1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 10
8 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
10 The MI -break-insert and -dprintf-insert commands now support a
11 new "--qualified" option that makes GDB interpret a specified
12 function name as a complete fully-qualified name. This is the
13 equivalent of the CLI's "break -qualified" and "dprintf
16 * GDB now supports core file debugging for x86_64 Cygwin programs.
22 Control the display of debug output about GDB's event loop.
26 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
27 and "org.gnu.gdb.arc.aux". The old names are still supported but
28 must be considered obsolete. They will be deprecated after some
31 * Help and apropos commands will now show the documentation of a
32 command only once, even if that command has one or more aliases.
33 These commands now show the command name, then all of its aliases,
34 and finally the description of the command.
36 * 'help aliases' now shows only the user defined aliases. GDB predefined
37 aliases are shown together with their aliased command.
39 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
40 debugging information as well as source code.
42 When built with debuginfod, GDB can automatically query debuginfod
43 servers for the separate debug files and source code of the executable
46 To build GDB with debuginfod, pass --with-debuginfod to configure (this
47 requires libdebuginfod, the debuginfod client library).
49 debuginfod is distributed with elfutils, starting with version 0.178.
51 You can get the latest version from https://sourceware.org/elfutils.
53 * Multi-target debugging support
55 GDB now supports debugging multiple target connections
56 simultaneously. For example, you can now have each inferior
57 connected to different remote servers running in different machines,
58 or have one inferior debugging a local native process, an inferior
59 debugging a core dump, etc.
61 This support is experimental and comes with some limitations -- you
62 can only resume multiple targets simultaneously if all targets
63 support non-stop mode, and all remote stubs or servers must support
64 the same set of remote protocol features exactly. See also "info
65 connections" and "add-inferior -no-connection" below, and "maint set
66 target-non-stop" in the user manual.
68 * New features in the GDB remote stub, GDBserver
70 ** GDBserver is now supported on RISC-V GNU/Linux.
72 ** GDBserver no longer supports these host triplets:
83 i[34567]86-*-mingw32ce*
85 * Debugging MS-Windows processes now sets $_exitsignal when the
86 inferior is terminated by a signal, instead of setting $_exitcode.
88 * Multithreaded symbol loading has now been enabled by default on systems
89 that support it (see entry for GDB 9, below), providing faster
90 performance for programs with many symbols.
92 * The $_siginfo convenience variable now also works on Windows targets,
93 and will display the EXCEPTION_RECORD of the last handled exception.
95 * TUI windows can now be arranged horizontally.
97 * The command history filename can now be set to the empty string
98 either using 'set history filename' or by setting 'GDBHISTFILE=' in
99 the environment. The effect of setting this filename to the empty
100 string is that GDB will not try to load any previous command
103 * On Windows targets, it is now possible to debug 32-bit programs with a
108 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
109 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
110 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
111 running process, this new option indicates whether to detect
112 a mismatch between the current executable file loaded by GDB and the
113 executable file used to start the process. If 'ask', the default,
114 display a warning and ask the user whether to load the process
115 executable file; if 'warn', just display a warning; if 'off', don't
116 attempt to detect a mismatch.
118 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
119 Define a new TUI layout, specifying its name and the windows that
122 maintenance print xml-tdesc [FILE]
123 Prints the current target description as an XML document. If the
124 optional FILE is provided (which is an XML target description) then
125 the target description is read from FILE into GDB, and then
128 maintenance print core-file-backed-mappings
129 Prints file-backed mappings loaded from a core file's note section.
130 Output is expected to be similar to that of "info proc mappings".
134 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
135 The alias command can now specify default args for an alias.
136 GDB automatically prepends the alias default args to the argument list
137 provided explicitly by the user.
138 For example, to have a backtrace with full details, you can define
140 'alias bt_ALL = backtrace -entry-values both -frame-arg all
141 -past-main -past-entry -full'.
142 Alias default arguments can also use a set of nested 'with' commands,
143 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
144 defines the alias pp10 that will pretty print a maximum of 10 elements
145 of the given expression (if the expression is an array).
149 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
154 ** gdb.register_window_type can be used to implement new TUI windows
157 ** Dynamic types can now be queried. gdb.Type has a new attribute,
158 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
159 field of a dynamic type may have None for its "bitpos" attribute
162 ** Commands written in Python can be in the "TUI" help class by
163 registering with the new constant gdb.COMMAND_TUI.
165 ** New method gdb.PendingFrame.architecture () to retrieve the
166 architecture of the pending frame.
168 ** New gdb.Architecture.registers method that returns a
169 gdb.RegisterDescriptorIterator object, an iterator that returns
170 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
171 way to query the registers available for an architecture.
173 ** New gdb.Architecture.register_groups method that returns a
174 gdb.RegisterGroupIterator object, an iterator that returns
175 gdb.RegisterGroup objects. The new RegisterGroup is a way to
176 discover the available register groups.
180 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
182 ** Procedures 'memory-port-read-buffer-size',
183 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
184 and 'set-memory-port-write-buffer-size!' are deprecated. When
185 using Guile 2.2 and later, users who need to control the size of
186 a memory port's internal buffer can use the 'setvbuf' procedure.
190 * 'thread-exited' event is now available in the annotations interface.
192 * New built-in convenience variables $_gdb_major and $_gdb_minor
193 provide the GDB version. They are handy for conditionally using
194 features available only in or since specific GDB versions, in
195 scripts that should work error-free with many different versions,
196 such as in system-wide init files.
198 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
199 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
200 of the GDB settings and the GDB maintenance settings. They are handy
201 for changing the logic of user defined commands depending on the
202 current GDB settings.
204 * GDB now supports Thread Local Storage (TLS) variables on several
205 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
206 architectures require kernel changes. TLS is not yet supported for
207 amd64 and i386 process core dumps.
209 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
210 addresses that required unmasking are shown in the backtrace with the
213 * Two new convenience functions $_cimag and $_creal that extract the
214 imaginary and real parts respectively from complex numbers.
216 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
217 provide the exitcode or exit status of the shell commands launched by
218 GDB commands such as "shell", "pipe" and "make".
220 * The command define-prefix can now define user defined prefix commands.
221 User defined commands can now be defined using these user defined prefix
224 * Command names can now use the . character.
226 * The RX port now supports XML target descriptions.
228 * GDB now shows the Ada task names at more places, e.g. in task switching
231 * GDB can now be compiled with Python 3 on Windows.
233 * New convenience variable $_ada_exception holds the address of the
234 Ada exception being thrown. This is set by Ada-related catchpoints.
236 * GDB can now place breakpoints on nested functions and subroutines in
237 Fortran code. The '::' operator can be used between parent and
238 child scopes when placing breakpoints, for example:
240 (gdb) break outer_function::inner_function
242 The 'outer_function::' prefix is only needed if 'inner_function' is
243 not visible in the current scope.
245 * In addition to the system-wide gdbinit file, if configured with
246 --with-system-gdbinit-dir, GDB will now also load files in that directory
247 as system gdbinit files, unless the -nx or -n flag is provided. Files
248 with extensions .gdb, .py and .scm are supported as long as GDB was
249 compiled with support for that language.
251 * GDB now supports multithreaded symbol loading for higher performance.
252 This feature is still in testing, so it is disabled by default. You
253 can turn it on using 'maint set worker-threads unlimited'.
257 ** The gdb.Value type has a new method 'format_string' which returns a
258 string representing the value. The formatting is controlled by the
259 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
260 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
261 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
263 ** gdb.Type has a new property 'objfile' which returns the objfile the
266 ** The frame information printed by the python frame filtering code
267 is now consistent with what the 'backtrace' command prints when
268 there are no filters, or when the 'backtrace' '-no-filters' option
271 ** The new function gdb.lookup_static_symbol can be used to look up
272 symbols with static linkage.
274 ** The new function gdb.lookup_static_symbols can be used to look up
275 all static symbols with static linkage.
277 ** gdb.Objfile has new methods 'lookup_global_symbol' and
278 'lookup_static_symbol' to lookup a symbol from this objfile only.
280 ** gdb.Block now supports the dictionary syntax for accessing symbols in
281 this block (e.g. block['local_variable']).
285 | [COMMAND] | SHELL_COMMAND
286 | -d DELIM COMMAND DELIM SHELL_COMMAND
287 pipe [COMMAND] | SHELL_COMMAND
288 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
289 Executes COMMAND and sends its output to SHELL_COMMAND.
290 With no COMMAND, repeat the last executed command
291 and send its output to SHELL_COMMAND.
293 define-prefix COMMAND
294 Define or mark a command as a user-defined prefix command.
296 with SETTING [VALUE] [-- COMMAND]
297 w SETTING [VALUE] [-- COMMAND]
298 Temporarily set SETTING, run COMMAND, and restore SETTING.
299 Usage: with SETTING -- COMMAND
300 With no COMMAND, repeats the last executed command.
301 SETTING is any GDB setting you can change with the "set"
302 subcommands. For example, 'with language c -- print someobj'
303 temporarily switches to the C language in order to print someobj.
304 Settings can be combined: 'w lang c -- w print elements unlimited --
305 usercmd' switches to the C language and runs usercmd with no limit
306 of array elements to print.
308 maint with SETTING [VALUE] [-- COMMAND]
309 Like "with", but works with "maintenance set" settings.
311 set may-call-functions [on|off]
312 show may-call-functions
313 This controls whether GDB will attempt to call functions in
314 the program, such as with expressions in the print command. It
315 defaults to on. Calling functions in the program being debugged
316 can have undesired side effects. It is now possible to forbid
317 such function calls. If function calls are forbidden, GDB will throw
318 an error when a command (such as print expression) calls a function
321 set print finish [on|off]
323 This controls whether the `finish' command will display the value
324 that is returned by the current function. When `off', the value is
325 still entered into the value history, but it is not printed. The
330 Allows deeply nested structures to be simplified when printing by
331 replacing deeply nested parts (beyond the max-depth) with ellipses.
332 The default max-depth is 20, but this can be set to unlimited to get
333 the old behavior back.
335 set print raw-values [on|off]
336 show print raw-values
337 By default, GDB applies the enabled pretty printers when printing a
338 value. This allows to ignore the enabled pretty printers for a series
339 of commands. The default is 'off'.
341 set logging debugredirect [on|off]
342 By default, GDB debug output will go to both the terminal and the logfile.
343 Set if you want debug output to go only to the log file.
345 set style title foreground COLOR
346 set style title background COLOR
347 set style title intensity VALUE
348 Control the styling of titles.
350 set style highlight foreground COLOR
351 set style highlight background COLOR
352 set style highlight intensity VALUE
353 Control the styling of highlightings.
355 maint set worker-threads
356 maint show worker-threads
357 Control the number of worker threads that can be used by GDB. The
358 default is 0. "unlimited" lets GDB choose a number that is
359 reasonable. Currently worker threads are only used when demangling
360 the names of linker symbols.
362 set style tui-border foreground COLOR
363 set style tui-border background COLOR
364 Control the styling of TUI borders.
366 set style tui-active-border foreground COLOR
367 set style tui-active-border background COLOR
368 Control the styling of the active TUI border.
370 maint set test-settings KIND
371 maint show test-settings KIND
372 A set of commands used by the testsuite for exercising the settings
375 maint set tui-resize-message [on|off]
376 maint show tui-resize-message
377 Control whether GDB prints a message each time the terminal is
378 resized when in TUI mode. This is primarily useful for testing the
381 set print frame-info [short-location|location|location-and-address
382 |source-and-location|source-line|auto]
383 show print frame-info
384 This controls what frame information is printed by the commands printing
385 a frame. This setting will e.g. influence the behaviour of 'backtrace',
386 'frame', 'stepi'. The python frame filtering also respect this setting.
387 The 'backtrace' '-frame-info' option can override this global setting.
389 set tui compact-source
390 show tui compact-source
392 Enable the "compact" display mode for the TUI source window. The
393 compact display uses only as much space as is needed for the line
394 numbers in the current file, and only a single space to separate the
395 line numbers from the source.
397 info modules [-q] [REGEXP]
398 Return a list of Fortran modules matching REGEXP, or all modules if
401 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
402 Return a list of functions within all modules, grouped by module.
403 The list of functions can be restricted with the optional regular
404 expressions. MODULE_REGEXP matches against the module name,
405 TYPE_REGEXP matches against the function type signature, and REGEXP
406 matches against the function name.
408 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
409 Return a list of variables within all modules, grouped by module.
410 The list of variables can be restricted with the optional regular
411 expressions. MODULE_REGEXP matches against the module name,
412 TYPE_REGEXP matches against the variable type, and REGEXP matches
413 against the variable name.
415 set debug remote-packet-max-chars
416 show debug remote-packet-max-chars
417 Controls the number of characters to output in a remote packet when using
419 The default is 512 bytes.
422 Lists the target connections currently in use.
427 The "help" command uses the title style to enhance the
428 readibility of its output by styling the classes and
432 Similarly to "help", the "apropos" command also uses the
433 title style for the command names. "apropos" accepts now
434 a flag "-v" (verbose) to show the full documentation
435 of matching commands and to use the highlight style to mark
436 the documentation parts matching REGEXP.
440 The GDB printf and eval commands can now print C-style and Ada-style
441 string convenience variables without calling functions in the program.
442 This allows to do formatted printing of strings without having
443 a running inferior, or when debugging a core dump.
445 info sources [-dirname | -basename] [--] [REGEXP]
446 This command has now optional arguments to only print the files
447 whose names match REGEXP. The arguments -dirname and -basename
448 allow to restrict matching respectively to the dirname and basename
452 The "show style" and its subcommands are now styling
453 a style name in their output using its own style, to help
454 the user visualize the different styles.
456 set print frame-arguments
457 The new value 'presence' indicates to only indicate the presence of
458 arguments using ..., instead of printing argument names and values.
460 set print raw-frame-arguments
461 show print raw-frame-arguments
463 These commands replace the similarly-named "set/show print raw
464 frame-arguments" commands (now with a dash instead of a space). The
465 old commands are now deprecated and may be removed in a future
468 add-inferior [-no-connection]
469 The add-inferior command now supports a "-no-connection" flag that
470 makes the new inferior start with no target connection associated.
471 By default, the new inferior inherits the target connection of the
472 current inferior. See also "info connections".
475 This command's output now includes a new "Connection" column
476 indicating which target connection an inferior is bound to. See
477 "info connections" above.
479 maint test-options require-delimiter
480 maint test-options unknown-is-error
481 maint test-options unknown-is-operand
482 maint show test-options-completion-result
483 Commands used by the testsuite to validate the command options
486 focus, winheight, +, -, >, <
487 These commands are now case-sensitive.
489 * New command options, command completion
491 GDB now has a standard infrastructure to support dash-style command
492 options ('-OPT'). One benefit is that commands that use it can
493 easily support completion of command line arguments. Try "CMD
494 -[TAB]" or "help CMD" to find options supported by a command. Over
495 time, we intend to migrate most commands to this infrastructure. A
496 number of commands got support for new command options in this
499 ** The "print" and "compile print" commands now support a number of
500 options that allow overriding relevant global print settings as
501 set by "set print" subcommands:
505 -array-indexes [on|off]
506 -elements NUMBER|unlimited
511 -repeats NUMBER|unlimited
512 -static-members [on|off]
517 Note that because the "print"/"compile print" commands accept
518 arbitrary expressions which may look like options (including
519 abbreviations), if you specify any command option, then you must
520 use a double dash ("--") to mark the end of argument processing.
522 ** The "backtrace" command now supports a number of options that
523 allow overriding relevant global print settings as set by "set
524 backtrace" and "set print" subcommands:
526 -entry-values no|only|preferred|if-needed|both|compact|default
527 -frame-arguments all|scalars|none
528 -raw-frame-arguments [on|off]
529 -frame-info auto|source-line|location|source-and-location
530 |location-and-address|short-location
534 In addition, the full/no-filters/hide qualifiers are now also
535 exposed as command options too:
541 ** The "frame apply", "tfaas" and "faas" commands similarly now
542 support the following options:
547 ** The new "info sources" options -dirname and -basename options
548 are using the standard '-OPT' infrastructure.
550 All options above can also be abbreviated. The argument of boolean
551 (on/off) options can be 0/1 too, and also the argument is assumed
552 "on" if omitted. This allows writing compact command invocations,
555 (gdb) p -ra -p -o 0 -- *myptr
557 The above is equivalent to:
559 (gdb) print -raw-values -pretty -object off -- *myptr
561 ** The "info types" command now supports the '-q' flag to disable
562 printing of some header information in a similar fashion to "info
563 variables" and "info functions".
565 ** The "info variables", "info functions", and "whereis" commands
566 now take a '-n' flag that excludes non-debug symbols (symbols
567 from the symbol table, not from the debug info such as DWARF)
570 * Completion improvements
572 ** GDB can now complete the options of the "thread apply all" and
573 "taas" commands, and their "-ascending" option can now be
576 ** GDB can now complete the options of the "info threads", "info
577 functions", "info variables", "info locals", and "info args"
580 ** GDB can now complete the options of the "compile file" and
581 "compile code" commands. The "compile file" command now
582 completes on filenames.
584 ** GDB can now complete the backtrace command's
585 "full/no-filters/hide" qualifiers.
587 * In settings, you can now abbreviate "unlimited".
589 E.g., "set print elements u" is now equivalent to "set print
595 This lists all the possible completions for the rest of the line, if it
596 were to be given as a command itself. This is intended for use by MI
597 frontends in cases when separate CLI and MI channels cannot be used.
599 -catch-throw, -catch-rethrow, and -catch-catch
600 These can be used to catch C++ exceptions in a similar fashion to
601 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
603 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
604 These commands are the MI equivalent of the CLI commands 'info
605 functions', 'info types', and 'info variables' respectively.
607 -symbol-info-modules, this is the MI equivalent of the CLI 'info
610 -symbol-info-module-functions and -symbol-info-module-variables.
611 These commands are the MI equivalent of the CLI commands 'info
612 module functions' and 'info module variables'.
616 ** The default version of the MI interpreter is now 3 (-i=mi3).
618 ** The output of information about multi-location breakpoints (which is
619 syntactically incorrect in MI 2) has changed in MI 3. This affects
620 the following commands and events:
624 - =breakpoint-created
625 - =breakpoint-modified
627 The -fix-multi-location-breakpoint-output command can be used to enable
628 this behavior with previous MI versions.
630 ** Backtraces and frames include a new optional field addr_flags which is
631 given after the addr field. On AArch64 this contains PAC if the address
632 has been masked in the frame. On all other targets the field is not
637 The testsuite now creates the files gdb.cmd (containing the arguments
638 used to launch GDB) and gdb.in (containing all the commands sent to
639 GDB) in the output directory for each test script. Multiple invocations
640 are appended with .1, .2, .3 etc.
642 * Building GDB and GDBserver now requires GNU make >= 3.82.
644 Using another implementation of the make program or an earlier version of
645 GNU make to build GDB or GDBserver is not supported.
647 * Building GDB now requires GNU readline >= 7.0.
649 GDB now bundles GNU readline 8.0, but if you choose to use
650 --with-system-readline, only readline >= 7.0 can be used.
652 * The TUI SingleKey keymap is now named "SingleKey". This can be used
653 from .inputrc to bind keys in this keymap. This feature is only
654 available when gdb is built against GNU readline 8.0 or later.
656 * Removed targets and native configurations
658 GDB no longer supports debugging the Cell Broadband Engine. This includes
659 both debugging standalone Cell/B.E. SPU applications and integrated debugging
660 of Cell/B.E. applications that use both the PPU and SPU architectures.
666 * Removed targets and native configurations
668 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
671 *** Changes in GDB 8.3
673 * GDB and GDBserver now support access to additional registers on
674 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
677 * GDB now has experimental support for the compilation and injection of
678 C++ source code into the inferior. This beta release does not include
679 support for several language features, such as templates, constructors,
682 This feature requires GCC 7.1 or higher built with libcp1.so
685 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
686 can be passed using the '[ADDRESS]:PORT' notation, or the regular
687 'ADDRESS:PORT' method.
689 * DWARF index cache: GDB can now automatically save indices of DWARF
690 symbols on disk to speed up further loading of the same binaries.
692 * Ada task switching is now supported on aarch64-elf targets when
693 debugging a program using the Ravenscar Profile. For more information,
694 see the "Tasking Support when using the Ravenscar Profile" section
695 in the GDB user manual.
697 * GDB in batch mode now exits with status 1 if the last command to be
700 * The RISC-V target now supports target descriptions.
702 * System call catchpoints now support system call aliases on FreeBSD.
703 When the ABI of a system call changes in FreeBSD, this is
704 implemented by leaving a compatibility system call using the old ABI
705 at the existing number and allocating a new system call number for
706 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
707 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
708 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
709 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
710 so that a system call catchpoint for the 'kevent' system call will
711 catch invocations of both the 'kevent' and 'freebsd11_kevent'
712 binaries. This ensures that 'kevent' system calls are caught for
713 binaries using either the old or new ABIs.
715 * Terminal styling is now available for the CLI and the TUI. GNU
716 Source Highlight can additionally be used to provide styling of
717 source code snippets. See the "set style" commands, below, for more
720 * Removed support for old demangling styles arm, edg, gnu, hp and
725 set debug compile-cplus-types
726 show debug compile-cplus-types
727 Control the display of debug output about type conversion in the
728 C++ compile feature. Commands have no effect while compiling
733 Control whether debug output about files/functions skipping is
736 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
737 Apply a command to some frames.
738 FLAG arguments allow to control what output to produce and how to handle
739 errors raised when applying COMMAND to a frame.
742 Apply a command to all threads (ignoring errors and empty output).
743 Shortcut for 'thread apply all -s COMMAND'.
746 Apply a command to all frames (ignoring errors and empty output).
747 Shortcut for 'frame apply all -s COMMAND'.
750 Apply a command to all frames of all threads (ignoring errors and empty
752 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
754 maint set dwarf unwinders (on|off)
755 maint show dwarf unwinders
756 Control whether DWARF unwinders can be used.
759 Display a list of open files for a process.
763 Changes to the "frame", "select-frame", and "info frame" CLI commands.
764 These commands all now take a frame specification which
765 is either a frame level, or one of the keywords 'level', 'address',
766 'function', or 'view' followed by a parameter. Selecting a frame by
767 address, or viewing a frame outside the current backtrace now
768 requires the use of a keyword. Selecting a frame by level is
769 unchanged. The MI comment "-stack-select-frame" is unchanged.
771 target remote FILENAME
772 target extended-remote FILENAME
773 If FILENAME is a Unix domain socket, GDB will attempt to connect
774 to this socket instead of opening FILENAME as a character device.
776 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
777 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
778 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
779 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
780 These commands can now print only the searched entities
781 matching the provided regexp(s), giving a condition
782 on the entity names or entity types. The flag -q disables
783 printing headers or informations messages.
789 These commands now determine the syntax for the shown entities
790 according to the language chosen by `set language'. In particular,
791 `set language auto' means to automatically choose the language of
794 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
795 The 'thread apply' command accepts new FLAG arguments.
796 FLAG arguments allow to control what output to produce and how to handle
797 errors raised when applying COMMAND to a thread.
799 set tui tab-width NCHARS
800 show tui tab-width NCHARS
801 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
803 set style enabled [on|off]
805 Enable or disable terminal styling. Styling is enabled by default
806 on most hosts, but disabled by default when in batch mode.
808 set style sources [on|off]
810 Enable or disable source code styling. Source code styling is
811 enabled by default, but only takes effect if styling in general is
812 enabled, and if GDB was linked with GNU Source Highlight.
814 set style filename foreground COLOR
815 set style filename background COLOR
816 set style filename intensity VALUE
817 Control the styling of file names.
819 set style function foreground COLOR
820 set style function background COLOR
821 set style function intensity VALUE
822 Control the styling of function names.
824 set style variable foreground COLOR
825 set style variable background COLOR
826 set style variable intensity VALUE
827 Control the styling of variable names.
829 set style address foreground COLOR
830 set style address background COLOR
831 set style address intensity VALUE
832 Control the styling of addresses.
836 ** The '-data-disassemble' MI command now accepts an '-a' option to
837 disassemble the whole function surrounding the given program
838 counter value or function name. Support for this feature can be
839 verified by using the "-list-features" command, which should
840 contain "data-disassemble-a-option".
842 ** Command responses and notifications that include a frame now include
843 the frame's architecture in a new "arch" attribute.
845 * New native configurations
847 GNU/Linux/RISC-V riscv*-*-linux*
848 FreeBSD/riscv riscv*-*-freebsd*
852 GNU/Linux/RISC-V riscv*-*-linux*
854 CSKY GNU/LINUX csky*-*-linux
855 FreeBSD/riscv riscv*-*-freebsd*
857 GNU/Linux/OpenRISC or1k*-*-linux*
861 GDB no longer supports native debugging on versions of MS-Windows
866 ** GDB no longer supports Python versions less than 2.6.
868 ** The gdb.Inferior type has a new 'progspace' property, which is the program
869 space associated to that inferior.
871 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
872 of objfiles associated to that program space.
874 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
875 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
878 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
879 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
880 correct and did not work properly.
882 ** The gdb.Value type has a new constructor, which is used to construct a
883 gdb.Value from a Python buffer object and a gdb.Type.
889 Enable or disable the undefined behavior sanitizer. This is
890 disabled by default, but passing --enable-ubsan=yes or
891 --enable-ubsan=auto to configure will enable it. Enabling this can
892 cause a performance penalty. The undefined behavior sanitizer was
893 first introduced in GCC 4.9.
895 *** Changes in GDB 8.2
897 * The 'set disassembler-options' command now supports specifying options
900 * The 'symbol-file' command now accepts an '-o' option to add a relative
901 offset to all sections.
903 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
904 a relative offset to all sections, but it allows to override the load
905 address of individual sections using '-s'.
907 * The 'add-symbol-file' command no longer requires the second argument
908 (address of the text section).
910 * The endianness used with the 'set endian auto' mode in the absence of
911 an executable selected for debugging is now the last endianness chosen
912 either by one of the 'set endian big' and 'set endian little' commands
913 or by inferring from the last executable used, rather than the startup
916 * The pager now allows a "c" response, meaning to disable the pager
917 for the rest of the current command.
919 * The commands 'info variables/functions/types' now show the source line
920 numbers of symbol definitions when available.
922 * 'info proc' now works on running processes on FreeBSD systems and core
923 files created on FreeBSD systems.
925 * C expressions can now use _Alignof, and C++ expressions can now use
928 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
929 the vector length while the process is running.
935 Control display of debugging info regarding the FreeBSD native target.
937 set|show varsize-limit
938 This new setting allows the user to control the maximum size of Ada
939 objects being printed when those objects have a variable type,
940 instead of that maximum size being hardcoded to 65536 bytes.
942 set|show record btrace cpu
943 Controls the processor to be used for enabling errata workarounds for
946 maint check libthread-db
947 Run integrity checks on the current inferior's thread debugging
950 maint set check-libthread-db (on|off)
951 maint show check-libthread-db
952 Control whether to run integrity checks on inferior specific thread
953 debugging libraries as they are loaded. The default is not to
958 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
960 ** The commands attached to a breakpoint can be set by assigning to
961 the breakpoint's "commands" field.
963 ** gdb.execute can now execute multi-line gdb commands.
965 ** The new functions gdb.convenience_variable and
966 gdb.set_convenience_variable can be used to get and set the value
967 of convenience variables.
969 ** A gdb.Parameter will no longer print the "set" help text on an
970 ordinary "set"; instead by default a "set" will be silent unless
971 the get_set_string method returns a non-empty string.
975 RiscV ELF riscv*-*-elf
977 * Removed targets and native configurations
979 m88k running OpenBSD m88*-*-openbsd*
980 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
981 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
982 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
984 * Aarch64/Linux hardware watchpoints improvements
986 Hardware watchpoints on unaligned addresses are now properly
987 supported when running Linux kernel 4.10 or higher: read and access
988 watchpoints are no longer spuriously missed, and all watchpoints
989 lengths between 1 and 8 bytes are supported. On older kernels,
990 watchpoints set on unaligned addresses are no longer missed, with
991 the tradeoff that there is a possibility of false hits being
996 --enable-codesign=CERT
997 This can be used to invoke "codesign -s CERT" after building gdb.
998 This option is useful on macOS, where code signing is required for
999 gdb to work properly.
1001 --disable-gdbcli has been removed
1002 This is now silently accepted, but does nothing.
1004 *** Changes in GDB 8.1
1006 * GDB now supports dynamically creating arbitrary register groups specified
1007 in XML target descriptions. This allows for finer grain grouping of
1008 registers on systems with a large amount of registers.
1010 * The 'ptype' command now accepts a '/o' flag, which prints the
1011 offsets and sizes of fields in a struct, like the pahole(1) tool.
1013 * New "--readnever" command line option instructs GDB to not read each
1014 symbol file's symbolic debug information. This makes startup faster
1015 but at the expense of not being able to perform symbolic debugging.
1016 This option is intended for use cases where symbolic debugging will
1017 not be used, e.g., when you only need to dump the debuggee's core.
1019 * GDB now uses the GNU MPFR library, if available, to emulate target
1020 floating-point arithmetic during expression evaluation when the target
1021 uses different floating-point formats than the host. At least version
1022 3.1 of GNU MPFR is required.
1024 * GDB now supports access to the guarded-storage-control registers and the
1025 software-based guarded-storage broadcast control registers on IBM z14.
1027 * On Unix systems, GDB now supports transmitting environment variables
1028 that are to be set or unset to GDBserver. These variables will
1029 affect the environment to be passed to the remote inferior.
1031 To inform GDB of environment variables that are to be transmitted to
1032 GDBserver, use the "set environment" command. Only user set
1033 environment variables are sent to GDBserver.
1035 To inform GDB of environment variables that are to be unset before
1036 the remote inferior is started by the GDBserver, use the "unset
1037 environment" command.
