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.
125 * 'thread-exited' event is now available in the annotations interface.
127 * New built-in convenience variables $_gdb_major and $_gdb_minor
128 provide the GDB version. They are handy for conditionally using
129 features available only in or since specific GDB versions, in
130 scripts that should work error-free with many different versions,
131 such as in system-wide init files.
133 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
134 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
135 of the GDB settings and the GDB maintenance settings. They are handy
136 for changing the logic of user defined commands depending on the
137 current GDB settings.
139 * GDB now supports Thread Local Storage (TLS) variables on several
140 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
141 architectures require kernel changes. TLS is not yet supported for
142 amd64 and i386 process core dumps.
144 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
145 addresses that required unmasking are shown in the backtrace with the
148 * Two new convenience functions $_cimag and $_creal that extract the
149 imaginary and real parts respectively from complex numbers.
151 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
152 provide the exitcode or exit status of the shell commands launched by
153 GDB commands such as "shell", "pipe" and "make".
155 * The command define-prefix can now define user defined prefix commands.
156 User defined commands can now be defined using these user defined prefix
159 * Command names can now use the . character.
161 * The RX port now supports XML target descriptions.
163 * GDB now shows the Ada task names at more places, e.g. in task switching
166 * GDB can now be compiled with Python 3 on Windows.
168 * New convenience variable $_ada_exception holds the address of the
169 Ada exception being thrown. This is set by Ada-related catchpoints.
171 * GDB can now place breakpoints on nested functions and subroutines in
172 Fortran code. The '::' operator can be used between parent and
173 child scopes when placing breakpoints, for example:
175 (gdb) break outer_function::inner_function
177 The 'outer_function::' prefix is only needed if 'inner_function' is
178 not visible in the current scope.
180 * In addition to the system-wide gdbinit file, if configured with
181 --with-system-gdbinit-dir, GDB will now also load files in that directory
182 as system gdbinit files, unless the -nx or -n flag is provided. Files
183 with extensions .gdb, .py and .scm are supported as long as GDB was
184 compiled with support for that language.
186 * GDB now supports multithreaded symbol loading for higher performance.
187 This feature is still in testing, so it is disabled by default. You
188 can turn it on using 'maint set worker-threads unlimited'.
190 * Multi-target debugging support
192 GDB now supports debugging multiple target connections
193 simultaneously. For example, you can now have each inferior
194 connected to different remote servers running in different machines,
195 or have one inferior debugging a local native process, an inferior
196 debugging a core dump, etc.
198 This support is experimental and comes with some limitations -- you
199 can only resume multiple targets simultaneously if all targets
200 support non-stop mode, and all remote stubs or servers must support
201 the same set of remote protocol features exactly. See also "info
202 connections" and "add-inferior -no-connection" below, and "maint set
203 target-non-stop" in the user manual.
207 ** The gdb.Value type has a new method 'format_string' which returns a
208 string representing the value. The formatting is controlled by the
209 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
210 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
211 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
213 ** gdb.Type has a new property 'objfile' which returns the objfile the
216 ** The frame information printed by the python frame filtering code
217 is now consistent with what the 'backtrace' command prints when
218 there are no filters, or when the 'backtrace' '-no-filters' option
221 ** The new function gdb.lookup_static_symbol can be used to look up
222 symbols with static linkage.
224 ** The new function gdb.lookup_static_symbols can be used to look up
225 all static symbols with static linkage.
227 ** gdb.Objfile has new methods 'lookup_global_symbol' and
228 'lookup_static_symbol' to lookup a symbol from this objfile only.
230 ** gdb.Block now supports the dictionary syntax for accessing symbols in
231 this block (e.g. block['local_variable']).
235 | [COMMAND] | SHELL_COMMAND
236 | -d DELIM COMMAND DELIM SHELL_COMMAND
237 pipe [COMMAND] | SHELL_COMMAND
238 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
239 Executes COMMAND and sends its output to SHELL_COMMAND.
240 With no COMMAND, repeat the last executed command
241 and send its output to SHELL_COMMAND.
243 define-prefix COMMAND
244 Define or mark a command as a user-defined prefix command.
246 with SETTING [VALUE] [-- COMMAND]
247 w SETTING [VALUE] [-- COMMAND]
248 Temporarily set SETTING, run COMMAND, and restore SETTING.
249 Usage: with SETTING -- COMMAND
250 With no COMMAND, repeats the last executed command.
251 SETTING is any GDB setting you can change with the "set"
252 subcommands. For example, 'with language c -- print someobj'
253 temporarily switches to the C language in order to print someobj.
254 Settings can be combined: 'w lang c -- w print elements unlimited --
255 usercmd' switches to the C language and runs usercmd with no limit
256 of array elements to print.
258 maint with SETTING [VALUE] [-- COMMAND]
259 Like "with", but works with "maintenance set" settings.
261 set may-call-functions [on|off]
262 show may-call-functions
263 This controls whether GDB will attempt to call functions in
264 the program, such as with expressions in the print command. It
265 defaults to on. Calling functions in the program being debugged
266 can have undesired side effects. It is now possible to forbid
267 such function calls. If function calls are forbidden, GDB will throw
268 an error when a command (such as print expression) calls a function
271 set print finish [on|off]
273 This controls whether the `finish' command will display the value
274 that is returned by the current function. When `off', the value is
275 still entered into the value history, but it is not printed. The
280 Allows deeply nested structures to be simplified when printing by
281 replacing deeply nested parts (beyond the max-depth) with ellipses.
282 The default max-depth is 20, but this can be set to unlimited to get
283 the old behavior back.
285 set print raw-values [on|off]
286 show print raw-values
287 By default, GDB applies the enabled pretty printers when printing a
288 value. This allows to ignore the enabled pretty printers for a series
289 of commands. The default is 'off'.
291 set logging debugredirect [on|off]
292 By default, GDB debug output will go to both the terminal and the logfile.
293 Set if you want debug output to go only to the log file.
295 set style title foreground COLOR
296 set style title background COLOR
297 set style title intensity VALUE
298 Control the styling of titles.
300 set style highlight foreground COLOR
301 set style highlight background COLOR
302 set style highlight intensity VALUE
303 Control the styling of highlightings.
305 maint set worker-threads
306 maint show worker-threads
307 Control the number of worker threads that can be used by GDB. The
308 default is 0. "unlimited" lets GDB choose a number that is
309 reasonable. Currently worker threads are only used when demangling
310 the names of linker symbols.
312 set style tui-border foreground COLOR
313 set style tui-border background COLOR
314 Control the styling of TUI borders.
316 set style tui-active-border foreground COLOR
317 set style tui-active-border background COLOR
318 Control the styling of the active TUI border.
320 maint set test-settings KIND
321 maint show test-settings KIND
322 A set of commands used by the testsuite for exercising the settings
325 maint set tui-resize-message [on|off]
326 maint show tui-resize-message
327 Control whether GDB prints a message each time the terminal is
328 resized when in TUI mode. This is primarily useful for testing the
331 set print frame-info [short-location|location|location-and-address
332 |source-and-location|source-line|auto]
333 show print frame-info
334 This controls what frame information is printed by the commands printing
335 a frame. This setting will e.g. influence the behaviour of 'backtrace',
336 'frame', 'stepi'. The python frame filtering also respect this setting.
337 The 'backtrace' '-frame-info' option can override this global setting.
339 set tui compact-source
340 show tui compact-source
342 Enable the "compact" display mode for the TUI source window. The
343 compact display uses only as much space as is needed for the line
344 numbers in the current file, and only a single space to separate the
345 line numbers from the source.
347 info modules [-q] [REGEXP]
348 Return a list of Fortran modules matching REGEXP, or all modules if
351 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
352 Return a list of functions within all modules, grouped by module.
353 The list of functions can be restricted with the optional regular
354 expressions. MODULE_REGEXP matches against the module name,
355 TYPE_REGEXP matches against the function type signature, and REGEXP
356 matches against the function name.
358 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
359 Return a list of variables within all modules, grouped by module.
360 The list of variables can be restricted with the optional regular
361 expressions. MODULE_REGEXP matches against the module name,
362 TYPE_REGEXP matches against the variable type, and REGEXP matches
363 against the variable name.
365 set debug remote-packet-max-chars
366 show debug remote-packet-max-chars
367 Controls the number of characters to output in a remote packet when using
369 The default is 512 bytes.
372 Lists the target connections currently in use.
377 The "help" command uses the title style to enhance the
378 readibility of its output by styling the classes and
382 Similarly to "help", the "apropos" command also uses the
383 title style for the command names. "apropos" accepts now
384 a flag "-v" (verbose) to show the full documentation
385 of matching commands and to use the highlight style to mark
386 the documentation parts matching REGEXP.
390 The GDB printf and eval commands can now print C-style and Ada-style
391 string convenience variables without calling functions in the program.
392 This allows to do formatted printing of strings without having
393 a running inferior, or when debugging a core dump.
395 info sources [-dirname | -basename] [--] [REGEXP]
396 This command has now optional arguments to only print the files
397 whose names match REGEXP. The arguments -dirname and -basename
398 allow to restrict matching respectively to the dirname and basename
402 The "show style" and its subcommands are now styling
403 a style name in their output using its own style, to help
404 the user visualize the different styles.
406 set print frame-arguments
407 The new value 'presence' indicates to only indicate the presence of
408 arguments using ..., instead of printing argument names and values.
410 set print raw-frame-arguments
411 show print raw-frame-arguments
413 These commands replace the similarly-named "set/show print raw
414 frame-arguments" commands (now with a dash instead of a space). The
415 old commands are now deprecated and may be removed in a future
418 add-inferior [-no-connection]
419 The add-inferior command now supports a "-no-connection" flag that
420 makes the new inferior start with no target connection associated.
421 By default, the new inferior inherits the target connection of the
422 current inferior. See also "info connections".
425 This command's output now includes a new "Connection" column
426 indicating which target connection an inferior is bound to. See
427 "info connections" above.
429 maint test-options require-delimiter
430 maint test-options unknown-is-error
431 maint test-options unknown-is-operand
432 maint show test-options-completion-result
433 Commands used by the testsuite to validate the command options
436 focus, winheight, +, -, >, <
437 These commands are now case-sensitive.
439 * New command options, command completion
441 GDB now has a standard infrastructure to support dash-style command
442 options ('-OPT'). One benefit is that commands that use it can
443 easily support completion of command line arguments. Try "CMD
444 -[TAB]" or "help CMD" to find options supported by a command. Over
445 time, we intend to migrate most commands to this infrastructure. A
446 number of commands got support for new command options in this
449 ** The "print" and "compile print" commands now support a number of
450 options that allow overriding relevant global print settings as
451 set by "set print" subcommands:
455 -array-indexes [on|off]
456 -elements NUMBER|unlimited
461 -repeats NUMBER|unlimited
462 -static-members [on|off]
467 Note that because the "print"/"compile print" commands accept
468 arbitrary expressions which may look like options (including
469 abbreviations), if you specify any command option, then you must
470 use a double dash ("--") to mark the end of argument processing.
472 ** The "backtrace" command now supports a number of options that
473 allow overriding relevant global print settings as set by "set
474 backtrace" and "set print" subcommands:
476 -entry-values no|only|preferred|if-needed|both|compact|default
477 -frame-arguments all|scalars|none
478 -raw-frame-arguments [on|off]
479 -frame-info auto|source-line|location|source-and-location
480 |location-and-address|short-location
484 In addition, the full/no-filters/hide qualifiers are now also
485 exposed as command options too:
491 ** The "frame apply", "tfaas" and "faas" commands similarly now
492 support the following options:
497 ** The new "info sources" options -dirname and -basename options
498 are using the standard '-OPT' infrastructure.
500 All options above can also be abbreviated. The argument of boolean
501 (on/off) options can be 0/1 too, and also the argument is assumed
502 "on" if omitted. This allows writing compact command invocations,
505 (gdb) p -ra -p -o 0 -- *myptr
507 The above is equivalent to:
509 (gdb) print -raw-values -pretty -object off -- *myptr
511 ** The "info types" command now supports the '-q' flag to disable
512 printing of some header information in a similar fashion to "info
513 variables" and "info functions".
515 ** The "info variables", "info functions", and "whereis" commands
516 now take a '-n' flag that excludes non-debug symbols (symbols
517 from the symbol table, not from the debug info such as DWARF)
520 * Completion improvements
522 ** GDB can now complete the options of the "thread apply all" and
523 "taas" commands, and their "-ascending" option can now be
526 ** GDB can now complete the options of the "info threads", "info
527 functions", "info variables", "info locals", and "info args"
530 ** GDB can now complete the options of the "compile file" and
531 "compile code" commands. The "compile file" command now
532 completes on filenames.
534 ** GDB can now complete the backtrace command's
535 "full/no-filters/hide" qualifiers.
537 * In settings, you can now abbreviate "unlimited".
539 E.g., "set print elements u" is now equivalent to "set print
545 This lists all the possible completions for the rest of the line, if it
546 were to be given as a command itself. This is intended for use by MI
547 frontends in cases when separate CLI and MI channels cannot be used.
549 -catch-throw, -catch-rethrow, and -catch-catch
550 These can be used to catch C++ exceptions in a similar fashion to
551 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
553 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
554 These commands are the MI equivalent of the CLI commands 'info
555 functions', 'info types', and 'info variables' respectively.
557 -symbol-info-modules, this is the MI equivalent of the CLI 'info
560 -symbol-info-module-functions and -symbol-info-module-variables.
561 These commands are the MI equivalent of the CLI commands 'info
562 module functions' and 'info module variables'.
566 ** The default version of the MI interpreter is now 3 (-i=mi3).
568 ** The output of information about multi-location breakpoints (which is
569 syntactically incorrect in MI 2) has changed in MI 3. This affects
570 the following commands and events:
574 - =breakpoint-created
575 - =breakpoint-modified
577 The -fix-multi-location-breakpoint-output command can be used to enable
578 this behavior with previous MI versions.
580 ** Backtraces and frames include a new optional field addr_flags which is
581 given after the addr field. On AArch64 this contains PAC if the address
582 has been masked in the frame. On all other targets the field is not
587 The testsuite now creates the files gdb.cmd (containing the arguments
588 used to launch GDB) and gdb.in (containing all the commands sent to
589 GDB) in the output directory for each test script. Multiple invocations
590 are appended with .1, .2, .3 etc.
592 * Building GDB and GDBserver now requires GNU make >= 3.82.
594 Using another implementation of the make program or an earlier version of
595 GNU make to build GDB or GDBserver is not supported.
597 * Building GDB now requires GNU readline >= 7.0.
599 GDB now bundles GNU readline 8.0, but if you choose to use
600 --with-system-readline, only readline >= 7.0 can be used.
602 * The TUI SingleKey keymap is now named "SingleKey". This can be used
603 from .inputrc to bind keys in this keymap. This feature is only
604 available when gdb is built against GNU readline 8.0 or later.
606 * Removed targets and native configurations
608 GDB no longer supports debugging the Cell Broadband Engine. This includes
609 both debugging standalone Cell/B.E. SPU applications and integrated debugging
610 of Cell/B.E. applications that use both the PPU and SPU architectures.
616 * Removed targets and native configurations
618 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
621 *** Changes in GDB 8.3
623 * GDB and GDBserver now support access to additional registers on
624 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
627 * GDB now has experimental support for the compilation and injection of
628 C++ source code into the inferior. This beta release does not include
629 support for several language features, such as templates, constructors,
632 This feature requires GCC 7.1 or higher built with libcp1.so
635 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
636 can be passed using the '[ADDRESS]:PORT' notation, or the regular
637 'ADDRESS:PORT' method.
639 * DWARF index cache: GDB can now automatically save indices of DWARF
640 symbols on disk to speed up further loading of the same binaries.
642 * Ada task switching is now supported on aarch64-elf targets when
643 debugging a program using the Ravenscar Profile. For more information,
644 see the "Tasking Support when using the Ravenscar Profile" section
645 in the GDB user manual.
647 * GDB in batch mode now exits with status 1 if the last command to be
650 * The RISC-V target now supports target descriptions.
652 * System call catchpoints now support system call aliases on FreeBSD.
653 When the ABI of a system call changes in FreeBSD, this is
654 implemented by leaving a compatibility system call using the old ABI
655 at the existing number and allocating a new system call number for
656 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
657 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
658 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
659 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
660 so that a system call catchpoint for the 'kevent' system call will
661 catch invocations of both the 'kevent' and 'freebsd11_kevent'
662 binaries. This ensures that 'kevent' system calls are caught for
663 binaries using either the old or new ABIs.
665 * Terminal styling is now available for the CLI and the TUI. GNU
666 Source Highlight can additionally be used to provide styling of
667 source code snippets. See the "set style" commands, below, for more
670 * Removed support for old demangling styles arm, edg, gnu, hp and
675 set debug compile-cplus-types
676 show debug compile-cplus-types
677 Control the display of debug output about type conversion in the
678 C++ compile feature. Commands have no effect while compiling
683 Control whether debug output about files/functions skipping is
686 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
687 Apply a command to some frames.
688 FLAG arguments allow to control what output to produce and how to handle
689 errors raised when applying COMMAND to a frame.
692 Apply a command to all threads (ignoring errors and empty output).
693 Shortcut for 'thread apply all -s COMMAND'.
696 Apply a command to all frames (ignoring errors and empty output).
697 Shortcut for 'frame apply all -s COMMAND'.
700 Apply a command to all frames of all threads (ignoring errors and empty
702 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
704 maint set dwarf unwinders (on|off)
705 maint show dwarf unwinders
706 Control whether DWARF unwinders can be used.
709 Display a list of open files for a process.
713 Changes to the "frame", "select-frame", and "info frame" CLI commands.
714 These commands all now take a frame specification which
715 is either a frame level, or one of the keywords 'level', 'address',
716 'function', or 'view' followed by a parameter. Selecting a frame by
717 address, or viewing a frame outside the current backtrace now
718 requires the use of a keyword. Selecting a frame by level is
719 unchanged. The MI comment "-stack-select-frame" is unchanged.
721 target remote FILENAME
722 target extended-remote FILENAME
723 If FILENAME is a Unix domain socket, GDB will attempt to connect
724 to this socket instead of opening FILENAME as a character device.
726 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
727 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
728 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
729 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
730 These commands can now print only the searched entities
731 matching the provided regexp(s), giving a condition
732 on the entity names or entity types. The flag -q disables
733 printing headers or informations messages.
739 These commands now determine the syntax for the shown entities
740 according to the language chosen by `set language'. In particular,
741 `set language auto' means to automatically choose the language of
744 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
745 The 'thread apply' command accepts new FLAG arguments.
746 FLAG arguments allow to control what output to produce and how to handle
747 errors raised when applying COMMAND to a thread.
749 set tui tab-width NCHARS
750 show tui tab-width NCHARS
751 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
753 set style enabled [on|off]
755 Enable or disable terminal styling. Styling is enabled by default
756 on most hosts, but disabled by default when in batch mode.
758 set style sources [on|off]
760 Enable or disable source code styling. Source code styling is
761 enabled by default, but only takes effect if styling in general is
762 enabled, and if GDB was linked with GNU Source Highlight.
764 set style filename foreground COLOR
765 set style filename background COLOR
766 set style filename intensity VALUE
767 Control the styling of file names.
769 set style function foreground COLOR
770 set style function background COLOR
771 set style function intensity VALUE
772 Control the styling of function names.
774 set style variable foreground COLOR
775 set style variable background COLOR
776 set style variable intensity VALUE
777 Control the styling of variable names.
779 set style address foreground COLOR
780 set style address background COLOR
781 set style address intensity VALUE
782 Control the styling of addresses.
786 ** The '-data-disassemble' MI command now accepts an '-a' option to
787 disassemble the whole function surrounding the given program
788 counter value or function name. Support for this feature can be
789 verified by using the "-list-features" command, which should
790 contain "data-disassemble-a-option".
792 ** Command responses and notifications that include a frame now include
793 the frame's architecture in a new "arch" attribute.
795 * New native configurations
797 GNU/Linux/RISC-V riscv*-*-linux*
798 FreeBSD/riscv riscv*-*-freebsd*
802 GNU/Linux/RISC-V riscv*-*-linux*
804 CSKY GNU/LINUX csky*-*-linux
805 FreeBSD/riscv riscv*-*-freebsd*
807 GNU/Linux/OpenRISC or1k*-*-linux*
811 GDB no longer supports native debugging on versions of MS-Windows
816 ** GDB no longer supports Python versions less than 2.6.
818 ** The gdb.Inferior type has a new 'progspace' property, which is the program
819 space associated to that inferior.
821 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
822 of objfiles associated to that program space.
824 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
825 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
828 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
829 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
830 correct and did not work properly.
832 ** The gdb.Value type has a new constructor, which is used to construct a
833 gdb.Value from a Python buffer object and a gdb.Type.
839 Enable or disable the undefined behavior sanitizer. This is
840 disabled by default, but passing --enable-ubsan=yes or
841 --enable-ubsan=auto to configure will enable it. Enabling this can
842 cause a performance penalty. The undefined behavior sanitizer was
843 first introduced in GCC 4.9.
845 *** Changes in GDB 8.2
847 * The 'set disassembler-options' command now supports specifying options
850 * The 'symbol-file' command now accepts an '-o' option to add a relative
851 offset to all sections.
853 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
854 a relative offset to all sections, but it allows to override the load
855 address of individual sections using '-s'.
857 * The 'add-symbol-file' command no longer requires the second argument
858 (address of the text section).
860 * The endianness used with the 'set endian auto' mode in the absence of
861 an executable selected for debugging is now the last endianness chosen
862 either by one of the 'set endian big' and 'set endian little' commands
863 or by inferring from the last executable used, rather than the startup
866 * The pager now allows a "c" response, meaning to disable the pager
867 for the rest of the current command.
869 * The commands 'info variables/functions/types' now show the source line
870 numbers of symbol definitions when available.
872 * 'info proc' now works on running processes on FreeBSD systems and core
873 files created on FreeBSD systems.
875 * C expressions can now use _Alignof, and C++ expressions can now use
878 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
879 the vector length while the process is running.
885 Control display of debugging info regarding the FreeBSD native target.
887 set|show varsize-limit
888 This new setting allows the user to control the maximum size of Ada
889 objects being printed when those objects have a variable type,
890 instead of that maximum size being hardcoded to 65536 bytes.
892 set|show record btrace cpu
893 Controls the processor to be used for enabling errata workarounds for
896 maint check libthread-db
897 Run integrity checks on the current inferior's thread debugging
900 maint set check-libthread-db (on|off)
901 maint show check-libthread-db
902 Control whether to run integrity checks on inferior specific thread
903 debugging libraries as they are loaded. The default is not to
908 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
910 ** The commands attached to a breakpoint can be set by assigning to
911 the breakpoint's "commands" field.
913 ** gdb.execute can now execute multi-line gdb commands.
915 ** The new functions gdb.convenience_variable and
916 gdb.set_convenience_variable can be used to get and set the value
917 of convenience variables.
919 ** A gdb.Parameter will no longer print the "set" help text on an
920 ordinary "set"; instead by default a "set" will be silent unless
921 the get_set_string method returns a non-empty string.
925 RiscV ELF riscv*-*-elf
927 * Removed targets and native configurations
929 m88k running OpenBSD m88*-*-openbsd*
930 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
931 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
932 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
934 * Aarch64/Linux hardware watchpoints improvements
936 Hardware watchpoints on unaligned addresses are now properly
937 supported when running Linux kernel 4.10 or higher: read and access
938 watchpoints are no longer spuriously missed, and all watchpoints
939 lengths between 1 and 8 bytes are supported. On older kernels,
940 watchpoints set on unaligned addresses are no longer missed, with
941 the tradeoff that there is a possibility of false hits being
946 --enable-codesign=CERT
947 This can be used to invoke "codesign -s CERT" after building gdb.
948 This option is useful on macOS, where code signing is required for
949 gdb to work properly.
951 --disable-gdbcli has been removed
952 This is now silently accepted, but does nothing.
954 *** Changes in GDB 8.1
956 * GDB now supports dynamically creating arbitrary register groups specified
957 in XML target descriptions. This allows for finer grain grouping of
958 registers on systems with a large amount of registers.
960 * The 'ptype' command now accepts a '/o' flag, which prints the
961 offsets and sizes of fields in a struct, like the pahole(1) tool.
963 * New "--readnever" command line option instructs GDB to not read each
964 symbol file's symbolic debug information. This makes startup faster
965 but at the expense of not being able to perform symbolic debugging.
966 This option is intended for use cases where symbolic debugging will
967 not be used, e.g., when you only need to dump the debuggee's core.
969 * GDB now uses the GNU MPFR library, if available, to emulate target
970 floating-point arithmetic during expression evaluation when the target
971 uses different floating-point formats than the host. At least version
972 3.1 of GNU MPFR is required.
974 * GDB now supports access to the guarded-storage-control registers and the
975 software-based guarded-storage broadcast control registers on IBM z14.
977 * On Unix systems, GDB now supports transmitting environment variables
978 that are to be set or unset to GDBserver. These variables will
979 affect the environment to be passed to the remote inferior.
981 To inform GDB of environment variables that are to be transmitted to
982 GDBserver, use the "set environment" command. Only user set
983 environment variables are sent to GDBserver.
985 To inform GDB of environment variables that are to be unset before
986 the remote inferior is started by the GDBserver, use the "unset
987 environment" command.
989 * Completion improvements
991 ** GDB can now complete function parameters in linespecs and
992 explicit locations without quoting. When setting breakpoints,
993 quoting around functions names to help with TAB-completion is
994 generally no longer necessary. For example, this now completes
997 (gdb) b function(in[TAB]
998 (gdb) b function(int)
1000 Related, GDB is no longer confused with completing functions in
1001 C++ anonymous namespaces:
1004 (gdb) b (anonymous namespace)::[TAB][TAB]
1005 (anonymous namespace)::a_function()
1006 (anonymous namespace)::b_function()
1008 ** GDB now has much improved linespec and explicit locations TAB
1009 completion support, that better understands what you're
1010 completing and offers better suggestions. For example, GDB no
1011 longer offers data symbols as possible completions when you're
1012 setting a breakpoint.
1014 ** GDB now TAB-completes label symbol names.
1016 ** The "complete" command now mimics TAB completion accurately.
1018 * New command line options (gcore)
1021 Dump all memory mappings.
1023 * Breakpoints on C++ functions are now set on all scopes by default
1025 By default, breakpoints on functions/methods are now interpreted as
1026 specifying all functions with the given name ignoring missing
1027 leading scopes (namespaces and classes).
1029 For example, assuming a C++ program with symbols named:
1034 both commands "break func()" and "break B::func()" set a breakpoint
1037 You can use the new flag "-qualified" to override this. This makes
1038 GDB interpret the specified function name as a complete
1039 fully-qualified name instead. For example, using the same C++
1040 program, the "break -q B::func" command sets a breakpoint on
1041 "B::func", only. A parameter has been added to the Python
1042 gdb.Breakpoint constructor to achieve the same result when creating
1043 a breakpoint from Python.
1045 * Breakpoints on functions marked with C++ ABI tags
1047 GDB can now set breakpoints on functions marked with C++ ABI tags
1048 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1049 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1051 Functions with a C++11 abi tag are demangled/displayed like this:
1053 function[abi:cxx11](int)
1056 You can now set a breakpoint on such functions simply as if they had
1059 (gdb) b function(int)
1061 Or if you need to disambiguate between tags, like:
1063 (gdb) b function[abi:other_tag](int)
1065 Tab completion was adjusted accordingly as well.
1069 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1070 gdb.new_thread are emitted. See the manual for further
1071 description of these.
1073 ** A new function, "gdb.rbreak" has been added to the Python API.
1074 This function allows the setting of a large number of breakpoints
1075 via a regex pattern in Python. See the manual for further details.
1077 ** Python breakpoints can now accept explicit locations. See the
1078 manual for a further description of this feature.
1081 * New features in the GDB remote stub, GDBserver
1083 ** GDBserver is now able to start inferior processes with a
1084 specified initial working directory.
1086 The user can set the desired working directory to be used from
1087 GDB using the new "set cwd" command.
1089 ** New "--selftest" command line option runs some GDBserver self
1090 tests. These self tests are disabled in releases.
1092 ** On Unix systems, GDBserver now does globbing expansion and variable
1093 substitution in inferior command line arguments.
1095 This is done by starting inferiors using a shell, like GDB does.
1096 See "set startup-with-shell" in the user manual for how to disable
1097 this from GDB when using "target extended-remote". When using
1098 "target remote", you can disable the startup with shell by using the
1099 new "--no-startup-with-shell" GDBserver command line option.
1101 ** On Unix systems, GDBserver now supports receiving environment
1102 variables that are to be set or unset from GDB. These variables
1103 will affect the environment to be passed to the inferior.
1105 * When catching an Ada exception raised with a message, GDB now prints
1106 the message in the catchpoint hit notification. In GDB/MI mode, that
1107 information is provided as an extra field named "exception-message"
1108 in the *stopped notification.
1110 * Trait objects can now be inspected When debugging Rust code. This
1111 requires compiler support which will appear in Rust 1.24.
1113 * New remote packets
1115 QEnvironmentHexEncoded
1116 Inform GDBserver of an environment variable that is to be passed to
1117 the inferior when starting it.
