1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * Help and apropos commands will now show the documentation of a
7 command only once, even if that command has one or more aliases.
8 These commands now show the command name, then all of its aliases,
9 and finally the description of the command.
11 * 'help aliases' now shows only the user defined aliases. GDB predefined
12 aliases are shown together with their aliased command.
14 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
15 debugging information as well as source code.
17 When built with debuginfod, GDB can automatically query debuginfod
18 servers for the separate debug files and source code of the executable
21 To build GDB with debuginfod, pass --with-debuginfod to configure (this
22 requires libdebuginfod, the debuginfod client library).
24 debuginfod is distributed with elfutils, starting with version 0.178.
26 You can get the latest version from https://sourceware.org/elfutils.
28 * New features in the GDB remote stub, GDBserver
30 ** GDBserver is now supported on RISC-V GNU/Linux.
32 ** GDBserver no longer supports these host triplets:
43 i[34567]86-*-mingw32ce*
45 * Debugging MS-Windows processes now sets $_exitsignal when the
46 inferior is terminated by a signal, instead of setting $_exitcode.
48 * Multithreaded symbol loading has now been enabled by default on systems
49 that support it (see entry for GDB 9, below), providing faster
50 performance for programs with many symbols.
52 * The $_siginfo convenience variable now also works on Windows targets,
53 and will display the EXCEPTION_RECORD of the last handled exception.
55 * TUI windows can now be arranged horizontally.
57 * The command history filename can now be set to the empty string
58 either using 'set history filename' or by setting 'GDBHISTFILE=' in
59 the environment. The effect of setting this filename to the empty
60 string is that GDB will not try to load any previous command
63 * On Windows targets, it is now possible to debug 32-bit programs with a
68 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
69 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
70 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
71 running process, this new option indicates whether to detect
72 a mismatch between the current executable file loaded by GDB and the
73 executable file used to start the process. If 'ask', the default,
74 display a warning and ask the user whether to load the process
75 executable file; if 'warn', just display a warning; if 'off', don't
76 attempt to detect a mismatch.
78 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
79 Define a new TUI layout, specifying its name and the windows that
82 maintenance print xml-tdesc [FILE]
83 Prints the current target description as an XML document. If the
84 optional FILE is provided (which is an XML target description) then
85 the target description is read from FILE into GDB, and then
90 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
91 The alias command can now specify default args for an alias.
92 GDB automatically prepends the alias default args to the argument list
93 provided explicitly by the user.
94 For example, to have a backtrace with full details, you can define
96 'alias bt_ALL = backtrace -entry-values both -frame-arg all
97 -past-main -past-entry -full'.
98 Alias default arguments can also use a set of nested 'with' commands,
99 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
100 defines the alias pp10 that will pretty print a maximum of 10 elements
101 of the given expression (if the expression is an array).
105 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
109 ** gdb.register_window_type can be used to implement new TUI windows
112 ** Dynamic types can now be queried. gdb.Type has a new attribute,
113 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
114 field of a dynamic type may have None for its "bitpos" attribute
117 ** Commands written in Python can be in the "TUI" help class by
118 registering with the new constant gdb.COMMAND_TUI.
120 ** New method gdb.PendingFrame.architecture () to retrieve the
121 architecture of the pending frame.
123 ** New gdb.Architecture.registers method that returns a
124 gdb.RegisterDescriptorIterator object, an iterator that returns
125 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
126 way to query the registers available for an architecture.
130 * 'thread-exited' event is now available in the annotations interface.
132 * New built-in convenience variables $_gdb_major and $_gdb_minor
133 provide the GDB version. They are handy for conditionally using
134 features available only in or since specific GDB versions, in
135 scripts that should work error-free with many different versions,
136 such as in system-wide init files.
138 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
139 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
140 of the GDB settings and the GDB maintenance settings. They are handy
141 for changing the logic of user defined commands depending on the
142 current GDB settings.
144 * GDB now supports Thread Local Storage (TLS) variables on several
145 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
146 architectures require kernel changes. TLS is not yet supported for
147 amd64 and i386 process core dumps.
149 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
150 addresses that required unmasking are shown in the backtrace with the
153 * Two new convenience functions $_cimag and $_creal that extract the
154 imaginary and real parts respectively from complex numbers.
156 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
157 provide the exitcode or exit status of the shell commands launched by
158 GDB commands such as "shell", "pipe" and "make".
160 * The command define-prefix can now define user defined prefix commands.
161 User defined commands can now be defined using these user defined prefix
164 * Command names can now use the . character.
166 * The RX port now supports XML target descriptions.
168 * GDB now shows the Ada task names at more places, e.g. in task switching
171 * GDB can now be compiled with Python 3 on Windows.
173 * New convenience variable $_ada_exception holds the address of the
174 Ada exception being thrown. This is set by Ada-related catchpoints.
176 * GDB can now place breakpoints on nested functions and subroutines in
177 Fortran code. The '::' operator can be used between parent and
178 child scopes when placing breakpoints, for example:
180 (gdb) break outer_function::inner_function
182 The 'outer_function::' prefix is only needed if 'inner_function' is
183 not visible in the current scope.
185 * In addition to the system-wide gdbinit file, if configured with
186 --with-system-gdbinit-dir, GDB will now also load files in that directory
187 as system gdbinit files, unless the -nx or -n flag is provided. Files
188 with extensions .gdb, .py and .scm are supported as long as GDB was
189 compiled with support for that language.
191 * GDB now supports multithreaded symbol loading for higher performance.
192 This feature is still in testing, so it is disabled by default. You
193 can turn it on using 'maint set worker-threads unlimited'.
195 * Multi-target debugging support
197 GDB now supports debugging multiple target connections
198 simultaneously. For example, you can now have each inferior
199 connected to different remote servers running in different machines,
200 or have one inferior debugging a local native process, an inferior
201 debugging a core dump, etc.
203 This support is experimental and comes with some limitations -- you
204 can only resume multiple targets simultaneously if all targets
205 support non-stop mode, and all remote stubs or servers must support
206 the same set of remote protocol features exactly. See also "info
207 connections" and "add-inferior -no-connection" below, and "maint set
208 target-non-stop" in the user manual.
212 ** The gdb.Value type has a new method 'format_string' which returns a
213 string representing the value. The formatting is controlled by the
214 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
215 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
216 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
218 ** gdb.Type has a new property 'objfile' which returns the objfile the
221 ** The frame information printed by the python frame filtering code
222 is now consistent with what the 'backtrace' command prints when
223 there are no filters, or when the 'backtrace' '-no-filters' option
226 ** The new function gdb.lookup_static_symbol can be used to look up
227 symbols with static linkage.
229 ** The new function gdb.lookup_static_symbols can be used to look up
230 all static symbols with static linkage.
232 ** gdb.Objfile has new methods 'lookup_global_symbol' and
233 'lookup_static_symbol' to lookup a symbol from this objfile only.
235 ** gdb.Block now supports the dictionary syntax for accessing symbols in
236 this block (e.g. block['local_variable']).
240 | [COMMAND] | SHELL_COMMAND
241 | -d DELIM COMMAND DELIM SHELL_COMMAND
242 pipe [COMMAND] | SHELL_COMMAND
243 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
244 Executes COMMAND and sends its output to SHELL_COMMAND.
245 With no COMMAND, repeat the last executed command
246 and send its output to SHELL_COMMAND.
248 define-prefix COMMAND
249 Define or mark a command as a user-defined prefix command.
251 with SETTING [VALUE] [-- COMMAND]
252 w SETTING [VALUE] [-- COMMAND]
253 Temporarily set SETTING, run COMMAND, and restore SETTING.
254 Usage: with SETTING -- COMMAND
255 With no COMMAND, repeats the last executed command.
256 SETTING is any GDB setting you can change with the "set"
257 subcommands. For example, 'with language c -- print someobj'
258 temporarily switches to the C language in order to print someobj.
259 Settings can be combined: 'w lang c -- w print elements unlimited --
260 usercmd' switches to the C language and runs usercmd with no limit
261 of array elements to print.
263 maint with SETTING [VALUE] [-- COMMAND]
264 Like "with", but works with "maintenance set" settings.
266 set may-call-functions [on|off]
267 show may-call-functions
268 This controls whether GDB will attempt to call functions in
269 the program, such as with expressions in the print command. It
270 defaults to on. Calling functions in the program being debugged
271 can have undesired side effects. It is now possible to forbid
272 such function calls. If function calls are forbidden, GDB will throw
273 an error when a command (such as print expression) calls a function
276 set print finish [on|off]
278 This controls whether the `finish' command will display the value
279 that is returned by the current function. When `off', the value is
280 still entered into the value history, but it is not printed. The
285 Allows deeply nested structures to be simplified when printing by
286 replacing deeply nested parts (beyond the max-depth) with ellipses.
287 The default max-depth is 20, but this can be set to unlimited to get
288 the old behavior back.
290 set print raw-values [on|off]
291 show print raw-values
292 By default, GDB applies the enabled pretty printers when printing a
293 value. This allows to ignore the enabled pretty printers for a series
294 of commands. The default is 'off'.
296 set logging debugredirect [on|off]
297 By default, GDB debug output will go to both the terminal and the logfile.
298 Set if you want debug output to go only to the log file.
300 set style title foreground COLOR
301 set style title background COLOR
302 set style title intensity VALUE
303 Control the styling of titles.
305 set style highlight foreground COLOR
306 set style highlight background COLOR
307 set style highlight intensity VALUE
308 Control the styling of highlightings.
310 maint set worker-threads
311 maint show worker-threads
312 Control the number of worker threads that can be used by GDB. The
313 default is 0. "unlimited" lets GDB choose a number that is
314 reasonable. Currently worker threads are only used when demangling
315 the names of linker symbols.
317 set style tui-border foreground COLOR
318 set style tui-border background COLOR
319 Control the styling of TUI borders.
321 set style tui-active-border foreground COLOR
322 set style tui-active-border background COLOR
323 Control the styling of the active TUI border.
325 maint set test-settings KIND
326 maint show test-settings KIND
327 A set of commands used by the testsuite for exercising the settings
330 maint set tui-resize-message [on|off]
331 maint show tui-resize-message
332 Control whether GDB prints a message each time the terminal is
333 resized when in TUI mode. This is primarily useful for testing the
336 set print frame-info [short-location|location|location-and-address
337 |source-and-location|source-line|auto]
338 show print frame-info
339 This controls what frame information is printed by the commands printing
340 a frame. This setting will e.g. influence the behaviour of 'backtrace',
341 'frame', 'stepi'. The python frame filtering also respect this setting.
342 The 'backtrace' '-frame-info' option can override this global setting.
344 set tui compact-source
345 show tui compact-source
347 Enable the "compact" display mode for the TUI source window. The
348 compact display uses only as much space as is needed for the line
349 numbers in the current file, and only a single space to separate the
350 line numbers from the source.
352 info modules [-q] [REGEXP]
353 Return a list of Fortran modules matching REGEXP, or all modules if
356 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
357 Return a list of functions within all modules, grouped by module.
358 The list of functions can be restricted with the optional regular
359 expressions. MODULE_REGEXP matches against the module name,
360 TYPE_REGEXP matches against the function type signature, and REGEXP
361 matches against the function name.
363 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
364 Return a list of variables within all modules, grouped by module.
365 The list of variables can be restricted with the optional regular
366 expressions. MODULE_REGEXP matches against the module name,
367 TYPE_REGEXP matches against the variable type, and REGEXP matches
368 against the variable name.
370 set debug remote-packet-max-chars
371 show debug remote-packet-max-chars
372 Controls the number of characters to output in a remote packet when using
374 The default is 512 bytes.
377 Lists the target connections currently in use.
382 The "help" command uses the title style to enhance the
383 readibility of its output by styling the classes and
387 Similarly to "help", the "apropos" command also uses the
388 title style for the command names. "apropos" accepts now
389 a flag "-v" (verbose) to show the full documentation
390 of matching commands and to use the highlight style to mark
391 the documentation parts matching REGEXP.
395 The GDB printf and eval commands can now print C-style and Ada-style
396 string convenience variables without calling functions in the program.
397 This allows to do formatted printing of strings without having
398 a running inferior, or when debugging a core dump.
400 info sources [-dirname | -basename] [--] [REGEXP]
401 This command has now optional arguments to only print the files
402 whose names match REGEXP. The arguments -dirname and -basename
403 allow to restrict matching respectively to the dirname and basename
407 The "show style" and its subcommands are now styling
408 a style name in their output using its own style, to help
409 the user visualize the different styles.
411 set print frame-arguments
412 The new value 'presence' indicates to only indicate the presence of
413 arguments using ..., instead of printing argument names and values.
415 set print raw-frame-arguments
416 show print raw-frame-arguments
418 These commands replace the similarly-named "set/show print raw
419 frame-arguments" commands (now with a dash instead of a space). The
420 old commands are now deprecated and may be removed in a future
423 add-inferior [-no-connection]
424 The add-inferior command now supports a "-no-connection" flag that
425 makes the new inferior start with no target connection associated.
426 By default, the new inferior inherits the target connection of the
427 current inferior. See also "info connections".
430 This command's output now includes a new "Connection" column
431 indicating which target connection an inferior is bound to. See
432 "info connections" above.
434 maint test-options require-delimiter
435 maint test-options unknown-is-error
436 maint test-options unknown-is-operand
437 maint show test-options-completion-result
438 Commands used by the testsuite to validate the command options
441 focus, winheight, +, -, >, <
442 These commands are now case-sensitive.
444 * New command options, command completion
446 GDB now has a standard infrastructure to support dash-style command
447 options ('-OPT'). One benefit is that commands that use it can
448 easily support completion of command line arguments. Try "CMD
449 -[TAB]" or "help CMD" to find options supported by a command. Over
450 time, we intend to migrate most commands to this infrastructure. A
451 number of commands got support for new command options in this
454 ** The "print" and "compile print" commands now support a number of
455 options that allow overriding relevant global print settings as
456 set by "set print" subcommands:
460 -array-indexes [on|off]
461 -elements NUMBER|unlimited
466 -repeats NUMBER|unlimited
467 -static-members [on|off]
472 Note that because the "print"/"compile print" commands accept
473 arbitrary expressions which may look like options (including
474 abbreviations), if you specify any command option, then you must
475 use a double dash ("--") to mark the end of argument processing.
477 ** The "backtrace" command now supports a number of options that
478 allow overriding relevant global print settings as set by "set
479 backtrace" and "set print" subcommands:
481 -entry-values no|only|preferred|if-needed|both|compact|default
482 -frame-arguments all|scalars|none
483 -raw-frame-arguments [on|off]
484 -frame-info auto|source-line|location|source-and-location
485 |location-and-address|short-location
489 In addition, the full/no-filters/hide qualifiers are now also
490 exposed as command options too:
496 ** The "frame apply", "tfaas" and "faas" commands similarly now
497 support the following options:
502 ** The new "info sources" options -dirname and -basename options
503 are using the standard '-OPT' infrastructure.
505 All options above can also be abbreviated. The argument of boolean
506 (on/off) options can be 0/1 too, and also the argument is assumed
507 "on" if omitted. This allows writing compact command invocations,
510 (gdb) p -ra -p -o 0 -- *myptr
512 The above is equivalent to:
514 (gdb) print -raw-values -pretty -object off -- *myptr
516 ** The "info types" command now supports the '-q' flag to disable
517 printing of some header information in a similar fashion to "info
518 variables" and "info functions".
520 ** The "info variables", "info functions", and "whereis" commands
521 now take a '-n' flag that excludes non-debug symbols (symbols
522 from the symbol table, not from the debug info such as DWARF)
525 * Completion improvements
527 ** GDB can now complete the options of the "thread apply all" and
528 "taas" commands, and their "-ascending" option can now be
531 ** GDB can now complete the options of the "info threads", "info
532 functions", "info variables", "info locals", and "info args"
535 ** GDB can now complete the options of the "compile file" and
536 "compile code" commands. The "compile file" command now
537 completes on filenames.
539 ** GDB can now complete the backtrace command's
540 "full/no-filters/hide" qualifiers.
542 * In settings, you can now abbreviate "unlimited".
544 E.g., "set print elements u" is now equivalent to "set print
550 This lists all the possible completions for the rest of the line, if it
551 were to be given as a command itself. This is intended for use by MI
552 frontends in cases when separate CLI and MI channels cannot be used.
554 -catch-throw, -catch-rethrow, and -catch-catch
555 These can be used to catch C++ exceptions in a similar fashion to
556 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
558 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
559 These commands are the MI equivalent of the CLI commands 'info
560 functions', 'info types', and 'info variables' respectively.
562 -symbol-info-modules, this is the MI equivalent of the CLI 'info
565 -symbol-info-module-functions and -symbol-info-module-variables.
566 These commands are the MI equivalent of the CLI commands 'info
567 module functions' and 'info module variables'.
571 ** The default version of the MI interpreter is now 3 (-i=mi3).
573 ** The output of information about multi-location breakpoints (which is
574 syntactically incorrect in MI 2) has changed in MI 3. This affects
575 the following commands and events:
579 - =breakpoint-created
580 - =breakpoint-modified
582 The -fix-multi-location-breakpoint-output command can be used to enable
583 this behavior with previous MI versions.
585 ** Backtraces and frames include a new optional field addr_flags which is
586 given after the addr field. On AArch64 this contains PAC if the address
587 has been masked in the frame. On all other targets the field is not
592 The testsuite now creates the files gdb.cmd (containing the arguments
593 used to launch GDB) and gdb.in (containing all the commands sent to
594 GDB) in the output directory for each test script. Multiple invocations
595 are appended with .1, .2, .3 etc.
597 * Building GDB and GDBserver now requires GNU make >= 3.82.
599 Using another implementation of the make program or an earlier version of
600 GNU make to build GDB or GDBserver is not supported.
602 * Building GDB now requires GNU readline >= 7.0.
604 GDB now bundles GNU readline 8.0, but if you choose to use
605 --with-system-readline, only readline >= 7.0 can be used.
607 * The TUI SingleKey keymap is now named "SingleKey". This can be used
608 from .inputrc to bind keys in this keymap. This feature is only
609 available when gdb is built against GNU readline 8.0 or later.
611 * Removed targets and native configurations
613 GDB no longer supports debugging the Cell Broadband Engine. This includes
614 both debugging standalone Cell/B.E. SPU applications and integrated debugging
615 of Cell/B.E. applications that use both the PPU and SPU architectures.
621 * Removed targets and native configurations
623 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
626 *** Changes in GDB 8.3
628 * GDB and GDBserver now support access to additional registers on
629 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
632 * GDB now has experimental support for the compilation and injection of
633 C++ source code into the inferior. This beta release does not include
634 support for several language features, such as templates, constructors,
637 This feature requires GCC 7.1 or higher built with libcp1.so
640 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
641 can be passed using the '[ADDRESS]:PORT' notation, or the regular
642 'ADDRESS:PORT' method.
644 * DWARF index cache: GDB can now automatically save indices of DWARF
645 symbols on disk to speed up further loading of the same binaries.
647 * Ada task switching is now supported on aarch64-elf targets when
648 debugging a program using the Ravenscar Profile. For more information,
649 see the "Tasking Support when using the Ravenscar Profile" section
650 in the GDB user manual.
652 * GDB in batch mode now exits with status 1 if the last command to be
655 * The RISC-V target now supports target descriptions.
657 * System call catchpoints now support system call aliases on FreeBSD.
658 When the ABI of a system call changes in FreeBSD, this is
659 implemented by leaving a compatibility system call using the old ABI
660 at the existing number and allocating a new system call number for
661 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
662 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
663 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
664 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
665 so that a system call catchpoint for the 'kevent' system call will
666 catch invocations of both the 'kevent' and 'freebsd11_kevent'
667 binaries. This ensures that 'kevent' system calls are caught for
668 binaries using either the old or new ABIs.
670 * Terminal styling is now available for the CLI and the TUI. GNU
671 Source Highlight can additionally be used to provide styling of
672 source code snippets. See the "set style" commands, below, for more
675 * Removed support for old demangling styles arm, edg, gnu, hp and
680 set debug compile-cplus-types
681 show debug compile-cplus-types
682 Control the display of debug output about type conversion in the
683 C++ compile feature. Commands have no effect while compiling
688 Control whether debug output about files/functions skipping is
691 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
692 Apply a command to some frames.
693 FLAG arguments allow to control what output to produce and how to handle
694 errors raised when applying COMMAND to a frame.
697 Apply a command to all threads (ignoring errors and empty output).
698 Shortcut for 'thread apply all -s COMMAND'.
701 Apply a command to all frames (ignoring errors and empty output).
702 Shortcut for 'frame apply all -s COMMAND'.
705 Apply a command to all frames of all threads (ignoring errors and empty
707 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
709 maint set dwarf unwinders (on|off)
710 maint show dwarf unwinders
711 Control whether DWARF unwinders can be used.
714 Display a list of open files for a process.
718 Changes to the "frame", "select-frame", and "info frame" CLI commands.
719 These commands all now take a frame specification which
720 is either a frame level, or one of the keywords 'level', 'address',
721 'function', or 'view' followed by a parameter. Selecting a frame by
722 address, or viewing a frame outside the current backtrace now
723 requires the use of a keyword. Selecting a frame by level is
724 unchanged. The MI comment "-stack-select-frame" is unchanged.
726 target remote FILENAME
727 target extended-remote FILENAME
728 If FILENAME is a Unix domain socket, GDB will attempt to connect
729 to this socket instead of opening FILENAME as a character device.
731 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
732 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
733 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
734 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
735 These commands can now print only the searched entities
736 matching the provided regexp(s), giving a condition
737 on the entity names or entity types. The flag -q disables
738 printing headers or informations messages.
744 These commands now determine the syntax for the shown entities
745 according to the language chosen by `set language'. In particular,
746 `set language auto' means to automatically choose the language of
749 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
750 The 'thread apply' command accepts new FLAG arguments.
751 FLAG arguments allow to control what output to produce and how to handle
752 errors raised when applying COMMAND to a thread.
754 set tui tab-width NCHARS
755 show tui tab-width NCHARS
756 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
758 set style enabled [on|off]
760 Enable or disable terminal styling. Styling is enabled by default
761 on most hosts, but disabled by default when in batch mode.
763 set style sources [on|off]
765 Enable or disable source code styling. Source code styling is
766 enabled by default, but only takes effect if styling in general is
767 enabled, and if GDB was linked with GNU Source Highlight.
769 set style filename foreground COLOR
770 set style filename background COLOR
771 set style filename intensity VALUE
772 Control the styling of file names.
774 set style function foreground COLOR
775 set style function background COLOR
776 set style function intensity VALUE
777 Control the styling of function names.
779 set style variable foreground COLOR
780 set style variable background COLOR
781 set style variable intensity VALUE
782 Control the styling of variable names.
784 set style address foreground COLOR
785 set style address background COLOR
786 set style address intensity VALUE
787 Control the styling of addresses.
791 ** The '-data-disassemble' MI command now accepts an '-a' option to
792 disassemble the whole function surrounding the given program
793 counter value or function name. Support for this feature can be
794 verified by using the "-list-features" command, which should
795 contain "data-disassemble-a-option".
797 ** Command responses and notifications that include a frame now include
798 the frame's architecture in a new "arch" attribute.
800 * New native configurations
802 GNU/Linux/RISC-V riscv*-*-linux*
803 FreeBSD/riscv riscv*-*-freebsd*
807 GNU/Linux/RISC-V riscv*-*-linux*
809 CSKY GNU/LINUX csky*-*-linux
810 FreeBSD/riscv riscv*-*-freebsd*
812 GNU/Linux/OpenRISC or1k*-*-linux*
816 GDB no longer supports native debugging on versions of MS-Windows
821 ** GDB no longer supports Python versions less than 2.6.
823 ** The gdb.Inferior type has a new 'progspace' property, which is the program
824 space associated to that inferior.
826 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
827 of objfiles associated to that program space.
829 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
830 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
833 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
834 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
835 correct and did not work properly.
837 ** The gdb.Value type has a new constructor, which is used to construct a
838 gdb.Value from a Python buffer object and a gdb.Type.
844 Enable or disable the undefined behavior sanitizer. This is
845 disabled by default, but passing --enable-ubsan=yes or
846 --enable-ubsan=auto to configure will enable it. Enabling this can
847 cause a performance penalty. The undefined behavior sanitizer was
848 first introduced in GCC 4.9.
850 *** Changes in GDB 8.2
852 * The 'set disassembler-options' command now supports specifying options
855 * The 'symbol-file' command now accepts an '-o' option to add a relative
856 offset to all sections.
858 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
859 a relative offset to all sections, but it allows to override the load
860 address of individual sections using '-s'.
862 * The 'add-symbol-file' command no longer requires the second argument
863 (address of the text section).
865 * The endianness used with the 'set endian auto' mode in the absence of
866 an executable selected for debugging is now the last endianness chosen
867 either by one of the 'set endian big' and 'set endian little' commands
868 or by inferring from the last executable used, rather than the startup
871 * The pager now allows a "c" response, meaning to disable the pager
872 for the rest of the current command.
874 * The commands 'info variables/functions/types' now show the source line
875 numbers of symbol definitions when available.
877 * 'info proc' now works on running processes on FreeBSD systems and core
878 files created on FreeBSD systems.
880 * C expressions can now use _Alignof, and C++ expressions can now use
883 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
884 the vector length while the process is running.
890 Control display of debugging info regarding the FreeBSD native target.
892 set|show varsize-limit
893 This new setting allows the user to control the maximum size of Ada
894 objects being printed when those objects have a variable type,
895 instead of that maximum size being hardcoded to 65536 bytes.
897 set|show record btrace cpu
898 Controls the processor to be used for enabling errata workarounds for
901 maint check libthread-db
902 Run integrity checks on the current inferior's thread debugging
905 maint set check-libthread-db (on|off)
906 maint show check-libthread-db
907 Control whether to run integrity checks on inferior specific thread
908 debugging libraries as they are loaded. The default is not to
913 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
915 ** The commands attached to a breakpoint can be set by assigning to
916 the breakpoint's "commands" field.
918 ** gdb.execute can now execute multi-line gdb commands.
920 ** The new functions gdb.convenience_variable and
921 gdb.set_convenience_variable can be used to get and set the value
922 of convenience variables.
924 ** A gdb.Parameter will no longer print the "set" help text on an
925 ordinary "set"; instead by default a "set" will be silent unless
926 the get_set_string method returns a non-empty string.
930 RiscV ELF riscv*-*-elf
932 * Removed targets and native configurations
934 m88k running OpenBSD m88*-*-openbsd*
935 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
936 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
937 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
939 * Aarch64/Linux hardware watchpoints improvements
941 Hardware watchpoints on unaligned addresses are now properly
942 supported when running Linux kernel 4.10 or higher: read and access
943 watchpoints are no longer spuriously missed, and all watchpoints
944 lengths between 1 and 8 bytes are supported. On older kernels,
945 watchpoints set on unaligned addresses are no longer missed, with
946 the tradeoff that there is a possibility of false hits being
951 --enable-codesign=CERT
952 This can be used to invoke "codesign -s CERT" after building gdb.
953 This option is useful on macOS, where code signing is required for
954 gdb to work properly.
956 --disable-gdbcli has been removed
957 This is now silently accepted, but does nothing.
959 *** Changes in GDB 8.1
961 * GDB now supports dynamically creating arbitrary register groups specified
962 in XML target descriptions. This allows for finer grain grouping of
963 registers on systems with a large amount of registers.
965 * The 'ptype' command now accepts a '/o' flag, which prints the
966 offsets and sizes of fields in a struct, like the pahole(1) tool.
968 * New "--readnever" command line option instructs GDB to not read each
969 symbol file's symbolic debug information. This makes startup faster
970 but at the expense of not being able to perform symbolic debugging.
971 This option is intended for use cases where symbolic debugging will
972 not be used, e.g., when you only need to dump the debuggee's core.
974 * GDB now uses the GNU MPFR library, if available, to emulate target
975 floating-point arithmetic during expression evaluation when the target
976 uses different floating-point formats than the host. At least version
977 3.1 of GNU MPFR is required.
979 * GDB now supports access to the guarded-storage-control registers and the
980 software-based guarded-storage broadcast control registers on IBM z14.
982 * On Unix systems, GDB now supports transmitting environment variables
983 that are to be set or unset to GDBserver. These variables will
984 affect the environment to be passed to the remote inferior.
986 To inform GDB of environment variables that are to be transmitted to
987 GDBserver, use the "set environment" command. Only user set
988 environment variables are sent to GDBserver.
990 To inform GDB of environment variables that are to be unset before
991 the remote inferior is started by the GDBserver, use the "unset
992 environment" command.
994 * Completion improvements
996 ** GDB can now complete function parameters in linespecs and
997 explicit locations without quoting. When setting breakpoints,
998 quoting around functions names to help with TAB-completion is
999 generally no longer necessary. For example, this now completes
1002 (gdb) b function(in[TAB]
1003 (gdb) b function(int)
1005 Related, GDB is no longer confused with completing functions in
1006 C++ anonymous namespaces:
1009 (gdb) b (anonymous namespace)::[TAB][TAB]
1010 (anonymous namespace)::a_function()
1011 (anonymous namespace)::b_function()
1013 ** GDB now has much improved linespec and explicit locations TAB
1014 completion support, that better understands what you're
1015 completing and offers better suggestions. For example, GDB no
1016 longer offers data symbols as possible completions when you're
1017 setting a breakpoint.
1019 ** GDB now TAB-completes label symbol names.
1021 ** The "complete" command now mimics TAB completion accurately.
