order to help track memory corruption issues.
2938 Release versions, on the other hand, are built without -lmcheck
2939 by default. The --enable-libmcheck/--disable-libmcheck configure
2940 options allow the user to override that default.
2941 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2942 This configure option allows the user to build GDB with
2943 libbabeltrace using which GDB can read Common Trace Format data.
2945 * New commands (for set/show, see "New options" below)
2948 Catch signals. This is similar to "handle", but allows commands and
2949 conditions to be attached.
2952 List the BFDs known to GDB.
2954 python-interactive [command]
2956 Start a Python interactive prompt, or evaluate the optional command
2957 and print the result of expressions.
2960 "py" is a new alias for "python".
2962 enable type-printer [name]...
2963 disable type-printer [name]...
2964 Enable or disable type printers.
2968 ** For the Renesas Super-H architecture, the "regs" command has been removed
2969 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2974 set print type methods (on|off)
2975 show print type methods
2976 Control whether method declarations are displayed by "ptype".
2977 The default is to show them.
2979 set print type typedefs (on|off)
2980 show print type typedefs
2981 Control whether typedef definitions are displayed by "ptype".
2982 The default is to show them.
2984 set filename-display basename|relative|absolute
2985 show filename-display
2986 Control the way in which filenames is displayed.
2987 The default is "relative", which preserves previous behavior.
2989 set trace-buffer-size
2990 show trace-buffer-size
2991 Request target to change the size of trace buffer.
2993 set remote trace-buffer-size-packet auto|on|off
2994 show remote trace-buffer-size-packet
2995 Control the use of the remote protocol `QTBuffer:size' packet.
2999 Control display of debugging messages related to ARM AArch64.
3002 set debug coff-pe-read
3003 show debug coff-pe-read
3004 Control display of debugging messages related to reading of COFF/PE
3009 Control display of debugging messages related to Mach-O symbols
3012 set debug notification
3013 show debug notification
3014 Control display of debugging info for async remote notification.
3018 ** Command parameter changes are now notified using new async record
3019 "=cmd-param-changed".
3020 ** Trace frame changes caused by command "tfind" are now notified using
3021 new async record "=traceframe-changed".
3022 ** The creation, deletion and modification of trace state variables
3023 are now notified using new async records "=tsv-created",
3024 "=tsv-deleted" and "=tsv-modified".
3025 ** The start and stop of process record are now notified using new
3026 async record "=record-started" and "=record-stopped".
3027 ** Memory changes are now notified using new async record
3029 ** The data-disassemble command response will include a "fullname" field
3030 containing the absolute file name when source has been requested.
3031 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3032 command, to allow pattern filling of memory areas.
3033 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3034 library load/unload events.
3035 ** The response to breakpoint commands and breakpoint async records
3036 includes an "installed" field containing a boolean state about each
3037 non-pending tracepoint location is whether installed on target or not.
3038 ** Output of the "-trace-status" command includes a "trace-file" field
3039 containing the name of the trace file being examined. This field is
3040 optional, and only present when examining a trace file.
3041 ** The "fullname" field is now always present along with the "file" field,
3042 even if the file cannot be found by GDB.
3044 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3045 You must have the LZMA library available when configuring GDB for this
3046 feature to be enabled. For more information, see:
3047 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3049 * New remote packets
3052 Set the size of trace buffer. The remote stub reports support for this
3053 packet to gdb's qSupported query.
3056 Enable Branch Trace Store (BTS)-based branch tracing for the current
3057 thread. The remote stub reports support for this packet to gdb's
3061 Disable branch tracing for the current thread. The remote stub reports
3062 support for this packet to gdb's qSupported query.
3065 Read the traced branches for the current thread. The remote stub
3066 reports support for this packet to gdb's qSupported query.
3068 *** Changes in GDB 7.5
3070 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3071 for more x32 ABI info.
3073 * GDB now supports access to MIPS DSP registers on Linux targets.
3075 * GDB now supports debugging microMIPS binaries.
3077 * The "info os" command on GNU/Linux can now display information on
3078 several new classes of objects managed by the operating system:
3079 "info os procgroups" lists process groups
3080 "info os files" lists file descriptors
3081 "info os sockets" lists internet-domain sockets
3082 "info os shm" lists shared-memory regions
3083 "info os semaphores" lists semaphores
3084 "info os msg" lists message queues
3085 "info os modules" lists loaded kernel modules
3087 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3088 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3089 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3090 options and inspect the probe arguments using the new $_probe_arg family
3091 of convenience variables. You can obtain more information about SystemTap
3092 in <http://sourceware.org/systemtap/>.
3094 * GDB now supports reversible debugging on ARM, it allows you to
3095 debug basic ARM and THUMB instructions, and provides
3096 record/replay support.
3098 * The option "symbol-reloading" has been deleted as it is no longer used.
3102 ** GDB commands implemented in Python can now be put in command class
3105 ** The "maint set python print-stack on|off" is now deleted.
3107 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3108 apply "flag enum"-style pretty-printing to any enum.
3110 ** gdb.lookup_symbol can now work when there is no current frame.
3112 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3113 the source at which the symbol was defined.
3115 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3116 method 'value'. The former indicates whether the symbol needs a
3117 frame in order to compute its value, and the latter computes the
3120 ** A new method 'referenced_value' on gdb.Value objects which can
3121 dereference pointer as well as C++ reference values.
3123 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3124 which return the global and static blocks (as gdb.Block objects),
3125 of the underlying symbol table, respectively.
3127 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3128 object associated with a PC value.
3130 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3131 of the address range occupied by code for the current source line.
3133 * Go language support.
3134 GDB now supports debugging programs written in the Go programming
3137 * GDBserver now supports stdio connections.
3138 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3140 * The binary "gdbtui" can no longer be built or installed.
3141 Use "gdb -tui" instead.
3143 * GDB will now print "flag" enums specially. A flag enum is one where
3144 all the enumerator values have no bits in common when pairwise
3145 "and"ed. When printing a value whose type is a flag enum, GDB will
3146 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3147 (gdb) print (enum E) 3
3150 * The filename part of a linespec will now match trailing components
3151 of a source file name. For example, "break gcc/expr.c:1000" will
3152 now set a breakpoint in build/gcc/expr.c, but not
3153 build/libcpp/expr.c.
3155 * The "info proc" and "generate-core-file" commands will now also
3156 work on remote targets connected to GDBserver on Linux.
3158 * The command "info catch" has been removed. It has been disabled
3159 since December 2007.
3161 * The "catch exception" and "catch assert" commands now accept
3162 a condition at the end of the command, much like the "break"
3163 command does. For instance:
3165 (gdb) catch exception Constraint_Error if Barrier = True
3167 Previously, it was possible to add a condition to such catchpoints,
3168 but it had to be done as a second step, after the catchpoint had been
3169 created, using the "condition" command.
3171 * The "info static-tracepoint-marker" command will now also work on
3172 native Linux targets with in-process agent.
3174 * GDB can now set breakpoints on inlined functions.
3176 * The .gdb_index section has been updated to include symbols for
3177 inlined functions. GDB will ignore older .gdb_index sections by
3178 default, which could cause symbol files to be loaded more slowly
3179 until their .gdb_index sections can be recreated. The new command
3180 "set use-deprecated-index-sections on" will cause GDB to use any older
3181 .gdb_index sections it finds. This will restore performance, but the
3182 ability to set breakpoints on inlined functions will be lost in symbol
3183 files with older .gdb_index sections.
3185 The .gdb_index section has also been updated to record more information
3186 about each symbol. This speeds up the "info variables", "info functions"
3187 and "info types" commands when used with programs having the .gdb_index
3188 section, as well as speeding up debugging with shared libraries using
3189 the .gdb_index section.
3191 * Ada support for GDB/MI Variable Objects has been added.
3193 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3198 ** New command -info-os is the MI equivalent of "info os".
3200 ** Output logs ("set logging" and related) now include MI output.
3204 ** "set use-deprecated-index-sections on|off"
3205 "show use-deprecated-index-sections on|off"
3206 Controls the use of deprecated .gdb_index sections.
3208 ** "catch load" and "catch unload" can be used to stop when a shared
3209 library is loaded or unloaded, respectively.
3211 ** "enable count" can be used to auto-disable a breakpoint after
3214 ** "info vtbl" can be used to show the virtual method tables for
3215 C++ and Java objects.
3217 ** "explore" and its sub commands "explore value" and "explore type"
3218 can be used to recursively explore values and types of
3219 expressions. These commands are available only if GDB is
3220 configured with '--with-python'.
3222 ** "info auto-load" shows status of all kinds of auto-loaded files,
3223 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3224 sequences of commands files, "info auto-load python-scripts"
3225 shows status of auto-loading Python script files,
3226 "info auto-load local-gdbinit" shows status of loading init file
3227 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3228 status of inferior specific thread debugging shared library loading.
3230 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3231 and "show auto-load-scripts" commands have been deprecated, use their
3232 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3233 and "show auto-load python-scripts" counterparts instead.
3235 ** "dprintf location,format,args..." creates a dynamic printf, which
3236 is basically a breakpoint that does a printf and immediately
3237 resumes your program's execution, so it is like a printf that you
3238 can insert dynamically at runtime instead of at compiletime.
3240 ** "set print symbol"
3242 Controls whether GDB attempts to display the symbol, if any,
3243 corresponding to addresses it prints. This defaults to "on", but
3244 you can set it to "off" to restore GDB's previous behavior.
3246 * Deprecated commands
3248 ** For the Renesas Super-H architecture, the "regs" command has been
3249 deprecated, and "info all-registers" should be used instead.
3253 Renesas RL78 rl78-*-elf
3254 HP OpenVMS ia64 ia64-hp-openvms*
3256 * GDBserver supports evaluation of breakpoint conditions. When
3257 support is advertised by GDBserver, GDB may be told to send the
3258 breakpoint conditions in bytecode form to GDBserver. GDBserver
3259 will only report the breakpoint trigger to GDB when its condition
3264 set mips compression
3265 show mips compression
3266 Select the compressed ISA encoding used in functions that have no symbol
3267 information available. The encoding can be set to either of:
3270 and is updated automatically from ELF file flags if available.
3272 set breakpoint condition-evaluation
3273 show breakpoint condition-evaluation
3274 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3275 GDBserver ("target"). Default option "auto" chooses the most efficient
3277 This option can improve debugger efficiency depending on the speed of the
3281 Disable auto-loading globally.
3284 Show auto-loading setting of all kinds of auto-loaded files.
3286 set auto-load gdb-scripts on|off
3287 show auto-load gdb-scripts
3288 Control auto-loading of GDB canned sequences of commands files.
3290 set auto-load python-scripts on|off
3291 show auto-load python-scripts
3292 Control auto-loading of Python script files.
3294 set auto-load local-gdbinit on|off
3295 show auto-load local-gdbinit
3296 Control loading of init file (.gdbinit) from current directory.
3298 set auto-load libthread-db on|off
3299 show auto-load libthread-db
3300 Control auto-loading of inferior specific thread debugging shared library.
3302 set auto-load scripts-directory <dir1>[:<dir2>...]
3303 show auto-load scripts-directory
3304 Set a list of directories from which to load auto-loaded scripts.
3305 Automatically loaded Python scripts and GDB scripts are located in one
3306 of the directories listed by this option.
3307 The delimiter (':' above) may differ according to the host platform.
3309 set auto-load safe-path <dir1>[:<dir2>...]
3310 show auto-load safe-path
3311 Set a list of directories from which it is safe to auto-load files.
3312 The delimiter (':' above) may differ according to the host platform.
3314 set debug auto-load on|off
3315 show debug auto-load
3316 Control display of debugging info for auto-loading the files above.
3318 set dprintf-style gdb|call|agent
3320 Control the way in which a dynamic printf is performed; "gdb"
3321 requests a GDB printf command, while "call" causes dprintf to call a
3322 function in the inferior. "agent" requests that the target agent
3323 (such as GDBserver) do the printing.
3325 set dprintf-function <expr>
3326 show dprintf-function
3327 set dprintf-channel <expr>
3328 show dprintf-channel
3329 Set the function and optional first argument to the call when using
3330 the "call" style of dynamic printf.
3332 set disconnected-dprintf on|off
3333 show disconnected-dprintf
3334 Control whether agent-style dynamic printfs continue to be in effect
3335 after GDB disconnects.
3337 * New configure options
3339 --with-auto-load-dir
3340 Configure default value for the 'set auto-load scripts-directory'
3341 setting above. It defaults to '$debugdir:$datadir/auto-load',
3342 $debugdir representing global debugging info directories (available
3343 via 'show debug-file-directory') and $datadir representing GDB's data
3344 directory (available via 'show data-directory').
3346 --with-auto-load-safe-path
3347 Configure default value for the 'set auto-load safe-path' setting
3348 above. It defaults to the --with-auto-load-dir setting.
3350 --without-auto-load-safe-path
3351 Set 'set auto-load safe-path' to '/', effectively disabling this
3354 * New remote packets
3356 z0/z1 conditional breakpoints extension
3358 The z0/z1 breakpoint insertion packets have been extended to carry
3359 a list of conditional expressions over to the remote stub depending on the
3360 condition evaluation mode. The use of this extension can be controlled
3361 via the "set remote conditional-breakpoints-packet" command.
3365 Specify the signals which the remote stub may pass to the debugged
3366 program without GDB involvement.
3368 * New command line options
3370 --init-command=FILE, -ix Like --command, -x but execute it
3371 before loading inferior.
3372 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3373 execute it before loading inferior.
3375 *** Changes in GDB 7.4
3377 * GDB now handles ambiguous linespecs more consistently; the existing
3378 FILE:LINE support has been expanded to other types of linespecs. A
3379 breakpoint will now be set on all matching locations in all
3380 inferiors, and locations will be added or removed according to
3383 * GDB now allows you to skip uninteresting functions and files when
3384 stepping with the "skip function" and "skip file" commands.
3386 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3387 and "show remote hardware-watchpoint-length-limit". These allows to
3388 set or show the maximum length limit (in bytes) of a remote
3389 target hardware watchpoint.
3391 This allows e.g. to use "unlimited" hardware watchpoints with the
3392 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3393 watchpoints are slower than real hardware watchpoints but are
3394 significantly faster than gdb software watchpoints.
3398 ** The register_pretty_printer function in module gdb.printing now takes
3399 an optional `replace' argument. If True, the new printer replaces any
3402 ** The "maint set python print-stack on|off" command has been
3403 deprecated and will be deleted in GDB 7.5.
3404 A new command: "set python print-stack none|full|message" has
3405 replaced it. Additionally, the default for "print-stack" is
3406 now "message", which just prints the error message without
3409 ** A prompt substitution hook (prompt_hook) is now available to the
3412 ** A new Python module, gdb.prompt has been added to the GDB Python
3413 modules library. This module provides functionality for
3414 escape sequences in prompts (used by set/show
3415 extended-prompt). These escape sequences are replaced by their
3416 corresponding value.
3418 ** Python commands and convenience-functions located in
3419 'data-directory'/python/gdb/command and
3420 'data-directory'/python/gdb/function are now automatically loaded
3423 ** Blocks now provide four new attributes. global_block and
3424 static_block will return the global and static blocks
3425 respectively. is_static and is_global are boolean attributes
3426 that indicate if the block is one of those two types.
3428 ** Symbols now provide the "type" attribute, the type of the symbol.
3430 ** The "gdb.breakpoint" function has been deprecated in favor of
3433 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3434 of a function. This class is based on the "finish" command
3435 available in the CLI.
3437 ** Type objects for struct and union types now allow access to
3438 the fields using standard Python dictionary (mapping) methods.
3439 For example, "some_type['myfield']" now works, as does
3440 "some_type.items()".
3442 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3445 ** A new function, "deep_items" has been added to the gdb.types
3446 module in the GDB Python modules library. This function returns
3447 an iterator over the fields of a struct or union type. Unlike
3448 the standard Python "iteritems" method, it will recursively traverse
3449 any anonymous fields.
3453 ** "*stopped" events can report several new "reason"s, such as
3456 ** Breakpoint changes are now notified using new async records, like
3457 "=breakpoint-modified".
3459 ** New command -ada-task-info.
3461 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3462 $sdir specifies the default system locations of shared libraries.
3463 $pdir specifies the directory where the libpthread used by the application
3466 GDB no longer looks in $sdir and $pdir after it has searched the directories
3467 mentioned in libthread-db-search-path. If you want to search those
3468 directories, they must be specified in libthread-db-search-path.
3469 The default value of libthread-db-search-path on GNU/Linux and Solaris
3470 systems is now "$sdir:$pdir".
3472 $pdir is not supported by gdbserver, it is currently ignored.
3473 $sdir is supported by gdbserver.
3475 * New configure option --with-iconv-bin.
3476 When using the internationalization support like the one in the GNU C
3477 library, GDB will invoke the "iconv" program to get a list of supported
3478 character sets. If this program lives in a non-standard location, one can
3479 use this option to specify where to find it.
3481 * When natively debugging programs on PowerPC BookE processors running
3482 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3483 watchpoints, which specify a mask in addition to an address to watch.
3484 The mask specifies that some bits of an address (the bits which are
3485 reset in the mask) should be ignored when matching the address accessed
3486 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3487 section in the user manual for more details.
3489 * The new option --once causes GDBserver to stop listening for connections once
3490 the first connection is made. The listening port used by GDBserver will
3491 become available after that.
3493 * New commands "info macros" and "alias" have been added.
3495 * New function parameters suffix @entry specifies value of function parameter
3496 at the time the function got called. Entry values are available only since
3502 "!" is now an alias of the "shell" command.
3503 Note that no space is needed between "!" and SHELL COMMAND.
3507 watch EXPRESSION mask MASK_VALUE
3508 The watch command now supports the mask argument which allows creation
3509 of masked watchpoints, if the current architecture supports this feature.
3511 info auto-load-scripts [REGEXP]
3512 This command was formerly named "maintenance print section-scripts".
3513 It is now generally useful and is no longer a maintenance-only command.
3515 info macro [-all] [--] MACRO
3516 The info macro command has new options `-all' and `--'. The first for
3517 printing all definitions of a macro. The second for explicitly specifying
3518 the end of arguments and the beginning of the macro name in case the macro
3519 name starts with a hyphen.
3521 collect[/s] EXPRESSIONS
3522 The tracepoint collect command now takes an optional modifier "/s"
3523 that directs it to dereference pointer-to-character types and
3524 collect the bytes of memory up to a zero byte. The behavior is
3525 similar to what you see when you use the regular print command on a
3526 string. An optional integer following the "/s" sets a bound on the
3527 number of bytes that will be collected.
3530 The trace start command now interprets any supplied arguments as a
3531 note to be recorded with the trace run, with an effect similar to
3532 setting the variable trace-notes.
3535 The trace stop command now interprets any arguments as a note to be
3536 mentioned along with the tstatus report that the trace was stopped
3537 with a command. The effect is similar to setting the variable
3540 * Tracepoints can now be enabled and disabled at any time after a trace
3541 experiment has been started using the standard "enable" and "disable"
3542 commands. It is now possible to start a trace experiment with no enabled
3543 tracepoints; GDB will display a warning, but will allow the experiment to
3544 begin, assuming that tracepoints will be enabled as needed while the trace
3547 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3548 locations with 4-byte instructions, when they were previously
3549 limited to locations with instructions of 5 bytes or longer.
3553 set debug dwarf2-read
3554 show debug dwarf2-read
3555 Turns on or off display of debugging messages related to reading
3556 DWARF debug info. The default is off.
3558 set debug symtab-create
3559 show debug symtab-create
3560 Turns on or off display of debugging messages related to symbol table
3561 creation. The default is off.
3564 show extended-prompt
3565 Set the GDB prompt, and allow escape sequences to be inserted to
3566 display miscellaneous information (see 'help set extended-prompt'
3567 for the list of sequences). This prompt (and any information
3568 accessed through the escape sequences) is updated every time the
3569 prompt is displayed.
