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
18 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
19 and "org.gnu.gdb.arc.aux". The old names are still supported but
20 must be considered obsolete. They will be deprecated after some
23 * Help and apropos commands will now show the documentation of a
24 command only once, even if that command has one or more aliases.
25 These commands now show the command name, then all of its aliases,
26 and finally the description of the command.
28 * 'help aliases' now shows only the user defined aliases. GDB predefined
29 aliases are shown together with their aliased command.
31 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
32 debugging information as well as source code.
34 When built with debuginfod, GDB can automatically query debuginfod
35 servers for the separate debug files and source code of the executable
38 To build GDB with debuginfod, pass --with-debuginfod to configure (this
39 requires libdebuginfod, the debuginfod client library).
41 debuginfod is distributed with elfutils, starting with version 0.178.
43 You can get the latest version from https://sourceware.org/elfutils.
45 * Multi-target debugging support
47 GDB now supports debugging multiple target connections
48 simultaneously. For example, you can now have each inferior
49 connected to different remote servers running in different machines,
50 or have one inferior debugging a local native process, an inferior
51 debugging a core dump, etc.
53 This support is experimental and comes with some limitations -- you
54 can only resume multiple targets simultaneously if all targets
55 support non-stop mode, and all remote stubs or servers must support
56 the same set of remote protocol features exactly. See also "info
57 connections" and "add-inferior -no-connection" below, and "maint set
58 target-non-stop" in the user manual.
60 * New features in the GDB remote stub, GDBserver
62 ** GDBserver is now supported on RISC-V GNU/Linux.
64 ** GDBserver no longer supports these host triplets:
75 i[34567]86-*-mingw32ce*
77 * Debugging MS-Windows processes now sets $_exitsignal when the
78 inferior is terminated by a signal, instead of setting $_exitcode.
80 * Multithreaded symbol loading has now been enabled by default on systems
81 that support it (see entry for GDB 9, below), providing faster
82 performance for programs with many symbols.
84 * The $_siginfo convenience variable now also works on Windows targets,
85 and will display the EXCEPTION_RECORD of the last handled exception.
87 * TUI windows can now be arranged horizontally.
89 * The command history filename can now be set to the empty string
90 either using 'set history filename' or by setting 'GDBHISTFILE=' in
91 the environment. The effect of setting this filename to the empty
92 string is that GDB will not try to load any previous command
95 * On Windows targets, it is now possible to debug 32-bit programs with a
100 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
101 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
102 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
103 running process, this new option indicates whether to detect
104 a mismatch between the current executable file loaded by GDB and the
105 executable file used to start the process. If 'ask', the default,
106 display a warning and ask the user whether to load the process
107 executable file; if 'warn', just display a warning; if 'off', don't
108 attempt to detect a mismatch.
110 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
111 Define a new TUI layout, specifying its name and the windows that
114 maintenance print xml-tdesc [FILE]
115 Prints the current target description as an XML document. If the
116 optional FILE is provided (which is an XML target description) then
117 the target description is read from FILE into GDB, and then
120 maintenance print core-file-backed-mappings
121 Prints file-backed mappings loaded from a core file's note section.
122 Output is expected to be similar to that of "info proc mappings".
126 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
127 The alias command can now specify default args for an alias.
128 GDB automatically prepends the alias default args to the argument list
129 provided explicitly by the user.
130 For example, to have a backtrace with full details, you can define
132 'alias bt_ALL = backtrace -entry-values both -frame-arg all
133 -past-main -past-entry -full'.
134 Alias default arguments can also use a set of nested 'with' commands,
135 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
136 defines the alias pp10 that will pretty print a maximum of 10 elements
137 of the given expression (if the expression is an array).
141 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
146 ** gdb.register_window_type can be used to implement new TUI windows
149 ** Dynamic types can now be queried. gdb.Type has a new attribute,
150 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
151 field of a dynamic type may have None for its "bitpos" attribute
154 ** Commands written in Python can be in the "TUI" help class by
155 registering with the new constant gdb.COMMAND_TUI.
157 ** New method gdb.PendingFrame.architecture () to retrieve the
158 architecture of the pending frame.
160 ** New gdb.Architecture.registers method that returns a
161 gdb.RegisterDescriptorIterator object, an iterator that returns
162 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
163 way to query the registers available for an architecture.
165 ** New gdb.Architecture.register_groups method that returns a
166 gdb.RegisterGroupIterator object, an iterator that returns
167 gdb.RegisterGroup objects. The new RegisterGroup is a way to
168 discover the available register groups.
172 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
174 ** Procedures 'memory-port-read-buffer-size',
175 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
176 and 'set-memory-port-write-buffer-size!' are deprecated. When
177 using Guile 2.2 and later, users who need to control the size of
178 a memory port's internal buffer can use the 'setvbuf' procedure.
182 * 'thread-exited' event is now available in the annotations interface.
184 * New built-in convenience variables $_gdb_major and $_gdb_minor
185 provide the GDB version. They are handy for conditionally using
186 features available only in or since specific GDB versions, in
187 scripts that should work error-free with many different versions,
188 such as in system-wide init files.
190 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
191 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
192 of the GDB settings and the GDB maintenance settings. They are handy
193 for changing the logic of user defined commands depending on the
194 current GDB settings.
196 * GDB now supports Thread Local Storage (TLS) variables on several
197 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
198 architectures require kernel changes. TLS is not yet supported for
199 amd64 and i386 process core dumps.
201 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
202 addresses that required unmasking are shown in the backtrace with the
205 * Two new convenience functions $_cimag and $_creal that extract the
206 imaginary and real parts respectively from complex numbers.
208 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
209 provide the exitcode or exit status of the shell commands launched by
210 GDB commands such as "shell", "pipe" and "make".
212 * The command define-prefix can now define user defined prefix commands.
213 User defined commands can now be defined using these user defined prefix
216 * Command names can now use the . character.
218 * The RX port now supports XML target descriptions.
220 * GDB now shows the Ada task names at more places, e.g. in task switching
223 * GDB can now be compiled with Python 3 on Windows.
225 * New convenience variable $_ada_exception holds the address of the
226 Ada exception being thrown. This is set by Ada-related catchpoints.
228 * GDB can now place breakpoints on nested functions and subroutines in
229 Fortran code. The '::' operator can be used between parent and
230 child scopes when placing breakpoints, for example:
232 (gdb) break outer_function::inner_function
234 The 'outer_function::' prefix is only needed if 'inner_function' is
235 not visible in the current scope.
237 * In addition to the system-wide gdbinit file, if configured with
238 --with-system-gdbinit-dir, GDB will now also load files in that directory
239 as system gdbinit files, unless the -nx or -n flag is provided. Files
240 with extensions .gdb, .py and .scm are supported as long as GDB was
241 compiled with support for that language.
243 * GDB now supports multithreaded symbol loading for higher performance.
244 This feature is still in testing, so it is disabled by default. You
245 can turn it on using 'maint set worker-threads unlimited'.
249 ** The gdb.Value type has a new method 'format_string' which returns a
250 string representing the value. The formatting is controlled by the
251 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
252 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
253 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
255 ** gdb.Type has a new property 'objfile' which returns the objfile the
258 ** The frame information printed by the python frame filtering code
259 is now consistent with what the 'backtrace' command prints when
260 there are no filters, or when the 'backtrace' '-no-filters' option
263 ** The new function gdb.lookup_static_symbol can be used to look up
264 symbols with static linkage.
266 ** The new function gdb.lookup_static_symbols can be used to look up
267 all static symbols with static linkage.
269 ** gdb.Objfile has new methods 'lookup_global_symbol' and
270 'lookup_static_symbol' to lookup a symbol from this objfile only.
272 ** gdb.Block now supports the dictionary syntax for accessing symbols in
273 this block (e.g. block['local_variable']).
277 | [COMMAND] | SHELL_COMMAND
278 | -d DELIM COMMAND DELIM SHELL_COMMAND
279 pipe [COMMAND] | SHELL_COMMAND
280 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
281 Executes COMMAND and sends its output to SHELL_COMMAND.
282 With no COMMAND, repeat the last executed command
283 and send its output to SHELL_COMMAND.
285 define-prefix COMMAND
286 Define or mark a command as a user-defined prefix command.
288 with SETTING [VALUE] [-- COMMAND]
289 w SETTING [VALUE] [-- COMMAND]
290 Temporarily set SETTING, run COMMAND, and restore SETTING.
291 Usage: with SETTING -- COMMAND
292 With no COMMAND, repeats the last executed command.
293 SETTING is any GDB setting you can change with the "set"
294 subcommands. For example, 'with language c -- print someobj'
295 temporarily switches to the C language in order to print someobj.
296 Settings can be combined: 'w lang c -- w print elements unlimited --
297 usercmd' switches to the C language and runs usercmd with no limit
298 of array elements to print.
300 maint with SETTING [VALUE] [-- COMMAND]
301 Like "with", but works with "maintenance set" settings.
303 set may-call-functions [on|off]
304 show may-call-functions
305 This controls whether GDB will attempt to call functions in
306 the program, such as with expressions in the print command. It
307 defaults to on. Calling functions in the program being debugged
308 can have undesired side effects. It is now possible to forbid
309 such function calls. If function calls are forbidden, GDB will throw
310 an error when a command (such as print expression) calls a function
313 set print finish [on|off]
315 This controls whether the `finish' command will display the value
316 that is returned by the current function. When `off', the value is
317 still entered into the value history, but it is not printed. The
322 Allows deeply nested structures to be simplified when printing by
323 replacing deeply nested parts (beyond the max-depth) with ellipses.
324 The default max-depth is 20, but this can be set to unlimited to get
325 the old behavior back.
327 set print raw-values [on|off]
328 show print raw-values
329 By default, GDB applies the enabled pretty printers when printing a
330 value. This allows to ignore the enabled pretty printers for a series
331 of commands. The default is 'off'.
333 set logging debugredirect [on|off]
334 By default, GDB debug output will go to both the terminal and the logfile.
335 Set if you want debug output to go only to the log file.
337 set style title foreground COLOR
338 set style title background COLOR
339 set style title intensity VALUE
340 Control the styling of titles.
342 set style highlight foreground COLOR
343 set style highlight background COLOR
344 set style highlight intensity VALUE
345 Control the styling of highlightings.
347 maint set worker-threads
348 maint show worker-threads
349 Control the number of worker threads that can be used by GDB. The
350 default is 0. "unlimited" lets GDB choose a number that is
351 reasonable. Currently worker threads are only used when demangling
352 the names of linker symbols.
354 set style tui-border foreground COLOR
355 set style tui-border background COLOR
356 Control the styling of TUI borders.
358 set style tui-active-border foreground COLOR
359 set style tui-active-border background COLOR
360 Control the styling of the active TUI border.
362 maint set test-settings KIND
363 maint show test-settings KIND
364 A set of commands used by the testsuite for exercising the settings
367 maint set tui-resize-message [on|off]
368 maint show tui-resize-message
369 Control whether GDB prints a message each time the terminal is
370 resized when in TUI mode. This is primarily useful for testing the
373 set print frame-info [short-location|location|location-and-address
374 |source-and-location|source-line|auto]
375 show print frame-info
376 This controls what frame information is printed by the commands printing
377 a frame. This setting will e.g. influence the behaviour of 'backtrace',
378 'frame', 'stepi'. The python frame filtering also respect this setting.
379 The 'backtrace' '-frame-info' option can override this global setting.
381 set tui compact-source
382 show tui compact-source
384 Enable the "compact" display mode for the TUI source window. The
385 compact display uses only as much space as is needed for the line
386 numbers in the current file, and only a single space to separate the
387 line numbers from the source.
389 info modules [-q] [REGEXP]
390 Return a list of Fortran modules matching REGEXP, or all modules if
393 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
394 Return a list of functions within all modules, grouped by module.
395 The list of functions can be restricted with the optional regular
396 expressions. MODULE_REGEXP matches against the module name,
397 TYPE_REGEXP matches against the function type signature, and REGEXP
398 matches against the function name.
400 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
401 Return a list of variables within all modules, grouped by module.
402 The list of variables can be restricted with the optional regular
403 expressions. MODULE_REGEXP matches against the module name,
404 TYPE_REGEXP matches against the variable type, and REGEXP matches
405 against the variable name.
407 set debug remote-packet-max-chars
408 show debug remote-packet-max-chars
409 Controls the number of characters to output in a remote packet when using
411 The default is 512 bytes.
414 Lists the target connections currently in use.
419 The "help" command uses the title style to enhance the
420 readibility of its output by styling the classes and
424 Similarly to "help", the "apropos" command also uses the
425 title style for the command names. "apropos" accepts now
426 a flag "-v" (verbose) to show the full documentation
427 of matching commands and to use the highlight style to mark
428 the documentation parts matching REGEXP.
432 The GDB printf and eval commands can now print C-style and Ada-style
433 string convenience variables without calling functions in the program.
434 This allows to do formatted printing of strings without having
435 a running inferior, or when debugging a core dump.
437 info sources [-dirname | -basename] [--] [REGEXP]
438 This command has now optional arguments to only print the files
439 whose names match REGEXP. The arguments -dirname and -basename
440 allow to restrict matching respectively to the dirname and basename
444 The "show style" and its subcommands are now styling
445 a style name in their output using its own style, to help
446 the user visualize the different styles.
448 set print frame-arguments
449 The new value 'presence' indicates to only indicate the presence of
450 arguments using ..., instead of printing argument names and values.
452 set print raw-frame-arguments
453 show print raw-frame-arguments
455 These commands replace the similarly-named "set/show print raw
456 frame-arguments" commands (now with a dash instead of a space). The
457 old commands are now deprecated and may be removed in a future
460 add-inferior [-no-connection]
461 The add-inferior command now supports a "-no-connection" flag that
462 makes the new inferior start with no target connection associated.
463 By default, the new inferior inherits the target connection of the
464 current inferior. See also "info connections".
467 This command's output now includes a new "Connection" column
468 indicating which target connection an inferior is bound to. See
469 "info connections" above.
471 maint test-options require-delimiter
472 maint test-options unknown-is-error
473 maint test-options unknown-is-operand
474 maint show test-options-completion-result
475 Commands used by the testsuite to validate the command options
478 focus, winheight, +, -, >, <
479 These commands are now case-sensitive.
481 * New command options, command completion
483 GDB now has a standard infrastructure to support dash-style command
484 options ('-OPT'). One benefit is that commands that use it can
485 easily support completion of command line arguments. Try "CMD
486 -[TAB]" or "help CMD" to find options supported by a command. Over
487 time, we intend to migrate most commands to this infrastructure. A
488 number of commands got support for new command options in this
491 ** The "print" and "compile print" commands now support a number of
492 options that allow overriding relevant global print settings as
493 set by "set print" subcommands:
497 -array-indexes [on|off]
498 -elements NUMBER|unlimited
503 -repeats NUMBER|unlimited
504 -static-members [on|off]
509 Note that because the "print"/"compile print" commands accept
510 arbitrary expressions which may look like options (including
511 abbreviations), if you specify any command option, then you must
512 use a double dash ("--") to mark the end of argument processing.
514 ** The "backtrace" command now supports a number of options that
515 allow overriding relevant global print settings as set by "set
516 backtrace" and "set print" subcommands:
518 -entry-values no|only|preferred|if-needed|both|compact|default
519 -frame-arguments all|scalars|none
520 -raw-frame-arguments [on|off]
521 -frame-info auto|source-line|location|source-and-location
522 |location-and-address|short-location
526 In addition, the full/no-filters/hide qualifiers are now also
527 exposed as command options too:
533 ** The "frame apply", "tfaas" and "faas" commands similarly now
534 support the following options:
539 ** The new "info sources" options -dirname and -basename options
540 are using the standard '-OPT' infrastructure.
542 All options above can also be abbreviated. The argument of boolean
543 (on/off) options can be 0/1 too, and also the argument is assumed
544 "on" if omitted. This allows writing compact command invocations,
547 (gdb) p -ra -p -o 0 -- *myptr
549 The above is equivalent to:
551 (gdb) print -raw-values -pretty -object off -- *myptr
553 ** The "info types" command now supports the '-q' flag to disable
554 printing of some header information in a similar fashion to "info
555 variables" and "info functions".
557 ** The "info variables", "info functions", and "whereis" commands
558 now take a '-n' flag that excludes non-debug symbols (symbols
559 from the symbol table, not from the debug info such as DWARF)
562 * Completion improvements
564 ** GDB can now complete the options of the "thread apply all" and
565 "taas" commands, and their "-ascending" option can now be
568 ** GDB can now complete the options of the "info threads", "info
569 functions", "info variables", "info locals", and "info args"
572 ** GDB can now complete the options of the "compile file" and
573 "compile code" commands. The "compile file" command now
574 completes on filenames.
576 ** GDB can now complete the backtrace command's
577 "full/no-filters/hide" qualifiers.
579 * In settings, you can now abbreviate "unlimited".
581 E.g., "set print elements u" is now equivalent to "set print
587 This lists all the possible completions for the rest of the line, if it
588 were to be given as a command itself. This is intended for use by MI
589 frontends in cases when separate CLI and MI channels cannot be used.
591 -catch-throw, -catch-rethrow, and -catch-catch
592 These can be used to catch C++ exceptions in a similar fashion to
593 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
595 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
596 These commands are the MI equivalent of the CLI commands 'info
597 functions', 'info types', and 'info variables' respectively.
599 -symbol-info-modules, this is the MI equivalent of the CLI 'info
602 -symbol-info-module-functions and -symbol-info-module-variables.
603 These commands are the MI equivalent of the CLI commands 'info
604 module functions' and 'info module variables'.
608 ** The default version of the MI interpreter is now 3 (-i=mi3).
610 ** The output of information about multi-location breakpoints (which is
611 syntactically incorrect in MI 2) has changed in MI 3. This affects
612 the following commands and events:
616 - =breakpoint-created
617 - =breakpoint-modified
619 The -fix-multi-location-breakpoint-output command can be used to enable
620 this behavior with previous MI versions.
622 ** Backtraces and frames include a new optional field addr_flags which is
623 given after the addr field. On AArch64 this contains PAC if the address
624 has been masked in the frame. On all other targets the field is not
629 The testsuite now creates the files gdb.cmd (containing the arguments
630 used to launch GDB) and gdb.in (containing all the commands sent to
631 GDB) in the output directory for each test script. Multiple invocations
632 are appended with .1, .2, .3 etc.
634 * Building GDB and GDBserver now requires GNU make >= 3.82.
636 Using another implementation of the make program or an earlier version of
637 GNU make to build GDB or GDBserver is not supported.
639 * Building GDB now requires GNU readline >= 7.0.
641 GDB now bundles GNU readline 8.0, but if you choose to use
642 --with-system-readline, only readline >= 7.0 can be used.
644 * The TUI SingleKey keymap is now named "SingleKey". This can be used
645 from .inputrc to bind keys in this keymap. This feature is only
646 available when gdb is built against GNU readline 8.0 or later.
648 * Removed targets and native configurations
650 GDB no longer supports debugging the Cell Broadband Engine. This includes
651 both debugging standalone Cell/B.E. SPU applications and integrated debugging
652 of Cell/B.E. applications that use both the PPU and SPU architectures.
658 * Removed targets and native configurations
660 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
663 *** Changes in GDB 8.3
665 * GDB and GDBserver now support access to additional registers on
666 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
669 * GDB now has experimental support for the compilation and injection of
670 C++ source code into the inferior. This beta release does not include
671 support for several language features, such as templates, constructors,
674 This feature requires GCC 7.1 or higher built with libcp1.so
677 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
678 can be passed using the '[ADDRESS]:PORT' notation, or the regular
679 'ADDRESS:PORT' method.
681 * DWARF index cache: GDB can now automatically save indices of DWARF
682 symbols on disk to speed up further loading of the same binaries.
684 * Ada task switching is now supported on aarch64-elf targets when
685 debugging a program using the Ravenscar Profile. For more information,
686 see the "Tasking Support when using the Ravenscar Profile" section
687 in the GDB user manual.
689 * GDB in batch mode now exits with status 1 if the last command to be
692 * The RISC-V target now supports target descriptions.
694 * System call catchpoints now support system call aliases on FreeBSD.
695 When the ABI of a system call changes in FreeBSD, this is
696 implemented by leaving a compatibility system call using the old ABI
697 at the existing number and allocating a new system call number for
698 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
699 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
700 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
701 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
702 so that a system call catchpoint for the 'kevent' system call will
703 catch invocations of both the 'kevent' and 'freebsd11_kevent'
704 binaries. This ensures that 'kevent' system calls are caught for
705 binaries using either the old or new ABIs.
707 * Terminal styling is now available for the CLI and the TUI. GNU
708 Source Highlight can additionally be used to provide styling of
709 source code snippets. See the "set style" commands, below, for more
712 * Removed support for old demangling styles arm, edg, gnu, hp and
717 set debug compile-cplus-types
718 show debug compile-cplus-types
719 Control the display of debug output about type conversion in the
720 C++ compile feature. Commands have no effect while compiling
725 Control whether debug output about files/functions skipping is
728 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
729 Apply a command to some frames.
730 FLAG arguments allow to control what output to produce and how to handle
731 errors raised when applying COMMAND to a frame.
734 Apply a command to all threads (ignoring errors and empty output).
735 Shortcut for 'thread apply all -s COMMAND'.
738 Apply a command to all frames (ignoring errors and empty output).
739 Shortcut for 'frame apply all -s COMMAND'.
742 Apply a command to all frames of all threads (ignoring errors and empty
744 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
746 maint set dwarf unwinders (on|off)
747 maint show dwarf unwinders
748 Control whether DWARF unwinders can be used.
751 Display a list of open files for a process.
755 Changes to the "frame", "select-frame", and "info frame" CLI commands.
756 These commands all now take a frame specification which
757 is either a frame level, or one of the keywords 'level', 'address',
758 'function', or 'view' followed by a parameter. Selecting a frame by
759 address, or viewing a frame outside the current backtrace now
760 requires the use of a keyword. Selecting a frame by level is
761 unchanged. The MI comment "-stack-select-frame" is unchanged.
763 target remote FILENAME
764 target extended-remote FILENAME
765 If FILENAME is a Unix domain socket, GDB will attempt to connect
766 to this socket instead of opening FILENAME as a character device.
768 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
769 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
770 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
771 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
772 These commands can now print only the searched entities
773 matching the provided regexp(s), giving a condition
774 on the entity names or entity types. The flag -q disables
775 printing headers or informations messages.
781 These commands now determine the syntax for the shown entities
782 according to the language chosen by `set language'. In particular,
783 `set language auto' means to automatically choose the language of
786 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
787 The 'thread apply' command accepts new FLAG arguments.
788 FLAG arguments allow to control what output to produce and how to handle
789 errors raised when applying COMMAND to a thread.
791 set tui tab-width NCHARS
792 show tui tab-width NCHARS
793 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
795 set style enabled [on|off]
797 Enable or disable terminal styling. Styling is enabled by default
798 on most hosts, but disabled by default when in batch mode.
800 set style sources [on|off]
802 Enable or disable source code styling. Source code styling is
803 enabled by default, but only takes effect if styling in general is
804 enabled, and if GDB was linked with GNU Source Highlight.
806 set style filename foreground COLOR
807 set style filename background COLOR
808 set style filename intensity VALUE
809 Control the styling of file names.
811 set style function foreground COLOR
812 set style function background COLOR
813 set style function intensity VALUE
814 Control the styling of function names.
816 set style variable foreground COLOR
817 set style variable background COLOR
818 set style variable intensity VALUE
819 Control the styling of variable names.
821 set style address foreground COLOR
822 set style address background COLOR
823 set style address intensity VALUE
824 Control the styling of addresses.
828 ** The '-data-disassemble' MI command now accepts an '-a' option to
829 disassemble the whole function surrounding the given program
830 counter value or function name. Support for this feature can be
831 verified by using the "-list-features" command, which should
832 contain "data-disassemble-a-option".
834 ** Command responses and notifications that include a frame now include
835 the frame's architecture in a new "arch" attribute.
837 * New native configurations
839 GNU/Linux/RISC-V riscv*-*-linux*
840 FreeBSD/riscv riscv*-*-freebsd*
844 GNU/Linux/RISC-V riscv*-*-linux*
846 CSKY GNU/LINUX csky*-*-linux
847 FreeBSD/riscv riscv*-*-freebsd*
849 GNU/Linux/OpenRISC or1k*-*-linux*
853 GDB no longer supports native debugging on versions of MS-Windows
858 ** GDB no longer supports Python versions less than 2.6.
860 ** The gdb.Inferior type has a new 'progspace' property, which is the program
861 space associated to that inferior.
863 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
864 of objfiles associated to that program space.
866 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
867 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
870 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
871 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
872 correct and did not work properly.
874 ** The gdb.Value type has a new constructor, which is used to construct a
875 gdb.Value from a Python buffer object and a gdb.Type.
881 Enable or disable the undefined behavior sanitizer. This is
882 disabled by default, but passing --enable-ubsan=yes or
883 --enable-ubsan=auto to configure will enable it. Enabling this can
884 cause a performance penalty. The undefined behavior sanitizer was
885 first introduced in GCC 4.9.
887 *** Changes in GDB 8.2
889 * The 'set disassembler-options' command now supports specifying options
892 * The 'symbol-file' command now accepts an '-o' option to add a relative
893 offset to all sections.
895 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
896 a relative offset to all sections, but it allows to override the load
897 address of individual sections using '-s'.
899 * The 'add-symbol-file' command no longer requires the second argument
900 (address of the text section).
902 * The endianness used with the 'set endian auto' mode in the absence of
903 an executable selected for debugging is now the last endianness chosen
904 either by one of the 'set endian big' and 'set endian little' commands
905 or by inferring from the last executable used, rather than the startup
908 * The pager now allows a "c" response, meaning to disable the pager
909 for the rest of the current command.
911 * The commands 'info variables/functions/types' now show the source line
912 numbers of symbol definitions when available.
914 * 'info proc' now works on running processes on FreeBSD systems and core
915 files created on FreeBSD systems.
917 * C expressions can now use _Alignof, and C++ expressions can now use
920 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
921 the vector length while the process is running.
927 Control display of debugging info regarding the FreeBSD native target.
929 set|show varsize-limit
930 This new setting allows the user to control the maximum size of Ada
931 objects being printed when those objects have a variable type,
932 instead of that maximum size being hardcoded to 65536 bytes.
934 set|show record btrace cpu
935 Controls the processor to be used for enabling errata workarounds for
938 maint check libthread-db
939 Run integrity checks on the current inferior's thread debugging
942 maint set check-libthread-db (on|off)
943 maint show check-libthread-db
944 Control whether to run integrity checks on inferior specific thread
945 debugging libraries as they are loaded. The default is not to
950 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
952 ** The commands attached to a breakpoint can be set by assigning to
953 the breakpoint's "commands" field.
955 ** gdb.execute can now execute multi-line gdb commands.
957 ** The new functions gdb.convenience_variable and
958 gdb.set_convenience_variable can be used to get and set the value
959 of convenience variables.
961 ** A gdb.Parameter will no longer print the "set" help text on an
962 ordinary "set"; instead by default a "set" will be silent unless
963 the get_set_string method returns a non-empty string.
967 RiscV ELF riscv*-*-elf
969 * Removed targets and native configurations
971 m88k running OpenBSD m88*-*-openbsd*
972 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
973 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
974 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
976 * Aarch64/Linux hardware watchpoints improvements
978 Hardware watchpoints on unaligned addresses are now properly
979 supported when running Linux kernel 4.10 or higher: read and access
980 watchpoints are no longer spuriously missed, and all watchpoints
981 lengths between 1 and 8 bytes are supported. On older kernels,
982 watchpoints set on unaligned addresses are no longer missed, with
983 the tradeoff that there is a possibility of false hits being
988 --enable-codesign=CERT
989 This can be used to invoke "codesign -s CERT" after building gdb.
990 This option is useful on macOS, where code signing is required for
991 gdb to work properly.
993 --disable-gdbcli has been removed
994 This is now silently accepted, but does nothing.
996 *** Changes in GDB 8.1
998 * GDB now supports dynamically creating arbitrary register groups specified
999 in XML target descriptions. This allows for finer grain grouping of
1000 registers on systems with a large amount of registers.
1002 * The 'ptype' command now accepts a '/o' flag, which prints the
1003 offsets and sizes of fields in a struct, like the pahole(1) tool.
1005 * New "--readnever" command line option instructs GDB to not read each
1006 symbol file's symbolic debug information. This makes startup faster
1007 but at the expense of not being able to perform symbolic debugging.
1008 This option is intended for use cases where symbolic debugging will
1009 not be used, e.g., when you only need to dump the debuggee's core.
1011 * GDB now uses the GNU MPFR library, if available, to emulate target
1012 floating-point arithmetic during expression evaluation when the target
1013 uses different floating-point formats than the host. At least version
1014 3.1 of GNU MPFR is required.
1016 * GDB now supports access to the guarded-storage-control registers and the
1017 software-based guarded-storage broadcast control registers on IBM z14.
1019 * On Unix systems, GDB now supports transmitting environment variables
1020 that are to be set or unset to GDBserver. These variables will
1021 affect the environment to be passed to the remote inferior.
1023 To inform GDB of environment variables that are to be transmitted to
1024 GDBserver, use the "set environment" command. Only user set
1025 environment variables are sent to GDBserver.
1027 To inform GDB of environment variables that are to be unset before
1028 the remote inferior is started by the GDBserver, use the "unset
1029 environment" command.