1120 Inform GDBserver of an environment variable that is to be unset
1121 before starting the remote inferior.
1124 Inform GDBserver that the environment should be reset (i.e.,
1125 user-set environment variables should be unset).
1128 Indicates whether the inferior must be started with a shell or not.
1131 Tell GDBserver that the inferior to be started should use a specific
1134 * The "maintenance print c-tdesc" command now takes an optional
1135 argument which is the file name of XML target description.
1137 * The "maintenance selftest" command now takes an optional argument to
1138 filter the tests to be run.
1140 * The "enable", and "disable" commands now accept a range of
1141 breakpoint locations, e.g. "enable 1.3-5".
1146 Set and show the current working directory for the inferior.
1148 set|show compile-gcc
1149 Set and show compilation command used for compiling and injecting code
1150 with the 'compile' commands.
1152 set debug separate-debug-file
1153 show debug separate-debug-file
1154 Control the display of debug output about separate debug file search.
1156 set dump-excluded-mappings
1157 show dump-excluded-mappings
1158 Control whether mappings marked with the VM_DONTDUMP flag should be
1159 dumped when generating a core file.
1161 maint info selftests
1162 List the registered selftests.
1165 Start the debugged program stopping at the first instruction.
1168 Control display of debugging messages related to OpenRISC targets.
1170 set|show print type nested-type-limit
1171 Set and show the limit of nesting level for nested types that the
1172 type printer will show.
1174 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1177 * Safer/improved support for debugging with no debug info
1179 GDB no longer assumes functions with no debug information return
1182 This means that GDB now refuses to call such functions unless you
1183 tell it the function's type, by either casting the call to the
1184 declared return type, or by casting the function to a function
1185 pointer of the right type, and calling that:
1187 (gdb) p getenv ("PATH")
1188 'getenv' has unknown return type; cast the call to its declared return type
1189 (gdb) p (char *) getenv ("PATH")
1190 $1 = 0x7fffffffe "/usr/local/bin:/"...
1191 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1192 $2 = 0x7fffffffe "/usr/local/bin:/"...
1194 Similarly, GDB no longer assumes that global variables with no debug
1195 info have type 'int', and refuses to print the variable's value
1196 unless you tell it the variable's type:
1199 'var' has unknown type; cast it to its declared type
1203 * New native configurations
1205 FreeBSD/aarch64 aarch64*-*-freebsd*
1206 FreeBSD/arm arm*-*-freebsd*
1210 FreeBSD/aarch64 aarch64*-*-freebsd*
1211 FreeBSD/arm arm*-*-freebsd*
1212 OpenRISC ELF or1k*-*-elf
1214 * Removed targets and native configurations
1216 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1218 *** Changes in GDB 8.0
1220 * GDB now supports access to the PKU register on GNU/Linux. The register is
1221 added by the Memory Protection Keys for Userspace feature which will be
1222 available in future Intel CPUs.
1224 * GDB now supports C++11 rvalue references.
1228 ** New functions to start, stop and access a running btrace recording.
1229 ** Rvalue references are now supported in gdb.Type.
1231 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1234 * Building GDB and GDBserver now requires a C++11 compiler.
1236 For example, GCC 4.8 or later.
1238 It is no longer possible to build GDB or GDBserver with a C
1239 compiler. The --disable-build-with-cxx configure option has been
1242 * Building GDB and GDBserver now requires GNU make >= 3.81.
1244 It is no longer supported to build GDB or GDBserver with another
1245 implementation of the make program or an earlier version of GNU make.
1247 * Native debugging on MS-Windows supports command-line redirection
1249 Command-line arguments used for starting programs on MS-Windows can
1250 now include redirection symbols supported by native Windows shells,
1251 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1252 as "run", "start", and "set args", as well as the corresponding MI
1255 * Support for thread names on MS-Windows.
1257 GDB now catches and handles the special exception that programs
1258 running on MS-Windows use to assign names to threads in the
1261 * Support for Java programs compiled with gcj has been removed.
1263 * User commands now accept an unlimited number of arguments.
1264 Previously, only up to 10 was accepted.
1266 * The "eval" command now expands user-defined command arguments.
1268 This makes it easier to process a variable number of arguments:
1273 eval "print $arg%d", $i
1278 * Target descriptions can now describe registers for sparc32 and sparc64.
1280 * GDB now supports DWARF version 5 (debug information format).
1281 Its .debug_names index is not yet supported.
1283 * New native configurations
1285 FreeBSD/mips mips*-*-freebsd
1289 Synopsys ARC arc*-*-elf32
1290 FreeBSD/mips mips*-*-freebsd
1292 * Removed targets and native configurations
1294 Alpha running FreeBSD alpha*-*-freebsd*
1295 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1300 Erases all the flash memory regions reported by the target.
1302 maint print arc arc-instruction address
1303 Print internal disassembler information about instruction at a given address.
1307 set disassembler-options
1308 show disassembler-options
1309 Controls the passing of target specific information to the disassembler.
1310 If it is necessary to specify more than one disassembler option then
1311 multiple options can be placed together into a comma separated list.
1312 The default value is the empty string. Currently, the only supported
1313 targets are ARM, PowerPC and S/390.
1318 Erases all the flash memory regions reported by the target. This is
1319 equivalent to the CLI command flash-erase.
1321 -file-list-shared-libraries
1322 List the shared libraries in the program. This is
1323 equivalent to the CLI command "info shared".
1326 Catchpoints stopping the program when Ada exceptions are
1327 handled. This is equivalent to the CLI command "catch handlers".
1329 *** Changes in GDB 7.12
1331 * GDB and GDBserver now build with a C++ compiler by default.
1333 The --enable-build-with-cxx configure option is now enabled by
1334 default. One must now explicitly configure with
1335 --disable-build-with-cxx in order to build with a C compiler. This
1336 option will be removed in a future release.
1338 * GDBserver now supports recording btrace without maintaining an active
1341 * GDB now supports a negative repeat count in the 'x' command to examine
1342 memory backward from the given address. For example:
1345 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1346 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1347 (gdb) x/-5i 0x0000000000400580
1348 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1349 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1350 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1351 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1352 0x40057b <main(int, char**)+25>:
1353 callq 0x400536 <Func1(int, char const*)>
1355 * Fortran: Support structures with fields of dynamic types and
1356 arrays of dynamic types.
1358 * The symbol dumping maintenance commands have new syntax.
1359 maint print symbols [-pc address] [--] [filename]
1360 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1361 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1362 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1363 maint print msymbols [-objfile objfile] [--] [filename]
1365 * GDB now supports multibit bitfields and enums in target register
1368 * New Python-based convenience function $_as_string(val), which returns
1369 the textual representation of a value. This function is especially
1370 useful to obtain the text label of an enum value.
1372 * Intel MPX bound violation handling.
1374 Segmentation faults caused by a Intel MPX boundary violation
1375 now display the kind of violation (upper or lower), the memory
1376 address accessed and the memory bounds, along with the usual
1377 signal received and code location.
1381 Program received signal SIGSEGV, Segmentation fault
1382 Upper bound violation while accessing address 0x7fffffffc3b3
1383 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1384 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1386 * Rust language support.
1387 GDB now supports debugging programs written in the Rust programming
1388 language. See https://www.rust-lang.org/ for more information about
1391 * Support for running interpreters on specified input/output devices
1393 GDB now supports a new mechanism that allows frontends to provide
1394 fully featured GDB console views, as a better alternative to
1395 building such views on top of the "-interpreter-exec console"
1396 command. See the new "new-ui" command below. With that command,
1397 frontends can now start GDB in the traditional command-line mode
1398 running in an embedded terminal emulator widget, and create a
1399 separate MI interpreter running on a specified i/o device. In this
1400 way, GDB handles line editing, history, tab completion, etc. in the
1401 console all by itself, and the GUI uses the separate MI interpreter
1402 for its own control and synchronization, invisible to the command
1405 * The "catch syscall" command catches groups of related syscalls.
1407 The "catch syscall" command now supports catching a group of related
1408 syscalls using the 'group:' or 'g:' prefix.
1413 skip -gfile file-glob-pattern
1414 skip -function function
1415 skip -rfunction regular-expression
1416 A generalized form of the skip command, with new support for
1417 glob-style file names and regular expressions for function names.
1418 Additionally, a file spec and a function spec may now be combined.
1420 maint info line-table REGEXP
1421 Display the contents of GDB's internal line table data structure.
1424 Run any GDB unit tests that were compiled in.
1427 Start a new user interface instance running INTERP as interpreter,
1428 using the TTY file for input/output.
1432 ** gdb.Breakpoint objects have a new attribute "pending", which
1433 indicates whether the breakpoint is pending.
1434 ** Three new breakpoint-related events have been added:
1435 gdb.breakpoint_created, gdb.breakpoint_modified, and
1436 gdb.breakpoint_deleted.
1438 signal-event EVENTID
1439 Signal ("set") the given MS-Windows event object. This is used in
1440 conjunction with the Windows JIT debugging (AeDebug) support, where
1441 the OS suspends a crashing process until a debugger can attach to
1442 it. Resuming the crashing process, in order to debug it, is done by
1443 signalling an event.
1445 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1446 was added in GDBserver, including JIT compiling fast tracepoint's
1447 conditional expression bytecode into native code.
1449 * Support for various remote target protocols and ROM monitors has
1452 target m32rsdi Remote M32R debugging over SDI
1453 target mips MIPS remote debugging protocol
1454 target pmon PMON ROM monitor
1455 target ddb NEC's DDB variant of PMON for Vr4300
1456 target rockhopper NEC RockHopper variant of PMON
1457 target lsi LSI variant of PMO
1459 * Support for tracepoints and fast tracepoints on powerpc-linux,
1460 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1461 including JIT compiling fast tracepoint's conditional expression
1462 bytecode into native code.
1464 * MI async record =record-started now includes the method and format used for
1465 recording. For example:
1467 =record-started,thread-group="i1",method="btrace",format="bts"
1469 * MI async record =thread-selected now includes the frame field. For example:
1471 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1475 Andes NDS32 nds32*-*-elf
1477 *** Changes in GDB 7.11
1479 * GDB now supports debugging kernel-based threads on FreeBSD.
1481 * Per-inferior thread numbers
1483 Thread numbers are now per inferior instead of global. If you're
1484 debugging multiple inferiors, GDB displays thread IDs using a
1485 qualified INF_NUM.THR_NUM form. For example:
1489 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1490 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1491 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1492 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1494 As consequence, thread numbers as visible in the $_thread
1495 convenience variable and in Python's InferiorThread.num attribute
1496 are no longer unique between inferiors.
1498 GDB now maintains a second thread ID per thread, referred to as the
1499 global thread ID, which is the new equivalent of thread numbers in
1500 previous releases. See also $_gthread below.
1502 For backwards compatibility, MI's thread IDs always refer to global
1505 * Commands that accept thread IDs now accept the qualified
1506 INF_NUM.THR_NUM form as well. For example:
1509 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1512 * In commands that accept a list of thread IDs, you can now refer to
1513 all threads of an inferior using a star wildcard. GDB accepts
1514 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1515 refer to all threads of the current inferior. For example, "info
1518 * You can use "info threads -gid" to display the global thread ID of
1521 * The new convenience variable $_gthread holds the global number of
1524 * The new convenience variable $_inferior holds the number of the
1527 * GDB now displays the ID and name of the thread that hit a breakpoint
1528 or received a signal, if your program is multi-threaded. For
1531 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1532 Thread 1 "main" received signal SIGINT, Interrupt.
1534 * Record btrace now supports non-stop mode.
1536 * Support for tracepoints on aarch64-linux was added in GDBserver.
1538 * The 'record instruction-history' command now indicates speculative execution
1539 when using the Intel Processor Trace recording format.
1541 * GDB now allows users to specify explicit locations, bypassing
1542 the linespec parser. This feature is also available to GDB/MI
1545 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1546 GDB now is able to debug both AArch64 applications and ARM applications
1549 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1550 including JIT compiling fast tracepoint's conditional expression bytecode
1553 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1555 * "info threads", "info inferiors", "info display", "info checkpoints"
1556 and "maint info program-spaces" now list the corresponding items in
1557 ascending ID order, for consistency with all other "info" commands.
1559 * In Ada, the overloads selection menu has been enhanced to display the
1560 parameter types and the return types for the matching overloaded subprograms.
1564 maint set target-non-stop (on|off|auto)
1565 maint show target-non-stop
1566 Control whether GDB targets always operate in non-stop mode even if
1567 "set non-stop" is "off". The default is "auto", meaning non-stop
1568 mode is enabled if supported by the target.
1570 maint set bfd-sharing
1571 maint show bfd-sharing
1572 Control the reuse of bfd objects.
1575 show debug bfd-cache
1576 Control display of debugging info regarding bfd caching.
1580 Control display of debugging info regarding FreeBSD threads.
1582 set remote multiprocess-extensions-packet
1583 show remote multiprocess-extensions-packet
1584 Set/show the use of the remote protocol multiprocess extensions.
1586 set remote thread-events
1587 show remote thread-events
1588 Set/show the use of thread create/exit events.
1590 set ada print-signatures on|off
1591 show ada print-signatures"
1592 Control whether parameter types and return types are displayed in overloads
1593 selection menus. It is activated (@code{on}) by default.
1597 Controls the maximum size of memory, in bytes, that GDB will
1598 allocate for value contents. Prevents incorrect programs from
1599 causing GDB to allocate overly large buffers. Default is 64k.
1601 * The "disassemble" command accepts a new modifier: /s.
1602 It prints mixed source+disassembly like /m with two differences:
1603 - disassembled instructions are now printed in program order, and
1604 - and source for all relevant files is now printed.
1605 The "/m" option is now considered deprecated: its "source-centric"
1606 output hasn't proved useful in practice.
1608 * The "record instruction-history" command accepts a new modifier: /s.
1609 It behaves exactly like /m and prints mixed source+disassembly.
1611 * The "set scheduler-locking" command supports a new mode "replay".
1612 It behaves like "off" in record mode and like "on" in replay mode.
1614 * Support for various ROM monitors has been removed:
1616 target dbug dBUG ROM monitor for Motorola ColdFire
1617 target picobug Motorola picobug monitor
1618 target dink32 DINK32 ROM monitor for PowerPC
1619 target m32r Renesas M32R/D ROM monitor
1620 target mon2000 mon2000 ROM monitor
1621 target ppcbug PPCBUG ROM monitor for PowerPC
1623 * Support for reading/writing memory and extracting values on architectures
1624 whose memory is addressable in units of any integral multiple of 8 bits.
1627 Allows to break when an Ada exception is handled.
1629 * New remote packets
1632 Indicates that an exec system call was executed.
1634 exec-events feature in qSupported
1635 The qSupported packet allows GDB to request support for exec
1636 events using the new 'gdbfeature' exec-event, and the qSupported
1637 response can contain the corresponding 'stubfeature'. Set and
1638 show commands can be used to display whether these features are enabled.
1641 Equivalent to interrupting with the ^C character, but works in
1644 thread created stop reason (T05 create:...)
1645 Indicates that the thread was just created and is stopped at entry.
1647 thread exit stop reply (w exitcode;tid)
1648 Indicates that the thread has terminated.
1651 Enables/disables thread create and exit event reporting. For
1652 example, this is used in non-stop mode when GDB stops a set of
1653 threads and synchronously waits for the their corresponding stop
1654 replies. Without exit events, if one of the threads exits, GDB
1655 would hang forever not knowing that it should no longer expect a
1656 stop for that same thread.
1659 Indicates that there are no resumed threads left in the target (all
1660 threads are stopped). The remote stub reports support for this stop
1661 reply to GDB's qSupported query.
1664 Enables/disables catching syscalls from the inferior process.
1665 The remote stub reports support for this packet to GDB's qSupported query.
1667 syscall_entry stop reason
1668 Indicates that a syscall was just called.
1670 syscall_return stop reason
1671 Indicates that a syscall just returned.
1673 * Extended-remote exec events
1675 ** GDB now has support for exec events on extended-remote Linux targets.
1676 For such targets with Linux kernels 2.5.46 and later, this enables
1677 follow-exec-mode and exec catchpoints.
1679 set remote exec-event-feature-packet
1680 show remote exec-event-feature-packet
1681 Set/show the use of the remote exec event feature.
1683 * Thread names in remote protocol
1685 The reply to qXfer:threads:read may now include a name attribute for each
1688 * Target remote mode fork and exec events
1690 ** GDB now has support for fork and exec events on target remote mode
1691 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1692 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1693 fork and exec catchpoints.
1695 * Remote syscall events
1697 ** GDB now has support for catch syscall on remote Linux targets,
1698 currently enabled on x86/x86_64 architectures.
1700 set remote catch-syscall-packet
1701 show remote catch-syscall-packet
1702 Set/show the use of the remote catch syscall feature.
1706 ** The -var-set-format command now accepts the zero-hexadecimal
1707 format. It outputs data in hexadecimal format with zero-padding on the
1712 ** gdb.InferiorThread objects have a new attribute "global_num",
1713 which refers to the thread's global thread ID. The existing
1714 "num" attribute now refers to the thread's per-inferior number.
1715 See "Per-inferior thread numbers" above.
1716 ** gdb.InferiorThread objects have a new attribute "inferior", which
1717 is the Inferior object the thread belongs to.
1719 *** Changes in GDB 7.10
1721 * Support for process record-replay and reverse debugging on aarch64*-linux*
1722 targets has been added. GDB now supports recording of A64 instruction set
1723 including advance SIMD instructions.
1725 * Support for Sun's version of the "stabs" debug file format has been removed.
1727 * GDB now honors the content of the file /proc/PID/coredump_filter
1728 (PID is the process ID) on GNU/Linux systems. This file can be used
1729 to specify the types of memory mappings that will be included in a
1730 corefile. For more information, please refer to the manual page of
1731 "core(5)". GDB also has a new command: "set use-coredump-filter
1732 on|off". It allows to set whether GDB will read the content of the
1733 /proc/PID/coredump_filter file when generating a corefile.
1735 * The "info os" command on GNU/Linux can now display information on
1737 "info os cpus" Listing of all cpus/cores on the system
1739 * GDB has two new commands: "set serial parity odd|even|none" and
1740 "show serial parity". These allows to set or show parity for the
1743 * The "info source" command now displays the producer string if it was
1744 present in the debug info. This typically includes the compiler version
1745 and may include things like its command line arguments.
1747 * The "info dll", an alias of the "info sharedlibrary" command,
1748 is now available on all platforms.
1750 * Directory names supplied to the "set sysroot" commands may be
1751 prefixed with "target:" to tell GDB to access shared libraries from
1752 the target system, be it local or remote. This replaces the prefix
1753 "remote:". The default sysroot has been changed from "" to
1754 "target:". "remote:" is automatically converted to "target:" for
1755 backward compatibility.
1757 * The system root specified by "set sysroot" will be prepended to the
1758 filename of the main executable (if reported to GDB as absolute by
1759 the operating system) when starting processes remotely, and when
1760 attaching to already-running local or remote processes.
1762 * GDB now supports automatic location and retrieval of executable
1763 files from remote targets. Remote debugging can now be initiated
1764 using only a "target remote" or "target extended-remote" command
1765 (no "set sysroot" or "file" commands are required). See "New remote
1768 * The "dump" command now supports verilog hex format.
1770 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1772 * On GNU/Linux, GDB and gdbserver are now able to access executable
1773 and shared library files without a "set sysroot" command when
1774 attaching to processes running in different mount namespaces from
1775 the debugger. This makes it possible to attach to processes in
1776 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1777 See "New remote packets" below.
1779 * The "tui reg" command now provides completion for all of the
1780 available register groups, including target specific groups.
1782 * The HISTSIZE environment variable is no longer read when determining
1783 the size of GDB's command history. GDB now instead reads the dedicated
1784 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1785 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1790 ** Memory ports can now be unbuffered.
1794 ** gdb.Objfile objects have a new attribute "username",
1795 which is the name of the objfile as specified by the user,
1796 without, for example, resolving symlinks.
1797 ** You can now write frame unwinders in Python.
1798 ** gdb.Type objects have a new method "optimized_out",
1799 returning optimized out gdb.Value instance of this type.
1800 ** gdb.Value objects have new methods "reference_value" and
1801 "const_value" which return a reference to the value and a
1802 "const" version of the value respectively.
1806 maint print symbol-cache
1807 Print the contents of the symbol cache.
1809 maint print symbol-cache-statistics
1810 Print statistics of symbol cache usage.
1812 maint flush-symbol-cache
1813 Flush the contents of the symbol cache.
1817 Start branch trace recording using Branch Trace Store (BTS) format.
1820 Evaluate expression by using the compiler and print result.
1824 Explicit commands for enabling and disabling tui mode.
1827 set mpx bound on i386 and amd64
1828 Support for bound table investigation on Intel MPX enabled applications.
1832 Start branch trace recording using Intel Processor Trace format.
1835 Print information about branch tracing internals.
1837 maint btrace packet-history
1838 Print the raw branch tracing data.
1840 maint btrace clear-packet-history
1841 Discard the stored raw branch tracing data.
1844 Discard all branch tracing data. It will be fetched and processed
1845 anew by the next "record" command.
1850 Renamed from "set debug dwarf2-die".
1851 show debug dwarf-die
1852 Renamed from "show debug dwarf2-die".
1854 set debug dwarf-read
1855 Renamed from "set debug dwarf2-read".
1856 show debug dwarf-read
1857 Renamed from "show debug dwarf2-read".
1859 maint set dwarf always-disassemble
1860 Renamed from "maint set dwarf2 always-disassemble".
1861 maint show dwarf always-disassemble
1862 Renamed from "maint show dwarf2 always-disassemble".
1864 maint set dwarf max-cache-age
1865 Renamed from "maint set dwarf2 max-cache-age".
1866 maint show dwarf max-cache-age
1867 Renamed from "maint show dwarf2 max-cache-age".
1869 set debug dwarf-line
1870 show debug dwarf-line
1871 Control display of debugging info regarding DWARF line processing.
1874 show max-completions
1875 Set the maximum number of candidates to be considered during
1876 completion. The default value is 200. This limit allows GDB
1877 to avoid generating large completion lists, the computation of
1878 which can cause the debugger to become temporarily unresponsive.
1880 set history remove-duplicates
1881 show history remove-duplicates
1882 Control the removal of duplicate history entries.
1884 maint set symbol-cache-size
1885 maint show symbol-cache-size
1886 Control the size of the symbol cache.
1888 set|show record btrace bts buffer-size
1889 Set and show the size of the ring buffer used for branch tracing in
1891 The obtained size may differ from the requested size. Use "info
1892 record" to see the obtained buffer size.
1894 set debug linux-namespaces
1895 show debug linux-namespaces
1896 Control display of debugging info regarding Linux namespaces.
1898 set|show record btrace pt buffer-size
1899 Set and show the size of the ring buffer used for branch tracing in
1900 Intel Processor Trace format.
1901 The obtained size may differ from the requested size. Use "info
1902 record" to see the obtained buffer size.
1904 maint set|show btrace pt skip-pad
1905 Set and show whether PAD packets are skipped when computing the
1908 * The command 'thread apply all' can now support new option '-ascending'
1909 to call its specified command for all threads in ascending order.
1911 * Python/Guile scripting
1913 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1914 special section named `.debug_gdb_scripts'.
1916 * New remote packets
1918 qXfer:btrace-conf:read
1919 Return the branch trace configuration for the current thread.
1921 Qbtrace-conf:bts:size
1922 Set the requested ring buffer size for branch tracing in BTS format.
1925 Enable Intel Processor Trace-based branch tracing for the current
1926 process. The remote stub reports support for this packet to GDB's
1929 Qbtrace-conf:pt:size
1930 Set the requested ring buffer size for branch tracing in Intel Processor
1934 Indicates a memory breakpoint instruction was executed, irrespective
1935 of whether it was GDB that planted the breakpoint or the breakpoint
1936 is hardcoded in the program. This is required for correct non-stop
1940 Indicates the target stopped for a hardware breakpoint. This is
1941 required for correct non-stop mode operation.
1944 Return information about files on the remote system.
1946 qXfer:exec-file:read
1947 Return the full absolute name of the file that was executed to
1948 create a process running on the remote system.
1951 Select the filesystem on which vFile: operations with filename
1952 arguments will operate. This is required for GDB to be able to
1953 access files on remote targets where the remote stub does not
1954 share a common filesystem with the inferior(s).
1957 Indicates that a fork system call was executed.
1960 Indicates that a vfork system call was executed.
1962 vforkdone stop reason
1963 Indicates that a vfork child of the specified process has executed
1964 an exec or exit, allowing the vfork parent to resume execution.
1966 fork-events and vfork-events features in qSupported
1967 The qSupported packet allows GDB to request support for fork and
1968 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1969 and the qSupported response can contain the corresponding
1970 'stubfeatures'. Set and show commands can be used to display
1971 whether these features are enabled.
1973 * Extended-remote fork events
1975 ** GDB now has support for fork events on extended-remote Linux
1976 targets. For targets with Linux kernels 2.5.60 and later, this
1977 enables follow-fork-mode and detach-on-fork for both fork and
1978 vfork, as well as fork and vfork catchpoints.
1980 * The info record command now shows the recording format and the
1981 branch tracing configuration for the current thread when using
1982 the btrace record target.
1983 For the BTS format, it shows the ring buffer size.
1985 * GDB now has support for DTrace USDT (Userland Static Defined
1986 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1988 * GDB now supports access to vector registers on S/390 GNU/Linux
1991 * Removed command line options
1993 -xdb HP-UX XDB compatibility mode.
1995 * Removed targets and native configurations
1997 HP/PA running HP-UX hppa*-*-hpux*
1998 Itanium running HP-UX ia64-*-hpux*
2000 * New configure options
2003 This configure option allows the user to build GDB with support for
2004 Intel Processor Trace (default: auto). This requires libipt.
2006 --with-libipt-prefix=PATH
2007 Specify the path to the version of libipt that GDB should use.
2008 $PATH/include should contain the intel-pt.h header and
2009 $PATH/lib should contain the libipt.so library.
2011 *** Changes in GDB 7.9.1
2015 ** Xmethods can now specify a result type.
2017 *** Changes in GDB 7.9
2019 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2023 ** You can now access frame registers from Python scripts.
2024 ** New attribute 'producer' for gdb.Symtab objects.
2025 ** gdb.Objfile objects have a new attribute "progspace",
2026 which is the gdb.Progspace object of the containing program space.
2027 ** gdb.Objfile objects have a new attribute "owner".
2028 ** gdb.Objfile objects have a new attribute "build_id",
2029 which is the build ID generated when the file was built.
2030 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2031 ** A new event "gdb.clear_objfiles" has been added, triggered when
2032 selecting a new file to debug.
2033 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2034 ** New function gdb.lookup_objfile.
2036 New events which are triggered when GDB modifies the state of the
2039 ** gdb.events.inferior_call_pre: Function call is about to be made.
2040 ** gdb.events.inferior_call_post: Function call has just been made.
2041 ** gdb.events.memory_changed: A memory location has been altered.
2042 ** gdb.events.register_changed: A register has been altered.
2044 * New Python-based convenience functions:
2046 ** $_caller_is(name [, number_of_frames])
2047 ** $_caller_matches(regexp [, number_of_frames])
2048 ** $_any_caller_is(name [, number_of_frames])
2049 ** $_any_caller_matches(regexp [, number_of_frames])
2051 * GDB now supports the compilation and injection of source code into
2052 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2053 to compile the source code to object code, and if successful, inject
2054 and execute that code within the current context of the inferior.
2055 Currently the C language is supported. The commands used to
2056 interface with this new feature are:
2058 compile code [-raw|-r] [--] [source code]
2059 compile file [-raw|-r] filename
2063 demangle [-l language] [--] name
2064 Demangle "name" in the specified language, or the current language
2065 if elided. This command is renamed from the "maint demangle" command.
2066 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2067 as "maint demangler-warning".
2069 queue-signal signal-name-or-number
2070 Queue a signal to be delivered to the thread when it is resumed.
2072 add-auto-load-scripts-directory directory
2073 Add entries to the list of directories from which to load auto-loaded
2076 maint print user-registers
2077 List all currently available "user" registers.
2079 compile code [-r|-raw] [--] [source code]
2080 Compile, inject, and execute in the inferior the executable object
2081 code produced by compiling the provided source code.
2083 compile file [-r|-raw] filename
2084 Compile and inject into the inferior the executable object code
2085 produced by compiling the source code stored in the filename
2088 * On resume, GDB now always passes the signal the program had stopped
2089 for to the thread the signal was sent to, even if the user changed
2090 threads before resuming. Previously GDB would often (but not
2091 always) deliver the signal to the thread that happens to be current
2094 * Conversely, the "signal" command now consistently delivers the
2095 requested signal to the current thread. GDB now asks for
2096 confirmation if the program had stopped for a signal and the user
2097 switched threads meanwhile.
2099 * "breakpoint always-inserted" modes "off" and "auto" merged.
2101 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2102 won't remove breakpoints from the target until all threads stop,
2103 even in non-stop mode. The "auto" mode has been removed, and "off"
2104 is now the default mode.