1039 * Completion improvements
1041 ** GDB can now complete function parameters in linespecs and
1042 explicit locations without quoting. When setting breakpoints,
1043 quoting around functions names to help with TAB-completion is
1044 generally no longer necessary. For example, this now completes
1047 (gdb) b function(in[TAB]
1048 (gdb) b function(int)
1050 Related, GDB is no longer confused with completing functions in
1051 C++ anonymous namespaces:
1054 (gdb) b (anonymous namespace)::[TAB][TAB]
1055 (anonymous namespace)::a_function()
1056 (anonymous namespace)::b_function()
1058 ** GDB now has much improved linespec and explicit locations TAB
1059 completion support, that better understands what you're
1060 completing and offers better suggestions. For example, GDB no
1061 longer offers data symbols as possible completions when you're
1062 setting a breakpoint.
1064 ** GDB now TAB-completes label symbol names.
1066 ** The "complete" command now mimics TAB completion accurately.
1068 * New command line options (gcore)
1071 Dump all memory mappings.
1073 * Breakpoints on C++ functions are now set on all scopes by default
1075 By default, breakpoints on functions/methods are now interpreted as
1076 specifying all functions with the given name ignoring missing
1077 leading scopes (namespaces and classes).
1079 For example, assuming a C++ program with symbols named:
1084 both commands "break func()" and "break B::func()" set a breakpoint
1087 You can use the new flag "-qualified" to override this. This makes
1088 GDB interpret the specified function name as a complete
1089 fully-qualified name instead. For example, using the same C++
1090 program, the "break -q B::func" command sets a breakpoint on
1091 "B::func", only. A parameter has been added to the Python
1092 gdb.Breakpoint constructor to achieve the same result when creating
1093 a breakpoint from Python.
1095 * Breakpoints on functions marked with C++ ABI tags
1097 GDB can now set breakpoints on functions marked with C++ ABI tags
1098 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1099 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1101 Functions with a C++11 abi tag are demangled/displayed like this:
1103 function[abi:cxx11](int)
1106 You can now set a breakpoint on such functions simply as if they had
1109 (gdb) b function(int)
1111 Or if you need to disambiguate between tags, like:
1113 (gdb) b function[abi:other_tag](int)
1115 Tab completion was adjusted accordingly as well.
1119 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1120 gdb.new_thread are emitted. See the manual for further
1121 description of these.
1123 ** A new function, "gdb.rbreak" has been added to the Python API.
1124 This function allows the setting of a large number of breakpoints
1125 via a regex pattern in Python. See the manual for further details.
1127 ** Python breakpoints can now accept explicit locations. See the
1128 manual for a further description of this feature.
1131 * New features in the GDB remote stub, GDBserver
1133 ** GDBserver is now able to start inferior processes with a
1134 specified initial working directory.
1136 The user can set the desired working directory to be used from
1137 GDB using the new "set cwd" command.
1139 ** New "--selftest" command line option runs some GDBserver self
1140 tests. These self tests are disabled in releases.
1142 ** On Unix systems, GDBserver now does globbing expansion and variable
1143 substitution in inferior command line arguments.
1145 This is done by starting inferiors using a shell, like GDB does.
1146 See "set startup-with-shell" in the user manual for how to disable
1147 this from GDB when using "target extended-remote". When using
1148 "target remote", you can disable the startup with shell by using the
1149 new "--no-startup-with-shell" GDBserver command line option.
1151 ** On Unix systems, GDBserver now supports receiving environment
1152 variables that are to be set or unset from GDB. These variables
1153 will affect the environment to be passed to the inferior.
1155 * When catching an Ada exception raised with a message, GDB now prints
1156 the message in the catchpoint hit notification. In GDB/MI mode, that
1157 information is provided as an extra field named "exception-message"
1158 in the *stopped notification.
1160 * Trait objects can now be inspected When debugging Rust code. This
1161 requires compiler support which will appear in Rust 1.24.
1163 * New remote packets
1165 QEnvironmentHexEncoded
1166 Inform GDBserver of an environment variable that is to be passed to
1167 the inferior when starting it.
1170 Inform GDBserver of an environment variable that is to be unset
1171 before starting the remote inferior.
1174 Inform GDBserver that the environment should be reset (i.e.,
1175 user-set environment variables should be unset).
1178 Indicates whether the inferior must be started with a shell or not.
1181 Tell GDBserver that the inferior to be started should use a specific
1184 * The "maintenance print c-tdesc" command now takes an optional
1185 argument which is the file name of XML target description.
1187 * The "maintenance selftest" command now takes an optional argument to
1188 filter the tests to be run.
1190 * The "enable", and "disable" commands now accept a range of
1191 breakpoint locations, e.g. "enable 1.3-5".
1196 Set and show the current working directory for the inferior.
1198 set|show compile-gcc
1199 Set and show compilation command used for compiling and injecting code
1200 with the 'compile' commands.
1202 set debug separate-debug-file
1203 show debug separate-debug-file
1204 Control the display of debug output about separate debug file search.
1206 set dump-excluded-mappings
1207 show dump-excluded-mappings
1208 Control whether mappings marked with the VM_DONTDUMP flag should be
1209 dumped when generating a core file.
1211 maint info selftests
1212 List the registered selftests.
1215 Start the debugged program stopping at the first instruction.
1218 Control display of debugging messages related to OpenRISC targets.
1220 set|show print type nested-type-limit
1221 Set and show the limit of nesting level for nested types that the
1222 type printer will show.
1224 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1227 * Safer/improved support for debugging with no debug info
1229 GDB no longer assumes functions with no debug information return
1232 This means that GDB now refuses to call such functions unless you
1233 tell it the function's type, by either casting the call to the
1234 declared return type, or by casting the function to a function
1235 pointer of the right type, and calling that:
1237 (gdb) p getenv ("PATH")
1238 'getenv' has unknown return type; cast the call to its declared return type
1239 (gdb) p (char *) getenv ("PATH")
1240 $1 = 0x7fffffffe "/usr/local/bin:/"...
1241 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1242 $2 = 0x7fffffffe "/usr/local/bin:/"...
1244 Similarly, GDB no longer assumes that global variables with no debug
1245 info have type 'int', and refuses to print the variable's value
1246 unless you tell it the variable's type:
1249 'var' has unknown type; cast it to its declared type
1253 * New native configurations
1255 FreeBSD/aarch64 aarch64*-*-freebsd*
1256 FreeBSD/arm arm*-*-freebsd*
1260 FreeBSD/aarch64 aarch64*-*-freebsd*
1261 FreeBSD/arm arm*-*-freebsd*
1262 OpenRISC ELF or1k*-*-elf
1264 * Removed targets and native configurations
1266 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1268 *** Changes in GDB 8.0
1270 * GDB now supports access to the PKU register on GNU/Linux. The register is
1271 added by the Memory Protection Keys for Userspace feature which will be
1272 available in future Intel CPUs.
1274 * GDB now supports C++11 rvalue references.
1278 ** New functions to start, stop and access a running btrace recording.
1279 ** Rvalue references are now supported in gdb.Type.
1281 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1284 * Building GDB and GDBserver now requires a C++11 compiler.
1286 For example, GCC 4.8 or later.
1288 It is no longer possible to build GDB or GDBserver with a C
1289 compiler. The --disable-build-with-cxx configure option has been
1292 * Building GDB and GDBserver now requires GNU make >= 3.81.
1294 It is no longer supported to build GDB or GDBserver with another
1295 implementation of the make program or an earlier version of GNU make.
1297 * Native debugging on MS-Windows supports command-line redirection
1299 Command-line arguments used for starting programs on MS-Windows can
1300 now include redirection symbols supported by native Windows shells,
1301 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1302 as "run", "start", and "set args", as well as the corresponding MI
1305 * Support for thread names on MS-Windows.
1307 GDB now catches and handles the special exception that programs
1308 running on MS-Windows use to assign names to threads in the
1311 * Support for Java programs compiled with gcj has been removed.
1313 * User commands now accept an unlimited number of arguments.
1314 Previously, only up to 10 was accepted.
1316 * The "eval" command now expands user-defined command arguments.
1318 This makes it easier to process a variable number of arguments:
1323 eval "print $arg%d", $i
1328 * Target descriptions can now describe registers for sparc32 and sparc64.
1330 * GDB now supports DWARF version 5 (debug information format).
1331 Its .debug_names index is not yet supported.
1333 * New native configurations
1335 FreeBSD/mips mips*-*-freebsd
1339 Synopsys ARC arc*-*-elf32
1340 FreeBSD/mips mips*-*-freebsd
1342 * Removed targets and native configurations
1344 Alpha running FreeBSD alpha*-*-freebsd*
1345 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1350 Erases all the flash memory regions reported by the target.
1352 maint print arc arc-instruction address
1353 Print internal disassembler information about instruction at a given address.
1357 set disassembler-options
1358 show disassembler-options
1359 Controls the passing of target specific information to the disassembler.
1360 If it is necessary to specify more than one disassembler option then
1361 multiple options can be placed together into a comma separated list.
1362 The default value is the empty string. Currently, the only supported
1363 targets are ARM, PowerPC and S/390.
1368 Erases all the flash memory regions reported by the target. This is
1369 equivalent to the CLI command flash-erase.
1371 -file-list-shared-libraries
1372 List the shared libraries in the program. This is
1373 equivalent to the CLI command "info shared".
1376 Catchpoints stopping the program when Ada exceptions are
1377 handled. This is equivalent to the CLI command "catch handlers".
1379 *** Changes in GDB 7.12
1381 * GDB and GDBserver now build with a C++ compiler by default.
1383 The --enable-build-with-cxx configure option is now enabled by
1384 default. One must now explicitly configure with
1385 --disable-build-with-cxx in order to build with a C compiler. This
1386 option will be removed in a future release.
1388 * GDBserver now supports recording btrace without maintaining an active
1391 * GDB now supports a negative repeat count in the 'x' command to examine
1392 memory backward from the given address. For example:
1395 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1396 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1397 (gdb) x/-5i 0x0000000000400580
1398 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1399 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1400 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1401 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1402 0x40057b <main(int, char**)+25>:
1403 callq 0x400536 <Func1(int, char const*)>
1405 * Fortran: Support structures with fields of dynamic types and
1406 arrays of dynamic types.
1408 * The symbol dumping maintenance commands have new syntax.
1409 maint print symbols [-pc address] [--] [filename]
1410 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1411 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1412 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1413 maint print msymbols [-objfile objfile] [--] [filename]
1415 * GDB now supports multibit bitfields and enums in target register
1418 * New Python-based convenience function $_as_string(val), which returns
1419 the textual representation of a value. This function is especially
1420 useful to obtain the text label of an enum value.
1422 * Intel MPX bound violation handling.
1424 Segmentation faults caused by a Intel MPX boundary violation
1425 now display the kind of violation (upper or lower), the memory
1426 address accessed and the memory bounds, along with the usual
1427 signal received and code location.
1431 Program received signal SIGSEGV, Segmentation fault
1432 Upper bound violation while accessing address 0x7fffffffc3b3
1433 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1434 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1436 * Rust language support.
1437 GDB now supports debugging programs written in the Rust programming
1438 language. See https://www.rust-lang.org/ for more information about
1441 * Support for running interpreters on specified input/output devices
1443 GDB now supports a new mechanism that allows frontends to provide
1444 fully featured GDB console views, as a better alternative to
1445 building such views on top of the "-interpreter-exec console"
1446 command. See the new "new-ui" command below. With that command,
1447 frontends can now start GDB in the traditional command-line mode
1448 running in an embedded terminal emulator widget, and create a
1449 separate MI interpreter running on a specified i/o device. In this
1450 way, GDB handles line editing, history, tab completion, etc. in the
1451 console all by itself, and the GUI uses the separate MI interpreter
1452 for its own control and synchronization, invisible to the command
1455 * The "catch syscall" command catches groups of related syscalls.
1457 The "catch syscall" command now supports catching a group of related
1458 syscalls using the 'group:' or 'g:' prefix.
1463 skip -gfile file-glob-pattern
1464 skip -function function
1465 skip -rfunction regular-expression
1466 A generalized form of the skip command, with new support for
1467 glob-style file names and regular expressions for function names.
1468 Additionally, a file spec and a function spec may now be combined.
1470 maint info line-table REGEXP
1471 Display the contents of GDB's internal line table data structure.
1474 Run any GDB unit tests that were compiled in.
1477 Start a new user interface instance running INTERP as interpreter,
1478 using the TTY file for input/output.
1482 ** gdb.Breakpoint objects have a new attribute "pending", which
1483 indicates whether the breakpoint is pending.
1484 ** Three new breakpoint-related events have been added:
1485 gdb.breakpoint_created, gdb.breakpoint_modified, and
1486 gdb.breakpoint_deleted.
1488 signal-event EVENTID
1489 Signal ("set") the given MS-Windows event object. This is used in
1490 conjunction with the Windows JIT debugging (AeDebug) support, where
1491 the OS suspends a crashing process until a debugger can attach to
1492 it. Resuming the crashing process, in order to debug it, is done by
1493 signalling an event.
1495 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1496 was added in GDBserver, including JIT compiling fast tracepoint's
1497 conditional expression bytecode into native code.
1499 * Support for various remote target protocols and ROM monitors has
1502 target m32rsdi Remote M32R debugging over SDI
1503 target mips MIPS remote debugging protocol
1504 target pmon PMON ROM monitor
1505 target ddb NEC's DDB variant of PMON for Vr4300
1506 target rockhopper NEC RockHopper variant of PMON
1507 target lsi LSI variant of PMO
1509 * Support for tracepoints and fast tracepoints on powerpc-linux,
1510 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1511 including JIT compiling fast tracepoint's conditional expression
1512 bytecode into native code.
1514 * MI async record =record-started now includes the method and format used for
1515 recording. For example:
1517 =record-started,thread-group="i1",method="btrace",format="bts"
1519 * MI async record =thread-selected now includes the frame field. For example:
1521 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1525 Andes NDS32 nds32*-*-elf
1527 *** Changes in GDB 7.11
1529 * GDB now supports debugging kernel-based threads on FreeBSD.
1531 * Per-inferior thread numbers
1533 Thread numbers are now per inferior instead of global. If you're
1534 debugging multiple inferiors, GDB displays thread IDs using a
1535 qualified INF_NUM.THR_NUM form. For example:
1539 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1540 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1541 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1542 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1544 As consequence, thread numbers as visible in the $_thread
1545 convenience variable and in Python's InferiorThread.num attribute
1546 are no longer unique between inferiors.
1548 GDB now maintains a second thread ID per thread, referred to as the
1549 global thread ID, which is the new equivalent of thread numbers in
1550 previous releases. See also $_gthread below.
1552 For backwards compatibility, MI's thread IDs always refer to global
1555 * Commands that accept thread IDs now accept the qualified
1556 INF_NUM.THR_NUM form as well. For example:
1559 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1562 * In commands that accept a list of thread IDs, you can now refer to
1563 all threads of an inferior using a star wildcard. GDB accepts
1564 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1565 refer to all threads of the current inferior. For example, "info
1568 * You can use "info threads -gid" to display the global thread ID of
1571 * The new convenience variable $_gthread holds the global number of
1574 * The new convenience variable $_inferior holds the number of the
1577 * GDB now displays the ID and name of the thread that hit a breakpoint
1578 or received a signal, if your program is multi-threaded. For
1581 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1582 Thread 1 "main" received signal SIGINT, Interrupt.
1584 * Record btrace now supports non-stop mode.
1586 * Support for tracepoints on aarch64-linux was added in GDBserver.
1588 * The 'record instruction-history' command now indicates speculative execution
1589 when using the Intel Processor Trace recording format.
1591 * GDB now allows users to specify explicit locations, bypassing
1592 the linespec parser. This feature is also available to GDB/MI
1595 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1596 GDB now is able to debug both AArch64 applications and ARM applications
1599 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1600 including JIT compiling fast tracepoint's conditional expression bytecode
1603 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1605 * "info threads", "info inferiors", "info display", "info checkpoints"
1606 and "maint info program-spaces" now list the corresponding items in
1607 ascending ID order, for consistency with all other "info" commands.
1609 * In Ada, the overloads selection menu has been enhanced to display the
1610 parameter types and the return types for the matching overloaded subprograms.
1614 maint set target-non-stop (on|off|auto)
1615 maint show target-non-stop
1616 Control whether GDB targets always operate in non-stop mode even if
1617 "set non-stop" is "off". The default is "auto", meaning non-stop
1618 mode is enabled if supported by the target.
1620 maint set bfd-sharing
1621 maint show bfd-sharing
1622 Control the reuse of bfd objects.
1625 show debug bfd-cache
1626 Control display of debugging info regarding bfd caching.
1630 Control display of debugging info regarding FreeBSD threads.
1632 set remote multiprocess-extensions-packet
1633 show remote multiprocess-extensions-packet
1634 Set/show the use of the remote protocol multiprocess extensions.
1636 set remote thread-events
1637 show remote thread-events
1638 Set/show the use of thread create/exit events.
1640 set ada print-signatures on|off
1641 show ada print-signatures"
1642 Control whether parameter types and return types are displayed in overloads
1643 selection menus. It is activated (@code{on}) by default.
1647 Controls the maximum size of memory, in bytes, that GDB will
1648 allocate for value contents. Prevents incorrect programs from
1649 causing GDB to allocate overly large buffers. Default is 64k.
1651 * The "disassemble" command accepts a new modifier: /s.
1652 It prints mixed source+disassembly like /m with two differences:
1653 - disassembled instructions are now printed in program order, and
1654 - and source for all relevant files is now printed.
1655 The "/m" option is now considered deprecated: its "source-centric"
1656 output hasn't proved useful in practice.
1658 * The "record instruction-history" command accepts a new modifier: /s.
1659 It behaves exactly like /m and prints mixed source+disassembly.
1661 * The "set scheduler-locking" command supports a new mode "replay".
1662 It behaves like "off" in record mode and like "on" in replay mode.
1664 * Support for various ROM monitors has been removed:
1666 target dbug dBUG ROM monitor for Motorola ColdFire
1667 target picobug Motorola picobug monitor
1668 target dink32 DINK32 ROM monitor for PowerPC
1669 target m32r Renesas M32R/D ROM monitor
1670 target mon2000 mon2000 ROM monitor
1671 target ppcbug PPCBUG ROM monitor for PowerPC
1673 * Support for reading/writing memory and extracting values on architectures
1674 whose memory is addressable in units of any integral multiple of 8 bits.
1677 Allows to break when an Ada exception is handled.
1679 * New remote packets
1682 Indicates that an exec system call was executed.
1684 exec-events feature in qSupported
1685 The qSupported packet allows GDB to request support for exec
1686 events using the new 'gdbfeature' exec-event, and the qSupported
1687 response can contain the corresponding 'stubfeature'. Set and
1688 show commands can be used to display whether these features are enabled.
1691 Equivalent to interrupting with the ^C character, but works in
1694 thread created stop reason (T05 create:...)
1695 Indicates that the thread was just created and is stopped at entry.
1697 thread exit stop reply (w exitcode;tid)
1698 Indicates that the thread has terminated.
1701 Enables/disables thread create and exit event reporting. For
1702 example, this is used in non-stop mode when GDB stops a set of
1703 threads and synchronously waits for the their corresponding stop
1704 replies. Without exit events, if one of the threads exits, GDB
1705 would hang forever not knowing that it should no longer expect a
1706 stop for that same thread.
1709 Indicates that there are no resumed threads left in the target (all
1710 threads are stopped). The remote stub reports support for this stop
1711 reply to GDB's qSupported query.
1714 Enables/disables catching syscalls from the inferior process.
1715 The remote stub reports support for this packet to GDB's qSupported query.
1717 syscall_entry stop reason
1718 Indicates that a syscall was just called.
1720 syscall_return stop reason
1721 Indicates that a syscall just returned.
1723 * Extended-remote exec events
1725 ** GDB now has support for exec events on extended-remote Linux targets.
1726 For such targets with Linux kernels 2.5.46 and later, this enables
1727 follow-exec-mode and exec catchpoints.
1729 set remote exec-event-feature-packet
1730 show remote exec-event-feature-packet
1731 Set/show the use of the remote exec event feature.
1733 * Thread names in remote protocol
1735 The reply to qXfer:threads:read may now include a name attribute for each
1738 * Target remote mode fork and exec events
1740 ** GDB now has support for fork and exec events on target remote mode
1741 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1742 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1743 fork and exec catchpoints.
1745 * Remote syscall events
1747 ** GDB now has support for catch syscall on remote Linux targets,
1748 currently enabled on x86/x86_64 architectures.
1750 set remote catch-syscall-packet
1751 show remote catch-syscall-packet
1752 Set/show the use of the remote catch syscall feature.
1756 ** The -var-set-format command now accepts the zero-hexadecimal
1757 format. It outputs data in hexadecimal format with zero-padding on the
1762 ** gdb.InferiorThread objects have a new attribute "global_num",
1763 which refers to the thread's global thread ID. The existing
1764 "num" attribute now refers to the thread's per-inferior number.
1765 See "Per-inferior thread numbers" above.
1766 ** gdb.InferiorThread objects have a new attribute "inferior", which
1767 is the Inferior object the thread belongs to.
1769 *** Changes in GDB 7.10
1771 * Support for process record-replay and reverse debugging on aarch64*-linux*
1772 targets has been added. GDB now supports recording of A64 instruction set
1773 including advance SIMD instructions.
1775 * Support for Sun's version of the "stabs" debug file format has been removed.
1777 * GDB now honors the content of the file /proc/PID/coredump_filter
1778 (PID is the process ID) on GNU/Linux systems. This file can be used
1779 to specify the types of memory mappings that will be included in a
1780 corefile. For more information, please refer to the manual page of
1781 "core(5)". GDB also has a new command: "set use-coredump-filter
1782 on|off". It allows to set whether GDB will read the content of the
1783 /proc/PID/coredump_filter file when generating a corefile.
1785 * The "info os" command on GNU/Linux can now display information on
1787 "info os cpus" Listing of all cpus/cores on the system
1789 * GDB has two new commands: "set serial parity odd|even|none" and
1790 "show serial parity". These allows to set or show parity for the
1793 * The "info source" command now displays the producer string if it was
1794 present in the debug info. This typically includes the compiler version
1795 and may include things like its command line arguments.
1797 * The "info dll", an alias of the "info sharedlibrary" command,
1798 is now available on all platforms.
1800 * Directory names supplied to the "set sysroot" commands may be
1801 prefixed with "target:" to tell GDB to access shared libraries from
1802 the target system, be it local or remote. This replaces the prefix
1803 "remote:". The default sysroot has been changed from "" to
1804 "target:". "remote:" is automatically converted to "target:" for
1805 backward compatibility.
1807 * The system root specified by "set sysroot" will be prepended to the
1808 filename of the main executable (if reported to GDB as absolute by
1809 the operating system) when starting processes remotely, and when
1810 attaching to already-running local or remote processes.
1812 * GDB now supports automatic location and retrieval of executable
1813 files from remote targets. Remote debugging can now be initiated
1814 using only a "target remote" or "target extended-remote" command
1815 (no "set sysroot" or "file" commands are required). See "New remote
1818 * The "dump" command now supports verilog hex format.
1820 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1822 * On GNU/Linux, GDB and gdbserver are now able to access executable
1823 and shared library files without a "set sysroot" command when
1824 attaching to processes running in different mount namespaces from
1825 the debugger. This makes it possible to attach to processes in
1826 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1827 See "New remote packets" below.
1829 * The "tui reg" command now provides completion for all of the
1830 available register groups, including target specific groups.
1832 * The HISTSIZE environment variable is no longer read when determining
1833 the size of GDB's command history. GDB now instead reads the dedicated
1834 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1835 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1840 ** Memory ports can now be unbuffered.
1844 ** gdb.Objfile objects have a new attribute "username",
1845 which is the name of the objfile as specified by the user,
1846 without, for example, resolving symlinks.
1847 ** You can now write frame unwinders in Python.
1848 ** gdb.Type objects have a new method "optimized_out",
1849 returning optimized out gdb.Value instance of this type.
1850 ** gdb.Value objects have new methods "reference_value" and
1851 "const_value" which return a reference to the value and a
1852 "const" version of the value respectively.
1856 maint print symbol-cache
1857 Print the contents of the symbol cache.
1859 maint print symbol-cache-statistics
1860 Print statistics of symbol cache usage.
1862 maint flush-symbol-cache
1863 Flush the contents of the symbol cache.
1867 Start branch trace recording using Branch Trace Store (BTS) format.
1870 Evaluate expression by using the compiler and print result.
1874 Explicit commands for enabling and disabling tui mode.
1877 set mpx bound on i386 and amd64
1878 Support for bound table investigation on Intel MPX enabled applications.
1882 Start branch trace recording using Intel Processor Trace format.
1885 Print information about branch tracing internals.
1887 maint btrace packet-history
1888 Print the raw branch tracing data.
1890 maint btrace clear-packet-history
1891 Discard the stored raw branch tracing data.
1894 Discard all branch tracing data. It will be fetched and processed
1895 anew by the next "record" command.
1900 Renamed from "set debug dwarf2-die".
1901 show debug dwarf-die
1902 Renamed from "show debug dwarf2-die".
1904 set debug dwarf-read
1905 Renamed from "set debug dwarf2-read".
1906 show debug dwarf-read
1907 Renamed from "show debug dwarf2-read".
1909 maint set dwarf always-disassemble
1910 Renamed from "maint set dwarf2 always-disassemble".
1911 maint show dwarf always-disassemble
1912 Renamed from "maint show dwarf2 always-disassemble".
1914 maint set dwarf max-cache-age
1915 Renamed from "maint set dwarf2 max-cache-age".
1916 maint show dwarf max-cache-age
1917 Renamed from "maint show dwarf2 max-cache-age".
1919 set debug dwarf-line
1920 show debug dwarf-line
1921 Control display of debugging info regarding DWARF line processing.
1924 show max-completions
1925 Set the maximum number of candidates to be considered during
1926 completion. The default value is 200. This limit allows GDB
1927 to avoid generating large completion lists, the computation of
1928 which can cause the debugger to become temporarily unresponsive.
1930 set history remove-duplicates
1931 show history remove-duplicates
1932 Control the removal of duplicate history entries.
1934 maint set symbol-cache-size
1935 maint show symbol-cache-size
1936 Control the size of the symbol cache.
1938 set|show record btrace bts buffer-size
1939 Set and show the size of the ring buffer used for branch tracing in
1941 The obtained size may differ from the requested size. Use "info
1942 record" to see the obtained buffer size.
1944 set debug linux-namespaces
1945 show debug linux-namespaces
1946 Control display of debugging info regarding Linux namespaces.
1948 set|show record btrace pt buffer-size
1949 Set and show the size of the ring buffer used for branch tracing in
1950 Intel Processor Trace format.
1951 The obtained size may differ from the requested size. Use "info
1952 record" to see the obtained buffer size.
1954 maint set|show btrace pt skip-pad
1955 Set and show whether PAD packets are skipped when computing the
1958 * The command 'thread apply all' can now support new option '-ascending'
1959 to call its specified command for all threads in ascending order.
1961 * Python/Guile scripting
1963 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1964 special section named `.debug_gdb_scripts'.
1966 * New remote packets
1968 qXfer:btrace-conf:read
1969 Return the branch trace configuration for the current thread.
1971 Qbtrace-conf:bts:size
1972 Set the requested ring buffer size for branch tracing in BTS format.
1975 Enable Intel Processor Trace-based branch tracing for the current
1976 process. The remote stub reports support for this packet to GDB's
1979 Qbtrace-conf:pt:size
1980 Set the requested ring buffer size for branch tracing in Intel Processor
1984 Indicates a memory breakpoint instruction was executed, irrespective
1985 of whether it was GDB that planted the breakpoint or the breakpoint
1986 is hardcoded in the program. This is required for correct non-stop
1990 Indicates the target stopped for a hardware breakpoint. This is
1991 required for correct non-stop mode operation.
1994 Return information about files on the remote system.
1996 qXfer:exec-file:read
1997 Return the full absolute name of the file that was executed to
1998 create a process running on the remote system.
2001 Select the filesystem on which vFile: operations with filename
2002 arguments will operate. This is required for GDB to be able to
2003 access files on remote targets where the remote stub does not
2004 share a common filesystem with the inferior(s).
2007 Indicates that a fork system call was executed.
2010 Indicates that a vfork system call was executed.
2012 vforkdone stop reason
2013 Indicates that a vfork child of the specified process has executed
2014 an exec or exit, allowing the vfork parent to resume execution.
2016 fork-events and vfork-events features in qSupported
2017 The qSupported packet allows GDB to request support for fork and
2018 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2019 and the qSupported response can contain the corresponding
2020 'stubfeatures'. Set and show commands can be used to display
2021 whether these features are enabled.
2023 * Extended-remote fork events
2025 ** GDB now has support for fork events on extended-remote Linux
2026 targets. For targets with Linux kernels 2.5.60 and later, this
2027 enables follow-fork-mode and detach-on-fork for both fork and
2028 vfork, as well as fork and vfork catchpoints.
2030 * The info record command now shows the recording format and the
2031 branch tracing configuration for the current thread when using
2032 the btrace record target.
2033 For the BTS format, it shows the ring buffer size.
2035 * GDB now has support for DTrace USDT (Userland Static Defined
2036 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2038 * GDB now supports access to vector registers on S/390 GNU/Linux
2041 * Removed command line options
2043 -xdb HP-UX XDB compatibility mode.
2045 * Removed targets and native configurations
2047 HP/PA running HP-UX hppa*-*-hpux*
2048 Itanium running HP-UX ia64-*-hpux*
2050 * New configure options
2053 This configure option allows the user to build GDB with support for
2054 Intel Processor Trace (default: auto). This requires libipt.
2056 --with-libipt-prefix=PATH
2057 Specify the path to the version of libipt that GDB should use.
2058 $PATH/include should contain the intel-pt.h header and
2059 $PATH/lib should contain the libipt.so library.