1031 * Completion improvements
1033 ** GDB can now complete function parameters in linespecs and
1034 explicit locations without quoting. When setting breakpoints,
1035 quoting around functions names to help with TAB-completion is
1036 generally no longer necessary. For example, this now completes
1039 (gdb) b function(in[TAB]
1040 (gdb) b function(int)
1042 Related, GDB is no longer confused with completing functions in
1043 C++ anonymous namespaces:
1046 (gdb) b (anonymous namespace)::[TAB][TAB]
1047 (anonymous namespace)::a_function()
1048 (anonymous namespace)::b_function()
1050 ** GDB now has much improved linespec and explicit locations TAB
1051 completion support, that better understands what you're
1052 completing and offers better suggestions. For example, GDB no
1053 longer offers data symbols as possible completions when you're
1054 setting a breakpoint.
1056 ** GDB now TAB-completes label symbol names.
1058 ** The "complete" command now mimics TAB completion accurately.
1060 * New command line options (gcore)
1063 Dump all memory mappings.
1065 * Breakpoints on C++ functions are now set on all scopes by default
1067 By default, breakpoints on functions/methods are now interpreted as
1068 specifying all functions with the given name ignoring missing
1069 leading scopes (namespaces and classes).
1071 For example, assuming a C++ program with symbols named:
1076 both commands "break func()" and "break B::func()" set a breakpoint
1079 You can use the new flag "-qualified" to override this. This makes
1080 GDB interpret the specified function name as a complete
1081 fully-qualified name instead. For example, using the same C++
1082 program, the "break -q B::func" command sets a breakpoint on
1083 "B::func", only. A parameter has been added to the Python
1084 gdb.Breakpoint constructor to achieve the same result when creating
1085 a breakpoint from Python.
1087 * Breakpoints on functions marked with C++ ABI tags
1089 GDB can now set breakpoints on functions marked with C++ ABI tags
1090 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1091 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1093 Functions with a C++11 abi tag are demangled/displayed like this:
1095 function[abi:cxx11](int)
1098 You can now set a breakpoint on such functions simply as if they had
1101 (gdb) b function(int)
1103 Or if you need to disambiguate between tags, like:
1105 (gdb) b function[abi:other_tag](int)
1107 Tab completion was adjusted accordingly as well.
1111 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1112 gdb.new_thread are emitted. See the manual for further
1113 description of these.
1115 ** A new function, "gdb.rbreak" has been added to the Python API.
1116 This function allows the setting of a large number of breakpoints
1117 via a regex pattern in Python. See the manual for further details.
1119 ** Python breakpoints can now accept explicit locations. See the
1120 manual for a further description of this feature.
1123 * New features in the GDB remote stub, GDBserver
1125 ** GDBserver is now able to start inferior processes with a
1126 specified initial working directory.
1128 The user can set the desired working directory to be used from
1129 GDB using the new "set cwd" command.
1131 ** New "--selftest" command line option runs some GDBserver self
1132 tests. These self tests are disabled in releases.
1134 ** On Unix systems, GDBserver now does globbing expansion and variable
1135 substitution in inferior command line arguments.
1137 This is done by starting inferiors using a shell, like GDB does.
1138 See "set startup-with-shell" in the user manual for how to disable
1139 this from GDB when using "target extended-remote". When using
1140 "target remote", you can disable the startup with shell by using the
1141 new "--no-startup-with-shell" GDBserver command line option.
1143 ** On Unix systems, GDBserver now supports receiving environment
1144 variables that are to be set or unset from GDB. These variables
1145 will affect the environment to be passed to the inferior.
1147 * When catching an Ada exception raised with a message, GDB now prints
1148 the message in the catchpoint hit notification. In GDB/MI mode, that
1149 information is provided as an extra field named "exception-message"
1150 in the *stopped notification.
1152 * Trait objects can now be inspected When debugging Rust code. This
1153 requires compiler support which will appear in Rust 1.24.
1155 * New remote packets
1157 QEnvironmentHexEncoded
1158 Inform GDBserver of an environment variable that is to be passed to
1159 the inferior when starting it.
1162 Inform GDBserver of an environment variable that is to be unset
1163 before starting the remote inferior.
1166 Inform GDBserver that the environment should be reset (i.e.,
1167 user-set environment variables should be unset).
1170 Indicates whether the inferior must be started with a shell or not.
1173 Tell GDBserver that the inferior to be started should use a specific
1176 * The "maintenance print c-tdesc" command now takes an optional
1177 argument which is the file name of XML target description.
1179 * The "maintenance selftest" command now takes an optional argument to
1180 filter the tests to be run.
1182 * The "enable", and "disable" commands now accept a range of
1183 breakpoint locations, e.g. "enable 1.3-5".
1188 Set and show the current working directory for the inferior.
1190 set|show compile-gcc
1191 Set and show compilation command used for compiling and injecting code
1192 with the 'compile' commands.
1194 set debug separate-debug-file
1195 show debug separate-debug-file
1196 Control the display of debug output about separate debug file search.
1198 set dump-excluded-mappings
1199 show dump-excluded-mappings
1200 Control whether mappings marked with the VM_DONTDUMP flag should be
1201 dumped when generating a core file.
1203 maint info selftests
1204 List the registered selftests.
1207 Start the debugged program stopping at the first instruction.
1210 Control display of debugging messages related to OpenRISC targets.
1212 set|show print type nested-type-limit
1213 Set and show the limit of nesting level for nested types that the
1214 type printer will show.
1216 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1219 * Safer/improved support for debugging with no debug info
1221 GDB no longer assumes functions with no debug information return
1224 This means that GDB now refuses to call such functions unless you
1225 tell it the function's type, by either casting the call to the
1226 declared return type, or by casting the function to a function
1227 pointer of the right type, and calling that:
1229 (gdb) p getenv ("PATH")
1230 'getenv' has unknown return type; cast the call to its declared return type
1231 (gdb) p (char *) getenv ("PATH")
1232 $1 = 0x7fffffffe "/usr/local/bin:/"...
1233 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1234 $2 = 0x7fffffffe "/usr/local/bin:/"...
1236 Similarly, GDB no longer assumes that global variables with no debug
1237 info have type 'int', and refuses to print the variable's value
1238 unless you tell it the variable's type:
1241 'var' has unknown type; cast it to its declared type
1245 * New native configurations
1247 FreeBSD/aarch64 aarch64*-*-freebsd*
1248 FreeBSD/arm arm*-*-freebsd*
1252 FreeBSD/aarch64 aarch64*-*-freebsd*
1253 FreeBSD/arm arm*-*-freebsd*
1254 OpenRISC ELF or1k*-*-elf
1256 * Removed targets and native configurations
1258 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1260 *** Changes in GDB 8.0
1262 * GDB now supports access to the PKU register on GNU/Linux. The register is
1263 added by the Memory Protection Keys for Userspace feature which will be
1264 available in future Intel CPUs.
1266 * GDB now supports C++11 rvalue references.
1270 ** New functions to start, stop and access a running btrace recording.
1271 ** Rvalue references are now supported in gdb.Type.
1273 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1276 * Building GDB and GDBserver now requires a C++11 compiler.
1278 For example, GCC 4.8 or later.
1280 It is no longer possible to build GDB or GDBserver with a C
1281 compiler. The --disable-build-with-cxx configure option has been
1284 * Building GDB and GDBserver now requires GNU make >= 3.81.
1286 It is no longer supported to build GDB or GDBserver with another
1287 implementation of the make program or an earlier version of GNU make.
1289 * Native debugging on MS-Windows supports command-line redirection
1291 Command-line arguments used for starting programs on MS-Windows can
1292 now include redirection symbols supported by native Windows shells,
1293 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1294 as "run", "start", and "set args", as well as the corresponding MI
1297 * Support for thread names on MS-Windows.
1299 GDB now catches and handles the special exception that programs
1300 running on MS-Windows use to assign names to threads in the
1303 * Support for Java programs compiled with gcj has been removed.
1305 * User commands now accept an unlimited number of arguments.
1306 Previously, only up to 10 was accepted.
1308 * The "eval" command now expands user-defined command arguments.
1310 This makes it easier to process a variable number of arguments:
1315 eval "print $arg%d", $i
1320 * Target descriptions can now describe registers for sparc32 and sparc64.
1322 * GDB now supports DWARF version 5 (debug information format).
1323 Its .debug_names index is not yet supported.
1325 * New native configurations
1327 FreeBSD/mips mips*-*-freebsd
1331 Synopsys ARC arc*-*-elf32
1332 FreeBSD/mips mips*-*-freebsd
1334 * Removed targets and native configurations
1336 Alpha running FreeBSD alpha*-*-freebsd*
1337 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1342 Erases all the flash memory regions reported by the target.
1344 maint print arc arc-instruction address
1345 Print internal disassembler information about instruction at a given address.
1349 set disassembler-options
1350 show disassembler-options
1351 Controls the passing of target specific information to the disassembler.
1352 If it is necessary to specify more than one disassembler option then
1353 multiple options can be placed together into a comma separated list.
1354 The default value is the empty string. Currently, the only supported
1355 targets are ARM, PowerPC and S/390.
1360 Erases all the flash memory regions reported by the target. This is
1361 equivalent to the CLI command flash-erase.
1363 -file-list-shared-libraries
1364 List the shared libraries in the program. This is
1365 equivalent to the CLI command "info shared".
1368 Catchpoints stopping the program when Ada exceptions are
1369 handled. This is equivalent to the CLI command "catch handlers".
1371 *** Changes in GDB 7.12
1373 * GDB and GDBserver now build with a C++ compiler by default.
1375 The --enable-build-with-cxx configure option is now enabled by
1376 default. One must now explicitly configure with
1377 --disable-build-with-cxx in order to build with a C compiler. This
1378 option will be removed in a future release.
1380 * GDBserver now supports recording btrace without maintaining an active
1383 * GDB now supports a negative repeat count in the 'x' command to examine
1384 memory backward from the given address. For example:
1387 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1388 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1389 (gdb) x/-5i 0x0000000000400580
1390 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1391 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1392 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1393 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1394 0x40057b <main(int, char**)+25>:
1395 callq 0x400536 <Func1(int, char const*)>
1397 * Fortran: Support structures with fields of dynamic types and
1398 arrays of dynamic types.
1400 * The symbol dumping maintenance commands have new syntax.
1401 maint print symbols [-pc address] [--] [filename]
1402 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1403 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1404 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1405 maint print msymbols [-objfile objfile] [--] [filename]
1407 * GDB now supports multibit bitfields and enums in target register
1410 * New Python-based convenience function $_as_string(val), which returns
1411 the textual representation of a value. This function is especially
1412 useful to obtain the text label of an enum value.
1414 * Intel MPX bound violation handling.
1416 Segmentation faults caused by a Intel MPX boundary violation
1417 now display the kind of violation (upper or lower), the memory
1418 address accessed and the memory bounds, along with the usual
1419 signal received and code location.
1423 Program received signal SIGSEGV, Segmentation fault
1424 Upper bound violation while accessing address 0x7fffffffc3b3
1425 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1426 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1428 * Rust language support.
1429 GDB now supports debugging programs written in the Rust programming
1430 language. See https://www.rust-lang.org/ for more information about
1433 * Support for running interpreters on specified input/output devices
1435 GDB now supports a new mechanism that allows frontends to provide
1436 fully featured GDB console views, as a better alternative to
1437 building such views on top of the "-interpreter-exec console"
1438 command. See the new "new-ui" command below. With that command,
1439 frontends can now start GDB in the traditional command-line mode
1440 running in an embedded terminal emulator widget, and create a
1441 separate MI interpreter running on a specified i/o device. In this
1442 way, GDB handles line editing, history, tab completion, etc. in the
1443 console all by itself, and the GUI uses the separate MI interpreter
1444 for its own control and synchronization, invisible to the command
1447 * The "catch syscall" command catches groups of related syscalls.
1449 The "catch syscall" command now supports catching a group of related
1450 syscalls using the 'group:' or 'g:' prefix.
1455 skip -gfile file-glob-pattern
1456 skip -function function
1457 skip -rfunction regular-expression
1458 A generalized form of the skip command, with new support for
1459 glob-style file names and regular expressions for function names.
1460 Additionally, a file spec and a function spec may now be combined.
1462 maint info line-table REGEXP
1463 Display the contents of GDB's internal line table data structure.
1466 Run any GDB unit tests that were compiled in.
1469 Start a new user interface instance running INTERP as interpreter,
1470 using the TTY file for input/output.
1474 ** gdb.Breakpoint objects have a new attribute "pending", which
1475 indicates whether the breakpoint is pending.
1476 ** Three new breakpoint-related events have been added:
1477 gdb.breakpoint_created, gdb.breakpoint_modified, and
1478 gdb.breakpoint_deleted.
1480 signal-event EVENTID
1481 Signal ("set") the given MS-Windows event object. This is used in
1482 conjunction with the Windows JIT debugging (AeDebug) support, where
1483 the OS suspends a crashing process until a debugger can attach to
1484 it. Resuming the crashing process, in order to debug it, is done by
1485 signalling an event.
1487 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1488 was added in GDBserver, including JIT compiling fast tracepoint's
1489 conditional expression bytecode into native code.
1491 * Support for various remote target protocols and ROM monitors has
1494 target m32rsdi Remote M32R debugging over SDI
1495 target mips MIPS remote debugging protocol
1496 target pmon PMON ROM monitor
1497 target ddb NEC's DDB variant of PMON for Vr4300
1498 target rockhopper NEC RockHopper variant of PMON
1499 target lsi LSI variant of PMO
1501 * Support for tracepoints and fast tracepoints on powerpc-linux,
1502 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1503 including JIT compiling fast tracepoint's conditional expression
1504 bytecode into native code.
1506 * MI async record =record-started now includes the method and format used for
1507 recording. For example:
1509 =record-started,thread-group="i1",method="btrace",format="bts"
1511 * MI async record =thread-selected now includes the frame field. For example:
1513 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1517 Andes NDS32 nds32*-*-elf
1519 *** Changes in GDB 7.11
1521 * GDB now supports debugging kernel-based threads on FreeBSD.
1523 * Per-inferior thread numbers
1525 Thread numbers are now per inferior instead of global. If you're
1526 debugging multiple inferiors, GDB displays thread IDs using a
1527 qualified INF_NUM.THR_NUM form. For example:
1531 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1532 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1533 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1534 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1536 As consequence, thread numbers as visible in the $_thread
1537 convenience variable and in Python's InferiorThread.num attribute
1538 are no longer unique between inferiors.
1540 GDB now maintains a second thread ID per thread, referred to as the
1541 global thread ID, which is the new equivalent of thread numbers in
1542 previous releases. See also $_gthread below.
1544 For backwards compatibility, MI's thread IDs always refer to global
1547 * Commands that accept thread IDs now accept the qualified
1548 INF_NUM.THR_NUM form as well. For example:
1551 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1554 * In commands that accept a list of thread IDs, you can now refer to
1555 all threads of an inferior using a star wildcard. GDB accepts
1556 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1557 refer to all threads of the current inferior. For example, "info
1560 * You can use "info threads -gid" to display the global thread ID of
1563 * The new convenience variable $_gthread holds the global number of
1566 * The new convenience variable $_inferior holds the number of the
1569 * GDB now displays the ID and name of the thread that hit a breakpoint
1570 or received a signal, if your program is multi-threaded. For
1573 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1574 Thread 1 "main" received signal SIGINT, Interrupt.
1576 * Record btrace now supports non-stop mode.
1578 * Support for tracepoints on aarch64-linux was added in GDBserver.
1580 * The 'record instruction-history' command now indicates speculative execution
1581 when using the Intel Processor Trace recording format.
1583 * GDB now allows users to specify explicit locations, bypassing
1584 the linespec parser. This feature is also available to GDB/MI
1587 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1588 GDB now is able to debug both AArch64 applications and ARM applications
1591 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1592 including JIT compiling fast tracepoint's conditional expression bytecode
1595 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1597 * "info threads", "info inferiors", "info display", "info checkpoints"
1598 and "maint info program-spaces" now list the corresponding items in
1599 ascending ID order, for consistency with all other "info" commands.
1601 * In Ada, the overloads selection menu has been enhanced to display the
1602 parameter types and the return types for the matching overloaded subprograms.
1606 maint set target-non-stop (on|off|auto)
1607 maint show target-non-stop
1608 Control whether GDB targets always operate in non-stop mode even if
1609 "set non-stop" is "off". The default is "auto", meaning non-stop
1610 mode is enabled if supported by the target.
1612 maint set bfd-sharing
1613 maint show bfd-sharing
1614 Control the reuse of bfd objects.
1617 show debug bfd-cache
1618 Control display of debugging info regarding bfd caching.
1622 Control display of debugging info regarding FreeBSD threads.
1624 set remote multiprocess-extensions-packet
1625 show remote multiprocess-extensions-packet
1626 Set/show the use of the remote protocol multiprocess extensions.
1628 set remote thread-events
1629 show remote thread-events
1630 Set/show the use of thread create/exit events.
1632 set ada print-signatures on|off
1633 show ada print-signatures"
1634 Control whether parameter types and return types are displayed in overloads
1635 selection menus. It is activated (@code{on}) by default.
1639 Controls the maximum size of memory, in bytes, that GDB will
1640 allocate for value contents. Prevents incorrect programs from
1641 causing GDB to allocate overly large buffers. Default is 64k.
1643 * The "disassemble" command accepts a new modifier: /s.
1644 It prints mixed source+disassembly like /m with two differences:
1645 - disassembled instructions are now printed in program order, and
1646 - and source for all relevant files is now printed.
1647 The "/m" option is now considered deprecated: its "source-centric"
1648 output hasn't proved useful in practice.
1650 * The "record instruction-history" command accepts a new modifier: /s.
1651 It behaves exactly like /m and prints mixed source+disassembly.
1653 * The "set scheduler-locking" command supports a new mode "replay".
1654 It behaves like "off" in record mode and like "on" in replay mode.
1656 * Support for various ROM monitors has been removed:
1658 target dbug dBUG ROM monitor for Motorola ColdFire
1659 target picobug Motorola picobug monitor
1660 target dink32 DINK32 ROM monitor for PowerPC
1661 target m32r Renesas M32R/D ROM monitor
1662 target mon2000 mon2000 ROM monitor
1663 target ppcbug PPCBUG ROM monitor for PowerPC
1665 * Support for reading/writing memory and extracting values on architectures
1666 whose memory is addressable in units of any integral multiple of 8 bits.
1669 Allows to break when an Ada exception is handled.
1671 * New remote packets
1674 Indicates that an exec system call was executed.
1676 exec-events feature in qSupported
1677 The qSupported packet allows GDB to request support for exec
1678 events using the new 'gdbfeature' exec-event, and the qSupported
1679 response can contain the corresponding 'stubfeature'. Set and
1680 show commands can be used to display whether these features are enabled.
1683 Equivalent to interrupting with the ^C character, but works in
1686 thread created stop reason (T05 create:...)
1687 Indicates that the thread was just created and is stopped at entry.
1689 thread exit stop reply (w exitcode;tid)
1690 Indicates that the thread has terminated.
1693 Enables/disables thread create and exit event reporting. For
1694 example, this is used in non-stop mode when GDB stops a set of
1695 threads and synchronously waits for the their corresponding stop
1696 replies. Without exit events, if one of the threads exits, GDB
1697 would hang forever not knowing that it should no longer expect a
1698 stop for that same thread.
1701 Indicates that there are no resumed threads left in the target (all
1702 threads are stopped). The remote stub reports support for this stop
1703 reply to GDB's qSupported query.
1706 Enables/disables catching syscalls from the inferior process.
1707 The remote stub reports support for this packet to GDB's qSupported query.
1709 syscall_entry stop reason
1710 Indicates that a syscall was just called.
1712 syscall_return stop reason
1713 Indicates that a syscall just returned.
1715 * Extended-remote exec events
1717 ** GDB now has support for exec events on extended-remote Linux targets.
1718 For such targets with Linux kernels 2.5.46 and later, this enables
1719 follow-exec-mode and exec catchpoints.
1721 set remote exec-event-feature-packet
1722 show remote exec-event-feature-packet
1723 Set/show the use of the remote exec event feature.
1725 * Thread names in remote protocol
1727 The reply to qXfer:threads:read may now include a name attribute for each
1730 * Target remote mode fork and exec events
1732 ** GDB now has support for fork and exec events on target remote mode
1733 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1734 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1735 fork and exec catchpoints.
1737 * Remote syscall events
1739 ** GDB now has support for catch syscall on remote Linux targets,
1740 currently enabled on x86/x86_64 architectures.
1742 set remote catch-syscall-packet
1743 show remote catch-syscall-packet
1744 Set/show the use of the remote catch syscall feature.
1748 ** The -var-set-format command now accepts the zero-hexadecimal
1749 format. It outputs data in hexadecimal format with zero-padding on the
1754 ** gdb.InferiorThread objects have a new attribute "global_num",
1755 which refers to the thread's global thread ID. The existing
1756 "num" attribute now refers to the thread's per-inferior number.
1757 See "Per-inferior thread numbers" above.
1758 ** gdb.InferiorThread objects have a new attribute "inferior", which
1759 is the Inferior object the thread belongs to.
1761 *** Changes in GDB 7.10
1763 * Support for process record-replay and reverse debugging on aarch64*-linux*
1764 targets has been added. GDB now supports recording of A64 instruction set
1765 including advance SIMD instructions.
1767 * Support for Sun's version of the "stabs" debug file format has been removed.
1769 * GDB now honors the content of the file /proc/PID/coredump_filter
1770 (PID is the process ID) on GNU/Linux systems. This file can be used
1771 to specify the types of memory mappings that will be included in a
1772 corefile. For more information, please refer to the manual page of
1773 "core(5)". GDB also has a new command: "set use-coredump-filter
1774 on|off". It allows to set whether GDB will read the content of the
1775 /proc/PID/coredump_filter file when generating a corefile.
1777 * The "info os" command on GNU/Linux can now display information on
1779 "info os cpus" Listing of all cpus/cores on the system
1781 * GDB has two new commands: "set serial parity odd|even|none" and
1782 "show serial parity". These allows to set or show parity for the
1785 * The "info source" command now displays the producer string if it was
1786 present in the debug info. This typically includes the compiler version
1787 and may include things like its command line arguments.
1789 * The "info dll", an alias of the "info sharedlibrary" command,
1790 is now available on all platforms.
1792 * Directory names supplied to the "set sysroot" commands may be
1793 prefixed with "target:" to tell GDB to access shared libraries from
1794 the target system, be it local or remote. This replaces the prefix
1795 "remote:". The default sysroot has been changed from "" to
1796 "target:". "remote:" is automatically converted to "target:" for
1797 backward compatibility.
1799 * The system root specified by "set sysroot" will be prepended to the
1800 filename of the main executable (if reported to GDB as absolute by
1801 the operating system) when starting processes remotely, and when
1802 attaching to already-running local or remote processes.
1804 * GDB now supports automatic location and retrieval of executable
1805 files from remote targets. Remote debugging can now be initiated
1806 using only a "target remote" or "target extended-remote" command
1807 (no "set sysroot" or "file" commands are required). See "New remote
1810 * The "dump" command now supports verilog hex format.
1812 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1814 * On GNU/Linux, GDB and gdbserver are now able to access executable
1815 and shared library files without a "set sysroot" command when
1816 attaching to processes running in different mount namespaces from
1817 the debugger. This makes it possible to attach to processes in
1818 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1819 See "New remote packets" below.
1821 * The "tui reg" command now provides completion for all of the
1822 available register groups, including target specific groups.
1824 * The HISTSIZE environment variable is no longer read when determining
1825 the size of GDB's command history. GDB now instead reads the dedicated
1826 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1827 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1832 ** Memory ports can now be unbuffered.
1836 ** gdb.Objfile objects have a new attribute "username",
1837 which is the name of the objfile as specified by the user,
1838 without, for example, resolving symlinks.
1839 ** You can now write frame unwinders in Python.
1840 ** gdb.Type objects have a new method "optimized_out",
1841 returning optimized out gdb.Value instance of this type.
1842 ** gdb.Value objects have new methods "reference_value" and
1843 "const_value" which return a reference to the value and a
1844 "const" version of the value respectively.
1848 maint print symbol-cache
1849 Print the contents of the symbol cache.
1851 maint print symbol-cache-statistics
1852 Print statistics of symbol cache usage.
1854 maint flush-symbol-cache
1855 Flush the contents of the symbol cache.
1859 Start branch trace recording using Branch Trace Store (BTS) format.
1862 Evaluate expression by using the compiler and print result.
1866 Explicit commands for enabling and disabling tui mode.
1869 set mpx bound on i386 and amd64
1870 Support for bound table investigation on Intel MPX enabled applications.
1874 Start branch trace recording using Intel Processor Trace format.
1877 Print information about branch tracing internals.
1879 maint btrace packet-history
1880 Print the raw branch tracing data.
1882 maint btrace clear-packet-history
1883 Discard the stored raw branch tracing data.
1886 Discard all branch tracing data. It will be fetched and processed
1887 anew by the next "record" command.
1892 Renamed from "set debug dwarf2-die".
1893 show debug dwarf-die
1894 Renamed from "show debug dwarf2-die".
1896 set debug dwarf-read
1897 Renamed from "set debug dwarf2-read".
1898 show debug dwarf-read
1899 Renamed from "show debug dwarf2-read".
1901 maint set dwarf always-disassemble
1902 Renamed from "maint set dwarf2 always-disassemble".
1903 maint show dwarf always-disassemble
1904 Renamed from "maint show dwarf2 always-disassemble".
1906 maint set dwarf max-cache-age
1907 Renamed from "maint set dwarf2 max-cache-age".
1908 maint show dwarf max-cache-age
1909 Renamed from "maint show dwarf2 max-cache-age".
1911 set debug dwarf-line
1912 show debug dwarf-line
1913 Control display of debugging info regarding DWARF line processing.
1916 show max-completions
1917 Set the maximum number of candidates to be considered during
1918 completion. The default value is 200. This limit allows GDB
1919 to avoid generating large completion lists, the computation of
1920 which can cause the debugger to become temporarily unresponsive.
1922 set history remove-duplicates
1923 show history remove-duplicates
1924 Control the removal of duplicate history entries.
1926 maint set symbol-cache-size
1927 maint show symbol-cache-size
1928 Control the size of the symbol cache.
1930 set|show record btrace bts buffer-size
1931 Set and show the size of the ring buffer used for branch tracing in
1933 The obtained size may differ from the requested size. Use "info
1934 record" to see the obtained buffer size.
1936 set debug linux-namespaces
1937 show debug linux-namespaces
1938 Control display of debugging info regarding Linux namespaces.
1940 set|show record btrace pt buffer-size
1941 Set and show the size of the ring buffer used for branch tracing in
1942 Intel Processor Trace format.
1943 The obtained size may differ from the requested size. Use "info
1944 record" to see the obtained buffer size.
1946 maint set|show btrace pt skip-pad
1947 Set and show whether PAD packets are skipped when computing the
1950 * The command 'thread apply all' can now support new option '-ascending'
1951 to call its specified command for all threads in ascending order.
1953 * Python/Guile scripting
1955 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1956 special section named `.debug_gdb_scripts'.
1958 * New remote packets
1960 qXfer:btrace-conf:read
1961 Return the branch trace configuration for the current thread.
1963 Qbtrace-conf:bts:size
1964 Set the requested ring buffer size for branch tracing in BTS format.
1967 Enable Intel Processor Trace-based branch tracing for the current
1968 process. The remote stub reports support for this packet to GDB's
1971 Qbtrace-conf:pt:size
1972 Set the requested ring buffer size for branch tracing in Intel Processor
1976 Indicates a memory breakpoint instruction was executed, irrespective
1977 of whether it was GDB that planted the breakpoint or the breakpoint
1978 is hardcoded in the program. This is required for correct non-stop
1982 Indicates the target stopped for a hardware breakpoint. This is
1983 required for correct non-stop mode operation.
1986 Return information about files on the remote system.
1988 qXfer:exec-file:read
1989 Return the full absolute name of the file that was executed to
1990 create a process running on the remote system.
1993 Select the filesystem on which vFile: operations with filename
1994 arguments will operate. This is required for GDB to be able to
1995 access files on remote targets where the remote stub does not
1996 share a common filesystem with the inferior(s).
1999 Indicates that a fork system call was executed.
2002 Indicates that a vfork system call was executed.
2004 vforkdone stop reason
2005 Indicates that a vfork child of the specified process has executed
2006 an exec or exit, allowing the vfork parent to resume execution.
2008 fork-events and vfork-events features in qSupported
2009 The qSupported packet allows GDB to request support for fork and
2010 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2011 and the qSupported response can contain the corresponding
2012 'stubfeatures'. Set and show commands can be used to display
2013 whether these features are enabled.
2015 * Extended-remote fork events
2017 ** GDB now has support for fork events on extended-remote Linux
2018 targets. For targets with Linux kernels 2.5.60 and later, this
2019 enables follow-fork-mode and detach-on-fork for both fork and
2020 vfork, as well as fork and vfork catchpoints.
2022 * The info record command now shows the recording format and the
2023 branch tracing configuration for the current thread when using
2024 the btrace record target.
2025 For the BTS format, it shows the ring buffer size.
2027 * GDB now has support for DTrace USDT (Userland Static Defined
2028 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2030 * GDB now supports access to vector registers on S/390 GNU/Linux
2033 * Removed command line options
2035 -xdb HP-UX XDB compatibility mode.
2037 * Removed targets and native configurations
2039 HP/PA running HP-UX hppa*-*-hpux*
2040 Itanium running HP-UX ia64-*-hpux*
2042 * New configure options
2045 This configure option allows the user to build GDB with support for
2046 Intel Processor Trace (default: auto). This requires libipt.
2048 --with-libipt-prefix=PATH
2049 Specify the path to the version of libipt that GDB should use.
2050 $PATH/include should contain the intel-pt.h header and
2051 $PATH/lib should contain the libipt.so library.