2108 set debug symbol-lookup
2109 show debug symbol-lookup
2110 Control display of debugging info regarding symbol lookup.
2114 ** The -list-thread-groups command outputs an exit-code field for
2115 inferiors that have exited.
2119 MIPS SDE mips*-sde*-elf*
2123 Support for these obsolete configurations has been removed.
2125 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2126 SGI Irix-5.x mips-*-irix5*
2127 SGI Irix-6.x mips-*-irix6*
2128 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2129 VAX running Ultrix vax-*-ultrix*
2131 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2132 and "assf"), have been removed. Use the "sharedlibrary" command, or
2133 its alias "share", instead.
2135 *** Changes in GDB 7.8
2137 * New command line options
2140 This is an alias for the --data-directory option.
2142 * GDB supports printing and modifying of variable length automatic arrays
2143 as specified in ISO C99.
2145 * The ARM simulator now supports instruction level tracing
2146 with or without disassembly.
2150 GDB now has support for scripting using Guile. Whether this is
2151 available is determined at configure time.
2152 Guile version 2.0 or greater is required.
2153 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2155 * New commands (for set/show, see "New options" below)
2159 Invoke CODE by passing it to the Guile interpreter.
2163 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2165 info auto-load guile-scripts [regexp]
2166 Print the list of automatically loaded Guile scripts.
2168 * The source command is now capable of sourcing Guile scripts.
2169 This feature is dependent on the debugger being built with Guile support.
2173 set print symbol-loading (off|brief|full)
2174 show print symbol-loading
2175 Control whether to print informational messages when loading symbol
2176 information for a file. The default is "full", but when debugging
2177 programs with large numbers of shared libraries the amount of output
2178 becomes less useful.
2180 set guile print-stack (none|message|full)
2181 show guile print-stack
2182 Show a stack trace when an error is encountered in a Guile script.
2184 set auto-load guile-scripts (on|off)
2185 show auto-load guile-scripts
2186 Control auto-loading of Guile script files.
2188 maint ada set ignore-descriptive-types (on|off)
2189 maint ada show ignore-descriptive-types
2190 Control whether the debugger should ignore descriptive types in Ada
2191 programs. The default is not to ignore the descriptive types. See
2192 the user manual for more details on descriptive types and the intended
2193 usage of this option.
2195 set auto-connect-native-target
2197 Control whether GDB is allowed to automatically connect to the
2198 native target for the run, attach, etc. commands when not connected
2199 to any target yet. See also "target native" below.
2201 set record btrace replay-memory-access (read-only|read-write)
2202 show record btrace replay-memory-access
2203 Control what memory accesses are allowed during replay.
2205 maint set target-async (on|off)
2206 maint show target-async
2207 This controls whether GDB targets operate in synchronous or
2208 asynchronous mode. Normally the default is asynchronous, if it is
2209 available; but this can be changed to more easily debug problems
2210 occurring only in synchronous mode.
2212 set mi-async (on|off)
2214 Control whether MI asynchronous mode is preferred. This supersedes
2215 "set target-async" of previous GDB versions.
2217 * "set target-async" is deprecated as a CLI option and is now an alias
2218 for "set mi-async" (only puts MI into async mode).
2220 * Background execution commands (e.g., "c&", "s&", etc.) are now
2221 possible ``out of the box'' if the target supports them. Previously
2222 the user would need to explicitly enable the possibility with the
2223 "set target-async on" command.
2225 * New features in the GDB remote stub, GDBserver
2227 ** New option --debug-format=option1[,option2,...] allows one to add
2228 additional text to each output. At present only timestamps
2229 are supported: --debug-format=timestamps.
2230 Timestamps can also be turned on with the
2231 "monitor set debug-format timestamps" command from GDB.
2233 * The 'record instruction-history' command now starts counting instructions
2234 at one. This also affects the instruction ranges reported by the
2235 'record function-call-history' command when given the /i modifier.
2237 * The command 'record function-call-history' supports a new modifier '/c' to
2238 indent the function names based on their call stack depth.
2239 The fields for the '/i' and '/l' modifier have been reordered.
2240 The source line range is now prefixed with 'at'.
2241 The instruction range is now prefixed with 'inst'.
2242 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2243 "record instruction-history" and "list" commands.
2245 * The ranges given as arguments to the 'record function-call-history' and
2246 'record instruction-history' commands are now inclusive.
2248 * The btrace record target now supports the 'record goto' command.
2249 For locations inside the execution trace, the back trace is computed
2250 based on the information stored in the execution trace.
2252 * The btrace record target supports limited reverse execution and replay.
2253 The target does not record data and therefore does not allow reading
2254 memory or registers.
2256 * The "catch syscall" command now works on s390*-linux* targets.
2258 * The "compare-sections" command is no longer specific to target
2259 remote. It now works with all targets.
2261 * All native targets are now consistently called "native".
2262 Consequently, the "target child", "target GNU", "target djgpp",
2263 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2264 commands have been replaced with "target native". The QNX/NTO port
2265 leaves the "procfs" target in place and adds a "native" target for
2266 consistency with other ports. The impact on users should be minimal
2267 as these commands previously either throwed an error, or were
2268 no-ops. The target's name is visible in the output of the following
2269 commands: "help target", "info target", "info files", "maint print
2272 * The "target native" command now connects to the native target. This
2273 can be used to launch native programs even when "set
2274 auto-connect-native-target" is set to off.
2276 * GDB now supports access to Intel MPX registers on GNU/Linux.
2278 * Support for Intel AVX-512 registers on GNU/Linux.
2279 Support displaying and modifying Intel AVX-512 registers
2280 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2282 * New remote packets
2284 qXfer:btrace:read's annex
2285 The qXfer:btrace:read packet supports a new annex 'delta' to read
2286 branch trace incrementally.
2290 ** Valid Python operations on gdb.Value objects representing
2291 structs/classes invoke the corresponding overloaded operators if
2293 ** New `Xmethods' feature in the Python API. Xmethods are
2294 additional methods or replacements for existing methods of a C++
2295 class. This feature is useful for those cases where a method
2296 defined in C++ source code could be inlined or optimized out by
2297 the compiler, making it unavailable to GDB.
2300 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2302 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2303 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2304 its alias "share", instead.
2306 * The commands "set remotebaud" and "show remotebaud" are no longer
2307 supported. Use "set serial baud" and "show serial baud" (respectively)
2312 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2313 target-async". The latter is left as a deprecated alias of the
2314 former for backward compatibility. If the target supports it,
2315 CLI background execution commands are now always possible by
2316 default, independently of whether the frontend stated a
2317 preference for asynchronous execution with "-gdb-set mi-async".
2318 Previously "-gdb-set target-async off" affected both MI execution
2319 commands and CLI execution commands.
2321 *** Changes in GDB 7.7
2323 * Improved support for process record-replay and reverse debugging on
2324 arm*-linux* targets. Support for thumb32 and syscall instruction
2325 recording has been added.
2327 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2329 * GDB now supports Fission DWP file format version 2.
2330 http://gcc.gnu.org/wiki/DebugFission
2332 * New convenience function "$_isvoid", to check whether an expression
2333 is void. A void expression is an expression where the type of the
2334 result is "void". For example, some convenience variables may be
2335 "void" when evaluated (e.g., "$_exitcode" before the execution of
2336 the program being debugged; or an undefined convenience variable).
2337 Another example, when calling a function whose return type is
2340 * The "maintenance print objfiles" command now takes an optional regexp.
2342 * The "catch syscall" command now works on arm*-linux* targets.
2344 * GDB now consistently shows "<not saved>" when printing values of
2345 registers the debug info indicates have not been saved in the frame
2346 and there's nowhere to retrieve them from
2347 (callee-saved/call-clobbered registers):
2352 (gdb) info registers rax
2355 Before, the former would print "<optimized out>", and the latter
2356 "*value not available*".
2358 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2363 ** Frame filters and frame decorators have been added.
2364 ** Temporary breakpoints are now supported.
2365 ** Line tables representation has been added.
2366 ** New attribute 'parent_type' for gdb.Field objects.
2367 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2368 ** New attribute 'name' for gdb.Type objects.
2372 Nios II ELF nios2*-*-elf
2373 Nios II GNU/Linux nios2*-*-linux
2374 Texas Instruments MSP430 msp430*-*-elf
2376 * Removed native configurations
2378 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2379 been removed. ELF variants of these configurations are kept supported.
2381 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2382 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2383 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2384 i[34567]86-*-openbsd3.[0-3]
2385 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2386 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2387 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2391 Like "catch throw", but catches a re-thrown exception.
2392 maint check-psymtabs
2393 Renamed from old "maint check-symtabs".
2395 Perform consistency checks on symtabs.
2396 maint expand-symtabs
2397 Expand symtabs matching an optional regexp.
2400 Display the details of GDB configure-time options.
2402 maint set|show per-command
2403 maint set|show per-command space
2404 maint set|show per-command time
2405 maint set|show per-command symtab
2406 Enable display of per-command gdb resource usage.
2408 remove-symbol-file FILENAME
2409 remove-symbol-file -a ADDRESS
2410 Remove a symbol file added via add-symbol-file. The file to remove
2411 can be identified by its filename or by an address that lies within
2412 the boundaries of this symbol file in memory.
2415 info exceptions REGEXP
2416 Display the list of Ada exceptions defined in the program being
2417 debugged. If provided, only the exceptions whose names match REGEXP
2422 set debug symfile off|on
2424 Control display of debugging info regarding reading symbol files and
2425 symbol tables within those files
2427 set print raw frame-arguments
2428 show print raw frame-arguments
2429 Set/show whether to print frame arguments in raw mode,
2430 disregarding any defined pretty-printers.
2432 set remote trace-status-packet
2433 show remote trace-status-packet
2434 Set/show the use of remote protocol qTStatus packet.
2438 Control display of debugging messages related to Nios II targets.
2442 Control whether target-assisted range stepping is enabled.
2444 set startup-with-shell
2445 show startup-with-shell
2446 Specifies whether Unix child processes are started via a shell or
2451 Use the target memory cache for accesses to the code segment. This
2452 improves performance of remote debugging (particularly disassembly).
2454 * You can now use a literal value 'unlimited' for options that
2455 interpret 0 or -1 as meaning "unlimited". E.g., "set
2456 trace-buffer-size unlimited" is now an alias for "set
2457 trace-buffer-size -1" and "set height unlimited" is now an alias for
2460 * The "set debug symtab-create" debugging option of GDB has been changed to
2461 accept a verbosity level. 0 means "off", 1 provides basic debugging
2462 output, and values of 2 or greater provides more verbose output.
2464 * New command-line options
2466 Display the details of GDB configure-time options.
2468 * The command 'tsave' can now support new option '-ctf' to save trace
2469 buffer in Common Trace Format.
2471 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2474 * GDB now implements the C++ 'typeid' operator.
2476 * The new convenience variable $_exception holds the exception being
2477 thrown or caught at an exception-related catchpoint.
2479 * The exception-related catchpoints, like "catch throw", now accept a
2480 regular expression which can be used to filter exceptions by type.
2482 * The new convenience variable $_exitsignal is automatically set to
2483 the terminating signal number when the program being debugged dies
2484 due to an uncaught signal.
2488 ** All MI commands now accept an optional "--language" option.
2489 Support for this feature can be verified by using the "-list-features"
2490 command, which should contain "language-option".
2492 ** The new command -info-gdb-mi-command allows the user to determine
2493 whether a GDB/MI command is supported or not.
2495 ** The "^error" result record returned when trying to execute an undefined
2496 GDB/MI command now provides a variable named "code" whose content is the
2497 "undefined-command" error code. Support for this feature can be verified
2498 by using the "-list-features" command, which should contain
2499 "undefined-command-error-code".
2501 ** The -trace-save MI command can optionally save trace buffer in Common
2504 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2506 ** The command -data-list-register-values now accepts an optional
2507 "--skip-unavailable" option. When used, only the available registers
2510 ** The new command -trace-frame-collected dumps collected variables,
2511 computed expressions, tvars, memory and registers in a traceframe.
2513 ** The commands -stack-list-locals, -stack-list-arguments and
2514 -stack-list-variables now accept an option "--skip-unavailable".
2515 When used, only the available locals or arguments are displayed.
2517 ** The -exec-run command now accepts an optional "--start" option.
2518 When used, the command follows the same semantics as the "start"
2519 command, stopping the program's execution at the start of its
2520 main subprogram. Support for this feature can be verified using
2521 the "-list-features" command, which should contain
2522 "exec-run-start-option".
2524 ** The new commands -catch-assert and -catch-exceptions insert
2525 catchpoints stopping the program when Ada exceptions are raised.
2527 ** The new command -info-ada-exceptions provides the equivalent of
2528 the new "info exceptions" command.
2530 * New system-wide configuration scripts
2531 A GDB installation now provides scripts suitable for use as system-wide
2532 configuration scripts for the following systems:
2536 * GDB now supports target-assigned range stepping with remote targets.
2537 This improves the performance of stepping source lines by reducing
2538 the number of control packets from/to GDB. See "New remote packets"
2541 * GDB now understands the element 'tvar' in the XML traceframe info.
2542 It has the id of the collected trace state variables.
2544 * On S/390 targets that provide the transactional-execution feature,
2545 the program interruption transaction diagnostic block (TDB) is now
2546 represented as a number of additional "registers" in GDB.
2548 * New remote packets
2552 The vCont packet supports a new 'r' action, that tells the remote
2553 stub to step through an address range itself, without GDB
2554 involvemement at each single-step.
2556 qXfer:libraries-svr4:read's annex
2557 The previously unused annex of the qXfer:libraries-svr4:read packet
2558 is now used to support passing an argument list. The remote stub
2559 reports support for this argument list to GDB's qSupported query.
2560 The defined arguments are "start" and "prev", used to reduce work
2561 necessary for library list updating, resulting in significant
2564 * New features in the GDB remote stub, GDBserver
2566 ** GDBserver now supports target-assisted range stepping. Currently
2567 enabled on x86/x86_64 GNU/Linux targets.
2569 ** GDBserver now adds element 'tvar' in the XML in the reply to
2570 'qXfer:traceframe-info:read'. It has the id of the collected
2571 trace state variables.
2573 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2576 * New 'z' formatter for printing and examining memory, this displays the
2577 value as hexadecimal zero padded on the left to the size of the type.
2579 * GDB can now use Windows x64 unwinding data.
2581 * The "set remotebaud" command has been replaced by "set serial baud".
2582 Similarly, "show remotebaud" has been replaced by "show serial baud".
2583 The "set remotebaud" and "show remotebaud" commands are still available
2584 to provide backward compatibility with older versions of GDB.
2586 *** Changes in GDB 7.6
2588 * Target record has been renamed to record-full.
2589 Record/replay is now enabled with the "record full" command.
2590 This also affects settings that are associated with full record/replay
2591 that have been moved from "set/show record" to "set/show record full":
2593 set|show record full insn-number-max
2594 set|show record full stop-at-limit
2595 set|show record full memory-query
2597 * A new record target "record-btrace" has been added. The new target
2598 uses hardware support to record the control-flow of a process. It
2599 does not support replaying the execution, but it implements the
2600 below new commands for investigating the recorded execution log.
2601 This new recording method can be enabled using:
2605 The "record-btrace" target is only available on Intel Atom processors
2606 and requires a Linux kernel 2.6.32 or later.
2608 * Two new commands have been added for record/replay to give information
2609 about the recorded execution without having to replay the execution.
2610 The commands are only supported by "record btrace".
2612 record instruction-history prints the execution history at
2613 instruction granularity
2615 record function-call-history prints the execution history at
2616 function granularity
2618 * New native configurations
2620 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2621 FreeBSD/powerpc powerpc*-*-freebsd
2622 x86_64/Cygwin x86_64-*-cygwin*
2623 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2627 ARM AArch64 aarch64*-*-elf
2628 ARM AArch64 GNU/Linux aarch64*-*-linux
2629 Lynx 178 PowerPC powerpc-*-lynx*178
2630 x86_64/Cygwin x86_64-*-cygwin*
2631 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2633 * If the configured location of system.gdbinit file (as given by the
2634 --with-system-gdbinit option at configure time) is in the
2635 data-directory (as specified by --with-gdb-datadir at configure
2636 time) or in one of its subdirectories, then GDB will look for the
2637 system-wide init file in the directory specified by the
2638 --data-directory command-line option.
2640 * New command line options:
2642 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2643 other initialization files, unlike -nx which disables all of them.
2645 * Removed command line options
2647 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2650 * The 'ptype' and 'whatis' commands now accept an argument to control
2653 * 'info proc' now works on some core files.
2657 ** Vectors can be created with gdb.Type.vector.
2659 ** Python's atexit.register now works in GDB.
2661 ** Types can be pretty-printed via a Python API.
2663 ** Python 3 is now supported (in addition to Python 2.4 or later)
2665 ** New class gdb.Architecture exposes GDB's internal representation
2666 of architecture in the Python API.
2668 ** New method Frame.architecture returns the gdb.Architecture object
2669 corresponding to the frame's architecture.
2671 * New Python-based convenience functions:
2673 ** $_memeq(buf1, buf2, length)
2674 ** $_streq(str1, str2)
2676 ** $_regex(str, regex)
2678 * The 'cd' command now defaults to using '~' (the home directory) if not
2681 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2682 default for GCC since November 2000.
2684 * The command 'forward-search' can now be abbreviated as 'fo'.
2686 * The command 'info tracepoints' can now display 'installed on target'
2687 or 'not installed on target' for each non-pending location of tracepoint.
2689 * New configure options
2691 --enable-libmcheck/--disable-libmcheck
2692 By default, development versions are built with -lmcheck on hosts
2693 that support it, in order to help track memory corruption issues.
2694 Release versions, on the other hand, are built without -lmcheck
2695 by default. The --enable-libmcheck/--disable-libmcheck configure
2696 options allow the user to override that default.
2697 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2698 This configure option allows the user to build GDB with
2699 libbabeltrace using which GDB can read Common Trace Format data.
2701 * New commands (for set/show, see "New options" below)
2704 Catch signals. This is similar to "handle", but allows commands and
2705 conditions to be attached.
2708 List the BFDs known to GDB.
2710 python-interactive [command]
2712 Start a Python interactive prompt, or evaluate the optional command
2713 and print the result of expressions.
2716 "py" is a new alias for "python".
2718 enable type-printer [name]...
2719 disable type-printer [name]...
2720 Enable or disable type printers.
2724 ** For the Renesas Super-H architecture, the "regs" command has been removed
2725 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2730 set print type methods (on|off)
2731 show print type methods
2732 Control whether method declarations are displayed by "ptype".
2733 The default is to show them.
2735 set print type typedefs (on|off)
2736 show print type typedefs
2737 Control whether typedef definitions are displayed by "ptype".
2738 The default is to show them.
2740 set filename-display basename|relative|absolute
2741 show filename-display
2742 Control the way in which filenames is displayed.
2743 The default is "relative", which preserves previous behavior.
2745 set trace-buffer-size
2746 show trace-buffer-size
2747 Request target to change the size of trace buffer.
2749 set remote trace-buffer-size-packet auto|on|off
2750 show remote trace-buffer-size-packet
2751 Control the use of the remote protocol `QTBuffer:size' packet.
2755 Control display of debugging messages related to ARM AArch64.
2758 set debug coff-pe-read
2759 show debug coff-pe-read
2760 Control display of debugging messages related to reading of COFF/PE
2765 Control display of debugging messages related to Mach-O symbols
2768 set debug notification
2769 show debug notification
2770 Control display of debugging info for async remote notification.
2774 ** Command parameter changes are now notified using new async record
2775 "=cmd-param-changed".
2776 ** Trace frame changes caused by command "tfind" are now notified using
2777 new async record "=traceframe-changed".
2778 ** The creation, deletion and modification of trace state variables
2779 are now notified using new async records "=tsv-created",
2780 "=tsv-deleted" and "=tsv-modified".
2781 ** The start and stop of process record are now notified using new
2782 async record "=record-started" and "=record-stopped".
2783 ** Memory changes are now notified using new async record
2785 ** The data-disassemble command response will include a "fullname" field
2786 containing the absolute file name when source has been requested.
2787 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2788 command, to allow pattern filling of memory areas.
2789 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2790 library load/unload events.
2791 ** The response to breakpoint commands and breakpoint async records
2792 includes an "installed" field containing a boolean state about each
2793 non-pending tracepoint location is whether installed on target or not.
2794 ** Output of the "-trace-status" command includes a "trace-file" field
2795 containing the name of the trace file being examined. This field is
2796 optional, and only present when examining a trace file.
2797 ** The "fullname" field is now always present along with the "file" field,
2798 even if the file cannot be found by GDB.
2800 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2801 You must have the LZMA library available when configuring GDB for this
2802 feature to be enabled. For more information, see:
2803 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2805 * New remote packets
2808 Set the size of trace buffer. The remote stub reports support for this
2809 packet to gdb's qSupported query.
2812 Enable Branch Trace Store (BTS)-based branch tracing for the current
2813 thread. The remote stub reports support for this packet to gdb's
2817 Disable branch tracing for the current thread. The remote stub reports
2818 support for this packet to gdb's qSupported query.
2821 Read the traced branches for the current thread. The remote stub
2822 reports support for this packet to gdb's qSupported query.
2824 *** Changes in GDB 7.5
2826 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2827 for more x32 ABI info.
2829 * GDB now supports access to MIPS DSP registers on Linux targets.
2831 * GDB now supports debugging microMIPS binaries.
2833 * The "info os" command on GNU/Linux can now display information on
2834 several new classes of objects managed by the operating system:
2835 "info os procgroups" lists process groups
2836 "info os files" lists file descriptors
2837 "info os sockets" lists internet-domain sockets
2838 "info os shm" lists shared-memory regions
2839 "info os semaphores" lists semaphores
2840 "info os msg" lists message queues
2841 "info os modules" lists loaded kernel modules
2843 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2844 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2845 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2846 options and inspect the probe arguments using the new $_probe_arg family
2847 of convenience variables. You can obtain more information about SystemTap
2848 in <http://sourceware.org/systemtap/>.
2850 * GDB now supports reversible debugging on ARM, it allows you to
2851 debug basic ARM and THUMB instructions, and provides
2852 record/replay support.
2854 * The option "symbol-reloading" has been deleted as it is no longer used.
2858 ** GDB commands implemented in Python can now be put in command class
2861 ** The "maint set python print-stack on|off" is now deleted.
2863 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2864 apply "flag enum"-style pretty-printing to any enum.
2866 ** gdb.lookup_symbol can now work when there is no current frame.
2868 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2869 the source at which the symbol was defined.
2871 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2872 method 'value'. The former indicates whether the symbol needs a
2873 frame in order to compute its value, and the latter computes the
2876 ** A new method 'referenced_value' on gdb.Value objects which can
2877 dereference pointer as well as C++ reference values.
2879 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2880 which return the global and static blocks (as gdb.Block objects),
2881 of the underlying symbol table, respectively.
2883 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2884 object associated with a PC value.
2886 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2887 of the address range occupied by code for the current source line.
2889 * Go language support.
2890 GDB now supports debugging programs written in the Go programming
2893 * GDBserver now supports stdio connections.
2894 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2896 * The binary "gdbtui" can no longer be built or installed.
2897 Use "gdb -tui" instead.
2899 * GDB will now print "flag" enums specially. A flag enum is one where
2900 all the enumerator values have no bits in common when pairwise
2901 "and"ed. When printing a value whose type is a flag enum, GDB will
2902 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2903 (gdb) print (enum E) 3
2906 * The filename part of a linespec will now match trailing components
2907 of a source file name. For example, "break gcc/expr.c:1000" will
2908 now set a breakpoint in build/gcc/expr.c, but not
2909 build/libcpp/expr.c.
2911 * The "info proc" and "generate-core-file" commands will now also
2912 work on remote targets connected to GDBserver on Linux.
2914 * The command "info catch" has been removed. It has been disabled
2915 since December 2007.
2917 * The "catch exception" and "catch assert" commands now accept
2918 a condition at the end of the command, much like the "break"
2919 command does. For instance:
2921 (gdb) catch exception Constraint_Error if Barrier = True
2923 Previously, it was possible to add a condition to such catchpoints,
2924 but it had to be done as a second step, after the catchpoint had been
2925 created, using the "condition" command.
2927 * The "info static-tracepoint-marker" command will now also work on
2928 native Linux targets with in-process agent.
2930 * GDB can now set breakpoints on inlined functions.
2932 * The .gdb_index section has been updated to include symbols for
2933 inlined functions. GDB will ignore older .gdb_index sections by
2934 default, which could cause symbol files to be loaded more slowly
2935 until their .gdb_index sections can be recreated. The new command
2936 "set use-deprecated-index-sections on" will cause GDB to use any older
2937 .gdb_index sections it finds. This will restore performance, but the
2938 ability to set breakpoints on inlined functions will be lost in symbol
2939 files with older .gdb_index sections.
2941 The .gdb_index section has also been updated to record more information
2942 about each symbol. This speeds up the "info variables", "info functions"
2943 and "info types" commands when used with programs having the .gdb_index
2944 section, as well as speeding up debugging with shared libraries using
2945 the .gdb_index section.
2947 * Ada support for GDB/MI Variable Objects has been added.
2949 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2954 ** New command -info-os is the MI equivalent of "info os".
2956 ** Output logs ("set logging" and related) now include MI output.
2960 ** "set use-deprecated-index-sections on|off"
2961 "show use-deprecated-index-sections on|off"
2962 Controls the use of deprecated .gdb_index sections.
2964 ** "catch load" and "catch unload" can be used to stop when a shared
2965 library is loaded or unloaded, respectively.
2967 ** "enable count" can be used to auto-disable a breakpoint after
2970 ** "info vtbl" can be used to show the virtual method tables for
2971 C++ and Java objects.
2973 ** "explore" and its sub commands "explore value" and "explore type"
2974 can be used to recursively explore values and types of
2975 expressions. These commands are available only if GDB is
2976 configured with '--with-python'.
2978 ** "info auto-load" shows status of all kinds of auto-loaded files,
2979 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2980 sequences of commands files, "info auto-load python-scripts"
2981 shows status of auto-loading Python script files,
2982 "info auto-load local-gdbinit" shows status of loading init file
2983 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2984 status of inferior specific thread debugging shared library loading.
2986 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2987 and "show auto-load-scripts" commands have been deprecated, use their
2988 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2989 and "show auto-load python-scripts" counterparts instead.
2991 ** "dprintf location,format,args..." creates a dynamic printf, which
2992 is basically a breakpoint that does a printf and immediately
2993 resumes your program's execution, so it is like a printf that you
2994 can insert dynamically at runtime instead of at compiletime.
2996 ** "set print symbol"
2998 Controls whether GDB attempts to display the symbol, if any,
2999 corresponding to addresses it prints. This defaults to "on", but
3000 you can set it to "off" to restore GDB's previous behavior.
3002 * Deprecated commands
3004 ** For the Renesas Super-H architecture, the "regs" command has been
3005 deprecated, and "info all-registers" should be used instead.
3009 Renesas RL78 rl78-*-elf
3010 HP OpenVMS ia64 ia64-hp-openvms*
3012 * GDBserver supports evaluation of breakpoint conditions. When
3013 support is advertised by GDBserver, GDB may be told to send the
3014 breakpoint conditions in bytecode form to GDBserver. GDBserver
3015 will only report the breakpoint trigger to GDB when its condition
3020 set mips compression
3021 show mips compression
3022 Select the compressed ISA encoding used in functions that have no symbol
3023 information available. The encoding can be set to either of:
3026 and is updated automatically from ELF file flags if available.
3028 set breakpoint condition-evaluation
3029 show breakpoint condition-evaluation
3030 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3031 GDBserver ("target"). Default option "auto" chooses the most efficient
3033 This option can improve debugger efficiency depending on the speed of the
3037 Disable auto-loading globally.
3040 Show auto-loading setting of all kinds of auto-loaded files.
3042 set auto-load gdb-scripts on|off
3043 show auto-load gdb-scripts
3044 Control auto-loading of GDB canned sequences of commands files.
3046 set auto-load python-scripts on|off
3047 show auto-load python-scripts
3048 Control auto-loading of Python script files.
3050 set auto-load local-gdbinit on|off
3051 show auto-load local-gdbinit
3052 Control loading of init file (.gdbinit) from current directory.
3054 set auto-load libthread-db on|off
3055 show auto-load libthread-db
3056 Control auto-loading of inferior specific thread debugging shared library.
3058 set auto-load scripts-directory <dir1>[:<dir2>...]
3059 show auto-load scripts-directory
3060 Set a list of directories from which to load auto-loaded scripts.
3061 Automatically loaded Python scripts and GDB scripts are located in one
3062 of the directories listed by this option.
3063 The delimiter (':' above) may differ according to the host platform.
3065 set auto-load safe-path <dir1>[:<dir2>...]
3066 show auto-load safe-path
3067 Set a list of directories from which it is safe to auto-load files.
3068 The delimiter (':' above) may differ according to the host platform.
3070 set debug auto-load on|off
3071 show debug auto-load
3072 Control display of debugging info for auto-loading the files above.
3074 set dprintf-style gdb|call|agent
3076 Control the way in which a dynamic printf is performed; "gdb"
3077 requests a GDB printf command, while "call" causes dprintf to call a
3078 function in the inferior. "agent" requests that the target agent
3079 (such as GDBserver) do the printing.
