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 * GDB now supports Thread Local Storage (TLS) variables on several
15 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
16 architectures require kernel changes. TLS is not yet supported for
17 amd64 and i386 process core dumps.
19 * Support for Pointer Authentication on AArch64 Linux.
21 * Two new convenience functions $_cimag and $_creal that extract the
22 imaginary and real parts respectively from complex numbers.
24 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
25 provide the exitcode or exit status of the shell commands launched by
26 GDB commands such as "shell", "pipe" and "make".
30 ** The gdb.Value type has a new method 'format_string' which returns a
31 string representing the value. The formatting is controlled by the
32 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
33 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
34 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
36 ** gdb.Type has a new property 'objfile' which returns the objfile the
39 ** The frame information printed by the python frame filtering code
40 is now consistent with what the 'backtrace' command prints when
41 there are no filters, or when the 'backtrace' '-no-filters' option
44 ** The new function gdb.lookup_static_symbol can be used to look up
45 symbols with static linkage.
47 ** gdb.Objfile has new methods 'lookup_global_symbol' and
48 'lookup_static_symbol' to lookup a symbol from this objfile only.
52 | [COMMAND] | SHELL_COMMAND
53 | -d DELIM COMMAND DELIM SHELL_COMMAND
54 pipe [COMMAND] | SHELL_COMMAND
55 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
56 Executes COMMAND and sends its output to SHELL_COMMAND.
57 With no COMMAND, repeat the last executed command
58 and send its output to SHELL_COMMAND.
60 with SETTING [VALUE] [-- COMMAND]
61 w SETTING [VALUE] [-- COMMAND]
62 Temporarily set SETTING, run COMMAND, and restore SETTING.
63 Usage: with SETTING -- COMMAND
64 With no COMMAND, repeats the last executed command.
65 SETTING is any GDB setting you can change with the "set"
66 subcommands. For example, 'with language c -- print someobj'
67 temporarily switches to the C language in order to print someobj.
68 Settings can be combined: 'w lang c -- w print elements unlimited --
69 usercmd' switches to the C language and runs usercmd with no limit
70 of array elements to print.
72 maint with SETTING [VALUE] [-- COMMAND]
73 Like "with", but works with "maintenance set" settings.
75 set may-call-functions [on|off]
76 show may-call-functions
77 This controls whether GDB will attempt to call functions in
78 the program, such as with expressions in the print command. It
79 defaults to on. Calling functions in the program being debugged
80 can have undesired side effects. It is now possible to forbid
81 such function calls. If function calls are forbidden, GDB will throw
82 an error when a command (such as print expression) calls a function
85 set print finish [on|off]
87 This controls whether the `finish' command will display the value
88 that is returned by the current function. When `off', the value is
89 still entered into the value history, but it is not printed. The
94 Allows deeply nested structures to be simplified when printing by
95 replacing deeply nested parts (beyond the max-depth) with ellipses.
96 The default max-depth is 20, but this can be set to unlimited to get
97 the old behavior back.
99 set logging debugredirect [on|off]
100 By default, GDB debug output will go to both the terminal and the logfile.
101 Set if you want debug output to go only to the log file.
103 set style title foreground COLOR
104 set style title background COLOR
105 set style title intensity VALUE
106 Control the styling of titles.
108 set style highlight foreground COLOR
109 set style highlight background COLOR
110 set style highlight intensity VALUE
111 Control the styling of highlightings.
113 maint set test-settings KIND
114 maint show test-settings KIND
115 A set of commands used by the testsuite for exercising the settings
118 set print frame-info [short-location|location|location-and-address
119 |source-and-location|source-line|auto]
120 show print frame-info
121 This controls what frame information is printed by the commands printing
122 a frame. This setting will e.g. influence the behaviour of 'backtrace',
123 'frame', 'stepi'. The python frame filtering also respect this setting.
124 The 'backtrace' '-frame-info' option can override this global setting.
129 The "help" command uses the title style to enhance the
130 readibility of its output by styling the classes and
134 Similarly to "help", the "apropos" command also uses the
135 title style for the command names. "apropos" accepts now
136 a flag "-v" (verbose) to show the full documentation
137 of matching commands and to use the highlight style to mark
138 the documentation parts matching REGEXP.
142 The GDB printf and eval commands can now print C-style and Ada-style
143 string convenience variables without calling functions in the program.
144 This allows to do formatted printing of strings without having
145 a running inferior, or when debugging a core dump.
147 info sources [-dirname | -basename] [--] [REGEXP]
148 This command has now optional arguments to only print the files
149 whose names match REGEXP. The arguments -dirname and -basename
150 allow to restrict matching respectively to the dirname and basename
154 The "show style" and its subcommands are now styling
155 a style name in their output using its own style, to help
156 the user visualize the different styles.
158 set print frame-arguments
159 The new value 'presence' indicates to only indicate the presence of
160 arguments using ..., instead of printing argument names and values.
162 set print raw-frame-arguments
163 show print raw-frame-arguments
165 These commands replace the similarly-named "set/show print raw
166 frame-arguments" commands (now with a dash instead of a space). The
167 old commands are now deprecated and may be removed in a future
170 maint test-options require-delimiter
171 maint test-options unknown-is-error
172 maint test-options unknown-is-operand
173 maint show test-options-completion-result
174 Commands used by the testsuite to validate the command options
177 * New command options, command completion
179 GDB now has a standard infrastructure to support dash-style command
180 options ('-OPT'). One benefit is that commands that use it can
181 easily support completion of command line arguments. Try "CMD
182 -[TAB]" or "help CMD" to find options supported by a command. Over
183 time, we intend to migrate most commands to this infrastructure. A
184 number of commands got support for new command options in this
187 ** The "print" and "compile print" commands now support a number of
188 options that allow overriding relevant global print settings as
189 set by "set print" subcommands:
193 -array-indexes [on|off]
194 -elements NUMBER|unlimited
198 -repeats NUMBER|unlimited
199 -static-members [on|off]
204 Note that because the "print"/"compile print" commands accept
205 arbitrary expressions which may look like options (including
206 abbreviations), if you specify any command option, then you must
207 use a double dash ("--") to mark the end of argument processing.
209 ** The "backtrace" command now supports a number of options that
210 allow overriding relevant global print settings as set by "set
211 backtrace" and "set print" subcommands:
213 -entry-values no|only|preferred|if-needed|both|compact|default
214 -frame-arguments all|scalars|none
215 -raw-frame-arguments [on|off]
216 -frame-info auto|source-line|location|source-and-location
217 |location-and-address|short-location
221 In addition, the full/no-filters/hide qualifiers are now also
222 exposed as command options too:
228 ** The "frame apply", "tfaas" and "faas" commands similarly now
229 support the following options:
234 ** The new "info sources" options -dirname and -basename options
235 are using the standard '-OPT' infrastructure.
237 All options above can also be abbreviated. The argument of boolean
238 (on/off) options can be 0/1 too, and also the argument is assumed
239 "on" if omitted. This allows writing compact command invocations,
242 (gdb) p -r -p -o 0 -- *myptr
244 The above is equivalent to:
246 (gdb) print -raw -pretty -object off -- *myptr
248 ** The "info types" command now supports the '-q' flag to disable
249 printing of some header information in a similar fashion to "info
250 variables" and "info functions".
252 * Completion improvements
254 ** GDB can now complete the options of the "thread apply all" and
255 "taas" commands, and their "-ascending" option can now be
258 ** GDB can now complete the options of the "info threads", "info
259 functions", "info variables", "info locals", and "info args"
262 ** GDB can now complete the options of the "compile file" and
263 "compile code" commands. The "compile file" command now
264 completes on filenames.
266 ** GDB can now complete the backtrace command's
267 "full/no-filters/hide" qualifiers.
269 * In settings, you can now abbreviate "unlimited".
271 E.g., "set print elements u" is now equivalent to "set print
277 This lists all the possible completions for the rest of the line, if it
278 were to be given as a command itself. This is intended for use by MI
279 frontends in cases when separate CLI and MI channels cannot be used.
281 -catch-throw, -catch-rethrow, and -catch-catch
282 These can be used to catch C++ exceptions in a similar fashion to
283 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
287 The testsuite now creates the files gdb.cmd (containing the arguments
288 used to launch GDB) and gdb.in (containing all the commands sent to
289 GDB) in the output directory for each test script. Multiple invocations
290 are appended with .1, .2, .3 etc.
292 * Building GDB and GDBserver now requires GNU make >= 3.82.
294 Using another implementation of the make program or an earlier version of
295 GNU make to build GDB or GDBserver is not supported.
297 *** Changes in GDB 8.3
299 * GDB and GDBserver now support access to additional registers on
300 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
303 * GDB now has experimental support for the compilation and injection of
304 C++ source code into the inferior. This beta release does not include
305 support for several language features, such as templates, constructors,
308 This feature requires GCC 7.1 or higher built with libcp1.so
311 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
312 can be passed using the '[ADDRESS]:PORT' notation, or the regular
313 'ADDRESS:PORT' method.
315 * DWARF index cache: GDB can now automatically save indices of DWARF
316 symbols on disk to speed up further loading of the same binaries.
318 * Ada task switching is now supported on aarch64-elf targets when
319 debugging a program using the Ravenscar Profile. For more information,
320 see the "Tasking Support when using the Ravenscar Profile" section
321 in the GDB user manual.
323 * GDB in batch mode now exits with status 1 if the last command to be
326 * The RISC-V target now supports target descriptions.
328 * System call catchpoints now support system call aliases on FreeBSD.
329 When the ABI of a system call changes in FreeBSD, this is
330 implemented by leaving a compatibility system call using the old ABI
331 at the existing number and allocating a new system call number for
332 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
333 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
334 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
335 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
336 so that a system call catchpoint for the 'kevent' system call will
337 catch invocations of both the 'kevent' and 'freebsd11_kevent'
338 binaries. This ensures that 'kevent' system calls are caught for
339 binaries using either the old or new ABIs.
341 * Terminal styling is now available for the CLI and the TUI. GNU
342 Source Highlight can additionally be used to provide styling of
343 source code snippets. See the "set style" commands, below, for more
346 * Removed support for old demangling styles arm, edg, gnu, hp and
351 set debug compile-cplus-types
352 show debug compile-cplus-types
353 Control the display of debug output about type conversion in the
354 C++ compile feature. Commands have no effect while compiliong
359 Control whether debug output about files/functions skipping is
362 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
363 Apply a command to some frames.
364 FLAG arguments allow to control what output to produce and how to handle
365 errors raised when applying COMMAND to a frame.
368 Apply a command to all threads (ignoring errors and empty output).
369 Shortcut for 'thread apply all -s COMMAND'.
372 Apply a command to all frames (ignoring errors and empty output).
373 Shortcut for 'frame apply all -s COMMAND'.
376 Apply a command to all frames of all threads (ignoring errors and empty
378 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
380 maint set dwarf unwinders (on|off)
381 maint show dwarf unwinders
382 Control whether DWARF unwinders can be used.
385 Display a list of open files for a process.
389 Changes to the "frame", "select-frame", and "info frame" CLI commands.
390 These commands all now take a frame specification which
391 is either a frame level, or one of the keywords 'level', 'address',
392 'function', or 'view' followed by a parameter. Selecting a frame by
393 address, or viewing a frame outside the current backtrace now
394 requires the use of a keyword. Selecting a frame by level is
395 unchanged. The MI comment "-stack-select-frame" is unchanged.
397 target remote FILENAME
398 target extended-remote FILENAME
399 If FILENAME is a Unix domain socket, GDB will attempt to connect
400 to this socket instead of opening FILENAME as a character device.
402 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
403 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
404 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
405 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
406 These commands can now print only the searched entities
407 matching the provided regexp(s), giving a condition
408 on the entity names or entity types. The flag -q disables
409 printing headers or informations messages.
415 These commands now determine the syntax for the shown entities
416 according to the language chosen by `set language'. In particular,
417 `set language auto' means to automatically choose the language of
420 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
421 The 'thread apply' command accepts new FLAG arguments.
422 FLAG arguments allow to control what output to produce and how to handle
423 errors raised when applying COMMAND to a thread.
425 set tui tab-width NCHARS
426 show tui tab-width NCHARS
427 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
429 set style enabled [on|off]
431 Enable or disable terminal styling. Styling is enabled by default
432 on most hosts, but disabled by default when in batch mode.
434 set style sources [on|off]
436 Enable or disable source code styling. Source code styling is
437 enabled by default, but only takes effect if styling in general is
438 enabled, and if GDB was linked with GNU Source Highlight.
440 set style filename foreground COLOR
441 set style filename background COLOR
442 set style filename intensity VALUE
443 Control the styling of file names.
445 set style function foreground COLOR
446 set style function background COLOR
447 set style function intensity VALUE
448 Control the styling of function names.
450 set style variable foreground COLOR
451 set style variable background COLOR
452 set style variable intensity VALUE
453 Control the styling of variable names.
455 set style address foreground COLOR
456 set style address background COLOR
457 set style address intensity VALUE
458 Control the styling of addresses.
462 ** The default version of the MI interpreter is now 3 (-i=mi3).
464 ** The '-data-disassemble' MI command now accepts an '-a' option to
465 disassemble the whole function surrounding the given program
466 counter value or function name. Support for this feature can be
467 verified by using the "-list-features" command, which should
468 contain "data-disassemble-a-option".
470 ** Command responses and notifications that include a frame now include
471 the frame's architecture in a new "arch" attribute.
473 ** The output of information about multi-location breakpoints (which is
474 syntactically incorrect in MI 2) has changed in MI 3. This affects
475 the following commands and events:
479 - =breakpoint-created
480 - =breakpoint-modified
482 The -fix-multi-location-breakpoint-output command can be used to enable
483 this behavior with previous MI versions.
485 * New native configurations
487 GNU/Linux/RISC-V riscv*-*-linux*
488 FreeBSD/riscv riscv*-*-freebsd*
492 GNU/Linux/RISC-V riscv*-*-linux*
494 CSKY GNU/LINUX csky*-*-linux
495 FreeBSD/riscv riscv*-*-freebsd*
497 GNU/Linux/OpenRISC or1k*-*-linux*
501 GDB no longer supports native debugging on versions of MS-Windows
506 ** GDB no longer supports Python versions less than 2.6.
508 ** The gdb.Inferior type has a new 'progspace' property, which is the program
509 space associated to that inferior.
511 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
512 of objfiles associated to that program space.
514 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
515 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
518 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
519 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
520 correct and did not work properly.
522 ** The gdb.Value type has a new constructor, which is used to construct a
523 gdb.Value from a Python buffer object and a gdb.Type.
529 Enable or disable the undefined behavior sanitizer. This is
530 disabled by default, but passing --enable-ubsan=yes or
531 --enable-ubsan=auto to configure will enable it. Enabling this can
532 cause a performance penalty. The undefined behavior sanitizer was
533 first introduced in GCC 4.9.
535 *** Changes in GDB 8.2
537 * The 'set disassembler-options' command now supports specifying options
540 * The 'symbol-file' command now accepts an '-o' option to add a relative
541 offset to all sections.
543 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
544 a relative offset to all sections, but it allows to override the load
545 address of individual sections using '-s'.
547 * The 'add-symbol-file' command no longer requires the second argument
548 (address of the text section).
550 * The endianness used with the 'set endian auto' mode in the absence of
551 an executable selected for debugging is now the last endianness chosen
552 either by one of the 'set endian big' and 'set endian little' commands
553 or by inferring from the last executable used, rather than the startup
556 * The pager now allows a "c" response, meaning to disable the pager
557 for the rest of the current command.
559 * The commands 'info variables/functions/types' now show the source line
560 numbers of symbol definitions when available.
562 * 'info proc' now works on running processes on FreeBSD systems and core
563 files created on FreeBSD systems.
565 * C expressions can now use _Alignof, and C++ expressions can now use
568 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
569 the vector length while the process is running.
575 Control display of debugging info regarding the FreeBSD native target.
577 set|show varsize-limit
578 This new setting allows the user to control the maximum size of Ada
579 objects being printed when those objects have a variable type,
580 instead of that maximum size being hardcoded to 65536 bytes.
582 set|show record btrace cpu
583 Controls the processor to be used for enabling errata workarounds for
586 maint check libthread-db
587 Run integrity checks on the current inferior's thread debugging
590 maint set check-libthread-db (on|off)
591 maint show check-libthread-db
592 Control whether to run integrity checks on inferior specific thread
593 debugging libraries as they are loaded. The default is not to
598 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
600 ** The commands attached to a breakpoint can be set by assigning to
601 the breakpoint's "commands" field.
603 ** gdb.execute can now execute multi-line gdb commands.
605 ** The new functions gdb.convenience_variable and
606 gdb.set_convenience_variable can be used to get and set the value
607 of convenience variables.
609 ** A gdb.Parameter will no longer print the "set" help text on an
610 ordinary "set"; instead by default a "set" will be silent unless
611 the get_set_string method returns a non-empty string.
615 RiscV ELF riscv*-*-elf
617 * Removed targets and native configurations
619 m88k running OpenBSD m88*-*-openbsd*
620 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
621 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
622 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
624 * Aarch64/Linux hardware watchpoints improvements
626 Hardware watchpoints on unaligned addresses are now properly
627 supported when running Linux kernel 4.10 or higher: read and access
628 watchpoints are no longer spuriously missed, and all watchpoints
629 lengths between 1 and 8 bytes are supported. On older kernels,
630 watchpoints set on unaligned addresses are no longer missed, with
631 the tradeoff that there is a possibility of false hits being
636 --enable-codesign=CERT
637 This can be used to invoke "codesign -s CERT" after building gdb.
638 This option is useful on macOS, where code signing is required for
639 gdb to work properly.
641 --disable-gdbcli has been removed
642 This is now silently accepted, but does nothing.
644 *** Changes in GDB 8.1
646 * GDB now supports dynamically creating arbitrary register groups specified
647 in XML target descriptions. This allows for finer grain grouping of
648 registers on systems with a large amount of registers.
650 * The 'ptype' command now accepts a '/o' flag, which prints the
651 offsets and sizes of fields in a struct, like the pahole(1) tool.
653 * New "--readnever" command line option instructs GDB to not read each
654 symbol file's symbolic debug information. This makes startup faster
655 but at the expense of not being able to perform symbolic debugging.
656 This option is intended for use cases where symbolic debugging will
657 not be used, e.g., when you only need to dump the debuggee's core.
659 * GDB now uses the GNU MPFR library, if available, to emulate target
660 floating-point arithmetic during expression evaluation when the target
661 uses different floating-point formats than the host. At least version
662 3.1 of GNU MPFR is required.
664 * GDB now supports access to the guarded-storage-control registers and the
665 software-based guarded-storage broadcast control registers on IBM z14.
667 * On Unix systems, GDB now supports transmitting environment variables
668 that are to be set or unset to GDBserver. These variables will
669 affect the environment to be passed to the remote inferior.
671 To inform GDB of environment variables that are to be transmitted to
672 GDBserver, use the "set environment" command. Only user set
673 environment variables are sent to GDBserver.
675 To inform GDB of environment variables that are to be unset before
676 the remote inferior is started by the GDBserver, use the "unset
677 environment" command.
679 * Completion improvements
681 ** GDB can now complete function parameters in linespecs and
682 explicit locations without quoting. When setting breakpoints,
683 quoting around functions names to help with TAB-completion is
684 generally no longer necessary. For example, this now completes
687 (gdb) b function(in[TAB]
688 (gdb) b function(int)
690 Related, GDB is no longer confused with completing functions in
691 C++ anonymous namespaces:
694 (gdb) b (anonymous namespace)::[TAB][TAB]
695 (anonymous namespace)::a_function()
696 (anonymous namespace)::b_function()
698 ** GDB now has much improved linespec and explicit locations TAB
699 completion support, that better understands what you're
700 completing and offers better suggestions. For example, GDB no
701 longer offers data symbols as possible completions when you're
702 setting a breakpoint.
704 ** GDB now TAB-completes label symbol names.
706 ** The "complete" command now mimics TAB completion accurately.
708 * New command line options (gcore)
711 Dump all memory mappings.
713 * Breakpoints on C++ functions are now set on all scopes by default
715 By default, breakpoints on functions/methods are now interpreted as
716 specifying all functions with the given name ignoring missing
717 leading scopes (namespaces and classes).
719 For example, assuming a C++ program with symbols named:
724 both commands "break func()" and "break B::func()" set a breakpoint
727 You can use the new flag "-qualified" to override this. This makes
728 GDB interpret the specified function name as a complete
729 fully-qualified name instead. For example, using the same C++
730 program, the "break -q B::func" command sets a breakpoint on
731 "B::func", only. A parameter has been added to the Python
732 gdb.Breakpoint constructor to achieve the same result when creating
733 a breakpoint from Python.
735 * Breakpoints on functions marked with C++ ABI tags
737 GDB can now set breakpoints on functions marked with C++ ABI tags
738 (e.g., [abi:cxx11]). See here for a description of ABI tags:
739 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
741 Functions with a C++11 abi tag are demangled/displayed like this:
743 function[abi:cxx11](int)
746 You can now set a breakpoint on such functions simply as if they had
749 (gdb) b function(int)
751 Or if you need to disambiguate between tags, like:
753 (gdb) b function[abi:other_tag](int)
755 Tab completion was adjusted accordingly as well.
759 ** New events gdb.new_inferior, gdb.inferior_deleted, and
760 gdb.new_thread are emitted. See the manual for further
761 description of these.
763 ** A new function, "gdb.rbreak" has been added to the Python API.
764 This function allows the setting of a large number of breakpoints
765 via a regex pattern in Python. See the manual for further details.
767 ** Python breakpoints can now accept explicit locations. See the
768 manual for a further description of this feature.
771 * New features in the GDB remote stub, GDBserver
773 ** GDBserver is now able to start inferior processes with a
774 specified initial working directory.
776 The user can set the desired working directory to be used from
777 GDB using the new "set cwd" command.
779 ** New "--selftest" command line option runs some GDBserver self
780 tests. These self tests are disabled in releases.
782 ** On Unix systems, GDBserver now does globbing expansion and variable
783 substitution in inferior command line arguments.
785 This is done by starting inferiors using a shell, like GDB does.
786 See "set startup-with-shell" in the user manual for how to disable
787 this from GDB when using "target extended-remote". When using
788 "target remote", you can disable the startup with shell by using the
789 new "--no-startup-with-shell" GDBserver command line option.
791 ** On Unix systems, GDBserver now supports receiving environment
792 variables that are to be set or unset from GDB. These variables
793 will affect the environment to be passed to the inferior.
795 * When catching an Ada exception raised with a message, GDB now prints
796 the message in the catchpoint hit notification. In GDB/MI mode, that
797 information is provided as an extra field named "exception-message"
798 in the *stopped notification.
800 * Trait objects can now be inspected When debugging Rust code. This
801 requires compiler support which will appear in Rust 1.24.
805 QEnvironmentHexEncoded
806 Inform GDBserver of an environment variable that is to be passed to
807 the inferior when starting it.
810 Inform GDBserver of an environment variable that is to be unset
811 before starting the remote inferior.
814 Inform GDBserver that the environment should be reset (i.e.,
815 user-set environment variables should be unset).
818 Indicates whether the inferior must be started with a shell or not.
821 Tell GDBserver that the inferior to be started should use a specific
824 * The "maintenance print c-tdesc" command now takes an optional
825 argument which is the file name of XML target description.
827 * The "maintenance selftest" command now takes an optional argument to
828 filter the tests to be run.
830 * The "enable", and "disable" commands now accept a range of
831 breakpoint locations, e.g. "enable 1.3-5".
836 Set and show the current working directory for the inferior.
839 Set and show compilation command used for compiling and injecting code
840 with the 'compile' commands.
842 set debug separate-debug-file
843 show debug separate-debug-file
844 Control the display of debug output about separate debug file search.
846 set dump-excluded-mappings
847 show dump-excluded-mappings
848 Control whether mappings marked with the VM_DONTDUMP flag should be
849 dumped when generating a core file.
852 List the registered selftests.
855 Start the debugged program stopping at the first instruction.
858 Control display of debugging messages related to OpenRISC targets.
860 set|show print type nested-type-limit
861 Set and show the limit of nesting level for nested types that the
862 type printer will show.
864 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
867 * Safer/improved support for debugging with no debug info
869 GDB no longer assumes functions with no debug information return
872 This means that GDB now refuses to call such functions unless you
873 tell it the function's type, by either casting the call to the
874 declared return type, or by casting the function to a function
875 pointer of the right type, and calling that:
877 (gdb) p getenv ("PATH")
878 'getenv' has unknown return type; cast the call to its declared return type
879 (gdb) p (char *) getenv ("PATH")
880 $1 = 0x7fffffffe "/usr/local/bin:/"...
881 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
882 $2 = 0x7fffffffe "/usr/local/bin:/"...
884 Similarly, GDB no longer assumes that global variables with no debug
885 info have type 'int', and refuses to print the variable's value
886 unless you tell it the variable's type:
889 'var' has unknown type; cast it to its declared type
893 * New native configurations
895 FreeBSD/aarch64 aarch64*-*-freebsd*
896 FreeBSD/arm arm*-*-freebsd*
900 FreeBSD/aarch64 aarch64*-*-freebsd*
901 FreeBSD/arm arm*-*-freebsd*
902 OpenRISC ELF or1k*-*-elf
904 * Removed targets and native configurations
906 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
908 *** Changes in GDB 8.0
910 * GDB now supports access to the PKU register on GNU/Linux. The register is
911 added by the Memory Protection Keys for Userspace feature which will be
912 available in future Intel CPUs.
914 * GDB now supports C++11 rvalue references.
918 ** New functions to start, stop and access a running btrace recording.
919 ** Rvalue references are now supported in gdb.Type.
921 * GDB now supports recording and replaying rdrand and rdseed Intel 64
924 * Building GDB and GDBserver now requires a C++11 compiler.
926 For example, GCC 4.8 or later.
928 It is no longer possible to build GDB or GDBserver with a C
929 compiler. The --disable-build-with-cxx configure option has been
932 * Building GDB and GDBserver now requires GNU make >= 3.81.
934 It is no longer supported to build GDB or GDBserver with another
935 implementation of the make program or an earlier version of GNU make.
937 * Native debugging on MS-Windows supports command-line redirection
939 Command-line arguments used for starting programs on MS-Windows can
940 now include redirection symbols supported by native Windows shells,
941 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
942 as "run", "start", and "set args", as well as the corresponding MI
945 * Support for thread names on MS-Windows.
947 GDB now catches and handles the special exception that programs
948 running on MS-Windows use to assign names to threads in the
951 * Support for Java programs compiled with gcj has been removed.
953 * User commands now accept an unlimited number of arguments.
954 Previously, only up to 10 was accepted.
956 * The "eval" command now expands user-defined command arguments.
958 This makes it easier to process a variable number of arguments:
963 eval "print $arg%d", $i
968 * Target descriptions can now describe registers for sparc32 and sparc64.
970 * GDB now supports DWARF version 5 (debug information format).
971 Its .debug_names index is not yet supported.
973 * New native configurations
975 FreeBSD/mips mips*-*-freebsd
979 Synopsys ARC arc*-*-elf32
980 FreeBSD/mips mips*-*-freebsd
982 * Removed targets and native configurations
984 Alpha running FreeBSD alpha*-*-freebsd*
985 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
990 Erases all the flash memory regions reported by the target.
992 maint print arc arc-instruction address
993 Print internal disassembler information about instruction at a given address.
997 set disassembler-options
998 show disassembler-options
999 Controls the passing of target specific information to the disassembler.
1000 If it is necessary to specify more than one disassembler option then
1001 multiple options can be placed together into a comma separated list.
1002 The default value is the empty string. Currently, the only supported
1003 targets are ARM, PowerPC and S/390.
1008 Erases all the flash memory regions reported by the target. This is
1009 equivalent to the CLI command flash-erase.
1011 -file-list-shared-libraries
1012 List the shared libraries in the program. This is
1013 equivalent to the CLI command "info shared".
1016 Catchpoints stopping the program when Ada exceptions are
1017 handled. This is equivalent to the CLI command "catch handlers".
1019 *** Changes in GDB 7.12
1021 * GDB and GDBserver now build with a C++ compiler by default.
1023 The --enable-build-with-cxx configure option is now enabled by
1024 default. One must now explicitly configure with
1025 --disable-build-with-cxx in order to build with a C compiler. This
1026 option will be removed in a future release.