2053 *** Changes in GDB 7.9.1
2057 ** Xmethods can now specify a result type.
2059 *** Changes in GDB 7.9
2061 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2065 ** You can now access frame registers from Python scripts.
2066 ** New attribute 'producer' for gdb.Symtab objects.
2067 ** gdb.Objfile objects have a new attribute "progspace",
2068 which is the gdb.Progspace object of the containing program space.
2069 ** gdb.Objfile objects have a new attribute "owner".
2070 ** gdb.Objfile objects have a new attribute "build_id",
2071 which is the build ID generated when the file was built.
2072 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2073 ** A new event "gdb.clear_objfiles" has been added, triggered when
2074 selecting a new file to debug.
2075 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2076 ** New function gdb.lookup_objfile.
2078 New events which are triggered when GDB modifies the state of the
2081 ** gdb.events.inferior_call_pre: Function call is about to be made.
2082 ** gdb.events.inferior_call_post: Function call has just been made.
2083 ** gdb.events.memory_changed: A memory location has been altered.
2084 ** gdb.events.register_changed: A register has been altered.
2086 * New Python-based convenience functions:
2088 ** $_caller_is(name [, number_of_frames])
2089 ** $_caller_matches(regexp [, number_of_frames])
2090 ** $_any_caller_is(name [, number_of_frames])
2091 ** $_any_caller_matches(regexp [, number_of_frames])
2093 * GDB now supports the compilation and injection of source code into
2094 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2095 to compile the source code to object code, and if successful, inject
2096 and execute that code within the current context of the inferior.
2097 Currently the C language is supported. The commands used to
2098 interface with this new feature are:
2100 compile code [-raw|-r] [--] [source code]
2101 compile file [-raw|-r] filename
2105 demangle [-l language] [--] name
2106 Demangle "name" in the specified language, or the current language
2107 if elided. This command is renamed from the "maint demangle" command.
2108 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2109 as "maint demangler-warning".
2111 queue-signal signal-name-or-number
2112 Queue a signal to be delivered to the thread when it is resumed.
2114 add-auto-load-scripts-directory directory
2115 Add entries to the list of directories from which to load auto-loaded
2118 maint print user-registers
2119 List all currently available "user" registers.
2121 compile code [-r|-raw] [--] [source code]
2122 Compile, inject, and execute in the inferior the executable object
2123 code produced by compiling the provided source code.
2125 compile file [-r|-raw] filename
2126 Compile and inject into the inferior the executable object code
2127 produced by compiling the source code stored in the filename
2130 * On resume, GDB now always passes the signal the program had stopped
2131 for to the thread the signal was sent to, even if the user changed
2132 threads before resuming. Previously GDB would often (but not
2133 always) deliver the signal to the thread that happens to be current
2136 * Conversely, the "signal" command now consistently delivers the
2137 requested signal to the current thread. GDB now asks for
2138 confirmation if the program had stopped for a signal and the user
2139 switched threads meanwhile.
2141 * "breakpoint always-inserted" modes "off" and "auto" merged.
2143 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2144 won't remove breakpoints from the target until all threads stop,
2145 even in non-stop mode. The "auto" mode has been removed, and "off"
2146 is now the default mode.
2150 set debug symbol-lookup
2151 show debug symbol-lookup
2152 Control display of debugging info regarding symbol lookup.
2156 ** The -list-thread-groups command outputs an exit-code field for
2157 inferiors that have exited.
2161 MIPS SDE mips*-sde*-elf*
2165 Support for these obsolete configurations has been removed.
2167 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2168 SGI Irix-5.x mips-*-irix5*
2169 SGI Irix-6.x mips-*-irix6*
2170 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2171 VAX running Ultrix vax-*-ultrix*
2173 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2174 and "assf"), have been removed. Use the "sharedlibrary" command, or
2175 its alias "share", instead.
2177 *** Changes in GDB 7.8
2179 * New command line options
2182 This is an alias for the --data-directory option.
2184 * GDB supports printing and modifying of variable length automatic arrays
2185 as specified in ISO C99.
2187 * The ARM simulator now supports instruction level tracing
2188 with or without disassembly.
2192 GDB now has support for scripting using Guile. Whether this is
2193 available is determined at configure time.
2194 Guile version 2.0 or greater is required.
2195 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2197 * New commands (for set/show, see "New options" below)
2201 Invoke CODE by passing it to the Guile interpreter.
2205 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2207 info auto-load guile-scripts [regexp]
2208 Print the list of automatically loaded Guile scripts.
2210 * The source command is now capable of sourcing Guile scripts.
2211 This feature is dependent on the debugger being built with Guile support.
2215 set print symbol-loading (off|brief|full)
2216 show print symbol-loading
2217 Control whether to print informational messages when loading symbol
2218 information for a file. The default is "full", but when debugging
2219 programs with large numbers of shared libraries the amount of output
2220 becomes less useful.
2222 set guile print-stack (none|message|full)
2223 show guile print-stack
2224 Show a stack trace when an error is encountered in a Guile script.
2226 set auto-load guile-scripts (on|off)
2227 show auto-load guile-scripts
2228 Control auto-loading of Guile script files.
2230 maint ada set ignore-descriptive-types (on|off)
2231 maint ada show ignore-descriptive-types
2232 Control whether the debugger should ignore descriptive types in Ada
2233 programs. The default is not to ignore the descriptive types. See
2234 the user manual for more details on descriptive types and the intended
2235 usage of this option.
2237 set auto-connect-native-target
2239 Control whether GDB is allowed to automatically connect to the
2240 native target for the run, attach, etc. commands when not connected
2241 to any target yet. See also "target native" below.
2243 set record btrace replay-memory-access (read-only|read-write)
2244 show record btrace replay-memory-access
2245 Control what memory accesses are allowed during replay.
2247 maint set target-async (on|off)
2248 maint show target-async
2249 This controls whether GDB targets operate in synchronous or
2250 asynchronous mode. Normally the default is asynchronous, if it is
2251 available; but this can be changed to more easily debug problems
2252 occurring only in synchronous mode.
2254 set mi-async (on|off)
2256 Control whether MI asynchronous mode is preferred. This supersedes
2257 "set target-async" of previous GDB versions.
2259 * "set target-async" is deprecated as a CLI option and is now an alias
2260 for "set mi-async" (only puts MI into async mode).
2262 * Background execution commands (e.g., "c&", "s&", etc.) are now
2263 possible ``out of the box'' if the target supports them. Previously
2264 the user would need to explicitly enable the possibility with the
2265 "set target-async on" command.
2267 * New features in the GDB remote stub, GDBserver
2269 ** New option --debug-format=option1[,option2,...] allows one to add
2270 additional text to each output. At present only timestamps
2271 are supported: --debug-format=timestamps.
2272 Timestamps can also be turned on with the
2273 "monitor set debug-format timestamps" command from GDB.
2275 * The 'record instruction-history' command now starts counting instructions
2276 at one. This also affects the instruction ranges reported by the
2277 'record function-call-history' command when given the /i modifier.
2279 * The command 'record function-call-history' supports a new modifier '/c' to
2280 indent the function names based on their call stack depth.
2281 The fields for the '/i' and '/l' modifier have been reordered.
2282 The source line range is now prefixed with 'at'.
2283 The instruction range is now prefixed with 'inst'.
2284 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2285 "record instruction-history" and "list" commands.
2287 * The ranges given as arguments to the 'record function-call-history' and
2288 'record instruction-history' commands are now inclusive.
2290 * The btrace record target now supports the 'record goto' command.
2291 For locations inside the execution trace, the back trace is computed
2292 based on the information stored in the execution trace.
2294 * The btrace record target supports limited reverse execution and replay.
2295 The target does not record data and therefore does not allow reading
2296 memory or registers.
2298 * The "catch syscall" command now works on s390*-linux* targets.
2300 * The "compare-sections" command is no longer specific to target
2301 remote. It now works with all targets.
2303 * All native targets are now consistently called "native".
2304 Consequently, the "target child", "target GNU", "target djgpp",
2305 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2306 commands have been replaced with "target native". The QNX/NTO port
2307 leaves the "procfs" target in place and adds a "native" target for
2308 consistency with other ports. The impact on users should be minimal
2309 as these commands previously either throwed an error, or were
2310 no-ops. The target's name is visible in the output of the following
2311 commands: "help target", "info target", "info files", "maint print
2314 * The "target native" command now connects to the native target. This
2315 can be used to launch native programs even when "set
2316 auto-connect-native-target" is set to off.
2318 * GDB now supports access to Intel MPX registers on GNU/Linux.
2320 * Support for Intel AVX-512 registers on GNU/Linux.
2321 Support displaying and modifying Intel AVX-512 registers
2322 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2324 * New remote packets
2326 qXfer:btrace:read's annex
2327 The qXfer:btrace:read packet supports a new annex 'delta' to read
2328 branch trace incrementally.
2332 ** Valid Python operations on gdb.Value objects representing
2333 structs/classes invoke the corresponding overloaded operators if
2335 ** New `Xmethods' feature in the Python API. Xmethods are
2336 additional methods or replacements for existing methods of a C++
2337 class. This feature is useful for those cases where a method
2338 defined in C++ source code could be inlined or optimized out by
2339 the compiler, making it unavailable to GDB.
2342 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2344 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2345 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2346 its alias "share", instead.
2348 * The commands "set remotebaud" and "show remotebaud" are no longer
2349 supported. Use "set serial baud" and "show serial baud" (respectively)
2354 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2355 target-async". The latter is left as a deprecated alias of the
2356 former for backward compatibility. If the target supports it,
2357 CLI background execution commands are now always possible by
2358 default, independently of whether the frontend stated a
2359 preference for asynchronous execution with "-gdb-set mi-async".
2360 Previously "-gdb-set target-async off" affected both MI execution
2361 commands and CLI execution commands.
2363 *** Changes in GDB 7.7
2365 * Improved support for process record-replay and reverse debugging on
2366 arm*-linux* targets. Support for thumb32 and syscall instruction
2367 recording has been added.
2369 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2371 * GDB now supports Fission DWP file format version 2.
2372 http://gcc.gnu.org/wiki/DebugFission
2374 * New convenience function "$_isvoid", to check whether an expression
2375 is void. A void expression is an expression where the type of the
2376 result is "void". For example, some convenience variables may be
2377 "void" when evaluated (e.g., "$_exitcode" before the execution of
2378 the program being debugged; or an undefined convenience variable).
2379 Another example, when calling a function whose return type is
2382 * The "maintenance print objfiles" command now takes an optional regexp.
2384 * The "catch syscall" command now works on arm*-linux* targets.
2386 * GDB now consistently shows "<not saved>" when printing values of
2387 registers the debug info indicates have not been saved in the frame
2388 and there's nowhere to retrieve them from
2389 (callee-saved/call-clobbered registers):
2394 (gdb) info registers rax
2397 Before, the former would print "<optimized out>", and the latter
2398 "*value not available*".
2400 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2405 ** Frame filters and frame decorators have been added.
2406 ** Temporary breakpoints are now supported.
2407 ** Line tables representation has been added.
2408 ** New attribute 'parent_type' for gdb.Field objects.
2409 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2410 ** New attribute 'name' for gdb.Type objects.
2414 Nios II ELF nios2*-*-elf
2415 Nios II GNU/Linux nios2*-*-linux
2416 Texas Instruments MSP430 msp430*-*-elf
2418 * Removed native configurations
2420 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2421 been removed. ELF variants of these configurations are kept supported.
2423 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2424 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2425 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2426 i[34567]86-*-openbsd3.[0-3]
2427 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2428 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2429 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2433 Like "catch throw", but catches a re-thrown exception.
2434 maint check-psymtabs
2435 Renamed from old "maint check-symtabs".
2437 Perform consistency checks on symtabs.
2438 maint expand-symtabs
2439 Expand symtabs matching an optional regexp.
2442 Display the details of GDB configure-time options.
2444 maint set|show per-command
2445 maint set|show per-command space
2446 maint set|show per-command time
2447 maint set|show per-command symtab
2448 Enable display of per-command gdb resource usage.
2450 remove-symbol-file FILENAME
2451 remove-symbol-file -a ADDRESS
2452 Remove a symbol file added via add-symbol-file. The file to remove
2453 can be identified by its filename or by an address that lies within
2454 the boundaries of this symbol file in memory.
2457 info exceptions REGEXP
2458 Display the list of Ada exceptions defined in the program being
2459 debugged. If provided, only the exceptions whose names match REGEXP
2464 set debug symfile off|on
2466 Control display of debugging info regarding reading symbol files and
2467 symbol tables within those files
2469 set print raw frame-arguments
2470 show print raw frame-arguments
2471 Set/show whether to print frame arguments in raw mode,
2472 disregarding any defined pretty-printers.
2474 set remote trace-status-packet
2475 show remote trace-status-packet
2476 Set/show the use of remote protocol qTStatus packet.
2480 Control display of debugging messages related to Nios II targets.
2484 Control whether target-assisted range stepping is enabled.
2486 set startup-with-shell
2487 show startup-with-shell
2488 Specifies whether Unix child processes are started via a shell or
2493 Use the target memory cache for accesses to the code segment. This
2494 improves performance of remote debugging (particularly disassembly).
2496 * You can now use a literal value 'unlimited' for options that
2497 interpret 0 or -1 as meaning "unlimited". E.g., "set
2498 trace-buffer-size unlimited" is now an alias for "set
2499 trace-buffer-size -1" and "set height unlimited" is now an alias for
2502 * The "set debug symtab-create" debugging option of GDB has been changed to
2503 accept a verbosity level. 0 means "off", 1 provides basic debugging
2504 output, and values of 2 or greater provides more verbose output.
2506 * New command-line options
2508 Display the details of GDB configure-time options.
2510 * The command 'tsave' can now support new option '-ctf' to save trace
2511 buffer in Common Trace Format.
2513 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2516 * GDB now implements the C++ 'typeid' operator.
2518 * The new convenience variable $_exception holds the exception being
2519 thrown or caught at an exception-related catchpoint.
2521 * The exception-related catchpoints, like "catch throw", now accept a
2522 regular expression which can be used to filter exceptions by type.
2524 * The new convenience variable $_exitsignal is automatically set to
2525 the terminating signal number when the program being debugged dies
2526 due to an uncaught signal.
2530 ** All MI commands now accept an optional "--language" option.
2531 Support for this feature can be verified by using the "-list-features"
2532 command, which should contain "language-option".
2534 ** The new command -info-gdb-mi-command allows the user to determine
2535 whether a GDB/MI command is supported or not.
2537 ** The "^error" result record returned when trying to execute an undefined
2538 GDB/MI command now provides a variable named "code" whose content is the
2539 "undefined-command" error code. Support for this feature can be verified
2540 by using the "-list-features" command, which should contain
2541 "undefined-command-error-code".
2543 ** The -trace-save MI command can optionally save trace buffer in Common
2546 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2548 ** The command -data-list-register-values now accepts an optional
2549 "--skip-unavailable" option. When used, only the available registers
2552 ** The new command -trace-frame-collected dumps collected variables,
2553 computed expressions, tvars, memory and registers in a traceframe.
2555 ** The commands -stack-list-locals, -stack-list-arguments and
2556 -stack-list-variables now accept an option "--skip-unavailable".
2557 When used, only the available locals or arguments are displayed.
2559 ** The -exec-run command now accepts an optional "--start" option.
2560 When used, the command follows the same semantics as the "start"
2561 command, stopping the program's execution at the start of its
2562 main subprogram. Support for this feature can be verified using
2563 the "-list-features" command, which should contain
2564 "exec-run-start-option".
2566 ** The new commands -catch-assert and -catch-exceptions insert
2567 catchpoints stopping the program when Ada exceptions are raised.
2569 ** The new command -info-ada-exceptions provides the equivalent of
2570 the new "info exceptions" command.
2572 * New system-wide configuration scripts
2573 A GDB installation now provides scripts suitable for use as system-wide
2574 configuration scripts for the following systems:
2578 * GDB now supports target-assigned range stepping with remote targets.
2579 This improves the performance of stepping source lines by reducing
2580 the number of control packets from/to GDB. See "New remote packets"
2583 * GDB now understands the element 'tvar' in the XML traceframe info.
2584 It has the id of the collected trace state variables.
2586 * On S/390 targets that provide the transactional-execution feature,
2587 the program interruption transaction diagnostic block (TDB) is now
2588 represented as a number of additional "registers" in GDB.
2590 * New remote packets
2594 The vCont packet supports a new 'r' action, that tells the remote
2595 stub to step through an address range itself, without GDB
2596 involvemement at each single-step.
2598 qXfer:libraries-svr4:read's annex
2599 The previously unused annex of the qXfer:libraries-svr4:read packet
2600 is now used to support passing an argument list. The remote stub
2601 reports support for this argument list to GDB's qSupported query.
2602 The defined arguments are "start" and "prev", used to reduce work
2603 necessary for library list updating, resulting in significant
2606 * New features in the GDB remote stub, GDBserver
2608 ** GDBserver now supports target-assisted range stepping. Currently
2609 enabled on x86/x86_64 GNU/Linux targets.
2611 ** GDBserver now adds element 'tvar' in the XML in the reply to
2612 'qXfer:traceframe-info:read'. It has the id of the collected
2613 trace state variables.
2615 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2618 * New 'z' formatter for printing and examining memory, this displays the
2619 value as hexadecimal zero padded on the left to the size of the type.
2621 * GDB can now use Windows x64 unwinding data.
2623 * The "set remotebaud" command has been replaced by "set serial baud".
2624 Similarly, "show remotebaud" has been replaced by "show serial baud".
2625 The "set remotebaud" and "show remotebaud" commands are still available
2626 to provide backward compatibility with older versions of GDB.
2628 *** Changes in GDB 7.6
2630 * Target record has been renamed to record-full.
2631 Record/replay is now enabled with the "record full" command.
2632 This also affects settings that are associated with full record/replay
2633 that have been moved from "set/show record" to "set/show record full":
2635 set|show record full insn-number-max
2636 set|show record full stop-at-limit
2637 set|show record full memory-query
2639 * A new record target "record-btrace" has been added. The new target
2640 uses hardware support to record the control-flow of a process. It
2641 does not support replaying the execution, but it implements the
2642 below new commands for investigating the recorded execution log.
2643 This new recording method can be enabled using:
2647 The "record-btrace" target is only available on Intel Atom processors
2648 and requires a Linux kernel 2.6.32 or later.
2650 * Two new commands have been added for record/replay to give information
2651 about the recorded execution without having to replay the execution.
2652 The commands are only supported by "record btrace".
2654 record instruction-history prints the execution history at
2655 instruction granularity
2657 record function-call-history prints the execution history at
2658 function granularity
2660 * New native configurations
2662 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2663 FreeBSD/powerpc powerpc*-*-freebsd
2664 x86_64/Cygwin x86_64-*-cygwin*
2665 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2669 ARM AArch64 aarch64*-*-elf
2670 ARM AArch64 GNU/Linux aarch64*-*-linux
2671 Lynx 178 PowerPC powerpc-*-lynx*178
2672 x86_64/Cygwin x86_64-*-cygwin*
2673 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2675 * If the configured location of system.gdbinit file (as given by the
2676 --with-system-gdbinit option at configure time) is in the
2677 data-directory (as specified by --with-gdb-datadir at configure
2678 time) or in one of its subdirectories, then GDB will look for the
2679 system-wide init file in the directory specified by the
2680 --data-directory command-line option.
2682 * New command line options:
2684 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2685 other initialization files, unlike -nx which disables all of them.
2687 * Removed command line options
2689 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2692 * The 'ptype' and 'whatis' commands now accept an argument to control
2695 * 'info proc' now works on some core files.
2699 ** Vectors can be created with gdb.Type.vector.
2701 ** Python's atexit.register now works in GDB.
2703 ** Types can be pretty-printed via a Python API.
2705 ** Python 3 is now supported (in addition to Python 2.4 or later)
2707 ** New class gdb.Architecture exposes GDB's internal representation
2708 of architecture in the Python API.
2710 ** New method Frame.architecture returns the gdb.Architecture object
2711 corresponding to the frame's architecture.
2713 * New Python-based convenience functions:
2715 ** $_memeq(buf1, buf2, length)
2716 ** $_streq(str1, str2)
2718 ** $_regex(str, regex)
2720 * The 'cd' command now defaults to using '~' (the home directory) if not
2723 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2724 default for GCC since November 2000.
2726 * The command 'forward-search' can now be abbreviated as 'fo'.
2728 * The command 'info tracepoints' can now display 'installed on target'
2729 or 'not installed on target' for each non-pending location of tracepoint.
2731 * New configure options
2733 --enable-libmcheck/--disable-libmcheck
2734 By default, development versions are built with -lmcheck on hosts
2735 that support it, in order to help track memory corruption issues.
2736 Release versions, on the other hand, are built without -lmcheck
2737 by default. The --enable-libmcheck/--disable-libmcheck configure
2738 options allow the user to override that default.
2739 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2740 This configure option allows the user to build GDB with
2741 libbabeltrace using which GDB can read Common Trace Format data.
2743 * New commands (for set/show, see "New options" below)
2746 Catch signals. This is similar to "handle", but allows commands and
2747 conditions to be attached.
2750 List the BFDs known to GDB.
2752 python-interactive [command]
2754 Start a Python interactive prompt, or evaluate the optional command
2755 and print the result of expressions.
2758 "py" is a new alias for "python".
2760 enable type-printer [name]...
2761 disable type-printer [name]...
2762 Enable or disable type printers.
2766 ** For the Renesas Super-H architecture, the "regs" command has been removed
2767 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2772 set print type methods (on|off)
2773 show print type methods
2774 Control whether method declarations are displayed by "ptype".
2775 The default is to show them.
2777 set print type typedefs (on|off)
2778 show print type typedefs
2779 Control whether typedef definitions are displayed by "ptype".
2780 The default is to show them.
2782 set filename-display basename|relative|absolute
2783 show filename-display
2784 Control the way in which filenames is displayed.
2785 The default is "relative", which preserves previous behavior.
2787 set trace-buffer-size
2788 show trace-buffer-size
2789 Request target to change the size of trace buffer.
2791 set remote trace-buffer-size-packet auto|on|off
2792 show remote trace-buffer-size-packet
2793 Control the use of the remote protocol `QTBuffer:size' packet.
2797 Control display of debugging messages related to ARM AArch64.
2800 set debug coff-pe-read
2801 show debug coff-pe-read
2802 Control display of debugging messages related to reading of COFF/PE
2807 Control display of debugging messages related to Mach-O symbols
2810 set debug notification
2811 show debug notification
2812 Control display of debugging info for async remote notification.
2816 ** Command parameter changes are now notified using new async record
2817 "=cmd-param-changed".
2818 ** Trace frame changes caused by command "tfind" are now notified using
2819 new async record "=traceframe-changed".
2820 ** The creation, deletion and modification of trace state variables
2821 are now notified using new async records "=tsv-created",
2822 "=tsv-deleted" and "=tsv-modified".
2823 ** The start and stop of process record are now notified using new
2824 async record "=record-started" and "=record-stopped".
2825 ** Memory changes are now notified using new async record
2827 ** The data-disassemble command response will include a "fullname" field
2828 containing the absolute file name when source has been requested.
2829 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2830 command, to allow pattern filling of memory areas.
2831 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2832 library load/unload events.
2833 ** The response to breakpoint commands and breakpoint async records
2834 includes an "installed" field containing a boolean state about each
2835 non-pending tracepoint location is whether installed on target or not.
2836 ** Output of the "-trace-status" command includes a "trace-file" field
2837 containing the name of the trace file being examined. This field is
2838 optional, and only present when examining a trace file.
2839 ** The "fullname" field is now always present along with the "file" field,
2840 even if the file cannot be found by GDB.
2842 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2843 You must have the LZMA library available when configuring GDB for this
2844 feature to be enabled. For more information, see:
2845 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2847 * New remote packets
2850 Set the size of trace buffer. The remote stub reports support for this
2851 packet to gdb's qSupported query.
2854 Enable Branch Trace Store (BTS)-based branch tracing for the current
2855 thread. The remote stub reports support for this packet to gdb's
2859 Disable branch tracing for the current thread. The remote stub reports
2860 support for this packet to gdb's qSupported query.
2863 Read the traced branches for the current thread. The remote stub
2864 reports support for this packet to gdb's qSupported query.
2866 *** Changes in GDB 7.5
2868 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2869 for more x32 ABI info.
2871 * GDB now supports access to MIPS DSP registers on Linux targets.
2873 * GDB now supports debugging microMIPS binaries.
2875 * The "info os" command on GNU/Linux can now display information on
2876 several new classes of objects managed by the operating system:
2877 "info os procgroups" lists process groups
2878 "info os files" lists file descriptors
2879 "info os sockets" lists internet-domain sockets
2880 "info os shm" lists shared-memory regions
2881 "info os semaphores" lists semaphores
2882 "info os msg" lists message queues
2883 "info os modules" lists loaded kernel modules
2885 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2886 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2887 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2888 options and inspect the probe arguments using the new $_probe_arg family
2889 of convenience variables. You can obtain more information about SystemTap
2890 in <http://sourceware.org/systemtap/>.
2892 * GDB now supports reversible debugging on ARM, it allows you to
2893 debug basic ARM and THUMB instructions, and provides
2894 record/replay support.
2896 * The option "symbol-reloading" has been deleted as it is no longer used.
2900 ** GDB commands implemented in Python can now be put in command class
2903 ** The "maint set python print-stack on|off" is now deleted.
2905 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2906 apply "flag enum"-style pretty-printing to any enum.
2908 ** gdb.lookup_symbol can now work when there is no current frame.
2910 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2911 the source at which the symbol was defined.
2913 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2914 method 'value'. The former indicates whether the symbol needs a
2915 frame in order to compute its value, and the latter computes the
2918 ** A new method 'referenced_value' on gdb.Value objects which can
2919 dereference pointer as well as C++ reference values.
2921 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2922 which return the global and static blocks (as gdb.Block objects),
2923 of the underlying symbol table, respectively.
2925 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2926 object associated with a PC value.
2928 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2929 of the address range occupied by code for the current source line.
2931 * Go language support.
2932 GDB now supports debugging programs written in the Go programming
2935 * GDBserver now supports stdio connections.
2936 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2938 * The binary "gdbtui" can no longer be built or installed.
2939 Use "gdb -tui" instead.
2941 * GDB will now print "flag" enums specially. A flag enum is one where
2942 all the enumerator values have no bits in common when pairwise
2943 "and"ed. When printing a value whose type is a flag enum, GDB will
2944 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2945 (gdb) print (enum E) 3
2948 * The filename part of a linespec will now match trailing components
2949 of a source file name. For example, "break gcc/expr.c:1000" will
2950 now set a breakpoint in build/gcc/expr.c, but not
2951 build/libcpp/expr.c.
2953 * The "info proc" and "generate-core-file" commands will now also
2954 work on remote targets connected to GDBserver on Linux.
2956 * The command "info catch" has been removed. It has been disabled
2957 since December 2007.
2959 * The "catch exception" and "catch assert" commands now accept
2960 a condition at the end of the command, much like the "break"
2961 command does. For instance:
2963 (gdb) catch exception Constraint_Error if Barrier = True
2965 Previously, it was possible to add a condition to such catchpoints,
2966 but it had to be done as a second step, after the catchpoint had been
2967 created, using the "condition" command.
2969 * The "info static-tracepoint-marker" command will now also work on
2970 native Linux targets with in-process agent.
2972 * GDB can now set breakpoints on inlined functions.
2974 * The .gdb_index section has been updated to include symbols for
2975 inlined functions. GDB will ignore older .gdb_index sections by
2976 default, which could cause symbol files to be loaded more slowly
2977 until their .gdb_index sections can be recreated. The new command
2978 "set use-deprecated-index-sections on" will cause GDB to use any older
2979 .gdb_index sections it finds. This will restore performance, but the
2980 ability to set breakpoints on inlined functions will be lost in symbol
2981 files with older .gdb_index sections.
2983 The .gdb_index section has also been updated to record more information
2984 about each symbol. This speeds up the "info variables", "info functions"
2985 and "info types" commands when used with programs having the .gdb_index
2986 section, as well as speeding up debugging with shared libraries using
2987 the .gdb_index section.
2989 * Ada support for GDB/MI Variable Objects has been added.
2991 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2996 ** New command -info-os is the MI equivalent of "info os".
2998 ** Output logs ("set logging" and related) now include MI output.
3002 ** "set use-deprecated-index-sections on|off"
3003 "show use-deprecated-index-sections on|off"
3004 Controls the use of deprecated .gdb_index sections.
3006 ** "catch load" and "catch unload" can be used to stop when a shared
3007 library is loaded or unloaded, respectively.
3009 ** "enable count" can be used to auto-disable a breakpoint after
3012 ** "info vtbl" can be used to show the virtual method tables for
3013 C++ and Java objects.
3015 ** "explore" and its sub commands "explore value" and "explore type"
3016 can be used to recursively explore values and types of
3017 expressions. These commands are available only if GDB is
3018 configured with '--with-python'.
3020 ** "info auto-load" shows status of all kinds of auto-loaded files,
3021 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3022 sequences of commands files, "info auto-load python-scripts"
3023 shows status of auto-loading Python script files,
3024 "info auto-load local-gdbinit" shows status of loading init file
3025 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3026 status of inferior specific thread debugging shared library loading.
3028 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3029 and "show auto-load-scripts" commands have been deprecated, use their
3030 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3031 and "show auto-load python-scripts" counterparts instead.
3033 ** "dprintf location,format,args..." creates a dynamic printf, which
3034 is basically a breakpoint that does a printf and immediately
3035 resumes your program's execution, so it is like a printf that you
3036 can insert dynamically at runtime instead of at compiletime.
