1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
15 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
16 of the GDB settings and the GDB maintenance settings. They are handy
17 for changing the logic of user defined commands depending on the
20 * GDB now supports Thread Local Storage (TLS) variables on several
21 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
22 architectures require kernel changes. TLS is not yet supported for
23 amd64 and i386 process core dumps.
25 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
26 addresses that required unmasking are shown in the backtrace with the
29 * Two new convenience functions $_cimag and $_creal that extract the
30 imaginary and real parts respectively from complex numbers.
32 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
33 provide the exitcode or exit status of the shell commands launched by
34 GDB commands such as "shell", "pipe" and "make".
36 * The command define-prefix can now define user defined prefix commands.
37 User defined commands can now be defined using these user defined prefix
40 * Command names can now use the . character.
42 * The RX port now supports XML target descriptions.
44 * GDB now shows the Ada task names at more places, e.g. in task switching
47 * GDB can now be compiled with Python 3 on Windows.
49 * New convenience variable $_ada_exception holds the address of the
50 Ada exception being thrown. This is set by Ada-related catchpoints.
52 * GDB can now place breakpoints on nested functions and subroutines in
53 Fortran code. The '::' operator can be used between parent and
54 child scopes when placing breakpoints, for example:
56 (gdb) break outer_function::inner_function
58 The 'outer_function::' prefix is only needed if 'inner_function' is
59 not visible in the current scope.
61 * In addition to the system-wide gdbinit file, if configured with
62 --with-system-gdbinit-dir, GDB will now also load files in that directory
63 as system gdbinit files, unless the -nx or -n flag is provided. Files
64 with extensions .gdb, .py and .scm are supported as long as GDB was
65 compiled with support for that language.
67 * GDB now supports multithreaded symbol loading for higher performance.
68 This feature is still in testing, so it is disabled by default. You
69 can turn it on using 'maint set worker-threads unlimited'.
73 ** The gdb.Value type has a new method 'format_string' which returns a
74 string representing the value. The formatting is controlled by the
75 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
76 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
77 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
79 ** gdb.Type has a new property 'objfile' which returns the objfile the
82 ** The frame information printed by the python frame filtering code
83 is now consistent with what the 'backtrace' command prints when
84 there are no filters, or when the 'backtrace' '-no-filters' option
87 ** The new function gdb.lookup_static_symbol can be used to look up
88 symbols with static linkage.
90 ** The new function gdb.lookup_static_symbols can be used to look up
91 all static symbols with static linkage.
93 ** gdb.Objfile has new methods 'lookup_global_symbol' and
94 'lookup_static_symbol' to lookup a symbol from this objfile only.
96 ** gdb.Block now supports the dictionary syntax for accessing symbols in
97 this block (e.g. block['local_variable']).
101 | [COMMAND] | SHELL_COMMAND
102 | -d DELIM COMMAND DELIM SHELL_COMMAND
103 pipe [COMMAND] | SHELL_COMMAND
104 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
105 Executes COMMAND and sends its output to SHELL_COMMAND.
106 With no COMMAND, repeat the last executed command
107 and send its output to SHELL_COMMAND.
109 define-prefix COMMAND
110 Define or mark a command as a user-defined prefix command.
112 with SETTING [VALUE] [-- COMMAND]
113 w SETTING [VALUE] [-- COMMAND]
114 Temporarily set SETTING, run COMMAND, and restore SETTING.
115 Usage: with SETTING -- COMMAND
116 With no COMMAND, repeats the last executed command.
117 SETTING is any GDB setting you can change with the "set"
118 subcommands. For example, 'with language c -- print someobj'
119 temporarily switches to the C language in order to print someobj.
120 Settings can be combined: 'w lang c -- w print elements unlimited --
121 usercmd' switches to the C language and runs usercmd with no limit
122 of array elements to print.
124 maint with SETTING [VALUE] [-- COMMAND]
125 Like "with", but works with "maintenance set" settings.
127 set may-call-functions [on|off]
128 show may-call-functions
129 This controls whether GDB will attempt to call functions in
130 the program, such as with expressions in the print command. It
131 defaults to on. Calling functions in the program being debugged
132 can have undesired side effects. It is now possible to forbid
133 such function calls. If function calls are forbidden, GDB will throw
134 an error when a command (such as print expression) calls a function
137 set print finish [on|off]
139 This controls whether the `finish' command will display the value
140 that is returned by the current function. When `off', the value is
141 still entered into the value history, but it is not printed. The
146 Allows deeply nested structures to be simplified when printing by
147 replacing deeply nested parts (beyond the max-depth) with ellipses.
148 The default max-depth is 20, but this can be set to unlimited to get
149 the old behavior back.
151 set print raw-values [on|off]
152 show print raw-values
153 By default, GDB applies the enabled pretty printers when printing a
154 value. This allows to ignore the enabled pretty printers for a series
155 of commands. The default is 'off'.
157 set logging debugredirect [on|off]
158 By default, GDB debug output will go to both the terminal and the logfile.
159 Set if you want debug output to go only to the log file.
161 set style title foreground COLOR
162 set style title background COLOR
163 set style title intensity VALUE
164 Control the styling of titles.
166 set style highlight foreground COLOR
167 set style highlight background COLOR
168 set style highlight intensity VALUE
169 Control the styling of highlightings.
171 maint set worker-threads
172 maint show worker-threads
173 Control the number of worker threads that can be used by GDB. The
174 default is 0. "unlimited" lets GDB choose a number that is
175 reasonable. Currently worker threads are only used when demangling
176 the names of linker symbols.
178 set style tui-border foreground COLOR
179 set style tui-border background COLOR
180 Control the styling of TUI borders.
182 set style tui-active-border foreground COLOR
183 set style tui-active-border background COLOR
184 Control the styling of the active TUI border.
186 maint set test-settings KIND
187 maint show test-settings KIND
188 A set of commands used by the testsuite for exercising the settings
191 maint set tui-resize-message [on|off]
192 maint show tui-resize-message
193 Control whether GDB prints a message each time the terminal is
194 resized when in TUI mode. This is primarily useful for testing the
197 set print frame-info [short-location|location|location-and-address
198 |source-and-location|source-line|auto]
199 show print frame-info
200 This controls what frame information is printed by the commands printing
201 a frame. This setting will e.g. influence the behaviour of 'backtrace',
202 'frame', 'stepi'. The python frame filtering also respect this setting.
203 The 'backtrace' '-frame-info' option can override this global setting.
205 set tui compact-source
206 show tui compact-source
208 Enable the "compact" display mode for the TUI source window. The
209 compact display uses only as much space as is needed for the line
210 numbers in the current file, and only a single space to separate the
211 line numbers from the source.
213 info modules [-q] [REGEXP]
214 Return a list of Fortran modules matching REGEXP, or all modules if
217 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
218 Return a list of functions within all modules, grouped by module.
219 The list of functions can be restricted with the optional regular
220 expressions. MODULE_REGEXP matches against the module name,
221 TYPE_REGEXP matches against the function type signature, and REGEXP
222 matches against the function name.
224 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
225 Return a list of variables within all modules, grouped by module.
226 The list of variables can be restricted with the optional regular
227 expressions. MODULE_REGEXP matches against the module name,
228 TYPE_REGEXP matches against the variable type, and REGEXP matches
229 against the variable name.
231 set debug remote-packet-max-chars
232 show debug remote-packet-max-chars
233 Controls the number of characters to output in a remote packet when using
235 The default is 512 bytes.
240 The "help" command uses the title style to enhance the
241 readibility of its output by styling the classes and
245 Similarly to "help", the "apropos" command also uses the
246 title style for the command names. "apropos" accepts now
247 a flag "-v" (verbose) to show the full documentation
248 of matching commands and to use the highlight style to mark
249 the documentation parts matching REGEXP.
253 The GDB printf and eval commands can now print C-style and Ada-style
254 string convenience variables without calling functions in the program.
255 This allows to do formatted printing of strings without having
256 a running inferior, or when debugging a core dump.
258 info sources [-dirname | -basename] [--] [REGEXP]
259 This command has now optional arguments to only print the files
260 whose names match REGEXP. The arguments -dirname and -basename
261 allow to restrict matching respectively to the dirname and basename
265 The "show style" and its subcommands are now styling
266 a style name in their output using its own style, to help
267 the user visualize the different styles.
269 set print frame-arguments
270 The new value 'presence' indicates to only indicate the presence of
271 arguments using ..., instead of printing argument names and values.
273 set print raw-frame-arguments
274 show print raw-frame-arguments
276 These commands replace the similarly-named "set/show print raw
277 frame-arguments" commands (now with a dash instead of a space). The
278 old commands are now deprecated and may be removed in a future
281 maint test-options require-delimiter
282 maint test-options unknown-is-error
283 maint test-options unknown-is-operand
284 maint show test-options-completion-result
285 Commands used by the testsuite to validate the command options
288 focus, winheight, +, -, >, <
289 These commands are now case-sensitive.
291 * New command options, command completion
293 GDB now has a standard infrastructure to support dash-style command
294 options ('-OPT'). One benefit is that commands that use it can
295 easily support completion of command line arguments. Try "CMD
296 -[TAB]" or "help CMD" to find options supported by a command. Over
297 time, we intend to migrate most commands to this infrastructure. A
298 number of commands got support for new command options in this
301 ** The "print" and "compile print" commands now support a number of
302 options that allow overriding relevant global print settings as
303 set by "set print" subcommands:
307 -array-indexes [on|off]
308 -elements NUMBER|unlimited
313 -repeats NUMBER|unlimited
314 -static-members [on|off]
319 Note that because the "print"/"compile print" commands accept
320 arbitrary expressions which may look like options (including
321 abbreviations), if you specify any command option, then you must
322 use a double dash ("--") to mark the end of argument processing.
324 ** The "backtrace" command now supports a number of options that
325 allow overriding relevant global print settings as set by "set
326 backtrace" and "set print" subcommands:
328 -entry-values no|only|preferred|if-needed|both|compact|default
329 -frame-arguments all|scalars|none
330 -raw-frame-arguments [on|off]
331 -frame-info auto|source-line|location|source-and-location
332 |location-and-address|short-location
336 In addition, the full/no-filters/hide qualifiers are now also
337 exposed as command options too:
343 ** The "frame apply", "tfaas" and "faas" commands similarly now
344 support the following options:
349 ** The new "info sources" options -dirname and -basename options
350 are using the standard '-OPT' infrastructure.
352 All options above can also be abbreviated. The argument of boolean
353 (on/off) options can be 0/1 too, and also the argument is assumed
354 "on" if omitted. This allows writing compact command invocations,
357 (gdb) p -ra -p -o 0 -- *myptr
359 The above is equivalent to:
361 (gdb) print -raw-values -pretty -object off -- *myptr
363 ** The "info types" command now supports the '-q' flag to disable
364 printing of some header information in a similar fashion to "info
365 variables" and "info functions".
367 ** The "info variables", "info functions", and "whereis" commands
368 now take a '-n' flag that excludes non-debug symbols (symbols
369 from the symbol table, not from the debug info such as DWARF)
372 * Completion improvements
374 ** GDB can now complete the options of the "thread apply all" and
375 "taas" commands, and their "-ascending" option can now be
378 ** GDB can now complete the options of the "info threads", "info
379 functions", "info variables", "info locals", and "info args"
382 ** GDB can now complete the options of the "compile file" and
383 "compile code" commands. The "compile file" command now
384 completes on filenames.
386 ** GDB can now complete the backtrace command's
387 "full/no-filters/hide" qualifiers.
389 * In settings, you can now abbreviate "unlimited".
391 E.g., "set print elements u" is now equivalent to "set print
397 This lists all the possible completions for the rest of the line, if it
398 were to be given as a command itself. This is intended for use by MI
399 frontends in cases when separate CLI and MI channels cannot be used.
401 -catch-throw, -catch-rethrow, and -catch-catch
402 These can be used to catch C++ exceptions in a similar fashion to
403 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
405 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
406 These commands are the MI equivalent of the CLI commands 'info
407 functions', 'info types', and 'info variables' respectively.
409 -symbol-info-modules, this is the MI equivalent of the CLI 'info
412 -symbol-info-module-functions and -symbol-info-module-variables.
413 These commands are the MI equivalent of the CLI commands 'info
414 module functions' and 'info module variables'.
418 ** The default version of the MI interpreter is now 3 (-i=mi3).
420 ** The output of information about multi-location breakpoints (which is
421 syntactically incorrect in MI 2) has changed in MI 3. This affects
422 the following commands and events:
426 - =breakpoint-created
427 - =breakpoint-modified
429 The -fix-multi-location-breakpoint-output command can be used to enable
430 this behavior with previous MI versions.
432 ** Backtraces and frames include a new optional field addr_flags which is
433 given after the addr field. On AArch64 this contains PAC if the address
434 has been masked in the frame. On all other targets the field is not
439 The testsuite now creates the files gdb.cmd (containing the arguments
440 used to launch GDB) and gdb.in (containing all the commands sent to
441 GDB) in the output directory for each test script. Multiple invocations
442 are appended with .1, .2, .3 etc.
444 * Building GDB and GDBserver now requires GNU make >= 3.82.
446 Using another implementation of the make program or an earlier version of
447 GNU make to build GDB or GDBserver is not supported.
449 * Building GDB now requires GNU readline >= 7.0.
451 GDB now bundles GNU readline 8.0, but if you choose to use
452 --with-system-readline, only readline >= 7.0 can be used.
454 * The TUI SingleKey keymap is now named "SingleKey". This can be used
455 from .inputrc to bind keys in this keymap. This feature is only
456 available when gdb is built against GNU readline 8.0 or later.
458 * Removed targets and native configurations
460 GDB no longer supports debugging the Cell Broadband Engine. This includes
461 both debugging standalone Cell/B.E. SPU applications and integrated debugging
462 of Cell/B.E. applications that use both the PPU and SPU architectures.
468 * Removed targets and native configurations
470 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
473 *** Changes in GDB 8.3
475 * GDB and GDBserver now support access to additional registers on
476 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
479 * GDB now has experimental support for the compilation and injection of
480 C++ source code into the inferior. This beta release does not include
481 support for several language features, such as templates, constructors,
484 This feature requires GCC 7.1 or higher built with libcp1.so
487 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
488 can be passed using the '[ADDRESS]:PORT' notation, or the regular
489 'ADDRESS:PORT' method.
491 * DWARF index cache: GDB can now automatically save indices of DWARF
492 symbols on disk to speed up further loading of the same binaries.
494 * Ada task switching is now supported on aarch64-elf targets when
495 debugging a program using the Ravenscar Profile. For more information,
496 see the "Tasking Support when using the Ravenscar Profile" section
497 in the GDB user manual.
499 * GDB in batch mode now exits with status 1 if the last command to be
502 * The RISC-V target now supports target descriptions.
504 * System call catchpoints now support system call aliases on FreeBSD.
505 When the ABI of a system call changes in FreeBSD, this is
506 implemented by leaving a compatibility system call using the old ABI
507 at the existing number and allocating a new system call number for
508 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
509 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
510 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
511 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
512 so that a system call catchpoint for the 'kevent' system call will
513 catch invocations of both the 'kevent' and 'freebsd11_kevent'
514 binaries. This ensures that 'kevent' system calls are caught for
515 binaries using either the old or new ABIs.
517 * Terminal styling is now available for the CLI and the TUI. GNU
518 Source Highlight can additionally be used to provide styling of
519 source code snippets. See the "set style" commands, below, for more
522 * Removed support for old demangling styles arm, edg, gnu, hp and
527 set debug compile-cplus-types
528 show debug compile-cplus-types
529 Control the display of debug output about type conversion in the
530 C++ compile feature. Commands have no effect while compiliong
535 Control whether debug output about files/functions skipping is
538 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
539 Apply a command to some frames.
540 FLAG arguments allow to control what output to produce and how to handle
541 errors raised when applying COMMAND to a frame.
544 Apply a command to all threads (ignoring errors and empty output).
545 Shortcut for 'thread apply all -s COMMAND'.
548 Apply a command to all frames (ignoring errors and empty output).
549 Shortcut for 'frame apply all -s COMMAND'.
552 Apply a command to all frames of all threads (ignoring errors and empty
554 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
556 maint set dwarf unwinders (on|off)
557 maint show dwarf unwinders
558 Control whether DWARF unwinders can be used.
561 Display a list of open files for a process.
565 Changes to the "frame", "select-frame", and "info frame" CLI commands.
566 These commands all now take a frame specification which
567 is either a frame level, or one of the keywords 'level', 'address',
568 'function', or 'view' followed by a parameter. Selecting a frame by
569 address, or viewing a frame outside the current backtrace now
570 requires the use of a keyword. Selecting a frame by level is
571 unchanged. The MI comment "-stack-select-frame" is unchanged.
573 target remote FILENAME
574 target extended-remote FILENAME
575 If FILENAME is a Unix domain socket, GDB will attempt to connect
576 to this socket instead of opening FILENAME as a character device.
578 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
579 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
580 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
581 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
582 These commands can now print only the searched entities
583 matching the provided regexp(s), giving a condition
584 on the entity names or entity types. The flag -q disables
585 printing headers or informations messages.
591 These commands now determine the syntax for the shown entities
592 according to the language chosen by `set language'. In particular,
593 `set language auto' means to automatically choose the language of
596 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
597 The 'thread apply' command accepts new FLAG arguments.
598 FLAG arguments allow to control what output to produce and how to handle
599 errors raised when applying COMMAND to a thread.
601 set tui tab-width NCHARS
602 show tui tab-width NCHARS
603 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
605 set style enabled [on|off]
607 Enable or disable terminal styling. Styling is enabled by default
608 on most hosts, but disabled by default when in batch mode.
610 set style sources [on|off]
612 Enable or disable source code styling. Source code styling is
613 enabled by default, but only takes effect if styling in general is
614 enabled, and if GDB was linked with GNU Source Highlight.
616 set style filename foreground COLOR
617 set style filename background COLOR
618 set style filename intensity VALUE
619 Control the styling of file names.
621 set style function foreground COLOR
622 set style function background COLOR
623 set style function intensity VALUE
624 Control the styling of function names.
626 set style variable foreground COLOR
627 set style variable background COLOR
628 set style variable intensity VALUE
629 Control the styling of variable names.
631 set style address foreground COLOR
632 set style address background COLOR
633 set style address intensity VALUE
634 Control the styling of addresses.
638 ** The '-data-disassemble' MI command now accepts an '-a' option to
639 disassemble the whole function surrounding the given program
640 counter value or function name. Support for this feature can be
641 verified by using the "-list-features" command, which should
642 contain "data-disassemble-a-option".
644 ** Command responses and notifications that include a frame now include
645 the frame's architecture in a new "arch" attribute.
647 * New native configurations
649 GNU/Linux/RISC-V riscv*-*-linux*
650 FreeBSD/riscv riscv*-*-freebsd*
654 GNU/Linux/RISC-V riscv*-*-linux*
656 CSKY GNU/LINUX csky*-*-linux
657 FreeBSD/riscv riscv*-*-freebsd*
659 GNU/Linux/OpenRISC or1k*-*-linux*
663 GDB no longer supports native debugging on versions of MS-Windows
668 ** GDB no longer supports Python versions less than 2.6.
670 ** The gdb.Inferior type has a new 'progspace' property, which is the program
671 space associated to that inferior.
673 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
674 of objfiles associated to that program space.
676 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
677 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
680 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
681 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
682 correct and did not work properly.
684 ** The gdb.Value type has a new constructor, which is used to construct a
685 gdb.Value from a Python buffer object and a gdb.Type.
691 Enable or disable the undefined behavior sanitizer. This is
692 disabled by default, but passing --enable-ubsan=yes or
693 --enable-ubsan=auto to configure will enable it. Enabling this can
694 cause a performance penalty. The undefined behavior sanitizer was
695 first introduced in GCC 4.9.
697 *** Changes in GDB 8.2
699 * The 'set disassembler-options' command now supports specifying options
702 * The 'symbol-file' command now accepts an '-o' option to add a relative
703 offset to all sections.
705 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
706 a relative offset to all sections, but it allows to override the load
707 address of individual sections using '-s'.
709 * The 'add-symbol-file' command no longer requires the second argument
710 (address of the text section).
712 * The endianness used with the 'set endian auto' mode in the absence of
713 an executable selected for debugging is now the last endianness chosen
714 either by one of the 'set endian big' and 'set endian little' commands
715 or by inferring from the last executable used, rather than the startup
718 * The pager now allows a "c" response, meaning to disable the pager
719 for the rest of the current command.
721 * The commands 'info variables/functions/types' now show the source line
722 numbers of symbol definitions when available.
724 * 'info proc' now works on running processes on FreeBSD systems and core
725 files created on FreeBSD systems.
727 * C expressions can now use _Alignof, and C++ expressions can now use
730 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
731 the vector length while the process is running.
737 Control display of debugging info regarding the FreeBSD native target.
739 set|show varsize-limit
740 This new setting allows the user to control the maximum size of Ada
741 objects being printed when those objects have a variable type,
742 instead of that maximum size being hardcoded to 65536 bytes.
744 set|show record btrace cpu
745 Controls the processor to be used for enabling errata workarounds for
748 maint check libthread-db
749 Run integrity checks on the current inferior's thread debugging
752 maint set check-libthread-db (on|off)
753 maint show check-libthread-db
754 Control whether to run integrity checks on inferior specific thread
755 debugging libraries as they are loaded. The default is not to
760 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
762 ** The commands attached to a breakpoint can be set by assigning to
763 the breakpoint's "commands" field.
765 ** gdb.execute can now execute multi-line gdb commands.
767 ** The new functions gdb.convenience_variable and
768 gdb.set_convenience_variable can be used to get and set the value
769 of convenience variables.
771 ** A gdb.Parameter will no longer print the "set" help text on an
772 ordinary "set"; instead by default a "set" will be silent unless
773 the get_set_string method returns a non-empty string.
777 RiscV ELF riscv*-*-elf
779 * Removed targets and native configurations
781 m88k running OpenBSD m88*-*-openbsd*
782 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
783 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
784 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
786 * Aarch64/Linux hardware watchpoints improvements
788 Hardware watchpoints on unaligned addresses are now properly
789 supported when running Linux kernel 4.10 or higher: read and access
790 watchpoints are no longer spuriously missed, and all watchpoints
791 lengths between 1 and 8 bytes are supported. On older kernels,
792 watchpoints set on unaligned addresses are no longer missed, with
793 the tradeoff that there is a possibility of false hits being
798 --enable-codesign=CERT
799 This can be used to invoke "codesign -s CERT" after building gdb.
800 This option is useful on macOS, where code signing is required for
801 gdb to work properly.
803 --disable-gdbcli has been removed
804 This is now silently accepted, but does nothing.
806 *** Changes in GDB 8.1
808 * GDB now supports dynamically creating arbitrary register groups specified
809 in XML target descriptions. This allows for finer grain grouping of
810 registers on systems with a large amount of registers.
812 * The 'ptype' command now accepts a '/o' flag, which prints the
813 offsets and sizes of fields in a struct, like the pahole(1) tool.
815 * New "--readnever" command line option instructs GDB to not read each
816 symbol file's symbolic debug information. This makes startup faster
817 but at the expense of not being able to perform symbolic debugging.
818 This option is intended for use cases where symbolic debugging will
819 not be used, e.g., when you only need to dump the debuggee's core.
821 * GDB now uses the GNU MPFR library, if available, to emulate target
822 floating-point arithmetic during expression evaluation when the target
823 uses different floating-point formats than the host. At least version
824 3.1 of GNU MPFR is required.
826 * GDB now supports access to the guarded-storage-control registers and the
827 software-based guarded-storage broadcast control registers on IBM z14.
829 * On Unix systems, GDB now supports transmitting environment variables
830 that are to be set or unset to GDBserver. These variables will
831 affect the environment to be passed to the remote inferior.
833 To inform GDB of environment variables that are to be transmitted to
834 GDBserver, use the "set environment" command. Only user set
835 environment variables are sent to GDBserver.
837 To inform GDB of environment variables that are to be unset before
838 the remote inferior is started by the GDBserver, use the "unset
839 environment" command.
841 * Completion improvements
843 ** GDB can now complete function parameters in linespecs and
844 explicit locations without quoting. When setting breakpoints,
845 quoting around functions names to help with TAB-completion is
846 generally no longer necessary. For example, this now completes
849 (gdb) b function(in[TAB]
850 (gdb) b function(int)
852 Related, GDB is no longer confused with completing functions in
853 C++ anonymous namespaces:
856 (gdb) b (anonymous namespace)::[TAB][TAB]
857 (anonymous namespace)::a_function()
858 (anonymous namespace)::b_function()
860 ** GDB now has much improved linespec and explicit locations TAB
861 completion support, that better understands what you're
862 completing and offers better suggestions. For example, GDB no
863 longer offers data symbols as possible completions when you're
864 setting a breakpoint.
866 ** GDB now TAB-completes label symbol names.
868 ** The "complete" command now mimics TAB completion accurately.
870 * New command line options (gcore)
873 Dump all memory mappings.
875 * Breakpoints on C++ functions are now set on all scopes by default
877 By default, breakpoints on functions/methods are now interpreted as
878 specifying all functions with the given name ignoring missing
879 leading scopes (namespaces and classes).
881 For example, assuming a C++ program with symbols named:
886 both commands "break func()" and "break B::func()" set a breakpoint
889 You can use the new flag "-qualified" to override this. This makes
890 GDB interpret the specified function name as a complete
891 fully-qualified name instead. For example, using the same C++
892 program, the "break -q B::func" command sets a breakpoint on
893 "B::func", only. A parameter has been added to the Python
894 gdb.Breakpoint constructor to achieve the same result when creating
895 a breakpoint from Python.
897 * Breakpoints on functions marked with C++ ABI tags
899 GDB can now set breakpoints on functions marked with C++ ABI tags
900 (e.g., [abi:cxx11]). See here for a description of ABI tags:
901 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
903 Functions with a C++11 abi tag are demangled/displayed like this:
905 function[abi:cxx11](int)
908 You can now set a breakpoint on such functions simply as if they had
911 (gdb) b function(int)
913 Or if you need to disambiguate between tags, like:
915 (gdb) b function[abi:other_tag](int)
917 Tab completion was adjusted accordingly as well.
921 ** New events gdb.new_inferior, gdb.inferior_deleted, and
922 gdb.new_thread are emitted. See the manual for further
923 description of these.
925 ** A new function, "gdb.rbreak" has been added to the Python API.
926 This function allows the setting of a large number of breakpoints
927 via a regex pattern in Python. See the manual for further details.
929 ** Python breakpoints can now accept explicit locations. See the
930 manual for a further description of this feature.
933 * New features in the GDB remote stub, GDBserver
935 ** GDBserver is now able to start inferior processes with a
936 specified initial working directory.
938 The user can set the desired working directory to be used from
939 GDB using the new "set cwd" command.
941 ** New "--selftest" command line option runs some GDBserver self
942 tests. These self tests are disabled in releases.
944 ** On Unix systems, GDBserver now does globbing expansion and variable
945 substitution in inferior command line arguments.
947 This is done by starting inferiors using a shell, like GDB does.
948 See "set startup-with-shell" in the user manual for how to disable
949 this from GDB when using "target extended-remote". When using
950 "target remote", you can disable the startup with shell by using the
951 new "--no-startup-with-shell" GDBserver command line option.
953 ** On Unix systems, GDBserver now supports receiving environment
954 variables that are to be set or unset from GDB. These variables
955 will affect the environment to be passed to the inferior.
957 * When catching an Ada exception raised with a message, GDB now prints
958 the message in the catchpoint hit notification. In GDB/MI mode, that
959 information is provided as an extra field named "exception-message"
960 in the *stopped notification.
962 * Trait objects can now be inspected When debugging Rust code. This
963 requires compiler support which will appear in Rust 1.24.
967 QEnvironmentHexEncoded
968 Inform GDBserver of an environment variable that is to be passed to
969 the inferior when starting it.
972 Inform GDBserver of an environment variable that is to be unset
973 before starting the remote inferior.
976 Inform GDBserver that the environment should be reset (i.e.,
977 user-set environment variables should be unset).
980 Indicates whether the inferior must be started with a shell or not.
983 Tell GDBserver that the inferior to be started should use a specific
986 * The "maintenance print c-tdesc" command now takes an optional
987 argument which is the file name of XML target description.
989 * The "maintenance selftest" command now takes an optional argument to
990 filter the tests to be run.
992 * The "enable", and "disable" commands now accept a range of
993 breakpoint locations, e.g. "enable 1.3-5".
998 Set and show the current working directory for the inferior.
1000 set|show compile-gcc
1001 Set and show compilation command used for compiling and injecting code
1002 with the 'compile' commands.
1004 set debug separate-debug-file
1005 show debug separate-debug-file
1006 Control the display of debug output about separate debug file search.
1008 set dump-excluded-mappings
1009 show dump-excluded-mappings
1010 Control whether mappings marked with the VM_DONTDUMP flag should be
1011 dumped when generating a core file.