3571 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3572 show print entry-values
3573 Set printing of frame argument values at function entry. In some cases
3574 GDB can determine the value of function argument which was passed by the
3575 function caller, even if the value was modified inside the called function.
3577 set debug entry-values
3578 show debug entry-values
3579 Control display of debugging info for determining frame argument values at
3580 function entry and virtual tail call frames.
3582 set basenames-may-differ
3583 show basenames-may-differ
3584 Set whether a source file may have multiple base names.
3585 (A "base name" is the name of a file with the directory part removed.
3586 Example: The base name of "/home/user/hello.c" is "hello.c".)
3587 If set, GDB will canonicalize file names (e.g., expand symlinks)
3588 before comparing them. Canonicalization is an expensive operation,
3589 but it allows the same file be known by more than one base name.
3590 If not set (the default), all source files are assumed to have just
3591 one base name, and gdb will do file name comparisons more efficiently.
3597 Set a user name and notes for the current and any future trace runs.
3598 This is useful for long-running and/or disconnected traces, to
3599 inform others (or yourself) as to who is running the trace, supply
3600 contact information, or otherwise explain what is going on.
3602 set trace-stop-notes
3603 show trace-stop-notes
3604 Set a note attached to the trace run, that is displayed when the
3605 trace has been stopped by a tstop command. This is useful for
3606 instance as an explanation, if you are stopping a trace run that was
3607 started by someone else.
3609 * New remote packets
3613 Dynamically enable a tracepoint in a started trace experiment.
3617 Dynamically disable a tracepoint in a started trace experiment.
3621 Set the user and notes of the trace run.
3625 Query the current status of a tracepoint.
3629 Query the minimum length of instruction at which a fast tracepoint may
3632 * Dcache size (number of lines) and line-size are now runtime-configurable
3633 via "set dcache line" and "set dcache line-size" commands.
3637 Texas Instruments TMS320C6x tic6x-*-*
3641 Renesas RL78 rl78-*-elf
3643 *** Changes in GDB 7.3.1
3645 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3647 *** Changes in GDB 7.3
3649 * GDB has a new command: "thread find [REGEXP]".
3650 It finds the thread id whose name, target id, or thread extra info
3651 matches the given regular expression.
3653 * The "catch syscall" command now works on mips*-linux* targets.
3655 * The -data-disassemble MI command now supports modes 2 and 3 for
3656 dumping the instruction opcodes.
3658 * New command line options
3660 -data-directory DIR Specify DIR as the "data-directory".
3661 This is mostly for testing purposes.
3663 * The "maint set python auto-load on|off" command has been renamed to
3664 "set auto-load-scripts on|off".
3666 * GDB has a new command: "set directories".
3667 It is like the "dir" command except that it replaces the
3668 source path list instead of augmenting it.
3670 * GDB now understands thread names.
3672 On GNU/Linux, "info threads" will display the thread name as set by
3673 prctl or pthread_setname_np.
3675 There is also a new command, "thread name", which can be used to
3676 assign a name internally for GDB to display.
3679 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3680 has been integrated into GDB.
3684 ** The function gdb.Write now accepts an optional keyword 'stream'.
3685 This keyword, when provided, will direct the output to either
3686 stdout, stderr, or GDB's logging output.
3688 ** Parameters can now be be sub-classed in Python, and in particular
3689 you may implement the get_set_doc and get_show_doc functions.
3690 This improves how Parameter set/show documentation is processed
3691 and allows for more dynamic content.
3693 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3694 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3695 have an is_valid method.
3697 ** Breakpoints can now be sub-classed in Python, and in particular
3698 you may implement a 'stop' function that is executed each time
3699 the inferior reaches that breakpoint.
3701 ** New function gdb.lookup_global_symbol looks up a global symbol.
3703 ** GDB values in Python are now callable if the value represents a
3704 function. For example, if 'some_value' represents a function that
3705 takes two integer parameters and returns a value, you can call
3706 that function like so:
3708 result = some_value (10,20)
3710 ** Module gdb.types has been added.
3711 It contains a collection of utilities for working with gdb.Types objects:
3712 get_basic_type, has_field, make_enum_dict.
3714 ** Module gdb.printing has been added.
3715 It contains utilities for writing and registering pretty-printers.
3716 New classes: PrettyPrinter, SubPrettyPrinter,
3717 RegexpCollectionPrettyPrinter.
3718 New function: register_pretty_printer.
3720 ** New commands "info pretty-printers", "enable pretty-printer" and
3721 "disable pretty-printer" have been added.
3723 ** gdb.parameter("directories") is now available.
3725 ** New function gdb.newest_frame returns the newest frame in the
3728 ** The gdb.InferiorThread class has a new "name" attribute. This
3729 holds the thread's name.
3731 ** Python Support for Inferior events.
3732 Python scripts can add observers to be notified of events
3733 occurring in the process being debugged.
3734 The following events are currently supported:
3735 - gdb.events.cont Continue event.
3736 - gdb.events.exited Inferior exited event.
3737 - gdb.events.stop Signal received, and Breakpoint hit events.
3741 ** GDB now puts template parameters in scope when debugging in an
3742 instantiation. For example, if you have:
3744 template<int X> int func (void) { return X; }
3746 then if you step into func<5>, "print X" will show "5". This
3747 feature requires proper debuginfo support from the compiler; it
3748 was added to GCC 4.5.
3750 ** The motion commands "next", "finish", "until", and "advance" now
3751 work better when exceptions are thrown. In particular, GDB will
3752 no longer lose control of the inferior; instead, the GDB will
3753 stop the inferior at the point at which the exception is caught.
3754 This functionality requires a change in the exception handling
3755 code that was introduced in GCC 4.5.
3757 * GDB now follows GCC's rules on accessing volatile objects when
3758 reading or writing target state during expression evaluation.
3759 One notable difference to prior behavior is that "print x = 0"
3760 no longer generates a read of x; the value of the assignment is
3761 now always taken directly from the value being assigned.
3763 * GDB now has some support for using labels in the program's source in
3764 linespecs. For instance, you can use "advance label" to continue
3765 execution to a label.
3767 * GDB now has support for reading and writing a new .gdb_index
3768 section. This section holds a fast index of DWARF debugging
3769 information and can be used to greatly speed up GDB startup and
3770 operation. See the documentation for `save gdb-index' for details.
3772 * The "watch" command now accepts an optional "-location" argument.
3773 When used, this causes GDB to watch the memory referred to by the
3774 expression. Such a watchpoint is never deleted due to it going out
3777 * GDB now supports thread debugging of core dumps on GNU/Linux.
3779 GDB now activates thread debugging using the libthread_db library
3780 when debugging GNU/Linux core dumps, similarly to when debugging
3781 live processes. As a result, when debugging a core dump file, GDB
3782 is now able to display pthread_t ids of threads. For example, "info
3783 threads" shows the same output as when debugging the process when it
3784 was live. In earlier releases, you'd see something like this:
3787 * 1 LWP 6780 main () at main.c:10
3789 While now you see this:
3792 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3794 It is also now possible to inspect TLS variables when debugging core
3797 When debugging a core dump generated on a machine other than the one
3798 used to run GDB, you may need to point GDB at the correct
3799 libthread_db library with the "set libthread-db-search-path"
3800 command. See the user manual for more details on this command.
3802 * When natively debugging programs on PowerPC BookE processors running
3803 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3804 which stop execution of the inferior whenever it executes an instruction
3805 at any address within the specified range. See the "PowerPC Embedded"
3806 section in the user manual for more details.
3808 * New features in the GDB remote stub, GDBserver
3810 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3811 and i686 LynxOS (version 5.x).
3813 ** GDBserver is now supported on Blackfin Linux.
3815 * New native configurations
3817 ia64 HP-UX ia64-*-hpux*
3821 Analog Devices, Inc. Blackfin Processor bfin-*
3823 * Ada task switching is now supported on sparc-elf targets when
3824 debugging a program using the Ravenscar Profile. For more information,
3825 see the "Tasking Support when using the Ravenscar Profile" section
3826 in the GDB user manual.
3828 * Guile support was removed.
3830 * New features in the GNU simulator
3832 ** The --map-info flag lists all known core mappings.
3834 ** CFI flashes may be simulated via the "cfi" device.
3836 *** Changes in GDB 7.2
3838 * Shared library support for remote targets by default
3840 When GDB is configured for a generic, non-OS specific target, like
3841 for example, --target=arm-eabi or one of the many *-*-elf targets,
3842 GDB now queries remote stubs for loaded shared libraries using the
3843 `qXfer:libraries:read' packet. Previously, shared library support
3844 was always disabled for such configurations.
3848 ** Argument Dependent Lookup (ADL)
3850 In C++ ADL lookup directs function search to the namespaces of its
3851 arguments even if the namespace has not been imported.
3861 Here the compiler will search for `foo' in the namespace of 'b'
3862 and find A::foo. GDB now supports this. This construct is commonly
3863 used in the Standard Template Library for operators.
3865 ** Improved User Defined Operator Support
3867 In addition to member operators, GDB now supports lookup of operators
3868 defined in a namespace and imported with a `using' directive, operators
3869 defined in the global scope, operators imported implicitly from an
3870 anonymous namespace, and the ADL operators mentioned in the previous
3872 GDB now also supports proper overload resolution for all the previously
3873 mentioned flavors of operators.
3875 ** static const class members
3877 Printing of static const class members that are initialized in the
3878 class definition has been fixed.
3880 * Windows Thread Information Block access.
3882 On Windows targets, GDB now supports displaying the Windows Thread
3883 Information Block (TIB) structure. This structure is visible either
3884 by using the new command `info w32 thread-information-block' or, by
3885 dereferencing the new convenience variable named `$_tlb', a
3886 thread-specific pointer to the TIB. This feature is also supported
3887 when remote debugging using GDBserver.
3889 * Static tracepoints
3891 Static tracepoints are calls in the user program into a tracing
3892 library. One such library is a port of the LTTng kernel tracer to
3893 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3894 When debugging with GDBserver, GDB now supports combining the GDB
3895 tracepoint machinery with such libraries. For example: the user can
3896 use GDB to probe a static tracepoint marker (a call from the user
3897 program into the tracing library) with the new "strace" command (see
3898 "New commands" below). This creates a "static tracepoint" in the
3899 breakpoint list, that can be manipulated with the same feature set
3900 as fast and regular tracepoints. E.g., collect registers, local and
3901 global variables, collect trace state variables, and define
3902 tracepoint conditions. In addition, the user can collect extra
3903 static tracepoint marker specific data, by collecting the new
3904 $_sdata internal variable. When analyzing the trace buffer, you can
3905 inspect $_sdata like any other variable available to GDB. For more
3906 information, see the "Tracepoints" chapter in GDB user manual. New
3907 remote packets have been defined to support static tracepoints, see
3908 the "New remote packets" section below.
3910 * Better reconstruction of tracepoints after disconnected tracing
3912 GDB will attempt to download the original source form of tracepoint
3913 definitions when starting a trace run, and then will upload these
3914 upon reconnection to the target, resulting in a more accurate
3915 reconstruction of the tracepoints that are in use on the target.
3919 You can now exercise direct control over the ways that GDB can
3920 affect your program. For instance, you can disallow the setting of
3921 breakpoints, so that the program can run continuously (assuming
3922 non-stop mode). In addition, the "observer" variable is available
3923 to switch all of the different controls; in observer mode, GDB
3924 cannot affect the target's behavior at all, which is useful for
3925 tasks like diagnosing live systems in the field.
3927 * The new convenience variable $_thread holds the number of the
3930 * New remote packets
3934 Return the address of the Windows Thread Information Block of a given thread.
3938 In response to several of the tracepoint packets, the target may now
3939 also respond with a number of intermediate `qRelocInsn' request
3940 packets before the final result packet, to have GDB handle
3941 relocating an instruction to execute at a different address. This
3942 is particularly useful for stubs that support fast tracepoints. GDB
3943 reports support for this feature in the qSupported packet.
3947 List static tracepoint markers in the target program.
3951 List static tracepoint markers at a given address in the target
3954 qXfer:statictrace:read
3956 Read the static trace data collected (by a `collect $_sdata'
3957 tracepoint action). The remote stub reports support for this packet
3958 to gdb's qSupported query.
3962 Send the current settings of GDB's permission flags.
3966 Send part of the source (textual) form of a tracepoint definition,
3967 which includes location, conditional, and action list.
3969 * The source command now accepts a -s option to force searching for the
3970 script in the source search path even if the script name specifies
3973 * New features in the GDB remote stub, GDBserver
3975 - GDBserver now support tracepoints (including fast tracepoints, and
3976 static tracepoints). The feature is currently supported by the
3977 i386-linux and amd64-linux builds. See the "Tracepoints support
3978 in gdbserver" section in the manual for more information.
3980 GDBserver JIT compiles the tracepoint's conditional agent
3981 expression bytecode into native code whenever possible for low
3982 overhead dynamic tracepoints conditionals. For such tracepoints,
3983 an expression that examines program state is evaluated when the
3984 tracepoint is reached, in order to determine whether to capture
3985 trace data. If the condition is simple and false, processing the
3986 tracepoint finishes very quickly and no data is gathered.
3988 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3989 for static tracepoints support.
3991 - GDBserver now supports x86_64 Windows 64-bit debugging.
3993 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3994 it understands register description.
3996 * The --batch flag now disables pagination and queries.
3998 * X86 general purpose registers
4000 GDB now supports reading/writing byte, word and double-word x86
4001 general purpose registers directly. This means you can use, say,
4002 $ah or $ax to refer, respectively, to the byte register AH and
4003 16-bit word register AX that are actually portions of the 32-bit
4004 register EAX or 64-bit register RAX.
4006 * The `commands' command now accepts a range of breakpoints to modify.
4007 A plain `commands' following a command that creates multiple
4008 breakpoints affects all the breakpoints set by that command. This
4009 applies to breakpoints set by `rbreak', and also applies when a
4010 single `break' command creates multiple breakpoints (e.g.,
4011 breakpoints on overloaded c++ functions).
4013 * The `rbreak' command now accepts a filename specification as part of
4014 its argument, limiting the functions selected by the regex to those
4015 in the specified file.
4017 * Support for remote debugging Windows and SymbianOS shared libraries
4018 from Unix hosts has been improved. Non Windows GDB builds now can
4019 understand target reported file names that follow MS-DOS based file
4020 system semantics, such as file names that include drive letters and
4021 use the backslash character as directory separator. This makes it
4022 possible to transparently use the "set sysroot" and "set
4023 solib-search-path" on Unix hosts to point as host copies of the
4024 target's shared libraries. See the new command "set
4025 target-file-system-kind" described below, and the "Commands to
4026 specify files" section in the user manual for more information.
4030 eval template, expressions...
4031 Convert the values of one or more expressions under the control
4032 of the string template to a command line, and call it.
4034 set target-file-system-kind unix|dos-based|auto
4035 show target-file-system-kind
4036 Set or show the assumed file system kind for target reported file
4039 save breakpoints <filename>
4040 Save all current breakpoint definitions to a file suitable for use
4041 in a later debugging session. To read the saved breakpoint
4042 definitions, use the `source' command.
4044 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4047 info static-tracepoint-markers
4048 Display information about static tracepoint markers in the target.
4050 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4051 Define a static tracepoint by probing a marker at the given
4052 function, line, address, or marker ID.
4056 Enable and disable observer mode.
4058 set may-write-registers on|off
4059 set may-write-memory on|off
4060 set may-insert-breakpoints on|off
4061 set may-insert-tracepoints on|off
4062 set may-insert-fast-tracepoints on|off
4063 set may-interrupt on|off
4064 Set individual permissions for GDB effects on the target. Note that
4065 some of these settings can have undesirable or surprising
4066 consequences, particularly when changed in the middle of a session.
4067 For instance, disabling the writing of memory can prevent
4068 breakpoints from being inserted, cause single-stepping to fail, or
4069 even crash your program, if you disable after breakpoints have been
4070 inserted. However, GDB should not crash.
4072 set record memory-query on|off
4073 show record memory-query
4074 Control whether to stop the inferior if memory changes caused
4075 by an instruction cannot be recorded.
4080 The disassemble command now supports "start,+length" form of two arguments.
4084 ** GDB now provides a new directory location, called the python directory,
4085 where Python scripts written for GDB can be installed. The location
4086 of that directory is <data-directory>/python, where <data-directory>
4087 is the GDB data directory. For more details, see section `Scripting
4088 GDB using Python' in the manual.
4090 ** The GDB Python API now has access to breakpoints, symbols, symbol
4091 tables, program spaces, inferiors, threads and frame's code blocks.
4092 Additionally, GDB Parameters can now be created from the API, and
4093 manipulated via set/show in the CLI.
4095 ** New functions gdb.target_charset, gdb.target_wide_charset,
4096 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4098 ** New exception gdb.GdbError.
4100 ** Pretty-printers are now also looked up in the current program space.
4102 ** Pretty-printers can now be individually enabled and disabled.
4104 ** GDB now looks for names of Python scripts to auto-load in a
4105 special section named `.debug_gdb_scripts', in addition to looking
4106 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4108 * Tracepoint actions were unified with breakpoint commands. In particular,
4109 there are no longer differences in "info break" output for breakpoints and
4110 tracepoints and the "commands" command can be used for both tracepoints and
4111 regular breakpoints.
4115 ARM Symbian arm*-*-symbianelf*
4117 * D language support.
4118 GDB now supports debugging programs written in the D programming
4121 * GDB now supports the extended ptrace interface for PowerPC which is
4122 available since Linux kernel version 2.6.34. This automatically enables
4123 any hardware breakpoints and additional hardware watchpoints available in
4124 the processor. The old ptrace interface exposes just one hardware
4125 watchpoint and no hardware breakpoints.
4127 * GDB is now able to use the Data Value Compare (DVC) register available on
4128 embedded PowerPC processors to implement in hardware simple watchpoint
4129 conditions of the form:
4131 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4133 This works in native GDB running on Linux kernels with the extended ptrace
4134 interface mentioned above.
4136 *** Changes in GDB 7.1
4140 ** Namespace Support
4142 GDB now supports importing of namespaces in C++. This enables the
4143 user to inspect variables from imported namespaces. Support for
4144 namepace aliasing has also been added. So, if a namespace is
4145 aliased in the current scope (e.g. namepace C=A; ) the user can
4146 print variables using the alias (e.g. (gdb) print C::x).
4150 All known bugs relating to the printing of virtual base class were
4151 fixed. It is now possible to call overloaded static methods using a
4156 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4157 and reinterpret_cast<> are now handled by the C++ expression parser.
4161 Xilinx MicroBlaze microblaze-*-*
4166 Xilinx MicroBlaze microblaze
4169 * Multi-program debugging.
4171 GDB now has support for multi-program (a.k.a. multi-executable or
4172 multi-exec) debugging. This allows for debugging multiple inferiors
4173 simultaneously each running a different program under the same GDB
4174 session. See "Debugging Multiple Inferiors and Programs" in the
4175 manual for more information. This implied some user visible changes
4176 in the multi-inferior support. For example, "info inferiors" now
4177 lists inferiors that are not running yet or that have exited
4178 already. See also "New commands" and "New options" below.