3038 ** "set print symbol"
3040 Controls whether GDB attempts to display the symbol, if any,
3041 corresponding to addresses it prints. This defaults to "on", but
3042 you can set it to "off" to restore GDB's previous behavior.
3044 * Deprecated commands
3046 ** For the Renesas Super-H architecture, the "regs" command has been
3047 deprecated, and "info all-registers" should be used instead.
3051 Renesas RL78 rl78-*-elf
3052 HP OpenVMS ia64 ia64-hp-openvms*
3054 * GDBserver supports evaluation of breakpoint conditions. When
3055 support is advertised by GDBserver, GDB may be told to send the
3056 breakpoint conditions in bytecode form to GDBserver. GDBserver
3057 will only report the breakpoint trigger to GDB when its condition
3062 set mips compression
3063 show mips compression
3064 Select the compressed ISA encoding used in functions that have no symbol
3065 information available. The encoding can be set to either of:
3068 and is updated automatically from ELF file flags if available.
3070 set breakpoint condition-evaluation
3071 show breakpoint condition-evaluation
3072 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3073 GDBserver ("target"). Default option "auto" chooses the most efficient
3075 This option can improve debugger efficiency depending on the speed of the
3079 Disable auto-loading globally.
3082 Show auto-loading setting of all kinds of auto-loaded files.
3084 set auto-load gdb-scripts on|off
3085 show auto-load gdb-scripts
3086 Control auto-loading of GDB canned sequences of commands files.
3088 set auto-load python-scripts on|off
3089 show auto-load python-scripts
3090 Control auto-loading of Python script files.
3092 set auto-load local-gdbinit on|off
3093 show auto-load local-gdbinit
3094 Control loading of init file (.gdbinit) from current directory.
3096 set auto-load libthread-db on|off
3097 show auto-load libthread-db
3098 Control auto-loading of inferior specific thread debugging shared library.
3100 set auto-load scripts-directory <dir1>[:<dir2>...]
3101 show auto-load scripts-directory
3102 Set a list of directories from which to load auto-loaded scripts.
3103 Automatically loaded Python scripts and GDB scripts are located in one
3104 of the directories listed by this option.
3105 The delimiter (':' above) may differ according to the host platform.
3107 set auto-load safe-path <dir1>[:<dir2>...]
3108 show auto-load safe-path
3109 Set a list of directories from which it is safe to auto-load files.
3110 The delimiter (':' above) may differ according to the host platform.
3112 set debug auto-load on|off
3113 show debug auto-load
3114 Control display of debugging info for auto-loading the files above.
3116 set dprintf-style gdb|call|agent
3118 Control the way in which a dynamic printf is performed; "gdb"
3119 requests a GDB printf command, while "call" causes dprintf to call a
3120 function in the inferior. "agent" requests that the target agent
3121 (such as GDBserver) do the printing.
3123 set dprintf-function <expr>
3124 show dprintf-function
3125 set dprintf-channel <expr>
3126 show dprintf-channel
3127 Set the function and optional first argument to the call when using
3128 the "call" style of dynamic printf.
3130 set disconnected-dprintf on|off
3131 show disconnected-dprintf
3132 Control whether agent-style dynamic printfs continue to be in effect
3133 after GDB disconnects.
3135 * New configure options
3137 --with-auto-load-dir
3138 Configure default value for the 'set auto-load scripts-directory'
3139 setting above. It defaults to '$debugdir:$datadir/auto-load',
3140 $debugdir representing global debugging info directories (available
3141 via 'show debug-file-directory') and $datadir representing GDB's data
3142 directory (available via 'show data-directory').
3144 --with-auto-load-safe-path
3145 Configure default value for the 'set auto-load safe-path' setting
3146 above. It defaults to the --with-auto-load-dir setting.
3148 --without-auto-load-safe-path
3149 Set 'set auto-load safe-path' to '/', effectively disabling this
3152 * New remote packets
3154 z0/z1 conditional breakpoints extension
3156 The z0/z1 breakpoint insertion packets have been extended to carry
3157 a list of conditional expressions over to the remote stub depending on the
3158 condition evaluation mode. The use of this extension can be controlled
3159 via the "set remote conditional-breakpoints-packet" command.
3163 Specify the signals which the remote stub may pass to the debugged
3164 program without GDB involvement.
3166 * New command line options
3168 --init-command=FILE, -ix Like --command, -x but execute it
3169 before loading inferior.
3170 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3171 execute it before loading inferior.
3173 *** Changes in GDB 7.4
3175 * GDB now handles ambiguous linespecs more consistently; the existing
3176 FILE:LINE support has been expanded to other types of linespecs. A
3177 breakpoint will now be set on all matching locations in all
3178 inferiors, and locations will be added or removed according to
3181 * GDB now allows you to skip uninteresting functions and files when
3182 stepping with the "skip function" and "skip file" commands.
3184 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3185 and "show remote hardware-watchpoint-length-limit". These allows to
3186 set or show the maximum length limit (in bytes) of a remote
3187 target hardware watchpoint.
3189 This allows e.g. to use "unlimited" hardware watchpoints with the
3190 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3191 watchpoints are slower than real hardware watchpoints but are
3192 significantly faster than gdb software watchpoints.
3196 ** The register_pretty_printer function in module gdb.printing now takes
3197 an optional `replace' argument. If True, the new printer replaces any
3200 ** The "maint set python print-stack on|off" command has been
3201 deprecated and will be deleted in GDB 7.5.
3202 A new command: "set python print-stack none|full|message" has
3203 replaced it. Additionally, the default for "print-stack" is
3204 now "message", which just prints the error message without
3207 ** A prompt substitution hook (prompt_hook) is now available to the
3210 ** A new Python module, gdb.prompt has been added to the GDB Python
3211 modules library. This module provides functionality for
3212 escape sequences in prompts (used by set/show
3213 extended-prompt). These escape sequences are replaced by their
3214 corresponding value.
3216 ** Python commands and convenience-functions located in
3217 'data-directory'/python/gdb/command and
3218 'data-directory'/python/gdb/function are now automatically loaded
3221 ** Blocks now provide four new attributes. global_block and
3222 static_block will return the global and static blocks
3223 respectively. is_static and is_global are boolean attributes
3224 that indicate if the block is one of those two types.
3226 ** Symbols now provide the "type" attribute, the type of the symbol.
3228 ** The "gdb.breakpoint" function has been deprecated in favor of
3231 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3232 of a function. This class is based on the "finish" command
3233 available in the CLI.
3235 ** Type objects for struct and union types now allow access to
3236 the fields using standard Python dictionary (mapping) methods.
3237 For example, "some_type['myfield']" now works, as does
3238 "some_type.items()".
3240 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3243 ** A new function, "deep_items" has been added to the gdb.types
3244 module in the GDB Python modules library. This function returns
3245 an iterator over the fields of a struct or union type. Unlike
3246 the standard Python "iteritems" method, it will recursively traverse
3247 any anonymous fields.
3251 ** "*stopped" events can report several new "reason"s, such as
3254 ** Breakpoint changes are now notified using new async records, like
3255 "=breakpoint-modified".
3257 ** New command -ada-task-info.
3259 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3260 $sdir specifies the default system locations of shared libraries.
3261 $pdir specifies the directory where the libpthread used by the application
3264 GDB no longer looks in $sdir and $pdir after it has searched the directories
3265 mentioned in libthread-db-search-path. If you want to search those
3266 directories, they must be specified in libthread-db-search-path.
3267 The default value of libthread-db-search-path on GNU/Linux and Solaris
3268 systems is now "$sdir:$pdir".
3270 $pdir is not supported by gdbserver, it is currently ignored.
3271 $sdir is supported by gdbserver.
3273 * New configure option --with-iconv-bin.
3274 When using the internationalization support like the one in the GNU C
3275 library, GDB will invoke the "iconv" program to get a list of supported
3276 character sets. If this program lives in a non-standard location, one can
3277 use this option to specify where to find it.
3279 * When natively debugging programs on PowerPC BookE processors running
3280 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3281 watchpoints, which specify a mask in addition to an address to watch.
3282 The mask specifies that some bits of an address (the bits which are
3283 reset in the mask) should be ignored when matching the address accessed
3284 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3285 section in the user manual for more details.
3287 * The new option --once causes GDBserver to stop listening for connections once
3288 the first connection is made. The listening port used by GDBserver will
3289 become available after that.
3291 * New commands "info macros" and "alias" have been added.
3293 * New function parameters suffix @entry specifies value of function parameter
3294 at the time the function got called. Entry values are available only since
3300 "!" is now an alias of the "shell" command.
3301 Note that no space is needed between "!" and SHELL COMMAND.
3305 watch EXPRESSION mask MASK_VALUE
3306 The watch command now supports the mask argument which allows creation
3307 of masked watchpoints, if the current architecture supports this feature.
3309 info auto-load-scripts [REGEXP]
3310 This command was formerly named "maintenance print section-scripts".
3311 It is now generally useful and is no longer a maintenance-only command.
3313 info macro [-all] [--] MACRO
3314 The info macro command has new options `-all' and `--'. The first for
3315 printing all definitions of a macro. The second for explicitly specifying
3316 the end of arguments and the beginning of the macro name in case the macro
3317 name starts with a hyphen.
3319 collect[/s] EXPRESSIONS
3320 The tracepoint collect command now takes an optional modifier "/s"
3321 that directs it to dereference pointer-to-character types and
3322 collect the bytes of memory up to a zero byte. The behavior is
3323 similar to what you see when you use the regular print command on a
3324 string. An optional integer following the "/s" sets a bound on the
3325 number of bytes that will be collected.
3328 The trace start command now interprets any supplied arguments as a
3329 note to be recorded with the trace run, with an effect similar to
3330 setting the variable trace-notes.
3333 The trace stop command now interprets any arguments as a note to be
3334 mentioned along with the tstatus report that the trace was stopped
3335 with a command. The effect is similar to setting the variable
3338 * Tracepoints can now be enabled and disabled at any time after a trace
3339 experiment has been started using the standard "enable" and "disable"
3340 commands. It is now possible to start a trace experiment with no enabled
3341 tracepoints; GDB will display a warning, but will allow the experiment to
3342 begin, assuming that tracepoints will be enabled as needed while the trace
3345 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3346 locations with 4-byte instructions, when they were previously
3347 limited to locations with instructions of 5 bytes or longer.
3351 set debug dwarf2-read
3352 show debug dwarf2-read
3353 Turns on or off display of debugging messages related to reading
3354 DWARF debug info. The default is off.
3356 set debug symtab-create
3357 show debug symtab-create
3358 Turns on or off display of debugging messages related to symbol table
3359 creation. The default is off.
3362 show extended-prompt
3363 Set the GDB prompt, and allow escape sequences to be inserted to
3364 display miscellaneous information (see 'help set extended-prompt'
3365 for the list of sequences). This prompt (and any information
3366 accessed through the escape sequences) is updated every time the
3367 prompt is displayed.
3369 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3370 show print entry-values
3371 Set printing of frame argument values at function entry. In some cases
3372 GDB can determine the value of function argument which was passed by the
3373 function caller, even if the value was modified inside the called function.
3375 set debug entry-values
3376 show debug entry-values
3377 Control display of debugging info for determining frame argument values at
3378 function entry and virtual tail call frames.
3380 set basenames-may-differ
3381 show basenames-may-differ
3382 Set whether a source file may have multiple base names.
3383 (A "base name" is the name of a file with the directory part removed.
3384 Example: The base name of "/home/user/hello.c" is "hello.c".)
3385 If set, GDB will canonicalize file names (e.g., expand symlinks)
3386 before comparing them. Canonicalization is an expensive operation,
3387 but it allows the same file be known by more than one base name.
3388 If not set (the default), all source files are assumed to have just
3389 one base name, and gdb will do file name comparisons more efficiently.
3395 Set a user name and notes for the current and any future trace runs.
3396 This is useful for long-running and/or disconnected traces, to
3397 inform others (or yourself) as to who is running the trace, supply
3398 contact information, or otherwise explain what is going on.
3400 set trace-stop-notes
3401 show trace-stop-notes
3402 Set a note attached to the trace run, that is displayed when the
3403 trace has been stopped by a tstop command. This is useful for
3404 instance as an explanation, if you are stopping a trace run that was
3405 started by someone else.
3407 * New remote packets
3411 Dynamically enable a tracepoint in a started trace experiment.
3415 Dynamically disable a tracepoint in a started trace experiment.
3419 Set the user and notes of the trace run.
3423 Query the current status of a tracepoint.
3427 Query the minimum length of instruction at which a fast tracepoint may
3430 * Dcache size (number of lines) and line-size are now runtime-configurable
3431 via "set dcache line" and "set dcache line-size" commands.
3435 Texas Instruments TMS320C6x tic6x-*-*
3439 Renesas RL78 rl78-*-elf
3441 *** Changes in GDB 7.3.1
3443 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3445 *** Changes in GDB 7.3
3447 * GDB has a new command: "thread find [REGEXP]".
3448 It finds the thread id whose name, target id, or thread extra info
3449 matches the given regular expression.
3451 * The "catch syscall" command now works on mips*-linux* targets.
3453 * The -data-disassemble MI command now supports modes 2 and 3 for
3454 dumping the instruction opcodes.
3456 * New command line options
3458 -data-directory DIR Specify DIR as the "data-directory".
3459 This is mostly for testing purposes.
3461 * The "maint set python auto-load on|off" command has been renamed to
3462 "set auto-load-scripts on|off".
3464 * GDB has a new command: "set directories".
3465 It is like the "dir" command except that it replaces the
3466 source path list instead of augmenting it.
3468 * GDB now understands thread names.
3470 On GNU/Linux, "info threads" will display the thread name as set by
3471 prctl or pthread_setname_np.
3473 There is also a new command, "thread name", which can be used to
3474 assign a name internally for GDB to display.
3477 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3478 has been integrated into GDB.
3482 ** The function gdb.Write now accepts an optional keyword 'stream'.
3483 This keyword, when provided, will direct the output to either
3484 stdout, stderr, or GDB's logging output.
3486 ** Parameters can now be be sub-classed in Python, and in particular
3487 you may implement the get_set_doc and get_show_doc functions.
3488 This improves how Parameter set/show documentation is processed
3489 and allows for more dynamic content.
3491 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3492 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3493 have an is_valid method.
3495 ** Breakpoints can now be sub-classed in Python, and in particular
3496 you may implement a 'stop' function that is executed each time
3497 the inferior reaches that breakpoint.
3499 ** New function gdb.lookup_global_symbol looks up a global symbol.
3501 ** GDB values in Python are now callable if the value represents a
3502 function. For example, if 'some_value' represents a function that
3503 takes two integer parameters and returns a value, you can call
3504 that function like so:
3506 result = some_value (10,20)
3508 ** Module gdb.types has been added.
3509 It contains a collection of utilities for working with gdb.Types objects:
3510 get_basic_type, has_field, make_enum_dict.
3512 ** Module gdb.printing has been added.
3513 It contains utilities for writing and registering pretty-printers.
3514 New classes: PrettyPrinter, SubPrettyPrinter,
3515 RegexpCollectionPrettyPrinter.
3516 New function: register_pretty_printer.
3518 ** New commands "info pretty-printers", "enable pretty-printer" and
3519 "disable pretty-printer" have been added.
3521 ** gdb.parameter("directories") is now available.
3523 ** New function gdb.newest_frame returns the newest frame in the
3526 ** The gdb.InferiorThread class has a new "name" attribute. This
3527 holds the thread's name.
3529 ** Python Support for Inferior events.
3530 Python scripts can add observers to be notified of events
3531 occurring in the process being debugged.
3532 The following events are currently supported:
3533 - gdb.events.cont Continue event.
3534 - gdb.events.exited Inferior exited event.
3535 - gdb.events.stop Signal received, and Breakpoint hit events.
3539 ** GDB now puts template parameters in scope when debugging in an
3540 instantiation. For example, if you have:
3542 template<int X> int func (void) { return X; }
3544 then if you step into func<5>, "print X" will show "5". This
3545 feature requires proper debuginfo support from the compiler; it
3546 was added to GCC 4.5.
3548 ** The motion commands "next", "finish", "until", and "advance" now
3549 work better when exceptions are thrown. In particular, GDB will
3550 no longer lose control of the inferior; instead, the GDB will
3551 stop the inferior at the point at which the exception is caught.
3552 This functionality requires a change in the exception handling
3553 code that was introduced in GCC 4.5.
3555 * GDB now follows GCC's rules on accessing volatile objects when
3556 reading or writing target state during expression evaluation.
3557 One notable difference to prior behavior is that "print x = 0"
3558 no longer generates a read of x; the value of the assignment is
3559 now always taken directly from the value being assigned.
3561 * GDB now has some support for using labels in the program's source in
3562 linespecs. For instance, you can use "advance label" to continue
3563 execution to a label.
3565 * GDB now has support for reading and writing a new .gdb_index
3566 section. This section holds a fast index of DWARF debugging
3567 information and can be used to greatly speed up GDB startup and
3568 operation. See the documentation for `save gdb-index' for details.
3570 * The "watch" command now accepts an optional "-location" argument.
3571 When used, this causes GDB to watch the memory referred to by the
3572 expression. Such a watchpoint is never deleted due to it going out
3575 * GDB now supports thread debugging of core dumps on GNU/Linux.
3577 GDB now activates thread debugging using the libthread_db library
3578 when debugging GNU/Linux core dumps, similarly to when debugging
3579 live processes. As a result, when debugging a core dump file, GDB
3580 is now able to display pthread_t ids of threads. For example, "info
3581 threads" shows the same output as when debugging the process when it
3582 was live. In earlier releases, you'd see something like this:
3585 * 1 LWP 6780 main () at main.c:10
3587 While now you see this:
3590 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3592 It is also now possible to inspect TLS variables when debugging core
3595 When debugging a core dump generated on a machine other than the one
3596 used to run GDB, you may need to point GDB at the correct
3597 libthread_db library with the "set libthread-db-search-path"
3598 command. See the user manual for more details on this command.
3600 * When natively debugging programs on PowerPC BookE processors running
3601 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3602 which stop execution of the inferior whenever it executes an instruction
3603 at any address within the specified range. See the "PowerPC Embedded"
3604 section in the user manual for more details.
3606 * New features in the GDB remote stub, GDBserver
3608 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3609 and i686 LynxOS (version 5.x).
3611 ** GDBserver is now supported on Blackfin Linux.
3613 * New native configurations
3615 ia64 HP-UX ia64-*-hpux*
3619 Analog Devices, Inc. Blackfin Processor bfin-*
3621 * Ada task switching is now supported on sparc-elf targets when
3622 debugging a program using the Ravenscar Profile. For more information,
3623 see the "Tasking Support when using the Ravenscar Profile" section
3624 in the GDB user manual.
3626 * Guile support was removed.
3628 * New features in the GNU simulator
3630 ** The --map-info flag lists all known core mappings.
3632 ** CFI flashes may be simulated via the "cfi" device.
3634 *** Changes in GDB 7.2
3636 * Shared library support for remote targets by default
3638 When GDB is configured for a generic, non-OS specific target, like
3639 for example, --target=arm-eabi or one of the many *-*-elf targets,
3640 GDB now queries remote stubs for loaded shared libraries using the
3641 `qXfer:libraries:read' packet. Previously, shared library support
3642 was always disabled for such configurations.
3646 ** Argument Dependent Lookup (ADL)
3648 In C++ ADL lookup directs function search to the namespaces of its
3649 arguments even if the namespace has not been imported.
3659 Here the compiler will search for `foo' in the namespace of 'b'
3660 and find A::foo. GDB now supports this. This construct is commonly
3661 used in the Standard Template Library for operators.
3663 ** Improved User Defined Operator Support
3665 In addition to member operators, GDB now supports lookup of operators
3666 defined in a namespace and imported with a `using' directive, operators
3667 defined in the global scope, operators imported implicitly from an
3668 anonymous namespace, and the ADL operators mentioned in the previous
3670 GDB now also supports proper overload resolution for all the previously
3671 mentioned flavors of operators.
3673 ** static const class members
3675 Printing of static const class members that are initialized in the
3676 class definition has been fixed.
3678 * Windows Thread Information Block access.
3680 On Windows targets, GDB now supports displaying the Windows Thread
3681 Information Block (TIB) structure. This structure is visible either
3682 by using the new command `info w32 thread-information-block' or, by
3683 dereferencing the new convenience variable named `$_tlb', a
3684 thread-specific pointer to the TIB. This feature is also supported
3685 when remote debugging using GDBserver.
3687 * Static tracepoints
3689 Static tracepoints are calls in the user program into a tracing
3690 library. One such library is a port of the LTTng kernel tracer to
3691 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3692 When debugging with GDBserver, GDB now supports combining the GDB
3693 tracepoint machinery with such libraries. For example: the user can
3694 use GDB to probe a static tracepoint marker (a call from the user
3695 program into the tracing library) with the new "strace" command (see
3696 "New commands" below). This creates a "static tracepoint" in the
3697 breakpoint list, that can be manipulated with the same feature set
3698 as fast and regular tracepoints. E.g., collect registers, local and
3699 global variables, collect trace state variables, and define
3700 tracepoint conditions. In addition, the user can collect extra
3701 static tracepoint marker specific data, by collecting the new
3702 $_sdata internal variable. When analyzing the trace buffer, you can
3703 inspect $_sdata like any other variable available to GDB. For more
3704 information, see the "Tracepoints" chapter in GDB user manual. New
3705 remote packets have been defined to support static tracepoints, see
3706 the "New remote packets" section below.
3708 * Better reconstruction of tracepoints after disconnected tracing
3710 GDB will attempt to download the original source form of tracepoint
3711 definitions when starting a trace run, and then will upload these
3712 upon reconnection to the target, resulting in a more accurate
3713 reconstruction of the tracepoints that are in use on the target.
3717 You can now exercise direct control over the ways that GDB can
3718 affect your program. For instance, you can disallow the setting of
3719 breakpoints, so that the program can run continuously (assuming
3720 non-stop mode). In addition, the "observer" variable is available
3721 to switch all of the different controls; in observer mode, GDB
3722 cannot affect the target's behavior at all, which is useful for
3723 tasks like diagnosing live systems in the field.
3725 * The new convenience variable $_thread holds the number of the
3728 * New remote packets
3732 Return the address of the Windows Thread Information Block of a given thread.
3736 In response to several of the tracepoint packets, the target may now
3737 also respond with a number of intermediate `qRelocInsn' request
3738 packets before the final result packet, to have GDB handle
3739 relocating an instruction to execute at a different address. This
3740 is particularly useful for stubs that support fast tracepoints. GDB
3741 reports support for this feature in the qSupported packet.
3745 List static tracepoint markers in the target program.
3749 List static tracepoint markers at a given address in the target
3752 qXfer:statictrace:read
3754 Read the static trace data collected (by a `collect $_sdata'
3755 tracepoint action). The remote stub reports support for this packet
3756 to gdb's qSupported query.
3760 Send the current settings of GDB's permission flags.
3764 Send part of the source (textual) form of a tracepoint definition,
3765 which includes location, conditional, and action list.
3767 * The source command now accepts a -s option to force searching for the
3768 script in the source search path even if the script name specifies
3771 * New features in the GDB remote stub, GDBserver
3773 - GDBserver now support tracepoints (including fast tracepoints, and
3774 static tracepoints). The feature is currently supported by the
3775 i386-linux and amd64-linux builds. See the "Tracepoints support
3776 in gdbserver" section in the manual for more information.
3778 GDBserver JIT compiles the tracepoint's conditional agent
3779 expression bytecode into native code whenever possible for low
3780 overhead dynamic tracepoints conditionals. For such tracepoints,
3781 an expression that examines program state is evaluated when the
3782 tracepoint is reached, in order to determine whether to capture
3783 trace data. If the condition is simple and false, processing the
3784 tracepoint finishes very quickly and no data is gathered.
3786 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3787 for static tracepoints support.
3789 - GDBserver now supports x86_64 Windows 64-bit debugging.
3791 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3792 it understands register description.
3794 * The --batch flag now disables pagination and queries.
3796 * X86 general purpose registers
3798 GDB now supports reading/writing byte, word and double-word x86
3799 general purpose registers directly. This means you can use, say,
3800 $ah or $ax to refer, respectively, to the byte register AH and
3801 16-bit word register AX that are actually portions of the 32-bit
3802 register EAX or 64-bit register RAX.
3804 * The `commands' command now accepts a range of breakpoints to modify.
3805 A plain `commands' following a command that creates multiple
3806 breakpoints affects all the breakpoints set by that command. This
3807 applies to breakpoints set by `rbreak', and also applies when a
3808 single `break' command creates multiple breakpoints (e.g.,
3809 breakpoints on overloaded c++ functions).
3811 * The `rbreak' command now accepts a filename specification as part of
3812 its argument, limiting the functions selected by the regex to those
3813 in the specified file.
3815 * Support for remote debugging Windows and SymbianOS shared libraries
3816 from Unix hosts has been improved. Non Windows GDB builds now can
3817 understand target reported file names that follow MS-DOS based file
3818 system semantics, such as file names that include drive letters and
3819 use the backslash character as directory separator. This makes it
3820 possible to transparently use the "set sysroot" and "set
3821 solib-search-path" on Unix hosts to point as host copies of the
3822 target's shared libraries. See the new command "set
3823 target-file-system-kind" described below, and the "Commands to
3824 specify files" section in the user manual for more information.
3828 eval template, expressions...
3829 Convert the values of one or more expressions under the control
3830 of the string template to a command line, and call it.
3832 set target-file-system-kind unix|dos-based|auto
3833 show target-file-system-kind
3834 Set or show the assumed file system kind for target reported file
3837 save breakpoints <filename>
3838 Save all current breakpoint definitions to a file suitable for use
3839 in a later debugging session. To read the saved breakpoint
3840 definitions, use the `source' command.
3842 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3845 info static-tracepoint-markers
3846 Display information about static tracepoint markers in the target.
3848 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3849 Define a static tracepoint by probing a marker at the given
3850 function, line, address, or marker ID.
3854 Enable and disable observer mode.
3856 set may-write-registers on|off
3857 set may-write-memory on|off
3858 set may-insert-breakpoints on|off
3859 set may-insert-tracepoints on|off
3860 set may-insert-fast-tracepoints on|off
3861 set may-interrupt on|off
3862 Set individual permissions for GDB effects on the target. Note that
3863 some of these settings can have undesirable or surprising
3864 consequences, particularly when changed in the middle of a session.
3865 For instance, disabling the writing of memory can prevent
3866 breakpoints from being inserted, cause single-stepping to fail, or
3867 even crash your program, if you disable after breakpoints have been
3868 inserted. However, GDB should not crash.
3870 set record memory-query on|off
3871 show record memory-query
3872 Control whether to stop the inferior if memory changes caused
3873 by an instruction cannot be recorded.
3878 The disassemble command now supports "start,+length" form of two arguments.
3882 ** GDB now provides a new directory location, called the python directory,
3883 where Python scripts written for GDB can be installed. The location
3884 of that directory is <data-directory>/python, where <data-directory>
3885 is the GDB data directory. For more details, see section `Scripting
3886 GDB using Python' in the manual.
3888 ** The GDB Python API now has access to breakpoints, symbols, symbol
3889 tables, program spaces, inferiors, threads and frame's code blocks.
3890 Additionally, GDB Parameters can now be created from the API, and
3891 manipulated via set/show in the CLI.
3893 ** New functions gdb.target_charset, gdb.target_wide_charset,
3894 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3896 ** New exception gdb.GdbError.
3898 ** Pretty-printers are now also looked up in the current program space.
3900 ** Pretty-printers can now be individually enabled and disabled.
3902 ** GDB now looks for names of Python scripts to auto-load in a
3903 special section named `.debug_gdb_scripts', in addition to looking
3904 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3906 * Tracepoint actions were unified with breakpoint commands. In particular,
3907 there are no longer differences in "info break" output for breakpoints and
3908 tracepoints and the "commands" command can be used for both tracepoints and
3909 regular breakpoints.
3913 ARM Symbian arm*-*-symbianelf*
3915 * D language support.
3916 GDB now supports debugging programs written in the D programming
3919 * GDB now supports the extended ptrace interface for PowerPC which is
3920 available since Linux kernel version 2.6.34. This automatically enables
3921 any hardware breakpoints and additional hardware watchpoints available in
3922 the processor. The old ptrace interface exposes just one hardware
3923 watchpoint and no hardware breakpoints.
3925 * GDB is now able to use the Data Value Compare (DVC) register available on
3926 embedded PowerPC processors to implement in hardware simple watchpoint
3927 conditions of the form:
3929 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3931 This works in native GDB running on Linux kernels with the extended ptrace
3932 interface mentioned above.
3934 *** Changes in GDB 7.1
3938 ** Namespace Support
3940 GDB now supports importing of namespaces in C++. This enables the
3941 user to inspect variables from imported namespaces. Support for
3942 namepace aliasing has also been added. So, if a namespace is
3943 aliased in the current scope (e.g. namepace C=A; ) the user can
3944 print variables using the alias (e.g. (gdb) print C::x).
3948 All known bugs relating to the printing of virtual base class were
3949 fixed. It is now possible to call overloaded static methods using a
3954 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3955 and reinterpret_cast<> are now handled by the C++ expression parser.
3959 Xilinx MicroBlaze microblaze-*-*
3964 Xilinx MicroBlaze microblaze
3967 * Multi-program debugging.
3969 GDB now has support for multi-program (a.k.a. multi-executable or
3970 multi-exec) debugging. This allows for debugging multiple inferiors
3971 simultaneously each running a different program under the same GDB
3972 session. See "Debugging Multiple Inferiors and Programs" in the
3973 manual for more information. This implied some user visible changes
3974 in the multi-inferior support. For example, "info inferiors" now
3975 lists inferiors that are not running yet or that have exited
3976 already. See also "New commands" and "New options" below.