1013 maint info selftests
1014 List the registered selftests.
1017 Start the debugged program stopping at the first instruction.
1020 Control display of debugging messages related to OpenRISC targets.
1022 set|show print type nested-type-limit
1023 Set and show the limit of nesting level for nested types that the
1024 type printer will show.
1026 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1029 * Safer/improved support for debugging with no debug info
1031 GDB no longer assumes functions with no debug information return
1034 This means that GDB now refuses to call such functions unless you
1035 tell it the function's type, by either casting the call to the
1036 declared return type, or by casting the function to a function
1037 pointer of the right type, and calling that:
1039 (gdb) p getenv ("PATH")
1040 'getenv' has unknown return type; cast the call to its declared return type
1041 (gdb) p (char *) getenv ("PATH")
1042 $1 = 0x7fffffffe "/usr/local/bin:/"...
1043 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1044 $2 = 0x7fffffffe "/usr/local/bin:/"...
1046 Similarly, GDB no longer assumes that global variables with no debug
1047 info have type 'int', and refuses to print the variable's value
1048 unless you tell it the variable's type:
1051 'var' has unknown type; cast it to its declared type
1055 * New native configurations
1057 FreeBSD/aarch64 aarch64*-*-freebsd*
1058 FreeBSD/arm arm*-*-freebsd*
1062 FreeBSD/aarch64 aarch64*-*-freebsd*
1063 FreeBSD/arm arm*-*-freebsd*
1064 OpenRISC ELF or1k*-*-elf
1066 * Removed targets and native configurations
1068 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1070 *** Changes in GDB 8.0
1072 * GDB now supports access to the PKU register on GNU/Linux. The register is
1073 added by the Memory Protection Keys for Userspace feature which will be
1074 available in future Intel CPUs.
1076 * GDB now supports C++11 rvalue references.
1080 ** New functions to start, stop and access a running btrace recording.
1081 ** Rvalue references are now supported in gdb.Type.
1083 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1086 * Building GDB and GDBserver now requires a C++11 compiler.
1088 For example, GCC 4.8 or later.
1090 It is no longer possible to build GDB or GDBserver with a C
1091 compiler. The --disable-build-with-cxx configure option has been
1094 * Building GDB and GDBserver now requires GNU make >= 3.81.
1096 It is no longer supported to build GDB or GDBserver with another
1097 implementation of the make program or an earlier version of GNU make.
1099 * Native debugging on MS-Windows supports command-line redirection
1101 Command-line arguments used for starting programs on MS-Windows can
1102 now include redirection symbols supported by native Windows shells,
1103 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1104 as "run", "start", and "set args", as well as the corresponding MI
1107 * Support for thread names on MS-Windows.
1109 GDB now catches and handles the special exception that programs
1110 running on MS-Windows use to assign names to threads in the
1113 * Support for Java programs compiled with gcj has been removed.
1115 * User commands now accept an unlimited number of arguments.
1116 Previously, only up to 10 was accepted.
1118 * The "eval" command now expands user-defined command arguments.
1120 This makes it easier to process a variable number of arguments:
1125 eval "print $arg%d", $i
1130 * Target descriptions can now describe registers for sparc32 and sparc64.
1132 * GDB now supports DWARF version 5 (debug information format).
1133 Its .debug_names index is not yet supported.
1135 * New native configurations
1137 FreeBSD/mips mips*-*-freebsd
1141 Synopsys ARC arc*-*-elf32
1142 FreeBSD/mips mips*-*-freebsd
1144 * Removed targets and native configurations
1146 Alpha running FreeBSD alpha*-*-freebsd*
1147 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1152 Erases all the flash memory regions reported by the target.
1154 maint print arc arc-instruction address
1155 Print internal disassembler information about instruction at a given address.
1159 set disassembler-options
1160 show disassembler-options
1161 Controls the passing of target specific information to the disassembler.
1162 If it is necessary to specify more than one disassembler option then
1163 multiple options can be placed together into a comma separated list.
1164 The default value is the empty string. Currently, the only supported
1165 targets are ARM, PowerPC and S/390.
1170 Erases all the flash memory regions reported by the target. This is
1171 equivalent to the CLI command flash-erase.
1173 -file-list-shared-libraries
1174 List the shared libraries in the program. This is
1175 equivalent to the CLI command "info shared".
1178 Catchpoints stopping the program when Ada exceptions are
1179 handled. This is equivalent to the CLI command "catch handlers".
1181 *** Changes in GDB 7.12
1183 * GDB and GDBserver now build with a C++ compiler by default.
1185 The --enable-build-with-cxx configure option is now enabled by
1186 default. One must now explicitly configure with
1187 --disable-build-with-cxx in order to build with a C compiler. This
1188 option will be removed in a future release.
1190 * GDBserver now supports recording btrace without maintaining an active
1193 * GDB now supports a negative repeat count in the 'x' command to examine
1194 memory backward from the given address. For example:
1197 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1198 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1199 (gdb) x/-5i 0x0000000000400580
1200 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1201 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1202 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1203 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1204 0x40057b <main(int, char**)+25>:
1205 callq 0x400536 <Func1(int, char const*)>
1207 * Fortran: Support structures with fields of dynamic types and
1208 arrays of dynamic types.
1210 * The symbol dumping maintenance commands have new syntax.
1211 maint print symbols [-pc address] [--] [filename]
1212 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1213 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1214 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1215 maint print msymbols [-objfile objfile] [--] [filename]
1217 * GDB now supports multibit bitfields and enums in target register
1220 * New Python-based convenience function $_as_string(val), which returns
1221 the textual representation of a value. This function is especially
1222 useful to obtain the text label of an enum value.
1224 * Intel MPX bound violation handling.
1226 Segmentation faults caused by a Intel MPX boundary violation
1227 now display the kind of violation (upper or lower), the memory
1228 address accessed and the memory bounds, along with the usual
1229 signal received and code location.
1233 Program received signal SIGSEGV, Segmentation fault
1234 Upper bound violation while accessing address 0x7fffffffc3b3
1235 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1236 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1238 * Rust language support.
1239 GDB now supports debugging programs written in the Rust programming
1240 language. See https://www.rust-lang.org/ for more information about
1243 * Support for running interpreters on specified input/output devices
1245 GDB now supports a new mechanism that allows frontends to provide
1246 fully featured GDB console views, as a better alternative to
1247 building such views on top of the "-interpreter-exec console"
1248 command. See the new "new-ui" command below. With that command,
1249 frontends can now start GDB in the traditional command-line mode
1250 running in an embedded terminal emulator widget, and create a
1251 separate MI interpreter running on a specified i/o device. In this
1252 way, GDB handles line editing, history, tab completion, etc. in the
1253 console all by itself, and the GUI uses the separate MI interpreter
1254 for its own control and synchronization, invisible to the command
1257 * The "catch syscall" command catches groups of related syscalls.
1259 The "catch syscall" command now supports catching a group of related
1260 syscalls using the 'group:' or 'g:' prefix.
1265 skip -gfile file-glob-pattern
1266 skip -function function
1267 skip -rfunction regular-expression
1268 A generalized form of the skip command, with new support for
1269 glob-style file names and regular expressions for function names.
1270 Additionally, a file spec and a function spec may now be combined.
1272 maint info line-table REGEXP
1273 Display the contents of GDB's internal line table data struture.
1276 Run any GDB unit tests that were compiled in.
1279 Start a new user interface instance running INTERP as interpreter,
1280 using the TTY file for input/output.
1284 ** gdb.Breakpoint objects have a new attribute "pending", which
1285 indicates whether the breakpoint is pending.
1286 ** Three new breakpoint-related events have been added:
1287 gdb.breakpoint_created, gdb.breakpoint_modified, and
1288 gdb.breakpoint_deleted.
1290 signal-event EVENTID
1291 Signal ("set") the given MS-Windows event object. This is used in
1292 conjunction with the Windows JIT debugging (AeDebug) support, where
1293 the OS suspends a crashing process until a debugger can attach to
1294 it. Resuming the crashing process, in order to debug it, is done by
1295 signalling an event.
1297 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1298 was added in GDBserver, including JIT compiling fast tracepoint's
1299 conditional expression bytecode into native code.
1301 * Support for various remote target protocols and ROM monitors has
1304 target m32rsdi Remote M32R debugging over SDI
1305 target mips MIPS remote debugging protocol
1306 target pmon PMON ROM monitor
1307 target ddb NEC's DDB variant of PMON for Vr4300
1308 target rockhopper NEC RockHopper variant of PMON
1309 target lsi LSI variant of PMO
1311 * Support for tracepoints and fast tracepoints on powerpc-linux,
1312 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1313 including JIT compiling fast tracepoint's conditional expression
1314 bytecode into native code.
1316 * MI async record =record-started now includes the method and format used for
1317 recording. For example:
1319 =record-started,thread-group="i1",method="btrace",format="bts"
1321 * MI async record =thread-selected now includes the frame field. For example:
1323 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1327 Andes NDS32 nds32*-*-elf
1329 *** Changes in GDB 7.11
1331 * GDB now supports debugging kernel-based threads on FreeBSD.
1333 * Per-inferior thread numbers
1335 Thread numbers are now per inferior instead of global. If you're
1336 debugging multiple inferiors, GDB displays thread IDs using a
1337 qualified INF_NUM.THR_NUM form. For example:
1341 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1342 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1343 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1344 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1346 As consequence, thread numbers as visible in the $_thread
1347 convenience variable and in Python's InferiorThread.num attribute
1348 are no longer unique between inferiors.
1350 GDB now maintains a second thread ID per thread, referred to as the
1351 global thread ID, which is the new equivalent of thread numbers in
1352 previous releases. See also $_gthread below.
1354 For backwards compatibility, MI's thread IDs always refer to global
1357 * Commands that accept thread IDs now accept the qualified
1358 INF_NUM.THR_NUM form as well. For example:
1361 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1364 * In commands that accept a list of thread IDs, you can now refer to
1365 all threads of an inferior using a star wildcard. GDB accepts
1366 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1367 refer to all threads of the current inferior. For example, "info
1370 * You can use "info threads -gid" to display the global thread ID of
1373 * The new convenience variable $_gthread holds the global number of
1376 * The new convenience variable $_inferior holds the number of the
1379 * GDB now displays the ID and name of the thread that hit a breakpoint
1380 or received a signal, if your program is multi-threaded. For
1383 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1384 Thread 1 "main" received signal SIGINT, Interrupt.
1386 * Record btrace now supports non-stop mode.
1388 * Support for tracepoints on aarch64-linux was added in GDBserver.
1390 * The 'record instruction-history' command now indicates speculative execution
1391 when using the Intel Processor Trace recording format.
1393 * GDB now allows users to specify explicit locations, bypassing
1394 the linespec parser. This feature is also available to GDB/MI
1397 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1398 GDB now is able to debug both AArch64 applications and ARM applications
1401 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1402 including JIT compiling fast tracepoint's conditional expression bytecode
1405 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1407 * "info threads", "info inferiors", "info display", "info checkpoints"
1408 and "maint info program-spaces" now list the corresponding items in
1409 ascending ID order, for consistency with all other "info" commands.
1411 * In Ada, the overloads selection menu has been enhanced to display the
1412 parameter types and the return types for the matching overloaded subprograms.
1416 maint set target-non-stop (on|off|auto)
1417 maint show target-non-stop
1418 Control whether GDB targets always operate in non-stop mode even if
1419 "set non-stop" is "off". The default is "auto", meaning non-stop
1420 mode is enabled if supported by the target.
1422 maint set bfd-sharing
1423 maint show bfd-sharing
1424 Control the reuse of bfd objects.
1427 show debug bfd-cache
1428 Control display of debugging info regarding bfd caching.
1432 Control display of debugging info regarding FreeBSD threads.
1434 set remote multiprocess-extensions-packet
1435 show remote multiprocess-extensions-packet
1436 Set/show the use of the remote protocol multiprocess extensions.
1438 set remote thread-events
1439 show remote thread-events
1440 Set/show the use of thread create/exit events.
1442 set ada print-signatures on|off
1443 show ada print-signatures"
1444 Control whether parameter types and return types are displayed in overloads
1445 selection menus. It is activaled (@code{on}) by default.
1449 Controls the maximum size of memory, in bytes, that GDB will
1450 allocate for value contents. Prevents incorrect programs from
1451 causing GDB to allocate overly large buffers. Default is 64k.
1453 * The "disassemble" command accepts a new modifier: /s.
1454 It prints mixed source+disassembly like /m with two differences:
1455 - disassembled instructions are now printed in program order, and
1456 - and source for all relevant files is now printed.
1457 The "/m" option is now considered deprecated: its "source-centric"
1458 output hasn't proved useful in practice.
1460 * The "record instruction-history" command accepts a new modifier: /s.
1461 It behaves exactly like /m and prints mixed source+disassembly.
1463 * The "set scheduler-locking" command supports a new mode "replay".
1464 It behaves like "off" in record mode and like "on" in replay mode.
1466 * Support for various ROM monitors has been removed:
1468 target dbug dBUG ROM monitor for Motorola ColdFire
1469 target picobug Motorola picobug monitor
1470 target dink32 DINK32 ROM monitor for PowerPC
1471 target m32r Renesas M32R/D ROM monitor
1472 target mon2000 mon2000 ROM monitor
1473 target ppcbug PPCBUG ROM monitor for PowerPC
1475 * Support for reading/writing memory and extracting values on architectures
1476 whose memory is addressable in units of any integral multiple of 8 bits.
1479 Allows to break when an Ada exception is handled.
1481 * New remote packets
1484 Indicates that an exec system call was executed.
1486 exec-events feature in qSupported
1487 The qSupported packet allows GDB to request support for exec
1488 events using the new 'gdbfeature' exec-event, and the qSupported
1489 response can contain the corresponding 'stubfeature'. Set and
1490 show commands can be used to display whether these features are enabled.
1493 Equivalent to interrupting with the ^C character, but works in
1496 thread created stop reason (T05 create:...)
1497 Indicates that the thread was just created and is stopped at entry.
1499 thread exit stop reply (w exitcode;tid)
1500 Indicates that the thread has terminated.
1503 Enables/disables thread create and exit event reporting. For
1504 example, this is used in non-stop mode when GDB stops a set of
1505 threads and synchronously waits for the their corresponding stop
1506 replies. Without exit events, if one of the threads exits, GDB
1507 would hang forever not knowing that it should no longer expect a
1508 stop for that same thread.
1511 Indicates that there are no resumed threads left in the target (all
1512 threads are stopped). The remote stub reports support for this stop
1513 reply to GDB's qSupported query.
1516 Enables/disables catching syscalls from the inferior process.
1517 The remote stub reports support for this packet to GDB's qSupported query.
1519 syscall_entry stop reason
1520 Indicates that a syscall was just called.
1522 syscall_return stop reason
1523 Indicates that a syscall just returned.
1525 * Extended-remote exec events
1527 ** GDB now has support for exec events on extended-remote Linux targets.
1528 For such targets with Linux kernels 2.5.46 and later, this enables
1529 follow-exec-mode and exec catchpoints.
1531 set remote exec-event-feature-packet
1532 show remote exec-event-feature-packet
1533 Set/show the use of the remote exec event feature.
1535 * Thread names in remote protocol
1537 The reply to qXfer:threads:read may now include a name attribute for each
1540 * Target remote mode fork and exec events
1542 ** GDB now has support for fork and exec events on target remote mode
1543 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1544 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1545 fork and exec catchpoints.
1547 * Remote syscall events
1549 ** GDB now has support for catch syscall on remote Linux targets,
1550 currently enabled on x86/x86_64 architectures.
1552 set remote catch-syscall-packet
1553 show remote catch-syscall-packet
1554 Set/show the use of the remote catch syscall feature.
1558 ** The -var-set-format command now accepts the zero-hexadecimal
1559 format. It outputs data in hexadecimal format with zero-padding on the
1564 ** gdb.InferiorThread objects have a new attribute "global_num",
1565 which refers to the thread's global thread ID. The existing
1566 "num" attribute now refers to the thread's per-inferior number.
1567 See "Per-inferior thread numbers" above.
1568 ** gdb.InferiorThread objects have a new attribute "inferior", which
1569 is the Inferior object the thread belongs to.
1571 *** Changes in GDB 7.10
1573 * Support for process record-replay and reverse debugging on aarch64*-linux*
1574 targets has been added. GDB now supports recording of A64 instruction set
1575 including advance SIMD instructions.
1577 * Support for Sun's version of the "stabs" debug file format has been removed.
1579 * GDB now honors the content of the file /proc/PID/coredump_filter
1580 (PID is the process ID) on GNU/Linux systems. This file can be used
1581 to specify the types of memory mappings that will be included in a
1582 corefile. For more information, please refer to the manual page of
1583 "core(5)". GDB also has a new command: "set use-coredump-filter
1584 on|off". It allows to set whether GDB will read the content of the
1585 /proc/PID/coredump_filter file when generating a corefile.
1587 * The "info os" command on GNU/Linux can now display information on
1589 "info os cpus" Listing of all cpus/cores on the system
1591 * GDB has two new commands: "set serial parity odd|even|none" and
1592 "show serial parity". These allows to set or show parity for the
1595 * The "info source" command now displays the producer string if it was
1596 present in the debug info. This typically includes the compiler version
1597 and may include things like its command line arguments.
1599 * The "info dll", an alias of the "info sharedlibrary" command,
1600 is now available on all platforms.
1602 * Directory names supplied to the "set sysroot" commands may be
1603 prefixed with "target:" to tell GDB to access shared libraries from
1604 the target system, be it local or remote. This replaces the prefix
1605 "remote:". The default sysroot has been changed from "" to
1606 "target:". "remote:" is automatically converted to "target:" for
1607 backward compatibility.
1609 * The system root specified by "set sysroot" will be prepended to the
1610 filename of the main executable (if reported to GDB as absolute by
1611 the operating system) when starting processes remotely, and when
1612 attaching to already-running local or remote processes.
1614 * GDB now supports automatic location and retrieval of executable
1615 files from remote targets. Remote debugging can now be initiated
1616 using only a "target remote" or "target extended-remote" command
1617 (no "set sysroot" or "file" commands are required). See "New remote
1620 * The "dump" command now supports verilog hex format.
1622 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1624 * On GNU/Linux, GDB and gdbserver are now able to access executable
1625 and shared library files without a "set sysroot" command when
1626 attaching to processes running in different mount namespaces from
1627 the debugger. This makes it possible to attach to processes in
1628 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1629 See "New remote packets" below.
1631 * The "tui reg" command now provides completion for all of the
1632 available register groups, including target specific groups.
1634 * The HISTSIZE environment variable is no longer read when determining
1635 the size of GDB's command history. GDB now instead reads the dedicated
1636 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1637 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1642 ** Memory ports can now be unbuffered.
1646 ** gdb.Objfile objects have a new attribute "username",
1647 which is the name of the objfile as specified by the user,
1648 without, for example, resolving symlinks.
1649 ** You can now write frame unwinders in Python.
1650 ** gdb.Type objects have a new method "optimized_out",
1651 returning optimized out gdb.Value instance of this type.
1652 ** gdb.Value objects have new methods "reference_value" and
1653 "const_value" which return a reference to the value and a
1654 "const" version of the value respectively.
1658 maint print symbol-cache
1659 Print the contents of the symbol cache.
1661 maint print symbol-cache-statistics
1662 Print statistics of symbol cache usage.
1664 maint flush-symbol-cache
1665 Flush the contents of the symbol cache.
1669 Start branch trace recording using Branch Trace Store (BTS) format.
1672 Evaluate expression by using the compiler and print result.
1676 Explicit commands for enabling and disabling tui mode.
1679 set mpx bound on i386 and amd64
1680 Support for bound table investigation on Intel MPX enabled applications.
1684 Start branch trace recording using Intel Processor Trace format.
1687 Print information about branch tracing internals.
1689 maint btrace packet-history
1690 Print the raw branch tracing data.
1692 maint btrace clear-packet-history
1693 Discard the stored raw branch tracing data.
1696 Discard all branch tracing data. It will be fetched and processed
1697 anew by the next "record" command.
1702 Renamed from "set debug dwarf2-die".
1703 show debug dwarf-die
1704 Renamed from "show debug dwarf2-die".
1706 set debug dwarf-read
1707 Renamed from "set debug dwarf2-read".
1708 show debug dwarf-read
1709 Renamed from "show debug dwarf2-read".
1711 maint set dwarf always-disassemble
1712 Renamed from "maint set dwarf2 always-disassemble".
1713 maint show dwarf always-disassemble
1714 Renamed from "maint show dwarf2 always-disassemble".
1716 maint set dwarf max-cache-age
1717 Renamed from "maint set dwarf2 max-cache-age".
1718 maint show dwarf max-cache-age
1719 Renamed from "maint show dwarf2 max-cache-age".
1721 set debug dwarf-line
1722 show debug dwarf-line
1723 Control display of debugging info regarding DWARF line processing.
1726 show max-completions
1727 Set the maximum number of candidates to be considered during
1728 completion. The default value is 200. This limit allows GDB
1729 to avoid generating large completion lists, the computation of
1730 which can cause the debugger to become temporarily unresponsive.
1732 set history remove-duplicates
1733 show history remove-duplicates
1734 Control the removal of duplicate history entries.
1736 maint set symbol-cache-size
1737 maint show symbol-cache-size
1738 Control the size of the symbol cache.
1740 set|show record btrace bts buffer-size
1741 Set and show the size of the ring buffer used for branch tracing in
1743 The obtained size may differ from the requested size. Use "info
1744 record" to see the obtained buffer size.
1746 set debug linux-namespaces
1747 show debug linux-namespaces
1748 Control display of debugging info regarding Linux namespaces.
1750 set|show record btrace pt buffer-size
1751 Set and show the size of the ring buffer used for branch tracing in
1752 Intel Processor Trace format.
1753 The obtained size may differ from the requested size. Use "info
1754 record" to see the obtained buffer size.
1756 maint set|show btrace pt skip-pad
1757 Set and show whether PAD packets are skipped when computing the
1760 * The command 'thread apply all' can now support new option '-ascending'
1761 to call its specified command for all threads in ascending order.
1763 * Python/Guile scripting
1765 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1766 special section named `.debug_gdb_scripts'.
1768 * New remote packets
1770 qXfer:btrace-conf:read
1771 Return the branch trace configuration for the current thread.
1773 Qbtrace-conf:bts:size
1774 Set the requested ring buffer size for branch tracing in BTS format.
1777 Enable Intel Procesor Trace-based branch tracing for the current
1778 process. The remote stub reports support for this packet to GDB's
1781 Qbtrace-conf:pt:size
1782 Set the requested ring buffer size for branch tracing in Intel Processor
1786 Indicates a memory breakpoint instruction was executed, irrespective
1787 of whether it was GDB that planted the breakpoint or the breakpoint
1788 is hardcoded in the program. This is required for correct non-stop
1792 Indicates the target stopped for a hardware breakpoint. This is
1793 required for correct non-stop mode operation.
1796 Return information about files on the remote system.
1798 qXfer:exec-file:read
1799 Return the full absolute name of the file that was executed to
1800 create a process running on the remote system.
1803 Select the filesystem on which vFile: operations with filename
1804 arguments will operate. This is required for GDB to be able to
1805 access files on remote targets where the remote stub does not
1806 share a common filesystem with the inferior(s).
1809 Indicates that a fork system call was executed.
1812 Indicates that a vfork system call was executed.
1814 vforkdone stop reason
1815 Indicates that a vfork child of the specified process has executed
1816 an exec or exit, allowing the vfork parent to resume execution.
1818 fork-events and vfork-events features in qSupported
1819 The qSupported packet allows GDB to request support for fork and
1820 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1821 and the qSupported response can contain the corresponding
1822 'stubfeatures'. Set and show commands can be used to display
1823 whether these features are enabled.
1825 * Extended-remote fork events
1827 ** GDB now has support for fork events on extended-remote Linux
1828 targets. For targets with Linux kernels 2.5.60 and later, this
1829 enables follow-fork-mode and detach-on-fork for both fork and
1830 vfork, as well as fork and vfork catchpoints.
1832 * The info record command now shows the recording format and the
1833 branch tracing configuration for the current thread when using
1834 the btrace record target.
1835 For the BTS format, it shows the ring buffer size.
1837 * GDB now has support for DTrace USDT (Userland Static Defined
1838 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1840 * GDB now supports access to vector registers on S/390 GNU/Linux
1843 * Removed command line options
1845 -xdb HP-UX XDB compatibility mode.
1847 * Removed targets and native configurations
1849 HP/PA running HP-UX hppa*-*-hpux*
1850 Itanium running HP-UX ia64-*-hpux*
1852 * New configure options
1855 This configure option allows the user to build GDB with support for
1856 Intel Processor Trace (default: auto). This requires libipt.
1858 --with-libipt-prefix=PATH
1859 Specify the path to the version of libipt that GDB should use.
1860 $PATH/include should contain the intel-pt.h header and
1861 $PATH/lib should contain the libipt.so library.
1863 *** Changes in GDB 7.9.1
1867 ** Xmethods can now specify a result type.
1869 *** Changes in GDB 7.9
1871 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1875 ** You can now access frame registers from Python scripts.
1876 ** New attribute 'producer' for gdb.Symtab objects.
1877 ** gdb.Objfile objects have a new attribute "progspace",
1878 which is the gdb.Progspace object of the containing program space.
1879 ** gdb.Objfile objects have a new attribute "owner".
1880 ** gdb.Objfile objects have a new attribute "build_id",
1881 which is the build ID generated when the file was built.
1882 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1883 ** A new event "gdb.clear_objfiles" has been added, triggered when
1884 selecting a new file to debug.
1885 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1886 ** New function gdb.lookup_objfile.
1888 New events which are triggered when GDB modifies the state of the
1891 ** gdb.events.inferior_call_pre: Function call is about to be made.
1892 ** gdb.events.inferior_call_post: Function call has just been made.
1893 ** gdb.events.memory_changed: A memory location has been altered.
1894 ** gdb.events.register_changed: A register has been altered.
1896 * New Python-based convenience functions:
1898 ** $_caller_is(name [, number_of_frames])
1899 ** $_caller_matches(regexp [, number_of_frames])
1900 ** $_any_caller_is(name [, number_of_frames])
1901 ** $_any_caller_matches(regexp [, number_of_frames])
1903 * GDB now supports the compilation and injection of source code into
1904 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1905 to compile the source code to object code, and if successful, inject
1906 and execute that code within the current context of the inferior.
1907 Currently the C language is supported. The commands used to
1908 interface with this new feature are:
1910 compile code [-raw|-r] [--] [source code]
1911 compile file [-raw|-r] filename
1915 demangle [-l language] [--] name
1916 Demangle "name" in the specified language, or the current language
1917 if elided. This command is renamed from the "maint demangle" command.
1918 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1919 as "maint demangler-warning".
1921 queue-signal signal-name-or-number
1922 Queue a signal to be delivered to the thread when it is resumed.
1924 add-auto-load-scripts-directory directory
1925 Add entries to the list of directories from which to load auto-loaded
1928 maint print user-registers
1929 List all currently available "user" registers.
1931 compile code [-r|-raw] [--] [source code]
1932 Compile, inject, and execute in the inferior the executable object
1933 code produced by compiling the provided source code.
1935 compile file [-r|-raw] filename
1936 Compile and inject into the inferior the executable object code
1937 produced by compiling the source code stored in the filename
1940 * On resume, GDB now always passes the signal the program had stopped
1941 for to the thread the signal was sent to, even if the user changed
1942 threads before resuming. Previously GDB would often (but not
1943 always) deliver the signal to the thread that happens to be current
1946 * Conversely, the "signal" command now consistently delivers the
1947 requested signal to the current thread. GDB now asks for
1948 confirmation if the program had stopped for a signal and the user
1949 switched threads meanwhile.
1951 * "breakpoint always-inserted" modes "off" and "auto" merged.
1953 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1954 won't remove breakpoints from the target until all threads stop,
1955 even in non-stop mode. The "auto" mode has been removed, and "off"
1956 is now the default mode.
1960 set debug symbol-lookup
1961 show debug symbol-lookup
1962 Control display of debugging info regarding symbol lookup.
1966 ** The -list-thread-groups command outputs an exit-code field for
1967 inferiors that have exited.
1971 MIPS SDE mips*-sde*-elf*
1975 Support for these obsolete configurations has been removed.
1977 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1978 SGI Irix-5.x mips-*-irix5*
1979 SGI Irix-6.x mips-*-irix6*
1980 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1981 VAX running Ultrix vax-*-ultrix*
1983 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1984 and "assf"), have been removed. Use the "sharedlibrary" command, or
1985 its alias "share", instead.
1987 *** Changes in GDB 7.8
1989 * New command line options
1992 This is an alias for the --data-directory option.
1994 * GDB supports printing and modifying of variable length automatic arrays
1995 as specified in ISO C99.
1997 * The ARM simulator now supports instruction level tracing
1998 with or without disassembly.
2002 GDB now has support for scripting using Guile. Whether this is
2003 available is determined at configure time.