1023 * New command line options (gcore)
1026 Dump all memory mappings.
1028 * Breakpoints on C++ functions are now set on all scopes by default
1030 By default, breakpoints on functions/methods are now interpreted as
1031 specifying all functions with the given name ignoring missing
1032 leading scopes (namespaces and classes).
1034 For example, assuming a C++ program with symbols named:
1039 both commands "break func()" and "break B::func()" set a breakpoint
1042 You can use the new flag "-qualified" to override this. This makes
1043 GDB interpret the specified function name as a complete
1044 fully-qualified name instead. For example, using the same C++
1045 program, the "break -q B::func" command sets a breakpoint on
1046 "B::func", only. A parameter has been added to the Python
1047 gdb.Breakpoint constructor to achieve the same result when creating
1048 a breakpoint from Python.
1050 * Breakpoints on functions marked with C++ ABI tags
1052 GDB can now set breakpoints on functions marked with C++ ABI tags
1053 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1054 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1056 Functions with a C++11 abi tag are demangled/displayed like this:
1058 function[abi:cxx11](int)
1061 You can now set a breakpoint on such functions simply as if they had
1064 (gdb) b function(int)
1066 Or if you need to disambiguate between tags, like:
1068 (gdb) b function[abi:other_tag](int)
1070 Tab completion was adjusted accordingly as well.
1074 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1075 gdb.new_thread are emitted. See the manual for further
1076 description of these.
1078 ** A new function, "gdb.rbreak" has been added to the Python API.
1079 This function allows the setting of a large number of breakpoints
1080 via a regex pattern in Python. See the manual for further details.
1082 ** Python breakpoints can now accept explicit locations. See the
1083 manual for a further description of this feature.
1086 * New features in the GDB remote stub, GDBserver
1088 ** GDBserver is now able to start inferior processes with a
1089 specified initial working directory.
1091 The user can set the desired working directory to be used from
1092 GDB using the new "set cwd" command.
1094 ** New "--selftest" command line option runs some GDBserver self
1095 tests. These self tests are disabled in releases.
1097 ** On Unix systems, GDBserver now does globbing expansion and variable
1098 substitution in inferior command line arguments.
1100 This is done by starting inferiors using a shell, like GDB does.
1101 See "set startup-with-shell" in the user manual for how to disable
1102 this from GDB when using "target extended-remote". When using
1103 "target remote", you can disable the startup with shell by using the
1104 new "--no-startup-with-shell" GDBserver command line option.
1106 ** On Unix systems, GDBserver now supports receiving environment
1107 variables that are to be set or unset from GDB. These variables
1108 will affect the environment to be passed to the inferior.
1110 * When catching an Ada exception raised with a message, GDB now prints
1111 the message in the catchpoint hit notification. In GDB/MI mode, that
1112 information is provided as an extra field named "exception-message"
1113 in the *stopped notification.
1115 * Trait objects can now be inspected When debugging Rust code. This
1116 requires compiler support which will appear in Rust 1.24.
1118 * New remote packets
1120 QEnvironmentHexEncoded
1121 Inform GDBserver of an environment variable that is to be passed to
1122 the inferior when starting it.
1125 Inform GDBserver of an environment variable that is to be unset
1126 before starting the remote inferior.
1129 Inform GDBserver that the environment should be reset (i.e.,
1130 user-set environment variables should be unset).
1133 Indicates whether the inferior must be started with a shell or not.
1136 Tell GDBserver that the inferior to be started should use a specific
1139 * The "maintenance print c-tdesc" command now takes an optional
1140 argument which is the file name of XML target description.
1142 * The "maintenance selftest" command now takes an optional argument to
1143 filter the tests to be run.
1145 * The "enable", and "disable" commands now accept a range of
1146 breakpoint locations, e.g. "enable 1.3-5".
1151 Set and show the current working directory for the inferior.
1153 set|show compile-gcc
1154 Set and show compilation command used for compiling and injecting code
1155 with the 'compile' commands.
1157 set debug separate-debug-file
1158 show debug separate-debug-file
1159 Control the display of debug output about separate debug file search.
1161 set dump-excluded-mappings
1162 show dump-excluded-mappings
1163 Control whether mappings marked with the VM_DONTDUMP flag should be
1164 dumped when generating a core file.
1166 maint info selftests
1167 List the registered selftests.
1170 Start the debugged program stopping at the first instruction.
1173 Control display of debugging messages related to OpenRISC targets.
1175 set|show print type nested-type-limit
1176 Set and show the limit of nesting level for nested types that the
1177 type printer will show.
1179 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1182 * Safer/improved support for debugging with no debug info
1184 GDB no longer assumes functions with no debug information return
1187 This means that GDB now refuses to call such functions unless you
1188 tell it the function's type, by either casting the call to the
1189 declared return type, or by casting the function to a function
1190 pointer of the right type, and calling that:
1192 (gdb) p getenv ("PATH")
1193 'getenv' has unknown return type; cast the call to its declared return type
1194 (gdb) p (char *) getenv ("PATH")
1195 $1 = 0x7fffffffe "/usr/local/bin:/"...
1196 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1197 $2 = 0x7fffffffe "/usr/local/bin:/"...
1199 Similarly, GDB no longer assumes that global variables with no debug
1200 info have type 'int', and refuses to print the variable's value
1201 unless you tell it the variable's type:
1204 'var' has unknown type; cast it to its declared type
1208 * New native configurations
1210 FreeBSD/aarch64 aarch64*-*-freebsd*
1211 FreeBSD/arm arm*-*-freebsd*
1215 FreeBSD/aarch64 aarch64*-*-freebsd*
1216 FreeBSD/arm arm*-*-freebsd*
1217 OpenRISC ELF or1k*-*-elf
1219 * Removed targets and native configurations
1221 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1223 *** Changes in GDB 8.0
1225 * GDB now supports access to the PKU register on GNU/Linux. The register is
1226 added by the Memory Protection Keys for Userspace feature which will be
1227 available in future Intel CPUs.
1229 * GDB now supports C++11 rvalue references.
1233 ** New functions to start, stop and access a running btrace recording.
1234 ** Rvalue references are now supported in gdb.Type.
1236 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1239 * Building GDB and GDBserver now requires a C++11 compiler.
1241 For example, GCC 4.8 or later.
1243 It is no longer possible to build GDB or GDBserver with a C
1244 compiler. The --disable-build-with-cxx configure option has been
1247 * Building GDB and GDBserver now requires GNU make >= 3.81.
1249 It is no longer supported to build GDB or GDBserver with another
1250 implementation of the make program or an earlier version of GNU make.
1252 * Native debugging on MS-Windows supports command-line redirection
1254 Command-line arguments used for starting programs on MS-Windows can
1255 now include redirection symbols supported by native Windows shells,
1256 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1257 as "run", "start", and "set args", as well as the corresponding MI
1260 * Support for thread names on MS-Windows.
1262 GDB now catches and handles the special exception that programs
1263 running on MS-Windows use to assign names to threads in the
1266 * Support for Java programs compiled with gcj has been removed.
1268 * User commands now accept an unlimited number of arguments.
1269 Previously, only up to 10 was accepted.
1271 * The "eval" command now expands user-defined command arguments.
1273 This makes it easier to process a variable number of arguments:
1278 eval "print $arg%d", $i
1283 * Target descriptions can now describe registers for sparc32 and sparc64.
1285 * GDB now supports DWARF version 5 (debug information format).
1286 Its .debug_names index is not yet supported.
1288 * New native configurations
1290 FreeBSD/mips mips*-*-freebsd
1294 Synopsys ARC arc*-*-elf32
1295 FreeBSD/mips mips*-*-freebsd
1297 * Removed targets and native configurations
1299 Alpha running FreeBSD alpha*-*-freebsd*
1300 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1305 Erases all the flash memory regions reported by the target.
1307 maint print arc arc-instruction address
1308 Print internal disassembler information about instruction at a given address.
1312 set disassembler-options
1313 show disassembler-options
1314 Controls the passing of target specific information to the disassembler.
1315 If it is necessary to specify more than one disassembler option then
1316 multiple options can be placed together into a comma separated list.
1317 The default value is the empty string. Currently, the only supported
1318 targets are ARM, PowerPC and S/390.
1323 Erases all the flash memory regions reported by the target. This is
1324 equivalent to the CLI command flash-erase.
1326 -file-list-shared-libraries
1327 List the shared libraries in the program. This is
1328 equivalent to the CLI command "info shared".
1331 Catchpoints stopping the program when Ada exceptions are
1332 handled. This is equivalent to the CLI command "catch handlers".
1334 *** Changes in GDB 7.12
1336 * GDB and GDBserver now build with a C++ compiler by default.
1338 The --enable-build-with-cxx configure option is now enabled by
1339 default. One must now explicitly configure with
1340 --disable-build-with-cxx in order to build with a C compiler. This
1341 option will be removed in a future release.
1343 * GDBserver now supports recording btrace without maintaining an active
1346 * GDB now supports a negative repeat count in the 'x' command to examine
1347 memory backward from the given address. For example:
1350 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1351 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1352 (gdb) x/-5i 0x0000000000400580
1353 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1354 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1355 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1356 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1357 0x40057b <main(int, char**)+25>:
1358 callq 0x400536 <Func1(int, char const*)>
1360 * Fortran: Support structures with fields of dynamic types and
1361 arrays of dynamic types.
1363 * The symbol dumping maintenance commands have new syntax.
1364 maint print symbols [-pc address] [--] [filename]
1365 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1366 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1367 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1368 maint print msymbols [-objfile objfile] [--] [filename]
1370 * GDB now supports multibit bitfields and enums in target register
1373 * New Python-based convenience function $_as_string(val), which returns
1374 the textual representation of a value. This function is especially
1375 useful to obtain the text label of an enum value.
1377 * Intel MPX bound violation handling.
1379 Segmentation faults caused by a Intel MPX boundary violation
1380 now display the kind of violation (upper or lower), the memory
1381 address accessed and the memory bounds, along with the usual
1382 signal received and code location.
1386 Program received signal SIGSEGV, Segmentation fault
1387 Upper bound violation while accessing address 0x7fffffffc3b3
1388 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1389 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1391 * Rust language support.
1392 GDB now supports debugging programs written in the Rust programming
1393 language. See https://www.rust-lang.org/ for more information about
1396 * Support for running interpreters on specified input/output devices
1398 GDB now supports a new mechanism that allows frontends to provide
1399 fully featured GDB console views, as a better alternative to
1400 building such views on top of the "-interpreter-exec console"
1401 command. See the new "new-ui" command below. With that command,
1402 frontends can now start GDB in the traditional command-line mode
1403 running in an embedded terminal emulator widget, and create a
1404 separate MI interpreter running on a specified i/o device. In this
1405 way, GDB handles line editing, history, tab completion, etc. in the
1406 console all by itself, and the GUI uses the separate MI interpreter
1407 for its own control and synchronization, invisible to the command
1410 * The "catch syscall" command catches groups of related syscalls.
1412 The "catch syscall" command now supports catching a group of related
1413 syscalls using the 'group:' or 'g:' prefix.
1418 skip -gfile file-glob-pattern
1419 skip -function function
1420 skip -rfunction regular-expression
1421 A generalized form of the skip command, with new support for
1422 glob-style file names and regular expressions for function names.
1423 Additionally, a file spec and a function spec may now be combined.
1425 maint info line-table REGEXP
1426 Display the contents of GDB's internal line table data structure.
1429 Run any GDB unit tests that were compiled in.
1432 Start a new user interface instance running INTERP as interpreter,
1433 using the TTY file for input/output.
1437 ** gdb.Breakpoint objects have a new attribute "pending", which
1438 indicates whether the breakpoint is pending.
1439 ** Three new breakpoint-related events have been added:
1440 gdb.breakpoint_created, gdb.breakpoint_modified, and
1441 gdb.breakpoint_deleted.
1443 signal-event EVENTID
1444 Signal ("set") the given MS-Windows event object. This is used in
1445 conjunction with the Windows JIT debugging (AeDebug) support, where
1446 the OS suspends a crashing process until a debugger can attach to
1447 it. Resuming the crashing process, in order to debug it, is done by
1448 signalling an event.
1450 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1451 was added in GDBserver, including JIT compiling fast tracepoint's
1452 conditional expression bytecode into native code.
1454 * Support for various remote target protocols and ROM monitors has
1457 target m32rsdi Remote M32R debugging over SDI
1458 target mips MIPS remote debugging protocol
1459 target pmon PMON ROM monitor
1460 target ddb NEC's DDB variant of PMON for Vr4300
1461 target rockhopper NEC RockHopper variant of PMON
1462 target lsi LSI variant of PMO
1464 * Support for tracepoints and fast tracepoints on powerpc-linux,
1465 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1466 including JIT compiling fast tracepoint's conditional expression
1467 bytecode into native code.
1469 * MI async record =record-started now includes the method and format used for
1470 recording. For example:
1472 =record-started,thread-group="i1",method="btrace",format="bts"
1474 * MI async record =thread-selected now includes the frame field. For example:
1476 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1480 Andes NDS32 nds32*-*-elf
1482 *** Changes in GDB 7.11
1484 * GDB now supports debugging kernel-based threads on FreeBSD.
1486 * Per-inferior thread numbers
1488 Thread numbers are now per inferior instead of global. If you're
1489 debugging multiple inferiors, GDB displays thread IDs using a
1490 qualified INF_NUM.THR_NUM form. For example:
1494 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1495 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1496 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1497 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1499 As consequence, thread numbers as visible in the $_thread
1500 convenience variable and in Python's InferiorThread.num attribute
1501 are no longer unique between inferiors.
1503 GDB now maintains a second thread ID per thread, referred to as the
1504 global thread ID, which is the new equivalent of thread numbers in
1505 previous releases. See also $_gthread below.
1507 For backwards compatibility, MI's thread IDs always refer to global
1510 * Commands that accept thread IDs now accept the qualified
1511 INF_NUM.THR_NUM form as well. For example:
1514 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1517 * In commands that accept a list of thread IDs, you can now refer to
1518 all threads of an inferior using a star wildcard. GDB accepts
1519 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1520 refer to all threads of the current inferior. For example, "info
1523 * You can use "info threads -gid" to display the global thread ID of
1526 * The new convenience variable $_gthread holds the global number of
1529 * The new convenience variable $_inferior holds the number of the
1532 * GDB now displays the ID and name of the thread that hit a breakpoint
1533 or received a signal, if your program is multi-threaded. For
1536 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1537 Thread 1 "main" received signal SIGINT, Interrupt.
1539 * Record btrace now supports non-stop mode.
1541 * Support for tracepoints on aarch64-linux was added in GDBserver.
1543 * The 'record instruction-history' command now indicates speculative execution
1544 when using the Intel Processor Trace recording format.
1546 * GDB now allows users to specify explicit locations, bypassing
1547 the linespec parser. This feature is also available to GDB/MI
1550 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1551 GDB now is able to debug both AArch64 applications and ARM applications
1554 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1555 including JIT compiling fast tracepoint's conditional expression bytecode
1558 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1560 * "info threads", "info inferiors", "info display", "info checkpoints"
1561 and "maint info program-spaces" now list the corresponding items in
1562 ascending ID order, for consistency with all other "info" commands.
1564 * In Ada, the overloads selection menu has been enhanced to display the
1565 parameter types and the return types for the matching overloaded subprograms.
1569 maint set target-non-stop (on|off|auto)
1570 maint show target-non-stop
1571 Control whether GDB targets always operate in non-stop mode even if
1572 "set non-stop" is "off". The default is "auto", meaning non-stop
1573 mode is enabled if supported by the target.
1575 maint set bfd-sharing
1576 maint show bfd-sharing
1577 Control the reuse of bfd objects.
1580 show debug bfd-cache
1581 Control display of debugging info regarding bfd caching.
1585 Control display of debugging info regarding FreeBSD threads.
1587 set remote multiprocess-extensions-packet
1588 show remote multiprocess-extensions-packet
1589 Set/show the use of the remote protocol multiprocess extensions.
1591 set remote thread-events
1592 show remote thread-events
1593 Set/show the use of thread create/exit events.
1595 set ada print-signatures on|off
1596 show ada print-signatures"
1597 Control whether parameter types and return types are displayed in overloads
1598 selection menus. It is activated (@code{on}) by default.
1602 Controls the maximum size of memory, in bytes, that GDB will
1603 allocate for value contents. Prevents incorrect programs from
1604 causing GDB to allocate overly large buffers. Default is 64k.
1606 * The "disassemble" command accepts a new modifier: /s.
1607 It prints mixed source+disassembly like /m with two differences:
1608 - disassembled instructions are now printed in program order, and
1609 - and source for all relevant files is now printed.
1610 The "/m" option is now considered deprecated: its "source-centric"
1611 output hasn't proved useful in practice.
1613 * The "record instruction-history" command accepts a new modifier: /s.
1614 It behaves exactly like /m and prints mixed source+disassembly.
1616 * The "set scheduler-locking" command supports a new mode "replay".
1617 It behaves like "off" in record mode and like "on" in replay mode.
1619 * Support for various ROM monitors has been removed:
1621 target dbug dBUG ROM monitor for Motorola ColdFire
1622 target picobug Motorola picobug monitor
1623 target dink32 DINK32 ROM monitor for PowerPC
1624 target m32r Renesas M32R/D ROM monitor
1625 target mon2000 mon2000 ROM monitor
1626 target ppcbug PPCBUG ROM monitor for PowerPC
1628 * Support for reading/writing memory and extracting values on architectures
1629 whose memory is addressable in units of any integral multiple of 8 bits.
1632 Allows to break when an Ada exception is handled.
1634 * New remote packets
1637 Indicates that an exec system call was executed.
1639 exec-events feature in qSupported
1640 The qSupported packet allows GDB to request support for exec
1641 events using the new 'gdbfeature' exec-event, and the qSupported
1642 response can contain the corresponding 'stubfeature'. Set and
1643 show commands can be used to display whether these features are enabled.
1646 Equivalent to interrupting with the ^C character, but works in
1649 thread created stop reason (T05 create:...)
1650 Indicates that the thread was just created and is stopped at entry.
1652 thread exit stop reply (w exitcode;tid)
1653 Indicates that the thread has terminated.
1656 Enables/disables thread create and exit event reporting. For
1657 example, this is used in non-stop mode when GDB stops a set of
1658 threads and synchronously waits for the their corresponding stop
1659 replies. Without exit events, if one of the threads exits, GDB
1660 would hang forever not knowing that it should no longer expect a
1661 stop for that same thread.
1664 Indicates that there are no resumed threads left in the target (all
1665 threads are stopped). The remote stub reports support for this stop
1666 reply to GDB's qSupported query.
1669 Enables/disables catching syscalls from the inferior process.
1670 The remote stub reports support for this packet to GDB's qSupported query.
1672 syscall_entry stop reason
1673 Indicates that a syscall was just called.
1675 syscall_return stop reason
1676 Indicates that a syscall just returned.
1678 * Extended-remote exec events
1680 ** GDB now has support for exec events on extended-remote Linux targets.
1681 For such targets with Linux kernels 2.5.46 and later, this enables
1682 follow-exec-mode and exec catchpoints.
1684 set remote exec-event-feature-packet
1685 show remote exec-event-feature-packet
1686 Set/show the use of the remote exec event feature.
1688 * Thread names in remote protocol
1690 The reply to qXfer:threads:read may now include a name attribute for each
1693 * Target remote mode fork and exec events
1695 ** GDB now has support for fork and exec events on target remote mode
1696 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1697 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1698 fork and exec catchpoints.
1700 * Remote syscall events
1702 ** GDB now has support for catch syscall on remote Linux targets,
1703 currently enabled on x86/x86_64 architectures.
1705 set remote catch-syscall-packet
1706 show remote catch-syscall-packet
1707 Set/show the use of the remote catch syscall feature.
1711 ** The -var-set-format command now accepts the zero-hexadecimal
1712 format. It outputs data in hexadecimal format with zero-padding on the
1717 ** gdb.InferiorThread objects have a new attribute "global_num",
1718 which refers to the thread's global thread ID. The existing
1719 "num" attribute now refers to the thread's per-inferior number.
1720 See "Per-inferior thread numbers" above.
1721 ** gdb.InferiorThread objects have a new attribute "inferior", which
1722 is the Inferior object the thread belongs to.
1724 *** Changes in GDB 7.10
1726 * Support for process record-replay and reverse debugging on aarch64*-linux*
1727 targets has been added. GDB now supports recording of A64 instruction set
1728 including advance SIMD instructions.
1730 * Support for Sun's version of the "stabs" debug file format has been removed.
1732 * GDB now honors the content of the file /proc/PID/coredump_filter
1733 (PID is the process ID) on GNU/Linux systems. This file can be used
1734 to specify the types of memory mappings that will be included in a
1735 corefile. For more information, please refer to the manual page of
1736 "core(5)". GDB also has a new command: "set use-coredump-filter
1737 on|off". It allows to set whether GDB will read the content of the
1738 /proc/PID/coredump_filter file when generating a corefile.
1740 * The "info os" command on GNU/Linux can now display information on
1742 "info os cpus" Listing of all cpus/cores on the system
1744 * GDB has two new commands: "set serial parity odd|even|none" and
1745 "show serial parity". These allows to set or show parity for the
1748 * The "info source" command now displays the producer string if it was
1749 present in the debug info. This typically includes the compiler version
1750 and may include things like its command line arguments.
1752 * The "info dll", an alias of the "info sharedlibrary" command,
1753 is now available on all platforms.
1755 * Directory names supplied to the "set sysroot" commands may be
1756 prefixed with "target:" to tell GDB to access shared libraries from
1757 the target system, be it local or remote. This replaces the prefix
1758 "remote:". The default sysroot has been changed from "" to
1759 "target:". "remote:" is automatically converted to "target:" for
1760 backward compatibility.
1762 * The system root specified by "set sysroot" will be prepended to the
1763 filename of the main executable (if reported to GDB as absolute by
1764 the operating system) when starting processes remotely, and when
1765 attaching to already-running local or remote processes.
1767 * GDB now supports automatic location and retrieval of executable
1768 files from remote targets. Remote debugging can now be initiated
1769 using only a "target remote" or "target extended-remote" command
1770 (no "set sysroot" or "file" commands are required). See "New remote
1773 * The "dump" command now supports verilog hex format.
1775 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1777 * On GNU/Linux, GDB and gdbserver are now able to access executable
1778 and shared library files without a "set sysroot" command when
1779 attaching to processes running in different mount namespaces from
1780 the debugger. This makes it possible to attach to processes in
1781 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1782 See "New remote packets" below.
1784 * The "tui reg" command now provides completion for all of the
1785 available register groups, including target specific groups.
1787 * The HISTSIZE environment variable is no longer read when determining
1788 the size of GDB's command history. GDB now instead reads the dedicated
1789 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1790 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1795 ** Memory ports can now be unbuffered.
1799 ** gdb.Objfile objects have a new attribute "username",
1800 which is the name of the objfile as specified by the user,
1801 without, for example, resolving symlinks.
1802 ** You can now write frame unwinders in Python.
1803 ** gdb.Type objects have a new method "optimized_out",
1804 returning optimized out gdb.Value instance of this type.
1805 ** gdb.Value objects have new methods "reference_value" and
1806 "const_value" which return a reference to the value and a
1807 "const" version of the value respectively.
1811 maint print symbol-cache
1812 Print the contents of the symbol cache.
1814 maint print symbol-cache-statistics
1815 Print statistics of symbol cache usage.
1817 maint flush-symbol-cache
1818 Flush the contents of the symbol cache.
1822 Start branch trace recording using Branch Trace Store (BTS) format.
1825 Evaluate expression by using the compiler and print result.
1829 Explicit commands for enabling and disabling tui mode.
1832 set mpx bound on i386 and amd64
1833 Support for bound table investigation on Intel MPX enabled applications.
1837 Start branch trace recording using Intel Processor Trace format.
1840 Print information about branch tracing internals.
1842 maint btrace packet-history
1843 Print the raw branch tracing data.
1845 maint btrace clear-packet-history
1846 Discard the stored raw branch tracing data.
1849 Discard all branch tracing data. It will be fetched and processed
1850 anew by the next "record" command.
1855 Renamed from "set debug dwarf2-die".
1856 show debug dwarf-die
1857 Renamed from "show debug dwarf2-die".
1859 set debug dwarf-read
1860 Renamed from "set debug dwarf2-read".
1861 show debug dwarf-read
1862 Renamed from "show debug dwarf2-read".
1864 maint set dwarf always-disassemble
1865 Renamed from "maint set dwarf2 always-disassemble".
1866 maint show dwarf always-disassemble
1867 Renamed from "maint show dwarf2 always-disassemble".
1869 maint set dwarf max-cache-age
1870 Renamed from "maint set dwarf2 max-cache-age".
1871 maint show dwarf max-cache-age
1872 Renamed from "maint show dwarf2 max-cache-age".
1874 set debug dwarf-line
1875 show debug dwarf-line
1876 Control display of debugging info regarding DWARF line processing.
1879 show max-completions
1880 Set the maximum number of candidates to be considered during
1881 completion. The default value is 200. This limit allows GDB
1882 to avoid generating large completion lists, the computation of
1883 which can cause the debugger to become temporarily unresponsive.
1885 set history remove-duplicates
1886 show history remove-duplicates
1887 Control the removal of duplicate history entries.
1889 maint set symbol-cache-size
1890 maint show symbol-cache-size
1891 Control the size of the symbol cache.
1893 set|show record btrace bts buffer-size
1894 Set and show the size of the ring buffer used for branch tracing in
1896 The obtained size may differ from the requested size. Use "info
1897 record" to see the obtained buffer size.
1899 set debug linux-namespaces
1900 show debug linux-namespaces
1901 Control display of debugging info regarding Linux namespaces.
1903 set|show record btrace pt buffer-size
1904 Set and show the size of the ring buffer used for branch tracing in
1905 Intel Processor Trace format.
1906 The obtained size may differ from the requested size. Use "info
1907 record" to see the obtained buffer size.
1909 maint set|show btrace pt skip-pad
1910 Set and show whether PAD packets are skipped when computing the
1913 * The command 'thread apply all' can now support new option '-ascending'
1914 to call its specified command for all threads in ascending order.
1916 * Python/Guile scripting
1918 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1919 special section named `.debug_gdb_scripts'.
1921 * New remote packets
1923 qXfer:btrace-conf:read
1924 Return the branch trace configuration for the current thread.
1926 Qbtrace-conf:bts:size
1927 Set the requested ring buffer size for branch tracing in BTS format.
1930 Enable Intel Processor Trace-based branch tracing for the current
1931 process. The remote stub reports support for this packet to GDB's
1934 Qbtrace-conf:pt:size
1935 Set the requested ring buffer size for branch tracing in Intel Processor
1939 Indicates a memory breakpoint instruction was executed, irrespective
1940 of whether it was GDB that planted the breakpoint or the breakpoint
1941 is hardcoded in the program. This is required for correct non-stop
1945 Indicates the target stopped for a hardware breakpoint. This is
1946 required for correct non-stop mode operation.
1949 Return information about files on the remote system.
1951 qXfer:exec-file:read
1952 Return the full absolute name of the file that was executed to
1953 create a process running on the remote system.
1956 Select the filesystem on which vFile: operations with filename
1957 arguments will operate. This is required for GDB to be able to
1958 access files on remote targets where the remote stub does not
1959 share a common filesystem with the inferior(s).
1962 Indicates that a fork system call was executed.
1965 Indicates that a vfork system call was executed.
1967 vforkdone stop reason
1968 Indicates that a vfork child of the specified process has executed
1969 an exec or exit, allowing the vfork parent to resume execution.
1971 fork-events and vfork-events features in qSupported
1972 The qSupported packet allows GDB to request support for fork and
1973 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1974 and the qSupported response can contain the corresponding
1975 'stubfeatures'. Set and show commands can be used to display
1976 whether these features are enabled.
1978 * Extended-remote fork events
1980 ** GDB now has support for fork events on extended-remote Linux
1981 targets. For targets with Linux kernels 2.5.60 and later, this
1982 enables follow-fork-mode and detach-on-fork for both fork and
1983 vfork, as well as fork and vfork catchpoints.
1985 * The info record command now shows the recording format and the
1986 branch tracing configuration for the current thread when using
1987 the btrace record target.
1988 For the BTS format, it shows the ring buffer size.
1990 * GDB now has support for DTrace USDT (Userland Static Defined
1991 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1993 * GDB now supports access to vector registers on S/390 GNU/Linux
1996 * Removed command line options
1998 -xdb HP-UX XDB compatibility mode.
2000 * Removed targets and native configurations
2002 HP/PA running HP-UX hppa*-*-hpux*
2003 Itanium running HP-UX ia64-*-hpux*
2005 * New configure options
2008 This configure option allows the user to build GDB with support for
2009 Intel Processor Trace (default: auto). This requires libipt.
2011 --with-libipt-prefix=PATH
2012 Specify the path to the version of libipt that GDB should use.
2013 $PATH/include should contain the intel-pt.h header and
2014 $PATH/lib should contain the libipt.so library.
2016 *** Changes in GDB 7.9.1
2020 ** Xmethods can now specify a result type.
2022 *** Changes in GDB 7.9
2024 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2028 ** You can now access frame registers from Python scripts.
2029 ** New attribute 'producer' for gdb.Symtab objects.
2030 ** gdb.Objfile objects have a new attribute "progspace",
2031 which is the gdb.Progspace object of the containing program space.
2032 ** gdb.Objfile objects have a new attribute "owner".
2033 ** gdb.Objfile objects have a new attribute "build_id",
2034 which is the build ID generated when the file was built.
2035 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2036 ** A new event "gdb.clear_objfiles" has been added, triggered when
2037 selecting a new file to debug.