4180 * New tracing features
4182 GDB's tracepoint facility now includes several new features:
4184 ** Trace state variables
4186 GDB tracepoints now include support for trace state variables, which
4187 are variables managed by the target agent during a tracing
4188 experiment. They are useful for tracepoints that trigger each
4189 other, so for instance one tracepoint can count hits in a variable,
4190 and then a second tracepoint has a condition that is true when the
4191 count reaches a particular value. Trace state variables share the
4192 $-syntax of GDB convenience variables, and can appear in both
4193 tracepoint actions and condition expressions. Use the "tvariable"
4194 command to create, and "info tvariables" to view; see "Trace State
4195 Variables" in the manual for more detail.
4199 GDB now includes an option for defining fast tracepoints, which
4200 targets may implement more efficiently, such as by installing a jump
4201 into the target agent rather than a trap instruction. The resulting
4202 speedup can be by two orders of magnitude or more, although the
4203 tradeoff is that some program locations on some target architectures
4204 might not allow fast tracepoint installation, for instance if the
4205 instruction to be replaced is shorter than the jump. To request a
4206 fast tracepoint, use the "ftrace" command, with syntax identical to
4207 the regular trace command.
4209 ** Disconnected tracing
4211 It is now possible to detach GDB from the target while it is running
4212 a trace experiment, then reconnect later to see how the experiment
4213 is going. In addition, a new variable disconnected-tracing lets you
4214 tell the target agent whether to continue running a trace if the
4215 connection is lost unexpectedly.
4219 GDB now has the ability to save the trace buffer into a file, and
4220 then use that file as a target, similarly to you can do with
4221 corefiles. You can select trace frames, print data that was
4222 collected in them, and use tstatus to display the state of the
4223 tracing run at the moment that it was saved. To create a trace
4224 file, use "tsave <filename>", and to use it, do "target tfile
4227 ** Circular trace buffer
4229 You can ask the target agent to handle the trace buffer as a
4230 circular buffer, discarding the oldest trace frames to make room for
4231 newer ones, by setting circular-trace-buffer to on. This feature may
4232 not be available for all target agents.
4237 The disassemble command, when invoked with two arguments, now requires
4238 the arguments to be comma-separated.
4241 The info variables command now displays variable definitions. Files
4242 which only declare a variable are not shown.
4245 The source command is now capable of sourcing Python scripts.
4246 This feature is dependent on the debugger being build with Python
4249 Related to this enhancement is also the introduction of a new command
4250 "set script-extension" (see below).
4252 * New commands (for set/show, see "New options" below)
4254 record save [<FILENAME>]
4255 Save a file (in core file format) containing the process record
4256 execution log for replay debugging at a later time.
4258 record restore <FILENAME>
4259 Restore the process record execution log that was saved at an
4260 earlier time, for replay debugging.
4262 add-inferior [-copies <N>] [-exec <FILENAME>]
4265 clone-inferior [-copies <N>] [ID]
4266 Make a new inferior ready to execute the same program another
4267 inferior has loaded.
4272 maint info program-spaces
4273 List the program spaces loaded into GDB.
4275 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4276 show remote interrupt-sequence
4277 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4278 as the sequence to the remote target in order to interrupt the execution.
4279 Ctrl-C is a default. Some system prefers BREAK which is high level of
4280 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4281 Magic SysRq g. It is BREAK signal and character 'g'.
4283 set remote interrupt-on-connect [on | off]
4284 show remote interrupt-on-connect
4285 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4286 remote target when gdb connects to it. This is needed when you debug
4289 set remotebreak [on | off]
4291 Deprecated. Use "set/show remote interrupt-sequence" instead.
4293 tvariable $NAME [ = EXP ]
4294 Create or modify a trace state variable.
4297 List trace state variables and their values.
4299 delete tvariable $NAME ...
4300 Delete one or more trace state variables.
4303 Evaluate the given expressions without collecting anything into the
4304 trace buffer. (Valid in tracepoint actions only.)
4306 ftrace FN / FILE:LINE / *ADDR
4307 Define a fast tracepoint at the given function, line, or address.
4309 * New expression syntax
4311 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4312 GDB now parses 0b101010 identically with 42.
4316 set follow-exec-mode new|same
4317 show follow-exec-mode
4318 Control whether GDB reuses the same inferior across an exec call or
4319 creates a new one. This is useful to be able to restart the old
4320 executable after the inferior having done an exec call.
4322 set default-collect EXPR, ...
4323 show default-collect
4324 Define a list of expressions to be collected at each tracepoint.
4325 This is a useful way to ensure essential items are not overlooked,
4326 such as registers or a critical global variable.
4328 set disconnected-tracing
4329 show disconnected-tracing
4330 If set to 1, the target is instructed to continue tracing if it
4331 loses its connection to GDB. If 0, the target is to stop tracing
4334 set circular-trace-buffer
4335 show circular-trace-buffer
4336 If set to on, the target is instructed to use a circular trace buffer
4337 and discard the oldest trace frames instead of stopping the trace due
4338 to a full trace buffer. If set to off, the trace stops when the buffer
4339 fills up. Some targets may not support this.
4341 set script-extension off|soft|strict
4342 show script-extension
4343 If set to "off", the debugger does not perform any script language
4344 recognition, and all sourced files are assumed to be GDB scripts.
4345 If set to "soft" (the default), files are sourced according to
4346 filename extension, falling back to GDB scripts if the first
4348 If set to "strict", files are sourced according to filename extension.
4350 set ada trust-PAD-over-XVS on|off
4351 show ada trust-PAD-over-XVS
4352 If off, activate a workaround against a bug in the debugging information
4353 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4354 the GCC sources for more information about the GNAT encoding and
4355 PAD types in particular). It is always safe to set this option to
4356 off, but this introduces a slight performance penalty. The default
4359 * Python API Improvements
4361 ** GDB provides the new class gdb.LazyString. This is useful in
4362 some pretty-printing cases. The new method gdb.Value.lazy_string
4363 provides a simple way to create objects of this type.
4365 ** The fields returned by gdb.Type.fields now have an
4366 `is_base_class' attribute.
4368 ** The new method gdb.Type.range returns the range of an array type.
4370 ** The new method gdb.parse_and_eval can be used to parse and
4371 evaluate an expression.
4373 * New remote packets
4376 Define a trace state variable.
4379 Get the current value of a trace state variable.
4382 Set desired tracing behavior upon disconnection.
4385 Set the trace buffer to be linear or circular.
4388 Get data about the tracepoints currently in use.
4392 Process record now works correctly with hardware watchpoints.
4394 Multiple bug fixes have been made to the mips-irix port, making it
4395 much more reliable. In particular:
4396 - Debugging threaded applications is now possible again. Previously,
4397 GDB would hang while starting the program, or while waiting for
4398 the program to stop at a breakpoint.
4399 - Attaching to a running process no longer hangs.
4400 - An error occurring while loading a core file has been fixed.
4401 - Changing the value of the PC register now works again. This fixes
4402 problems observed when using the "jump" command, or when calling
4403 a function from GDB, or even when assigning a new value to $pc.
4404 - With the "finish" and "return" commands, the return value for functions
4405 returning a small array is now correctly printed.
4406 - It is now possible to break on shared library code which gets executed
4407 during a shared library init phase (code executed while executing
4408 their .init section). Previously, the breakpoint would have no effect.
4409 - GDB is now able to backtrace through the signal handler for
4410 non-threaded programs.
4412 PIE (Position Independent Executable) programs debugging is now supported.
4413 This includes debugging execution of PIC (Position Independent Code) shared
4414 libraries although for that, it should be possible to run such libraries as an
4417 *** Changes in GDB 7.0
4419 * GDB now has an interface for JIT compilation. Applications that
4420 dynamically generate code can create symbol files in memory and register
4421 them with GDB. For users, the feature should work transparently, and
4422 for JIT developers, the interface is documented in the GDB manual in the
4423 "JIT Compilation Interface" chapter.
4425 * Tracepoints may now be conditional. The syntax is as for
4426 breakpoints; either an "if" clause appended to the "trace" command,
4427 or the "condition" command is available. GDB sends the condition to
4428 the target for evaluation using the same bytecode format as is used
4429 for tracepoint actions.
4431 * The disassemble command now supports: an optional /r modifier, print the
4432 raw instructions in hex as well as in symbolic form, and an optional /m
4433 modifier to print mixed source+assembly.
4435 * Process record and replay
4437 In a architecture environment that supports ``process record and
4438 replay'', ``process record and replay'' target can record a log of
4439 the process execution, and replay it with both forward and reverse
4442 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4443 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4444 set execution-direction {forward|reverse}, for targets that support
4447 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4448 feature is available with a native GDB running on kernel version
4451 * GDB now has support for multi-byte and wide character sets on the
4452 target. Strings whose character type is wchar_t, char16_t, or
4453 char32_t are now correctly printed. GDB supports wide- and unicode-
4454 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4455 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4456 `printf'. This feature requires iconv to work properly; if your
4457 system does not have a working iconv, GDB can use GNU libiconv. See
4458 the installation instructions for more information.
4460 * GDB now supports automatic retrieval of shared library files from
4461 remote targets. To use this feature, specify a system root that begins
4462 with the `remote:' prefix, either via the `set sysroot' command or via
4463 the `--with-sysroot' configure-time option.
4465 * "info sharedlibrary" now takes an optional regex of libraries to show,
4466 and it now reports if a shared library has no debugging information.
4468 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4469 now complete on file names.
4471 * When completing in expressions, gdb will attempt to limit
4472 completions to allowable structure or union fields, where appropriate.
4473 For instance, consider:
4475 # struct example { int f1; double f2; };
4476 # struct example variable;
4479 If the user types TAB at the end of this command line, the available
4480 completions will be "f1" and "f2".
4482 * Inlined functions are now supported. They show up in backtraces, and
4483 the "step", "next", and "finish" commands handle them automatically.
4485 * GDB now supports the token-splicing (##) and stringification (#)
4486 operators when expanding macros. It also supports variable-arity
4489 * GDB now supports inspecting extra signal information, exported by
4490 the new $_siginfo convenience variable. The feature is currently
4491 implemented on linux ARM, i386 and amd64.
4493 * GDB can now display the VFP floating point registers and NEON vector
4494 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4495 can provide these registers (requires Linux 2.6.30 or later). Remote
4496 and simulator targets may also provide them.
4498 * New remote packets
4501 Search memory for a sequence of bytes.
4504 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4505 operation over reliable transport links. Use of this packet is
4506 controlled by the `set remote noack-packet' command.
4509 Kill the process with the specified process ID. Use this in preference
4510 to `k' when multiprocess protocol extensions are supported.
4513 Obtains additional operating system information
4517 Read or write additional signal information.
4519 * Removed remote protocol undocumented extension
4521 An undocumented extension to the remote protocol's `S' stop reply
4522 packet that permitted the stub to pass a process id was removed.
4523 Remote servers should use the `T' stop reply packet instead.
4525 * GDB now supports multiple function calling conventions according to the
4526 DWARF-2 DW_AT_calling_convention function attribute.
4528 * The SH target utilizes the aforementioned change to distinguish between gcc
4529 and Renesas calling convention. It also adds the new CLI commands
4530 `set/show sh calling-convention'.
4532 * GDB can now read compressed debug sections, as produced by GNU gold
4533 with the --compress-debug-sections=zlib flag.
4535 * 64-bit core files are now supported on AIX.
4537 * Thread switching is now supported on Tru64.
4539 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4540 which will be allocated using malloc later in program execution.
4542 * The qXfer:libraries:read remote protocol packet now allows passing a
4543 list of section offsets.
4545 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4546 conditions handling signals delivered during attach or thread creation
4547 have also been fixed.
4549 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4550 From the user's standpoint, all unqualified instances of True and False
4551 are treated as the standard definitions, regardless of context.
4553 * GDB now parses C++ symbol and type names more flexibly. For
4556 template<typename T> class C { };
4559 GDB will now correctly handle all of:
4561 ptype C<char const *>
4562 ptype C<char const*>
4563 ptype C<const char *>
4564 ptype C<const char*>
4566 * New features in the GDB remote stub, gdbserver
4568 - The "--wrapper" command-line argument tells gdbserver to use a
4569 wrapper program to launch programs for debugging.
4571 - On PowerPC and S/390 targets, it is now possible to use a single
4572 gdbserver executable to debug both 32-bit and 64-bit programs.
4573 (This requires gdbserver itself to be built as a 64-bit executable.)
4575 - gdbserver uses the new noack protocol mode for TCP connections to
4576 reduce communications latency, if also supported and enabled in GDB.
4578 - Support for the sparc64-linux-gnu target is now included in
4581 - The amd64-linux build of gdbserver now supports debugging both
4582 32-bit and 64-bit programs.
4584 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4585 now support hardware watchpoints, and will use them automatically
4590 GDB now has support for scripting using Python. Whether this is
4591 available is determined at configure time.
4593 New GDB commands can now be written in Python.
4595 * Ada tasking support
4597 Ada tasks can now be inspected in GDB. The following commands have
4601 Print the list of Ada tasks.
4603 Print detailed information about task number N.
4605 Print the task number of the current task.
4607 Switch the context of debugging to task number N.
4609 * Support for user-defined prefixed commands. The "define" command can
4610 add new commands to existing prefixes, e.g. "target".
4612 * Multi-inferior, multi-process debugging.
4614 GDB now has generalized support for multi-inferior debugging. See
4615 "Debugging Multiple Inferiors" in the manual for more information.
4616 Although availability still depends on target support, the command
4617 set is more uniform now. The GNU/Linux specific multi-forks support
4618 has been migrated to this new framework. This implied some user
4619 visible changes; see "New commands" and also "Removed commands"
4622 * Target descriptions can now describe the target OS ABI. See the
4623 "Target Description Format" section in the user manual for more
4626 * Target descriptions can now describe "compatible" architectures
4627 to indicate that the target can execute applications for a different
4628 architecture in addition to those for the main target architecture.
4629 See the "Target Description Format" section in the user manual for
4632 * Multi-architecture debugging.
4634 GDB now includes general supports for debugging applications on
4635 hybrid systems that use more than one single processor architecture
4636 at the same time. Each such hybrid architecture still requires
4637 specific support to be added. The only hybrid architecture supported
4638 in this version of GDB is the Cell Broadband Engine.
4640 * GDB now supports integrated debugging of Cell/B.E. applications that
4641 use both the PPU and SPU architectures. To enable support for hybrid
4642 Cell/B.E. debugging, you need to configure GDB to support both the
4643 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4644 --enable-targets configure option.
4646 * Non-stop mode debugging.
4648 For some targets, GDB now supports an optional mode of operation in
4649 which you can examine stopped threads while other threads continue
4650 to execute freely. This is referred to as non-stop mode, with the
4651 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4652 section in the user manual for more information.
4654 To be able to support remote non-stop debugging, a remote stub needs
4655 to implement the non-stop mode remote protocol extensions, as
4656 described in the "Remote Non-Stop" section of the user manual. The
4657 GDB remote stub, gdbserver, has been adjusted to support these
4658 extensions on linux targets.
4660 * New commands (for set/show, see "New options" below)
4662 catch syscall [NAME(S) | NUMBER(S)]
4663 Catch system calls. Arguments, which should be names of system
4664 calls or their numbers, mean catch only those syscalls. Without
4665 arguments, every syscall will be caught. When the inferior issues
4666 any of the specified syscalls, GDB will stop and announce the system
4667 call, both when it is called and when its call returns. This
4668 feature is currently available with a native GDB running on the
4669 Linux Kernel, under the following architectures: x86, x86_64,
4670 PowerPC and PowerPC64.
4672 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4674 Search memory for a sequence of bytes.
4676 maint set python print-stack
4677 maint show python print-stack
4678 Show a stack trace when an error is encountered in a Python script.
4681 Invoke CODE by passing it to the Python interpreter.
4686 These allow macros to be defined, undefined, and listed
4690 Show operating system information about processes.
4693 List the inferiors currently under GDB's control.
4696 Switch focus to inferior number NUM.
4699 Detach from inferior number NUM.
4702 Kill inferior number NUM.
4706 set spu stop-on-load
4707 show spu stop-on-load
4708 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4710 set spu auto-flush-cache
4711 show spu auto-flush-cache
4712 Control whether to automatically flush the software-managed cache
4713 during Cell/B.E. debugging.
4715 set sh calling-convention
4716 show sh calling-convention
4717 Control the calling convention used when calling SH target functions.
4720 show debug timestamp
4721 Control display of timestamps with GDB debugging output.
4723 set disassemble-next-line
4724 show disassemble-next-line
4725 Control display of disassembled source lines or instructions when
4728 set remote noack-packet
4729 show remote noack-packet
4730 Set/show the use of remote protocol QStartNoAckMode packet. See above
4731 under "New remote packets."
4733 set remote query-attached-packet
4734 show remote query-attached-packet
4735 Control use of remote protocol `qAttached' (query-attached) packet.
4737 set remote read-siginfo-object
4738 show remote read-siginfo-object
4739 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4742 set remote write-siginfo-object
4743 show remote write-siginfo-object
4744 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4747 set remote reverse-continue
4748 show remote reverse-continue
4749 Control use of remote protocol 'bc' (reverse-continue) packet.
4751 set remote reverse-step
4752 show remote reverse-step
4753 Control use of remote protocol 'bs' (reverse-step) packet.
4755 set displaced-stepping
4756 show displaced-stepping
4757 Control displaced stepping mode. Displaced stepping is a way to
4758 single-step over breakpoints without removing them from the debuggee.
4759 Also known as "out-of-line single-stepping".
4762 show debug displaced
4763 Control display of debugging info for displaced stepping.
4765 maint set internal-error
4766 maint show internal-error
4767 Control what GDB does when an internal error is detected.
4769 maint set internal-warning
4770 maint show internal-warning
4771 Control what GDB does when an internal warning is detected.
4776 Use a wrapper program to launch programs for debugging.
4778 set multiple-symbols (all|ask|cancel)
4779 show multiple-symbols
4780 The value of this variable can be changed to adjust the debugger behavior
4781 when an expression or a breakpoint location contains an ambiguous symbol
4782 name (an overloaded function name, for instance).
4784 set breakpoint always-inserted
4785 show breakpoint always-inserted
4786 Keep breakpoints always inserted in the target, as opposed to inserting
4787 them when resuming the target, and removing them when the target stops.
4788 This option can improve debugger performance on slow remote targets.
4790 set arm fallback-mode (arm|thumb|auto)
4791 show arm fallback-mode
4792 set arm force-mode (arm|thumb|auto)
4794 These commands control how ARM GDB determines whether instructions
4795 are ARM or Thumb. The default for both settings is auto, which uses
4796 the current CPSR value for instructions without symbols; previous
4797 versions of GDB behaved as if "set arm fallback-mode arm".
4799 set disable-randomization
4800 show disable-randomization
4801 Standalone programs run with the virtual address space randomization enabled
4802 by default on some platforms. This option keeps the addresses stable across
4803 multiple debugging sessions.
4807 Control whether other threads are stopped or not when some thread hits
4812 Requests that asynchronous execution is enabled in the target, if available.
4813 In this case, it's possible to resume target in the background, and interact
4814 with GDB while the target is running. "show target-async" displays the
4815 current state of asynchronous execution of the target.
4817 set target-wide-charset
4818 show target-wide-charset
4819 The target-wide-charset is the name of the character set that GDB
4820 uses when printing characters whose type is wchar_t.
4822 set tcp auto-retry (on|off)
4824 set tcp connect-timeout
4825 show tcp connect-timeout
4826 These commands allow GDB to retry failed TCP connections to a remote stub
4827 with a specified timeout period; this is useful if the stub is launched
4828 in parallel with GDB but may not be ready to accept connections immediately.
4830 set libthread-db-search-path
4831 show libthread-db-search-path
4832 Control list of directories which GDB will search for appropriate
4835 set schedule-multiple (on|off)
4836 show schedule-multiple
4837 Allow GDB to resume all threads of all processes or only threads of
4838 the current process.
4842 Use more aggressive caching for accesses to the stack. This improves
4843 performance of remote debugging (particularly backtraces) without
4844 affecting correctness.
4846 set interactive-mode (on|off|auto)
4847 show interactive-mode
4848 Control whether GDB runs in interactive mode (on) or not (off).
4849 When in interactive mode, GDB waits for the user to answer all
4850 queries. Otherwise, GDB does not wait and assumes the default
4851 answer. When set to auto (the default), GDB determines which
4852 mode to use based on the stdin settings.