2004 Guile version 2.0 or greater is required.
2005 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2007 * New commands (for set/show, see "New options" below)
2011 Invoke CODE by passing it to the Guile interpreter.
2015 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2017 info auto-load guile-scripts [regexp]
2018 Print the list of automatically loaded Guile scripts.
2020 * The source command is now capable of sourcing Guile scripts.
2021 This feature is dependent on the debugger being built with Guile support.
2025 set print symbol-loading (off|brief|full)
2026 show print symbol-loading
2027 Control whether to print informational messages when loading symbol
2028 information for a file. The default is "full", but when debugging
2029 programs with large numbers of shared libraries the amount of output
2030 becomes less useful.
2032 set guile print-stack (none|message|full)
2033 show guile print-stack
2034 Show a stack trace when an error is encountered in a Guile script.
2036 set auto-load guile-scripts (on|off)
2037 show auto-load guile-scripts
2038 Control auto-loading of Guile script files.
2040 maint ada set ignore-descriptive-types (on|off)
2041 maint ada show ignore-descriptive-types
2042 Control whether the debugger should ignore descriptive types in Ada
2043 programs. The default is not to ignore the descriptive types. See
2044 the user manual for more details on descriptive types and the intended
2045 usage of this option.
2047 set auto-connect-native-target
2049 Control whether GDB is allowed to automatically connect to the
2050 native target for the run, attach, etc. commands when not connected
2051 to any target yet. See also "target native" below.
2053 set record btrace replay-memory-access (read-only|read-write)
2054 show record btrace replay-memory-access
2055 Control what memory accesses are allowed during replay.
2057 maint set target-async (on|off)
2058 maint show target-async
2059 This controls whether GDB targets operate in synchronous or
2060 asynchronous mode. Normally the default is asynchronous, if it is
2061 available; but this can be changed to more easily debug problems
2062 occurring only in synchronous mode.
2064 set mi-async (on|off)
2066 Control whether MI asynchronous mode is preferred. This supersedes
2067 "set target-async" of previous GDB versions.
2069 * "set target-async" is deprecated as a CLI option and is now an alias
2070 for "set mi-async" (only puts MI into async mode).
2072 * Background execution commands (e.g., "c&", "s&", etc.) are now
2073 possible ``out of the box'' if the target supports them. Previously
2074 the user would need to explicitly enable the possibility with the
2075 "set target-async on" command.
2077 * New features in the GDB remote stub, GDBserver
2079 ** New option --debug-format=option1[,option2,...] allows one to add
2080 additional text to each output. At present only timestamps
2081 are supported: --debug-format=timestamps.
2082 Timestamps can also be turned on with the
2083 "monitor set debug-format timestamps" command from GDB.
2085 * The 'record instruction-history' command now starts counting instructions
2086 at one. This also affects the instruction ranges reported by the
2087 'record function-call-history' command when given the /i modifier.
2089 * The command 'record function-call-history' supports a new modifier '/c' to
2090 indent the function names based on their call stack depth.
2091 The fields for the '/i' and '/l' modifier have been reordered.
2092 The source line range is now prefixed with 'at'.
2093 The instruction range is now prefixed with 'inst'.
2094 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2095 "record instruction-history" and "list" commands.
2097 * The ranges given as arguments to the 'record function-call-history' and
2098 'record instruction-history' commands are now inclusive.
2100 * The btrace record target now supports the 'record goto' command.
2101 For locations inside the execution trace, the back trace is computed
2102 based on the information stored in the execution trace.
2104 * The btrace record target supports limited reverse execution and replay.
2105 The target does not record data and therefore does not allow reading
2106 memory or registers.
2108 * The "catch syscall" command now works on s390*-linux* targets.
2110 * The "compare-sections" command is no longer specific to target
2111 remote. It now works with all targets.
2113 * All native targets are now consistently called "native".
2114 Consequently, the "target child", "target GNU", "target djgpp",
2115 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2116 commands have been replaced with "target native". The QNX/NTO port
2117 leaves the "procfs" target in place and adds a "native" target for
2118 consistency with other ports. The impact on users should be minimal
2119 as these commands previously either throwed an error, or were
2120 no-ops. The target's name is visible in the output of the following
2121 commands: "help target", "info target", "info files", "maint print
2124 * The "target native" command now connects to the native target. This
2125 can be used to launch native programs even when "set
2126 auto-connect-native-target" is set to off.
2128 * GDB now supports access to Intel MPX registers on GNU/Linux.
2130 * Support for Intel AVX-512 registers on GNU/Linux.
2131 Support displaying and modifying Intel AVX-512 registers
2132 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2134 * New remote packets
2136 qXfer:btrace:read's annex
2137 The qXfer:btrace:read packet supports a new annex 'delta' to read
2138 branch trace incrementally.
2142 ** Valid Python operations on gdb.Value objects representing
2143 structs/classes invoke the corresponding overloaded operators if
2145 ** New `Xmethods' feature in the Python API. Xmethods are
2146 additional methods or replacements for existing methods of a C++
2147 class. This feature is useful for those cases where a method
2148 defined in C++ source code could be inlined or optimized out by
2149 the compiler, making it unavailable to GDB.
2152 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2154 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2155 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2156 its alias "share", instead.
2158 * The commands "set remotebaud" and "show remotebaud" are no longer
2159 supported. Use "set serial baud" and "show serial baud" (respectively)
2164 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2165 target-async". The latter is left as a deprecated alias of the
2166 former for backward compatibility. If the target supports it,
2167 CLI background execution commands are now always possible by
2168 default, independently of whether the frontend stated a
2169 preference for asynchronous execution with "-gdb-set mi-async".
2170 Previously "-gdb-set target-async off" affected both MI execution
2171 commands and CLI execution commands.
2173 *** Changes in GDB 7.7
2175 * Improved support for process record-replay and reverse debugging on
2176 arm*-linux* targets. Support for thumb32 and syscall instruction
2177 recording has been added.
2179 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2181 * GDB now supports Fission DWP file format version 2.
2182 http://gcc.gnu.org/wiki/DebugFission
2184 * New convenience function "$_isvoid", to check whether an expression
2185 is void. A void expression is an expression where the type of the
2186 result is "void". For example, some convenience variables may be
2187 "void" when evaluated (e.g., "$_exitcode" before the execution of
2188 the program being debugged; or an undefined convenience variable).
2189 Another example, when calling a function whose return type is
2192 * The "maintenance print objfiles" command now takes an optional regexp.
2194 * The "catch syscall" command now works on arm*-linux* targets.
2196 * GDB now consistently shows "<not saved>" when printing values of
2197 registers the debug info indicates have not been saved in the frame
2198 and there's nowhere to retrieve them from
2199 (callee-saved/call-clobbered registers):
2204 (gdb) info registers rax
2207 Before, the former would print "<optimized out>", and the latter
2208 "*value not available*".
2210 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2215 ** Frame filters and frame decorators have been added.
2216 ** Temporary breakpoints are now supported.
2217 ** Line tables representation has been added.
2218 ** New attribute 'parent_type' for gdb.Field objects.
2219 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2220 ** New attribute 'name' for gdb.Type objects.
2224 Nios II ELF nios2*-*-elf
2225 Nios II GNU/Linux nios2*-*-linux
2226 Texas Instruments MSP430 msp430*-*-elf
2228 * Removed native configurations
2230 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2231 been removed. ELF variants of these configurations are kept supported.
2233 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2234 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2235 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2236 i[34567]86-*-openbsd3.[0-3]
2237 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2238 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2239 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2243 Like "catch throw", but catches a re-thrown exception.
2244 maint check-psymtabs
2245 Renamed from old "maint check-symtabs".
2247 Perform consistency checks on symtabs.
2248 maint expand-symtabs
2249 Expand symtabs matching an optional regexp.
2252 Display the details of GDB configure-time options.
2254 maint set|show per-command
2255 maint set|show per-command space
2256 maint set|show per-command time
2257 maint set|show per-command symtab
2258 Enable display of per-command gdb resource usage.
2260 remove-symbol-file FILENAME
2261 remove-symbol-file -a ADDRESS
2262 Remove a symbol file added via add-symbol-file. The file to remove
2263 can be identified by its filename or by an address that lies within
2264 the boundaries of this symbol file in memory.
2267 info exceptions REGEXP
2268 Display the list of Ada exceptions defined in the program being
2269 debugged. If provided, only the exceptions whose names match REGEXP
2274 set debug symfile off|on
2276 Control display of debugging info regarding reading symbol files and
2277 symbol tables within those files
2279 set print raw frame-arguments
2280 show print raw frame-arguments
2281 Set/show whether to print frame arguments in raw mode,
2282 disregarding any defined pretty-printers.
2284 set remote trace-status-packet
2285 show remote trace-status-packet
2286 Set/show the use of remote protocol qTStatus packet.
2290 Control display of debugging messages related to Nios II targets.
2294 Control whether target-assisted range stepping is enabled.
2296 set startup-with-shell
2297 show startup-with-shell
2298 Specifies whether Unix child processes are started via a shell or
2303 Use the target memory cache for accesses to the code segment. This
2304 improves performance of remote debugging (particularly disassembly).
2306 * You can now use a literal value 'unlimited' for options that
2307 interpret 0 or -1 as meaning "unlimited". E.g., "set
2308 trace-buffer-size unlimited" is now an alias for "set
2309 trace-buffer-size -1" and "set height unlimited" is now an alias for
2312 * The "set debug symtab-create" debugging option of GDB has been changed to
2313 accept a verbosity level. 0 means "off", 1 provides basic debugging
2314 output, and values of 2 or greater provides more verbose output.
2316 * New command-line options
2318 Display the details of GDB configure-time options.
2320 * The command 'tsave' can now support new option '-ctf' to save trace
2321 buffer in Common Trace Format.
2323 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2326 * GDB now implements the the C++ 'typeid' operator.
2328 * The new convenience variable $_exception holds the exception being
2329 thrown or caught at an exception-related catchpoint.
2331 * The exception-related catchpoints, like "catch throw", now accept a
2332 regular expression which can be used to filter exceptions by type.
2334 * The new convenience variable $_exitsignal is automatically set to
2335 the terminating signal number when the program being debugged dies
2336 due to an uncaught signal.
2340 ** All MI commands now accept an optional "--language" option.
2341 Support for this feature can be verified by using the "-list-features"
2342 command, which should contain "language-option".
2344 ** The new command -info-gdb-mi-command allows the user to determine
2345 whether a GDB/MI command is supported or not.
2347 ** The "^error" result record returned when trying to execute an undefined
2348 GDB/MI command now provides a variable named "code" whose content is the
2349 "undefined-command" error code. Support for this feature can be verified
2350 by using the "-list-features" command, which should contain
2351 "undefined-command-error-code".
2353 ** The -trace-save MI command can optionally save trace buffer in Common
2356 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2358 ** The command -data-list-register-values now accepts an optional
2359 "--skip-unavailable" option. When used, only the available registers
2362 ** The new command -trace-frame-collected dumps collected variables,
2363 computed expressions, tvars, memory and registers in a traceframe.
2365 ** The commands -stack-list-locals, -stack-list-arguments and
2366 -stack-list-variables now accept an option "--skip-unavailable".
2367 When used, only the available locals or arguments are displayed.
2369 ** The -exec-run command now accepts an optional "--start" option.
2370 When used, the command follows the same semantics as the "start"
2371 command, stopping the program's execution at the start of its
2372 main subprogram. Support for this feature can be verified using
2373 the "-list-features" command, which should contain
2374 "exec-run-start-option".
2376 ** The new commands -catch-assert and -catch-exceptions insert
2377 catchpoints stopping the program when Ada exceptions are raised.
2379 ** The new command -info-ada-exceptions provides the equivalent of
2380 the new "info exceptions" command.
2382 * New system-wide configuration scripts
2383 A GDB installation now provides scripts suitable for use as system-wide
2384 configuration scripts for the following systems:
2388 * GDB now supports target-assigned range stepping with remote targets.
2389 This improves the performance of stepping source lines by reducing
2390 the number of control packets from/to GDB. See "New remote packets"
2393 * GDB now understands the element 'tvar' in the XML traceframe info.
2394 It has the id of the collected trace state variables.
2396 * On S/390 targets that provide the transactional-execution feature,
2397 the program interruption transaction diagnostic block (TDB) is now
2398 represented as a number of additional "registers" in GDB.
2400 * New remote packets
2404 The vCont packet supports a new 'r' action, that tells the remote
2405 stub to step through an address range itself, without GDB
2406 involvemement at each single-step.
2408 qXfer:libraries-svr4:read's annex
2409 The previously unused annex of the qXfer:libraries-svr4:read packet
2410 is now used to support passing an argument list. The remote stub
2411 reports support for this argument list to GDB's qSupported query.
2412 The defined arguments are "start" and "prev", used to reduce work
2413 necessary for library list updating, resulting in significant
2416 * New features in the GDB remote stub, GDBserver
2418 ** GDBserver now supports target-assisted range stepping. Currently
2419 enabled on x86/x86_64 GNU/Linux targets.
2421 ** GDBserver now adds element 'tvar' in the XML in the reply to
2422 'qXfer:traceframe-info:read'. It has the id of the collected
2423 trace state variables.
2425 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2428 * New 'z' formatter for printing and examining memory, this displays the
2429 value as hexadecimal zero padded on the left to the size of the type.
2431 * GDB can now use Windows x64 unwinding data.
2433 * The "set remotebaud" command has been replaced by "set serial baud".
2434 Similarly, "show remotebaud" has been replaced by "show serial baud".
2435 The "set remotebaud" and "show remotebaud" commands are still available
2436 to provide backward compatibility with older versions of GDB.
2438 *** Changes in GDB 7.6
2440 * Target record has been renamed to record-full.
2441 Record/replay is now enabled with the "record full" command.
2442 This also affects settings that are associated with full record/replay
2443 that have been moved from "set/show record" to "set/show record full":
2445 set|show record full insn-number-max
2446 set|show record full stop-at-limit
2447 set|show record full memory-query
2449 * A new record target "record-btrace" has been added. The new target
2450 uses hardware support to record the control-flow of a process. It
2451 does not support replaying the execution, but it implements the
2452 below new commands for investigating the recorded execution log.
2453 This new recording method can be enabled using:
2457 The "record-btrace" target is only available on Intel Atom processors
2458 and requires a Linux kernel 2.6.32 or later.
2460 * Two new commands have been added for record/replay to give information
2461 about the recorded execution without having to replay the execution.
2462 The commands are only supported by "record btrace".
2464 record instruction-history prints the execution history at
2465 instruction granularity
2467 record function-call-history prints the execution history at
2468 function granularity
2470 * New native configurations
2472 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2473 FreeBSD/powerpc powerpc*-*-freebsd
2474 x86_64/Cygwin x86_64-*-cygwin*
2475 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2479 ARM AArch64 aarch64*-*-elf
2480 ARM AArch64 GNU/Linux aarch64*-*-linux
2481 Lynx 178 PowerPC powerpc-*-lynx*178
2482 x86_64/Cygwin x86_64-*-cygwin*
2483 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2485 * If the configured location of system.gdbinit file (as given by the
2486 --with-system-gdbinit option at configure time) is in the
2487 data-directory (as specified by --with-gdb-datadir at configure
2488 time) or in one of its subdirectories, then GDB will look for the
2489 system-wide init file in the directory specified by the
2490 --data-directory command-line option.
2492 * New command line options:
2494 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2495 other initialization files, unlike -nx which disables all of them.
2497 * Removed command line options
2499 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2502 * The 'ptype' and 'whatis' commands now accept an argument to control
2505 * 'info proc' now works on some core files.
2509 ** Vectors can be created with gdb.Type.vector.
2511 ** Python's atexit.register now works in GDB.
2513 ** Types can be pretty-printed via a Python API.
2515 ** Python 3 is now supported (in addition to Python 2.4 or later)
2517 ** New class gdb.Architecture exposes GDB's internal representation
2518 of architecture in the Python API.
2520 ** New method Frame.architecture returns the gdb.Architecture object
2521 corresponding to the frame's architecture.
2523 * New Python-based convenience functions:
2525 ** $_memeq(buf1, buf2, length)
2526 ** $_streq(str1, str2)
2528 ** $_regex(str, regex)
2530 * The 'cd' command now defaults to using '~' (the home directory) if not
2533 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2534 default for GCC since November 2000.
2536 * The command 'forward-search' can now be abbreviated as 'fo'.
2538 * The command 'info tracepoints' can now display 'installed on target'
2539 or 'not installed on target' for each non-pending location of tracepoint.
2541 * New configure options
2543 --enable-libmcheck/--disable-libmcheck
2544 By default, development versions are built with -lmcheck on hosts
2545 that support it, in order to help track memory corruption issues.
2546 Release versions, on the other hand, are built without -lmcheck
2547 by default. The --enable-libmcheck/--disable-libmcheck configure
2548 options allow the user to override that default.
2549 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2550 This configure option allows the user to build GDB with
2551 libbabeltrace using which GDB can read Common Trace Format data.
2553 * New commands (for set/show, see "New options" below)
2556 Catch signals. This is similar to "handle", but allows commands and
2557 conditions to be attached.
2560 List the BFDs known to GDB.
2562 python-interactive [command]
2564 Start a Python interactive prompt, or evaluate the optional command
2565 and print the result of expressions.
2568 "py" is a new alias for "python".
2570 enable type-printer [name]...
2571 disable type-printer [name]...
2572 Enable or disable type printers.
2576 ** For the Renesas Super-H architecture, the "regs" command has been removed
2577 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2582 set print type methods (on|off)
2583 show print type methods
2584 Control whether method declarations are displayed by "ptype".
2585 The default is to show them.
2587 set print type typedefs (on|off)
2588 show print type typedefs
2589 Control whether typedef definitions are displayed by "ptype".
2590 The default is to show them.
2592 set filename-display basename|relative|absolute
2593 show filename-display
2594 Control the way in which filenames is displayed.
2595 The default is "relative", which preserves previous behavior.
2597 set trace-buffer-size
2598 show trace-buffer-size
2599 Request target to change the size of trace buffer.
2601 set remote trace-buffer-size-packet auto|on|off
2602 show remote trace-buffer-size-packet
2603 Control the use of the remote protocol `QTBuffer:size' packet.
2607 Control display of debugging messages related to ARM AArch64.
2610 set debug coff-pe-read
2611 show debug coff-pe-read
2612 Control display of debugging messages related to reading of COFF/PE
2617 Control display of debugging messages related to Mach-O symbols
2620 set debug notification
2621 show debug notification
2622 Control display of debugging info for async remote notification.
2626 ** Command parameter changes are now notified using new async record
2627 "=cmd-param-changed".
2628 ** Trace frame changes caused by command "tfind" are now notified using
2629 new async record "=traceframe-changed".
2630 ** The creation, deletion and modification of trace state variables
2631 are now notified using new async records "=tsv-created",
2632 "=tsv-deleted" and "=tsv-modified".
2633 ** The start and stop of process record are now notified using new
2634 async record "=record-started" and "=record-stopped".
2635 ** Memory changes are now notified using new async record
2637 ** The data-disassemble command response will include a "fullname" field
2638 containing the absolute file name when source has been requested.
2639 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2640 command, to allow pattern filling of memory areas.
2641 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2642 library load/unload events.
2643 ** The response to breakpoint commands and breakpoint async records
2644 includes an "installed" field containing a boolean state about each
2645 non-pending tracepoint location is whether installed on target or not.
2646 ** Output of the "-trace-status" command includes a "trace-file" field
2647 containing the name of the trace file being examined. This field is
2648 optional, and only present when examining a trace file.
2649 ** The "fullname" field is now always present along with the "file" field,
2650 even if the file cannot be found by GDB.
2652 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2653 You must have the LZMA library available when configuring GDB for this
2654 feature to be enabled. For more information, see:
2655 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2657 * New remote packets
2660 Set the size of trace buffer. The remote stub reports support for this
2661 packet to gdb's qSupported query.
2664 Enable Branch Trace Store (BTS)-based branch tracing for the current
2665 thread. The remote stub reports support for this packet to gdb's
2669 Disable branch tracing for the current thread. The remote stub reports
2670 support for this packet to gdb's qSupported query.
2673 Read the traced branches for the current thread. The remote stub
2674 reports support for this packet to gdb's qSupported query.
2676 *** Changes in GDB 7.5
2678 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2679 for more x32 ABI info.
2681 * GDB now supports access to MIPS DSP registers on Linux targets.
2683 * GDB now supports debugging microMIPS binaries.
2685 * The "info os" command on GNU/Linux can now display information on
2686 several new classes of objects managed by the operating system:
2687 "info os procgroups" lists process groups
2688 "info os files" lists file descriptors
2689 "info os sockets" lists internet-domain sockets
2690 "info os shm" lists shared-memory regions
2691 "info os semaphores" lists semaphores
2692 "info os msg" lists message queues
2693 "info os modules" lists loaded kernel modules
2695 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2696 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2697 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2698 options and inspect the probe arguments using the new $_probe_arg family
2699 of convenience variables. You can obtain more information about SystemTap
2700 in <http://sourceware.org/systemtap/>.
2702 * GDB now supports reversible debugging on ARM, it allows you to
2703 debug basic ARM and THUMB instructions, and provides
2704 record/replay support.
2706 * The option "symbol-reloading" has been deleted as it is no longer used.
2710 ** GDB commands implemented in Python can now be put in command class
2713 ** The "maint set python print-stack on|off" is now deleted.
2715 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2716 apply "flag enum"-style pretty-printing to any enum.
2718 ** gdb.lookup_symbol can now work when there is no current frame.
2720 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2721 the source at which the symbol was defined.
2723 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2724 method 'value'. The former indicates whether the symbol needs a
2725 frame in order to compute its value, and the latter computes the
2728 ** A new method 'referenced_value' on gdb.Value objects which can
2729 dereference pointer as well as C++ reference values.
2731 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2732 which return the global and static blocks (as gdb.Block objects),
2733 of the underlying symbol table, respectively.
2735 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2736 object associated with a PC value.
2738 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2739 of the address range occupied by code for the current source line.
2741 * Go language support.
2742 GDB now supports debugging programs written in the Go programming
2745 * GDBserver now supports stdio connections.
2746 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2748 * The binary "gdbtui" can no longer be built or installed.
2749 Use "gdb -tui" instead.
2751 * GDB will now print "flag" enums specially. A flag enum is one where
2752 all the enumerator values have no bits in common when pairwise
2753 "and"ed. When printing a value whose type is a flag enum, GDB will
2754 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2755 (gdb) print (enum E) 3
2758 * The filename part of a linespec will now match trailing components
2759 of a source file name. For example, "break gcc/expr.c:1000" will
2760 now set a breakpoint in build/gcc/expr.c, but not
2761 build/libcpp/expr.c.
2763 * The "info proc" and "generate-core-file" commands will now also
2764 work on remote targets connected to GDBserver on Linux.
2766 * The command "info catch" has been removed. It has been disabled
2767 since December 2007.
2769 * The "catch exception" and "catch assert" commands now accept
2770 a condition at the end of the command, much like the "break"
2771 command does. For instance:
2773 (gdb) catch exception Constraint_Error if Barrier = True
2775 Previously, it was possible to add a condition to such catchpoints,
2776 but it had to be done as a second step, after the catchpoint had been
2777 created, using the "condition" command.
2779 * The "info static-tracepoint-marker" command will now also work on
2780 native Linux targets with in-process agent.
2782 * GDB can now set breakpoints on inlined functions.
2784 * The .gdb_index section has been updated to include symbols for
2785 inlined functions. GDB will ignore older .gdb_index sections by
2786 default, which could cause symbol files to be loaded more slowly
2787 until their .gdb_index sections can be recreated. The new command
2788 "set use-deprecated-index-sections on" will cause GDB to use any older
2789 .gdb_index sections it finds. This will restore performance, but the
2790 ability to set breakpoints on inlined functions will be lost in symbol
2791 files with older .gdb_index sections.
2793 The .gdb_index section has also been updated to record more information
2794 about each symbol. This speeds up the "info variables", "info functions"
2795 and "info types" commands when used with programs having the .gdb_index
2796 section, as well as speeding up debugging with shared libraries using
2797 the .gdb_index section.
2799 * Ada support for GDB/MI Variable Objects has been added.
2801 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2806 ** New command -info-os is the MI equivalent of "info os".
2808 ** Output logs ("set logging" and related) now include MI output.
2812 ** "set use-deprecated-index-sections on|off"
2813 "show use-deprecated-index-sections on|off"
2814 Controls the use of deprecated .gdb_index sections.
2816 ** "catch load" and "catch unload" can be used to stop when a shared
2817 library is loaded or unloaded, respectively.
2819 ** "enable count" can be used to auto-disable a breakpoint after
2822 ** "info vtbl" can be used to show the virtual method tables for
2823 C++ and Java objects.
2825 ** "explore" and its sub commands "explore value" and "explore type"
2826 can be used to recursively explore values and types of
2827 expressions. These commands are available only if GDB is
2828 configured with '--with-python'.
2830 ** "info auto-load" shows status of all kinds of auto-loaded files,
2831 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2832 sequences of commands files, "info auto-load python-scripts"
2833 shows status of auto-loading Python script files,
2834 "info auto-load local-gdbinit" shows status of loading init file
2835 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2836 status of inferior specific thread debugging shared library loading.
2838 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2839 and "show auto-load-scripts" commands have been deprecated, use their
2840 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2841 and "show auto-load python-scripts" counterparts instead.
2843 ** "dprintf location,format,args..." creates a dynamic printf, which
2844 is basically a breakpoint that does a printf and immediately
2845 resumes your program's execution, so it is like a printf that you
2846 can insert dynamically at runtime instead of at compiletime.
2848 ** "set print symbol"
2850 Controls whether GDB attempts to display the symbol, if any,
2851 corresponding to addresses it prints. This defaults to "on", but
2852 you can set it to "off" to restore GDB's previous behavior.
2854 * Deprecated commands
2856 ** For the Renesas Super-H architecture, the "regs" command has been
2857 deprecated, and "info all-registers" should be used instead.
2861 Renesas RL78 rl78-*-elf
2862 HP OpenVMS ia64 ia64-hp-openvms*
2864 * GDBserver supports evaluation of breakpoint conditions. When
2865 support is advertised by GDBserver, GDB may be told to send the
2866 breakpoint conditions in bytecode form to GDBserver. GDBserver
2867 will only report the breakpoint trigger to GDB when its condition
2872 set mips compression
2873 show mips compression
2874 Select the compressed ISA encoding used in functions that have no symbol
2875 information available. The encoding can be set to either of:
2878 and is updated automatically from ELF file flags if available.
2880 set breakpoint condition-evaluation
2881 show breakpoint condition-evaluation
2882 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2883 GDBserver ("target"). Default option "auto" chooses the most efficient
2885 This option can improve debugger efficiency depending on the speed of the
2889 Disable auto-loading globally.
2892 Show auto-loading setting of all kinds of auto-loaded files.
2894 set auto-load gdb-scripts on|off
2895 show auto-load gdb-scripts
2896 Control auto-loading of GDB canned sequences of commands files.
2898 set auto-load python-scripts on|off
2899 show auto-load python-scripts
2900 Control auto-loading of Python script files.
2902 set auto-load local-gdbinit on|off
2903 show auto-load local-gdbinit
2904 Control loading of init file (.gdbinit) from current directory.
2906 set auto-load libthread-db on|off
2907 show auto-load libthread-db
2908 Control auto-loading of inferior specific thread debugging shared library.
2910 set auto-load scripts-directory <dir1>[:<dir2>...]
2911 show auto-load scripts-directory
2912 Set a list of directories from which to load auto-loaded scripts.
2913 Automatically loaded Python scripts and GDB scripts are located in one
2914 of the directories listed by this option.
2915 The delimiter (':' above) may differ according to the host platform.
2917 set auto-load safe-path <dir1>[:<dir2>...]
2918 show auto-load safe-path
2919 Set a list of directories from which it is safe to auto-load files.
2920 The delimiter (':' above) may differ according to the host platform.
2922 set debug auto-load on|off
2923 show debug auto-load
2924 Control display of debugging info for auto-loading the files above.
2926 set dprintf-style gdb|call|agent
2928 Control the way in which a dynamic printf is performed; "gdb"
2929 requests a GDB printf command, while "call" causes dprintf to call a
2930 function in the inferior. "agent" requests that the target agent
2931 (such as GDBserver) do the printing.
2933 set dprintf-function <expr>
2934 show dprintf-function
2935 set dprintf-channel <expr>
2936 show dprintf-channel
2937 Set the function and optional first argument to the call when using
2938 the "call" style of dynamic printf.
2940 set disconnected-dprintf on|off
2941 show disconnected-dprintf
2942 Control whether agent-style dynamic printfs continue to be in effect
2943 after GDB disconnects.
2945 * New configure options
2947 --with-auto-load-dir
2948 Configure default value for the 'set auto-load scripts-directory'
2949 setting above. It defaults to '$debugdir:$datadir/auto-load',
2950 $debugdir representing global debugging info directories (available
2951 via 'show debug-file-directory') and $datadir representing GDB's data
2952 directory (available via 'show data-directory').
2954 --with-auto-load-safe-path
2955 Configure default value for the 'set auto-load safe-path' setting
2956 above. It defaults to the --with-auto-load-dir setting.