3978 * New tracing features
3980 GDB's tracepoint facility now includes several new features:
3982 ** Trace state variables
3984 GDB tracepoints now include support for trace state variables, which
3985 are variables managed by the target agent during a tracing
3986 experiment. They are useful for tracepoints that trigger each
3987 other, so for instance one tracepoint can count hits in a variable,
3988 and then a second tracepoint has a condition that is true when the
3989 count reaches a particular value. Trace state variables share the
3990 $-syntax of GDB convenience variables, and can appear in both
3991 tracepoint actions and condition expressions. Use the "tvariable"
3992 command to create, and "info tvariables" to view; see "Trace State
3993 Variables" in the manual for more detail.
3997 GDB now includes an option for defining fast tracepoints, which
3998 targets may implement more efficiently, such as by installing a jump
3999 into the target agent rather than a trap instruction. The resulting
4000 speedup can be by two orders of magnitude or more, although the
4001 tradeoff is that some program locations on some target architectures
4002 might not allow fast tracepoint installation, for instance if the
4003 instruction to be replaced is shorter than the jump. To request a
4004 fast tracepoint, use the "ftrace" command, with syntax identical to
4005 the regular trace command.
4007 ** Disconnected tracing
4009 It is now possible to detach GDB from the target while it is running
4010 a trace experiment, then reconnect later to see how the experiment
4011 is going. In addition, a new variable disconnected-tracing lets you
4012 tell the target agent whether to continue running a trace if the
4013 connection is lost unexpectedly.
4017 GDB now has the ability to save the trace buffer into a file, and
4018 then use that file as a target, similarly to you can do with
4019 corefiles. You can select trace frames, print data that was
4020 collected in them, and use tstatus to display the state of the
4021 tracing run at the moment that it was saved. To create a trace
4022 file, use "tsave <filename>", and to use it, do "target tfile
4025 ** Circular trace buffer
4027 You can ask the target agent to handle the trace buffer as a
4028 circular buffer, discarding the oldest trace frames to make room for
4029 newer ones, by setting circular-trace-buffer to on. This feature may
4030 not be available for all target agents.
4035 The disassemble command, when invoked with two arguments, now requires
4036 the arguments to be comma-separated.
4039 The info variables command now displays variable definitions. Files
4040 which only declare a variable are not shown.
4043 The source command is now capable of sourcing Python scripts.
4044 This feature is dependent on the debugger being build with Python
4047 Related to this enhancement is also the introduction of a new command
4048 "set script-extension" (see below).
4050 * New commands (for set/show, see "New options" below)
4052 record save [<FILENAME>]
4053 Save a file (in core file format) containing the process record
4054 execution log for replay debugging at a later time.
4056 record restore <FILENAME>
4057 Restore the process record execution log that was saved at an
4058 earlier time, for replay debugging.
4060 add-inferior [-copies <N>] [-exec <FILENAME>]
4063 clone-inferior [-copies <N>] [ID]
4064 Make a new inferior ready to execute the same program another
4065 inferior has loaded.
4070 maint info program-spaces
4071 List the program spaces loaded into GDB.
4073 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4074 show remote interrupt-sequence
4075 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4076 as the sequence to the remote target in order to interrupt the execution.
4077 Ctrl-C is a default. Some system prefers BREAK which is high level of
4078 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4079 Magic SysRq g. It is BREAK signal and character 'g'.
4081 set remote interrupt-on-connect [on | off]
4082 show remote interrupt-on-connect
4083 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4084 remote target when gdb connects to it. This is needed when you debug
4087 set remotebreak [on | off]
4089 Deprecated. Use "set/show remote interrupt-sequence" instead.
4091 tvariable $NAME [ = EXP ]
4092 Create or modify a trace state variable.
4095 List trace state variables and their values.
4097 delete tvariable $NAME ...
4098 Delete one or more trace state variables.
4101 Evaluate the given expressions without collecting anything into the
4102 trace buffer. (Valid in tracepoint actions only.)
4104 ftrace FN / FILE:LINE / *ADDR
4105 Define a fast tracepoint at the given function, line, or address.
4107 * New expression syntax
4109 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4110 GDB now parses 0b101010 identically with 42.
4114 set follow-exec-mode new|same
4115 show follow-exec-mode
4116 Control whether GDB reuses the same inferior across an exec call or
4117 creates a new one. This is useful to be able to restart the old
4118 executable after the inferior having done an exec call.
4120 set default-collect EXPR, ...
4121 show default-collect
4122 Define a list of expressions to be collected at each tracepoint.
4123 This is a useful way to ensure essential items are not overlooked,
4124 such as registers or a critical global variable.
4126 set disconnected-tracing
4127 show disconnected-tracing
4128 If set to 1, the target is instructed to continue tracing if it
4129 loses its connection to GDB. If 0, the target is to stop tracing
4132 set circular-trace-buffer
4133 show circular-trace-buffer
4134 If set to on, the target is instructed to use a circular trace buffer
4135 and discard the oldest trace frames instead of stopping the trace due
4136 to a full trace buffer. If set to off, the trace stops when the buffer
4137 fills up. Some targets may not support this.
4139 set script-extension off|soft|strict
4140 show script-extension
4141 If set to "off", the debugger does not perform any script language
4142 recognition, and all sourced files are assumed to be GDB scripts.
4143 If set to "soft" (the default), files are sourced according to
4144 filename extension, falling back to GDB scripts if the first
4146 If set to "strict", files are sourced according to filename extension.
4148 set ada trust-PAD-over-XVS on|off
4149 show ada trust-PAD-over-XVS
4150 If off, activate a workaround against a bug in the debugging information
4151 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4152 the GCC sources for more information about the GNAT encoding and
4153 PAD types in particular). It is always safe to set this option to
4154 off, but this introduces a slight performance penalty. The default
4157 * Python API Improvements
4159 ** GDB provides the new class gdb.LazyString. This is useful in
4160 some pretty-printing cases. The new method gdb.Value.lazy_string
4161 provides a simple way to create objects of this type.
4163 ** The fields returned by gdb.Type.fields now have an
4164 `is_base_class' attribute.
4166 ** The new method gdb.Type.range returns the range of an array type.
4168 ** The new method gdb.parse_and_eval can be used to parse and
4169 evaluate an expression.
4171 * New remote packets
4174 Define a trace state variable.
4177 Get the current value of a trace state variable.
4180 Set desired tracing behavior upon disconnection.
4183 Set the trace buffer to be linear or circular.
4186 Get data about the tracepoints currently in use.
4190 Process record now works correctly with hardware watchpoints.
4192 Multiple bug fixes have been made to the mips-irix port, making it
4193 much more reliable. In particular:
4194 - Debugging threaded applications is now possible again. Previously,
4195 GDB would hang while starting the program, or while waiting for
4196 the program to stop at a breakpoint.
4197 - Attaching to a running process no longer hangs.
4198 - An error occurring while loading a core file has been fixed.
4199 - Changing the value of the PC register now works again. This fixes
4200 problems observed when using the "jump" command, or when calling
4201 a function from GDB, or even when assigning a new value to $pc.
4202 - With the "finish" and "return" commands, the return value for functions
4203 returning a small array is now correctly printed.
4204 - It is now possible to break on shared library code which gets executed
4205 during a shared library init phase (code executed while executing
4206 their .init section). Previously, the breakpoint would have no effect.
4207 - GDB is now able to backtrace through the signal handler for
4208 non-threaded programs.
4210 PIE (Position Independent Executable) programs debugging is now supported.
4211 This includes debugging execution of PIC (Position Independent Code) shared
4212 libraries although for that, it should be possible to run such libraries as an
4215 *** Changes in GDB 7.0
4217 * GDB now has an interface for JIT compilation. Applications that
4218 dynamically generate code can create symbol files in memory and register
4219 them with GDB. For users, the feature should work transparently, and
4220 for JIT developers, the interface is documented in the GDB manual in the
4221 "JIT Compilation Interface" chapter.
4223 * Tracepoints may now be conditional. The syntax is as for
4224 breakpoints; either an "if" clause appended to the "trace" command,
4225 or the "condition" command is available. GDB sends the condition to
4226 the target for evaluation using the same bytecode format as is used
4227 for tracepoint actions.
4229 * The disassemble command now supports: an optional /r modifier, print the
4230 raw instructions in hex as well as in symbolic form, and an optional /m
4231 modifier to print mixed source+assembly.
4233 * Process record and replay
4235 In a architecture environment that supports ``process record and
4236 replay'', ``process record and replay'' target can record a log of
4237 the process execution, and replay it with both forward and reverse
4240 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4241 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4242 set execution-direction {forward|reverse}, for targets that support
4245 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4246 feature is available with a native GDB running on kernel version
4249 * GDB now has support for multi-byte and wide character sets on the
4250 target. Strings whose character type is wchar_t, char16_t, or
4251 char32_t are now correctly printed. GDB supports wide- and unicode-
4252 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4253 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4254 `printf'. This feature requires iconv to work properly; if your
4255 system does not have a working iconv, GDB can use GNU libiconv. See
4256 the installation instructions for more information.
4258 * GDB now supports automatic retrieval of shared library files from
4259 remote targets. To use this feature, specify a system root that begins
4260 with the `remote:' prefix, either via the `set sysroot' command or via
4261 the `--with-sysroot' configure-time option.
4263 * "info sharedlibrary" now takes an optional regex of libraries to show,
4264 and it now reports if a shared library has no debugging information.
4266 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4267 now complete on file names.
4269 * When completing in expressions, gdb will attempt to limit
4270 completions to allowable structure or union fields, where appropriate.
4271 For instance, consider:
4273 # struct example { int f1; double f2; };
4274 # struct example variable;
4277 If the user types TAB at the end of this command line, the available
4278 completions will be "f1" and "f2".
4280 * Inlined functions are now supported. They show up in backtraces, and
4281 the "step", "next", and "finish" commands handle them automatically.
4283 * GDB now supports the token-splicing (##) and stringification (#)
4284 operators when expanding macros. It also supports variable-arity
4287 * GDB now supports inspecting extra signal information, exported by
4288 the new $_siginfo convenience variable. The feature is currently
4289 implemented on linux ARM, i386 and amd64.
4291 * GDB can now display the VFP floating point registers and NEON vector
4292 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4293 can provide these registers (requires Linux 2.6.30 or later). Remote
4294 and simulator targets may also provide them.
4296 * New remote packets
4299 Search memory for a sequence of bytes.
4302 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4303 operation over reliable transport links. Use of this packet is
4304 controlled by the `set remote noack-packet' command.
4307 Kill the process with the specified process ID. Use this in preference
4308 to `k' when multiprocess protocol extensions are supported.
4311 Obtains additional operating system information
4315 Read or write additional signal information.
4317 * Removed remote protocol undocumented extension
4319 An undocumented extension to the remote protocol's `S' stop reply
4320 packet that permitted the stub to pass a process id was removed.
4321 Remote servers should use the `T' stop reply packet instead.
4323 * GDB now supports multiple function calling conventions according to the
4324 DWARF-2 DW_AT_calling_convention function attribute.
4326 * The SH target utilizes the aforementioned change to distinguish between gcc
4327 and Renesas calling convention. It also adds the new CLI commands
4328 `set/show sh calling-convention'.
4330 * GDB can now read compressed debug sections, as produced by GNU gold
4331 with the --compress-debug-sections=zlib flag.
4333 * 64-bit core files are now supported on AIX.
4335 * Thread switching is now supported on Tru64.
4337 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4338 which will be allocated using malloc later in program execution.
4340 * The qXfer:libraries:read remote protocol packet now allows passing a
4341 list of section offsets.
4343 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4344 conditions handling signals delivered during attach or thread creation
4345 have also been fixed.
4347 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4348 From the user's standpoint, all unqualified instances of True and False
4349 are treated as the standard definitions, regardless of context.
4351 * GDB now parses C++ symbol and type names more flexibly. For
4354 template<typename T> class C { };
4357 GDB will now correctly handle all of:
4359 ptype C<char const *>
4360 ptype C<char const*>
4361 ptype C<const char *>
4362 ptype C<const char*>
4364 * New features in the GDB remote stub, gdbserver
4366 - The "--wrapper" command-line argument tells gdbserver to use a
4367 wrapper program to launch programs for debugging.
4369 - On PowerPC and S/390 targets, it is now possible to use a single
4370 gdbserver executable to debug both 32-bit and 64-bit programs.
4371 (This requires gdbserver itself to be built as a 64-bit executable.)
4373 - gdbserver uses the new noack protocol mode for TCP connections to
4374 reduce communications latency, if also supported and enabled in GDB.
4376 - Support for the sparc64-linux-gnu target is now included in
4379 - The amd64-linux build of gdbserver now supports debugging both
4380 32-bit and 64-bit programs.
4382 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4383 now support hardware watchpoints, and will use them automatically
4388 GDB now has support for scripting using Python. Whether this is
4389 available is determined at configure time.
4391 New GDB commands can now be written in Python.
4393 * Ada tasking support
4395 Ada tasks can now be inspected in GDB. The following commands have
4399 Print the list of Ada tasks.
4401 Print detailed information about task number N.
4403 Print the task number of the current task.
4405 Switch the context of debugging to task number N.
4407 * Support for user-defined prefixed commands. The "define" command can
4408 add new commands to existing prefixes, e.g. "target".
4410 * Multi-inferior, multi-process debugging.
4412 GDB now has generalized support for multi-inferior debugging. See
4413 "Debugging Multiple Inferiors" in the manual for more information.
4414 Although availability still depends on target support, the command
4415 set is more uniform now. The GNU/Linux specific multi-forks support
4416 has been migrated to this new framework. This implied some user
4417 visible changes; see "New commands" and also "Removed commands"
4420 * Target descriptions can now describe the target OS ABI. See the
4421 "Target Description Format" section in the user manual for more
4424 * Target descriptions can now describe "compatible" architectures
4425 to indicate that the target can execute applications for a different
4426 architecture in addition to those for the main target architecture.
4427 See the "Target Description Format" section in the user manual for
4430 * Multi-architecture debugging.
4432 GDB now includes general supports for debugging applications on
4433 hybrid systems that use more than one single processor architecture
4434 at the same time. Each such hybrid architecture still requires
4435 specific support to be added. The only hybrid architecture supported
4436 in this version of GDB is the Cell Broadband Engine.
4438 * GDB now supports integrated debugging of Cell/B.E. applications that
4439 use both the PPU and SPU architectures. To enable support for hybrid
4440 Cell/B.E. debugging, you need to configure GDB to support both the
4441 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4442 --enable-targets configure option.
4444 * Non-stop mode debugging.
4446 For some targets, GDB now supports an optional mode of operation in
4447 which you can examine stopped threads while other threads continue
4448 to execute freely. This is referred to as non-stop mode, with the
4449 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4450 section in the user manual for more information.
4452 To be able to support remote non-stop debugging, a remote stub needs
4453 to implement the non-stop mode remote protocol extensions, as
4454 described in the "Remote Non-Stop" section of the user manual. The
4455 GDB remote stub, gdbserver, has been adjusted to support these
4456 extensions on linux targets.
4458 * New commands (for set/show, see "New options" below)
4460 catch syscall [NAME(S) | NUMBER(S)]
4461 Catch system calls. Arguments, which should be names of system
4462 calls or their numbers, mean catch only those syscalls. Without
4463 arguments, every syscall will be caught. When the inferior issues
4464 any of the specified syscalls, GDB will stop and announce the system
4465 call, both when it is called and when its call returns. This
4466 feature is currently available with a native GDB running on the
4467 Linux Kernel, under the following architectures: x86, x86_64,
4468 PowerPC and PowerPC64.
4470 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4472 Search memory for a sequence of bytes.
4474 maint set python print-stack
4475 maint show python print-stack
4476 Show a stack trace when an error is encountered in a Python script.
4479 Invoke CODE by passing it to the Python interpreter.
4484 These allow macros to be defined, undefined, and listed
4488 Show operating system information about processes.
4491 List the inferiors currently under GDB's control.
4494 Switch focus to inferior number NUM.
4497 Detach from inferior number NUM.
4500 Kill inferior number NUM.
4504 set spu stop-on-load
4505 show spu stop-on-load
4506 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4508 set spu auto-flush-cache
4509 show spu auto-flush-cache
4510 Control whether to automatically flush the software-managed cache
4511 during Cell/B.E. debugging.
4513 set sh calling-convention
4514 show sh calling-convention
4515 Control the calling convention used when calling SH target functions.
4518 show debug timestamp
4519 Control display of timestamps with GDB debugging output.
4521 set disassemble-next-line
4522 show disassemble-next-line
4523 Control display of disassembled source lines or instructions when
4526 set remote noack-packet
4527 show remote noack-packet
4528 Set/show the use of remote protocol QStartNoAckMode packet. See above
4529 under "New remote packets."
4531 set remote query-attached-packet
4532 show remote query-attached-packet
4533 Control use of remote protocol `qAttached' (query-attached) packet.
4535 set remote read-siginfo-object
4536 show remote read-siginfo-object
4537 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4540 set remote write-siginfo-object
4541 show remote write-siginfo-object
4542 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4545 set remote reverse-continue
4546 show remote reverse-continue
4547 Control use of remote protocol 'bc' (reverse-continue) packet.
4549 set remote reverse-step
4550 show remote reverse-step
4551 Control use of remote protocol 'bs' (reverse-step) packet.
4553 set displaced-stepping
4554 show displaced-stepping
4555 Control displaced stepping mode. Displaced stepping is a way to
4556 single-step over breakpoints without removing them from the debuggee.
4557 Also known as "out-of-line single-stepping".
4560 show debug displaced
4561 Control display of debugging info for displaced stepping.
4563 maint set internal-error
4564 maint show internal-error
4565 Control what GDB does when an internal error is detected.
4567 maint set internal-warning
4568 maint show internal-warning
4569 Control what GDB does when an internal warning is detected.
4574 Use a wrapper program to launch programs for debugging.
4576 set multiple-symbols (all|ask|cancel)
4577 show multiple-symbols
4578 The value of this variable can be changed to adjust the debugger behavior
4579 when an expression or a breakpoint location contains an ambiguous symbol
4580 name (an overloaded function name, for instance).
4582 set breakpoint always-inserted
4583 show breakpoint always-inserted
4584 Keep breakpoints always inserted in the target, as opposed to inserting
4585 them when resuming the target, and removing them when the target stops.
4586 This option can improve debugger performance on slow remote targets.
4588 set arm fallback-mode (arm|thumb|auto)
4589 show arm fallback-mode
4590 set arm force-mode (arm|thumb|auto)
4592 These commands control how ARM GDB determines whether instructions
4593 are ARM or Thumb. The default for both settings is auto, which uses
4594 the current CPSR value for instructions without symbols; previous
4595 versions of GDB behaved as if "set arm fallback-mode arm".
4597 set disable-randomization
4598 show disable-randomization
4599 Standalone programs run with the virtual address space randomization enabled
4600 by default on some platforms. This option keeps the addresses stable across
4601 multiple debugging sessions.
4605 Control whether other threads are stopped or not when some thread hits
4610 Requests that asynchronous execution is enabled in the target, if available.
4611 In this case, it's possible to resume target in the background, and interact
4612 with GDB while the target is running. "show target-async" displays the
4613 current state of asynchronous execution of the target.
4615 set target-wide-charset
4616 show target-wide-charset
4617 The target-wide-charset is the name of the character set that GDB
4618 uses when printing characters whose type is wchar_t.
4620 set tcp auto-retry (on|off)
4622 set tcp connect-timeout
4623 show tcp connect-timeout
4624 These commands allow GDB to retry failed TCP connections to a remote stub
4625 with a specified timeout period; this is useful if the stub is launched
4626 in parallel with GDB but may not be ready to accept connections immediately.
4628 set libthread-db-search-path
4629 show libthread-db-search-path
4630 Control list of directories which GDB will search for appropriate
4633 set schedule-multiple (on|off)
4634 show schedule-multiple
4635 Allow GDB to resume all threads of all processes or only threads of
4636 the current process.
4640 Use more aggressive caching for accesses to the stack. This improves
4641 performance of remote debugging (particularly backtraces) without
4642 affecting correctness.
4644 set interactive-mode (on|off|auto)
4645 show interactive-mode
4646 Control whether GDB runs in interactive mode (on) or not (off).
4647 When in interactive mode, GDB waits for the user to answer all
4648 queries. Otherwise, GDB does not wait and assumes the default
4649 answer. When set to auto (the default), GDB determines which
4650 mode to use based on the stdin settings.
4655 For program forks, this is replaced by the new more generic `info
4656 inferiors' command. To list checkpoints, you can still use the
4657 `info checkpoints' command, which was an alias for the `info forks'
4661 Replaced by the new `inferior' command. To switch between
4662 checkpoints, you can still use the `restart' command, which was an
4663 alias for the `fork' command.
4666 This is removed, since some targets don't have a notion of
4667 processes. To switch between processes, you can still use the
4668 `inferior' command using GDB's own inferior number.
4671 For program forks, this is replaced by the new more generic `kill
4672 inferior' command. To delete a checkpoint, you can still use the
4673 `delete checkpoint' command, which was an alias for the `delete
4677 For program forks, this is replaced by the new more generic `detach
4678 inferior' command. To detach a checkpoint, you can still use the
4679 `detach checkpoint' command, which was an alias for the `detach
4682 * New native configurations
4684 x86/x86_64 Darwin i[34567]86-*-darwin*
4686 x86_64 MinGW x86_64-*-mingw*
4690 Lattice Mico32 lm32-*
4691 x86 DICOS i[34567]86-*-dicos*
4692 x86_64 DICOS x86_64-*-dicos*
4695 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4696 (mingw32ce) debugging.
4702 These commands were actually not implemented on any target.
4704 *** Changes in GDB 6.8
4706 * New native configurations
4708 NetBSD/hppa hppa*-*netbsd*
4709 Xtensa GNU/Linux xtensa*-*-linux*
4713 NetBSD/hppa hppa*-*-netbsd*
4714 Xtensa GNU/Linux xtensa*-*-linux*
4716 * Change in command line behavior -- corefiles vs. process ids.
4718 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4719 attaching to process NUMBER fails, GDB no longer attempts to open a
4720 core file named NUMBER. Attaching to a program using the -c option
4721 is no longer supported. Instead, use the '-p' or '--pid' options.
4723 * GDB can now be built as a native debugger for debugging Windows x86
4724 (mingw32) Portable Executable (PE) programs.
4726 * Pending breakpoints no longer change their number when their address
4729 * GDB now supports breakpoints with multiple locations,
4730 including breakpoints on C++ constructors, inside C++ templates,
4731 and in inlined functions.
4733 * GDB's ability to debug optimized code has been improved. GDB more
4734 accurately identifies function bodies and lexical blocks that occupy
4735 more than one contiguous range of addresses.
4737 * Target descriptions can now describe registers for PowerPC.
4739 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4740 registers on PowerPC targets.
4742 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4743 targets even when the libthread_db library is not available.
4745 * The GDB remote stub, gdbserver, now supports the new file transfer
4746 commands (remote put, remote get, and remote delete).
4748 * The GDB remote stub, gdbserver, now supports run and attach in
4749 extended-remote mode.
4751 * hppa*64*-*-hpux11* target broken
4752 The debugger is unable to start a program and fails with the following
4753 error: "Error trying to get information about dynamic linker".
4754 The gdb-6.7 release is also affected.
4756 * GDB now supports the --enable-targets= configure option to allow
4757 building a single GDB executable that supports multiple remote
4758 target architectures.
4760 * GDB now supports debugging C and C++ programs which use the
4761 Decimal Floating Point extension. In addition, the PowerPC target
4762 now has a set of pseudo-registers to inspect decimal float values
4763 stored in two consecutive float registers.
4765 * The -break-insert MI command can optionally create pending
4768 * Improved support for debugging Ada
4769 Many improvements to the Ada language support have been made. These
4771 - Better support for Ada2005 interface types
4772 - Improved handling of arrays and slices in general
4773 - Better support for Taft-amendment types
4774 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4776 - Improved command completion in Ada
4779 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4784 set print frame-arguments (all|scalars|none)
4785 show print frame-arguments
4786 The value of this variable can be changed to control which argument
4787 values should be printed by the debugger when displaying a frame.
4792 Transfer files to and from a remote target, and delete remote files.
4799 Transfer files to and from a remote target, and delete remote files.
4801 * New remote packets
4808 Open, close, read, write, and delete files on the remote system.
4811 Attach to an existing process on the remote system, in extended-remote
4815 Run a new process on the remote system, in extended-remote mode.
4817 *** Changes in GDB 6.7
4819 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4820 bfd, libiberty and opcodes, as revealed by static analysis donated by
4821 Coverity, Inc. (http://scan.coverity.com).
4823 * When looking up multiply-defined global symbols, GDB will now prefer the
4824 symbol definition in the current shared library if it was built using the
4825 -Bsymbolic linker option.
4827 * When the Text User Interface (TUI) is not configured, GDB will now
4828 recognize the -tui command-line option and print a message that the TUI
4831 * The GDB remote stub, gdbserver, now has lower overhead for high
4832 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4834 * GDB for MIPS targets now autodetects whether a remote target provides
4835 32-bit or 64-bit register values.
4837 * Support for C++ member pointers has been improved.
4839 * GDB now understands XML target descriptions, which specify the
4840 target's overall architecture. GDB can read a description from
4841 a local file or over the remote serial protocol.
4843 * Vectors of single-byte data use a new integer type which is not
4844 automatically displayed as character or string data.
4846 * The /s format now works with the print command. It displays
4847 arrays of single-byte integers and pointers to single-byte integers
4850 * Target descriptions can now describe target-specific registers,
4851 for architectures which have implemented the support (currently
4852 only ARM, M68K, and MIPS).
4854 * GDB and the GDB remote stub, gdbserver, now support the XScale
4857 * The GDB remote stub, gdbserver, has been updated to support
4858 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4859 has been rewritten to use the standard GDB remote protocol.
4861 * GDB can now step into C++ functions which are called through thunks.
4863 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4865 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4866 layout. It also supports a TextSeg= and DataSeg= response when only
4867 segment base addresses (rather than offsets) are available.
4869 * The /i format now outputs any trailing branch delay slot instructions
4870 immediately following the last instruction within the count specified.
4872 * The GDB remote protocol "T" stop reply packet now supports a
4873 "library" response. Combined with the new "qXfer:libraries:read"
4874 packet, this response allows GDB to debug shared libraries on targets
4875 where the operating system manages the list of loaded libraries (e.g.
4876 Windows and SymbianOS).
4878 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4879 (DLLs) on Windows and Windows CE targets.
4881 * GDB now supports a faster verification that a .debug file matches its binary
4882 according to its build-id signature, if the signature is present.
4888 Enable or disable hardware flow control (RTS/CTS) on the serial port
4889 when debugging using remote targets.
4891 set mem inaccessible-by-default
4892 show mem inaccessible-by-default
4893 If the target supplies a memory map, for instance via the remote
4894 protocol's "qXfer:memory-map:read" packet, setting this variable
4895 prevents GDB from accessing memory outside the memory map. This
4896 is useful for targets with memory mapped registers or which react
4897 badly to accesses of unmapped address space.
4899 set breakpoint auto-hw
4900 show breakpoint auto-hw
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 lets GDB use hardware breakpoints automatically for memory regions
4904 where it can not use software breakpoints. This covers both the
4905 "break" command and internal breakpoints used for other commands
4906 including "next" and "finish".
4909 catch exception unhandled
4910 Stop the program execution when Ada exceptions are raised.
4913 Stop the program execution when an Ada assertion failed.
4917 Set an alternate system root for target files. This is a more
4918 general version of "set solib-absolute-prefix", which is now
4919 an alias to "set sysroot".
4922 Provide extended SPU facility status information. This set of
4923 commands is available only when debugging the Cell/B.E. SPU
4926 * New native configurations
4928 OpenBSD/sh sh*-*openbsd*
4931 unset tdesc filename
4933 Use the specified local file as an XML target description, and do
4934 not query the target for its built-in description.
4938 OpenBSD/sh sh*-*-openbsd*
4939 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4940 Toshiba Media Processor mep-elf
4942 * New remote packets
4945 Ignore the specified signals; pass them directly to the debugged program
4946 without stopping other threads or reporting them to GDB.
4948 qXfer:features:read:
4949 Read an XML target description from the target, which describes its
4954 Read or write contents of an spufs file on the target system. These
4955 packets are available only on the Cell/B.E. SPU architecture.
4957 qXfer:libraries:read:
4958 Report the loaded shared libraries. Combined with new "T" packet
4959 response, this packet allows GDB to debug shared libraries on
4960 targets where the operating system manages the list of loaded
4961 libraries (e.g. Windows and SymbianOS).
4965 Support for these obsolete configurations has been removed.
4973 i[34567]86-*-lynxos*
4974 i[34567]86-*-netware*
4975 i[34567]86-*-sco3.2v5*
4976 i[34567]86-*-sco3.2v4*
4978 i[34567]86-*-sysv4.2*
4981 i[34567]86-*-unixware2*
4982 i[34567]86-*-unixware*
4991 * Other removed features
4998 Various m68k-only ROM monitors.
5005 Various Renesas ROM monitors and debugging interfaces for SH and
5010 Support for a Macraigor serial interface to on-chip debugging.
5011 GDB does not directly support the newer parallel or USB
5016 A debug information format. The predecessor to DWARF 2 and
5017 DWARF 3, which are still supported.
5019 Support for the HP aCC compiler on HP-UX/PA-RISC
5021 SOM-encapsulated symbolic debugging information, automatic
5022 invocation of pxdb, and the aCC custom C++ ABI. This does not
5023 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5024 with aCC can still be debugged on an assembly level.