2038 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2039 ** New function gdb.lookup_objfile.
2041 New events which are triggered when GDB modifies the state of the
2044 ** gdb.events.inferior_call_pre: Function call is about to be made.
2045 ** gdb.events.inferior_call_post: Function call has just been made.
2046 ** gdb.events.memory_changed: A memory location has been altered.
2047 ** gdb.events.register_changed: A register has been altered.
2049 * New Python-based convenience functions:
2051 ** $_caller_is(name [, number_of_frames])
2052 ** $_caller_matches(regexp [, number_of_frames])
2053 ** $_any_caller_is(name [, number_of_frames])
2054 ** $_any_caller_matches(regexp [, number_of_frames])
2056 * GDB now supports the compilation and injection of source code into
2057 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2058 to compile the source code to object code, and if successful, inject
2059 and execute that code within the current context of the inferior.
2060 Currently the C language is supported. The commands used to
2061 interface with this new feature are:
2063 compile code [-raw|-r] [--] [source code]
2064 compile file [-raw|-r] filename
2068 demangle [-l language] [--] name
2069 Demangle "name" in the specified language, or the current language
2070 if elided. This command is renamed from the "maint demangle" command.
2071 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2072 as "maint demangler-warning".
2074 queue-signal signal-name-or-number
2075 Queue a signal to be delivered to the thread when it is resumed.
2077 add-auto-load-scripts-directory directory
2078 Add entries to the list of directories from which to load auto-loaded
2081 maint print user-registers
2082 List all currently available "user" registers.
2084 compile code [-r|-raw] [--] [source code]
2085 Compile, inject, and execute in the inferior the executable object
2086 code produced by compiling the provided source code.
2088 compile file [-r|-raw] filename
2089 Compile and inject into the inferior the executable object code
2090 produced by compiling the source code stored in the filename
2093 * On resume, GDB now always passes the signal the program had stopped
2094 for to the thread the signal was sent to, even if the user changed
2095 threads before resuming. Previously GDB would often (but not
2096 always) deliver the signal to the thread that happens to be current
2099 * Conversely, the "signal" command now consistently delivers the
2100 requested signal to the current thread. GDB now asks for
2101 confirmation if the program had stopped for a signal and the user
2102 switched threads meanwhile.
2104 * "breakpoint always-inserted" modes "off" and "auto" merged.
2106 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2107 won't remove breakpoints from the target until all threads stop,
2108 even in non-stop mode. The "auto" mode has been removed, and "off"
2109 is now the default mode.
2113 set debug symbol-lookup
2114 show debug symbol-lookup
2115 Control display of debugging info regarding symbol lookup.
2119 ** The -list-thread-groups command outputs an exit-code field for
2120 inferiors that have exited.
2124 MIPS SDE mips*-sde*-elf*
2128 Support for these obsolete configurations has been removed.
2130 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2131 SGI Irix-5.x mips-*-irix5*
2132 SGI Irix-6.x mips-*-irix6*
2133 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2134 VAX running Ultrix vax-*-ultrix*
2136 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2137 and "assf"), have been removed. Use the "sharedlibrary" command, or
2138 its alias "share", instead.
2140 *** Changes in GDB 7.8
2142 * New command line options
2145 This is an alias for the --data-directory option.
2147 * GDB supports printing and modifying of variable length automatic arrays
2148 as specified in ISO C99.
2150 * The ARM simulator now supports instruction level tracing
2151 with or without disassembly.
2155 GDB now has support for scripting using Guile. Whether this is
2156 available is determined at configure time.
2157 Guile version 2.0 or greater is required.
2158 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2160 * New commands (for set/show, see "New options" below)
2164 Invoke CODE by passing it to the Guile interpreter.
2168 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2170 info auto-load guile-scripts [regexp]
2171 Print the list of automatically loaded Guile scripts.
2173 * The source command is now capable of sourcing Guile scripts.
2174 This feature is dependent on the debugger being built with Guile support.
2178 set print symbol-loading (off|brief|full)
2179 show print symbol-loading
2180 Control whether to print informational messages when loading symbol
2181 information for a file. The default is "full", but when debugging
2182 programs with large numbers of shared libraries the amount of output
2183 becomes less useful.
2185 set guile print-stack (none|message|full)
2186 show guile print-stack
2187 Show a stack trace when an error is encountered in a Guile script.
2189 set auto-load guile-scripts (on|off)
2190 show auto-load guile-scripts
2191 Control auto-loading of Guile script files.
2193 maint ada set ignore-descriptive-types (on|off)
2194 maint ada show ignore-descriptive-types
2195 Control whether the debugger should ignore descriptive types in Ada
2196 programs. The default is not to ignore the descriptive types. See
2197 the user manual for more details on descriptive types and the intended
2198 usage of this option.
2200 set auto-connect-native-target
2202 Control whether GDB is allowed to automatically connect to the
2203 native target for the run, attach, etc. commands when not connected
2204 to any target yet. See also "target native" below.
2206 set record btrace replay-memory-access (read-only|read-write)
2207 show record btrace replay-memory-access
2208 Control what memory accesses are allowed during replay.
2210 maint set target-async (on|off)
2211 maint show target-async
2212 This controls whether GDB targets operate in synchronous or
2213 asynchronous mode. Normally the default is asynchronous, if it is
2214 available; but this can be changed to more easily debug problems
2215 occurring only in synchronous mode.
2217 set mi-async (on|off)
2219 Control whether MI asynchronous mode is preferred. This supersedes
2220 "set target-async" of previous GDB versions.
2222 * "set target-async" is deprecated as a CLI option and is now an alias
2223 for "set mi-async" (only puts MI into async mode).
2225 * Background execution commands (e.g., "c&", "s&", etc.) are now
2226 possible ``out of the box'' if the target supports them. Previously
2227 the user would need to explicitly enable the possibility with the
2228 "set target-async on" command.
2230 * New features in the GDB remote stub, GDBserver
2232 ** New option --debug-format=option1[,option2,...] allows one to add
2233 additional text to each output. At present only timestamps
2234 are supported: --debug-format=timestamps.
2235 Timestamps can also be turned on with the
2236 "monitor set debug-format timestamps" command from GDB.
2238 * The 'record instruction-history' command now starts counting instructions
2239 at one. This also affects the instruction ranges reported by the
2240 'record function-call-history' command when given the /i modifier.
2242 * The command 'record function-call-history' supports a new modifier '/c' to
2243 indent the function names based on their call stack depth.
2244 The fields for the '/i' and '/l' modifier have been reordered.
2245 The source line range is now prefixed with 'at'.
2246 The instruction range is now prefixed with 'inst'.
2247 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2248 "record instruction-history" and "list" commands.
2250 * The ranges given as arguments to the 'record function-call-history' and
2251 'record instruction-history' commands are now inclusive.
2253 * The btrace record target now supports the 'record goto' command.
2254 For locations inside the execution trace, the back trace is computed
2255 based on the information stored in the execution trace.
2257 * The btrace record target supports limited reverse execution and replay.
2258 The target does not record data and therefore does not allow reading
2259 memory or registers.
2261 * The "catch syscall" command now works on s390*-linux* targets.
2263 * The "compare-sections" command is no longer specific to target
2264 remote. It now works with all targets.
2266 * All native targets are now consistently called "native".
2267 Consequently, the "target child", "target GNU", "target djgpp",
2268 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2269 commands have been replaced with "target native". The QNX/NTO port
2270 leaves the "procfs" target in place and adds a "native" target for
2271 consistency with other ports. The impact on users should be minimal
2272 as these commands previously either throwed an error, or were
2273 no-ops. The target's name is visible in the output of the following
2274 commands: "help target", "info target", "info files", "maint print
2277 * The "target native" command now connects to the native target. This
2278 can be used to launch native programs even when "set
2279 auto-connect-native-target" is set to off.
2281 * GDB now supports access to Intel MPX registers on GNU/Linux.
2283 * Support for Intel AVX-512 registers on GNU/Linux.
2284 Support displaying and modifying Intel AVX-512 registers
2285 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2287 * New remote packets
2289 qXfer:btrace:read's annex
2290 The qXfer:btrace:read packet supports a new annex 'delta' to read
2291 branch trace incrementally.
2295 ** Valid Python operations on gdb.Value objects representing
2296 structs/classes invoke the corresponding overloaded operators if
2298 ** New `Xmethods' feature in the Python API. Xmethods are
2299 additional methods or replacements for existing methods of a C++
2300 class. This feature is useful for those cases where a method
2301 defined in C++ source code could be inlined or optimized out by
2302 the compiler, making it unavailable to GDB.
2305 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2307 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2308 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2309 its alias "share", instead.
2311 * The commands "set remotebaud" and "show remotebaud" are no longer
2312 supported. Use "set serial baud" and "show serial baud" (respectively)
2317 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2318 target-async". The latter is left as a deprecated alias of the
2319 former for backward compatibility. If the target supports it,
2320 CLI background execution commands are now always possible by
2321 default, independently of whether the frontend stated a
2322 preference for asynchronous execution with "-gdb-set mi-async".
2323 Previously "-gdb-set target-async off" affected both MI execution
2324 commands and CLI execution commands.
2326 *** Changes in GDB 7.7
2328 * Improved support for process record-replay and reverse debugging on
2329 arm*-linux* targets. Support for thumb32 and syscall instruction
2330 recording has been added.
2332 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2334 * GDB now supports Fission DWP file format version 2.
2335 http://gcc.gnu.org/wiki/DebugFission
2337 * New convenience function "$_isvoid", to check whether an expression
2338 is void. A void expression is an expression where the type of the
2339 result is "void". For example, some convenience variables may be
2340 "void" when evaluated (e.g., "$_exitcode" before the execution of
2341 the program being debugged; or an undefined convenience variable).
2342 Another example, when calling a function whose return type is
2345 * The "maintenance print objfiles" command now takes an optional regexp.
2347 * The "catch syscall" command now works on arm*-linux* targets.
2349 * GDB now consistently shows "<not saved>" when printing values of
2350 registers the debug info indicates have not been saved in the frame
2351 and there's nowhere to retrieve them from
2352 (callee-saved/call-clobbered registers):
2357 (gdb) info registers rax
2360 Before, the former would print "<optimized out>", and the latter
2361 "*value not available*".
2363 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2368 ** Frame filters and frame decorators have been added.
2369 ** Temporary breakpoints are now supported.
2370 ** Line tables representation has been added.
2371 ** New attribute 'parent_type' for gdb.Field objects.
2372 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2373 ** New attribute 'name' for gdb.Type objects.
2377 Nios II ELF nios2*-*-elf
2378 Nios II GNU/Linux nios2*-*-linux
2379 Texas Instruments MSP430 msp430*-*-elf
2381 * Removed native configurations
2383 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2384 been removed. ELF variants of these configurations are kept supported.
2386 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2387 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2388 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2389 i[34567]86-*-openbsd3.[0-3]
2390 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2391 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2392 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2396 Like "catch throw", but catches a re-thrown exception.
2397 maint check-psymtabs
2398 Renamed from old "maint check-symtabs".
2400 Perform consistency checks on symtabs.
2401 maint expand-symtabs
2402 Expand symtabs matching an optional regexp.
2405 Display the details of GDB configure-time options.
2407 maint set|show per-command
2408 maint set|show per-command space
2409 maint set|show per-command time
2410 maint set|show per-command symtab
2411 Enable display of per-command gdb resource usage.
2413 remove-symbol-file FILENAME
2414 remove-symbol-file -a ADDRESS
2415 Remove a symbol file added via add-symbol-file. The file to remove
2416 can be identified by its filename or by an address that lies within
2417 the boundaries of this symbol file in memory.
2420 info exceptions REGEXP
2421 Display the list of Ada exceptions defined in the program being
2422 debugged. If provided, only the exceptions whose names match REGEXP
2427 set debug symfile off|on
2429 Control display of debugging info regarding reading symbol files and
2430 symbol tables within those files
2432 set print raw frame-arguments
2433 show print raw frame-arguments
2434 Set/show whether to print frame arguments in raw mode,
2435 disregarding any defined pretty-printers.
2437 set remote trace-status-packet
2438 show remote trace-status-packet
2439 Set/show the use of remote protocol qTStatus packet.
2443 Control display of debugging messages related to Nios II targets.
2447 Control whether target-assisted range stepping is enabled.
2449 set startup-with-shell
2450 show startup-with-shell
2451 Specifies whether Unix child processes are started via a shell or
2456 Use the target memory cache for accesses to the code segment. This
2457 improves performance of remote debugging (particularly disassembly).
2459 * You can now use a literal value 'unlimited' for options that
2460 interpret 0 or -1 as meaning "unlimited". E.g., "set
2461 trace-buffer-size unlimited" is now an alias for "set
2462 trace-buffer-size -1" and "set height unlimited" is now an alias for
2465 * The "set debug symtab-create" debugging option of GDB has been changed to
2466 accept a verbosity level. 0 means "off", 1 provides basic debugging
2467 output, and values of 2 or greater provides more verbose output.
2469 * New command-line options
2471 Display the details of GDB configure-time options.
2473 * The command 'tsave' can now support new option '-ctf' to save trace
2474 buffer in Common Trace Format.
2476 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2479 * GDB now implements the C++ 'typeid' operator.
2481 * The new convenience variable $_exception holds the exception being
2482 thrown or caught at an exception-related catchpoint.
2484 * The exception-related catchpoints, like "catch throw", now accept a
2485 regular expression which can be used to filter exceptions by type.
2487 * The new convenience variable $_exitsignal is automatically set to
2488 the terminating signal number when the program being debugged dies
2489 due to an uncaught signal.
2493 ** All MI commands now accept an optional "--language" option.
2494 Support for this feature can be verified by using the "-list-features"
2495 command, which should contain "language-option".
2497 ** The new command -info-gdb-mi-command allows the user to determine
2498 whether a GDB/MI command is supported or not.
2500 ** The "^error" result record returned when trying to execute an undefined
2501 GDB/MI command now provides a variable named "code" whose content is the
2502 "undefined-command" error code. Support for this feature can be verified
2503 by using the "-list-features" command, which should contain
2504 "undefined-command-error-code".
2506 ** The -trace-save MI command can optionally save trace buffer in Common
2509 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2511 ** The command -data-list-register-values now accepts an optional
2512 "--skip-unavailable" option. When used, only the available registers
2515 ** The new command -trace-frame-collected dumps collected variables,
2516 computed expressions, tvars, memory and registers in a traceframe.
2518 ** The commands -stack-list-locals, -stack-list-arguments and
2519 -stack-list-variables now accept an option "--skip-unavailable".
2520 When used, only the available locals or arguments are displayed.
2522 ** The -exec-run command now accepts an optional "--start" option.
2523 When used, the command follows the same semantics as the "start"
2524 command, stopping the program's execution at the start of its
2525 main subprogram. Support for this feature can be verified using
2526 the "-list-features" command, which should contain
2527 "exec-run-start-option".
2529 ** The new commands -catch-assert and -catch-exceptions insert
2530 catchpoints stopping the program when Ada exceptions are raised.
2532 ** The new command -info-ada-exceptions provides the equivalent of
2533 the new "info exceptions" command.
2535 * New system-wide configuration scripts
2536 A GDB installation now provides scripts suitable for use as system-wide
2537 configuration scripts for the following systems:
2541 * GDB now supports target-assigned range stepping with remote targets.
2542 This improves the performance of stepping source lines by reducing
2543 the number of control packets from/to GDB. See "New remote packets"
2546 * GDB now understands the element 'tvar' in the XML traceframe info.
2547 It has the id of the collected trace state variables.
2549 * On S/390 targets that provide the transactional-execution feature,
2550 the program interruption transaction diagnostic block (TDB) is now
2551 represented as a number of additional "registers" in GDB.
2553 * New remote packets
2557 The vCont packet supports a new 'r' action, that tells the remote
2558 stub to step through an address range itself, without GDB
2559 involvemement at each single-step.
2561 qXfer:libraries-svr4:read's annex
2562 The previously unused annex of the qXfer:libraries-svr4:read packet
2563 is now used to support passing an argument list. The remote stub
2564 reports support for this argument list to GDB's qSupported query.
2565 The defined arguments are "start" and "prev", used to reduce work
2566 necessary for library list updating, resulting in significant
2569 * New features in the GDB remote stub, GDBserver
2571 ** GDBserver now supports target-assisted range stepping. Currently
2572 enabled on x86/x86_64 GNU/Linux targets.
2574 ** GDBserver now adds element 'tvar' in the XML in the reply to
2575 'qXfer:traceframe-info:read'. It has the id of the collected
2576 trace state variables.
2578 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2581 * New 'z' formatter for printing and examining memory, this displays the
2582 value as hexadecimal zero padded on the left to the size of the type.
2584 * GDB can now use Windows x64 unwinding data.
2586 * The "set remotebaud" command has been replaced by "set serial baud".
2587 Similarly, "show remotebaud" has been replaced by "show serial baud".
2588 The "set remotebaud" and "show remotebaud" commands are still available
2589 to provide backward compatibility with older versions of GDB.
2591 *** Changes in GDB 7.6
2593 * Target record has been renamed to record-full.
2594 Record/replay is now enabled with the "record full" command.
2595 This also affects settings that are associated with full record/replay
2596 that have been moved from "set/show record" to "set/show record full":
2598 set|show record full insn-number-max
2599 set|show record full stop-at-limit
2600 set|show record full memory-query
2602 * A new record target "record-btrace" has been added. The new target
2603 uses hardware support to record the control-flow of a process. It
2604 does not support replaying the execution, but it implements the
2605 below new commands for investigating the recorded execution log.
2606 This new recording method can be enabled using:
2610 The "record-btrace" target is only available on Intel Atom processors
2611 and requires a Linux kernel 2.6.32 or later.
2613 * Two new commands have been added for record/replay to give information
2614 about the recorded execution without having to replay the execution.
2615 The commands are only supported by "record btrace".
2617 record instruction-history prints the execution history at
2618 instruction granularity
2620 record function-call-history prints the execution history at
2621 function granularity
2623 * New native configurations
2625 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2626 FreeBSD/powerpc powerpc*-*-freebsd
2627 x86_64/Cygwin x86_64-*-cygwin*
2628 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2632 ARM AArch64 aarch64*-*-elf
2633 ARM AArch64 GNU/Linux aarch64*-*-linux
2634 Lynx 178 PowerPC powerpc-*-lynx*178
2635 x86_64/Cygwin x86_64-*-cygwin*
2636 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2638 * If the configured location of system.gdbinit file (as given by the
2639 --with-system-gdbinit option at configure time) is in the
2640 data-directory (as specified by --with-gdb-datadir at configure
2641 time) or in one of its subdirectories, then GDB will look for the
2642 system-wide init file in the directory specified by the
2643 --data-directory command-line option.
2645 * New command line options:
2647 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2648 other initialization files, unlike -nx which disables all of them.
2650 * Removed command line options
2652 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2655 * The 'ptype' and 'whatis' commands now accept an argument to control
2658 * 'info proc' now works on some core files.
2662 ** Vectors can be created with gdb.Type.vector.
2664 ** Python's atexit.register now works in GDB.
2666 ** Types can be pretty-printed via a Python API.
2668 ** Python 3 is now supported (in addition to Python 2.4 or later)
2670 ** New class gdb.Architecture exposes GDB's internal representation
2671 of architecture in the Python API.
2673 ** New method Frame.architecture returns the gdb.Architecture object
2674 corresponding to the frame's architecture.
2676 * New Python-based convenience functions:
2678 ** $_memeq(buf1, buf2, length)
2679 ** $_streq(str1, str2)
2681 ** $_regex(str, regex)
2683 * The 'cd' command now defaults to using '~' (the home directory) if not
2686 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2687 default for GCC since November 2000.
2689 * The command 'forward-search' can now be abbreviated as 'fo'.
2691 * The command 'info tracepoints' can now display 'installed on target'
2692 or 'not installed on target' for each non-pending location of tracepoint.
2694 * New configure options
2696 --enable-libmcheck/--disable-libmcheck
2697 By default, development versions are built with -lmcheck on hosts
2698 that support it, in order to help track memory corruption issues.
2699 Release versions, on the other hand, are built without -lmcheck
2700 by default. The --enable-libmcheck/--disable-libmcheck configure
2701 options allow the user to override that default.
2702 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2703 This configure option allows the user to build GDB with
2704 libbabeltrace using which GDB can read Common Trace Format data.
2706 * New commands (for set/show, see "New options" below)
2709 Catch signals. This is similar to "handle", but allows commands and
2710 conditions to be attached.
2713 List the BFDs known to GDB.
2715 python-interactive [command]
2717 Start a Python interactive prompt, or evaluate the optional command
2718 and print the result of expressions.
2721 "py" is a new alias for "python".
2723 enable type-printer [name]...
2724 disable type-printer [name]...
2725 Enable or disable type printers.
2729 ** For the Renesas Super-H architecture, the "regs" command has been removed
2730 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2735 set print type methods (on|off)
2736 show print type methods
2737 Control whether method declarations are displayed by "ptype".
2738 The default is to show them.
2740 set print type typedefs (on|off)
2741 show print type typedefs
2742 Control whether typedef definitions are displayed by "ptype".
2743 The default is to show them.
2745 set filename-display basename|relative|absolute
2746 show filename-display
2747 Control the way in which filenames is displayed.
2748 The default is "relative", which preserves previous behavior.
2750 set trace-buffer-size
2751 show trace-buffer-size
2752 Request target to change the size of trace buffer.
2754 set remote trace-buffer-size-packet auto|on|off
2755 show remote trace-buffer-size-packet
2756 Control the use of the remote protocol `QTBuffer:size' packet.
2760 Control display of debugging messages related to ARM AArch64.
2763 set debug coff-pe-read
2764 show debug coff-pe-read
2765 Control display of debugging messages related to reading of COFF/PE
2770 Control display of debugging messages related to Mach-O symbols
2773 set debug notification
2774 show debug notification
2775 Control display of debugging info for async remote notification.
2779 ** Command parameter changes are now notified using new async record
2780 "=cmd-param-changed".
2781 ** Trace frame changes caused by command "tfind" are now notified using
2782 new async record "=traceframe-changed".
2783 ** The creation, deletion and modification of trace state variables
2784 are now notified using new async records "=tsv-created",
2785 "=tsv-deleted" and "=tsv-modified".
2786 ** The start and stop of process record are now notified using new
2787 async record "=record-started" and "=record-stopped".
2788 ** Memory changes are now notified using new async record
2790 ** The data-disassemble command response will include a "fullname" field
2791 containing the absolute file name when source has been requested.
2792 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2793 command, to allow pattern filling of memory areas.
2794 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2795 library load/unload events.
2796 ** The response to breakpoint commands and breakpoint async records
2797 includes an "installed" field containing a boolean state about each
2798 non-pending tracepoint location is whether installed on target or not.
2799 ** Output of the "-trace-status" command includes a "trace-file" field
2800 containing the name of the trace file being examined. This field is
2801 optional, and only present when examining a trace file.
2802 ** The "fullname" field is now always present along with the "file" field,
2803 even if the file cannot be found by GDB.
2805 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2806 You must have the LZMA library available when configuring GDB for this
2807 feature to be enabled. For more information, see:
2808 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2810 * New remote packets
2813 Set the size of trace buffer. The remote stub reports support for this
2814 packet to gdb's qSupported query.
2817 Enable Branch Trace Store (BTS)-based branch tracing for the current
2818 thread. The remote stub reports support for this packet to gdb's
2822 Disable branch tracing for the current thread. The remote stub reports
2823 support for this packet to gdb's qSupported query.
2826 Read the traced branches for the current thread. The remote stub
2827 reports support for this packet to gdb's qSupported query.
2829 *** Changes in GDB 7.5
2831 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2832 for more x32 ABI info.
2834 * GDB now supports access to MIPS DSP registers on Linux targets.
2836 * GDB now supports debugging microMIPS binaries.
2838 * The "info os" command on GNU/Linux can now display information on
2839 several new classes of objects managed by the operating system:
2840 "info os procgroups" lists process groups
2841 "info os files" lists file descriptors
2842 "info os sockets" lists internet-domain sockets
2843 "info os shm" lists shared-memory regions
2844 "info os semaphores" lists semaphores
2845 "info os msg" lists message queues
2846 "info os modules" lists loaded kernel modules
2848 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2849 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2850 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2851 options and inspect the probe arguments using the new $_probe_arg family
2852 of convenience variables. You can obtain more information about SystemTap
2853 in <http://sourceware.org/systemtap/>.
2855 * GDB now supports reversible debugging on ARM, it allows you to
2856 debug basic ARM and THUMB instructions, and provides
2857 record/replay support.
2859 * The option "symbol-reloading" has been deleted as it is no longer used.
2863 ** GDB commands implemented in Python can now be put in command class
2866 ** The "maint set python print-stack on|off" is now deleted.
2868 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2869 apply "flag enum"-style pretty-printing to any enum.
2871 ** gdb.lookup_symbol can now work when there is no current frame.
2873 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2874 the source at which the symbol was defined.
2876 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2877 method 'value'. The former indicates whether the symbol needs a
2878 frame in order to compute its value, and the latter computes the
2881 ** A new method 'referenced_value' on gdb.Value objects which can
2882 dereference pointer as well as C++ reference values.
2884 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2885 which return the global and static blocks (as gdb.Block objects),
2886 of the underlying symbol table, respectively.
2888 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2889 object associated with a PC value.
2891 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2892 of the address range occupied by code for the current source line.
2894 * Go language support.
2895 GDB now supports debugging programs written in the Go programming
2898 * GDBserver now supports stdio connections.
2899 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2901 * The binary "gdbtui" can no longer be built or installed.
2902 Use "gdb -tui" instead.
2904 * GDB will now print "flag" enums specially. A flag enum is one where
2905 all the enumerator values have no bits in common when pairwise
2906 "and"ed. When printing a value whose type is a flag enum, GDB will
2907 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2908 (gdb) print (enum E) 3
2911 * The filename part of a linespec will now match trailing components
2912 of a source file name. For example, "break gcc/expr.c:1000" will
2913 now set a breakpoint in build/gcc/expr.c, but not
2914 build/libcpp/expr.c.
2916 * The "info proc" and "generate-core-file" commands will now also
2917 work on remote targets connected to GDBserver on Linux.
2919 * The command "info catch" has been removed. It has been disabled
2920 since December 2007.
2922 * The "catch exception" and "catch assert" commands now accept
2923 a condition at the end of the command, much like the "break"
2924 command does. For instance:
2926 (gdb) catch exception Constraint_Error if Barrier = True
2928 Previously, it was possible to add a condition to such catchpoints,
2929 but it had to be done as a second step, after the catchpoint had been
2930 created, using the "condition" command.
2932 * The "info static-tracepoint-marker" command will now also work on
2933 native Linux targets with in-process agent.
2935 * GDB can now set breakpoints on inlined functions.
2937 * The .gdb_index section has been updated to include symbols for
2938 inlined functions. GDB will ignore older .gdb_index sections by
2939 default, which could cause symbol files to be loaded more slowly
2940 until their .gdb_index sections can be recreated. The new command
2941 "set use-deprecated-index-sections on" will cause GDB to use any older
2942 .gdb_index sections it finds. This will restore performance, but the
2943 ability to set breakpoints on inlined functions will be lost in symbol
2944 files with older .gdb_index sections.
2946 The .gdb_index section has also been updated to record more information
2947 about each symbol. This speeds up the "info variables", "info functions"
2948 and "info types" commands when used with programs having the .gdb_index
2949 section, as well as speeding up debugging with shared libraries using
2950 the .gdb_index section.
2952 * Ada support for GDB/MI Variable Objects has been added.
2954 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2959 ** New command -info-os is the MI equivalent of "info os".
2961 ** Output logs ("set logging" and related) now include MI output.
2965 ** "set use-deprecated-index-sections on|off"
2966 "show use-deprecated-index-sections on|off"
2967 Controls the use of deprecated .gdb_index sections.
2969 ** "catch load" and "catch unload" can be used to stop when a shared
2970 library is loaded or unloaded, respectively.
2972 ** "enable count" can be used to auto-disable a breakpoint after
2975 ** "info vtbl" can be used to show the virtual method tables for
2976 C++ and Java objects.
2978 ** "explore" and its sub commands "explore value" and "explore type"
2979 can be used to recursively explore values and types of
2980 expressions. These commands are available only if GDB is
2981 configured with '--with-python'.
2983 ** "info auto-load" shows status of all kinds of auto-loaded files,
2984 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2985 sequences of commands files, "info auto-load python-scripts"
2986 shows status of auto-loading Python script files,
2987 "info auto-load local-gdbinit" shows status of loading init file
2988 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2989 status of inferior specific thread debugging shared library loading.
2991 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2992 and "show auto-load-scripts" commands have been deprecated, use their
2993 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2994 and "show auto-load python-scripts" counterparts instead.
2996 ** "dprintf location,format,args..." creates a dynamic printf, which
2997 is basically a breakpoint that does a printf and immediately
2998 resumes your program's execution, so it is like a printf that you
2999 can insert dynamically at runtime instead of at compiletime.
3001 ** "set print symbol"
3003 Controls whether GDB attempts to display the symbol, if any,
3004 corresponding to addresses it prints. This defaults to "on", but
3005 you can set it to "off" to restore GDB's previous behavior.
3007 * Deprecated commands
3009 ** For the Renesas Super-H architecture, the "regs" command has been
3010 deprecated, and "info all-registers" should be used instead.
