1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
15 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
16 of the GDB settings and the GDB maintenance settings. They are handy
17 for changing the logic of user defined commands depending on the
20 * GDB now supports Thread Local Storage (TLS) variables on several
21 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
22 architectures require kernel changes. TLS is not yet supported for
23 amd64 and i386 process core dumps.
25 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
26 addresses that required unmasking are shown in the backtrace with the
29 * Two new convenience functions $_cimag and $_creal that extract the
30 imaginary and real parts respectively from complex numbers.
32 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
33 provide the exitcode or exit status of the shell commands launched by
34 GDB commands such as "shell", "pipe" and "make".
36 * The RX port now supports XML target descriptions.
38 * GDB now shows the Ada task names at more places, e.g. in task switching
41 * GDB can now be compiled with Python 3 on Windows.
43 * New convenience variable $_ada_exception holds the address of the
44 Ada exception being thrown. This is set by Ada-related catchpoints.
46 * GDB can now place breakpoints on nested functions and subroutines in
47 Fortran code. The '::' operator can be used between parent and
48 child scopes when placing breakpoints, for example:
50 (gdb) break outer_function::inner_function
52 The 'outer_function::' prefix is only needed if 'inner_function' is
53 not visible in the current scope.
55 * In addition to the system-wide gdbinit file, if configured with
56 --with-system-gdbinit-dir, GDB will now also load files in that directory
57 as system gdbinit files, unless the -nx or -n flag is provided. Files
58 with extensions .gdb, .py and .scm are supported as long as GDB was
59 compiled with support for that language.
63 ** The gdb.Value type has a new method 'format_string' which returns a
64 string representing the value. The formatting is controlled by the
65 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
66 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
67 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
69 ** gdb.Type has a new property 'objfile' which returns the objfile the
72 ** The frame information printed by the python frame filtering code
73 is now consistent with what the 'backtrace' command prints when
74 there are no filters, or when the 'backtrace' '-no-filters' option
77 ** The new function gdb.lookup_static_symbol can be used to look up
78 symbols with static linkage.
80 ** The new function gdb.lookup_static_symbols can be used to look up
81 all static symbols with static linkage.
83 ** gdb.Objfile has new methods 'lookup_global_symbol' and
84 'lookup_static_symbol' to lookup a symbol from this objfile only.
86 ** gdb.Block now supports the dictionary syntax for accessing symbols in
87 this block (e.g. block['local_variable']).
91 | [COMMAND] | SHELL_COMMAND
92 | -d DELIM COMMAND DELIM SHELL_COMMAND
93 pipe [COMMAND] | SHELL_COMMAND
94 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
95 Executes COMMAND and sends its output to SHELL_COMMAND.
96 With no COMMAND, repeat the last executed command
97 and send its output to SHELL_COMMAND.
99 with SETTING [VALUE] [-- COMMAND]
100 w SETTING [VALUE] [-- COMMAND]
101 Temporarily set SETTING, run COMMAND, and restore SETTING.
102 Usage: with SETTING -- COMMAND
103 With no COMMAND, repeats the last executed command.
104 SETTING is any GDB setting you can change with the "set"
105 subcommands. For example, 'with language c -- print someobj'
106 temporarily switches to the C language in order to print someobj.
107 Settings can be combined: 'w lang c -- w print elements unlimited --
108 usercmd' switches to the C language and runs usercmd with no limit
109 of array elements to print.
111 maint with SETTING [VALUE] [-- COMMAND]
112 Like "with", but works with "maintenance set" settings.
114 set may-call-functions [on|off]
115 show may-call-functions
116 This controls whether GDB will attempt to call functions in
117 the program, such as with expressions in the print command. It
118 defaults to on. Calling functions in the program being debugged
119 can have undesired side effects. It is now possible to forbid
120 such function calls. If function calls are forbidden, GDB will throw
121 an error when a command (such as print expression) calls a function
124 set print finish [on|off]
126 This controls whether the `finish' command will display the value
127 that is returned by the current function. When `off', the value is
128 still entered into the value history, but it is not printed. The
133 Allows deeply nested structures to be simplified when printing by
134 replacing deeply nested parts (beyond the max-depth) with ellipses.
135 The default max-depth is 20, but this can be set to unlimited to get
136 the old behavior back.
138 set logging debugredirect [on|off]
139 By default, GDB debug output will go to both the terminal and the logfile.
140 Set if you want debug output to go only to the log file.
142 set style title foreground COLOR
143 set style title background COLOR
144 set style title intensity VALUE
145 Control the styling of titles.
147 set style highlight foreground COLOR
148 set style highlight background COLOR
149 set style highlight intensity VALUE
150 Control the styling of highlightings.
152 maint set worker-threads
153 maint show worker-threads
154 Control the number of worker threads that can be used by GDB. The
155 default is "unlimited", which lets GDB choose a number that is
156 reasonable. Currently worker threads are only used when demangling
157 the names of linker symbols.
159 maint set test-settings KIND
160 maint show test-settings KIND
161 A set of commands used by the testsuite for exercising the settings
164 maint set tui-resize-message [on|off]
165 maint show tui-resize-message
166 Control whether GDB prints a message each time the terminal is
167 resized when in TUI mode. This is primarily useful for testing the
170 set print frame-info [short-location|location|location-and-address
171 |source-and-location|source-line|auto]
172 show print frame-info
173 This controls what frame information is printed by the commands printing
174 a frame. This setting will e.g. influence the behaviour of 'backtrace',
175 'frame', 'stepi'. The python frame filtering also respect this setting.
176 The 'backtrace' '-frame-info' option can override this global setting.
178 info modules [-q] [REGEXP]
179 Return a list of Fortran modules matching REGEXP, or all modules if
182 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
183 Return a list of functions within all modules, grouped by module.
184 The list of functions can be restricted with the optional regular
185 expressions. MODULE_REGEXP matches against the module name,
186 TYPE_REGEXP matches against the function type signature, and REGEXP
187 matches against the function name.
189 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
190 Return a list of variables within all modules, grouped by module.
191 The list of variables can be restricted with the optional regular
192 expressions. MODULE_REGEXP matches against the module name,
193 TYPE_REGEXP matches against the variable type, and REGEXP matches
194 against the variable name.
196 set debug remote-packet-max-chars
197 show debug remote-packet-max-chars
198 Controls the number of characters to output in a remote packet when using
200 The default is 512 bytes.
205 The "help" command uses the title style to enhance the
206 readibility of its output by styling the classes and
210 Similarly to "help", the "apropos" command also uses the
211 title style for the command names. "apropos" accepts now
212 a flag "-v" (verbose) to show the full documentation
213 of matching commands and to use the highlight style to mark
214 the documentation parts matching REGEXP.
218 The GDB printf and eval commands can now print C-style and Ada-style
219 string convenience variables without calling functions in the program.
220 This allows to do formatted printing of strings without having
221 a running inferior, or when debugging a core dump.
223 info sources [-dirname | -basename] [--] [REGEXP]
224 This command has now optional arguments to only print the files
225 whose names match REGEXP. The arguments -dirname and -basename
226 allow to restrict matching respectively to the dirname and basename
230 The "show style" and its subcommands are now styling
231 a style name in their output using its own style, to help
232 the user visualize the different styles.
234 set print frame-arguments
235 The new value 'presence' indicates to only indicate the presence of
236 arguments using ..., instead of printing argument names and values.
238 set print raw-frame-arguments
239 show print raw-frame-arguments
241 These commands replace the similarly-named "set/show print raw
242 frame-arguments" commands (now with a dash instead of a space). The
243 old commands are now deprecated and may be removed in a future
246 maint test-options require-delimiter
247 maint test-options unknown-is-error
248 maint test-options unknown-is-operand
249 maint show test-options-completion-result
250 Commands used by the testsuite to validate the command options
253 focus, winheight, +, -, >, <
254 These commands are now case-sensitive.
256 * New command options, command completion
258 GDB now has a standard infrastructure to support dash-style command
259 options ('-OPT'). One benefit is that commands that use it can
260 easily support completion of command line arguments. Try "CMD
261 -[TAB]" or "help CMD" to find options supported by a command. Over
262 time, we intend to migrate most commands to this infrastructure. A
263 number of commands got support for new command options in this
266 ** The "print" and "compile print" commands now support a number of
267 options that allow overriding relevant global print settings as
268 set by "set print" subcommands:
272 -array-indexes [on|off]
273 -elements NUMBER|unlimited
277 -repeats NUMBER|unlimited
278 -static-members [on|off]
283 Note that because the "print"/"compile print" commands accept
284 arbitrary expressions which may look like options (including
285 abbreviations), if you specify any command option, then you must
286 use a double dash ("--") to mark the end of argument processing.
288 ** The "backtrace" command now supports a number of options that
289 allow overriding relevant global print settings as set by "set
290 backtrace" and "set print" subcommands:
292 -entry-values no|only|preferred|if-needed|both|compact|default
293 -frame-arguments all|scalars|none
294 -raw-frame-arguments [on|off]
295 -frame-info auto|source-line|location|source-and-location
296 |location-and-address|short-location
300 In addition, the full/no-filters/hide qualifiers are now also
301 exposed as command options too:
307 ** The "frame apply", "tfaas" and "faas" commands similarly now
308 support the following options:
313 ** The new "info sources" options -dirname and -basename options
314 are using the standard '-OPT' infrastructure.
316 All options above can also be abbreviated. The argument of boolean
317 (on/off) options can be 0/1 too, and also the argument is assumed
318 "on" if omitted. This allows writing compact command invocations,
321 (gdb) p -r -p -o 0 -- *myptr
323 The above is equivalent to:
325 (gdb) print -raw -pretty -object off -- *myptr
327 ** The "info types" command now supports the '-q' flag to disable
328 printing of some header information in a similar fashion to "info
329 variables" and "info functions".
331 ** The "info variables", "info functions", and "whereis" commands
332 now take a '-n' flag that excludes non-debug symbols (symbols
333 from the symbol table, not from the debug info such as DWARF)
336 * Completion improvements
338 ** GDB can now complete the options of the "thread apply all" and
339 "taas" commands, and their "-ascending" option can now be
342 ** GDB can now complete the options of the "info threads", "info
343 functions", "info variables", "info locals", and "info args"
346 ** GDB can now complete the options of the "compile file" and
347 "compile code" commands. The "compile file" command now
348 completes on filenames.
350 ** GDB can now complete the backtrace command's
351 "full/no-filters/hide" qualifiers.
353 * In settings, you can now abbreviate "unlimited".
355 E.g., "set print elements u" is now equivalent to "set print
361 This lists all the possible completions for the rest of the line, if it
362 were to be given as a command itself. This is intended for use by MI
363 frontends in cases when separate CLI and MI channels cannot be used.
365 -catch-throw, -catch-rethrow, and -catch-catch
366 These can be used to catch C++ exceptions in a similar fashion to
367 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
369 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
370 These commands are the MI equivalent of the CLI commands 'info
371 functions', 'info types', and 'info variables' respectively.
375 ** The default version of the MI interpreter is now 3 (-i=mi3).
377 ** The output of information about multi-location breakpoints (which is
378 syntactically incorrect in MI 2) has changed in MI 3. This affects
379 the following commands and events:
383 - =breakpoint-created
384 - =breakpoint-modified
386 The -fix-multi-location-breakpoint-output command can be used to enable
387 this behavior with previous MI versions.
389 ** Backtraces and frames include a new optional field addr_flags which is
390 given after the addr field. On AArch64 this contains PAC if the address
391 has been masked in the frame. On all other targets the field is not
396 The testsuite now creates the files gdb.cmd (containing the arguments
397 used to launch GDB) and gdb.in (containing all the commands sent to
398 GDB) in the output directory for each test script. Multiple invocations
399 are appended with .1, .2, .3 etc.
401 * Building GDB and GDBserver now requires GNU make >= 3.82.
403 Using another implementation of the make program or an earlier version of
404 GNU make to build GDB or GDBserver is not supported.
406 * Building GDB now requires GNU readline >= 7.0.
408 GDB now bundles GNU readline 8.0, but if you choose to use
409 --with-system-readline, only readline >= 7.0 can be used.
411 * The TUI SingleKey keymap is now named "SingleKey". This can be used
412 from .inputrc to bind keys in this keymap. This feature is only
413 available when gdb is built against GNU readline 8.0 or later.
415 * Removed targets and native configurations
417 GDB no longer supports debugging the Cell Broadband Engine. This includes
418 both debugging standalone Cell/B.E. SPU applications and integrated debugging
419 of Cell/B.E. applications that use both the PPU and SPU architectures.
425 * Removed targets and native configurations
427 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
430 *** Changes in GDB 8.3
432 * GDB and GDBserver now support access to additional registers on
433 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
436 * GDB now has experimental support for the compilation and injection of
437 C++ source code into the inferior. This beta release does not include
438 support for several language features, such as templates, constructors,
441 This feature requires GCC 7.1 or higher built with libcp1.so
444 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
445 can be passed using the '[ADDRESS]:PORT' notation, or the regular
446 'ADDRESS:PORT' method.
448 * DWARF index cache: GDB can now automatically save indices of DWARF
449 symbols on disk to speed up further loading of the same binaries.
451 * Ada task switching is now supported on aarch64-elf targets when
452 debugging a program using the Ravenscar Profile. For more information,
453 see the "Tasking Support when using the Ravenscar Profile" section
454 in the GDB user manual.
456 * GDB in batch mode now exits with status 1 if the last command to be
459 * The RISC-V target now supports target descriptions.
461 * System call catchpoints now support system call aliases on FreeBSD.
462 When the ABI of a system call changes in FreeBSD, this is
463 implemented by leaving a compatibility system call using the old ABI
464 at the existing number and allocating a new system call number for
465 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
466 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
467 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
468 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
469 so that a system call catchpoint for the 'kevent' system call will
470 catch invocations of both the 'kevent' and 'freebsd11_kevent'
471 binaries. This ensures that 'kevent' system calls are caught for
472 binaries using either the old or new ABIs.
474 * Terminal styling is now available for the CLI and the TUI. GNU
475 Source Highlight can additionally be used to provide styling of
476 source code snippets. See the "set style" commands, below, for more
479 * Removed support for old demangling styles arm, edg, gnu, hp and
484 set debug compile-cplus-types
485 show debug compile-cplus-types
486 Control the display of debug output about type conversion in the
487 C++ compile feature. Commands have no effect while compiliong
492 Control whether debug output about files/functions skipping is
495 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
496 Apply a command to some frames.
497 FLAG arguments allow to control what output to produce and how to handle
498 errors raised when applying COMMAND to a frame.
501 Apply a command to all threads (ignoring errors and empty output).
502 Shortcut for 'thread apply all -s COMMAND'.
505 Apply a command to all frames (ignoring errors and empty output).
506 Shortcut for 'frame apply all -s COMMAND'.
509 Apply a command to all frames of all threads (ignoring errors and empty
511 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
513 maint set dwarf unwinders (on|off)
514 maint show dwarf unwinders
515 Control whether DWARF unwinders can be used.
518 Display a list of open files for a process.
522 Changes to the "frame", "select-frame", and "info frame" CLI commands.
523 These commands all now take a frame specification which
524 is either a frame level, or one of the keywords 'level', 'address',
525 'function', or 'view' followed by a parameter. Selecting a frame by
526 address, or viewing a frame outside the current backtrace now
527 requires the use of a keyword. Selecting a frame by level is
528 unchanged. The MI comment "-stack-select-frame" is unchanged.
530 target remote FILENAME
531 target extended-remote FILENAME
532 If FILENAME is a Unix domain socket, GDB will attempt to connect
533 to this socket instead of opening FILENAME as a character device.
535 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
536 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
537 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
538 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
539 These commands can now print only the searched entities
540 matching the provided regexp(s), giving a condition
541 on the entity names or entity types. The flag -q disables
542 printing headers or informations messages.
548 These commands now determine the syntax for the shown entities
549 according to the language chosen by `set language'. In particular,
550 `set language auto' means to automatically choose the language of
553 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
554 The 'thread apply' command accepts new FLAG arguments.
555 FLAG arguments allow to control what output to produce and how to handle
556 errors raised when applying COMMAND to a thread.
558 set tui tab-width NCHARS
559 show tui tab-width NCHARS
560 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
562 set style enabled [on|off]
564 Enable or disable terminal styling. Styling is enabled by default
565 on most hosts, but disabled by default when in batch mode.
567 set style sources [on|off]
569 Enable or disable source code styling. Source code styling is
570 enabled by default, but only takes effect if styling in general is
571 enabled, and if GDB was linked with GNU Source Highlight.
573 set style filename foreground COLOR
574 set style filename background COLOR
575 set style filename intensity VALUE
576 Control the styling of file names.
578 set style function foreground COLOR
579 set style function background COLOR
580 set style function intensity VALUE
581 Control the styling of function names.
583 set style variable foreground COLOR
584 set style variable background COLOR
585 set style variable intensity VALUE
586 Control the styling of variable names.
588 set style address foreground COLOR
589 set style address background COLOR
590 set style address intensity VALUE
591 Control the styling of addresses.
595 ** The '-data-disassemble' MI command now accepts an '-a' option to
596 disassemble the whole function surrounding the given program
597 counter value or function name. Support for this feature can be
598 verified by using the "-list-features" command, which should
599 contain "data-disassemble-a-option".
601 ** Command responses and notifications that include a frame now include
602 the frame's architecture in a new "arch" attribute.
604 * New native configurations
606 GNU/Linux/RISC-V riscv*-*-linux*
607 FreeBSD/riscv riscv*-*-freebsd*
611 GNU/Linux/RISC-V riscv*-*-linux*
613 CSKY GNU/LINUX csky*-*-linux
614 FreeBSD/riscv riscv*-*-freebsd*
616 GNU/Linux/OpenRISC or1k*-*-linux*
620 GDB no longer supports native debugging on versions of MS-Windows
625 ** GDB no longer supports Python versions less than 2.6.
627 ** The gdb.Inferior type has a new 'progspace' property, which is the program
628 space associated to that inferior.
630 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
631 of objfiles associated to that program space.
633 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
634 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
637 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
638 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
639 correct and did not work properly.
641 ** The gdb.Value type has a new constructor, which is used to construct a
642 gdb.Value from a Python buffer object and a gdb.Type.
648 Enable or disable the undefined behavior sanitizer. This is
649 disabled by default, but passing --enable-ubsan=yes or
650 --enable-ubsan=auto to configure will enable it. Enabling this can
651 cause a performance penalty. The undefined behavior sanitizer was
652 first introduced in GCC 4.9.
654 *** Changes in GDB 8.2
656 * The 'set disassembler-options' command now supports specifying options
659 * The 'symbol-file' command now accepts an '-o' option to add a relative
660 offset to all sections.
662 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
663 a relative offset to all sections, but it allows to override the load
664 address of individual sections using '-s'.
666 * The 'add-symbol-file' command no longer requires the second argument
667 (address of the text section).
669 * The endianness used with the 'set endian auto' mode in the absence of
670 an executable selected for debugging is now the last endianness chosen
671 either by one of the 'set endian big' and 'set endian little' commands
672 or by inferring from the last executable used, rather than the startup
675 * The pager now allows a "c" response, meaning to disable the pager
676 for the rest of the current command.
678 * The commands 'info variables/functions/types' now show the source line
679 numbers of symbol definitions when available.
681 * 'info proc' now works on running processes on FreeBSD systems and core
682 files created on FreeBSD systems.
684 * C expressions can now use _Alignof, and C++ expressions can now use
687 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
688 the vector length while the process is running.
694 Control display of debugging info regarding the FreeBSD native target.
696 set|show varsize-limit
697 This new setting allows the user to control the maximum size of Ada
698 objects being printed when those objects have a variable type,
699 instead of that maximum size being hardcoded to 65536 bytes.
701 set|show record btrace cpu
702 Controls the processor to be used for enabling errata workarounds for
705 maint check libthread-db
706 Run integrity checks on the current inferior's thread debugging
709 maint set check-libthread-db (on|off)
710 maint show check-libthread-db
711 Control whether to run integrity checks on inferior specific thread
712 debugging libraries as they are loaded. The default is not to
717 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
719 ** The commands attached to a breakpoint can be set by assigning to
720 the breakpoint's "commands" field.
722 ** gdb.execute can now execute multi-line gdb commands.
724 ** The new functions gdb.convenience_variable and
725 gdb.set_convenience_variable can be used to get and set the value
726 of convenience variables.
728 ** A gdb.Parameter will no longer print the "set" help text on an
729 ordinary "set"; instead by default a "set" will be silent unless
730 the get_set_string method returns a non-empty string.
734 RiscV ELF riscv*-*-elf
736 * Removed targets and native configurations
738 m88k running OpenBSD m88*-*-openbsd*
739 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
740 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
741 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
743 * Aarch64/Linux hardware watchpoints improvements
745 Hardware watchpoints on unaligned addresses are now properly
746 supported when running Linux kernel 4.10 or higher: read and access
747 watchpoints are no longer spuriously missed, and all watchpoints
748 lengths between 1 and 8 bytes are supported. On older kernels,
749 watchpoints set on unaligned addresses are no longer missed, with
750 the tradeoff that there is a possibility of false hits being
755 --enable-codesign=CERT
756 This can be used to invoke "codesign -s CERT" after building gdb.
757 This option is useful on macOS, where code signing is required for
758 gdb to work properly.
760 --disable-gdbcli has been removed
761 This is now silently accepted, but does nothing.
763 *** Changes in GDB 8.1
765 * GDB now supports dynamically creating arbitrary register groups specified
766 in XML target descriptions. This allows for finer grain grouping of
767 registers on systems with a large amount of registers.
769 * The 'ptype' command now accepts a '/o' flag, which prints the
770 offsets and sizes of fields in a struct, like the pahole(1) tool.
772 * New "--readnever" command line option instructs GDB to not read each
773 symbol file's symbolic debug information. This makes startup faster
774 but at the expense of not being able to perform symbolic debugging.
775 This option is intended for use cases where symbolic debugging will
776 not be used, e.g., when you only need to dump the debuggee's core.
778 * GDB now uses the GNU MPFR library, if available, to emulate target
779 floating-point arithmetic during expression evaluation when the target
780 uses different floating-point formats than the host. At least version
781 3.1 of GNU MPFR is required.
783 * GDB now supports access to the guarded-storage-control registers and the
784 software-based guarded-storage broadcast control registers on IBM z14.
786 * On Unix systems, GDB now supports transmitting environment variables
787 that are to be set or unset to GDBserver. These variables will
788 affect the environment to be passed to the remote inferior.
790 To inform GDB of environment variables that are to be transmitted to
791 GDBserver, use the "set environment" command. Only user set
792 environment variables are sent to GDBserver.
794 To inform GDB of environment variables that are to be unset before
795 the remote inferior is started by the GDBserver, use the "unset
796 environment" command.
798 * Completion improvements
800 ** GDB can now complete function parameters in linespecs and
801 explicit locations without quoting. When setting breakpoints,
802 quoting around functions names to help with TAB-completion is
803 generally no longer necessary. For example, this now completes
806 (gdb) b function(in[TAB]
807 (gdb) b function(int)
809 Related, GDB is no longer confused with completing functions in
810 C++ anonymous namespaces:
813 (gdb) b (anonymous namespace)::[TAB][TAB]
814 (anonymous namespace)::a_function()
815 (anonymous namespace)::b_function()
817 ** GDB now has much improved linespec and explicit locations TAB
818 completion support, that better understands what you're
819 completing and offers better suggestions. For example, GDB no
820 longer offers data symbols as possible completions when you're
821 setting a breakpoint.
823 ** GDB now TAB-completes label symbol names.
825 ** The "complete" command now mimics TAB completion accurately.
827 * New command line options (gcore)
830 Dump all memory mappings.
832 * Breakpoints on C++ functions are now set on all scopes by default
834 By default, breakpoints on functions/methods are now interpreted as
835 specifying all functions with the given name ignoring missing
836 leading scopes (namespaces and classes).
838 For example, assuming a C++ program with symbols named:
843 both commands "break func()" and "break B::func()" set a breakpoint
846 You can use the new flag "-qualified" to override this. This makes
847 GDB interpret the specified function name as a complete
848 fully-qualified name instead. For example, using the same C++
849 program, the "break -q B::func" command sets a breakpoint on
850 "B::func", only. A parameter has been added to the Python
851 gdb.Breakpoint constructor to achieve the same result when creating
852 a breakpoint from Python.
854 * Breakpoints on functions marked with C++ ABI tags
856 GDB can now set breakpoints on functions marked with C++ ABI tags
857 (e.g., [abi:cxx11]). See here for a description of ABI tags:
858 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
860 Functions with a C++11 abi tag are demangled/displayed like this:
862 function[abi:cxx11](int)
865 You can now set a breakpoint on such functions simply as if they had
868 (gdb) b function(int)
870 Or if you need to disambiguate between tags, like:
872 (gdb) b function[abi:other_tag](int)
874 Tab completion was adjusted accordingly as well.
878 ** New events gdb.new_inferior, gdb.inferior_deleted, and
879 gdb.new_thread are emitted. See the manual for further
880 description of these.
882 ** A new function, "gdb.rbreak" has been added to the Python API.
883 This function allows the setting of a large number of breakpoints
884 via a regex pattern in Python. See the manual for further details.
886 ** Python breakpoints can now accept explicit locations. See the
887 manual for a further description of this feature.
890 * New features in the GDB remote stub, GDBserver
892 ** GDBserver is now able to start inferior processes with a
893 specified initial working directory.
895 The user can set the desired working directory to be used from
896 GDB using the new "set cwd" command.
898 ** New "--selftest" command line option runs some GDBserver self
899 tests. These self tests are disabled in releases.
901 ** On Unix systems, GDBserver now does globbing expansion and variable
902 substitution in inferior command line arguments.
904 This is done by starting inferiors using a shell, like GDB does.
905 See "set startup-with-shell" in the user manual for how to disable
906 this from GDB when using "target extended-remote". When using
907 "target remote", you can disable the startup with shell by using the
908 new "--no-startup-with-shell" GDBserver command line option.
910 ** On Unix systems, GDBserver now supports receiving environment
911 variables that are to be set or unset from GDB. These variables
912 will affect the environment to be passed to the inferior.
914 * When catching an Ada exception raised with a message, GDB now prints
915 the message in the catchpoint hit notification. In GDB/MI mode, that
916 information is provided as an extra field named "exception-message"
917 in the *stopped notification.
919 * Trait objects can now be inspected When debugging Rust code. This
920 requires compiler support which will appear in Rust 1.24.
924 QEnvironmentHexEncoded
925 Inform GDBserver of an environment variable that is to be passed to
926 the inferior when starting it.
929 Inform GDBserver of an environment variable that is to be unset
930 before starting the remote inferior.
933 Inform GDBserver that the environment should be reset (i.e.,
934 user-set environment variables should be unset).
937 Indicates whether the inferior must be started with a shell or not.
940 Tell GDBserver that the inferior to be started should use a specific
943 * The "maintenance print c-tdesc" command now takes an optional
944 argument which is the file name of XML target description.
946 * The "maintenance selftest" command now takes an optional argument to
947 filter the tests to be run.
949 * The "enable", and "disable" commands now accept a range of
950 breakpoint locations, e.g. "enable 1.3-5".
955 Set and show the current working directory for the inferior.
958 Set and show compilation command used for compiling and injecting code
959 with the 'compile' commands.
961 set debug separate-debug-file
962 show debug separate-debug-file
963 Control the display of debug output about separate debug file search.
965 set dump-excluded-mappings
966 show dump-excluded-mappings
967 Control whether mappings marked with the VM_DONTDUMP flag should be
968 dumped when generating a core file.
971 List the registered selftests.
974 Start the debugged program stopping at the first instruction.
977 Control display of debugging messages related to OpenRISC targets.
979 set|show print type nested-type-limit
980 Set and show the limit of nesting level for nested types that the
981 type printer will show.
983 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
986 * Safer/improved support for debugging with no debug info
988 GDB no longer assumes functions with no debug information return
991 This means that GDB now refuses to call such functions unless you
992 tell it the function's type, by either casting the call to the
993 declared return type, or by casting the function to a function
994 pointer of the right type, and calling that:
996 (gdb) p getenv ("PATH")
997 'getenv' has unknown return type; cast the call to its declared return type
998 (gdb) p (char *) getenv ("PATH")
999 $1 = 0x7fffffffe "/usr/local/bin:/"...
1000 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1001 $2 = 0x7fffffffe "/usr/local/bin:/"...
1003 Similarly, GDB no longer assumes that global variables with no debug
1004 info have type 'int', and refuses to print the variable's value
1005 unless you tell it the variable's type:
1008 'var' has unknown type; cast it to its declared type
1012 * New native configurations
1014 FreeBSD/aarch64 aarch64*-*-freebsd*
1015 FreeBSD/arm arm*-*-freebsd*
1019 FreeBSD/aarch64 aarch64*-*-freebsd*
1020 FreeBSD/arm arm*-*-freebsd*
1021 OpenRISC ELF or1k*-*-elf
1023 * Removed targets and native configurations
1025 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1027 *** Changes in GDB 8.0
1029 * GDB now supports access to the PKU register on GNU/Linux. The register is
1030 added by the Memory Protection Keys for Userspace feature which will be
1031 available in future Intel CPUs.