3081 set dprintf-function <expr>
3082 show dprintf-function
3083 set dprintf-channel <expr>
3084 show dprintf-channel
3085 Set the function and optional first argument to the call when using
3086 the "call" style of dynamic printf.
3088 set disconnected-dprintf on|off
3089 show disconnected-dprintf
3090 Control whether agent-style dynamic printfs continue to be in effect
3091 after GDB disconnects.
3093 * New configure options
3095 --with-auto-load-dir
3096 Configure default value for the 'set auto-load scripts-directory'
3097 setting above. It defaults to '$debugdir:$datadir/auto-load',
3098 $debugdir representing global debugging info directories (available
3099 via 'show debug-file-directory') and $datadir representing GDB's data
3100 directory (available via 'show data-directory').
3102 --with-auto-load-safe-path
3103 Configure default value for the 'set auto-load safe-path' setting
3104 above. It defaults to the --with-auto-load-dir setting.
3106 --without-auto-load-safe-path
3107 Set 'set auto-load safe-path' to '/', effectively disabling this
3110 * New remote packets
3112 z0/z1 conditional breakpoints extension
3114 The z0/z1 breakpoint insertion packets have been extended to carry
3115 a list of conditional expressions over to the remote stub depending on the
3116 condition evaluation mode. The use of this extension can be controlled
3117 via the "set remote conditional-breakpoints-packet" command.
3121 Specify the signals which the remote stub may pass to the debugged
3122 program without GDB involvement.
3124 * New command line options
3126 --init-command=FILE, -ix Like --command, -x but execute it
3127 before loading inferior.
3128 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3129 execute it before loading inferior.
3131 *** Changes in GDB 7.4
3133 * GDB now handles ambiguous linespecs more consistently; the existing
3134 FILE:LINE support has been expanded to other types of linespecs. A
3135 breakpoint will now be set on all matching locations in all
3136 inferiors, and locations will be added or removed according to
3139 * GDB now allows you to skip uninteresting functions and files when
3140 stepping with the "skip function" and "skip file" commands.
3142 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3143 and "show remote hardware-watchpoint-length-limit". These allows to
3144 set or show the maximum length limit (in bytes) of a remote
3145 target hardware watchpoint.
3147 This allows e.g. to use "unlimited" hardware watchpoints with the
3148 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3149 watchpoints are slower than real hardware watchpoints but are
3150 significantly faster than gdb software watchpoints.
3154 ** The register_pretty_printer function in module gdb.printing now takes
3155 an optional `replace' argument. If True, the new printer replaces any
3158 ** The "maint set python print-stack on|off" command has been
3159 deprecated and will be deleted in GDB 7.5.
3160 A new command: "set python print-stack none|full|message" has
3161 replaced it. Additionally, the default for "print-stack" is
3162 now "message", which just prints the error message without
3165 ** A prompt substitution hook (prompt_hook) is now available to the
3168 ** A new Python module, gdb.prompt has been added to the GDB Python
3169 modules library. This module provides functionality for
3170 escape sequences in prompts (used by set/show
3171 extended-prompt). These escape sequences are replaced by their
3172 corresponding value.
3174 ** Python commands and convenience-functions located in
3175 'data-directory'/python/gdb/command and
3176 'data-directory'/python/gdb/function are now automatically loaded
3179 ** Blocks now provide four new attributes. global_block and
3180 static_block will return the global and static blocks
3181 respectively. is_static and is_global are boolean attributes
3182 that indicate if the block is one of those two types.
3184 ** Symbols now provide the "type" attribute, the type of the symbol.
3186 ** The "gdb.breakpoint" function has been deprecated in favor of
3189 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3190 of a function. This class is based on the "finish" command
3191 available in the CLI.
3193 ** Type objects for struct and union types now allow access to
3194 the fields using standard Python dictionary (mapping) methods.
3195 For example, "some_type['myfield']" now works, as does
3196 "some_type.items()".
3198 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3201 ** A new function, "deep_items" has been added to the gdb.types
3202 module in the GDB Python modules library. This function returns
3203 an iterator over the fields of a struct or union type. Unlike
3204 the standard Python "iteritems" method, it will recursively traverse
3205 any anonymous fields.
3209 ** "*stopped" events can report several new "reason"s, such as
3212 ** Breakpoint changes are now notified using new async records, like
3213 "=breakpoint-modified".
3215 ** New command -ada-task-info.
3217 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3218 $sdir specifies the default system locations of shared libraries.
3219 $pdir specifies the directory where the libpthread used by the application
3222 GDB no longer looks in $sdir and $pdir after it has searched the directories
3223 mentioned in libthread-db-search-path. If you want to search those
3224 directories, they must be specified in libthread-db-search-path.
3225 The default value of libthread-db-search-path on GNU/Linux and Solaris
3226 systems is now "$sdir:$pdir".
3228 $pdir is not supported by gdbserver, it is currently ignored.
3229 $sdir is supported by gdbserver.
3231 * New configure option --with-iconv-bin.
3232 When using the internationalization support like the one in the GNU C
3233 library, GDB will invoke the "iconv" program to get a list of supported
3234 character sets. If this program lives in a non-standard location, one can
3235 use this option to specify where to find it.
3237 * When natively debugging programs on PowerPC BookE processors running
3238 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3239 watchpoints, which specify a mask in addition to an address to watch.
3240 The mask specifies that some bits of an address (the bits which are
3241 reset in the mask) should be ignored when matching the address accessed
3242 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3243 section in the user manual for more details.
3245 * The new option --once causes GDBserver to stop listening for connections once
3246 the first connection is made. The listening port used by GDBserver will
3247 become available after that.
3249 * New commands "info macros" and "alias" have been added.
3251 * New function parameters suffix @entry specifies value of function parameter
3252 at the time the function got called. Entry values are available only since
3258 "!" is now an alias of the "shell" command.
3259 Note that no space is needed between "!" and SHELL COMMAND.
3263 watch EXPRESSION mask MASK_VALUE
3264 The watch command now supports the mask argument which allows creation
3265 of masked watchpoints, if the current architecture supports this feature.
3267 info auto-load-scripts [REGEXP]
3268 This command was formerly named "maintenance print section-scripts".
3269 It is now generally useful and is no longer a maintenance-only command.
3271 info macro [-all] [--] MACRO
3272 The info macro command has new options `-all' and `--'. The first for
3273 printing all definitions of a macro. The second for explicitly specifying
3274 the end of arguments and the beginning of the macro name in case the macro
3275 name starts with a hyphen.
3277 collect[/s] EXPRESSIONS
3278 The tracepoint collect command now takes an optional modifier "/s"
3279 that directs it to dereference pointer-to-character types and
3280 collect the bytes of memory up to a zero byte. The behavior is
3281 similar to what you see when you use the regular print command on a
3282 string. An optional integer following the "/s" sets a bound on the
3283 number of bytes that will be collected.
3286 The trace start command now interprets any supplied arguments as a
3287 note to be recorded with the trace run, with an effect similar to
3288 setting the variable trace-notes.
3291 The trace stop command now interprets any arguments as a note to be
3292 mentioned along with the tstatus report that the trace was stopped
3293 with a command. The effect is similar to setting the variable
3296 * Tracepoints can now be enabled and disabled at any time after a trace
3297 experiment has been started using the standard "enable" and "disable"
3298 commands. It is now possible to start a trace experiment with no enabled
3299 tracepoints; GDB will display a warning, but will allow the experiment to
3300 begin, assuming that tracepoints will be enabled as needed while the trace
3303 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3304 locations with 4-byte instructions, when they were previously
3305 limited to locations with instructions of 5 bytes or longer.
3309 set debug dwarf2-read
3310 show debug dwarf2-read
3311 Turns on or off display of debugging messages related to reading
3312 DWARF debug info. The default is off.
3314 set debug symtab-create
3315 show debug symtab-create
3316 Turns on or off display of debugging messages related to symbol table
3317 creation. The default is off.
3320 show extended-prompt
3321 Set the GDB prompt, and allow escape sequences to be inserted to
3322 display miscellaneous information (see 'help set extended-prompt'
3323 for the list of sequences). This prompt (and any information
3324 accessed through the escape sequences) is updated every time the
3325 prompt is displayed.
3327 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3328 show print entry-values
3329 Set printing of frame argument values at function entry. In some cases
3330 GDB can determine the value of function argument which was passed by the
3331 function caller, even if the value was modified inside the called function.
3333 set debug entry-values
3334 show debug entry-values
3335 Control display of debugging info for determining frame argument values at
3336 function entry and virtual tail call frames.
3338 set basenames-may-differ
3339 show basenames-may-differ
3340 Set whether a source file may have multiple base names.
3341 (A "base name" is the name of a file with the directory part removed.
3342 Example: The base name of "/home/user/hello.c" is "hello.c".)
3343 If set, GDB will canonicalize file names (e.g., expand symlinks)
3344 before comparing them. Canonicalization is an expensive operation,
3345 but it allows the same file be known by more than one base name.
3346 If not set (the default), all source files are assumed to have just
3347 one base name, and gdb will do file name comparisons more efficiently.
3353 Set a user name and notes for the current and any future trace runs.
3354 This is useful for long-running and/or disconnected traces, to
3355 inform others (or yourself) as to who is running the trace, supply
3356 contact information, or otherwise explain what is going on.
3358 set trace-stop-notes
3359 show trace-stop-notes
3360 Set a note attached to the trace run, that is displayed when the
3361 trace has been stopped by a tstop command. This is useful for
3362 instance as an explanation, if you are stopping a trace run that was
3363 started by someone else.
3365 * New remote packets
3369 Dynamically enable a tracepoint in a started trace experiment.
3373 Dynamically disable a tracepoint in a started trace experiment.
3377 Set the user and notes of the trace run.
3381 Query the current status of a tracepoint.
3385 Query the minimum length of instruction at which a fast tracepoint may
3388 * Dcache size (number of lines) and line-size are now runtime-configurable
3389 via "set dcache line" and "set dcache line-size" commands.
3393 Texas Instruments TMS320C6x tic6x-*-*
3397 Renesas RL78 rl78-*-elf
3399 *** Changes in GDB 7.3.1
3401 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3403 *** Changes in GDB 7.3
3405 * GDB has a new command: "thread find [REGEXP]".
3406 It finds the thread id whose name, target id, or thread extra info
3407 matches the given regular expression.
3409 * The "catch syscall" command now works on mips*-linux* targets.
3411 * The -data-disassemble MI command now supports modes 2 and 3 for
3412 dumping the instruction opcodes.
3414 * New command line options
3416 -data-directory DIR Specify DIR as the "data-directory".
3417 This is mostly for testing purposes.
3419 * The "maint set python auto-load on|off" command has been renamed to
3420 "set auto-load-scripts on|off".
3422 * GDB has a new command: "set directories".
3423 It is like the "dir" command except that it replaces the
3424 source path list instead of augmenting it.
3426 * GDB now understands thread names.
3428 On GNU/Linux, "info threads" will display the thread name as set by
3429 prctl or pthread_setname_np.
3431 There is also a new command, "thread name", which can be used to
3432 assign a name internally for GDB to display.
3435 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3436 has been integrated into GDB.
3440 ** The function gdb.Write now accepts an optional keyword 'stream'.
3441 This keyword, when provided, will direct the output to either
3442 stdout, stderr, or GDB's logging output.
3444 ** Parameters can now be be sub-classed in Python, and in particular
3445 you may implement the get_set_doc and get_show_doc functions.
3446 This improves how Parameter set/show documentation is processed
3447 and allows for more dynamic content.
3449 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3450 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3451 have an is_valid method.
3453 ** Breakpoints can now be sub-classed in Python, and in particular
3454 you may implement a 'stop' function that is executed each time
3455 the inferior reaches that breakpoint.
3457 ** New function gdb.lookup_global_symbol looks up a global symbol.
3459 ** GDB values in Python are now callable if the value represents a
3460 function. For example, if 'some_value' represents a function that
3461 takes two integer parameters and returns a value, you can call
3462 that function like so:
3464 result = some_value (10,20)
3466 ** Module gdb.types has been added.
3467 It contains a collection of utilities for working with gdb.Types objects:
3468 get_basic_type, has_field, make_enum_dict.
3470 ** Module gdb.printing has been added.
3471 It contains utilities for writing and registering pretty-printers.
3472 New classes: PrettyPrinter, SubPrettyPrinter,
3473 RegexpCollectionPrettyPrinter.
3474 New function: register_pretty_printer.
3476 ** New commands "info pretty-printers", "enable pretty-printer" and
3477 "disable pretty-printer" have been added.
3479 ** gdb.parameter("directories") is now available.
3481 ** New function gdb.newest_frame returns the newest frame in the
3484 ** The gdb.InferiorThread class has a new "name" attribute. This
3485 holds the thread's name.
3487 ** Python Support for Inferior events.
3488 Python scripts can add observers to be notified of events
3489 occurring in the process being debugged.
3490 The following events are currently supported:
3491 - gdb.events.cont Continue event.
3492 - gdb.events.exited Inferior exited event.
3493 - gdb.events.stop Signal received, and Breakpoint hit events.
3497 ** GDB now puts template parameters in scope when debugging in an
3498 instantiation. For example, if you have:
3500 template<int X> int func (void) { return X; }
3502 then if you step into func<5>, "print X" will show "5". This
3503 feature requires proper debuginfo support from the compiler; it
3504 was added to GCC 4.5.
3506 ** The motion commands "next", "finish", "until", and "advance" now
3507 work better when exceptions are thrown. In particular, GDB will
3508 no longer lose control of the inferior; instead, the GDB will
3509 stop the inferior at the point at which the exception is caught.
3510 This functionality requires a change in the exception handling
3511 code that was introduced in GCC 4.5.
3513 * GDB now follows GCC's rules on accessing volatile objects when
3514 reading or writing target state during expression evaluation.
3515 One notable difference to prior behavior is that "print x = 0"
3516 no longer generates a read of x; the value of the assignment is
3517 now always taken directly from the value being assigned.
3519 * GDB now has some support for using labels in the program's source in
3520 linespecs. For instance, you can use "advance label" to continue
3521 execution to a label.
3523 * GDB now has support for reading and writing a new .gdb_index
3524 section. This section holds a fast index of DWARF debugging
3525 information and can be used to greatly speed up GDB startup and
3526 operation. See the documentation for `save gdb-index' for details.
3528 * The "watch" command now accepts an optional "-location" argument.
3529 When used, this causes GDB to watch the memory referred to by the
3530 expression. Such a watchpoint is never deleted due to it going out
3533 * GDB now supports thread debugging of core dumps on GNU/Linux.
3535 GDB now activates thread debugging using the libthread_db library
3536 when debugging GNU/Linux core dumps, similarly to when debugging
3537 live processes. As a result, when debugging a core dump file, GDB
3538 is now able to display pthread_t ids of threads. For example, "info
3539 threads" shows the same output as when debugging the process when it
3540 was live. In earlier releases, you'd see something like this:
3543 * 1 LWP 6780 main () at main.c:10
3545 While now you see this:
3548 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3550 It is also now possible to inspect TLS variables when debugging core
3553 When debugging a core dump generated on a machine other than the one
3554 used to run GDB, you may need to point GDB at the correct
3555 libthread_db library with the "set libthread-db-search-path"
3556 command. See the user manual for more details on this command.
3558 * When natively debugging programs on PowerPC BookE processors running
3559 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3560 which stop execution of the inferior whenever it executes an instruction
3561 at any address within the specified range. See the "PowerPC Embedded"
3562 section in the user manual for more details.
3564 * New features in the GDB remote stub, GDBserver
3566 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3567 and i686 LynxOS (version 5.x).
3569 ** GDBserver is now supported on Blackfin Linux.
3571 * New native configurations
3573 ia64 HP-UX ia64-*-hpux*
3577 Analog Devices, Inc. Blackfin Processor bfin-*
3579 * Ada task switching is now supported on sparc-elf targets when
3580 debugging a program using the Ravenscar Profile. For more information,
3581 see the "Tasking Support when using the Ravenscar Profile" section
3582 in the GDB user manual.
3584 * Guile support was removed.
3586 * New features in the GNU simulator
3588 ** The --map-info flag lists all known core mappings.
3590 ** CFI flashes may be simulated via the "cfi" device.
3592 *** Changes in GDB 7.2
3594 * Shared library support for remote targets by default
3596 When GDB is configured for a generic, non-OS specific target, like
3597 for example, --target=arm-eabi or one of the many *-*-elf targets,
3598 GDB now queries remote stubs for loaded shared libraries using the
3599 `qXfer:libraries:read' packet. Previously, shared library support
3600 was always disabled for such configurations.
3604 ** Argument Dependent Lookup (ADL)
3606 In C++ ADL lookup directs function search to the namespaces of its
3607 arguments even if the namespace has not been imported.
3617 Here the compiler will search for `foo' in the namespace of 'b'
3618 and find A::foo. GDB now supports this. This construct is commonly
3619 used in the Standard Template Library for operators.
3621 ** Improved User Defined Operator Support
3623 In addition to member operators, GDB now supports lookup of operators
3624 defined in a namespace and imported with a `using' directive, operators
3625 defined in the global scope, operators imported implicitly from an
3626 anonymous namespace, and the ADL operators mentioned in the previous
3628 GDB now also supports proper overload resolution for all the previously
3629 mentioned flavors of operators.
3631 ** static const class members
3633 Printing of static const class members that are initialized in the
3634 class definition has been fixed.
3636 * Windows Thread Information Block access.
3638 On Windows targets, GDB now supports displaying the Windows Thread
3639 Information Block (TIB) structure. This structure is visible either
3640 by using the new command `info w32 thread-information-block' or, by
3641 dereferencing the new convenience variable named `$_tlb', a
3642 thread-specific pointer to the TIB. This feature is also supported
3643 when remote debugging using GDBserver.
3645 * Static tracepoints
3647 Static tracepoints are calls in the user program into a tracing
3648 library. One such library is a port of the LTTng kernel tracer to
3649 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3650 When debugging with GDBserver, GDB now supports combining the GDB
3651 tracepoint machinery with such libraries. For example: the user can
3652 use GDB to probe a static tracepoint marker (a call from the user
3653 program into the tracing library) with the new "strace" command (see
3654 "New commands" below). This creates a "static tracepoint" in the
3655 breakpoint list, that can be manipulated with the same feature set
3656 as fast and regular tracepoints. E.g., collect registers, local and
3657 global variables, collect trace state variables, and define
3658 tracepoint conditions. In addition, the user can collect extra
3659 static tracepoint marker specific data, by collecting the new
3660 $_sdata internal variable. When analyzing the trace buffer, you can
3661 inspect $_sdata like any other variable available to GDB. For more
3662 information, see the "Tracepoints" chapter in GDB user manual. New
3663 remote packets have been defined to support static tracepoints, see
3664 the "New remote packets" section below.
3666 * Better reconstruction of tracepoints after disconnected tracing
3668 GDB will attempt to download the original source form of tracepoint
3669 definitions when starting a trace run, and then will upload these
3670 upon reconnection to the target, resulting in a more accurate
3671 reconstruction of the tracepoints that are in use on the target.
3675 You can now exercise direct control over the ways that GDB can
3676 affect your program. For instance, you can disallow the setting of
3677 breakpoints, so that the program can run continuously (assuming
3678 non-stop mode). In addition, the "observer" variable is available
3679 to switch all of the different controls; in observer mode, GDB
3680 cannot affect the target's behavior at all, which is useful for
3681 tasks like diagnosing live systems in the field.
3683 * The new convenience variable $_thread holds the number of the
3686 * New remote packets
3690 Return the address of the Windows Thread Information Block of a given thread.
3694 In response to several of the tracepoint packets, the target may now
3695 also respond with a number of intermediate `qRelocInsn' request
3696 packets before the final result packet, to have GDB handle
3697 relocating an instruction to execute at a different address. This
3698 is particularly useful for stubs that support fast tracepoints. GDB
3699 reports support for this feature in the qSupported packet.
3703 List static tracepoint markers in the target program.
3707 List static tracepoint markers at a given address in the target
3710 qXfer:statictrace:read
3712 Read the static trace data collected (by a `collect $_sdata'
3713 tracepoint action). The remote stub reports support for this packet
3714 to gdb's qSupported query.
3718 Send the current settings of GDB's permission flags.
3722 Send part of the source (textual) form of a tracepoint definition,
3723 which includes location, conditional, and action list.
3725 * The source command now accepts a -s option to force searching for the
3726 script in the source search path even if the script name specifies
3729 * New features in the GDB remote stub, GDBserver
3731 - GDBserver now support tracepoints (including fast tracepoints, and
3732 static tracepoints). The feature is currently supported by the
3733 i386-linux and amd64-linux builds. See the "Tracepoints support
3734 in gdbserver" section in the manual for more information.
3736 GDBserver JIT compiles the tracepoint's conditional agent
3737 expression bytecode into native code whenever possible for low
3738 overhead dynamic tracepoints conditionals. For such tracepoints,
3739 an expression that examines program state is evaluated when the
3740 tracepoint is reached, in order to determine whether to capture
3741 trace data. If the condition is simple and false, processing the
3742 tracepoint finishes very quickly and no data is gathered.
3744 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3745 for static tracepoints support.
3747 - GDBserver now supports x86_64 Windows 64-bit debugging.
3749 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3750 it understands register description.
3752 * The --batch flag now disables pagination and queries.
3754 * X86 general purpose registers
3756 GDB now supports reading/writing byte, word and double-word x86
3757 general purpose registers directly. This means you can use, say,
3758 $ah or $ax to refer, respectively, to the byte register AH and
3759 16-bit word register AX that are actually portions of the 32-bit
3760 register EAX or 64-bit register RAX.
3762 * The `commands' command now accepts a range of breakpoints to modify.
3763 A plain `commands' following a command that creates multiple
3764 breakpoints affects all the breakpoints set by that command. This
3765 applies to breakpoints set by `rbreak', and also applies when a
3766 single `break' command creates multiple breakpoints (e.g.,
3767 breakpoints on overloaded c++ functions).
3769 * The `rbreak' command now accepts a filename specification as part of
3770 its argument, limiting the functions selected by the regex to those
3771 in the specified file.
3773 * Support for remote debugging Windows and SymbianOS shared libraries
3774 from Unix hosts has been improved. Non Windows GDB builds now can
3775 understand target reported file names that follow MS-DOS based file
3776 system semantics, such as file names that include drive letters and
3777 use the backslash character as directory separator. This makes it
3778 possible to transparently use the "set sysroot" and "set
3779 solib-search-path" on Unix hosts to point as host copies of the
3780 target's shared libraries. See the new command "set
3781 target-file-system-kind" described below, and the "Commands to
3782 specify files" section in the user manual for more information.
3786 eval template, expressions...
3787 Convert the values of one or more expressions under the control
3788 of the string template to a command line, and call it.
3790 set target-file-system-kind unix|dos-based|auto
3791 show target-file-system-kind
3792 Set or show the assumed file system kind for target reported file
3795 save breakpoints <filename>
3796 Save all current breakpoint definitions to a file suitable for use
3797 in a later debugging session. To read the saved breakpoint
3798 definitions, use the `source' command.
3800 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3803 info static-tracepoint-markers
3804 Display information about static tracepoint markers in the target.
3806 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3807 Define a static tracepoint by probing a marker at the given
3808 function, line, address, or marker ID.
3812 Enable and disable observer mode.
3814 set may-write-registers on|off
3815 set may-write-memory on|off
3816 set may-insert-breakpoints on|off
3817 set may-insert-tracepoints on|off
3818 set may-insert-fast-tracepoints on|off
3819 set may-interrupt on|off
3820 Set individual permissions for GDB effects on the target. Note that
3821 some of these settings can have undesirable or surprising
3822 consequences, particularly when changed in the middle of a session.
3823 For instance, disabling the writing of memory can prevent
3824 breakpoints from being inserted, cause single-stepping to fail, or
3825 even crash your program, if you disable after breakpoints have been
3826 inserted. However, GDB should not crash.
3828 set record memory-query on|off
3829 show record memory-query
3830 Control whether to stop the inferior if memory changes caused
3831 by an instruction cannot be recorded.
3836 The disassemble command now supports "start,+length" form of two arguments.
3840 ** GDB now provides a new directory location, called the python directory,
3841 where Python scripts written for GDB can be installed. The location
3842 of that directory is <data-directory>/python, where <data-directory>
3843 is the GDB data directory. For more details, see section `Scripting
3844 GDB using Python' in the manual.
3846 ** The GDB Python API now has access to breakpoints, symbols, symbol
3847 tables, program spaces, inferiors, threads and frame's code blocks.
3848 Additionally, GDB Parameters can now be created from the API, and
3849 manipulated via set/show in the CLI.
3851 ** New functions gdb.target_charset, gdb.target_wide_charset,
3852 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3854 ** New exception gdb.GdbError.
3856 ** Pretty-printers are now also looked up in the current program space.
3858 ** Pretty-printers can now be individually enabled and disabled.
3860 ** GDB now looks for names of Python scripts to auto-load in a
3861 special section named `.debug_gdb_scripts', in addition to looking
3862 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3864 * Tracepoint actions were unified with breakpoint commands. In particular,
3865 there are no longer differences in "info break" output for breakpoints and
3866 tracepoints and the "commands" command can be used for both tracepoints and
3867 regular breakpoints.
3871 ARM Symbian arm*-*-symbianelf*
3873 * D language support.
3874 GDB now supports debugging programs written in the D programming
3877 * GDB now supports the extended ptrace interface for PowerPC which is
3878 available since Linux kernel version 2.6.34. This automatically enables
3879 any hardware breakpoints and additional hardware watchpoints available in
3880 the processor. The old ptrace interface exposes just one hardware
3881 watchpoint and no hardware breakpoints.
3883 * GDB is now able to use the Data Value Compare (DVC) register available on
3884 embedded PowerPC processors to implement in hardware simple watchpoint
3885 conditions of the form:
3887 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3889 This works in native GDB running on Linux kernels with the extended ptrace
3890 interface mentioned above.
3892 *** Changes in GDB 7.1
3896 ** Namespace Support
3898 GDB now supports importing of namespaces in C++. This enables the
3899 user to inspect variables from imported namespaces. Support for
3900 namepace aliasing has also been added. So, if a namespace is
3901 aliased in the current scope (e.g. namepace C=A; ) the user can
3902 print variables using the alias (e.g. (gdb) print C::x).
3906 All known bugs relating to the printing of virtual base class were
3907 fixed. It is now possible to call overloaded static methods using a
3912 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3913 and reinterpret_cast<> are now handled by the C++ expression parser.
3917 Xilinx MicroBlaze microblaze-*-*
3922 Xilinx MicroBlaze microblaze
3925 * Multi-program debugging.
3927 GDB now has support for multi-program (a.k.a. multi-executable or
3928 multi-exec) debugging. This allows for debugging multiple inferiors
3929 simultaneously each running a different program under the same GDB
3930 session. See "Debugging Multiple Inferiors and Programs" in the
3931 manual for more information. This implied some user visible changes
3932 in the multi-inferior support. For example, "info inferiors" now
3933 lists inferiors that are not running yet or that have exited
3934 already. See also "New commands" and "New options" below.
3936 * New tracing features
3938 GDB's tracepoint facility now includes several new features:
3940 ** Trace state variables
3942 GDB tracepoints now include support for trace state variables, which
3943 are variables managed by the target agent during a tracing
3944 experiment. They are useful for tracepoints that trigger each
3945 other, so for instance one tracepoint can count hits in a variable,
3946 and then a second tracepoint has a condition that is true when the
3947 count reaches a particular value. Trace state variables share the
3948 $-syntax of GDB convenience variables, and can appear in both
3949 tracepoint actions and condition expressions. Use the "tvariable"
3950 command to create, and "info tvariables" to view; see "Trace State
3951 Variables" in the manual for more detail.
3955 GDB now includes an option for defining fast tracepoints, which
3956 targets may implement more efficiently, such as by installing a jump
3957 into the target agent rather than a trap instruction. The resulting
3958 speedup can be by two orders of magnitude or more, although the
3959 tradeoff is that some program locations on some target architectures
3960 might not allow fast tracepoint installation, for instance if the
3961 instruction to be replaced is shorter than the jump. To request a
3962 fast tracepoint, use the "ftrace" command, with syntax identical to
3963 the regular trace command.
3965 ** Disconnected tracing
3967 It is now possible to detach GDB from the target while it is running
3968 a trace experiment, then reconnect later to see how the experiment
3969 is going. In addition, a new variable disconnected-tracing lets you
3970 tell the target agent whether to continue running a trace if the
3971 connection is lost unexpectedly.
3975 GDB now has the ability to save the trace buffer into a file, and
3976 then use that file as a target, similarly to you can do with
3977 corefiles. You can select trace frames, print data that was
3978 collected in them, and use tstatus to display the state of the
3979 tracing run at the moment that it was saved. To create a trace
3980 file, use "tsave <filename>", and to use it, do "target tfile
3983 ** Circular trace buffer
3985 You can ask the target agent to handle the trace buffer as a
3986 circular buffer, discarding the oldest trace frames to make room for
3987 newer ones, by setting circular-trace-buffer to on. This feature may
3988 not be available for all target agents.