4857 For program forks, this is replaced by the new more generic `info
4858 inferiors' command. To list checkpoints, you can still use the
4859 `info checkpoints' command, which was an alias for the `info forks'
4863 Replaced by the new `inferior' command. To switch between
4864 checkpoints, you can still use the `restart' command, which was an
4865 alias for the `fork' command.
4868 This is removed, since some targets don't have a notion of
4869 processes. To switch between processes, you can still use the
4870 `inferior' command using GDB's own inferior number.
4873 For program forks, this is replaced by the new more generic `kill
4874 inferior' command. To delete a checkpoint, you can still use the
4875 `delete checkpoint' command, which was an alias for the `delete
4879 For program forks, this is replaced by the new more generic `detach
4880 inferior' command. To detach a checkpoint, you can still use the
4881 `detach checkpoint' command, which was an alias for the `detach
4884 * New native configurations
4886 x86/x86_64 Darwin i[34567]86-*-darwin*
4888 x86_64 MinGW x86_64-*-mingw*
4892 Lattice Mico32 lm32-*
4893 x86 DICOS i[34567]86-*-dicos*
4894 x86_64 DICOS x86_64-*-dicos*
4897 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4898 (mingw32ce) debugging.
4904 These commands were actually not implemented on any target.
4906 *** Changes in GDB 6.8
4908 * New native configurations
4910 NetBSD/hppa hppa*-*netbsd*
4911 Xtensa GNU/Linux xtensa*-*-linux*
4915 NetBSD/hppa hppa*-*-netbsd*
4916 Xtensa GNU/Linux xtensa*-*-linux*
4918 * Change in command line behavior -- corefiles vs. process ids.
4920 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4921 attaching to process NUMBER fails, GDB no longer attempts to open a
4922 core file named NUMBER. Attaching to a program using the -c option
4923 is no longer supported. Instead, use the '-p' or '--pid' options.
4925 * GDB can now be built as a native debugger for debugging Windows x86
4926 (mingw32) Portable Executable (PE) programs.
4928 * Pending breakpoints no longer change their number when their address
4931 * GDB now supports breakpoints with multiple locations,
4932 including breakpoints on C++ constructors, inside C++ templates,
4933 and in inlined functions.
4935 * GDB's ability to debug optimized code has been improved. GDB more
4936 accurately identifies function bodies and lexical blocks that occupy
4937 more than one contiguous range of addresses.
4939 * Target descriptions can now describe registers for PowerPC.
4941 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4942 registers on PowerPC targets.
4944 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4945 targets even when the libthread_db library is not available.
4947 * The GDB remote stub, gdbserver, now supports the new file transfer
4948 commands (remote put, remote get, and remote delete).
4950 * The GDB remote stub, gdbserver, now supports run and attach in
4951 extended-remote mode.
4953 * hppa*64*-*-hpux11* target broken
4954 The debugger is unable to start a program and fails with the following
4955 error: "Error trying to get information about dynamic linker".
4956 The gdb-6.7 release is also affected.
4958 * GDB now supports the --enable-targets= configure option to allow
4959 building a single GDB executable that supports multiple remote
4960 target architectures.
4962 * GDB now supports debugging C and C++ programs which use the
4963 Decimal Floating Point extension. In addition, the PowerPC target
4964 now has a set of pseudo-registers to inspect decimal float values
4965 stored in two consecutive float registers.
4967 * The -break-insert MI command can optionally create pending
4970 * Improved support for debugging Ada
4971 Many improvements to the Ada language support have been made. These
4973 - Better support for Ada2005 interface types
4974 - Improved handling of arrays and slices in general
4975 - Better support for Taft-amendment types
4976 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4978 - Improved command completion in Ada
4981 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4986 set print frame-arguments (all|scalars|none)
4987 show print frame-arguments
4988 The value of this variable can be changed to control which argument
4989 values should be printed by the debugger when displaying a frame.
4994 Transfer files to and from a remote target, and delete remote files.
5001 Transfer files to and from a remote target, and delete remote files.
5003 * New remote packets
5010 Open, close, read, write, and delete files on the remote system.
5013 Attach to an existing process on the remote system, in extended-remote
5017 Run a new process on the remote system, in extended-remote mode.
5019 *** Changes in GDB 6.7
5021 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5022 bfd, libiberty and opcodes, as revealed by static analysis donated by
5023 Coverity, Inc. (http://scan.coverity.com).
5025 * When looking up multiply-defined global symbols, GDB will now prefer the
5026 symbol definition in the current shared library if it was built using the
5027 -Bsymbolic linker option.
5029 * When the Text User Interface (TUI) is not configured, GDB will now
5030 recognize the -tui command-line option and print a message that the TUI
5033 * The GDB remote stub, gdbserver, now has lower overhead for high
5034 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5036 * GDB for MIPS targets now autodetects whether a remote target provides
5037 32-bit or 64-bit register values.
5039 * Support for C++ member pointers has been improved.
5041 * GDB now understands XML target descriptions, which specify the
5042 target's overall architecture. GDB can read a description from
5043 a local file or over the remote serial protocol.
5045 * Vectors of single-byte data use a new integer type which is not
5046 automatically displayed as character or string data.
5048 * The /s format now works with the print command. It displays
5049 arrays of single-byte integers and pointers to single-byte integers
5052 * Target descriptions can now describe target-specific registers,
5053 for architectures which have implemented the support (currently
5054 only ARM, M68K, and MIPS).
5056 * GDB and the GDB remote stub, gdbserver, now support the XScale
5059 * The GDB remote stub, gdbserver, has been updated to support
5060 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5061 has been rewritten to use the standard GDB remote protocol.
5063 * GDB can now step into C++ functions which are called through thunks.
5065 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5067 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5068 layout. It also supports a TextSeg= and DataSeg= response when only
5069 segment base addresses (rather than offsets) are available.
5071 * The /i format now outputs any trailing branch delay slot instructions
5072 immediately following the last instruction within the count specified.
5074 * The GDB remote protocol "T" stop reply packet now supports a
5075 "library" response. Combined with the new "qXfer:libraries:read"
5076 packet, this response allows GDB to debug shared libraries on targets
5077 where the operating system manages the list of loaded libraries (e.g.
5078 Windows and SymbianOS).
5080 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5081 (DLLs) on Windows and Windows CE targets.
5083 * GDB now supports a faster verification that a .debug file matches its binary
5084 according to its build-id signature, if the signature is present.
5090 Enable or disable hardware flow control (RTS/CTS) on the serial port
5091 when debugging using remote targets.
5093 set mem inaccessible-by-default
5094 show mem inaccessible-by-default
5095 If the target supplies a memory map, for instance via the remote
5096 protocol's "qXfer:memory-map:read" packet, setting this variable
5097 prevents GDB from accessing memory outside the memory map. This
5098 is useful for targets with memory mapped registers or which react
5099 badly to accesses of unmapped address space.
5101 set breakpoint auto-hw
5102 show breakpoint auto-hw
5103 If the target supplies a memory map, for instance via the remote
5104 protocol's "qXfer:memory-map:read" packet, setting this variable
5105 lets GDB use hardware breakpoints automatically for memory regions
5106 where it can not use software breakpoints. This covers both the
5107 "break" command and internal breakpoints used for other commands
5108 including "next" and "finish".
5111 catch exception unhandled
5112 Stop the program execution when Ada exceptions are raised.
5115 Stop the program execution when an Ada assertion failed.
5119 Set an alternate system root for target files. This is a more
5120 general version of "set solib-absolute-prefix", which is now
5121 an alias to "set sysroot".
5124 Provide extended SPU facility status information. This set of
5125 commands is available only when debugging the Cell/B.E. SPU
5128 * New native configurations
5130 OpenBSD/sh sh*-*openbsd*
5133 unset tdesc filename
5135 Use the specified local file as an XML target description, and do
5136 not query the target for its built-in description.
5140 OpenBSD/sh sh*-*-openbsd*
5141 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5142 Toshiba Media Processor mep-elf
5144 * New remote packets
5147 Ignore the specified signals; pass them directly to the debugged program
5148 without stopping other threads or reporting them to GDB.
5150 qXfer:features:read:
5151 Read an XML target description from the target, which describes its
5156 Read or write contents of an spufs file on the target system. These
5157 packets are available only on the Cell/B.E. SPU architecture.
5159 qXfer:libraries:read:
5160 Report the loaded shared libraries. Combined with new "T" packet
5161 response, this packet allows GDB to debug shared libraries on
5162 targets where the operating system manages the list of loaded
5163 libraries (e.g. Windows and SymbianOS).
5167 Support for these obsolete configurations has been removed.
5175 i[34567]86-*-lynxos*
5176 i[34567]86-*-netware*
5177 i[34567]86-*-sco3.2v5*
5178 i[34567]86-*-sco3.2v4*
5180 i[34567]86-*-sysv4.2*
5183 i[34567]86-*-unixware2*
5184 i[34567]86-*-unixware*
5193 * Other removed features
5200 Various m68k-only ROM monitors.
5207 Various Renesas ROM monitors and debugging interfaces for SH and
5212 Support for a Macraigor serial interface to on-chip debugging.
5213 GDB does not directly support the newer parallel or USB
5218 A debug information format. The predecessor to DWARF 2 and
5219 DWARF 3, which are still supported.
5221 Support for the HP aCC compiler on HP-UX/PA-RISC
5223 SOM-encapsulated symbolic debugging information, automatic
5224 invocation of pxdb, and the aCC custom C++ ABI. This does not
5225 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5226 with aCC can still be debugged on an assembly level.
5228 MIPS ".pdr" sections
5230 A MIPS-specific format used to describe stack frame layout
5231 in debugging information.
5235 GDB could work with an older version of Guile to debug
5236 the interpreter and Scheme programs running in it.
5238 set mips stack-arg-size
5239 set mips saved-gpreg-size
5241 Use "set mips abi" to control parameter passing for MIPS.
5243 *** Changes in GDB 6.6
5248 Cell Broadband Engine SPU spu-elf
5250 * GDB can now be configured as a cross-debugger targeting native Windows
5251 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5252 running on a Windows system over TCP/IP to debug Windows programs.
5254 * The GDB remote stub, gdbserver, has been updated to support Windows and
5255 Cygwin debugging. Both single-threaded and multi-threaded programs are
5258 * The "set trust-readonly-sections" command works again. This command was
5259 broken in GDB 6.3, 6.4, and 6.5.
5261 * The "load" command now supports writing to flash memory, if the remote
5262 stub provides the required support.
5264 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5265 longer requires symbolic debug information (e.g. DWARF-2).
5270 unset substitute-path
5271 show substitute-path
5272 Manage a list of substitution rules that GDB uses to rewrite the name
5273 of the directories where the sources are located. This can be useful
5274 for instance when the sources were moved to a different location
5275 between compilation and debugging.
5279 Print each CLI command as it is executed. Each command is prefixed with
5280 a number of `+' symbols representing the nesting depth.
5281 The source command now has a `-v' option to enable the same feature.
5285 The ARM Demon monitor support (RDP protocol, "target rdp").
5287 Kernel Object Display, an embedded debugging feature which only worked with
5288 an obsolete version of Cisco IOS.
5290 The 'set download-write-size' and 'show download-write-size' commands.
5292 * New remote packets
5295 Tell a stub about GDB client features, and request remote target features.
5296 The first feature implemented is PacketSize, which allows the target to
5297 specify the size of packets it can handle - to minimize the number of
5298 packets required and improve performance when connected to a remote
5302 Fetch an OS auxilliary vector from the remote stub. This packet is a
5303 more efficient replacement for qPart:auxv:read.
5305 qXfer:memory-map:read:
5306 Fetch a memory map from the remote stub, including information about
5307 RAM, ROM, and flash memory devices.
5312 Erase and program a flash memory device.
5314 * Removed remote packets
5317 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5318 used it, and only gdbserver implemented it.
5320 *** Changes in GDB 6.5
5324 Renesas M32C/M16C m32c-elf
5326 Morpho Technologies ms1 ms1-elf
5330 init-if-undefined Initialize a convenience variable, but
5331 only if it doesn't already have a value.
5333 The following commands are presently only implemented for native GNU/Linux:
5335 checkpoint Save a snapshot of the program state.
5337 restart <n> Return the program state to a
5338 previously saved state.
5340 info checkpoints List currently saved checkpoints.
5342 delete-checkpoint <n> Delete a previously saved checkpoint.
5344 set|show detach-on-fork Tell gdb whether to detach from a newly
5345 forked process, or to keep debugging it.
5347 info forks List forks of the user program that
5348 are available to be debugged.
5350 fork <n> Switch to debugging one of several
5351 forks of the user program that are
5352 available to be debugged.
5354 delete-fork <n> Delete a fork from the list of forks
5355 that are available to be debugged (and
5356 kill the forked process).
5358 detach-fork <n> Delete a fork from the list of forks
5359 that are available to be debugged (and
5360 allow the process to continue).
5364 Morpho Technologies ms2 ms1-elf
5366 * Improved Windows host support
5368 GDB now builds as a cross debugger hosted on i686-mingw32, including
5369 native console support, and remote communications using either
5370 network sockets or serial ports.
5372 * Improved Modula-2 language support
5374 GDB can now print most types in the Modula-2 syntax. This includes:
5375 basic types, set types, record types, enumerated types, range types,
5376 pointer types and ARRAY types. Procedure var parameters are correctly
5377 printed and hexadecimal addresses and character constants are also
5378 written in the Modula-2 syntax. Best results can be obtained by using
5379 GNU Modula-2 together with the -gdwarf-2 command line option.
5383 The ARM rdi-share module.
5385 The Netware NLM debug server.
5387 *** Changes in GDB 6.4
5389 * New native configurations
5391 OpenBSD/arm arm*-*-openbsd*
5392 OpenBSD/mips64 mips64-*-openbsd*
5396 Morpho Technologies ms1 ms1-elf
5398 * New command line options
5400 --batch-silent As for --batch, but totally silent.
5401 --return-child-result The debugger will exist with the same value
5402 the child (debugged) program exited with.
5403 --eval-command COMMAND, -ex COMMAND
5404 Execute a single GDB CLI command. This may be
5405 specified multiple times and in conjunction
5406 with the --command (-x) option.
5408 * Deprecated commands removed
5410 The following commands, that were deprecated in 2000, have been
5414 set|show arm disassembly-flavor set|show arm disassembler
5415 othernames set arm disassembler
5416 set|show remotedebug set|show debug remote
5417 set|show archdebug set|show debug arch
5418 set|show eventdebug set|show debug event
5421 * New BSD user-level threads support
5423 It is now possible to debug programs using the user-level threads
5424 library on OpenBSD and FreeBSD. Currently supported (target)
5427 FreeBSD/amd64 x86_64-*-freebsd*
5428 FreeBSD/i386 i386-*-freebsd*
5429 OpenBSD/i386 i386-*-openbsd*
5431 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5432 are not yet supported.
5434 * New support for Matsushita MN10300 w/sim added
5435 (Work in progress). mn10300-elf.
5437 * REMOVED configurations and files
5439 VxWorks and the XDR protocol *-*-vxworks
5440 Motorola MCORE mcore-*-*
5441 National Semiconductor NS32000 ns32k-*-*
5443 * New "set print array-indexes" command
5445 After turning this setting "on", GDB prints the index of each element
5446 when displaying arrays. The default is "off" to preserve the previous
5449 * VAX floating point support
5451 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5453 * User-defined command support
5455 In addition to using $arg0..$arg9 for argument passing, it is now possible
5456 to use $argc to determine now many arguments have been passed. See the
5457 section on user-defined commands in the user manual for more information.
5459 *** Changes in GDB 6.3:
5461 * New command line option
5463 GDB now accepts -l followed by a number to set the timeout for remote
5466 * GDB works with GCC -feliminate-dwarf2-dups
5468 GDB now supports a more compact representation of DWARF-2 debug
5469 information using DW_FORM_ref_addr references. These are produced
5470 by GCC with the option -feliminate-dwarf2-dups and also by some
5471 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5472 to use -feliminate-dwarf2-dups.
5474 * Internationalization
5476 When supported by the host system, GDB will be built with
5477 internationalization (libintl). The task of marking up the sources is
5478 continued, we're looking forward to our first translation.
5482 Initial support for debugging programs compiled with the GNAT
5483 implementation of the Ada programming language has been integrated
5484 into GDB. In this release, support is limited to expression evaluation.
5486 * New native configurations
5488 GNU/Linux/m32r m32r-*-linux-gnu
5492 GDB's remote protocol now includes support for the 'p' packet. This
5493 packet is used to fetch individual registers from a remote inferior.
5495 * END-OF-LIFE registers[] compatibility module
5497 GDB's internal register infrastructure has been completely rewritten.
5498 The new infrastructure making possible the implementation of key new
5499 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5502 GDB 6.3 will be the last release to include the registers[]
5503 compatibility module that allowed out-of-date configurations to
5504 continue to work. This change directly impacts the following
5514 powerpc bdm protocol
5516 Unless there is activity to revive these configurations, they will be
5517 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5519 * OBSOLETE configurations and files
5521 Configurations that have been declared obsolete in this release have
5522 been commented out. Unless there is activity to revive these
5523 configurations, the next release of GDB will have their sources
5524 permanently REMOVED.
5533 *** Changes in GDB 6.2.1:
5535 * MIPS `break main; run' gave an heuristic-fence-post warning
5537 When attempting to run even a simple program, a warning about
5538 heuristic-fence-post being hit would be reported. This problem has
5541 * MIPS IRIX 'long double' crashed GDB
5543 When examining a long double variable, GDB would get a segmentation
5544 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5545 IRIX long double values).
5549 A bug in the VAX stack code was causing problems with the "next"
5550 command. This problem has been fixed.
5552 *** Changes in GDB 6.2:
5554 * Fix for ``many threads''
5556 On GNU/Linux systems that use the NPTL threads library, a program
5557 rapidly creating and deleting threads would confuse GDB leading to the
5560 ptrace: No such process.
5561 thread_db_get_info: cannot get thread info: generic error
5563 This problem has been fixed.
5565 * "-async" and "-noasync" options removed.
5567 Support for the broken "-noasync" option has been removed (it caused
5570 * New ``start'' command.
5572 This command runs the program until the beginning of the main procedure.
5574 * New BSD Kernel Data Access Library (libkvm) interface
5576 Using ``target kvm'' it is now possible to debug kernel core dumps and
5577 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5578 platforms. Currently supported (native-only) configurations are:
5580 FreeBSD/amd64 x86_64-*-freebsd*
5581 FreeBSD/i386 i?86-*-freebsd*
5582 NetBSD/i386 i?86-*-netbsd*
5583 NetBSD/m68k m68*-*-netbsd*
5584 NetBSD/sparc sparc-*-netbsd*
5585 OpenBSD/amd64 x86_64-*-openbsd*
5586 OpenBSD/i386 i?86-*-openbsd*
5587 OpenBSD/m68k m68*-openbsd*
5588 OpenBSD/sparc sparc-*-openbsd*
5590 * Signal trampoline code overhauled
5592 Many generic problems with GDB's signal handling code have been fixed.
5593 These include: backtraces through non-contiguous stacks; recognition
5594 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5595 call; backtrace through a signal trampoline; step into and out of
5596 signal handlers; and single-stepping in the signal trampoline.
5598 Please note that kernel bugs are a limiting factor here. These
5599 features have been shown to work on an s390 GNU/Linux system that
5600 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5602 * Cygwin support for DWARF 2 added.
