1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * Debugging MS-Windows processes now sets $_exitsignal when the
7 inferior is terminated by a signal, instead of setting $_exitcode.
9 * Multithreaded symbol loading has now been enabled by default on systems
10 that support it (see entry for GDB 9, below), providing faster
11 performance for programs with many symbols.
15 * 'thread-exited' event is now available in the annotations interface.
17 * New built-in convenience variables $_gdb_major and $_gdb_minor
18 provide the GDB version. They are handy for conditionally using
19 features available only in or since specific GDB versions, in
20 scripts that should work error-free with many different versions,
21 such as in system-wide init files.
23 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
24 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
25 of the GDB settings and the GDB maintenance settings. They are handy
26 for changing the logic of user defined commands depending on the
29 * GDB now supports Thread Local Storage (TLS) variables on several
30 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
31 architectures require kernel changes. TLS is not yet supported for
32 amd64 and i386 process core dumps.
34 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
35 addresses that required unmasking are shown in the backtrace with the
38 * Two new convenience functions $_cimag and $_creal that extract the
39 imaginary and real parts respectively from complex numbers.
41 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
42 provide the exitcode or exit status of the shell commands launched by
43 GDB commands such as "shell", "pipe" and "make".
45 * The command define-prefix can now define user defined prefix commands.
46 User defined commands can now be defined using these user defined prefix
49 * Command names can now use the . character.
51 * The RX port now supports XML target descriptions.
53 * GDB now shows the Ada task names at more places, e.g. in task switching
56 * GDB can now be compiled with Python 3 on Windows.
58 * New convenience variable $_ada_exception holds the address of the
59 Ada exception being thrown. This is set by Ada-related catchpoints.
61 * GDB can now place breakpoints on nested functions and subroutines in
62 Fortran code. The '::' operator can be used between parent and
63 child scopes when placing breakpoints, for example:
65 (gdb) break outer_function::inner_function
67 The 'outer_function::' prefix is only needed if 'inner_function' is
68 not visible in the current scope.
70 * In addition to the system-wide gdbinit file, if configured with
71 --with-system-gdbinit-dir, GDB will now also load files in that directory
72 as system gdbinit files, unless the -nx or -n flag is provided. Files
73 with extensions .gdb, .py and .scm are supported as long as GDB was
74 compiled with support for that language.
76 * GDB now supports multithreaded symbol loading for higher performance.
77 This feature is still in testing, so it is disabled by default. You
78 can turn it on using 'maint set worker-threads unlimited'.
82 ** The gdb.Value type has a new method 'format_string' which returns a
83 string representing the value. The formatting is controlled by the
84 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
85 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
86 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
88 ** gdb.Type has a new property 'objfile' which returns the objfile the
91 ** The frame information printed by the python frame filtering code
92 is now consistent with what the 'backtrace' command prints when
93 there are no filters, or when the 'backtrace' '-no-filters' option
96 ** The new function gdb.lookup_static_symbol can be used to look up
97 symbols with static linkage.
99 ** The new function gdb.lookup_static_symbols can be used to look up
100 all static symbols with static linkage.
102 ** gdb.Objfile has new methods 'lookup_global_symbol' and
103 'lookup_static_symbol' to lookup a symbol from this objfile only.
105 ** gdb.Block now supports the dictionary syntax for accessing symbols in
106 this block (e.g. block['local_variable']).
110 | [COMMAND] | SHELL_COMMAND
111 | -d DELIM COMMAND DELIM SHELL_COMMAND
112 pipe [COMMAND] | SHELL_COMMAND
113 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
114 Executes COMMAND and sends its output to SHELL_COMMAND.
115 With no COMMAND, repeat the last executed command
116 and send its output to SHELL_COMMAND.
118 define-prefix COMMAND
119 Define or mark a command as a user-defined prefix command.
121 with SETTING [VALUE] [-- COMMAND]
122 w SETTING [VALUE] [-- COMMAND]
123 Temporarily set SETTING, run COMMAND, and restore SETTING.
124 Usage: with SETTING -- COMMAND
125 With no COMMAND, repeats the last executed command.
126 SETTING is any GDB setting you can change with the "set"
127 subcommands. For example, 'with language c -- print someobj'
128 temporarily switches to the C language in order to print someobj.
129 Settings can be combined: 'w lang c -- w print elements unlimited --
130 usercmd' switches to the C language and runs usercmd with no limit
131 of array elements to print.
133 maint with SETTING [VALUE] [-- COMMAND]
134 Like "with", but works with "maintenance set" settings.
136 set may-call-functions [on|off]
137 show may-call-functions
138 This controls whether GDB will attempt to call functions in
139 the program, such as with expressions in the print command. It
140 defaults to on. Calling functions in the program being debugged
141 can have undesired side effects. It is now possible to forbid
142 such function calls. If function calls are forbidden, GDB will throw
143 an error when a command (such as print expression) calls a function
146 set print finish [on|off]
148 This controls whether the `finish' command will display the value
149 that is returned by the current function. When `off', the value is
150 still entered into the value history, but it is not printed. The
155 Allows deeply nested structures to be simplified when printing by
156 replacing deeply nested parts (beyond the max-depth) with ellipses.
157 The default max-depth is 20, but this can be set to unlimited to get
158 the old behavior back.
160 set print raw-values [on|off]
161 show print raw-values
162 By default, GDB applies the enabled pretty printers when printing a
163 value. This allows to ignore the enabled pretty printers for a series
164 of commands. The default is 'off'.
166 set logging debugredirect [on|off]
167 By default, GDB debug output will go to both the terminal and the logfile.
168 Set if you want debug output to go only to the log file.
170 set style title foreground COLOR
171 set style title background COLOR
172 set style title intensity VALUE
173 Control the styling of titles.
175 set style highlight foreground COLOR
176 set style highlight background COLOR
177 set style highlight intensity VALUE
178 Control the styling of highlightings.
180 maint set worker-threads
181 maint show worker-threads
182 Control the number of worker threads that can be used by GDB. The
183 default is 0. "unlimited" lets GDB choose a number that is
184 reasonable. Currently worker threads are only used when demangling
185 the names of linker symbols.
187 set style tui-border foreground COLOR
188 set style tui-border background COLOR
189 Control the styling of TUI borders.
191 set style tui-active-border foreground COLOR
192 set style tui-active-border background COLOR
193 Control the styling of the active TUI border.
195 maint set test-settings KIND
196 maint show test-settings KIND
197 A set of commands used by the testsuite for exercising the settings
200 maint set tui-resize-message [on|off]
201 maint show tui-resize-message
202 Control whether GDB prints a message each time the terminal is
203 resized when in TUI mode. This is primarily useful for testing the
206 set print frame-info [short-location|location|location-and-address
207 |source-and-location|source-line|auto]
208 show print frame-info
209 This controls what frame information is printed by the commands printing
210 a frame. This setting will e.g. influence the behaviour of 'backtrace',
211 'frame', 'stepi'. The python frame filtering also respect this setting.
212 The 'backtrace' '-frame-info' option can override this global setting.
214 set tui compact-source
215 show tui compact-source
217 Enable the "compact" display mode for the TUI source window. The
218 compact display uses only as much space as is needed for the line
219 numbers in the current file, and only a single space to separate the
220 line numbers from the source.
222 info modules [-q] [REGEXP]
223 Return a list of Fortran modules matching REGEXP, or all modules if
226 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
227 Return a list of functions within all modules, grouped by module.
228 The list of functions can be restricted with the optional regular
229 expressions. MODULE_REGEXP matches against the module name,
230 TYPE_REGEXP matches against the function type signature, and REGEXP
231 matches against the function name.
233 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
234 Return a list of variables within all modules, grouped by module.
235 The list of variables can be restricted with the optional regular
236 expressions. MODULE_REGEXP matches against the module name,
237 TYPE_REGEXP matches against the variable type, and REGEXP matches
238 against the variable name.
240 set debug remote-packet-max-chars
241 show debug remote-packet-max-chars
242 Controls the number of characters to output in a remote packet when using
244 The default is 512 bytes.
249 The "help" command uses the title style to enhance the
250 readibility of its output by styling the classes and
254 Similarly to "help", the "apropos" command also uses the
255 title style for the command names. "apropos" accepts now
256 a flag "-v" (verbose) to show the full documentation
257 of matching commands and to use the highlight style to mark
258 the documentation parts matching REGEXP.
262 The GDB printf and eval commands can now print C-style and Ada-style
263 string convenience variables without calling functions in the program.
264 This allows to do formatted printing of strings without having
265 a running inferior, or when debugging a core dump.
267 info sources [-dirname | -basename] [--] [REGEXP]
268 This command has now optional arguments to only print the files
269 whose names match REGEXP. The arguments -dirname and -basename
270 allow to restrict matching respectively to the dirname and basename
274 The "show style" and its subcommands are now styling
275 a style name in their output using its own style, to help
276 the user visualize the different styles.
278 set print frame-arguments
279 The new value 'presence' indicates to only indicate the presence of
280 arguments using ..., instead of printing argument names and values.
282 set print raw-frame-arguments
283 show print raw-frame-arguments
285 These commands replace the similarly-named "set/show print raw
286 frame-arguments" commands (now with a dash instead of a space). The
287 old commands are now deprecated and may be removed in a future
290 maint test-options require-delimiter
291 maint test-options unknown-is-error
292 maint test-options unknown-is-operand
293 maint show test-options-completion-result
294 Commands used by the testsuite to validate the command options
297 focus, winheight, +, -, >, <
298 These commands are now case-sensitive.
300 * New command options, command completion
302 GDB now has a standard infrastructure to support dash-style command
303 options ('-OPT'). One benefit is that commands that use it can
304 easily support completion of command line arguments. Try "CMD
305 -[TAB]" or "help CMD" to find options supported by a command. Over
306 time, we intend to migrate most commands to this infrastructure. A
307 number of commands got support for new command options in this
310 ** The "print" and "compile print" commands now support a number of
311 options that allow overriding relevant global print settings as
312 set by "set print" subcommands:
316 -array-indexes [on|off]
317 -elements NUMBER|unlimited
322 -repeats NUMBER|unlimited
323 -static-members [on|off]
328 Note that because the "print"/"compile print" commands accept
329 arbitrary expressions which may look like options (including
330 abbreviations), if you specify any command option, then you must
331 use a double dash ("--") to mark the end of argument processing.
333 ** The "backtrace" command now supports a number of options that
334 allow overriding relevant global print settings as set by "set
335 backtrace" and "set print" subcommands:
337 -entry-values no|only|preferred|if-needed|both|compact|default
338 -frame-arguments all|scalars|none
339 -raw-frame-arguments [on|off]
340 -frame-info auto|source-line|location|source-and-location
341 |location-and-address|short-location
345 In addition, the full/no-filters/hide qualifiers are now also
346 exposed as command options too:
352 ** The "frame apply", "tfaas" and "faas" commands similarly now
353 support the following options:
358 ** The new "info sources" options -dirname and -basename options
359 are using the standard '-OPT' infrastructure.
361 All options above can also be abbreviated. The argument of boolean
362 (on/off) options can be 0/1 too, and also the argument is assumed
363 "on" if omitted. This allows writing compact command invocations,
366 (gdb) p -ra -p -o 0 -- *myptr
368 The above is equivalent to:
370 (gdb) print -raw-values -pretty -object off -- *myptr
372 ** The "info types" command now supports the '-q' flag to disable
373 printing of some header information in a similar fashion to "info
374 variables" and "info functions".
376 ** The "info variables", "info functions", and "whereis" commands
377 now take a '-n' flag that excludes non-debug symbols (symbols
378 from the symbol table, not from the debug info such as DWARF)
381 * Completion improvements
383 ** GDB can now complete the options of the "thread apply all" and
384 "taas" commands, and their "-ascending" option can now be
387 ** GDB can now complete the options of the "info threads", "info
388 functions", "info variables", "info locals", and "info args"
391 ** GDB can now complete the options of the "compile file" and
392 "compile code" commands. The "compile file" command now
393 completes on filenames.
395 ** GDB can now complete the backtrace command's
396 "full/no-filters/hide" qualifiers.
398 * In settings, you can now abbreviate "unlimited".
400 E.g., "set print elements u" is now equivalent to "set print
406 This lists all the possible completions for the rest of the line, if it
407 were to be given as a command itself. This is intended for use by MI
408 frontends in cases when separate CLI and MI channels cannot be used.
410 -catch-throw, -catch-rethrow, and -catch-catch
411 These can be used to catch C++ exceptions in a similar fashion to
412 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
414 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
415 These commands are the MI equivalent of the CLI commands 'info
416 functions', 'info types', and 'info variables' respectively.
418 -symbol-info-modules, this is the MI equivalent of the CLI 'info
421 -symbol-info-module-functions and -symbol-info-module-variables.
422 These commands are the MI equivalent of the CLI commands 'info
423 module functions' and 'info module variables'.
427 ** The default version of the MI interpreter is now 3 (-i=mi3).
429 ** The output of information about multi-location breakpoints (which is
430 syntactically incorrect in MI 2) has changed in MI 3. This affects
431 the following commands and events:
435 - =breakpoint-created
436 - =breakpoint-modified
438 The -fix-multi-location-breakpoint-output command can be used to enable
439 this behavior with previous MI versions.
441 ** Backtraces and frames include a new optional field addr_flags which is
442 given after the addr field. On AArch64 this contains PAC if the address
443 has been masked in the frame. On all other targets the field is not
448 The testsuite now creates the files gdb.cmd (containing the arguments
449 used to launch GDB) and gdb.in (containing all the commands sent to
450 GDB) in the output directory for each test script. Multiple invocations
451 are appended with .1, .2, .3 etc.
453 * Building GDB and GDBserver now requires GNU make >= 3.82.
455 Using another implementation of the make program or an earlier version of
456 GNU make to build GDB or GDBserver is not supported.
458 * Building GDB now requires GNU readline >= 7.0.
460 GDB now bundles GNU readline 8.0, but if you choose to use
461 --with-system-readline, only readline >= 7.0 can be used.
463 * The TUI SingleKey keymap is now named "SingleKey". This can be used
464 from .inputrc to bind keys in this keymap. This feature is only
465 available when gdb is built against GNU readline 8.0 or later.
467 * Removed targets and native configurations
469 GDB no longer supports debugging the Cell Broadband Engine. This includes
470 both debugging standalone Cell/B.E. SPU applications and integrated debugging
471 of Cell/B.E. applications that use both the PPU and SPU architectures.
477 * Removed targets and native configurations
479 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
482 *** Changes in GDB 8.3
484 * GDB and GDBserver now support access to additional registers on
485 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
488 * GDB now has experimental support for the compilation and injection of
489 C++ source code into the inferior. This beta release does not include
490 support for several language features, such as templates, constructors,
493 This feature requires GCC 7.1 or higher built with libcp1.so
496 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
497 can be passed using the '[ADDRESS]:PORT' notation, or the regular
498 'ADDRESS:PORT' method.
500 * DWARF index cache: GDB can now automatically save indices of DWARF
501 symbols on disk to speed up further loading of the same binaries.
503 * Ada task switching is now supported on aarch64-elf targets when
504 debugging a program using the Ravenscar Profile. For more information,
505 see the "Tasking Support when using the Ravenscar Profile" section
506 in the GDB user manual.
508 * GDB in batch mode now exits with status 1 if the last command to be
511 * The RISC-V target now supports target descriptions.
513 * System call catchpoints now support system call aliases on FreeBSD.
514 When the ABI of a system call changes in FreeBSD, this is
515 implemented by leaving a compatibility system call using the old ABI
516 at the existing number and allocating a new system call number for
517 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
518 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
519 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
520 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
521 so that a system call catchpoint for the 'kevent' system call will
522 catch invocations of both the 'kevent' and 'freebsd11_kevent'
523 binaries. This ensures that 'kevent' system calls are caught for
524 binaries using either the old or new ABIs.
526 * Terminal styling is now available for the CLI and the TUI. GNU
527 Source Highlight can additionally be used to provide styling of
528 source code snippets. See the "set style" commands, below, for more
531 * Removed support for old demangling styles arm, edg, gnu, hp and
536 set debug compile-cplus-types
537 show debug compile-cplus-types
538 Control the display of debug output about type conversion in the
539 C++ compile feature. Commands have no effect while compiliong
544 Control whether debug output about files/functions skipping is
547 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
548 Apply a command to some frames.
549 FLAG arguments allow to control what output to produce and how to handle
550 errors raised when applying COMMAND to a frame.
553 Apply a command to all threads (ignoring errors and empty output).
554 Shortcut for 'thread apply all -s COMMAND'.
557 Apply a command to all frames (ignoring errors and empty output).
558 Shortcut for 'frame apply all -s COMMAND'.
561 Apply a command to all frames of all threads (ignoring errors and empty
563 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
565 maint set dwarf unwinders (on|off)
566 maint show dwarf unwinders
567 Control whether DWARF unwinders can be used.
570 Display a list of open files for a process.
574 Changes to the "frame", "select-frame", and "info frame" CLI commands.
575 These commands all now take a frame specification which
576 is either a frame level, or one of the keywords 'level', 'address',
577 'function', or 'view' followed by a parameter. Selecting a frame by
578 address, or viewing a frame outside the current backtrace now
579 requires the use of a keyword. Selecting a frame by level is
580 unchanged. The MI comment "-stack-select-frame" is unchanged.
582 target remote FILENAME
583 target extended-remote FILENAME
584 If FILENAME is a Unix domain socket, GDB will attempt to connect
585 to this socket instead of opening FILENAME as a character device.
587 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
588 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
589 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
590 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
591 These commands can now print only the searched entities
592 matching the provided regexp(s), giving a condition
593 on the entity names or entity types. The flag -q disables
594 printing headers or informations messages.
600 These commands now determine the syntax for the shown entities
601 according to the language chosen by `set language'. In particular,
602 `set language auto' means to automatically choose the language of
605 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
606 The 'thread apply' command accepts new FLAG arguments.
607 FLAG arguments allow to control what output to produce and how to handle
608 errors raised when applying COMMAND to a thread.
610 set tui tab-width NCHARS
611 show tui tab-width NCHARS
612 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
614 set style enabled [on|off]
616 Enable or disable terminal styling. Styling is enabled by default
617 on most hosts, but disabled by default when in batch mode.
619 set style sources [on|off]
621 Enable or disable source code styling. Source code styling is
622 enabled by default, but only takes effect if styling in general is
623 enabled, and if GDB was linked with GNU Source Highlight.
625 set style filename foreground COLOR
626 set style filename background COLOR
627 set style filename intensity VALUE
628 Control the styling of file names.
630 set style function foreground COLOR
631 set style function background COLOR
632 set style function intensity VALUE
633 Control the styling of function names.
635 set style variable foreground COLOR
636 set style variable background COLOR
637 set style variable intensity VALUE
638 Control the styling of variable names.
640 set style address foreground COLOR
641 set style address background COLOR
642 set style address intensity VALUE
643 Control the styling of addresses.
647 ** The '-data-disassemble' MI command now accepts an '-a' option to
648 disassemble the whole function surrounding the given program
649 counter value or function name. Support for this feature can be
650 verified by using the "-list-features" command, which should
651 contain "data-disassemble-a-option".
653 ** Command responses and notifications that include a frame now include
654 the frame's architecture in a new "arch" attribute.
656 * New native configurations
658 GNU/Linux/RISC-V riscv*-*-linux*
659 FreeBSD/riscv riscv*-*-freebsd*
663 GNU/Linux/RISC-V riscv*-*-linux*
665 CSKY GNU/LINUX csky*-*-linux
666 FreeBSD/riscv riscv*-*-freebsd*
668 GNU/Linux/OpenRISC or1k*-*-linux*
672 GDB no longer supports native debugging on versions of MS-Windows
677 ** GDB no longer supports Python versions less than 2.6.
679 ** The gdb.Inferior type has a new 'progspace' property, which is the program
680 space associated to that inferior.
682 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
683 of objfiles associated to that program space.
685 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
686 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
689 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
690 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
691 correct and did not work properly.
693 ** The gdb.Value type has a new constructor, which is used to construct a
694 gdb.Value from a Python buffer object and a gdb.Type.
700 Enable or disable the undefined behavior sanitizer. This is
701 disabled by default, but passing --enable-ubsan=yes or
702 --enable-ubsan=auto to configure will enable it. Enabling this can
703 cause a performance penalty. The undefined behavior sanitizer was
704 first introduced in GCC 4.9.
706 *** Changes in GDB 8.2
708 * The 'set disassembler-options' command now supports specifying options
711 * The 'symbol-file' command now accepts an '-o' option to add a relative
712 offset to all sections.
714 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
715 a relative offset to all sections, but it allows to override the load
716 address of individual sections using '-s'.
718 * The 'add-symbol-file' command no longer requires the second argument
719 (address of the text section).
721 * The endianness used with the 'set endian auto' mode in the absence of
722 an executable selected for debugging is now the last endianness chosen
723 either by one of the 'set endian big' and 'set endian little' commands
724 or by inferring from the last executable used, rather than the startup
727 * The pager now allows a "c" response, meaning to disable the pager
728 for the rest of the current command.
730 * The commands 'info variables/functions/types' now show the source line
731 numbers of symbol definitions when available.
733 * 'info proc' now works on running processes on FreeBSD systems and core
734 files created on FreeBSD systems.
736 * C expressions can now use _Alignof, and C++ expressions can now use
739 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
740 the vector length while the process is running.
746 Control display of debugging info regarding the FreeBSD native target.
748 set|show varsize-limit
749 This new setting allows the user to control the maximum size of Ada
750 objects being printed when those objects have a variable type,
751 instead of that maximum size being hardcoded to 65536 bytes.
753 set|show record btrace cpu
754 Controls the processor to be used for enabling errata workarounds for
757 maint check libthread-db
758 Run integrity checks on the current inferior's thread debugging
761 maint set check-libthread-db (on|off)
762 maint show check-libthread-db
763 Control whether to run integrity checks on inferior specific thread
764 debugging libraries as they are loaded. The default is not to
769 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
771 ** The commands attached to a breakpoint can be set by assigning to
772 the breakpoint's "commands" field.
774 ** gdb.execute can now execute multi-line gdb commands.
776 ** The new functions gdb.convenience_variable and
777 gdb.set_convenience_variable can be used to get and set the value
778 of convenience variables.
780 ** A gdb.Parameter will no longer print the "set" help text on an
781 ordinary "set"; instead by default a "set" will be silent unless
782 the get_set_string method returns a non-empty string.
786 RiscV ELF riscv*-*-elf
788 * Removed targets and native configurations
790 m88k running OpenBSD m88*-*-openbsd*
791 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
792 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
793 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
795 * Aarch64/Linux hardware watchpoints improvements
797 Hardware watchpoints on unaligned addresses are now properly
798 supported when running Linux kernel 4.10 or higher: read and access
799 watchpoints are no longer spuriously missed, and all watchpoints
800 lengths between 1 and 8 bytes are supported. On older kernels,
801 watchpoints set on unaligned addresses are no longer missed, with
802 the tradeoff that there is a possibility of false hits being
807 --enable-codesign=CERT
808 This can be used to invoke "codesign -s CERT" after building gdb.
809 This option is useful on macOS, where code signing is required for
810 gdb to work properly.
812 --disable-gdbcli has been removed
813 This is now silently accepted, but does nothing.
815 *** Changes in GDB 8.1
817 * GDB now supports dynamically creating arbitrary register groups specified
818 in XML target descriptions. This allows for finer grain grouping of
819 registers on systems with a large amount of registers.
821 * The 'ptype' command now accepts a '/o' flag, which prints the
822 offsets and sizes of fields in a struct, like the pahole(1) tool.
824 * New "--readnever" command line option instructs GDB to not read each
825 symbol file's symbolic debug information. This makes startup faster
826 but at the expense of not being able to perform symbolic debugging.
827 This option is intended for use cases where symbolic debugging will
828 not be used, e.g., when you only need to dump the debuggee's core.
830 * GDB now uses the GNU MPFR library, if available, to emulate target
831 floating-point arithmetic during expression evaluation when the target
832 uses different floating-point formats than the host. At least version
833 3.1 of GNU MPFR is required.
835 * GDB now supports access to the guarded-storage-control registers and the
836 software-based guarded-storage broadcast control registers on IBM z14.
838 * On Unix systems, GDB now supports transmitting environment variables
839 that are to be set or unset to GDBserver. These variables will
840 affect the environment to be passed to the remote inferior.
842 To inform GDB of environment variables that are to be transmitted to
843 GDBserver, use the "set environment" command. Only user set
844 environment variables are sent to GDBserver.
846 To inform GDB of environment variables that are to be unset before
847 the remote inferior is started by the GDBserver, use the "unset
848 environment" command.
850 * Completion improvements
852 ** GDB can now complete function parameters in linespecs and
853 explicit locations without quoting. When setting breakpoints,
854 quoting around functions names to help with TAB-completion is
855 generally no longer necessary. For example, this now completes
858 (gdb) b function(in[TAB]
859 (gdb) b function(int)
861 Related, GDB is no longer confused with completing functions in
862 C++ anonymous namespaces:
865 (gdb) b (anonymous namespace)::[TAB][TAB]
866 (anonymous namespace)::a_function()
867 (anonymous namespace)::b_function()
869 ** GDB now has much improved linespec and explicit locations TAB
870 completion support, that better understands what you're
871 completing and offers better suggestions. For example, GDB no
872 longer offers data symbols as possible completions when you're
873 setting a breakpoint.
875 ** GDB now TAB-completes label symbol names.
877 ** The "complete" command now mimics TAB completion accurately.
879 * New command line options (gcore)
882 Dump all memory mappings.
884 * Breakpoints on C++ functions are now set on all scopes by default
886 By default, breakpoints on functions/methods are now interpreted as
887 specifying all functions with the given name ignoring missing
888 leading scopes (namespaces and classes).
890 For example, assuming a C++ program with symbols named:
895 both commands "break func()" and "break B::func()" set a breakpoint
898 You can use the new flag "-qualified" to override this. This makes
899 GDB interpret the specified function name as a complete
900 fully-qualified name instead. For example, using the same C++
901 program, the "break -q B::func" command sets a breakpoint on
902 "B::func", only. A parameter has been added to the Python
903 gdb.Breakpoint constructor to achieve the same result when creating
904 a breakpoint from Python.
906 * Breakpoints on functions marked with C++ ABI tags
908 GDB can now set breakpoints on functions marked with C++ ABI tags
909 (e.g., [abi:cxx11]). See here for a description of ABI tags:
910 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
912 Functions with a C++11 abi tag are demangled/displayed like this:
914 function[abi:cxx11](int)
917 You can now set a breakpoint on such functions simply as if they had
920 (gdb) b function(int)
922 Or if you need to disambiguate between tags, like:
924 (gdb) b function[abi:other_tag](int)
926 Tab completion was adjusted accordingly as well.
930 ** New events gdb.new_inferior, gdb.inferior_deleted, and
931 gdb.new_thread are emitted. See the manual for further
932 description of these.
934 ** A new function, "gdb.rbreak" has been added to the Python API.
935 This function allows the setting of a large number of breakpoints
936 via a regex pattern in Python. See the manual for further details.
938 ** Python breakpoints can now accept explicit locations. See the
939 manual for a further description of this feature.
942 * New features in the GDB remote stub, GDBserver
944 ** GDBserver is now able to start inferior processes with a
945 specified initial working directory.
947 The user can set the desired working directory to be used from
948 GDB using the new "set cwd" command.
950 ** New "--selftest" command line option runs some GDBserver self
951 tests. These self tests are disabled in releases.
953 ** On Unix systems, GDBserver now does globbing expansion and variable
954 substitution in inferior command line arguments.
956 This is done by starting inferiors using a shell, like GDB does.
957 See "set startup-with-shell" in the user manual for how to disable
958 this from GDB when using "target extended-remote". When using
959 "target remote", you can disable the startup with shell by using the
960 new "--no-startup-with-shell" GDBserver command line option.
962 ** On Unix systems, GDBserver now supports receiving environment
963 variables that are to be set or unset from GDB. These variables
964 will affect the environment to be passed to the inferior.
966 * When catching an Ada exception raised with a message, GDB now prints
967 the message in the catchpoint hit notification. In GDB/MI mode, that
968 information is provided as an extra field named "exception-message"
969 in the *stopped notification.
971 * Trait objects can now be inspected When debugging Rust code. This
972 requires compiler support which will appear in Rust 1.24.
976 QEnvironmentHexEncoded
977 Inform GDBserver of an environment variable that is to be passed to
978 the inferior when starting it.
981 Inform GDBserver of an environment variable that is to be unset
982 before starting the remote inferior.
985 Inform GDBserver that the environment should be reset (i.e.,
986 user-set environment variables should be unset).
989 Indicates whether the inferior must be started with a shell or not.
992 Tell GDBserver that the inferior to be started should use a specific
995 * The "maintenance print c-tdesc" command now takes an optional
996 argument which is the file name of XML target description.
998 * The "maintenance selftest" command now takes an optional argument to
999 filter the tests to be run.
1001 * The "enable", and "disable" commands now accept a range of
1002 breakpoint locations, e.g. "enable 1.3-5".