1028 * GDBserver now supports recording btrace without maintaining an active
1031 * GDB now supports a negative repeat count in the 'x' command to examine
1032 memory backward from the given address. For example:
1035 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1036 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1037 (gdb) x/-5i 0x0000000000400580
1038 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1039 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1040 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1041 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1042 0x40057b <main(int, char**)+25>:
1043 callq 0x400536 <Func1(int, char const*)>
1045 * Fortran: Support structures with fields of dynamic types and
1046 arrays of dynamic types.
1048 * The symbol dumping maintenance commands have new syntax.
1049 maint print symbols [-pc address] [--] [filename]
1050 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1051 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1052 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1053 maint print msymbols [-objfile objfile] [--] [filename]
1055 * GDB now supports multibit bitfields and enums in target register
1058 * New Python-based convenience function $_as_string(val), which returns
1059 the textual representation of a value. This function is especially
1060 useful to obtain the text label of an enum value.
1062 * Intel MPX bound violation handling.
1064 Segmentation faults caused by a Intel MPX boundary violation
1065 now display the kind of violation (upper or lower), the memory
1066 address accessed and the memory bounds, along with the usual
1067 signal received and code location.
1071 Program received signal SIGSEGV, Segmentation fault
1072 Upper bound violation while accessing address 0x7fffffffc3b3
1073 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1074 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1076 * Rust language support.
1077 GDB now supports debugging programs written in the Rust programming
1078 language. See https://www.rust-lang.org/ for more information about
1081 * Support for running interpreters on specified input/output devices
1083 GDB now supports a new mechanism that allows frontends to provide
1084 fully featured GDB console views, as a better alternative to
1085 building such views on top of the "-interpreter-exec console"
1086 command. See the new "new-ui" command below. With that command,
1087 frontends can now start GDB in the traditional command-line mode
1088 running in an embedded terminal emulator widget, and create a
1089 separate MI interpreter running on a specified i/o device. In this
1090 way, GDB handles line editing, history, tab completion, etc. in the
1091 console all by itself, and the GUI uses the separate MI interpreter
1092 for its own control and synchronization, invisible to the command
1095 * The "catch syscall" command catches groups of related syscalls.
1097 The "catch syscall" command now supports catching a group of related
1098 syscalls using the 'group:' or 'g:' prefix.
1103 skip -gfile file-glob-pattern
1104 skip -function function
1105 skip -rfunction regular-expression
1106 A generalized form of the skip command, with new support for
1107 glob-style file names and regular expressions for function names.
1108 Additionally, a file spec and a function spec may now be combined.
1110 maint info line-table REGEXP
1111 Display the contents of GDB's internal line table data struture.
1114 Run any GDB unit tests that were compiled in.
1117 Start a new user interface instance running INTERP as interpreter,
1118 using the TTY file for input/output.
1122 ** gdb.Breakpoint objects have a new attribute "pending", which
1123 indicates whether the breakpoint is pending.
1124 ** Three new breakpoint-related events have been added:
1125 gdb.breakpoint_created, gdb.breakpoint_modified, and
1126 gdb.breakpoint_deleted.
1128 signal-event EVENTID
1129 Signal ("set") the given MS-Windows event object. This is used in
1130 conjunction with the Windows JIT debugging (AeDebug) support, where
1131 the OS suspends a crashing process until a debugger can attach to
1132 it. Resuming the crashing process, in order to debug it, is done by
1133 signalling an event.
1135 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1136 was added in GDBserver, including JIT compiling fast tracepoint's
1137 conditional expression bytecode into native code.
1139 * Support for various remote target protocols and ROM monitors has
1142 target m32rsdi Remote M32R debugging over SDI
1143 target mips MIPS remote debugging protocol
1144 target pmon PMON ROM monitor
1145 target ddb NEC's DDB variant of PMON for Vr4300
1146 target rockhopper NEC RockHopper variant of PMON
1147 target lsi LSI variant of PMO
1149 * Support for tracepoints and fast tracepoints on powerpc-linux,
1150 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1151 including JIT compiling fast tracepoint's conditional expression
1152 bytecode into native code.
1154 * MI async record =record-started now includes the method and format used for
1155 recording. For example:
1157 =record-started,thread-group="i1",method="btrace",format="bts"
1159 * MI async record =thread-selected now includes the frame field. For example:
1161 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1165 Andes NDS32 nds32*-*-elf
1167 *** Changes in GDB 7.11
1169 * GDB now supports debugging kernel-based threads on FreeBSD.
1171 * Per-inferior thread numbers
1173 Thread numbers are now per inferior instead of global. If you're
1174 debugging multiple inferiors, GDB displays thread IDs using a
1175 qualified INF_NUM.THR_NUM form. For example:
1179 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1180 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1181 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1182 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1184 As consequence, thread numbers as visible in the $_thread
1185 convenience variable and in Python's InferiorThread.num attribute
1186 are no longer unique between inferiors.
1188 GDB now maintains a second thread ID per thread, referred to as the
1189 global thread ID, which is the new equivalent of thread numbers in
1190 previous releases. See also $_gthread below.
1192 For backwards compatibility, MI's thread IDs always refer to global
1195 * Commands that accept thread IDs now accept the qualified
1196 INF_NUM.THR_NUM form as well. For example:
1199 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1202 * In commands that accept a list of thread IDs, you can now refer to
1203 all threads of an inferior using a star wildcard. GDB accepts
1204 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1205 refer to all threads of the current inferior. For example, "info
1208 * You can use "info threads -gid" to display the global thread ID of
1211 * The new convenience variable $_gthread holds the global number of
1214 * The new convenience variable $_inferior holds the number of the
1217 * GDB now displays the ID and name of the thread that hit a breakpoint
1218 or received a signal, if your program is multi-threaded. For
1221 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1222 Thread 1 "main" received signal SIGINT, Interrupt.
1224 * Record btrace now supports non-stop mode.
1226 * Support for tracepoints on aarch64-linux was added in GDBserver.
1228 * The 'record instruction-history' command now indicates speculative execution
1229 when using the Intel Processor Trace recording format.
1231 * GDB now allows users to specify explicit locations, bypassing
1232 the linespec parser. This feature is also available to GDB/MI
1235 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1236 GDB now is able to debug both AArch64 applications and ARM applications
1239 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1240 including JIT compiling fast tracepoint's conditional expression bytecode
1243 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1245 * "info threads", "info inferiors", "info display", "info checkpoints"
1246 and "maint info program-spaces" now list the corresponding items in
1247 ascending ID order, for consistency with all other "info" commands.
1249 * In Ada, the overloads selection menu has been enhanced to display the
1250 parameter types and the return types for the matching overloaded subprograms.
1254 maint set target-non-stop (on|off|auto)
1255 maint show target-non-stop
1256 Control whether GDB targets always operate in non-stop mode even if
1257 "set non-stop" is "off". The default is "auto", meaning non-stop
1258 mode is enabled if supported by the target.
1260 maint set bfd-sharing
1261 maint show bfd-sharing
1262 Control the reuse of bfd objects.
1265 show debug bfd-cache
1266 Control display of debugging info regarding bfd caching.
1270 Control display of debugging info regarding FreeBSD threads.
1272 set remote multiprocess-extensions-packet
1273 show remote multiprocess-extensions-packet
1274 Set/show the use of the remote protocol multiprocess extensions.
1276 set remote thread-events
1277 show remote thread-events
1278 Set/show the use of thread create/exit events.
1280 set ada print-signatures on|off
1281 show ada print-signatures"
1282 Control whether parameter types and return types are displayed in overloads
1283 selection menus. It is activaled (@code{on}) by default.
1287 Controls the maximum size of memory, in bytes, that GDB will
1288 allocate for value contents. Prevents incorrect programs from
1289 causing GDB to allocate overly large buffers. Default is 64k.
1291 * The "disassemble" command accepts a new modifier: /s.
1292 It prints mixed source+disassembly like /m with two differences:
1293 - disassembled instructions are now printed in program order, and
1294 - and source for all relevant files is now printed.
1295 The "/m" option is now considered deprecated: its "source-centric"
1296 output hasn't proved useful in practice.
1298 * The "record instruction-history" command accepts a new modifier: /s.
1299 It behaves exactly like /m and prints mixed source+disassembly.
1301 * The "set scheduler-locking" command supports a new mode "replay".
1302 It behaves like "off" in record mode and like "on" in replay mode.
1304 * Support for various ROM monitors has been removed:
1306 target dbug dBUG ROM monitor for Motorola ColdFire
1307 target picobug Motorola picobug monitor
1308 target dink32 DINK32 ROM monitor for PowerPC
1309 target m32r Renesas M32R/D ROM monitor
1310 target mon2000 mon2000 ROM monitor
1311 target ppcbug PPCBUG ROM monitor for PowerPC
1313 * Support for reading/writing memory and extracting values on architectures
1314 whose memory is addressable in units of any integral multiple of 8 bits.
1317 Allows to break when an Ada exception is handled.
1319 * New remote packets
1322 Indicates that an exec system call was executed.
1324 exec-events feature in qSupported
1325 The qSupported packet allows GDB to request support for exec
1326 events using the new 'gdbfeature' exec-event, and the qSupported
1327 response can contain the corresponding 'stubfeature'. Set and
1328 show commands can be used to display whether these features are enabled.
1331 Equivalent to interrupting with the ^C character, but works in
1334 thread created stop reason (T05 create:...)
1335 Indicates that the thread was just created and is stopped at entry.
1337 thread exit stop reply (w exitcode;tid)
1338 Indicates that the thread has terminated.
1341 Enables/disables thread create and exit event reporting. For
1342 example, this is used in non-stop mode when GDB stops a set of
1343 threads and synchronously waits for the their corresponding stop
1344 replies. Without exit events, if one of the threads exits, GDB
1345 would hang forever not knowing that it should no longer expect a
1346 stop for that same thread.
1349 Indicates that there are no resumed threads left in the target (all
1350 threads are stopped). The remote stub reports support for this stop
1351 reply to GDB's qSupported query.
1354 Enables/disables catching syscalls from the inferior process.
1355 The remote stub reports support for this packet to GDB's qSupported query.
1357 syscall_entry stop reason
1358 Indicates that a syscall was just called.
1360 syscall_return stop reason
1361 Indicates that a syscall just returned.
1363 * Extended-remote exec events
1365 ** GDB now has support for exec events on extended-remote Linux targets.
1366 For such targets with Linux kernels 2.5.46 and later, this enables
1367 follow-exec-mode and exec catchpoints.
1369 set remote exec-event-feature-packet
1370 show remote exec-event-feature-packet
1371 Set/show the use of the remote exec event feature.
1373 * Thread names in remote protocol
1375 The reply to qXfer:threads:read may now include a name attribute for each
1378 * Target remote mode fork and exec events
1380 ** GDB now has support for fork and exec events on target remote mode
1381 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1382 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1383 fork and exec catchpoints.
1385 * Remote syscall events
1387 ** GDB now has support for catch syscall on remote Linux targets,
1388 currently enabled on x86/x86_64 architectures.
1390 set remote catch-syscall-packet
1391 show remote catch-syscall-packet
1392 Set/show the use of the remote catch syscall feature.
1396 ** The -var-set-format command now accepts the zero-hexadecimal
1397 format. It outputs data in hexadecimal format with zero-padding on the
1402 ** gdb.InferiorThread objects have a new attribute "global_num",
1403 which refers to the thread's global thread ID. The existing
1404 "num" attribute now refers to the thread's per-inferior number.
1405 See "Per-inferior thread numbers" above.
1406 ** gdb.InferiorThread objects have a new attribute "inferior", which
1407 is the Inferior object the thread belongs to.
1409 *** Changes in GDB 7.10
1411 * Support for process record-replay and reverse debugging on aarch64*-linux*
1412 targets has been added. GDB now supports recording of A64 instruction set
1413 including advance SIMD instructions.
1415 * Support for Sun's version of the "stabs" debug file format has been removed.
1417 * GDB now honors the content of the file /proc/PID/coredump_filter
1418 (PID is the process ID) on GNU/Linux systems. This file can be used
1419 to specify the types of memory mappings that will be included in a
1420 corefile. For more information, please refer to the manual page of
1421 "core(5)". GDB also has a new command: "set use-coredump-filter
1422 on|off". It allows to set whether GDB will read the content of the
1423 /proc/PID/coredump_filter file when generating a corefile.
1425 * The "info os" command on GNU/Linux can now display information on
1427 "info os cpus" Listing of all cpus/cores on the system
1429 * GDB has two new commands: "set serial parity odd|even|none" and
1430 "show serial parity". These allows to set or show parity for the
1433 * The "info source" command now displays the producer string if it was
1434 present in the debug info. This typically includes the compiler version
1435 and may include things like its command line arguments.
1437 * The "info dll", an alias of the "info sharedlibrary" command,
1438 is now available on all platforms.
1440 * Directory names supplied to the "set sysroot" commands may be
1441 prefixed with "target:" to tell GDB to access shared libraries from
1442 the target system, be it local or remote. This replaces the prefix
1443 "remote:". The default sysroot has been changed from "" to
1444 "target:". "remote:" is automatically converted to "target:" for
1445 backward compatibility.
1447 * The system root specified by "set sysroot" will be prepended to the
1448 filename of the main executable (if reported to GDB as absolute by
1449 the operating system) when starting processes remotely, and when
1450 attaching to already-running local or remote processes.
1452 * GDB now supports automatic location and retrieval of executable
1453 files from remote targets. Remote debugging can now be initiated
1454 using only a "target remote" or "target extended-remote" command
1455 (no "set sysroot" or "file" commands are required). See "New remote
1458 * The "dump" command now supports verilog hex format.
1460 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1462 * On GNU/Linux, GDB and gdbserver are now able to access executable
1463 and shared library files without a "set sysroot" command when
1464 attaching to processes running in different mount namespaces from
1465 the debugger. This makes it possible to attach to processes in
1466 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1467 See "New remote packets" below.
1469 * The "tui reg" command now provides completion for all of the
1470 available register groups, including target specific groups.
1472 * The HISTSIZE environment variable is no longer read when determining
1473 the size of GDB's command history. GDB now instead reads the dedicated
1474 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1475 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1480 ** Memory ports can now be unbuffered.
1484 ** gdb.Objfile objects have a new attribute "username",
1485 which is the name of the objfile as specified by the user,
1486 without, for example, resolving symlinks.
1487 ** You can now write frame unwinders in Python.
1488 ** gdb.Type objects have a new method "optimized_out",
1489 returning optimized out gdb.Value instance of this type.
1490 ** gdb.Value objects have new methods "reference_value" and
1491 "const_value" which return a reference to the value and a
1492 "const" version of the value respectively.
1496 maint print symbol-cache
1497 Print the contents of the symbol cache.
1499 maint print symbol-cache-statistics
1500 Print statistics of symbol cache usage.
1502 maint flush-symbol-cache
1503 Flush the contents of the symbol cache.
1507 Start branch trace recording using Branch Trace Store (BTS) format.
1510 Evaluate expression by using the compiler and print result.
1514 Explicit commands for enabling and disabling tui mode.
1517 set mpx bound on i386 and amd64
1518 Support for bound table investigation on Intel MPX enabled applications.
1522 Start branch trace recording using Intel Processor Trace format.
1525 Print information about branch tracing internals.
1527 maint btrace packet-history
1528 Print the raw branch tracing data.
1530 maint btrace clear-packet-history
1531 Discard the stored raw branch tracing data.
1534 Discard all branch tracing data. It will be fetched and processed
1535 anew by the next "record" command.
1540 Renamed from "set debug dwarf2-die".
1541 show debug dwarf-die
1542 Renamed from "show debug dwarf2-die".
1544 set debug dwarf-read
1545 Renamed from "set debug dwarf2-read".
1546 show debug dwarf-read
1547 Renamed from "show debug dwarf2-read".
1549 maint set dwarf always-disassemble
1550 Renamed from "maint set dwarf2 always-disassemble".
1551 maint show dwarf always-disassemble
1552 Renamed from "maint show dwarf2 always-disassemble".
1554 maint set dwarf max-cache-age
1555 Renamed from "maint set dwarf2 max-cache-age".
1556 maint show dwarf max-cache-age
1557 Renamed from "maint show dwarf2 max-cache-age".
1559 set debug dwarf-line
1560 show debug dwarf-line
1561 Control display of debugging info regarding DWARF line processing.
1564 show max-completions
1565 Set the maximum number of candidates to be considered during
1566 completion. The default value is 200. This limit allows GDB
1567 to avoid generating large completion lists, the computation of
1568 which can cause the debugger to become temporarily unresponsive.
1570 set history remove-duplicates
1571 show history remove-duplicates
1572 Control the removal of duplicate history entries.
1574 maint set symbol-cache-size
1575 maint show symbol-cache-size
1576 Control the size of the symbol cache.
1578 set|show record btrace bts buffer-size
1579 Set and show the size of the ring buffer used for branch tracing in
1581 The obtained size may differ from the requested size. Use "info
1582 record" to see the obtained buffer size.
1584 set debug linux-namespaces
1585 show debug linux-namespaces
1586 Control display of debugging info regarding Linux namespaces.
1588 set|show record btrace pt buffer-size
1589 Set and show the size of the ring buffer used for branch tracing in
1590 Intel Processor Trace format.
1591 The obtained size may differ from the requested size. Use "info
1592 record" to see the obtained buffer size.
1594 maint set|show btrace pt skip-pad
1595 Set and show whether PAD packets are skipped when computing the
1598 * The command 'thread apply all' can now support new option '-ascending'
1599 to call its specified command for all threads in ascending order.
1601 * Python/Guile scripting
1603 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1604 special section named `.debug_gdb_scripts'.
1606 * New remote packets
1608 qXfer:btrace-conf:read
1609 Return the branch trace configuration for the current thread.
1611 Qbtrace-conf:bts:size
1612 Set the requested ring buffer size for branch tracing in BTS format.
1615 Enable Intel Procesor Trace-based branch tracing for the current
1616 process. The remote stub reports support for this packet to GDB's
1619 Qbtrace-conf:pt:size
1620 Set the requested ring buffer size for branch tracing in Intel Processor
1624 Indicates a memory breakpoint instruction was executed, irrespective
1625 of whether it was GDB that planted the breakpoint or the breakpoint
1626 is hardcoded in the program. This is required for correct non-stop
1630 Indicates the target stopped for a hardware breakpoint. This is
1631 required for correct non-stop mode operation.
1634 Return information about files on the remote system.
1636 qXfer:exec-file:read
1637 Return the full absolute name of the file that was executed to
1638 create a process running on the remote system.
1641 Select the filesystem on which vFile: operations with filename
1642 arguments will operate. This is required for GDB to be able to
1643 access files on remote targets where the remote stub does not
1644 share a common filesystem with the inferior(s).
1647 Indicates that a fork system call was executed.
1650 Indicates that a vfork system call was executed.
1652 vforkdone stop reason
1653 Indicates that a vfork child of the specified process has executed
1654 an exec or exit, allowing the vfork parent to resume execution.
1656 fork-events and vfork-events features in qSupported
1657 The qSupported packet allows GDB to request support for fork and
1658 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1659 and the qSupported response can contain the corresponding
1660 'stubfeatures'. Set and show commands can be used to display
1661 whether these features are enabled.
1663 * Extended-remote fork events
1665 ** GDB now has support for fork events on extended-remote Linux
1666 targets. For targets with Linux kernels 2.5.60 and later, this
1667 enables follow-fork-mode and detach-on-fork for both fork and
1668 vfork, as well as fork and vfork catchpoints.
1670 * The info record command now shows the recording format and the
1671 branch tracing configuration for the current thread when using
1672 the btrace record target.
1673 For the BTS format, it shows the ring buffer size.
1675 * GDB now has support for DTrace USDT (Userland Static Defined
1676 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1678 * GDB now supports access to vector registers on S/390 GNU/Linux
1681 * Removed command line options
1683 -xdb HP-UX XDB compatibility mode.
1685 * Removed targets and native configurations
1687 HP/PA running HP-UX hppa*-*-hpux*
1688 Itanium running HP-UX ia64-*-hpux*
1690 * New configure options
1693 This configure option allows the user to build GDB with support for
1694 Intel Processor Trace (default: auto). This requires libipt.
1696 --with-libipt-prefix=PATH
1697 Specify the path to the version of libipt that GDB should use.
1698 $PATH/include should contain the intel-pt.h header and
1699 $PATH/lib should contain the libipt.so library.
1701 *** Changes in GDB 7.9.1
1705 ** Xmethods can now specify a result type.
1707 *** Changes in GDB 7.9
1709 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1713 ** You can now access frame registers from Python scripts.
1714 ** New attribute 'producer' for gdb.Symtab objects.
1715 ** gdb.Objfile objects have a new attribute "progspace",
1716 which is the gdb.Progspace object of the containing program space.
1717 ** gdb.Objfile objects have a new attribute "owner".
1718 ** gdb.Objfile objects have a new attribute "build_id",
1719 which is the build ID generated when the file was built.
1720 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1721 ** A new event "gdb.clear_objfiles" has been added, triggered when
1722 selecting a new file to debug.
1723 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1724 ** New function gdb.lookup_objfile.
1726 New events which are triggered when GDB modifies the state of the
1729 ** gdb.events.inferior_call_pre: Function call is about to be made.
1730 ** gdb.events.inferior_call_post: Function call has just been made.
1731 ** gdb.events.memory_changed: A memory location has been altered.
1732 ** gdb.events.register_changed: A register has been altered.
1734 * New Python-based convenience functions:
1736 ** $_caller_is(name [, number_of_frames])
1737 ** $_caller_matches(regexp [, number_of_frames])
1738 ** $_any_caller_is(name [, number_of_frames])
1739 ** $_any_caller_matches(regexp [, number_of_frames])
1741 * GDB now supports the compilation and injection of source code into
1742 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1743 to compile the source code to object code, and if successful, inject
1744 and execute that code within the current context of the inferior.
1745 Currently the C language is supported. The commands used to
1746 interface with this new feature are:
1748 compile code [-raw|-r] [--] [source code]
1749 compile file [-raw|-r] filename
1753 demangle [-l language] [--] name
1754 Demangle "name" in the specified language, or the current language
1755 if elided. This command is renamed from the "maint demangle" command.
1756 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1757 as "maint demangler-warning".
1759 queue-signal signal-name-or-number
1760 Queue a signal to be delivered to the thread when it is resumed.
1762 add-auto-load-scripts-directory directory
1763 Add entries to the list of directories from which to load auto-loaded
1766 maint print user-registers
1767 List all currently available "user" registers.
1769 compile code [-r|-raw] [--] [source code]
1770 Compile, inject, and execute in the inferior the executable object
1771 code produced by compiling the provided source code.
1773 compile file [-r|-raw] filename
1774 Compile and inject into the inferior the executable object code
1775 produced by compiling the source code stored in the filename
1778 * On resume, GDB now always passes the signal the program had stopped
1779 for to the thread the signal was sent to, even if the user changed
1780 threads before resuming. Previously GDB would often (but not
1781 always) deliver the signal to the thread that happens to be current
1784 * Conversely, the "signal" command now consistently delivers the
1785 requested signal to the current thread. GDB now asks for
1786 confirmation if the program had stopped for a signal and the user
1787 switched threads meanwhile.
1789 * "breakpoint always-inserted" modes "off" and "auto" merged.
1791 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1792 won't remove breakpoints from the target until all threads stop,
1793 even in non-stop mode. The "auto" mode has been removed, and "off"
1794 is now the default mode.
1798 set debug symbol-lookup
1799 show debug symbol-lookup
1800 Control display of debugging info regarding symbol lookup.
1804 ** The -list-thread-groups command outputs an exit-code field for
1805 inferiors that have exited.
1809 MIPS SDE mips*-sde*-elf*
1813 Support for these obsolete configurations has been removed.
1815 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1816 SGI Irix-5.x mips-*-irix5*
1817 SGI Irix-6.x mips-*-irix6*
1818 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1819 VAX running Ultrix vax-*-ultrix*
1821 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1822 and "assf"), have been removed. Use the "sharedlibrary" command, or
1823 its alias "share", instead.
1825 *** Changes in GDB 7.8
1827 * New command line options
1830 This is an alias for the --data-directory option.
1832 * GDB supports printing and modifying of variable length automatic arrays
1833 as specified in ISO C99.
1835 * The ARM simulator now supports instruction level tracing
1836 with or without disassembly.
1840 GDB now has support for scripting using Guile. Whether this is
1841 available is determined at configure time.
1842 Guile version 2.0 or greater is required.
1843 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1845 * New commands (for set/show, see "New options" below)
1849 Invoke CODE by passing it to the Guile interpreter.
1853 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1855 info auto-load guile-scripts [regexp]
1856 Print the list of automatically loaded Guile scripts.
1858 * The source command is now capable of sourcing Guile scripts.
1859 This feature is dependent on the debugger being built with Guile support.
1863 set print symbol-loading (off|brief|full)
1864 show print symbol-loading
1865 Control whether to print informational messages when loading symbol
1866 information for a file. The default is "full", but when debugging
1867 programs with large numbers of shared libraries the amount of output
1868 becomes less useful.
1870 set guile print-stack (none|message|full)
1871 show guile print-stack
1872 Show a stack trace when an error is encountered in a Guile script.
1874 set auto-load guile-scripts (on|off)
1875 show auto-load guile-scripts
1876 Control auto-loading of Guile script files.
1878 maint ada set ignore-descriptive-types (on|off)
1879 maint ada show ignore-descriptive-types
1880 Control whether the debugger should ignore descriptive types in Ada
1881 programs. The default is not to ignore the descriptive types. See
1882 the user manual for more details on descriptive types and the intended
1883 usage of this option.
1885 set auto-connect-native-target
1887 Control whether GDB is allowed to automatically connect to the
1888 native target for the run, attach, etc. commands when not connected
1889 to any target yet. See also "target native" below.
1891 set record btrace replay-memory-access (read-only|read-write)
1892 show record btrace replay-memory-access
1893 Control what memory accesses are allowed during replay.
1895 maint set target-async (on|off)
1896 maint show target-async
1897 This controls whether GDB targets operate in synchronous or
1898 asynchronous mode. Normally the default is asynchronous, if it is
1899 available; but this can be changed to more easily debug problems
1900 occurring only in synchronous mode.
1902 set mi-async (on|off)
1904 Control whether MI asynchronous mode is preferred. This supersedes
1905 "set target-async" of previous GDB versions.
1907 * "set target-async" is deprecated as a CLI option and is now an alias
1908 for "set mi-async" (only puts MI into async mode).
1910 * Background execution commands (e.g., "c&", "s&", etc.) are now
1911 possible ``out of the box'' if the target supports them. Previously
1912 the user would need to explicitly enable the possibility with the
1913 "set target-async on" command.
1915 * New features in the GDB remote stub, GDBserver
1917 ** New option --debug-format=option1[,option2,...] allows one to add
1918 additional text to each output. At present only timestamps
1919 are supported: --debug-format=timestamps.
1920 Timestamps can also be turned on with the
1921 "monitor set debug-format timestamps" command from GDB.
1923 * The 'record instruction-history' command now starts counting instructions
1924 at one. This also affects the instruction ranges reported by the
1925 'record function-call-history' command when given the /i modifier.
1927 * The command 'record function-call-history' supports a new modifier '/c' to
1928 indent the function names based on their call stack depth.
1929 The fields for the '/i' and '/l' modifier have been reordered.
1930 The source line range is now prefixed with 'at'.
1931 The instruction range is now prefixed with 'inst'.
1932 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1933 "record instruction-history" and "list" commands.
1935 * The ranges given as arguments to the 'record function-call-history' and
1936 'record instruction-history' commands are now inclusive.
1938 * The btrace record target now supports the 'record goto' command.
1939 For locations inside the execution trace, the back trace is computed
1940 based on the information stored in the execution trace.
1942 * The btrace record target supports limited reverse execution and replay.
1943 The target does not record data and therefore does not allow reading
1944 memory or registers.
1946 * The "catch syscall" command now works on s390*-linux* targets.
1948 * The "compare-sections" command is no longer specific to target
1949 remote. It now works with all targets.
1951 * All native targets are now consistently called "native".
1952 Consequently, the "target child", "target GNU", "target djgpp",
1953 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1954 commands have been replaced with "target native". The QNX/NTO port
1955 leaves the "procfs" target in place and adds a "native" target for
1956 consistency with other ports. The impact on users should be minimal
1957 as these commands previously either throwed an error, or were
1958 no-ops. The target's name is visible in the output of the following
1959 commands: "help target", "info target", "info files", "maint print
1962 * The "target native" command now connects to the native target. This
1963 can be used to launch native programs even when "set
1964 auto-connect-native-target" is set to off.