1033 * GDB now supports C++11 rvalue references.
1037 ** New functions to start, stop and access a running btrace recording.
1038 ** Rvalue references are now supported in gdb.Type.
1040 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1043 * Building GDB and GDBserver now requires a C++11 compiler.
1045 For example, GCC 4.8 or later.
1047 It is no longer possible to build GDB or GDBserver with a C
1048 compiler. The --disable-build-with-cxx configure option has been
1051 * Building GDB and GDBserver now requires GNU make >= 3.81.
1053 It is no longer supported to build GDB or GDBserver with another
1054 implementation of the make program or an earlier version of GNU make.
1056 * Native debugging on MS-Windows supports command-line redirection
1058 Command-line arguments used for starting programs on MS-Windows can
1059 now include redirection symbols supported by native Windows shells,
1060 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1061 as "run", "start", and "set args", as well as the corresponding MI
1064 * Support for thread names on MS-Windows.
1066 GDB now catches and handles the special exception that programs
1067 running on MS-Windows use to assign names to threads in the
1070 * Support for Java programs compiled with gcj has been removed.
1072 * User commands now accept an unlimited number of arguments.
1073 Previously, only up to 10 was accepted.
1075 * The "eval" command now expands user-defined command arguments.
1077 This makes it easier to process a variable number of arguments:
1082 eval "print $arg%d", $i
1087 * Target descriptions can now describe registers for sparc32 and sparc64.
1089 * GDB now supports DWARF version 5 (debug information format).
1090 Its .debug_names index is not yet supported.
1092 * New native configurations
1094 FreeBSD/mips mips*-*-freebsd
1098 Synopsys ARC arc*-*-elf32
1099 FreeBSD/mips mips*-*-freebsd
1101 * Removed targets and native configurations
1103 Alpha running FreeBSD alpha*-*-freebsd*
1104 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1109 Erases all the flash memory regions reported by the target.
1111 maint print arc arc-instruction address
1112 Print internal disassembler information about instruction at a given address.
1116 set disassembler-options
1117 show disassembler-options
1118 Controls the passing of target specific information to the disassembler.
1119 If it is necessary to specify more than one disassembler option then
1120 multiple options can be placed together into a comma separated list.
1121 The default value is the empty string. Currently, the only supported
1122 targets are ARM, PowerPC and S/390.
1127 Erases all the flash memory regions reported by the target. This is
1128 equivalent to the CLI command flash-erase.
1130 -file-list-shared-libraries
1131 List the shared libraries in the program. This is
1132 equivalent to the CLI command "info shared".
1135 Catchpoints stopping the program when Ada exceptions are
1136 handled. This is equivalent to the CLI command "catch handlers".
1138 *** Changes in GDB 7.12
1140 * GDB and GDBserver now build with a C++ compiler by default.
1142 The --enable-build-with-cxx configure option is now enabled by
1143 default. One must now explicitly configure with
1144 --disable-build-with-cxx in order to build with a C compiler. This
1145 option will be removed in a future release.
1147 * GDBserver now supports recording btrace without maintaining an active
1150 * GDB now supports a negative repeat count in the 'x' command to examine
1151 memory backward from the given address. For example:
1154 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1155 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1156 (gdb) x/-5i 0x0000000000400580
1157 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1158 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1159 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1160 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1161 0x40057b <main(int, char**)+25>:
1162 callq 0x400536 <Func1(int, char const*)>
1164 * Fortran: Support structures with fields of dynamic types and
1165 arrays of dynamic types.
1167 * The symbol dumping maintenance commands have new syntax.
1168 maint print symbols [-pc address] [--] [filename]
1169 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1170 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1171 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1172 maint print msymbols [-objfile objfile] [--] [filename]
1174 * GDB now supports multibit bitfields and enums in target register
1177 * New Python-based convenience function $_as_string(val), which returns
1178 the textual representation of a value. This function is especially
1179 useful to obtain the text label of an enum value.
1181 * Intel MPX bound violation handling.
1183 Segmentation faults caused by a Intel MPX boundary violation
1184 now display the kind of violation (upper or lower), the memory
1185 address accessed and the memory bounds, along with the usual
1186 signal received and code location.
1190 Program received signal SIGSEGV, Segmentation fault
1191 Upper bound violation while accessing address 0x7fffffffc3b3
1192 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1193 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1195 * Rust language support.
1196 GDB now supports debugging programs written in the Rust programming
1197 language. See https://www.rust-lang.org/ for more information about
1200 * Support for running interpreters on specified input/output devices
1202 GDB now supports a new mechanism that allows frontends to provide
1203 fully featured GDB console views, as a better alternative to
1204 building such views on top of the "-interpreter-exec console"
1205 command. See the new "new-ui" command below. With that command,
1206 frontends can now start GDB in the traditional command-line mode
1207 running in an embedded terminal emulator widget, and create a
1208 separate MI interpreter running on a specified i/o device. In this
1209 way, GDB handles line editing, history, tab completion, etc. in the
1210 console all by itself, and the GUI uses the separate MI interpreter
1211 for its own control and synchronization, invisible to the command
1214 * The "catch syscall" command catches groups of related syscalls.
1216 The "catch syscall" command now supports catching a group of related
1217 syscalls using the 'group:' or 'g:' prefix.
1222 skip -gfile file-glob-pattern
1223 skip -function function
1224 skip -rfunction regular-expression
1225 A generalized form of the skip command, with new support for
1226 glob-style file names and regular expressions for function names.
1227 Additionally, a file spec and a function spec may now be combined.
1229 maint info line-table REGEXP
1230 Display the contents of GDB's internal line table data struture.
1233 Run any GDB unit tests that were compiled in.
1236 Start a new user interface instance running INTERP as interpreter,
1237 using the TTY file for input/output.
1241 ** gdb.Breakpoint objects have a new attribute "pending", which
1242 indicates whether the breakpoint is pending.
1243 ** Three new breakpoint-related events have been added:
1244 gdb.breakpoint_created, gdb.breakpoint_modified, and
1245 gdb.breakpoint_deleted.
1247 signal-event EVENTID
1248 Signal ("set") the given MS-Windows event object. This is used in
1249 conjunction with the Windows JIT debugging (AeDebug) support, where
1250 the OS suspends a crashing process until a debugger can attach to
1251 it. Resuming the crashing process, in order to debug it, is done by
1252 signalling an event.
1254 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1255 was added in GDBserver, including JIT compiling fast tracepoint's
1256 conditional expression bytecode into native code.
1258 * Support for various remote target protocols and ROM monitors has
1261 target m32rsdi Remote M32R debugging over SDI
1262 target mips MIPS remote debugging protocol
1263 target pmon PMON ROM monitor
1264 target ddb NEC's DDB variant of PMON for Vr4300
1265 target rockhopper NEC RockHopper variant of PMON
1266 target lsi LSI variant of PMO
1268 * Support for tracepoints and fast tracepoints on powerpc-linux,
1269 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1270 including JIT compiling fast tracepoint's conditional expression
1271 bytecode into native code.
1273 * MI async record =record-started now includes the method and format used for
1274 recording. For example:
1276 =record-started,thread-group="i1",method="btrace",format="bts"
1278 * MI async record =thread-selected now includes the frame field. For example:
1280 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1284 Andes NDS32 nds32*-*-elf
1286 *** Changes in GDB 7.11
1288 * GDB now supports debugging kernel-based threads on FreeBSD.
1290 * Per-inferior thread numbers
1292 Thread numbers are now per inferior instead of global. If you're
1293 debugging multiple inferiors, GDB displays thread IDs using a
1294 qualified INF_NUM.THR_NUM form. For example:
1298 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1299 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1300 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1301 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1303 As consequence, thread numbers as visible in the $_thread
1304 convenience variable and in Python's InferiorThread.num attribute
1305 are no longer unique between inferiors.
1307 GDB now maintains a second thread ID per thread, referred to as the
1308 global thread ID, which is the new equivalent of thread numbers in
1309 previous releases. See also $_gthread below.
1311 For backwards compatibility, MI's thread IDs always refer to global
1314 * Commands that accept thread IDs now accept the qualified
1315 INF_NUM.THR_NUM form as well. For example:
1318 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1321 * In commands that accept a list of thread IDs, you can now refer to
1322 all threads of an inferior using a star wildcard. GDB accepts
1323 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1324 refer to all threads of the current inferior. For example, "info
1327 * You can use "info threads -gid" to display the global thread ID of
1330 * The new convenience variable $_gthread holds the global number of
1333 * The new convenience variable $_inferior holds the number of the
1336 * GDB now displays the ID and name of the thread that hit a breakpoint
1337 or received a signal, if your program is multi-threaded. For
1340 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1341 Thread 1 "main" received signal SIGINT, Interrupt.
1343 * Record btrace now supports non-stop mode.
1345 * Support for tracepoints on aarch64-linux was added in GDBserver.
1347 * The 'record instruction-history' command now indicates speculative execution
1348 when using the Intel Processor Trace recording format.
1350 * GDB now allows users to specify explicit locations, bypassing
1351 the linespec parser. This feature is also available to GDB/MI
1354 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1355 GDB now is able to debug both AArch64 applications and ARM applications
1358 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1359 including JIT compiling fast tracepoint's conditional expression bytecode
1362 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1364 * "info threads", "info inferiors", "info display", "info checkpoints"
1365 and "maint info program-spaces" now list the corresponding items in
1366 ascending ID order, for consistency with all other "info" commands.
1368 * In Ada, the overloads selection menu has been enhanced to display the
1369 parameter types and the return types for the matching overloaded subprograms.
1373 maint set target-non-stop (on|off|auto)
1374 maint show target-non-stop
1375 Control whether GDB targets always operate in non-stop mode even if
1376 "set non-stop" is "off". The default is "auto", meaning non-stop
1377 mode is enabled if supported by the target.
1379 maint set bfd-sharing
1380 maint show bfd-sharing
1381 Control the reuse of bfd objects.
1384 show debug bfd-cache
1385 Control display of debugging info regarding bfd caching.
1389 Control display of debugging info regarding FreeBSD threads.
1391 set remote multiprocess-extensions-packet
1392 show remote multiprocess-extensions-packet
1393 Set/show the use of the remote protocol multiprocess extensions.
1395 set remote thread-events
1396 show remote thread-events
1397 Set/show the use of thread create/exit events.
1399 set ada print-signatures on|off
1400 show ada print-signatures"
1401 Control whether parameter types and return types are displayed in overloads
1402 selection menus. It is activaled (@code{on}) by default.
1406 Controls the maximum size of memory, in bytes, that GDB will
1407 allocate for value contents. Prevents incorrect programs from
1408 causing GDB to allocate overly large buffers. Default is 64k.
1410 * The "disassemble" command accepts a new modifier: /s.
1411 It prints mixed source+disassembly like /m with two differences:
1412 - disassembled instructions are now printed in program order, and
1413 - and source for all relevant files is now printed.
1414 The "/m" option is now considered deprecated: its "source-centric"
1415 output hasn't proved useful in practice.
1417 * The "record instruction-history" command accepts a new modifier: /s.
1418 It behaves exactly like /m and prints mixed source+disassembly.
1420 * The "set scheduler-locking" command supports a new mode "replay".
1421 It behaves like "off" in record mode and like "on" in replay mode.
1423 * Support for various ROM monitors has been removed:
1425 target dbug dBUG ROM monitor for Motorola ColdFire
1426 target picobug Motorola picobug monitor
1427 target dink32 DINK32 ROM monitor for PowerPC
1428 target m32r Renesas M32R/D ROM monitor
1429 target mon2000 mon2000 ROM monitor
1430 target ppcbug PPCBUG ROM monitor for PowerPC
1432 * Support for reading/writing memory and extracting values on architectures
1433 whose memory is addressable in units of any integral multiple of 8 bits.
1436 Allows to break when an Ada exception is handled.
1438 * New remote packets
1441 Indicates that an exec system call was executed.
1443 exec-events feature in qSupported
1444 The qSupported packet allows GDB to request support for exec
1445 events using the new 'gdbfeature' exec-event, and the qSupported
1446 response can contain the corresponding 'stubfeature'. Set and
1447 show commands can be used to display whether these features are enabled.
1450 Equivalent to interrupting with the ^C character, but works in
1453 thread created stop reason (T05 create:...)
1454 Indicates that the thread was just created and is stopped at entry.
1456 thread exit stop reply (w exitcode;tid)
1457 Indicates that the thread has terminated.
1460 Enables/disables thread create and exit event reporting. For
1461 example, this is used in non-stop mode when GDB stops a set of
1462 threads and synchronously waits for the their corresponding stop
1463 replies. Without exit events, if one of the threads exits, GDB
1464 would hang forever not knowing that it should no longer expect a
1465 stop for that same thread.
1468 Indicates that there are no resumed threads left in the target (all
1469 threads are stopped). The remote stub reports support for this stop
1470 reply to GDB's qSupported query.
1473 Enables/disables catching syscalls from the inferior process.
1474 The remote stub reports support for this packet to GDB's qSupported query.
1476 syscall_entry stop reason
1477 Indicates that a syscall was just called.
1479 syscall_return stop reason
1480 Indicates that a syscall just returned.
1482 * Extended-remote exec events
1484 ** GDB now has support for exec events on extended-remote Linux targets.
1485 For such targets with Linux kernels 2.5.46 and later, this enables
1486 follow-exec-mode and exec catchpoints.
1488 set remote exec-event-feature-packet
1489 show remote exec-event-feature-packet
1490 Set/show the use of the remote exec event feature.
1492 * Thread names in remote protocol
1494 The reply to qXfer:threads:read may now include a name attribute for each
1497 * Target remote mode fork and exec events
1499 ** GDB now has support for fork and exec events on target remote mode
1500 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1501 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1502 fork and exec catchpoints.
1504 * Remote syscall events
1506 ** GDB now has support for catch syscall on remote Linux targets,
1507 currently enabled on x86/x86_64 architectures.
1509 set remote catch-syscall-packet
1510 show remote catch-syscall-packet
1511 Set/show the use of the remote catch syscall feature.
1515 ** The -var-set-format command now accepts the zero-hexadecimal
1516 format. It outputs data in hexadecimal format with zero-padding on the
1521 ** gdb.InferiorThread objects have a new attribute "global_num",
1522 which refers to the thread's global thread ID. The existing
1523 "num" attribute now refers to the thread's per-inferior number.
1524 See "Per-inferior thread numbers" above.
1525 ** gdb.InferiorThread objects have a new attribute "inferior", which
1526 is the Inferior object the thread belongs to.
1528 *** Changes in GDB 7.10
1530 * Support for process record-replay and reverse debugging on aarch64*-linux*
1531 targets has been added. GDB now supports recording of A64 instruction set
1532 including advance SIMD instructions.
1534 * Support for Sun's version of the "stabs" debug file format has been removed.
1536 * GDB now honors the content of the file /proc/PID/coredump_filter
1537 (PID is the process ID) on GNU/Linux systems. This file can be used
1538 to specify the types of memory mappings that will be included in a
1539 corefile. For more information, please refer to the manual page of
1540 "core(5)". GDB also has a new command: "set use-coredump-filter
1541 on|off". It allows to set whether GDB will read the content of the
1542 /proc/PID/coredump_filter file when generating a corefile.
1544 * The "info os" command on GNU/Linux can now display information on
1546 "info os cpus" Listing of all cpus/cores on the system
1548 * GDB has two new commands: "set serial parity odd|even|none" and
1549 "show serial parity". These allows to set or show parity for the
1552 * The "info source" command now displays the producer string if it was
1553 present in the debug info. This typically includes the compiler version
1554 and may include things like its command line arguments.
1556 * The "info dll", an alias of the "info sharedlibrary" command,
1557 is now available on all platforms.
1559 * Directory names supplied to the "set sysroot" commands may be
1560 prefixed with "target:" to tell GDB to access shared libraries from
1561 the target system, be it local or remote. This replaces the prefix
1562 "remote:". The default sysroot has been changed from "" to
1563 "target:". "remote:" is automatically converted to "target:" for
1564 backward compatibility.
1566 * The system root specified by "set sysroot" will be prepended to the
1567 filename of the main executable (if reported to GDB as absolute by
1568 the operating system) when starting processes remotely, and when
1569 attaching to already-running local or remote processes.
1571 * GDB now supports automatic location and retrieval of executable
1572 files from remote targets. Remote debugging can now be initiated
1573 using only a "target remote" or "target extended-remote" command
1574 (no "set sysroot" or "file" commands are required). See "New remote
1577 * The "dump" command now supports verilog hex format.
1579 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1581 * On GNU/Linux, GDB and gdbserver are now able to access executable
1582 and shared library files without a "set sysroot" command when
1583 attaching to processes running in different mount namespaces from
1584 the debugger. This makes it possible to attach to processes in
1585 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1586 See "New remote packets" below.
1588 * The "tui reg" command now provides completion for all of the
1589 available register groups, including target specific groups.
1591 * The HISTSIZE environment variable is no longer read when determining
1592 the size of GDB's command history. GDB now instead reads the dedicated
1593 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1594 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1599 ** Memory ports can now be unbuffered.
1603 ** gdb.Objfile objects have a new attribute "username",
1604 which is the name of the objfile as specified by the user,
1605 without, for example, resolving symlinks.
1606 ** You can now write frame unwinders in Python.
1607 ** gdb.Type objects have a new method "optimized_out",
1608 returning optimized out gdb.Value instance of this type.
1609 ** gdb.Value objects have new methods "reference_value" and
1610 "const_value" which return a reference to the value and a
1611 "const" version of the value respectively.
1615 maint print symbol-cache
1616 Print the contents of the symbol cache.
1618 maint print symbol-cache-statistics
1619 Print statistics of symbol cache usage.
1621 maint flush-symbol-cache
1622 Flush the contents of the symbol cache.
1626 Start branch trace recording using Branch Trace Store (BTS) format.
1629 Evaluate expression by using the compiler and print result.
1633 Explicit commands for enabling and disabling tui mode.
1636 set mpx bound on i386 and amd64
1637 Support for bound table investigation on Intel MPX enabled applications.
1641 Start branch trace recording using Intel Processor Trace format.
1644 Print information about branch tracing internals.
1646 maint btrace packet-history
1647 Print the raw branch tracing data.
1649 maint btrace clear-packet-history
1650 Discard the stored raw branch tracing data.
1653 Discard all branch tracing data. It will be fetched and processed
1654 anew by the next "record" command.
1659 Renamed from "set debug dwarf2-die".
1660 show debug dwarf-die
1661 Renamed from "show debug dwarf2-die".
1663 set debug dwarf-read
1664 Renamed from "set debug dwarf2-read".
1665 show debug dwarf-read
1666 Renamed from "show debug dwarf2-read".
1668 maint set dwarf always-disassemble
1669 Renamed from "maint set dwarf2 always-disassemble".
1670 maint show dwarf always-disassemble
1671 Renamed from "maint show dwarf2 always-disassemble".
1673 maint set dwarf max-cache-age
1674 Renamed from "maint set dwarf2 max-cache-age".
1675 maint show dwarf max-cache-age
1676 Renamed from "maint show dwarf2 max-cache-age".
1678 set debug dwarf-line
1679 show debug dwarf-line
1680 Control display of debugging info regarding DWARF line processing.
1683 show max-completions
1684 Set the maximum number of candidates to be considered during
1685 completion. The default value is 200. This limit allows GDB
1686 to avoid generating large completion lists, the computation of
1687 which can cause the debugger to become temporarily unresponsive.
1689 set history remove-duplicates
1690 show history remove-duplicates
1691 Control the removal of duplicate history entries.
1693 maint set symbol-cache-size
1694 maint show symbol-cache-size
1695 Control the size of the symbol cache.
1697 set|show record btrace bts buffer-size
1698 Set and show the size of the ring buffer used for branch tracing in
1700 The obtained size may differ from the requested size. Use "info
1701 record" to see the obtained buffer size.
1703 set debug linux-namespaces
1704 show debug linux-namespaces
1705 Control display of debugging info regarding Linux namespaces.
1707 set|show record btrace pt buffer-size
1708 Set and show the size of the ring buffer used for branch tracing in
1709 Intel Processor Trace format.
1710 The obtained size may differ from the requested size. Use "info
1711 record" to see the obtained buffer size.
1713 maint set|show btrace pt skip-pad
1714 Set and show whether PAD packets are skipped when computing the
1717 * The command 'thread apply all' can now support new option '-ascending'
1718 to call its specified command for all threads in ascending order.
1720 * Python/Guile scripting
1722 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1723 special section named `.debug_gdb_scripts'.
1725 * New remote packets
1727 qXfer:btrace-conf:read
1728 Return the branch trace configuration for the current thread.
1730 Qbtrace-conf:bts:size
1731 Set the requested ring buffer size for branch tracing in BTS format.
1734 Enable Intel Procesor Trace-based branch tracing for the current
1735 process. The remote stub reports support for this packet to GDB's
1738 Qbtrace-conf:pt:size
1739 Set the requested ring buffer size for branch tracing in Intel Processor
1743 Indicates a memory breakpoint instruction was executed, irrespective
1744 of whether it was GDB that planted the breakpoint or the breakpoint
1745 is hardcoded in the program. This is required for correct non-stop
1749 Indicates the target stopped for a hardware breakpoint. This is
1750 required for correct non-stop mode operation.
1753 Return information about files on the remote system.
1755 qXfer:exec-file:read
1756 Return the full absolute name of the file that was executed to
1757 create a process running on the remote system.
1760 Select the filesystem on which vFile: operations with filename
1761 arguments will operate. This is required for GDB to be able to
1762 access files on remote targets where the remote stub does not
1763 share a common filesystem with the inferior(s).
1766 Indicates that a fork system call was executed.
1769 Indicates that a vfork system call was executed.
1771 vforkdone stop reason
1772 Indicates that a vfork child of the specified process has executed
1773 an exec or exit, allowing the vfork parent to resume execution.
1775 fork-events and vfork-events features in qSupported
1776 The qSupported packet allows GDB to request support for fork and
1777 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1778 and the qSupported response can contain the corresponding
1779 'stubfeatures'. Set and show commands can be used to display
1780 whether these features are enabled.
1782 * Extended-remote fork events
1784 ** GDB now has support for fork events on extended-remote Linux
1785 targets. For targets with Linux kernels 2.5.60 and later, this
1786 enables follow-fork-mode and detach-on-fork for both fork and
1787 vfork, as well as fork and vfork catchpoints.
1789 * The info record command now shows the recording format and the
1790 branch tracing configuration for the current thread when using
1791 the btrace record target.
1792 For the BTS format, it shows the ring buffer size.
1794 * GDB now has support for DTrace USDT (Userland Static Defined
1795 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1797 * GDB now supports access to vector registers on S/390 GNU/Linux
1800 * Removed command line options
1802 -xdb HP-UX XDB compatibility mode.
1804 * Removed targets and native configurations
1806 HP/PA running HP-UX hppa*-*-hpux*
1807 Itanium running HP-UX ia64-*-hpux*
1809 * New configure options
1812 This configure option allows the user to build GDB with support for
1813 Intel Processor Trace (default: auto). This requires libipt.
1815 --with-libipt-prefix=PATH
1816 Specify the path to the version of libipt that GDB should use.
1817 $PATH/include should contain the intel-pt.h header and
1818 $PATH/lib should contain the libipt.so library.
1820 *** Changes in GDB 7.9.1
1824 ** Xmethods can now specify a result type.
1826 *** Changes in GDB 7.9
1828 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1832 ** You can now access frame registers from Python scripts.
1833 ** New attribute 'producer' for gdb.Symtab objects.
1834 ** gdb.Objfile objects have a new attribute "progspace",
1835 which is the gdb.Progspace object of the containing program space.
1836 ** gdb.Objfile objects have a new attribute "owner".
1837 ** gdb.Objfile objects have a new attribute "build_id",
1838 which is the build ID generated when the file was built.
1839 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1840 ** A new event "gdb.clear_objfiles" has been added, triggered when
1841 selecting a new file to debug.
1842 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1843 ** New function gdb.lookup_objfile.
1845 New events which are triggered when GDB modifies the state of the
1848 ** gdb.events.inferior_call_pre: Function call is about to be made.
1849 ** gdb.events.inferior_call_post: Function call has just been made.
1850 ** gdb.events.memory_changed: A memory location has been altered.
1851 ** gdb.events.register_changed: A register has been altered.
1853 * New Python-based convenience functions:
1855 ** $_caller_is(name [, number_of_frames])
1856 ** $_caller_matches(regexp [, number_of_frames])
1857 ** $_any_caller_is(name [, number_of_frames])
1858 ** $_any_caller_matches(regexp [, number_of_frames])
1860 * GDB now supports the compilation and injection of source code into
1861 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1862 to compile the source code to object code, and if successful, inject
1863 and execute that code within the current context of the inferior.
1864 Currently the C language is supported. The commands used to
1865 interface with this new feature are:
1867 compile code [-raw|-r] [--] [source code]
1868 compile file [-raw|-r] filename
1872 demangle [-l language] [--] name
1873 Demangle "name" in the specified language, or the current language
1874 if elided. This command is renamed from the "maint demangle" command.
1875 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1876 as "maint demangler-warning".
1878 queue-signal signal-name-or-number
1879 Queue a signal to be delivered to the thread when it is resumed.
1881 add-auto-load-scripts-directory directory
1882 Add entries to the list of directories from which to load auto-loaded
1885 maint print user-registers
1886 List all currently available "user" registers.
1888 compile code [-r|-raw] [--] [source code]
1889 Compile, inject, and execute in the inferior the executable object
1890 code produced by compiling the provided source code.
1892 compile file [-r|-raw] filename
1893 Compile and inject into the inferior the executable object code
1894 produced by compiling the source code stored in the filename
1897 * On resume, GDB now always passes the signal the program had stopped
1898 for to the thread the signal was sent to, even if the user changed
1899 threads before resuming. Previously GDB would often (but not
1900 always) deliver the signal to the thread that happens to be current
1903 * Conversely, the "signal" command now consistently delivers the
1904 requested signal to the current thread. GDB now asks for
1905 confirmation if the program had stopped for a signal and the user
1906 switched threads meanwhile.
1908 * "breakpoint always-inserted" modes "off" and "auto" merged.
1910 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1911 won't remove breakpoints from the target until all threads stop,
1912 even in non-stop mode. The "auto" mode has been removed, and "off"
1913 is now the default mode.
1917 set debug symbol-lookup
1918 show debug symbol-lookup
1919 Control display of debugging info regarding symbol lookup.
1923 ** The -list-thread-groups command outputs an exit-code field for
1924 inferiors that have exited.
1928 MIPS SDE mips*-sde*-elf*
1932 Support for these obsolete configurations has been removed.
1934 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1935 SGI Irix-5.x mips-*-irix5*
1936 SGI Irix-6.x mips-*-irix6*
1937 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1938 VAX running Ultrix vax-*-ultrix*
1940 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1941 and "assf"), have been removed. Use the "sharedlibrary" command, or
1942 its alias "share", instead.
1944 *** Changes in GDB 7.8
1946 * New command line options
1949 This is an alias for the --data-directory option.
1951 * GDB supports printing and modifying of variable length automatic arrays
1952 as specified in ISO C99.
1954 * The ARM simulator now supports instruction level tracing
1955 with or without disassembly.
1959 GDB now has support for scripting using Guile. Whether this is
1960 available is determined at configure time.
1961 Guile version 2.0 or greater is required.
1962 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1964 * New commands (for set/show, see "New options" below)
1968 Invoke CODE by passing it to the Guile interpreter.
1972 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1974 info auto-load guile-scripts [regexp]
1975 Print the list of automatically loaded Guile scripts.
1977 * The source command is now capable of sourcing Guile scripts.
1978 This feature is dependent on the debugger being built with Guile support.
1982 set print symbol-loading (off|brief|full)
1983 show print symbol-loading
1984 Control whether to print informational messages when loading symbol
1985 information for a file. The default is "full", but when debugging
1986 programs with large numbers of shared libraries the amount of output
1987 becomes less useful.
1989 set guile print-stack (none|message|full)
1990 show guile print-stack
1991 Show a stack trace when an error is encountered in a Guile script.
1993 set auto-load guile-scripts (on|off)
1994 show auto-load guile-scripts
1995 Control auto-loading of Guile script files.
1997 maint ada set ignore-descriptive-types (on|off)
1998 maint ada show ignore-descriptive-types
1999 Control whether the debugger should ignore descriptive types in Ada
2000 programs. The default is not to ignore the descriptive types. See
2001 the user manual for more details on descriptive types and the intended
2002 usage of this option.