3014 Renesas RL78 rl78-*-elf
3015 HP OpenVMS ia64 ia64-hp-openvms*
3017 * GDBserver supports evaluation of breakpoint conditions. When
3018 support is advertised by GDBserver, GDB may be told to send the
3019 breakpoint conditions in bytecode form to GDBserver. GDBserver
3020 will only report the breakpoint trigger to GDB when its condition
3025 set mips compression
3026 show mips compression
3027 Select the compressed ISA encoding used in functions that have no symbol
3028 information available. The encoding can be set to either of:
3031 and is updated automatically from ELF file flags if available.
3033 set breakpoint condition-evaluation
3034 show breakpoint condition-evaluation
3035 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3036 GDBserver ("target"). Default option "auto" chooses the most efficient
3038 This option can improve debugger efficiency depending on the speed of the
3042 Disable auto-loading globally.
3045 Show auto-loading setting of all kinds of auto-loaded files.
3047 set auto-load gdb-scripts on|off
3048 show auto-load gdb-scripts
3049 Control auto-loading of GDB canned sequences of commands files.
3051 set auto-load python-scripts on|off
3052 show auto-load python-scripts
3053 Control auto-loading of Python script files.
3055 set auto-load local-gdbinit on|off
3056 show auto-load local-gdbinit
3057 Control loading of init file (.gdbinit) from current directory.
3059 set auto-load libthread-db on|off
3060 show auto-load libthread-db
3061 Control auto-loading of inferior specific thread debugging shared library.
3063 set auto-load scripts-directory <dir1>[:<dir2>...]
3064 show auto-load scripts-directory
3065 Set a list of directories from which to load auto-loaded scripts.
3066 Automatically loaded Python scripts and GDB scripts are located in one
3067 of the directories listed by this option.
3068 The delimiter (':' above) may differ according to the host platform.
3070 set auto-load safe-path <dir1>[:<dir2>...]
3071 show auto-load safe-path
3072 Set a list of directories from which it is safe to auto-load files.
3073 The delimiter (':' above) may differ according to the host platform.
3075 set debug auto-load on|off
3076 show debug auto-load
3077 Control display of debugging info for auto-loading the files above.
3079 set dprintf-style gdb|call|agent
3081 Control the way in which a dynamic printf is performed; "gdb"
3082 requests a GDB printf command, while "call" causes dprintf to call a
3083 function in the inferior. "agent" requests that the target agent
3084 (such as GDBserver) do the printing.
3086 set dprintf-function <expr>
3087 show dprintf-function
3088 set dprintf-channel <expr>
3089 show dprintf-channel
3090 Set the function and optional first argument to the call when using
3091 the "call" style of dynamic printf.
3093 set disconnected-dprintf on|off
3094 show disconnected-dprintf
3095 Control whether agent-style dynamic printfs continue to be in effect
3096 after GDB disconnects.
3098 * New configure options
3100 --with-auto-load-dir
3101 Configure default value for the 'set auto-load scripts-directory'
3102 setting above. It defaults to '$debugdir:$datadir/auto-load',
3103 $debugdir representing global debugging info directories (available
3104 via 'show debug-file-directory') and $datadir representing GDB's data
3105 directory (available via 'show data-directory').
3107 --with-auto-load-safe-path
3108 Configure default value for the 'set auto-load safe-path' setting
3109 above. It defaults to the --with-auto-load-dir setting.
3111 --without-auto-load-safe-path
3112 Set 'set auto-load safe-path' to '/', effectively disabling this
3115 * New remote packets
3117 z0/z1 conditional breakpoints extension
3119 The z0/z1 breakpoint insertion packets have been extended to carry
3120 a list of conditional expressions over to the remote stub depending on the
3121 condition evaluation mode. The use of this extension can be controlled
3122 via the "set remote conditional-breakpoints-packet" command.
3126 Specify the signals which the remote stub may pass to the debugged
3127 program without GDB involvement.
3129 * New command line options
3131 --init-command=FILE, -ix Like --command, -x but execute it
3132 before loading inferior.
3133 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3134 execute it before loading inferior.
3136 *** Changes in GDB 7.4
3138 * GDB now handles ambiguous linespecs more consistently; the existing
3139 FILE:LINE support has been expanded to other types of linespecs. A
3140 breakpoint will now be set on all matching locations in all
3141 inferiors, and locations will be added or removed according to
3144 * GDB now allows you to skip uninteresting functions and files when
3145 stepping with the "skip function" and "skip file" commands.
3147 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3148 and "show remote hardware-watchpoint-length-limit". These allows to
3149 set or show the maximum length limit (in bytes) of a remote
3150 target hardware watchpoint.
3152 This allows e.g. to use "unlimited" hardware watchpoints with the
3153 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3154 watchpoints are slower than real hardware watchpoints but are
3155 significantly faster than gdb software watchpoints.
3159 ** The register_pretty_printer function in module gdb.printing now takes
3160 an optional `replace' argument. If True, the new printer replaces any
3163 ** The "maint set python print-stack on|off" command has been
3164 deprecated and will be deleted in GDB 7.5.
3165 A new command: "set python print-stack none|full|message" has
3166 replaced it. Additionally, the default for "print-stack" is
3167 now "message", which just prints the error message without
3170 ** A prompt substitution hook (prompt_hook) is now available to the
3173 ** A new Python module, gdb.prompt has been added to the GDB Python
3174 modules library. This module provides functionality for
3175 escape sequences in prompts (used by set/show
3176 extended-prompt). These escape sequences are replaced by their
3177 corresponding value.
3179 ** Python commands and convenience-functions located in
3180 'data-directory'/python/gdb/command and
3181 'data-directory'/python/gdb/function are now automatically loaded
3184 ** Blocks now provide four new attributes. global_block and
3185 static_block will return the global and static blocks
3186 respectively. is_static and is_global are boolean attributes
3187 that indicate if the block is one of those two types.
3189 ** Symbols now provide the "type" attribute, the type of the symbol.
3191 ** The "gdb.breakpoint" function has been deprecated in favor of
3194 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3195 of a function. This class is based on the "finish" command
3196 available in the CLI.
3198 ** Type objects for struct and union types now allow access to
3199 the fields using standard Python dictionary (mapping) methods.
3200 For example, "some_type['myfield']" now works, as does
3201 "some_type.items()".
3203 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3206 ** A new function, "deep_items" has been added to the gdb.types
3207 module in the GDB Python modules library. This function returns
3208 an iterator over the fields of a struct or union type. Unlike
3209 the standard Python "iteritems" method, it will recursively traverse
3210 any anonymous fields.
3214 ** "*stopped" events can report several new "reason"s, such as
3217 ** Breakpoint changes are now notified using new async records, like
3218 "=breakpoint-modified".
3220 ** New command -ada-task-info.
3222 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3223 $sdir specifies the default system locations of shared libraries.
3224 $pdir specifies the directory where the libpthread used by the application
3227 GDB no longer looks in $sdir and $pdir after it has searched the directories
3228 mentioned in libthread-db-search-path. If you want to search those
3229 directories, they must be specified in libthread-db-search-path.
3230 The default value of libthread-db-search-path on GNU/Linux and Solaris
3231 systems is now "$sdir:$pdir".
3233 $pdir is not supported by gdbserver, it is currently ignored.
3234 $sdir is supported by gdbserver.
3236 * New configure option --with-iconv-bin.
3237 When using the internationalization support like the one in the GNU C
3238 library, GDB will invoke the "iconv" program to get a list of supported
3239 character sets. If this program lives in a non-standard location, one can
3240 use this option to specify where to find it.
3242 * When natively debugging programs on PowerPC BookE processors running
3243 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3244 watchpoints, which specify a mask in addition to an address to watch.
3245 The mask specifies that some bits of an address (the bits which are
3246 reset in the mask) should be ignored when matching the address accessed
3247 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3248 section in the user manual for more details.
3250 * The new option --once causes GDBserver to stop listening for connections once
3251 the first connection is made. The listening port used by GDBserver will
3252 become available after that.
3254 * New commands "info macros" and "alias" have been added.
3256 * New function parameters suffix @entry specifies value of function parameter
3257 at the time the function got called. Entry values are available only since
3263 "!" is now an alias of the "shell" command.
3264 Note that no space is needed between "!" and SHELL COMMAND.
3268 watch EXPRESSION mask MASK_VALUE
3269 The watch command now supports the mask argument which allows creation
3270 of masked watchpoints, if the current architecture supports this feature.
3272 info auto-load-scripts [REGEXP]
3273 This command was formerly named "maintenance print section-scripts".
3274 It is now generally useful and is no longer a maintenance-only command.
3276 info macro [-all] [--] MACRO
3277 The info macro command has new options `-all' and `--'. The first for
3278 printing all definitions of a macro. The second for explicitly specifying
3279 the end of arguments and the beginning of the macro name in case the macro
3280 name starts with a hyphen.
3282 collect[/s] EXPRESSIONS
3283 The tracepoint collect command now takes an optional modifier "/s"
3284 that directs it to dereference pointer-to-character types and
3285 collect the bytes of memory up to a zero byte. The behavior is
3286 similar to what you see when you use the regular print command on a
3287 string. An optional integer following the "/s" sets a bound on the
3288 number of bytes that will be collected.
3291 The trace start command now interprets any supplied arguments as a
3292 note to be recorded with the trace run, with an effect similar to
3293 setting the variable trace-notes.
3296 The trace stop command now interprets any arguments as a note to be
3297 mentioned along with the tstatus report that the trace was stopped
3298 with a command. The effect is similar to setting the variable
3301 * Tracepoints can now be enabled and disabled at any time after a trace
3302 experiment has been started using the standard "enable" and "disable"
3303 commands. It is now possible to start a trace experiment with no enabled
3304 tracepoints; GDB will display a warning, but will allow the experiment to
3305 begin, assuming that tracepoints will be enabled as needed while the trace
3308 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3309 locations with 4-byte instructions, when they were previously
3310 limited to locations with instructions of 5 bytes or longer.
3314 set debug dwarf2-read
3315 show debug dwarf2-read
3316 Turns on or off display of debugging messages related to reading
3317 DWARF debug info. The default is off.
3319 set debug symtab-create
3320 show debug symtab-create
3321 Turns on or off display of debugging messages related to symbol table
3322 creation. The default is off.
3325 show extended-prompt
3326 Set the GDB prompt, and allow escape sequences to be inserted to
3327 display miscellaneous information (see 'help set extended-prompt'
3328 for the list of sequences). This prompt (and any information
3329 accessed through the escape sequences) is updated every time the
3330 prompt is displayed.
3332 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3333 show print entry-values
3334 Set printing of frame argument values at function entry. In some cases
3335 GDB can determine the value of function argument which was passed by the
3336 function caller, even if the value was modified inside the called function.
3338 set debug entry-values
3339 show debug entry-values
3340 Control display of debugging info for determining frame argument values at
3341 function entry and virtual tail call frames.
3343 set basenames-may-differ
3344 show basenames-may-differ
3345 Set whether a source file may have multiple base names.
3346 (A "base name" is the name of a file with the directory part removed.
3347 Example: The base name of "/home/user/hello.c" is "hello.c".)
3348 If set, GDB will canonicalize file names (e.g., expand symlinks)
3349 before comparing them. Canonicalization is an expensive operation,
3350 but it allows the same file be known by more than one base name.
3351 If not set (the default), all source files are assumed to have just
3352 one base name, and gdb will do file name comparisons more efficiently.
3358 Set a user name and notes for the current and any future trace runs.
3359 This is useful for long-running and/or disconnected traces, to
3360 inform others (or yourself) as to who is running the trace, supply
3361 contact information, or otherwise explain what is going on.
3363 set trace-stop-notes
3364 show trace-stop-notes
3365 Set a note attached to the trace run, that is displayed when the
3366 trace has been stopped by a tstop command. This is useful for
3367 instance as an explanation, if you are stopping a trace run that was
3368 started by someone else.
3370 * New remote packets
3374 Dynamically enable a tracepoint in a started trace experiment.
3378 Dynamically disable a tracepoint in a started trace experiment.
3382 Set the user and notes of the trace run.
3386 Query the current status of a tracepoint.
3390 Query the minimum length of instruction at which a fast tracepoint may
3393 * Dcache size (number of lines) and line-size are now runtime-configurable
3394 via "set dcache line" and "set dcache line-size" commands.
3398 Texas Instruments TMS320C6x tic6x-*-*
3402 Renesas RL78 rl78-*-elf
3404 *** Changes in GDB 7.3.1
3406 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3408 *** Changes in GDB 7.3
3410 * GDB has a new command: "thread find [REGEXP]".
3411 It finds the thread id whose name, target id, or thread extra info
3412 matches the given regular expression.
3414 * The "catch syscall" command now works on mips*-linux* targets.
3416 * The -data-disassemble MI command now supports modes 2 and 3 for
3417 dumping the instruction opcodes.
3419 * New command line options
3421 -data-directory DIR Specify DIR as the "data-directory".
3422 This is mostly for testing purposes.
3424 * The "maint set python auto-load on|off" command has been renamed to
3425 "set auto-load-scripts on|off".
3427 * GDB has a new command: "set directories".
3428 It is like the "dir" command except that it replaces the
3429 source path list instead of augmenting it.
3431 * GDB now understands thread names.
3433 On GNU/Linux, "info threads" will display the thread name as set by
3434 prctl or pthread_setname_np.
3436 There is also a new command, "thread name", which can be used to
3437 assign a name internally for GDB to display.
3440 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3441 has been integrated into GDB.
3445 ** The function gdb.Write now accepts an optional keyword 'stream'.
3446 This keyword, when provided, will direct the output to either
3447 stdout, stderr, or GDB's logging output.
3449 ** Parameters can now be be sub-classed in Python, and in particular
3450 you may implement the get_set_doc and get_show_doc functions.
3451 This improves how Parameter set/show documentation is processed
3452 and allows for more dynamic content.
3454 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3455 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3456 have an is_valid method.
3458 ** Breakpoints can now be sub-classed in Python, and in particular
3459 you may implement a 'stop' function that is executed each time
3460 the inferior reaches that breakpoint.
3462 ** New function gdb.lookup_global_symbol looks up a global symbol.
3464 ** GDB values in Python are now callable if the value represents a
3465 function. For example, if 'some_value' represents a function that
3466 takes two integer parameters and returns a value, you can call
3467 that function like so:
3469 result = some_value (10,20)
3471 ** Module gdb.types has been added.
3472 It contains a collection of utilities for working with gdb.Types objects:
3473 get_basic_type, has_field, make_enum_dict.
3475 ** Module gdb.printing has been added.
3476 It contains utilities for writing and registering pretty-printers.
3477 New classes: PrettyPrinter, SubPrettyPrinter,
3478 RegexpCollectionPrettyPrinter.
3479 New function: register_pretty_printer.
3481 ** New commands "info pretty-printers", "enable pretty-printer" and
3482 "disable pretty-printer" have been added.
3484 ** gdb.parameter("directories") is now available.
3486 ** New function gdb.newest_frame returns the newest frame in the
3489 ** The gdb.InferiorThread class has a new "name" attribute. This
3490 holds the thread's name.
3492 ** Python Support for Inferior events.
3493 Python scripts can add observers to be notified of events
3494 occurring in the process being debugged.
3495 The following events are currently supported:
3496 - gdb.events.cont Continue event.
3497 - gdb.events.exited Inferior exited event.
3498 - gdb.events.stop Signal received, and Breakpoint hit events.
3502 ** GDB now puts template parameters in scope when debugging in an
3503 instantiation. For example, if you have:
3505 template<int X> int func (void) { return X; }
3507 then if you step into func<5>, "print X" will show "5". This
3508 feature requires proper debuginfo support from the compiler; it
3509 was added to GCC 4.5.
3511 ** The motion commands "next", "finish", "until", and "advance" now
3512 work better when exceptions are thrown. In particular, GDB will
3513 no longer lose control of the inferior; instead, the GDB will
3514 stop the inferior at the point at which the exception is caught.
3515 This functionality requires a change in the exception handling
3516 code that was introduced in GCC 4.5.
3518 * GDB now follows GCC's rules on accessing volatile objects when
3519 reading or writing target state during expression evaluation.
3520 One notable difference to prior behavior is that "print x = 0"
3521 no longer generates a read of x; the value of the assignment is
3522 now always taken directly from the value being assigned.
3524 * GDB now has some support for using labels in the program's source in
3525 linespecs. For instance, you can use "advance label" to continue
3526 execution to a label.
3528 * GDB now has support for reading and writing a new .gdb_index
3529 section. This section holds a fast index of DWARF debugging
3530 information and can be used to greatly speed up GDB startup and
3531 operation. See the documentation for `save gdb-index' for details.
3533 * The "watch" command now accepts an optional "-location" argument.
3534 When used, this causes GDB to watch the memory referred to by the
3535 expression. Such a watchpoint is never deleted due to it going out
3538 * GDB now supports thread debugging of core dumps on GNU/Linux.
3540 GDB now activates thread debugging using the libthread_db library
3541 when debugging GNU/Linux core dumps, similarly to when debugging
3542 live processes. As a result, when debugging a core dump file, GDB
3543 is now able to display pthread_t ids of threads. For example, "info
3544 threads" shows the same output as when debugging the process when it
3545 was live. In earlier releases, you'd see something like this:
3548 * 1 LWP 6780 main () at main.c:10
3550 While now you see this:
3553 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3555 It is also now possible to inspect TLS variables when debugging core
3558 When debugging a core dump generated on a machine other than the one
3559 used to run GDB, you may need to point GDB at the correct
3560 libthread_db library with the "set libthread-db-search-path"
3561 command. See the user manual for more details on this command.
3563 * When natively debugging programs on PowerPC BookE processors running
3564 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3565 which stop execution of the inferior whenever it executes an instruction
3566 at any address within the specified range. See the "PowerPC Embedded"
3567 section in the user manual for more details.
3569 * New features in the GDB remote stub, GDBserver
3571 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3572 and i686 LynxOS (version 5.x).
3574 ** GDBserver is now supported on Blackfin Linux.
3576 * New native configurations
3578 ia64 HP-UX ia64-*-hpux*
3582 Analog Devices, Inc. Blackfin Processor bfin-*
3584 * Ada task switching is now supported on sparc-elf targets when
3585 debugging a program using the Ravenscar Profile. For more information,
3586 see the "Tasking Support when using the Ravenscar Profile" section
3587 in the GDB user manual.
3589 * Guile support was removed.
3591 * New features in the GNU simulator
3593 ** The --map-info flag lists all known core mappings.
3595 ** CFI flashes may be simulated via the "cfi" device.
3597 *** Changes in GDB 7.2
3599 * Shared library support for remote targets by default
3601 When GDB is configured for a generic, non-OS specific target, like
3602 for example, --target=arm-eabi or one of the many *-*-elf targets,
3603 GDB now queries remote stubs for loaded shared libraries using the
3604 `qXfer:libraries:read' packet. Previously, shared library support
3605 was always disabled for such configurations.
3609 ** Argument Dependent Lookup (ADL)
3611 In C++ ADL lookup directs function search to the namespaces of its
3612 arguments even if the namespace has not been imported.
3622 Here the compiler will search for `foo' in the namespace of 'b'
3623 and find A::foo. GDB now supports this. This construct is commonly
3624 used in the Standard Template Library for operators.
3626 ** Improved User Defined Operator Support
3628 In addition to member operators, GDB now supports lookup of operators
3629 defined in a namespace and imported with a `using' directive, operators
3630 defined in the global scope, operators imported implicitly from an
3631 anonymous namespace, and the ADL operators mentioned in the previous
3633 GDB now also supports proper overload resolution for all the previously
3634 mentioned flavors of operators.
3636 ** static const class members
3638 Printing of static const class members that are initialized in the
3639 class definition has been fixed.
3641 * Windows Thread Information Block access.
3643 On Windows targets, GDB now supports displaying the Windows Thread
3644 Information Block (TIB) structure. This structure is visible either
3645 by using the new command `info w32 thread-information-block' or, by
3646 dereferencing the new convenience variable named `$_tlb', a
3647 thread-specific pointer to the TIB. This feature is also supported
3648 when remote debugging using GDBserver.
3650 * Static tracepoints
3652 Static tracepoints are calls in the user program into a tracing
3653 library. One such library is a port of the LTTng kernel tracer to
3654 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3655 When debugging with GDBserver, GDB now supports combining the GDB
3656 tracepoint machinery with such libraries. For example: the user can
3657 use GDB to probe a static tracepoint marker (a call from the user
3658 program into the tracing library) with the new "strace" command (see
3659 "New commands" below). This creates a "static tracepoint" in the
3660 breakpoint list, that can be manipulated with the same feature set
3661 as fast and regular tracepoints. E.g., collect registers, local and
3662 global variables, collect trace state variables, and define
3663 tracepoint conditions. In addition, the user can collect extra
3664 static tracepoint marker specific data, by collecting the new
3665 $_sdata internal variable. When analyzing the trace buffer, you can
3666 inspect $_sdata like any other variable available to GDB. For more
3667 information, see the "Tracepoints" chapter in GDB user manual. New
3668 remote packets have been defined to support static tracepoints, see
3669 the "New remote packets" section below.
3671 * Better reconstruction of tracepoints after disconnected tracing
3673 GDB will attempt to download the original source form of tracepoint
3674 definitions when starting a trace run, and then will upload these
3675 upon reconnection to the target, resulting in a more accurate
3676 reconstruction of the tracepoints that are in use on the target.
3680 You can now exercise direct control over the ways that GDB can
3681 affect your program. For instance, you can disallow the setting of
3682 breakpoints, so that the program can run continuously (assuming
3683 non-stop mode). In addition, the "observer" variable is available
3684 to switch all of the different controls; in observer mode, GDB
3685 cannot affect the target's behavior at all, which is useful for
3686 tasks like diagnosing live systems in the field.
3688 * The new convenience variable $_thread holds the number of the
3691 * New remote packets
3695 Return the address of the Windows Thread Information Block of a given thread.
3699 In response to several of the tracepoint packets, the target may now
3700 also respond with a number of intermediate `qRelocInsn' request
3701 packets before the final result packet, to have GDB handle
3702 relocating an instruction to execute at a different address. This
3703 is particularly useful for stubs that support fast tracepoints. GDB
3704 reports support for this feature in the qSupported packet.
3708 List static tracepoint markers in the target program.
3712 List static tracepoint markers at a given address in the target
3715 qXfer:statictrace:read
3717 Read the static trace data collected (by a `collect $_sdata'
3718 tracepoint action). The remote stub reports support for this packet
3719 to gdb's qSupported query.
3723 Send the current settings of GDB's permission flags.
3727 Send part of the source (textual) form of a tracepoint definition,
3728 which includes location, conditional, and action list.
3730 * The source command now accepts a -s option to force searching for the
3731 script in the source search path even if the script name specifies
3734 * New features in the GDB remote stub, GDBserver
3736 - GDBserver now support tracepoints (including fast tracepoints, and
3737 static tracepoints). The feature is currently supported by the
3738 i386-linux and amd64-linux builds. See the "Tracepoints support
3739 in gdbserver" section in the manual for more information.
3741 GDBserver JIT compiles the tracepoint's conditional agent
3742 expression bytecode into native code whenever possible for low
3743 overhead dynamic tracepoints conditionals. For such tracepoints,
3744 an expression that examines program state is evaluated when the
3745 tracepoint is reached, in order to determine whether to capture
3746 trace data. If the condition is simple and false, processing the
3747 tracepoint finishes very quickly and no data is gathered.
3749 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3750 for static tracepoints support.
3752 - GDBserver now supports x86_64 Windows 64-bit debugging.
3754 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3755 it understands register description.
3757 * The --batch flag now disables pagination and queries.
3759 * X86 general purpose registers
3761 GDB now supports reading/writing byte, word and double-word x86
3762 general purpose registers directly. This means you can use, say,
3763 $ah or $ax to refer, respectively, to the byte register AH and
3764 16-bit word register AX that are actually portions of the 32-bit
3765 register EAX or 64-bit register RAX.
3767 * The `commands' command now accepts a range of breakpoints to modify.
3768 A plain `commands' following a command that creates multiple
3769 breakpoints affects all the breakpoints set by that command. This
3770 applies to breakpoints set by `rbreak', and also applies when a
3771 single `break' command creates multiple breakpoints (e.g.,
3772 breakpoints on overloaded c++ functions).
3774 * The `rbreak' command now accepts a filename specification as part of
3775 its argument, limiting the functions selected by the regex to those
3776 in the specified file.
3778 * Support for remote debugging Windows and SymbianOS shared libraries
3779 from Unix hosts has been improved. Non Windows GDB builds now can
3780 understand target reported file names that follow MS-DOS based file
3781 system semantics, such as file names that include drive letters and
3782 use the backslash character as directory separator. This makes it
3783 possible to transparently use the "set sysroot" and "set
3784 solib-search-path" on Unix hosts to point as host copies of the
3785 target's shared libraries. See the new command "set
3786 target-file-system-kind" described below, and the "Commands to
3787 specify files" section in the user manual for more information.
3791 eval template, expressions...
3792 Convert the values of one or more expressions under the control
3793 of the string template to a command line, and call it.
3795 set target-file-system-kind unix|dos-based|auto
3796 show target-file-system-kind
3797 Set or show the assumed file system kind for target reported file
3800 save breakpoints <filename>
3801 Save all current breakpoint definitions to a file suitable for use
3802 in a later debugging session. To read the saved breakpoint
3803 definitions, use the `source' command.
3805 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3808 info static-tracepoint-markers
3809 Display information about static tracepoint markers in the target.
3811 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3812 Define a static tracepoint by probing a marker at the given
3813 function, line, address, or marker ID.
3817 Enable and disable observer mode.
3819 set may-write-registers on|off
3820 set may-write-memory on|off
3821 set may-insert-breakpoints on|off
3822 set may-insert-tracepoints on|off
3823 set may-insert-fast-tracepoints on|off
3824 set may-interrupt on|off
3825 Set individual permissions for GDB effects on the target. Note that
3826 some of these settings can have undesirable or surprising
3827 consequences, particularly when changed in the middle of a session.
3828 For instance, disabling the writing of memory can prevent
3829 breakpoints from being inserted, cause single-stepping to fail, or
3830 even crash your program, if you disable after breakpoints have been
3831 inserted. However, GDB should not crash.
3833 set record memory-query on|off
3834 show record memory-query
3835 Control whether to stop the inferior if memory changes caused
3836 by an instruction cannot be recorded.
3841 The disassemble command now supports "start,+length" form of two arguments.
3845 ** GDB now provides a new directory location, called the python directory,
3846 where Python scripts written for GDB can be installed. The location
3847 of that directory is <data-directory>/python, where <data-directory>
3848 is the GDB data directory. For more details, see section `Scripting
3849 GDB using Python' in the manual.
3851 ** The GDB Python API now has access to breakpoints, symbols, symbol
3852 tables, program spaces, inferiors, threads and frame's code blocks.
3853 Additionally, GDB Parameters can now be created from the API, and
3854 manipulated via set/show in the CLI.
3856 ** New functions gdb.target_charset, gdb.target_wide_charset,
3857 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3859 ** New exception gdb.GdbError.
3861 ** Pretty-printers are now also looked up in the current program space.
3863 ** Pretty-printers can now be individually enabled and disabled.
3865 ** GDB now looks for names of Python scripts to auto-load in a
3866 special section named `.debug_gdb_scripts', in addition to looking
3867 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3869 * Tracepoint actions were unified with breakpoint commands. In particular,
3870 there are no longer differences in "info break" output for breakpoints and
3871 tracepoints and the "commands" command can be used for both tracepoints and
3872 regular breakpoints.
3876 ARM Symbian arm*-*-symbianelf*
3878 * D language support.
3879 GDB now supports debugging programs written in the D programming
3882 * GDB now supports the extended ptrace interface for PowerPC which is
3883 available since Linux kernel version 2.6.34. This automatically enables
3884 any hardware breakpoints and additional hardware watchpoints available in
3885 the processor. The old ptrace interface exposes just one hardware
3886 watchpoint and no hardware breakpoints.
3888 * GDB is now able to use the Data Value Compare (DVC) register available on
3889 embedded PowerPC processors to implement in hardware simple watchpoint
3890 conditions of the form:
3892 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3894 This works in native GDB running on Linux kernels with the extended ptrace
3895 interface mentioned above.
3897 *** Changes in GDB 7.1
3901 ** Namespace Support
3903 GDB now supports importing of namespaces in C++. This enables the
3904 user to inspect variables from imported namespaces. Support for
3905 namepace aliasing has also been added. So, if a namespace is
3906 aliased in the current scope (e.g. namepace C=A; ) the user can
3907 print variables using the alias (e.g. (gdb) print C::x).
3911 All known bugs relating to the printing of virtual base class were
3912 fixed. It is now possible to call overloaded static methods using a
3917 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3918 and reinterpret_cast<> are now handled by the C++ expression parser.
3922 Xilinx MicroBlaze microblaze-*-*
3927 Xilinx MicroBlaze microblaze
3930 * Multi-program debugging.
3932 GDB now has support for multi-program (a.k.a. multi-executable or
3933 multi-exec) debugging. This allows for debugging multiple inferiors
3934 simultaneously each running a different program under the same GDB
3935 session. See "Debugging Multiple Inferiors and Programs" in the
3936 manual for more information. This implied some user visible changes
3937 in the multi-inferior support. For example, "info inferiors" now
3938 lists inferiors that are not running yet or that have exited
3939 already. See also "New commands" and "New options" below.