3993 The disassemble command, when invoked with two arguments, now requires
3994 the arguments to be comma-separated.
3997 The info variables command now displays variable definitions. Files
3998 which only declare a variable are not shown.
4001 The source command is now capable of sourcing Python scripts.
4002 This feature is dependent on the debugger being build with Python
4005 Related to this enhancement is also the introduction of a new command
4006 "set script-extension" (see below).
4008 * New commands (for set/show, see "New options" below)
4010 record save [<FILENAME>]
4011 Save a file (in core file format) containing the process record
4012 execution log for replay debugging at a later time.
4014 record restore <FILENAME>
4015 Restore the process record execution log that was saved at an
4016 earlier time, for replay debugging.
4018 add-inferior [-copies <N>] [-exec <FILENAME>]
4021 clone-inferior [-copies <N>] [ID]
4022 Make a new inferior ready to execute the same program another
4023 inferior has loaded.
4028 maint info program-spaces
4029 List the program spaces loaded into GDB.
4031 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4032 show remote interrupt-sequence
4033 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4034 as the sequence to the remote target in order to interrupt the execution.
4035 Ctrl-C is a default. Some system prefers BREAK which is high level of
4036 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4037 Magic SysRq g. It is BREAK signal and character 'g'.
4039 set remote interrupt-on-connect [on | off]
4040 show remote interrupt-on-connect
4041 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4042 remote target when gdb connects to it. This is needed when you debug
4045 set remotebreak [on | off]
4047 Deprecated. Use "set/show remote interrupt-sequence" instead.
4049 tvariable $NAME [ = EXP ]
4050 Create or modify a trace state variable.
4053 List trace state variables and their values.
4055 delete tvariable $NAME ...
4056 Delete one or more trace state variables.
4059 Evaluate the given expressions without collecting anything into the
4060 trace buffer. (Valid in tracepoint actions only.)
4062 ftrace FN / FILE:LINE / *ADDR
4063 Define a fast tracepoint at the given function, line, or address.
4065 * New expression syntax
4067 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4068 GDB now parses 0b101010 identically with 42.
4072 set follow-exec-mode new|same
4073 show follow-exec-mode
4074 Control whether GDB reuses the same inferior across an exec call or
4075 creates a new one. This is useful to be able to restart the old
4076 executable after the inferior having done an exec call.
4078 set default-collect EXPR, ...
4079 show default-collect
4080 Define a list of expressions to be collected at each tracepoint.
4081 This is a useful way to ensure essential items are not overlooked,
4082 such as registers or a critical global variable.
4084 set disconnected-tracing
4085 show disconnected-tracing
4086 If set to 1, the target is instructed to continue tracing if it
4087 loses its connection to GDB. If 0, the target is to stop tracing
4090 set circular-trace-buffer
4091 show circular-trace-buffer
4092 If set to on, the target is instructed to use a circular trace buffer
4093 and discard the oldest trace frames instead of stopping the trace due
4094 to a full trace buffer. If set to off, the trace stops when the buffer
4095 fills up. Some targets may not support this.
4097 set script-extension off|soft|strict
4098 show script-extension
4099 If set to "off", the debugger does not perform any script language
4100 recognition, and all sourced files are assumed to be GDB scripts.
4101 If set to "soft" (the default), files are sourced according to
4102 filename extension, falling back to GDB scripts if the first
4104 If set to "strict", files are sourced according to filename extension.
4106 set ada trust-PAD-over-XVS on|off
4107 show ada trust-PAD-over-XVS
4108 If off, activate a workaround against a bug in the debugging information
4109 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4110 the GCC sources for more information about the GNAT encoding and
4111 PAD types in particular). It is always safe to set this option to
4112 off, but this introduces a slight performance penalty. The default
4115 * Python API Improvements
4117 ** GDB provides the new class gdb.LazyString. This is useful in
4118 some pretty-printing cases. The new method gdb.Value.lazy_string
4119 provides a simple way to create objects of this type.
4121 ** The fields returned by gdb.Type.fields now have an
4122 `is_base_class' attribute.
4124 ** The new method gdb.Type.range returns the range of an array type.
4126 ** The new method gdb.parse_and_eval can be used to parse and
4127 evaluate an expression.
4129 * New remote packets
4132 Define a trace state variable.
4135 Get the current value of a trace state variable.
4138 Set desired tracing behavior upon disconnection.
4141 Set the trace buffer to be linear or circular.
4144 Get data about the tracepoints currently in use.
4148 Process record now works correctly with hardware watchpoints.
4150 Multiple bug fixes have been made to the mips-irix port, making it
4151 much more reliable. In particular:
4152 - Debugging threaded applications is now possible again. Previously,
4153 GDB would hang while starting the program, or while waiting for
4154 the program to stop at a breakpoint.
4155 - Attaching to a running process no longer hangs.
4156 - An error occurring while loading a core file has been fixed.
4157 - Changing the value of the PC register now works again. This fixes
4158 problems observed when using the "jump" command, or when calling
4159 a function from GDB, or even when assigning a new value to $pc.
4160 - With the "finish" and "return" commands, the return value for functions
4161 returning a small array is now correctly printed.
4162 - It is now possible to break on shared library code which gets executed
4163 during a shared library init phase (code executed while executing
4164 their .init section). Previously, the breakpoint would have no effect.
4165 - GDB is now able to backtrace through the signal handler for
4166 non-threaded programs.
4168 PIE (Position Independent Executable) programs debugging is now supported.
4169 This includes debugging execution of PIC (Position Independent Code) shared
4170 libraries although for that, it should be possible to run such libraries as an
4173 *** Changes in GDB 7.0
4175 * GDB now has an interface for JIT compilation. Applications that
4176 dynamically generate code can create symbol files in memory and register
4177 them with GDB. For users, the feature should work transparently, and
4178 for JIT developers, the interface is documented in the GDB manual in the
4179 "JIT Compilation Interface" chapter.
4181 * Tracepoints may now be conditional. The syntax is as for
4182 breakpoints; either an "if" clause appended to the "trace" command,
4183 or the "condition" command is available. GDB sends the condition to
4184 the target for evaluation using the same bytecode format as is used
4185 for tracepoint actions.
4187 * The disassemble command now supports: an optional /r modifier, print the
4188 raw instructions in hex as well as in symbolic form, and an optional /m
4189 modifier to print mixed source+assembly.
4191 * Process record and replay
4193 In a architecture environment that supports ``process record and
4194 replay'', ``process record and replay'' target can record a log of
4195 the process execution, and replay it with both forward and reverse
4198 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4199 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4200 set execution-direction {forward|reverse}, for targets that support
4203 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4204 feature is available with a native GDB running on kernel version
4207 * GDB now has support for multi-byte and wide character sets on the
4208 target. Strings whose character type is wchar_t, char16_t, or
4209 char32_t are now correctly printed. GDB supports wide- and unicode-
4210 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4211 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4212 `printf'. This feature requires iconv to work properly; if your
4213 system does not have a working iconv, GDB can use GNU libiconv. See
4214 the installation instructions for more information.
4216 * GDB now supports automatic retrieval of shared library files from
4217 remote targets. To use this feature, specify a system root that begins
4218 with the `remote:' prefix, either via the `set sysroot' command or via
4219 the `--with-sysroot' configure-time option.
4221 * "info sharedlibrary" now takes an optional regex of libraries to show,
4222 and it now reports if a shared library has no debugging information.
4224 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4225 now complete on file names.
4227 * When completing in expressions, gdb will attempt to limit
4228 completions to allowable structure or union fields, where appropriate.
4229 For instance, consider:
4231 # struct example { int f1; double f2; };
4232 # struct example variable;
4235 If the user types TAB at the end of this command line, the available
4236 completions will be "f1" and "f2".
4238 * Inlined functions are now supported. They show up in backtraces, and
4239 the "step", "next", and "finish" commands handle them automatically.
4241 * GDB now supports the token-splicing (##) and stringification (#)
4242 operators when expanding macros. It also supports variable-arity
4245 * GDB now supports inspecting extra signal information, exported by
4246 the new $_siginfo convenience variable. The feature is currently
4247 implemented on linux ARM, i386 and amd64.
4249 * GDB can now display the VFP floating point registers and NEON vector
4250 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4251 can provide these registers (requires Linux 2.6.30 or later). Remote
4252 and simulator targets may also provide them.
4254 * New remote packets
4257 Search memory for a sequence of bytes.
4260 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4261 operation over reliable transport links. Use of this packet is
4262 controlled by the `set remote noack-packet' command.
4265 Kill the process with the specified process ID. Use this in preference
4266 to `k' when multiprocess protocol extensions are supported.
4269 Obtains additional operating system information
4273 Read or write additional signal information.
4275 * Removed remote protocol undocumented extension
4277 An undocumented extension to the remote protocol's `S' stop reply
4278 packet that permitted the stub to pass a process id was removed.
4279 Remote servers should use the `T' stop reply packet instead.
4281 * GDB now supports multiple function calling conventions according to the
4282 DWARF-2 DW_AT_calling_convention function attribute.
4284 * The SH target utilizes the aforementioned change to distinguish between gcc
4285 and Renesas calling convention. It also adds the new CLI commands
4286 `set/show sh calling-convention'.
4288 * GDB can now read compressed debug sections, as produced by GNU gold
4289 with the --compress-debug-sections=zlib flag.
4291 * 64-bit core files are now supported on AIX.
4293 * Thread switching is now supported on Tru64.
4295 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4296 which will be allocated using malloc later in program execution.
4298 * The qXfer:libraries:read remote protocol packet now allows passing a
4299 list of section offsets.
4301 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4302 conditions handling signals delivered during attach or thread creation
4303 have also been fixed.
4305 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4306 From the user's standpoint, all unqualified instances of True and False
4307 are treated as the standard definitions, regardless of context.
4309 * GDB now parses C++ symbol and type names more flexibly. For
4312 template<typename T> class C { };
4315 GDB will now correctly handle all of:
4317 ptype C<char const *>
4318 ptype C<char const*>
4319 ptype C<const char *>
4320 ptype C<const char*>
4322 * New features in the GDB remote stub, gdbserver
4324 - The "--wrapper" command-line argument tells gdbserver to use a
4325 wrapper program to launch programs for debugging.
4327 - On PowerPC and S/390 targets, it is now possible to use a single
4328 gdbserver executable to debug both 32-bit and 64-bit programs.
4329 (This requires gdbserver itself to be built as a 64-bit executable.)
4331 - gdbserver uses the new noack protocol mode for TCP connections to
4332 reduce communications latency, if also supported and enabled in GDB.
4334 - Support for the sparc64-linux-gnu target is now included in
4337 - The amd64-linux build of gdbserver now supports debugging both
4338 32-bit and 64-bit programs.
4340 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4341 now support hardware watchpoints, and will use them automatically
4346 GDB now has support for scripting using Python. Whether this is
4347 available is determined at configure time.
4349 New GDB commands can now be written in Python.
4351 * Ada tasking support
4353 Ada tasks can now be inspected in GDB. The following commands have
4357 Print the list of Ada tasks.
4359 Print detailed information about task number N.
4361 Print the task number of the current task.
4363 Switch the context of debugging to task number N.
4365 * Support for user-defined prefixed commands. The "define" command can
4366 add new commands to existing prefixes, e.g. "target".
4368 * Multi-inferior, multi-process debugging.
4370 GDB now has generalized support for multi-inferior debugging. See
4371 "Debugging Multiple Inferiors" in the manual for more information.
4372 Although availability still depends on target support, the command
4373 set is more uniform now. The GNU/Linux specific multi-forks support
4374 has been migrated to this new framework. This implied some user
4375 visible changes; see "New commands" and also "Removed commands"
4378 * Target descriptions can now describe the target OS ABI. See the
4379 "Target Description Format" section in the user manual for more
4382 * Target descriptions can now describe "compatible" architectures
4383 to indicate that the target can execute applications for a different
4384 architecture in addition to those for the main target architecture.
4385 See the "Target Description Format" section in the user manual for
4388 * Multi-architecture debugging.
4390 GDB now includes general supports for debugging applications on
4391 hybrid systems that use more than one single processor architecture
4392 at the same time. Each such hybrid architecture still requires
4393 specific support to be added. The only hybrid architecture supported
4394 in this version of GDB is the Cell Broadband Engine.
4396 * GDB now supports integrated debugging of Cell/B.E. applications that
4397 use both the PPU and SPU architectures. To enable support for hybrid
4398 Cell/B.E. debugging, you need to configure GDB to support both the
4399 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4400 --enable-targets configure option.
4402 * Non-stop mode debugging.
4404 For some targets, GDB now supports an optional mode of operation in
4405 which you can examine stopped threads while other threads continue
4406 to execute freely. This is referred to as non-stop mode, with the
4407 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4408 section in the user manual for more information.
4410 To be able to support remote non-stop debugging, a remote stub needs
4411 to implement the non-stop mode remote protocol extensions, as
4412 described in the "Remote Non-Stop" section of the user manual. The
4413 GDB remote stub, gdbserver, has been adjusted to support these
4414 extensions on linux targets.
4416 * New commands (for set/show, see "New options" below)
4418 catch syscall [NAME(S) | NUMBER(S)]
4419 Catch system calls. Arguments, which should be names of system
4420 calls or their numbers, mean catch only those syscalls. Without
4421 arguments, every syscall will be caught. When the inferior issues
4422 any of the specified syscalls, GDB will stop and announce the system
4423 call, both when it is called and when its call returns. This
4424 feature is currently available with a native GDB running on the
4425 Linux Kernel, under the following architectures: x86, x86_64,
4426 PowerPC and PowerPC64.
4428 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4430 Search memory for a sequence of bytes.
4432 maint set python print-stack
4433 maint show python print-stack
4434 Show a stack trace when an error is encountered in a Python script.
4437 Invoke CODE by passing it to the Python interpreter.
4442 These allow macros to be defined, undefined, and listed
4446 Show operating system information about processes.
4449 List the inferiors currently under GDB's control.
4452 Switch focus to inferior number NUM.
4455 Detach from inferior number NUM.
4458 Kill inferior number NUM.
4462 set spu stop-on-load
4463 show spu stop-on-load
4464 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4466 set spu auto-flush-cache
4467 show spu auto-flush-cache
4468 Control whether to automatically flush the software-managed cache
4469 during Cell/B.E. debugging.
4471 set sh calling-convention
4472 show sh calling-convention
4473 Control the calling convention used when calling SH target functions.
4476 show debug timestamp
4477 Control display of timestamps with GDB debugging output.
4479 set disassemble-next-line
4480 show disassemble-next-line
4481 Control display of disassembled source lines or instructions when
4484 set remote noack-packet
4485 show remote noack-packet
4486 Set/show the use of remote protocol QStartNoAckMode packet. See above
4487 under "New remote packets."
4489 set remote query-attached-packet
4490 show remote query-attached-packet
4491 Control use of remote protocol `qAttached' (query-attached) packet.
4493 set remote read-siginfo-object
4494 show remote read-siginfo-object
4495 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4498 set remote write-siginfo-object
4499 show remote write-siginfo-object
4500 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4503 set remote reverse-continue
4504 show remote reverse-continue
4505 Control use of remote protocol 'bc' (reverse-continue) packet.
4507 set remote reverse-step
4508 show remote reverse-step
4509 Control use of remote protocol 'bs' (reverse-step) packet.
4511 set displaced-stepping
4512 show displaced-stepping
4513 Control displaced stepping mode. Displaced stepping is a way to
4514 single-step over breakpoints without removing them from the debuggee.
4515 Also known as "out-of-line single-stepping".
4518 show debug displaced
4519 Control display of debugging info for displaced stepping.
4521 maint set internal-error
4522 maint show internal-error
4523 Control what GDB does when an internal error is detected.
4525 maint set internal-warning
4526 maint show internal-warning
4527 Control what GDB does when an internal warning is detected.
4532 Use a wrapper program to launch programs for debugging.
4534 set multiple-symbols (all|ask|cancel)
4535 show multiple-symbols
4536 The value of this variable can be changed to adjust the debugger behavior
4537 when an expression or a breakpoint location contains an ambiguous symbol
4538 name (an overloaded function name, for instance).
4540 set breakpoint always-inserted
4541 show breakpoint always-inserted
4542 Keep breakpoints always inserted in the target, as opposed to inserting
4543 them when resuming the target, and removing them when the target stops.
4544 This option can improve debugger performance on slow remote targets.
4546 set arm fallback-mode (arm|thumb|auto)
4547 show arm fallback-mode
4548 set arm force-mode (arm|thumb|auto)
4550 These commands control how ARM GDB determines whether instructions
4551 are ARM or Thumb. The default for both settings is auto, which uses
4552 the current CPSR value for instructions without symbols; previous
4553 versions of GDB behaved as if "set arm fallback-mode arm".
4555 set disable-randomization
4556 show disable-randomization
4557 Standalone programs run with the virtual address space randomization enabled
4558 by default on some platforms. This option keeps the addresses stable across
4559 multiple debugging sessions.
4563 Control whether other threads are stopped or not when some thread hits
4568 Requests that asynchronous execution is enabled in the target, if available.
4569 In this case, it's possible to resume target in the background, and interact
4570 with GDB while the target is running. "show target-async" displays the
4571 current state of asynchronous execution of the target.
4573 set target-wide-charset
4574 show target-wide-charset
4575 The target-wide-charset is the name of the character set that GDB
4576 uses when printing characters whose type is wchar_t.
4578 set tcp auto-retry (on|off)
4580 set tcp connect-timeout
4581 show tcp connect-timeout
4582 These commands allow GDB to retry failed TCP connections to a remote stub
4583 with a specified timeout period; this is useful if the stub is launched
4584 in parallel with GDB but may not be ready to accept connections immediately.
4586 set libthread-db-search-path
4587 show libthread-db-search-path
4588 Control list of directories which GDB will search for appropriate
4591 set schedule-multiple (on|off)
4592 show schedule-multiple
4593 Allow GDB to resume all threads of all processes or only threads of
4594 the current process.
4598 Use more aggressive caching for accesses to the stack. This improves
4599 performance of remote debugging (particularly backtraces) without
4600 affecting correctness.
4602 set interactive-mode (on|off|auto)
4603 show interactive-mode
4604 Control whether GDB runs in interactive mode (on) or not (off).
4605 When in interactive mode, GDB waits for the user to answer all
4606 queries. Otherwise, GDB does not wait and assumes the default
4607 answer. When set to auto (the default), GDB determines which
4608 mode to use based on the stdin settings.
4613 For program forks, this is replaced by the new more generic `info
4614 inferiors' command. To list checkpoints, you can still use the
4615 `info checkpoints' command, which was an alias for the `info forks'
4619 Replaced by the new `inferior' command. To switch between
4620 checkpoints, you can still use the `restart' command, which was an
4621 alias for the `fork' command.
4624 This is removed, since some targets don't have a notion of
4625 processes. To switch between processes, you can still use the
4626 `inferior' command using GDB's own inferior number.
4629 For program forks, this is replaced by the new more generic `kill
4630 inferior' command. To delete a checkpoint, you can still use the
4631 `delete checkpoint' command, which was an alias for the `delete
4635 For program forks, this is replaced by the new more generic `detach
4636 inferior' command. To detach a checkpoint, you can still use the
4637 `detach checkpoint' command, which was an alias for the `detach
4640 * New native configurations
4642 x86/x86_64 Darwin i[34567]86-*-darwin*
4644 x86_64 MinGW x86_64-*-mingw*
4648 Lattice Mico32 lm32-*
4649 x86 DICOS i[34567]86-*-dicos*
4650 x86_64 DICOS x86_64-*-dicos*
4653 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4654 (mingw32ce) debugging.
4660 These commands were actually not implemented on any target.
4662 *** Changes in GDB 6.8
4664 * New native configurations
4666 NetBSD/hppa hppa*-*netbsd*
4667 Xtensa GNU/Linux xtensa*-*-linux*
4671 NetBSD/hppa hppa*-*-netbsd*
4672 Xtensa GNU/Linux xtensa*-*-linux*
4674 * Change in command line behavior -- corefiles vs. process ids.
4676 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4677 attaching to process NUMBER fails, GDB no longer attempts to open a
4678 core file named NUMBER. Attaching to a program using the -c option
4679 is no longer supported. Instead, use the '-p' or '--pid' options.
4681 * GDB can now be built as a native debugger for debugging Windows x86
4682 (mingw32) Portable Executable (PE) programs.
4684 * Pending breakpoints no longer change their number when their address
4687 * GDB now supports breakpoints with multiple locations,
4688 including breakpoints on C++ constructors, inside C++ templates,
4689 and in inlined functions.
4691 * GDB's ability to debug optimized code has been improved. GDB more
4692 accurately identifies function bodies and lexical blocks that occupy
4693 more than one contiguous range of addresses.
4695 * Target descriptions can now describe registers for PowerPC.
4697 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4698 registers on PowerPC targets.
4700 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4701 targets even when the libthread_db library is not available.
4703 * The GDB remote stub, gdbserver, now supports the new file transfer
4704 commands (remote put, remote get, and remote delete).
4706 * The GDB remote stub, gdbserver, now supports run and attach in
4707 extended-remote mode.
4709 * hppa*64*-*-hpux11* target broken
4710 The debugger is unable to start a program and fails with the following
4711 error: "Error trying to get information about dynamic linker".
4712 The gdb-6.7 release is also affected.
4714 * GDB now supports the --enable-targets= configure option to allow
4715 building a single GDB executable that supports multiple remote
4716 target architectures.
4718 * GDB now supports debugging C and C++ programs which use the
4719 Decimal Floating Point extension. In addition, the PowerPC target
4720 now has a set of pseudo-registers to inspect decimal float values
4721 stored in two consecutive float registers.
4723 * The -break-insert MI command can optionally create pending
4726 * Improved support for debugging Ada
4727 Many improvements to the Ada language support have been made. These
4729 - Better support for Ada2005 interface types
4730 - Improved handling of arrays and slices in general
4731 - Better support for Taft-amendment types
4732 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4734 - Improved command completion in Ada
4737 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4742 set print frame-arguments (all|scalars|none)
4743 show print frame-arguments
4744 The value of this variable can be changed to control which argument
4745 values should be printed by the debugger when displaying a frame.
4750 Transfer files to and from a remote target, and delete remote files.
4757 Transfer files to and from a remote target, and delete remote files.
4759 * New remote packets
4766 Open, close, read, write, and delete files on the remote system.
4769 Attach to an existing process on the remote system, in extended-remote
4773 Run a new process on the remote system, in extended-remote mode.
4775 *** Changes in GDB 6.7
4777 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4778 bfd, libiberty and opcodes, as revealed by static analysis donated by
4779 Coverity, Inc. (http://scan.coverity.com).
4781 * When looking up multiply-defined global symbols, GDB will now prefer the
4782 symbol definition in the current shared library if it was built using the
4783 -Bsymbolic linker option.
4785 * When the Text User Interface (TUI) is not configured, GDB will now
4786 recognize the -tui command-line option and print a message that the TUI
4789 * The GDB remote stub, gdbserver, now has lower overhead for high
4790 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4792 * GDB for MIPS targets now autodetects whether a remote target provides
4793 32-bit or 64-bit register values.
4795 * Support for C++ member pointers has been improved.
4797 * GDB now understands XML target descriptions, which specify the
4798 target's overall architecture. GDB can read a description from
4799 a local file or over the remote serial protocol.
4801 * Vectors of single-byte data use a new integer type which is not
4802 automatically displayed as character or string data.
4804 * The /s format now works with the print command. It displays
4805 arrays of single-byte integers and pointers to single-byte integers
4808 * Target descriptions can now describe target-specific registers,
4809 for architectures which have implemented the support (currently
4810 only ARM, M68K, and MIPS).
4812 * GDB and the GDB remote stub, gdbserver, now support the XScale
4815 * The GDB remote stub, gdbserver, has been updated to support
4816 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4817 has been rewritten to use the standard GDB remote protocol.
4819 * GDB can now step into C++ functions which are called through thunks.
4821 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4823 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4824 layout. It also supports a TextSeg= and DataSeg= response when only
4825 segment base addresses (rather than offsets) are available.
4827 * The /i format now outputs any trailing branch delay slot instructions
4828 immediately following the last instruction within the count specified.
4830 * The GDB remote protocol "T" stop reply packet now supports a
4831 "library" response. Combined with the new "qXfer:libraries:read"
4832 packet, this response allows GDB to debug shared libraries on targets
4833 where the operating system manages the list of loaded libraries (e.g.
4834 Windows and SymbianOS).
4836 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4837 (DLLs) on Windows and Windows CE targets.
4839 * GDB now supports a faster verification that a .debug file matches its binary
4840 according to its build-id signature, if the signature is present.
4846 Enable or disable hardware flow control (RTS/CTS) on the serial port
4847 when debugging using remote targets.
4849 set mem inaccessible-by-default
4850 show mem inaccessible-by-default
4851 If the target supplies a memory map, for instance via the remote
4852 protocol's "qXfer:memory-map:read" packet, setting this variable
4853 prevents GDB from accessing memory outside the memory map. This
4854 is useful for targets with memory mapped registers or which react
4855 badly to accesses of unmapped address space.
4857 set breakpoint auto-hw
4858 show breakpoint auto-hw
4859 If the target supplies a memory map, for instance via the remote
4860 protocol's "qXfer:memory-map:read" packet, setting this variable
4861 lets GDB use hardware breakpoints automatically for memory regions
4862 where it can not use software breakpoints. This covers both the
4863 "break" command and internal breakpoints used for other commands
4864 including "next" and "finish".
4867 catch exception unhandled
4868 Stop the program execution when Ada exceptions are raised.
4871 Stop the program execution when an Ada assertion failed.
4875 Set an alternate system root for target files. This is a more
4876 general version of "set solib-absolute-prefix", which is now
4877 an alias to "set sysroot".
4880 Provide extended SPU facility status information. This set of
4881 commands is available only when debugging the Cell/B.E. SPU
4884 * New native configurations
4886 OpenBSD/sh sh*-*openbsd*
4889 unset tdesc filename
4891 Use the specified local file as an XML target description, and do
4892 not query the target for its built-in description.
4896 OpenBSD/sh sh*-*-openbsd*
4897 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4898 Toshiba Media Processor mep-elf
4900 * New remote packets
4903 Ignore the specified signals; pass them directly to the debugged program
4904 without stopping other threads or reporting them to GDB.
4906 qXfer:features:read:
4907 Read an XML target description from the target, which describes its
4912 Read or write contents of an spufs file on the target system. These
4913 packets are available only on the Cell/B.E. SPU architecture.
4915 qXfer:libraries:read:
4916 Report the loaded shared libraries. Combined with new "T" packet
4917 response, this packet allows GDB to debug shared libraries on
4918 targets where the operating system manages the list of loaded
4919 libraries (e.g. Windows and SymbianOS).
4923 Support for these obsolete configurations has been removed.
4931 i[34567]86-*-lynxos*
4932 i[34567]86-*-netware*
4933 i[34567]86-*-sco3.2v5*
4934 i[34567]86-*-sco3.2v4*
4936 i[34567]86-*-sysv4.2*
4939 i[34567]86-*-unixware2*
4940 i[34567]86-*-unixware*
4949 * Other removed features
4956 Various m68k-only ROM monitors.
4963 Various Renesas ROM monitors and debugging interfaces for SH and
4968 Support for a Macraigor serial interface to on-chip debugging.
4969 GDB does not directly support the newer parallel or USB
4974 A debug information format. The predecessor to DWARF 2 and
4975 DWARF 3, which are still supported.
4977 Support for the HP aCC compiler on HP-UX/PA-RISC
4979 SOM-encapsulated symbolic debugging information, automatic
4980 invocation of pxdb, and the aCC custom C++ ABI. This does not
4981 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4982 with aCC can still be debugged on an assembly level.
4984 MIPS ".pdr" sections
4986 A MIPS-specific format used to describe stack frame layout
4987 in debugging information.
4991 GDB could work with an older version of Guile to debug
4992 the interpreter and Scheme programs running in it.
4994 set mips stack-arg-size
4995 set mips saved-gpreg-size
4997 Use "set mips abi" to control parameter passing for MIPS.
4999 *** Changes in GDB 6.6
5004 Cell Broadband Engine SPU spu-elf
5006 * GDB can now be configured as a cross-debugger targeting native Windows
5007 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5008 running on a Windows system over TCP/IP to debug Windows programs.
5010 * The GDB remote stub, gdbserver, has been updated to support Windows and
5011 Cygwin debugging. Both single-threaded and multi-threaded programs are
5014 * The "set trust-readonly-sections" command works again. This command was
5015 broken in GDB 6.3, 6.4, and 6.5.
5017 * The "load" command now supports writing to flash memory, if the remote
5018 stub provides the required support.
5020 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5021 longer requires symbolic debug information (e.g. DWARF-2).
5026 unset substitute-path
5027 show substitute-path
5028 Manage a list of substitution rules that GDB uses to rewrite the name
5029 of the directories where the sources are located. This can be useful
5030 for instance when the sources were moved to a different location
5031 between compilation and debugging.
5035 Print each CLI command as it is executed. Each command is prefixed with
5036 a number of `+' symbols representing the nesting depth.