2958 --without-auto-load-safe-path
2959 Set 'set auto-load safe-path' to '/', effectively disabling this
2962 * New remote packets
2964 z0/z1 conditional breakpoints extension
2966 The z0/z1 breakpoint insertion packets have been extended to carry
2967 a list of conditional expressions over to the remote stub depending on the
2968 condition evaluation mode. The use of this extension can be controlled
2969 via the "set remote conditional-breakpoints-packet" command.
2973 Specify the signals which the remote stub may pass to the debugged
2974 program without GDB involvement.
2976 * New command line options
2978 --init-command=FILE, -ix Like --command, -x but execute it
2979 before loading inferior.
2980 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2981 execute it before loading inferior.
2983 *** Changes in GDB 7.4
2985 * GDB now handles ambiguous linespecs more consistently; the existing
2986 FILE:LINE support has been expanded to other types of linespecs. A
2987 breakpoint will now be set on all matching locations in all
2988 inferiors, and locations will be added or removed according to
2991 * GDB now allows you to skip uninteresting functions and files when
2992 stepping with the "skip function" and "skip file" commands.
2994 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2995 and "show remote hardware-watchpoint-length-limit". These allows to
2996 set or show the maximum length limit (in bytes) of a remote
2997 target hardware watchpoint.
2999 This allows e.g. to use "unlimited" hardware watchpoints with the
3000 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3001 watchpoints are slower than real hardware watchpoints but are
3002 significantly faster than gdb software watchpoints.
3006 ** The register_pretty_printer function in module gdb.printing now takes
3007 an optional `replace' argument. If True, the new printer replaces any
3010 ** The "maint set python print-stack on|off" command has been
3011 deprecated and will be deleted in GDB 7.5.
3012 A new command: "set python print-stack none|full|message" has
3013 replaced it. Additionally, the default for "print-stack" is
3014 now "message", which just prints the error message without
3017 ** A prompt substitution hook (prompt_hook) is now available to the
3020 ** A new Python module, gdb.prompt has been added to the GDB Python
3021 modules library. This module provides functionality for
3022 escape sequences in prompts (used by set/show
3023 extended-prompt). These escape sequences are replaced by their
3024 corresponding value.
3026 ** Python commands and convenience-functions located in
3027 'data-directory'/python/gdb/command and
3028 'data-directory'/python/gdb/function are now automatically loaded
3031 ** Blocks now provide four new attributes. global_block and
3032 static_block will return the global and static blocks
3033 respectively. is_static and is_global are boolean attributes
3034 that indicate if the block is one of those two types.
3036 ** Symbols now provide the "type" attribute, the type of the symbol.
3038 ** The "gdb.breakpoint" function has been deprecated in favor of
3041 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3042 of a function. This class is based on the "finish" command
3043 available in the CLI.
3045 ** Type objects for struct and union types now allow access to
3046 the fields using standard Python dictionary (mapping) methods.
3047 For example, "some_type['myfield']" now works, as does
3048 "some_type.items()".
3050 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3053 ** A new function, "deep_items" has been added to the gdb.types
3054 module in the GDB Python modules library. This function returns
3055 an iterator over the fields of a struct or union type. Unlike
3056 the standard Python "iteritems" method, it will recursively traverse
3057 any anonymous fields.
3061 ** "*stopped" events can report several new "reason"s, such as
3064 ** Breakpoint changes are now notified using new async records, like
3065 "=breakpoint-modified".
3067 ** New command -ada-task-info.
3069 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3070 $sdir specifies the default system locations of shared libraries.
3071 $pdir specifies the directory where the libpthread used by the application
3074 GDB no longer looks in $sdir and $pdir after it has searched the directories
3075 mentioned in libthread-db-search-path. If you want to search those
3076 directories, they must be specified in libthread-db-search-path.
3077 The default value of libthread-db-search-path on GNU/Linux and Solaris
3078 systems is now "$sdir:$pdir".
3080 $pdir is not supported by gdbserver, it is currently ignored.
3081 $sdir is supported by gdbserver.
3083 * New configure option --with-iconv-bin.
3084 When using the internationalization support like the one in the GNU C
3085 library, GDB will invoke the "iconv" program to get a list of supported
3086 character sets. If this program lives in a non-standard location, one can
3087 use this option to specify where to find it.
3089 * When natively debugging programs on PowerPC BookE processors running
3090 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3091 watchpoints, which specify a mask in addition to an address to watch.
3092 The mask specifies that some bits of an address (the bits which are
3093 reset in the mask) should be ignored when matching the address accessed
3094 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3095 section in the user manual for more details.
3097 * The new option --once causes GDBserver to stop listening for connections once
3098 the first connection is made. The listening port used by GDBserver will
3099 become available after that.
3101 * New commands "info macros" and "alias" have been added.
3103 * New function parameters suffix @entry specifies value of function parameter
3104 at the time the function got called. Entry values are available only since
3110 "!" is now an alias of the "shell" command.
3111 Note that no space is needed between "!" and SHELL COMMAND.
3115 watch EXPRESSION mask MASK_VALUE
3116 The watch command now supports the mask argument which allows creation
3117 of masked watchpoints, if the current architecture supports this feature.
3119 info auto-load-scripts [REGEXP]
3120 This command was formerly named "maintenance print section-scripts".
3121 It is now generally useful and is no longer a maintenance-only command.
3123 info macro [-all] [--] MACRO
3124 The info macro command has new options `-all' and `--'. The first for
3125 printing all definitions of a macro. The second for explicitly specifying
3126 the end of arguments and the beginning of the macro name in case the macro
3127 name starts with a hyphen.
3129 collect[/s] EXPRESSIONS
3130 The tracepoint collect command now takes an optional modifier "/s"
3131 that directs it to dereference pointer-to-character types and
3132 collect the bytes of memory up to a zero byte. The behavior is
3133 similar to what you see when you use the regular print command on a
3134 string. An optional integer following the "/s" sets a bound on the
3135 number of bytes that will be collected.
3138 The trace start command now interprets any supplied arguments as a
3139 note to be recorded with the trace run, with an effect similar to
3140 setting the variable trace-notes.
3143 The trace stop command now interprets any arguments as a note to be
3144 mentioned along with the tstatus report that the trace was stopped
3145 with a command. The effect is similar to setting the variable
3148 * Tracepoints can now be enabled and disabled at any time after a trace
3149 experiment has been started using the standard "enable" and "disable"
3150 commands. It is now possible to start a trace experiment with no enabled
3151 tracepoints; GDB will display a warning, but will allow the experiment to
3152 begin, assuming that tracepoints will be enabled as needed while the trace
3155 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3156 locations with 4-byte instructions, when they were previously
3157 limited to locations with instructions of 5 bytes or longer.
3161 set debug dwarf2-read
3162 show debug dwarf2-read
3163 Turns on or off display of debugging messages related to reading
3164 DWARF debug info. The default is off.
3166 set debug symtab-create
3167 show debug symtab-create
3168 Turns on or off display of debugging messages related to symbol table
3169 creation. The default is off.
3172 show extended-prompt
3173 Set the GDB prompt, and allow escape sequences to be inserted to
3174 display miscellaneous information (see 'help set extended-prompt'
3175 for the list of sequences). This prompt (and any information
3176 accessed through the escape sequences) is updated every time the
3177 prompt is displayed.
3179 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3180 show print entry-values
3181 Set printing of frame argument values at function entry. In some cases
3182 GDB can determine the value of function argument which was passed by the
3183 function caller, even if the value was modified inside the called function.
3185 set debug entry-values
3186 show debug entry-values
3187 Control display of debugging info for determining frame argument values at
3188 function entry and virtual tail call frames.
3190 set basenames-may-differ
3191 show basenames-may-differ
3192 Set whether a source file may have multiple base names.
3193 (A "base name" is the name of a file with the directory part removed.
3194 Example: The base name of "/home/user/hello.c" is "hello.c".)
3195 If set, GDB will canonicalize file names (e.g., expand symlinks)
3196 before comparing them. Canonicalization is an expensive operation,
3197 but it allows the same file be known by more than one base name.
3198 If not set (the default), all source files are assumed to have just
3199 one base name, and gdb will do file name comparisons more efficiently.
3205 Set a user name and notes for the current and any future trace runs.
3206 This is useful for long-running and/or disconnected traces, to
3207 inform others (or yourself) as to who is running the trace, supply
3208 contact information, or otherwise explain what is going on.
3210 set trace-stop-notes
3211 show trace-stop-notes
3212 Set a note attached to the trace run, that is displayed when the
3213 trace has been stopped by a tstop command. This is useful for
3214 instance as an explanation, if you are stopping a trace run that was
3215 started by someone else.
3217 * New remote packets
3221 Dynamically enable a tracepoint in a started trace experiment.
3225 Dynamically disable a tracepoint in a started trace experiment.
3229 Set the user and notes of the trace run.
3233 Query the current status of a tracepoint.
3237 Query the minimum length of instruction at which a fast tracepoint may
3240 * Dcache size (number of lines) and line-size are now runtime-configurable
3241 via "set dcache line" and "set dcache line-size" commands.
3245 Texas Instruments TMS320C6x tic6x-*-*
3249 Renesas RL78 rl78-*-elf
3251 *** Changes in GDB 7.3.1
3253 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3255 *** Changes in GDB 7.3
3257 * GDB has a new command: "thread find [REGEXP]".
3258 It finds the thread id whose name, target id, or thread extra info
3259 matches the given regular expression.
3261 * The "catch syscall" command now works on mips*-linux* targets.
3263 * The -data-disassemble MI command now supports modes 2 and 3 for
3264 dumping the instruction opcodes.
3266 * New command line options
3268 -data-directory DIR Specify DIR as the "data-directory".
3269 This is mostly for testing purposes.
3271 * The "maint set python auto-load on|off" command has been renamed to
3272 "set auto-load-scripts on|off".
3274 * GDB has a new command: "set directories".
3275 It is like the "dir" command except that it replaces the
3276 source path list instead of augmenting it.
3278 * GDB now understands thread names.
3280 On GNU/Linux, "info threads" will display the thread name as set by
3281 prctl or pthread_setname_np.
3283 There is also a new command, "thread name", which can be used to
3284 assign a name internally for GDB to display.
3287 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3288 has been integrated into GDB.
3292 ** The function gdb.Write now accepts an optional keyword 'stream'.
3293 This keyword, when provided, will direct the output to either
3294 stdout, stderr, or GDB's logging output.
3296 ** Parameters can now be be sub-classed in Python, and in particular
3297 you may implement the get_set_doc and get_show_doc functions.
3298 This improves how Parameter set/show documentation is processed
3299 and allows for more dynamic content.
3301 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3302 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3303 have an is_valid method.
3305 ** Breakpoints can now be sub-classed in Python, and in particular
3306 you may implement a 'stop' function that is executed each time
3307 the inferior reaches that breakpoint.
3309 ** New function gdb.lookup_global_symbol looks up a global symbol.
3311 ** GDB values in Python are now callable if the value represents a
3312 function. For example, if 'some_value' represents a function that
3313 takes two integer parameters and returns a value, you can call
3314 that function like so:
3316 result = some_value (10,20)
3318 ** Module gdb.types has been added.
3319 It contains a collection of utilities for working with gdb.Types objects:
3320 get_basic_type, has_field, make_enum_dict.
3322 ** Module gdb.printing has been added.
3323 It contains utilities for writing and registering pretty-printers.
3324 New classes: PrettyPrinter, SubPrettyPrinter,
3325 RegexpCollectionPrettyPrinter.
3326 New function: register_pretty_printer.
3328 ** New commands "info pretty-printers", "enable pretty-printer" and
3329 "disable pretty-printer" have been added.
3331 ** gdb.parameter("directories") is now available.
3333 ** New function gdb.newest_frame returns the newest frame in the
3336 ** The gdb.InferiorThread class has a new "name" attribute. This
3337 holds the thread's name.
3339 ** Python Support for Inferior events.
3340 Python scripts can add observers to be notified of events
3341 occurring in the process being debugged.
3342 The following events are currently supported:
3343 - gdb.events.cont Continue event.
3344 - gdb.events.exited Inferior exited event.
3345 - gdb.events.stop Signal received, and Breakpoint hit events.
3349 ** GDB now puts template parameters in scope when debugging in an
3350 instantiation. For example, if you have:
3352 template<int X> int func (void) { return X; }
3354 then if you step into func<5>, "print X" will show "5". This
3355 feature requires proper debuginfo support from the compiler; it
3356 was added to GCC 4.5.
3358 ** The motion commands "next", "finish", "until", and "advance" now
3359 work better when exceptions are thrown. In particular, GDB will
3360 no longer lose control of the inferior; instead, the GDB will
3361 stop the inferior at the point at which the exception is caught.
3362 This functionality requires a change in the exception handling
3363 code that was introduced in GCC 4.5.
3365 * GDB now follows GCC's rules on accessing volatile objects when
3366 reading or writing target state during expression evaluation.
3367 One notable difference to prior behavior is that "print x = 0"
3368 no longer generates a read of x; the value of the assignment is
3369 now always taken directly from the value being assigned.
3371 * GDB now has some support for using labels in the program's source in
3372 linespecs. For instance, you can use "advance label" to continue
3373 execution to a label.
3375 * GDB now has support for reading and writing a new .gdb_index
3376 section. This section holds a fast index of DWARF debugging
3377 information and can be used to greatly speed up GDB startup and
3378 operation. See the documentation for `save gdb-index' for details.
3380 * The "watch" command now accepts an optional "-location" argument.
3381 When used, this causes GDB to watch the memory referred to by the
3382 expression. Such a watchpoint is never deleted due to it going out
3385 * GDB now supports thread debugging of core dumps on GNU/Linux.
3387 GDB now activates thread debugging using the libthread_db library
3388 when debugging GNU/Linux core dumps, similarly to when debugging
3389 live processes. As a result, when debugging a core dump file, GDB
3390 is now able to display pthread_t ids of threads. For example, "info
3391 threads" shows the same output as when debugging the process when it
3392 was live. In earlier releases, you'd see something like this:
3395 * 1 LWP 6780 main () at main.c:10
3397 While now you see this:
3400 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3402 It is also now possible to inspect TLS variables when debugging core
3405 When debugging a core dump generated on a machine other than the one
3406 used to run GDB, you may need to point GDB at the correct
3407 libthread_db library with the "set libthread-db-search-path"
3408 command. See the user manual for more details on this command.
3410 * When natively debugging programs on PowerPC BookE processors running
3411 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3412 which stop execution of the inferior whenever it executes an instruction
3413 at any address within the specified range. See the "PowerPC Embedded"
3414 section in the user manual for more details.
3416 * New features in the GDB remote stub, GDBserver
3418 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3419 and i686 LynxOS (version 5.x).
3421 ** GDBserver is now supported on Blackfin Linux.
3423 * New native configurations
3425 ia64 HP-UX ia64-*-hpux*
3429 Analog Devices, Inc. Blackfin Processor bfin-*
3431 * Ada task switching is now supported on sparc-elf targets when
3432 debugging a program using the Ravenscar Profile. For more information,
3433 see the "Tasking Support when using the Ravenscar Profile" section
3434 in the GDB user manual.
3436 * Guile support was removed.
3438 * New features in the GNU simulator
3440 ** The --map-info flag lists all known core mappings.
3442 ** CFI flashes may be simulated via the "cfi" device.
3444 *** Changes in GDB 7.2
3446 * Shared library support for remote targets by default
3448 When GDB is configured for a generic, non-OS specific target, like
3449 for example, --target=arm-eabi or one of the many *-*-elf targets,
3450 GDB now queries remote stubs for loaded shared libraries using the
3451 `qXfer:libraries:read' packet. Previously, shared library support
3452 was always disabled for such configurations.
3456 ** Argument Dependent Lookup (ADL)
3458 In C++ ADL lookup directs function search to the namespaces of its
3459 arguments even if the namespace has not been imported.
3469 Here the compiler will search for `foo' in the namespace of 'b'
3470 and find A::foo. GDB now supports this. This construct is commonly
3471 used in the Standard Template Library for operators.
3473 ** Improved User Defined Operator Support
3475 In addition to member operators, GDB now supports lookup of operators
3476 defined in a namespace and imported with a `using' directive, operators
3477 defined in the global scope, operators imported implicitly from an
3478 anonymous namespace, and the ADL operators mentioned in the previous
3480 GDB now also supports proper overload resolution for all the previously
3481 mentioned flavors of operators.
3483 ** static const class members
3485 Printing of static const class members that are initialized in the
3486 class definition has been fixed.
3488 * Windows Thread Information Block access.
3490 On Windows targets, GDB now supports displaying the Windows Thread
3491 Information Block (TIB) structure. This structure is visible either
3492 by using the new command `info w32 thread-information-block' or, by
3493 dereferencing the new convenience variable named `$_tlb', a
3494 thread-specific pointer to the TIB. This feature is also supported
3495 when remote debugging using GDBserver.
3497 * Static tracepoints
3499 Static tracepoints are calls in the user program into a tracing
3500 library. One such library is a port of the LTTng kernel tracer to
3501 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3502 When debugging with GDBserver, GDB now supports combining the GDB
3503 tracepoint machinery with such libraries. For example: the user can
3504 use GDB to probe a static tracepoint marker (a call from the user
3505 program into the tracing library) with the new "strace" command (see
3506 "New commands" below). This creates a "static tracepoint" in the
3507 breakpoint list, that can be manipulated with the same feature set
3508 as fast and regular tracepoints. E.g., collect registers, local and
3509 global variables, collect trace state variables, and define
3510 tracepoint conditions. In addition, the user can collect extra
3511 static tracepoint marker specific data, by collecting the new
3512 $_sdata internal variable. When analyzing the trace buffer, you can
3513 inspect $_sdata like any other variable available to GDB. For more
3514 information, see the "Tracepoints" chapter in GDB user manual. New
3515 remote packets have been defined to support static tracepoints, see
3516 the "New remote packets" section below.
3518 * Better reconstruction of tracepoints after disconnected tracing
3520 GDB will attempt to download the original source form of tracepoint
3521 definitions when starting a trace run, and then will upload these
3522 upon reconnection to the target, resulting in a more accurate
3523 reconstruction of the tracepoints that are in use on the target.
3527 You can now exercise direct control over the ways that GDB can
3528 affect your program. For instance, you can disallow the setting of
3529 breakpoints, so that the program can run continuously (assuming
3530 non-stop mode). In addition, the "observer" variable is available
3531 to switch all of the different controls; in observer mode, GDB
3532 cannot affect the target's behavior at all, which is useful for
3533 tasks like diagnosing live systems in the field.
3535 * The new convenience variable $_thread holds the number of the
3538 * New remote packets
3542 Return the address of the Windows Thread Information Block of a given thread.
3546 In response to several of the tracepoint packets, the target may now
3547 also respond with a number of intermediate `qRelocInsn' request
3548 packets before the final result packet, to have GDB handle
3549 relocating an instruction to execute at a different address. This
3550 is particularly useful for stubs that support fast tracepoints. GDB
3551 reports support for this feature in the qSupported packet.
3555 List static tracepoint markers in the target program.
3559 List static tracepoint markers at a given address in the target
3562 qXfer:statictrace:read
3564 Read the static trace data collected (by a `collect $_sdata'
3565 tracepoint action). The remote stub reports support for this packet
3566 to gdb's qSupported query.
3570 Send the current settings of GDB's permission flags.
3574 Send part of the source (textual) form of a tracepoint definition,
3575 which includes location, conditional, and action list.
3577 * The source command now accepts a -s option to force searching for the
3578 script in the source search path even if the script name specifies
3581 * New features in the GDB remote stub, GDBserver
3583 - GDBserver now support tracepoints (including fast tracepoints, and
3584 static tracepoints). The feature is currently supported by the
3585 i386-linux and amd64-linux builds. See the "Tracepoints support
3586 in gdbserver" section in the manual for more information.
3588 GDBserver JIT compiles the tracepoint's conditional agent
3589 expression bytecode into native code whenever possible for low
3590 overhead dynamic tracepoints conditionals. For such tracepoints,
3591 an expression that examines program state is evaluated when the
3592 tracepoint is reached, in order to determine whether to capture
3593 trace data. If the condition is simple and false, processing the
3594 tracepoint finishes very quickly and no data is gathered.
3596 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3597 for static tracepoints support.
3599 - GDBserver now supports x86_64 Windows 64-bit debugging.
3601 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3602 it understands register description.
3604 * The --batch flag now disables pagination and queries.
3606 * X86 general purpose registers
3608 GDB now supports reading/writing byte, word and double-word x86
3609 general purpose registers directly. This means you can use, say,
3610 $ah or $ax to refer, respectively, to the byte register AH and
3611 16-bit word register AX that are actually portions of the 32-bit
3612 register EAX or 64-bit register RAX.
3614 * The `commands' command now accepts a range of breakpoints to modify.
3615 A plain `commands' following a command that creates multiple
3616 breakpoints affects all the breakpoints set by that command. This
3617 applies to breakpoints set by `rbreak', and also applies when a
3618 single `break' command creates multiple breakpoints (e.g.,
3619 breakpoints on overloaded c++ functions).
3621 * The `rbreak' command now accepts a filename specification as part of
3622 its argument, limiting the functions selected by the regex to those
3623 in the specified file.
3625 * Support for remote debugging Windows and SymbianOS shared libraries
3626 from Unix hosts has been improved. Non Windows GDB builds now can
3627 understand target reported file names that follow MS-DOS based file
3628 system semantics, such as file names that include drive letters and
3629 use the backslash character as directory separator. This makes it
3630 possible to transparently use the "set sysroot" and "set
3631 solib-search-path" on Unix hosts to point as host copies of the
3632 target's shared libraries. See the new command "set
3633 target-file-system-kind" described below, and the "Commands to
3634 specify files" section in the user manual for more information.
3638 eval template, expressions...
3639 Convert the values of one or more expressions under the control
3640 of the string template to a command line, and call it.
3642 set target-file-system-kind unix|dos-based|auto
3643 show target-file-system-kind
3644 Set or show the assumed file system kind for target reported file
3647 save breakpoints <filename>
3648 Save all current breakpoint definitions to a file suitable for use
3649 in a later debugging session. To read the saved breakpoint
3650 definitions, use the `source' command.
3652 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3655 info static-tracepoint-markers
3656 Display information about static tracepoint markers in the target.
3658 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3659 Define a static tracepoint by probing a marker at the given
3660 function, line, address, or marker ID.
3664 Enable and disable observer mode.
3666 set may-write-registers on|off
3667 set may-write-memory on|off
3668 set may-insert-breakpoints on|off
3669 set may-insert-tracepoints on|off
3670 set may-insert-fast-tracepoints on|off
3671 set may-interrupt on|off
3672 Set individual permissions for GDB effects on the target. Note that
3673 some of these settings can have undesirable or surprising
3674 consequences, particularly when changed in the middle of a session.
3675 For instance, disabling the writing of memory can prevent
3676 breakpoints from being inserted, cause single-stepping to fail, or
3677 even crash your program, if you disable after breakpoints have been
3678 inserted. However, GDB should not crash.
3680 set record memory-query on|off
3681 show record memory-query
3682 Control whether to stop the inferior if memory changes caused
3683 by an instruction cannot be recorded.
3688 The disassemble command now supports "start,+length" form of two arguments.
3692 ** GDB now provides a new directory location, called the python directory,
3693 where Python scripts written for GDB can be installed. The location
3694 of that directory is <data-directory>/python, where <data-directory>
3695 is the GDB data directory. For more details, see section `Scripting
3696 GDB using Python' in the manual.
3698 ** The GDB Python API now has access to breakpoints, symbols, symbol
3699 tables, program spaces, inferiors, threads and frame's code blocks.
3700 Additionally, GDB Parameters can now be created from the API, and
3701 manipulated via set/show in the CLI.
3703 ** New functions gdb.target_charset, gdb.target_wide_charset,
3704 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3706 ** New exception gdb.GdbError.
3708 ** Pretty-printers are now also looked up in the current program space.
3710 ** Pretty-printers can now be individually enabled and disabled.
3712 ** GDB now looks for names of Python scripts to auto-load in a
3713 special section named `.debug_gdb_scripts', in addition to looking
3714 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3716 * Tracepoint actions were unified with breakpoint commands. In particular,
3717 there are no longer differences in "info break" output for breakpoints and
3718 tracepoints and the "commands" command can be used for both tracepoints and
3719 regular breakpoints.
3723 ARM Symbian arm*-*-symbianelf*
3725 * D language support.
3726 GDB now supports debugging programs written in the D programming
3729 * GDB now supports the extended ptrace interface for PowerPC which is
3730 available since Linux kernel version 2.6.34. This automatically enables
3731 any hardware breakpoints and additional hardware watchpoints available in
3732 the processor. The old ptrace interface exposes just one hardware
3733 watchpoint and no hardware breakpoints.
3735 * GDB is now able to use the Data Value Compare (DVC) register available on
3736 embedded PowerPC processors to implement in hardware simple watchpoint
3737 conditions of the form:
3739 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3741 This works in native GDB running on Linux kernels with the extended ptrace
3742 interface mentioned above.
3744 *** Changes in GDB 7.1
3748 ** Namespace Support
3750 GDB now supports importing of namespaces in C++. This enables the
3751 user to inspect variables from imported namespaces. Support for
3752 namepace aliasing has also been added. So, if a namespace is
3753 aliased in the current scope (e.g. namepace C=A; ) the user can
3754 print variables using the alias (e.g. (gdb) print C::x).
3758 All known bugs relating to the printing of virtual base class were
3759 fixed. It is now possible to call overloaded static methods using a
3764 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3765 and reinterpret_cast<> are now handled by the C++ expression parser.
3769 Xilinx MicroBlaze microblaze-*-*
3774 Xilinx MicroBlaze microblaze
3777 * Multi-program debugging.
3779 GDB now has support for multi-program (a.k.a. multi-executable or
3780 multi-exec) debugging. This allows for debugging multiple inferiors
3781 simultaneously each running a different program under the same GDB
3782 session. See "Debugging Multiple Inferiors and Programs" in the
3783 manual for more information. This implied some user visible changes
3784 in the multi-inferior support. For example, "info inferiors" now
3785 lists inferiors that are not running yet or that have exited
3786 already. See also "New commands" and "New options" below.
3788 * New tracing features
3790 GDB's tracepoint facility now includes several new features:
3792 ** Trace state variables
3794 GDB tracepoints now include support for trace state variables, which
3795 are variables managed by the target agent during a tracing
3796 experiment. They are useful for tracepoints that trigger each
3797 other, so for instance one tracepoint can count hits in a variable,
3798 and then a second tracepoint has a condition that is true when the
3799 count reaches a particular value. Trace state variables share the
3800 $-syntax of GDB convenience variables, and can appear in both
3801 tracepoint actions and condition expressions. Use the "tvariable"
3802 command to create, and "info tvariables" to view; see "Trace State
3803 Variables" in the manual for more detail.
3807 GDB now includes an option for defining fast tracepoints, which
3808 targets may implement more efficiently, such as by installing a jump
3809 into the target agent rather than a trap instruction. The resulting
3810 speedup can be by two orders of magnitude or more, although the
3811 tradeoff is that some program locations on some target architectures
3812 might not allow fast tracepoint installation, for instance if the
3813 instruction to be replaced is shorter than the jump. To request a
3814 fast tracepoint, use the "ftrace" command, with syntax identical to
3815 the regular trace command.
3817 ** Disconnected tracing
3819 It is now possible to detach GDB from the target while it is running
3820 a trace experiment, then reconnect later to see how the experiment
3821 is going. In addition, a new variable disconnected-tracing lets you
3822 tell the target agent whether to continue running a trace if the
3823 connection is lost unexpectedly.
3827 GDB now has the ability to save the trace buffer into a file, and
3828 then use that file as a target, similarly to you can do with
3829 corefiles. You can select trace frames, print data that was
3830 collected in them, and use tstatus to display the state of the
3831 tracing run at the moment that it was saved. To create a trace
3832 file, use "tsave <filename>", and to use it, do "target tfile
3835 ** Circular trace buffer
3837 You can ask the target agent to handle the trace buffer as a
3838 circular buffer, discarding the oldest trace frames to make room for
3839 newer ones, by setting circular-trace-buffer to on. This feature may
3840 not be available for all target agents.
3845 The disassemble command, when invoked with two arguments, now requires
3846 the arguments to be comma-separated.
3849 The info variables command now displays variable definitions. Files
3850 which only declare a variable are not shown.
3853 The source command is now capable of sourcing Python scripts.
3854 This feature is dependent on the debugger being build with Python
3857 Related to this enhancement is also the introduction of a new command
3858 "set script-extension" (see below).
3860 * New commands (for set/show, see "New options" below)
3862 record save [<FILENAME>]
3863 Save a file (in core file format) containing the process record
3864 execution log for replay debugging at a later time.
3866 record restore <FILENAME>
3867 Restore the process record execution log that was saved at an
3868 earlier time, for replay debugging.