1966 * GDB now supports access to Intel MPX registers on GNU/Linux.
1968 * Support for Intel AVX-512 registers on GNU/Linux.
1969 Support displaying and modifying Intel AVX-512 registers
1970 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1972 * New remote packets
1974 qXfer:btrace:read's annex
1975 The qXfer:btrace:read packet supports a new annex 'delta' to read
1976 branch trace incrementally.
1980 ** Valid Python operations on gdb.Value objects representing
1981 structs/classes invoke the corresponding overloaded operators if
1983 ** New `Xmethods' feature in the Python API. Xmethods are
1984 additional methods or replacements for existing methods of a C++
1985 class. This feature is useful for those cases where a method
1986 defined in C++ source code could be inlined or optimized out by
1987 the compiler, making it unavailable to GDB.
1990 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1992 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1993 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1994 its alias "share", instead.
1996 * The commands "set remotebaud" and "show remotebaud" are no longer
1997 supported. Use "set serial baud" and "show serial baud" (respectively)
2002 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2003 target-async". The latter is left as a deprecated alias of the
2004 former for backward compatibility. If the target supports it,
2005 CLI background execution commands are now always possible by
2006 default, independently of whether the frontend stated a
2007 preference for asynchronous execution with "-gdb-set mi-async".
2008 Previously "-gdb-set target-async off" affected both MI execution
2009 commands and CLI execution commands.
2011 *** Changes in GDB 7.7
2013 * Improved support for process record-replay and reverse debugging on
2014 arm*-linux* targets. Support for thumb32 and syscall instruction
2015 recording has been added.
2017 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2019 * GDB now supports Fission DWP file format version 2.
2020 http://gcc.gnu.org/wiki/DebugFission
2022 * New convenience function "$_isvoid", to check whether an expression
2023 is void. A void expression is an expression where the type of the
2024 result is "void". For example, some convenience variables may be
2025 "void" when evaluated (e.g., "$_exitcode" before the execution of
2026 the program being debugged; or an undefined convenience variable).
2027 Another example, when calling a function whose return type is
2030 * The "maintenance print objfiles" command now takes an optional regexp.
2032 * The "catch syscall" command now works on arm*-linux* targets.
2034 * GDB now consistently shows "<not saved>" when printing values of
2035 registers the debug info indicates have not been saved in the frame
2036 and there's nowhere to retrieve them from
2037 (callee-saved/call-clobbered registers):
2042 (gdb) info registers rax
2045 Before, the former would print "<optimized out>", and the latter
2046 "*value not available*".
2048 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2053 ** Frame filters and frame decorators have been added.
2054 ** Temporary breakpoints are now supported.
2055 ** Line tables representation has been added.
2056 ** New attribute 'parent_type' for gdb.Field objects.
2057 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2058 ** New attribute 'name' for gdb.Type objects.
2062 Nios II ELF nios2*-*-elf
2063 Nios II GNU/Linux nios2*-*-linux
2064 Texas Instruments MSP430 msp430*-*-elf
2066 * Removed native configurations
2068 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2069 been removed. ELF variants of these configurations are kept supported.
2071 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2072 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2073 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2074 i[34567]86-*-openbsd3.[0-3]
2075 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2076 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2077 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2081 Like "catch throw", but catches a re-thrown exception.
2082 maint check-psymtabs
2083 Renamed from old "maint check-symtabs".
2085 Perform consistency checks on symtabs.
2086 maint expand-symtabs
2087 Expand symtabs matching an optional regexp.
2090 Display the details of GDB configure-time options.
2092 maint set|show per-command
2093 maint set|show per-command space
2094 maint set|show per-command time
2095 maint set|show per-command symtab
2096 Enable display of per-command gdb resource usage.
2098 remove-symbol-file FILENAME
2099 remove-symbol-file -a ADDRESS
2100 Remove a symbol file added via add-symbol-file. The file to remove
2101 can be identified by its filename or by an address that lies within
2102 the boundaries of this symbol file in memory.
2105 info exceptions REGEXP
2106 Display the list of Ada exceptions defined in the program being
2107 debugged. If provided, only the exceptions whose names match REGEXP
2112 set debug symfile off|on
2114 Control display of debugging info regarding reading symbol files and
2115 symbol tables within those files
2117 set print raw frame-arguments
2118 show print raw frame-arguments
2119 Set/show whether to print frame arguments in raw mode,
2120 disregarding any defined pretty-printers.
2122 set remote trace-status-packet
2123 show remote trace-status-packet
2124 Set/show the use of remote protocol qTStatus packet.
2128 Control display of debugging messages related to Nios II targets.
2132 Control whether target-assisted range stepping is enabled.
2134 set startup-with-shell
2135 show startup-with-shell
2136 Specifies whether Unix child processes are started via a shell or
2141 Use the target memory cache for accesses to the code segment. This
2142 improves performance of remote debugging (particularly disassembly).
2144 * You can now use a literal value 'unlimited' for options that
2145 interpret 0 or -1 as meaning "unlimited". E.g., "set
2146 trace-buffer-size unlimited" is now an alias for "set
2147 trace-buffer-size -1" and "set height unlimited" is now an alias for
2150 * The "set debug symtab-create" debugging option of GDB has been changed to
2151 accept a verbosity level. 0 means "off", 1 provides basic debugging
2152 output, and values of 2 or greater provides more verbose output.
2154 * New command-line options
2156 Display the details of GDB configure-time options.
2158 * The command 'tsave' can now support new option '-ctf' to save trace
2159 buffer in Common Trace Format.
2161 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2164 * GDB now implements the the C++ 'typeid' operator.
2166 * The new convenience variable $_exception holds the exception being
2167 thrown or caught at an exception-related catchpoint.
2169 * The exception-related catchpoints, like "catch throw", now accept a
2170 regular expression which can be used to filter exceptions by type.
2172 * The new convenience variable $_exitsignal is automatically set to
2173 the terminating signal number when the program being debugged dies
2174 due to an uncaught signal.
2178 ** All MI commands now accept an optional "--language" option.
2179 Support for this feature can be verified by using the "-list-features"
2180 command, which should contain "language-option".
2182 ** The new command -info-gdb-mi-command allows the user to determine
2183 whether a GDB/MI command is supported or not.
2185 ** The "^error" result record returned when trying to execute an undefined
2186 GDB/MI command now provides a variable named "code" whose content is the
2187 "undefined-command" error code. Support for this feature can be verified
2188 by using the "-list-features" command, which should contain
2189 "undefined-command-error-code".
2191 ** The -trace-save MI command can optionally save trace buffer in Common
2194 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2196 ** The command -data-list-register-values now accepts an optional
2197 "--skip-unavailable" option. When used, only the available registers
2200 ** The new command -trace-frame-collected dumps collected variables,
2201 computed expressions, tvars, memory and registers in a traceframe.
2203 ** The commands -stack-list-locals, -stack-list-arguments and
2204 -stack-list-variables now accept an option "--skip-unavailable".
2205 When used, only the available locals or arguments are displayed.
2207 ** The -exec-run command now accepts an optional "--start" option.
2208 When used, the command follows the same semantics as the "start"
2209 command, stopping the program's execution at the start of its
2210 main subprogram. Support for this feature can be verified using
2211 the "-list-features" command, which should contain
2212 "exec-run-start-option".
2214 ** The new commands -catch-assert and -catch-exceptions insert
2215 catchpoints stopping the program when Ada exceptions are raised.
2217 ** The new command -info-ada-exceptions provides the equivalent of
2218 the new "info exceptions" command.
2220 * New system-wide configuration scripts
2221 A GDB installation now provides scripts suitable for use as system-wide
2222 configuration scripts for the following systems:
2226 * GDB now supports target-assigned range stepping with remote targets.
2227 This improves the performance of stepping source lines by reducing
2228 the number of control packets from/to GDB. See "New remote packets"
2231 * GDB now understands the element 'tvar' in the XML traceframe info.
2232 It has the id of the collected trace state variables.
2234 * On S/390 targets that provide the transactional-execution feature,
2235 the program interruption transaction diagnostic block (TDB) is now
2236 represented as a number of additional "registers" in GDB.
2238 * New remote packets
2242 The vCont packet supports a new 'r' action, that tells the remote
2243 stub to step through an address range itself, without GDB
2244 involvemement at each single-step.
2246 qXfer:libraries-svr4:read's annex
2247 The previously unused annex of the qXfer:libraries-svr4:read packet
2248 is now used to support passing an argument list. The remote stub
2249 reports support for this argument list to GDB's qSupported query.
2250 The defined arguments are "start" and "prev", used to reduce work
2251 necessary for library list updating, resulting in significant
2254 * New features in the GDB remote stub, GDBserver
2256 ** GDBserver now supports target-assisted range stepping. Currently
2257 enabled on x86/x86_64 GNU/Linux targets.
2259 ** GDBserver now adds element 'tvar' in the XML in the reply to
2260 'qXfer:traceframe-info:read'. It has the id of the collected
2261 trace state variables.
2263 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2266 * New 'z' formatter for printing and examining memory, this displays the
2267 value as hexadecimal zero padded on the left to the size of the type.
2269 * GDB can now use Windows x64 unwinding data.
2271 * The "set remotebaud" command has been replaced by "set serial baud".
2272 Similarly, "show remotebaud" has been replaced by "show serial baud".
2273 The "set remotebaud" and "show remotebaud" commands are still available
2274 to provide backward compatibility with older versions of GDB.
2276 *** Changes in GDB 7.6
2278 * Target record has been renamed to record-full.
2279 Record/replay is now enabled with the "record full" command.
2280 This also affects settings that are associated with full record/replay
2281 that have been moved from "set/show record" to "set/show record full":
2283 set|show record full insn-number-max
2284 set|show record full stop-at-limit
2285 set|show record full memory-query
2287 * A new record target "record-btrace" has been added. The new target
2288 uses hardware support to record the control-flow of a process. It
2289 does not support replaying the execution, but it implements the
2290 below new commands for investigating the recorded execution log.
2291 This new recording method can be enabled using:
2295 The "record-btrace" target is only available on Intel Atom processors
2296 and requires a Linux kernel 2.6.32 or later.
2298 * Two new commands have been added for record/replay to give information
2299 about the recorded execution without having to replay the execution.
2300 The commands are only supported by "record btrace".
2302 record instruction-history prints the execution history at
2303 instruction granularity
2305 record function-call-history prints the execution history at
2306 function granularity
2308 * New native configurations
2310 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2311 FreeBSD/powerpc powerpc*-*-freebsd
2312 x86_64/Cygwin x86_64-*-cygwin*
2313 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2317 ARM AArch64 aarch64*-*-elf
2318 ARM AArch64 GNU/Linux aarch64*-*-linux
2319 Lynx 178 PowerPC powerpc-*-lynx*178
2320 x86_64/Cygwin x86_64-*-cygwin*
2321 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2323 * If the configured location of system.gdbinit file (as given by the
2324 --with-system-gdbinit option at configure time) is in the
2325 data-directory (as specified by --with-gdb-datadir at configure
2326 time) or in one of its subdirectories, then GDB will look for the
2327 system-wide init file in the directory specified by the
2328 --data-directory command-line option.
2330 * New command line options:
2332 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2333 other initialization files, unlike -nx which disables all of them.
2335 * Removed command line options
2337 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2340 * The 'ptype' and 'whatis' commands now accept an argument to control
2343 * 'info proc' now works on some core files.
2347 ** Vectors can be created with gdb.Type.vector.
2349 ** Python's atexit.register now works in GDB.
2351 ** Types can be pretty-printed via a Python API.
2353 ** Python 3 is now supported (in addition to Python 2.4 or later)
2355 ** New class gdb.Architecture exposes GDB's internal representation
2356 of architecture in the Python API.
2358 ** New method Frame.architecture returns the gdb.Architecture object
2359 corresponding to the frame's architecture.
2361 * New Python-based convenience functions:
2363 ** $_memeq(buf1, buf2, length)
2364 ** $_streq(str1, str2)
2366 ** $_regex(str, regex)
2368 * The 'cd' command now defaults to using '~' (the home directory) if not
2371 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2372 default for GCC since November 2000.
2374 * The command 'forward-search' can now be abbreviated as 'fo'.
2376 * The command 'info tracepoints' can now display 'installed on target'
2377 or 'not installed on target' for each non-pending location of tracepoint.
2379 * New configure options
2381 --enable-libmcheck/--disable-libmcheck
2382 By default, development versions are built with -lmcheck on hosts
2383 that support it, in order to help track memory corruption issues.
2384 Release versions, on the other hand, are built without -lmcheck
2385 by default. The --enable-libmcheck/--disable-libmcheck configure
2386 options allow the user to override that default.
2387 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2388 This configure option allows the user to build GDB with
2389 libbabeltrace using which GDB can read Common Trace Format data.
2391 * New commands (for set/show, see "New options" below)
2394 Catch signals. This is similar to "handle", but allows commands and
2395 conditions to be attached.
2398 List the BFDs known to GDB.
2400 python-interactive [command]
2402 Start a Python interactive prompt, or evaluate the optional command
2403 and print the result of expressions.
2406 "py" is a new alias for "python".
2408 enable type-printer [name]...
2409 disable type-printer [name]...
2410 Enable or disable type printers.
2414 ** For the Renesas Super-H architecture, the "regs" command has been removed
2415 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2420 set print type methods (on|off)
2421 show print type methods
2422 Control whether method declarations are displayed by "ptype".
2423 The default is to show them.
2425 set print type typedefs (on|off)
2426 show print type typedefs
2427 Control whether typedef definitions are displayed by "ptype".
2428 The default is to show them.
2430 set filename-display basename|relative|absolute
2431 show filename-display
2432 Control the way in which filenames is displayed.
2433 The default is "relative", which preserves previous behavior.
2435 set trace-buffer-size
2436 show trace-buffer-size
2437 Request target to change the size of trace buffer.
2439 set remote trace-buffer-size-packet auto|on|off
2440 show remote trace-buffer-size-packet
2441 Control the use of the remote protocol `QTBuffer:size' packet.
2445 Control display of debugging messages related to ARM AArch64.
2448 set debug coff-pe-read
2449 show debug coff-pe-read
2450 Control display of debugging messages related to reading of COFF/PE
2455 Control display of debugging messages related to Mach-O symbols
2458 set debug notification
2459 show debug notification
2460 Control display of debugging info for async remote notification.
2464 ** Command parameter changes are now notified using new async record
2465 "=cmd-param-changed".
2466 ** Trace frame changes caused by command "tfind" are now notified using
2467 new async record "=traceframe-changed".
2468 ** The creation, deletion and modification of trace state variables
2469 are now notified using new async records "=tsv-created",
2470 "=tsv-deleted" and "=tsv-modified".
2471 ** The start and stop of process record are now notified using new
2472 async record "=record-started" and "=record-stopped".
2473 ** Memory changes are now notified using new async record
2475 ** The data-disassemble command response will include a "fullname" field
2476 containing the absolute file name when source has been requested.
2477 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2478 command, to allow pattern filling of memory areas.
2479 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2480 library load/unload events.
2481 ** The response to breakpoint commands and breakpoint async records
2482 includes an "installed" field containing a boolean state about each
2483 non-pending tracepoint location is whether installed on target or not.
2484 ** Output of the "-trace-status" command includes a "trace-file" field
2485 containing the name of the trace file being examined. This field is
2486 optional, and only present when examining a trace file.
2487 ** The "fullname" field is now always present along with the "file" field,
2488 even if the file cannot be found by GDB.
2490 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2491 You must have the LZMA library available when configuring GDB for this
2492 feature to be enabled. For more information, see:
2493 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2495 * New remote packets
2498 Set the size of trace buffer. The remote stub reports support for this
2499 packet to gdb's qSupported query.
2502 Enable Branch Trace Store (BTS)-based branch tracing for the current
2503 thread. The remote stub reports support for this packet to gdb's
2507 Disable branch tracing for the current thread. The remote stub reports
2508 support for this packet to gdb's qSupported query.
2511 Read the traced branches for the current thread. The remote stub
2512 reports support for this packet to gdb's qSupported query.
2514 *** Changes in GDB 7.5
2516 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2517 for more x32 ABI info.
2519 * GDB now supports access to MIPS DSP registers on Linux targets.
2521 * GDB now supports debugging microMIPS binaries.
2523 * The "info os" command on GNU/Linux can now display information on
2524 several new classes of objects managed by the operating system:
2525 "info os procgroups" lists process groups
2526 "info os files" lists file descriptors
2527 "info os sockets" lists internet-domain sockets
2528 "info os shm" lists shared-memory regions
2529 "info os semaphores" lists semaphores
2530 "info os msg" lists message queues
2531 "info os modules" lists loaded kernel modules
2533 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2534 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2535 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2536 options and inspect the probe arguments using the new $_probe_arg family
2537 of convenience variables. You can obtain more information about SystemTap
2538 in <http://sourceware.org/systemtap/>.
2540 * GDB now supports reversible debugging on ARM, it allows you to
2541 debug basic ARM and THUMB instructions, and provides
2542 record/replay support.
2544 * The option "symbol-reloading" has been deleted as it is no longer used.
2548 ** GDB commands implemented in Python can now be put in command class
2551 ** The "maint set python print-stack on|off" is now deleted.
2553 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2554 apply "flag enum"-style pretty-printing to any enum.
2556 ** gdb.lookup_symbol can now work when there is no current frame.
2558 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2559 the source at which the symbol was defined.
2561 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2562 method 'value'. The former indicates whether the symbol needs a
2563 frame in order to compute its value, and the latter computes the
2566 ** A new method 'referenced_value' on gdb.Value objects which can
2567 dereference pointer as well as C++ reference values.
2569 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2570 which return the global and static blocks (as gdb.Block objects),
2571 of the underlying symbol table, respectively.
2573 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2574 object associated with a PC value.
2576 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2577 of the address range occupied by code for the current source line.
2579 * Go language support.
2580 GDB now supports debugging programs written in the Go programming
2583 * GDBserver now supports stdio connections.
2584 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2586 * The binary "gdbtui" can no longer be built or installed.
2587 Use "gdb -tui" instead.
2589 * GDB will now print "flag" enums specially. A flag enum is one where
2590 all the enumerator values have no bits in common when pairwise
2591 "and"ed. When printing a value whose type is a flag enum, GDB will
2592 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2593 (gdb) print (enum E) 3
2596 * The filename part of a linespec will now match trailing components
2597 of a source file name. For example, "break gcc/expr.c:1000" will
2598 now set a breakpoint in build/gcc/expr.c, but not
2599 build/libcpp/expr.c.
2601 * The "info proc" and "generate-core-file" commands will now also
2602 work on remote targets connected to GDBserver on Linux.
2604 * The command "info catch" has been removed. It has been disabled
2605 since December 2007.
2607 * The "catch exception" and "catch assert" commands now accept
2608 a condition at the end of the command, much like the "break"
2609 command does. For instance:
2611 (gdb) catch exception Constraint_Error if Barrier = True
2613 Previously, it was possible to add a condition to such catchpoints,
2614 but it had to be done as a second step, after the catchpoint had been
2615 created, using the "condition" command.
2617 * The "info static-tracepoint-marker" command will now also work on
2618 native Linux targets with in-process agent.
2620 * GDB can now set breakpoints on inlined functions.
2622 * The .gdb_index section has been updated to include symbols for
2623 inlined functions. GDB will ignore older .gdb_index sections by
2624 default, which could cause symbol files to be loaded more slowly
2625 until their .gdb_index sections can be recreated. The new command
2626 "set use-deprecated-index-sections on" will cause GDB to use any older
2627 .gdb_index sections it finds. This will restore performance, but the
2628 ability to set breakpoints on inlined functions will be lost in symbol
2629 files with older .gdb_index sections.
2631 The .gdb_index section has also been updated to record more information
2632 about each symbol. This speeds up the "info variables", "info functions"
2633 and "info types" commands when used with programs having the .gdb_index
2634 section, as well as speeding up debugging with shared libraries using
2635 the .gdb_index section.
2637 * Ada support for GDB/MI Variable Objects has been added.
2639 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2644 ** New command -info-os is the MI equivalent of "info os".
2646 ** Output logs ("set logging" and related) now include MI output.
2650 ** "set use-deprecated-index-sections on|off"
2651 "show use-deprecated-index-sections on|off"
2652 Controls the use of deprecated .gdb_index sections.
2654 ** "catch load" and "catch unload" can be used to stop when a shared
2655 library is loaded or unloaded, respectively.
2657 ** "enable count" can be used to auto-disable a breakpoint after
2660 ** "info vtbl" can be used to show the virtual method tables for
2661 C++ and Java objects.
2663 ** "explore" and its sub commands "explore value" and "explore type"
2664 can be used to recursively explore values and types of
2665 expressions. These commands are available only if GDB is
2666 configured with '--with-python'.
2668 ** "info auto-load" shows status of all kinds of auto-loaded files,
2669 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2670 sequences of commands files, "info auto-load python-scripts"
2671 shows status of auto-loading Python script files,
2672 "info auto-load local-gdbinit" shows status of loading init file
2673 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2674 status of inferior specific thread debugging shared library loading.
2676 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2677 and "show auto-load-scripts" commands have been deprecated, use their
2678 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2679 and "show auto-load python-scripts" counterparts instead.
2681 ** "dprintf location,format,args..." creates a dynamic printf, which
2682 is basically a breakpoint that does a printf and immediately
2683 resumes your program's execution, so it is like a printf that you
2684 can insert dynamically at runtime instead of at compiletime.
2686 ** "set print symbol"
2688 Controls whether GDB attempts to display the symbol, if any,
2689 corresponding to addresses it prints. This defaults to "on", but
2690 you can set it to "off" to restore GDB's previous behavior.
2692 * Deprecated commands
2694 ** For the Renesas Super-H architecture, the "regs" command has been
2695 deprecated, and "info all-registers" should be used instead.
2699 Renesas RL78 rl78-*-elf
2700 HP OpenVMS ia64 ia64-hp-openvms*
2702 * GDBserver supports evaluation of breakpoint conditions. When
2703 support is advertised by GDBserver, GDB may be told to send the
2704 breakpoint conditions in bytecode form to GDBserver. GDBserver
2705 will only report the breakpoint trigger to GDB when its condition
2710 set mips compression
2711 show mips compression
2712 Select the compressed ISA encoding used in functions that have no symbol
2713 information available. The encoding can be set to either of:
2716 and is updated automatically from ELF file flags if available.
2718 set breakpoint condition-evaluation
2719 show breakpoint condition-evaluation
2720 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2721 GDBserver ("target"). Default option "auto" chooses the most efficient
2723 This option can improve debugger efficiency depending on the speed of the
2727 Disable auto-loading globally.
2730 Show auto-loading setting of all kinds of auto-loaded files.
2732 set auto-load gdb-scripts on|off
2733 show auto-load gdb-scripts
2734 Control auto-loading of GDB canned sequences of commands files.
2736 set auto-load python-scripts on|off
2737 show auto-load python-scripts
2738 Control auto-loading of Python script files.
2740 set auto-load local-gdbinit on|off
2741 show auto-load local-gdbinit
2742 Control loading of init file (.gdbinit) from current directory.
2744 set auto-load libthread-db on|off
2745 show auto-load libthread-db
2746 Control auto-loading of inferior specific thread debugging shared library.
2748 set auto-load scripts-directory <dir1>[:<dir2>...]
2749 show auto-load scripts-directory
2750 Set a list of directories from which to load auto-loaded scripts.
2751 Automatically loaded Python scripts and GDB scripts are located in one
2752 of the directories listed by this option.
2753 The delimiter (':' above) may differ according to the host platform.
2755 set auto-load safe-path <dir1>[:<dir2>...]
2756 show auto-load safe-path
2757 Set a list of directories from which it is safe to auto-load files.
2758 The delimiter (':' above) may differ according to the host platform.
2760 set debug auto-load on|off
2761 show debug auto-load
2762 Control display of debugging info for auto-loading the files above.
2764 set dprintf-style gdb|call|agent
2766 Control the way in which a dynamic printf is performed; "gdb"
2767 requests a GDB printf command, while "call" causes dprintf to call a
2768 function in the inferior. "agent" requests that the target agent
2769 (such as GDBserver) do the printing.
2771 set dprintf-function <expr>
2772 show dprintf-function
2773 set dprintf-channel <expr>
2774 show dprintf-channel
2775 Set the function and optional first argument to the call when using
2776 the "call" style of dynamic printf.
2778 set disconnected-dprintf on|off
2779 show disconnected-dprintf
2780 Control whether agent-style dynamic printfs continue to be in effect
2781 after GDB disconnects.
2783 * New configure options
2785 --with-auto-load-dir
2786 Configure default value for the 'set auto-load scripts-directory'
2787 setting above. It defaults to '$debugdir:$datadir/auto-load',
2788 $debugdir representing global debugging info directories (available
2789 via 'show debug-file-directory') and $datadir representing GDB's data
2790 directory (available via 'show data-directory').
2792 --with-auto-load-safe-path
2793 Configure default value for the 'set auto-load safe-path' setting
2794 above. It defaults to the --with-auto-load-dir setting.
2796 --without-auto-load-safe-path
2797 Set 'set auto-load safe-path' to '/', effectively disabling this
2800 * New remote packets
2802 z0/z1 conditional breakpoints extension
2804 The z0/z1 breakpoint insertion packets have been extended to carry
2805 a list of conditional expressions over to the remote stub depending on the
2806 condition evaluation mode. The use of this extension can be controlled
2807 via the "set remote conditional-breakpoints-packet" command.
2811 Specify the signals which the remote stub may pass to the debugged
2812 program without GDB involvement.
2814 * New command line options
2816 --init-command=FILE, -ix Like --command, -x but execute it
2817 before loading inferior.
2818 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2819 execute it before loading inferior.
2821 *** Changes in GDB 7.4
2823 * GDB now handles ambiguous linespecs more consistently; the existing
2824 FILE:LINE support has been expanded to other types of linespecs. A
2825 breakpoint will now be set on all matching locations in all
2826 inferiors, and locations will be added or removed according to
2829 * GDB now allows you to skip uninteresting functions and files when
2830 stepping with the "skip function" and "skip file" commands.
2832 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2833 and "show remote hardware-watchpoint-length-limit". These allows to
2834 set or show the maximum length limit (in bytes) of a remote
2835 target hardware watchpoint.
2837 This allows e.g. to use "unlimited" hardware watchpoints with the
2838 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2839 watchpoints are slower than real hardware watchpoints but are
2840 significantly faster than gdb software watchpoints.
2844 ** The register_pretty_printer function in module gdb.printing now takes
2845 an optional `replace' argument. If True, the new printer replaces any
2848 ** The "maint set python print-stack on|off" command has been
2849 deprecated and will be deleted in GDB 7.5.
2850 A new command: "set python print-stack none|full|message" has
2851 replaced it. Additionally, the default for "print-stack" is
2852 now "message", which just prints the error message without
2855 ** A prompt substitution hook (prompt_hook) is now available to the
2858 ** A new Python module, gdb.prompt has been added to the GDB Python
2859 modules library. This module provides functionality for
2860 escape sequences in prompts (used by set/show
2861 extended-prompt). These escape sequences are replaced by their
2862 corresponding value.
2864 ** Python commands and convenience-functions located in
2865 'data-directory'/python/gdb/command and
2866 'data-directory'/python/gdb/function are now automatically loaded
2869 ** Blocks now provide four new attributes. global_block and
2870 static_block will return the global and static blocks
2871 respectively. is_static and is_global are boolean attributes
2872 that indicate if the block is one of those two types.
2874 ** Symbols now provide the "type" attribute, the type of the symbol.
2876 ** The "gdb.breakpoint" function has been deprecated in favor of
2879 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2880 of a function. This class is based on the "finish" command
2881 available in the CLI.
2883 ** Type objects for struct and union types now allow access to
2884 the fields using standard Python dictionary (mapping) methods.
2885 For example, "some_type['myfield']" now works, as does
2886 "some_type.items()".
2888 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2891 ** A new function, "deep_items" has been added to the gdb.types
2892 module in the GDB Python modules library. This function returns
2893 an iterator over the fields of a struct or union type. Unlike
2894 the standard Python "iteritems" method, it will recursively traverse
2895 any anonymous fields.