5037 The source command now has a `-v' option to enable the same feature.
5041 The ARM Demon monitor support (RDP protocol, "target rdp").
5043 Kernel Object Display, an embedded debugging feature which only worked with
5044 an obsolete version of Cisco IOS.
5046 The 'set download-write-size' and 'show download-write-size' commands.
5048 * New remote packets
5051 Tell a stub about GDB client features, and request remote target features.
5052 The first feature implemented is PacketSize, which allows the target to
5053 specify the size of packets it can handle - to minimize the number of
5054 packets required and improve performance when connected to a remote
5058 Fetch an OS auxilliary vector from the remote stub. This packet is a
5059 more efficient replacement for qPart:auxv:read.
5061 qXfer:memory-map:read:
5062 Fetch a memory map from the remote stub, including information about
5063 RAM, ROM, and flash memory devices.
5068 Erase and program a flash memory device.
5070 * Removed remote packets
5073 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5074 used it, and only gdbserver implemented it.
5076 *** Changes in GDB 6.5
5080 Renesas M32C/M16C m32c-elf
5082 Morpho Technologies ms1 ms1-elf
5086 init-if-undefined Initialize a convenience variable, but
5087 only if it doesn't already have a value.
5089 The following commands are presently only implemented for native GNU/Linux:
5091 checkpoint Save a snapshot of the program state.
5093 restart <n> Return the program state to a
5094 previously saved state.
5096 info checkpoints List currently saved checkpoints.
5098 delete-checkpoint <n> Delete a previously saved checkpoint.
5100 set|show detach-on-fork Tell gdb whether to detach from a newly
5101 forked process, or to keep debugging it.
5103 info forks List forks of the user program that
5104 are available to be debugged.
5106 fork <n> Switch to debugging one of several
5107 forks of the user program that are
5108 available to be debugged.
5110 delete-fork <n> Delete a fork from the list of forks
5111 that are available to be debugged (and
5112 kill the forked process).
5114 detach-fork <n> Delete a fork from the list of forks
5115 that are available to be debugged (and
5116 allow the process to continue).
5120 Morpho Technologies ms2 ms1-elf
5122 * Improved Windows host support
5124 GDB now builds as a cross debugger hosted on i686-mingw32, including
5125 native console support, and remote communications using either
5126 network sockets or serial ports.
5128 * Improved Modula-2 language support
5130 GDB can now print most types in the Modula-2 syntax. This includes:
5131 basic types, set types, record types, enumerated types, range types,
5132 pointer types and ARRAY types. Procedure var parameters are correctly
5133 printed and hexadecimal addresses and character constants are also
5134 written in the Modula-2 syntax. Best results can be obtained by using
5135 GNU Modula-2 together with the -gdwarf-2 command line option.
5139 The ARM rdi-share module.
5141 The Netware NLM debug server.
5143 *** Changes in GDB 6.4
5145 * New native configurations
5147 OpenBSD/arm arm*-*-openbsd*
5148 OpenBSD/mips64 mips64-*-openbsd*
5152 Morpho Technologies ms1 ms1-elf
5154 * New command line options
5156 --batch-silent As for --batch, but totally silent.
5157 --return-child-result The debugger will exist with the same value
5158 the child (debugged) program exited with.
5159 --eval-command COMMAND, -ex COMMAND
5160 Execute a single GDB CLI command. This may be
5161 specified multiple times and in conjunction
5162 with the --command (-x) option.
5164 * Deprecated commands removed
5166 The following commands, that were deprecated in 2000, have been
5170 set|show arm disassembly-flavor set|show arm disassembler
5171 othernames set arm disassembler
5172 set|show remotedebug set|show debug remote
5173 set|show archdebug set|show debug arch
5174 set|show eventdebug set|show debug event
5177 * New BSD user-level threads support
5179 It is now possible to debug programs using the user-level threads
5180 library on OpenBSD and FreeBSD. Currently supported (target)
5183 FreeBSD/amd64 x86_64-*-freebsd*
5184 FreeBSD/i386 i386-*-freebsd*
5185 OpenBSD/i386 i386-*-openbsd*
5187 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5188 are not yet supported.
5190 * New support for Matsushita MN10300 w/sim added
5191 (Work in progress). mn10300-elf.
5193 * REMOVED configurations and files
5195 VxWorks and the XDR protocol *-*-vxworks
5196 Motorola MCORE mcore-*-*
5197 National Semiconductor NS32000 ns32k-*-*
5199 * New "set print array-indexes" command
5201 After turning this setting "on", GDB prints the index of each element
5202 when displaying arrays. The default is "off" to preserve the previous
5205 * VAX floating point support
5207 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5209 * User-defined command support
5211 In addition to using $arg0..$arg9 for argument passing, it is now possible
5212 to use $argc to determine now many arguments have been passed. See the
5213 section on user-defined commands in the user manual for more information.
5215 *** Changes in GDB 6.3:
5217 * New command line option
5219 GDB now accepts -l followed by a number to set the timeout for remote
5222 * GDB works with GCC -feliminate-dwarf2-dups
5224 GDB now supports a more compact representation of DWARF-2 debug
5225 information using DW_FORM_ref_addr references. These are produced
5226 by GCC with the option -feliminate-dwarf2-dups and also by some
5227 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5228 to use -feliminate-dwarf2-dups.
5230 * Internationalization
5232 When supported by the host system, GDB will be built with
5233 internationalization (libintl). The task of marking up the sources is
5234 continued, we're looking forward to our first translation.
5238 Initial support for debugging programs compiled with the GNAT
5239 implementation of the Ada programming language has been integrated
5240 into GDB. In this release, support is limited to expression evaluation.
5242 * New native configurations
5244 GNU/Linux/m32r m32r-*-linux-gnu
5248 GDB's remote protocol now includes support for the 'p' packet. This
5249 packet is used to fetch individual registers from a remote inferior.
5251 * END-OF-LIFE registers[] compatibility module
5253 GDB's internal register infrastructure has been completely rewritten.
5254 The new infrastructure making possible the implementation of key new
5255 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5258 GDB 6.3 will be the last release to include the registers[]
5259 compatibility module that allowed out-of-date configurations to
5260 continue to work. This change directly impacts the following
5270 powerpc bdm protocol
5272 Unless there is activity to revive these configurations, they will be
5273 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5275 * OBSOLETE configurations and files
5277 Configurations that have been declared obsolete in this release have
5278 been commented out. Unless there is activity to revive these
5279 configurations, the next release of GDB will have their sources
5280 permanently REMOVED.
5289 *** Changes in GDB 6.2.1:
5291 * MIPS `break main; run' gave an heuristic-fence-post warning
5293 When attempting to run even a simple program, a warning about
5294 heuristic-fence-post being hit would be reported. This problem has
5297 * MIPS IRIX 'long double' crashed GDB
5299 When examining a long double variable, GDB would get a segmentation
5300 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5301 IRIX long double values).
5305 A bug in the VAX stack code was causing problems with the "next"
5306 command. This problem has been fixed.
5308 *** Changes in GDB 6.2:
5310 * Fix for ``many threads''
5312 On GNU/Linux systems that use the NPTL threads library, a program
5313 rapidly creating and deleting threads would confuse GDB leading to the
5316 ptrace: No such process.
5317 thread_db_get_info: cannot get thread info: generic error
5319 This problem has been fixed.
5321 * "-async" and "-noasync" options removed.
5323 Support for the broken "-noasync" option has been removed (it caused
5326 * New ``start'' command.
5328 This command runs the program until the beginning of the main procedure.
5330 * New BSD Kernel Data Access Library (libkvm) interface
5332 Using ``target kvm'' it is now possible to debug kernel core dumps and
5333 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5334 platforms. Currently supported (native-only) configurations are:
5336 FreeBSD/amd64 x86_64-*-freebsd*
5337 FreeBSD/i386 i?86-*-freebsd*
5338 NetBSD/i386 i?86-*-netbsd*
5339 NetBSD/m68k m68*-*-netbsd*
5340 NetBSD/sparc sparc-*-netbsd*
5341 OpenBSD/amd64 x86_64-*-openbsd*
5342 OpenBSD/i386 i?86-*-openbsd*
5343 OpenBSD/m68k m68*-openbsd*
5344 OpenBSD/sparc sparc-*-openbsd*
5346 * Signal trampoline code overhauled
5348 Many generic problems with GDB's signal handling code have been fixed.
5349 These include: backtraces through non-contiguous stacks; recognition
5350 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5351 call; backtrace through a signal trampoline; step into and out of
5352 signal handlers; and single-stepping in the signal trampoline.
5354 Please note that kernel bugs are a limiting factor here. These
5355 features have been shown to work on an s390 GNU/Linux system that
5356 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5358 * Cygwin support for DWARF 2 added.
5360 * New native configurations
5362 GNU/Linux/hppa hppa*-*-linux*
5363 OpenBSD/hppa hppa*-*-openbsd*
5364 OpenBSD/m68k m68*-*-openbsd*
5365 OpenBSD/m88k m88*-*-openbsd*
5366 OpenBSD/powerpc powerpc-*-openbsd*
5367 NetBSD/vax vax-*-netbsd*
5368 OpenBSD/vax vax-*-openbsd*
5370 * END-OF-LIFE frame compatibility module
5372 GDB's internal frame infrastructure has been completely rewritten.
5373 The new infrastructure making it possible to support key new features
5374 including DWARF 2 Call Frame Information. To aid in the task of
5375 migrating old configurations to this new infrastructure, a
5376 compatibility module, that allowed old configurations to continue to
5377 work, was also included.
5379 GDB 6.2 will be the last release to include this frame compatibility
5380 module. This change directly impacts the following configurations:
5390 Unless there is activity to revive these configurations, they will be
5391 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5393 * REMOVED configurations and files
5395 Sun 3, running SunOS 3 m68*-*-sunos3*
5396 Sun 3, running SunOS 4 m68*-*-sunos4*
5397 Sun 2, running SunOS 3 m68000-*-sunos3*
5398 Sun 2, running SunOS 4 m68000-*-sunos4*
5399 Motorola 680x0 running LynxOS m68*-*-lynxos*
5400 AT&T 3b1/Unix pc m68*-att-*
5401 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5402 decstation mips-dec-* mips-little-*
5403 riscos mips-*-riscos* mips-*-sysv*
5404 sonymips mips-sony-*
5405 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5407 *** Changes in GDB 6.1.1:
5409 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5411 The TUI (Text-mode User Interface) is now built as part of a default
5412 GDB configuration. It is enabled by either selecting the TUI with the
5413 command line option "-i=tui" or by running the separate "gdbtui"
5414 program. For more information on the TUI, see the manual "Debugging
5417 * Pending breakpoint support (also included in GDB 6.1)
5419 Support has been added to allow you to specify breakpoints in shared
5420 libraries that have not yet been loaded. If a breakpoint location
5421 cannot be found, and the "breakpoint pending" option is set to auto,
5422 GDB queries you if you wish to make the breakpoint pending on a future
5423 shared-library load. If and when GDB resolves the breakpoint symbol,
5424 the pending breakpoint is removed as one or more regular breakpoints
5427 Pending breakpoints are very useful for GCJ Java debugging.
5429 * Fixed ISO-C build problems
5431 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5432 non ISO-C code that stopped them being built using a more strict ISO-C
5433 compiler (e.g., IBM's C compiler).
5435 * Fixed build problem on IRIX 5
5437 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5438 wasn't able to compile compile on an IRIX 5 system.
5440 * Added execute permission to gdb/gdbserver/configure
5442 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5443 permission. This bug would cause configure to fail on a number of
5444 systems (Solaris, IRIX). Ref: server/519.
5446 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5448 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5449 has been updated to use constant array sizes.
5451 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5453 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5454 its generated DWARF Call Frame Info. This encoding was causing GDB to
5455 panic, that panic has been fixed. Ref: gdb/1628.
5457 * Fixed a problem when examining parameters in shared library code.
5459 When examining parameters in optimized shared library code generated
5460 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5461 not available''. GDB now correctly displays the variable's value.
5463 *** Changes in GDB 6.1:
5465 * Removed --with-mmalloc
5467 Support for the mmalloc memory manager has been removed, as it
5468 conflicted with the internal gdb byte cache.
5470 * Changes in AMD64 configurations
5472 The AMD64 target now includes the %cs and %ss registers. As a result
5473 the AMD64 remote protocol has changed; this affects the floating-point
5474 and SSE registers. If you rely on those registers for your debugging,
5475 you should upgrade gdbserver on the remote side.
5477 * Revised SPARC target
5479 The SPARC target has been completely revised, incorporating the
5480 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5481 support for LynxOS and SunOS 4 has been dropped. Calling functions
5482 from within GDB on operating systems with a non-executable stack
5483 (Solaris, OpenBSD) now works.
5487 GDB has a new C++ demangler which does a better job on the mangled
5488 names generated by current versions of g++. It also runs faster, so
5489 with this and other changes gdb should now start faster on large C++
5492 * DWARF 2 Location Expressions
5494 GDB support for location expressions has been extended to support function
5495 arguments and frame bases. Older versions of GDB could crash when they
5498 * C++ nested types and namespaces
5500 GDB's support for nested types and namespaces in C++ has been
5501 improved, especially if you use the DWARF 2 debugging format. (This
5502 is the default for recent versions of GCC on most platforms.)
5503 Specifically, if you have a class "Inner" defined within a class or
5504 namespace "Outer", then GDB realizes that the class's name is
5505 "Outer::Inner", not simply "Inner". This should greatly reduce the
5506 frequency of complaints about not finding RTTI symbols. In addition,
5507 if you are stopped at inside of a function defined within a namespace,
5508 GDB modifies its name lookup accordingly.
5510 * New native configurations
5512 NetBSD/amd64 x86_64-*-netbsd*
5513 OpenBSD/amd64 x86_64-*-openbsd*
5514 OpenBSD/alpha alpha*-*-openbsd*
5515 OpenBSD/sparc sparc-*-openbsd*
5516 OpenBSD/sparc64 sparc64-*-openbsd*
5518 * New debugging protocols
5520 M32R with SDI protocol m32r-*-elf*
5522 * "set prompt-escape-char" command deleted.
5524 The command "set prompt-escape-char" has been deleted. This command,
5525 and its very obscure effect on GDB's prompt, was never documented,
5526 tested, nor mentioned in the NEWS file.
5528 * OBSOLETE configurations and files
5530 Configurations that have been declared obsolete in this release have
5531 been commented out. Unless there is activity to revive these
5532 configurations, the next release of GDB will have their sources
5533 permanently REMOVED.
5535 Sun 3, running SunOS 3 m68*-*-sunos3*
5536 Sun 3, running SunOS 4 m68*-*-sunos4*
5537 Sun 2, running SunOS 3 m68000-*-sunos3*
5538 Sun 2, running SunOS 4 m68000-*-sunos4*
5539 Motorola 680x0 running LynxOS m68*-*-lynxos*
5540 AT&T 3b1/Unix pc m68*-att-*
5541 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5542 decstation mips-dec-* mips-little-*
5543 riscos mips-*-riscos* mips-*-sysv*
5544 sonymips mips-sony-*
5545 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5547 * REMOVED configurations and files
5549 SGI Irix-4.x mips-sgi-irix4 or iris4
5550 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5551 Z8000 simulator z8k-zilog-none or z8ksim
5552 Matsushita MN10200 w/simulator mn10200-*-*
5553 H8/500 simulator h8500-hitachi-hms or h8500hms
5554 HP/PA running BSD hppa*-*-bsd*
5555 HP/PA running OSF/1 hppa*-*-osf*
5556 HP/PA Pro target hppa*-*-pro*
5557 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5558 386BSD i[3456]86-*-bsd*
5559 Sequent family i[3456]86-sequent-sysv4*
5560 i[3456]86-sequent-sysv*
5561 i[3456]86-sequent-bsd*
5562 SPARC running LynxOS sparc-*-lynxos*
5563 SPARC running SunOS 4 sparc-*-sunos4*
5564 Tsqware Sparclet sparclet-*-*
5565 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5567 *** Changes in GDB 6.0:
5571 Support for debugging the Objective-C programming language has been
5572 integrated into GDB.
5574 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5576 DWARF 2's Call Frame Information makes available compiler generated
5577 information that more exactly describes the program's run-time stack.
5578 By using this information, GDB is able to provide more robust stack
5581 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5582 have been updated to use a new backtrace mechanism which includes
5583 DWARF 2 CFI support.
5587 GDB's remote protocol has been extended to include support for hosted
5588 file I/O (where the remote target uses GDB's file system). See GDB's
5589 remote protocol documentation for details.
5591 * All targets using the new architecture framework.
5593 All of GDB's targets have been updated to use the new internal
5594 architecture framework. The way is now open for future GDB releases
5595 to include cross-architecture native debugging support (i386 on amd64,
5598 * GNU/Linux's Thread Local Storage (TLS)
5600 GDB now includes support for for the GNU/Linux implementation of
5601 per-thread variables.
5603 * GNU/Linux's Native POSIX Thread Library (NPTL)
5605 GDB's thread code has been updated to work with either the new
5606 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5608 * Separate debug info.
5610 GDB, in conjunction with BINUTILS, now supports a mechanism for
5611 automatically loading debug information from a separate file. Instead
5612 of shipping full debug and non-debug versions of system libraries,
5613 system integrators can now instead ship just the stripped libraries
5614 and optional debug files.
5616 * DWARF 2 Location Expressions
5618 DWARF 2 Location Expressions allow the compiler to more completely
5619 describe the location of variables (even in optimized code) to the
5622 GDB now includes preliminary support for location expressions (support
5623 for DW_OP_piece is still missing).
5627 A number of long standing bugs that caused GDB to die while starting a
5628 Java application have been fixed. GDB's Java support is now
5629 considered "useable".
5631 * GNU/Linux support for fork, vfork, and exec.
5633 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5634 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5637 * GDB supports logging output to a file
5639 There are two new commands, "set logging" and "show logging", which can be
5640 used to capture GDB's output to a file.
5642 * The meaning of "detach" has changed for gdbserver
5644 The "detach" command will now resume the application, as documented. To
5645 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5648 * d10v, m68hc11 `regs' command deprecated
5650 The `info registers' command has been updated so that it displays the
5651 registers using a format identical to the old `regs' command.
5655 A new command, "maint set profile on/off", has been added. This command can
5656 be used to enable or disable profiling while running GDB, to profile a
5657 session or a set of commands. In addition there is a new configure switch,
5658 "--enable-profiling", which will cause GDB to be compiled with profiling
5659 data, for more informative profiling results.
5661 * Default MI syntax changed to "mi2".
5663 The default MI (machine interface) syntax, enabled by the command line
5664 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5665 "mi1", can be enabled by specifying the option "-i=mi1".
5667 Support for the original "mi0" syntax (included in GDB 5.0) has been
5670 Fix for gdb/192: removed extraneous space when displaying frame level.
5671 Fix for gdb/672: update changelist is now output in mi list format.
5672 Fix for gdb/702: a -var-assign that updates the value now shows up
5673 in a subsequent -var-update.
5675 * New native configurations.
5677 FreeBSD/amd64 x86_64-*-freebsd*
5679 * Multi-arched targets.
5681 HP/PA HPUX11 hppa*-*-hpux*
5682 Renesas M32R/D w/simulator m32r-*-elf*
5684 * OBSOLETE configurations and files
5686 Configurations that have been declared obsolete in this release have
5687 been commented out. Unless there is activity to revive these
5688 configurations, the next release of GDB will have their sources
5689 permanently REMOVED.
5691 Z8000 simulator z8k-zilog-none or z8ksim
5692 Matsushita MN10200 w/simulator mn10200-*-*
5693 H8/500 simulator h8500-hitachi-hms or h8500hms
5694 HP/PA running BSD hppa*-*-bsd*
5695 HP/PA running OSF/1 hppa*-*-osf*
5696 HP/PA Pro target hppa*-*-pro*
5697 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5698 Sequent family i[3456]86-sequent-sysv4*
5699 i[3456]86-sequent-sysv*
5700 i[3456]86-sequent-bsd*
5701 Tsqware Sparclet sparclet-*-*
5702 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5704 * REMOVED configurations and files
5707 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5708 IBM AIX PS/2 i[3456]86-*-aix
5709 i386 running Mach 3.0 i[3456]86-*-mach3*
5710 i386 running Mach i[3456]86-*-mach*
5711 i386 running OSF/1 i[3456]86-*osf1mk*
5712 HP/Apollo 68k Family m68*-apollo*-sysv*,
5714 m68*-hp-bsd*, m68*-hp-hpux*
5715 Argonaut Risc Chip (ARC) arc-*-*
5716 Mitsubishi D30V d30v-*-*
5717 Fujitsu FR30 fr30-*-elf*
5718 OS/9000 i[34]86-*-os9k
5719 I960 with MON960 i960-*-coff
5721 * MIPS $fp behavior changed
5723 The convenience variable $fp, for the MIPS, now consistently returns
5724 the address of the current frame's base. Previously, depending on the
5725 context, $fp could refer to either $sp or the current frame's base
5726 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5727 The GNU Source-Level Debugger''.
5729 *** Changes in GDB 5.3:
5731 * GNU/Linux shared library multi-threaded performance improved.
5733 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5734 `/proc', in preference to `ptrace' for memory reads. This may result
5735 in an improvement in the start-up time of multi-threaded, shared
5736 library applications when run under GDB. One GDB user writes: ``loads
5737 shared libs like mad''.
5739 * ``gdbserver'' now supports multi-threaded applications on some targets
5741 Support for debugging multi-threaded applications which use
5742 the GNU/Linux LinuxThreads package has been added for
5743 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5744 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5746 * GDB now supports C/C++ preprocessor macros.
5748 GDB now expands preprocessor macro invocations in C/C++ expressions,
5749 and provides various commands for showing macro definitions and how
5752 The new command `macro expand EXPRESSION' expands any macro
5753 invocations in expression, and shows the result.
5755 The new command `show macro MACRO-NAME' shows the definition of the
5756 macro named MACRO-NAME, and where it was defined.
5758 Most compilers don't include information about macros in the debugging
5759 information by default. In GCC 3.1, for example, you need to compile
5760 your program with the options `-gdwarf-2 -g3'. If the macro
5761 information is present in the executable, GDB will read it.
5763 * Multi-arched targets.
5765 DEC Alpha (partial) alpha*-*-*
5766 DEC VAX (partial) vax-*-*
5768 National Semiconductor NS32000 (partial) ns32k-*-*
5769 Motorola 68000 (partial) m68k-*-*
5770 Motorola MCORE mcore-*-*
5774 Fujitsu FRV architecture added by Red Hat frv*-*-*
5777 * New native configurations
5779 Alpha NetBSD alpha*-*-netbsd*
5780 SH NetBSD sh*-*-netbsdelf*
5781 MIPS NetBSD mips*-*-netbsd*
5782 UltraSPARC NetBSD sparc64-*-netbsd*
5784 * OBSOLETE configurations and files
5786 Configurations that have been declared obsolete in this release have
5787 been commented out. Unless there is activity to revive these
5788 configurations, the next release of GDB will have their sources
5789 permanently REMOVED.
5791 Mitsubishi D30V d30v-*-*
5792 OS/9000 i[34]86-*-os9k
5793 IBM AIX PS/2 i[3456]86-*-aix
5794 Fujitsu FR30 fr30-*-elf*
5795 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5796 Argonaut Risc Chip (ARC) arc-*-*
5797 i386 running Mach 3.0 i[3456]86-*-mach3*
5798 i386 running Mach i[3456]86-*-mach*
5799 i386 running OSF/1 i[3456]86-*osf1mk*
5800 HP/Apollo 68k Family m68*-apollo*-sysv*,
5802 m68*-hp-bsd*, m68*-hp-hpux*
5803 I960 with MON960 i960-*-coff
5805 * OBSOLETE languages
5807 CHILL, a Pascal like language used by telecommunications companies.
5809 * REMOVED configurations and files
5811 AMD 29k family via UDI a29k-amd-udi, udi29k
5812 A29K VxWorks a29k-*-vxworks
5813 AMD 29000 embedded, using EBMON a29k-none-none
5814 AMD 29000 embedded with COFF a29k-none-coff
5815 AMD 29000 embedded with a.out a29k-none-aout
5817 testsuite/gdb.hp/gdb.threads-hp/ directory
5819 * New command "set max-user-call-depth <nnn>"
5821 This command allows the user to limit the call depth of user-defined
5822 commands. The default is 1024.
5824 * Changes in FreeBSD/i386 native debugging.
5826 Support for the "generate-core-file" has been added.
5828 * New commands "dump", "append", and "restore".
5830 These commands allow data to be copied from target memory
5831 to a bfd-format or binary file (dump and append), and back
5832 from a file into memory (restore).
5834 * Improved "next/step" support on multi-processor Alpha Tru64.
5836 The previous single-step mechanism could cause unpredictable problems,
5837 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5838 of a software single-step mechanism prevents this.
5840 *** Changes in GDB 5.2.1:
5848 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5849 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5850 Fix, by Joel Brobecker imported from mainline.
5852 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5853 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5854 Fix, by Fred Fish, imported from mainline.
5856 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5857 Surprisingly enough, it works now.
5858 By Michal Ludvig, imported from mainline.
5860 i386 hardware watchpoint support:
5861 avoid misses on second run for some targets.
5862 By Pierre Muller, imported from mainline.
5864 *** Changes in GDB 5.2:
5866 * New command "set trust-readonly-sections on[off]".
5868 This command is a hint that tells gdb that read-only sections
5869 really are read-only (ie. that their contents will not change).
5870 In this mode, gdb will go to the object file rather than the
5871 target to read memory from read-only sections (such as ".text").
5872 This can be a significant performance improvement on some
5873 (notably embedded) targets.
5875 * New command "generate-core-file" (or "gcore").
5877 This new gdb command allows the user to drop a core file of the child
5878 process state at any time. So far it's been implemented only for
5879 GNU/Linux and Solaris, but should be relatively easily ported to other
5880 hosts. Argument is core file name (defaults to core.<pid>).
5882 * New command line option
5884 GDB now accepts --pid or -p followed by a process id.
5886 * Change in command line behavior -- corefiles vs. process ids.
5888 There is a subtle behavior in the way in which GDB handles
5889 command line arguments. The first non-flag argument is always
5890 a program to debug, but the second non-flag argument may either
5891 be a corefile or a process id. Previously, GDB would attempt to
5892 open the second argument as a corefile, and if that failed, would
5893 issue a superfluous error message and then attempt to attach it as
5894 a process. Now, if the second argument begins with a non-digit,
5895 it will be treated as a corefile. If it begins with a digit,
5896 GDB will attempt to attach it as a process, and if no such process
5897 is found, will then attempt to open it as a corefile.
5899 * Changes in ARM configurations.
5901 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5902 configuration is fully multi-arch.
5904 * New native configurations
5906 ARM NetBSD arm*-*-netbsd*
5907 x86 OpenBSD i[3456]86-*-openbsd*
5908 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5909 Sparc64 running FreeBSD sparc64-*-freebsd*
5913 Sanyo XStormy16 xstormy16-elf
5915 * OBSOLETE configurations and files
5917 Configurations that have been declared obsolete in this release have
5918 been commented out. Unless there is activity to revive these
5919 configurations, the next release of GDB will have their sources
5920 permanently REMOVED.
5922 AMD 29k family via UDI a29k-amd-udi, udi29k
5923 A29K VxWorks a29k-*-vxworks
5924 AMD 29000 embedded, using EBMON a29k-none-none
5925 AMD 29000 embedded with COFF a29k-none-coff
5926 AMD 29000 embedded with a.out a29k-none-aout
5928 testsuite/gdb.hp/gdb.threads-hp/ directory
5930 * REMOVED configurations and files
5932 TI TMS320C80 tic80-*-*
5934 PowerPC Solaris powerpcle-*-solaris*
5935 PowerPC Windows NT powerpcle-*-cygwin32
5936 PowerPC Netware powerpc-*-netware*
5937 Harris/CXUX m88k m88*-harris-cxux*
5938 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5939 ns32k-utek-sysv* ns32k-utek-*
5940 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5941 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5942 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5943 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5944 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5946 * Changes to command line processing
5948 The new `--args' feature can be used to specify command-line arguments
5949 for the inferior from gdb's command line.
5951 * Changes to key bindings
5953 There is a new `operate-and-get-next' function bound to `C-o'.
5955 *** Changes in GDB 5.1.1
5957 Fix compile problem on DJGPP.
5959 Fix a problem with floating-point registers on the i386 being
5962 Fix to stop GDB crashing on .debug_str debug info.
5964 Numerous documentation fixes.
5966 Numerous testsuite fixes.
5968 *** Changes in GDB 5.1:
5970 * New native configurations
5972 Alpha FreeBSD alpha*-*-freebsd*
5973 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5974 MIPS GNU/Linux mips*-*-linux*
5975 MIPS SGI Irix 6.x mips*-sgi-irix6*
5976 ia64 AIX ia64-*-aix*
5977 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5981 Motorola 68HC11 and 68HC12 m68hc11-elf
5983 UltraSparc running GNU/Linux sparc64-*-linux*
5985 * OBSOLETE configurations and files
5987 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5988 Harris/CXUX m88k m88*-harris-cxux*
5989 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5990 ns32k-utek-sysv* ns32k-utek-*
5991 TI TMS320C80 tic80-*-*
5993 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5994 PowerPC Solaris powerpcle-*-solaris*
5995 PowerPC Windows NT powerpcle-*-cygwin32
5996 PowerPC Netware powerpc-*-netware*
5997 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5998 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5999 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6000 Apple Macintosh (MPW) host N/A
6002 stuff.c (Program to stuff files into a specially prepared space in kdb)
6003 kdb-start.c (Main loop for the standalone kernel debugger)
6005 Configurations that have been declared obsolete in this release have
6006 been commented out. Unless there is activity to revive these
6007 configurations, the next release of GDB will have their sources
6008 permanently REMOVED.