3870 add-inferior [-copies <N>] [-exec <FILENAME>]
3873 clone-inferior [-copies <N>] [ID]
3874 Make a new inferior ready to execute the same program another
3875 inferior has loaded.
3880 maint info program-spaces
3881 List the program spaces loaded into GDB.
3883 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3884 show remote interrupt-sequence
3885 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3886 as the sequence to the remote target in order to interrupt the execution.
3887 Ctrl-C is a default. Some system prefers BREAK which is high level of
3888 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3889 Magic SysRq g. It is BREAK signal and character 'g'.
3891 set remote interrupt-on-connect [on | off]
3892 show remote interrupt-on-connect
3893 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3894 remote target when gdb connects to it. This is needed when you debug
3897 set remotebreak [on | off]
3899 Deprecated. Use "set/show remote interrupt-sequence" instead.
3901 tvariable $NAME [ = EXP ]
3902 Create or modify a trace state variable.
3905 List trace state variables and their values.
3907 delete tvariable $NAME ...
3908 Delete one or more trace state variables.
3911 Evaluate the given expressions without collecting anything into the
3912 trace buffer. (Valid in tracepoint actions only.)
3914 ftrace FN / FILE:LINE / *ADDR
3915 Define a fast tracepoint at the given function, line, or address.
3917 * New expression syntax
3919 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3920 GDB now parses 0b101010 identically with 42.
3924 set follow-exec-mode new|same
3925 show follow-exec-mode
3926 Control whether GDB reuses the same inferior across an exec call or
3927 creates a new one. This is useful to be able to restart the old
3928 executable after the inferior having done an exec call.
3930 set default-collect EXPR, ...
3931 show default-collect
3932 Define a list of expressions to be collected at each tracepoint.
3933 This is a useful way to ensure essential items are not overlooked,
3934 such as registers or a critical global variable.
3936 set disconnected-tracing
3937 show disconnected-tracing
3938 If set to 1, the target is instructed to continue tracing if it
3939 loses its connection to GDB. If 0, the target is to stop tracing
3942 set circular-trace-buffer
3943 show circular-trace-buffer
3944 If set to on, the target is instructed to use a circular trace buffer
3945 and discard the oldest trace frames instead of stopping the trace due
3946 to a full trace buffer. If set to off, the trace stops when the buffer
3947 fills up. Some targets may not support this.
3949 set script-extension off|soft|strict
3950 show script-extension
3951 If set to "off", the debugger does not perform any script language
3952 recognition, and all sourced files are assumed to be GDB scripts.
3953 If set to "soft" (the default), files are sourced according to
3954 filename extension, falling back to GDB scripts if the first
3956 If set to "strict", files are sourced according to filename extension.
3958 set ada trust-PAD-over-XVS on|off
3959 show ada trust-PAD-over-XVS
3960 If off, activate a workaround against a bug in the debugging information
3961 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3962 the GCC sources for more information about the GNAT encoding and
3963 PAD types in particular). It is always safe to set this option to
3964 off, but this introduces a slight performance penalty. The default
3967 * Python API Improvements
3969 ** GDB provides the new class gdb.LazyString. This is useful in
3970 some pretty-printing cases. The new method gdb.Value.lazy_string
3971 provides a simple way to create objects of this type.
3973 ** The fields returned by gdb.Type.fields now have an
3974 `is_base_class' attribute.
3976 ** The new method gdb.Type.range returns the range of an array type.
3978 ** The new method gdb.parse_and_eval can be used to parse and
3979 evaluate an expression.
3981 * New remote packets
3984 Define a trace state variable.
3987 Get the current value of a trace state variable.
3990 Set desired tracing behavior upon disconnection.
3993 Set the trace buffer to be linear or circular.
3996 Get data about the tracepoints currently in use.
4000 Process record now works correctly with hardware watchpoints.
4002 Multiple bug fixes have been made to the mips-irix port, making it
4003 much more reliable. In particular:
4004 - Debugging threaded applications is now possible again. Previously,
4005 GDB would hang while starting the program, or while waiting for
4006 the program to stop at a breakpoint.
4007 - Attaching to a running process no longer hangs.
4008 - An error occurring while loading a core file has been fixed.
4009 - Changing the value of the PC register now works again. This fixes
4010 problems observed when using the "jump" command, or when calling
4011 a function from GDB, or even when assigning a new value to $pc.
4012 - With the "finish" and "return" commands, the return value for functions
4013 returning a small array is now correctly printed.
4014 - It is now possible to break on shared library code which gets executed
4015 during a shared library init phase (code executed while executing
4016 their .init section). Previously, the breakpoint would have no effect.
4017 - GDB is now able to backtrace through the signal handler for
4018 non-threaded programs.
4020 PIE (Position Independent Executable) programs debugging is now supported.
4021 This includes debugging execution of PIC (Position Independent Code) shared
4022 libraries although for that, it should be possible to run such libraries as an
4025 *** Changes in GDB 7.0
4027 * GDB now has an interface for JIT compilation. Applications that
4028 dynamically generate code can create symbol files in memory and register
4029 them with GDB. For users, the feature should work transparently, and
4030 for JIT developers, the interface is documented in the GDB manual in the
4031 "JIT Compilation Interface" chapter.
4033 * Tracepoints may now be conditional. The syntax is as for
4034 breakpoints; either an "if" clause appended to the "trace" command,
4035 or the "condition" command is available. GDB sends the condition to
4036 the target for evaluation using the same bytecode format as is used
4037 for tracepoint actions.
4039 * The disassemble command now supports: an optional /r modifier, print the
4040 raw instructions in hex as well as in symbolic form, and an optional /m
4041 modifier to print mixed source+assembly.
4043 * Process record and replay
4045 In a architecture environment that supports ``process record and
4046 replay'', ``process record and replay'' target can record a log of
4047 the process execution, and replay it with both forward and reverse
4050 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4051 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4052 set execution-direction {forward|reverse}, for targets that support
4055 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4056 feature is available with a native GDB running on kernel version
4059 * GDB now has support for multi-byte and wide character sets on the
4060 target. Strings whose character type is wchar_t, char16_t, or
4061 char32_t are now correctly printed. GDB supports wide- and unicode-
4062 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4063 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4064 `printf'. This feature requires iconv to work properly; if your
4065 system does not have a working iconv, GDB can use GNU libiconv. See
4066 the installation instructions for more information.
4068 * GDB now supports automatic retrieval of shared library files from
4069 remote targets. To use this feature, specify a system root that begins
4070 with the `remote:' prefix, either via the `set sysroot' command or via
4071 the `--with-sysroot' configure-time option.
4073 * "info sharedlibrary" now takes an optional regex of libraries to show,
4074 and it now reports if a shared library has no debugging information.
4076 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4077 now complete on file names.
4079 * When completing in expressions, gdb will attempt to limit
4080 completions to allowable structure or union fields, where appropriate.
4081 For instance, consider:
4083 # struct example { int f1; double f2; };
4084 # struct example variable;
4087 If the user types TAB at the end of this command line, the available
4088 completions will be "f1" and "f2".
4090 * Inlined functions are now supported. They show up in backtraces, and
4091 the "step", "next", and "finish" commands handle them automatically.
4093 * GDB now supports the token-splicing (##) and stringification (#)
4094 operators when expanding macros. It also supports variable-arity
4097 * GDB now supports inspecting extra signal information, exported by
4098 the new $_siginfo convenience variable. The feature is currently
4099 implemented on linux ARM, i386 and amd64.
4101 * GDB can now display the VFP floating point registers and NEON vector
4102 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4103 can provide these registers (requires Linux 2.6.30 or later). Remote
4104 and simulator targets may also provide them.
4106 * New remote packets
4109 Search memory for a sequence of bytes.
4112 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4113 operation over reliable transport links. Use of this packet is
4114 controlled by the `set remote noack-packet' command.
4117 Kill the process with the specified process ID. Use this in preference
4118 to `k' when multiprocess protocol extensions are supported.
4121 Obtains additional operating system information
4125 Read or write additional signal information.
4127 * Removed remote protocol undocumented extension
4129 An undocumented extension to the remote protocol's `S' stop reply
4130 packet that permited the stub to pass a process id was removed.
4131 Remote servers should use the `T' stop reply packet instead.
4133 * GDB now supports multiple function calling conventions according to the
4134 DWARF-2 DW_AT_calling_convention function attribute.
4136 * The SH target utilizes the aforementioned change to distinguish between gcc
4137 and Renesas calling convention. It also adds the new CLI commands
4138 `set/show sh calling-convention'.
4140 * GDB can now read compressed debug sections, as produced by GNU gold
4141 with the --compress-debug-sections=zlib flag.
4143 * 64-bit core files are now supported on AIX.
4145 * Thread switching is now supported on Tru64.
4147 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4148 which will be allocated using malloc later in program execution.
4150 * The qXfer:libraries:read remote procotol packet now allows passing a
4151 list of section offsets.
4153 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4154 conditions handling signals delivered during attach or thread creation
4155 have also been fixed.
4157 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4158 From the user's standpoint, all unqualified instances of True and False
4159 are treated as the standard definitions, regardless of context.
4161 * GDB now parses C++ symbol and type names more flexibly. For
4164 template<typename T> class C { };
4167 GDB will now correctly handle all of:
4169 ptype C<char const *>
4170 ptype C<char const*>
4171 ptype C<const char *>
4172 ptype C<const char*>
4174 * New features in the GDB remote stub, gdbserver
4176 - The "--wrapper" command-line argument tells gdbserver to use a
4177 wrapper program to launch programs for debugging.
4179 - On PowerPC and S/390 targets, it is now possible to use a single
4180 gdbserver executable to debug both 32-bit and 64-bit programs.
4181 (This requires gdbserver itself to be built as a 64-bit executable.)
4183 - gdbserver uses the new noack protocol mode for TCP connections to
4184 reduce communications latency, if also supported and enabled in GDB.
4186 - Support for the sparc64-linux-gnu target is now included in
4189 - The amd64-linux build of gdbserver now supports debugging both
4190 32-bit and 64-bit programs.
4192 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4193 now support hardware watchpoints, and will use them automatically
4198 GDB now has support for scripting using Python. Whether this is
4199 available is determined at configure time.
4201 New GDB commands can now be written in Python.
4203 * Ada tasking support
4205 Ada tasks can now be inspected in GDB. The following commands have
4209 Print the list of Ada tasks.
4211 Print detailed information about task number N.
4213 Print the task number of the current task.
4215 Switch the context of debugging to task number N.
4217 * Support for user-defined prefixed commands. The "define" command can
4218 add new commands to existing prefixes, e.g. "target".
4220 * Multi-inferior, multi-process debugging.
4222 GDB now has generalized support for multi-inferior debugging. See
4223 "Debugging Multiple Inferiors" in the manual for more information.
4224 Although availability still depends on target support, the command
4225 set is more uniform now. The GNU/Linux specific multi-forks support
4226 has been migrated to this new framework. This implied some user
4227 visible changes; see "New commands" and also "Removed commands"
4230 * Target descriptions can now describe the target OS ABI. See the
4231 "Target Description Format" section in the user manual for more
4234 * Target descriptions can now describe "compatible" architectures
4235 to indicate that the target can execute applications for a different
4236 architecture in addition to those for the main target architecture.
4237 See the "Target Description Format" section in the user manual for
4240 * Multi-architecture debugging.
4242 GDB now includes general supports for debugging applications on
4243 hybrid systems that use more than one single processor architecture
4244 at the same time. Each such hybrid architecture still requires
4245 specific support to be added. The only hybrid architecture supported
4246 in this version of GDB is the Cell Broadband Engine.
4248 * GDB now supports integrated debugging of Cell/B.E. applications that
4249 use both the PPU and SPU architectures. To enable support for hybrid
4250 Cell/B.E. debugging, you need to configure GDB to support both the
4251 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4252 --enable-targets configure option.
4254 * Non-stop mode debugging.
4256 For some targets, GDB now supports an optional mode of operation in
4257 which you can examine stopped threads while other threads continue
4258 to execute freely. This is referred to as non-stop mode, with the
4259 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4260 section in the user manual for more information.
4262 To be able to support remote non-stop debugging, a remote stub needs
4263 to implement the non-stop mode remote protocol extensions, as
4264 described in the "Remote Non-Stop" section of the user manual. The
4265 GDB remote stub, gdbserver, has been adjusted to support these
4266 extensions on linux targets.
4268 * New commands (for set/show, see "New options" below)
4270 catch syscall [NAME(S) | NUMBER(S)]
4271 Catch system calls. Arguments, which should be names of system
4272 calls or their numbers, mean catch only those syscalls. Without
4273 arguments, every syscall will be caught. When the inferior issues
4274 any of the specified syscalls, GDB will stop and announce the system
4275 call, both when it is called and when its call returns. This
4276 feature is currently available with a native GDB running on the
4277 Linux Kernel, under the following architectures: x86, x86_64,
4278 PowerPC and PowerPC64.
4280 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4282 Search memory for a sequence of bytes.
4284 maint set python print-stack
4285 maint show python print-stack
4286 Show a stack trace when an error is encountered in a Python script.
4289 Invoke CODE by passing it to the Python interpreter.
4294 These allow macros to be defined, undefined, and listed
4298 Show operating system information about processes.
4301 List the inferiors currently under GDB's control.
4304 Switch focus to inferior number NUM.
4307 Detach from inferior number NUM.
4310 Kill inferior number NUM.
4314 set spu stop-on-load
4315 show spu stop-on-load
4316 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4318 set spu auto-flush-cache
4319 show spu auto-flush-cache
4320 Control whether to automatically flush the software-managed cache
4321 during Cell/B.E. debugging.
4323 set sh calling-convention
4324 show sh calling-convention
4325 Control the calling convention used when calling SH target functions.
4328 show debug timestamp
4329 Control display of timestamps with GDB debugging output.
4331 set disassemble-next-line
4332 show disassemble-next-line
4333 Control display of disassembled source lines or instructions when
4336 set remote noack-packet
4337 show remote noack-packet
4338 Set/show the use of remote protocol QStartNoAckMode packet. See above
4339 under "New remote packets."
4341 set remote query-attached-packet
4342 show remote query-attached-packet
4343 Control use of remote protocol `qAttached' (query-attached) packet.
4345 set remote read-siginfo-object
4346 show remote read-siginfo-object
4347 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4350 set remote write-siginfo-object
4351 show remote write-siginfo-object
4352 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4355 set remote reverse-continue
4356 show remote reverse-continue
4357 Control use of remote protocol 'bc' (reverse-continue) packet.
4359 set remote reverse-step
4360 show remote reverse-step
4361 Control use of remote protocol 'bs' (reverse-step) packet.
4363 set displaced-stepping
4364 show displaced-stepping
4365 Control displaced stepping mode. Displaced stepping is a way to
4366 single-step over breakpoints without removing them from the debuggee.
4367 Also known as "out-of-line single-stepping".
4370 show debug displaced
4371 Control display of debugging info for displaced stepping.
4373 maint set internal-error
4374 maint show internal-error
4375 Control what GDB does when an internal error is detected.
4377 maint set internal-warning
4378 maint show internal-warning
4379 Control what GDB does when an internal warning is detected.
4384 Use a wrapper program to launch programs for debugging.
4386 set multiple-symbols (all|ask|cancel)
4387 show multiple-symbols
4388 The value of this variable can be changed to adjust the debugger behavior
4389 when an expression or a breakpoint location contains an ambiguous symbol
4390 name (an overloaded function name, for instance).
4392 set breakpoint always-inserted
4393 show breakpoint always-inserted
4394 Keep breakpoints always inserted in the target, as opposed to inserting
4395 them when resuming the target, and removing them when the target stops.
4396 This option can improve debugger performance on slow remote targets.
4398 set arm fallback-mode (arm|thumb|auto)
4399 show arm fallback-mode
4400 set arm force-mode (arm|thumb|auto)
4402 These commands control how ARM GDB determines whether instructions
4403 are ARM or Thumb. The default for both settings is auto, which uses
4404 the current CPSR value for instructions without symbols; previous
4405 versions of GDB behaved as if "set arm fallback-mode arm".
4407 set disable-randomization
4408 show disable-randomization
4409 Standalone programs run with the virtual address space randomization enabled
4410 by default on some platforms. This option keeps the addresses stable across
4411 multiple debugging sessions.
4415 Control whether other threads are stopped or not when some thread hits
4420 Requests that asynchronous execution is enabled in the target, if available.
4421 In this case, it's possible to resume target in the background, and interact
4422 with GDB while the target is running. "show target-async" displays the
4423 current state of asynchronous execution of the target.
4425 set target-wide-charset
4426 show target-wide-charset
4427 The target-wide-charset is the name of the character set that GDB
4428 uses when printing characters whose type is wchar_t.
4430 set tcp auto-retry (on|off)
4432 set tcp connect-timeout
4433 show tcp connect-timeout
4434 These commands allow GDB to retry failed TCP connections to a remote stub
4435 with a specified timeout period; this is useful if the stub is launched
4436 in parallel with GDB but may not be ready to accept connections immediately.
4438 set libthread-db-search-path
4439 show libthread-db-search-path
4440 Control list of directories which GDB will search for appropriate
4443 set schedule-multiple (on|off)
4444 show schedule-multiple
4445 Allow GDB to resume all threads of all processes or only threads of
4446 the current process.
4450 Use more aggressive caching for accesses to the stack. This improves
4451 performance of remote debugging (particularly backtraces) without
4452 affecting correctness.
4454 set interactive-mode (on|off|auto)
4455 show interactive-mode
4456 Control whether GDB runs in interactive mode (on) or not (off).
4457 When in interactive mode, GDB waits for the user to answer all
4458 queries. Otherwise, GDB does not wait and assumes the default
4459 answer. When set to auto (the default), GDB determines which
4460 mode to use based on the stdin settings.
4465 For program forks, this is replaced by the new more generic `info
4466 inferiors' command. To list checkpoints, you can still use the
4467 `info checkpoints' command, which was an alias for the `info forks'
4471 Replaced by the new `inferior' command. To switch between
4472 checkpoints, you can still use the `restart' command, which was an
4473 alias for the `fork' command.
4476 This is removed, since some targets don't have a notion of
4477 processes. To switch between processes, you can still use the
4478 `inferior' command using GDB's own inferior number.
4481 For program forks, this is replaced by the new more generic `kill
4482 inferior' command. To delete a checkpoint, you can still use the
4483 `delete checkpoint' command, which was an alias for the `delete
4487 For program forks, this is replaced by the new more generic `detach
4488 inferior' command. To detach a checkpoint, you can still use the
4489 `detach checkpoint' command, which was an alias for the `detach
4492 * New native configurations
4494 x86/x86_64 Darwin i[34567]86-*-darwin*
4496 x86_64 MinGW x86_64-*-mingw*
4500 Lattice Mico32 lm32-*
4501 x86 DICOS i[34567]86-*-dicos*
4502 x86_64 DICOS x86_64-*-dicos*
4505 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4506 (mingw32ce) debugging.
4512 These commands were actually not implemented on any target.
4514 *** Changes in GDB 6.8
4516 * New native configurations
4518 NetBSD/hppa hppa*-*netbsd*
4519 Xtensa GNU/Linux xtensa*-*-linux*
4523 NetBSD/hppa hppa*-*-netbsd*
4524 Xtensa GNU/Lunux xtensa*-*-linux*
4526 * Change in command line behavior -- corefiles vs. process ids.
4528 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4529 attaching to process NUMBER fails, GDB no longer attempts to open a
4530 core file named NUMBER. Attaching to a program using the -c option
4531 is no longer supported. Instead, use the '-p' or '--pid' options.
4533 * GDB can now be built as a native debugger for debugging Windows x86
4534 (mingw32) Portable Executable (PE) programs.
4536 * Pending breakpoints no longer change their number when their address
4539 * GDB now supports breakpoints with multiple locations,
4540 including breakpoints on C++ constructors, inside C++ templates,
4541 and in inlined functions.
4543 * GDB's ability to debug optimized code has been improved. GDB more
4544 accurately identifies function bodies and lexical blocks that occupy
4545 more than one contiguous range of addresses.
4547 * Target descriptions can now describe registers for PowerPC.
4549 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4550 registers on PowerPC targets.
4552 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4553 targets even when the libthread_db library is not available.
4555 * The GDB remote stub, gdbserver, now supports the new file transfer
4556 commands (remote put, remote get, and remote delete).
4558 * The GDB remote stub, gdbserver, now supports run and attach in
4559 extended-remote mode.
4561 * hppa*64*-*-hpux11* target broken
4562 The debugger is unable to start a program and fails with the following
4563 error: "Error trying to get information about dynamic linker".
4564 The gdb-6.7 release is also affected.
4566 * GDB now supports the --enable-targets= configure option to allow
4567 building a single GDB executable that supports multiple remote
4568 target architectures.
4570 * GDB now supports debugging C and C++ programs which use the
4571 Decimal Floating Point extension. In addition, the PowerPC target
4572 now has a set of pseudo-registers to inspect decimal float values
4573 stored in two consecutive float registers.
4575 * The -break-insert MI command can optionally create pending
4578 * Improved support for debugging Ada
4579 Many improvements to the Ada language support have been made. These
4581 - Better support for Ada2005 interface types
4582 - Improved handling of arrays and slices in general
4583 - Better support for Taft-amendment types
4584 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4586 - Improved command completion in Ada
4589 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4594 set print frame-arguments (all|scalars|none)
4595 show print frame-arguments
4596 The value of this variable can be changed to control which argument
4597 values should be printed by the debugger when displaying a frame.
4602 Transfer files to and from a remote target, and delete remote files.
4609 Transfer files to and from a remote target, and delete remote files.
4611 * New remote packets
4618 Open, close, read, write, and delete files on the remote system.
4621 Attach to an existing process on the remote system, in extended-remote
4625 Run a new process on the remote system, in extended-remote mode.
4627 *** Changes in GDB 6.7
4629 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4630 bfd, libiberty and opcodes, as revealed by static analysis donated by
4631 Coverity, Inc. (http://scan.coverity.com).
4633 * When looking up multiply-defined global symbols, GDB will now prefer the
4634 symbol definition in the current shared library if it was built using the
4635 -Bsymbolic linker option.
4637 * When the Text User Interface (TUI) is not configured, GDB will now
4638 recognize the -tui command-line option and print a message that the TUI
4641 * The GDB remote stub, gdbserver, now has lower overhead for high
4642 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4644 * GDB for MIPS targets now autodetects whether a remote target provides
4645 32-bit or 64-bit register values.
4647 * Support for C++ member pointers has been improved.
4649 * GDB now understands XML target descriptions, which specify the
4650 target's overall architecture. GDB can read a description from
4651 a local file or over the remote serial protocol.
4653 * Vectors of single-byte data use a new integer type which is not
4654 automatically displayed as character or string data.
4656 * The /s format now works with the print command. It displays
4657 arrays of single-byte integers and pointers to single-byte integers
4660 * Target descriptions can now describe target-specific registers,
4661 for architectures which have implemented the support (currently
4662 only ARM, M68K, and MIPS).
4664 * GDB and the GDB remote stub, gdbserver, now support the XScale
4667 * The GDB remote stub, gdbserver, has been updated to support
4668 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4669 has been rewritten to use the standard GDB remote protocol.
4671 * GDB can now step into C++ functions which are called through thunks.
4673 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4675 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4676 layout. It also supports a TextSeg= and DataSeg= response when only
4677 segment base addresses (rather than offsets) are available.
4679 * The /i format now outputs any trailing branch delay slot instructions
4680 immediately following the last instruction within the count specified.
4682 * The GDB remote protocol "T" stop reply packet now supports a
4683 "library" response. Combined with the new "qXfer:libraries:read"
4684 packet, this response allows GDB to debug shared libraries on targets
4685 where the operating system manages the list of loaded libraries (e.g.
4686 Windows and SymbianOS).
4688 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4689 (DLLs) on Windows and Windows CE targets.
4691 * GDB now supports a faster verification that a .debug file matches its binary
4692 according to its build-id signature, if the signature is present.
4698 Enable or disable hardware flow control (RTS/CTS) on the serial port
4699 when debugging using remote targets.
4701 set mem inaccessible-by-default
4702 show mem inaccessible-by-default
4703 If the target supplies a memory map, for instance via the remote
4704 protocol's "qXfer:memory-map:read" packet, setting this variable
4705 prevents GDB from accessing memory outside the memory map. This
4706 is useful for targets with memory mapped registers or which react
4707 badly to accesses of unmapped address space.
4709 set breakpoint auto-hw
4710 show breakpoint auto-hw
4711 If the target supplies a memory map, for instance via the remote
4712 protocol's "qXfer:memory-map:read" packet, setting this variable
4713 lets GDB use hardware breakpoints automatically for memory regions
4714 where it can not use software breakpoints. This covers both the
4715 "break" command and internal breakpoints used for other commands
4716 including "next" and "finish".
4719 catch exception unhandled
4720 Stop the program execution when Ada exceptions are raised.
4723 Stop the program execution when an Ada assertion failed.
4727 Set an alternate system root for target files. This is a more
4728 general version of "set solib-absolute-prefix", which is now
4729 an alias to "set sysroot".
4732 Provide extended SPU facility status information. This set of
4733 commands is available only when debugging the Cell/B.E. SPU
4736 * New native configurations
4738 OpenBSD/sh sh*-*openbsd*
4741 unset tdesc filename
4743 Use the specified local file as an XML target description, and do
4744 not query the target for its built-in description.
4748 OpenBSD/sh sh*-*-openbsd*
4749 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4750 Toshiba Media Processor mep-elf
4752 * New remote packets
4755 Ignore the specified signals; pass them directly to the debugged program
4756 without stopping other threads or reporting them to GDB.
4758 qXfer:features:read:
4759 Read an XML target description from the target, which describes its
4764 Read or write contents of an spufs file on the target system. These
4765 packets are available only on the Cell/B.E. SPU architecture.
4767 qXfer:libraries:read:
4768 Report the loaded shared libraries. Combined with new "T" packet
4769 response, this packet allows GDB to debug shared libraries on
4770 targets where the operating system manages the list of loaded
4771 libraries (e.g. Windows and SymbianOS).
4775 Support for these obsolete configurations has been removed.
4783 i[34567]86-*-lynxos*
4784 i[34567]86-*-netware*
4785 i[34567]86-*-sco3.2v5*
4786 i[34567]86-*-sco3.2v4*
4788 i[34567]86-*-sysv4.2*
4791 i[34567]86-*-unixware2*
4792 i[34567]86-*-unixware*
4801 * Other removed features
4808 Various m68k-only ROM monitors.
4815 Various Renesas ROM monitors and debugging interfaces for SH and
4820 Support for a Macraigor serial interface to on-chip debugging.
4821 GDB does not directly support the newer parallel or USB
4826 A debug information format. The predecessor to DWARF 2 and
4827 DWARF 3, which are still supported.
4829 Support for the HP aCC compiler on HP-UX/PA-RISC
4831 SOM-encapsulated symbolic debugging information, automatic
4832 invocation of pxdb, and the aCC custom C++ ABI. This does not
4833 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4834 with aCC can still be debugged on an assembly level.
4836 MIPS ".pdr" sections
4838 A MIPS-specific format used to describe stack frame layout
4839 in debugging information.
4843 GDB could work with an older version of Guile to debug
4844 the interpreter and Scheme programs running in it.
4846 set mips stack-arg-size
4847 set mips saved-gpreg-size
4849 Use "set mips abi" to control parameter passing for MIPS.
4851 *** Changes in GDB 6.6
4856 Cell Broadband Engine SPU spu-elf
4858 * GDB can now be configured as a cross-debugger targeting native Windows
4859 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4860 running on a Windows system over TCP/IP to debug Windows programs.
4862 * The GDB remote stub, gdbserver, has been updated to support Windows and
4863 Cygwin debugging. Both single-threaded and multi-threaded programs are
4866 * The "set trust-readonly-sections" command works again. This command was
4867 broken in GDB 6.3, 6.4, and 6.5.
4869 * The "load" command now supports writing to flash memory, if the remote
4870 stub provides the required support.
4872 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4873 longer requires symbolic debug information (e.g. DWARF-2).
4878 unset substitute-path
4879 show substitute-path
4880 Manage a list of substitution rules that GDB uses to rewrite the name
4881 of the directories where the sources are located. This can be useful
4882 for instance when the sources were moved to a different location
4883 between compilation and debugging.
4887 Print each CLI command as it is executed. Each command is prefixed with
4888 a number of `+' symbols representing the nesting depth.
4889 The source command now has a `-v' option to enable the same feature.
4893 The ARM Demon monitor support (RDP protocol, "target rdp").
4895 Kernel Object Display, an embedded debugging feature which only worked with
4896 an obsolete version of Cisco IOS.
4898 The 'set download-write-size' and 'show download-write-size' commands.
4900 * New remote packets
4903 Tell a stub about GDB client features, and request remote target features.
4904 The first feature implemented is PacketSize, which allows the target to
4905 specify the size of packets it can handle - to minimize the number of
4906 packets required and improve performance when connected to a remote
4910 Fetch an OS auxilliary vector from the remote stub. This packet is a
4911 more efficient replacement for qPart:auxv:read.