2004 set auto-connect-native-target
2006 Control whether GDB is allowed to automatically connect to the
2007 native target for the run, attach, etc. commands when not connected
2008 to any target yet. See also "target native" below.
2010 set record btrace replay-memory-access (read-only|read-write)
2011 show record btrace replay-memory-access
2012 Control what memory accesses are allowed during replay.
2014 maint set target-async (on|off)
2015 maint show target-async
2016 This controls whether GDB targets operate in synchronous or
2017 asynchronous mode. Normally the default is asynchronous, if it is
2018 available; but this can be changed to more easily debug problems
2019 occurring only in synchronous mode.
2021 set mi-async (on|off)
2023 Control whether MI asynchronous mode is preferred. This supersedes
2024 "set target-async" of previous GDB versions.
2026 * "set target-async" is deprecated as a CLI option and is now an alias
2027 for "set mi-async" (only puts MI into async mode).
2029 * Background execution commands (e.g., "c&", "s&", etc.) are now
2030 possible ``out of the box'' if the target supports them. Previously
2031 the user would need to explicitly enable the possibility with the
2032 "set target-async on" command.
2034 * New features in the GDB remote stub, GDBserver
2036 ** New option --debug-format=option1[,option2,...] allows one to add
2037 additional text to each output. At present only timestamps
2038 are supported: --debug-format=timestamps.
2039 Timestamps can also be turned on with the
2040 "monitor set debug-format timestamps" command from GDB.
2042 * The 'record instruction-history' command now starts counting instructions
2043 at one. This also affects the instruction ranges reported by the
2044 'record function-call-history' command when given the /i modifier.
2046 * The command 'record function-call-history' supports a new modifier '/c' to
2047 indent the function names based on their call stack depth.
2048 The fields for the '/i' and '/l' modifier have been reordered.
2049 The source line range is now prefixed with 'at'.
2050 The instruction range is now prefixed with 'inst'.
2051 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2052 "record instruction-history" and "list" commands.
2054 * The ranges given as arguments to the 'record function-call-history' and
2055 'record instruction-history' commands are now inclusive.
2057 * The btrace record target now supports the 'record goto' command.
2058 For locations inside the execution trace, the back trace is computed
2059 based on the information stored in the execution trace.
2061 * The btrace record target supports limited reverse execution and replay.
2062 The target does not record data and therefore does not allow reading
2063 memory or registers.
2065 * The "catch syscall" command now works on s390*-linux* targets.
2067 * The "compare-sections" command is no longer specific to target
2068 remote. It now works with all targets.
2070 * All native targets are now consistently called "native".
2071 Consequently, the "target child", "target GNU", "target djgpp",
2072 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2073 commands have been replaced with "target native". The QNX/NTO port
2074 leaves the "procfs" target in place and adds a "native" target for
2075 consistency with other ports. The impact on users should be minimal
2076 as these commands previously either throwed an error, or were
2077 no-ops. The target's name is visible in the output of the following
2078 commands: "help target", "info target", "info files", "maint print
2081 * The "target native" command now connects to the native target. This
2082 can be used to launch native programs even when "set
2083 auto-connect-native-target" is set to off.
2085 * GDB now supports access to Intel MPX registers on GNU/Linux.
2087 * Support for Intel AVX-512 registers on GNU/Linux.
2088 Support displaying and modifying Intel AVX-512 registers
2089 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2091 * New remote packets
2093 qXfer:btrace:read's annex
2094 The qXfer:btrace:read packet supports a new annex 'delta' to read
2095 branch trace incrementally.
2099 ** Valid Python operations on gdb.Value objects representing
2100 structs/classes invoke the corresponding overloaded operators if
2102 ** New `Xmethods' feature in the Python API. Xmethods are
2103 additional methods or replacements for existing methods of a C++
2104 class. This feature is useful for those cases where a method
2105 defined in C++ source code could be inlined or optimized out by
2106 the compiler, making it unavailable to GDB.
2109 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2111 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2112 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2113 its alias "share", instead.
2115 * The commands "set remotebaud" and "show remotebaud" are no longer
2116 supported. Use "set serial baud" and "show serial baud" (respectively)
2121 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2122 target-async". The latter is left as a deprecated alias of the
2123 former for backward compatibility. If the target supports it,
2124 CLI background execution commands are now always possible by
2125 default, independently of whether the frontend stated a
2126 preference for asynchronous execution with "-gdb-set mi-async".
2127 Previously "-gdb-set target-async off" affected both MI execution
2128 commands and CLI execution commands.
2130 *** Changes in GDB 7.7
2132 * Improved support for process record-replay and reverse debugging on
2133 arm*-linux* targets. Support for thumb32 and syscall instruction
2134 recording has been added.
2136 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2138 * GDB now supports Fission DWP file format version 2.
2139 http://gcc.gnu.org/wiki/DebugFission
2141 * New convenience function "$_isvoid", to check whether an expression
2142 is void. A void expression is an expression where the type of the
2143 result is "void". For example, some convenience variables may be
2144 "void" when evaluated (e.g., "$_exitcode" before the execution of
2145 the program being debugged; or an undefined convenience variable).
2146 Another example, when calling a function whose return type is
2149 * The "maintenance print objfiles" command now takes an optional regexp.
2151 * The "catch syscall" command now works on arm*-linux* targets.
2153 * GDB now consistently shows "<not saved>" when printing values of
2154 registers the debug info indicates have not been saved in the frame
2155 and there's nowhere to retrieve them from
2156 (callee-saved/call-clobbered registers):
2161 (gdb) info registers rax
2164 Before, the former would print "<optimized out>", and the latter
2165 "*value not available*".
2167 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2172 ** Frame filters and frame decorators have been added.
2173 ** Temporary breakpoints are now supported.
2174 ** Line tables representation has been added.
2175 ** New attribute 'parent_type' for gdb.Field objects.
2176 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2177 ** New attribute 'name' for gdb.Type objects.
2181 Nios II ELF nios2*-*-elf
2182 Nios II GNU/Linux nios2*-*-linux
2183 Texas Instruments MSP430 msp430*-*-elf
2185 * Removed native configurations
2187 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2188 been removed. ELF variants of these configurations are kept supported.
2190 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2191 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2192 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2193 i[34567]86-*-openbsd3.[0-3]
2194 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2195 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2196 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2200 Like "catch throw", but catches a re-thrown exception.
2201 maint check-psymtabs
2202 Renamed from old "maint check-symtabs".
2204 Perform consistency checks on symtabs.
2205 maint expand-symtabs
2206 Expand symtabs matching an optional regexp.
2209 Display the details of GDB configure-time options.
2211 maint set|show per-command
2212 maint set|show per-command space
2213 maint set|show per-command time
2214 maint set|show per-command symtab
2215 Enable display of per-command gdb resource usage.
2217 remove-symbol-file FILENAME
2218 remove-symbol-file -a ADDRESS
2219 Remove a symbol file added via add-symbol-file. The file to remove
2220 can be identified by its filename or by an address that lies within
2221 the boundaries of this symbol file in memory.
2224 info exceptions REGEXP
2225 Display the list of Ada exceptions defined in the program being
2226 debugged. If provided, only the exceptions whose names match REGEXP
2231 set debug symfile off|on
2233 Control display of debugging info regarding reading symbol files and
2234 symbol tables within those files
2236 set print raw frame-arguments
2237 show print raw frame-arguments
2238 Set/show whether to print frame arguments in raw mode,
2239 disregarding any defined pretty-printers.
2241 set remote trace-status-packet
2242 show remote trace-status-packet
2243 Set/show the use of remote protocol qTStatus packet.
2247 Control display of debugging messages related to Nios II targets.
2251 Control whether target-assisted range stepping is enabled.
2253 set startup-with-shell
2254 show startup-with-shell
2255 Specifies whether Unix child processes are started via a shell or
2260 Use the target memory cache for accesses to the code segment. This
2261 improves performance of remote debugging (particularly disassembly).
2263 * You can now use a literal value 'unlimited' for options that
2264 interpret 0 or -1 as meaning "unlimited". E.g., "set
2265 trace-buffer-size unlimited" is now an alias for "set
2266 trace-buffer-size -1" and "set height unlimited" is now an alias for
2269 * The "set debug symtab-create" debugging option of GDB has been changed to
2270 accept a verbosity level. 0 means "off", 1 provides basic debugging
2271 output, and values of 2 or greater provides more verbose output.
2273 * New command-line options
2275 Display the details of GDB configure-time options.
2277 * The command 'tsave' can now support new option '-ctf' to save trace
2278 buffer in Common Trace Format.
2280 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2283 * GDB now implements the the C++ 'typeid' operator.
2285 * The new convenience variable $_exception holds the exception being
2286 thrown or caught at an exception-related catchpoint.
2288 * The exception-related catchpoints, like "catch throw", now accept a
2289 regular expression which can be used to filter exceptions by type.
2291 * The new convenience variable $_exitsignal is automatically set to
2292 the terminating signal number when the program being debugged dies
2293 due to an uncaught signal.
2297 ** All MI commands now accept an optional "--language" option.
2298 Support for this feature can be verified by using the "-list-features"
2299 command, which should contain "language-option".
2301 ** The new command -info-gdb-mi-command allows the user to determine
2302 whether a GDB/MI command is supported or not.
2304 ** The "^error" result record returned when trying to execute an undefined
2305 GDB/MI command now provides a variable named "code" whose content is the
2306 "undefined-command" error code. Support for this feature can be verified
2307 by using the "-list-features" command, which should contain
2308 "undefined-command-error-code".
2310 ** The -trace-save MI command can optionally save trace buffer in Common
2313 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2315 ** The command -data-list-register-values now accepts an optional
2316 "--skip-unavailable" option. When used, only the available registers
2319 ** The new command -trace-frame-collected dumps collected variables,
2320 computed expressions, tvars, memory and registers in a traceframe.
2322 ** The commands -stack-list-locals, -stack-list-arguments and
2323 -stack-list-variables now accept an option "--skip-unavailable".
2324 When used, only the available locals or arguments are displayed.
2326 ** The -exec-run command now accepts an optional "--start" option.
2327 When used, the command follows the same semantics as the "start"
2328 command, stopping the program's execution at the start of its
2329 main subprogram. Support for this feature can be verified using
2330 the "-list-features" command, which should contain
2331 "exec-run-start-option".
2333 ** The new commands -catch-assert and -catch-exceptions insert
2334 catchpoints stopping the program when Ada exceptions are raised.
2336 ** The new command -info-ada-exceptions provides the equivalent of
2337 the new "info exceptions" command.
2339 * New system-wide configuration scripts
2340 A GDB installation now provides scripts suitable for use as system-wide
2341 configuration scripts for the following systems:
2345 * GDB now supports target-assigned range stepping with remote targets.
2346 This improves the performance of stepping source lines by reducing
2347 the number of control packets from/to GDB. See "New remote packets"
2350 * GDB now understands the element 'tvar' in the XML traceframe info.
2351 It has the id of the collected trace state variables.
2353 * On S/390 targets that provide the transactional-execution feature,
2354 the program interruption transaction diagnostic block (TDB) is now
2355 represented as a number of additional "registers" in GDB.
2357 * New remote packets
2361 The vCont packet supports a new 'r' action, that tells the remote
2362 stub to step through an address range itself, without GDB
2363 involvemement at each single-step.
2365 qXfer:libraries-svr4:read's annex
2366 The previously unused annex of the qXfer:libraries-svr4:read packet
2367 is now used to support passing an argument list. The remote stub
2368 reports support for this argument list to GDB's qSupported query.
2369 The defined arguments are "start" and "prev", used to reduce work
2370 necessary for library list updating, resulting in significant
2373 * New features in the GDB remote stub, GDBserver
2375 ** GDBserver now supports target-assisted range stepping. Currently
2376 enabled on x86/x86_64 GNU/Linux targets.
2378 ** GDBserver now adds element 'tvar' in the XML in the reply to
2379 'qXfer:traceframe-info:read'. It has the id of the collected
2380 trace state variables.
2382 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2385 * New 'z' formatter for printing and examining memory, this displays the
2386 value as hexadecimal zero padded on the left to the size of the type.
2388 * GDB can now use Windows x64 unwinding data.
2390 * The "set remotebaud" command has been replaced by "set serial baud".
2391 Similarly, "show remotebaud" has been replaced by "show serial baud".
2392 The "set remotebaud" and "show remotebaud" commands are still available
2393 to provide backward compatibility with older versions of GDB.
2395 *** Changes in GDB 7.6
2397 * Target record has been renamed to record-full.
2398 Record/replay is now enabled with the "record full" command.
2399 This also affects settings that are associated with full record/replay
2400 that have been moved from "set/show record" to "set/show record full":
2402 set|show record full insn-number-max
2403 set|show record full stop-at-limit
2404 set|show record full memory-query
2406 * A new record target "record-btrace" has been added. The new target
2407 uses hardware support to record the control-flow of a process. It
2408 does not support replaying the execution, but it implements the
2409 below new commands for investigating the recorded execution log.
2410 This new recording method can be enabled using:
2414 The "record-btrace" target is only available on Intel Atom processors
2415 and requires a Linux kernel 2.6.32 or later.
2417 * Two new commands have been added for record/replay to give information
2418 about the recorded execution without having to replay the execution.
2419 The commands are only supported by "record btrace".
2421 record instruction-history prints the execution history at
2422 instruction granularity
2424 record function-call-history prints the execution history at
2425 function granularity
2427 * New native configurations
2429 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2430 FreeBSD/powerpc powerpc*-*-freebsd
2431 x86_64/Cygwin x86_64-*-cygwin*
2432 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2436 ARM AArch64 aarch64*-*-elf
2437 ARM AArch64 GNU/Linux aarch64*-*-linux
2438 Lynx 178 PowerPC powerpc-*-lynx*178
2439 x86_64/Cygwin x86_64-*-cygwin*
2440 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2442 * If the configured location of system.gdbinit file (as given by the
2443 --with-system-gdbinit option at configure time) is in the
2444 data-directory (as specified by --with-gdb-datadir at configure
2445 time) or in one of its subdirectories, then GDB will look for the
2446 system-wide init file in the directory specified by the
2447 --data-directory command-line option.
2449 * New command line options:
2451 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2452 other initialization files, unlike -nx which disables all of them.
2454 * Removed command line options
2456 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2459 * The 'ptype' and 'whatis' commands now accept an argument to control
2462 * 'info proc' now works on some core files.
2466 ** Vectors can be created with gdb.Type.vector.
2468 ** Python's atexit.register now works in GDB.
2470 ** Types can be pretty-printed via a Python API.
2472 ** Python 3 is now supported (in addition to Python 2.4 or later)
2474 ** New class gdb.Architecture exposes GDB's internal representation
2475 of architecture in the Python API.
2477 ** New method Frame.architecture returns the gdb.Architecture object
2478 corresponding to the frame's architecture.
2480 * New Python-based convenience functions:
2482 ** $_memeq(buf1, buf2, length)
2483 ** $_streq(str1, str2)
2485 ** $_regex(str, regex)
2487 * The 'cd' command now defaults to using '~' (the home directory) if not
2490 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2491 default for GCC since November 2000.
2493 * The command 'forward-search' can now be abbreviated as 'fo'.
2495 * The command 'info tracepoints' can now display 'installed on target'
2496 or 'not installed on target' for each non-pending location of tracepoint.
2498 * New configure options
2500 --enable-libmcheck/--disable-libmcheck
2501 By default, development versions are built with -lmcheck on hosts
2502 that support it, in order to help track memory corruption issues.
2503 Release versions, on the other hand, are built without -lmcheck
2504 by default. The --enable-libmcheck/--disable-libmcheck configure
2505 options allow the user to override that default.
2506 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2507 This configure option allows the user to build GDB with
2508 libbabeltrace using which GDB can read Common Trace Format data.
2510 * New commands (for set/show, see "New options" below)
2513 Catch signals. This is similar to "handle", but allows commands and
2514 conditions to be attached.
2517 List the BFDs known to GDB.
2519 python-interactive [command]
2521 Start a Python interactive prompt, or evaluate the optional command
2522 and print the result of expressions.
2525 "py" is a new alias for "python".
2527 enable type-printer [name]...
2528 disable type-printer [name]...
2529 Enable or disable type printers.
2533 ** For the Renesas Super-H architecture, the "regs" command has been removed
2534 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2539 set print type methods (on|off)
2540 show print type methods
2541 Control whether method declarations are displayed by "ptype".
2542 The default is to show them.
2544 set print type typedefs (on|off)
2545 show print type typedefs
2546 Control whether typedef definitions are displayed by "ptype".
2547 The default is to show them.
2549 set filename-display basename|relative|absolute
2550 show filename-display
2551 Control the way in which filenames is displayed.
2552 The default is "relative", which preserves previous behavior.
2554 set trace-buffer-size
2555 show trace-buffer-size
2556 Request target to change the size of trace buffer.
2558 set remote trace-buffer-size-packet auto|on|off
2559 show remote trace-buffer-size-packet
2560 Control the use of the remote protocol `QTBuffer:size' packet.
2564 Control display of debugging messages related to ARM AArch64.
2567 set debug coff-pe-read
2568 show debug coff-pe-read
2569 Control display of debugging messages related to reading of COFF/PE
2574 Control display of debugging messages related to Mach-O symbols
2577 set debug notification
2578 show debug notification
2579 Control display of debugging info for async remote notification.
2583 ** Command parameter changes are now notified using new async record
2584 "=cmd-param-changed".
2585 ** Trace frame changes caused by command "tfind" are now notified using
2586 new async record "=traceframe-changed".
2587 ** The creation, deletion and modification of trace state variables
2588 are now notified using new async records "=tsv-created",
2589 "=tsv-deleted" and "=tsv-modified".
2590 ** The start and stop of process record are now notified using new
2591 async record "=record-started" and "=record-stopped".
2592 ** Memory changes are now notified using new async record
2594 ** The data-disassemble command response will include a "fullname" field
2595 containing the absolute file name when source has been requested.
2596 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2597 command, to allow pattern filling of memory areas.
2598 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2599 library load/unload events.
2600 ** The response to breakpoint commands and breakpoint async records
2601 includes an "installed" field containing a boolean state about each
2602 non-pending tracepoint location is whether installed on target or not.
2603 ** Output of the "-trace-status" command includes a "trace-file" field
2604 containing the name of the trace file being examined. This field is
2605 optional, and only present when examining a trace file.
2606 ** The "fullname" field is now always present along with the "file" field,
2607 even if the file cannot be found by GDB.
2609 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2610 You must have the LZMA library available when configuring GDB for this
2611 feature to be enabled. For more information, see:
2612 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2614 * New remote packets
2617 Set the size of trace buffer. The remote stub reports support for this
2618 packet to gdb's qSupported query.
2621 Enable Branch Trace Store (BTS)-based branch tracing for the current
2622 thread. The remote stub reports support for this packet to gdb's
2626 Disable branch tracing for the current thread. The remote stub reports
2627 support for this packet to gdb's qSupported query.
2630 Read the traced branches for the current thread. The remote stub
2631 reports support for this packet to gdb's qSupported query.
2633 *** Changes in GDB 7.5
2635 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2636 for more x32 ABI info.
2638 * GDB now supports access to MIPS DSP registers on Linux targets.
2640 * GDB now supports debugging microMIPS binaries.
2642 * The "info os" command on GNU/Linux can now display information on
2643 several new classes of objects managed by the operating system:
2644 "info os procgroups" lists process groups
2645 "info os files" lists file descriptors
2646 "info os sockets" lists internet-domain sockets
2647 "info os shm" lists shared-memory regions
2648 "info os semaphores" lists semaphores
2649 "info os msg" lists message queues
2650 "info os modules" lists loaded kernel modules
2652 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2653 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2654 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2655 options and inspect the probe arguments using the new $_probe_arg family
2656 of convenience variables. You can obtain more information about SystemTap
2657 in <http://sourceware.org/systemtap/>.
2659 * GDB now supports reversible debugging on ARM, it allows you to
2660 debug basic ARM and THUMB instructions, and provides
2661 record/replay support.
2663 * The option "symbol-reloading" has been deleted as it is no longer used.
2667 ** GDB commands implemented in Python can now be put in command class
2670 ** The "maint set python print-stack on|off" is now deleted.
2672 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2673 apply "flag enum"-style pretty-printing to any enum.
2675 ** gdb.lookup_symbol can now work when there is no current frame.
2677 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2678 the source at which the symbol was defined.
2680 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2681 method 'value'. The former indicates whether the symbol needs a
2682 frame in order to compute its value, and the latter computes the
2685 ** A new method 'referenced_value' on gdb.Value objects which can
2686 dereference pointer as well as C++ reference values.
2688 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2689 which return the global and static blocks (as gdb.Block objects),
2690 of the underlying symbol table, respectively.
2692 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2693 object associated with a PC value.
2695 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2696 of the address range occupied by code for the current source line.
2698 * Go language support.
2699 GDB now supports debugging programs written in the Go programming
2702 * GDBserver now supports stdio connections.
2703 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2705 * The binary "gdbtui" can no longer be built or installed.
2706 Use "gdb -tui" instead.
2708 * GDB will now print "flag" enums specially. A flag enum is one where
2709 all the enumerator values have no bits in common when pairwise
2710 "and"ed. When printing a value whose type is a flag enum, GDB will
2711 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2712 (gdb) print (enum E) 3
2715 * The filename part of a linespec will now match trailing components
2716 of a source file name. For example, "break gcc/expr.c:1000" will
2717 now set a breakpoint in build/gcc/expr.c, but not
2718 build/libcpp/expr.c.
2720 * The "info proc" and "generate-core-file" commands will now also
2721 work on remote targets connected to GDBserver on Linux.
2723 * The command "info catch" has been removed. It has been disabled
2724 since December 2007.
2726 * The "catch exception" and "catch assert" commands now accept
2727 a condition at the end of the command, much like the "break"
2728 command does. For instance:
2730 (gdb) catch exception Constraint_Error if Barrier = True
2732 Previously, it was possible to add a condition to such catchpoints,
2733 but it had to be done as a second step, after the catchpoint had been
2734 created, using the "condition" command.
2736 * The "info static-tracepoint-marker" command will now also work on
2737 native Linux targets with in-process agent.
2739 * GDB can now set breakpoints on inlined functions.
2741 * The .gdb_index section has been updated to include symbols for
2742 inlined functions. GDB will ignore older .gdb_index sections by
2743 default, which could cause symbol files to be loaded more slowly
2744 until their .gdb_index sections can be recreated. The new command
2745 "set use-deprecated-index-sections on" will cause GDB to use any older
2746 .gdb_index sections it finds. This will restore performance, but the
2747 ability to set breakpoints on inlined functions will be lost in symbol
2748 files with older .gdb_index sections.
2750 The .gdb_index section has also been updated to record more information
2751 about each symbol. This speeds up the "info variables", "info functions"
2752 and "info types" commands when used with programs having the .gdb_index
2753 section, as well as speeding up debugging with shared libraries using
2754 the .gdb_index section.
2756 * Ada support for GDB/MI Variable Objects has been added.
2758 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2763 ** New command -info-os is the MI equivalent of "info os".
2765 ** Output logs ("set logging" and related) now include MI output.
2769 ** "set use-deprecated-index-sections on|off"
2770 "show use-deprecated-index-sections on|off"
2771 Controls the use of deprecated .gdb_index sections.
2773 ** "catch load" and "catch unload" can be used to stop when a shared
2774 library is loaded or unloaded, respectively.
2776 ** "enable count" can be used to auto-disable a breakpoint after
2779 ** "info vtbl" can be used to show the virtual method tables for
2780 C++ and Java objects.
2782 ** "explore" and its sub commands "explore value" and "explore type"
2783 can be used to recursively explore values and types of
2784 expressions. These commands are available only if GDB is
2785 configured with '--with-python'.
2787 ** "info auto-load" shows status of all kinds of auto-loaded files,
2788 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2789 sequences of commands files, "info auto-load python-scripts"
2790 shows status of auto-loading Python script files,
2791 "info auto-load local-gdbinit" shows status of loading init file
2792 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2793 status of inferior specific thread debugging shared library loading.
2795 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2796 and "show auto-load-scripts" commands have been deprecated, use their
2797 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2798 and "show auto-load python-scripts" counterparts instead.
2800 ** "dprintf location,format,args..." creates a dynamic printf, which
2801 is basically a breakpoint that does a printf and immediately
2802 resumes your program's execution, so it is like a printf that you
2803 can insert dynamically at runtime instead of at compiletime.
2805 ** "set print symbol"
2807 Controls whether GDB attempts to display the symbol, if any,
2808 corresponding to addresses it prints. This defaults to "on", but
2809 you can set it to "off" to restore GDB's previous behavior.
2811 * Deprecated commands
2813 ** For the Renesas Super-H architecture, the "regs" command has been
2814 deprecated, and "info all-registers" should be used instead.
2818 Renesas RL78 rl78-*-elf
2819 HP OpenVMS ia64 ia64-hp-openvms*
2821 * GDBserver supports evaluation of breakpoint conditions. When
2822 support is advertised by GDBserver, GDB may be told to send the
2823 breakpoint conditions in bytecode form to GDBserver. GDBserver
2824 will only report the breakpoint trigger to GDB when its condition
2829 set mips compression
2830 show mips compression
2831 Select the compressed ISA encoding used in functions that have no symbol
2832 information available. The encoding can be set to either of:
2835 and is updated automatically from ELF file flags if available.
2837 set breakpoint condition-evaluation
2838 show breakpoint condition-evaluation
2839 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2840 GDBserver ("target"). Default option "auto" chooses the most efficient
2842 This option can improve debugger efficiency depending on the speed of the
2846 Disable auto-loading globally.
2849 Show auto-loading setting of all kinds of auto-loaded files.
2851 set auto-load gdb-scripts on|off
2852 show auto-load gdb-scripts
2853 Control auto-loading of GDB canned sequences of commands files.
2855 set auto-load python-scripts on|off
2856 show auto-load python-scripts
2857 Control auto-loading of Python script files.
2859 set auto-load local-gdbinit on|off
2860 show auto-load local-gdbinit
2861 Control loading of init file (.gdbinit) from current directory.
2863 set auto-load libthread-db on|off
2864 show auto-load libthread-db
2865 Control auto-loading of inferior specific thread debugging shared library.
2867 set auto-load scripts-directory <dir1>[:<dir2>...]
2868 show auto-load scripts-directory
2869 Set a list of directories from which to load auto-loaded scripts.
2870 Automatically loaded Python scripts and GDB scripts are located in one
2871 of the directories listed by this option.
2872 The delimiter (':' above) may differ according to the host platform.
2874 set auto-load safe-path <dir1>[:<dir2>...]
2875 show auto-load safe-path
2876 Set a list of directories from which it is safe to auto-load files.
2877 The delimiter (':' above) may differ according to the host platform.
2879 set debug auto-load on|off
2880 show debug auto-load
2881 Control display of debugging info for auto-loading the files above.
2883 set dprintf-style gdb|call|agent
2885 Control the way in which a dynamic printf is performed; "gdb"
2886 requests a GDB printf command, while "call" causes dprintf to call a
2887 function in the inferior. "agent" requests that the target agent
2888 (such as GDBserver) do the printing.
2890 set dprintf-function <expr>
2891 show dprintf-function
2892 set dprintf-channel <expr>
2893 show dprintf-channel
2894 Set the function and optional first argument to the call when using
2895 the "call" style of dynamic printf.
2897 set disconnected-dprintf on|off
2898 show disconnected-dprintf
2899 Control whether agent-style dynamic printfs continue to be in effect
2900 after GDB disconnects.
2902 * New configure options
2904 --with-auto-load-dir
2905 Configure default value for the 'set auto-load scripts-directory'
2906 setting above. It defaults to '$debugdir:$datadir/auto-load',
2907 $debugdir representing global debugging info directories (available
2908 via 'show debug-file-directory') and $datadir representing GDB's data
2909 directory (available via 'show data-directory').
2911 --with-auto-load-safe-path
2912 Configure default value for the 'set auto-load safe-path' setting
2913 above. It defaults to the --with-auto-load-dir setting.
2915 --without-auto-load-safe-path
2916 Set 'set auto-load safe-path' to '/', effectively disabling this
2919 * New remote packets
2921 z0/z1 conditional breakpoints extension
2923 The z0/z1 breakpoint insertion packets have been extended to carry
2924 a list of conditional expressions over to the remote stub depending on the
2925 condition evaluation mode. The use of this extension can be controlled
2926 via the "set remote conditional-breakpoints-packet" command.
2930 Specify the signals which the remote stub may pass to the debugged
2931 program without GDB involvement.
2933 * New command line options
2935 --init-command=FILE, -ix Like --command, -x but execute it
2936 before loading inferior.
2937 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2938 execute it before loading inferior.