5026 MIPS ".pdr" sections
5028 A MIPS-specific format used to describe stack frame layout
5029 in debugging information.
5033 GDB could work with an older version of Guile to debug
5034 the interpreter and Scheme programs running in it.
5036 set mips stack-arg-size
5037 set mips saved-gpreg-size
5039 Use "set mips abi" to control parameter passing for MIPS.
5041 *** Changes in GDB 6.6
5046 Cell Broadband Engine SPU spu-elf
5048 * GDB can now be configured as a cross-debugger targeting native Windows
5049 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5050 running on a Windows system over TCP/IP to debug Windows programs.
5052 * The GDB remote stub, gdbserver, has been updated to support Windows and
5053 Cygwin debugging. Both single-threaded and multi-threaded programs are
5056 * The "set trust-readonly-sections" command works again. This command was
5057 broken in GDB 6.3, 6.4, and 6.5.
5059 * The "load" command now supports writing to flash memory, if the remote
5060 stub provides the required support.
5062 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5063 longer requires symbolic debug information (e.g. DWARF-2).
5068 unset substitute-path
5069 show substitute-path
5070 Manage a list of substitution rules that GDB uses to rewrite the name
5071 of the directories where the sources are located. This can be useful
5072 for instance when the sources were moved to a different location
5073 between compilation and debugging.
5077 Print each CLI command as it is executed. Each command is prefixed with
5078 a number of `+' symbols representing the nesting depth.
5079 The source command now has a `-v' option to enable the same feature.
5083 The ARM Demon monitor support (RDP protocol, "target rdp").
5085 Kernel Object Display, an embedded debugging feature which only worked with
5086 an obsolete version of Cisco IOS.
5088 The 'set download-write-size' and 'show download-write-size' commands.
5090 * New remote packets
5093 Tell a stub about GDB client features, and request remote target features.
5094 The first feature implemented is PacketSize, which allows the target to
5095 specify the size of packets it can handle - to minimize the number of
5096 packets required and improve performance when connected to a remote
5100 Fetch an OS auxilliary vector from the remote stub. This packet is a
5101 more efficient replacement for qPart:auxv:read.
5103 qXfer:memory-map:read:
5104 Fetch a memory map from the remote stub, including information about
5105 RAM, ROM, and flash memory devices.
5110 Erase and program a flash memory device.
5112 * Removed remote packets
5115 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5116 used it, and only gdbserver implemented it.
5118 *** Changes in GDB 6.5
5122 Renesas M32C/M16C m32c-elf
5124 Morpho Technologies ms1 ms1-elf
5128 init-if-undefined Initialize a convenience variable, but
5129 only if it doesn't already have a value.
5131 The following commands are presently only implemented for native GNU/Linux:
5133 checkpoint Save a snapshot of the program state.
5135 restart <n> Return the program state to a
5136 previously saved state.
5138 info checkpoints List currently saved checkpoints.
5140 delete-checkpoint <n> Delete a previously saved checkpoint.
5142 set|show detach-on-fork Tell gdb whether to detach from a newly
5143 forked process, or to keep debugging it.
5145 info forks List forks of the user program that
5146 are available to be debugged.
5148 fork <n> Switch to debugging one of several
5149 forks of the user program that are
5150 available to be debugged.
5152 delete-fork <n> Delete a fork from the list of forks
5153 that are available to be debugged (and
5154 kill the forked process).
5156 detach-fork <n> Delete a fork from the list of forks
5157 that are available to be debugged (and
5158 allow the process to continue).
5162 Morpho Technologies ms2 ms1-elf
5164 * Improved Windows host support
5166 GDB now builds as a cross debugger hosted on i686-mingw32, including
5167 native console support, and remote communications using either
5168 network sockets or serial ports.
5170 * Improved Modula-2 language support
5172 GDB can now print most types in the Modula-2 syntax. This includes:
5173 basic types, set types, record types, enumerated types, range types,
5174 pointer types and ARRAY types. Procedure var parameters are correctly
5175 printed and hexadecimal addresses and character constants are also
5176 written in the Modula-2 syntax. Best results can be obtained by using
5177 GNU Modula-2 together with the -gdwarf-2 command line option.
5181 The ARM rdi-share module.
5183 The Netware NLM debug server.
5185 *** Changes in GDB 6.4
5187 * New native configurations
5189 OpenBSD/arm arm*-*-openbsd*
5190 OpenBSD/mips64 mips64-*-openbsd*
5194 Morpho Technologies ms1 ms1-elf
5196 * New command line options
5198 --batch-silent As for --batch, but totally silent.
5199 --return-child-result The debugger will exist with the same value
5200 the child (debugged) program exited with.
5201 --eval-command COMMAND, -ex COMMAND
5202 Execute a single GDB CLI command. This may be
5203 specified multiple times and in conjunction
5204 with the --command (-x) option.
5206 * Deprecated commands removed
5208 The following commands, that were deprecated in 2000, have been
5212 set|show arm disassembly-flavor set|show arm disassembler
5213 othernames set arm disassembler
5214 set|show remotedebug set|show debug remote
5215 set|show archdebug set|show debug arch
5216 set|show eventdebug set|show debug event
5219 * New BSD user-level threads support
5221 It is now possible to debug programs using the user-level threads
5222 library on OpenBSD and FreeBSD. Currently supported (target)
5225 FreeBSD/amd64 x86_64-*-freebsd*
5226 FreeBSD/i386 i386-*-freebsd*
5227 OpenBSD/i386 i386-*-openbsd*
5229 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5230 are not yet supported.
5232 * New support for Matsushita MN10300 w/sim added
5233 (Work in progress). mn10300-elf.
5235 * REMOVED configurations and files
5237 VxWorks and the XDR protocol *-*-vxworks
5238 Motorola MCORE mcore-*-*
5239 National Semiconductor NS32000 ns32k-*-*
5241 * New "set print array-indexes" command
5243 After turning this setting "on", GDB prints the index of each element
5244 when displaying arrays. The default is "off" to preserve the previous
5247 * VAX floating point support
5249 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5251 * User-defined command support
5253 In addition to using $arg0..$arg9 for argument passing, it is now possible
5254 to use $argc to determine now many arguments have been passed. See the
5255 section on user-defined commands in the user manual for more information.
5257 *** Changes in GDB 6.3:
5259 * New command line option
5261 GDB now accepts -l followed by a number to set the timeout for remote
5264 * GDB works with GCC -feliminate-dwarf2-dups
5266 GDB now supports a more compact representation of DWARF-2 debug
5267 information using DW_FORM_ref_addr references. These are produced
5268 by GCC with the option -feliminate-dwarf2-dups and also by some
5269 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5270 to use -feliminate-dwarf2-dups.
5272 * Internationalization
5274 When supported by the host system, GDB will be built with
5275 internationalization (libintl). The task of marking up the sources is
5276 continued, we're looking forward to our first translation.
5280 Initial support for debugging programs compiled with the GNAT
5281 implementation of the Ada programming language has been integrated
5282 into GDB. In this release, support is limited to expression evaluation.
5284 * New native configurations
5286 GNU/Linux/m32r m32r-*-linux-gnu
5290 GDB's remote protocol now includes support for the 'p' packet. This
5291 packet is used to fetch individual registers from a remote inferior.
5293 * END-OF-LIFE registers[] compatibility module
5295 GDB's internal register infrastructure has been completely rewritten.
5296 The new infrastructure making possible the implementation of key new
5297 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5300 GDB 6.3 will be the last release to include the registers[]
5301 compatibility module that allowed out-of-date configurations to
5302 continue to work. This change directly impacts the following
5312 powerpc bdm protocol
5314 Unless there is activity to revive these configurations, they will be
5315 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5317 * OBSOLETE configurations and files
5319 Configurations that have been declared obsolete in this release have
5320 been commented out. Unless there is activity to revive these
5321 configurations, the next release of GDB will have their sources
5322 permanently REMOVED.
5331 *** Changes in GDB 6.2.1:
5333 * MIPS `break main; run' gave an heuristic-fence-post warning
5335 When attempting to run even a simple program, a warning about
5336 heuristic-fence-post being hit would be reported. This problem has
5339 * MIPS IRIX 'long double' crashed GDB
5341 When examining a long double variable, GDB would get a segmentation
5342 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5343 IRIX long double values).
5347 A bug in the VAX stack code was causing problems with the "next"
5348 command. This problem has been fixed.
5350 *** Changes in GDB 6.2:
5352 * Fix for ``many threads''
5354 On GNU/Linux systems that use the NPTL threads library, a program
5355 rapidly creating and deleting threads would confuse GDB leading to the
5358 ptrace: No such process.
5359 thread_db_get_info: cannot get thread info: generic error
5361 This problem has been fixed.
5363 * "-async" and "-noasync" options removed.
5365 Support for the broken "-noasync" option has been removed (it caused
5368 * New ``start'' command.
5370 This command runs the program until the beginning of the main procedure.
5372 * New BSD Kernel Data Access Library (libkvm) interface
5374 Using ``target kvm'' it is now possible to debug kernel core dumps and
5375 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5376 platforms. Currently supported (native-only) configurations are:
5378 FreeBSD/amd64 x86_64-*-freebsd*
5379 FreeBSD/i386 i?86-*-freebsd*
5380 NetBSD/i386 i?86-*-netbsd*
5381 NetBSD/m68k m68*-*-netbsd*
5382 NetBSD/sparc sparc-*-netbsd*
5383 OpenBSD/amd64 x86_64-*-openbsd*
5384 OpenBSD/i386 i?86-*-openbsd*
5385 OpenBSD/m68k m68*-openbsd*
5386 OpenBSD/sparc sparc-*-openbsd*
5388 * Signal trampoline code overhauled
5390 Many generic problems with GDB's signal handling code have been fixed.
5391 These include: backtraces through non-contiguous stacks; recognition
5392 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5393 call; backtrace through a signal trampoline; step into and out of
5394 signal handlers; and single-stepping in the signal trampoline.
5396 Please note that kernel bugs are a limiting factor here. These
5397 features have been shown to work on an s390 GNU/Linux system that
5398 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5400 * Cygwin support for DWARF 2 added.
5402 * New native configurations
5404 GNU/Linux/hppa hppa*-*-linux*
5405 OpenBSD/hppa hppa*-*-openbsd*
5406 OpenBSD/m68k m68*-*-openbsd*
5407 OpenBSD/m88k m88*-*-openbsd*
5408 OpenBSD/powerpc powerpc-*-openbsd*
5409 NetBSD/vax vax-*-netbsd*
5410 OpenBSD/vax vax-*-openbsd*
5412 * END-OF-LIFE frame compatibility module
5414 GDB's internal frame infrastructure has been completely rewritten.
5415 The new infrastructure making it possible to support key new features
5416 including DWARF 2 Call Frame Information. To aid in the task of
5417 migrating old configurations to this new infrastructure, a
5418 compatibility module, that allowed old configurations to continue to
5419 work, was also included.
5421 GDB 6.2 will be the last release to include this frame compatibility
5422 module. This change directly impacts the following configurations:
5432 Unless there is activity to revive these configurations, they will be
5433 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5435 * REMOVED configurations and files
5437 Sun 3, running SunOS 3 m68*-*-sunos3*
5438 Sun 3, running SunOS 4 m68*-*-sunos4*
5439 Sun 2, running SunOS 3 m68000-*-sunos3*
5440 Sun 2, running SunOS 4 m68000-*-sunos4*
5441 Motorola 680x0 running LynxOS m68*-*-lynxos*
5442 AT&T 3b1/Unix pc m68*-att-*
5443 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5444 decstation mips-dec-* mips-little-*
5445 riscos mips-*-riscos* mips-*-sysv*
5446 sonymips mips-sony-*
5447 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5449 *** Changes in GDB 6.1.1:
5451 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5453 The TUI (Text-mode User Interface) is now built as part of a default
5454 GDB configuration. It is enabled by either selecting the TUI with the
5455 command line option "-i=tui" or by running the separate "gdbtui"
5456 program. For more information on the TUI, see the manual "Debugging
5459 * Pending breakpoint support (also included in GDB 6.1)
5461 Support has been added to allow you to specify breakpoints in shared
5462 libraries that have not yet been loaded. If a breakpoint location
5463 cannot be found, and the "breakpoint pending" option is set to auto,
5464 GDB queries you if you wish to make the breakpoint pending on a future
5465 shared-library load. If and when GDB resolves the breakpoint symbol,
5466 the pending breakpoint is removed as one or more regular breakpoints
5469 Pending breakpoints are very useful for GCJ Java debugging.
5471 * Fixed ISO-C build problems
5473 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5474 non ISO-C code that stopped them being built using a more strict ISO-C
5475 compiler (e.g., IBM's C compiler).
5477 * Fixed build problem on IRIX 5
5479 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5480 wasn't able to compile compile on an IRIX 5 system.
5482 * Added execute permission to gdb/gdbserver/configure
5484 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5485 permission. This bug would cause configure to fail on a number of
5486 systems (Solaris, IRIX). Ref: server/519.
5488 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5490 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5491 has been updated to use constant array sizes.
5493 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5495 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5496 its generated DWARF Call Frame Info. This encoding was causing GDB to
5497 panic, that panic has been fixed. Ref: gdb/1628.
5499 * Fixed a problem when examining parameters in shared library code.
5501 When examining parameters in optimized shared library code generated
5502 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5503 not available''. GDB now correctly displays the variable's value.
5505 *** Changes in GDB 6.1:
5507 * Removed --with-mmalloc
5509 Support for the mmalloc memory manager has been removed, as it
5510 conflicted with the internal gdb byte cache.
5512 * Changes in AMD64 configurations
5514 The AMD64 target now includes the %cs and %ss registers. As a result
5515 the AMD64 remote protocol has changed; this affects the floating-point
5516 and SSE registers. If you rely on those registers for your debugging,
5517 you should upgrade gdbserver on the remote side.
5519 * Revised SPARC target
5521 The SPARC target has been completely revised, incorporating the
5522 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5523 support for LynxOS and SunOS 4 has been dropped. Calling functions
5524 from within GDB on operating systems with a non-executable stack
5525 (Solaris, OpenBSD) now works.
5529 GDB has a new C++ demangler which does a better job on the mangled
5530 names generated by current versions of g++. It also runs faster, so
5531 with this and other changes gdb should now start faster on large C++
5534 * DWARF 2 Location Expressions
5536 GDB support for location expressions has been extended to support function
5537 arguments and frame bases. Older versions of GDB could crash when they
5540 * C++ nested types and namespaces
5542 GDB's support for nested types and namespaces in C++ has been
5543 improved, especially if you use the DWARF 2 debugging format. (This
5544 is the default for recent versions of GCC on most platforms.)
5545 Specifically, if you have a class "Inner" defined within a class or
5546 namespace "Outer", then GDB realizes that the class's name is
5547 "Outer::Inner", not simply "Inner". This should greatly reduce the
5548 frequency of complaints about not finding RTTI symbols. In addition,
5549 if you are stopped at inside of a function defined within a namespace,
5550 GDB modifies its name lookup accordingly.
5552 * New native configurations
5554 NetBSD/amd64 x86_64-*-netbsd*
5555 OpenBSD/amd64 x86_64-*-openbsd*
5556 OpenBSD/alpha alpha*-*-openbsd*
5557 OpenBSD/sparc sparc-*-openbsd*
5558 OpenBSD/sparc64 sparc64-*-openbsd*
5560 * New debugging protocols
5562 M32R with SDI protocol m32r-*-elf*
5564 * "set prompt-escape-char" command deleted.
5566 The command "set prompt-escape-char" has been deleted. This command,
5567 and its very obscure effect on GDB's prompt, was never documented,
5568 tested, nor mentioned in the NEWS file.
5570 * OBSOLETE configurations and files
5572 Configurations that have been declared obsolete in this release have
5573 been commented out. Unless there is activity to revive these
5574 configurations, the next release of GDB will have their sources
5575 permanently REMOVED.
5577 Sun 3, running SunOS 3 m68*-*-sunos3*
5578 Sun 3, running SunOS 4 m68*-*-sunos4*
5579 Sun 2, running SunOS 3 m68000-*-sunos3*
5580 Sun 2, running SunOS 4 m68000-*-sunos4*
5581 Motorola 680x0 running LynxOS m68*-*-lynxos*
5582 AT&T 3b1/Unix pc m68*-att-*
5583 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5584 decstation mips-dec-* mips-little-*
5585 riscos mips-*-riscos* mips-*-sysv*
5586 sonymips mips-sony-*
5587 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5589 * REMOVED configurations and files
5591 SGI Irix-4.x mips-sgi-irix4 or iris4
5592 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5593 Z8000 simulator z8k-zilog-none or z8ksim
5594 Matsushita MN10200 w/simulator mn10200-*-*
5595 H8/500 simulator h8500-hitachi-hms or h8500hms
5596 HP/PA running BSD hppa*-*-bsd*
5597 HP/PA running OSF/1 hppa*-*-osf*
5598 HP/PA Pro target hppa*-*-pro*
5599 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5600 386BSD i[3456]86-*-bsd*
5601 Sequent family i[3456]86-sequent-sysv4*
5602 i[3456]86-sequent-sysv*
5603 i[3456]86-sequent-bsd*
5604 SPARC running LynxOS sparc-*-lynxos*
5605 SPARC running SunOS 4 sparc-*-sunos4*
5606 Tsqware Sparclet sparclet-*-*
5607 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5609 *** Changes in GDB 6.0:
5613 Support for debugging the Objective-C programming language has been
5614 integrated into GDB.
5616 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5618 DWARF 2's Call Frame Information makes available compiler generated
5619 information that more exactly describes the program's run-time stack.
5620 By using this information, GDB is able to provide more robust stack
5623 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5624 have been updated to use a new backtrace mechanism which includes
5625 DWARF 2 CFI support.
5629 GDB's remote protocol has been extended to include support for hosted
5630 file I/O (where the remote target uses GDB's file system). See GDB's
5631 remote protocol documentation for details.
5633 * All targets using the new architecture framework.
5635 All of GDB's targets have been updated to use the new internal
5636 architecture framework. The way is now open for future GDB releases
5637 to include cross-architecture native debugging support (i386 on amd64,
5640 * GNU/Linux's Thread Local Storage (TLS)
5642 GDB now includes support for for the GNU/Linux implementation of
5643 per-thread variables.
5645 * GNU/Linux's Native POSIX Thread Library (NPTL)
5647 GDB's thread code has been updated to work with either the new
5648 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5650 * Separate debug info.
5652 GDB, in conjunction with BINUTILS, now supports a mechanism for
5653 automatically loading debug information from a separate file. Instead
5654 of shipping full debug and non-debug versions of system libraries,
5655 system integrators can now instead ship just the stripped libraries
5656 and optional debug files.
5658 * DWARF 2 Location Expressions
5660 DWARF 2 Location Expressions allow the compiler to more completely
5661 describe the location of variables (even in optimized code) to the
5664 GDB now includes preliminary support for location expressions (support
5665 for DW_OP_piece is still missing).
5669 A number of long standing bugs that caused GDB to die while starting a
5670 Java application have been fixed. GDB's Java support is now
5671 considered "useable".
5673 * GNU/Linux support for fork, vfork, and exec.
5675 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5676 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5679 * GDB supports logging output to a file
5681 There are two new commands, "set logging" and "show logging", which can be
5682 used to capture GDB's output to a file.
5684 * The meaning of "detach" has changed for gdbserver
5686 The "detach" command will now resume the application, as documented. To
5687 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5690 * d10v, m68hc11 `regs' command deprecated
5692 The `info registers' command has been updated so that it displays the
5693 registers using a format identical to the old `regs' command.
5697 A new command, "maint set profile on/off", has been added. This command can
5698 be used to enable or disable profiling while running GDB, to profile a
5699 session or a set of commands. In addition there is a new configure switch,
5700 "--enable-profiling", which will cause GDB to be compiled with profiling
5701 data, for more informative profiling results.
5703 * Default MI syntax changed to "mi2".
5705 The default MI (machine interface) syntax, enabled by the command line
5706 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5707 "mi1", can be enabled by specifying the option "-i=mi1".
5709 Support for the original "mi0" syntax (included in GDB 5.0) has been
5712 Fix for gdb/192: removed extraneous space when displaying frame level.
5713 Fix for gdb/672: update changelist is now output in mi list format.
5714 Fix for gdb/702: a -var-assign that updates the value now shows up
5715 in a subsequent -var-update.
5717 * New native configurations.
5719 FreeBSD/amd64 x86_64-*-freebsd*
5721 * Multi-arched targets.
5723 HP/PA HPUX11 hppa*-*-hpux*
5724 Renesas M32R/D w/simulator m32r-*-elf*
5726 * OBSOLETE configurations and files
5728 Configurations that have been declared obsolete in this release have
5729 been commented out. Unless there is activity to revive these
5730 configurations, the next release of GDB will have their sources
5731 permanently REMOVED.
5733 Z8000 simulator z8k-zilog-none or z8ksim
5734 Matsushita MN10200 w/simulator mn10200-*-*
5735 H8/500 simulator h8500-hitachi-hms or h8500hms
5736 HP/PA running BSD hppa*-*-bsd*
5737 HP/PA running OSF/1 hppa*-*-osf*
5738 HP/PA Pro target hppa*-*-pro*
5739 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5740 Sequent family i[3456]86-sequent-sysv4*
5741 i[3456]86-sequent-sysv*
5742 i[3456]86-sequent-bsd*
5743 Tsqware Sparclet sparclet-*-*
5744 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5746 * REMOVED configurations and files
5749 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5750 IBM AIX PS/2 i[3456]86-*-aix
5751 i386 running Mach 3.0 i[3456]86-*-mach3*
5752 i386 running Mach i[3456]86-*-mach*
5753 i386 running OSF/1 i[3456]86-*osf1mk*
5754 HP/Apollo 68k Family m68*-apollo*-sysv*,
5756 m68*-hp-bsd*, m68*-hp-hpux*
5757 Argonaut Risc Chip (ARC) arc-*-*
5758 Mitsubishi D30V d30v-*-*
5759 Fujitsu FR30 fr30-*-elf*
5760 OS/9000 i[34]86-*-os9k
5761 I960 with MON960 i960-*-coff
5763 * MIPS $fp behavior changed
5765 The convenience variable $fp, for the MIPS, now consistently returns
5766 the address of the current frame's base. Previously, depending on the
5767 context, $fp could refer to either $sp or the current frame's base
5768 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5769 The GNU Source-Level Debugger''.
5771 *** Changes in GDB 5.3:
5773 * GNU/Linux shared library multi-threaded performance improved.
5775 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5776 `/proc', in preference to `ptrace' for memory reads. This may result
5777 in an improvement in the start-up time of multi-threaded, shared
5778 library applications when run under GDB. One GDB user writes: ``loads
5779 shared libs like mad''.
5781 * ``gdbserver'' now supports multi-threaded applications on some targets
5783 Support for debugging multi-threaded applications which use
5784 the GNU/Linux LinuxThreads package has been added for
5785 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5786 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5788 * GDB now supports C/C++ preprocessor macros.
5790 GDB now expands preprocessor macro invocations in C/C++ expressions,
5791 and provides various commands for showing macro definitions and how
5794 The new command `macro expand EXPRESSION' expands any macro
5795 invocations in expression, and shows the result.
5797 The new command `show macro MACRO-NAME' shows the definition of the
5798 macro named MACRO-NAME, and where it was defined.
5800 Most compilers don't include information about macros in the debugging
5801 information by default. In GCC 3.1, for example, you need to compile
5802 your program with the options `-gdwarf-2 -g3'. If the macro
5803 information is present in the executable, GDB will read it.
5805 * Multi-arched targets.
5807 DEC Alpha (partial) alpha*-*-*
5808 DEC VAX (partial) vax-*-*
5810 National Semiconductor NS32000 (partial) ns32k-*-*
5811 Motorola 68000 (partial) m68k-*-*
5812 Motorola MCORE mcore-*-*
5816 Fujitsu FRV architecture added by Red Hat frv*-*-*
5819 * New native configurations
5821 Alpha NetBSD alpha*-*-netbsd*
5822 SH NetBSD sh*-*-netbsdelf*
5823 MIPS NetBSD mips*-*-netbsd*
5824 UltraSPARC NetBSD sparc64-*-netbsd*
5826 * OBSOLETE configurations and files
5828 Configurations that have been declared obsolete in this release have
5829 been commented out. Unless there is activity to revive these
5830 configurations, the next release of GDB will have their sources
5831 permanently REMOVED.
5833 Mitsubishi D30V d30v-*-*
5834 OS/9000 i[34]86-*-os9k
5835 IBM AIX PS/2 i[3456]86-*-aix
5836 Fujitsu FR30 fr30-*-elf*
5837 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5838 Argonaut Risc Chip (ARC) arc-*-*
5839 i386 running Mach 3.0 i[3456]86-*-mach3*
5840 i386 running Mach i[3456]86-*-mach*
5841 i386 running OSF/1 i[3456]86-*osf1mk*
5842 HP/Apollo 68k Family m68*-apollo*-sysv*,
5844 m68*-hp-bsd*, m68*-hp-hpux*
5845 I960 with MON960 i960-*-coff
5847 * OBSOLETE languages
5849 CHILL, a Pascal like language used by telecommunications companies.
5851 * REMOVED configurations and files
5853 AMD 29k family via UDI a29k-amd-udi, udi29k
5854 A29K VxWorks a29k-*-vxworks
5855 AMD 29000 embedded, using EBMON a29k-none-none
5856 AMD 29000 embedded with COFF a29k-none-coff
5857 AMD 29000 embedded with a.out a29k-none-aout
5859 testsuite/gdb.hp/gdb.threads-hp/ directory
5861 * New command "set max-user-call-depth <nnn>"
5863 This command allows the user to limit the call depth of user-defined
5864 commands. The default is 1024.
5866 * Changes in FreeBSD/i386 native debugging.
5868 Support for the "generate-core-file" has been added.
5870 * New commands "dump", "append", and "restore".
5872 These commands allow data to be copied from target memory
5873 to a bfd-format or binary file (dump and append), and back
5874 from a file into memory (restore).
5876 * Improved "next/step" support on multi-processor Alpha Tru64.
5878 The previous single-step mechanism could cause unpredictable problems,
5879 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5880 of a software single-step mechanism prevents this.
5882 *** Changes in GDB 5.2.1:
5890 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5891 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5892 Fix, by Joel Brobecker imported from mainline.
5894 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5895 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5896 Fix, by Fred Fish, imported from mainline.
5898 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5899 Surprisingly enough, it works now.
5900 By Michal Ludvig, imported from mainline.
5902 i386 hardware watchpoint support:
5903 avoid misses on second run for some targets.
5904 By Pierre Muller, imported from mainline.
5906 *** Changes in GDB 5.2:
5908 * New command "set trust-readonly-sections on[off]".
5910 This command is a hint that tells gdb that read-only sections
5911 really are read-only (ie. that their contents will not change).
5912 In this mode, gdb will go to the object file rather than the
5913 target to read memory from read-only sections (such as ".text").
5914 This can be a significant performance improvement on some
5915 (notably embedded) targets.
5917 * New command "generate-core-file" (or "gcore").
5919 This new gdb command allows the user to drop a core file of the child
5920 process state at any time. So far it's been implemented only for
5921 GNU/Linux and Solaris, but should be relatively easily ported to other
5922 hosts. Argument is core file name (defaults to core.<pid>).
5924 * New command line option
5926 GDB now accepts --pid or -p followed by a process id.
5928 * Change in command line behavior -- corefiles vs. process ids.
5930 There is a subtle behavior in the way in which GDB handles
5931 command line arguments. The first non-flag argument is always
5932 a program to debug, but the second non-flag argument may either
5933 be a corefile or a process id. Previously, GDB would attempt to
5934 open the second argument as a corefile, and if that failed, would
5935 issue a superfluous error message and then attempt to attach it as
5936 a process. Now, if the second argument begins with a non-digit,
5937 it will be treated as a corefile. If it begins with a digit,
5938 GDB will attempt to attach it as a process, and if no such process
5939 is found, will then attempt to open it as a corefile.
5941 * Changes in ARM configurations.
5943 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5944 configuration is fully multi-arch.
5946 * New native configurations
5948 ARM NetBSD arm*-*-netbsd*
5949 x86 OpenBSD i[3456]86-*-openbsd*
5950 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5951 Sparc64 running FreeBSD sparc64-*-freebsd*
5955 Sanyo XStormy16 xstormy16-elf
5957 * OBSOLETE configurations and files
5959 Configurations that have been declared obsolete in this release have
5960 been commented out. Unless there is activity to revive these
5961 configurations, the next release of GDB will have their sources
5962 permanently REMOVED.
5964 AMD 29k family via UDI a29k-amd-udi, udi29k
5965 A29K VxWorks a29k-*-vxworks
5966 AMD 29000 embedded, using EBMON a29k-none-none
5967 AMD 29000 embedded with COFF a29k-none-coff
5968 AMD 29000 embedded with a.out a29k-none-aout
5970 testsuite/gdb.hp/gdb.threads-hp/ directory
5972 * REMOVED configurations and files
5974 TI TMS320C80 tic80-*-*
5976 PowerPC Solaris powerpcle-*-solaris*
5977 PowerPC Windows NT powerpcle-*-cygwin32
5978 PowerPC Netware powerpc-*-netware*
5979 Harris/CXUX m88k m88*-harris-cxux*
5980 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5981 ns32k-utek-sysv* ns32k-utek-*
5982 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5983 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5984 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5985 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5986 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5988 * Changes to command line processing
5990 The new `--args' feature can be used to specify command-line arguments
5991 for the inferior from gdb's command line.