3941 * New tracing features
3943 GDB's tracepoint facility now includes several new features:
3945 ** Trace state variables
3947 GDB tracepoints now include support for trace state variables, which
3948 are variables managed by the target agent during a tracing
3949 experiment. They are useful for tracepoints that trigger each
3950 other, so for instance one tracepoint can count hits in a variable,
3951 and then a second tracepoint has a condition that is true when the
3952 count reaches a particular value. Trace state variables share the
3953 $-syntax of GDB convenience variables, and can appear in both
3954 tracepoint actions and condition expressions. Use the "tvariable"
3955 command to create, and "info tvariables" to view; see "Trace State
3956 Variables" in the manual for more detail.
3960 GDB now includes an option for defining fast tracepoints, which
3961 targets may implement more efficiently, such as by installing a jump
3962 into the target agent rather than a trap instruction. The resulting
3963 speedup can be by two orders of magnitude or more, although the
3964 tradeoff is that some program locations on some target architectures
3965 might not allow fast tracepoint installation, for instance if the
3966 instruction to be replaced is shorter than the jump. To request a
3967 fast tracepoint, use the "ftrace" command, with syntax identical to
3968 the regular trace command.
3970 ** Disconnected tracing
3972 It is now possible to detach GDB from the target while it is running
3973 a trace experiment, then reconnect later to see how the experiment
3974 is going. In addition, a new variable disconnected-tracing lets you
3975 tell the target agent whether to continue running a trace if the
3976 connection is lost unexpectedly.
3980 GDB now has the ability to save the trace buffer into a file, and
3981 then use that file as a target, similarly to you can do with
3982 corefiles. You can select trace frames, print data that was
3983 collected in them, and use tstatus to display the state of the
3984 tracing run at the moment that it was saved. To create a trace
3985 file, use "tsave <filename>", and to use it, do "target tfile
3988 ** Circular trace buffer
3990 You can ask the target agent to handle the trace buffer as a
3991 circular buffer, discarding the oldest trace frames to make room for
3992 newer ones, by setting circular-trace-buffer to on. This feature may
3993 not be available for all target agents.
3998 The disassemble command, when invoked with two arguments, now requires
3999 the arguments to be comma-separated.
4002 The info variables command now displays variable definitions. Files
4003 which only declare a variable are not shown.
4006 The source command is now capable of sourcing Python scripts.
4007 This feature is dependent on the debugger being build with Python
4010 Related to this enhancement is also the introduction of a new command
4011 "set script-extension" (see below).
4013 * New commands (for set/show, see "New options" below)
4015 record save [<FILENAME>]
4016 Save a file (in core file format) containing the process record
4017 execution log for replay debugging at a later time.
4019 record restore <FILENAME>
4020 Restore the process record execution log that was saved at an
4021 earlier time, for replay debugging.
4023 add-inferior [-copies <N>] [-exec <FILENAME>]
4026 clone-inferior [-copies <N>] [ID]
4027 Make a new inferior ready to execute the same program another
4028 inferior has loaded.
4033 maint info program-spaces
4034 List the program spaces loaded into GDB.
4036 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4037 show remote interrupt-sequence
4038 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4039 as the sequence to the remote target in order to interrupt the execution.
4040 Ctrl-C is a default. Some system prefers BREAK which is high level of
4041 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4042 Magic SysRq g. It is BREAK signal and character 'g'.
4044 set remote interrupt-on-connect [on | off]
4045 show remote interrupt-on-connect
4046 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4047 remote target when gdb connects to it. This is needed when you debug
4050 set remotebreak [on | off]
4052 Deprecated. Use "set/show remote interrupt-sequence" instead.
4054 tvariable $NAME [ = EXP ]
4055 Create or modify a trace state variable.
4058 List trace state variables and their values.
4060 delete tvariable $NAME ...
4061 Delete one or more trace state variables.
4064 Evaluate the given expressions without collecting anything into the
4065 trace buffer. (Valid in tracepoint actions only.)
4067 ftrace FN / FILE:LINE / *ADDR
4068 Define a fast tracepoint at the given function, line, or address.
4070 * New expression syntax
4072 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4073 GDB now parses 0b101010 identically with 42.
4077 set follow-exec-mode new|same
4078 show follow-exec-mode
4079 Control whether GDB reuses the same inferior across an exec call or
4080 creates a new one. This is useful to be able to restart the old
4081 executable after the inferior having done an exec call.
4083 set default-collect EXPR, ...
4084 show default-collect
4085 Define a list of expressions to be collected at each tracepoint.
4086 This is a useful way to ensure essential items are not overlooked,
4087 such as registers or a critical global variable.
4089 set disconnected-tracing
4090 show disconnected-tracing
4091 If set to 1, the target is instructed to continue tracing if it
4092 loses its connection to GDB. If 0, the target is to stop tracing
4095 set circular-trace-buffer
4096 show circular-trace-buffer
4097 If set to on, the target is instructed to use a circular trace buffer
4098 and discard the oldest trace frames instead of stopping the trace due
4099 to a full trace buffer. If set to off, the trace stops when the buffer
4100 fills up. Some targets may not support this.
4102 set script-extension off|soft|strict
4103 show script-extension
4104 If set to "off", the debugger does not perform any script language
4105 recognition, and all sourced files are assumed to be GDB scripts.
4106 If set to "soft" (the default), files are sourced according to
4107 filename extension, falling back to GDB scripts if the first
4109 If set to "strict", files are sourced according to filename extension.
4111 set ada trust-PAD-over-XVS on|off
4112 show ada trust-PAD-over-XVS
4113 If off, activate a workaround against a bug in the debugging information
4114 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4115 the GCC sources for more information about the GNAT encoding and
4116 PAD types in particular). It is always safe to set this option to
4117 off, but this introduces a slight performance penalty. The default
4120 * Python API Improvements
4122 ** GDB provides the new class gdb.LazyString. This is useful in
4123 some pretty-printing cases. The new method gdb.Value.lazy_string
4124 provides a simple way to create objects of this type.
4126 ** The fields returned by gdb.Type.fields now have an
4127 `is_base_class' attribute.
4129 ** The new method gdb.Type.range returns the range of an array type.
4131 ** The new method gdb.parse_and_eval can be used to parse and
4132 evaluate an expression.
4134 * New remote packets
4137 Define a trace state variable.
4140 Get the current value of a trace state variable.
4143 Set desired tracing behavior upon disconnection.
4146 Set the trace buffer to be linear or circular.
4149 Get data about the tracepoints currently in use.
4153 Process record now works correctly with hardware watchpoints.
4155 Multiple bug fixes have been made to the mips-irix port, making it
4156 much more reliable. In particular:
4157 - Debugging threaded applications is now possible again. Previously,
4158 GDB would hang while starting the program, or while waiting for
4159 the program to stop at a breakpoint.
4160 - Attaching to a running process no longer hangs.
4161 - An error occurring while loading a core file has been fixed.
4162 - Changing the value of the PC register now works again. This fixes
4163 problems observed when using the "jump" command, or when calling
4164 a function from GDB, or even when assigning a new value to $pc.
4165 - With the "finish" and "return" commands, the return value for functions
4166 returning a small array is now correctly printed.
4167 - It is now possible to break on shared library code which gets executed
4168 during a shared library init phase (code executed while executing
4169 their .init section). Previously, the breakpoint would have no effect.
4170 - GDB is now able to backtrace through the signal handler for
4171 non-threaded programs.
4173 PIE (Position Independent Executable) programs debugging is now supported.
4174 This includes debugging execution of PIC (Position Independent Code) shared
4175 libraries although for that, it should be possible to run such libraries as an
4178 *** Changes in GDB 7.0
4180 * GDB now has an interface for JIT compilation. Applications that
4181 dynamically generate code can create symbol files in memory and register
4182 them with GDB. For users, the feature should work transparently, and
4183 for JIT developers, the interface is documented in the GDB manual in the
4184 "JIT Compilation Interface" chapter.
4186 * Tracepoints may now be conditional. The syntax is as for
4187 breakpoints; either an "if" clause appended to the "trace" command,
4188 or the "condition" command is available. GDB sends the condition to
4189 the target for evaluation using the same bytecode format as is used
4190 for tracepoint actions.
4192 * The disassemble command now supports: an optional /r modifier, print the
4193 raw instructions in hex as well as in symbolic form, and an optional /m
4194 modifier to print mixed source+assembly.
4196 * Process record and replay
4198 In a architecture environment that supports ``process record and
4199 replay'', ``process record and replay'' target can record a log of
4200 the process execution, and replay it with both forward and reverse
4203 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4204 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4205 set execution-direction {forward|reverse}, for targets that support
4208 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4209 feature is available with a native GDB running on kernel version
4212 * GDB now has support for multi-byte and wide character sets on the
4213 target. Strings whose character type is wchar_t, char16_t, or
4214 char32_t are now correctly printed. GDB supports wide- and unicode-
4215 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4216 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4217 `printf'. This feature requires iconv to work properly; if your
4218 system does not have a working iconv, GDB can use GNU libiconv. See
4219 the installation instructions for more information.
4221 * GDB now supports automatic retrieval of shared library files from
4222 remote targets. To use this feature, specify a system root that begins
4223 with the `remote:' prefix, either via the `set sysroot' command or via
4224 the `--with-sysroot' configure-time option.
4226 * "info sharedlibrary" now takes an optional regex of libraries to show,
4227 and it now reports if a shared library has no debugging information.
4229 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4230 now complete on file names.
4232 * When completing in expressions, gdb will attempt to limit
4233 completions to allowable structure or union fields, where appropriate.
4234 For instance, consider:
4236 # struct example { int f1; double f2; };
4237 # struct example variable;
4240 If the user types TAB at the end of this command line, the available
4241 completions will be "f1" and "f2".
4243 * Inlined functions are now supported. They show up in backtraces, and
4244 the "step", "next", and "finish" commands handle them automatically.
4246 * GDB now supports the token-splicing (##) and stringification (#)
4247 operators when expanding macros. It also supports variable-arity
4250 * GDB now supports inspecting extra signal information, exported by
4251 the new $_siginfo convenience variable. The feature is currently
4252 implemented on linux ARM, i386 and amd64.
4254 * GDB can now display the VFP floating point registers and NEON vector
4255 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4256 can provide these registers (requires Linux 2.6.30 or later). Remote
4257 and simulator targets may also provide them.
4259 * New remote packets
4262 Search memory for a sequence of bytes.
4265 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4266 operation over reliable transport links. Use of this packet is
4267 controlled by the `set remote noack-packet' command.
4270 Kill the process with the specified process ID. Use this in preference
4271 to `k' when multiprocess protocol extensions are supported.
4274 Obtains additional operating system information
4278 Read or write additional signal information.
4280 * Removed remote protocol undocumented extension
4282 An undocumented extension to the remote protocol's `S' stop reply
4283 packet that permitted the stub to pass a process id was removed.
4284 Remote servers should use the `T' stop reply packet instead.
4286 * GDB now supports multiple function calling conventions according to the
4287 DWARF-2 DW_AT_calling_convention function attribute.
4289 * The SH target utilizes the aforementioned change to distinguish between gcc
4290 and Renesas calling convention. It also adds the new CLI commands
4291 `set/show sh calling-convention'.
4293 * GDB can now read compressed debug sections, as produced by GNU gold
4294 with the --compress-debug-sections=zlib flag.
4296 * 64-bit core files are now supported on AIX.
4298 * Thread switching is now supported on Tru64.
4300 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4301 which will be allocated using malloc later in program execution.
4303 * The qXfer:libraries:read remote protocol packet now allows passing a
4304 list of section offsets.
4306 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4307 conditions handling signals delivered during attach or thread creation
4308 have also been fixed.
4310 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4311 From the user's standpoint, all unqualified instances of True and False
4312 are treated as the standard definitions, regardless of context.
4314 * GDB now parses C++ symbol and type names more flexibly. For
4317 template<typename T> class C { };
4320 GDB will now correctly handle all of:
4322 ptype C<char const *>
4323 ptype C<char const*>
4324 ptype C<const char *>
4325 ptype C<const char*>
4327 * New features in the GDB remote stub, gdbserver
4329 - The "--wrapper" command-line argument tells gdbserver to use a
4330 wrapper program to launch programs for debugging.
4332 - On PowerPC and S/390 targets, it is now possible to use a single
4333 gdbserver executable to debug both 32-bit and 64-bit programs.
4334 (This requires gdbserver itself to be built as a 64-bit executable.)
4336 - gdbserver uses the new noack protocol mode for TCP connections to
4337 reduce communications latency, if also supported and enabled in GDB.
4339 - Support for the sparc64-linux-gnu target is now included in
4342 - The amd64-linux build of gdbserver now supports debugging both
4343 32-bit and 64-bit programs.
4345 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4346 now support hardware watchpoints, and will use them automatically
4351 GDB now has support for scripting using Python. Whether this is
4352 available is determined at configure time.
4354 New GDB commands can now be written in Python.
4356 * Ada tasking support
4358 Ada tasks can now be inspected in GDB. The following commands have
4362 Print the list of Ada tasks.
4364 Print detailed information about task number N.
4366 Print the task number of the current task.
4368 Switch the context of debugging to task number N.
4370 * Support for user-defined prefixed commands. The "define" command can
4371 add new commands to existing prefixes, e.g. "target".
4373 * Multi-inferior, multi-process debugging.
4375 GDB now has generalized support for multi-inferior debugging. See
4376 "Debugging Multiple Inferiors" in the manual for more information.
4377 Although availability still depends on target support, the command
4378 set is more uniform now. The GNU/Linux specific multi-forks support
4379 has been migrated to this new framework. This implied some user
4380 visible changes; see "New commands" and also "Removed commands"
4383 * Target descriptions can now describe the target OS ABI. See the
4384 "Target Description Format" section in the user manual for more
4387 * Target descriptions can now describe "compatible" architectures
4388 to indicate that the target can execute applications for a different
4389 architecture in addition to those for the main target architecture.
4390 See the "Target Description Format" section in the user manual for
4393 * Multi-architecture debugging.
4395 GDB now includes general supports for debugging applications on
4396 hybrid systems that use more than one single processor architecture
4397 at the same time. Each such hybrid architecture still requires
4398 specific support to be added. The only hybrid architecture supported
4399 in this version of GDB is the Cell Broadband Engine.
4401 * GDB now supports integrated debugging of Cell/B.E. applications that
4402 use both the PPU and SPU architectures. To enable support for hybrid
4403 Cell/B.E. debugging, you need to configure GDB to support both the
4404 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4405 --enable-targets configure option.
4407 * Non-stop mode debugging.
4409 For some targets, GDB now supports an optional mode of operation in
4410 which you can examine stopped threads while other threads continue
4411 to execute freely. This is referred to as non-stop mode, with the
4412 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4413 section in the user manual for more information.
4415 To be able to support remote non-stop debugging, a remote stub needs
4416 to implement the non-stop mode remote protocol extensions, as
4417 described in the "Remote Non-Stop" section of the user manual. The
4418 GDB remote stub, gdbserver, has been adjusted to support these
4419 extensions on linux targets.
4421 * New commands (for set/show, see "New options" below)
4423 catch syscall [NAME(S) | NUMBER(S)]
4424 Catch system calls. Arguments, which should be names of system
4425 calls or their numbers, mean catch only those syscalls. Without
4426 arguments, every syscall will be caught. When the inferior issues
4427 any of the specified syscalls, GDB will stop and announce the system
4428 call, both when it is called and when its call returns. This
4429 feature is currently available with a native GDB running on the
4430 Linux Kernel, under the following architectures: x86, x86_64,
4431 PowerPC and PowerPC64.
4433 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4435 Search memory for a sequence of bytes.
4437 maint set python print-stack
4438 maint show python print-stack
4439 Show a stack trace when an error is encountered in a Python script.
4442 Invoke CODE by passing it to the Python interpreter.
4447 These allow macros to be defined, undefined, and listed
4451 Show operating system information about processes.
4454 List the inferiors currently under GDB's control.
4457 Switch focus to inferior number NUM.
4460 Detach from inferior number NUM.
4463 Kill inferior number NUM.
4467 set spu stop-on-load
4468 show spu stop-on-load
4469 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4471 set spu auto-flush-cache
4472 show spu auto-flush-cache
4473 Control whether to automatically flush the software-managed cache
4474 during Cell/B.E. debugging.
4476 set sh calling-convention
4477 show sh calling-convention
4478 Control the calling convention used when calling SH target functions.
4481 show debug timestamp
4482 Control display of timestamps with GDB debugging output.
4484 set disassemble-next-line
4485 show disassemble-next-line
4486 Control display of disassembled source lines or instructions when
4489 set remote noack-packet
4490 show remote noack-packet
4491 Set/show the use of remote protocol QStartNoAckMode packet. See above
4492 under "New remote packets."
4494 set remote query-attached-packet
4495 show remote query-attached-packet
4496 Control use of remote protocol `qAttached' (query-attached) packet.
4498 set remote read-siginfo-object
4499 show remote read-siginfo-object
4500 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4503 set remote write-siginfo-object
4504 show remote write-siginfo-object
4505 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4508 set remote reverse-continue
4509 show remote reverse-continue
4510 Control use of remote protocol 'bc' (reverse-continue) packet.
4512 set remote reverse-step
4513 show remote reverse-step
4514 Control use of remote protocol 'bs' (reverse-step) packet.
4516 set displaced-stepping
4517 show displaced-stepping
4518 Control displaced stepping mode. Displaced stepping is a way to
4519 single-step over breakpoints without removing them from the debuggee.
4520 Also known as "out-of-line single-stepping".
4523 show debug displaced
4524 Control display of debugging info for displaced stepping.
4526 maint set internal-error
4527 maint show internal-error
4528 Control what GDB does when an internal error is detected.
4530 maint set internal-warning
4531 maint show internal-warning
4532 Control what GDB does when an internal warning is detected.
4537 Use a wrapper program to launch programs for debugging.
4539 set multiple-symbols (all|ask|cancel)
4540 show multiple-symbols
4541 The value of this variable can be changed to adjust the debugger behavior
4542 when an expression or a breakpoint location contains an ambiguous symbol
4543 name (an overloaded function name, for instance).
4545 set breakpoint always-inserted
4546 show breakpoint always-inserted
4547 Keep breakpoints always inserted in the target, as opposed to inserting
4548 them when resuming the target, and removing them when the target stops.
4549 This option can improve debugger performance on slow remote targets.
4551 set arm fallback-mode (arm|thumb|auto)
4552 show arm fallback-mode
4553 set arm force-mode (arm|thumb|auto)
4555 These commands control how ARM GDB determines whether instructions
4556 are ARM or Thumb. The default for both settings is auto, which uses
4557 the current CPSR value for instructions without symbols; previous
4558 versions of GDB behaved as if "set arm fallback-mode arm".
4560 set disable-randomization
4561 show disable-randomization
4562 Standalone programs run with the virtual address space randomization enabled
4563 by default on some platforms. This option keeps the addresses stable across
4564 multiple debugging sessions.
4568 Control whether other threads are stopped or not when some thread hits
4573 Requests that asynchronous execution is enabled in the target, if available.
4574 In this case, it's possible to resume target in the background, and interact
4575 with GDB while the target is running. "show target-async" displays the
4576 current state of asynchronous execution of the target.
4578 set target-wide-charset
4579 show target-wide-charset
4580 The target-wide-charset is the name of the character set that GDB
4581 uses when printing characters whose type is wchar_t.
4583 set tcp auto-retry (on|off)
4585 set tcp connect-timeout
4586 show tcp connect-timeout
4587 These commands allow GDB to retry failed TCP connections to a remote stub
4588 with a specified timeout period; this is useful if the stub is launched
4589 in parallel with GDB but may not be ready to accept connections immediately.
4591 set libthread-db-search-path
4592 show libthread-db-search-path
4593 Control list of directories which GDB will search for appropriate
4596 set schedule-multiple (on|off)
4597 show schedule-multiple
4598 Allow GDB to resume all threads of all processes or only threads of
4599 the current process.
4603 Use more aggressive caching for accesses to the stack. This improves
4604 performance of remote debugging (particularly backtraces) without
4605 affecting correctness.
4607 set interactive-mode (on|off|auto)
4608 show interactive-mode
4609 Control whether GDB runs in interactive mode (on) or not (off).
4610 When in interactive mode, GDB waits for the user to answer all
4611 queries. Otherwise, GDB does not wait and assumes the default
4612 answer. When set to auto (the default), GDB determines which
4613 mode to use based on the stdin settings.
4618 For program forks, this is replaced by the new more generic `info
4619 inferiors' command. To list checkpoints, you can still use the
4620 `info checkpoints' command, which was an alias for the `info forks'
4624 Replaced by the new `inferior' command. To switch between
4625 checkpoints, you can still use the `restart' command, which was an
4626 alias for the `fork' command.
4629 This is removed, since some targets don't have a notion of
4630 processes. To switch between processes, you can still use the
4631 `inferior' command using GDB's own inferior number.
4634 For program forks, this is replaced by the new more generic `kill
4635 inferior' command. To delete a checkpoint, you can still use the
4636 `delete checkpoint' command, which was an alias for the `delete
4640 For program forks, this is replaced by the new more generic `detach
4641 inferior' command. To detach a checkpoint, you can still use the
4642 `detach checkpoint' command, which was an alias for the `detach
4645 * New native configurations
4647 x86/x86_64 Darwin i[34567]86-*-darwin*
4649 x86_64 MinGW x86_64-*-mingw*
4653 Lattice Mico32 lm32-*
4654 x86 DICOS i[34567]86-*-dicos*
4655 x86_64 DICOS x86_64-*-dicos*
4658 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4659 (mingw32ce) debugging.
4665 These commands were actually not implemented on any target.
4667 *** Changes in GDB 6.8
4669 * New native configurations
4671 NetBSD/hppa hppa*-*netbsd*
4672 Xtensa GNU/Linux xtensa*-*-linux*
4676 NetBSD/hppa hppa*-*-netbsd*
4677 Xtensa GNU/Linux xtensa*-*-linux*
4679 * Change in command line behavior -- corefiles vs. process ids.
4681 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4682 attaching to process NUMBER fails, GDB no longer attempts to open a
4683 core file named NUMBER. Attaching to a program using the -c option
4684 is no longer supported. Instead, use the '-p' or '--pid' options.
4686 * GDB can now be built as a native debugger for debugging Windows x86
4687 (mingw32) Portable Executable (PE) programs.
4689 * Pending breakpoints no longer change their number when their address
4692 * GDB now supports breakpoints with multiple locations,
4693 including breakpoints on C++ constructors, inside C++ templates,
4694 and in inlined functions.
4696 * GDB's ability to debug optimized code has been improved. GDB more
4697 accurately identifies function bodies and lexical blocks that occupy
4698 more than one contiguous range of addresses.
4700 * Target descriptions can now describe registers for PowerPC.
4702 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4703 registers on PowerPC targets.
4705 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4706 targets even when the libthread_db library is not available.
4708 * The GDB remote stub, gdbserver, now supports the new file transfer
4709 commands (remote put, remote get, and remote delete).
4711 * The GDB remote stub, gdbserver, now supports run and attach in
4712 extended-remote mode.
4714 * hppa*64*-*-hpux11* target broken
4715 The debugger is unable to start a program and fails with the following
4716 error: "Error trying to get information about dynamic linker".
4717 The gdb-6.7 release is also affected.
4719 * GDB now supports the --enable-targets= configure option to allow
4720 building a single GDB executable that supports multiple remote
4721 target architectures.
4723 * GDB now supports debugging C and C++ programs which use the
4724 Decimal Floating Point extension. In addition, the PowerPC target
4725 now has a set of pseudo-registers to inspect decimal float values
4726 stored in two consecutive float registers.
4728 * The -break-insert MI command can optionally create pending
4731 * Improved support for debugging Ada
4732 Many improvements to the Ada language support have been made. These
4734 - Better support for Ada2005 interface types
4735 - Improved handling of arrays and slices in general
4736 - Better support for Taft-amendment types
4737 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4739 - Improved command completion in Ada
4742 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4747 set print frame-arguments (all|scalars|none)
4748 show print frame-arguments
4749 The value of this variable can be changed to control which argument
4750 values should be printed by the debugger when displaying a frame.
4755 Transfer files to and from a remote target, and delete remote files.
4762 Transfer files to and from a remote target, and delete remote files.
4764 * New remote packets
4771 Open, close, read, write, and delete files on the remote system.
4774 Attach to an existing process on the remote system, in extended-remote
4778 Run a new process on the remote system, in extended-remote mode.
4780 *** Changes in GDB 6.7
4782 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4783 bfd, libiberty and opcodes, as revealed by static analysis donated by
4784 Coverity, Inc. (http://scan.coverity.com).
4786 * When looking up multiply-defined global symbols, GDB will now prefer the
4787 symbol definition in the current shared library if it was built using the
4788 -Bsymbolic linker option.
4790 * When the Text User Interface (TUI) is not configured, GDB will now
4791 recognize the -tui command-line option and print a message that the TUI
4794 * The GDB remote stub, gdbserver, now has lower overhead for high
4795 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4797 * GDB for MIPS targets now autodetects whether a remote target provides
4798 32-bit or 64-bit register values.
4800 * Support for C++ member pointers has been improved.
4802 * GDB now understands XML target descriptions, which specify the
4803 target's overall architecture. GDB can read a description from
4804 a local file or over the remote serial protocol.
4806 * Vectors of single-byte data use a new integer type which is not
4807 automatically displayed as character or string data.
4809 * The /s format now works with the print command. It displays
4810 arrays of single-byte integers and pointers to single-byte integers
4813 * Target descriptions can now describe target-specific registers,
4814 for architectures which have implemented the support (currently
4815 only ARM, M68K, and MIPS).
4817 * GDB and the GDB remote stub, gdbserver, now support the XScale
4820 * The GDB remote stub, gdbserver, has been updated to support
4821 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4822 has been rewritten to use the standard GDB remote protocol.
4824 * GDB can now step into C++ functions which are called through thunks.
4826 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4828 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4829 layout. It also supports a TextSeg= and DataSeg= response when only
4830 segment base addresses (rather than offsets) are available.
4832 * The /i format now outputs any trailing branch delay slot instructions
4833 immediately following the last instruction within the count specified.
4835 * The GDB remote protocol "T" stop reply packet now supports a
4836 "library" response. Combined with the new "qXfer:libraries:read"
4837 packet, this response allows GDB to debug shared libraries on targets
4838 where the operating system manages the list of loaded libraries (e.g.
4839 Windows and SymbianOS).
4841 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4842 (DLLs) on Windows and Windows CE targets.
4844 * GDB now supports a faster verification that a .debug file matches its binary
4845 according to its build-id signature, if the signature is present.
4851 Enable or disable hardware flow control (RTS/CTS) on the serial port
4852 when debugging using remote targets.
4854 set mem inaccessible-by-default
4855 show mem inaccessible-by-default
4856 If the target supplies a memory map, for instance via the remote
4857 protocol's "qXfer:memory-map:read" packet, setting this variable
4858 prevents GDB from accessing memory outside the memory map. This
4859 is useful for targets with memory mapped registers or which react
4860 badly to accesses of unmapped address space.
4862 set breakpoint auto-hw
4863 show breakpoint auto-hw
4864 If the target supplies a memory map, for instance via the remote
4865 protocol's "qXfer:memory-map:read" packet, setting this variable
4866 lets GDB use hardware breakpoints automatically for memory regions
4867 where it can not use software breakpoints. This covers both the
4868 "break" command and internal breakpoints used for other commands
4869 including "next" and "finish".
4872 catch exception unhandled
4873 Stop the program execution when Ada exceptions are raised.
4876 Stop the program execution when an Ada assertion failed.
4880 Set an alternate system root for target files. This is a more
4881 general version of "set solib-absolute-prefix", which is now
4882 an alias to "set sysroot".
4885 Provide extended SPU facility status information. This set of
4886 commands is available only when debugging the Cell/B.E. SPU
4889 * New native configurations
4891 OpenBSD/sh sh*-*openbsd*
4894 unset tdesc filename
4896 Use the specified local file as an XML target description, and do
4897 not query the target for its built-in description.
4901 OpenBSD/sh sh*-*-openbsd*
4902 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4903 Toshiba Media Processor mep-elf
4905 * New remote packets
4908 Ignore the specified signals; pass them directly to the debugged program
4909 without stopping other threads or reporting them to GDB.
4911 qXfer:features:read:
4912 Read an XML target description from the target, which describes its
4917 Read or write contents of an spufs file on the target system. These
4918 packets are available only on the Cell/B.E. SPU architecture.
4920 qXfer:libraries:read:
4921 Report the loaded shared libraries. Combined with new "T" packet
4922 response, this packet allows GDB to debug shared libraries on
4923 targets where the operating system manages the list of loaded
4924 libraries (e.g. Windows and SymbianOS).
4928 Support for these obsolete configurations has been removed.
4936 i[34567]86-*-lynxos*
4937 i[34567]86-*-netware*
4938 i[34567]86-*-sco3.2v5*
4939 i[34567]86-*-sco3.2v4*
4941 i[34567]86-*-sysv4.2*
4944 i[34567]86-*-unixware2*
4945 i[34567]86-*-unixware*
4954 * Other removed features
4961 Various m68k-only ROM monitors.
4968 Various Renesas ROM monitors and debugging interfaces for SH and
4973 Support for a Macraigor serial interface to on-chip debugging.
4974 GDB does not directly support the newer parallel or USB
4979 A debug information format. The predecessor to DWARF 2 and
4980 DWARF 3, which are still supported.
4982 Support for the HP aCC compiler on HP-UX/PA-RISC
4984 SOM-encapsulated symbolic debugging information, automatic
4985 invocation of pxdb, and the aCC custom C++ ABI. This does not
4986 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4987 with aCC can still be debugged on an assembly level.
4989 MIPS ".pdr" sections
4991 A MIPS-specific format used to describe stack frame layout
4992 in debugging information.
4996 GDB could work with an older version of Guile to debug
4997 the interpreter and Scheme programs running in it.