1007 Set and show the current working directory for the inferior.
1009 set|show compile-gcc
1010 Set and show compilation command used for compiling and injecting code
1011 with the 'compile' commands.
1013 set debug separate-debug-file
1014 show debug separate-debug-file
1015 Control the display of debug output about separate debug file search.
1017 set dump-excluded-mappings
1018 show dump-excluded-mappings
1019 Control whether mappings marked with the VM_DONTDUMP flag should be
1020 dumped when generating a core file.
1022 maint info selftests
1023 List the registered selftests.
1026 Start the debugged program stopping at the first instruction.
1029 Control display of debugging messages related to OpenRISC targets.
1031 set|show print type nested-type-limit
1032 Set and show the limit of nesting level for nested types that the
1033 type printer will show.
1035 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1038 * Safer/improved support for debugging with no debug info
1040 GDB no longer assumes functions with no debug information return
1043 This means that GDB now refuses to call such functions unless you
1044 tell it the function's type, by either casting the call to the
1045 declared return type, or by casting the function to a function
1046 pointer of the right type, and calling that:
1048 (gdb) p getenv ("PATH")
1049 'getenv' has unknown return type; cast the call to its declared return type
1050 (gdb) p (char *) getenv ("PATH")
1051 $1 = 0x7fffffffe "/usr/local/bin:/"...
1052 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1053 $2 = 0x7fffffffe "/usr/local/bin:/"...
1055 Similarly, GDB no longer assumes that global variables with no debug
1056 info have type 'int', and refuses to print the variable's value
1057 unless you tell it the variable's type:
1060 'var' has unknown type; cast it to its declared type
1064 * New native configurations
1066 FreeBSD/aarch64 aarch64*-*-freebsd*
1067 FreeBSD/arm arm*-*-freebsd*
1071 FreeBSD/aarch64 aarch64*-*-freebsd*
1072 FreeBSD/arm arm*-*-freebsd*
1073 OpenRISC ELF or1k*-*-elf
1075 * Removed targets and native configurations
1077 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1079 *** Changes in GDB 8.0
1081 * GDB now supports access to the PKU register on GNU/Linux. The register is
1082 added by the Memory Protection Keys for Userspace feature which will be
1083 available in future Intel CPUs.
1085 * GDB now supports C++11 rvalue references.
1089 ** New functions to start, stop and access a running btrace recording.
1090 ** Rvalue references are now supported in gdb.Type.
1092 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1095 * Building GDB and GDBserver now requires a C++11 compiler.
1097 For example, GCC 4.8 or later.
1099 It is no longer possible to build GDB or GDBserver with a C
1100 compiler. The --disable-build-with-cxx configure option has been
1103 * Building GDB and GDBserver now requires GNU make >= 3.81.
1105 It is no longer supported to build GDB or GDBserver with another
1106 implementation of the make program or an earlier version of GNU make.
1108 * Native debugging on MS-Windows supports command-line redirection
1110 Command-line arguments used for starting programs on MS-Windows can
1111 now include redirection symbols supported by native Windows shells,
1112 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1113 as "run", "start", and "set args", as well as the corresponding MI
1116 * Support for thread names on MS-Windows.
1118 GDB now catches and handles the special exception that programs
1119 running on MS-Windows use to assign names to threads in the
1122 * Support for Java programs compiled with gcj has been removed.
1124 * User commands now accept an unlimited number of arguments.
1125 Previously, only up to 10 was accepted.
1127 * The "eval" command now expands user-defined command arguments.
1129 This makes it easier to process a variable number of arguments:
1134 eval "print $arg%d", $i
1139 * Target descriptions can now describe registers for sparc32 and sparc64.
1141 * GDB now supports DWARF version 5 (debug information format).
1142 Its .debug_names index is not yet supported.
1144 * New native configurations
1146 FreeBSD/mips mips*-*-freebsd
1150 Synopsys ARC arc*-*-elf32
1151 FreeBSD/mips mips*-*-freebsd
1153 * Removed targets and native configurations
1155 Alpha running FreeBSD alpha*-*-freebsd*
1156 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1161 Erases all the flash memory regions reported by the target.
1163 maint print arc arc-instruction address
1164 Print internal disassembler information about instruction at a given address.
1168 set disassembler-options
1169 show disassembler-options
1170 Controls the passing of target specific information to the disassembler.
1171 If it is necessary to specify more than one disassembler option then
1172 multiple options can be placed together into a comma separated list.
1173 The default value is the empty string. Currently, the only supported
1174 targets are ARM, PowerPC and S/390.
1179 Erases all the flash memory regions reported by the target. This is
1180 equivalent to the CLI command flash-erase.
1182 -file-list-shared-libraries
1183 List the shared libraries in the program. This is
1184 equivalent to the CLI command "info shared".
1187 Catchpoints stopping the program when Ada exceptions are
1188 handled. This is equivalent to the CLI command "catch handlers".
1190 *** Changes in GDB 7.12
1192 * GDB and GDBserver now build with a C++ compiler by default.
1194 The --enable-build-with-cxx configure option is now enabled by
1195 default. One must now explicitly configure with
1196 --disable-build-with-cxx in order to build with a C compiler. This
1197 option will be removed in a future release.
1199 * GDBserver now supports recording btrace without maintaining an active
1202 * GDB now supports a negative repeat count in the 'x' command to examine
1203 memory backward from the given address. For example:
1206 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1207 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1208 (gdb) x/-5i 0x0000000000400580
1209 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1210 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1211 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1212 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1213 0x40057b <main(int, char**)+25>:
1214 callq 0x400536 <Func1(int, char const*)>
1216 * Fortran: Support structures with fields of dynamic types and
1217 arrays of dynamic types.
1219 * The symbol dumping maintenance commands have new syntax.
1220 maint print symbols [-pc address] [--] [filename]
1221 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1222 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1223 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1224 maint print msymbols [-objfile objfile] [--] [filename]
1226 * GDB now supports multibit bitfields and enums in target register
1229 * New Python-based convenience function $_as_string(val), which returns
1230 the textual representation of a value. This function is especially
1231 useful to obtain the text label of an enum value.
1233 * Intel MPX bound violation handling.
1235 Segmentation faults caused by a Intel MPX boundary violation
1236 now display the kind of violation (upper or lower), the memory
1237 address accessed and the memory bounds, along with the usual
1238 signal received and code location.
1242 Program received signal SIGSEGV, Segmentation fault
1243 Upper bound violation while accessing address 0x7fffffffc3b3
1244 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1245 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1247 * Rust language support.
1248 GDB now supports debugging programs written in the Rust programming
1249 language. See https://www.rust-lang.org/ for more information about
1252 * Support for running interpreters on specified input/output devices
1254 GDB now supports a new mechanism that allows frontends to provide
1255 fully featured GDB console views, as a better alternative to
1256 building such views on top of the "-interpreter-exec console"
1257 command. See the new "new-ui" command below. With that command,
1258 frontends can now start GDB in the traditional command-line mode
1259 running in an embedded terminal emulator widget, and create a
1260 separate MI interpreter running on a specified i/o device. In this
1261 way, GDB handles line editing, history, tab completion, etc. in the
1262 console all by itself, and the GUI uses the separate MI interpreter
1263 for its own control and synchronization, invisible to the command
1266 * The "catch syscall" command catches groups of related syscalls.
1268 The "catch syscall" command now supports catching a group of related
1269 syscalls using the 'group:' or 'g:' prefix.
1274 skip -gfile file-glob-pattern
1275 skip -function function
1276 skip -rfunction regular-expression
1277 A generalized form of the skip command, with new support for
1278 glob-style file names and regular expressions for function names.
1279 Additionally, a file spec and a function spec may now be combined.
1281 maint info line-table REGEXP
1282 Display the contents of GDB's internal line table data struture.
1285 Run any GDB unit tests that were compiled in.
1288 Start a new user interface instance running INTERP as interpreter,
1289 using the TTY file for input/output.
1293 ** gdb.Breakpoint objects have a new attribute "pending", which
1294 indicates whether the breakpoint is pending.
1295 ** Three new breakpoint-related events have been added:
1296 gdb.breakpoint_created, gdb.breakpoint_modified, and
1297 gdb.breakpoint_deleted.
1299 signal-event EVENTID
1300 Signal ("set") the given MS-Windows event object. This is used in
1301 conjunction with the Windows JIT debugging (AeDebug) support, where
1302 the OS suspends a crashing process until a debugger can attach to
1303 it. Resuming the crashing process, in order to debug it, is done by
1304 signalling an event.
1306 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1307 was added in GDBserver, including JIT compiling fast tracepoint's
1308 conditional expression bytecode into native code.
1310 * Support for various remote target protocols and ROM monitors has
1313 target m32rsdi Remote M32R debugging over SDI
1314 target mips MIPS remote debugging protocol
1315 target pmon PMON ROM monitor
1316 target ddb NEC's DDB variant of PMON for Vr4300
1317 target rockhopper NEC RockHopper variant of PMON
1318 target lsi LSI variant of PMO
1320 * Support for tracepoints and fast tracepoints on powerpc-linux,
1321 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1322 including JIT compiling fast tracepoint's conditional expression
1323 bytecode into native code.
1325 * MI async record =record-started now includes the method and format used for
1326 recording. For example:
1328 =record-started,thread-group="i1",method="btrace",format="bts"
1330 * MI async record =thread-selected now includes the frame field. For example:
1332 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1336 Andes NDS32 nds32*-*-elf
1338 *** Changes in GDB 7.11
1340 * GDB now supports debugging kernel-based threads on FreeBSD.
1342 * Per-inferior thread numbers
1344 Thread numbers are now per inferior instead of global. If you're
1345 debugging multiple inferiors, GDB displays thread IDs using a
1346 qualified INF_NUM.THR_NUM form. For example:
1350 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1351 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1352 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1353 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1355 As consequence, thread numbers as visible in the $_thread
1356 convenience variable and in Python's InferiorThread.num attribute
1357 are no longer unique between inferiors.
1359 GDB now maintains a second thread ID per thread, referred to as the
1360 global thread ID, which is the new equivalent of thread numbers in
1361 previous releases. See also $_gthread below.
1363 For backwards compatibility, MI's thread IDs always refer to global
1366 * Commands that accept thread IDs now accept the qualified
1367 INF_NUM.THR_NUM form as well. For example:
1370 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1373 * In commands that accept a list of thread IDs, you can now refer to
1374 all threads of an inferior using a star wildcard. GDB accepts
1375 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1376 refer to all threads of the current inferior. For example, "info
1379 * You can use "info threads -gid" to display the global thread ID of
1382 * The new convenience variable $_gthread holds the global number of
1385 * The new convenience variable $_inferior holds the number of the
1388 * GDB now displays the ID and name of the thread that hit a breakpoint
1389 or received a signal, if your program is multi-threaded. For
1392 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1393 Thread 1 "main" received signal SIGINT, Interrupt.
1395 * Record btrace now supports non-stop mode.
1397 * Support for tracepoints on aarch64-linux was added in GDBserver.
1399 * The 'record instruction-history' command now indicates speculative execution
1400 when using the Intel Processor Trace recording format.
1402 * GDB now allows users to specify explicit locations, bypassing
1403 the linespec parser. This feature is also available to GDB/MI
1406 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1407 GDB now is able to debug both AArch64 applications and ARM applications
1410 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1411 including JIT compiling fast tracepoint's conditional expression bytecode
1414 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1416 * "info threads", "info inferiors", "info display", "info checkpoints"
1417 and "maint info program-spaces" now list the corresponding items in
1418 ascending ID order, for consistency with all other "info" commands.
1420 * In Ada, the overloads selection menu has been enhanced to display the
1421 parameter types and the return types for the matching overloaded subprograms.
1425 maint set target-non-stop (on|off|auto)
1426 maint show target-non-stop
1427 Control whether GDB targets always operate in non-stop mode even if
1428 "set non-stop" is "off". The default is "auto", meaning non-stop
1429 mode is enabled if supported by the target.
1431 maint set bfd-sharing
1432 maint show bfd-sharing
1433 Control the reuse of bfd objects.
1436 show debug bfd-cache
1437 Control display of debugging info regarding bfd caching.
1441 Control display of debugging info regarding FreeBSD threads.
1443 set remote multiprocess-extensions-packet
1444 show remote multiprocess-extensions-packet
1445 Set/show the use of the remote protocol multiprocess extensions.
1447 set remote thread-events
1448 show remote thread-events
1449 Set/show the use of thread create/exit events.
1451 set ada print-signatures on|off
1452 show ada print-signatures"
1453 Control whether parameter types and return types are displayed in overloads
1454 selection menus. It is activaled (@code{on}) by default.
1458 Controls the maximum size of memory, in bytes, that GDB will
1459 allocate for value contents. Prevents incorrect programs from
1460 causing GDB to allocate overly large buffers. Default is 64k.
1462 * The "disassemble" command accepts a new modifier: /s.
1463 It prints mixed source+disassembly like /m with two differences:
1464 - disassembled instructions are now printed in program order, and
1465 - and source for all relevant files is now printed.
1466 The "/m" option is now considered deprecated: its "source-centric"
1467 output hasn't proved useful in practice.
1469 * The "record instruction-history" command accepts a new modifier: /s.
1470 It behaves exactly like /m and prints mixed source+disassembly.
1472 * The "set scheduler-locking" command supports a new mode "replay".
1473 It behaves like "off" in record mode and like "on" in replay mode.
1475 * Support for various ROM monitors has been removed:
1477 target dbug dBUG ROM monitor for Motorola ColdFire
1478 target picobug Motorola picobug monitor
1479 target dink32 DINK32 ROM monitor for PowerPC
1480 target m32r Renesas M32R/D ROM monitor
1481 target mon2000 mon2000 ROM monitor
1482 target ppcbug PPCBUG ROM monitor for PowerPC
1484 * Support for reading/writing memory and extracting values on architectures
1485 whose memory is addressable in units of any integral multiple of 8 bits.
1488 Allows to break when an Ada exception is handled.
1490 * New remote packets
1493 Indicates that an exec system call was executed.
1495 exec-events feature in qSupported
1496 The qSupported packet allows GDB to request support for exec
1497 events using the new 'gdbfeature' exec-event, and the qSupported
1498 response can contain the corresponding 'stubfeature'. Set and
1499 show commands can be used to display whether these features are enabled.
1502 Equivalent to interrupting with the ^C character, but works in
1505 thread created stop reason (T05 create:...)
1506 Indicates that the thread was just created and is stopped at entry.
1508 thread exit stop reply (w exitcode;tid)
1509 Indicates that the thread has terminated.
1512 Enables/disables thread create and exit event reporting. For
1513 example, this is used in non-stop mode when GDB stops a set of
1514 threads and synchronously waits for the their corresponding stop
1515 replies. Without exit events, if one of the threads exits, GDB
1516 would hang forever not knowing that it should no longer expect a
1517 stop for that same thread.
1520 Indicates that there are no resumed threads left in the target (all
1521 threads are stopped). The remote stub reports support for this stop
1522 reply to GDB's qSupported query.
1525 Enables/disables catching syscalls from the inferior process.
1526 The remote stub reports support for this packet to GDB's qSupported query.
1528 syscall_entry stop reason
1529 Indicates that a syscall was just called.
1531 syscall_return stop reason
1532 Indicates that a syscall just returned.
1534 * Extended-remote exec events
1536 ** GDB now has support for exec events on extended-remote Linux targets.
1537 For such targets with Linux kernels 2.5.46 and later, this enables
1538 follow-exec-mode and exec catchpoints.
1540 set remote exec-event-feature-packet
1541 show remote exec-event-feature-packet
1542 Set/show the use of the remote exec event feature.
1544 * Thread names in remote protocol
1546 The reply to qXfer:threads:read may now include a name attribute for each
1549 * Target remote mode fork and exec events
1551 ** GDB now has support for fork and exec events on target remote mode
1552 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1553 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1554 fork and exec catchpoints.
1556 * Remote syscall events
1558 ** GDB now has support for catch syscall on remote Linux targets,
1559 currently enabled on x86/x86_64 architectures.
1561 set remote catch-syscall-packet
1562 show remote catch-syscall-packet
1563 Set/show the use of the remote catch syscall feature.
1567 ** The -var-set-format command now accepts the zero-hexadecimal
1568 format. It outputs data in hexadecimal format with zero-padding on the
1573 ** gdb.InferiorThread objects have a new attribute "global_num",
1574 which refers to the thread's global thread ID. The existing
1575 "num" attribute now refers to the thread's per-inferior number.
1576 See "Per-inferior thread numbers" above.
1577 ** gdb.InferiorThread objects have a new attribute "inferior", which
1578 is the Inferior object the thread belongs to.
1580 *** Changes in GDB 7.10
1582 * Support for process record-replay and reverse debugging on aarch64*-linux*
1583 targets has been added. GDB now supports recording of A64 instruction set
1584 including advance SIMD instructions.
1586 * Support for Sun's version of the "stabs" debug file format has been removed.
1588 * GDB now honors the content of the file /proc/PID/coredump_filter
1589 (PID is the process ID) on GNU/Linux systems. This file can be used
1590 to specify the types of memory mappings that will be included in a
1591 corefile. For more information, please refer to the manual page of
1592 "core(5)". GDB also has a new command: "set use-coredump-filter
1593 on|off". It allows to set whether GDB will read the content of the
1594 /proc/PID/coredump_filter file when generating a corefile.
1596 * The "info os" command on GNU/Linux can now display information on
1598 "info os cpus" Listing of all cpus/cores on the system
1600 * GDB has two new commands: "set serial parity odd|even|none" and
1601 "show serial parity". These allows to set or show parity for the
1604 * The "info source" command now displays the producer string if it was
1605 present in the debug info. This typically includes the compiler version
1606 and may include things like its command line arguments.
1608 * The "info dll", an alias of the "info sharedlibrary" command,
1609 is now available on all platforms.
1611 * Directory names supplied to the "set sysroot" commands may be
1612 prefixed with "target:" to tell GDB to access shared libraries from
1613 the target system, be it local or remote. This replaces the prefix
1614 "remote:". The default sysroot has been changed from "" to
1615 "target:". "remote:" is automatically converted to "target:" for
1616 backward compatibility.
1618 * The system root specified by "set sysroot" will be prepended to the
1619 filename of the main executable (if reported to GDB as absolute by
1620 the operating system) when starting processes remotely, and when
1621 attaching to already-running local or remote processes.
1623 * GDB now supports automatic location and retrieval of executable
1624 files from remote targets. Remote debugging can now be initiated
1625 using only a "target remote" or "target extended-remote" command
1626 (no "set sysroot" or "file" commands are required). See "New remote
1629 * The "dump" command now supports verilog hex format.
1631 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1633 * On GNU/Linux, GDB and gdbserver are now able to access executable
1634 and shared library files without a "set sysroot" command when
1635 attaching to processes running in different mount namespaces from
1636 the debugger. This makes it possible to attach to processes in
1637 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1638 See "New remote packets" below.
1640 * The "tui reg" command now provides completion for all of the
1641 available register groups, including target specific groups.
1643 * The HISTSIZE environment variable is no longer read when determining
1644 the size of GDB's command history. GDB now instead reads the dedicated
1645 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1646 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1651 ** Memory ports can now be unbuffered.
1655 ** gdb.Objfile objects have a new attribute "username",
1656 which is the name of the objfile as specified by the user,
1657 without, for example, resolving symlinks.
1658 ** You can now write frame unwinders in Python.
1659 ** gdb.Type objects have a new method "optimized_out",
1660 returning optimized out gdb.Value instance of this type.
1661 ** gdb.Value objects have new methods "reference_value" and
1662 "const_value" which return a reference to the value and a
1663 "const" version of the value respectively.
1667 maint print symbol-cache
1668 Print the contents of the symbol cache.
1670 maint print symbol-cache-statistics
1671 Print statistics of symbol cache usage.
1673 maint flush-symbol-cache
1674 Flush the contents of the symbol cache.
1678 Start branch trace recording using Branch Trace Store (BTS) format.
1681 Evaluate expression by using the compiler and print result.
1685 Explicit commands for enabling and disabling tui mode.
1688 set mpx bound on i386 and amd64
1689 Support for bound table investigation on Intel MPX enabled applications.
1693 Start branch trace recording using Intel Processor Trace format.
1696 Print information about branch tracing internals.
1698 maint btrace packet-history
1699 Print the raw branch tracing data.
1701 maint btrace clear-packet-history
1702 Discard the stored raw branch tracing data.
1705 Discard all branch tracing data. It will be fetched and processed
1706 anew by the next "record" command.
1711 Renamed from "set debug dwarf2-die".
1712 show debug dwarf-die
1713 Renamed from "show debug dwarf2-die".
1715 set debug dwarf-read
1716 Renamed from "set debug dwarf2-read".
1717 show debug dwarf-read
1718 Renamed from "show debug dwarf2-read".
1720 maint set dwarf always-disassemble
1721 Renamed from "maint set dwarf2 always-disassemble".
1722 maint show dwarf always-disassemble
1723 Renamed from "maint show dwarf2 always-disassemble".
1725 maint set dwarf max-cache-age
1726 Renamed from "maint set dwarf2 max-cache-age".
1727 maint show dwarf max-cache-age
1728 Renamed from "maint show dwarf2 max-cache-age".
1730 set debug dwarf-line
1731 show debug dwarf-line
1732 Control display of debugging info regarding DWARF line processing.
1735 show max-completions
1736 Set the maximum number of candidates to be considered during
1737 completion. The default value is 200. This limit allows GDB
1738 to avoid generating large completion lists, the computation of
1739 which can cause the debugger to become temporarily unresponsive.
1741 set history remove-duplicates
1742 show history remove-duplicates
1743 Control the removal of duplicate history entries.
1745 maint set symbol-cache-size
1746 maint show symbol-cache-size
1747 Control the size of the symbol cache.
1749 set|show record btrace bts buffer-size
1750 Set and show the size of the ring buffer used for branch tracing in
1752 The obtained size may differ from the requested size. Use "info
1753 record" to see the obtained buffer size.
1755 set debug linux-namespaces
1756 show debug linux-namespaces
1757 Control display of debugging info regarding Linux namespaces.
1759 set|show record btrace pt buffer-size
1760 Set and show the size of the ring buffer used for branch tracing in
1761 Intel Processor Trace format.
1762 The obtained size may differ from the requested size. Use "info
1763 record" to see the obtained buffer size.
1765 maint set|show btrace pt skip-pad
1766 Set and show whether PAD packets are skipped when computing the
1769 * The command 'thread apply all' can now support new option '-ascending'
1770 to call its specified command for all threads in ascending order.
1772 * Python/Guile scripting
1774 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1775 special section named `.debug_gdb_scripts'.
1777 * New remote packets
1779 qXfer:btrace-conf:read
1780 Return the branch trace configuration for the current thread.
1782 Qbtrace-conf:bts:size
1783 Set the requested ring buffer size for branch tracing in BTS format.
1786 Enable Intel Procesor Trace-based branch tracing for the current
1787 process. The remote stub reports support for this packet to GDB's
1790 Qbtrace-conf:pt:size
1791 Set the requested ring buffer size for branch tracing in Intel Processor
1795 Indicates a memory breakpoint instruction was executed, irrespective
1796 of whether it was GDB that planted the breakpoint or the breakpoint
1797 is hardcoded in the program. This is required for correct non-stop
1801 Indicates the target stopped for a hardware breakpoint. This is
1802 required for correct non-stop mode operation.
1805 Return information about files on the remote system.
1807 qXfer:exec-file:read
1808 Return the full absolute name of the file that was executed to
1809 create a process running on the remote system.
1812 Select the filesystem on which vFile: operations with filename
1813 arguments will operate. This is required for GDB to be able to
1814 access files on remote targets where the remote stub does not
1815 share a common filesystem with the inferior(s).
1818 Indicates that a fork system call was executed.
1821 Indicates that a vfork system call was executed.
1823 vforkdone stop reason
1824 Indicates that a vfork child of the specified process has executed
1825 an exec or exit, allowing the vfork parent to resume execution.
1827 fork-events and vfork-events features in qSupported
1828 The qSupported packet allows GDB to request support for fork and
1829 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1830 and the qSupported response can contain the corresponding
1831 'stubfeatures'. Set and show commands can be used to display
1832 whether these features are enabled.
1834 * Extended-remote fork events
1836 ** GDB now has support for fork events on extended-remote Linux
1837 targets. For targets with Linux kernels 2.5.60 and later, this
1838 enables follow-fork-mode and detach-on-fork for both fork and
1839 vfork, as well as fork and vfork catchpoints.
1841 * The info record command now shows the recording format and the
1842 branch tracing configuration for the current thread when using
1843 the btrace record target.
1844 For the BTS format, it shows the ring buffer size.
1846 * GDB now has support for DTrace USDT (Userland Static Defined
1847 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1849 * GDB now supports access to vector registers on S/390 GNU/Linux
1852 * Removed command line options
1854 -xdb HP-UX XDB compatibility mode.
1856 * Removed targets and native configurations
1858 HP/PA running HP-UX hppa*-*-hpux*
1859 Itanium running HP-UX ia64-*-hpux*
1861 * New configure options
1864 This configure option allows the user to build GDB with support for
1865 Intel Processor Trace (default: auto). This requires libipt.
1867 --with-libipt-prefix=PATH
1868 Specify the path to the version of libipt that GDB should use.
1869 $PATH/include should contain the intel-pt.h header and
1870 $PATH/lib should contain the libipt.so library.
1872 *** Changes in GDB 7.9.1
1876 ** Xmethods can now specify a result type.
1878 *** Changes in GDB 7.9
1880 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1884 ** You can now access frame registers from Python scripts.
1885 ** New attribute 'producer' for gdb.Symtab objects.
1886 ** gdb.Objfile objects have a new attribute "progspace",
1887 which is the gdb.Progspace object of the containing program space.
1888 ** gdb.Objfile objects have a new attribute "owner".
1889 ** gdb.Objfile objects have a new attribute "build_id",
1890 which is the build ID generated when the file was built.
1891 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1892 ** A new event "gdb.clear_objfiles" has been added, triggered when
1893 selecting a new file to debug.
1894 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1895 ** New function gdb.lookup_objfile.
1897 New events which are triggered when GDB modifies the state of the
1900 ** gdb.events.inferior_call_pre: Function call is about to be made.
1901 ** gdb.events.inferior_call_post: Function call has just been made.
1902 ** gdb.events.memory_changed: A memory location has been altered.
1903 ** gdb.events.register_changed: A register has been altered.
1905 * New Python-based convenience functions:
1907 ** $_caller_is(name [, number_of_frames])
1908 ** $_caller_matches(regexp [, number_of_frames])
1909 ** $_any_caller_is(name [, number_of_frames])
1910 ** $_any_caller_matches(regexp [, number_of_frames])
1912 * GDB now supports the compilation and injection of source code into
1913 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1914 to compile the source code to object code, and if successful, inject
1915 and execute that code within the current context of the inferior.
1916 Currently the C language is supported. The commands used to
1917 interface with this new feature are:
1919 compile code [-raw|-r] [--] [source code]
1920 compile file [-raw|-r] filename
1924 demangle [-l language] [--] name
1925 Demangle "name" in the specified language, or the current language
1926 if elided. This command is renamed from the "maint demangle" command.
1927 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1928 as "maint demangler-warning".
1930 queue-signal signal-name-or-number
1931 Queue a signal to be delivered to the thread when it is resumed.
1933 add-auto-load-scripts-directory directory
1934 Add entries to the list of directories from which to load auto-loaded
1937 maint print user-registers
1938 List all currently available "user" registers.
1940 compile code [-r|-raw] [--] [source code]
1941 Compile, inject, and execute in the inferior the executable object
1942 code produced by compiling the provided source code.
1944 compile file [-r|-raw] filename
1945 Compile and inject into the inferior the executable object code
1946 produced by compiling the source code stored in the filename
1949 * On resume, GDB now always passes the signal the program had stopped
1950 for to the thread the signal was sent to, even if the user changed
1951 threads before resuming. Previously GDB would often (but not
1952 always) deliver the signal to the thread that happens to be current
1955 * Conversely, the "signal" command now consistently delivers the
1956 requested signal to the current thread. GDB now asks for
1957 confirmation if the program had stopped for a signal and the user
1958 switched threads meanwhile.
1960 * "breakpoint always-inserted" modes "off" and "auto" merged.
1962 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1963 won't remove breakpoints from the target until all threads stop,
1964 even in non-stop mode. The "auto" mode has been removed, and "off"
1965 is now the default mode.
1969 set debug symbol-lookup
1970 show debug symbol-lookup
1971 Control display of debugging info regarding symbol lookup.
1975 ** The -list-thread-groups command outputs an exit-code field for
1976 inferiors that have exited.
1980 MIPS SDE mips*-sde*-elf*
1984 Support for these obsolete configurations has been removed.
1986 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1987 SGI Irix-5.x mips-*-irix5*
1988 SGI Irix-6.x mips-*-irix6*
1989 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1990 VAX running Ultrix vax-*-ultrix*
1992 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1993 and "assf"), have been removed. Use the "sharedlibrary" command, or
1994 its alias "share", instead.