2061 *** Changes in GDB 7.9.1
2065 ** Xmethods can now specify a result type.
2067 *** Changes in GDB 7.9
2069 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2073 ** You can now access frame registers from Python scripts.
2074 ** New attribute 'producer' for gdb.Symtab objects.
2075 ** gdb.Objfile objects have a new attribute "progspace",
2076 which is the gdb.Progspace object of the containing program space.
2077 ** gdb.Objfile objects have a new attribute "owner".
2078 ** gdb.Objfile objects have a new attribute "build_id",
2079 which is the build ID generated when the file was built.
2080 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2081 ** A new event "gdb.clear_objfiles" has been added, triggered when
2082 selecting a new file to debug.
2083 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2084 ** New function gdb.lookup_objfile.
2086 New events which are triggered when GDB modifies the state of the
2089 ** gdb.events.inferior_call_pre: Function call is about to be made.
2090 ** gdb.events.inferior_call_post: Function call has just been made.
2091 ** gdb.events.memory_changed: A memory location has been altered.
2092 ** gdb.events.register_changed: A register has been altered.
2094 * New Python-based convenience functions:
2096 ** $_caller_is(name [, number_of_frames])
2097 ** $_caller_matches(regexp [, number_of_frames])
2098 ** $_any_caller_is(name [, number_of_frames])
2099 ** $_any_caller_matches(regexp [, number_of_frames])
2101 * GDB now supports the compilation and injection of source code into
2102 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2103 to compile the source code to object code, and if successful, inject
2104 and execute that code within the current context of the inferior.
2105 Currently the C language is supported. The commands used to
2106 interface with this new feature are:
2108 compile code [-raw|-r] [--] [source code]
2109 compile file [-raw|-r] filename
2113 demangle [-l language] [--] name
2114 Demangle "name" in the specified language, or the current language
2115 if elided. This command is renamed from the "maint demangle" command.
2116 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2117 as "maint demangler-warning".
2119 queue-signal signal-name-or-number
2120 Queue a signal to be delivered to the thread when it is resumed.
2122 add-auto-load-scripts-directory directory
2123 Add entries to the list of directories from which to load auto-loaded
2126 maint print user-registers
2127 List all currently available "user" registers.
2129 compile code [-r|-raw] [--] [source code]
2130 Compile, inject, and execute in the inferior the executable object
2131 code produced by compiling the provided source code.
2133 compile file [-r|-raw] filename
2134 Compile and inject into the inferior the executable object code
2135 produced by compiling the source code stored in the filename
2138 * On resume, GDB now always passes the signal the program had stopped
2139 for to the thread the signal was sent to, even if the user changed
2140 threads before resuming. Previously GDB would often (but not
2141 always) deliver the signal to the thread that happens to be current
2144 * Conversely, the "signal" command now consistently delivers the
2145 requested signal to the current thread. GDB now asks for
2146 confirmation if the program had stopped for a signal and the user
2147 switched threads meanwhile.
2149 * "breakpoint always-inserted" modes "off" and "auto" merged.
2151 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2152 won't remove breakpoints from the target until all threads stop,
2153 even in non-stop mode. The "auto" mode has been removed, and "off"
2154 is now the default mode.
2158 set debug symbol-lookup
2159 show debug symbol-lookup
2160 Control display of debugging info regarding symbol lookup.
2164 ** The -list-thread-groups command outputs an exit-code field for
2165 inferiors that have exited.
2169 MIPS SDE mips*-sde*-elf*
2173 Support for these obsolete configurations has been removed.
2175 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2176 SGI Irix-5.x mips-*-irix5*
2177 SGI Irix-6.x mips-*-irix6*
2178 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2179 VAX running Ultrix vax-*-ultrix*
2181 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2182 and "assf"), have been removed. Use the "sharedlibrary" command, or
2183 its alias "share", instead.
2185 *** Changes in GDB 7.8
2187 * New command line options
2190 This is an alias for the --data-directory option.
2192 * GDB supports printing and modifying of variable length automatic arrays
2193 as specified in ISO C99.
2195 * The ARM simulator now supports instruction level tracing
2196 with or without disassembly.
2200 GDB now has support for scripting using Guile. Whether this is
2201 available is determined at configure time.
2202 Guile version 2.0 or greater is required.
2203 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2205 * New commands (for set/show, see "New options" below)
2209 Invoke CODE by passing it to the Guile interpreter.
2213 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2215 info auto-load guile-scripts [regexp]
2216 Print the list of automatically loaded Guile scripts.
2218 * The source command is now capable of sourcing Guile scripts.
2219 This feature is dependent on the debugger being built with Guile support.
2223 set print symbol-loading (off|brief|full)
2224 show print symbol-loading
2225 Control whether to print informational messages when loading symbol
2226 information for a file. The default is "full", but when debugging
2227 programs with large numbers of shared libraries the amount of output
2228 becomes less useful.
2230 set guile print-stack (none|message|full)
2231 show guile print-stack
2232 Show a stack trace when an error is encountered in a Guile script.
2234 set auto-load guile-scripts (on|off)
2235 show auto-load guile-scripts
2236 Control auto-loading of Guile script files.
2238 maint ada set ignore-descriptive-types (on|off)
2239 maint ada show ignore-descriptive-types
2240 Control whether the debugger should ignore descriptive types in Ada
2241 programs. The default is not to ignore the descriptive types. See
2242 the user manual for more details on descriptive types and the intended
2243 usage of this option.
2245 set auto-connect-native-target
2247 Control whether GDB is allowed to automatically connect to the
2248 native target for the run, attach, etc. commands when not connected
2249 to any target yet. See also "target native" below.
2251 set record btrace replay-memory-access (read-only|read-write)
2252 show record btrace replay-memory-access
2253 Control what memory accesses are allowed during replay.
2255 maint set target-async (on|off)
2256 maint show target-async
2257 This controls whether GDB targets operate in synchronous or
2258 asynchronous mode. Normally the default is asynchronous, if it is
2259 available; but this can be changed to more easily debug problems
2260 occurring only in synchronous mode.
2262 set mi-async (on|off)
2264 Control whether MI asynchronous mode is preferred. This supersedes
2265 "set target-async" of previous GDB versions.
2267 * "set target-async" is deprecated as a CLI option and is now an alias
2268 for "set mi-async" (only puts MI into async mode).
2270 * Background execution commands (e.g., "c&", "s&", etc.) are now
2271 possible ``out of the box'' if the target supports them. Previously
2272 the user would need to explicitly enable the possibility with the
2273 "set target-async on" command.
2275 * New features in the GDB remote stub, GDBserver
2277 ** New option --debug-format=option1[,option2,...] allows one to add
2278 additional text to each output. At present only timestamps
2279 are supported: --debug-format=timestamps.
2280 Timestamps can also be turned on with the
2281 "monitor set debug-format timestamps" command from GDB.
2283 * The 'record instruction-history' command now starts counting instructions
2284 at one. This also affects the instruction ranges reported by the
2285 'record function-call-history' command when given the /i modifier.
2287 * The command 'record function-call-history' supports a new modifier '/c' to
2288 indent the function names based on their call stack depth.
2289 The fields for the '/i' and '/l' modifier have been reordered.
2290 The source line range is now prefixed with 'at'.
2291 The instruction range is now prefixed with 'inst'.
2292 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2293 "record instruction-history" and "list" commands.
2295 * The ranges given as arguments to the 'record function-call-history' and
2296 'record instruction-history' commands are now inclusive.
2298 * The btrace record target now supports the 'record goto' command.
2299 For locations inside the execution trace, the back trace is computed
2300 based on the information stored in the execution trace.
2302 * The btrace record target supports limited reverse execution and replay.
2303 The target does not record data and therefore does not allow reading
2304 memory or registers.
2306 * The "catch syscall" command now works on s390*-linux* targets.
2308 * The "compare-sections" command is no longer specific to target
2309 remote. It now works with all targets.
2311 * All native targets are now consistently called "native".
2312 Consequently, the "target child", "target GNU", "target djgpp",
2313 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2314 commands have been replaced with "target native". The QNX/NTO port
2315 leaves the "procfs" target in place and adds a "native" target for
2316 consistency with other ports. The impact on users should be minimal
2317 as these commands previously either throwed an error, or were
2318 no-ops. The target's name is visible in the output of the following
2319 commands: "help target", "info target", "info files", "maint print
2322 * The "target native" command now connects to the native target. This
2323 can be used to launch native programs even when "set
2324 auto-connect-native-target" is set to off.
2326 * GDB now supports access to Intel MPX registers on GNU/Linux.
2328 * Support for Intel AVX-512 registers on GNU/Linux.
2329 Support displaying and modifying Intel AVX-512 registers
2330 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2332 * New remote packets
2334 qXfer:btrace:read's annex
2335 The qXfer:btrace:read packet supports a new annex 'delta' to read
2336 branch trace incrementally.
2340 ** Valid Python operations on gdb.Value objects representing
2341 structs/classes invoke the corresponding overloaded operators if
2343 ** New `Xmethods' feature in the Python API. Xmethods are
2344 additional methods or replacements for existing methods of a C++
2345 class. This feature is useful for those cases where a method
2346 defined in C++ source code could be inlined or optimized out by
2347 the compiler, making it unavailable to GDB.
2350 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2352 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2353 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2354 its alias "share", instead.
2356 * The commands "set remotebaud" and "show remotebaud" are no longer
2357 supported. Use "set serial baud" and "show serial baud" (respectively)
2362 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2363 target-async". The latter is left as a deprecated alias of the
2364 former for backward compatibility. If the target supports it,
2365 CLI background execution commands are now always possible by
2366 default, independently of whether the frontend stated a
2367 preference for asynchronous execution with "-gdb-set mi-async".
2368 Previously "-gdb-set target-async off" affected both MI execution
2369 commands and CLI execution commands.
2371 *** Changes in GDB 7.7
2373 * Improved support for process record-replay and reverse debugging on
2374 arm*-linux* targets. Support for thumb32 and syscall instruction
2375 recording has been added.
2377 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2379 * GDB now supports Fission DWP file format version 2.
2380 http://gcc.gnu.org/wiki/DebugFission
2382 * New convenience function "$_isvoid", to check whether an expression
2383 is void. A void expression is an expression where the type of the
2384 result is "void". For example, some convenience variables may be
2385 "void" when evaluated (e.g., "$_exitcode" before the execution of
2386 the program being debugged; or an undefined convenience variable).
2387 Another example, when calling a function whose return type is
2390 * The "maintenance print objfiles" command now takes an optional regexp.
2392 * The "catch syscall" command now works on arm*-linux* targets.
2394 * GDB now consistently shows "<not saved>" when printing values of
2395 registers the debug info indicates have not been saved in the frame
2396 and there's nowhere to retrieve them from
2397 (callee-saved/call-clobbered registers):
2402 (gdb) info registers rax
2405 Before, the former would print "<optimized out>", and the latter
2406 "*value not available*".
2408 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2413 ** Frame filters and frame decorators have been added.
2414 ** Temporary breakpoints are now supported.
2415 ** Line tables representation has been added.
2416 ** New attribute 'parent_type' for gdb.Field objects.
2417 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2418 ** New attribute 'name' for gdb.Type objects.
2422 Nios II ELF nios2*-*-elf
2423 Nios II GNU/Linux nios2*-*-linux
2424 Texas Instruments MSP430 msp430*-*-elf
2426 * Removed native configurations
2428 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2429 been removed. ELF variants of these configurations are kept supported.
2431 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2432 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2433 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2434 i[34567]86-*-openbsd3.[0-3]
2435 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2436 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2437 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2441 Like "catch throw", but catches a re-thrown exception.
2442 maint check-psymtabs
2443 Renamed from old "maint check-symtabs".
2445 Perform consistency checks on symtabs.
2446 maint expand-symtabs
2447 Expand symtabs matching an optional regexp.
2450 Display the details of GDB configure-time options.
2452 maint set|show per-command
2453 maint set|show per-command space
2454 maint set|show per-command time
2455 maint set|show per-command symtab
2456 Enable display of per-command gdb resource usage.
2458 remove-symbol-file FILENAME
2459 remove-symbol-file -a ADDRESS
2460 Remove a symbol file added via add-symbol-file. The file to remove
2461 can be identified by its filename or by an address that lies within
2462 the boundaries of this symbol file in memory.
2465 info exceptions REGEXP
2466 Display the list of Ada exceptions defined in the program being
2467 debugged. If provided, only the exceptions whose names match REGEXP
2472 set debug symfile off|on
2474 Control display of debugging info regarding reading symbol files and
2475 symbol tables within those files
2477 set print raw frame-arguments
2478 show print raw frame-arguments
2479 Set/show whether to print frame arguments in raw mode,
2480 disregarding any defined pretty-printers.
2482 set remote trace-status-packet
2483 show remote trace-status-packet
2484 Set/show the use of remote protocol qTStatus packet.
2488 Control display of debugging messages related to Nios II targets.
2492 Control whether target-assisted range stepping is enabled.
2494 set startup-with-shell
2495 show startup-with-shell
2496 Specifies whether Unix child processes are started via a shell or
2501 Use the target memory cache for accesses to the code segment. This
2502 improves performance of remote debugging (particularly disassembly).
2504 * You can now use a literal value 'unlimited' for options that
2505 interpret 0 or -1 as meaning "unlimited". E.g., "set
2506 trace-buffer-size unlimited" is now an alias for "set
2507 trace-buffer-size -1" and "set height unlimited" is now an alias for
2510 * The "set debug symtab-create" debugging option of GDB has been changed to
2511 accept a verbosity level. 0 means "off", 1 provides basic debugging
2512 output, and values of 2 or greater provides more verbose output.
2514 * New command-line options
2516 Display the details of GDB configure-time options.
2518 * The command 'tsave' can now support new option '-ctf' to save trace
2519 buffer in Common Trace Format.
2521 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2524 * GDB now implements the C++ 'typeid' operator.
2526 * The new convenience variable $_exception holds the exception being
2527 thrown or caught at an exception-related catchpoint.
2529 * The exception-related catchpoints, like "catch throw", now accept a
2530 regular expression which can be used to filter exceptions by type.
2532 * The new convenience variable $_exitsignal is automatically set to
2533 the terminating signal number when the program being debugged dies
2534 due to an uncaught signal.
2538 ** All MI commands now accept an optional "--language" option.
2539 Support for this feature can be verified by using the "-list-features"
2540 command, which should contain "language-option".
2542 ** The new command -info-gdb-mi-command allows the user to determine
2543 whether a GDB/MI command is supported or not.
2545 ** The "^error" result record returned when trying to execute an undefined
2546 GDB/MI command now provides a variable named "code" whose content is the
2547 "undefined-command" error code. Support for this feature can be verified
2548 by using the "-list-features" command, which should contain
2549 "undefined-command-error-code".
2551 ** The -trace-save MI command can optionally save trace buffer in Common
2554 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2556 ** The command -data-list-register-values now accepts an optional
2557 "--skip-unavailable" option. When used, only the available registers
2560 ** The new command -trace-frame-collected dumps collected variables,
2561 computed expressions, tvars, memory and registers in a traceframe.
2563 ** The commands -stack-list-locals, -stack-list-arguments and
2564 -stack-list-variables now accept an option "--skip-unavailable".
2565 When used, only the available locals or arguments are displayed.
2567 ** The -exec-run command now accepts an optional "--start" option.
2568 When used, the command follows the same semantics as the "start"
2569 command, stopping the program's execution at the start of its
2570 main subprogram. Support for this feature can be verified using
2571 the "-list-features" command, which should contain
2572 "exec-run-start-option".
2574 ** The new commands -catch-assert and -catch-exceptions insert
2575 catchpoints stopping the program when Ada exceptions are raised.
2577 ** The new command -info-ada-exceptions provides the equivalent of
2578 the new "info exceptions" command.
2580 * New system-wide configuration scripts
2581 A GDB installation now provides scripts suitable for use as system-wide
2582 configuration scripts for the following systems:
2586 * GDB now supports target-assigned range stepping with remote targets.
2587 This improves the performance of stepping source lines by reducing
2588 the number of control packets from/to GDB. See "New remote packets"
2591 * GDB now understands the element 'tvar' in the XML traceframe info.
2592 It has the id of the collected trace state variables.
2594 * On S/390 targets that provide the transactional-execution feature,
2595 the program interruption transaction diagnostic block (TDB) is now
2596 represented as a number of additional "registers" in GDB.
2598 * New remote packets
2602 The vCont packet supports a new 'r' action, that tells the remote
2603 stub to step through an address range itself, without GDB
2604 involvemement at each single-step.
2606 qXfer:libraries-svr4:read's annex
2607 The previously unused annex of the qXfer:libraries-svr4:read packet
2608 is now used to support passing an argument list. The remote stub
2609 reports support for this argument list to GDB's qSupported query.
2610 The defined arguments are "start" and "prev", used to reduce work
2611 necessary for library list updating, resulting in significant
2614 * New features in the GDB remote stub, GDBserver
2616 ** GDBserver now supports target-assisted range stepping. Currently
2617 enabled on x86/x86_64 GNU/Linux targets.
2619 ** GDBserver now adds element 'tvar' in the XML in the reply to
2620 'qXfer:traceframe-info:read'. It has the id of the collected
2621 trace state variables.
2623 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2626 * New 'z' formatter for printing and examining memory, this displays the
2627 value as hexadecimal zero padded on the left to the size of the type.
2629 * GDB can now use Windows x64 unwinding data.
2631 * The "set remotebaud" command has been replaced by "set serial baud".
2632 Similarly, "show remotebaud" has been replaced by "show serial baud".
2633 The "set remotebaud" and "show remotebaud" commands are still available
2634 to provide backward compatibility with older versions of GDB.
2636 *** Changes in GDB 7.6
2638 * Target record has been renamed to record-full.
2639 Record/replay is now enabled with the "record full" command.
2640 This also affects settings that are associated with full record/replay
2641 that have been moved from "set/show record" to "set/show record full":
2643 set|show record full insn-number-max
2644 set|show record full stop-at-limit
2645 set|show record full memory-query
2647 * A new record target "record-btrace" has been added. The new target
2648 uses hardware support to record the control-flow of a process. It
2649 does not support replaying the execution, but it implements the
2650 below new commands for investigating the recorded execution log.
2651 This new recording method can be enabled using:
2655 The "record-btrace" target is only available on Intel Atom processors
2656 and requires a Linux kernel 2.6.32 or later.
2658 * Two new commands have been added for record/replay to give information
2659 about the recorded execution without having to replay the execution.
2660 The commands are only supported by "record btrace".
2662 record instruction-history prints the execution history at
2663 instruction granularity
2665 record function-call-history prints the execution history at
2666 function granularity
2668 * New native configurations
2670 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2671 FreeBSD/powerpc powerpc*-*-freebsd
2672 x86_64/Cygwin x86_64-*-cygwin*
2673 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2677 ARM AArch64 aarch64*-*-elf
2678 ARM AArch64 GNU/Linux aarch64*-*-linux
2679 Lynx 178 PowerPC powerpc-*-lynx*178
2680 x86_64/Cygwin x86_64-*-cygwin*
2681 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2683 * If the configured location of system.gdbinit file (as given by the
2684 --with-system-gdbinit option at configure time) is in the
2685 data-directory (as specified by --with-gdb-datadir at configure
2686 time) or in one of its subdirectories, then GDB will look for the
2687 system-wide init file in the directory specified by the
2688 --data-directory command-line option.
2690 * New command line options:
2692 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2693 other initialization files, unlike -nx which disables all of them.
2695 * Removed command line options
2697 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2700 * The 'ptype' and 'whatis' commands now accept an argument to control
2703 * 'info proc' now works on some core files.
2707 ** Vectors can be created with gdb.Type.vector.
2709 ** Python's atexit.register now works in GDB.
2711 ** Types can be pretty-printed via a Python API.
2713 ** Python 3 is now supported (in addition to Python 2.4 or later)
2715 ** New class gdb.Architecture exposes GDB's internal representation
2716 of architecture in the Python API.
2718 ** New method Frame.architecture returns the gdb.Architecture object
2719 corresponding to the frame's architecture.
2721 * New Python-based convenience functions:
2723 ** $_memeq(buf1, buf2, length)
2724 ** $_streq(str1, str2)
2726 ** $_regex(str, regex)
2728 * The 'cd' command now defaults to using '~' (the home directory) if not
2731 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2732 default for GCC since November 2000.
2734 * The command 'forward-search' can now be abbreviated as 'fo'.
2736 * The command 'info tracepoints' can now display 'installed on target'
2737 or 'not installed on target' for each non-pending location of tracepoint.
2739 * New configure options
2741 --enable-libmcheck/--disable-libmcheck
2742 By default, development versions are built with -lmcheck on hosts
2743 that support it, in order to help track memory corruption issues.
2744 Release versions, on the other hand, are built without -lmcheck
2745 by default. The --enable-libmcheck/--disable-libmcheck configure
2746 options allow the user to override that default.
2747 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2748 This configure option allows the user to build GDB with
2749 libbabeltrace using which GDB can read Common Trace Format data.
2751 * New commands (for set/show, see "New options" below)
2754 Catch signals. This is similar to "handle", but allows commands and
2755 conditions to be attached.
2758 List the BFDs known to GDB.
2760 python-interactive [command]
2762 Start a Python interactive prompt, or evaluate the optional command
2763 and print the result of expressions.
2766 "py" is a new alias for "python".
2768 enable type-printer [name]...
2769 disable type-printer [name]...
2770 Enable or disable type printers.
2774 ** For the Renesas Super-H architecture, the "regs" command has been removed
2775 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2780 set print type methods (on|off)
2781 show print type methods
2782 Control whether method declarations are displayed by "ptype".
2783 The default is to show them.
2785 set print type typedefs (on|off)
2786 show print type typedefs
2787 Control whether typedef definitions are displayed by "ptype".
2788 The default is to show them.
2790 set filename-display basename|relative|absolute
2791 show filename-display
2792 Control the way in which filenames is displayed.
2793 The default is "relative", which preserves previous behavior.
2795 set trace-buffer-size
2796 show trace-buffer-size
2797 Request target to change the size of trace buffer.
2799 set remote trace-buffer-size-packet auto|on|off
2800 show remote trace-buffer-size-packet
2801 Control the use of the remote protocol `QTBuffer:size' packet.
2805 Control display of debugging messages related to ARM AArch64.
2808 set debug coff-pe-read
2809 show debug coff-pe-read
2810 Control display of debugging messages related to reading of COFF/PE
2815 Control display of debugging messages related to Mach-O symbols
2818 set debug notification
2819 show debug notification
2820 Control display of debugging info for async remote notification.
2824 ** Command parameter changes are now notified using new async record
2825 "=cmd-param-changed".
2826 ** Trace frame changes caused by command "tfind" are now notified using
2827 new async record "=traceframe-changed".
2828 ** The creation, deletion and modification of trace state variables
2829 are now notified using new async records "=tsv-created",
2830 "=tsv-deleted" and "=tsv-modified".
2831 ** The start and stop of process record are now notified using new
2832 async record "=record-started" and "=record-stopped".
2833 ** Memory changes are now notified using new async record
2835 ** The data-disassemble command response will include a "fullname" field
2836 containing the absolute file name when source has been requested.
2837 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2838 command, to allow pattern filling of memory areas.
2839 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2840 library load/unload events.
2841 ** The response to breakpoint commands and breakpoint async records
2842 includes an "installed" field containing a boolean state about each
2843 non-pending tracepoint location is whether installed on target or not.
2844 ** Output of the "-trace-status" command includes a "trace-file" field
2845 containing the name of the trace file being examined. This field is
2846 optional, and only present when examining a trace file.
2847 ** The "fullname" field is now always present along with the "file" field,
2848 even if the file cannot be found by GDB.
2850 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2851 You must have the LZMA library available when configuring GDB for this
2852 feature to be enabled. For more information, see:
2853 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2855 * New remote packets
2858 Set the size of trace buffer. The remote stub reports support for this
2859 packet to gdb's qSupported query.
2862 Enable Branch Trace Store (BTS)-based branch tracing for the current
2863 thread. The remote stub reports support for this packet to gdb's
2867 Disable branch tracing for the current thread. The remote stub reports
2868 support for this packet to gdb's qSupported query.
2871 Read the traced branches for the current thread. The remote stub
2872 reports support for this packet to gdb's qSupported query.
2874 *** Changes in GDB 7.5
2876 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2877 for more x32 ABI info.
2879 * GDB now supports access to MIPS DSP registers on Linux targets.
2881 * GDB now supports debugging microMIPS binaries.
2883 * The "info os" command on GNU/Linux can now display information on
2884 several new classes of objects managed by the operating system:
2885 "info os procgroups" lists process groups
2886 "info os files" lists file descriptors
2887 "info os sockets" lists internet-domain sockets
2888 "info os shm" lists shared-memory regions
2889 "info os semaphores" lists semaphores
2890 "info os msg" lists message queues
2891 "info os modules" lists loaded kernel modules
2893 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2894 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2895 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2896 options and inspect the probe arguments using the new $_probe_arg family
2897 of convenience variables. You can obtain more information about SystemTap
2898 in <http://sourceware.org/systemtap/>.
2900 * GDB now supports reversible debugging on ARM, it allows you to
2901 debug basic ARM and THUMB instructions, and provides
2902 record/replay support.
2904 * The option "symbol-reloading" has been deleted as it is no longer used.
2908 ** GDB commands implemented in Python can now be put in command class
2911 ** The "maint set python print-stack on|off" is now deleted.
2913 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2914 apply "flag enum"-style pretty-printing to any enum.
2916 ** gdb.lookup_symbol can now work when there is no current frame.
2918 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2919 the source at which the symbol was defined.
2921 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2922 method 'value'. The former indicates whether the symbol needs a
2923 frame in order to compute its value, and the latter computes the
2926 ** A new method 'referenced_value' on gdb.Value objects which can
2927 dereference pointer as well as C++ reference values.
2929 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2930 which return the global and static blocks (as gdb.Block objects),
2931 of the underlying symbol table, respectively.
2933 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2934 object associated with a PC value.
2936 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2937 of the address range occupied by code for the current source line.
2939 * Go language support.
2940 GDB now supports debugging programs written in the Go programming
2943 * GDBserver now supports stdio connections.
2944 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2946 * The binary "gdbtui" can no longer be built or installed.
2947 Use "gdb -tui" instead.
2949 * GDB will now print "flag" enums specially. A flag enum is one where
2950 all the enumerator values have no bits in common when pairwise
2951 "and"ed. When printing a value whose type is a flag enum, GDB will
2952 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2953 (gdb) print (enum E) 3
2956 * The filename part of a linespec will now match trailing components
2957 of a source file name. For example, "break gcc/expr.c:1000" will
2958 now set a breakpoint in build/gcc/expr.c, but not
2959 build/libcpp/expr.c.
2961 * The "info proc" and "generate-core-file" commands will now also
2962 work on remote targets connected to GDBserver on Linux.
2964 * The command "info catch" has been removed. It has been disabled
2965 since December 2007.
2967 * The "catch exception" and "catch assert" commands now accept
2968 a condition at the end of the command, much like the "break"
2969 command does. For instance:
2971 (gdb) catch exception Constraint_Error if Barrier = True
2973 Previously, it was possible to add a condition to such catchpoints,
2974 but it had to be done as a second step, after the catchpoint had been
2975 created, using the "condition" command.
2977 * The "info static-tracepoint-marker" command will now also work on
2978 native Linux targets with in-process agent.
2980 * GDB can now set breakpoints on inlined functions.
2982 * The .gdb_index section has been updated to include symbols for
2983 inlined functions. GDB will ignore older .gdb_index sections by
2984 default, which could cause symbol files to be loaded more slowly
2985 until their .gdb_index sections can be recreated. The new command
2986 "set use-deprecated-index-sections on" will cause GDB to use any older
2987 .gdb_index sections it finds. This will restore performance, but the
2988 ability to set breakpoints on inlined functions will be lost in symbol
2989 files with older .gdb_index sections.
2991 The .gdb_index section has also been updated to record more information
2992 about each symbol. This speeds up the "info variables", "info functions"
2993 and "info types" commands when used with programs having the .gdb_index
2994 section, as well as speeding up debugging with shared libraries using
2995 the .gdb_index section.
2997 * Ada support for GDB/MI Variable Objects has been added.
2999 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3004 ** New command -info-os is the MI equivalent of "info os".
3006 ** Output logs ("set logging" and related) now include MI output.
3010 ** "set use-deprecated-index-sections on|off"
3011 "show use-deprecated-index-sections on|off"
3012 Controls the use of deprecated .gdb_index sections.
3014 ** "catch load" and "catch unload" can be used to stop when a shared
3015 library is loaded or unloaded, respectively.
3017 ** "enable count" can be used to auto-disable a breakpoint after
3020 ** "info vtbl" can be used to show the virtual method tables for
3021 C++ and Java objects.
3023 ** "explore" and its sub commands "explore value" and "explore type"
3024 can be used to recursively explore values and types of
3025 expressions. These commands are available only if GDB is
3026 configured with '--with-python'.
3028 ** "info auto-load" shows status of all kinds of auto-loaded files,
3029 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3030 sequences of commands files, "info auto-load python-scripts"
3031 shows status of auto-loading Python script files,
3032 "info auto-load local-gdbinit" shows status of loading init file
3033 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3034 status of inferior specific thread debugging shared library loading.
3036 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3037 and "show auto-load-scripts" commands have been deprecated, use their
3038 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3039 and "show auto-load python-scripts" counterparts instead.