4999 set mips stack-arg-size
5000 set mips saved-gpreg-size
5002 Use "set mips abi" to control parameter passing for MIPS.
5004 *** Changes in GDB 6.6
5009 Cell Broadband Engine SPU spu-elf
5011 * GDB can now be configured as a cross-debugger targeting native Windows
5012 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5013 running on a Windows system over TCP/IP to debug Windows programs.
5015 * The GDB remote stub, gdbserver, has been updated to support Windows and
5016 Cygwin debugging. Both single-threaded and multi-threaded programs are
5019 * The "set trust-readonly-sections" command works again. This command was
5020 broken in GDB 6.3, 6.4, and 6.5.
5022 * The "load" command now supports writing to flash memory, if the remote
5023 stub provides the required support.
5025 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5026 longer requires symbolic debug information (e.g. DWARF-2).
5031 unset substitute-path
5032 show substitute-path
5033 Manage a list of substitution rules that GDB uses to rewrite the name
5034 of the directories where the sources are located. This can be useful
5035 for instance when the sources were moved to a different location
5036 between compilation and debugging.
5040 Print each CLI command as it is executed. Each command is prefixed with
5041 a number of `+' symbols representing the nesting depth.
5042 The source command now has a `-v' option to enable the same feature.
5046 The ARM Demon monitor support (RDP protocol, "target rdp").
5048 Kernel Object Display, an embedded debugging feature which only worked with
5049 an obsolete version of Cisco IOS.
5051 The 'set download-write-size' and 'show download-write-size' commands.
5053 * New remote packets
5056 Tell a stub about GDB client features, and request remote target features.
5057 The first feature implemented is PacketSize, which allows the target to
5058 specify the size of packets it can handle - to minimize the number of
5059 packets required and improve performance when connected to a remote
5063 Fetch an OS auxilliary vector from the remote stub. This packet is a
5064 more efficient replacement for qPart:auxv:read.
5066 qXfer:memory-map:read:
5067 Fetch a memory map from the remote stub, including information about
5068 RAM, ROM, and flash memory devices.
5073 Erase and program a flash memory device.
5075 * Removed remote packets
5078 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5079 used it, and only gdbserver implemented it.
5081 *** Changes in GDB 6.5
5085 Renesas M32C/M16C m32c-elf
5087 Morpho Technologies ms1 ms1-elf
5091 init-if-undefined Initialize a convenience variable, but
5092 only if it doesn't already have a value.
5094 The following commands are presently only implemented for native GNU/Linux:
5096 checkpoint Save a snapshot of the program state.
5098 restart <n> Return the program state to a
5099 previously saved state.
5101 info checkpoints List currently saved checkpoints.
5103 delete-checkpoint <n> Delete a previously saved checkpoint.
5105 set|show detach-on-fork Tell gdb whether to detach from a newly
5106 forked process, or to keep debugging it.
5108 info forks List forks of the user program that
5109 are available to be debugged.
5111 fork <n> Switch to debugging one of several
5112 forks of the user program that are
5113 available to be debugged.
5115 delete-fork <n> Delete a fork from the list of forks
5116 that are available to be debugged (and
5117 kill the forked process).
5119 detach-fork <n> Delete a fork from the list of forks
5120 that are available to be debugged (and
5121 allow the process to continue).
5125 Morpho Technologies ms2 ms1-elf
5127 * Improved Windows host support
5129 GDB now builds as a cross debugger hosted on i686-mingw32, including
5130 native console support, and remote communications using either
5131 network sockets or serial ports.
5133 * Improved Modula-2 language support
5135 GDB can now print most types in the Modula-2 syntax. This includes:
5136 basic types, set types, record types, enumerated types, range types,
5137 pointer types and ARRAY types. Procedure var parameters are correctly
5138 printed and hexadecimal addresses and character constants are also
5139 written in the Modula-2 syntax. Best results can be obtained by using
5140 GNU Modula-2 together with the -gdwarf-2 command line option.
5144 The ARM rdi-share module.
5146 The Netware NLM debug server.
5148 *** Changes in GDB 6.4
5150 * New native configurations
5152 OpenBSD/arm arm*-*-openbsd*
5153 OpenBSD/mips64 mips64-*-openbsd*
5157 Morpho Technologies ms1 ms1-elf
5159 * New command line options
5161 --batch-silent As for --batch, but totally silent.
5162 --return-child-result The debugger will exist with the same value
5163 the child (debugged) program exited with.
5164 --eval-command COMMAND, -ex COMMAND
5165 Execute a single GDB CLI command. This may be
5166 specified multiple times and in conjunction
5167 with the --command (-x) option.
5169 * Deprecated commands removed
5171 The following commands, that were deprecated in 2000, have been
5175 set|show arm disassembly-flavor set|show arm disassembler
5176 othernames set arm disassembler
5177 set|show remotedebug set|show debug remote
5178 set|show archdebug set|show debug arch
5179 set|show eventdebug set|show debug event
5182 * New BSD user-level threads support
5184 It is now possible to debug programs using the user-level threads
5185 library on OpenBSD and FreeBSD. Currently supported (target)
5188 FreeBSD/amd64 x86_64-*-freebsd*
5189 FreeBSD/i386 i386-*-freebsd*
5190 OpenBSD/i386 i386-*-openbsd*
5192 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5193 are not yet supported.
5195 * New support for Matsushita MN10300 w/sim added
5196 (Work in progress). mn10300-elf.
5198 * REMOVED configurations and files
5200 VxWorks and the XDR protocol *-*-vxworks
5201 Motorola MCORE mcore-*-*
5202 National Semiconductor NS32000 ns32k-*-*
5204 * New "set print array-indexes" command
5206 After turning this setting "on", GDB prints the index of each element
5207 when displaying arrays. The default is "off" to preserve the previous
5210 * VAX floating point support
5212 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5214 * User-defined command support
5216 In addition to using $arg0..$arg9 for argument passing, it is now possible
5217 to use $argc to determine now many arguments have been passed. See the
5218 section on user-defined commands in the user manual for more information.
5220 *** Changes in GDB 6.3:
5222 * New command line option
5224 GDB now accepts -l followed by a number to set the timeout for remote
5227 * GDB works with GCC -feliminate-dwarf2-dups
5229 GDB now supports a more compact representation of DWARF-2 debug
5230 information using DW_FORM_ref_addr references. These are produced
5231 by GCC with the option -feliminate-dwarf2-dups and also by some
5232 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5233 to use -feliminate-dwarf2-dups.
5235 * Internationalization
5237 When supported by the host system, GDB will be built with
5238 internationalization (libintl). The task of marking up the sources is
5239 continued, we're looking forward to our first translation.
5243 Initial support for debugging programs compiled with the GNAT
5244 implementation of the Ada programming language has been integrated
5245 into GDB. In this release, support is limited to expression evaluation.
5247 * New native configurations
5249 GNU/Linux/m32r m32r-*-linux-gnu
5253 GDB's remote protocol now includes support for the 'p' packet. This
5254 packet is used to fetch individual registers from a remote inferior.
5256 * END-OF-LIFE registers[] compatibility module
5258 GDB's internal register infrastructure has been completely rewritten.
5259 The new infrastructure making possible the implementation of key new
5260 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5263 GDB 6.3 will be the last release to include the registers[]
5264 compatibility module that allowed out-of-date configurations to
5265 continue to work. This change directly impacts the following
5275 powerpc bdm protocol
5277 Unless there is activity to revive these configurations, they will be
5278 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5280 * OBSOLETE configurations and files
5282 Configurations that have been declared obsolete in this release have
5283 been commented out. Unless there is activity to revive these
5284 configurations, the next release of GDB will have their sources
5285 permanently REMOVED.
5294 *** Changes in GDB 6.2.1:
5296 * MIPS `break main; run' gave an heuristic-fence-post warning
5298 When attempting to run even a simple program, a warning about
5299 heuristic-fence-post being hit would be reported. This problem has
5302 * MIPS IRIX 'long double' crashed GDB
5304 When examining a long double variable, GDB would get a segmentation
5305 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5306 IRIX long double values).
5310 A bug in the VAX stack code was causing problems with the "next"
5311 command. This problem has been fixed.
5313 *** Changes in GDB 6.2:
5315 * Fix for ``many threads''
5317 On GNU/Linux systems that use the NPTL threads library, a program
5318 rapidly creating and deleting threads would confuse GDB leading to the
5321 ptrace: No such process.
5322 thread_db_get_info: cannot get thread info: generic error
5324 This problem has been fixed.
5326 * "-async" and "-noasync" options removed.
5328 Support for the broken "-noasync" option has been removed (it caused
5331 * New ``start'' command.
5333 This command runs the program until the beginning of the main procedure.
5335 * New BSD Kernel Data Access Library (libkvm) interface
5337 Using ``target kvm'' it is now possible to debug kernel core dumps and
5338 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5339 platforms. Currently supported (native-only) configurations are:
5341 FreeBSD/amd64 x86_64-*-freebsd*
5342 FreeBSD/i386 i?86-*-freebsd*
5343 NetBSD/i386 i?86-*-netbsd*
5344 NetBSD/m68k m68*-*-netbsd*
5345 NetBSD/sparc sparc-*-netbsd*
5346 OpenBSD/amd64 x86_64-*-openbsd*
5347 OpenBSD/i386 i?86-*-openbsd*
5348 OpenBSD/m68k m68*-openbsd*
5349 OpenBSD/sparc sparc-*-openbsd*
5351 * Signal trampoline code overhauled
5353 Many generic problems with GDB's signal handling code have been fixed.
5354 These include: backtraces through non-contiguous stacks; recognition
5355 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5356 call; backtrace through a signal trampoline; step into and out of
5357 signal handlers; and single-stepping in the signal trampoline.
5359 Please note that kernel bugs are a limiting factor here. These
5360 features have been shown to work on an s390 GNU/Linux system that
5361 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5363 * Cygwin support for DWARF 2 added.
5365 * New native configurations
5367 GNU/Linux/hppa hppa*-*-linux*
5368 OpenBSD/hppa hppa*-*-openbsd*
5369 OpenBSD/m68k m68*-*-openbsd*
5370 OpenBSD/m88k m88*-*-openbsd*
5371 OpenBSD/powerpc powerpc-*-openbsd*
5372 NetBSD/vax vax-*-netbsd*
5373 OpenBSD/vax vax-*-openbsd*
5375 * END-OF-LIFE frame compatibility module
5377 GDB's internal frame infrastructure has been completely rewritten.
5378 The new infrastructure making it possible to support key new features
5379 including DWARF 2 Call Frame Information. To aid in the task of
5380 migrating old configurations to this new infrastructure, a
5381 compatibility module, that allowed old configurations to continue to
5382 work, was also included.
5384 GDB 6.2 will be the last release to include this frame compatibility
5385 module. This change directly impacts the following configurations:
5395 Unless there is activity to revive these configurations, they will be
5396 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5398 * REMOVED configurations and files
5400 Sun 3, running SunOS 3 m68*-*-sunos3*
5401 Sun 3, running SunOS 4 m68*-*-sunos4*
5402 Sun 2, running SunOS 3 m68000-*-sunos3*
5403 Sun 2, running SunOS 4 m68000-*-sunos4*
5404 Motorola 680x0 running LynxOS m68*-*-lynxos*
5405 AT&T 3b1/Unix pc m68*-att-*
5406 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5407 decstation mips-dec-* mips-little-*
5408 riscos mips-*-riscos* mips-*-sysv*
5409 sonymips mips-sony-*
5410 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5412 *** Changes in GDB 6.1.1:
5414 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5416 The TUI (Text-mode User Interface) is now built as part of a default
5417 GDB configuration. It is enabled by either selecting the TUI with the
5418 command line option "-i=tui" or by running the separate "gdbtui"
5419 program. For more information on the TUI, see the manual "Debugging
5422 * Pending breakpoint support (also included in GDB 6.1)
5424 Support has been added to allow you to specify breakpoints in shared
5425 libraries that have not yet been loaded. If a breakpoint location
5426 cannot be found, and the "breakpoint pending" option is set to auto,
5427 GDB queries you if you wish to make the breakpoint pending on a future
5428 shared-library load. If and when GDB resolves the breakpoint symbol,
5429 the pending breakpoint is removed as one or more regular breakpoints
5432 Pending breakpoints are very useful for GCJ Java debugging.
5434 * Fixed ISO-C build problems
5436 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5437 non ISO-C code that stopped them being built using a more strict ISO-C
5438 compiler (e.g., IBM's C compiler).
5440 * Fixed build problem on IRIX 5
5442 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5443 wasn't able to compile compile on an IRIX 5 system.
5445 * Added execute permission to gdb/gdbserver/configure
5447 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5448 permission. This bug would cause configure to fail on a number of
5449 systems (Solaris, IRIX). Ref: server/519.
5451 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5453 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5454 has been updated to use constant array sizes.
5456 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5458 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5459 its generated DWARF Call Frame Info. This encoding was causing GDB to
5460 panic, that panic has been fixed. Ref: gdb/1628.
5462 * Fixed a problem when examining parameters in shared library code.
5464 When examining parameters in optimized shared library code generated
5465 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5466 not available''. GDB now correctly displays the variable's value.
5468 *** Changes in GDB 6.1:
5470 * Removed --with-mmalloc
5472 Support for the mmalloc memory manager has been removed, as it
5473 conflicted with the internal gdb byte cache.
5475 * Changes in AMD64 configurations
5477 The AMD64 target now includes the %cs and %ss registers. As a result
5478 the AMD64 remote protocol has changed; this affects the floating-point
5479 and SSE registers. If you rely on those registers for your debugging,
5480 you should upgrade gdbserver on the remote side.
5482 * Revised SPARC target
5484 The SPARC target has been completely revised, incorporating the
5485 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5486 support for LynxOS and SunOS 4 has been dropped. Calling functions
5487 from within GDB on operating systems with a non-executable stack
5488 (Solaris, OpenBSD) now works.
5492 GDB has a new C++ demangler which does a better job on the mangled
5493 names generated by current versions of g++. It also runs faster, so
5494 with this and other changes gdb should now start faster on large C++
5497 * DWARF 2 Location Expressions
5499 GDB support for location expressions has been extended to support function
5500 arguments and frame bases. Older versions of GDB could crash when they
5503 * C++ nested types and namespaces
5505 GDB's support for nested types and namespaces in C++ has been
5506 improved, especially if you use the DWARF 2 debugging format. (This
5507 is the default for recent versions of GCC on most platforms.)
5508 Specifically, if you have a class "Inner" defined within a class or
5509 namespace "Outer", then GDB realizes that the class's name is
5510 "Outer::Inner", not simply "Inner". This should greatly reduce the
5511 frequency of complaints about not finding RTTI symbols. In addition,
5512 if you are stopped at inside of a function defined within a namespace,
5513 GDB modifies its name lookup accordingly.
5515 * New native configurations
5517 NetBSD/amd64 x86_64-*-netbsd*
5518 OpenBSD/amd64 x86_64-*-openbsd*
5519 OpenBSD/alpha alpha*-*-openbsd*
5520 OpenBSD/sparc sparc-*-openbsd*
5521 OpenBSD/sparc64 sparc64-*-openbsd*
5523 * New debugging protocols
5525 M32R with SDI protocol m32r-*-elf*
5527 * "set prompt-escape-char" command deleted.
5529 The command "set prompt-escape-char" has been deleted. This command,
5530 and its very obscure effect on GDB's prompt, was never documented,
5531 tested, nor mentioned in the NEWS file.
5533 * OBSOLETE configurations and files
5535 Configurations that have been declared obsolete in this release have
5536 been commented out. Unless there is activity to revive these
5537 configurations, the next release of GDB will have their sources
5538 permanently REMOVED.
5540 Sun 3, running SunOS 3 m68*-*-sunos3*
5541 Sun 3, running SunOS 4 m68*-*-sunos4*
5542 Sun 2, running SunOS 3 m68000-*-sunos3*
5543 Sun 2, running SunOS 4 m68000-*-sunos4*
5544 Motorola 680x0 running LynxOS m68*-*-lynxos*
5545 AT&T 3b1/Unix pc m68*-att-*
5546 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5547 decstation mips-dec-* mips-little-*
5548 riscos mips-*-riscos* mips-*-sysv*
5549 sonymips mips-sony-*
5550 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5552 * REMOVED configurations and files
5554 SGI Irix-4.x mips-sgi-irix4 or iris4
5555 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5556 Z8000 simulator z8k-zilog-none or z8ksim
5557 Matsushita MN10200 w/simulator mn10200-*-*
5558 H8/500 simulator h8500-hitachi-hms or h8500hms
5559 HP/PA running BSD hppa*-*-bsd*
5560 HP/PA running OSF/1 hppa*-*-osf*
5561 HP/PA Pro target hppa*-*-pro*
5562 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5563 386BSD i[3456]86-*-bsd*
5564 Sequent family i[3456]86-sequent-sysv4*
5565 i[3456]86-sequent-sysv*
5566 i[3456]86-sequent-bsd*
5567 SPARC running LynxOS sparc-*-lynxos*
5568 SPARC running SunOS 4 sparc-*-sunos4*
5569 Tsqware Sparclet sparclet-*-*
5570 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5572 *** Changes in GDB 6.0:
5576 Support for debugging the Objective-C programming language has been
5577 integrated into GDB.
5579 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5581 DWARF 2's Call Frame Information makes available compiler generated
5582 information that more exactly describes the program's run-time stack.
5583 By using this information, GDB is able to provide more robust stack
5586 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5587 have been updated to use a new backtrace mechanism which includes
5588 DWARF 2 CFI support.
5592 GDB's remote protocol has been extended to include support for hosted
5593 file I/O (where the remote target uses GDB's file system). See GDB's
5594 remote protocol documentation for details.
5596 * All targets using the new architecture framework.
5598 All of GDB's targets have been updated to use the new internal
5599 architecture framework. The way is now open for future GDB releases
5600 to include cross-architecture native debugging support (i386 on amd64,
5603 * GNU/Linux's Thread Local Storage (TLS)
5605 GDB now includes support for for the GNU/Linux implementation of
5606 per-thread variables.
5608 * GNU/Linux's Native POSIX Thread Library (NPTL)
5610 GDB's thread code has been updated to work with either the new
5611 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5613 * Separate debug info.
5615 GDB, in conjunction with BINUTILS, now supports a mechanism for
5616 automatically loading debug information from a separate file. Instead
5617 of shipping full debug and non-debug versions of system libraries,
5618 system integrators can now instead ship just the stripped libraries
5619 and optional debug files.
5621 * DWARF 2 Location Expressions
5623 DWARF 2 Location Expressions allow the compiler to more completely
5624 describe the location of variables (even in optimized code) to the
5627 GDB now includes preliminary support for location expressions (support
5628 for DW_OP_piece is still missing).
5632 A number of long standing bugs that caused GDB to die while starting a
5633 Java application have been fixed. GDB's Java support is now
5634 considered "useable".
5636 * GNU/Linux support for fork, vfork, and exec.
5638 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5639 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5642 * GDB supports logging output to a file
5644 There are two new commands, "set logging" and "show logging", which can be
5645 used to capture GDB's output to a file.
5647 * The meaning of "detach" has changed for gdbserver
5649 The "detach" command will now resume the application, as documented. To
5650 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5653 * d10v, m68hc11 `regs' command deprecated
5655 The `info registers' command has been updated so that it displays the
5656 registers using a format identical to the old `regs' command.
5660 A new command, "maint set profile on/off", has been added. This command can
5661 be used to enable or disable profiling while running GDB, to profile a
5662 session or a set of commands. In addition there is a new configure switch,
5663 "--enable-profiling", which will cause GDB to be compiled with profiling
5664 data, for more informative profiling results.
5666 * Default MI syntax changed to "mi2".
5668 The default MI (machine interface) syntax, enabled by the command line
5669 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5670 "mi1", can be enabled by specifying the option "-i=mi1".
5672 Support for the original "mi0" syntax (included in GDB 5.0) has been
5675 Fix for gdb/192: removed extraneous space when displaying frame level.
5676 Fix for gdb/672: update changelist is now output in mi list format.
5677 Fix for gdb/702: a -var-assign that updates the value now shows up
5678 in a subsequent -var-update.
5680 * New native configurations.
5682 FreeBSD/amd64 x86_64-*-freebsd*
5684 * Multi-arched targets.
5686 HP/PA HPUX11 hppa*-*-hpux*
5687 Renesas M32R/D w/simulator m32r-*-elf*
5689 * OBSOLETE configurations and files
5691 Configurations that have been declared obsolete in this release have
5692 been commented out. Unless there is activity to revive these
5693 configurations, the next release of GDB will have their sources
5694 permanently REMOVED.
5696 Z8000 simulator z8k-zilog-none or z8ksim
5697 Matsushita MN10200 w/simulator mn10200-*-*
5698 H8/500 simulator h8500-hitachi-hms or h8500hms
5699 HP/PA running BSD hppa*-*-bsd*
5700 HP/PA running OSF/1 hppa*-*-osf*
5701 HP/PA Pro target hppa*-*-pro*
5702 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5703 Sequent family i[3456]86-sequent-sysv4*
5704 i[3456]86-sequent-sysv*
5705 i[3456]86-sequent-bsd*
5706 Tsqware Sparclet sparclet-*-*
5707 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5709 * REMOVED configurations and files
5712 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5713 IBM AIX PS/2 i[3456]86-*-aix
5714 i386 running Mach 3.0 i[3456]86-*-mach3*
5715 i386 running Mach i[3456]86-*-mach*
5716 i386 running OSF/1 i[3456]86-*osf1mk*
5717 HP/Apollo 68k Family m68*-apollo*-sysv*,
5719 m68*-hp-bsd*, m68*-hp-hpux*
5720 Argonaut Risc Chip (ARC) arc-*-*
5721 Mitsubishi D30V d30v-*-*
5722 Fujitsu FR30 fr30-*-elf*
5723 OS/9000 i[34]86-*-os9k
5724 I960 with MON960 i960-*-coff
5726 * MIPS $fp behavior changed
5728 The convenience variable $fp, for the MIPS, now consistently returns
5729 the address of the current frame's base. Previously, depending on the
5730 context, $fp could refer to either $sp or the current frame's base
5731 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5732 The GNU Source-Level Debugger''.
5734 *** Changes in GDB 5.3:
5736 * GNU/Linux shared library multi-threaded performance improved.
5738 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5739 `/proc', in preference to `ptrace' for memory reads. This may result
5740 in an improvement in the start-up time of multi-threaded, shared
5741 library applications when run under GDB. One GDB user writes: ``loads
5742 shared libs like mad''.
5744 * ``gdbserver'' now supports multi-threaded applications on some targets
5746 Support for debugging multi-threaded applications which use
5747 the GNU/Linux LinuxThreads package has been added for
5748 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5749 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5751 * GDB now supports C/C++ preprocessor macros.
5753 GDB now expands preprocessor macro invocations in C/C++ expressions,
5754 and provides various commands for showing macro definitions and how
5757 The new command `macro expand EXPRESSION' expands any macro
5758 invocations in expression, and shows the result.
5760 The new command `show macro MACRO-NAME' shows the definition of the
5761 macro named MACRO-NAME, and where it was defined.
5763 Most compilers don't include information about macros in the debugging
5764 information by default. In GCC 3.1, for example, you need to compile
5765 your program with the options `-gdwarf-2 -g3'. If the macro
5766 information is present in the executable, GDB will read it.
5768 * Multi-arched targets.
5770 DEC Alpha (partial) alpha*-*-*
5771 DEC VAX (partial) vax-*-*
5773 National Semiconductor NS32000 (partial) ns32k-*-*
5774 Motorola 68000 (partial) m68k-*-*
5775 Motorola MCORE mcore-*-*
5779 Fujitsu FRV architecture added by Red Hat frv*-*-*
5782 * New native configurations
5784 Alpha NetBSD alpha*-*-netbsd*
5785 SH NetBSD sh*-*-netbsdelf*
5786 MIPS NetBSD mips*-*-netbsd*
5787 UltraSPARC NetBSD sparc64-*-netbsd*
5789 * OBSOLETE configurations and files
5791 Configurations that have been declared obsolete in this release have
5792 been commented out. Unless there is activity to revive these
5793 configurations, the next release of GDB will have their sources
5794 permanently REMOVED.
5796 Mitsubishi D30V d30v-*-*
5797 OS/9000 i[34]86-*-os9k
5798 IBM AIX PS/2 i[3456]86-*-aix
5799 Fujitsu FR30 fr30-*-elf*
5800 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5801 Argonaut Risc Chip (ARC) arc-*-*
5802 i386 running Mach 3.0 i[3456]86-*-mach3*
5803 i386 running Mach i[3456]86-*-mach*
5804 i386 running OSF/1 i[3456]86-*osf1mk*
5805 HP/Apollo 68k Family m68*-apollo*-sysv*,
5807 m68*-hp-bsd*, m68*-hp-hpux*
5808 I960 with MON960 i960-*-coff
5810 * OBSOLETE languages
5812 CHILL, a Pascal like language used by telecommunications companies.
5814 * REMOVED configurations and files
5816 AMD 29k family via UDI a29k-amd-udi, udi29k
5817 A29K VxWorks a29k-*-vxworks
5818 AMD 29000 embedded, using EBMON a29k-none-none
5819 AMD 29000 embedded with COFF a29k-none-coff
5820 AMD 29000 embedded with a.out a29k-none-aout
5822 testsuite/gdb.hp/gdb.threads-hp/ directory
5824 * New command "set max-user-call-depth <nnn>"
5826 This command allows the user to limit the call depth of user-defined
5827 commands. The default is 1024.
5829 * Changes in FreeBSD/i386 native debugging.
5831 Support for the "generate-core-file" has been added.
5833 * New commands "dump", "append", and "restore".
5835 These commands allow data to be copied from target memory
5836 to a bfd-format or binary file (dump and append), and back
5837 from a file into memory (restore).
5839 * Improved "next/step" support on multi-processor Alpha Tru64.
5841 The previous single-step mechanism could cause unpredictable problems,
5842 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5843 of a software single-step mechanism prevents this.
5845 *** Changes in GDB 5.2.1:
5853 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5854 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5855 Fix, by Joel Brobecker imported from mainline.
5857 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5858 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5859 Fix, by Fred Fish, imported from mainline.
5861 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5862 Surprisingly enough, it works now.
5863 By Michal Ludvig, imported from mainline.
5865 i386 hardware watchpoint support:
5866 avoid misses on second run for some targets.
5867 By Pierre Muller, imported from mainline.
5869 *** Changes in GDB 5.2:
5871 * New command "set trust-readonly-sections on[off]".
5873 This command is a hint that tells gdb that read-only sections
5874 really are read-only (ie. that their contents will not change).
5875 In this mode, gdb will go to the object file rather than the
5876 target to read memory from read-only sections (such as ".text").
5877 This can be a significant performance improvement on some
5878 (notably embedded) targets.
5880 * New command "generate-core-file" (or "gcore").
5882 This new gdb command allows the user to drop a core file of the child
5883 process state at any time. So far it's been implemented only for
5884 GNU/Linux and Solaris, but should be relatively easily ported to other
5885 hosts. Argument is core file name (defaults to core.<pid>).
5887 * New command line option
5889 GDB now accepts --pid or -p followed by a process id.
5891 * Change in command line behavior -- corefiles vs. process ids.
5893 There is a subtle behavior in the way in which GDB handles
5894 command line arguments. The first non-flag argument is always
5895 a program to debug, but the second non-flag argument may either
5896 be a corefile or a process id. Previously, GDB would attempt to
5897 open the second argument as a corefile, and if that failed, would
5898 issue a superfluous error message and then attempt to attach it as
5899 a process. Now, if the second argument begins with a non-digit,
5900 it will be treated as a corefile. If it begins with a digit,
5901 GDB will attempt to attach it as a process, and if no such process
5902 is found, will then attempt to open it as a corefile.
5904 * Changes in ARM configurations.
5906 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5907 configuration is fully multi-arch.
5909 * New native configurations
5911 ARM NetBSD arm*-*-netbsd*
5912 x86 OpenBSD i[3456]86-*-openbsd*
5913 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5914 Sparc64 running FreeBSD sparc64-*-freebsd*
5918 Sanyo XStormy16 xstormy16-elf
5920 * OBSOLETE configurations and files
5922 Configurations that have been declared obsolete in this release have
5923 been commented out. Unless there is activity to revive these
5924 configurations, the next release of GDB will have their sources
5925 permanently REMOVED.
5927 AMD 29k family via UDI a29k-amd-udi, udi29k
5928 A29K VxWorks a29k-*-vxworks
5929 AMD 29000 embedded, using EBMON a29k-none-none
5930 AMD 29000 embedded with COFF a29k-none-coff
5931 AMD 29000 embedded with a.out a29k-none-aout
5933 testsuite/gdb.hp/gdb.threads-hp/ directory
5935 * REMOVED configurations and files
5937 TI TMS320C80 tic80-*-*
5939 PowerPC Solaris powerpcle-*-solaris*
5940 PowerPC Windows NT powerpcle-*-cygwin32
5941 PowerPC Netware powerpc-*-netware*
5942 Harris/CXUX m88k m88*-harris-cxux*
5943 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5944 ns32k-utek-sysv* ns32k-utek-*
5945 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5946 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5947 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5948 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5949 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5951 * Changes to command line processing
5953 The new `--args' feature can be used to specify command-line arguments
5954 for the inferior from gdb's command line.