5604 * New native configurations
5606 GNU/Linux/hppa hppa*-*-linux*
5607 OpenBSD/hppa hppa*-*-openbsd*
5608 OpenBSD/m68k m68*-*-openbsd*
5609 OpenBSD/m88k m88*-*-openbsd*
5610 OpenBSD/powerpc powerpc-*-openbsd*
5611 NetBSD/vax vax-*-netbsd*
5612 OpenBSD/vax vax-*-openbsd*
5614 * END-OF-LIFE frame compatibility module
5616 GDB's internal frame infrastructure has been completely rewritten.
5617 The new infrastructure making it possible to support key new features
5618 including DWARF 2 Call Frame Information. To aid in the task of
5619 migrating old configurations to this new infrastructure, a
5620 compatibility module, that allowed old configurations to continue to
5621 work, was also included.
5623 GDB 6.2 will be the last release to include this frame compatibility
5624 module. This change directly impacts the following configurations:
5634 Unless there is activity to revive these configurations, they will be
5635 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5637 * REMOVED configurations and files
5639 Sun 3, running SunOS 3 m68*-*-sunos3*
5640 Sun 3, running SunOS 4 m68*-*-sunos4*
5641 Sun 2, running SunOS 3 m68000-*-sunos3*
5642 Sun 2, running SunOS 4 m68000-*-sunos4*
5643 Motorola 680x0 running LynxOS m68*-*-lynxos*
5644 AT&T 3b1/Unix pc m68*-att-*
5645 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5646 decstation mips-dec-* mips-little-*
5647 riscos mips-*-riscos* mips-*-sysv*
5648 sonymips mips-sony-*
5649 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5651 *** Changes in GDB 6.1.1:
5653 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5655 The TUI (Text-mode User Interface) is now built as part of a default
5656 GDB configuration. It is enabled by either selecting the TUI with the
5657 command line option "-i=tui" or by running the separate "gdbtui"
5658 program. For more information on the TUI, see the manual "Debugging
5661 * Pending breakpoint support (also included in GDB 6.1)
5663 Support has been added to allow you to specify breakpoints in shared
5664 libraries that have not yet been loaded. If a breakpoint location
5665 cannot be found, and the "breakpoint pending" option is set to auto,
5666 GDB queries you if you wish to make the breakpoint pending on a future
5667 shared-library load. If and when GDB resolves the breakpoint symbol,
5668 the pending breakpoint is removed as one or more regular breakpoints
5671 Pending breakpoints are very useful for GCJ Java debugging.
5673 * Fixed ISO-C build problems
5675 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5676 non ISO-C code that stopped them being built using a more strict ISO-C
5677 compiler (e.g., IBM's C compiler).
5679 * Fixed build problem on IRIX 5
5681 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5682 wasn't able to compile compile on an IRIX 5 system.
5684 * Added execute permission to gdb/gdbserver/configure
5686 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5687 permission. This bug would cause configure to fail on a number of
5688 systems (Solaris, IRIX). Ref: server/519.
5690 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5692 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5693 has been updated to use constant array sizes.
5695 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5697 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5698 its generated DWARF Call Frame Info. This encoding was causing GDB to
5699 panic, that panic has been fixed. Ref: gdb/1628.
5701 * Fixed a problem when examining parameters in shared library code.
5703 When examining parameters in optimized shared library code generated
5704 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5705 not available''. GDB now correctly displays the variable's value.
5707 *** Changes in GDB 6.1:
5709 * Removed --with-mmalloc
5711 Support for the mmalloc memory manager has been removed, as it
5712 conflicted with the internal gdb byte cache.
5714 * Changes in AMD64 configurations
5716 The AMD64 target now includes the %cs and %ss registers. As a result
5717 the AMD64 remote protocol has changed; this affects the floating-point
5718 and SSE registers. If you rely on those registers for your debugging,
5719 you should upgrade gdbserver on the remote side.
5721 * Revised SPARC target
5723 The SPARC target has been completely revised, incorporating the
5724 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5725 support for LynxOS and SunOS 4 has been dropped. Calling functions
5726 from within GDB on operating systems with a non-executable stack
5727 (Solaris, OpenBSD) now works.
5731 GDB has a new C++ demangler which does a better job on the mangled
5732 names generated by current versions of g++. It also runs faster, so
5733 with this and other changes gdb should now start faster on large C++
5736 * DWARF 2 Location Expressions
5738 GDB support for location expressions has been extended to support function
5739 arguments and frame bases. Older versions of GDB could crash when they
5742 * C++ nested types and namespaces
5744 GDB's support for nested types and namespaces in C++ has been
5745 improved, especially if you use the DWARF 2 debugging format. (This
5746 is the default for recent versions of GCC on most platforms.)
5747 Specifically, if you have a class "Inner" defined within a class or
5748 namespace "Outer", then GDB realizes that the class's name is
5749 "Outer::Inner", not simply "Inner". This should greatly reduce the
5750 frequency of complaints about not finding RTTI symbols. In addition,
5751 if you are stopped at inside of a function defined within a namespace,
5752 GDB modifies its name lookup accordingly.
5754 * New native configurations
5756 NetBSD/amd64 x86_64-*-netbsd*
5757 OpenBSD/amd64 x86_64-*-openbsd*
5758 OpenBSD/alpha alpha*-*-openbsd*
5759 OpenBSD/sparc sparc-*-openbsd*
5760 OpenBSD/sparc64 sparc64-*-openbsd*
5762 * New debugging protocols
5764 M32R with SDI protocol m32r-*-elf*
5766 * "set prompt-escape-char" command deleted.
5768 The command "set prompt-escape-char" has been deleted. This command,
5769 and its very obscure effect on GDB's prompt, was never documented,
5770 tested, nor mentioned in the NEWS file.
5772 * OBSOLETE configurations and files
5774 Configurations that have been declared obsolete in this release have
5775 been commented out. Unless there is activity to revive these
5776 configurations, the next release of GDB will have their sources
5777 permanently REMOVED.
5779 Sun 3, running SunOS 3 m68*-*-sunos3*
5780 Sun 3, running SunOS 4 m68*-*-sunos4*
5781 Sun 2, running SunOS 3 m68000-*-sunos3*
5782 Sun 2, running SunOS 4 m68000-*-sunos4*
5783 Motorola 680x0 running LynxOS m68*-*-lynxos*
5784 AT&T 3b1/Unix pc m68*-att-*
5785 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5786 decstation mips-dec-* mips-little-*
5787 riscos mips-*-riscos* mips-*-sysv*
5788 sonymips mips-sony-*
5789 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5791 * REMOVED configurations and files
5793 SGI Irix-4.x mips-sgi-irix4 or iris4
5794 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5795 Z8000 simulator z8k-zilog-none or z8ksim
5796 Matsushita MN10200 w/simulator mn10200-*-*
5797 H8/500 simulator h8500-hitachi-hms or h8500hms
5798 HP/PA running BSD hppa*-*-bsd*
5799 HP/PA running OSF/1 hppa*-*-osf*
5800 HP/PA Pro target hppa*-*-pro*
5801 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5802 386BSD i[3456]86-*-bsd*
5803 Sequent family i[3456]86-sequent-sysv4*
5804 i[3456]86-sequent-sysv*
5805 i[3456]86-sequent-bsd*
5806 SPARC running LynxOS sparc-*-lynxos*
5807 SPARC running SunOS 4 sparc-*-sunos4*
5808 Tsqware Sparclet sparclet-*-*
5809 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5811 *** Changes in GDB 6.0:
5815 Support for debugging the Objective-C programming language has been
5816 integrated into GDB.
5818 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5820 DWARF 2's Call Frame Information makes available compiler generated
5821 information that more exactly describes the program's run-time stack.
5822 By using this information, GDB is able to provide more robust stack
5825 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5826 have been updated to use a new backtrace mechanism which includes
5827 DWARF 2 CFI support.
5831 GDB's remote protocol has been extended to include support for hosted
5832 file I/O (where the remote target uses GDB's file system). See GDB's
5833 remote protocol documentation for details.
5835 * All targets using the new architecture framework.
5837 All of GDB's targets have been updated to use the new internal
5838 architecture framework. The way is now open for future GDB releases
5839 to include cross-architecture native debugging support (i386 on amd64,
5842 * GNU/Linux's Thread Local Storage (TLS)
5844 GDB now includes support for for the GNU/Linux implementation of
5845 per-thread variables.
5847 * GNU/Linux's Native POSIX Thread Library (NPTL)
5849 GDB's thread code has been updated to work with either the new
5850 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5852 * Separate debug info.
5854 GDB, in conjunction with BINUTILS, now supports a mechanism for
5855 automatically loading debug information from a separate file. Instead
5856 of shipping full debug and non-debug versions of system libraries,
5857 system integrators can now instead ship just the stripped libraries
5858 and optional debug files.
5860 * DWARF 2 Location Expressions
5862 DWARF 2 Location Expressions allow the compiler to more completely
5863 describe the location of variables (even in optimized code) to the
5866 GDB now includes preliminary support for location expressions (support
5867 for DW_OP_piece is still missing).
5871 A number of long standing bugs that caused GDB to die while starting a
5872 Java application have been fixed. GDB's Java support is now
5873 considered "useable".
5875 * GNU/Linux support for fork, vfork, and exec.
5877 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5878 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5881 * GDB supports logging output to a file
5883 There are two new commands, "set logging" and "show logging", which can be
5884 used to capture GDB's output to a file.
5886 * The meaning of "detach" has changed for gdbserver
5888 The "detach" command will now resume the application, as documented. To
5889 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5892 * d10v, m68hc11 `regs' command deprecated
5894 The `info registers' command has been updated so that it displays the
5895 registers using a format identical to the old `regs' command.
5899 A new command, "maint set profile on/off", has been added. This command can
5900 be used to enable or disable profiling while running GDB, to profile a
5901 session or a set of commands. In addition there is a new configure switch,
5902 "--enable-profiling", which will cause GDB to be compiled with profiling
5903 data, for more informative profiling results.
5905 * Default MI syntax changed to "mi2".
5907 The default MI (machine interface) syntax, enabled by the command line
5908 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5909 "mi1", can be enabled by specifying the option "-i=mi1".
5911 Support for the original "mi0" syntax (included in GDB 5.0) has been
5914 Fix for gdb/192: removed extraneous space when displaying frame level.
5915 Fix for gdb/672: update changelist is now output in mi list format.
5916 Fix for gdb/702: a -var-assign that updates the value now shows up
5917 in a subsequent -var-update.
5919 * New native configurations.
5921 FreeBSD/amd64 x86_64-*-freebsd*
5923 * Multi-arched targets.
5925 HP/PA HPUX11 hppa*-*-hpux*
5926 Renesas M32R/D w/simulator m32r-*-elf*
5928 * OBSOLETE configurations and files
5930 Configurations that have been declared obsolete in this release have
5931 been commented out. Unless there is activity to revive these
5932 configurations, the next release of GDB will have their sources
5933 permanently REMOVED.
5935 Z8000 simulator z8k-zilog-none or z8ksim
5936 Matsushita MN10200 w/simulator mn10200-*-*
5937 H8/500 simulator h8500-hitachi-hms or h8500hms
5938 HP/PA running BSD hppa*-*-bsd*
5939 HP/PA running OSF/1 hppa*-*-osf*
5940 HP/PA Pro target hppa*-*-pro*
5941 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5942 Sequent family i[3456]86-sequent-sysv4*
5943 i[3456]86-sequent-sysv*
5944 i[3456]86-sequent-bsd*
5945 Tsqware Sparclet sparclet-*-*
5946 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5948 * REMOVED configurations and files
5951 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5952 IBM AIX PS/2 i[3456]86-*-aix
5953 i386 running Mach 3.0 i[3456]86-*-mach3*
5954 i386 running Mach i[3456]86-*-mach*
5955 i386 running OSF/1 i[3456]86-*osf1mk*
5956 HP/Apollo 68k Family m68*-apollo*-sysv*,
5958 m68*-hp-bsd*, m68*-hp-hpux*
5959 Argonaut Risc Chip (ARC) arc-*-*
5960 Mitsubishi D30V d30v-*-*
5961 Fujitsu FR30 fr30-*-elf*
5962 OS/9000 i[34]86-*-os9k
5963 I960 with MON960 i960-*-coff
5965 * MIPS $fp behavior changed
5967 The convenience variable $fp, for the MIPS, now consistently returns
5968 the address of the current frame's base. Previously, depending on the
5969 context, $fp could refer to either $sp or the current frame's base
5970 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5971 The GNU Source-Level Debugger''.
5973 *** Changes in GDB 5.3:
5975 * GNU/Linux shared library multi-threaded performance improved.
5977 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5978 `/proc', in preference to `ptrace' for memory reads. This may result
5979 in an improvement in the start-up time of multi-threaded, shared
5980 library applications when run under GDB. One GDB user writes: ``loads
5981 shared libs like mad''.
5983 * ``gdbserver'' now supports multi-threaded applications on some targets
5985 Support for debugging multi-threaded applications which use
5986 the GNU/Linux LinuxThreads package has been added for
5987 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5988 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5990 * GDB now supports C/C++ preprocessor macros.
5992 GDB now expands preprocessor macro invocations in C/C++ expressions,
5993 and provides various commands for showing macro definitions and how
5996 The new command `macro expand EXPRESSION' expands any macro
5997 invocations in expression, and shows the result.
5999 The new command `show macro MACRO-NAME' shows the definition of the
6000 macro named MACRO-NAME, and where it was defined.
6002 Most compilers don't include information about macros in the debugging
6003 information by default. In GCC 3.1, for example, you need to compile
6004 your program with the options `-gdwarf-2 -g3'. If the macro
6005 information is present in the executable, GDB will read it.
6007 * Multi-arched targets.
6009 DEC Alpha (partial) alpha*-*-*
6010 DEC VAX (partial) vax-*-*
6012 National Semiconductor NS32000 (partial) ns32k-*-*
6013 Motorola 68000 (partial) m68k-*-*
6014 Motorola MCORE mcore-*-*
6018 Fujitsu FRV architecture added by Red Hat frv*-*-*
6021 * New native configurations
6023 Alpha NetBSD alpha*-*-netbsd*
6024 SH NetBSD sh*-*-netbsdelf*
6025 MIPS NetBSD mips*-*-netbsd*
6026 UltraSPARC NetBSD sparc64-*-netbsd*
6028 * OBSOLETE configurations and files
6030 Configurations that have been declared obsolete in this release have
6031 been commented out. Unless there is activity to revive these
6032 configurations, the next release of GDB will have their sources
6033 permanently REMOVED.
6035 Mitsubishi D30V d30v-*-*
6036 OS/9000 i[34]86-*-os9k
6037 IBM AIX PS/2 i[3456]86-*-aix
6038 Fujitsu FR30 fr30-*-elf*
6039 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6040 Argonaut Risc Chip (ARC) arc-*-*
6041 i386 running Mach 3.0 i[3456]86-*-mach3*
6042 i386 running Mach i[3456]86-*-mach*
6043 i386 running OSF/1 i[3456]86-*osf1mk*
6044 HP/Apollo 68k Family m68*-apollo*-sysv*,
6046 m68*-hp-bsd*, m68*-hp-hpux*
6047 I960 with MON960 i960-*-coff
6049 * OBSOLETE languages
6051 CHILL, a Pascal like language used by telecommunications companies.
6053 * REMOVED configurations and files
6055 AMD 29k family via UDI a29k-amd-udi, udi29k
6056 A29K VxWorks a29k-*-vxworks
6057 AMD 29000 embedded, using EBMON a29k-none-none
6058 AMD 29000 embedded with COFF a29k-none-coff
6059 AMD 29000 embedded with a.out a29k-none-aout
6061 testsuite/gdb.hp/gdb.threads-hp/ directory
6063 * New command "set max-user-call-depth <nnn>"
6065 This command allows the user to limit the call depth of user-defined
6066 commands. The default is 1024.
6068 * Changes in FreeBSD/i386 native debugging.
6070 Support for the "generate-core-file" has been added.
6072 * New commands "dump", "append", and "restore".
6074 These commands allow data to be copied from target memory
6075 to a bfd-format or binary file (dump and append), and back
6076 from a file into memory (restore).
6078 * Improved "next/step" support on multi-processor Alpha Tru64.
6080 The previous single-step mechanism could cause unpredictable problems,
6081 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6082 of a software single-step mechanism prevents this.
6084 *** Changes in GDB 5.2.1:
6092 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6093 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6094 Fix, by Joel Brobecker imported from mainline.
6096 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6097 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6098 Fix, by Fred Fish, imported from mainline.
6100 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6101 Surprisingly enough, it works now.
6102 By Michal Ludvig, imported from mainline.
6104 i386 hardware watchpoint support:
6105 avoid misses on second run for some targets.
6106 By Pierre Muller, imported from mainline.
6108 *** Changes in GDB 5.2:
6110 * New command "set trust-readonly-sections on[off]".
6112 This command is a hint that tells gdb that read-only sections
6113 really are read-only (ie. that their contents will not change).
6114 In this mode, gdb will go to the object file rather than the
6115 target to read memory from read-only sections (such as ".text").
6116 This can be a significant performance improvement on some
6117 (notably embedded) targets.
6119 * New command "generate-core-file" (or "gcore").
6121 This new gdb command allows the user to drop a core file of the child
6122 process state at any time. So far it's been implemented only for
6123 GNU/Linux and Solaris, but should be relatively easily ported to other
6124 hosts. Argument is core file name (defaults to core.<pid>).
6126 * New command line option
6128 GDB now accepts --pid or -p followed by a process id.
6130 * Change in command line behavior -- corefiles vs. process ids.
6132 There is a subtle behavior in the way in which GDB handles
6133 command line arguments. The first non-flag argument is always
6134 a program to debug, but the second non-flag argument may either
6135 be a corefile or a process id. Previously, GDB would attempt to
6136 open the second argument as a corefile, and if that failed, would
6137 issue a superfluous error message and then attempt to attach it as
6138 a process. Now, if the second argument begins with a non-digit,
6139 it will be treated as a corefile. If it begins with a digit,
6140 GDB will attempt to attach it as a process, and if no such process
6141 is found, will then attempt to open it as a corefile.
6143 * Changes in ARM configurations.
6145 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6146 configuration is fully multi-arch.
6148 * New native configurations
6150 ARM NetBSD arm*-*-netbsd*
6151 x86 OpenBSD i[3456]86-*-openbsd*
6152 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6153 Sparc64 running FreeBSD sparc64-*-freebsd*
6157 Sanyo XStormy16 xstormy16-elf
6159 * OBSOLETE configurations and files
6161 Configurations that have been declared obsolete in this release have
6162 been commented out. Unless there is activity to revive these
6163 configurations, the next release of GDB will have their sources
6164 permanently REMOVED.
6166 AMD 29k family via UDI a29k-amd-udi, udi29k
6167 A29K VxWorks a29k-*-vxworks
6168 AMD 29000 embedded, using EBMON a29k-none-none
6169 AMD 29000 embedded with COFF a29k-none-coff
6170 AMD 29000 embedded with a.out a29k-none-aout
6172 testsuite/gdb.hp/gdb.threads-hp/ directory
6174 * REMOVED configurations and files
6176 TI TMS320C80 tic80-*-*
6178 PowerPC Solaris powerpcle-*-solaris*
6179 PowerPC Windows NT powerpcle-*-cygwin32
6180 PowerPC Netware powerpc-*-netware*
6181 Harris/CXUX m88k m88*-harris-cxux*
6182 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6183 ns32k-utek-sysv* ns32k-utek-*
6184 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6185 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6186 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6187 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6188 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6190 * Changes to command line processing
6192 The new `--args' feature can be used to specify command-line arguments
6193 for the inferior from gdb's command line.