1996 *** Changes in GDB 7.8
1998 * New command line options
2001 This is an alias for the --data-directory option.
2003 * GDB supports printing and modifying of variable length automatic arrays
2004 as specified in ISO C99.
2006 * The ARM simulator now supports instruction level tracing
2007 with or without disassembly.
2011 GDB now has support for scripting using Guile. Whether this is
2012 available is determined at configure time.
2013 Guile version 2.0 or greater is required.
2014 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2016 * New commands (for set/show, see "New options" below)
2020 Invoke CODE by passing it to the Guile interpreter.
2024 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2026 info auto-load guile-scripts [regexp]
2027 Print the list of automatically loaded Guile scripts.
2029 * The source command is now capable of sourcing Guile scripts.
2030 This feature is dependent on the debugger being built with Guile support.
2034 set print symbol-loading (off|brief|full)
2035 show print symbol-loading
2036 Control whether to print informational messages when loading symbol
2037 information for a file. The default is "full", but when debugging
2038 programs with large numbers of shared libraries the amount of output
2039 becomes less useful.
2041 set guile print-stack (none|message|full)
2042 show guile print-stack
2043 Show a stack trace when an error is encountered in a Guile script.
2045 set auto-load guile-scripts (on|off)
2046 show auto-load guile-scripts
2047 Control auto-loading of Guile script files.
2049 maint ada set ignore-descriptive-types (on|off)
2050 maint ada show ignore-descriptive-types
2051 Control whether the debugger should ignore descriptive types in Ada
2052 programs. The default is not to ignore the descriptive types. See
2053 the user manual for more details on descriptive types and the intended
2054 usage of this option.
2056 set auto-connect-native-target
2058 Control whether GDB is allowed to automatically connect to the
2059 native target for the run, attach, etc. commands when not connected
2060 to any target yet. See also "target native" below.
2062 set record btrace replay-memory-access (read-only|read-write)
2063 show record btrace replay-memory-access
2064 Control what memory accesses are allowed during replay.
2066 maint set target-async (on|off)
2067 maint show target-async
2068 This controls whether GDB targets operate in synchronous or
2069 asynchronous mode. Normally the default is asynchronous, if it is
2070 available; but this can be changed to more easily debug problems
2071 occurring only in synchronous mode.
2073 set mi-async (on|off)
2075 Control whether MI asynchronous mode is preferred. This supersedes
2076 "set target-async" of previous GDB versions.
2078 * "set target-async" is deprecated as a CLI option and is now an alias
2079 for "set mi-async" (only puts MI into async mode).
2081 * Background execution commands (e.g., "c&", "s&", etc.) are now
2082 possible ``out of the box'' if the target supports them. Previously
2083 the user would need to explicitly enable the possibility with the
2084 "set target-async on" command.
2086 * New features in the GDB remote stub, GDBserver
2088 ** New option --debug-format=option1[,option2,...] allows one to add
2089 additional text to each output. At present only timestamps
2090 are supported: --debug-format=timestamps.
2091 Timestamps can also be turned on with the
2092 "monitor set debug-format timestamps" command from GDB.
2094 * The 'record instruction-history' command now starts counting instructions
2095 at one. This also affects the instruction ranges reported by the
2096 'record function-call-history' command when given the /i modifier.
2098 * The command 'record function-call-history' supports a new modifier '/c' to
2099 indent the function names based on their call stack depth.
2100 The fields for the '/i' and '/l' modifier have been reordered.
2101 The source line range is now prefixed with 'at'.
2102 The instruction range is now prefixed with 'inst'.
2103 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2104 "record instruction-history" and "list" commands.
2106 * The ranges given as arguments to the 'record function-call-history' and
2107 'record instruction-history' commands are now inclusive.
2109 * The btrace record target now supports the 'record goto' command.
2110 For locations inside the execution trace, the back trace is computed
2111 based on the information stored in the execution trace.
2113 * The btrace record target supports limited reverse execution and replay.
2114 The target does not record data and therefore does not allow reading
2115 memory or registers.
2117 * The "catch syscall" command now works on s390*-linux* targets.
2119 * The "compare-sections" command is no longer specific to target
2120 remote. It now works with all targets.
2122 * All native targets are now consistently called "native".
2123 Consequently, the "target child", "target GNU", "target djgpp",
2124 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2125 commands have been replaced with "target native". The QNX/NTO port
2126 leaves the "procfs" target in place and adds a "native" target for
2127 consistency with other ports. The impact on users should be minimal
2128 as these commands previously either throwed an error, or were
2129 no-ops. The target's name is visible in the output of the following
2130 commands: "help target", "info target", "info files", "maint print
2133 * The "target native" command now connects to the native target. This
2134 can be used to launch native programs even when "set
2135 auto-connect-native-target" is set to off.
2137 * GDB now supports access to Intel MPX registers on GNU/Linux.
2139 * Support for Intel AVX-512 registers on GNU/Linux.
2140 Support displaying and modifying Intel AVX-512 registers
2141 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2143 * New remote packets
2145 qXfer:btrace:read's annex
2146 The qXfer:btrace:read packet supports a new annex 'delta' to read
2147 branch trace incrementally.
2151 ** Valid Python operations on gdb.Value objects representing
2152 structs/classes invoke the corresponding overloaded operators if
2154 ** New `Xmethods' feature in the Python API. Xmethods are
2155 additional methods or replacements for existing methods of a C++
2156 class. This feature is useful for those cases where a method
2157 defined in C++ source code could be inlined or optimized out by
2158 the compiler, making it unavailable to GDB.
2161 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2163 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2164 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2165 its alias "share", instead.
2167 * The commands "set remotebaud" and "show remotebaud" are no longer
2168 supported. Use "set serial baud" and "show serial baud" (respectively)
2173 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2174 target-async". The latter is left as a deprecated alias of the
2175 former for backward compatibility. If the target supports it,
2176 CLI background execution commands are now always possible by
2177 default, independently of whether the frontend stated a
2178 preference for asynchronous execution with "-gdb-set mi-async".
2179 Previously "-gdb-set target-async off" affected both MI execution
2180 commands and CLI execution commands.
2182 *** Changes in GDB 7.7
2184 * Improved support for process record-replay and reverse debugging on
2185 arm*-linux* targets. Support for thumb32 and syscall instruction
2186 recording has been added.
2188 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2190 * GDB now supports Fission DWP file format version 2.
2191 http://gcc.gnu.org/wiki/DebugFission
2193 * New convenience function "$_isvoid", to check whether an expression
2194 is void. A void expression is an expression where the type of the
2195 result is "void". For example, some convenience variables may be
2196 "void" when evaluated (e.g., "$_exitcode" before the execution of
2197 the program being debugged; or an undefined convenience variable).
2198 Another example, when calling a function whose return type is
2201 * The "maintenance print objfiles" command now takes an optional regexp.
2203 * The "catch syscall" command now works on arm*-linux* targets.
2205 * GDB now consistently shows "<not saved>" when printing values of
2206 registers the debug info indicates have not been saved in the frame
2207 and there's nowhere to retrieve them from
2208 (callee-saved/call-clobbered registers):
2213 (gdb) info registers rax
2216 Before, the former would print "<optimized out>", and the latter
2217 "*value not available*".
2219 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2224 ** Frame filters and frame decorators have been added.
2225 ** Temporary breakpoints are now supported.
2226 ** Line tables representation has been added.
2227 ** New attribute 'parent_type' for gdb.Field objects.
2228 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2229 ** New attribute 'name' for gdb.Type objects.
2233 Nios II ELF nios2*-*-elf
2234 Nios II GNU/Linux nios2*-*-linux
2235 Texas Instruments MSP430 msp430*-*-elf
2237 * Removed native configurations
2239 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2240 been removed. ELF variants of these configurations are kept supported.
2242 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2243 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2244 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2245 i[34567]86-*-openbsd3.[0-3]
2246 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2247 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2248 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2252 Like "catch throw", but catches a re-thrown exception.
2253 maint check-psymtabs
2254 Renamed from old "maint check-symtabs".
2256 Perform consistency checks on symtabs.
2257 maint expand-symtabs
2258 Expand symtabs matching an optional regexp.
2261 Display the details of GDB configure-time options.
2263 maint set|show per-command
2264 maint set|show per-command space
2265 maint set|show per-command time
2266 maint set|show per-command symtab
2267 Enable display of per-command gdb resource usage.
2269 remove-symbol-file FILENAME
2270 remove-symbol-file -a ADDRESS
2271 Remove a symbol file added via add-symbol-file. The file to remove
2272 can be identified by its filename or by an address that lies within
2273 the boundaries of this symbol file in memory.
2276 info exceptions REGEXP
2277 Display the list of Ada exceptions defined in the program being
2278 debugged. If provided, only the exceptions whose names match REGEXP
2283 set debug symfile off|on
2285 Control display of debugging info regarding reading symbol files and
2286 symbol tables within those files
2288 set print raw frame-arguments
2289 show print raw frame-arguments
2290 Set/show whether to print frame arguments in raw mode,
2291 disregarding any defined pretty-printers.
2293 set remote trace-status-packet
2294 show remote trace-status-packet
2295 Set/show the use of remote protocol qTStatus packet.
2299 Control display of debugging messages related to Nios II targets.
2303 Control whether target-assisted range stepping is enabled.
2305 set startup-with-shell
2306 show startup-with-shell
2307 Specifies whether Unix child processes are started via a shell or
2312 Use the target memory cache for accesses to the code segment. This
2313 improves performance of remote debugging (particularly disassembly).
2315 * You can now use a literal value 'unlimited' for options that
2316 interpret 0 or -1 as meaning "unlimited". E.g., "set
2317 trace-buffer-size unlimited" is now an alias for "set
2318 trace-buffer-size -1" and "set height unlimited" is now an alias for
2321 * The "set debug symtab-create" debugging option of GDB has been changed to
2322 accept a verbosity level. 0 means "off", 1 provides basic debugging
2323 output, and values of 2 or greater provides more verbose output.
2325 * New command-line options
2327 Display the details of GDB configure-time options.
2329 * The command 'tsave' can now support new option '-ctf' to save trace
2330 buffer in Common Trace Format.
2332 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2335 * GDB now implements the the C++ 'typeid' operator.
2337 * The new convenience variable $_exception holds the exception being
2338 thrown or caught at an exception-related catchpoint.
2340 * The exception-related catchpoints, like "catch throw", now accept a
2341 regular expression which can be used to filter exceptions by type.
2343 * The new convenience variable $_exitsignal is automatically set to
2344 the terminating signal number when the program being debugged dies
2345 due to an uncaught signal.
2349 ** All MI commands now accept an optional "--language" option.
2350 Support for this feature can be verified by using the "-list-features"
2351 command, which should contain "language-option".
2353 ** The new command -info-gdb-mi-command allows the user to determine
2354 whether a GDB/MI command is supported or not.
2356 ** The "^error" result record returned when trying to execute an undefined
2357 GDB/MI command now provides a variable named "code" whose content is the
2358 "undefined-command" error code. Support for this feature can be verified
2359 by using the "-list-features" command, which should contain
2360 "undefined-command-error-code".
2362 ** The -trace-save MI command can optionally save trace buffer in Common
2365 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2367 ** The command -data-list-register-values now accepts an optional
2368 "--skip-unavailable" option. When used, only the available registers
2371 ** The new command -trace-frame-collected dumps collected variables,
2372 computed expressions, tvars, memory and registers in a traceframe.
2374 ** The commands -stack-list-locals, -stack-list-arguments and
2375 -stack-list-variables now accept an option "--skip-unavailable".
2376 When used, only the available locals or arguments are displayed.
2378 ** The -exec-run command now accepts an optional "--start" option.
2379 When used, the command follows the same semantics as the "start"
2380 command, stopping the program's execution at the start of its
2381 main subprogram. Support for this feature can be verified using
2382 the "-list-features" command, which should contain
2383 "exec-run-start-option".
2385 ** The new commands -catch-assert and -catch-exceptions insert
2386 catchpoints stopping the program when Ada exceptions are raised.
2388 ** The new command -info-ada-exceptions provides the equivalent of
2389 the new "info exceptions" command.
2391 * New system-wide configuration scripts
2392 A GDB installation now provides scripts suitable for use as system-wide
2393 configuration scripts for the following systems:
2397 * GDB now supports target-assigned range stepping with remote targets.
2398 This improves the performance of stepping source lines by reducing
2399 the number of control packets from/to GDB. See "New remote packets"
2402 * GDB now understands the element 'tvar' in the XML traceframe info.
2403 It has the id of the collected trace state variables.
2405 * On S/390 targets that provide the transactional-execution feature,
2406 the program interruption transaction diagnostic block (TDB) is now
2407 represented as a number of additional "registers" in GDB.
2409 * New remote packets
2413 The vCont packet supports a new 'r' action, that tells the remote
2414 stub to step through an address range itself, without GDB
2415 involvemement at each single-step.
2417 qXfer:libraries-svr4:read's annex
2418 The previously unused annex of the qXfer:libraries-svr4:read packet
2419 is now used to support passing an argument list. The remote stub
2420 reports support for this argument list to GDB's qSupported query.
2421 The defined arguments are "start" and "prev", used to reduce work
2422 necessary for library list updating, resulting in significant
2425 * New features in the GDB remote stub, GDBserver
2427 ** GDBserver now supports target-assisted range stepping. Currently
2428 enabled on x86/x86_64 GNU/Linux targets.
2430 ** GDBserver now adds element 'tvar' in the XML in the reply to
2431 'qXfer:traceframe-info:read'. It has the id of the collected
2432 trace state variables.
2434 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2437 * New 'z' formatter for printing and examining memory, this displays the
2438 value as hexadecimal zero padded on the left to the size of the type.
2440 * GDB can now use Windows x64 unwinding data.
2442 * The "set remotebaud" command has been replaced by "set serial baud".
2443 Similarly, "show remotebaud" has been replaced by "show serial baud".
2444 The "set remotebaud" and "show remotebaud" commands are still available
2445 to provide backward compatibility with older versions of GDB.
2447 *** Changes in GDB 7.6
2449 * Target record has been renamed to record-full.
2450 Record/replay is now enabled with the "record full" command.
2451 This also affects settings that are associated with full record/replay
2452 that have been moved from "set/show record" to "set/show record full":
2454 set|show record full insn-number-max
2455 set|show record full stop-at-limit
2456 set|show record full memory-query
2458 * A new record target "record-btrace" has been added. The new target
2459 uses hardware support to record the control-flow of a process. It
2460 does not support replaying the execution, but it implements the
2461 below new commands for investigating the recorded execution log.
2462 This new recording method can be enabled using:
2466 The "record-btrace" target is only available on Intel Atom processors
2467 and requires a Linux kernel 2.6.32 or later.
2469 * Two new commands have been added for record/replay to give information
2470 about the recorded execution without having to replay the execution.
2471 The commands are only supported by "record btrace".
2473 record instruction-history prints the execution history at
2474 instruction granularity
2476 record function-call-history prints the execution history at
2477 function granularity
2479 * New native configurations
2481 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2482 FreeBSD/powerpc powerpc*-*-freebsd
2483 x86_64/Cygwin x86_64-*-cygwin*
2484 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2488 ARM AArch64 aarch64*-*-elf
2489 ARM AArch64 GNU/Linux aarch64*-*-linux
2490 Lynx 178 PowerPC powerpc-*-lynx*178
2491 x86_64/Cygwin x86_64-*-cygwin*
2492 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2494 * If the configured location of system.gdbinit file (as given by the
2495 --with-system-gdbinit option at configure time) is in the
2496 data-directory (as specified by --with-gdb-datadir at configure
2497 time) or in one of its subdirectories, then GDB will look for the
2498 system-wide init file in the directory specified by the
2499 --data-directory command-line option.
2501 * New command line options:
2503 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2504 other initialization files, unlike -nx which disables all of them.
2506 * Removed command line options
2508 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2511 * The 'ptype' and 'whatis' commands now accept an argument to control
2514 * 'info proc' now works on some core files.
2518 ** Vectors can be created with gdb.Type.vector.
2520 ** Python's atexit.register now works in GDB.
2522 ** Types can be pretty-printed via a Python API.
2524 ** Python 3 is now supported (in addition to Python 2.4 or later)
2526 ** New class gdb.Architecture exposes GDB's internal representation
2527 of architecture in the Python API.
2529 ** New method Frame.architecture returns the gdb.Architecture object
2530 corresponding to the frame's architecture.
2532 * New Python-based convenience functions:
2534 ** $_memeq(buf1, buf2, length)
2535 ** $_streq(str1, str2)
2537 ** $_regex(str, regex)
2539 * The 'cd' command now defaults to using '~' (the home directory) if not
2542 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2543 default for GCC since November 2000.
2545 * The command 'forward-search' can now be abbreviated as 'fo'.
2547 * The command 'info tracepoints' can now display 'installed on target'
2548 or 'not installed on target' for each non-pending location of tracepoint.
2550 * New configure options
2552 --enable-libmcheck/--disable-libmcheck
2553 By default, development versions are built with -lmcheck on hosts
2554 that support it, in order to help track memory corruption issues.
2555 Release versions, on the other hand, are built without -lmcheck
2556 by default. The --enable-libmcheck/--disable-libmcheck configure
2557 options allow the user to override that default.
2558 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2559 This configure option allows the user to build GDB with
2560 libbabeltrace using which GDB can read Common Trace Format data.
2562 * New commands (for set/show, see "New options" below)
2565 Catch signals. This is similar to "handle", but allows commands and
2566 conditions to be attached.
2569 List the BFDs known to GDB.
2571 python-interactive [command]
2573 Start a Python interactive prompt, or evaluate the optional command
2574 and print the result of expressions.
2577 "py" is a new alias for "python".
2579 enable type-printer [name]...
2580 disable type-printer [name]...
2581 Enable or disable type printers.
2585 ** For the Renesas Super-H architecture, the "regs" command has been removed
2586 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2591 set print type methods (on|off)
2592 show print type methods
2593 Control whether method declarations are displayed by "ptype".
2594 The default is to show them.
2596 set print type typedefs (on|off)
2597 show print type typedefs
2598 Control whether typedef definitions are displayed by "ptype".
2599 The default is to show them.
2601 set filename-display basename|relative|absolute
2602 show filename-display
2603 Control the way in which filenames is displayed.
2604 The default is "relative", which preserves previous behavior.
2606 set trace-buffer-size
2607 show trace-buffer-size
2608 Request target to change the size of trace buffer.
2610 set remote trace-buffer-size-packet auto|on|off
2611 show remote trace-buffer-size-packet
2612 Control the use of the remote protocol `QTBuffer:size' packet.
2616 Control display of debugging messages related to ARM AArch64.
2619 set debug coff-pe-read
2620 show debug coff-pe-read
2621 Control display of debugging messages related to reading of COFF/PE
2626 Control display of debugging messages related to Mach-O symbols
2629 set debug notification
2630 show debug notification
2631 Control display of debugging info for async remote notification.
2635 ** Command parameter changes are now notified using new async record
2636 "=cmd-param-changed".
2637 ** Trace frame changes caused by command "tfind" are now notified using
2638 new async record "=traceframe-changed".
2639 ** The creation, deletion and modification of trace state variables
2640 are now notified using new async records "=tsv-created",
2641 "=tsv-deleted" and "=tsv-modified".
2642 ** The start and stop of process record are now notified using new
2643 async record "=record-started" and "=record-stopped".
2644 ** Memory changes are now notified using new async record
2646 ** The data-disassemble command response will include a "fullname" field
2647 containing the absolute file name when source has been requested.
2648 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2649 command, to allow pattern filling of memory areas.
2650 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2651 library load/unload events.
2652 ** The response to breakpoint commands and breakpoint async records
2653 includes an "installed" field containing a boolean state about each
2654 non-pending tracepoint location is whether installed on target or not.
2655 ** Output of the "-trace-status" command includes a "trace-file" field
2656 containing the name of the trace file being examined. This field is
2657 optional, and only present when examining a trace file.
2658 ** The "fullname" field is now always present along with the "file" field,
2659 even if the file cannot be found by GDB.
2661 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2662 You must have the LZMA library available when configuring GDB for this
2663 feature to be enabled. For more information, see:
2664 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2666 * New remote packets
2669 Set the size of trace buffer. The remote stub reports support for this
2670 packet to gdb's qSupported query.
2673 Enable Branch Trace Store (BTS)-based branch tracing for the current
2674 thread. The remote stub reports support for this packet to gdb's
2678 Disable branch tracing for the current thread. The remote stub reports
2679 support for this packet to gdb's qSupported query.
2682 Read the traced branches for the current thread. The remote stub
2683 reports support for this packet to gdb's qSupported query.
2685 *** Changes in GDB 7.5
2687 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2688 for more x32 ABI info.
2690 * GDB now supports access to MIPS DSP registers on Linux targets.
2692 * GDB now supports debugging microMIPS binaries.
2694 * The "info os" command on GNU/Linux can now display information on
2695 several new classes of objects managed by the operating system:
2696 "info os procgroups" lists process groups
2697 "info os files" lists file descriptors
2698 "info os sockets" lists internet-domain sockets
2699 "info os shm" lists shared-memory regions
2700 "info os semaphores" lists semaphores
2701 "info os msg" lists message queues
2702 "info os modules" lists loaded kernel modules
2704 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2705 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2706 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2707 options and inspect the probe arguments using the new $_probe_arg family
2708 of convenience variables. You can obtain more information about SystemTap
2709 in <http://sourceware.org/systemtap/>.
2711 * GDB now supports reversible debugging on ARM, it allows you to
2712 debug basic ARM and THUMB instructions, and provides
2713 record/replay support.
2715 * The option "symbol-reloading" has been deleted as it is no longer used.
2719 ** GDB commands implemented in Python can now be put in command class
2722 ** The "maint set python print-stack on|off" is now deleted.
2724 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2725 apply "flag enum"-style pretty-printing to any enum.
2727 ** gdb.lookup_symbol can now work when there is no current frame.
2729 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2730 the source at which the symbol was defined.
2732 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2733 method 'value'. The former indicates whether the symbol needs a
2734 frame in order to compute its value, and the latter computes the
2737 ** A new method 'referenced_value' on gdb.Value objects which can
2738 dereference pointer as well as C++ reference values.
2740 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2741 which return the global and static blocks (as gdb.Block objects),
2742 of the underlying symbol table, respectively.
2744 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2745 object associated with a PC value.
2747 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2748 of the address range occupied by code for the current source line.
2750 * Go language support.
2751 GDB now supports debugging programs written in the Go programming
2754 * GDBserver now supports stdio connections.
2755 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2757 * The binary "gdbtui" can no longer be built or installed.
2758 Use "gdb -tui" instead.
2760 * GDB will now print "flag" enums specially. A flag enum is one where
2761 all the enumerator values have no bits in common when pairwise
2762 "and"ed. When printing a value whose type is a flag enum, GDB will
2763 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2764 (gdb) print (enum E) 3
2767 * The filename part of a linespec will now match trailing components
2768 of a source file name. For example, "break gcc/expr.c:1000" will
2769 now set a breakpoint in build/gcc/expr.c, but not
2770 build/libcpp/expr.c.
2772 * The "info proc" and "generate-core-file" commands will now also
2773 work on remote targets connected to GDBserver on Linux.
2775 * The command "info catch" has been removed. It has been disabled
2776 since December 2007.
2778 * The "catch exception" and "catch assert" commands now accept
2779 a condition at the end of the command, much like the "break"
2780 command does. For instance:
2782 (gdb) catch exception Constraint_Error if Barrier = True
2784 Previously, it was possible to add a condition to such catchpoints,
2785 but it had to be done as a second step, after the catchpoint had been
2786 created, using the "condition" command.
2788 * The "info static-tracepoint-marker" command will now also work on
2789 native Linux targets with in-process agent.
2791 * GDB can now set breakpoints on inlined functions.
2793 * The .gdb_index section has been updated to include symbols for
2794 inlined functions. GDB will ignore older .gdb_index sections by
2795 default, which could cause symbol files to be loaded more slowly
2796 until their .gdb_index sections can be recreated. The new command
2797 "set use-deprecated-index-sections on" will cause GDB to use any older
2798 .gdb_index sections it finds. This will restore performance, but the
2799 ability to set breakpoints on inlined functions will be lost in symbol
2800 files with older .gdb_index sections.
2802 The .gdb_index section has also been updated to record more information
2803 about each symbol. This speeds up the "info variables", "info functions"
2804 and "info types" commands when used with programs having the .gdb_index
2805 section, as well as speeding up debugging with shared libraries using
2806 the .gdb_index section.
2808 * Ada support for GDB/MI Variable Objects has been added.
2810 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2815 ** New command -info-os is the MI equivalent of "info os".
2817 ** Output logs ("set logging" and related) now include MI output.
2821 ** "set use-deprecated-index-sections on|off"
2822 "show use-deprecated-index-sections on|off"
2823 Controls the use of deprecated .gdb_index sections.
2825 ** "catch load" and "catch unload" can be used to stop when a shared
2826 library is loaded or unloaded, respectively.
2828 ** "enable count" can be used to auto-disable a breakpoint after
2831 ** "info vtbl" can be used to show the virtual method tables for
2832 C++ and Java objects.
2834 ** "explore" and its sub commands "explore value" and "explore type"
2835 can be used to recursively explore values and types of
2836 expressions. These commands are available only if GDB is
2837 configured with '--with-python'.
2839 ** "info auto-load" shows status of all kinds of auto-loaded files,
2840 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2841 sequences of commands files, "info auto-load python-scripts"
2842 shows status of auto-loading Python script files,
2843 "info auto-load local-gdbinit" shows status of loading init file
2844 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2845 status of inferior specific thread debugging shared library loading.
2847 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2848 and "show auto-load-scripts" commands have been deprecated, use their
2849 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2850 and "show auto-load python-scripts" counterparts instead.
2852 ** "dprintf location,format,args..." creates a dynamic printf, which
2853 is basically a breakpoint that does a printf and immediately
2854 resumes your program's execution, so it is like a printf that you
2855 can insert dynamically at runtime instead of at compiletime.
2857 ** "set print symbol"
2859 Controls whether GDB attempts to display the symbol, if any,
2860 corresponding to addresses it prints. This defaults to "on", but
2861 you can set it to "off" to restore GDB's previous behavior.
2863 * Deprecated commands
2865 ** For the Renesas Super-H architecture, the "regs" command has been
2866 deprecated, and "info all-registers" should be used instead.
2870 Renesas RL78 rl78-*-elf
2871 HP OpenVMS ia64 ia64-hp-openvms*
2873 * GDBserver supports evaluation of breakpoint conditions. When
2874 support is advertised by GDBserver, GDB may be told to send the
2875 breakpoint conditions in bytecode form to GDBserver. GDBserver
2876 will only report the breakpoint trigger to GDB when its condition
2881 set mips compression
2882 show mips compression
2883 Select the compressed ISA encoding used in functions that have no symbol
2884 information available. The encoding can be set to either of:
2887 and is updated automatically from ELF file flags if available.
2889 set breakpoint condition-evaluation
2890 show breakpoint condition-evaluation
2891 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2892 GDBserver ("target"). Default option "auto" chooses the most efficient
2894 This option can improve debugger efficiency depending on the speed of the
2898 Disable auto-loading globally.
2901 Show auto-loading setting of all kinds of auto-loaded files.
2903 set auto-load gdb-scripts on|off
2904 show auto-load gdb-scripts
2905 Control auto-loading of GDB canned sequences of commands files.
2907 set auto-load python-scripts on|off
2908 show auto-load python-scripts
2909 Control auto-loading of Python script files.
2911 set auto-load local-gdbinit on|off
2912 show auto-load local-gdbinit
2913 Control loading of init file (.gdbinit) from current directory.
2915 set auto-load libthread-db on|off
2916 show auto-load libthread-db
2917 Control auto-loading of inferior specific thread debugging shared library.
2919 set auto-load scripts-directory <dir1>[:<dir2>...]
2920 show auto-load scripts-directory
2921 Set a list of directories from which to load auto-loaded scripts.
2922 Automatically loaded Python scripts and GDB scripts are located in one
2923 of the directories listed by this option.
2924 The delimiter (':' above) may differ according to the host platform.
2926 set auto-load safe-path <dir1>[:<dir2>...]
2927 show auto-load safe-path
2928 Set a list of directories from which it is safe to auto-load files.
2929 The delimiter (':' above) may differ according to the host platform.
2931 set debug auto-load on|off
2932 show debug auto-load
2933 Control display of debugging info for auto-loading the files above.
2935 set dprintf-style gdb|call|agent
2937 Control the way in which a dynamic printf is performed; "gdb"
2938 requests a GDB printf command, while "call" causes dprintf to call a
2939 function in the inferior. "agent" requests that the target agent
2940 (such as GDBserver) do the printing.
2942 set dprintf-function <expr>
2943 show dprintf-function
2944 set dprintf-channel <expr>
2945 show dprintf-channel
2946 Set the function and optional first argument to the call when using
2947 the "call" style of dynamic printf.
2949 set disconnected-dprintf on|off
2950 show disconnected-dprintf
2951 Control whether agent-style dynamic printfs continue to be in effect
2952 after GDB disconnects.