3041 ** "dprintf location,format,args..." creates a dynamic printf, which
3042 is basically a breakpoint that does a printf and immediately
3043 resumes your program's execution, so it is like a printf that you
3044 can insert dynamically at runtime instead of at compiletime.
3046 ** "set print symbol"
3048 Controls whether GDB attempts to display the symbol, if any,
3049 corresponding to addresses it prints. This defaults to "on", but
3050 you can set it to "off" to restore GDB's previous behavior.
3052 * Deprecated commands
3054 ** For the Renesas Super-H architecture, the "regs" command has been
3055 deprecated, and "info all-registers" should be used instead.
3059 Renesas RL78 rl78-*-elf
3060 HP OpenVMS ia64 ia64-hp-openvms*
3062 * GDBserver supports evaluation of breakpoint conditions. When
3063 support is advertised by GDBserver, GDB may be told to send the
3064 breakpoint conditions in bytecode form to GDBserver. GDBserver
3065 will only report the breakpoint trigger to GDB when its condition
3070 set mips compression
3071 show mips compression
3072 Select the compressed ISA encoding used in functions that have no symbol
3073 information available. The encoding can be set to either of:
3076 and is updated automatically from ELF file flags if available.
3078 set breakpoint condition-evaluation
3079 show breakpoint condition-evaluation
3080 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3081 GDBserver ("target"). Default option "auto" chooses the most efficient
3083 This option can improve debugger efficiency depending on the speed of the
3087 Disable auto-loading globally.
3090 Show auto-loading setting of all kinds of auto-loaded files.
3092 set auto-load gdb-scripts on|off
3093 show auto-load gdb-scripts
3094 Control auto-loading of GDB canned sequences of commands files.
3096 set auto-load python-scripts on|off
3097 show auto-load python-scripts
3098 Control auto-loading of Python script files.
3100 set auto-load local-gdbinit on|off
3101 show auto-load local-gdbinit
3102 Control loading of init file (.gdbinit) from current directory.
3104 set auto-load libthread-db on|off
3105 show auto-load libthread-db
3106 Control auto-loading of inferior specific thread debugging shared library.
3108 set auto-load scripts-directory <dir1>[:<dir2>...]
3109 show auto-load scripts-directory
3110 Set a list of directories from which to load auto-loaded scripts.
3111 Automatically loaded Python scripts and GDB scripts are located in one
3112 of the directories listed by this option.
3113 The delimiter (':' above) may differ according to the host platform.
3115 set auto-load safe-path <dir1>[:<dir2>...]
3116 show auto-load safe-path
3117 Set a list of directories from which it is safe to auto-load files.
3118 The delimiter (':' above) may differ according to the host platform.
3120 set debug auto-load on|off
3121 show debug auto-load
3122 Control display of debugging info for auto-loading the files above.
3124 set dprintf-style gdb|call|agent
3126 Control the way in which a dynamic printf is performed; "gdb"
3127 requests a GDB printf command, while "call" causes dprintf to call a
3128 function in the inferior. "agent" requests that the target agent
3129 (such as GDBserver) do the printing.
3131 set dprintf-function <expr>
3132 show dprintf-function
3133 set dprintf-channel <expr>
3134 show dprintf-channel
3135 Set the function and optional first argument to the call when using
3136 the "call" style of dynamic printf.
3138 set disconnected-dprintf on|off
3139 show disconnected-dprintf
3140 Control whether agent-style dynamic printfs continue to be in effect
3141 after GDB disconnects.
3143 * New configure options
3145 --with-auto-load-dir
3146 Configure default value for the 'set auto-load scripts-directory'
3147 setting above. It defaults to '$debugdir:$datadir/auto-load',
3148 $debugdir representing global debugging info directories (available
3149 via 'show debug-file-directory') and $datadir representing GDB's data
3150 directory (available via 'show data-directory').
3152 --with-auto-load-safe-path
3153 Configure default value for the 'set auto-load safe-path' setting
3154 above. It defaults to the --with-auto-load-dir setting.
3156 --without-auto-load-safe-path
3157 Set 'set auto-load safe-path' to '/', effectively disabling this
3160 * New remote packets
3162 z0/z1 conditional breakpoints extension
3164 The z0/z1 breakpoint insertion packets have been extended to carry
3165 a list of conditional expressions over to the remote stub depending on the
3166 condition evaluation mode. The use of this extension can be controlled
3167 via the "set remote conditional-breakpoints-packet" command.
3171 Specify the signals which the remote stub may pass to the debugged
3172 program without GDB involvement.
3174 * New command line options
3176 --init-command=FILE, -ix Like --command, -x but execute it
3177 before loading inferior.
3178 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3179 execute it before loading inferior.
3181 *** Changes in GDB 7.4
3183 * GDB now handles ambiguous linespecs more consistently; the existing
3184 FILE:LINE support has been expanded to other types of linespecs. A
3185 breakpoint will now be set on all matching locations in all
3186 inferiors, and locations will be added or removed according to
3189 * GDB now allows you to skip uninteresting functions and files when
3190 stepping with the "skip function" and "skip file" commands.
3192 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3193 and "show remote hardware-watchpoint-length-limit". These allows to
3194 set or show the maximum length limit (in bytes) of a remote
3195 target hardware watchpoint.
3197 This allows e.g. to use "unlimited" hardware watchpoints with the
3198 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3199 watchpoints are slower than real hardware watchpoints but are
3200 significantly faster than gdb software watchpoints.
3204 ** The register_pretty_printer function in module gdb.printing now takes
3205 an optional `replace' argument. If True, the new printer replaces any
3208 ** The "maint set python print-stack on|off" command has been
3209 deprecated and will be deleted in GDB 7.5.
3210 A new command: "set python print-stack none|full|message" has
3211 replaced it. Additionally, the default for "print-stack" is
3212 now "message", which just prints the error message without
3215 ** A prompt substitution hook (prompt_hook) is now available to the
3218 ** A new Python module, gdb.prompt has been added to the GDB Python
3219 modules library. This module provides functionality for
3220 escape sequences in prompts (used by set/show
3221 extended-prompt). These escape sequences are replaced by their
3222 corresponding value.
3224 ** Python commands and convenience-functions located in
3225 'data-directory'/python/gdb/command and
3226 'data-directory'/python/gdb/function are now automatically loaded
3229 ** Blocks now provide four new attributes. global_block and
3230 static_block will return the global and static blocks
3231 respectively. is_static and is_global are boolean attributes
3232 that indicate if the block is one of those two types.
3234 ** Symbols now provide the "type" attribute, the type of the symbol.
3236 ** The "gdb.breakpoint" function has been deprecated in favor of
3239 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3240 of a function. This class is based on the "finish" command
3241 available in the CLI.
3243 ** Type objects for struct and union types now allow access to
3244 the fields using standard Python dictionary (mapping) methods.
3245 For example, "some_type['myfield']" now works, as does
3246 "some_type.items()".
3248 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3251 ** A new function, "deep_items" has been added to the gdb.types
3252 module in the GDB Python modules library. This function returns
3253 an iterator over the fields of a struct or union type. Unlike
3254 the standard Python "iteritems" method, it will recursively traverse
3255 any anonymous fields.
3259 ** "*stopped" events can report several new "reason"s, such as
3262 ** Breakpoint changes are now notified using new async records, like
3263 "=breakpoint-modified".
3265 ** New command -ada-task-info.
3267 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3268 $sdir specifies the default system locations of shared libraries.
3269 $pdir specifies the directory where the libpthread used by the application
3272 GDB no longer looks in $sdir and $pdir after it has searched the directories
3273 mentioned in libthread-db-search-path. If you want to search those
3274 directories, they must be specified in libthread-db-search-path.
3275 The default value of libthread-db-search-path on GNU/Linux and Solaris
3276 systems is now "$sdir:$pdir".
3278 $pdir is not supported by gdbserver, it is currently ignored.
3279 $sdir is supported by gdbserver.
3281 * New configure option --with-iconv-bin.
3282 When using the internationalization support like the one in the GNU C
3283 library, GDB will invoke the "iconv" program to get a list of supported
3284 character sets. If this program lives in a non-standard location, one can
3285 use this option to specify where to find it.
3287 * When natively debugging programs on PowerPC BookE processors running
3288 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3289 watchpoints, which specify a mask in addition to an address to watch.
3290 The mask specifies that some bits of an address (the bits which are
3291 reset in the mask) should be ignored when matching the address accessed
3292 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3293 section in the user manual for more details.
3295 * The new option --once causes GDBserver to stop listening for connections once
3296 the first connection is made. The listening port used by GDBserver will
3297 become available after that.
3299 * New commands "info macros" and "alias" have been added.
3301 * New function parameters suffix @entry specifies value of function parameter
3302 at the time the function got called. Entry values are available only since
3308 "!" is now an alias of the "shell" command.
3309 Note that no space is needed between "!" and SHELL COMMAND.
3313 watch EXPRESSION mask MASK_VALUE
3314 The watch command now supports the mask argument which allows creation
3315 of masked watchpoints, if the current architecture supports this feature.
3317 info auto-load-scripts [REGEXP]
3318 This command was formerly named "maintenance print section-scripts".
3319 It is now generally useful and is no longer a maintenance-only command.
3321 info macro [-all] [--] MACRO
3322 The info macro command has new options `-all' and `--'. The first for
3323 printing all definitions of a macro. The second for explicitly specifying
3324 the end of arguments and the beginning of the macro name in case the macro
3325 name starts with a hyphen.
3327 collect[/s] EXPRESSIONS
3328 The tracepoint collect command now takes an optional modifier "/s"
3329 that directs it to dereference pointer-to-character types and
3330 collect the bytes of memory up to a zero byte. The behavior is
3331 similar to what you see when you use the regular print command on a
3332 string. An optional integer following the "/s" sets a bound on the
3333 number of bytes that will be collected.
3336 The trace start command now interprets any supplied arguments as a
3337 note to be recorded with the trace run, with an effect similar to
3338 setting the variable trace-notes.
3341 The trace stop command now interprets any arguments as a note to be
3342 mentioned along with the tstatus report that the trace was stopped
3343 with a command. The effect is similar to setting the variable
3346 * Tracepoints can now be enabled and disabled at any time after a trace
3347 experiment has been started using the standard "enable" and "disable"
3348 commands. It is now possible to start a trace experiment with no enabled
3349 tracepoints; GDB will display a warning, but will allow the experiment to
3350 begin, assuming that tracepoints will be enabled as needed while the trace
3353 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3354 locations with 4-byte instructions, when they were previously
3355 limited to locations with instructions of 5 bytes or longer.
3359 set debug dwarf2-read
3360 show debug dwarf2-read
3361 Turns on or off display of debugging messages related to reading
3362 DWARF debug info. The default is off.
3364 set debug symtab-create
3365 show debug symtab-create
3366 Turns on or off display of debugging messages related to symbol table
3367 creation. The default is off.
3370 show extended-prompt
3371 Set the GDB prompt, and allow escape sequences to be inserted to
3372 display miscellaneous information (see 'help set extended-prompt'
3373 for the list of sequences). This prompt (and any information
3374 accessed through the escape sequences) is updated every time the
3375 prompt is displayed.
3377 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3378 show print entry-values
3379 Set printing of frame argument values at function entry. In some cases
3380 GDB can determine the value of function argument which was passed by the
3381 function caller, even if the value was modified inside the called function.
3383 set debug entry-values
3384 show debug entry-values
3385 Control display of debugging info for determining frame argument values at
3386 function entry and virtual tail call frames.
3388 set basenames-may-differ
3389 show basenames-may-differ
3390 Set whether a source file may have multiple base names.
3391 (A "base name" is the name of a file with the directory part removed.
3392 Example: The base name of "/home/user/hello.c" is "hello.c".)
3393 If set, GDB will canonicalize file names (e.g., expand symlinks)
3394 before comparing them. Canonicalization is an expensive operation,
3395 but it allows the same file be known by more than one base name.
3396 If not set (the default), all source files are assumed to have just
3397 one base name, and gdb will do file name comparisons more efficiently.
3403 Set a user name and notes for the current and any future trace runs.
3404 This is useful for long-running and/or disconnected traces, to
3405 inform others (or yourself) as to who is running the trace, supply
3406 contact information, or otherwise explain what is going on.
3408 set trace-stop-notes
3409 show trace-stop-notes
3410 Set a note attached to the trace run, that is displayed when the
3411 trace has been stopped by a tstop command. This is useful for
3412 instance as an explanation, if you are stopping a trace run that was
3413 started by someone else.
3415 * New remote packets
3419 Dynamically enable a tracepoint in a started trace experiment.
3423 Dynamically disable a tracepoint in a started trace experiment.
3427 Set the user and notes of the trace run.
3431 Query the current status of a tracepoint.
3435 Query the minimum length of instruction at which a fast tracepoint may
3438 * Dcache size (number of lines) and line-size are now runtime-configurable
3439 via "set dcache line" and "set dcache line-size" commands.
3443 Texas Instruments TMS320C6x tic6x-*-*
3447 Renesas RL78 rl78-*-elf
3449 *** Changes in GDB 7.3.1
3451 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3453 *** Changes in GDB 7.3
3455 * GDB has a new command: "thread find [REGEXP]".
3456 It finds the thread id whose name, target id, or thread extra info
3457 matches the given regular expression.
3459 * The "catch syscall" command now works on mips*-linux* targets.
3461 * The -data-disassemble MI command now supports modes 2 and 3 for
3462 dumping the instruction opcodes.
3464 * New command line options
3466 -data-directory DIR Specify DIR as the "data-directory".
3467 This is mostly for testing purposes.
3469 * The "maint set python auto-load on|off" command has been renamed to
3470 "set auto-load-scripts on|off".
3472 * GDB has a new command: "set directories".
3473 It is like the "dir" command except that it replaces the
3474 source path list instead of augmenting it.
3476 * GDB now understands thread names.
3478 On GNU/Linux, "info threads" will display the thread name as set by
3479 prctl or pthread_setname_np.
3481 There is also a new command, "thread name", which can be used to
3482 assign a name internally for GDB to display.
3485 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3486 has been integrated into GDB.
3490 ** The function gdb.Write now accepts an optional keyword 'stream'.
3491 This keyword, when provided, will direct the output to either
3492 stdout, stderr, or GDB's logging output.
3494 ** Parameters can now be be sub-classed in Python, and in particular
3495 you may implement the get_set_doc and get_show_doc functions.
3496 This improves how Parameter set/show documentation is processed
3497 and allows for more dynamic content.
3499 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3500 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3501 have an is_valid method.
3503 ** Breakpoints can now be sub-classed in Python, and in particular
3504 you may implement a 'stop' function that is executed each time
3505 the inferior reaches that breakpoint.
3507 ** New function gdb.lookup_global_symbol looks up a global symbol.
3509 ** GDB values in Python are now callable if the value represents a
3510 function. For example, if 'some_value' represents a function that
3511 takes two integer parameters and returns a value, you can call
3512 that function like so:
3514 result = some_value (10,20)
3516 ** Module gdb.types has been added.
3517 It contains a collection of utilities for working with gdb.Types objects:
3518 get_basic_type, has_field, make_enum_dict.
3520 ** Module gdb.printing has been added.
3521 It contains utilities for writing and registering pretty-printers.
3522 New classes: PrettyPrinter, SubPrettyPrinter,
3523 RegexpCollectionPrettyPrinter.
3524 New function: register_pretty_printer.
3526 ** New commands "info pretty-printers", "enable pretty-printer" and
3527 "disable pretty-printer" have been added.
3529 ** gdb.parameter("directories") is now available.
3531 ** New function gdb.newest_frame returns the newest frame in the
3534 ** The gdb.InferiorThread class has a new "name" attribute. This
3535 holds the thread's name.
3537 ** Python Support for Inferior events.
3538 Python scripts can add observers to be notified of events
3539 occurring in the process being debugged.
3540 The following events are currently supported:
3541 - gdb.events.cont Continue event.
3542 - gdb.events.exited Inferior exited event.
3543 - gdb.events.stop Signal received, and Breakpoint hit events.
3547 ** GDB now puts template parameters in scope when debugging in an
3548 instantiation. For example, if you have:
3550 template<int X> int func (void) { return X; }
3552 then if you step into func<5>, "print X" will show "5". This
3553 feature requires proper debuginfo support from the compiler; it
3554 was added to GCC 4.5.
3556 ** The motion commands "next", "finish", "until", and "advance" now
3557 work better when exceptions are thrown. In particular, GDB will
3558 no longer lose control of the inferior; instead, the GDB will
3559 stop the inferior at the point at which the exception is caught.
3560 This functionality requires a change in the exception handling
3561 code that was introduced in GCC 4.5.
3563 * GDB now follows GCC's rules on accessing volatile objects when
3564 reading or writing target state during expression evaluation.
3565 One notable difference to prior behavior is that "print x = 0"
3566 no longer generates a read of x; the value of the assignment is
3567 now always taken directly from the value being assigned.
3569 * GDB now has some support for using labels in the program's source in
3570 linespecs. For instance, you can use "advance label" to continue
3571 execution to a label.
3573 * GDB now has support for reading and writing a new .gdb_index
3574 section. This section holds a fast index of DWARF debugging
3575 information and can be used to greatly speed up GDB startup and
3576 operation. See the documentation for `save gdb-index' for details.
3578 * The "watch" command now accepts an optional "-location" argument.
3579 When used, this causes GDB to watch the memory referred to by the
3580 expression. Such a watchpoint is never deleted due to it going out
3583 * GDB now supports thread debugging of core dumps on GNU/Linux.
3585 GDB now activates thread debugging using the libthread_db library
3586 when debugging GNU/Linux core dumps, similarly to when debugging
3587 live processes. As a result, when debugging a core dump file, GDB
3588 is now able to display pthread_t ids of threads. For example, "info
3589 threads" shows the same output as when debugging the process when it
3590 was live. In earlier releases, you'd see something like this:
3593 * 1 LWP 6780 main () at main.c:10
3595 While now you see this:
3598 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3600 It is also now possible to inspect TLS variables when debugging core
3603 When debugging a core dump generated on a machine other than the one
3604 used to run GDB, you may need to point GDB at the correct
3605 libthread_db library with the "set libthread-db-search-path"
3606 command. See the user manual for more details on this command.
3608 * When natively debugging programs on PowerPC BookE processors running
3609 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3610 which stop execution of the inferior whenever it executes an instruction
3611 at any address within the specified range. See the "PowerPC Embedded"
3612 section in the user manual for more details.
3614 * New features in the GDB remote stub, GDBserver
3616 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3617 and i686 LynxOS (version 5.x).
3619 ** GDBserver is now supported on Blackfin Linux.
3621 * New native configurations
3623 ia64 HP-UX ia64-*-hpux*
3627 Analog Devices, Inc. Blackfin Processor bfin-*
3629 * Ada task switching is now supported on sparc-elf targets when
3630 debugging a program using the Ravenscar Profile. For more information,
3631 see the "Tasking Support when using the Ravenscar Profile" section
3632 in the GDB user manual.
3634 * Guile support was removed.
3636 * New features in the GNU simulator
3638 ** The --map-info flag lists all known core mappings.
3640 ** CFI flashes may be simulated via the "cfi" device.
3642 *** Changes in GDB 7.2
3644 * Shared library support for remote targets by default
3646 When GDB is configured for a generic, non-OS specific target, like
3647 for example, --target=arm-eabi or one of the many *-*-elf targets,
3648 GDB now queries remote stubs for loaded shared libraries using the
3649 `qXfer:libraries:read' packet. Previously, shared library support
3650 was always disabled for such configurations.
3654 ** Argument Dependent Lookup (ADL)
3656 In C++ ADL lookup directs function search to the namespaces of its
3657 arguments even if the namespace has not been imported.
3667 Here the compiler will search for `foo' in the namespace of 'b'
3668 and find A::foo. GDB now supports this. This construct is commonly
3669 used in the Standard Template Library for operators.
3671 ** Improved User Defined Operator Support
3673 In addition to member operators, GDB now supports lookup of operators
3674 defined in a namespace and imported with a `using' directive, operators
3675 defined in the global scope, operators imported implicitly from an
3676 anonymous namespace, and the ADL operators mentioned in the previous
3678 GDB now also supports proper overload resolution for all the previously
3679 mentioned flavors of operators.
3681 ** static const class members
3683 Printing of static const class members that are initialized in the
3684 class definition has been fixed.
3686 * Windows Thread Information Block access.
3688 On Windows targets, GDB now supports displaying the Windows Thread
3689 Information Block (TIB) structure. This structure is visible either
3690 by using the new command `info w32 thread-information-block' or, by
3691 dereferencing the new convenience variable named `$_tlb', a
3692 thread-specific pointer to the TIB. This feature is also supported
3693 when remote debugging using GDBserver.
3695 * Static tracepoints
3697 Static tracepoints are calls in the user program into a tracing
3698 library. One such library is a port of the LTTng kernel tracer to
3699 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3700 When debugging with GDBserver, GDB now supports combining the GDB
3701 tracepoint machinery with such libraries. For example: the user can
3702 use GDB to probe a static tracepoint marker (a call from the user
3703 program into the tracing library) with the new "strace" command (see
3704 "New commands" below). This creates a "static tracepoint" in the
3705 breakpoint list, that can be manipulated with the same feature set
3706 as fast and regular tracepoints. E.g., collect registers, local and
3707 global variables, collect trace state variables, and define
3708 tracepoint conditions. In addition, the user can collect extra
3709 static tracepoint marker specific data, by collecting the new
3710 $_sdata internal variable. When analyzing the trace buffer, you can
3711 inspect $_sdata like any other variable available to GDB. For more
3712 information, see the "Tracepoints" chapter in GDB user manual. New
3713 remote packets have been defined to support static tracepoints, see
3714 the "New remote packets" section below.
3716 * Better reconstruction of tracepoints after disconnected tracing
3718 GDB will attempt to download the original source form of tracepoint
3719 definitions when starting a trace run, and then will upload these
3720 upon reconnection to the target, resulting in a more accurate
3721 reconstruction of the tracepoints that are in use on the target.
3725 You can now exercise direct control over the ways that GDB can
3726 affect your program. For instance, you can disallow the setting of
3727 breakpoints, so that the program can run continuously (assuming
3728 non-stop mode). In addition, the "observer" variable is available
3729 to switch all of the different controls; in observer mode, GDB
3730 cannot affect the target's behavior at all, which is useful for
3731 tasks like diagnosing live systems in the field.
3733 * The new convenience variable $_thread holds the number of the
3736 * New remote packets
3740 Return the address of the Windows Thread Information Block of a given thread.
3744 In response to several of the tracepoint packets, the target may now
3745 also respond with a number of intermediate `qRelocInsn' request
3746 packets before the final result packet, to have GDB handle
3747 relocating an instruction to execute at a different address. This
3748 is particularly useful for stubs that support fast tracepoints. GDB
3749 reports support for this feature in the qSupported packet.
3753 List static tracepoint markers in the target program.
3757 List static tracepoint markers at a given address in the target
3760 qXfer:statictrace:read
3762 Read the static trace data collected (by a `collect $_sdata'
3763 tracepoint action). The remote stub reports support for this packet
3764 to gdb's qSupported query.
3768 Send the current settings of GDB's permission flags.
3772 Send part of the source (textual) form of a tracepoint definition,
3773 which includes location, conditional, and action list.
3775 * The source command now accepts a -s option to force searching for the
3776 script in the source search path even if the script name specifies
3779 * New features in the GDB remote stub, GDBserver
3781 - GDBserver now support tracepoints (including fast tracepoints, and
3782 static tracepoints). The feature is currently supported by the
3783 i386-linux and amd64-linux builds. See the "Tracepoints support
3784 in gdbserver" section in the manual for more information.
3786 GDBserver JIT compiles the tracepoint's conditional agent
3787 expression bytecode into native code whenever possible for low
3788 overhead dynamic tracepoints conditionals. For such tracepoints,
3789 an expression that examines program state is evaluated when the
3790 tracepoint is reached, in order to determine whether to capture
3791 trace data. If the condition is simple and false, processing the
3792 tracepoint finishes very quickly and no data is gathered.
3794 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3795 for static tracepoints support.
3797 - GDBserver now supports x86_64 Windows 64-bit debugging.
3799 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3800 it understands register description.
3802 * The --batch flag now disables pagination and queries.
3804 * X86 general purpose registers
3806 GDB now supports reading/writing byte, word and double-word x86
3807 general purpose registers directly. This means you can use, say,
3808 $ah or $ax to refer, respectively, to the byte register AH and
3809 16-bit word register AX that are actually portions of the 32-bit
3810 register EAX or 64-bit register RAX.
3812 * The `commands' command now accepts a range of breakpoints to modify.
3813 A plain `commands' following a command that creates multiple
3814 breakpoints affects all the breakpoints set by that command. This
3815 applies to breakpoints set by `rbreak', and also applies when a
3816 single `break' command creates multiple breakpoints (e.g.,
3817 breakpoints on overloaded c++ functions).
3819 * The `rbreak' command now accepts a filename specification as part of
3820 its argument, limiting the functions selected by the regex to those
3821 in the specified file.
3823 * Support for remote debugging Windows and SymbianOS shared libraries
3824 from Unix hosts has been improved. Non Windows GDB builds now can
3825 understand target reported file names that follow MS-DOS based file
3826 system semantics, such as file names that include drive letters and
3827 use the backslash character as directory separator. This makes it
3828 possible to transparently use the "set sysroot" and "set
3829 solib-search-path" on Unix hosts to point as host copies of the
3830 target's shared libraries. See the new command "set
3831 target-file-system-kind" described below, and the "Commands to
3832 specify files" section in the user manual for more information.
3836 eval template, expressions...
3837 Convert the values of one or more expressions under the control
3838 of the string template to a command line, and call it.
3840 set target-file-system-kind unix|dos-based|auto
3841 show target-file-system-kind
3842 Set or show the assumed file system kind for target reported file
3845 save breakpoints <filename>
3846 Save all current breakpoint definitions to a file suitable for use
3847 in a later debugging session. To read the saved breakpoint
3848 definitions, use the `source' command.
3850 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3853 info static-tracepoint-markers
3854 Display information about static tracepoint markers in the target.
3856 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3857 Define a static tracepoint by probing a marker at the given
3858 function, line, address, or marker ID.
3862 Enable and disable observer mode.
3864 set may-write-registers on|off
3865 set may-write-memory on|off
3866 set may-insert-breakpoints on|off
3867 set may-insert-tracepoints on|off
3868 set may-insert-fast-tracepoints on|off
3869 set may-interrupt on|off
3870 Set individual permissions for GDB effects on the target. Note that
3871 some of these settings can have undesirable or surprising
3872 consequences, particularly when changed in the middle of a session.
3873 For instance, disabling the writing of memory can prevent
3874 breakpoints from being inserted, cause single-stepping to fail, or
3875 even crash your program, if you disable after breakpoints have been
3876 inserted. However, GDB should not crash.
3878 set record memory-query on|off
3879 show record memory-query
3880 Control whether to stop the inferior if memory changes caused
3881 by an instruction cannot be recorded.
3886 The disassemble command now supports "start,+length" form of two arguments.
3890 ** GDB now provides a new directory location, called the python directory,
3891 where Python scripts written for GDB can be installed. The location
3892 of that directory is <data-directory>/python, where <data-directory>
3893 is the GDB data directory. For more details, see section `Scripting
3894 GDB using Python' in the manual.
3896 ** The GDB Python API now has access to breakpoints, symbols, symbol
3897 tables, program spaces, inferiors, threads and frame's code blocks.
3898 Additionally, GDB Parameters can now be created from the API, and
3899 manipulated via set/show in the CLI.
3901 ** New functions gdb.target_charset, gdb.target_wide_charset,
3902 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3904 ** New exception gdb.GdbError.
3906 ** Pretty-printers are now also looked up in the current program space.
3908 ** Pretty-printers can now be individually enabled and disabled.
3910 ** GDB now looks for names of Python scripts to auto-load in a
3911 special section named `.debug_gdb_scripts', in addition to looking
3912 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3914 * Tracepoint actions were unified with breakpoint commands. In particular,
3915 there are no longer differences in "info break" output for breakpoints and
3916 tracepoints and the "commands" command can be used for both tracepoints and
3917 regular breakpoints.
3921 ARM Symbian arm*-*-symbianelf*
3923 * D language support.
3924 GDB now supports debugging programs written in the D programming
3927 * GDB now supports the extended ptrace interface for PowerPC which is
3928 available since Linux kernel version 2.6.34. This automatically enables
3929 any hardware breakpoints and additional hardware watchpoints available in
3930 the processor. The old ptrace interface exposes just one hardware
3931 watchpoint and no hardware breakpoints.
3933 * GDB is now able to use the Data Value Compare (DVC) register available on
3934 embedded PowerPC processors to implement in hardware simple watchpoint
3935 conditions of the form:
3937 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3939 This works in native GDB running on Linux kernels with the extended ptrace
3940 interface mentioned above.
3942 *** Changes in GDB 7.1
3946 ** Namespace Support
3948 GDB now supports importing of namespaces in C++. This enables the
3949 user to inspect variables from imported namespaces. Support for
3950 namepace aliasing has also been added. So, if a namespace is
3951 aliased in the current scope (e.g. namepace C=A; ) the user can
3952 print variables using the alias (e.g. (gdb) print C::x).
3956 All known bugs relating to the printing of virtual base class were
3957 fixed. It is now possible to call overloaded static methods using a
3962 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3963 and reinterpret_cast<> are now handled by the C++ expression parser.
3967 Xilinx MicroBlaze microblaze-*-*
3972 Xilinx MicroBlaze microblaze
3975 * Multi-program debugging.
3977 GDB now has support for multi-program (a.k.a. multi-executable or
3978 multi-exec) debugging. This allows for debugging multiple inferiors
3979 simultaneously each running a different program under the same GDB
3980 session. See "Debugging Multiple Inferiors and Programs" in the
3981 manual for more information. This implied some user visible changes
3982 in the multi-inferior support. For example, "info inferiors" now
3983 lists inferiors that are not running yet or that have exited
3984 already. See also "New commands" and "New options" below.