5993 * Changes to key bindings
5995 There is a new `operate-and-get-next' function bound to `C-o'.
5997 *** Changes in GDB 5.1.1
5999 Fix compile problem on DJGPP.
6001 Fix a problem with floating-point registers on the i386 being
6004 Fix to stop GDB crashing on .debug_str debug info.
6006 Numerous documentation fixes.
6008 Numerous testsuite fixes.
6010 *** Changes in GDB 5.1:
6012 * New native configurations
6014 Alpha FreeBSD alpha*-*-freebsd*
6015 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6016 MIPS GNU/Linux mips*-*-linux*
6017 MIPS SGI Irix 6.x mips*-sgi-irix6*
6018 ia64 AIX ia64-*-aix*
6019 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6023 Motorola 68HC11 and 68HC12 m68hc11-elf
6025 UltraSparc running GNU/Linux sparc64-*-linux*
6027 * OBSOLETE configurations and files
6029 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6030 Harris/CXUX m88k m88*-harris-cxux*
6031 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6032 ns32k-utek-sysv* ns32k-utek-*
6033 TI TMS320C80 tic80-*-*
6035 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6036 PowerPC Solaris powerpcle-*-solaris*
6037 PowerPC Windows NT powerpcle-*-cygwin32
6038 PowerPC Netware powerpc-*-netware*
6039 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6040 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6041 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6042 Apple Macintosh (MPW) host N/A
6044 stuff.c (Program to stuff files into a specially prepared space in kdb)
6045 kdb-start.c (Main loop for the standalone kernel debugger)
6047 Configurations that have been declared obsolete in this release have
6048 been commented out. Unless there is activity to revive these
6049 configurations, the next release of GDB will have their sources
6050 permanently REMOVED.
6052 * REMOVED configurations and files
6054 Altos 3068 m68*-altos-*
6055 Convex c1-*-*, c2-*-*
6057 ARM RISCix arm-*-* (as host)
6061 * GDB has been converted to ISO C.
6063 GDB's source code has been converted to ISO C. In particular, the
6064 sources are fully protoized, and rely on standard headers being
6069 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6071 * The MI enabled by default.
6073 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6074 revised and enabled by default. Packages which use GDB as a debugging
6075 engine behind a UI or another front end are encouraged to switch to
6076 using the GDB/MI interface, instead of the old annotations interface
6077 which is now deprecated.
6079 * Support for debugging Pascal programs.
6081 GDB now includes support for debugging Pascal programs. The following
6082 main features are supported:
6084 - Pascal-specific data types such as sets;
6086 - automatic recognition of Pascal sources based on file-name
6089 - Pascal-style display of data types, variables, and functions;
6091 - a Pascal expression parser.
6093 However, some important features are not yet supported.
6095 - Pascal string operations are not supported at all;
6097 - there are some problems with boolean types;
6099 - Pascal type hexadecimal constants are not supported
6100 because they conflict with the internal variables format;
6102 - support for Pascal objects and classes is not full yet;
6104 - unlike Pascal, GDB is case-sensitive for symbol names.
6106 * Changes in completion.
6108 Commands such as `shell', `run' and `set args', which pass arguments
6109 to inferior programs, now complete on file names, similar to what
6110 users expect at the shell prompt.
6112 Commands which accept locations, such as `disassemble', `print',
6113 `breakpoint', `until', etc. now complete on filenames as well as
6114 program symbols. Thus, if you type "break foob TAB", and the source
6115 files linked into the programs include `foobar.c', that file name will
6116 be one of the candidates for completion. However, file names are not
6117 considered for completion after you typed a colon that delimits a file
6118 name from a name of a function in that file, as in "break foo.c:bar".
6120 `set demangle-style' completes on available demangling styles.
6122 * New platform-independent commands:
6124 It is now possible to define a post-hook for a command as well as a
6125 hook that runs before the command. For more details, see the
6126 documentation of `hookpost' in the GDB manual.
6128 * Changes in GNU/Linux native debugging.
6130 Support for debugging multi-threaded programs has been completely
6131 revised for all platforms except m68k and sparc. You can now debug as
6132 many threads as your system allows you to have.
6134 Attach/detach is supported for multi-threaded programs.
6136 Support for SSE registers was added for x86. This doesn't work for
6137 multi-threaded programs though.
6139 * Changes in MIPS configurations.
6141 Multi-arch support is enabled for all MIPS configurations.
6143 GDB can now be built as native debugger on SGI Irix 6.x systems for
6144 debugging n32 executables. (Debugging 64-bit executables is not yet
6147 * Unified support for hardware watchpoints in all x86 configurations.
6149 Most (if not all) native x86 configurations support hardware-assisted
6150 breakpoints and watchpoints in a unified manner. This support
6151 implements debug register sharing between watchpoints, which allows to
6152 put a virtually infinite number of watchpoints on the same address,
6153 and also supports watching regions up to 16 bytes with several debug
6156 The new maintenance command `maintenance show-debug-regs' toggles
6157 debugging print-outs in functions that insert, remove, and test
6158 watchpoints and hardware breakpoints.
6160 * Changes in the DJGPP native configuration.
6162 New command ``info dos sysinfo'' displays assorted information about
6163 the CPU, OS, memory, and DPMI server.
6165 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6166 display information about segment descriptors stored in GDT, LDT, and
6169 New commands ``info dos pde'' and ``info dos pte'' display entries
6170 from Page Directory and Page Tables (for now works with CWSDPMI only).
6171 New command ``info dos address-pte'' displays the Page Table entry for
6172 a given linear address.
6174 GDB can now pass command lines longer than 126 characters to the
6175 program being debugged (requires an update to the libdbg.a library
6176 which is part of the DJGPP development kit).
6178 DWARF2 debug info is now supported.
6180 It is now possible to `step' and `next' through calls to `longjmp'.
6182 * Changes in documentation.
6184 All GDB documentation was converted to GFDL, the GNU Free
6185 Documentation License.
6187 Tracepoints-related commands are now fully documented in the GDB
6190 TUI, the Text-mode User Interface, is now documented in the manual.
6192 Tracepoints-related commands are now fully documented in the GDB
6195 The "GDB Internals" manual now has an index. It also includes
6196 documentation of `ui_out' functions, GDB coding standards, x86
6197 hardware watchpoints, and memory region attributes.
6199 * GDB's version number moved to ``version.in''
6201 The Makefile variable VERSION has been replaced by the file
6202 ``version.in''. People creating GDB distributions should update the
6203 contents of this file.
6207 GUD support is now a standard part of the EMACS distribution.
6209 *** Changes in GDB 5.0:
6211 * Improved support for debugging FP programs on x86 targets
6213 Unified and much-improved support for debugging floating-point
6214 programs on all x86 targets. In particular, ``info float'' now
6215 displays the FP registers in the same format on all x86 targets, with
6216 greater level of detail.
6218 * Improvements and bugfixes in hardware-assisted watchpoints
6220 It is now possible to watch array elements, struct members, and
6221 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6222 on x86 targets no longer erroneously trigger when the address is
6225 * Improvements in the native DJGPP version of GDB
6227 The distribution now includes all the scripts and auxiliary files
6228 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6229 machines ``out of the box''.
6231 The DJGPP version can now debug programs that use signals. It is
6232 possible to catch signals that happened in the debuggee, deliver
6233 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6234 would kill the program being debugged.) Programs that hook hardware
6235 interrupts (keyboard, timer, etc.) can also be debugged.
6237 It is now possible to debug DJGPP programs that redirect their
6238 standard handles or switch them to raw (as opposed to cooked) mode, or
6239 even close them. The command ``run < foo > bar'' works as expected,
6240 and ``info terminal'' reports useful information about the debuggee's
6241 terminal, including raw/cooked mode, redirection, etc.
6243 The DJGPP version now uses termios functions for console I/O, which
6244 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6247 DOS-style file names with drive letters are now fully supported by
6250 It is now possible to debug DJGPP programs that switch their working
6251 directory. It is also possible to rerun the debuggee any number of
6252 times without restarting GDB; thus, you can use the same setup,
6253 breakpoints, etc. for many debugging sessions.
6255 * New native configurations
6257 ARM GNU/Linux arm*-*-linux*
6258 PowerPC GNU/Linux powerpc-*-linux*
6262 Motorola MCore mcore-*-*
6263 x86 VxWorks i[3456]86-*-vxworks*
6264 PowerPC VxWorks powerpc-*-vxworks*
6265 TI TMS320C80 tic80-*-*
6267 * OBSOLETE configurations
6269 Altos 3068 m68*-altos-*
6270 Convex c1-*-*, c2-*-*
6272 ARM RISCix arm-*-* (as host)
6275 Configurations that have been declared obsolete will be commented out,
6276 but the code will be left in place. If there is no activity to revive
6277 these configurations before the next release of GDB, the sources will
6278 be permanently REMOVED.
6280 * Gould support removed
6282 Support for the Gould PowerNode and NP1 has been removed.
6284 * New features for SVR4
6286 On SVR4 native platforms (such as Solaris), if you attach to a process
6287 without first loading a symbol file, GDB will now attempt to locate and
6288 load symbols from the running process's executable file.
6290 * Many C++ enhancements
6292 C++ support has been greatly improved. Overload resolution now works properly
6293 in almost all cases. RTTI support is on the way.
6295 * Remote targets can connect to a sub-program
6297 A popen(3) style serial-device has been added. This device starts a
6298 sub-process (such as a stand-alone simulator) and then communicates
6299 with that. The sub-program to run is specified using the syntax
6300 ``|<program> <args>'' vis:
6302 (gdb) set remotedebug 1
6303 (gdb) target extended-remote |mn10300-elf-sim program-args
6305 * MIPS 64 remote protocol
6307 A long standing bug in the mips64 remote protocol where by GDB
6308 expected certain 32 bit registers (ex SR) to be transfered as 32
6309 instead of 64 bits has been fixed.
6311 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6312 added to provide backward compatibility with older versions of GDB.
6314 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6316 The command ``set remotebinarydownload'' command has been replaced by
6317 ``set remote X-packet''. Other commands in ``set remote'' family
6318 include ``set remote P-packet''.
6320 * Breakpoint commands accept ranges.
6322 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6323 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6324 ``tracepoint passcount'' also accepts a range of tracepoints.
6326 * ``apropos'' command added.
6328 The ``apropos'' command searches through command names and
6329 documentation strings, printing out matches, making it much easier to
6330 try to find a command that does what you are looking for.
6334 A new machine oriented interface (MI) has been added to GDB. This
6335 interface is designed for debug environments running GDB as a separate
6336 process. This is part of the long term libGDB project. See the
6337 "GDB/MI" chapter of the GDB manual for further information. It can be
6338 enabled by configuring with:
6340 .../configure --enable-gdbmi
6342 *** Changes in GDB-4.18:
6344 * New native configurations
6346 HP-UX 10.20 hppa*-*-hpux10.20
6347 HP-UX 11.x hppa*-*-hpux11.0*
6348 M68K GNU/Linux m68*-*-linux*
6352 Fujitsu FR30 fr30-*-elf*
6353 Intel StrongARM strongarm-*-*
6354 Mitsubishi D30V d30v-*-*
6356 * OBSOLETE configurations
6358 Gould PowerNode, NP1 np1-*-*, pn-*-*
6360 Configurations that have been declared obsolete will be commented out,
6361 but the code will be left in place. If there is no activity to revive
6362 these configurations before the next release of GDB, the sources will
6363 be permanently REMOVED.
6367 As a compatibility experiment, GDB's source files buildsym.h and
6368 buildsym.c have been converted to pure standard C, no longer
6369 containing any K&R compatibility code. We believe that all systems in
6370 use today either come with a standard C compiler, or have a GCC port
6371 available. If this is not true, please report the affected
6372 configuration to bug-gdb@gnu.org immediately. See the README file for
6373 information about getting a standard C compiler if you don't have one
6378 GDB now uses readline 2.2.
6380 * set extension-language
6382 You can now control the mapping between filename extensions and source
6383 languages by using the `set extension-language' command. For instance,
6384 you can ask GDB to treat .c files as C++ by saying
6385 set extension-language .c c++
6386 The command `info extensions' lists all of the recognized extensions
6387 and their associated languages.
6389 * Setting processor type for PowerPC and RS/6000
6391 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6392 you can use the `set processor' command to specify what variant of the
6393 PowerPC family you are debugging. The command
6397 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6398 following PowerPC and RS6000 variants:
6400 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6401 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6403 403GC IBM PowerPC 403GC
6404 505 Motorola PowerPC 505
6405 860 Motorola PowerPC 860 or 850
6406 601 Motorola PowerPC 601
6407 602 Motorola PowerPC 602
6408 603 Motorola/IBM PowerPC 603 or 603e
6409 604 Motorola PowerPC 604 or 604e
6410 750 Motorola/IBM PowerPC 750 or 750
6412 At the moment, this command just tells GDB what to name the
6413 special-purpose processor registers. Since almost all the affected
6414 registers are inaccessible to user-level programs, this command is
6415 only useful for remote debugging in its present form.
6419 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6420 more extensive support for HP-UX. Added features include shared
6421 library support, kernel threads and hardware watchpoints for 11.00,
6422 support for HP's ANSI C and C++ compilers, and a compatibility mode
6423 for xdb and dbx commands.
6427 HP's donation includes the new concept of catchpoints, which is a
6428 generalization of the old catch command. On HP-UX, it is now possible
6429 to catch exec, fork, and vfork, as well as library loading.
6431 This means that the existing catch command has changed; its first
6432 argument now specifies the type of catch to be set up. See the
6433 output of "help catch" for a list of catchpoint types.
6435 * Debugging across forks
6437 On HP-UX, you can choose which process to debug when a fork() happens
6442 HP has donated a curses-based terminal user interface (TUI). To get
6443 it, build with --enable-tui. Although this can be enabled for any
6444 configuration, at present it only works for native HP debugging.
6446 * GDB remote protocol additions
6448 A new protocol packet 'X' that writes binary data is now available.
6449 Default behavior is to try 'X', then drop back to 'M' if the stub
6450 fails to respond. The settable variable `remotebinarydownload'
6451 allows explicit control over the use of 'X'.
6453 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6454 full 64-bit address. The command
6456 set remoteaddresssize 32
6458 can be used to revert to the old behaviour. For existing remote stubs
6459 the change should not be noticed, as the additional address information
6462 In order to assist in debugging stubs, you may use the maintenance
6463 command `packet' to send any text string to the stub. For instance,
6465 maint packet heythere
6467 sends the packet "$heythere#<checksum>". Note that it is very easy to
6468 disrupt a debugging session by sending the wrong packet at the wrong
6471 The compare-sections command allows you to compare section data on the
6472 target to what is in the executable file without uploading or
6473 downloading, by comparing CRC checksums.
6475 * Tracing can collect general expressions
6477 You may now collect general expressions at tracepoints. This requires
6478 further additions to the target-side stub; see tracepoint.c and
6479 doc/agentexpr.texi for further details.
6481 * mask-address variable for Mips
6483 For Mips targets, you may control the zeroing of the upper 32 bits of
6484 a 64-bit address by entering `set mask-address on'. This is mainly
6485 of interest to users of embedded R4xxx and R5xxx processors.
6487 * Higher serial baud rates
6489 GDB's serial code now allows you to specify baud rates 57600, 115200,
6490 230400, and 460800 baud. (Note that your host system may not be able
6491 to achieve all of these rates.)
6495 The i960 configuration now includes an initial implementation of a
6496 builtin simulator, contributed by Jim Wilson.
6499 *** Changes in GDB-4.17:
6501 * New native configurations
6503 Alpha GNU/Linux alpha*-*-linux*
6504 Unixware 2.x i[3456]86-unixware2*
6505 Irix 6.x mips*-sgi-irix6*
6506 PowerPC GNU/Linux powerpc-*-linux*
6507 PowerPC Solaris powerpcle-*-solaris*
6508 Sparc GNU/Linux sparc-*-linux*
6509 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6513 Argonaut Risc Chip (ARC) arc-*-*
6514 Hitachi H8/300S h8300*-*-*
6515 Matsushita MN10200 w/simulator mn10200-*-*
6516 Matsushita MN10300 w/simulator mn10300-*-*
6517 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6518 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6519 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6520 Mitsubishi D10V w/simulator d10v-*-*
6521 Mitsubishi M32R/D w/simulator m32r-*-elf*
6522 Tsqware Sparclet sparclet-*-*
6523 NEC V850 w/simulator v850-*-*
6525 * New debugging protocols
6527 ARM with RDI protocol arm*-*-*
6528 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6529 DDB and LSI variants of PMON protocol mips*-*-*
6530 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6531 PowerPC with SDS protocol powerpc{,le}-*-eabi
6532 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6536 All configurations can now understand and use the DWARF 2 debugging
6537 format. The choice is automatic, if the symbol file contains DWARF 2
6542 GDB now includes basic Java language support. This support is
6543 only useful with Java compilers that produce native machine code.
6545 * solib-absolute-prefix and solib-search-path
6547 For SunOS and SVR4 shared libraries, you may now set the prefix for
6548 loading absolute shared library symbol files, and the search path for
6549 locating non-absolute shared library symbol files.
6551 * Live range splitting
6553 GDB can now effectively debug code for which GCC has performed live
6554 range splitting as part of its optimization. See gdb/doc/LRS for
6555 more details on the expected format of the stabs information.
6559 GDB's support for the GNU Hurd, including thread debugging, has been
6560 updated to work with current versions of the Hurd.
6564 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6565 instruction set. ARM GDB automatically detects when Thumb
6566 instructions are in use, and adjusts disassembly and backtracing
6571 GDB's MIPS target configurations now handle the MIP16 16-bit
6576 GDB now includes support for overlays; if an executable has been
6577 linked such that multiple sections are based at the same address, GDB
6578 will decide which section to use for symbolic info. You can choose to
6579 control the decision manually, using overlay commands, or implement
6580 additional target-side support and use "overlay load-target" to bring
6581 in the overlay mapping. Do "help overlay" for more detail.
6585 The command "info symbol <address>" displays information about
6586 the symbol at the specified address.
6590 The standard remote protocol now includes an extension that allows
6591 asynchronous collection and display of trace data. This requires
6592 extensive support in the target-side debugging stub. Tracing mode
6593 includes a new interaction mode in GDB and new commands: see the
6594 file tracepoint.c for more details.
6598 Configurations for embedded MIPS now include a simulator contributed
6599 by Cygnus Solutions. The simulator supports the instruction sets
6600 of most MIPS variants.
6604 Sparc configurations may now include the ERC32 simulator contributed
6605 by the European Space Agency. The simulator is not built into
6606 Sparc targets by default; configure with --enable-sim to include it.
6610 For target configurations that may include multiple variants of a
6611 basic architecture (such as MIPS and SH), you may now set the
6612 architecture explicitly. "set arch" sets, "info arch" lists
6613 the possible architectures.
6615 *** Changes in GDB-4.16:
6617 * New native configurations
6619 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6620 M68K NetBSD m68k-*-netbsd*
6621 PowerPC AIX 4.x powerpc-*-aix*
6622 PowerPC MacOS powerpc-*-macos*
6623 PowerPC Windows NT powerpcle-*-cygwin32
6624 RS/6000 AIX 4.x rs6000-*-aix4*
6628 ARM with RDP protocol arm-*-*
6629 I960 with MON960 i960-*-coff
6630 MIPS VxWorks mips*-*-vxworks*
6631 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6632 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6634 Matra Sparclet sparclet-*-*
6638 The powerpc-eabi configuration now includes the PSIM simulator,
6639 contributed by Andrew Cagney, with assistance from Mike Meissner.
6640 PSIM is a very elaborate model of the PowerPC, including not only
6641 basic instruction set execution, but also details of execution unit
6642 performance and I/O hardware. See sim/ppc/README for more details.
6646 GDB now works with Solaris 2.5.
6648 * Windows 95/NT native
6650 GDB will now work as a native debugger on Windows 95 and Windows NT.
6651 To build it from source, you must use the "gnu-win32" environment,
6652 which uses a DLL to emulate enough of Unix to run the GNU tools.
6653 Further information, binaries, and sources are available at
6654 ftp.cygnus.com, under pub/gnu-win32.
6656 * dont-repeat command
6658 If a user-defined command includes the command `dont-repeat', then the
6659 command will not be repeated if the user just types return. This is
6660 useful if the command is time-consuming to run, so that accidental
6661 extra keystrokes don't run the same command many times.
6663 * Send break instead of ^C
6665 The standard remote protocol now includes an option to send a break
6666 rather than a ^C to the target in order to interrupt it. By default,
6667 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6669 * Remote protocol timeout
6671 The standard remote protocol includes a new variable `remotetimeout'
6672 that allows you to set the number of seconds before GDB gives up trying
6673 to read from the target. The default value is 2.
6675 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6677 By default GDB will automatically keep track of objects as they are
6678 loaded and unloaded by the dynamic linker. By using the command `set
6679 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6680 when shared library events occur, thus allowing you to set breakpoints
6681 in shared libraries which are explicitly loaded by the inferior.
6683 Note this feature does not work on hpux8. On hpux9 you must link
6684 /usr/lib/end.o into your program. This feature should work
6685 automatically on hpux10.
6687 * Irix 5.x hardware watchpoint support
6689 Irix 5 configurations now support the use of hardware watchpoints.
6691 * Mips protocol "SYN garbage limit"
6693 When debugging a Mips target using the `target mips' protocol, you
6694 may set the number of characters that GDB will ignore by setting
6695 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6696 every character. The default value is 1050.
6698 * Recording and replaying remote debug sessions
6700 If you set `remotelogfile' to the name of a file, gdb will write to it
6701 a recording of a remote debug session. This recording may then be
6702 replayed back to gdb using "gdbreplay". See gdbserver/README for
6703 details. This is useful when you have a problem with GDB while doing
6704 remote debugging; you can make a recording of the session and send it
6705 to someone else, who can then recreate the problem.
6707 * Speedups for remote debugging
6709 GDB includes speedups for downloading and stepping MIPS systems using
6710 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6711 and more efficient S-record downloading.
6713 * Memory use reductions and statistics collection
6715 GDB now uses less memory and reports statistics about memory usage.
6716 Try the `maint print statistics' command, for example.
6718 *** Changes in GDB-4.15:
6720 * Psymtabs for XCOFF
6722 The symbol reader for AIX GDB now uses partial symbol tables. This
6723 can greatly improve startup time, especially for large executables.
6725 * Remote targets use caching
6727 Remote targets now use a data cache to speed up communication with the
6728 remote side. The data cache could lead to incorrect results because
6729 it doesn't know about volatile variables, thus making it impossible to
6730 debug targets which use memory mapped I/O devices. `set remotecache
6731 off' turns the data cache off.
6733 * Remote targets may have threads
6735 The standard remote protocol now includes support for multiple threads
6736 in the target system, using new protocol commands 'H' and 'T'. See
6737 gdb/remote.c for details.
6741 If GDB is configured with `--enable-netrom', then it will include
6742 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6743 acts as though it is a bank of ROM on the target board, but you can
6744 write into it over the network. GDB's support consists only of
6745 support for fast loading into the emulated ROM; to debug, you must use
6746 another protocol, such as standard remote protocol. The usual
6747 sequence is something like
6749 target nrom <netrom-hostname>
6751 target remote <netrom-hostname>:1235
6755 GDB now includes support for the Apple Macintosh, as a host only. It
6756 may be run as either an MPW tool or as a standalone application, and
6757 it can debug through the serial port. All the usual GDB commands are
6758 available, but to the target command, you must supply "serial" as the
6759 device type instead of "/dev/ttyXX". See mpw-README in the main
6760 directory for more information on how to build. The MPW configuration
6761 scripts */mpw-config.in support only a few targets, and only the
6762 mips-idt-ecoff target has been tested.
6766 GDB configuration now uses autoconf. This is not user-visible,
6767 but does simplify configuration and building.
6771 GDB now supports hpux10.
6773 *** Changes in GDB-4.14:
6775 * New native configurations
6777 x86 FreeBSD i[345]86-*-freebsd
6778 x86 NetBSD i[345]86-*-netbsd
6779 NS32k NetBSD ns32k-*-netbsd
6780 Sparc NetBSD sparc-*-netbsd
6784 A29K VxWorks a29k-*-vxworks
6785 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6786 CPU32 EST-300 emulator m68*-*-est*
6787 PowerPC ELF powerpc-*-elf
6790 * Alpha OSF/1 support for procfs
6792 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6793 possible to attach to running processes. As the mounting of the /proc
6794 filesystem is optional on the Alpha, GDB automatically determines
6795 the availability of /proc during startup. This can lead to problems
6796 if /proc is unmounted after GDB has been started.
6798 * Arguments to user-defined commands
6800 User commands may accept up to 10 arguments separated by whitespace.
6801 Arguments are accessed within the user command via $arg0..$arg9. A
6804 print $arg0 + $arg1 + $arg2
6806 To execute the command use:
6809 Defines the command "adder" which prints the sum of its three arguments.
6810 Note the arguments are text substitutions, so they may reference variables,
6811 use complex expressions, or even perform inferior function calls.
6813 * New `if' and `while' commands
6815 This makes it possible to write more sophisticated user-defined
6816 commands. Both commands take a single argument, which is the
6817 expression to evaluate, and must be followed by the commands to
6818 execute, one per line, if the expression is nonzero, the list being
6819 terminated by the word `end'. The `if' command list may include an
6820 `else' word, which causes the following commands to be executed only
6821 if the expression is zero.
6823 * Fortran source language mode
6825 GDB now includes partial support for Fortran 77. It will recognize
6826 Fortran programs and can evaluate a subset of Fortran expressions, but
6827 variables and functions may not be handled correctly. GDB will work
6828 with G77, but does not yet know much about symbols emitted by other
6831 * Better HPUX support
6833 Most debugging facilities now work on dynamic executables for HPPAs
6834 running hpux9 or later. You can attach to running dynamically linked
6835 processes, but by default the dynamic libraries will be read-only, so
6836 for instance you won't be able to put breakpoints in them. To change
6837 that behavior do the following before running the program:
6843 This will cause the libraries to be mapped private and read-write.
6844 To revert to the normal behavior, do this:
6850 You cannot set breakpoints or examine data in the library until after
6851 the library is loaded if the function/data symbols do not have
6854 GDB can now also read debug symbols produced by the HP C compiler on
6855 HPPAs (sorry, no C++, Fortran or 68k support).
6857 * Target byte order now dynamically selectable
6859 You can choose which byte order to use with a target system, via the
6860 commands "set endian big" and "set endian little", and you can see the
6861 current setting by using "show endian". You can also give the command
6862 "set endian auto", in which case GDB will use the byte order
6863 associated with the executable. Currently, only embedded MIPS
6864 configurations support dynamic selection of target byte order.
6866 * New DOS host serial code
6868 This version uses DPMI interrupts to handle buffered I/O, so you
6869 no longer need to run asynctsr when debugging boards connected to
6872 *** Changes in GDB-4.13:
6874 * New "complete" command
6876 This lists all the possible completions for the rest of the line, if it
6877 were to be given as a command itself. This is intended for use by emacs.
6879 * Trailing space optional in prompt
6881 "set prompt" no longer adds a space for you after the prompt you set. This
6882 allows you to set a prompt which ends in a space or one that does not.
6884 * Breakpoint hit counts
6886 "info break" now displays a count of the number of times the breakpoint
6887 has been hit. This is especially useful in conjunction with "ignore"; you
6888 can ignore a large number of breakpoint hits, look at the breakpoint info
6889 to see how many times the breakpoint was hit, then run again, ignoring one
6890 less than that number, and this will get you quickly to the last hit of
6893 * Ability to stop printing at NULL character
6895 "set print null-stop" will cause GDB to stop printing the characters of
6896 an array when the first NULL is encountered. This is useful when large
6897 arrays actually contain only short strings.
6899 * Shared library breakpoints
6901 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6902 breakpoints in shared libraries before the executable is run.
6904 * Hardware watchpoints
6906 There is a new hardware breakpoint for the watch command for sparclite
6907 targets. See gdb/sparclite/hw_breakpoint.note.
6909 Hardware watchpoints are also now supported under GNU/Linux.
6913 Annotations have been added. These are for use with graphical interfaces,
6914 and are still experimental. Currently only gdba.el uses these.
6916 * Improved Irix 5 support
6918 GDB now works properly with Irix 5.2.
6920 * Improved HPPA support
6922 GDB now works properly with the latest GCC and GAS.
6924 * New native configurations
6926 Sequent PTX4 i[34]86-sequent-ptx4
6927 HPPA running OSF/1 hppa*-*-osf*
6928 Atari TT running SVR4 m68*-*-sysv4*
6929 RS/6000 LynxOS rs6000-*-lynxos*
6933 OS/9000 i[34]86-*-os9k
6934 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6937 * Hitachi SH7000 and E7000-PC ICE support
6939 There is now support for communicating with the Hitachi E7000-PC ICE.
6940 This is available automatically when GDB is configured for the SH.
6944 As usual, a variety of small fixes and improvements, both generic
6945 and configuration-specific. See the ChangeLog for more detail.
6947 *** Changes in GDB-4.12:
6949 * Irix 5 is now supported
6953 GDB-4.12 on the HPPA has a number of changes which make it unable
6954 to debug the output from the currently released versions of GCC and
6955 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6956 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6957 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6960 *** Changes in GDB-4.11:
6962 * User visible changes:
6966 The "set remotedebug" option is now consistent between the mips remote
6967 target, remote targets using the gdb-specific protocol, UDI (AMD's
6968 debug protocol for the 29k) and the 88k bug monitor. It is now an
6969 integer specifying a debug level (normally 0 or 1, but 2 means more
6970 debugging info for the mips target).