2954 * New configure options
2956 --with-auto-load-dir
2957 Configure default value for the 'set auto-load scripts-directory'
2958 setting above. It defaults to '$debugdir:$datadir/auto-load',
2959 $debugdir representing global debugging info directories (available
2960 via 'show debug-file-directory') and $datadir representing GDB's data
2961 directory (available via 'show data-directory').
2963 --with-auto-load-safe-path
2964 Configure default value for the 'set auto-load safe-path' setting
2965 above. It defaults to the --with-auto-load-dir setting.
2967 --without-auto-load-safe-path
2968 Set 'set auto-load safe-path' to '/', effectively disabling this
2971 * New remote packets
2973 z0/z1 conditional breakpoints extension
2975 The z0/z1 breakpoint insertion packets have been extended to carry
2976 a list of conditional expressions over to the remote stub depending on the
2977 condition evaluation mode. The use of this extension can be controlled
2978 via the "set remote conditional-breakpoints-packet" command.
2982 Specify the signals which the remote stub may pass to the debugged
2983 program without GDB involvement.
2985 * New command line options
2987 --init-command=FILE, -ix Like --command, -x but execute it
2988 before loading inferior.
2989 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2990 execute it before loading inferior.
2992 *** Changes in GDB 7.4
2994 * GDB now handles ambiguous linespecs more consistently; the existing
2995 FILE:LINE support has been expanded to other types of linespecs. A
2996 breakpoint will now be set on all matching locations in all
2997 inferiors, and locations will be added or removed according to
3000 * GDB now allows you to skip uninteresting functions and files when
3001 stepping with the "skip function" and "skip file" commands.
3003 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3004 and "show remote hardware-watchpoint-length-limit". These allows to
3005 set or show the maximum length limit (in bytes) of a remote
3006 target hardware watchpoint.
3008 This allows e.g. to use "unlimited" hardware watchpoints with the
3009 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3010 watchpoints are slower than real hardware watchpoints but are
3011 significantly faster than gdb software watchpoints.
3015 ** The register_pretty_printer function in module gdb.printing now takes
3016 an optional `replace' argument. If True, the new printer replaces any
3019 ** The "maint set python print-stack on|off" command has been
3020 deprecated and will be deleted in GDB 7.5.
3021 A new command: "set python print-stack none|full|message" has
3022 replaced it. Additionally, the default for "print-stack" is
3023 now "message", which just prints the error message without
3026 ** A prompt substitution hook (prompt_hook) is now available to the
3029 ** A new Python module, gdb.prompt has been added to the GDB Python
3030 modules library. This module provides functionality for
3031 escape sequences in prompts (used by set/show
3032 extended-prompt). These escape sequences are replaced by their
3033 corresponding value.
3035 ** Python commands and convenience-functions located in
3036 'data-directory'/python/gdb/command and
3037 'data-directory'/python/gdb/function are now automatically loaded
3040 ** Blocks now provide four new attributes. global_block and
3041 static_block will return the global and static blocks
3042 respectively. is_static and is_global are boolean attributes
3043 that indicate if the block is one of those two types.
3045 ** Symbols now provide the "type" attribute, the type of the symbol.
3047 ** The "gdb.breakpoint" function has been deprecated in favor of
3050 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3051 of a function. This class is based on the "finish" command
3052 available in the CLI.
3054 ** Type objects for struct and union types now allow access to
3055 the fields using standard Python dictionary (mapping) methods.
3056 For example, "some_type['myfield']" now works, as does
3057 "some_type.items()".
3059 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3062 ** A new function, "deep_items" has been added to the gdb.types
3063 module in the GDB Python modules library. This function returns
3064 an iterator over the fields of a struct or union type. Unlike
3065 the standard Python "iteritems" method, it will recursively traverse
3066 any anonymous fields.
3070 ** "*stopped" events can report several new "reason"s, such as
3073 ** Breakpoint changes are now notified using new async records, like
3074 "=breakpoint-modified".
3076 ** New command -ada-task-info.
3078 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3079 $sdir specifies the default system locations of shared libraries.
3080 $pdir specifies the directory where the libpthread used by the application
3083 GDB no longer looks in $sdir and $pdir after it has searched the directories
3084 mentioned in libthread-db-search-path. If you want to search those
3085 directories, they must be specified in libthread-db-search-path.
3086 The default value of libthread-db-search-path on GNU/Linux and Solaris
3087 systems is now "$sdir:$pdir".
3089 $pdir is not supported by gdbserver, it is currently ignored.
3090 $sdir is supported by gdbserver.
3092 * New configure option --with-iconv-bin.
3093 When using the internationalization support like the one in the GNU C
3094 library, GDB will invoke the "iconv" program to get a list of supported
3095 character sets. If this program lives in a non-standard location, one can
3096 use this option to specify where to find it.
3098 * When natively debugging programs on PowerPC BookE processors running
3099 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3100 watchpoints, which specify a mask in addition to an address to watch.
3101 The mask specifies that some bits of an address (the bits which are
3102 reset in the mask) should be ignored when matching the address accessed
3103 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3104 section in the user manual for more details.
3106 * The new option --once causes GDBserver to stop listening for connections once
3107 the first connection is made. The listening port used by GDBserver will
3108 become available after that.
3110 * New commands "info macros" and "alias" have been added.
3112 * New function parameters suffix @entry specifies value of function parameter
3113 at the time the function got called. Entry values are available only since
3119 "!" is now an alias of the "shell" command.
3120 Note that no space is needed between "!" and SHELL COMMAND.
3124 watch EXPRESSION mask MASK_VALUE
3125 The watch command now supports the mask argument which allows creation
3126 of masked watchpoints, if the current architecture supports this feature.
3128 info auto-load-scripts [REGEXP]
3129 This command was formerly named "maintenance print section-scripts".
3130 It is now generally useful and is no longer a maintenance-only command.
3132 info macro [-all] [--] MACRO
3133 The info macro command has new options `-all' and `--'. The first for
3134 printing all definitions of a macro. The second for explicitly specifying
3135 the end of arguments and the beginning of the macro name in case the macro
3136 name starts with a hyphen.
3138 collect[/s] EXPRESSIONS
3139 The tracepoint collect command now takes an optional modifier "/s"
3140 that directs it to dereference pointer-to-character types and
3141 collect the bytes of memory up to a zero byte. The behavior is
3142 similar to what you see when you use the regular print command on a
3143 string. An optional integer following the "/s" sets a bound on the
3144 number of bytes that will be collected.
3147 The trace start command now interprets any supplied arguments as a
3148 note to be recorded with the trace run, with an effect similar to
3149 setting the variable trace-notes.
3152 The trace stop command now interprets any arguments as a note to be
3153 mentioned along with the tstatus report that the trace was stopped
3154 with a command. The effect is similar to setting the variable
3157 * Tracepoints can now be enabled and disabled at any time after a trace
3158 experiment has been started using the standard "enable" and "disable"
3159 commands. It is now possible to start a trace experiment with no enabled
3160 tracepoints; GDB will display a warning, but will allow the experiment to
3161 begin, assuming that tracepoints will be enabled as needed while the trace
3164 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3165 locations with 4-byte instructions, when they were previously
3166 limited to locations with instructions of 5 bytes or longer.
3170 set debug dwarf2-read
3171 show debug dwarf2-read
3172 Turns on or off display of debugging messages related to reading
3173 DWARF debug info. The default is off.
3175 set debug symtab-create
3176 show debug symtab-create
3177 Turns on or off display of debugging messages related to symbol table
3178 creation. The default is off.
3181 show extended-prompt
3182 Set the GDB prompt, and allow escape sequences to be inserted to
3183 display miscellaneous information (see 'help set extended-prompt'
3184 for the list of sequences). This prompt (and any information
3185 accessed through the escape sequences) is updated every time the
3186 prompt is displayed.
3188 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3189 show print entry-values
3190 Set printing of frame argument values at function entry. In some cases
3191 GDB can determine the value of function argument which was passed by the
3192 function caller, even if the value was modified inside the called function.
3194 set debug entry-values
3195 show debug entry-values
3196 Control display of debugging info for determining frame argument values at
3197 function entry and virtual tail call frames.
3199 set basenames-may-differ
3200 show basenames-may-differ
3201 Set whether a source file may have multiple base names.
3202 (A "base name" is the name of a file with the directory part removed.
3203 Example: The base name of "/home/user/hello.c" is "hello.c".)
3204 If set, GDB will canonicalize file names (e.g., expand symlinks)
3205 before comparing them. Canonicalization is an expensive operation,
3206 but it allows the same file be known by more than one base name.
3207 If not set (the default), all source files are assumed to have just
3208 one base name, and gdb will do file name comparisons more efficiently.
3214 Set a user name and notes for the current and any future trace runs.
3215 This is useful for long-running and/or disconnected traces, to
3216 inform others (or yourself) as to who is running the trace, supply
3217 contact information, or otherwise explain what is going on.
3219 set trace-stop-notes
3220 show trace-stop-notes
3221 Set a note attached to the trace run, that is displayed when the
3222 trace has been stopped by a tstop command. This is useful for
3223 instance as an explanation, if you are stopping a trace run that was
3224 started by someone else.
3226 * New remote packets
3230 Dynamically enable a tracepoint in a started trace experiment.
3234 Dynamically disable a tracepoint in a started trace experiment.
3238 Set the user and notes of the trace run.
3242 Query the current status of a tracepoint.
3246 Query the minimum length of instruction at which a fast tracepoint may
3249 * Dcache size (number of lines) and line-size are now runtime-configurable
3250 via "set dcache line" and "set dcache line-size" commands.
3254 Texas Instruments TMS320C6x tic6x-*-*
3258 Renesas RL78 rl78-*-elf
3260 *** Changes in GDB 7.3.1
3262 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3264 *** Changes in GDB 7.3
3266 * GDB has a new command: "thread find [REGEXP]".
3267 It finds the thread id whose name, target id, or thread extra info
3268 matches the given regular expression.
3270 * The "catch syscall" command now works on mips*-linux* targets.
3272 * The -data-disassemble MI command now supports modes 2 and 3 for
3273 dumping the instruction opcodes.
3275 * New command line options
3277 -data-directory DIR Specify DIR as the "data-directory".
3278 This is mostly for testing purposes.
3280 * The "maint set python auto-load on|off" command has been renamed to
3281 "set auto-load-scripts on|off".
3283 * GDB has a new command: "set directories".
3284 It is like the "dir" command except that it replaces the
3285 source path list instead of augmenting it.
3287 * GDB now understands thread names.
3289 On GNU/Linux, "info threads" will display the thread name as set by
3290 prctl or pthread_setname_np.
3292 There is also a new command, "thread name", which can be used to
3293 assign a name internally for GDB to display.
3296 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3297 has been integrated into GDB.
3301 ** The function gdb.Write now accepts an optional keyword 'stream'.
3302 This keyword, when provided, will direct the output to either
3303 stdout, stderr, or GDB's logging output.
3305 ** Parameters can now be be sub-classed in Python, and in particular
3306 you may implement the get_set_doc and get_show_doc functions.
3307 This improves how Parameter set/show documentation is processed
3308 and allows for more dynamic content.
3310 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3311 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3312 have an is_valid method.
3314 ** Breakpoints can now be sub-classed in Python, and in particular
3315 you may implement a 'stop' function that is executed each time
3316 the inferior reaches that breakpoint.
3318 ** New function gdb.lookup_global_symbol looks up a global symbol.
3320 ** GDB values in Python are now callable if the value represents a
3321 function. For example, if 'some_value' represents a function that
3322 takes two integer parameters and returns a value, you can call
3323 that function like so:
3325 result = some_value (10,20)
3327 ** Module gdb.types has been added.
3328 It contains a collection of utilities for working with gdb.Types objects:
3329 get_basic_type, has_field, make_enum_dict.
3331 ** Module gdb.printing has been added.
3332 It contains utilities for writing and registering pretty-printers.
3333 New classes: PrettyPrinter, SubPrettyPrinter,
3334 RegexpCollectionPrettyPrinter.
3335 New function: register_pretty_printer.
3337 ** New commands "info pretty-printers", "enable pretty-printer" and
3338 "disable pretty-printer" have been added.
3340 ** gdb.parameter("directories") is now available.
3342 ** New function gdb.newest_frame returns the newest frame in the
3345 ** The gdb.InferiorThread class has a new "name" attribute. This
3346 holds the thread's name.
3348 ** Python Support for Inferior events.
3349 Python scripts can add observers to be notified of events
3350 occurring in the process being debugged.
3351 The following events are currently supported:
3352 - gdb.events.cont Continue event.
3353 - gdb.events.exited Inferior exited event.
3354 - gdb.events.stop Signal received, and Breakpoint hit events.
3358 ** GDB now puts template parameters in scope when debugging in an
3359 instantiation. For example, if you have:
3361 template<int X> int func (void) { return X; }
3363 then if you step into func<5>, "print X" will show "5". This
3364 feature requires proper debuginfo support from the compiler; it
3365 was added to GCC 4.5.
3367 ** The motion commands "next", "finish", "until", and "advance" now
3368 work better when exceptions are thrown. In particular, GDB will
3369 no longer lose control of the inferior; instead, the GDB will
3370 stop the inferior at the point at which the exception is caught.
3371 This functionality requires a change in the exception handling
3372 code that was introduced in GCC 4.5.
3374 * GDB now follows GCC's rules on accessing volatile objects when
3375 reading or writing target state during expression evaluation.
3376 One notable difference to prior behavior is that "print x = 0"
3377 no longer generates a read of x; the value of the assignment is
3378 now always taken directly from the value being assigned.
3380 * GDB now has some support for using labels in the program's source in
3381 linespecs. For instance, you can use "advance label" to continue
3382 execution to a label.
3384 * GDB now has support for reading and writing a new .gdb_index
3385 section. This section holds a fast index of DWARF debugging
3386 information and can be used to greatly speed up GDB startup and
3387 operation. See the documentation for `save gdb-index' for details.
3389 * The "watch" command now accepts an optional "-location" argument.
3390 When used, this causes GDB to watch the memory referred to by the
3391 expression. Such a watchpoint is never deleted due to it going out
3394 * GDB now supports thread debugging of core dumps on GNU/Linux.
3396 GDB now activates thread debugging using the libthread_db library
3397 when debugging GNU/Linux core dumps, similarly to when debugging
3398 live processes. As a result, when debugging a core dump file, GDB
3399 is now able to display pthread_t ids of threads. For example, "info
3400 threads" shows the same output as when debugging the process when it
3401 was live. In earlier releases, you'd see something like this:
3404 * 1 LWP 6780 main () at main.c:10
3406 While now you see this:
3409 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3411 It is also now possible to inspect TLS variables when debugging core
3414 When debugging a core dump generated on a machine other than the one
3415 used to run GDB, you may need to point GDB at the correct
3416 libthread_db library with the "set libthread-db-search-path"
3417 command. See the user manual for more details on this command.
3419 * When natively debugging programs on PowerPC BookE processors running
3420 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3421 which stop execution of the inferior whenever it executes an instruction
3422 at any address within the specified range. See the "PowerPC Embedded"
3423 section in the user manual for more details.
3425 * New features in the GDB remote stub, GDBserver
3427 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3428 and i686 LynxOS (version 5.x).
3430 ** GDBserver is now supported on Blackfin Linux.
3432 * New native configurations
3434 ia64 HP-UX ia64-*-hpux*
3438 Analog Devices, Inc. Blackfin Processor bfin-*
3440 * Ada task switching is now supported on sparc-elf targets when
3441 debugging a program using the Ravenscar Profile. For more information,
3442 see the "Tasking Support when using the Ravenscar Profile" section
3443 in the GDB user manual.
3445 * Guile support was removed.
3447 * New features in the GNU simulator
3449 ** The --map-info flag lists all known core mappings.
3451 ** CFI flashes may be simulated via the "cfi" device.
3453 *** Changes in GDB 7.2
3455 * Shared library support for remote targets by default
3457 When GDB is configured for a generic, non-OS specific target, like
3458 for example, --target=arm-eabi or one of the many *-*-elf targets,
3459 GDB now queries remote stubs for loaded shared libraries using the
3460 `qXfer:libraries:read' packet. Previously, shared library support
3461 was always disabled for such configurations.
3465 ** Argument Dependent Lookup (ADL)
3467 In C++ ADL lookup directs function search to the namespaces of its
3468 arguments even if the namespace has not been imported.
3478 Here the compiler will search for `foo' in the namespace of 'b'
3479 and find A::foo. GDB now supports this. This construct is commonly
3480 used in the Standard Template Library for operators.
3482 ** Improved User Defined Operator Support
3484 In addition to member operators, GDB now supports lookup of operators
3485 defined in a namespace and imported with a `using' directive, operators
3486 defined in the global scope, operators imported implicitly from an
3487 anonymous namespace, and the ADL operators mentioned in the previous
3489 GDB now also supports proper overload resolution for all the previously
3490 mentioned flavors of operators.
3492 ** static const class members
3494 Printing of static const class members that are initialized in the
3495 class definition has been fixed.
3497 * Windows Thread Information Block access.
3499 On Windows targets, GDB now supports displaying the Windows Thread
3500 Information Block (TIB) structure. This structure is visible either
3501 by using the new command `info w32 thread-information-block' or, by
3502 dereferencing the new convenience variable named `$_tlb', a
3503 thread-specific pointer to the TIB. This feature is also supported
3504 when remote debugging using GDBserver.
3506 * Static tracepoints
3508 Static tracepoints are calls in the user program into a tracing
3509 library. One such library is a port of the LTTng kernel tracer to
3510 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3511 When debugging with GDBserver, GDB now supports combining the GDB
3512 tracepoint machinery with such libraries. For example: the user can
3513 use GDB to probe a static tracepoint marker (a call from the user
3514 program into the tracing library) with the new "strace" command (see
3515 "New commands" below). This creates a "static tracepoint" in the
3516 breakpoint list, that can be manipulated with the same feature set
3517 as fast and regular tracepoints. E.g., collect registers, local and
3518 global variables, collect trace state variables, and define
3519 tracepoint conditions. In addition, the user can collect extra
3520 static tracepoint marker specific data, by collecting the new
3521 $_sdata internal variable. When analyzing the trace buffer, you can
3522 inspect $_sdata like any other variable available to GDB. For more
3523 information, see the "Tracepoints" chapter in GDB user manual. New
3524 remote packets have been defined to support static tracepoints, see
3525 the "New remote packets" section below.
3527 * Better reconstruction of tracepoints after disconnected tracing
3529 GDB will attempt to download the original source form of tracepoint
3530 definitions when starting a trace run, and then will upload these
3531 upon reconnection to the target, resulting in a more accurate
3532 reconstruction of the tracepoints that are in use on the target.
3536 You can now exercise direct control over the ways that GDB can
3537 affect your program. For instance, you can disallow the setting of
3538 breakpoints, so that the program can run continuously (assuming
3539 non-stop mode). In addition, the "observer" variable is available
3540 to switch all of the different controls; in observer mode, GDB
3541 cannot affect the target's behavior at all, which is useful for
3542 tasks like diagnosing live systems in the field.
3544 * The new convenience variable $_thread holds the number of the
3547 * New remote packets
3551 Return the address of the Windows Thread Information Block of a given thread.
3555 In response to several of the tracepoint packets, the target may now
3556 also respond with a number of intermediate `qRelocInsn' request
3557 packets before the final result packet, to have GDB handle
3558 relocating an instruction to execute at a different address. This
3559 is particularly useful for stubs that support fast tracepoints. GDB
3560 reports support for this feature in the qSupported packet.
3564 List static tracepoint markers in the target program.
3568 List static tracepoint markers at a given address in the target
3571 qXfer:statictrace:read
3573 Read the static trace data collected (by a `collect $_sdata'
3574 tracepoint action). The remote stub reports support for this packet
3575 to gdb's qSupported query.
3579 Send the current settings of GDB's permission flags.
3583 Send part of the source (textual) form of a tracepoint definition,
3584 which includes location, conditional, and action list.
3586 * The source command now accepts a -s option to force searching for the
3587 script in the source search path even if the script name specifies
3590 * New features in the GDB remote stub, GDBserver
3592 - GDBserver now support tracepoints (including fast tracepoints, and
3593 static tracepoints). The feature is currently supported by the
3594 i386-linux and amd64-linux builds. See the "Tracepoints support
3595 in gdbserver" section in the manual for more information.
3597 GDBserver JIT compiles the tracepoint's conditional agent
3598 expression bytecode into native code whenever possible for low
3599 overhead dynamic tracepoints conditionals. For such tracepoints,
3600 an expression that examines program state is evaluated when the
3601 tracepoint is reached, in order to determine whether to capture
3602 trace data. If the condition is simple and false, processing the
3603 tracepoint finishes very quickly and no data is gathered.
3605 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3606 for static tracepoints support.
3608 - GDBserver now supports x86_64 Windows 64-bit debugging.
3610 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3611 it understands register description.
3613 * The --batch flag now disables pagination and queries.
3615 * X86 general purpose registers
3617 GDB now supports reading/writing byte, word and double-word x86
3618 general purpose registers directly. This means you can use, say,
3619 $ah or $ax to refer, respectively, to the byte register AH and
3620 16-bit word register AX that are actually portions of the 32-bit
3621 register EAX or 64-bit register RAX.
3623 * The `commands' command now accepts a range of breakpoints to modify.
3624 A plain `commands' following a command that creates multiple
3625 breakpoints affects all the breakpoints set by that command. This
3626 applies to breakpoints set by `rbreak', and also applies when a
3627 single `break' command creates multiple breakpoints (e.g.,
3628 breakpoints on overloaded c++ functions).
3630 * The `rbreak' command now accepts a filename specification as part of
3631 its argument, limiting the functions selected by the regex to those
3632 in the specified file.
3634 * Support for remote debugging Windows and SymbianOS shared libraries
3635 from Unix hosts has been improved. Non Windows GDB builds now can
3636 understand target reported file names that follow MS-DOS based file
3637 system semantics, such as file names that include drive letters and
3638 use the backslash character as directory separator. This makes it
3639 possible to transparently use the "set sysroot" and "set
3640 solib-search-path" on Unix hosts to point as host copies of the
3641 target's shared libraries. See the new command "set
3642 target-file-system-kind" described below, and the "Commands to
3643 specify files" section in the user manual for more information.
3647 eval template, expressions...
3648 Convert the values of one or more expressions under the control
3649 of the string template to a command line, and call it.
3651 set target-file-system-kind unix|dos-based|auto
3652 show target-file-system-kind
3653 Set or show the assumed file system kind for target reported file
3656 save breakpoints <filename>
3657 Save all current breakpoint definitions to a file suitable for use
3658 in a later debugging session. To read the saved breakpoint
3659 definitions, use the `source' command.
3661 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3664 info static-tracepoint-markers
3665 Display information about static tracepoint markers in the target.
3667 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3668 Define a static tracepoint by probing a marker at the given
3669 function, line, address, or marker ID.
3673 Enable and disable observer mode.
3675 set may-write-registers on|off
3676 set may-write-memory on|off
3677 set may-insert-breakpoints on|off
3678 set may-insert-tracepoints on|off
3679 set may-insert-fast-tracepoints on|off
3680 set may-interrupt on|off
3681 Set individual permissions for GDB effects on the target. Note that
3682 some of these settings can have undesirable or surprising
3683 consequences, particularly when changed in the middle of a session.
3684 For instance, disabling the writing of memory can prevent
3685 breakpoints from being inserted, cause single-stepping to fail, or
3686 even crash your program, if you disable after breakpoints have been
3687 inserted. However, GDB should not crash.
3689 set record memory-query on|off
3690 show record memory-query
3691 Control whether to stop the inferior if memory changes caused
3692 by an instruction cannot be recorded.
3697 The disassemble command now supports "start,+length" form of two arguments.
3701 ** GDB now provides a new directory location, called the python directory,
3702 where Python scripts written for GDB can be installed. The location
3703 of that directory is <data-directory>/python, where <data-directory>
3704 is the GDB data directory. For more details, see section `Scripting
3705 GDB using Python' in the manual.
3707 ** The GDB Python API now has access to breakpoints, symbols, symbol
3708 tables, program spaces, inferiors, threads and frame's code blocks.
3709 Additionally, GDB Parameters can now be created from the API, and
3710 manipulated via set/show in the CLI.
3712 ** New functions gdb.target_charset, gdb.target_wide_charset,
3713 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3715 ** New exception gdb.GdbError.
3717 ** Pretty-printers are now also looked up in the current program space.
3719 ** Pretty-printers can now be individually enabled and disabled.
3721 ** GDB now looks for names of Python scripts to auto-load in a
3722 special section named `.debug_gdb_scripts', in addition to looking
3723 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3725 * Tracepoint actions were unified with breakpoint commands. In particular,
3726 there are no longer differences in "info break" output for breakpoints and
3727 tracepoints and the "commands" command can be used for both tracepoints and
3728 regular breakpoints.
3732 ARM Symbian arm*-*-symbianelf*
3734 * D language support.
3735 GDB now supports debugging programs written in the D programming
3738 * GDB now supports the extended ptrace interface for PowerPC which is
3739 available since Linux kernel version 2.6.34. This automatically enables
3740 any hardware breakpoints and additional hardware watchpoints available in
3741 the processor. The old ptrace interface exposes just one hardware
3742 watchpoint and no hardware breakpoints.
3744 * GDB is now able to use the Data Value Compare (DVC) register available on
3745 embedded PowerPC processors to implement in hardware simple watchpoint
3746 conditions of the form:
3748 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3750 This works in native GDB running on Linux kernels with the extended ptrace
3751 interface mentioned above.
3753 *** Changes in GDB 7.1
3757 ** Namespace Support
3759 GDB now supports importing of namespaces in C++. This enables the
3760 user to inspect variables from imported namespaces. Support for
3761 namepace aliasing has also been added. So, if a namespace is
3762 aliased in the current scope (e.g. namepace C=A; ) the user can
3763 print variables using the alias (e.g. (gdb) print C::x).
3767 All known bugs relating to the printing of virtual base class were
3768 fixed. It is now possible to call overloaded static methods using a
3773 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3774 and reinterpret_cast<> are now handled by the C++ expression parser.
3778 Xilinx MicroBlaze microblaze-*-*
3783 Xilinx MicroBlaze microblaze
3786 * Multi-program debugging.
3788 GDB now has support for multi-program (a.k.a. multi-executable or
3789 multi-exec) debugging. This allows for debugging multiple inferiors
3790 simultaneously each running a different program under the same GDB
3791 session. See "Debugging Multiple Inferiors and Programs" in the
3792 manual for more information. This implied some user visible changes
3793 in the multi-inferior support. For example, "info inferiors" now
3794 lists inferiors that are not running yet or that have exited
3795 already. See also "New commands" and "New options" below.
3797 * New tracing features
3799 GDB's tracepoint facility now includes several new features:
3801 ** Trace state variables
3803 GDB tracepoints now include support for trace state variables, which
3804 are variables managed by the target agent during a tracing
3805 experiment. They are useful for tracepoints that trigger each
3806 other, so for instance one tracepoint can count hits in a variable,
3807 and then a second tracepoint has a condition that is true when the
3808 count reaches a particular value. Trace state variables share the
3809 $-syntax of GDB convenience variables, and can appear in both
3810 tracepoint actions and condition expressions. Use the "tvariable"
3811 command to create, and "info tvariables" to view; see "Trace State
3812 Variables" in the manual for more detail.
3816 GDB now includes an option for defining fast tracepoints, which
3817 targets may implement more efficiently, such as by installing a jump
3818 into the target agent rather than a trap instruction. The resulting
3819 speedup can be by two orders of magnitude or more, although the
3820 tradeoff is that some program locations on some target architectures
3821 might not allow fast tracepoint installation, for instance if the
3822 instruction to be replaced is shorter than the jump. To request a
3823 fast tracepoint, use the "ftrace" command, with syntax identical to
3824 the regular trace command.
3826 ** Disconnected tracing
3828 It is now possible to detach GDB from the target while it is running
3829 a trace experiment, then reconnect later to see how the experiment
3830 is going. In addition, a new variable disconnected-tracing lets you
3831 tell the target agent whether to continue running a trace if the
3832 connection is lost unexpectedly.
3836 GDB now has the ability to save the trace buffer into a file, and
3837 then use that file as a target, similarly to you can do with
3838 corefiles. You can select trace frames, print data that was
3839 collected in them, and use tstatus to display the state of the
3840 tracing run at the moment that it was saved. To create a trace
3841 file, use "tsave <filename>", and to use it, do "target tfile
3844 ** Circular trace buffer
3846 You can ask the target agent to handle the trace buffer as a
3847 circular buffer, discarding the oldest trace frames to make room for
3848 newer ones, by setting circular-trace-buffer to on. This feature may
3849 not be available for all target agents.
3854 The disassemble command, when invoked with two arguments, now requires
3855 the arguments to be comma-separated.
3858 The info variables command now displays variable definitions. Files
3859 which only declare a variable are not shown.
3862 The source command is now capable of sourcing Python scripts.
3863 This feature is dependent on the debugger being build with Python
3866 Related to this enhancement is also the introduction of a new command
3867 "set script-extension" (see below).