2899 ** "*stopped" events can report several new "reason"s, such as
2902 ** Breakpoint changes are now notified using new async records, like
2903 "=breakpoint-modified".
2905 ** New command -ada-task-info.
2907 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2908 $sdir specifies the default system locations of shared libraries.
2909 $pdir specifies the directory where the libpthread used by the application
2912 GDB no longer looks in $sdir and $pdir after it has searched the directories
2913 mentioned in libthread-db-search-path. If you want to search those
2914 directories, they must be specified in libthread-db-search-path.
2915 The default value of libthread-db-search-path on GNU/Linux and Solaris
2916 systems is now "$sdir:$pdir".
2918 $pdir is not supported by gdbserver, it is currently ignored.
2919 $sdir is supported by gdbserver.
2921 * New configure option --with-iconv-bin.
2922 When using the internationalization support like the one in the GNU C
2923 library, GDB will invoke the "iconv" program to get a list of supported
2924 character sets. If this program lives in a non-standard location, one can
2925 use this option to specify where to find it.
2927 * When natively debugging programs on PowerPC BookE processors running
2928 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2929 watchpoints, which specify a mask in addition to an address to watch.
2930 The mask specifies that some bits of an address (the bits which are
2931 reset in the mask) should be ignored when matching the address accessed
2932 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2933 section in the user manual for more details.
2935 * The new option --once causes GDBserver to stop listening for connections once
2936 the first connection is made. The listening port used by GDBserver will
2937 become available after that.
2939 * New commands "info macros" and "alias" have been added.
2941 * New function parameters suffix @entry specifies value of function parameter
2942 at the time the function got called. Entry values are available only since
2948 "!" is now an alias of the "shell" command.
2949 Note that no space is needed between "!" and SHELL COMMAND.
2953 watch EXPRESSION mask MASK_VALUE
2954 The watch command now supports the mask argument which allows creation
2955 of masked watchpoints, if the current architecture supports this feature.
2957 info auto-load-scripts [REGEXP]
2958 This command was formerly named "maintenance print section-scripts".
2959 It is now generally useful and is no longer a maintenance-only command.
2961 info macro [-all] [--] MACRO
2962 The info macro command has new options `-all' and `--'. The first for
2963 printing all definitions of a macro. The second for explicitly specifying
2964 the end of arguments and the beginning of the macro name in case the macro
2965 name starts with a hyphen.
2967 collect[/s] EXPRESSIONS
2968 The tracepoint collect command now takes an optional modifier "/s"
2969 that directs it to dereference pointer-to-character types and
2970 collect the bytes of memory up to a zero byte. The behavior is
2971 similar to what you see when you use the regular print command on a
2972 string. An optional integer following the "/s" sets a bound on the
2973 number of bytes that will be collected.
2976 The trace start command now interprets any supplied arguments as a
2977 note to be recorded with the trace run, with an effect similar to
2978 setting the variable trace-notes.
2981 The trace stop command now interprets any arguments as a note to be
2982 mentioned along with the tstatus report that the trace was stopped
2983 with a command. The effect is similar to setting the variable
2986 * Tracepoints can now be enabled and disabled at any time after a trace
2987 experiment has been started using the standard "enable" and "disable"
2988 commands. It is now possible to start a trace experiment with no enabled
2989 tracepoints; GDB will display a warning, but will allow the experiment to
2990 begin, assuming that tracepoints will be enabled as needed while the trace
2993 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2994 locations with 4-byte instructions, when they were previously
2995 limited to locations with instructions of 5 bytes or longer.
2999 set debug dwarf2-read
3000 show debug dwarf2-read
3001 Turns on or off display of debugging messages related to reading
3002 DWARF debug info. The default is off.
3004 set debug symtab-create
3005 show debug symtab-create
3006 Turns on or off display of debugging messages related to symbol table
3007 creation. The default is off.
3010 show extended-prompt
3011 Set the GDB prompt, and allow escape sequences to be inserted to
3012 display miscellaneous information (see 'help set extended-prompt'
3013 for the list of sequences). This prompt (and any information
3014 accessed through the escape sequences) is updated every time the
3015 prompt is displayed.
3017 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3018 show print entry-values
3019 Set printing of frame argument values at function entry. In some cases
3020 GDB can determine the value of function argument which was passed by the
3021 function caller, even if the value was modified inside the called function.
3023 set debug entry-values
3024 show debug entry-values
3025 Control display of debugging info for determining frame argument values at
3026 function entry and virtual tail call frames.
3028 set basenames-may-differ
3029 show basenames-may-differ
3030 Set whether a source file may have multiple base names.
3031 (A "base name" is the name of a file with the directory part removed.
3032 Example: The base name of "/home/user/hello.c" is "hello.c".)
3033 If set, GDB will canonicalize file names (e.g., expand symlinks)
3034 before comparing them. Canonicalization is an expensive operation,
3035 but it allows the same file be known by more than one base name.
3036 If not set (the default), all source files are assumed to have just
3037 one base name, and gdb will do file name comparisons more efficiently.
3043 Set a user name and notes for the current and any future trace runs.
3044 This is useful for long-running and/or disconnected traces, to
3045 inform others (or yourself) as to who is running the trace, supply
3046 contact information, or otherwise explain what is going on.
3048 set trace-stop-notes
3049 show trace-stop-notes
3050 Set a note attached to the trace run, that is displayed when the
3051 trace has been stopped by a tstop command. This is useful for
3052 instance as an explanation, if you are stopping a trace run that was
3053 started by someone else.
3055 * New remote packets
3059 Dynamically enable a tracepoint in a started trace experiment.
3063 Dynamically disable a tracepoint in a started trace experiment.
3067 Set the user and notes of the trace run.
3071 Query the current status of a tracepoint.
3075 Query the minimum length of instruction at which a fast tracepoint may
3078 * Dcache size (number of lines) and line-size are now runtime-configurable
3079 via "set dcache line" and "set dcache line-size" commands.
3083 Texas Instruments TMS320C6x tic6x-*-*
3087 Renesas RL78 rl78-*-elf
3089 *** Changes in GDB 7.3.1
3091 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3093 *** Changes in GDB 7.3
3095 * GDB has a new command: "thread find [REGEXP]".
3096 It finds the thread id whose name, target id, or thread extra info
3097 matches the given regular expression.
3099 * The "catch syscall" command now works on mips*-linux* targets.
3101 * The -data-disassemble MI command now supports modes 2 and 3 for
3102 dumping the instruction opcodes.
3104 * New command line options
3106 -data-directory DIR Specify DIR as the "data-directory".
3107 This is mostly for testing purposes.
3109 * The "maint set python auto-load on|off" command has been renamed to
3110 "set auto-load-scripts on|off".
3112 * GDB has a new command: "set directories".
3113 It is like the "dir" command except that it replaces the
3114 source path list instead of augmenting it.
3116 * GDB now understands thread names.
3118 On GNU/Linux, "info threads" will display the thread name as set by
3119 prctl or pthread_setname_np.
3121 There is also a new command, "thread name", which can be used to
3122 assign a name internally for GDB to display.
3125 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3126 has been integrated into GDB.
3130 ** The function gdb.Write now accepts an optional keyword 'stream'.
3131 This keyword, when provided, will direct the output to either
3132 stdout, stderr, or GDB's logging output.
3134 ** Parameters can now be be sub-classed in Python, and in particular
3135 you may implement the get_set_doc and get_show_doc functions.
3136 This improves how Parameter set/show documentation is processed
3137 and allows for more dynamic content.
3139 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3140 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3141 have an is_valid method.
3143 ** Breakpoints can now be sub-classed in Python, and in particular
3144 you may implement a 'stop' function that is executed each time
3145 the inferior reaches that breakpoint.
3147 ** New function gdb.lookup_global_symbol looks up a global symbol.
3149 ** GDB values in Python are now callable if the value represents a
3150 function. For example, if 'some_value' represents a function that
3151 takes two integer parameters and returns a value, you can call
3152 that function like so:
3154 result = some_value (10,20)
3156 ** Module gdb.types has been added.
3157 It contains a collection of utilities for working with gdb.Types objects:
3158 get_basic_type, has_field, make_enum_dict.
3160 ** Module gdb.printing has been added.
3161 It contains utilities for writing and registering pretty-printers.
3162 New classes: PrettyPrinter, SubPrettyPrinter,
3163 RegexpCollectionPrettyPrinter.
3164 New function: register_pretty_printer.
3166 ** New commands "info pretty-printers", "enable pretty-printer" and
3167 "disable pretty-printer" have been added.
3169 ** gdb.parameter("directories") is now available.
3171 ** New function gdb.newest_frame returns the newest frame in the
3174 ** The gdb.InferiorThread class has a new "name" attribute. This
3175 holds the thread's name.
3177 ** Python Support for Inferior events.
3178 Python scripts can add observers to be notified of events
3179 occurring in the process being debugged.
3180 The following events are currently supported:
3181 - gdb.events.cont Continue event.
3182 - gdb.events.exited Inferior exited event.
3183 - gdb.events.stop Signal received, and Breakpoint hit events.
3187 ** GDB now puts template parameters in scope when debugging in an
3188 instantiation. For example, if you have:
3190 template<int X> int func (void) { return X; }
3192 then if you step into func<5>, "print X" will show "5". This
3193 feature requires proper debuginfo support from the compiler; it
3194 was added to GCC 4.5.
3196 ** The motion commands "next", "finish", "until", and "advance" now
3197 work better when exceptions are thrown. In particular, GDB will
3198 no longer lose control of the inferior; instead, the GDB will
3199 stop the inferior at the point at which the exception is caught.
3200 This functionality requires a change in the exception handling
3201 code that was introduced in GCC 4.5.
3203 * GDB now follows GCC's rules on accessing volatile objects when
3204 reading or writing target state during expression evaluation.
3205 One notable difference to prior behavior is that "print x = 0"
3206 no longer generates a read of x; the value of the assignment is
3207 now always taken directly from the value being assigned.
3209 * GDB now has some support for using labels in the program's source in
3210 linespecs. For instance, you can use "advance label" to continue
3211 execution to a label.
3213 * GDB now has support for reading and writing a new .gdb_index
3214 section. This section holds a fast index of DWARF debugging
3215 information and can be used to greatly speed up GDB startup and
3216 operation. See the documentation for `save gdb-index' for details.
3218 * The "watch" command now accepts an optional "-location" argument.
3219 When used, this causes GDB to watch the memory referred to by the
3220 expression. Such a watchpoint is never deleted due to it going out
3223 * GDB now supports thread debugging of core dumps on GNU/Linux.
3225 GDB now activates thread debugging using the libthread_db library
3226 when debugging GNU/Linux core dumps, similarly to when debugging
3227 live processes. As a result, when debugging a core dump file, GDB
3228 is now able to display pthread_t ids of threads. For example, "info
3229 threads" shows the same output as when debugging the process when it
3230 was live. In earlier releases, you'd see something like this:
3233 * 1 LWP 6780 main () at main.c:10
3235 While now you see this:
3238 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3240 It is also now possible to inspect TLS variables when debugging core
3243 When debugging a core dump generated on a machine other than the one
3244 used to run GDB, you may need to point GDB at the correct
3245 libthread_db library with the "set libthread-db-search-path"
3246 command. See the user manual for more details on this command.
3248 * When natively debugging programs on PowerPC BookE processors running
3249 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3250 which stop execution of the inferior whenever it executes an instruction
3251 at any address within the specified range. See the "PowerPC Embedded"
3252 section in the user manual for more details.
3254 * New features in the GDB remote stub, GDBserver
3256 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3257 and i686 LynxOS (version 5.x).
3259 ** GDBserver is now supported on Blackfin Linux.
3261 * New native configurations
3263 ia64 HP-UX ia64-*-hpux*
3267 Analog Devices, Inc. Blackfin Processor bfin-*
3269 * Ada task switching is now supported on sparc-elf targets when
3270 debugging a program using the Ravenscar Profile. For more information,
3271 see the "Tasking Support when using the Ravenscar Profile" section
3272 in the GDB user manual.
3274 * Guile support was removed.
3276 * New features in the GNU simulator
3278 ** The --map-info flag lists all known core mappings.
3280 ** CFI flashes may be simulated via the "cfi" device.
3282 *** Changes in GDB 7.2
3284 * Shared library support for remote targets by default
3286 When GDB is configured for a generic, non-OS specific target, like
3287 for example, --target=arm-eabi or one of the many *-*-elf targets,
3288 GDB now queries remote stubs for loaded shared libraries using the
3289 `qXfer:libraries:read' packet. Previously, shared library support
3290 was always disabled for such configurations.
3294 ** Argument Dependent Lookup (ADL)
3296 In C++ ADL lookup directs function search to the namespaces of its
3297 arguments even if the namespace has not been imported.
3307 Here the compiler will search for `foo' in the namespace of 'b'
3308 and find A::foo. GDB now supports this. This construct is commonly
3309 used in the Standard Template Library for operators.
3311 ** Improved User Defined Operator Support
3313 In addition to member operators, GDB now supports lookup of operators
3314 defined in a namespace and imported with a `using' directive, operators
3315 defined in the global scope, operators imported implicitly from an
3316 anonymous namespace, and the ADL operators mentioned in the previous
3318 GDB now also supports proper overload resolution for all the previously
3319 mentioned flavors of operators.
3321 ** static const class members
3323 Printing of static const class members that are initialized in the
3324 class definition has been fixed.
3326 * Windows Thread Information Block access.
3328 On Windows targets, GDB now supports displaying the Windows Thread
3329 Information Block (TIB) structure. This structure is visible either
3330 by using the new command `info w32 thread-information-block' or, by
3331 dereferencing the new convenience variable named `$_tlb', a
3332 thread-specific pointer to the TIB. This feature is also supported
3333 when remote debugging using GDBserver.
3335 * Static tracepoints
3337 Static tracepoints are calls in the user program into a tracing
3338 library. One such library is a port of the LTTng kernel tracer to
3339 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3340 When debugging with GDBserver, GDB now supports combining the GDB
3341 tracepoint machinery with such libraries. For example: the user can
3342 use GDB to probe a static tracepoint marker (a call from the user
3343 program into the tracing library) with the new "strace" command (see
3344 "New commands" below). This creates a "static tracepoint" in the
3345 breakpoint list, that can be manipulated with the same feature set
3346 as fast and regular tracepoints. E.g., collect registers, local and
3347 global variables, collect trace state variables, and define
3348 tracepoint conditions. In addition, the user can collect extra
3349 static tracepoint marker specific data, by collecting the new
3350 $_sdata internal variable. When analyzing the trace buffer, you can
3351 inspect $_sdata like any other variable available to GDB. For more
3352 information, see the "Tracepoints" chapter in GDB user manual. New
3353 remote packets have been defined to support static tracepoints, see
3354 the "New remote packets" section below.
3356 * Better reconstruction of tracepoints after disconnected tracing
3358 GDB will attempt to download the original source form of tracepoint
3359 definitions when starting a trace run, and then will upload these
3360 upon reconnection to the target, resulting in a more accurate
3361 reconstruction of the tracepoints that are in use on the target.
3365 You can now exercise direct control over the ways that GDB can
3366 affect your program. For instance, you can disallow the setting of
3367 breakpoints, so that the program can run continuously (assuming
3368 non-stop mode). In addition, the "observer" variable is available
3369 to switch all of the different controls; in observer mode, GDB
3370 cannot affect the target's behavior at all, which is useful for
3371 tasks like diagnosing live systems in the field.
3373 * The new convenience variable $_thread holds the number of the
3376 * New remote packets
3380 Return the address of the Windows Thread Information Block of a given thread.
3384 In response to several of the tracepoint packets, the target may now
3385 also respond with a number of intermediate `qRelocInsn' request
3386 packets before the final result packet, to have GDB handle
3387 relocating an instruction to execute at a different address. This
3388 is particularly useful for stubs that support fast tracepoints. GDB
3389 reports support for this feature in the qSupported packet.
3393 List static tracepoint markers in the target program.
3397 List static tracepoint markers at a given address in the target
3400 qXfer:statictrace:read
3402 Read the static trace data collected (by a `collect $_sdata'
3403 tracepoint action). The remote stub reports support for this packet
3404 to gdb's qSupported query.
3408 Send the current settings of GDB's permission flags.
3412 Send part of the source (textual) form of a tracepoint definition,
3413 which includes location, conditional, and action list.
3415 * The source command now accepts a -s option to force searching for the
3416 script in the source search path even if the script name specifies
3419 * New features in the GDB remote stub, GDBserver
3421 - GDBserver now support tracepoints (including fast tracepoints, and
3422 static tracepoints). The feature is currently supported by the
3423 i386-linux and amd64-linux builds. See the "Tracepoints support
3424 in gdbserver" section in the manual for more information.
3426 GDBserver JIT compiles the tracepoint's conditional agent
3427 expression bytecode into native code whenever possible for low
3428 overhead dynamic tracepoints conditionals. For such tracepoints,
3429 an expression that examines program state is evaluated when the
3430 tracepoint is reached, in order to determine whether to capture
3431 trace data. If the condition is simple and false, processing the
3432 tracepoint finishes very quickly and no data is gathered.
3434 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3435 for static tracepoints support.
3437 - GDBserver now supports x86_64 Windows 64-bit debugging.
3439 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3440 it understands register description.
3442 * The --batch flag now disables pagination and queries.
3444 * X86 general purpose registers
3446 GDB now supports reading/writing byte, word and double-word x86
3447 general purpose registers directly. This means you can use, say,
3448 $ah or $ax to refer, respectively, to the byte register AH and
3449 16-bit word register AX that are actually portions of the 32-bit
3450 register EAX or 64-bit register RAX.
3452 * The `commands' command now accepts a range of breakpoints to modify.
3453 A plain `commands' following a command that creates multiple
3454 breakpoints affects all the breakpoints set by that command. This
3455 applies to breakpoints set by `rbreak', and also applies when a
3456 single `break' command creates multiple breakpoints (e.g.,
3457 breakpoints on overloaded c++ functions).
3459 * The `rbreak' command now accepts a filename specification as part of
3460 its argument, limiting the functions selected by the regex to those
3461 in the specified file.
3463 * Support for remote debugging Windows and SymbianOS shared libraries
3464 from Unix hosts has been improved. Non Windows GDB builds now can
3465 understand target reported file names that follow MS-DOS based file
3466 system semantics, such as file names that include drive letters and
3467 use the backslash character as directory separator. This makes it
3468 possible to transparently use the "set sysroot" and "set
3469 solib-search-path" on Unix hosts to point as host copies of the
3470 target's shared libraries. See the new command "set
3471 target-file-system-kind" described below, and the "Commands to
3472 specify files" section in the user manual for more information.
3476 eval template, expressions...
3477 Convert the values of one or more expressions under the control
3478 of the string template to a command line, and call it.
3480 set target-file-system-kind unix|dos-based|auto
3481 show target-file-system-kind
3482 Set or show the assumed file system kind for target reported file
3485 save breakpoints <filename>
3486 Save all current breakpoint definitions to a file suitable for use
3487 in a later debugging session. To read the saved breakpoint
3488 definitions, use the `source' command.
3490 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3493 info static-tracepoint-markers
3494 Display information about static tracepoint markers in the target.
3496 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3497 Define a static tracepoint by probing a marker at the given
3498 function, line, address, or marker ID.
3502 Enable and disable observer mode.
3504 set may-write-registers on|off
3505 set may-write-memory on|off
3506 set may-insert-breakpoints on|off
3507 set may-insert-tracepoints on|off
3508 set may-insert-fast-tracepoints on|off
3509 set may-interrupt on|off
3510 Set individual permissions for GDB effects on the target. Note that
3511 some of these settings can have undesirable or surprising
3512 consequences, particularly when changed in the middle of a session.
3513 For instance, disabling the writing of memory can prevent
3514 breakpoints from being inserted, cause single-stepping to fail, or
3515 even crash your program, if you disable after breakpoints have been
3516 inserted. However, GDB should not crash.
3518 set record memory-query on|off
3519 show record memory-query
3520 Control whether to stop the inferior if memory changes caused
3521 by an instruction cannot be recorded.
3526 The disassemble command now supports "start,+length" form of two arguments.
3530 ** GDB now provides a new directory location, called the python directory,
3531 where Python scripts written for GDB can be installed. The location
3532 of that directory is <data-directory>/python, where <data-directory>
3533 is the GDB data directory. For more details, see section `Scripting
3534 GDB using Python' in the manual.
3536 ** The GDB Python API now has access to breakpoints, symbols, symbol
3537 tables, program spaces, inferiors, threads and frame's code blocks.
3538 Additionally, GDB Parameters can now be created from the API, and
3539 manipulated via set/show in the CLI.
3541 ** New functions gdb.target_charset, gdb.target_wide_charset,
3542 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3544 ** New exception gdb.GdbError.
3546 ** Pretty-printers are now also looked up in the current program space.
3548 ** Pretty-printers can now be individually enabled and disabled.
3550 ** GDB now looks for names of Python scripts to auto-load in a
3551 special section named `.debug_gdb_scripts', in addition to looking
3552 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3554 * Tracepoint actions were unified with breakpoint commands. In particular,
3555 there are no longer differences in "info break" output for breakpoints and
3556 tracepoints and the "commands" command can be used for both tracepoints and
3557 regular breakpoints.
3561 ARM Symbian arm*-*-symbianelf*
3563 * D language support.
3564 GDB now supports debugging programs written in the D programming
3567 * GDB now supports the extended ptrace interface for PowerPC which is
3568 available since Linux kernel version 2.6.34. This automatically enables
3569 any hardware breakpoints and additional hardware watchpoints available in
3570 the processor. The old ptrace interface exposes just one hardware
3571 watchpoint and no hardware breakpoints.
3573 * GDB is now able to use the Data Value Compare (DVC) register available on
3574 embedded PowerPC processors to implement in hardware simple watchpoint
3575 conditions of the form:
3577 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3579 This works in native GDB running on Linux kernels with the extended ptrace
3580 interface mentioned above.
3582 *** Changes in GDB 7.1
3586 ** Namespace Support
3588 GDB now supports importing of namespaces in C++. This enables the
3589 user to inspect variables from imported namespaces. Support for
3590 namepace aliasing has also been added. So, if a namespace is
3591 aliased in the current scope (e.g. namepace C=A; ) the user can
3592 print variables using the alias (e.g. (gdb) print C::x).
3596 All known bugs relating to the printing of virtual base class were
3597 fixed. It is now possible to call overloaded static methods using a
3602 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3603 and reinterpret_cast<> are now handled by the C++ expression parser.
3607 Xilinx MicroBlaze microblaze-*-*
3612 Xilinx MicroBlaze microblaze
3615 * Multi-program debugging.
3617 GDB now has support for multi-program (a.k.a. multi-executable or
3618 multi-exec) debugging. This allows for debugging multiple inferiors
3619 simultaneously each running a different program under the same GDB
3620 session. See "Debugging Multiple Inferiors and Programs" in the
3621 manual for more information. This implied some user visible changes
3622 in the multi-inferior support. For example, "info inferiors" now
3623 lists inferiors that are not running yet or that have exited
3624 already. See also "New commands" and "New options" below.
3626 * New tracing features
3628 GDB's tracepoint facility now includes several new features:
3630 ** Trace state variables
3632 GDB tracepoints now include support for trace state variables, which
3633 are variables managed by the target agent during a tracing
3634 experiment. They are useful for tracepoints that trigger each
3635 other, so for instance one tracepoint can count hits in a variable,
3636 and then a second tracepoint has a condition that is true when the
3637 count reaches a particular value. Trace state variables share the
3638 $-syntax of GDB convenience variables, and can appear in both
3639 tracepoint actions and condition expressions. Use the "tvariable"
3640 command to create, and "info tvariables" to view; see "Trace State
3641 Variables" in the manual for more detail.
3645 GDB now includes an option for defining fast tracepoints, which
3646 targets may implement more efficiently, such as by installing a jump
3647 into the target agent rather than a trap instruction. The resulting
3648 speedup can be by two orders of magnitude or more, although the
3649 tradeoff is that some program locations on some target architectures
3650 might not allow fast tracepoint installation, for instance if the
3651 instruction to be replaced is shorter than the jump. To request a
3652 fast tracepoint, use the "ftrace" command, with syntax identical to
3653 the regular trace command.
3655 ** Disconnected tracing
3657 It is now possible to detach GDB from the target while it is running
3658 a trace experiment, then reconnect later to see how the experiment
3659 is going. In addition, a new variable disconnected-tracing lets you
3660 tell the target agent whether to continue running a trace if the
3661 connection is lost unexpectedly.
3665 GDB now has the ability to save the trace buffer into a file, and
3666 then use that file as a target, similarly to you can do with
3667 corefiles. You can select trace frames, print data that was
3668 collected in them, and use tstatus to display the state of the
3669 tracing run at the moment that it was saved. To create a trace
3670 file, use "tsave <filename>", and to use it, do "target tfile
3673 ** Circular trace buffer
3675 You can ask the target agent to handle the trace buffer as a
3676 circular buffer, discarding the oldest trace frames to make room for
3677 newer ones, by setting circular-trace-buffer to on. This feature may
3678 not be available for all target agents.
3683 The disassemble command, when invoked with two arguments, now requires
3684 the arguments to be comma-separated.
3687 The info variables command now displays variable definitions. Files
3688 which only declare a variable are not shown.
3691 The source command is now capable of sourcing Python scripts.
3692 This feature is dependent on the debugger being build with Python
3695 Related to this enhancement is also the introduction of a new command
3696 "set script-extension" (see below).
3698 * New commands (for set/show, see "New options" below)
3700 record save [<FILENAME>]
3701 Save a file (in core file format) containing the process record
3702 execution log for replay debugging at a later time.
3704 record restore <FILENAME>
3705 Restore the process record execution log that was saved at an
3706 earlier time, for replay debugging.
3708 add-inferior [-copies <N>] [-exec <FILENAME>]
3711 clone-inferior [-copies <N>] [ID]
3712 Make a new inferior ready to execute the same program another
3713 inferior has loaded.
3718 maint info program-spaces
3719 List the program spaces loaded into GDB.
3721 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3722 show remote interrupt-sequence
3723 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3724 as the sequence to the remote target in order to interrupt the execution.
3725 Ctrl-C is a default. Some system prefers BREAK which is high level of
3726 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3727 Magic SysRq g. It is BREAK signal and character 'g'.
3729 set remote interrupt-on-connect [on | off]
3730 show remote interrupt-on-connect
3731 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3732 remote target when gdb connects to it. This is needed when you debug
3735 set remotebreak [on | off]
3737 Deprecated. Use "set/show remote interrupt-sequence" instead.
3739 tvariable $NAME [ = EXP ]
3740 Create or modify a trace state variable.
3743 List trace state variables and their values.
3745 delete tvariable $NAME ...
3746 Delete one or more trace state variables.
3749 Evaluate the given expressions without collecting anything into the
3750 trace buffer. (Valid in tracepoint actions only.)
3752 ftrace FN / FILE:LINE / *ADDR
3753 Define a fast tracepoint at the given function, line, or address.
3755 * New expression syntax
3757 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3758 GDB now parses 0b101010 identically with 42.
3762 set follow-exec-mode new|same
3763 show follow-exec-mode
3764 Control whether GDB reuses the same inferior across an exec call or
3765 creates a new one. This is useful to be able to restart the old
3766 executable after the inferior having done an exec call.
3768 set default-collect EXPR, ...
3769 show default-collect
3770 Define a list of expressions to be collected at each tracepoint.
3771 This is a useful way to ensure essential items are not overlooked,
3772 such as registers or a critical global variable.
3774 set disconnected-tracing
3775 show disconnected-tracing
3776 If set to 1, the target is instructed to continue tracing if it
3777 loses its connection to GDB. If 0, the target is to stop tracing
3780 set circular-trace-buffer
3781 show circular-trace-buffer
3782 If set to on, the target is instructed to use a circular trace buffer
3783 and discard the oldest trace frames instead of stopping the trace due
3784 to a full trace buffer. If set to off, the trace stops when the buffer
3785 fills up. Some targets may not support this.
3787 set script-extension off|soft|strict
3788 show script-extension
3789 If set to "off", the debugger does not perform any script language
3790 recognition, and all sourced files are assumed to be GDB scripts.