3986 * New tracing features
3988 GDB's tracepoint facility now includes several new features:
3990 ** Trace state variables
3992 GDB tracepoints now include support for trace state variables, which
3993 are variables managed by the target agent during a tracing
3994 experiment. They are useful for tracepoints that trigger each
3995 other, so for instance one tracepoint can count hits in a variable,
3996 and then a second tracepoint has a condition that is true when the
3997 count reaches a particular value. Trace state variables share the
3998 $-syntax of GDB convenience variables, and can appear in both
3999 tracepoint actions and condition expressions. Use the "tvariable"
4000 command to create, and "info tvariables" to view; see "Trace State
4001 Variables" in the manual for more detail.
4005 GDB now includes an option for defining fast tracepoints, which
4006 targets may implement more efficiently, such as by installing a jump
4007 into the target agent rather than a trap instruction. The resulting
4008 speedup can be by two orders of magnitude or more, although the
4009 tradeoff is that some program locations on some target architectures
4010 might not allow fast tracepoint installation, for instance if the
4011 instruction to be replaced is shorter than the jump. To request a
4012 fast tracepoint, use the "ftrace" command, with syntax identical to
4013 the regular trace command.
4015 ** Disconnected tracing
4017 It is now possible to detach GDB from the target while it is running
4018 a trace experiment, then reconnect later to see how the experiment
4019 is going. In addition, a new variable disconnected-tracing lets you
4020 tell the target agent whether to continue running a trace if the
4021 connection is lost unexpectedly.
4025 GDB now has the ability to save the trace buffer into a file, and
4026 then use that file as a target, similarly to you can do with
4027 corefiles. You can select trace frames, print data that was
4028 collected in them, and use tstatus to display the state of the
4029 tracing run at the moment that it was saved. To create a trace
4030 file, use "tsave <filename>", and to use it, do "target tfile
4033 ** Circular trace buffer
4035 You can ask the target agent to handle the trace buffer as a
4036 circular buffer, discarding the oldest trace frames to make room for
4037 newer ones, by setting circular-trace-buffer to on. This feature may
4038 not be available for all target agents.
4043 The disassemble command, when invoked with two arguments, now requires
4044 the arguments to be comma-separated.
4047 The info variables command now displays variable definitions. Files
4048 which only declare a variable are not shown.
4051 The source command is now capable of sourcing Python scripts.
4052 This feature is dependent on the debugger being build with Python
4055 Related to this enhancement is also the introduction of a new command
4056 "set script-extension" (see below).
4058 * New commands (for set/show, see "New options" below)
4060 record save [<FILENAME>]
4061 Save a file (in core file format) containing the process record
4062 execution log for replay debugging at a later time.
4064 record restore <FILENAME>
4065 Restore the process record execution log that was saved at an
4066 earlier time, for replay debugging.
4068 add-inferior [-copies <N>] [-exec <FILENAME>]
4071 clone-inferior [-copies <N>] [ID]
4072 Make a new inferior ready to execute the same program another
4073 inferior has loaded.
4078 maint info program-spaces
4079 List the program spaces loaded into GDB.
4081 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4082 show remote interrupt-sequence
4083 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4084 as the sequence to the remote target in order to interrupt the execution.
4085 Ctrl-C is a default. Some system prefers BREAK which is high level of
4086 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4087 Magic SysRq g. It is BREAK signal and character 'g'.
4089 set remote interrupt-on-connect [on | off]
4090 show remote interrupt-on-connect
4091 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4092 remote target when gdb connects to it. This is needed when you debug
4095 set remotebreak [on | off]
4097 Deprecated. Use "set/show remote interrupt-sequence" instead.
4099 tvariable $NAME [ = EXP ]
4100 Create or modify a trace state variable.
4103 List trace state variables and their values.
4105 delete tvariable $NAME ...
4106 Delete one or more trace state variables.
4109 Evaluate the given expressions without collecting anything into the
4110 trace buffer. (Valid in tracepoint actions only.)
4112 ftrace FN / FILE:LINE / *ADDR
4113 Define a fast tracepoint at the given function, line, or address.
4115 * New expression syntax
4117 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4118 GDB now parses 0b101010 identically with 42.
4122 set follow-exec-mode new|same
4123 show follow-exec-mode
4124 Control whether GDB reuses the same inferior across an exec call or
4125 creates a new one. This is useful to be able to restart the old
4126 executable after the inferior having done an exec call.
4128 set default-collect EXPR, ...
4129 show default-collect
4130 Define a list of expressions to be collected at each tracepoint.
4131 This is a useful way to ensure essential items are not overlooked,
4132 such as registers or a critical global variable.
4134 set disconnected-tracing
4135 show disconnected-tracing
4136 If set to 1, the target is instructed to continue tracing if it
4137 loses its connection to GDB. If 0, the target is to stop tracing
4140 set circular-trace-buffer
4141 show circular-trace-buffer
4142 If set to on, the target is instructed to use a circular trace buffer
4143 and discard the oldest trace frames instead of stopping the trace due
4144 to a full trace buffer. If set to off, the trace stops when the buffer
4145 fills up. Some targets may not support this.
4147 set script-extension off|soft|strict
4148 show script-extension
4149 If set to "off", the debugger does not perform any script language
4150 recognition, and all sourced files are assumed to be GDB scripts.
4151 If set to "soft" (the default), files are sourced according to
4152 filename extension, falling back to GDB scripts if the first
4154 If set to "strict", files are sourced according to filename extension.
4156 set ada trust-PAD-over-XVS on|off
4157 show ada trust-PAD-over-XVS
4158 If off, activate a workaround against a bug in the debugging information
4159 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4160 the GCC sources for more information about the GNAT encoding and
4161 PAD types in particular). It is always safe to set this option to
4162 off, but this introduces a slight performance penalty. The default
4165 * Python API Improvements
4167 ** GDB provides the new class gdb.LazyString. This is useful in
4168 some pretty-printing cases. The new method gdb.Value.lazy_string
4169 provides a simple way to create objects of this type.
4171 ** The fields returned by gdb.Type.fields now have an
4172 `is_base_class' attribute.
4174 ** The new method gdb.Type.range returns the range of an array type.
4176 ** The new method gdb.parse_and_eval can be used to parse and
4177 evaluate an expression.
4179 * New remote packets
4182 Define a trace state variable.
4185 Get the current value of a trace state variable.
4188 Set desired tracing behavior upon disconnection.
4191 Set the trace buffer to be linear or circular.
4194 Get data about the tracepoints currently in use.
4198 Process record now works correctly with hardware watchpoints.
4200 Multiple bug fixes have been made to the mips-irix port, making it
4201 much more reliable. In particular:
4202 - Debugging threaded applications is now possible again. Previously,
4203 GDB would hang while starting the program, or while waiting for
4204 the program to stop at a breakpoint.
4205 - Attaching to a running process no longer hangs.
4206 - An error occurring while loading a core file has been fixed.
4207 - Changing the value of the PC register now works again. This fixes
4208 problems observed when using the "jump" command, or when calling
4209 a function from GDB, or even when assigning a new value to $pc.
4210 - With the "finish" and "return" commands, the return value for functions
4211 returning a small array is now correctly printed.
4212 - It is now possible to break on shared library code which gets executed
4213 during a shared library init phase (code executed while executing
4214 their .init section). Previously, the breakpoint would have no effect.
4215 - GDB is now able to backtrace through the signal handler for
4216 non-threaded programs.
4218 PIE (Position Independent Executable) programs debugging is now supported.
4219 This includes debugging execution of PIC (Position Independent Code) shared
4220 libraries although for that, it should be possible to run such libraries as an
4223 *** Changes in GDB 7.0
4225 * GDB now has an interface for JIT compilation. Applications that
4226 dynamically generate code can create symbol files in memory and register
4227 them with GDB. For users, the feature should work transparently, and
4228 for JIT developers, the interface is documented in the GDB manual in the
4229 "JIT Compilation Interface" chapter.
4231 * Tracepoints may now be conditional. The syntax is as for
4232 breakpoints; either an "if" clause appended to the "trace" command,
4233 or the "condition" command is available. GDB sends the condition to
4234 the target for evaluation using the same bytecode format as is used
4235 for tracepoint actions.
4237 * The disassemble command now supports: an optional /r modifier, print the
4238 raw instructions in hex as well as in symbolic form, and an optional /m
4239 modifier to print mixed source+assembly.
4241 * Process record and replay
4243 In a architecture environment that supports ``process record and
4244 replay'', ``process record and replay'' target can record a log of
4245 the process execution, and replay it with both forward and reverse
4248 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4249 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4250 set execution-direction {forward|reverse}, for targets that support
4253 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4254 feature is available with a native GDB running on kernel version
4257 * GDB now has support for multi-byte and wide character sets on the
4258 target. Strings whose character type is wchar_t, char16_t, or
4259 char32_t are now correctly printed. GDB supports wide- and unicode-
4260 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4261 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4262 `printf'. This feature requires iconv to work properly; if your
4263 system does not have a working iconv, GDB can use GNU libiconv. See
4264 the installation instructions for more information.
4266 * GDB now supports automatic retrieval of shared library files from
4267 remote targets. To use this feature, specify a system root that begins
4268 with the `remote:' prefix, either via the `set sysroot' command or via
4269 the `--with-sysroot' configure-time option.
4271 * "info sharedlibrary" now takes an optional regex of libraries to show,
4272 and it now reports if a shared library has no debugging information.
4274 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4275 now complete on file names.
4277 * When completing in expressions, gdb will attempt to limit
4278 completions to allowable structure or union fields, where appropriate.
4279 For instance, consider:
4281 # struct example { int f1; double f2; };
4282 # struct example variable;
4285 If the user types TAB at the end of this command line, the available
4286 completions will be "f1" and "f2".
4288 * Inlined functions are now supported. They show up in backtraces, and
4289 the "step", "next", and "finish" commands handle them automatically.
4291 * GDB now supports the token-splicing (##) and stringification (#)
4292 operators when expanding macros. It also supports variable-arity
4295 * GDB now supports inspecting extra signal information, exported by
4296 the new $_siginfo convenience variable. The feature is currently
4297 implemented on linux ARM, i386 and amd64.
4299 * GDB can now display the VFP floating point registers and NEON vector
4300 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4301 can provide these registers (requires Linux 2.6.30 or later). Remote
4302 and simulator targets may also provide them.
4304 * New remote packets
4307 Search memory for a sequence of bytes.
4310 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4311 operation over reliable transport links. Use of this packet is
4312 controlled by the `set remote noack-packet' command.
4315 Kill the process with the specified process ID. Use this in preference
4316 to `k' when multiprocess protocol extensions are supported.
4319 Obtains additional operating system information
4323 Read or write additional signal information.
4325 * Removed remote protocol undocumented extension
4327 An undocumented extension to the remote protocol's `S' stop reply
4328 packet that permitted the stub to pass a process id was removed.
4329 Remote servers should use the `T' stop reply packet instead.
4331 * GDB now supports multiple function calling conventions according to the
4332 DWARF-2 DW_AT_calling_convention function attribute.
4334 * The SH target utilizes the aforementioned change to distinguish between gcc
4335 and Renesas calling convention. It also adds the new CLI commands
4336 `set/show sh calling-convention'.
4338 * GDB can now read compressed debug sections, as produced by GNU gold
4339 with the --compress-debug-sections=zlib flag.
4341 * 64-bit core files are now supported on AIX.
4343 * Thread switching is now supported on Tru64.
4345 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4346 which will be allocated using malloc later in program execution.
4348 * The qXfer:libraries:read remote protocol packet now allows passing a
4349 list of section offsets.
4351 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4352 conditions handling signals delivered during attach or thread creation
4353 have also been fixed.
4355 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4356 From the user's standpoint, all unqualified instances of True and False
4357 are treated as the standard definitions, regardless of context.
4359 * GDB now parses C++ symbol and type names more flexibly. For
4362 template<typename T> class C { };
4365 GDB will now correctly handle all of:
4367 ptype C<char const *>
4368 ptype C<char const*>
4369 ptype C<const char *>
4370 ptype C<const char*>
4372 * New features in the GDB remote stub, gdbserver
4374 - The "--wrapper" command-line argument tells gdbserver to use a
4375 wrapper program to launch programs for debugging.
4377 - On PowerPC and S/390 targets, it is now possible to use a single
4378 gdbserver executable to debug both 32-bit and 64-bit programs.
4379 (This requires gdbserver itself to be built as a 64-bit executable.)
4381 - gdbserver uses the new noack protocol mode for TCP connections to
4382 reduce communications latency, if also supported and enabled in GDB.
4384 - Support for the sparc64-linux-gnu target is now included in
4387 - The amd64-linux build of gdbserver now supports debugging both
4388 32-bit and 64-bit programs.
4390 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4391 now support hardware watchpoints, and will use them automatically
4396 GDB now has support for scripting using Python. Whether this is
4397 available is determined at configure time.
4399 New GDB commands can now be written in Python.
4401 * Ada tasking support
4403 Ada tasks can now be inspected in GDB. The following commands have
4407 Print the list of Ada tasks.
4409 Print detailed information about task number N.
4411 Print the task number of the current task.
4413 Switch the context of debugging to task number N.
4415 * Support for user-defined prefixed commands. The "define" command can
4416 add new commands to existing prefixes, e.g. "target".
4418 * Multi-inferior, multi-process debugging.
4420 GDB now has generalized support for multi-inferior debugging. See
4421 "Debugging Multiple Inferiors" in the manual for more information.
4422 Although availability still depends on target support, the command
4423 set is more uniform now. The GNU/Linux specific multi-forks support
4424 has been migrated to this new framework. This implied some user
4425 visible changes; see "New commands" and also "Removed commands"
4428 * Target descriptions can now describe the target OS ABI. See the
4429 "Target Description Format" section in the user manual for more
4432 * Target descriptions can now describe "compatible" architectures
4433 to indicate that the target can execute applications for a different
4434 architecture in addition to those for the main target architecture.
4435 See the "Target Description Format" section in the user manual for
4438 * Multi-architecture debugging.
4440 GDB now includes general supports for debugging applications on
4441 hybrid systems that use more than one single processor architecture
4442 at the same time. Each such hybrid architecture still requires
4443 specific support to be added. The only hybrid architecture supported
4444 in this version of GDB is the Cell Broadband Engine.
4446 * GDB now supports integrated debugging of Cell/B.E. applications that
4447 use both the PPU and SPU architectures. To enable support for hybrid
4448 Cell/B.E. debugging, you need to configure GDB to support both the
4449 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4450 --enable-targets configure option.
4452 * Non-stop mode debugging.
4454 For some targets, GDB now supports an optional mode of operation in
4455 which you can examine stopped threads while other threads continue
4456 to execute freely. This is referred to as non-stop mode, with the
4457 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4458 section in the user manual for more information.
4460 To be able to support remote non-stop debugging, a remote stub needs
4461 to implement the non-stop mode remote protocol extensions, as
4462 described in the "Remote Non-Stop" section of the user manual. The
4463 GDB remote stub, gdbserver, has been adjusted to support these
4464 extensions on linux targets.
4466 * New commands (for set/show, see "New options" below)
4468 catch syscall [NAME(S) | NUMBER(S)]
4469 Catch system calls. Arguments, which should be names of system
4470 calls or their numbers, mean catch only those syscalls. Without
4471 arguments, every syscall will be caught. When the inferior issues
4472 any of the specified syscalls, GDB will stop and announce the system
4473 call, both when it is called and when its call returns. This
4474 feature is currently available with a native GDB running on the
4475 Linux Kernel, under the following architectures: x86, x86_64,
4476 PowerPC and PowerPC64.
4478 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4480 Search memory for a sequence of bytes.
4482 maint set python print-stack
4483 maint show python print-stack
4484 Show a stack trace when an error is encountered in a Python script.
4487 Invoke CODE by passing it to the Python interpreter.
4492 These allow macros to be defined, undefined, and listed
4496 Show operating system information about processes.
4499 List the inferiors currently under GDB's control.
4502 Switch focus to inferior number NUM.
4505 Detach from inferior number NUM.
4508 Kill inferior number NUM.
4512 set spu stop-on-load
4513 show spu stop-on-load
4514 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4516 set spu auto-flush-cache
4517 show spu auto-flush-cache
4518 Control whether to automatically flush the software-managed cache
4519 during Cell/B.E. debugging.
4521 set sh calling-convention
4522 show sh calling-convention
4523 Control the calling convention used when calling SH target functions.
4526 show debug timestamp
4527 Control display of timestamps with GDB debugging output.
4529 set disassemble-next-line
4530 show disassemble-next-line
4531 Control display of disassembled source lines or instructions when
4534 set remote noack-packet
4535 show remote noack-packet
4536 Set/show the use of remote protocol QStartNoAckMode packet. See above
4537 under "New remote packets."
4539 set remote query-attached-packet
4540 show remote query-attached-packet
4541 Control use of remote protocol `qAttached' (query-attached) packet.
4543 set remote read-siginfo-object
4544 show remote read-siginfo-object
4545 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4548 set remote write-siginfo-object
4549 show remote write-siginfo-object
4550 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4553 set remote reverse-continue
4554 show remote reverse-continue
4555 Control use of remote protocol 'bc' (reverse-continue) packet.
4557 set remote reverse-step
4558 show remote reverse-step
4559 Control use of remote protocol 'bs' (reverse-step) packet.
4561 set displaced-stepping
4562 show displaced-stepping
4563 Control displaced stepping mode. Displaced stepping is a way to
4564 single-step over breakpoints without removing them from the debuggee.
4565 Also known as "out-of-line single-stepping".
4568 show debug displaced
4569 Control display of debugging info for displaced stepping.
4571 maint set internal-error
4572 maint show internal-error
4573 Control what GDB does when an internal error is detected.
4575 maint set internal-warning
4576 maint show internal-warning
4577 Control what GDB does when an internal warning is detected.
4582 Use a wrapper program to launch programs for debugging.
4584 set multiple-symbols (all|ask|cancel)
4585 show multiple-symbols
4586 The value of this variable can be changed to adjust the debugger behavior
4587 when an expression or a breakpoint location contains an ambiguous symbol
4588 name (an overloaded function name, for instance).
4590 set breakpoint always-inserted
4591 show breakpoint always-inserted
4592 Keep breakpoints always inserted in the target, as opposed to inserting
4593 them when resuming the target, and removing them when the target stops.
4594 This option can improve debugger performance on slow remote targets.
4596 set arm fallback-mode (arm|thumb|auto)
4597 show arm fallback-mode
4598 set arm force-mode (arm|thumb|auto)
4600 These commands control how ARM GDB determines whether instructions
4601 are ARM or Thumb. The default for both settings is auto, which uses
4602 the current CPSR value for instructions without symbols; previous
4603 versions of GDB behaved as if "set arm fallback-mode arm".
4605 set disable-randomization
4606 show disable-randomization
4607 Standalone programs run with the virtual address space randomization enabled
4608 by default on some platforms. This option keeps the addresses stable across
4609 multiple debugging sessions.
4613 Control whether other threads are stopped or not when some thread hits
4618 Requests that asynchronous execution is enabled in the target, if available.
4619 In this case, it's possible to resume target in the background, and interact
4620 with GDB while the target is running. "show target-async" displays the
4621 current state of asynchronous execution of the target.
4623 set target-wide-charset
4624 show target-wide-charset
4625 The target-wide-charset is the name of the character set that GDB
4626 uses when printing characters whose type is wchar_t.
4628 set tcp auto-retry (on|off)
4630 set tcp connect-timeout
4631 show tcp connect-timeout
4632 These commands allow GDB to retry failed TCP connections to a remote stub
4633 with a specified timeout period; this is useful if the stub is launched
4634 in parallel with GDB but may not be ready to accept connections immediately.
4636 set libthread-db-search-path
4637 show libthread-db-search-path
4638 Control list of directories which GDB will search for appropriate
4641 set schedule-multiple (on|off)
4642 show schedule-multiple
4643 Allow GDB to resume all threads of all processes or only threads of
4644 the current process.
4648 Use more aggressive caching for accesses to the stack. This improves
4649 performance of remote debugging (particularly backtraces) without
4650 affecting correctness.
4652 set interactive-mode (on|off|auto)
4653 show interactive-mode
4654 Control whether GDB runs in interactive mode (on) or not (off).
4655 When in interactive mode, GDB waits for the user to answer all
4656 queries. Otherwise, GDB does not wait and assumes the default
4657 answer. When set to auto (the default), GDB determines which
4658 mode to use based on the stdin settings.
4663 For program forks, this is replaced by the new more generic `info
4664 inferiors' command. To list checkpoints, you can still use the
4665 `info checkpoints' command, which was an alias for the `info forks'
4669 Replaced by the new `inferior' command. To switch between
4670 checkpoints, you can still use the `restart' command, which was an
4671 alias for the `fork' command.
4674 This is removed, since some targets don't have a notion of
4675 processes. To switch between processes, you can still use the
4676 `inferior' command using GDB's own inferior number.
4679 For program forks, this is replaced by the new more generic `kill
4680 inferior' command. To delete a checkpoint, you can still use the
4681 `delete checkpoint' command, which was an alias for the `delete
4685 For program forks, this is replaced by the new more generic `detach
4686 inferior' command. To detach a checkpoint, you can still use the
4687 `detach checkpoint' command, which was an alias for the `detach
4690 * New native configurations
4692 x86/x86_64 Darwin i[34567]86-*-darwin*
4694 x86_64 MinGW x86_64-*-mingw*
4698 Lattice Mico32 lm32-*
4699 x86 DICOS i[34567]86-*-dicos*
4700 x86_64 DICOS x86_64-*-dicos*
4703 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4704 (mingw32ce) debugging.
4710 These commands were actually not implemented on any target.
4712 *** Changes in GDB 6.8
4714 * New native configurations
4716 NetBSD/hppa hppa*-*netbsd*
4717 Xtensa GNU/Linux xtensa*-*-linux*
4721 NetBSD/hppa hppa*-*-netbsd*
4722 Xtensa GNU/Linux xtensa*-*-linux*
4724 * Change in command line behavior -- corefiles vs. process ids.
4726 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4727 attaching to process NUMBER fails, GDB no longer attempts to open a
4728 core file named NUMBER. Attaching to a program using the -c option
4729 is no longer supported. Instead, use the '-p' or '--pid' options.
4731 * GDB can now be built as a native debugger for debugging Windows x86
4732 (mingw32) Portable Executable (PE) programs.
4734 * Pending breakpoints no longer change their number when their address
4737 * GDB now supports breakpoints with multiple locations,
4738 including breakpoints on C++ constructors, inside C++ templates,
4739 and in inlined functions.
4741 * GDB's ability to debug optimized code has been improved. GDB more
4742 accurately identifies function bodies and lexical blocks that occupy
4743 more than one contiguous range of addresses.
4745 * Target descriptions can now describe registers for PowerPC.
4747 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4748 registers on PowerPC targets.
4750 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4751 targets even when the libthread_db library is not available.
4753 * The GDB remote stub, gdbserver, now supports the new file transfer
4754 commands (remote put, remote get, and remote delete).
4756 * The GDB remote stub, gdbserver, now supports run and attach in
4757 extended-remote mode.
4759 * hppa*64*-*-hpux11* target broken
4760 The debugger is unable to start a program and fails with the following
4761 error: "Error trying to get information about dynamic linker".
4762 The gdb-6.7 release is also affected.
4764 * GDB now supports the --enable-targets= configure option to allow
4765 building a single GDB executable that supports multiple remote
4766 target architectures.
4768 * GDB now supports debugging C and C++ programs which use the
4769 Decimal Floating Point extension. In addition, the PowerPC target
4770 now has a set of pseudo-registers to inspect decimal float values
4771 stored in two consecutive float registers.
4773 * The -break-insert MI command can optionally create pending
4776 * Improved support for debugging Ada
4777 Many improvements to the Ada language support have been made. These
4779 - Better support for Ada2005 interface types
4780 - Improved handling of arrays and slices in general
4781 - Better support for Taft-amendment types
4782 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4784 - Improved command completion in Ada
4787 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4792 set print frame-arguments (all|scalars|none)
4793 show print frame-arguments
4794 The value of this variable can be changed to control which argument
4795 values should be printed by the debugger when displaying a frame.
4800 Transfer files to and from a remote target, and delete remote files.
4807 Transfer files to and from a remote target, and delete remote files.
4809 * New remote packets
4816 Open, close, read, write, and delete files on the remote system.
4819 Attach to an existing process on the remote system, in extended-remote
4823 Run a new process on the remote system, in extended-remote mode.
4825 *** Changes in GDB 6.7
4827 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4828 bfd, libiberty and opcodes, as revealed by static analysis donated by
4829 Coverity, Inc. (http://scan.coverity.com).
4831 * When looking up multiply-defined global symbols, GDB will now prefer the
4832 symbol definition in the current shared library if it was built using the
4833 -Bsymbolic linker option.
4835 * When the Text User Interface (TUI) is not configured, GDB will now
4836 recognize the -tui command-line option and print a message that the TUI
4839 * The GDB remote stub, gdbserver, now has lower overhead for high
4840 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4842 * GDB for MIPS targets now autodetects whether a remote target provides
4843 32-bit or 64-bit register values.
4845 * Support for C++ member pointers has been improved.
4847 * GDB now understands XML target descriptions, which specify the
4848 target's overall architecture. GDB can read a description from
4849 a local file or over the remote serial protocol.
4851 * Vectors of single-byte data use a new integer type which is not
4852 automatically displayed as character or string data.
4854 * The /s format now works with the print command. It displays
4855 arrays of single-byte integers and pointers to single-byte integers
4858 * Target descriptions can now describe target-specific registers,
4859 for architectures which have implemented the support (currently
4860 only ARM, M68K, and MIPS).
4862 * GDB and the GDB remote stub, gdbserver, now support the XScale
4865 * The GDB remote stub, gdbserver, has been updated to support
4866 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4867 has been rewritten to use the standard GDB remote protocol.
4869 * GDB can now step into C++ functions which are called through thunks.
4871 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4873 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4874 layout. It also supports a TextSeg= and DataSeg= response when only
4875 segment base addresses (rather than offsets) are available.
4877 * The /i format now outputs any trailing branch delay slot instructions
4878 immediately following the last instruction within the count specified.
4880 * The GDB remote protocol "T" stop reply packet now supports a
4881 "library" response. Combined with the new "qXfer:libraries:read"
4882 packet, this response allows GDB to debug shared libraries on targets
4883 where the operating system manages the list of loaded libraries (e.g.
4884 Windows and SymbianOS).
4886 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4887 (DLLs) on Windows and Windows CE targets.
4889 * GDB now supports a faster verification that a .debug file matches its binary
4890 according to its build-id signature, if the signature is present.
4896 Enable or disable hardware flow control (RTS/CTS) on the serial port
4897 when debugging using remote targets.
4899 set mem inaccessible-by-default
4900 show mem inaccessible-by-default
4901 If the target supplies a memory map, for instance via the remote
4902 protocol's "qXfer:memory-map:read" packet, setting this variable
4903 prevents GDB from accessing memory outside the memory map. This
4904 is useful for targets with memory mapped registers or which react
4905 badly to accesses of unmapped address space.
4907 set breakpoint auto-hw
4908 show breakpoint auto-hw
4909 If the target supplies a memory map, for instance via the remote
4910 protocol's "qXfer:memory-map:read" packet, setting this variable
4911 lets GDB use hardware breakpoints automatically for memory regions
4912 where it can not use software breakpoints. This covers both the
4913 "break" command and internal breakpoints used for other commands
4914 including "next" and "finish".
4917 catch exception unhandled
4918 Stop the program execution when Ada exceptions are raised.
4921 Stop the program execution when an Ada assertion failed.
4925 Set an alternate system root for target files. This is a more
4926 general version of "set solib-absolute-prefix", which is now
4927 an alias to "set sysroot".
4930 Provide extended SPU facility status information. This set of
4931 commands is available only when debugging the Cell/B.E. SPU
4934 * New native configurations
4936 OpenBSD/sh sh*-*openbsd*
4939 unset tdesc filename
4941 Use the specified local file as an XML target description, and do
4942 not query the target for its built-in description.
4946 OpenBSD/sh sh*-*-openbsd*
4947 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4948 Toshiba Media Processor mep-elf
4950 * New remote packets
4953 Ignore the specified signals; pass them directly to the debugged program
4954 without stopping other threads or reporting them to GDB.
4956 qXfer:features:read:
4957 Read an XML target description from the target, which describes its
4962 Read or write contents of an spufs file on the target system. These
4963 packets are available only on the Cell/B.E. SPU architecture.
4965 qXfer:libraries:read:
4966 Report the loaded shared libraries. Combined with new "T" packet
4967 response, this packet allows GDB to debug shared libraries on
4968 targets where the operating system manages the list of loaded
4969 libraries (e.g. Windows and SymbianOS).
4973 Support for these obsolete configurations has been removed.
4981 i[34567]86-*-lynxos*
4982 i[34567]86-*-netware*
4983 i[34567]86-*-sco3.2v5*
4984 i[34567]86-*-sco3.2v4*
4986 i[34567]86-*-sysv4.2*
4989 i[34567]86-*-unixware2*
4990 i[34567]86-*-unixware*
4999 * Other removed features
5006 Various m68k-only ROM monitors.
5013 Various Renesas ROM monitors and debugging interfaces for SH and
5018 Support for a Macraigor serial interface to on-chip debugging.
5019 GDB does not directly support the newer parallel or USB
5024 A debug information format. The predecessor to DWARF 2 and
5025 DWARF 3, which are still supported.
5027 Support for the HP aCC compiler on HP-UX/PA-RISC
5029 SOM-encapsulated symbolic debugging information, automatic
5030 invocation of pxdb, and the aCC custom C++ ABI. This does not
5031 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5032 with aCC can still be debugged on an assembly level.