4913 qXfer:memory-map:read:
4914 Fetch a memory map from the remote stub, including information about
4915 RAM, ROM, and flash memory devices.
4920 Erase and program a flash memory device.
4922 * Removed remote packets
4925 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4926 used it, and only gdbserver implemented it.
4928 *** Changes in GDB 6.5
4932 Renesas M32C/M16C m32c-elf
4934 Morpho Technologies ms1 ms1-elf
4938 init-if-undefined Initialize a convenience variable, but
4939 only if it doesn't already have a value.
4941 The following commands are presently only implemented for native GNU/Linux:
4943 checkpoint Save a snapshot of the program state.
4945 restart <n> Return the program state to a
4946 previously saved state.
4948 info checkpoints List currently saved checkpoints.
4950 delete-checkpoint <n> Delete a previously saved checkpoint.
4952 set|show detach-on-fork Tell gdb whether to detach from a newly
4953 forked process, or to keep debugging it.
4955 info forks List forks of the user program that
4956 are available to be debugged.
4958 fork <n> Switch to debugging one of several
4959 forks of the user program that are
4960 available to be debugged.
4962 delete-fork <n> Delete a fork from the list of forks
4963 that are available to be debugged (and
4964 kill the forked process).
4966 detach-fork <n> Delete a fork from the list of forks
4967 that are available to be debugged (and
4968 allow the process to continue).
4972 Morpho Technologies ms2 ms1-elf
4974 * Improved Windows host support
4976 GDB now builds as a cross debugger hosted on i686-mingw32, including
4977 native console support, and remote communications using either
4978 network sockets or serial ports.
4980 * Improved Modula-2 language support
4982 GDB can now print most types in the Modula-2 syntax. This includes:
4983 basic types, set types, record types, enumerated types, range types,
4984 pointer types and ARRAY types. Procedure var parameters are correctly
4985 printed and hexadecimal addresses and character constants are also
4986 written in the Modula-2 syntax. Best results can be obtained by using
4987 GNU Modula-2 together with the -gdwarf-2 command line option.
4991 The ARM rdi-share module.
4993 The Netware NLM debug server.
4995 *** Changes in GDB 6.4
4997 * New native configurations
4999 OpenBSD/arm arm*-*-openbsd*
5000 OpenBSD/mips64 mips64-*-openbsd*
5004 Morpho Technologies ms1 ms1-elf
5006 * New command line options
5008 --batch-silent As for --batch, but totally silent.
5009 --return-child-result The debugger will exist with the same value
5010 the child (debugged) program exited with.
5011 --eval-command COMMAND, -ex COMMAND
5012 Execute a single GDB CLI command. This may be
5013 specified multiple times and in conjunction
5014 with the --command (-x) option.
5016 * Deprecated commands removed
5018 The following commands, that were deprecated in 2000, have been
5022 set|show arm disassembly-flavor set|show arm disassembler
5023 othernames set arm disassembler
5024 set|show remotedebug set|show debug remote
5025 set|show archdebug set|show debug arch
5026 set|show eventdebug set|show debug event
5029 * New BSD user-level threads support
5031 It is now possible to debug programs using the user-level threads
5032 library on OpenBSD and FreeBSD. Currently supported (target)
5035 FreeBSD/amd64 x86_64-*-freebsd*
5036 FreeBSD/i386 i386-*-freebsd*
5037 OpenBSD/i386 i386-*-openbsd*
5039 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5040 are not yet supported.
5042 * New support for Matsushita MN10300 w/sim added
5043 (Work in progress). mn10300-elf.
5045 * REMOVED configurations and files
5047 VxWorks and the XDR protocol *-*-vxworks
5048 Motorola MCORE mcore-*-*
5049 National Semiconductor NS32000 ns32k-*-*
5051 * New "set print array-indexes" command
5053 After turning this setting "on", GDB prints the index of each element
5054 when displaying arrays. The default is "off" to preserve the previous
5057 * VAX floating point support
5059 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5061 * User-defined command support
5063 In addition to using $arg0..$arg9 for argument passing, it is now possible
5064 to use $argc to determine now many arguments have been passed. See the
5065 section on user-defined commands in the user manual for more information.
5067 *** Changes in GDB 6.3:
5069 * New command line option
5071 GDB now accepts -l followed by a number to set the timeout for remote
5074 * GDB works with GCC -feliminate-dwarf2-dups
5076 GDB now supports a more compact representation of DWARF-2 debug
5077 information using DW_FORM_ref_addr references. These are produced
5078 by GCC with the option -feliminate-dwarf2-dups and also by some
5079 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5080 to use -feliminate-dwarf2-dups.
5082 * Internationalization
5084 When supported by the host system, GDB will be built with
5085 internationalization (libintl). The task of marking up the sources is
5086 continued, we're looking forward to our first translation.
5090 Initial support for debugging programs compiled with the GNAT
5091 implementation of the Ada programming language has been integrated
5092 into GDB. In this release, support is limited to expression evaluation.
5094 * New native configurations
5096 GNU/Linux/m32r m32r-*-linux-gnu
5100 GDB's remote protocol now includes support for the 'p' packet. This
5101 packet is used to fetch individual registers from a remote inferior.
5103 * END-OF-LIFE registers[] compatibility module
5105 GDB's internal register infrastructure has been completely rewritten.
5106 The new infrastructure making possible the implementation of key new
5107 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5110 GDB 6.3 will be the last release to include the the registers[]
5111 compatibility module that allowed out-of-date configurations to
5112 continue to work. This change directly impacts the following
5122 powerpc bdm protocol
5124 Unless there is activity to revive these configurations, they will be
5125 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5127 * OBSOLETE configurations and files
5129 Configurations that have been declared obsolete in this release have
5130 been commented out. Unless there is activity to revive these
5131 configurations, the next release of GDB will have their sources
5132 permanently REMOVED.
5141 *** Changes in GDB 6.2.1:
5143 * MIPS `break main; run' gave an heuristic-fence-post warning
5145 When attempting to run even a simple program, a warning about
5146 heuristic-fence-post being hit would be reported. This problem has
5149 * MIPS IRIX 'long double' crashed GDB
5151 When examining a long double variable, GDB would get a segmentation
5152 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5153 IRIX long double values).
5157 A bug in the VAX stack code was causing problems with the "next"
5158 command. This problem has been fixed.
5160 *** Changes in GDB 6.2:
5162 * Fix for ``many threads''
5164 On GNU/Linux systems that use the NPTL threads library, a program
5165 rapidly creating and deleting threads would confuse GDB leading to the
5168 ptrace: No such process.
5169 thread_db_get_info: cannot get thread info: generic error
5171 This problem has been fixed.
5173 * "-async" and "-noasync" options removed.
5175 Support for the broken "-noasync" option has been removed (it caused
5178 * New ``start'' command.
5180 This command runs the program until the begining of the main procedure.
5182 * New BSD Kernel Data Access Library (libkvm) interface
5184 Using ``target kvm'' it is now possible to debug kernel core dumps and
5185 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5186 platforms. Currently supported (native-only) configurations are:
5188 FreeBSD/amd64 x86_64-*-freebsd*
5189 FreeBSD/i386 i?86-*-freebsd*
5190 NetBSD/i386 i?86-*-netbsd*
5191 NetBSD/m68k m68*-*-netbsd*
5192 NetBSD/sparc sparc-*-netbsd*
5193 OpenBSD/amd64 x86_64-*-openbsd*
5194 OpenBSD/i386 i?86-*-openbsd*
5195 OpenBSD/m68k m68*-openbsd*
5196 OpenBSD/sparc sparc-*-openbsd*
5198 * Signal trampoline code overhauled
5200 Many generic problems with GDB's signal handling code have been fixed.
5201 These include: backtraces through non-contiguous stacks; recognition
5202 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5203 call; backtrace through a signal trampoline; step into and out of
5204 signal handlers; and single-stepping in the signal trampoline.
5206 Please note that kernel bugs are a limiting factor here. These
5207 features have been shown to work on an s390 GNU/Linux system that
5208 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5210 * Cygwin support for DWARF 2 added.
5212 * New native configurations
5214 GNU/Linux/hppa hppa*-*-linux*
5215 OpenBSD/hppa hppa*-*-openbsd*
5216 OpenBSD/m68k m68*-*-openbsd*
5217 OpenBSD/m88k m88*-*-openbsd*
5218 OpenBSD/powerpc powerpc-*-openbsd*
5219 NetBSD/vax vax-*-netbsd*
5220 OpenBSD/vax vax-*-openbsd*
5222 * END-OF-LIFE frame compatibility module
5224 GDB's internal frame infrastructure has been completely rewritten.
5225 The new infrastructure making it possible to support key new features
5226 including DWARF 2 Call Frame Information. To aid in the task of
5227 migrating old configurations to this new infrastructure, a
5228 compatibility module, that allowed old configurations to continue to
5229 work, was also included.
5231 GDB 6.2 will be the last release to include this frame compatibility
5232 module. This change directly impacts the following configurations:
5242 Unless there is activity to revive these configurations, they will be
5243 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5245 * REMOVED configurations and files
5247 Sun 3, running SunOS 3 m68*-*-sunos3*
5248 Sun 3, running SunOS 4 m68*-*-sunos4*
5249 Sun 2, running SunOS 3 m68000-*-sunos3*
5250 Sun 2, running SunOS 4 m68000-*-sunos4*
5251 Motorola 680x0 running LynxOS m68*-*-lynxos*
5252 AT&T 3b1/Unix pc m68*-att-*
5253 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5254 decstation mips-dec-* mips-little-*
5255 riscos mips-*-riscos* mips-*-sysv*
5256 sonymips mips-sony-*
5257 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5259 *** Changes in GDB 6.1.1:
5261 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5263 The TUI (Text-mode User Interface) is now built as part of a default
5264 GDB configuration. It is enabled by either selecting the TUI with the
5265 command line option "-i=tui" or by running the separate "gdbtui"
5266 program. For more information on the TUI, see the manual "Debugging
5269 * Pending breakpoint support (also included in GDB 6.1)
5271 Support has been added to allow you to specify breakpoints in shared
5272 libraries that have not yet been loaded. If a breakpoint location
5273 cannot be found, and the "breakpoint pending" option is set to auto,
5274 GDB queries you if you wish to make the breakpoint pending on a future
5275 shared-library load. If and when GDB resolves the breakpoint symbol,
5276 the pending breakpoint is removed as one or more regular breakpoints
5279 Pending breakpoints are very useful for GCJ Java debugging.
5281 * Fixed ISO-C build problems
5283 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5284 non ISO-C code that stopped them being built using a more strict ISO-C
5285 compiler (e.g., IBM's C compiler).
5287 * Fixed build problem on IRIX 5
5289 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5290 wasn't able to compile compile on an IRIX 5 system.
5292 * Added execute permission to gdb/gdbserver/configure
5294 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5295 permission. This bug would cause configure to fail on a number of
5296 systems (Solaris, IRIX). Ref: server/519.
5298 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5300 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5301 has been updated to use constant array sizes.
5303 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5305 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5306 its generated DWARF Call Frame Info. This encoding was causing GDB to
5307 panic, that panic has been fixed. Ref: gdb/1628.
5309 * Fixed a problem when examining parameters in shared library code.
5311 When examining parameters in optimized shared library code generated
5312 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5313 not available''. GDB now correctly displays the variable's value.
5315 *** Changes in GDB 6.1:
5317 * Removed --with-mmalloc
5319 Support for the mmalloc memory manager has been removed, as it
5320 conflicted with the internal gdb byte cache.
5322 * Changes in AMD64 configurations
5324 The AMD64 target now includes the %cs and %ss registers. As a result
5325 the AMD64 remote protocol has changed; this affects the floating-point
5326 and SSE registers. If you rely on those registers for your debugging,
5327 you should upgrade gdbserver on the remote side.
5329 * Revised SPARC target
5331 The SPARC target has been completely revised, incorporating the
5332 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5333 support for LynxOS and SunOS 4 has been dropped. Calling functions
5334 from within GDB on operating systems with a non-executable stack
5335 (Solaris, OpenBSD) now works.
5339 GDB has a new C++ demangler which does a better job on the mangled
5340 names generated by current versions of g++. It also runs faster, so
5341 with this and other changes gdb should now start faster on large C++
5344 * DWARF 2 Location Expressions
5346 GDB support for location expressions has been extended to support function
5347 arguments and frame bases. Older versions of GDB could crash when they
5350 * C++ nested types and namespaces
5352 GDB's support for nested types and namespaces in C++ has been
5353 improved, especially if you use the DWARF 2 debugging format. (This
5354 is the default for recent versions of GCC on most platforms.)
5355 Specifically, if you have a class "Inner" defined within a class or
5356 namespace "Outer", then GDB realizes that the class's name is
5357 "Outer::Inner", not simply "Inner". This should greatly reduce the
5358 frequency of complaints about not finding RTTI symbols. In addition,
5359 if you are stopped at inside of a function defined within a namespace,
5360 GDB modifies its name lookup accordingly.
5362 * New native configurations
5364 NetBSD/amd64 x86_64-*-netbsd*
5365 OpenBSD/amd64 x86_64-*-openbsd*
5366 OpenBSD/alpha alpha*-*-openbsd*
5367 OpenBSD/sparc sparc-*-openbsd*
5368 OpenBSD/sparc64 sparc64-*-openbsd*
5370 * New debugging protocols
5372 M32R with SDI protocol m32r-*-elf*
5374 * "set prompt-escape-char" command deleted.
5376 The command "set prompt-escape-char" has been deleted. This command,
5377 and its very obscure effet on GDB's prompt, was never documented,
5378 tested, nor mentioned in the NEWS file.
5380 * OBSOLETE configurations and files
5382 Configurations that have been declared obsolete in this release have
5383 been commented out. Unless there is activity to revive these
5384 configurations, the next release of GDB will have their sources
5385 permanently REMOVED.
5387 Sun 3, running SunOS 3 m68*-*-sunos3*
5388 Sun 3, running SunOS 4 m68*-*-sunos4*
5389 Sun 2, running SunOS 3 m68000-*-sunos3*
5390 Sun 2, running SunOS 4 m68000-*-sunos4*
5391 Motorola 680x0 running LynxOS m68*-*-lynxos*
5392 AT&T 3b1/Unix pc m68*-att-*
5393 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5394 decstation mips-dec-* mips-little-*
5395 riscos mips-*-riscos* mips-*-sysv*
5396 sonymips mips-sony-*
5397 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5399 * REMOVED configurations and files
5401 SGI Irix-4.x mips-sgi-irix4 or iris4
5402 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5403 Z8000 simulator z8k-zilog-none or z8ksim
5404 Matsushita MN10200 w/simulator mn10200-*-*
5405 H8/500 simulator h8500-hitachi-hms or h8500hms
5406 HP/PA running BSD hppa*-*-bsd*
5407 HP/PA running OSF/1 hppa*-*-osf*
5408 HP/PA Pro target hppa*-*-pro*
5409 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5410 386BSD i[3456]86-*-bsd*
5411 Sequent family i[3456]86-sequent-sysv4*
5412 i[3456]86-sequent-sysv*
5413 i[3456]86-sequent-bsd*
5414 SPARC running LynxOS sparc-*-lynxos*
5415 SPARC running SunOS 4 sparc-*-sunos4*
5416 Tsqware Sparclet sparclet-*-*
5417 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5419 *** Changes in GDB 6.0:
5423 Support for debugging the Objective-C programming language has been
5424 integrated into GDB.
5426 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5428 DWARF 2's Call Frame Information makes available compiler generated
5429 information that more exactly describes the program's run-time stack.
5430 By using this information, GDB is able to provide more robust stack
5433 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5434 have been updated to use a new backtrace mechanism which includes
5435 DWARF 2 CFI support.
5439 GDB's remote protocol has been extended to include support for hosted
5440 file I/O (where the remote target uses GDB's file system). See GDB's
5441 remote protocol documentation for details.
5443 * All targets using the new architecture framework.
5445 All of GDB's targets have been updated to use the new internal
5446 architecture framework. The way is now open for future GDB releases
5447 to include cross-architecture native debugging support (i386 on amd64,
5450 * GNU/Linux's Thread Local Storage (TLS)
5452 GDB now includes support for for the GNU/Linux implementation of
5453 per-thread variables.
5455 * GNU/Linux's Native POSIX Thread Library (NPTL)
5457 GDB's thread code has been updated to work with either the new
5458 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5460 * Separate debug info.
5462 GDB, in conjunction with BINUTILS, now supports a mechanism for
5463 automatically loading debug information from a separate file. Instead
5464 of shipping full debug and non-debug versions of system libraries,
5465 system integrators can now instead ship just the stripped libraries
5466 and optional debug files.
5468 * DWARF 2 Location Expressions
5470 DWARF 2 Location Expressions allow the compiler to more completely
5471 describe the location of variables (even in optimized code) to the
5474 GDB now includes preliminary support for location expressions (support
5475 for DW_OP_piece is still missing).
5479 A number of long standing bugs that caused GDB to die while starting a
5480 Java application have been fixed. GDB's Java support is now
5481 considered "useable".
5483 * GNU/Linux support for fork, vfork, and exec.
5485 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5486 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5489 * GDB supports logging output to a file
5491 There are two new commands, "set logging" and "show logging", which can be
5492 used to capture GDB's output to a file.
5494 * The meaning of "detach" has changed for gdbserver
5496 The "detach" command will now resume the application, as documented. To
5497 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5500 * d10v, m68hc11 `regs' command deprecated
5502 The `info registers' command has been updated so that it displays the
5503 registers using a format identical to the old `regs' command.
5507 A new command, "maint set profile on/off", has been added. This command can
5508 be used to enable or disable profiling while running GDB, to profile a
5509 session or a set of commands. In addition there is a new configure switch,
5510 "--enable-profiling", which will cause GDB to be compiled with profiling
5511 data, for more informative profiling results.
5513 * Default MI syntax changed to "mi2".
5515 The default MI (machine interface) syntax, enabled by the command line
5516 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5517 "mi1", can be enabled by specifying the option "-i=mi1".
5519 Support for the original "mi0" syntax (included in GDB 5.0) has been
5522 Fix for gdb/192: removed extraneous space when displaying frame level.
5523 Fix for gdb/672: update changelist is now output in mi list format.
5524 Fix for gdb/702: a -var-assign that updates the value now shows up
5525 in a subsequent -var-update.
5527 * New native configurations.
5529 FreeBSD/amd64 x86_64-*-freebsd*
5531 * Multi-arched targets.
5533 HP/PA HPUX11 hppa*-*-hpux*
5534 Renesas M32R/D w/simulator m32r-*-elf*
5536 * OBSOLETE configurations and files
5538 Configurations that have been declared obsolete in this release have
5539 been commented out. Unless there is activity to revive these
5540 configurations, the next release of GDB will have their sources
5541 permanently REMOVED.
5543 Z8000 simulator z8k-zilog-none or z8ksim
5544 Matsushita MN10200 w/simulator mn10200-*-*
5545 H8/500 simulator h8500-hitachi-hms or h8500hms
5546 HP/PA running BSD hppa*-*-bsd*
5547 HP/PA running OSF/1 hppa*-*-osf*
5548 HP/PA Pro target hppa*-*-pro*
5549 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5550 Sequent family i[3456]86-sequent-sysv4*
5551 i[3456]86-sequent-sysv*
5552 i[3456]86-sequent-bsd*
5553 Tsqware Sparclet sparclet-*-*
5554 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5556 * REMOVED configurations and files
5559 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5560 IBM AIX PS/2 i[3456]86-*-aix
5561 i386 running Mach 3.0 i[3456]86-*-mach3*
5562 i386 running Mach i[3456]86-*-mach*
5563 i386 running OSF/1 i[3456]86-*osf1mk*
5564 HP/Apollo 68k Family m68*-apollo*-sysv*,
5566 m68*-hp-bsd*, m68*-hp-hpux*
5567 Argonaut Risc Chip (ARC) arc-*-*
5568 Mitsubishi D30V d30v-*-*
5569 Fujitsu FR30 fr30-*-elf*
5570 OS/9000 i[34]86-*-os9k
5571 I960 with MON960 i960-*-coff
5573 * MIPS $fp behavior changed
5575 The convenience variable $fp, for the MIPS, now consistently returns
5576 the address of the current frame's base. Previously, depending on the
5577 context, $fp could refer to either $sp or the current frame's base
5578 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5579 The GNU Source-Level Debugger''.
5581 *** Changes in GDB 5.3:
5583 * GNU/Linux shared library multi-threaded performance improved.
5585 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5586 `/proc', in preference to `ptrace' for memory reads. This may result
5587 in an improvement in the start-up time of multi-threaded, shared
5588 library applications when run under GDB. One GDB user writes: ``loads
5589 shared libs like mad''.
5591 * ``gdbserver'' now supports multi-threaded applications on some targets
5593 Support for debugging multi-threaded applications which use
5594 the GNU/Linux LinuxThreads package has been added for
5595 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5596 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5598 * GDB now supports C/C++ preprocessor macros.
5600 GDB now expands preprocessor macro invocations in C/C++ expressions,
5601 and provides various commands for showing macro definitions and how
5604 The new command `macro expand EXPRESSION' expands any macro
5605 invocations in expression, and shows the result.
5607 The new command `show macro MACRO-NAME' shows the definition of the
5608 macro named MACRO-NAME, and where it was defined.
5610 Most compilers don't include information about macros in the debugging
5611 information by default. In GCC 3.1, for example, you need to compile
5612 your program with the options `-gdwarf-2 -g3'. If the macro
5613 information is present in the executable, GDB will read it.
5615 * Multi-arched targets.
5617 DEC Alpha (partial) alpha*-*-*
5618 DEC VAX (partial) vax-*-*
5620 National Semiconductor NS32000 (partial) ns32k-*-*
5621 Motorola 68000 (partial) m68k-*-*
5622 Motorola MCORE mcore-*-*
5626 Fujitsu FRV architecture added by Red Hat frv*-*-*
5629 * New native configurations
5631 Alpha NetBSD alpha*-*-netbsd*
5632 SH NetBSD sh*-*-netbsdelf*
5633 MIPS NetBSD mips*-*-netbsd*
5634 UltraSPARC NetBSD sparc64-*-netbsd*
5636 * OBSOLETE configurations and files
5638 Configurations that have been declared obsolete in this release have
5639 been commented out. Unless there is activity to revive these
5640 configurations, the next release of GDB will have their sources
5641 permanently REMOVED.
5643 Mitsubishi D30V d30v-*-*
5644 OS/9000 i[34]86-*-os9k
5645 IBM AIX PS/2 i[3456]86-*-aix
5646 Fujitsu FR30 fr30-*-elf*
5647 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5648 Argonaut Risc Chip (ARC) arc-*-*
5649 i386 running Mach 3.0 i[3456]86-*-mach3*
5650 i386 running Mach i[3456]86-*-mach*
5651 i386 running OSF/1 i[3456]86-*osf1mk*
5652 HP/Apollo 68k Family m68*-apollo*-sysv*,
5654 m68*-hp-bsd*, m68*-hp-hpux*
5655 I960 with MON960 i960-*-coff
5657 * OBSOLETE languages
5659 CHILL, a Pascal like language used by telecommunications companies.
5661 * REMOVED configurations and files
5663 AMD 29k family via UDI a29k-amd-udi, udi29k
5664 A29K VxWorks a29k-*-vxworks
5665 AMD 29000 embedded, using EBMON a29k-none-none
5666 AMD 29000 embedded with COFF a29k-none-coff
5667 AMD 29000 embedded with a.out a29k-none-aout
5669 testsuite/gdb.hp/gdb.threads-hp/ directory
5671 * New command "set max-user-call-depth <nnn>"
5673 This command allows the user to limit the call depth of user-defined
5674 commands. The default is 1024.
5676 * Changes in FreeBSD/i386 native debugging.
5678 Support for the "generate-core-file" has been added.
5680 * New commands "dump", "append", and "restore".
5682 These commands allow data to be copied from target memory
5683 to a bfd-format or binary file (dump and append), and back
5684 from a file into memory (restore).
5686 * Improved "next/step" support on multi-processor Alpha Tru64.
5688 The previous single-step mechanism could cause unpredictable problems,
5689 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5690 of a software single-step mechanism prevents this.
5692 *** Changes in GDB 5.2.1:
5700 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5701 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5702 Fix, by Joel Brobecker imported from mainline.
5704 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5705 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5706 Fix, by Fred Fish, imported from mainline.
5708 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5709 Surprisingly enough, it works now.
5710 By Michal Ludvig, imported from mainline.
5712 i386 hardware watchpoint support:
5713 avoid misses on second run for some targets.
5714 By Pierre Muller, imported from mainline.
5716 *** Changes in GDB 5.2:
5718 * New command "set trust-readonly-sections on[off]".
5720 This command is a hint that tells gdb that read-only sections
5721 really are read-only (ie. that their contents will not change).
5722 In this mode, gdb will go to the object file rather than the
5723 target to read memory from read-only sections (such as ".text").
5724 This can be a significant performance improvement on some
5725 (notably embedded) targets.
5727 * New command "generate-core-file" (or "gcore").
5729 This new gdb command allows the user to drop a core file of the child
5730 process state at any time. So far it's been implemented only for
5731 GNU/Linux and Solaris, but should be relatively easily ported to other
5732 hosts. Argument is core file name (defaults to core.<pid>).
5734 * New command line option
5736 GDB now accepts --pid or -p followed by a process id.
5738 * Change in command line behavior -- corefiles vs. process ids.
5740 There is a subtle behavior in the way in which GDB handles
5741 command line arguments. The first non-flag argument is always
5742 a program to debug, but the second non-flag argument may either
5743 be a corefile or a process id. Previously, GDB would attempt to
5744 open the second argument as a corefile, and if that failed, would
5745 issue a superfluous error message and then attempt to attach it as
5746 a process. Now, if the second argument begins with a non-digit,
5747 it will be treated as a corefile. If it begins with a digit,
5748 GDB will attempt to attach it as a process, and if no such process
5749 is found, will then attempt to open it as a corefile.
5751 * Changes in ARM configurations.
5753 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5754 configuration is fully multi-arch.
5756 * New native configurations
5758 ARM NetBSD arm*-*-netbsd*
5759 x86 OpenBSD i[3456]86-*-openbsd*
5760 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5761 Sparc64 running FreeBSD sparc64-*-freebsd*
5765 Sanyo XStormy16 xstormy16-elf
5767 * OBSOLETE configurations and files
5769 Configurations that have been declared obsolete in this release have
5770 been commented out. Unless there is activity to revive these
5771 configurations, the next release of GDB will have their sources
5772 permanently REMOVED.
5774 AMD 29k family via UDI a29k-amd-udi, udi29k
5775 A29K VxWorks a29k-*-vxworks
5776 AMD 29000 embedded, using EBMON a29k-none-none
5777 AMD 29000 embedded with COFF a29k-none-coff
5778 AMD 29000 embedded with a.out a29k-none-aout
5780 testsuite/gdb.hp/gdb.threads-hp/ directory
5782 * REMOVED configurations and files
5784 TI TMS320C80 tic80-*-*
5786 PowerPC Solaris powerpcle-*-solaris*
5787 PowerPC Windows NT powerpcle-*-cygwin32
5788 PowerPC Netware powerpc-*-netware*
5789 Harris/CXUX m88k m88*-harris-cxux*
5790 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5791 ns32k-utek-sysv* ns32k-utek-*
5792 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5793 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5794 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5795 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5796 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5798 * Changes to command line processing
5800 The new `--args' feature can be used to specify command-line arguments
5801 for the inferior from gdb's command line.
5803 * Changes to key bindings
5805 There is a new `operate-and-get-next' function bound to `C-o'.
5807 *** Changes in GDB 5.1.1
5809 Fix compile problem on DJGPP.
5811 Fix a problem with floating-point registers on the i386 being
5814 Fix to stop GDB crashing on .debug_str debug info.
5816 Numerous documentation fixes.
5818 Numerous testsuite fixes.
5820 *** Changes in GDB 5.1:
5822 * New native configurations
5824 Alpha FreeBSD alpha*-*-freebsd*
5825 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5826 MIPS GNU/Linux mips*-*-linux*
5827 MIPS SGI Irix 6.x mips*-sgi-irix6*
5828 ia64 AIX ia64-*-aix*
5829 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5833 Motorola 68HC11 and 68HC12 m68hc11-elf
5835 UltraSparc running GNU/Linux sparc64-*-linux*
5837 * OBSOLETE configurations and files
5839 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5840 Harris/CXUX m88k m88*-harris-cxux*
5841 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5842 ns32k-utek-sysv* ns32k-utek-*
5843 TI TMS320C80 tic80-*-*
5845 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5846 PowerPC Solaris powerpcle-*-solaris*
5847 PowerPC Windows NT powerpcle-*-cygwin32
5848 PowerPC Netware powerpc-*-netware*
5849 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5850 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5851 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5852 Apple Macintosh (MPW) host N/A
5854 stuff.c (Program to stuff files into a specially prepared space in kdb)
5855 kdb-start.c (Main loop for the standalone kernel debugger)
5857 Configurations that have been declared obsolete in this release have
5858 been commented out. Unless there is activity to revive these
5859 configurations, the next release of GDB will have their sources
5860 permanently REMOVED.