3869 * New commands (for set/show, see "New options" below)
3871 record save [<FILENAME>]
3872 Save a file (in core file format) containing the process record
3873 execution log for replay debugging at a later time.
3875 record restore <FILENAME>
3876 Restore the process record execution log that was saved at an
3877 earlier time, for replay debugging.
3879 add-inferior [-copies <N>] [-exec <FILENAME>]
3882 clone-inferior [-copies <N>] [ID]
3883 Make a new inferior ready to execute the same program another
3884 inferior has loaded.
3889 maint info program-spaces
3890 List the program spaces loaded into GDB.
3892 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3893 show remote interrupt-sequence
3894 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3895 as the sequence to the remote target in order to interrupt the execution.
3896 Ctrl-C is a default. Some system prefers BREAK which is high level of
3897 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3898 Magic SysRq g. It is BREAK signal and character 'g'.
3900 set remote interrupt-on-connect [on | off]
3901 show remote interrupt-on-connect
3902 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3903 remote target when gdb connects to it. This is needed when you debug
3906 set remotebreak [on | off]
3908 Deprecated. Use "set/show remote interrupt-sequence" instead.
3910 tvariable $NAME [ = EXP ]
3911 Create or modify a trace state variable.
3914 List trace state variables and their values.
3916 delete tvariable $NAME ...
3917 Delete one or more trace state variables.
3920 Evaluate the given expressions without collecting anything into the
3921 trace buffer. (Valid in tracepoint actions only.)
3923 ftrace FN / FILE:LINE / *ADDR
3924 Define a fast tracepoint at the given function, line, or address.
3926 * New expression syntax
3928 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3929 GDB now parses 0b101010 identically with 42.
3933 set follow-exec-mode new|same
3934 show follow-exec-mode
3935 Control whether GDB reuses the same inferior across an exec call or
3936 creates a new one. This is useful to be able to restart the old
3937 executable after the inferior having done an exec call.
3939 set default-collect EXPR, ...
3940 show default-collect
3941 Define a list of expressions to be collected at each tracepoint.
3942 This is a useful way to ensure essential items are not overlooked,
3943 such as registers or a critical global variable.
3945 set disconnected-tracing
3946 show disconnected-tracing
3947 If set to 1, the target is instructed to continue tracing if it
3948 loses its connection to GDB. If 0, the target is to stop tracing
3951 set circular-trace-buffer
3952 show circular-trace-buffer
3953 If set to on, the target is instructed to use a circular trace buffer
3954 and discard the oldest trace frames instead of stopping the trace due
3955 to a full trace buffer. If set to off, the trace stops when the buffer
3956 fills up. Some targets may not support this.
3958 set script-extension off|soft|strict
3959 show script-extension
3960 If set to "off", the debugger does not perform any script language
3961 recognition, and all sourced files are assumed to be GDB scripts.
3962 If set to "soft" (the default), files are sourced according to
3963 filename extension, falling back to GDB scripts if the first
3965 If set to "strict", files are sourced according to filename extension.
3967 set ada trust-PAD-over-XVS on|off
3968 show ada trust-PAD-over-XVS
3969 If off, activate a workaround against a bug in the debugging information
3970 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3971 the GCC sources for more information about the GNAT encoding and
3972 PAD types in particular). It is always safe to set this option to
3973 off, but this introduces a slight performance penalty. The default
3976 * Python API Improvements
3978 ** GDB provides the new class gdb.LazyString. This is useful in
3979 some pretty-printing cases. The new method gdb.Value.lazy_string
3980 provides a simple way to create objects of this type.
3982 ** The fields returned by gdb.Type.fields now have an
3983 `is_base_class' attribute.
3985 ** The new method gdb.Type.range returns the range of an array type.
3987 ** The new method gdb.parse_and_eval can be used to parse and
3988 evaluate an expression.
3990 * New remote packets
3993 Define a trace state variable.
3996 Get the current value of a trace state variable.
3999 Set desired tracing behavior upon disconnection.
4002 Set the trace buffer to be linear or circular.
4005 Get data about the tracepoints currently in use.
4009 Process record now works correctly with hardware watchpoints.
4011 Multiple bug fixes have been made to the mips-irix port, making it
4012 much more reliable. In particular:
4013 - Debugging threaded applications is now possible again. Previously,
4014 GDB would hang while starting the program, or while waiting for
4015 the program to stop at a breakpoint.
4016 - Attaching to a running process no longer hangs.
4017 - An error occurring while loading a core file has been fixed.
4018 - Changing the value of the PC register now works again. This fixes
4019 problems observed when using the "jump" command, or when calling
4020 a function from GDB, or even when assigning a new value to $pc.
4021 - With the "finish" and "return" commands, the return value for functions
4022 returning a small array is now correctly printed.
4023 - It is now possible to break on shared library code which gets executed
4024 during a shared library init phase (code executed while executing
4025 their .init section). Previously, the breakpoint would have no effect.
4026 - GDB is now able to backtrace through the signal handler for
4027 non-threaded programs.
4029 PIE (Position Independent Executable) programs debugging is now supported.
4030 This includes debugging execution of PIC (Position Independent Code) shared
4031 libraries although for that, it should be possible to run such libraries as an
4034 *** Changes in GDB 7.0
4036 * GDB now has an interface for JIT compilation. Applications that
4037 dynamically generate code can create symbol files in memory and register
4038 them with GDB. For users, the feature should work transparently, and
4039 for JIT developers, the interface is documented in the GDB manual in the
4040 "JIT Compilation Interface" chapter.
4042 * Tracepoints may now be conditional. The syntax is as for
4043 breakpoints; either an "if" clause appended to the "trace" command,
4044 or the "condition" command is available. GDB sends the condition to
4045 the target for evaluation using the same bytecode format as is used
4046 for tracepoint actions.
4048 * The disassemble command now supports: an optional /r modifier, print the
4049 raw instructions in hex as well as in symbolic form, and an optional /m
4050 modifier to print mixed source+assembly.
4052 * Process record and replay
4054 In a architecture environment that supports ``process record and
4055 replay'', ``process record and replay'' target can record a log of
4056 the process execution, and replay it with both forward and reverse
4059 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4060 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4061 set execution-direction {forward|reverse}, for targets that support
4064 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4065 feature is available with a native GDB running on kernel version
4068 * GDB now has support for multi-byte and wide character sets on the
4069 target. Strings whose character type is wchar_t, char16_t, or
4070 char32_t are now correctly printed. GDB supports wide- and unicode-
4071 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4072 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4073 `printf'. This feature requires iconv to work properly; if your
4074 system does not have a working iconv, GDB can use GNU libiconv. See
4075 the installation instructions for more information.
4077 * GDB now supports automatic retrieval of shared library files from
4078 remote targets. To use this feature, specify a system root that begins
4079 with the `remote:' prefix, either via the `set sysroot' command or via
4080 the `--with-sysroot' configure-time option.
4082 * "info sharedlibrary" now takes an optional regex of libraries to show,
4083 and it now reports if a shared library has no debugging information.
4085 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4086 now complete on file names.
4088 * When completing in expressions, gdb will attempt to limit
4089 completions to allowable structure or union fields, where appropriate.
4090 For instance, consider:
4092 # struct example { int f1; double f2; };
4093 # struct example variable;
4096 If the user types TAB at the end of this command line, the available
4097 completions will be "f1" and "f2".
4099 * Inlined functions are now supported. They show up in backtraces, and
4100 the "step", "next", and "finish" commands handle them automatically.
4102 * GDB now supports the token-splicing (##) and stringification (#)
4103 operators when expanding macros. It also supports variable-arity
4106 * GDB now supports inspecting extra signal information, exported by
4107 the new $_siginfo convenience variable. The feature is currently
4108 implemented on linux ARM, i386 and amd64.
4110 * GDB can now display the VFP floating point registers and NEON vector
4111 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4112 can provide these registers (requires Linux 2.6.30 or later). Remote
4113 and simulator targets may also provide them.
4115 * New remote packets
4118 Search memory for a sequence of bytes.
4121 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4122 operation over reliable transport links. Use of this packet is
4123 controlled by the `set remote noack-packet' command.
4126 Kill the process with the specified process ID. Use this in preference
4127 to `k' when multiprocess protocol extensions are supported.
4130 Obtains additional operating system information
4134 Read or write additional signal information.
4136 * Removed remote protocol undocumented extension
4138 An undocumented extension to the remote protocol's `S' stop reply
4139 packet that permited the stub to pass a process id was removed.
4140 Remote servers should use the `T' stop reply packet instead.
4142 * GDB now supports multiple function calling conventions according to the
4143 DWARF-2 DW_AT_calling_convention function attribute.
4145 * The SH target utilizes the aforementioned change to distinguish between gcc
4146 and Renesas calling convention. It also adds the new CLI commands
4147 `set/show sh calling-convention'.
4149 * GDB can now read compressed debug sections, as produced by GNU gold
4150 with the --compress-debug-sections=zlib flag.
4152 * 64-bit core files are now supported on AIX.
4154 * Thread switching is now supported on Tru64.
4156 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4157 which will be allocated using malloc later in program execution.
4159 * The qXfer:libraries:read remote procotol packet now allows passing a
4160 list of section offsets.
4162 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4163 conditions handling signals delivered during attach or thread creation
4164 have also been fixed.
4166 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4167 From the user's standpoint, all unqualified instances of True and False
4168 are treated as the standard definitions, regardless of context.
4170 * GDB now parses C++ symbol and type names more flexibly. For
4173 template<typename T> class C { };
4176 GDB will now correctly handle all of:
4178 ptype C<char const *>
4179 ptype C<char const*>
4180 ptype C<const char *>
4181 ptype C<const char*>
4183 * New features in the GDB remote stub, gdbserver
4185 - The "--wrapper" command-line argument tells gdbserver to use a
4186 wrapper program to launch programs for debugging.
4188 - On PowerPC and S/390 targets, it is now possible to use a single
4189 gdbserver executable to debug both 32-bit and 64-bit programs.
4190 (This requires gdbserver itself to be built as a 64-bit executable.)
4192 - gdbserver uses the new noack protocol mode for TCP connections to
4193 reduce communications latency, if also supported and enabled in GDB.
4195 - Support for the sparc64-linux-gnu target is now included in
4198 - The amd64-linux build of gdbserver now supports debugging both
4199 32-bit and 64-bit programs.
4201 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4202 now support hardware watchpoints, and will use them automatically
4207 GDB now has support for scripting using Python. Whether this is
4208 available is determined at configure time.
4210 New GDB commands can now be written in Python.
4212 * Ada tasking support
4214 Ada tasks can now be inspected in GDB. The following commands have
4218 Print the list of Ada tasks.
4220 Print detailed information about task number N.
4222 Print the task number of the current task.
4224 Switch the context of debugging to task number N.
4226 * Support for user-defined prefixed commands. The "define" command can
4227 add new commands to existing prefixes, e.g. "target".
4229 * Multi-inferior, multi-process debugging.
4231 GDB now has generalized support for multi-inferior debugging. See
4232 "Debugging Multiple Inferiors" in the manual for more information.
4233 Although availability still depends on target support, the command
4234 set is more uniform now. The GNU/Linux specific multi-forks support
4235 has been migrated to this new framework. This implied some user
4236 visible changes; see "New commands" and also "Removed commands"
4239 * Target descriptions can now describe the target OS ABI. See the
4240 "Target Description Format" section in the user manual for more
4243 * Target descriptions can now describe "compatible" architectures
4244 to indicate that the target can execute applications for a different
4245 architecture in addition to those for the main target architecture.
4246 See the "Target Description Format" section in the user manual for
4249 * Multi-architecture debugging.
4251 GDB now includes general supports for debugging applications on
4252 hybrid systems that use more than one single processor architecture
4253 at the same time. Each such hybrid architecture still requires
4254 specific support to be added. The only hybrid architecture supported
4255 in this version of GDB is the Cell Broadband Engine.
4257 * GDB now supports integrated debugging of Cell/B.E. applications that
4258 use both the PPU and SPU architectures. To enable support for hybrid
4259 Cell/B.E. debugging, you need to configure GDB to support both the
4260 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4261 --enable-targets configure option.
4263 * Non-stop mode debugging.
4265 For some targets, GDB now supports an optional mode of operation in
4266 which you can examine stopped threads while other threads continue
4267 to execute freely. This is referred to as non-stop mode, with the
4268 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4269 section in the user manual for more information.
4271 To be able to support remote non-stop debugging, a remote stub needs
4272 to implement the non-stop mode remote protocol extensions, as
4273 described in the "Remote Non-Stop" section of the user manual. The
4274 GDB remote stub, gdbserver, has been adjusted to support these
4275 extensions on linux targets.
4277 * New commands (for set/show, see "New options" below)
4279 catch syscall [NAME(S) | NUMBER(S)]
4280 Catch system calls. Arguments, which should be names of system
4281 calls or their numbers, mean catch only those syscalls. Without
4282 arguments, every syscall will be caught. When the inferior issues
4283 any of the specified syscalls, GDB will stop and announce the system
4284 call, both when it is called and when its call returns. This
4285 feature is currently available with a native GDB running on the
4286 Linux Kernel, under the following architectures: x86, x86_64,
4287 PowerPC and PowerPC64.
4289 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4291 Search memory for a sequence of bytes.
4293 maint set python print-stack
4294 maint show python print-stack
4295 Show a stack trace when an error is encountered in a Python script.
4298 Invoke CODE by passing it to the Python interpreter.
4303 These allow macros to be defined, undefined, and listed
4307 Show operating system information about processes.
4310 List the inferiors currently under GDB's control.
4313 Switch focus to inferior number NUM.
4316 Detach from inferior number NUM.
4319 Kill inferior number NUM.
4323 set spu stop-on-load
4324 show spu stop-on-load
4325 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4327 set spu auto-flush-cache
4328 show spu auto-flush-cache
4329 Control whether to automatically flush the software-managed cache
4330 during Cell/B.E. debugging.
4332 set sh calling-convention
4333 show sh calling-convention
4334 Control the calling convention used when calling SH target functions.
4337 show debug timestamp
4338 Control display of timestamps with GDB debugging output.
4340 set disassemble-next-line
4341 show disassemble-next-line
4342 Control display of disassembled source lines or instructions when
4345 set remote noack-packet
4346 show remote noack-packet
4347 Set/show the use of remote protocol QStartNoAckMode packet. See above
4348 under "New remote packets."
4350 set remote query-attached-packet
4351 show remote query-attached-packet
4352 Control use of remote protocol `qAttached' (query-attached) packet.
4354 set remote read-siginfo-object
4355 show remote read-siginfo-object
4356 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4359 set remote write-siginfo-object
4360 show remote write-siginfo-object
4361 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4364 set remote reverse-continue
4365 show remote reverse-continue
4366 Control use of remote protocol 'bc' (reverse-continue) packet.
4368 set remote reverse-step
4369 show remote reverse-step
4370 Control use of remote protocol 'bs' (reverse-step) packet.
4372 set displaced-stepping
4373 show displaced-stepping
4374 Control displaced stepping mode. Displaced stepping is a way to
4375 single-step over breakpoints without removing them from the debuggee.
4376 Also known as "out-of-line single-stepping".
4379 show debug displaced
4380 Control display of debugging info for displaced stepping.
4382 maint set internal-error
4383 maint show internal-error
4384 Control what GDB does when an internal error is detected.
4386 maint set internal-warning
4387 maint show internal-warning
4388 Control what GDB does when an internal warning is detected.
4393 Use a wrapper program to launch programs for debugging.
4395 set multiple-symbols (all|ask|cancel)
4396 show multiple-symbols
4397 The value of this variable can be changed to adjust the debugger behavior
4398 when an expression or a breakpoint location contains an ambiguous symbol
4399 name (an overloaded function name, for instance).
4401 set breakpoint always-inserted
4402 show breakpoint always-inserted
4403 Keep breakpoints always inserted in the target, as opposed to inserting
4404 them when resuming the target, and removing them when the target stops.
4405 This option can improve debugger performance on slow remote targets.
4407 set arm fallback-mode (arm|thumb|auto)
4408 show arm fallback-mode
4409 set arm force-mode (arm|thumb|auto)
4411 These commands control how ARM GDB determines whether instructions
4412 are ARM or Thumb. The default for both settings is auto, which uses
4413 the current CPSR value for instructions without symbols; previous
4414 versions of GDB behaved as if "set arm fallback-mode arm".
4416 set disable-randomization
4417 show disable-randomization
4418 Standalone programs run with the virtual address space randomization enabled
4419 by default on some platforms. This option keeps the addresses stable across
4420 multiple debugging sessions.
4424 Control whether other threads are stopped or not when some thread hits
4429 Requests that asynchronous execution is enabled in the target, if available.
4430 In this case, it's possible to resume target in the background, and interact
4431 with GDB while the target is running. "show target-async" displays the
4432 current state of asynchronous execution of the target.
4434 set target-wide-charset
4435 show target-wide-charset
4436 The target-wide-charset is the name of the character set that GDB
4437 uses when printing characters whose type is wchar_t.
4439 set tcp auto-retry (on|off)
4441 set tcp connect-timeout
4442 show tcp connect-timeout
4443 These commands allow GDB to retry failed TCP connections to a remote stub
4444 with a specified timeout period; this is useful if the stub is launched
4445 in parallel with GDB but may not be ready to accept connections immediately.
4447 set libthread-db-search-path
4448 show libthread-db-search-path
4449 Control list of directories which GDB will search for appropriate
4452 set schedule-multiple (on|off)
4453 show schedule-multiple
4454 Allow GDB to resume all threads of all processes or only threads of
4455 the current process.
4459 Use more aggressive caching for accesses to the stack. This improves
4460 performance of remote debugging (particularly backtraces) without
4461 affecting correctness.
4463 set interactive-mode (on|off|auto)
4464 show interactive-mode
4465 Control whether GDB runs in interactive mode (on) or not (off).
4466 When in interactive mode, GDB waits for the user to answer all
4467 queries. Otherwise, GDB does not wait and assumes the default
4468 answer. When set to auto (the default), GDB determines which
4469 mode to use based on the stdin settings.
4474 For program forks, this is replaced by the new more generic `info
4475 inferiors' command. To list checkpoints, you can still use the
4476 `info checkpoints' command, which was an alias for the `info forks'
4480 Replaced by the new `inferior' command. To switch between
4481 checkpoints, you can still use the `restart' command, which was an
4482 alias for the `fork' command.
4485 This is removed, since some targets don't have a notion of
4486 processes. To switch between processes, you can still use the
4487 `inferior' command using GDB's own inferior number.
4490 For program forks, this is replaced by the new more generic `kill
4491 inferior' command. To delete a checkpoint, you can still use the
4492 `delete checkpoint' command, which was an alias for the `delete
4496 For program forks, this is replaced by the new more generic `detach
4497 inferior' command. To detach a checkpoint, you can still use the
4498 `detach checkpoint' command, which was an alias for the `detach
4501 * New native configurations
4503 x86/x86_64 Darwin i[34567]86-*-darwin*
4505 x86_64 MinGW x86_64-*-mingw*
4509 Lattice Mico32 lm32-*
4510 x86 DICOS i[34567]86-*-dicos*
4511 x86_64 DICOS x86_64-*-dicos*
4514 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4515 (mingw32ce) debugging.
4521 These commands were actually not implemented on any target.
4523 *** Changes in GDB 6.8
4525 * New native configurations
4527 NetBSD/hppa hppa*-*netbsd*
4528 Xtensa GNU/Linux xtensa*-*-linux*
4532 NetBSD/hppa hppa*-*-netbsd*
4533 Xtensa GNU/Lunux xtensa*-*-linux*
4535 * Change in command line behavior -- corefiles vs. process ids.
4537 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4538 attaching to process NUMBER fails, GDB no longer attempts to open a
4539 core file named NUMBER. Attaching to a program using the -c option
4540 is no longer supported. Instead, use the '-p' or '--pid' options.
4542 * GDB can now be built as a native debugger for debugging Windows x86
4543 (mingw32) Portable Executable (PE) programs.
4545 * Pending breakpoints no longer change their number when their address
4548 * GDB now supports breakpoints with multiple locations,
4549 including breakpoints on C++ constructors, inside C++ templates,
4550 and in inlined functions.
4552 * GDB's ability to debug optimized code has been improved. GDB more
4553 accurately identifies function bodies and lexical blocks that occupy
4554 more than one contiguous range of addresses.
4556 * Target descriptions can now describe registers for PowerPC.
4558 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4559 registers on PowerPC targets.
4561 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4562 targets even when the libthread_db library is not available.
4564 * The GDB remote stub, gdbserver, now supports the new file transfer
4565 commands (remote put, remote get, and remote delete).
4567 * The GDB remote stub, gdbserver, now supports run and attach in
4568 extended-remote mode.
4570 * hppa*64*-*-hpux11* target broken
4571 The debugger is unable to start a program and fails with the following
4572 error: "Error trying to get information about dynamic linker".
4573 The gdb-6.7 release is also affected.
4575 * GDB now supports the --enable-targets= configure option to allow
4576 building a single GDB executable that supports multiple remote
4577 target architectures.
4579 * GDB now supports debugging C and C++ programs which use the
4580 Decimal Floating Point extension. In addition, the PowerPC target
4581 now has a set of pseudo-registers to inspect decimal float values
4582 stored in two consecutive float registers.
4584 * The -break-insert MI command can optionally create pending
4587 * Improved support for debugging Ada
4588 Many improvements to the Ada language support have been made. These
4590 - Better support for Ada2005 interface types
4591 - Improved handling of arrays and slices in general
4592 - Better support for Taft-amendment types
4593 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4595 - Improved command completion in Ada
4598 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4603 set print frame-arguments (all|scalars|none)
4604 show print frame-arguments
4605 The value of this variable can be changed to control which argument
4606 values should be printed by the debugger when displaying a frame.
4611 Transfer files to and from a remote target, and delete remote files.
4618 Transfer files to and from a remote target, and delete remote files.
4620 * New remote packets
4627 Open, close, read, write, and delete files on the remote system.
4630 Attach to an existing process on the remote system, in extended-remote
4634 Run a new process on the remote system, in extended-remote mode.
4636 *** Changes in GDB 6.7
4638 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4639 bfd, libiberty and opcodes, as revealed by static analysis donated by
4640 Coverity, Inc. (http://scan.coverity.com).
4642 * When looking up multiply-defined global symbols, GDB will now prefer the
4643 symbol definition in the current shared library if it was built using the
4644 -Bsymbolic linker option.
4646 * When the Text User Interface (TUI) is not configured, GDB will now
4647 recognize the -tui command-line option and print a message that the TUI
4650 * The GDB remote stub, gdbserver, now has lower overhead for high
4651 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4653 * GDB for MIPS targets now autodetects whether a remote target provides
4654 32-bit or 64-bit register values.
4656 * Support for C++ member pointers has been improved.
4658 * GDB now understands XML target descriptions, which specify the
4659 target's overall architecture. GDB can read a description from
4660 a local file or over the remote serial protocol.
4662 * Vectors of single-byte data use a new integer type which is not
4663 automatically displayed as character or string data.
4665 * The /s format now works with the print command. It displays
4666 arrays of single-byte integers and pointers to single-byte integers
4669 * Target descriptions can now describe target-specific registers,
4670 for architectures which have implemented the support (currently
4671 only ARM, M68K, and MIPS).
4673 * GDB and the GDB remote stub, gdbserver, now support the XScale
4676 * The GDB remote stub, gdbserver, has been updated to support
4677 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4678 has been rewritten to use the standard GDB remote protocol.
4680 * GDB can now step into C++ functions which are called through thunks.
4682 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4684 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4685 layout. It also supports a TextSeg= and DataSeg= response when only
4686 segment base addresses (rather than offsets) are available.
4688 * The /i format now outputs any trailing branch delay slot instructions
4689 immediately following the last instruction within the count specified.
4691 * The GDB remote protocol "T" stop reply packet now supports a
4692 "library" response. Combined with the new "qXfer:libraries:read"
4693 packet, this response allows GDB to debug shared libraries on targets
4694 where the operating system manages the list of loaded libraries (e.g.
4695 Windows and SymbianOS).
4697 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4698 (DLLs) on Windows and Windows CE targets.
4700 * GDB now supports a faster verification that a .debug file matches its binary
4701 according to its build-id signature, if the signature is present.
4707 Enable or disable hardware flow control (RTS/CTS) on the serial port
4708 when debugging using remote targets.
4710 set mem inaccessible-by-default
4711 show mem inaccessible-by-default
4712 If the target supplies a memory map, for instance via the remote
4713 protocol's "qXfer:memory-map:read" packet, setting this variable
4714 prevents GDB from accessing memory outside the memory map. This
4715 is useful for targets with memory mapped registers or which react
4716 badly to accesses of unmapped address space.
4718 set breakpoint auto-hw
4719 show breakpoint auto-hw
4720 If the target supplies a memory map, for instance via the remote
4721 protocol's "qXfer:memory-map:read" packet, setting this variable
4722 lets GDB use hardware breakpoints automatically for memory regions
4723 where it can not use software breakpoints. This covers both the
4724 "break" command and internal breakpoints used for other commands
4725 including "next" and "finish".
4728 catch exception unhandled
4729 Stop the program execution when Ada exceptions are raised.
4732 Stop the program execution when an Ada assertion failed.
4736 Set an alternate system root for target files. This is a more
4737 general version of "set solib-absolute-prefix", which is now
4738 an alias to "set sysroot".
4741 Provide extended SPU facility status information. This set of
4742 commands is available only when debugging the Cell/B.E. SPU
4745 * New native configurations
4747 OpenBSD/sh sh*-*openbsd*
4750 unset tdesc filename
4752 Use the specified local file as an XML target description, and do
4753 not query the target for its built-in description.
4757 OpenBSD/sh sh*-*-openbsd*
4758 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4759 Toshiba Media Processor mep-elf
4761 * New remote packets
4764 Ignore the specified signals; pass them directly to the debugged program
4765 without stopping other threads or reporting them to GDB.
4767 qXfer:features:read:
4768 Read an XML target description from the target, which describes its
4773 Read or write contents of an spufs file on the target system. These
4774 packets are available only on the Cell/B.E. SPU architecture.
4776 qXfer:libraries:read:
4777 Report the loaded shared libraries. Combined with new "T" packet
4778 response, this packet allows GDB to debug shared libraries on
4779 targets where the operating system manages the list of loaded
4780 libraries (e.g. Windows and SymbianOS).
4784 Support for these obsolete configurations has been removed.
4792 i[34567]86-*-lynxos*
4793 i[34567]86-*-netware*
4794 i[34567]86-*-sco3.2v5*
4795 i[34567]86-*-sco3.2v4*
4797 i[34567]86-*-sysv4.2*
4800 i[34567]86-*-unixware2*
4801 i[34567]86-*-unixware*
4810 * Other removed features
4817 Various m68k-only ROM monitors.
4824 Various Renesas ROM monitors and debugging interfaces for SH and
4829 Support for a Macraigor serial interface to on-chip debugging.
4830 GDB does not directly support the newer parallel or USB
4835 A debug information format. The predecessor to DWARF 2 and
4836 DWARF 3, which are still supported.
4838 Support for the HP aCC compiler on HP-UX/PA-RISC
4840 SOM-encapsulated symbolic debugging information, automatic
4841 invocation of pxdb, and the aCC custom C++ ABI. This does not
4842 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4843 with aCC can still be debugged on an assembly level.
4845 MIPS ".pdr" sections
4847 A MIPS-specific format used to describe stack frame layout
4848 in debugging information.
4852 GDB could work with an older version of Guile to debug
4853 the interpreter and Scheme programs running in it.
4855 set mips stack-arg-size
4856 set mips saved-gpreg-size
4858 Use "set mips abi" to control parameter passing for MIPS.
4860 *** Changes in GDB 6.6
4865 Cell Broadband Engine SPU spu-elf
4867 * GDB can now be configured as a cross-debugger targeting native Windows
4868 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4869 running on a Windows system over TCP/IP to debug Windows programs.
4871 * The GDB remote stub, gdbserver, has been updated to support Windows and
4872 Cygwin debugging. Both single-threaded and multi-threaded programs are
4875 * The "set trust-readonly-sections" command works again. This command was
4876 broken in GDB 6.3, 6.4, and 6.5.
4878 * The "load" command now supports writing to flash memory, if the remote
4879 stub provides the required support.
4881 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4882 longer requires symbolic debug information (e.g. DWARF-2).
4887 unset substitute-path
4888 show substitute-path
4889 Manage a list of substitution rules that GDB uses to rewrite the name
4890 of the directories where the sources are located. This can be useful
4891 for instance when the sources were moved to a different location
4892 between compilation and debugging.
4896 Print each CLI command as it is executed. Each command is prefixed with
4897 a number of `+' symbols representing the nesting depth.
4898 The source command now has a `-v' option to enable the same feature.
4902 The ARM Demon monitor support (RDP protocol, "target rdp").
4904 Kernel Object Display, an embedded debugging feature which only worked with
4905 an obsolete version of Cisco IOS.