5034 MIPS ".pdr" sections
5036 A MIPS-specific format used to describe stack frame layout
5037 in debugging information.
5041 GDB could work with an older version of Guile to debug
5042 the interpreter and Scheme programs running in it.
5044 set mips stack-arg-size
5045 set mips saved-gpreg-size
5047 Use "set mips abi" to control parameter passing for MIPS.
5049 *** Changes in GDB 6.6
5054 Cell Broadband Engine SPU spu-elf
5056 * GDB can now be configured as a cross-debugger targeting native Windows
5057 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5058 running on a Windows system over TCP/IP to debug Windows programs.
5060 * The GDB remote stub, gdbserver, has been updated to support Windows and
5061 Cygwin debugging. Both single-threaded and multi-threaded programs are
5064 * The "set trust-readonly-sections" command works again. This command was
5065 broken in GDB 6.3, 6.4, and 6.5.
5067 * The "load" command now supports writing to flash memory, if the remote
5068 stub provides the required support.
5070 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5071 longer requires symbolic debug information (e.g. DWARF-2).
5076 unset substitute-path
5077 show substitute-path
5078 Manage a list of substitution rules that GDB uses to rewrite the name
5079 of the directories where the sources are located. This can be useful
5080 for instance when the sources were moved to a different location
5081 between compilation and debugging.
5085 Print each CLI command as it is executed. Each command is prefixed with
5086 a number of `+' symbols representing the nesting depth.
5087 The source command now has a `-v' option to enable the same feature.
5091 The ARM Demon monitor support (RDP protocol, "target rdp").
5093 Kernel Object Display, an embedded debugging feature which only worked with
5094 an obsolete version of Cisco IOS.
5096 The 'set download-write-size' and 'show download-write-size' commands.
5098 * New remote packets
5101 Tell a stub about GDB client features, and request remote target features.
5102 The first feature implemented is PacketSize, which allows the target to
5103 specify the size of packets it can handle - to minimize the number of
5104 packets required and improve performance when connected to a remote
5108 Fetch an OS auxilliary vector from the remote stub. This packet is a
5109 more efficient replacement for qPart:auxv:read.
5111 qXfer:memory-map:read:
5112 Fetch a memory map from the remote stub, including information about
5113 RAM, ROM, and flash memory devices.
5118 Erase and program a flash memory device.
5120 * Removed remote packets
5123 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5124 used it, and only gdbserver implemented it.
5126 *** Changes in GDB 6.5
5130 Renesas M32C/M16C m32c-elf
5132 Morpho Technologies ms1 ms1-elf
5136 init-if-undefined Initialize a convenience variable, but
5137 only if it doesn't already have a value.
5139 The following commands are presently only implemented for native GNU/Linux:
5141 checkpoint Save a snapshot of the program state.
5143 restart <n> Return the program state to a
5144 previously saved state.
5146 info checkpoints List currently saved checkpoints.
5148 delete-checkpoint <n> Delete a previously saved checkpoint.
5150 set|show detach-on-fork Tell gdb whether to detach from a newly
5151 forked process, or to keep debugging it.
5153 info forks List forks of the user program that
5154 are available to be debugged.
5156 fork <n> Switch to debugging one of several
5157 forks of the user program that are
5158 available to be debugged.
5160 delete-fork <n> Delete a fork from the list of forks
5161 that are available to be debugged (and
5162 kill the forked process).
5164 detach-fork <n> Delete a fork from the list of forks
5165 that are available to be debugged (and
5166 allow the process to continue).
5170 Morpho Technologies ms2 ms1-elf
5172 * Improved Windows host support
5174 GDB now builds as a cross debugger hosted on i686-mingw32, including
5175 native console support, and remote communications using either
5176 network sockets or serial ports.
5178 * Improved Modula-2 language support
5180 GDB can now print most types in the Modula-2 syntax. This includes:
5181 basic types, set types, record types, enumerated types, range types,
5182 pointer types and ARRAY types. Procedure var parameters are correctly
5183 printed and hexadecimal addresses and character constants are also
5184 written in the Modula-2 syntax. Best results can be obtained by using
5185 GNU Modula-2 together with the -gdwarf-2 command line option.
5189 The ARM rdi-share module.
5191 The Netware NLM debug server.
5193 *** Changes in GDB 6.4
5195 * New native configurations
5197 OpenBSD/arm arm*-*-openbsd*
5198 OpenBSD/mips64 mips64-*-openbsd*
5202 Morpho Technologies ms1 ms1-elf
5204 * New command line options
5206 --batch-silent As for --batch, but totally silent.
5207 --return-child-result The debugger will exist with the same value
5208 the child (debugged) program exited with.
5209 --eval-command COMMAND, -ex COMMAND
5210 Execute a single GDB CLI command. This may be
5211 specified multiple times and in conjunction
5212 with the --command (-x) option.
5214 * Deprecated commands removed
5216 The following commands, that were deprecated in 2000, have been
5220 set|show arm disassembly-flavor set|show arm disassembler
5221 othernames set arm disassembler
5222 set|show remotedebug set|show debug remote
5223 set|show archdebug set|show debug arch
5224 set|show eventdebug set|show debug event
5227 * New BSD user-level threads support
5229 It is now possible to debug programs using the user-level threads
5230 library on OpenBSD and FreeBSD. Currently supported (target)
5233 FreeBSD/amd64 x86_64-*-freebsd*
5234 FreeBSD/i386 i386-*-freebsd*
5235 OpenBSD/i386 i386-*-openbsd*
5237 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5238 are not yet supported.
5240 * New support for Matsushita MN10300 w/sim added
5241 (Work in progress). mn10300-elf.
5243 * REMOVED configurations and files
5245 VxWorks and the XDR protocol *-*-vxworks
5246 Motorola MCORE mcore-*-*
5247 National Semiconductor NS32000 ns32k-*-*
5249 * New "set print array-indexes" command
5251 After turning this setting "on", GDB prints the index of each element
5252 when displaying arrays. The default is "off" to preserve the previous
5255 * VAX floating point support
5257 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5259 * User-defined command support
5261 In addition to using $arg0..$arg9 for argument passing, it is now possible
5262 to use $argc to determine now many arguments have been passed. See the
5263 section on user-defined commands in the user manual for more information.
5265 *** Changes in GDB 6.3:
5267 * New command line option
5269 GDB now accepts -l followed by a number to set the timeout for remote
5272 * GDB works with GCC -feliminate-dwarf2-dups
5274 GDB now supports a more compact representation of DWARF-2 debug
5275 information using DW_FORM_ref_addr references. These are produced
5276 by GCC with the option -feliminate-dwarf2-dups and also by some
5277 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5278 to use -feliminate-dwarf2-dups.
5280 * Internationalization
5282 When supported by the host system, GDB will be built with
5283 internationalization (libintl). The task of marking up the sources is
5284 continued, we're looking forward to our first translation.
5288 Initial support for debugging programs compiled with the GNAT
5289 implementation of the Ada programming language has been integrated
5290 into GDB. In this release, support is limited to expression evaluation.
5292 * New native configurations
5294 GNU/Linux/m32r m32r-*-linux-gnu
5298 GDB's remote protocol now includes support for the 'p' packet. This
5299 packet is used to fetch individual registers from a remote inferior.
5301 * END-OF-LIFE registers[] compatibility module
5303 GDB's internal register infrastructure has been completely rewritten.
5304 The new infrastructure making possible the implementation of key new
5305 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5308 GDB 6.3 will be the last release to include the registers[]
5309 compatibility module that allowed out-of-date configurations to
5310 continue to work. This change directly impacts the following
5320 powerpc bdm protocol
5322 Unless there is activity to revive these configurations, they will be
5323 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5325 * OBSOLETE configurations and files
5327 Configurations that have been declared obsolete in this release have
5328 been commented out. Unless there is activity to revive these
5329 configurations, the next release of GDB will have their sources
5330 permanently REMOVED.
5339 *** Changes in GDB 6.2.1:
5341 * MIPS `break main; run' gave an heuristic-fence-post warning
5343 When attempting to run even a simple program, a warning about
5344 heuristic-fence-post being hit would be reported. This problem has
5347 * MIPS IRIX 'long double' crashed GDB
5349 When examining a long double variable, GDB would get a segmentation
5350 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5351 IRIX long double values).
5355 A bug in the VAX stack code was causing problems with the "next"
5356 command. This problem has been fixed.
5358 *** Changes in GDB 6.2:
5360 * Fix for ``many threads''
5362 On GNU/Linux systems that use the NPTL threads library, a program
5363 rapidly creating and deleting threads would confuse GDB leading to the
5366 ptrace: No such process.
5367 thread_db_get_info: cannot get thread info: generic error
5369 This problem has been fixed.
5371 * "-async" and "-noasync" options removed.
5373 Support for the broken "-noasync" option has been removed (it caused
5376 * New ``start'' command.
5378 This command runs the program until the beginning of the main procedure.
5380 * New BSD Kernel Data Access Library (libkvm) interface
5382 Using ``target kvm'' it is now possible to debug kernel core dumps and
5383 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5384 platforms. Currently supported (native-only) configurations are:
5386 FreeBSD/amd64 x86_64-*-freebsd*
5387 FreeBSD/i386 i?86-*-freebsd*
5388 NetBSD/i386 i?86-*-netbsd*
5389 NetBSD/m68k m68*-*-netbsd*
5390 NetBSD/sparc sparc-*-netbsd*
5391 OpenBSD/amd64 x86_64-*-openbsd*
5392 OpenBSD/i386 i?86-*-openbsd*
5393 OpenBSD/m68k m68*-openbsd*
5394 OpenBSD/sparc sparc-*-openbsd*
5396 * Signal trampoline code overhauled
5398 Many generic problems with GDB's signal handling code have been fixed.
5399 These include: backtraces through non-contiguous stacks; recognition
5400 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5401 call; backtrace through a signal trampoline; step into and out of
5402 signal handlers; and single-stepping in the signal trampoline.
5404 Please note that kernel bugs are a limiting factor here. These
5405 features have been shown to work on an s390 GNU/Linux system that
5406 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5408 * Cygwin support for DWARF 2 added.
5410 * New native configurations
5412 GNU/Linux/hppa hppa*-*-linux*
5413 OpenBSD/hppa hppa*-*-openbsd*
5414 OpenBSD/m68k m68*-*-openbsd*
5415 OpenBSD/m88k m88*-*-openbsd*
5416 OpenBSD/powerpc powerpc-*-openbsd*
5417 NetBSD/vax vax-*-netbsd*
5418 OpenBSD/vax vax-*-openbsd*
5420 * END-OF-LIFE frame compatibility module
5422 GDB's internal frame infrastructure has been completely rewritten.
5423 The new infrastructure making it possible to support key new features
5424 including DWARF 2 Call Frame Information. To aid in the task of
5425 migrating old configurations to this new infrastructure, a
5426 compatibility module, that allowed old configurations to continue to
5427 work, was also included.
5429 GDB 6.2 will be the last release to include this frame compatibility
5430 module. This change directly impacts the following configurations:
5440 Unless there is activity to revive these configurations, they will be
5441 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5443 * REMOVED configurations and files
5445 Sun 3, running SunOS 3 m68*-*-sunos3*
5446 Sun 3, running SunOS 4 m68*-*-sunos4*
5447 Sun 2, running SunOS 3 m68000-*-sunos3*
5448 Sun 2, running SunOS 4 m68000-*-sunos4*
5449 Motorola 680x0 running LynxOS m68*-*-lynxos*
5450 AT&T 3b1/Unix pc m68*-att-*
5451 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5452 decstation mips-dec-* mips-little-*
5453 riscos mips-*-riscos* mips-*-sysv*
5454 sonymips mips-sony-*
5455 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5457 *** Changes in GDB 6.1.1:
5459 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5461 The TUI (Text-mode User Interface) is now built as part of a default
5462 GDB configuration. It is enabled by either selecting the TUI with the
5463 command line option "-i=tui" or by running the separate "gdbtui"
5464 program. For more information on the TUI, see the manual "Debugging
5467 * Pending breakpoint support (also included in GDB 6.1)
5469 Support has been added to allow you to specify breakpoints in shared
5470 libraries that have not yet been loaded. If a breakpoint location
5471 cannot be found, and the "breakpoint pending" option is set to auto,
5472 GDB queries you if you wish to make the breakpoint pending on a future
5473 shared-library load. If and when GDB resolves the breakpoint symbol,
5474 the pending breakpoint is removed as one or more regular breakpoints
5477 Pending breakpoints are very useful for GCJ Java debugging.
5479 * Fixed ISO-C build problems
5481 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5482 non ISO-C code that stopped them being built using a more strict ISO-C
5483 compiler (e.g., IBM's C compiler).
5485 * Fixed build problem on IRIX 5
5487 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5488 wasn't able to compile compile on an IRIX 5 system.
5490 * Added execute permission to gdb/gdbserver/configure
5492 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5493 permission. This bug would cause configure to fail on a number of
5494 systems (Solaris, IRIX). Ref: server/519.
5496 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5498 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5499 has been updated to use constant array sizes.
5501 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5503 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5504 its generated DWARF Call Frame Info. This encoding was causing GDB to
5505 panic, that panic has been fixed. Ref: gdb/1628.
5507 * Fixed a problem when examining parameters in shared library code.
5509 When examining parameters in optimized shared library code generated
5510 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5511 not available''. GDB now correctly displays the variable's value.
5513 *** Changes in GDB 6.1:
5515 * Removed --with-mmalloc
5517 Support for the mmalloc memory manager has been removed, as it
5518 conflicted with the internal gdb byte cache.
5520 * Changes in AMD64 configurations
5522 The AMD64 target now includes the %cs and %ss registers. As a result
5523 the AMD64 remote protocol has changed; this affects the floating-point
5524 and SSE registers. If you rely on those registers for your debugging,
5525 you should upgrade gdbserver on the remote side.
5527 * Revised SPARC target
5529 The SPARC target has been completely revised, incorporating the
5530 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5531 support for LynxOS and SunOS 4 has been dropped. Calling functions
5532 from within GDB on operating systems with a non-executable stack
5533 (Solaris, OpenBSD) now works.
5537 GDB has a new C++ demangler which does a better job on the mangled
5538 names generated by current versions of g++. It also runs faster, so
5539 with this and other changes gdb should now start faster on large C++
5542 * DWARF 2 Location Expressions
5544 GDB support for location expressions has been extended to support function
5545 arguments and frame bases. Older versions of GDB could crash when they
5548 * C++ nested types and namespaces
5550 GDB's support for nested types and namespaces in C++ has been
5551 improved, especially if you use the DWARF 2 debugging format. (This
5552 is the default for recent versions of GCC on most platforms.)
5553 Specifically, if you have a class "Inner" defined within a class or
5554 namespace "Outer", then GDB realizes that the class's name is
5555 "Outer::Inner", not simply "Inner". This should greatly reduce the
5556 frequency of complaints about not finding RTTI symbols. In addition,
5557 if you are stopped at inside of a function defined within a namespace,
5558 GDB modifies its name lookup accordingly.
5560 * New native configurations
5562 NetBSD/amd64 x86_64-*-netbsd*
5563 OpenBSD/amd64 x86_64-*-openbsd*
5564 OpenBSD/alpha alpha*-*-openbsd*
5565 OpenBSD/sparc sparc-*-openbsd*
5566 OpenBSD/sparc64 sparc64-*-openbsd*
5568 * New debugging protocols
5570 M32R with SDI protocol m32r-*-elf*
5572 * "set prompt-escape-char" command deleted.
5574 The command "set prompt-escape-char" has been deleted. This command,
5575 and its very obscure effect on GDB's prompt, was never documented,
5576 tested, nor mentioned in the NEWS file.
5578 * OBSOLETE configurations and files
5580 Configurations that have been declared obsolete in this release have
5581 been commented out. Unless there is activity to revive these
5582 configurations, the next release of GDB will have their sources
5583 permanently REMOVED.
5585 Sun 3, running SunOS 3 m68*-*-sunos3*
5586 Sun 3, running SunOS 4 m68*-*-sunos4*
5587 Sun 2, running SunOS 3 m68000-*-sunos3*
5588 Sun 2, running SunOS 4 m68000-*-sunos4*
5589 Motorola 680x0 running LynxOS m68*-*-lynxos*
5590 AT&T 3b1/Unix pc m68*-att-*
5591 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5592 decstation mips-dec-* mips-little-*
5593 riscos mips-*-riscos* mips-*-sysv*
5594 sonymips mips-sony-*
5595 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5597 * REMOVED configurations and files
5599 SGI Irix-4.x mips-sgi-irix4 or iris4
5600 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5601 Z8000 simulator z8k-zilog-none or z8ksim
5602 Matsushita MN10200 w/simulator mn10200-*-*
5603 H8/500 simulator h8500-hitachi-hms or h8500hms
5604 HP/PA running BSD hppa*-*-bsd*
5605 HP/PA running OSF/1 hppa*-*-osf*
5606 HP/PA Pro target hppa*-*-pro*
5607 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5608 386BSD i[3456]86-*-bsd*
5609 Sequent family i[3456]86-sequent-sysv4*
5610 i[3456]86-sequent-sysv*
5611 i[3456]86-sequent-bsd*
5612 SPARC running LynxOS sparc-*-lynxos*
5613 SPARC running SunOS 4 sparc-*-sunos4*
5614 Tsqware Sparclet sparclet-*-*
5615 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5617 *** Changes in GDB 6.0:
5621 Support for debugging the Objective-C programming language has been
5622 integrated into GDB.
5624 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5626 DWARF 2's Call Frame Information makes available compiler generated
5627 information that more exactly describes the program's run-time stack.
5628 By using this information, GDB is able to provide more robust stack
5631 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5632 have been updated to use a new backtrace mechanism which includes
5633 DWARF 2 CFI support.
5637 GDB's remote protocol has been extended to include support for hosted
5638 file I/O (where the remote target uses GDB's file system). See GDB's
5639 remote protocol documentation for details.
5641 * All targets using the new architecture framework.
5643 All of GDB's targets have been updated to use the new internal
5644 architecture framework. The way is now open for future GDB releases
5645 to include cross-architecture native debugging support (i386 on amd64,
5648 * GNU/Linux's Thread Local Storage (TLS)
5650 GDB now includes support for for the GNU/Linux implementation of
5651 per-thread variables.
5653 * GNU/Linux's Native POSIX Thread Library (NPTL)
5655 GDB's thread code has been updated to work with either the new
5656 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5658 * Separate debug info.
5660 GDB, in conjunction with BINUTILS, now supports a mechanism for
5661 automatically loading debug information from a separate file. Instead
5662 of shipping full debug and non-debug versions of system libraries,
5663 system integrators can now instead ship just the stripped libraries
5664 and optional debug files.
5666 * DWARF 2 Location Expressions
5668 DWARF 2 Location Expressions allow the compiler to more completely
5669 describe the location of variables (even in optimized code) to the
5672 GDB now includes preliminary support for location expressions (support
5673 for DW_OP_piece is still missing).
5677 A number of long standing bugs that caused GDB to die while starting a
5678 Java application have been fixed. GDB's Java support is now
5679 considered "useable".
5681 * GNU/Linux support for fork, vfork, and exec.
5683 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5684 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5687 * GDB supports logging output to a file
5689 There are two new commands, "set logging" and "show logging", which can be
5690 used to capture GDB's output to a file.
5692 * The meaning of "detach" has changed for gdbserver
5694 The "detach" command will now resume the application, as documented. To
5695 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5698 * d10v, m68hc11 `regs' command deprecated
5700 The `info registers' command has been updated so that it displays the
5701 registers using a format identical to the old `regs' command.
5705 A new command, "maint set profile on/off", has been added. This command can
5706 be used to enable or disable profiling while running GDB, to profile a
5707 session or a set of commands. In addition there is a new configure switch,
5708 "--enable-profiling", which will cause GDB to be compiled with profiling
5709 data, for more informative profiling results.
5711 * Default MI syntax changed to "mi2".
5713 The default MI (machine interface) syntax, enabled by the command line
5714 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5715 "mi1", can be enabled by specifying the option "-i=mi1".
5717 Support for the original "mi0" syntax (included in GDB 5.0) has been
5720 Fix for gdb/192: removed extraneous space when displaying frame level.
5721 Fix for gdb/672: update changelist is now output in mi list format.
5722 Fix for gdb/702: a -var-assign that updates the value now shows up
5723 in a subsequent -var-update.
5725 * New native configurations.
5727 FreeBSD/amd64 x86_64-*-freebsd*
5729 * Multi-arched targets.
5731 HP/PA HPUX11 hppa*-*-hpux*
5732 Renesas M32R/D w/simulator m32r-*-elf*
5734 * OBSOLETE configurations and files
5736 Configurations that have been declared obsolete in this release have
5737 been commented out. Unless there is activity to revive these
5738 configurations, the next release of GDB will have their sources
5739 permanently REMOVED.
5741 Z8000 simulator z8k-zilog-none or z8ksim
5742 Matsushita MN10200 w/simulator mn10200-*-*
5743 H8/500 simulator h8500-hitachi-hms or h8500hms
5744 HP/PA running BSD hppa*-*-bsd*
5745 HP/PA running OSF/1 hppa*-*-osf*
5746 HP/PA Pro target hppa*-*-pro*
5747 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5748 Sequent family i[3456]86-sequent-sysv4*
5749 i[3456]86-sequent-sysv*
5750 i[3456]86-sequent-bsd*
5751 Tsqware Sparclet sparclet-*-*
5752 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5754 * REMOVED configurations and files
5757 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5758 IBM AIX PS/2 i[3456]86-*-aix
5759 i386 running Mach 3.0 i[3456]86-*-mach3*
5760 i386 running Mach i[3456]86-*-mach*
5761 i386 running OSF/1 i[3456]86-*osf1mk*
5762 HP/Apollo 68k Family m68*-apollo*-sysv*,
5764 m68*-hp-bsd*, m68*-hp-hpux*
5765 Argonaut Risc Chip (ARC) arc-*-*
5766 Mitsubishi D30V d30v-*-*
5767 Fujitsu FR30 fr30-*-elf*
5768 OS/9000 i[34]86-*-os9k
5769 I960 with MON960 i960-*-coff
5771 * MIPS $fp behavior changed
5773 The convenience variable $fp, for the MIPS, now consistently returns
5774 the address of the current frame's base. Previously, depending on the
5775 context, $fp could refer to either $sp or the current frame's base
5776 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5777 The GNU Source-Level Debugger''.
5779 *** Changes in GDB 5.3:
5781 * GNU/Linux shared library multi-threaded performance improved.
5783 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5784 `/proc', in preference to `ptrace' for memory reads. This may result
5785 in an improvement in the start-up time of multi-threaded, shared
5786 library applications when run under GDB. One GDB user writes: ``loads
5787 shared libs like mad''.
5789 * ``gdbserver'' now supports multi-threaded applications on some targets
5791 Support for debugging multi-threaded applications which use
5792 the GNU/Linux LinuxThreads package has been added for
5793 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5794 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5796 * GDB now supports C/C++ preprocessor macros.
5798 GDB now expands preprocessor macro invocations in C/C++ expressions,
5799 and provides various commands for showing macro definitions and how
5802 The new command `macro expand EXPRESSION' expands any macro
5803 invocations in expression, and shows the result.
5805 The new command `show macro MACRO-NAME' shows the definition of the
5806 macro named MACRO-NAME, and where it was defined.
5808 Most compilers don't include information about macros in the debugging
5809 information by default. In GCC 3.1, for example, you need to compile
5810 your program with the options `-gdwarf-2 -g3'. If the macro
5811 information is present in the executable, GDB will read it.
5813 * Multi-arched targets.
5815 DEC Alpha (partial) alpha*-*-*
5816 DEC VAX (partial) vax-*-*
5818 National Semiconductor NS32000 (partial) ns32k-*-*
5819 Motorola 68000 (partial) m68k-*-*
5820 Motorola MCORE mcore-*-*
5824 Fujitsu FRV architecture added by Red Hat frv*-*-*
5827 * New native configurations
5829 Alpha NetBSD alpha*-*-netbsd*
5830 SH NetBSD sh*-*-netbsdelf*
5831 MIPS NetBSD mips*-*-netbsd*
5832 UltraSPARC NetBSD sparc64-*-netbsd*
5834 * OBSOLETE configurations and files
5836 Configurations that have been declared obsolete in this release have
5837 been commented out. Unless there is activity to revive these
5838 configurations, the next release of GDB will have their sources
5839 permanently REMOVED.
5841 Mitsubishi D30V d30v-*-*
5842 OS/9000 i[34]86-*-os9k
5843 IBM AIX PS/2 i[3456]86-*-aix
5844 Fujitsu FR30 fr30-*-elf*
5845 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5846 Argonaut Risc Chip (ARC) arc-*-*
5847 i386 running Mach 3.0 i[3456]86-*-mach3*
5848 i386 running Mach i[3456]86-*-mach*
5849 i386 running OSF/1 i[3456]86-*osf1mk*
5850 HP/Apollo 68k Family m68*-apollo*-sysv*,
5852 m68*-hp-bsd*, m68*-hp-hpux*
5853 I960 with MON960 i960-*-coff
5855 * OBSOLETE languages
5857 CHILL, a Pascal like language used by telecommunications companies.
5859 * REMOVED configurations and files
5861 AMD 29k family via UDI a29k-amd-udi, udi29k
5862 A29K VxWorks a29k-*-vxworks
5863 AMD 29000 embedded, using EBMON a29k-none-none
5864 AMD 29000 embedded with COFF a29k-none-coff
5865 AMD 29000 embedded with a.out a29k-none-aout
5867 testsuite/gdb.hp/gdb.threads-hp/ directory
5869 * New command "set max-user-call-depth <nnn>"
5871 This command allows the user to limit the call depth of user-defined
5872 commands. The default is 1024.
5874 * Changes in FreeBSD/i386 native debugging.
5876 Support for the "generate-core-file" has been added.
5878 * New commands "dump", "append", and "restore".
5880 These commands allow data to be copied from target memory
5881 to a bfd-format or binary file (dump and append), and back
5882 from a file into memory (restore).
5884 * Improved "next/step" support on multi-processor Alpha Tru64.
5886 The previous single-step mechanism could cause unpredictable problems,
5887 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5888 of a software single-step mechanism prevents this.
5890 *** Changes in GDB 5.2.1:
5898 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5899 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5900 Fix, by Joel Brobecker imported from mainline.
5902 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5903 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5904 Fix, by Fred Fish, imported from mainline.
5906 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5907 Surprisingly enough, it works now.
5908 By Michal Ludvig, imported from mainline.
5910 i386 hardware watchpoint support:
5911 avoid misses on second run for some targets.
5912 By Pierre Muller, imported from mainline.
5914 *** Changes in GDB 5.2:
5916 * New command "set trust-readonly-sections on[off]".
5918 This command is a hint that tells gdb that read-only sections
5919 really are read-only (ie. that their contents will not change).
5920 In this mode, gdb will go to the object file rather than the
5921 target to read memory from read-only sections (such as ".text").
5922 This can be a significant performance improvement on some
5923 (notably embedded) targets.
5925 * New command "generate-core-file" (or "gcore").
5927 This new gdb command allows the user to drop a core file of the child
5928 process state at any time. So far it's been implemented only for
5929 GNU/Linux and Solaris, but should be relatively easily ported to other
5930 hosts. Argument is core file name (defaults to core.<pid>).
5932 * New command line option
5934 GDB now accepts --pid or -p followed by a process id.
5936 * Change in command line behavior -- corefiles vs. process ids.
5938 There is a subtle behavior in the way in which GDB handles
5939 command line arguments. The first non-flag argument is always
5940 a program to debug, but the second non-flag argument may either
5941 be a corefile or a process id. Previously, GDB would attempt to
5942 open the second argument as a corefile, and if that failed, would
5943 issue a superfluous error message and then attempt to attach it as
5944 a process. Now, if the second argument begins with a non-digit,
5945 it will be treated as a corefile. If it begins with a digit,
5946 GDB will attempt to attach it as a process, and if no such process
5947 is found, will then attempt to open it as a corefile.
5949 * Changes in ARM configurations.
5951 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5952 configuration is fully multi-arch.
5954 * New native configurations
5956 ARM NetBSD arm*-*-netbsd*
5957 x86 OpenBSD i[3456]86-*-openbsd*
5958 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5959 Sparc64 running FreeBSD sparc64-*-freebsd*
5963 Sanyo XStormy16 xstormy16-elf
5965 * OBSOLETE configurations and files
5967 Configurations that have been declared obsolete in this release have
5968 been commented out. Unless there is activity to revive these
5969 configurations, the next release of GDB will have their sources
5970 permanently REMOVED.
5972 AMD 29k family via UDI a29k-amd-udi, udi29k
5973 A29K VxWorks a29k-*-vxworks
5974 AMD 29000 embedded, using EBMON a29k-none-none
5975 AMD 29000 embedded with COFF a29k-none-coff
5976 AMD 29000 embedded with a.out a29k-none-aout
5978 testsuite/gdb.hp/gdb.threads-hp/ directory
5980 * REMOVED configurations and files
5982 TI TMS320C80 tic80-*-*
5984 PowerPC Solaris powerpcle-*-solaris*
5985 PowerPC Windows NT powerpcle-*-cygwin32
5986 PowerPC Netware powerpc-*-netware*
5987 Harris/CXUX m88k m88*-harris-cxux*
5988 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5989 ns32k-utek-sysv* ns32k-utek-*
5990 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5991 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5992 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5993 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5994 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5996 * Changes to command line processing
5998 The new `--args' feature can be used to specify command-line arguments
5999 for the inferior from gdb's command line.