2940 *** Changes in GDB 7.4
2942 * GDB now handles ambiguous linespecs more consistently; the existing
2943 FILE:LINE support has been expanded to other types of linespecs. A
2944 breakpoint will now be set on all matching locations in all
2945 inferiors, and locations will be added or removed according to
2948 * GDB now allows you to skip uninteresting functions and files when
2949 stepping with the "skip function" and "skip file" commands.
2951 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2952 and "show remote hardware-watchpoint-length-limit". These allows to
2953 set or show the maximum length limit (in bytes) of a remote
2954 target hardware watchpoint.
2956 This allows e.g. to use "unlimited" hardware watchpoints with the
2957 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2958 watchpoints are slower than real hardware watchpoints but are
2959 significantly faster than gdb software watchpoints.
2963 ** The register_pretty_printer function in module gdb.printing now takes
2964 an optional `replace' argument. If True, the new printer replaces any
2967 ** The "maint set python print-stack on|off" command has been
2968 deprecated and will be deleted in GDB 7.5.
2969 A new command: "set python print-stack none|full|message" has
2970 replaced it. Additionally, the default for "print-stack" is
2971 now "message", which just prints the error message without
2974 ** A prompt substitution hook (prompt_hook) is now available to the
2977 ** A new Python module, gdb.prompt has been added to the GDB Python
2978 modules library. This module provides functionality for
2979 escape sequences in prompts (used by set/show
2980 extended-prompt). These escape sequences are replaced by their
2981 corresponding value.
2983 ** Python commands and convenience-functions located in
2984 'data-directory'/python/gdb/command and
2985 'data-directory'/python/gdb/function are now automatically loaded
2988 ** Blocks now provide four new attributes. global_block and
2989 static_block will return the global and static blocks
2990 respectively. is_static and is_global are boolean attributes
2991 that indicate if the block is one of those two types.
2993 ** Symbols now provide the "type" attribute, the type of the symbol.
2995 ** The "gdb.breakpoint" function has been deprecated in favor of
2998 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2999 of a function. This class is based on the "finish" command
3000 available in the CLI.
3002 ** Type objects for struct and union types now allow access to
3003 the fields using standard Python dictionary (mapping) methods.
3004 For example, "some_type['myfield']" now works, as does
3005 "some_type.items()".
3007 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3010 ** A new function, "deep_items" has been added to the gdb.types
3011 module in the GDB Python modules library. This function returns
3012 an iterator over the fields of a struct or union type. Unlike
3013 the standard Python "iteritems" method, it will recursively traverse
3014 any anonymous fields.
3018 ** "*stopped" events can report several new "reason"s, such as
3021 ** Breakpoint changes are now notified using new async records, like
3022 "=breakpoint-modified".
3024 ** New command -ada-task-info.
3026 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3027 $sdir specifies the default system locations of shared libraries.
3028 $pdir specifies the directory where the libpthread used by the application
3031 GDB no longer looks in $sdir and $pdir after it has searched the directories
3032 mentioned in libthread-db-search-path. If you want to search those
3033 directories, they must be specified in libthread-db-search-path.
3034 The default value of libthread-db-search-path on GNU/Linux and Solaris
3035 systems is now "$sdir:$pdir".
3037 $pdir is not supported by gdbserver, it is currently ignored.
3038 $sdir is supported by gdbserver.
3040 * New configure option --with-iconv-bin.
3041 When using the internationalization support like the one in the GNU C
3042 library, GDB will invoke the "iconv" program to get a list of supported
3043 character sets. If this program lives in a non-standard location, one can
3044 use this option to specify where to find it.
3046 * When natively debugging programs on PowerPC BookE processors running
3047 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3048 watchpoints, which specify a mask in addition to an address to watch.
3049 The mask specifies that some bits of an address (the bits which are
3050 reset in the mask) should be ignored when matching the address accessed
3051 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3052 section in the user manual for more details.
3054 * The new option --once causes GDBserver to stop listening for connections once
3055 the first connection is made. The listening port used by GDBserver will
3056 become available after that.
3058 * New commands "info macros" and "alias" have been added.
3060 * New function parameters suffix @entry specifies value of function parameter
3061 at the time the function got called. Entry values are available only since
3067 "!" is now an alias of the "shell" command.
3068 Note that no space is needed between "!" and SHELL COMMAND.
3072 watch EXPRESSION mask MASK_VALUE
3073 The watch command now supports the mask argument which allows creation
3074 of masked watchpoints, if the current architecture supports this feature.
3076 info auto-load-scripts [REGEXP]
3077 This command was formerly named "maintenance print section-scripts".
3078 It is now generally useful and is no longer a maintenance-only command.
3080 info macro [-all] [--] MACRO
3081 The info macro command has new options `-all' and `--'. The first for
3082 printing all definitions of a macro. The second for explicitly specifying
3083 the end of arguments and the beginning of the macro name in case the macro
3084 name starts with a hyphen.
3086 collect[/s] EXPRESSIONS
3087 The tracepoint collect command now takes an optional modifier "/s"
3088 that directs it to dereference pointer-to-character types and
3089 collect the bytes of memory up to a zero byte. The behavior is
3090 similar to what you see when you use the regular print command on a
3091 string. An optional integer following the "/s" sets a bound on the
3092 number of bytes that will be collected.
3095 The trace start command now interprets any supplied arguments as a
3096 note to be recorded with the trace run, with an effect similar to
3097 setting the variable trace-notes.
3100 The trace stop command now interprets any arguments as a note to be
3101 mentioned along with the tstatus report that the trace was stopped
3102 with a command. The effect is similar to setting the variable
3105 * Tracepoints can now be enabled and disabled at any time after a trace
3106 experiment has been started using the standard "enable" and "disable"
3107 commands. It is now possible to start a trace experiment with no enabled
3108 tracepoints; GDB will display a warning, but will allow the experiment to
3109 begin, assuming that tracepoints will be enabled as needed while the trace
3112 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3113 locations with 4-byte instructions, when they were previously
3114 limited to locations with instructions of 5 bytes or longer.
3118 set debug dwarf2-read
3119 show debug dwarf2-read
3120 Turns on or off display of debugging messages related to reading
3121 DWARF debug info. The default is off.
3123 set debug symtab-create
3124 show debug symtab-create
3125 Turns on or off display of debugging messages related to symbol table
3126 creation. The default is off.
3129 show extended-prompt
3130 Set the GDB prompt, and allow escape sequences to be inserted to
3131 display miscellaneous information (see 'help set extended-prompt'
3132 for the list of sequences). This prompt (and any information
3133 accessed through the escape sequences) is updated every time the
3134 prompt is displayed.
3136 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3137 show print entry-values
3138 Set printing of frame argument values at function entry. In some cases
3139 GDB can determine the value of function argument which was passed by the
3140 function caller, even if the value was modified inside the called function.
3142 set debug entry-values
3143 show debug entry-values
3144 Control display of debugging info for determining frame argument values at
3145 function entry and virtual tail call frames.
3147 set basenames-may-differ
3148 show basenames-may-differ
3149 Set whether a source file may have multiple base names.
3150 (A "base name" is the name of a file with the directory part removed.
3151 Example: The base name of "/home/user/hello.c" is "hello.c".)
3152 If set, GDB will canonicalize file names (e.g., expand symlinks)
3153 before comparing them. Canonicalization is an expensive operation,
3154 but it allows the same file be known by more than one base name.
3155 If not set (the default), all source files are assumed to have just
3156 one base name, and gdb will do file name comparisons more efficiently.
3162 Set a user name and notes for the current and any future trace runs.
3163 This is useful for long-running and/or disconnected traces, to
3164 inform others (or yourself) as to who is running the trace, supply
3165 contact information, or otherwise explain what is going on.
3167 set trace-stop-notes
3168 show trace-stop-notes
3169 Set a note attached to the trace run, that is displayed when the
3170 trace has been stopped by a tstop command. This is useful for
3171 instance as an explanation, if you are stopping a trace run that was
3172 started by someone else.
3174 * New remote packets
3178 Dynamically enable a tracepoint in a started trace experiment.
3182 Dynamically disable a tracepoint in a started trace experiment.
3186 Set the user and notes of the trace run.
3190 Query the current status of a tracepoint.
3194 Query the minimum length of instruction at which a fast tracepoint may
3197 * Dcache size (number of lines) and line-size are now runtime-configurable
3198 via "set dcache line" and "set dcache line-size" commands.
3202 Texas Instruments TMS320C6x tic6x-*-*
3206 Renesas RL78 rl78-*-elf
3208 *** Changes in GDB 7.3.1
3210 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3212 *** Changes in GDB 7.3
3214 * GDB has a new command: "thread find [REGEXP]".
3215 It finds the thread id whose name, target id, or thread extra info
3216 matches the given regular expression.
3218 * The "catch syscall" command now works on mips*-linux* targets.
3220 * The -data-disassemble MI command now supports modes 2 and 3 for
3221 dumping the instruction opcodes.
3223 * New command line options
3225 -data-directory DIR Specify DIR as the "data-directory".
3226 This is mostly for testing purposes.
3228 * The "maint set python auto-load on|off" command has been renamed to
3229 "set auto-load-scripts on|off".
3231 * GDB has a new command: "set directories".
3232 It is like the "dir" command except that it replaces the
3233 source path list instead of augmenting it.
3235 * GDB now understands thread names.
3237 On GNU/Linux, "info threads" will display the thread name as set by
3238 prctl or pthread_setname_np.
3240 There is also a new command, "thread name", which can be used to
3241 assign a name internally for GDB to display.
3244 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3245 has been integrated into GDB.
3249 ** The function gdb.Write now accepts an optional keyword 'stream'.
3250 This keyword, when provided, will direct the output to either
3251 stdout, stderr, or GDB's logging output.
3253 ** Parameters can now be be sub-classed in Python, and in particular
3254 you may implement the get_set_doc and get_show_doc functions.
3255 This improves how Parameter set/show documentation is processed
3256 and allows for more dynamic content.
3258 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3259 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3260 have an is_valid method.
3262 ** Breakpoints can now be sub-classed in Python, and in particular
3263 you may implement a 'stop' function that is executed each time
3264 the inferior reaches that breakpoint.
3266 ** New function gdb.lookup_global_symbol looks up a global symbol.
3268 ** GDB values in Python are now callable if the value represents a
3269 function. For example, if 'some_value' represents a function that
3270 takes two integer parameters and returns a value, you can call
3271 that function like so:
3273 result = some_value (10,20)
3275 ** Module gdb.types has been added.
3276 It contains a collection of utilities for working with gdb.Types objects:
3277 get_basic_type, has_field, make_enum_dict.
3279 ** Module gdb.printing has been added.
3280 It contains utilities for writing and registering pretty-printers.
3281 New classes: PrettyPrinter, SubPrettyPrinter,
3282 RegexpCollectionPrettyPrinter.
3283 New function: register_pretty_printer.
3285 ** New commands "info pretty-printers", "enable pretty-printer" and
3286 "disable pretty-printer" have been added.
3288 ** gdb.parameter("directories") is now available.
3290 ** New function gdb.newest_frame returns the newest frame in the
3293 ** The gdb.InferiorThread class has a new "name" attribute. This
3294 holds the thread's name.
3296 ** Python Support for Inferior events.
3297 Python scripts can add observers to be notified of events
3298 occurring in the process being debugged.
3299 The following events are currently supported:
3300 - gdb.events.cont Continue event.
3301 - gdb.events.exited Inferior exited event.
3302 - gdb.events.stop Signal received, and Breakpoint hit events.
3306 ** GDB now puts template parameters in scope when debugging in an
3307 instantiation. For example, if you have:
3309 template<int X> int func (void) { return X; }
3311 then if you step into func<5>, "print X" will show "5". This
3312 feature requires proper debuginfo support from the compiler; it
3313 was added to GCC 4.5.
3315 ** The motion commands "next", "finish", "until", and "advance" now
3316 work better when exceptions are thrown. In particular, GDB will
3317 no longer lose control of the inferior; instead, the GDB will
3318 stop the inferior at the point at which the exception is caught.
3319 This functionality requires a change in the exception handling
3320 code that was introduced in GCC 4.5.
3322 * GDB now follows GCC's rules on accessing volatile objects when
3323 reading or writing target state during expression evaluation.
3324 One notable difference to prior behavior is that "print x = 0"
3325 no longer generates a read of x; the value of the assignment is
3326 now always taken directly from the value being assigned.
3328 * GDB now has some support for using labels in the program's source in
3329 linespecs. For instance, you can use "advance label" to continue
3330 execution to a label.
3332 * GDB now has support for reading and writing a new .gdb_index
3333 section. This section holds a fast index of DWARF debugging
3334 information and can be used to greatly speed up GDB startup and
3335 operation. See the documentation for `save gdb-index' for details.
3337 * The "watch" command now accepts an optional "-location" argument.
3338 When used, this causes GDB to watch the memory referred to by the
3339 expression. Such a watchpoint is never deleted due to it going out
3342 * GDB now supports thread debugging of core dumps on GNU/Linux.
3344 GDB now activates thread debugging using the libthread_db library
3345 when debugging GNU/Linux core dumps, similarly to when debugging
3346 live processes. As a result, when debugging a core dump file, GDB
3347 is now able to display pthread_t ids of threads. For example, "info
3348 threads" shows the same output as when debugging the process when it
3349 was live. In earlier releases, you'd see something like this:
3352 * 1 LWP 6780 main () at main.c:10
3354 While now you see this:
3357 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3359 It is also now possible to inspect TLS variables when debugging core
3362 When debugging a core dump generated on a machine other than the one
3363 used to run GDB, you may need to point GDB at the correct
3364 libthread_db library with the "set libthread-db-search-path"
3365 command. See the user manual for more details on this command.
3367 * When natively debugging programs on PowerPC BookE processors running
3368 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3369 which stop execution of the inferior whenever it executes an instruction
3370 at any address within the specified range. See the "PowerPC Embedded"
3371 section in the user manual for more details.
3373 * New features in the GDB remote stub, GDBserver
3375 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3376 and i686 LynxOS (version 5.x).
3378 ** GDBserver is now supported on Blackfin Linux.
3380 * New native configurations
3382 ia64 HP-UX ia64-*-hpux*
3386 Analog Devices, Inc. Blackfin Processor bfin-*
3388 * Ada task switching is now supported on sparc-elf targets when
3389 debugging a program using the Ravenscar Profile. For more information,
3390 see the "Tasking Support when using the Ravenscar Profile" section
3391 in the GDB user manual.
3393 * Guile support was removed.
3395 * New features in the GNU simulator
3397 ** The --map-info flag lists all known core mappings.
3399 ** CFI flashes may be simulated via the "cfi" device.
3401 *** Changes in GDB 7.2
3403 * Shared library support for remote targets by default
3405 When GDB is configured for a generic, non-OS specific target, like
3406 for example, --target=arm-eabi or one of the many *-*-elf targets,
3407 GDB now queries remote stubs for loaded shared libraries using the
3408 `qXfer:libraries:read' packet. Previously, shared library support
3409 was always disabled for such configurations.
3413 ** Argument Dependent Lookup (ADL)
3415 In C++ ADL lookup directs function search to the namespaces of its
3416 arguments even if the namespace has not been imported.
3426 Here the compiler will search for `foo' in the namespace of 'b'
3427 and find A::foo. GDB now supports this. This construct is commonly
3428 used in the Standard Template Library for operators.
3430 ** Improved User Defined Operator Support
3432 In addition to member operators, GDB now supports lookup of operators
3433 defined in a namespace and imported with a `using' directive, operators
3434 defined in the global scope, operators imported implicitly from an
3435 anonymous namespace, and the ADL operators mentioned in the previous
3437 GDB now also supports proper overload resolution for all the previously
3438 mentioned flavors of operators.
3440 ** static const class members
3442 Printing of static const class members that are initialized in the
3443 class definition has been fixed.
3445 * Windows Thread Information Block access.
3447 On Windows targets, GDB now supports displaying the Windows Thread
3448 Information Block (TIB) structure. This structure is visible either
3449 by using the new command `info w32 thread-information-block' or, by
3450 dereferencing the new convenience variable named `$_tlb', a
3451 thread-specific pointer to the TIB. This feature is also supported
3452 when remote debugging using GDBserver.
3454 * Static tracepoints
3456 Static tracepoints are calls in the user program into a tracing
3457 library. One such library is a port of the LTTng kernel tracer to
3458 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3459 When debugging with GDBserver, GDB now supports combining the GDB
3460 tracepoint machinery with such libraries. For example: the user can
3461 use GDB to probe a static tracepoint marker (a call from the user
3462 program into the tracing library) with the new "strace" command (see
3463 "New commands" below). This creates a "static tracepoint" in the
3464 breakpoint list, that can be manipulated with the same feature set
3465 as fast and regular tracepoints. E.g., collect registers, local and
3466 global variables, collect trace state variables, and define
3467 tracepoint conditions. In addition, the user can collect extra
3468 static tracepoint marker specific data, by collecting the new
3469 $_sdata internal variable. When analyzing the trace buffer, you can
3470 inspect $_sdata like any other variable available to GDB. For more
3471 information, see the "Tracepoints" chapter in GDB user manual. New
3472 remote packets have been defined to support static tracepoints, see
3473 the "New remote packets" section below.
3475 * Better reconstruction of tracepoints after disconnected tracing
3477 GDB will attempt to download the original source form of tracepoint
3478 definitions when starting a trace run, and then will upload these
3479 upon reconnection to the target, resulting in a more accurate
3480 reconstruction of the tracepoints that are in use on the target.
3484 You can now exercise direct control over the ways that GDB can
3485 affect your program. For instance, you can disallow the setting of
3486 breakpoints, so that the program can run continuously (assuming
3487 non-stop mode). In addition, the "observer" variable is available
3488 to switch all of the different controls; in observer mode, GDB
3489 cannot affect the target's behavior at all, which is useful for
3490 tasks like diagnosing live systems in the field.
3492 * The new convenience variable $_thread holds the number of the
3495 * New remote packets
3499 Return the address of the Windows Thread Information Block of a given thread.
3503 In response to several of the tracepoint packets, the target may now
3504 also respond with a number of intermediate `qRelocInsn' request
3505 packets before the final result packet, to have GDB handle
3506 relocating an instruction to execute at a different address. This
3507 is particularly useful for stubs that support fast tracepoints. GDB
3508 reports support for this feature in the qSupported packet.
3512 List static tracepoint markers in the target program.
3516 List static tracepoint markers at a given address in the target
3519 qXfer:statictrace:read
3521 Read the static trace data collected (by a `collect $_sdata'
3522 tracepoint action). The remote stub reports support for this packet
3523 to gdb's qSupported query.
3527 Send the current settings of GDB's permission flags.
3531 Send part of the source (textual) form of a tracepoint definition,
3532 which includes location, conditional, and action list.
3534 * The source command now accepts a -s option to force searching for the
3535 script in the source search path even if the script name specifies
3538 * New features in the GDB remote stub, GDBserver
3540 - GDBserver now support tracepoints (including fast tracepoints, and
3541 static tracepoints). The feature is currently supported by the
3542 i386-linux and amd64-linux builds. See the "Tracepoints support
3543 in gdbserver" section in the manual for more information.
3545 GDBserver JIT compiles the tracepoint's conditional agent
3546 expression bytecode into native code whenever possible for low
3547 overhead dynamic tracepoints conditionals. For such tracepoints,
3548 an expression that examines program state is evaluated when the
3549 tracepoint is reached, in order to determine whether to capture
3550 trace data. If the condition is simple and false, processing the
3551 tracepoint finishes very quickly and no data is gathered.
3553 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3554 for static tracepoints support.
3556 - GDBserver now supports x86_64 Windows 64-bit debugging.
3558 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3559 it understands register description.
3561 * The --batch flag now disables pagination and queries.
3563 * X86 general purpose registers
3565 GDB now supports reading/writing byte, word and double-word x86
3566 general purpose registers directly. This means you can use, say,
3567 $ah or $ax to refer, respectively, to the byte register AH and
3568 16-bit word register AX that are actually portions of the 32-bit
3569 register EAX or 64-bit register RAX.
3571 * The `commands' command now accepts a range of breakpoints to modify.
3572 A plain `commands' following a command that creates multiple
3573 breakpoints affects all the breakpoints set by that command. This
3574 applies to breakpoints set by `rbreak', and also applies when a
3575 single `break' command creates multiple breakpoints (e.g.,
3576 breakpoints on overloaded c++ functions).
3578 * The `rbreak' command now accepts a filename specification as part of
3579 its argument, limiting the functions selected by the regex to those
3580 in the specified file.
3582 * Support for remote debugging Windows and SymbianOS shared libraries
3583 from Unix hosts has been improved. Non Windows GDB builds now can
3584 understand target reported file names that follow MS-DOS based file
3585 system semantics, such as file names that include drive letters and
3586 use the backslash character as directory separator. This makes it
3587 possible to transparently use the "set sysroot" and "set
3588 solib-search-path" on Unix hosts to point as host copies of the
3589 target's shared libraries. See the new command "set
3590 target-file-system-kind" described below, and the "Commands to
3591 specify files" section in the user manual for more information.
3595 eval template, expressions...
3596 Convert the values of one or more expressions under the control
3597 of the string template to a command line, and call it.
3599 set target-file-system-kind unix|dos-based|auto
3600 show target-file-system-kind
3601 Set or show the assumed file system kind for target reported file
3604 save breakpoints <filename>
3605 Save all current breakpoint definitions to a file suitable for use
3606 in a later debugging session. To read the saved breakpoint
3607 definitions, use the `source' command.
3609 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3612 info static-tracepoint-markers
3613 Display information about static tracepoint markers in the target.
3615 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3616 Define a static tracepoint by probing a marker at the given
3617 function, line, address, or marker ID.
3621 Enable and disable observer mode.
3623 set may-write-registers on|off
3624 set may-write-memory on|off
3625 set may-insert-breakpoints on|off
3626 set may-insert-tracepoints on|off
3627 set may-insert-fast-tracepoints on|off
3628 set may-interrupt on|off
3629 Set individual permissions for GDB effects on the target. Note that
3630 some of these settings can have undesirable or surprising
3631 consequences, particularly when changed in the middle of a session.
3632 For instance, disabling the writing of memory can prevent
3633 breakpoints from being inserted, cause single-stepping to fail, or
3634 even crash your program, if you disable after breakpoints have been
3635 inserted. However, GDB should not crash.
3637 set record memory-query on|off
3638 show record memory-query
3639 Control whether to stop the inferior if memory changes caused
3640 by an instruction cannot be recorded.
3645 The disassemble command now supports "start,+length" form of two arguments.
3649 ** GDB now provides a new directory location, called the python directory,
3650 where Python scripts written for GDB can be installed. The location
3651 of that directory is <data-directory>/python, where <data-directory>
3652 is the GDB data directory. For more details, see section `Scripting
3653 GDB using Python' in the manual.
3655 ** The GDB Python API now has access to breakpoints, symbols, symbol
3656 tables, program spaces, inferiors, threads and frame's code blocks.
3657 Additionally, GDB Parameters can now be created from the API, and
3658 manipulated via set/show in the CLI.
3660 ** New functions gdb.target_charset, gdb.target_wide_charset,
3661 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3663 ** New exception gdb.GdbError.
3665 ** Pretty-printers are now also looked up in the current program space.
3667 ** Pretty-printers can now be individually enabled and disabled.
3669 ** GDB now looks for names of Python scripts to auto-load in a
3670 special section named `.debug_gdb_scripts', in addition to looking
3671 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3673 * Tracepoint actions were unified with breakpoint commands. In particular,
3674 there are no longer differences in "info break" output for breakpoints and
3675 tracepoints and the "commands" command can be used for both tracepoints and
3676 regular breakpoints.
3680 ARM Symbian arm*-*-symbianelf*
3682 * D language support.
3683 GDB now supports debugging programs written in the D programming
3686 * GDB now supports the extended ptrace interface for PowerPC which is
3687 available since Linux kernel version 2.6.34. This automatically enables
3688 any hardware breakpoints and additional hardware watchpoints available in
3689 the processor. The old ptrace interface exposes just one hardware
3690 watchpoint and no hardware breakpoints.
3692 * GDB is now able to use the Data Value Compare (DVC) register available on
3693 embedded PowerPC processors to implement in hardware simple watchpoint
3694 conditions of the form:
3696 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3698 This works in native GDB running on Linux kernels with the extended ptrace
3699 interface mentioned above.
3701 *** Changes in GDB 7.1
3705 ** Namespace Support
3707 GDB now supports importing of namespaces in C++. This enables the
3708 user to inspect variables from imported namespaces. Support for
3709 namepace aliasing has also been added. So, if a namespace is
3710 aliased in the current scope (e.g. namepace C=A; ) the user can
3711 print variables using the alias (e.g. (gdb) print C::x).
3715 All known bugs relating to the printing of virtual base class were
3716 fixed. It is now possible to call overloaded static methods using a
3721 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3722 and reinterpret_cast<> are now handled by the C++ expression parser.
3726 Xilinx MicroBlaze microblaze-*-*
3731 Xilinx MicroBlaze microblaze
3734 * Multi-program debugging.
3736 GDB now has support for multi-program (a.k.a. multi-executable or
3737 multi-exec) debugging. This allows for debugging multiple inferiors
3738 simultaneously each running a different program under the same GDB
3739 session. See "Debugging Multiple Inferiors and Programs" in the
3740 manual for more information. This implied some user visible changes
3741 in the multi-inferior support. For example, "info inferiors" now
3742 lists inferiors that are not running yet or that have exited
3743 already. See also "New commands" and "New options" below.
3745 * New tracing features
3747 GDB's tracepoint facility now includes several new features:
3749 ** Trace state variables
3751 GDB tracepoints now include support for trace state variables, which
3752 are variables managed by the target agent during a tracing
3753 experiment. They are useful for tracepoints that trigger each
3754 other, so for instance one tracepoint can count hits in a variable,
3755 and then a second tracepoint has a condition that is true when the
3756 count reaches a particular value. Trace state variables share the
3757 $-syntax of GDB convenience variables, and can appear in both
3758 tracepoint actions and condition expressions. Use the "tvariable"
3759 command to create, and "info tvariables" to view; see "Trace State
3760 Variables" in the manual for more detail.
3764 GDB now includes an option for defining fast tracepoints, which
3765 targets may implement more efficiently, such as by installing a jump
3766 into the target agent rather than a trap instruction. The resulting
3767 speedup can be by two orders of magnitude or more, although the
3768 tradeoff is that some program locations on some target architectures
3769 might not allow fast tracepoint installation, for instance if the
3770 instruction to be replaced is shorter than the jump. To request a
3771 fast tracepoint, use the "ftrace" command, with syntax identical to
3772 the regular trace command.
3774 ** Disconnected tracing
3776 It is now possible to detach GDB from the target while it is running
3777 a trace experiment, then reconnect later to see how the experiment
3778 is going. In addition, a new variable disconnected-tracing lets you
3779 tell the target agent whether to continue running a trace if the
3780 connection is lost unexpectedly.
3784 GDB now has the ability to save the trace buffer into a file, and
3785 then use that file as a target, similarly to you can do with
3786 corefiles. You can select trace frames, print data that was
3787 collected in them, and use tstatus to display the state of the
3788 tracing run at the moment that it was saved. To create a trace
3789 file, use "tsave <filename>", and to use it, do "target tfile
3792 ** Circular trace buffer
3794 You can ask the target agent to handle the trace buffer as a
3795 circular buffer, discarding the oldest trace frames to make room for
3796 newer ones, by setting circular-trace-buffer to on. This feature may
3797 not be available for all target agents.
3802 The disassemble command, when invoked with two arguments, now requires
3803 the arguments to be comma-separated.
3806 The info variables command now displays variable definitions. Files
3807 which only declare a variable are not shown.
3810 The source command is now capable of sourcing Python scripts.
3811 This feature is dependent on the debugger being build with Python
3814 Related to this enhancement is also the introduction of a new command
3815 "set script-extension" (see below).
3817 * New commands (for set/show, see "New options" below)
3819 record save [<FILENAME>]
3820 Save a file (in core file format) containing the process record
3821 execution log for replay debugging at a later time.
3823 record restore <FILENAME>
3824 Restore the process record execution log that was saved at an
3825 earlier time, for replay debugging.
3827 add-inferior [-copies <N>] [-exec <FILENAME>]
3830 clone-inferior [-copies <N>] [ID]
3831 Make a new inferior ready to execute the same program another
3832 inferior has loaded.
3837 maint info program-spaces
3838 List the program spaces loaded into GDB.
3840 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3841 show remote interrupt-sequence
3842 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3843 as the sequence to the remote target in order to interrupt the execution.
3844 Ctrl-C is a default. Some system prefers BREAK which is high level of
3845 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3846 Magic SysRq g. It is BREAK signal and character 'g'.
3848 set remote interrupt-on-connect [on | off]
3849 show remote interrupt-on-connect
3850 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3851 remote target when gdb connects to it. This is needed when you debug
3854 set remotebreak [on | off]
3856 Deprecated. Use "set/show remote interrupt-sequence" instead.
3858 tvariable $NAME [ = EXP ]
3859 Create or modify a trace state variable.
3862 List trace state variables and their values.
3864 delete tvariable $NAME ...