5862 * REMOVED configurations and files
5864 Altos 3068 m68*-altos-*
5865 Convex c1-*-*, c2-*-*
5867 ARM RISCix arm-*-* (as host)
5871 * GDB has been converted to ISO C.
5873 GDB's source code has been converted to ISO C. In particular, the
5874 sources are fully protoized, and rely on standard headers being
5879 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5881 * The MI enabled by default.
5883 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5884 revised and enabled by default. Packages which use GDB as a debugging
5885 engine behind a UI or another front end are encouraged to switch to
5886 using the GDB/MI interface, instead of the old annotations interface
5887 which is now deprecated.
5889 * Support for debugging Pascal programs.
5891 GDB now includes support for debugging Pascal programs. The following
5892 main features are supported:
5894 - Pascal-specific data types such as sets;
5896 - automatic recognition of Pascal sources based on file-name
5899 - Pascal-style display of data types, variables, and functions;
5901 - a Pascal expression parser.
5903 However, some important features are not yet supported.
5905 - Pascal string operations are not supported at all;
5907 - there are some problems with boolean types;
5909 - Pascal type hexadecimal constants are not supported
5910 because they conflict with the internal variables format;
5912 - support for Pascal objects and classes is not full yet;
5914 - unlike Pascal, GDB is case-sensitive for symbol names.
5916 * Changes in completion.
5918 Commands such as `shell', `run' and `set args', which pass arguments
5919 to inferior programs, now complete on file names, similar to what
5920 users expect at the shell prompt.
5922 Commands which accept locations, such as `disassemble', `print',
5923 `breakpoint', `until', etc. now complete on filenames as well as
5924 program symbols. Thus, if you type "break foob TAB", and the source
5925 files linked into the programs include `foobar.c', that file name will
5926 be one of the candidates for completion. However, file names are not
5927 considered for completion after you typed a colon that delimits a file
5928 name from a name of a function in that file, as in "break foo.c:bar".
5930 `set demangle-style' completes on available demangling styles.
5932 * New platform-independent commands:
5934 It is now possible to define a post-hook for a command as well as a
5935 hook that runs before the command. For more details, see the
5936 documentation of `hookpost' in the GDB manual.
5938 * Changes in GNU/Linux native debugging.
5940 Support for debugging multi-threaded programs has been completely
5941 revised for all platforms except m68k and sparc. You can now debug as
5942 many threads as your system allows you to have.
5944 Attach/detach is supported for multi-threaded programs.
5946 Support for SSE registers was added for x86. This doesn't work for
5947 multi-threaded programs though.
5949 * Changes in MIPS configurations.
5951 Multi-arch support is enabled for all MIPS configurations.
5953 GDB can now be built as native debugger on SGI Irix 6.x systems for
5954 debugging n32 executables. (Debugging 64-bit executables is not yet
5957 * Unified support for hardware watchpoints in all x86 configurations.
5959 Most (if not all) native x86 configurations support hardware-assisted
5960 breakpoints and watchpoints in a unified manner. This support
5961 implements debug register sharing between watchpoints, which allows to
5962 put a virtually infinite number of watchpoints on the same address,
5963 and also supports watching regions up to 16 bytes with several debug
5966 The new maintenance command `maintenance show-debug-regs' toggles
5967 debugging print-outs in functions that insert, remove, and test
5968 watchpoints and hardware breakpoints.
5970 * Changes in the DJGPP native configuration.
5972 New command ``info dos sysinfo'' displays assorted information about
5973 the CPU, OS, memory, and DPMI server.
5975 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5976 display information about segment descriptors stored in GDT, LDT, and
5979 New commands ``info dos pde'' and ``info dos pte'' display entries
5980 from Page Directory and Page Tables (for now works with CWSDPMI only).
5981 New command ``info dos address-pte'' displays the Page Table entry for
5982 a given linear address.
5984 GDB can now pass command lines longer than 126 characters to the
5985 program being debugged (requires an update to the libdbg.a library
5986 which is part of the DJGPP development kit).
5988 DWARF2 debug info is now supported.
5990 It is now possible to `step' and `next' through calls to `longjmp'.
5992 * Changes in documentation.
5994 All GDB documentation was converted to GFDL, the GNU Free
5995 Documentation License.
5997 Tracepoints-related commands are now fully documented in the GDB
6000 TUI, the Text-mode User Interface, is now documented in the manual.
6002 Tracepoints-related commands are now fully documented in the GDB
6005 The "GDB Internals" manual now has an index. It also includes
6006 documentation of `ui_out' functions, GDB coding standards, x86
6007 hardware watchpoints, and memory region attributes.
6009 * GDB's version number moved to ``version.in''
6011 The Makefile variable VERSION has been replaced by the file
6012 ``version.in''. People creating GDB distributions should update the
6013 contents of this file.
6017 GUD support is now a standard part of the EMACS distribution.
6019 *** Changes in GDB 5.0:
6021 * Improved support for debugging FP programs on x86 targets
6023 Unified and much-improved support for debugging floating-point
6024 programs on all x86 targets. In particular, ``info float'' now
6025 displays the FP registers in the same format on all x86 targets, with
6026 greater level of detail.
6028 * Improvements and bugfixes in hardware-assisted watchpoints
6030 It is now possible to watch array elements, struct members, and
6031 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6032 on x86 targets no longer erroneously trigger when the address is
6035 * Improvements in the native DJGPP version of GDB
6037 The distribution now includes all the scripts and auxiliary files
6038 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6039 machines ``out of the box''.
6041 The DJGPP version can now debug programs that use signals. It is
6042 possible to catch signals that happened in the debuggee, deliver
6043 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6044 would kill the program being debugged.) Programs that hook hardware
6045 interrupts (keyboard, timer, etc.) can also be debugged.
6047 It is now possible to debug DJGPP programs that redirect their
6048 standard handles or switch them to raw (as opposed to cooked) mode, or
6049 even close them. The command ``run < foo > bar'' works as expected,
6050 and ``info terminal'' reports useful information about the debuggee's
6051 terminal, including raw/cooked mode, redirection, etc.
6053 The DJGPP version now uses termios functions for console I/O, which
6054 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6057 DOS-style file names with drive letters are now fully supported by
6060 It is now possible to debug DJGPP programs that switch their working
6061 directory. It is also possible to rerun the debuggee any number of
6062 times without restarting GDB; thus, you can use the same setup,
6063 breakpoints, etc. for many debugging sessions.
6065 * New native configurations
6067 ARM GNU/Linux arm*-*-linux*
6068 PowerPC GNU/Linux powerpc-*-linux*
6072 Motorola MCore mcore-*-*
6073 x86 VxWorks i[3456]86-*-vxworks*
6074 PowerPC VxWorks powerpc-*-vxworks*
6075 TI TMS320C80 tic80-*-*
6077 * OBSOLETE configurations
6079 Altos 3068 m68*-altos-*
6080 Convex c1-*-*, c2-*-*
6082 ARM RISCix arm-*-* (as host)
6085 Configurations that have been declared obsolete will be commented out,
6086 but the code will be left in place. If there is no activity to revive
6087 these configurations before the next release of GDB, the sources will
6088 be permanently REMOVED.
6090 * Gould support removed
6092 Support for the Gould PowerNode and NP1 has been removed.
6094 * New features for SVR4
6096 On SVR4 native platforms (such as Solaris), if you attach to a process
6097 without first loading a symbol file, GDB will now attempt to locate and
6098 load symbols from the running process's executable file.
6100 * Many C++ enhancements
6102 C++ support has been greatly improved. Overload resolution now works properly
6103 in almost all cases. RTTI support is on the way.
6105 * Remote targets can connect to a sub-program
6107 A popen(3) style serial-device has been added. This device starts a
6108 sub-process (such as a stand-alone simulator) and then communicates
6109 with that. The sub-program to run is specified using the syntax
6110 ``|<program> <args>'' vis:
6112 (gdb) set remotedebug 1
6113 (gdb) target extended-remote |mn10300-elf-sim program-args
6115 * MIPS 64 remote protocol
6117 A long standing bug in the mips64 remote protocol where by GDB
6118 expected certain 32 bit registers (ex SR) to be transfered as 32
6119 instead of 64 bits has been fixed.
6121 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6122 added to provide backward compatibility with older versions of GDB.
6124 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6126 The command ``set remotebinarydownload'' command has been replaced by
6127 ``set remote X-packet''. Other commands in ``set remote'' family
6128 include ``set remote P-packet''.
6130 * Breakpoint commands accept ranges.
6132 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6133 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6134 ``tracepoint passcount'' also accepts a range of tracepoints.
6136 * ``apropos'' command added.
6138 The ``apropos'' command searches through command names and
6139 documentation strings, printing out matches, making it much easier to
6140 try to find a command that does what you are looking for.
6144 A new machine oriented interface (MI) has been added to GDB. This
6145 interface is designed for debug environments running GDB as a separate
6146 process. This is part of the long term libGDB project. See the
6147 "GDB/MI" chapter of the GDB manual for further information. It can be
6148 enabled by configuring with:
6150 .../configure --enable-gdbmi
6152 *** Changes in GDB-4.18:
6154 * New native configurations
6156 HP-UX 10.20 hppa*-*-hpux10.20
6157 HP-UX 11.x hppa*-*-hpux11.0*
6158 M68K GNU/Linux m68*-*-linux*
6162 Fujitsu FR30 fr30-*-elf*
6163 Intel StrongARM strongarm-*-*
6164 Mitsubishi D30V d30v-*-*
6166 * OBSOLETE configurations
6168 Gould PowerNode, NP1 np1-*-*, pn-*-*
6170 Configurations that have been declared obsolete will be commented out,
6171 but the code will be left in place. If there is no activity to revive
6172 these configurations before the next release of GDB, the sources will
6173 be permanently REMOVED.
6177 As a compatibility experiment, GDB's source files buildsym.h and
6178 buildsym.c have been converted to pure standard C, no longer
6179 containing any K&R compatibility code. We believe that all systems in
6180 use today either come with a standard C compiler, or have a GCC port
6181 available. If this is not true, please report the affected
6182 configuration to bug-gdb@gnu.org immediately. See the README file for
6183 information about getting a standard C compiler if you don't have one
6188 GDB now uses readline 2.2.
6190 * set extension-language
6192 You can now control the mapping between filename extensions and source
6193 languages by using the `set extension-language' command. For instance,
6194 you can ask GDB to treat .c files as C++ by saying
6195 set extension-language .c c++
6196 The command `info extensions' lists all of the recognized extensions
6197 and their associated languages.
6199 * Setting processor type for PowerPC and RS/6000
6201 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6202 you can use the `set processor' command to specify what variant of the
6203 PowerPC family you are debugging. The command
6207 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6208 following PowerPC and RS6000 variants:
6210 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6211 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6213 403GC IBM PowerPC 403GC
6214 505 Motorola PowerPC 505
6215 860 Motorola PowerPC 860 or 850
6216 601 Motorola PowerPC 601
6217 602 Motorola PowerPC 602
6218 603 Motorola/IBM PowerPC 603 or 603e
6219 604 Motorola PowerPC 604 or 604e
6220 750 Motorola/IBM PowerPC 750 or 750
6222 At the moment, this command just tells GDB what to name the
6223 special-purpose processor registers. Since almost all the affected
6224 registers are inaccessible to user-level programs, this command is
6225 only useful for remote debugging in its present form.
6229 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6230 more extensive support for HP-UX. Added features include shared
6231 library support, kernel threads and hardware watchpoints for 11.00,
6232 support for HP's ANSI C and C++ compilers, and a compatibility mode
6233 for xdb and dbx commands.
6237 HP's donation includes the new concept of catchpoints, which is a
6238 generalization of the old catch command. On HP-UX, it is now possible
6239 to catch exec, fork, and vfork, as well as library loading.
6241 This means that the existing catch command has changed; its first
6242 argument now specifies the type of catch to be set up. See the
6243 output of "help catch" for a list of catchpoint types.
6245 * Debugging across forks
6247 On HP-UX, you can choose which process to debug when a fork() happens
6252 HP has donated a curses-based terminal user interface (TUI). To get
6253 it, build with --enable-tui. Although this can be enabled for any
6254 configuration, at present it only works for native HP debugging.
6256 * GDB remote protocol additions
6258 A new protocol packet 'X' that writes binary data is now available.
6259 Default behavior is to try 'X', then drop back to 'M' if the stub
6260 fails to respond. The settable variable `remotebinarydownload'
6261 allows explicit control over the use of 'X'.
6263 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6264 full 64-bit address. The command
6266 set remoteaddresssize 32
6268 can be used to revert to the old behaviour. For existing remote stubs
6269 the change should not be noticed, as the additional address information
6272 In order to assist in debugging stubs, you may use the maintenance
6273 command `packet' to send any text string to the stub. For instance,
6275 maint packet heythere
6277 sends the packet "$heythere#<checksum>". Note that it is very easy to
6278 disrupt a debugging session by sending the wrong packet at the wrong
6281 The compare-sections command allows you to compare section data on the
6282 target to what is in the executable file without uploading or
6283 downloading, by comparing CRC checksums.
6285 * Tracing can collect general expressions
6287 You may now collect general expressions at tracepoints. This requires
6288 further additions to the target-side stub; see tracepoint.c and
6289 doc/agentexpr.texi for further details.
6291 * mask-address variable for Mips
6293 For Mips targets, you may control the zeroing of the upper 32 bits of
6294 a 64-bit address by entering `set mask-address on'. This is mainly
6295 of interest to users of embedded R4xxx and R5xxx processors.
6297 * Higher serial baud rates
6299 GDB's serial code now allows you to specify baud rates 57600, 115200,
6300 230400, and 460800 baud. (Note that your host system may not be able
6301 to achieve all of these rates.)
6305 The i960 configuration now includes an initial implementation of a
6306 builtin simulator, contributed by Jim Wilson.
6309 *** Changes in GDB-4.17:
6311 * New native configurations
6313 Alpha GNU/Linux alpha*-*-linux*
6314 Unixware 2.x i[3456]86-unixware2*
6315 Irix 6.x mips*-sgi-irix6*
6316 PowerPC GNU/Linux powerpc-*-linux*
6317 PowerPC Solaris powerpcle-*-solaris*
6318 Sparc GNU/Linux sparc-*-linux*
6319 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6323 Argonaut Risc Chip (ARC) arc-*-*
6324 Hitachi H8/300S h8300*-*-*
6325 Matsushita MN10200 w/simulator mn10200-*-*
6326 Matsushita MN10300 w/simulator mn10300-*-*
6327 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6328 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6329 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6330 Mitsubishi D10V w/simulator d10v-*-*
6331 Mitsubishi M32R/D w/simulator m32r-*-elf*
6332 Tsqware Sparclet sparclet-*-*
6333 NEC V850 w/simulator v850-*-*
6335 * New debugging protocols
6337 ARM with RDI protocol arm*-*-*
6338 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6339 DDB and LSI variants of PMON protocol mips*-*-*
6340 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6341 PowerPC with SDS protocol powerpc{,le}-*-eabi
6342 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6346 All configurations can now understand and use the DWARF 2 debugging
6347 format. The choice is automatic, if the symbol file contains DWARF 2
6352 GDB now includes basic Java language support. This support is
6353 only useful with Java compilers that produce native machine code.
6355 * solib-absolute-prefix and solib-search-path
6357 For SunOS and SVR4 shared libraries, you may now set the prefix for
6358 loading absolute shared library symbol files, and the search path for
6359 locating non-absolute shared library symbol files.
6361 * Live range splitting
6363 GDB can now effectively debug code for which GCC has performed live
6364 range splitting as part of its optimization. See gdb/doc/LRS for
6365 more details on the expected format of the stabs information.
6369 GDB's support for the GNU Hurd, including thread debugging, has been
6370 updated to work with current versions of the Hurd.
6374 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6375 instruction set. ARM GDB automatically detects when Thumb
6376 instructions are in use, and adjusts disassembly and backtracing
6381 GDB's MIPS target configurations now handle the MIP16 16-bit
6386 GDB now includes support for overlays; if an executable has been
6387 linked such that multiple sections are based at the same address, GDB
6388 will decide which section to use for symbolic info. You can choose to
6389 control the decision manually, using overlay commands, or implement
6390 additional target-side support and use "overlay load-target" to bring
6391 in the overlay mapping. Do "help overlay" for more detail.
6395 The command "info symbol <address>" displays information about
6396 the symbol at the specified address.
6400 The standard remote protocol now includes an extension that allows
6401 asynchronous collection and display of trace data. This requires
6402 extensive support in the target-side debugging stub. Tracing mode
6403 includes a new interaction mode in GDB and new commands: see the
6404 file tracepoint.c for more details.
6408 Configurations for embedded MIPS now include a simulator contributed
6409 by Cygnus Solutions. The simulator supports the instruction sets
6410 of most MIPS variants.
6414 Sparc configurations may now include the ERC32 simulator contributed
6415 by the European Space Agency. The simulator is not built into
6416 Sparc targets by default; configure with --enable-sim to include it.
6420 For target configurations that may include multiple variants of a
6421 basic architecture (such as MIPS and SH), you may now set the
6422 architecture explicitly. "set arch" sets, "info arch" lists
6423 the possible architectures.
6425 *** Changes in GDB-4.16:
6427 * New native configurations
6429 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6430 M68K NetBSD m68k-*-netbsd*
6431 PowerPC AIX 4.x powerpc-*-aix*
6432 PowerPC MacOS powerpc-*-macos*
6433 PowerPC Windows NT powerpcle-*-cygwin32
6434 RS/6000 AIX 4.x rs6000-*-aix4*
6438 ARM with RDP protocol arm-*-*
6439 I960 with MON960 i960-*-coff
6440 MIPS VxWorks mips*-*-vxworks*
6441 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6442 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6444 Matra Sparclet sparclet-*-*
6448 The powerpc-eabi configuration now includes the PSIM simulator,
6449 contributed by Andrew Cagney, with assistance from Mike Meissner.
6450 PSIM is a very elaborate model of the PowerPC, including not only
6451 basic instruction set execution, but also details of execution unit
6452 performance and I/O hardware. See sim/ppc/README for more details.
6456 GDB now works with Solaris 2.5.
6458 * Windows 95/NT native
6460 GDB will now work as a native debugger on Windows 95 and Windows NT.
6461 To build it from source, you must use the "gnu-win32" environment,
6462 which uses a DLL to emulate enough of Unix to run the GNU tools.
6463 Further information, binaries, and sources are available at
6464 ftp.cygnus.com, under pub/gnu-win32.
6466 * dont-repeat command
6468 If a user-defined command includes the command `dont-repeat', then the
6469 command will not be repeated if the user just types return. This is
6470 useful if the command is time-consuming to run, so that accidental
6471 extra keystrokes don't run the same command many times.
6473 * Send break instead of ^C
6475 The standard remote protocol now includes an option to send a break
6476 rather than a ^C to the target in order to interrupt it. By default,
6477 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6479 * Remote protocol timeout
6481 The standard remote protocol includes a new variable `remotetimeout'
6482 that allows you to set the number of seconds before GDB gives up trying
6483 to read from the target. The default value is 2.
6485 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6487 By default GDB will automatically keep track of objects as they are
6488 loaded and unloaded by the dynamic linker. By using the command `set
6489 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6490 when shared library events occur, thus allowing you to set breakpoints
6491 in shared libraries which are explicitly loaded by the inferior.
6493 Note this feature does not work on hpux8. On hpux9 you must link
6494 /usr/lib/end.o into your program. This feature should work
6495 automatically on hpux10.
6497 * Irix 5.x hardware watchpoint support
6499 Irix 5 configurations now support the use of hardware watchpoints.
6501 * Mips protocol "SYN garbage limit"
6503 When debugging a Mips target using the `target mips' protocol, you
6504 may set the number of characters that GDB will ignore by setting
6505 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6506 every character. The default value is 1050.
6508 * Recording and replaying remote debug sessions
6510 If you set `remotelogfile' to the name of a file, gdb will write to it
6511 a recording of a remote debug session. This recording may then be
6512 replayed back to gdb using "gdbreplay". See gdbserver/README for
6513 details. This is useful when you have a problem with GDB while doing
6514 remote debugging; you can make a recording of the session and send it
6515 to someone else, who can then recreate the problem.
6517 * Speedups for remote debugging
6519 GDB includes speedups for downloading and stepping MIPS systems using
6520 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6521 and more efficient S-record downloading.
6523 * Memory use reductions and statistics collection
6525 GDB now uses less memory and reports statistics about memory usage.
6526 Try the `maint print statistics' command, for example.
6528 *** Changes in GDB-4.15:
6530 * Psymtabs for XCOFF
6532 The symbol reader for AIX GDB now uses partial symbol tables. This
6533 can greatly improve startup time, especially for large executables.
6535 * Remote targets use caching
6537 Remote targets now use a data cache to speed up communication with the
6538 remote side. The data cache could lead to incorrect results because
6539 it doesn't know about volatile variables, thus making it impossible to
6540 debug targets which use memory mapped I/O devices. `set remotecache
6541 off' turns the the data cache off.
6543 * Remote targets may have threads
6545 The standard remote protocol now includes support for multiple threads
6546 in the target system, using new protocol commands 'H' and 'T'. See
6547 gdb/remote.c for details.
6551 If GDB is configured with `--enable-netrom', then it will include
6552 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6553 acts as though it is a bank of ROM on the target board, but you can
6554 write into it over the network. GDB's support consists only of
6555 support for fast loading into the emulated ROM; to debug, you must use
6556 another protocol, such as standard remote protocol. The usual
6557 sequence is something like
6559 target nrom <netrom-hostname>
6561 target remote <netrom-hostname>:1235
6565 GDB now includes support for the Apple Macintosh, as a host only. It
6566 may be run as either an MPW tool or as a standalone application, and
6567 it can debug through the serial port. All the usual GDB commands are
6568 available, but to the target command, you must supply "serial" as the
6569 device type instead of "/dev/ttyXX". See mpw-README in the main
6570 directory for more information on how to build. The MPW configuration
6571 scripts */mpw-config.in support only a few targets, and only the
6572 mips-idt-ecoff target has been tested.
6576 GDB configuration now uses autoconf. This is not user-visible,
6577 but does simplify configuration and building.
6581 GDB now supports hpux10.
6583 *** Changes in GDB-4.14:
6585 * New native configurations
6587 x86 FreeBSD i[345]86-*-freebsd
6588 x86 NetBSD i[345]86-*-netbsd
6589 NS32k NetBSD ns32k-*-netbsd
6590 Sparc NetBSD sparc-*-netbsd
6594 A29K VxWorks a29k-*-vxworks
6595 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6596 CPU32 EST-300 emulator m68*-*-est*
6597 PowerPC ELF powerpc-*-elf
6600 * Alpha OSF/1 support for procfs
6602 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6603 possible to attach to running processes. As the mounting of the /proc
6604 filesystem is optional on the Alpha, GDB automatically determines
6605 the availability of /proc during startup. This can lead to problems
6606 if /proc is unmounted after GDB has been started.
6608 * Arguments to user-defined commands
6610 User commands may accept up to 10 arguments separated by whitespace.
6611 Arguments are accessed within the user command via $arg0..$arg9. A
6614 print $arg0 + $arg1 + $arg2
6616 To execute the command use:
6619 Defines the command "adder" which prints the sum of its three arguments.
6620 Note the arguments are text substitutions, so they may reference variables,
6621 use complex expressions, or even perform inferior function calls.
6623 * New `if' and `while' commands
6625 This makes it possible to write more sophisticated user-defined
6626 commands. Both commands take a single argument, which is the
6627 expression to evaluate, and must be followed by the commands to
6628 execute, one per line, if the expression is nonzero, the list being
6629 terminated by the word `end'. The `if' command list may include an
6630 `else' word, which causes the following commands to be executed only
6631 if the expression is zero.
6633 * Fortran source language mode
6635 GDB now includes partial support for Fortran 77. It will recognize
6636 Fortran programs and can evaluate a subset of Fortran expressions, but
6637 variables and functions may not be handled correctly. GDB will work
6638 with G77, but does not yet know much about symbols emitted by other
6641 * Better HPUX support
6643 Most debugging facilities now work on dynamic executables for HPPAs
6644 running hpux9 or later. You can attach to running dynamically linked
6645 processes, but by default the dynamic libraries will be read-only, so
6646 for instance you won't be able to put breakpoints in them. To change
6647 that behavior do the following before running the program:
6653 This will cause the libraries to be mapped private and read-write.
6654 To revert to the normal behavior, do this:
6660 You cannot set breakpoints or examine data in the library until after
6661 the library is loaded if the function/data symbols do not have
6664 GDB can now also read debug symbols produced by the HP C compiler on
6665 HPPAs (sorry, no C++, Fortran or 68k support).
6667 * Target byte order now dynamically selectable
6669 You can choose which byte order to use with a target system, via the
6670 commands "set endian big" and "set endian little", and you can see the
6671 current setting by using "show endian". You can also give the command
6672 "set endian auto", in which case GDB will use the byte order
6673 associated with the executable. Currently, only embedded MIPS
6674 configurations support dynamic selection of target byte order.
6676 * New DOS host serial code
6678 This version uses DPMI interrupts to handle buffered I/O, so you
6679 no longer need to run asynctsr when debugging boards connected to
6682 *** Changes in GDB-4.13:
6684 * New "complete" command
6686 This lists all the possible completions for the rest of the line, if it
6687 were to be given as a command itself. This is intended for use by emacs.
6689 * Trailing space optional in prompt
6691 "set prompt" no longer adds a space for you after the prompt you set. This
6692 allows you to set a prompt which ends in a space or one that does not.
6694 * Breakpoint hit counts
6696 "info break" now displays a count of the number of times the breakpoint
6697 has been hit. This is especially useful in conjunction with "ignore"; you
6698 can ignore a large number of breakpoint hits, look at the breakpoint info
6699 to see how many times the breakpoint was hit, then run again, ignoring one
6700 less than that number, and this will get you quickly to the last hit of
6703 * Ability to stop printing at NULL character
6705 "set print null-stop" will cause GDB to stop printing the characters of
6706 an array when the first NULL is encountered. This is useful when large
6707 arrays actually contain only short strings.
6709 * Shared library breakpoints
6711 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6712 breakpoints in shared libraries before the executable is run.
6714 * Hardware watchpoints
6716 There is a new hardware breakpoint for the watch command for sparclite
6717 targets. See gdb/sparclite/hw_breakpoint.note.
6719 Hardware watchpoints are also now supported under GNU/Linux.
6723 Annotations have been added. These are for use with graphical interfaces,
6724 and are still experimental. Currently only gdba.el uses these.
6726 * Improved Irix 5 support
6728 GDB now works properly with Irix 5.2.
6730 * Improved HPPA support
6732 GDB now works properly with the latest GCC and GAS.
6734 * New native configurations
6736 Sequent PTX4 i[34]86-sequent-ptx4
6737 HPPA running OSF/1 hppa*-*-osf*
6738 Atari TT running SVR4 m68*-*-sysv4*
6739 RS/6000 LynxOS rs6000-*-lynxos*
6743 OS/9000 i[34]86-*-os9k
6744 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6747 * Hitachi SH7000 and E7000-PC ICE support
6749 There is now support for communicating with the Hitachi E7000-PC ICE.
6750 This is available automatically when GDB is configured for the SH.
6754 As usual, a variety of small fixes and improvements, both generic
6755 and configuration-specific. See the ChangeLog for more detail.
6757 *** Changes in GDB-4.12:
6759 * Irix 5 is now supported
6763 GDB-4.12 on the HPPA has a number of changes which make it unable
6764 to debug the output from the currently released versions of GCC and
6765 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6766 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6767 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6770 *** Changes in GDB-4.11:
6772 * User visible changes:
6776 The "set remotedebug" option is now consistent between the mips remote
6777 target, remote targets using the gdb-specific protocol, UDI (AMD's
6778 debug protocol for the 29k) and the 88k bug monitor. It is now an
6779 integer specifying a debug level (normally 0 or 1, but 2 means more
6780 debugging info for the mips target).
6782 * DEC Alpha native support
6784 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6785 debug info, but GDB works fairly well with the DEC compiler and should
6786 work with a future GCC release. See the README file for a few
6787 Alpha-specific notes.
6789 * Preliminary thread implementation
6791 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6793 * LynxOS native and target support for 386
6795 This release has been hosted on LynxOS 2.2, and also can be configured
6796 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6799 * Improvements in C++ mangling/demangling.
6801 This release has much better g++ debugging, specifically in name
6802 mangling/demangling, virtual function calls, print virtual table,
6803 call methods, ...etc.
6805 *** Changes in GDB-4.10:
6807 * User visible changes:
6809 Remote debugging using the GDB-specific (`target remote') protocol now
6810 supports the `load' command. This is only useful if you have some
6811 other way of getting the stub to the target system, and you can put it
6812 somewhere in memory where it won't get clobbered by the download.