6001 * Changes to key bindings
6003 There is a new `operate-and-get-next' function bound to `C-o'.
6005 *** Changes in GDB 5.1.1
6007 Fix compile problem on DJGPP.
6009 Fix a problem with floating-point registers on the i386 being
6012 Fix to stop GDB crashing on .debug_str debug info.
6014 Numerous documentation fixes.
6016 Numerous testsuite fixes.
6018 *** Changes in GDB 5.1:
6020 * New native configurations
6022 Alpha FreeBSD alpha*-*-freebsd*
6023 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6024 MIPS GNU/Linux mips*-*-linux*
6025 MIPS SGI Irix 6.x mips*-sgi-irix6*
6026 ia64 AIX ia64-*-aix*
6027 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6031 Motorola 68HC11 and 68HC12 m68hc11-elf
6033 UltraSparc running GNU/Linux sparc64-*-linux*
6035 * OBSOLETE configurations and files
6037 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6038 Harris/CXUX m88k m88*-harris-cxux*
6039 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6040 ns32k-utek-sysv* ns32k-utek-*
6041 TI TMS320C80 tic80-*-*
6043 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6044 PowerPC Solaris powerpcle-*-solaris*
6045 PowerPC Windows NT powerpcle-*-cygwin32
6046 PowerPC Netware powerpc-*-netware*
6047 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6048 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6049 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6050 Apple Macintosh (MPW) host N/A
6052 stuff.c (Program to stuff files into a specially prepared space in kdb)
6053 kdb-start.c (Main loop for the standalone kernel debugger)
6055 Configurations that have been declared obsolete in this release have
6056 been commented out. Unless there is activity to revive these
6057 configurations, the next release of GDB will have their sources
6058 permanently REMOVED.
6060 * REMOVED configurations and files
6062 Altos 3068 m68*-altos-*
6063 Convex c1-*-*, c2-*-*
6065 ARM RISCix arm-*-* (as host)
6069 * GDB has been converted to ISO C.
6071 GDB's source code has been converted to ISO C. In particular, the
6072 sources are fully protoized, and rely on standard headers being
6077 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6079 * The MI enabled by default.
6081 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6082 revised and enabled by default. Packages which use GDB as a debugging
6083 engine behind a UI or another front end are encouraged to switch to
6084 using the GDB/MI interface, instead of the old annotations interface
6085 which is now deprecated.
6087 * Support for debugging Pascal programs.
6089 GDB now includes support for debugging Pascal programs. The following
6090 main features are supported:
6092 - Pascal-specific data types such as sets;
6094 - automatic recognition of Pascal sources based on file-name
6097 - Pascal-style display of data types, variables, and functions;
6099 - a Pascal expression parser.
6101 However, some important features are not yet supported.
6103 - Pascal string operations are not supported at all;
6105 - there are some problems with boolean types;
6107 - Pascal type hexadecimal constants are not supported
6108 because they conflict with the internal variables format;
6110 - support for Pascal objects and classes is not full yet;
6112 - unlike Pascal, GDB is case-sensitive for symbol names.
6114 * Changes in completion.
6116 Commands such as `shell', `run' and `set args', which pass arguments
6117 to inferior programs, now complete on file names, similar to what
6118 users expect at the shell prompt.
6120 Commands which accept locations, such as `disassemble', `print',
6121 `breakpoint', `until', etc. now complete on filenames as well as
6122 program symbols. Thus, if you type "break foob TAB", and the source
6123 files linked into the programs include `foobar.c', that file name will
6124 be one of the candidates for completion. However, file names are not
6125 considered for completion after you typed a colon that delimits a file
6126 name from a name of a function in that file, as in "break foo.c:bar".
6128 `set demangle-style' completes on available demangling styles.
6130 * New platform-independent commands:
6132 It is now possible to define a post-hook for a command as well as a
6133 hook that runs before the command. For more details, see the
6134 documentation of `hookpost' in the GDB manual.
6136 * Changes in GNU/Linux native debugging.
6138 Support for debugging multi-threaded programs has been completely
6139 revised for all platforms except m68k and sparc. You can now debug as
6140 many threads as your system allows you to have.
6142 Attach/detach is supported for multi-threaded programs.
6144 Support for SSE registers was added for x86. This doesn't work for
6145 multi-threaded programs though.
6147 * Changes in MIPS configurations.
6149 Multi-arch support is enabled for all MIPS configurations.
6151 GDB can now be built as native debugger on SGI Irix 6.x systems for
6152 debugging n32 executables. (Debugging 64-bit executables is not yet
6155 * Unified support for hardware watchpoints in all x86 configurations.
6157 Most (if not all) native x86 configurations support hardware-assisted
6158 breakpoints and watchpoints in a unified manner. This support
6159 implements debug register sharing between watchpoints, which allows to
6160 put a virtually infinite number of watchpoints on the same address,
6161 and also supports watching regions up to 16 bytes with several debug
6164 The new maintenance command `maintenance show-debug-regs' toggles
6165 debugging print-outs in functions that insert, remove, and test
6166 watchpoints and hardware breakpoints.
6168 * Changes in the DJGPP native configuration.
6170 New command ``info dos sysinfo'' displays assorted information about
6171 the CPU, OS, memory, and DPMI server.
6173 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6174 display information about segment descriptors stored in GDT, LDT, and
6177 New commands ``info dos pde'' and ``info dos pte'' display entries
6178 from Page Directory and Page Tables (for now works with CWSDPMI only).
6179 New command ``info dos address-pte'' displays the Page Table entry for
6180 a given linear address.
6182 GDB can now pass command lines longer than 126 characters to the
6183 program being debugged (requires an update to the libdbg.a library
6184 which is part of the DJGPP development kit).
6186 DWARF2 debug info is now supported.
6188 It is now possible to `step' and `next' through calls to `longjmp'.
6190 * Changes in documentation.
6192 All GDB documentation was converted to GFDL, the GNU Free
6193 Documentation License.
6195 Tracepoints-related commands are now fully documented in the GDB
6198 TUI, the Text-mode User Interface, is now documented in the manual.
6200 Tracepoints-related commands are now fully documented in the GDB
6203 The "GDB Internals" manual now has an index. It also includes
6204 documentation of `ui_out' functions, GDB coding standards, x86
6205 hardware watchpoints, and memory region attributes.
6207 * GDB's version number moved to ``version.in''
6209 The Makefile variable VERSION has been replaced by the file
6210 ``version.in''. People creating GDB distributions should update the
6211 contents of this file.
6215 GUD support is now a standard part of the EMACS distribution.
6217 *** Changes in GDB 5.0:
6219 * Improved support for debugging FP programs on x86 targets
6221 Unified and much-improved support for debugging floating-point
6222 programs on all x86 targets. In particular, ``info float'' now
6223 displays the FP registers in the same format on all x86 targets, with
6224 greater level of detail.
6226 * Improvements and bugfixes in hardware-assisted watchpoints
6228 It is now possible to watch array elements, struct members, and
6229 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6230 on x86 targets no longer erroneously trigger when the address is
6233 * Improvements in the native DJGPP version of GDB
6235 The distribution now includes all the scripts and auxiliary files
6236 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6237 machines ``out of the box''.
6239 The DJGPP version can now debug programs that use signals. It is
6240 possible to catch signals that happened in the debuggee, deliver
6241 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6242 would kill the program being debugged.) Programs that hook hardware
6243 interrupts (keyboard, timer, etc.) can also be debugged.
6245 It is now possible to debug DJGPP programs that redirect their
6246 standard handles or switch them to raw (as opposed to cooked) mode, or
6247 even close them. The command ``run < foo > bar'' works as expected,
6248 and ``info terminal'' reports useful information about the debuggee's
6249 terminal, including raw/cooked mode, redirection, etc.
6251 The DJGPP version now uses termios functions for console I/O, which
6252 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6255 DOS-style file names with drive letters are now fully supported by
6258 It is now possible to debug DJGPP programs that switch their working
6259 directory. It is also possible to rerun the debuggee any number of
6260 times without restarting GDB; thus, you can use the same setup,
6261 breakpoints, etc. for many debugging sessions.
6263 * New native configurations
6265 ARM GNU/Linux arm*-*-linux*
6266 PowerPC GNU/Linux powerpc-*-linux*
6270 Motorola MCore mcore-*-*
6271 x86 VxWorks i[3456]86-*-vxworks*
6272 PowerPC VxWorks powerpc-*-vxworks*
6273 TI TMS320C80 tic80-*-*
6275 * OBSOLETE configurations
6277 Altos 3068 m68*-altos-*
6278 Convex c1-*-*, c2-*-*
6280 ARM RISCix arm-*-* (as host)
6283 Configurations that have been declared obsolete will be commented out,
6284 but the code will be left in place. If there is no activity to revive
6285 these configurations before the next release of GDB, the sources will
6286 be permanently REMOVED.
6288 * Gould support removed
6290 Support for the Gould PowerNode and NP1 has been removed.
6292 * New features for SVR4
6294 On SVR4 native platforms (such as Solaris), if you attach to a process
6295 without first loading a symbol file, GDB will now attempt to locate and
6296 load symbols from the running process's executable file.
6298 * Many C++ enhancements
6300 C++ support has been greatly improved. Overload resolution now works properly
6301 in almost all cases. RTTI support is on the way.
6303 * Remote targets can connect to a sub-program
6305 A popen(3) style serial-device has been added. This device starts a
6306 sub-process (such as a stand-alone simulator) and then communicates
6307 with that. The sub-program to run is specified using the syntax
6308 ``|<program> <args>'' vis:
6310 (gdb) set remotedebug 1
6311 (gdb) target extended-remote |mn10300-elf-sim program-args
6313 * MIPS 64 remote protocol
6315 A long standing bug in the mips64 remote protocol where by GDB
6316 expected certain 32 bit registers (ex SR) to be transfered as 32
6317 instead of 64 bits has been fixed.
6319 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6320 added to provide backward compatibility with older versions of GDB.
6322 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6324 The command ``set remotebinarydownload'' command has been replaced by
6325 ``set remote X-packet''. Other commands in ``set remote'' family
6326 include ``set remote P-packet''.
6328 * Breakpoint commands accept ranges.
6330 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6331 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6332 ``tracepoint passcount'' also accepts a range of tracepoints.
6334 * ``apropos'' command added.
6336 The ``apropos'' command searches through command names and
6337 documentation strings, printing out matches, making it much easier to
6338 try to find a command that does what you are looking for.
6342 A new machine oriented interface (MI) has been added to GDB. This
6343 interface is designed for debug environments running GDB as a separate
6344 process. This is part of the long term libGDB project. See the
6345 "GDB/MI" chapter of the GDB manual for further information. It can be
6346 enabled by configuring with:
6348 .../configure --enable-gdbmi
6350 *** Changes in GDB-4.18:
6352 * New native configurations
6354 HP-UX 10.20 hppa*-*-hpux10.20
6355 HP-UX 11.x hppa*-*-hpux11.0*
6356 M68K GNU/Linux m68*-*-linux*
6360 Fujitsu FR30 fr30-*-elf*
6361 Intel StrongARM strongarm-*-*
6362 Mitsubishi D30V d30v-*-*
6364 * OBSOLETE configurations
6366 Gould PowerNode, NP1 np1-*-*, pn-*-*
6368 Configurations that have been declared obsolete will be commented out,
6369 but the code will be left in place. If there is no activity to revive
6370 these configurations before the next release of GDB, the sources will
6371 be permanently REMOVED.
6375 As a compatibility experiment, GDB's source files buildsym.h and
6376 buildsym.c have been converted to pure standard C, no longer
6377 containing any K&R compatibility code. We believe that all systems in
6378 use today either come with a standard C compiler, or have a GCC port
6379 available. If this is not true, please report the affected
6380 configuration to bug-gdb@gnu.org immediately. See the README file for
6381 information about getting a standard C compiler if you don't have one
6386 GDB now uses readline 2.2.
6388 * set extension-language
6390 You can now control the mapping between filename extensions and source
6391 languages by using the `set extension-language' command. For instance,
6392 you can ask GDB to treat .c files as C++ by saying
6393 set extension-language .c c++
6394 The command `info extensions' lists all of the recognized extensions
6395 and their associated languages.
6397 * Setting processor type for PowerPC and RS/6000
6399 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6400 you can use the `set processor' command to specify what variant of the
6401 PowerPC family you are debugging. The command
6405 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6406 following PowerPC and RS6000 variants:
6408 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6409 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6411 403GC IBM PowerPC 403GC
6412 505 Motorola PowerPC 505
6413 860 Motorola PowerPC 860 or 850
6414 601 Motorola PowerPC 601
6415 602 Motorola PowerPC 602
6416 603 Motorola/IBM PowerPC 603 or 603e
6417 604 Motorola PowerPC 604 or 604e
6418 750 Motorola/IBM PowerPC 750 or 750
6420 At the moment, this command just tells GDB what to name the
6421 special-purpose processor registers. Since almost all the affected
6422 registers are inaccessible to user-level programs, this command is
6423 only useful for remote debugging in its present form.
6427 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6428 more extensive support for HP-UX. Added features include shared
6429 library support, kernel threads and hardware watchpoints for 11.00,
6430 support for HP's ANSI C and C++ compilers, and a compatibility mode
6431 for xdb and dbx commands.
6435 HP's donation includes the new concept of catchpoints, which is a
6436 generalization of the old catch command. On HP-UX, it is now possible
6437 to catch exec, fork, and vfork, as well as library loading.
6439 This means that the existing catch command has changed; its first
6440 argument now specifies the type of catch to be set up. See the
6441 output of "help catch" for a list of catchpoint types.
6443 * Debugging across forks
6445 On HP-UX, you can choose which process to debug when a fork() happens
6450 HP has donated a curses-based terminal user interface (TUI). To get
6451 it, build with --enable-tui. Although this can be enabled for any
6452 configuration, at present it only works for native HP debugging.
6454 * GDB remote protocol additions
6456 A new protocol packet 'X' that writes binary data is now available.
6457 Default behavior is to try 'X', then drop back to 'M' if the stub
6458 fails to respond. The settable variable `remotebinarydownload'
6459 allows explicit control over the use of 'X'.
6461 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6462 full 64-bit address. The command
6464 set remoteaddresssize 32
6466 can be used to revert to the old behaviour. For existing remote stubs
6467 the change should not be noticed, as the additional address information
6470 In order to assist in debugging stubs, you may use the maintenance
6471 command `packet' to send any text string to the stub. For instance,
6473 maint packet heythere
6475 sends the packet "$heythere#<checksum>". Note that it is very easy to
6476 disrupt a debugging session by sending the wrong packet at the wrong
6479 The compare-sections command allows you to compare section data on the
6480 target to what is in the executable file without uploading or
6481 downloading, by comparing CRC checksums.
6483 * Tracing can collect general expressions
6485 You may now collect general expressions at tracepoints. This requires
6486 further additions to the target-side stub; see tracepoint.c and
6487 doc/agentexpr.texi for further details.
6489 * mask-address variable for Mips
6491 For Mips targets, you may control the zeroing of the upper 32 bits of
6492 a 64-bit address by entering `set mask-address on'. This is mainly
6493 of interest to users of embedded R4xxx and R5xxx processors.
6495 * Higher serial baud rates
6497 GDB's serial code now allows you to specify baud rates 57600, 115200,
6498 230400, and 460800 baud. (Note that your host system may not be able
6499 to achieve all of these rates.)
6503 The i960 configuration now includes an initial implementation of a
6504 builtin simulator, contributed by Jim Wilson.
6507 *** Changes in GDB-4.17:
6509 * New native configurations
6511 Alpha GNU/Linux alpha*-*-linux*
6512 Unixware 2.x i[3456]86-unixware2*
6513 Irix 6.x mips*-sgi-irix6*
6514 PowerPC GNU/Linux powerpc-*-linux*
6515 PowerPC Solaris powerpcle-*-solaris*
6516 Sparc GNU/Linux sparc-*-linux*
6517 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6521 Argonaut Risc Chip (ARC) arc-*-*
6522 Hitachi H8/300S h8300*-*-*
6523 Matsushita MN10200 w/simulator mn10200-*-*
6524 Matsushita MN10300 w/simulator mn10300-*-*
6525 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6526 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6527 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6528 Mitsubishi D10V w/simulator d10v-*-*
6529 Mitsubishi M32R/D w/simulator m32r-*-elf*
6530 Tsqware Sparclet sparclet-*-*
6531 NEC V850 w/simulator v850-*-*
6533 * New debugging protocols
6535 ARM with RDI protocol arm*-*-*
6536 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6537 DDB and LSI variants of PMON protocol mips*-*-*
6538 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6539 PowerPC with SDS protocol powerpc{,le}-*-eabi
6540 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6544 All configurations can now understand and use the DWARF 2 debugging
6545 format. The choice is automatic, if the symbol file contains DWARF 2
6550 GDB now includes basic Java language support. This support is
6551 only useful with Java compilers that produce native machine code.
6553 * solib-absolute-prefix and solib-search-path
6555 For SunOS and SVR4 shared libraries, you may now set the prefix for
6556 loading absolute shared library symbol files, and the search path for
6557 locating non-absolute shared library symbol files.
6559 * Live range splitting
6561 GDB can now effectively debug code for which GCC has performed live
6562 range splitting as part of its optimization. See gdb/doc/LRS for
6563 more details on the expected format of the stabs information.
6567 GDB's support for the GNU Hurd, including thread debugging, has been
6568 updated to work with current versions of the Hurd.
6572 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6573 instruction set. ARM GDB automatically detects when Thumb
6574 instructions are in use, and adjusts disassembly and backtracing
6579 GDB's MIPS target configurations now handle the MIP16 16-bit
6584 GDB now includes support for overlays; if an executable has been
6585 linked such that multiple sections are based at the same address, GDB
6586 will decide which section to use for symbolic info. You can choose to
6587 control the decision manually, using overlay commands, or implement
6588 additional target-side support and use "overlay load-target" to bring
6589 in the overlay mapping. Do "help overlay" for more detail.
6593 The command "info symbol <address>" displays information about
6594 the symbol at the specified address.
6598 The standard remote protocol now includes an extension that allows
6599 asynchronous collection and display of trace data. This requires
6600 extensive support in the target-side debugging stub. Tracing mode
6601 includes a new interaction mode in GDB and new commands: see the
6602 file tracepoint.c for more details.
6606 Configurations for embedded MIPS now include a simulator contributed
6607 by Cygnus Solutions. The simulator supports the instruction sets
6608 of most MIPS variants.
6612 Sparc configurations may now include the ERC32 simulator contributed
6613 by the European Space Agency. The simulator is not built into
6614 Sparc targets by default; configure with --enable-sim to include it.
6618 For target configurations that may include multiple variants of a
6619 basic architecture (such as MIPS and SH), you may now set the
6620 architecture explicitly. "set arch" sets, "info arch" lists
6621 the possible architectures.
6623 *** Changes in GDB-4.16:
6625 * New native configurations
6627 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6628 M68K NetBSD m68k-*-netbsd*
6629 PowerPC AIX 4.x powerpc-*-aix*
6630 PowerPC MacOS powerpc-*-macos*
6631 PowerPC Windows NT powerpcle-*-cygwin32
6632 RS/6000 AIX 4.x rs6000-*-aix4*
6636 ARM with RDP protocol arm-*-*
6637 I960 with MON960 i960-*-coff
6638 MIPS VxWorks mips*-*-vxworks*
6639 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6640 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6642 Matra Sparclet sparclet-*-*
6646 The powerpc-eabi configuration now includes the PSIM simulator,
6647 contributed by Andrew Cagney, with assistance from Mike Meissner.
6648 PSIM is a very elaborate model of the PowerPC, including not only
6649 basic instruction set execution, but also details of execution unit
6650 performance and I/O hardware. See sim/ppc/README for more details.
6654 GDB now works with Solaris 2.5.
6656 * Windows 95/NT native
6658 GDB will now work as a native debugger on Windows 95 and Windows NT.
6659 To build it from source, you must use the "gnu-win32" environment,
6660 which uses a DLL to emulate enough of Unix to run the GNU tools.
6661 Further information, binaries, and sources are available at
6662 ftp.cygnus.com, under pub/gnu-win32.
6664 * dont-repeat command
6666 If a user-defined command includes the command `dont-repeat', then the
6667 command will not be repeated if the user just types return. This is
6668 useful if the command is time-consuming to run, so that accidental
6669 extra keystrokes don't run the same command many times.
6671 * Send break instead of ^C
6673 The standard remote protocol now includes an option to send a break
6674 rather than a ^C to the target in order to interrupt it. By default,
6675 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6677 * Remote protocol timeout
6679 The standard remote protocol includes a new variable `remotetimeout'
6680 that allows you to set the number of seconds before GDB gives up trying
6681 to read from the target. The default value is 2.
6683 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6685 By default GDB will automatically keep track of objects as they are
6686 loaded and unloaded by the dynamic linker. By using the command `set
6687 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6688 when shared library events occur, thus allowing you to set breakpoints
6689 in shared libraries which are explicitly loaded by the inferior.
6691 Note this feature does not work on hpux8. On hpux9 you must link
6692 /usr/lib/end.o into your program. This feature should work
6693 automatically on hpux10.
6695 * Irix 5.x hardware watchpoint support
6697 Irix 5 configurations now support the use of hardware watchpoints.
6699 * Mips protocol "SYN garbage limit"
6701 When debugging a Mips target using the `target mips' protocol, you
6702 may set the number of characters that GDB will ignore by setting
6703 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6704 every character. The default value is 1050.
6706 * Recording and replaying remote debug sessions
6708 If you set `remotelogfile' to the name of a file, gdb will write to it
6709 a recording of a remote debug session. This recording may then be
6710 replayed back to gdb using "gdbreplay". See gdbserver/README for
6711 details. This is useful when you have a problem with GDB while doing
6712 remote debugging; you can make a recording of the session and send it
6713 to someone else, who can then recreate the problem.
6715 * Speedups for remote debugging
6717 GDB includes speedups for downloading and stepping MIPS systems using
6718 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6719 and more efficient S-record downloading.
6721 * Memory use reductions and statistics collection
6723 GDB now uses less memory and reports statistics about memory usage.
6724 Try the `maint print statistics' command, for example.
6726 *** Changes in GDB-4.15:
6728 * Psymtabs for XCOFF
6730 The symbol reader for AIX GDB now uses partial symbol tables. This
6731 can greatly improve startup time, especially for large executables.
6733 * Remote targets use caching
6735 Remote targets now use a data cache to speed up communication with the
6736 remote side. The data cache could lead to incorrect results because
6737 it doesn't know about volatile variables, thus making it impossible to
6738 debug targets which use memory mapped I/O devices. `set remotecache
6739 off' turns the data cache off.
6741 * Remote targets may have threads
6743 The standard remote protocol now includes support for multiple threads
6744 in the target system, using new protocol commands 'H' and 'T'. See
6745 gdb/remote.c for details.
6749 If GDB is configured with `--enable-netrom', then it will include
6750 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6751 acts as though it is a bank of ROM on the target board, but you can
6752 write into it over the network. GDB's support consists only of
6753 support for fast loading into the emulated ROM; to debug, you must use
6754 another protocol, such as standard remote protocol. The usual
6755 sequence is something like
6757 target nrom <netrom-hostname>
6759 target remote <netrom-hostname>:1235
6763 GDB now includes support for the Apple Macintosh, as a host only. It
6764 may be run as either an MPW tool or as a standalone application, and
6765 it can debug through the serial port. All the usual GDB commands are
6766 available, but to the target command, you must supply "serial" as the
6767 device type instead of "/dev/ttyXX". See mpw-README in the main
6768 directory for more information on how to build. The MPW configuration
6769 scripts */mpw-config.in support only a few targets, and only the
6770 mips-idt-ecoff target has been tested.
6774 GDB configuration now uses autoconf. This is not user-visible,
6775 but does simplify configuration and building.
6779 GDB now supports hpux10.
6781 *** Changes in GDB-4.14:
6783 * New native configurations
6785 x86 FreeBSD i[345]86-*-freebsd
6786 x86 NetBSD i[345]86-*-netbsd
6787 NS32k NetBSD ns32k-*-netbsd
6788 Sparc NetBSD sparc-*-netbsd
6792 A29K VxWorks a29k-*-vxworks
6793 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6794 CPU32 EST-300 emulator m68*-*-est*
6795 PowerPC ELF powerpc-*-elf
6798 * Alpha OSF/1 support for procfs
6800 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6801 possible to attach to running processes. As the mounting of the /proc
6802 filesystem is optional on the Alpha, GDB automatically determines
6803 the availability of /proc during startup. This can lead to problems
6804 if /proc is unmounted after GDB has been started.
6806 * Arguments to user-defined commands
6808 User commands may accept up to 10 arguments separated by whitespace.
6809 Arguments are accessed within the user command via $arg0..$arg9. A
6812 print $arg0 + $arg1 + $arg2
6814 To execute the command use:
6817 Defines the command "adder" which prints the sum of its three arguments.
6818 Note the arguments are text substitutions, so they may reference variables,
6819 use complex expressions, or even perform inferior function calls.
6821 * New `if' and `while' commands
6823 This makes it possible to write more sophisticated user-defined
6824 commands. Both commands take a single argument, which is the
6825 expression to evaluate, and must be followed by the commands to
6826 execute, one per line, if the expression is nonzero, the list being
6827 terminated by the word `end'. The `if' command list may include an
6828 `else' word, which causes the following commands to be executed only
6829 if the expression is zero.
6831 * Fortran source language mode
6833 GDB now includes partial support for Fortran 77. It will recognize
6834 Fortran programs and can evaluate a subset of Fortran expressions, but
6835 variables and functions may not be handled correctly. GDB will work
6836 with G77, but does not yet know much about symbols emitted by other
6839 * Better HPUX support
6841 Most debugging facilities now work on dynamic executables for HPPAs
6842 running hpux9 or later. You can attach to running dynamically linked
6843 processes, but by default the dynamic libraries will be read-only, so
6844 for instance you won't be able to put breakpoints in them. To change
6845 that behavior do the following before running the program:
6851 This will cause the libraries to be mapped private and read-write.
6852 To revert to the normal behavior, do this:
6858 You cannot set breakpoints or examine data in the library until after
6859 the library is loaded if the function/data symbols do not have
6862 GDB can now also read debug symbols produced by the HP C compiler on
6863 HPPAs (sorry, no C++, Fortran or 68k support).
6865 * Target byte order now dynamically selectable
6867 You can choose which byte order to use with a target system, via the
6868 commands "set endian big" and "set endian little", and you can see the
6869 current setting by using "show endian". You can also give the command
6870 "set endian auto", in which case GDB will use the byte order
6871 associated with the executable. Currently, only embedded MIPS
6872 configurations support dynamic selection of target byte order.
6874 * New DOS host serial code
6876 This version uses DPMI interrupts to handle buffered I/O, so you
6877 no longer need to run asynctsr when debugging boards connected to
6880 *** Changes in GDB-4.13:
6882 * New "complete" command
6884 This lists all the possible completions for the rest of the line, if it
6885 were to be given as a command itself. This is intended for use by emacs.
6887 * Trailing space optional in prompt
6889 "set prompt" no longer adds a space for you after the prompt you set. This
6890 allows you to set a prompt which ends in a space or one that does not.
6892 * Breakpoint hit counts
6894 "info break" now displays a count of the number of times the breakpoint
6895 has been hit. This is especially useful in conjunction with "ignore"; you
6896 can ignore a large number of breakpoint hits, look at the breakpoint info
6897 to see how many times the breakpoint was hit, then run again, ignoring one
6898 less than that number, and this will get you quickly to the last hit of
6901 * Ability to stop printing at NULL character
6903 "set print null-stop" will cause GDB to stop printing the characters of
6904 an array when the first NULL is encountered. This is useful when large
6905 arrays actually contain only short strings.
6907 * Shared library breakpoints
6909 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6910 breakpoints in shared libraries before the executable is run.
6912 * Hardware watchpoints
6914 There is a new hardware breakpoint for the watch command for sparclite
6915 targets. See gdb/sparclite/hw_breakpoint.note.
6917 Hardware watchpoints are also now supported under GNU/Linux.
6921 Annotations have been added. These are for use with graphical interfaces,
6922 and are still experimental. Currently only gdba.el uses these.
6924 * Improved Irix 5 support
6926 GDB now works properly with Irix 5.2.
6928 * Improved HPPA support
6930 GDB now works properly with the latest GCC and GAS.
6932 * New native configurations
6934 Sequent PTX4 i[34]86-sequent-ptx4
6935 HPPA running OSF/1 hppa*-*-osf*
6936 Atari TT running SVR4 m68*-*-sysv4*
6937 RS/6000 LynxOS rs6000-*-lynxos*
6941 OS/9000 i[34]86-*-os9k
6942 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6945 * Hitachi SH7000 and E7000-PC ICE support
6947 There is now support for communicating with the Hitachi E7000-PC ICE.
6948 This is available automatically when GDB is configured for the SH.
6952 As usual, a variety of small fixes and improvements, both generic
6953 and configuration-specific. See the ChangeLog for more detail.
6955 *** Changes in GDB-4.12:
6957 * Irix 5 is now supported
6961 GDB-4.12 on the HPPA has a number of changes which make it unable
6962 to debug the output from the currently released versions of GCC and
6963 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6964 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6965 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6968 *** Changes in GDB-4.11:
6970 * User visible changes:
6974 The "set remotedebug" option is now consistent between the mips remote
6975 target, remote targets using the gdb-specific protocol, UDI (AMD's
6976 debug protocol for the 29k) and the 88k bug monitor. It is now an
6977 integer specifying a debug level (normally 0 or 1, but 2 means more
6978 debugging info for the mips target).