4907 The 'set download-write-size' and 'show download-write-size' commands.
4909 * New remote packets
4912 Tell a stub about GDB client features, and request remote target features.
4913 The first feature implemented is PacketSize, which allows the target to
4914 specify the size of packets it can handle - to minimize the number of
4915 packets required and improve performance when connected to a remote
4919 Fetch an OS auxilliary vector from the remote stub. This packet is a
4920 more efficient replacement for qPart:auxv:read.
4922 qXfer:memory-map:read:
4923 Fetch a memory map from the remote stub, including information about
4924 RAM, ROM, and flash memory devices.
4929 Erase and program a flash memory device.
4931 * Removed remote packets
4934 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4935 used it, and only gdbserver implemented it.
4937 *** Changes in GDB 6.5
4941 Renesas M32C/M16C m32c-elf
4943 Morpho Technologies ms1 ms1-elf
4947 init-if-undefined Initialize a convenience variable, but
4948 only if it doesn't already have a value.
4950 The following commands are presently only implemented for native GNU/Linux:
4952 checkpoint Save a snapshot of the program state.
4954 restart <n> Return the program state to a
4955 previously saved state.
4957 info checkpoints List currently saved checkpoints.
4959 delete-checkpoint <n> Delete a previously saved checkpoint.
4961 set|show detach-on-fork Tell gdb whether to detach from a newly
4962 forked process, or to keep debugging it.
4964 info forks List forks of the user program that
4965 are available to be debugged.
4967 fork <n> Switch to debugging one of several
4968 forks of the user program that are
4969 available to be debugged.
4971 delete-fork <n> Delete a fork from the list of forks
4972 that are available to be debugged (and
4973 kill the forked process).
4975 detach-fork <n> Delete a fork from the list of forks
4976 that are available to be debugged (and
4977 allow the process to continue).
4981 Morpho Technologies ms2 ms1-elf
4983 * Improved Windows host support
4985 GDB now builds as a cross debugger hosted on i686-mingw32, including
4986 native console support, and remote communications using either
4987 network sockets or serial ports.
4989 * Improved Modula-2 language support
4991 GDB can now print most types in the Modula-2 syntax. This includes:
4992 basic types, set types, record types, enumerated types, range types,
4993 pointer types and ARRAY types. Procedure var parameters are correctly
4994 printed and hexadecimal addresses and character constants are also
4995 written in the Modula-2 syntax. Best results can be obtained by using
4996 GNU Modula-2 together with the -gdwarf-2 command line option.
5000 The ARM rdi-share module.
5002 The Netware NLM debug server.
5004 *** Changes in GDB 6.4
5006 * New native configurations
5008 OpenBSD/arm arm*-*-openbsd*
5009 OpenBSD/mips64 mips64-*-openbsd*
5013 Morpho Technologies ms1 ms1-elf
5015 * New command line options
5017 --batch-silent As for --batch, but totally silent.
5018 --return-child-result The debugger will exist with the same value
5019 the child (debugged) program exited with.
5020 --eval-command COMMAND, -ex COMMAND
5021 Execute a single GDB CLI command. This may be
5022 specified multiple times and in conjunction
5023 with the --command (-x) option.
5025 * Deprecated commands removed
5027 The following commands, that were deprecated in 2000, have been
5031 set|show arm disassembly-flavor set|show arm disassembler
5032 othernames set arm disassembler
5033 set|show remotedebug set|show debug remote
5034 set|show archdebug set|show debug arch
5035 set|show eventdebug set|show debug event
5038 * New BSD user-level threads support
5040 It is now possible to debug programs using the user-level threads
5041 library on OpenBSD and FreeBSD. Currently supported (target)
5044 FreeBSD/amd64 x86_64-*-freebsd*
5045 FreeBSD/i386 i386-*-freebsd*
5046 OpenBSD/i386 i386-*-openbsd*
5048 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5049 are not yet supported.
5051 * New support for Matsushita MN10300 w/sim added
5052 (Work in progress). mn10300-elf.
5054 * REMOVED configurations and files
5056 VxWorks and the XDR protocol *-*-vxworks
5057 Motorola MCORE mcore-*-*
5058 National Semiconductor NS32000 ns32k-*-*
5060 * New "set print array-indexes" command
5062 After turning this setting "on", GDB prints the index of each element
5063 when displaying arrays. The default is "off" to preserve the previous
5066 * VAX floating point support
5068 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5070 * User-defined command support
5072 In addition to using $arg0..$arg9 for argument passing, it is now possible
5073 to use $argc to determine now many arguments have been passed. See the
5074 section on user-defined commands in the user manual for more information.
5076 *** Changes in GDB 6.3:
5078 * New command line option
5080 GDB now accepts -l followed by a number to set the timeout for remote
5083 * GDB works with GCC -feliminate-dwarf2-dups
5085 GDB now supports a more compact representation of DWARF-2 debug
5086 information using DW_FORM_ref_addr references. These are produced
5087 by GCC with the option -feliminate-dwarf2-dups and also by some
5088 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5089 to use -feliminate-dwarf2-dups.
5091 * Internationalization
5093 When supported by the host system, GDB will be built with
5094 internationalization (libintl). The task of marking up the sources is
5095 continued, we're looking forward to our first translation.
5099 Initial support for debugging programs compiled with the GNAT
5100 implementation of the Ada programming language has been integrated
5101 into GDB. In this release, support is limited to expression evaluation.
5103 * New native configurations
5105 GNU/Linux/m32r m32r-*-linux-gnu
5109 GDB's remote protocol now includes support for the 'p' packet. This
5110 packet is used to fetch individual registers from a remote inferior.
5112 * END-OF-LIFE registers[] compatibility module
5114 GDB's internal register infrastructure has been completely rewritten.
5115 The new infrastructure making possible the implementation of key new
5116 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5119 GDB 6.3 will be the last release to include the the registers[]
5120 compatibility module that allowed out-of-date configurations to
5121 continue to work. This change directly impacts the following
5131 powerpc bdm protocol
5133 Unless there is activity to revive these configurations, they will be
5134 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5136 * OBSOLETE configurations and files
5138 Configurations that have been declared obsolete in this release have
5139 been commented out. Unless there is activity to revive these
5140 configurations, the next release of GDB will have their sources
5141 permanently REMOVED.
5150 *** Changes in GDB 6.2.1:
5152 * MIPS `break main; run' gave an heuristic-fence-post warning
5154 When attempting to run even a simple program, a warning about
5155 heuristic-fence-post being hit would be reported. This problem has
5158 * MIPS IRIX 'long double' crashed GDB
5160 When examining a long double variable, GDB would get a segmentation
5161 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5162 IRIX long double values).
5166 A bug in the VAX stack code was causing problems with the "next"
5167 command. This problem has been fixed.
5169 *** Changes in GDB 6.2:
5171 * Fix for ``many threads''
5173 On GNU/Linux systems that use the NPTL threads library, a program
5174 rapidly creating and deleting threads would confuse GDB leading to the
5177 ptrace: No such process.
5178 thread_db_get_info: cannot get thread info: generic error
5180 This problem has been fixed.
5182 * "-async" and "-noasync" options removed.
5184 Support for the broken "-noasync" option has been removed (it caused
5187 * New ``start'' command.
5189 This command runs the program until the begining of the main procedure.
5191 * New BSD Kernel Data Access Library (libkvm) interface
5193 Using ``target kvm'' it is now possible to debug kernel core dumps and
5194 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5195 platforms. Currently supported (native-only) configurations are:
5197 FreeBSD/amd64 x86_64-*-freebsd*
5198 FreeBSD/i386 i?86-*-freebsd*
5199 NetBSD/i386 i?86-*-netbsd*
5200 NetBSD/m68k m68*-*-netbsd*
5201 NetBSD/sparc sparc-*-netbsd*
5202 OpenBSD/amd64 x86_64-*-openbsd*
5203 OpenBSD/i386 i?86-*-openbsd*
5204 OpenBSD/m68k m68*-openbsd*
5205 OpenBSD/sparc sparc-*-openbsd*
5207 * Signal trampoline code overhauled
5209 Many generic problems with GDB's signal handling code have been fixed.
5210 These include: backtraces through non-contiguous stacks; recognition
5211 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5212 call; backtrace through a signal trampoline; step into and out of
5213 signal handlers; and single-stepping in the signal trampoline.
5215 Please note that kernel bugs are a limiting factor here. These
5216 features have been shown to work on an s390 GNU/Linux system that
5217 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5219 * Cygwin support for DWARF 2 added.
5221 * New native configurations
5223 GNU/Linux/hppa hppa*-*-linux*
5224 OpenBSD/hppa hppa*-*-openbsd*
5225 OpenBSD/m68k m68*-*-openbsd*
5226 OpenBSD/m88k m88*-*-openbsd*
5227 OpenBSD/powerpc powerpc-*-openbsd*
5228 NetBSD/vax vax-*-netbsd*
5229 OpenBSD/vax vax-*-openbsd*
5231 * END-OF-LIFE frame compatibility module
5233 GDB's internal frame infrastructure has been completely rewritten.
5234 The new infrastructure making it possible to support key new features
5235 including DWARF 2 Call Frame Information. To aid in the task of
5236 migrating old configurations to this new infrastructure, a
5237 compatibility module, that allowed old configurations to continue to
5238 work, was also included.
5240 GDB 6.2 will be the last release to include this frame compatibility
5241 module. This change directly impacts the following configurations:
5251 Unless there is activity to revive these configurations, they will be
5252 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5254 * REMOVED configurations and files
5256 Sun 3, running SunOS 3 m68*-*-sunos3*
5257 Sun 3, running SunOS 4 m68*-*-sunos4*
5258 Sun 2, running SunOS 3 m68000-*-sunos3*
5259 Sun 2, running SunOS 4 m68000-*-sunos4*
5260 Motorola 680x0 running LynxOS m68*-*-lynxos*
5261 AT&T 3b1/Unix pc m68*-att-*
5262 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5263 decstation mips-dec-* mips-little-*
5264 riscos mips-*-riscos* mips-*-sysv*
5265 sonymips mips-sony-*
5266 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5268 *** Changes in GDB 6.1.1:
5270 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5272 The TUI (Text-mode User Interface) is now built as part of a default
5273 GDB configuration. It is enabled by either selecting the TUI with the
5274 command line option "-i=tui" or by running the separate "gdbtui"
5275 program. For more information on the TUI, see the manual "Debugging
5278 * Pending breakpoint support (also included in GDB 6.1)
5280 Support has been added to allow you to specify breakpoints in shared
5281 libraries that have not yet been loaded. If a breakpoint location
5282 cannot be found, and the "breakpoint pending" option is set to auto,
5283 GDB queries you if you wish to make the breakpoint pending on a future
5284 shared-library load. If and when GDB resolves the breakpoint symbol,
5285 the pending breakpoint is removed as one or more regular breakpoints
5288 Pending breakpoints are very useful for GCJ Java debugging.
5290 * Fixed ISO-C build problems
5292 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5293 non ISO-C code that stopped them being built using a more strict ISO-C
5294 compiler (e.g., IBM's C compiler).
5296 * Fixed build problem on IRIX 5
5298 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5299 wasn't able to compile compile on an IRIX 5 system.
5301 * Added execute permission to gdb/gdbserver/configure
5303 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5304 permission. This bug would cause configure to fail on a number of
5305 systems (Solaris, IRIX). Ref: server/519.
5307 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5309 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5310 has been updated to use constant array sizes.
5312 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5314 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5315 its generated DWARF Call Frame Info. This encoding was causing GDB to
5316 panic, that panic has been fixed. Ref: gdb/1628.
5318 * Fixed a problem when examining parameters in shared library code.
5320 When examining parameters in optimized shared library code generated
5321 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5322 not available''. GDB now correctly displays the variable's value.
5324 *** Changes in GDB 6.1:
5326 * Removed --with-mmalloc
5328 Support for the mmalloc memory manager has been removed, as it
5329 conflicted with the internal gdb byte cache.
5331 * Changes in AMD64 configurations
5333 The AMD64 target now includes the %cs and %ss registers. As a result
5334 the AMD64 remote protocol has changed; this affects the floating-point
5335 and SSE registers. If you rely on those registers for your debugging,
5336 you should upgrade gdbserver on the remote side.
5338 * Revised SPARC target
5340 The SPARC target has been completely revised, incorporating the
5341 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5342 support for LynxOS and SunOS 4 has been dropped. Calling functions
5343 from within GDB on operating systems with a non-executable stack
5344 (Solaris, OpenBSD) now works.
5348 GDB has a new C++ demangler which does a better job on the mangled
5349 names generated by current versions of g++. It also runs faster, so
5350 with this and other changes gdb should now start faster on large C++
5353 * DWARF 2 Location Expressions
5355 GDB support for location expressions has been extended to support function
5356 arguments and frame bases. Older versions of GDB could crash when they
5359 * C++ nested types and namespaces
5361 GDB's support for nested types and namespaces in C++ has been
5362 improved, especially if you use the DWARF 2 debugging format. (This
5363 is the default for recent versions of GCC on most platforms.)
5364 Specifically, if you have a class "Inner" defined within a class or
5365 namespace "Outer", then GDB realizes that the class's name is
5366 "Outer::Inner", not simply "Inner". This should greatly reduce the
5367 frequency of complaints about not finding RTTI symbols. In addition,
5368 if you are stopped at inside of a function defined within a namespace,
5369 GDB modifies its name lookup accordingly.
5371 * New native configurations
5373 NetBSD/amd64 x86_64-*-netbsd*
5374 OpenBSD/amd64 x86_64-*-openbsd*
5375 OpenBSD/alpha alpha*-*-openbsd*
5376 OpenBSD/sparc sparc-*-openbsd*
5377 OpenBSD/sparc64 sparc64-*-openbsd*
5379 * New debugging protocols
5381 M32R with SDI protocol m32r-*-elf*
5383 * "set prompt-escape-char" command deleted.
5385 The command "set prompt-escape-char" has been deleted. This command,
5386 and its very obscure effet on GDB's prompt, was never documented,
5387 tested, nor mentioned in the NEWS file.
5389 * OBSOLETE configurations and files
5391 Configurations that have been declared obsolete in this release have
5392 been commented out. Unless there is activity to revive these
5393 configurations, the next release of GDB will have their sources
5394 permanently REMOVED.
5396 Sun 3, running SunOS 3 m68*-*-sunos3*
5397 Sun 3, running SunOS 4 m68*-*-sunos4*
5398 Sun 2, running SunOS 3 m68000-*-sunos3*
5399 Sun 2, running SunOS 4 m68000-*-sunos4*
5400 Motorola 680x0 running LynxOS m68*-*-lynxos*
5401 AT&T 3b1/Unix pc m68*-att-*
5402 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5403 decstation mips-dec-* mips-little-*
5404 riscos mips-*-riscos* mips-*-sysv*
5405 sonymips mips-sony-*
5406 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5408 * REMOVED configurations and files
5410 SGI Irix-4.x mips-sgi-irix4 or iris4
5411 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5412 Z8000 simulator z8k-zilog-none or z8ksim
5413 Matsushita MN10200 w/simulator mn10200-*-*
5414 H8/500 simulator h8500-hitachi-hms or h8500hms
5415 HP/PA running BSD hppa*-*-bsd*
5416 HP/PA running OSF/1 hppa*-*-osf*
5417 HP/PA Pro target hppa*-*-pro*
5418 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5419 386BSD i[3456]86-*-bsd*
5420 Sequent family i[3456]86-sequent-sysv4*
5421 i[3456]86-sequent-sysv*
5422 i[3456]86-sequent-bsd*
5423 SPARC running LynxOS sparc-*-lynxos*
5424 SPARC running SunOS 4 sparc-*-sunos4*
5425 Tsqware Sparclet sparclet-*-*
5426 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5428 *** Changes in GDB 6.0:
5432 Support for debugging the Objective-C programming language has been
5433 integrated into GDB.
5435 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5437 DWARF 2's Call Frame Information makes available compiler generated
5438 information that more exactly describes the program's run-time stack.
5439 By using this information, GDB is able to provide more robust stack
5442 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5443 have been updated to use a new backtrace mechanism which includes
5444 DWARF 2 CFI support.
5448 GDB's remote protocol has been extended to include support for hosted
5449 file I/O (where the remote target uses GDB's file system). See GDB's
5450 remote protocol documentation for details.
5452 * All targets using the new architecture framework.
5454 All of GDB's targets have been updated to use the new internal
5455 architecture framework. The way is now open for future GDB releases
5456 to include cross-architecture native debugging support (i386 on amd64,
5459 * GNU/Linux's Thread Local Storage (TLS)
5461 GDB now includes support for for the GNU/Linux implementation of
5462 per-thread variables.
5464 * GNU/Linux's Native POSIX Thread Library (NPTL)
5466 GDB's thread code has been updated to work with either the new
5467 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5469 * Separate debug info.
5471 GDB, in conjunction with BINUTILS, now supports a mechanism for
5472 automatically loading debug information from a separate file. Instead
5473 of shipping full debug and non-debug versions of system libraries,
5474 system integrators can now instead ship just the stripped libraries
5475 and optional debug files.
5477 * DWARF 2 Location Expressions
5479 DWARF 2 Location Expressions allow the compiler to more completely
5480 describe the location of variables (even in optimized code) to the
5483 GDB now includes preliminary support for location expressions (support
5484 for DW_OP_piece is still missing).
5488 A number of long standing bugs that caused GDB to die while starting a
5489 Java application have been fixed. GDB's Java support is now
5490 considered "useable".
5492 * GNU/Linux support for fork, vfork, and exec.
5494 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5495 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5498 * GDB supports logging output to a file
5500 There are two new commands, "set logging" and "show logging", which can be
5501 used to capture GDB's output to a file.
5503 * The meaning of "detach" has changed for gdbserver
5505 The "detach" command will now resume the application, as documented. To
5506 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5509 * d10v, m68hc11 `regs' command deprecated
5511 The `info registers' command has been updated so that it displays the
5512 registers using a format identical to the old `regs' command.
5516 A new command, "maint set profile on/off", has been added. This command can
5517 be used to enable or disable profiling while running GDB, to profile a
5518 session or a set of commands. In addition there is a new configure switch,
5519 "--enable-profiling", which will cause GDB to be compiled with profiling
5520 data, for more informative profiling results.
5522 * Default MI syntax changed to "mi2".
5524 The default MI (machine interface) syntax, enabled by the command line
5525 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5526 "mi1", can be enabled by specifying the option "-i=mi1".
5528 Support for the original "mi0" syntax (included in GDB 5.0) has been
5531 Fix for gdb/192: removed extraneous space when displaying frame level.
5532 Fix for gdb/672: update changelist is now output in mi list format.
5533 Fix for gdb/702: a -var-assign that updates the value now shows up
5534 in a subsequent -var-update.
5536 * New native configurations.
5538 FreeBSD/amd64 x86_64-*-freebsd*
5540 * Multi-arched targets.
5542 HP/PA HPUX11 hppa*-*-hpux*
5543 Renesas M32R/D w/simulator m32r-*-elf*
5545 * OBSOLETE configurations and files
5547 Configurations that have been declared obsolete in this release have
5548 been commented out. Unless there is activity to revive these
5549 configurations, the next release of GDB will have their sources
5550 permanently REMOVED.
5552 Z8000 simulator z8k-zilog-none or z8ksim
5553 Matsushita MN10200 w/simulator mn10200-*-*
5554 H8/500 simulator h8500-hitachi-hms or h8500hms
5555 HP/PA running BSD hppa*-*-bsd*
5556 HP/PA running OSF/1 hppa*-*-osf*
5557 HP/PA Pro target hppa*-*-pro*
5558 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5559 Sequent family i[3456]86-sequent-sysv4*
5560 i[3456]86-sequent-sysv*
5561 i[3456]86-sequent-bsd*
5562 Tsqware Sparclet sparclet-*-*
5563 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5565 * REMOVED configurations and files
5568 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5569 IBM AIX PS/2 i[3456]86-*-aix
5570 i386 running Mach 3.0 i[3456]86-*-mach3*
5571 i386 running Mach i[3456]86-*-mach*
5572 i386 running OSF/1 i[3456]86-*osf1mk*
5573 HP/Apollo 68k Family m68*-apollo*-sysv*,
5575 m68*-hp-bsd*, m68*-hp-hpux*
5576 Argonaut Risc Chip (ARC) arc-*-*
5577 Mitsubishi D30V d30v-*-*
5578 Fujitsu FR30 fr30-*-elf*
5579 OS/9000 i[34]86-*-os9k
5580 I960 with MON960 i960-*-coff
5582 * MIPS $fp behavior changed
5584 The convenience variable $fp, for the MIPS, now consistently returns
5585 the address of the current frame's base. Previously, depending on the
5586 context, $fp could refer to either $sp or the current frame's base
5587 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5588 The GNU Source-Level Debugger''.
5590 *** Changes in GDB 5.3:
5592 * GNU/Linux shared library multi-threaded performance improved.
5594 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5595 `/proc', in preference to `ptrace' for memory reads. This may result
5596 in an improvement in the start-up time of multi-threaded, shared
5597 library applications when run under GDB. One GDB user writes: ``loads
5598 shared libs like mad''.
5600 * ``gdbserver'' now supports multi-threaded applications on some targets
5602 Support for debugging multi-threaded applications which use
5603 the GNU/Linux LinuxThreads package has been added for
5604 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5605 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5607 * GDB now supports C/C++ preprocessor macros.
5609 GDB now expands preprocessor macro invocations in C/C++ expressions,
5610 and provides various commands for showing macro definitions and how
5613 The new command `macro expand EXPRESSION' expands any macro
5614 invocations in expression, and shows the result.
5616 The new command `show macro MACRO-NAME' shows the definition of the
5617 macro named MACRO-NAME, and where it was defined.
5619 Most compilers don't include information about macros in the debugging
5620 information by default. In GCC 3.1, for example, you need to compile
5621 your program with the options `-gdwarf-2 -g3'. If the macro
5622 information is present in the executable, GDB will read it.
5624 * Multi-arched targets.
5626 DEC Alpha (partial) alpha*-*-*
5627 DEC VAX (partial) vax-*-*
5629 National Semiconductor NS32000 (partial) ns32k-*-*
5630 Motorola 68000 (partial) m68k-*-*
5631 Motorola MCORE mcore-*-*
5635 Fujitsu FRV architecture added by Red Hat frv*-*-*
5638 * New native configurations
5640 Alpha NetBSD alpha*-*-netbsd*
5641 SH NetBSD sh*-*-netbsdelf*
5642 MIPS NetBSD mips*-*-netbsd*
5643 UltraSPARC NetBSD sparc64-*-netbsd*
5645 * OBSOLETE configurations and files
5647 Configurations that have been declared obsolete in this release have
5648 been commented out. Unless there is activity to revive these
5649 configurations, the next release of GDB will have their sources
5650 permanently REMOVED.
5652 Mitsubishi D30V d30v-*-*
5653 OS/9000 i[34]86-*-os9k
5654 IBM AIX PS/2 i[3456]86-*-aix
5655 Fujitsu FR30 fr30-*-elf*
5656 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5657 Argonaut Risc Chip (ARC) arc-*-*
5658 i386 running Mach 3.0 i[3456]86-*-mach3*
5659 i386 running Mach i[3456]86-*-mach*
5660 i386 running OSF/1 i[3456]86-*osf1mk*
5661 HP/Apollo 68k Family m68*-apollo*-sysv*,
5663 m68*-hp-bsd*, m68*-hp-hpux*
5664 I960 with MON960 i960-*-coff
5666 * OBSOLETE languages
5668 CHILL, a Pascal like language used by telecommunications companies.
5670 * REMOVED configurations and files
5672 AMD 29k family via UDI a29k-amd-udi, udi29k
5673 A29K VxWorks a29k-*-vxworks
5674 AMD 29000 embedded, using EBMON a29k-none-none
5675 AMD 29000 embedded with COFF a29k-none-coff
5676 AMD 29000 embedded with a.out a29k-none-aout
5678 testsuite/gdb.hp/gdb.threads-hp/ directory
5680 * New command "set max-user-call-depth <nnn>"
5682 This command allows the user to limit the call depth of user-defined
5683 commands. The default is 1024.
5685 * Changes in FreeBSD/i386 native debugging.
5687 Support for the "generate-core-file" has been added.
5689 * New commands "dump", "append", and "restore".
5691 These commands allow data to be copied from target memory
5692 to a bfd-format or binary file (dump and append), and back
5693 from a file into memory (restore).
5695 * Improved "next/step" support on multi-processor Alpha Tru64.
5697 The previous single-step mechanism could cause unpredictable problems,
5698 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5699 of a software single-step mechanism prevents this.
5701 *** Changes in GDB 5.2.1:
5709 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5710 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5711 Fix, by Joel Brobecker imported from mainline.
5713 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5714 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5715 Fix, by Fred Fish, imported from mainline.
5717 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5718 Surprisingly enough, it works now.
5719 By Michal Ludvig, imported from mainline.
5721 i386 hardware watchpoint support:
5722 avoid misses on second run for some targets.
5723 By Pierre Muller, imported from mainline.
5725 *** Changes in GDB 5.2:
5727 * New command "set trust-readonly-sections on[off]".
5729 This command is a hint that tells gdb that read-only sections
5730 really are read-only (ie. that their contents will not change).
5731 In this mode, gdb will go to the object file rather than the
5732 target to read memory from read-only sections (such as ".text").
5733 This can be a significant performance improvement on some
5734 (notably embedded) targets.
5736 * New command "generate-core-file" (or "gcore").
5738 This new gdb command allows the user to drop a core file of the child
5739 process state at any time. So far it's been implemented only for
5740 GNU/Linux and Solaris, but should be relatively easily ported to other
5741 hosts. Argument is core file name (defaults to core.<pid>).
5743 * New command line option
5745 GDB now accepts --pid or -p followed by a process id.
5747 * Change in command line behavior -- corefiles vs. process ids.
5749 There is a subtle behavior in the way in which GDB handles
5750 command line arguments. The first non-flag argument is always
5751 a program to debug, but the second non-flag argument may either
5752 be a corefile or a process id. Previously, GDB would attempt to
5753 open the second argument as a corefile, and if that failed, would
5754 issue a superfluous error message and then attempt to attach it as
5755 a process. Now, if the second argument begins with a non-digit,
5756 it will be treated as a corefile. If it begins with a digit,
5757 GDB will attempt to attach it as a process, and if no such process
5758 is found, will then attempt to open it as a corefile.
5760 * Changes in ARM configurations.
5762 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5763 configuration is fully multi-arch.
5765 * New native configurations
5767 ARM NetBSD arm*-*-netbsd*
5768 x86 OpenBSD i[3456]86-*-openbsd*
5769 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5770 Sparc64 running FreeBSD sparc64-*-freebsd*
5774 Sanyo XStormy16 xstormy16-elf
5776 * OBSOLETE configurations and files
5778 Configurations that have been declared obsolete in this release have
5779 been commented out. Unless there is activity to revive these
5780 configurations, the next release of GDB will have their sources
5781 permanently REMOVED.
5783 AMD 29k family via UDI a29k-amd-udi, udi29k
5784 A29K VxWorks a29k-*-vxworks
5785 AMD 29000 embedded, using EBMON a29k-none-none
5786 AMD 29000 embedded with COFF a29k-none-coff
5787 AMD 29000 embedded with a.out a29k-none-aout
5789 testsuite/gdb.hp/gdb.threads-hp/ directory
5791 * REMOVED configurations and files
5793 TI TMS320C80 tic80-*-*
5795 PowerPC Solaris powerpcle-*-solaris*
5796 PowerPC Windows NT powerpcle-*-cygwin32
5797 PowerPC Netware powerpc-*-netware*
5798 Harris/CXUX m88k m88*-harris-cxux*
5799 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5800 ns32k-utek-sysv* ns32k-utek-*
5801 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5802 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5803 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5804 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5805 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5807 * Changes to command line processing
5809 The new `--args' feature can be used to specify command-line arguments
5810 for the inferior from gdb's command line.
5812 * Changes to key bindings
5814 There is a new `operate-and-get-next' function bound to `C-o'.
5816 *** Changes in GDB 5.1.1
5818 Fix compile problem on DJGPP.
5820 Fix a problem with floating-point registers on the i386 being
5823 Fix to stop GDB crashing on .debug_str debug info.
5825 Numerous documentation fixes.
5827 Numerous testsuite fixes.
5829 *** Changes in GDB 5.1:
5831 * New native configurations
5833 Alpha FreeBSD alpha*-*-freebsd*
5834 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5835 MIPS GNU/Linux mips*-*-linux*
5836 MIPS SGI Irix 6.x mips*-sgi-irix6*
5837 ia64 AIX ia64-*-aix*
5838 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5842 Motorola 68HC11 and 68HC12 m68hc11-elf
5844 UltraSparc running GNU/Linux sparc64-*-linux*
5846 * OBSOLETE configurations and files
5848 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5849 Harris/CXUX m88k m88*-harris-cxux*
5850 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5851 ns32k-utek-sysv* ns32k-utek-*
5852 TI TMS320C80 tic80-*-*
5854 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5855 PowerPC Solaris powerpcle-*-solaris*
5856 PowerPC Windows NT powerpcle-*-cygwin32
5857 PowerPC Netware powerpc-*-netware*
5858 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5859 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5860 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5861 Apple Macintosh (MPW) host N/A
5863 stuff.c (Program to stuff files into a specially prepared space in kdb)
5864 kdb-start.c (Main loop for the standalone kernel debugger)
5866 Configurations that have been declared obsolete in this release have
5867 been commented out. Unless there is activity to revive these
5868 configurations, the next release of GDB will have their sources
5869 permanently REMOVED.