3865 Delete one or more trace state variables.
3868 Evaluate the given expressions without collecting anything into the
3869 trace buffer. (Valid in tracepoint actions only.)
3871 ftrace FN / FILE:LINE / *ADDR
3872 Define a fast tracepoint at the given function, line, or address.
3874 * New expression syntax
3876 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3877 GDB now parses 0b101010 identically with 42.
3881 set follow-exec-mode new|same
3882 show follow-exec-mode
3883 Control whether GDB reuses the same inferior across an exec call or
3884 creates a new one. This is useful to be able to restart the old
3885 executable after the inferior having done an exec call.
3887 set default-collect EXPR, ...
3888 show default-collect
3889 Define a list of expressions to be collected at each tracepoint.
3890 This is a useful way to ensure essential items are not overlooked,
3891 such as registers or a critical global variable.
3893 set disconnected-tracing
3894 show disconnected-tracing
3895 If set to 1, the target is instructed to continue tracing if it
3896 loses its connection to GDB. If 0, the target is to stop tracing
3899 set circular-trace-buffer
3900 show circular-trace-buffer
3901 If set to on, the target is instructed to use a circular trace buffer
3902 and discard the oldest trace frames instead of stopping the trace due
3903 to a full trace buffer. If set to off, the trace stops when the buffer
3904 fills up. Some targets may not support this.
3906 set script-extension off|soft|strict
3907 show script-extension
3908 If set to "off", the debugger does not perform any script language
3909 recognition, and all sourced files are assumed to be GDB scripts.
3910 If set to "soft" (the default), files are sourced according to
3911 filename extension, falling back to GDB scripts if the first
3913 If set to "strict", files are sourced according to filename extension.
3915 set ada trust-PAD-over-XVS on|off
3916 show ada trust-PAD-over-XVS
3917 If off, activate a workaround against a bug in the debugging information
3918 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3919 the GCC sources for more information about the GNAT encoding and
3920 PAD types in particular). It is always safe to set this option to
3921 off, but this introduces a slight performance penalty. The default
3924 * Python API Improvements
3926 ** GDB provides the new class gdb.LazyString. This is useful in
3927 some pretty-printing cases. The new method gdb.Value.lazy_string
3928 provides a simple way to create objects of this type.
3930 ** The fields returned by gdb.Type.fields now have an
3931 `is_base_class' attribute.
3933 ** The new method gdb.Type.range returns the range of an array type.
3935 ** The new method gdb.parse_and_eval can be used to parse and
3936 evaluate an expression.
3938 * New remote packets
3941 Define a trace state variable.
3944 Get the current value of a trace state variable.
3947 Set desired tracing behavior upon disconnection.
3950 Set the trace buffer to be linear or circular.
3953 Get data about the tracepoints currently in use.
3957 Process record now works correctly with hardware watchpoints.
3959 Multiple bug fixes have been made to the mips-irix port, making it
3960 much more reliable. In particular:
3961 - Debugging threaded applications is now possible again. Previously,
3962 GDB would hang while starting the program, or while waiting for
3963 the program to stop at a breakpoint.
3964 - Attaching to a running process no longer hangs.
3965 - An error occurring while loading a core file has been fixed.
3966 - Changing the value of the PC register now works again. This fixes
3967 problems observed when using the "jump" command, or when calling
3968 a function from GDB, or even when assigning a new value to $pc.
3969 - With the "finish" and "return" commands, the return value for functions
3970 returning a small array is now correctly printed.
3971 - It is now possible to break on shared library code which gets executed
3972 during a shared library init phase (code executed while executing
3973 their .init section). Previously, the breakpoint would have no effect.
3974 - GDB is now able to backtrace through the signal handler for
3975 non-threaded programs.
3977 PIE (Position Independent Executable) programs debugging is now supported.
3978 This includes debugging execution of PIC (Position Independent Code) shared
3979 libraries although for that, it should be possible to run such libraries as an
3982 *** Changes in GDB 7.0
3984 * GDB now has an interface for JIT compilation. Applications that
3985 dynamically generate code can create symbol files in memory and register
3986 them with GDB. For users, the feature should work transparently, and
3987 for JIT developers, the interface is documented in the GDB manual in the
3988 "JIT Compilation Interface" chapter.
3990 * Tracepoints may now be conditional. The syntax is as for
3991 breakpoints; either an "if" clause appended to the "trace" command,
3992 or the "condition" command is available. GDB sends the condition to
3993 the target for evaluation using the same bytecode format as is used
3994 for tracepoint actions.
3996 * The disassemble command now supports: an optional /r modifier, print the
3997 raw instructions in hex as well as in symbolic form, and an optional /m
3998 modifier to print mixed source+assembly.
4000 * Process record and replay
4002 In a architecture environment that supports ``process record and
4003 replay'', ``process record and replay'' target can record a log of
4004 the process execution, and replay it with both forward and reverse
4007 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4008 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4009 set execution-direction {forward|reverse}, for targets that support
4012 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4013 feature is available with a native GDB running on kernel version
4016 * GDB now has support for multi-byte and wide character sets on the
4017 target. Strings whose character type is wchar_t, char16_t, or
4018 char32_t are now correctly printed. GDB supports wide- and unicode-
4019 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4020 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4021 `printf'. This feature requires iconv to work properly; if your
4022 system does not have a working iconv, GDB can use GNU libiconv. See
4023 the installation instructions for more information.
4025 * GDB now supports automatic retrieval of shared library files from
4026 remote targets. To use this feature, specify a system root that begins
4027 with the `remote:' prefix, either via the `set sysroot' command or via
4028 the `--with-sysroot' configure-time option.
4030 * "info sharedlibrary" now takes an optional regex of libraries to show,
4031 and it now reports if a shared library has no debugging information.
4033 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4034 now complete on file names.
4036 * When completing in expressions, gdb will attempt to limit
4037 completions to allowable structure or union fields, where appropriate.
4038 For instance, consider:
4040 # struct example { int f1; double f2; };
4041 # struct example variable;
4044 If the user types TAB at the end of this command line, the available
4045 completions will be "f1" and "f2".
4047 * Inlined functions are now supported. They show up in backtraces, and
4048 the "step", "next", and "finish" commands handle them automatically.
4050 * GDB now supports the token-splicing (##) and stringification (#)
4051 operators when expanding macros. It also supports variable-arity
4054 * GDB now supports inspecting extra signal information, exported by
4055 the new $_siginfo convenience variable. The feature is currently
4056 implemented on linux ARM, i386 and amd64.
4058 * GDB can now display the VFP floating point registers and NEON vector
4059 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4060 can provide these registers (requires Linux 2.6.30 or later). Remote
4061 and simulator targets may also provide them.
4063 * New remote packets
4066 Search memory for a sequence of bytes.
4069 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4070 operation over reliable transport links. Use of this packet is
4071 controlled by the `set remote noack-packet' command.
4074 Kill the process with the specified process ID. Use this in preference
4075 to `k' when multiprocess protocol extensions are supported.
4078 Obtains additional operating system information
4082 Read or write additional signal information.
4084 * Removed remote protocol undocumented extension
4086 An undocumented extension to the remote protocol's `S' stop reply
4087 packet that permited the stub to pass a process id was removed.
4088 Remote servers should use the `T' stop reply packet instead.
4090 * GDB now supports multiple function calling conventions according to the
4091 DWARF-2 DW_AT_calling_convention function attribute.
4093 * The SH target utilizes the aforementioned change to distinguish between gcc
4094 and Renesas calling convention. It also adds the new CLI commands
4095 `set/show sh calling-convention'.
4097 * GDB can now read compressed debug sections, as produced by GNU gold
4098 with the --compress-debug-sections=zlib flag.
4100 * 64-bit core files are now supported on AIX.
4102 * Thread switching is now supported on Tru64.
4104 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4105 which will be allocated using malloc later in program execution.
4107 * The qXfer:libraries:read remote procotol packet now allows passing a
4108 list of section offsets.
4110 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4111 conditions handling signals delivered during attach or thread creation
4112 have also been fixed.
4114 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4115 From the user's standpoint, all unqualified instances of True and False
4116 are treated as the standard definitions, regardless of context.
4118 * GDB now parses C++ symbol and type names more flexibly. For
4121 template<typename T> class C { };
4124 GDB will now correctly handle all of:
4126 ptype C<char const *>
4127 ptype C<char const*>
4128 ptype C<const char *>
4129 ptype C<const char*>
4131 * New features in the GDB remote stub, gdbserver
4133 - The "--wrapper" command-line argument tells gdbserver to use a
4134 wrapper program to launch programs for debugging.
4136 - On PowerPC and S/390 targets, it is now possible to use a single
4137 gdbserver executable to debug both 32-bit and 64-bit programs.
4138 (This requires gdbserver itself to be built as a 64-bit executable.)
4140 - gdbserver uses the new noack protocol mode for TCP connections to
4141 reduce communications latency, if also supported and enabled in GDB.
4143 - Support for the sparc64-linux-gnu target is now included in
4146 - The amd64-linux build of gdbserver now supports debugging both
4147 32-bit and 64-bit programs.
4149 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4150 now support hardware watchpoints, and will use them automatically
4155 GDB now has support for scripting using Python. Whether this is
4156 available is determined at configure time.
4158 New GDB commands can now be written in Python.
4160 * Ada tasking support
4162 Ada tasks can now be inspected in GDB. The following commands have
4166 Print the list of Ada tasks.
4168 Print detailed information about task number N.
4170 Print the task number of the current task.
4172 Switch the context of debugging to task number N.
4174 * Support for user-defined prefixed commands. The "define" command can
4175 add new commands to existing prefixes, e.g. "target".
4177 * Multi-inferior, multi-process debugging.
4179 GDB now has generalized support for multi-inferior debugging. See
4180 "Debugging Multiple Inferiors" in the manual for more information.
4181 Although availability still depends on target support, the command
4182 set is more uniform now. The GNU/Linux specific multi-forks support
4183 has been migrated to this new framework. This implied some user
4184 visible changes; see "New commands" and also "Removed commands"
4187 * Target descriptions can now describe the target OS ABI. See the
4188 "Target Description Format" section in the user manual for more
4191 * Target descriptions can now describe "compatible" architectures
4192 to indicate that the target can execute applications for a different
4193 architecture in addition to those for the main target architecture.
4194 See the "Target Description Format" section in the user manual for
4197 * Multi-architecture debugging.
4199 GDB now includes general supports for debugging applications on
4200 hybrid systems that use more than one single processor architecture
4201 at the same time. Each such hybrid architecture still requires
4202 specific support to be added. The only hybrid architecture supported
4203 in this version of GDB is the Cell Broadband Engine.
4205 * GDB now supports integrated debugging of Cell/B.E. applications that
4206 use both the PPU and SPU architectures. To enable support for hybrid
4207 Cell/B.E. debugging, you need to configure GDB to support both the
4208 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4209 --enable-targets configure option.
4211 * Non-stop mode debugging.
4213 For some targets, GDB now supports an optional mode of operation in
4214 which you can examine stopped threads while other threads continue
4215 to execute freely. This is referred to as non-stop mode, with the
4216 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4217 section in the user manual for more information.
4219 To be able to support remote non-stop debugging, a remote stub needs
4220 to implement the non-stop mode remote protocol extensions, as
4221 described in the "Remote Non-Stop" section of the user manual. The
4222 GDB remote stub, gdbserver, has been adjusted to support these
4223 extensions on linux targets.
4225 * New commands (for set/show, see "New options" below)
4227 catch syscall [NAME(S) | NUMBER(S)]
4228 Catch system calls. Arguments, which should be names of system
4229 calls or their numbers, mean catch only those syscalls. Without
4230 arguments, every syscall will be caught. When the inferior issues
4231 any of the specified syscalls, GDB will stop and announce the system
4232 call, both when it is called and when its call returns. This
4233 feature is currently available with a native GDB running on the
4234 Linux Kernel, under the following architectures: x86, x86_64,
4235 PowerPC and PowerPC64.
4237 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4239 Search memory for a sequence of bytes.
4241 maint set python print-stack
4242 maint show python print-stack
4243 Show a stack trace when an error is encountered in a Python script.
4246 Invoke CODE by passing it to the Python interpreter.
4251 These allow macros to be defined, undefined, and listed
4255 Show operating system information about processes.
4258 List the inferiors currently under GDB's control.
4261 Switch focus to inferior number NUM.
4264 Detach from inferior number NUM.
4267 Kill inferior number NUM.
4271 set spu stop-on-load
4272 show spu stop-on-load
4273 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4275 set spu auto-flush-cache
4276 show spu auto-flush-cache
4277 Control whether to automatically flush the software-managed cache
4278 during Cell/B.E. debugging.
4280 set sh calling-convention
4281 show sh calling-convention
4282 Control the calling convention used when calling SH target functions.
4285 show debug timestamp
4286 Control display of timestamps with GDB debugging output.
4288 set disassemble-next-line
4289 show disassemble-next-line
4290 Control display of disassembled source lines or instructions when
4293 set remote noack-packet
4294 show remote noack-packet
4295 Set/show the use of remote protocol QStartNoAckMode packet. See above
4296 under "New remote packets."
4298 set remote query-attached-packet
4299 show remote query-attached-packet
4300 Control use of remote protocol `qAttached' (query-attached) packet.
4302 set remote read-siginfo-object
4303 show remote read-siginfo-object
4304 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4307 set remote write-siginfo-object
4308 show remote write-siginfo-object
4309 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4312 set remote reverse-continue
4313 show remote reverse-continue
4314 Control use of remote protocol 'bc' (reverse-continue) packet.
4316 set remote reverse-step
4317 show remote reverse-step
4318 Control use of remote protocol 'bs' (reverse-step) packet.
4320 set displaced-stepping
4321 show displaced-stepping
4322 Control displaced stepping mode. Displaced stepping is a way to
4323 single-step over breakpoints without removing them from the debuggee.
4324 Also known as "out-of-line single-stepping".
4327 show debug displaced
4328 Control display of debugging info for displaced stepping.
4330 maint set internal-error
4331 maint show internal-error
4332 Control what GDB does when an internal error is detected.
4334 maint set internal-warning
4335 maint show internal-warning
4336 Control what GDB does when an internal warning is detected.
4341 Use a wrapper program to launch programs for debugging.
4343 set multiple-symbols (all|ask|cancel)
4344 show multiple-symbols
4345 The value of this variable can be changed to adjust the debugger behavior
4346 when an expression or a breakpoint location contains an ambiguous symbol
4347 name (an overloaded function name, for instance).
4349 set breakpoint always-inserted
4350 show breakpoint always-inserted
4351 Keep breakpoints always inserted in the target, as opposed to inserting
4352 them when resuming the target, and removing them when the target stops.
4353 This option can improve debugger performance on slow remote targets.
4355 set arm fallback-mode (arm|thumb|auto)
4356 show arm fallback-mode
4357 set arm force-mode (arm|thumb|auto)
4359 These commands control how ARM GDB determines whether instructions
4360 are ARM or Thumb. The default for both settings is auto, which uses
4361 the current CPSR value for instructions without symbols; previous
4362 versions of GDB behaved as if "set arm fallback-mode arm".
4364 set disable-randomization
4365 show disable-randomization
4366 Standalone programs run with the virtual address space randomization enabled
4367 by default on some platforms. This option keeps the addresses stable across
4368 multiple debugging sessions.
4372 Control whether other threads are stopped or not when some thread hits
4377 Requests that asynchronous execution is enabled in the target, if available.
4378 In this case, it's possible to resume target in the background, and interact
4379 with GDB while the target is running. "show target-async" displays the
4380 current state of asynchronous execution of the target.
4382 set target-wide-charset
4383 show target-wide-charset
4384 The target-wide-charset is the name of the character set that GDB
4385 uses when printing characters whose type is wchar_t.
4387 set tcp auto-retry (on|off)
4389 set tcp connect-timeout
4390 show tcp connect-timeout
4391 These commands allow GDB to retry failed TCP connections to a remote stub
4392 with a specified timeout period; this is useful if the stub is launched
4393 in parallel with GDB but may not be ready to accept connections immediately.
4395 set libthread-db-search-path
4396 show libthread-db-search-path
4397 Control list of directories which GDB will search for appropriate
4400 set schedule-multiple (on|off)
4401 show schedule-multiple
4402 Allow GDB to resume all threads of all processes or only threads of
4403 the current process.
4407 Use more aggressive caching for accesses to the stack. This improves
4408 performance of remote debugging (particularly backtraces) without
4409 affecting correctness.
4411 set interactive-mode (on|off|auto)
4412 show interactive-mode
4413 Control whether GDB runs in interactive mode (on) or not (off).
4414 When in interactive mode, GDB waits for the user to answer all
4415 queries. Otherwise, GDB does not wait and assumes the default
4416 answer. When set to auto (the default), GDB determines which
4417 mode to use based on the stdin settings.
4422 For program forks, this is replaced by the new more generic `info
4423 inferiors' command. To list checkpoints, you can still use the
4424 `info checkpoints' command, which was an alias for the `info forks'
4428 Replaced by the new `inferior' command. To switch between
4429 checkpoints, you can still use the `restart' command, which was an
4430 alias for the `fork' command.
4433 This is removed, since some targets don't have a notion of
4434 processes. To switch between processes, you can still use the
4435 `inferior' command using GDB's own inferior number.
4438 For program forks, this is replaced by the new more generic `kill
4439 inferior' command. To delete a checkpoint, you can still use the
4440 `delete checkpoint' command, which was an alias for the `delete
4444 For program forks, this is replaced by the new more generic `detach
4445 inferior' command. To detach a checkpoint, you can still use the
4446 `detach checkpoint' command, which was an alias for the `detach
4449 * New native configurations
4451 x86/x86_64 Darwin i[34567]86-*-darwin*
4453 x86_64 MinGW x86_64-*-mingw*
4457 Lattice Mico32 lm32-*
4458 x86 DICOS i[34567]86-*-dicos*
4459 x86_64 DICOS x86_64-*-dicos*
4462 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4463 (mingw32ce) debugging.
4469 These commands were actually not implemented on any target.
4471 *** Changes in GDB 6.8
4473 * New native configurations
4475 NetBSD/hppa hppa*-*netbsd*
4476 Xtensa GNU/Linux xtensa*-*-linux*
4480 NetBSD/hppa hppa*-*-netbsd*
4481 Xtensa GNU/Lunux xtensa*-*-linux*
4483 * Change in command line behavior -- corefiles vs. process ids.
4485 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4486 attaching to process NUMBER fails, GDB no longer attempts to open a
4487 core file named NUMBER. Attaching to a program using the -c option
4488 is no longer supported. Instead, use the '-p' or '--pid' options.
4490 * GDB can now be built as a native debugger for debugging Windows x86
4491 (mingw32) Portable Executable (PE) programs.
4493 * Pending breakpoints no longer change their number when their address
4496 * GDB now supports breakpoints with multiple locations,
4497 including breakpoints on C++ constructors, inside C++ templates,
4498 and in inlined functions.
4500 * GDB's ability to debug optimized code has been improved. GDB more
4501 accurately identifies function bodies and lexical blocks that occupy
4502 more than one contiguous range of addresses.
4504 * Target descriptions can now describe registers for PowerPC.
4506 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4507 registers on PowerPC targets.
4509 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4510 targets even when the libthread_db library is not available.
4512 * The GDB remote stub, gdbserver, now supports the new file transfer
4513 commands (remote put, remote get, and remote delete).
4515 * The GDB remote stub, gdbserver, now supports run and attach in
4516 extended-remote mode.
4518 * hppa*64*-*-hpux11* target broken
4519 The debugger is unable to start a program and fails with the following
4520 error: "Error trying to get information about dynamic linker".
4521 The gdb-6.7 release is also affected.
4523 * GDB now supports the --enable-targets= configure option to allow
4524 building a single GDB executable that supports multiple remote
4525 target architectures.
4527 * GDB now supports debugging C and C++ programs which use the
4528 Decimal Floating Point extension. In addition, the PowerPC target
4529 now has a set of pseudo-registers to inspect decimal float values
4530 stored in two consecutive float registers.
4532 * The -break-insert MI command can optionally create pending
4535 * Improved support for debugging Ada
4536 Many improvements to the Ada language support have been made. These
4538 - Better support for Ada2005 interface types
4539 - Improved handling of arrays and slices in general
4540 - Better support for Taft-amendment types
4541 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4543 - Improved command completion in Ada
4546 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4551 set print frame-arguments (all|scalars|none)
4552 show print frame-arguments
4553 The value of this variable can be changed to control which argument
4554 values should be printed by the debugger when displaying a frame.
4559 Transfer files to and from a remote target, and delete remote files.
4566 Transfer files to and from a remote target, and delete remote files.
4568 * New remote packets
4575 Open, close, read, write, and delete files on the remote system.
4578 Attach to an existing process on the remote system, in extended-remote
4582 Run a new process on the remote system, in extended-remote mode.
4584 *** Changes in GDB 6.7
4586 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4587 bfd, libiberty and opcodes, as revealed by static analysis donated by
4588 Coverity, Inc. (http://scan.coverity.com).
4590 * When looking up multiply-defined global symbols, GDB will now prefer the
4591 symbol definition in the current shared library if it was built using the
4592 -Bsymbolic linker option.
4594 * When the Text User Interface (TUI) is not configured, GDB will now
4595 recognize the -tui command-line option and print a message that the TUI
4598 * The GDB remote stub, gdbserver, now has lower overhead for high
4599 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4601 * GDB for MIPS targets now autodetects whether a remote target provides
4602 32-bit or 64-bit register values.
4604 * Support for C++ member pointers has been improved.
4606 * GDB now understands XML target descriptions, which specify the
4607 target's overall architecture. GDB can read a description from
4608 a local file or over the remote serial protocol.
4610 * Vectors of single-byte data use a new integer type which is not
4611 automatically displayed as character or string data.
4613 * The /s format now works with the print command. It displays
4614 arrays of single-byte integers and pointers to single-byte integers
4617 * Target descriptions can now describe target-specific registers,
4618 for architectures which have implemented the support (currently
4619 only ARM, M68K, and MIPS).
4621 * GDB and the GDB remote stub, gdbserver, now support the XScale
4624 * The GDB remote stub, gdbserver, has been updated to support
4625 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4626 has been rewritten to use the standard GDB remote protocol.
4628 * GDB can now step into C++ functions which are called through thunks.
4630 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4632 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4633 layout. It also supports a TextSeg= and DataSeg= response when only
4634 segment base addresses (rather than offsets) are available.
4636 * The /i format now outputs any trailing branch delay slot instructions
4637 immediately following the last instruction within the count specified.
4639 * The GDB remote protocol "T" stop reply packet now supports a
4640 "library" response. Combined with the new "qXfer:libraries:read"
4641 packet, this response allows GDB to debug shared libraries on targets
4642 where the operating system manages the list of loaded libraries (e.g.
4643 Windows and SymbianOS).
4645 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4646 (DLLs) on Windows and Windows CE targets.
4648 * GDB now supports a faster verification that a .debug file matches its binary
4649 according to its build-id signature, if the signature is present.
4655 Enable or disable hardware flow control (RTS/CTS) on the serial port
4656 when debugging using remote targets.
4658 set mem inaccessible-by-default
4659 show mem inaccessible-by-default
4660 If the target supplies a memory map, for instance via the remote
4661 protocol's "qXfer:memory-map:read" packet, setting this variable
4662 prevents GDB from accessing memory outside the memory map. This
4663 is useful for targets with memory mapped registers or which react
4664 badly to accesses of unmapped address space.
4666 set breakpoint auto-hw
4667 show breakpoint auto-hw
4668 If the target supplies a memory map, for instance via the remote
4669 protocol's "qXfer:memory-map:read" packet, setting this variable
4670 lets GDB use hardware breakpoints automatically for memory regions
4671 where it can not use software breakpoints. This covers both the
4672 "break" command and internal breakpoints used for other commands
4673 including "next" and "finish".
4676 catch exception unhandled
4677 Stop the program execution when Ada exceptions are raised.
4680 Stop the program execution when an Ada assertion failed.
4684 Set an alternate system root for target files. This is a more
4685 general version of "set solib-absolute-prefix", which is now
4686 an alias to "set sysroot".
4689 Provide extended SPU facility status information. This set of
4690 commands is available only when debugging the Cell/B.E. SPU
4693 * New native configurations
4695 OpenBSD/sh sh*-*openbsd*
4698 unset tdesc filename
4700 Use the specified local file as an XML target description, and do
4701 not query the target for its built-in description.
4705 OpenBSD/sh sh*-*-openbsd*
4706 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4707 Toshiba Media Processor mep-elf
4709 * New remote packets
4712 Ignore the specified signals; pass them directly to the debugged program
4713 without stopping other threads or reporting them to GDB.
4715 qXfer:features:read:
4716 Read an XML target description from the target, which describes its
4721 Read or write contents of an spufs file on the target system. These
4722 packets are available only on the Cell/B.E. SPU architecture.
4724 qXfer:libraries:read:
4725 Report the loaded shared libraries. Combined with new "T" packet
4726 response, this packet allows GDB to debug shared libraries on
4727 targets where the operating system manages the list of loaded
4728 libraries (e.g. Windows and SymbianOS).
4732 Support for these obsolete configurations has been removed.
4740 i[34567]86-*-lynxos*
4741 i[34567]86-*-netware*
4742 i[34567]86-*-sco3.2v5*
4743 i[34567]86-*-sco3.2v4*
4745 i[34567]86-*-sysv4.2*
4748 i[34567]86-*-unixware2*
4749 i[34567]86-*-unixware*
4758 * Other removed features
4765 Various m68k-only ROM monitors.
4772 Various Renesas ROM monitors and debugging interfaces for SH and
4777 Support for a Macraigor serial interface to on-chip debugging.
4778 GDB does not directly support the newer parallel or USB
4783 A debug information format. The predecessor to DWARF 2 and
4784 DWARF 3, which are still supported.
4786 Support for the HP aCC compiler on HP-UX/PA-RISC
4788 SOM-encapsulated symbolic debugging information, automatic
4789 invocation of pxdb, and the aCC custom C++ ABI. This does not
4790 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4791 with aCC can still be debugged on an assembly level.
4793 MIPS ".pdr" sections
4795 A MIPS-specific format used to describe stack frame layout
4796 in debugging information.
4800 GDB could work with an older version of Guile to debug
4801 the interpreter and Scheme programs running in it.
4803 set mips stack-arg-size
4804 set mips saved-gpreg-size
4806 Use "set mips abi" to control parameter passing for MIPS.
4808 *** Changes in GDB 6.6
4813 Cell Broadband Engine SPU spu-elf
4815 * GDB can now be configured as a cross-debugger targeting native Windows
4816 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4817 running on a Windows system over TCP/IP to debug Windows programs.
4819 * The GDB remote stub, gdbserver, has been updated to support Windows and
4820 Cygwin debugging. Both single-threaded and multi-threaded programs are
4823 * The "set trust-readonly-sections" command works again. This command was
4824 broken in GDB 6.3, 6.4, and 6.5.
4826 * The "load" command now supports writing to flash memory, if the remote
4827 stub provides the required support.
4829 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4830 longer requires symbolic debug information (e.g. DWARF-2).
4835 unset substitute-path
4836 show substitute-path
4837 Manage a list of substitution rules that GDB uses to rewrite the name
4838 of the directories where the sources are located. This can be useful
4839 for instance when the sources were moved to a different location
4840 between compilation and debugging.
4844 Print each CLI command as it is executed. Each command is prefixed with
4845 a number of `+' symbols representing the nesting depth.
4846 The source command now has a `-v' option to enable the same feature.
4850 The ARM Demon monitor support (RDP protocol, "target rdp").
4852 Kernel Object Display, an embedded debugging feature which only worked with
4853 an obsolete version of Cisco IOS.
4855 The 'set download-write-size' and 'show download-write-size' commands.
4857 * New remote packets
4860 Tell a stub about GDB client features, and request remote target features.
4861 The first feature implemented is PacketSize, which allows the target to
4862 specify the size of packets it can handle - to minimize the number of
4863 packets required and improve performance when connected to a remote
4867 Fetch an OS auxilliary vector from the remote stub. This packet is a
4868 more efficient replacement for qPart:auxv:read.
4870 qXfer:memory-map:read:
4871 Fetch a memory map from the remote stub, including information about
4872 RAM, ROM, and flash memory devices.
4877 Erase and program a flash memory device.
4879 * Removed remote packets
4882 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4883 used it, and only gdbserver implemented it.
4885 *** Changes in GDB 6.5
4889 Renesas M32C/M16C m32c-elf
4891 Morpho Technologies ms1 ms1-elf
4895 init-if-undefined Initialize a convenience variable, but
4896 only if it doesn't already have a value.