5956 * Changes to key bindings
5958 There is a new `operate-and-get-next' function bound to `C-o'.
5960 *** Changes in GDB 5.1.1
5962 Fix compile problem on DJGPP.
5964 Fix a problem with floating-point registers on the i386 being
5967 Fix to stop GDB crashing on .debug_str debug info.
5969 Numerous documentation fixes.
5971 Numerous testsuite fixes.
5973 *** Changes in GDB 5.1:
5975 * New native configurations
5977 Alpha FreeBSD alpha*-*-freebsd*
5978 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5979 MIPS GNU/Linux mips*-*-linux*
5980 MIPS SGI Irix 6.x mips*-sgi-irix6*
5981 ia64 AIX ia64-*-aix*
5982 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5986 Motorola 68HC11 and 68HC12 m68hc11-elf
5988 UltraSparc running GNU/Linux sparc64-*-linux*
5990 * OBSOLETE configurations and files
5992 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5993 Harris/CXUX m88k m88*-harris-cxux*
5994 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5995 ns32k-utek-sysv* ns32k-utek-*
5996 TI TMS320C80 tic80-*-*
5998 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5999 PowerPC Solaris powerpcle-*-solaris*
6000 PowerPC Windows NT powerpcle-*-cygwin32
6001 PowerPC Netware powerpc-*-netware*
6002 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6003 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6004 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6005 Apple Macintosh (MPW) host N/A
6007 stuff.c (Program to stuff files into a specially prepared space in kdb)
6008 kdb-start.c (Main loop for the standalone kernel debugger)
6010 Configurations that have been declared obsolete in this release have
6011 been commented out. Unless there is activity to revive these
6012 configurations, the next release of GDB will have their sources
6013 permanently REMOVED.
6015 * REMOVED configurations and files
6017 Altos 3068 m68*-altos-*
6018 Convex c1-*-*, c2-*-*
6020 ARM RISCix arm-*-* (as host)
6024 * GDB has been converted to ISO C.
6026 GDB's source code has been converted to ISO C. In particular, the
6027 sources are fully protoized, and rely on standard headers being
6032 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6034 * The MI enabled by default.
6036 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6037 revised and enabled by default. Packages which use GDB as a debugging
6038 engine behind a UI or another front end are encouraged to switch to
6039 using the GDB/MI interface, instead of the old annotations interface
6040 which is now deprecated.
6042 * Support for debugging Pascal programs.
6044 GDB now includes support for debugging Pascal programs. The following
6045 main features are supported:
6047 - Pascal-specific data types such as sets;
6049 - automatic recognition of Pascal sources based on file-name
6052 - Pascal-style display of data types, variables, and functions;
6054 - a Pascal expression parser.
6056 However, some important features are not yet supported.
6058 - Pascal string operations are not supported at all;
6060 - there are some problems with boolean types;
6062 - Pascal type hexadecimal constants are not supported
6063 because they conflict with the internal variables format;
6065 - support for Pascal objects and classes is not full yet;
6067 - unlike Pascal, GDB is case-sensitive for symbol names.
6069 * Changes in completion.
6071 Commands such as `shell', `run' and `set args', which pass arguments
6072 to inferior programs, now complete on file names, similar to what
6073 users expect at the shell prompt.
6075 Commands which accept locations, such as `disassemble', `print',
6076 `breakpoint', `until', etc. now complete on filenames as well as
6077 program symbols. Thus, if you type "break foob TAB", and the source
6078 files linked into the programs include `foobar.c', that file name will
6079 be one of the candidates for completion. However, file names are not
6080 considered for completion after you typed a colon that delimits a file
6081 name from a name of a function in that file, as in "break foo.c:bar".
6083 `set demangle-style' completes on available demangling styles.
6085 * New platform-independent commands:
6087 It is now possible to define a post-hook for a command as well as a
6088 hook that runs before the command. For more details, see the
6089 documentation of `hookpost' in the GDB manual.
6091 * Changes in GNU/Linux native debugging.
6093 Support for debugging multi-threaded programs has been completely
6094 revised for all platforms except m68k and sparc. You can now debug as
6095 many threads as your system allows you to have.
6097 Attach/detach is supported for multi-threaded programs.
6099 Support for SSE registers was added for x86. This doesn't work for
6100 multi-threaded programs though.
6102 * Changes in MIPS configurations.
6104 Multi-arch support is enabled for all MIPS configurations.
6106 GDB can now be built as native debugger on SGI Irix 6.x systems for
6107 debugging n32 executables. (Debugging 64-bit executables is not yet
6110 * Unified support for hardware watchpoints in all x86 configurations.
6112 Most (if not all) native x86 configurations support hardware-assisted
6113 breakpoints and watchpoints in a unified manner. This support
6114 implements debug register sharing between watchpoints, which allows to
6115 put a virtually infinite number of watchpoints on the same address,
6116 and also supports watching regions up to 16 bytes with several debug
6119 The new maintenance command `maintenance show-debug-regs' toggles
6120 debugging print-outs in functions that insert, remove, and test
6121 watchpoints and hardware breakpoints.
6123 * Changes in the DJGPP native configuration.
6125 New command ``info dos sysinfo'' displays assorted information about
6126 the CPU, OS, memory, and DPMI server.
6128 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6129 display information about segment descriptors stored in GDT, LDT, and
6132 New commands ``info dos pde'' and ``info dos pte'' display entries
6133 from Page Directory and Page Tables (for now works with CWSDPMI only).
6134 New command ``info dos address-pte'' displays the Page Table entry for
6135 a given linear address.
6137 GDB can now pass command lines longer than 126 characters to the
6138 program being debugged (requires an update to the libdbg.a library
6139 which is part of the DJGPP development kit).
6141 DWARF2 debug info is now supported.
6143 It is now possible to `step' and `next' through calls to `longjmp'.
6145 * Changes in documentation.
6147 All GDB documentation was converted to GFDL, the GNU Free
6148 Documentation License.
6150 Tracepoints-related commands are now fully documented in the GDB
6153 TUI, the Text-mode User Interface, is now documented in the manual.
6155 Tracepoints-related commands are now fully documented in the GDB
6158 The "GDB Internals" manual now has an index. It also includes
6159 documentation of `ui_out' functions, GDB coding standards, x86
6160 hardware watchpoints, and memory region attributes.
6162 * GDB's version number moved to ``version.in''
6164 The Makefile variable VERSION has been replaced by the file
6165 ``version.in''. People creating GDB distributions should update the
6166 contents of this file.
6170 GUD support is now a standard part of the EMACS distribution.
6172 *** Changes in GDB 5.0:
6174 * Improved support for debugging FP programs on x86 targets
6176 Unified and much-improved support for debugging floating-point
6177 programs on all x86 targets. In particular, ``info float'' now
6178 displays the FP registers in the same format on all x86 targets, with
6179 greater level of detail.
6181 * Improvements and bugfixes in hardware-assisted watchpoints
6183 It is now possible to watch array elements, struct members, and
6184 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6185 on x86 targets no longer erroneously trigger when the address is
6188 * Improvements in the native DJGPP version of GDB
6190 The distribution now includes all the scripts and auxiliary files
6191 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6192 machines ``out of the box''.
6194 The DJGPP version can now debug programs that use signals. It is
6195 possible to catch signals that happened in the debuggee, deliver
6196 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6197 would kill the program being debugged.) Programs that hook hardware
6198 interrupts (keyboard, timer, etc.) can also be debugged.
6200 It is now possible to debug DJGPP programs that redirect their
6201 standard handles or switch them to raw (as opposed to cooked) mode, or
6202 even close them. The command ``run < foo > bar'' works as expected,
6203 and ``info terminal'' reports useful information about the debuggee's
6204 terminal, including raw/cooked mode, redirection, etc.
6206 The DJGPP version now uses termios functions for console I/O, which
6207 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6210 DOS-style file names with drive letters are now fully supported by
6213 It is now possible to debug DJGPP programs that switch their working
6214 directory. It is also possible to rerun the debuggee any number of
6215 times without restarting GDB; thus, you can use the same setup,
6216 breakpoints, etc. for many debugging sessions.
6218 * New native configurations
6220 ARM GNU/Linux arm*-*-linux*
6221 PowerPC GNU/Linux powerpc-*-linux*
6225 Motorola MCore mcore-*-*
6226 x86 VxWorks i[3456]86-*-vxworks*
6227 PowerPC VxWorks powerpc-*-vxworks*
6228 TI TMS320C80 tic80-*-*
6230 * OBSOLETE configurations
6232 Altos 3068 m68*-altos-*
6233 Convex c1-*-*, c2-*-*
6235 ARM RISCix arm-*-* (as host)
6238 Configurations that have been declared obsolete will be commented out,
6239 but the code will be left in place. If there is no activity to revive
6240 these configurations before the next release of GDB, the sources will
6241 be permanently REMOVED.
6243 * Gould support removed
6245 Support for the Gould PowerNode and NP1 has been removed.
6247 * New features for SVR4
6249 On SVR4 native platforms (such as Solaris), if you attach to a process
6250 without first loading a symbol file, GDB will now attempt to locate and
6251 load symbols from the running process's executable file.
6253 * Many C++ enhancements
6255 C++ support has been greatly improved. Overload resolution now works properly
6256 in almost all cases. RTTI support is on the way.
6258 * Remote targets can connect to a sub-program
6260 A popen(3) style serial-device has been added. This device starts a
6261 sub-process (such as a stand-alone simulator) and then communicates
6262 with that. The sub-program to run is specified using the syntax
6263 ``|<program> <args>'' vis:
6265 (gdb) set remotedebug 1
6266 (gdb) target extended-remote |mn10300-elf-sim program-args
6268 * MIPS 64 remote protocol
6270 A long standing bug in the mips64 remote protocol where by GDB
6271 expected certain 32 bit registers (ex SR) to be transfered as 32
6272 instead of 64 bits has been fixed.
6274 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6275 added to provide backward compatibility with older versions of GDB.
6277 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6279 The command ``set remotebinarydownload'' command has been replaced by
6280 ``set remote X-packet''. Other commands in ``set remote'' family
6281 include ``set remote P-packet''.
6283 * Breakpoint commands accept ranges.
6285 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6286 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6287 ``tracepoint passcount'' also accepts a range of tracepoints.
6289 * ``apropos'' command added.
6291 The ``apropos'' command searches through command names and
6292 documentation strings, printing out matches, making it much easier to
6293 try to find a command that does what you are looking for.
6297 A new machine oriented interface (MI) has been added to GDB. This
6298 interface is designed for debug environments running GDB as a separate
6299 process. This is part of the long term libGDB project. See the
6300 "GDB/MI" chapter of the GDB manual for further information. It can be
6301 enabled by configuring with:
6303 .../configure --enable-gdbmi
6305 *** Changes in GDB-4.18:
6307 * New native configurations
6309 HP-UX 10.20 hppa*-*-hpux10.20
6310 HP-UX 11.x hppa*-*-hpux11.0*
6311 M68K GNU/Linux m68*-*-linux*
6315 Fujitsu FR30 fr30-*-elf*
6316 Intel StrongARM strongarm-*-*
6317 Mitsubishi D30V d30v-*-*
6319 * OBSOLETE configurations
6321 Gould PowerNode, NP1 np1-*-*, pn-*-*
6323 Configurations that have been declared obsolete will be commented out,
6324 but the code will be left in place. If there is no activity to revive
6325 these configurations before the next release of GDB, the sources will
6326 be permanently REMOVED.
6330 As a compatibility experiment, GDB's source files buildsym.h and
6331 buildsym.c have been converted to pure standard C, no longer
6332 containing any K&R compatibility code. We believe that all systems in
6333 use today either come with a standard C compiler, or have a GCC port
6334 available. If this is not true, please report the affected
6335 configuration to bug-gdb@gnu.org immediately. See the README file for
6336 information about getting a standard C compiler if you don't have one
6341 GDB now uses readline 2.2.
6343 * set extension-language
6345 You can now control the mapping between filename extensions and source
6346 languages by using the `set extension-language' command. For instance,
6347 you can ask GDB to treat .c files as C++ by saying
6348 set extension-language .c c++
6349 The command `info extensions' lists all of the recognized extensions
6350 and their associated languages.
6352 * Setting processor type for PowerPC and RS/6000
6354 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6355 you can use the `set processor' command to specify what variant of the
6356 PowerPC family you are debugging. The command
6360 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6361 following PowerPC and RS6000 variants:
6363 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6364 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6366 403GC IBM PowerPC 403GC
6367 505 Motorola PowerPC 505
6368 860 Motorola PowerPC 860 or 850
6369 601 Motorola PowerPC 601
6370 602 Motorola PowerPC 602
6371 603 Motorola/IBM PowerPC 603 or 603e
6372 604 Motorola PowerPC 604 or 604e
6373 750 Motorola/IBM PowerPC 750 or 750
6375 At the moment, this command just tells GDB what to name the
6376 special-purpose processor registers. Since almost all the affected
6377 registers are inaccessible to user-level programs, this command is
6378 only useful for remote debugging in its present form.
6382 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6383 more extensive support for HP-UX. Added features include shared
6384 library support, kernel threads and hardware watchpoints for 11.00,
6385 support for HP's ANSI C and C++ compilers, and a compatibility mode
6386 for xdb and dbx commands.
6390 HP's donation includes the new concept of catchpoints, which is a
6391 generalization of the old catch command. On HP-UX, it is now possible
6392 to catch exec, fork, and vfork, as well as library loading.
6394 This means that the existing catch command has changed; its first
6395 argument now specifies the type of catch to be set up. See the
6396 output of "help catch" for a list of catchpoint types.
6398 * Debugging across forks
6400 On HP-UX, you can choose which process to debug when a fork() happens
6405 HP has donated a curses-based terminal user interface (TUI). To get
6406 it, build with --enable-tui. Although this can be enabled for any
6407 configuration, at present it only works for native HP debugging.
6409 * GDB remote protocol additions
6411 A new protocol packet 'X' that writes binary data is now available.
6412 Default behavior is to try 'X', then drop back to 'M' if the stub
6413 fails to respond. The settable variable `remotebinarydownload'
6414 allows explicit control over the use of 'X'.
6416 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6417 full 64-bit address. The command
6419 set remoteaddresssize 32
6421 can be used to revert to the old behaviour. For existing remote stubs
6422 the change should not be noticed, as the additional address information
6425 In order to assist in debugging stubs, you may use the maintenance
6426 command `packet' to send any text string to the stub. For instance,
6428 maint packet heythere
6430 sends the packet "$heythere#<checksum>". Note that it is very easy to
6431 disrupt a debugging session by sending the wrong packet at the wrong
6434 The compare-sections command allows you to compare section data on the
6435 target to what is in the executable file without uploading or
6436 downloading, by comparing CRC checksums.
6438 * Tracing can collect general expressions
6440 You may now collect general expressions at tracepoints. This requires
6441 further additions to the target-side stub; see tracepoint.c and
6442 doc/agentexpr.texi for further details.
6444 * mask-address variable for Mips
6446 For Mips targets, you may control the zeroing of the upper 32 bits of
6447 a 64-bit address by entering `set mask-address on'. This is mainly
6448 of interest to users of embedded R4xxx and R5xxx processors.
6450 * Higher serial baud rates
6452 GDB's serial code now allows you to specify baud rates 57600, 115200,
6453 230400, and 460800 baud. (Note that your host system may not be able
6454 to achieve all of these rates.)
6458 The i960 configuration now includes an initial implementation of a
6459 builtin simulator, contributed by Jim Wilson.
6462 *** Changes in GDB-4.17:
6464 * New native configurations
6466 Alpha GNU/Linux alpha*-*-linux*
6467 Unixware 2.x i[3456]86-unixware2*
6468 Irix 6.x mips*-sgi-irix6*
6469 PowerPC GNU/Linux powerpc-*-linux*
6470 PowerPC Solaris powerpcle-*-solaris*
6471 Sparc GNU/Linux sparc-*-linux*
6472 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6476 Argonaut Risc Chip (ARC) arc-*-*
6477 Hitachi H8/300S h8300*-*-*
6478 Matsushita MN10200 w/simulator mn10200-*-*
6479 Matsushita MN10300 w/simulator mn10300-*-*
6480 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6481 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6482 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6483 Mitsubishi D10V w/simulator d10v-*-*
6484 Mitsubishi M32R/D w/simulator m32r-*-elf*
6485 Tsqware Sparclet sparclet-*-*
6486 NEC V850 w/simulator v850-*-*
6488 * New debugging protocols
6490 ARM with RDI protocol arm*-*-*
6491 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6492 DDB and LSI variants of PMON protocol mips*-*-*
6493 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6494 PowerPC with SDS protocol powerpc{,le}-*-eabi
6495 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6499 All configurations can now understand and use the DWARF 2 debugging
6500 format. The choice is automatic, if the symbol file contains DWARF 2
6505 GDB now includes basic Java language support. This support is
6506 only useful with Java compilers that produce native machine code.
6508 * solib-absolute-prefix and solib-search-path
6510 For SunOS and SVR4 shared libraries, you may now set the prefix for
6511 loading absolute shared library symbol files, and the search path for
6512 locating non-absolute shared library symbol files.
6514 * Live range splitting
6516 GDB can now effectively debug code for which GCC has performed live
6517 range splitting as part of its optimization. See gdb/doc/LRS for
6518 more details on the expected format of the stabs information.
6522 GDB's support for the GNU Hurd, including thread debugging, has been
6523 updated to work with current versions of the Hurd.
6527 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6528 instruction set. ARM GDB automatically detects when Thumb
6529 instructions are in use, and adjusts disassembly and backtracing
6534 GDB's MIPS target configurations now handle the MIP16 16-bit
6539 GDB now includes support for overlays; if an executable has been
6540 linked such that multiple sections are based at the same address, GDB
6541 will decide which section to use for symbolic info. You can choose to
6542 control the decision manually, using overlay commands, or implement
6543 additional target-side support and use "overlay load-target" to bring
6544 in the overlay mapping. Do "help overlay" for more detail.
6548 The command "info symbol <address>" displays information about
6549 the symbol at the specified address.
6553 The standard remote protocol now includes an extension that allows
6554 asynchronous collection and display of trace data. This requires
6555 extensive support in the target-side debugging stub. Tracing mode
6556 includes a new interaction mode in GDB and new commands: see the
6557 file tracepoint.c for more details.
6561 Configurations for embedded MIPS now include a simulator contributed
6562 by Cygnus Solutions. The simulator supports the instruction sets
6563 of most MIPS variants.
6567 Sparc configurations may now include the ERC32 simulator contributed
6568 by the European Space Agency. The simulator is not built into
6569 Sparc targets by default; configure with --enable-sim to include it.
6573 For target configurations that may include multiple variants of a
6574 basic architecture (such as MIPS and SH), you may now set the
6575 architecture explicitly. "set arch" sets, "info arch" lists
6576 the possible architectures.
6578 *** Changes in GDB-4.16:
6580 * New native configurations
6582 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6583 M68K NetBSD m68k-*-netbsd*
6584 PowerPC AIX 4.x powerpc-*-aix*
6585 PowerPC MacOS powerpc-*-macos*
6586 PowerPC Windows NT powerpcle-*-cygwin32
6587 RS/6000 AIX 4.x rs6000-*-aix4*
6591 ARM with RDP protocol arm-*-*
6592 I960 with MON960 i960-*-coff
6593 MIPS VxWorks mips*-*-vxworks*
6594 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6595 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6597 Matra Sparclet sparclet-*-*
6601 The powerpc-eabi configuration now includes the PSIM simulator,
6602 contributed by Andrew Cagney, with assistance from Mike Meissner.
6603 PSIM is a very elaborate model of the PowerPC, including not only
6604 basic instruction set execution, but also details of execution unit
6605 performance and I/O hardware. See sim/ppc/README for more details.
6609 GDB now works with Solaris 2.5.
6611 * Windows 95/NT native
6613 GDB will now work as a native debugger on Windows 95 and Windows NT.
6614 To build it from source, you must use the "gnu-win32" environment,
6615 which uses a DLL to emulate enough of Unix to run the GNU tools.
6616 Further information, binaries, and sources are available at
6617 ftp.cygnus.com, under pub/gnu-win32.
6619 * dont-repeat command
6621 If a user-defined command includes the command `dont-repeat', then the
6622 command will not be repeated if the user just types return. This is
6623 useful if the command is time-consuming to run, so that accidental
6624 extra keystrokes don't run the same command many times.
6626 * Send break instead of ^C
6628 The standard remote protocol now includes an option to send a break
6629 rather than a ^C to the target in order to interrupt it. By default,
6630 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6632 * Remote protocol timeout
6634 The standard remote protocol includes a new variable `remotetimeout'
6635 that allows you to set the number of seconds before GDB gives up trying
6636 to read from the target. The default value is 2.
6638 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6640 By default GDB will automatically keep track of objects as they are
6641 loaded and unloaded by the dynamic linker. By using the command `set
6642 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6643 when shared library events occur, thus allowing you to set breakpoints
6644 in shared libraries which are explicitly loaded by the inferior.
6646 Note this feature does not work on hpux8. On hpux9 you must link
6647 /usr/lib/end.o into your program. This feature should work
6648 automatically on hpux10.
6650 * Irix 5.x hardware watchpoint support
6652 Irix 5 configurations now support the use of hardware watchpoints.
6654 * Mips protocol "SYN garbage limit"
6656 When debugging a Mips target using the `target mips' protocol, you
6657 may set the number of characters that GDB will ignore by setting
6658 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6659 every character. The default value is 1050.
6661 * Recording and replaying remote debug sessions
6663 If you set `remotelogfile' to the name of a file, gdb will write to it
6664 a recording of a remote debug session. This recording may then be
6665 replayed back to gdb using "gdbreplay". See gdbserver/README for
6666 details. This is useful when you have a problem with GDB while doing
6667 remote debugging; you can make a recording of the session and send it
6668 to someone else, who can then recreate the problem.
6670 * Speedups for remote debugging
6672 GDB includes speedups for downloading and stepping MIPS systems using
6673 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6674 and more efficient S-record downloading.
6676 * Memory use reductions and statistics collection
6678 GDB now uses less memory and reports statistics about memory usage.
6679 Try the `maint print statistics' command, for example.
6681 *** Changes in GDB-4.15:
6683 * Psymtabs for XCOFF
6685 The symbol reader for AIX GDB now uses partial symbol tables. This
6686 can greatly improve startup time, especially for large executables.
6688 * Remote targets use caching
6690 Remote targets now use a data cache to speed up communication with the
6691 remote side. The data cache could lead to incorrect results because
6692 it doesn't know about volatile variables, thus making it impossible to
6693 debug targets which use memory mapped I/O devices. `set remotecache
6694 off' turns the data cache off.
6696 * Remote targets may have threads
6698 The standard remote protocol now includes support for multiple threads
6699 in the target system, using new protocol commands 'H' and 'T'. See
6700 gdb/remote.c for details.
6704 If GDB is configured with `--enable-netrom', then it will include
6705 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6706 acts as though it is a bank of ROM on the target board, but you can
6707 write into it over the network. GDB's support consists only of
6708 support for fast loading into the emulated ROM; to debug, you must use
6709 another protocol, such as standard remote protocol. The usual
6710 sequence is something like
6712 target nrom <netrom-hostname>
6714 target remote <netrom-hostname>:1235
6718 GDB now includes support for the Apple Macintosh, as a host only. It
6719 may be run as either an MPW tool or as a standalone application, and
6720 it can debug through the serial port. All the usual GDB commands are
6721 available, but to the target command, you must supply "serial" as the
6722 device type instead of "/dev/ttyXX". See mpw-README in the main
6723 directory for more information on how to build. The MPW configuration
6724 scripts */mpw-config.in support only a few targets, and only the
6725 mips-idt-ecoff target has been tested.
6729 GDB configuration now uses autoconf. This is not user-visible,
6730 but does simplify configuration and building.
6734 GDB now supports hpux10.
6736 *** Changes in GDB-4.14:
6738 * New native configurations
6740 x86 FreeBSD i[345]86-*-freebsd
6741 x86 NetBSD i[345]86-*-netbsd
6742 NS32k NetBSD ns32k-*-netbsd
6743 Sparc NetBSD sparc-*-netbsd
6747 A29K VxWorks a29k-*-vxworks
6748 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6749 CPU32 EST-300 emulator m68*-*-est*
6750 PowerPC ELF powerpc-*-elf
6753 * Alpha OSF/1 support for procfs
6755 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6756 possible to attach to running processes. As the mounting of the /proc
6757 filesystem is optional on the Alpha, GDB automatically determines
6758 the availability of /proc during startup. This can lead to problems
6759 if /proc is unmounted after GDB has been started.
6761 * Arguments to user-defined commands
6763 User commands may accept up to 10 arguments separated by whitespace.
6764 Arguments are accessed within the user command via $arg0..$arg9. A
6767 print $arg0 + $arg1 + $arg2
6769 To execute the command use:
6772 Defines the command "adder" which prints the sum of its three arguments.
6773 Note the arguments are text substitutions, so they may reference variables,
6774 use complex expressions, or even perform inferior function calls.
6776 * New `if' and `while' commands
6778 This makes it possible to write more sophisticated user-defined
6779 commands. Both commands take a single argument, which is the
6780 expression to evaluate, and must be followed by the commands to
6781 execute, one per line, if the expression is nonzero, the list being
6782 terminated by the word `end'. The `if' command list may include an
6783 `else' word, which causes the following commands to be executed only
6784 if the expression is zero.
6786 * Fortran source language mode
6788 GDB now includes partial support for Fortran 77. It will recognize
6789 Fortran programs and can evaluate a subset of Fortran expressions, but
6790 variables and functions may not be handled correctly. GDB will work
6791 with G77, but does not yet know much about symbols emitted by other
6794 * Better HPUX support
6796 Most debugging facilities now work on dynamic executables for HPPAs
6797 running hpux9 or later. You can attach to running dynamically linked
6798 processes, but by default the dynamic libraries will be read-only, so
6799 for instance you won't be able to put breakpoints in them. To change
6800 that behavior do the following before running the program:
6806 This will cause the libraries to be mapped private and read-write.
6807 To revert to the normal behavior, do this:
6813 You cannot set breakpoints or examine data in the library until after
6814 the library is loaded if the function/data symbols do not have
6817 GDB can now also read debug symbols produced by the HP C compiler on
6818 HPPAs (sorry, no C++, Fortran or 68k support).
6820 * Target byte order now dynamically selectable
6822 You can choose which byte order to use with a target system, via the
6823 commands "set endian big" and "set endian little", and you can see the
6824 current setting by using "show endian". You can also give the command
6825 "set endian auto", in which case GDB will use the byte order
6826 associated with the executable. Currently, only embedded MIPS
6827 configurations support dynamic selection of target byte order.
6829 * New DOS host serial code
6831 This version uses DPMI interrupts to handle buffered I/O, so you
6832 no longer need to run asynctsr when debugging boards connected to
6835 *** Changes in GDB-4.13:
6837 * New "complete" command
6839 This lists all the possible completions for the rest of the line, if it
6840 were to be given as a command itself. This is intended for use by emacs.
6842 * Trailing space optional in prompt
6844 "set prompt" no longer adds a space for you after the prompt you set. This
6845 allows you to set a prompt which ends in a space or one that does not.
6847 * Breakpoint hit counts
6849 "info break" now displays a count of the number of times the breakpoint
6850 has been hit. This is especially useful in conjunction with "ignore"; you
6851 can ignore a large number of breakpoint hits, look at the breakpoint info
6852 to see how many times the breakpoint was hit, then run again, ignoring one
6853 less than that number, and this will get you quickly to the last hit of
6856 * Ability to stop printing at NULL character
6858 "set print null-stop" will cause GDB to stop printing the characters of
6859 an array when the first NULL is encountered. This is useful when large
6860 arrays actually contain only short strings.
6862 * Shared library breakpoints
6864 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6865 breakpoints in shared libraries before the executable is run.
6867 * Hardware watchpoints
6869 There is a new hardware breakpoint for the watch command for sparclite
6870 targets. See gdb/sparclite/hw_breakpoint.note.
6872 Hardware watchpoints are also now supported under GNU/Linux.
6876 Annotations have been added. These are for use with graphical interfaces,
6877 and are still experimental. Currently only gdba.el uses these.
6879 * Improved Irix 5 support
6881 GDB now works properly with Irix 5.2.
6883 * Improved HPPA support
6885 GDB now works properly with the latest GCC and GAS.
6887 * New native configurations
6889 Sequent PTX4 i[34]86-sequent-ptx4
6890 HPPA running OSF/1 hppa*-*-osf*
6891 Atari TT running SVR4 m68*-*-sysv4*
6892 RS/6000 LynxOS rs6000-*-lynxos*
6896 OS/9000 i[34]86-*-os9k
6897 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6900 * Hitachi SH7000 and E7000-PC ICE support
6902 There is now support for communicating with the Hitachi E7000-PC ICE.
6903 This is available automatically when GDB is configured for the SH.
6907 As usual, a variety of small fixes and improvements, both generic
6908 and configuration-specific. See the ChangeLog for more detail.
6910 *** Changes in GDB-4.12:
6912 * Irix 5 is now supported
6916 GDB-4.12 on the HPPA has a number of changes which make it unable
6917 to debug the output from the currently released versions of GCC and
6918 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6919 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6920 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6923 *** Changes in GDB-4.11:
6925 * User visible changes:
6929 The "set remotedebug" option is now consistent between the mips remote
6930 target, remote targets using the gdb-specific protocol, UDI (AMD's
6931 debug protocol for the 29k) and the 88k bug monitor. It is now an
6932 integer specifying a debug level (normally 0 or 1, but 2 means more
6933 debugging info for the mips target).
6935 * DEC Alpha native support
6937 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6938 debug info, but GDB works fairly well with the DEC compiler and should
6939 work with a future GCC release. See the README file for a few
6940 Alpha-specific notes.
6942 * Preliminary thread implementation
6944 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6946 * LynxOS native and target support for 386
6948 This release has been hosted on LynxOS 2.2, and also can be configured
6949 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6952 * Improvements in C++ mangling/demangling.