5871 * REMOVED configurations and files
5873 Altos 3068 m68*-altos-*
5874 Convex c1-*-*, c2-*-*
5876 ARM RISCix arm-*-* (as host)
5880 * GDB has been converted to ISO C.
5882 GDB's source code has been converted to ISO C. In particular, the
5883 sources are fully protoized, and rely on standard headers being
5888 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5890 * The MI enabled by default.
5892 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5893 revised and enabled by default. Packages which use GDB as a debugging
5894 engine behind a UI or another front end are encouraged to switch to
5895 using the GDB/MI interface, instead of the old annotations interface
5896 which is now deprecated.
5898 * Support for debugging Pascal programs.
5900 GDB now includes support for debugging Pascal programs. The following
5901 main features are supported:
5903 - Pascal-specific data types such as sets;
5905 - automatic recognition of Pascal sources based on file-name
5908 - Pascal-style display of data types, variables, and functions;
5910 - a Pascal expression parser.
5912 However, some important features are not yet supported.
5914 - Pascal string operations are not supported at all;
5916 - there are some problems with boolean types;
5918 - Pascal type hexadecimal constants are not supported
5919 because they conflict with the internal variables format;
5921 - support for Pascal objects and classes is not full yet;
5923 - unlike Pascal, GDB is case-sensitive for symbol names.
5925 * Changes in completion.
5927 Commands such as `shell', `run' and `set args', which pass arguments
5928 to inferior programs, now complete on file names, similar to what
5929 users expect at the shell prompt.
5931 Commands which accept locations, such as `disassemble', `print',
5932 `breakpoint', `until', etc. now complete on filenames as well as
5933 program symbols. Thus, if you type "break foob TAB", and the source
5934 files linked into the programs include `foobar.c', that file name will
5935 be one of the candidates for completion. However, file names are not
5936 considered for completion after you typed a colon that delimits a file
5937 name from a name of a function in that file, as in "break foo.c:bar".
5939 `set demangle-style' completes on available demangling styles.
5941 * New platform-independent commands:
5943 It is now possible to define a post-hook for a command as well as a
5944 hook that runs before the command. For more details, see the
5945 documentation of `hookpost' in the GDB manual.
5947 * Changes in GNU/Linux native debugging.
5949 Support for debugging multi-threaded programs has been completely
5950 revised for all platforms except m68k and sparc. You can now debug as
5951 many threads as your system allows you to have.
5953 Attach/detach is supported for multi-threaded programs.
5955 Support for SSE registers was added for x86. This doesn't work for
5956 multi-threaded programs though.
5958 * Changes in MIPS configurations.
5960 Multi-arch support is enabled for all MIPS configurations.
5962 GDB can now be built as native debugger on SGI Irix 6.x systems for
5963 debugging n32 executables. (Debugging 64-bit executables is not yet
5966 * Unified support for hardware watchpoints in all x86 configurations.
5968 Most (if not all) native x86 configurations support hardware-assisted
5969 breakpoints and watchpoints in a unified manner. This support
5970 implements debug register sharing between watchpoints, which allows to
5971 put a virtually infinite number of watchpoints on the same address,
5972 and also supports watching regions up to 16 bytes with several debug
5975 The new maintenance command `maintenance show-debug-regs' toggles
5976 debugging print-outs in functions that insert, remove, and test
5977 watchpoints and hardware breakpoints.
5979 * Changes in the DJGPP native configuration.
5981 New command ``info dos sysinfo'' displays assorted information about
5982 the CPU, OS, memory, and DPMI server.
5984 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5985 display information about segment descriptors stored in GDT, LDT, and
5988 New commands ``info dos pde'' and ``info dos pte'' display entries
5989 from Page Directory and Page Tables (for now works with CWSDPMI only).
5990 New command ``info dos address-pte'' displays the Page Table entry for
5991 a given linear address.
5993 GDB can now pass command lines longer than 126 characters to the
5994 program being debugged (requires an update to the libdbg.a library
5995 which is part of the DJGPP development kit).
5997 DWARF2 debug info is now supported.
5999 It is now possible to `step' and `next' through calls to `longjmp'.
6001 * Changes in documentation.
6003 All GDB documentation was converted to GFDL, the GNU Free
6004 Documentation License.
6006 Tracepoints-related commands are now fully documented in the GDB
6009 TUI, the Text-mode User Interface, is now documented in the manual.
6011 Tracepoints-related commands are now fully documented in the GDB
6014 The "GDB Internals" manual now has an index. It also includes
6015 documentation of `ui_out' functions, GDB coding standards, x86
6016 hardware watchpoints, and memory region attributes.
6018 * GDB's version number moved to ``version.in''
6020 The Makefile variable VERSION has been replaced by the file
6021 ``version.in''. People creating GDB distributions should update the
6022 contents of this file.
6026 GUD support is now a standard part of the EMACS distribution.
6028 *** Changes in GDB 5.0:
6030 * Improved support for debugging FP programs on x86 targets
6032 Unified and much-improved support for debugging floating-point
6033 programs on all x86 targets. In particular, ``info float'' now
6034 displays the FP registers in the same format on all x86 targets, with
6035 greater level of detail.
6037 * Improvements and bugfixes in hardware-assisted watchpoints
6039 It is now possible to watch array elements, struct members, and
6040 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6041 on x86 targets no longer erroneously trigger when the address is
6044 * Improvements in the native DJGPP version of GDB
6046 The distribution now includes all the scripts and auxiliary files
6047 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6048 machines ``out of the box''.
6050 The DJGPP version can now debug programs that use signals. It is
6051 possible to catch signals that happened in the debuggee, deliver
6052 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6053 would kill the program being debugged.) Programs that hook hardware
6054 interrupts (keyboard, timer, etc.) can also be debugged.
6056 It is now possible to debug DJGPP programs that redirect their
6057 standard handles or switch them to raw (as opposed to cooked) mode, or
6058 even close them. The command ``run < foo > bar'' works as expected,
6059 and ``info terminal'' reports useful information about the debuggee's
6060 terminal, including raw/cooked mode, redirection, etc.
6062 The DJGPP version now uses termios functions for console I/O, which
6063 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6066 DOS-style file names with drive letters are now fully supported by
6069 It is now possible to debug DJGPP programs that switch their working
6070 directory. It is also possible to rerun the debuggee any number of
6071 times without restarting GDB; thus, you can use the same setup,
6072 breakpoints, etc. for many debugging sessions.
6074 * New native configurations
6076 ARM GNU/Linux arm*-*-linux*
6077 PowerPC GNU/Linux powerpc-*-linux*
6081 Motorola MCore mcore-*-*
6082 x86 VxWorks i[3456]86-*-vxworks*
6083 PowerPC VxWorks powerpc-*-vxworks*
6084 TI TMS320C80 tic80-*-*
6086 * OBSOLETE configurations
6088 Altos 3068 m68*-altos-*
6089 Convex c1-*-*, c2-*-*
6091 ARM RISCix arm-*-* (as host)
6094 Configurations that have been declared obsolete will be commented out,
6095 but the code will be left in place. If there is no activity to revive
6096 these configurations before the next release of GDB, the sources will
6097 be permanently REMOVED.
6099 * Gould support removed
6101 Support for the Gould PowerNode and NP1 has been removed.
6103 * New features for SVR4
6105 On SVR4 native platforms (such as Solaris), if you attach to a process
6106 without first loading a symbol file, GDB will now attempt to locate and
6107 load symbols from the running process's executable file.
6109 * Many C++ enhancements
6111 C++ support has been greatly improved. Overload resolution now works properly
6112 in almost all cases. RTTI support is on the way.
6114 * Remote targets can connect to a sub-program
6116 A popen(3) style serial-device has been added. This device starts a
6117 sub-process (such as a stand-alone simulator) and then communicates
6118 with that. The sub-program to run is specified using the syntax
6119 ``|<program> <args>'' vis:
6121 (gdb) set remotedebug 1
6122 (gdb) target extended-remote |mn10300-elf-sim program-args
6124 * MIPS 64 remote protocol
6126 A long standing bug in the mips64 remote protocol where by GDB
6127 expected certain 32 bit registers (ex SR) to be transfered as 32
6128 instead of 64 bits has been fixed.
6130 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6131 added to provide backward compatibility with older versions of GDB.
6133 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6135 The command ``set remotebinarydownload'' command has been replaced by
6136 ``set remote X-packet''. Other commands in ``set remote'' family
6137 include ``set remote P-packet''.
6139 * Breakpoint commands accept ranges.
6141 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6142 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6143 ``tracepoint passcount'' also accepts a range of tracepoints.
6145 * ``apropos'' command added.
6147 The ``apropos'' command searches through command names and
6148 documentation strings, printing out matches, making it much easier to
6149 try to find a command that does what you are looking for.
6153 A new machine oriented interface (MI) has been added to GDB. This
6154 interface is designed for debug environments running GDB as a separate
6155 process. This is part of the long term libGDB project. See the
6156 "GDB/MI" chapter of the GDB manual for further information. It can be
6157 enabled by configuring with:
6159 .../configure --enable-gdbmi
6161 *** Changes in GDB-4.18:
6163 * New native configurations
6165 HP-UX 10.20 hppa*-*-hpux10.20
6166 HP-UX 11.x hppa*-*-hpux11.0*
6167 M68K GNU/Linux m68*-*-linux*
6171 Fujitsu FR30 fr30-*-elf*
6172 Intel StrongARM strongarm-*-*
6173 Mitsubishi D30V d30v-*-*
6175 * OBSOLETE configurations
6177 Gould PowerNode, NP1 np1-*-*, pn-*-*
6179 Configurations that have been declared obsolete will be commented out,
6180 but the code will be left in place. If there is no activity to revive
6181 these configurations before the next release of GDB, the sources will
6182 be permanently REMOVED.
6186 As a compatibility experiment, GDB's source files buildsym.h and
6187 buildsym.c have been converted to pure standard C, no longer
6188 containing any K&R compatibility code. We believe that all systems in
6189 use today either come with a standard C compiler, or have a GCC port
6190 available. If this is not true, please report the affected
6191 configuration to bug-gdb@gnu.org immediately. See the README file for
6192 information about getting a standard C compiler if you don't have one
6197 GDB now uses readline 2.2.
6199 * set extension-language
6201 You can now control the mapping between filename extensions and source
6202 languages by using the `set extension-language' command. For instance,
6203 you can ask GDB to treat .c files as C++ by saying
6204 set extension-language .c c++
6205 The command `info extensions' lists all of the recognized extensions
6206 and their associated languages.
6208 * Setting processor type for PowerPC and RS/6000
6210 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6211 you can use the `set processor' command to specify what variant of the
6212 PowerPC family you are debugging. The command
6216 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6217 following PowerPC and RS6000 variants:
6219 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6220 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6222 403GC IBM PowerPC 403GC
6223 505 Motorola PowerPC 505
6224 860 Motorola PowerPC 860 or 850
6225 601 Motorola PowerPC 601
6226 602 Motorola PowerPC 602
6227 603 Motorola/IBM PowerPC 603 or 603e
6228 604 Motorola PowerPC 604 or 604e
6229 750 Motorola/IBM PowerPC 750 or 750
6231 At the moment, this command just tells GDB what to name the
6232 special-purpose processor registers. Since almost all the affected
6233 registers are inaccessible to user-level programs, this command is
6234 only useful for remote debugging in its present form.
6238 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6239 more extensive support for HP-UX. Added features include shared
6240 library support, kernel threads and hardware watchpoints for 11.00,
6241 support for HP's ANSI C and C++ compilers, and a compatibility mode
6242 for xdb and dbx commands.
6246 HP's donation includes the new concept of catchpoints, which is a
6247 generalization of the old catch command. On HP-UX, it is now possible
6248 to catch exec, fork, and vfork, as well as library loading.
6250 This means that the existing catch command has changed; its first
6251 argument now specifies the type of catch to be set up. See the
6252 output of "help catch" for a list of catchpoint types.
6254 * Debugging across forks
6256 On HP-UX, you can choose which process to debug when a fork() happens
6261 HP has donated a curses-based terminal user interface (TUI). To get
6262 it, build with --enable-tui. Although this can be enabled for any
6263 configuration, at present it only works for native HP debugging.
6265 * GDB remote protocol additions
6267 A new protocol packet 'X' that writes binary data is now available.
6268 Default behavior is to try 'X', then drop back to 'M' if the stub
6269 fails to respond. The settable variable `remotebinarydownload'
6270 allows explicit control over the use of 'X'.
6272 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6273 full 64-bit address. The command
6275 set remoteaddresssize 32
6277 can be used to revert to the old behaviour. For existing remote stubs
6278 the change should not be noticed, as the additional address information
6281 In order to assist in debugging stubs, you may use the maintenance
6282 command `packet' to send any text string to the stub. For instance,
6284 maint packet heythere
6286 sends the packet "$heythere#<checksum>". Note that it is very easy to
6287 disrupt a debugging session by sending the wrong packet at the wrong
6290 The compare-sections command allows you to compare section data on the
6291 target to what is in the executable file without uploading or
6292 downloading, by comparing CRC checksums.
6294 * Tracing can collect general expressions
6296 You may now collect general expressions at tracepoints. This requires
6297 further additions to the target-side stub; see tracepoint.c and
6298 doc/agentexpr.texi for further details.
6300 * mask-address variable for Mips
6302 For Mips targets, you may control the zeroing of the upper 32 bits of
6303 a 64-bit address by entering `set mask-address on'. This is mainly
6304 of interest to users of embedded R4xxx and R5xxx processors.
6306 * Higher serial baud rates
6308 GDB's serial code now allows you to specify baud rates 57600, 115200,
6309 230400, and 460800 baud. (Note that your host system may not be able
6310 to achieve all of these rates.)
6314 The i960 configuration now includes an initial implementation of a
6315 builtin simulator, contributed by Jim Wilson.
6318 *** Changes in GDB-4.17:
6320 * New native configurations
6322 Alpha GNU/Linux alpha*-*-linux*
6323 Unixware 2.x i[3456]86-unixware2*
6324 Irix 6.x mips*-sgi-irix6*
6325 PowerPC GNU/Linux powerpc-*-linux*
6326 PowerPC Solaris powerpcle-*-solaris*
6327 Sparc GNU/Linux sparc-*-linux*
6328 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6332 Argonaut Risc Chip (ARC) arc-*-*
6333 Hitachi H8/300S h8300*-*-*
6334 Matsushita MN10200 w/simulator mn10200-*-*
6335 Matsushita MN10300 w/simulator mn10300-*-*
6336 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6337 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6338 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6339 Mitsubishi D10V w/simulator d10v-*-*
6340 Mitsubishi M32R/D w/simulator m32r-*-elf*
6341 Tsqware Sparclet sparclet-*-*
6342 NEC V850 w/simulator v850-*-*
6344 * New debugging protocols
6346 ARM with RDI protocol arm*-*-*
6347 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6348 DDB and LSI variants of PMON protocol mips*-*-*
6349 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6350 PowerPC with SDS protocol powerpc{,le}-*-eabi
6351 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6355 All configurations can now understand and use the DWARF 2 debugging
6356 format. The choice is automatic, if the symbol file contains DWARF 2
6361 GDB now includes basic Java language support. This support is
6362 only useful with Java compilers that produce native machine code.
6364 * solib-absolute-prefix and solib-search-path
6366 For SunOS and SVR4 shared libraries, you may now set the prefix for
6367 loading absolute shared library symbol files, and the search path for
6368 locating non-absolute shared library symbol files.
6370 * Live range splitting
6372 GDB can now effectively debug code for which GCC has performed live
6373 range splitting as part of its optimization. See gdb/doc/LRS for
6374 more details on the expected format of the stabs information.
6378 GDB's support for the GNU Hurd, including thread debugging, has been
6379 updated to work with current versions of the Hurd.
6383 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6384 instruction set. ARM GDB automatically detects when Thumb
6385 instructions are in use, and adjusts disassembly and backtracing
6390 GDB's MIPS target configurations now handle the MIP16 16-bit
6395 GDB now includes support for overlays; if an executable has been
6396 linked such that multiple sections are based at the same address, GDB
6397 will decide which section to use for symbolic info. You can choose to
6398 control the decision manually, using overlay commands, or implement
6399 additional target-side support and use "overlay load-target" to bring
6400 in the overlay mapping. Do "help overlay" for more detail.
6404 The command "info symbol <address>" displays information about
6405 the symbol at the specified address.
6409 The standard remote protocol now includes an extension that allows
6410 asynchronous collection and display of trace data. This requires
6411 extensive support in the target-side debugging stub. Tracing mode
6412 includes a new interaction mode in GDB and new commands: see the
6413 file tracepoint.c for more details.
6417 Configurations for embedded MIPS now include a simulator contributed
6418 by Cygnus Solutions. The simulator supports the instruction sets
6419 of most MIPS variants.
6423 Sparc configurations may now include the ERC32 simulator contributed
6424 by the European Space Agency. The simulator is not built into
6425 Sparc targets by default; configure with --enable-sim to include it.
6429 For target configurations that may include multiple variants of a
6430 basic architecture (such as MIPS and SH), you may now set the
6431 architecture explicitly. "set arch" sets, "info arch" lists
6432 the possible architectures.
6434 *** Changes in GDB-4.16:
6436 * New native configurations
6438 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6439 M68K NetBSD m68k-*-netbsd*
6440 PowerPC AIX 4.x powerpc-*-aix*
6441 PowerPC MacOS powerpc-*-macos*
6442 PowerPC Windows NT powerpcle-*-cygwin32
6443 RS/6000 AIX 4.x rs6000-*-aix4*
6447 ARM with RDP protocol arm-*-*
6448 I960 with MON960 i960-*-coff
6449 MIPS VxWorks mips*-*-vxworks*
6450 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6451 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6453 Matra Sparclet sparclet-*-*
6457 The powerpc-eabi configuration now includes the PSIM simulator,
6458 contributed by Andrew Cagney, with assistance from Mike Meissner.
6459 PSIM is a very elaborate model of the PowerPC, including not only
6460 basic instruction set execution, but also details of execution unit
6461 performance and I/O hardware. See sim/ppc/README for more details.
6465 GDB now works with Solaris 2.5.
6467 * Windows 95/NT native
6469 GDB will now work as a native debugger on Windows 95 and Windows NT.
6470 To build it from source, you must use the "gnu-win32" environment,
6471 which uses a DLL to emulate enough of Unix to run the GNU tools.
6472 Further information, binaries, and sources are available at
6473 ftp.cygnus.com, under pub/gnu-win32.
6475 * dont-repeat command
6477 If a user-defined command includes the command `dont-repeat', then the
6478 command will not be repeated if the user just types return. This is
6479 useful if the command is time-consuming to run, so that accidental
6480 extra keystrokes don't run the same command many times.
6482 * Send break instead of ^C
6484 The standard remote protocol now includes an option to send a break
6485 rather than a ^C to the target in order to interrupt it. By default,
6486 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6488 * Remote protocol timeout
6490 The standard remote protocol includes a new variable `remotetimeout'
6491 that allows you to set the number of seconds before GDB gives up trying
6492 to read from the target. The default value is 2.
6494 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6496 By default GDB will automatically keep track of objects as they are
6497 loaded and unloaded by the dynamic linker. By using the command `set
6498 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6499 when shared library events occur, thus allowing you to set breakpoints
6500 in shared libraries which are explicitly loaded by the inferior.
6502 Note this feature does not work on hpux8. On hpux9 you must link
6503 /usr/lib/end.o into your program. This feature should work
6504 automatically on hpux10.
6506 * Irix 5.x hardware watchpoint support
6508 Irix 5 configurations now support the use of hardware watchpoints.
6510 * Mips protocol "SYN garbage limit"
6512 When debugging a Mips target using the `target mips' protocol, you
6513 may set the number of characters that GDB will ignore by setting
6514 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6515 every character. The default value is 1050.
6517 * Recording and replaying remote debug sessions
6519 If you set `remotelogfile' to the name of a file, gdb will write to it
6520 a recording of a remote debug session. This recording may then be
6521 replayed back to gdb using "gdbreplay". See gdbserver/README for
6522 details. This is useful when you have a problem with GDB while doing
6523 remote debugging; you can make a recording of the session and send it
6524 to someone else, who can then recreate the problem.
6526 * Speedups for remote debugging
6528 GDB includes speedups for downloading and stepping MIPS systems using
6529 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6530 and more efficient S-record downloading.
6532 * Memory use reductions and statistics collection
6534 GDB now uses less memory and reports statistics about memory usage.
6535 Try the `maint print statistics' command, for example.
6537 *** Changes in GDB-4.15:
6539 * Psymtabs for XCOFF
6541 The symbol reader for AIX GDB now uses partial symbol tables. This
6542 can greatly improve startup time, especially for large executables.
6544 * Remote targets use caching
6546 Remote targets now use a data cache to speed up communication with the
6547 remote side. The data cache could lead to incorrect results because
6548 it doesn't know about volatile variables, thus making it impossible to
6549 debug targets which use memory mapped I/O devices. `set remotecache
6550 off' turns the the data cache off.
6552 * Remote targets may have threads
6554 The standard remote protocol now includes support for multiple threads
6555 in the target system, using new protocol commands 'H' and 'T'. See
6556 gdb/remote.c for details.
6560 If GDB is configured with `--enable-netrom', then it will include
6561 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6562 acts as though it is a bank of ROM on the target board, but you can
6563 write into it over the network. GDB's support consists only of
6564 support for fast loading into the emulated ROM; to debug, you must use
6565 another protocol, such as standard remote protocol. The usual
6566 sequence is something like
6568 target nrom <netrom-hostname>
6570 target remote <netrom-hostname>:1235
6574 GDB now includes support for the Apple Macintosh, as a host only. It
6575 may be run as either an MPW tool or as a standalone application, and
6576 it can debug through the serial port. All the usual GDB commands are
6577 available, but to the target command, you must supply "serial" as the
6578 device type instead of "/dev/ttyXX". See mpw-README in the main
6579 directory for more information on how to build. The MPW configuration
6580 scripts */mpw-config.in support only a few targets, and only the
6581 mips-idt-ecoff target has been tested.
6585 GDB configuration now uses autoconf. This is not user-visible,
6586 but does simplify configuration and building.
6590 GDB now supports hpux10.
6592 *** Changes in GDB-4.14:
6594 * New native configurations
6596 x86 FreeBSD i[345]86-*-freebsd
6597 x86 NetBSD i[345]86-*-netbsd
6598 NS32k NetBSD ns32k-*-netbsd
6599 Sparc NetBSD sparc-*-netbsd
6603 A29K VxWorks a29k-*-vxworks
6604 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6605 CPU32 EST-300 emulator m68*-*-est*
6606 PowerPC ELF powerpc-*-elf
6609 * Alpha OSF/1 support for procfs
6611 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6612 possible to attach to running processes. As the mounting of the /proc
6613 filesystem is optional on the Alpha, GDB automatically determines
6614 the availability of /proc during startup. This can lead to problems
6615 if /proc is unmounted after GDB has been started.
6617 * Arguments to user-defined commands
6619 User commands may accept up to 10 arguments separated by whitespace.
6620 Arguments are accessed within the user command via $arg0..$arg9. A
6623 print $arg0 + $arg1 + $arg2
6625 To execute the command use:
6628 Defines the command "adder" which prints the sum of its three arguments.
6629 Note the arguments are text substitutions, so they may reference variables,
6630 use complex expressions, or even perform inferior function calls.
6632 * New `if' and `while' commands
6634 This makes it possible to write more sophisticated user-defined
6635 commands. Both commands take a single argument, which is the
6636 expression to evaluate, and must be followed by the commands to
6637 execute, one per line, if the expression is nonzero, the list being
6638 terminated by the word `end'. The `if' command list may include an
6639 `else' word, which causes the following commands to be executed only
6640 if the expression is zero.
6642 * Fortran source language mode
6644 GDB now includes partial support for Fortran 77. It will recognize
6645 Fortran programs and can evaluate a subset of Fortran expressions, but
6646 variables and functions may not be handled correctly. GDB will work
6647 with G77, but does not yet know much about symbols emitted by other
6650 * Better HPUX support
6652 Most debugging facilities now work on dynamic executables for HPPAs
6653 running hpux9 or later. You can attach to running dynamically linked
6654 processes, but by default the dynamic libraries will be read-only, so
6655 for instance you won't be able to put breakpoints in them. To change
6656 that behavior do the following before running the program:
6662 This will cause the libraries to be mapped private and read-write.
6663 To revert to the normal behavior, do this:
6669 You cannot set breakpoints or examine data in the library until after
6670 the library is loaded if the function/data symbols do not have
6673 GDB can now also read debug symbols produced by the HP C compiler on
6674 HPPAs (sorry, no C++, Fortran or 68k support).
6676 * Target byte order now dynamically selectable
6678 You can choose which byte order to use with a target system, via the
6679 commands "set endian big" and "set endian little", and you can see the
6680 current setting by using "show endian". You can also give the command
6681 "set endian auto", in which case GDB will use the byte order
6682 associated with the executable. Currently, only embedded MIPS
6683 configurations support dynamic selection of target byte order.
6685 * New DOS host serial code
6687 This version uses DPMI interrupts to handle buffered I/O, so you
6688 no longer need to run asynctsr when debugging boards connected to
6691 *** Changes in GDB-4.13:
6693 * New "complete" command
6695 This lists all the possible completions for the rest of the line, if it
6696 were to be given as a command itself. This is intended for use by emacs.
6698 * Trailing space optional in prompt
6700 "set prompt" no longer adds a space for you after the prompt you set. This
6701 allows you to set a prompt which ends in a space or one that does not.
6703 * Breakpoint hit counts
6705 "info break" now displays a count of the number of times the breakpoint
6706 has been hit. This is especially useful in conjunction with "ignore"; you
6707 can ignore a large number of breakpoint hits, look at the breakpoint info
6708 to see how many times the breakpoint was hit, then run again, ignoring one
6709 less than that number, and this will get you quickly to the last hit of
6712 * Ability to stop printing at NULL character
6714 "set print null-stop" will cause GDB to stop printing the characters of
6715 an array when the first NULL is encountered. This is useful when large
6716 arrays actually contain only short strings.
6718 * Shared library breakpoints
6720 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6721 breakpoints in shared libraries before the executable is run.
6723 * Hardware watchpoints
6725 There is a new hardware breakpoint for the watch command for sparclite
6726 targets. See gdb/sparclite/hw_breakpoint.note.
6728 Hardware watchpoints are also now supported under GNU/Linux.
6732 Annotations have been added. These are for use with graphical interfaces,
6733 and are still experimental. Currently only gdba.el uses these.
6735 * Improved Irix 5 support
6737 GDB now works properly with Irix 5.2.
6739 * Improved HPPA support
6741 GDB now works properly with the latest GCC and GAS.
6743 * New native configurations
6745 Sequent PTX4 i[34]86-sequent-ptx4
6746 HPPA running OSF/1 hppa*-*-osf*
6747 Atari TT running SVR4 m68*-*-sysv4*
6748 RS/6000 LynxOS rs6000-*-lynxos*
6752 OS/9000 i[34]86-*-os9k
6753 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6756 * Hitachi SH7000 and E7000-PC ICE support
6758 There is now support for communicating with the Hitachi E7000-PC ICE.
6759 This is available automatically when GDB is configured for the SH.
6763 As usual, a variety of small fixes and improvements, both generic
6764 and configuration-specific. See the ChangeLog for more detail.
6766 *** Changes in GDB-4.12:
6768 * Irix 5 is now supported
6772 GDB-4.12 on the HPPA has a number of changes which make it unable
6773 to debug the output from the currently released versions of GCC and
6774 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6775 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6776 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6779 *** Changes in GDB-4.11:
6781 * User visible changes:
6785 The "set remotedebug" option is now consistent between the mips remote
6786 target, remote targets using the gdb-specific protocol, UDI (AMD's
6787 debug protocol for the 29k) and the 88k bug monitor. It is now an
6788 integer specifying a debug level (normally 0 or 1, but 2 means more
6789 debugging info for the mips target).
6791 * DEC Alpha native support
6793 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6794 debug info, but GDB works fairly well with the DEC compiler and should
6795 work with a future GCC release. See the README file for a few
6796 Alpha-specific notes.
6798 * Preliminary thread implementation
6800 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6802 * LynxOS native and target support for 386
6804 This release has been hosted on LynxOS 2.2, and also can be configured
6805 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6808 * Improvements in C++ mangling/demangling.
6810 This release has much better g++ debugging, specifically in name
6811 mangling/demangling, virtual function calls, print virtual table,
6812 call methods, ...etc.
6814 *** Changes in GDB-4.10:
6816 * User visible changes:
6818 Remote debugging using the GDB-specific (`target remote') protocol now
6819 supports the `load' command. This is only useful if you have some
6820 other way of getting the stub to the target system, and you can put it
6821 somewhere in memory where it won't get clobbered by the download.