4898 The following commands are presently only implemented for native GNU/Linux:
4900 checkpoint Save a snapshot of the program state.
4902 restart <n> Return the program state to a
4903 previously saved state.
4905 info checkpoints List currently saved checkpoints.
4907 delete-checkpoint <n> Delete a previously saved checkpoint.
4909 set|show detach-on-fork Tell gdb whether to detach from a newly
4910 forked process, or to keep debugging it.
4912 info forks List forks of the user program that
4913 are available to be debugged.
4915 fork <n> Switch to debugging one of several
4916 forks of the user program that are
4917 available to be debugged.
4919 delete-fork <n> Delete a fork from the list of forks
4920 that are available to be debugged (and
4921 kill the forked process).
4923 detach-fork <n> Delete a fork from the list of forks
4924 that are available to be debugged (and
4925 allow the process to continue).
4929 Morpho Technologies ms2 ms1-elf
4931 * Improved Windows host support
4933 GDB now builds as a cross debugger hosted on i686-mingw32, including
4934 native console support, and remote communications using either
4935 network sockets or serial ports.
4937 * Improved Modula-2 language support
4939 GDB can now print most types in the Modula-2 syntax. This includes:
4940 basic types, set types, record types, enumerated types, range types,
4941 pointer types and ARRAY types. Procedure var parameters are correctly
4942 printed and hexadecimal addresses and character constants are also
4943 written in the Modula-2 syntax. Best results can be obtained by using
4944 GNU Modula-2 together with the -gdwarf-2 command line option.
4948 The ARM rdi-share module.
4950 The Netware NLM debug server.
4952 *** Changes in GDB 6.4
4954 * New native configurations
4956 OpenBSD/arm arm*-*-openbsd*
4957 OpenBSD/mips64 mips64-*-openbsd*
4961 Morpho Technologies ms1 ms1-elf
4963 * New command line options
4965 --batch-silent As for --batch, but totally silent.
4966 --return-child-result The debugger will exist with the same value
4967 the child (debugged) program exited with.
4968 --eval-command COMMAND, -ex COMMAND
4969 Execute a single GDB CLI command. This may be
4970 specified multiple times and in conjunction
4971 with the --command (-x) option.
4973 * Deprecated commands removed
4975 The following commands, that were deprecated in 2000, have been
4979 set|show arm disassembly-flavor set|show arm disassembler
4980 othernames set arm disassembler
4981 set|show remotedebug set|show debug remote
4982 set|show archdebug set|show debug arch
4983 set|show eventdebug set|show debug event
4986 * New BSD user-level threads support
4988 It is now possible to debug programs using the user-level threads
4989 library on OpenBSD and FreeBSD. Currently supported (target)
4992 FreeBSD/amd64 x86_64-*-freebsd*
4993 FreeBSD/i386 i386-*-freebsd*
4994 OpenBSD/i386 i386-*-openbsd*
4996 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4997 are not yet supported.
4999 * New support for Matsushita MN10300 w/sim added
5000 (Work in progress). mn10300-elf.
5002 * REMOVED configurations and files
5004 VxWorks and the XDR protocol *-*-vxworks
5005 Motorola MCORE mcore-*-*
5006 National Semiconductor NS32000 ns32k-*-*
5008 * New "set print array-indexes" command
5010 After turning this setting "on", GDB prints the index of each element
5011 when displaying arrays. The default is "off" to preserve the previous
5014 * VAX floating point support
5016 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5018 * User-defined command support
5020 In addition to using $arg0..$arg9 for argument passing, it is now possible
5021 to use $argc to determine now many arguments have been passed. See the
5022 section on user-defined commands in the user manual for more information.
5024 *** Changes in GDB 6.3:
5026 * New command line option
5028 GDB now accepts -l followed by a number to set the timeout for remote
5031 * GDB works with GCC -feliminate-dwarf2-dups
5033 GDB now supports a more compact representation of DWARF-2 debug
5034 information using DW_FORM_ref_addr references. These are produced
5035 by GCC with the option -feliminate-dwarf2-dups and also by some
5036 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5037 to use -feliminate-dwarf2-dups.
5039 * Internationalization
5041 When supported by the host system, GDB will be built with
5042 internationalization (libintl). The task of marking up the sources is
5043 continued, we're looking forward to our first translation.
5047 Initial support for debugging programs compiled with the GNAT
5048 implementation of the Ada programming language has been integrated
5049 into GDB. In this release, support is limited to expression evaluation.
5051 * New native configurations
5053 GNU/Linux/m32r m32r-*-linux-gnu
5057 GDB's remote protocol now includes support for the 'p' packet. This
5058 packet is used to fetch individual registers from a remote inferior.
5060 * END-OF-LIFE registers[] compatibility module
5062 GDB's internal register infrastructure has been completely rewritten.
5063 The new infrastructure making possible the implementation of key new
5064 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5067 GDB 6.3 will be the last release to include the the registers[]
5068 compatibility module that allowed out-of-date configurations to
5069 continue to work. This change directly impacts the following
5079 powerpc bdm protocol
5081 Unless there is activity to revive these configurations, they will be
5082 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5084 * OBSOLETE configurations and files
5086 Configurations that have been declared obsolete in this release have
5087 been commented out. Unless there is activity to revive these
5088 configurations, the next release of GDB will have their sources
5089 permanently REMOVED.
5098 *** Changes in GDB 6.2.1:
5100 * MIPS `break main; run' gave an heuristic-fence-post warning
5102 When attempting to run even a simple program, a warning about
5103 heuristic-fence-post being hit would be reported. This problem has
5106 * MIPS IRIX 'long double' crashed GDB
5108 When examining a long double variable, GDB would get a segmentation
5109 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5110 IRIX long double values).
5114 A bug in the VAX stack code was causing problems with the "next"
5115 command. This problem has been fixed.
5117 *** Changes in GDB 6.2:
5119 * Fix for ``many threads''
5121 On GNU/Linux systems that use the NPTL threads library, a program
5122 rapidly creating and deleting threads would confuse GDB leading to the
5125 ptrace: No such process.
5126 thread_db_get_info: cannot get thread info: generic error
5128 This problem has been fixed.
5130 * "-async" and "-noasync" options removed.
5132 Support for the broken "-noasync" option has been removed (it caused
5135 * New ``start'' command.
5137 This command runs the program until the begining of the main procedure.
5139 * New BSD Kernel Data Access Library (libkvm) interface
5141 Using ``target kvm'' it is now possible to debug kernel core dumps and
5142 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5143 platforms. Currently supported (native-only) configurations are:
5145 FreeBSD/amd64 x86_64-*-freebsd*
5146 FreeBSD/i386 i?86-*-freebsd*
5147 NetBSD/i386 i?86-*-netbsd*
5148 NetBSD/m68k m68*-*-netbsd*
5149 NetBSD/sparc sparc-*-netbsd*
5150 OpenBSD/amd64 x86_64-*-openbsd*
5151 OpenBSD/i386 i?86-*-openbsd*
5152 OpenBSD/m68k m68*-openbsd*
5153 OpenBSD/sparc sparc-*-openbsd*
5155 * Signal trampoline code overhauled
5157 Many generic problems with GDB's signal handling code have been fixed.
5158 These include: backtraces through non-contiguous stacks; recognition
5159 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5160 call; backtrace through a signal trampoline; step into and out of
5161 signal handlers; and single-stepping in the signal trampoline.
5163 Please note that kernel bugs are a limiting factor here. These
5164 features have been shown to work on an s390 GNU/Linux system that
5165 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5167 * Cygwin support for DWARF 2 added.
5169 * New native configurations
5171 GNU/Linux/hppa hppa*-*-linux*
5172 OpenBSD/hppa hppa*-*-openbsd*
5173 OpenBSD/m68k m68*-*-openbsd*
5174 OpenBSD/m88k m88*-*-openbsd*
5175 OpenBSD/powerpc powerpc-*-openbsd*
5176 NetBSD/vax vax-*-netbsd*
5177 OpenBSD/vax vax-*-openbsd*
5179 * END-OF-LIFE frame compatibility module
5181 GDB's internal frame infrastructure has been completely rewritten.
5182 The new infrastructure making it possible to support key new features
5183 including DWARF 2 Call Frame Information. To aid in the task of
5184 migrating old configurations to this new infrastructure, a
5185 compatibility module, that allowed old configurations to continue to
5186 work, was also included.
5188 GDB 6.2 will be the last release to include this frame compatibility
5189 module. This change directly impacts the following configurations:
5199 Unless there is activity to revive these configurations, they will be
5200 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5202 * REMOVED configurations and files
5204 Sun 3, running SunOS 3 m68*-*-sunos3*
5205 Sun 3, running SunOS 4 m68*-*-sunos4*
5206 Sun 2, running SunOS 3 m68000-*-sunos3*
5207 Sun 2, running SunOS 4 m68000-*-sunos4*
5208 Motorola 680x0 running LynxOS m68*-*-lynxos*
5209 AT&T 3b1/Unix pc m68*-att-*
5210 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5211 decstation mips-dec-* mips-little-*
5212 riscos mips-*-riscos* mips-*-sysv*
5213 sonymips mips-sony-*
5214 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5216 *** Changes in GDB 6.1.1:
5218 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5220 The TUI (Text-mode User Interface) is now built as part of a default
5221 GDB configuration. It is enabled by either selecting the TUI with the
5222 command line option "-i=tui" or by running the separate "gdbtui"
5223 program. For more information on the TUI, see the manual "Debugging
5226 * Pending breakpoint support (also included in GDB 6.1)
5228 Support has been added to allow you to specify breakpoints in shared
5229 libraries that have not yet been loaded. If a breakpoint location
5230 cannot be found, and the "breakpoint pending" option is set to auto,
5231 GDB queries you if you wish to make the breakpoint pending on a future
5232 shared-library load. If and when GDB resolves the breakpoint symbol,
5233 the pending breakpoint is removed as one or more regular breakpoints
5236 Pending breakpoints are very useful for GCJ Java debugging.
5238 * Fixed ISO-C build problems
5240 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5241 non ISO-C code that stopped them being built using a more strict ISO-C
5242 compiler (e.g., IBM's C compiler).
5244 * Fixed build problem on IRIX 5
5246 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5247 wasn't able to compile compile on an IRIX 5 system.
5249 * Added execute permission to gdb/gdbserver/configure
5251 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5252 permission. This bug would cause configure to fail on a number of
5253 systems (Solaris, IRIX). Ref: server/519.
5255 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5257 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5258 has been updated to use constant array sizes.
5260 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5262 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5263 its generated DWARF Call Frame Info. This encoding was causing GDB to
5264 panic, that panic has been fixed. Ref: gdb/1628.
5266 * Fixed a problem when examining parameters in shared library code.
5268 When examining parameters in optimized shared library code generated
5269 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5270 not available''. GDB now correctly displays the variable's value.
5272 *** Changes in GDB 6.1:
5274 * Removed --with-mmalloc
5276 Support for the mmalloc memory manager has been removed, as it
5277 conflicted with the internal gdb byte cache.
5279 * Changes in AMD64 configurations
5281 The AMD64 target now includes the %cs and %ss registers. As a result
5282 the AMD64 remote protocol has changed; this affects the floating-point
5283 and SSE registers. If you rely on those registers for your debugging,
5284 you should upgrade gdbserver on the remote side.
5286 * Revised SPARC target
5288 The SPARC target has been completely revised, incorporating the
5289 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5290 support for LynxOS and SunOS 4 has been dropped. Calling functions
5291 from within GDB on operating systems with a non-executable stack
5292 (Solaris, OpenBSD) now works.
5296 GDB has a new C++ demangler which does a better job on the mangled
5297 names generated by current versions of g++. It also runs faster, so
5298 with this and other changes gdb should now start faster on large C++
5301 * DWARF 2 Location Expressions
5303 GDB support for location expressions has been extended to support function
5304 arguments and frame bases. Older versions of GDB could crash when they
5307 * C++ nested types and namespaces
5309 GDB's support for nested types and namespaces in C++ has been
5310 improved, especially if you use the DWARF 2 debugging format. (This
5311 is the default for recent versions of GCC on most platforms.)
5312 Specifically, if you have a class "Inner" defined within a class or
5313 namespace "Outer", then GDB realizes that the class's name is
5314 "Outer::Inner", not simply "Inner". This should greatly reduce the
5315 frequency of complaints about not finding RTTI symbols. In addition,
5316 if you are stopped at inside of a function defined within a namespace,
5317 GDB modifies its name lookup accordingly.
5319 * New native configurations
5321 NetBSD/amd64 x86_64-*-netbsd*
5322 OpenBSD/amd64 x86_64-*-openbsd*
5323 OpenBSD/alpha alpha*-*-openbsd*
5324 OpenBSD/sparc sparc-*-openbsd*
5325 OpenBSD/sparc64 sparc64-*-openbsd*
5327 * New debugging protocols
5329 M32R with SDI protocol m32r-*-elf*
5331 * "set prompt-escape-char" command deleted.
5333 The command "set prompt-escape-char" has been deleted. This command,
5334 and its very obscure effet on GDB's prompt, was never documented,
5335 tested, nor mentioned in the NEWS file.
5337 * OBSOLETE configurations and files
5339 Configurations that have been declared obsolete in this release have
5340 been commented out. Unless there is activity to revive these
5341 configurations, the next release of GDB will have their sources
5342 permanently REMOVED.
5344 Sun 3, running SunOS 3 m68*-*-sunos3*
5345 Sun 3, running SunOS 4 m68*-*-sunos4*
5346 Sun 2, running SunOS 3 m68000-*-sunos3*
5347 Sun 2, running SunOS 4 m68000-*-sunos4*
5348 Motorola 680x0 running LynxOS m68*-*-lynxos*
5349 AT&T 3b1/Unix pc m68*-att-*
5350 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5351 decstation mips-dec-* mips-little-*
5352 riscos mips-*-riscos* mips-*-sysv*
5353 sonymips mips-sony-*
5354 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5356 * REMOVED configurations and files
5358 SGI Irix-4.x mips-sgi-irix4 or iris4
5359 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5360 Z8000 simulator z8k-zilog-none or z8ksim
5361 Matsushita MN10200 w/simulator mn10200-*-*
5362 H8/500 simulator h8500-hitachi-hms or h8500hms
5363 HP/PA running BSD hppa*-*-bsd*
5364 HP/PA running OSF/1 hppa*-*-osf*
5365 HP/PA Pro target hppa*-*-pro*
5366 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5367 386BSD i[3456]86-*-bsd*
5368 Sequent family i[3456]86-sequent-sysv4*
5369 i[3456]86-sequent-sysv*
5370 i[3456]86-sequent-bsd*
5371 SPARC running LynxOS sparc-*-lynxos*
5372 SPARC running SunOS 4 sparc-*-sunos4*
5373 Tsqware Sparclet sparclet-*-*
5374 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5376 *** Changes in GDB 6.0:
5380 Support for debugging the Objective-C programming language has been
5381 integrated into GDB.
5383 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5385 DWARF 2's Call Frame Information makes available compiler generated
5386 information that more exactly describes the program's run-time stack.
5387 By using this information, GDB is able to provide more robust stack
5390 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5391 have been updated to use a new backtrace mechanism which includes
5392 DWARF 2 CFI support.
5396 GDB's remote protocol has been extended to include support for hosted
5397 file I/O (where the remote target uses GDB's file system). See GDB's
5398 remote protocol documentation for details.
5400 * All targets using the new architecture framework.
5402 All of GDB's targets have been updated to use the new internal
5403 architecture framework. The way is now open for future GDB releases
5404 to include cross-architecture native debugging support (i386 on amd64,
5407 * GNU/Linux's Thread Local Storage (TLS)
5409 GDB now includes support for for the GNU/Linux implementation of
5410 per-thread variables.
5412 * GNU/Linux's Native POSIX Thread Library (NPTL)
5414 GDB's thread code has been updated to work with either the new
5415 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5417 * Separate debug info.
5419 GDB, in conjunction with BINUTILS, now supports a mechanism for
5420 automatically loading debug information from a separate file. Instead
5421 of shipping full debug and non-debug versions of system libraries,
5422 system integrators can now instead ship just the stripped libraries
5423 and optional debug files.
5425 * DWARF 2 Location Expressions
5427 DWARF 2 Location Expressions allow the compiler to more completely
5428 describe the location of variables (even in optimized code) to the
5431 GDB now includes preliminary support for location expressions (support
5432 for DW_OP_piece is still missing).
5436 A number of long standing bugs that caused GDB to die while starting a
5437 Java application have been fixed. GDB's Java support is now
5438 considered "useable".
5440 * GNU/Linux support for fork, vfork, and exec.
5442 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5443 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5446 * GDB supports logging output to a file
5448 There are two new commands, "set logging" and "show logging", which can be
5449 used to capture GDB's output to a file.
5451 * The meaning of "detach" has changed for gdbserver
5453 The "detach" command will now resume the application, as documented. To
5454 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5457 * d10v, m68hc11 `regs' command deprecated
5459 The `info registers' command has been updated so that it displays the
5460 registers using a format identical to the old `regs' command.
5464 A new command, "maint set profile on/off", has been added. This command can
5465 be used to enable or disable profiling while running GDB, to profile a
5466 session or a set of commands. In addition there is a new configure switch,
5467 "--enable-profiling", which will cause GDB to be compiled with profiling
5468 data, for more informative profiling results.
5470 * Default MI syntax changed to "mi2".
5472 The default MI (machine interface) syntax, enabled by the command line
5473 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5474 "mi1", can be enabled by specifying the option "-i=mi1".
5476 Support for the original "mi0" syntax (included in GDB 5.0) has been
5479 Fix for gdb/192: removed extraneous space when displaying frame level.
5480 Fix for gdb/672: update changelist is now output in mi list format.
5481 Fix for gdb/702: a -var-assign that updates the value now shows up
5482 in a subsequent -var-update.
5484 * New native configurations.
5486 FreeBSD/amd64 x86_64-*-freebsd*
5488 * Multi-arched targets.
5490 HP/PA HPUX11 hppa*-*-hpux*
5491 Renesas M32R/D w/simulator m32r-*-elf*
5493 * OBSOLETE configurations and files
5495 Configurations that have been declared obsolete in this release have
5496 been commented out. Unless there is activity to revive these
5497 configurations, the next release of GDB will have their sources
5498 permanently REMOVED.
5500 Z8000 simulator z8k-zilog-none or z8ksim
5501 Matsushita MN10200 w/simulator mn10200-*-*
5502 H8/500 simulator h8500-hitachi-hms or h8500hms
5503 HP/PA running BSD hppa*-*-bsd*
5504 HP/PA running OSF/1 hppa*-*-osf*
5505 HP/PA Pro target hppa*-*-pro*
5506 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5507 Sequent family i[3456]86-sequent-sysv4*
5508 i[3456]86-sequent-sysv*
5509 i[3456]86-sequent-bsd*
5510 Tsqware Sparclet sparclet-*-*
5511 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5513 * REMOVED configurations and files
5516 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5517 IBM AIX PS/2 i[3456]86-*-aix
5518 i386 running Mach 3.0 i[3456]86-*-mach3*
5519 i386 running Mach i[3456]86-*-mach*
5520 i386 running OSF/1 i[3456]86-*osf1mk*
5521 HP/Apollo 68k Family m68*-apollo*-sysv*,
5523 m68*-hp-bsd*, m68*-hp-hpux*
5524 Argonaut Risc Chip (ARC) arc-*-*
5525 Mitsubishi D30V d30v-*-*
5526 Fujitsu FR30 fr30-*-elf*
5527 OS/9000 i[34]86-*-os9k
5528 I960 with MON960 i960-*-coff
5530 * MIPS $fp behavior changed
5532 The convenience variable $fp, for the MIPS, now consistently returns
5533 the address of the current frame's base. Previously, depending on the
5534 context, $fp could refer to either $sp or the current frame's base
5535 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5536 The GNU Source-Level Debugger''.
5538 *** Changes in GDB 5.3:
5540 * GNU/Linux shared library multi-threaded performance improved.
5542 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5543 `/proc', in preference to `ptrace' for memory reads. This may result
5544 in an improvement in the start-up time of multi-threaded, shared
5545 library applications when run under GDB. One GDB user writes: ``loads
5546 shared libs like mad''.
5548 * ``gdbserver'' now supports multi-threaded applications on some targets
5550 Support for debugging multi-threaded applications which use
5551 the GNU/Linux LinuxThreads package has been added for
5552 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5553 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5555 * GDB now supports C/C++ preprocessor macros.
5557 GDB now expands preprocessor macro invocations in C/C++ expressions,
5558 and provides various commands for showing macro definitions and how
5561 The new command `macro expand EXPRESSION' expands any macro
5562 invocations in expression, and shows the result.
5564 The new command `show macro MACRO-NAME' shows the definition of the
5565 macro named MACRO-NAME, and where it was defined.
5567 Most compilers don't include information about macros in the debugging
5568 information by default. In GCC 3.1, for example, you need to compile
5569 your program with the options `-gdwarf-2 -g3'. If the macro
5570 information is present in the executable, GDB will read it.
5572 * Multi-arched targets.
5574 DEC Alpha (partial) alpha*-*-*
5575 DEC VAX (partial) vax-*-*
5577 National Semiconductor NS32000 (partial) ns32k-*-*
5578 Motorola 68000 (partial) m68k-*-*
5579 Motorola MCORE mcore-*-*
5583 Fujitsu FRV architecture added by Red Hat frv*-*-*
5586 * New native configurations
5588 Alpha NetBSD alpha*-*-netbsd*
5589 SH NetBSD sh*-*-netbsdelf*
5590 MIPS NetBSD mips*-*-netbsd*
5591 UltraSPARC NetBSD sparc64-*-netbsd*
5593 * OBSOLETE configurations and files
5595 Configurations that have been declared obsolete in this release have
5596 been commented out. Unless there is activity to revive these
5597 configurations, the next release of GDB will have their sources
5598 permanently REMOVED.
5600 Mitsubishi D30V d30v-*-*
5601 OS/9000 i[34]86-*-os9k
5602 IBM AIX PS/2 i[3456]86-*-aix
5603 Fujitsu FR30 fr30-*-elf*
5604 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5605 Argonaut Risc Chip (ARC) arc-*-*
5606 i386 running Mach 3.0 i[3456]86-*-mach3*
5607 i386 running Mach i[3456]86-*-mach*
5608 i386 running OSF/1 i[3456]86-*osf1mk*
5609 HP/Apollo 68k Family m68*-apollo*-sysv*,
5611 m68*-hp-bsd*, m68*-hp-hpux*
5612 I960 with MON960 i960-*-coff
5614 * OBSOLETE languages
5616 CHILL, a Pascal like language used by telecommunications companies.
5618 * REMOVED configurations and files
5620 AMD 29k family via UDI a29k-amd-udi, udi29k
5621 A29K VxWorks a29k-*-vxworks
5622 AMD 29000 embedded, using EBMON a29k-none-none
5623 AMD 29000 embedded with COFF a29k-none-coff
5624 AMD 29000 embedded with a.out a29k-none-aout
5626 testsuite/gdb.hp/gdb.threads-hp/ directory
5628 * New command "set max-user-call-depth <nnn>"
5630 This command allows the user to limit the call depth of user-defined
5631 commands. The default is 1024.
5633 * Changes in FreeBSD/i386 native debugging.
5635 Support for the "generate-core-file" has been added.
5637 * New commands "dump", "append", and "restore".
5639 These commands allow data to be copied from target memory
5640 to a bfd-format or binary file (dump and append), and back
5641 from a file into memory (restore).
5643 * Improved "next/step" support on multi-processor Alpha Tru64.
5645 The previous single-step mechanism could cause unpredictable problems,
5646 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5647 of a software single-step mechanism prevents this.
5649 *** Changes in GDB 5.2.1:
5657 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5658 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5659 Fix, by Joel Brobecker imported from mainline.
5661 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5662 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5663 Fix, by Fred Fish, imported from mainline.
5665 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5666 Surprisingly enough, it works now.
5667 By Michal Ludvig, imported from mainline.
5669 i386 hardware watchpoint support:
5670 avoid misses on second run for some targets.
5671 By Pierre Muller, imported from mainline.
5673 *** Changes in GDB 5.2:
5675 * New command "set trust-readonly-sections on[off]".
5677 This command is a hint that tells gdb that read-only sections
5678 really are read-only (ie. that their contents will not change).
5679 In this mode, gdb will go to the object file rather than the
5680 target to read memory from read-only sections (such as ".text").
5681 This can be a significant performance improvement on some
5682 (notably embedded) targets.
5684 * New command "generate-core-file" (or "gcore").
5686 This new gdb command allows the user to drop a core file of the child
5687 process state at any time. So far it's been implemented only for
5688 GNU/Linux and Solaris, but should be relatively easily ported to other
5689 hosts. Argument is core file name (defaults to core.<pid>).
5691 * New command line option
5693 GDB now accepts --pid or -p followed by a process id.
5695 * Change in command line behavior -- corefiles vs. process ids.
5697 There is a subtle behavior in the way in which GDB handles
5698 command line arguments. The first non-flag argument is always
5699 a program to debug, but the second non-flag argument may either
5700 be a corefile or a process id. Previously, GDB would attempt to
5701 open the second argument as a corefile, and if that failed, would
5702 issue a superfluous error message and then attempt to attach it as
5703 a process. Now, if the second argument begins with a non-digit,
5704 it will be treated as a corefile. If it begins with a digit,
5705 GDB will attempt to attach it as a process, and if no such process
5706 is found, will then attempt to open it as a corefile.
5708 * Changes in ARM configurations.
5710 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5711 configuration is fully multi-arch.
5713 * New native configurations
5715 ARM NetBSD arm*-*-netbsd*
5716 x86 OpenBSD i[3456]86-*-openbsd*
5717 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5718 Sparc64 running FreeBSD sparc64-*-freebsd*
5722 Sanyo XStormy16 xstormy16-elf
5724 * OBSOLETE configurations and files
5726 Configurations that have been declared obsolete in this release have
5727 been commented out. Unless there is activity to revive these
5728 configurations, the next release of GDB will have their sources
5729 permanently REMOVED.
5731 AMD 29k family via UDI a29k-amd-udi, udi29k
5732 A29K VxWorks a29k-*-vxworks
5733 AMD 29000 embedded, using EBMON a29k-none-none
5734 AMD 29000 embedded with COFF a29k-none-coff
5735 AMD 29000 embedded with a.out a29k-none-aout
5737 testsuite/gdb.hp/gdb.threads-hp/ directory
5739 * REMOVED configurations and files
5741 TI TMS320C80 tic80-*-*
5743 PowerPC Solaris powerpcle-*-solaris*
5744 PowerPC Windows NT powerpcle-*-cygwin32
5745 PowerPC Netware powerpc-*-netware*
5746 Harris/CXUX m88k m88*-harris-cxux*
5747 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5748 ns32k-utek-sysv* ns32k-utek-*
5749 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5750 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5751 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5752 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5753 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5755 * Changes to command line processing
5757 The new `--args' feature can be used to specify command-line arguments
5758 for the inferior from gdb's command line.
5760 * Changes to key bindings
5762 There is a new `operate-and-get-next' function bound to `C-o'.
5764 *** Changes in GDB 5.1.1
5766 Fix compile problem on DJGPP.
5768 Fix a problem with floating-point registers on the i386 being
5771 Fix to stop GDB crashing on .debug_str debug info.
5773 Numerous documentation fixes.
5775 Numerous testsuite fixes.
5777 *** Changes in GDB 5.1:
5779 * New native configurations
5781 Alpha FreeBSD alpha*-*-freebsd*
5782 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5783 MIPS GNU/Linux mips*-*-linux*
5784 MIPS SGI Irix 6.x mips*-sgi-irix6*
5785 ia64 AIX ia64-*-aix*
5786 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5790 Motorola 68HC11 and 68HC12 m68hc11-elf
5792 UltraSparc running GNU/Linux sparc64-*-linux*
5794 * OBSOLETE configurations and files
5796 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5797 Harris/CXUX m88k m88*-harris-cxux*
5798 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5799 ns32k-utek-sysv* ns32k-utek-*
5800 TI TMS320C80 tic80-*-*
5802 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5803 PowerPC Solaris powerpcle-*-solaris*
5804 PowerPC Windows NT powerpcle-*-cygwin32
5805 PowerPC Netware powerpc-*-netware*
5806 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5807 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5808 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5809 Apple Macintosh (MPW) host N/A
5811 stuff.c (Program to stuff files into a specially prepared space in kdb)
5812 kdb-start.c (Main loop for the standalone kernel debugger)
5814 Configurations that have been declared obsolete in this release have
5815 been commented out. Unless there is activity to revive these
5816 configurations, the next release of GDB will have their sources
5817 permanently REMOVED.
5819 * REMOVED configurations and files
5821 Altos 3068 m68*-altos-*
5822 Convex c1-*-*, c2-*-*
5824 ARM RISCix arm-*-* (as host)
5828 * GDB has been converted to ISO C.