6010 * REMOVED configurations and files
6012 Altos 3068 m68*-altos-*
6013 Convex c1-*-*, c2-*-*
6015 ARM RISCix arm-*-* (as host)
6019 * GDB has been converted to ISO C.
6021 GDB's source code has been converted to ISO C. In particular, the
6022 sources are fully protoized, and rely on standard headers being
6027 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6029 * The MI enabled by default.
6031 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6032 revised and enabled by default. Packages which use GDB as a debugging
6033 engine behind a UI or another front end are encouraged to switch to
6034 using the GDB/MI interface, instead of the old annotations interface
6035 which is now deprecated.
6037 * Support for debugging Pascal programs.
6039 GDB now includes support for debugging Pascal programs. The following
6040 main features are supported:
6042 - Pascal-specific data types such as sets;
6044 - automatic recognition of Pascal sources based on file-name
6047 - Pascal-style display of data types, variables, and functions;
6049 - a Pascal expression parser.
6051 However, some important features are not yet supported.
6053 - Pascal string operations are not supported at all;
6055 - there are some problems with boolean types;
6057 - Pascal type hexadecimal constants are not supported
6058 because they conflict with the internal variables format;
6060 - support for Pascal objects and classes is not full yet;
6062 - unlike Pascal, GDB is case-sensitive for symbol names.
6064 * Changes in completion.
6066 Commands such as `shell', `run' and `set args', which pass arguments
6067 to inferior programs, now complete on file names, similar to what
6068 users expect at the shell prompt.
6070 Commands which accept locations, such as `disassemble', `print',
6071 `breakpoint', `until', etc. now complete on filenames as well as
6072 program symbols. Thus, if you type "break foob TAB", and the source
6073 files linked into the programs include `foobar.c', that file name will
6074 be one of the candidates for completion. However, file names are not
6075 considered for completion after you typed a colon that delimits a file
6076 name from a name of a function in that file, as in "break foo.c:bar".
6078 `set demangle-style' completes on available demangling styles.
6080 * New platform-independent commands:
6082 It is now possible to define a post-hook for a command as well as a
6083 hook that runs before the command. For more details, see the
6084 documentation of `hookpost' in the GDB manual.
6086 * Changes in GNU/Linux native debugging.
6088 Support for debugging multi-threaded programs has been completely
6089 revised for all platforms except m68k and sparc. You can now debug as
6090 many threads as your system allows you to have.
6092 Attach/detach is supported for multi-threaded programs.
6094 Support for SSE registers was added for x86. This doesn't work for
6095 multi-threaded programs though.
6097 * Changes in MIPS configurations.
6099 Multi-arch support is enabled for all MIPS configurations.
6101 GDB can now be built as native debugger on SGI Irix 6.x systems for
6102 debugging n32 executables. (Debugging 64-bit executables is not yet
6105 * Unified support for hardware watchpoints in all x86 configurations.
6107 Most (if not all) native x86 configurations support hardware-assisted
6108 breakpoints and watchpoints in a unified manner. This support
6109 implements debug register sharing between watchpoints, which allows to
6110 put a virtually infinite number of watchpoints on the same address,
6111 and also supports watching regions up to 16 bytes with several debug
6114 The new maintenance command `maintenance show-debug-regs' toggles
6115 debugging print-outs in functions that insert, remove, and test
6116 watchpoints and hardware breakpoints.
6118 * Changes in the DJGPP native configuration.
6120 New command ``info dos sysinfo'' displays assorted information about
6121 the CPU, OS, memory, and DPMI server.
6123 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6124 display information about segment descriptors stored in GDT, LDT, and
6127 New commands ``info dos pde'' and ``info dos pte'' display entries
6128 from Page Directory and Page Tables (for now works with CWSDPMI only).
6129 New command ``info dos address-pte'' displays the Page Table entry for
6130 a given linear address.
6132 GDB can now pass command lines longer than 126 characters to the
6133 program being debugged (requires an update to the libdbg.a library
6134 which is part of the DJGPP development kit).
6136 DWARF2 debug info is now supported.
6138 It is now possible to `step' and `next' through calls to `longjmp'.
6140 * Changes in documentation.
6142 All GDB documentation was converted to GFDL, the GNU Free
6143 Documentation License.
6145 Tracepoints-related commands are now fully documented in the GDB
6148 TUI, the Text-mode User Interface, is now documented in the manual.
6150 Tracepoints-related commands are now fully documented in the GDB
6153 The "GDB Internals" manual now has an index. It also includes
6154 documentation of `ui_out' functions, GDB coding standards, x86
6155 hardware watchpoints, and memory region attributes.
6157 * GDB's version number moved to ``version.in''
6159 The Makefile variable VERSION has been replaced by the file
6160 ``version.in''. People creating GDB distributions should update the
6161 contents of this file.
6165 GUD support is now a standard part of the EMACS distribution.
6167 *** Changes in GDB 5.0:
6169 * Improved support for debugging FP programs on x86 targets
6171 Unified and much-improved support for debugging floating-point
6172 programs on all x86 targets. In particular, ``info float'' now
6173 displays the FP registers in the same format on all x86 targets, with
6174 greater level of detail.
6176 * Improvements and bugfixes in hardware-assisted watchpoints
6178 It is now possible to watch array elements, struct members, and
6179 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6180 on x86 targets no longer erroneously trigger when the address is
6183 * Improvements in the native DJGPP version of GDB
6185 The distribution now includes all the scripts and auxiliary files
6186 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6187 machines ``out of the box''.
6189 The DJGPP version can now debug programs that use signals. It is
6190 possible to catch signals that happened in the debuggee, deliver
6191 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6192 would kill the program being debugged.) Programs that hook hardware
6193 interrupts (keyboard, timer, etc.) can also be debugged.
6195 It is now possible to debug DJGPP programs that redirect their
6196 standard handles or switch them to raw (as opposed to cooked) mode, or
6197 even close them. The command ``run < foo > bar'' works as expected,
6198 and ``info terminal'' reports useful information about the debuggee's
6199 terminal, including raw/cooked mode, redirection, etc.
6201 The DJGPP version now uses termios functions for console I/O, which
6202 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6205 DOS-style file names with drive letters are now fully supported by
6208 It is now possible to debug DJGPP programs that switch their working
6209 directory. It is also possible to rerun the debuggee any number of
6210 times without restarting GDB; thus, you can use the same setup,
6211 breakpoints, etc. for many debugging sessions.
6213 * New native configurations
6215 ARM GNU/Linux arm*-*-linux*
6216 PowerPC GNU/Linux powerpc-*-linux*
6220 Motorola MCore mcore-*-*
6221 x86 VxWorks i[3456]86-*-vxworks*
6222 PowerPC VxWorks powerpc-*-vxworks*
6223 TI TMS320C80 tic80-*-*
6225 * OBSOLETE configurations
6227 Altos 3068 m68*-altos-*
6228 Convex c1-*-*, c2-*-*
6230 ARM RISCix arm-*-* (as host)
6233 Configurations that have been declared obsolete will be commented out,
6234 but the code will be left in place. If there is no activity to revive
6235 these configurations before the next release of GDB, the sources will
6236 be permanently REMOVED.
6238 * Gould support removed
6240 Support for the Gould PowerNode and NP1 has been removed.
6242 * New features for SVR4
6244 On SVR4 native platforms (such as Solaris), if you attach to a process
6245 without first loading a symbol file, GDB will now attempt to locate and
6246 load symbols from the running process's executable file.
6248 * Many C++ enhancements
6250 C++ support has been greatly improved. Overload resolution now works properly
6251 in almost all cases. RTTI support is on the way.
6253 * Remote targets can connect to a sub-program
6255 A popen(3) style serial-device has been added. This device starts a
6256 sub-process (such as a stand-alone simulator) and then communicates
6257 with that. The sub-program to run is specified using the syntax
6258 ``|<program> <args>'' vis:
6260 (gdb) set remotedebug 1
6261 (gdb) target extended-remote |mn10300-elf-sim program-args
6263 * MIPS 64 remote protocol
6265 A long standing bug in the mips64 remote protocol where by GDB
6266 expected certain 32 bit registers (ex SR) to be transfered as 32
6267 instead of 64 bits has been fixed.
6269 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6270 added to provide backward compatibility with older versions of GDB.
6272 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6274 The command ``set remotebinarydownload'' command has been replaced by
6275 ``set remote X-packet''. Other commands in ``set remote'' family
6276 include ``set remote P-packet''.
6278 * Breakpoint commands accept ranges.
6280 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6281 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6282 ``tracepoint passcount'' also accepts a range of tracepoints.
6284 * ``apropos'' command added.
6286 The ``apropos'' command searches through command names and
6287 documentation strings, printing out matches, making it much easier to
6288 try to find a command that does what you are looking for.
6292 A new machine oriented interface (MI) has been added to GDB. This
6293 interface is designed for debug environments running GDB as a separate
6294 process. This is part of the long term libGDB project. See the
6295 "GDB/MI" chapter of the GDB manual for further information. It can be
6296 enabled by configuring with:
6298 .../configure --enable-gdbmi
6300 *** Changes in GDB-4.18:
6302 * New native configurations
6304 HP-UX 10.20 hppa*-*-hpux10.20
6305 HP-UX 11.x hppa*-*-hpux11.0*
6306 M68K GNU/Linux m68*-*-linux*
6310 Fujitsu FR30 fr30-*-elf*
6311 Intel StrongARM strongarm-*-*
6312 Mitsubishi D30V d30v-*-*
6314 * OBSOLETE configurations
6316 Gould PowerNode, NP1 np1-*-*, pn-*-*
6318 Configurations that have been declared obsolete will be commented out,
6319 but the code will be left in place. If there is no activity to revive
6320 these configurations before the next release of GDB, the sources will
6321 be permanently REMOVED.
6325 As a compatibility experiment, GDB's source files buildsym.h and
6326 buildsym.c have been converted to pure standard C, no longer
6327 containing any K&R compatibility code. We believe that all systems in
6328 use today either come with a standard C compiler, or have a GCC port
6329 available. If this is not true, please report the affected
6330 configuration to bug-gdb@gnu.org immediately. See the README file for
6331 information about getting a standard C compiler if you don't have one
6336 GDB now uses readline 2.2.
6338 * set extension-language
6340 You can now control the mapping between filename extensions and source
6341 languages by using the `set extension-language' command. For instance,
6342 you can ask GDB to treat .c files as C++ by saying
6343 set extension-language .c c++
6344 The command `info extensions' lists all of the recognized extensions
6345 and their associated languages.
6347 * Setting processor type for PowerPC and RS/6000
6349 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6350 you can use the `set processor' command to specify what variant of the
6351 PowerPC family you are debugging. The command
6355 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6356 following PowerPC and RS6000 variants:
6358 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6359 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6361 403GC IBM PowerPC 403GC
6362 505 Motorola PowerPC 505
6363 860 Motorola PowerPC 860 or 850
6364 601 Motorola PowerPC 601
6365 602 Motorola PowerPC 602
6366 603 Motorola/IBM PowerPC 603 or 603e
6367 604 Motorola PowerPC 604 or 604e
6368 750 Motorola/IBM PowerPC 750 or 750
6370 At the moment, this command just tells GDB what to name the
6371 special-purpose processor registers. Since almost all the affected
6372 registers are inaccessible to user-level programs, this command is
6373 only useful for remote debugging in its present form.
6377 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6378 more extensive support for HP-UX. Added features include shared
6379 library support, kernel threads and hardware watchpoints for 11.00,
6380 support for HP's ANSI C and C++ compilers, and a compatibility mode
6381 for xdb and dbx commands.
6385 HP's donation includes the new concept of catchpoints, which is a
6386 generalization of the old catch command. On HP-UX, it is now possible
6387 to catch exec, fork, and vfork, as well as library loading.
6389 This means that the existing catch command has changed; its first
6390 argument now specifies the type of catch to be set up. See the
6391 output of "help catch" for a list of catchpoint types.
6393 * Debugging across forks
6395 On HP-UX, you can choose which process to debug when a fork() happens
6400 HP has donated a curses-based terminal user interface (TUI). To get
6401 it, build with --enable-tui. Although this can be enabled for any
6402 configuration, at present it only works for native HP debugging.
6404 * GDB remote protocol additions
6406 A new protocol packet 'X' that writes binary data is now available.
6407 Default behavior is to try 'X', then drop back to 'M' if the stub
6408 fails to respond. The settable variable `remotebinarydownload'
6409 allows explicit control over the use of 'X'.
6411 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6412 full 64-bit address. The command
6414 set remoteaddresssize 32
6416 can be used to revert to the old behaviour. For existing remote stubs
6417 the change should not be noticed, as the additional address information
6420 In order to assist in debugging stubs, you may use the maintenance
6421 command `packet' to send any text string to the stub. For instance,
6423 maint packet heythere
6425 sends the packet "$heythere#<checksum>". Note that it is very easy to
6426 disrupt a debugging session by sending the wrong packet at the wrong
6429 The compare-sections command allows you to compare section data on the
6430 target to what is in the executable file without uploading or
6431 downloading, by comparing CRC checksums.
6433 * Tracing can collect general expressions
6435 You may now collect general expressions at tracepoints. This requires
6436 further additions to the target-side stub; see tracepoint.c and
6437 doc/agentexpr.texi for further details.
6439 * mask-address variable for Mips
6441 For Mips targets, you may control the zeroing of the upper 32 bits of
6442 a 64-bit address by entering `set mask-address on'. This is mainly
6443 of interest to users of embedded R4xxx and R5xxx processors.
6445 * Higher serial baud rates
6447 GDB's serial code now allows you to specify baud rates 57600, 115200,
6448 230400, and 460800 baud. (Note that your host system may not be able
6449 to achieve all of these rates.)
6453 The i960 configuration now includes an initial implementation of a
6454 builtin simulator, contributed by Jim Wilson.
6457 *** Changes in GDB-4.17:
6459 * New native configurations
6461 Alpha GNU/Linux alpha*-*-linux*
6462 Unixware 2.x i[3456]86-unixware2*
6463 Irix 6.x mips*-sgi-irix6*
6464 PowerPC GNU/Linux powerpc-*-linux*
6465 PowerPC Solaris powerpcle-*-solaris*
6466 Sparc GNU/Linux sparc-*-linux*
6467 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6471 Argonaut Risc Chip (ARC) arc-*-*
6472 Hitachi H8/300S h8300*-*-*
6473 Matsushita MN10200 w/simulator mn10200-*-*
6474 Matsushita MN10300 w/simulator mn10300-*-*
6475 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6476 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6477 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6478 Mitsubishi D10V w/simulator d10v-*-*
6479 Mitsubishi M32R/D w/simulator m32r-*-elf*
6480 Tsqware Sparclet sparclet-*-*
6481 NEC V850 w/simulator v850-*-*
6483 * New debugging protocols
6485 ARM with RDI protocol arm*-*-*
6486 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6487 DDB and LSI variants of PMON protocol mips*-*-*
6488 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6489 PowerPC with SDS protocol powerpc{,le}-*-eabi
6490 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6494 All configurations can now understand and use the DWARF 2 debugging
6495 format. The choice is automatic, if the symbol file contains DWARF 2
6500 GDB now includes basic Java language support. This support is
6501 only useful with Java compilers that produce native machine code.
6503 * solib-absolute-prefix and solib-search-path
6505 For SunOS and SVR4 shared libraries, you may now set the prefix for
6506 loading absolute shared library symbol files, and the search path for
6507 locating non-absolute shared library symbol files.
6509 * Live range splitting
6511 GDB can now effectively debug code for which GCC has performed live
6512 range splitting as part of its optimization. See gdb/doc/LRS for
6513 more details on the expected format of the stabs information.
6517 GDB's support for the GNU Hurd, including thread debugging, has been
6518 updated to work with current versions of the Hurd.
6522 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6523 instruction set. ARM GDB automatically detects when Thumb
6524 instructions are in use, and adjusts disassembly and backtracing
6529 GDB's MIPS target configurations now handle the MIP16 16-bit
6534 GDB now includes support for overlays; if an executable has been
6535 linked such that multiple sections are based at the same address, GDB
6536 will decide which section to use for symbolic info. You can choose to
6537 control the decision manually, using overlay commands, or implement
6538 additional target-side support and use "overlay load-target" to bring
6539 in the overlay mapping. Do "help overlay" for more detail.
6543 The command "info symbol <address>" displays information about
6544 the symbol at the specified address.
6548 The standard remote protocol now includes an extension that allows
6549 asynchronous collection and display of trace data. This requires
6550 extensive support in the target-side debugging stub. Tracing mode
6551 includes a new interaction mode in GDB and new commands: see the
6552 file tracepoint.c for more details.
6556 Configurations for embedded MIPS now include a simulator contributed
6557 by Cygnus Solutions. The simulator supports the instruction sets
6558 of most MIPS variants.
6562 Sparc configurations may now include the ERC32 simulator contributed
6563 by the European Space Agency. The simulator is not built into
6564 Sparc targets by default; configure with --enable-sim to include it.
6568 For target configurations that may include multiple variants of a
6569 basic architecture (such as MIPS and SH), you may now set the
6570 architecture explicitly. "set arch" sets, "info arch" lists
6571 the possible architectures.
6573 *** Changes in GDB-4.16:
6575 * New native configurations
6577 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6578 M68K NetBSD m68k-*-netbsd*
6579 PowerPC AIX 4.x powerpc-*-aix*
6580 PowerPC MacOS powerpc-*-macos*
6581 PowerPC Windows NT powerpcle-*-cygwin32
6582 RS/6000 AIX 4.x rs6000-*-aix4*
6586 ARM with RDP protocol arm-*-*
6587 I960 with MON960 i960-*-coff
6588 MIPS VxWorks mips*-*-vxworks*
6589 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6590 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6592 Matra Sparclet sparclet-*-*
6596 The powerpc-eabi configuration now includes the PSIM simulator,
6597 contributed by Andrew Cagney, with assistance from Mike Meissner.
6598 PSIM is a very elaborate model of the PowerPC, including not only
6599 basic instruction set execution, but also details of execution unit
6600 performance and I/O hardware. See sim/ppc/README for more details.
6604 GDB now works with Solaris 2.5.
6606 * Windows 95/NT native
6608 GDB will now work as a native debugger on Windows 95 and Windows NT.
6609 To build it from source, you must use the "gnu-win32" environment,
6610 which uses a DLL to emulate enough of Unix to run the GNU tools.
6611 Further information, binaries, and sources are available at
6612 ftp.cygnus.com, under pub/gnu-win32.
6614 * dont-repeat command
6616 If a user-defined command includes the command `dont-repeat', then the
6617 command will not be repeated if the user just types return. This is
6618 useful if the command is time-consuming to run, so that accidental
6619 extra keystrokes don't run the same command many times.
6621 * Send break instead of ^C
6623 The standard remote protocol now includes an option to send a break
6624 rather than a ^C to the target in order to interrupt it. By default,
6625 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6627 * Remote protocol timeout
6629 The standard remote protocol includes a new variable `remotetimeout'
6630 that allows you to set the number of seconds before GDB gives up trying
6631 to read from the target. The default value is 2.
6633 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6635 By default GDB will automatically keep track of objects as they are
6636 loaded and unloaded by the dynamic linker. By using the command `set
6637 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6638 when shared library events occur, thus allowing you to set breakpoints
6639 in shared libraries which are explicitly loaded by the inferior.
6641 Note this feature does not work on hpux8. On hpux9 you must link
6642 /usr/lib/end.o into your program. This feature should work
6643 automatically on hpux10.
6645 * Irix 5.x hardware watchpoint support
6647 Irix 5 configurations now support the use of hardware watchpoints.
6649 * Mips protocol "SYN garbage limit"
6651 When debugging a Mips target using the `target mips' protocol, you
6652 may set the number of characters that GDB will ignore by setting
6653 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6654 every character. The default value is 1050.
6656 * Recording and replaying remote debug sessions
6658 If you set `remotelogfile' to the name of a file, gdb will write to it
6659 a recording of a remote debug session. This recording may then be
6660 replayed back to gdb using "gdbreplay". See gdbserver/README for
6661 details. This is useful when you have a problem with GDB while doing
6662 remote debugging; you can make a recording of the session and send it
6663 to someone else, who can then recreate the problem.
6665 * Speedups for remote debugging
6667 GDB includes speedups for downloading and stepping MIPS systems using
6668 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6669 and more efficient S-record downloading.
6671 * Memory use reductions and statistics collection
6673 GDB now uses less memory and reports statistics about memory usage.
6674 Try the `maint print statistics' command, for example.
6676 *** Changes in GDB-4.15:
6678 * Psymtabs for XCOFF
6680 The symbol reader for AIX GDB now uses partial symbol tables. This
6681 can greatly improve startup time, especially for large executables.
6683 * Remote targets use caching
6685 Remote targets now use a data cache to speed up communication with the
6686 remote side. The data cache could lead to incorrect results because
6687 it doesn't know about volatile variables, thus making it impossible to
6688 debug targets which use memory mapped I/O devices. `set remotecache
6689 off' turns the data cache off.
6691 * Remote targets may have threads
6693 The standard remote protocol now includes support for multiple threads
6694 in the target system, using new protocol commands 'H' and 'T'. See
6695 gdb/remote.c for details.
6699 If GDB is configured with `--enable-netrom', then it will include
6700 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6701 acts as though it is a bank of ROM on the target board, but you can
6702 write into it over the network. GDB's support consists only of
6703 support for fast loading into the emulated ROM; to debug, you must use
6704 another protocol, such as standard remote protocol. The usual
6705 sequence is something like
6707 target nrom <netrom-hostname>
6709 target remote <netrom-hostname>:1235
6713 GDB now includes support for the Apple Macintosh, as a host only. It
6714 may be run as either an MPW tool or as a standalone application, and
6715 it can debug through the serial port. All the usual GDB commands are
6716 available, but to the target command, you must supply "serial" as the
6717 device type instead of "/dev/ttyXX". See mpw-README in the main
6718 directory for more information on how to build. The MPW configuration
6719 scripts */mpw-config.in support only a few targets, and only the
6720 mips-idt-ecoff target has been tested.
6724 GDB configuration now uses autoconf. This is not user-visible,
6725 but does simplify configuration and building.
6729 GDB now supports hpux10.
6731 *** Changes in GDB-4.14:
6733 * New native configurations
6735 x86 FreeBSD i[345]86-*-freebsd
6736 x86 NetBSD i[345]86-*-netbsd
6737 NS32k NetBSD ns32k-*-netbsd
6738 Sparc NetBSD sparc-*-netbsd
6742 A29K VxWorks a29k-*-vxworks
6743 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6744 CPU32 EST-300 emulator m68*-*-est*
6745 PowerPC ELF powerpc-*-elf
6748 * Alpha OSF/1 support for procfs
6750 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6751 possible to attach to running processes. As the mounting of the /proc
6752 filesystem is optional on the Alpha, GDB automatically determines
6753 the availability of /proc during startup. This can lead to problems
6754 if /proc is unmounted after GDB has been started.
6756 * Arguments to user-defined commands
6758 User commands may accept up to 10 arguments separated by whitespace.
6759 Arguments are accessed within the user command via $arg0..$arg9. A
6762 print $arg0 + $arg1 + $arg2
6764 To execute the command use:
6767 Defines the command "adder" which prints the sum of its three arguments.
6768 Note the arguments are text substitutions, so they may reference variables,
6769 use complex expressions, or even perform inferior function calls.
6771 * New `if' and `while' commands
6773 This makes it possible to write more sophisticated user-defined
6774 commands. Both commands take a single argument, which is the
6775 expression to evaluate, and must be followed by the commands to
6776 execute, one per line, if the expression is nonzero, the list being
6777 terminated by the word `end'. The `if' command list may include an
6778 `else' word, which causes the following commands to be executed only
6779 if the expression is zero.
6781 * Fortran source language mode
6783 GDB now includes partial support for Fortran 77. It will recognize
6784 Fortran programs and can evaluate a subset of Fortran expressions, but
6785 variables and functions may not be handled correctly. GDB will work
6786 with G77, but does not yet know much about symbols emitted by other
6789 * Better HPUX support
6791 Most debugging facilities now work on dynamic executables for HPPAs
6792 running hpux9 or later. You can attach to running dynamically linked
6793 processes, but by default the dynamic libraries will be read-only, so
6794 for instance you won't be able to put breakpoints in them. To change
6795 that behavior do the following before running the program:
6801 This will cause the libraries to be mapped private and read-write.
6802 To revert to the normal behavior, do this:
6808 You cannot set breakpoints or examine data in the library until after
6809 the library is loaded if the function/data symbols do not have
6812 GDB can now also read debug symbols produced by the HP C compiler on
6813 HPPAs (sorry, no C++, Fortran or 68k support).
6815 * Target byte order now dynamically selectable
6817 You can choose which byte order to use with a target system, via the
6818 commands "set endian big" and "set endian little", and you can see the
6819 current setting by using "show endian". You can also give the command
6820 "set endian auto", in which case GDB will use the byte order
6821 associated with the executable. Currently, only embedded MIPS
6822 configurations support dynamic selection of target byte order.
6824 * New DOS host serial code
6826 This version uses DPMI interrupts to handle buffered I/O, so you
6827 no longer need to run asynctsr when debugging boards connected to
6830 *** Changes in GDB-4.13:
6832 * New "complete" command
6834 This lists all the possible completions for the rest of the line, if it
6835 were to be given as a command itself. This is intended for use by emacs.
6837 * Trailing space optional in prompt
6839 "set prompt" no longer adds a space for you after the prompt you set. This
6840 allows you to set a prompt which ends in a space or one that does not.
6842 * Breakpoint hit counts
6844 "info break" now displays a count of the number of times the breakpoint
6845 has been hit. This is especially useful in conjunction with "ignore"; you
6846 can ignore a large number of breakpoint hits, look at the breakpoint info
6847 to see how many times the breakpoint was hit, then run again, ignoring one
6848 less than that number, and this will get you quickly to the last hit of
6851 * Ability to stop printing at NULL character
6853 "set print null-stop" will cause GDB to stop printing the characters of
6854 an array when the first NULL is encountered. This is useful when large
6855 arrays actually contain only short strings.
6857 * Shared library breakpoints
6859 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6860 breakpoints in shared libraries before the executable is run.
6862 * Hardware watchpoints
6864 There is a new hardware breakpoint for the watch command for sparclite
6865 targets. See gdb/sparclite/hw_breakpoint.note.
6867 Hardware watchpoints are also now supported under GNU/Linux.
6871 Annotations have been added. These are for use with graphical interfaces,
6872 and are still experimental. Currently only gdba.el uses these.
6874 * Improved Irix 5 support
6876 GDB now works properly with Irix 5.2.
6878 * Improved HPPA support
6880 GDB now works properly with the latest GCC and GAS.
6882 * New native configurations
6884 Sequent PTX4 i[34]86-sequent-ptx4
6885 HPPA running OSF/1 hppa*-*-osf*
6886 Atari TT running SVR4 m68*-*-sysv4*
6887 RS/6000 LynxOS rs6000-*-lynxos*
6891 OS/9000 i[34]86-*-os9k
6892 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6895 * Hitachi SH7000 and E7000-PC ICE support
6897 There is now support for communicating with the Hitachi E7000-PC ICE.
6898 This is available automatically when GDB is configured for the SH.
6902 As usual, a variety of small fixes and improvements, both generic
6903 and configuration-specific. See the ChangeLog for more detail.
6905 *** Changes in GDB-4.12:
6907 * Irix 5 is now supported
6911 GDB-4.12 on the HPPA has a number of changes which make it unable
6912 to debug the output from the currently released versions of GCC and
6913 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6914 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6915 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6918 *** Changes in GDB-4.11:
6920 * User visible changes:
6924 The "set remotedebug" option is now consistent between the mips remote
6925 target, remote targets using the gdb-specific protocol, UDI (AMD's
6926 debug protocol for the 29k) and the 88k bug monitor. It is now an
6927 integer specifying a debug level (normally 0 or 1, but 2 means more
6928 debugging info for the mips target).
6930 * DEC Alpha native support
6932 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6933 debug info, but GDB works fairly well with the DEC compiler and should
6934 work with a future GCC release. See the README file for a few
6935 Alpha-specific notes.
6937 * Preliminary thread implementation
6939 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6941 * LynxOS native and target support for 386
6943 This release has been hosted on LynxOS 2.2, and also can be configured
6944 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6947 * Improvements in C++ mangling/demangling.
6949 This release has much better g++ debugging, specifically in name
6950 mangling/demangling, virtual function calls, print virtual table,
6951 call methods, ...etc.