6823 Filename completion now works.
6825 When run under emacs mode, the "info line" command now causes the
6826 arrow to point to the line specified. Also, "info line" prints
6827 addresses in symbolic form (as well as hex).
6829 All vxworks based targets now support a user settable option, called
6830 vxworks-timeout. This option represents the number of seconds gdb
6831 should wait for responses to rpc's. You might want to use this if
6832 your vxworks target is, perhaps, a slow software simulator or happens
6833 to be on the far side of a thin network line.
6837 This release contains support for using a DEC alpha as a GDB host for
6838 cross debugging. Native alpha debugging is not supported yet.
6841 *** Changes in GDB-4.9:
6845 This is the first GDB release which is accompanied by a matching testsuite.
6846 The testsuite requires installation of dejagnu, which should be available
6847 via ftp from most sites that carry GNU software.
6851 'Cfront' style demangling has had its name changed to 'ARM' style, to
6852 emphasize that it was written from the specifications in the C++ Annotated
6853 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6854 disclaimers, it still generated too much confusion with users attempting to
6855 use gdb with AT&T cfront.
6859 GDB now uses a standard remote interface to a simulator library.
6860 So far, the library contains simulators for the Zilog Z8001/2, the
6861 Hitachi H8/300, H8/500 and Super-H.
6863 * New targets supported
6865 H8/300 simulator h8300-hitachi-hms or h8300hms
6866 H8/500 simulator h8500-hitachi-hms or h8500hms
6867 SH simulator sh-hitachi-hms or sh
6868 Z8000 simulator z8k-zilog-none or z8ksim
6869 IDT MIPS board over serial line mips-idt-ecoff
6871 Cross-debugging to GO32 targets is supported. It requires a custom
6872 version of the i386-stub.c module which is integrated with the
6873 GO32 memory extender.
6875 * New remote protocols
6877 MIPS remote debugging protocol.
6879 * New source languages supported
6881 This version includes preliminary support for Chill, a Pascal like language
6882 used by telecommunications companies. Chill support is also being integrated
6883 into the GNU compiler, but we don't know when it will be publically available.
6886 *** Changes in GDB-4.8:
6888 * HP Precision Architecture supported
6890 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6891 version of this support was available as a set of patches from the
6892 University of Utah. GDB does not support debugging of programs
6893 compiled with the HP compiler, because HP will not document their file
6894 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6895 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6897 Many problems in the preliminary version have been fixed.
6899 * Faster and better demangling
6901 We have improved template demangling and fixed numerous bugs in the GNU style
6902 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6903 character types (wchar_t) are now supported. Demangling of each symbol is now
6904 only done once, and is cached when the symbol table for a file is read in.
6905 This results in a small increase in memory usage for C programs, a moderate
6906 increase in memory usage for C++ programs, and a fantastic speedup in
6909 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6910 from the specifications in the Annotated Reference Manual, which AT&T's
6911 compiler does not actually implement.
6913 * G++ multiple inheritance compiler problem
6915 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6916 inheritance lattices was reworked to properly discover ambiguities. We
6917 recently found an example which causes this new algorithm to fail in a
6918 very subtle way, producing bad debug information for those classes.
6919 The file 'gcc.patch' (in this directory) can be applied to gcc to
6920 circumvent the problem. A future GCC release will contain a complete
6923 The previous G++ debug info problem (mentioned below for the gdb-4.7
6924 release) is fixed in gcc version 2.3.2.
6926 * Improved configure script
6928 The `configure' script will now attempt to guess your system type if
6929 you don't supply a host system type. The old scheme of supplying a
6930 host system triplet is preferable over using this. All the magic is
6931 done in the new `config.guess' script. Examine it for details.
6933 We have also brought our configure script much more in line with the FSF's
6934 version. It now supports the --with-xxx options. In particular,
6935 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6936 The resulting GDB will not be able to read arbitrary object file formats --
6937 only the format ``expected'' to be used on the configured target system.
6938 We hope to make this the default in a future release.
6940 * Documentation improvements
6942 There's new internal documentation on how to modify GDB, and how to
6943 produce clean changes to the code. We implore people to read it
6944 before submitting changes.
6946 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6947 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6948 `info' files are also provided. To build `info' files from scratch,
6949 you will need the latest `makeinfo' release, which will be available in
6950 a future texinfo-X.Y release.
6952 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6953 We're not sure exactly which versions have this problem, but it has
6954 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6955 or better. If that isn't possible, there is a patch in
6956 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6957 around this problem.
6961 GDB now supports array constants that can be used in expressions typed in by
6962 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6963 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6966 The new directory `gdb/sparclite' contains a program that demonstrates
6967 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6969 * New native hosts supported
6971 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6972 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6974 * New targets supported
6976 AMD 29k family via UDI a29k-amd-udi or udi29k
6978 * New file formats supported
6980 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6981 HPUX core files, and SCO 3.2v2 core files.
6985 Attaching to processes now works again; thanks for the many bug reports.
6987 We have also stomped on a bunch of core dumps caused by
6988 printf_filtered("%s") problems.
6990 We eliminated a copyright problem on the rpc and ptrace header files
6991 for VxWorks, which was discovered at the last minute during the 4.7
6992 release. You should now be able to build a VxWorks GDB.
6994 You can now interrupt gdb while an attached process is running. This
6995 will cause the attached process to stop, and give control back to GDB.
6997 We fixed problems caused by using too many file descriptors
6998 for reading symbols from object files and libraries. This was
6999 especially a problem for programs that used many (~100) shared
7002 The `step' command now only enters a subroutine if there is line number
7003 information for the subroutine. Otherwise it acts like the `next'
7004 command. Previously, `step' would enter subroutines if there was
7005 any debugging information about the routine. This avoids problems
7006 when using `cc -g1' on MIPS machines.
7008 * Internal improvements
7010 GDB's internal interfaces have been improved to make it easier to support
7011 debugging of multiple languages in the future.
7013 GDB now uses a common structure for symbol information internally.
7014 Minimal symbols (derived from linkage symbols in object files), partial
7015 symbols (from a quick scan of debug information), and full symbols
7016 contain a common subset of information, making it easier to write
7017 shared code that handles any of them.
7019 * New command line options
7021 We now accept --silent as an alias for --quiet.
7025 The memory-mapped-malloc library is now licensed under the GNU Library
7026 General Public License.
7028 *** Changes in GDB-4.7:
7030 * Host/native/target split
7032 GDB has had some major internal surgery to untangle the support for
7033 hosts and remote targets. Now, when you configure GDB for a remote
7034 target, it will no longer load in all of the support for debugging
7035 local programs on the host. When fully completed and tested, this will
7036 ensure that arbitrary host/target combinations are possible.
7038 The primary conceptual shift is to separate the non-portable code in
7039 GDB into three categories. Host specific code is required any time GDB
7040 is compiled on that host, regardless of the target. Target specific
7041 code relates to the peculiarities of the target, but can be compiled on
7042 any host. Native specific code is everything else: it can only be
7043 built when the host and target are the same system. Child process
7044 handling and core file support are two common `native' examples.
7046 GDB's use of /proc for controlling Unix child processes is now cleaner.
7047 It has been split out into a single module under the `target_ops' vector,
7048 plus two native-dependent functions for each system that uses /proc.
7050 * New hosts supported
7052 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7053 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7054 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7056 * New targets supported
7058 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7059 68030 and CPU32 m68030-*-*, m68332-*-*
7061 * New native hosts supported
7063 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7064 (386bsd is not well tested yet)
7065 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7067 * New file formats supported
7069 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7070 supports reading of `a.out.adobe' object files, which are an a.out
7071 format extended with minimal information about multiple sections.
7075 `show copying' is the same as the old `info copying'.
7076 `show warranty' is the same as `info warrantee'.
7077 These were renamed for consistency. The old commands continue to work.
7079 `info handle' is a new alias for `info signals'.
7081 You can now define pre-command hooks, which attach arbitrary command
7082 scripts to any command. The commands in the hook will be executed
7083 prior to the user's command. You can also create a hook which will be
7084 executed whenever the program stops. See gdb.texinfo.
7088 We now deal with Cfront style name mangling, and can even extract type
7089 info from mangled symbols. GDB can automatically figure out which
7090 symbol mangling style your C++ compiler uses.
7092 Calling of methods and virtual functions has been improved as well.
7096 The crash that occured when debugging Sun Ansi-C compiled binaries is
7097 fixed. This was due to mishandling of the extra N_SO stabs output
7100 We also finally got Ultrix 4.2 running in house, and fixed core file
7101 support, with help from a dozen people on the net.
7103 John M. Farrell discovered that the reason that single-stepping was so
7104 slow on all of the Mips based platforms (primarily SGI and DEC) was
7105 that we were trying to demangle and lookup a symbol used for internal
7106 purposes on every instruction that was being stepped through. Changing
7107 the name of that symbol so that it couldn't be mistaken for a C++
7108 mangled symbol sped things up a great deal.
7110 Rich Pixley sped up symbol lookups in general by getting much smarter
7111 about when C++ symbol mangling is necessary. This should make symbol
7112 completion (TAB on the command line) much faster. It's not as fast as
7113 we'd like, but it's significantly faster than gdb-4.6.
7117 A new user controllable variable 'call_scratch_address' can
7118 specify the location of a scratch area to be used when GDB
7119 calls a function in the target. This is necessary because the
7120 usual method of putting the scratch area on the stack does not work
7121 in systems that have separate instruction and data spaces.
7123 We integrated changes to support the 29k UDI (Universal Debugger
7124 Interface), but discovered at the last minute that we didn't have all
7125 of the appropriate copyright paperwork. We are working with AMD to
7126 resolve this, and hope to have it available soon.
7130 We have sped up the remote serial line protocol, especially for targets
7131 with lots of registers. It now supports a new `expedited status' ('T')
7132 message which can be used in place of the existing 'S' status message.
7133 This allows the remote stub to send only the registers that GDB
7134 needs to make a quick decision about single-stepping or conditional
7135 breakpoints, eliminating the need to fetch the entire register set for
7136 each instruction being stepped through.
7138 The GDB remote serial protocol now implements a write-through cache for
7139 registers, only re-reading the registers if the target has run.
7141 There is also a new remote serial stub for SPARC processors. You can
7142 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7143 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7144 processor with a serial port.
7148 Configure.in files have become much easier to read and modify. A new
7149 `table driven' format makes it more obvious what configurations are
7150 supported, and what files each one uses.
7154 There is a new opcodes library which will eventually contain all of the
7155 disassembly routines and opcode tables. At present, it only contains
7156 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7157 disassembler (binutils/objdump) to share these routines.
7159 The libiberty library is now copylefted under the GNU Library General
7160 Public License. This allows more liberal use, and was done so libg++
7161 can use it. This makes no difference to GDB, since the Library License
7162 grants all the rights from the General Public License.
7166 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7167 reference to the stabs symbol info used by the debugger. It is (as far
7168 as we know) the only published document on this fascinating topic. We
7169 encourage you to read it, compare it to the stabs information on your
7170 system, and send improvements on the document in general (to
7171 bug-gdb@prep.ai.mit.edu).
7173 And, of course, many bugs have been fixed.
7176 *** Changes in GDB-4.6:
7178 * Better support for C++ function names
7180 GDB now accepts as input the "demangled form" of C++ overloaded function
7181 names and member function names, and can do command completion on such names
7182 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7183 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7184 Make use of command completion, it is your friend.
7186 GDB also now accepts a variety of C++ mangled symbol formats. They are
7187 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7188 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7189 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7190 for the list of formats.
7192 * G++ symbol mangling problem
7194 Recent versions of gcc have a bug in how they emit debugging information for
7195 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7196 directory) can be applied to gcc to fix the problem. Alternatively, if you
7197 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7198 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7199 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7202 * New 'maintenance' command
7204 All of the commands related to hacking GDB internals have been moved out of
7205 the main command set, and now live behind the 'maintenance' command. This
7206 can also be abbreviated as 'mt'. The following changes were made:
7208 dump-me -> maintenance dump-me
7209 info all-breakpoints -> maintenance info breakpoints
7210 printmsyms -> maintenance print msyms
7211 printobjfiles -> maintenance print objfiles
7212 printpsyms -> maintenance print psymbols
7213 printsyms -> maintenance print symbols
7215 The following commands are new:
7217 maintenance demangle Call internal GDB demangler routine to
7218 demangle a C++ link name and prints the result.
7219 maintenance print type Print a type chain for a given symbol
7221 * Change to .gdbinit file processing
7223 We now read the $HOME/.gdbinit file before processing the argv arguments
7224 (e.g. reading symbol files or core files). This allows global parameters to
7225 be set, which will apply during the symbol reading. The ./.gdbinit is still
7226 read after argv processing.
7228 * New hosts supported
7230 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7232 GNU/Linux support i386-unknown-linux or linux
7234 We are also including code to support the HP/PA running BSD and HPUX. This
7235 is almost guaranteed not to work, as we didn't have time to test or build it
7236 for this release. We are including it so that the more adventurous (or
7237 masochistic) of you can play with it. We also had major problems with the
7238 fact that the compiler that we got from HP doesn't support the -g option.
7241 * New targets supported
7243 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7245 * More smarts about finding #include files
7247 GDB now remembers the compilation directory for all include files, and for
7248 all files from which C is generated (like yacc and lex sources). This
7249 greatly improves GDB's ability to find yacc/lex sources, and include files,
7250 especially if you are debugging your program from a directory different from
7251 the one that contains your sources.
7253 We also fixed a bug which caused difficulty with listing and setting
7254 breakpoints in include files which contain C code. (In the past, you had to
7255 try twice in order to list an include file that you hadn't looked at before.)
7257 * Interesting infernals change
7259 GDB now deals with arbitrary numbers of sections, where the symbols for each
7260 section must be relocated relative to that section's landing place in the
7261 target's address space. This work was needed to support ELF with embedded
7262 stabs used by Solaris-2.0.
7264 * Bug fixes (of course!)
7266 There have been loads of fixes for the following things:
7267 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7268 i960, stabs, DOS(GO32), procfs, etc...
7270 See the ChangeLog for details.
7272 *** Changes in GDB-4.5:
7274 * New machines supported (host and target)
7276 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7278 SGI Irix-4.x mips-sgi-irix4 or iris4
7280 * New malloc package
7282 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7283 Mmalloc is capable of handling mutiple heaps of memory. It is also
7284 capable of saving a heap to a file, and then mapping it back in later.
7285 This can be used to greatly speedup the startup of GDB by using a
7286 pre-parsed symbol table which lives in a mmalloc managed heap. For
7287 more details, please read mmalloc/mmalloc.texi.
7291 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7292 'help info proc' for details.
7294 * MIPS ecoff symbol table format
7296 The code that reads MIPS symbol table format is now supported on all hosts.
7297 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7300 * File name changes for MS-DOS
7302 Many files in the config directories have been renamed to make it easier to
7303 support GDB on MS-DOSe systems (which have very restrictive file name
7304 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7305 environment) is close to working but has some remaining problems. Note
7306 that debugging of DOS programs is not supported, due to limitations
7307 in the ``operating system'', but it can be used to host cross-debugging.
7309 * Cross byte order fixes
7311 Many fixes have been made to support cross debugging of Sparc and MIPS
7312 targets from hosts whose byte order differs.
7314 * New -mapped and -readnow options
7316 If memory-mapped files are available on your system through the 'mmap'
7317 system call, you can use the -mapped option on the `file' or
7318 `symbol-file' commands to cause GDB to write the symbols from your
7319 program into a reusable file. If the program you are debugging is
7320 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7321 Future GDB debugging sessions will notice the presence of this file,
7322 and will quickly map in symbol information from it, rather than reading
7323 the symbol table from the executable program. Using the '-mapped'
7324 option in a GDB `file' or `symbol-file' command has the same effect as
7325 starting GDB with the '-mapped' command-line option.
7327 You can cause GDB to read the entire symbol table immediately by using
7328 the '-readnow' option with any of the commands that load symbol table
7329 information (or on the GDB command line). This makes the command
7330 slower, but makes future operations faster.
7332 The -mapped and -readnow options are typically combined in order to
7333 build a `fred.syms' file that contains complete symbol information.
7334 A simple GDB invocation to do nothing but build a `.syms' file for future
7337 gdb -batch -nx -mapped -readnow programname
7339 The `.syms' file is specific to the host machine on which GDB is run.
7340 It holds an exact image of GDB's internal symbol table. It cannot be
7341 shared across multiple host platforms.
7343 * longjmp() handling
7345 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7346 siglongjmp() without losing control. This feature has not yet been ported to
7347 all systems. It currently works on many 386 platforms, all MIPS-based
7348 platforms (SGI, DECstation, etc), and Sun3/4.
7352 Preliminary work has been put in to support the new Solaris OS from Sun. At
7353 this time, it can control and debug processes, but it is not capable of
7358 As always, many many bug fixes. The major areas were with g++, and mipsread.
7359 People using the MIPS-based platforms should experience fewer mysterious
7360 crashes and trashed symbol tables.
7362 *** Changes in GDB-4.4:
7364 * New machines supported (host and target)
7366 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7368 BSD Reno on Vax vax-dec-bsd
7369 Ultrix on Vax vax-dec-ultrix
7371 * New machines supported (target)
7373 AMD 29000 embedded, using EBMON a29k-none-none
7377 GDB continues to improve its handling of C++. `References' work better.
7378 The demangler has also been improved, and now deals with symbols mangled as
7379 per the Annotated C++ Reference Guide.
7381 GDB also now handles `stabs' symbol information embedded in MIPS
7382 `ecoff' symbol tables. Since the ecoff format was not easily
7383 extensible to handle new languages such as C++, this appeared to be a
7384 good way to put C++ debugging info into MIPS binaries. This option
7385 will be supported in the GNU C compiler, version 2, when it is
7388 * New features for SVR4
7390 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7391 shared libraries. Debugging dynamically linked programs should present
7392 only minor differences from debugging statically linked programs.
7394 The `info proc' command will print out information about any process
7395 on an SVR4 system (including the one you are debugging). At the moment,
7396 it prints the address mappings of the process.
7398 If you bring up GDB on another SVR4 system, please send mail to
7399 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7401 * Better dynamic linking support in SunOS
7403 Reading symbols from shared libraries which contain debugging symbols
7404 now works properly. However, there remain issues such as automatic
7405 skipping of `transfer vector' code during function calls, which
7406 make it harder to debug code in a shared library, than to debug the
7407 same code linked statically.
7411 GDB is now using the latest `getopt' routines from the FSF. This
7412 version accepts the -- prefix for options with long names. GDB will
7413 continue to accept the old forms (-option and +option) as well.
7414 Various single letter abbreviations for options have been explicity
7415 added to the option table so that they won't get overshadowed in the
7416 future by other options that begin with the same letter.
7420 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7421 Many assorted bugs have been handled. Many more remain to be handled.
7422 See the various ChangeLog files (primarily in gdb and bfd) for details.
7425 *** Changes in GDB-4.3:
7427 * New machines supported (host and target)
7429 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7430 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7431 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7433 * Almost SCO Unix support
7435 We had hoped to support:
7436 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7437 (except for core file support), but we discovered very late in the release
7438 that it has problems with process groups that render gdb unusable. Sorry
7439 about that. I encourage people to fix it and post the fixes.
7441 * Preliminary ELF and DWARF support
7443 GDB can read ELF object files on System V Release 4, and can handle
7444 debugging records for C, in DWARF format, in ELF files. This support
7445 is preliminary. If you bring up GDB on another SVR4 system, please
7446 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7451 GDB now uses the latest `readline' library. One user-visible change
7452 is that two tabs will list possible command completions, which previously
7453 required typing M-? (meta-question mark, or ESC ?).
7457 The `stepi' bug that many of you noticed has been squashed.
7458 Many bugs in C++ have been handled. Many more remain to be handled.
7459 See the various ChangeLog files (primarily in gdb and bfd) for details.
7461 * State of the MIPS world (in case you wondered):
7463 GDB can understand the symbol tables emitted by the compilers
7464 supplied by most vendors of MIPS-based machines, including DEC. These
7465 symbol tables are in a format that essentially nobody else uses.
7467 Some versions of gcc come with an assembler post-processor called
7468 mips-tfile. This program is required if you want to do source-level
7469 debugging of gcc-compiled programs. I believe FSF does not ship
7470 mips-tfile with gcc version 1, but it will eventually come with gcc
7473 Debugging of g++ output remains a problem. g++ version 1.xx does not
7474 really support it at all. (If you're lucky, you should be able to get
7475 line numbers and stack traces to work, but no parameters or local
7476 variables.) With some work it should be possible to improve the
7479 When gcc version 2 is released, you will have somewhat better luck.
7480 However, even then you will get confusing results for inheritance and
7483 We will eventually provide full debugging of g++ output on
7484 DECstations. This will probably involve some kind of stabs-in-ecoff
7485 encapulation, but the details have not been worked out yet.
7488 *** Changes in GDB-4.2:
7490 * Improved configuration
7492 Only one copy of `configure' exists now, and it is not self-modifying.
7493 Porting BFD is simpler.
7497 The `step' and `next' commands now only stop at the first instruction
7498 of a source line. This prevents the multiple stops that used to occur
7499 in switch statements, for-loops, etc. `Step' continues to stop if a
7500 function that has debugging information is called within the line.
7504 Lots of small bugs fixed. More remain.
7506 * New host supported (not target)
7508 Intel 386 PC clone running Mach i386-none-mach
7511 *** Changes in GDB-4.1:
7513 * Multiple source language support
7515 GDB now has internal scaffolding to handle several source languages.
7516 It determines the type of each source file from its filename extension,
7517 and will switch expression parsing and number formatting to match the
7518 language of the function in the currently selected stack frame.
7519 You can also specifically set the language to be used, with
7520 `set language c' or `set language modula-2'.
7524 GDB now has preliminary support for the GNU Modula-2 compiler,
7525 currently under development at the State University of New York at
7526 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7527 continue through the fall of 1991 and into 1992.
7529 Other Modula-2 compilers are currently not supported, and attempting to
7530 debug programs compiled with them will likely result in an error as the
7531 symbol table is read. Feel free to work on it, though!
7533 There are hooks in GDB for strict type checking and range checking,
7534 in the `Modula-2 philosophy', but they do not currently work.
7538 GDB can now write to executable and core files (e.g. patch
7539 a variable's value). You must turn this switch on, specify
7540 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7541 by assigning a new value to a variable. Modifications take
7544 * Automatic SunOS shared library reading
7546 When you run your program, GDB automatically determines where its
7547 shared libraries (if any) have been loaded, and reads their symbols.
7548 The `share' command is no longer needed. This also works when
7549 examining core files.
7553 You can specify the number of lines that the `list' command shows.
7556 * New machines supported (host and target)
7558 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7559 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7560 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7562 * New hosts supported (not targets)
7564 IBM RT/PC: romp-ibm-aix or rtpc
7566 * New targets supported (not hosts)
7568 AMD 29000 embedded with COFF a29k-none-coff
7569 AMD 29000 embedded with a.out a29k-none-aout
7570 Ultracomputer remote kernel debug a29k-nyu-kern
7572 * New remote interfaces
7578 *** Changes in GDB-4.0:
7582 Wide output is wrapped at good places to make the output more readable.
7584 Gdb now supports cross-debugging from a host machine of one type to a
7585 target machine of another type. Communication with the target system
7586 is over serial lines. The ``target'' command handles connecting to the
7587 remote system; the ``load'' command will download a program into the
7588 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7589 also supports debugging of realtime processes running under VxWorks,
7590 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7591 stub on the target system.
7593 New CPUs supported include the AMD 29000 and Intel 960.
7595 GDB now reads object files and symbol tables via a ``binary file''
7596 library, which allows a single copy of GDB to debug programs of multiple
7597 object file types such as a.out and coff.
7599 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7600 refcard.dvi and refcard.ps are available to format it).
7603 * Control-Variable user interface simplified
7605 All variables that control the operation of the debugger can be set
7606 by the ``set'' command, and displayed by the ``show'' command.
7608 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7609 ``Show prompt'' produces the response:
7610 Gdb's prompt is new-gdb=>.
7612 What follows are the NEW set commands. The command ``help set'' will
7613 print a complete list of old and new set commands. ``help set FOO''
7614 will give a longer description of the variable FOO. ``show'' will show
7615 all of the variable descriptions and their current settings.
7617 confirm on/off: Enables warning questions for operations that are
7618 hard to recover from, e.g. rerunning the program while
7619 it is already running. Default is ON.
7621 editing on/off: Enables EMACS style command line editing
7622 of input. Previous lines can be recalled with
7623 control-P, the current line can be edited with control-B,
7624 you can search for commands with control-R, etc.
7627 history filename NAME: NAME is where the gdb command history
7628 will be stored. The default is .gdb_history,
7629 or the value of the environment variable
7632 history size N: The size, in commands, of the command history. The
7633 default is 256, or the value of the environment variable
7636 history save on/off: If this value is set to ON, the history file will
7637 be saved after exiting gdb. If set to OFF, the
7638 file will not be saved. The default is OFF.
7640 history expansion on/off: If this value is set to ON, then csh-like
7641 history expansion will be performed on
7642 command line input. The default is OFF.
7644 radix N: Sets the default radix for input and output. It can be set
7645 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7646 in the current radix, so "set radix 10" is always a no-op.
7648 height N: This integer value is the number of lines on a page. Default
7649 is 24, the current `stty rows'' setting, or the ``li#''
7650 setting from the termcap entry matching the environment
7653 width N: This integer value is the number of characters on a line.
7654 Default is 80, the current `stty cols'' setting, or the ``co#''
7655 setting from the termcap entry matching the environment
7658 Note: ``set screensize'' is obsolete. Use ``set height'' and
7659 ``set width'' instead.
7661 print address on/off: Print memory addresses in various command displays,
7662 such as stack traces and structure values. Gdb looks
7663 more ``symbolic'' if you turn this off; it looks more
7664 ``machine level'' with it on. Default is ON.
7666 print array on/off: Prettyprint arrays. New convenient format! Default
7669 print demangle on/off: Print C++ symbols in "source" form if on,
7672 print asm-demangle on/off: Same, for assembler level printouts
7675 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7678 * Support for Epoch Environment.
7680 The epoch environment is a version of Emacs v18 with windowing. One
7681 new command, ``inspect'', is identical to ``print'', except that if you
7682 are running in the epoch environment, the value is printed in its own
7686 * Support for Shared Libraries
7688 GDB can now debug programs and core files that use SunOS shared libraries.
7689 Symbols from a shared library cannot be referenced
7690 before the shared library has been linked with the program (this
7691 happens after you type ``run'' and before the function main() is entered).
7692 At any time after this linking (including when examining core files
7693 from dynamically linked programs), gdb reads the symbols from each
7694 shared library when you type the ``sharedlibrary'' command.
7695 It can be abbreviated ``share''.
7697 sharedlibrary REGEXP: Load shared object library symbols for files
7698 matching a unix regular expression. No argument
7699 indicates to load symbols for all shared libraries.
7701 info sharedlibrary: Status of loaded shared libraries.
7706 A watchpoint stops execution of a program whenever the value of an
7707 expression changes. Checking for this slows down execution
7708 tremendously whenever you are in the scope of the expression, but is
7709 quite useful for catching tough ``bit-spreader'' or pointer misuse
7710 problems. Some machines such as the 386 have hardware for doing this
7711 more quickly, and future versions of gdb will use this hardware.
7713 watch EXP: Set a watchpoint (breakpoint) for an expression.
7715 info watchpoints: Information about your watchpoints.
7717 delete N: Deletes watchpoint number N (same as breakpoints).
7718 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7719 enable N: Re-enables watchpoint number N (same as breakpoints).
7722 * C++ multiple inheritance
7724 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7727 * C++ exception handling
7729 Gdb now supports limited C++ exception handling. Besides the existing
7730 ability to breakpoint on an exception handler, gdb can breakpoint on
7731 the raising of an exception (before the stack is peeled back to the
7734 catch FOO: If there is a FOO exception handler in the dynamic scope,
7735 set a breakpoint to catch exceptions which may be raised there.
7736 Multiple exceptions (``catch foo bar baz'') may be caught.
7738 info catch: Lists all exceptions which may be caught in the
7739 current stack frame.
7742 * Minor command changes
7744 The command ``call func (arg, arg, ...)'' now acts like the print
7745 command, except it does not print or save a value if the function's result
7746 is void. This is similar to dbx usage.
7748 The ``up'' and ``down'' commands now always print the frame they end up
7749 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7750 frames without printing.
7752 * New directory command
7754 'dir' now adds directories to the FRONT of the source search path.
7755 The path starts off empty. Source files that contain debug information
7756 about the directory in which they were compiled can be found even
7757 with an empty path; Sun CC and GCC include this information. If GDB can't
7758 find your source file in the current directory, type "dir .".
7760 * Configuring GDB for compilation
7762 For normal use, type ``./configure host''. See README or gdb.texinfo
7765 GDB now handles cross debugging. If you are remotely debugging between
7766 two different machines, type ``./configure host -target=targ''.
7767 Host is the machine where GDB will run; targ is the machine
7768 where the program that you are debugging will run.