5830 GDB's source code has been converted to ISO C. In particular, the
5831 sources are fully protoized, and rely on standard headers being
5836 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5838 * The MI enabled by default.
5840 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5841 revised and enabled by default. Packages which use GDB as a debugging
5842 engine behind a UI or another front end are encouraged to switch to
5843 using the GDB/MI interface, instead of the old annotations interface
5844 which is now deprecated.
5846 * Support for debugging Pascal programs.
5848 GDB now includes support for debugging Pascal programs. The following
5849 main features are supported:
5851 - Pascal-specific data types such as sets;
5853 - automatic recognition of Pascal sources based on file-name
5856 - Pascal-style display of data types, variables, and functions;
5858 - a Pascal expression parser.
5860 However, some important features are not yet supported.
5862 - Pascal string operations are not supported at all;
5864 - there are some problems with boolean types;
5866 - Pascal type hexadecimal constants are not supported
5867 because they conflict with the internal variables format;
5869 - support for Pascal objects and classes is not full yet;
5871 - unlike Pascal, GDB is case-sensitive for symbol names.
5873 * Changes in completion.
5875 Commands such as `shell', `run' and `set args', which pass arguments
5876 to inferior programs, now complete on file names, similar to what
5877 users expect at the shell prompt.
5879 Commands which accept locations, such as `disassemble', `print',
5880 `breakpoint', `until', etc. now complete on filenames as well as
5881 program symbols. Thus, if you type "break foob TAB", and the source
5882 files linked into the programs include `foobar.c', that file name will
5883 be one of the candidates for completion. However, file names are not
5884 considered for completion after you typed a colon that delimits a file
5885 name from a name of a function in that file, as in "break foo.c:bar".
5887 `set demangle-style' completes on available demangling styles.
5889 * New platform-independent commands:
5891 It is now possible to define a post-hook for a command as well as a
5892 hook that runs before the command. For more details, see the
5893 documentation of `hookpost' in the GDB manual.
5895 * Changes in GNU/Linux native debugging.
5897 Support for debugging multi-threaded programs has been completely
5898 revised for all platforms except m68k and sparc. You can now debug as
5899 many threads as your system allows you to have.
5901 Attach/detach is supported for multi-threaded programs.
5903 Support for SSE registers was added for x86. This doesn't work for
5904 multi-threaded programs though.
5906 * Changes in MIPS configurations.
5908 Multi-arch support is enabled for all MIPS configurations.
5910 GDB can now be built as native debugger on SGI Irix 6.x systems for
5911 debugging n32 executables. (Debugging 64-bit executables is not yet
5914 * Unified support for hardware watchpoints in all x86 configurations.
5916 Most (if not all) native x86 configurations support hardware-assisted
5917 breakpoints and watchpoints in a unified manner. This support
5918 implements debug register sharing between watchpoints, which allows to
5919 put a virtually infinite number of watchpoints on the same address,
5920 and also supports watching regions up to 16 bytes with several debug
5923 The new maintenance command `maintenance show-debug-regs' toggles
5924 debugging print-outs in functions that insert, remove, and test
5925 watchpoints and hardware breakpoints.
5927 * Changes in the DJGPP native configuration.
5929 New command ``info dos sysinfo'' displays assorted information about
5930 the CPU, OS, memory, and DPMI server.
5932 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5933 display information about segment descriptors stored in GDT, LDT, and
5936 New commands ``info dos pde'' and ``info dos pte'' display entries
5937 from Page Directory and Page Tables (for now works with CWSDPMI only).
5938 New command ``info dos address-pte'' displays the Page Table entry for
5939 a given linear address.
5941 GDB can now pass command lines longer than 126 characters to the
5942 program being debugged (requires an update to the libdbg.a library
5943 which is part of the DJGPP development kit).
5945 DWARF2 debug info is now supported.
5947 It is now possible to `step' and `next' through calls to `longjmp'.
5949 * Changes in documentation.
5951 All GDB documentation was converted to GFDL, the GNU Free
5952 Documentation License.
5954 Tracepoints-related commands are now fully documented in the GDB
5957 TUI, the Text-mode User Interface, is now documented in the manual.
5959 Tracepoints-related commands are now fully documented in the GDB
5962 The "GDB Internals" manual now has an index. It also includes
5963 documentation of `ui_out' functions, GDB coding standards, x86
5964 hardware watchpoints, and memory region attributes.
5966 * GDB's version number moved to ``version.in''
5968 The Makefile variable VERSION has been replaced by the file
5969 ``version.in''. People creating GDB distributions should update the
5970 contents of this file.
5974 GUD support is now a standard part of the EMACS distribution.
5976 *** Changes in GDB 5.0:
5978 * Improved support for debugging FP programs on x86 targets
5980 Unified and much-improved support for debugging floating-point
5981 programs on all x86 targets. In particular, ``info float'' now
5982 displays the FP registers in the same format on all x86 targets, with
5983 greater level of detail.
5985 * Improvements and bugfixes in hardware-assisted watchpoints
5987 It is now possible to watch array elements, struct members, and
5988 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5989 on x86 targets no longer erroneously trigger when the address is
5992 * Improvements in the native DJGPP version of GDB
5994 The distribution now includes all the scripts and auxiliary files
5995 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5996 machines ``out of the box''.
5998 The DJGPP version can now debug programs that use signals. It is
5999 possible to catch signals that happened in the debuggee, deliver
6000 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6001 would kill the program being debugged.) Programs that hook hardware
6002 interrupts (keyboard, timer, etc.) can also be debugged.
6004 It is now possible to debug DJGPP programs that redirect their
6005 standard handles or switch them to raw (as opposed to cooked) mode, or
6006 even close them. The command ``run < foo > bar'' works as expected,
6007 and ``info terminal'' reports useful information about the debuggee's
6008 terminal, including raw/cooked mode, redirection, etc.
6010 The DJGPP version now uses termios functions for console I/O, which
6011 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6014 DOS-style file names with drive letters are now fully supported by
6017 It is now possible to debug DJGPP programs that switch their working
6018 directory. It is also possible to rerun the debuggee any number of
6019 times without restarting GDB; thus, you can use the same setup,
6020 breakpoints, etc. for many debugging sessions.
6022 * New native configurations
6024 ARM GNU/Linux arm*-*-linux*
6025 PowerPC GNU/Linux powerpc-*-linux*
6029 Motorola MCore mcore-*-*
6030 x86 VxWorks i[3456]86-*-vxworks*
6031 PowerPC VxWorks powerpc-*-vxworks*
6032 TI TMS320C80 tic80-*-*
6034 * OBSOLETE configurations
6036 Altos 3068 m68*-altos-*
6037 Convex c1-*-*, c2-*-*
6039 ARM RISCix arm-*-* (as host)
6042 Configurations that have been declared obsolete will be commented out,
6043 but the code will be left in place. If there is no activity to revive
6044 these configurations before the next release of GDB, the sources will
6045 be permanently REMOVED.
6047 * Gould support removed
6049 Support for the Gould PowerNode and NP1 has been removed.
6051 * New features for SVR4
6053 On SVR4 native platforms (such as Solaris), if you attach to a process
6054 without first loading a symbol file, GDB will now attempt to locate and
6055 load symbols from the running process's executable file.
6057 * Many C++ enhancements
6059 C++ support has been greatly improved. Overload resolution now works properly
6060 in almost all cases. RTTI support is on the way.
6062 * Remote targets can connect to a sub-program
6064 A popen(3) style serial-device has been added. This device starts a
6065 sub-process (such as a stand-alone simulator) and then communicates
6066 with that. The sub-program to run is specified using the syntax
6067 ``|<program> <args>'' vis:
6069 (gdb) set remotedebug 1
6070 (gdb) target extended-remote |mn10300-elf-sim program-args
6072 * MIPS 64 remote protocol
6074 A long standing bug in the mips64 remote protocol where by GDB
6075 expected certain 32 bit registers (ex SR) to be transfered as 32
6076 instead of 64 bits has been fixed.
6078 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6079 added to provide backward compatibility with older versions of GDB.
6081 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6083 The command ``set remotebinarydownload'' command has been replaced by
6084 ``set remote X-packet''. Other commands in ``set remote'' family
6085 include ``set remote P-packet''.
6087 * Breakpoint commands accept ranges.
6089 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6090 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6091 ``tracepoint passcount'' also accepts a range of tracepoints.
6093 * ``apropos'' command added.
6095 The ``apropos'' command searches through command names and
6096 documentation strings, printing out matches, making it much easier to
6097 try to find a command that does what you are looking for.
6101 A new machine oriented interface (MI) has been added to GDB. This
6102 interface is designed for debug environments running GDB as a separate
6103 process. This is part of the long term libGDB project. See the
6104 "GDB/MI" chapter of the GDB manual for further information. It can be
6105 enabled by configuring with:
6107 .../configure --enable-gdbmi
6109 *** Changes in GDB-4.18:
6111 * New native configurations
6113 HP-UX 10.20 hppa*-*-hpux10.20
6114 HP-UX 11.x hppa*-*-hpux11.0*
6115 M68K GNU/Linux m68*-*-linux*
6119 Fujitsu FR30 fr30-*-elf*
6120 Intel StrongARM strongarm-*-*
6121 Mitsubishi D30V d30v-*-*
6123 * OBSOLETE configurations
6125 Gould PowerNode, NP1 np1-*-*, pn-*-*
6127 Configurations that have been declared obsolete will be commented out,
6128 but the code will be left in place. If there is no activity to revive
6129 these configurations before the next release of GDB, the sources will
6130 be permanently REMOVED.
6134 As a compatibility experiment, GDB's source files buildsym.h and
6135 buildsym.c have been converted to pure standard C, no longer
6136 containing any K&R compatibility code. We believe that all systems in
6137 use today either come with a standard C compiler, or have a GCC port
6138 available. If this is not true, please report the affected
6139 configuration to bug-gdb@gnu.org immediately. See the README file for
6140 information about getting a standard C compiler if you don't have one
6145 GDB now uses readline 2.2.
6147 * set extension-language
6149 You can now control the mapping between filename extensions and source
6150 languages by using the `set extension-language' command. For instance,
6151 you can ask GDB to treat .c files as C++ by saying
6152 set extension-language .c c++
6153 The command `info extensions' lists all of the recognized extensions
6154 and their associated languages.
6156 * Setting processor type for PowerPC and RS/6000
6158 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6159 you can use the `set processor' command to specify what variant of the
6160 PowerPC family you are debugging. The command
6164 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6165 following PowerPC and RS6000 variants:
6167 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6168 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6170 403GC IBM PowerPC 403GC
6171 505 Motorola PowerPC 505
6172 860 Motorola PowerPC 860 or 850
6173 601 Motorola PowerPC 601
6174 602 Motorola PowerPC 602
6175 603 Motorola/IBM PowerPC 603 or 603e
6176 604 Motorola PowerPC 604 or 604e
6177 750 Motorola/IBM PowerPC 750 or 750
6179 At the moment, this command just tells GDB what to name the
6180 special-purpose processor registers. Since almost all the affected
6181 registers are inaccessible to user-level programs, this command is
6182 only useful for remote debugging in its present form.
6186 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6187 more extensive support for HP-UX. Added features include shared
6188 library support, kernel threads and hardware watchpoints for 11.00,
6189 support for HP's ANSI C and C++ compilers, and a compatibility mode
6190 for xdb and dbx commands.
6194 HP's donation includes the new concept of catchpoints, which is a
6195 generalization of the old catch command. On HP-UX, it is now possible
6196 to catch exec, fork, and vfork, as well as library loading.
6198 This means that the existing catch command has changed; its first
6199 argument now specifies the type of catch to be set up. See the
6200 output of "help catch" for a list of catchpoint types.
6202 * Debugging across forks
6204 On HP-UX, you can choose which process to debug when a fork() happens
6209 HP has donated a curses-based terminal user interface (TUI). To get
6210 it, build with --enable-tui. Although this can be enabled for any
6211 configuration, at present it only works for native HP debugging.
6213 * GDB remote protocol additions
6215 A new protocol packet 'X' that writes binary data is now available.
6216 Default behavior is to try 'X', then drop back to 'M' if the stub
6217 fails to respond. The settable variable `remotebinarydownload'
6218 allows explicit control over the use of 'X'.
6220 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6221 full 64-bit address. The command
6223 set remoteaddresssize 32
6225 can be used to revert to the old behaviour. For existing remote stubs
6226 the change should not be noticed, as the additional address information
6229 In order to assist in debugging stubs, you may use the maintenance
6230 command `packet' to send any text string to the stub. For instance,
6232 maint packet heythere
6234 sends the packet "$heythere#<checksum>". Note that it is very easy to
6235 disrupt a debugging session by sending the wrong packet at the wrong
6238 The compare-sections command allows you to compare section data on the
6239 target to what is in the executable file without uploading or
6240 downloading, by comparing CRC checksums.
6242 * Tracing can collect general expressions
6244 You may now collect general expressions at tracepoints. This requires
6245 further additions to the target-side stub; see tracepoint.c and
6246 doc/agentexpr.texi for further details.
6248 * mask-address variable for Mips
6250 For Mips targets, you may control the zeroing of the upper 32 bits of
6251 a 64-bit address by entering `set mask-address on'. This is mainly
6252 of interest to users of embedded R4xxx and R5xxx processors.
6254 * Higher serial baud rates
6256 GDB's serial code now allows you to specify baud rates 57600, 115200,
6257 230400, and 460800 baud. (Note that your host system may not be able
6258 to achieve all of these rates.)
6262 The i960 configuration now includes an initial implementation of a
6263 builtin simulator, contributed by Jim Wilson.
6266 *** Changes in GDB-4.17:
6268 * New native configurations
6270 Alpha GNU/Linux alpha*-*-linux*
6271 Unixware 2.x i[3456]86-unixware2*
6272 Irix 6.x mips*-sgi-irix6*
6273 PowerPC GNU/Linux powerpc-*-linux*
6274 PowerPC Solaris powerpcle-*-solaris*
6275 Sparc GNU/Linux sparc-*-linux*
6276 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6280 Argonaut Risc Chip (ARC) arc-*-*
6281 Hitachi H8/300S h8300*-*-*
6282 Matsushita MN10200 w/simulator mn10200-*-*
6283 Matsushita MN10300 w/simulator mn10300-*-*
6284 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6285 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6286 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6287 Mitsubishi D10V w/simulator d10v-*-*
6288 Mitsubishi M32R/D w/simulator m32r-*-elf*
6289 Tsqware Sparclet sparclet-*-*
6290 NEC V850 w/simulator v850-*-*
6292 * New debugging protocols
6294 ARM with RDI protocol arm*-*-*
6295 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6296 DDB and LSI variants of PMON protocol mips*-*-*
6297 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6298 PowerPC with SDS protocol powerpc{,le}-*-eabi
6299 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6303 All configurations can now understand and use the DWARF 2 debugging
6304 format. The choice is automatic, if the symbol file contains DWARF 2
6309 GDB now includes basic Java language support. This support is
6310 only useful with Java compilers that produce native machine code.
6312 * solib-absolute-prefix and solib-search-path
6314 For SunOS and SVR4 shared libraries, you may now set the prefix for
6315 loading absolute shared library symbol files, and the search path for
6316 locating non-absolute shared library symbol files.
6318 * Live range splitting
6320 GDB can now effectively debug code for which GCC has performed live
6321 range splitting as part of its optimization. See gdb/doc/LRS for
6322 more details on the expected format of the stabs information.
6326 GDB's support for the GNU Hurd, including thread debugging, has been
6327 updated to work with current versions of the Hurd.
6331 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6332 instruction set. ARM GDB automatically detects when Thumb
6333 instructions are in use, and adjusts disassembly and backtracing
6338 GDB's MIPS target configurations now handle the MIP16 16-bit
6343 GDB now includes support for overlays; if an executable has been
6344 linked such that multiple sections are based at the same address, GDB
6345 will decide which section to use for symbolic info. You can choose to
6346 control the decision manually, using overlay commands, or implement
6347 additional target-side support and use "overlay load-target" to bring
6348 in the overlay mapping. Do "help overlay" for more detail.
6352 The command "info symbol <address>" displays information about
6353 the symbol at the specified address.
6357 The standard remote protocol now includes an extension that allows
6358 asynchronous collection and display of trace data. This requires
6359 extensive support in the target-side debugging stub. Tracing mode
6360 includes a new interaction mode in GDB and new commands: see the
6361 file tracepoint.c for more details.
6365 Configurations for embedded MIPS now include a simulator contributed
6366 by Cygnus Solutions. The simulator supports the instruction sets
6367 of most MIPS variants.
6371 Sparc configurations may now include the ERC32 simulator contributed
6372 by the European Space Agency. The simulator is not built into
6373 Sparc targets by default; configure with --enable-sim to include it.
6377 For target configurations that may include multiple variants of a
6378 basic architecture (such as MIPS and SH), you may now set the
6379 architecture explicitly. "set arch" sets, "info arch" lists
6380 the possible architectures.
6382 *** Changes in GDB-4.16:
6384 * New native configurations
6386 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6387 M68K NetBSD m68k-*-netbsd*
6388 PowerPC AIX 4.x powerpc-*-aix*
6389 PowerPC MacOS powerpc-*-macos*
6390 PowerPC Windows NT powerpcle-*-cygwin32
6391 RS/6000 AIX 4.x rs6000-*-aix4*
6395 ARM with RDP protocol arm-*-*
6396 I960 with MON960 i960-*-coff
6397 MIPS VxWorks mips*-*-vxworks*
6398 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6399 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6401 Matra Sparclet sparclet-*-*
6405 The powerpc-eabi configuration now includes the PSIM simulator,
6406 contributed by Andrew Cagney, with assistance from Mike Meissner.
6407 PSIM is a very elaborate model of the PowerPC, including not only
6408 basic instruction set execution, but also details of execution unit
6409 performance and I/O hardware. See sim/ppc/README for more details.
6413 GDB now works with Solaris 2.5.
6415 * Windows 95/NT native
6417 GDB will now work as a native debugger on Windows 95 and Windows NT.
6418 To build it from source, you must use the "gnu-win32" environment,
6419 which uses a DLL to emulate enough of Unix to run the GNU tools.
6420 Further information, binaries, and sources are available at
6421 ftp.cygnus.com, under pub/gnu-win32.
6423 * dont-repeat command
6425 If a user-defined command includes the command `dont-repeat', then the
6426 command will not be repeated if the user just types return. This is
6427 useful if the command is time-consuming to run, so that accidental
6428 extra keystrokes don't run the same command many times.
6430 * Send break instead of ^C
6432 The standard remote protocol now includes an option to send a break
6433 rather than a ^C to the target in order to interrupt it. By default,
6434 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6436 * Remote protocol timeout
6438 The standard remote protocol includes a new variable `remotetimeout'
6439 that allows you to set the number of seconds before GDB gives up trying
6440 to read from the target. The default value is 2.
6442 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6444 By default GDB will automatically keep track of objects as they are
6445 loaded and unloaded by the dynamic linker. By using the command `set
6446 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6447 when shared library events occur, thus allowing you to set breakpoints
6448 in shared libraries which are explicitly loaded by the inferior.
6450 Note this feature does not work on hpux8. On hpux9 you must link
6451 /usr/lib/end.o into your program. This feature should work
6452 automatically on hpux10.
6454 * Irix 5.x hardware watchpoint support
6456 Irix 5 configurations now support the use of hardware watchpoints.
6458 * Mips protocol "SYN garbage limit"
6460 When debugging a Mips target using the `target mips' protocol, you
6461 may set the number of characters that GDB will ignore by setting
6462 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6463 every character. The default value is 1050.
6465 * Recording and replaying remote debug sessions
6467 If you set `remotelogfile' to the name of a file, gdb will write to it
6468 a recording of a remote debug session. This recording may then be
6469 replayed back to gdb using "gdbreplay". See gdbserver/README for
6470 details. This is useful when you have a problem with GDB while doing
6471 remote debugging; you can make a recording of the session and send it
6472 to someone else, who can then recreate the problem.
6474 * Speedups for remote debugging
6476 GDB includes speedups for downloading and stepping MIPS systems using
6477 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6478 and more efficient S-record downloading.
6480 * Memory use reductions and statistics collection
6482 GDB now uses less memory and reports statistics about memory usage.
6483 Try the `maint print statistics' command, for example.
6485 *** Changes in GDB-4.15:
6487 * Psymtabs for XCOFF
6489 The symbol reader for AIX GDB now uses partial symbol tables. This
6490 can greatly improve startup time, especially for large executables.
6492 * Remote targets use caching
6494 Remote targets now use a data cache to speed up communication with the
6495 remote side. The data cache could lead to incorrect results because
6496 it doesn't know about volatile variables, thus making it impossible to
6497 debug targets which use memory mapped I/O devices. `set remotecache
6498 off' turns the the data cache off.
6500 * Remote targets may have threads
6502 The standard remote protocol now includes support for multiple threads
6503 in the target system, using new protocol commands 'H' and 'T'. See
6504 gdb/remote.c for details.
6508 If GDB is configured with `--enable-netrom', then it will include
6509 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6510 acts as though it is a bank of ROM on the target board, but you can
6511 write into it over the network. GDB's support consists only of
6512 support for fast loading into the emulated ROM; to debug, you must use
6513 another protocol, such as standard remote protocol. The usual
6514 sequence is something like
6516 target nrom <netrom-hostname>
6518 target remote <netrom-hostname>:1235
6522 GDB now includes support for the Apple Macintosh, as a host only. It
6523 may be run as either an MPW tool or as a standalone application, and
6524 it can debug through the serial port. All the usual GDB commands are
6525 available, but to the target command, you must supply "serial" as the
6526 device type instead of "/dev/ttyXX". See mpw-README in the main
6527 directory for more information on how to build. The MPW configuration
6528 scripts */mpw-config.in support only a few targets, and only the
6529 mips-idt-ecoff target has been tested.
6533 GDB configuration now uses autoconf. This is not user-visible,
6534 but does simplify configuration and building.
6538 GDB now supports hpux10.
6540 *** Changes in GDB-4.14:
6542 * New native configurations
6544 x86 FreeBSD i[345]86-*-freebsd
6545 x86 NetBSD i[345]86-*-netbsd
6546 NS32k NetBSD ns32k-*-netbsd
6547 Sparc NetBSD sparc-*-netbsd
6551 A29K VxWorks a29k-*-vxworks
6552 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6553 CPU32 EST-300 emulator m68*-*-est*
6554 PowerPC ELF powerpc-*-elf
6557 * Alpha OSF/1 support for procfs
6559 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6560 possible to attach to running processes. As the mounting of the /proc
6561 filesystem is optional on the Alpha, GDB automatically determines
6562 the availability of /proc during startup. This can lead to problems
6563 if /proc is unmounted after GDB has been started.
6565 * Arguments to user-defined commands
6567 User commands may accept up to 10 arguments separated by whitespace.
6568 Arguments are accessed within the user command via $arg0..$arg9. A
6571 print $arg0 + $arg1 + $arg2
6573 To execute the command use:
6576 Defines the command "adder" which prints the sum of its three arguments.
6577 Note the arguments are text substitutions, so they may reference variables,
6578 use complex expressions, or even perform inferior function calls.
6580 * New `if' and `while' commands
6582 This makes it possible to write more sophisticated user-defined
6583 commands. Both commands take a single argument, which is the
6584 expression to evaluate, and must be followed by the commands to
6585 execute, one per line, if the expression is nonzero, the list being
6586 terminated by the word `end'. The `if' command list may include an
6587 `else' word, which causes the following commands to be executed only
6588 if the expression is zero.
6590 * Fortran source language mode
6592 GDB now includes partial support for Fortran 77. It will recognize
6593 Fortran programs and can evaluate a subset of Fortran expressions, but
6594 variables and functions may not be handled correctly. GDB will work
6595 with G77, but does not yet know much about symbols emitted by other
6598 * Better HPUX support
6600 Most debugging facilities now work on dynamic executables for HPPAs
6601 running hpux9 or later. You can attach to running dynamically linked
6602 processes, but by default the dynamic libraries will be read-only, so
6603 for instance you won't be able to put breakpoints in them. To change
6604 that behavior do the following before running the program:
6610 This will cause the libraries to be mapped private and read-write.
6611 To revert to the normal behavior, do this:
6617 You cannot set breakpoints or examine data in the library until after
6618 the library is loaded if the function/data symbols do not have
6621 GDB can now also read debug symbols produced by the HP C compiler on
6622 HPPAs (sorry, no C++, Fortran or 68k support).
6624 * Target byte order now dynamically selectable
6626 You can choose which byte order to use with a target system, via the
6627 commands "set endian big" and "set endian little", and you can see the
6628 current setting by using "show endian". You can also give the command
6629 "set endian auto", in which case GDB will use the byte order
6630 associated with the executable. Currently, only embedded MIPS
6631 configurations support dynamic selection of target byte order.
6633 * New DOS host serial code
6635 This version uses DPMI interrupts to handle buffered I/O, so you
6636 no longer need to run asynctsr when debugging boards connected to
6639 *** Changes in GDB-4.13:
6641 * New "complete" command
6643 This lists all the possible completions for the rest of the line, if it
6644 were to be given as a command itself. This is intended for use by emacs.
6646 * Trailing space optional in prompt
6648 "set prompt" no longer adds a space for you after the prompt you set. This
6649 allows you to set a prompt which ends in a space or one that does not.
6651 * Breakpoint hit counts
6653 "info break" now displays a count of the number of times the breakpoint
6654 has been hit. This is especially useful in conjunction with "ignore"; you
6655 can ignore a large number of breakpoint hits, look at the breakpoint info
6656 to see how many times the breakpoint was hit, then run again, ignoring one
6657 less than that number, and this will get you quickly to the last hit of
6660 * Ability to stop printing at NULL character
6662 "set print null-stop" will cause GDB to stop printing the characters of
6663 an array when the first NULL is encountered. This is useful when large
6664 arrays actually contain only short strings.
6666 * Shared library breakpoints
6668 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6669 breakpoints in shared libraries before the executable is run.
6671 * Hardware watchpoints
6673 There is a new hardware breakpoint for the watch command for sparclite
6674 targets. See gdb/sparclite/hw_breakpoint.note.
6676 Hardware watchpoints are also now supported under GNU/Linux.
6680 Annotations have been added. These are for use with graphical interfaces,
6681 and are still experimental. Currently only gdba.el uses these.
6683 * Improved Irix 5 support
6685 GDB now works properly with Irix 5.2.
6687 * Improved HPPA support
6689 GDB now works properly with the latest GCC and GAS.
6691 * New native configurations
6693 Sequent PTX4 i[34]86-sequent-ptx4
6694 HPPA running OSF/1 hppa*-*-osf*
6695 Atari TT running SVR4 m68*-*-sysv4*
6696 RS/6000 LynxOS rs6000-*-lynxos*
6700 OS/9000 i[34]86-*-os9k
6701 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6704 * Hitachi SH7000 and E7000-PC ICE support
6706 There is now support for communicating with the Hitachi E7000-PC ICE.
6707 This is available automatically when GDB is configured for the SH.
6711 As usual, a variety of small fixes and improvements, both generic
6712 and configuration-specific. See the ChangeLog for more detail.
6714 *** Changes in GDB-4.12:
6716 * Irix 5 is now supported
6720 GDB-4.12 on the HPPA has a number of changes which make it unable
6721 to debug the output from the currently released versions of GCC and
6722 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6723 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6724 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6727 *** Changes in GDB-4.11:
6729 * User visible changes:
6733 The "set remotedebug" option is now consistent between the mips remote
6734 target, remote targets using the gdb-specific protocol, UDI (AMD's
6735 debug protocol for the 29k) and the 88k bug monitor. It is now an
6736 integer specifying a debug level (normally 0 or 1, but 2 means more
6737 debugging info for the mips target).
6739 * DEC Alpha native support
6741 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6742 debug info, but GDB works fairly well with the DEC compiler and should
6743 work with a future GCC release. See the README file for a few
6744 Alpha-specific notes.
6746 * Preliminary thread implementation
6748 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6750 * LynxOS native and target support for 386
6752 This release has been hosted on LynxOS 2.2, and also can be configured
6753 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6756 * Improvements in C++ mangling/demangling.
6758 This release has much better g++ debugging, specifically in name
6759 mangling/demangling, virtual function calls, print virtual table,
6760 call methods, ...etc.
6762 *** Changes in GDB-4.10:
6764 * User visible changes:
6766 Remote debugging using the GDB-specific (`target remote') protocol now
6767 supports the `load' command. This is only useful if you have some
6768 other way of getting the stub to the target system, and you can put it
6769 somewhere in memory where it won't get clobbered by the download.
6771 Filename completion now works.
6773 When run under emacs mode, the "info line" command now causes the
6774 arrow to point to the line specified. Also, "info line" prints
6775 addresses in symbolic form (as well as hex).