6195 * Changes to key bindings
6197 There is a new `operate-and-get-next' function bound to `C-o'.
6199 *** Changes in GDB 5.1.1
6201 Fix compile problem on DJGPP.
6203 Fix a problem with floating-point registers on the i386 being
6206 Fix to stop GDB crashing on .debug_str debug info.
6208 Numerous documentation fixes.
6210 Numerous testsuite fixes.
6212 *** Changes in GDB 5.1:
6214 * New native configurations
6216 Alpha FreeBSD alpha*-*-freebsd*
6217 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6218 MIPS GNU/Linux mips*-*-linux*
6219 MIPS SGI Irix 6.x mips*-sgi-irix6*
6220 ia64 AIX ia64-*-aix*
6221 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6225 Motorola 68HC11 and 68HC12 m68hc11-elf
6227 UltraSparc running GNU/Linux sparc64-*-linux*
6229 * OBSOLETE configurations and files
6231 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6232 Harris/CXUX m88k m88*-harris-cxux*
6233 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6234 ns32k-utek-sysv* ns32k-utek-*
6235 TI TMS320C80 tic80-*-*
6237 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6238 PowerPC Solaris powerpcle-*-solaris*
6239 PowerPC Windows NT powerpcle-*-cygwin32
6240 PowerPC Netware powerpc-*-netware*
6241 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6242 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6243 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6244 Apple Macintosh (MPW) host N/A
6246 stuff.c (Program to stuff files into a specially prepared space in kdb)
6247 kdb-start.c (Main loop for the standalone kernel debugger)
6249 Configurations that have been declared obsolete in this release have
6250 been commented out. Unless there is activity to revive these
6251 configurations, the next release of GDB will have their sources
6252 permanently REMOVED.
6254 * REMOVED configurations and files
6256 Altos 3068 m68*-altos-*
6257 Convex c1-*-*, c2-*-*
6259 ARM RISCix arm-*-* (as host)
6263 * GDB has been converted to ISO C.
6265 GDB's source code has been converted to ISO C. In particular, the
6266 sources are fully protoized, and rely on standard headers being
6271 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6273 * The MI enabled by default.
6275 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6276 revised and enabled by default. Packages which use GDB as a debugging
6277 engine behind a UI or another front end are encouraged to switch to
6278 using the GDB/MI interface, instead of the old annotations interface
6279 which is now deprecated.
6281 * Support for debugging Pascal programs.
6283 GDB now includes support for debugging Pascal programs. The following
6284 main features are supported:
6286 - Pascal-specific data types such as sets;
6288 - automatic recognition of Pascal sources based on file-name
6291 - Pascal-style display of data types, variables, and functions;
6293 - a Pascal expression parser.
6295 However, some important features are not yet supported.
6297 - Pascal string operations are not supported at all;
6299 - there are some problems with boolean types;
6301 - Pascal type hexadecimal constants are not supported
6302 because they conflict with the internal variables format;
6304 - support for Pascal objects and classes is not full yet;
6306 - unlike Pascal, GDB is case-sensitive for symbol names.
6308 * Changes in completion.
6310 Commands such as `shell', `run' and `set args', which pass arguments
6311 to inferior programs, now complete on file names, similar to what
6312 users expect at the shell prompt.
6314 Commands which accept locations, such as `disassemble', `print',
6315 `breakpoint', `until', etc. now complete on filenames as well as
6316 program symbols. Thus, if you type "break foob TAB", and the source
6317 files linked into the programs include `foobar.c', that file name will
6318 be one of the candidates for completion. However, file names are not
6319 considered for completion after you typed a colon that delimits a file
6320 name from a name of a function in that file, as in "break foo.c:bar".
6322 `set demangle-style' completes on available demangling styles.
6324 * New platform-independent commands:
6326 It is now possible to define a post-hook for a command as well as a
6327 hook that runs before the command. For more details, see the
6328 documentation of `hookpost' in the GDB manual.
6330 * Changes in GNU/Linux native debugging.
6332 Support for debugging multi-threaded programs has been completely
6333 revised for all platforms except m68k and sparc. You can now debug as
6334 many threads as your system allows you to have.
6336 Attach/detach is supported for multi-threaded programs.
6338 Support for SSE registers was added for x86. This doesn't work for
6339 multi-threaded programs though.
6341 * Changes in MIPS configurations.
6343 Multi-arch support is enabled for all MIPS configurations.
6345 GDB can now be built as native debugger on SGI Irix 6.x systems for
6346 debugging n32 executables. (Debugging 64-bit executables is not yet
6349 * Unified support for hardware watchpoints in all x86 configurations.
6351 Most (if not all) native x86 configurations support hardware-assisted
6352 breakpoints and watchpoints in a unified manner. This support
6353 implements debug register sharing between watchpoints, which allows to
6354 put a virtually infinite number of watchpoints on the same address,
6355 and also supports watching regions up to 16 bytes with several debug
6358 The new maintenance command `maintenance show-debug-regs' toggles
6359 debugging print-outs in functions that insert, remove, and test
6360 watchpoints and hardware breakpoints.
6362 * Changes in the DJGPP native configuration.
6364 New command ``info dos sysinfo'' displays assorted information about
6365 the CPU, OS, memory, and DPMI server.
6367 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6368 display information about segment descriptors stored in GDT, LDT, and
6371 New commands ``info dos pde'' and ``info dos pte'' display entries
6372 from Page Directory and Page Tables (for now works with CWSDPMI only).
6373 New command ``info dos address-pte'' displays the Page Table entry for
6374 a given linear address.
6376 GDB can now pass command lines longer than 126 characters to the
6377 program being debugged (requires an update to the libdbg.a library
6378 which is part of the DJGPP development kit).
6380 DWARF2 debug info is now supported.
6382 It is now possible to `step' and `next' through calls to `longjmp'.
6384 * Changes in documentation.
6386 All GDB documentation was converted to GFDL, the GNU Free
6387 Documentation License.
6389 Tracepoints-related commands are now fully documented in the GDB
6392 TUI, the Text-mode User Interface, is now documented in the manual.
6394 Tracepoints-related commands are now fully documented in the GDB
6397 The "GDB Internals" manual now has an index. It also includes
6398 documentation of `ui_out' functions, GDB coding standards, x86
6399 hardware watchpoints, and memory region attributes.
6401 * GDB's version number moved to ``version.in''
6403 The Makefile variable VERSION has been replaced by the file
6404 ``version.in''. People creating GDB distributions should update the
6405 contents of this file.
6409 GUD support is now a standard part of the EMACS distribution.
6411 *** Changes in GDB 5.0:
6413 * Improved support for debugging FP programs on x86 targets
6415 Unified and much-improved support for debugging floating-point
6416 programs on all x86 targets. In particular, ``info float'' now
6417 displays the FP registers in the same format on all x86 targets, with
6418 greater level of detail.
6420 * Improvements and bugfixes in hardware-assisted watchpoints
6422 It is now possible to watch array elements, struct members, and
6423 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6424 on x86 targets no longer erroneously trigger when the address is
6427 * Improvements in the native DJGPP version of GDB
6429 The distribution now includes all the scripts and auxiliary files
6430 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6431 machines ``out of the box''.
6433 The DJGPP version can now debug programs that use signals. It is
6434 possible to catch signals that happened in the debuggee, deliver
6435 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6436 would kill the program being debugged.) Programs that hook hardware
6437 interrupts (keyboard, timer, etc.) can also be debugged.
6439 It is now possible to debug DJGPP programs that redirect their
6440 standard handles or switch them to raw (as opposed to cooked) mode, or
6441 even close them. The command ``run < foo > bar'' works as expected,
6442 and ``info terminal'' reports useful information about the debuggee's
6443 terminal, including raw/cooked mode, redirection, etc.
6445 The DJGPP version now uses termios functions for console I/O, which
6446 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6449 DOS-style file names with drive letters are now fully supported by
6452 It is now possible to debug DJGPP programs that switch their working
6453 directory. It is also possible to rerun the debuggee any number of
6454 times without restarting GDB; thus, you can use the same setup,
6455 breakpoints, etc. for many debugging sessions.
6457 * New native configurations
6459 ARM GNU/Linux arm*-*-linux*
6460 PowerPC GNU/Linux powerpc-*-linux*
6464 Motorola MCore mcore-*-*
6465 x86 VxWorks i[3456]86-*-vxworks*
6466 PowerPC VxWorks powerpc-*-vxworks*
6467 TI TMS320C80 tic80-*-*
6469 * OBSOLETE configurations
6471 Altos 3068 m68*-altos-*
6472 Convex c1-*-*, c2-*-*
6474 ARM RISCix arm-*-* (as host)
6477 Configurations that have been declared obsolete will be commented out,
6478 but the code will be left in place. If there is no activity to revive
6479 these configurations before the next release of GDB, the sources will
6480 be permanently REMOVED.
6482 * Gould support removed
6484 Support for the Gould PowerNode and NP1 has been removed.
6486 * New features for SVR4
6488 On SVR4 native platforms (such as Solaris), if you attach to a process
6489 without first loading a symbol file, GDB will now attempt to locate and
6490 load symbols from the running process's executable file.
6492 * Many C++ enhancements
6494 C++ support has been greatly improved. Overload resolution now works properly
6495 in almost all cases. RTTI support is on the way.
6497 * Remote targets can connect to a sub-program
6499 A popen(3) style serial-device has been added. This device starts a
6500 sub-process (such as a stand-alone simulator) and then communicates
6501 with that. The sub-program to run is specified using the syntax
6502 ``|<program> <args>'' vis:
6504 (gdb) set remotedebug 1
6505 (gdb) target extended-remote |mn10300-elf-sim program-args
6507 * MIPS 64 remote protocol
6509 A long standing bug in the mips64 remote protocol where by GDB
6510 expected certain 32 bit registers (ex SR) to be transfered as 32
6511 instead of 64 bits has been fixed.
6513 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6514 added to provide backward compatibility with older versions of GDB.
6516 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6518 The command ``set remotebinarydownload'' command has been replaced by
6519 ``set remote X-packet''. Other commands in ``set remote'' family
6520 include ``set remote P-packet''.
6522 * Breakpoint commands accept ranges.
6524 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6525 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6526 ``tracepoint passcount'' also accepts a range of tracepoints.
6528 * ``apropos'' command added.
6530 The ``apropos'' command searches through command names and
6531 documentation strings, printing out matches, making it much easier to
6532 try to find a command that does what you are looking for.
6536 A new machine oriented interface (MI) has been added to GDB. This
6537 interface is designed for debug environments running GDB as a separate
6538 process. This is part of the long term libGDB project. See the
6539 "GDB/MI" chapter of the GDB manual for further information. It can be
6540 enabled by configuring with:
6542 .../configure --enable-gdbmi
6544 *** Changes in GDB-4.18:
6546 * New native configurations
6548 HP-UX 10.20 hppa*-*-hpux10.20
6549 HP-UX 11.x hppa*-*-hpux11.0*
6550 M68K GNU/Linux m68*-*-linux*
6554 Fujitsu FR30 fr30-*-elf*
6555 Intel StrongARM strongarm-*-*
6556 Mitsubishi D30V d30v-*-*
6558 * OBSOLETE configurations
6560 Gould PowerNode, NP1 np1-*-*, pn-*-*
6562 Configurations that have been declared obsolete will be commented out,
6563 but the code will be left in place. If there is no activity to revive
6564 these configurations before the next release of GDB, the sources will
6565 be permanently REMOVED.
6569 As a compatibility experiment, GDB's source files buildsym.h and
6570 buildsym.c have been converted to pure standard C, no longer
6571 containing any K&R compatibility code. We believe that all systems in
6572 use today either come with a standard C compiler, or have a GCC port
6573 available. If this is not true, please report the affected
6574 configuration to bug-gdb@gnu.org immediately. See the README file for
6575 information about getting a standard C compiler if you don't have one
6580 GDB now uses readline 2.2.
6582 * set extension-language
6584 You can now control the mapping between filename extensions and source
6585 languages by using the `set extension-language' command. For instance,
6586 you can ask GDB to treat .c files as C++ by saying
6587 set extension-language .c c++
6588 The command `info extensions' lists all of the recognized extensions
6589 and their associated languages.
6591 * Setting processor type for PowerPC and RS/6000
6593 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6594 you can use the `set processor' command to specify what variant of the
6595 PowerPC family you are debugging. The command
6599 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6600 following PowerPC and RS6000 variants:
6602 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6603 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6605 403GC IBM PowerPC 403GC
6606 505 Motorola PowerPC 505
6607 860 Motorola PowerPC 860 or 850
6608 601 Motorola PowerPC 601
6609 602 Motorola PowerPC 602
6610 603 Motorola/IBM PowerPC 603 or 603e
6611 604 Motorola PowerPC 604 or 604e
6612 750 Motorola/IBM PowerPC 750 or 750
6614 At the moment, this command just tells GDB what to name the
6615 special-purpose processor registers. Since almost all the affected
6616 registers are inaccessible to user-level programs, this command is
6617 only useful for remote debugging in its present form.
6621 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6622 more extensive support for HP-UX. Added features include shared
6623 library support, kernel threads and hardware watchpoints for 11.00,
6624 support for HP's ANSI C and C++ compilers, and a compatibility mode
6625 for xdb and dbx commands.
6629 HP's donation includes the new concept of catchpoints, which is a
6630 generalization of the old catch command. On HP-UX, it is now possible
6631 to catch exec, fork, and vfork, as well as library loading.
6633 This means that the existing catch command has changed; its first
6634 argument now specifies the type of catch to be set up. See the
6635 output of "help catch" for a list of catchpoint types.
6637 * Debugging across forks
6639 On HP-UX, you can choose which process to debug when a fork() happens
6644 HP has donated a curses-based terminal user interface (TUI). To get
6645 it, build with --enable-tui. Although this can be enabled for any
6646 configuration, at present it only works for native HP debugging.
6648 * GDB remote protocol additions
6650 A new protocol packet 'X' that writes binary data is now available.
6651 Default behavior is to try 'X', then drop back to 'M' if the stub
6652 fails to respond. The settable variable `remotebinarydownload'
6653 allows explicit control over the use of 'X'.
6655 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6656 full 64-bit address. The command
6658 set remoteaddresssize 32
6660 can be used to revert to the old behaviour. For existing remote stubs
6661 the change should not be noticed, as the additional address information
6664 In order to assist in debugging stubs, you may use the maintenance
6665 command `packet' to send any text string to the stub. For instance,
6667 maint packet heythere
6669 sends the packet "$heythere#<checksum>". Note that it is very easy to
6670 disrupt a debugging session by sending the wrong packet at the wrong
6673 The compare-sections command allows you to compare section data on the
6674 target to what is in the executable file without uploading or
6675 downloading, by comparing CRC checksums.
6677 * Tracing can collect general expressions
6679 You may now collect general expressions at tracepoints. This requires
6680 further additions to the target-side stub; see tracepoint.c and
6681 doc/agentexpr.texi for further details.
6683 * mask-address variable for Mips
6685 For Mips targets, you may control the zeroing of the upper 32 bits of
6686 a 64-bit address by entering `set mask-address on'. This is mainly
6687 of interest to users of embedded R4xxx and R5xxx processors.
6689 * Higher serial baud rates
6691 GDB's serial code now allows you to specify baud rates 57600, 115200,
6692 230400, and 460800 baud. (Note that your host system may not be able
6693 to achieve all of these rates.)
6697 The i960 configuration now includes an initial implementation of a
6698 builtin simulator, contributed by Jim Wilson.
6701 *** Changes in GDB-4.17:
6703 * New native configurations
6705 Alpha GNU/Linux alpha*-*-linux*
6706 Unixware 2.x i[3456]86-unixware2*
6707 Irix 6.x mips*-sgi-irix6*
6708 PowerPC GNU/Linux powerpc-*-linux*
6709 PowerPC Solaris powerpcle-*-solaris*
6710 Sparc GNU/Linux sparc-*-linux*
6711 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6715 Argonaut Risc Chip (ARC) arc-*-*
6716 Hitachi H8/300S h8300*-*-*
6717 Matsushita MN10200 w/simulator mn10200-*-*
6718 Matsushita MN10300 w/simulator mn10300-*-*
6719 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6720 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6721 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6722 Mitsubishi D10V w/simulator d10v-*-*
6723 Mitsubishi M32R/D w/simulator m32r-*-elf*
6724 Tsqware Sparclet sparclet-*-*
6725 NEC V850 w/simulator v850-*-*
6727 * New debugging protocols
6729 ARM with RDI protocol arm*-*-*
6730 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6731 DDB and LSI variants of PMON protocol mips*-*-*
6732 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6733 PowerPC with SDS protocol powerpc{,le}-*-eabi
6734 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6738 All configurations can now understand and use the DWARF 2 debugging
6739 format. The choice is automatic, if the symbol file contains DWARF 2
6744 GDB now includes basic Java language support. This support is
6745 only useful with Java compilers that produce native machine code.
6747 * solib-absolute-prefix and solib-search-path
6749 For SunOS and SVR4 shared libraries, you may now set the prefix for
6750 loading absolute shared library symbol files, and the search path for
6751 locating non-absolute shared library symbol files.
6753 * Live range splitting
6755 GDB can now effectively debug code for which GCC has performed live
6756 range splitting as part of its optimization. See gdb/doc/LRS for
6757 more details on the expected format of the stabs information.
6761 GDB's support for the GNU Hurd, including thread debugging, has been
6762 updated to work with current versions of the Hurd.
6766 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6767 instruction set. ARM GDB automatically detects when Thumb
6768 instructions are in use, and adjusts disassembly and backtracing
6773 GDB's MIPS target configurations now handle the MIP16 16-bit
6778 GDB now includes support for overlays; if an executable has been
6779 linked such that multiple sections are based at the same address, GDB
6780 will decide which section to use for symbolic info. You can choose to
6781 control the decision manually, using overlay commands, or implement
6782 additional target-side support and use "overlay load-target" to bring
6783 in the overlay mapping. Do "help overlay" for more detail.
6787 The command "info symbol <address>" displays information about
6788 the symbol at the specified address.
6792 The standard remote protocol now includes an extension that allows
6793 asynchronous collection and display of trace data. This requires
6794 extensive support in the target-side debugging stub. Tracing mode
6795 includes a new interaction mode in GDB and new commands: see the
6796 file tracepoint.c for more details.
6800 Configurations for embedded MIPS now include a simulator contributed
6801 by Cygnus Solutions. The simulator supports the instruction sets
6802 of most MIPS variants.
6806 Sparc configurations may now include the ERC32 simulator contributed
6807 by the European Space Agency. The simulator is not built into
6808 Sparc targets by default; configure with --enable-sim to include it.
6812 For target configurations that may include multiple variants of a
6813 basic architecture (such as MIPS and SH), you may now set the
6814 architecture explicitly. "set arch" sets, "info arch" lists
6815 the possible architectures.
6817 *** Changes in GDB-4.16:
6819 * New native configurations
6821 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6822 M68K NetBSD m68k-*-netbsd*
6823 PowerPC AIX 4.x powerpc-*-aix*
6824 PowerPC MacOS powerpc-*-macos*
6825 PowerPC Windows NT powerpcle-*-cygwin32
6826 RS/6000 AIX 4.x rs6000-*-aix4*
6830 ARM with RDP protocol arm-*-*
6831 I960 with MON960 i960-*-coff
6832 MIPS VxWorks mips*-*-vxworks*
6833 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6834 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6836 Matra Sparclet sparclet-*-*
6840 The powerpc-eabi configuration now includes the PSIM simulator,
6841 contributed by Andrew Cagney, with assistance from Mike Meissner.
6842 PSIM is a very elaborate model of the PowerPC, including not only
6843 basic instruction set execution, but also details of execution unit
6844 performance and I/O hardware. See sim/ppc/README for more details.
6848 GDB now works with Solaris 2.5.
6850 * Windows 95/NT native
6852 GDB will now work as a native debugger on Windows 95 and Windows NT.
6853 To build it from source, you must use the "gnu-win32" environment,
6854 which uses a DLL to emulate enough of Unix to run the GNU tools.
6855 Further information, binaries, and sources are available at
6856 ftp.cygnus.com, under pub/gnu-win32.