6814 Filename completion now works.
6816 When run under emacs mode, the "info line" command now causes the
6817 arrow to point to the line specified. Also, "info line" prints
6818 addresses in symbolic form (as well as hex).
6820 All vxworks based targets now support a user settable option, called
6821 vxworks-timeout. This option represents the number of seconds gdb
6822 should wait for responses to rpc's. You might want to use this if
6823 your vxworks target is, perhaps, a slow software simulator or happens
6824 to be on the far side of a thin network line.
6828 This release contains support for using a DEC alpha as a GDB host for
6829 cross debugging. Native alpha debugging is not supported yet.
6832 *** Changes in GDB-4.9:
6836 This is the first GDB release which is accompanied by a matching testsuite.
6837 The testsuite requires installation of dejagnu, which should be available
6838 via ftp from most sites that carry GNU software.
6842 'Cfront' style demangling has had its name changed to 'ARM' style, to
6843 emphasize that it was written from the specifications in the C++ Annotated
6844 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6845 disclaimers, it still generated too much confusion with users attempting to
6846 use gdb with AT&T cfront.
6850 GDB now uses a standard remote interface to a simulator library.
6851 So far, the library contains simulators for the Zilog Z8001/2, the
6852 Hitachi H8/300, H8/500 and Super-H.
6854 * New targets supported
6856 H8/300 simulator h8300-hitachi-hms or h8300hms
6857 H8/500 simulator h8500-hitachi-hms or h8500hms
6858 SH simulator sh-hitachi-hms or sh
6859 Z8000 simulator z8k-zilog-none or z8ksim
6860 IDT MIPS board over serial line mips-idt-ecoff
6862 Cross-debugging to GO32 targets is supported. It requires a custom
6863 version of the i386-stub.c module which is integrated with the
6864 GO32 memory extender.
6866 * New remote protocols
6868 MIPS remote debugging protocol.
6870 * New source languages supported
6872 This version includes preliminary support for Chill, a Pascal like language
6873 used by telecommunications companies. Chill support is also being integrated
6874 into the GNU compiler, but we don't know when it will be publically available.
6877 *** Changes in GDB-4.8:
6879 * HP Precision Architecture supported
6881 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6882 version of this support was available as a set of patches from the
6883 University of Utah. GDB does not support debugging of programs
6884 compiled with the HP compiler, because HP will not document their file
6885 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6886 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6888 Many problems in the preliminary version have been fixed.
6890 * Faster and better demangling
6892 We have improved template demangling and fixed numerous bugs in the GNU style
6893 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6894 character types (wchar_t) are now supported. Demangling of each symbol is now
6895 only done once, and is cached when the symbol table for a file is read in.
6896 This results in a small increase in memory usage for C programs, a moderate
6897 increase in memory usage for C++ programs, and a fantastic speedup in
6900 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6901 from the specifications in the Annotated Reference Manual, which AT&T's
6902 compiler does not actually implement.
6904 * G++ multiple inheritance compiler problem
6906 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6907 inheritance lattices was reworked to properly discover ambiguities. We
6908 recently found an example which causes this new algorithm to fail in a
6909 very subtle way, producing bad debug information for those classes.
6910 The file 'gcc.patch' (in this directory) can be applied to gcc to
6911 circumvent the problem. A future GCC release will contain a complete
6914 The previous G++ debug info problem (mentioned below for the gdb-4.7
6915 release) is fixed in gcc version 2.3.2.
6917 * Improved configure script
6919 The `configure' script will now attempt to guess your system type if
6920 you don't supply a host system type. The old scheme of supplying a
6921 host system triplet is preferable over using this. All the magic is
6922 done in the new `config.guess' script. Examine it for details.
6924 We have also brought our configure script much more in line with the FSF's
6925 version. It now supports the --with-xxx options. In particular,
6926 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6927 The resulting GDB will not be able to read arbitrary object file formats --
6928 only the format ``expected'' to be used on the configured target system.
6929 We hope to make this the default in a future release.
6931 * Documentation improvements
6933 There's new internal documentation on how to modify GDB, and how to
6934 produce clean changes to the code. We implore people to read it
6935 before submitting changes.
6937 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6938 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6939 `info' files are also provided. To build `info' files from scratch,
6940 you will need the latest `makeinfo' release, which will be available in
6941 a future texinfo-X.Y release.
6943 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6944 We're not sure exactly which versions have this problem, but it has
6945 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6946 or better. If that isn't possible, there is a patch in
6947 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6948 around this problem.
6952 GDB now supports array constants that can be used in expressions typed in by
6953 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6954 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6957 The new directory `gdb/sparclite' contains a program that demonstrates
6958 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6960 * New native hosts supported
6962 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6963 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6965 * New targets supported
6967 AMD 29k family via UDI a29k-amd-udi or udi29k
6969 * New file formats supported
6971 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6972 HPUX core files, and SCO 3.2v2 core files.
6976 Attaching to processes now works again; thanks for the many bug reports.
6978 We have also stomped on a bunch of core dumps caused by
6979 printf_filtered("%s") problems.
6981 We eliminated a copyright problem on the rpc and ptrace header files
6982 for VxWorks, which was discovered at the last minute during the 4.7
6983 release. You should now be able to build a VxWorks GDB.
6985 You can now interrupt gdb while an attached process is running. This
6986 will cause the attached process to stop, and give control back to GDB.
6988 We fixed problems caused by using too many file descriptors
6989 for reading symbols from object files and libraries. This was
6990 especially a problem for programs that used many (~100) shared
6993 The `step' command now only enters a subroutine if there is line number
6994 information for the subroutine. Otherwise it acts like the `next'
6995 command. Previously, `step' would enter subroutines if there was
6996 any debugging information about the routine. This avoids problems
6997 when using `cc -g1' on MIPS machines.
6999 * Internal improvements
7001 GDB's internal interfaces have been improved to make it easier to support
7002 debugging of multiple languages in the future.
7004 GDB now uses a common structure for symbol information internally.
7005 Minimal symbols (derived from linkage symbols in object files), partial
7006 symbols (from a quick scan of debug information), and full symbols
7007 contain a common subset of information, making it easier to write
7008 shared code that handles any of them.
7010 * New command line options
7012 We now accept --silent as an alias for --quiet.
7016 The memory-mapped-malloc library is now licensed under the GNU Library
7017 General Public License.
7019 *** Changes in GDB-4.7:
7021 * Host/native/target split
7023 GDB has had some major internal surgery to untangle the support for
7024 hosts and remote targets. Now, when you configure GDB for a remote
7025 target, it will no longer load in all of the support for debugging
7026 local programs on the host. When fully completed and tested, this will
7027 ensure that arbitrary host/target combinations are possible.
7029 The primary conceptual shift is to separate the non-portable code in
7030 GDB into three categories. Host specific code is required any time GDB
7031 is compiled on that host, regardless of the target. Target specific
7032 code relates to the peculiarities of the target, but can be compiled on
7033 any host. Native specific code is everything else: it can only be
7034 built when the host and target are the same system. Child process
7035 handling and core file support are two common `native' examples.
7037 GDB's use of /proc for controlling Unix child processes is now cleaner.
7038 It has been split out into a single module under the `target_ops' vector,
7039 plus two native-dependent functions for each system that uses /proc.
7041 * New hosts supported
7043 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7044 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7045 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7047 * New targets supported
7049 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7050 68030 and CPU32 m68030-*-*, m68332-*-*
7052 * New native hosts supported
7054 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7055 (386bsd is not well tested yet)
7056 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7058 * New file formats supported
7060 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7061 supports reading of `a.out.adobe' object files, which are an a.out
7062 format extended with minimal information about multiple sections.
7066 `show copying' is the same as the old `info copying'.
7067 `show warranty' is the same as `info warrantee'.
7068 These were renamed for consistency. The old commands continue to work.
7070 `info handle' is a new alias for `info signals'.
7072 You can now define pre-command hooks, which attach arbitrary command
7073 scripts to any command. The commands in the hook will be executed
7074 prior to the user's command. You can also create a hook which will be
7075 executed whenever the program stops. See gdb.texinfo.
7079 We now deal with Cfront style name mangling, and can even extract type
7080 info from mangled symbols. GDB can automatically figure out which
7081 symbol mangling style your C++ compiler uses.
7083 Calling of methods and virtual functions has been improved as well.
7087 The crash that occured when debugging Sun Ansi-C compiled binaries is
7088 fixed. This was due to mishandling of the extra N_SO stabs output
7091 We also finally got Ultrix 4.2 running in house, and fixed core file
7092 support, with help from a dozen people on the net.
7094 John M. Farrell discovered that the reason that single-stepping was so
7095 slow on all of the Mips based platforms (primarily SGI and DEC) was
7096 that we were trying to demangle and lookup a symbol used for internal
7097 purposes on every instruction that was being stepped through. Changing
7098 the name of that symbol so that it couldn't be mistaken for a C++
7099 mangled symbol sped things up a great deal.
7101 Rich Pixley sped up symbol lookups in general by getting much smarter
7102 about when C++ symbol mangling is necessary. This should make symbol
7103 completion (TAB on the command line) much faster. It's not as fast as
7104 we'd like, but it's significantly faster than gdb-4.6.
7108 A new user controllable variable 'call_scratch_address' can
7109 specify the location of a scratch area to be used when GDB
7110 calls a function in the target. This is necessary because the
7111 usual method of putting the scratch area on the stack does not work
7112 in systems that have separate instruction and data spaces.
7114 We integrated changes to support the 29k UDI (Universal Debugger
7115 Interface), but discovered at the last minute that we didn't have all
7116 of the appropriate copyright paperwork. We are working with AMD to
7117 resolve this, and hope to have it available soon.
7121 We have sped up the remote serial line protocol, especially for targets
7122 with lots of registers. It now supports a new `expedited status' ('T')
7123 message which can be used in place of the existing 'S' status message.
7124 This allows the remote stub to send only the registers that GDB
7125 needs to make a quick decision about single-stepping or conditional
7126 breakpoints, eliminating the need to fetch the entire register set for
7127 each instruction being stepped through.
7129 The GDB remote serial protocol now implements a write-through cache for
7130 registers, only re-reading the registers if the target has run.
7132 There is also a new remote serial stub for SPARC processors. You can
7133 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7134 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7135 processor with a serial port.
7139 Configure.in files have become much easier to read and modify. A new
7140 `table driven' format makes it more obvious what configurations are
7141 supported, and what files each one uses.
7145 There is a new opcodes library which will eventually contain all of the
7146 disassembly routines and opcode tables. At present, it only contains
7147 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7148 disassembler (binutils/objdump) to share these routines.
7150 The libiberty library is now copylefted under the GNU Library General
7151 Public License. This allows more liberal use, and was done so libg++
7152 can use it. This makes no difference to GDB, since the Library License
7153 grants all the rights from the General Public License.
7157 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7158 reference to the stabs symbol info used by the debugger. It is (as far
7159 as we know) the only published document on this fascinating topic. We
7160 encourage you to read it, compare it to the stabs information on your
7161 system, and send improvements on the document in general (to
7162 bug-gdb@prep.ai.mit.edu).
7164 And, of course, many bugs have been fixed.
7167 *** Changes in GDB-4.6:
7169 * Better support for C++ function names
7171 GDB now accepts as input the "demangled form" of C++ overloaded function
7172 names and member function names, and can do command completion on such names
7173 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7174 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7175 Make use of command completion, it is your friend.
7177 GDB also now accepts a variety of C++ mangled symbol formats. They are
7178 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7179 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7180 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7181 for the list of formats.
7183 * G++ symbol mangling problem
7185 Recent versions of gcc have a bug in how they emit debugging information for
7186 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7187 directory) can be applied to gcc to fix the problem. Alternatively, if you
7188 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7189 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7190 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7193 * New 'maintenance' command
7195 All of the commands related to hacking GDB internals have been moved out of
7196 the main command set, and now live behind the 'maintenance' command. This
7197 can also be abbreviated as 'mt'. The following changes were made:
7199 dump-me -> maintenance dump-me
7200 info all-breakpoints -> maintenance info breakpoints
7201 printmsyms -> maintenance print msyms
7202 printobjfiles -> maintenance print objfiles
7203 printpsyms -> maintenance print psymbols
7204 printsyms -> maintenance print symbols
7206 The following commands are new:
7208 maintenance demangle Call internal GDB demangler routine to
7209 demangle a C++ link name and prints the result.
7210 maintenance print type Print a type chain for a given symbol
7212 * Change to .gdbinit file processing
7214 We now read the $HOME/.gdbinit file before processing the argv arguments
7215 (e.g. reading symbol files or core files). This allows global parameters to
7216 be set, which will apply during the symbol reading. The ./.gdbinit is still
7217 read after argv processing.
7219 * New hosts supported
7221 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7223 GNU/Linux support i386-unknown-linux or linux
7225 We are also including code to support the HP/PA running BSD and HPUX. This
7226 is almost guaranteed not to work, as we didn't have time to test or build it
7227 for this release. We are including it so that the more adventurous (or
7228 masochistic) of you can play with it. We also had major problems with the
7229 fact that the compiler that we got from HP doesn't support the -g option.
7232 * New targets supported
7234 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7236 * More smarts about finding #include files
7238 GDB now remembers the compilation directory for all include files, and for
7239 all files from which C is generated (like yacc and lex sources). This
7240 greatly improves GDB's ability to find yacc/lex sources, and include files,
7241 especially if you are debugging your program from a directory different from
7242 the one that contains your sources.
7244 We also fixed a bug which caused difficulty with listing and setting
7245 breakpoints in include files which contain C code. (In the past, you had to
7246 try twice in order to list an include file that you hadn't looked at before.)
7248 * Interesting infernals change
7250 GDB now deals with arbitrary numbers of sections, where the symbols for each
7251 section must be relocated relative to that section's landing place in the
7252 target's address space. This work was needed to support ELF with embedded
7253 stabs used by Solaris-2.0.
7255 * Bug fixes (of course!)
7257 There have been loads of fixes for the following things:
7258 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7259 i960, stabs, DOS(GO32), procfs, etc...
7261 See the ChangeLog for details.
7263 *** Changes in GDB-4.5:
7265 * New machines supported (host and target)
7267 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7269 SGI Irix-4.x mips-sgi-irix4 or iris4
7271 * New malloc package
7273 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7274 Mmalloc is capable of handling mutiple heaps of memory. It is also
7275 capable of saving a heap to a file, and then mapping it back in later.
7276 This can be used to greatly speedup the startup of GDB by using a
7277 pre-parsed symbol table which lives in a mmalloc managed heap. For
7278 more details, please read mmalloc/mmalloc.texi.
7282 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7283 'help info proc' for details.
7285 * MIPS ecoff symbol table format
7287 The code that reads MIPS symbol table format is now supported on all hosts.
7288 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7291 * File name changes for MS-DOS
7293 Many files in the config directories have been renamed to make it easier to
7294 support GDB on MS-DOSe systems (which have very restrictive file name
7295 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7296 environment) is close to working but has some remaining problems. Note
7297 that debugging of DOS programs is not supported, due to limitations
7298 in the ``operating system'', but it can be used to host cross-debugging.
7300 * Cross byte order fixes
7302 Many fixes have been made to support cross debugging of Sparc and MIPS
7303 targets from hosts whose byte order differs.
7305 * New -mapped and -readnow options
7307 If memory-mapped files are available on your system through the 'mmap'
7308 system call, you can use the -mapped option on the `file' or
7309 `symbol-file' commands to cause GDB to write the symbols from your
7310 program into a reusable file. If the program you are debugging is
7311 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7312 Future GDB debugging sessions will notice the presence of this file,
7313 and will quickly map in symbol information from it, rather than reading
7314 the symbol table from the executable program. Using the '-mapped'
7315 option in a GDB `file' or `symbol-file' command has the same effect as
7316 starting GDB with the '-mapped' command-line option.
7318 You can cause GDB to read the entire symbol table immediately by using
7319 the '-readnow' option with any of the commands that load symbol table
7320 information (or on the GDB command line). This makes the command
7321 slower, but makes future operations faster.
7323 The -mapped and -readnow options are typically combined in order to
7324 build a `fred.syms' file that contains complete symbol information.
7325 A simple GDB invocation to do nothing but build a `.syms' file for future
7328 gdb -batch -nx -mapped -readnow programname
7330 The `.syms' file is specific to the host machine on which GDB is run.
7331 It holds an exact image of GDB's internal symbol table. It cannot be
7332 shared across multiple host platforms.
7334 * longjmp() handling
7336 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7337 siglongjmp() without losing control. This feature has not yet been ported to
7338 all systems. It currently works on many 386 platforms, all MIPS-based
7339 platforms (SGI, DECstation, etc), and Sun3/4.
7343 Preliminary work has been put in to support the new Solaris OS from Sun. At
7344 this time, it can control and debug processes, but it is not capable of
7349 As always, many many bug fixes. The major areas were with g++, and mipsread.
7350 People using the MIPS-based platforms should experience fewer mysterious
7351 crashes and trashed symbol tables.
7353 *** Changes in GDB-4.4:
7355 * New machines supported (host and target)
7357 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7359 BSD Reno on Vax vax-dec-bsd
7360 Ultrix on Vax vax-dec-ultrix
7362 * New machines supported (target)
7364 AMD 29000 embedded, using EBMON a29k-none-none
7368 GDB continues to improve its handling of C++. `References' work better.
7369 The demangler has also been improved, and now deals with symbols mangled as
7370 per the Annotated C++ Reference Guide.
7372 GDB also now handles `stabs' symbol information embedded in MIPS
7373 `ecoff' symbol tables. Since the ecoff format was not easily
7374 extensible to handle new languages such as C++, this appeared to be a
7375 good way to put C++ debugging info into MIPS binaries. This option
7376 will be supported in the GNU C compiler, version 2, when it is
7379 * New features for SVR4
7381 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7382 shared libraries. Debugging dynamically linked programs should present
7383 only minor differences from debugging statically linked programs.
7385 The `info proc' command will print out information about any process
7386 on an SVR4 system (including the one you are debugging). At the moment,
7387 it prints the address mappings of the process.
7389 If you bring up GDB on another SVR4 system, please send mail to
7390 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7392 * Better dynamic linking support in SunOS
7394 Reading symbols from shared libraries which contain debugging symbols
7395 now works properly. However, there remain issues such as automatic
7396 skipping of `transfer vector' code during function calls, which
7397 make it harder to debug code in a shared library, than to debug the
7398 same code linked statically.
7402 GDB is now using the latest `getopt' routines from the FSF. This
7403 version accepts the -- prefix for options with long names. GDB will
7404 continue to accept the old forms (-option and +option) as well.
7405 Various single letter abbreviations for options have been explicity
7406 added to the option table so that they won't get overshadowed in the
7407 future by other options that begin with the same letter.
7411 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7412 Many assorted bugs have been handled. Many more remain to be handled.
7413 See the various ChangeLog files (primarily in gdb and bfd) for details.
7416 *** Changes in GDB-4.3:
7418 * New machines supported (host and target)
7420 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7421 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7422 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7424 * Almost SCO Unix support
7426 We had hoped to support:
7427 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7428 (except for core file support), but we discovered very late in the release
7429 that it has problems with process groups that render gdb unusable. Sorry
7430 about that. I encourage people to fix it and post the fixes.
7432 * Preliminary ELF and DWARF support
7434 GDB can read ELF object files on System V Release 4, and can handle
7435 debugging records for C, in DWARF format, in ELF files. This support
7436 is preliminary. If you bring up GDB on another SVR4 system, please
7437 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7442 GDB now uses the latest `readline' library. One user-visible change
7443 is that two tabs will list possible command completions, which previously
7444 required typing M-? (meta-question mark, or ESC ?).
7448 The `stepi' bug that many of you noticed has been squashed.
7449 Many bugs in C++ have been handled. Many more remain to be handled.
7450 See the various ChangeLog files (primarily in gdb and bfd) for details.
7452 * State of the MIPS world (in case you wondered):
7454 GDB can understand the symbol tables emitted by the compilers
7455 supplied by most vendors of MIPS-based machines, including DEC. These
7456 symbol tables are in a format that essentially nobody else uses.
7458 Some versions of gcc come with an assembler post-processor called
7459 mips-tfile. This program is required if you want to do source-level
7460 debugging of gcc-compiled programs. I believe FSF does not ship
7461 mips-tfile with gcc version 1, but it will eventually come with gcc
7464 Debugging of g++ output remains a problem. g++ version 1.xx does not
7465 really support it at all. (If you're lucky, you should be able to get
7466 line numbers and stack traces to work, but no parameters or local
7467 variables.) With some work it should be possible to improve the
7470 When gcc version 2 is released, you will have somewhat better luck.
7471 However, even then you will get confusing results for inheritance and
7474 We will eventually provide full debugging of g++ output on
7475 DECstations. This will probably involve some kind of stabs-in-ecoff
7476 encapulation, but the details have not been worked out yet.
7479 *** Changes in GDB-4.2:
7481 * Improved configuration
7483 Only one copy of `configure' exists now, and it is not self-modifying.
7484 Porting BFD is simpler.
7488 The `step' and `next' commands now only stop at the first instruction
7489 of a source line. This prevents the multiple stops that used to occur
7490 in switch statements, for-loops, etc. `Step' continues to stop if a
7491 function that has debugging information is called within the line.
7495 Lots of small bugs fixed. More remain.
7497 * New host supported (not target)
7499 Intel 386 PC clone running Mach i386-none-mach
7502 *** Changes in GDB-4.1:
7504 * Multiple source language support
7506 GDB now has internal scaffolding to handle several source languages.
7507 It determines the type of each source file from its filename extension,
7508 and will switch expression parsing and number formatting to match the
7509 language of the function in the currently selected stack frame.
7510 You can also specifically set the language to be used, with
7511 `set language c' or `set language modula-2'.
7515 GDB now has preliminary support for the GNU Modula-2 compiler,
7516 currently under development at the State University of New York at
7517 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7518 continue through the fall of 1991 and into 1992.
7520 Other Modula-2 compilers are currently not supported, and attempting to
7521 debug programs compiled with them will likely result in an error as the
7522 symbol table is read. Feel free to work on it, though!
7524 There are hooks in GDB for strict type checking and range checking,
7525 in the `Modula-2 philosophy', but they do not currently work.
7529 GDB can now write to executable and core files (e.g. patch
7530 a variable's value). You must turn this switch on, specify
7531 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7532 by assigning a new value to a variable. Modifications take
7535 * Automatic SunOS shared library reading
7537 When you run your program, GDB automatically determines where its
7538 shared libraries (if any) have been loaded, and reads their symbols.
7539 The `share' command is no longer needed. This also works when
7540 examining core files.
7544 You can specify the number of lines that the `list' command shows.
7547 * New machines supported (host and target)
7549 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7550 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7551 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7553 * New hosts supported (not targets)
7555 IBM RT/PC: romp-ibm-aix or rtpc
7557 * New targets supported (not hosts)
7559 AMD 29000 embedded with COFF a29k-none-coff
7560 AMD 29000 embedded with a.out a29k-none-aout
7561 Ultracomputer remote kernel debug a29k-nyu-kern
7563 * New remote interfaces
7569 *** Changes in GDB-4.0:
7573 Wide output is wrapped at good places to make the output more readable.
7575 Gdb now supports cross-debugging from a host machine of one type to a
7576 target machine of another type. Communication with the target system
7577 is over serial lines. The ``target'' command handles connecting to the
7578 remote system; the ``load'' command will download a program into the
7579 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7580 also supports debugging of realtime processes running under VxWorks,
7581 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7582 stub on the target system.
7584 New CPUs supported include the AMD 29000 and Intel 960.
7586 GDB now reads object files and symbol tables via a ``binary file''
7587 library, which allows a single copy of GDB to debug programs of multiple
7588 object file types such as a.out and coff.
7590 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7591 refcard.dvi and refcard.ps are available to format it).
7594 * Control-Variable user interface simplified
7596 All variables that control the operation of the debugger can be set
7597 by the ``set'' command, and displayed by the ``show'' command.
7599 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7600 ``Show prompt'' produces the response:
7601 Gdb's prompt is new-gdb=>.
7603 What follows are the NEW set commands. The command ``help set'' will
7604 print a complete list of old and new set commands. ``help set FOO''
7605 will give a longer description of the variable FOO. ``show'' will show
7606 all of the variable descriptions and their current settings.
7608 confirm on/off: Enables warning questions for operations that are
7609 hard to recover from, e.g. rerunning the program while
7610 it is already running. Default is ON.
7612 editing on/off: Enables EMACS style command line editing
7613 of input. Previous lines can be recalled with
7614 control-P, the current line can be edited with control-B,
7615 you can search for commands with control-R, etc.
7618 history filename NAME: NAME is where the gdb command history
7619 will be stored. The default is .gdb_history,
7620 or the value of the environment variable
7623 history size N: The size, in commands, of the command history. The
7624 default is 256, or the value of the environment variable
7627 history save on/off: If this value is set to ON, the history file will
7628 be saved after exiting gdb. If set to OFF, the
7629 file will not be saved. The default is OFF.
7631 history expansion on/off: If this value is set to ON, then csh-like
7632 history expansion will be performed on
7633 command line input. The default is OFF.
7635 radix N: Sets the default radix for input and output. It can be set
7636 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7637 in the current radix, so "set radix 10" is always a no-op.
7639 height N: This integer value is the number of lines on a page. Default
7640 is 24, the current `stty rows'' setting, or the ``li#''
7641 setting from the termcap entry matching the environment
7644 width N: This integer value is the number of characters on a line.
7645 Default is 80, the current `stty cols'' setting, or the ``co#''
7646 setting from the termcap entry matching the environment
7649 Note: ``set screensize'' is obsolete. Use ``set height'' and
7650 ``set width'' instead.
7652 print address on/off: Print memory addresses in various command displays,
7653 such as stack traces and structure values. Gdb looks
7654 more ``symbolic'' if you turn this off; it looks more
7655 ``machine level'' with it on. Default is ON.
7657 print array on/off: Prettyprint arrays. New convenient format! Default
7660 print demangle on/off: Print C++ symbols in "source" form if on,
7663 print asm-demangle on/off: Same, for assembler level printouts
7666 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7669 * Support for Epoch Environment.
7671 The epoch environment is a version of Emacs v18 with windowing. One
7672 new command, ``inspect'', is identical to ``print'', except that if you
7673 are running in the epoch environment, the value is printed in its own
7677 * Support for Shared Libraries
7679 GDB can now debug programs and core files that use SunOS shared libraries.
7680 Symbols from a shared library cannot be referenced
7681 before the shared library has been linked with the program (this
7682 happens after you type ``run'' and before the function main() is entered).
7683 At any time after this linking (including when examining core files
7684 from dynamically linked programs), gdb reads the symbols from each
7685 shared library when you type the ``sharedlibrary'' command.
7686 It can be abbreviated ``share''.
7688 sharedlibrary REGEXP: Load shared object library symbols for files
7689 matching a unix regular expression. No argument
7690 indicates to load symbols for all shared libraries.
7692 info sharedlibrary: Status of loaded shared libraries.
7697 A watchpoint stops execution of a program whenever the value of an
7698 expression changes. Checking for this slows down execution
7699 tremendously whenever you are in the scope of the expression, but is
7700 quite useful for catching tough ``bit-spreader'' or pointer misuse
7701 problems. Some machines such as the 386 have hardware for doing this
7702 more quickly, and future versions of gdb will use this hardware.
7704 watch EXP: Set a watchpoint (breakpoint) for an expression.
7706 info watchpoints: Information about your watchpoints.
7708 delete N: Deletes watchpoint number N (same as breakpoints).
7709 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7710 enable N: Re-enables watchpoint number N (same as breakpoints).
7713 * C++ multiple inheritance
7715 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7718 * C++ exception handling
7720 Gdb now supports limited C++ exception handling. Besides the existing
7721 ability to breakpoint on an exception handler, gdb can breakpoint on
7722 the raising of an exception (before the stack is peeled back to the
7725 catch FOO: If there is a FOO exception handler in the dynamic scope,
7726 set a breakpoint to catch exceptions which may be raised there.
7727 Multiple exceptions (``catch foo bar baz'') may be caught.
7729 info catch: Lists all exceptions which may be caught in the
7730 current stack frame.
7733 * Minor command changes
7735 The command ``call func (arg, arg, ...)'' now acts like the print
7736 command, except it does not print or save a value if the function's result
7737 is void. This is similar to dbx usage.
7739 The ``up'' and ``down'' commands now always print the frame they end up
7740 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7741 frames without printing.
7743 * New directory command
7745 'dir' now adds directories to the FRONT of the source search path.
7746 The path starts off empty. Source files that contain debug information
7747 about the directory in which they were compiled can be found even
7748 with an empty path; Sun CC and GCC include this information. If GDB can't
7749 find your source file in the current directory, type "dir .".
7751 * Configuring GDB for compilation
7753 For normal use, type ``./configure host''. See README or gdb.texinfo
7756 GDB now handles cross debugging. If you are remotely debugging between
7757 two different machines, type ``./configure host -target=targ''.
7758 Host is the machine where GDB will run; targ is the machine
7759 where the program that you are debugging will run.