6777 All vxworks based targets now support a user settable option, called
6778 vxworks-timeout. This option represents the number of seconds gdb
6779 should wait for responses to rpc's. You might want to use this if
6780 your vxworks target is, perhaps, a slow software simulator or happens
6781 to be on the far side of a thin network line.
6785 This release contains support for using a DEC alpha as a GDB host for
6786 cross debugging. Native alpha debugging is not supported yet.
6789 *** Changes in GDB-4.9:
6793 This is the first GDB release which is accompanied by a matching testsuite.
6794 The testsuite requires installation of dejagnu, which should be available
6795 via ftp from most sites that carry GNU software.
6799 'Cfront' style demangling has had its name changed to 'ARM' style, to
6800 emphasize that it was written from the specifications in the C++ Annotated
6801 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6802 disclaimers, it still generated too much confusion with users attempting to
6803 use gdb with AT&T cfront.
6807 GDB now uses a standard remote interface to a simulator library.
6808 So far, the library contains simulators for the Zilog Z8001/2, the
6809 Hitachi H8/300, H8/500 and Super-H.
6811 * New targets supported
6813 H8/300 simulator h8300-hitachi-hms or h8300hms
6814 H8/500 simulator h8500-hitachi-hms or h8500hms
6815 SH simulator sh-hitachi-hms or sh
6816 Z8000 simulator z8k-zilog-none or z8ksim
6817 IDT MIPS board over serial line mips-idt-ecoff
6819 Cross-debugging to GO32 targets is supported. It requires a custom
6820 version of the i386-stub.c module which is integrated with the
6821 GO32 memory extender.
6823 * New remote protocols
6825 MIPS remote debugging protocol.
6827 * New source languages supported
6829 This version includes preliminary support for Chill, a Pascal like language
6830 used by telecommunications companies. Chill support is also being integrated
6831 into the GNU compiler, but we don't know when it will be publically available.
6834 *** Changes in GDB-4.8:
6836 * HP Precision Architecture supported
6838 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6839 version of this support was available as a set of patches from the
6840 University of Utah. GDB does not support debugging of programs
6841 compiled with the HP compiler, because HP will not document their file
6842 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6843 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6845 Many problems in the preliminary version have been fixed.
6847 * Faster and better demangling
6849 We have improved template demangling and fixed numerous bugs in the GNU style
6850 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6851 character types (wchar_t) are now supported. Demangling of each symbol is now
6852 only done once, and is cached when the symbol table for a file is read in.
6853 This results in a small increase in memory usage for C programs, a moderate
6854 increase in memory usage for C++ programs, and a fantastic speedup in
6857 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6858 from the specifications in the Annotated Reference Manual, which AT&T's
6859 compiler does not actually implement.
6861 * G++ multiple inheritance compiler problem
6863 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6864 inheritance lattices was reworked to properly discover ambiguities. We
6865 recently found an example which causes this new algorithm to fail in a
6866 very subtle way, producing bad debug information for those classes.
6867 The file 'gcc.patch' (in this directory) can be applied to gcc to
6868 circumvent the problem. A future GCC release will contain a complete
6871 The previous G++ debug info problem (mentioned below for the gdb-4.7
6872 release) is fixed in gcc version 2.3.2.
6874 * Improved configure script
6876 The `configure' script will now attempt to guess your system type if
6877 you don't supply a host system type. The old scheme of supplying a
6878 host system triplet is preferable over using this. All the magic is
6879 done in the new `config.guess' script. Examine it for details.
6881 We have also brought our configure script much more in line with the FSF's
6882 version. It now supports the --with-xxx options. In particular,
6883 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6884 The resulting GDB will not be able to read arbitrary object file formats --
6885 only the format ``expected'' to be used on the configured target system.
6886 We hope to make this the default in a future release.
6888 * Documentation improvements
6890 There's new internal documentation on how to modify GDB, and how to
6891 produce clean changes to the code. We implore people to read it
6892 before submitting changes.
6894 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6895 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6896 `info' files are also provided. To build `info' files from scratch,
6897 you will need the latest `makeinfo' release, which will be available in
6898 a future texinfo-X.Y release.
6900 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6901 We're not sure exactly which versions have this problem, but it has
6902 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6903 or better. If that isn't possible, there is a patch in
6904 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6905 around this problem.
6909 GDB now supports array constants that can be used in expressions typed in by
6910 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6911 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6914 The new directory `gdb/sparclite' contains a program that demonstrates
6915 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6917 * New native hosts supported
6919 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6920 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6922 * New targets supported
6924 AMD 29k family via UDI a29k-amd-udi or udi29k
6926 * New file formats supported
6928 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6929 HPUX core files, and SCO 3.2v2 core files.
6933 Attaching to processes now works again; thanks for the many bug reports.
6935 We have also stomped on a bunch of core dumps caused by
6936 printf_filtered("%s") problems.
6938 We eliminated a copyright problem on the rpc and ptrace header files
6939 for VxWorks, which was discovered at the last minute during the 4.7
6940 release. You should now be able to build a VxWorks GDB.
6942 You can now interrupt gdb while an attached process is running. This
6943 will cause the attached process to stop, and give control back to GDB.
6945 We fixed problems caused by using too many file descriptors
6946 for reading symbols from object files and libraries. This was
6947 especially a problem for programs that used many (~100) shared
6950 The `step' command now only enters a subroutine if there is line number
6951 information for the subroutine. Otherwise it acts like the `next'
6952 command. Previously, `step' would enter subroutines if there was
6953 any debugging information about the routine. This avoids problems
6954 when using `cc -g1' on MIPS machines.
6956 * Internal improvements
6958 GDB's internal interfaces have been improved to make it easier to support
6959 debugging of multiple languages in the future.
6961 GDB now uses a common structure for symbol information internally.
6962 Minimal symbols (derived from linkage symbols in object files), partial
6963 symbols (from a quick scan of debug information), and full symbols
6964 contain a common subset of information, making it easier to write
6965 shared code that handles any of them.
6967 * New command line options
6969 We now accept --silent as an alias for --quiet.
6973 The memory-mapped-malloc library is now licensed under the GNU Library
6974 General Public License.
6976 *** Changes in GDB-4.7:
6978 * Host/native/target split
6980 GDB has had some major internal surgery to untangle the support for
6981 hosts and remote targets. Now, when you configure GDB for a remote
6982 target, it will no longer load in all of the support for debugging
6983 local programs on the host. When fully completed and tested, this will
6984 ensure that arbitrary host/target combinations are possible.
6986 The primary conceptual shift is to separate the non-portable code in
6987 GDB into three categories. Host specific code is required any time GDB
6988 is compiled on that host, regardless of the target. Target specific
6989 code relates to the peculiarities of the target, but can be compiled on
6990 any host. Native specific code is everything else: it can only be
6991 built when the host and target are the same system. Child process
6992 handling and core file support are two common `native' examples.
6994 GDB's use of /proc for controlling Unix child processes is now cleaner.
6995 It has been split out into a single module under the `target_ops' vector,
6996 plus two native-dependent functions for each system that uses /proc.
6998 * New hosts supported
7000 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7001 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7002 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7004 * New targets supported
7006 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7007 68030 and CPU32 m68030-*-*, m68332-*-*
7009 * New native hosts supported
7011 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7012 (386bsd is not well tested yet)
7013 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7015 * New file formats supported
7017 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7018 supports reading of `a.out.adobe' object files, which are an a.out
7019 format extended with minimal information about multiple sections.
7023 `show copying' is the same as the old `info copying'.
7024 `show warranty' is the same as `info warrantee'.
7025 These were renamed for consistency. The old commands continue to work.
7027 `info handle' is a new alias for `info signals'.
7029 You can now define pre-command hooks, which attach arbitrary command
7030 scripts to any command. The commands in the hook will be executed
7031 prior to the user's command. You can also create a hook which will be
7032 executed whenever the program stops. See gdb.texinfo.
7036 We now deal with Cfront style name mangling, and can even extract type
7037 info from mangled symbols. GDB can automatically figure out which
7038 symbol mangling style your C++ compiler uses.
7040 Calling of methods and virtual functions has been improved as well.
7044 The crash that occured when debugging Sun Ansi-C compiled binaries is
7045 fixed. This was due to mishandling of the extra N_SO stabs output
7048 We also finally got Ultrix 4.2 running in house, and fixed core file
7049 support, with help from a dozen people on the net.
7051 John M. Farrell discovered that the reason that single-stepping was so
7052 slow on all of the Mips based platforms (primarily SGI and DEC) was
7053 that we were trying to demangle and lookup a symbol used for internal
7054 purposes on every instruction that was being stepped through. Changing
7055 the name of that symbol so that it couldn't be mistaken for a C++
7056 mangled symbol sped things up a great deal.
7058 Rich Pixley sped up symbol lookups in general by getting much smarter
7059 about when C++ symbol mangling is necessary. This should make symbol
7060 completion (TAB on the command line) much faster. It's not as fast as
7061 we'd like, but it's significantly faster than gdb-4.6.
7065 A new user controllable variable 'call_scratch_address' can
7066 specify the location of a scratch area to be used when GDB
7067 calls a function in the target. This is necessary because the
7068 usual method of putting the scratch area on the stack does not work
7069 in systems that have separate instruction and data spaces.
7071 We integrated changes to support the 29k UDI (Universal Debugger
7072 Interface), but discovered at the last minute that we didn't have all
7073 of the appropriate copyright paperwork. We are working with AMD to
7074 resolve this, and hope to have it available soon.
7078 We have sped up the remote serial line protocol, especially for targets
7079 with lots of registers. It now supports a new `expedited status' ('T')
7080 message which can be used in place of the existing 'S' status message.
7081 This allows the remote stub to send only the registers that GDB
7082 needs to make a quick decision about single-stepping or conditional
7083 breakpoints, eliminating the need to fetch the entire register set for
7084 each instruction being stepped through.
7086 The GDB remote serial protocol now implements a write-through cache for
7087 registers, only re-reading the registers if the target has run.
7089 There is also a new remote serial stub for SPARC processors. You can
7090 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7091 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7092 processor with a serial port.
7096 Configure.in files have become much easier to read and modify. A new
7097 `table driven' format makes it more obvious what configurations are
7098 supported, and what files each one uses.
7102 There is a new opcodes library which will eventually contain all of the
7103 disassembly routines and opcode tables. At present, it only contains
7104 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7105 disassembler (binutils/objdump) to share these routines.
7107 The libiberty library is now copylefted under the GNU Library General
7108 Public License. This allows more liberal use, and was done so libg++
7109 can use it. This makes no difference to GDB, since the Library License
7110 grants all the rights from the General Public License.
7114 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7115 reference to the stabs symbol info used by the debugger. It is (as far
7116 as we know) the only published document on this fascinating topic. We
7117 encourage you to read it, compare it to the stabs information on your
7118 system, and send improvements on the document in general (to
7119 bug-gdb@prep.ai.mit.edu).
7121 And, of course, many bugs have been fixed.
7124 *** Changes in GDB-4.6:
7126 * Better support for C++ function names
7128 GDB now accepts as input the "demangled form" of C++ overloaded function
7129 names and member function names, and can do command completion on such names
7130 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7131 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7132 Make use of command completion, it is your friend.
7134 GDB also now accepts a variety of C++ mangled symbol formats. They are
7135 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7136 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7137 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7138 for the list of formats.
7140 * G++ symbol mangling problem
7142 Recent versions of gcc have a bug in how they emit debugging information for
7143 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7144 directory) can be applied to gcc to fix the problem. Alternatively, if you
7145 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7146 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7147 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7150 * New 'maintenance' command
7152 All of the commands related to hacking GDB internals have been moved out of
7153 the main command set, and now live behind the 'maintenance' command. This
7154 can also be abbreviated as 'mt'. The following changes were made:
7156 dump-me -> maintenance dump-me
7157 info all-breakpoints -> maintenance info breakpoints
7158 printmsyms -> maintenance print msyms
7159 printobjfiles -> maintenance print objfiles
7160 printpsyms -> maintenance print psymbols
7161 printsyms -> maintenance print symbols
7163 The following commands are new:
7165 maintenance demangle Call internal GDB demangler routine to
7166 demangle a C++ link name and prints the result.
7167 maintenance print type Print a type chain for a given symbol
7169 * Change to .gdbinit file processing
7171 We now read the $HOME/.gdbinit file before processing the argv arguments
7172 (e.g. reading symbol files or core files). This allows global parameters to
7173 be set, which will apply during the symbol reading. The ./.gdbinit is still
7174 read after argv processing.
7176 * New hosts supported
7178 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7180 GNU/Linux support i386-unknown-linux or linux
7182 We are also including code to support the HP/PA running BSD and HPUX. This
7183 is almost guaranteed not to work, as we didn't have time to test or build it
7184 for this release. We are including it so that the more adventurous (or
7185 masochistic) of you can play with it. We also had major problems with the
7186 fact that the compiler that we got from HP doesn't support the -g option.
7189 * New targets supported
7191 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7193 * More smarts about finding #include files
7195 GDB now remembers the compilation directory for all include files, and for
7196 all files from which C is generated (like yacc and lex sources). This
7197 greatly improves GDB's ability to find yacc/lex sources, and include files,
7198 especially if you are debugging your program from a directory different from
7199 the one that contains your sources.
7201 We also fixed a bug which caused difficulty with listing and setting
7202 breakpoints in include files which contain C code. (In the past, you had to
7203 try twice in order to list an include file that you hadn't looked at before.)
7205 * Interesting infernals change
7207 GDB now deals with arbitrary numbers of sections, where the symbols for each
7208 section must be relocated relative to that section's landing place in the
7209 target's address space. This work was needed to support ELF with embedded
7210 stabs used by Solaris-2.0.
7212 * Bug fixes (of course!)
7214 There have been loads of fixes for the following things:
7215 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7216 i960, stabs, DOS(GO32), procfs, etc...
7218 See the ChangeLog for details.
7220 *** Changes in GDB-4.5:
7222 * New machines supported (host and target)
7224 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7226 SGI Irix-4.x mips-sgi-irix4 or iris4
7228 * New malloc package
7230 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7231 Mmalloc is capable of handling mutiple heaps of memory. It is also
7232 capable of saving a heap to a file, and then mapping it back in later.
7233 This can be used to greatly speedup the startup of GDB by using a
7234 pre-parsed symbol table which lives in a mmalloc managed heap. For
7235 more details, please read mmalloc/mmalloc.texi.
7239 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7240 'help info proc' for details.
7242 * MIPS ecoff symbol table format
7244 The code that reads MIPS symbol table format is now supported on all hosts.
7245 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7248 * File name changes for MS-DOS
7250 Many files in the config directories have been renamed to make it easier to
7251 support GDB on MS-DOSe systems (which have very restrictive file name
7252 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7253 environment) is close to working but has some remaining problems. Note
7254 that debugging of DOS programs is not supported, due to limitations
7255 in the ``operating system'', but it can be used to host cross-debugging.
7257 * Cross byte order fixes
7259 Many fixes have been made to support cross debugging of Sparc and MIPS
7260 targets from hosts whose byte order differs.
7262 * New -mapped and -readnow options
7264 If memory-mapped files are available on your system through the 'mmap'
7265 system call, you can use the -mapped option on the `file' or
7266 `symbol-file' commands to cause GDB to write the symbols from your
7267 program into a reusable file. If the program you are debugging is
7268 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7269 Future GDB debugging sessions will notice the presence of this file,
7270 and will quickly map in symbol information from it, rather than reading
7271 the symbol table from the executable program. Using the '-mapped'
7272 option in a GDB `file' or `symbol-file' command has the same effect as
7273 starting GDB with the '-mapped' command-line option.
7275 You can cause GDB to read the entire symbol table immediately by using
7276 the '-readnow' option with any of the commands that load symbol table
7277 information (or on the GDB command line). This makes the command
7278 slower, but makes future operations faster.
7280 The -mapped and -readnow options are typically combined in order to
7281 build a `fred.syms' file that contains complete symbol information.
7282 A simple GDB invocation to do nothing but build a `.syms' file for future
7285 gdb -batch -nx -mapped -readnow programname
7287 The `.syms' file is specific to the host machine on which GDB is run.
7288 It holds an exact image of GDB's internal symbol table. It cannot be
7289 shared across multiple host platforms.
7291 * longjmp() handling
7293 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7294 siglongjmp() without losing control. This feature has not yet been ported to
7295 all systems. It currently works on many 386 platforms, all MIPS-based
7296 platforms (SGI, DECstation, etc), and Sun3/4.
7300 Preliminary work has been put in to support the new Solaris OS from Sun. At
7301 this time, it can control and debug processes, but it is not capable of
7306 As always, many many bug fixes. The major areas were with g++, and mipsread.
7307 People using the MIPS-based platforms should experience fewer mysterious
7308 crashes and trashed symbol tables.
7310 *** Changes in GDB-4.4:
7312 * New machines supported (host and target)
7314 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7316 BSD Reno on Vax vax-dec-bsd
7317 Ultrix on Vax vax-dec-ultrix
7319 * New machines supported (target)
7321 AMD 29000 embedded, using EBMON a29k-none-none
7325 GDB continues to improve its handling of C++. `References' work better.
7326 The demangler has also been improved, and now deals with symbols mangled as
7327 per the Annotated C++ Reference Guide.
7329 GDB also now handles `stabs' symbol information embedded in MIPS
7330 `ecoff' symbol tables. Since the ecoff format was not easily
7331 extensible to handle new languages such as C++, this appeared to be a
7332 good way to put C++ debugging info into MIPS binaries. This option
7333 will be supported in the GNU C compiler, version 2, when it is
7336 * New features for SVR4
7338 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7339 shared libraries. Debugging dynamically linked programs should present
7340 only minor differences from debugging statically linked programs.
7342 The `info proc' command will print out information about any process
7343 on an SVR4 system (including the one you are debugging). At the moment,
7344 it prints the address mappings of the process.
7346 If you bring up GDB on another SVR4 system, please send mail to
7347 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7349 * Better dynamic linking support in SunOS
7351 Reading symbols from shared libraries which contain debugging symbols
7352 now works properly. However, there remain issues such as automatic
7353 skipping of `transfer vector' code during function calls, which
7354 make it harder to debug code in a shared library, than to debug the
7355 same code linked statically.
7359 GDB is now using the latest `getopt' routines from the FSF. This
7360 version accepts the -- prefix for options with long names. GDB will
7361 continue to accept the old forms (-option and +option) as well.
7362 Various single letter abbreviations for options have been explicity
7363 added to the option table so that they won't get overshadowed in the
7364 future by other options that begin with the same letter.
7368 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7369 Many assorted bugs have been handled. Many more remain to be handled.
7370 See the various ChangeLog files (primarily in gdb and bfd) for details.
7373 *** Changes in GDB-4.3:
7375 * New machines supported (host and target)
7377 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7378 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7379 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7381 * Almost SCO Unix support
7383 We had hoped to support:
7384 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7385 (except for core file support), but we discovered very late in the release
7386 that it has problems with process groups that render gdb unusable. Sorry
7387 about that. I encourage people to fix it and post the fixes.
7389 * Preliminary ELF and DWARF support
7391 GDB can read ELF object files on System V Release 4, and can handle
7392 debugging records for C, in DWARF format, in ELF files. This support
7393 is preliminary. If you bring up GDB on another SVR4 system, please
7394 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7399 GDB now uses the latest `readline' library. One user-visible change
7400 is that two tabs will list possible command completions, which previously
7401 required typing M-? (meta-question mark, or ESC ?).
7405 The `stepi' bug that many of you noticed has been squashed.
7406 Many bugs in C++ have been handled. Many more remain to be handled.
7407 See the various ChangeLog files (primarily in gdb and bfd) for details.
7409 * State of the MIPS world (in case you wondered):
7411 GDB can understand the symbol tables emitted by the compilers
7412 supplied by most vendors of MIPS-based machines, including DEC. These
7413 symbol tables are in a format that essentially nobody else uses.
7415 Some versions of gcc come with an assembler post-processor called
7416 mips-tfile. This program is required if you want to do source-level
7417 debugging of gcc-compiled programs. I believe FSF does not ship
7418 mips-tfile with gcc version 1, but it will eventually come with gcc
7421 Debugging of g++ output remains a problem. g++ version 1.xx does not
7422 really support it at all. (If you're lucky, you should be able to get
7423 line numbers and stack traces to work, but no parameters or local
7424 variables.) With some work it should be possible to improve the
7427 When gcc version 2 is released, you will have somewhat better luck.
7428 However, even then you will get confusing results for inheritance and
7431 We will eventually provide full debugging of g++ output on
7432 DECstations. This will probably involve some kind of stabs-in-ecoff
7433 encapulation, but the details have not been worked out yet.
7436 *** Changes in GDB-4.2:
7438 * Improved configuration
7440 Only one copy of `configure' exists now, and it is not self-modifying.
7441 Porting BFD is simpler.
7445 The `step' and `next' commands now only stop at the first instruction
7446 of a source line. This prevents the multiple stops that used to occur
7447 in switch statements, for-loops, etc. `Step' continues to stop if a
7448 function that has debugging information is called within the line.
7452 Lots of small bugs fixed. More remain.
7454 * New host supported (not target)
7456 Intel 386 PC clone running Mach i386-none-mach
7459 *** Changes in GDB-4.1:
7461 * Multiple source language support
7463 GDB now has internal scaffolding to handle several source languages.
7464 It determines the type of each source file from its filename extension,
7465 and will switch expression parsing and number formatting to match the
7466 language of the function in the currently selected stack frame.
7467 You can also specifically set the language to be used, with
7468 `set language c' or `set language modula-2'.
7472 GDB now has preliminary support for the GNU Modula-2 compiler,
7473 currently under development at the State University of New York at
7474 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7475 continue through the fall of 1991 and into 1992.
7477 Other Modula-2 compilers are currently not supported, and attempting to
7478 debug programs compiled with them will likely result in an error as the
7479 symbol table is read. Feel free to work on it, though!
7481 There are hooks in GDB for strict type checking and range checking,
7482 in the `Modula-2 philosophy', but they do not currently work.
7486 GDB can now write to executable and core files (e.g. patch
7487 a variable's value). You must turn this switch on, specify
7488 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7489 by assigning a new value to a variable. Modifications take
7492 * Automatic SunOS shared library reading
7494 When you run your program, GDB automatically determines where its
7495 shared libraries (if any) have been loaded, and reads their symbols.
7496 The `share' command is no longer needed. This also works when
7497 examining core files.
7501 You can specify the number of lines that the `list' command shows.
7504 * New machines supported (host and target)
7506 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7507 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7508 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7510 * New hosts supported (not targets)
7512 IBM RT/PC: romp-ibm-aix or rtpc
7514 * New targets supported (not hosts)
7516 AMD 29000 embedded with COFF a29k-none-coff
7517 AMD 29000 embedded with a.out a29k-none-aout
7518 Ultracomputer remote kernel debug a29k-nyu-kern
7520 * New remote interfaces
7526 *** Changes in GDB-4.0:
7530 Wide output is wrapped at good places to make the output more readable.
7532 Gdb now supports cross-debugging from a host machine of one type to a
7533 target machine of another type. Communication with the target system
7534 is over serial lines. The ``target'' command handles connecting to the
7535 remote system; the ``load'' command will download a program into the
7536 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7537 also supports debugging of realtime processes running under VxWorks,
7538 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7539 stub on the target system.
7541 New CPUs supported include the AMD 29000 and Intel 960.
7543 GDB now reads object files and symbol tables via a ``binary file''
7544 library, which allows a single copy of GDB to debug programs of multiple
7545 object file types such as a.out and coff.
7547 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7548 refcard.dvi and refcard.ps are available to format it).
7551 * Control-Variable user interface simplified
7553 All variables that control the operation of the debugger can be set
7554 by the ``set'' command, and displayed by the ``show'' command.
7556 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7557 ``Show prompt'' produces the response:
7558 Gdb's prompt is new-gdb=>.
7560 What follows are the NEW set commands. The command ``help set'' will
7561 print a complete list of old and new set commands. ``help set FOO''
7562 will give a longer description of the variable FOO. ``show'' will show
7563 all of the variable descriptions and their current settings.
7565 confirm on/off: Enables warning questions for operations that are
7566 hard to recover from, e.g. rerunning the program while
7567 it is already running. Default is ON.
7569 editing on/off: Enables EMACS style command line editing
7570 of input. Previous lines can be recalled with
7571 control-P, the current line can be edited with control-B,
7572 you can search for commands with control-R, etc.
7575 history filename NAME: NAME is where the gdb command history
7576 will be stored. The default is .gdb_history,
7577 or the value of the environment variable
7580 history size N: The size, in commands, of the command history. The
7581 default is 256, or the value of the environment variable
7584 history save on/off: If this value is set to ON, the history file will
7585 be saved after exiting gdb. If set to OFF, the
7586 file will not be saved. The default is OFF.
7588 history expansion on/off: If this value is set to ON, then csh-like
7589 history expansion will be performed on
7590 command line input. The default is OFF.
7592 radix N: Sets the default radix for input and output. It can be set
7593 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7594 in the current radix, so "set radix 10" is always a no-op.
7596 height N: This integer value is the number of lines on a page. Default
7597 is 24, the current `stty rows'' setting, or the ``li#''
7598 setting from the termcap entry matching the environment
7601 width N: This integer value is the number of characters on a line.
7602 Default is 80, the current `stty cols'' setting, or the ``co#''
7603 setting from the termcap entry matching the environment
7606 Note: ``set screensize'' is obsolete. Use ``set height'' and
7607 ``set width'' instead.
7609 print address on/off: Print memory addresses in various command displays,
7610 such as stack traces and structure values. Gdb looks
7611 more ``symbolic'' if you turn this off; it looks more
7612 ``machine level'' with it on. Default is ON.
7614 print array on/off: Prettyprint arrays. New convenient format! Default
7617 print demangle on/off: Print C++ symbols in "source" form if on,
7620 print asm-demangle on/off: Same, for assembler level printouts
7623 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7626 * Support for Epoch Environment.
7628 The epoch environment is a version of Emacs v18 with windowing. One
7629 new command, ``inspect'', is identical to ``print'', except that if you
7630 are running in the epoch environment, the value is printed in its own
7634 * Support for Shared Libraries
7636 GDB can now debug programs and core files that use SunOS shared libraries.
7637 Symbols from a shared library cannot be referenced
7638 before the shared library has been linked with the program (this
7639 happens after you type ``run'' and before the function main() is entered).
7640 At any time after this linking (including when examining core files
7641 from dynamically linked programs), gdb reads the symbols from each
7642 shared library when you type the ``sharedlibrary'' command.
7643 It can be abbreviated ``share''.
7645 sharedlibrary REGEXP: Load shared object library symbols for files
7646 matching a unix regular expression. No argument
7647 indicates to load symbols for all shared libraries.
7649 info sharedlibrary: Status of loaded shared libraries.
7654 A watchpoint stops execution of a program whenever the value of an
7655 expression changes. Checking for this slows down execution
7656 tremendously whenever you are in the scope of the expression, but is
7657 quite useful for catching tough ``bit-spreader'' or pointer misuse
7658 problems. Some machines such as the 386 have hardware for doing this
7659 more quickly, and future versions of gdb will use this hardware.
7661 watch EXP: Set a watchpoint (breakpoint) for an expression.
7663 info watchpoints: Information about your watchpoints.
7665 delete N: Deletes watchpoint number N (same as breakpoints).
7666 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7667 enable N: Re-enables watchpoint number N (same as breakpoints).
7670 * C++ multiple inheritance
7672 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7675 * C++ exception handling
7677 Gdb now supports limited C++ exception handling. Besides the existing
7678 ability to breakpoint on an exception handler, gdb can breakpoint on
7679 the raising of an exception (before the stack is peeled back to the
7682 catch FOO: If there is a FOO exception handler in the dynamic scope,
7683 set a breakpoint to catch exceptions which may be raised there.
7684 Multiple exceptions (``catch foo bar baz'') may be caught.
7686 info catch: Lists all exceptions which may be caught in the
7687 current stack frame.
7690 * Minor command changes
7692 The command ``call func (arg, arg, ...)'' now acts like the print
7693 command, except it does not print or save a value if the function's result
7694 is void. This is similar to dbx usage.
7696 The ``up'' and ``down'' commands now always print the frame they end up
7697 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7698 frames without printing.
7700 * New directory command
7702 'dir' now adds directories to the FRONT of the source search path.
7703 The path starts off empty. Source files that contain debug information
7704 about the directory in which they were compiled can be found even
7705 with an empty path; Sun CC and GCC include this information. If GDB can't
7706 find your source file in the current directory, type "dir .".
7708 * Configuring GDB for compilation
7710 For normal use, type ``./configure host''. See README or gdb.texinfo
7713 GDB now handles cross debugging. If you are remotely debugging between
7714 two different machines, type ``./configure host -target=targ''.
7715 Host is the machine where GDB will run; targ is the machine
7716 where the program that you are debugging will run.