3791 If set to "soft" (the default), files are sourced according to
3792 filename extension, falling back to GDB scripts if the first
3794 If set to "strict", files are sourced according to filename extension.
3796 set ada trust-PAD-over-XVS on|off
3797 show ada trust-PAD-over-XVS
3798 If off, activate a workaround against a bug in the debugging information
3799 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3800 the GCC sources for more information about the GNAT encoding and
3801 PAD types in particular). It is always safe to set this option to
3802 off, but this introduces a slight performance penalty. The default
3805 * Python API Improvements
3807 ** GDB provides the new class gdb.LazyString. This is useful in
3808 some pretty-printing cases. The new method gdb.Value.lazy_string
3809 provides a simple way to create objects of this type.
3811 ** The fields returned by gdb.Type.fields now have an
3812 `is_base_class' attribute.
3814 ** The new method gdb.Type.range returns the range of an array type.
3816 ** The new method gdb.parse_and_eval can be used to parse and
3817 evaluate an expression.
3819 * New remote packets
3822 Define a trace state variable.
3825 Get the current value of a trace state variable.
3828 Set desired tracing behavior upon disconnection.
3831 Set the trace buffer to be linear or circular.
3834 Get data about the tracepoints currently in use.
3838 Process record now works correctly with hardware watchpoints.
3840 Multiple bug fixes have been made to the mips-irix port, making it
3841 much more reliable. In particular:
3842 - Debugging threaded applications is now possible again. Previously,
3843 GDB would hang while starting the program, or while waiting for
3844 the program to stop at a breakpoint.
3845 - Attaching to a running process no longer hangs.
3846 - An error occurring while loading a core file has been fixed.
3847 - Changing the value of the PC register now works again. This fixes
3848 problems observed when using the "jump" command, or when calling
3849 a function from GDB, or even when assigning a new value to $pc.
3850 - With the "finish" and "return" commands, the return value for functions
3851 returning a small array is now correctly printed.
3852 - It is now possible to break on shared library code which gets executed
3853 during a shared library init phase (code executed while executing
3854 their .init section). Previously, the breakpoint would have no effect.
3855 - GDB is now able to backtrace through the signal handler for
3856 non-threaded programs.
3858 PIE (Position Independent Executable) programs debugging is now supported.
3859 This includes debugging execution of PIC (Position Independent Code) shared
3860 libraries although for that, it should be possible to run such libraries as an
3863 *** Changes in GDB 7.0
3865 * GDB now has an interface for JIT compilation. Applications that
3866 dynamically generate code can create symbol files in memory and register
3867 them with GDB. For users, the feature should work transparently, and
3868 for JIT developers, the interface is documented in the GDB manual in the
3869 "JIT Compilation Interface" chapter.
3871 * Tracepoints may now be conditional. The syntax is as for
3872 breakpoints; either an "if" clause appended to the "trace" command,
3873 or the "condition" command is available. GDB sends the condition to
3874 the target for evaluation using the same bytecode format as is used
3875 for tracepoint actions.
3877 * The disassemble command now supports: an optional /r modifier, print the
3878 raw instructions in hex as well as in symbolic form, and an optional /m
3879 modifier to print mixed source+assembly.
3881 * Process record and replay
3883 In a architecture environment that supports ``process record and
3884 replay'', ``process record and replay'' target can record a log of
3885 the process execution, and replay it with both forward and reverse
3888 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3889 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3890 set execution-direction {forward|reverse}, for targets that support
3893 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3894 feature is available with a native GDB running on kernel version
3897 * GDB now has support for multi-byte and wide character sets on the
3898 target. Strings whose character type is wchar_t, char16_t, or
3899 char32_t are now correctly printed. GDB supports wide- and unicode-
3900 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3901 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3902 `printf'. This feature requires iconv to work properly; if your
3903 system does not have a working iconv, GDB can use GNU libiconv. See
3904 the installation instructions for more information.
3906 * GDB now supports automatic retrieval of shared library files from
3907 remote targets. To use this feature, specify a system root that begins
3908 with the `remote:' prefix, either via the `set sysroot' command or via
3909 the `--with-sysroot' configure-time option.
3911 * "info sharedlibrary" now takes an optional regex of libraries to show,
3912 and it now reports if a shared library has no debugging information.
3914 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3915 now complete on file names.
3917 * When completing in expressions, gdb will attempt to limit
3918 completions to allowable structure or union fields, where appropriate.
3919 For instance, consider:
3921 # struct example { int f1; double f2; };
3922 # struct example variable;
3925 If the user types TAB at the end of this command line, the available
3926 completions will be "f1" and "f2".
3928 * Inlined functions are now supported. They show up in backtraces, and
3929 the "step", "next", and "finish" commands handle them automatically.
3931 * GDB now supports the token-splicing (##) and stringification (#)
3932 operators when expanding macros. It also supports variable-arity
3935 * GDB now supports inspecting extra signal information, exported by
3936 the new $_siginfo convenience variable. The feature is currently
3937 implemented on linux ARM, i386 and amd64.
3939 * GDB can now display the VFP floating point registers and NEON vector
3940 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3941 can provide these registers (requires Linux 2.6.30 or later). Remote
3942 and simulator targets may also provide them.
3944 * New remote packets
3947 Search memory for a sequence of bytes.
3950 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3951 operation over reliable transport links. Use of this packet is
3952 controlled by the `set remote noack-packet' command.
3955 Kill the process with the specified process ID. Use this in preference
3956 to `k' when multiprocess protocol extensions are supported.
3959 Obtains additional operating system information
3963 Read or write additional signal information.
3965 * Removed remote protocol undocumented extension
3967 An undocumented extension to the remote protocol's `S' stop reply
3968 packet that permited the stub to pass a process id was removed.
3969 Remote servers should use the `T' stop reply packet instead.
3971 * GDB now supports multiple function calling conventions according to the
3972 DWARF-2 DW_AT_calling_convention function attribute.
3974 * The SH target utilizes the aforementioned change to distinguish between gcc
3975 and Renesas calling convention. It also adds the new CLI commands
3976 `set/show sh calling-convention'.
3978 * GDB can now read compressed debug sections, as produced by GNU gold
3979 with the --compress-debug-sections=zlib flag.
3981 * 64-bit core files are now supported on AIX.
3983 * Thread switching is now supported on Tru64.
3985 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3986 which will be allocated using malloc later in program execution.
3988 * The qXfer:libraries:read remote procotol packet now allows passing a
3989 list of section offsets.
3991 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3992 conditions handling signals delivered during attach or thread creation
3993 have also been fixed.
3995 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3996 From the user's standpoint, all unqualified instances of True and False
3997 are treated as the standard definitions, regardless of context.
3999 * GDB now parses C++ symbol and type names more flexibly. For
4002 template<typename T> class C { };
4005 GDB will now correctly handle all of:
4007 ptype C<char const *>
4008 ptype C<char const*>
4009 ptype C<const char *>
4010 ptype C<const char*>
4012 * New features in the GDB remote stub, gdbserver
4014 - The "--wrapper" command-line argument tells gdbserver to use a
4015 wrapper program to launch programs for debugging.
4017 - On PowerPC and S/390 targets, it is now possible to use a single
4018 gdbserver executable to debug both 32-bit and 64-bit programs.
4019 (This requires gdbserver itself to be built as a 64-bit executable.)
4021 - gdbserver uses the new noack protocol mode for TCP connections to
4022 reduce communications latency, if also supported and enabled in GDB.
4024 - Support for the sparc64-linux-gnu target is now included in
4027 - The amd64-linux build of gdbserver now supports debugging both
4028 32-bit and 64-bit programs.
4030 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4031 now support hardware watchpoints, and will use them automatically
4036 GDB now has support for scripting using Python. Whether this is
4037 available is determined at configure time.
4039 New GDB commands can now be written in Python.
4041 * Ada tasking support
4043 Ada tasks can now be inspected in GDB. The following commands have
4047 Print the list of Ada tasks.
4049 Print detailed information about task number N.
4051 Print the task number of the current task.
4053 Switch the context of debugging to task number N.
4055 * Support for user-defined prefixed commands. The "define" command can
4056 add new commands to existing prefixes, e.g. "target".
4058 * Multi-inferior, multi-process debugging.
4060 GDB now has generalized support for multi-inferior debugging. See
4061 "Debugging Multiple Inferiors" in the manual for more information.
4062 Although availability still depends on target support, the command
4063 set is more uniform now. The GNU/Linux specific multi-forks support
4064 has been migrated to this new framework. This implied some user
4065 visible changes; see "New commands" and also "Removed commands"
4068 * Target descriptions can now describe the target OS ABI. See the
4069 "Target Description Format" section in the user manual for more
4072 * Target descriptions can now describe "compatible" architectures
4073 to indicate that the target can execute applications for a different
4074 architecture in addition to those for the main target architecture.
4075 See the "Target Description Format" section in the user manual for
4078 * Multi-architecture debugging.
4080 GDB now includes general supports for debugging applications on
4081 hybrid systems that use more than one single processor architecture
4082 at the same time. Each such hybrid architecture still requires
4083 specific support to be added. The only hybrid architecture supported
4084 in this version of GDB is the Cell Broadband Engine.
4086 * GDB now supports integrated debugging of Cell/B.E. applications that
4087 use both the PPU and SPU architectures. To enable support for hybrid
4088 Cell/B.E. debugging, you need to configure GDB to support both the
4089 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4090 --enable-targets configure option.
4092 * Non-stop mode debugging.
4094 For some targets, GDB now supports an optional mode of operation in
4095 which you can examine stopped threads while other threads continue
4096 to execute freely. This is referred to as non-stop mode, with the
4097 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4098 section in the user manual for more information.
4100 To be able to support remote non-stop debugging, a remote stub needs
4101 to implement the non-stop mode remote protocol extensions, as
4102 described in the "Remote Non-Stop" section of the user manual. The
4103 GDB remote stub, gdbserver, has been adjusted to support these
4104 extensions on linux targets.
4106 * New commands (for set/show, see "New options" below)
4108 catch syscall [NAME(S) | NUMBER(S)]
4109 Catch system calls. Arguments, which should be names of system
4110 calls or their numbers, mean catch only those syscalls. Without
4111 arguments, every syscall will be caught. When the inferior issues
4112 any of the specified syscalls, GDB will stop and announce the system
4113 call, both when it is called and when its call returns. This
4114 feature is currently available with a native GDB running on the
4115 Linux Kernel, under the following architectures: x86, x86_64,
4116 PowerPC and PowerPC64.
4118 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4120 Search memory for a sequence of bytes.
4122 maint set python print-stack
4123 maint show python print-stack
4124 Show a stack trace when an error is encountered in a Python script.
4127 Invoke CODE by passing it to the Python interpreter.
4132 These allow macros to be defined, undefined, and listed
4136 Show operating system information about processes.
4139 List the inferiors currently under GDB's control.
4142 Switch focus to inferior number NUM.
4145 Detach from inferior number NUM.
4148 Kill inferior number NUM.
4152 set spu stop-on-load
4153 show spu stop-on-load
4154 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4156 set spu auto-flush-cache
4157 show spu auto-flush-cache
4158 Control whether to automatically flush the software-managed cache
4159 during Cell/B.E. debugging.
4161 set sh calling-convention
4162 show sh calling-convention
4163 Control the calling convention used when calling SH target functions.
4166 show debug timestamp
4167 Control display of timestamps with GDB debugging output.
4169 set disassemble-next-line
4170 show disassemble-next-line
4171 Control display of disassembled source lines or instructions when
4174 set remote noack-packet
4175 show remote noack-packet
4176 Set/show the use of remote protocol QStartNoAckMode packet. See above
4177 under "New remote packets."
4179 set remote query-attached-packet
4180 show remote query-attached-packet
4181 Control use of remote protocol `qAttached' (query-attached) packet.
4183 set remote read-siginfo-object
4184 show remote read-siginfo-object
4185 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4188 set remote write-siginfo-object
4189 show remote write-siginfo-object
4190 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4193 set remote reverse-continue
4194 show remote reverse-continue
4195 Control use of remote protocol 'bc' (reverse-continue) packet.
4197 set remote reverse-step
4198 show remote reverse-step
4199 Control use of remote protocol 'bs' (reverse-step) packet.
4201 set displaced-stepping
4202 show displaced-stepping
4203 Control displaced stepping mode. Displaced stepping is a way to
4204 single-step over breakpoints without removing them from the debuggee.
4205 Also known as "out-of-line single-stepping".
4208 show debug displaced
4209 Control display of debugging info for displaced stepping.
4211 maint set internal-error
4212 maint show internal-error
4213 Control what GDB does when an internal error is detected.
4215 maint set internal-warning
4216 maint show internal-warning
4217 Control what GDB does when an internal warning is detected.
4222 Use a wrapper program to launch programs for debugging.
4224 set multiple-symbols (all|ask|cancel)
4225 show multiple-symbols
4226 The value of this variable can be changed to adjust the debugger behavior
4227 when an expression or a breakpoint location contains an ambiguous symbol
4228 name (an overloaded function name, for instance).
4230 set breakpoint always-inserted
4231 show breakpoint always-inserted
4232 Keep breakpoints always inserted in the target, as opposed to inserting
4233 them when resuming the target, and removing them when the target stops.
4234 This option can improve debugger performance on slow remote targets.
4236 set arm fallback-mode (arm|thumb|auto)
4237 show arm fallback-mode
4238 set arm force-mode (arm|thumb|auto)
4240 These commands control how ARM GDB determines whether instructions
4241 are ARM or Thumb. The default for both settings is auto, which uses
4242 the current CPSR value for instructions without symbols; previous
4243 versions of GDB behaved as if "set arm fallback-mode arm".
4245 set disable-randomization
4246 show disable-randomization
4247 Standalone programs run with the virtual address space randomization enabled
4248 by default on some platforms. This option keeps the addresses stable across
4249 multiple debugging sessions.
4253 Control whether other threads are stopped or not when some thread hits
4258 Requests that asynchronous execution is enabled in the target, if available.
4259 In this case, it's possible to resume target in the background, and interact
4260 with GDB while the target is running. "show target-async" displays the
4261 current state of asynchronous execution of the target.
4263 set target-wide-charset
4264 show target-wide-charset
4265 The target-wide-charset is the name of the character set that GDB
4266 uses when printing characters whose type is wchar_t.
4268 set tcp auto-retry (on|off)
4270 set tcp connect-timeout
4271 show tcp connect-timeout
4272 These commands allow GDB to retry failed TCP connections to a remote stub
4273 with a specified timeout period; this is useful if the stub is launched
4274 in parallel with GDB but may not be ready to accept connections immediately.
4276 set libthread-db-search-path
4277 show libthread-db-search-path
4278 Control list of directories which GDB will search for appropriate
4281 set schedule-multiple (on|off)
4282 show schedule-multiple
4283 Allow GDB to resume all threads of all processes or only threads of
4284 the current process.
4288 Use more aggressive caching for accesses to the stack. This improves
4289 performance of remote debugging (particularly backtraces) without
4290 affecting correctness.
4292 set interactive-mode (on|off|auto)
4293 show interactive-mode
4294 Control whether GDB runs in interactive mode (on) or not (off).
4295 When in interactive mode, GDB waits for the user to answer all
4296 queries. Otherwise, GDB does not wait and assumes the default
4297 answer. When set to auto (the default), GDB determines which
4298 mode to use based on the stdin settings.
4303 For program forks, this is replaced by the new more generic `info
4304 inferiors' command. To list checkpoints, you can still use the
4305 `info checkpoints' command, which was an alias for the `info forks'
4309 Replaced by the new `inferior' command. To switch between
4310 checkpoints, you can still use the `restart' command, which was an
4311 alias for the `fork' command.
4314 This is removed, since some targets don't have a notion of
4315 processes. To switch between processes, you can still use the
4316 `inferior' command using GDB's own inferior number.
4319 For program forks, this is replaced by the new more generic `kill
4320 inferior' command. To delete a checkpoint, you can still use the
4321 `delete checkpoint' command, which was an alias for the `delete
4325 For program forks, this is replaced by the new more generic `detach
4326 inferior' command. To detach a checkpoint, you can still use the
4327 `detach checkpoint' command, which was an alias for the `detach
4330 * New native configurations
4332 x86/x86_64 Darwin i[34567]86-*-darwin*
4334 x86_64 MinGW x86_64-*-mingw*
4338 Lattice Mico32 lm32-*
4339 x86 DICOS i[34567]86-*-dicos*
4340 x86_64 DICOS x86_64-*-dicos*
4343 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4344 (mingw32ce) debugging.
4350 These commands were actually not implemented on any target.
4352 *** Changes in GDB 6.8
4354 * New native configurations
4356 NetBSD/hppa hppa*-*netbsd*
4357 Xtensa GNU/Linux xtensa*-*-linux*
4361 NetBSD/hppa hppa*-*-netbsd*
4362 Xtensa GNU/Lunux xtensa*-*-linux*
4364 * Change in command line behavior -- corefiles vs. process ids.
4366 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4367 attaching to process NUMBER fails, GDB no longer attempts to open a
4368 core file named NUMBER. Attaching to a program using the -c option
4369 is no longer supported. Instead, use the '-p' or '--pid' options.
4371 * GDB can now be built as a native debugger for debugging Windows x86
4372 (mingw32) Portable Executable (PE) programs.
4374 * Pending breakpoints no longer change their number when their address
4377 * GDB now supports breakpoints with multiple locations,
4378 including breakpoints on C++ constructors, inside C++ templates,
4379 and in inlined functions.
4381 * GDB's ability to debug optimized code has been improved. GDB more
4382 accurately identifies function bodies and lexical blocks that occupy
4383 more than one contiguous range of addresses.
4385 * Target descriptions can now describe registers for PowerPC.
4387 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4388 registers on PowerPC targets.
4390 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4391 targets even when the libthread_db library is not available.
4393 * The GDB remote stub, gdbserver, now supports the new file transfer
4394 commands (remote put, remote get, and remote delete).
4396 * The GDB remote stub, gdbserver, now supports run and attach in
4397 extended-remote mode.
4399 * hppa*64*-*-hpux11* target broken
4400 The debugger is unable to start a program and fails with the following
4401 error: "Error trying to get information about dynamic linker".
4402 The gdb-6.7 release is also affected.
4404 * GDB now supports the --enable-targets= configure option to allow
4405 building a single GDB executable that supports multiple remote
4406 target architectures.
4408 * GDB now supports debugging C and C++ programs which use the
4409 Decimal Floating Point extension. In addition, the PowerPC target
4410 now has a set of pseudo-registers to inspect decimal float values
4411 stored in two consecutive float registers.
4413 * The -break-insert MI command can optionally create pending
4416 * Improved support for debugging Ada
4417 Many improvements to the Ada language support have been made. These
4419 - Better support for Ada2005 interface types
4420 - Improved handling of arrays and slices in general
4421 - Better support for Taft-amendment types
4422 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4424 - Improved command completion in Ada
4427 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4432 set print frame-arguments (all|scalars|none)
4433 show print frame-arguments
4434 The value of this variable can be changed to control which argument
4435 values should be printed by the debugger when displaying a frame.
4440 Transfer files to and from a remote target, and delete remote files.
4447 Transfer files to and from a remote target, and delete remote files.
4449 * New remote packets
4456 Open, close, read, write, and delete files on the remote system.
4459 Attach to an existing process on the remote system, in extended-remote
4463 Run a new process on the remote system, in extended-remote mode.
4465 *** Changes in GDB 6.7
4467 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4468 bfd, libiberty and opcodes, as revealed by static analysis donated by
4469 Coverity, Inc. (http://scan.coverity.com).
4471 * When looking up multiply-defined global symbols, GDB will now prefer the
4472 symbol definition in the current shared library if it was built using the
4473 -Bsymbolic linker option.
4475 * When the Text User Interface (TUI) is not configured, GDB will now
4476 recognize the -tui command-line option and print a message that the TUI
4479 * The GDB remote stub, gdbserver, now has lower overhead for high
4480 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4482 * GDB for MIPS targets now autodetects whether a remote target provides
4483 32-bit or 64-bit register values.
4485 * Support for C++ member pointers has been improved.
4487 * GDB now understands XML target descriptions, which specify the
4488 target's overall architecture. GDB can read a description from
4489 a local file or over the remote serial protocol.
4491 * Vectors of single-byte data use a new integer type which is not
4492 automatically displayed as character or string data.
4494 * The /s format now works with the print command. It displays
4495 arrays of single-byte integers and pointers to single-byte integers
4498 * Target descriptions can now describe target-specific registers,
4499 for architectures which have implemented the support (currently
4500 only ARM, M68K, and MIPS).
4502 * GDB and the GDB remote stub, gdbserver, now support the XScale
4505 * The GDB remote stub, gdbserver, has been updated to support
4506 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4507 has been rewritten to use the standard GDB remote protocol.
4509 * GDB can now step into C++ functions which are called through thunks.
4511 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4513 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4514 layout. It also supports a TextSeg= and DataSeg= response when only
4515 segment base addresses (rather than offsets) are available.
4517 * The /i format now outputs any trailing branch delay slot instructions
4518 immediately following the last instruction within the count specified.
4520 * The GDB remote protocol "T" stop reply packet now supports a
4521 "library" response. Combined with the new "qXfer:libraries:read"
4522 packet, this response allows GDB to debug shared libraries on targets
4523 where the operating system manages the list of loaded libraries (e.g.
4524 Windows and SymbianOS).
4526 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4527 (DLLs) on Windows and Windows CE targets.
4529 * GDB now supports a faster verification that a .debug file matches its binary
4530 according to its build-id signature, if the signature is present.
4536 Enable or disable hardware flow control (RTS/CTS) on the serial port
4537 when debugging using remote targets.
4539 set mem inaccessible-by-default
4540 show mem inaccessible-by-default
4541 If the target supplies a memory map, for instance via the remote
4542 protocol's "qXfer:memory-map:read" packet, setting this variable
4543 prevents GDB from accessing memory outside the memory map. This
4544 is useful for targets with memory mapped registers or which react
4545 badly to accesses of unmapped address space.
4547 set breakpoint auto-hw
4548 show breakpoint auto-hw
4549 If the target supplies a memory map, for instance via the remote
4550 protocol's "qXfer:memory-map:read" packet, setting this variable
4551 lets GDB use hardware breakpoints automatically for memory regions
4552 where it can not use software breakpoints. This covers both the
4553 "break" command and internal breakpoints used for other commands
4554 including "next" and "finish".
4557 catch exception unhandled
4558 Stop the program execution when Ada exceptions are raised.
4561 Stop the program execution when an Ada assertion failed.
4565 Set an alternate system root for target files. This is a more
4566 general version of "set solib-absolute-prefix", which is now
4567 an alias to "set sysroot".
4570 Provide extended SPU facility status information. This set of
4571 commands is available only when debugging the Cell/B.E. SPU
4574 * New native configurations
4576 OpenBSD/sh sh*-*openbsd*
4579 unset tdesc filename
4581 Use the specified local file as an XML target description, and do
4582 not query the target for its built-in description.
4586 OpenBSD/sh sh*-*-openbsd*
4587 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4588 Toshiba Media Processor mep-elf
4590 * New remote packets
4593 Ignore the specified signals; pass them directly to the debugged program
4594 without stopping other threads or reporting them to GDB.
4596 qXfer:features:read:
4597 Read an XML target description from the target, which describes its
4602 Read or write contents of an spufs file on the target system. These
4603 packets are available only on the Cell/B.E. SPU architecture.
4605 qXfer:libraries:read:
4606 Report the loaded shared libraries. Combined with new "T" packet
4607 response, this packet allows GDB to debug shared libraries on
4608 targets where the operating system manages the list of loaded
4609 libraries (e.g. Windows and SymbianOS).
4613 Support for these obsolete configurations has been removed.
4621 i[34567]86-*-lynxos*
4622 i[34567]86-*-netware*
4623 i[34567]86-*-sco3.2v5*
4624 i[34567]86-*-sco3.2v4*
4626 i[34567]86-*-sysv4.2*
4629 i[34567]86-*-unixware2*
4630 i[34567]86-*-unixware*
4639 * Other removed features
4646 Various m68k-only ROM monitors.
4653 Various Renesas ROM monitors and debugging interfaces for SH and
4658 Support for a Macraigor serial interface to on-chip debugging.
4659 GDB does not directly support the newer parallel or USB
4664 A debug information format. The predecessor to DWARF 2 and
4665 DWARF 3, which are still supported.
4667 Support for the HP aCC compiler on HP-UX/PA-RISC
4669 SOM-encapsulated symbolic debugging information, automatic
4670 invocation of pxdb, and the aCC custom C++ ABI. This does not
4671 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4672 with aCC can still be debugged on an assembly level.
4674 MIPS ".pdr" sections
4676 A MIPS-specific format used to describe stack frame layout
4677 in debugging information.
4681 GDB could work with an older version of Guile to debug
4682 the interpreter and Scheme programs running in it.
4684 set mips stack-arg-size
4685 set mips saved-gpreg-size
4687 Use "set mips abi" to control parameter passing for MIPS.
4689 *** Changes in GDB 6.6
4694 Cell Broadband Engine SPU spu-elf
4696 * GDB can now be configured as a cross-debugger targeting native Windows
4697 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4698 running on a Windows system over TCP/IP to debug Windows programs.
4700 * The GDB remote stub, gdbserver, has been updated to support Windows and
4701 Cygwin debugging. Both single-threaded and multi-threaded programs are
4704 * The "set trust-readonly-sections" command works again. This command was
4705 broken in GDB 6.3, 6.4, and 6.5.
4707 * The "load" command now supports writing to flash memory, if the remote
4708 stub provides the required support.
4710 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4711 longer requires symbolic debug information (e.g. DWARF-2).
4716 unset substitute-path
4717 show substitute-path
4718 Manage a list of substitution rules that GDB uses to rewrite the name
4719 of the directories where the sources are located. This can be useful
4720 for instance when the sources were moved to a different location
4721 between compilation and debugging.
4725 Print each CLI command as it is executed. Each command is prefixed with
4726 a number of `+' symbols representing the nesting depth.
4727 The source command now has a `-v' option to enable the same feature.
4731 The ARM Demon monitor support (RDP protocol, "target rdp").
4733 Kernel Object Display, an embedded debugging feature which only worked with
4734 an obsolete version of Cisco IOS.
4736 The 'set download-write-size' and 'show download-write-size' commands.
4738 * New remote packets
4741 Tell a stub about GDB client features, and request remote target features.
4742 The first feature implemented is PacketSize, which allows the target to
4743 specify the size of packets it can handle - to minimize the number of
4744 packets required and improve performance when connected to a remote
4748 Fetch an OS auxilliary vector from the remote stub. This packet is a
4749 more efficient replacement for qPart:auxv:read.
4751 qXfer:memory-map:read:
4752 Fetch a memory map from the remote stub, including information about
4753 RAM, ROM, and flash memory devices.
4758 Erase and program a flash memory device.
4760 * Removed remote packets
4763 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4764 used it, and only gdbserver implemented it.
4766 *** Changes in GDB 6.5
4770 Renesas M32C/M16C m32c-elf
4772 Morpho Technologies ms1 ms1-elf
4776 init-if-undefined Initialize a convenience variable, but
4777 only if it doesn't already have a value.
4779 The following commands are presently only implemented for native GNU/Linux:
4781 checkpoint Save a snapshot of the program state.
4783 restart <n> Return the program state to a
4784 previously saved state.
4786 info checkpoints List currently saved checkpoints.
4788 delete-checkpoint <n> Delete a previously saved checkpoint.
4790 set|show detach-on-fork Tell gdb whether to detach from a newly
4791 forked process, or to keep debugging it.
4793 info forks List forks of the user program that
4794 are available to be debugged.
4796 fork <n> Switch to debugging one of several
4797 forks of the user program that are
4798 available to be debugged.
4800 delete-fork <n> Delete a fork from the list of forks
4801 that are available to be debugged (and
4802 kill the forked process).
4804 detach-fork <n> Delete a fork from the list of forks
4805 that are available to be debugged (and
4806 allow the process to continue).
4810 Morpho Technologies ms2 ms1-elf
4812 * Improved Windows host support
4814 GDB now builds as a cross debugger hosted on i686-mingw32, including
4815 native console support, and remote communications using either
4816 network sockets or serial ports.