6858 * dont-repeat command
6860 If a user-defined command includes the command `dont-repeat', then the
6861 command will not be repeated if the user just types return. This is
6862 useful if the command is time-consuming to run, so that accidental
6863 extra keystrokes don't run the same command many times.
6865 * Send break instead of ^C
6867 The standard remote protocol now includes an option to send a break
6868 rather than a ^C to the target in order to interrupt it. By default,
6869 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6871 * Remote protocol timeout
6873 The standard remote protocol includes a new variable `remotetimeout'
6874 that allows you to set the number of seconds before GDB gives up trying
6875 to read from the target. The default value is 2.
6877 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6879 By default GDB will automatically keep track of objects as they are
6880 loaded and unloaded by the dynamic linker. By using the command `set
6881 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6882 when shared library events occur, thus allowing you to set breakpoints
6883 in shared libraries which are explicitly loaded by the inferior.
6885 Note this feature does not work on hpux8. On hpux9 you must link
6886 /usr/lib/end.o into your program. This feature should work
6887 automatically on hpux10.
6889 * Irix 5.x hardware watchpoint support
6891 Irix 5 configurations now support the use of hardware watchpoints.
6893 * Mips protocol "SYN garbage limit"
6895 When debugging a Mips target using the `target mips' protocol, you
6896 may set the number of characters that GDB will ignore by setting
6897 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6898 every character. The default value is 1050.
6900 * Recording and replaying remote debug sessions
6902 If you set `remotelogfile' to the name of a file, gdb will write to it
6903 a recording of a remote debug session. This recording may then be
6904 replayed back to gdb using "gdbreplay". See gdbserver/README for
6905 details. This is useful when you have a problem with GDB while doing
6906 remote debugging; you can make a recording of the session and send it
6907 to someone else, who can then recreate the problem.
6909 * Speedups for remote debugging
6911 GDB includes speedups for downloading and stepping MIPS systems using
6912 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6913 and more efficient S-record downloading.
6915 * Memory use reductions and statistics collection
6917 GDB now uses less memory and reports statistics about memory usage.
6918 Try the `maint print statistics' command, for example.
6920 *** Changes in GDB-4.15:
6922 * Psymtabs for XCOFF
6924 The symbol reader for AIX GDB now uses partial symbol tables. This
6925 can greatly improve startup time, especially for large executables.
6927 * Remote targets use caching
6929 Remote targets now use a data cache to speed up communication with the
6930 remote side. The data cache could lead to incorrect results because
6931 it doesn't know about volatile variables, thus making it impossible to
6932 debug targets which use memory mapped I/O devices. `set remotecache
6933 off' turns the data cache off.
6935 * Remote targets may have threads
6937 The standard remote protocol now includes support for multiple threads
6938 in the target system, using new protocol commands 'H' and 'T'. See
6939 gdb/remote.c for details.
6943 If GDB is configured with `--enable-netrom', then it will include
6944 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6945 acts as though it is a bank of ROM on the target board, but you can
6946 write into it over the network. GDB's support consists only of
6947 support for fast loading into the emulated ROM; to debug, you must use
6948 another protocol, such as standard remote protocol. The usual
6949 sequence is something like
6951 target nrom <netrom-hostname>
6953 target remote <netrom-hostname>:1235
6957 GDB now includes support for the Apple Macintosh, as a host only. It
6958 may be run as either an MPW tool or as a standalone application, and
6959 it can debug through the serial port. All the usual GDB commands are
6960 available, but to the target command, you must supply "serial" as the
6961 device type instead of "/dev/ttyXX". See mpw-README in the main
6962 directory for more information on how to build. The MPW configuration
6963 scripts */mpw-config.in support only a few targets, and only the
6964 mips-idt-ecoff target has been tested.
6968 GDB configuration now uses autoconf. This is not user-visible,
6969 but does simplify configuration and building.
6973 GDB now supports hpux10.
6975 *** Changes in GDB-4.14:
6977 * New native configurations
6979 x86 FreeBSD i[345]86-*-freebsd
6980 x86 NetBSD i[345]86-*-netbsd
6981 NS32k NetBSD ns32k-*-netbsd
6982 Sparc NetBSD sparc-*-netbsd
6986 A29K VxWorks a29k-*-vxworks
6987 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6988 CPU32 EST-300 emulator m68*-*-est*
6989 PowerPC ELF powerpc-*-elf
6992 * Alpha OSF/1 support for procfs
6994 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6995 possible to attach to running processes. As the mounting of the /proc
6996 filesystem is optional on the Alpha, GDB automatically determines
6997 the availability of /proc during startup. This can lead to problems
6998 if /proc is unmounted after GDB has been started.
7000 * Arguments to user-defined commands
7002 User commands may accept up to 10 arguments separated by whitespace.
7003 Arguments are accessed within the user command via $arg0..$arg9. A
7006 print $arg0 + $arg1 + $arg2
7008 To execute the command use:
7011 Defines the command "adder" which prints the sum of its three arguments.
7012 Note the arguments are text substitutions, so they may reference variables,
7013 use complex expressions, or even perform inferior function calls.
7015 * New `if' and `while' commands
7017 This makes it possible to write more sophisticated user-defined
7018 commands. Both commands take a single argument, which is the
7019 expression to evaluate, and must be followed by the commands to
7020 execute, one per line, if the expression is nonzero, the list being
7021 terminated by the word `end'. The `if' command list may include an
7022 `else' word, which causes the following commands to be executed only
7023 if the expression is zero.
7025 * Fortran source language mode
7027 GDB now includes partial support for Fortran 77. It will recognize
7028 Fortran programs and can evaluate a subset of Fortran expressions, but
7029 variables and functions may not be handled correctly. GDB will work
7030 with G77, but does not yet know much about symbols emitted by other
7033 * Better HPUX support
7035 Most debugging facilities now work on dynamic executables for HPPAs
7036 running hpux9 or later. You can attach to running dynamically linked
7037 processes, but by default the dynamic libraries will be read-only, so
7038 for instance you won't be able to put breakpoints in them. To change
7039 that behavior do the following before running the program:
7045 This will cause the libraries to be mapped private and read-write.
7046 To revert to the normal behavior, do this:
7052 You cannot set breakpoints or examine data in the library until after
7053 the library is loaded if the function/data symbols do not have
7056 GDB can now also read debug symbols produced by the HP C compiler on
7057 HPPAs (sorry, no C++, Fortran or 68k support).
7059 * Target byte order now dynamically selectable
7061 You can choose which byte order to use with a target system, via the
7062 commands "set endian big" and "set endian little", and you can see the
7063 current setting by using "show endian". You can also give the command
7064 "set endian auto", in which case GDB will use the byte order
7065 associated with the executable. Currently, only embedded MIPS
7066 configurations support dynamic selection of target byte order.
7068 * New DOS host serial code
7070 This version uses DPMI interrupts to handle buffered I/O, so you
7071 no longer need to run asynctsr when debugging boards connected to
7074 *** Changes in GDB-4.13:
7076 * New "complete" command
7078 This lists all the possible completions for the rest of the line, if it
7079 were to be given as a command itself. This is intended for use by emacs.
7081 * Trailing space optional in prompt
7083 "set prompt" no longer adds a space for you after the prompt you set. This
7084 allows you to set a prompt which ends in a space or one that does not.
7086 * Breakpoint hit counts
7088 "info break" now displays a count of the number of times the breakpoint
7089 has been hit. This is especially useful in conjunction with "ignore"; you
7090 can ignore a large number of breakpoint hits, look at the breakpoint info
7091 to see how many times the breakpoint was hit, then run again, ignoring one
7092 less than that number, and this will get you quickly to the last hit of
7095 * Ability to stop printing at NULL character
7097 "set print null-stop" will cause GDB to stop printing the characters of
7098 an array when the first NULL is encountered. This is useful when large
7099 arrays actually contain only short strings.
7101 * Shared library breakpoints
7103 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7104 breakpoints in shared libraries before the executable is run.
7106 * Hardware watchpoints
7108 There is a new hardware breakpoint for the watch command for sparclite
7109 targets. See gdb/sparclite/hw_breakpoint.note.
7111 Hardware watchpoints are also now supported under GNU/Linux.
7115 Annotations have been added. These are for use with graphical interfaces,
7116 and are still experimental. Currently only gdba.el uses these.
7118 * Improved Irix 5 support
7120 GDB now works properly with Irix 5.2.
7122 * Improved HPPA support
7124 GDB now works properly with the latest GCC and GAS.
7126 * New native configurations
7128 Sequent PTX4 i[34]86-sequent-ptx4
7129 HPPA running OSF/1 hppa*-*-osf*
7130 Atari TT running SVR4 m68*-*-sysv4*
7131 RS/6000 LynxOS rs6000-*-lynxos*
7135 OS/9000 i[34]86-*-os9k
7136 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7139 * Hitachi SH7000 and E7000-PC ICE support
7141 There is now support for communicating with the Hitachi E7000-PC ICE.
7142 This is available automatically when GDB is configured for the SH.
7146 As usual, a variety of small fixes and improvements, both generic
7147 and configuration-specific. See the ChangeLog for more detail.
7149 *** Changes in GDB-4.12:
7151 * Irix 5 is now supported
7155 GDB-4.12 on the HPPA has a number of changes which make it unable
7156 to debug the output from the currently released versions of GCC and
7157 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7158 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7159 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7162 *** Changes in GDB-4.11:
7164 * User visible changes:
7168 The "set remotedebug" option is now consistent between the mips remote
7169 target, remote targets using the gdb-specific protocol, UDI (AMD's
7170 debug protocol for the 29k) and the 88k bug monitor. It is now an
7171 integer specifying a debug level (normally 0 or 1, but 2 means more
7172 debugging info for the mips target).
7174 * DEC Alpha native support
7176 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7177 debug info, but GDB works fairly well with the DEC compiler and should
7178 work with a future GCC release. See the README file for a few
7179 Alpha-specific notes.
7181 * Preliminary thread implementation
7183 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7185 * LynxOS native and target support for 386
7187 This release has been hosted on LynxOS 2.2, and also can be configured
7188 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7191 * Improvements in C++ mangling/demangling.
7193 This release has much better g++ debugging, specifically in name
7194 mangling/demangling, virtual function calls, print virtual table,
7195 call methods, ...etc.
7197 *** Changes in GDB-4.10:
7199 * User visible changes:
7201 Remote debugging using the GDB-specific (`target remote') protocol now
7202 supports the `load' command. This is only useful if you have some
7203 other way of getting the stub to the target system, and you can put it
7204 somewhere in memory where it won't get clobbered by the download.
7206 Filename completion now works.
7208 When run under emacs mode, the "info line" command now causes the
7209 arrow to point to the line specified. Also, "info line" prints
7210 addresses in symbolic form (as well as hex).
7212 All vxworks based targets now support a user settable option, called
7213 vxworks-timeout. This option represents the number of seconds gdb
7214 should wait for responses to rpc's. You might want to use this if
7215 your vxworks target is, perhaps, a slow software simulator or happens
7216 to be on the far side of a thin network line.
7220 This release contains support for using a DEC alpha as a GDB host for
7221 cross debugging. Native alpha debugging is not supported yet.
7224 *** Changes in GDB-4.9:
7228 This is the first GDB release which is accompanied by a matching testsuite.
7229 The testsuite requires installation of dejagnu, which should be available
7230 via ftp from most sites that carry GNU software.
7234 'Cfront' style demangling has had its name changed to 'ARM' style, to
7235 emphasize that it was written from the specifications in the C++ Annotated
7236 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7237 disclaimers, it still generated too much confusion with users attempting to
7238 use gdb with AT&T cfront.
7242 GDB now uses a standard remote interface to a simulator library.
7243 So far, the library contains simulators for the Zilog Z8001/2, the
7244 Hitachi H8/300, H8/500 and Super-H.
7246 * New targets supported
7248 H8/300 simulator h8300-hitachi-hms or h8300hms
7249 H8/500 simulator h8500-hitachi-hms or h8500hms
7250 SH simulator sh-hitachi-hms or sh
7251 Z8000 simulator z8k-zilog-none or z8ksim
7252 IDT MIPS board over serial line mips-idt-ecoff
7254 Cross-debugging to GO32 targets is supported. It requires a custom
7255 version of the i386-stub.c module which is integrated with the
7256 GO32 memory extender.
7258 * New remote protocols
7260 MIPS remote debugging protocol.
7262 * New source languages supported
7264 This version includes preliminary support for Chill, a Pascal like language
7265 used by telecommunications companies. Chill support is also being integrated
7266 into the GNU compiler, but we don't know when it will be publically available.
7269 *** Changes in GDB-4.8:
7271 * HP Precision Architecture supported
7273 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7274 version of this support was available as a set of patches from the
7275 University of Utah. GDB does not support debugging of programs
7276 compiled with the HP compiler, because HP will not document their file
7277 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7278 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7280 Many problems in the preliminary version have been fixed.
7282 * Faster and better demangling
7284 We have improved template demangling and fixed numerous bugs in the GNU style
7285 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7286 character types (wchar_t) are now supported. Demangling of each symbol is now
7287 only done once, and is cached when the symbol table for a file is read in.
7288 This results in a small increase in memory usage for C programs, a moderate
7289 increase in memory usage for C++ programs, and a fantastic speedup in
7292 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7293 from the specifications in the Annotated Reference Manual, which AT&T's
7294 compiler does not actually implement.
7296 * G++ multiple inheritance compiler problem
7298 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7299 inheritance lattices was reworked to properly discover ambiguities. We
7300 recently found an example which causes this new algorithm to fail in a
7301 very subtle way, producing bad debug information for those classes.
7302 The file 'gcc.patch' (in this directory) can be applied to gcc to
7303 circumvent the problem. A future GCC release will contain a complete
7306 The previous G++ debug info problem (mentioned below for the gdb-4.7
7307 release) is fixed in gcc version 2.3.2.
7309 * Improved configure script
7311 The `configure' script will now attempt to guess your system type if
7312 you don't supply a host system type. The old scheme of supplying a
7313 host system triplet is preferable over using this. All the magic is
7314 done in the new `config.guess' script. Examine it for details.
7316 We have also brought our configure script much more in line with the FSF's
7317 version. It now supports the --with-xxx options. In particular,
7318 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7319 The resulting GDB will not be able to read arbitrary object file formats --
7320 only the format ``expected'' to be used on the configured target system.
7321 We hope to make this the default in a future release.
7323 * Documentation improvements
7325 There's new internal documentation on how to modify GDB, and how to
7326 produce clean changes to the code. We implore people to read it
7327 before submitting changes.
7329 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7330 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7331 `info' files are also provided. To build `info' files from scratch,
7332 you will need the latest `makeinfo' release, which will be available in
7333 a future texinfo-X.Y release.
7335 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7336 We're not sure exactly which versions have this problem, but it has
7337 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7338 or better. If that isn't possible, there is a patch in
7339 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7340 around this problem.
7344 GDB now supports array constants that can be used in expressions typed in by
7345 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7346 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7349 The new directory `gdb/sparclite' contains a program that demonstrates
7350 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7352 * New native hosts supported
7354 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7355 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7357 * New targets supported
7359 AMD 29k family via UDI a29k-amd-udi or udi29k
7361 * New file formats supported
7363 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7364 HPUX core files, and SCO 3.2v2 core files.
7368 Attaching to processes now works again; thanks for the many bug reports.
7370 We have also stomped on a bunch of core dumps caused by
7371 printf_filtered("%s") problems.
7373 We eliminated a copyright problem on the rpc and ptrace header files
7374 for VxWorks, which was discovered at the last minute during the 4.7
7375 release. You should now be able to build a VxWorks GDB.
7377 You can now interrupt gdb while an attached process is running. This
7378 will cause the attached process to stop, and give control back to GDB.
7380 We fixed problems caused by using too many file descriptors
7381 for reading symbols from object files and libraries. This was
7382 especially a problem for programs that used many (~100) shared
7385 The `step' command now only enters a subroutine if there is line number
7386 information for the subroutine. Otherwise it acts like the `next'
7387 command. Previously, `step' would enter subroutines if there was
7388 any debugging information about the routine. This avoids problems
7389 when using `cc -g1' on MIPS machines.
7391 * Internal improvements
7393 GDB's internal interfaces have been improved to make it easier to support
7394 debugging of multiple languages in the future.
7396 GDB now uses a common structure for symbol information internally.
7397 Minimal symbols (derived from linkage symbols in object files), partial
7398 symbols (from a quick scan of debug information), and full symbols
7399 contain a common subset of information, making it easier to write
7400 shared code that handles any of them.
7402 * New command line options
7404 We now accept --silent as an alias for --quiet.
7408 The memory-mapped-malloc library is now licensed under the GNU Library
7409 General Public License.
7411 *** Changes in GDB-4.7:
7413 * Host/native/target split
7415 GDB has had some major internal surgery to untangle the support for
7416 hosts and remote targets. Now, when you configure GDB for a remote
7417 target, it will no longer load in all of the support for debugging
7418 local programs on the host. When fully completed and tested, this will
7419 ensure that arbitrary host/target combinations are possible.
7421 The primary conceptual shift is to separate the non-portable code in
7422 GDB into three categories. Host specific code is required any time GDB
7423 is compiled on that host, regardless of the target. Target specific
7424 code relates to the peculiarities of the target, but can be compiled on
7425 any host. Native specific code is everything else: it can only be
7426 built when the host and target are the same system. Child process
7427 handling and core file support are two common `native' examples.
7429 GDB's use of /proc for controlling Unix child processes is now cleaner.
7430 It has been split out into a single module under the `target_ops' vector,
7431 plus two native-dependent functions for each system that uses /proc.
7433 * New hosts supported
7435 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7436 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7437 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7439 * New targets supported
7441 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7442 68030 and CPU32 m68030-*-*, m68332-*-*
7444 * New native hosts supported
7446 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7447 (386bsd is not well tested yet)
7448 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7450 * New file formats supported
7452 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7453 supports reading of `a.out.adobe' object files, which are an a.out
7454 format extended with minimal information about multiple sections.
7458 `show copying' is the same as the old `info copying'.
7459 `show warranty' is the same as `info warrantee'.
7460 These were renamed for consistency. The old commands continue to work.
7462 `info handle' is a new alias for `info signals'.
7464 You can now define pre-command hooks, which attach arbitrary command
7465 scripts to any command. The commands in the hook will be executed
7466 prior to the user's command. You can also create a hook which will be
7467 executed whenever the program stops. See gdb.texinfo.
7471 We now deal with Cfront style name mangling, and can even extract type
7472 info from mangled symbols. GDB can automatically figure out which
7473 symbol mangling style your C++ compiler uses.
7475 Calling of methods and virtual functions has been improved as well.
7479 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7480 fixed. This was due to mishandling of the extra N_SO stabs output
7483 We also finally got Ultrix 4.2 running in house, and fixed core file
7484 support, with help from a dozen people on the net.
7486 John M. Farrell discovered that the reason that single-stepping was so
7487 slow on all of the Mips based platforms (primarily SGI and DEC) was
7488 that we were trying to demangle and lookup a symbol used for internal
7489 purposes on every instruction that was being stepped through. Changing
7490 the name of that symbol so that it couldn't be mistaken for a C++
7491 mangled symbol sped things up a great deal.
7493 Rich Pixley sped up symbol lookups in general by getting much smarter
7494 about when C++ symbol mangling is necessary. This should make symbol
7495 completion (TAB on the command line) much faster. It's not as fast as
7496 we'd like, but it's significantly faster than gdb-4.6.
7500 A new user controllable variable 'call_scratch_address' can
7501 specify the location of a scratch area to be used when GDB
7502 calls a function in the target. This is necessary because the
7503 usual method of putting the scratch area on the stack does not work
7504 in systems that have separate instruction and data spaces.