6980 * DEC Alpha native support
6982 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6983 debug info, but GDB works fairly well with the DEC compiler and should
6984 work with a future GCC release. See the README file for a few
6985 Alpha-specific notes.
6987 * Preliminary thread implementation
6989 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6991 * LynxOS native and target support for 386
6993 This release has been hosted on LynxOS 2.2, and also can be configured
6994 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6997 * Improvements in C++ mangling/demangling.
6999 This release has much better g++ debugging, specifically in name
7000 mangling/demangling, virtual function calls, print virtual table,
7001 call methods, ...etc.
7003 *** Changes in GDB-4.10:
7005 * User visible changes:
7007 Remote debugging using the GDB-specific (`target remote') protocol now
7008 supports the `load' command. This is only useful if you have some
7009 other way of getting the stub to the target system, and you can put it
7010 somewhere in memory where it won't get clobbered by the download.
7012 Filename completion now works.
7014 When run under emacs mode, the "info line" command now causes the
7015 arrow to point to the line specified. Also, "info line" prints
7016 addresses in symbolic form (as well as hex).
7018 All vxworks based targets now support a user settable option, called
7019 vxworks-timeout. This option represents the number of seconds gdb
7020 should wait for responses to rpc's. You might want to use this if
7021 your vxworks target is, perhaps, a slow software simulator or happens
7022 to be on the far side of a thin network line.
7026 This release contains support for using a DEC alpha as a GDB host for
7027 cross debugging. Native alpha debugging is not supported yet.
7030 *** Changes in GDB-4.9:
7034 This is the first GDB release which is accompanied by a matching testsuite.
7035 The testsuite requires installation of dejagnu, which should be available
7036 via ftp from most sites that carry GNU software.
7040 'Cfront' style demangling has had its name changed to 'ARM' style, to
7041 emphasize that it was written from the specifications in the C++ Annotated
7042 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7043 disclaimers, it still generated too much confusion with users attempting to
7044 use gdb with AT&T cfront.
7048 GDB now uses a standard remote interface to a simulator library.
7049 So far, the library contains simulators for the Zilog Z8001/2, the
7050 Hitachi H8/300, H8/500 and Super-H.
7052 * New targets supported
7054 H8/300 simulator h8300-hitachi-hms or h8300hms
7055 H8/500 simulator h8500-hitachi-hms or h8500hms
7056 SH simulator sh-hitachi-hms or sh
7057 Z8000 simulator z8k-zilog-none or z8ksim
7058 IDT MIPS board over serial line mips-idt-ecoff
7060 Cross-debugging to GO32 targets is supported. It requires a custom
7061 version of the i386-stub.c module which is integrated with the
7062 GO32 memory extender.
7064 * New remote protocols
7066 MIPS remote debugging protocol.
7068 * New source languages supported
7070 This version includes preliminary support for Chill, a Pascal like language
7071 used by telecommunications companies. Chill support is also being integrated
7072 into the GNU compiler, but we don't know when it will be publically available.
7075 *** Changes in GDB-4.8:
7077 * HP Precision Architecture supported
7079 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7080 version of this support was available as a set of patches from the
7081 University of Utah. GDB does not support debugging of programs
7082 compiled with the HP compiler, because HP will not document their file
7083 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7084 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7086 Many problems in the preliminary version have been fixed.
7088 * Faster and better demangling
7090 We have improved template demangling and fixed numerous bugs in the GNU style
7091 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7092 character types (wchar_t) are now supported. Demangling of each symbol is now
7093 only done once, and is cached when the symbol table for a file is read in.
7094 This results in a small increase in memory usage for C programs, a moderate
7095 increase in memory usage for C++ programs, and a fantastic speedup in
7098 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7099 from the specifications in the Annotated Reference Manual, which AT&T's
7100 compiler does not actually implement.
7102 * G++ multiple inheritance compiler problem
7104 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7105 inheritance lattices was reworked to properly discover ambiguities. We
7106 recently found an example which causes this new algorithm to fail in a
7107 very subtle way, producing bad debug information for those classes.
7108 The file 'gcc.patch' (in this directory) can be applied to gcc to
7109 circumvent the problem. A future GCC release will contain a complete
7112 The previous G++ debug info problem (mentioned below for the gdb-4.7
7113 release) is fixed in gcc version 2.3.2.
7115 * Improved configure script
7117 The `configure' script will now attempt to guess your system type if
7118 you don't supply a host system type. The old scheme of supplying a
7119 host system triplet is preferable over using this. All the magic is
7120 done in the new `config.guess' script. Examine it for details.
7122 We have also brought our configure script much more in line with the FSF's
7123 version. It now supports the --with-xxx options. In particular,
7124 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7125 The resulting GDB will not be able to read arbitrary object file formats --
7126 only the format ``expected'' to be used on the configured target system.
7127 We hope to make this the default in a future release.
7129 * Documentation improvements
7131 There's new internal documentation on how to modify GDB, and how to
7132 produce clean changes to the code. We implore people to read it
7133 before submitting changes.
7135 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7136 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7137 `info' files are also provided. To build `info' files from scratch,
7138 you will need the latest `makeinfo' release, which will be available in
7139 a future texinfo-X.Y release.
7141 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7142 We're not sure exactly which versions have this problem, but it has
7143 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7144 or better. If that isn't possible, there is a patch in
7145 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7146 around this problem.
7150 GDB now supports array constants that can be used in expressions typed in by
7151 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7152 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7155 The new directory `gdb/sparclite' contains a program that demonstrates
7156 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7158 * New native hosts supported
7160 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7161 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7163 * New targets supported
7165 AMD 29k family via UDI a29k-amd-udi or udi29k
7167 * New file formats supported
7169 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7170 HPUX core files, and SCO 3.2v2 core files.
7174 Attaching to processes now works again; thanks for the many bug reports.
7176 We have also stomped on a bunch of core dumps caused by
7177 printf_filtered("%s") problems.
7179 We eliminated a copyright problem on the rpc and ptrace header files
7180 for VxWorks, which was discovered at the last minute during the 4.7
7181 release. You should now be able to build a VxWorks GDB.
7183 You can now interrupt gdb while an attached process is running. This
7184 will cause the attached process to stop, and give control back to GDB.
7186 We fixed problems caused by using too many file descriptors
7187 for reading symbols from object files and libraries. This was
7188 especially a problem for programs that used many (~100) shared
7191 The `step' command now only enters a subroutine if there is line number
7192 information for the subroutine. Otherwise it acts like the `next'
7193 command. Previously, `step' would enter subroutines if there was
7194 any debugging information about the routine. This avoids problems
7195 when using `cc -g1' on MIPS machines.
7197 * Internal improvements
7199 GDB's internal interfaces have been improved to make it easier to support
7200 debugging of multiple languages in the future.
7202 GDB now uses a common structure for symbol information internally.
7203 Minimal symbols (derived from linkage symbols in object files), partial
7204 symbols (from a quick scan of debug information), and full symbols
7205 contain a common subset of information, making it easier to write
7206 shared code that handles any of them.
7208 * New command line options
7210 We now accept --silent as an alias for --quiet.
7214 The memory-mapped-malloc library is now licensed under the GNU Library
7215 General Public License.
7217 *** Changes in GDB-4.7:
7219 * Host/native/target split
7221 GDB has had some major internal surgery to untangle the support for
7222 hosts and remote targets. Now, when you configure GDB for a remote
7223 target, it will no longer load in all of the support for debugging
7224 local programs on the host. When fully completed and tested, this will
7225 ensure that arbitrary host/target combinations are possible.
7227 The primary conceptual shift is to separate the non-portable code in
7228 GDB into three categories. Host specific code is required any time GDB
7229 is compiled on that host, regardless of the target. Target specific
7230 code relates to the peculiarities of the target, but can be compiled on
7231 any host. Native specific code is everything else: it can only be
7232 built when the host and target are the same system. Child process
7233 handling and core file support are two common `native' examples.
7235 GDB's use of /proc for controlling Unix child processes is now cleaner.
7236 It has been split out into a single module under the `target_ops' vector,
7237 plus two native-dependent functions for each system that uses /proc.
7239 * New hosts supported
7241 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7242 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7243 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7245 * New targets supported
7247 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7248 68030 and CPU32 m68030-*-*, m68332-*-*
7250 * New native hosts supported
7252 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7253 (386bsd is not well tested yet)
7254 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7256 * New file formats supported
7258 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7259 supports reading of `a.out.adobe' object files, which are an a.out
7260 format extended with minimal information about multiple sections.
7264 `show copying' is the same as the old `info copying'.
7265 `show warranty' is the same as `info warrantee'.
7266 These were renamed for consistency. The old commands continue to work.
7268 `info handle' is a new alias for `info signals'.
7270 You can now define pre-command hooks, which attach arbitrary command
7271 scripts to any command. The commands in the hook will be executed
7272 prior to the user's command. You can also create a hook which will be
7273 executed whenever the program stops. See gdb.texinfo.
7277 We now deal with Cfront style name mangling, and can even extract type
7278 info from mangled symbols. GDB can automatically figure out which
7279 symbol mangling style your C++ compiler uses.
7281 Calling of methods and virtual functions has been improved as well.
7285 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7286 fixed. This was due to mishandling of the extra N_SO stabs output
7289 We also finally got Ultrix 4.2 running in house, and fixed core file
7290 support, with help from a dozen people on the net.
7292 John M. Farrell discovered that the reason that single-stepping was so
7293 slow on all of the Mips based platforms (primarily SGI and DEC) was
7294 that we were trying to demangle and lookup a symbol used for internal
7295 purposes on every instruction that was being stepped through. Changing
7296 the name of that symbol so that it couldn't be mistaken for a C++
7297 mangled symbol sped things up a great deal.
7299 Rich Pixley sped up symbol lookups in general by getting much smarter
7300 about when C++ symbol mangling is necessary. This should make symbol
7301 completion (TAB on the command line) much faster. It's not as fast as
7302 we'd like, but it's significantly faster than gdb-4.6.
7306 A new user controllable variable 'call_scratch_address' can
7307 specify the location of a scratch area to be used when GDB
7308 calls a function in the target. This is necessary because the
7309 usual method of putting the scratch area on the stack does not work
7310 in systems that have separate instruction and data spaces.
7312 We integrated changes to support the 29k UDI (Universal Debugger
7313 Interface), but discovered at the last minute that we didn't have all
7314 of the appropriate copyright paperwork. We are working with AMD to
7315 resolve this, and hope to have it available soon.
7319 We have sped up the remote serial line protocol, especially for targets
7320 with lots of registers. It now supports a new `expedited status' ('T')
7321 message which can be used in place of the existing 'S' status message.
7322 This allows the remote stub to send only the registers that GDB
7323 needs to make a quick decision about single-stepping or conditional
7324 breakpoints, eliminating the need to fetch the entire register set for
7325 each instruction being stepped through.
7327 The GDB remote serial protocol now implements a write-through cache for
7328 registers, only re-reading the registers if the target has run.
7330 There is also a new remote serial stub for SPARC processors. You can
7331 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7332 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7333 processor with a serial port.
7337 Configure.in files have become much easier to read and modify. A new
7338 `table driven' format makes it more obvious what configurations are
7339 supported, and what files each one uses.
7343 There is a new opcodes library which will eventually contain all of the
7344 disassembly routines and opcode tables. At present, it only contains
7345 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7346 disassembler (binutils/objdump) to share these routines.
7348 The libiberty library is now copylefted under the GNU Library General
7349 Public License. This allows more liberal use, and was done so libg++
7350 can use it. This makes no difference to GDB, since the Library License
7351 grants all the rights from the General Public License.
7355 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7356 reference to the stabs symbol info used by the debugger. It is (as far
7357 as we know) the only published document on this fascinating topic. We
7358 encourage you to read it, compare it to the stabs information on your
7359 system, and send improvements on the document in general (to
7360 bug-gdb@prep.ai.mit.edu).
7362 And, of course, many bugs have been fixed.
7365 *** Changes in GDB-4.6:
7367 * Better support for C++ function names
7369 GDB now accepts as input the "demangled form" of C++ overloaded function
7370 names and member function names, and can do command completion on such names
7371 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7372 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7373 Make use of command completion, it is your friend.
7375 GDB also now accepts a variety of C++ mangled symbol formats. They are
7376 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7377 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7378 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7379 for the list of formats.
7381 * G++ symbol mangling problem
7383 Recent versions of gcc have a bug in how they emit debugging information for
7384 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7385 directory) can be applied to gcc to fix the problem. Alternatively, if you
7386 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7387 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7388 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7391 * New 'maintenance' command
7393 All of the commands related to hacking GDB internals have been moved out of
7394 the main command set, and now live behind the 'maintenance' command. This
7395 can also be abbreviated as 'mt'. The following changes were made:
7397 dump-me -> maintenance dump-me
7398 info all-breakpoints -> maintenance info breakpoints
7399 printmsyms -> maintenance print msyms
7400 printobjfiles -> maintenance print objfiles
7401 printpsyms -> maintenance print psymbols
7402 printsyms -> maintenance print symbols
7404 The following commands are new:
7406 maintenance demangle Call internal GDB demangler routine to
7407 demangle a C++ link name and prints the result.
7408 maintenance print type Print a type chain for a given symbol
7410 * Change to .gdbinit file processing
7412 We now read the $HOME/.gdbinit file before processing the argv arguments
7413 (e.g. reading symbol files or core files). This allows global parameters to
7414 be set, which will apply during the symbol reading. The ./.gdbinit is still
7415 read after argv processing.
7417 * New hosts supported
7419 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7421 GNU/Linux support i386-unknown-linux or linux
7423 We are also including code to support the HP/PA running BSD and HPUX. This
7424 is almost guaranteed not to work, as we didn't have time to test or build it
7425 for this release. We are including it so that the more adventurous (or
7426 masochistic) of you can play with it. We also had major problems with the
7427 fact that the compiler that we got from HP doesn't support the -g option.
7430 * New targets supported
7432 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7434 * More smarts about finding #include files
7436 GDB now remembers the compilation directory for all include files, and for
7437 all files from which C is generated (like yacc and lex sources). This
7438 greatly improves GDB's ability to find yacc/lex sources, and include files,
7439 especially if you are debugging your program from a directory different from
7440 the one that contains your sources.
7442 We also fixed a bug which caused difficulty with listing and setting
7443 breakpoints in include files which contain C code. (In the past, you had to
7444 try twice in order to list an include file that you hadn't looked at before.)
7446 * Interesting infernals change
7448 GDB now deals with arbitrary numbers of sections, where the symbols for each
7449 section must be relocated relative to that section's landing place in the
7450 target's address space. This work was needed to support ELF with embedded
7451 stabs used by Solaris-2.0.
7453 * Bug fixes (of course!)
7455 There have been loads of fixes for the following things:
7456 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7457 i960, stabs, DOS(GO32), procfs, etc...
7459 See the ChangeLog for details.
7461 *** Changes in GDB-4.5:
7463 * New machines supported (host and target)
7465 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7467 SGI Irix-4.x mips-sgi-irix4 or iris4
7469 * New malloc package
7471 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7472 Mmalloc is capable of handling multiple heaps of memory. It is also
7473 capable of saving a heap to a file, and then mapping it back in later.
7474 This can be used to greatly speedup the startup of GDB by using a
7475 pre-parsed symbol table which lives in a mmalloc managed heap. For
7476 more details, please read mmalloc/mmalloc.texi.
7480 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7481 'help info proc' for details.
7483 * MIPS ecoff symbol table format
7485 The code that reads MIPS symbol table format is now supported on all hosts.
7486 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7489 * File name changes for MS-DOS
7491 Many files in the config directories have been renamed to make it easier to
7492 support GDB on MS-DOSe systems (which have very restrictive file name
7493 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7494 environment) is close to working but has some remaining problems. Note
7495 that debugging of DOS programs is not supported, due to limitations
7496 in the ``operating system'', but it can be used to host cross-debugging.
7498 * Cross byte order fixes
7500 Many fixes have been made to support cross debugging of Sparc and MIPS
7501 targets from hosts whose byte order differs.
7503 * New -mapped and -readnow options
7505 If memory-mapped files are available on your system through the 'mmap'
7506 system call, you can use the -mapped option on the `file' or
7507 `symbol-file' commands to cause GDB to write the symbols from your
7508 program into a reusable file. If the program you are debugging is
7509 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7510 Future GDB debugging sessions will notice the presence of this file,
7511 and will quickly map in symbol information from it, rather than reading
7512 the symbol table from the executable program. Using the '-mapped'
7513 option in a GDB `file' or `symbol-file' command has the same effect as
7514 starting GDB with the '-mapped' command-line option.
7516 You can cause GDB to read the entire symbol table immediately by using
7517 the '-readnow' option with any of the commands that load symbol table
7518 information (or on the GDB command line). This makes the command
7519 slower, but makes future operations faster.
7521 The -mapped and -readnow options are typically combined in order to
7522 build a `fred.syms' file that contains complete symbol information.
7523 A simple GDB invocation to do nothing but build a `.syms' file for future
7526 gdb -batch -nx -mapped -readnow programname
7528 The `.syms' file is specific to the host machine on which GDB is run.
7529 It holds an exact image of GDB's internal symbol table. It cannot be
7530 shared across multiple host platforms.
7532 * longjmp() handling
7534 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7535 siglongjmp() without losing control. This feature has not yet been ported to
7536 all systems. It currently works on many 386 platforms, all MIPS-based
7537 platforms (SGI, DECstation, etc), and Sun3/4.
7541 Preliminary work has been put in to support the new Solaris OS from Sun. At
7542 this time, it can control and debug processes, but it is not capable of
7547 As always, many many bug fixes. The major areas were with g++, and mipsread.
7548 People using the MIPS-based platforms should experience fewer mysterious
7549 crashes and trashed symbol tables.
7551 *** Changes in GDB-4.4:
7553 * New machines supported (host and target)
7555 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7557 BSD Reno on Vax vax-dec-bsd
7558 Ultrix on Vax vax-dec-ultrix
7560 * New machines supported (target)
7562 AMD 29000 embedded, using EBMON a29k-none-none
7566 GDB continues to improve its handling of C++. `References' work better.
7567 The demangler has also been improved, and now deals with symbols mangled as
7568 per the Annotated C++ Reference Guide.
7570 GDB also now handles `stabs' symbol information embedded in MIPS
7571 `ecoff' symbol tables. Since the ecoff format was not easily
7572 extensible to handle new languages such as C++, this appeared to be a
7573 good way to put C++ debugging info into MIPS binaries. This option
7574 will be supported in the GNU C compiler, version 2, when it is
7577 * New features for SVR4
7579 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7580 shared libraries. Debugging dynamically linked programs should present
7581 only minor differences from debugging statically linked programs.
7583 The `info proc' command will print out information about any process
7584 on an SVR4 system (including the one you are debugging). At the moment,
7585 it prints the address mappings of the process.
7587 If you bring up GDB on another SVR4 system, please send mail to
7588 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7590 * Better dynamic linking support in SunOS
7592 Reading symbols from shared libraries which contain debugging symbols
7593 now works properly. However, there remain issues such as automatic
7594 skipping of `transfer vector' code during function calls, which
7595 make it harder to debug code in a shared library, than to debug the
7596 same code linked statically.
7600 GDB is now using the latest `getopt' routines from the FSF. This
7601 version accepts the -- prefix for options with long names. GDB will
7602 continue to accept the old forms (-option and +option) as well.
7603 Various single letter abbreviations for options have been explicity
7604 added to the option table so that they won't get overshadowed in the
7605 future by other options that begin with the same letter.
7609 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7610 Many assorted bugs have been handled. Many more remain to be handled.
7611 See the various ChangeLog files (primarily in gdb and bfd) for details.
7614 *** Changes in GDB-4.3:
7616 * New machines supported (host and target)
7618 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7619 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7620 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7622 * Almost SCO Unix support
7624 We had hoped to support:
7625 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7626 (except for core file support), but we discovered very late in the release
7627 that it has problems with process groups that render gdb unusable. Sorry
7628 about that. I encourage people to fix it and post the fixes.
7630 * Preliminary ELF and DWARF support
7632 GDB can read ELF object files on System V Release 4, and can handle
7633 debugging records for C, in DWARF format, in ELF files. This support
7634 is preliminary. If you bring up GDB on another SVR4 system, please
7635 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7640 GDB now uses the latest `readline' library. One user-visible change
7641 is that two tabs will list possible command completions, which previously
7642 required typing M-? (meta-question mark, or ESC ?).
7646 The `stepi' bug that many of you noticed has been squashed.
7647 Many bugs in C++ have been handled. Many more remain to be handled.
7648 See the various ChangeLog files (primarily in gdb and bfd) for details.
7650 * State of the MIPS world (in case you wondered):
7652 GDB can understand the symbol tables emitted by the compilers
7653 supplied by most vendors of MIPS-based machines, including DEC. These
7654 symbol tables are in a format that essentially nobody else uses.
7656 Some versions of gcc come with an assembler post-processor called
7657 mips-tfile. This program is required if you want to do source-level
7658 debugging of gcc-compiled programs. I believe FSF does not ship
7659 mips-tfile with gcc version 1, but it will eventually come with gcc
7662 Debugging of g++ output remains a problem. g++ version 1.xx does not
7663 really support it at all. (If you're lucky, you should be able to get
7664 line numbers and stack traces to work, but no parameters or local
7665 variables.) With some work it should be possible to improve the
7668 When gcc version 2 is released, you will have somewhat better luck.
7669 However, even then you will get confusing results for inheritance and
7672 We will eventually provide full debugging of g++ output on
7673 DECstations. This will probably involve some kind of stabs-in-ecoff
7674 encapulation, but the details have not been worked out yet.
7677 *** Changes in GDB-4.2:
7679 * Improved configuration
7681 Only one copy of `configure' exists now, and it is not self-modifying.
7682 Porting BFD is simpler.
7686 The `step' and `next' commands now only stop at the first instruction
7687 of a source line. This prevents the multiple stops that used to occur
7688 in switch statements, for-loops, etc. `Step' continues to stop if a
7689 function that has debugging information is called within the line.
7693 Lots of small bugs fixed. More remain.
7695 * New host supported (not target)
7697 Intel 386 PC clone running Mach i386-none-mach
7700 *** Changes in GDB-4.1:
7702 * Multiple source language support
7704 GDB now has internal scaffolding to handle several source languages.
7705 It determines the type of each source file from its filename extension,
7706 and will switch expression parsing and number formatting to match the
7707 language of the function in the currently selected stack frame.
7708 You can also specifically set the language to be used, with
7709 `set language c' or `set language modula-2'.
7713 GDB now has preliminary support for the GNU Modula-2 compiler,
7714 currently under development at the State University of New York at
7715 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7716 continue through the fall of 1991 and into 1992.
7718 Other Modula-2 compilers are currently not supported, and attempting to
7719 debug programs compiled with them will likely result in an error as the
7720 symbol table is read. Feel free to work on it, though!
7722 There are hooks in GDB for strict type checking and range checking,
7723 in the `Modula-2 philosophy', but they do not currently work.
7727 GDB can now write to executable and core files (e.g. patch
7728 a variable's value). You must turn this switch on, specify
7729 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7730 by assigning a new value to a variable. Modifications take
7733 * Automatic SunOS shared library reading
7735 When you run your program, GDB automatically determines where its
7736 shared libraries (if any) have been loaded, and reads their symbols.
7737 The `share' command is no longer needed. This also works when
7738 examining core files.
7742 You can specify the number of lines that the `list' command shows.
7745 * New machines supported (host and target)
7747 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7748 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7749 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7751 * New hosts supported (not targets)
7753 IBM RT/PC: romp-ibm-aix or rtpc
7755 * New targets supported (not hosts)
7757 AMD 29000 embedded with COFF a29k-none-coff
7758 AMD 29000 embedded with a.out a29k-none-aout
7759 Ultracomputer remote kernel debug a29k-nyu-kern
7761 * New remote interfaces
7767 *** Changes in GDB-4.0:
7771 Wide output is wrapped at good places to make the output more readable.
7773 Gdb now supports cross-debugging from a host machine of one type to a
7774 target machine of another type. Communication with the target system
7775 is over serial lines. The ``target'' command handles connecting to the
7776 remote system; the ``load'' command will download a program into the
7777 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7778 also supports debugging of realtime processes running under VxWorks,
7779 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7780 stub on the target system.
7782 New CPUs supported include the AMD 29000 and Intel 960.
7784 GDB now reads object files and symbol tables via a ``binary file''
7785 library, which allows a single copy of GDB to debug programs of multiple
7786 object file types such as a.out and coff.
7788 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7789 refcard.dvi and refcard.ps are available to format it).
7792 * Control-Variable user interface simplified
7794 All variables that control the operation of the debugger can be set
7795 by the ``set'' command, and displayed by the ``show'' command.
7797 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7798 ``Show prompt'' produces the response:
7799 Gdb's prompt is new-gdb=>.
7801 What follows are the NEW set commands. The command ``help set'' will
7802 print a complete list of old and new set commands. ``help set FOO''
7803 will give a longer description of the variable FOO. ``show'' will show
7804 all of the variable descriptions and their current settings.
7806 confirm on/off: Enables warning questions for operations that are
7807 hard to recover from, e.g. rerunning the program while
7808 it is already running. Default is ON.
7810 editing on/off: Enables EMACS style command line editing
7811 of input. Previous lines can be recalled with
7812 control-P, the current line can be edited with control-B,
7813 you can search for commands with control-R, etc.
7816 history filename NAME: NAME is where the gdb command history
7817 will be stored. The default is .gdb_history,
7818 or the value of the environment variable
7821 history size N: The size, in commands, of the command history. The
7822 default is 256, or the value of the environment variable
7825 history save on/off: If this value is set to ON, the history file will
7826 be saved after exiting gdb. If set to OFF, the
7827 file will not be saved. The default is OFF.
7829 history expansion on/off: If this value is set to ON, then csh-like
7830 history expansion will be performed on
7831 command line input. The default is OFF.
7833 radix N: Sets the default radix for input and output. It can be set
7834 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7835 in the current radix, so "set radix 10" is always a no-op.
7837 height N: This integer value is the number of lines on a page. Default
7838 is 24, the current `stty rows'' setting, or the ``li#''
7839 setting from the termcap entry matching the environment
7842 width N: This integer value is the number of characters on a line.
7843 Default is 80, the current `stty cols'' setting, or the ``co#''
7844 setting from the termcap entry matching the environment
7847 Note: ``set screensize'' is obsolete. Use ``set height'' and
7848 ``set width'' instead.
7850 print address on/off: Print memory addresses in various command displays,
7851 such as stack traces and structure values. Gdb looks
7852 more ``symbolic'' if you turn this off; it looks more
7853 ``machine level'' with it on. Default is ON.
7855 print array on/off: Prettyprint arrays. New convenient format! Default
7858 print demangle on/off: Print C++ symbols in "source" form if on,
7861 print asm-demangle on/off: Same, for assembler level printouts
7864 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7867 * Support for Epoch Environment.
7869 The epoch environment is a version of Emacs v18 with windowing. One
7870 new command, ``inspect'', is identical to ``print'', except that if you
7871 are running in the epoch environment, the value is printed in its own
7875 * Support for Shared Libraries
7877 GDB can now debug programs and core files that use SunOS shared libraries.
7878 Symbols from a shared library cannot be referenced
7879 before the shared library has been linked with the program (this
7880 happens after you type ``run'' and before the function main() is entered).
7881 At any time after this linking (including when examining core files
7882 from dynamically linked programs), gdb reads the symbols from each
7883 shared library when you type the ``sharedlibrary'' command.
7884 It can be abbreviated ``share''.
7886 sharedlibrary REGEXP: Load shared object library symbols for files
7887 matching a unix regular expression. No argument
7888 indicates to load symbols for all shared libraries.
7890 info sharedlibrary: Status of loaded shared libraries.
7895 A watchpoint stops execution of a program whenever the value of an
7896 expression changes. Checking for this slows down execution
7897 tremendously whenever you are in the scope of the expression, but is
7898 quite useful for catching tough ``bit-spreader'' or pointer misuse
7899 problems. Some machines such as the 386 have hardware for doing this
7900 more quickly, and future versions of gdb will use this hardware.
7902 watch EXP: Set a watchpoint (breakpoint) for an expression.
7904 info watchpoints: Information about your watchpoints.
7906 delete N: Deletes watchpoint number N (same as breakpoints).
7907 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7908 enable N: Re-enables watchpoint number N (same as breakpoints).
7911 * C++ multiple inheritance
7913 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7916 * C++ exception handling
7918 Gdb now supports limited C++ exception handling. Besides the existing
7919 ability to breakpoint on an exception handler, gdb can breakpoint on
7920 the raising of an exception (before the stack is peeled back to the
7923 catch FOO: If there is a FOO exception handler in the dynamic scope,
7924 set a breakpoint to catch exceptions which may be raised there.
7925 Multiple exceptions (``catch foo bar baz'') may be caught.
7927 info catch: Lists all exceptions which may be caught in the
7928 current stack frame.
7931 * Minor command changes
7933 The command ``call func (arg, arg, ...)'' now acts like the print
7934 command, except it does not print or save a value if the function's result
7935 is void. This is similar to dbx usage.
7937 The ``up'' and ``down'' commands now always print the frame they end up
7938 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7939 frames without printing.
7941 * New directory command
7943 'dir' now adds directories to the FRONT of the source search path.
7944 The path starts off empty. Source files that contain debug information
7945 about the directory in which they were compiled can be found even
7946 with an empty path; Sun CC and GCC include this information. If GDB can't
7947 find your source file in the current directory, type "dir .".
7949 * Configuring GDB for compilation
7951 For normal use, type ``./configure host''. See README or gdb.texinfo
7954 GDB now handles cross debugging. If you are remotely debugging between
7955 two different machines, type ``./configure host -target=targ''.
7956 Host is the machine where GDB will run; targ is the machine
7957 where the program that you are debugging will run.