4818 * Improved Modula-2 language support
4820 GDB can now print most types in the Modula-2 syntax. This includes:
4821 basic types, set types, record types, enumerated types, range types,
4822 pointer types and ARRAY types. Procedure var parameters are correctly
4823 printed and hexadecimal addresses and character constants are also
4824 written in the Modula-2 syntax. Best results can be obtained by using
4825 GNU Modula-2 together with the -gdwarf-2 command line option.
4829 The ARM rdi-share module.
4831 The Netware NLM debug server.
4833 *** Changes in GDB 6.4
4835 * New native configurations
4837 OpenBSD/arm arm*-*-openbsd*
4838 OpenBSD/mips64 mips64-*-openbsd*
4842 Morpho Technologies ms1 ms1-elf
4844 * New command line options
4846 --batch-silent As for --batch, but totally silent.
4847 --return-child-result The debugger will exist with the same value
4848 the child (debugged) program exited with.
4849 --eval-command COMMAND, -ex COMMAND
4850 Execute a single GDB CLI command. This may be
4851 specified multiple times and in conjunction
4852 with the --command (-x) option.
4854 * Deprecated commands removed
4856 The following commands, that were deprecated in 2000, have been
4860 set|show arm disassembly-flavor set|show arm disassembler
4861 othernames set arm disassembler
4862 set|show remotedebug set|show debug remote
4863 set|show archdebug set|show debug arch
4864 set|show eventdebug set|show debug event
4867 * New BSD user-level threads support
4869 It is now possible to debug programs using the user-level threads
4870 library on OpenBSD and FreeBSD. Currently supported (target)
4873 FreeBSD/amd64 x86_64-*-freebsd*
4874 FreeBSD/i386 i386-*-freebsd*
4875 OpenBSD/i386 i386-*-openbsd*
4877 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4878 are not yet supported.
4880 * New support for Matsushita MN10300 w/sim added
4881 (Work in progress). mn10300-elf.
4883 * REMOVED configurations and files
4885 VxWorks and the XDR protocol *-*-vxworks
4886 Motorola MCORE mcore-*-*
4887 National Semiconductor NS32000 ns32k-*-*
4889 * New "set print array-indexes" command
4891 After turning this setting "on", GDB prints the index of each element
4892 when displaying arrays. The default is "off" to preserve the previous
4895 * VAX floating point support
4897 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4899 * User-defined command support
4901 In addition to using $arg0..$arg9 for argument passing, it is now possible
4902 to use $argc to determine now many arguments have been passed. See the
4903 section on user-defined commands in the user manual for more information.
4905 *** Changes in GDB 6.3:
4907 * New command line option
4909 GDB now accepts -l followed by a number to set the timeout for remote
4912 * GDB works with GCC -feliminate-dwarf2-dups
4914 GDB now supports a more compact representation of DWARF-2 debug
4915 information using DW_FORM_ref_addr references. These are produced
4916 by GCC with the option -feliminate-dwarf2-dups and also by some
4917 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4918 to use -feliminate-dwarf2-dups.
4920 * Internationalization
4922 When supported by the host system, GDB will be built with
4923 internationalization (libintl). The task of marking up the sources is
4924 continued, we're looking forward to our first translation.
4928 Initial support for debugging programs compiled with the GNAT
4929 implementation of the Ada programming language has been integrated
4930 into GDB. In this release, support is limited to expression evaluation.
4932 * New native configurations
4934 GNU/Linux/m32r m32r-*-linux-gnu
4938 GDB's remote protocol now includes support for the 'p' packet. This
4939 packet is used to fetch individual registers from a remote inferior.
4941 * END-OF-LIFE registers[] compatibility module
4943 GDB's internal register infrastructure has been completely rewritten.
4944 The new infrastructure making possible the implementation of key new
4945 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4948 GDB 6.3 will be the last release to include the the registers[]
4949 compatibility module that allowed out-of-date configurations to
4950 continue to work. This change directly impacts the following
4960 powerpc bdm protocol
4962 Unless there is activity to revive these configurations, they will be
4963 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4965 * OBSOLETE configurations and files
4967 Configurations that have been declared obsolete in this release have
4968 been commented out. Unless there is activity to revive these
4969 configurations, the next release of GDB will have their sources
4970 permanently REMOVED.
4979 *** Changes in GDB 6.2.1:
4981 * MIPS `break main; run' gave an heuristic-fence-post warning
4983 When attempting to run even a simple program, a warning about
4984 heuristic-fence-post being hit would be reported. This problem has
4987 * MIPS IRIX 'long double' crashed GDB
4989 When examining a long double variable, GDB would get a segmentation
4990 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4991 IRIX long double values).
4995 A bug in the VAX stack code was causing problems with the "next"
4996 command. This problem has been fixed.
4998 *** Changes in GDB 6.2:
5000 * Fix for ``many threads''
5002 On GNU/Linux systems that use the NPTL threads library, a program
5003 rapidly creating and deleting threads would confuse GDB leading to the
5006 ptrace: No such process.
5007 thread_db_get_info: cannot get thread info: generic error
5009 This problem has been fixed.
5011 * "-async" and "-noasync" options removed.
5013 Support for the broken "-noasync" option has been removed (it caused
5016 * New ``start'' command.
5018 This command runs the program until the begining of the main procedure.
5020 * New BSD Kernel Data Access Library (libkvm) interface
5022 Using ``target kvm'' it is now possible to debug kernel core dumps and
5023 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5024 platforms. Currently supported (native-only) configurations are:
5026 FreeBSD/amd64 x86_64-*-freebsd*
5027 FreeBSD/i386 i?86-*-freebsd*
5028 NetBSD/i386 i?86-*-netbsd*
5029 NetBSD/m68k m68*-*-netbsd*
5030 NetBSD/sparc sparc-*-netbsd*
5031 OpenBSD/amd64 x86_64-*-openbsd*
5032 OpenBSD/i386 i?86-*-openbsd*
5033 OpenBSD/m68k m68*-openbsd*
5034 OpenBSD/sparc sparc-*-openbsd*
5036 * Signal trampoline code overhauled
5038 Many generic problems with GDB's signal handling code have been fixed.
5039 These include: backtraces through non-contiguous stacks; recognition
5040 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5041 call; backtrace through a signal trampoline; step into and out of
5042 signal handlers; and single-stepping in the signal trampoline.
5044 Please note that kernel bugs are a limiting factor here. These
5045 features have been shown to work on an s390 GNU/Linux system that
5046 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5048 * Cygwin support for DWARF 2 added.
5050 * New native configurations
5052 GNU/Linux/hppa hppa*-*-linux*
5053 OpenBSD/hppa hppa*-*-openbsd*
5054 OpenBSD/m68k m68*-*-openbsd*
5055 OpenBSD/m88k m88*-*-openbsd*
5056 OpenBSD/powerpc powerpc-*-openbsd*
5057 NetBSD/vax vax-*-netbsd*
5058 OpenBSD/vax vax-*-openbsd*
5060 * END-OF-LIFE frame compatibility module
5062 GDB's internal frame infrastructure has been completely rewritten.
5063 The new infrastructure making it possible to support key new features
5064 including DWARF 2 Call Frame Information. To aid in the task of
5065 migrating old configurations to this new infrastructure, a
5066 compatibility module, that allowed old configurations to continue to
5067 work, was also included.
5069 GDB 6.2 will be the last release to include this frame compatibility
5070 module. This change directly impacts the following configurations:
5080 Unless there is activity to revive these configurations, they will be
5081 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5083 * REMOVED configurations and files
5085 Sun 3, running SunOS 3 m68*-*-sunos3*
5086 Sun 3, running SunOS 4 m68*-*-sunos4*
5087 Sun 2, running SunOS 3 m68000-*-sunos3*
5088 Sun 2, running SunOS 4 m68000-*-sunos4*
5089 Motorola 680x0 running LynxOS m68*-*-lynxos*
5090 AT&T 3b1/Unix pc m68*-att-*
5091 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5092 decstation mips-dec-* mips-little-*
5093 riscos mips-*-riscos* mips-*-sysv*
5094 sonymips mips-sony-*
5095 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5097 *** Changes in GDB 6.1.1:
5099 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5101 The TUI (Text-mode User Interface) is now built as part of a default
5102 GDB configuration. It is enabled by either selecting the TUI with the
5103 command line option "-i=tui" or by running the separate "gdbtui"
5104 program. For more information on the TUI, see the manual "Debugging
5107 * Pending breakpoint support (also included in GDB 6.1)
5109 Support has been added to allow you to specify breakpoints in shared
5110 libraries that have not yet been loaded. If a breakpoint location
5111 cannot be found, and the "breakpoint pending" option is set to auto,
5112 GDB queries you if you wish to make the breakpoint pending on a future
5113 shared-library load. If and when GDB resolves the breakpoint symbol,
5114 the pending breakpoint is removed as one or more regular breakpoints
5117 Pending breakpoints are very useful for GCJ Java debugging.
5119 * Fixed ISO-C build problems
5121 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5122 non ISO-C code that stopped them being built using a more strict ISO-C
5123 compiler (e.g., IBM's C compiler).
5125 * Fixed build problem on IRIX 5
5127 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5128 wasn't able to compile compile on an IRIX 5 system.
5130 * Added execute permission to gdb/gdbserver/configure
5132 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5133 permission. This bug would cause configure to fail on a number of
5134 systems (Solaris, IRIX). Ref: server/519.
5136 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5138 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5139 has been updated to use constant array sizes.
5141 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5143 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5144 its generated DWARF Call Frame Info. This encoding was causing GDB to
5145 panic, that panic has been fixed. Ref: gdb/1628.
5147 * Fixed a problem when examining parameters in shared library code.
5149 When examining parameters in optimized shared library code generated
5150 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5151 not available''. GDB now correctly displays the variable's value.
5153 *** Changes in GDB 6.1:
5155 * Removed --with-mmalloc
5157 Support for the mmalloc memory manager has been removed, as it
5158 conflicted with the internal gdb byte cache.
5160 * Changes in AMD64 configurations
5162 The AMD64 target now includes the %cs and %ss registers. As a result
5163 the AMD64 remote protocol has changed; this affects the floating-point
5164 and SSE registers. If you rely on those registers for your debugging,
5165 you should upgrade gdbserver on the remote side.
5167 * Revised SPARC target
5169 The SPARC target has been completely revised, incorporating the
5170 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5171 support for LynxOS and SunOS 4 has been dropped. Calling functions
5172 from within GDB on operating systems with a non-executable stack
5173 (Solaris, OpenBSD) now works.
5177 GDB has a new C++ demangler which does a better job on the mangled
5178 names generated by current versions of g++. It also runs faster, so
5179 with this and other changes gdb should now start faster on large C++
5182 * DWARF 2 Location Expressions
5184 GDB support for location expressions has been extended to support function
5185 arguments and frame bases. Older versions of GDB could crash when they
5188 * C++ nested types and namespaces
5190 GDB's support for nested types and namespaces in C++ has been
5191 improved, especially if you use the DWARF 2 debugging format. (This
5192 is the default for recent versions of GCC on most platforms.)
5193 Specifically, if you have a class "Inner" defined within a class or
5194 namespace "Outer", then GDB realizes that the class's name is
5195 "Outer::Inner", not simply "Inner". This should greatly reduce the
5196 frequency of complaints about not finding RTTI symbols. In addition,
5197 if you are stopped at inside of a function defined within a namespace,
5198 GDB modifies its name lookup accordingly.
5200 * New native configurations
5202 NetBSD/amd64 x86_64-*-netbsd*
5203 OpenBSD/amd64 x86_64-*-openbsd*
5204 OpenBSD/alpha alpha*-*-openbsd*
5205 OpenBSD/sparc sparc-*-openbsd*
5206 OpenBSD/sparc64 sparc64-*-openbsd*
5208 * New debugging protocols
5210 M32R with SDI protocol m32r-*-elf*
5212 * "set prompt-escape-char" command deleted.
5214 The command "set prompt-escape-char" has been deleted. This command,
5215 and its very obscure effet on GDB's prompt, was never documented,
5216 tested, nor mentioned in the NEWS file.
5218 * OBSOLETE configurations and files
5220 Configurations that have been declared obsolete in this release have
5221 been commented out. Unless there is activity to revive these
5222 configurations, the next release of GDB will have their sources
5223 permanently REMOVED.
5225 Sun 3, running SunOS 3 m68*-*-sunos3*
5226 Sun 3, running SunOS 4 m68*-*-sunos4*
5227 Sun 2, running SunOS 3 m68000-*-sunos3*
5228 Sun 2, running SunOS 4 m68000-*-sunos4*
5229 Motorola 680x0 running LynxOS m68*-*-lynxos*
5230 AT&T 3b1/Unix pc m68*-att-*
5231 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5232 decstation mips-dec-* mips-little-*
5233 riscos mips-*-riscos* mips-*-sysv*
5234 sonymips mips-sony-*
5235 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5237 * REMOVED configurations and files
5239 SGI Irix-4.x mips-sgi-irix4 or iris4
5240 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5241 Z8000 simulator z8k-zilog-none or z8ksim
5242 Matsushita MN10200 w/simulator mn10200-*-*
5243 H8/500 simulator h8500-hitachi-hms or h8500hms
5244 HP/PA running BSD hppa*-*-bsd*
5245 HP/PA running OSF/1 hppa*-*-osf*
5246 HP/PA Pro target hppa*-*-pro*
5247 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5248 386BSD i[3456]86-*-bsd*
5249 Sequent family i[3456]86-sequent-sysv4*
5250 i[3456]86-sequent-sysv*
5251 i[3456]86-sequent-bsd*
5252 SPARC running LynxOS sparc-*-lynxos*
5253 SPARC running SunOS 4 sparc-*-sunos4*
5254 Tsqware Sparclet sparclet-*-*
5255 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5257 *** Changes in GDB 6.0:
5261 Support for debugging the Objective-C programming language has been
5262 integrated into GDB.
5264 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5266 DWARF 2's Call Frame Information makes available compiler generated
5267 information that more exactly describes the program's run-time stack.
5268 By using this information, GDB is able to provide more robust stack
5271 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5272 have been updated to use a new backtrace mechanism which includes
5273 DWARF 2 CFI support.
5277 GDB's remote protocol has been extended to include support for hosted
5278 file I/O (where the remote target uses GDB's file system). See GDB's
5279 remote protocol documentation for details.
5281 * All targets using the new architecture framework.
5283 All of GDB's targets have been updated to use the new internal
5284 architecture framework. The way is now open for future GDB releases
5285 to include cross-architecture native debugging support (i386 on amd64,
5288 * GNU/Linux's Thread Local Storage (TLS)
5290 GDB now includes support for for the GNU/Linux implementation of
5291 per-thread variables.
5293 * GNU/Linux's Native POSIX Thread Library (NPTL)
5295 GDB's thread code has been updated to work with either the new
5296 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5298 * Separate debug info.
5300 GDB, in conjunction with BINUTILS, now supports a mechanism for
5301 automatically loading debug information from a separate file. Instead
5302 of shipping full debug and non-debug versions of system libraries,
5303 system integrators can now instead ship just the stripped libraries
5304 and optional debug files.
5306 * DWARF 2 Location Expressions
5308 DWARF 2 Location Expressions allow the compiler to more completely
5309 describe the location of variables (even in optimized code) to the
5312 GDB now includes preliminary support for location expressions (support
5313 for DW_OP_piece is still missing).
5317 A number of long standing bugs that caused GDB to die while starting a
5318 Java application have been fixed. GDB's Java support is now
5319 considered "useable".
5321 * GNU/Linux support for fork, vfork, and exec.
5323 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5324 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5327 * GDB supports logging output to a file
5329 There are two new commands, "set logging" and "show logging", which can be
5330 used to capture GDB's output to a file.
5332 * The meaning of "detach" has changed for gdbserver
5334 The "detach" command will now resume the application, as documented. To
5335 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5338 * d10v, m68hc11 `regs' command deprecated
5340 The `info registers' command has been updated so that it displays the
5341 registers using a format identical to the old `regs' command.
5345 A new command, "maint set profile on/off", has been added. This command can
5346 be used to enable or disable profiling while running GDB, to profile a
5347 session or a set of commands. In addition there is a new configure switch,
5348 "--enable-profiling", which will cause GDB to be compiled with profiling
5349 data, for more informative profiling results.
5351 * Default MI syntax changed to "mi2".
5353 The default MI (machine interface) syntax, enabled by the command line
5354 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5355 "mi1", can be enabled by specifying the option "-i=mi1".
5357 Support for the original "mi0" syntax (included in GDB 5.0) has been
5360 Fix for gdb/192: removed extraneous space when displaying frame level.
5361 Fix for gdb/672: update changelist is now output in mi list format.
5362 Fix for gdb/702: a -var-assign that updates the value now shows up
5363 in a subsequent -var-update.
5365 * New native configurations.
5367 FreeBSD/amd64 x86_64-*-freebsd*
5369 * Multi-arched targets.
5371 HP/PA HPUX11 hppa*-*-hpux*
5372 Renesas M32R/D w/simulator m32r-*-elf*
5374 * OBSOLETE configurations and files
5376 Configurations that have been declared obsolete in this release have
5377 been commented out. Unless there is activity to revive these
5378 configurations, the next release of GDB will have their sources
5379 permanently REMOVED.
5381 Z8000 simulator z8k-zilog-none or z8ksim
5382 Matsushita MN10200 w/simulator mn10200-*-*
5383 H8/500 simulator h8500-hitachi-hms or h8500hms
5384 HP/PA running BSD hppa*-*-bsd*
5385 HP/PA running OSF/1 hppa*-*-osf*
5386 HP/PA Pro target hppa*-*-pro*
5387 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5388 Sequent family i[3456]86-sequent-sysv4*
5389 i[3456]86-sequent-sysv*
5390 i[3456]86-sequent-bsd*
5391 Tsqware Sparclet sparclet-*-*
5392 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5394 * REMOVED configurations and files
5397 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5398 IBM AIX PS/2 i[3456]86-*-aix
5399 i386 running Mach 3.0 i[3456]86-*-mach3*
5400 i386 running Mach i[3456]86-*-mach*
5401 i386 running OSF/1 i[3456]86-*osf1mk*
5402 HP/Apollo 68k Family m68*-apollo*-sysv*,
5404 m68*-hp-bsd*, m68*-hp-hpux*
5405 Argonaut Risc Chip (ARC) arc-*-*
5406 Mitsubishi D30V d30v-*-*
5407 Fujitsu FR30 fr30-*-elf*
5408 OS/9000 i[34]86-*-os9k
5409 I960 with MON960 i960-*-coff
5411 * MIPS $fp behavior changed
5413 The convenience variable $fp, for the MIPS, now consistently returns
5414 the address of the current frame's base. Previously, depending on the
5415 context, $fp could refer to either $sp or the current frame's base
5416 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5417 The GNU Source-Level Debugger''.
5419 *** Changes in GDB 5.3:
5421 * GNU/Linux shared library multi-threaded performance improved.
5423 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5424 `/proc', in preference to `ptrace' for memory reads. This may result
5425 in an improvement in the start-up time of multi-threaded, shared
5426 library applications when run under GDB. One GDB user writes: ``loads
5427 shared libs like mad''.
5429 * ``gdbserver'' now supports multi-threaded applications on some targets
5431 Support for debugging multi-threaded applications which use
5432 the GNU/Linux LinuxThreads package has been added for
5433 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5434 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5436 * GDB now supports C/C++ preprocessor macros.
5438 GDB now expands preprocessor macro invocations in C/C++ expressions,
5439 and provides various commands for showing macro definitions and how
5442 The new command `macro expand EXPRESSION' expands any macro
5443 invocations in expression, and shows the result.
5445 The new command `show macro MACRO-NAME' shows the definition of the
5446 macro named MACRO-NAME, and where it was defined.
5448 Most compilers don't include information about macros in the debugging
5449 information by default. In GCC 3.1, for example, you need to compile
5450 your program with the options `-gdwarf-2 -g3'. If the macro
5451 information is present in the executable, GDB will read it.
5453 * Multi-arched targets.
5455 DEC Alpha (partial) alpha*-*-*
5456 DEC VAX (partial) vax-*-*
5458 National Semiconductor NS32000 (partial) ns32k-*-*
5459 Motorola 68000 (partial) m68k-*-*
5460 Motorola MCORE mcore-*-*
5464 Fujitsu FRV architecture added by Red Hat frv*-*-*
5467 * New native configurations
5469 Alpha NetBSD alpha*-*-netbsd*
5470 SH NetBSD sh*-*-netbsdelf*
5471 MIPS NetBSD mips*-*-netbsd*
5472 UltraSPARC NetBSD sparc64-*-netbsd*
5474 * OBSOLETE configurations and files
5476 Configurations that have been declared obsolete in this release have
5477 been commented out. Unless there is activity to revive these
5478 configurations, the next release of GDB will have their sources
5479 permanently REMOVED.
5481 Mitsubishi D30V d30v-*-*
5482 OS/9000 i[34]86-*-os9k
5483 IBM AIX PS/2 i[3456]86-*-aix
5484 Fujitsu FR30 fr30-*-elf*
5485 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5486 Argonaut Risc Chip (ARC) arc-*-*
5487 i386 running Mach 3.0 i[3456]86-*-mach3*
5488 i386 running Mach i[3456]86-*-mach*
5489 i386 running OSF/1 i[3456]86-*osf1mk*
5490 HP/Apollo 68k Family m68*-apollo*-sysv*,
5492 m68*-hp-bsd*, m68*-hp-hpux*
5493 I960 with MON960 i960-*-coff
5495 * OBSOLETE languages
5497 CHILL, a Pascal like language used by telecommunications companies.
5499 * REMOVED configurations and files
5501 AMD 29k family via UDI a29k-amd-udi, udi29k
5502 A29K VxWorks a29k-*-vxworks
5503 AMD 29000 embedded, using EBMON a29k-none-none
5504 AMD 29000 embedded with COFF a29k-none-coff
5505 AMD 29000 embedded with a.out a29k-none-aout
5507 testsuite/gdb.hp/gdb.threads-hp/ directory
5509 * New command "set max-user-call-depth <nnn>"
5511 This command allows the user to limit the call depth of user-defined
5512 commands. The default is 1024.
5514 * Changes in FreeBSD/i386 native debugging.
5516 Support for the "generate-core-file" has been added.
5518 * New commands "dump", "append", and "restore".
5520 These commands allow data to be copied from target memory
5521 to a bfd-format or binary file (dump and append), and back
5522 from a file into memory (restore).
5524 * Improved "next/step" support on multi-processor Alpha Tru64.
5526 The previous single-step mechanism could cause unpredictable problems,
5527 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5528 of a software single-step mechanism prevents this.
5530 *** Changes in GDB 5.2.1:
5538 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5539 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5540 Fix, by Joel Brobecker imported from mainline.
5542 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5543 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5544 Fix, by Fred Fish, imported from mainline.
5546 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5547 Surprisingly enough, it works now.
5548 By Michal Ludvig, imported from mainline.
5550 i386 hardware watchpoint support:
5551 avoid misses on second run for some targets.
5552 By Pierre Muller, imported from mainline.
5554 *** Changes in GDB 5.2:
5556 * New command "set trust-readonly-sections on[off]".
5558 This command is a hint that tells gdb that read-only sections
5559 really are read-only (ie. that their contents will not change).
5560 In this mode, gdb will go to the object file rather than the
5561 target to read memory from read-only sections (such as ".text").
5562 This can be a significant performance improvement on some
5563 (notably embedded) targets.
5565 * New command "generate-core-file" (or "gcore").
5567 This new gdb command allows the user to drop a core file of the child
5568 process state at any time. So far it's been implemented only for
5569 GNU/Linux and Solaris, but should be relatively easily ported to other
5570 hosts. Argument is core file name (defaults to core.<pid>).
5572 * New command line option
5574 GDB now accepts --pid or -p followed by a process id.
5576 * Change in command line behavior -- corefiles vs. process ids.
5578 There is a subtle behavior in the way in which GDB handles
5579 command line arguments. The first non-flag argument is always
5580 a program to debug, but the second non-flag argument may either
5581 be a corefile or a process id. Previously, GDB would attempt to
5582 open the second argument as a corefile, and if that failed, would
5583 issue a superfluous error message and then attempt to attach it as
5584 a process. Now, if the second argument begins with a non-digit,
5585 it will be treated as a corefile. If it begins with a digit,
5586 GDB will attempt to attach it as a process, and if no such process
5587 is found, will then attempt to open it as a corefile.
5589 * Changes in ARM configurations.
5591 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5592 configuration is fully multi-arch.
5594 * New native configurations
5596 ARM NetBSD arm*-*-netbsd*
5597 x86 OpenBSD i[3456]86-*-openbsd*
5598 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5599 Sparc64 running FreeBSD sparc64-*-freebsd*
5603 Sanyo XStormy16 xstormy16-elf
5605 * OBSOLETE configurations and files
5607 Configurations that have been declared obsolete in this release have
5608 been commented out. Unless there is activity to revive these
5609 configurations, the next release of GDB will have their sources
5610 permanently REMOVED.
5612 AMD 29k family via UDI a29k-amd-udi, udi29k
5613 A29K VxWorks a29k-*-vxworks
5614 AMD 29000 embedded, using EBMON a29k-none-none
5615 AMD 29000 embedded with COFF a29k-none-coff
5616 AMD 29000 embedded with a.out a29k-none-aout
5618 testsuite/gdb.hp/gdb.threads-hp/ directory
5620 * REMOVED configurations and files
5622 TI TMS320C80 tic80-*-*
5624 PowerPC Solaris powerpcle-*-solaris*
5625 PowerPC Windows NT powerpcle-*-cygwin32
5626 PowerPC Netware powerpc-*-netware*
5627 Harris/CXUX m88k m88*-harris-cxux*
5628 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5629 ns32k-utek-sysv* ns32k-utek-*
5630 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5631 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5632 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5633 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5634 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5636 * Changes to command line processing
5638 The new `--args' feature can be used to specify command-line arguments
5639 for the inferior from gdb's command line.
5641 * Changes to key bindings
5643 There is a new `operate-and-get-next' function bound to `C-o'.
5645 *** Changes in GDB 5.1.1
5647 Fix compile problem on DJGPP.
5649 Fix a problem with floating-point registers on the i386 being
5652 Fix to stop GDB crashing on .debug_str debug info.
5654 Numerous documentation fixes.
5656 Numerous testsuite fixes.
5658 *** Changes in GDB 5.1:
5660 * New native configurations
5662 Alpha FreeBSD alpha*-*-freebsd*
5663 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5664 MIPS GNU/Linux mips*-*-linux*
5665 MIPS SGI Irix 6.x mips*-sgi-irix6*
5666 ia64 AIX ia64-*-aix*
5667 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5671 Motorola 68HC11 and 68HC12 m68hc11-elf
5673 UltraSparc running GNU/Linux sparc64-*-linux*
5675 * OBSOLETE configurations and files
5677 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5678 Harris/CXUX m88k m88*-harris-cxux*
5679 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5680 ns32k-utek-sysv* ns32k-utek-*
5681 TI TMS320C80 tic80-*-*
5683 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5684 PowerPC Solaris powerpcle-*-solaris*
5685 PowerPC Windows NT powerpcle-*-cygwin32
5686 PowerPC Netware powerpc-*-netware*
5687 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5688 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5689 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5690 Apple Macintosh (MPW) host N/A
5692 stuff.c (Program to stuff files into a specially prepared space in kdb)
5693 kdb-start.c (Main loop for the standalone kernel debugger)
5695 Configurations that have been declared obsolete in this release have
5696 been commented out. Unless there is activity to revive these
5697 configurations, the next release of GDB will have their sources
5698 permanently REMOVED.
5700 * REMOVED configurations and files
5702 Altos 3068 m68*-altos-*
5703 Convex c1-*-*, c2-*-*
5705 ARM RISCix arm-*-* (as host)
5709 * GDB has been converted to ISO C.
5711 GDB's source code has been converted to ISO C. In particular, the
5712 sources are fully protoized, and rely on standard headers being
5717 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5719 * The MI enabled by default.
5721 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5722 revised and enabled by default. Packages which use GDB as a debugging
5723 engine behind a UI or another front end are encouraged to switch to
5724 using the GDB/MI interface, instead of the old annotations interface
5725 which is now deprecated.
5727 * Support for debugging Pascal programs.
5729 GDB now includes support for debugging Pascal programs. The following
5730 main features are supported:
5732 - Pascal-specific data types such as sets;
5734 - automatic recognition of Pascal sources based on file-name
5737 - Pascal-style display of data types, variables, and functions;
5739 - a Pascal expression parser.
5741 However, some important features are not yet supported.
5743 - Pascal string operations are not supported at all;
5745 - there are some problems with boolean types;
5747 - Pascal type hexadecimal constants are not supported
5748 because they conflict with the internal variables format;
5750 - support for Pascal objects and classes is not full yet;
5752 - unlike Pascal, GDB is case-sensitive for symbol names.