7506 We integrated changes to support the 29k UDI (Universal Debugger
7507 Interface), but discovered at the last minute that we didn't have all
7508 of the appropriate copyright paperwork. We are working with AMD to
7509 resolve this, and hope to have it available soon.
7513 We have sped up the remote serial line protocol, especially for targets
7514 with lots of registers. It now supports a new `expedited status' ('T')
7515 message which can be used in place of the existing 'S' status message.
7516 This allows the remote stub to send only the registers that GDB
7517 needs to make a quick decision about single-stepping or conditional
7518 breakpoints, eliminating the need to fetch the entire register set for
7519 each instruction being stepped through.
7521 The GDB remote serial protocol now implements a write-through cache for
7522 registers, only re-reading the registers if the target has run.
7524 There is also a new remote serial stub for SPARC processors. You can
7525 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7526 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7527 processor with a serial port.
7531 Configure.in files have become much easier to read and modify. A new
7532 `table driven' format makes it more obvious what configurations are
7533 supported, and what files each one uses.
7537 There is a new opcodes library which will eventually contain all of the
7538 disassembly routines and opcode tables. At present, it only contains
7539 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7540 disassembler (binutils/objdump) to share these routines.
7542 The libiberty library is now copylefted under the GNU Library General
7543 Public License. This allows more liberal use, and was done so libg++
7544 can use it. This makes no difference to GDB, since the Library License
7545 grants all the rights from the General Public License.
7549 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7550 reference to the stabs symbol info used by the debugger. It is (as far
7551 as we know) the only published document on this fascinating topic. We
7552 encourage you to read it, compare it to the stabs information on your
7553 system, and send improvements on the document in general (to
7554 bug-gdb@prep.ai.mit.edu).
7556 And, of course, many bugs have been fixed.
7559 *** Changes in GDB-4.6:
7561 * Better support for C++ function names
7563 GDB now accepts as input the "demangled form" of C++ overloaded function
7564 names and member function names, and can do command completion on such names
7565 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7566 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7567 Make use of command completion, it is your friend.
7569 GDB also now accepts a variety of C++ mangled symbol formats. They are
7570 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7571 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7572 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7573 for the list of formats.
7575 * G++ symbol mangling problem
7577 Recent versions of gcc have a bug in how they emit debugging information for
7578 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7579 directory) can be applied to gcc to fix the problem. Alternatively, if you
7580 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7581 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7582 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7585 * New 'maintenance' command
7587 All of the commands related to hacking GDB internals have been moved out of
7588 the main command set, and now live behind the 'maintenance' command. This
7589 can also be abbreviated as 'mt'. The following changes were made:
7591 dump-me -> maintenance dump-me
7592 info all-breakpoints -> maintenance info breakpoints
7593 printmsyms -> maintenance print msyms
7594 printobjfiles -> maintenance print objfiles
7595 printpsyms -> maintenance print psymbols
7596 printsyms -> maintenance print symbols
7598 The following commands are new:
7600 maintenance demangle Call internal GDB demangler routine to
7601 demangle a C++ link name and prints the result.
7602 maintenance print type Print a type chain for a given symbol
7604 * Change to .gdbinit file processing
7606 We now read the $HOME/.gdbinit file before processing the argv arguments
7607 (e.g. reading symbol files or core files). This allows global parameters to
7608 be set, which will apply during the symbol reading. The ./.gdbinit is still
7609 read after argv processing.
7611 * New hosts supported
7613 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7615 GNU/Linux support i386-unknown-linux or linux
7617 We are also including code to support the HP/PA running BSD and HPUX. This
7618 is almost guaranteed not to work, as we didn't have time to test or build it
7619 for this release. We are including it so that the more adventurous (or
7620 masochistic) of you can play with it. We also had major problems with the
7621 fact that the compiler that we got from HP doesn't support the -g option.
7624 * New targets supported
7626 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7628 * More smarts about finding #include files
7630 GDB now remembers the compilation directory for all include files, and for
7631 all files from which C is generated (like yacc and lex sources). This
7632 greatly improves GDB's ability to find yacc/lex sources, and include files,
7633 especially if you are debugging your program from a directory different from
7634 the one that contains your sources.
7636 We also fixed a bug which caused difficulty with listing and setting
7637 breakpoints in include files which contain C code. (In the past, you had to
7638 try twice in order to list an include file that you hadn't looked at before.)
7640 * Interesting infernals change
7642 GDB now deals with arbitrary numbers of sections, where the symbols for each
7643 section must be relocated relative to that section's landing place in the
7644 target's address space. This work was needed to support ELF with embedded
7645 stabs used by Solaris-2.0.
7647 * Bug fixes (of course!)
7649 There have been loads of fixes for the following things:
7650 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7651 i960, stabs, DOS(GO32), procfs, etc...
7653 See the ChangeLog for details.
7655 *** Changes in GDB-4.5:
7657 * New machines supported (host and target)
7659 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7661 SGI Irix-4.x mips-sgi-irix4 or iris4
7663 * New malloc package
7665 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7666 Mmalloc is capable of handling multiple heaps of memory. It is also
7667 capable of saving a heap to a file, and then mapping it back in later.
7668 This can be used to greatly speedup the startup of GDB by using a
7669 pre-parsed symbol table which lives in a mmalloc managed heap. For
7670 more details, please read mmalloc/mmalloc.texi.
7674 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7675 'help info proc' for details.
7677 * MIPS ecoff symbol table format
7679 The code that reads MIPS symbol table format is now supported on all hosts.
7680 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7683 * File name changes for MS-DOS
7685 Many files in the config directories have been renamed to make it easier to
7686 support GDB on MS-DOSe systems (which have very restrictive file name
7687 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7688 environment) is close to working but has some remaining problems. Note
7689 that debugging of DOS programs is not supported, due to limitations
7690 in the ``operating system'', but it can be used to host cross-debugging.
7692 * Cross byte order fixes
7694 Many fixes have been made to support cross debugging of Sparc and MIPS
7695 targets from hosts whose byte order differs.
7697 * New -mapped and -readnow options
7699 If memory-mapped files are available on your system through the 'mmap'
7700 system call, you can use the -mapped option on the `file' or
7701 `symbol-file' commands to cause GDB to write the symbols from your
7702 program into a reusable file. If the program you are debugging is
7703 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7704 Future GDB debugging sessions will notice the presence of this file,
7705 and will quickly map in symbol information from it, rather than reading
7706 the symbol table from the executable program. Using the '-mapped'
7707 option in a GDB `file' or `symbol-file' command has the same effect as
7708 starting GDB with the '-mapped' command-line option.
7710 You can cause GDB to read the entire symbol table immediately by using
7711 the '-readnow' option with any of the commands that load symbol table
7712 information (or on the GDB command line). This makes the command
7713 slower, but makes future operations faster.
7715 The -mapped and -readnow options are typically combined in order to
7716 build a `fred.syms' file that contains complete symbol information.
7717 A simple GDB invocation to do nothing but build a `.syms' file for future
7720 gdb -batch -nx -mapped -readnow programname
7722 The `.syms' file is specific to the host machine on which GDB is run.
7723 It holds an exact image of GDB's internal symbol table. It cannot be
7724 shared across multiple host platforms.
7726 * longjmp() handling
7728 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7729 siglongjmp() without losing control. This feature has not yet been ported to
7730 all systems. It currently works on many 386 platforms, all MIPS-based
7731 platforms (SGI, DECstation, etc), and Sun3/4.
7735 Preliminary work has been put in to support the new Solaris OS from Sun. At
7736 this time, it can control and debug processes, but it is not capable of
7741 As always, many many bug fixes. The major areas were with g++, and mipsread.
7742 People using the MIPS-based platforms should experience fewer mysterious
7743 crashes and trashed symbol tables.
7745 *** Changes in GDB-4.4:
7747 * New machines supported (host and target)
7749 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7751 BSD Reno on Vax vax-dec-bsd
7752 Ultrix on Vax vax-dec-ultrix
7754 * New machines supported (target)
7756 AMD 29000 embedded, using EBMON a29k-none-none
7760 GDB continues to improve its handling of C++. `References' work better.
7761 The demangler has also been improved, and now deals with symbols mangled as
7762 per the Annotated C++ Reference Guide.
7764 GDB also now handles `stabs' symbol information embedded in MIPS
7765 `ecoff' symbol tables. Since the ecoff format was not easily
7766 extensible to handle new languages such as C++, this appeared to be a
7767 good way to put C++ debugging info into MIPS binaries. This option
7768 will be supported in the GNU C compiler, version 2, when it is
7771 * New features for SVR4
7773 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7774 shared libraries. Debugging dynamically linked programs should present
7775 only minor differences from debugging statically linked programs.
7777 The `info proc' command will print out information about any process
7778 on an SVR4 system (including the one you are debugging). At the moment,
7779 it prints the address mappings of the process.
7781 If you bring up GDB on another SVR4 system, please send mail to
7782 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7784 * Better dynamic linking support in SunOS
7786 Reading symbols from shared libraries which contain debugging symbols
7787 now works properly. However, there remain issues such as automatic
7788 skipping of `transfer vector' code during function calls, which
7789 make it harder to debug code in a shared library, than to debug the
7790 same code linked statically.
7794 GDB is now using the latest `getopt' routines from the FSF. This
7795 version accepts the -- prefix for options with long names. GDB will
7796 continue to accept the old forms (-option and +option) as well.
7797 Various single letter abbreviations for options have been explicity
7798 added to the option table so that they won't get overshadowed in the
7799 future by other options that begin with the same letter.
7803 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7804 Many assorted bugs have been handled. Many more remain to be handled.
7805 See the various ChangeLog files (primarily in gdb and bfd) for details.
7808 *** Changes in GDB-4.3:
7810 * New machines supported (host and target)
7812 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7813 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7814 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7816 * Almost SCO Unix support
7818 We had hoped to support:
7819 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7820 (except for core file support), but we discovered very late in the release
7821 that it has problems with process groups that render gdb unusable. Sorry
7822 about that. I encourage people to fix it and post the fixes.
7824 * Preliminary ELF and DWARF support
7826 GDB can read ELF object files on System V Release 4, and can handle
7827 debugging records for C, in DWARF format, in ELF files. This support
7828 is preliminary. If you bring up GDB on another SVR4 system, please
7829 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7834 GDB now uses the latest `readline' library. One user-visible change
7835 is that two tabs will list possible command completions, which previously
7836 required typing M-? (meta-question mark, or ESC ?).
7840 The `stepi' bug that many of you noticed has been squashed.
7841 Many bugs in C++ have been handled. Many more remain to be handled.
7842 See the various ChangeLog files (primarily in gdb and bfd) for details.
7844 * State of the MIPS world (in case you wondered):
7846 GDB can understand the symbol tables emitted by the compilers
7847 supplied by most vendors of MIPS-based machines, including DEC. These
7848 symbol tables are in a format that essentially nobody else uses.
7850 Some versions of gcc come with an assembler post-processor called
7851 mips-tfile. This program is required if you want to do source-level
7852 debugging of gcc-compiled programs. I believe FSF does not ship
7853 mips-tfile with gcc version 1, but it will eventually come with gcc
7856 Debugging of g++ output remains a problem. g++ version 1.xx does not
7857 really support it at all. (If you're lucky, you should be able to get
7858 line numbers and stack traces to work, but no parameters or local
7859 variables.) With some work it should be possible to improve the
7862 When gcc version 2 is released, you will have somewhat better luck.
7863 However, even then you will get confusing results for inheritance and
7866 We will eventually provide full debugging of g++ output on
7867 DECstations. This will probably involve some kind of stabs-in-ecoff
7868 encapulation, but the details have not been worked out yet.
7871 *** Changes in GDB-4.2:
7873 * Improved configuration
7875 Only one copy of `configure' exists now, and it is not self-modifying.
7876 Porting BFD is simpler.
7880 The `step' and `next' commands now only stop at the first instruction
7881 of a source line. This prevents the multiple stops that used to occur
7882 in switch statements, for-loops, etc. `Step' continues to stop if a
7883 function that has debugging information is called within the line.
7887 Lots of small bugs fixed. More remain.
7889 * New host supported (not target)
7891 Intel 386 PC clone running Mach i386-none-mach
7894 *** Changes in GDB-4.1:
7896 * Multiple source language support
7898 GDB now has internal scaffolding to handle several source languages.
7899 It determines the type of each source file from its filename extension,
7900 and will switch expression parsing and number formatting to match the
7901 language of the function in the currently selected stack frame.
7902 You can also specifically set the language to be used, with
7903 `set language c' or `set language modula-2'.
7907 GDB now has preliminary support for the GNU Modula-2 compiler,
7908 currently under development at the State University of New York at
7909 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7910 continue through the fall of 1991 and into 1992.
7912 Other Modula-2 compilers are currently not supported, and attempting to
7913 debug programs compiled with them will likely result in an error as the
7914 symbol table is read. Feel free to work on it, though!
7916 There are hooks in GDB for strict type checking and range checking,
7917 in the `Modula-2 philosophy', but they do not currently work.
7921 GDB can now write to executable and core files (e.g. patch
7922 a variable's value). You must turn this switch on, specify
7923 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7924 by assigning a new value to a variable. Modifications take
7927 * Automatic SunOS shared library reading
7929 When you run your program, GDB automatically determines where its
7930 shared libraries (if any) have been loaded, and reads their symbols.
7931 The `share' command is no longer needed. This also works when
7932 examining core files.
7936 You can specify the number of lines that the `list' command shows.
7939 * New machines supported (host and target)
7941 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7942 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7943 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7945 * New hosts supported (not targets)
7947 IBM RT/PC: romp-ibm-aix or rtpc
7949 * New targets supported (not hosts)
7951 AMD 29000 embedded with COFF a29k-none-coff
7952 AMD 29000 embedded with a.out a29k-none-aout
7953 Ultracomputer remote kernel debug a29k-nyu-kern
7955 * New remote interfaces
7961 *** Changes in GDB-4.0:
7965 Wide output is wrapped at good places to make the output more readable.
7967 Gdb now supports cross-debugging from a host machine of one type to a
7968 target machine of another type. Communication with the target system
7969 is over serial lines. The ``target'' command handles connecting to the
7970 remote system; the ``load'' command will download a program into the
7971 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7972 also supports debugging of realtime processes running under VxWorks,
7973 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7974 stub on the target system.
7976 New CPUs supported include the AMD 29000 and Intel 960.
7978 GDB now reads object files and symbol tables via a ``binary file''
7979 library, which allows a single copy of GDB to debug programs of multiple
7980 object file types such as a.out and coff.
7982 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7983 refcard.dvi and refcard.ps are available to format it).
7986 * Control-Variable user interface simplified
7988 All variables that control the operation of the debugger can be set
7989 by the ``set'' command, and displayed by the ``show'' command.
7991 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7992 ``Show prompt'' produces the response:
7993 Gdb's prompt is new-gdb=>.
7995 What follows are the NEW set commands. The command ``help set'' will
7996 print a complete list of old and new set commands. ``help set FOO''
7997 will give a longer description of the variable FOO. ``show'' will show
7998 all of the variable descriptions and their current settings.
8000 confirm on/off: Enables warning questions for operations that are
8001 hard to recover from, e.g. rerunning the program while
8002 it is already running. Default is ON.
8004 editing on/off: Enables EMACS style command line editing
8005 of input. Previous lines can be recalled with
8006 control-P, the current line can be edited with control-B,
8007 you can search for commands with control-R, etc.
8010 history filename NAME: NAME is where the gdb command history
8011 will be stored. The default is .gdb_history,
8012 or the value of the environment variable
8015 history size N: The size, in commands, of the command history. The
8016 default is 256, or the value of the environment variable
8019 history save on/off: If this value is set to ON, the history file will
8020 be saved after exiting gdb. If set to OFF, the
8021 file will not be saved. The default is OFF.
8023 history expansion on/off: If this value is set to ON, then csh-like
8024 history expansion will be performed on
8025 command line input. The default is OFF.
8027 radix N: Sets the default radix for input and output. It can be set
8028 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8029 in the current radix, so "set radix 10" is always a no-op.
8031 height N: This integer value is the number of lines on a page. Default
8032 is 24, the current `stty rows'' setting, or the ``li#''
8033 setting from the termcap entry matching the environment
8036 width N: This integer value is the number of characters on a line.
8037 Default is 80, the current `stty cols'' setting, or the ``co#''
8038 setting from the termcap entry matching the environment
8041 Note: ``set screensize'' is obsolete. Use ``set height'' and
8042 ``set width'' instead.
8044 print address on/off: Print memory addresses in various command displays,
8045 such as stack traces and structure values. Gdb looks
8046 more ``symbolic'' if you turn this off; it looks more
8047 ``machine level'' with it on. Default is ON.
8049 print array on/off: Prettyprint arrays. New convenient format! Default
8052 print demangle on/off: Print C++ symbols in "source" form if on,
8055 print asm-demangle on/off: Same, for assembler level printouts
8058 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8061 * Support for Epoch Environment.
8063 The epoch environment is a version of Emacs v18 with windowing. One
8064 new command, ``inspect'', is identical to ``print'', except that if you
8065 are running in the epoch environment, the value is printed in its own
8069 * Support for Shared Libraries
8071 GDB can now debug programs and core files that use SunOS shared libraries.
8072 Symbols from a shared library cannot be referenced
8073 before the shared library has been linked with the program (this
8074 happens after you type ``run'' and before the function main() is entered).
8075 At any time after this linking (including when examining core files
8076 from dynamically linked programs), gdb reads the symbols from each
8077 shared library when you type the ``sharedlibrary'' command.
8078 It can be abbreviated ``share''.
8080 sharedlibrary REGEXP: Load shared object library symbols for files
8081 matching a unix regular expression. No argument
8082 indicates to load symbols for all shared libraries.
8084 info sharedlibrary: Status of loaded shared libraries.
8089 A watchpoint stops execution of a program whenever the value of an
8090 expression changes. Checking for this slows down execution
8091 tremendously whenever you are in the scope of the expression, but is
8092 quite useful for catching tough ``bit-spreader'' or pointer misuse
8093 problems. Some machines such as the 386 have hardware for doing this
8094 more quickly, and future versions of gdb will use this hardware.
8096 watch EXP: Set a watchpoint (breakpoint) for an expression.
8098 info watchpoints: Information about your watchpoints.
8100 delete N: Deletes watchpoint number N (same as breakpoints).
8101 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8102 enable N: Re-enables watchpoint number N (same as breakpoints).
8105 * C++ multiple inheritance
8107 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8110 * C++ exception handling
8112 Gdb now supports limited C++ exception handling. Besides the existing
8113 ability to breakpoint on an exception handler, gdb can breakpoint on
8114 the raising of an exception (before the stack is peeled back to the
8117 catch FOO: If there is a FOO exception handler in the dynamic scope,
8118 set a breakpoint to catch exceptions which may be raised there.
8119 Multiple exceptions (``catch foo bar baz'') may be caught.
8121 info catch: Lists all exceptions which may be caught in the
8122 current stack frame.
8125 * Minor command changes
8127 The command ``call func (arg, arg, ...)'' now acts like the print
8128 command, except it does not print or save a value if the function's result
8129 is void. This is similar to dbx usage.
8131 The ``up'' and ``down'' commands now always print the frame they end up
8132 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8133 frames without printing.
8135 * New directory command
8137 'dir' now adds directories to the FRONT of the source search path.
8138 The path starts off empty. Source files that contain debug information
8139 about the directory in which they were compiled can be found even
8140 with an empty path; Sun CC and GCC include this information. If GDB can't
8141 find your source file in the current directory, type "dir .".
8143 * Configuring GDB for compilation
8145 For normal use, type ``./configure host''. See README or gdb.texinfo
8148 GDB now handles cross debugging. If you are remotely debugging between
8149 two different machines, type ``./configure host -target=targ''.
8150 Host is the machine where GDB will run; targ is the machine
8151 where the program that you are debugging will run.