6972 * DEC Alpha native support
6974 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6975 debug info, but GDB works fairly well with the DEC compiler and should
6976 work with a future GCC release. See the README file for a few
6977 Alpha-specific notes.
6979 * Preliminary thread implementation
6981 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6983 * LynxOS native and target support for 386
6985 This release has been hosted on LynxOS 2.2, and also can be configured
6986 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6989 * Improvements in C++ mangling/demangling.
6991 This release has much better g++ debugging, specifically in name
6992 mangling/demangling, virtual function calls, print virtual table,
6993 call methods, ...etc.
6995 *** Changes in GDB-4.10:
6997 * User visible changes:
6999 Remote debugging using the GDB-specific (`target remote') protocol now
7000 supports the `load' command. This is only useful if you have some
7001 other way of getting the stub to the target system, and you can put it
7002 somewhere in memory where it won't get clobbered by the download.
7004 Filename completion now works.
7006 When run under emacs mode, the "info line" command now causes the
7007 arrow to point to the line specified. Also, "info line" prints
7008 addresses in symbolic form (as well as hex).
7010 All vxworks based targets now support a user settable option, called
7011 vxworks-timeout. This option represents the number of seconds gdb
7012 should wait for responses to rpc's. You might want to use this if
7013 your vxworks target is, perhaps, a slow software simulator or happens
7014 to be on the far side of a thin network line.
7018 This release contains support for using a DEC alpha as a GDB host for
7019 cross debugging. Native alpha debugging is not supported yet.
7022 *** Changes in GDB-4.9:
7026 This is the first GDB release which is accompanied by a matching testsuite.
7027 The testsuite requires installation of dejagnu, which should be available
7028 via ftp from most sites that carry GNU software.
7032 'Cfront' style demangling has had its name changed to 'ARM' style, to
7033 emphasize that it was written from the specifications in the C++ Annotated
7034 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7035 disclaimers, it still generated too much confusion with users attempting to
7036 use gdb with AT&T cfront.
7040 GDB now uses a standard remote interface to a simulator library.
7041 So far, the library contains simulators for the Zilog Z8001/2, the
7042 Hitachi H8/300, H8/500 and Super-H.
7044 * New targets supported
7046 H8/300 simulator h8300-hitachi-hms or h8300hms
7047 H8/500 simulator h8500-hitachi-hms or h8500hms
7048 SH simulator sh-hitachi-hms or sh
7049 Z8000 simulator z8k-zilog-none or z8ksim
7050 IDT MIPS board over serial line mips-idt-ecoff
7052 Cross-debugging to GO32 targets is supported. It requires a custom
7053 version of the i386-stub.c module which is integrated with the
7054 GO32 memory extender.
7056 * New remote protocols
7058 MIPS remote debugging protocol.
7060 * New source languages supported
7062 This version includes preliminary support for Chill, a Pascal like language
7063 used by telecommunications companies. Chill support is also being integrated
7064 into the GNU compiler, but we don't know when it will be publically available.
7067 *** Changes in GDB-4.8:
7069 * HP Precision Architecture supported
7071 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7072 version of this support was available as a set of patches from the
7073 University of Utah. GDB does not support debugging of programs
7074 compiled with the HP compiler, because HP will not document their file
7075 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7076 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7078 Many problems in the preliminary version have been fixed.
7080 * Faster and better demangling
7082 We have improved template demangling and fixed numerous bugs in the GNU style
7083 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7084 character types (wchar_t) are now supported. Demangling of each symbol is now
7085 only done once, and is cached when the symbol table for a file is read in.
7086 This results in a small increase in memory usage for C programs, a moderate
7087 increase in memory usage for C++ programs, and a fantastic speedup in
7090 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7091 from the specifications in the Annotated Reference Manual, which AT&T's
7092 compiler does not actually implement.
7094 * G++ multiple inheritance compiler problem
7096 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7097 inheritance lattices was reworked to properly discover ambiguities. We
7098 recently found an example which causes this new algorithm to fail in a
7099 very subtle way, producing bad debug information for those classes.
7100 The file 'gcc.patch' (in this directory) can be applied to gcc to
7101 circumvent the problem. A future GCC release will contain a complete
7104 The previous G++ debug info problem (mentioned below for the gdb-4.7
7105 release) is fixed in gcc version 2.3.2.
7107 * Improved configure script
7109 The `configure' script will now attempt to guess your system type if
7110 you don't supply a host system type. The old scheme of supplying a
7111 host system triplet is preferable over using this. All the magic is
7112 done in the new `config.guess' script. Examine it for details.
7114 We have also brought our configure script much more in line with the FSF's
7115 version. It now supports the --with-xxx options. In particular,
7116 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7117 The resulting GDB will not be able to read arbitrary object file formats --
7118 only the format ``expected'' to be used on the configured target system.
7119 We hope to make this the default in a future release.
7121 * Documentation improvements
7123 There's new internal documentation on how to modify GDB, and how to
7124 produce clean changes to the code. We implore people to read it
7125 before submitting changes.
7127 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7128 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7129 `info' files are also provided. To build `info' files from scratch,
7130 you will need the latest `makeinfo' release, which will be available in
7131 a future texinfo-X.Y release.
7133 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7134 We're not sure exactly which versions have this problem, but it has
7135 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7136 or better. If that isn't possible, there is a patch in
7137 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7138 around this problem.
7142 GDB now supports array constants that can be used in expressions typed in by
7143 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7144 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7147 The new directory `gdb/sparclite' contains a program that demonstrates
7148 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7150 * New native hosts supported
7152 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7153 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7155 * New targets supported
7157 AMD 29k family via UDI a29k-amd-udi or udi29k
7159 * New file formats supported
7161 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7162 HPUX core files, and SCO 3.2v2 core files.
7166 Attaching to processes now works again; thanks for the many bug reports.
7168 We have also stomped on a bunch of core dumps caused by
7169 printf_filtered("%s") problems.
7171 We eliminated a copyright problem on the rpc and ptrace header files
7172 for VxWorks, which was discovered at the last minute during the 4.7
7173 release. You should now be able to build a VxWorks GDB.
7175 You can now interrupt gdb while an attached process is running. This
7176 will cause the attached process to stop, and give control back to GDB.
7178 We fixed problems caused by using too many file descriptors
7179 for reading symbols from object files and libraries. This was
7180 especially a problem for programs that used many (~100) shared
7183 The `step' command now only enters a subroutine if there is line number
7184 information for the subroutine. Otherwise it acts like the `next'
7185 command. Previously, `step' would enter subroutines if there was
7186 any debugging information about the routine. This avoids problems
7187 when using `cc -g1' on MIPS machines.
7189 * Internal improvements
7191 GDB's internal interfaces have been improved to make it easier to support
7192 debugging of multiple languages in the future.
7194 GDB now uses a common structure for symbol information internally.
7195 Minimal symbols (derived from linkage symbols in object files), partial
7196 symbols (from a quick scan of debug information), and full symbols
7197 contain a common subset of information, making it easier to write
7198 shared code that handles any of them.
7200 * New command line options
7202 We now accept --silent as an alias for --quiet.
7206 The memory-mapped-malloc library is now licensed under the GNU Library
7207 General Public License.
7209 *** Changes in GDB-4.7:
7211 * Host/native/target split
7213 GDB has had some major internal surgery to untangle the support for
7214 hosts and remote targets. Now, when you configure GDB for a remote
7215 target, it will no longer load in all of the support for debugging
7216 local programs on the host. When fully completed and tested, this will
7217 ensure that arbitrary host/target combinations are possible.
7219 The primary conceptual shift is to separate the non-portable code in
7220 GDB into three categories. Host specific code is required any time GDB
7221 is compiled on that host, regardless of the target. Target specific
7222 code relates to the peculiarities of the target, but can be compiled on
7223 any host. Native specific code is everything else: it can only be
7224 built when the host and target are the same system. Child process
7225 handling and core file support are two common `native' examples.
7227 GDB's use of /proc for controlling Unix child processes is now cleaner.
7228 It has been split out into a single module under the `target_ops' vector,
7229 plus two native-dependent functions for each system that uses /proc.
7231 * New hosts supported
7233 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7234 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7235 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7237 * New targets supported
7239 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7240 68030 and CPU32 m68030-*-*, m68332-*-*
7242 * New native hosts supported
7244 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7245 (386bsd is not well tested yet)
7246 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7248 * New file formats supported
7250 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7251 supports reading of `a.out.adobe' object files, which are an a.out
7252 format extended with minimal information about multiple sections.
7256 `show copying' is the same as the old `info copying'.
7257 `show warranty' is the same as `info warrantee'.
7258 These were renamed for consistency. The old commands continue to work.
7260 `info handle' is a new alias for `info signals'.
7262 You can now define pre-command hooks, which attach arbitrary command
7263 scripts to any command. The commands in the hook will be executed
7264 prior to the user's command. You can also create a hook which will be
7265 executed whenever the program stops. See gdb.texinfo.
7269 We now deal with Cfront style name mangling, and can even extract type
7270 info from mangled symbols. GDB can automatically figure out which
7271 symbol mangling style your C++ compiler uses.
7273 Calling of methods and virtual functions has been improved as well.
7277 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7278 fixed. This was due to mishandling of the extra N_SO stabs output
7281 We also finally got Ultrix 4.2 running in house, and fixed core file
7282 support, with help from a dozen people on the net.
7284 John M. Farrell discovered that the reason that single-stepping was so
7285 slow on all of the Mips based platforms (primarily SGI and DEC) was
7286 that we were trying to demangle and lookup a symbol used for internal
7287 purposes on every instruction that was being stepped through. Changing
7288 the name of that symbol so that it couldn't be mistaken for a C++
7289 mangled symbol sped things up a great deal.
7291 Rich Pixley sped up symbol lookups in general by getting much smarter
7292 about when C++ symbol mangling is necessary. This should make symbol
7293 completion (TAB on the command line) much faster. It's not as fast as
7294 we'd like, but it's significantly faster than gdb-4.6.
7298 A new user controllable variable 'call_scratch_address' can
7299 specify the location of a scratch area to be used when GDB
7300 calls a function in the target. This is necessary because the
7301 usual method of putting the scratch area on the stack does not work
7302 in systems that have separate instruction and data spaces.
7304 We integrated changes to support the 29k UDI (Universal Debugger
7305 Interface), but discovered at the last minute that we didn't have all
7306 of the appropriate copyright paperwork. We are working with AMD to
7307 resolve this, and hope to have it available soon.
7311 We have sped up the remote serial line protocol, especially for targets
7312 with lots of registers. It now supports a new `expedited status' ('T')
7313 message which can be used in place of the existing 'S' status message.
7314 This allows the remote stub to send only the registers that GDB
7315 needs to make a quick decision about single-stepping or conditional
7316 breakpoints, eliminating the need to fetch the entire register set for
7317 each instruction being stepped through.
7319 The GDB remote serial protocol now implements a write-through cache for
7320 registers, only re-reading the registers if the target has run.
7322 There is also a new remote serial stub for SPARC processors. You can
7323 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7324 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7325 processor with a serial port.
7329 Configure.in files have become much easier to read and modify. A new
7330 `table driven' format makes it more obvious what configurations are
7331 supported, and what files each one uses.
7335 There is a new opcodes library which will eventually contain all of the
7336 disassembly routines and opcode tables. At present, it only contains
7337 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7338 disassembler (binutils/objdump) to share these routines.
7340 The libiberty library is now copylefted under the GNU Library General
7341 Public License. This allows more liberal use, and was done so libg++
7342 can use it. This makes no difference to GDB, since the Library License
7343 grants all the rights from the General Public License.
7347 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7348 reference to the stabs symbol info used by the debugger. It is (as far
7349 as we know) the only published document on this fascinating topic. We
7350 encourage you to read it, compare it to the stabs information on your
7351 system, and send improvements on the document in general (to
7352 bug-gdb@prep.ai.mit.edu).
7354 And, of course, many bugs have been fixed.
7357 *** Changes in GDB-4.6:
7359 * Better support for C++ function names
7361 GDB now accepts as input the "demangled form" of C++ overloaded function
7362 names and member function names, and can do command completion on such names
7363 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7364 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7365 Make use of command completion, it is your friend.
7367 GDB also now accepts a variety of C++ mangled symbol formats. They are
7368 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7369 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7370 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7371 for the list of formats.
7373 * G++ symbol mangling problem
7375 Recent versions of gcc have a bug in how they emit debugging information for
7376 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7377 directory) can be applied to gcc to fix the problem. Alternatively, if you
7378 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7379 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7380 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7383 * New 'maintenance' command
7385 All of the commands related to hacking GDB internals have been moved out of
7386 the main command set, and now live behind the 'maintenance' command. This
7387 can also be abbreviated as 'mt'. The following changes were made:
7389 dump-me -> maintenance dump-me
7390 info all-breakpoints -> maintenance info breakpoints
7391 printmsyms -> maintenance print msyms
7392 printobjfiles -> maintenance print objfiles
7393 printpsyms -> maintenance print psymbols
7394 printsyms -> maintenance print symbols
7396 The following commands are new:
7398 maintenance demangle Call internal GDB demangler routine to
7399 demangle a C++ link name and prints the result.
7400 maintenance print type Print a type chain for a given symbol
7402 * Change to .gdbinit file processing
7404 We now read the $HOME/.gdbinit file before processing the argv arguments
7405 (e.g. reading symbol files or core files). This allows global parameters to
7406 be set, which will apply during the symbol reading. The ./.gdbinit is still
7407 read after argv processing.
7409 * New hosts supported
7411 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7413 GNU/Linux support i386-unknown-linux or linux
7415 We are also including code to support the HP/PA running BSD and HPUX. This
7416 is almost guaranteed not to work, as we didn't have time to test or build it
7417 for this release. We are including it so that the more adventurous (or
7418 masochistic) of you can play with it. We also had major problems with the
7419 fact that the compiler that we got from HP doesn't support the -g option.
7422 * New targets supported
7424 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7426 * More smarts about finding #include files
7428 GDB now remembers the compilation directory for all include files, and for
7429 all files from which C is generated (like yacc and lex sources). This
7430 greatly improves GDB's ability to find yacc/lex sources, and include files,
7431 especially if you are debugging your program from a directory different from
7432 the one that contains your sources.
7434 We also fixed a bug which caused difficulty with listing and setting
7435 breakpoints in include files which contain C code. (In the past, you had to
7436 try twice in order to list an include file that you hadn't looked at before.)
7438 * Interesting infernals change
7440 GDB now deals with arbitrary numbers of sections, where the symbols for each
7441 section must be relocated relative to that section's landing place in the
7442 target's address space. This work was needed to support ELF with embedded
7443 stabs used by Solaris-2.0.
7445 * Bug fixes (of course!)
7447 There have been loads of fixes for the following things:
7448 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7449 i960, stabs, DOS(GO32), procfs, etc...
7451 See the ChangeLog for details.
7453 *** Changes in GDB-4.5:
7455 * New machines supported (host and target)
7457 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7459 SGI Irix-4.x mips-sgi-irix4 or iris4
7461 * New malloc package
7463 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7464 Mmalloc is capable of handling multiple heaps of memory. It is also
7465 capable of saving a heap to a file, and then mapping it back in later.
7466 This can be used to greatly speedup the startup of GDB by using a
7467 pre-parsed symbol table which lives in a mmalloc managed heap. For
7468 more details, please read mmalloc/mmalloc.texi.
7472 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7473 'help info proc' for details.
7475 * MIPS ecoff symbol table format
7477 The code that reads MIPS symbol table format is now supported on all hosts.
7478 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7481 * File name changes for MS-DOS
7483 Many files in the config directories have been renamed to make it easier to
7484 support GDB on MS-DOSe systems (which have very restrictive file name
7485 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7486 environment) is close to working but has some remaining problems. Note
7487 that debugging of DOS programs is not supported, due to limitations
7488 in the ``operating system'', but it can be used to host cross-debugging.
7490 * Cross byte order fixes
7492 Many fixes have been made to support cross debugging of Sparc and MIPS
7493 targets from hosts whose byte order differs.
7495 * New -mapped and -readnow options
7497 If memory-mapped files are available on your system through the 'mmap'
7498 system call, you can use the -mapped option on the `file' or
7499 `symbol-file' commands to cause GDB to write the symbols from your
7500 program into a reusable file. If the program you are debugging is
7501 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7502 Future GDB debugging sessions will notice the presence of this file,
7503 and will quickly map in symbol information from it, rather than reading
7504 the symbol table from the executable program. Using the '-mapped'
7505 option in a GDB `file' or `symbol-file' command has the same effect as
7506 starting GDB with the '-mapped' command-line option.
7508 You can cause GDB to read the entire symbol table immediately by using
7509 the '-readnow' option with any of the commands that load symbol table
7510 information (or on the GDB command line). This makes the command
7511 slower, but makes future operations faster.
7513 The -mapped and -readnow options are typically combined in order to
7514 build a `fred.syms' file that contains complete symbol information.
7515 A simple GDB invocation to do nothing but build a `.syms' file for future
7518 gdb -batch -nx -mapped -readnow programname
7520 The `.syms' file is specific to the host machine on which GDB is run.
7521 It holds an exact image of GDB's internal symbol table. It cannot be
7522 shared across multiple host platforms.
7524 * longjmp() handling
7526 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7527 siglongjmp() without losing control. This feature has not yet been ported to
7528 all systems. It currently works on many 386 platforms, all MIPS-based
7529 platforms (SGI, DECstation, etc), and Sun3/4.
7533 Preliminary work has been put in to support the new Solaris OS from Sun. At
7534 this time, it can control and debug processes, but it is not capable of
7539 As always, many many bug fixes. The major areas were with g++, and mipsread.
7540 People using the MIPS-based platforms should experience fewer mysterious
7541 crashes and trashed symbol tables.
7543 *** Changes in GDB-4.4:
7545 * New machines supported (host and target)
7547 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7549 BSD Reno on Vax vax-dec-bsd
7550 Ultrix on Vax vax-dec-ultrix
7552 * New machines supported (target)
7554 AMD 29000 embedded, using EBMON a29k-none-none
7558 GDB continues to improve its handling of C++. `References' work better.
7559 The demangler has also been improved, and now deals with symbols mangled as
7560 per the Annotated C++ Reference Guide.
7562 GDB also now handles `stabs' symbol information embedded in MIPS
7563 `ecoff' symbol tables. Since the ecoff format was not easily
7564 extensible to handle new languages such as C++, this appeared to be a
7565 good way to put C++ debugging info into MIPS binaries. This option
7566 will be supported in the GNU C compiler, version 2, when it is
7569 * New features for SVR4
7571 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7572 shared libraries. Debugging dynamically linked programs should present
7573 only minor differences from debugging statically linked programs.
7575 The `info proc' command will print out information about any process
7576 on an SVR4 system (including the one you are debugging). At the moment,
7577 it prints the address mappings of the process.
7579 If you bring up GDB on another SVR4 system, please send mail to
7580 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7582 * Better dynamic linking support in SunOS
7584 Reading symbols from shared libraries which contain debugging symbols
7585 now works properly. However, there remain issues such as automatic
7586 skipping of `transfer vector' code during function calls, which
7587 make it harder to debug code in a shared library, than to debug the
7588 same code linked statically.
7592 GDB is now using the latest `getopt' routines from the FSF. This
7593 version accepts the -- prefix for options with long names. GDB will
7594 continue to accept the old forms (-option and +option) as well.
7595 Various single letter abbreviations for options have been explicity
7596 added to the option table so that they won't get overshadowed in the
7597 future by other options that begin with the same letter.
7601 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7602 Many assorted bugs have been handled. Many more remain to be handled.
7603 See the various ChangeLog files (primarily in gdb and bfd) for details.
7606 *** Changes in GDB-4.3:
7608 * New machines supported (host and target)
7610 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7611 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7612 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7614 * Almost SCO Unix support
7616 We had hoped to support:
7617 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7618 (except for core file support), but we discovered very late in the release
7619 that it has problems with process groups that render gdb unusable. Sorry
7620 about that. I encourage people to fix it and post the fixes.
7622 * Preliminary ELF and DWARF support
7624 GDB can read ELF object files on System V Release 4, and can handle
7625 debugging records for C, in DWARF format, in ELF files. This support
7626 is preliminary. If you bring up GDB on another SVR4 system, please
7627 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7632 GDB now uses the latest `readline' library. One user-visible change
7633 is that two tabs will list possible command completions, which previously
7634 required typing M-? (meta-question mark, or ESC ?).
7638 The `stepi' bug that many of you noticed has been squashed.
7639 Many bugs in C++ have been handled. Many more remain to be handled.
7640 See the various ChangeLog files (primarily in gdb and bfd) for details.
7642 * State of the MIPS world (in case you wondered):
7644 GDB can understand the symbol tables emitted by the compilers
7645 supplied by most vendors of MIPS-based machines, including DEC. These
7646 symbol tables are in a format that essentially nobody else uses.
7648 Some versions of gcc come with an assembler post-processor called
7649 mips-tfile. This program is required if you want to do source-level
7650 debugging of gcc-compiled programs. I believe FSF does not ship
7651 mips-tfile with gcc version 1, but it will eventually come with gcc
7654 Debugging of g++ output remains a problem. g++ version 1.xx does not
7655 really support it at all. (If you're lucky, you should be able to get
7656 line numbers and stack traces to work, but no parameters or local
7657 variables.) With some work it should be possible to improve the
7660 When gcc version 2 is released, you will have somewhat better luck.
7661 However, even then you will get confusing results for inheritance and
7664 We will eventually provide full debugging of g++ output on
7665 DECstations. This will probably involve some kind of stabs-in-ecoff
7666 encapulation, but the details have not been worked out yet.
7669 *** Changes in GDB-4.2:
7671 * Improved configuration
7673 Only one copy of `configure' exists now, and it is not self-modifying.
7674 Porting BFD is simpler.
7678 The `step' and `next' commands now only stop at the first instruction
7679 of a source line. This prevents the multiple stops that used to occur
7680 in switch statements, for-loops, etc. `Step' continues to stop if a
7681 function that has debugging information is called within the line.
7685 Lots of small bugs fixed. More remain.
7687 * New host supported (not target)
7689 Intel 386 PC clone running Mach i386-none-mach
7692 *** Changes in GDB-4.1:
7694 * Multiple source language support
7696 GDB now has internal scaffolding to handle several source languages.
7697 It determines the type of each source file from its filename extension,
7698 and will switch expression parsing and number formatting to match the
7699 language of the function in the currently selected stack frame.
7700 You can also specifically set the language to be used, with
7701 `set language c' or `set language modula-2'.
7705 GDB now has preliminary support for the GNU Modula-2 compiler,
7706 currently under development at the State University of New York at
7707 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7708 continue through the fall of 1991 and into 1992.
7710 Other Modula-2 compilers are currently not supported, and attempting to
7711 debug programs compiled with them will likely result in an error as the
7712 symbol table is read. Feel free to work on it, though!
7714 There are hooks in GDB for strict type checking and range checking,
7715 in the `Modula-2 philosophy', but they do not currently work.
7719 GDB can now write to executable and core files (e.g. patch
7720 a variable's value). You must turn this switch on, specify
7721 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7722 by assigning a new value to a variable. Modifications take
7725 * Automatic SunOS shared library reading
7727 When you run your program, GDB automatically determines where its
7728 shared libraries (if any) have been loaded, and reads their symbols.
7729 The `share' command is no longer needed. This also works when
7730 examining core files.
7734 You can specify the number of lines that the `list' command shows.
7737 * New machines supported (host and target)
7739 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7740 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7741 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7743 * New hosts supported (not targets)
7745 IBM RT/PC: romp-ibm-aix or rtpc
7747 * New targets supported (not hosts)
7749 AMD 29000 embedded with COFF a29k-none-coff
7750 AMD 29000 embedded with a.out a29k-none-aout
7751 Ultracomputer remote kernel debug a29k-nyu-kern
7753 * New remote interfaces
7759 *** Changes in GDB-4.0:
7763 Wide output is wrapped at good places to make the output more readable.
7765 Gdb now supports cross-debugging from a host machine of one type to a
7766 target machine of another type. Communication with the target system
7767 is over serial lines. The ``target'' command handles connecting to the
7768 remote system; the ``load'' command will download a program into the
7769 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7770 also supports debugging of realtime processes running under VxWorks,
7771 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7772 stub on the target system.
7774 New CPUs supported include the AMD 29000 and Intel 960.
7776 GDB now reads object files and symbol tables via a ``binary file''
7777 library, which allows a single copy of GDB to debug programs of multiple
7778 object file types such as a.out and coff.
7780 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7781 refcard.dvi and refcard.ps are available to format it).
7784 * Control-Variable user interface simplified
7786 All variables that control the operation of the debugger can be set
7787 by the ``set'' command, and displayed by the ``show'' command.
7789 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7790 ``Show prompt'' produces the response:
7791 Gdb's prompt is new-gdb=>.
7793 What follows are the NEW set commands. The command ``help set'' will
7794 print a complete list of old and new set commands. ``help set FOO''
7795 will give a longer description of the variable FOO. ``show'' will show
7796 all of the variable descriptions and their current settings.
7798 confirm on/off: Enables warning questions for operations that are
7799 hard to recover from, e.g. rerunning the program while
7800 it is already running. Default is ON.
7802 editing on/off: Enables EMACS style command line editing
7803 of input. Previous lines can be recalled with
7804 control-P, the current line can be edited with control-B,
7805 you can search for commands with control-R, etc.
7808 history filename NAME: NAME is where the gdb command history
7809 will be stored. The default is .gdb_history,
7810 or the value of the environment variable
7813 history size N: The size, in commands, of the command history. The
7814 default is 256, or the value of the environment variable
7817 history save on/off: If this value is set to ON, the history file will
7818 be saved after exiting gdb. If set to OFF, the
7819 file will not be saved. The default is OFF.
7821 history expansion on/off: If this value is set to ON, then csh-like
7822 history expansion will be performed on
7823 command line input. The default is OFF.
7825 radix N: Sets the default radix for input and output. It can be set
7826 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7827 in the current radix, so "set radix 10" is always a no-op.
7829 height N: This integer value is the number of lines on a page. Default
7830 is 24, the current `stty rows'' setting, or the ``li#''
7831 setting from the termcap entry matching the environment
7834 width N: This integer value is the number of characters on a line.
7835 Default is 80, the current `stty cols'' setting, or the ``co#''
7836 setting from the termcap entry matching the environment
7839 Note: ``set screensize'' is obsolete. Use ``set height'' and
7840 ``set width'' instead.
7842 print address on/off: Print memory addresses in various command displays,
7843 such as stack traces and structure values. Gdb looks
7844 more ``symbolic'' if you turn this off; it looks more
7845 ``machine level'' with it on. Default is ON.
7847 print array on/off: Prettyprint arrays. New convenient format! Default
7850 print demangle on/off: Print C++ symbols in "source" form if on,
7853 print asm-demangle on/off: Same, for assembler level printouts
7856 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7859 * Support for Epoch Environment.
7861 The epoch environment is a version of Emacs v18 with windowing. One
7862 new command, ``inspect'', is identical to ``print'', except that if you
7863 are running in the epoch environment, the value is printed in its own
7867 * Support for Shared Libraries
7869 GDB can now debug programs and core files that use SunOS shared libraries.
7870 Symbols from a shared library cannot be referenced
7871 before the shared library has been linked with the program (this
7872 happens after you type ``run'' and before the function main() is entered).
7873 At any time after this linking (including when examining core files
7874 from dynamically linked programs), gdb reads the symbols from each
7875 shared library when you type the ``sharedlibrary'' command.
7876 It can be abbreviated ``share''.
7878 sharedlibrary REGEXP: Load shared object library symbols for files
7879 matching a unix regular expression. No argument
7880 indicates to load symbols for all shared libraries.
7882 info sharedlibrary: Status of loaded shared libraries.
7887 A watchpoint stops execution of a program whenever the value of an
7888 expression changes. Checking for this slows down execution
7889 tremendously whenever you are in the scope of the expression, but is
7890 quite useful for catching tough ``bit-spreader'' or pointer misuse
7891 problems. Some machines such as the 386 have hardware for doing this
7892 more quickly, and future versions of gdb will use this hardware.
7894 watch EXP: Set a watchpoint (breakpoint) for an expression.
7896 info watchpoints: Information about your watchpoints.
7898 delete N: Deletes watchpoint number N (same as breakpoints).
7899 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7900 enable N: Re-enables watchpoint number N (same as breakpoints).
7903 * C++ multiple inheritance
7905 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7908 * C++ exception handling
7910 Gdb now supports limited C++ exception handling. Besides the existing
7911 ability to breakpoint on an exception handler, gdb can breakpoint on
7912 the raising of an exception (before the stack is peeled back to the
7915 catch FOO: If there is a FOO exception handler in the dynamic scope,
7916 set a breakpoint to catch exceptions which may be raised there.
7917 Multiple exceptions (``catch foo bar baz'') may be caught.
7919 info catch: Lists all exceptions which may be caught in the
7920 current stack frame.
7923 * Minor command changes
7925 The command ``call func (arg, arg, ...)'' now acts like the print
7926 command, except it does not print or save a value if the function's result
7927 is void. This is similar to dbx usage.
7929 The ``up'' and ``down'' commands now always print the frame they end up
7930 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7931 frames without printing.
7933 * New directory command
7935 'dir' now adds directories to the FRONT of the source search path.
7936 The path starts off empty. Source files that contain debug information
7937 about the directory in which they were compiled can be found even
7938 with an empty path; Sun CC and GCC include this information. If GDB can't
7939 find your source file in the current directory, type "dir .".
7941 * Configuring GDB for compilation
7943 For normal use, type ``./configure host''. See README or gdb.texinfo
7946 GDB now handles cross debugging. If you are remotely debugging between
7947 two different machines, type ``./configure host -target=targ''.
7948 Host is the machine where GDB will run; targ is the machine
7949 where the program that you are debugging will run.