6953 *** Changes in GDB-4.10:
6955 * User visible changes:
6957 Remote debugging using the GDB-specific (`target remote') protocol now
6958 supports the `load' command. This is only useful if you have some
6959 other way of getting the stub to the target system, and you can put it
6960 somewhere in memory where it won't get clobbered by the download.
6962 Filename completion now works.
6964 When run under emacs mode, the "info line" command now causes the
6965 arrow to point to the line specified. Also, "info line" prints
6966 addresses in symbolic form (as well as hex).
6968 All vxworks based targets now support a user settable option, called
6969 vxworks-timeout. This option represents the number of seconds gdb
6970 should wait for responses to rpc's. You might want to use this if
6971 your vxworks target is, perhaps, a slow software simulator or happens
6972 to be on the far side of a thin network line.
6976 This release contains support for using a DEC alpha as a GDB host for
6977 cross debugging. Native alpha debugging is not supported yet.
6980 *** Changes in GDB-4.9:
6984 This is the first GDB release which is accompanied by a matching testsuite.
6985 The testsuite requires installation of dejagnu, which should be available
6986 via ftp from most sites that carry GNU software.
6990 'Cfront' style demangling has had its name changed to 'ARM' style, to
6991 emphasize that it was written from the specifications in the C++ Annotated
6992 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6993 disclaimers, it still generated too much confusion with users attempting to
6994 use gdb with AT&T cfront.
6998 GDB now uses a standard remote interface to a simulator library.
6999 So far, the library contains simulators for the Zilog Z8001/2, the
7000 Hitachi H8/300, H8/500 and Super-H.
7002 * New targets supported
7004 H8/300 simulator h8300-hitachi-hms or h8300hms
7005 H8/500 simulator h8500-hitachi-hms or h8500hms
7006 SH simulator sh-hitachi-hms or sh
7007 Z8000 simulator z8k-zilog-none or z8ksim
7008 IDT MIPS board over serial line mips-idt-ecoff
7010 Cross-debugging to GO32 targets is supported. It requires a custom
7011 version of the i386-stub.c module which is integrated with the
7012 GO32 memory extender.
7014 * New remote protocols
7016 MIPS remote debugging protocol.
7018 * New source languages supported
7020 This version includes preliminary support for Chill, a Pascal like language
7021 used by telecommunications companies. Chill support is also being integrated
7022 into the GNU compiler, but we don't know when it will be publically available.
7025 *** Changes in GDB-4.8:
7027 * HP Precision Architecture supported
7029 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7030 version of this support was available as a set of patches from the
7031 University of Utah. GDB does not support debugging of programs
7032 compiled with the HP compiler, because HP will not document their file
7033 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7034 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7036 Many problems in the preliminary version have been fixed.
7038 * Faster and better demangling
7040 We have improved template demangling and fixed numerous bugs in the GNU style
7041 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7042 character types (wchar_t) are now supported. Demangling of each symbol is now
7043 only done once, and is cached when the symbol table for a file is read in.
7044 This results in a small increase in memory usage for C programs, a moderate
7045 increase in memory usage for C++ programs, and a fantastic speedup in
7048 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7049 from the specifications in the Annotated Reference Manual, which AT&T's
7050 compiler does not actually implement.
7052 * G++ multiple inheritance compiler problem
7054 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7055 inheritance lattices was reworked to properly discover ambiguities. We
7056 recently found an example which causes this new algorithm to fail in a
7057 very subtle way, producing bad debug information for those classes.
7058 The file 'gcc.patch' (in this directory) can be applied to gcc to
7059 circumvent the problem. A future GCC release will contain a complete
7062 The previous G++ debug info problem (mentioned below for the gdb-4.7
7063 release) is fixed in gcc version 2.3.2.
7065 * Improved configure script
7067 The `configure' script will now attempt to guess your system type if
7068 you don't supply a host system type. The old scheme of supplying a
7069 host system triplet is preferable over using this. All the magic is
7070 done in the new `config.guess' script. Examine it for details.
7072 We have also brought our configure script much more in line with the FSF's
7073 version. It now supports the --with-xxx options. In particular,
7074 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7075 The resulting GDB will not be able to read arbitrary object file formats --
7076 only the format ``expected'' to be used on the configured target system.
7077 We hope to make this the default in a future release.
7079 * Documentation improvements
7081 There's new internal documentation on how to modify GDB, and how to
7082 produce clean changes to the code. We implore people to read it
7083 before submitting changes.
7085 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7086 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7087 `info' files are also provided. To build `info' files from scratch,
7088 you will need the latest `makeinfo' release, which will be available in
7089 a future texinfo-X.Y release.
7091 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7092 We're not sure exactly which versions have this problem, but it has
7093 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7094 or better. If that isn't possible, there is a patch in
7095 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7096 around this problem.
7100 GDB now supports array constants that can be used in expressions typed in by
7101 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7102 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7105 The new directory `gdb/sparclite' contains a program that demonstrates
7106 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7108 * New native hosts supported
7110 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7111 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7113 * New targets supported
7115 AMD 29k family via UDI a29k-amd-udi or udi29k
7117 * New file formats supported
7119 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7120 HPUX core files, and SCO 3.2v2 core files.
7124 Attaching to processes now works again; thanks for the many bug reports.
7126 We have also stomped on a bunch of core dumps caused by
7127 printf_filtered("%s") problems.
7129 We eliminated a copyright problem on the rpc and ptrace header files
7130 for VxWorks, which was discovered at the last minute during the 4.7
7131 release. You should now be able to build a VxWorks GDB.
7133 You can now interrupt gdb while an attached process is running. This
7134 will cause the attached process to stop, and give control back to GDB.
7136 We fixed problems caused by using too many file descriptors
7137 for reading symbols from object files and libraries. This was
7138 especially a problem for programs that used many (~100) shared
7141 The `step' command now only enters a subroutine if there is line number
7142 information for the subroutine. Otherwise it acts like the `next'
7143 command. Previously, `step' would enter subroutines if there was
7144 any debugging information about the routine. This avoids problems
7145 when using `cc -g1' on MIPS machines.
7147 * Internal improvements
7149 GDB's internal interfaces have been improved to make it easier to support
7150 debugging of multiple languages in the future.
7152 GDB now uses a common structure for symbol information internally.
7153 Minimal symbols (derived from linkage symbols in object files), partial
7154 symbols (from a quick scan of debug information), and full symbols
7155 contain a common subset of information, making it easier to write
7156 shared code that handles any of them.
7158 * New command line options
7160 We now accept --silent as an alias for --quiet.
7164 The memory-mapped-malloc library is now licensed under the GNU Library
7165 General Public License.
7167 *** Changes in GDB-4.7:
7169 * Host/native/target split
7171 GDB has had some major internal surgery to untangle the support for
7172 hosts and remote targets. Now, when you configure GDB for a remote
7173 target, it will no longer load in all of the support for debugging
7174 local programs on the host. When fully completed and tested, this will
7175 ensure that arbitrary host/target combinations are possible.
7177 The primary conceptual shift is to separate the non-portable code in
7178 GDB into three categories. Host specific code is required any time GDB
7179 is compiled on that host, regardless of the target. Target specific
7180 code relates to the peculiarities of the target, but can be compiled on
7181 any host. Native specific code is everything else: it can only be
7182 built when the host and target are the same system. Child process
7183 handling and core file support are two common `native' examples.
7185 GDB's use of /proc for controlling Unix child processes is now cleaner.
7186 It has been split out into a single module under the `target_ops' vector,
7187 plus two native-dependent functions for each system that uses /proc.
7189 * New hosts supported
7191 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7192 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7193 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7195 * New targets supported
7197 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7198 68030 and CPU32 m68030-*-*, m68332-*-*
7200 * New native hosts supported
7202 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7203 (386bsd is not well tested yet)
7204 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7206 * New file formats supported
7208 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7209 supports reading of `a.out.adobe' object files, which are an a.out
7210 format extended with minimal information about multiple sections.
7214 `show copying' is the same as the old `info copying'.
7215 `show warranty' is the same as `info warrantee'.
7216 These were renamed for consistency. The old commands continue to work.
7218 `info handle' is a new alias for `info signals'.
7220 You can now define pre-command hooks, which attach arbitrary command
7221 scripts to any command. The commands in the hook will be executed
7222 prior to the user's command. You can also create a hook which will be
7223 executed whenever the program stops. See gdb.texinfo.
7227 We now deal with Cfront style name mangling, and can even extract type
7228 info from mangled symbols. GDB can automatically figure out which
7229 symbol mangling style your C++ compiler uses.
7231 Calling of methods and virtual functions has been improved as well.
7235 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7236 fixed. This was due to mishandling of the extra N_SO stabs output
7239 We also finally got Ultrix 4.2 running in house, and fixed core file
7240 support, with help from a dozen people on the net.
7242 John M. Farrell discovered that the reason that single-stepping was so
7243 slow on all of the Mips based platforms (primarily SGI and DEC) was
7244 that we were trying to demangle and lookup a symbol used for internal
7245 purposes on every instruction that was being stepped through. Changing
7246 the name of that symbol so that it couldn't be mistaken for a C++
7247 mangled symbol sped things up a great deal.
7249 Rich Pixley sped up symbol lookups in general by getting much smarter
7250 about when C++ symbol mangling is necessary. This should make symbol
7251 completion (TAB on the command line) much faster. It's not as fast as
7252 we'd like, but it's significantly faster than gdb-4.6.
7256 A new user controllable variable 'call_scratch_address' can
7257 specify the location of a scratch area to be used when GDB
7258 calls a function in the target. This is necessary because the
7259 usual method of putting the scratch area on the stack does not work
7260 in systems that have separate instruction and data spaces.
7262 We integrated changes to support the 29k UDI (Universal Debugger
7263 Interface), but discovered at the last minute that we didn't have all
7264 of the appropriate copyright paperwork. We are working with AMD to
7265 resolve this, and hope to have it available soon.
7269 We have sped up the remote serial line protocol, especially for targets
7270 with lots of registers. It now supports a new `expedited status' ('T')
7271 message which can be used in place of the existing 'S' status message.
7272 This allows the remote stub to send only the registers that GDB
7273 needs to make a quick decision about single-stepping or conditional
7274 breakpoints, eliminating the need to fetch the entire register set for
7275 each instruction being stepped through.
7277 The GDB remote serial protocol now implements a write-through cache for
7278 registers, only re-reading the registers if the target has run.
7280 There is also a new remote serial stub for SPARC processors. You can
7281 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7282 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7283 processor with a serial port.
7287 Configure.in files have become much easier to read and modify. A new
7288 `table driven' format makes it more obvious what configurations are
7289 supported, and what files each one uses.
7293 There is a new opcodes library which will eventually contain all of the
7294 disassembly routines and opcode tables. At present, it only contains
7295 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7296 disassembler (binutils/objdump) to share these routines.
7298 The libiberty library is now copylefted under the GNU Library General
7299 Public License. This allows more liberal use, and was done so libg++
7300 can use it. This makes no difference to GDB, since the Library License
7301 grants all the rights from the General Public License.
7305 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7306 reference to the stabs symbol info used by the debugger. It is (as far
7307 as we know) the only published document on this fascinating topic. We
7308 encourage you to read it, compare it to the stabs information on your
7309 system, and send improvements on the document in general (to
7310 bug-gdb@prep.ai.mit.edu).
7312 And, of course, many bugs have been fixed.
7315 *** Changes in GDB-4.6:
7317 * Better support for C++ function names
7319 GDB now accepts as input the "demangled form" of C++ overloaded function
7320 names and member function names, and can do command completion on such names
7321 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7322 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7323 Make use of command completion, it is your friend.
7325 GDB also now accepts a variety of C++ mangled symbol formats. They are
7326 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7327 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7328 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7329 for the list of formats.
7331 * G++ symbol mangling problem
7333 Recent versions of gcc have a bug in how they emit debugging information for
7334 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7335 directory) can be applied to gcc to fix the problem. Alternatively, if you
7336 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7337 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7338 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7341 * New 'maintenance' command
7343 All of the commands related to hacking GDB internals have been moved out of
7344 the main command set, and now live behind the 'maintenance' command. This
7345 can also be abbreviated as 'mt'. The following changes were made:
7347 dump-me -> maintenance dump-me
7348 info all-breakpoints -> maintenance info breakpoints
7349 printmsyms -> maintenance print msyms
7350 printobjfiles -> maintenance print objfiles
7351 printpsyms -> maintenance print psymbols
7352 printsyms -> maintenance print symbols
7354 The following commands are new:
7356 maintenance demangle Call internal GDB demangler routine to
7357 demangle a C++ link name and prints the result.
7358 maintenance print type Print a type chain for a given symbol
7360 * Change to .gdbinit file processing
7362 We now read the $HOME/.gdbinit file before processing the argv arguments
7363 (e.g. reading symbol files or core files). This allows global parameters to
7364 be set, which will apply during the symbol reading. The ./.gdbinit is still
7365 read after argv processing.
7367 * New hosts supported
7369 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7371 GNU/Linux support i386-unknown-linux or linux
7373 We are also including code to support the HP/PA running BSD and HPUX. This
7374 is almost guaranteed not to work, as we didn't have time to test or build it
7375 for this release. We are including it so that the more adventurous (or
7376 masochistic) of you can play with it. We also had major problems with the
7377 fact that the compiler that we got from HP doesn't support the -g option.
7380 * New targets supported
7382 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7384 * More smarts about finding #include files
7386 GDB now remembers the compilation directory for all include files, and for
7387 all files from which C is generated (like yacc and lex sources). This
7388 greatly improves GDB's ability to find yacc/lex sources, and include files,
7389 especially if you are debugging your program from a directory different from
7390 the one that contains your sources.
7392 We also fixed a bug which caused difficulty with listing and setting
7393 breakpoints in include files which contain C code. (In the past, you had to
7394 try twice in order to list an include file that you hadn't looked at before.)
7396 * Interesting infernals change
7398 GDB now deals with arbitrary numbers of sections, where the symbols for each
7399 section must be relocated relative to that section's landing place in the
7400 target's address space. This work was needed to support ELF with embedded
7401 stabs used by Solaris-2.0.
7403 * Bug fixes (of course!)
7405 There have been loads of fixes for the following things:
7406 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7407 i960, stabs, DOS(GO32), procfs, etc...
7409 See the ChangeLog for details.
7411 *** Changes in GDB-4.5:
7413 * New machines supported (host and target)
7415 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7417 SGI Irix-4.x mips-sgi-irix4 or iris4
7419 * New malloc package
7421 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7422 Mmalloc is capable of handling multiple heaps of memory. It is also
7423 capable of saving a heap to a file, and then mapping it back in later.
7424 This can be used to greatly speedup the startup of GDB by using a
7425 pre-parsed symbol table which lives in a mmalloc managed heap. For
7426 more details, please read mmalloc/mmalloc.texi.
7430 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7431 'help info proc' for details.
7433 * MIPS ecoff symbol table format
7435 The code that reads MIPS symbol table format is now supported on all hosts.
7436 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7439 * File name changes for MS-DOS
7441 Many files in the config directories have been renamed to make it easier to
7442 support GDB on MS-DOSe systems (which have very restrictive file name
7443 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7444 environment) is close to working but has some remaining problems. Note
7445 that debugging of DOS programs is not supported, due to limitations
7446 in the ``operating system'', but it can be used to host cross-debugging.
7448 * Cross byte order fixes
7450 Many fixes have been made to support cross debugging of Sparc and MIPS
7451 targets from hosts whose byte order differs.
7453 * New -mapped and -readnow options
7455 If memory-mapped files are available on your system through the 'mmap'
7456 system call, you can use the -mapped option on the `file' or
7457 `symbol-file' commands to cause GDB to write the symbols from your
7458 program into a reusable file. If the program you are debugging is
7459 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7460 Future GDB debugging sessions will notice the presence of this file,
7461 and will quickly map in symbol information from it, rather than reading
7462 the symbol table from the executable program. Using the '-mapped'
7463 option in a GDB `file' or `symbol-file' command has the same effect as
7464 starting GDB with the '-mapped' command-line option.
7466 You can cause GDB to read the entire symbol table immediately by using
7467 the '-readnow' option with any of the commands that load symbol table
7468 information (or on the GDB command line). This makes the command
7469 slower, but makes future operations faster.
7471 The -mapped and -readnow options are typically combined in order to
7472 build a `fred.syms' file that contains complete symbol information.
7473 A simple GDB invocation to do nothing but build a `.syms' file for future
7476 gdb -batch -nx -mapped -readnow programname
7478 The `.syms' file is specific to the host machine on which GDB is run.
7479 It holds an exact image of GDB's internal symbol table. It cannot be
7480 shared across multiple host platforms.
7482 * longjmp() handling
7484 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7485 siglongjmp() without losing control. This feature has not yet been ported to
7486 all systems. It currently works on many 386 platforms, all MIPS-based
7487 platforms (SGI, DECstation, etc), and Sun3/4.
7491 Preliminary work has been put in to support the new Solaris OS from Sun. At
7492 this time, it can control and debug processes, but it is not capable of
7497 As always, many many bug fixes. The major areas were with g++, and mipsread.
7498 People using the MIPS-based platforms should experience fewer mysterious
7499 crashes and trashed symbol tables.
7501 *** Changes in GDB-4.4:
7503 * New machines supported (host and target)
7505 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7507 BSD Reno on Vax vax-dec-bsd
7508 Ultrix on Vax vax-dec-ultrix
7510 * New machines supported (target)
7512 AMD 29000 embedded, using EBMON a29k-none-none
7516 GDB continues to improve its handling of C++. `References' work better.
7517 The demangler has also been improved, and now deals with symbols mangled as
7518 per the Annotated C++ Reference Guide.
7520 GDB also now handles `stabs' symbol information embedded in MIPS
7521 `ecoff' symbol tables. Since the ecoff format was not easily
7522 extensible to handle new languages such as C++, this appeared to be a
7523 good way to put C++ debugging info into MIPS binaries. This option
7524 will be supported in the GNU C compiler, version 2, when it is
7527 * New features for SVR4
7529 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7530 shared libraries. Debugging dynamically linked programs should present
7531 only minor differences from debugging statically linked programs.
7533 The `info proc' command will print out information about any process
7534 on an SVR4 system (including the one you are debugging). At the moment,
7535 it prints the address mappings of the process.
7537 If you bring up GDB on another SVR4 system, please send mail to
7538 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7540 * Better dynamic linking support in SunOS
7542 Reading symbols from shared libraries which contain debugging symbols
7543 now works properly. However, there remain issues such as automatic
7544 skipping of `transfer vector' code during function calls, which
7545 make it harder to debug code in a shared library, than to debug the
7546 same code linked statically.
7550 GDB is now using the latest `getopt' routines from the FSF. This
7551 version accepts the -- prefix for options with long names. GDB will
7552 continue to accept the old forms (-option and +option) as well.
7553 Various single letter abbreviations for options have been explicity
7554 added to the option table so that they won't get overshadowed in the
7555 future by other options that begin with the same letter.
7559 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7560 Many assorted bugs have been handled. Many more remain to be handled.
7561 See the various ChangeLog files (primarily in gdb and bfd) for details.
7564 *** Changes in GDB-4.3:
7566 * New machines supported (host and target)
7568 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7569 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7570 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7572 * Almost SCO Unix support
7574 We had hoped to support:
7575 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7576 (except for core file support), but we discovered very late in the release
7577 that it has problems with process groups that render gdb unusable. Sorry
7578 about that. I encourage people to fix it and post the fixes.
7580 * Preliminary ELF and DWARF support
7582 GDB can read ELF object files on System V Release 4, and can handle
7583 debugging records for C, in DWARF format, in ELF files. This support
7584 is preliminary. If you bring up GDB on another SVR4 system, please
7585 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7590 GDB now uses the latest `readline' library. One user-visible change
7591 is that two tabs will list possible command completions, which previously
7592 required typing M-? (meta-question mark, or ESC ?).
7596 The `stepi' bug that many of you noticed has been squashed.
7597 Many bugs in C++ have been handled. Many more remain to be handled.
7598 See the various ChangeLog files (primarily in gdb and bfd) for details.
7600 * State of the MIPS world (in case you wondered):
7602 GDB can understand the symbol tables emitted by the compilers
7603 supplied by most vendors of MIPS-based machines, including DEC. These
7604 symbol tables are in a format that essentially nobody else uses.
7606 Some versions of gcc come with an assembler post-processor called
7607 mips-tfile. This program is required if you want to do source-level
7608 debugging of gcc-compiled programs. I believe FSF does not ship
7609 mips-tfile with gcc version 1, but it will eventually come with gcc
7612 Debugging of g++ output remains a problem. g++ version 1.xx does not
7613 really support it at all. (If you're lucky, you should be able to get
7614 line numbers and stack traces to work, but no parameters or local
7615 variables.) With some work it should be possible to improve the
7618 When gcc version 2 is released, you will have somewhat better luck.
7619 However, even then you will get confusing results for inheritance and
7622 We will eventually provide full debugging of g++ output on
7623 DECstations. This will probably involve some kind of stabs-in-ecoff
7624 encapulation, but the details have not been worked out yet.
7627 *** Changes in GDB-4.2:
7629 * Improved configuration
7631 Only one copy of `configure' exists now, and it is not self-modifying.
7632 Porting BFD is simpler.
7636 The `step' and `next' commands now only stop at the first instruction
7637 of a source line. This prevents the multiple stops that used to occur
7638 in switch statements, for-loops, etc. `Step' continues to stop if a
7639 function that has debugging information is called within the line.
7643 Lots of small bugs fixed. More remain.
7645 * New host supported (not target)
7647 Intel 386 PC clone running Mach i386-none-mach
7650 *** Changes in GDB-4.1:
7652 * Multiple source language support
7654 GDB now has internal scaffolding to handle several source languages.
7655 It determines the type of each source file from its filename extension,
7656 and will switch expression parsing and number formatting to match the
7657 language of the function in the currently selected stack frame.
7658 You can also specifically set the language to be used, with
7659 `set language c' or `set language modula-2'.
7663 GDB now has preliminary support for the GNU Modula-2 compiler,
7664 currently under development at the State University of New York at
7665 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7666 continue through the fall of 1991 and into 1992.
7668 Other Modula-2 compilers are currently not supported, and attempting to
7669 debug programs compiled with them will likely result in an error as the
7670 symbol table is read. Feel free to work on it, though!
7672 There are hooks in GDB for strict type checking and range checking,
7673 in the `Modula-2 philosophy', but they do not currently work.
7677 GDB can now write to executable and core files (e.g. patch
7678 a variable's value). You must turn this switch on, specify
7679 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7680 by assigning a new value to a variable. Modifications take
7683 * Automatic SunOS shared library reading
7685 When you run your program, GDB automatically determines where its
7686 shared libraries (if any) have been loaded, and reads their symbols.
7687 The `share' command is no longer needed. This also works when
7688 examining core files.
7692 You can specify the number of lines that the `list' command shows.
7695 * New machines supported (host and target)
7697 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7698 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7699 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7701 * New hosts supported (not targets)
7703 IBM RT/PC: romp-ibm-aix or rtpc
7705 * New targets supported (not hosts)
7707 AMD 29000 embedded with COFF a29k-none-coff
7708 AMD 29000 embedded with a.out a29k-none-aout
7709 Ultracomputer remote kernel debug a29k-nyu-kern
7711 * New remote interfaces
7717 *** Changes in GDB-4.0:
7721 Wide output is wrapped at good places to make the output more readable.
7723 Gdb now supports cross-debugging from a host machine of one type to a
7724 target machine of another type. Communication with the target system
7725 is over serial lines. The ``target'' command handles connecting to the
7726 remote system; the ``load'' command will download a program into the
7727 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7728 also supports debugging of realtime processes running under VxWorks,
7729 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7730 stub on the target system.
7732 New CPUs supported include the AMD 29000 and Intel 960.
7734 GDB now reads object files and symbol tables via a ``binary file''
7735 library, which allows a single copy of GDB to debug programs of multiple
7736 object file types such as a.out and coff.
7738 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7739 refcard.dvi and refcard.ps are available to format it).
7742 * Control-Variable user interface simplified
7744 All variables that control the operation of the debugger can be set
7745 by the ``set'' command, and displayed by the ``show'' command.
7747 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7748 ``Show prompt'' produces the response:
7749 Gdb's prompt is new-gdb=>.
7751 What follows are the NEW set commands. The command ``help set'' will
7752 print a complete list of old and new set commands. ``help set FOO''
7753 will give a longer description of the variable FOO. ``show'' will show
7754 all of the variable descriptions and their current settings.
7756 confirm on/off: Enables warning questions for operations that are
7757 hard to recover from, e.g. rerunning the program while
7758 it is already running. Default is ON.
7760 editing on/off: Enables EMACS style command line editing
7761 of input. Previous lines can be recalled with
7762 control-P, the current line can be edited with control-B,
7763 you can search for commands with control-R, etc.
7766 history filename NAME: NAME is where the gdb command history
7767 will be stored. The default is .gdb_history,
7768 or the value of the environment variable
7771 history size N: The size, in commands, of the command history. The
7772 default is 256, or the value of the environment variable
7775 history save on/off: If this value is set to ON, the history file will
7776 be saved after exiting gdb. If set to OFF, the
7777 file will not be saved. The default is OFF.
7779 history expansion on/off: If this value is set to ON, then csh-like
7780 history expansion will be performed on
7781 command line input. The default is OFF.
7783 radix N: Sets the default radix for input and output. It can be set
7784 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7785 in the current radix, so "set radix 10" is always a no-op.
7787 height N: This integer value is the number of lines on a page. Default
7788 is 24, the current `stty rows'' setting, or the ``li#''
7789 setting from the termcap entry matching the environment
7792 width N: This integer value is the number of characters on a line.
7793 Default is 80, the current `stty cols'' setting, or the ``co#''
7794 setting from the termcap entry matching the environment
7797 Note: ``set screensize'' is obsolete. Use ``set height'' and
7798 ``set width'' instead.
7800 print address on/off: Print memory addresses in various command displays,
7801 such as stack traces and structure values. Gdb looks
7802 more ``symbolic'' if you turn this off; it looks more
7803 ``machine level'' with it on. Default is ON.
7805 print array on/off: Prettyprint arrays. New convenient format! Default
7808 print demangle on/off: Print C++ symbols in "source" form if on,
7811 print asm-demangle on/off: Same, for assembler level printouts
7814 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7817 * Support for Epoch Environment.
7819 The epoch environment is a version of Emacs v18 with windowing. One
7820 new command, ``inspect'', is identical to ``print'', except that if you
7821 are running in the epoch environment, the value is printed in its own
7825 * Support for Shared Libraries
7827 GDB can now debug programs and core files that use SunOS shared libraries.
7828 Symbols from a shared library cannot be referenced
7829 before the shared library has been linked with the program (this
7830 happens after you type ``run'' and before the function main() is entered).
7831 At any time after this linking (including when examining core files
7832 from dynamically linked programs), gdb reads the symbols from each
7833 shared library when you type the ``sharedlibrary'' command.
7834 It can be abbreviated ``share''.
7836 sharedlibrary REGEXP: Load shared object library symbols for files
7837 matching a unix regular expression. No argument
7838 indicates to load symbols for all shared libraries.
7840 info sharedlibrary: Status of loaded shared libraries.
7845 A watchpoint stops execution of a program whenever the value of an
7846 expression changes. Checking for this slows down execution
7847 tremendously whenever you are in the scope of the expression, but is
7848 quite useful for catching tough ``bit-spreader'' or pointer misuse
7849 problems. Some machines such as the 386 have hardware for doing this
7850 more quickly, and future versions of gdb will use this hardware.
7852 watch EXP: Set a watchpoint (breakpoint) for an expression.
7854 info watchpoints: Information about your watchpoints.
7856 delete N: Deletes watchpoint number N (same as breakpoints).
7857 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7858 enable N: Re-enables watchpoint number N (same as breakpoints).
7861 * C++ multiple inheritance
7863 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7866 * C++ exception handling
7868 Gdb now supports limited C++ exception handling. Besides the existing
7869 ability to breakpoint on an exception handler, gdb can breakpoint on
7870 the raising of an exception (before the stack is peeled back to the
7873 catch FOO: If there is a FOO exception handler in the dynamic scope,
7874 set a breakpoint to catch exceptions which may be raised there.
7875 Multiple exceptions (``catch foo bar baz'') may be caught.
7877 info catch: Lists all exceptions which may be caught in the
7878 current stack frame.
7881 * Minor command changes
7883 The command ``call func (arg, arg, ...)'' now acts like the print
7884 command, except it does not print or save a value if the function's result
7885 is void. This is similar to dbx usage.
7887 The ``up'' and ``down'' commands now always print the frame they end up
7888 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7889 frames without printing.
7891 * New directory command
7893 'dir' now adds directories to the FRONT of the source search path.
7894 The path starts off empty. Source files that contain debug information
7895 about the directory in which they were compiled can be found even
7896 with an empty path; Sun CC and GCC include this information. If GDB can't
7897 find your source file in the current directory, type "dir .".
7899 * Configuring GDB for compilation
7901 For normal use, type ``./configure host''. See README or gdb.texinfo
7904 GDB now handles cross debugging. If you are remotely debugging between
7905 two different machines, type ``./configure host -target=targ''.
7906 Host is the machine where GDB will run; targ is the machine
7907 where the program that you are debugging will run.