5754 * Changes in completion.
5756 Commands such as `shell', `run' and `set args', which pass arguments
5757 to inferior programs, now complete on file names, similar to what
5758 users expect at the shell prompt.
5760 Commands which accept locations, such as `disassemble', `print',
5761 `breakpoint', `until', etc. now complete on filenames as well as
5762 program symbols. Thus, if you type "break foob TAB", and the source
5763 files linked into the programs include `foobar.c', that file name will
5764 be one of the candidates for completion. However, file names are not
5765 considered for completion after you typed a colon that delimits a file
5766 name from a name of a function in that file, as in "break foo.c:bar".
5768 `set demangle-style' completes on available demangling styles.
5770 * New platform-independent commands:
5772 It is now possible to define a post-hook for a command as well as a
5773 hook that runs before the command. For more details, see the
5774 documentation of `hookpost' in the GDB manual.
5776 * Changes in GNU/Linux native debugging.
5778 Support for debugging multi-threaded programs has been completely
5779 revised for all platforms except m68k and sparc. You can now debug as
5780 many threads as your system allows you to have.
5782 Attach/detach is supported for multi-threaded programs.
5784 Support for SSE registers was added for x86. This doesn't work for
5785 multi-threaded programs though.
5787 * Changes in MIPS configurations.
5789 Multi-arch support is enabled for all MIPS configurations.
5791 GDB can now be built as native debugger on SGI Irix 6.x systems for
5792 debugging n32 executables. (Debugging 64-bit executables is not yet
5795 * Unified support for hardware watchpoints in all x86 configurations.
5797 Most (if not all) native x86 configurations support hardware-assisted
5798 breakpoints and watchpoints in a unified manner. This support
5799 implements debug register sharing between watchpoints, which allows to
5800 put a virtually infinite number of watchpoints on the same address,
5801 and also supports watching regions up to 16 bytes with several debug
5804 The new maintenance command `maintenance show-debug-regs' toggles
5805 debugging print-outs in functions that insert, remove, and test
5806 watchpoints and hardware breakpoints.
5808 * Changes in the DJGPP native configuration.
5810 New command ``info dos sysinfo'' displays assorted information about
5811 the CPU, OS, memory, and DPMI server.
5813 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5814 display information about segment descriptors stored in GDT, LDT, and
5817 New commands ``info dos pde'' and ``info dos pte'' display entries
5818 from Page Directory and Page Tables (for now works with CWSDPMI only).
5819 New command ``info dos address-pte'' displays the Page Table entry for
5820 a given linear address.
5822 GDB can now pass command lines longer than 126 characters to the
5823 program being debugged (requires an update to the libdbg.a library
5824 which is part of the DJGPP development kit).
5826 DWARF2 debug info is now supported.
5828 It is now possible to `step' and `next' through calls to `longjmp'.
5830 * Changes in documentation.
5832 All GDB documentation was converted to GFDL, the GNU Free
5833 Documentation License.
5835 Tracepoints-related commands are now fully documented in the GDB
5838 TUI, the Text-mode User Interface, is now documented in the manual.
5840 Tracepoints-related commands are now fully documented in the GDB
5843 The "GDB Internals" manual now has an index. It also includes
5844 documentation of `ui_out' functions, GDB coding standards, x86
5845 hardware watchpoints, and memory region attributes.
5847 * GDB's version number moved to ``version.in''
5849 The Makefile variable VERSION has been replaced by the file
5850 ``version.in''. People creating GDB distributions should update the
5851 contents of this file.
5855 GUD support is now a standard part of the EMACS distribution.
5857 *** Changes in GDB 5.0:
5859 * Improved support for debugging FP programs on x86 targets
5861 Unified and much-improved support for debugging floating-point
5862 programs on all x86 targets. In particular, ``info float'' now
5863 displays the FP registers in the same format on all x86 targets, with
5864 greater level of detail.
5866 * Improvements and bugfixes in hardware-assisted watchpoints
5868 It is now possible to watch array elements, struct members, and
5869 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5870 on x86 targets no longer erroneously trigger when the address is
5873 * Improvements in the native DJGPP version of GDB
5875 The distribution now includes all the scripts and auxiliary files
5876 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5877 machines ``out of the box''.
5879 The DJGPP version can now debug programs that use signals. It is
5880 possible to catch signals that happened in the debuggee, deliver
5881 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5882 would kill the program being debugged.) Programs that hook hardware
5883 interrupts (keyboard, timer, etc.) can also be debugged.
5885 It is now possible to debug DJGPP programs that redirect their
5886 standard handles or switch them to raw (as opposed to cooked) mode, or
5887 even close them. The command ``run < foo > bar'' works as expected,
5888 and ``info terminal'' reports useful information about the debuggee's
5889 terminal, including raw/cooked mode, redirection, etc.
5891 The DJGPP version now uses termios functions for console I/O, which
5892 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5895 DOS-style file names with drive letters are now fully supported by
5898 It is now possible to debug DJGPP programs that switch their working
5899 directory. It is also possible to rerun the debuggee any number of
5900 times without restarting GDB; thus, you can use the same setup,
5901 breakpoints, etc. for many debugging sessions.
5903 * New native configurations
5905 ARM GNU/Linux arm*-*-linux*
5906 PowerPC GNU/Linux powerpc-*-linux*
5910 Motorola MCore mcore-*-*
5911 x86 VxWorks i[3456]86-*-vxworks*
5912 PowerPC VxWorks powerpc-*-vxworks*
5913 TI TMS320C80 tic80-*-*
5915 * OBSOLETE configurations
5917 Altos 3068 m68*-altos-*
5918 Convex c1-*-*, c2-*-*
5920 ARM RISCix arm-*-* (as host)
5923 Configurations that have been declared obsolete will be commented out,
5924 but the code will be left in place. If there is no activity to revive
5925 these configurations before the next release of GDB, the sources will
5926 be permanently REMOVED.
5928 * Gould support removed
5930 Support for the Gould PowerNode and NP1 has been removed.
5932 * New features for SVR4
5934 On SVR4 native platforms (such as Solaris), if you attach to a process
5935 without first loading a symbol file, GDB will now attempt to locate and
5936 load symbols from the running process's executable file.
5938 * Many C++ enhancements
5940 C++ support has been greatly improved. Overload resolution now works properly
5941 in almost all cases. RTTI support is on the way.
5943 * Remote targets can connect to a sub-program
5945 A popen(3) style serial-device has been added. This device starts a
5946 sub-process (such as a stand-alone simulator) and then communicates
5947 with that. The sub-program to run is specified using the syntax
5948 ``|<program> <args>'' vis:
5950 (gdb) set remotedebug 1
5951 (gdb) target extended-remote |mn10300-elf-sim program-args
5953 * MIPS 64 remote protocol
5955 A long standing bug in the mips64 remote protocol where by GDB
5956 expected certain 32 bit registers (ex SR) to be transfered as 32
5957 instead of 64 bits has been fixed.
5959 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5960 added to provide backward compatibility with older versions of GDB.
5962 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5964 The command ``set remotebinarydownload'' command has been replaced by
5965 ``set remote X-packet''. Other commands in ``set remote'' family
5966 include ``set remote P-packet''.
5968 * Breakpoint commands accept ranges.
5970 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5971 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5972 ``tracepoint passcount'' also accepts a range of tracepoints.
5974 * ``apropos'' command added.
5976 The ``apropos'' command searches through command names and
5977 documentation strings, printing out matches, making it much easier to
5978 try to find a command that does what you are looking for.
5982 A new machine oriented interface (MI) has been added to GDB. This
5983 interface is designed for debug environments running GDB as a separate
5984 process. This is part of the long term libGDB project. See the
5985 "GDB/MI" chapter of the GDB manual for further information. It can be
5986 enabled by configuring with:
5988 .../configure --enable-gdbmi
5990 *** Changes in GDB-4.18:
5992 * New native configurations
5994 HP-UX 10.20 hppa*-*-hpux10.20
5995 HP-UX 11.x hppa*-*-hpux11.0*
5996 M68K GNU/Linux m68*-*-linux*
6000 Fujitsu FR30 fr30-*-elf*
6001 Intel StrongARM strongarm-*-*
6002 Mitsubishi D30V d30v-*-*
6004 * OBSOLETE configurations
6006 Gould PowerNode, NP1 np1-*-*, pn-*-*
6008 Configurations that have been declared obsolete will be commented out,
6009 but the code will be left in place. If there is no activity to revive
6010 these configurations before the next release of GDB, the sources will
6011 be permanently REMOVED.
6015 As a compatibility experiment, GDB's source files buildsym.h and
6016 buildsym.c have been converted to pure standard C, no longer
6017 containing any K&R compatibility code. We believe that all systems in
6018 use today either come with a standard C compiler, or have a GCC port
6019 available. If this is not true, please report the affected
6020 configuration to bug-gdb@gnu.org immediately. See the README file for
6021 information about getting a standard C compiler if you don't have one
6026 GDB now uses readline 2.2.
6028 * set extension-language
6030 You can now control the mapping between filename extensions and source
6031 languages by using the `set extension-language' command. For instance,
6032 you can ask GDB to treat .c files as C++ by saying
6033 set extension-language .c c++
6034 The command `info extensions' lists all of the recognized extensions
6035 and their associated languages.
6037 * Setting processor type for PowerPC and RS/6000
6039 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6040 you can use the `set processor' command to specify what variant of the
6041 PowerPC family you are debugging. The command
6045 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6046 following PowerPC and RS6000 variants:
6048 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6049 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6051 403GC IBM PowerPC 403GC
6052 505 Motorola PowerPC 505
6053 860 Motorola PowerPC 860 or 850
6054 601 Motorola PowerPC 601
6055 602 Motorola PowerPC 602
6056 603 Motorola/IBM PowerPC 603 or 603e
6057 604 Motorola PowerPC 604 or 604e
6058 750 Motorola/IBM PowerPC 750 or 750
6060 At the moment, this command just tells GDB what to name the
6061 special-purpose processor registers. Since almost all the affected
6062 registers are inaccessible to user-level programs, this command is
6063 only useful for remote debugging in its present form.
6067 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6068 more extensive support for HP-UX. Added features include shared
6069 library support, kernel threads and hardware watchpoints for 11.00,
6070 support for HP's ANSI C and C++ compilers, and a compatibility mode
6071 for xdb and dbx commands.
6075 HP's donation includes the new concept of catchpoints, which is a
6076 generalization of the old catch command. On HP-UX, it is now possible
6077 to catch exec, fork, and vfork, as well as library loading.
6079 This means that the existing catch command has changed; its first
6080 argument now specifies the type of catch to be set up. See the
6081 output of "help catch" for a list of catchpoint types.
6083 * Debugging across forks
6085 On HP-UX, you can choose which process to debug when a fork() happens
6090 HP has donated a curses-based terminal user interface (TUI). To get
6091 it, build with --enable-tui. Although this can be enabled for any
6092 configuration, at present it only works for native HP debugging.
6094 * GDB remote protocol additions
6096 A new protocol packet 'X' that writes binary data is now available.
6097 Default behavior is to try 'X', then drop back to 'M' if the stub
6098 fails to respond. The settable variable `remotebinarydownload'
6099 allows explicit control over the use of 'X'.
6101 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6102 full 64-bit address. The command
6104 set remoteaddresssize 32
6106 can be used to revert to the old behaviour. For existing remote stubs
6107 the change should not be noticed, as the additional address information
6110 In order to assist in debugging stubs, you may use the maintenance
6111 command `packet' to send any text string to the stub. For instance,
6113 maint packet heythere
6115 sends the packet "$heythere#<checksum>". Note that it is very easy to
6116 disrupt a debugging session by sending the wrong packet at the wrong
6119 The compare-sections command allows you to compare section data on the
6120 target to what is in the executable file without uploading or
6121 downloading, by comparing CRC checksums.
6123 * Tracing can collect general expressions
6125 You may now collect general expressions at tracepoints. This requires
6126 further additions to the target-side stub; see tracepoint.c and
6127 doc/agentexpr.texi for further details.
6129 * mask-address variable for Mips
6131 For Mips targets, you may control the zeroing of the upper 32 bits of
6132 a 64-bit address by entering `set mask-address on'. This is mainly
6133 of interest to users of embedded R4xxx and R5xxx processors.
6135 * Higher serial baud rates
6137 GDB's serial code now allows you to specify baud rates 57600, 115200,
6138 230400, and 460800 baud. (Note that your host system may not be able
6139 to achieve all of these rates.)
6143 The i960 configuration now includes an initial implementation of a
6144 builtin simulator, contributed by Jim Wilson.
6147 *** Changes in GDB-4.17:
6149 * New native configurations
6151 Alpha GNU/Linux alpha*-*-linux*
6152 Unixware 2.x i[3456]86-unixware2*
6153 Irix 6.x mips*-sgi-irix6*
6154 PowerPC GNU/Linux powerpc-*-linux*
6155 PowerPC Solaris powerpcle-*-solaris*
6156 Sparc GNU/Linux sparc-*-linux*
6157 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6161 Argonaut Risc Chip (ARC) arc-*-*
6162 Hitachi H8/300S h8300*-*-*
6163 Matsushita MN10200 w/simulator mn10200-*-*
6164 Matsushita MN10300 w/simulator mn10300-*-*
6165 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6166 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6167 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6168 Mitsubishi D10V w/simulator d10v-*-*
6169 Mitsubishi M32R/D w/simulator m32r-*-elf*
6170 Tsqware Sparclet sparclet-*-*
6171 NEC V850 w/simulator v850-*-*
6173 * New debugging protocols
6175 ARM with RDI protocol arm*-*-*
6176 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6177 DDB and LSI variants of PMON protocol mips*-*-*
6178 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6179 PowerPC with SDS protocol powerpc{,le}-*-eabi
6180 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6184 All configurations can now understand and use the DWARF 2 debugging
6185 format. The choice is automatic, if the symbol file contains DWARF 2
6190 GDB now includes basic Java language support. This support is
6191 only useful with Java compilers that produce native machine code.
6193 * solib-absolute-prefix and solib-search-path
6195 For SunOS and SVR4 shared libraries, you may now set the prefix for
6196 loading absolute shared library symbol files, and the search path for
6197 locating non-absolute shared library symbol files.
6199 * Live range splitting
6201 GDB can now effectively debug code for which GCC has performed live
6202 range splitting as part of its optimization. See gdb/doc/LRS for
6203 more details on the expected format of the stabs information.
6207 GDB's support for the GNU Hurd, including thread debugging, has been
6208 updated to work with current versions of the Hurd.
6212 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6213 instruction set. ARM GDB automatically detects when Thumb
6214 instructions are in use, and adjusts disassembly and backtracing
6219 GDB's MIPS target configurations now handle the MIP16 16-bit
6224 GDB now includes support for overlays; if an executable has been
6225 linked such that multiple sections are based at the same address, GDB
6226 will decide which section to use for symbolic info. You can choose to
6227 control the decision manually, using overlay commands, or implement
6228 additional target-side support and use "overlay load-target" to bring
6229 in the overlay mapping. Do "help overlay" for more detail.
6233 The command "info symbol <address>" displays information about
6234 the symbol at the specified address.
6238 The standard remote protocol now includes an extension that allows
6239 asynchronous collection and display of trace data. This requires
6240 extensive support in the target-side debugging stub. Tracing mode
6241 includes a new interaction mode in GDB and new commands: see the
6242 file tracepoint.c for more details.
6246 Configurations for embedded MIPS now include a simulator contributed
6247 by Cygnus Solutions. The simulator supports the instruction sets
6248 of most MIPS variants.
6252 Sparc configurations may now include the ERC32 simulator contributed
6253 by the European Space Agency. The simulator is not built into
6254 Sparc targets by default; configure with --enable-sim to include it.
6258 For target configurations that may include multiple variants of a
6259 basic architecture (such as MIPS and SH), you may now set the
6260 architecture explicitly. "set arch" sets, "info arch" lists
6261 the possible architectures.
6263 *** Changes in GDB-4.16:
6265 * New native configurations
6267 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6268 M68K NetBSD m68k-*-netbsd*
6269 PowerPC AIX 4.x powerpc-*-aix*
6270 PowerPC MacOS powerpc-*-macos*
6271 PowerPC Windows NT powerpcle-*-cygwin32
6272 RS/6000 AIX 4.x rs6000-*-aix4*
6276 ARM with RDP protocol arm-*-*
6277 I960 with MON960 i960-*-coff
6278 MIPS VxWorks mips*-*-vxworks*
6279 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6280 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6282 Matra Sparclet sparclet-*-*
6286 The powerpc-eabi configuration now includes the PSIM simulator,
6287 contributed by Andrew Cagney, with assistance from Mike Meissner.
6288 PSIM is a very elaborate model of the PowerPC, including not only
6289 basic instruction set execution, but also details of execution unit
6290 performance and I/O hardware. See sim/ppc/README for more details.
6294 GDB now works with Solaris 2.5.
6296 * Windows 95/NT native
6298 GDB will now work as a native debugger on Windows 95 and Windows NT.
6299 To build it from source, you must use the "gnu-win32" environment,
6300 which uses a DLL to emulate enough of Unix to run the GNU tools.
6301 Further information, binaries, and sources are available at
6302 ftp.cygnus.com, under pub/gnu-win32.
6304 * dont-repeat command
6306 If a user-defined command includes the command `dont-repeat', then the
6307 command will not be repeated if the user just types return. This is
6308 useful if the command is time-consuming to run, so that accidental
6309 extra keystrokes don't run the same command many times.
6311 * Send break instead of ^C
6313 The standard remote protocol now includes an option to send a break
6314 rather than a ^C to the target in order to interrupt it. By default,
6315 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6317 * Remote protocol timeout
6319 The standard remote protocol includes a new variable `remotetimeout'
6320 that allows you to set the number of seconds before GDB gives up trying
6321 to read from the target. The default value is 2.
6323 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6325 By default GDB will automatically keep track of objects as they are
6326 loaded and unloaded by the dynamic linker. By using the command `set
6327 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6328 when shared library events occur, thus allowing you to set breakpoints
6329 in shared libraries which are explicitly loaded by the inferior.
6331 Note this feature does not work on hpux8. On hpux9 you must link
6332 /usr/lib/end.o into your program. This feature should work
6333 automatically on hpux10.
6335 * Irix 5.x hardware watchpoint support
6337 Irix 5 configurations now support the use of hardware watchpoints.
6339 * Mips protocol "SYN garbage limit"
6341 When debugging a Mips target using the `target mips' protocol, you
6342 may set the number of characters that GDB will ignore by setting
6343 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6344 every character. The default value is 1050.
6346 * Recording and replaying remote debug sessions
6348 If you set `remotelogfile' to the name of a file, gdb will write to it
6349 a recording of a remote debug session. This recording may then be
6350 replayed back to gdb using "gdbreplay". See gdbserver/README for
6351 details. This is useful when you have a problem with GDB while doing
6352 remote debugging; you can make a recording of the session and send it
6353 to someone else, who can then recreate the problem.
6355 * Speedups for remote debugging
6357 GDB includes speedups for downloading and stepping MIPS systems using
6358 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6359 and more efficient S-record downloading.
6361 * Memory use reductions and statistics collection
6363 GDB now uses less memory and reports statistics about memory usage.
6364 Try the `maint print statistics' command, for example.
6366 *** Changes in GDB-4.15:
6368 * Psymtabs for XCOFF
6370 The symbol reader for AIX GDB now uses partial symbol tables. This
6371 can greatly improve startup time, especially for large executables.
6373 * Remote targets use caching
6375 Remote targets now use a data cache to speed up communication with the
6376 remote side. The data cache could lead to incorrect results because
6377 it doesn't know about volatile variables, thus making it impossible to
6378 debug targets which use memory mapped I/O devices. `set remotecache
6379 off' turns the the data cache off.
6381 * Remote targets may have threads
6383 The standard remote protocol now includes support for multiple threads
6384 in the target system, using new protocol commands 'H' and 'T'. See
6385 gdb/remote.c for details.
6389 If GDB is configured with `--enable-netrom', then it will include
6390 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6391 acts as though it is a bank of ROM on the target board, but you can
6392 write into it over the network. GDB's support consists only of
6393 support for fast loading into the emulated ROM; to debug, you must use
6394 another protocol, such as standard remote protocol. The usual
6395 sequence is something like
6397 target nrom <netrom-hostname>
6399 target remote <netrom-hostname>:1235
6403 GDB now includes support for the Apple Macintosh, as a host only. It
6404 may be run as either an MPW tool or as a standalone application, and
6405 it can debug through the serial port. All the usual GDB commands are
6406 available, but to the target command, you must supply "serial" as the
6407 device type instead of "/dev/ttyXX". See mpw-README in the main
6408 directory for more information on how to build. The MPW configuration
6409 scripts */mpw-config.in support only a few targets, and only the
6410 mips-idt-ecoff target has been tested.
6414 GDB configuration now uses autoconf. This is not user-visible,
6415 but does simplify configuration and building.
6419 GDB now supports hpux10.
6421 *** Changes in GDB-4.14:
6423 * New native configurations
6425 x86 FreeBSD i[345]86-*-freebsd
6426 x86 NetBSD i[345]86-*-netbsd
6427 NS32k NetBSD ns32k-*-netbsd
6428 Sparc NetBSD sparc-*-netbsd
6432 A29K VxWorks a29k-*-vxworks
6433 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6434 CPU32 EST-300 emulator m68*-*-est*
6435 PowerPC ELF powerpc-*-elf
6438 * Alpha OSF/1 support for procfs
6440 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6441 possible to attach to running processes. As the mounting of the /proc
6442 filesystem is optional on the Alpha, GDB automatically determines
6443 the availability of /proc during startup. This can lead to problems
6444 if /proc is unmounted after GDB has been started.
6446 * Arguments to user-defined commands
6448 User commands may accept up to 10 arguments separated by whitespace.
6449 Arguments are accessed within the user command via $arg0..$arg9. A
6452 print $arg0 + $arg1 + $arg2
6454 To execute the command use:
6457 Defines the command "adder" which prints the sum of its three arguments.
6458 Note the arguments are text substitutions, so they may reference variables,
6459 use complex expressions, or even perform inferior function calls.
6461 * New `if' and `while' commands
6463 This makes it possible to write more sophisticated user-defined
6464 commands. Both commands take a single argument, which is the
6465 expression to evaluate, and must be followed by the commands to
6466 execute, one per line, if the expression is nonzero, the list being
6467 terminated by the word `end'. The `if' command list may include an
6468 `else' word, which causes the following commands to be executed only
6469 if the expression is zero.
6471 * Fortran source language mode
6473 GDB now includes partial support for Fortran 77. It will recognize
6474 Fortran programs and can evaluate a subset of Fortran expressions, but
6475 variables and functions may not be handled correctly. GDB will work
6476 with G77, but does not yet know much about symbols emitted by other
6479 * Better HPUX support
6481 Most debugging facilities now work on dynamic executables for HPPAs
6482 running hpux9 or later. You can attach to running dynamically linked
6483 processes, but by default the dynamic libraries will be read-only, so
6484 for instance you won't be able to put breakpoints in them. To change
6485 that behavior do the following before running the program:
6491 This will cause the libraries to be mapped private and read-write.
6492 To revert to the normal behavior, do this:
6498 You cannot set breakpoints or examine data in the library until after
6499 the library is loaded if the function/data symbols do not have
6502 GDB can now also read debug symbols produced by the HP C compiler on
6503 HPPAs (sorry, no C++, Fortran or 68k support).
6505 * Target byte order now dynamically selectable
6507 You can choose which byte order to use with a target system, via the
6508 commands "set endian big" and "set endian little", and you can see the
6509 current setting by using "show endian". You can also give the command
6510 "set endian auto", in which case GDB will use the byte order
6511 associated with the executable. Currently, only embedded MIPS
6512 configurations support dynamic selection of target byte order.
6514 * New DOS host serial code
6516 This version uses DPMI interrupts to handle buffered I/O, so you
6517 no longer need to run asynctsr when debugging boards connected to
6520 *** Changes in GDB-4.13:
6522 * New "complete" command
6524 This lists all the possible completions for the rest of the line, if it
6525 were to be given as a command itself. This is intended for use by emacs.
6527 * Trailing space optional in prompt
6529 "set prompt" no longer adds a space for you after the prompt you set. This
6530 allows you to set a prompt which ends in a space or one that does not.
6532 * Breakpoint hit counts
6534 "info break" now displays a count of the number of times the breakpoint
6535 has been hit. This is especially useful in conjunction with "ignore"; you
6536 can ignore a large number of breakpoint hits, look at the breakpoint info
6537 to see how many times the breakpoint was hit, then run again, ignoring one
6538 less than that number, and this will get you quickly to the last hit of
6541 * Ability to stop printing at NULL character
6543 "set print null-stop" will cause GDB to stop printing the characters of
6544 an array when the first NULL is encountered. This is useful when large
6545 arrays actually contain only short strings.
6547 * Shared library breakpoints
6549 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6550 breakpoints in shared libraries before the executable is run.
6552 * Hardware watchpoints
6554 There is a new hardware breakpoint for the watch command for sparclite
6555 targets. See gdb/sparclite/hw_breakpoint.note.
6557 Hardware watchpoints are also now supported under GNU/Linux.
6561 Annotations have been added. These are for use with graphical interfaces,
6562 and are still experimental. Currently only gdba.el uses these.
6564 * Improved Irix 5 support
6566 GDB now works properly with Irix 5.2.
6568 * Improved HPPA support
6570 GDB now works properly with the latest GCC and GAS.
6572 * New native configurations
6574 Sequent PTX4 i[34]86-sequent-ptx4
6575 HPPA running OSF/1 hppa*-*-osf*
6576 Atari TT running SVR4 m68*-*-sysv4*
6577 RS/6000 LynxOS rs6000-*-lynxos*
6581 OS/9000 i[34]86-*-os9k
6582 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6585 * Hitachi SH7000 and E7000-PC ICE support
6587 There is now support for communicating with the Hitachi E7000-PC ICE.
6588 This is available automatically when GDB is configured for the SH.
6592 As usual, a variety of small fixes and improvements, both generic
6593 and configuration-specific. See the ChangeLog for more detail.
6595 *** Changes in GDB-4.12:
6597 * Irix 5 is now supported
6601 GDB-4.12 on the HPPA has a number of changes which make it unable
6602 to debug the output from the currently released versions of GCC and
6603 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6604 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6605 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6608 *** Changes in GDB-4.11:
6610 * User visible changes:
6614 The "set remotedebug" option is now consistent between the mips remote
6615 target, remote targets using the gdb-specific protocol, UDI (AMD's
6616 debug protocol for the 29k) and the 88k bug monitor. It is now an
6617 integer specifying a debug level (normally 0 or 1, but 2 means more
6618 debugging info for the mips target).
6620 * DEC Alpha native support
6622 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6623 debug info, but GDB works fairly well with the DEC compiler and should
6624 work with a future GCC release. See the README file for a few
6625 Alpha-specific notes.
6627 * Preliminary thread implementation
6629 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6631 * LynxOS native and target support for 386
6633 This release has been hosted on LynxOS 2.2, and also can be configured
6634 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6637 * Improvements in C++ mangling/demangling.
6639 This release has much better g++ debugging, specifically in name
6640 mangling/demangling, virtual function calls, print virtual table,
6641 call methods, ...etc.
6643 *** Changes in GDB-4.10:
6645 * User visible changes:
6647 Remote debugging using the GDB-specific (`target remote') protocol now
6648 supports the `load' command. This is only useful if you have some
6649 other way of getting the stub to the target system, and you can put it
6650 somewhere in memory where it won't get clobbered by the download.
6652 Filename completion now works.
6654 When run under emacs mode, the "info line" command now causes the
6655 arrow to point to the line specified. Also, "info line" prints
6656 addresses in symbolic form (as well as hex).
6658 All vxworks based targets now support a user settable option, called
6659 vxworks-timeout. This option represents the number of seconds gdb
6660 should wait for responses to rpc's. You might want to use this if
6661 your vxworks target is, perhaps, a slow software simulator or happens
6662 to be on the far side of a thin network line.
6666 This release contains support for using a DEC alpha as a GDB host for
6667 cross debugging. Native alpha debugging is not supported yet.