6954 This release has much better g++ debugging, specifically in name
6955 mangling/demangling, virtual function calls, print virtual table,
6956 call methods, ...etc.
6958 *** Changes in GDB-4.10:
6960 * User visible changes:
6962 Remote debugging using the GDB-specific (`target remote') protocol now
6963 supports the `load' command. This is only useful if you have some
6964 other way of getting the stub to the target system, and you can put it
6965 somewhere in memory where it won't get clobbered by the download.
6967 Filename completion now works.
6969 When run under emacs mode, the "info line" command now causes the
6970 arrow to point to the line specified. Also, "info line" prints
6971 addresses in symbolic form (as well as hex).
6973 All vxworks based targets now support a user settable option, called
6974 vxworks-timeout. This option represents the number of seconds gdb
6975 should wait for responses to rpc's. You might want to use this if
6976 your vxworks target is, perhaps, a slow software simulator or happens
6977 to be on the far side of a thin network line.
6981 This release contains support for using a DEC alpha as a GDB host for
6982 cross debugging. Native alpha debugging is not supported yet.
6985 *** Changes in GDB-4.9:
6989 This is the first GDB release which is accompanied by a matching testsuite.
6990 The testsuite requires installation of dejagnu, which should be available
6991 via ftp from most sites that carry GNU software.
6995 'Cfront' style demangling has had its name changed to 'ARM' style, to
6996 emphasize that it was written from the specifications in the C++ Annotated
6997 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6998 disclaimers, it still generated too much confusion with users attempting to
6999 use gdb with AT&T cfront.
7003 GDB now uses a standard remote interface to a simulator library.
7004 So far, the library contains simulators for the Zilog Z8001/2, the
7005 Hitachi H8/300, H8/500 and Super-H.
7007 * New targets supported
7009 H8/300 simulator h8300-hitachi-hms or h8300hms
7010 H8/500 simulator h8500-hitachi-hms or h8500hms
7011 SH simulator sh-hitachi-hms or sh
7012 Z8000 simulator z8k-zilog-none or z8ksim
7013 IDT MIPS board over serial line mips-idt-ecoff
7015 Cross-debugging to GO32 targets is supported. It requires a custom
7016 version of the i386-stub.c module which is integrated with the
7017 GO32 memory extender.
7019 * New remote protocols
7021 MIPS remote debugging protocol.
7023 * New source languages supported
7025 This version includes preliminary support for Chill, a Pascal like language
7026 used by telecommunications companies. Chill support is also being integrated
7027 into the GNU compiler, but we don't know when it will be publically available.
7030 *** Changes in GDB-4.8:
7032 * HP Precision Architecture supported
7034 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7035 version of this support was available as a set of patches from the
7036 University of Utah. GDB does not support debugging of programs
7037 compiled with the HP compiler, because HP will not document their file
7038 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7039 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7041 Many problems in the preliminary version have been fixed.
7043 * Faster and better demangling
7045 We have improved template demangling and fixed numerous bugs in the GNU style
7046 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7047 character types (wchar_t) are now supported. Demangling of each symbol is now
7048 only done once, and is cached when the symbol table for a file is read in.
7049 This results in a small increase in memory usage for C programs, a moderate
7050 increase in memory usage for C++ programs, and a fantastic speedup in
7053 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7054 from the specifications in the Annotated Reference Manual, which AT&T's
7055 compiler does not actually implement.
7057 * G++ multiple inheritance compiler problem
7059 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7060 inheritance lattices was reworked to properly discover ambiguities. We
7061 recently found an example which causes this new algorithm to fail in a
7062 very subtle way, producing bad debug information for those classes.
7063 The file 'gcc.patch' (in this directory) can be applied to gcc to
7064 circumvent the problem. A future GCC release will contain a complete
7067 The previous G++ debug info problem (mentioned below for the gdb-4.7
7068 release) is fixed in gcc version 2.3.2.
7070 * Improved configure script
7072 The `configure' script will now attempt to guess your system type if
7073 you don't supply a host system type. The old scheme of supplying a
7074 host system triplet is preferable over using this. All the magic is
7075 done in the new `config.guess' script. Examine it for details.
7077 We have also brought our configure script much more in line with the FSF's
7078 version. It now supports the --with-xxx options. In particular,
7079 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7080 The resulting GDB will not be able to read arbitrary object file formats --
7081 only the format ``expected'' to be used on the configured target system.
7082 We hope to make this the default in a future release.
7084 * Documentation improvements
7086 There's new internal documentation on how to modify GDB, and how to
7087 produce clean changes to the code. We implore people to read it
7088 before submitting changes.
7090 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7091 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7092 `info' files are also provided. To build `info' files from scratch,
7093 you will need the latest `makeinfo' release, which will be available in
7094 a future texinfo-X.Y release.
7096 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7097 We're not sure exactly which versions have this problem, but it has
7098 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7099 or better. If that isn't possible, there is a patch in
7100 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7101 around this problem.
7105 GDB now supports array constants that can be used in expressions typed in by
7106 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7107 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7110 The new directory `gdb/sparclite' contains a program that demonstrates
7111 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7113 * New native hosts supported
7115 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7116 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7118 * New targets supported
7120 AMD 29k family via UDI a29k-amd-udi or udi29k
7122 * New file formats supported
7124 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7125 HPUX core files, and SCO 3.2v2 core files.
7129 Attaching to processes now works again; thanks for the many bug reports.
7131 We have also stomped on a bunch of core dumps caused by
7132 printf_filtered("%s") problems.
7134 We eliminated a copyright problem on the rpc and ptrace header files
7135 for VxWorks, which was discovered at the last minute during the 4.7
7136 release. You should now be able to build a VxWorks GDB.
7138 You can now interrupt gdb while an attached process is running. This
7139 will cause the attached process to stop, and give control back to GDB.
7141 We fixed problems caused by using too many file descriptors
7142 for reading symbols from object files and libraries. This was
7143 especially a problem for programs that used many (~100) shared
7146 The `step' command now only enters a subroutine if there is line number
7147 information for the subroutine. Otherwise it acts like the `next'
7148 command. Previously, `step' would enter subroutines if there was
7149 any debugging information about the routine. This avoids problems
7150 when using `cc -g1' on MIPS machines.
7152 * Internal improvements
7154 GDB's internal interfaces have been improved to make it easier to support
7155 debugging of multiple languages in the future.
7157 GDB now uses a common structure for symbol information internally.
7158 Minimal symbols (derived from linkage symbols in object files), partial
7159 symbols (from a quick scan of debug information), and full symbols
7160 contain a common subset of information, making it easier to write
7161 shared code that handles any of them.
7163 * New command line options
7165 We now accept --silent as an alias for --quiet.
7169 The memory-mapped-malloc library is now licensed under the GNU Library
7170 General Public License.
7172 *** Changes in GDB-4.7:
7174 * Host/native/target split
7176 GDB has had some major internal surgery to untangle the support for
7177 hosts and remote targets. Now, when you configure GDB for a remote
7178 target, it will no longer load in all of the support for debugging
7179 local programs on the host. When fully completed and tested, this will
7180 ensure that arbitrary host/target combinations are possible.
7182 The primary conceptual shift is to separate the non-portable code in
7183 GDB into three categories. Host specific code is required any time GDB
7184 is compiled on that host, regardless of the target. Target specific
7185 code relates to the peculiarities of the target, but can be compiled on
7186 any host. Native specific code is everything else: it can only be
7187 built when the host and target are the same system. Child process
7188 handling and core file support are two common `native' examples.
7190 GDB's use of /proc for controlling Unix child processes is now cleaner.
7191 It has been split out into a single module under the `target_ops' vector,
7192 plus two native-dependent functions for each system that uses /proc.
7194 * New hosts supported
7196 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7197 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7198 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7200 * New targets supported
7202 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7203 68030 and CPU32 m68030-*-*, m68332-*-*
7205 * New native hosts supported
7207 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7208 (386bsd is not well tested yet)
7209 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7211 * New file formats supported
7213 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7214 supports reading of `a.out.adobe' object files, which are an a.out
7215 format extended with minimal information about multiple sections.
7219 `show copying' is the same as the old `info copying'.
7220 `show warranty' is the same as `info warrantee'.
7221 These were renamed for consistency. The old commands continue to work.
7223 `info handle' is a new alias for `info signals'.
7225 You can now define pre-command hooks, which attach arbitrary command
7226 scripts to any command. The commands in the hook will be executed
7227 prior to the user's command. You can also create a hook which will be
7228 executed whenever the program stops. See gdb.texinfo.
7232 We now deal with Cfront style name mangling, and can even extract type
7233 info from mangled symbols. GDB can automatically figure out which
7234 symbol mangling style your C++ compiler uses.
7236 Calling of methods and virtual functions has been improved as well.
7240 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7241 fixed. This was due to mishandling of the extra N_SO stabs output
7244 We also finally got Ultrix 4.2 running in house, and fixed core file
7245 support, with help from a dozen people on the net.
7247 John M. Farrell discovered that the reason that single-stepping was so
7248 slow on all of the Mips based platforms (primarily SGI and DEC) was
7249 that we were trying to demangle and lookup a symbol used for internal
7250 purposes on every instruction that was being stepped through. Changing
7251 the name of that symbol so that it couldn't be mistaken for a C++
7252 mangled symbol sped things up a great deal.
7254 Rich Pixley sped up symbol lookups in general by getting much smarter
7255 about when C++ symbol mangling is necessary. This should make symbol
7256 completion (TAB on the command line) much faster. It's not as fast as
7257 we'd like, but it's significantly faster than gdb-4.6.
7261 A new user controllable variable 'call_scratch_address' can
7262 specify the location of a scratch area to be used when GDB
7263 calls a function in the target. This is necessary because the
7264 usual method of putting the scratch area on the stack does not work
7265 in systems that have separate instruction and data spaces.
7267 We integrated changes to support the 29k UDI (Universal Debugger
7268 Interface), but discovered at the last minute that we didn't have all
7269 of the appropriate copyright paperwork. We are working with AMD to
7270 resolve this, and hope to have it available soon.
7274 We have sped up the remote serial line protocol, especially for targets
7275 with lots of registers. It now supports a new `expedited status' ('T')
7276 message which can be used in place of the existing 'S' status message.
7277 This allows the remote stub to send only the registers that GDB
7278 needs to make a quick decision about single-stepping or conditional
7279 breakpoints, eliminating the need to fetch the entire register set for
7280 each instruction being stepped through.
7282 The GDB remote serial protocol now implements a write-through cache for
7283 registers, only re-reading the registers if the target has run.
7285 There is also a new remote serial stub for SPARC processors. You can
7286 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7287 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7288 processor with a serial port.
7292 Configure.in files have become much easier to read and modify. A new
7293 `table driven' format makes it more obvious what configurations are
7294 supported, and what files each one uses.
7298 There is a new opcodes library which will eventually contain all of the
7299 disassembly routines and opcode tables. At present, it only contains
7300 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7301 disassembler (binutils/objdump) to share these routines.
7303 The libiberty library is now copylefted under the GNU Library General
7304 Public License. This allows more liberal use, and was done so libg++
7305 can use it. This makes no difference to GDB, since the Library License
7306 grants all the rights from the General Public License.
7310 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7311 reference to the stabs symbol info used by the debugger. It is (as far
7312 as we know) the only published document on this fascinating topic. We
7313 encourage you to read it, compare it to the stabs information on your
7314 system, and send improvements on the document in general (to
7315 bug-gdb@prep.ai.mit.edu).
7317 And, of course, many bugs have been fixed.
7320 *** Changes in GDB-4.6:
7322 * Better support for C++ function names
7324 GDB now accepts as input the "demangled form" of C++ overloaded function
7325 names and member function names, and can do command completion on such names
7326 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7327 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7328 Make use of command completion, it is your friend.
7330 GDB also now accepts a variety of C++ mangled symbol formats. They are
7331 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7332 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7333 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7334 for the list of formats.
7336 * G++ symbol mangling problem
7338 Recent versions of gcc have a bug in how they emit debugging information for
7339 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7340 directory) can be applied to gcc to fix the problem. Alternatively, if you
7341 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7342 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7343 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7346 * New 'maintenance' command
7348 All of the commands related to hacking GDB internals have been moved out of
7349 the main command set, and now live behind the 'maintenance' command. This
7350 can also be abbreviated as 'mt'. The following changes were made:
7352 dump-me -> maintenance dump-me
7353 info all-breakpoints -> maintenance info breakpoints
7354 printmsyms -> maintenance print msyms
7355 printobjfiles -> maintenance print objfiles
7356 printpsyms -> maintenance print psymbols
7357 printsyms -> maintenance print symbols
7359 The following commands are new:
7361 maintenance demangle Call internal GDB demangler routine to
7362 demangle a C++ link name and prints the result.
7363 maintenance print type Print a type chain for a given symbol
7365 * Change to .gdbinit file processing
7367 We now read the $HOME/.gdbinit file before processing the argv arguments
7368 (e.g. reading symbol files or core files). This allows global parameters to
7369 be set, which will apply during the symbol reading. The ./.gdbinit is still
7370 read after argv processing.
7372 * New hosts supported
7374 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7376 GNU/Linux support i386-unknown-linux or linux
7378 We are also including code to support the HP/PA running BSD and HPUX. This
7379 is almost guaranteed not to work, as we didn't have time to test or build it
7380 for this release. We are including it so that the more adventurous (or
7381 masochistic) of you can play with it. We also had major problems with the
7382 fact that the compiler that we got from HP doesn't support the -g option.
7385 * New targets supported
7387 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7389 * More smarts about finding #include files
7391 GDB now remembers the compilation directory for all include files, and for
7392 all files from which C is generated (like yacc and lex sources). This
7393 greatly improves GDB's ability to find yacc/lex sources, and include files,
7394 especially if you are debugging your program from a directory different from
7395 the one that contains your sources.
7397 We also fixed a bug which caused difficulty with listing and setting
7398 breakpoints in include files which contain C code. (In the past, you had to
7399 try twice in order to list an include file that you hadn't looked at before.)
7401 * Interesting infernals change
7403 GDB now deals with arbitrary numbers of sections, where the symbols for each
7404 section must be relocated relative to that section's landing place in the
7405 target's address space. This work was needed to support ELF with embedded
7406 stabs used by Solaris-2.0.
7408 * Bug fixes (of course!)
7410 There have been loads of fixes for the following things:
7411 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7412 i960, stabs, DOS(GO32), procfs, etc...
7414 See the ChangeLog for details.
7416 *** Changes in GDB-4.5:
7418 * New machines supported (host and target)
7420 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7422 SGI Irix-4.x mips-sgi-irix4 or iris4
7424 * New malloc package
7426 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7427 Mmalloc is capable of handling multiple heaps of memory. It is also
7428 capable of saving a heap to a file, and then mapping it back in later.
7429 This can be used to greatly speedup the startup of GDB by using a
7430 pre-parsed symbol table which lives in a mmalloc managed heap. For
7431 more details, please read mmalloc/mmalloc.texi.
7435 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7436 'help info proc' for details.
7438 * MIPS ecoff symbol table format
7440 The code that reads MIPS symbol table format is now supported on all hosts.
7441 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7444 * File name changes for MS-DOS
7446 Many files in the config directories have been renamed to make it easier to
7447 support GDB on MS-DOSe systems (which have very restrictive file name
7448 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7449 environment) is close to working but has some remaining problems. Note
7450 that debugging of DOS programs is not supported, due to limitations
7451 in the ``operating system'', but it can be used to host cross-debugging.
7453 * Cross byte order fixes
7455 Many fixes have been made to support cross debugging of Sparc and MIPS
7456 targets from hosts whose byte order differs.
7458 * New -mapped and -readnow options
7460 If memory-mapped files are available on your system through the 'mmap'
7461 system call, you can use the -mapped option on the `file' or
7462 `symbol-file' commands to cause GDB to write the symbols from your
7463 program into a reusable file. If the program you are debugging is
7464 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7465 Future GDB debugging sessions will notice the presence of this file,
7466 and will quickly map in symbol information from it, rather than reading
7467 the symbol table from the executable program. Using the '-mapped'
7468 option in a GDB `file' or `symbol-file' command has the same effect as
7469 starting GDB with the '-mapped' command-line option.
7471 You can cause GDB to read the entire symbol table immediately by using
7472 the '-readnow' option with any of the commands that load symbol table
7473 information (or on the GDB command line). This makes the command
7474 slower, but makes future operations faster.
7476 The -mapped and -readnow options are typically combined in order to
7477 build a `fred.syms' file that contains complete symbol information.
7478 A simple GDB invocation to do nothing but build a `.syms' file for future
7481 gdb -batch -nx -mapped -readnow programname
7483 The `.syms' file is specific to the host machine on which GDB is run.
7484 It holds an exact image of GDB's internal symbol table. It cannot be
7485 shared across multiple host platforms.
7487 * longjmp() handling
7489 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7490 siglongjmp() without losing control. This feature has not yet been ported to
7491 all systems. It currently works on many 386 platforms, all MIPS-based
7492 platforms (SGI, DECstation, etc), and Sun3/4.
7496 Preliminary work has been put in to support the new Solaris OS from Sun. At
7497 this time, it can control and debug processes, but it is not capable of
7502 As always, many many bug fixes. The major areas were with g++, and mipsread.
7503 People using the MIPS-based platforms should experience fewer mysterious
7504 crashes and trashed symbol tables.
7506 *** Changes in GDB-4.4:
7508 * New machines supported (host and target)
7510 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7512 BSD Reno on Vax vax-dec-bsd
7513 Ultrix on Vax vax-dec-ultrix
7515 * New machines supported (target)
7517 AMD 29000 embedded, using EBMON a29k-none-none
7521 GDB continues to improve its handling of C++. `References' work better.
7522 The demangler has also been improved, and now deals with symbols mangled as
7523 per the Annotated C++ Reference Guide.
7525 GDB also now handles `stabs' symbol information embedded in MIPS
7526 `ecoff' symbol tables. Since the ecoff format was not easily
7527 extensible to handle new languages such as C++, this appeared to be a
7528 good way to put C++ debugging info into MIPS binaries. This option
7529 will be supported in the GNU C compiler, version 2, when it is
7532 * New features for SVR4
7534 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7535 shared libraries. Debugging dynamically linked programs should present
7536 only minor differences from debugging statically linked programs.
7538 The `info proc' command will print out information about any process
7539 on an SVR4 system (including the one you are debugging). At the moment,
7540 it prints the address mappings of the process.
7542 If you bring up GDB on another SVR4 system, please send mail to
7543 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7545 * Better dynamic linking support in SunOS
7547 Reading symbols from shared libraries which contain debugging symbols
7548 now works properly. However, there remain issues such as automatic
7549 skipping of `transfer vector' code during function calls, which
7550 make it harder to debug code in a shared library, than to debug the
7551 same code linked statically.
7555 GDB is now using the latest `getopt' routines from the FSF. This
7556 version accepts the -- prefix for options with long names. GDB will
7557 continue to accept the old forms (-option and +option) as well.
7558 Various single letter abbreviations for options have been explicity
7559 added to the option table so that they won't get overshadowed in the
7560 future by other options that begin with the same letter.
7564 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7565 Many assorted bugs have been handled. Many more remain to be handled.
7566 See the various ChangeLog files (primarily in gdb and bfd) for details.
7569 *** Changes in GDB-4.3:
7571 * New machines supported (host and target)
7573 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7574 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7575 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7577 * Almost SCO Unix support
7579 We had hoped to support:
7580 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7581 (except for core file support), but we discovered very late in the release
7582 that it has problems with process groups that render gdb unusable. Sorry
7583 about that. I encourage people to fix it and post the fixes.
7585 * Preliminary ELF and DWARF support
7587 GDB can read ELF object files on System V Release 4, and can handle
7588 debugging records for C, in DWARF format, in ELF files. This support
7589 is preliminary. If you bring up GDB on another SVR4 system, please
7590 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7595 GDB now uses the latest `readline' library. One user-visible change
7596 is that two tabs will list possible command completions, which previously
7597 required typing M-? (meta-question mark, or ESC ?).
7601 The `stepi' bug that many of you noticed has been squashed.
7602 Many bugs in C++ have been handled. Many more remain to be handled.
7603 See the various ChangeLog files (primarily in gdb and bfd) for details.
7605 * State of the MIPS world (in case you wondered):
7607 GDB can understand the symbol tables emitted by the compilers
7608 supplied by most vendors of MIPS-based machines, including DEC. These
7609 symbol tables are in a format that essentially nobody else uses.
7611 Some versions of gcc come with an assembler post-processor called
7612 mips-tfile. This program is required if you want to do source-level
7613 debugging of gcc-compiled programs. I believe FSF does not ship
7614 mips-tfile with gcc version 1, but it will eventually come with gcc
7617 Debugging of g++ output remains a problem. g++ version 1.xx does not
7618 really support it at all. (If you're lucky, you should be able to get
7619 line numbers and stack traces to work, but no parameters or local
7620 variables.) With some work it should be possible to improve the
7623 When gcc version 2 is released, you will have somewhat better luck.
7624 However, even then you will get confusing results for inheritance and
7627 We will eventually provide full debugging of g++ output on
7628 DECstations. This will probably involve some kind of stabs-in-ecoff
7629 encapulation, but the details have not been worked out yet.
7632 *** Changes in GDB-4.2:
7634 * Improved configuration
7636 Only one copy of `configure' exists now, and it is not self-modifying.
7637 Porting BFD is simpler.
7641 The `step' and `next' commands now only stop at the first instruction
7642 of a source line. This prevents the multiple stops that used to occur
7643 in switch statements, for-loops, etc. `Step' continues to stop if a
7644 function that has debugging information is called within the line.
7648 Lots of small bugs fixed. More remain.
7650 * New host supported (not target)
7652 Intel 386 PC clone running Mach i386-none-mach
7655 *** Changes in GDB-4.1:
7657 * Multiple source language support
7659 GDB now has internal scaffolding to handle several source languages.
7660 It determines the type of each source file from its filename extension,
7661 and will switch expression parsing and number formatting to match the
7662 language of the function in the currently selected stack frame.
7663 You can also specifically set the language to be used, with
7664 `set language c' or `set language modula-2'.
7668 GDB now has preliminary support for the GNU Modula-2 compiler,
7669 currently under development at the State University of New York at
7670 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7671 continue through the fall of 1991 and into 1992.
7673 Other Modula-2 compilers are currently not supported, and attempting to
7674 debug programs compiled with them will likely result in an error as the
7675 symbol table is read. Feel free to work on it, though!
7677 There are hooks in GDB for strict type checking and range checking,
7678 in the `Modula-2 philosophy', but they do not currently work.
7682 GDB can now write to executable and core files (e.g. patch
7683 a variable's value). You must turn this switch on, specify
7684 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7685 by assigning a new value to a variable. Modifications take
7688 * Automatic SunOS shared library reading
7690 When you run your program, GDB automatically determines where its
7691 shared libraries (if any) have been loaded, and reads their symbols.
7692 The `share' command is no longer needed. This also works when
7693 examining core files.
7697 You can specify the number of lines that the `list' command shows.
7700 * New machines supported (host and target)
7702 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7703 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7704 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7706 * New hosts supported (not targets)
7708 IBM RT/PC: romp-ibm-aix or rtpc
7710 * New targets supported (not hosts)
7712 AMD 29000 embedded with COFF a29k-none-coff
7713 AMD 29000 embedded with a.out a29k-none-aout
7714 Ultracomputer remote kernel debug a29k-nyu-kern
7716 * New remote interfaces
7722 *** Changes in GDB-4.0:
7726 Wide output is wrapped at good places to make the output more readable.
7728 Gdb now supports cross-debugging from a host machine of one type to a
7729 target machine of another type. Communication with the target system
7730 is over serial lines. The ``target'' command handles connecting to the
7731 remote system; the ``load'' command will download a program into the
7732 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7733 also supports debugging of realtime processes running under VxWorks,
7734 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7735 stub on the target system.
7737 New CPUs supported include the AMD 29000 and Intel 960.
7739 GDB now reads object files and symbol tables via a ``binary file''
7740 library, which allows a single copy of GDB to debug programs of multiple
7741 object file types such as a.out and coff.
7743 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7744 refcard.dvi and refcard.ps are available to format it).
7747 * Control-Variable user interface simplified
7749 All variables that control the operation of the debugger can be set
7750 by the ``set'' command, and displayed by the ``show'' command.
7752 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7753 ``Show prompt'' produces the response:
7754 Gdb's prompt is new-gdb=>.
7756 What follows are the NEW set commands. The command ``help set'' will
7757 print a complete list of old and new set commands. ``help set FOO''
7758 will give a longer description of the variable FOO. ``show'' will show
7759 all of the variable descriptions and their current settings.
7761 confirm on/off: Enables warning questions for operations that are
7762 hard to recover from, e.g. rerunning the program while
7763 it is already running. Default is ON.
7765 editing on/off: Enables EMACS style command line editing
7766 of input. Previous lines can be recalled with
7767 control-P, the current line can be edited with control-B,
7768 you can search for commands with control-R, etc.
7771 history filename NAME: NAME is where the gdb command history
7772 will be stored. The default is .gdb_history,
7773 or the value of the environment variable
7776 history size N: The size, in commands, of the command history. The
7777 default is 256, or the value of the environment variable
7780 history save on/off: If this value is set to ON, the history file will
7781 be saved after exiting gdb. If set to OFF, the
7782 file will not be saved. The default is OFF.
7784 history expansion on/off: If this value is set to ON, then csh-like
7785 history expansion will be performed on
7786 command line input. The default is OFF.
7788 radix N: Sets the default radix for input and output. It can be set
7789 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7790 in the current radix, so "set radix 10" is always a no-op.
7792 height N: This integer value is the number of lines on a page. Default
7793 is 24, the current `stty rows'' setting, or the ``li#''
7794 setting from the termcap entry matching the environment
7797 width N: This integer value is the number of characters on a line.
7798 Default is 80, the current `stty cols'' setting, or the ``co#''
7799 setting from the termcap entry matching the environment
7802 Note: ``set screensize'' is obsolete. Use ``set height'' and
7803 ``set width'' instead.
7805 print address on/off: Print memory addresses in various command displays,
7806 such as stack traces and structure values. Gdb looks
7807 more ``symbolic'' if you turn this off; it looks more
7808 ``machine level'' with it on. Default is ON.
7810 print array on/off: Prettyprint arrays. New convenient format! Default
7813 print demangle on/off: Print C++ symbols in "source" form if on,
7816 print asm-demangle on/off: Same, for assembler level printouts
7819 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7822 * Support for Epoch Environment.
7824 The epoch environment is a version of Emacs v18 with windowing. One
7825 new command, ``inspect'', is identical to ``print'', except that if you
7826 are running in the epoch environment, the value is printed in its own
7830 * Support for Shared Libraries
7832 GDB can now debug programs and core files that use SunOS shared libraries.
7833 Symbols from a shared library cannot be referenced
7834 before the shared library has been linked with the program (this
7835 happens after you type ``run'' and before the function main() is entered).
7836 At any time after this linking (including when examining core files
7837 from dynamically linked programs), gdb reads the symbols from each
7838 shared library when you type the ``sharedlibrary'' command.
7839 It can be abbreviated ``share''.
7841 sharedlibrary REGEXP: Load shared object library symbols for files
7842 matching a unix regular expression. No argument
7843 indicates to load symbols for all shared libraries.
7845 info sharedlibrary: Status of loaded shared libraries.
7850 A watchpoint stops execution of a program whenever the value of an
7851 expression changes. Checking for this slows down execution
7852 tremendously whenever you are in the scope of the expression, but is
7853 quite useful for catching tough ``bit-spreader'' or pointer misuse
7854 problems. Some machines such as the 386 have hardware for doing this
7855 more quickly, and future versions of gdb will use this hardware.
7857 watch EXP: Set a watchpoint (breakpoint) for an expression.
7859 info watchpoints: Information about your watchpoints.
7861 delete N: Deletes watchpoint number N (same as breakpoints).
7862 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7863 enable N: Re-enables watchpoint number N (same as breakpoints).
7866 * C++ multiple inheritance
7868 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7871 * C++ exception handling
7873 Gdb now supports limited C++ exception handling. Besides the existing
7874 ability to breakpoint on an exception handler, gdb can breakpoint on
7875 the raising of an exception (before the stack is peeled back to the
7878 catch FOO: If there is a FOO exception handler in the dynamic scope,
7879 set a breakpoint to catch exceptions which may be raised there.
7880 Multiple exceptions (``catch foo bar baz'') may be caught.
7882 info catch: Lists all exceptions which may be caught in the
7883 current stack frame.
7886 * Minor command changes
7888 The command ``call func (arg, arg, ...)'' now acts like the print
7889 command, except it does not print or save a value if the function's result
7890 is void. This is similar to dbx usage.
7892 The ``up'' and ``down'' commands now always print the frame they end up
7893 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7894 frames without printing.
7896 * New directory command
7898 'dir' now adds directories to the FRONT of the source search path.
7899 The path starts off empty. Source files that contain debug information
7900 about the directory in which they were compiled can be found even
7901 with an empty path; Sun CC and GCC include this information. If GDB can't
7902 find your source file in the current directory, type "dir .".
7904 * Configuring GDB for compilation
7906 For normal use, type ``./configure host''. See README or gdb.texinfo
7909 GDB now handles cross debugging. If you are remotely debugging between
7910 two different machines, type ``./configure host -target=targ''.
7911 Host is the machine where GDB will run; targ is the machine
7912 where the program that you are debugging will run.