6670 *** Changes in GDB-4.9:
6674 This is the first GDB release which is accompanied by a matching testsuite.
6675 The testsuite requires installation of dejagnu, which should be available
6676 via ftp from most sites that carry GNU software.
6680 'Cfront' style demangling has had its name changed to 'ARM' style, to
6681 emphasize that it was written from the specifications in the C++ Annotated
6682 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6683 disclaimers, it still generated too much confusion with users attempting to
6684 use gdb with AT&T cfront.
6688 GDB now uses a standard remote interface to a simulator library.
6689 So far, the library contains simulators for the Zilog Z8001/2, the
6690 Hitachi H8/300, H8/500 and Super-H.
6692 * New targets supported
6694 H8/300 simulator h8300-hitachi-hms or h8300hms
6695 H8/500 simulator h8500-hitachi-hms or h8500hms
6696 SH simulator sh-hitachi-hms or sh
6697 Z8000 simulator z8k-zilog-none or z8ksim
6698 IDT MIPS board over serial line mips-idt-ecoff
6700 Cross-debugging to GO32 targets is supported. It requires a custom
6701 version of the i386-stub.c module which is integrated with the
6702 GO32 memory extender.
6704 * New remote protocols
6706 MIPS remote debugging protocol.
6708 * New source languages supported
6710 This version includes preliminary support for Chill, a Pascal like language
6711 used by telecommunications companies. Chill support is also being integrated
6712 into the GNU compiler, but we don't know when it will be publically available.
6715 *** Changes in GDB-4.8:
6717 * HP Precision Architecture supported
6719 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6720 version of this support was available as a set of patches from the
6721 University of Utah. GDB does not support debugging of programs
6722 compiled with the HP compiler, because HP will not document their file
6723 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6724 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6726 Many problems in the preliminary version have been fixed.
6728 * Faster and better demangling
6730 We have improved template demangling and fixed numerous bugs in the GNU style
6731 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6732 character types (wchar_t) are now supported. Demangling of each symbol is now
6733 only done once, and is cached when the symbol table for a file is read in.
6734 This results in a small increase in memory usage for C programs, a moderate
6735 increase in memory usage for C++ programs, and a fantastic speedup in
6738 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6739 from the specifications in the Annotated Reference Manual, which AT&T's
6740 compiler does not actually implement.
6742 * G++ multiple inheritance compiler problem
6744 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6745 inheritance lattices was reworked to properly discover ambiguities. We
6746 recently found an example which causes this new algorithm to fail in a
6747 very subtle way, producing bad debug information for those classes.
6748 The file 'gcc.patch' (in this directory) can be applied to gcc to
6749 circumvent the problem. A future GCC release will contain a complete
6752 The previous G++ debug info problem (mentioned below for the gdb-4.7
6753 release) is fixed in gcc version 2.3.2.
6755 * Improved configure script
6757 The `configure' script will now attempt to guess your system type if
6758 you don't supply a host system type. The old scheme of supplying a
6759 host system triplet is preferable over using this. All the magic is
6760 done in the new `config.guess' script. Examine it for details.
6762 We have also brought our configure script much more in line with the FSF's
6763 version. It now supports the --with-xxx options. In particular,
6764 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6765 The resulting GDB will not be able to read arbitrary object file formats --
6766 only the format ``expected'' to be used on the configured target system.
6767 We hope to make this the default in a future release.
6769 * Documentation improvements
6771 There's new internal documentation on how to modify GDB, and how to
6772 produce clean changes to the code. We implore people to read it
6773 before submitting changes.
6775 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6776 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6777 `info' files are also provided. To build `info' files from scratch,
6778 you will need the latest `makeinfo' release, which will be available in
6779 a future texinfo-X.Y release.
6781 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6782 We're not sure exactly which versions have this problem, but it has
6783 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6784 or better. If that isn't possible, there is a patch in
6785 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6786 around this problem.
6790 GDB now supports array constants that can be used in expressions typed in by
6791 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6792 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6795 The new directory `gdb/sparclite' contains a program that demonstrates
6796 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6798 * New native hosts supported
6800 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6801 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6803 * New targets supported
6805 AMD 29k family via UDI a29k-amd-udi or udi29k
6807 * New file formats supported
6809 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6810 HPUX core files, and SCO 3.2v2 core files.
6814 Attaching to processes now works again; thanks for the many bug reports.
6816 We have also stomped on a bunch of core dumps caused by
6817 printf_filtered("%s") problems.
6819 We eliminated a copyright problem on the rpc and ptrace header files
6820 for VxWorks, which was discovered at the last minute during the 4.7
6821 release. You should now be able to build a VxWorks GDB.
6823 You can now interrupt gdb while an attached process is running. This
6824 will cause the attached process to stop, and give control back to GDB.
6826 We fixed problems caused by using too many file descriptors
6827 for reading symbols from object files and libraries. This was
6828 especially a problem for programs that used many (~100) shared
6831 The `step' command now only enters a subroutine if there is line number
6832 information for the subroutine. Otherwise it acts like the `next'
6833 command. Previously, `step' would enter subroutines if there was
6834 any debugging information about the routine. This avoids problems
6835 when using `cc -g1' on MIPS machines.
6837 * Internal improvements
6839 GDB's internal interfaces have been improved to make it easier to support
6840 debugging of multiple languages in the future.
6842 GDB now uses a common structure for symbol information internally.
6843 Minimal symbols (derived from linkage symbols in object files), partial
6844 symbols (from a quick scan of debug information), and full symbols
6845 contain a common subset of information, making it easier to write
6846 shared code that handles any of them.
6848 * New command line options
6850 We now accept --silent as an alias for --quiet.
6854 The memory-mapped-malloc library is now licensed under the GNU Library
6855 General Public License.
6857 *** Changes in GDB-4.7:
6859 * Host/native/target split
6861 GDB has had some major internal surgery to untangle the support for
6862 hosts and remote targets. Now, when you configure GDB for a remote
6863 target, it will no longer load in all of the support for debugging
6864 local programs on the host. When fully completed and tested, this will
6865 ensure that arbitrary host/target combinations are possible.
6867 The primary conceptual shift is to separate the non-portable code in
6868 GDB into three categories. Host specific code is required any time GDB
6869 is compiled on that host, regardless of the target. Target specific
6870 code relates to the peculiarities of the target, but can be compiled on
6871 any host. Native specific code is everything else: it can only be
6872 built when the host and target are the same system. Child process
6873 handling and core file support are two common `native' examples.
6875 GDB's use of /proc for controlling Unix child processes is now cleaner.
6876 It has been split out into a single module under the `target_ops' vector,
6877 plus two native-dependent functions for each system that uses /proc.
6879 * New hosts supported
6881 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6882 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6883 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6885 * New targets supported
6887 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6888 68030 and CPU32 m68030-*-*, m68332-*-*
6890 * New native hosts supported
6892 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6893 (386bsd is not well tested yet)
6894 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6896 * New file formats supported
6898 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6899 supports reading of `a.out.adobe' object files, which are an a.out
6900 format extended with minimal information about multiple sections.
6904 `show copying' is the same as the old `info copying'.
6905 `show warranty' is the same as `info warrantee'.
6906 These were renamed for consistency. The old commands continue to work.
6908 `info handle' is a new alias for `info signals'.
6910 You can now define pre-command hooks, which attach arbitrary command
6911 scripts to any command. The commands in the hook will be executed
6912 prior to the user's command. You can also create a hook which will be
6913 executed whenever the program stops. See gdb.texinfo.
6917 We now deal with Cfront style name mangling, and can even extract type
6918 info from mangled symbols. GDB can automatically figure out which
6919 symbol mangling style your C++ compiler uses.
6921 Calling of methods and virtual functions has been improved as well.
6925 The crash that occured when debugging Sun Ansi-C compiled binaries is
6926 fixed. This was due to mishandling of the extra N_SO stabs output
6929 We also finally got Ultrix 4.2 running in house, and fixed core file
6930 support, with help from a dozen people on the net.
6932 John M. Farrell discovered that the reason that single-stepping was so
6933 slow on all of the Mips based platforms (primarily SGI and DEC) was
6934 that we were trying to demangle and lookup a symbol used for internal
6935 purposes on every instruction that was being stepped through. Changing
6936 the name of that symbol so that it couldn't be mistaken for a C++
6937 mangled symbol sped things up a great deal.
6939 Rich Pixley sped up symbol lookups in general by getting much smarter
6940 about when C++ symbol mangling is necessary. This should make symbol
6941 completion (TAB on the command line) much faster. It's not as fast as
6942 we'd like, but it's significantly faster than gdb-4.6.
6946 A new user controllable variable 'call_scratch_address' can
6947 specify the location of a scratch area to be used when GDB
6948 calls a function in the target. This is necessary because the
6949 usual method of putting the scratch area on the stack does not work
6950 in systems that have separate instruction and data spaces.
6952 We integrated changes to support the 29k UDI (Universal Debugger
6953 Interface), but discovered at the last minute that we didn't have all
6954 of the appropriate copyright paperwork. We are working with AMD to
6955 resolve this, and hope to have it available soon.
6959 We have sped up the remote serial line protocol, especially for targets
6960 with lots of registers. It now supports a new `expedited status' ('T')
6961 message which can be used in place of the existing 'S' status message.
6962 This allows the remote stub to send only the registers that GDB
6963 needs to make a quick decision about single-stepping or conditional
6964 breakpoints, eliminating the need to fetch the entire register set for
6965 each instruction being stepped through.
6967 The GDB remote serial protocol now implements a write-through cache for
6968 registers, only re-reading the registers if the target has run.
6970 There is also a new remote serial stub for SPARC processors. You can
6971 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6972 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6973 processor with a serial port.
6977 Configure.in files have become much easier to read and modify. A new
6978 `table driven' format makes it more obvious what configurations are
6979 supported, and what files each one uses.
6983 There is a new opcodes library which will eventually contain all of the
6984 disassembly routines and opcode tables. At present, it only contains
6985 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6986 disassembler (binutils/objdump) to share these routines.
6988 The libiberty library is now copylefted under the GNU Library General
6989 Public License. This allows more liberal use, and was done so libg++
6990 can use it. This makes no difference to GDB, since the Library License
6991 grants all the rights from the General Public License.
6995 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6996 reference to the stabs symbol info used by the debugger. It is (as far
6997 as we know) the only published document on this fascinating topic. We
6998 encourage you to read it, compare it to the stabs information on your
6999 system, and send improvements on the document in general (to
7000 bug-gdb@prep.ai.mit.edu).
7002 And, of course, many bugs have been fixed.
7005 *** Changes in GDB-4.6:
7007 * Better support for C++ function names
7009 GDB now accepts as input the "demangled form" of C++ overloaded function
7010 names and member function names, and can do command completion on such names
7011 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7012 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7013 Make use of command completion, it is your friend.
7015 GDB also now accepts a variety of C++ mangled symbol formats. They are
7016 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7017 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7018 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7019 for the list of formats.
7021 * G++ symbol mangling problem
7023 Recent versions of gcc have a bug in how they emit debugging information for
7024 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7025 directory) can be applied to gcc to fix the problem. Alternatively, if you
7026 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7027 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7028 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7031 * New 'maintenance' command
7033 All of the commands related to hacking GDB internals have been moved out of
7034 the main command set, and now live behind the 'maintenance' command. This
7035 can also be abbreviated as 'mt'. The following changes were made:
7037 dump-me -> maintenance dump-me
7038 info all-breakpoints -> maintenance info breakpoints
7039 printmsyms -> maintenance print msyms
7040 printobjfiles -> maintenance print objfiles
7041 printpsyms -> maintenance print psymbols
7042 printsyms -> maintenance print symbols
7044 The following commands are new:
7046 maintenance demangle Call internal GDB demangler routine to
7047 demangle a C++ link name and prints the result.
7048 maintenance print type Print a type chain for a given symbol
7050 * Change to .gdbinit file processing
7052 We now read the $HOME/.gdbinit file before processing the argv arguments
7053 (e.g. reading symbol files or core files). This allows global parameters to
7054 be set, which will apply during the symbol reading. The ./.gdbinit is still
7055 read after argv processing.
7057 * New hosts supported
7059 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7061 GNU/Linux support i386-unknown-linux or linux
7063 We are also including code to support the HP/PA running BSD and HPUX. This
7064 is almost guaranteed not to work, as we didn't have time to test or build it
7065 for this release. We are including it so that the more adventurous (or
7066 masochistic) of you can play with it. We also had major problems with the
7067 fact that the compiler that we got from HP doesn't support the -g option.
7070 * New targets supported
7072 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7074 * More smarts about finding #include files
7076 GDB now remembers the compilation directory for all include files, and for
7077 all files from which C is generated (like yacc and lex sources). This
7078 greatly improves GDB's ability to find yacc/lex sources, and include files,
7079 especially if you are debugging your program from a directory different from
7080 the one that contains your sources.
7082 We also fixed a bug which caused difficulty with listing and setting
7083 breakpoints in include files which contain C code. (In the past, you had to
7084 try twice in order to list an include file that you hadn't looked at before.)
7086 * Interesting infernals change
7088 GDB now deals with arbitrary numbers of sections, where the symbols for each
7089 section must be relocated relative to that section's landing place in the
7090 target's address space. This work was needed to support ELF with embedded
7091 stabs used by Solaris-2.0.
7093 * Bug fixes (of course!)
7095 There have been loads of fixes for the following things:
7096 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7097 i960, stabs, DOS(GO32), procfs, etc...
7099 See the ChangeLog for details.
7101 *** Changes in GDB-4.5:
7103 * New machines supported (host and target)
7105 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7107 SGI Irix-4.x mips-sgi-irix4 or iris4
7109 * New malloc package
7111 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7112 Mmalloc is capable of handling mutiple heaps of memory. It is also
7113 capable of saving a heap to a file, and then mapping it back in later.
7114 This can be used to greatly speedup the startup of GDB by using a
7115 pre-parsed symbol table which lives in a mmalloc managed heap. For
7116 more details, please read mmalloc/mmalloc.texi.
7120 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7121 'help info proc' for details.
7123 * MIPS ecoff symbol table format
7125 The code that reads MIPS symbol table format is now supported on all hosts.
7126 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7129 * File name changes for MS-DOS
7131 Many files in the config directories have been renamed to make it easier to
7132 support GDB on MS-DOSe systems (which have very restrictive file name
7133 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7134 environment) is close to working but has some remaining problems. Note
7135 that debugging of DOS programs is not supported, due to limitations
7136 in the ``operating system'', but it can be used to host cross-debugging.
7138 * Cross byte order fixes
7140 Many fixes have been made to support cross debugging of Sparc and MIPS
7141 targets from hosts whose byte order differs.
7143 * New -mapped and -readnow options
7145 If memory-mapped files are available on your system through the 'mmap'
7146 system call, you can use the -mapped option on the `file' or
7147 `symbol-file' commands to cause GDB to write the symbols from your
7148 program into a reusable file. If the program you are debugging is
7149 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7150 Future GDB debugging sessions will notice the presence of this file,
7151 and will quickly map in symbol information from it, rather than reading
7152 the symbol table from the executable program. Using the '-mapped'
7153 option in a GDB `file' or `symbol-file' command has the same effect as
7154 starting GDB with the '-mapped' command-line option.
7156 You can cause GDB to read the entire symbol table immediately by using
7157 the '-readnow' option with any of the commands that load symbol table
7158 information (or on the GDB command line). This makes the command
7159 slower, but makes future operations faster.
7161 The -mapped and -readnow options are typically combined in order to
7162 build a `fred.syms' file that contains complete symbol information.
7163 A simple GDB invocation to do nothing but build a `.syms' file for future
7166 gdb -batch -nx -mapped -readnow programname
7168 The `.syms' file is specific to the host machine on which GDB is run.
7169 It holds an exact image of GDB's internal symbol table. It cannot be
7170 shared across multiple host platforms.
7172 * longjmp() handling
7174 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7175 siglongjmp() without losing control. This feature has not yet been ported to
7176 all systems. It currently works on many 386 platforms, all MIPS-based
7177 platforms (SGI, DECstation, etc), and Sun3/4.
7181 Preliminary work has been put in to support the new Solaris OS from Sun. At
7182 this time, it can control and debug processes, but it is not capable of
7187 As always, many many bug fixes. The major areas were with g++, and mipsread.
7188 People using the MIPS-based platforms should experience fewer mysterious
7189 crashes and trashed symbol tables.
7191 *** Changes in GDB-4.4:
7193 * New machines supported (host and target)
7195 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7197 BSD Reno on Vax vax-dec-bsd
7198 Ultrix on Vax vax-dec-ultrix
7200 * New machines supported (target)
7202 AMD 29000 embedded, using EBMON a29k-none-none
7206 GDB continues to improve its handling of C++. `References' work better.
7207 The demangler has also been improved, and now deals with symbols mangled as
7208 per the Annotated C++ Reference Guide.
7210 GDB also now handles `stabs' symbol information embedded in MIPS
7211 `ecoff' symbol tables. Since the ecoff format was not easily
7212 extensible to handle new languages such as C++, this appeared to be a
7213 good way to put C++ debugging info into MIPS binaries. This option
7214 will be supported in the GNU C compiler, version 2, when it is
7217 * New features for SVR4
7219 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7220 shared libraries. Debugging dynamically linked programs should present
7221 only minor differences from debugging statically linked programs.
7223 The `info proc' command will print out information about any process
7224 on an SVR4 system (including the one you are debugging). At the moment,
7225 it prints the address mappings of the process.
7227 If you bring up GDB on another SVR4 system, please send mail to
7228 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7230 * Better dynamic linking support in SunOS
7232 Reading symbols from shared libraries which contain debugging symbols
7233 now works properly. However, there remain issues such as automatic
7234 skipping of `transfer vector' code during function calls, which
7235 make it harder to debug code in a shared library, than to debug the
7236 same code linked statically.
7240 GDB is now using the latest `getopt' routines from the FSF. This
7241 version accepts the -- prefix for options with long names. GDB will
7242 continue to accept the old forms (-option and +option) as well.
7243 Various single letter abbreviations for options have been explicity
7244 added to the option table so that they won't get overshadowed in the
7245 future by other options that begin with the same letter.
7249 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7250 Many assorted bugs have been handled. Many more remain to be handled.
7251 See the various ChangeLog files (primarily in gdb and bfd) for details.
7254 *** Changes in GDB-4.3:
7256 * New machines supported (host and target)
7258 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7259 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7260 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7262 * Almost SCO Unix support
7264 We had hoped to support:
7265 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7266 (except for core file support), but we discovered very late in the release
7267 that it has problems with process groups that render gdb unusable. Sorry
7268 about that. I encourage people to fix it and post the fixes.
7270 * Preliminary ELF and DWARF support
7272 GDB can read ELF object files on System V Release 4, and can handle
7273 debugging records for C, in DWARF format, in ELF files. This support
7274 is preliminary. If you bring up GDB on another SVR4 system, please
7275 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7280 GDB now uses the latest `readline' library. One user-visible change
7281 is that two tabs will list possible command completions, which previously
7282 required typing M-? (meta-question mark, or ESC ?).
7286 The `stepi' bug that many of you noticed has been squashed.
7287 Many bugs in C++ have been handled. Many more remain to be handled.
7288 See the various ChangeLog files (primarily in gdb and bfd) for details.
7290 * State of the MIPS world (in case you wondered):
7292 GDB can understand the symbol tables emitted by the compilers
7293 supplied by most vendors of MIPS-based machines, including DEC. These
7294 symbol tables are in a format that essentially nobody else uses.
7296 Some versions of gcc come with an assembler post-processor called
7297 mips-tfile. This program is required if you want to do source-level
7298 debugging of gcc-compiled programs. I believe FSF does not ship
7299 mips-tfile with gcc version 1, but it will eventually come with gcc
7302 Debugging of g++ output remains a problem. g++ version 1.xx does not
7303 really support it at all. (If you're lucky, you should be able to get
7304 line numbers and stack traces to work, but no parameters or local
7305 variables.) With some work it should be possible to improve the
7308 When gcc version 2 is released, you will have somewhat better luck.
7309 However, even then you will get confusing results for inheritance and
7312 We will eventually provide full debugging of g++ output on
7313 DECstations. This will probably involve some kind of stabs-in-ecoff
7314 encapulation, but the details have not been worked out yet.
7317 *** Changes in GDB-4.2:
7319 * Improved configuration
7321 Only one copy of `configure' exists now, and it is not self-modifying.
7322 Porting BFD is simpler.
7326 The `step' and `next' commands now only stop at the first instruction
7327 of a source line. This prevents the multiple stops that used to occur
7328 in switch statements, for-loops, etc. `Step' continues to stop if a
7329 function that has debugging information is called within the line.
7333 Lots of small bugs fixed. More remain.
7335 * New host supported (not target)
7337 Intel 386 PC clone running Mach i386-none-mach
7340 *** Changes in GDB-4.1:
7342 * Multiple source language support
7344 GDB now has internal scaffolding to handle several source languages.
7345 It determines the type of each source file from its filename extension,
7346 and will switch expression parsing and number formatting to match the
7347 language of the function in the currently selected stack frame.
7348 You can also specifically set the language to be used, with
7349 `set language c' or `set language modula-2'.
7353 GDB now has preliminary support for the GNU Modula-2 compiler,
7354 currently under development at the State University of New York at
7355 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7356 continue through the fall of 1991 and into 1992.
7358 Other Modula-2 compilers are currently not supported, and attempting to
7359 debug programs compiled with them will likely result in an error as the
7360 symbol table is read. Feel free to work on it, though!
7362 There are hooks in GDB for strict type checking and range checking,
7363 in the `Modula-2 philosophy', but they do not currently work.
7367 GDB can now write to executable and core files (e.g. patch
7368 a variable's value). You must turn this switch on, specify
7369 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7370 by assigning a new value to a variable. Modifications take
7373 * Automatic SunOS shared library reading
7375 When you run your program, GDB automatically determines where its
7376 shared libraries (if any) have been loaded, and reads their symbols.
7377 The `share' command is no longer needed. This also works when
7378 examining core files.
7382 You can specify the number of lines that the `list' command shows.
7385 * New machines supported (host and target)
7387 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7388 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7389 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7391 * New hosts supported (not targets)
7393 IBM RT/PC: romp-ibm-aix or rtpc
7395 * New targets supported (not hosts)
7397 AMD 29000 embedded with COFF a29k-none-coff
7398 AMD 29000 embedded with a.out a29k-none-aout
7399 Ultracomputer remote kernel debug a29k-nyu-kern
7401 * New remote interfaces
7407 *** Changes in GDB-4.0:
7411 Wide output is wrapped at good places to make the output more readable.
7413 Gdb now supports cross-debugging from a host machine of one type to a
7414 target machine of another type. Communication with the target system
7415 is over serial lines. The ``target'' command handles connecting to the
7416 remote system; the ``load'' command will download a program into the
7417 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7418 also supports debugging of realtime processes running under VxWorks,
7419 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7420 stub on the target system.
7422 New CPUs supported include the AMD 29000 and Intel 960.
7424 GDB now reads object files and symbol tables via a ``binary file''
7425 library, which allows a single copy of GDB to debug programs of multiple
7426 object file types such as a.out and coff.
7428 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7429 refcard.dvi and refcard.ps are available to format it).
7432 * Control-Variable user interface simplified
7434 All variables that control the operation of the debugger can be set
7435 by the ``set'' command, and displayed by the ``show'' command.
7437 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7438 ``Show prompt'' produces the response:
7439 Gdb's prompt is new-gdb=>.
7441 What follows are the NEW set commands. The command ``help set'' will
7442 print a complete list of old and new set commands. ``help set FOO''
7443 will give a longer description of the variable FOO. ``show'' will show
7444 all of the variable descriptions and their current settings.
7446 confirm on/off: Enables warning questions for operations that are
7447 hard to recover from, e.g. rerunning the program while
7448 it is already running. Default is ON.
7450 editing on/off: Enables EMACS style command line editing
7451 of input. Previous lines can be recalled with
7452 control-P, the current line can be edited with control-B,
7453 you can search for commands with control-R, etc.
7456 history filename NAME: NAME is where the gdb command history
7457 will be stored. The default is .gdb_history,
7458 or the value of the environment variable
7461 history size N: The size, in commands, of the command history. The
7462 default is 256, or the value of the environment variable
7465 history save on/off: If this value is set to ON, the history file will
7466 be saved after exiting gdb. If set to OFF, the
7467 file will not be saved. The default is OFF.
7469 history expansion on/off: If this value is set to ON, then csh-like
7470 history expansion will be performed on
7471 command line input. The default is OFF.
7473 radix N: Sets the default radix for input and output. It can be set
7474 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7475 in the current radix, so "set radix 10" is always a no-op.
7477 height N: This integer value is the number of lines on a page. Default
7478 is 24, the current `stty rows'' setting, or the ``li#''
7479 setting from the termcap entry matching the environment
7482 width N: This integer value is the number of characters on a line.
7483 Default is 80, the current `stty cols'' setting, or the ``co#''
7484 setting from the termcap entry matching the environment
7487 Note: ``set screensize'' is obsolete. Use ``set height'' and
7488 ``set width'' instead.
7490 print address on/off: Print memory addresses in various command displays,
7491 such as stack traces and structure values. Gdb looks
7492 more ``symbolic'' if you turn this off; it looks more
7493 ``machine level'' with it on. Default is ON.
7495 print array on/off: Prettyprint arrays. New convenient format! Default
7498 print demangle on/off: Print C++ symbols in "source" form if on,
7501 print asm-demangle on/off: Same, for assembler level printouts
7504 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7507 * Support for Epoch Environment.
7509 The epoch environment is a version of Emacs v18 with windowing. One
7510 new command, ``inspect'', is identical to ``print'', except that if you
7511 are running in the epoch environment, the value is printed in its own
7515 * Support for Shared Libraries
7517 GDB can now debug programs and core files that use SunOS shared libraries.
7518 Symbols from a shared library cannot be referenced
7519 before the shared library has been linked with the program (this
7520 happens after you type ``run'' and before the function main() is entered).
7521 At any time after this linking (including when examining core files
7522 from dynamically linked programs), gdb reads the symbols from each
7523 shared library when you type the ``sharedlibrary'' command.
7524 It can be abbreviated ``share''.
7526 sharedlibrary REGEXP: Load shared object library symbols for files
7527 matching a unix regular expression. No argument
7528 indicates to load symbols for all shared libraries.
7530 info sharedlibrary: Status of loaded shared libraries.
7535 A watchpoint stops execution of a program whenever the value of an
7536 expression changes. Checking for this slows down execution
7537 tremendously whenever you are in the scope of the expression, but is
7538 quite useful for catching tough ``bit-spreader'' or pointer misuse
7539 problems. Some machines such as the 386 have hardware for doing this
7540 more quickly, and future versions of gdb will use this hardware.
7542 watch EXP: Set a watchpoint (breakpoint) for an expression.
7544 info watchpoints: Information about your watchpoints.
7546 delete N: Deletes watchpoint number N (same as breakpoints).
7547 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7548 enable N: Re-enables watchpoint number N (same as breakpoints).
7551 * C++ multiple inheritance
7553 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7556 * C++ exception handling
7558 Gdb now supports limited C++ exception handling. Besides the existing
7559 ability to breakpoint on an exception handler, gdb can breakpoint on
7560 the raising of an exception (before the stack is peeled back to the
7563 catch FOO: If there is a FOO exception handler in the dynamic scope,
7564 set a breakpoint to catch exceptions which may be raised there.
7565 Multiple exceptions (``catch foo bar baz'') may be caught.
7567 info catch: Lists all exceptions which may be caught in the
7568 current stack frame.
7571 * Minor command changes
7573 The command ``call func (arg, arg, ...)'' now acts like the print
7574 command, except it does not print or save a value if the function's result
7575 is void. This is similar to dbx usage.
7577 The ``up'' and ``down'' commands now always print the frame they end up
7578 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7579 frames without printing.
7581 * New directory command
7583 'dir' now adds directories to the FRONT of the source search path.
7584 The path starts off empty. Source files that contain debug information
7585 about the directory in which they were compiled can be found even
7586 with an empty path; Sun CC and GCC include this information. If GDB can't
7587 find your source file in the current directory, type "dir .".
7589 * Configuring GDB for compilation
7591 For normal use, type ``./configure host''. See README or gdb.texinfo
7594 GDB now handles cross debugging. If you are remotely debugging between
7595 two different machines, type ``./configure host -target=targ''.
7596 Host is the machine where GDB will run; targ is the machine
7597 where the program that you are debugging will run.